Crystal structure of 1,1-dimethyl-3-(2-phenylethyl)urea محمد بطاح الشمري
1,1-Dimethyl-3-(2-phenylethyl)urea was synthesized from reaction of (2-phenylethyl)amine with dimethylcarbamoyl chloride (1.1 mole equivalents) in the presence of triethylamine (1.4 mole equivalents) in dichloromethane under reflux for 1 h. Recrystallization using a mixture of ethyl acetate and diethyl ether (1:3 by volume) gave the title compound (99%) as colourless crystals, mp 89–90 °C (lit. 88–90 °C ; 81–82 °C.
Investigating EFL Learners Attitude Towards Instructional Technolgy محمد علي قاسم
An Investigation of Assessment Practices in an EFL Program محمد علي قاسم
Evaluation of Collection efficiencies and related parameters of some ionization chambers محمد عبد الرحمن شقير
Evaluation of the collection efficiency of the ion chamber is very important for every application which requires accurate radiation quantity determination such as radiation therapy applications. The values of the effective electrode spacing introduced in the Boag's collection efficiency formula should be determined accurately, and ion recombination of some ion chambers of different types should be evaluated numerically when operating in continuous and pulsed radiation. It is proposed that consistent simulation of the internal surface of the ion chamber could be achieved if the chamber volume is divided into small volumes, hence accurate determination of electrode spacing may be achieved. Chambers included in this propodsal are cyliderical. spherical, and plane-parallel chambers. Some other related parameters should be included such as back diffusion current determination and ion multiplication effect. evaluation of collection efficiencies of these ion chambers should be performed in continuous and pulsed radiation as well and for a wide spectrum of applied potential values.
Use of Heavy Oil Fly Ash (HFO) for Geopolymer Cement Production محمد عبد الرحمن شقير
Abdulkarim M. Alqahtani, Ibrahim A. Aldawood, Mohammed Shqair, Montserrat Zamorano Toro, Mazen Alshaaer Use of Heavy Oil Fly Ash (HFO) for Geopolymer Cement Production. Applied Mathematics and Materials ,Proceedings of the 8th International Conference on Materials Science (MATERIALS '15) , Italy,November 7-9, 2015
Impedimetric biosensor for serodiagnosis of canine L.infantum leishmaniasis أسامة مختار ورغي
visceral leishmaniasis (VL) is a severe disease that occurs in different mammalian species, including the human population. It is an important emerging parasitic disease found in 88 countries with a total of 200 million people at risk. It is caused by hemoflagellate protozoa belonging to the Leishmania genus and transmitted by the bite of phlebotomine sand flies. Canines are considered as the main urban reservoir for Leishmania spp. The monitoring of canine visceral leishmaniasis (CVL) is important to control the parasite transmission to man. However, classic laboratory techniques for the diagnosis of leishmania are usually time consuming and requires specialized skills and high cost. Thus, the development of practical and real-time methods to detect quantitatively the reaction antigen– antibodies in real time without labels or reagents is desirable. Biosensors, a judicious combination of signal transducers and bio-components, are emerging as a crucial alternative to conventional methods for the detection of pathogens. Biosensors utilizing immunological methods are particularly attractive for pathogenic organisms detection since they do not require large sample volumes or toxic solvents for analysis; they require minimal sample preparation, low reagent consuming, have high specificity in complex medium and have the potential for miniaturization, portability, and automation. In particular, electrochemical immuno-sensors have been successfully applied for immuno-detection of pathogens. In this project, electrochemical impedance spectroscopy technique will be used for canine leishmaniasis serodiagnosis using soluble Leishmania Antigens (SLA) as biological support. A carboxylic acid terminated alkanethiol monolayer will be used to provide a suitable interface for the covalent immobilization of SLA via EDC/NHS as coupling reagent. The antigen will be covalently linked through their primary amine residues to the activated...
شروط المطابقة وفقا للمادة 35 من اتفاقية الأمم المتحدة للبيع الدولي للبضائع 1980م ياسمين محمد يونس
يتناول البحث أحد أهم التزامات البائع في عقد البيع الدولي للبضائع بموجب أحكام اتفاقية فينا 1980م, وهو الالتزام بمطابقة المبيع , حيث تلزم المادة 35 البائع بتسليم بضائع للمشتري مطابقة لشروط ومواصفات العقد والشروط الواردة في الاتفاقية.
بحيث تطابق البضائع المسلمة للمشتري من حيث الكمية والنوعية ما جاء في عقد البيع من شروط ومواصفات, وفي حال عدم وجود تفاق خاص في العقد بخصوص شروط البضائع ومواصفاتها يجب ان تكون البضائع مطابقة لشروط والمواصفات الواردة في اتفاقية فينا.
Antioxidant activity of mildbone and mildbenone secondary metabolites of Erythrina mildbraedii Harms: A theoretical approach الحسن أنوار
El Hassane Anouar. Computational and Theoretical Chemistry, Accepted (Nov 2015), In press.
Flavanone mildbone and its isomeric chalcone mildbenone isolated from an African Erythrina species herms, E. mildbraedii showed significant antioxidant activity to scavenge 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH). To shed light and explain the high antioxidant activity of mildbone compared with mildbenone, density functional theory (DFT) calculations have been carried out at the B3P86/6-311 G(d,p) and MPWB1K/6-311 G(d,p) levels of theory. The solvent effects were taken into account implicitly using polarizable continuum model (PCM). The results showed that the high antioxidant activity of mildbone is mainly related to the second bond dissociation enthalpy BDEd of a second hydrogen atom transfer from i-OH phenoxyl radical to the free radical. Thermodynamic and kinetic results showed that DPPH and peroxyl •OOCH3 free radicals scavenging by mildbone and mildbone mainly proceed through a proton-coupled electron transfer (PC-ET) mechanism.
Analysis & Treatment of Water and Sediment عمر أجوييد
My doctoral dissertation was conducted under the direction of Prof. Nicolas Marmier, and looks at the use of mineral additives as a adsorbents to reduce the mobility of heavy metals during storage of sludge dredging contaminated. In my research, clay minerals (kaolinite and illite) and metal oxy-hydroxides (hematite, goethite and alpha-alumina) are being considered for this study given their natural occurrence in sediments and their high retention capacity. The results show that the addition of amendments could be a successful technique for stabilization of chromium and other metals in contaminated sediment
"Women cannot write": Virginia Woolf and the inferiority of Women in Modern Literature مشاعل ابراهيم الحماد
This paper has been presented in the in-house seminar at King Saud University. This paper deals with Woolf's response to the patriarchal attitude toward female artists. It starts with offering a brief historical background regarding the early modern period and the state of women at that time. It discusses the events that led to changes in the Victorian patriarchal society. Then, it responds to the claims raised by anti-feminists who believe women cannot write like men, and that female artists are inferior to male artists.