Design Strategy for the Optimization Of the Impeller in an Axial Ventricle Assist Device

The objectives of this study were to create and implement a design strategy to improve the impeller design of the Left Ventricle Assist Device (LVAD) here at RIT. CFD software paired with parametric design optimization has proved as a useful tool set to improve VAD performance in a timely and cost effective manner. A design search of one design variable was conducted to test the implementation of the design strategy. Performance of a LVAD is split between three individual parameters: 1) Pressure generation, 2) Rate of Hemolysis, and 3) Risk of Thrombosis. CFD simulations provided the data necessary to assess all areas of performance to provide a basis for comparing performances of created designs versus the original impeller. The current version of the LVAD was modeled using CFD simulations and was tested for repeatability and accuracy with bench top test data serving as the basis. Data collected from the simulations was then assessed to calculate rate of hemolysis, thrombosis risk and the pressure performance of design iteration. A weighted matrix was used to create a means to compare overall performance. Iterations were created until the local optimum was found for the design parameter tested. Pressure performance raised in all designs was tested, while there were mixed results in terms of rate of hemolysis and thrombosis risk. The top performing design dropped the risk of thrombosis by 10.8%, reduced rate of hemolysis by 0.8% and increased pressure output by 17.4% when compared to the original impeller performance. Various matrix weighting schemes were applied to verify the design as the local optimal. This also served to find the most appropriate weight balance to the three performance parameters. The design strategy that was tested and implemented has proven successful by creating an optimal impeller design for the design space explored. This study has provided the basis for a more complete design search to be completed over multiple design parameters. Another area for future studies is to complete bench top testing of the optimal design iteration created. The results from the testing can be used to further improve blood damage modeling by raising the accuracy of performance assessment

Programming Dense Linear Algebra Kernels on Vectorized Architectures

The high performance computing (HPC) community is obsessed over the general matrix-matrix multiply (GEMM) routine. This obsession is not without reason. Most, if not all, Level 3 Basic Linear Algebra Subroutines (BLAS) can be written in terms of GEMM, and many of the higher level linear algebra solvers\u27 (i.e., LU, Cholesky) performance depend on GEMM\u27s performance. Getting high performance on GEMM is highly architecture dependent, and so for each new architecture that comes out, GEMM has to be programmed and tested to achieve maximal performance. Also, with emergent computer architectures featuring more vector-based and multi to many-core processors, GEMM performance becomes hinged to the utilization of these technologies. In this research, three Intel processor architectures are explored, including the new Intel MIC Architecture. Each architecture has different vector lengths and number of cores. The effort given to create three Level 3 BLAS routines (GEMM, TRSM, SYRK) is examined with respect to the architectural features as well as some parallel algorithmic nuances. This thorough examination culminates in a Cholesky (POTRF) routine which offers a legitimate test application. Lastly, four shared memory, parallel languages are explored for these routines to explore single-node supercomputing performance. These languages are OpenMP, Pthreads, Cilk and TBB. Each routine is developed in each language offering up information about which language is superior. A clear picture develops showing how these and similar routines should be written in OpenMP and exactly what architectural features chiefly impact performance

Magical Regionalism: Canadian Geography on Screen in the 1950s

Using geography and environmental history to analyze children's film in 1950s-Canada, this paper examines regionalism in a popular National Film Board of Canada series

Optimizing Sound Speed Profiling for Hydrographic Surveys

The IHO Standards for Hydrographic Surveys (S-44) requires that hydrographic surveys account for sound speed uncertainties in order to determine the Total Propagated Uncertainty. If variations in sound speed are significant, the horizontal and vertical position of a sounding can vary by as much as several meters. Refraction artefacts can be typically dealt with in post-processing. This can be time consuming and require specialized processing expertise, especially in area of significant bathymetric relief and/or environmental variations in the water column. In this paper, we examine the application of recent advances in refraction based uncertainty to the ODIM Moving Vessel Profiler (MVP) controller software in order to optimize sound speed profiling operations.Las Normas de la OHI para Levantamientos Hidrográficos (S-44) requiere que los levantamientos hidrográficos tengan en cuenta la cuenta la incertidumbre sobre la velocidad del sonido con el objeto de determinar la Incertidumbre Total Propagada. Si las variaciones en la velocidad del sonido son significativas, la posición horizontal y vertical de una sonda puede variar tanto como varios metros. Típicamente se puede considerar los elementos refractarios durante el post procesado. Esto puede tomar tiempo y requerir experiencia especializada en procesamiento, especialmente en áreas de relieve batimétrico significativo y/o variaciones ambientales en la columna de agua. En este trabajo examinamos la aplicación de recientes progresos en la determinación de las incertidumbres basado en la refracción con el software de control del Perfilador del Movimiento de la Nave ODIM (MVP) con el objeto de optimizar las operaciones de perfilar la velocidad del sonido.Les normes de l’OHI pour les levés hydrographiques (S-44) exigent que les levés hydrographiques tiennent compte des incertitudes liées à la vitesse du son afin de déterminer l’incertitude totale propagée. Si les variations de la vitesse du son sont importantes, la position horizontale et verticale d’une sonde peut subir des variations de l’ordre de plusieurs mètres. D’une manière générale, les éléments de réfraction peuvent être pris en compte dans le cadre du post-traitement. Ceci peut prendre un certain temps et requiert des compétences spécialisées dans le traitement, notamment pour un relief bathymétrique significatif et/ou pour des variations environnementales dans la colonne d’eau. Dans cet article, nous examinons l’application des dernières avancées en matière d’incertitude basée sur la réfraction, au logiciel MVP (enregistreur de profils à partir d’un navire en mouvement) d’ODIM afin d’optimiser les opérations de détermination des profils de la vitesse du son

AIAA Design, Build, Fly: Structures and Controls

For their Santa Clara University Senior Design Project, this team chose to create an unmanned aerial vehicle (UAV) with the intent of participating in the AIAA Design, Build, Fly competition. Divided into two subteams, Aerodynamics and Structures & Controls, the teams worked together to model and construct a working prototype aircraft. The Aerodynamics team focused on selecting adequate airfoil and wing dimensions for the main wing and tail through the use of aircraft design software and CFD simulations. Aiming at a cruise speed of approximately 25 m/s, the team decided that the NACA 4416 airfoil would be the most suitable, with a chord length of 0.3 m and a wingspan of 1.5 m. The Structures & Controls team focused on the integration of the chosen airfoil into a full aircraft assembly, in addition to selection of sub-components for control and propulsion. After considering a balsa wood, carbon sheet, or foam construction, a balsa wood buildup was selected as the ideal manufacturing method to meet the system requirements. Finite element models (FEM) and simulations were preformed to design and analyze the integrity and strength of such a structure under various load cases. For sub-systems a fixed tricycle landing gear set-up was selected to minimize system weight and complexity. For an expected 3.175 kg gross weight with payload, propulsion components were selected based on power requirements established by the Aerodynamics team, consisting of a 2000W 520 Kv brushless DC motor, 22.2 Volt 4,500 mAh LiPo battery, and 15x6E propeller. The control surface actuators chosen were servo motors sized by aerodynamic analysis of the control surfaces. Finally control and transmission components were taken from current inventory including: 2.4 GHz Spektrum DX8 controller and 2.4 GHz X8R receiver. The culmination of this design project resulted in a successful test flight containing a 1 kg payload

Electromagnetic evaluation of the microstructure of grade 91 tubes/pipes

This paper assesses the feasibility of transferring a laboratory-based electromagnetic (EM) sensor technique, which has already proved sensitive to significant (e.g. phase balance) or subtle (e.g. number density of fine precipitates) microstructural changes in steel, to non-destructive evaluation of the microstructure of power generation components such as tubes/pipes. It has been found that Grade 91 steels, in different conditions representative of service entry, thermally aged or ex-service, can be distinguished using laboratory-based measurement systems on small machined cylindrical samples as well as by an industry deployment EM sensor system on full-diameter tube samples. The measurements for the tube samples follow the same trend as the machined cylindrical samples. The results indicate an industrial deployable sensor system can be used for sorting service-exposed or mis-heat-treated/mis-manufactured Grade 91 steel tubes/pipes from the correctly heat treated service-entry ones

Quantitative tissue motion analysis of digitized m-mode images: Gestational differences of fetal lung

Quantitative analysis of transmitted cardiac motion in fetal lung is evaluated by applying correlation techniques to digitized M-mode images in 21 patients, subdivided into two subgroups by gestational age: (1) 25-30 weeks (11 patients), and (11) >=35 weeks (10 patients). The corresponding numbers of M-mode images analyzed for each group are 23 and 18, respectively. This partition is expected to reflect functionally "immature" and "mature" lungs. The estimated maximum mean radial deformation per unit epicardial excursion, r I = 0.79 +/- 0.11 (sem) and r II = 0.62 +/- 0.13 (sem). The analysis presented, albeit in a limited population, is indicative of a trend in accordance with qualitative observations of Birnholz and Farrell (1985). M-mode analysis, as indicated by Adler et al. (1989) is a potentially useful technique to quantify such tissue motion.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28898/1/0000735.pd