The objective of this paper was to study the laser spot welding process of low carbon steel sheet. The investigations were based on analytical and finite element analyses. The analytical analysis was focused on a consistent set of equations representing interaction of the laser beam with materials. The numerical analysis based on 3-D finite element analysis of heat flow during laser spot welding taken into account the temperature dependence of the physical properties and latent heat of transformations using ANSYS code V.10.0 to simulate the laser welding process. The effect of laser operating parameters on the results of the temperature profile were studied in addition to the effect on thermal stresses and dimensions of the laser w
... Show MoreThin films of cadmium sulphoselenide (CdSSe) have been prepared by a thermal evaporation method on glass substrate, and with pressure of 4x10-5 mbar. The optical constants such as (refractive index n, dielectric constant ?i,r and Extinction coefficient ?) of the deposition films were obtained from the analysis of the experimental recorded transmittance spectral data. The optical band gap of (CdSSe) films is calculate from (?h?)2 vs. photon energy curve. CdSSe films have a direct energy gap, and the values of the energy gap were found to increase when increasing annealing temperature. The band gap of the films varies from 1.68 – 2.39 eV.
Background: Preparation of platelet-rich fibrin (PRF) is a simple, low cost and minimally invasive method to obtain a natural concentration of autologous growth factors that is widely used to accelerate soft and hard tissue healing, thus, PRF is used in different fields of medicine. The aim of this study was to evaluate the effect of local application PRF on stability of dental implants. Materials and methods: nineteen healthy patients with adequate alveolar bone with two or more adjacent missing teeth and/or bilaterally symmetric to the midline (split-mouth design) missing teeth participated in this study. Each patient received at least two dental implants (Dentium Co., Korea). After surgical preparation of the implant sockets, the PRF was
... Show MoreLeishmania is auxotroph to folic acid,antifolates drug inhibit the synthesis and conversion of folate derivatives. In this study, cytotoxic effect of methotrexate was investigated on the procyclic promastigotes proliferation of L. donovani. The results showed a significant (p ≥ 0.05) difference in growth of treated groups at high concentrations (1000, 500, 250, 125.5) μM after 24, 48 hrs., while at 72 hrs. significant difference was observed at all concentration. The IC50 values was measurable after 24, 48 and 72 hrs. and it was 174.238, 52.283 and 109.175 μM, respectively. The present study showed the cytotoxic effect of methotrexate on the proliferation of promastigotes of the visceral type of Leishmania.
This paper investigates the issue of surface-type effects on traffic noise in Baghdad. Since the raw materials for both flexible and rigid paving are available from local sources, the decision on selecting the type of paving which depends on the budget of the project and the road's importance and function. Knowing that for high traffic volumes and a high percentage of heavy vehicles, rigid pavement is more suitable compared to flexible pavement. In Baghdad, some highways consist of flexible pavement and others of combined pavement (flexible segments and rigid segments), so the study of the effect of surface type on traffic noise becomes an important matter. This study selected three highways: one with flexible pavement a
... Show MoreWidely present in the environment, arsenic trioxide has been identified as a genotoxic substance that poses a serious risk to public health. The genotoxic potential of arsenic at low allowable dosage levels is assessed in this study. Four groups of twelve adult rats each were created from the 48 total. Animals in Group I were used as controls Chromosome abnormalities found in bone marrow cells were used to assess the mutagenic potential of arsenic. Hematological parameters were also assessed. At 60 and 90 days, the percentage of microsomal degranulation in the hepatic fraction increased and the amounts of RNA and proteins considerably reduced (P < 0.01) in all three dosages given. was employed in order to assess hematological par
... Show MoreThe predisposing factors and their effect on the increasing of vulvovaginal Candidiasis have been studied in this research. The result indicated that the highest of infection with vaginal Candidias was in the age of women with age of (21-30years) with vaginal itching and discharge, also the results revealed that the pregnancy was the main predisposing factor. The percentage of the infected pregnant Ladies was 33.7% followed by the women who used the IUCD and OCP 22.1%, those who used steroids 5.2% comparing with control women (without predisposing factors).The results also indicated that the most cases of infection were during the third trimester of pregnancy (where the rate of infedion) was 53.9%.-OCP- Oral Contraceptive Pills-IUCD- Intrr
... Show MoreLaser beam has been widely used to improve the mechanical properties of the metals. It used for cutting, drilling, hardening, welding……etc. The use of Laser beam has many features in accuracy and speeding in work, also in the treatment of metals locally, and in the places that is hard to reach by traditional ways. In this research a surface treatment was done to medium carbon steel (0.4%C) which is common kind of steel that is used in industry. Pulsing Neodymium -YAG Laser has been used and 1.06 micrometer wave length and 5 msec and the distance is about 30 centimeter between the exit area of the Laser beam from the system and the piece that treated . We are going to check the fatigue resistance for samples that is
... Show More
