A new robotic leg design is presented that utilizes dielectric elastomers (3M VHB 4910) to rapidly control stiffness changes for enhanced mobility and agility of a field demonstrated hexapod robot. It has been shown that stiffness changes of electro-active membranes made of dielectric elastomers can overcome challenges with other polymer materials that use heat to create modulus and stiffness changes. Applied electric fields eliminate issues with thermal transport rates and thermo-mechanical delaminatation. The dielectric elastomer is characterized uniaxially to understand its hyperelastic and viscoelastic properties. The uniaxial data is fit to a hyperelastic and viscoelastic finite deformation model. The material is then pre-stretched biaxially to stretch ratios ranging from 200%, 300% and 400%. A set of electro-mechanical transverse load experiments are then utilized to obtain up to 92% reduction in stiffness that is controlled by an electric field. The results are compared to a finite deformation membrane finite element model to understand and improve field driven stiffness changes for real-time robotic applications. / A Thesis submitted to the Department of Mechanical Engineering in partial fulfillment of the requirements for the degree of Master of Science. / Spring Semester, 2012. / March 30, 2012. / bio-inspired, biomimetic, Dielectric elastomer, VHB / Includes bibliographical references. / William S. Oates, Professor Directing Thesis; Emmanuel Collins, Committee Member; Jonathan Clark, Committee Member; Peter N. Kalu, Committee Member.

The purpose of this inquiry was to describe and understand the lived experiences of the acculturative process of the Indonesian graduate students at an American public university. The primary focus here was on better understanding how some events or changes become sources of difficulties, problems, or culture shock in Indonesian graduate students' lives. The purpose of this study could be depicted in three ways: (1) to describe the lived experiences of Indonesian graduate students in relation to their academic matters and social relations during their acculturative process during the first term and over time at their institution, (2) to understand or to explore the major sources of acculturative problems or the causes of cultural shock leading to acculturative stress experienced by Indonesian graduate students, and (3) to understand how Indonesian graduate students have dealt with those acculturative problems or stressors and what the acculturative strategies that they have used to cope with acculturative problems or stressors with respect to academic matters and social relations at the first term and over time at their institutions. The theoretical frameworks of Oberg's (1960) culture shock model and Berry's (1987, 2006) acculturation stress model were used to guide this study. Data for this study were collected through a demographic background survey, in-depth interviews, and focus group discussions with thirteen Indonesian graduate students. The demographic data were analyzed descriptively. The interviews and focus groups data were analyzed by using within-case and cross-case displays and analyses (Miles & Huberman, 1994). Four salient themes with their sub-themes to emerge were: academic shock, adjustment, crisis, and resolution. Implications and strategies for professionals and scholars who work with international students in practice, education and policy are discussed. In addition, strategies to promote Indonesian graduate students' academic and social success in graduate programs are included. Suggestions for future research are also discussed. / A Dissertation submitted to the Department of Educational Leadership and Policy Studies in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Spring Semester, 2012. / December 6, 2011. / Educational policy, Higher education, Indonesian graduate student, Indonesian student, International student, Multicultural education / Includes bibliographical references. / Jeffrey Ayala Milligan, Professor Directing Dissertation; Stephen D. McDowell, University Representative; Stacey Rutledge, Committee Member; Peter Easton, Committee Member.

Saxophonists aspiring to perform significant classical repertoire will quickly discover the challenges of high register passages in the third and fourth registers. Many of the early saxophone concerti, namely those composed between 1930-1960, are the foundation of the saxophone's solo repertoire, and have guided composers and performers alike to explore the capabilities of the instrument in this regard. All saxophonists face the great task of representing these works with the artistic integrity their composers intended and can therefore benefit from an anthology that contains selected high register passages in their correct context, unaltered by unorthodox performance practice, subjective reasoning, or publication error. This treatise examines high register passages from the alto saxophone concerti of Lars-Erik Larsson, Jacques Ibert, Frank Martin, Henry Brant, Carl Anton Wirth, Ingolf Dahl, Erland von Koch, and Frank Erickson. Historical and analytical facts regarding each composer and work are given, and the included concerti are taken from the most current published editions available. / A Treatise submitted to the College of Music in partial fulfillment of the requirements for the degree of Doctor of Music. / Summer Semester, 2012. / May 18, 2012. / concerto, ibert, larsson, muller, rascher, saxophone / Includes bibliographical references. / Patrick Meighan, Professor Directing Treatise; Seth Beckman, University Representative; Eric Ohlsson, Committee Member; John Parks, Committee Member.

Vortex-Induced Vibration (VIV) in cables is a prevalent phenomenon affecting the structural health of bridges and their components. Past studies have shown both passive and active methods are beneficial in the reduction of vibrations, however, a number of issues such as excessive base moment, transformation of geometry, intrusive implementation and fatigue limit the effectiveness of current engineering. A method involving no intrusion, no geometrical manipulation and a mechanism to prevent and mitigate VIV is needed. A "skin" of material embedded with Macro-Fiber Composite (MFC) material and with the capabilities of perturbing the surface near the separation point of vortex shedding is explored and tested. Simplifications of the proposed material are made in order to understand the effects of the capabilities of a perturbing skin of MFC material. Construction of a 17-ft Open-circuit wind tunnel is done in order to make the VIV condition to be tested with the near method of VIV control. The VIV on cables is recorded. Experiments are run inside the tunnel at a Re of 11400 and 6400. In order to see the effects of surface perturbations, an MFC actuation mechanism is made and a cable section effectively able to cause surface perturbations is built. A test is then run to find the effect of different angles of perturbation. Finally, a testing and analysis of a phase-difference of a signal, at prescribed perturbation frequencies is done. This is analyzed against surface vortex formation theory. The data are analyzed in order to see the capabilities of an MFC skin on VIV of cables. The mechanism shows promise in both reducing VIV and providing for a low-key, non-intrusive control mechanism. / A Thesis submitted to the Department of Civil and Environmental Engineering in partial fulfillment of the requirements for the degree of Master of Science. / Spring Semester, 2012. / March 30, 2012. / Control, Frequency, Response, Structural Health, Vibration, Vortex / Includes bibliographical references. / Sungmoon Jung, Professor Directing Thesis; Michelle Rambo-Roddenberry, Committee Member; Lisa K. Spainhour, Committee Member.

The purpose of my dissertation is to study the impact of delayed childbearing on the motherhood wage penalty. Independently, both delayed childbearing and the motherhood wage penalty have been well documented in academic studies. However there has been a lack of research on these two topics together. Therefore this study will look to see if delaying the birth of a first child leads to a woman receiving a lower wage penalty. I will look for differences in the effect of delaying childbearing in different race groups, compare the effect of a second child, and the spacing of the first and second child. This study will use the NLSY 79, to study the effect of delayed childbearing on the motherhood wage penalty. This will allow for the study to include both a panel data approach and a cross sectional approach. There will be five general models used. The first two, OLS and fixed effects model, have been used in the majority of the wage penalty papers. The third model type, a selection model, has recently begun to be used more in wage penalty papers. This model will allow for the inclusion of women who are currently not employed into the model instead of dropping them from the sample. The fourth model, an instrumental variable model, instruments for age at first birth with naturally occurring birthing shocks. The last model, the double selection model, takes into account the selection into motherhood and employment simultaneously. This dissertation uses the same data set to study the motherhood wage penalty and the affect of timing on it. The first three chapters introduce the previous literature and the data. Chapter 4 studies the motherhood wage penalty. The models used are Ordinary Least Squares (OLS), Fixed Effects, and Selection model. All of the models are run for all women as well as be run with white and black women separately. The results show that women do face a significant wage penalty even when controlling for difference between women. The next section (chapter 5) studies the effect of timing on the motherhood wage penalty. This means that only mothers are included in this section because she had to have given birth in order to have an age at first birth. By adding an age at first birth variable, the wage premium for delayed childbearing can be measured. This section adds an Instrumental Variable model along with the OLS and Selection models. These models again show that there is a wage penalty present along with a premium for delayed childbearing. Chapter 6 introduces birth spacing into the model. This means that all women in this section had at least two children. The birth spacing models include OLS, Selection, and IV models. The results show that there is a wage penalty for having three or more children and premium for delayed childbearing. The is also a positive coefficient estimate on the time between births, so when a women spreads her births out more she receives a higher wage. Chapter 7 uses a double selection model to estimate the wage penalty for having children and the premium for delaying childbearing. The model includes a selection term for employment, like in the previous chapters, and a selection term for motherhood. The model has a significant wage penalty and wage premiums. This section also breaks down the model by level of education. This showed that there are larger difference in the wage penalty between different levels of education. / A Dissertation submitted to the Department of Economics in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester, 2011. / October 12, 2011. / Motherhood, penaly, wage / Includes bibliographical references. / Carl Schmertmann, Professor Directing Dissertation; Elwood Carlson, University Representative; Karin Brewster, Committee Member; Thomas Zuehlke, Committee Member.

Meiosis is the process by which sexually reproducing organisms reduce their genomes from diploid (2n) to haploid (n) during the formation of gametes. It requires that homologous chromosomes pair, synapse, recombine, and finally segregate. These widely conserved processes are under genetic control, yet the exact details of many of the underlying molecular mechanisms remain under active investigation. The initial pairing and subsequent synapsis events are immediately preceded by the clustering of telomeres on the nuclear envelope in a widely conserved structure referred to as the bouquet arrangement of meiotic chromosomes. In animals and plants, genes required for genome reduction at meiosis I have been characterized and show a high degree of conservation between kingdoms and species within them. Higher plants (most notably maize) have provided an excellent large-genome model system for the study of the cytology of homologous chromosome behavior and therefore have allowed an in depth dissection of the meiotic process in eukaryotes. At the cellular level, meiotic chromosome behavior is accompanied by changes in the architecture of the cell nucleus, particularly with respect to the interaction of telomeres with the nuclear periphery. This dissertation presents the work involving the analysis of a classic meiotic mutant of maize, desynaptic (dy1). The dy1 mutant is characterized by a precocious telomere-nuclear envelope detachment phenotype at mid prophase, resulting in chromosome breaks, anaphase bridges, micronuclei, and defective pollen development. In this study, we observed new phenotypes as early as the telomere bouquet stage of meiotic prophase in dy1 lines of maize. Using linkage and translocation mapping techniques, the dy1 mutation was mapped to the long arm of chromosome 3, where a candidate gene with homology to a nuclear envelope-associated SUN domain protein gene was identified. SUN (Sad1p/Unc-84) domain proteins function with other proteins to form a physical link between the nucleoskeleton and the cytoskeleton. These bridges transfer forces across the nuclear envelope and are increasingly recognized to play roles in nuclear positioning, nuclear migration, cell cycle-dependent breakdown and reformation of the nuclear envelope, telomere-led nuclear reorganization during meiosis, and karyogamy. Using bioinformatic and molecular approaches, we characterized the family of maize SUN-domain proteins, starting with a screen of maize genomic sequence data. We characterized five different maize ZmSUN genes (ZmSUN1-5), which fell into two structural classes likely of ancient origin. Orthologs of these genes and prevalent in the plant kingdom as they are also found in other monocots, eudicots, and even mosses. The first class described here designated canonical C-terminal SUN-domain (CCSD, ZmSUN1 and ZmSUN2), includes structural homologs of the animal and fungal SUN-domain protein genes. The second class, the plant-prevalent mid-SUN 3 transmembrane (PM3, ZmSUN3-5), includes a novel but conserved structural variant SUN-domain protein gene class. Analysis of the expression levels for these genes revealed very low expression in multiple tissue types, with the exception of ZmSUN5 which showed a pollen=preferred expression profile. Cloning and Peptide antibodies specific for ZmSUN3, and ZmSUN4 were used in western-blot and cell-staining assays to show that they are expressed and show concentrated staining at the nuclear periphery. In order to characterize the CCSD class of SUNproteins, we obtained new reagents and performed immunolocalization analyses coupled with high resolution 3D deconvolution microscopy. We identified a novel structure at the maize nuclear periphery we refer to as the "Nuclear SUN Belt", NSB, which was present in multiple somatic cell types as well as meiotic nuclei. During meiosis, the NSB was present at the onset and well into the leptotene stage of meiotic prophase. Surprisingly at the bouquet stage the NSB appeared to be localized opposite of the nucleolus in a crescent shape, occupying a small region (<1/3) of the surface of the nuclear periphery, often co-localizing with meiotic telomeres. During late prophase, the NSB returned temporarily until the release of the telomeres from the NE and subsequent NE breakdown prior to metaphase. The NSB later returned in post-meiotic nuclei including uninucleate cells, and prophase II nuclei. Using peptide antibodies specific for the CCSD class, we detected a severe disruption of SUN proteins at the nuclear envelope in a line of maize defective in meiotic telomere tethering and chromosome synapsis (desynaptic1, dy1) as well as a line defective in the transition from a prophase microtubule array to a metaphase spindle (divergent1, dv1) (SHAMINA et al. 2000b; STAIGER and CANDE 1990a). The findings presented in this dissertation provide valuable new information regarding the spatial distribution and dynamics of maize SUN proteins at the NE and for an initial interpretation of the phenotypes of historical meiotic mutants of maize. / A Dissertation submitted to the Institute of Molecular Biophysics in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester, 2011. / October 4, 2011. / Bouquet, Maize, Meiosis, nuclear envelope, Sad1/Unc-84, telomeres / Includes bibliographical references. / Hank Henry W. Bass, Professor Directing Dissertation; Myra M. Hurt, University Representative; James Fadool, Committee Member; Hong Li, Committee Member; Lloyd Epstein, Committee Member.

Thesis: S.M. in Management Research, Massachusetts Institute of Technology, Sloan School of Management, 2017. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 38-42). / Using survey data from China, I examine how migrant workers respond to violations of labor law in their workplaces. The central puzzle explored is why, given apparent widespread violations, some workers choose not to pursue remedies. I find that workers with shared local identities with their employers are less likely to be exposed to safety and health hazards at work, less likely to have employment contracts, and less likely to interpret problems experienced as a violation of their legal rights. This paper extends the research on grievance behavior by drawing on research from Law and Society and social networks to understand how these subjective interpretation processes and social identities outside of work influence grievance behaviors. While the empirical focus is on China, the theoretical extensions may help explain why workers in other settings fail to express grievances when confronted with workplace violations. / by Duanyi Yang. / S.M. in Management Research

Thesis (MEng (Chemical Engineering))--Cape Peninsula University of Technology, 2020 / Reactive dye waste effluents are the most difficult to treat, as they are highly polluted due to the structure of the dyestuffs and chemicals used during the dyeing process. Due to the water shortage and environmental pollution, textile industries are encouraged to treat the waste effluent produced during dyeing processes so as to facilitate its reuse, as this will contribute to mitigating environmental pollution and minimise water consumption. However, relatively few of the treatment technologies employed for the treatment of textile wastewater are applicable for water that is intended for reuse. Many treatment technologies exist for the treatment of textile waste effluents, but are either limited in efficiency or high in operating and energy cost. Chemical treatment methods such as the cobalt oxide mediated sulphate radical-based advanced oxidation process (CO-SR-AOP) shows promise but have not yet been evaluated for the reuse of textile wastewater in the dyeing process. The purpose of this work is to study the reusability of a treated reactive dye effluent obtained from dyeing cotton fabrics using peroxymonosulfate (PMS) activated by a cobalt oxide (Co3O4) catalyst and using a laboratory-scale continuous wastewater treatment reactor. In order to achieve this, a cobalt oxide catalyst was hydrothermally synthesised, cotton fabrics were bleached as pre-treatment prior to being dyed using blue reactive dye and tap water to produce the necessary textile waste effluent. The produced waste effluent was treated with Oxone (PMS) and a cobalt oxide catalyst; then reused in the next dyeing process, using an identical dyeing recipe. The pH of the treated effluent was corrected to neutral before its reuse. The waste effluent from the first cycle of dyeing was treated before its next reuse. This process was carried out for a maximum of three cycles. The dyed fabrics obtained using the treated effluent were compared with the ones dyed with tap water in terms of colour fastness. The optimisation of the reusability of a treated effluent from cobalt oxide and sulphate radical-based advanced oxidation process was carried out using Design-Expert software version 11.1.2.0 using a Box-Behnken design taken from response surface methodology. The effects of three factors were studied: Oxone level, dye concentration and reuse cycles at low, high and medium levels in fifteen experimental runs. Colour fastness of the dyed fabrics was studied as the response of the trials. Based on the preliminary results, the treated effluent can be reused in two successive reuse cycles without altering the fabric’s quality. To obtain more or less 80% colour removal, waste effluent with 3% dye concentration must be obtained and treated with a high dosage of Oxone (3.5 g/l). Salt can be recovered by using this process, but with a darker shade of dyed fabric as a result, when compared with the reference. Varying dilution factors and standing times of the treated effluent were investigated but did not have significant influence on the colour quality of the dyed fabrics. A useful model was found to predict the colour fastness of dyed fabrics with an effluent treated with the continuous wastewater treatment reactor system using PMS activated by Co 3 O 4 . The study of the interaction effects of all three parameters led to the finding that to obtain good colour fastness grading of the dyed fabrics, the treated effluent can be reused a maximum of two iterations, with a dye concentration of 5% and an Oxone concentration of 1 g/L. The predicted optimum process conditions for this process were 1.3 g/l of Oxone used to treat a waste effluent with 4.4% dye concentration and reuse in a maximum of three reuse cycles.

Thesis (MTech (Business Administration))--Cape Peninsula University of Technology, 2020 / This thesis examined the impact skills shortage among artisans in the heating, ventilation and air conditioning (HVAC) field have on the industry. The rationale for this investigation is based on the view of engineers and company owners in the HVAC industry that there is a dire need to train more artisans and to improving the skills of already qualified artisans. The thesis employed a mixed method research approach and reviewed relevant literature. Empirical data was obtained from HVAC contracting companies being members of the South African Refrigeration and Air Conditioning Contractors Association (SARACCA) in the Western Cape. The study demonstrates that there is a shortage of skilled and qualified artisans in the HVAC industry. Although there are individuals within the HVAC industry who are passionate about training, their efforts cannot supply the whole industry with knowledgeable qualified artisans. More emphasis should be placed on basic education, the level of artisan training, continuous training of qualified artisans and the retention of skilled artisans. Based on the findings, the study concluded that skilled artisans and poor quality workmanship is being experienced on a continuous basis. The lack of skilled artisans and the cost implication to obtain skilled artisans force companies to employ unskilled labour. It is recommended that the industry should work closer with government agencies to ensure that training being offered by private training institutions and colleges is aligned with the industry requirements. This together with an improved education system will secure skilled artisans.

Thesis (MTech (Tourism and Hospitality Management))--Cape Peninsula University of Technology, 2020 / Coastal and Marine Tourism (CMT) is a sector which continues to draw visitors from different countries to South Africa. This is attributable to the long coastline and abundance of marine wildlife found in South African waters. Despite the strong interest in visiting South Africa’s marine environment, there is limited information on the economic contribution of CMT in South Africa. Shark cage diving offered in Gansbaai, Western Cape, South Africa draws a large number of visitors globally, thereby providing benefits to visiting tourists and socio-economic benefits to the area. This study focuses on determining the profile of visitors who engage in shark cage diving in Gansbaai and expenditure patterns related to shark cage diving in respect of the Gansbaai economy, as well as the role that shark cage diving plays in tourists’ (domestic and international) decisions to visit South Africa. The study applied a quantitative research approach, with self-administered survey questionnaires (face to face) distributed to visitors after a shark cage diving experience in Gansbaai. A proportionate sampling approach was adopted for the study; this sampling method was suited to this research as it excluded locals from the sampling, thus randomly selecting visitors from outside the Gansbaai region. In total, 378 survey questionnaires were collected, analysed and interpreted. In terms of profiling, the study revealed that the majority of visitors participating in shark cage diving in Gansbaai are international visitors, with a reasonable disposable income, as the activity proved costly. Of these international visitors, the majority were day visitors to Gansbaai, thus restricting spending in the area. With regard to expenditure patterns, the relatively few overnight visits to Gansbaai make it difficult to exploit the maximum socio-economic benefits associated with shark cage diving, as the local economy is heavily dependent on this activity. Furthermore, the study also revealed that shark cage diving in Gansbaai was a factor in international visitors’ decisions to visit South Africa, with the activity not holding as much attraction for South Africans. As the study uncovered an interest in marine-based activities and a growing appeal in nature-based activities, it recommends that the development of a more diverse offering in Gansbaai will contribute to greater economic spend in the area. This has the potential to appeal to the domestic market to participate in shark cage diving. Package tours and discounted prices for domestic visitors could assist in highlighting other attractions in the Gansbaai region and increase domestic participation in such activities. These package tours will in return encourage economic activity in the area which will result in greater expenditure by visitors. Further studies on this activity are underscored as a lack of understanding may have serious implications for tourists, tourism in the area, tourism destination planners, tour operators, and tourism establishments in Gansbaai.