El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / This article proposes a work method reform in the production line of self-supporting telecommunication towers of a Peruvian metalworking enterprise. The problem raised considers the cost overruns caused by the delivery and dispatch of incomplete tower kits. The main process evaluated is the assembly of tower kits, which presented multiple deficiencies that we analyzed with multiple engineering tools using the eight steps of practical process improvement. We evaluated by a large scale definition the work table in the assembly and stacking of parts, defining by specific zones each part type and profile, and optimizing the total process times so as not to affect the scheduled dispatches. Thus, it is possible to minimize the number of customer returns.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Small and medium-sized enterprises often rely heavily on their production process to position themselves in the market. However, there are few situations where companies have the knowledge and financial resources to improve their operational performance. This study proposes the use of the tools of the Lean Manufacturing philosophy to reduce most activities that do not add value within the production process. First, the diagnosis of the current situation of the company under study was carried out, as well as the determination of the impact caused by the problems encountered. Secondly, the design of the solution proposal was proposed using 5S, SMED and SLP to mitigate the causes of the previously diagnosed problems. Finally, in the simulation, the production system and the changes proposed obtained a reduction in the lead time, due to the reduction of the unproductive times identified, of 6.79%.

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<p> One of the major industrial metalworking processes is extrusion and it is of technological importance to be able to estimate the loads and material flow characteristics within the deforming metal. Hot metals and superplastic materials are particularly sensitive to the speed of the operation al though it is difficult to col".sider this in an analysis of the problem. </p> <p> This thesis reviews the analytical techniques available to the engineer to determine the loads in bulk forming processes and examines the way in which rate effects have been accommodated. The upper bound method, which is an approximate analytical technique, is reviewed in detail. The concept of a tangential shear zone of constant shear strain rate is introduced and used to enable strain rate effects to be considered within the upper bound technique. The work rate across each discontinuity is shown to be a function of the material strain rate sensitivity, the shear zone width and the tangential veloc i ty change. </p> A number of tangential velocity fields are proposed for the side extrusion process. These are examined and compared by minimizing the work rate using a computer optimization technique. The optimum solution for a simple tangential velocity discontinuity field is shown to give load estimates which are within 10% of those given by the more exact slip-line field method. </p> <p> Experiments, performed by the author on the side extrusion of two materials, which have very different strain rate sensitivities, are reported in detail. A characteristic difference in the extrudate geometry for the two materials is identified and shown to be a result of the difference in the materials strain rate sensitivity index. The experimental extrusion pressures for the two materials at different ram velocities are compared with theoretical values derived using the theory developed earlier in the thesis; the correlation is good. </p> <p> The shape of the tangential discontinuity between a uniform translational and uniform rotational field is examined and shown to be a circular arc. A number of new tangential velocity discontinuity fields are presented for a variety of common metalworking processes. These fields comprise straight and circular discontinuities and represent a new type of "mixed" field which predicts the rotation of the extrudate. </p> / Thesis / Doctor of Philosophy (PhD)

The problem of this study was to determine how much foundry equipment exists in the high schools of Texas and to determine to what extent it is being utilized. The data for this study were provided by thirty-seven metalworking instructors of Texas high schools. Of the Texas high schools offering metalworking as a part of the industrial arts curriculum, few appear to have adequate foundry facilities. In addition, a deficiency seems evident in the background and training in foundry of the metalworking instructors.

Submitted in partial fulfillment of the requirements for the Degree of Masters of Business Administration, Durban University of Technology, 2008. / Industrial buying stands for more than half the whole economic activity in industrialised countries. Therefore, it is important to understand how customers of Afrox perform buying activities. The fabrication industry is a fast growing industry and is, therefore, interesting to study. The understanding of the buying behaviour of industrial organisations is of paramount importance to the industrial marketer. The study is a quantitative, cross sectional and descriptive investigation into buyer behaviour in the fabrication industry of Afrox. It highlights that industrial buyer behaviour has an extensive area, both for the practical marketer as well as from an academic perspective. As the fabrication industry is once again expanding, it is of essence to understand the buying behaviour in this industry. This report has the intention of highlighting how industrial buyer behaviour can be described in the fabrication industry. The purpose of this dissertation was to investigate the characteristics of industrial buying behaviour of fabrication customers at Afrox. The purpose has been further developed in forms of research questions dealing with the buying process, buyer behaviour, buying centre and buyer choice criteria. The sample studied is from a current company data base. With regard to the buying process, the most significant factors are price, quality, and technical capability.

Metalworking fluids (MWFs) are petroleum emulsions employed for metal machining processes as coolants and lubricants. To date, they have been irreplaceable in modern heavy and manufacturing industries, with annual usage exceeding two billion litres worldwide. However, the large amount of MWFs, the highly concentrated complex recalcitrant and toxic petroleum components contained in them continue to cause significant concern in terms of sustainable routes of end-of-life treatment and disposal. Compared with other treatment methods, the anaerobic treatment method has significant advantages, such as the low capital, operating and maintenance costs and energy recovery. This latter factor has the potential benefit of generating bio-energy from waste organic matter whilst aerobic route leads to CO₂ emission. However, the bio-toxicity of MWFs is a huge challenge in terms of employing bio-treatment of waste MWFs. In this study, the anaerobic biodegradability of a typical MWF was investigated employing an activated sludge experimental system. Furthermore, the toxic effects of the MWF on the anaerobic ecosystem, particularly on methanogen species, were investigated using bio-molecular analytical methods and a biosensor. In order to overcome its toxicity, the indigenous anaerobic bacteria isolated from spent MWFs were employed in the treatment of the MWF since they were assumed to be acclimated to the conditions. The major findings include: (1) approximately 80&percnt; of the MWF (5,000mgCOD/L) was found to be anaerobically biodegradable, with around 35&percnt; of the biodegraded COD could be converted to methane; (2) the MWF appeared to be toxic to the anaerobic ecosystem, especially to methanogen species; and (3) however, treatment employing the anaerobic bacteria successfully reduced the toxicity of the MWF and enhanced the methane production in the process.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Program in Science, Technology and Society, 2001. / Includes bibliographical references. / by Robert Martello. / Ph.D.

This research effort highlights emerging areas in the field of robotic polishing and includes an extensive literature survey conducted by the author. This survey shows that areas in need of further investigation for achieving automated polishing are surface measurement, CAD/CAM integration and polishing mechanics. The work conducted has been based on the use of an available robot end-effector for polishing unknown three-dimensional surfaces. A model for determining the mass of material removed during the polishing process is based on hardness testing, surface grinding and milling theory. Using this model the material removed during the polishing process is compared to results from practical experiments. Polishing trajectory for a robot-end effector to follow has been produced using CAD files in Initial Graphics Exchange Specification (IGES) format. Using these files and two types of polishing patterns, the surface roughness of polished surfaces has been compared for simple planar polygonal surfaces. / Master of Engineering (Hons)

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