Preferred Language
Articles
/
JRbKtIcBVTCNdQwCSV1t
The influence of temperature and size on the absorption coefficient of CdSe quantum dots
...Show More Authors
Abstract<p>Because of Cadmium selenide quantum dots (CdSe quantum dots) has a tuning energy gap in the visible light range, therefore; it is provided a simple theoretical model for the absorption coefficient of CdSe quantum dots, where the absorption coefficient determines the extent to which the light of a material can penetrate a specific wavelength before it is absorbed. CdSe quantum dots have an energy gap can be controlled through two effects: the temperature and the dot size of them. It is found that; there is an absorption threshold for each directed wavelength, where CdSe quantum dots begin to absorb the visible spectrum at a size of 1.4 nm at room temperature for a directed wavelength 300 nm. It has been observed that; when the wavelength is increasing its absorption threshold is increased. For wavelengths (400, 500, 600) nm, the absorption thresholds for each quantum sizes are (1.8, 2.2. 3.2)nm respectively. On the other hand, a rising of the temperature led to reduces the absorption coefficient value, that at 400 K for all quantum sizes, the absorption coefficient increases >2000cm<sup>−1</sup>(According to the directed wavelength) than it is at 0 K. CdSe quantum dots can be considered as one of the most promising materials because it has a tuning gap for the visible wavelengthsfor different applications, such as light-emitting diodes in different colors of the visible spectrum. It is found that; there is a good agreement between our theoretical calculations and experimental results.</p>
Crossref
View Publication
Publication Date
Wed Jul 01 2015
Journal Name
Journal Of Engineering
Enhancing the Performance of Piezoelectric Energy Harvesters Using Permanent Magnets
...Show More Authors

A cantilevered piezoelectric beam with a tip mass at its free end is a common energy harvester configuration. This paper introduces a new principle of designing such a harvester which increases the generated voltage without changing the natural frequency of the harvester: The attraction force between two permanent magnets is used to add stiffness to the system. This magnetic stiffening counters the effect of the tip mass on the natural frequency. Three setups incorporating piezoelectric bimorph cantilevers of the same type in different mechanical configurations are compared theoretically and experimentally to investigate the feasibility of this principle. Theoretical and experimental results show that magnetically stiffe

... Show More
View Publication Preview PDF
Publication Date
Wed Dec 15 2021
Journal Name
Al-academy
Employment of health materials in the internal administra-tive spaces
...Show More Authors

 The internal administrative spaces of the interior designer formed an obsession for their development and for finding solutions and treatments to advance to enhance the state of adaptation for their employees by providing a healthy, appropriate and sound environment for work and production. . The first chapter focuses on laying theoretical foundations to show what health materials are used in the administrative spaces of the training directorates of the Ministry of Education in Baghdad. The second chapter dealt with the knowledge of health materials, their impact and effectiveness in the interior space, and the variables of their functional characteristics and their work in the interior spaces in a way that enhances the development of

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Jan 01 2021
Journal Name
Journal Of Economics And Administrative Sciences
Technical analysis of the salary scale for public sector employees
...Show More Authors

            The research discusses the mechanism for analyzing the salary scale in the public sector through an analysis of grades, their stages, occupants and their financial entitlements, and the extent to which the information obtained for their investment in strategic planning, conducting correction and treatment can be used. The salaries of the employees in them, whose number is (1117) employees, to be a field of research, as the salary structure in it for the year 2019 was analyzed by relying on a number of statistical tools in the analysis process, including the arithmetic circles, upper limits, minimum limits and percentage, and with

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Mar 06 2011
Journal Name
Baghdad Science Journal
The effect of Bacillus thuringiensis in Phthorimaea operculella (Zeller) (Lepetoptera:Gelechiidae)
...Show More Authors

The following dilutions -710X46, -610X46, -510X46 of Bacillus thuringiensis were used for bioassay against the different larval instar of the potato tuber moth Phthorimaea operculella by the spraying method, the results showed that there was no significant influence in the percentage of egg hatching in comparison with the control. The sensitivity of larval stages was reduced with the increasing the age and exposure period. The study also showed that the larvae infected with B.t. stopped feeding, movement and a general paralysis causing the death of larva after (24-48) hours , and the larva color was changed from the natural waxy colour to brown finally to the black after death.

View Publication Preview PDF
Crossref
Publication Date
Wed Oct 02 2013
Journal Name
Journal Of Biology, Agriculture And Healthcare
The Prevalence of Aerobic Bacteria Isolated from Horses Fecal Samples
...Show More Authors

Dietary components and changes cause shifts in the gastrointestinal microbial ecology that can play a role in animal health and a wide range of diseases. However, most information about the microbial populations in the gut of horses has not been quantitative. The objective of this study was to characterize the fecal bacterial and its prevalence in healthy horses and diarrheal one in a period from September 2010 to July 2013. Out of 100 Fecal samples of horses (from farms in Al-furusyia club) in Baghdad were examined for microbial differentiation founded eighty percent of the fecal samples isolated from healthy horses. The most common pathogen found were Streptococcus spp. (33.7%), Escherichia coli (20.9%), , and Staphylococcus aureus (9.2

... Show More
Publication Date
Sun Dec 01 2024
Journal Name
Anbar Journal Of Agricultural Sciences
IMPROVING THE QUALITY OF POTATO MINI TUBERS BY SUSTAINABLE CULTIVATION
...Show More Authors

View Publication
Scopus (4)
Scopus Crossref
Publication Date
Tue Aug 30 2022
Journal Name
Acta Scientiarum Polonorum Administratio Locorum
Cities' urban resilience in the face of urban sprawl challenges
...Show More Authors

Motives: The research deals with the issue of urban sprawl on agricultural lands. It is an urban problem caused by rapid urbanization and poor planning. It is considered one problem that threatens cities with environmental and health disasters. It also threatens agricultural life and the green belt surrounding cities. Changes in urban sprawl on agricultural land are associated with complex processes that lead to multiple social, economic, political, and environmental risks and thus pose a threat and an obstacle to the sustainability of cities. Aim: The research aims to study and evaluate the reality of the city of Baghdad and the extent of its ability and flexibility to withstand the disaster of urban sprawl on agricultural lands. T

... Show More
View Publication
Scopus (9)
Crossref (3)
Scopus Crossref
Publication Date
Sat Jan 11 2020
Journal Name
Dirasat, Human And Social Sciences
The translation of sexual puns in Shakespeare’s Hamlet into Arabic
...Show More Authors

Scopus
Publication Date
Tue Jan 09 2024
Journal Name
مجلة واسط للعلوم الریاضیة
The development of judo from a historical perspective (1880-1980)
...Show More Authors

Judo has witnessed tremendous developments since its inception until the present day. It has been distinguished by its adaptation to the various challenges it has faced throughout the ages. Judo is one of the sports that have been affected by social, technological and cultural changes. These changes reflect its transformation from the traditional Japanese martial art to a global sport practiced. All over the world, therefore, studying the historical development of judo is important, as it provides valuable insights into the development of martial arts over a century, by studying the origins, principles and techniques of judo for the period (1880 - 1980), and also enables us to gain an understanding A deeper understanding of how the art form

... Show More
View Publication
Publication Date
Thu Jan 01 2015
Journal Name
Al–bahith Al–a'alami
Public confidence in the content of satellite channels during crises
...Show More Authors

Most studies combine that it is important to determine the extent of the public's trust TV for two reasons. First of knowing the impact of satellite TV audience ranges and the second determining public outlets for Information Find regard to the extent of the public's confidence in knowing the contents of the satellite during the occupation of Mosul crisis by organizing the Islamic state in Iraq and the Levant And the researcher developed a questionnaire to find out the public's confidence statement satellite contents provided by the questions related to exposandscale.

 

     The researcher audience chose the city of Baghdad to the suitabil

... Show More
View Publication Preview PDF
Crossref