To see the other types of publications on this topic, follow the link: Multi-objective Contiguous-Cells Transportation Model.
Journal articles on the topic 'Multi-objective Contiguous-Cells Transportation Model'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Multi-objective Contiguous-Cells Transportation Model.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Adewole, Mark Adegbola, David Adeyeye Ademola, Ekepre Charles-Owaba Oliver, and Sarah Okunade Oladunni. "Contiguous-cells transportation model for multi-objective non-pre-emptive production and maintenance scheduling." Global Journal of Engineering and Technology Advances 5, no. 3 (2020): 036–49. https://doi.org/10.5281/zenodo.4478434.
Full textAbstract:
The long-standing issue of non-pre-emption in ‘multi-period’ production/maintenance (P/M) scheduling has always been a challenge and this has been the focus of many researchers. Recently, the Contiguous-Cells Transportation Model (CCTM) was proposed to address this problem. However, the CCTM is limited to non-pre-emptive P/M scheduling decision situations where only one objective is of concern. The multiple objective non-pre-emptive P/M scheduling are encountered more frequently in the real world than the single objective case. This study proposed the Multi-Objective Contiguous-Cells Transportation Model (MOCCTM) and the solution procedure for handling multi-objective cases of non-pre-emptive production/maintenance scheduling. The variables and parameters of the CCTM were adopted with modifications to cater for the multi-objective requirements. A composite multiple-objective function was formulated by employing multi-objective optimisation techniques of assigning weights to objectives and normalisation of objectives. An algorithm similar to the conventional least cost method was developed for the solution of the MOCCTM. A bi-objective non-pre-emptive maintenance scheduling problem of 5 production machines across an operation and maintenance planning horizon of 10 periods was used to demonstrate the application of the MOCCTM. The MOCCTM is a good approach to solving multi-objective P/M scheduling problems in a non-pre-emptive environment.
2
Adewole Mark Adegbola, Ademola David Adeyeye, Oliver Ekepre Charles-Owaba, and Oladunni Sarah Okunade. "Contiguous-cells transportation model for multi-objective non-pre-emptive production and maintenance scheduling." Global Journal of Engineering and Technology Advances 5, no. 3 (2020): 036–49. http://dx.doi.org/10.30574/gjeta.2020.5.3.0059.
Full textAbstract:
The long-standing issue of non-pre-emption in ‘multi-period’ production/maintenance (P/M) scheduling has always been a challenge and this has been the focus of many researchers. Recently, the Contiguous-Cells Transportation Model (CCTM) was proposed to address this problem. However, the CCTM is limited to non-pre-emptive P/M scheduling decision situations where only one objective is of concern. The multiple objective non-pre-emptive P/M scheduling are encountered more frequently in the real world than the single objective case. This study proposed the Multi-Objective Contiguous-Cells Transportation Model (MOCCTM) and the solution procedure for handling multi-objective cases of non-pre-emptive production/maintenance scheduling. The variables and parameters of the CCTM were adopted with modifications to cater for the multi-objective requirements. A composite multiple-objective function was formulated by employing multi-objective optimisation techniques of assigning weights to objectives and normalisation of objectives. An algorithm similar to the conventional least cost method was developed for the solution of the MOCCTM. A bi-objective non-pre-emptive maintenance scheduling problem of 5 production machines across an operation and maintenance planning horizon of 10 periods was used to demonstrate the application of the MOCCTM. The MOCCTM is a good approach to solving multi-objective P/M scheduling problems in a non-pre-emptive environment.
3
Charles-Owaba, O. E., V. Oladokun, and O. Okunade. "Development of the Contiguous-cells Transportation Problem." Engineering, Technology & Applied Science Research 5, no. 4 (2015): 825–31. https://doi.org/10.5281/zenodo.28397.
Full textAbstract:
The issue of scheduling a long string of multi-period activities which have to be completed without interruption has always been an industrial challenge. The existing production/maintenance scheduling algorithms can only handle situations where activities can be split into two or more sets of activities carried out in non-contiguous sets of work periods. This study proposes a contiguous-periods production/maintenance scheduling approach using the Transportation Model. Relevant variables and parameters of contiguous-cells scheduling problem were taken from the literature. A scheduling optimization problem was defined and solved using a contiguous-cells transportation algorithm (CCTA) which was applied in order to determine the optimal maintenance schedule of a fleet of ships at a dockyard in South-Western Nigeria. Fifteen different problems were solved. It is concluded that the contiguous-cells transportation approach to production/ maintenance scheduling is feasible. The model will be a useful decision support tool for scheduling maintenance operations.
4
Charles-Owaba, O. E., V. Oladokun, and O. Okunade. "Development of the Contiguous-cells Transportation Problem." Engineering, Technology & Applied Science Research 5, no. 4 (2015): 825–31. http://dx.doi.org/10.48084/etasr.546.
Full textAbstract:
The issue of scheduling a long string of multi-period activities which have to be completed without interruption has always been an industrial challenge. The existing production/maintenance scheduling algorithms can only handle situations where activities can be split into two or more sets of activities carried out in non-contiguous sets of work periods. This study proposes a contiguous-periods production/maintenance scheduling approach using the Transportation Model. Relevant variables and parameters of contiguous-cells scheduling problem were taken from the literature. A scheduling optimization problem was defined and solved using a contiguous-cells transportation algorithm (CCTA) which was applied in order to determine the optimal maintenance schedule of a fleet of ships at a dockyard in South-Western Nigeria. Fifteen different problems were solved. It is concluded that the contiguous-cells transportation approach to production/ maintenance scheduling is feasible. The model will be a useful decision support tool for scheduling maintenance operations.
5
Kayani, Saheeb Ahmed, Salman Sagheer Warsi, and Raja Awais Liaqait. "A Smart Decision Support Framework for Sustainable and Resilient Supplier Selection and Order Allocation in the Pharmaceutical Industry." Sustainability 15, no. 7 (2023): 5962. http://dx.doi.org/10.3390/su15075962.
Full textAbstract:
Supplier selection and order allocation (SS-OA) are two of the most important strategic decisions for supply chain network design and operation. If sustainability and resilience criteria are taken into consideration together and a holistic sustainable and resilient SS-OA is carried out, it may enable the supply chain network to perform better when subjected to disruption scenarios. In this research paper, a novel comprehensive multi-phase, multi-period sustainable, and resilient SS-OA decision support framework has been proposed. This framework integrates fuzzy multi-criteria decision-making (MCDM) techniques with a fuzzy multi-objective mixed integer nonlinear programming (MOMINLP) mathematical model to optimize triple bottom line (TBL) sustainability and resilience criteria simultaneously for a multi-modal, multi-echelon supply chain network. The proposed framework has been implemented using real-time data collected from the pharmaceutical industry. The results show that among the TBL sustainability criteria, product price, past business, innovative capability, and information disclosure rank as the most significant sub-criteria for the DMs in the pharmaceutical industry, while robustness and flexibility are considered the most valued attributes for potential suppliers as far as the resilience criterion is concerned. An assessment of the results has revealed that transfer cost and custom clearance cost together comprise more than two-thirds of the overall cost of the supply chain network. It has also been noted that inland transportation of goods is dominated by rail as the most preferred mode of transport. Transportation by rail is particularly preferred by suppliers located in geographically contiguous countries.
6
Song, Xiao Na, Shu Ai Sun, and Hai Chao Liu. "Research on Network Manufacturing Resources Optimization Deployment." Advanced Materials Research 542-543 (June 2012): 485–94. http://dx.doi.org/10.4028/www.scientific.net/amr.542-543.485.
Full textAbstract:
Networked manufacturing environment, making the task decomposition and exist out of line manufacturing cell optimization problem, propose a pre-matching rules and genetic algorithm combined with the resources optimal deployment method. In the process the task decomposition process layer by layer from the pre-match rules for task decomposition process and manufacturing units to form the pre-matching set of manufacturing unit, and when complete the task decomposition process generates the appropriate set of pre-matching manufacturing unit and then use genetic algorithm solution to processing costs, transportation costs, processing time and transportation time to build a multi-objective optimization model; to simplify the calculation, the multi-objective problem by the weight method into a single objective problem; calculated from the manufacturing unit eventually chooses the optimal set of manufacturing cells combination, making the process task global optimum processing route. Finally, exemplify the feasibility of the method.
7
Liu, Qingming, Zhengkun Zhou, Jingyan Chen, Dan Zheng, and Hongbo Zou. "Optimization Operation Strategy for Comprehensive Energy System Considering Multi-Mode Hydrogen Transportation." Processes 12, no. 12 (2024): 2893. https://doi.org/10.3390/pr12122893.
Full textAbstract:
The transformation from a fossil fuel economy to a low-carbon economy has reshaped the way energy is transmitted. As most renewable energy is obtained in the form of electricity, using green electricity to produce hydrogen is considered a promising energy carrier. However, most studies have not considered the transportation mode of hydrogen. In order to encourage the utilization of renewable energy and hydrogen, this paper proposes a comprehensive energy system optimization operation strategy considering multi-mode hydrogen transport. Firstly, to address the shortcomings in the optimization operation of existing systems regarding hydrogen transport, modeling is conducted for multi-mode hydrogen transportation through hydrogen tube trailers and pipelines. This model reflects the impact of multi-mode hydrogen delivery channels on hydrogen utilization, which helps promote the consumption of new energy in electrolysis cells to meet application demands. Based on this, the constraints of electrolyzers, combined heat and power units, hydrogen fuel cells, and energy storage systems in integrated energy systems (IESs) are further considered. With the objective of minimizing the daily operational cost of the comprehensive energy system, an optimization model for the operation considering multi-mode hydrogen transport is constructed. Lastly, based on simulation examples, the impact of multi-mode hydrogen transportation on the operational cost of the system is analyzed in detail. The results indicate that the proposed optimization strategy can reduce the operational cost of the comprehensive energy system. Hydrogen tube trailers and pipelines will have a significant impact on operational costs. Properly allocating the quantity of hydrogen tube trailers and pipelines is beneficial for reducing the operational costs of the system. Reasonable arrangement of hydrogen transportation channels is conducive to further promoting the green and economic operation of the system.
8
Mansor, Nur Sabrina, Rozieana Khairuddin, Zaitul Marlizawati Zainuddin Zainuddin, and Nozieana Khairuddin. "A Review on School Network Problem with Zone Dependent Fixed Cost and Inventory Cost." Pena Journal of Computer Science and Informatics 1, no. 1 (2025): 32–40. https://doi.org/10.37934/pjcsi.1.1.3240.
Full textAbstract:
When it comes to avoiding or contributing to a students’ decision to go to school, school distance can play a significant role. Long commutes to and from school can raise the opportunity costs of education and provide safety and security risks, particularly for female students. When compared to other types of location issues (e.g., facility location problem, location, and allocation problem), the school location model is one of the most important research efforts in the location analysis area. The location-allocation problem (LAP) has received a lot of attention in the facility location sector. The Weber issue is well-known for the LAP in continual plane. This article evaluated the problem by taking capacity limits and fixed costs into account, as every centre has a separate setup cost along with a capacity limit to service consumers. Previous research looked at lucrative places by splitting continuous space into a definite number of equal cells and then selecting the best site from a smaller range of potential spots. Inevitably, it can contribute to avoiding suitable places because unproductive regions are still considered when establishing facilities. As a result, transportation expenses might be significantly increased. In addition, alternative school network redesign methods and mathematical programming models do consider school consolidation, deletion, and addition. To optimize cost, the model should consider the development, closure, and amalgamation of a new school. The objective of this research is to develop a multi-start simulated annealing approach specifically tailored for the school network problem with zone-dependent fixed costs and inventory costs. In addition to addressing the allocation problem, this research also incorporates the consideration of zone-dependent fixed costs and inventory costs. Furthermore, inventory costs, incurred when schools are kept in specific zones, are accounted for to provide a comprehensive optimization solution. By developing a multi-start simulated annealing approach for the school network problem with zone-dependent fixed costs and inventory costs, this research aims to provide school administrators and policymakers with a valuable decision-making tool. The research also considered in the model to regulate the number of pupils that must be present in a school, allowing the model to mirror the real scenario more precisely. Finally, this research will be able to identify the best techniques for school network redesign issues.
9
Öztürk, Bahadır, and Tuğba Saraç. "Optimizing logistics warehouse space utilization with minimum total transportation." Journal of Scientific Reports-A, no. 060 (March 25, 2025): 63–78. https://doi.org/10.59313/jsr-a.1447147.
Full textAbstract:
Logistics warehouses are integral to supply chain management, enabling the efficient storage and movement of goods. However, the dynamic operational nature of these facilities, characterized by high product turnover, often results in suboptimal space utilization. This study addresses the inefficiency caused by partially filled pallets and the honeycombing effect, which leads to substantial storage capacity loss. Focusing on a third-party logistics warehouse managing apparel boxes, the uniqueness of each box introduces specific challenges in space optimization. To mitigate these issues, two integer linear programming models were developed. The first model is utilized for emptying and reallocating products from the predetermined low-capacity shelf cells to new locations. The second model simultaneously identifies both the shelf cells to be vacated and the optimal relocation destinations. Both models aim to minimize the total transportation costs. The first model is suited for rapid reallocation and efficient short-term solutions, whereas the second model offers a more holistic approach to long-term space optimization. These models provide a systematic, data-driven solution for enhancing warehouse space management. The problem is also considered bi-objective, with the objectives of maximizing the number of empty shelf cells and minimizing the total transportation costs. The bi-objective mathematical model was scalarized using the epsilon-constraint method and solved for different epsilon values. This process yielded 39 Pareto-optimal solutions. The results indicate that as more cells are emptied, both the total cost and cost per cell increase. Considering the problem in a bi-objective form has also been advantageous for offering the decision-maker not just one solution but a solution set with different numbers of cells to be emptied and different transportation costs.
10
Mazrouei Sebdani, Mohsen, Heather Baroody, and Erik Kjeang. "In-Situ Fatigue Lifetime Modeling of a Reinforced Membrane by Projecting Critical Accumulated Plastic Dissipation Energy from Pressure Differential-Accelerated Mechanical Stress Tests." ECS Meeting Abstracts MA2023-02, no. 39 (2023): 1922. http://dx.doi.org/10.1149/ma2023-02391922mtgabs.
Full textAbstract:
Polymer electrolyte fuel cells (PEFCs) have become increasingly appealing over internal combustion engines because of their high efficiency, low operating temperature, and zero CO2 emissions. Nevertheless, the transportation sector necessitates high durability and reliability, which may be difficult to predict for emerging technologies. A crucial aspect is the ability of the thin membranes that conduct ions in PEFCs to endure the chemical and mechanical stresses that arise during dynamic operations. For mechanical fatigue, temperature and relative humidity (RH) fluctuations induce dynamic stresses that lead to the formation and propagation of microcracks in the membrane. As the membrane is confined by other components in the membrane-electrode assembly (MEA), changes in temperature and humidity can generate thermal and swelling strains in the membrane, leading to dynamic and residual stresses [1]. The US Department of Energy sets a passing criterion of 20,000 RH cycles for mechanical fatigue assessment. However, many modern reinforced membranes have already passed this threshold without failing [2]. Therefore, Ref [3] introduced a pressure differential between the cathode and anode sides of the membrane at 80°C to speed up the testing. In this research, the pressure differential-accelerated mechanical stress test (ΔP-AMST) method was applied to a reinforced membrane at two different temperatures and with four times faster humidity cycles in a wider range of ΔPs. This objective is to project the mechanical fatigue lifetime from the ΔP-AMST to the membrane under its in-situ conditions by using the critical accumulated plastic dissipation energy (CAPDE) in ΔP-AMSTs and the plastic dissipation energy (PDE) during a single cycle of humidity that the membrane experiences under complete fuel cell settings. The first step involves performing a series of ∆P-AMST, and in the second step, a finite element model (FEM) for ∆P-AMST based on the developed constitutive model for the tensile tests that covers temperature, humidity, and swelling strain impacts is built, and therefore its S-N curve is extracted. Next, a FEM model for a complete fuel cell is created, and the mechanical fatigue life is estimated by dividing the CAPDE in ∆P-AMST by the PDE in one cycle of the in-situ modeled membrane by considering amplitude stress as a link between the full fuel cell model and ∆P-AMST, as illustrated in Figure 1 and verified by previous studies [4,5]. In the final step, we will also discuss opportunities to integrate the present mechanical fatigue model with a chemical degradation module to simulate its impacts on fatigue lifetime. This integration includes the two main effects of chemical degradation, which are reflected in the thickness of the reinforced membrane [6] and its updated CAPDE [7]. Acknowledgments The authors gratefully acknowledge AVL Fuel Cell Canada and Mitacs for supporting this project. The authors also thank Roger Penn and Amy Nelson for technical advice. References [1] Alavijeh AS, Bhattacharya S, Thomas O, Chuy C, Yang Y, Zhang H, et al. Effect of hygral swelling and shrinkage on mechanical durability of fuel cell membranes. J Power Sources 2019;427:207–14. [2] Rodgers MP, Bonville LJ, Mukundan R, Borup RL, Ahluwalia R, Beattie P, et al. Perfluorinated sulfonic acid membrane and membrane electrode assembly degradation correlating accelerated stress testing and lifetime testing. ECS Trans 2013;58:129. [3] Alavijeh AS, Bhattacharya S, Thomas O, Chuy C, Kjeang E. A rapid mechanical durability test for reinforced fuel cell membranes. J Power Sources Adv 2020;2:100010. [4] Chen J, Goshtasbi A, Soleymani AP, Ricketts M, Waldecker J, Xu C, et al. Effects of cycle duration and test hardware in relative humidity cycling of a polymer electrolyte membrane. J Power Sources 2020;476:228576. [5] Hasan M, Chen J, Waldecker JR, Santare MH. Predicting fatigue lifetimes of a reinforced membrane in polymer electrolyte membrane fuel cell using plastic energy. J Power Sources 2022;539:231597. [6] Liu H, Chen J, Hissel D, Hou M, Shao Z. A multi-scale hybrid degradation index for proton exchange membrane fuel cells. J Power Sources 2019;437:226916. [7] Sun X, Shi S, Fu Y, Chen J, Lin Q, Hu J, et al. Embrittlement induced fracture behavior and mechanisms of perfluorosulfonic-acid membranes after chemical degradation. J Power Sources 2020;453:227893. Figure 1
11
Hossain, Tasmin, Daniela S. Jones, Edward Godfrey, Daniel Saloni, Mahmoud Sharara, and Damon S. Hartley. "Nth-plant scenario for blended pellets of Miscanthus, Switchgrass, and Corn Stover using multi-modal transportation: Biorefineries and depots in the contiguous U.S." Biomass and Bioenergy 183 (April 2024): 107162. http://dx.doi.org/10.1016/j.biombioe.2024.107162.
Full text
12
Shan, Zhenyu, Fei Yang, Xingzi Shi, and Yaping Cui. "Hybrid Learning Model of Global–Local Graph Attention Network and XGBoost for Inferring Origin–Destination Flows." ISPRS International Journal of Geo-Information 14, no. 5 (2025): 182. https://doi.org/10.3390/ijgi14050182.
Full textAbstract:
Origin–destination (OD) flows are essential for urban studies, yet their acquisition is often hampered by high costs and privacy constraints. Prevailing inference methodologies inadequately address latent spatial dependencies between non-contiguous and distant areas, which are useful for understanding modern transportation systems with expanding regional interactions. To address these challenges, this paper propose a hybrid learning model with the Global–Local Graph Attention Network and XGBoost (GLGAT-XG) to infer OD flows from both global and local geographic contextual information. First, we represent the study area as an undirected weighted graph. Second, we design the GLGAT to encode spatial correlation and urban feature information into the embeddings within a multitask setup. Specifically, the GLGAT employs a graph transformer to capture global spatial correlations and a graph attention network to extract local spatial correlations followed by weighted fusion to ensure validity. Finally, OD flow inference is performed by XGBoost based on the GLGAT-generated embeddings. The experimental results of multiple real-world datasets demonstrate an 8% improvement in RMSE, 7% in MAE, and 10% in CPC over baselines. Additionally, we produce a multi-scale OD dataset in Xian, China, to further reveal spatial-scale effects. This research builds on existing OD flow inference methodologies and offers significant practical implications for urban planning and sustainable development.
13
Li, Hong-Yi, Zeli Tan, Hongbo Ma, et al. "A new large-scale suspended sediment model and its application over the United States." Hydrology and Earth System Sciences 26, no. 3 (2022): 665–88. http://dx.doi.org/10.5194/hess-26-665-2022.
Full textAbstract:
Abstract. Suspended sediment plays a vital role in the regional and global cycling of carbon and nutrients by carrying carbon and nutrients from headwaters into lowland rivers and the oceans. Sediment transport through river systems is often fundamentally modified by human activities such as reservoir management. However, a physically based representation of sediment transport is still missing in most existing Earth system models (ESMs), which are essential tools for modeling and predicting Earth system changes. Here, we introduce a multi-process river sediment module for ESMs, which includes (1) hillslope soil erosion and sediment discharge into streams, (2) sediment transport processes through river networks, (3) reservoir operation based on the inflows from upstream areas and water demand from downstream areas, and (4) sediment trapping by reservoirs. All model parameters are estimated a priori without calibration. We apply this new sediment modeling framework to the contiguous United States and validate it against historical observations of monthly streamflow and sediment discharges at 35 river gauges. The model reasonably well captures the long-term balance and seasonal variations of suspended sediment in large river systems. Furthermore, our model results show that suspended sediment discharge in managed rivers is affected more by reservoirs' direct trapping of sediment particles than by their flow regulation. This new sediment module enables future modeling of the transportation and transformation of carbon and nutrients carried by the fine sediment along the river–ocean continuum to close the global carbon and nutrient cycles.
14
Li, Jian-Guo. "An efficient multi-resolution grid for global models and coupled systems." Advances in Science and Research 16 (July 8, 2019): 137–42. http://dx.doi.org/10.5194/asr-16-137-2019.
Full textAbstract:
Abstract. The latitude-longitude (lat-lon) grid is the most widely used global coordinate system for various purposes but its singularity at the Pole and the vector polar problems associated with its converging meridians hinder its applications. Well from the very start of numerical modelling history, quite a few grids have been attempted to tackle these problems and reduced grid is the simplest one among other grids. However, the reduced grid is almost abandoned by modern numerical modellers due to its unsatisfactory results for dynamical models in the polar region. Spherical multiple-cell (SMC) grid is similar to the reduced grid apparently but uses the unstructured technique for efficiency. It merges longitudinal cells at high latitudes like the reduced grid to overcome the CFL restriction and introduces a polar cell to remove the polar singularity. It also supports quad-tree-like mesh refinement to form a multi-resolution grid. To tackle the vector polar problem associated with the increased curvature at high latitudes, the SMC grid uses a new fixed reference direction to define vector components near the poles for improved polar performance. Global transportation is quite efficient on the SMC grid with optional second or third order transportation scheme. Present applications of the SMC grid, particularly in ocean surface wave models, are presented and possible future usage in global models and coupled systems are proposed.
15
d’Adamo, Alessandro, Matteo Riccardi, Massimo Borghi, and Stefano Fontanesi. "CFD Modelling of a Hydrogen/Air PEM Fuel Cell with a Serpentine Gas Distributor." Processes 9, no. 3 (2021): 564. http://dx.doi.org/10.3390/pr9030564.
Full textAbstract:
Hydrogen-fueled fuel cells are considered one of the key strategies to tackle the achievement of fully-sustainable mobility. The transportation sector is paying significant attention to the development and industrialization of proton exchange membrane fuel cells (PEMFC) to be introduced alongside batteries, reaching the goal of complete de-carbonization. In this paper a multi-phase, multi-component, and non-isothermal 3D-CFD model is presented to simulate the fluid, heat, and charge transport processes developing inside a hydrogen/air PEMFC with a serpentine-type gas distributor. Model results are compared against experimental data in terms of polarization and power density curves, including an improved formulation of exchange current density at the cathode catalyst layer, improving the simulation results’ accuracy in the activation-dominated region. Then, 3D-CFD fields of reactants’ delivery to the active electrochemical surface, reaction rates, temperature distributions, and liquid water formation are analyzed, and critical aspects of the current design are commented, i.e., the inhomogeneous use of the active surface for reactions, limiting the produced current and inducing gradients in thermal and reaction rate distribution. The study shows how a complete multi-dimensional framework for physical and chemical processes of PEMFC can be used to understand limiting processes and to guide future development.
16
Tang, Yikai, Xing Huang, Yanju Li, Haoran Ma, Kai Zhang, and Ke Song. "Degradation Prediction of Proton Exchange Membrane Fuel Cell Based on Multi-Head Attention Neural Network and Transformer Model." Energies 18, no. 12 (2025): 3177. https://doi.org/10.3390/en18123177.
Full textAbstract:
Proton exchange membrane fuel cells are a clean energy technology with wide application in transportation and stationary energy systems. Due to the problem of voltage degradation under long-term dynamic loads, predicting their performance degradation trend is of great significance for extending the life of proton exchange membrane fuel cells and improving system reliability. This study adopts a data-driven approach to construct a degradation prediction model. In view of the problem of many input parameters and complex distribution of degradation features, a neural network model based on a multi-head attention mechanism and class token is first proposed to analyze the impact of different operating parameters on the output voltage prediction. The importance of each input variable is quantified by the attention weight matrix to assist feature screening. Subsequently, a prediction model is constructed based on Transformer to characterize the voltage degradation trend of fuel cells under dynamic conditions. The experimental results show that the root mean square error and mean absolute error of the model in the test phase are 0.008954 and 0.006590, showing strong prediction performance. Based on the importance evaluation provided by the first model, 11 key parameters were selected as inputs. After this input simplification, the model still maintained a prediction accuracy comparable to that of the full-feature model. This result verifies the effectiveness of the feature screening strategy and demonstrates its contribution to improved generalization and robustness.
17
Yin, Beibei, Ping Lu, Jing Liang, et al. "The ABCB1 3435C > T polymorphism influences docetaxel transportation in ovarian cancer." Journal of International Medical Research 47, no. 10 (2019): 5256–69. http://dx.doi.org/10.1177/0300060519870354.
Full textAbstract:
Objective To investigate the effect of the ATP-binding cassette transporter superfamily B member 1 gene ( ABCB1) 3435C > T single nucleotide polymorphism (SNP) on docetaxel transportation in ovarian cancer cells. Methods ES-2 and SKOV3 cells were transfected with an ABCB1 3435C > T recombinant plasmid, and mRNA expression was detected by real-time PCR. The MTT assay was used to detect the toxicity of docetaxel. High-performance liquid chromatography determined the drug concentration in different cell models to evaluate intracellular accumulation, and a transmembrane resistance experiment was used to assess permeability and evaluate the effect of P-gp activity on drug transportation. A tumor-bearing mouse model was established to evaluate the effect of ABCB1 3435C > T on docetaxel resistance. Results P-gp was overexpressed in cells transfected with the ABCB1 3435C > T plasmid, leading to a significant increase in drug resistance to docetaxel. ABCB1 3435C/wild-type transfection significantly promoted the transport of docetaxel mediated by P-gp compared with ABCB1 3435T/mutant transfection. Conclusion P-gp encoded by the ABCB1 variant allele appears to be more efficient at transporting docetaxel compared with the wild-type allele. The ABCB1 3435C > T SNP dramatically affected the efflux ability of P-gp against docetaxel, and may influence P-gp expression and activity.
18
Paul, Abigail, Regan Magee, Warren Wilczewski, et al. "Characterization and Analysis of Coal-Derived Graphite for Lithium-Ion Batteries." ECS Meeting Abstracts MA2024-01, no. 4 (2024): 670. http://dx.doi.org/10.1149/ma2024-014670mtgabs.
Full textAbstract:
Graphite is a critical material used as the negative electrode in lithium-ion batteries. Both natural and synthetic graphites are utilized, with the latter obtained from a range of carbon raw materials. In this work, efforts to synthesize graphite from coal as a domestic feedstock for synthetic graphite are reported. The performance in lithium-ion coin cells of this coal derived graphite is compared to commercial battery-grade graphite. This includes characterization of the thermodynamics of the coal derived graphite using the multi-species, multi-reaction (MSMR) model, characterization of the entropy and enthalpy of the material, and estimation of the rate capability. This enables modeling of synthetic coal-derived graphites and virtual evaluation[1] of these materials towards electric vehicle and grid storage applications. References 1. T. R. Garrick, Y. Zeng, J. B. Siegel, and V. R. Subramanian, "From Atoms to Wheels: The Role of Multi-Scale Modeling in the Future of Transportation Electrification." Journal of The Electrochemical Society 170.11 (2023): 113502.
19
Kamilar, Victoria, Sarah West, Brittni P. Littlejohn, et al. "Evaluation of Prenatal Transportation Stress on the Number of Pituitary Corticotrophs in Mature Brahman Cows." Journal of Animal Science 99, Supplement_2 (2021): 24–25. http://dx.doi.org/10.1093/jas/skab096.043.
Full textAbstract:
Abstract Prenatal transportation stress (PNS) results in calves that are more temperamental and have greater circulating concentrations of cortisol compared to control calves. The objective of this experiment was to evaluate whether PNS alters the number of pituitary corticotrophs in mature Brahman cows. We hypothesized that the increased circulating cortisol concentrations previously characterized in this bovine model is associated with developmental changes in the anterior pituitary leading to an increased number of corticotrophs. Pregnant Brahman cows (n = 48) were transported in trailers for 2-hour periods at 60±5, 80±5, 100±5, 120±5, and 140±5 days of gestation. Non-transported pregnant cows (n = 48) were designated as the Control group. Control and PNS offspring heifers were managed together under the same environmental conditions. At approximately 5 yr of age, randomly selected non-pregnant cows (Control, n = 8; PNS, n = 6) were humanely harvested and the whole pituitaries were collected. Pituitaries were weighed, fixed in paraformaldehyde, serially dehydrated with graded ethanol, embedded in paraffin blocks, and cut into 5-μm sections. Immunohistochemistry was performed to detect cells expressing adrenocorticotropic hormone (ACTH) as a marker for corticotrophs. Three comparable sections from the midsagittal plane from each animal were processed using an ovine ACTH-specific antibody (Dr. A.F. Parlow, NIDDK). Five fields of view were analyzed per section (15 fields per animal). Anterior pituitary gland weight did not differ (P > 0.10) between groups (Control = 2.11 ± 0.12 g; PNS = 2.10 ± 0.15 g). The mean number of ACTH-positive cells between control (531±56 cells/section) and PNS cows (477±49 cells/section) also did not differ (P > 0.10). In conclusion, the number of pituitary corticotrophs in mature Brahman cows was not affected by prenatal transportation stress and is likely not a mechanism mediating the increased circulating cortisol concentrations seen in this bovine model of fetal programming.
20
Wang, Yongqing, Xingchen Li, Zhenning Guo, Ke Wang, and Yan Cao. "Effect of the Reactant Transportation on Performance of a Planar Solid Oxide Fuel Cell." Energies 14, no. 4 (2021): 1212. http://dx.doi.org/10.3390/en14041212.
Full textAbstract:
The process of reactant transportation greatly affects the performance of solid oxide fuel cells (SOFCs). Therefore, a three-dimension numerical SOFC model was built to evaluate mainly the effect of the reactant transportation coupling of heat and mass transfer and electrochemical reactions, and the reliability of numerical calculations was validated. Numerical studies revealed the correlation of both increase of reactant concentration gradients and improved mass transfer capability of multi reactants in gas diffusion electrode with the enhancement of the SOFC performance, in the condition of enough supplies of the fuel and the oxidant. Further studies identified the oxygen ions conductivity in electrolytes played a critical role in energy output and thus the performance of SOFCs. For example, the current density would increase by 65% if the ionic conductivity of electrolytes doubled. This study gives insight into the significance of operational conditions, electrolytes, and structures on the ionic oxygen conductivity and further on the optimization of the SOFCs. Overall, the numerical modeling leads a clear path toward the optimization of SOFCs.
21
Bhoopal, Neerudi, Dokku Sivanaga Malleswara Rao, Nagineni Venkata Sireesha, Idamakanti Kasireddy, Ranjith Kumar Gatla, and Devineni Gireesh Kumar. "Modelling and Performance Evaluation of 18w PEM Fuel Cell Considering H2 Pressure Variations." Journal of New Materials for Electrochemical Systems 25, no. 1 (2022): 1–6. http://dx.doi.org/10.14447/jnmes.v25i1.a01.
Full textAbstract:
The chemical energy of a hydrogen-oxygen reaction is converted directly into dc electrical energy by fuel cells (FC). PEMFCs (Proton Exchange Membrane Fuel Cells) are a feasible alternative for electrical transportation and stationary applications. This paper presented a PEMFC modelling approach using Artificial Intelligence. The main objective of this research is to build a model of an 18w Polymer Electrolyte Membrane (PEM) fuel cell and test its performance under different hydrogen pressure conditions. The physical model of the 18W hydrogen fueled PEM fuel cell is designed and tested at BHEL R&D. Additionally, a method for predicting a PEMFC's operating temperature using the voltage and current measures is suggested and successfully tested. However, the proposed technique is validated using experimental data from an 18W fuel cell. The analytical data and testing procedures required for determining the parameter values used in the proposed model are specified.
22
Luo, Zixuan, Yang Hu, Huachi Xu, Danhui Gao, and Wenying Li. "Cost-Economic Analysis of Hydrogen for China’s Fuel Cell Transportation Field." Energies 13, no. 24 (2020): 6522. http://dx.doi.org/10.3390/en13246522.
Full textAbstract:
China has become a major market for hydrogen used in fuel cells in the transportation field. It is key to control the cost of hydrogen to open up the Chinese market. The development status and trends of China’s hydrogen fuel industry chain were researched. A hydrogen energy cost model was established in this paper from five aspects: raw material cost, fixed cost of production, hydrogen purification cost, carbon trading cost, and transportation cost. The economic analysis of hydrogen was applied to hydrogen transported in the form of high-pressure hydrogen gas or cryogenic liquid hydrogen and produced by natural gas, coal, and electrolysis of water. It was found that the cost of hydrogen from natural gas and coal is currently lower, while it is greatly affected by the hydrogen purification cost and the carbon trading price. Considering the impact of future production technologies, raw material costs, and rising requirements for sustainable energy development on the hydrogen energy cost, it is recommended to use renewable energy curtailment as a source of electricity and multi-stack system electrolyzers as large-scale electrolysis equipment, in combination with cryogenic liquid hydrogen transportation or on-site hydrogen production. Furthermore, participation in electricity market-oriented transactions, cross-regional transactions, and carbon trading can reduce the cost of hydrogen. These approaches represent the optimal method for obtaining inexpensive hydrogen.
23
Toon, Bogaerts, D. Masegosa Antonio, S. Angarita-Zapata Juan, Onieva Enrique, and Hellinckx Peter. "A graph CNN-LSTM neural network for short and long-term traffic forecasting based on trajectory data." Transportation Research Part C: Emerging Technologies 112 (January 29, 2020): 62–77. https://doi.org/10.1016/j.trc.2020.01.010.
Full textAbstract:
Traffic forecasting is an important research area in Intelligent Transportation Systems that is focused on anticipating traffic in order to mitigate congestion. In this work we propose a deep neural network that simultaneously extracts the spatial features of traffic, using graph convolution, and its temporal features by means of Long Short Term Memory (LSTM) cells to make both short-term and long-term predictions. The model is trained and tested using sparse trajectory (GPS) data coming from the ride-hailing service of DiDi in the cities of Xi'an and Chengdu in China. Besides, presenting the deep neural network, we also propose a data-reduction technique based on temporal correlation to select the most relevant road links to be used as input. Combining the suggested approaches, our model obtains better results compared to high-performance algorithms for traffic forecasting, such as LSTM or the algorithms presented in the TRANSFOR19 forecasting competition. The model is capable of maintaining its performance over different time-horizons from 5 minutes to up to 4 hours with multi-step predictions.
24
Wang, Yiqing, Chong Wu, and Hailong Gao. "Dynamic scheduling of hydrogen-containing integrated energy systems considering multi-energy transactions." Journal of Physics: Conference Series 2614, no. 1 (2023): 012007. http://dx.doi.org/10.1088/1742-6596/2614/1/012007.
Full textAbstract:
Abstract With the continuous development of hydrogen energy production and storage technology, hydrogen energy has gradually become one of the clean energy sources with acceptable cost. The hydrogen decarbonization process of natural gas pipeline transportation and its end energy units such as fuel cells is gradually accelerated. For this reason, considering a variety of energy markets, this paper establishes the operation scheduling model of the integrated energy system (IES) of combined cooling, heating, and power (CCHP) supply with the solid oxide fuel cell (SOFC) as the core which is compared with the traditional gas turbine cogeneration system in the economy and carbon emission reduction and introduces the model predictive control (MPC) algorithm to solve the rolling optimal scheduling scheme. The scheduling results show that the addition of hydrogen conversion units can effectively solve the phenomenon of light abandonment. Under the current energy price, when the proportion of photovoltaic (PV) installed capacity is greater than 0.33, the energy storage potential of hydrogen conversion units can be fully utilized and the economic benefits of SOFC co-production are better than gas turbines. After taking into account the high carbon emission factor of the power grid, there is no big difference in the carbon emission costs of the two cogeneration methods. When the carbon emission factor of the power grid is lower than 0.3 and the hydrogen production efficiency is higher than 75%, the carbon emission reduction benefits of SOFC have obvious advantages.
25
Riccardi, Matteo, Alessandro d’Adamo, Andrea Vaini, Marcello Romagnoli, Massimo Borghi, and Stefano Fontanesi. "Experimental Validation of a 3D-CFD Model of a PEM Fuel Cell." E3S Web of Conferences 197 (2020): 05004. http://dx.doi.org/10.1051/e3sconf/202019705004.
Full textAbstract:
The growing energy demand is inevitably accompanied by a strong increase in greenhouse gas emissions, primarily carbon dioxide. The adoption of new energy vectors is therefore seen as the most promising countermeasure. In this context, hydrogen is an extremely interesting energy carrier, since it can be used as a fuel in both conventional energy systems (internal combustion engines, turbines) and in Fuel Cells (FC). In particular, PEM (Polymeric Electrolyte Membrane) FC are given growing attention in the transportation sector as a Life-Cycle viable solution to sustainable mobility. The use of 3D CFD analysis of for the development of efficient FC architectures is extremely interesting since it can provide a fast development tool for design exploration and optimization. The designer can therefore take advantage of a robust and accurate modelling in order to define and develop fuel cell systems in a more time-efficient and cost-efficient way, to optimize their performance and to lower their production costs. So far, studies available in the scientific literature lack of quantitative validation of the CFD simulations of complete PEM fuel cells against experimental evidence. The proposed study presents a quantitative validation of a multi-physics model of a Clearpak PEM cell. The chemistry and physics implemented in the methodology allow the authors to obtain both thermal and electrical results, characterizing the performance of each component of the PEM. The results obtained, compared with the experimental polarization curve, show that the model is not only numerically stable and robust in terms of boundary conditions, but also capable to accurately characterize the performance of the PEM cell over almost its entire polarization range.
26
Di Luca, Alessio, Andrea Ianni, Michael Henry, Camillo Martino, Paula Meleady, and Giuseppe Martino. "Label-free quantitative proteomics and stress responses in pigs—The case of short or long road transportation." PLOS ONE 17, no. 11 (2022): e0277950. http://dx.doi.org/10.1371/journal.pone.0277950.
Full textAbstract:
Ethical livestock production is currently a major concern for consumers. In parallel, research has shown that transport duration is an important factor affecting animal welfare and has a negative impact on the final product quality and on the production cost. This study applied proteomics methods to the animal stress/welfare problem in pigs muscle-exudate with the aim to identify proteins indicative of molecular processes underpinning transport stress and to better characterise this species as a biomedical model. A broader perspective of the problem was obtained by applying label-free LC-MS to characterise the proteome response to transport stress (short or long road transportation) in pigs within the same genetic line. A total of 1,464 proteins were identified, following statistical analysis 66 proteins clearly separating pigs subject to short road transportation and pigs subject long road transportation. These proteins were mainly involved in cellular and metabolic processes. Catalase and stress-induced phosphoprotein-1 were further confirmed by Western blot as being involved in the process of self-protection of the cells in response to stress. This study provide an insight into the molecular processes that are involved in pig adaptability to transport stress and are a step-forward for the development of an objective evaluation method of stress in order to improve animal care and management in farm animals.
27
Nehete, Pramod N., Bharti P. Nehete, Akash G. Patel, Sriram Chitta, Henrieta Scholtzova, and Lawrence E. Williams. "Short-Term Relocation Stress-Induced Hematological and Immunological Changes in Saimiri boliviensis boliviensis." Journal of Immunology Research 2021 (November 8, 2021): 1–12. http://dx.doi.org/10.1155/2021/5318590.
Full textAbstract:
Nonhuman primates are frequently transported to a new location or temporarily relocated within their colony. Both transportation and relocation expose animals to new environments, causing them to undergo a stress response (before adapting). In our NHP colony, the mentioned situations are not infrequent for many reasons, including maintenance. The objective of this study was to determine whether abrupt changes consisting of relocation, housing, separation, and grouping could influence hematological and immunological parameters and thereby functional activity. The current study used squirrel monkeys as a model to investigate the stress-inducing effects of relocation within a facility, while animals acclimated to new situations (physical, housing). A detailed blood analysis revealed significant changes in lymphocytes, triglycerides, total protein, creatinine, and ALT. Flow cytometric analysis of peripheral blood showed reduction in CD3+, CD4+, and CD8+ T cells and monocytes, while B cells and natural killer (NK) cells changed with relocation. Simultaneously, changes in functional activity of immune cells altered proliferative responses and as shown by ELISpot (IFN γ). Though the parameters studied are not affected as severely as those in animals transported by road or air, stress responses induced by intrafacility relocation are significant and worth consideration. Our findings indicate that squirrel monkeys mimic the features seen in humans exposed to social stressors and may serve an important model for understanding the mechanisms of stress-induced immune dysfunction in humans.
28
Zuo, Lingyan, Weiqian Li, Jifang Shi, Yingzhen Su, Hongyan Shuai, and Xin Yu. "SynB3 Conjugated QBP1 Passes Blood-Brain Barrier Models and Inhibits PolyQ Protein Aggregation." Protein & Peptide Letters 29, no. 1 (2022): 110–20. http://dx.doi.org/10.2174/0929866529666211221163930.
Full textAbstract:
Background: Polyglutamine diseases are degenerative diseases in the central nervous system caused by CAG trinucleotide repeat expansion which encodes polyglutamine tracts, leading to the misfolding of pathological proteins. Small peptides can be designed to prevent polyglutamine diseases by inhibiting the polyglutamine protein aggregation, for example, polyglutamine binding peptide 1(QBP1). However, the transportation capability of polyglutamine binding peptide 1 across the blood-brain barrier is less efficient. We hypothesized whether its therapeutic effect could be improved by increasing the rate of membrane penetration. Objectives: The objective of the study was to explore whether polyglutamine binding peptide 1 conjugated cell-penetrating peptides could pass through the blood-brain barrier and inhibit the aggregation of polyglutamine proteins. Methods: In order to investigate the toxic effects, we constructed a novel stable inducible PC12 cells to express Huntington protein that either has 11 glutamine repeats or 63 glutamine repeats to mimic wild type and polyglutamine expand Huntington protein, respectively. Both SynB3 and TAT conjugated polyglutamine binding peptide 1 was synthesized, respectively. We tested their capabilities to pass through a Trans-well system and subsequently studied the counteractive effects on polyglutamine protein aggregation. Results: The conjugation of cell-penetrating peptides to SynB3 and TAT enhanced the transportation of polyglutamine binding peptide 1 across the mono-cell layer and ameliorated polyglutamine-- expanded Huntington protein aggregation; moreover, SynB3 showed better delivery efficiency than TAT. Interestingly, it has been observed that polyglutamine binding peptide 1 specifically inhibited polyglutamine-expanded protein aggregation rather than affected other amyloidosis proteins, for example, β-Amyloid. Conclusion: Our study indicated that SynB3 could be an effective carrier for polyglutamine binding peptide 1 distribution through the blood-brain barrier model and ameliorate the formation of polyglutamine inclusions; thus SynB3 conjugated polyglutamine binding peptide 1 could be considered as a therapeutic candidate for polyglutamine diseases.
29
Zhu, Yuanchen, Travis Robinson, Amani Al-Othman, André Y. Tremblay, and Marten Ternan. "n-Hexadecane Fuel for a Phosphoric Acid Direct Hydrocarbon Fuel Cell." Journal of Fuels 2015 (April 1, 2015): 1–9. http://dx.doi.org/10.1155/2015/748679.
Full textAbstract:
The objective of this work was to examine fuel cells as a possible alternative to the diesel fuel engines currently used in railway locomotives, thereby decreasing air emissions from the railway transportation sector. We have investigated the performance of a phosphoric acid fuel cell (PAFC) reactor, with n-hexadecane, C16H34 (a model compound for diesel fuel, cetane number = 100). This is the first extensive study reported in the literature in which n-hexadecane is used directly as the fuel. Measurements were made to obtain both polarization curves and time-on-stream results. Because deactivation was observed hydrogen polarization curves were measured before and after n-hexadecane experiments, to determine the extent of deactivation of the membrane electrode assembly (MEA). By feeding water-only (no fuel) to the fuel cell anode the deactivated MEAs could be regenerated. One set of fuel cell operating conditions that produced a steady-state was identified. Identification of steady-state conditions is significant because it demonstrates that stable fuel cell operation is technically feasible when operating a PAFC with n-hexadecane fuel.
30
Hu, Xiao, Shikun Liu, Ke Song, Yuan Gao, and Tong Zhang. "Novel Fuzzy Control Energy Management Strategy for Fuel Cell Hybrid Electric Vehicles Considering State of Health." Energies 14, no. 20 (2021): 6481. http://dx.doi.org/10.3390/en14206481.
Full textAbstract:
Due to the low efficiency and high pollution of conventional internal combustion engine vehicles, the fuel cell hybrid electric vehicles are expected to play a key role in the future of clean energy transportation attributed to the long driving range, short hydrogen refueling time and environmental advantages. The development of energy management strategies has an important impact on the economy and durability, but most strategies ignore the aging of fuel cells and the corresponding impact on hydrogen consumption. In this paper, a rule-based fuzzy control strategy is proposed based on the constructed data-driven online estimation model of fuel cell health. Then, a genetic algorithm is used to optimize this fuzzy controller, where the objective function is designed to consider both the economy and durability by combining the hydrogen consumption cost and the degradation cost characterized by the fuel cell health status. Considering that the rule-based strategy is more sensitive to operating conditions, this paper uses an artificial neural network for predictive control. The results are compared with those obtained from the genetic algorithm optimized fuzzy controller and are found to be very similar, where the prediction accuracy is assessed using MAPE, RMSE and 10-fold cross-validation. Experiments show that the developed strategy has a good generalization capability for variable driving cycles.
31
Abdelmalek, Zahra, Sami Ullah Khan, Hassan Waqas, Hossam A. Nabwey, and Iskander Tlili. "Utilization of Second Order Slip, Activation Energy and Viscous Dissipation Consequences in Thermally Developed Flow of Third Grade Nanofluid with Gyrotactic Microorganisms." Symmetry 12, no. 2 (2020): 309. http://dx.doi.org/10.3390/sym12020309.
Full textAbstract:
In recent decades, an interest has been developed towards the thermal consequences of nanofluid because of utilization of nano-materials to improve the thermal conductivity of traditional liquid and subsequently enhance the heat transportation phenomenon. Following this primarily concept, this current work investigates the thermal developed flow of third-grade nanofluid configured by a stretched surface with additional features of activation energy, viscous dissipation and second-order slip. Buongiorno’s nanofluid model is used to explore the thermophoresis and Brownian motion features based on symmetry fundamentals. It is further assumed that the nanoparticles contain gyrotactic microorganisms, which are associated with the most fascination bioconvection phenomenon. The flow problem owing to the partial differential equations is renovated into dimensional form, which is numerically simulated with the help of bvp4c, by using MATLAB software. The aspects of various physical parameters associated to the current analysis are graphically examined against nanoparticles’ velocity, temperature, concentration and gyrotactic microorganisms’ density distributions. Further, the objective of local Nusselt number, local Sherwood number and motile density number are achieved numerically with variation of various parameters. The results presented here may find valuable engineering applications, like cooling liquid metals, solar systems, power production, solar energy, thermal extrusion systems cooling of machine equipment, transformer oil and microelectronics. Further, flow of nanoparticles containing gyrotactic microorganisms has interesting applications in microbial fuel cells, microfluidic devices, bio-technology and enzyme biosensors.
32
Zhang, Qi, Yang Zhe, Xiaoqing Wu, Lan Lan, Lanjing Wei, and Liang Xu. "Abstract 4173: Improve anti-PD-1 immunotherapy response in immunologically cold tumors by harnessing RNA-binding protein HuR." Cancer Research 82, no. 12_Supplement (2022): 4173. http://dx.doi.org/10.1158/1538-7445.am2022-4173.
Full textAbstract:
Abstract Cancer immunotherapy, especially those targeting the immune checkpoint PD-1 and PD-L1 has emerged as a revolutionizing treatment modality. Immune checkpoint inhibitors (ICIs)-mediated anti-tumor response depends on T cell capability of recognizing and killing tumor cells. ‘Hot’ tumors, which are characterized by the T cell infiltration, show a better response rate to immune checkpoint blockade (ICB) treatment. In contrast, ‘Cold’ tumors have a particularly low objective response rate (ORR) to ICB. In consideration of the durable and impressive responses observed in ‘hot’ tumors, it will be valuable to make an endeavor to turn immunologically cold tumors into hot tumors. The RNA-binding protein HuR is a member of the embryonic lethal abnormal vision (ELAV) family that is overexpressed in a variety of cancers and promotes tumorigenesis by interacting with a subset of oncogenic mRNAs. In this study, we show the direct binding of HuR protein to PD-L1 mRNA in multiple types of cells by Ribonucleoprotein immunoprecipitation (RNP-IP) and further validated by RNA pulldown assay. We also show that PD-L1 mRNA decay is greatly expedited in HuR-knockout cells, which underlines the stabilization function of HuR on PD-L1 transcripts. Immunoblotting results demonstrate that PD-L1 protein expression level is decreased in HuR-knockout cells while up-regulated in HuR-proficient cells in comparison with control. These data together clarify HuR is engaged in PD-L1 post-transcription regulation. Based on this mechanism, we develop a combination strategy using HuR inhibitors and anti-PD1 antibodies to overcome the limitation by regulating the tumor immune microenvironment. KH-200 is a compound that disrupts the transportation of HuR from nuclear to cytoplasm. To test the combination strategy in vivo, we established the EMT6 syngeneic breast cancer model. After 4-week treatment, the combination group shows great effects in inhibiting tumor growth and prolonging survival. A similar combination effect was further observed in Lewis lung syngeneic lung cancer model. In conclusion, we preliminarily explored the role of HuR in tumor immune evasion. The method using HuR inhibitors as a combination in immunotherapy shows effectiveness in immunologically cold tumor treatment and may have reference significance for clinical cancer therapy. Citation Format: Qi Zhang, Yang Zhe, Xiaoqing Wu, Lan Lan, Lanjing Wei, Liang Xu. Improve anti-PD-1 immunotherapy response in immunologically cold tumors by harnessing RNA-binding protein HuR [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4173.
33
Ben Hamad, Khlid, Doudou N. Luta, and Atanda K. Raji. "A Grid-Tied Fuel Cell Multilevel Inverter with Low Harmonic Distortions." Energies 14, no. 3 (2021): 688. http://dx.doi.org/10.3390/en14030688.
Full textAbstract:
As a result of global energy demand increase, concerns over global warming, and rapid exhaustion of fossil fuels, there is a growing interest in energy system dependence on clean and sustainable energy resources. Attractive power technologies include photovoltaic panels, wind turbines, and biomass power. Fuel cells are also clean energy units that substitute power generators based on fossil fuels. They are employed in various applications, including transportation, stationary power, and small portable power. Fuel cell connections to utility grids require that the power conditioning units, interfacing the fuel cells and the grids, operate accordingly (by complying with the grid requirements). This study aims to model a centralised, single-stage grid-tied three-level diode clamped inverter interfacing a multi-stack fuel cell system. The inverter is expected to produce harmonic distortions of less than 0.5% and achieve an efficiency of 85%. Besides the grid, the system consists of a 1.54 MW/1400 V DC proton exchange membrane fuel cell, a 1.3 MW three-level diode clamped inverter with a nominal voltage of 600 V, and an inductance-capacitance-inductance (LCL) filter. Two case studies based on the load conditions are considered to assess the developed system’s performance further. In case 1, the fuel cell system generates enough power to fully meet this load and exports the excess to the grid. In the other case, a load of 2.5 MW was connected at the grid-tied fuel cell inverter’s output terminals. The system imports the grid’s power to meet the 2.5 MW load since the fuel cell can only produce 1.54 MW. It is demonstrated that the system can supply and also receive power from the grid. The results show the developed system’s good performance with a low total harmonic distortion of about 0.12% for the voltage and 0.07% for the current. The results also reveal that the fuel cell inverter voltage and the frequency at the point of common coupling comply with the grid requirements.
34
Kaverinska, Anna, Nadiia Shevchenko, Aleksandr Osetsky, et al. "The Effect of Lyophilized and Frozen Umbilical Cord Cryoextract on L929 Cell Culture." Innovative Biosystems and Bioengineering 9, no. 1 (2025): 3–12. https://doi.org/10.20535/ibb.2025.9.1.313718.
Full textAbstract:
Background. The human umbilical cord is a promising source of biologically active substances with regenerative properties. However, the potential of lyophilized cryoextract from the umbilical cord for regenerative medicine, which could facilitate storage and transportation, remains unexplored. Therefore, it is important to study the effect of such cryoextracts using a cellular model. Objective. To evaluate the effect of lyophilized and frozen umbilical cord cryoextracts on the L929 cell line to assess their therapeutic potential. Methods. This study was conducted on L929 cell cultures. Cryoextracts from the human umbilical cord were obtained through cryoextraction and lyophilized forms at -80 and -20 °C. These extracts were added to Dulbecco's Modified Eagle Medium (DMEM) at three concentrations: 0.1, 0.5, and 1.0 mg/ml. The control groups included cells cultured in DMEM with and without fetal bovine serum. Cell morphology and monolayer confluency were observed. To assess the impact of the cryoextracts, several assays were performed: cell viability (adhesion), migration activity (scratch test), pinocytosis activity (neutral red uptake assay), metabolic activity (MTT assay), and (proliferation) population doubling time. Results. The addition of umbilical cord cryoextract and its lyophilized form at -80 °C was non-toxic to the cells. The most effective concentration was 0.1 mg/ml, which significantly stimulated cell adhesion and proliferation compared to the culture medium without fetal serum. The lyophilized cryoextract at -20 °C did not enhance cell viability but did increase pinocytosis activity. Conclusions. These findings suggest that umbilical cord cryoextract and its lyophilized form at -80 °C can be used as growth factors in cell line cultivation. The lyophilized cryoextract shows promise for use in conditions where specialized storage equipment is not available. However, the lyophilized form at -20 °C primarily stimulates pinocytosis activity and inhibits proliferation.
35
Shrestha, Y., A. Subedi, M. Sapkota, P. Paudel, N. K. Yadav, and B. S. Thapa. "Assessing the performance of a demonstrative hydrogen fuel cell power train in the chassis of an internal combustion engine vehicle." IOP Conference Series: Materials Science and Engineering 1279, no. 1 (2023): 012003. http://dx.doi.org/10.1088/1757-899x/1279/1/012003.
Full textAbstract:
Abstract In the present day in the global context, approximately 2 billion internal combustion engines (ICEs) are estimated to be in use. Nearly 7.3 billion metric tons of carbon dioxide (CO2) were released into the atmosphere as per the survey on the transportation sector in 2020, making up 41% of all emissions. To solve pollution challenges related to ICEs, recent advancements of alternatives to ICEs have pushed the globe to establish clean energy sources such as hydrogen fuel cells. The conversion of an ICE vehicle to a fuel cell vehicle is able to add further support to its development besides the 30% emission reduction since the old ICE vehicle would not be discarded. FCEVs are seen as a true replacement between BEVs and ICEs since more energy can be stored in less space as compared to BEVs. The objective of this paper is to analyse the energy consumption of a fuel cell-driven motor in the internal combustion engine vehicle chassis of Maruti 800, through mathematical modelling, then compare the specifications with that of an ICE-driven system. The analysis provides details on the optimization of drive system components to maximise the fuel cell energy consumption efficiency based on fuel cell power source requirements for a range of velocities and road gradients. The modifiable specifications of drive system components in the mathematical model ensure reproducibility for any drive cycles and system scenarios.
36
Rabissi, Claudio, Gabriele Sordi, and Andrea Casalegno. "Physical Model-Based State of Health Understanding of Severely Aged Lithium-Ion Batteries Under Real-World Automotive Operational Life." ECS Meeting Abstracts MA2023-02, no. 2 (2023): 416. http://dx.doi.org/10.1149/ma2023-022416mtgabs.
Full textAbstract:
Lithium ion-battery (LIB) technology, featuring upstanding energy and power density, satisfying lifetime, high round-trip efficiency and very fast dynamics in a reasonably economic package, rapidly became the undisputed ruler of portable power and it is now the main driver of the electrification of transportation sector. However, despite the fully commercial development, understanding and predicting degradation of such devices is still a great challenge for the scientific and technical community, especially when dealing with real-life-operation induced aging. The reusability of such devices in a circular economy perspective is a hot topic to the sector to improve sustainability, but requires understanding “how” batteries are faded rather than only “how much” they are, to enable a physically consistent and second-life-related estimation of residual lifetime. In the present activity, a detailed analysis of high-power LFP (lithium iron phosphate) cells samples operated on IVECO hybrid buses are performed to assess their possible reusability, in the frame of a joint research cooperation. A large batch of cells with different ages (from 9 years old to brand new) and different positions inside the modules are investigated. State-of-art electrochemical diagnostics are performed embedded in a multi-measurement optimized protocol (full discharge, pulse test, electrochemical impedance spectroscopy) developed after a sensitivity optimization for a model-based improved parameter identification [1], as visible in Figure 1. Residual performances are analyzed and compared with limited on-board data collected from vehicles BMS and analyzed by means of an appositely-improved physical modelling platform. Both capacity and power capabilities have sensibly decreased over the cells lifetime (see Figure 2 for the full discharges at 0.1C, 25°C) with a clear pattern attributable to cells position beneath the modules, prompting the importance of a homogeneous thermal management during operation. Power-based state of health of the samples is higher than a capacity-based SoH, foreseeing a possible reuse of the samples in a power-intensive second-life. Residual performance interestingly feature a high consistency with data recently published in [2], relative to similar system despite operated in a completely different geographic area; this strengthens the generalizability of the results. Aged cells diagnostics were interpreted with a previously developed Newman P2D physical model provided with heath exchange, to identify the degradation mechanisms through the EIS-based parameter identification procedure [1] involving both thermodynamic and kinetic aspects. Interpretation of thermodynamic aging modes has been conducted on all the tested cell samples, based on 0.1C thermodynamic analysis and the differential voltage. Incremental capacity curves of aged cells have been reproduced with a PSO-based (particle-swarm-optimization) identification of three ageing parameters: loss of lithium inventory (LLI), mainly corresponding to solid electrolyte interphase (SEI) growth, and loss of active materials at negative (LAMn) and positive (LAMp) electrode, indicating loss of actives sites for the electrochemical reactions. Despite the severely low residual capacity, the model reproduces satisfyingly the features of the aged cells. Interestingly, a linear trend could be identified as common beneath all the samples involved in the analysis, indicating common aging mechanism appearing with different magnitude. As visible in Figure 3, the trend points out a two-steps aging path: (I) a first pathway mainly leading to LLI close to 20%, followed by (II) a second pathway with both LLI and LAMn occurring at the same time. In the literature, similar observations have been already performed by some authors in previous works, with a lower extent of degradation [3,4]. They agree in this interpretation: the first stage is usually associated to the growth of the SEI layer, while the second stage is usually associated to the onset of lithium plating (due to a dense SEI which inhibits the lithium intercalation into graphite). Confirmation of such interpretation is obtained by means of model based interpretation on non-equilibrium measurements, permitting estimation of physical parameters value and enabling identification of aging mechanisms, together with ex-situ measurements based on electrochemical and morpho chemical analyses. Additionally, several consistencies between on-line measurements, such as EIS, and equilibrium capacity loss of cells have been identified, theoretically discussed and tested under further accelerated aging tests, enabling possible strategies of SoH implementation based on fast and informative electrochemical measurements. References [1]Rabissi et al., doi.org/10.1016/j.est.2022.106435 [2] K. Ramirez-Meyers et al., doi.org/10.1016/j.est.2022.106472 [3] E. Sarasketa-Zabala et al., doi.org/10.1021/jp510071d [4] X.G. Yang et al., https://doi.org/10.1016/j.jpowsour.2017.05.110 Figure 1
37
Khedekar, Kaustubh, Andrea Zaffora, Plamen Atanassov, Lei Cheng, Christina Johnston, and Iryna V. Zenyuk. "Identical Location Mapping of Pt in Polymer Electrolyte Fuel Cells before and after Heavy-Duty Accelerated Stress Test." ECS Meeting Abstracts MA2022-02, no. 42 (2022): 1567. http://dx.doi.org/10.1149/ma2022-02421567mtgabs.
Full textAbstract:
Worldwide, governments and industries are pursuing the use of clean hydrogen to achieve zero emissions, especially for difficult to decarbonize sectors such as heavy-duty transportation, aviation, shipping and chemical manufacturing. Polymer electrolyte fuel cells (PEFCs) are an excellent candidate for heavy-duty vehicles (HDVs), particularly for their ability to scale range at a much smaller additional weight penalty1. However, initial system cost remains a significant challenge for large scale adoption mainly due to use of Platinum (Pt) electrocatalyst. Current approach to reduce initial cost by utilizing highly dispersed Pt nanoparticles (2-3 nm) adversely affects the system lifetime. The smaller nanoparticle size does result in improved Pt dispersion, which enhances performance and reduces Pt loading and cost. But smaller nanoparticles also tend to degrade faster due to higher surface energy, which negatively impacts durability1. During a HDV drive cycle, Pt nanoparticle surface undergoes repeated oxidation-reduction, which leads to dissolution of Pt ions causing loss in electrochemical surface area. The dissolved Pt ions can redeposit on nearby larger nanoparticles. This effect is known as electrochemical Ostwald ripening2. The Pt ions can also diffuse towards the anode and get reduced near the membrane-cathode interface by the crossover hydrogen to form a Pt band2. In addition, the Pt ions can leave the system via effluent water. The complex balance between cost, performance and durability of PEFCs makes understanding degradation mechanisms a priority. In this study, membrane electrode assemblies (MEAs) were subjected to accelerated stress tests (ASTs) to simulate heavy-duty lifetime. A simple method was developed to use micro-X-ray fluorescence spectroscopy to map identical locations of catalyst layer before and after the AST. The AST consisted of potential cycling between 0.6 V to 0.9 V (3s hold time each) for 90,000 cycles. Electrochemical characterization was performed at beginning of test, after 10k, 30k, 60k and 90k (end of test) AST cycles. The identical location maps revealed significant in-plane movement of Pt over the course of AST suggesting that electrochemical Ostwald ripening may not be a local effect. The in-plane movement of Pt led to development of local loading hotspots. A movement of Pt away from the cathode catalyst layer cracks was also observed. Such movement may be due to relative surface energy differences between the regions. A modified gas diffusion layer MEA was used to highlight the advantages and necessity of the method developed in this study. The modified MEA showed a ~13% change in/loss of Pt loading in the mapped region closer to the gas inlet. Identical location mapping allowed quantification of changes in the Pt loading caused by the AST. Lastly, identical location synchrotron micro-X-ray diffraction and florescence mapping was performed after the heavy-duty AST to identify correlation between Pt nanoparticle size growth and Pt loading. A direct correlation was observed, which developed only after the MEA was subjected to heavy-duty AST. References Cullen, D. A. et al. New roads and challenges for fuel cells in heavy-duty transportation. Nat. Energy 6, 462–474 (2021). Khedekar, K. et al. Probing Heterogeneous Degradation of Catalyst in PEM Fuel Cells under Realistic Automotive Conditions with Multi-Modal Techniques. Adv. Energy Mater. 11, (2021).
38
Wang, Yifan, James M. Fenton, and Paul Brooker. "Dynamic Modeling and Operation of a Green Hydrogen Fueling Station for Heavy-Duty Fuel Cell Vehicles." ECS Meeting Abstracts MA2023-01, no. 36 (2023): 1976. http://dx.doi.org/10.1149/ma2023-01361976mtgabs.
Full textAbstract:
Hydrogen fuel cell electric vehicles (FCEVs) have increased driving ranges and faster refueling times than battery electric vehicles (BEVs). The driving range of FCEVs can be increased by increasing the size, quantity or operating pressure of on-board hydrogen storage tanks at a lower weight and cost than increasing the size or number of Li-ion battery packs in BEVs. Ffast-refueling leads to less waiting time at the fueling station for high-utilization commercial vehicles. As a result, fuel cell system heavy-duty vehicles (HDV) are attracting more attention [1]. Currently, the lack of a hydrogen refueling infrastructure is limiting FCEV adoption. Since the driving routes of HDV trucks are more predictable, a small number of strategically located fueling stations could service pre-planned truck driving routes [2]. While hydrogen refueling protocols and fueling stations for light-duty vehicles (LDV) have been extensively studied [3,4,5], HDV trucks have different refueling protocols and operating conditions (e.g. mass holdup, pressure, refueling rate). To our knowledge, little work has been done on modeling hydrogen fueling stations for HDV trucks applications. With this motivation, a dynamic model of a truck stop coupled with green hydrogen production has been developed for fleet HDV trucks. At the truck stop, green hydrogen is produced from water electrolysis using solar photovoltaics (PV). Electrochemical hydrogen compression (EHC) is implemented for high-pressure hydrogen storage and dispensing. The fluctuations from solar PV and truck hydrogen demand are actively managed by installation of a spherical hydrogen storage vessel. The feasibility and flexibility of a truck stop using 100% renewable electricity and hydrogen will be discussed. A high-fidelity dynamic model of a Proton Exchange Membrane (PEM) electrolyzer is developed for hydrogen production from PV electricity. A PEM electrochemical hydrogen compressor model is developed for gas pressurization with consideration of EHC temperature and water management. The green hydrogen is stored in a large spherical storage vessel to decouple the different PV power loads and HDV trucks hydrogen refueling demands. A modular system for HDV trucks refueling (nominal working pressure of 35 MPa) is designed and modeled with parallel multi-stage hydrogen compression and cascaded storage tanks. It was found that single modular system for FCEV refueling shows a service gap during hydrogen cascaded storage tank refilling, but a multiple modular structure can be easily expanded and provide uninterrupted hydrogen for FCEV refueling. The different hydrogen production and dispensing scenarios are implemented depending on the seasonal solar supply and varied HDV trucks demands. Hydrogen compression using mechanical compressor and electrochemical compressor are compared. The truck stop operation strategies are proposed based on the integrated process systems analysis of solar penetrations, hydrogen production and compression, and HDV trucks demand. The feasibility and flexibility of truck stop fueled by solar energy provide an insight for the transition to Net Zero Emission Transportation. [1] Cullen, D.A., Neyerlin, K.C., Ahluwalia, R.K., Mukundan, R., More, K.L., Borup, R.L., Weber, A.Z., Myers, D.J. and Kusoglu, A. (2021). New roads and challenges for fuel cells in heavy-duty transportation. Nature energy, 6(5), 462-474. [2] Cano, Z. P., Banham, D., Ye, S., Hintennach, A., Lu, J., Fowler, M., & Chen, Z. (2018). Batteries and fuel cells for emerging electric vehicle markets. Nature Energy, 3(4), 279-289. [3] Xiao, L., Chen, J., Wu, Y., Zhang, W., Ye, J., Shao, S., & Xie, J. (2021). Effects of pressure levels in three-cascade storage system on the overall energy consumption in the hydrogen refueling station. International Journal of Hydrogen Energy, 46(61), 31334-31345. [4] Rothuizen, E., Mérida, W., Rokni, M., & Wistoft-Ibsen, M. (2013). Optimization of hydrogen vehicle refueling via dynamic simulation. International journal of hydrogen energy, 38(11), 4221-4231. [5] Rothuizen, E., & Rokni, M. (2014). Optimization of the overall energy consumption in cascade fueling stations for hydrogen vehicles. International journal of hydrogen energy, 39(1), 582-592.
39
Sharma, Preetam, Pierre Boillat, Lei Cheng, et al. "Water in Polymer Electrolyte Fuel Cells (PEFCs): Friend or Foe? Linking Preferential Catalyst Growth with Liquid Water Distribution in PEFCs." ECS Meeting Abstracts MA2024-01, no. 36 (2024): 2072. http://dx.doi.org/10.1149/ma2024-01362072mtgabs.
Full textAbstract:
With a recent emphasis on heavy-duty vehicle applications over light-duty, the performance targets for polymer electrolyte fuel cells (PEFCs) have become more demanding. For instance, achieving a net power output of 2.5 kW/g-PGM (1.07 A/cm2 current density) at 0.7 V is required after a 25,000-hour equivalent accelerated stress test (AST) [1]. In recent studies with traditional land/channel architecture, it has been demonstrated that Pt particle size growth is non-uniform and greater under flow field lands compared to channels [2]–[5]. It is hypothesized that preferential water accumulation under the lands during ASTs is responsible for such heterogeneity. However, a direct link between water accumulation/storage and particle size growth has not yet been established. In this study, we utilized high-resolution neutron radiography at NEUTRA, PSI, Switzerland to systematically map and quantify through-plane water content; synchrotron micro-XRD measured spatial Pt particle size distributions in fully functional fuel cells compatible with neutron imaging. The membrane electrode assemblies (MEAs) were aged using the U.S. Department of Energy’s (DOE) square-wave AST (0.6 V to 0.95 V vs. reversible hydrogen electrode, RHE) in both air and nitrogen environments at the cathode [5]. Correlations between through-plane water distribution and Pt particle size distribution maps were established for both pristine and aged samples. Understanding the role of architecture is crucial for assessing degradation, particularly in conventional flow fields where channel-land bias influences thermal and mass transport, impacting liquid water distribution. This knowledge can inform the design and engineering of PEFC components to enhance durability and reduce overall costs for vehicle applications. References: [1] D. A. Cullen, K. C. Neyerlin, R. K. Ahluwalia, R. Mukundan, K. L. More, R. L. Borup, A. Z. Weber, D. J. Myers, and A. Kusoglu, “New roads and challenges for fuel cells in heavy-duty transportation,” Nat Energy, vol. 6, pp. 462–474, 2021, doi: 10.1038/s41560-021-00775-z. [2] L. Cheng, K. Khedekar, M. Rezaei Talarposhti, A. Perego, M. Metzger, S. Kuppan, S. Stewart, P. Atanassov, N. Tamura, N. Craig, I. V. Zenyuk, and C. M. Johnston, “Mapping of Heterogeneous Catalyst Degradation in Polymer Electrolyte Fuel Cells,” Adv Energy Mater, vol. 2000623, pp. 1–7, 2020, doi: 10.1002/aenm.202000623. [3] K. Khedekar, M. R. Talarposhti, M. M. Besli, S. Kuppan, A. Perego, Y. Chen, M. Metzger, S. Stewart, P. Atanassov, N. Tamura, N. Craig, L. Cheng, C. M. Johnston, and I. V Zenyuk, “Probing Heterogeneous Degradation of Catalyst in PEM Fuel Cells under Realistic Automotive Conditions with Multi-Modal Techniques,” Adv Energy Mater, vol. 11, no. 35, p. 2101794, 2021, doi: 10.1002/aenm.202101794. [4] P. Sharma, B. Bera, D. Aaron, M. M. Besli, S. Kuppan, L. Cheng, J. Braaten, N. Craig, S. Stewart, M. Metzger, C. Johnston, and M. M. Mench, “Spatially Resolved Heterogeneous Electrocatalyst Degradation in Polymer Electrolyte Fuel Cells Subjected to Accelerated Aging Conditions,” J Electrochem Soc, vol. 169, no. 11, p. 114506, Nov. 2022, doi: 10.1149/1945-7111/ac9ee5. [5] P. Sharma, L. Cheng, D. Aaron, S. Mehrazi, J. Braaten, N. Craig, C. Johnston, and M. M. Mench, “Unveiling Local Aging Patterns Following Accelerated Stress Testing of High-Performance Polymer Electrolyte Fuel Cells,” Small, no. 2306433, 2023, doi: 10.1002/smll.202306433.
40
Azhar, Muhammad Al, and Mururul Aisyi. "Enhancing Pediatric Cancer Survival in Indonesia: The Role of CAR T Cell Therapy." Indonesian Journal of Cancer 18, no. 2 (2024): 114–15. http://dx.doi.org/10.33371/ijoc.v18i2.1238.
Full textAbstract:
Pediatric cancer poses a major health challenge globally, especially in low-middle-income countries like Indonesia. The survival rate of pediatric cancer in many high-income countries (HICs) reaches 90%, while it only ranges from 5 to 60% in LMICs. Over 80% of children with cancer live in low-middle-income countries, indicating the urgency to improve the survival rate of pediatric cancer in LMICs [1]. In Indonesia, the prevalence of pediatric cancer was 43.5% in 2020, making it the highest among Southeast Asian countries [2]. According to Dharmais Cancer Hospital (2024), the national cancer referral center for all of Indonesia, the 5-year survival rate of high-risk pediatric acute lymphoblastic leukemia is only 48.8% (unpublished data).One key factor contributing to the low survival rate of pediatric cancer in Indonesia is the lack of effective therapy options, especially for high-risk and relapsed or refractory patients. Several therapeutic approaches, such as immunotherapy, have been widely used in HICs but are still not very popular in Indonesia. CAR (Chimeric Antigen Receptor) T-cell therapy is one of the most promising immunotherapeutic approaches to treat pediatric cancer. Implementing CAR T Cell therapy in Indonesia offers promising prospects for improving the survival rates of pediatric cancer patients.CAR T cell therapy utilizes the body's immune system to specifically target and eliminate cancer cells. This innovative therapy entails extracting a patient's T cells, genetically modifying them to express chimeric antigen receptors specific to tumor-associated antigens, and then reinfusing them into the patient. Once infused, these engineered T cells recognize and eliminate cancer cells bearing the targeted antigen, thereby offering a highly targeted and potentially curative treatment option [3]. This innovative therapy has demonstrated remarkable success in treating certain hematologic malignancies, including pediatric leukemia. The most extensively studied case in childhood patients involves CAR T cells that target CD19, a B cell surface receptor [4].CAR T cell therapy holds great promise for improving survival rates among pediatric cancer patients in Indonesia. Children with refractory or relapsed leukemia, such as B-cell acute lymphoblastic leukemia (B-ALL), who have exhausted standard treatment options, can benefit from CAR T cell therapy. Most relapsed or refractory pediatric cancer patients in Indonesia do not have effective therapy options to treat the disease. CAR T cell therapy emerges as a novel therapy that can significantly improve the survival of this subset of patients. Numerous studies have documented high remission rates (ranging from 70% to 90%) in adults and children diagnosed with refractory B-ALL [4]. A study by Maude et al. [5] reported high remission rates and durable responses in young adults and children with refractory or relapsed B-ALL treated with CAR T cells. Similarly, Park et al. [6] demonstrated long-term remissions and improved survival in pediatric leukemia patients receiving CAR T cell therapy. Several groups also have observed the persistence of CAR T cells and sustained remission lasting over six months in the majority of patients examined [4]. Efforts have been made to implement CAR T cells in Indonesia. Dharmais Cancer Hospital, as a National Cancer Center in Indonesia, has initiated this effort by collaborating with iCarTAB Biomed Inc., a China-based CAR T cell manufacturer with one of its manufacturing sites located in Malaysia. However, this approach involves sending patients' blood samples that have been processed through leukapheresis to Malaysia for CAR T cell manufacturing, followed by the shipment of the manufactured cells back to Indonesia for administration to patients. This process is impractical and incurs intangible costs such as transportation and cryopreservation, ultimately making it more expensive for patients. Regulatory issues related to the shipment of cells across borders in the region and early preparation of patients for CAR T cell therapy soon after relapse before they succumb to treatment-related mortality or relapse-related complications are also challenges that need to be addressed [7]. Reflecting on the abovementioned issue, CAR T cell therapy adoption in Indonesia faces significant challenges. Limited healthcare infrastructure, including specialized facilities for cell therapy manufacturing and administration, poses logistical hurdles. Moreover, cost remains a major barrier, as CAR T cell therapy is often expensive and inaccessible to many patients in Indonesia. Furthermore, the lack of local expertise in cellular immunotherapy may impede the successful implementation of CAR T cell therapy programs.Efforts to address these challenges and maximize the potential of CAR T cell therapy in Indonesia are essential. This requires a multi-faceted approach involving investment in healthcare infrastructure, including establishing specialized centers equipped for CAR T cell therapy manufacturing and administration. Two alternative models have been proposed for manufacturing CAR-T cell therapy: centralized and de-centralized models [8]. In the centralized manufacturing model, point of manufacturing and point of care are located in different geographical areas, while decentralized manufacturing focuses on establishing point of care and manufacturing in close proximity. A decentralized manufacturing model might be the best approach to be implemented in LMICs like Indonesia. Building hospital-based cellular therapy manufacturing reduces the need for transportation and cryopreservation. The decentralized system's geographic proximity improves communication between manufacturing and treatment teams, facilitating the creation of customized products based on a patient's phenotype. This setup also reduces administration time and the risk of delays and mix-ups compared to centralized manufacturing, making hospital-based cellular therapy manufacturing a potentially more cost-effective option [8].In addition, initiatives to reduce the cost of therapy through partnerships with pharmaceutical companies, government subsidies, or philanthropic endeavors can improve affordability and access. Furthermore, capacity-building initiatives aimed at training local healthcare professionals in cellular immunotherapy techniques are essential for ensuring the successful implementation and sustainability of CAR T cell therapy programs in Indonesia. Collaboration between local institutions, international organizations, and industry stakeholders can facilitate knowledge transfer and technology transfer, fostering indigenous expertise in this cutting-edge treatment modality.CAR T cell therapy represents a transformative approach to improving survival rates among pediatric cancer patients in Indonesia. By harnessing the power of immunotherapy, specifically tailored to target cancer cells, CAR T cell therapy offers hope for children with refractory or relapsed leukemia who have limited treatment options. Through continued research, collaboration, and investment in healthcare infrastructure, CAR T cell therapy potentially could greatly improve the prognosis and quality of life for pediatric cancer patients in Indonesia.
41
Sharma, Preetam, Lei Cheng, Shirin Mehrazi, et al. "Investigating the Effects of Cascading Accelerated Stress Tests (ASTs) on the Localized Electrochemical Performance Degradation in Polymer Electrolyte Fuel Cells (PEFCs)." ECS Meeting Abstracts MA2023-01, no. 38 (2023): 2218. http://dx.doi.org/10.1149/ma2023-01382218mtgabs.
Full textAbstract:
With a recent shift in focus from light-duty to heavy-duty vehicle applications, the durability and performance targets for polymer electrolyte fuel cells (PEFCs) have become even more stringent and challenging to achieve; for example, a net power output of 2.5 kW/g-PGM (1.07 A/cm2 current density) at 0.7 V is required after 25,000 hour-equivalent accelerated stress test (AST) [1]. Generally, different ASTs are designed to evaluate Pt electrocatalyst and support durability; for example, a square-wave (SW) AST with H2/N2 between 0.6 V to 0.95 V vs. reversible hydrogen electrode (RHE) targets Pt catalyst and a separate triangular-wave (TW) AST with a higher potential range (1 – 1.5 V vs. RHE) assesses the durability of carbon-based supports [2]. Recently, many studies [3]–[7] have revealed the heterogeneous nature of cathode catalyst layer degradation under different ASTs. Fuel cell electric vehicles are typically subjected to an enormous number of load/unload and start/stop cycles during regular operation. Though there is a considerable body of literature discussing the isolated effects of load/unload and start/stop cycles on durability and performance, there is a dearth of studies exploring the effects of cascading load/unload and start/stop cycles, a scenario more relevant to actual automotive conditions. In the present study, a segmented cell along with ex-situ Pt particle size mapping (through micro-X-ray diffraction) is used to understand the effects of cascading a DoE square-wave AST (0.6 V to 0.95 V vs. RHE) and a triangular-wave (1 – 1.5 V vs. RHE) on the durability and performance of a PEFC. The membrane electrode assemblies (MEAs) are subjected to two cascade ASTs. The first one involves 15k cycles of SW AST followed by 2.5k cycles of TW AST (referred to as Pt-followed-by-carbon, PtfCC, AST) and the other one involves 2.5k cycles of TW AST followed by 15k cycles of SW AST (referred to as Carbon-followed-by-Pt, CCfPt, AST). Multiple in-situ and post-mortem ex-situ techniques are used to obtain particle size distribution and spatial degradation profiles. Preliminary results indicate that the performance losses at the end-of-life (EOL) depend on the cascade order; PtfCC AST leads to higher losses compared to CCfPt AST in wet polarization conditions. The local current distributions are also strongly impacted by the cascade order during the aging process. Figure 1 shows the polarization performance of the samples at the beginning, middle (following the first AST), and the end-of-life of cascade ASTs. References: [1] D. A. Cullen et al., “New roads and challenges for fuel cells in heavy-duty transportation,” Nat Energy, vol. 6, pp. 462–474, 2021, doi: 10.1038/s41560-021-00775-z. [2] S. Stariha et al., “Recent Advances in Catalyst Accelerated Stress Tests for Polymer Electrolyte Membrane Fuel Cells,” J Electrochem Soc, vol. 165, no. 7, pp. F492–F501, 2018, doi: 10.1149/2.0881807jes. [3] L. Cheng et al., “Mapping of Heterogeneous Catalyst Degradation in Polymer Electrolyte Fuel Cells,” Adv Energy Mater, vol. 2000623, pp. 1–7, 2020, doi: 10.1002/aenm.202000623. [4] K. Khedekar et al., “Probing Heterogeneous Degradation of Catalyst in PEM Fuel Cells under Realistic Automotive Conditions with Multi-Modal Techniques,” Adv Energy Mater, p. 2101794, doi: https://doi.org/10.1002/aenm.202101794. [5] P. Sharma et al., “Spatially Resolved Heterogeneous Electrocatalyst Degradation in Polymer Electrolyte Fuel Cells Subjected to Accelerated Aging Conditions,” J Electrochem Soc, vol. 169, no. 11, p. 114506, Nov. 2022, doi: 10.1149/1945-7111/ac9ee5. [6] P. Sharma et al., “Influence of Flow Rate on Catalyst Layer Degradation in Polymer Electrolyte Fuel Cells,” ECS Meeting Abstracts, vol. MA2020-0, no. 36, p. 2345, Nov. 2020, doi: 10.1149/ma2020-02362345mtgabs. [7] P. Sharma et al., “Localized Electrochemical Performance Degradation in Polymer Electrolyte Fuel Cells (PEFCs),” ECS Meeting Abstracts, vol. MA2022-02, no. 42, pp. 1571–1571, Oct. 2022, doi: 10.1149/MA2022-02421571mtgabs. Figure 1
42
Hou, Pingping, Ting-yu Chu, Yuemeng Huang, Daiyong Deng, and Habeebunnisa Begum. "Abstract 1594: Lipid-laden macrophages are associated with KRAS therapy resistance in pancreatic cancer." Cancer Research 85, no. 8_Supplement_1 (2025): 1594. https://doi.org/10.1158/1538-7445.am2025-1594.
Full textAbstract:
Our recent discovery in pancreatic ductal adenocarcinoma (PDAC) demonstrates that tumor-associated macrophages (TAMs) are pivotal in driving resistance to KRAS-targeted therapy. Using a genetically engineered mouse (GEM) model of PDAC with doxycycline-inducible KRASG12D, pancreas-specific p48-Cre, and conditional p53 knockout (known as "iKPC"), we found that myeloid cell remodeling from a neutrophil-rich to a macrophage-rich phenotype occurred after KRAS depletion. TAMs were sufficient and essential for PDAC cells to bypass KRAS dependency. Consistent with our findings, KRAS inhibition (KRASi) rewired the tumor microenvironment (TME) with increased TAM presence in several cancer models, including those of the pancreas, colon, and lung. However, the exact role of TAMs in promoting or impairing KRASi resistance remains controversial. Considering the heterogeneous, plastic, and multi-functional features of TAMs, we performed single-cell RNA sequencing (scRNA-seq) to compare KRAS on and off tumors from iKPC GEM. We identified two major subclusters of TAMs: Siglecf+ and Apoe+, with only Apoe+ TAMs expressing high levels of Ccr2, indicating their origin from circulating macrophages. Both subclusters express immune regulatory genes, but genes related to cholesterol homeostasis are upregulated in Apoe+ TAMs compared to other cell types. Notably, lipid metabolism regulatory gene signatures are significantly enriched in TAMs from KRAS off tumors versus KRAS on tumors. Specifically, we observed upregulation of genes encoding scavenger receptors, lysosome enzymes, lipid binding proteins, galectins, and complement factors in TAMs from KRAS off tumors versus KRAS on tumors, resembling the characteristics of lipid-laden macrophages. Lipidomic profiling comparing tumor-educated macrophages (TEMs) exposed to conditional media from KRASi pre-treated KPC (p48-Cre, p53Lox/+, LSL-KRASG12D) PDAC cells (KRASi CM) and DMSO control (DMSO CM) revealed that the most significantly increased lipids were phospholipids, very long chain fatty acids, and ultra-long chain fatty acids. After examination of the expression of rate-limiting enzymes and key receptors involved in fatty acid synthesis, breakdown, and transportation, we found that Elovl1 and Abcd1 were significantly upregulated in TEMs exposed to KRASi CM compared to those exposed to DMSO control CM. Consistently, lipid content was higher in KRASi CM-treated TEMs compared to controls, as shown by BODIPY staining. Additionally, we observed an increased number of peroxisomes in KRASi CM-treated TEMs compared to control TEMs. These data collectively indicate that macrophages associated with KRASi-treated tumors exhibit aberrant accumulation of fatty acids. Citation Format: Pingping Hou, Ting-yu Chu, Yuemeng Huang, Daiyong Deng, Habeebunnisa Begum. Lipid-laden macrophages are associated with KRAS therapy resistance in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 1594.
43
Desai, Akshaykumar Narsinhbhai, Surajeet Mohanty, Venkatasailanathan Ramadesigan, and Suneet Singh. "Transient Characteristics of the Low-Temperature PEMFC: A Comparative Analysis Using a Physics-Based Model." ECS Meeting Abstracts MA2023-02, no. 37 (2023): 1708. http://dx.doi.org/10.1149/ma2023-02371708mtgabs.
Full textAbstract:
Low-temperature proton exchange membrane fuel cells (LT-PEMFCs) have experienced a considerable technological leap in the last few decades for transportation and stationary applications. Specifically, the precious metal loading in the catalyst layers (CLs) is notably decreased while enhancing the overall cell performance.1 However, the durability and cost remain major factors that affect the widespread commercialization of the LT-PEMFC. Though this can be achieved with further material development, some existing issues may be resolved by implementing effective design and control strategies. A good understanding of fuel cell water dynamics is required to improve durability and performance. Although some dynamic characteristics can be observed from the experiments, a physics-based model of the LT-PEMFC is necessary to study in-depth transient responses under various conditions like current profiles, operating temperatures, pressure, and humidification levels. Lately, the transient analysis of the fuel cell has gained more attention to elucidate the complex transport phenomena.2 Several transient models of the LT-PEMFC are reported to capture the two-phase behavior inside the cell. Usually, these models are 1D, 2D, or single channel 3D with assumptions like isothermal operation, vapor-equilibrated membrane, simplified reaction kinetics, and more.3–5 Hence, they do not provide spatio-temporal insights into the cell performance containing water dynamics with various flow configurations. The current study focuses on a transient physics-based model of the LT-PEMFC for dynamic analysis across its thickness and flow channels. The membrane used in LT-PEMFC requires humidification to enhance the ionic conductivity and function properly.6 This study considers Schroeder’s paradox for the membrane, which exhibits a different water uptake behavior in the presence of saturated water vapor and liquid water.7 The water uptake property is strongly dependent on the temperature. Therefore, we have developed a single polynomial expression for the membrane water uptake, including temperature and water activity dependency. Using the governing equations & empirical correlations from the numerical and experimental studies, we develop a comprehensive 3D, multiphase, non-isothermal, transient physics-based model of the LT-PEMFC that can closely approximate the liquid water transport under various operating conditions. It is a Multiphysics model that couples electrochemical reactions, porous media flow, transport of reactant species, liquid water transport, heat generation, charge transfer, and ionomer water transport. COMSOL Multiphysics is used to solve the model. It provides a spatio-temporal water distribution inside the membrane, CL, microporous layer, gas diffusion layer, and flow channels. Experiments are performed on 32 cm2 LT-PEMFC with the hybrid flow configuration at 75 °C and 80% RH to validate the physics-based model in the steady state condition. The validation study suggests that the present multiphase model estimates the LT-PEMFC performance with an acceptable RMS current density error of 15 mA/cm2. The simulations are operated in the Galvano-dynamic mode, and the corresponding LT-PEMFC response for the hybrid configuration is shown in Figure 1(a) at various operating pressures. Also, the preliminary results of the liquid water saturation under the channel and rib are incorporated in Figure 1(b). It shows that the water accumulation under the rib is more than the channel due to lower local temperature and weaker convection under the rib, promoting water vapor condensation. Further, the comparison between hybrid and parallel configurations is performed and illustrated in this presentation. Another objective is to study how quickly the liquid water saturation and membrane water content react upon changing the load cycle, RH, operating temperature, and flow configuration. This work is an important step toward understanding the impact of various flow configurations and operating conditions on the water dynamics and membrane water content inside the LT-PEMFC. The developed physics-based model would be extended further by considering the membrane deformation due to the shrinking-swelling under the humidification and thermal cycling, which is critical for the performance and degradation. References: A. Kongkanand and M. F. Mathias, J. Phys. Chem. Lett., 7, 1127–1137 (2016). P. A. García-Salaberri, D. G. Sánchez, P. Boillat, M. Vera, and K. A. Friedrich, J. Power Sources, 359, 634–655 (2017). A. Goshtasbi et al., J. Electrochem. Soc., 166, F3154–F3179 (2019). O. B. Rizvandi and S. Yesilyurt, Electrochim. Acta, 324, 134866 (2019). R. B. Ferreira, D. S. Falcão, V. B. Oliveira, and A. M. F. R. Pinto, Appl. Energy, 203, 474–495 (2017). A. Z. Weber and J. Newman, J. Electrochem. Soc., 151, A311–A325 (2004). L. Chen, Y. Chen, and W.-Q. Tao, Renew. Sustain. Energy Rev., 173, 113050 (2023). Figure 1
44
Salas Ventura, Santiago, Matthias Metten, Marius Tomberg, et al. "Transient Solid Oxide Cell Reactor Model Used in rSOC Mode-Switching Analysis and Power Split Control of an SOFC-Battery Hybrid." ECS Meeting Abstracts MA2023-01, no. 54 (2023): 278. http://dx.doi.org/10.1149/ma2023-0154278mtgabs.
Full textAbstract:
Defossilization of the global energy system requires a transition towards intermittent renewable energy sources and approaches that enable efficient conversion of primary energy sources into electrical energy. Due to their high efficiency in converting chemical into electrical energy and vice versa, solid oxide cell (SOC) systems provide solutions for both of these aspects. Within this contribution, two researched cases utilizing SOC's are presented, based on simulation studies and experiments. Characteristically, SOC reactors produce hydrogen from steam in solid oxide electrolysis (SOE) mode, or electricity from reformates in solid oxide fuel cell (SOFC) mode. An application of both modes as reversible solid oxide cell (rSOC) is to balance a renewable power supply with storage and power production, leading to high utilization of the same equipment. An application in SOFC mode is the maritime transportation powertrain. In both cases, transient operation is needed whenever mode transitions occur. In particular, switching between rSOC modes implies transitioning exothermal SOFC, endothermal, thermoneutral and exothermal SOE operation. Similarly, supplying the power demand of a maritime drivetrain in SOFC mode leads to various exothermic levels, as pertinent to part or full load operation. Operating strategies are needed to suppress potentially damaging thermal stresses during these transitions in the electrochemical SOC reactors. In order to identify such operating strategies, experiments have been carried out and a transient model has been developed for the analysis of rSOC mode-switching and SOFC drivetrain power supply, which are presented in this study. The 1D+1D SOC dynamic multi-reactor model includes the individual SOC reactors, piping and insulation, and is implemented in the in-house developed transient energy process system simulation framework TEMPEST [1,2]. The model couples the transient balances of mass and energy with electrochemistry, internal reforming kinetics, heat transfer, and flow distribution. As a result, temperature and voltage characteristics at cell, stack, and module levels are obtained to analyze for e.g. unwanted thermal stress. In the EU project SWITCH [3], experiments were performed at DLR with a Large Stack Module (LSM) from SolydEra (formerly SOLIDpower) to validate the model in transient 75 kW electrolysis mode, 25 kW fuel cell mode and mode-switching operation between electrolysis and polygeneration mode. The so called polygeneration mode refers to simultaneous generation of hydrogen and electricity at partial fuel utilization with natural gas, biogas or e-methane. Simulative studies of mode-switching procedures from SOE to SOFC-mode polygeneration show that drawing fuel cell current soon after reaching open circuit voltage and sufficiently in advance of the methane ramp completion leads to a reduced temperature decrease at the inlet of the cell without reaching oxygen to carbon ratios low enough to favor carbon deposition. In the EU project NAUTILUS [4], the mismatch between the transient response possibilities of SOFC systems and the power demand of a ship is addressed by connecting Li-ion batteries to the powertrain. Batteries respond to highly transient ship load demand changes, while the SOFC’s provide base part load to full load, according to a power split control strategy. A battery model developed and parametrized by the Chair for Electrochemical Energy Conversion and Storage Systems of RWTH Aachen University [5] was added to TEMPEST and validated using DLR experiments with a 40 kWh Li-ion battery. Simulation results of the SOFC-battery hybrid in Figure 1 show that a rule-based power split control strategy [6] ensures that the power demand of the ship is met at all times while the battery state of charge (SoC) remains within specified range, and the SOFC power is drawn at one of three fixed power levels for reduced thermal stress. An experimental campaign to test this and other control strategies with a 32 kW LSM from SolydEra and the 40 kWh battery is in progress at DLR. Acknowledgements Project SWITCH has received funding from the Fuel Cells and Hydrogen 2 Joint Undertaking (now Clean Hydrogen Partnership) under Grant Agreement No 875148. This Joint Undertaking receives support from the European Union’s Horizon 2020 Research and Innovation program, Hydrogen Europe and Hydrogen Europe Research. Project NAUTILUS has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 861647. References [1] S. Srikanth et al., Applied Energy 232 (2018) 473–488. DOI: 10.1016/j.apenergy.2018.09.186 [2] M. Tomberg et al., J. Electrochem. Soc. 2022, 169, 054530. DOI: 10.1149/1945-7111/ac7009 [3] SWITCH [Online, 16.12.2022] https://switch-fch.eu/ [4] NAUTILUS [Online, 16.12.2022] https://nautilus-project.eu/ [5] ISEA Framework [Online, 16.12.2022] https://git.rwth-aachen.de/isea/framework [6] Peng, H. et al. (2020). eTransportation, 4, 100057. DOI: 10.1016/j.etran.2020.100057 Figure 1. Transient simulation using an SOFC-battery power split algorithm and battery State of Charge (SoC). Figure 1
45
Wang, Xi, Kai Kang, Shiquan Wang, Jianhua Yao, and Xijing Zhang. "Focal cerebral ischemic tolerance and change in blood-brain barrier permeability after repetitive pure oxygen exposure preconditioning in a rodent model." Journal of Neurosurgery 125, no. 4 (2016): 943–52. http://dx.doi.org/10.3171/2015.7.jns142220.
Full textAbstract:
OBJECTIVE The goal of this study was to demonstrate that repetitive pure oxygen exposure preconditioning (O2PC) for 8 hours per day for 3 or 7 days, a practicable preconditioning for clinical use, is able to induce cerebral ischemic tolerance (IT) and further clarify the accompanying changes in the blood-brain barrier (BBB) that may be involved. METHODS A total of 68 adult male Sprague-Dawley rats and eight 1-day-old rat pups were used in this study. The adult rats were exposed to pure O2 (38 rats) 8 hours a day for 3 or 7 days or to room air (in an identical setup) for 8 hours a day for 7 days as controls (30 rats). Arterial O2 tension (PaO2) was measured in 6 rats exposed to O2 and 3 controls. Focal cerebral ischemia was elicited by middle cerebral artery occlusion (MCAO) in 37 rats, of which 21 had been exposed to pure O2 for 3 or 7 days and 16 to room air for 7 days as controls. Neurological behavior was scored with the Garcia score in 15 MCAO rats, of which 10 had been exposed to pure O2 for 3 or 7 days and 5 to room air for 7 days as controls, and cerebral infarct volumes were assessed with TTC (2,3,5-triphenyltetrazolium chloride) staining in 10 rats (5 from each group) after 7 days of exposure. Formamide-extraction method was used to detect leakage of Evans blue (EB) dye in 7 rats exposed to pure O2 for 7 days and 7 exposed to room air for 7 days. Fluorescence microscopy was used to analyze the leaked EB in the nonischemic areas of 4 rats exposed to pure O2 for 7 days and 4 exposed to room air for 7 days before MCAO and the brain of the rats that had not been subjected to MCAO. Astrocyte changes associated with O2PC were evaluated by means of fluorescence microscopy and electron microscopy in 14 rats that were exposed to the same O2 or control conditions as the MCAO rats but without MCAO. Astrocytes were also obtained from 8 rat pups and cultured; levels of AQP4 and VEGF were detected by Western blot and ELISA in cells with and without O2 treatment. RESULTS A significant increase in PaO2 was seen after O2PC. The neurological score was significantly increased in the O2PC groups (10.6 ± 0.6 in the 3-day O2PC group, p < 0.05; 12 ± 0.84 in the 7-day O2PC group, p < 0.05) compared with the control group (7 ± 0.55). The ratio of cerebral infarct volume to contralateral cerebral hemisphere volume was significantly lower in the O2PC group than in the control group (0.204 ± 0.03 vs 0.48 ± 0.05, p < 0.05). The amount of leaked EB in the ischemic cerebral hemisphere was also lower in the O2-treated rats than in controls (7.53 ± 1.4 vs 11.79 ± 3.3 μg EB/g brain weight, p < 0.05). However, fluorescence microscopy showed significantly greater BBB permeability in the nonischemic areas in the O2PC group than in controls (p < 0.05). More red fluorescence could be observed in the nonischemic areas in both the ipsilateral and contralateral sides of the ischemic brain in the O2PC animals than in the nonischemic areas in the corresponding sides of the controls. Further investigation of the effect of the O2PC itself on the BBB of rats that were not subjected to MCAO showed that there was no EB leakage in the brain parenchyma in the rats exposed to room air, but some red fluorescence patches were noticed in the normal brain from the rats in the O2PC group. Astrocytes, including those from areas around the BBB, were activated in the O2PC group. Levels of both aquaporin 4 (AQP4) and vascular endothelial growth factor (VEGF) were significantly increased in cultured astrocytes after O2PC. CONCLUSIONS These findings suggest that O2PC is able to induce IT, which makes it a strong candidate for clinical use. Moreover, O2PC can also promote BBB opening, which may contribute to the induction of IT as well as representing a possible strategy for promoting drug transportation into the CNS. Activated astrocytes are likely to be involved in these processes through astrocyte-derived factors, such as AQP4 and VEGF.
46
Mazrouei Sebdani, Mohsen, Erik Kjeang, and Heather Baroody. "Modeling and Simulation of the Mechanical Properties of Reinforced Fuel Cell Membranes." ECS Meeting Abstracts MA2022-01, no. 41 (2022): 2468. http://dx.doi.org/10.1149/ma2022-01412468mtgabs.
Full textAbstract:
Polymer electrolyte fuel cells (PEFCs) have gained popularity over internal combustion engines due to their zero CO2 emission, low working temperature, and high efficiency. However, transportation markets generally require high durability and reliability, which remains a significant challenge for PEFC developers. For instance, the thin, ion-conducting membranes used in PEFCs must be able to withstand both chemical and mechanical stresses during dynamic operation. Reinforced membranes even still there are durability challenges that remain even though it is more robust. These membranes have limited mechanical strength, and micro-cracks may allow hydrogen permeation and cause ultimate fuel cell failure. Dynamic stresses caused by temperature and humidity cycles are causing micro-cracks to form and propagate. Because the membrane is constrained by the other parts of the membrane-electrode assembly (MEA), any change in temperature and humidity can create swelling strain and thermal strain in the membrane, resulting in residual stress [1]. The first step in understanding this damaging phenomenon is to simulate the membrane's visco-elastic and visco-plastic behavior while taking temperature, humidity, and strain rate into account. The objective of the present work is to develop such a constitutive mechanical model for mechanically reinforced membranes, which are commonly used in modern PEFCs. Khorasany et al. [2] developed a fatigue lifetime model based on the elastic-plastic constitutive method and Smith-Watson-Topper (SWT) fatigue equilibrium for conventional, non-reinforced fuel cell membranes. In the present work, for strains below the yield point, the linear elasticity by Hooke's law has been considered and the visco-elastic and visco-plastic behaviors of the membrane have been neglected, but for every temperature and humidity, the related Young’s modulus and Poisson’s ratio have been obtained from prior experiments, and for plastic yield response, the Von Mises yield criterion has been selected. Khattra et al. [3] used the G’Sell-Jonas theory for the constitutive model of a non-reinforced membrane, which can only be employed for tensile stresses, while in this study, a generalized G’Sell-Jonas approach; equation 1, has been developed for the reinforced membrane that can also be used for compressive stresses that are common during in-situ fuel cell conditions. This phenomenological theory accounts for the effects of temperature, humidity, and strain rate on membrane mechanical properties and, when combined with thermal and swelling strains, provides a comprehensive model of membrane behavior for both ex-situ and in-situ conditions. For the reinforced membrane, tensile stress-strain tests in two principal in-plane directions have been done that showed its isotropic behavior and, therefore, provide input data for the parameters of the proposed generalized G’Sell-Jonas model. σ(ε,T,H)generalized G'Sell-Jonas=step(ε)K(T,H)(1-e-w(H)abs(ε))eh(H)ε^2 (1) step(ε)=+1 ε≥0, -1 ε<0 In the above equations, K, w, and h are empirical parameters dependent on temperature (T) and humidity (H), and ε is strain. Elastic modeling based on Von-Mises has been studied for constitutive models with stresses below 1 MPa, while isotropic work hardening based on the generalized G'Sell-Jonas theory has been considered for higher stresses in order to follow plastic behavior. In elastic mode, the membrane's Young’s modulus is calculated using a function of humidity and temperature derived from tensile tests. Tensile tests under four environmental conditions and two strain rates in two principal in-plane directions, as well as fatigue tests for extracting S-N curves for this membrane, have been obtained using dynamic mechanical analysis (DMA). Based on Figure 1, the mechanical strength of this isotropic reinforced membrane decreases with increasing temperature and humidity, but the effect of temperature is greater. Because of the viscoelastic nature of the membrane, by increasing the strain rate, the membrane stiffness has been increased too. In the fatigue tests done in DMA, the force track is 150% (= ×100%), R-value = , and frequency is 10 Hz. FEM modeling based on G’Sell-Jonas’s theory shows a strong agreement with the experiments that has been illustrated in Figure 1. The fatigue lifetime distribution based on generalized G’Sell-Jonas’s theory and SWT parameters extracted from Khorasany’s paper [2] have been simulated that reveals when the maximum stress in fatigue cycles is more than 17-18 MPa, a huge drop in fatigue lifetime is observed. Acknowledgments Funding for this research has been provided by AVL Fuel Cell Canada and Mitacs. References Alavijeh, A.S., et al., Effect of hygral swelling and shrinkage on mechanical durability of fuel cell membranes. Journal of Power Sources, 2019. 427: p. 207-214. Khorasany, R.M., et al., Mechanical degradation of fuel cell membranes under fatigue fracture tests. Journal of Power Sources, 2015. 274: p. 1208-1216. Khattra, N.S., et al., Residual fatigue life modeling of fuel cell membranes. Journal of Power Sources, 2020. 477: p. 228714. Figure 1
47
Pina, Eduardo Antonio, Berend van Veldhuizen, Francois Marechal, and Jan Van herle. "A Comparative Techno-Economic Assessment of Alternative Fuels in SOFC Systems for Cruise Ships." ECS Meeting Abstracts MA2023-01, no. 54 (2023): 377. http://dx.doi.org/10.1149/ma2023-0154377mtgabs.
Full textAbstract:
Maritime transportation accounts for about 2.9% of global greenhouse gas (GHG) emissions, according to the fourth International Maritime Organization (IMO) GHG study. In the period from 2012 to 2018, shipping emissions have increased by almost 10%. Facing growing political and societal pressure, the IMO has established GHG emissions reduction targets consistent with the Paris Agreement temperature goals, aiming to reduce the total annual GHG emissions by at least 50% by 2050 compared to 2008 levels. In this context, alternative fuels and innovative technologies are needed to allow the maritime industry to comply with forthcoming regulations, as well as to fulfil decarbonisation targets within the European and the global markets. The shipping industry has already started to transition from traditional marine fuels, such as heavy fuel oil and marine diesel oil, to Liquified Natural Gas (LNG) in Internal Combustion Engines (ICEs). However, this can only be regarded as a bridging solution. In recent years, three major research lines can be identified: First, battery-electric propulsion, exploring the potential benefits of shaving peak thruster power and improving the energy efficiency and range of ships. Second, Solid Oxide Fuel Cells (SOFCs), which have a marked advantage of fuel flexibility and offer higher electrical efficiencies than ICEs and other fuel cell technologies, as well as higher-grade waste heat. Third, alternative marine fuels, such as synthetic hydrocarbons, biofuels, ammonia and hydrogen, as a way to significantly reduce or even phase out GHG emissions and other air pollutants. The present study bridges the aforementioned research lines by proposing a novel integrated marine energy system composed of an SOFC-battery hybrid genset that consumes LNG. The objective is to perform a techno-economic assessment of the hybrid genset for LNG and four identified potential alternative fuels (i.e. methanol, diesel, ammonia, and hydrogen). The best solutions will be identified and analysed, and a decision-making framework will be proposed. The comparison will identify the critical conditions for the genset processes being competitive to the state-of-the-art engine-based energy system. The analysis is divided into two main parts. The first part is dedicated to the SOFC module, which is composed of the SOFC stack and the balance of plant equipment. The BOP includes fuel storage, reformer, combustor, heat recovery system, pumps, and blowers. Previous work by the authors has developed the thermodynamic analysis of the genset systems that provide the starting point for the present analysis. The flow-sheet software Cycle Tempo was used in those analyses. The SOFC module has a nominal power production of 100 kWe, which is achieved by combining several stacks of 10 kWe, and produces hot water at 90 °C and saturated steam at 180 °C from waste heat recovery. In the second part, the SOFC-battery hybrid genset is achieved by combining several 100 kWe SOFC modules into power blocks and hybridizing them with batteries. The systems are designed to cover all the electricity and heat demands of the vessel, including propulsion and hotel load. A representative electrical demand of a large cruise ship is selected in the range of 30-60 MWe, of which about 80% is required for propulsion while the remaining is needed for the hotel. Among the main criteria for comparing the hybrid genset running on different fuels are the total annual cost, composed of the annual investment cost and annual operation cost, and the Levelized Costs of Energy, Electricity and Exergy. The latter is especially important because of the joint production of electricity and heat (saturated steam at 180 °C and hot water at 90 °C) that takes place in the genset. The investment cost was estimated using data collected from the literature or provided by manufacturers. The necessary replacement of SOFC stacks is taken into account, given the stack lifetime. Weight and volume requirements associated with the use of different fuels are assessed. The annual operation cost consists of fuel consumption and maintenance costs, as well as the application of an environmental tax for CO2 emissions. Different scenarios are proposed to evaluate the impacts of improvements in key parameters on the overall feasibility of the systems. The robustness of the results is evaluated by sensitivity and uncertainty analyses of the key technical and economic parameters used in the model, including, among other parameters, the fuel purchase price, SOFC and battery investment costs, stack lifetime, and interest rate. This research provides a systematic comparison of the techno-economic feasibility of five alternative fuels for cruise ships. The results will aid decision-makers, including shipyards and policymakers, in designing new energy systems with low emissions for maritime applications.
48
Meng, Zhaoxin, Yixue Liu, Junjie Di, Qing He, Yi Shen, and Dongmei Du. "Multi‐factor Analysis of Capacity Allocation Optimization for Novel Wind‐Hydrogen Coupled Power Generation Systems." Energy Technology, March 19, 2024. http://dx.doi.org/10.1002/ente.202301095.
Full textAbstract:
Wind power generation has the problem of wind resource waste. Wind‐hydrogen coupled can enhance wind power's utilization and revenue. Currently, there is no discussion of the impact of multiple factors on the system configuration. In this study, take the annual profit of the wind‐hydrogen coupled power generation systems (WHCPGS) as the objective function, and construct the multi‐factor capacity configuration model. Using particle swarm optimization (PSO) to solve the model, and analyzes the impact of multi‐factors on the system's annual profit and revenue mode. The results show that with 30 wind turbines, the coupled system annual profit increases by 43% compared to the alone system. The higher investment does not make the system more rewarding. The configuration results are the same for investments of 0.8 billion ¥ and 1 billion ¥. The price at 0.20 ¥ kW−1 h−1, the coupled system has the optimal annual profit. Fuel cells’ (FCs) electricity price and hydrogen transportation distance are crucial factors influencing the mode of the system profit. This study has specific reference significance for the practical application of capacity configuration of the system.
49
Garg, Akhil, C. Ruhatiya, Xujian Cui, Xiongbin Peng, Yogesh Bhalerao, and Liang Gao. "A Novel Approach for Enhancing Thermal Performance of Battery Modules Based on Finite Element Modeling and Predictive Modeling Mechanism." Journal of Electrochemical Energy Conversion and Storage 17, no. 2 (2019). http://dx.doi.org/10.1115/1.4045194.
Full textAbstract:
Abstract Electric vehicles (EVs) are estimated as the most sustainable solutions for future transportation requirements. However, there are various problems related to the battery pack module and one such problem is invariable high-temperature differences across the battery pack module due to the discharging and charging of batteries under operating conditions of EVs. High-temperature differences across the battery module contribute to the degradation of maximum charge storage and capacity of Li-ion batteries which ultimately affects the performance of EVs. To address this problem, a finite element modeling (FEM) based automated neural network search (ANS) approach is proposed. The research methodology constitutes of four stages: design of air-cooled battery pack module, setup of the FEM constraints and thermal equations, formulating the predictive model on generated data using ANS, and lastly performing multi-objective response optimization of the best fit predictive model to formulate optimum design constraints for the air-cooled battery module. For efficient thermal management of the battery module, an empirical model is formulated using the mentioned methodology for minimizing the maximum temperature differences, standard deviation of temperature across the battery pack module, and battery pack volume. The results obtained are as follows: (1) the battery pack module volume is reduced from 0.003279 m3 to 0.002321 m3 by 29.21%, (2) the maximum temperature differences across the eight cells of battery pack module declines from 6.81 K to 4.38 K by 35.66%, and (3) the standard deviation of temperature across battery pack decreases from 4.38 K to 0.93 K by 78.69%. Thus, the predictive empirical model enhances the thermal management and safety factor of battery module.
50
Chatterjee, Debasmita, Aditya Prasad Panda, A. R. Daya Manasi, and Anindya S. Ghosh. "P-type ATPase zinc transporter Rv3270 of Mycobacterium tuberculosis enhances multi-drug efflux activity." Microbiology 170, no. 2 (2024). http://dx.doi.org/10.1099/mic.0.001441.
Full textAbstract:
Graphical abstract: The probable model depicting antibiotic export by Rv3270 (a) Antibiotics are reported to enter the cells through porin channels such as Msp family porins .(b) Zn2+ (green dots) imported into the cells through probable Zn2+ importers such as ZIP transporters. (c) Zinc inside the cells may influence the efflux of antibiotics by a co-transportation process through Rv3270 triggered by ATP hydrolysis. (d) Rv3270 possibly captures beta-lactams and extrudes them out of the cells via hypothetical linking proteins (outer membrane efflux adaptor proteins) and porins (Msp family) like AcrAB-TolC and Rv0194. This maintains a lower concentration of the antibiotic inside the cell, reducing its chances of exerting inhibitory effects on cell wall synthesis.