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.
A seemingly uncorrelated regression (SUR) model is a special case of multivariate models, in which the error terms in these equations are contemporaneously related. The method estimator (GLS) is efficient because it takes into account the covariance structure of errors, but it is also very sensitive to outliers. The robust SUR estimator can dealing outliers. We propose two robust methods for calculating the estimator, which are (S-Estimations, and FastSUR). We find that it significantly improved the quality of SUR model estimates. In addition, the results gave the FastSUR method superiority over the S method in dealing with outliers contained in the data set, as it has lower (MSE and RMSE) and higher (R-Squared and R-Square Adjus
... Show MoreThe aim of this research is to construct an educational program in light of the theory of behavioral cognitive and its impact on the development of the efficient response to students affected by crises (centers of your right to education). To achieve the objectives of the research, two scales were developed by the researcher in addition to two equivalent hypotheses were formulated. The scale contains (26) items divided into five fields; for its validity and reliability were derived based on the measure of efficient response, an educational program based on the theory of behavioral cognition. The test and the educational program were applied to a sample of (60) students from the centers of your right to education, divided into experimenta
... Show MoreAbstractOBJECTIVES: To evaluate the long-term remission efficacy and safety of isotretinoin in the treatment of Behcet's disease (BD). PATIENTS and METHODS: This single-blind, controlled therapeutic study was conducted in the Department of Dermatology and Venereology at Baghdad Teaching Hospital from February 2011 to January 2012. Thirty patients with BD were included in this work. Each patient received isotretinoin 20 mg orally once daily for 3 months. They were assessed at week 2 and then monthly depending on the Clinical Manifestation Index (CMI) and to record any side effects. At week 12, isotretinoin was stopped and patients were given placebo therapy in a form of glucose capsules for another 3 months. RESULTS: Thirty patients were tre
... Show MoreBackground: The posterior slope of the articular eminence of completely edentulous patients compared to patients with maintained occlusion shows significant flattening. This study aimed to correlate between the flattening of the posterior slope of the articular eminence, with dental status, age, genders, on both sides using computed tomography. Materials and Methods: The sample of the present study was a total of 117 Iraqi subjects, who admitted to the maxillofacial department at Al-Sadr Teaching Hospital in Al-Najaf city. The examination was performed on CT scanner; the eminence inclination was measured in two methods using sagittal section. Results: Clinically, the inclination of articular eminence was higher in edentulous subjects than i
... Show MoreA revision study of the Sphecidae from Iraq is presented. A survey is conducted to collect the specimens from different regions; generally, there were 41 species belonging to 12 genera and 4 subfamilies are revised with synonyms.
The current investigation included the species previously reported in Iraq, which were not collected during the current investigations; the distribution and other information are also provided.
one of the most important consequences of climate change is the rise in sea levels, which leads to the drowning of some low-lying island states, which leads to them losing the elements of statehood and thus affecting their status as a state, this resulted in several proposals made by the jurisprudence of international law to solve this issue, perhaps the most important of which is the idea of the government in exile, and the proposal to continue recognition of submerged countries, in a way that makes it possible to talk about a new concept of states represented by deterritorialized states, all of which are ultimately proposals that contain great difficulties that hinder their implementation in reality.
I've led an end to the Palestinian presence in the Jordan to the occurrence of a major fault line in relations between Jordan and the Palestinian on the levels of all , and as a result sought King Hussein and the initiative of the U.S. to heal the rift that solution between Jordanians , Palestinians, and the regulation of relations between the two parties announced in March 1972 for the project and unitary featuring Jordan and Palestine in the Arab kingdom united with the two countries , but that the Palestine Liberation Organization and the Palestinian resistance factions rejected by asserting that it is has the right of self-determination of the Palestinian people and no one else , and rejected by the Arab states and ( Israel ) , and l
... Show MoreThe species Spongilla lacustris was identified for the first time in Iraq, it was found during winter 1998 in an irrigation canal within the campus of the University of Baghdad (Jadiriah), water is drawn from Tigris river. The specimens were found in water samples of sizes ranging between 5-50 cm with yellowish color . It was found in two habitats , one as attached on submerged aquatic plant Ceratophyllum sp., and the other on the canal bottom (concret material). Some physico- chemical characters were determined including conductivity ,salinity , pH, total alkalinity, total hardness, Ca ,Mg ,anddissolved oxygen. Water quality was fresh , alkaline, hard and well aerated.
The survey and checklist of invasive species of the insects in some different localities of Iraq are revised; 24 invasive species were documented until December 2018 during the current investigations. The species distributions, common names and synonyms are given.
The current investigation included all of exotic species in Iraq, which are not collected during this study.
The study of economic growth indicators is of fundamental importance in estimating the effectiveness of economic development plans, as well as the great role it plays in determining appropriate economic policies in order to optimally use the factors that lead to the dynamics of growth in Iraq, especially during a certain period of time. The gross domestic product (GDP) at current prices), which is considered a part of the national accounts, which is considered as an integrated dynamic of statistics that produces in front of policy makers the possibility of determining whether the economy is witnessing a state of expansion or evaluating economic activity and its efficiency in order to reach the size of the overall economy. The research aims
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