Synthesis of dynamic systems

FORTRAN matrix analysis /FORMA/ program finds solutions of small and medium size structural dynamics problems of up to 150 deg of freedom

A study on the sintering of fine-grained diamond-SiC composites

Fine-grained diamond preforms (D[v, 0.9] = 2 μm) have been successfully infiltrated with silicon. The infiltration of fine-grained diamond preforms using silicon is limited by the blocking of the pores as a result of the volume increase during the reaction of diamond with Si to form SiC. The preforms were prepared using phenolic resin as a binder. In order to curb the problem of reaction chocking, the porosity of the preforms was increased by reducing the compaction pressure and the diamond particles were coated with SiC and TiC to delay the rate of reaction between diamond and silicon. With increasing resin content, the infiltration depth increases with up to 10 wt% resin content. A maximum infiltration (from the base of the preform) of 3.31mm was achieved for the uncoated diamond with 10wt% resin content and 3.71mm was achieved for SiCcoated diamond at 10wt% resin content. The infiltrated product is fully dense, exhibits high hardness and shows good abrasion wear properties comparable to that of Synda

Effects of a simulated slag phase on mixing and mass transfer rates in a creusot-loire uddeholm converter model

Student Number : 0318397E - MSc dissertation - School of Chemical and Metallurgical Engineering - Faculty of Engineering and the Built EnvironmentAn experimental study of the effects of a slag phase on mass transport in a onefifth water model of a 100ton CLU-converter was conducted. The study was a follow up to earlier investigations conducted in the absence of a simulated slag phase. Kerosene (10% by volume) was used to represent the slag phase in the cold model experiments. The presence of a slag phase increased the mixing time of a tracer solution in the bath. The mixing time, defined at 99.66% bath homogeneity, was found to increase with bath height and a lowering gas flow rate. The functional relationship, Tmix = 4.39Q-0.73W0.24H1.12, was established as expressing the effect of gas flow rate (Q), bath weight (W), and bath height (H) on the mixing time (Tmix). The mixing time increased by an average of 16.3% after slag inclusion. The mass transfer parameter [(Reloc,r)0.25(Ret)0.32] values obtained in the absence of a slag phase decreased by an average of 32.2% with slag inclusion. Calculated mass transfer coefficients increased with gas flow rate and a decrease in bath height. The relationship, K Q0.08, showing derived mass transfer coefficient (K) dependence on the gas flow rate (Q) was established. The proportionality constant in the equation was observed to vary with bath height, gas flow rate and sample location. Contour maps representing variation of mass transfer coefficients in the bath regions were produced

Local Community Participation in Rhino Conservation - Key to Conservation Success

A robust framework to guide community engagement in sustainable wildlife conservation and illegal wildlife trade is lacking. Virtually all conservation bodies and players believe that local communities are key to the success of rhino conservation but they are not equally walking their talk. Bottom-up community-based initiatives help to curb poaching especially level one poachers. The multifaceted problem of the African rhinoceros poaching on the continent is approaching calamitous proportions, with astounding, sobering statistics revealing the sheer extent of the illegal practice today. Poverty, greediness, superstition, rampant corruption, unchecked social injustice, ruthlessness, and ignorance are fuelling the interplay of rhino horn demand and supply. In order to save the remaining rhinoceros species there is need for economic transformation which will benefit both the communities and wildlife. Communities should get direct financial benefits from rhinoceros conservation, capacitate them and always engage them in rhinoceros conservation matters. Rhino protection should be incentivized, increasing the number of local people benefiting from conservation, and decreasing hostility towards wildlife will motivate local people to fully embrace conservation efforts. These conservation efforts should first target level one poachers who are vulnerable and exposed, by developing a comprehensive profitable and lucrative community participation packages in all rhino properties. Conservationists should walk their talk and genuinely work with local communities to build support for rhino conservation through education, awareness, self-sustaining business ventures and employment

Researching the dynamics of birth registration and social exclusion for child rights advocacy: the unique role of qualitative research

In response to the persistent problem of deficient birth registration, NGO-led coalitions in Zimbabwe are seeking to build a strong case for prioritizing universal birth registration. Beside efforts to amplify children's right to birth registration as defined in international rights conventions, these coalitions seek to construct a causal relationship between birth registration and social exclusion outcomes. The idea that the absence of birth registration intensifies social exclusion for children has become something of a mantra in birth registration activism, but despite the surveys conducted in Zimbabwe and other developing countries, data to demonstrate the dynamic interplay of birth registration and social exclusion are lacking. In this article I illustrate that qualitative research can bridge this gap and strengthen birth registration activism.Von NGOs geführte Koalitionen in Zimbabwe engagieren sich für eine deutliche Verbesserung der kontinuierlich defizitären Geburtenregistrierung. Neben dem Insistieren auf dem in internationalen Konventionen zugesicherten Recht wird hierzu eine kausale Beziehung zwischen Geburtenregistrierung einerseits und sozialer Exklusion bzw. Inklusion andererseits betont. Die Idee, eine fehlende Registrierung intensiviere soziale Exklusion ist zu einer Art Mantra der Aktivist/innen geworden, ihr fehlt aber eine empirische Fundierung: Trotz Surveys, die in Zimbabwe und anderen Entwicklungsländern erhoben werden, fehlen Erhebungen, die das dynamische Zusammenspiel von Geburtenregistrierung und Exklusion/Inklusion nachzuvollziehen erlauben würden. In diesem Beitrag versuche ich zu zeigen, in welcher Weise qualitative Sozialforschung helfen kann, diese Lücke zu schließen und die Aktivitäten in Richtung einer umfassenden Geburtenregistrierung zu stützen

The economic evaluation of aquaculture as a climate change adaptation option in fisher communities of Zimbabwe

Due to climate change, fisher households who depend on fishing for their livelihood are faced with a number of challenges that include low productivity. There is now an acknowledgement internationally that fishers cannot depend on hunting fish when all other food producing sectors have adapted. How economic and feasible is it for fishers to consider aquaculture in the face of climate change? This dissertation investigates the economic viability of aquaculture as a climate change adaptation option in rural fisher communities of Zimbabwe. The southern lowveld district of Mwenezi was used as a case study in the economic evaluation of pond culture and cage culture as a climate change adaptation strategy from a baseline position. Data was obtained from secondary sources which include the private sector involved in aquaculture, civil society organisations and the fishers practising aquaculture in both Mwenezi and another district, Kariba. The cost benefit analysis method of economic evaluation was used to assess the economic viability of pond and cage culture forms of aquaculture. The net present value, internal rate of return and benefit cost ratio were used as the decision criteria. Two scenarios were considered depending on the type of funding for the initial investment - scenario one was built on donor funding support while scenario two relied on a bank loan with interest for financing. A sensitivity analysis was also performed to determine the extent to which different factors affect the economic viability of both pond and cage culture. Both pond and cage culture were found to be economically viable as climate change adaptation options in fisher communities of Zimbabwe. Cage culture was found to have a higher net present value under both scenarios when compared to pond culture. However, under scenario two, pond culture was found to have a higher internal rate of return and benefit cost ratio. The inconsistencies were due to the variations in the scale of upfront investments between pond and cage culture where the latter requires a higher initial investment. Key factors that affect the viability of aquaculture as an adaptation strategy in Zimbabwe include the market price of fish, the cost of fish feeds and the price of fingerlings. While these factors are primarily economic, there are other factors which may affect the viability such as the increasing frequency of natural disasters

Implementation of Middleware for Internet of Things in Asset Tracking Applications: In-lining Approach

ThesisInternet of Things (IoT) is a concept that involves giving objects a digital identity and limited artificial intelligence, which helps the objects to be interactive, process data, make decisions, communicate and react to events virtually with minimum human intervention. IoT is intensified by advancements in hardware and software engineering and promises to close the gap that exists between the physical and digital worlds. IoT is paving ways to address complex phenomena, through designing and implementation of intelligent systems that can monitor phenomena, perform real-time data interpretation, react to events, and swiftly communicate observations. The primary goal of IoT is ubiquitous computing using wireless sensors and communication protocols such as Bluetooth, Wireless Fidelity (Wi-Fi), ZigBee and General Packet Radio Service (GPRS). Insecurity, of assets and lives, is a problem around the world. One application area of IoT is tracking and monitoring; it could therefore be used to solve asset insecurity. A preliminary investigation revealed that security systems in place at Central University of Technology, Free State (CUT) are disjointed; they do not instantaneously and intelligently conscientize security personnel about security breaches using real time messages. As a result, many assets have been stolen, particularly laptops. The main objective of this research was to prove that a real-life application built over a generic IoT architecture that innovatively and intelligently integrates: (1) wireless sensors; (2) radio frequency identification (RFID) tags and readers; (3) fingerprint readers; and (4) mobile phones, can be used to dispel laptop theft. To achieve this, the researcher developed a system, using the heterogeneous devices mentioned above and a middleware that harnessed their unique capabilities to bring out the full potential of IoT in intelligently curbing laptop theft. The resulting system has the ability to: (1) monitor the presence of a laptop using RFID reader that pro-actively interrogates a passive tag attached to the laptop; (2) detect unauthorized removal of a laptop under monitoring; (3) instantly communicate security violations via cell phones; and (4) use Windows location sensors to track the position of a laptop using Googlemaps. The system also manages administrative tasks such as laptop registration, assignment and withdrawal which used to be handled manually. Experiments conducted using the resulting system prototype proved the hypothesis outlined for this research

A methodological approach and conceptual tools for studying migrant belongings in African cities: a case of Zimbabweans in Johannesburg

Many scholars view the relaxation of restrictions to enter and reside in South Africa after the end of apartheid in 1994 as a catalyst for a number of changes in regional human migration. In this article,I show that human migration dynamics in post-apartheid South Africa pose theoretical and methodological challenges for studies of belonging among migrants. I argue that the majority of studies of belonging among migrants in South Africa rely on nation-state frames of reference and quantitative approaches. Furthermore, they largely seek to establish general patterns of migration processes. While these studies illuminate macro-level factors which seemingly structure migration experiences, they provide only a partial picture of migration dynamics. Often, they fail to sufficiently attend to contextdependent modes of emplacement among migrants in the urban zones due to the conceptual and methodological tools they use. The purpose of this article, therefore, is to suggest theoretical assumptions, concepts and methodological tools which constitute an alternative design for studying social constructions and practices of belonging among migrants in post-apartheid South Africa. The article draws on my doctoral research of Zimbabweans in Johannesburg for illustrations

The Field Experience: An Internship at Lake Land College

No abstract provided by author