ZnO nanostructures were synthesized by hydrothermal method at different temperatures and growth times. The effect of increasing the temperature on structural and optical properties of ZnO were analyzed and discussed. The prepared ZnO nanostructures were characterized by X-ray diffraction (XRD), UV–Vis. absorption spectroscopy (UV–Vis.), Photoluminescence (PL), and scanning electron microscopy (SEM). In this work, hexagonal crystal structure prepared ZnO nanostructures was observed using X-ray diffraction (XRD) and the average crystallite size equal 14.7 and 23.8 nm for samples synthesized at growth time 7 and 8 hours respectively. A nanotubes-shaped surface morphology was found using scanning electron microscopy (SEM). The optical properties showed that the samples had good absorbance in the UV-Vis. region and wide band gap. The PL spectrum displayed that the intensity of ultraviolet (UV), band gap and defect bands depend on the growth temperature of the ZnO nanostructure. The largest band gap was 3.351 eV for ZnO nanostructure synthesized at 100 °C and growth time 8h.
The first chapter includes introduce the research and the problem of the research that there are negligence of some educational institutions and schools management , some parents and supervisors .Also there are some educators who believes that school activities are obstacles means to learning and prevent pupils from studying and understanding the subjects. That may due to social , psychological and educational reasons
The purposes of the researches come from the reports of supervision visits which indicate a lot of difficulties faced by pupils and teachers related to education activities and its influence on in education and the necessity of indentify these difficulties and remedy them
... Show MoreBackground: Self-medication is a practice or action taken by individuals for themselves in order to achieve and maintain health, as well as to avoid and protect against disease. The aim of this study is to evaluate the knowledge, attitudes, and practice of self-medication among medical students at Sudan International University.
Subjects & Methods: This was a prospective study that involved 288 out of 1000 students in the Faculty of Medicine at Sudan International University. Data were collected using a self-administered questionnaire from January to March 2022 to evaluate the self-medication knowledge, attitude, and practice among first, second, and third-ye
... Show MoreIraqi bentonite is used as main material for preparing ceramic samples with the additions of alumina and magnesia. X-ray diffractions analyses were carried out for the raw material at room temperature. The sequence of mineral phase's transformations of the bentonite for temperatures 1000 ,1100 ,1200 and 1250 ºC reflects that it finally transformed in to mullite 39.18% and cristobalite 62.82%. Samples of different weight constituent were prepared. The effect of its constitutional change reveals through its heat treatments at 1000,1100,1200,1250and 1300ºC .The samples of additions less than 15% of alumina and magnesia could not stand up to 1300ºC while the samples of addition more than 15% are stable .That is shown by analy
... Show MoreObjective: To assess mothers' knowledge and practices concerning cholera and their relationship with some
sociodemographic characteristics of those mothers.
Methodology: A sample of (100) mother was selected through a convenience sample for the period of July First
through August 31 2007 '؛
. Data were collected through interview of mothers were visiting PHC centers by using
of constructed questionnaire developed by the researcher that contains (31) item. Reliability and Validity of the
tool were determined through pilot study. A descriptive and inferential statistical approaches were used for data
analysis.
Results: The study indicated that mothers’ knowledge and practices concerning cholera were unacceptable
Abstract
This work involves the manufacturing of MAX phase materials include V2AlC and Cr2AlC using powder metallurgy as a new class of materials which characterized by regular crystals in lattice. Corrosion behavior of these materials was investigated by Potentiostat to estimate corrosion resistance and compared with the most resistant material represented by SS 316L. The experiments were carried out in 0.01N of NaOH solution at four temperatures in the range of 30–60oC. Polarization resistance values which calculated by Stern-Geary equation indicated that the MAX phase materials more resistant than SS 316L. Also cyclic polarization tests confirme
... Show MoreObjectives: This study aims to determine the disease’s patterns and outcomes of admission among neonates hospitalized at the neonatal care unit in Erbil City, and using the findings as a baseline for neonate’s morbidity and mortality assessment in the future. Methodology: A retrospective study carried out at neonatal care unit of Raparin pediatric teaching hospital. An instrument for data collection developed by researcher included (age, gender, cause of admission, diagnosis and outcome upon discharge and causes of death). Content validity of the instrument was determined through the use of panel ex
Objective: The study aimed to identify the adolescents' fast foods and snacks, and find out the relationship between fast
food, snacks and adolescents' demographic data (gender and Body Mass Index). Methodology: A descriptive study
was conducted on impact of fast foods and snacks upon adolescents' Body Mass Index in secondary schools at Baghdad
city, starting from 20
th of April 2013 to the end of October 2014. Non- probability (purposive) sample of 1254
adolescents were chosen from secondary schools of both sides of Al-Karkh and Al-Russafa sectors. Data was collected
through a specially constructed questionnaire format include (12) items multiple choice questions. The validity of the
questionnaire was determined thr
Zooplanktons from the artificial lake of Madenat Al-Alaab at Baghdad city have been
studied, during the period from may 2009 to April 2010. In addition to some ecological
factors (Temperature, pH and Turbidity) which were ranged (10.2-28.4)°C (7.1-8.4) and (20-50) cm respectively.
The results of the present study revealed that there are 22 species of zooplankton
belonging to Cladocera, Copepoda and Rotifera. Some of the species recorded during all
months of the study period, while other have disappeared during some months. Numbers of
species recorded were varied during different groups .
The dominant species were (Cyclops vernalis, C. hyalinus, C. scutifer, Diaptomus
leptopus, Bosmina longirostris, Kerate