Background Alloys with the addition of zirconium and niobium eliminate the adverse effects of aluminum and vanadium on the nervous system, the possibility of metallosis and the initiation of diseases (including cancers or Alzheimer›s disease). In addition, they have better corrosion resistance, and a Young›s modulus value similar to longitudinal bone tissue. Therefore, only choosing appropriate materials does not guarantee proper functioning of the implants, the surfaces of the implants also have to be suitable to meet the requirements. The laser surface hardening process modifies the surface properties by imparting microstructural changes, whereas surface remelting induces changes in the surface topography, roughness, wettability and wear and corrosion resistance, influencing the biocompatibility of the surface. Such changes are brought in essentially because of the characteristic melting, evaporation and rapid solidification during laser surface remelting processes. Objectives This study was aimed at evaluating the electrochemical corrosion of commercial pure Titanium disks (CP Ti) and the Ti13Zr13Nb (Alloy) with a zigzag pattern of laser surface treatment. Materials and Methods a total of 40 discs of Cp Ti & 40 of Ti13Zr13Nb were fabricated. The surfaces of the test groups were treated with unique zigzag patterns using CNC Laser treatment on the texturing surfaces, the samples then are analyzed by using XRD, microhardness and electrochemical corrosion tests. Results The study revealed a proper increase in the surface hardness and corrosion resistance without crack formation or a dramatic change of the core substance of the CP Ti and Alloy disks. Conclusion The CNC laser is considered an effective and suitable method for surface texturing of CP Ti and Alloy for dental implantology.
In this research, the study of thermal treating by laser, plasma glow discharge and tubular furnace on Ti-6Al-4V alloy coated with hydroxyapatite by methods of dip coating and electrophoretic deposition .A group of samples was coated by dip coating and another group was coated by electrophoretic deposition. The first group was treated by pulse laser 10 (mJ) as energy for samples from both coating with uniform distributed pulses on every single sample surface, The second thermal treating was made by plasma glow discharge in a locally made system with argon atmosphere, 600 Volt , and 6 cm distance between the electrodes, The third treating was made by tubular furnace in air atmosphere and 400 °C for 1 hour duration. T
... Show MoreTi6Al4V alloy is widely used in aerospace and medical applications. It is classified as a difficult to machine material due to its low thermal conductivity and high chemical reactivity. In this study, hybrid intelligent models have been developed to predict surface roughness when end milling Ti6Al4V alloy with a Physical Vapor Deposition PVD coated tool under dry cutting conditions. Back propagation neural network (BPNN) has been hybridized with two heuristic optimization techniques, namely: gravitational search algorithm (GSA) and genetic algorithm (GA). Taguchi method was used with an L27 orthogonal array to generate 27 experiment runs. Design expert software was used to do analysis of variances (ANOVA). The experimental data were
... Show MoreIn this study a DFT calculation on cyclopropanone, cyclopropandione and cyclopropantrione molecules was performed using the basis function 6-31G ** / MP2 and exchange correlation potential B3-LYP. The results showed that the ground state of all molecules geometry belong to the point group ð¶2ð‘£where a vibronic coupling between the vibrational motion with the electronic ground state in the molecule C3O3 this leads to a reduction in symmetry of the molecule fromð·3ℎto ð¶2ð‘£, the driving force of this process is accessing to the electronic configuration complies with Hückel aromatic systems with two electrons. Also in this, study the normal modes of vibration, frequencies, intensities and symm
... Show MoreAim: This study aimed to investigate the impact of rabbit serum on skin wound healing with the help of histological examination. Materials and Methods: A total of ten indigenous rabbits were used in this study. The animals were divided into two groups: control and serum- treated. The histological assessment was done with a paraffin embedding technique and the histological sections were stained with H&E stain. Results: Severe infiltration of polymorphonuclear leukocytes with severe fibrin deposits were seen in serum treated group at 2 days post-injury; at 7 days post-injury the changes revealed moderate fibroplasia, fibrin deposit and severe infiltration of both mononuclear and polymorphonuclear leukocytes; at 14 days post-inju
... Show MoreAbstract Objective: To assess nurses' beliefs toward reporting suspected child abuse. To achieve the objectives of the study a questionnaire of child abuse was used. Methodology:- The sample of the study consist of (224) registered nurses who were employed in general hospitals, pediatric hospitals, National psychiatry and mental illness center, nursing colleges, nursing schools. Data were collected from 20 April 2004 to 20 June 2004.Data were analyzed through the application of descriptive statistical analysis. Percentage frequency and mean and inferential data analysis ANOVA. Results: - The result of t
Aims: To assess the success rate and implant stability changes of narrow dental implants (NDIs) during the osseous healing period. Materials and methods: This prospective observational clinical study included 21 patients with narrow alveolar ridge of restricted mesiodistal interdental span who received NDIs. The alveolar ridge width was determined by the ridge mapping technique. Implant stability was measured using Periotest® M immediately after implant insertion then after 4 weeks, 8 weeks and 12 weeks postoperatively. The outcome variables were success rate and implant stability changes during the healing period. The statistical analysis included one-way analysis of variance (ANOVA) and Tukey\'s multiple comparisons test, values < 0.05 w
... Show MoreObjectives: The study aims to assess the female adolescents’ risk-health behaviors, to identify their
determinants, to determine the association between the risk health behaviors and the stage of
adolescence for these females' demographic variable.
Methodology: A purposive sample of (268) female adolescents is selected from intermediate and
secondary schools in Baghdad City. These adolescents have presented the age of (14-19) year old and
divided into two groups of (14-16) year and (17-19) year. A questionnaire is constructed for the purpose
of the study, it is composed of (10) major parts, and the overall items, which are included in the
questionnaire, are (106) item. Reliability and validity of the questionnaire
Objective: To assess the nurses-midwives' knowledge and practices regarding the management of second stage
of labor and to find out the association between their knowledge and practices and socio-demographic
characteristics and working years and experience.
Methodology: A descriptive study was carried out from March 22nd
, 2008 through 30th June, 2008. A purposive
sample of (75) Nurse-Midwives which was selected from (6) hospitals. A questionnaire was comprised of two
parts: (socio-demographic characteristics and the assessment tool for Nurse-Midwives' knowledge and health
practices performed by them). The questionnaire validity was determined by experts and its reliability was
determined through a pilot study. Th
Background: Ejection fraction have been used frequently
for assessment of the left ventricular function, but can be
associated with errors in which myocardial performance
index have been used as another parameter to measure the
left ventricular function.
Objective: selecting another echocardiography parameter
for the assessment of myocardial in function instead of the
ejection fraction.
Methods: 160 patients referred to the echocardiogram unit
from the period december 2007 to august 2008 requesting
assessment of left ventricular function. After clinical
examination, routine blood tests; chest x-ray and
electrocardiographic recording have been completed. All
patients informed to come for this unit af