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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

A Study of the Validity of Brace's Basketball Achievement Tests as a Measure of Real Playing Ability of Individual Players of District 35 B University of Texas Interscholastic League for the 1950 Season

Boldin, C. T. January 1950 (has links)
The investigator made a study to determine the validity of the Brace Basketball Achievement Tests as a measure of real basketball playing ability of individual players of District 35 B of the University of Texas Interscholastic League for the 1950 season.
12

Landing Error Scoring System Evaluation of Anterior Cruciate Ligament Injury Risk with Prophylactic Ankle Support

Mosher, Marseille A. 25 August 2015 (has links)
No description available.
13

Exploring the Effect of Ankle Braces on Foot Posture

Dickerson, Laura Carroll 28 April 2020 (has links)
Foot posture is an important characteristic that can affect kinematics, plantar loading, and injury risk. Arch height is one common aspect of foot posture, and it is estimated that about 60% of the population has normal arches while 40% of the population is either pes planus or pes cavus. It is important to be able to accurately and reliably assess foot posture characteristics in order to propose interventions that could prevent injuries due to abnormal foot alignment. However, despite multiple classification metrics, many of the devices that are commonly used for foot posture measurements are not economically feasible for smaller clinics or research labs. Therefore, the first purpose of this study was to develop an affordable device to measure different foot posture characteristics. The Foot Posture Measurement System was developed and can measure total foot length, truncated foot length, foot width, dorsum height, and navicular height. This system was shown to have good to excellent validity (ICC = 0.908-0.994) and repeatability (ICC = 0.867-0.996) when compared to a 3D scanner. This device was then used in the second portion of this study, which evaluated the effects of ankle braces on plantar loading patterns in individuals with different foot postures. Contact area, peak force, force-time integral, and center of pressure were evaluated during a walk, run, and cut while the participant was unbraced, wearing a lace-up stabilizer brace, and wearing a semi-rigid brace. It was demonstrated that arch height did affect the maximum plantar forces during all tasks (p=0.001-0.047), as hypothesized based on previous studies. Additionally, this study found that ankle braces affected contact area (p=0.001-0.0014), maximum force (p<0.001 – p=0.043), and force-time integral (p<0.001 – p=0.015) during the walk, run, and cut. This is a novel finding and points to the potential for an impact of ankle braces on plantar loading during athletic activities, independent of foot type. / Master of Science / Foot posture is an important characteristic that can affect daily life and contribute to the risk of injury. Arch height is one common aspect of foot posture, and it is estimated that about 60% of the population has normal arches while 40% of the population is either high arched or low arched/flat footed. It is important to be able to accurately and reliably assess foot posture characteristics in order to propose interventions that could prevent injuries due to abnormal foot alignment. However, despite multiple classification metrics, many of the devices that are commonly used for foot posture measurements are not economically feasible for smaller clinics or research labs. Therefore, the first purpose of this study was to develop an affordable device to measure different foot posture characteristics. The Foot Posture Measurement System was developed and can measure five different length, width, and height characteristics of the foot. This system was shown to be valid when compared to a 3D scanner and repeatable between days. This device was then used in the second portion of this study, which evaluated the effects of ankle braces on individuals with different foot postures. Four different force and pressure variables were examined within the foot during a walk, run, and cut while the participant was unbraced, wearing a lace-up stabilizer brace, and wearing a semi-rigid brace. It was shown that arch height did alter plantar loading measures during all tasks, as hypothesized based on previous studies. Additionally, this study found that ankle braces affected all variables during the walk, run, and cut. This is a novel finding and points to the potential for an impact of ankle braces on plantar loading during athletic activities, independent of foot type.
14

Design comparison of ordinary concentric brace frames and special concentric brace frames for seismic lateral force resistance for low rise buildings

Grusenmeyer, Eric January 1900 (has links)
Master of Science / Department of Architectural Engineering / Kimberly Waggle Kramer / Braced frames are a common seismic lateral force resisting system used in steel structures. Ordinary concentric braced frames (OCBFs) and special concentric braced frames (SCBFs) are two major types of frames. Brace layouts vary for both OCBFs and SCBFs. This report examines the inverted-V brace layout which is one common arrangement. OCBFs are designed to remain in the elastic range during the design extreme seismic event. As a result, OCBFs have relatively few special requirements for design. SCBFs are designed to enter the inelastic range during the design extreme seismic event while remaining elastic during minor earthquakes and in resisting wind loads. To achieve this, SCBFs must meet a variety of stringent design and detailing requirements to ensure robust seismic performance characterized by high levels of ductility. The design of steel seismic force resisting systems must comply with the requirements of the American Institute of Steel Construction’s (AISC) Seismic Provisions for Structural Steel Buildings. Seismic loads are determined in accordance with the American Society of Engineers Minimum Design Loads for Buildings and Other Structures. Seismic loads are very difficult to predict as is the behavior of structures during a large seismic event. However, a properly designed and detailed steel structure can safely withstand the effects of an earthquake. This report examines a two-story office building in a region of moderately high seismic activity. The building is designed using OCBFs and SCBFs. This report presents the designs of both systems including the calculation of loads, the design of frame members, and the design and detailing of the connections. The purpose of this report is to examine the differences in design and detailing for the two braced frame systems.
15

BRACE-modellen : Ett företagsspecifikt avkastningskrav för mindre onoteradebolag / The BRACE-model : A firm-specific required rate of return for smaller, private firms

Andersson, Dag, Nilsson, Marcus January 2013 (has links)
Bakgrund: Om tio till tolv år väntas 40 % av Sveriges 500 000 familje- och ägarledda bolag att säljas enligt en uppskattning gjord av PwC år 2012. Många små och medelstora onoterade bolag kommer därför inom den närmaste tiden att behöva värderas inför försäljning. De modeller som används vid företagsvärderingar är i dagsläget inte  anpassade för mindre onoterade bolag och dess företagsspecifika risker varför författarna valde att utföra studien. Syfte: Syftet med studien är att ta fram en praktiskt användbar modell för att skatta ett mindre onoterat bolags avkastningskrav. Modellen ska ta hänsyn till de företagsspecifika risker som är kopplade till mindre onoterade bolag. Metod: Studien bygger på en kvalitativ undersökning där intervjuer med personer som dagligen arbetar med värdering av eller rådgivning för alternativt arbetar inom mindre bolag. Utifrån data insamlad från studiens intervjuer samt teorier kring ämnet har en praktiskt funktionell modell utformats för att stödja företagsvärderares arbete i praktiken. Slutsats: BRACE-modellen (Business Risk Adjusted Cost of Equity) består av två huvudkomponenter, en CAPM-premie som mäter marknadsrisken samt en företagsspecifik riskpremie. Den företagsspecifika risken hänförs till bolagets storlek och illikviditet samt kvantifieras i en poängbedömningsskala där ett mindre bolags specifika risker tas hänsyn till. / Background: In ten to twelve years, 40 % of Sweden's 500 000 family- and owner led firms will be up for sale according to an estimation done by PwC in 2012. Many small and medium sized firms will therefore need to be valued within the near future. The models and theories used in todays' business valuations are not applicable for small private firms why the authors chose to conduct this study. Purpose: The purpose of this study is to design a practically useful model in terms of assessing the owners' required rate of return in a small private firm. The model should include the firm-specific risks that are linked to private firms. Methodology: This study uses a qualitative research method where data is collected through interviews with people who on a daily basis, work with, value and advise small private firms. From the data collected through the interviews as well as theories regarding the subject the authors have designed a practical model with the intentions to support private firm valuations. Conclusion: The BRACE-model (Business Risk Adjusted Cost of Equity) consists of two main components, a CAPM-premium and a firm-specific risk premium. The firm-specific risk premium is derived from the firm's size and illiquidity and is further quantified with a point system where a small private firm's specific risks are considered.
16

Incorporating Acoustical Consistency in the Design for Manufacturing of Wooden Guitars

Dumond, Patrick January 2015 (has links)
As a musical instrument construction material, wood is both musically and aesthetically pleasing. Easy to work and abundant, it has traditionally been the material of choice. Unfortunately, wood is also a very inconsistent material. Due to great environmental and climatic variations, wooden specimens present large variations in their mechanical properties, even within species of a similar region. Surprisingly, an industry based entirely on acoustics has done very little to account for these variations. For this reason, manufactured wooden guitars are acoustically inconsistent. Previous work has shown that varying the dimensions of a guitar soundboard brace is a good method for taking into account variations in the mechanical properties of the wooden soundboard plate. In this thesis, the effects of a scalloped-shaped brace on the natural frequencies of a brace-plate system have been studied and tools have been developed in order to calculate the dimensions of the brace required to account for variations in the mechanical properties of the plate. It has been shown that scalloped braces can be used to modify two natural frequencies of a brace-plate system simultaneously. Furthermore, the most important criteria in modifying any given frequency of a brace-plate system is the mass and stiffness properties of the brace at the antinode of the given frequency’s associated modeshape. Subsequently, designing a brace for desired system natural frequencies, by taking into account the mechanical properties of the wooden plate, is an inverse eigenvalue problem. Since few methods exist for solving the inverse eigenvalue problem of general matrices, a new method based on the generalized Cayley-Hamilton theorem was proposed in the thesis. A further method, based on the determinant of the generalized eigenvalue problem was also presented. Both methods work well, although the determinant method is shown to be more efficient for partially described systems. Finally, experimental results were obtained for the natural frequencies of simply supported wooden plates, with and without a brace, as well as the inverse eigenvalue determinant method. Good correlation was found between theoretical and experimental results.
17

Evaluation of force distribution within a dual special moment-resisting and special concentric-brace frame system

Wearing, Christopher January 1900 (has links)
Master of Science / Department of Architectural Engineering and Construction Science / Kimberly W. Kramer / Dual Lateral Force Resisting Systems are currently required by code to include a Moment Resisting Frame capable of resisting at least 25% of the lateral loads. This thesis evaluates the seismic performance of a specific type of dual system: a Special Moment Resisting Frame-Special Concentric Brace Frame System (SMRF-SCBF) under three different force distributions. The three distributions were 80% - 20%, 75% - 25%, and 70% - 30% with the lesser force being allotted to the Special Moment Resisting Frame (SMRF) portion of the system. In order to evaluate the system, a parametric study was performed. The parametric study consisted of three SMRF-SCBF systems designed with different seismic force distributions. The aim of this study was to determine accuracy of the three different seismic force distributions. The accuracy was measured by comparing individual system models’ data and combined system models’ data. The data used for comparison included joint deflections (both horizontal and vertical), induced moments at moment connections, brace axial loads, column shears, and column base reactions. Two-dimensional models using the structural software RISA 3D were used to assist in designing the independent Seismic Force Resisting Systems. The designs of the frames were not finely tuned (smallest member size for strength), but were designed for drift (horizontal deflection) requirements and constructability issues. Connection designs were outside the scope of the study, except for constructability considerations – the SMRF and the SCBF did not have a common column; the frames were a bay apart connected with a link beam. The results indicated that a seismic force distribution of 75% to the SCBF and 25% to the SMRF most accurately predicts that frame’s behavior. A force distribution of 80% to the SCBF and 20% to the SMRF resulted in moderately accurate results as well. A vast opportunity for further research into this area of study exists. Alterations to the design process, consideration of wind loads, or additional force distributions are all recommended changes for further research into this topic.
18

Caracterização de fratura por fadiga em componentes mecânicos. / Characterization of fatigue failure in mechanical components.

Ihara, Larissa Mitie 03 May 2018 (has links)
Esta Dissertação, submetida à Escola Politécnica da Universidade de São Paulo, tem como objetivo a caracterização de fratura por fadiga em componentes mecânicos. Esse estudo foi motivado por dois casos de falha: barras estabilizadoras de truques de trem para transporte de minério, e engrenagens de redutores de grande porte, aplicados em turbogeradores em usinas de cogeração. Foi apresentada uma revisão da literatura sobre nucleação e propagação de trincas de fadiga, sobre fadiga de contato e por flexão de dentes, os dois principais modos de falha de engrenagens, e sobre a dinâmica do truque de trem. As amostras coletadas de barras falhadas foram caracterizadas e suas superfícies de fratura foram examinadas. A trinca de fadiga iniciou-se em uma das dobras do rebaixo, em local com dano por corrosão, que favoreceram sua nucleação. Uma análise por elementos finitos foi realizada para analisar as tensões residuais devido ao processo de dobra da barra e conformação do rebaixo e as tensões devido à operação, num caso crítico de warp tracionando a barra. Os resultados mostraram que localmente a tensão de escoamento do material foi superada, especialmente nas regiões de pequeno raio de curvatura devido ao rebaixo. Para o caso das engrenagens, foi feita uma análise de confiabilidade por distribuição de Weibull com base nos tempos de vida dos componentes falhados e do restante fabricado. Do resultado inferiu-se que as falhas consistiram na \"mortalidade infantil\" dos componentes. Havia apenas uma amostra de engrenagem falhada disponível para análise, a qual foi detalhadamente caracterizada e cuja superfície de fratura foi minuciosamente estudada, a fim de determinar o modo e o mecanismo de falha, o início da trinca e, com isso, a causa da falha. Pôde-se concluir que a engrenagem falhou devido a fadiga por flexão de dente devido a um desalinhamento na montagem. Determinadas as causas das falhas, podem-se sugerir soluções, aumentando assim a confiabilidade dos componentes. As sugestões podem dizer respeito ao próprio projeto, à seleção de materiais, aos processos de fabricação, ao tratamento térmico, à montagem, ou ao sistema de lubrificação. / This Dissertation, submitted to the Escola Politécnica da Universidade de São Paulo, aims to characterize fatigue fracture in mechanical components. This study was motivated by two cases of failure: frame brace of train bogies for ore transportation, and gears of large transmission systems, applied to turbogenerators in cogeneration power plants. A literature review was presented on nucleation and propagation of fatigue cracks, contact and tooth bending fatigue, which are the two main modes of failure of gears, and train bogie dynamics. Samples collected of failed bars were characterized and their fracture surfaces were examined. The fatigue crack initiated at one of the bends of the \"fillister\", where corrosion damage took place - both of which favoured the nucleation. A finite element analysis was performed to analyze the residual stresses due to the bending process of the bar and the forming of the \"fillister\" and the stresses due to operation, in a critical case of warp tensioning the bar. The results showed that locally the yield stress of the material was exceeded, especially in the regions of small radius of curvature due to the \"fillister\". For the case of the gears, a reliability analysis was performed by Weibull distribution based on the lifetimes of the failed components and the remainder manufactured. From the result it was inferred that the failures consisted of the \"infant mortality\" of the components. Only one failed gear sample was available for the analysis, which was thoroughly characterised and whose fracture surface was minutely studied, in order to determine the mode and mechanism of failure, crack initiation and, hence, cause of failure. It was concluded that the gear failed due to tooth bending fatigue due to misalignment in the assembly. Having determined the causes of failures, solutions can be suggested, thus increasing the reliability of the components. Suggestions may concern the design itself, materials selection, manufacturing processes, heat treatment, assembly, or lubrication system.
19

Impact of Large Gravity Loads on Buckling Restrained Braced Frame Performance

Matthews, Mark Thurgood 28 November 2009 (has links)
The Buckling Restrained Braced Frame (BRBF) is used in steel structures as a lateral load resisting system for seismic events. In typical design procedure the impact of gravity loads acting on BRBFs is neglected and the beams and columns of the structure are designed to resist all gravity loads. In actuality BRBFs are supporting portions of gravity loads acting on the structure which may be changing the overall performance of BRBFs. The purpose of this study is to determine the impact of large gravity loads on BRBF performance. This is done using finite element analysis to test two different structures supporting large gravity loads. The first structure is a seven story structure consisting of different BRBF configurations; the second structure is a three story structure with all BRBFs in an eccentrically braced configuration. Each structure was modeled with applied ground motion simulations with and without gravity loads, and with gravity loads but no applied ground motion simulations. Results indicate that gravity loads have no significant impact on the overall performance of BRBFs for either structure.
20

Heat Fluxes in Tampa Bay, Florida

Sopkin, Kristin L 08 April 2008 (has links)
The Meyers et al. (2007) Tampa Bay Model produces water level and three-dimensional current and salinity fields for Tampa Bay. It is capable of computing temperature but is presently run without active thermodynamics. Variations in water temperature are driven by heat exchange at the water-atmosphere boundary and advective heat flux at the mouth of the bay. The net heat exchange surface boundary condition is required for computations of three-dimensional temperature fields. Components of the surface heat budget were measured or derived at an observational tower in Middle Tampa Bay. Net heat exchange at the surface of Tampa Bay was computed from June 2002 to May 2005. Total heat energy gained or lost at the bay-atmosphere interface includes turbulent and radiative heat fluxes. An initial examination of turbulent heat exchange, the portion of total surface heat flux driven by atmospheric turbulence, demonstrated the skill of a bulk flux algorithm (TOGA COARE v. 3.0) in predicting measured sensible heat flux over Tampa Bay (R² = 0.80 and RMSE of 11.02 W/m² from June through November of 2002). Insolation was measured directly at the observational tower. Solar radiation is reflected in proportion to sea surface albedo, computed following Payne (1972). Based upon Secchi depth readings, Tampa Bay was classified as a water body type 7. The amount of penetrating insolation reflected from the bottom was computed for this type 7 estuary. Upwelling longwave radiation is emitted in proportion to the water temperature according to the Stefan-Boltzmann law. Eleven bulk formulas for computing downwelling longwave radiation were assessed for skill in reproducing observations made at buoys moored on the West Florida Shelf. Berliand and Berliand (1952) best represented downwelling longwave heat flux measurements at the buoys and is appropriate for application over Tampa Bay. Surface heat flux dominates cooling in fall and warming in spring while advective heat exchange becomes important during the summer. Extreme events, including tropical cyclones and extratropical fronts, dramatically impact surface heat exchange, driving rapid cooling. The methods applied in computation of heat flux components are amenable to real-time modeling exercises.

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