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Biodegradation of aromatic hydrocarbons by an extremely halophilicarchaeNatrialbasp. C21 isolated fromoilcontaminated saline water in Ain Salah, Algeria
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Effects of gibberellic acid on ovarian biochemical composition and ecdysteroid amounts in the migratory locust Locusta migratoria (orthoptera, acrididae)
No full textEffect of hydrogen adsorption on the electronic and optical properties of the Mg-doped O-terminated ZnO surface
No full textNumerical simulation of methane-air equivalence ratio effect on premixed low swirl stabilized flame
No full textIs algeria ready to integrate the knowledge-based economy?
No full textThis paper focuses on the problem of Algerian economy mutation, from an economy based on oil as the sole source of income, to a knowledge economy based on competence of human resources and knowledge to achieve economic growth. This paper try to find answers to the following questions: what is the position of Algeria against the indicators of the Knowledge economy compared to the rest of the world? What mechanisms and policies that should be put in place to integrate Algeria in this new economy? Based on a comparative analysis we examine the readiness of the Algerian economy to Integrate Knowledge economy. The study adopts The World Bank methodology based on the four pillars– institutional regime, education, innovations and ICT. It summarizes both positive and negative sides, difficulties, and relies on the possible actions to resolve them regarding the attainment of the relevant national objectives. The study revealed that Algeria should pursue a long-term strategy for the development of knowledge, focusing on achieving a real rate of growt
إنعكاسات سعر العملة على الميزان التجاري ومؤشر أسعار الاستهلاك : حالة الجزائر (1980-2013)
No full text157 ص. : ايض. ; 30 سمتهدف هذه الدراسة إلى محاولة معرفة مدى تأثير التغير في سعر العملة على الميزان التجاري ومؤشر أسعار الإستهلاك في الجزائر خلال الفترة (1980-2013)، وبعد دراسة إستقرارية السلاسل الزمنية (LIPC, LBC, LTCH) ووجود علاقة التكامل المشترك بين المتغيرات، إستخدم نموذج شعاع تصحيح الخطأ (VECM) لدراسة علاقة طويلة الأجل بين متغيرات الدراسة. إنّ معادلة رصيد الميزان التجاري غير معنوية وتوجد علاقة عكسية بين سعر العملة والرصيد، إذ أن سياسة تخفيض قيمة العملة في الجزائر لا تساهم في تنمية الصادرات وذلك لأنه بلد ريعي، بل تؤثر سلباً على رصيد الميزان التجاري بارتفاع تكلفة الواردات. أمّا معادلة مؤشر أسعار الإستهلاك فهي معنوية تكتسي طابع الإÀجابÀة مع سعر العملة، أي أنّ إرتفاع سعر العملة من جراء التخفيض يؤدي إلى الإرتفاع في المستوى العام للأسعار، وذلك لطبيعة الاقتصاد الجزائري الذي يعتمد على الواردات لتحقيق الإكتفاء الذاتي للبلاد أمام العجز الكبير للإنتاج الوطني. كما كشفت الدراسة القياسية عن وجود علاقة سببية أحادية الإتجاه من سعر الصرف إلى الميزان التجاري ومؤشر أسعار الاستهلا
Investigation of the Biodegradability of LDPE/PLA Bioblends: Comparison of Hydrolysis and Soil Burial Tests
No full textThe present work concerns the preparation and characterization of new biodegradable materials by mixing poly lactic acid (PLA), a biodegradable polymer, with low density polyethylene (LDPE), a current thermoplastic that can be bio-based. For that purpose, LDPE/PLA blends of variable composition (100/0, 80/20, 50/50, 20/80, 0/100) were prepared. They were characterized in terms of physical properties (density, melt flow index), thermal properties (melting temperatures) and mechanical properties (tensile and Shore D hardness). Their morphology was investigated by scanning electron microscopy. Hydrolysis and soil burial tests were conducted to study the biodegradation behavior. The weight loss of the samples with time was followed. The structural changes were investigated by FTIR spectroscopy and microscopic observation. Mechanical analysis showed that the strength at break increased with the level of PLA while the elongation at break decreased strongly due to the non miscibility of the two polymers. The SEM micrograph of blends 20/80, and 80/20 evidenced poor adhesion at the interface between the two polymers. The PLA confers a brittle character to its blends. The highest rates of mass variation were observed for the blend containing 50 and 80 wt% of PLA and were about 72 and 55 wt% after 45 days for the hydrolysis test and 10 and 2.5 wt% after 18 weeks of soil burial