Product life cycle (PLC) is the cycle which every product goes through from introduction to eventual demise. There are several issues with the current life cycle of a product when looked from the environmental impact perspective. These are: 1) depletion of natural resources due to the use of virgin materials for production, 2) Consumption of substantial amounts of energy during manufacturing, assembly and use, and 3) production of large amounts of waste during the lifecycle including those at the End of Life (EoL) phase. These issues impact resource scarcity, adverse effects on the environment and loss of embodied energy as waste. Some of the potential solutions to these issues, as proposed in literature, are: to recycle, reuse and remanufacture products in order to reclaim materials, components and sub-assemblies from used products and make them available for new products. In order to efficiently carry out these recovery processes, a pre-requisite is disassembly. Product disassembly is defined as the processes of systematic removal of desirable constitute parts from an assembly while ensuring that there is no impairment of the parts due to the disassembly process. The following are the major research issues in the field of disassembly. One is the conflict between environmental and economic goals, i.e. as to which should be targeted at in disassembly objectives. These conflicts lead to abandoning non-destructive disassembly techniques so as to favour the profit objective. The other issues, prevalent during EoL phase, are: corrosion due to use, less residual value in the parts, complicated structure and intricacy in parts, which together make non-destructive disassembly a task difficult for automation. This means that disassembly processes have to be carried out by human operators. The manual disassembly processes are effort intensive and pose ergonomic risks to the human operators involved in disassembling. The nature of ergonomic risks and effort spent in disassembly is influenced by the efficiency of disassembly operation. However, little research has been carried out to address the above factors of effort, profit, efficiency, environment and ergonomic risk during disassembly in an integrated manner. These factors form the major motivations for the research work carried out in this thesis. A series of empirical studies have been undertaken to assess these factors and their impact on product disassembly. The studies focus on disassembly processes for consumer electronic products in two major recycling sectors in developing countries, leading to development of metrics with which the above factors can be assessed individually and traded off in an integrated manner during the early design stages of a product. These metrics should help designers understand and improve the major disassembly aspects of a product during designing and help prevent major disassembly problems at the EoL phase while improving efficiency of recovery options. The objective of this thesis, therefore, is to develop an Integrated Framework for supporting decision making during early stages of design to improve disassembly during the EoL phase of the product. The framework is intended to help in evaluating alternative designs for easy (less effort), profitable, efficient and environment-friendly disassembly at the EoL phase of the product life cycle. The Framework constitutes new measures developed for supporting decision making on above aspects of disassembly during the early stage of designing. The Framework has been implemented into a computer based tool called ‘IdeAssemble’ and evaluated for its functionality with the help of a design experiment. The tool can be used at the embodiment stage of the design phase, when on an exploded view of the product, with information on its materials, geometry, disassembly tools and types of disassembly task are available to the designer.

Manufacturers are increasingly being held responsible for the fate of their products once they reach their end-of-life phase. This research uses a combination of total disassembly time and recyclability to gauge the environmental impact of a product at this stage of its use. Recyclability, or wasted weight, is a function of the material contained by a product’s subassemblies as it is taken apart. This project suggests a graph-based method of representing product assemblies. Unlike many existing representation methods which are used in the field of automated disassembly, the method proposed here takes component connection methods into account. This, combined with a library of disassembly defining graph grammars, ensures that the disassembly simulation performed on this assembly approximates real-life disassembly procedures as closely as possible. The results of this simulation are Pareto sets whose contents represent various points in the disassembly process. Each member of the set is evaluated using the two primary parameters of disassembly time and wasted weight. This Pareto set can be used to judge a particular product’s performance during end-of-life, from the perspective of recyclability, against that of another product. / text

European manufacturing companies are facing challenges of increasing prices of raw material, more customized products and competitiveness from industries outside Europe. Those challenges make the manufacturing require flexible production processes. The remanufacturing industry has the advantages of produce products using less raw material and to a lower cost compared with manufacturing. This makes the remanufacturing industry a way for the European companies to stay competitive. Challenges of the remanufacturing process are the operator exposure of vibrations, monotony tasks and ergonomic issues when disassembling the incoming core. To meet the challenges and stay competitive the Swedish manufacturing industries is currently examine the advantages of collaborative robots and how implementation of collaborative robots can improve production. Implementation of a collaborative robot at a workstation requires risk assessment as human safety is an important aspect to consider. Simulation modelling can advantageously be used to examine future state scenario or investigate how a current system is affected by different variables. To meet the challenges described the aim of this thesis has been to examine how to facilitate the design of a collaborative disassembly workstation by means of simulation. The work with the thesis is based on a case study made at a Swedish remanufacturing company. Following research questions has been formulated to fulfil the purpose:    <li data-leveltext="-" data-font="Arial" data-listid="48" data-aria-posinset="0" data-aria-level="1">What are the challenges of verifying the operators´ safety by using simulation?  <li data-leveltext="-" data-font="Arial" data-listid="48" data-aria-posinset="0" data-aria-level="1">What are the advantages and disadvantages of implementing a cobot in a disassembly station?  <li data-leveltext="-" data-font="Arial" data-listid="48" data-aria-posinset="0" data-aria-level="1">How can simulation be used to facilitate decision making when developing a collaborative workstation?    Results show simulation challenges as human’s movements, robot characteristics and the ability to simulate it, core condition uncertainty, software knowledge and time consuming simulation modeling. Human-robot collaboration enables to combine the characteristics of human flexibility and robot precision and repeatability. The robot can advantageously perform tasks which are detected as monotonous or not ergonomic to a human. Simulation can advantageously be used in an early stage of designing layout of a collaborative workstation for reachability verification.

Nesta tese é apresentado um novo método de desmontagem das placas de circuito impresso obsoletas ou defeituosas, provenientes de resíduos de equipamentos eletroeletrônicos, para aplicação no processo de reciclagem. A desmontagem tem por objetivo segregar a PCI para que o material reciclado apresente maior pureza, bem como facilitar as etapas posteriores no processo de reciclagem. A desmontagem proposta é classificada como automática, simultânea e destrutiva. O método apresentado não requer o uso de tecnologias avançadas e de alto custo. Para aplicação deste método foi desenvolvido um protótipo que utiliza aquecimento do ar para derretimento da solda e força centrífuga para remoção dos componentes. O desenho deste equipamento permite a separação da PCI em 3 partes distintas: substrato, solda e componentes eletrônicos. Para a desmontagem no protótipo foram usadas placas marrons de fontes de alimentação, e placas verdes de memórias tipo RAM, com substrato de fenolite e de fibra de vidro respectivamente. A desmontagem foi realizada com sucesso em ambos os casos. Para as placas pesadas ou marrons, a faixa de operação que apresentou maior taxa de recuperação de solda (entre 2,2 e 2,8% do peso da PCI) e de componentes (entre 60 e 80% do peso da PCI) situa-se entre 200 e 206°C e 900 rpm. Para placas leves ou verdes, a desmontagem deve se situar entre 210 e 225°C e 900 rpm, sendo a quantidade de solda recuperada inferior a 1% e a de componentes aproximadamente 32% do peso da PCI. A liga de solda recuperada dos dois tipos de placas possui contaminação abaixo de 3%, teor semelhante à da borra proveniente de processos industriais de soldagem e que é utilizada como matéria prima. / In this work, is presented a new method for disassembly of obsolete or defective printed circuit board, from waste of electrical and electronic equipmente, for use in recycling. Disassembly objetives separate PCB to achives purer recycled material as well facilited the subsequent step in recycling process. Proposed disassembly is classified as automatic, simultaneous and destructive. The presented method doesn\'t required the use of advanced and expensives technologies. For this method, a prototype was developed. It utilizes centrifugal force and air heating for solder melting and components removal. Design of the prototype allows separation of PCB in 3 parts: substrate, solder and electronics components. Very low grades boards of paper laminated phenolic resins, from power supply of computers was used, as well as very high grade boards from RAM memory, made of fiberglass. Disassembly was sucessfully for both cases. For very low grade boards, operation range which has a greater amount of recovered solder (between 2,2 and 2,8% of weight of PCB) and components (between 60 and 80% of weight of PCB) is inside the range of temperature of 200 and 206°C and 900 rpm. For very high grade boards, disassembly is inside the range of temperature of 210 and 225°C and 900 rpm, with quantity of recovered solder under 1% and components aproximatelly 32% of weight of the PCB. Recovery solder for the two kinds of PCB has a contamination under 3%, similar to spare from industrial welding process, used as input in the production of new solders.

Hemoglobin plays an important role in transporting oxygen in human beings and other mammals. Hemoglobin is a tetrameric protein composed of two alpha and two beta subunits. The £\ and £] subunits are both necessary and the stoichiometric ratio of the two dislike subunits is critical for hemoglobin to perform its oxygen-carrying function properly. To better understand the coupling between the £\ and £] subunits and the subunit disassembly pathway, p-hydroxymercuri-benzoate (PMB) has been used to react with the cysteine residues in hemoglobin. The hemoglobin tetramer becomes unstable and disassembles into £\ and £] subunits when the cysteine sites are perturbed upon reacting with PMB. There are three kinds of cysteine residues, £]93, £\104 and £]112, in human hemoglobin. The reactivity of different cysteine residues with PMB and their reaction sequence have been studied via the Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). The resonance Raman spectroscopy has been used to investigate the structural changes of hemoglobin accompanying the PMB-modification under the oxygenated and deoxygenated conditions. At last, a hemoglobin subunit disassembly mechanism is proposed and the site-specific roles of cysteine residues in human hemoglobin are discussed in detail.

The RNA helicase Prp43p is one of the few members of the DEAH-box helicase family that is known to operate in more than one cellular process in Saccharomyces cerevisiae. With roles in ribosome biogenesis and pre-mRNA splicing, Prp43p may be important in maintaining a communication conduit between these two pathways. Our studies provide insights into how Prp43p function is regulated through the use of three cofactors, Ntr1p, Pfa1p, and Gno1p, all of which interact with Prp43p at different steps of pre-mRNA splicing or ribosome biogenesis. Each cofactor contains a unique G-patch domain and our data show that they associate with Prp43p in a mutually exclusive manner. A strong growth defect and RNA processing phenotypes are seen upon overexpression of Pfa1p due to the dominance of Pfa1p interaction with Prp43p. Moreover, excess Pfa1p precludes Prp43p from interacting with either 35S pre-rRNA or U6 snRNA, indicating this one cofactor can negatively regulate Prp43p recruitment into ribosome biogenesis and pre-mRNA splicing pathways, respectively. We have determined that Ntr1p and Gno1p are able to compete with one another for Prp43p occupancy. Similar to Ntr1p, we show that the G-patch domain of Gno1p contributes to its association with Prp43p. To further understand pathway specificity of Prp43p, we characterized conditional prp43 alleles with mutations C-terminal to the conserved RecA domains of Prp43p. These novel alleles affect pre-mRNA splicing and ribosome biogenesis, though none are mutually exclusive. Multiple prp43 alleles are deficient in tri-snRNP formation, a previously uncharacterized phenotype in prp43 mutants. The majority of our prp43 mutants display varying rRNA defects, with some alleles impacting ribosome biogenesis more severely or moderately than known prp43 ATPase mutants. To correlate the processing defects seen in each allele, we have determined the extent of association of the mutants with each G-patch protein. Altogether, our data support a working model for Prp43p in which its substrate specificity, activation, and cellular distribution is coordinated through the efforts of the three G-patch proteins in yeast and sheds light on potential mechanisms of general DExH/D helicase function and regulation. / text

In this study, we deal with the profit oriented partial disassembly line balancing problem which seeks a feasible assignment of selected disassembly tasks to stations such that the precedence relations among the tasks are satisfied and the profit is maximized. We consider two versions of this problem. In the profit maximization per cycle problem (PC), we maximize the profit for a single disassembly cycle given the task times and costs, part revenues and demands and station costs. We propose a heuristic solution approach for PC based on the liner programming relaxation of our mixed integer programming formulation. In the profit maximization over the planning horizon problem (PH), the planning horizon is divided into time zones each of which may have a different disassembly rate and a different line balance. We also incorporate other issues such as finite supply of discarded product, subassembly and released part inventories availability, and smoothing of the number of stations across the zones. PH is decomposed into a number of successive per cycle problems, which are solved by a similar heuristic approach. Computational analysis is conducted for both problems and results are reported.

Thesis (Ph.D. in Biochemistry & Molecular Genetics) -- University of Colorado at Denver and Health Sciences Center, 2006. / Typescript. Includes bibliographical references (leaves 169-185). Free to UCD Anschutz Medical Campus. Online version available via ProQuest Digital Dissertations;

Orientador: Marystela Ferreira / Resumo: Neste trabalho foram desenvolvidos diferentes tipos de filmes Layer-by-Layer (LbL) sensíveis a variação de pH, temperatura, exposição a luz e presença de carboidratos, com o objetivo de criar sistemas com resposta a estímulos que podem ser aplicados na área médica e ambiental para a entrega modificada de fármacos e pesticidas. O trabalho foi dividido em três partes, sendo o primeiro focado na liberação da emodina. Foram fabricados filmes com a emodina imobilizada diretamente e outra em que o fármaco foi encapsulado nos lipossomos formados por dipalmitoil fosfatidil glicerol (DPPG) e palmitoil fosfatidil glicerol (POPG) e então intercalado com polieletrólitos. Ambos os filmes foram expostos a condições fisiológicas e liberaram a emodina por um período prolongado em função da mudança de pH e temperatura. A segunda parte do trabalho é focado na construção de filmes com um polímero baseado em espiropirano (poli(SP-R)), um composto que quando recebe luz UV é convertido para a forma aniônica merocianina (poli(MC-R)) mudando sua cor e carga superficial. O filme foi composto pelo policátion poli(alilamina hidroclorada) (PAH) formando o (PAH/poli(SP-R))n que se desprendeu do substrato pelo processo disassembly após longo tempo de exposição à luz branca. Na terceita parte do trabalho foram desenvolvidos filmes com o polímero baseado em ácido fenil borônico (PBA), que tem a capacidade de se ligar covalentemente à açucares. Foram fabricados intercalado com PVS resultando no filme (PEI/PV... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In this work, we developed some types of Layer-by-Layer (LbL) films sensible to pH and temperature changes, light exposition and carbohydrates solutions, with the aim of to create stimuli responsive system that can be applied to medical and environmental area to drug and pesticide modulated delivery. The work was divided in three parts, the first one is based on delivery emodin. One film was fabricated with emodin immobilized directly and other the drug was encapsulated on liposomes formed by dipalmitoyl phosphatidyl glycerol (DPPG) e palmitoyl phosphatidyl glycerol (POPG) and the carrier was intercalated with polyelectrolytes. Both systems were exposed to physiologic conditions and released the emodin for prolonged time in function of pH and temperature changes. On second part of this work it was focused on construction of film with spyropiran (SP) based polymer (poli(SP-R)). The UV irradiation over (poli(SP-R)) causes the conversion to anionic and purple merocyanine molecule (poli(MC-R)) changing the color and surface charge. The film were composed by poly(allylamine hydrochloride) (PAH) and poly(SP-R) forming the (PAH/poli(SP-R))n LbL film which disassemble after long time exposed to white light. On third part of work, films were developed with phenyl borônico acid (PBA) based polymer that has the capacity to bind covalently on sugars. The films were intercalated with PVS creating the coating (PEI/PVS)2(PBAp/PVS)n. It were prepared also a film with the pyranine (PYR), the ... (Complete abstract click electronic access below) / Doutor

Com a crescente demanda por inovação e o fato dos produtos apresentarem cada vez mais uma vida útil reduzida, têm-se hoje a produção de um grande número de diferentes produtos, gerando resíduos e aumentando enormemente o volume dos lixões e aterros sanitários. Na busca por inovações deve-se seguir uma metodologia específica para que ela seja eficiente. Ao buscar novas soluções para um determinado produto, o primeiro passo é analisar os produtos já existentes e seus respectivos materiais. Esta análise, com o intuito de desenvolver novas soluções para problemas conhecidos, é determinada “Análise de Similares” e se revela uma importante ferramenta para avaliar os produtos disponíveis no mercado. A seleção do material adequado é fundamental no desenvolvimento do projeto, e para criar um produto em condições de competir com os já existentes é necessário inovar nos materiais, no design e nos processos de fabricação. Na questão da sustentabilidade, outro importante aspecto é em relação à desmontabilidade dos produtos, que influi diretamente na reciclabilidade dos materiais e componentes. No presente trabalho busca-se analisar como diversos produtos hoje são concebidos quanto a sua desmontagem e seleção de materiais por meio de estudos em relação à Análise de Similares. Busca-se igualmente compreender na prática se as metodologias que hoje são utilizadas em projetos contemplam as variáveis ambientais. Para isso, as análises foram focadas nos aspectos estruturais, nos elementos de junção e nos materiais dos similares, pois entende-se que essas são variáveis ambientais importantes a serem analisadas. Foram verificadas as metodologias empregadas nos estudos, organizando-as de forma coerente, a fim de tornar o estudo mais preciso e funcional. E na etapa de resultados buscou-se investigar os diferentes materiais presentes e os elementos de junção que fazem parte dos produtos, sistematizá-los e organizá-los na etapa de discussão. A partir desses estudos partiu-se então para realizar uma contribuição para uma metodologia com enfoque no Design para a Desmontagem. / Because of the increasing demand for innovation and the fact that products have presented shorter life spans, we have today the production of a huge number of different products generating waste and enormously increasing the volumes of landfills and sanitary embankments. In this search for innovation, a specific methodology must be followed in order to achieve efficiency. A first step when searching for new solutions for a certain product would be analyzing already existing products and its materials. This kind of analysis, intended to develop new solutions for well-known problems, is called “Analysis of similars”, an important tool to evaluate the available products in the market. The material selection is fundamental for the project development, and to create a product capable of competing with the already existing ones it is necessary to innovate in the use of materials, design, and the manufacturing process. Another important factor, related to sustainability, is the possibility of disassembling the products, allowing for the recycling of materials and reusing of components. In this paper we try to investigate through analysis of similars how products today are conceived in relation to disassembling possibilities and to material selection and understand if the methodologies used in projects nowadays consider environmental variables. In order to accomplish that, the analysis focused on structural aspects, as well as on the junction elements and the similar materials, because we understand that those are important environmental variables that should be analyzed. We analyzed the methodologies used in different studies, organizing them in a coherent way in order to turn the study more precise and functional. In the Results chapter we carried out an investigation of the various materials and elements of junction that are part of the products to later systematize and organize them in the Discussion chapter. From that point we tried to contribute for the development of a methodology focusing on the Design for Disassembly.