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This work examines a novel concept and design of simultaneous energy harvesting and vibration control on the same host structure. The motivating application is a multifunctional composite sandwich wing spar for a small Unmanned Aerial Vehicle (UAV) with the goal of providing self-contained gust alleviation. The basic idea is that the wing itself is able to harvest energy from the ambient vibrations along with available sunlight during normal flight. If the wing experiences any strong wind gust, it will sense the increased vibration levels and provide vibration control to maintain its stability. This work holds promise for improving performance of small UAVs in wind gusts. The proposed multifunctional wing spar integrates a flexible solar cell array, flexible piezoelectric wafers, a thin film battery and an electronic module into a composite sandwich structure. The basic design factors are discussed for a beam-like multifunctional wing spar with load-bearing energy harvesting, strain sensing and self-controlling functions. Three-point bending tests are performed on the composite sandwich structure for bending strength analysis and bending stiffness prediction under a given safety factor. Additional design factors such as the configuration, location and actuation type of each piezoelectric transducer are investigated for optimal power generation. The equivalent electromechanical representations of a multifunctional wing spar is derived theoretically, simulated numerically and validated experimentally. Special attention is given to the development of a reduced energy control (REC) law, aiming to minimize the actuation energy and the dissipated heat. The REC law integrates a nonlinear switching algorithm with a positive strain feedback controller, and is represented by a positive feedback operation amplifier (op-amp) and a voltage buffer op-amp for each mode. Experimental results exhibit that the use of nonlinear REC law requires 67.3 % less power than a conventional nonlinear controller to have the same settling time under free vibrations. Nonlinearity in the electromechanical coupling coefficient of the piezoelectric transducer is also observed, arising from the piezoelectric hysteresis in the constitutive equations coupling the strain field and the electric field. If a constant and voltage-independent electromechanical coupling coefficient is assumed, this nonlinearity results in considerable discrepancies between experimental measurements and simulation results. The voltage-dependent coupling coefficient function is identified experimentally, and a real time adaptive control algorithm is developed to account for the nonlinear coupling behavior, allowing for more accurate numerical simulations. Experimental validations build upon recent advances in harvester, sensor and actuator technology that have resulted in thin, light-weight multilayered composite sandwich wing spars. These multifunctional wing spars are designed and validated to able to alleviate wind gust of small UAVs using the harvested energy. Experimental results are presented for cantilever wing spars with micro-fiber composite transducers controlled by reduced energy controllers with a focus on two vibration modes. A reduction of 11dB and 7dB is obtained for the first and the second mode using the harvested ambient energy. This work demonstrates the use of reduced energy control laws for solving gust alleviation problems in small UAVs, provides the experimental verification details, and focuses on applications to autonomous light-weight aerospace systems. / Ph. D.

Submitted in accordance with the requirements for the degree of Doctor of Philosophy in Library and Information Science at the University of Zululand, South Africa, 2012. / The use of tools for development has evolved from the industrial revolution in the late 18th and 19th centuries that saw the increased use of machines and developments in the mining industries, to the increased use of information and technology in the 20th century and major breakthroughs that sparked the evolution into the information and knowledge society of the 21st century. The basis of the information and knowledge society revolves around technology’s increased assimilation and diffusion in human society, particularly information and communication technologies and their rapid growth and use in the exchange of information and knowledge. This society offers many opportunities and benefits to people in terms of the facilitation of information creation, distribution, diffusion, access and use for growth and development in various spheres of life. Information and communication technologies are thus regarded as tools for the advancement and development of communities, and this includes rural, illiterate, marginalized and poor communities and the female entrepreneurs in the informal sector who are the subject of this thesis. The aim of this study was to examine information and knowledge society and its impact on poverty alleviation and the economic empowerment of informal sector women entrepreneurs in South Africa and develop a model for utilization of information and knowledge in the informal sector. Both qualitative and quantitative approaches were employed for triangulation, although the qualitative approach significantly outweighed the quantitative in this study. The absence of a comprehensive list of informal activities in KwaZulu-Natal led to the decision to use snowball, purposive and haphazard sampling techniques to select the sample for the study. Focus group discussions, interviews, observation and content analysis were used to collect data from 118 women entrepreneurs from the informal sector, 17 women leaders, and 4 officials from the Hlabisa Local Municipality in KwaZulu-Natal.

Poverty alleviation is a key item on the agenda of both government and non-governmental organisations. The use of indigenous knowledge to embark on small and medium size enterprises (SMEs) such as handicraft making has shown that it has a potential to yield the desired outcome in many areas. The research addressed the question: to what degree are handicrafts made in the Lowveld region of Swaziland and to what extent do these handicrafts contribute towards the livelihood of rural households? The data was collected using questionnaires and observations. Findings revealed that the production of handicrafts is the second most important livelihood activity for most respondents. Even though the income received from these activities is small, its significance lies in the timing at which it is received; and on its role in supporting existing livelihood activities. Sustainability of the business is, however, threatened by inaccessibility of resources, lack of organisation and trading challenges There is a need to promote the cultivation of natural resources, continuous training workshops and for women to form cooperatives or groups. Further research is needed that would focus on the following areas: a comparative study done in urban areas which shall also investigate the impact of handicraft on urban poor households; a study which will focus on handicraft marketing and consumption and lastly on the youth and handicraft. / Agriculture, Animal Health and Human Ecology / M.Sc. (Human Ecology)

The study of the motion of manoeuvring aircraft has traditionally considered the aircraft to be rigid. This simplifying assumption has been shown to give quite accurate results for the flight dynamics of many aircraft types. As modern transport aircraft have developed however, there has been a marked increase in the size and weight of these aircraft. This trend is likely to continue with the development of future blended-wing-body and supersonic transport aircraft. This increase in size and weight has brought about a unique set of aeroelastic and handling quality issues. The aerodynamic forces and moments acting on an aeroplane have traditionally been represented using the aerodynamic derivative approach. It has been shown that this quasisteady aerodynamic model inadequately predicts the aircraft’s stability characteristics, and that the inclusion of unsteady aerodynamics “greatly improves the fidelity” of aircraft models. This thesis thus presents a novel numerical simulation of an aeroelastic aeroplane for real-time analysis. The model is built around the standard six degree-of-freedom equations of motion for a rigid aeroplane using the mean-axes system, and includes unsteady aerodynamics and structural dynamics. This is suitable for pilot-in-the-loop simulation, handling qualities and flight loads analysis, and control law development. The dynamics of the structure are modelled as a set of normal modes, and the equations of motion are realised in state-space form. The unsteady aerodynamic forces acting on the aeroplane are described by an indicial state-space model, including unsteady tailplane downwash and compressibility effects. An implementation of the model is presented in the MATLAB/ Simulink environment. The interaction between the flight control system, the aeroelastic system and the rigidbody motion of the aeroplane can result in degraded handling qualities, excessive actuator control, and fatigue problems. The introduction of load alleviation systems for the management of loads due to manoeuvres and gusts is also likely to result in the handling qualities of the aeroplane being degraded. This thesis presents a number of studies into the impact of structural dynamics, unsteady aerodynamics, and load alleviation on the handling qualities of a flexible civil transport aeroplane. The handling qualities of the aeroplane are assessed against a number of different handling qualities criteria and flying specifications, including the Neal-Smith, Bandwidth, and CAP criterion. It is shown that aeroelastic effects alter the longitudinal and lateral-directional characteristics of the aeroplane, resulting in degraded handling qualities. Manoeuvre and gust load alleviation are similarly found to degrade handling qualities, while active mode control is shown to offer the possibility of improved handling qualities.

Income generating projects represent one strategy adopted by the Department of Social Development to alleviate poverty and foster sustainable development. The purpose of this study was to investigate the perceptions of beneficiaries of income generating projects regarding these projects and whether the income generating projects run by the Development Centres in the Sedibeng Region, Gauteng Department of Social Development were perceived to be making any impact and were responding to the needs of the poor. The research design for the study could be classified as qualitativedescriptive. A sample of 20 participants was drawn from two Development Centres. The sampling method for the study was partly purposive and partly availability sampling. Data were collected via semi-structured interviews and responses obtained from the interviews were analyzed using descriptive statistics and thematic content analysis. The main findings that emerged from the study were that participants appeared to have a clear understanding of the fact that income generating projects represented a government strategy to fight poverty, create jobs and uplift the standard of living of the poor. However, most participants were dissatisfied with the lack of clearly defined expectations, planning and monitoring on the part of the Department of Social Development. Despite the fact that there were challenges and limitations encountered by beneficiaries during implementation of the projects, the Development Centre was perceived to be an effective service delivery model for alleviating poverty and enhancing the quality of life of beneficiaries. The conclusion drawn was that income generating projects conducted at the two Development Centres seemed to be achieving their aims even though there would seem to be room for improvement in terms of knowledge and skills imparted and participation of beneficiaries in decision-making. These findings are discussed in terms of their implications for Development Centres, the Department of Social Development, social work practice and future research.

Thesis (M. Dev.) -- University of Limpopo, 2002

Thesis (M.Dev.) --University of Limpopo, 2013 / The research study investigated the contribution of community development projects towards poverty alleviation in Thulamela Local Municipality of Limpopo province. This research study seeks to investigate the factors that hinder community development projects from contributing positively towards the improvement of the lives of rural communities in the area of the study. This study is also concerned with the development of effective strategies that will enhance the capacity of community development project managers and change their perception and that of other stakeholders with regard to the implementation of community development projects. The literature review established the relationship between community development project and project management. In this regard, the study showed that community projects run by project managers with proper knowledge of and skills in project management impact positively on the improvement of the lives of the rural communities. In this study, a mixed research design approach was used in the investigation of the factors that hinder community projects to contribute positively towards poverty alleviation in Thulamela Local Municipality. Questionnaires and structured interviews were used to collect data from the target population. The findings of the study suggest that most managers of the community development projects lack training in project management.They also revealed that there were inadequate resources; there is a lack of community participation in decision-making, and shortage of funds hampered the sustainability of community development projects. To conclude, it is expected that the recommendations of this research study will highlight the strategies that could be put in place to improve the management of community development projects in order to improve the livelihoods of people in the Thulamela Local Municipality.

The study of the motion of manoeuvring aircraft has traditionally considered the aircraft to be rigid. This simplifying assumption has been shown to give quite accurate results for the flight dynamics of many aircraft types. As modern transport aircraft have developed however, there has been a marked increase in the size and weight of these aircraft. This trend is likely to continue with the development of future blended-wing-body and supersonic transport aircraft. This increase in size and weight has brought about a unique set of aeroelastic and handling quality issues. The aerodynamic forces and moments acting on an aeroplane have traditionally been represented using the aerodynamic derivative approach. It has been shown that this quasisteady aerodynamic model inadequately predicts the aircraft’s stability characteristics, and that the inclusion of unsteady aerodynamics “greatly improves the fidelity” of aircraft models. This thesis thus presents a novel numerical simulation of an aeroelastic aeroplane for real-time analysis. The model is built around the standard six degree-of-freedom equations of motion for a rigid aeroplane using the mean-axes system, and includes unsteady aerodynamics and structural dynamics. This is suitable for pilot-in-the-loop simulation, handling qualities and flight loads analysis, and control law development. The dynamics of the structure are modelled as a set of normal modes, and the equations of motion are realised in state-space form. The unsteady aerodynamic forces acting on the aeroplane are described by an indicial state-space model, including unsteady tailplane downwash and compressibility effects. An implementation of the model is presented in the MATLAB/ Simulink environment. The interaction between the flight control system, the aeroelastic system and the rigidbody motion of the aeroplane can result in degraded handling qualities, excessive actuator control, and fatigue problems. The introduction of load alleviation systems for the management of loads due to manoeuvres and gusts is also likely to result in the handling qualities of the aeroplane being degraded. This thesis presents a number of studies into the impact of structural dynamics, unsteady aerodynamics, and load alleviation on the handling qualities of a flexible civil transport aeroplane. The handling qualities of the aeroplane are assessed against a number of different handling qualities criteria and flying specifications, including the Neal-Smith, Bandwidth, and CAP criterion. It is shown that aeroelastic effects alter the longitudinal and lateral-directional characteristics of the aeroplane, resulting in degraded handling qualities. Manoeuvre and gust load alleviation are similarly found to degrade handling qualities, while active mode control is shown to offer the possibility of improved handling qualities.