We have theoretically investigated the in-plane lattice thermal conductivity of Zn4Sb3single quantum well structure taking into account spatial confinement of phonons. The calculations were carried out for free-surface quantum wells with thickness 8.5nm in the room temperature. We show that the lattice thermal conductivity is a significant reduce. The reduction is mostly due to the drop in the average group velocity caused by the spatial confinement of acoustic phonons and the corresponding increase in phonon relaxation rates. The predicted decrease is important for the anticipated applications of Zn4Sb3 nanostructure materials for room-temperature thermoelectric devices. Our theoretical results are in a good agreement with available experimental data for Zn4Sb3 quantum wells
The purpose of the current research is to identify the most important problems that primary school students suffer from inside and outside the classroom from the point of view of their teachers. A sample of (100) male and female teachers was chosen from the Rusafa\ second Directorate for the academic year (2018-2019). The research tool was prepared after reviewing literature related to the issue of problems and difficulties facing students or students in the school stage and even at university. The researcher reached several results that were discussed in the fourth chapter, with a set of conclusions based on the results of the research, and come up with several recommendations and suggestions.
Background: This study aimed to determine the cephalometric values of tetragon analysis on a sample of Iraqi adults with normal occlusion. Material and methods: Forty digital true lateral cephalometric radiographs belong to 20 males and 20 females having normal dental relation were analyzed using AutoCAD program 2009. Descriptive statistics and sample comparison with Fastlicht norms were obtained. Results: The results showed that maxillary and mandibular incisors were more proclined and the maxillary/mandibular planes angle was lower in Iraqi sample than Caucasian sample. Conclusion: It's recommended to use result from this study when using tetragon analysis for Iraqis to get more accurate result.
Absract
The letters of the Al-Safa Brothers contain many tales, in which each story is a literary text that is independent from the other texts, but it constitutes a unified entity in its entirety, because these stories contain recurring structural elements that go into building each one of them. The stories - the subject of the analysis - were not keen on something that was keen on adhering to the Sufi vision and its apparent effect on the tales of the messages, starting with the announcement of the narration to the narrator and his attempt to persuade the recipient of the truth of what is being told and its realism, and made him believe it. The stories correspond to the formal construction of the ideal style defined by th
... Show MoreFind the impediments Activity vital and important, but focuses a bancassurance activity, diagnosis and its impact on the financial ratios indicators for insurance companies. The researcher has adopted in his research on several financial ratios used to analyze the financial performance of a (relative profitability, liquidity ratio and the ratio of solvency) of the company Iraqi insurance for a period of one year (2009) to a year (2015), based on the annual reports and financial statements (balance sheet revealed income), financial statements for insurance premiums for banks research sample of this research has addressed several topics of theoretical and practical body through which the researcher obstacles to banking and insurance experi
... Show MoreThe extraction behaviour of a secondary amine (Dioctylamine) and a combination of secondary amine and tertiary amine (Tricapryl amine) toward some of the metal ions were investigated. Two types of diluents were applied, namely, mesitylene and treated Kerosene fraction. The extractability of dioctylamine and different combinations of tertiary amine and secondary amine toward uranium were investigated. The distribution coefficients and the separataion factors of uranium from the metal ions were calculated.
The images and drawings reduce the intellectual, symbolic and cognitive dimensions inside them that make them an intermediary that imposes itself on the educational method, as they have become responsive to all the needs of the student in the modern era unlike the previous periods. The artistic direction of the illustrations in the scientific books meets the educational and pedagogical needs of the learner and their frame in an illustrative educational method that contributes in developing the student's abilities to benefit from the scientific curricula in the age of scientific and cognitive development.
Here, the researcher finds that the artistic direction of the illustrations lacks the achievement of scientific and technical p
... Show MoreObjective: The aim of this study is to evaluate anemia among lactating women and their children less than 2 years of
age.
Methodology: The study was done on (148) lactating mothers and their children under 2 years of age in the primary
health care center at AL-Salam Quarter/Baghdad from l/10/2009 to 15/10/2010.
Result: This study recommends that there is a significant relationship between anemic mothers and their children. The
study also revealed that there is (77.8%) from nursing mothers in the age groups (25-29) who suffered from anemia,
while (23.1%) for the age group (20-24) did not have anemia
Recommendation: We encourage the use of breast milk or iron-fortified infant formula only for any milk-based part
of
Abstract:
One of the most prominent historical stage feature that is well- known
nowadays in the world is democracy issue. This issue gives man the right to
reflect his concept and notions . It,s the world of freedom , human right and
liberation of women. This leads to the principle of equality between women
and men which is put in the top of liberty and Improvement lists .
Improvement can be defined as a group of means and ways that is
used to direct human work to improve their level of life economically and
socially .
This study contains three sections, the first presents the social state of
women in pre-history period . And the second section presents the theory of
improvement as an important social ph
The research aims to evaluate the radioactivity in elected samples of cereals and legume which are wide human consumption in Iraq using Nuclear Track Detectors (NTDs) model CN-85.
The samples were prepared scientifically according to references in this field. After 150 days of exposure, the detector were collected and chemically treated according to scientific sources (etching chemical), nuclear effects have been calculated using the optical microscope.
Radon (222Rn) concentration and uranium (238U) were calculated in unit Bq/m3 and (ppm), the results indicate that the highest concentration of radon and uranium was in yellow corn where the concentration of radon was 137.17×102 Bq/m3 and uranium concentration 2.63 (ppm). The lowest
This study is a try to compare between the traditional Schwarzschild’s radius and the equation of Schwarzschild’s radius including the photon’s wavelength that is suggested by Kanarev for black holes to correct the error in the calculation of the gravitational radius where the wavelengths of the electromagnetic radiation will be in our calculation. By using the different wavelengths; from radio waves to gamma ray for arbitrary black holes (ordinary and supermassive).