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Kumar Seth, Aakash, e Mukhtiar Singh. "Plant integrated proportional integrating based control design for electric vehicle charger". Computers and Electrical Engineering 105 (gennaio 2023): 108522. http://dx.doi.org/10.1016/j.compeleceng.2022.108522.
Testo completo
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Gokul, A. P., Arun Palanimuthu e P. B. Shabitha. "Studies on Integrated Nutrient Management on Yield and Quality Characters of Elephant Foot Yam (Amorphophallus paeonifolius (Dennst.) Nicolsan) cv. Gajendra". International Journal of Plant & Soil Science 35, n. 21 (16 ottobre 2023): 177–83. http://dx.doi.org/10.9734/ijpss/2023/v35i213960.
Testo completoAbstract (sommario):
The investigation was carried out to study the intergrated nutrient management practices on yield and quality characters of Elephant foot yam (Amorphophallus paeonifolius (Dennst.) Nicolsan) cv. Gajendra. The field experiment was laid out in randomized block design with thirteen treatments with three replications and conducted at farmer’s field at Thirukkanur village, Villianur, Puducherry during the year 2020 with spacing 60 x 60 cm. Elephant foot yams corms were cut into 800 g for planting, after cutting corms were dipped in cow dung slurry and placed for drying. The treatments comprised of three levels of recommended dose of fertilizers (RDF - 80:40:100 Kg NPK ha-1) viz., 75%, 100% and 150% along with organic inputs viz., FYM (20 t ha-1), Vermicompost (5 t ha-1) and (CBF 5 Kg ha-1), organic manures of different combinations were applied as basal; where as recommended dose of fertilizer were also applied combined with organic manures. The observations were recorded at 190 days after planting. The results recorded maximum values for yield parameters viz., Culm girth (14.60 cm), Corm circumference (46.86 cm), Single Corm weight (48.21 Kg) plant-1, Yield plant-1 (2.42 Kg), Yield per plot (60.76 Kg), Total yield (40.15t ha-1) whereas quality parameters such as Moisture content (79.64 %), Starch content (18.02 %), Crude protein(6.11 %), Calciumoxalate (12.18 mg g-1), Total sugar content (2.62 mg g-1) and β carotene (0.19µg g-1). From the experiment, it was concluded that the integrated nutrient management viz., combination of vermicompost with 100 per cent RDF along with consortium biofertilizer were identified as the best treatment to increase quality and yield.
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Huang, Jianfeng, Jianlong Zhang e Chengliang Yin. "Comparative study of motor speed synchronization control for an integrated motor–transmission powertrain system". Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 234, n. 4 (13 luglio 2019): 1137–52. http://dx.doi.org/10.1177/0954407019862894.
Testo completoAbstract (sommario):
This paper compares several kinds of methods for motor speed synchronization control, which plays an important role in gear shifting of emerging clutchless automated manual transmissions for battery electric vehicles and other powertrain systems for hybrid electric vehicles. Specifically, four controllers, namely, proportional-integral control, disturbance observer–based proportional control, integral sliding mode–based proportional control, and disturbance observer–based act-and-wait control, are compared in transient responses regarding settling time, overshoot, and steady-state error. Each is formulated by combining one nominal controller for speed tracking and another for disturbance compensation. For disturbance observer–based proportional control, model-based determination of the feedback gain and disturbance observer gain is discussed. Simulations and experiments are carried out to study effects of different controller parameter settings and evaluate performances of different methods under different operation conditions with disturbances and uncertainties like plant parameter drift, communication time delay, unknown load torques, and so on. Based on the results, it is advised that disturbance observer–based proportional control with the reference signal set as the nominal speed trajectory be used in practice, since it comes with merits of few controller parameters to be determined as well as robust, consistent, and satisfactory performances.
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Gül, Ozan, e Nusret Tan. "Application of fractional-order voltage controller in building-integrated photovoltaic and wind turbine system". Measurement and Control 52, n. 7-8 (17 luglio 2019): 1145–58. http://dx.doi.org/10.1177/0020294019858213.
Testo completoAbstract (sommario):
The share of electricity generation based on clean, inexhaustible and continuous energy sources, such as solar and wind, in total energy production, is rising day by day due to its significant advantages such as having the less negative impact on global climate and environmental pollution and not requiring fuel for energy production. It is reported that commercial and residential buildings correspond to about 20.1% of the world energy consumption, so it is necessary to provide energy needs of buildings with hybrid renewable energy systems. When using non-continuous energy sources such as solar panel and wind turbines, it is important to ensure ensuring a stable and quality power flow to the building while the power demands of building show very sharp variability. This work presents a voltage control system using fractional-order operators in the smart residential building-integrated hybrid renewable power plant (solar + wind). In this research article, fractional-order proportional–integral/proportional–integral–derivative controllers are proposed on a synchronous frame for a pulse-width modulation based three-phase voltage source inverter in residential building-integrated solar panel and wind turbines system (building-integrated photovoltaic/wind turbine system) in order to improve the quality of injected voltage to building. When comparing the effect of closed-loop voltage control system with integer order controllers (proportional–integral and proportional–integral–derivative) on the power quality at the building distribution by analyzing the simulation results for proposed case study, use of fractional-order voltage controllers for nonlinear system such as building integrated with hybrid renewable sources is more suitable than using integer order voltage controllers.
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Sadras, Victor O. "A quantitative top-down view of interactions between stresses: theory and analysis of nitrogen - water co-limitation in Mediterranean agro-ecosystems". Australian Journal of Agricultural Research 56, n. 11 (2005): 1151. http://dx.doi.org/10.1071/ar05073.
Testo completoAbstract (sommario):
The multiple factors constraining the growth, reproduction, and survival of diverse organisms are often non-additive. Research of interacting factors generally involves conceptual models that are specific for target organism, type of stress, and process. As a complement to this reductionist, bottom-up view, in this review I discuss a quantitative top-down approach to interacting stresses based on co-limitation theory. Firstly, co-limitation theory is revised. Co-limitation is operationally identified when the output response of a biological system (e.g. plant or population growth) to two or more inputs is greater than its response to each factor in isolation. The hypothesis of Bloom, Chapin, and Mooney, that plant growth is maximised when it is equally limited by all resources, is reworded in terms of co-limitation and formulated in quantitative terms, i.e. for a given intensity of aggregate stress, plant growth is proportional to degree of resource co-limitation. Emphasis is placed on the problems associated with the quantification of co-limitation. It is proposed that seasonal indices of nitrogen and water stress calculated with crop simulation models can be integrated in indices accounting for the aggregated intensity of water and nitrogen stress (SWN), the degree of water and nitrogen co-limitation (CWN), and the integrated effect of stress and co-limitation (SCWN = CWN/SWN). The expectation is that plant growth and yield should be an inverse function of stress intensity and a direct function of co-limitation, thus proportional to SCWN. Secondly, the constraints imposed by water and nitrogen availability on yield and water use efficiency of wheat crops are highlighted in case studies of low-input farming systems of south-eastern Australia. Thirdly, the concept of co-limitation is applied to the analysis of (i) grain yield responses to water–nitrogen interactions, and (ii) trade-offs between nitrogen- and water-use efficiency. In agreement with theoretical expectations, measured grain yield is found to be proportional to modelled SCWN. Productivity gains associated with intensification of cropping practices are interpreted in terms of a trade-off, whereby water-use efficiency is improved at the expense of nitrogen-use efficiency, thus leading to a higher degree of resource co-limitation.
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Chatterjee, Aditi, Kanungobarada Mohanty, Vinaya Sagar Kommukuri e Kishor Thakre. "Model predictive current controller for performance enhancement of grid-integrated single-phase photovoltaic distributed generation plants". Transactions of the Institute of Measurement and Control 40, n. 3 (12 settembre 2016): 762–75. http://dx.doi.org/10.1177/0142331216665686.
Testo completoAbstract (sommario):
Acknowledgement of renewable sources of energy as substitute energy sources for power production has expanded the number of distributed generation plants being incorporated into the conventional power distribution system. The single-phase voltage source inverter allying the photovoltaic plant with the grid has to address various issues identified with the quality of current injected into the grid, output power factor and power exchange between the plant and the grid. This paper concentrates on the investigation, design and implementation of a digital predictive current control technique known as the model predictive current controller for the control of single-phase photovoltaic distributed generation plants. The performance of the controller is evaluated under varied operating conditions. The proposed current controller is compared with the conventional proportional–integral controller in terms of its design methodology, steady state and dynamic response. The simulation and experimental results validates the effectiveness of the proposed model predictive current controller.
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Piano, Jeferson Tiago, Jonas Francisco Egewarth, Jucenei Fernando Frandoloso, Eloisa Mattei, ,. Paulo Sérgio Rabello de Oliveira, Carlos Augusto Rocha de Moraes Rego e Juan López de Herrera. "Decomposition and nutrients cycling of residual biomass from integrated crop-livestock system". Australian Journal of Crop Science, n. 13(05) 2019 (20 maggio 2019): 739–45. http://dx.doi.org/10.21475/ajcs.19.13.05.p1488.
Testo completoAbstract (sommario):
The objective was to evaluate the decomposition and nutrient release of biomass from maintenance of fallow or oat crop (IPR 126), managed in integrated crop-livestock, during the soybean crop cycle (85 days) in no tillage system in two years (2014 and 2015). The design was a randomized complete block in a subdivided plot scheme, with the parcel consisting of four plots (four straws, from fallow or oat cultivation) and the subplots (evaluation periods 0, 10, 35, 60 and 85 DAS) with the evaluation times throughout the crop cultivation soybean. The amount of biomass and the content of C, N, P, K, Ca, Mg and Zn were calculated. The amount of biomass and nutrients presents a similar pattern of decrease in their values; however, the climatic conditions and the C/N ratio play an important role in the decomposition and mineralization of nutrients. The mineralized amount of N, K, P, Ca, Mg and Zn is directly proportional to their initial content in the biomass, and K nutrient is quickly released from crop residues. Most of the nutrients studied were released during the soybean crop development cycle, favoring its development; this can provide a reduction of external inputs in the property.
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Bakhtiar, Toni, Ihza Rizkia Fitri, Farida Hanum e Ali Kusnanto. "Mathematical Model of Pest Control Using Different Release Rates of Sterile Insects and Natural Enemies". Mathematics 10, n. 6 (10 marzo 2022): 883. http://dx.doi.org/10.3390/math10060883.
Testo completoAbstract (sommario):
In the framework of integrated pest management, biological control through the use of living organisms plays important roles in suppressing pest populations. In this paper, the complex interaction between plants and pest insects is examined under the intervention of natural enemies releases coupled with sterile insects technique. A set of nonlinear ordinary differential equations is developed in terms of optimal control model considering characteristics of populations involved. Optimal control measures are sought in such a way they minimize the pest density simultaneously with the control efforts. Three different strategies relating to the release rate of sterile insects and predators as natural enemies, namely, constant, proportional, and saturating proportional release rates, are examined for the attainability of control objective. The necessary optimality conditions of the control problem are derived by using Pontryagin maximum principle, and the forward–backward sweep method is then implemented to numerically calculate the optimal solution. It is shown that, in an environment consisting of rice plants and brown planthoppers as pests, the releases of sterile planthoppers and ladybeetles as natural enemies can deteriorate the pest density and thus increase the plant biomass. The release of sterile insects with proportional rate and the release of natural enemies with constant rate are found to be the most cost-effective strategy in controlling pest insects. This strategy successfully decreases the pest population about 35 percent, and thus increases the plant density by 13 percent during control implementation.
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Buffo, Giulio, Domenico Ferrero, Massimo Santarelli e Andrea Lanzini. "Reversible Solid Oxide Cell (ReSOC) as flexible polygeneration plant integrated with CO2 capture and reuse". E3S Web of Conferences 113 (2019): 02009. http://dx.doi.org/10.1051/e3sconf/201911302009.
Testo completoAbstract (sommario):
This work presents the concept of a Reversible Solid Oxide Cell (ReSOC) system localized in an urban residential district. The system is operated as a polygeneration plant that acts as interface between the electricity grid and the local micro-grid of the district. The ReSOC plant produces hydrogen via electrolysis during periods of low electricity demand (i.e., low-priced electricity). Hydrogen is used for multiple city needs: public mobility (H2 bus fleet), electricity production delivered to the micro-grid during peak-demand hours, and heat (accumulated in a storage) provided to the local district heating (DH) network. An additional option analyzed is the use of part of the H2 to produce DME using CO2 captured from biogas obtained from municipal solid wastes. The DME is used for fueling a fleet of trucks for the garbage collection in the residential district. A traditional CO2 removal process based on liquid MEA thermally integrated with the ReSOC system is studied. A time-resolved model interfaces the steady-state operating points with the thermal storage and the loads (electrical, H2 buses, DME trucks, heat), implementing constraints of thermal and H2 self-sufficiency on the system. Neglecting the DME option, the average daily roundtrip electric efficiency is about 38%, while the annual efficiency, which includes H2 mobility and thermal energy to DH, reaches 68%. When the DME option is considered, the thermal demand for CO2 removal and conversion process reduces the heat availability for DH, while the need for additional H2 for DME synthesis increases the electricity consumption for water electrolysis: both these phenomena imply a reduction of system efficiency (-9%) proportional to DME demand.
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McMurtry, Mark, e Douglas Sanders. "PERFORMANCE OF AN INTEGRATED AQUACULTURE~ OLERICULTURE SYSTEM AS INFLUENCED BY COMPONENT RATIO". HortScience 25, n. 9 (settembre 1990): 1151F—1151. http://dx.doi.org/10.21273/hortsci.25.9.1151.
Testo completoAbstract (sommario):
Fish and vegetable production were linked in a recirculating water system. Hybrid tilapia were grown in tanks and fed a commercial feed. Tomato or cucumber were grown in sand biofilters associated with each tank. Four tank to biofilter volume ratios, ranging from 1:0.67 to 1:2.25, were studied by varying the biofilter size. Plant populations were directly proportional to biofilter volume and surface irrigated 8 times daily with aquacultural `waste' water, Biofilter drainage returned to the fish tanks by gravity. Each system received identical nutrient inputs and plants received equal water. Biological filtration, aeration, and mineral assimilation by plants maintained water quality under rapid fish growth rates. Dissolved oxygen levels, make-up water, fish biomass increase and growth rates increased with biofilter volume. Total fruit yield increased but yield per plant decreased with increasing biofilter volume. Caloric content of the increase in fish biomass per liter of total water decreased white that of tomato increased with increasing biofilter volume. Calories in the combined yields per liter of water used did not differ by treatment. Total protein production per liter of water used decreased with increasing biofilter volume. Both caloric value and protein production in the combined outputs increased with biofilter volume irrespective of water consumption. Annualized economic value from the combined fish and `Laura' tomato production per composite unit area ranged from $98 to $124 m-2 with decreasing tank to biofilter ratio.
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McMurtry, Mark, e Douglas Sanders. "PERFORMANCE OF AN INTEGRATED AQUACULTURE~ OLERICULTURE SYSTEM AS INFLUENCED BY COMPONENT RATIO". HortScience 25, n. 9 (settembre 1990): 1151f—1151. http://dx.doi.org/10.21273/hortsci.25.9.1151f.
Testo completoAbstract (sommario):
Fish and vegetable production were linked in a recirculating water system. Hybrid tilapia were grown in tanks and fed a commercial feed. Tomato or cucumber were grown in sand biofilters associated with each tank. Four tank to biofilter volume ratios, ranging from 1:0.67 to 1:2.25, were studied by varying the biofilter size. Plant populations were directly proportional to biofilter volume and surface irrigated 8 times daily with aquacultural `waste' water, Biofilter drainage returned to the fish tanks by gravity. Each system received identical nutrient inputs and plants received equal water. Biological filtration, aeration, and mineral assimilation by plants maintained water quality under rapid fish growth rates. Dissolved oxygen levels, make-up water, fish biomass increase and growth rates increased with biofilter volume. Total fruit yield increased but yield per plant decreased with increasing biofilter volume. Caloric content of the increase in fish biomass per liter of total water decreased white that of tomato increased with increasing biofilter volume. Calories in the combined yields per liter of water used did not differ by treatment. Total protein production per liter of water used decreased with increasing biofilter volume. Both caloric value and protein production in the combined outputs increased with biofilter volume irrespective of water consumption. Annualized economic value from the combined fish and `Laura' tomato production per composite unit area ranged from $98 to $124 m-2 with decreasing tank to biofilter ratio.
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Jain, Sanjiv Kumar, Sandeep Bhongade, Shweta Agrawal, Abolfazl Mehbodniya, Bhisham Sharma, Subrata Chowdhury e Julian L. Webber. "Interrelated Solar and Thermal Plant Autonomous Generation Control Utilizing Metaheuristic Optimization". Energies 16, n. 8 (10 aprile 2023): 3355. http://dx.doi.org/10.3390/en16083355.
Testo completoAbstract (sommario):
In this study, the load frequency control of a two-area thermal generation system based on renewable energy sources is considered. When solar generation is used in one of the control areas, the system becomes nonlinear and complicated. Zero deviations in the frequencies and the flow of power through the tie lines are achieved by considering load disturbances. A novel grey wolf optimizer, which is a metaheuristic algorithm motivated by grey wolves is utilized for tuning the controller gains. The proportional, integral, and derivative gains values are optimized for the two-area Solar integrated Thermal Plant (STP). As the load connected to the system varies continuously with time, random load variation is also applied to observe the effectiveness of the proposed optimization method. Sensitivity analyses have also been adopted with the deviation in the time constants of different systems. Inertia constant variations of both areas are considered from −25% to +25%, with or without STP. The proposed algorithm shows good dynamic performance as shown from the simulation results in terms of settling time, overshoot values, and undershoot values. The power in the tie line achieves zero deviation quite rapidly in solar-based cases compared to those without STP.
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Tao, Guoliang, Ce Shang e Deyuan Meng. "Adaptive Robust Posture Control of a 3-RPS Pneumatic Parallel Platform with Unknown Deadzone". Mathematical Problems in Engineering 2016 (2016): 1–16. http://dx.doi.org/10.1155/2016/2034923.
Testo completoAbstract (sommario):
An adaptive robust controller integrated with online deadzone estimation is proposed. This controller provides trajectory tracking control for pneumatic parallel mechanisms. Due to the air compressibility and nonlinear characteristics of the pneumatic system, unknown parameters in the model are selected to build online estimation matrices with the robust parts considered in the design. As each proportional valve has specific values of deadzone boundary points, the deadzone parts are integrated into the online estimator, and an inverse deadzone compensator is used to overcome nonlinear limitations. The effectiveness of the method was verified by simulation and experiment, and theoretical stability was demonstrated using the Lyapunov method. Experiments in an actual plant with the proposed controller indicated that the performance of the pneumatic platform can be as good as that of ideal deadzone inverse compensation. The deadzone estimated parameters converged to the real values quickly. Additionally, this algorithm was effective under a compound reference input trajectory; thus, the controller is expected to perform well in actual working situations.
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Saha, Arindita, Puja Dash, Naladi Ram Babu, Tirumalasetty Chiranjeevi, Mudadla Dhananjaya e Łukasz Knypiński. "Dynamic Stability Evaluation of an Integrated Biodiesel-Geothermal Power Plant-Based Power System with Spotted Hyena Optimized Cascade Controller". Sustainability 14, n. 22 (10 novembre 2022): 14842. http://dx.doi.org/10.3390/su142214842.
Testo completoAbstract (sommario):
The perception of automatic generation control (AGC) has a massive part in delivering eminence power in an interrelated structure. To acquire eminence power by monitoring the fluctuations of frequency and tie-link power, an appropriate controller strategy is essential. This work explores AGC learning under the traditional situation. In this study, we employ a cascade controller with proportional amalgamation with a tilt-integral-derivative with a filter (TIDN) and fractional order integral-derivative (FOID), named TIDN-FOID. In order to acquire the controller’s attributes, a meta-heuristic optimization algorithm spotted hyena optimizer (SHO) is employed. Several investigations express the excellency of the TIDN-FOID controller over other controllers from outlook regarding the lessened level of peak_overshoot, peak_undershoot, and settling_time for the considered structure. The structure comprises thermal, biodiesel units in area 1, thermal, and geothermal units in area-2, and hydrothermal units in area-3. Both biodiesel and GPP have a better effect on system dynamics even in the presence of time delay. Action in the redox flow battery is also examined, providing a noteworthy outcome. Eigenvalue assessment is carried out to comment on the stability of the system. TIDN-FOID parameter values at nominal conditions are appropriate for a higher disturbance value without the need for optimization.
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Piao, Minnan, Mingwei Sun, Jian Huang, Zenghui Wang e Zengqiang Chen. "Partial integrated guidance and control design for supersonic missile based on disturbance rejection". Measurement and Control 52, n. 9-10 (19 ottobre 2019): 1445–60. http://dx.doi.org/10.1177/0020294019866859.
Testo completoAbstract (sommario):
In this paper, a three-dimensional partial integrated guidance and control law for the supersonic missile impacting the surface target is proposed. In the guidance loop design, a reduced-order extended state observer is integrated with feedback linearization and the pure proportional navigation law to eliminate the effects of the unknown target kinematics and the dynamic coupling between the vertical and horizontal planes. Considering the autopilot lag, two guidance schemes with different observer inputs are compared using the adjoint and frequency domain analyses. For the control loop, the angular velocity feedback is performed first for the pitch and yaw channels as conventionally done in practice, and then first-order linear active disturbance rejection control is designed for the damping-enhanced plant to deal with the fast time-varying, uncertain aerodynamics and the strong coupling effects among the three channels. Both the attitude angle and the acceleration control can be designed in a unified framework. Finally, a three-dimensional engagement scenario is performed using a six-degree-of-freedom supersonic vehicle model, and extensive simulations are carried out to validate the robustness and the high guidance precision of the proposed method.
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Bouchareb, Hanane, Samia Semcheddine, Mohamed Naguib Harmas, Kouider Nacer M’Sirdi e Aziz Naamane. "Virtual Sensors to Drive Anaerobic Digestion under a Synergetic Controller". Energies 12, n. 3 (29 gennaio 2019): 430. http://dx.doi.org/10.3390/en12030430.
Testo completoAbstract (sommario):
A robust synergetic controller using different observers is developed to drive an anaerobic digestion biogas plant. The latter, a highly nonlinear process requires prohibitive cost sensors. Furthermore, some variables are downright immeasurable rendering control an intricate challenge. Only biogas flow which can be effectively measured, due to an easily integrated low cost sensor, will be considered available and used in this work. The proposed synergetic controller depends on immeasurable system states, thus observers will be used for state estimation. Substrate and biomass concentrations required in the synergetic control law will be obtained via three virtual sensors developed for a one stage fermentation process model. The model, used in this paper, consider the mechanization phase responsible for the biogas production because the objective is to improve the amount of methane produced. A simulation study of the biogas plant control with the proposed technique is compared to a classic PID (Proportional, Integral and Derivative) approach. Comparative studies are provided for observation and control via computer simulations.
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Dey, Partha Pratim, Dulal Chandra Das, Abdul Latif, S. M. Suhail Hussain e Taha Selim Ustun. "Active Power Management of Virtual Power Plant under Penetration of Central Receiver Solar Thermal-Wind Using Butterfly Optimization Technique". Sustainability 12, n. 17 (27 agosto 2020): 6979. http://dx.doi.org/10.3390/su12176979.
Testo completoAbstract (sommario):
Striving for the suppression of greenhouse emissions, the modern power network is facing fundamental changes with the utilization of renewable energies (REs) for the future carbon-free society. The utilization of intermittent renewable-green power needs a better power management system and virtual power plant (VPP) can be a vital candidate that meets this demand. This study investigates a coordinated control grid integrated virtual power plant (VPP) in the presence of Central Receiver Solar Thermal System (CRSTS), Wind Turbine Generator (WTG), and Electric Vehicle (EV). To this end, CRSTS employed with thermal storage acts as a dispatchable renewable generating unit and coordinated control of the system units are achieved using the available control strategy on interconnected microgrids in the modified form, employing communication time delay. The proposed control strategy employs the proportional-integral (PI) and PI-derivative (PID) controller. Coordinated power control with real-time communication delay in grid integrated VPP in presence of CRSTS, WTG, and EV is a novel approach. Genetic algorithm (GA), Particle Swarm Optimization (PSO), Slap Swarm Algorithm (SSA), and recent Butterfly Optimization Algorithm (BOA) are used for tuning the necessary control parameters. The results establish the superiority of the BOA over SSA and PSO in suppressing system frequency deviations and tie line power deviation. The analysis of the dynamic response reveals that the consideration of the communication delay in the system expressively impedes the stable operation of the power system.
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Aldair, Ammar. "FPGA Based Modified Fuzzy PID Controller for Pitch Angle of Bench-top Helicopter". Iraqi Journal for Electrical and Electronic Engineering 8, n. 8 (1 giugno 2012): 12–24. http://dx.doi.org/10.37917/ijeee.8.1.2.
Testo completoAbstract (sommario):
Fuzzy PID controller design is still a complex task due to the involvement of a large number of parameters in defining the fuzzy rule base. To reduce the huge number of fuzzy rules required in the normal design for fuzzy PID controller, the fuzzy PID controller is represented as Proportional-Derivative Fuzzy (PDF) controller and Proportional-Integral Fuzzy (PIF) controller connected in parallel through a summer. The PIF controller design has been simplified by replacing the PIF controller by PDF controller with accumulating output. In this paper, the modified Fuzzy PID controller design for bench-top helicopter has been presented. The proposed Fuzzy PID controller has been described using Very High Speed Integrated Circuit Hardware Description Language (VHDL) and implemented using the Field Programmable Gate Array (FPGA) board. The bench-top helicopter has been used to test the proposed controller. The results have been compared with the conventional PID controller and Internal Model Control Tuned PID (IMC-PID) Controller. Simulation results show that the modified Fuzzy PID controller produces superior control performance than the other two controllers in handling the nonlinearity of the helicopter system. The output signal from the FPGA board is compared with the output of the modified Fuzzy PID controller to show that the FPGA board works like the Fuzzy PID controller. The result shows that the plant responses with the FPGA board are much similar to the plant responses when using simulation software based controller.
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Chenu, Karine, Nicolas Franck, Jean Dauzat, Jean-François Barczi, Hervé Rey e Jérémie Lecoeur. "Integrated responses of rosette organogenesis, morphogenesis and architecture to reduced incident light in Arabidopsis thaliana results in higher efficiency of light interception". Functional Plant Biology 32, n. 12 (2005): 1123. http://dx.doi.org/10.1071/fp05091.
Testo completoAbstract (sommario):
Plants have a high phenotypic plasticity in response to light. We investigated changes in plant architecture in response to decreased incident light levels in Arabidopsis thaliana (L.) Heynh, focusing on organogenesis and morphogenesis, and on consequences for the efficiency of light interception of the rosette. A. thaliana ecotype Columbia plants were grown under various levels of incident photosynthetically active radiation (PAR), with blue light (BL) intensity proportional to incident PAR intensity and with a high and stable red to far-red light ratio. We estimated the PAR absorbed by the plant, using data from precise characterisation of the light environment and 3-dimensional simulations of virtual plants generated with AMAPsim software. Decreases in incident PAR modified rosette architecture; leaf area decreased, leaf blades tended to be more circular and petioles were longer and thinner. However, the efficiency of light interception by the rosette was slightly higher in plants subjected to lower PAR intensities, despite the reduction in leaf area. Decreased incident PAR delayed leaf initiation and slowed down relative leaf expansion rate, but increased the duration of leaf expansion. The leaf initiation rate and the relative expansion rate during the first third of leaf development were related to the amount of PAR absorbed. The duration of leaf expansion was related to PAR intensity. The relationships identified could be used to analyse the phenotypic plasticity of various genotypes of Arabidopsis. Overall, decreases in incident PAR result in an increase in the efficiency of light interception.
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Huba, Mikulas, e Damir Vrancic. "Delay Equivalences in Tuning PID Control for the Double Integrator Plus Dead-Time". Mathematics 9, n. 4 (7 febbraio 2021): 328. http://dx.doi.org/10.3390/math9040328.
Testo completoAbstract (sommario):
The paper investigates and explains a new simple analytical tuning of proportional-integrative-derivative (PID) controllers. In combination with nth order series binomial low-pass filters, they are to be applied to the double-integrator-plus-dead-time (DIPDT) plant models. With respect to the use of derivatives, it should be understood that the design of appropriate filters is not only an implementation problem. Rather, it is also critical for the resulting performance, robustness and noise attenuation. To simplify controller commissioning, integrated tuning procedures (ITPs) based on three different concepts of filter delay equivalences are presented. For simultaneous determination of controller + filter parameters, the design uses the multiple real dominant poles method. The excellent control loop performance in a noisy environment and the specific advantages and disadvantages of the resulting equivalences are discussed. The results show that none of them is globally optimal. Each of them is advantageous only for certain noise levels and the desired degree of their filtering.
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Bantho, Sahejna, Yougasphree Naidoo, Yaser Hassan Dewir, Moganavelli Singh e Ayuvna Bantho. "Biological Activity of Combretum erythrophyllum: Antioxidant, Apoptotic, and Cytotoxic Activity of the Leaf and Stembark Extract". Horticulturae 9, n. 3 (23 febbraio 2023): 305. http://dx.doi.org/10.3390/horticulturae9030305.
Testo completoAbstract (sommario):
Species of Combretum are highly valued in Africa due to the plethora of traditional medicinal uses they may offer and the medicinally important phytometabolites they are known to contain. Traditionally, C. erythrophyllum is used to treat bacterial infections, venereal diseases, abdominal pain, sores, infertility, and labour pains, while displaying, anti-viral, anti-parasitic, cytotoxic, and mutagenic activities. There are numerous published works available on the bioactivity of phytometabolites of the leaf extracts of C. erythrophyllum; however there have been limited or no studies published on the bioactivity of the stembark. Hence, this study aimed to provide a comparative analysis of the biological activity of the leaf and stembark extracts of C. erythrophyllum. The following characters were evaluated through the emanating study: total flavonoid and phenolic content, as well as the antioxidant, cytotoxic, and apoptosis activities of the leaf and stembark extract. Methanolic extracts appeared to have the highest possible antioxidant potential among all of the tested extracts and displayed the lowest IC50 values (leaf 5.29 and stembark 4.29 µg/mL) when evaluated using the DPPH assay, the methanolic extracts appeared to quantify the largest amount of compositional phenolic content (1341.05 ± 4.4 mg/GAE/g). Methanolic extracts were the best performing, with the overall lowest IC50 values when tested against HeLa and HEK293 cells (leaf 54.53 µg/mL and stembark 18.30 µg/mL). A positive correlation between % inhibition and extract concentrations was noted for all of the assays. The extent/level of antioxidant activity was seen to be directly proportional to the flavonoid and phenolic content. Extracts with the highest total phenolic content appeared to display the strongest cytotoxic activity. This study integrated the use of fluorescence microscopy with acridine orange staining in order to accurately determine the viability of cells. A direct correlation was observed between the results obtained from the cytotoxicity and apoptosis assay. It may be concluded that the antioxidant properties, total phenolic, and total flavonoid content were directly proportional to the apoptotic and cytotoxic activity expressed by the tested extracts. Focus should now be placed on isolating phytocompounds of importance from the best performing extracts. The transformation of an isolate into a drug of pharmacological importance has yet to be appraised on a large scale. Therefore, further evaluation of this species and particularly the transformation of the isolates needs to be explored as this species has shown immense medicinal potential.
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Wang, Mofei, Shigeta Mori, Yoko Kurosawa, Juan Pedro Ferrio, Keiko Yamaji e Kohei Koyama. "Consistent scaling of whole-shoot respiration between Moso bamboo (Phyllostachys pubescens) and trees". Journal of Plant Research 134, n. 5 (11 giugno 2021): 989–97. http://dx.doi.org/10.1007/s10265-021-01320-5.
Testo completoAbstract (sommario):
AbstractBoth Moso bamboo (Phyllostachys pubescens) and tree forests have a large biomass; they are considered to play an important role in ecosystem carbon budgets. The scaling relationship between individual whole-shoot (i.e., aboveground parts) respiration and whole-shoot mass provides a clue for comparing the carbon budgets of Moso bamboo and tree forests. However, nobody has empirically demonstrated whether there is a difference between these forest types in the whole-shoot scaling relationship. We developed whole-shoot chambers and measured the shoot respiration of 58 individual mature bamboo shoots from the smallest to the largest in a Moso bamboo forest, and then compared them with that of 254 tree shoots previously measured. For 30 bamboo shoots, we measured the respiration rate of leaves, branches, and culms. We found that the scaling exponent of whole-shoot respiration of bamboo fitted by a simple power function on a log–log scale was 0.843 (95 % CI 0.797–0.885), which was consistent with that of trees, 0.826 (95 % CI 0.799–0.851), but higher than 3/4, the value typifying the Kleiber’s rule. The respiration rates of leaves, branches, and culms at the whole-shoot level were proportional to their mass, revealing a constant mean mass-specific respiration of 1.19, 0.224, and 0.0978 µmol CO2 kg− 1 s− 1, respectively. These constant values suggest common traits of organs among physiologically integrated ramets within a genet. Additionally, the larger the shoots, the smaller the allocation of organ mass to the metabolically active leaves, and the larger the allocation to the metabolically inactive culms. Therefore, these shifts in shoot-mass partitioning to leaves and culms caused a negative metabolic scaling of Moso bamboo shoots. The observed convergent metabolic scaling of Moso bamboo and trees may facilitate comparisons of the ecosystem carbon budgets of Moso bamboo and tree forests.
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Adamu , Mohammed, Abioye Mayowa e Isaac Jonah. "Decision Support System and Fuzzy Logic Controller for Capillary Irrigation System". American Journal of Computing and Engineering 6, n. 1 (17 aprile 2023): 14–28. http://dx.doi.org/10.47672/ajce.1422.
Testo completoAbstract (sommario):
Purpose: Different irrigation systems exist and they all possess various degrees of benefits in enhancing food sufficiency. In this study however, the enhancement of capillary irrigation system through an integrated fuzzy logic controller with Decision Support System (DSS) to ensure improvement in water saving for irrigation thereby improving crop yield towards food security was examined and achieved.
Methodology: An integrated fuzzy logic controller with Decision Support System (DSS) for capillary irrigation system was adopted for the enhancement of water saving for irrigation. By using this method, the challenges of irrigation management which is prevalent with capillary irrigation system is minimised using the fuzzy logic controller. An Internet of things (IoT) based weather station for computation of potential evapotranspiration (PET), for measuring rainfall and a VH400 moisture content sensor for monitoring the volumetric water content of soil, were some facilities used to control the water level depth (WLD) autonomously through a fuzzy controller simulated in MATLAB and implemented on Arduino Mega.
Findings: The soil moisture content (SMC) depicts that fuzzy controlled water level depth (WLD) is able to compensate reduction of water in crop medium that took place due to plant water uptake which changes daily. The result proves that dynamics of water supply depth has substantial effects on the water absorption flow rate, wetting pattern, soil water content and cumulative infiltration which are proportional to the water supply depth decrement.
Unique Contribution to Practice: An integrated fuzzy logic controller with Decision Support System (DSS) is a new technique proposed for managing capillary irrigation system as it offers enhanced water saving capacity (irrigation volume) based on crop demand.
24
Ramesh, Rudraram, Chinnathambi Sasi e Mani Manikandan. "An Efficient PV - Integrated UPQC System for Power Quality Enhancement Using Improved Chicken Swarm Optimization". International Journal of Experimental Research and Review 33 (30 settembre 2023): 57–70. http://dx.doi.org/10.52756/ijerr.2023.v33spl.006.
Testo completoAbstract (sommario):
In today’s world, the power distribution system's problems with Power Quality (PQ) are not unfamiliar. However, customer awareness of these issues has also risen. Likewise, there are many conventional solutions to improve the power quality. However, these traditional solutions rely on passive elements and frequently fail to respond effectively as the nature of the power system changes. Custom power devices provide adaptable solutions for many issues. Therefore, a Unified Power Quality Conditioner (UPQC) Coupled with a PV system is proposed in this paper to improve the PQ problems, including fluctuations, voltage sag and swell etc. The deployment of an Interleaved Zeta converter aids in maintaining the constant DC link voltage. In order to derive the maximum desirable power from PV system, STATCOM with Adaptive Neuro- Fuzzy Interference System (ANFIS) is used, which is fine-tuned with the help of the Improved Chicken Swarm (ICS) algorithm. In addition, UPQC with series and shunt converter is employed to decrease the current and voltage harmonics, thereby enhancing the power factor. For controlling the working of UPQC, the d-q theory-based Proportional Integral (PI) is proposed. The suggested design of PV-UPQC is evaluated and the simulation results are obtained in the MATLAB platform with a reduced THD of 2.01%.
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Rerhrhaye, Fathallah, Ilyas Lahlouh, Yassine Ennaciri, Chirine Benzazah, Ahmed El Akkary, Nacer Sefiani e Said Bouftane. "IoT-Based Data Logger for solar systems applications". ITM Web of Conferences 46 (2022): 01003. http://dx.doi.org/10.1051/itmconf/20224601003.
Testo completoAbstract (sommario):
A data logger is an electronic device that senses temperature, relative humidity, and other characteristics such as voltage and pulse by combining analog and digital measurements with programming methods. Thus, data acquisition systems (DAQSs) are frequently used in PV facilities to capture all system data to analyze and optimize plant performance. The major purpose of the project is to create a low-cost DAQS. The suggested monitoring system has been used to continuously gather and display the electrical output characteristics of a stand-alone PV system. PV produced voltage, current, and power are examples of such parameters. Furthermore, because the PV module short circuit current is directly proportional to the molar concentration, the global solar radiation may be determined by monitoring it. The proposed system is considered a good solution for collecting the system database to be ready for the analysis and optimization of the PV plant’s performance. The configurations of software and hardware of the proposed system are presented, and the proposed system's performance is tested when integrated with a small size PV system.
26
Zeng, Deliang, Yanqiu Zheng, Wei Luo, Yong Hu, Qingru Cui, Qing Li e Chen Peng. "Research on Improved Auto-Tuning of a PID Controller Based on Phase Angle Margin". Energies 12, n. 9 (6 maggio 2019): 1704. http://dx.doi.org/10.3390/en12091704.
Testo completoAbstract (sommario):
In order to realize fast and efficient tuning of the proportional-integral-derivative (PID) controller parameters in thermal power plants, this paper thoroughly analyzes the problems existing in the relay characteristic method based on the phase angle margin auto-tuning method (PM method), and proposes an improved PM auto-tuning method for the most common first order plus dead time (FOPDT) model in practical engineering applications. The improved algorithm proposes the design of the target phase angle margin and the method of plant identification. Then, the optimization algorithm is used to calculate the correction coefficient of the setting formula to obtain the PID controller parameters that minimize the integrated time absolute error (ITAE) index of the control system. Finally, through the auto-tuning experiment on the generalized control model of the main steam temperature system in thermal power plants, it is verified that the improved algorithm is superior to the traditional PM method and Ziegler–Nichols method (Z-N method), and can obtain a fast and stable control performance.
27
Sadras, Victor O., Jeff A. Baldock, Jim W. Cox e W. D. Bellotti. "Crop rotation effect on wheat grain yield as mediated by changes in the degree of water and nitrogen co-limitation". Australian Journal of Agricultural Research 55, n. 6 (2004): 599. http://dx.doi.org/10.1071/ar04012.
Testo completoAbstract (sommario):
Theoretically, growth of stressed plants is maximised when all resources are equally limiting. The concept of co-limitation could be used to integrate key factors affected by crop rotation. This paper tested the hypothesis that the effect of crop rotation on the yield of wheat is partially mediated by changes in the degree of co-limitation between nitrogen and water. Four rotations were established on a sodic, supracalcic, red chromosol in a Mediterranean-type environment of southern Australia. Rotations included wheat grown after (a) faba bean harvested for grain, (b) faba bean incorporated as green manure, (c) ryegrass pasture, or (d) medic pasture; barley was grown after wheat in all cases. The response of wheat to the rotations during 3 growing seasons was analysed in terms of nitrogen and water co-limitation, and the response of barley was taken as a measure of the persistence of rotation effects. Daily scalars quantifying water and nitrogen stress effects on tissue expansion were calculated with a crop simulation model. These scalars were integrated in a series of seasonal indices to quantify the intensity of water (SW ) and nitrogen stress (SN ), the aggregated intensity of water and nitrogen stress (SWN ), the degree of water and nitrogen co-limitation (CWN ), and the integrated effect of stress and co-limitation (SCWN 25 CWN/SWN ). The expectation is that grain yield should be inversely proportional to stress intensity and directly proportional to degree of co-limitation, thus proportional to SCWN . Combination of rotations and seasons generated a wide variation in the amount of water and inorganic nitrogen in the 1-m soil profile at the time of wheat sowing. Plant-available water ranged from 33 to 107 mm, and inorganic nitrogen from 47 to 253 kg N/ha. Larger amounts of nitrogen were found after green-manured faba bean, and smaller after grass pasture. There was a consistent effect of rotation on wheat yield and grain protein content, which persisted in subsequent barley crops. Measured grain yield of wheat crops ranged from 2.5 to 4.8 t/ha. It was unrelated to water or nitrogen stresses taken individually, inversely related to the aggregated stress index SWN , and directly related to the CWN index of co-limitation. The combination of stress and co-limitation in a single index SCWN accounted for 65% of the variation in measured crop yield. This is a substantial improvement with respect to the stress effect quantified with SWN , which accounted for 43% of yield variation. It is concluded that rotation effects mediated by changes in the relative availability of water and nitrogen can be partially accounted for by degree of resource co-limitation.
28
Yang, Ranbing, Zhichao Wang, Shuqi Shang, Jian Zhang, Yiren Qing e Xiantao Zha. "The Design and Experimentation of EVPIVS-PID Harvesters’ Header Height Control System Based on Sensor Ground Profiling Monitoring". Agriculture 12, n. 2 (16 febbraio 2022): 282. http://dx.doi.org/10.3390/agriculture12020282.
Testo completoAbstract (sommario):
In this paper, an adaptive header height control system is designed. Through the influence of the natural frequency, ωn, and damping ratio, ζ, on the system’s dynamic index, the optimal hydraulic cylinder parameters are determined comprehensively. The ground profiling monitoring mechanism and the header height feedback mechanism based on the angle sensor are designed. An integrated electromagnetic proportional valve was installed to replace the original header-controlled, electronically-controlled reversing valve, and a PWM (pulse width modulation) control-simulated counterweight test was performed. The limitation of traditional PID facing the integral saturation state is analysed, and a new EVPIVS-PID algorithm is proposed and simulated. Through the analysis of multiple groups of sample data in the field test, the accuracy of the control system in the header height control and output PWM value is demonstrated. The effectiveness of the EVPIVS-PID control algorithm to change the corresponding PID parameters based on the monitoring operation speed is analysed and demonstrated. Experiments show that the adaptive control system of header height based on ground profiling has a stable control effect. The height error of cutting stubble is not more than 2 cm, which can meet the requirements of a 5–11 km/h harvesting speed in plain areas.
29
Pratiwi, Indah Diah, Wusnah Wusnah e Nasrul ZA. "Simulasi Kontrol PID pada Boiler Sistem Tenaga Uap". Jurnal Teknologi Kimia Unimal 7, n. 1 (29 gennaio 2019): 40. http://dx.doi.org/10.29103/jtku.v7i1.1168.
Testo completoAbstract (sommario):
Kontrol PID (Proportional Integrated and Differential) merupakan salah satu jenis kontroler yang paling banyak digunakan di dunia industri. Luasnya penggunaan kontroler ini dilatarbelakangi oleh beberapa hal, salah satunya adalah dalam banyak kasus telah terbukti menghasilkan unjuk kerja relatif memuaskan. Boiler merupakan alat yang sangat penting pada sebuah industri karena steam yang dihasilkan biasanya digunakan untuk power plant dan listrik yang dihasilkan digunakan untuk mengoperasikan peralatan lain dan digunakan untuk kebutuhan proses industri. Tujuan dari penelitian ini adalah mencari waktu terbaik kontrol PID dalam merespon gangguan dengan setting nilai Kc, Ti dan Td. Penelitian ini menggunakan simulasi Hysys mode dynamic kontroler dengan menentukan PV (Process Variabel) dan OP (Output Target Object), ditentukan nilai PV maximum dan PV minimum, dengan memvariasikan nilai Kc, Ti, Td dan temperatur setpoint (270ºC, 275ºC 280ºC, 285ºC, 290ºC). Berdasarkan dari hasil pengujian yang telah dilakukan maka diperoleh waktu tercepat kontrol PID dalam merepon gangguan yaitu pada nilai Kc= 0,7; Ti= 1; Td= 0 dengan waktu rata-rata selama 1,170417 menit. Variasi nilai Kc, Ti dan Td tidak mempengaruhi besarnya heat flow yang dibutuhkan boiler. Kata Kunci:Gangguan, Heat Flow, Set point, Temperatur, Waktu
30
Mereu, S., E. Salvatori, L. Fusaro, G. Gerosa, B. Muys e F. Manes. "A whole plant approach to evaluate the water use of mediterranean maquis species in a coastal dune ecosystem". Biogeosciences Discussions 6, n. 1 (6 febbraio 2009): 1713–46. http://dx.doi.org/10.5194/bgd-6-1713-2009.
Testo completoAbstract (sommario):
Abstract. An integrated approach has been used to analyse the water relations of three Mediterranean species, A. unedo L., Q. ilex L. and P. latifolia L. co-occurring in a coastal dune ecosystem. The approach considered leaf level gas exchange, sap flow measurements and structural adaptations between 15 May and 31 July 2007, and was necessary to capture the different response of the three species to the same environment. The complexity of the response was proportional to the complexity of the system, characterized by a sandy soil with a low water retention capacity and the presence of a water table. The latter did not completely prevent the development of a drought response, and species differences in this responses have been partially attributed to a different root distribution. Sap flow of A. unedo decreased rapidly in response to the decline of Soil Water Content, while that of Q. ilex decreased only moderately. Midday leaf water potential of P. latifolia and A. unedo was between 2.2 and 2.7 MPa through the measuring period, while in Q. ilex it reached a value of 3.4 MPa at the end of the season. A. unedo was the only species to decrease the leaf area to sapwood area ratio from 23.9±1.2 (May) to 15.2±1.5 (July), as a response to drought. A. unedo also underwent an almost stepwise loss on hydraulic conductivity, such a loss didn't occur for Q. ilex, while P. latifolia was able to slightly increase hydraulic conductivity, showing how different plant compartments coordinate differently between species as a response to drought. Such different coordination affects the gas exchange between vegetation and the atmosphere, and has implications for the response of the Mediterranean coastal dune ecosystems to climate change.
31
Li, Jing, Ameen Ameen, Thamer Mohammad, Nadhir Al-Ansari e Zaher Yaseen. "A Systematic Operation Program of a Hydropower Plant Based on Minimizing the Principal Stress: Haditha Dam Case Study". Water 10, n. 9 (18 settembre 2018): 1270. http://dx.doi.org/10.3390/w10091270.
Testo completoAbstract (sommario):
Dam operation and management have become more complex recently because of the need for considering hydraulic structure sustainability and environmental protect on. An Earthfill dam that includes a powerhouse system is considered as a significant multipurpose hydraulic structure. Understanding the effects of running hydropower plant turbines on the dam body is one of the major safety concerns for earthfill dams. In this research, dynamic analysis of earthfill dam, integrated with a hydropower plant system containing six vertical Kaplan turbines (i.e., Haditha dam), is investigated. In the first stage of the study, ANSYS-CFX was used to represent one vertical Kaplan turbine unit by designing a three-dimensional (3-D) finite element (FE) model. This model was used to differentiate between the effect of turbine units’ operation on dam stability in accordance to maximum and minimum reservoir upstream water levels, and the varying flowrates in a fully open gate condition. In the second stage of the analysis, an ANSYS-static modeling approach was used to develop a 3-D FE earthfill dam model. The water pressure pattern determined on the boundary of the running turbine model is transformed into the pressure at the common area of the dam body with turbines. The model is inspected for maximum and minimum upstream water levels. Findings indicate that the water stress fluctuations on the dam body are proportional to the inverse distance from the turbine region. Also, it was found that the cone and outlet of the hydropower turbine system are the most affected regions when turbine is running. Based on the attained results, a systematic operation program was proposed in order to control the running hydropower plant with minimized principal stress at selected nodes on the dam model and the six turbines.
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Madden, L. V., G. Hughes e M. E. Irwin. "Coupling Disease-Progress-Curve and Time-of-Infection Functions for Predicting Yield Loss of Crops". Phytopathology® 90, n. 8 (agosto 2000): 788–800. http://dx.doi.org/10.1094/phyto.2000.90.8.788.
Testo completoAbstract (sommario):
A general approach was developed to predict the yield loss of crops in relation to infection by systemic diseases. The approach was based on two premises: (i) disease incidence in a population of plants over time can be described by a nonlinear disease progress model, such as the logistic or monomolecular; and (ii) yield of a plant is a function of time of infection (t) that can be represented by the (negative) exponential or similar model (ζ(t)). Yield loss of a population of plants on a proportional scale (L) can be written as the product of the proportion of the plant population newly infected during a very short time interval (X′(t)dt) and ζ(t), integrated over the time duration of the epidemic. L in the model can be expressed in relation to directly interpretable parameters: maximum per-plant yield loss (α, typically occurring at t = 0); the decline in per-plant loss as time of infection is delayed (γ; units of time-1); and the parameters that characterize disease progress over time, namely, initial disease incidence (X0), rate of disease increase (r; units of time-1), and maximum (or asymptotic) value of disease incidence (K). Based on the model formulation, L ranges from αX0 to αK and increases with increasing X0, r, K, α, and γ-1. The exact effects of these parameters on L were determined with numerical solutions of the model. The model was expanded to predict L when there was spatial heterogeneity in disease incidence among sites within a field and when maximum per-plant yield loss occurred at a time other than the beginning of the epidemic (t > 0). However, the latter two situations had a major impact on L only at high values of r. The modeling approach was demonstrated by analyzing data on soybean yield loss in relation to infection by Soybean mosaic virus, a member of the genus Potyvirus. Based on model solutions, strategies to reduce or minimize yield losses from a given disease can be evaluated.
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Glibovytska, N. I., e V. I. Parpan. "The metabolic characteristics of small-leaved linden (Tilia cordata Mill.) adaptation under urbanized environment conditions". Ecology and Noospherology 25, n. 1-2 (13 marzo 2014): 19–25. http://dx.doi.org/10.15421/031402.
Testo completoAbstract (sommario):
The increase of anthropogenic pollution in urboecosystem leads to degradation of woody vegetation that adversely affects the functioning of the protective green space. The impact of anthropogenic loading is shown by change of a series of physiological and biochemical processes and the formation of adaptive mechanisms in plants. The ability of plants to respond appropriately to external stimuli is a necessary condition of their existence and adaptation to environmental conditions. Metabolic reorganization in plant cells that occur in response to exogenous pollutants plays a major role in determining their resistance to adverse factors. As the body adapts within genetically inherited norms reactions, its ability to withstand fluctuations in environmental factors is determined by individual ecological potency. One of the most sensitive species to anthropogenic pollution is small-leaved linden (Tilia cordata Mill.), which is widely presented in dendroflora of Ukraine cities. Analysis of the species metabolic characteristics in terms of urbanized environment and the assessment of the prospects of identified changes using in practice bioindication research is the goal of this work. One of the central components of plant metabolism is protein metabolism. In terms of all local ecotypes of the studied urboecosystem a statistically significant change in the content of total nitrogen and protein in small-leaved linden leaf plates to control was observed. Reducing the concentration of total nitrogen and protein in species leaves is in accordance with the degree of urbotechnogenic pressure enhancement in the next different-functional landscape city zones: the area of the integrated landscaping → the area of the house-building complex → the area of transport routes → the area of industrial complexes. Carbohydrate metabolism in plants under stressful conditions changes towards accumulation of soluble sugars, which takes place in local ecotypes of Ivano-Frankivsk urboecosystem. The content of the above-mentioned substances in lime leaves increases from 4.6 % in the area of integrated landscaping to 23.8 % in the area of industrial complexes, compared to the background territory. The content of mineral elements in Tilia cordata leaves within the city ranges from 119 mg/g in the area of the integrated landscaping up to 159 mg/g in the area of industrial complexes, respectively, 1.5– 2 times higher than the figure on the background area. Fall of starch concentration in the small-leaved leaves is in accordance with the level of anthropogenic impact intensification in the local city ecotypes, ranging from 1.2 times in the area of integrated landscaping to 1.6 times in the area of industrial complexes. Reducing the polysaccharide amount in plant’s assimilation organs is caused by inhibition of photosynthesis and the activity of enzymes that control its metabolism. In terms of urboecosystem the close correlation relationships were set between the vast majority of the analyzed organic and mineral components of small-leaved linden leaves. The presence of water-soluble carbohydrates in leaves significantly correlated directly proportional with the content of mineral elements and inversely proportional to the number of nitrogenous compounds and polysaccharides. Accumulation of ash by lime leaves adversely affects the synthesis of proteins, starch and cellulose accumulation and stimulates the formation of lipids, which clearly reflects environmental urbotechnogenic pressure and formation of defensive reactions in plants. Nitrogenous compounds are formed in close direct connection with polysaccharides and at the same time have an inverse correlation with the parameters of the fat-like substances content in the species leaf plates. Positive dependence was found between the cellulose and starch content in assimilative organs, accurate feedback was established between the synthesis of starch and lipids. Fat-like compounds metabolism is associated by weak positive relationship with the content of water soluble carbohydrates in leaves, but is not correlated with cellulose tissues content. Given the informative content of the main parameters of mineral and organic components of Tilia cordata leaves and species sensitivity to anthropogenic pollution, it is rational to use it as bioindicator in assessing the ecological condition of urbanized territories.
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Eze, C. D., A. I. Adesoye e C. A. Adeosun. "Effect of gamma radiation on morphological and molecular character of Sphenostylis stenocarpa (Hoechst. ex. A. Rich.) Harms." Ghana Journal of Science 62, n. 2 (1 gennaio 2022): 79–90. http://dx.doi.org/10.4314/gjs.v62i2.8.
Testo completoAbstract (sommario):
Genetic variation in two varieties of Sphenostylis stenocarpa (Hochst.ex A.Rich.) Harms was created using different doses of gamma-rays with the aim of increasing variability among the landraces for better morpho-agronomic characteristics. The two varieties responded differently to the doses of the treatment. The mutagen stimulated the germination percentage in both varieties. The highest germination percentage was observed at 200Gy for Tss86 while for Tss10 it was observed at 25Gy. It showed variation on the germination and growth parameters evaluated. The highest plant height (74.17±4.42) for Tss10 was observed at 25Gy while for Tss86, 100Gy gave the highest mean of 79.6±8.02. Molecular evaluation revealed variation in the patterns of RAPD profile between irradiated plants and control. The RAPD primers showed 82.9% polymorphism. Also, as observed from the similarity coefficient values, the trend of the genetic variability was not proportional to the doses of the gamma ray. The similarity indices ranged from 0.09 to 0.60 with 3 distinct cluster groups identified at 0.64. The variant of Tss86 at 250Gy was found to be the most diverse. Thus, this integrated approach can be used for carrying out the mutation-assisted breeding and subsequent selection of desired mutants using molecular markers in AYB.
35
Almabrok, Abdoalnasir, Mihalis Psarakis e Anastasios Dounis. "Fast Tuning of the PID Controller in An HVAC System Using the Big Bang–Big Crunch Algorithm and FPGA Technology". Algorithms 11, n. 10 (28 settembre 2018): 146. http://dx.doi.org/10.3390/a11100146.
Testo completoAbstract (sommario):
This article presents a novel technique for the fast tuning of the parameters of the proportional–integral–derivative (PID) controller of a second-order heat, ventilation, and air conditioning (HVAC) system. The HVAC systems vary greatly in size, control functions and the amount of consumed energy. The optimal design and power efficiency of an HVAC system depend on how fast the integrated controller, e.g., PID controller, is adapted in the changes of the environmental conditions. In this paper, to achieve high tuning speed, we rely on a fast convergence evolution algorithm, called Big Bang–Big Crunch (BB–BC). The BB–BC algorithm is implemented, along with the PID controller, in an FPGA device, in order to further accelerate of the optimization process. The FPGA-in-the-loop (FIL) technique is used to connect the FPGA board (i.e., the PID and BB–BC subsystems) with the plant (i.e., MATLAB/Simulink models of HVAC) in order to emulate and evaluate the entire system. The experimental results demonstrate the efficiency of the proposed technique in terms of optimization accuracy and convergence speed compared with other optimization approaches for the tuning of the PID parameters: sw implementation of the BB–BC, genetic algorithm (GA), and particle swarm optimization (PSO).
36
Gopal, Nand, e Dilbagh Panchal. "A STRUCTURED FRAMEWORK FOR RELIABILITY AND RISK EVALUATION IN THE MILK PROCESS INDUSTRY UNDER FUZZY ENVIRONMENT". Facta Universitatis, Series: Mechanical Engineering 19, n. 2 (11 luglio 2021): 307. http://dx.doi.org/10.22190/fume201123004g.
Testo completoAbstract (sommario):
This paper aims at proposing a novel integrated framework for studying reliability and risk issues of the curd unit in a milk process industry under uncertain environment. The considered plant’s complex series-parallel configuration was presented using the Petri Net (PN) modeling. The Fuzzy Lambda-Tau (λ-τ) approach was applied to study and analyze the reliability aspects of the considered plant. Failure dynamics of the curd unit has been analyzed with respect to increasing/ decreasing trends of the tabulated reliability indices. Availability of the considered plant shows a decreasing trend with an increase in spread values. For improving the system’s availability, a risk analysis was done to identify the most critical failure causes. Using the traditional FMEA approach, the FMEA sheet was generated on the basis of expert’s knowledge/experience. The Fuzzy-Complex Proportional Assessment (FCOPRAS) approach was applied within FMEA approach for identification of critical failure causes associated with different subsystem/components of the considered plant. In order to check the consistency of the ranking results, the Fuzzy Technique for Order of Preference by Similarity to Ideal Solution (FTOPSIS) was applied within the FCOPRAS approach. Ranking results are compared for checking consistency and robustness of critical failure causes related decision making which would be useful in designing the finest maintenance schedule for the considered curd unit. Overheating/moisture lead to winding failure (MSCP5), visible sediment of milk jam in filter (MBFP3), improper quality of oil (H4), blade breakage (CTK4), wearing in gears (PFM11), and cylinder leakage (CFM7) were recognized as the most critical failure causes contributing to system unavailability. The analysis results were supplied to the maintenance manager for framing a suitable time-based maintenance intervals policy for the considered unit.
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Whelan, Mary E., Leander D. L. Anderegg, Grayson Badgley, J. Elliott Campbell, Roisin Commane, Christian Frankenberg, Timothy W. Hilton et al. "Scientific Communities Striving for a Common Cause: Innovations in Carbon Cycle Science". Bulletin of the American Meteorological Society 101, n. 9 (1 settembre 2020): E1537—E1543. http://dx.doi.org/10.1175/bams-d-19-0306.1.
Testo completoAbstract (sommario):
Abstract Where does the carbon released by burning fossil fuels go? Currently, ocean and land systems remove about half of the CO2 emitted by human activities; the remainder stays in the atmosphere. These removal processes are sensitive to feedbacks in the energy, carbon, and water cycles that will change in the future. Observing how much carbon is taken up on land through photosynthesis is complicated because carbon is simultaneously respired by plants, animals, and microbes. Global observations from satellites and air samples suggest that natural ecosystems take up about as much CO2 as they emit. To match the data, our land models generate imaginary Earths where carbon uptake and respiration are roughly balanced, but the absolute quantities of carbon being exchanged vary widely. Getting the magnitude of the flux is essential to make sure our models are capturing the right pattern for the right reasons. Combining two cutting-edge tools, carbonyl sulfide (OCS) and solar-induced fluorescence (SIF), will help develop an independent answer of how much carbon is being taken up by global ecosystems. Photosynthesis requires CO2, light, and water. OCS provides a spatially and temporally integrated picture of the “front door” of photosynthesis, proportional to CO2 uptake and water loss through plant stomata. SIF provides a high-resolution snapshot of the “side door,” scaling with the light captured by leaves. These two independent pieces of information help us understand plant water and carbon exchange. A coordinated effort to generate SIF and OCS data through satellite, airborne, and ground observations will improve our process-based models to predict how these cycles will change in the future.
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Adesina, Jacobs Mobolade, Adeolu Rufus Jose e Yallappa Rajashekar. "Bio-efficacy of Clerodendrum capitatum (Willd) Schumachet. Thonn. (Lamiales: Verbenaceae) against Dermestes maculatus De Geer, 1774 (Coleoptera: Dermestidae) larvae infestation on smoked catfish Claria gariepinus (Burchell, 1822) (Siluriformes: Clariidae)". Brazilian Journal of Biological Sciences 3, n. 5 (2016): 37. http://dx.doi.org/10.21472/bjbs.030504.
Testo completoAbstract (sommario):
Studies were conducted under ambient condition to assess the efficacy of Clerodendrum capitatum (Willd) Schumachet. Thonn. (Lamiales: Verbenaceae) against larvae infestation and adult emergence of Dermestes maculatus De Geer, 1774 (Coleoptera: Dermestidae) on smoked dried catfish Claria gariepinus (Burchell, 1822) (Siluriformes: Clariidae). The leaf powder was admixed at 2.5 g, 3.0 g, 4.0 g and 5.0 g/15 g to disinfected smoke-dried catfish Clarias gariepinus separately in a 125 mL plastic container. Ten newly emerged (0-72 h) larvae of D. maculatus were introduced into each of the plastic containers. Efficacy of Clerodendrum capitatum was assessed based on percentage larval mortality, adult emergence reduction and weight loss. Results showed that the plant powder cause significantly (p < 0.05) larval mortality compared to the untreated fish at 24 h, 48 h and 72 h post infestation. Percentage reduction of adult emergence was not significant (p > 0.05) in treated fish samples compared to untreated sample. While fish sample protected with powder of Clerodendrum capitatum, exhibit significant (p < 0.05) low weight loss as against weight loss observed in untreated fish. The efficacy of Clerodendrum capitatum is inversely proportional to increase in dosage rate. This study clearly demonstrated the larvicidal potential of Clerodendrum capitatum powder in offering effective protection against infestation and damage by D. maculatus and recommended for utilization in integrated post-harvest management strategies of smoke-dried fish.
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Su, Dongxu, Weixiang Yao, Fenghua Yu, Yihan Liu, Ziyue Zheng, Yulong Wang, Tongyu Xu e Chunling Chen. "Single-Neuron PID UAV Variable Fertilizer Application Control System Based on a Weighted Coefficient Learning Correction". Agriculture 12, n. 7 (13 luglio 2022): 1019. http://dx.doi.org/10.3390/agriculture12071019.
Testo completoAbstract (sommario):
Agricultural unmanned aerial vehicles (UAVs), which are a new type of fertilizer application technology, have been rapidly developed internationally. This study combines the agronomic characteristics of rice fertilization with weighted coefficient learning-modified single-neuron adaptive proportional–integral–differential (PID) control technology to study and design an aerial real-time variable fertilizer application control system that is suitable for rice field operations in northern China. The nitrogen deficiency at the target plot is obtained from a map based on a fertilizer prescription map, and the amount of fertilizer is calculated by a variable fertilizer application algorithm. The advantages and disadvantages of the two control algorithms are analyzed by a MATLAB simulation in an indoor test, which is integrated into the spreading system to test the effect of actual spreading. A three-factor, three-level orthogonal test of fertilizer-spreading performance is designed for an outdoor test, and the coefficient of variation of particle distribution Cv (a) as well as the relative error of fertilizer application λ (b) are the evaluation indices. The spreading performance of the spreading system is the best and can effectively achieve accurate variable fertilizer application when the baffle opening is 4%, spreading disc speed is 600 r/min, and flight height is 2 m, with a and b of evaluation indexes of 11.98% and 7.02%, respectively. The control error of the spreading volume is 7.30%, and the monitoring error of the speed measurement module is less than 30 r/min. The results show that the centrifugal variable fertilizer spreader improves the uniformity of fertilizer spreading and the accuracy of fertilizer application, which enhances the spreading performance of the centrifugal variable fertilizer spreader.
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Kong, Yun, Dave Llewellyn e Youbin Zheng. "Response of growth, yield, and quality of pea shoots to supplemental light-emitting diode lighting during winter greenhouse production". Canadian Journal of Plant Science 98, n. 3 (1 giugno 2018): 732–40. http://dx.doi.org/10.1139/cjps-2017-0276.
Testo completoAbstract (sommario):
Low natural light levels during the winter months are a major limiting factor for greenhouse production in northern regions. To determine the effects of supplemental lighting (SL) on winter greenhouse production of pea shoots, crop growth, yield, and quality were investigated under the treatments of supplemental photosynthetic photon flux density (PPFD) of 50, 80, 110, and 140 μmol m−2 s−1, all with a 16 h photoperiod, plus a no-SL control treatment, inside a Canadian greenhouse from December to March. Light-emitting diodes with a red to blue PPFD ratio of 4:1 and peak wavelengths at 665 and 440 nm were used for the lighting treatment. During the trial period, the average natural daily light integral (DLI) inside the greenhouse was 5.3 mol m−2 d−1 and the average daily temperature was around 13 °C. Compared with the no-SL control, SL of 50–140 μmol m−2 s−1 increased stem length and leaf number before the first harvest and promoted the cumulative yield (kg m−2) of pea shoots throughout the five harvest times. The total yield (kg m−2) of five harvests and weekly average stem extension rate were proportional to supplemental PPFD within the range of 0–140 μmol m−2 s−1; however, SL of 50–80 μmol m−2 s−1, corresponding to total (natural + supplemental) DLI of 8.1–9.8 mol m−2 d−1, resulted in the best integrated quality based on the evaluation of individual fresh mass, soluble solids content, succulence, and firmness. Therefore, a total DLI ranging between 8.1 and 9.8 mol m−2 d−1 can be suggested as a target for winter greenhouse production of pea shoots under conditions similar to this trial.
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Jiang, Rui, Pei Wang, Yan Xu, Zhiyan Zhou, Xiwen Luo e Yubin Lan. "A Novel Illumination Compensation Technique for Multi-Spectral Imaging in NDVI Detection". Sensors 19, n. 8 (18 aprile 2019): 1859. http://dx.doi.org/10.3390/s19081859.
Testo completoAbstract (sommario):
To overcome the dependence on sunlight of multi-spectral cameras, an active light source multi-spectral imaging system was designed and a preliminary experimental study was conducted at night without solar interference. The system includes an active light source and a multi-spectral camera. The active light source consists of four integrated LED (Light Emitting Diode) arrays and adjustable constant current power supplies. The red LED arrays and the near-infrared LED arrays are each driven by an independently adjustable constant current power supply. The center wavelengths of the light source are 668 nm and 840 nm, which are consistent with that of filter lens of the Rededge-M multi-spectral camera. This paper shows that the radiation intensity measured is proportional to the drive current and is inversely proportional to the radiation distance, which is in accordance with the inverse square law of light. Taking the inverse square law of light into account, a radiation attenuation model was established based on the principle of image system and spatial geometry theory. After a verification test of the radiation attenuation model, it can be concluded that the average error between the radiation intensity obtained using this model and the actual measured value using a spectrometer is less than 0.0003 w/m2. In addition, the fitting curve of the multi-spectral image grayscale digital number (DN) and reflected radiation intensity at the 668 nm (Red light) is y = −3484230x2 + 721083x + 5558, with a determination coefficient of R2 = 0.998. The fitting curve with the 840 nm (near-infrared light) is y = 491469.88x + 3204, with a determination coefficient of R2 = 0.995, so the reflected radiation intensity on the plant canopy can be calculated according to the grayscale DN. Finally, the reflectance of red light and near-infrared light can be calculated, as well as the Normalized Difference Vegetation Index (NDVI) index. Based on the above model, four plants were placed at 2.85 m away from the active light source multi-spectral imaging system for testing. Meanwhile, NDVI index of each plant was measured by a Greenseeker hand-held crop sensor. The results show that the data from the two systems were linearly related and correlated with a coefficient of 0.995, indicating that the system in this article can effectively detect the vegetation NDVI index. If we want to use this technology for remote sensing in UAV, the radiation intensity attenuation and working distance of the light source are issues that need to be considered carefully.
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Harby, Mahmoud Essam, Said Elsayed Elmasry, Adel Elsamahy, Luis Marroyo e Javier Marcos. "Impact of plug-in hybrid electric vehicles on power system with high wind power penetration". IAES International Journal of Robotics and Automation (IJRA) 8, n. 2 (1 giugno 2019): 146. http://dx.doi.org/10.11591/ijra.v8i2.pp146-154.
Testo completoAbstract (sommario):
The rising energy independence and environmental concerns are key drivers in the growing popularity of plug-in hybrid electric vehicles (PHEVs). Because of the intermittent nature of the renewable energy sources, this may cause a high-frequency oscillation of the power system. From another aspect, all the PHEVs have in common the batteries, which provide the storage capability that can be effectively harnessed when the vehicles are integrated into the grid. Such a storage capability can effectively integrate wind power into the grid and all indicators signalize that the PHEVs are the most promising technology of the future transportation system. In this paper, different case studies are applied on one area power system to show the effect of the high wind energy penetration on the power system frequency and how the PHEVs can play an effective role in mitigating the power system frequency oscillation and supporting the more penetration of the wind energy into smarter electrical grids. In addition, an advanced controller has been designed to improve the frequency response and to compensate the delay of the system. The designed controller is a genetic algorithm (GA) based PID (proportional-integral-derivative) controller, it has been proposed for tuning optimized PID parameters. The results show that the controller has played an effective role in decreasing the response overshoot and settling time when used with the PHEVs. The used variable load, the thermal power plant parameters, and the wind turbine parameters are the same for the five case studies.
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Kumar, Ajay, Deepak Kumar Gupta, Sriparna Roy Ghatak, Bhargav Appasani, Nicu Bizon e Phatiphat Thounthong. "A Novel Improved GSA-BPSO Driven PID Controller for Load Frequency Control of Multi-Source Deregulated Power System". Mathematics 10, n. 18 (7 settembre 2022): 3255. http://dx.doi.org/10.3390/math10183255.
Testo completoAbstract (sommario):
In this paper, a novel improved gravitational search algorithm–binary particle swarm optimization (IGSA-BPSO) driven proportional-integral-derivative (PID) controller is proposed to deal with issues of automatic generation control (AGC) of interconnected multi-source (thermal-hydro-gas) multi-area deregulated power systems. The effectiveness and robustness of the proposed controller is compared and analyzed with GSA and PSO-driven PID controllers. The simulated and mathematically formulated results show the superiority of the proposed IGSA-BPSO driven PID controller compared with the other two techniques in settling time, overshoot, and convergence time. The two-area test system considered in this article is integrated with a thermal, hydro, and gas turbine power plant. Integral time multiplied by absolute error (ITAE) is used as the objective function (minimization) by optimization techniques for getting optimum parameters of PID controllers installed in each area. The system’s dynamics are examined using poolco, bilateral, and contract violation cases under a deregulated environment, and the comparative results are shown to analyze the efficacy of the proposed concept. Physical constraints such as generation rate constraints (GRC) and time-delay (TD) have been considered in the system as a realistic approach. This paper considers an accurate AC-DC tie-link model for the proposed AGC mechanism. Dynamic load change condition is tested and verified. The variations of different parameters will be used in the robustness analysis of the proposed system. The comparison shows that the designed controllers are more robust and produce better results than those considered as references.
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Nahak, Narayan, e Samarjeet Satapathy. "A Coordinated Pumped Storage Dual Compensated Hydro Governor with PSS Action to Damp Electromechanical Power Oscillations". International Transactions on Electrical Energy Systems 2022 (19 ottobre 2022): 1–24. http://dx.doi.org/10.1155/2022/8802143.
Testo completoAbstract (sommario):
Subject to increasing penetrations of renewable sources like solar photovoltaic (SPV) and wind energy sources, power system oscillation damping is going to be a critical challenge for system operators. This work proposes a new dual compensated governor (DCG) in coordination with a power system stabilizer (PSS) of a pumped storage hydro plant for power oscillation damping subject to intermittent SPV and wind penetration for a hydro, wind, and SPV integrated power system. The phase lag provided by the hydro governor is compensated by additional phase lead contributed by the dual compensation, where speed and real power deviations brought by uncertain SPV and wind penetrations are simultaneously controlled by two lead-lag controllers before being applied to conventional Proportional-Integral-Derivative (PID) governor. Again, subject to critical oscillatory unstable conditions, the DCG is coordinated with PSS through a multiobjective function employing a new modified Differential Evolutionary-Particle swarm optimization (MDEPSO) algorithm. Different case studies with sudden and random SPV and wind penetrations being executed with the proposed controller considering a two area four machine and 39 bus multimachine system with pumped storage hydro units to observe system oscillations are considered. The proposed damping control action has been implemented to damp these oscillations, and the damped response has been analyzed with eigenvalue distributions and Bode plots with sensitivity analysis. The proposed action is found to be much more efficient in contrast to conventional PID governor and PSS damping action. Also, the usage of present hydro governors can be much improved by this coordinated controller action.
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Shukla, Hiramani, Srete Nikolovski, More Raju, Ankur Singh Rana e Pawan Kumar. "SMES-GCSC Coordination for Frequency and Voltage Regulation in a Multi-Area and Multi-Source Power System with Penetration of Electric Vehicles and Renewable Energy Sources". Energies 16, n. 1 (26 dicembre 2022): 251. http://dx.doi.org/10.3390/en16010251.
Testo completoAbstract (sommario):
Frequency, tie-line power, and the terminal voltages of synchronized generators must all be kept within prescribed limits to ensure the stability of an interconnected power grid through combined automatic generation control (AGC) and automatic voltage regulator (AVR) loops. Thermal power plants, electric vehicles, and renewable energy sources—including solar and wind, geothermal, and solar thermal power plants—form the two-area integrated power system in present research. A new cascade controller named the cascaded proportional integral derivative (PID) and fractional-order PID (CPID-FOPID) controller is proposed for the first time, whose performance is compared with the PID and FOPID controller. The results show that the proposed cascade controller outperforms PID and FOPID in delivering superior dynamic characteristics, including short settling times and low oscillation amplitudes. A new metaheuristic algorithm named the coot algorithm was applied to optimize the parameters of these controllers. The suggested controller outperforms FOPID in the combined AGC and AVR problem under uncertain conditions (random load disturbance, variable input of solar irradiation, and wind power). Robustness of the controller is tested with significant variation in the turbine time constant of the thermal and geothermal power plant. In this study, authors also investigated the best possible coordination between the superconducting magnetic energy storage (SMES) and gate-controlled series capacitor (GCSC) devices to control both voltage and frequency simultaneously. The effect of communication time to the power system is analyzed in this study. Additionally, the obtained results are satisfactorily validated using OPAL-RT real-time digital simulator.
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Pagano, Stefano, Michele Russo, Salvatore Strano e Mario Terzo. "A mixed approach for the control of a testing equipment employed for earthquake isolation systems". Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 228, n. 2 (4 aprile 2013): 246–61. http://dx.doi.org/10.1177/0954406213484424.
Testo completoAbstract (sommario):
This paper presents an activity concerning the modelling and control of a system adopted to perform shear tests on seismic isolators. The test rig consists of a hydraulic actuation system that drives a sliding table mounted on linear bearings. The system is characterized by non-linearities such as hydraulic proportional valve dead zone and frictions. A non-linear model is derived and then employed for parameter identification procedure. The test rig needs a suitable controller able to guarantee the desired table displacement in presence of unknown reaction force of the device under test. The proposed approach consists of a feedforward control integrated with a feedback one. The feedforward control law takes the form of a non-linear inverse model of the system. In this way, it is possible to obtain the desired target without affecting the stability of the test rig. The feedback control has the function to compensate for tracking error due to the model uncertainties and the unknown isolator reaction force. Therefore, the feedback control is not required to compensate for the large non-linearities: in this manner, it is possible to obtain good tracking results without the increasing of the feedback control gain that would change the stability properties of the plant. Numerical simulations have been performed in order to evaluate the goodness of the designed control with and without the specimen under test. Experimental tests show that the controlled system simulations are able to predict the controller performance. The experimental results also confirm that the performance of the proposed controller fully satisfy the standards concerning the testing procedure of seismic isolators.
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Babu, Naladi Ram, Sanjeev Kumar Bhagat, Tirumalasetty Chiranjeevi, Mukesh Pushkarna, Arindita Saha, Hossam Kotb, Kareem M. AboRas et al. "Frequency Control of a Realistic Dish Stirling Solar Thermal System and Accurate HVDC Models Using a Cascaded FOPI-IDDN-Based Crow Search Algorithm". International Journal of Energy Research 2023 (5 agosto 2023): 1–18. http://dx.doi.org/10.1155/2023/9976375.
Testo completoAbstract (sommario):
Unbalancing the real power in power system leads to fluctuation in system frequency which can cause the several negative effects on the performance and reliability of the interconnected power system. Therefore, to deal with this, the load frequency control (LFC) of a three-area asymmetric thermal power system integrated with a solar thermal power plant (STPP), a realistic dish-stirling solar thermal system (DSTS), and an accurate high voltage direct current (HVDC) link are presented in this work. For the suggested system, a novel cascade controller called fractional-order proportional-integral and integral-double-derivative with filter (FOPI-IDDN) is designed. By minimising a newly proposed performance index called the HPA-ISE and adjusting the controller and other system model parameters using a metaheuristic method called the crow search algorithm (CS). When comparing the system dynamics, it was found that the suggested FOPI-IDDN controller outperformed the FOPI, PIDN, and FOPIDN controllers. The findings of this study show that HPA-ISE shows approximately 30% and 60% improvements in settling time (ST) and peak overshoots (POS) for frequency response, and 32% and 18% improvements for the tie power responses in terms of ST and POS over ISE criteria. Also, studies on different area capacity ratios have shown that a system connected to a greater capacity ratio operates better. The realistic DSTS system with fixed and recurring insolation in area 1 and area 2 outperforms the others, according to experiments using different DSTS insolation. Also, it is discovered that the parallel AC-AHVDC link study is superior to the AC and HVDC connection research. Moreover, it seems from the sensitivity study that the CS-optimized FOPI-IDDN controller improvements obtained under normal settings are consistent across a wide range of changes.
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Wibowo, Kusno, e Wage Komarawidjaja. "UJI TANAMAN TALAS (Colocasia esculenta) SEBAGAI AGEN FITOREMEDIASI AIR SUNGAI CIKAPUNDUNG". Jurnal Teknologi Lingkungan 13, n. 3 (13 dicembre 2016): 283. http://dx.doi.org/10.29122/jtl.v13i3.1398.
Testo completoAbstract (sommario):
Pencemaran sungai akibat akumulasi limbah domestik dan industri merupakan tantangan yang serius bagi kelestarian hidup biota perairan. Limbah domestik/rumah tangga yang sering dibuang ke perairan dapat mengganggu ekosistem yang ada di perairan tersebut. Sejauh ini berbagai upaya sudah mulai dilakukan industri dengan pembuatan instalasi limbah terpadu, namun upaya tersebut masih belum maksimal karena rendahnya kesadaran masyarakat dan lemahnya pengawasan dari instansi terkait. Salah satu upaya untuk mengurangi limbah domestik adalah dengan membuat biology irigation dengan memanfaatkan tanaman talas Colocasiaesculenta. Studi pemanfaatan tanaman air untuk pengolahan air limbah domestik dalam sistem biology irigation ini dilakukanuntuk mengetahui efisiensi penyerapan unsur hara oleh C. esculenta. Metode penelitian yang diterapkan adalah menumbuhkan C. esculenta dalam suatu wadah percobaan race ways yang dialiri air limbah domestic dengan sistem subsurface flow (SSF). Hasilpenelitian menunjukkanbahwa secara fisik C.Esculenta dapat tumbuh lebih baik pada substrat yang mengandung air sungai Cikapundung dibandingkan dengan C.Esculenta yang ditumbuhkan pada substrat yang ditambahkan air sumur. Hal tersebut ditunjukkan oleh perbedaan pertumbuhan panjang dan berat tanaman tersebut. Hasil analisis parameter karbon organik (C-organik), nitrogen (N-kejdahl) dan fosfat (P) pada jaringan tanaman talas (bagian daun dan akar) menunjukkan adanya peningkatan konsentrasi bahan organic dalam jaringan tanaman tersebut yang berbanding lurus dengan pertumbuhan tanaman talas (tinggi dan berat tanaman talas), sebagaimana ditunjukkan oleh konsentrasi penyerapan C sebesar 2000 mg dan N 100 mg selama 63 hari. Kata kunci : Colocasia esculenta, limbah domestik, fitoremediasi. AbstractPollution of rivers due to the accumulation of domestic and industrial wasteis aserious challenge to the survival ofaquatic biota. Domestic waste/ household is often thrown into the water can interfere waters ecosystems. So far, many efforts have been done such as installation integrated waste treatment, but these efforts are not yet fulfill the requirement due to low awareness and lack of oversight agencies. One of the efforts to reduce domestic wasteis by making use of plant biology irrigation with Colocasia esculenta. Study ofutilization of aquatic plants for domestic wastewater treatment systems biology irrigation was conducted to determine the efficiency of nutrient uptake by C.esculenta. The research method was applied by growing C.esculenta in an experimental container -carrying raceways domestic wastewater system with subsurface flow (SSF). The results showed that physical C.Esculenta may grow well on substrates containing water Cikapundung river compared to C.Esculentagrown ona substrateis added waterwells. This is shown by the differences in growth and weight of the plants. The results of the Laboratory analysis of organic carbon (C-organic), nitrogen (N-kejdahl) and phosphate (P) on the taro plant (the leaves and roots) showed an increase nutrient in plant tissues which is directly proportional to the growth of taro plants (taro plant height and weight), as shown by a concentration of 2000 mg C sequestration and N100 mg for 63 days. Keywords: Colocasia esculenta, domestic waste, phytoremediation.
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ABBASI, M. KALEEM, ABDUL KHALIQ, M. SHAFIQ, MUSHTAQ KAZMI e IMRAN ALI. "COMPARATIVE EFFECTIVENESS OF UREA N, POULTRY MANURE AND THEIR COMBINATION IN CHANGING SOIL PROPERTIES AND MAIZE PRODUCTIVITY UNDER RAINFED CONDITIONS IN NORTHEAST PAKISTAN". Experimental Agriculture 46, n. 2 (8 marzo 2010): 211–30. http://dx.doi.org/10.1017/s0014479709991050.
Testo completoAbstract (sommario):
SUMMARYA field experiment was conducted to evaluate the comparative effectiveness of poultry manure, urea N and the integrated use of both in changing soil properties, nutrient uptake, yield and yield attributes of maize grown at Rawalakot, Azad Jammu and Kashmir, Pakistan. Treatments include control without any amendment (N0); urea N (UN) = 120 kg N ha−1 (N120U); UN = 150 kg N ha−1(N150U); poultry manure (PM) = 120 kg N ha−1(N120PM); PM = 150 kg N ha−1(N150PM); UN = 90 kg N ha−1+ PM = 30 kg N ha−1(N90U+30PM); UN = 60 kg N ha−1+ PM = 60 kg N ha−1(N60U+60PM); UN = 30 kg N ha−1+ PM = 90 kg N ha−1(N30U+90PM). N fertilization from different sources and combinations increased dry matter yield from 5206 kg ha−1 in the control to 5605–5783 kg ha−1 and grain yield increased from 1911 kg ha−1 to 2065–3763 kg ha−1. Application of the highest rate of urea N recorded the highest grain yields of 3763 kg ha−1, double the control. The proportional increase for N90U+30PM and N60U+60PM was 85 and 83% while PM alone gave lower yields (41 and 44%) than the respective urea N treatments. Integrated use of urea + PM proved superior to other treatments in enhancing the uptake of N, P and K in plants. Averaged across two years, uptake of N, P and K in N90U+30PM and N60U+60PM was 88 and 85, 16.5 and 17.5, and 48.5 and 53.5 kg ha−1, respectively compared to 52.5, 11.5 and 33.5 kg ha−1 in the control. Nitrogen use efficiency (NUE) varied from 29% in PM treatments to 30–39% in combined treatments while NUE of 40% was recorded for urea N treatments. Application of PM lowered soil bulk density from 1.19 t m−3 in the control to 1.10 and 1.05 t m−3 in N120PM and N150U, enhanced pH from 7.39 to 7.65 and 7.78 and increased soil organic matter (22 and 32%), total N (21 and 26%), available P (44 and 55%) and available K (10 and 15%) compared with the control. Economic analysis suggested the use of 50% recommended mineral N (60 kg N ha−1) with PM saves the mineral N fertilizer by almost 50% compared to a system with only mineral N application. In addition, increase in N efficiency, plant nutrition and soil fertility associated with combined treatment would help to minimize the use of high cost synthetic mineral fertilizers and represents an environmentally and agronomically sound management strategy.
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Navarro Nateras, Lourdes, Aldo Zaul Zuñiga Álvarez, Jannu Casanova-Moreno, Goldie Oza, J. ledesma-García, Ricardo Escalona-Villalpando e Luis Arriaga. "Electrochemical and Optical Detection of Plant DNA for Sex Determination in a Lab-on-Chip Prototype". ECS Meeting Abstracts MA2022-01, n. 53 (7 luglio 2022): 2205. http://dx.doi.org/10.1149/ma2022-01532205mtgabs.
Testo completoAbstract (sommario):
INTRODUCTION The fruit industry employs millions of hectares for production; of these, a significant percentage uses only female or hermaphrodite plants. The selection is carried out by morphological analysis until blooming, which represents an inefficient use of resources. Typically, well-equipped laboratories and trained personnel are required to perform DNA analysis and give valid results1,2. Devices capable of generating this information within a short timespan could contribute to a fast and effective selection of productive plants. Nonetheless, it is necessary to have high sensitivity to differentiate between samples. The objective of this work is the development of an electrochemical and an optical detection system, with high sensitivity and repeatability. With the aim to incorporate the best option in a fully integrated device that ensures an easy-to-use product, safeguarding the correct use by non-trained operators and reducing the time to obtain a result. MATERIALS AND METHODS To evaluate the detection systems a random sequence of DNA (5’-TAGTCGTCAATCCTCCGCTT) was used (50 – 540 ng/µL). The electrochemical detection design is composed by three electrodes (WE-Au, AE-Au, RE-Ag|AgCl) and 0.5 M Ru(NH3)6Cl3 as a DNA intercalating agent3 in 40 mM TAE buffer. Three electrochemical techniques (SWV, DPV and CV) were compared (Bio Logic potentiostat). The optical detection system is composed of a phototransistor (Max. Sens. @ 550 nm), a filter (520 nm) and a LED (Max. WL peak @ 455 nm) to detect the fluorescent DNA intercalator SYBRgreen. Different concentrations of fluorescein (0.005 – 10 µM) were used to evaluate the system capabilities. The system was evaluated with the DNA sequence and SYBRgreen, then compared with a fluorescence microscope (Nikon Eclipse Ti-U). Finally, both systems were tested with plant DNA samples. Genomic material was extracted (CTAB protocol4) form 6 plants (3 female/3 hermaphrodite), amplified by PCR (Thermal cycler miniPCR Amplyus) and analyzed by electrophoresis. RESULTS With the electrochemical detection system, we observed a proportional decrease in the Ru(NH3)6Cl3 signal as the DNA concentration increases, as expected. The data analysis demonstrated that SWV was the most sensitive technique with a R2=0.980, LOD 30.968 ng/µL and LOQ 103.226 ng/µL. Results showed that female plants present an average current of 1.774 μA while hermaphrodite plants had 1.694 μA, allowing us to differentiate hermaphrodite plants accurately with a 90 % confidence interval. On the other hand, in the optical detection system with a R2=0.9568, LOD 2.12 ng/µL and LOQ 7.06 ng/µL, we observed an increase in the signal as de DNA concentration increases. When the optical analysis was compared with the fluorescence microscope results, we observed a similar trend in the signals with a R2=0.995, that validate the functionality of our system. However, the difference between plant samples was detected with only the 70 % confidence interval, female samples showed an average signal of 381 mV while hermaphrodite plants had 352.56 mV. CONCLUSIONS Plant DNA detection was evaluated through two different systems. The optical detection system showed more sensitivity with synthetic samples. However, in the evaluation of plant samples, the electrochemical system is less susceptible to interferences. Therefore, we can differentiate between female and hermaphrodite plants with a 90 % confidence interval. In this way, it represents the best option to evaluate a lab-on-a-chip device. REFERENCES Barrantes-Santamaría W, Loría-Quirós C, Gómez-Alpízar L. Evaluation of two-sex determining systems in papaya plants (Carica papaya) Pococí hybrid. Agron Mesoamerican. 2019;30(2):437-446. doi:10.15517/am.v30i1.34916 Cornelis S. FORENSIC LAB-ON-A-CHIP DNA ANALYSIS. 2019. Li LY, Jia HN, Yu HJ, et al. Synthesis, characterization, and DNA-binding studies of ruthenium complexes [Ru(tpy)(ptn)] 2 + and Ru(dmtpy)(ptn)] 2 +. J Inorg Biochem. 2012;113:31-39. doi:10.1016/j.jinorgbio.2012.03.008 Biosciences. CTAB extraction solution for genomic DNA extraction. Biosciences. 2016:3-7. Figure 1