78 research outputs found

    Simulation of Foam Divot Weight on External Tank Utilizing Least Squares and Neural Network Methods

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    Simulation of divot weight in the insulating foam, associated with the external tank of the U.S. space shuttle, has been evaluated using least squares and neural network concepts. The simulation required models based on fundamental considerations that can be used to predict under what conditions voids form, the size of the voids, and subsequent divot ejection mechanisms. The quadratic neural networks were found to be satisfactory for the simulation of foam divot weight in various tests associated with the external tank. Both linear least squares method and the nonlinear neural network predicted identical results

    Probabilistic Simulation for Nanocomposite Characterization

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    A unique probabilistic theory is described to predict the properties of nanocomposites. The simulation is based on composite micromechanics with progressive substructuring down to a nanoscale slice of a nanofiber where all the governing equations are formulated. These equations have been programmed in a computer code. That computer code is used to simulate uniaxial strengths properties of a mononanofiber laminate. The results are presented graphically and discussed with respect to their practical significance. These results show smooth distributions

    SmaggIce Version 1.8

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    SmaggIce version 1.8 is a set of software tools for geometrical modeling of, and generation of grids that conform to, both clean and iced airfoils. Ice shapes, especially those that include rough surfaces, pose difficulty in generating high-quality grids that are essential for predicting airflows by use of computational fluid dynamics. SmaggIce version 1.8 contains software tools needed to overcome this difficulty. For a given airfoil, it allows the user to define the flow domain, decompose the domain into blocks, generate grids, merge gridded blocks, and control the density and smoothness of each grid. Among the unique features of version 1.8 is a thin C-shaped block, called a "viscous sublayer block," which is wrapped around an iced airfoil and its wake line and serves as a means to generate highly controlled grids near the rough ice surface. Users can modify block boundary shapes using control points of non-uniform rational B-spline (NURBS) curves. Concave ice regions can be smoothed during geometrical modeling or creation of the viscous sublayer block

    The development and application of autonomous, low-cost, 3D printers

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    Low-cost 3D printers have empowered individuals to create customized printed parts, but they have yet to be as user friendly as a vending machine. The purpose of this research project is to develop an autonomous, low-cost, 3D printing Vending Machine that would increase access to this technology. This research with 15 students is divided into two teams. One team is responsible for the design concepts required of an additive manufacturing vending machine and the other team is responsible for printing and prototyping the parts using a low-cost 3D printer. The teams have produced printed objects from original designs using kits they built, implemented basic communications, developed design concepts for the vending machine and training strategies to increase access. This multi-disciplinary research provides educational opportunities for students to pursue their interests in the emerging field of additive manufacturing emerging field of additive manufacturing and it addresses critical challenges in wide-spread implementation of this technology across campus

    A systematic review of Vancouver B2 and B3 periprosthetic femoral fractures

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    Aims The aim of this study was to investigate the outcomes of Vancouver type B2 and B3 fractures by performing a systematic review of the methods of surgical treatment which have been reported. Materials and Methods A systematic search was performed in Ovid MEDLINE, Embase and the Cochrane Central Register of Controlled Trials. For inclusion, studies required a minimum of ten patients with a Vancouver type B2 and/or ten patients with a Vancouver type B3 fracture, a minimum mean follow-up of two years and outcomes which were matched to the type of fracture. Studies were also required to report the rate of re-operation as an outcome measure. The protocol was registered in the PROSPERO database. Results A total of 22 studies were included based on the eligibility criteria, including 343 B2 fractures and 167 B3 fractures. The mean follow-up ranged from 32 months to 74 months. Of 343 Vancouver B2 fractures, the treatment in 298 (86.8%) involved revision arthroplasty and 45 (12.6%) were treated with internal fixation alone. A total of 37 patients (12.4%) treated with revision arthroplasty and six (13.3%) treated by internal fixation only underwent further re-operation. Of 167 Vancouver B3 fractures, the treatment in 160 (95.8%) involved revision arthroplasty and eight (4.8%) were treated with internal fixation without revision. A total of 23 patients (14.4%) treated with revision arthroplasty and two (28.6%) treated only with internal fixation required re-operation. Conclusion A significant proportion, particularly of B2 fractures, were treated without revision of the stem. These were associated with a higher rate of re-operation. The treatment of B3 fractures without revision of the stem resulted in a high rate of re-operation. This demonstrates the importance of careful evaluation and accurate characterisation of the fracture at the time of presentation to ensure the correct management. There is a need for improvement in the reporting of data in case series recording the outcome of the surgical treatment of periprosthetic fractures. We have suggested a minimum dataset to improve the quality of data in studies dealing with these fractures

    Preparing and Analyzing Iced Airfoils

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    SmaggIce version 1.2 is a computer program for preparing and analyzing iced airfoils. It includes interactive tools for (1) measuring ice-shape characteristics, (2) controlled smoothing of ice shapes, (3) curve discretization, (4) generation of artificial ice shapes, and (5) detection and correction of input errors. Measurements of ice shapes are essential for establishing relationships between characteristics of ice and effects of ice on airfoil performance. The shape-smoothing tool helps prepare ice shapes for use with already available grid-generation and computational-fluid-dynamics software for studying the aerodynamic effects of smoothed ice on airfoils. The artificial ice-shape generation tool supports parametric studies since ice-shape parameters can easily be controlled with the artificial ice. In such studies, artificial shapes generated by this program can supplement simulated ice obtained from icing research tunnels and real ice obtained from flight test under icing weather condition. SmaggIce also automatically detects geometry errors such as tangles or duplicate points in the boundary which may be introduced by digitization and provides tools to correct these. By use of interactive tools included in SmaggIce version 1.2, one can easily characterize ice shapes and prepare iced airfoils for grid generation and flow simulations

    Case report of a 27-year-old male with DCIS

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    e11635 DCIS in a young male is rarely reported. Our patient is a 25 year old male who presented with symptomatic unilateral gynecomastia. He presented with a strong family history of cancer on both maternal and paternal sides of his family including breast, lung (maternal) and melanoma, colon and pancreatic (paternal). His mother tested negative for BRCA1 and BRCA2. There is no information on the paternal genetic testing. He was treated with left subcutaneous mastectomy. Upon histologic review of the sample, concurrent gyecomastia and ductal carcinoma in situ was discovered. To date, only four cases of gynecomastia and DCIS have been described in younger male patients. Since only 30 - 50% of patients with DCIS eventually develop invasive cancer in the subsequent 10 - 20 years, this figure in the general population may be higher. This case underscores the importance of family history in any patient presenting with a breast mass. Patients must be made aware of the risk, however small it may be and physicians must remain cautious of malignancy in young males with gynecomastia. No significant financial relationships to disclose. </jats:p

    Ductal carcinoma in situ in a 25-year-old man presenting with apparent unilateral gynecomastia

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    Ductal carcinoma in situ (dcis) in a young man is rarely reported. Our patient, a 25-year-old man, presented with apparent symptomatic unilateral gynecomastia. He has a strong history of cancer on both the maternal and paternal sides of his family, including breast and lung (maternal) and melanoma, colon, and pancreatic (paternal). His mother tested negative for BRCA1 and BRCA2. There is no information on paternal genetic testing. The patient was treated with left subcutaneous mastectomy. Upon histologic review of the sample, concurrent gynecomastia and dcis were discovered. To date, only 4 cases of gynecomastia and dcis have been described in younger male patients. Because only 30%–50% of patients with dcis eventually develop invasive cancer in the subsequent 10–20 years, dcis prevalence in the general population may be higher than predicted. This case underscores the importance of family history in any patient presenting with a breast mass. Patients must be made aware of the risk, however small it may be, and physicians must remain cautious of cancer in young men with gynecomastia

    Case report of a 27-year-old male with DCIS

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