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Conventional generation emulation for power grids with a high penetration of wind power

Clean Energy 2021年第1期5卷 93-103页

作者： Rasha El-Azab eslam m.Wazeer mohamed Daowd A.m.abdel Ghany Electrical Power and machines Department Faculty of EngineeringHelwan UniversityCairoEgypt

Integrating large-scale wind plants with the electricity grids has many challenges for grid *** the variability and uncertainty of wind power,coordinating between different technologies of generation in the same grid can be considered the main problem,specifically for short-term frequency ***,a large penetration of wind power generation in modern power grids has a risky influence on the power-system ***-generation plants have contradictory behaviour compared to classic thermal plants,especially in active generated power-shortage events due to the variable nature of wind *** experience in wind plants keeps part of the available wind power unloaded,using what are known as deloading *** deloading techniques are usually applied to emulate the thermal-plant-governor function and confirm a proper spinning reserve for any active-power *** techniques decrease the generated power from wind plants continuously from maximum point tracking ***,the practical capacity,annual generated energy and economical income of wind plants are *** addition,grid-protection and control sub-schemes are set and designed according to the well-known conventional responses of thermal plants,which increase the need for thermal-plant-behaviour *** this paper,instead of the usual deloading methods,a supercapacitors scheme is proposed with wind turbines to emulate the response of conventional power *** study discusses the technical and economic benefits of the proposed addition of supercapacitors in the wind-plant-planning *** frequency grid-code indices are selected to evaluate studied *** results of the IEEE four-generation two-area system determines the effectiveness of suggested schemes *** System Advisor model(SAm)program estimates the economic benefits of a typical US study case compared with the existing wind-deloading technique.

关键词： wind energy planning analysis energy storage supercapacitor frequency stability

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Evaluation of the chemical constituents,antioxidant and enzyme inhibitory activities of six Yemeni green coffee beans varieties

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Food Bioscience 2022年第2期46卷 1006-1013页

作者： Ammar mohammed Ahmed Ali Sakina Yagi Ahmed A.Qahtan Abdurrahman A.Alatar Simone Angeloni Filippo maggi Giovanni Caprioli eslam.m.abdel-salam Kouadio Ibrahime Sinan Gokhan Zengin Department of Biology Faculty of EducationHajji UniversityHajjahYemen Botany Department Faculty of ScienceUniversity of KhartoumSudan Department of Botany&microbiology College of ScienceKing Saud UniversityP.O.Box 2455Riyadh11451Saudi Arabia Chemistry Interdisciplinary Project(ChIP) School of PharmacyUniversity of CamerinoVia Madonna delle Carceri 9/BI62032CamerinoMCItaly Physiology and Biochemistry Laboratory Department of BiologyScience FacultySelcuk UniversityCampus42103KonyaTurkey

Coffee arabica *** an economical crop cultivated in many countries including *** present study evaluated the phytochemical contents of the methanolic extracts,prepared by maceration,of six Yemeni green coffee beans varieties namely Esmaeli,Hamadi,Harazi,mattari,Odaini and ***(phosphomolybdenum,antiradical,reducing power and ferrous chelating),and enzyme inhibition activity of the extracts against acetylcholinesterase butyrylcholinesterase,tyrosinase,α-glucosidase,andα-amylase were also *** of total phenols revealed that all green beans varieties were richer in their total polyphenolic(63.77-110.98 mg gallic acid equivalent per g of extract)content than their flavonoids one(2.86-5.57 mg rutin equivalent per g of extract).HPLC-mS/mS analysis of 30 selected bioactive compounds showed that all varieties had the same types of phytoconstituents with differences in their relative ***(1613.89-2466.38μg/g)followed by 5-caffeoylquinic acid(1017.63-1313.39μg/g)were the dominant compounds in all varieties with caffeine more abundant in Esmaeli variety while 5-caffeoylquinic acid in Odaini *** varieties displayed a pronounced antioxidant property in all the in vitro assays with Odaini variety significantly(pmg Trolox equivalent(TE)/g),metal chelating(19.73 mg Disodium edetate equivalents/g),Cu^(2+)(441.11 mg TE/g)and Fe3+(221.04 mg TE/g)reducing ***,the majority of green coffee beans varieties showed comparable enzyme inhibition property with highest activity recorded against tyrosinase(39.35-46.96 mg kojic acid equivalents/g)and acetylcholinesterase(1.80-2.17 mg galanthamine equivalents/g)*** conclusion,all Yemeni green coffee beans varieties have proven to be rich source of biochemicals with beneficial impact on human health and could be of significant applications in food,pharmaceutical and cosmetics industry.

关键词： Yemeni coffee Phytoconstituents Green coffee HPLC-mS/mS Antioxidants Enzyme inhibitory properties

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A Class of Pseudo-Real Riemann Surfaces with Diagonal Automorphism Group

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Algebra Colloquium 2020年第2期27卷 247-262页

作者： eslam Badr Department of mathematics Facility of Science Cairo UniversityGiza 12613Egypt

A Riemann surface S having field of moduli m,but not a field of definition,is called *** means that S has anticonformal automorphisms,but none of them is an involution.A Riemann surface is said to be plane if it can be described by a smooth plane model of some degree d≥4 in P^2/*** characterize pseudo-real-plane Riemann surfaces»S,whose conformal automorphism group Aut+(S)is PGL3(C)-conjugate to a finite non-trivial group that leaves invariant infinitely many points of P^2/*** particular,we show that such pseudo-real-plane Riemann surfaces exist only if Aut+(S)is cyclic of even order n dividing the degree *** families of pseudo-reai-plane Riemann surfaces are given for any degree d=2pm with m>1 odd,p prime and n=d/p.

关键词： pseudo-real Riemann surface field of moduli field of definition plane curve automorphism group

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Biomarkers of metabolic(Dysfunction)-associated Fatty Liver Disease:An Update

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Journal of Clinical and Translational Hepatology 2022年第1期10卷 134-139页

作者： Jawaher Alharthi mohammed eslam Storr Liver Centre Westmead Institute for Medical ResearchWestmead Hospital and University of SydneySydneyNSWAustralia Department of Biotechnology Faculty of ScienceTaif UniversityTaifSaudi Arabi

The prevalence of metabolic(dysfunction)-associated fatty liver disease(mAFLD)is rapidly increasing and affects up to two billion individuals globally,and this has also resulted in increased risks for cirrhosis,hepatocellular carcinoma,and liver *** addition,it has also been linked to extrahepatic consequences,such as cardiovascular disease,diabetes,and various types of ***,only a small proportion of patients with mAFLD develop these ***,the identification of high-risk patients is *** fibrosis is the major determinant in developing these ***,liver biopsy is still considered the gold standard for the assessment of patients with *** of its invasive nature,among many other limitations,the search for noninvasive biomarkers for mAFLD remains an area of intensive *** this review,we provide an update on the current and future biomarkers of mAFLD,including a discussion of the associated genetics,epigenetics,microbiota,and *** also touch on the next wave of multiomic-based biomarkers.

关键词： Biomarkers metabolic(dysfunction)-associated fatty liver disease Scores

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Computational fluid dynamics simulation of gas dispersion in complex facilities using Kit Fox field experiments:Validation and statistical evaluation

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Chinese Journal of Chemical Engineering 2022年第4期35卷 412-423页

作者： Narjes Hemati Alam eslam Kashi Razieh Habibpour Department of Chemical Technologies Iranian Research Organization for Science and TechnologyP.O.Box 33535111TehranIran

Gas release and its dispersion is a major concern in chemical *** order to manage and mitigate the risk of gas dispersion and its consequences,it is necessary to predict gas dispersion behavior and its concentration at various locations upon ***,models and commercial packages such as Phast and ALOHA have been *** fluid dynamics(CFD)can be a useful tool to simulate gas dispersion in complex areas and *** validation of the models requires the employment of the experimental data from filed and wind tunnel *** appears that the use of the experimental data to validate the CFD method that only includes certain monitor points and not the entire domain can lead to unreliable results for the intended areas of *** this work,some of the trials of the Kit Fox field experiment,which provided a wide-range database for gas dispersion,were simulated by *** scenarios were considered with different mesh sizes,physical conditions,and types of *** results of the simulations were surveyed in the whole *** data matching each scenario was varied by the influence of the dominant displacement force(wind or diffusivity).Furthermore,the statistical parameters suggested for the heavy gas dispersion showed a dependency on the lower band of gas ***,they should be used with ***,the results and computation cost of the simulation could be affected by the chosen scenario,the location of the intended points,and the release type.

关键词： Gas dispersion simulation Computational fluid dynamics Complex terrain Obstructed flow

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Comparison of fixed area and distance sampling methods in open forests:case study of Zagros Forest,Iran

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Journal of Forestry Research 2016年第5期27卷 1121-1126页

作者： mehrdad mirzaei Amir eslam Bonyad University of Guilan

The main aim of this study was to evaluate methods for fixed area and distance sampling in the Zagros open forest area in western Iran. Basic forest management and planning required appropriate quantitative and qualitative information. Two sampling methods were compared on the basis of the actual means of characteristics derived from the 100 % survey. In total, 37 sampling plots were systematically installed with a grid of 100 m × 100 m in the study area. Density, crown canopy, and basal area of the stands were measured. The 100 % survey showed that tree density above 12.5 cm diameter at breast height was 68.04 stem ha-1, basal area was 15.16 m2 ha-1 and crown canopy percentage was 35.71% ha-1. The values for the traits determined by the two sampling methods differed significantly （P = 0.05）. When the time required for the methods was compared, transect sampling required less than systematic-random sampling. Therefore, the transect sampling method was the more economical method for the Zagros open forests. The transect sampling method was statistically defensible and practical for quantitating characteristics of the Zagros open forests.

关键词： Ilam - Systematic random sampling Transect sampling Zagros Forest

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Evaluating the efficiency of the Dong model in determining fire vulnerability in Iran’s Zagros forests

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Journal of Forestry Research 2019年第4期30卷 1447-1458页

作者： Sabri Baqer Rasooli Amir eslam Bonyad Department of Geography College of EducationUniversity of GarmianKalarKurdistan RegionIraq Department of Forestry Faculty of Natural ResourcesUniversity of GuilanSowmeh SaraIran

Recent fires in Iran’s Zagros forests have inflicted heavy,extensive losses to the environment,forests,villages,and forest inhabitants,resulting in a huge financial loss to the *** the increasing risk of fire and the resulting losses,it has become ever more necessary to design and develop efficient fire control and prediction *** present study utilizes the Dong model to develop a map of areas vulnerable to fire in the Zarivar lake forests as a representative sample of Zagros *** model uses as its inputs some of the most significant factors(such as vegetation,physiographic features,and the human component)that affect the fire occurrence and *** assigned weights to each factor based on the model,all maps were overlapped in the Arcmap and then the region was divided into five *** results showed that 74%of the region was located in three classes:highly vulnerable,vulnerable,and medially *** validate the proposed zoning map it was compared with a map based on real data obtained from previous *** results showed that 81%of fire incidents were located in highly vulnerable,vulnerable and medially vulnerable ***,the findings indicated a medium to a high degree of fire vulnerability in Zarivar Lake forests.

关键词： Dong model Fire incidents Zarivar lake Zoning

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Solvent extraction and separation of light rare earth elements (La, Pr and Nd) in the presence of lactic acid as a complexing agent by Cyanex 272 in kerosene and the effect of citric acid,acetic acid and Titriplex Ⅲ as auxiliary agents

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Journal of Rare Earths 2018年第3期36卷 317-323页

作者： eslam Kashi Razieh Habibpour Hesamoddin Gorzin Armin maleki Department of Chemical Technologies Iranian Research Organization for Science and Technology (IROST) Chemical Engineering Department School of EngineeringIslamic Azad University-Tehran North Branch

At present, the use of rare earth elements（REEs） has become an inevitable necessity in many modern industries. In general, liquid extraction is the best commercial method for extracting REEs due to its ability to control high volumes of liquids with electrical load. With the aim of improving a separation technology that would be superior to the existing extraction systems, the extraction behaviors of La（Ⅲ）,Pr（Ⅲ）, and Nd（Ⅲ） from an HCI medium with Cyanex 272 in the presence of the complexing agent lactic acid（HLac） and auxiliary agents citric acid（H3 Cit）, acetic acid（HAc）, and Titriplex Ⅲ have been *** effect of pH and lactic acid concentration has been examined. The use of lactic acid as a complexing agent leading to a high extraction of REEs with Cyanex 272 at pH = 5 was compared with systems without lactic acid. The results show that the use of acetic acid along with lactic acid leads to an increase in the extraction percentage of LREEs. While use of citric acid and Titriplex Ⅲ reduces the extraction percentage of LREEs. Finally, the presence of Titriplex Ⅲ together with lactic acid could lead to an increase in the separation factor of Pr and Nd.

关键词： Light rare earth elements(LREEs) Solvent extraction Cyanex 272 Lactic acid complexing agent Auxiliary agents Rare earths

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Effect of welding parameters on the heat-affected zone of AISI409 ferritic stainless steel

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International Journal of minerals,metallurgy and materials 2012年第10期19卷 923-929页

作者： eslam Ranjbarnodeh Stefanie Hanke Sabine Weiss Alfons Fischer Young Researchers Club(East Tehran Branch) Islamic Azad UniversityTehran 33955-163Iran materials Science and Engineering University of Duisburg-EssenDuisburg 47057Germany

One of the main problems during the welding of ferritic stainless steels is severe grain growth within the heat-affected zone （HAZ） In the present study, the microstmctural characteristics of tungsten inert gas （TIG） welded AISI409 ferritic stainless steel were investigated by electron backscattered diffraction （EBSD）, and the effects of welding parameters on the grain size, local misorientation, and low-angle grain boundaries were studied. A 3-D finite element model （FEm） was developed to predict the effects of welding parameters on the holding time of the HAZ above the critical temperature of grain growth. It is found that the base metal is not fully recrystallized. During the welding, complete recrystallization is followed by severe grain growth. A decrease in the number of low-angle grain boundaries is observed within the HAZ. FEm results show that the final state of residual sWains is caused by competition between welding plastic strains and their release by recrystallization. Still, the decisive factor for grain growth is heat input.

关键词： ferritic stainless steel welding heat affected zone recrystallization grain growth finite element method

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Geochemistry of magnetite in beach sands, stream sediments,and in situ magnetites in surrounding rocks at north Taiwan island

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Acta Geochimica 2022年第3期41卷 434-452页

作者： eslam mohammed Ali mitwally Bing-Sheng Yu Institute of mineral Resources Engineering National Taipei University of TechnologyTaipeiTaiwanRepublic of China Geology Department Faculty of ScienceAl Azhar UniversityAsyuˆtEgypt

The geochemistry of magnetite provides constraints on the source(s) of the magnetite and other ore minerals. In this study, we constructed a magnetite distribution map, compared the chemical composition of magnetite present in hard rocks with that present in sand beach and stream deposits to determine magnetite’s provenance,investigated relationships among different trace elements,examined variations in the concentrations of trace elements present in magnetite, and identified the type of studied magnetite. Laser ablation inductively coupled plasma mass spectrometry(LA-ICP-mS) and inductively coupled plasma mass spectrometry/inductively coupled plasma atomic emission spectroscopy was used to analyze samples available in small and large amounts, respectively. The average magnetite compositions of beach and river samples were substantially similar to those of andesite rocks,revealing that the magnetite samples may have originated from surrounding andesite rocks;this finding is consistent with the chemical composition of the samples analyzed using LA-ICP-mS. Some of the andesite rocks found in the study area were the primary source of magnetite aggregations in the beach sands and stream sands near or slightly away from these rocks. High Ti–V magnetites lie within the fields of Fe–Ti–V bearing magnetite and titanomagnetite(ulv?spinel). These titanomagnetites may be undergoing transformation to spinel minerals such as galaxite,gahnite, magnesiochromite, and chromite, which are characterized by the high concentrations of Al, Ti, mg, Cr,Ni, mn, and Zn. The positive correlation between Fe and Ti, Cr and Ni, and also the negative correlation between Fe and mg, mn and Zn can be attributed to various magnetite phases present in the study area. V, Co, mo, Nb, Ga, Sn,and Ta exhibited a positive correlation with Fe and a negative correlation with Al. The positive correlation between Fe and these elements indicates the enrichment of these elements in the magnetite series. We observ

关键词： magnetite chemistry LA-ICP-mS Element incorporation multi variation diagram Distribution map North Taiwan

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