زينب بغلول, شايب قدادرة

كلية العلوم الإنسانية والاجتماعية-جامعة 8 ماي 1945 قالمة · الجزائر

Mounir Boussahel , Khedidja Ben guesmia , Soumia Allaoua

كلية العلوم-جامعة محمد بوضياف - المسيلة · الجزائر

Dans ce travail, nous avons éssayé d'obtenir une expansion accéléréede l'univers selon ce qui a été prouvé par les observationsastronomiques actuelles, et à travers le diagramme de Hubble dessupernovae, où nous avons étudié l'univers en s’appuyant sur le modèlestandard cosmique, le modèle Lambda - CDM (Lambda - matière noirefroide) où la constante cosmologique a été liée à l'énergie du vide, ce quisignifie que l'univers est en expansion accélérée, en considérantl'énergie noir comme une constante cosmique

علي بوجاهم

جامعة محمد خيضر - بسكرة · الجزائر

احمد عزي, احمد عيش, نادية سيفون

كلية العلوم الانسانية والاجتماعية-جامعة محمد بوضياف - المسيلة · الجزائر

إن الاتصال الشخصي كعملية اتصالية تستخدمها العلاقات العامة بصفة عامة في جميع الإدارات والمنشآت هو أداة مهمة وفعالة لها لتحقيق أهدفها المسطرة فميدان العلاقات العامة ميدان كبير جدا يحتاج إلى أنواع متعددة من الاتصالات وأهم اتصال تحتاجه العلاقات العامة لعملها هو الاتصال الشخصي بجميع وسائله وقد احتلت المقابلات الشخصية المرتبة الأولى كوسيلة من وسائل الاتصال في ميدان العلاقات العامة، حيث تفوقت نسب استخدام وسائل الاتصال الشخصي على وسائل اتصال أخرى، إذ بلغ مجموع نسب استخدام وسائل الاتصال الشخصي حوالي 70% بينما بلغ مجموع نسب استخدام وسائل اتصال أخرى حوالي 30%، منهم العاملين في إدارات العلاقات العامة يرون أن الاتصال الشخصي أهم نشاط تقوم به إدارتهم، وقد أظهرت الدراسة أن الغالبية العظمى من العاملين بالإدارة هذا الذكور وكذا أوضحت الدراسة أن متوسط الخبرة في المؤسسة ، قليل جدا، كما أوضحت الدراسة أهمية العلاقات العامة أهمية مطلقة وأن الأهداف التي تسعى إلى تحقيقها وفق لأراء العاملين هي الفوز بثقة الجمهور الخارجي وحتى تحقيق هذا الهدف الرئيسي يجب الاستعانة أو الاعتماد على الاتصال الشخصي كوسيلة أساسية لذلك توصلت الدراسة إلى عدم إيمان الإدارة بالبحث كوظيفة أساسية من وظائف العلاقات العامة و أوضحت الدراسة أن أهم وسائل الاتصال بالجماهير الداخلية وكذا الخارجية المقابلات الشخصية أي الاتصال الشخصي كما أظهرت الدراسة أن دور العاملين في المنشأة يتمحور أساسا على وظيفة الاتصال.

ام الخير بالاحسني, بشير قدار, سهام مبروك

كلية علوم الطبيعة والحياة-جامعة ابن خلدون – تيارت · الجزائر

L'humidité du sol joue un rôle crucial dans l'agriculture. Un bon équilibre d'humidité est essentiel pour assurer la croissance et le rendement des culturesL’objectif de notre travail est développement une méthodologie pour cartographie humidité de sol a la région de Tiaret ( SIDI ABED ,SOUGEUR) à l’aide de la télédétection et le système d’information géographique (SIG).Pour atteindre notre objectif, nous avons utilisé deux logiciels SNAP pour visualiser et traiter et analyse les images satellitaires de sentinelle 02 et Qgis pour réaliser des cartes de différents indices.Les deux logiciels utilisés facilitent beaucoup plus et avec une précision les résultats avec un gain du temps

Shahinaze Abdalla Higazy Abdalla , Abdalsalam Abdallah Dafallah Mohamme

كلية الدراسات العليا-جامعة السودان للعلوم والتكنولوجيا · السودان

This work was conducted in the White Nile area of Alhebika village near Algettina city to determine the quality of the water.Four samples were taken from each of the three sources of water (Well, Biara, Tap) to examine the quality of drinking water in the region in February for four consecutive weeks one week per sample The twelve samples were analyzed at Almnara Water station in Umdurman-sudan. The average value of analysis of the well, biara and tap are respectively ,as follows ; The pH (8.44, 8.41, 8.05); electrical conductivity (737, 554.25, 534) microscimens per centimeter; total dissolved solids (406.26, 304.77, 294.15) mg /L ; turbidity (0.252, 0.157, 0.345); alkalinity (249.5, 245, 209.75) and water hardness (12, 77.2 5,59.5); calcium (0, 16, 10.4); magnesium (2.88, 8.94, 8.04); chloride (17.25, 13, 11.5) and fluoride (1.09, 0.54, 0.917).The study compared our findings with WHO specifications. Most outcomes within the allowable limit and some exceeding the allowable limit, such as alkalinity and PH.

شيماء محمد أبو عيان , محمد حمدان

كلية الهندسة-جامعة الإمارات العربية المتحدة · الامارات

This study aims to analyze the cooling performance of phase change materials (PCMs) integrated into metallic heat sinks (HSs) both experimentally and numerically. For the experimental part of the study, a test setup has been constructed to test PCM integrated heat sinks. The heat sinks are prepared as metallic containments having fins with fixed inter-fin spacing. The volume between the heat sink fins is filled with PCM namely: a paraffin wax, salt hydrate-calcium chloride and milk-fat, then the whole system is sealed for testing under various heat loads at 4W, 6W, 8W and 10W. Four modes of operation are experimentally tested in this study: HS under natural convection, HS integrated with PCM under natural convection, HS under forced convection, and HS integrated with PCM under forced ventilation. The temperature of heat generating surface and the heat sink surface are monitored over time to evaluate the PCM thermal performance. From the results, the time lag and temperature drop in case of with PCM compared to without PCM shows the cooling effect of adding PCM under both natural and forced ventilation modes of heat removal. It found that inclusion of each of the three types of PCM into heat sinks with natural convection shows higher temperature drop (up-to 15 °C) in first 15 min of heating than inclusion of fan (forced convection) without PCM. However, the combination of both the fan ventilation and the PCM always maintain the lower temperature other three modes. This leads to conclusion that implementing a PCM in the heat sink will be very useful in thermal management of the electronic device and the application is more suitable under cyclic thermal loading conditions since in all cases the PCM completes melting in certain time and then shows a temperature rise. It is recommended to use forced convection combined with PCM filled in HS to increase the cooling effect while using PCM will be recommended for short time operation or cyclic operation such as switching operations where PCM can be regenerated to solid during off duty cycle to be ready for the next cycle of heat absorption. It is also recommended to use PCM integrated into a HS to provide a backup passive cooling support especially in case of failure of the fan system during operation as an additional safety cover. For the numerical part of the study, a three dimensional transient heat transfer numerical model using commercial ANSYSCFD software is developed and is validated against the experimental results. Next the numerical model is used to optimize the heat sink geometry, the PCM amount and the cooling-heating response in order to identify potential applications in electronic packaging in terms of temperature drop and charging-discharging cycle time. From parametric study, it is observed that a narrow melting point, not mixing of the PCM, good thermal conductivity, higher density, rectangular fin type and a reasonable package size are optimum for the temperature control of electronic devices employing heat sink with PCM.

DJOUAD Meriem, GHAMRI Khadidja

كلية الاداب واللغات-جامعة محمد خيضر - بسكرة · الجزائر

Résumé La littérature maghrébine francophone est un espace interculturel. Comme nous avons vu chez Ben Jelloun, l'interculturel est un mode dont les conséquences de la rencontre de l'autre ne sont pas généralement positive, elles peuvent être négatives sous forme d'autres phénomènes comme l'acculturation et l'assimilation. Donc, la mauvaise compréhension de l'interculturel empêchera son fonctionnement.

Madhat Shkir Madhat Al Soud

الجامعة التكنولوجية · العراق

ابراهيم سعيد محمد, مودة عوض سليمان علي الشاعر

كلية الدراسات العليا-جامعة السودان للعلوم والتكنولوجيا · السودان

Fusarium oxysporium affects a wide variety host of different age Tomato, Tobacco, Legumes, Cucurbits. Sweet Potatoes, Chickpea and Banana. The present investigation was undertaken under laboratory of Plant protection Department, College of Agricultural Studies, Sudan University of Science and Technology during November 2015 to February 2016, to study the effect of Damas plant parts (leaves, fruits, barks and roots) aqueous extracts and fungicide Score (250 EC) on growth of the fungus Fusarium oxysporum causal agent of wilt disease in crops. Three concentrations of aqueous leaves, fruits, barks and roots extract of Damas, each of 25, 50 and 100%, and fungicide were used in addition to control. The assessment of their inhibitory effect against the pathogen was recorded through the fungal growth. The results showed that all concentration of the leaves fruits, barks and roots aqueous extracts Damas plant tested and fungicide of significantly inhibitory effect against the linear growth of Fusarium oxysporium compared to control. Moreover, concentration of each aqueous extract reacted differently against Fusarium oxysporium. However, the highest concentration of the Damas extracts (100%) gave significantly higher inhibition zones percent respectively (75.5%, 68%, 66%, and 50%) compared to the untreated control. Among the Damas parts extracts screened the fruit (75.5) was the most effective in suppressing the fungus growth than its equivalent other part. the results showed that the antifungal activity increase with increase in extract concentration. Obviously, the fungus Fusarium oxysporium differs in its response to the different concentrations but on the whole, growth inhibition increased with the concentration. The current results were considered promising and encouraging to carry out a photochemical analysis of different parts of Damas plant using different solvents so to determine the bioactive ingredient in each of these parts.