النشر العلمي

  • دور المكتبيين في حفظ التراث المخطوط والمطبوع لمشروع الجزيرة:دراسة وثائقية ود مدني ، السودان

هدفت الدراسة للتعريف بمشروع الجزيرة،والكشف عن التراث الورقي المكتوب  بخط اليد والمطبوع و دور المكتبيين والوثائقيين في المحافظة على هذا الإرث الضخم من الأوراق والسجلات التي تعتبر جزء من التراث الوطني كما هدفت لتحديد حجم الوثائق الإدارية والفنية الخاصة والعامة ومعرفة نوعية الوثائق. وتقديم مقترح علمي مدروس لجمع وتنظيم وإتاحة هذا الإرث ليصبح قسم خاص من أقسام المكتبة المركزية بجامعة الجزيرة. أتبعت الدراسة المنهج الوثائقي و الوصفي والمنهج التحليلي. وتوصلت لنتائج منها أن الإرث المكتوب عن المشروع ضخم يستحق الاهتمام ، وضرورة وجود نظام حفظ آمن للتراث المكتوب و المطبوع وعدم الاهتمام بالمشروع أدى لفقد الكثير من التراث الورقي والمستندات الرسمية وغيرها من السجلات التي تعود لفترات الحكم الإنجليزي والحكم الثنائي ، ولم يكن هناك تدريب مستمر للعاملين في مجال السجلات في المشروع. يوجد تراث معاصر من السجلات والوثائق لم يصل لإدارة المشروع مثل وقائع المؤتمرات واللجان المنعقدة لتطوير المشروع، أوصت الدراسة ضرورة جمع كل الإرث المخطوط و المطبوع عن المشروع في مكان واحد. تبني جامعة الجزيرة عن طريق المكتبة المركزية الجديدة فكرة جمع التراث المكتوب والمطبوع والمسموع والمرئي ليصبح مكتبة فرعية متخصصة تخدم الباحثين في مجال المكتبات والمعلومات والتاريخ والآثار.

published in الجزيرة للعلوم التربوية والانسانية

  • Curing Process and Heat-Resistance of Polyethersulfone Toughened Epoxy Resins

In order to improve the toughness of epoxy resin, hydroxyl-terminated polyethersulfone (PES) with various amounts (0 wt.%, 5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%) were added to bisphenol A epoxy resin (DER331)/ curing agent DETDA (E100) systems, and the influence of PES contents on curing process and heat-resistance was studied. Non-isothermal DSC was used to determine the curing process of uncured DER331/E100/PES systems at heating rate of 2°C/min, 5°C/min, 7°C/min, 10°C/min and 15°C/min separately, and the apparent activation energy was calculated based on Kissinger method. The morphology of the etched cured DER331/E100/PES systems with different PES contents was observed by SEM. The heat-resistance of these systems was investigated by DSC and TGA. The results showed that with the increasing of PES content the curing exothermic peak, the heat of curing reaction, the initial and final curing temperature all decreased at the first and then increased, indicating that when the PES content was low (5 wt.%, 10 wt.%), PES can facilitate the curing process, while, when PES content up to 15 wt.%, PES can prevent or weaken the curing reaction. SEM results indicated that the phase structure changed drastically depending on the PES content. The systems with 5 wt.% and 10 wt.% PES were epoxy-rich phase, with 15 wt.% PES was co-continuity phase, and with 20 wt.% PES showed complete phase inversion (PES rich phase). The glass transition temperature and thermo gravimetric analysis demonstrated that the addition of PES can increase the heat resistance of cured DER331/E100/PES systems

published in Materials Science Forum

  • PLANT FIBERS REINFORCED POLY (LACTIC ACID) (PLA) AS A GREEN COMPOSITES: REVIEW

The interest in using natural fibers in composites has increased in recent years due to their
lightweight, non-abrasive, combustible, non-toxicity, low cost, and biodegradable properties. Natural fibers can
be used as reinforcement in polymers. The greatest challenge in working with natural fiber reinforced polymer
composites is their large variation in properties and characteristics. The composites, usually referred to as
‘‘green’’, can find several industrial applications. On the other hand, some problems exist, such as worse
processability and reduction of the ductility. The use of adhesion promoters, additives or chemical modification
of the filler can help in overcoming many of these limitations. The bio-composites made from poly(lactic acid)
PLA and plant fiber such as flax, kenaf, jute, hemp, ramie, bamboo, and sisal fibers will be reviewed. The
structure, composition, chemically treated mechanical properties; thermal characteristics of composites will be
discussed, as well as appropriate references for further in-depth studies.
 

published in International Journal of Engineering Science and Technology (IJEST)

  • Biodegradable poly (lactic acid)/poly (butylene succinate) fibers with high elongation for health care products

Poly (lactic acid)/poly (butylene succinate) (PLA/PBS) blend fibers with high miscibility and improved elongation with comparable mechanical strength were fabricated using the melt spinning process in order to reduce the impact on the environment by long-lasting plastics-based composites. The PLA/PBS blend fibers produced in different ratios have revealed high miscibility, which has been confirmed by morphological studies. The thermal properties showed the melting temperature of PLA at 167.13℃ and PLA/PBS blends at 169.18℃, and an increased content of PBS in blends also led to improved crystallinity. Importantly, during tensile testing, it is observed that the fracture behavior of the specimen changed from brittle fracture of neat PLA to ductile fracture of the blends, as demonstrated by the significant increase in the elongation at break with comparable tensile strength and modulus. Furthermore, the washing fastness, rubbing fastness, exhaustion values, strength loss, and shade depth (K/S value) for the knitted and dyed fibers were explored. It was found that the exhaustion and K/S value increased when the temperature increased, but the strength decreased. The exhaustion and K/S value of PLA/PBS blend fabrics improved compared to pure PLA fabric, with excellent washing and rubbing fastness.

published in Textile Research Journal

  • Dynamic Mechanical properties and Thermal stability of Poly (lactic acid) (PLA) and poly (butylene succinate) (PBS) blends composites

The blend of poly(lactic acid) (PLA) and poly(butylene succinate) (PBS) were prepared and extruded
with various compositions and their molded properties were examined. Thermogravimetric analysis
showed that thermal stability of the blends was higher than that of pure PLA and the weight loss of
PLA/PBS (40/60 wt%) was lower than neat polymers. Difierential scanning calorimetry thermograms
of blends indicated that the thermal properties of PLA did not change noticeably when blended with
PBS. The tensile strength and modulus of blends decreased with the increasing PBS content. But
impact strength has improved about two times compared to pure PLA. Rheological results revealed that
the addition of 10% and 20% of PBS increased the storage modulus, loss modulus and viscosity of the
blend at nearly all frequencies, and decreased viscosity with increasing shear stress. Dynamic mechanical
properties results showed the lowering of storage modulus of all blended PLA which indicated the increase
of molecular mobility by adding PBS due to lower glass transition
 

published in Journal of Fiber Bioengineering and Informatics

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