A principal forma de transporte de petróleo e derivados, entre outras substâncias, são os dutos, e um dos processos críticos relacionados é a sua inspeção periódica, que é necessária e obrigatória, de alto custo devido à sua complexidade, e que na maioria das vezes são realizadas manualmente, em procedimentos demorados, pouco confiáveis e insalubres devido ao meio e aos riscos a que o trabalhador é exposto. Este trabalho tem o objetivo de testar diversas aplicações e situações de um sistema de inspeção de dutos robótico desenvolvido. O interesse de observação foi a praticidade e facilidade de montagem e desmontagem do equipamento sobre a tubulação, a agilidade dos graus de liberdade propostos para o sistema, a flexibilidade do equipamento para utilização de diferentes métodos de inspeção, a rapidez e confiabilidade dos resultados de inspeção por ultrassom para varredura de espessuras em busca de corrosão generalizada interna de uma tubulação e a capacidade de precisão e resolução desta inspeção por ultrassom. Para abordar estes pontos, foram realizados uma série de testes, inicialmente para verificação do bom funcionamento dos graus de liberdade do sistema, e posteriormente com métodos diferenciados de inspeção, como testes para medição geométrica externa de uma tubulação, testes com sistemas de ultrassom embarcado em laboratório e em campo com diferentes malhas de inspeção e com um ou múltiplos cabeçotes, e para diferentes tubulações e formatos de redução de espessuras de parede na tubulação. / The main way for transporting petroleum and substances alike is through ducts, and one of the most critic processes involved is the periodic inspection, wich is necessary and mandatory, with a high cost due to its complexity, and, in most cases, done manually in long time consuming procedures and with little reliability and high risk for the workers involved. This work is intended to test various situations of a robotic inspection system developed. The observation interest was the practicity and easiness of assembling and disassembling the equipment on the pipes, the agility of degrees of freedom proposed for the system, the flexibility of the equipment for the use in different methods of inspection, the quickness and reliability of the results by ultrasound for scanning different thicknesses of a duct in search of "generalized internal corrosion" and the level of precision and resolution of this ultrasound scan. To approach this topics, a series of test were conducted, at first to check if the degrees of freedom of the system were working as intended and afterwards with different methods of inspection, such as external geometric measurements of the pipes, tests with onboard ultrasound systems in lab and on the field with different inspection grades and with one or multiple ultrasound sensors, and for different kinds of pipes and thickness reduction shapes of the pipe's walls.

O dano muscular leva a uma diminuição da função muscular. O Ultrassom Terapêutico (UST) tem mostrado promover o reparo dos tecidos, podendo ter um efeito positivo na recuperação do dano muscular. O objetivo desse estudo foi descrever os efeitos UST no dano muscular induzido pelo exercício. A amostra foi constituída de 40 sujeitos randomizados em grupo experimental (n=20) ou placebo (n=20). Os procedimentos do estudo compreenderam a avaliação da dor muscular, pico de torque isométrico (PTI), amplitude de movimento (ADM), espessura muscular, ecogenicidade, creatina cinase (CK) e interleucina 6 (IL-6) nos momentos pré, 0h, 24h, 48h, 72h e 96h após o protocolo de dano muscular nos flexores do cotovelo dominante; protocolo de indução de dano com quatro séries de10 contrações excêntricas e concêntricas no dinamômetro isocinético. O grupo experimental foi tratado com UST, com frequência de 1MHz, intensidade de pico de 0,8W/cm², intensidade média de 0,16W/cm² e razão de pulso de 1:4 no momento 0h, 24h, 48h, e 72h após o protocolo de dano muscular. O grupo placebo (n=20) recebeu aplicação do UST com todos os parâmetros zerados. Os resultados demonstram que a dor aumenta significativamente (p<0,05) após 24h e permanece elevada até 96 horas nos dois grupos (p<0,05). O PTI e ADM diminuem enquanto a espessura e a ecogenicidade muscular aumentam significativamente logo após o dano muscular e permanecem alterados até 96h (p<0,05). A concentração plasmática de CK aumentou significativamente após 72h e permaneceu elevada até 96 horas (p<0,05). A concentração plasmática de IL-6 não se alterou. Quando comparado os grupos, o grupo experimental demonstrou menor força do que o grupo placebo logo após o protocolo de dano (p<0,05). O grupo experimental apresentou uma queda menor na ADM de flexão em 96 horas comparado com o grupo placebo (p<0,05). O UST pulsado aplicado diariamente não reduz significativamente a dor, espessura muscular, ecogenicidade muscular e a creatina cinase mesmo após 96h do dano muscular. A aplicação do UST pulsado após o dano parece ter efeito negativo sobre a força muscular. No entanto, seu efeito é positivo em relação à ADM de flexão após 96h. / Muscle damage leads to a decrease of muscle function. Therapeutic Ultrasound (UST) has shown to promote tissue repair and may have a positive effect on the recovery of muscle damage. The aim of this study was to describe the UST effects on muscle damage induced by exercises. The sample consisted of 40 randomized people in the experimental (n=20) or placebo group (n=20). The study procedures understood the assessment of muscle pain, peak torque isometric (PTI), range of motion (ROM), muscle thickness, echointensity, creatine kinase (CK) and interleukin 6 (IL-6) for the pre and 0, 24, 48, 72 and 96 hours after the protocol of muscle damage in the dominant elbow flexors; damage induction protocol with four series of ten eccentric and concentric contractions on the isokinetic dynamometer. The experimental group was treated with UST with a frequency of 1MHz, peak intensity of 0.8 W/cm², average intensity of 0,16W/cm² and pulse rate of 1:4 in the 0h, 24h, 48h e 72h following the protocol of muscle damage. The placebo group received application of UST with all parameters set to zero. The results demonstrate that pain increases significantly and remains high after 24 to 96 hours in both groups (p<0.05). The PTI, ADM decrease while thickness and muscle echointensity increase significantly soon after muscle damage and remain changed to 96h (p<0.05). The plasma concentration of CK increased significantly after 72h and remained elevated up to 96 hours (p<0.05). The plasma concentration of IL-6 did not change. When comparing groups, the experimental group demonstrated lower force than the placebo group soon after the injury protocol (p<0.05). The experimental group had a smaller decrease in flexion ROM within 96 hours compared with the placebo group (p<0.05). The pulsed UST daily applied did not significantly reduce pain, muscle thickness, muscle echointensity and creatine kinase , even after 96 hours of muscle damage. The application of pulsed UST after the damage seems to have a negative effect on muscle strength. However, its effect is positive in relation to flexion ROM after 96 hours.

Este trabalho tem o objetivo de determinar as constantes elásticas de laminados compósitos de carbono/epóxi através do método não destrutivo de ultrassom, utilizando a técnica da imersão. Foram implementados dois métodos de imersão em água para a determinação das constantes elásticas. Um que utiliza o percurso na água sem a amostra como referência (FRM), e outro que utiliza o percurso com incidência normal na amostra como referência (SRM). Laminados unidirecionais e biaxiais foram ensaiados em um goniômetro com elevada precisão de movimento angular, e a aquisição de sinais feita com alta taxa de amostragem e grande resolução de amplitude. Uma análise da influência da variação da temperatura e espessura foi feita e comprovada a superioridade do método SRM sobre o FRM. A compensação da temperatura através de um par de transdutores, bem como através de um termômetro com resolução de 0.01°C foi implementada e comparada. As curvas de velocidade foram obtidas com transdutores de diferentes frequências centrais e comparadas. Foi realizada uma análise detalhada da sensibilidade das constantes elásticas com relação as velocidades em cada plano de medição, e através desta análise foram utilizados os planos mais adequados para reconstrução das constantes elásticas. Também foi verificada a polarização das ondas de cisalhamento para cada plano de medição, uma vez que é necessária a correta associação da velocidade experimental com a velocidade calculada para o procedimento de otimização. Um algoritmo de otimização foi utilizado para reconstruir as constantes elásticas dos laminados compósitos a partir da medição experimental das velocidades, onde foi avaliada a convergência utilizando a equação de Christoffel na forma implícita e explícita, para os materiais de simetria tetragonal e hexagonal. / The objective of this work is to obtain the elastic constants of carbon/epoxy composite laminates using ultrasonic non destructive testing, with immersion technique. Two immersion methods were implemented. One method uses as reference the path without sample, called fluid reference method (FRM), the second method uses the path with the specimen in normal incidence, called self-reference method (SRM). Unidirectional and biaxial laminates were tested using a goniometer with high angular resolution, and the signals were acquired with a high sample rate and amplitude resolution. Analyses of the influence of temperature and thickness variations were performed and concluded the superiority of the SRM over the FRM method. Temperature compensation using a pair of transducers and a 0.01° resolution thermometer was implemented and compared. Velocity curves were obtained and compared using transducers with different frequencies. A detailed analysis was performed to evaluate the sensitivity of the elastic constants to each velocity in different acquisition planes, and the results were used to reconstruct the elastic constants in the planes/velocities which they were most sensible to. As the correct association of each experimental velocity with the calculated velocities from Christoffel\'s equation is necessary, an analysis of the polarization mode of each velocity in the acquisition planes was also performed. An optimization algorithm was used to reconstruct the elastic constants of composite laminates from experimental velocities. Its convergence was evaluated for the implicit and explicit form of Christoffel\'s equation, and for materials with tetragonal and hexagonal symmetry.

O dano muscular leva a uma diminuição da função muscular. O Ultrassom Terapêutico (UST) tem mostrado promover o reparo dos tecidos, podendo ter um efeito positivo na recuperação do dano muscular. O objetivo desse estudo foi descrever os efeitos UST no dano muscular induzido pelo exercício. A amostra foi constituída de 40 sujeitos randomizados em grupo experimental (n=20) ou placebo (n=20). Os procedimentos do estudo compreenderam a avaliação da dor muscular, pico de torque isométrico (PTI), amplitude de movimento (ADM), espessura muscular, ecogenicidade, creatina cinase (CK) e interleucina 6 (IL-6) nos momentos pré, 0h, 24h, 48h, 72h e 96h após o protocolo de dano muscular nos flexores do cotovelo dominante; protocolo de indução de dano com quatro séries de10 contrações excêntricas e concêntricas no dinamômetro isocinético. O grupo experimental foi tratado com UST, com frequência de 1MHz, intensidade de pico de 0,8W/cm², intensidade média de 0,16W/cm² e razão de pulso de 1:4 no momento 0h, 24h, 48h, e 72h após o protocolo de dano muscular. O grupo placebo (n=20) recebeu aplicação do UST com todos os parâmetros zerados. Os resultados demonstram que a dor aumenta significativamente (p<0,05) após 24h e permanece elevada até 96 horas nos dois grupos (p<0,05). O PTI e ADM diminuem enquanto a espessura e a ecogenicidade muscular aumentam significativamente logo após o dano muscular e permanecem alterados até 96h (p<0,05). A concentração plasmática de CK aumentou significativamente após 72h e permaneceu elevada até 96 horas (p<0,05). A concentração plasmática de IL-6 não se alterou. Quando comparado os grupos, o grupo experimental demonstrou menor força do que o grupo placebo logo após o protocolo de dano (p<0,05). O grupo experimental apresentou uma queda menor na ADM de flexão em 96 horas comparado com o grupo placebo (p<0,05). O UST pulsado aplicado diariamente não reduz significativamente a dor, espessura muscular, ecogenicidade muscular e a creatina cinase mesmo após 96h do dano muscular. A aplicação do UST pulsado após o dano parece ter efeito negativo sobre a força muscular. No entanto, seu efeito é positivo em relação à ADM de flexão após 96h. / Muscle damage leads to a decrease of muscle function. Therapeutic Ultrasound (UST) has shown to promote tissue repair and may have a positive effect on the recovery of muscle damage. The aim of this study was to describe the UST effects on muscle damage induced by exercises. The sample consisted of 40 randomized people in the experimental (n=20) or placebo group (n=20). The study procedures understood the assessment of muscle pain, peak torque isometric (PTI), range of motion (ROM), muscle thickness, echointensity, creatine kinase (CK) and interleukin 6 (IL-6) for the pre and 0, 24, 48, 72 and 96 hours after the protocol of muscle damage in the dominant elbow flexors; damage induction protocol with four series of ten eccentric and concentric contractions on the isokinetic dynamometer. The experimental group was treated with UST with a frequency of 1MHz, peak intensity of 0.8 W/cm², average intensity of 0,16W/cm² and pulse rate of 1:4 in the 0h, 24h, 48h e 72h following the protocol of muscle damage. The placebo group received application of UST with all parameters set to zero. The results demonstrate that pain increases significantly and remains high after 24 to 96 hours in both groups (p<0.05). The PTI, ADM decrease while thickness and muscle echointensity increase significantly soon after muscle damage and remain changed to 96h (p<0.05). The plasma concentration of CK increased significantly after 72h and remained elevated up to 96 hours (p<0.05). The plasma concentration of IL-6 did not change. When comparing groups, the experimental group demonstrated lower force than the placebo group soon after the injury protocol (p<0.05). The experimental group had a smaller decrease in flexion ROM within 96 hours compared with the placebo group (p<0.05). The pulsed UST daily applied did not significantly reduce pain, muscle thickness, muscle echointensity and creatine kinase , even after 96 hours of muscle damage. The application of pulsed UST after the damage seems to have a negative effect on muscle strength. However, its effect is positive in relation to flexion ROM after 96 hours.

M.Tech. / The term „myofascial‟ is derived from the word „myo‟ meaning muscle and „fascia‟ meaning connective tissue. Myofascial pain syndrome is a regional pain syndrome characterized by the presence of myofascial trigger points (Mense and Simons, 2001). The most crucial component of myofascial pain is muscle shortening from contracture (or „spasm‟). In fact, myofascial pain does not exist without muscle shortening. Prolonged shortening not only causes pain in the muscle but also physically pulls on tendons, thereby straining them and distressing the bone and joints they insert into and act upon (Gunn, 2002). Trigger points are most often discussed in the setting of myofascial pain syndromes, in which widespread or regional muscular pain is associated with hyperalgesia, psychological disturbance and significant restriction of daily activities (Huguenin, 2004).

A computer controlled weld quality assurance system has been developed to detect weld defects ultrasonically whilst welding is in progress. This system, including a flash analogue to digital converter and built-in memories to store sampled data, a peak characters extractor and a welding process controller, enabled welding processes to be controlled automatically and welding defects to be detected concurrently with welding. In this way, the weld quality could be satisfactorily assured if no defect was detected and the welding cost was minimised either through avoiding similar defects to occur or by stopping the welding process if repair was necessary. This work demonstrated that the high temperature field around the weld pool was the major source of difficulties and unreliabilities in defect detection during welding and, had to be taken into account in welding control by ultrasonic means. The high temperatures not only influence ultrasonic characteristic parameters which are the defect judgement and assessment criterion, but also introduce noise into signals. The signal averaging technique and statistical analysis based on B-scan data have proved their feasibility to increase 'signal to noise ratio' effectively and to judge or assess weld defects. The hardware and the software for the system is explained in this work. By using this system, real-time 'A-scan' signals on screen display, and, A-scan, B-scan or three dimensional results can be printed on paper, or stored on disks, and, as a result, weld quality could be fully computerized.

Increasing demand for precision components made of hard and brittle materials such as glasses, steel alloys and advanced ceramics, is such that conventional grinding and polishing techniques can no longer meet the requirements of today's precision manufacturing engineering. Particularly, in order to undertake micro-milling of optical glasses or other hard-machining materials, vibration assisted machining techniques have been adopted. However, it is essential and much needed to undertake such processes based on a scientific approach, i.e. the process to be quantitatively controlled and optimized rather than carried out with a trial-and-error manner. In this research, theoretical modelling and instrumental implementation issues for vibration assisted micro-milling are presented and explored in depth. The modelling is focused on establishing the scientific relationship between the process variables such as vibration frequency, vibration amplitude, feedrate and spindle speed while taking into account machine dynamics effect and the outcomes such as surface roughness generated, tool wear and material removal rate in the process. The machine dynamics has been investigated including a static analysis, machine tool-loop stiffness, modal analysis, frequency response function, etc, carried out for both the machine structure and the piezo-actuator device. The instrumentation implementation mainly includes the design of the desktop vibration assisted machining system and its control system. The machining system consists of a piezo-driven XY stage, air bearing spindle, jig, workpiece holder, PI slideway, manual slideway and solid metal table to improve the system stability. The control system is developed using LabVIEW 7.1 programming. The control algorithms are developed based on theoretical models developed by the author. The process optimisation of vibration assisted micro-milling has been studied by using design and analysis of experiment (DOE) approach. Regression analysis, analysis of variance (ANOVA), Taguchi method and Response Surface Methodology (RSM) have been chosen to perform this study. The effects of cutting parameters are evaluated and the optimal cutting conditions are determined. The interaction of cutting parameters is established to illustrate the intrinsic relationship between cutting parameters and surface roughness, tool wear and material removal rate. The predicted results are confirmed by validation experimental cutting trials. This research project has led to the following contribution to knowledge: (1) Development of a prototype desktop vibration assisted micro-milling machine. (2) Development of theoretical models that can predict the surface finish, tool wear and material removal rate quantitatively. (3) Establishing in depth knowledge on the use of vibration assisted machining principles. (4) Optimisation of cutting process parameters and conditions through simulations and machining trials for through investigation of vibration assisted machining.

Background and aims: It is known that smooth muscle possesses substantial mechanical plasticity in that it is able to adapt to large changes in length without compromising its ability to generate force. It is believed that structural malleability of the contractile apparatus underlies this plasticity. There is strong evidence suggesting that myosin thick filaments of the muscle are relatively labile and their length in vivo is determined by the equilibrium between monomeric and filamentous myosin. The equilibrium in turn is governed by the state of phosphorylation of the 20-kD regulatory myosin light chain (MLC20, or RLC). It is known that phosphorylation of the myosin light chain favors formation of the filaments; it is not known how the light chain phosphorylation affects the lability of the filaments. The major aim of this thesis was to measure the mechanical integrity of the filaments formed from purified myosin molecules from bovine airway smooth muscle, and to determine whether the integrity was influenced by phosphorylation of the myosin light chain. Methods: Myosin was purified from bovine trachealis to form filaments, in ATP containing zero-calcium solution during a slow dialysis that gradually reduced the ionic strength. Sufficient myosin light chain kinase and phosphatase, as well as calmodulin, were retained after the myosin purification and this enabled phosphorylation of RLC within 20-40 s after addition of calcium to the filament suspension. The phosphorylated and non-phosphorylated filaments were then partially disassembled by ultrasonification. The extent of filament disintegration was visualized and quantified by atomic force microscopy. Results: RLC phosphorylation reduced the diameter of the filaments and rendered the filaments more resistant to ultrasonic agitation. Electron microscopy revealed a similar reduction in filament diameter in intact smooth muscle when the cells were activated. Conclusion: Our results suggest that RLC phosphorylation is a key regulatory step in modifying the structural properties of myosin filaments in smooth muscle, where formation and dissolution of the filaments are required in the cells’ adaptation to different cell length. / Medicine, Faculty of / Medicine, Department of / Experimental Medicine, Division of / Graduate

A thesis submitted in compliance with the requirements for the Masters Degree in Technology: Mechanical Engineering at Technikon Natal, 2002. / The experiments and their results contained herein will form the basis for the development of a portable non-destructive testing device for composite structures. This device is to be capable of detecting any of a variety of defects and assessing their severity within a short time / M

Dissertation presented in partial compliance with the requirements for a Masters Degree in Technology: Chiropractic, Technikon Natal, 1998. / Very few studies of medial tibial stress syndrome type II address the treatment of the condition. There is a need to find a method of hastening the recovery of the condition. Therefore the objective of this study was to determine whether application of ultrasound therapy to medial tibial stress syndrome type Il would influence the recovcrv of this condition. / M