Nanocomposite was prepared using unsaturated polyester (UP) resin as a matrix and graphene nanoparticles as a reinforcement material in six percentage weights (0, 0.1, 0.2, 0.3, 1 and 1.5%). Mechanical, calorimetric and thermal studies were performed on the (UP) resin/graphene nanocomposite. All tests showed a clear improvement of all mechanical properties examined (hardness, flexural strength (F.S), impact strength (I.S) and tensile strength (T.S)) with increasing graphene percentage. In addition, the temperature of glass transition and thermal conductivity of this composite increased with increasing graphene content.

The current research aimed to investigate the psychometric characteristics of the Arabic version of the Nomophobia scale for the Omani youth. The scale was administered to a random sample of students from public and private universities and colleges in Oman. The research sample consisted of 2507 students, of whom 868 males and 1639 females. The validity of the measure was first checked by presenting the scale to a group of experts in this field. Then the exploratory and confirmatory factor analysis was carried out. The exploratory factor analysis revealed the existence of three main factors: the fear of connectivity loss, the fear of communication loss with others, and the fear of network outages. These factors accounted for 65.6% of the

The effect of micro-and nano silica particles (silica SiO2 (100 μm), Fused silica (12nm)) on some mechanical properties of epoxy resin was investigated (Young's modulus, Flexural strength). The micro-and nano composites were prepared by using three steps process with different volume fraction of micro-and nano particles (1, 2, 3, 4, 5, 7, 10, 15, and 20 vol. %). Flexural strength and Young's modulus of nano composites were increased at low volume fraction (max. enhancement at 4 vol.% ). However at higher volume fraction both Young's modulus and flexural strength decrease. Moreover, above, the mechanical properties are enhanced more than that of neat epoxy resin. The flexural strength decreases with increasing the volume fraction of micr

Background: The surface properties of the titanium alloy plays a significant role in the bond of the dental implant with living bone and modification of the implant surface could enhance osseointegration. This study was aimed to investigate the effect of different durations of heat treatment on the surface properties of titanium alloy for dental implants. Materials and methods: Twenty disks of (Ti-6Al-4V) alloy were prepared. The sample was divided into four test groups to study the effect of different duration of heat treatment to the surface topography; surface chemistry, titanium oxide layer thickness, blood contact angle, & blood drop diameter of titanium alloy samples were investigated to evaluate the effect of different durations of

This study involves the synthesis of a new class of silicon polymers, designated as P1-P7, derived from dichlorodimethylsilane (DCDMS) in combination with various organic compounds (Schiff bases prepared from different amines and appropriate aldehydes or ketones) [I-V] through condensation polymerization. The structures of all monomers and polymers were characterization by FTIR and 1HNMR spectroscopy (for some polymers). The results of thermogravimetric analysis (TGA) and differential scanning calorimetry DSC test show stable thermal behaviour. Polymers with a higher concentration of aromatic rings in their repeating structural units exhibited a higher temperature for weight loss, indicating increased thermal stability. Thermal meas

In this study, the physical, and mechanical properties of low-cost and biocomposites were evaluated. The walnut shell and date palm frond fibers were thermally treated in an oven at a temperature of 70°C and then chemically treated with NaOH and distilled water solution, after these treatments, the biocomposite materials will be thermally treated again at 50°C. This procedure was performed for three types of biocomposite; Walnut shell Fiber Reinforced Polymer (WFRP), Date palm Fiber Reinforced Polymer (DFRP), and Hybrid Fiber Reinforced Polymer (HFRP), whereas the biocomposite sheets consisting of 30% biofibers and 70% unsaturated polyester, the mechanical test specimens were cut by a CNC machine according to ASTM standards. The e

The present study aims at identifying the effect of organizational pressure with its aspects (management, work team, nature and conditions of work, external environment) on job performance in all its dimensions (commitment and effort made, capabilities and the rapidity of performance, motivation and job satisfaction, work environment) for the university teacher at the Faculty of Economics, Commercial and Management Sciences at the University of Djelfa, Algeria.

     In this research, the descriptive analytical approach is used. Data was collected through the distribution of a questionnaire to a sample that included 130 permanent teachers before being analyzed using the (SPSS) statisti

Background: The bond strength of the root canal sealers to dentin is very important property for maintaining the integrity and the seal of root canal filling. The aim of this study was to evaluate and compare the push-out bond strength of root filled with total fill Bioceramic, AH Plus and Gutta-flow®2 sealers using GuttaFusion®obturation system versus single cone obturation technique. Materials and method: sixty of mandibular premolars teeth with straight roots were used in this study, these roots were instrumented using Reciproc system, instrumentation were done with copious irrigation of 3 mL 5.25% sodium hypochlorite solution (NaOCl) during all the steps of preparation, and smear layer will be removed with 1 ml of 17% EDTA kept in

Background: The bond strength of the root canal sealers to dentin is very important property for maintaining the integrity and the seal of root canal filling. The aim of this study was to evaluate and compare the push-out bond strength of root filled with total fill Bioceramic, AH Plus and Gutta-flow®2 sealers using GuttaFusion®obturation system versus single cone obturation technique. Materials and method: sixty of mandibular premolars teeth with straight roots were used in this study, these roots were instrumented using Reciproc system, instrumentation were done with copious irrigation of 3 mL 5.25% sodium hypochlorite solution (NaOCl) during all the steps of preparation, and smear layer will be removed with 1 ml of 17% EDTA kept in

This research was conducted under Lath house canopy of a nursery circumstances, Baghdad University for season 2013 in order to study the effect of soak lemon seeds sour orange with different levels of licorice concentrations extract (0, 0.5, 2.5 and 4.5 g/l) for 24 hours in the percentage of germination and some recipes vegetative growth of seedlings .the results outweigh the bitter orange seedlings and focus soak for licorice extract 4.5 g / l significant superiority in most of the traits plant height, leaf number, root length, stem diameter, amounting to 31.077 cm, 14.46 paper / plant, 25.35 cm, 0.52 mm respectively, which showed significant differences for the treatment of comparison which gave lower values. Clear that the licorice ext