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 research aims to find out the difficulties of studying the subject of modern and contemporary history and its proposed solutions from the point of view of the students of the literary sixth in the secondary schools of the Directorate of Education Rusafa I-Baghdad, the research community of students of the literary sixth stage, which Number(150) students,and to achieve the- And Fisher's equation-and percent weight).The results showed the existence of a number of real difficulties achieved for the study of modern and contemporary history of the sixth literature, and the data showed the existence of Unreal difficulties diagnosed from the students ' point of view .In light of this, the researcher dev
... Show MoreThe judge's estimation power in giving the judicial term in the execution case is represented in the possibility of amending the term of the contract commitment. That term on which both parties agreed to execute the contract commitment at its due date, because at the due date of fulfilling the commitment the debtor is bounded to pay, yet this fulfillment may be exhausting to the debtor, or causing him damage or harm more than that damage caused to the creditor in delaying the fulfillment.
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... Show MoreThe seasonal variation of two groups of Zooplankton were studied in Diyala river and two branches , about 30Km from Diyala dam It was found that there are differences in the distribution of the two groups . Atotal of six species were identified of Copepoda in Diyala river and its two branches . The species are Cyclops vernalis . C . visinus , C . dimorphus , Mesocyclops laukartu ,Paracyclops affinis and Diaptomus reighardi , where recorded high annual density in Khalis stream . Its annual density was between 0.55 – 20.66 Ind . / L. Wheras, Cladocera group 14 species were identified . and the most disturbance spe
... Show MoreBackground: The anterior loop of mental nerve is commonly described as that part of the neurovascular bundle that transverses anterior and inferior to the mental foramen only to loop back to exit the mental foramen. The aim of the study is to evaluate the incidence and extension of anterior loop of mental nerve by using digital panoramic imaging system to avoid nerve damage during different surgical procedures in dentistry. Materials and Method: Panoramic image was taken for all 400 patients and stored in the computer. Then Horizontal and Vertical for the anterior loop extension when exist was measured and recorded in a special case sheet prepared for each subject. Results: Results indicated that out of 400 patients there were only 25 pat
... Show MoreThis study was conducted to evaluate the effect of discharge of water purification plants ,on the purity of Tigris River water in Baghdad city. The two studied plants were involved in the study : Sharq –Dijla and Al-Karama water purification plants. The study was attempted to focus on probable pollutants. Chemical, physical tests were accomplished on water samples collected from four sites with fact of three replicates for each sample of each site of the river and the plant : before, after, inside the plants and at the pipe. This study started from October 2012 to September 2013. In case of heavy metals Results showed that the highest level of aluminum was 1.08 ppm during (December-January) at Sharq-Dijla plants, while the lowest level
... Show MoreTo investigate the antiplaque and antigingivitis efficacy in addition to evaluating side effects and subjects’ perceptions of three commercially available mouthwashes.
This study was a double‐blind, parallel, and short‐term trial. A total of 75 dental students with biofilm‐induced gingivitis were included in the final analysis of the current study. Clinical parameters (plaque index and bleeding on probing) and the staining effect were measured at baseline and after 7 days. In addition, a VAS‐based assessment questionnaire was completed by the participants.
With increased climate change pressures likely to influence harmful algal blooms, exposure to microcystin, a known hepatotoxin and a byproduct of cyanobacterial blooms can be a risk factor for NAFLD associated comorbidities. Using both