To see the other types of publications on this topic, follow the link: Capacity factor (CF).
Journal articles on the topic 'Capacity factor (CF)'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Capacity factor (CF).'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Jung, Christopher, and Dirk Schindler. "Reasons for the Recent Onshore Wind Capacity Factor Increase." Energies 16, no. 14 (July 14, 2023): 5390. http://dx.doi.org/10.3390/en16145390.
Full textAbstract:
Increasing wind capacity and capacity factors (CF) are essential for achieving the goals set by the Paris Climate Agreement. From 2010–2012 to 2018–2020, the 3-year mean CF of the global onshore wind turbine fleet rose from 0.22 to 0.25. Wind turbine siting, wind turbine technology, hub height, and curtailed wind energy are well-known CF drivers. However, the extent of these drivers for CF is unknown. Thus, the goal is to quantify the shares of the four drivers in CF development in Germany as a case. Newly developed national power curves from high-resolution wind speed models and hourly energy market data are the basis for the study. We created four scenarios, each with one driver kept constant at the 2010–2012 level, in order to quantify the share of a driver for CF change between 2010–2012 and 2019–2021. The results indicated that rising hub heights increased CF by 10.4%. Improved wind turbine technology caused 7.3% higher CF. However, the absolute CF increase amounted to only 11.9%. It is because less favorable wind turbine sites and curtailment in the later period moderated the CF increase by 2.1% and 3.6%, respectively. The drivers are mainly responsible for perennial CF development. In contrast, variations in wind resource availability drive the enormous CF inter-annual variability. No multi-year wind resource change was detected.
2
Albadi, MH, and EF El-Saadany. "Comparative Study on Impacts of Power Curve Model on Capacity Factor Estimation of Pitch-Regulated Turbines." Journal of Engineering Research [TJER] 9, no. 2 (December 1, 2012): 36. http://dx.doi.org/10.24200/tjer.vol9iss2pp36-45.
Full textAbstract:
The amount of energy produced by a turbine depends on the characteristics of both wind speed at the site under investigation and the turbine's power performance curve. The capacity factor (CF) of a wind turbine is commonly used to estimate the turbine's average energy production. This paper investigates the effect of the accuracy of the power curve model on CF estimation. The study considers three CF models. The first CF model is based on a power curve model that underestimates the turbine output throughout the ascending segment of the power curve. To compensate for the aforementioned discrepancy, the Weibull parameters, c and k, which are used to describe wind profile, are calculated based on cubic mean wind speed (CMWS). The second CF model is based on the most accurate generic power curve model available in open literature. The third CF model is based on a new model of power performance curve which mimics the behavior of a typical pitch-regulated turbine curve. As the coefficients of this power curve model are based on a general estimation of the turbine output at different wind speeds, they can be further tuned to provide a more accurate fit with turbine data from a certain manufacturer.
3
Perdana, Ery, Sulardjaka, and Budi Warsito. "Modeling of Capacity Factor in Rembang Coal-Fired Steam Power Plant Using Regression Modelin." International Research Journal of Innovations in Engineering and Technology 08, no. 03 (2024): 51–56. http://dx.doi.org/10.47001/irjiet/2024.804006.
Full textAbstract:
Coal-Fired Steam Power Plant (PLTU) Rembang is an important power plant in the Central Java electricity system. Like other coal-fired steam power plants, fuel cost is the most significant expense when operating the PLTU Rembang. During the 2019-2021 period, the average fuel cost was 73.88% of total costs. One of the ways to reduce fuel costs is by improving the accuracy of fuel demand planning. Fuel procurement planning is very dependent on the projected amount of electricity sales from power plant, which is largely determined by the power plant's Capacity Factor (CF). However, PLTU Rembang does not have any CF prediction modeling. This research developed and compared four prediction models: random forest regression, support vector regression, multiple polynomial regression, and multiple linear regression. Based on the comparison of validation from the four prediction model with MAPE and R-squared parameters, the multiple linear regression models is the best model, with the lowest MAPE of 7.83% and the highest R-squared of 0.8814. This multiple linear regression model can be used to predict the CF of PLTU Rembang in the future so that fuel demand planning is more accurate.
4
Janon, Akraphon, Tanakorn Wongwuttanasatian, Gumphol Faikaow, and Panumas Srinor. "An Investigation of the Low Performance of the First Wind Farm in Thailand: A Case of Poor Wind Turbine-Site Matching." Advanced Materials Research 724-725 (August 2013): 469–75. http://dx.doi.org/10.4028/www.scientific.net/amr.724-725.469.
Full textAbstract:
This research investigates causes of the low performance of the first commercial wind farm in Thailand. The measured data suggests that this wind farm is uncompetitive. We found that this is due to poor turbine-site matching. In contrary to a traditionally held belief, the hub-height and turbine capacity are not the contributing factors. Key performance indicators are obtained for use as benchmarks in future wind farm appraisal. Then a turbine selection method is proposed to increase the capacity factor (CF) of the wind farm. CF is used as the main performance indicator, which can be compared to other wind farms. The real capacity factor (CFR) determined using measured data is 14.90%. This CFR is considerably lower than the estimated capacity factor (CFE) of 21.53%. The low CFR is due to grid instability. In addition, the CFR is lower than the CFE by a factor of 0.69. This information is valuable to investors and wind farm developers in a wind farm feasibility study. A graphical wind turbine-site matching is proposed. Wind turbine-site matching is achieved by using normalised power output plots and power density plots on a probability density graph of the wind site. This process consumes a short period of time. An improved turbine-site matching is achieved.
5
Indriyono, Bonifacius Vicky, Moch Sjamsul Hidajat, Tri Esti Rahayuningtyas, Zudha Pratama, Iffah Irdinawati, and Evita Citra Yustiqomah. "Expert System for Detecting Diseases of Potatoes of Granola Varieties Using Certainty Factor Method." International Journal of Artificial Intelligence & Robotics (IJAIR) 4, no. 2 (December 3, 2022): 70–77. http://dx.doi.org/10.25139/ijair.v4i2.5312.
Full textAbstract:
The low productivity of potatoes is caused by many factors, including the very low quality of the seeds used, poor storage, climate, capital, limited farmer knowledge, and attacks by plant-disturbing organisms, especially diseases. Not only that, many farmers are still unfamiliar with the various diseases that can attack potato plants, or their knowledge about potato plant diseases is incomplete. This study aims to design and develop an expert system web-based application technology using the Certainty Factor (CF) method to detect potato disease symptoms. The CF method defines a measure of the capacity of a fact or provision to express the level of an expert's belief in a matter experienced by the concept of belief or trust and distrust or uncertainty contained in the certainty factor. The results showed that the CF method could function optimally in detecting potato plant diseases which can help farmers based on the symptoms that appear with an accuracy value of 94%.
6
Million, Jeff B., and Thomas H. Yeager. "Capture of Sprinkler Irrigation Water by Container-grown Ornamental Plants." HortScience 50, no. 3 (March 2015): 442–46. http://dx.doi.org/10.21273/hortsci.50.3.442.
Full textAbstract:
The capacity for container-grown plants to capture sprinkler irrigation water plays a critical role in adjusting irrigation rates to deliver required amounts of water to the container substrate. The capture factor (CF) used to describe this capacity was defined as the amount of water captured with a plant relative to the amount captured without a plant. A wind-sheltered, irrigation test area was established to measure CF as affected by plant species, plant size, container size, container spacing, and sprinkler type. CF values for 11 marketable-sized, commonly grown plant species ranged from 1 to 4 with highest values exhibited by plant species with an upright, spreading growth habit. CF values increased as plant size increased. Close container spacings (less than one container diameter between adjacent containers) reduced CF when the allotted area outside the container limited the potential amount of water that could be captured. Compared with impact sprinklers, wobbler sprinklers increased irrigation capture 7% for Ligustrum japonicum grown in 27-cm-diameter containers but not in 16-cm-diameter containers. Results showed that CF is a dynamic parameter that depends on canopy size, container size, container spacing, and sprinkler type. A working knowledge of CF is crucial for determining irrigation requirements to maximize sprinkler irrigation efficiency in container nurseries.
7
Kurniawan, Aries Taufiq, Arief Budiman, Rachmawan Budiarto, and Ridwan Budi Prasetyo. "Optimizing Energy Output for Oscillating Water Column (OWC) Wave Energy Converter System at Pantai Baron, Gunung Kidul, DI Yogyakarta." Applied Engineering and Technology 3, no. 2 (August 26, 2024): 125–32. https://doi.org/10.31763/aet.v3i2.1773.
Full textAbstract:
The prototypes of the Oscillating Water Column (OWC) system constructed by BPPT at Pantai Baron, Gunung Kidul, in 2005 and 2006 were not sustainable. Based on its condition and location, the root cause of the problem was defined. Maximizing the total efficiency and capacity factor (Cf) of the OWC system was the main factor for optimizing energy output. Collecting factors that constructed the total efficiency and capacity factor of the OWC system was conducted. Selecting the appropriate turbine, generator, and chamber system led to an increase in the total efficiency of the OWC system. Reducing the effect of wave diffraction, finding optimum wave data for forecasting, finding optimum water depth area to avoid wave breaking area, reducing corrosion chance by selecting the optimum height of the OWC system, and using a control system to minimize stalling on turbine were factors that constructed capacity factor
8
Barthelmie, R. J., G. C. Larsen, M. Mølgaard Pedersen, and S. C. Pryor. "Microscale modelling of wind turbines in the New York offshore lease area." Journal of Physics: Conference Series 2265, no. 2 (May 1, 2022): 022040. http://dx.doi.org/10.1088/1742-6596/2265/2/022040.
Full textAbstract:
Abstract Simulations of the New York offshore wind energy lease area are undertaken within the PyWake program using both NOJ wake parameterization and the Fuga model. Seven different wind farm layouts are simulated to evaluate how the potential annual energy production (AEP) and capacity factor (CF) are impacted by the installed capacity (IC) density and the rotation of the wind turbines compared to the control. The control simulations use the east-west, north-south turbine layout with equidistant spacing of 1.85 km (7.7D) that will be used for the Vineyard Wind offshore wind farm south of Massachusetts. Both CF and AEP have an almost linear relationship with IC for the IC densities of 2.2 to 8.1 MWkm−2. Modelled CF are lower using Fuga (48.9% to 53.9%) than from NOJ (51.5% to 54.4%). The rotated turbine layouts have similar CF to the control because the wind direction distribution is dominated by peaks in both the southwest and northwest directions.
9
Bystrova, Serafima G. "Features of determining the diffusion capacity of the lungs by carbon monoxide in cystic fibrosis children." Russian Pediatric Journal 25, no. 5 (October 30, 2022): 350–56. http://dx.doi.org/10.46563/1560-9561-2022-25-5-350-356.
Full textAbstract:
The article presents current literature data from English-language (search made in PubMed) and Russian-language (search made in eLibrary) sources about the method for measurement of the lung diffusing capacity for carbon monoxide in children with cystic fibrosis (CF). This review presents the general characteristics of this test in children and adults with various diseases, and also describes the conflicting results of studies using this method in CF patients of various ages and disease severity. The expediency, the informativeness, and difficulties of evaluation and interpretation of the test’s results, depending on the age and course of the disease of patients, are discussed. The author concludes that further research of interpretation of indicators determined during the test of the lung diffusing capacity for carbon monoxide, such as the transfer factor, alveolar volume, and their ratio in CF children is necessary.
10
WIJAYA, FRANSISCO DANANG, I. WAYAN ADIYASA, and EKRAR WINATA. "Analisis Faktor Kapasitas Pembangkit Listrik Hibrida PLTB dengan PLTD di Pulau Terpencil: Studi Kasus Elat Pulau Serau Maluku." ELKOMIKA: Jurnal Teknik Energi Elektrik, Teknik Telekomunikasi, & Teknik Elektronika 9, no. 4 (October 10, 2021): 746. http://dx.doi.org/10.26760/elkomika.v9i4.746.
Full textAbstract:
ABSTRAKRasio elektrifikasi di Indonesia belum mencapai 100%, penyebabnya antara lain masalah lokasi di daerah terpencil atau kepulauan dan mahalnya biaya operasi PLTD. Salah satu solusi adalah membangkitkan listrik berbasis energi terbarukan setempat. Tahap awal pemanfaatan energi terbarukan perlu dihitung faktor kapasitas (CF). Tujuan penelitian ini menganalisis CF untuk PLTB dengan metode perhitungan analitik berbasis potensi energi angin, spesifikasi teknologi PLTB dan PLTD, profil beban dan energi listrik yang dapat diproduksi untuk pengembangan sistem hibrida dengan mengambil kasus di Elat Pulau Serau Maluku. Hasil perhitungan CF untuk 5 teknologi PLTB yang berbeda dengan variasi ketinggian di Elat telah diverifikasi dengan simulasi menggunakan perangkat lunak HOMER dengan nilai rerata galat -0,030. Semakin tinggi PLTB, nilai CF semakin besar dengan konstanta 0,0030.Kata kunci: elektrifikasi, faktor kapasitas, PLTB, PLTD, sistem hibrida ABSTRACTThe electrification ratio in Indonesia has not reached 100%, the causes include problems with the location in remote areas or islands and the high operating costs of diesel power plant (DPP). One solution is to generate electricity based on local renewable energy. The initial stage of utilizing renewable energy needs to calculate the capacity factor (CF). The purpose of this research is to analyze CF for wind turbine generator (WTG) with analytical calculation methods based on wind energy potential, technology specifications of WTG and DPP, load profiles and electrical energy that can be produced for hybrid system development by taking the case in Elat Serau Island, Maluku. The results of CF calculations for 5 different WTG technologies with altitude variations in Elat have been verified by simulation using HOMER software with a mean error value of -0.030. The higher the WTG, the greater the CF value with a constant of 0.0030.Keywords: electrification, capacity factor, diesel power plant, wind turbine generator, hybrid system
11
Olczak, Piotr, and Tomasz Surma. "Energy Productivity Potential of Offshore Wind in Poland and Cooperation with Onshore Wind Farm." Applied Sciences 13, no. 7 (March 27, 2023): 4258. http://dx.doi.org/10.3390/app13074258.
Full textAbstract:
Wind power is the leader in electricity production among the standing RES technologies, both in Poland and in Europe/World. In Poland, so far there are only onshore wind turbines. Their dynamic increase in installed capacity has been observed, especially between 2011 and 2017. This study analyzed the impact of offshore wind energy on the ability of the Polish power system to meet power demands. For this purpose, methods of statistical analysis (of existing onshore and planned offshore technologies) for the determination of wind turbine productivity based on wind speed components data from the ERA5 service were used. For onshore wind turbines, the value of the capacity factor CF(P) in Poland was 25.5% in 2021 and 30.1% in 2022. As a result of the simulation, it was calculated that for the planned offshore wind farms, the capacity factor CF(B) would be 55.6% under 2022 wind speed conditions. The 2022 peak load demands in the Polish system were also analyzed. The quantitative impact of installing 6 GW of offshore wind turbine capacity on the national power system was also identified.
12
Barwood, Martin J., Joe Kupusarevic, and Stuart Goodall. "Enhancement of Exercise Capacity in the Heat With Repeated Menthol-Spray Application." International Journal of Sports Physiology and Performance 14, no. 5 (May 1, 2019): 644–49. http://dx.doi.org/10.1123/ijspp.2018-0561.
Full textAbstract:
Purpose: Exercise performance is impaired in the heat, and a contributing factor to this decrement is thermal discomfort. Menthol spraying of skin is one means of alleviating thermal discomfort but has yet to be shown to be ergogenic using single-spray applications. The authors examined whether repeated menthol spraying could relieve thermal discomfort, reduce perception of exertion, and improve exercise performance in hot (35°C), dry (22% relative humidity) conditions, hypothesizing that it would. Methods: A total of 8 trained cyclists completed 2 separate conditions of fixed-intensity cycling (50% maximal power output) for 45 min before a test to exhaustion (TTE; 70% maximal power output) with 100 mL of menthol spray (0.20% menthol) or control spray applied to the torso after 20 and 40 min. Perceptual (thermal sensation, thermal comfort, and rating of perceived exertion) performance (TTE duration), thermal variables (skin temperature, rectal temperature, and cardiac frequency), and sweating were measured. Data were compared using analysis of variance to .05 alpha level. Results: Menthol spray improved thermal sensation (cold sensation cf warm/hot after first spraying; P = .008) but only descriptively altered thermal comfort (comfortable cf uncomfortable; P = .173). Sweat production (994 [380] mL cf 1180 [380] mL; P = .020) and sweat rate (827 [327] mL·h−1 cf 941 [319] mL·h−1; P = .048) lowered. TTE performance improved (4.6 [1.74] cf 2.4 [1.55] min; P = .004). Menthol-spray effects diminished despite repeated applications, indicating increased contribution of visceral thermoreceptors to thermal perception. Conclusion: Repeated menthol spraying improves exercise capacity but alters thermoregulation, potentially conflicting behavioral and thermoregulatory drivers; care should be taken with its use. Carrying and deploying menthol spray would impose a logistical burden that needs consideration against performance benefit.
13
Asri, Novena Damar, and Purnomo Yusgiantoro. "Is sustainability challenging in Indonesia’s energy provision? Fuel type vs. externalities in electricity cost analysis." Sustinere: Journal of Environment and Sustainability 5, no. 2 (August 31, 2021): 103–32. http://dx.doi.org/10.22515/sustinere.jes.v5i2.154.
Full textAbstract:
This study aims to reveal the challenging sustainability within Indonesia’s energy provision by studying the electricity generating cost (GC) formation, externalities’ effect, and current Indonesia’s electricity and budget condition. In studying GC formation, two variables thought to have remarkable influence are fuel price (represented by Fuel Cost/FC) and operating time, which indicates the power plant’s type (represented by Capacity Factor/CF). The regression results indicate that CF has a greater impact on GC than FC; GC increases as FC increases but decreases as CF increases. FC contributes by 10%-86% of GC, subject to fuel prices and CF. Since coal is the cheapest, GCCoal < GCGas < GCDiesel, but internalizing the externalities triples the GCCoal and doubles the GCDiesel. However, its internalization is challenging as it affects the producers’ and consumers’ welfare. Sustainable energy provision is challenging due to two factors. First, there is a dilemma between applying sustainability principles and providing energy immediately. The fastest route, which is the lowest price orientation, is preferable, indicated by coal domination in the electricity mix. Second, sustainability is not the priority yet, indicated by the environment programs is outside the top ten priority development programs.
14
Abdul Rahim, Yang Ilya Akila, Hedzlin Zainuddin, Eko Adhi Setiawan, Alfian Ferdiansyah Madsuha, Mohamad Zhafran Hussin, Shahril Irwan Sulaiman, and Siti Nor Nadhirah Ibrahim. "Performance of grid-connected photovoltaic systems in Northern and Southern Hemispheres under equatorial climate." International Journal of Power Electronics and Drive Systems (IJPEDS) 15, no. 2 (June 1, 2024): 858. http://dx.doi.org/10.11591/ijpeds.v15.i2.pp858-873.
Full textAbstract:
This work studied the actual and simulated technical performance between two grid-connected photovoltaic (GCPV) systems representing opposite latitudes. The system with a capacity of 5.4 kWp installed in Kelantan, Malaysia represents the northern equator, and the 183.6 kWp system installed in Cikarang, Indonesia, denotes the southern equator. The performance was simulated using PVsyst software, which included the energy output (E_outt), reference yield (Y_r), final yield 〖(Y〗_f), performance ratio (PR), and capacity factor (CF). The mean bias error (MBE) between the actual and simulated technical performance were as follows; for system A, the yearly MBE for the E_out, Y_r, Y_f, PR, and CF were -0.4%, 17.1%, -1.4%, -15.8%, and 1.4%, respectively, and for system B, the E_out, Y_r, 〖 Y〗_f, PR, and CF values were 9.80%, 18.3%, 10.0%, -7.2%, and 10.0% respectively. The results have proven that PVsyst has successfully simulated the yearly E_out, 〖 Y〗_f and CF for both systems including PR, for system B, with MBE less than 10%. However, it is noteworthy to highlight that PVsyst significantly overestimated the Y_r of both systems up to 18.3% and conversely underestimated the PR for system A by 15.8%, which highly likely caused by the Meteonorm imported weather data.
15
Yan, Mengting, Weihong Jia, Yawen Yang, Qi Zhou, Limin Ma, and Jinqing Wang. "Preparation and Heat Dissipation Performance of Vertical Graphene Nanosheets/Carbon Fibers Composite Film." Coatings 13, no. 2 (February 10, 2023): 407. http://dx.doi.org/10.3390/coatings13020407.
Full textAbstract:
High-efficient heat dissipation materials are urgently required in advanced electronic packaging technology because effectively releasing the internal heat flow density of electronic devices is a key factor during their operation. In this work, a novel vertical graphene nanosheets/carbon fibers (VGNs/CF) composite film, with a vertically oriented structure and excellent heat dissipation properties, is fabricated on the stainless steel substrate by a facile thermochemical growth method. The preparation of composite film is green, safe, and highly efficient. CF is used as a thermally conductive filler to provide thermal conductivity channels for VGNs, and both of them construct a continuous thermally conductive network. The through-plane thermal conductivity of the VGNs/CF composite film could reach 17.7 W/(m·K), and the addition of CF significantly improved the heat dissipation performance of the composite film compared with the pure VGNs film (13.9 W/(m·K)). Conclusively, the simple preparation method and outstanding thermal conductivity capacity of the VGNs/CF composite film are expected to meet the application requirements of the electronics industry.
16
Lands, Larry, Raezelle Zinman, Melvin Wise, and Hinda Kopelman. "Pancreatic Function Testing in Meconium Disease in CF." Journal of Pediatric Gastroenterology and Nutrition 7, no. 2 (March 1988): 276–79. http://dx.doi.org/10.1002/j.1536-4801.1988.tb09517.x.
Full textAbstract:
SummaryWe report two infants with cystic fibrosis (CF), presenting with meconium ileus and meconium plug, who had no clinical or biochemical evidence of pancreatic insufficiency during infancy. They underwent pancreatic secretory function testing at 11 and 9 months of age, respectively. Both patients had sufficient lipase and colipase secretion to maintain normal digestion of fat, confirming that meconium disease in CF does not necessarily imply pancreatic insufficiency and the need for enzyme supplementation in infancy. Nonetheless, we documented markedly reduced enzyme secretion in both patients, implying a potential role for the pancreas in the pathogenesis of meconium disease, even when clinical pancreatic insufficiency is absent. In addition, our patient with meconium ileus had a severely limited fluid secretory capacity (10.3% of mean normal values). In contrast, the patient with the milder presentation of meconium plug had a far greater ability to secrete fluid (75% of mean normal), but had poorer pancreatic proteolytic activity. We suggest that impaired fluid secretion may be a very significant factor in the pathogenesis of meconium ileus, and we speculate that an inability to maintain sufficient intraluminal fluid relative to the degree of pancreatic proteolytic deficiency may more adequately explain the risk of occurrence and the severity of intestinal obstruction in CF than either factor alone.
17
Dittrich, A. Susanne, Iris Kühbandner, Stefanie Gehrig, Verena Rickert-Zacharias, Matthew Twigg, Sabine Wege, Clifford C. Taggart, Felix Herth, Carsten Schultz, and Marcus A. Mall. "Elastase activity on sputum neutrophils correlates with severity of lung disease in cystic fibrosis." European Respiratory Journal 51, no. 3 (March 2018): 1701910. http://dx.doi.org/10.1183/13993003.01910-2017.
Full textAbstract:
Neutrophil elastase (NE) is a key risk factor for severity of cystic fibrosis (CF) lung disease. Recent studies identified increased NE activity on the surface of airway neutrophils from CF-like mice and patients with CF. However, the role of surface-bound NE in CF lung disease remains unknown. We determined the relationship between surface-bound NE activity and severity of lung disease in CF.Surface-bound NE activity was measured on sputum neutrophils from 35 CF patients and eight healthy controls using novel lipidated Förster resonance energy transfer reporters and correlated with free NE activity, neutrophil counts, interleukin-8, myeloperoxidase and antiproteases in sputum supernatant, and with lung function parameters.Surface-bound NE activity was increased in CF compared to healthy controls (p<0.01) and correlated with free NE activity (p<0.05) and other inflammation markers (p<0.001). Surface-bound and free NE activity correlated with forced expiratory volume in 1 s % predicted (p<0.01 and p<0.05), but only surface-bound NE activity correlated with plethysmographic functional residual capacity % pred (p<0.01) in patients with CF.We demonstrate that surface-bound NE activity on airway neutrophils correlates with severity of lung disease in patients with CF. Our results suggest that surface-bound NE activity may play an important role in the pathogenesis and serve as novel biomarker in CF lung disease.
18
Maillé, Emilie, Nguyen Thu Ngan Trinh, Anik Privé, Claudia Bilodeau, Élyse Bissonnette, Nathalie Grandvaux, and Emmanuelle Brochiero. "Regulation of normal and cystic fibrosis airway epithelial repair processes by TNF-α after injury." American Journal of Physiology-Lung Cellular and Molecular Physiology 301, no. 6 (December 2011): L945—L955. http://dx.doi.org/10.1152/ajplung.00149.2011.
Full textAbstract:
Chronic infection and inflammation have been associated with progressive airway epithelial damage in patients with cystic fibrosis (CF). However, the effect of inflammatory products on the repair capacity of respiratory epithelia is unclear. Our objective was to study the regulation of repair mechanisms by tumor necrosis factor-α (TNF-α), a major component of inflammation in CF, in a model of mechanical wounding, in two bronchial cell lines, non-CF NuLi and CF CuFi. We observed that TNF-α enhanced the NuLi and CuFi repair rates. Chronic exposure (24–48 h) to TNF-α augmented this stimulation as well as the migration rate during repair. The cellular mechanisms involved in this stimulation were then evaluated. First, we discerned that TNF-α induced metalloproteinase-9 release, epidermal growth factor (EGF) shedding, and subsequent EGF receptor transactivation. Second, TNF-α-induced stimulation of the NuLi and CuFi wound-closure rates was prevented by GM6001 (metalloproteinase inhibitor), EGF antibody (to titrate secreted EGF), and EGF receptor tyrosine kinase inhibitors. Furthermore, we recently reported a relationship between the EGF response and K+channel function, both controlling bronchial repair. We now show that TNF-α enhances KvLQT1 and KATPcurrents, while their inhibition abolishes TNF-α-induced repair stimulation. These results indicate that the effect of TNF-α is mediated, at least in part, through EGF receptor transactivation and K+channel stimulation. In contrast, cell proliferation during repair was slowed by TNF-α, suggesting that TNF-α could exert contrasting actions on repair mechanisms of CF airway epithelia. Finally, the stimulatory effect of TNF-α on airway wound repair was confirmed on primary airway epithelial cells, from non-CF and CF patients.
19
Musa, La Ode, Abdul Rahman, Andi Ardiansyah, and Hairuddin Hairuddin. "PENGARUH PERUBAHAN ELEVASI (HEAD) DAN KUOTA PEMAKAIAN AIR DAM BILIBILI TERHADAP UNJUK KERJA TURBIN AIR PADA PLTA BILIBILI." Jurnal Teknik Mesin Sinergi 14, no. 2 (May 26, 2019): 149–61. http://dx.doi.org/10.31963/sinergi.v14i2.1170.
Full textAbstract:
Penelitian ini bertujuan untuk mengetahui unjuk kerja Turbin Air PLTA Bilibili dengan indikator yaitu Efesiensi dan Capacity Factor (CF). Metode yang digunakan adalah pengambilan data Kuota air atau debit (Q), Head (H) dan Daya keluaran Generator kemudian dilakukan analisa data. Periode pengambilan data dari bulan Juni 2014 sampai dengan Juni 2015. Selama periode pengambilan data, debit tertinggi 45 m3/s dan terendah 6,4 m3/s sedangkan nilai elevasi tertinggi 99,4 mdpl dan terendah 85,8 mdpl. Efesiensi Turbin #1 berada diantara 0,669% sampai dengan 0,881% dan untuk #2 diantara 0,678% sampai dengan 0,916%. Indikator Capacity Factor, #1 berada pada nilai 6,8% sampai dengan 98% dan #2 berada pada nilai 7,7% sampai dengan 100%. Capacity Factor untuk PLTA Bilibili secara kumulatif adalah 53,81%. Sehingga adanya batasan operasional yaitu penentuan kuota pemakaian air untuk PLTA Bilibili, berdampak pada unjuk kerja Turbin khususnya untuk efisiensi Turbin.
20
Bang, SungSig, and SangYun Park. "Effect of Depreciation Method for Long-Term Tangible Assets on Sustainable Management: From a Nuclear Power Generation Cost Perspective under the Nuclear Phase-Out Policy." Sustainability 13, no. 9 (May 8, 2021): 5270. http://dx.doi.org/10.3390/su13095270.
Full textAbstract:
The Korean Government has been implementing a nuclear phase-out policy since 2017. Nuclear power plants accounted for 30.0% of the total power generation in 2016; this figure fell to 25.9% at the end of 2019, and the average Capacity Factor (CF) of a nuclear power plant approximately dropped from 89.1% to 69.2%. The nuclear phase-out policy presents severe consequences for the sustainable management of the nuclear power industry. Accordingly, the purpose of this study is to analyze the effect of a decrease in the nuclear capacity factor under the nuclear phase-out policy on the depreciation cost per unit using the Straight-Line Method (SLM) and Decelerated Depreciation Method (DDM) and to provide recommendations from a sustainable management perspective. The results show that the decrease in CF of nuclear power plants has a negative impact on sustainable development of the nuclear power industry. DDM is more beneficial than the SLM during this initial stage of depreciation under the nuclear phase-out policy. In addition, in the early stages of projects or immediately after attracting large-scale investments, DDM can offer more positive signs for stockholders by calculating a smaller net loss or a higher net profit.
21
Mishra, Abha. "Intermittent Irrigation Enhances Morphological and Physiological Efficiency of Rice Plants." Agriculture (Pol'nohospodárstvo) 58, no. 4 (December 1, 2012): 121–30. http://dx.doi.org/10.2478/v10207-012-0013-8.
Full textAbstract:
Abstract The response of rice roots and shoots and their causal relationships affecting yield under varying soil water condition are important related subjects of research. To understand the mechanism of response, studies were conducted using four water treatments: a) intermittent flooding through the vegetative stage (IF-V); b) intermittent flooding extended into the reproductive stage (IF-R); c) no standing water (NSW), maintaining soil at field capacity; and d) continuous flooding (CF) condition at the Asian Institute of Technology in Thailand. It was observed that the senescence of lower leaf and flag leaf was delayed under IF-V compared to CF water condition. This delay was associated with higher root oxidizing activity (ROA) rate (50% higher than CF), higher root length density (RLD) (52% higher than CF), higher biomass production (14% higher than CF) along with higher grain yield (25% higher than CF). The plants grown under NSW conditions had better growth at later growth stage and better yield performance compared to IF-R because of higher nitrogen availability and higher uptake rate under NSW water conditions (73% higher N uptake). However, under CF water condition the nitrogen availability was not a limiting factor but due to decreased root activity rate the dry matter production and grain yield significantly reduced compared to IF-V water condition. The results suggested that ROA and RLD are linked to shoot response and to dry matter production. A better understanding of the underlying mechanisms should assist in achieving improvements in crop productivity through improved crop management practices in water-limiting environment.
22
Tan, Wen Xue, Hua Rui Wu, and Xi Ping Wang. "Artificial Intelligent Diagnosing Method Based on the Certainty-Speculated Reason of Pivot Factor." Advanced Materials Research 846-847 (November 2013): 56–60. http://dx.doi.org/10.4028/www.scientific.net/amr.846-847.56.
Full textAbstract:
How to solve disease-diagnosing problem effectively by the aid of Artificial Intelligence Computer has been being a mainstream of Intelligent System researching and development. Heretofore, performance of the well-known native Uncertainty Reason Resolution method still is unsatisfactory to professionals. This paper pioneers the concept of Associative-Pivot Factor and its Certainty Index Speculation algorithm, and on this base designs A novelty Machine Diagnosing Algorithm based on the Certainty Reason of Associative-Pivot Factor. Results and analysis demonstrate that the method exhibit a better efficiency than man-expert individual and the native CF Method. Generally speaking, it manifests an accurate rate of diagnosis over 82% and possesses the capacity to expand diagnosing capability of man-expert.
23
Leger Monteiro, Wilson Madaleno, and António Sarmento. "Analysing the Possibility of Extracting Energy from Ocean Waves in Cabo-Verde to Produce Clean Electricity - Case-Study: the Leeward Islands." International Journal of Renewable Energy Development 8, no. 1 (February 2, 2019): 103. http://dx.doi.org/10.14710/ijred.8.1.103-112.
Full textAbstract:
This work analyses the possibility of extracting energy from the ocean waves around the Leeward Islands of Cabo-Verde. This study was based on 31 years of wave and wind data, obtained through the SOWFIA - Streamlining of Ocean Wave Farm Impact Assessment, at 16° N-24° W. Then, the SWAN - Simulating Waves Nearshores - was used to perform the wave transformations to the shore. As the number of waves is very high, the cluster analysis and the Non-Parametric Wilcoxon Test were used to reduce the computing time by SWAN. The results pointed to the South of these islands and the East Coast of Maio island as the best locations for wave energy extraction. The use of the power matrix of some commercial devices that are available, such as Wave Dragon (7 MW), Pelamis (750 kW) and AquaBuoy (250 kW), allowed to estimate the best devices scale factors that leads to their best Capacity Factor (CF), at the target regions. Thus, the Wave Dragon is the most indicated device (CF=71%), at the scale of 0.3, followed by AquaBuoy scaled by 0.4 (CF=57%) and Pelamis scaled by 0.5, with CF=26%. However, in a natural scale, AquaBuoy is the most efficient device (CF = 18.8%) in comparison to the Wave Dragon (CF=17%) and Pelamis (CF=15%). AquaBuoy presented the best cost-benefit ratio (C/B = 0.135 USD/kWh) followed by Wave Dragon (C/B= 0.235 USD/kWh) and Pelamis (C/B = 0.390 USD/kWh). The limitation of the number of Wave Energy Converters to implement the wave power plant affects negatively the cost of its investment.©2019. CBIORE-IJRED. All rights reservedArticle History: Received March 27th 2018; Received in revised form October 16th 2018; Accepted January 5th 2019; Available onlineHow to Cite This Article: Monteiro, W.M.L., and Sarmento, A (2019). Analysing the Possibility of Extracting Energy from Ocean Waves in Cabo-Verde to Produce Clean Electricity - Case-Study: The Leeward Islands. Int. Journal of Renewable Energy Development, 8(1), 103-112https://doi.org/10.14710/ijred.8.1.103-112
24
Xu, Gongxun, Meiqi He, Deying Zhao, Deguo Lyu, and Sijun Qin. "Physiological and Structural Changes in Apple Tree Branches of Different Varieties during Dormancy." Horticulturae 9, no. 8 (August 20, 2023): 947. http://dx.doi.org/10.3390/horticulturae9080947.
Full textAbstract:
Low temperature is an abiotic stress factor limiting the distribution of fruit tree cultivation areas. As temperate deciduous fruit trees, apple (Malus domestica) trees go dormant in the winter to adapt to or avoid damage caused by low temperatures. The capacity for cold resistance is closely linked to the physiological, biochemical, and structural characteristics of one-year-old branches. In this study, we investigated such changes in the branches of cold-resistant ‘Hanfu’ (HF) and cold-sensitive ‘Naganofuji 2’ (CF) apple varieties. The relative electrical conductivity, malondialdehyde content, and reactive oxygen species content of HF branches were lower than those of CF branches, while the antioxidant enzyme activity was higher in HF. The proline, soluble protein, and soluble sugar contents in both varieties showed an initial increase, followed by a subsequent decrease. Sucrose and sorbitol were the main sugar components, but sucrose and fructose were higher in HF than in CF. The periderm, phloem, and xylem of HF branches were also found to be thicker than those of CF branches, while the vessel diameter was smaller and the density greater. The results of this study provide a theoretical reference for further research on the low temperature adaptability of apple tree branches during dormancy.
25
Gojsina, Bojana, Milan Rodic, Jelena Visekruna, Goran Trajkovic, Aleksandar Sovtic, and Predrag Minic. "Pulmonary exacerbations as a risk factor for lung function decline-experiences of the National Cystic Fibrosis Center." Vojnosanitetski pregled 76, no. 11 (2019): 1110–14. http://dx.doi.org/10.2298/vsp171114005g.
Full textAbstract:
Background/Aim. Pulmonary exacerbations have negative impact on clinical course of cystic fibrosis (CF) lung disease being associated with a steeper decline in the lung function, unfavorable prognosis and impaired quality of life. The aim of this study was to determine whether an increased number of exacerbations had influence on the lung function in the patients with CF, as well as to estimate the nutritional status, gender, presence of comorbid conditions and bacterial colonization of airways as predictive factors for pulmonary exacerbations. Methods. This retrospective cohort study included 83 pediatric and adult patients, treated from 2011? 2015 in the Mother and Child Health Institute of Serbia ?Dr Vukan Cupic?. The best result of forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC) in each year of follow-up was taken into account to calculate the five-year trend values of these indicators. The number of exacerbations per year of follow-up and its impact on the FEV1 decline was evaluated. Results. Mean annual decline of FEV1 and FVC were 2.4% and 1.7% respectively. The malnourished patients had the lower initial values of FEV1 and FVC, and more frequent exacerbations in comparison with the normal weight and overweight patients. The frequency of exacerbations was significantly higher in the patients chronically colonized with Burkholderia cepacia (p = 0.023). The increased number of exacerbation was proved to be the most important factor in a prediction of FEV1 decline over time (p = 0.013). Conclusion. Pulmonary exacerbations lead to the more progressive lung function decline in the patients with CF. Malnourishment and chronic airway colonization with Burkholderia cepacia result in more frequent pulmonary exacerbations.
26
Barros Souza Riedel, Ana Beatriz, Vitor Feitosa Riedel, Hélio Nunes de Souza Filho, Ennio Peres da Silva, Renato Marques Cabral, Leandro de Brito Silva, and Alexandre de Castro Pereira. "Technical–Economic Analysis of Renewable Hydrogen Production from Solar Photovoltaic and Hydro Synergy in a Pilot Plant in Brazil." Energies 17, no. 17 (September 9, 2024): 4521. http://dx.doi.org/10.3390/en17174521.
Full textAbstract:
Renewable hydrogen obtained from renewable energy sources, especially when produced through water electrolysis, is gaining attention as a promising energy vector to deal with the challenges of climate change and the intermittent nature of renewable energy sources. In this context, this work analyzes a pilot plant that uses this technology, installed in the Itumbiara Hydropower Plant located between the states of Goiás and Minas Gerais, Brazil, from technical and economic perspectives. The plant utilizes an alkaline electrolyzer synergistically powered by solar photovoltaic and hydro sources. Cost data for 2019, when the equipment was purchased, and 2020–2023, when the plant began continuous operation, are considered. The economic analysis includes annualized capital, maintenance, and variable costs, which determines the levelized cost of hydrogen (LCOH). The results obtained for the pilot plant’s LCOH were USD 13.00 per kilogram of H2, with an efficiency loss of 2.65% for the two-year period. Sensitivity analysis identified the capacity factor (CF) as the main determinant of the LCOH. Even though the analysis specifically applies to the Itumbiara Hydropower Plant, the CF can be extrapolated to larger plants as it directly influences hydrogen production regardless of plant size or capacity.
27
Waewsak, Jompob, Chana Chancham, Somphol Chewamongkolkarn, Chuleerat Kongruang, and Yves Gagnon. "Technical and Economic Assessment of a 10 MW Wind Farm at Pakphanang District in Nakhon Si Thammarat Province." Applied Mechanics and Materials 839 (June 2016): 142–50. http://dx.doi.org/10.4028/www.scientific.net/amm.839.142.
Full textAbstract:
This paper presents the technical and economic assessment of a 10 MW wind farm at Pakphanang district in Nakhon Si Thammarat province, southern Thailand. The microscale wind resource map within 10 km is developed based on 3 years recorded wind data at 120 m above ground level (agl) (2012-2014) along with computational fluid dynamic (CFD) wind flow modeling with resolution of 90 m. The 5 x 2.0 MW and 4 x 2.5 MW modeled wind farms are positioned along the shoreline with a position criteria of 5 times the rotor diameter between the turbines. The net annual energy production (AEP) and capacity factor (CF) with wake losses are analyzed. The economic analysis is done based on the current project cost and financial incentive (Adder). Results show that the annual mean speed at 120 m agl is 5.2 m/s. The net AEP and CF are 36.60 GWh/year and 41.78%, respectively with wake loss of 0.40%. Under project cost of 75 million THB/MW and 70% debt ratio and Thailand Board of Investment (BOI) tax exemption promotion, the benefit cost ratio is 1.04, the net present value is 65.96 million THB, the financial internal rate of return is 17.70% and the payback period is 4 years. Finally, a 10 MW wind power project could avoid greenhouse gas emission of 19,764 tons CO2eq per year.Keywords: Wind Energy, Wind Farm, Capacity Factor, Wind Flow Modeling, Project Analysis
28
Nguyen, Tan N., Minh Tran, Thanh-Long Nguyen, Duy-Hung Ha, and Miroslav Voznak. "Multisource Power Splitting Energy Harvesting Relaying Network in Half-Duplex System over Block Rayleigh Fading Channel: System Performance Analysis." Electronics 8, no. 1 (January 7, 2019): 67. http://dx.doi.org/10.3390/electronics8010067.
Full textAbstract:
Energy harvesting and information transferring simultaneously by radio frequency (RF) is considered as the novel solution for green-energy wireless communications. From that point of view, the system performance (SP) analysis of multisource power splitting (PS) energy harvesting (EH) relaying network (RN) over block Rayleigh-fading channels is presented and investigated. We investigate the system in both delay-tolerant transmission (DTT), and delay-limited transmission (DLT) modes and devices work in the half-duplex (HD) system. In this model system, the closed-form (CF) expressions for the outage probability (OP), system throughput (ST) in DLT mode and for ergodic capacity (EC) for DTT mode are analyzed and derived, respectively. Furthermore, CF expression for the symbol errors ratio (SER) is demonstrated. Then, the optimal PS factor is investigated. Finally, a Monte Carlo simulation is used for validating the analytical expressions concerning with all system parameters (SP).
29
Hidayat, Azriyenni Azhari Zakri, and Iman Satria. "Feasibility Study of Hydro Power Plant (HPP) Lubuak Gadang Sangir South Solok." International Journal of Electrical, Energy and Power System Engineering 4, no. 1 (February 28, 2021): 121–26. http://dx.doi.org/10.31258/ijeepse.4.1.121-126.
Full textAbstract:
The feasibility study is one of the principal documents in building a hydropower plant consisting of technical, economic, and financial aspects. Contained technical studies on civil, mechanical, and electrical. This requires data on hydrologic, geology, land contours, river discharge, water catchment areas, and so on. Economic and financial studies include cost and financial parameters such as; BEP, IRR, NVP, BCR, and others. The installed capacity of a hydropower plant is given in optimization based on the Flow Duration Curve (FDC) and the Capacity Factor (CF) used the Newton Interpolation Method. The results showed that the installed power capacity was 11.99 MW. The water discharge was 31.603 m3/secs and the effective head was 37.5 meters. Annual income is around IDR 103.026 billion. Finally, HPP Lubuak Gadang is technically, economically, and financially feasible, so it is feasible to carry out the next process.
30
Joy, Obasi Chinenye, Erepamowei Young, Ajoko Imomotimi Timipa, and Tarinimi Tamunosa Jim-Halliday. "Physicochemical Analysis and Pollution Indices for Heavy Metal Assessment in Flooded and Non-flooded Soils of Obunagha, Bayelsa State, Nigeria." International Research Journal of Pure and Applied Chemistry 25, no. 4 (June 25, 2024): 34–43. http://dx.doi.org/10.9734/irjpac/2024/v25i4864.
Full textAbstract:
Soil samples from flood affected areas and non-affected areas of different farmlands in Obunagha, Bayelsa State, Nigeria; were collected for this study. The study was conducted to evaluate the physicochemical properties, and pollution indices of flooded and non-flooded farmlands to see if the flood had any effect in the fertility state of these soils. Atomic absorption spectroscopy (AAS) was used to identify and quantify the several heavy metals (Cd, Cr, Ni, and Zn) that were discovered in the collected soil samples. The findings indicated increased acidity since the pH of the soil varied between 4.8 and 5.7 in farmlands that were flooded and between 4.9 and 5.7 in farmlands that were not. In flooded areas, electrical conductivity ranged from 0.2x101 to 4x101 µS/cm, while in non-flooded areas, it was between 0.2x101 and 2x101 µS/cm. The cation exchange capacity in flooded farmlands was 0.16 to 0.24 meq/100 g, while in non-flooded farmlands it was 0.18 to 0.22 meq/100 g. Variations in metal contamination were found in different farming situations based on the contamination factor (CF) analysis. Chromium CF values ranged from 0.3 to 0.8 in both flooded and non-flooded farmlands, with certain non-flooded farmlands having slightly higher values. Cadmium contamination in flooded farmlands was much higher (25.5 to 43.7 CF) than in non-flooded farmlands (20.0 to 32.0 CF). Nickel contamination levels were from 0.7 to 1.1 in flooded farmlands and 0.5 to 0.8 in non-flooded farmlands, suggesting moderate pollution. Zinc contamination was consistently low throughout all circumstances, with CF values ranging from 0.2 to 0.4. According to the contamination factor average, Cd was followed by Ni, Cr, and Zn in decreasing order. The ecological pollution degree for the study area was low indicating no possible pollution by all the heavy metals. In conclusion, the study area is significantly contaminated with cadmium. Therefore, we urgently recommend monitoring the soil in the surrounding farmlands, particularly for cadmium, to prevent a potential environmental crisis.
31
Radtke, Klaus-Peter, Dean Chamberlain, John H. Griffin, and Andrew J. Gale. "Whole Blood Thromboelastogram Assays Demonstrate Prolonged Factor VIIIa Potency for Recombinant Disulfide Bond-Stabilized Factor VIII Variants." Blood 104, no. 11 (November 16, 2004): 2976. http://dx.doi.org/10.1182/blood.v104.11.2976.2976.
Full textAbstract:
Abstract Following proteolytic activation of factor VIII (FVIII) by thrombin, the FVIIIa A2 domain, A3 domain and light chain (A3-C1-C2 domains) form a non-covalent hetero-trimer. Because spontaneous A2 subunit dissociation causes loss of FVIIIa activity, we previously made two mutants each with two new Cys to form a disulfide bond linking residues 662 (A2) and 1828 (A3) (FVIIIC662-C1828) or residues 664 (A2) and 1826 (A3) (FVIIIC664-C1826). Following thrombin activation, each FVIIIa mutant was stabile compared to wild type (wt) B-domain-deleted (BDD) FVIII. Previous SDS-PAGE data showed that the A2 domain was disulfide linked to the light chain. To show that this is true for undenatured FVIIIa, here we used surface plasmon resonance (SPR) to monitor A2 dissociation from thrombin-activated wild type and variant FVIII species that were bound to the sensor surface via a monoclonal antibody. Following passage of thrombin over sensor-bound FVIII, only wt FVIII showed a characteristic decrease of SPR reflecting A2 subunit dissociation and thrombin-treated FVIIIC662-C1828 and FVIIIC664-C1826 showed only minor decreases in SPR. Thus, SPR data directly demonstrate that engineered inter-domain disulfide bridges between the A2 and A3 domains prevent A2 domain dissociation from FVIIIa. In contrast to simple plasma coagulation assays of FVIIIa, rotational thromboelastogram (RoTEG) assays of whole blood provide multiple parameters reflecting clot formation, clot quality, and clot dissolution. RoTEG assays using fresh severe hemophilia A whole blood that was reconstituted with either wt FVIII, or FVIIIC662-C1828 or FVIIIC664-C1826 were performed to test the hypothesis that the disulfide-stabilized FVIIIa mutants would show improved potency for thrombin generation. After recalcification of hemophilia A blood with added FVIII, we measured the clotting time (CT), the rate of clot-formation, the clot-firmness time (CFT), defined as the time required to reach a specified clot firmness, and the clot firmness at 5 min (CF-A5), defined as the clot firmness at 5 min after the observed CT. Samples reconstituted with disulfide-bridge-stabilized FVIII mutants or wt-FVIII had comparable CTs at similar concentrations. However, in comparison to wild type BDD-FVIII, comparable rates of clot-formation, CFTs and CF-A5 were observed for up to 10-fold lower concentrations of each disulfide-bridge-stabilized FVIII mutant. The differences between wt and FVIII mutants were especially pronounced at very low FVIII concentrations whereas at FVIII concentrations >0.01 U/mL the differences were less apparent. Because clot formation occurs early relative to overall thrombin generation which is better reflected by CFT and CF-A5 values, we interpret these data to indicate that the disulfide-stabilized FVIIIa variants provide sustained thrombin generation in whole blood compared to wt FVIII and speculate that these FVIII variants may prove superior to wt FVIII for stabilizing a hemostatic plug by providing sustained thrombin generation capacity.
32
Prasetyo, Mario Dwi, Aulia Amjad Lutfi, and Bagas Aryo Dananjoyo. "Perencanaan Pembangkit Beban Dasar Menggunakan Briket dengan Mempertimbangkan Aspek Ekonomi dan Keandalan Sistem untuk Mencapai Net Zero Emission." Prosiding SENIATI 6, no. 2 (July 14, 2022): 444–53. http://dx.doi.org/10.36040/seniati.v6i2.4946.
Full textAbstract:
Pemanfaatan briket untuk pembangkit listrik dapat menjadi alternatif masalah eneri baru terbarukan yang intermittent karena biaya yang murah, ramah lingkungan dan ketersediannya terbesar ketiga di dunia setelah batu bara dan minyak. Secara teknis, energi briket bisa digunakan sebagai bahan bakar pembangkit beban dasar seperti PLTU sekaligus solusi bagi perubahan iklim karena berpotensi penetral CO2. Di Indonesia, 40% limbah biomassa masih belum dikelola dengan baik sehingga berpeluang diterapkan sebagai sumber energi primer pembangkit. Penelitian ini bertujuan untuk membandingkan pembangkit PLTU dengan pembangkit tenaga briket dari sudut pandang ekonomi perencanaan dan keandalan sistem. Perhitungan ekonomi perencanaan pembangkit digunakan parameter LCOE pada PLTU, pembangkit briket 25%, 50%, 75%, dan 100%. Sementara itu, keandalan sistem pembangkit diuji menggunakan LOLE dan LOEE pada pembangkit 50% dan 100% briket dengan mempertimbangkan capacity outage generator. Pembangkit briket 100% secara ekonomis layak digunakan sebagai pembangkit beban dasar karena karakteristik kurva antara capacity factor (CF) dan biaya pembangkitan menunjukkan kecenderungan lebih mahal bila dioperasikan dengan nilai CF rendah dan ekonomis apabila beroperasi pada kapasitas besar. Keandalan pembangkitan briket 100% dan briket 50% sama-sama melebihi standar LOLE yaitu 1 hari/tahun di tahun 2030. Nilai LOEE mengikuti LOLE karena saat pemadaman yang lebih lama energi yang tidak tersalurkan menjadi lebih besar.
33
Jiménez-Garrote, Antonio, Francisco J. Santos-Alamillos, Guadalupe Sánchez-Hernández, Miguel López-Cuesta, José A. Ruiz-Arias, and David Pozo-Vázquez. "Evaluation of a Database of the Spanish Wind Energy Resources Derived from a Regional Reanalysis." Energies 17, no. 7 (March 22, 2024): 1523. http://dx.doi.org/10.3390/en17071523.
Full textAbstract:
An enhanced database (RetroDB) of the Spanish wind energy resources, derived from a high spatial resolution integration with the WRF model, is proposed and evaluated. RetroDB provides hourly capacity factor (CF) values for the Spanish regions, along the period of 2007–2020, with an unprecedented spatial resolution. RetroDB estimates were benchmarked based on the ERA5 global reanalysis. A comprehensive evaluation study of both RetroDB and ERA5 estimates was conducted using surface and tall mast measurements, along with actual CF values. The extent to which RetroDB and ERA5 reproduced the CF spatial variability, distribution, and ramp distribution were specifically addressed. The results showed no differences between the global and regional reanalysis performance regarding nationally aggregated wind energy estimates. Nevertheless, RetroDB clearly shows a superior performance reproducing the wind speeds’ and CFs’ spatial and temporal distributions. This was found to be related to the higher reliability of RetroDB reproducing the aloft winds in complex topographic areas. Overall, the results clearly indicate that, in areas such as the study region, where the wind resources are mostly associated with topographic enhancements, high spatial resolution regional reanalyses are preferable over relative coarse reanalyses (e.g., ERA5), particularly for wind energy integration studies. RetroDB database is made publicly available.
34
Egodawatta, Prasanna, and Ashantha Goonetilleke. "Understanding road surface pollutant wash-off and underlying physical processes using simulated rainfall." Water Science and Technology 57, no. 8 (April 1, 2008): 1241–46. http://dx.doi.org/10.2166/wst.2008.260.
Full textAbstract:
Pollutant wash-off is one of the key pollutant processes that detailed knowledge is required in order to develop successful treatment design strategies for urban stormwater. Unfortunately, current knowledge relating to pollutant wash-off is limited. This paper presents the outcomes of a detailed investigation into pollutant wash-off on residential road surfaces. The investigations consisted of research methodologies formulated to overcome the physical constraints due to the heterogeneity of urban paved surfaces and the dependency on naturally occurring rainfall. This entailed the use of small road surface plots and artificially simulated rainfall. Road surfaces were selected due to its critical importance as an urban stormwater pollutant source. The study results showed that the influence of initially available pollutants on the wash-off process was limited. Furthermore, pollutant wash-off from road surfaces can be replicated using an exponential equation. However, the typical version of the exponential wash-off equation needs to be modified by introducing a non dimensional factor referred to as ‘capacity factor' CF. Three rainfall intensity ranges were identified where the variation of CF can be defined. Furthermore, it was found that particulate density rather than size is the critical parameter that influences the process of pollutant wash-off.
35
Yu, H., S. Z. Nasr, and V. Deretic. "Innate Lung Defenses and Compromised Pseudomonas aeruginosa Clearance in the Malnourished Mouse Model of Respiratory Infections in Cystic Fibrosis." Infection and Immunity 68, no. 4 (April 1, 2000): 2142–47. http://dx.doi.org/10.1128/iai.68.4.2142-2147.2000.
Full textAbstract:
ABSTRACT Cystic fibrosis (CF) is characterized by dysfunction of the digestive and respiratory tracts resulting in generalized malnutrition and chronic respiratory infections. Chronic lung infections withPseudomonas aeruginosa, intense neutrophil-dominated airway inflammation, and progressive lung disease are the major cause of high morbidity and mortality in CF. Here we investigated the effects of malnutrition in CF on innate lung defenses, susceptibility to P. aeruginosa colonization, and associated inflammation, using aerosol models of acute and chronic infections in normal, malnourished, and transgenic mice. CFTRm1Unc−/− knockout mice displayed body weight variations and showed variable pulmonary clearance of P. aeruginosa. This variability was not detected in bitransgenicCFTRm1Unc−/− (FABP-hCFTR) mice in which the intestinal defect had been corrected. Diet-induced protein calorie malnutrition in C57BL/6J mice resulted in impaired pulmonary clearance of P. aeruginosa. Tumor necrosis factor alpha (TNF-α) and nitrite levels detected upon exposure to P. aeruginosaaerosols were lower in the lungs of the malnourished C57BL/6J mice relative than in lungs of mice fed a normal diet. The role of TNF-α and reactive nitrogen intermediates in P. aeruginosaclearance was tested in TNF-α and inducible nitric oxide synthase (iNOS) knockout mice. P. aeruginosa clearance was diminished in transgenic TNF-α- and iNOS-deficient mice. In contrast to the effects of TNF-α and iNOS, gamma interferon knockout mice retained a full capacity to eliminate P. aeruginosafrom the lung. Malnutrition also contributed to excessive inflammation in C57BL/6J mice upon chronic challenge with P. aeruginosa. The repeatedly infected malnourished host did not produce interleukin-10, a major anti-inflammatory cytokine absent or diminished in the bronchoalveolar fluids of CF patients. These results are consistent with a model in which defective CFTR in the intestinal tract leads to nutritional deficiency which in turn contributes to compromised innate lung defenses, bacterial colonization, and excessive inflammation in the CF respiratory tract.
36
Raj, M. Nirrmahl, and Jagadeesh Pasupuleti. "Performance assessment of a 619kW photovoltaic power plant in the northeast of peninsular Malaysia." Indonesian Journal of Electrical Engineering and Computer Science 20, no. 1 (October 1, 2020): 9. http://dx.doi.org/10.11591/ijeecs.v20.i1.pp9-15.
Full textAbstract:
<span lang="EN-GB">Photovoltaic (PV) power plants are becoming widely implemented and in larger scale around the world. Understanding performance criteria is crucial in the benchmark of PV plants and ascertaining performance requirements during both design and operational stage of a PV plant. Performance Ratio (PR) and Capacity Factor (CF) are two generally accepted benchmarks for the assessment of a grid connected PV plant. However, within the South East Asia region, and especially within Malaysia, there is a lack of compilation and benchmark for the PR and CF values of existing and operational PV plants. This lack of data is disadvantageous for the designing and assessment of performance of any PV plants in the area. Thus, the focus of this study is to assess the PR and CF performance a 619kW PV plant in the Northeast of Peninsular Malaysia, with the ultimate goal of proposing a standard. From the continuous operation of the said PV plant for the duration of one year, the plant energy production has been obtained and is compared with the simulated energy generation model. Based on the comparison, the plant is determined to be operating with PR value of 0.77 and CF value of 12%. The plant is evaluated to be operating within benchmark values</span><span lang="EN-GB">. These values not only verify the performance of the studied PV plant, they also present a form of comparison </span><span lang="EN-GB">for future studies.</span>
37
Cuevas, José, Ángel Faz, Silvia Martínez-Martínez, María Gabarrón, Juan Beltrá, Jacinto Martínez, and José A. Acosta. "Bio-Monitoring of Metal(loid)s Pollution in Dry Riverbeds Affected by Mining Activity." Plants 12, no. 21 (November 5, 2023): 3775. http://dx.doi.org/10.3390/plants12213775.
Full textAbstract:
The aim of this study was to evaluate the most abundant native plants that could be used as a bio-monitor of metal(loid) concentration in dry riverbeds affected by mining activities. Three plants species and their respective rhizospheric soils were sampled from the El Beal (Piptatherum miliaceum, 15 samples), La Carrasquilla (Foeniculum vulgare, 10 samples), and Ponce (Dittrichia viscosa, 12 samples) dry riverbeds from the mining district of Cartegena-La Unión (SE Spain). There is scanty bibliography of the capacity of these species to be used as bio-monitors in the dry riverbeds. Plants categorized as a bio-monitor were established according to the bioaccumulation factor (BF), mobility ratio (MR), and linear correlations between metal(loid) concentrations in plants tissues (root or stem)-rhizospheric soils. The rhizospheric soils were highly contaminated for As, Cd, Pb, and Zn (Cf ≥ 6), and moderately contaminated for Mn (1 ≤ Cf < 3). Piptatherum miliaceum presented on Cd similar mean concentrations on rhizospheric soil and root, BF = 1.07, with a strong correlation soil–root (r = 0.61, p = 0.02). Therefore, of the three species with the capacity to grow in the area, Piptatherum miliaceum showed characteristics to be considered as a bio-monitor for Cd, with a BF > 1, and a positive–significant correlation between the rhizospheric soil and roots.
38
Gualtieri, Giovanni. "Reliability of ERA5 Reanalysis Data for Wind Resource Assessment: A Comparison against Tall Towers." Energies 14, no. 14 (July 10, 2021): 4169. http://dx.doi.org/10.3390/en14144169.
Full textAbstract:
The reliability of ERA5 reanalyses for directly predicting wind resources and energy production has been assessed against observations from six tall towers installed over very heterogeneous sites around the world. Scores were acceptable at the FINO3 (Germany) offshore platform for both wind speed (bias within 1%, r = 0.95−0.96) and capacity factor (CF, at worst biased by 6.70%) and at the flat and sea-level site of Cabauw (Netherlands) for both wind speed (bias within 7%, r = 0.93−0.94) and CF (bias within 6.82%). Conversely, due to the ERA5 limited resolution (~31 km), large under-predictions were found at the Boulder (US) and Ghoroghchi (Iran) mountain sites, and large over-predictions were found at the Wallaby Creek (Australia) forested site. Therefore, using ERA5 in place of higher-resolution regional reanalysis products or numerical weather prediction models should be avoided when addressing sites with high variation of topography and, in particular, land use. ERA5 scores at the Humansdorp (South Africa) coastal location were generally acceptable, at least for wind speed (bias of 14%, r = 0.84) if not for CF (biased by 20.84%). However, due to the inherent sea–land discontinuity resulting in large differences in both surface roughness and solar irradiation (and thus stability conditions), a particular caution should be paid when applying ERA5 over coastal locations.
39
Verasoundarapandian, Gayathiri, Nur Nadhirah Zakaria, Noor Azmi Shaharuddin, Khalilah Abdul Khalil, Nurul Aini Puasa, Alyza Azzura Azmi, Claudio Gomez-Fuentes, et al. "Coco Peat as Agricultural Waste Sorbent for Sustainable Diesel-Filter System." Plants 10, no. 11 (November 16, 2021): 2468. http://dx.doi.org/10.3390/plants10112468.
Full textAbstract:
Oil spill incidents are hazardous and have prolonged damage to the marine environment. Management and spill clean-up procedures are practical and rapid, with several shortcomings. Coco peat (CP) and coco fibre (CF) are refined from coconut waste, and their abundance makes them desirable for diesel spillage treatment. Using a filter-based system, the selectivity of coco peat sorbent was tested using CP, CF and peat-fibre mix (CPM). CP exhibited maximal diesel sorption capacity with minimal seawater uptake, thus being selected for further optimisation analysis. The heat treatment considerably improved the sorption capacity and efficiency of diesel absorbed by CP, as supported by FTIR and VPSEM–EDX analysis. Conventional one-factor-at-a-time (OFAT) examined the performance of diesel sorption by CP under varying parameters, namely temperature, time of heating, packing density and diesel concentration. The significant factors were statistically evaluated using response surface methodology (RSM) via Plackett–Burman design (PB) and central composite design (CCD). Three significant (p < 0.05) factors (time, packing density and diesel concentration) were identified by PB and further analysed for interactions among the parameters. CCD predicted efficiency of diesel absorbed at 59.92% (71.90 mL) (initial diesel concentration of 30% v/v) and the experimental model validated the design with 59.17% (71.00 mL) diesel sorbed at the optimised conditions of 14.1 min of heating (200 °C) with packing density of 0.08 g/cm3 and 30% (v/v) of diesel concentration. The performance of CP in RSM (59.17%) was better than that in OFAT (58.33%). The discoveries imply that natural sorbent materials such as CP in oil spill clean-up operations can be advantageous and environmentally feasible. This study also demonstrated the diesel-filter system as a pilot study for the prospective up-scale application of oil spills.
40
Adiprana, Reza, Danu Sito Purnomo, and Iwan Setiono. "Kamojang Geothermal Power Plant Unit-1 : 30 Years of Operation." Applied Mechanics and Materials 493 (January 2014): 56–61. http://dx.doi.org/10.4028/www.scientific.net/amm.493.56.
Full textAbstract:
UNIT-1 KAMOJANG geothermal power plant marked the new era of renewable energy in Indonesia. With its built capacity of 30 MWe, it constantly supply electricity to Java-Bali grid for more than 30 years now.Over those period, Unit-1 has given its best performance with highest achievement on Capacity Factor (CF) and Equivalent Availability Factor (EAF).High performance geothermal power plant involves the integration not only from the point of view of power generation, but also the optimation of geothermal potention in the area. Kamojang geothermal field, which is considered as one among five steam dominated reservoir in the world produces 200 MWe of the electricity nowadays. In order to maintain this production rate, some technical consideration must be made.Towards sustainable power generation of geothermal power, some assessment has been made to turbine, generator and cooling tower to ensure its current condition. Basically what it called remaining life assessment gives a rough picture of how long the equipment will run through in its operational condition.Based on those assessment, additional 20.900 hours is given to the turbine with the existing operating conditions. On the other hand, cooling tower infrastucture test and simulation delivers operation period for another 25 years.
41
Tumse, Sergen, Mehmet Bilgili, Alper Yildirim, and Besir Sahin. "Comparative Analysis of Global Onshore and Offshore Wind Energy Characteristics and Potentials." Sustainability 16, no. 15 (August 2, 2024): 6614. http://dx.doi.org/10.3390/su16156614.
Full textAbstract:
Wind energy, which generates zero emissions, is an environmentally friendly alternative to conventional electricity generation. For this reason, wind energy is a very popular topic, and there are many studies on this subject. Previous studies have often focused on onshore or offshore installations, lacking comprehensive comparisons and often not accounting for technological advancements and their impact on cost and efficiency. This study addresses these gaps by comparing onshore and offshore wind turbines worldwide in terms of installed capacity, levelized cost of electricity (LCOE), total installed cost (TIC), capacity factor (CF), turbine capacity, hub height, and rotor diameter. Results show that onshore wind power capacity constituted 98.49% in 2010, 97.23% in 2015, and 92.9% in 2022 of the world’s total cumulative installed wind power capacity. Offshore wind capacity has increased yearly due to advantages like stronger, more stable winds and easier installation of large turbine components. LCOE for onshore wind farms decreased from 0.1021 USD/kWh in 2010 to 0.0331 USD/kWh in 2021, while offshore LCOE decreased from 0.1879 USD/kWh in 2010 to 0.0752 USD/kWh in 2021. By 2050, wind energy will contribute to 35% of the global electricity production. This study overcomes previous limitations by providing a comprehensive and updated comparison that incorporates recent technological advancements and market trends to better inform future energy policies and investments.
42
Rachman, Rizal, Sari Susanti, Hendi Suhendi, and Adi Karawinata Satyanegara. "Artificial intelligence detection of refractive eye diseases using certainty factor and image processing." Indonesian Journal of Electrical Engineering and Computer Science 36, no. 3 (December 1, 2024): 1787. http://dx.doi.org/10.11591/ijeecs.v36.i3.pp1787-1797.
Full textAbstract:
Refractive errors are defined as an impairment in the eye’s capacity to focus light, resulting in the formation of blurred or unfocused images. These issues arise from alterations in the shape of the cornea, the length of the eyeball, or the aging of the crystalline lens. It is anticipated that the prevalence of visual impairment will increase in conjunction with global population growth. At present, a significant number of countries have not yet accorded sufficient priority to eye health within their healthcare systems. This has resulted in insufficient awareness and reluctance to seek costly specialized care. This study proposes the development of an advanced refractive eye disease detection system with the objective of improving diagnostic accuracy, disseminating disease information, and reducing financial barriers to specialist consultation. The research employs certainty factor (CF) methods and image processing with feature extraction. The initial results demonstrate the potential for identifying specific refractive eye diseases with high certainty through the analysis of symptoms and the examination of photographs of the eye. The proposed approach provides an alternative method for diagnosing refractive eye diseases, which could enhance access to refractive eye care services and reduce the economic burden on patients.
43
Sañudo-Fontaneda, Luis A., Jorge Rodriguez-Hernandez, Angel Vega-Zamanillo, and Daniel Castro-Fresno. "Laboratory analysis of the infiltration capacity of interlocking concrete block pavements in car parks." Water Science and Technology 67, no. 3 (February 1, 2013): 675–81. http://dx.doi.org/10.2166/wst.2012.614.
Full textAbstract:
Interlocking concrete block pavements (ICBPs) have been widely used in car parks to reduce runoff. Researches have demonstrated that clogging is the most influential factor in the reduction of the infiltration capacity of this type of permeable pavement. Nevertheless, there is no laboratory study of the infiltration performance of ICBPs that combines clogging levels with variables related with the topography of car parks such as runoff surface length (RSL) and surface slope (SS). This paper studies the infiltration behaviour of ICBP during their operational life in a car park using an improved version of the Cantabrian Fixed (CF) Infiltrometer. This laboratory device simulates direct rainfall and runoff from adjacent impervious areas over an ICBPs surface of 0.25 m2 for different slopes (0, 3, 5, 7 and 10%) and three scenarios of clogging (surface newly built, surface clogged and surface clogged with maintenance). This paper presents the results of the tests and a statistical analysis based on three regression models (corresponding to each clogging scenario) depending on the RSL and SS variables. All models passed a confidence level of 95%, presenting high R2 values and showing that RSL is a more influential variable than the SS for all clogging scenarios.
44
Iñigo-Labairu, Javier, Jürgen Dersch, Tobias Hirsch, Stefano Giuliano, Matthias Loevenich, and Diego Córdoba. "Techno-Economic Evaluation of CSP–PV Hybrid Plants with Heat Pump in a Temperature Booster Configuration." Energies 17, no. 11 (May 29, 2024): 2634. http://dx.doi.org/10.3390/en17112634.
Full textAbstract:
Concentrated solar power (CSP)—photovoltaic (PV) hybrid power plants allow for the generation of cheap electrical energy with a high capacity factor (CF). A deep integration of both technologies offers synergies, using parts of the PV generated electricity for heating the thermal storage tank of the CSP unit. Such configurations have been previously studied for systems coupled by an electric resistance heater (ERH). In this work, the coupling of a CSP and a PV plant using a heat pump (HP) was analyzed due to the higher efficiency of heat pumps. The heat pump is used as a booster to lift the salt temperature in the storage system from 383 to 565 °C in order to reach higher turbine efficiency. A techno-economic analysis of the system was performed using the levelized cost of electricity (LCOE), the capacity factor and nighttime electricity fraction as variables for the representation. The CSP–PV hybrid with a booster heat pump was compared with other technologies such as a CSP–PV hybrid plant coupled by an electric heater, a standalone parabolic trough plant (PT), a photovoltaic system with battery storage (PV–BESS), and a PV thermal power plant (PVTP) consisting of a PV plant with an electric heater, thermal energy storage (TES) and a power block (PB).
45
Komar, D., M. Dolenec, T. Dolenec, P. Vrhovnik, S. Lojen, G. Kniewald, S. S. Matešić, Ž. Lambaša Belak, and M. Orlando-Bonaca. "Benthic organisms as ecological indicators for the status assessment of coastal ecosystems." Journal of the Marine Biological Association of the United Kingdom 98, no. 8 (August 24, 2017): 1907–17. http://dx.doi.org/10.1017/s0025315417001527.
Full textAbstract:
The presence of potentially toxic elements (PTE) was determined in different tissues of five selected marine organisms. The As, Cd, Cu, Mn, Mo, Ni, Pb and Zn concentrations were measured in the seagrass Cymodocea nodosa, the green alga Cladophora echinus, the red alga Gelidiella lubrica, the marine topshell Phorcus turbinatus and the littoral crab Carcinus aestuarii, as well as in seawater from Makirina Bay. The levels of As, Cd, Cu, Mn and Zn in the biota were found to exceed those in previously analysed sediments, indicating the bioaccumulation of these PTE. The biota-sediment accumulation factor (BSAF) and concentration factor (CF) varied among different organisms. As regards the five selected species, C. nodosa, C. echinus and G. lubrica proved to be the strongest accumulators of Mn, while P. turbinatus and C. aestuarii showed a high capacity to accumulate As, Cd, Cu and Zn. These species can be considered as good ecological indicators in the assessment of PTE pollution in marine littoral environments.
46
Medzikovic, Lejla, Hylja Heese, Pieter B. van Loenen, Cindy P. A. A. van Roomen, Ingeborg B. Hooijkaas, Vincent M. Christoffels, Esther E. Creemers, Carlie J. M. de Vries, and Vivian de Waard. "Nuclear Receptor Nur77 Controls Cardiac Fibrosis through Distinct Actions on Fibroblasts and Cardiomyocytes." International Journal of Molecular Sciences 22, no. 4 (February 5, 2021): 1600. http://dx.doi.org/10.3390/ijms22041600.
Full textAbstract:
Fibrosis is a hallmark of adverse cardiac remodeling, which promotes heart failure, but it is also an essential repair mechanism to prevent cardiac rupture, signifying the importance of appropriate regulation of this process. In the remodeling heart, cardiac fibroblasts (CFs) differentiate into myofibroblasts (MyoFB), which are the key mediators of the fibrotic response. Additionally, cardiomyocytes are involved by providing pro-fibrotic cues. Nuclear receptor Nur77 is known to reduce cardiac hypertrophy and associated fibrosis; however, the exact function of Nur77 in the fibrotic response is yet unknown. Here, we show that Nur77-deficient mice exhibit severe myocardial wall thinning, rupture and reduced collagen fiber density after myocardial infarction and chronic isoproterenol (ISO) infusion. Upon Nur77 knockdown in cultured rat CFs, expression of MyoFB markers and extracellular matrix proteins is reduced after stimulation with ISO or transforming growth factor–β (TGF-β). Accordingly, Nur77-depleted CFs produce less collagen and exhibit diminished proliferation and wound closure capacity. Interestingly, Nur77 knockdown in neonatal rat cardiomyocytes results in increased paracrine induction of MyoFB differentiation, which was blocked by TGF-β receptor antagonism. Taken together, Nur77-mediated regulation involves CF-intrinsic promotion of CF-to-MyoFB transition and inhibition of cardiomyocyte-driven paracrine TGF-β-mediated MyoFB differentiation. As such, Nur77 provides distinct, cell-specific regulation of cardiac fibrosis.
47
Tzoraki, Ourania. "Operating Small Hydropower Plants in Greece under Intermittent Flow Uncertainty: The Case of Tsiknias River (Lesvos)." Challenges 11, no. 2 (August 3, 2020): 17. http://dx.doi.org/10.3390/challe11020017.
Full textAbstract:
In arid and semi-arid parts of the world, river exploitation is intensive, involving water storage for irrigation or hydropower generation. In Greece, 100 small hydropower plants (SHPs) take advantage of less than 10% of the hydropower potential of low flow streams (<2 m3/s), a very small amount in relation to the 70% of the European Union. The energy policy of complete decarbonization of the country by 2023 on a national scale opens the road for new investments in SHP projects, especially in intermittent-flow streams of the Greek islands. Simulated flows by the Modello Idrologico SemiDistribuito in continuo (MISDc model) are used to construct the annual flow duration curve (FDC) to study and assess the hydropower potential of an intermittent stream (Tsiknias river, Lesvos, Greece). For Tsiknias River, but also for six other intermittent-flow rivers of Crete island, the capacity factor (CF), which represents the mean annual power of the hydropower plant, should remain >75% to exploit the river’s potential. The FDC and CF are essential in designing SHP projects in intermittent-flow streams with long no-flow periods. The development of public participatory approaches and a closer cooperation among policy makers and stakeholders should work to promote hydropower exploitation and accelerate licensing procedures.
48
Liu, Yulin, Zhouping Shangguan, and Lei Deng. "Vegetation Type and Soil Moisture Drive Variations in Leaf Litter Decomposition Following Secondary Forest Succession." Forests 12, no. 9 (September 3, 2021): 1195. http://dx.doi.org/10.3390/f12091195.
Full textAbstract:
Soil moisture was an important factor affecting litter decomposition. However, less attention has been given to the complete succession ecosystem after farmland abandonment. To better understand the effect of moisture on leaf litter decomposition after farmland abandonment, in this study, we used three water gradients (10%, 25% and 50%) of field moisture capacity for succession vegetation. Furthermore, we used the typical species leaf litter decomposition of four succession stages—grassland (GL), shrubland (SL), pioneer forest (PF), and climax forest (CF) from the Loess Plateau of China. The results showed that leaves decomposition rate exhibited an increasing pattern with increasing moisture contents. The decomposition trend was shown as GL > SL > PF > CF. During the decomposition process, the leaf carbon concentration (LC) and leaf nitrogen concentration (LN) changed, but non-significantly. The effects of LC, LN, and LC: LN on leaf decomposition varied with vegetation type. Soil properties such as NH4+, NO3−, dissolved organic nitrogen (DON), and leaf quality parameters such as leaf cellulose, lignin, lignin: LN, and lignin: LC played an important role in driving leaf litter decomposition. Overall, the results provide evidence that litter decomposition in secondary forest succession system was linked to leaf and soil nutrient dynamics, and was limited by soil moisture.
49
Gkaidatzis, Paschalis, Aggelos Bouhouras, Kallisthenis Sgouras, Dimitrios Doukas, Georgios Christoforidis, and Dimitris Labridis. "Efficient RES Penetration under Optimal Distributed Generation Placement Approach." Energies 12, no. 7 (April 1, 2019): 1250. http://dx.doi.org/10.3390/en12071250.
Full textAbstract:
In this paper, a novel version of the Optimal Distributed Generation Placement (ODGP) problem regarding the siting and sizing of Renewable Energy Sources (RESs) units is presented, called Optimal RES placement (ORESP). Power losses constitute the objective function to be minimized, subject to operational constraints. The simultaneous installation of a mix of RESs is considered and the Capacity Factor (CF) ratio is used as an aid for taking into account: (a) the geographical characteristics of the area, in which the examined Distribution Network (DN) is placed, (b) the different weather conditions, and (c) the availability of RESs, all of that at the same time, while keeping the problem complexity at minimum. The contribution of this work is that the proposed methodology bypasses the weather uncertainties and, thus, the RESs’ power generation stochasticity and provides an adequate solution with minimum computational burden and time, since the proposed CF use allows solving the problem under a straightforward way. Unified Particle Swarm Optimization (uPSO) is used for solving ODGP and ORESP. Moreover, a sensitivity analysis regarding the CFs variations is performed and finally a comparison of the proposed method with a more realistic one is performed, to consolidate further the claims of this paper. The proposed method is evaluated on RES-region-modified 33- and 118 bus systems.
50
He, Haibing, Ru Yang, Biao Jia, Lin Chen, Hua Fan, Jing Cui, Dong Yang, Menglong Li, and Fu-Yu Ma. "Rice Photosynthetic Productivity and PSII Photochemistry under Nonflooded Irrigation." Scientific World Journal 2014 (2014): 1–14. http://dx.doi.org/10.1155/2014/839658.
Full textAbstract:
Nonflooded irrigation is an important water-saving rice cultivation technology, but little is known on its photosynthetic mechanism. The aims of this work were to investigate photosynthetic characteristics of rice during grain filling stage under three nonflooded irrigation treatments: furrow irrigation with plastic mulching (FIM), furrow irrigation with nonmulching (FIN), and drip irrigation with plastic mulching (DI). Compared with the conventional flooding (CF) treatment, those grown in the nonflooded irrigation treatments showed lower net photosynthetic rate(PN), lower maximum quantum yield(Fv/Fm), and lower effective quantum yield of PSII photochemistry (ΦPSII). And the poor photosynthetic characteristics in the nonflooded irrigation treatments were mainly attributed to the low total nitrogen content (TNC). Under non-flooded irrigation, thePN,Fv/Fm, andΦPSIIsignificantly decreased with a reduction in the soil water potential, but these parameters were rapidly recovered in the DI and FIM treatments when supplementary irrigation was applied. Moreover, The DI treatment always had higher photosynthetic productivity than the FIM and FIN treatments. Grain yield, matter translocation, and dry matter post-anthesis (DMPA) were the highest in the CF treatment, followed by the DI, FIM, and FIN treatments in turn. In conclusion, increasing nitrogen content in leaf of rice plants could be a key factor to improve photosynthetic capacity in nonflooded irrigation.