121 research outputs found

    Computer-aided analysis and design of the shape rolling process for producing turbine engine airfoils

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    Mild steel (AISI 1018) was selected as model cold-rolling material and Ti-6Al-4V and INCONEL 718 were selected as typical hot-rolling and cold-rolling alloys, respectively. The flow stress and workability of these alloys were characterized and friction factor at the roll/workpiece interface was determined at their respective working conditions by conducting ring tests. Computer-aided mathematical models for predicting metal flow and stresses, and for simulating the shape-rolling process were developed. These models utilize the upper-bound and the slab methods of analysis, and are capable of predicting the lateral spread, roll-separating force, roll torque and local stresses, strains and strain rates. This computer-aided design (CAD) system is also capable of simulating the actual rolling process and thereby designing roll-pass schedule in rolling of an airfoil or similar shape. The predictions from the CAD system were verified with respect to cold rolling of mild steel plates. The system is being applied to cold and hot isothermal rolling of an airfoil shape, and will be verified with respect to laboratory experiments under controlled conditions

    Computer-aided analysis and design of the shape rolling process for producing turbine engine airfoils

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    Mild steel (AISI 1018) was selected as model cold rolling material and Ti-6A1-4V and Inconel 718 were selected as typical hot rolling and cold rolling alloys, respectively. The flow stress and workability of these alloys were characterized and friction factor at the roll/workpiece interface was determined at their respective working conditions by conducting ring tests. Computer-aided mathematical models for predicting metal flow and stresses, and for simulating the shape rolling process were developed. These models utilized the upper bound and the slab methods of analysis, and were capable of predicting the lateral spread, roll separating force, roll torque, and local stresses, strains and strain rates. This computer-aided design system was also capable of simulating the actual rolling process, and thereby designing the roll pass schedule in rolling of an airfoil or a similar shape

    FORMULATION AND EVALUATION OF OINTMENT CONTAINING SUNFLOWER WAX

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    Objective: The objective of the present work was to formulate and evaluate ointment using sunflower wax. Methods: In the present work, ointment formulations were prepared using sunflower wax by fusion technique. Sunflower wax base was compared with standard base for its pH, appearance, strength, spreadability, water number, and washability. Further, the optimized formulation was prepared with 2% salicylic acid and evaluated for its physicochemical parameters, compatibility study, drug content, in vitro drug diffusion, ex vivo permeability, and skin irritation test using rat skin. Results: All of the prepared formulations of ointments were evaluated for its physicochemical parameters and all the findings obtained were within the prescribed limit. As compared to the ointment prepared by prototype formulae as per USP and IP, the formulation F3 containing 97% white petrolatum and 3% of sunflower wax showed good viscosity, strength, and spreadability. Based on viscosity, strength, and spreadability, formulation F3 was chosen as an optimized formulation. Conclusion: The ointment consisting of white petroleum base 97% and 3% sunflower wax can be used for topical and systemic delivery of active ingredient salicylic acid. The results showed that sunflower wax can be used in ointment base as far as its pharmaceutical properties are concerned. It can effectively replace comparatively costlier available ointment bases

    FORMULATION AND EVALUATION OF MOISTURIZING CREAM CONTAINING SUNFLOWER WAX

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    Objective: The main objective of the present investigation was to design, prepare and evaluate moisturizing cream using sunflower wax.Methods: In the present work 32 full factorial design was applied to study the effect of varying concentration of independent variables stearic acid (X1) and sunflower wax (X2) on dependent variables viscosity and spreadability. All of the prepared formulations of moisturizing cream were evaluated for its physicochemical parameters. Further, the optimized formulation and selected commercial moisturizer compared and evaluated for its physicochemical parameters like pH, particle size, spreadability, viscosity and in vitro occlusivity test.Results: Nine different formulations of the moisturizing cream were prepared and all the findings obtained were within the prescribed limit. When compared to the prototype formulation of cream, the formulation MF5 showed good viscosity, in vitro occlusivity and spreadability. From the nine different formulations, MF5 containing 2 % stearic acid and 2 % sunflower was chosen as the optimized formula. Optimization was done on the basis of in vitro occlusivity studies and physicochemical parameters.Conclusion: The results obtained in this research work clearly showed a promising potential of moisturizing cream containing a specific ratio of stearic acid and sunflower wax as emulsifiers. Thus it can be concluded that sunflower wax is incorporated in the moisturizing cream, to avail of its cosmetic benefits

    A novel dietary supplement containing multiple phytochemicals and vitamins elevates hepatorenal and cardiac antioxidant enzymes in the absence of significant serum chemistry and genomic changes

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    A novel dietary supplement composed of three well-known phytochemicals, namely, Salvia officinalis (sage) extract, Camellia sinensis (oolong tea) extract, and Paullinia cupana (guarana) extract, and two prominent vitamins (thiamine and niacin) was designed to provide nutritional support by enhancing metabolism and maintaining healthy weight and energy. The present study evaluated the safety of this dietary supplement (STG; S, sage; T, tea; G, guarana) and assessed changes in target organ antioxidant enzymes (liver, kidneys and heart), serum chemistry profiles and organ histopathology in Fisher 344 rats. Adult male and female Fisher 344 rats were fed control (no STG) or STG containing (1X and 7X, 1X = daily human dose) diets and sacrificed after 2 and 4 months. Serum chemistry analysis and histopathological examination of three vital target organs disclosed no adverse influence on protein, lipid and carbohydrate profiles, genomic integrity of the liver and/or the tissue architecture. However, analysis of the most important antioxidant components in the liver, kidney and heart homogenates revealed a dramatic increase in total glutathione concentrations, glutathione peroxidase and superoxide dismutase enzyme activities. Concomitantly, oxidative stress levels (malondialdehyde accumulation) in these three organs were less than control. Organ specific serum markers (ALT/AST for the liver; CPK/AST/LDH for the heart; BUN/creatinine for kidneys) and the genomic integrity disclosed no STG-induced alteration. Some of the serum components (lipid and protein) showed insignificant changes. Overall, STG-exposed rats were more active, and the results suggest that STG exposure produces normal serum chemistry coupled with elevated antioxidant capacity in rats fed up to seven times the normal human dose and does not adversely influence any of the vital target organs. Additionally, this study reiterates the potential benefits of exposure to a pharmacologically relevant combination of phytochemicals compared to a single phytochemical entity

    A literature review on surgery for cervical vagal schwannomas

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    Cervical vagal schwannoma is a benign, slow-growing mass, often asymptomatic, with a very low lifetime risk of malignant transformation in general population, but diagnosis is still a challenge. Surgical resection is the treatment of choice even if its close relationship with nerve fibres, from which it arises, threats vagal nerve preservation. We present a case report and a systematic review of literature. All studies on surgical resection of cervical vagal schwannoma have been reviewed. Papers matching the inclusion criteria (topic on surgical removal of cervical vagal schwannoma, English language, full text available) were selected. Fifty-three patients with vagal neck schwannoma submitted to surgery were identified among 22 studies selected. Female/male ratio was 1.5 and median age 44 years. Median diameter was 5 cm (range 2 to 10). Most schwannoma were asymptomatic (68.2%) and received an intracapsular excision (64.9%). Postoperative symptoms were reported in 22.6% of patients. Cervical vagal schwannoma is a benign pathology requiring surgical excision, but frequently postoperative complications can affect patients lifelong, so, surgical indications should be based carefully on the balance between risks and benefits

    Loss of heterozygosity at 7p in Wilms' tumour development

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    Chromosome 7p alterations have been implicated in the development of Wilms' tumour (WT) by previous studies of tumour cytogenetics, and by our analysis of a constitutional translocation (t(1;7)(q42;p15)) in a child with WT and radial aplasia. We therefore used polymorphic microsatellite markers on 7p for a loss of heterozygosity (LOH) study, and found LOH in seven out of 77 informative WTs (9%). The common region of LOH was 7p15–7p22, which contains the region disrupted by the t(1;7) breakpoint. Four WTs with 7p LOH had other genetic changes; a germline WT1 mutation with 11p LOH, LOH at 11p, LOH at 16q, and loss of imprinting of IGF2. Analysis of three tumour-associated lesions from 7p LOH cases revealed a cystic nephroma-like area also having 7p LOH. However, a nephrogenic rest and a contralateral WT from the two other cases showed no 7p LOH. No particular clinical phenotype was associated with the WTs which showed 7p LOH. The frequency and pattern of 7p LOH demonstrated in our studies indicate the presence of a tumour suppressor gene at 7p involved in the development of Wilms' tumour. © 2000 Cancer Research Campaig
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