Abstract: This review aimed to investigate the effect of pH on morphology, and size of gold nanoparticles (AuNPs) biosynthesized using extracts of various plant parts and agricultural waste. By reviewing previous studies, it was found that the formation of AuNPs was more rapid in neutral and basic mediums than in acidic mediums. Furthermore, most of those studies indicated that the smallest sizes of biosynthesized AuNPs, produced by plant extracts, were in neutral and alkaline mediums. Regarding the morphology, it was found that multiple shapes of the AuNPs were obtained in an acidic medium of the reaction, while there was typically a dominant shape of the AuNPs in the basic medium. In conclusion, significant quantities of AuNPs with appropriate sizes and morphology could be obtained by controlling the medium of the reaction when AuNPs are biosynthesized using extracts of plant parts and agricultural waste.

The problem of microbial resistance continues to increase in all regions of the world, and even though a very large number of antibiotics have been produced in the last 30 years, microbial resistance is maintained because of the wide use of these drugs against many infectious diseases. Thus, natural products are seen as the alternative solution. Based on previous studies, Peganum harmala has been reported to exhibit several biological properties including antibacterial and antifungal. Thus, the main aim of this study is evaluating antibacterial activities of P. harmala against Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus, which isolated from infected patients in (Alassaba'a hospital, Alassaba'a, west of Tripoli). Agar disk diffusion technique was used for detecting the antibacterial activity, and the minimum inhibitory concentration was tested by serial dilution methods. The results showed that the growth of all tested bacteria were inhibited strongly by methanol extract of seeds at 1.0% with inhibition zones 14.66, 12.00 and 15.33mm against E. coli, k. pneumoniae and S. aureus respectively. Besides, MIC values ranged between 0.625 to 1.25 mg/mL. While, MBC values ranging between 1.25 to 5 mg/mL. On the other hand, methanol extract of leaves was also inhibit the growth of E. coli, k. pneumoniae and S. aureus with inhibition zones 11.00, 9.66 and 10.00mm respectively. As well as, MIC values ranging between 1.25 to 2.5 mg/mL, while MBCs value ranging between 2.5 to 5 mg/mL . In conclusion, methanol extract of P. harmala seeds exhibited strongly antimicrobial activity against E. coli, k. pneumoniae and S. aureus, thus it can be developed as anti-bacterial agent.

Biosynthesis techniques have a number of advantages over other methods for producing silver nanoparticles (AgNPs), which provide a wide range of applications. The present work highlights the biosynthesis of AgNPs by mixing pear leaf aqueous extract with silver nitrate, and the formation of AgNPs was observed by the change of mixture color from yellow to dark brown and visible spectrophotometry. Moreover, the effect of pH, reaction time, AgNO3 concentration, extract volume and temperature on the suggested approach was also studied. The results showed that pear leaf aqueous extract is an excellent material for the biosynthesis of AgNPs, and by controlling the mentioned parameters that influence synthesis, a large number of AgNPs with small sizes may be produced.

Biosynthesis techniques have a number of advantages over other methods for producing silver nanoparticles (AgNPs), which provide a wide range of applications. The present work highlights the biosynthesis of AgNPs by mixing pear leaf aqueous extract with silver nitrate, and the formation of AgNPs was observed by the change of mixture color from yellow to dark brown and visible spectrophotometry. Moreover, the effect of pH, reaction time, AgNO3 concentration, extract volume and temperature on the suggested approach was also studied. The results showed that pear leaf aqueous extract is an excellent material for the biosynthesis of AgNPs, and by controlling the mentioned parameters that influence synthesis, a large number of AgNPs with small sizes may be produced. Keywords: silver nitrate, silver nanoparticles, pear leaves, biosynthesis 

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نظام إشارات المرور هو أداة تنظم المركبات ذات العجلات من أجل العمل بانتظام. نظام إشارات المرور العادية الحالي ليس كافيًا للتحكم في الازدحام المروري بسبب أنه يعمل وفقًا لخطة زمنية محددة الوقت. ومع ذلك، فقد أصبح الازدحام المروري يمثل مشكلة كبيرة لمعظم البشر نظرًا لأنه يزيد من الضوضاء وتلوث الهواء وضياع الوقت .ومن ثم، فإن نظام إشارات المرور العادية لم يعد لديه القدرة على التعامل مع الازدحام الهائل، ويجب إيجاد حلول حول كيفية تنظيم المسار الذي يجب أن يسير أو يتوقف من أجل القضاء على ازدحام التقاطع بين المركبات.لذلك، تم تصميم نظام إشارات المرور الذكي المعتمد على تقنيات التعلم الآلي واكتشاف عدد المركبات تلقائيًا في كل حارة وضبط وقت الإشارة الخضراء على النحو الأمثل لتجنب وقت الانتظار الهائل والازدحام الواضح أيضًا بمعدل أسرع.أخيرًا، تم استخدام فيجول استديو و البايثون للمحاكاة, و خوارزمية (Branch and Bound) لتحديد أي منها يجب تشغيل الإشارة أو إيقاف تشغيلها، لأنه يتميز بخاصية إيجاد حل بين مجموعة من الحلول، ويتم تطبيق خوارزمية (greedy) لتحديد وقت الانتظار لكل مسار.

This study reports a rapid and eco-friendly green method for the synthesis of silver nanoparticles from silver nitrate solution using winter jasmine leaves extract as a reducing agent of Ag+ to Ag0. A visible Absorption Spectrophotometer was used to monitor the formation of silver nanoparticles (AgNPs). The visible spectrum showed an absorption peak at 420 nm which reflects the surface plasmon resonance (SPR) of AgNPs. In addition to that, the synthesis of AgNPs was confirmed by the color change of the solution. By studying the most important factors affecting the formation of AgNPs, it was noted that the productivity of AgNPs in the solution increased by increasing the pH of the solution, and the basic medium was the appropriate medium for the synthesis process. Also, the amount of produced AgNPs increased with the increase in temperature, volume of extract, reaction time, the extract volume ratio of the winter jasmine leaves, and silver nitrate concentration. In conclusion, the aqueous extract of winter jasmine leaves represents a suitable material for the biosynthesis of AgNPs, and large amounts of AgNPs with appropriate sizes may be obtained by controlling the parameters that affect the synthesis process.

Engineering education has a crucial role in the economic and social development of society; this paper aims to investigate the most significant factors that contributing in improving the quality of the engineering education. Furthermore, identify the factors affecting the students’ academic performance. The study was conducted by using statistical Design of Experiments (DOE) approach to investigate the main effects of lecture delivery, assessment, engagement, communication, and interaction with instructors. Minitab software is implemented to perform statistical analysis to identify the significance of each factor, and degree by which each factor influences the students’ academic achievement. Results showed that the students’ academic performance is affected by the availability of course materials, and communications with instructors.