Dry abrasive blasting is a commonly used surface preparation operation by many process industries to clean up metallic surfaces and achieve surface finishes suitable for future adhesion. Abrasives used in this process can be recyclable or expendable. This study was undertaken to evaluate the performance of three recyclable abrasives: garnet, barshot and steel grit/shot in terms of productivity (area cleaned per unit time), consumption (amount of abrasive used per unit area cleaned) and uncontrolled total particulate matter (TPM) emission factors (in terms of mass of pollutant emitted per unit area cleaned and mass of pollutant emitted per unit mass of abrasive consumed). Though there have been various attempts in the past to evaluate the performance of these abrasives, there has not been a streamlined approach to evaluate these parameters in the commonly used range of process conditions, or to identify and model the influences of key process variables on these performance parameters. The first step in this study was to evaluate the performance of these three abrasives in blasting painted steel panels under enclosed blasting conditions and using USEPA recommended protocols. The second step was to model the influences of blast pressure and abrasive feed rate, two most critical parameters on productivity, consumption and emission factors. Two and three dimensional models were obtained using multiple linear regression techniques to express productivity, consumption and TPM emission factors in terms of blast pressure and abrasive feed rate. Barshot was found to have high productivities over all and steel grit/shot demonstrated the least emission potential at almost all of the tested pressure and feed rate conditions. The data will help fill the gaps in literature currently available for dry abrasive blasting performance. The models obtained will help industries, the research community and the regulatory agencies to make accurate estimates of the performance parameters. Estimating productivity and consumption will help industries identify best management practices by optimizing the process conditions to achieve high productivity and low consumption rates. Emission factor determination will help in reducing the emissions to the atmosphere by choosing process conditions corresponding to minimum emissions. The performance parameters once optimized can result in reduction in material, labor, energy, emission and disposal costs, lower resource utilization and hence reduction in overall life cycle costs of dry abrasive process. The developed models will help industries in making environmentally preferable purchases thereby promoting source reduction options. PM emissions estimated using the models presented here will aid studies on health risk associated with inhalation of atmospheric PM.

The purpose of this study is to investigate the effects of a marbled coating applied on a triaxial woven structure. Although both of these techniques are traditionally used for many years, they are nowadays utilized in innovative ways, the marbling being applied on a large variety of surfaces such as wooden floors or ceramics and the triaxial weave being used as a hi-tech material for sports or in the automotive industry and having applications in diverse fields, from art to architecture. Their fusion, however, is a topic that has yet to be thoroughly explored, which makes for the motive of this thesis work, as an opening has been observed for the exploration of the expressive power of their combination. The experimental approach that has been taken towards this exploration will determine how the marbling effect may contribute to the visual expression of the structure. Multiple cycles of experiments have been conducted in an attempt to understand the behaviour of the chosen materials and their combination, the effect that various colour combinations have and the best possible pairings between the elements. The organic marbling combined with the geometric triaxial weave proved to generate the most powerful visual expression and the clearest result out of all the experiments. Thus five experimental textiles were developed in order to illustrate different aspects of this complex relationship, where the marbling would affect the visual expression of the structure by either enhancing or concealing the structural aspect and the contrast between the graphic element and the organic one would be a constant presence throughout the work. This work pushes the boundaries of conventional textile design and through the application of a textile thinking to unconventional materials a different type of expression is born. By mixing a limited amount of variables in multiple ways, a large range of visual effects may be achieved.

Au travers de l'évaluation d'indices quantitatifs, ce travail se focalise sur l'analyse biomécanique de la redondance et des coordinations motrices du membre supérieur lors de la réalisation du mouvement de préhension. En nous basant sur la théorie de « l'uncontrolled manifold », nous abordons, d'une part, un aspect particulier de la notion de synergie qui est relatif à la covariation des paramètres d'état du système afin de stabiliser une variable de performance. En effet, la thématique de la redondance motrice qui est une des caractéristiques principale du système musculo-squelettique a été récemment reformulée. Dans ce cadre, il est postulé que les degrés de liberté ne sont jamais éliminés comme le suggère la théorie proposée par Bernstein mais combinés afin d'assurer performance et flexibilité. D'autre part, nous utilisons un indice issu de la robotique, la manipulabilité permettant d'évaluer les capacités de déplacement du poignet au cours de ce mouvement de saisie. L'objectif de ce travail consiste à appliquer ces deux analyses à des mouvements contraints ou altérés afin d'identifier les modifications de la coordination motrice par rapport à des conditions contrôles. Dans cette optique, la première analyse consiste à évaluer l'effet d'une contrainte spatiale matérialisée par un obstacle lors de la phase d'approche d'un mouvement de préhension par une mesure des paramètres cinématiques du membre supérieur. La seconde étude vise à identifier la coordination motrice du membre supérieur de sujets atteints d'une lésion médullaire et souffrants de tétraplégie par une analyse combinée des paramètres électromyographiques (EMG) de certains muscles impliqués et des paramètres cinématiques. Pour cela nous avons mis en place deux protocoles expérimentaux au cours desquels les angles articulaires du membre supérieur ainsi que le signal EMG ont été évalués par des moyens adaptés. En présence d'un obstacle, nos résultats montrent de manière classique que la position du poignet est stabilisée au travers d'une synergie articulaire. De plus, il semble que la présence d'une contrainte spatiale renforce les synergies pour stabiliser la trajectoire du coude dans la seconde partie du mouvement correspondant au franchissement de l'obstacle. Ce renforcement se caractérise par une utilisation accrue de configurations articulaires équivalentes. Ce résultat suggère que l'augmentation de la flexibilité des configurations articulaires serait un mécanisme par lequel le système nerveux central pourrait prendre en compte la présence d'une contrainte spatiale. Parallèlement, la présence de l'obstacle entraine des modifications de la manipulabilité du poignet. Pour les sujets souffrants de tétraplégie, l'analyse EMG a montré une compensation de la faiblesse ou la paralysie de certains muscles, le triceps brachial notamment, par une augmentation de l'activité relative des muscles de l'épaule. De plus, ces sujets présentent une décomposition de la variance des angles articulaires similaire à celle du groupe contrôle suggérant que, malgré la présence d'une déficience motrice, la flexibilité des configurations articulaire au cours de l'exécution du mouvement est toujours présente ou a été récupérée. De même pour la manipulabilité, les patients présentent de fortes similitudes avec les sujets valides avec, dans certains cas, des valeurs de manipulabilité du poignet supérieures. Ces résultats nous amènent à penser que l'étude des synergies au travers des indices proposés pourrait constituer un outil intéressant afin d'étudier l'impact d'une contrainte et d'une déficience motrice sur les paramètres biomécaniques du mouvement. Les présents travaux ouvrent des voies intéressantes pour des applications dans le domaine de la simulation du mouvement et de l'évaluation fonctionnelle de la coordination de sujets déficients moteurs en vue d'évaluer et améliorer la rééducation par l'apport d'informations quantitatives aux cliniciens.

Recently, every main country in the world has implemented transfer pricing system in order to ensure every multinational enterprise would also be able to pay their taxes equitably and reasonably to the countries which they established their multinational enterprises, and has requested the prices of business transaction between every related party have to be set up and adjusted by arm¡¦s length principle. Moreover, in order to follow the initiative of OECD, adopt the current world trend, and avoid the higher inspection risk for our enterprises, Taiwan has established the method of regulation on December twenty- eighth, 2004 by consulting OECD guidelines and tax law of every country in the world, and has started to implement transfer pricing system. The Taiwanese transfer pricing system has integrated in many ways and in many-sided. It also has extended globally. If everyone could cooperate with mutual benefit, the transfer pricing system would be able to maintain the right of native taxation and effectively protect the right of multinational enterprises; hence it is not only a tax system, but art. Therefore, the checking model of transfer pricing system is very different from the case of normal profit-seeking enterprises. The checking model of the current tax authority mainly focuses on their jurisdiction and formal conditions, so it is interesting to see if our tax authority has capability of doing transfer pricing case which emphasizes on the point of taxation principles in substance or not. In addition, because our profit-seeking enterprises are mainly small or middle size corporations, there is a challenge to them to meet their duty and to provide all the requested certificates under the request of the new system, so it is also a point to discuss with. In this research, I tried to establish an evaluation standard by consulting policy estimated theory, and designed a survey which has collected all of recently related books, articles, references, and practiced thoughts in order to have an objective investigation. Also, in the survey, I would like to look into the situations of the following three points after practice of transfer pricing system. First, I would like to find out the thoughts of related interested parties after practice of this policy. Finally, what satisfactions of appropriateness, neutrality, efficiency, responsiveness, and side-effects externalities would be in this policy efficiency analysis? In addition, the collected data were analyzed with Chi-Square test, cross analysis, one-way ANOVA, multiple comparison analysis, and correlation analysis. In my major research findings, transfer pricing system has been known in the certain level by every related interested party. Moreover, this policy is in the high appropriate level and efficient level. However, this policy is in the low neutral level of land tax and other levies, and in the low responsive level. Therefore, there are other side effects in this policy as well, such us: increasing tax misgiving from every enterprise, increasing taxation, and checking cost, etc,. Also, in the result of this research paper, there are twelve suggestions that have collected from the responses of the survey, the problem finding, and some practical difficulties from the study of research institute and some other comments. These twelve suggestions could provide to related government organization as reference material in order to revise the law and advance tax system and tax policy.

Extensive research has documented the stereotypical kinematic and kinetic patterns in healthy human walking, but we have a limited understanding of the neuromechanical control principles that contribute to their execution. Furthermore, the strategies used to adapt human walking to morphological or environmental constraints are poorly understood. After a traumatic injury, like amputation, regaining independent mobility is a primary goal of rehabilitation. Without a clear understanding of the neuromechanical principles governing locomotion, monitoring and quantitatively improving gait rehabilitation outcomes is challenging. The purpose of this doctoral work was to identify controlled variables in able and impaired human walking and to compare the control strategies used to adapt to a novel walking environment both with and without amputation. I apply an uncontrolled manifold (UCM) analysis to test whether likely goal variables of human walking are selectively stabilized through step-to-step variability structure. I found that both able-bodied subjects and subjects with an amputation maintain consistent whole body dynamics and leg power production by exploiting inherent motor abundance. Consistent leg power production is accomplished primarily through step-to-step leg force corrections that are driven by variable timing of ankle torque production. Covariance between ankle and knee torques enable robust motor control in able-bodied individuals, but this stabilizing mechanism is absent in individuals with a transtibial amputation. This coordinated joint torque control also appears to assist able-bodied short-term adaptation, invoked by split-belt treadmill walking. However, loss of ankle motor control and distal sensory feedback due to amputation appears to limit reactive, feedback driven adaptation patterns in subjects with an amputation. Ultimately, this work highlights the role of intact distal sensorimotor function in locomotor control and adaptation. The major findings I present have substantial implications for gait rehabilitation and prosthetic design.

<p>Tool use is an important area of research in psychology, neurophysiology, and motor behavior because it provides insights into the organization of perception, cognition, and action. Tool use research has traditionally focused on the neural structures or cognitive processes that contribute to body-tool integration, while there has been comparatively little interest in motor control. When tool use actions are studied, adaptations have mainly been examined at the level of manual control, while postural control and multi-segment coordination have received less attention. Examining these components of behavior in the context of tool use is vital for developing a better understanding of how humans integrate tools into goal-directed actions.</p><p>The goals of this dissertation were to 1) characterize adaptations to postural control over time when performing a manual task with a tool under different levels of postural constraint and determine their relation to manual task performance, 2) examine postural-manual coupling under different levels of postural constraint during tool use, and 3) determine how multi-segment coordination supports postural stability and suprapostural task performance under different levels of postural constraint during tool use. To address these questions, we adopted a sensorimotor adaptation paradigm to examine postural-manual control and multi-segment coordination before, during, and after an extended bout of tool use.</p>Tool-use adaptations were found to extend beyond the end-effector. Postural control played a crucial role in facilitating improvements in the manual control of tools. Placing constraints on posture interfered with these adaptations, disrupting the coordination of postural-manual behaviors during tool use. However, multi-segment coordination was modified to overcome this challenge and facilitate postural stability and manual performance. These results demonstrate that healthy young adults are capable of flexibly recruiting and exploiting available degrees of freedom in a task-dependent manner the potential challenges associated with integrating tools into movements. This dissertation provides preliminary support for the importance of considering postural control in tool use actions and highlights the utility of examining interactions across multiple levels of motor behavior—postural control, manual control, postural-manual coupling, and multi-segment coordination—to elucidate how tools are integrated into complex, goal-directed behaviors.

Background: Resistant hypertension (RH) is defined as blood pressure (BP) that remains elevated (>140/90mmHg) despite being treated with an antihypertensive regimen of 3 or more medications from different classes, including a long-acting calcium channel blocker, an angiotensin converting enzyme inhibitor or angiotension receptor blocker and a diuretic. The prevalence of RH in South Africa is currently unknown, however, clinical reports suggest that it is not rare. Patients with RH are significantly predisposed to cardiovascular (CV) diseases compared to patients with controlled BP. Consequences of RH include left ventricular hypertrophy, heart failure, ischaemic heart disease, chronic kidney disease leading to end-stage renal disease, stroke, vascular dementia, CV death and peripheral arterial disease. A proportion of patients with RH who never achieve BP control despite maximal medical treatment, represent a potentially novel and distinctive phenotype which is different from RH patients whose BP canbe controlled. Recognising and categorising such patients becomes the initial and crucial step in stratifying phenotypes and defining mechanisms of treatment resistance. Objectives: The aim of this study was to identify patients with resistant uncontrolled hypertension (RUH) and compare phenotypes in these patients to resistant controlled hypertensives (RCH). Methods: We enrolled 50 patients from the Groote Schuur Hospital Hypertension Clinic: a teriary referral hospital for RH. Patients on 4 or more antihypertensive medication including a diuretic, with BP< 140/90mmHg were considered RCH, and those with BP ≥ 140/90 considered RUH. Assessments included clinical examination, electrocardiography, echocardiography, applanation tonometry, serum biomarkers and cardiovascular magnetic resonance (CMR - which included biventricular volumes and function, myocardial strain, tissue characteristics and late gadolinium enhancement - LGE). Results: Thirty were diagnosed with RUH and twenty with RCH. Patients with RUH were more likely to have a longer duration since diagnosis of hypertension (10.5±10.7 vs. 3.6±3.4, p=0.02) and more likely to be on treatment that included an ACE-inhibitor (90% vs. 58%, p=0.01). As expected, patients with RUH had significantly higher systolic BP (155.6±21.6 vs. 137.8±16.5 mmHg, p< 0.001), diastolic BP (88.4±14.5 vs. 77.5±13.6 mmHg, p= 0.03), mean arterial BP (115.4±17.2 vs 101±15.3 mmHg, p= 0.004) and pulse pressure (67.3±14.2 vs. 60.1±12.4 mmHg, p=0.001). Further, RUH patients had significantly lower large artery elasticity (12.5±4 vs 14.7±3.8ml/mmHgx100, p=0.08) and lower small artery elasticity (4.1±2.1 vs. 6.9±3.6ml/mmHgx100, p< 0.001). RUH patients also had a higher systemic vascular resistance (1754±418.4 vs. 1363±371.5dyneXsecXcm-5, p=0.002). On CMR, RUH patients had lower right ventricular (RV) end-systolic and end-diastolic volumes (p=0.02), as well as higher indexed left ventricular mass (LVMI) (61.6±17.6 vs 52.9±13.9 g/m2 , p= 0.06). There were no differences in native T1, extracellular volume quantification and LGE volume fraction between RUH and RCH patients. Conclusions: Patients with RUH have a greater involvement and more severe CV phenotype, that is likely to result in increased CV morbidity and mortality, including greater target end organ damage as a result of vascular adaptations and concentric remodeling.

No description available.

<p> A key mechanism to maintain balance during walking is the foot placement strategy,  where the person steps in the direction of an impending fall. On a clear walkway, the foot  placement strategy translates to maintaining a consistent relationship between the center of mass  state and the base of support (a body-centric constraint on foot placement), which is reflected in  a consistent step length. However, to safely navigate in the community, foot placement must  maintain certain spatial relations with environmental features as well (environmental constraints on foot placement). For stepping over obstacles, the environmental constraint takes the form of  targeting. That is, the feet must be placed at precise locations relative to the obstacle to minimize  the likelihood of tripping.  My dissertation focused on proactive adaptations to foot placements while navigating  cluttered environments. I developed the interstep covariation (ISC) index that quantifies the covariation between consecutive foot placements relative to stationary, visible environmental  features (an obstacle and a visual target). The across-step (or group) changes in this index  indicate how the two constraints (body-centric and environmental) on foot placement are  managed during adaptive gait tasks. I quantified how the ISC index changed (1) across steps  while approaching and crossing an obstacle, (2) due to healthy aging and (3) when the proximity  of two environmental features was systematically altered. Specifically, in Study 1, the ISC index  was quantified for the obstacle crossing step for healthy younger and older adults. In Study 2, proactive changes in the ISC index as healthy young adults approached and crossed an obstacle were characterized. In Study 3, the changes in the dynamics of the across-step ISC index due to  an additional visual stepping target in the approach to the obstacle were identified.  I found that there exists a covariance strategy that healthy adults use to navigate the  environment safely and successfully. First, I found that individuals prioritize the environmental  constraint at the expense of the body-centric constraint when the environment poses a larger risk  to balance (the obstacle), or to satisfy a specified constraint (stepping on a visual target). Second,  I found that the shift in prioritization is proactive, i.e., it occurs while approaching an obstacle.  The strategy to shift priorities is influenced by age (Study 1), environmental features (Study 2  and Study 3), and the proximity of two environmental features (Study 3). These studies add to  the current understanding of foot placement control by demonstrating how this well-known and 15 fundamental strategy to maintain balance while walking is systematically influenced by the  environment and task constraints. These findings can be further extended to study proactive and  reactive adaptations during walking in different populations.   </p>

No description available.