1,362 research outputs found

    Evaluation of Deformable Boundary Condition Using Finite Element Method and Impact Test for Steel Tubes

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    Stainless steel pipelines are crucial components to transportation and storage in the oil and gas industry. However, the rise of random attacks and vandalism on these pipes for their valuable transport has led to more security and protection for incoming surface impacts. These surface impacts can lead to large global deformations of the pipe and place the pipe under strain, causing the eventual failure of the pipeline. Therefore, understanding how these surface impact loads affect the pipes is vital to improving the pipes’ security and protection. In this study, experimental test and finite element analysis (FEA) have been carried out on EN3B stainless steel specimens to study the impact behaviour. Low velocity impact tests at 9 m/s with 16 kg dome impactor was used to simulate for high momentum impact for localised failure. FEA models of clamped and deformable boundaries were modelled to study the effect of the boundaries on the pipes impact behaviour on its impact resistance, using experimental and FEA approach. Comparison of experimental and FE simulation shows good correlation to the deformable boundaries in order to validate the robustness of the FE model to be implemented in pipe models with complex anisotropic structure

    Modelling reinforced concrete beams for structural strengthening of buildings

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    Iraq has many damaged and vandalized building since it is located in the Middle East, in southwestern Asia. Reinforced concrete beams of normal weight and lightweight's beams were conducted. The study is also done on normal strength and high strength beams in each category. The reinforced concrete used were 0% and 0.75% in each category. The lengths of the concrete beams used were 35 mm and 60 mm in each category. The longitudinal reinforcement ratio in all the beams is kept at 1.46%. The effect of types of aggregates, length of concrete beams, and concrete compressive strength were studied and results were presented with regard to the shear and flexure strengths, beam load-deflection responses, mode of failure, stiffness, energy absorption, and ductility. Shear and flexural crack widths and cracking patterns of the beams were also presented. Reinforced concrete content of the beams was also discussed. The possibility of replacement of minimum concrete reinforcement for lightweight beams with reinforced concrete is discussed. The most efficient length of beams for this purpose was presented. The modeling of buildings were designed in ANSYS and the strengthening as well as reinforcement was being shown using the software tool for the buildings in Iraq

    Surface sampling within a pediatric ward—how multiple factors affect cleaning efficacy

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    BACKGROUND: The objectives of this study were to assess the number of organisms present on different surfaces within a clinical environment before and after cleaning took place, and to identify the impact of cleaning. The study involved extensive 2-week microbiological environmental monitoring of an entire ward before and after cleaning; the ward was located within a pediatric hematology-oncology ward comprised of a day unit and outpatient ward. METHODS: Tryptone soya agar contact plates were used to take a total of 1,160 surface samples before and after cleaning from 55 predetermined sites. Samples were taken from representative surfaces throughout the ward representing a variety of materials, surface heights, functions, and distances from patients, as well as both high-touch and infrequently touched surfaces. RESULTS: After surface cleaning was undertaken within the ward, there was a significant difference between the amount of colony-forming units (CFUs) recovered before and after cleaning (P < .0001). Cleaning produced an average CFU reduction of 68% throughout the ward environment. The corridor was the most contaminated area within the ward. There were differences in the CFUs among the various areas within the ward, which were cleaned with varying efficiency. The surface material, who interacted with the surface, levels of initial contamination, perceived risk, and perceived cleanability were all found to have a varying impact on the cleaning effectiveness. CONCLUSIONS: To the authors' current knowledge, this is the only study to assess cleaning within a pediatric ward by taking samples directly before and after cleaning. The standard of cleaning undertaken within the ward is open for discussion, and these data highlight the need for an improved cleaning intervention and can provide insight into the multitude of factors that must be considered when designing an effective training protocol

    Treatment of Iron-deficiency Anemia in Patients with Subclinical Hypothyroidism

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    Subclinical hypothyroidism is a health state that is associated with hypercholesterolemia, infertility, iron-deficiency anemia, and poor obstetric outcome. This article summarizes the results of a prospective clinical investigation of whether treatment of subclinical hypothyroidism and iron-deficiency anemia with a combination of levothyroxine plus iron salt would be superior to each treatment alone. METHODS: In a randomized, double-blind, active-controlled trial, 60 patients with subclinical hypothyroidism and iron-deficiency anemia received iron salt+placebo (20 patients), levothyroxine+placebo (20 patients), or levothyroxine+iron salt (20 patients) for 3 months. Change from baseline (before) to end of study (after) in hemoglobin, ferritin, and thyroid-stimulating hormone levels were compared among groups. RESULTS: The increase from baseline in hemoglobin and ferritin in the levothyroxine+iron group was superior to the other groups, in which a decrease in thyroid-stimulating hormone in the 2 groups that received levothyroxine was superior to the group treated with iron salt. CONCLUSION: Subclinical hypothyroidism was investigated in iron-deficient patients with no acceptable response to iron salt alone. A combination of levothyroxine and iron salt is better than each one alone
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