baghli hichem, ENABBOU Oussama, KABECH Ali, KACEMI Ali
كلية العلوم الطبيعية والحياة، علوم الأرض والكون-جامعة أبو بكر بلقايد - تلمسان · الجزائر
Abdulaziz A. Al-Saadi, كبيرو هارونا
كلية العلوم-جامعة الملك فهد للبترول والمعادن · السعودية
Halogenated anilines are widely used as chemical intermediates in the manufacture of dyes, drugs, and other chemical compounds. A comprehensive comparative computational study on the structural and spectroscopic properties of the complete set of halo-substituted anilines (from mono- to penta-substituted ones with halogens being F, Cl and Br) was carried out. The structural stability of the compounds were investigated by the DFT-B3LYP and the MP2 methods with the 6-311++G(d,p) basis set. The compounds were all predicted by both the DFT and MP2 methods to exist predominantly in the pyramidal near-planar structure. The position and number of the halogen substituents were predicted at the DFT level of theory to have the most significant effect on the NH2 inversion barrier. The vibrational IR and Raman spectra for the compounds were calculated at the DFT level of theory. Optimized geometrical parameters and calculated vibrational frequencies were compared for the titled compounds. A detailed vibrational assignment of normal modes for 2,4,6-trihaloanilines were made on the basis of calculated potential energy distributions (PEDs), observed and calculated IR and Raman spectra. The calculated spectra show very good agreement with experiment. Surface enhanced Raman scattering (SERS) detection of 2,4,6-trichloroaniline (246-TCA), 2,4,6-tribromoaniline (246-TBA), naphthalene and phenanthrene using aged hydroxylamine reduced silver colloid was also carried. SERS spectra in ethanol solution of both 246-TCA and 246-TBA were obtained up to a concentration of 10-6 M. And SERS detection of as low as 10-12 M and 10-10 M were obtained for the aqueous solution of naphthalene and phenanthrene respectively.
Lise Emile Safatly, علي الحاج
كلية مارون سمعان للهندسة والعمارة-الجامعة الأمريكية في بيروت · لبنان
The need for an efficient spectrum usage policy is becoming more pressing due to the rapid growth of wireless communications applications and the under-utilization of most licensed bands. Cognitive Radio arises to be a novel solution to this spectrum wastage problem by allowing the dynamic allocation of unused bands. In these scenarios, a secondary or unlicensed user detects, exploits and utilizes an unoccupied spectrum band, called a white space, reserved for primary users. Thus, two major functions of a cognitive radio transceiver are scanning the spectrum for a potential white space and transmitting a suitable adaptive signal. In real-world dynamic scenarios, this highly adaptive radio technology presents unique signal processing challenges and requires specific algorithms for spectrum sensing and spectrum sculpting. In an Ultra-Wide Band (UWB) scenario, secondary users are required to scan bands that are of hundreds of megahertz in width. This puts strict hardware requirements on the RF front-end, relating to the linearity, dynamic range and sensitivity of the circuitry. On the other hand, RF impairments could dramatically degrade the performance of the secondary user. These imperfections result from the large spectrum to be sensed and from the low-cost implementations of the analog RF front-ends. In such scenarios, advanced signal processing algorithms are required not only to sense the incumbent spectrum but also to improve the radio sensitivity by mitigating the RF impairments effects to relax the hardware requirements. In this dissertation, we investigate and propose signal processing algorithms to build a highly adaptive, fully functional cognitive radio transceiver working in the UWB range. At first, we start by studying basic spectrum sensing algorithms, we then move to assess the performance of these algorithms against RF impairments. A blind algorithm is selected, improved and implemented in real-world scenarios. A mitigation stage is devised and added to the sensing scheme in order to obtain a r
Lyza Tafat, F. Cherifi
كلية هندسة معمارية-جامعة مولود معمري - تيزي وزو · الجزائر
أمينة روميسة حدادي, سعيد بومعزة, مايسة لعرافة
كلية الآداب واللغات-جامعة 8 ماي 1945 قالمة · الجزائر
تناولت الرواية الجزائرية العديد من الموضوعات المرتبطة بالواقع المعيشي، من بينها موضوع الهويّة الوطنيّة، ومحاولة فرنسا طمسها، وترسيخ مبادئ ثقافتها عند الجزائريين، وقد حاول الشعب الجزائري الصمود والوقوف ضدّ أيّ تدخّل يهدّد هوّيته، وتعدّ رواية أنا وحاييم من النماذج الروائيّة التي انفتحت على العديد من الأنساق المعرفية المستقاة من التاريخ، والمجتمع، والثقافة، والدين، فقد سعت دراستنا الموسومة بخصائص خطاب الهوّية في رواية أنا وحاييم للحبيب السائح، إلى مقاربة موقف الروائي من خلال طروحاته الداعية إلى التأكيد على الهوّية الوطنية عبر رسالة مشفّرة أكّد فيها على ضرورة التعايش السلمي، والتحرّر من الانغلاق الديني.
الزهرة لحلح, إسماعيل زروخي
كلية أصول الدين-جامعة الأمير عبد القادر للعلوم الإسلامية · الجزائر
صافي عمال صالح, نور راجي محمد حسين الألوسي
كلية التربية للعلوم الانسانية-جامعة الأنبار · العراق
Abdul Rahim Abu-Husayn, Kamal Salibi
الجامعة الأمريكية في بيروت · لبنان
حسن عبيد غرباكم الطائي, يحيي مصلح علي المسقري
كلية الشريعة والدراسات الإسلامية-جامعة قطر · قطر
الحمد لله والصلاة والسلام على رسوله محمد وعلى آله وصحبه وسلم، وبعد:يتناول هذا البحث موضوع الوحي القرآني في منظور القراءة الحداثية، وقد توصَّل هذا البحث إلى أن أصحاب القراءة الحداثية مقلدين للغربيين من المستشرقين وغيرهم في كل ما تحدَّثوا به عن الوحي المبين، فرأوا أن الوحي ما هو إلا نتاج بشري جاء به المرسلون من عند أنفسهم، وقد هدفوا بذلك إلى نزع القدسية والغيبية والحكمية عن القرآن الكريم؛ ليتسنَّى لهم هدم كل ما كان عليه الأولون من العقائد والعبادات والتَّصورات، ولينقلوا ما جاء به الغرب في العصر الحديث في جميع المجالات والفنون ويصبغوا به حياة الناس في بلدان المسلمين.وقد اعتمدت في بحثي هذا المنهج الاستقرائي والتحليلي والنقدي
Hamad Thawab Al-Khaldi
كلية الهندسة-جامعة الملك فهد للبترول والمعادن · السعودية
The objective of this study is to determine the effects of drivers' attitudes on their accident involvement. The relationship among driver attitudes, their socio-economic backgrounds, and their accident involvement are investigated. The analyses conducted include factor analysis technique and Multiple regression analysis and its related statistics. Developed scales for driver attitudes show that they can affect their accident involvement. More emphasis should be directed towards scale development to achieve better results. Socio-economic backgrounds of drivers are also found to be associated with their accident involvement. Some of the attitudinal dimensions are affected significantly by their socio-economic backgrounds. The results of the study may be used in enhancing traffic safety in this region.
