1,683 research outputs found

    Probabilistic analysis of bladed turbine disks and the effect of mistuning

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    Probabilistic assessment of the maximum blade response on a mistuned rotor disk is performed using the computer code NESSUS. The uncertainties in natural frequency, excitation frequency, amplitude of excitation and damping are included to obtain the cumulative distribution function (CDF) of blade responses. Advanced mean value first order analysis is used to compute CDF. The sensitivities of different random variables are identified. Effect of the number of blades on a rotor on mistuning is evaluated. It is shown that the uncertainties associated with the forcing function parameters have significant effect on the response distribution of the bladed rotor

    Challenges of ā€œReverseā€ Aortic Arch Debranching for Repair of the Ascending Aorta by Thoracic Endovascular Aortic Repair

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    IntroductionAscending aortic pathology presents a unique challenge for treatment by thoracic endovascular aortic repair (TEVAR), because of lack of adequate endograft landing zones. This report describes a unique ā€œreverseā€ extra-anatomical aortic arch debranching procedure performed to enable TEVAR of the ascending aorta.ReportA 71-year-old male presented with a large ascending aortic pseudoaneurysm secondary to previous arch repair anastomosis. This pathology was treated by TEVAR of the ascending aorta. To create a sufficient landing zone for the endovascular stent graft, a ā€œreverseā€ extra-anatomical aortic arch debranching procedure was performed. This involved a left subclavian artery to left carotid artery bypass, left to right carotid-to-carotid bypass, ligation of proximal left common carotid artery, and embolization of the innominate artery origin.DiscussionTEVAR of the ascending aorta can be made feasible through a novel debranching procedure that creates sufficient landing zones for the endograft. This surgical approach may prove useful in patients who present with aortic arch pathology and comorbidities that prevent open surgical repair

    Preparation and Evaluation of Sulfacetamide Sodium Ocusert for Controlled Drug Delivery

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    The intent of this research was to formulate and evaluate controlled release ocusert of sulfacetamide sodium for the treatment of bacterial conjunctivitis. Ocusert is a sterile preparation having drug as dispersion or as solution in the polymeric base. Prepared Ocuserts were formulated using hydroxyl propyl methyl cellulose K-15 and Ethyl cellulose as polymers at various concentrations and combinations. Polymeric Films were prepared by mercury casting method using different ratios of polymers. Selected physiochemical properties such as thickness, weight, percentage moisture absorption, and in-vitro release and sterility studies of sulfacetamide sodium ocusert were studied and reported that prepared ocusert resolved the problems of poor bioavailability, frequent dosing and wastage of active ingredient. Keywords: Hydroxypropyl methyl cellulose K-15, ocusert, sulfacetamide sodiu

    Rapid Prediction of Moments in High-rise Composite Frames Considering Cracking and Time-effects

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    There can be a significant amount of moment redistribution in steel concrete composite frames due to cracking, creep and shrinkage in concrete. In the present study, neural network models have been developed for rapid prediction of the inelastic moments (typically for 20 years considering cracking, creep and shrinkage in concrete) in high rise composite frames. The possibility of sagging moment being developed at ends of beams due to the substantial differential shortening of adjacent columns has also been taken into account. Closed form expressions, based on the weights and biases of the trained neural networks, are proposed to predict the inelastic moments from the elastic moments (neglecting cracking and time effects). The expressions are verified for example frames of different number of spans and storeys and errors are found to be small. The expressions require computational effort that is a fraction of that required for the available methods

    Endoscopic tunneling of HeartMate II left ventricular assist device driveline

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    In vitro flowering in embryogenic cultures of Kinnow mandarin (Citrus nobilis Lour Ā“ C. deliciosa Tenora)

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    Embryogenic cultures of Kinnow mandarin (C. nobilis Lour Ɨ C. deliciosa Tenora) were raised from unfertilized ovules dissected from unopened flower buds of this plant inoculated on MS medium supplemented with 2 mg/L kinetin (KN). In vitro flowering was induced in these cultures by usingdifferent concentrations of KN and sucrose as well as subjecting these cultures to different photoperiods. Maximum percentage (31.94%) of cultures producing flowers and maximum number (5.58) of flowers per culture was observed on MS medium supplemented with KN (2 mg/L) and sucrose40 g/L at 12-h photoperiod

    Physical Activity during Pregnancy may Mitigate Adverse Outcomes Resulting from COVID-19 and Distancing Regulations: Perspectives of Prenatal Healthcare Providers in the Southern Region of the United States

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    International Journal of Exercise Science 14(3): 1138-1150, 2021. Prenatal physical activity (PA) may mitigate adverse outcomes that have increased as a result of the coronavirus pandemic, including poor maternal mental health. This study explored the perspectives of prenatal healthcare providers (PHCP) on maternal PA during the pandemic and identified resources providers would like to have to inform clinical discussions and prescription of PA. Semi-structured interviews were completed with PHCPs following a qualitative description approach. A content analysis coded data to inform three study objectives: 1. Changes to maternal health, 2. The role prenatal PA can have during a pandemic, 3. Resources PHCPs would find helpful to discuss and prescribe PA. Nine PHCPs completed interviews. Changes to maternal health include an increase in stress, fear surrounding labor and delivery, and risk of pre-existing problematic behaviors (e.g., substance abuse). PA was identified as helpful for improving mental health and preventing excessive gestational weight gain (EGWG). Providers expressed interest in having low cost referral options for prenatal PA that are accessible from home. PHCPs suggest PA during the pandemic can improve maternal mental health and prevent EGWG. To support clinical discussions and prescriptions of prenatal PA, knowledge translation initiatives should include informing PHCPs of referral resources for low cost at-home fitness options

    In vitro micrografting for production of Indian citrus ringspot virus (ICRSV)-free plants of kinnow mandarin (Citrus nobilis Lour X C. deliciosa Tenora)

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    Production of Indian citrus ringspot virus (ICRSV)-free plants from an infected plant of kinnow mandarin (Citrus nobilis Lour 9 C. deliciosa Tenora) is reported. The shoot apices of different sizes (0.2-1.0 mm) excised from the ICRSV-infected plant were micrografted onto decapitated rootstock seedlings of rough lemon (C. jambhiri). Micrograft survival depended on the size of shoot apex and the sucrose concentration of the culture medium. Increase in scion size from 0.2 to 0.7 mm resulted in an increase in micrografting success rate from 30.55 to 51.88%. Further, micrograft survival obtained with 0.2 mm was improved from 30.55 to 38.88% by increasing sucrose concentration in the culture media from 5 to 7.5%. The micrografted plants were tested for ICRSV using ELISA and RT-PCR. All plants raised from 0.2-mm scion were found negative with both ELISA and RT-PCR whereas only 20% of the ELISA negative plants raised from 0.3-mm scion were found negative for ICRSV with RT-PCR. The outcome of this research is the successful establishment, acclimatization and virus testing of micrografted plants
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