The master’s thesis is focused on the proposal of working part of the hydraulic circuit for the hydraulic press with a press force 400 kN. The thesis contains justifiable structural design of the linear hydraulic motor, which includes material choices, necessary calculations and simulations of material strength characteristics and the choice of the individual components. The thesis also includes a proposal of “heel valve” including the choice of individual components and basic function calculation of the hydraulic circuit of the hydraulic press.

Plantar heel pain is commonly encountered by clinicians. Various conditions, such as plantar fasciopathy, myofascial syndrome and entrapment of the tibial, plantar and calcaneal nerves at the tarsal tunnel can cause plantar heel pain. This diversity in aetiology makes the diagnosis and treatment challenging. There are limited studies on pain mechanisms in patients with planter heel pain. There is no gold criterion standard for the diagnosis. Although various interventions have been reported, no specific treatment approach has yet been identified as being most effective. The first aim of this thesis was to critically appraise the literature on plantar heel pain of neural origin. Various databases were searched for peer-reviewed articles that predominantly focused on neurogenic plantar heel pain or that discussed relevant biomechanics of the tibial, plantar and calcaneal nerves. This review revealed inconsistency in the literature regarding the diagnosis and treatment of neurogenic plantar heel pain. There also was a lack of evidence for treatment approaches although the majority of patients with plantar heel pain are reported to improve with conservative treatment. The second aim of this thesis was to examine the biomechanical effects of clinical tests and combination of movements on various structures associated with plantar heel pain. This aim was achieved through cadaver studies (Study 1–3), in which strain in the plantar fascia and the nerves of the lower limb, and excursion of the nerves were measured during various movements and positions of the lower limb. Study 1 examined the Dorsiflexion-eversion test used to diagnose tarsal tunnel syndrome (TTS) and the Windlass test for plantar fasciopathy given the similarity between both tests. Both the Dorsiflexion-eversion and Windlass tests significantly increased strain in the structures that are commonly associated with plantar heel pain (the tibial and plantar nerves and plantar fascia). This suggests that the usefulness of the Dorsiflexion-eversion and Windlass tests in the differential diagnosis of plantar heel pain might be limited. Study 2 investigated the influence of different positions in adjacent joints on nerve biomechanics during ankle and toe movement. Increased strain in the tibial nerve at the ankle and plantar nerves associated with ankle and toe movement was significantly higher when the nervous system was pre-tensioned at a more proximal joint. Strain was even higher when the nerve bed was pre-tensioned at two joints. Study 3 examined a modified straight leg raising (SLR) test in which ankle dorsiflexion is performed before hip flexion. This test has been suggested to diagnose distal neuropathies such as TTS. During the modified SLR, the excursion and strain in the sciatic nerve associated with hip flexion were transmitted distally along the nerve from the hip to the foot. As a result, the strain in the nerves around the foot and ankle increased significantly during hip flexion. This movement did not affect plantar fascia strain. Consequently, the modified SLR may be a useful test to differentially diagnose plantar heel pain. This test warrants future research to evaluate its clinical use in patients with neurogenic plantar heel pain. The third aim of this thesis was to determine the reliability of high-resolution ultrasound for measuring the cross-sectional area of the tibial nerve at the tarsal tunnel and to compare the tibial nerve size between people with and without plantar heel pain. Study 4 investigated intra and intertester reliability in 10 participants without plantar heel pain by calculating intraclass correlation coefficients, measurement error and smallest detectable difference (SDD). Intra and intertester reliability were excellent, with very small measurement error and SDD. Tibial nerve enlargement in an individual patient by as little as 1.8 mm2 can be detected reliably with high-resolution ultrasound. The use of average value of three scans is recommended to compare between the involved and uninvolved side. Differences in the nerve size between 26 patients with plantar heel pain and 20 control participants were also analysed. There was no significant difference in tibial nerve size between both groups. Future research is needed to investigate the tibial nerve size in patients with proven TTS using ultrasonography. The fourth aim of this thesis was to investigate the characteristics of plantar heel pain through Study 5 for the same group of patients and control participants as in Study 4. Several self-report measures on pain and quality of life were used. Clinical tests and quantitative sensory tests (QST) were performed at local and remote sites on the involved and uninvolved side in the patients and on one side in the control participants. In the patients, mechanical hyperalgesia was the main finding as demonstrated by changes in palpation and pressure pain threshold. Other findings were changes in current thresholds, vibration threshold and thermal perception thresholds. These results suggest the existence of sensory changes that likely indicates change in peripheral and central pain processing. It is recommended to utilise a multidimensional pain assessment for patients with plantar heel pain. The findings in this thesis are important for the diagnosis and treatment of plantar heel pain. For future research, the results suggest to use fresh cadavers when investigating biomechanics of the clinical tests and nerve gliding exercises that are used for patients with plantar heel pain. It is also suggested to evaluate the cross-sectional area of the tibial nerve at the tarsal tunnel, the QSTs and all other diagnostic measurements in this thesis in patients with neurogenic plantar heel pain or patients with TTS.

Made available in DSpace on 2016-12-06T17:07:11Z (GMT). No. of bitstreams: 1 Alexandre Pinho.pdf: 2648154 bytes, checksum: 89f3e208e24484e5c16db812840b299c (MD5) Previous issue date: 2005-08-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The aim of this work was to investigate the relation of the vertical component of the ground reaction forces and the plantar pressure distribution during standing position, acting under the forefoot and the rearfoot, using high heel shoes and high heel simulators (wooden blocks of different heights and angles of heel support). The subjects were 30 symptom-free volunteer women, with no apparent foot and leg pathologies, with body mass index (BMI) up to 30 (Pollock, 1993) who are used to wear high heel shoes at least once a week. To obtain the relations on the weight force application and the pressure distribution under the feet the subjects were positioned standing over two force plates AMTI (Massachusetts, EUA, 1991) at 60Hz, synchronized with a pair of pedar mobile insoles (pedar® novelgmbh © 2005) at 50Hz. The foot was divided in two areas and data was acquired in 10 seconds of self balanced position. Significant differences between the means of vertical force and plantar pressure were found related to the heights differences and angle differences (p< 0,001), at the wearing shoes situation and with the simulators. The results of force and pressure did not follow a linear relation but increased as the heel height support got higher in both situations. / Este trabalho visou investigar a aplicação da força peso relativo ao peso corporal em retropé através da componente vertical da força de reação do solo (Fz) e a distribuição de pressão plantar nas regiões do retropé e antepé, na posição estática, em apoio bipodal, através do uso de calçados de salto e simuladores de altura e de ângulo de apoio do calcâneo. Participaram deste estudo 30 mulheres voluntárias, sem histórico de patologias em membros inferiores nos últimos 12 meses, sem índices de massa corporal que indicassem padrões de obesidade, segundo Pollock, (1993) e habituadas a utilizar calçado de salto pelo menos uma vez por semana. Os indivíduos utilizando calçados variados e blocos simuladores se posicionaram sobre duas plataformas de força AMTI (Massachusetts, EUA, 1991) dispostas em série adquirindo dados a uma freqüência de 60 Hz de forma sincronizada a um sistema de medição de distribuição de pressão plantar através de palmilhas sensorizadas (pedar® novelgmbh © 2005) adquirindo a uma freqüência de 50 Hz pelo tempo de 10 segundos. Verificou-se para a variável força vertical (Fz) diferenças significativas entre as médias tanto em relação às alturas (p< 0,001), como entre os ângulos (p< 0,001), obtendo-se similarmente nas situações real e simulada, ao nível de significância de 5%, um padrão não linear de diminuição da força vertical (Fz) em retropé e da pressão plantar nesta mesma região à medida que a altura do apoio no calcâneo aumenta.

Previous research has shown that with advancing age, there are increasing incidences of slip and fall injuries. Understanding mechanisms associated with gait adjustments across a known slippery surface may help in proactively avoiding slips and falls. The primary goal of this study involved examination of gait parameters and muscle activity characteristics of the lower extremities during two different walking conditions. Research has shown that both physical and mental changes accompany the aging process in humans. Moreover, research has shown that emotions and physiological responses are related. A secondary goal of this study was to examine the relationships of fear of falling with gait parameters and muscle activity. This study consisted of exposing 14 younger and 14 older participants to controlled slippery conditions safely, while studying normal and adjusted gait characteristics (friction requirement, heel contact velocity, and step length) and muscle activity characteristics (Integrated EMG). First, a baseline measure was done to study normal gait prior to any exposure to slipping. A second measure was done following a slip from a contaminated floor surface, but before the initiation of a second slip. The results indicate that there were significant gait parameter differences between younger and older participants for both walking conditions. Results also indicate that there were differences in muscle activity between to the two age groups for the adjusted condition. Findings suggest that older individuals require an additional step to properly adjust gait for a contaminated walking surface. / Master of Science

Currently at the Savannah River Site (SRS), there are fifteen single-shell, 3.6-million liter tanks containing High Level Waste. To close the tanks, the sludge must be removed. Mechanical methods have had limited success. Oxalic acid cleaning is now being considered as a new technology. This research uses sample results and chemical equilibrium software to develop a preferred flowsheet and evaluate the acceptability of the system impacts. Based on modeling and testing, between 246,000 to 511,000 l of 8 wt% oxalic acid were required to dissolve a 9,000 liter Purex sludge heel. For SRS H-Area modified sludge, 322,000 to 511,000 l were required. To restore the pH of the treatment tank slurries, approximately 140,000 to 190,000 l of 50 wt% NaOH or 260,000 to 340,000 l of supernate were required. When developing the flowsheet, there were two primary goals to minimize downstream impacts. The first was to ensure that the Resultant oxalate solids were transferred to DWPF, without being washed. The second was to transfer the remaining soluble sodium oxalates to the evaporator drop tank, so they do not transfer through or precipitate in the evaporator pot. Adiabatic modeling determined the maximum possible temperature to be 73.5°C and the maximum expected temperature to be 64.6°C. At one atmosphere and at 73.5°C, a maximum of 770 l of water vapor was generated, while at 64.6°C a maximum 254 l of carbon dioxide were generated. Although tank wall corrosion was not a concern, because of the large cooling coil surface area, the corrosion induced hydrogen generation rate was calculated to be as high as 10,250 l/hr. Since the minimum tank purge exhaust was assumed to be 5,600 l/hr, the corrosion induced hydrogen generation rate was identified as a potential concern. Excluding corrosion induced hydrogen, trending the behavior of the spiked constituents of concern, and considering conditions necessary for ignition, energetic compounds were shown not to represent an increased risk Based on modeling, about 56,800 l of Resultant oxalates could be added to a washed sludge batch with minimal impact on the number of additional glass canisters produced. For each sludge batch, with 1 to 3 heel dissolutions, about 60,000 kg of sodium oxalate entered the evaporator system, with most collecting in the drop tank, where they will remain until eventual salt heel removal. For each 6,000 kg of sodium oxalate in the drop tank, about 189,000 l of Saltstone feed would eventually be produced. Overall, except for corrosion-induced hydrogen, there were no significant process impacts that would forbid the use of oxalic acid in cleaning High Level Waste tanks. / MATHEMATICAL SCIENCES / M. Tech. (Chemical Engineering)

Im Mittelpunkt dieser kumulativ angefertigten Arbeit stehen fünf verschiedenartige biomechanische Untersuchungen faseriger Bindegewebe, welche in einer Gesamtschau zusammengeführt werden. Die einzelnen Beiträge setzen sich zusammen aus Untersuchungen zum Einfluss zellulärer Bestandteile auf die mechanischen Eigenschaften faseriger Bindegewebe und die Beeinflussung dieser Ergebnisse durch Messfehler, speziell am Beispiel des Materialschlupfs. Über diese beiden Beiträge wird eine Verbindung hergestellt zur rechnergestützten Simulation der Wirkung eines Beckenkompressionsgurts auf die Bänder des Beckenrings und dem Transmissionsverhalten faseriger Bindegewebe bei Zugbelastung. Im fünften Beitrag wird am Beispiel des Zusammenwirkens von Achillessehne, Fersenfettpolster und Plantarfaszie in vitro die Komplexität der Betrachtung faseriger Bindegewebe aufgezeigt. Die Zusammenführung der einzelnen Untersuchungen wird begleitet von der Frage, ob die bestehenden biomechanischen Untersuchungsansätze ausreichend sind, um ein umfassendes Verständnis zur funktionellen Bedeutung faseriger Bindegewebe aufbauen zu können.

Chronic, noncommunicable diseases such as chronic fatigue syndrome (also known as myalgic encephalomyelitis) are rapidly becoming a worldwide epidemic that profoundly affects public health and productivity. Chronic fatigue syndrome (CFS) is characterised by severe and debilitating fatigue and although its etiology is still unknown, recent studies have found considerable evidence that mitochondrial dysfunction and oxidative stress might be responsible for the underlying energy deficit in these patients. Adenine and pyridine nucleotides could be used as potential biomarkers for energy related disorders such as chronic fatigue syndrome because of their various functions in the energy and redox pathways. The first part of this study focussed on developing a liquid chromatography electrosprayionisation tandem mass spectrometry (LC-ESI-MS/MS) method for the quantification of these nucleotides in blood samples. Due to the instability of nucleotides in biological matrices it was also necessary to find a suitable extraction method that would be able to stop enzymatic activity via protein precipitation. Out of the four extraction methods investigated during this study, deproteinisation of whole blood samples with perchloric acid produced the highest nucleotide abundances. Although nucleotide standards were found to be stable in perchloric acid, nucleotide levels in blood samples were not stabilised by addition of perchloric acid. The second part of this study consisted of measuring the nucleotide levels in blood samples of controls and possible CFS patients in order to test the proof of concept of the new LCESI- MS/MS method. Despite changes in the nucleotide levels due to perchloric acid and problems with nucleotide instability, it was still possible to distinguish between the two groups based on the results obtained with the new LC-ESI-MS/MS method. The newly developed LC-ESI-MS/MS method proved to be reliable and adequate for nucleotide quantification in whole blood samples, thus the aim of this study was achieved. / MSc (Biochemistry), North-West University, Potchefstroom Campus, 2014

Durant les premières années de marche indépendante, l'enfant voit sa stratégie de marche évoluer. De plus, il est rapidement amené à porter des chaussures dont l'influence sur sa marche est peu connue, même si documentée dans certains domaines particuliers (e.g. cas pathologiques, sport). Cette thèse consiste en la mesure de plus de 100 enfants sains, âgés entre 1 et 7 ans, marchant pieds nus et avec des chaussures spécifiquement développées pour l'étude (3 éléments variables : hauteur de talon, dureté de semelle et hauteur de tige). Des âges-clés, correspondant à l'âge où les paramètres biomécaniques sont semblables à ceux de l'adulte, ont été mis en évidence : 4 ans pour la cheville, 6 ans pour la hanche, et 7 ans pour le genou. Des régressions sur les paramètres biomécaniques en fonction de l'âge et de la vitesse de marche ont également été développées afin de servir de référence de population saine pour les études cliniques. Les mesures avec les chaussures ont révélé une influence prépondérante de la hauteur de talon sur la marche (e.g. mobilisation plus importante de la cheville avec un talon plus haut). À l'inverse, une tige haute sollicite moins la cheville au cours de l'appui. La dureté de semelle est relativement peu influente sur les paramètres de marche. Cette thèse a permis de préciser les résultats mis en évidence sur la maturation de la marche pieds nus et d'apporter des premières réponses aux industriels français de la chaussure enfant sur l'influence des éléments de conception de leurs produits sur la marche. Des futures mesures, plus nombreuses, permettraient de conclure sur l'influence croisée de ces éléments de conception / During first years of independent walking, children gait changes. Moreover, children wear shoes soon. Although gait of specific population was largely studied (e.g. pathological people, sports), shoe influence on young children gait is quite unknown. This thesis includes measurement of young children walking barefoot and wearing shoes especially designed for this study (3 variables components: heel height, upper height and sole hardness). For barefoot gait, a large database of biomechanical parameters was obtained, including more than 100 children aged between 1 and 7 years old. Key age were identified, corresponding to the age when biomechanical parameters are identical to adults’: 4 years for the ankle, 6 years for the hip and 7 years for the knee. Regressions between biomechanical parameters, age and speed were also established as a reference of healthy children for clinical application. Shoed measurements revealed leading influence of heel height on gait (e.g. more ankle mobilization with higher heel). Contrarily, high upper limits ankle movement during stance phase. Sole hardness poorly influences gait parameters. This thesis precises previous results obtained on gait maturation and delivers indications on shoe conception influence on gait for French children’s shoes manufacturers. Further measurements may allow conclusion about cross influence of shoe conception elements on children gait

Chronic, noncommunicable diseases such as chronic fatigue syndrome (also known as myalgic encephalomyelitis) are rapidly becoming a worldwide epidemic that profoundly affects public health and productivity. Chronic fatigue syndrome (CFS) is characterised by severe and debilitating fatigue and although its etiology is still unknown, recent studies have found considerable evidence that mitochondrial dysfunction and oxidative stress might be responsible for the underlying energy deficit in these patients. Adenine and pyridine nucleotides could be used as potential biomarkers for energy related disorders such as chronic fatigue syndrome because of their various functions in the energy and redox pathways. The first part of this study focussed on developing a liquid chromatography electrosprayionisation tandem mass spectrometry (LC-ESI-MS/MS) method for the quantification of these nucleotides in blood samples. Due to the instability of nucleotides in biological matrices it was also necessary to find a suitable extraction method that would be able to stop enzymatic activity via protein precipitation. Out of the four extraction methods investigated during this study, deproteinisation of whole blood samples with perchloric acid produced the highest nucleotide abundances. Although nucleotide standards were found to be stable in perchloric acid, nucleotide levels in blood samples were not stabilised by addition of perchloric acid. The second part of this study consisted of measuring the nucleotide levels in blood samples of controls and possible CFS patients in order to test the proof of concept of the new LCESI- MS/MS method. Despite changes in the nucleotide levels due to perchloric acid and problems with nucleotide instability, it was still possible to distinguish between the two groups based on the results obtained with the new LC-ESI-MS/MS method. The newly developed LC-ESI-MS/MS method proved to be reliable and adequate for nucleotide quantification in whole blood samples, thus the aim of this study was achieved. / MSc (Biochemistry), North-West University, Potchefstroom Campus, 2014

Currently at the Savannah River Site (SRS), there are fifteen single-shell, 3.6-million liter tanks containing High Level Waste. To close the tanks, the sludge must be removed. Mechanical methods have had limited success. Oxalic acid cleaning is now being considered as a new technology. This research uses sample results and chemical equilibrium software to develop a preferred flowsheet and evaluate the acceptability of the system impacts. Based on modeling and testing, between 246,000 to 511,000 l of 8 wt% oxalic acid were required to dissolve a 9,000 liter Purex sludge heel. For SRS H-Area modified sludge, 322,000 to 511,000 l were required. To restore the pH of the treatment tank slurries, approximately 140,000 to 190,000 l of 50 wt% NaOH or 260,000 to 340,000 l of supernate were required. When developing the flowsheet, there were two primary goals to minimize downstream impacts. The first was to ensure that the Resultant oxalate solids were transferred to DWPF, without being washed. The second was to transfer the remaining soluble sodium oxalates to the evaporator drop tank, so they do not transfer through or precipitate in the evaporator pot. Adiabatic modeling determined the maximum possible temperature to be 73.5°C and the maximum expected temperature to be 64.6°C. At one atmosphere and at 73.5°C, a maximum of 770 l of water vapor was generated, while at 64.6°C a maximum 254 l of carbon dioxide were generated. Although tank wall corrosion was not a concern, because of the large cooling coil surface area, the corrosion induced hydrogen generation rate was calculated to be as high as 10,250 l/hr. Since the minimum tank purge exhaust was assumed to be 5,600 l/hr, the corrosion induced hydrogen generation rate was identified as a potential concern. Excluding corrosion induced hydrogen, trending the behavior of the spiked constituents of concern, and considering conditions necessary for ignition, energetic compounds were shown not to represent an increased risk Based on modeling, about 56,800 l of Resultant oxalates could be added to a washed sludge batch with minimal impact on the number of additional glass canisters produced. For each sludge batch, with 1 to 3 heel dissolutions, about 60,000 kg of sodium oxalate entered the evaporator system, with most collecting in the drop tank, where they will remain until eventual salt heel removal. For each 6,000 kg of sodium oxalate in the drop tank, about 189,000 l of Saltstone feed would eventually be produced. Overall, except for corrosion-induced hydrogen, there were no significant process impacts that would forbid the use of oxalic acid in cleaning High Level Waste tanks. / MATHEMATICAL SCIENCES / M. Tech. (Chemical Engineering)