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This diploma thesis in theoretical part describes methods of Reverse engineering and Rapid prototyping. Each method describes its characteristics, pros and cons and usability. Practical part deals with application of these methods on part of a ledge of Škoda 1000 MB, digitalization of object, creating a new volume model, analyzing its dimensions and geometry using deviation analysis, creating prototype, choosing suitable manufacturing technology and technical-economical aspects.

Resumo: O aumento do número de produtos com vida útil menor, a intensificação no uso do comércio eletrônico, leis cada vez mais exigentes de responsabilidade sobre descarte dos produtos e uma crescente consciência ambiental têm gerado um elevado número de retornos, fazendo crescer a importância da Logística Reversa para as empresas e para a sociedade, de forma geral. Contudo, constatou-se na literatura que se trata de uma área ainda pouco explorada, que carece de histórico e estatísticas que a mapeiem e, portanto, não existem dados concretos para se trabalhar e explorar as oportunidades de melhoria. Com o intuito de mitigar esta carência, foi realizada uma pesquisa bibliográfica acerca da relação entre a Logística Reversa e o desempenho empresarial, bem como uma pesquisa junto às empresas procurando verificar como se dá este relacionamento. A utilização de um método de pesquisa misto com estratégia exploratória possibilitou captar informação sobre os programas e atividades específicas da Logística Reversa nas empresas brasileiras. Como resultados principais desta tese obteve-se um modelo conceitual para abordar a Logística Reversa na estratégia das organizações e um conjunto de indicadores que possibilitam avaliar o seu desempenho. Adotou-se um Método de Tomada de Decisão com Múltiplos Critérios para ajudar na escolha dos indicadores, que foi a chave para o funcionamento adequado do modelo proposto. A validação do modelo, junto a especialistas das empresas envolvidas na pesquisa, demonstrou que seu uso é factível e que ele oferece alternativas sobre como intervir nas atividades da Logística Reversa no sentido de alinhá-la aos objetivos estratégicos das empresas. / Abstract: The increase in the number of items with a lower useful life, the massive use of ecommerce, an increased environmental awareness and increasingly demanding laws on disposal of products responsibility, has created a elevated number of returns, making to grow the importance of Reverse Logistics for society and companies, in a general fashion. It was found in the literature, however, that Reverse Logistics is still a poorly explored activity, without historical and statistical data that maps it and consequently, there is no concrete data to work with and to explore the opportunities for improvement. With the goal of minimizing this deficiency, a bibliographic research about the relation between the Reverse Logistics and the business performance was made, besides a research along the companies seeking to verify how this relationship is made. Using a mixed research method with exploratory strategy allowed picking up information about the programs and specific activities of Reverse Logistics in Brazilian companies. As the main result of this thesis, a conceptual model for addressing the Reverse Logistics in the organizations strategy and a set of indicators that allow assessing their performance was obtained. A Multiple Criteria Decision Making was adopted to help in the choice of indicators, which was the key to the proper functioning of the proposed model. The validation of the model, along with experts from companies involved in research, has demonstrated that its use is feasible and it offers alternatives on how to intervene in the activities of Reverse Logistics in order to align it with the strategic objectives of companies. / Orientador: Fernando Augusto Silva Marins / Coorientador: Roberto Cespón Castro / Banca: Valério Antonio Pamplona Salomon / Banca: Maurício Cesar Delamaro / Banca: Anderson Ribeiro Correia / Banca: Luis Alberto Duncan Rangel / Doutor

Inom området maskinteknik finns idag ett stort intresse för Reverse Engineering med hjälp av 3Dskanning. Tekniken utgår ifrån att skapa Computer-Aided-Design (CAD) modeller av reala objekt. Föreliggande projekt utfördes vid institutionen för tillämpad fysik och elektronik vid Umeå universitetet i syfte att utvärdera prestationen av Reverse Engineering av objekt som är utmanade at rita direkt i CAD-program. Fyra olika fysiska objekt valdes för analys: en bult, en tolvkantshylsa, en propeller och ett snäckhjul; det sistnämnda tillhandahållen av företaget Rototilt Group AB. Objekten avbildades med en 3D-skannare som använder sig av metoden strukturerat ljus för att läsa in objektens form och har en noggrannhet på 0,04 mm. De 3Davbildade objekten redigerades sedan och CAD-ritningar skapades. Slutligen skrevs CADmodellerna ut med hjälp av en 3D-skrivare och en toleransanalys med gränsvärdet 0,2 mmutfördes för att jämföra dimensionerna av originalobjekten, de olika digitala modellerna samt de utskrivna objekten. Resultatet visar att Reverse Engineering (med vissa begränsningar) är en bra metod för objekt som är utmanade att modellera i CAD. Med tekniken kan fysiska objektrekonstrueras till CAD-modeller snabbt och med hög noggrannhet. / In the field of mechanical engineering, there is an increasing interest in Reverse Engineering using 3D-scanning. The technology is based on creating Computer-Aided-Design (CAD) models of real objects. The present project was carried out at the Department of Applied Physics and Electronics at Umeå University in order to evaluate the performance of Reverse Engineering of objects that are challenging to draw directly in CAD programs. Four different physical objects were selected for analysis: a bolt, a hex socket, a propeller and a worm wheel; the latter provided by the company Rototilt Group AB. A structured light 3D-scanner with a specified accuracy of 0,04 mm was used to image the objects. The 3D images were then post-processed and transferred to CAD software to create the CAD drawings. Finally, the CAD-models were printed with a 3D printer and a tolerance analysis with a limit of 0,2 mm was performed to compare the dimensions of the original objects, the different digital models and the printed objects. The results show that Reverse Engineering (with some limitations) is a good method for objects that are difficult to model in CAD. The technique is well-suited to reconstruct physical objects into CAD-models quickly and with high accuracy.

African horse sickness is an economically important equid disease caused by African horse sickness virus (AHSV). Upon infection, the virus produces seven structural proteins that constitute the virus particle, and four non-structural proteins with various supportive roles during replication. This study focused on the pleiotropic non-structural protein NS3 and its isoform, NS3A. Arthropod-borne viruses are uniquely equipped to replicate in multiple species, often with significant infection cycle differences. Notably, while AHSV infection is highly pathogenic to the mammalian host, the insect vector exhibits no detrimental effect. One potential contributing factor to these observed differences is the viral release mechanism, with NS3/A playing an essential role in mediating these final infection cycle stages. Multiple conserved protein domains have been identified for NS3/A. This study aimed to address questions regarding the way in which these domains contribute to the protein’s function, in mammalian and insect cells, respectively. The initial phase of this study involved augmenting a panel of reverse genetics-derived AHSV NS3mutants. As these viruses each express a modified version of the NS3/A protein, an in-depth investigation into the function of the different conserved domains was possible. Consequently, a comparative analysis of the wild-type and mutant virus strains was conducted in both mammalian and insect cells, using biochemical, virological and microscopy techniques. In mammalian cells, the results indicated a variable contribution of the different NS3/A domains to the cytopathic effect and in ensuring effective virus trafficking and release. The transmembrane (TM) domains were identified as essential mediators of NS3/A intracellular distribution, as the abnormal processing of the TM mutant proteins resulted in their nuclear localisation and unique interaction with another viral protein, NS1. Additionally, the TM domain disruptions resulted in cytosolic virus particle accumulation. A similar mutant phenotype was observed when the C-terminus of NS3/A was deleted, with an apparent lack of efficient virus trafficking and release. Disruption of the NS3/A late domain (LD) resulted in abnormal tethering of virions to the plasma membrane, suggesting that AHSV utilises the cellular ESCRT (Endosomal Sorting Complex Required for Transport) pathway for non-lytic release events within mammalian cells. Comparatively, while some of the NS3/A domains appear to have similar functions within insect cells, key differences were also observed. Most notably, within insect cells, NS3/A localised to the periphery of unique large cytoplasmic vesicle-like structures, likely facilitating non-lytic release. Interestingly, disruption of the TM domains of NS3/A resulted in the degradation of these mutant proteins as they could not be detected within infected cells. Correspondingly, this apparent absence of NS3/A resulted in diminished release, with most of the virus particles remaining cell-associated throughout the course of infection. Notwithstanding normal NS3/A protein localisation, deletion of the C-terminus of NS3/A also prevented proper virus egress. Disruption of the LD did not have any significant effect within insect cells, with no abnormal virus particle localisation and efficient virus release observed. Consequently, in insect cells, virus particle trafficking and release appears independent of characteristic cellular membrane trafficking systems utilised in mammalian cells. / Thesis (PhD)--University of Pretoria, 2020. / National Research Foundation (NRF) / Poliomyelitis Research Foundation / University of Pretoria Institutional Research Theme / Genetics / PhD / Unrestricted

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The effectiveness of reverse osmosis (RO) membrane systems may be compromised due to fouling, of which biofouling (excessive growth of biomass) is the most troublesome. Effective control of biofouling is essential to improve membrane performance and reduce operating costs. The periodic application of chemical cleaning agents is possibly the most widely practiced method of biofouling control in RO membranes. This research investigated advanced chemical cleaning strategies for biofouling control. The first part of this study concluded that short-term accelerated biofouling studies using lab-scale membrane fouling simulators (MFSs) are a representative and suitable approach for the prediction of long-term biofouling development in membrane systems. Thereon, the superior efficiency of urea as an alternative to conventional chemical cleaning agents was demonstrated (i) at lab-scale using MFSs, (ii) for full-scale industrial spiral-wound membranes and (iii) for multiple cleaning cycles during long-term operation. Periodic chemical cleaning with urea resulted in better restoration of membrane performance, higher biomass inactivation, enhanced biofilm solubilization and removal, disintegration of extracellular polymeric substances (EPS) particularly proteins, and a considerable reduction of key biofilm-forming bacteria. This research presented enhanced chemical cleaning strategies aiming to increase the removal of biofilms, reduce biomass accumulation and its impact on membrane performance, and delay fresh biofilm formation.

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No / In this work, a reverse osmosis (RO) desalination process operating under batch mode is considered experimentally. The effect of operating parameters, such as pressure and feed salinity on the permeate quantity and salinity is evaluated. In addition, the water permeability constant, Kw, which is one of the main parameters that affect the optimal design and operation of RO processes is evaluated as a function of changing feed salinity and pressure using the experimental data and two literature models. A strong pressure dependence of the water permeability constant is observed in line with earlier observations. Interestingly, a strong concentration dependence of the water permeability constant is also observed which has always been neglected or ignored in the literature. Finally, for a given pressure, concentration dependent correlations for Kw are developed and are used in the full process model (described by a system of ordinary differential and algebraic equations) for further simulation studies and to validate the experimental results.