1,153 research outputs found

    Impact and Ricochet of a High Speed Projectile from a Plate

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    A computational study of a projectile (either 2024 aluminum or TiAl6V4 titanium alloy) impacting a plate (either titanium alloy or aluminum) is presented in this paper. Projectile velocity (ranging from 250 m/s to 1500 m/s) with varying impact angles are considered. The presence of ricochet (if any) is identified over the ranges of the projectile velocity and impact angle considered. For the cases where ricochet is identified, the ricochet angle and velocity are predicted as functions of the incident angle and the incident velocity. The numerical results are compared with an analytical solution of the ricochet problem. The analytical solutions are from a model developed to predict the ballistic ricochet of a projectile (projectile) penetrator. The dynamics and the deformation of an aluminum (or a titanium alloy) projectile impacting on a finite thickness titanium alloy (or aluminum) plate are simulated. The current work is interesting in that it looks in the field of ballistics of different material combinations than are traditionally studied. The present simulations based on detailed material models for the aluminum and the titanium alloy and the impact physics modelling features in the LS-DYNA code provide interesting details regarding the projectile/plate deformations and post-impact projectile shape and geometry. The present results indicate that for no cases (for specified incoming velocities and impact angles considered) can an aluminum projectile penetrate a titanium alloy plate. The ricochet ‘mode predictions ‘obtained from the present simulations agree well with the ricochet ‘mode predictions’ given in an analytical model

    Savings and Credit Cooperative Societies (SCCs): A Panacea to Accessing Funds for Housing Development to Workers of Public Institutions in Nigeria

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    This paper assesses the impact of Savings and Credit Cooperative Societies (SCCS) as a panacea to providing funds for housing development to workers in Nigeria public service. The Institute of Agricultural Research (IAR) Ahmadu Bello University, Zaria-Nigeria was used as a case study for the research. Questionnaires were administered to 82 staff of the institution that belongs to the institute cooperative society (IAR Rangwame Multipurpose Cooperative Society (IRMCS)) and a separate designed questionnaire was given to 3 officials of the society. Descriptive analysis, chi-square test and cooperators satisfaction index (CSI) was used for analyzing the data collected. The findings from the analysis showed that 7(8.5%) of IRMCS members have bare lands, 11(13.4%) have their houses under construction and 5(6.1%) have completed their houses while the remaining 59 members did not benefited IRMCS housing loan. The CSI on each attribute of “interest rate”, “affordability”, “transaction cost”, “availability” and “collateral” for cooperative loan are greater than 4 (close to 5) except for “availability” which is close to 4 and the aggregated CSI for all attributes is 4.17 which is also close to 5 is very high compared to National Housing Fund (NHF) CSI’s on each attributes which are all less than 2.7 with an aggregated CSI of 2.5. Also, the cooperators range of dissatisfaction index (RDI) was determined and it was found that cooperative loan had the lowest (0.832) against NHF of 2.41 and this indicates that IRMCS members are well satisfied with cooperative loans compared to the NHF. The paper concludes that SCCS can be a viable instrument in impacting positively towards funding housing projects to workers of public institutions. Keywords: SCCS, Informal sources of finance, Housing, NHF, CSI, RD

    Flow and Heat Transfer Processes in an Inertance Type Pulse Tube Refrigerator

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    Presented at the 16th International Cryocooler Conference, held May 17-20, 2008 in Atlanta, Georgia.A time-dependent axisymmetric (r-z) numerical study is reported here for the investigation of the fundamental flow and heat transfer processes found in an inertance type pulse tube refrigerator (IPTR). The general design of an IPTR incorporates a pressure wave generator, a transfer line, an aftercooler, a regenerator, a pulse tube, a pair of heat exchangers for the cold and hot ends of the pulse tube, an inertance tube and a reservoir. The performance of the IPTR system is simulated using computational fluid dynamics (CFD). The IPTR is driven by a cyclically moving piston at one end of the system operating at a fixed frequency with helium as the working fluid. Both constant temperature and convective heat transfer boundary conditions are examined along the external walls of the hot heat exchangers. The simulations reveal interesting time-dependent flow patterns that develop in the pulse tube due to the fluctuations caused by the piston and the presence of the inertance tube. The secondary-flow recirculation patterns in the pulse tube reduce the heat pumping effect from the low-temperature heat exchanger to the high-temperature heat exchangers

    Erdheim Chester Disease treated successfully with cladribine

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    AbstractA 61-year-old previously healthy male with a history of progressive fatigue, lower extremity edema, and dyspnea for 4 months was hospitalized with pericardial and pleural effusions (Figure 1A, B). Lung, pleural, and pericardial biopsies were consistent with Erdheim-Chester disease. He was treated with systemic steroids, and ultimately tried on PEG-interferon. He deteriorated clinically and the disease progressed to include CNS manifestations. Ultimately he was treated with Cladribine, at a dose 0.014 mg/kg on day 1, followed by 0.09 mg/kg/day = 6.4 mg IV for 6 additional days. He received 2 further cycles of 0.14 mg kg/day for 7 days (1 month apart). After 3 cycles he improved significantly both clinically and radiographically. Six months post-treatment objective testing showed improvement in cardiac, neurologic, and pulmonary disease.Erdheim Chester Disease (ECD) is a rare non Langerhans cell histiocytosis. Only several hundred cases have been reported in the literature. Treatment for ECD is reserved for those with symptomatic disease, asymptomatic CNS involvement, or evidence of organ dysfunction. There is no standard treatment regimen: Current options include corticosteroids, Interferon alpha (IFN), systemic chemotherapy, and radiation therapy. The occurrence of the V600EBRAF mutation in about 50% of patients can make these patients amenable to targeted therapy with BRAF kinase inhibitors (e.g. Vemurafenib). More recently the presence of N/KRAS, and PIK3CA mutations have provided further rational for targeted therapies. The cytokine profile in patients with ECD suggests monocyte activation cladribine, a purine analogue toxic to monocytes, has also been studied as a treatment for ECD, especially in patients who test negative for the BRAF mutation

    BERRY EXTRACTS IMPROVED INFLAMMATORY CYTOKINES, ANTIOXIDANT ENZYME AND SUPPRESSED THE GENE EXPRESSION ALTERATIONS IN DIABETIC RATS

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    Objective: The present work was conducted to evaluate the ameliorative effect of red berry (Morus rubra) and white berry (Morus alba) extracts in diabetic rats.Methods: Inflammatory biomarkers; tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), transforming growth factor-β (TGF-β), paraoxanase1 (PON1), gene expression of apoptosis and inflammatory related genes were carried out.Results: Treatment of male rats with streptozotocin (STZ) to induce diabetes increased the levels of TNF-α, IL-1β, TGF-β, the apoptosis rates and the alterations of the pro-apoptosis (eotaxin, caspase-1, and caspase-2) and inflammation; nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB1) and allograft inflammatory factor 1 (AIF-1) related genes. While marked reduction in PON1 level was detected in STZ-induced diabetic rats. However, treatment of STZ-exposed rats with red and white berry extracts exhibited noticeable ameliorations in TNF-α, IL-1β, TGF-β levels and PON1 activity as well as low apoptosis rates and decreased the alteration of the pro-apoptosis and inflammatory related genes.Conclusion: Red and white berry extracts exhibited attenuation in antioxidant status, suppressed inflammatory cytokines, apoptosis and the alterations in the apoptosis and inflammatory related genes induced by STZ in male rats

    Isolation of biologically active metabolites from Bougainvillea spectabilis Willd. cultivated in Egypt

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    Bougainvillea spectabilis Willd.  is an ornamental plant cultivated in tropical, subtropical regions and other places as Egypt. The present study aimed to perform bioassay guided fractionation and isolation of some of the bioactive compounds from the Egyptian cultivate. The total ethanol extracts of the leaves (T.ET.L.), stems (T.ET.S.) and flowers (T.ET.F.) were screened for some pharmacological activities viz. in vivo anti-oxidant and anti-hepatotoxic, in addition to in vitro cytotoxic activities. The anti-oxidant effect was assessed by measuring serum glutathione level (GSH) in alloxan-induced diabetic rats. The anti-hepatotoxic activity was evaluated via measuring serum markers level viz. alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) in CCl4-induced hepatotoxicity in rats. In vitro cytotoxicity of the different extracts was estimated for liver cancer cell line (HEPG2) adopting Sulforhodamine B stain assay. T.ET.L. exhibited significantly potent anti-oxidant and anti-hepatotoxic activities, while T.ET.S. showed the highest cytotoxic activity. Through biological guided fractionation, leaves and stems were subjected to successive solvent extraction, whereas the leaves ethyl acetate (Et.Ac.L.) and the stems ethanol 70% (Et.70%S.) extracts showed highly potent activities. Thus, different chromatographic techniques were performed on Et.Ac.L. and Et.70%S. extracts leading to the isolation of five bioactive metabolites. Three flavonoids were isolated from Et.Ac.L.; genistein-7-O-rutinoside (1), formononetin-7-O-rutinoside (2) and myricetin (3), while orobol-7-O-glucoside (4) and hesperidin (5) were isolated from Et.70%S. This work demonstrated the importance of the plant as a promising anti-oxidant, anti-hepatotoxic and cytotoxic product for nutraceutical use

    Greenhouse Gas Emissions from Respiratory Treatments : Results from the SABA CARBON International Study

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    Acknowledgements Medical Writing, Editorial, and Other Assistance Medical writing and editorial support were provided by Tejaswini Subbannayya, PhD, of Cactus Life Sciences (part of Cactus Communications, Mumbai, India), in accordance with Good Publication Practice (GPP3) guidelines (http://www.ismpp.org/gpp3). This support was fully funded by AstraZeneca. Funding AstraZeneca funded the study; was involved in the study design, protocol development, study conduct and statistical analysis; and was given the opportunity to review the manuscript before submission. AstraZeneca also funded medical writing support and the development of the graphical abstract. AstraZeneca funded the journal’s Rapid Service and Open Access fees.Peer reviewedPublisher PD

    Tuberculosis in Humans and Cattle in Jigawa State, Nigeria: Risk Factors Analysis

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    A cross-sectional study was conducted from September 2008 to March 2009 to identify risk factors for BTB in cattle and humans in Jigawa State, Nigeria. A total of 855 cattle belonging to 17 households were subjected to comparative intradermal tuberculin test (CITT) while interviewer-administered questionnaire was used to obtains information on the risk factors. Twenty-two (22) respondent (5%) amongst the families sampled had TB or clinical signs suggestive of TB, while 9 (2%) had reactor cattle in their herds; However, no statistically significant association (≥0.05) was observed between reactor cattle and human TB cases in the households. The habit of milk and meat consumption was found to be affected by occupation and location of the household residence. None of these risk factors (food consumption, living with livestock in the same house, and presence of BTB-positive cattle) were found to be statistically significant

    High frequency pre-slaughter electrical stunning in ruminants and poultry for halal meat production: a review

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    The use of high and low electrical frequencies in pre-slaughter electrical stunning and their implications for meat quality and animal welfare in ruminants and poultry are reviewed. There are different views regarding the appropriateness of high and low frequency stunning with respect to religious and animal welfare requirements. High electrical frequency when applied head-to-back does not initiate cardiac arrest, reduces carcass damage, enhances bleeding efficiency and eliminates the need for subsequent electrical immobilization for operator's safety. Conversely, low frequency when similarly applied kills the animal, which has animal welfare advantages, but reduces bleeding efficiency and negatively affects the quality of meat. The ability of high frequency to effectively stun without killing the stunned animal enables the process to meet this fundamental requirement for halal slaughtering when used in head-to-back in ruminants and water bath electrical stunning in poultry. Thus, it is necessary to appraise the efficacy of high and low frequency stunning in order to optimize meat quality and animal welfare attributes vis-a-vis their compliance with halal requirements
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