Whereas conventional methods of teaching history do not meet the sometimes purpose has suggested some educators strategies modern help to improve the level of students in the education process through activating prior knowledge and employed in positions of current learning, and focus attention on the points and the outstanding elements of the content and practice techniques Calendar criticof ideas and meanings and mental and linguistic activities used to verify the extent of reaching understanding. &n
... Show MoreThe current research attempts to examine the relationship between social-psychological conflict and their relation to family upbringing approaches among the adolescents of intermediate stage according to sex and economical level. To do this, the researcher prepared a questionnaire to measure social-psychological conflict that consisted of (32) item divided on four dimensions, and also she prepared a questionnaire to measure family upbringing approaches which composed of (28) item divided on four dimensions. The sample was (260) male and female student from intermediate stage chosen randomly. The results revealed that there were significant differences between social-psychological conflict which went to male, there was a negative correlat
... Show MoreThe photodynamic inactivation against Methicillin-resistant Staphylococcus aureus using two different lasers, 532 nm diode pumped solid state laser (DPSS) in combination with safranin O and 650 nm diode laser in combination with methylene blue was investigated in the present work. A hundred swab samples were collected from patients with burn and wound infections admitted to two hospitals in Baghdad (Specialized Burns Hospital in Medical City and Al Imamein Al Jwadein Medical City Hospital) from December 2015 to February 2016 Antimicrobial susceptibility was performed by using Kirby- Bauer method. The irradiation experiments included four groups; a control group, a photosensitizer only group, a laser irradiation only group and a laser irr
... Show MoreIn the present research a new test rig has been proposed to be suitable for different cyclic loads such as cyclic bending, cyclic torsion, proportional and non proportional loads. In this work the efforts were concentrated on the cyclic bending loads concerning cracked pipes with or without internal pulsing pressure to study crack propagation in small bore pipes (up to 1'') for transverse or inclined cracks. The rig simulates the real service conditions under different stresses by means the least dangerous case will be suggested, so the experiments were considered for copper pipe, and the results have been tabulated and drawn to demonstrate the crack growth behavior as well as to justify the outcomes practically, consequently the durabil
... Show MoreIn this work, varying compositions of SiO2 micro filler were added
with the Polyvinyl Chloride (PVC) and samples have been prepared
using film casting technique. The results have been analyzed and
compared for PVC samples with (1 wt%, 3 wt%, 5 wt% and 10 wt%)
SiO2 micro filler. Mechanical characteristics such as tensile strength,
elongation at break and Young`s modulus were measured for all the
samples, where the tensile strength was increased from 8.39 Mpa for
purified PVC to 16 Mpa for 3% SiO2/PVC composite. Also, thermal
conductivity measurement values illustrated that composite materials
have a good thermal insulation at 10 wt. %, thermal conductivity was
decreased from 0.1684 W/m.
Background: Poly (methylmethacrylate) is the most widely used material in denture fabrication. The characteristics of acrylic resin which support microorganism development can threaten the oral health of denture users. This study was assigned to prepareand incorporate Ag-Zn zeolite powder into heat cured denture base material as antimicrobial material and to investigate its effect on some properties of heat cured acrylic denture base materials. Materials and methods: Sliver –zinc zeolite was prepared by ion exchange method and characterized then incorporated into poly (methylmethacrylate) powder in0.5% by weight. Specimens were constructed and divided into 6 groups according to the using tests; each group was subdivided into 2 groups
... Show MoreThe study was conducted to identify the toxicity of chromium on scenedesmus quadricauda algae alone and in the presence of nutrient metal (Nitrogen). Different concentrations of chromium (0.5, 1.5 , 2.5, 3.5 , 4.5mg/L) were used and the presence nitrogen is (5 ,10 ,50 ,100mg/L) on cultur media(chu-10) with used for cultivation of the algae in controlled conditions(25oC , light intensity 380 –?E/m2 /s. The results showed increasing in the toxicity of the metal when is alone , excess of concentrations an time of exposure. The growth rate decreased from 0.44 to 0.06 cell/ hour after 12 day of the biging of the experiment and of concentrate 4.5 mg/L of chromium. The intermediate active concentrations of the chromium(EC50) was increase
... Show MoreBackground: Elastomeric chains are one of the most commonly used force delivery systems. They have the ability to exert a continuous force, convenience of use, compatibility to oral environment and cost effectiveness but one of the inherited disadvantages is force degradation. Materials and methods: This in vitro study was designed to evaluate the effect of alcohol presence in mouthwashes on force decay of different configurations of clear elastomeric chains from (Ortho Technology company) which are: closed , short and long under the effect of time at (Initial, 1, 2, 3 and 4 weeks) intervals with exposure to different chemical solutions. A total (540) modules of elastomeric chains of three different types (long, short and closed) trans
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