One of the most important phenomenon that occurs in sheet metal forming processes is the spring-back, which causes several geometrical alterations in the parts. The accurate prediction of springback after bending unloading is the key to the tool design, operation control, and precision estimate concerning the part geometry. This study investigated experimentally the effect of pretension in three rolling direction (0, 90, 45 degree) on the springback behavior of the yellow brass, sheet under V shape bending die. The pre-tension ranges from five different levels starting of 11% to 55% from the total strain in each rolling direction by regular increase of 11 %, then bent on a V-die 90 degree for the springback estimate. From experiment the results revealat that the springback increment with increase pretension ratio and the springback in 45° rolling direction is considerable than the sbringback in 90° rolling direction and the springback in 90° is greater than the sbringback in 0° rolling direction.
The aim of this research to study.
The dimensions of organizational learning have been defined(learning dynamics, individuals empowerment, knowledge management and technology application) as well as the dimensions of learning organization have been defined (culture values, knowledge transfer, communication and employee characteristics), Asset completion questionnaire was used to collect data of this research from a purposely sample represent forty employees who works in Iraqi Planning Ministry at different positions. The research divided to four parts :
The first to the research methodology, the second to the theoretical review o
... Show MoreLight is an important factor that influences the growth and photosynthetic efficiency of microalgae; however, little is known about how light intensity together with the wavelength affect the photosynthetic capacity and growth of marine microalgae. In the present study, the growth of the marine green microalga Dunaliella parva was studied and optimized under different light intensities (25 ~ 70 μmol m-2 s-1) and qualities (blue, green, and red) in comparison with white light at 40 μmol m-2 s-1 as a control. The growth was monitored by counting the cell number, pigment content, Chl a, Chl b, and carotenoids concentrations. The optimal growth and highest photosyntheti
... Show MoreThe research dealt with the case stock repurchase policy of Emaar Real Estate Company one of listed companies in Dubai Stock exchange. The research has launched from the cognitive dimensions of repurchasing policy which took great concern in the literatures of financial management, and also this policy became as substitute for distributing the monitory profit in the last three decades in the international financial markets, but it did not get any importance in the Arab Markets such as that of the Arab Gulf in addition to the Iraqi Stock Exchange.
The research summarized a set of conclusions, the most important one was the consistence of analysis result with the test of the major two hypotheses (The first
... Show MoreThe banking industry, as a result of the great challenges it faced, required continuous development of the principles of management, control and mechanisms used. The Basel Committee on Banking Supervision has played a leading role in legalizing many of these developments and has been able to contribute significantly to establishing a common framework for banking supervision, The central role in the various countries of the world is based on coordination between the various regulatory authorities and thinking about finding mechanisms to confront the risks faced by banks, recognizing the importance of the banking sector in the stability of domestic and international banking systems or the danger of this sector in the emergence of F
... Show MoreThe study aims (objective ) to clarify the concept of comprehensive income and its usefulness for users, as the study aims to clarify the relationship between the concept of comprehensive income and market value of the company where the measurement of comprehensive income after accounting for net income and by measuring the unrealized gains or losses in the value of securities available for sale, and measurement the unrealized gains or losses on futures contracts, which are financial derivatives, and measurement the unrealized gains or losses from the settlement of foreign currency translation (conversions), and measurement the impact on the market value of companies and of the present study to rise or fall of return on the stock
... Show MoreInformation and Communication Technology revolution has led to the emergence of electronic payment systems and their means And that the replacement of these modern means replace the traditional means (legal money) issued by the Central Bank has influenced the performance of monetary policy, especially that monetary policy is one of the most important policies used to achieve economic stability , The aim of the research is To know the impact of electronic payment systems on the tools of monetary policy as these means, such as cards and electronic money issued by credit institutions and companies, that is, the Central Bank is not responsible for issuance and spread And the lack of regulation by the Central Bank will lea
... Show MoreCadmium sulphide CdS films with 200 nm have been prepared by thermal evaporation technique on glass substrate at substrate room temperature under vacuum of 10-5mbar.In this paper, the effect of Dielectric Barrier Discharge plasma on the optical properties of the CdS film. The prepared films were exposed to different time intervals (0, 3, 5, 8) min. For every sample, the Absorption A, absorption coefficient α , energy gap Eg ,extinction coefficient K and dielectric constant ε were studied. It is found that the energy gap were decreased with exposure time, and absorption , Absorption coefficient, refractive index, extinction coefficient, dielectric constant increased with time of exposure to the plasma. Our study conside
... Show MoreAbstract An experiment was conducted to study the effect of Glomus mosseae and two concentration (21 and 42%) of super phosphate. They used either to be separated or together with inoculation of G. mosseae on physiological characters of Horeum Vulagera . The results showed that all treatment affected significantly especially super phosphate at the above concentration together with G. mosseae. The effects appeared as an increase in plant height , leaves area , dry weight of total plant , stem dry weight , leaves dry weight , tiller’s number , flag leaf area , dry weight of flag and also increased in CGR , RGR , RGR- NAR , LAI . The yield component increased in number of spikes, number of spikelet’s / spike, number of grain / spike, weigh
... Show MoreProfiles of indignation and indiscretion in pre-Islamic poetry
Ceramics type Yttrium oxide with Silicon carbide. were selected to investigate its sintered density, microstructure and electrical properties, after adding V2O5, of 100 nm grain size. Different weight percentages ranging from (0.01,0.02,0.03 and 0.04) were used. Dry milling applied for twelve hours. The pelletized samples were sintered at atmospheric of static air and at sintering temperature 1400 ˚C, for three hours. The crustal structure test shoes the phase which is yttrium silicon carbide Scanning electron microscopy, scan sintered microstructure. Samples after sintering were electrically investigated by measuring its capacitance, dielectric constant and their results showed increasing after added V2O5 particles at the combinat
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