In the present work, the surface properties of mixed binary surfactants containing sodium dodecylbenzene sulfate (SDBS) and Tween 80 (TW80) surfactants in aqueous solutions were studied at temperature 293 K using surface tension measurements. The critical micelle concentration (cmc) magnitude for both individual surfactants and their mixtures were established the obtained results revealed that the magnitude of cmc of the mixtures are less than the magnitude of individual surfactants and decrease with the increase in Tween 80 percent in solution which indicate the nonideal mixing of the two surfactants. The values of molecular interaction parameters and the mole fraction of surfactants in the micelle (X1) were calculated on the basis of Rubingh’s model and showed that the interaction parameter is always negative but at 0.9 mole fraction of TW80 surfactant (α1) is positive
This study aims to examine the sources of organizational power prevailing among the academic leaders at the University of Tabuk from the faculty members’ viewpoint. The purposes behind such an aim are: to reveal the level of administrative and technical institutional creativity, the nature of the relationship between the reality of organizational power and the level of institutional creativity, and to disclose statistically the significant differences between the averages of faculty members’ responses attributed to the demographic variables (gender, years of experience, academic degree). The study used the descriptive approach, both survey and correlational. A questionnaire was used to collect data from a simple random sample o
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Abstract:
The models of time series often suffer from the problem of the existence of outliers that accompany the data collection process for many reasons, their existence may have a significant impact on the estimation of the parameters of the studied model. Access to highly efficient estimators is one of the most important stages of statistical analysis, And it is therefore important to choose the appropriate methods to obtain good estimators. The aim of this research is to compare the ordinary estimators and the robust estimators of the estimation of the parameters of
... Show MoreThe possibility of using activated carbon developed from date palm seeds wastes as a permeable reactive barrier (PRB) to remove copper from polluted shallow groundwater was investigated. The activated carbon has been developed from date palm seeds by dehydrating methods using concentrated sulfuric acid. Batch tests were performed to characterize the equilibrium sorption properties of new activated carbon in copper-containing aqueous solutions, while the sandy soil (aquifer) was assumed to be inert. Under the studied conditions, the Langmuir isotherm model gives a better fit for the sorption data of copper by activated carbon than other models. At a pilot scale, One-dimensional column experiments were performed, and an integrated model ba
... Show MoreLet M is a Г-ring. In this paper the concept of orthogonal symmetric higher bi-derivations on semiprime Г-ring is presented and studied and the relations of two symmetric higher bi-derivations on Г-ring are introduced.
تعرضت المواقع الاثریة في الع ا رق الى النبش والتخریب،وقد أدى ذلك الى أستخ ا رج أعداداً كبیرة من النصوص المسماریة وتهریبها الى خارج الع ا رق. ومن ضمنها نصوص مدینة أ ري- ساكرك، فقد درست مجموعة من هذه النصوص والبالغ عددها ( ١١٥٩ ) نصاً التي نش رت في في هذا البحث قمنا بد ا رسة ( ٤) نصوص مصادرة لصالح المتحف .(Nisaba مجلد ( 15 الع ا رقي ذات مضامین أقتصادیة تتعلق بالحیوانات،ارخت بین السنة الثانیة والاربعین من حكم الملك شولكي وحت
... Show MoreThe wear behavior of alumina particulate reinforced A332 aluminium alloy composites produced by a stir casting process technique were investigated. A pin-on-disc type apparatus was employed for determining the sliding wear rate in composite samples at different grain size (1 µm, 12µm, 50 nm) and different weight percentage (0.05-0.1-0.5-1) wt% of alumina respectively. Mechanical properties characterization which strongly depends on microstructure properties of reinforcement revealed that the presence of ( nano , micro) alumina particulates lead to simultaneous increase in hardness, ultimate tensile stress (UTS), wear resistances. The results revealed that UTS, Hardness, Wear resistances increases with the increase in the percentage of
... Show Moreتكمن مشكلة البحث في أن كليات التربية عامةً وكلية التربية /ابن الهيثم خاصة ما زالت تسير وفق أنماط إدارية تقليدية وأن هناك شكوى تلهج بها الألسن في المجتمع المحيط بأن المخرجات التعليمية لا توازي تطلعات المجتمع وتوجهاته المستقبلية، كذلك الأهمية لتطبيق معايير ضمان جودة تحقق المستوى المطلوب لهذه الكلية أسوة بالمعايير العالمية، إذ هدف البحث في معرفة واقع معايير ضمان الجودة في الكلية والانتقال إلى رؤية مستقبلية ل
... Show MoreUrine samples had been gathered from females living in Baghdad city. The sample consisted of 30 females who suffered from U.T.I (Urinary tract infections) and 20 healthy females. The type of urine U.T.I was specified by the emergency lab in Al-Kindy hospital, and alpha tracks were determined by the nuclear track detector CR-39. The concentrations of alpha in 30 urine samples taken from females who had U.T.I ranged from 0.327ppm-1.583ppm, with an average of 0.94965 ppm. The maximum value 1.583 ppm is belonging to females with an aged 57 years old. The results of healthy female concentration ranged from 0.022 ppm-0.459ppm with an average of (0.30855ppm). The findings revealed that alpha emitter concentrations differed from woman to woman,
... Show Moreاعتمدت الدراسة على (65) نصاً ذات مضامين اقتصادية، تم اختيارها من المتحف العراقي من المجموعة ماتعرف بالمصادرة، ومن خلال دراسة النصوص ومقارنتها مع نصوص منشورة من سلالة أور الثالثة تبين أنها تعود الى العصر نفسه استناداً الى الصيغ التاريخية الواردة فيها، اذ ذكرت سنوات حكم اَخر ثلاثة ملوك هم أمارسين وشوسين وأبي سين، كما أمكن من خلال الدراسة أيضاً وأستناداً الى أسماء الاشهر وأسماء الاشخاص الواردة فيها تحديد عائديت
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