363 research outputs found

    Unveiling the role of carbon defects in the exceptional narrowing of m-ZrO2 bandgap for enhanced photoelectrochemical water splitting performance

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    The development of efficient photoelectrodes via defect engineering of wide-band gap metal oxides has been the prime focus for many years. Specifically, the effect of carbon defects in wide-band gap metal oxides on their performance in photoelectrochemical (PEC) applications raised numerous controversies and still elusive. Herein, the effect of various carbon defects in m-ZrO2 was investigated using the density functional theory to probe the thermodynamic, electronic, and optical properties of the defective structures against pristine m-ZrO2. The defect formation energies revealed that elevating the temperature promotes and facilitates the formation of carbon defects. Moreover, the binding energies confirmed the stability of all studied complex carbon defects. Furthermore, the band edge positions against the redox potentials of water species revealed that all the studied defective structures can serve as photoanodes for water splitting. Additionally, CO3c (carbon atom substituted O3c site) was the only defective structure that exhibited slight straddling of the redox potentials of water. Importantly, all investigated defective structures enhanced light absorption with different optical activities. Finally, CO3cVO3c (carbon atom substituted O3c associated with O3c vacancy) defective m-ZrO2 enjoyed low direct band gap (1.9 eV), low defect formation energy, low exciton binding energy, high mobility of charge carriers, fast charge transfer, and low recombination rate. Concurrently, its optical properties were exceptional in terms of high absorption, low reflectivity and improved static dielectric constant. Hence, the study recommends CO3cVO3c defective m-ZrO2 as the leading candidate to serve as a photoanode for PEC applications

    An efficient chameleon swarm algorithm for economic load dispatch problem

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    Economic Load Dispatch (ELD) is a complicated and demanding problem for power engineers. ELD relates to the minimization of the economic cost of production, thereby allocating the produced power by each unit in the most possible economic manner. In recent years, emphasis has been laid on minimization of emissions, in addition to cost, resulting in the Combined Economic and Emission Dispatch (CEED) problem. The solutions of the ELD and CEED problems are mostly dominated by metaheuristics. The performance of the Chameleon Swarm Algorithm (CSA) for solving the ELD problem was tested in this work. CSA mimics the hunting and food searching mechanism of chameleons. This algorithm takes into account the dynamics of food hunting of the chameleon on trees, deserts, and near swamps. The performance of the aforementioned algorithm was compared with a number of advanced algorithms in solving the ELD and CEED problems, such as Sine Cosine Algorithm (SCA), Grey Wolf Optimization (GWO), and Earth Worm Algorithm (EWA). The simulated results established the efficacy of the proposed CSA algorithm. The power mismatch factor is the main item in ELD problems. The best value of this factor must tend to nearly zero. The CSA algorithm achieves the best power mismatch values of 3.16×10−13, 4.16×10−12 and 1.28×10−12 for demand loads of 700, 1000, and 1200 MW, respectively, of the ELD problem. The CSA algorithm achieves the best power mismatch values of 6.41×10−13 , 8.92×10−13 and 1.68×10−12 for demand loads of 700, 1000, and 1200 MW, respectively, of the CEED problem. Thus, the CSA algorithm was found to be superior to the algorithms compared in this work

    Технология сухого производства фосфоритовой муки

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    Описана технологія виробництва сухого фосфоритового борошна, яка включає просівання, дрібне дроблення, термічну сушіння, кульове подрібнення в замкнутому циклі з контрольним сепарацією, пневмотранспорт фосфоритового борошна в силосу. Продуктив-ність технологічної лінії – 150 тис. т у рік. Крупность помолу становить 70% кл. 0,16 мм при вологості 1%.Описана технология сухого производства фосфоритовой муки, которая включает грохочение, мелкое дробление, термическую сушку, шаровое измельчение в замкнутом цикле с контрольным грохочением, пневмотранспорт фосфоритовой муки в силоса. Производительность технологической линии – 150 тыс. т в год. Крупность помола составляет 70% кл. 0,16 мм при влажности 1%

    Improvement of the approaches to improve the health of the population in the regions of Russia

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    Significant differentiation of socio-economic indicators of the subjects of the Russian Federation indicates significant regional differences in the initial conditions of demographic development. The aim of the study is to develop measures to improve the policy in the field of public health at the regional level in Russia, taking into account the factors of formation of public health. We conducted a factor analysis of the socio-economic situation in the regions, followed by clustering on the basis of a list of selected statistical indicators, which allowed us to develop common approaches to improving health policy for each group of subjects of the Russian Federation, taking into account their main historical, geographical and socioeconomic characteristics

    GEOLOGICAL FEATURES IDENTIFIED FROM FIELD OBSERVATIONS AND REMOTE SENSING DATA ON THE UM TAGHIR AREA, EASTERN DESERT, EGYPT

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    The current study presents the integration between field observations and remotely sensed data for detection and extraction of geological structural features using Sentinel-2A and Aster DEM images. The area under investigation is represented by the Neoproterozoic East African Orogeny encompassing a part of the Arabian Nubian Shield. All the rock units studied belong to the Late Cryogenian-Ediacaran periods that are divided into two large terrains (continental arc terrain and oceanic arc terrain). The metagabbro and metavolcaniclastic rocks make up the oceanic terrain, while the gabbro, tonalite, granodiorite, dokhan volcanic, monzogranite and alkali feldspar granite comprise continental arc terrain. The Sentinel-2A remote sensing and ASTER DEM data have meaningful application in respect of geological interpretation. Lineament analysis is one of the most useful tools in geological mapping and mineral exploration. Several methods of processing and extracting lithological information and lineaments were applied to the Sentinel-2A and ASTER DEM data covering the present study. The methods include various image enhancements (FCC, MNF and PCA) and the application of directional filters (Sobel). The study results show that the area was subjected to stresses of various directions (WNW – ESE, NW-SE, NE-SW, N-S, NNE – SSW, and E-W). There occurred some important structure-related and mineralization events like migmatization (in granodiorites) and bearing mineralization (in gabbro), which are associated with major elements of evidence-based structural control of the area and with the proximity of the Quena Safaga shear zone-related mineralization

    ГЕОЛОГИЧЕСКИЕ ПРИЗНАКИ, ВЫЯВЛЕННЫЕ ПО ДАННЫМ ПОЛЕВЫХ НАБЛЮДЕНИЙ И ДИСТАНЦИОННОГО ЗОНДИРОВАНИЯ В РАЙОНЕ УМ ТАГИР, ВОСТОЧНАЯ ПУСТЫНЯ, ЕГИПЕТ

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    The current study presents the integration between field observations and remotely sensed data for detection and extraction of geological structural features using Sentinel-2A and Aster DEM images. The area under investigation is represented by the Neoproterozoic East African Orogeny encompassing a part of the Arabian Nubian Shield. All the rock units studied belong to the Late Cryogenian-Ediacaran periods that are divided into two large terrains (continental arc terrain and oceanic arc terrain). The metagabbro and metavolcaniclastic rocks make up the oceanic terrain, while the gabbro, tonalite, granodiorite, dokhan volcanic, monzogranite and alkali feldspar granite comprise continental arc terrain. The Sentinel-2A remote sensing and ASTER DEM data have meaningful application in respect of geological interpretation. Lineament analysis is one of the most useful tools in geological mapping and mineral exploration. Several methods of processing and extracting lithological information and lineaments were applied to the Sentinel-2A and ASTER DEM data covering the present study. The methods include various image enhancements (FCC, MNF and PCA) and the application of directional filters (Sobel). The study results show that the area was subjected to stresses of various directions (WNW – ESE, NW-SE, NE-SW, N-S, NNE – SSW, and E-W). There occurred some important structure-related and mineralization events like migmatization (in granodiorites) and bearing mineralization (in gabbro), which are associated with major elements of evidence-based structural control of the area and with the proximity of the Quena Safaga shear zone-related mineralization.Темой исследования является интеграция данных полевых наблюдений и дистанционного зондирования с целью обнаружения и извлечения геолого-структурных признаков с помощью спутниковых снимков Sentinel-2A и цифровой модели рельефа ASTER DEM. Исследуемый район представляет собой неопротерозойскую восточно-африканскую орогению, охватывающую часть Нубийско-Аравийского щита. Изучаемые толщи пород относятся к позднему криогению – эдиакарию и образуют два террейна (континентальный дуговой террейн и океанический дуговой террейн). Океанический террейн сложен метагаббро и метавулканокластическими породами, а габбро, тоналиты, гранодиориты, доханские вулканиты, монцониты и щелочные полевошпатовые граниты слагают континентальный дуговой террейн. Данные со спутника Sentinel-2A, а также данные ASTER DEM используются для геологической интерпретации. Линеаментный анализ является одним из наиболее полезных инструментов геологического картирования и разведки полезных ископаемых. В рамках исследования были использованы методы для обработки данных Sentinel-2A и ASTER DEM, извлечения литологической информации из снимков и проведения линеаментного анализа снимков. Это различные методы увеличения изображения (FCC, MNF и PCA) и применения направленных фильтров (Sobel). Результаты исследования указывают на то, что в данной области имели место напряжения различной направленности (ЗСЗ – ВЮВ, СЗ-ЮВ, СВ-ЮЗ, С-Ю, ССВ – ЮЮЗ и В-З). Образовалось несколько крупных сопутствующих структур и произошло несколько событий в процессе минерализации, таких как мигматизация (в гранодиоритах) и минерализация по простиранию (в габбро), обусловленных главными элементами научно обоснованного структурного контроля территории и близостью нахождения минерализованной зоны сдвига Кена-Сафага

    PERFORMANCE AND STABILITY OF SOME BREAD WHEAT GENOTYPES FOR GRAIN YIELD, PROTEIN AND GLUTEN CONTENTS UNDER DIFFERENT ENVIRONMENTAL CONDITIONS

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    Seventeen genotypes (G) of bread wheat (14 promising lines and 3 commercial cultivars) were evaluated for mean performance and stability of grain yield/plant, grain protein content and dry gluten percentage under 16 environments (two locations (L), two sowing dates(D) and four fertilization treatments (F)). The resultsconfirmed the existence of considerable genetic variation among genotypes and their performance was significantly affected by different environments for the studied traits. Kalubia locations recorded the highest mean values for grain yield/plant while; Fayoum location recorded the highest mean values for the two quality traits. Yield and quality traits were significantly increased on early (recommended) sowing dates at Kalubia and Fayoum locations than on late sowing dates. Applying biofertilizer only gave the lowest mean performance in all traits, but adding mineral N besides biofertilizer markedly increased grain yield/plant and the two quality traits. However, insignificant differences existed between the rate of nitrogen recommended (80kg N/fed.) and the rate of (biofertilizer + 60kgN/fed.), indicating that biofertilizer could be efficient in reducing costs of the expensive mineral N and reducing environmental pollution. On an average highest values of grain yield/plant were recorded by the promising wheat lines no. 10 (24.57 g), no. 9 (22.50 g), and no. 11 (21.64 g) as compared to the best check cultivar Giza 168. Meantime, this cultivar surpassed the other genotypes in protein and dry gluten percentages. Concerning phenotypic stability, the three superior lines no. 10, 9 and 11 gave the highest mean values (x¯) of grain/plant coupled with significant regression coefficient (bi) values higher than unity and significant deviation from regression (S2di), thus they considered specifically adapted to favourable environments
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