The advancement of technologies that interface with electrically excitable tissues, such as the cortex and muscle, has the potential to lend greater mobility to the disabled, and facilitate the study of the central and peripheral nervous systems. Myoelectric interfaces are currently limited in their signal fidelity, spatial resolution, and interfacial area. Such interfaces are either implanted in muscle or applied to the surface of the muscle or skin. Thus far, the former technology has been limited in its applications due to the stiffness (several orders of magnitude greater than muscle) of its substrates, such as silicon and polyimide, whereas the latter technology suffers from poor spatial resolution and signal quality due to the physical separation between the electrodes and the signal source. We have developed a stretchable microneedle electrode array (sMEA) that can function while stretching and flexing with muscle tissue, thereby enabling multi-site muscle stimulation and electromyography (EMG) measurement across a large interfacial area. The scope of this research encompassed: (i) the development of a stretchable and flexible array of penetrating electrodes for the purposes of stimulating and measuring the electrical activity of excitable tissue, (ii) the characterization of the electrical, mechanical, and biocompatibility properties of this electrode array, (iii) the measurement of regional electrical activity of muscle via the electrode array, (iv) the study of the effect of spatially distributed stimulation of muscle on the fatigue and ripple of muscle contractions, and (v) the assessment of the extent to which the stretch response of electrically stimulated muscle behaves in a physiological manner.

Thesis (MEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Over the last few decades, wave run up prediction has gained the interest of numerous researchers and every newly-published paper has aimed to predict wave run up with greater accuracy. Wave run up is defined as the vertical elevation reached by a wave's, front water edge as it runs up a beach, measured relative to the still water line. Wave run up is dependent on the incidental wave height, the wave period, the beach slope and the wave steepness. The majority of publications incorporate all of these factors, but some do not, which has led to numerous debates. The goal of this study is to do a re-assessment of previously published wave run up formulae, to obtain a more informed understanding about wave run up and the available predictive empirical formulae. The study also seeks to evaluate the Mather, Stretch & Garland (2011) formula. The method for undertaking this objective comprised a physical model test series with 10 regular wave conditions on a constant slope, being 1/24, performed with an impermeable floor. Also, a beach study in the field was done on Long Beach, Noordhoek, where run up measurements were taken for 30 minute intervals, resulting in five test conditions. A numerical model was employed in conjunction with the beach study to determine the local offshore wave parameters transformed from a deep water wave rider. This information was used to correlate the run up measurements with known wave parameters. Firstly, the physical model assessment was performed to provide a proper foundation for run up understanding. Plotting empirical normalised run up values (R2/H0 ) versus the Iribarren number for different formulae, a grouping was achieved with upper and lower boundaries. The physical model results plotted on the lower end of this grouping, resulted in prediction differences of more than 10%. These differences may have been caused by the unevenness of the physical model slope or the fact that only one slope had been tested. Despite this, the results fell within a band of wave run up formulae located on the lower end of this grouping. An assessment of the beach measurements in the field gave a better correlation than the physical model results when compared to normalised predicted wave run up formulae. These measurements also plotted on the lower end of the grouping, resulting in prediction differences of less than 10% for some empirical formulae. When comparing these empirical predictions to one another, the results demonstrate that the formulae comparing best with the beach measurements were Holman (1986) and Stockdon, Holman, Howd, & Sallenger Jr. (2006). Extreme over predictions were found by Mase & Iwagaki (1984), Hedges & Mase (2004) and Douglass (1992). Nielsen & Hanslow (1991) only compared best with the beach measurements and De la Pena, Sanchez Gonzalez, Diaz-Sanchez, & Martin Huescar (2012) only compared best to the physical model results. This study supports the formula proposed by Mather, Stretch, & Garland (2011). Applying their formula to the measured results presented a C constant of 3.3 for the physical model and 8.6 for the beach results. Both values are within the range prescribed by the authors. Further reasearch minimized the array of possible „C‟ values by correlating this coefficient to Iribarren numbers. „C‟ values between 3.0~5.0 is prescribed for low Iribarren conditions (0.25-0.4) and values between 7.0~10 for higher Iribarren conditions are 0.75-0.8. However, this formula is still open for operator erros whereby the „C‟ value has a big influence in the final result. The best formulae to use, from results within this thesis, is proposed by Holman (1986) and Stockdon et.al (2006). These formulae are not open to operator erros and uses the significant wave height, deep water wave length and the beach face slope to calculate the wave run up. / AFRIKAANSE OPSOMMING: Gedurende die afgelope paar dekades, het golf-oploop voorspellings die aandag van talle navorsers gelok en elke nuwe geskrewe voorlegging het gepoog om meer akkurate golf-oploop voorspellings te verwesenlik. golf-oploop kan definieer word as die vertikale elevasie bereik deur 'n golf se voorwaterkant soos dit op die strand uitrol, gemeet relatief vanaf die stilwaterlyn. golf-oploop is afhanklik van die invals-golfhoogte, die golfperiode, die strandhelling en die golfsteilheid. Die oorgrote mederheid publikasies uit die literaturr inkorporeer al hierdie faktore, maar sommige nie, wat groot debatvoering tot gevolg het. Die doel met hierdie studie is om vorige gepubliseerde golf- oploop formules te re-evalueer, om 'n meer ingeligte begrip van golf- oploop en beskikbare voorspellende formules te verkry. Die studie poog terselfdertyd ook om golf-opvolg tendense, uniek aan Suid Afrikaanse strande te evalueer deur die huidige formule wat tans hier gebruik word, te assesseer. Om hierdie doelwit te bereik, is gebruik gemaak van 'n fisiese model toets reeks bestaande uit 10 reëlmatige golfstoestande op 'n konstante ondeurlaatbaare strandhelling van 1/24. 'n Veldstudie was ook uitgevoer op Langstrand, Noordhoek, waar golf-oploopmetings met 30 minute tussenposes uitgevoer is, vir vyf toets-toestande. Tesame met die veldstudie, is 'n numeriese model aangewend om die gemete diepsee data nader ann die strand wat bestudeer is te transformeer. Hierdie inligting is benodig om 'n verband tussen tussen oploop-metings en bekende golf parameters te bepaal. Eerstens is die fisiese model assessering uitgevoer om 'n behoorlike basis vir die begrip van golfoploop in die veld te verkry. Deur die emperiese, genormaliseerde oploop waardes (R₂/H₀) vir verkeie formules teenoor die Iribarren getal te plot, is 'n groepering met hoër en laer grense gevind. Daar is gevind dat die fisiese modelwaardes op die laer grens plot, en het verskille met die emperiese waardes van meer as 10% getoon. Hierdie verskille is moontlik veroorsaak as gevolg van 'n oneweredige fisiese model strandhelling of deur die feit dat slegs een helling getoets is. Ten spyte hiervan, het die model oploop waardes binne die bestek van golf- oploop formules geval. Assessering van die veldmetings het 'n beter korrelasie as die fisiese modelresultate getoon, tydens vergelykings met genormaliseerde golf-oploop formules van die emperiese formules. Die oploop waardes van hierdie metings het ook geplot aan die laer grens van die groepering, met verskille van minder as 10% vir die meeste gevalle van die emperiese formules. Wanneer hierdie emperiese voorspellings vergelyk word, is gevind dat die formules wat die beste ooreenstem met die fisiese model, die van Holman (1986) en Stockdon, Howd, & Sallenger Jr. (2006) is. Die emperiese formules van Mase & Iwagake (1984), Hedges & Mase (2004) en Douglas (1992) het die golf-oploop oorvoorspel. Nielsen & Hanslow (1991) het slegs die beste met die strandmetings vergelyk, terwyl De la Pena, Sanchez Gonzalez, Diaz-Sanchez & Martin Huescar (2012) slegs die beste vergelyk het met die fisiese-model resultaat. Hierdie studie ondersteun die formule voorgestel deur Mather, Stretch, & Garland (2011). Deur hul formules op die gemete bevindings toe te pas, is 'n C konstante van 3.3 vir die fisiese model resultate, en 8.0 vir die stranduitlslae bepaal. Beide waardes lê binne die grense wat deur die outeurs voorgestel is. Verdere navorsing het getoon dat moontlike waardes vir die „C‟ konstante tussen 3.0 en 5.0 moet wees vir Iribarren waardes van tussen 0.25 en 0.4. Vir hoër Iribarren waardes, 0.75-0.8, moet die „C‟ kosntante tussen 7.0 en 10 wees; dog is die formule steeds oop vir operateur foute. Die hoofbevindinge van die tesis is gevind dat die beste golf-oploop formules, om tans te gebruik, die van Holman (1986) en Stockdon et.al (2006) is. Hierdie formules kan glad nie beinvloed word deur operateurs foute nie en maak gebruik van die invals golfhoogte, die golfperiode en die strandhelling om die golf-oploop te bepaal.

Given a closed surface Sg of genus g, a mapping class f in \MCG(Sg) is said to be pseudo-Anosov if it preserves a pair of transverse measured foliations such that one is expanding and the other one is contracting by a number \lambda(f). The number \lambda(f) is called a stretch factor (or dilatation) of f. Thurston showed that a stretch factor is an algebraic integer with degree bounded above by 6g-6. However, little is known about which degrees occur. Using train tracks on surfaces, we explicitly construct pseudo-Anosov maps on Sg with orientable foliations whose stretch factor \lambda has algebraic degree 2g. Moreover, the stretch factor \lambda is a special algebraic number, called Salem number. Using this result, we show that there is a pseudo-Anosov map whose stretch factor has algebraic degree d, for each positive even integer d such that d≤g. Our examples also give a new approach to a conjecture of Penner.

Background: Jump height, utilization of the stretch-shortening cycle (SSC) and knee stability is key qualifications and important factors for athletic performance. This is usually practiced with the help of plyometric training. However, plyometric training is considered as an exercise with high-impact that adds stress on the body. Trampoline training is an activity with a growing number of adolescent’s performers, and with the ability to train the same qualities that plyometric training. However, few studies have investigated trampoline trainings effect on jump height, utilization of the SSC and the knee stability in comparison to ordinary plyometric exercises. Aim: The aim of the study was to investigate whether the jump height in a countermovement jump (CMJ) and a squat jump (SJ), the use of SSC and knee stability at landing is different in adolescents who are training using a trampoline and adolescents training using plyometric exercises. Methods: Thirty (n=30) participants, 19 handball players and 11 trampoline practitioners, aged 14-18 years, completed this cross-sectional study. This study involved three tests, a CMJ and a SJ for measuring the jump height and SSCand a double leg drop jump test for measuring the knee stability. Results: The result showed a significant difference in relative jump value between the groups, were the handball group showed a higher value in the CMJ and the SJ compared to the trampoline group. In the utilization of the SSC there were no significant difference between the groups. The result showed that there was a significant difference between the groups knee stability, were the handball group showed a greater knee degrees of varus compared to the trampoline group. Conclusion: Findings from this study suggests that adolescents might benefit from performing plyometric training to achieve a greater jump height and trampoline training to achieve a greater knee stability. Both activities had the same effect on the utilization of theSSC. More studies are needed, including a more homogenous group with larger sample sizes, to support the present results and investigate whether the results are reliable.

Numerical simulations have proven itself as a significant and powerful tool for accurate prediction of turbulent premixed flames in practical engineering devices. The work presented in this thesis concerns the development of simulation techniques for premixed turbulent combustion of three different fuels, namely, CNG, LPG and Hydrogen air mixtures. The numerical results are validated against published experimental data from the newly built Sydney combustion chamber. In this work a newly developed Large Eddy Simulation (LES) CFD model is applied to the new Sydney combustion chamber of size 50 x 50 x 250 mm (0.625 litre volume). Turbulence is generated in the chamber by introducing series of baffle plates and a solid square obstacle at various axial locations. These baffles can be added or removed from the chamber to adapt various experimental configurations for studies. This is essential to understand the flame behaviour and the structure. The LES numerical simulations are conducted using the Smagorinsky eddy viscosity model with standard dynamic procedures for sub-grid scale turbulence. Combustion is modelled by using a newly developed dynamic flame surface density (DFSD) model based on the flamelet assumption. Various numerical tests are carried out to establish the confidence in the LES based combustion modelling technique. A detailed analysis has been carried out to determine the regimes of combustion at different stages of flame propagation inside the chamber. The predictions using the DFSD combustion model are evaluated and validated against experimental measurements for various flow configurations. In addition, the in-house code capability is extended by implementing the Lewis number effects. The LES predictions are identified to be in a very good agreement with the experimental measurements for cases with high turbulence levels. However, some disagreement were observed with the quasi-laminar case. In addition a data analysis for experimental data, regarding the overpressure, flame position and the flame speed is carried out for the high and low turbulence cases. Moreover, an image processing procedure is used to extract the flame rate of stretch from both the experimental and numerical flame images that are used as a further method to validate the numerical results. For the grids under investigation, it is concluded that the employed grid is independent of the filter width and grid resolution. The applicability of the DFSD model using grid-independent results for turbulent premixed propagating flames was examined by validating the generated pressure and other flame characteristics, such as flame position and speed against experimental data. This study concludes that the predictions using DFSD model provide reasonably good results. It is found that LES predictions were slightly improved in predicting overpressure, flame position and speed by incorporating the Lewis number effect in the model. Also, the investigation demonstrates the effects of placing multiple obstacles at various locations in the path of the turbulent propagating premixed flames. It is concluded that the pressure generated in any individual configuration is directly proportional to the number of baffles plates. The flame position and speed are clearly dependent on the number of obstacles used and their blockage ratio. The flame stretch extracted from both the experimental and numerical images shows that hydrogen has the highest stretch values over CNG and LPG. Finally, the regime of combustion identified for the three fuels in the present combustion chamber is found to lie within the thin reaction zone. This finding supports the use of the laminar flamelet modelling concept that has been in use for the modelling of turbulent premixed flames in practical applications.

A dinâmica territorial implementada pelo projeto trecho leste do Rodoanel Mario Covas (SP-021) no município de Ribeirão Pires - SP demonstra toda a problemática da construção e operação de rodovias em áreas de mananciais, além da manutenção do modelo rodoviário como orientador da política de transportes na Região Metropolitana de São Paulo (RMSP). O Estudo (EIA) e o Relatório de Impacto Ambiental (RIMA) são produzidos e organizados como exigências para a obtenção das licenças de construção e operacionalização do empreendimento. Apesar de avançarem na caracterização de aspectos socioambientais e na previsão de impactos para propor ações mitigadoras ou compensatórias, percebe-se que tal medida ainda carece de detalhes e esclarecimentos, uma vez que a população local, afetada em seus bairros e convivendo com os impactos das obras, ainda reclamam e questionam sobre as normas e procedimentos adotados na implementação do empreendimento. Por meio da análise documental dos volumes I, II, III, IV, V e VI do EIA e do RIMA foram levantadas as características apontadas nesses documentos das alterações socioambientais da implementação do trecho leste do Rodoanel no município de Ribeirão Pires, visto que esse município possui como característica o território por completo regulamentado pela legislação de proteção às áreas de mananciais. Os moradores do bairro Pilar Velho por meio de reuniões locais participaram na composição de um Termo de Ajustamento de Conduta (TAC) na tentativa de exigir via ministério público, prefeitura municipal e concessionária responsável pela gestão do empreendimento a adoção de medidas para solução dos problemas apontados. Nesse sentido, a pesquisa apresenta como resultados as falhas dos conteúdos dos EIA RIMA do trecho leste do rodoanel em Ribeirão Pires e levanta a questão sobre os pontos importantes na elaboração de seu conteúdo que devem ser apontados em documentos ambientais futuros de grandes projetos urbanos implementados em áreas de mananciais / The territorial dynamics apllied by the project for the implementation of the eastern section of the Mario Covas Rodoanel (SP-021) in Ribeirão Pires municipality SP demonstrates the whole problem of the construction and operation of highways in water source areas, as well as maintenance of the road model as an guide of the transport policy in the São Paulo Metropolitan Region (RMSP). The Environmental Impact Studies (EIA) and the Environmental Impact Report (RIMA) are produced and organized as requirements for the construction and operationalization licenses of the enterprise. Despite the advances in the attempt to relate socio-environmental aspects and the attempt to predict impacts to propose mitigating or compensatory action, are still not enough to measure that the local population affected in the neighborhoods by an enterprise of this size complain and question the norms and procedures adopted, since they visualize and coexist directly with the impacts of the work. Through documentary analysis of volumes I, II, III, IV, V e VI of the EIA and RIMA, the characteristics indicated in these documents of the socioenvironmental changes of the implementation of the eastern section of the Rodoanel in the Ribeirão Pires city were raised, since this municipality has a characteristic the territory completely regulated by the protection legislation the areas of springs and the population of a neighborhood, the Pilar Velho, through local meetings elaborated a Conduct Adjust Term (TAC) in the attempt to demand via public ministry, municipal prefecture and concessionaire responsible for the project management the adoption of actions to solve the identified problems. In this sense, the research shows as a result the flaws from the contents of EIA - RIMA of the eastern section of the rodoanel in Ribeirão Pires and raises the question about the important points in the elaboration of its content that should be pointed out in future environmental documents of large urban projects implemented in water source areas

During the last decade medical applications of textile sensors have been growing rapidly and textile sensors are the focal research point for many sensor projects. Textile sensors are still not available as a mainstream product to replace conventional electric sensors and electrodes. Textile sensors can be integrated in a textile garment to measure vital signs of a human being. In this regard stretch sensors are able to measure breathing rate of a person. In this project we use seamless knitting technique to make stretch sensors using conductive fibers. The resistance difference between stretching and relaxing of these sensors gives a pattern for human breathing. Four knitting structures with different conductive fibers are made and tested with cyclic tester to construct a graph between resistance and time to find the knitting structure which gives the best results. Tests are also done to check the results after washing. These sensors can be used in breathing monitoring of patients during daily life. / Program: Master Programme in Textile Technology

During the last decade medical applications of textile sensors have been growing rapidly and textile sensors are the focal research point for many sensor projects. Textile sensors are still not available as a mainstream product to replace conventional electric sensors and electrodes. Textile sensors can be integrated in a textile garment to measure vital signs of a human being. In this regard stretch sensors are able to measure breathing rate of a person. In this project we use seamless knitting technique to make stretch sensors using conductive fibers. The resistance difference between stretching and relaxing of these sensors gives a pattern for human breathing. Four knitting structures with different conductive fibers are made and tested with cyclic tester to construct a graph between resistance and time to find the knitting structure which gives the best results. Tests are also done to check the results after washing. These sensors can be used in breathing monitoring of patients during daily life. / Program: Master programme in Textile Technology

This study investigated the effects of peristaltic pulse dynamic compression (PPDC) on range-of-motion (ROM) changes in forward splits. Serious stretching usually involves discomfort and large time investments. Tissue structural changes and stretch tolerance have heretofore been considered the primary mechanisms of enhanced ROM. The PPDC treatment was computer controlled. Circumferential and segmented inflation pressures were induced by feet to hip leggings. Nine subjects, experienced in stretching and a forward split position, volunteered. The subjects were familiarized with the protocol and randomly assigned to an initial condition: experimental (PPDC), or control (CONT). The study involved a crossover design. Second conditions were tested within 1–5 days. All tests were 2 trials of right and left forward splits. Split flexibility was assessed by measuring the height of the anterior superior iliac spine of the rear leg from the floor. Pelvic posture was controlled by rear leg position. The PPDC treatment was 15 minutes of seated PPDC. The control condition was the same except that leggings were not inflated. Pressures of 5 cells in the leggings were set at factory defaults, 70 mm Hg sequentially. Difference score results indicated statistically significant (p ≤ 0.05) differences by condition and the condition by leg interaction. The rapid acute changes in ROM (PPDC: right 25.3%, left 33.3%; CONT: right 12.2%, left 1.0%) support the premise that changes in ROM were dependent on mechanisms other than tissue structural changes and/or stretch tolerance. PPDC provides a means of rapidly enhancing acute ROM requiring less discomfort and time.

No description available.