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.
Aromatic Schiff-bases are known to have antibacterial activity, but most of these compounds are sparingly soluble in water. The present work describes the synthesis of new Schiff-bases derived from branched aminosugars. Treatment of 3-Amino-3-Cyano-3-Deoxy-1,2:5,6-Di-O-Isopropylene-α-D-Allofuranose (1) with the aldehydes (2) under reflux in methanol afforded the Schiff-bases (3) in good yields. The new Schiff-bases were in accord with their NMR, IR spectral data and elemental analysis.
Background: The present in-vitro study was undertaken to evaluate and compare fracture resistance of weakened endodontically treated premolars with class II MOD cavities restored with different bulk fill composite restorations (EverX posterior, Alert, Tetric EvoCeram Bulk Fill, and SDR). The type and mode of fracture were also assessed for all the experimental groups. Materials and Method: Forty-eight human adult maxillary premolar teeth were selected for this study. Standardized extensive class II MOD cavities with endodontic treatment were prepared for all teeth, except those that were saved as intact control. The teeth were divided into six groups of eight teeth each (n=8): (Group 1) intact control group, (Group 2) unrestored teeth with
... Show MoreKE Sharquie, AA Al-Nuaimy, WJ Kadhum, Saudi medical journal, 2006 - Cited by 3
Objectives: This study aims to assess and compare the micro-shear bond strength (μSBS) of a novel resin-modified glass-ionomer luting cement functionalized with a methacrylate co-monomer containing a phosphoric acid group, 30 wt% 2-(methacryloxy) ethyl phosphate (2-MEP), with different substrates (dentin, enamel, zirconia, and base metal alloy). This assessment is conducted in comparison with conventional resin-modified glass ionomer cement and self-adhesive resin cement. Materials and methods: In this in vitro study, ninety-six specimens were prepared and categorized into four groups: enamel (A), dentin (B), zirconia (C), and base metal alloys (D). Enamel (E) and dentin (D) specimens were obtained from 30 human maxillary first premolars e
... Show MoreIn the current work, the mixing ratios ( 𝛿 ) of gamma transitions were calculated from energy levels in the isotopes neodymium 60𝑁𝑎 142−150 populated in the 60Nd 142− 150 (n, n ˊγ) 60Nd 142− 150 using the 𝑎2 ratio method. We used the experimental coefficient (𝑎2 ) for two γ-transitions from the initial state itself, the statistical tensor 𝜌2(𝐽𝑖), associated with factor 𝑎2 , would be the same for the two transitions. The results obtained are in good agreement or within the experimental error with -those previously published. And existing contradictions resulting from inaccuracies in the empirical results of previous work. The current results confirm that the , 𝑎2 − method is used to calculate th
... Show MoreThe present study provides a new insight into valuable information on the diverse structure of the Anisakid population and discusses the limited species richness in the Nemipterus japonicus (Bloch,1791) (Perciformes, Nemiperidae). The fishing area consists of various locations in the Arabian Gulf (29°58 0 33 00 N48°28 0 20 E). A total of 315 marine fish were examined, (n=287) were infected. Larval stages (n= 763) encysted within the mesenteries peritoneum and viscera of fish organs were isolated, with a prevalence of 91.11% of infection and, the intensity was 2.65. Molecular analysis was carried out on thirty individuals who have examined the morphology and showed some appearance differences, by amplifying internal transcribed spacers
... Show Moreيعد الكيمياء من العلوم المهمة التي تدرس في جميع مراحل التعليم الاساسي ومراحل التعليم العالي في كليات (الزراعة ، العلوم ، الصيدلة ، التربية الاساسية ، الطب ، طب الاسنان ، الطب البيطري) لأنها تدخل في الكثير من مفاصل الحياة اليومية وما لها من تأثير في تقدم المجتمعات من الناحية الصناعية والاقتصادية حيث تدخل الكيمياء في الصناعات الغذائية ، والصناعات الدوائية او صناعة الاقمشة والزراعة وتطوير الثروة الحيوانية عن ط
... Show MoreWhite and black chia seeds were used in some food products, such us gluten –free biscuits processing by using rice flour and chia seeds (white and black) with these amonths 112.5, 74.25, 56.25, 27.5 g with 27.5g of quinoa seeds for treatments 1, 2, 3 and 4 respectively, and comparison sensitively with the control treatment which has no additions including the appearance and homogenization of the product, surface cracks, softness, taste and flavor, core color and the specific volume, some microbiological tests were performed for biscuit product after storage for 4 months at 30 and 50°C including bacterial total count and fungal and yeast count, results showed that there weren’t any observation of bacteria or yeast or fungal growth at
... Show Moreيختلف دور العلاقات العامة (PR) وأهميتها من مجتمع إلى آخر، تبعاً لاختلاف ثقافات هذه المجتمعات عموماً, ولاختلاف القيم الأخلاقية المعمول بها من ممارسيها في منظمات هذه المجتمعات, فالعلاقات العامة في المجتمعات المتقدمة وبعض الدول النامية قد خطت خطوات جبارة ووصلت إلى مرحلة المساهمة في التخطيط الاستراتيجي وعملية اتخاذ القرار, في إطار التزام إداراتها بقيم ومعايير أخلاقية محددة لممارسيها, وبالمقابل نجد أن تطبيقها في
... Show MorePrayer It is the second pillar of Islam, which is what Allaah erases sins, the Prophet, peace be upon him say: "Do you see if the river at the door of you wash it every day five, what it says: it keeps dirt," they said, does not keep the dirt something, He said: «That is like the five daily prayers, Allaah erases sins", Bukhari (1/112), and the places and times supervised thanks to worship them, was to pray at the three mosques (the Grand Mosque and the Prophet's Mosque and the Al-Aqsa Mosque) private virtue from the rest of the mosques and this virtue include the obligatory prayers and Voluntary Prayers.