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الضمير المستتر , دراسة وصفية تحليلية
No full textالضمير المستتر دراسة وصفية تحليلية:
في هذا البحث سأتحدث عن قضية مهمة من قضايا النحو العربي , وهي : قضية الضمير المستتر , وذلك من حيث نشوء الفكرة , والألفاظ التي أطلقت عليه , ولماذا قال النحويون بوجوده ؟ وعلامات وجوده , ومواضع استتاره , وآراء النحويين فيه قديما وحديثا , ثم أوردت النتائج التي توصل إليها البحث
Apical accuracy of root canal fillings performed using the root ZX as the sole method of working length determination.
No full textThis is an in vivo investigation that was undertaken to evaluate the apical accuracy of root canal fillings performed using the Root ZX apex locator as the sole method to determine the root canal length during root canal treatment and to compare them with conventional radiographic method. Twenty-eight root canals from ten orthodontic patients scheduled for bilateral extractions of their premolars were used in this study. One premolar received root canal therapy using the Root ZX to determine the working length without using active root canal treatment radiographs. The contra-lateral premolar was treated following routine root canal treatment procedures using multiple radiographs (pre-operative, working length, master apical file, master cone and final radiographs). The teeth were then extracted, decalcified, cleared and the accuracy of the root filling length was evaluated. The results demonstrated that the apical accuracy of root canal fillings performed using the Root ZX only were satisfactory in 86% of the cases compared with 57 % using the conventional method, however, the difference was not statistically significantly (P=0.135). It was concluded that both techniques produced root canal fillings with similar apical accuracy.King Saud Universit
الغرامات في نظام المنافسات والمشتريات الحكومية السعودي: دراسة تحليلية
No full textيتناول هذا البحث موضوع أحكام الغرامات (التأخير والتقصير وتكاليف الإشراف) في عقود المشتريات الحكومية السعودية وذلك بإجراء دراسة تحليلية في إطار نظام المنافسات والمشتريات الحكومية، ولائحته التنفيذية، وتوضيح موقف القضاء الإداري في المملكة ممثلا في ديوان المظالم من هذه الغرامات، وكذلك استشراف الواقع العملي المطبق في المملكة. تهدف الغرامات إلى تحديد أقصى قدر من الانضباط في تنفيذ العقد الإداري في الوقت المتفق عليه، وحتى تكون الغرامة دافعاَ للمقاول لإنهاء العقد في وقته المحدد ووفقا لشروط ومواصفات العقد حتى لا توقع عليه الغرامة؛ فهي بالتالي نوع من الجزاء أعطى النظام الجهات الإدارية الحق في النص عليها عقودها لحث المتعاقد معها على انجاز التزاماته التعاقدية، وحرصاً على حسن سير المرافق العامة بانتظام واضطراد، فقصد الجهة الإدارية دفع المتعاقد مع جهة الإدارة لتنفيذ التزامه أكثر من قصدها التعويض عن الضرر الذي لحق بها، ولهذا تكثر الإعفاءات من جهة الإدارة من تطبيق هذه الغرامة، لأن التعويض بمعناه العام ليس هو القصد الأساسي منها. وقد حرص ديوان المظالم على عدم إخلال الجهات الإدارية بالقواعد العامة للغرامات المالية ولذا قرر في بعض أحكامه أنه لا يجوز المغالاة في تحديد مقدار الغرامة الجزائية في عقود الصيانة والنظافة بالشكل الذي يؤدي تطبيقه إلى استغراق مستحقات المتعهد. كما قضى أنه يجوز للديوان في العقود الإدارية التدخل لتعديل تلك الغرامات بما يحقق العدالة وإنقاص قيمة الجزاءات إلى الحد المعقول الذي يتفق وأسعار العقد، بالإضافة إلى انه يجوز للديوان تخفيض قيمة الغرامة إذا استبان له أن التقدير كان مبالغاً فيه إلى حد لا يتناسب مع مدة التأخير. وقد اختتم البحث بعدد من النتائج التي من أهمها : أن الغرامات المالية توقع على المتعاقد مع الجهة الإدارية فقط، وليس على الجهة الإدارية، فهي غرامات أحادية تستأثر جهة الإدارة بتطبيقها على المتعاقد معها، بمعنى أنها تفرض على الطرف المتعاقد مع الحكومة، وبالتالي لا يستطيع المتعاقد أن يفرض غرامة تأخير على الجهة الإدارية إذا تأخرت في دفع مستحقاته المالية، أو تأخرت في تسليمه الموقع، أو ما شابه ذلك. كذلك فانه لا يشترط وقوع ضرر حتى يتم تطبيق الغرامة، لأن الغرامات المالية ليست تعويضاً يجبر ضرر الإدارة، وإنما غرامات مالية تطبق مباشرة بمجرد تأخير المتعاقد أو تقصيره في تنفيذ التزاماته بقرار من الإدارة. كذلك قيّد النظام إلغاء الغرامة بالسلطة التقديرية للإدارة سواء كانت وزارة المالية، أو رئيس الجهة الإدارية رغم انه يفترض ألا يعفى المتعاقد من الغرامة بسبب القوة القاهرة أو بسبب لا دخل له فيه، وإنما تسقط الغرامة مباشرة من الجهة الإدارية بمجرد وقوعها لأن المتعاقد لم يكن السبب في حدوثها
Fluidization of nano-powders: Effect of sound vibration and pre-mixing with group A particles
No full textThe use of sound vibration as well as mixing of particles is investigated in this paper for improving the fluidizability of nano-powders. Amorphous anhydrous silicon dioxide, Aerosil 200, widely used in paint and pharmaceutical industries, was fluidized with air at superficial gas velocities as high as 25. cm/s. In the first part of the study, the bed was subjected to sound at 125. dB at a frequency 200. Hz. In the second part, a carefully selected additive material of the Geldart group A classification, presently sand, was added to the bed in relatively small proportions of 3, 6 and 11. wt.%. For the in situ monitoring of the fluidization dynamics, pressure fluctuations were acquired at a sampling frequency of 200. Hz using a fast-response sensitive-pressure transducer along the test section of the column located 11. cm and 23. cm above the distributor. The data thus obtained were analyzed in both time and frequency domains, and used for the reconstruction of system attractors and the determination of its principal eigenvalues. The combination of quantitative tools and digital images of the bed showed that both sound vibration and particle mixing improved the fluidization. The sound-assisted fluidization resulted in the de-agglomeration of the nano-powder, resulting in an expansion of the bed that was reflected in smaller values of the average pressure-drop. The fluidization was characterized by a strong periodic behavior. The addition of small proportions of group A powder, on the other hand, initially increased the average pressure-drop due to the concomitant rise in the bulk density, and led to a bubbling-like behavior reflected in more turbulent and less periodic fluidization. While the widely used sound-assisted fluidization exhibited a limited range of bed operation owing to the high elutriation rates of the bed material, not much limitation was observed for the case of particle mixing. This study showed that the use of appropriate small proportions of inert group A particles may be advantageous in improving the fluidization of nano-powders compared to the use of the energy intensive sound vibration. © 2010 Elsevier B.V
Control of intravenous medication wastage at a teaching hospital in Saudi Arabia.
No full textTo investigate the intravenous (IV) medication wastage within the inpatient pharmacy services at a teaching hospital, and to highlight the main causes for such waste and propose a policy to minimize wastage based on the study findings. For a one month period starting from September until October 2009, the returned and unused IV medications to the inpatient pharmacy in a teaching hospital at King Khalid University Hospital of King Saud University, Riyadh, Kingdom of Saudi Arabia were observed daily. Data were collected and evaluated. The causes of this problem were analyzed. Approximately 265 items of IV medication were collected during the study period. Antibiotics preparations (77%) were the most unused and wasted. Medication discontinuation (60%) was the main cause for such wastage. The problem of IV medication wastage was noticed and investigated. The main causes of such problems were specified, and a program to minimize the wastage was proposed. Further study with more data for longer time is required, followed by an evaluation of the impact of applying the proposed program
Comparative bioavailability study of cefuroxime axetil (equivalent to 500 mg cefuroxime/tablet) tablets (Zednad® versus Zinnat®) in healthy male volunteers
No full textThis study was performed to investigate the bioequivalence of cefuroxime axetil tablets between a generic test product (A) Zednad® Tablet (500 mg cefuroxime/ tablet, Diamond Pharma, Syria), and the Reference Product (B) Zinnat® Tablet (500 mg cefuroxime/tablet, GlaxoSmithKline, Saudi Arabia). The bioavailability study was carried out for 24 healthy male volunteers. The subjects received 1 Zednad® Tablet (500 mg/ tablet) and 1 Zinnat® Tablet (500 mg/tablet) in a randomized, two-way crossover design fashion on 2 treatment days, after an overnight fast of at least 10 h, with a washout period of 7 days. 24 volunteers plus 2 alternatives completed the crossover. The bioanalysis of clinical plasma samples was accomplished by HPLC method, which was developed and validated in accordance with international guidelines. Pharmacokinetic parameters, determined by standard non-compartmental methods, and ANOVA statistics were calculated using SAS Statistical Software. The significance of a sequence effect was tested using the subjects nested in sequence as the error term. The 90% confidence intervals for the ratio between the test and reference product pharmacokinetic parameters of AUC0→t, AUC0→∞, and Cmax were calculated and found to be within the confidence limits of 80.00 - 125.00% for AUC0→t, AUC0→∞ and Cmax. The study demonstrated that the test product (A) was found bioequivalent to the reference product (B) following an oral dose of 500 mg tablet. Therefore, the two formulations were considered to be bioequivalent
فاعلية استخدام موقع ويب تعاوني " ويكي" في إنجاز الطلاب المعلمين
No full textسعت الدراسة للتعرف علي فاعلية استخدام موقع ويب تعاوني " ويكي" في إنجاز الطلاب المعلمين و إتجاههم نحو مقرر المتاحف والمعارض التعليمية معوقات توظيف تكنولوجيا التعليم بالجامعات العربية ، بالتطبيق علي عينة من طلاب مقرر المتاحف و المعارض بكلية المعلمين – جامعة الملك سعود قوامها 41 طالبا ، وتوصلت الدراسة إلي تفوق المجموعة التجريبية التي درست بإستخدام مواقع الويب التعاونية مقارنة مع المجموعة الضابطة التي درست بالطريقة التقليدية ، وأوصت الدراسة بضرورة تفعيل استخدام مواقع الويب التعاونية في التعليم الجامعي ، و توفير الإمكانات المادية و الفنية الداعمة للتعلم التعاوني القائم علي الويب
Properties of natural pozzolan and its potential utilization in environmental friendly concrete
No full textIn Saudi Arabia, locally available natural pozzolanic material has the potential for use in environmental friendly concrete as a partial cement replacement. Local natural pozzolan was incorporated in concrete as a partial cement replacement to study the effect of replacement level, natural pozzolan fineness and its source. Chemical and physical properties of local natural pozzolan, properties of fresh concrete, compressive strength development, chloride permeability, and porosity of concrete incorporating local natural pozzolanic material as a partial cement replacement is presented. The influence of curing on the properties of concrete containing natural pozzolan and the X-ray diffraction analysis are reported. It was observed that regardless of its different sources, chemical and physical properties of local natural pozzolan are similar and conforms to the requirements of ASTM C 618, Class N. Concrete containing up to 15% natural pozzolan matches with the mix containing 20% fly ash, which is very close to the plain concrete. Higher dosages of this natural pozzolan can be utilized for economical and environmental benefits. This research is the first of its kind that addresses the investigation on Saudi natural pozzolanic material
Behavior of FRP-confined concrete after high temperature exposure
No full textThis paper presents the results of an experimental program to investigate the effect of high temperature on the performance of concrete externally confined with FRP sheets. For this purpose, a two-phase experimental program was conducted. In the first phase, 42 standard 100 × 200 mm concrete cylinders were prepared. Out of these specimens, 14 cylinders were left unwrapped; 14 specimens were wrapped with one layer of CFRP sheet; and the remaining 14 specimens were wrapped with one layer of GFRP sheet. Some of the unconfined and FRP-confined specimens were exposed to room temperature; whereas, other cylinders were exposed to heating regime of 100 °C and 200 °C for a period of 1, 2 or 3 h. After high temperature exposure, specimens were tested under uniaxial compression till failure. The test results demonstrated that at a temperature of 100 °C (a little more than the glass transition temperature (Tg) of the epoxy resin), both CFRP- and GFRP-wrapped specimens experienced small loss in strength resulting from melting of epoxy. This loss of strength was more pronounced when the temperature reached 200 °C. In the second phase of the experimental program, three 100 × 100 × 650 mm concrete prisms were prepared and then overlaid by one layer of CFRP and GFRP laminates for conducting pull-off strength tests as per ASTM D4541 - 09. The objective of this testing was to evaluate the degradation in bond strength between FRP and concrete substrate when exposed to elevated temperature environments. One prism was exposed to room temperature whereas the other two specimens were exposed to heating regime of 100 °C and 200 °C for a period of 3 h. It was concluded that a significant degradation in the bond strength occurred at a temperature of 200 °C especially for CFRP-overlaid specimens. © 2010 Elsevier Ltd. All rights reserved