In this work, the estimation capacity of the response surface methodology (RSM), in the catalytic naphtha reforming to enhance the octane number of reformats via isomerization reaction pathway and minimize the aromatization activity over tri-metallic modified Pt-Re/Al2O3 catalyst were investigated by applying Design of experiment (DOE). The parent bimetallic catalysts were modified using a relatively inactive metal (Sn) by means of employing non-conventional method of anchoring technique called controlled surface reaction (CSR) method in order to favor the intimate contact of Sn with the active phase to suppress the metallic character of Pt metal. The correlations between RON, aromatization and isomerization activities with three reaction variables namely temperature (480-510oC), pressure (10-30 bar) and space velocity LHSV (1.2-1.8 h-1) were presented as empirical mathematical models via reforming of a complex mixture (80oC -185oC). Numerical results indicated that the minimum aromatization activity was 20% when reaction temperature was 460oC and pressure of 35 bar. Results also show that maximum isomerization activity of 58% was achieved when pressure is 30 bar and space velocity is 1.8 h. it has been found that optimum value of RON = 89 was attained at 449.9oC, 32 bar and 1.7 h-1. However, high operating pressure and low reaction temperature significantly decrease the aromatization activity coupled with substantial decrease in RON which can be enhanced by producing high yield of isomers.  

Using information and communication technology to engage Libyan University students in the English Culture, Rewaq Almarefe –scientific journal, third and fourth issues 2015

This paper presents the findings of the investigation of ERP implementation. It highlights the challenges and experiences of Libyan Companies in ERP implementation. The success factors, failures are analyzed and have proposed recommendations to improve ERP implementation. The adopted research approach covers both quantitative and qualitative methods. The data collection methods used were questionnaires, 75 out of 100 questionnaires were returned sufficiently completed. The paper contributes to discussion based on literature review and ERP implementation in developing economics. The results of the study revealed that the majority of the respondents are aware of what ERP is all about, and they are also aware about critical issues in the implementation of ERP. The findings revealed that: failure to select committees needed for the successful implementation of ERP, an inadequate financial budget and resources, and failure to make knowledgeable input at the planning stage can be problems to successful implementation of ERP. The conclusions suggest for addressing challenges and problems in the ERP implementation. Enough time should be provided to project team, show leadership in change management and sufficient resources should be allocated for the proper implementation of ERP.

It has become firmly established the productivity is the real source of and important for economic growth of any country; it has an essential role in the economies of developed and developing countries alike. It allows the nation to raise its standard of living, to support such social goals as education and health care, and to contribute to other aspects of the general welfare; it is an essential underpinning of the nation's security (Stupak and Leitner, 2001). Increased productivity is the key to economic progress, where the standard of living of communities and income levels depend on the progress of the level of productivity; higher levels of productivity in economies lead to increased rates of growth and prosperity (Seid, 1996).

Abstract: Monitoring the concentrations of heavy metals in natural and waste water at and below the level of their maximum permissible concentrations is an urgent environmental problem. Hence, new procedures for the preconcentration of heavy metals with their subsequent determination by different methods are required. Along with other sorbents, significant attention is attracted to polymer chelating sorbents, which provide individual or group extraction of trace elements, eliminate matrix effects, and provide high concentration factors. The effect of the various parameters such as electrochemically and chemically synthesis methods, physical oxidation state of the polymer, polymer thickness, solution pH and metal ion concentration on the adsorption, kinetics and efficiency were investigated. The results showed a vary broad concentration range of the heavy metals from (0.05 to 10 mg/L) can be adsorbed on different kinds of polymers at different pH values and different efficiently. The adsorption capacity of the polymer to different concentrations of heavy metals was evaluated as the milligram of metal ions by one gram of various forms of the polymer. The DC conductivity measurements were also employed on the solid polymer before and after adsorption of metal ions. The experimental adsorption date was fitted to different mathematical isotherms to estimate the binding constant of heavy metals with the polymer in both single and mixed ion solutions. The method provides the extraction of analytes from natural water of complex composition containing high concentrations of alkali, alkaline-earth and other elements and is characterized by rapidly, selectivity, low detection limits, and a high reproducibility of the results. The relative standard deviation is 2-4%. The technique was test with real waste water samples.  

The effect of a relatively inactive metal on the texture properties and catalytic performance of bi-metallic platinum–rhenium (Pt–Re)–S/Al2O3–Cl catalyst was investigated. The concentration of introduced tin (Sn) varied between 0.06 and 0.32 % (weight basis). The parent and modified catalysts were characterized using the following techniques; BET, X-ray diffraction, SEM–EDX, and atomic absorption spectroscopy/inductively coupled plasma spectroscopy. The bi-metallic and tri-metallic catalysts were also screened for their activity and selectivity in the reforming of n-octane under the following conditions: T = 480 °C, p = 10 bar, WHSV = 3.3 h⁻¹ and H2:HC = 4.5. Results showed that, on n-octane conversion, selectivity have changed favorably i.e., low selectivity to aromatics but high selectivity to iso-paraffins and olefins. In addition, less cracking products were detected and high liquid yields (LYs) were obtained. However, there is a strong and closely linear correlation between aromatics and octane number. The results of this work showed that catalyst with Sn >0.14 and <0.32 performed the best catalyst i.e., no major effect on research octane number, LY and selectivity with the addition of more Sn.

( حول جدلية العلاقة بين زمن اللفظ وزمن التلفظ )

يُعرّف عالم اللغة الشهير فرديناند دي سوسير اللغة بأنها متوالية من الدلائل اللغوية التي وضعها الهيكل الاجتماعي ليسمح باختيار أو استخدام ملكة الكلام لدى الأفراد ، ولها معاييرها المحددة ، ولهذه المتوالية الصوتية المرسلة بدايتها ونهايتها تتحدد بفترة الصمت المؤقت بين متوالية صغيرة منها مجموعة الجمل والكلمات . أما التلفظ أو التكلم أو الأداء فهو الطريقة الفردية الخاصة لاستعمال اللغة ، في حين أن الحديث هو نتيجة هذه العملية ، وعملية التلفظ هذه تحركها هي الأخرى مجموعة من العوامل تكون سببا في النهاية لوجود الحديث الذي يمكن أن يكون نحويا أو دلاليا ، فمجموعة الأحاديث تشكل عينة لغوية قائمة على مجموعة من الجمل المبنية على قواعد ، وفي اللسانيات يطلق المصطلح على جزء من المنظومة الكلامية طولها يتحدد بعلامات الترقيم كالفاصلة والنقطة ... الخ . ولقد تناولت الدراسات اللغوية العلاقة الجدلية بين اللفظ والتلفظ والتي أخذت مسميات ومستويات شتى في التحليل نظرا لتناولها من زوايا مختلفة ورؤى متباينة نظرا لتشعب الموضوع وارتباطه مباشرة بالمحيط اللغوي والاجتماعي المتغير بطبيعته ، وهو ما حدا بكل تلك الدراسات الى اعتبار العلاقة جدلية ضمن الفضاء العام للتواصل بين اللفظ والتلفظ وبين الجملة والملفوظ وتعلق فعل الملفوظ بفعل التلفظ وهكذا .  

Introduction

L'énoncé est l'objet produit, réalisé et engendré par le processus d'énonciation . Un morphème, un syntagme, une proposition, une phrase, un ensemble de phrases et un texte achevé peuvent constituer un énoncé. L'énonciation est - telle que E. Benveniste l'a défini " cette mise en fonctionnement de la langue par un acte individuel d'utilisation". Il va jusqu'à dire que " l'acte même de produire un énoncé "( E. Benveniste,1970: 12),). L'acte d'énonciation est le fait du locuteur qui mobilise la langue pour son compte. Aussi pour Anscombre et Ducrot(1970:12) : "L'énonciation sera l'activité langagière exercée par celui qui parle au moment où il parle". L'énonciation est donc par essence historique, événementielle, et , comme telle, ne se reproduit jamais deux fois identique à elle-même.C.K ORECCHIONI propose au terme « énonciation » deux glissements sémantiques. Le premier consiste à dégager le produit de l’acte de production. L’énonciation sera donc dans ce cas, l’acte de production d’un énoncé. Elle a dit à ce propos « À l’origine l’énonciation s’oppose à l’énoncé comme un acte à son produit, un processus dynamique à son résultat statique »(Ibid.1999:33). Elle propose dans le second glissement une idée qui est l’énonciation est l’action centrée sur celui qui exerce l’acte, sans négliger l’aspect communicationnel qui est fortement présent et qui s’établie entre deux partenaires, dans la mesure où le locuteur implique l’autre, alors qu’il n’est pas vraiment l’élément principal sur lequel l’énonciation fonde ses principes.

L'énonciation suppose selon E. Benveniste la conversion  individuelle de la langue en discours. Toute communication se passe dans un espace - temps déterminé, qui peut être contraignant, en ce sens qu'il exerce une influence déterminante sur le langage utilisé, ou non contraignant si le choix des moyens linguistiques n'est pas conditionné par les conditions spatio-temporelles du message.