An understanding of consumption trends of smart phones on university campus: A comparison study

© 2018 Elsevier Ltd. All rights reserved. Smartphones continue to play an essential role in our daily life, providing people with many services that were not available before on standard mobile phones. The increased features and computing capabilities of Smartphones have allowed them to replace other portable machines, such as laptops, for many users, but particularly for university students. The main focus of the study is to compare the results of two studies conducted in 2014 and 2017 to understand the information consumption and usage patterns of the smartphone devices among Zayed University students. A survey on both studies was designed and administered to collect data from students on campus(2014: 415 participants, 2017:305 participants). The new findings show that smartphone penetration rate is still 100 percent (99%) among students, with almost half of the students (48%) own and use 2 of more smartphones. The new results reveal that What\u27sApp and Snapchat are taking over Instagram as the most popular social media application, socialization is taking over communication as the most popular activity on their Smartphones. There has been a major shift in the usage trend of smartphones from 2014. Nowadays, smartphones were commonly used for sociliazation, communication, enertainment, with few usage for educational and academic purposes. Further more, minor significant difference on usage concemption, activities and trend has been noticed based on gender. As expected with the way technologies is rapidly changing and emerging, a new smart phone brand “iPhone” has emerged to replace the previous one “Blackberry”. In addition, the most recent results(2017) show more students(51%) using their native language “Arabic” for communication

Experimental And Theoretical Stress Analysis For Composite Plate Under Combined Load

تم دراسة التأثير المشترك للحمل الحراري والميكانيكي على توزيع إجهاد-الإنفعال لصفيحة من الياف الزجاج والبوليستر المركبة بطريقتين التجريبيه والعدديه. العمل التجريبي تم من خلال تسليط درجة حرارة منظمة و حمل شد على الصفيحة مركبة داخل الفرن وقياس تشوه اللوحة باستخدام  dial gageمع دراسة تأثير أثنين من العوامل ، حجم الألياف وأتجاه الألياف على تحليل الاجهاد - الانفعال مع مماثلة الميكانيكية والحرارية التحميل. النتائج المعروضة هنا أن الحد الأقصى المطلق للإنفعال الكلي في الاتجاه الطولي حدث عند قوة شد 50 نيوتن وزاوية الألياف 60º، في حين أن القيم المطلقة الدنيا منه حدثت عند قوة شد 15 نيوتن وزاوية الألياف 0º. ومع ذلك، فإن الحد الأقصى المطلق للإنفعال الكلي في الاتجاه العرضي حدث عند قوة شد 15نيوتن وزاوية الألياف 0º، بينما تم الحصول على القيم المطلقة الدنيا عند قوة شد 50 نيوتن وزاوية الألياف 60º. وأيضا، فإن إنفعال الكلي في الاتجاه الطولي والعرضي ينخفض ​​مع زيادة حجم  الألياف. تم مقارنة نتائج الاختبار التجريبي مع التحليل العددي للإنفعال الكلي وتقييم الاتفاق بين الطريقتين المستخدمتين، الحد الأقصى من التناقض 20٪.The combined effects of thermal and mechanical loadings on the distribution of stress-strain for E-glass fiber /polyester composite plates are investigated experimentally and numerically. The experimental work has been carried out by applying to a uniform temperature and tensile load on the composite plate inside the furnace and the deformation of plate measured by a dial gauge. Two parameter studies, the fiber volume fraction and fiber orientation on the stress-strain for plates subjected to identical mechanical and temperature gradient. The results presented showed that, the maximum absolute of total strain in longitudinal direction occurred at 50 N tension load and fiber angle 60º, while the minimum absolute values of it occurred at 15 N tension loads and fiber angle 0º. However the maximum absolute of total strain in transverse direction occurred at 15N tension load and fiber angle 0º, while the minimum absolute values of it are obtained at 50 N tension loads and fiber angle 60º. Also, the total strain in longitudinal and transverse direction decrease with increasing the fiber volume fraction. Comparison of the results in the experimental test with the numerical analysis of the total strain and evaluated the agreement between the two methods used, the maximum discrepancywas 20%

Semi-Quantitative Dermal Exposure Assessment of Lead with DREAM Model in a Lead Mine in Iran

Occupational exposure to toxic substances occurs in a variety of ways. The DREAM model is suggested for assessing skin exposure using preset values. The purpose of this study is to investigate the exposure of lead in workers at a mine lead using the DREAM model. This research was done in several steps. First, collect information about people and the work environment. Then design the model in Excel2016 by the authors. This research was descriptive-analytic research and included 46 miners. The DREAM model has a total of 33 variables included. In the DREAM model, exposure assessment was performed for 9 body parts at task level 2. The DREAM model was completed for 5 jobs. Jobs were in the lab, tunnel-74, tunnel-34, entrance to the tunnel and flotation workshop. The results were calculated for each of the 9 parts of the site for propagation, transfer, deposition, and potential and actual exposures, and eventually total exposures. The DREAM model, in comparison with similar methods, estimates the skin exposure level in a semi-quantitative fashion. This method has been used to estimate skin exposure in a variety of industries. This method was used to assess the skin exposure of workers in a mine, which resulted in training workers and providing personal protective equipment appropriate to the environment

Prevalence of Self-medication with Antibiotics amongst Clients Referred to Outpatient University Dental Clinics in Iranian Population: A Questionnaire-based Study

Introduction: Self-medication with antibiotics may increase the risk of inappropriate use and development of antibiotic-resistant bacteria. The aim of this study was to determine the prevalence of self-medication with antibiotics amongst dental outpatients in Iranian population.  Methods and Materials: One thousand and two hundred of dentistry patients, who were referred to dental school clinics in ten major provinces of Iran, participated in this study. A valid self-administered questionnaire regarding self-medication with antibiotics in case of dental pain was used to collect data. Data were analysed using descriptive statistics and Logistic regression analysis. Results: In our study population, the prevalence of self-medication was 42.6%. Amongst the Iranian cities, the highest prevalence of self-medication with antibiotics belonged to the city of Bandar Abbas (64%) and the lowest was seen in the city of Kerman (27.3%). Men were more likely to take antibiotics. Amoxicillin was the mostly used antibiotic. Severe pain, previous self-medications and high costs of dental visits were the most common reasons for self-medication with antibiotics in the investigated population. In addition, the present study showed that marriage, acceptable financial status and high level of education could decrease self-medication with antibiotics. Conclusions: In the current investigation, an alarming fact was that self-medication for dental problems seemed very common amongst the studied population. One of its most important consequences was bacterial resistance. Therefore, there should be plans to promote and prioritize public health awareness and encourage general public’s motivation to reduce the practice of self-medication.Keywords: Antibiotics; Dental Clinics; Prevalence; Self-medicatio

Effect of Polyphenol Supplementation on Memory Functioning in Overweight and Obese Adults: A Systematic Review and Meta-Analysis

Negative health consequences of obesity include impaired neuronal functioning and celldeath, thus bringing the risk of impaired cognitive functioning. Antioxidant properties of polyphenolsoffer a possible intervention for overweight people, but evidence for their effectiveness in supportingcognitive functioning is mixed. This review examined evidence from randomized controlledtrials concerning the effect of polyphenols on tasks requiring either immediate or delayed retrievalof learned information, respectively, thus controlling for differences in cognitive processes and relatedneural substrates supporting respective task demands. Searches of the PubMed/Medline,PsycInfo, and Scopus databases identified 24 relevant primary studies with N = 2336 participantshaving a BMI ≥ 25.0 kg/m2. The participants’ mean age for the 24 studies exceeded 60 years. Respectivemeta-analyses produced a significant summary effect for immediate retrieval but not for delayedretrieval. The present findings support a potential positive effect of chronic supplementationwith polyphenols, most notably flavonoids, on immediate retrieval in participants aged over 60years with obesity being a risk factor for cognitive impairment. We recommend further investigationof this potential positive effect in participants with such risk factors. Future research on all populationsshould report the phenolic content of the supplementation administered and be specific regardingthe cognitive processes tested

In Vitro Screening for Antimicrobial Activity of Some Medicinal Plant Seed Extracts

Phytochemical screening (saponins, tannins, steroids, alkaloids, flavonoids, phenols and glycosides) of four medicinal plant seeds (Jatropha curcas, Simmondsia chinensis (Jojoba), Moringa oleifera and Datura metel) extracted by aqueous, ethanol and Folch solvents, were examined for their antimicrobial activity against three types of plant pathogenic fungi namely; Botrytis cinerea, Fusarium oxysporum and Rhizoctonia solani, in addition to four types of bacteria, namely; Bacillus cereus, Staphylococcus aureus, Ralstonia solanacearum and Pesudomonas aeruginosa using disc diffusion paper. Results revealed that different concentrations of aqueous extracts were more effective against bacterial activity compared to fungal activity, except for D. metel aqueous extract which showed no antifungal effect and very weak effect on only two of the tested bacteria. B. cereus was more sensitive to J. curcas aqueous extract, while P. aeruginosa was more sensitive to S. chinensis and M. oleifera aqueous extracts. On the other hand, results showed that J. curcas and M. oleifera ethanol extracts were more effective on Staph. aureus growth, while S. chinensis and D. metel did not have any effect on any of the fungi or bacteria under study. The evaluation of the antifungal and antibacterial effect did not confirm the broad spectrum of S. chinensis Folch extract, while M. oleifera and D. metel were more effective on reducing R. solani growth. Also F. oxysporum was affected by J. curcas Folch extract only at high concentrations. These findings support that the traditional use of the plant extracts in the treatment of different infections caused by pathogenic microbes is valuable and should be taken in consideration

Parametric study on the thermal performance enhancement of a thermosyphon heat pipe using covalent functionalized graphene nanofluids

Heat transfer characteristics of copper sintered heat pipe explored using a modified graphene nanoplatelets (GNP)-containing nanofluid with great dispersion stability as a novel working fluid. Firstly, a water dispersible GNP with specific desire was synthesized by the reaction of GNP sheets with the diazonium salt (DS) of sodium 4-aminoazobenzene-4-sulfonate. An X-ray photoelectron spectroscopy (XPS) test shown successful covalent functionalization of GNP using DS which provided special water dispersibility characteristics. The results indicate that the thermal conductivity enhancement was up to 17% by adding modified GNP sheets in the base fluid. It also, exhibited a maximum sedimentation of 16% after 840 hrs. Further research works were carried on thermal performance of heat pipe by varying nanofluid concentrations, filling ratio, input heating powers and inclination angles of heat pipes. The results proof that the maximum enhancements of the effective thermal conductivity and reduction in thermal resistance for purposed nanofluid atφ = 5% were 105% and 26.4%, respectively. Moreover, these good features of the GNP/DS nanofluid make it a very promising working fluid to enhance the thermal performance and efficiency of the current heat pipe systems

Investigation of thermal conductivity and rheological properties of nanofluids containing graphene nanoplatelets

In the present study, stable homogeneous graphene nanoplatelet (GNP) nanofluids were prepared without any surfactant by high-power ultrasonic (probe) dispersion of GNPs in distilled water. The concentrations of nanofluids were maintained at 0.025, 0.05, 0.075, and 0.1 wt.% for three different specific surface areas of 300, 500, and 750 m(2)/g. Transmission electron microscopy image shows that the suspensions are homogeneous and most of the materials have been well dispersed. The stability of nanofluid was investigated using a UV-visible spectrophotometer in a time span of 600 h, and zeta potential after dispersion had been investigated to elucidate its role on dispersion characteristics. The rheological properties of GNP nanofluids approach Newtonian and non-Newtonian behaviors where viscosity decreases linearly with the rise of temperature. The thermal conductivity results show that the dispersed nanoparticles can always enhance the thermal conductivity of the base fluid, and the highest enhancement was obtained to be 27.64% in the concentration of 0.1 wt.% of GNPs with a specific surface area of 750 m(2)/g. Electrical conductivity of the GNP nanofluids shows a significant enhancement by dispersion of GNPs in distilled water. This novel type of nanofluids shows outstanding potential for replacements as advanced heat transfer fluids in medium temperature applications including solar collectors and heat exchanger systems