The air-jet texturing process for synthetic continuous multi-filament yarns is more versatile than any other texturing process and provides the most effective simulation of natural staple spun yarns. The process itself is inadequately understood, and the ultimate goal of the work is to achieve a better understanding of the mechanism of the texturing process and to make suggestions for more efficient nozzle designs in order to increase productivity and thereby reduce production costs.

Two completely different approaches have been used to study the mechanism of the air-jet method of bulking filament yarns. Part A is an aerodynamic study of the nature of the air flow and of its characteristics, and of the yarn's behaviour during the bulking process. The experimentation involves the use of scaled-up models of the du Pant type 9 commercial Taslan air-jet and of a typically used parent yarn. The study is extended to include a modification of the jet suggested by earlier workers. The results of these investigations provide new evidence regarding the mechanism of the process and the construction of bulked yarns of this type. It is also concluded that the commercially used air-jet on which the model study has been based, is not ideally designed from the stand-point of efficiency, stability and ease of operation. In Part B, a suggested mechanism of the air-jet bulking action is simulated by a purely mechanical means. The simulation of the process has been so effective that yarns of the air-jet bulked type are produced by a method not requiring any compressed air. The preliminary work leading to the design of an experimental apparatus is briefly reported. Theoretical and experimental investigations of the process are made, and the bulked yarn properties for various parent yarn particulars and processing conditions are measured and assessed. An economic evaluation of the process has been attempted, based on a comparison with the limited cost figures available for Taslan processing. - The individual nature of each of the two main investigations has necessitated that the results should be separately discussed in the ultimate Chapter of each Part of the thesis. Suggestions for further work are also made for each of the two techniques.

The thesis deals with the design and production technology of the front hub for a mountain bike. The research focuses primarily on the various control systems of CNC machining apparatuses. The second chapter is devoted to the elemental differentiation of hubs, the concept of personal design of the hub, and the characteristics of the materials for its production and its verification using the FEM analysis. The third chapter deals with the design of a workpiece, instruments and the manufacturing process itself. The design of an NC program constructed in the SinuTrain 4.8. software is dealt with in the fourth chapter. The last part is devoted to the technical and economic evaluation of the proposed solution.

Syftet med detta arbete har varit att ta fram förslag på hur utnyttjandegraden för de maskiner som används till bearbetning av Yankee-detaljer kan höjas, där arbetet har utförts på avdelningen för produktionsutveckling på Valmet AB i Karlstad. Målet med arbetet har varit att identifiera en eller flera produkter av de som idag produceras för externa kunder som skulle vara lämplig att produktionssätta för bearbetning i maskinverkstaden för tillverkning av Yankee-cylindrar. Målet har också varit att presentera en effektiv produktionsmix i maskinverkstaden som med den utvalda produkten genererar 20 000 produktionstimmar i de viktigaste maskinerna. Arbetet genomfördes med en kvalitativ ansats där intervjuer, observationer och litteraturstudier användes för att samla in data. Sekundärdata samlades in från olika databaser på Valmet. Tidigt skapades en projektplan som gav struktur till arbetet och en uppföljning av arbetet ägde rum med pulsmöten veckovis på Valmet. En utredning genomfördes över lämpliga produkter att produktionssätta för bearbetning. Efter val av produkt analyserades olika scenarier för att bestämma en produktionsmix som så effektivt som möjligt genererar 20 000 produktionstimmar. Den framtagna produktionsmixen visade sig generera en del problem vad gäller tillgängliga resurser, PIA, flödet och tillgänglig yta i maskinverkstaden. Med hjälp av Lean-filosofin har sju åtgärder tagits fram som ska leda till att en effektiv produktionsmix uppnås. Införandet av åtgärderna har delats in i tre steg där steg ett (1) anses som nödvändigt att införa för att kunna uppnå produktionsmixen medan steg två och tre är viktiga för flödeseffektiviteten och därmed för att kunna uppnå en effektiv produktionsmix. Resultatet av arbetet visar på att utnyttjandegraden av de viktigaste maskinerna i maskinverkstaden kan höjas genom en produktionssättning för bearbetning av produkten V164. Eftersom produkten tillverkas för vindkraftindustrin kan en produktionssättning för bearbetning även innebära en mindre känslighet för svängningar på marknaden för mjukpappersmaskiner och därmed generera en jämnare arbetsbelastning. / The aim of this work has been to develop proposals on how the utilization rate of the machines used for the processing of Yankee details can be increased. The work has been carried out at the Department of Production engineering at Valmet AB in Karlstad. The objective of the work was to identify one or more products, currently produced for external customers, which are suitable for a production launch for processing in the machine shop for manufacturing of Yankee cylinders. The objective has also been to present an efficient mix of production in the machine shop that with the selected product generates 20,000 production hours in the main machines. The work was carried out with a qualitative approach where interviews, observations and literature reviews were used to collect data. Secondary data were collected from different databases at Valmet. An early created project plan gave structure to the work and follow-up work took place with pulse meetings weekly at Valmet. An investigation was conducted of suitable products for a production launch for processing. After selecting the product various scenarios was analyzed to determine a mix of production that most efficient generate 20,000 production hours. The designed production mix appeared to generate some problems in terms of available resources, WIP, flow and available space in the machine shop. With the help of the Lean philosophy seven measures has been developed that will lead to an efficient mix of production is ​​achieved. The introduction of measures has been divided into three steps. Step one (1) is considered necessary to impose in order to achieve the production mix, while step two and three are important for flow efficiency and thereby to achieve an efficient mix of production. The results of the work show that the utilization rate of the most important machines in the machine shop can be raised through a production launch for processing of the product V164. Thus the product is manufactured for the wind power industry, a production launch for processing also mean less sensitivity to fluctuations in the market for tissue paper machines and thereby a more even workload can be generated.

M.Ing. (Engineering Management) / Engineering design capabilities are highly specialised skills and are often begot through a number of years in a field of specialisation, the research’s aim is to establish how this engineering design capability can be brought into a an organisation through the International Technology Transfer (ITT) medium. In this paper a case study is presented whereby a South African State Owned Organisation (SOC) collaborated with an international company for the acquisition of a new technology, which in turn meant the acquisition of new know-how for the organisation. Despite the dynamics that inherently arise due to the Developed versus Developing Country dynamics it is imperative that the knowledge transfer (KT) initiatives are just as successful, however the difficulty is faced in actually measuring the effectiveness of the knowledge transfer processes. The local engineering industry is still growing and many more of these collaborations are still to be seen in the country, hence it makes it imperative from an engineering management perspective that the quality of the knowledge that can be salvaged from these collaborations is great value for money and is unquestionable. To not only prove the main drivers of the effectiveness of the transfer but to also highlight the areas for improvement a survey in the form of a questionnaire was issued out to the participants of the ITT within the local organisation. Based on literature on similar studies and from the survey results, it is clear that training and engineering human resource development in engineering designs of the technology being transferred is the most important method of ensuring maximum technology transfer. Moreover it was established from the survey results that most often than not this aspect of the transfer process, although ranked as important, is not structured strategically for the benefit of the transferee. Herein, a proposal is thus made as to the key interventions that may be adopted to close the gaps in the technological knowledge aspirations of the organisation.

This diploma thesis deals with the suggestion of solutions to the weaknesses of production technology in the company Strojtex. The introductory part of the thesis contains an introduction to the company as well as an introduction to the tools of Lean manufacturing. As for the analytical part, a SWOT analysis is prepared, and in connection with its results, a proposal for solving deficiencies is made. The final part deals with the selection of a representative of the component with the design of a new production technology and its time and financial evaluation.

Apresenta-se um modelo matemático que avalia numericamente a estabilidade do estado estacionário para escoamentos água-ar em sistemas pipeline-riser de geometria variável. Uma análise a partir da teoria de estabilidade linear é aplicada a um modelo matemático adequado ao escoamento água-ar no sistema pipeline-riser. O modelo considera equações de continuidade para a fase líquida e para a fase gasosa, admite-se escoamento unidimensional e em condição isotérmica. O líquido é considerado incompressível enquanto que a fase gasosa é considerada um gás ideal. Admite-se uma equação de momento simplificada para mistura onde despreza-se a inércia (NPW - Modelo No Pressure Wave) e o padrão de escoamento local é definido com base nas condições do escoamento e na inclinação local. Assim, a intermitência severa é controlada principalmente pela gravidade no riser e pela compressibilidade do gás no pipeline. Tanto a correlação de fluxo de deriva quanto o cálculo da queda de pressão por atrito, adotados como lei de fechamento do modelo, são determinados em função do padrão de escoamento. Injeção de gás e válvula de choke são consideradas, respectivamente, na base e no topo do riser. O modelo é aplicado à sistemas pipeline-riser com escoamento água-ar citados na literatura. Os resultados da análise de estabilidade linear numérica são comparados aos resultados experimentais e numéricos apresentando uma excelente concordância. / A mathematical model that numerically evaluates the stability of the stationary state for hilly terrain air-water flows systems is presented. Numerical linear stability analysis is performed to a suitable mathematical model for the two-phase flows in a pipeline-riser system. The mathematical model considers the continuity equations for the liquid and gas phases, one-dimensional flow and isothermal conditions. The liquid is assumed incompressible while the gas phase is considered as an ideal gas. A simplified momentum equation for the mixture, neglecting inertia (NPW - No pressure wave model) is considered and the local flow pattern is defined based on the flow conditions and the local inclination. In this way, severe slugging is controlled mainly by gravity in the riser and compressibility in the pipeline. The void fraction and friction pressure drop, utilized as closure laws, are determined based on the local flow pattern. Gas injection at the bottom of the riser and a choke valve at the top are considered. The model is applied to air-water pipeline-riser systems reported in the literature. Numerical linear stability analysis results are compared with experimental and numerical results reported in the literature with excellent agreement.

Escoamentos multifásicos estão presentes em diversas aplicações industriais, principalmente na indústria do petróleo. Um dos casos de aplicação, objeto de estudo desse trabalho, é a determinação da produção de poços de petróleo através de válvulas choke. É apresentada uma revisão dos efeitos físicos e do equacionamento adotado pelos principais modelos multifásicos existentes para tais válvulas. Um estudo de sensibilidade de tais efeitos físicos é realizado, analisando as possíveis alternativas para a diferença de velocidade entre as fases, o mecanismo adotado para a troca de calor entre as fases, a influência da energia cinética a montante da válvula, a influência da área efetiva da garganta e a metodologia de cálculo da recuperação de pressão a jusante da válvula. Conclui-se que dos diversos fatores que influenciam no cálculo da vazão mássica e da condição crítica, a área efetiva da garganta é um parâmetro importante e que é necessário uma maior investigação de como determinar tal parâmetro. / Multiphase flow are present in many industrial applications, mainly at the petroleum industry. One of these application cases, aim of this work study, is to determine a petroleum well production by the choke valves. It is presented a revision of the physical effects and for the adopted equation by the main existing multiphase models for such valves. A sensibility study of such physical effects is performed, analyzing the possible alternatives for the phases velocities difference, the adopted mechanism for the heat transfer between the phases, the upstream kinetic energy influence, the throat effective area influencie and the calculation methodology adopted for the valve downstream pressure recover. It is concluded that from many factors that influence in the mass flow and critical condition calculation, the throat effective area is a important parameter and it is necessary a deeper investigation in how to determine such parameter.

Escoamentos multifásicos estão presentes em diversas aplicações industriais, principalmente na indústria do petróleo. Um dos casos de aplicação, objeto de estudo desse trabalho, é a determinação da produção de poços de petróleo através de válvulas choke. É apresentada uma revisão dos efeitos físicos e do equacionamento adotado pelos principais modelos multifásicos existentes para tais válvulas. Um estudo de sensibilidade de tais efeitos físicos é realizado, analisando as possíveis alternativas para a diferença de velocidade entre as fases, o mecanismo adotado para a troca de calor entre as fases, a influência da energia cinética a montante da válvula, a influência da área efetiva da garganta e a metodologia de cálculo da recuperação de pressão a jusante da válvula. Conclui-se que dos diversos fatores que influenciam no cálculo da vazão mássica e da condição crítica, a área efetiva da garganta é um parâmetro importante e que é necessário uma maior investigação de como determinar tal parâmetro. / Multiphase flow are present in many industrial applications, mainly at the petroleum industry. One of these application cases, aim of this work study, is to determine a petroleum well production by the choke valves. It is presented a revision of the physical effects and for the adopted equation by the main existing multiphase models for such valves. A sensibility study of such physical effects is performed, analyzing the possible alternatives for the phases velocities difference, the adopted mechanism for the heat transfer between the phases, the upstream kinetic energy influence, the throat effective area influencie and the calculation methodology adopted for the valve downstream pressure recover. It is concluded that from many factors that influence in the mass flow and critical condition calculation, the throat effective area is a important parameter and it is necessary a deeper investigation in how to determine such parameter.

Project was carried out at the Stock-raising Department of the Faculty of Stock-raising Technology of the Lithuanian Veterinary Academy. For the research the fermented cheese “Liliputas” was taken from UAB “Belvederio sūrinė” and the research was carried out in the laboratory of sensual analysis of the Nutrition Institute of Kaunas University of Technology. Project supervisor – Assoc. Prof. K. Pauliukas. Objective of the project is to adopt the production technology of the fermented cheese “Liliputas”, research the biochemical changes during the course of technological process, and determine the nutrition value. Research was carried out with the fermented cheese “Liliputas”, produced by UAB “Belvederio sūrinė”, by choosing the milk of the cowshed season and the milk of the pasturable season. Changes in the chemical composition and sensual indicators were researched in the laboratory of sensual analysis of the Nutrition Institute of Kaunas University of Technology. The following indicators were researched: pH, humidity (percentage), total nitrogen content (percentage), total protein content (percentage), total soluble nitrogen content (percentage), total soluble protein content (percentage), soluble non-protein nitrogen (percentage), free volatile fatty acids (VFA) NOOH ml, sensual properties (straw-color strength, elasticity when bending, solidity in mouth, viscosity (N), resiliency (mm), etc.). Maximum variation is observed with the free fatty acids when the cheese... [to full text]