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Inter-population variabilities in seed mass and germination of Panicum turgidum and Pennisetum divisum in the desert of Kuwait

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Journal of Arid Land 2020年第1期12卷 144-153页

作者： Arvind BHATT narayana R BHAT Afaf AL-nasser María M CARÓn AndreaSAnTO Kuwait Institute for Scientific Research Safat 24885Kuwait Laboratory of Botanical Research(LABIBO) Faculty of Natural SciencesNational University of Salta-CONICETSalta 4400Argentina Independent Researcher Selargius 09047Italy

Understanding variability in seed germination among populations is essential for planning an effective germplasm collection for restoration and conservation *** knowledge of germination and dormancy patterns among populations of desert grasses is crucial for determining the potential of the species and populations to be used for restoration and conservation as well as forage *** in seed germination of Panicum turgidum Forssk and Pennisetum divisum(Gmel.)*** the desert of Kuwait was evaluated in different populations in May *** of seed germination(25 seeds and 4 replicates)was conducted for each population at night/day temperatures of 15℃/20℃and 20℃/30℃under the following light condition:continuous darkness or 12 h/12 h light/*** showed that seed masses of both species strongly varied according to their seed provenances,and both species produced heavier seeds in population with a higher soil electrical *** germination percentage considerably varied between two species,and the variation in *** was greater(17%–49%)than that of ***(72%–93%).Germination percentage in *** was greater at high temperature(20℃/30℃)than at low temperature(15℃/20℃).However,temperature regimes had no effect on germination percentage of *** *** germination time of both species exhibited significant inter-population *** result is especially relevant to assure the selection of the best population of each species and the regeneration success of the *** this,inter-population variability also provides valuable information for enhancing our understanding of the mechanisms that regulate seed germination and how they might be related to seed provenance.

关键词： desert grass seed germination inter-population variability seed provenance seed dormancy

A framework for an integrated unified modeling language

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Frontiers of Information Technology & Electronic Engineering 2016年第2期17卷 143-159页

作者： Mohammad ALSHAYEB nasser KHASHAn Sajjad MAHMOOD Information and Computer Science Department King Fahd University of Petroleum and Minerals

The unified modeling language(UML) is one of the most commonly used modeling languages in the software *** simplifies the complex process of design by providing a set of graphical notations,which helps express the objectoriented analysis and design of software *** UML is applicable to different types of systems,domains,methods,and processes,it cannot express certain problem domain ***,many extensions to UML have been *** this paper,we propose a framework for integrating the UML extensions and then use the framework to propose an integrated unified modeling language-graphical(iUML-g) ***-g integrates the existing UML extensions into one integrated *** includes an integrated diagram for UML class,sequence,and use case *** proposed approach is evaluated using a case *** proposed iUML-g is capable of modeling systems that use different domains.

关键词： Unified modeling language (UML) Integration Modeling System analysis and design

Optimal operation of energy at hydrothermal power plants by simultaneous minimization of pollution and costs using improved ABC algorithm

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Frontiers in Energy 2015年第4期9卷 426-432页

作者： Homayoun EBRAHIMIAn Bahman TAHERI nasser YOUSEFI Department of Engineering Ardabil Branch Islamic Azad University Ardabil 0451 Iran Young Researchers and Elite Club Ardabil Branch Islamic Azad University Ardabil 0451 Iran

The aim of this paper is simultaneous mini- mization of hydrothermal units to reach the best solution by employing an improved artificial bee colony （ABC） algorithm in a multi-objective function consisting of economic dispatch （ED） considering the valve-point effect and pollution function in power systems in view of the hot water of the hydro system. In this type of optimization problem, all practical constraints of units were taken into account as much as possible in order to comply with the reality. These constraints include the maximum and minimum output power of units, the constraints caused by the balance between supply and demand, the impact of pollution, water balance, uneven production curve con- sidering the valve-point effect and system losses. The proposed algorithm is applied on the studied system, and the obtained results indifferent operating conditions are analyzed. To investigate in various operating conditions, different load profiles in 12 h are taken into account. The obtained results are compared with those of the other methods including the genetfc algorithm （GA）, the Basu technique, and the improved genetic algorithm. Fast convergence is one of this improved algorithm features.

关键词： practical constraints of units pollution func-tion inlet steam valve up-ramp rate of units improvedABC algorithm

Ionic Conductivity in Gelatin-Based Hybrid Solid Electrolytes:The non-trivial Role of nanoclay

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Journal of Materials Science & Technology 2014年第11期30卷 1096-1102页

作者： Ali Ghadami nader Taheri Qazvini nasser nikfarjam Polymer Division School of ChemistryCollege of ScienceUniversity of Tehran Biomaterials Research Center (BRC) University of Tehran

In this study, the ionic conductivity behavior in hybrid gelatin-based transparent electrolytes including various types of nanoclays with different size, shape and surface properties was characterized. The effects of nanoclay type and nanoclay concentration as well as different experimental conditions, e.g., pH, temperature and crosslinking were also investigated. In general, the impedance spectroscopy results suggested a non- trivial role for nanoclay. Regardless of the nanoclay type, the ionic conductivity slightly increased first and then decreased by increasing the nanoclay concentration. Furthermore, among sodium montmorillonite （na＋MMT）, lithium montmorillonite （Li＋MMT）, laponite and hydrotalcite, the hybrid electrolytes prepared by Li＋MMT showed higher ionic conductivity. The results also showed that the chemical crosslinking along with sample preparation at optimum pH, where the gelatin chains might be efficiently adsorbed on exfoliated, negatively charged clay nanosheets, plays an important role. In comparison with the ionic conductivity of the neat sample at room temperature （～10-7 S cm-1）, a ten-fold increase was observed for the crosslinked sample containing 2 wt% of Li^＋MMT prepared at optimum pH 3.5. The conductivity behavior as a function of temperature revealed the obedience with the VogeI-Fulcher-Tammann （VFT） model for all samples, suggesting the important role of segmental motions in the ionic conductivity. Finally, a qualitative explanation was presented for the mechanism of the ionic conduction in gelatin-nanoclay hybrid electrolytes.

关键词： Gelatin Solid-state electrolytes Ionic conductivity Montmorillonitc Laponite Impedance spectroscopy

Effect of a chemical reaction on magnetohydrodynamic boundary layer flow of a Maxwell fluid over a stretching sheet with nanoparticles

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Particuology 2016年第6期14卷 154-161页

作者： Ahmed A. Afify nasser S. Elgazery Department of Mathematics Faculty of Science Helwan University Ain Helwan PO Box 11795 Cairo Egypt Department of Mathematics Faculty of Education Ain Shams University Roxy Heliopolis Cairo Egypt

The influences of the convective boundary condition and heat generation/absorption on magnetohydro- dynamic boundary layer flow of a Maxwell fluid over a stretching surface in the presence of nanoparticles have been numerically investigated. In the model, the physical mechanisms responsible for Brownian motion and thermophoresis with a chemical reaction are considered. Similarity equations are derived and then solved using the shooting method with the fourth-order Runge-Kutta integration scheme, The rates of heat and mass transfer are enhanced with a destructive chemical reaction and Blot number. The opposite influence is found with a generative chemical reaction in the presence of Brownian motion and the thermophoretic property.

关键词： Magnetohydrodynamics nanoparticle Maxwell fluid Boundary layer flow Chemical reaction

Is there any correlation between vitamin D insufficiency and diabetic retinopathy?

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International Journal of Ophthalmology(English edition) 2015年第2期8卷 326-331页

作者： Shokoufeh Bonakdaran nasser Shoeibi Endocrine Research Center Mashhad University of Medical Sciences Ghaem Hospital Retina Research Center Mashhad University of Medical Sciences

AIM: To determine a relation between vitamin D level,which is an inhibitor of angiogenesis, and diabetic retinopathy and its risk factorsMETHODS: In a clinic-based cross sectional study two hundred and thirty-five type 2 diabetic patients older than 20 y were selected. Patients were classified according to ophthalmologic examination as following:no diabetic retinopathy(nDR)(n =153), non-proliferative diabetic retinopathy(nPDR)(n =64) and proliferative diabetic retinopathy(PDR)(n =18). Study subjects were tested for fasting blood glucose, glycated hemoglobin A1C(Hb A1C), lipid profile, microalbuminuria, Hs CRP,IGF1, insulin(in patients without history of insulin taking)and 25 hydroxy vitamin D [25(OH) D] levels. Vitamin D insufficiency was defined according to 25(OH) D level less than 30 ng/m L. The relationship between diabetic retinopathy and serum 25(OH) D insufficiency was ***: The prevalence of diabetic retinopathy was34.8% in our patients. Long duration of diabetes,hypertension, poor glycemic control, diabetic nephropathy, hyperinsulinemia and insulin resistance were risk factors for diabetic retinopathy but 25(OH) D level was not significant different between nDR, nPDR and PDR groups. Correlation between 25(OH) D level and other known risk factors of diabetic retinopathy was not ***: This study did not find any association between diabetic retinopathy and its severity and vitamin D insufficiency. Vitamin D insufficiency is not related to risk factors of diabetic retinopathy.

关键词： diabetes retinopathy vitamin D insulin resistance

Spatiotemporal shoreline change in Boushehr Province coasts,Iran

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Journal of Oceanology and Limnology 2020年第3期38卷 707-721页

作者： Saeed ZEInALI nasser TALEBBEYDOKHTI Maryam DEHGHAnI Department of Civil&Environmental Engineering School of EngineeringShiraz UniversityShiraz 71348-51156Iran

Since coastal areas have highly dynamic nature and are one of the most beneficial regions of civilizations,it is of great significance to understand their characteristics and *** in shorelines in the form of accretion and erosion can leave devastating effects on businesses and cities located along the *** this study,we statistically calculated the tendency of shoreline changes by processing and analyzing historical satellite images of Boushehr Province,*** show that these shores have experienced both sedimentation and erosion in the past 30 *** shoreline movement presents more than 350 m of erosion and 650 m of accretion,which are corresponded to change rates of almost 12 and 22 m/a,*** of shoreline changes are calculated from regression methods including end point rate,linear regression rate,weighted linear regression,and least median of *** best-performed method is applied to predict the shoreline position in 2050 and *** locations of excessive changes are identified for the predicted shorelines,which should be dealt with properly.

关键词： digital shoreline analysis system satellite image accretion and erosion linear regression sediment Boushehr Province

Improving low-voltage ride-through capability of a multimegawatt DFIG based wind turbine under grid faults

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Protection and Control of Modern Power Systems 2020年第1期5卷 390-402页

作者： Mohamed nadour Ahmed Essadki Tamou nasser Research Center of Engineering and Health Science and Technologies(STIS) High Normal School of Technical Education(ENSET)Mohammed V UniversityRabatMorocco Research Center of Engineering and Health Science and Technologies Higher National School of Computer Science and Systems Analysis(ENSIAS)Mohammed V UniversityRabatMorocco

Large integration of doubly-fed induction generator(DFIG)based wind turbines(WTs)into power networks can have significant consequences for power system operation and the quality of the energy supplied due to their excessive sensitivity towards grid *** voltage dips,the resulting overcurrent and overvoltage in the rotor circuit and the DC link of a DFIG,could lead to the activation of the protection system and WT *** potentially results in sudden loss of several tens/hundreds of MWs of energy,and consequently intensifying the severity of the *** paper aims to combine the use of a crowbar protection circuit and a robust backstepping control strategy that takes into consideration of the dynamics of the magnetic flux,to improve DFIG’s Low-Voltage Ride Through capability and fulfill the latest grid code *** the power electronic interfaces are protected,the WTs also provide large reactive power during the fault to assist system voltage *** results using Matlab/Simulink demonstrate the effectiveness of the proposed strategy in terms of dynamic response and robustness against parametric variations.

关键词： Wind turbine DFIG Grid faults Crowbar protection Backstepping control Low-voltage ride through

An expeditious and one-pot synthesis of unsymmetrical 2,5-disubstituted-1,3,4-oxadiazoles under microwave irradiation and solvent-free conditions

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Chinese Chemical Letters 2008年第10期19卷 1143-1146页

作者： nasser Montazeri Kurosh Rad-Moghadam Chemistry Department Azad University of TonekabonTonekabon 46841-61167Iran Chemistry Department University of GuilanRashtP.O.Box 41335-1914Iran

A one-pot synthesis of some unsymmetrical 2,5-disubstituted-1,3,4-oxadiazoles via cyclocondensation of benzoylhydrazines with orthoesters under solvent-free and microwave conditions are described here. The reaction is efficiently catalyzed by silica- supported sulfuric acid as it provided the title compounds in high yields and relatively short times. The catalyst is reusable and can be applied several times without considerable decrease in the yields and rates of the reactions.

关键词： 2,5-Disubstituted-1,3,4-oxadiazoles Silica-supported sulfuric acid Solvent-free Microwave Orthoester