In this work, ZnO quantum dots (Q.dots) and nanorods were prepared. ZnO quantum dots were prepared by self-assembly method of zinc acetate solution with KOH solution, while ZnO nanorods were prepared by hydrothermal method of zinc nitrate hexahydrate Zn (NO3)2.6H2O with hexamethy lenetetramin (HMT) C6H12N4. The optical , structural and spectroscopic properties of the product quantum dot were studied. The results show the dependence of the optical properties on the crystal dimension and the formation of the trap states in the energy band gap. The deep levels emission was studied for n-ZnO and p-ZnO. The preparation ZnO nanorods show semiconductor behavior of p-type, which is a difficult process by doping because native defects.
The current research seeks to shed light on the role that social media can play, through the optimal use of it by students, in achieving academic excellence. The most prominent aims that constitute it are:Identifying the social sites most used by students; learning how students interact with the published study material on communication sites and benefit from them to achieve their academic excellence; and knowing the connection between using social media and achieving academic excellence, and the role that these sites play in achieving academic excellence.That incorrect use by students leads to adverse results, and thus affects their academic level. Failure of parents to monitor their student’ use of social media leads
... Show MoreDuring the course of fixed orthodontic therapy, patients should be instructed to eat specific food stuffs and beverages in order to maintain good health for the dentition and supporting structures and prevent frequent attachment debonding that prolong the treatment duration. After searching and collecting articles from 1930 till July 2021, the current review was prepared to emphasize various types of foods that should be taken during the course of fixed orthodontic therapy and to explain the effect of various food stuffs and beverages on the growth and development of craniofacial structures, tooth surfaces, root resorption, tooth movement, retention and stability after orthodontic treatment and the effect on the components of fixed ortho
... Show MoreTo track scientific developments and achievements, for example, that (achieved) after the Second World War until this moment, make each of us in absolute amazement. He invented the computer, discovered the genetic factor (DNA), and discovered the drawing of the human genetic map, going up to the moon, penetrating outer space by satellites, getting close to distant planets, producing jet planes, microprocessors, and lasers, in addition to enabling a person to create a layer of The material is extremely thin and extremely imaginative. It has also become possible for a person to "dig lines that do not exceed 20 billion meters of thickness." The human being was also able to collect things an atom and build an efficient and high-precision con
... Show MoreSpeech is the ability of communication or expression of thoughts among people in spoken words. Human communication via speech is essential since any impairment in this process may have serious social and occupational consequences. Malocclusion is a possible cause of speech impairment in addition to many other etiological factors like hearing loss, neurological disorders, physical disorders, and drug abuse. This article throws light upon the association between speech disorders and malocclusion.
The research talks about the concept of investment allocations, showing its linguistic and idiomatic meaning, as well as the objectives for which the investment allocations are based, as well as the benefits of these allocations since it shows types of investment contracts, including: current and fixed assets and commitment allocations.
The research has been concluded with several results, including the protection of the banks and the investor. The contracting parties focus on specific dates that both parties are obliged to abide by, the research also shows the jurisprudence provisions for investment allocations, each ruling according to the specific branch.
... Show MoreBackground: Gingival recession is defined as the apical migration of the gingival margin below the cementoenamel junction (CEJ), resulting in exposure of the root surface and it is one of the main esthetic complaints of patients. The management of gingival recession and its sequelae is based on a thorough assessment of the etiological factors and the degree of tissue involvement.
Background: Dyslipidemia is a major cause of
cardiovascular disease, which in turn, is the most
common cause of female morbidity and mortality.
Postmenopausal women (natural and surgical) are at
higher risk of developing cardiovascular disease,
especially coronary artery atherosclerosis.
Objective: To observe the relationship between blood
lipids: total cholesterol (TC), high density lipoproteincholesterol (HDL-C), low density lipoproteincholesterol (LDL-C), triglycerides (TGs), and very low
density lipoprotein- cholesterol (VLDL-C), LDL-C/
HDL-C ratio (atherogenic index) and menopausal
status, and to determine the co-factors that may explain
this relationship
Methods: A prospective, cross-sectional st
ABU OBAYDA and Syntax Studies
Background: An important factor influencing duration of breastfeeding is mother’s employment status. The nutritional, immunological, psychological and economic benefits of breastfeeding are well documented. Both UNICEF and the World Health Organization recommend mothers should breastfeed exclusively for at least 6 months.
Objectives: To determine how the employment and the employment variables (type of work, time of return to work and hours of work) influence the breast feeding practices.
Methods: A cross- sectional study was carried out on a sample of 200 employed mothers who had their last child been completed at least tow years. Data were collected using a questionnaire form. It was carried out during the period from 1st of Ap
This research aims to deal with contemporary knowledge methodology to correlate between operations strategy and technological change or modernization in productive paths for industrial organizations depend on practical indicators for competitive priorities that is objectives of operations performance.
The research is based on main hypothesis, concentrates on determination of technological change which is decided by the level of technology deterioration in current operations path compared with the competitors leaders-technology leaders.
We apply these concepts on hypothetical case to two similar companies in their production nature and te
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