The development of miniaturized technologies has become a global phenomenon that continues to make an impact across a broad range of applications that encompasses many diverse fields and industries including telecommunications, portable consumer electronics, defense, and biomedical. Subsequently this trend has caused more and more interest in the issues involved in the design, development, operation and analysis of equipment and processes for manufacturing micro components. One technology used to create these miniaturized components is micro end milling. The cutting forces of the micro end milling process provide vital information for the design, modeling, and control of the machining process. To gain an understanding of forces in micro end milling operations, a model of average chip thickness is derived and the differences between conventional end milling and micro end milling are enumerated. From the experimental results, empirical models for specific cutting constants were derived and compared the generally accepted forms for conventional end milling operations. These models provide a tool for the estimation of cutting forces in micro end milling.

<p>On one side Innovation, innovation systems and knowledge management are two topics have been discussed so much by scholars before. The advantages gained through knowledge management by fostering innovation which entails competitive advantage. On the other side, an emerging interest has represented the relationship between the renewable industry and environmental innovations. The oil crises and some forum discussion of environmental impact have fuelled the interest for Renewable Energy especially on wind energy. Most likely there hasn’t been any research knowledge management in wind power companies which is an emerging and terribly needs knowledge to innovate and bring more products. As a result there is a need to look more into the role of knowledge management in wind mill companies and explore how innovation can be triggered by successful knowledge management and how this process provide competitive advantage in wind power industry.</p><p><strong> </strong></p>

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This work is an in depth reflection on my rehearsal process in the final performance of my graduate career as Esther Mills in Intimate Apparel by Lynn Nottage. In addition to my work in the aforementioned show, I assess my entire experience as an MFA candidate in acting at the University of Texas at Austin in the Department of Theatre and Dance. / text

Artefacts relating to tin smelting from tin mills or 'blowing houses' in Devon and Cornwall, plus material from smelting sites that cover a range of dates from the Bronze Age through to the 19th Century, were examined: these include metallic tin, furnace linings, ore samples and slag. Analysis of tin slags from over forty sites was carried out, to determine microstructure and chemical composition. Techniques employed included optical and scanning electron microscopy, X-ray fluorescence and ICP mass spectrometry. Analysis indicates that slag appearance and composition are heavily influenced by local geology. Composition, particularly iron content, is shown to have a strong effect on slag melting point and viscosity, and the implications for the purity of metal produced are discussed. Bringing together the evidence provided by slag chemistry, documentary sources and smelting remains in the archaeological record, changes in tin smelting technology through time, and the consequences thereof, are considered.

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A 20 litre experimental batch and continuous test rig and 5 litre batch and 50 litre continuous test rigs for stirred ball milling were built at the University of Natal and Mintek respectively. All the mills featured a grinding vessel with a central shaft equipped with pins and a torque measurement system. A washed chrome sand from the Bushveld Igneous Complex was used for the grinding experiments. Particle size analysis of products was performed using standard sieves and a Malvern Particle Sizer. Batch tests were run in the 20 litre stirred ball mill to achieve efficient grinding conditions. The effects of grinding conditions such as pulp density, media size, media density and shaft rotation speed and mill design parameters such as ball load, pin spacing and pin diameter on product size, power consumption and media wear were studied. It has been shown that the median size of the product can be calculated by the Charles' Energy-Size Equation. The stirred ball mill has been found to be more energy efficient than the tumbling ball mill. An energy reduction of 50% was possible for a product size of 6 microns when the stirred ball mill was employed instead of the tumbling ball mill. The energy input per ton of grinding media in the stirred ball mill could be 10 times higher than for the tumbling ball mill. Although during coarse grinds the media wear was higher in the stirred ball mill than in the tumbling mill, it became less so as grinding proceeded and for a product median size of 4.8 microns it was the same. Using a 5 litre batch mill, an experimental programme was designed to study the comminution characteristics of the stirred mill. A factorial design was prepared with the following parameters, which influence grinding in the stirred ball mill: pulp density, pin tip velocity and ball density and size. The energy required for grinding the chromite sand in the stirred ball mill was determined by the use of Charles' Equation. The findings were in agreement with the results predicted by this equation. It was shown that the Rosin-Rammler size distribution equation was a suitable procedure for presenting and comparing grinding data obtained from the stirred ball mill. The factors that had the greatest effect on grindability were, in order of importance: ball size, pin tip velocity and ball density. Interactions between grinding parameters were negligible. results implied that accurate predictions can be made to determine the grinding conditions required to achieve a desired product specification. An attempt was made to study the grinding kinetics the chromite are using the mass population·balance model. Grinding tests were performed with two mono size fractions ·53+38 and -38+25 microns and natural feed ·100 microns using various pin tip velocities, ball densities and within the normal stirred ball milling operating range. relationship between the ball diameter and the particle was explained by the "angle of nip" theory which applied for roller crushers. It was shown that the particle giving the maximum breakage rate was directly proportional to the ball diameter. Estimated grinding kinetic parameters from monosize provided a good basis for predictions of natural feed. However, the breakage rate obtained from monosize tests appeared to be lower than those from the natural feed It was found that if the selection and breakage functions were determined by monosize tests, it was possible to modify selection function parameters by back-calculation which gave the best fit to the natural feed size. A good correlation was obtained between the experimental and product distributions using a population-balance model. The links between the empirical model combining Charles' and Rosin-Rammler equations and the first-order batch grinding equation were also shown. The stirred ball mills were operated in batch and continuous mode. The median size of the products from the batch stirred ball mill experiments closely matched those of the continuous grinding experiments under similar grinding conditions. Using a salt solution as a tracer material, an attempt was made to estimate the residence time distribution based on a simplified analysis of the motion of the water in tile mill. The current scale-up methods for the stirred ball mill are discussed. A torque model was developed for given shaft geometry and ball relating the power rements of the stirred ball mill to the following prime design and operating parameters : mill diameter, mill height, pin tip velocity and effective density of the mill load. The basic assumptions underlying the model were that the mill content behaved as a fluidised bed, consequently a P effg h type model for the pressure was applied throughout the grinding media bed the effective charge velocity was proportional to the pin tip velocity. It was found that pin spacing, pin diameter and ball diameter significantly affected the mill torque. A semi-empirical torque model was derived to include these parameters. The relationships formulated from these models were shown to be in excellent agreement with experimental results. / Thesis (Ph.D.)-University of Natal, Durban, 1993.

need to dry-mill the wheat into flour, and as a result, the total cost of conversion from wheat to bread is reduced. The resulting product has been perceived as being more filling than normal bread and it is also more nutritious and more affordable. The wet-mill concept was developed in a laboratory environment and no process methodology or equipment has existed to enable the technology to be used in a real bakery environment. The focus of this research was to design the particular equipment required for a medium plant-bakery production facility based on the wet-mill technology. Due to severe overcapacity in the bread-making industry, the research focuses on how best to integrate this equipment into an existing production facility. Three broad areas are investigated: • Product Development • Process Design • Machine Design The aim of the Product Development phase was to create a recipe that would withstand the rigours of the plant bakery environment, while at the same time satisfying consumer demand for taste and texture. The Process Design phase ensured that any new equipment had the capacity to match the throughput rate of the rest of the plant bakery, so that wet-mill dough could seamlessly continue downstream. Process control variables were examined to ensure that a consistent quality product was delivered. Inbound material handling was also investigated and designed to ensure safe and uncontaminated delivery of perishable raw material. Since the end product is edible, hygiene design requirements were also considered by completing a HACCP study to ensure a consumer-safe product. The Machine Design phase involves the development and design of a completely new food machine: a vertical wet-mill cutter. Many ideas are evaluated and a prototype machine, based on the optimal design, was built to test the concept. This prototype was then used to define process and design constraints for a scaled, large plantbakery machine. The final detailed design of a plant bakery wet-mill cutter was then completed. It includes drive, belt, bearing and pneumatic cylinder selection, and shaft and blade design. Safety considerations were an important part of the design process and production facility. Conformity to OHS Act regulations required investigation into the safe operation of the designed equipment with particular reference to driven and rotating machinery sub-regulations of the Act. A hazard analYSis and operability study was also undertaken. Lastly, the research calculates a financial valuation of the project to ascertain whether a plant baker should be interested in implementing wet-mill technology. The research concludes with a discussion of the various successes of the three research areas, and states any further investigation that may be required before full implementation. / Thesis (Ph.D.)-University of Natal, Durban, 2003.

An increase in the rate of training in the Cold Mill South area due to outside pressure has led to the question whether training is still effective in this environment. The literature study has shown that the most commonly used method to measure the effectiveness of training is to use the Kirkpatrick model. In this study, the aim was thus to follow the four steps of the Kirkpatrick model and use it to measure the effectiveness of training in the Cold Mills South area of the ArcelorMittal Vanderbijlpark works. The following studies were done to determine the four steps: the way that training is done in the Cold Mill area was investigated, the works' perception with regard to training was measured by employing a questionnaire. The questionnaire also investigated any barriers that prevented the workers from performing, information with regard to the different shifts' production performance and training levels was also gathered. The results of the study could not determine that there is a definitive relationship between the training level and shift performance. The workers were very positive towards training, but a few workers felt that there are barriers that prevent them from performing at their workplace. The results of the study showed a few areas where training can be improved, like the retention of skilled workers to help with the training. It is also very important that on-the-job training should be improved. A model similar to that of Brethower and Smalley could be used to improve on-the-job training. / Thesis (M.B.A.)--North-West University, Vaal Triangle Campus, 2009.