اهاب عبدالله عبدالمحسن سكافي, مهند فؤاد استيتي

كلية الدراسات العليا-جامعة الخليل · فلسطين

نصٌيرة بشارف, ابتسام مرابط, توبين علي

كلية العلوم الاقتصادية والتجارية وعلوم التسيير-جامعة الجيلالي بونعامة - خميس مليانة · الجزائر

Fairouz Zouaoui, فريد رباح

كلية التكنولوجيا-جامعة فرحات عباس - سطيف1 · الجزائر

Cette thèse porte sur l'étude de l’effet du traitement thermique sur les propriétés thermophysique d’un MCPSà base d’un polymère amorphe et un polymère semi-cristallin. Tout d'abord, nous avons fait une étude sur deux polymères amorphes le PC et le PMMA en présence et en absence de C.R.,pour montrer l’effet de la structure d’un polymère sur les propriétés thermophysique. Ensuite, une comparaison s’est faite entre le PC et le PEHD et leurs composites pour savoir l’effet de l’ajout de Cu et/ou le MCP. L'étude par ATG a montréque la paraffine diminue la stabilité thermique des polymères maisle Cu améliore la stabilité thermique d’un MCPS. D'autre part, l'analyse par DSC a montré que la paraffine joue un rôle de plastifiant. Les résultats DMA ont montré que le recuit provoque l’apparition d’un picß1à environ 35 °C vue l’absence des C.R. L’étude par DICO et disque chaudrévèlent que Cu peut améliorer efficacement la conductivité thermiquedu MCPS et présentent des valeurs différentes mais l’évolution en fonction du traitement thermique présente des tendances similaires.

أحمد محمود حسين صابون, كوثر محمد سعيد محمد علي

كلية الشريعة والدراسات الإسلامية-جامعة أم القرى · السعودية

هاشم عبدالخالق كشكول, وفاء سمير محمد عبدالسيد

كلية التربية للعلوم الصرفة-جامعة البصرة · العراق

عادل عبسات, لبنى بهيج

كلية الطب والصيدلة-جامعة محمد الخامس بالرباط · المغرب

Elsadig Ahmed Jumaa Munhal, Gamar El-Booni

كلية الاداب-جامعة الخرطوم · السودان

The purpose of this research is to investigate and analyze the techniquesand strategies adopted by the secondary school teachers at the Blue NileState to develop their students' oral fluency in English language.The sample of the research consists of 40 teachers selectedrandomly. A questionnaire was used to collect the data. It consisted of 20questions.A descriptive approach of data analysis has been employed in thisresearch. The descriptive analysis concerned mainly with describingproblems related to the components of teaching/learning process: theteacher, students, and teaching materials. The data has been provided informs of frequency, tables and percentages.The results of this research have almost confirmed the following:1. The training opportunities provided by schools for staffdevelopment are too little to enhance the teachers’ capabilities ofthe teaching/learning process.2. The teachers have little practical experience of teaching/learningtechniques inside the classroom which hinders oral fluencydevelopment.3. The teaching material is not well designed to develop oral fluency

Hiba Sheheitli, Richard Herbert Rand

مدرسة الدراسات العليا-جامعة كورنيل · الولايات المتحدة

The method of direct partition of motion (DPM) has been widely used to study the dynamics of non-autonomous oscillatory systems subject to external high frequency excitation. In this work, we explore the non-trivial dynamics that arise in autonomous systems with vastly different frequencies, in which the fast excitation is intrinsic to the system and possibly influenced by the slow dynamics. Using three model problems, we illustrate how DPM could be useful for the analysis of such systems and when combined with WKB can serve to capture the strong modulation of a fast oscillator due to coupling to a much slower one -a phenomenon that is not readily handled using standard perturbation methods. First, we study a system of three coupled limit cycle oscillators, which when uncoupled, have the frequencies [omega]1 = O (1), [omega]2 = O(1/[epsilon]) and [omega]3 = O(1/[epsilon]2), respectively, where [epsilon] << 1. Approximate expressions for the limit cycles of oscillators 1 and 2 are found in terms of Jacobi elliptic functions. For coupling strengths exceeding critical bifurcation values, the limit cycle of oscillator 1 or 2 is found to disappear. In the second problem, we consider a simple pendulum coupled to a horizontal mass-spring system of a much higher frequency. In contrast to the first problem, the coupling here allows the slow oscillator to affect the leading order dynamics of the fast oscillator. This calls for a rescaling of fast time, inspired by the WKB method, to be employed in conjunction with DPM. We obtain a critical energy value at which a pitchfork bifurcation of periodic orbits is found to occur, giving rise to non-local periodic and quasi-periodic orbits in which the pendulum oscillates about an angle between zero and [pi]/2 from the downwards position. Finally, the developed method is utilized to explain the non-trivial dynamics arising in a model of a thin elastica presented by Cusumano and Moon in 1995. We observe that for the corresponding experimental system, the ratio of the two natural frequencies of the system was [ALMOST EQUAL TO] 44 which can be considered to be of O (1/[epsilon]) where [epsilon] << 1. Hence, the system is best viewed as one with vastly different frequencies. The method leads to an approximate expression for the non-local modes of the type observed in the experiments as well as the bifurcation energy value at which these modes are born. The formal approximate solutions obtained for these problems are validated by comparison with numerical integration.

Babahadj Abdelhafid, Laouar Mohamed

كلية العلوم التكنولوجية وعلوم المادة‎-جامعة قاصدى مرباح ورقلة-جامعة قاصدى مرباح ورقلة · الجزائر

La mise en place d’un système de gestion des bases des données d’accident de travail est un étape pour l'évaluation et le contrôle des risques et la mise en œuvre de la politique de santé et de sécurité de travail, avec le grand développement considérable dans les techniques utilisées, et avec le nombre croissant d'accidents et de maladies professionnelles, il incombait à la création d’un bases des données découlant d'une manière par laquelle utiliser l'information par une meilleure et plus simple forme, ainsi que les données sont nécessaires, en particulier dans nos jours, ainsi que leur analyse donner des résultats plus rapide pour les propriétaires d'entreprise, où ils peuvent par cette analyse à prendre les décisions appropriées pour eux dans leur travail. Ce système dépend principalement sur des statistiques complètes et précises sur les accidents du travail et les diverses maladies professionnelles qui est survenir dans l’entreprise qui ont but pour évaluation les risques individuelle et collective, ce qui permet à prendre les mesures et les précautions nécessaires qui correspondent et répondent de manière adéquate à ces estimations.يعتبر إنشاء نظام تسيير قاعدة معطيات حوادث العمل خطوة من أجل التقييم والتحكم الجيد في المخاطر وتطبيق سياسة الصحة والسلامة في العمل ,فمع التطوّر الكبير والهائل في التقنيات المستعملة، ومع زيادة حصيلة الحوادث والأمراض المهنية ، كان لزاماً على المؤسسة أن تنشا قاعدة للبيانات بطريقة يُمكن من خلالها توظيف المعلومات بأفضل وأسهل شكل؛ فالبيانات ضروريّة خاصّةً في يومنا هذا؛ إذ إنّ مُعالجتها تؤدّي إلى إعطاء النّتائج وبالسّرعة القُصوى لأصحاب الأعمال، حيث يُمكنهم من خلال هذه البيانات المُعالَجة اتّخاذ القرارات المُناسبة لهم في وظائفهم المُختلفة.يعتمد هذا النظام أساسا على إحصائية شاملة ودقيقة حول حوادث وإصابات العمل والأمراض المهنية المختلفة التي تحدث للمؤسسة الصناعية.وذلك بغية تقدير المخاطر الفردية والجمعية , مما يسمح باتخاذ الاحتياطات والتدابير اللازمة التي تتلاءم وتستجيب بشكل كاف لهذه التقديرات.

Abd el Aziz Abd el Rahim Mohammed Ahmed, Gabriel Atillio Machar

كلية العلوم-جامعة الخرطوم · السودان

The present investigation was designed and conducted in Nuba Mountains from Period of 2002-2003, where three villages were selected as study area: Habilla, Dilling and Fayo. The main objective of the investigation was to provide the main baseline information on the crucial epidemiological aspects of Bilhariza. All children were included in the study together with the a randomly selected 50% of the villagers from each of the three residential areas. The obtained results reassured that the situation of urinary schistosomiasis was miserable, where the overall prevalence of infection was 43.2% among the villagers and 30.8% among the school children. Exactly half of the investigated villagers have the history of infection, where (18.6%) of them were still suffering the infection. It appears that the three villages have the same rate of the infection: Fayo (47.6%), Habilla (43.8%) and Dilling (36.5%). The finding highlighted that Dilling has a considerable proportionate of worm burden, expressed in excreted eggs (107.2 eggs/10ml of urine). The infection parameters of urinary schistosomiasis varied with age-classes, where the infection significantly peaked at the age-class of (10-20) years among the population, and the age-class (> 15) years among the school children. Concerning the interspecific variations of infection parameters, the analysis suggested significant differences in worm burden in the three villages, on gender basis. Although the proportion of infection varied among the males of the three villages, no appreciable variation was detected among the females, where the prevalence skewed to the lowest rates. The study also suggested that transmission seasonality of S. haematobium occurs mainly during the rainy season, from June-February. The investigation monitored the key factors in the extensive transmission and distribution of urinary schistosomiasis in the study area were proximity to waterbodies, combined with absence of latrines and poor personal and communal hygiene as well as the lack of clean water-supply. Furthermore, some of the addressed socioeconomical parameters were judged to be influential in the transmission pressure of urinary schistosomiasis. These include: the households’ educational level, occupation category, accessibility to latrine and water-supply systems. The adopted intervention reduced the prevalence rate of Bilharzia among the school children by 22.7%, while the reduction of intensity of infection postured 30.4 eggs/10ml of urine. The post-intervention findings stressed that the reduction of the prevalence rates among the infected school-children was not significant. As expressed, the observations of the villagers’ water-contact activities in/around Pools and Hafiers recapitulated that: the villagers who used to expose themselves to contaminated waterbodies were the most suffering (33.3%) and (58.8 eggs/10ml of urine). Although two-thirds of the water-contacts were predominated by the females, still the males significantly suffered both prevalence and worm burden. The findings suggested synchronized patterns of the villagers’ age-classes, to the frequencies of water-contact and the amplitudes of the two infection parameters. However, the gradual increase reaches an apex at the age class (10-20) years. In addition, the analysis of the findings stressed that the frequency of water-contacts, varied based on age-classes of the villagers. The malacological surveys, for 12 months, assured that Bulinus truncatus snails are the most abundant intermediate-host of S. haematobium in the Nuba Mountains. The number of snails collected during the study, varied in distribution, according to some important regulating factors. It appears that the interval August-November not only represented the apex of snails’ population (76.5%), but also the high snails’ infection (100%). On the other side, the field investigation on the aestivated snails highlighted that 27.3% of them were infected with non-human cercariae, while not a single aestivated snail was found liberating human-cercariae. The designed laboratory experiments stressed that the apex of the cercarial liberation from both naturally and laboratory infected snails was at 11-01 pm. Unfortunately, such interval of cercarial emission was found in symphony with the villagers ware-contact activities, thus, representing the most risky time for them to acquire infection. Lastly, based on the findings of the investigation and the stress of the fact that Bilharzia has hazardous effects on its victims, arrays of accessible recommendations were generated for adoption