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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.
81

Porovnání vertikálního výskoku u hráček volejbalu / Vertical jump comparison of women's volleyball players

Klasová, Kateřina January 2013 (has links)
Title: Vertical jump comparison of women's volleyball players Objectives: The aim of this work was to coparison of vertical jump, postural stability and body composition of women's volleyball players before and after season 2012/2013. During the season there was a deliberate intervention to develop explosive power. By the comparing the input and output of results we conclude that the training developed or didn't develop explosive power of the lower limbs, and that had an effect on body composition and stability. Methods: The study included 10 women from 2. Volleyball League (n=10 , age = ± 20,6 years, height = ± 172,7 cm, BMI = ± 0,19 kg/cm2 ). For input and output testing, we used three different tests. First, we measured body composition, then postural stability (1) narrow standing with eyes open (the US-OO), (2) narrow standing with eyes closed (the US-ZO), (3) standing on the right lower limb "flamingo test "(the FLA-R), (4) stands on the left lower limb (the FLA-L). Finally, the players performed six types of vertical jump. Jump with the upper limbs (V1 - Countermovement jump free arms) jump without the help of the upper limbs (V2 - Countermovement jump), jump from squatting (V3 - Squat jump), when the whole movement only made up, without countermovement, block jump (V4 - Block), moving one...
82

SMALL-SCALE CHARACTERIZATION OF SHOCK SENSITIVITY FOR VARIOUS NON-IDEAL EXPLOSIVES BASED ON DETONATION FAILURE BEHAVIOR

Dakota G Scott (7042820), Steven F. Son (1605886) 15 August 2019 (has links)
<pre>The plethora of potential homemade explosive (HME) formulations combined with the fact they often exhibit large critical diameters make them expensive to characterize with traditional large-scale tests. A relatively new method for small-scale characterization was investigated using non-ideal explosive charges consisting of ammonium nitrate (AN) and various fuels. This optical characterization technique utilizes the rate of reaction wave velocity decay in the failing detonations of sub-critical diameter charges as a metric for the shock sensitivity of an explosive. The conditions for detonation initiation and failure have long been used to investigate shock sensitivity (critical diameter, gap tests, run-to-detonation experiments); however, the failure regime still remains largely unexplored. The utility of this small-scale characterization technique lies in its ability to determine the relative shock sensitivity of explosive with minimal material and tests while simultaneously providing transient velocity data for potential use in modeling efforts. In this work, high speed imaging was used and analyzed to determine rates of reaction wave velocity decay in the AN-fuel samples. Among the fuels tested with AN were diesel (ANFO), nitromethane (ANNM), and aluminum (ANAl). It was found that nitromethane was the most effective at sensitizing the AN of the systems considered. In both ANNM and ANAl, maximum shock sensitivity occurred at fuel percentages below stoichiometric mixtures. This was speculated to be due to the competing effects of stoichiometry and hot spot criticality. Sensitivity results were compared to run-to-failure distances and published critical diameter trends and showed good agreement. </pre>
83

Pós-humanismo na máquina anímica : visões explosivas do humano na animação japonesa / Posthumanism in the animetic machine : explosive visions of the human in japanese animation

Longo, Angela January 2017 (has links)
Nesta pesquisa procuramos investigar a animação japonesa como uma máquina para compreendermos como a copresença evolucionária de outros seres — técnicos e animais — potencializa outras compreensões sobre o humano. Com esse posicionamento, procuramos demonstrar como o humanismo, além de se constituir como um modelo filosófico, científico e civilizacional, também propôs uma visão estética sobre o humano. Para realizar uma abertura dessa herança, procuramos traçar uma genealogia do humano e dos objetos técnicos em correlação. A compreensão do anime como uma máquina parte da teoria de Thomas Lamarre, em conjunto com as teorizações de Gilbert Simondon, Félix Guattari e Gilles Deleuze. O viés da análise tem o pressuposto de que, se a construção da animação se dá por layers, ou camadas que misturam diferentes técnicas e perspectivas visuais, poderíamos dizer que elas revelam a suis generis de pensamento em ação na animação. O humano também é pensado como uma construção, assim a relação de explosão do humanismo e da implosão do antropocentrismo visa desterritorializar o humano nos seus componentes teóricos e poéticos. O surgimento da teoria pós-humanista foi inicialmente pavimentado graças à desterritorialização posta sobre o humano no pós-estruturalismo. Para aprofundar esse argumento partimos da herança em Nietzsche e Derrida até autores pós-humanistas como Donna Haraway, Cary Wolfe, Rosi Braidotti e Stefan Herbrechter. Após estabelecermos um panorama da animação de ficção científica no Japão, iremos nos debruçar na análise das animações Rebuild of Evangelion 3.0: You Can (Not) Redo (2012) dirigida por Hideaki Anno e Ghost in the Shell: Innocence (2004) dirigida por Mamoru Oshii. De uma maneira geral a pesquisa foi dividida em três seções: pós-humanismo e techno-poética, máquina anímica e visões explosivas do humano. Na primeira, procuramos evidenciar uma genealogia do humano com atenção à sua coevolução e historicidade com os objetos técnicos, estabelecendo relações entre regimes de pensamento e estese. A segunda seção diz respeito às configurações da máquina anímica, suas relações com a tradição estética japonesa e com elementos da estética humanista, tal qual a perspectiva cartesiana. Procuramos demonstrar a existência de outros modelos visuais como uma abertura da heterogênese da máquina. A terceira seção é na qual iremos analisar as visões explosivas do humano na animação japonesa através das categorias analíticas propostas por Lamarre. Nossa hipótese é demonstrar como a máquina anímica poderia permitir uma heterogênese pós-humana através da dobra comunicacional do intervalo anímico. / In this research, we seek to investigate Japanese animation as a machine to understand how the evolutionary coo presence of other beings — technical and animal — enhances new understandings about the human. With this position, we try to demonstrate how humanism, besides constituting itself as a philosophical, scientific and civilizational model, also proposed an aesthetic vision about the human. To open this inheritance, we traced the genealogy of human and technical objects in correlation. The understanding of anime as a machine starts with the theory of Thomas Lamarre, together with the theorizations of Gilbert Simondon, Felix Guattari and Gilles Deleuze. Our analysis approach has the assumption that if the construction of the animation is made of layers that mix different techniques and visual perspectives, we could say that they reveal the suis generis of thought in action in the animation. We affirm that the human is a construction, so the relation of humanism explosion and the implosion of anthropocentrism aims to deterritorialize the human in its theoretical and techno-poetic components. The emergence of post-humanist theory has a debt to the deterritorialization put on the human in the post-structuralist theory. To deepen this argument we start from the inheritance in Nietzsche and Derrida to posthumanist authors like Donna Haraway, Cary Wolfe, Rosi Braidotti and Stefan Herbrechter. After we stablished an overview of science fiction animation in Japan, we will focus our analyses with the animations Rebuild of Evangelion 3.0: You Can (Not) Redo (2012) directed by Hideaki Anno and Ghost in the Shell: Innocence (2004) directed by Mamoru Oshii. In general, the research was divided into three sections: posthumanism and techno-poetics, the animetic machine and explosive visions of the human. In the first, we try to show a genealogy of the human with attention to its coevolution and historicity with the technical objects, establishing relations between regimes of thought and aesthetic. The second section concerns the configurations of the animetic machine, its relations with the Japanese aesthetic tradition, and elements of humanistic aesthetics, such as the Cartesian perspective. We try to demonstrate the existence of other visual models as an opening of the heterogenesis of the animetic machine. The third section is where we will analyze the explosive visions of the human in Japanese animation through the analytical categories proposed by Lamarre. Our hypothesis is to demonstrate how the animetic machine could allow a post-human heterogenesis through the communication fold of the animetic interval.
84

Low threshold organic semiconductor lasers and their application as explosive sensors

Wang, Yue January 2012 (has links)
This thesis presents studies of organic semiconductor lasers, including their operation when pumped by a light-emitting diode (LED), and their application as explosive sensors. The photophysics and amplified spontaneous emission (ASE) of star-shaped oligofluorene truxene molecules were investigated. These materials exhibit high gain and low optical loss in thin-film waveguides. Low ASE thresholds were achieved with the truxene T3 and T4. Second-order distributed feedback (DFB) lasers were fabricated, with pump threshold intensities below 0.5 kW/cm² and broad tunability of the emission. DFB lasers were demonstrated with a novel polymer BBEHP-PPV, pumped by a pulsed commercial InGaN LED. The laser emission occurred at 533 nm for peak drive current above 15 A. The output beams and pulse-dynamics of the lasers were investigated for the first time, along with a 'double-threshold' phenomenon that was observed in this long-pulse pumping regime. BBEHP-PPV lasers based on various types of diffractive resonators were also fabricated by UV nanoimprint-lithography (NIL). By optimising the resonator design and the fabrication, and the pump-beam geometry, polymer laser thresholds of ~60 W/cm², the lowest recorded for NIL lasers, were demonstrated, enabling them to be pumped by pulsed commercial LEDs and custom micro-LED arrays. One promising application of organic lasers is in explosive sensing. A polymer of intrinsic microporosity (PIM-1) was used to detect nitroaromatic vapours. Rapid detection of dinitrobenzene (DNB) of low vapour pressure was achieved by monitoring the photoluminescence and laser emission during exposure. In addition, a CMOS time-resolved fluorescence lifetime microsystem with a commercial green-emitting copolymer was used as a novel, portable sensor to detect DNB vapour. An InGaN LED pumped BBEHP-PPV laser was also used as a miniature sensor to detect 10 ppb of DNB. These highly sensitive hybrid sensors could be used in humanitarian demining, complementing existing technologies leading to improvement in the detection of hazardous objects.
85

Local and global effects on navigation in small-world networks and explosive percolation. / Local and global effects on navigation in small-world networks and explosive percolation.

Saulo Davi Soares e Reis 23 November 2012 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Um nÃmero significativo de redes reais possui caracterÃsticas locais ou nÃo-locais bem definidas. NÃs estudamos como estas caracterÃsticas podem influenciar processos de navegaÃÃo e processos percolativos que venham a ocorrer nas mesmas. Primeiramente, estudamos o problema de navegaÃÃo em redes regulares com ligaÃÃes de longo alcance e sujeitas a um vÃnculo de custo. Neste caso, a rede à construÃda a partir de uma rede regular de dimensÃo d a ser melhorada por meio da adiÃÃo de ligaÃÃes de longo alcance (atalhos) com uma probabilidade $P_{ij} sim r_{ji}^{-alpha}$ , onde $r_{ij}$ à a distÃncia de Manhattan entre os sÃtios $i$ e $j$. Mostramos que a condiÃÃo de navegaÃÃo Ãtima, $alpha = d+1$, permanece Ãtima, independente da estratÃgia de navegaÃÃo utilizada, seja ela baseada em um conhecimento local ou global da estrutura da rede. Em seguida, apresentamos um processo de crescimento de agregados que fornece uma clara conexÃo entre a MecÃnica EstatÃstica no equilÃbrio e o processo percolativo nÃo-local conhecido como PercolaÃÃo Explosiva. Mostramos que dois ingredientes sÃo suficientes para obter uma transiÃÃo abrupta na fraÃÃo do sistema ocupada pelo maior agregado: (i) os tamanhos de todos os agregados devem ser mantidos aproximadamente iguais durante o processo percolativo e (ii) a inclusÃo de ligaÃÃes de fusÃo (i.e., ligaÃÃes que conectam agregados diferentes) deve dominar o processo em detrimento de ligaÃÃes redundantes (i.e., ligaÃÃes que conectam sÃtios em um mesmo agregado). Por Ãltimo, introduzimos um modelo que generaliza a regra do produto para PercolaÃÃo Explosiva que revela os efeitos da nÃo-localidade no comportamento crÃtico do processo de percolaÃÃo. Mais precisamente, pares de ligaÃÃes nÃo ocupadas sÃo escolhidos de acordo com uma probabilidade que decai em lei de potÃncia com sua distÃncia de Manhattan, e apenas a ligaÃÃo que conecta agregados para os quais o produto de seus tamanho à o menor, à ocupada. Nossos resultados para redes regulares finitas em diversas dimensÃes sugerem que, na criticalidade, o expoente da lei de potÃncia tem uma influÃncia significativa nos expoentes de escala, onde observa-se uma transiÃÃo nos expoentes da percolaÃÃo tradicional para os expoentes da percolaÃÃo explosiva (nÃo-local) em determinados casos. / A significant number of real networks have well-defined local and nonlocal features. We investigate the influence of these features in the navigation through small-world networks and in explosive percolation. First, we investigate the navigation problem in lattices with long-range connections and subject to a cost constraint. Our network is built from a regular d-dimensional lattice to be improved by adding long-range connections (shortcuts) with probability $P_{ij} sim r_{ij}^{-alpha}, where $r_{ij}$ is the Manhattan distance between nodes $i$ and $j$, and a is $alpha$ variable exponent. We find optimal transport in the system for $alpha = d+1$. Remarkably, this condition remains optimal, regardless of the strategy used for navigation being based on local or global knowledge of the network structure. Second, we present a cluster growth process that provides a clear connection between equilibrium statistical mechanics and the nonlocal explosive percolation process. We show that the following two ingredients are sufficient for obtaining an abrupt transition in the fraction of the system occupied by the largest cluster: (i) the size of all growing clusters should be kept approximately the same, and (ii) the inclusion of merging bonds (i.e., bonds connecting nodes in different clusters) should dominate with respect to the redundant bonds (i.e., bonds connecting nodes in the same cluster). Finally, we introduce a generalization of the product rule for explosive percolation that reveals the effect of nonlocality on the critical behavior of the percolation process. Precisely, pairs of unoccupied bonds are chosen according to a probability that decays as a power law of their Manhattan distance, and only that bond connecting clusters whose product of their sizes is the smallest becomes occupied. Our results for d-dimensional lattices at criticality shows that the power law exponent of the product rule has a significant influence on the finite-size scaling exponents for the spanning cluster, the conducting backbone, and the cutting bonds of the system. For all these types of clusters, we observe a clear transition from ordinary to (nonlocal) explosive percolation.
86

Neuromechanics of maximum and explosive strength across knee-joint angles

Lanza, Marcel Bahia January 2018 (has links)
The primary purpose of this thesis was to assess the effect of knee-joint angle on the neuromechanics of maximal and explosive contractions, specifically torque and neuromuscular activation, as well as the influence of isometric resistance training (RT) on these variables and thus joint angle specificity of training adaptations. It was found that electrode location had a pronounced effect on surface electromyography (sEMG) amplitude during maximum isometric voluntary contractions (MVCs) and moderate relationship between subcutaneous tissue thickness and sEMG amplitude (R2=0.31 up to 0.38) was reduced but not consistently removed by maximal M-Wave (MMAX) normalization [up to R2= 0.16 (peak-to-peak) and R2= 0.23 (Area)]. Thus, MMAX peak-to-peak was the better normalization parameter that removed the influence of electrode location and substantially reduced the influence of subcutaneous tissue thickness. Maximal torque-angle relationship presented an inverted U shape with both, agonist (measure by two different techniques) and antagonist neuromuscular activation both differing with knee-joint angle and thus, both likely contributing to the torque-angle relationship. Absolute explosive torque-angle relationship exhibited higher torques at mid-range knee joint angles in a similar manner to maximal strength, whilst the ability to explosively express the available torque (i.e. relative to maximal strength) revealed only subtle differences between joint angles. Agonist neuromuscular activation showed increases from extended to flexed positions during both maximum and explosive contractions (at all time points; ~6% to ~34%) and evoked contractile properties presented opposite patterns with twitch torque increasing (~5% to ~30%) and octet torque decreasing (~2% to ~14%) with knee flexion. Finally, after 4 weeks of RT at a 65° knee-joint angle evidence of joint angle specificity was provided from both within-group (greater gains at 3 angles than others) and between-group evidence (greater gains at 2 angles than others) for maximal strength but not for explosive strength and neuromuscular activation. In summary, this thesis demonstrated: (1) higher strength values at middle knee-joint positions than more flexed and/or extended positions during maximal and explosive contractions; (2) how agonist neuromuscular activation contributes to the beforementioned changes in strength; (3) how muscle contractile properties contribute to the explosive strength across knee-joint angles; and finally (4) that joint angle specificity has a neural basis.
87

Power Outputs among Explosive Athletes: Relationships to Maximum Strength, and Strategies for Improvement

Stone, Michael H., Stone, Margaret E. 01 May 2008 (has links)
No description available.
88

Peak Force and Rate of Force Development During Isometric Mid-Thigh Clean Pulls and Dynamic Mid-Thigh Clean Pulls Performed at Various Intensities

Kawamori, Naoki, Rossi, Steven J., Justice, Blake D., Haff, Erin E., Pistilli, Emido E., O'Bryant, Harold S., Stone, Michael H., Haff, G. Gregory 01 August 2006 (has links)
Eight male collegiate weightlifters (age: 21.2 ± 0.9 years; height: 177.6 ± 2.3 cm; and body mass: 85.1 ± 3.3 kg) participated in this study to compare isometric to dynamic force-time dependent variables. Subjects performed the isometric and dynamic mid-thigh clean pulls at 30–120% of their one repetition maximum (1RM) power clean (118.4 ± 5.5 kg) on a 61 X 121.9–cm AMTI forceplate. Variables such as peak force (PF) and peak rate of force development (PRFD) were calculated and were compared between isometric and dynamic conditions. The relationships between force-time dependent variables and vertical jump performances also were examined. The data indicate that the isometric PF had no significant correlations with the dynamic PF against light loads. On the one hand, there was a general trend toward stronger relationships between the isometric and dynamic PF as the external load increased for dynamic muscle actions. On the other hand, the isometric and dynamic PRFD had no significant correlations regardless of the external load used for dynamic testing. In addition, the isometric PF and dynamic PRFD were shown to be strongly correlated with vertical jump performances, whereas the isometric PRFD and dynamic PF had no significant correlations with vertical jump performances. In conclusion, it appears that the isometric and dynamic measures of force-time curve characteristics represent relatively specific qualities, especially when dynamic testing involves small external loads. Additionally, the results suggest that athletes who possess greater isometric maximum strength and dynamic explosive strength tend to be able to jump higher. Eight male collegiate weightlifters (age: 21.2 ± 0.9 years; height: 177.6 ± 2.3 cm; and body mass: 85.1 ± 3.3 kg) participated in this study to compare isometric to dynamic force-time dependent variables. Subjects performed the isometric and dynamic mid-thigh clean pulls at 30–120% of their one repetition maximum (1RM) power clean (118.4 ± 5.5 kg) on a 61 X 121.9–cm AMTI forceplate. Variables such as peak force (PF) and peak rate of force development (PRFD) were calculated and were compared between isometric and dynamic conditions. The relationships between force-time dependent variables and vertical jump performances also were examined. The data indicate that the isometric PF had no significant correlations with the dynamic PF against light loads. On the one hand, there was a general trend toward stronger relationships between the isometric and dynamic PF as the external load increased for dynamic muscle actions. On the other hand, the isometric and dynamic PRFD had no significant correlations regardless of the external load used for dynamic testing. In addition, the isometric PF and dynamic PRFD were shown to be strongly correlated with vertical jump performances, whereas the isometric PRFD and dynamic PF had no significant correlations with vertical jump performances. In conclusion, it appears that the isometric and dynamic measures of force-time curve characteristics represent relatively specific qualities, especially when dynamic testing involves small external loads. Additionally, the results suggest that athletes who possess greater isometric maximum strength and dynamic explosive strength tend to be able to jump higher.
89

Lower Extremity Explosive Strength Relates to Swing Velocity Performances in NCAA Division-I Softball Athletes

Carroll, K. M., Liu, C., Sato, Kimitake, Stone, Michael H. 01 February 2017 (has links)
PURPOSE: The purpose of the study was to examine the relationship between bat swing velocity and lower extremity strength and power in NCAA Division-I softball athletes. METHODS: Twenty-nine softball athletes (age = 19.8 ± 1.3 years, height = 167.9 ± 6.8 cm, mass = 76.4 ± 18.1 kg) participated in the study. Athletes were tested on unloaded and loaded (20kg) squat and countermovement jump peak force, peak power, and jump height performed on a force platform sampling at 1000Hz. During practice, athletes were tested on swing velocity using a timing gate system. Pearson-product moment zero-order correlations were calculated between bat swing velocity and lower extremity strength and power. Statistical significance was set at p≤0.05. RESULTS: Moderate to strong relationships were observed between swing velocity and peak force at all conditions: SJ 0kg (r= 0.51, p= 0.005), SJ 20kg (r= 0.50, p= 0.006), CMJ 0kg (r= 0.44, p= 0.016), CMJ 20kg (r= 0.43, p= 0.022). Additionally, relationships were observed between swing velocity and peak power at all conditions: SJ 0kg (r= 0.45, p= 0.015), SJ 20kg (r= 0.40, p= 0.031), CMJ 0kg (r= 0.53, p= 0.003), CMJ 20kg (r= 0.45, p= 0.015). No statistically significant relationships were observed between swing velocity and jump height. CONCLUSIONS: Swing velocity was related to lower extremity force and power variables. Considering the known effects of strength training on lower extremity strength and power production, these results provide background for inclusion of lower extremity strength training for the development of swing velocity in NCAA Division-I softball athletes.
90

Power Outputs among Explosive Athletes: Relationship to Maximum Strength and Strategies for Development

Stone, Michael H. 01 June 2007 (has links)
Abstract available in the Medicine & Science in Sports & Exercise.

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