Dissertations / Theses on the topic 'Recycling techniques'

Sequences of matrices arise in many applications in science and engineering. In this thesis we consider matrices that are closely related (or closely related in groups), and we take advantage of the small differences between them to efficiently solve sequences of linear systems and eigenproblems. Recycling techniques, such as recycling preconditioners or subspaces, are popular approaches for reducing computational cost. In this thesis, we introduce two novel approaches for recycling previously computed information for a subsequent system or eigenproblem, and demonstrate good results for sequences arising in several applications. Preconditioners are often essential for fast convergence of iterative methods. However, computing a good preconditioner can be very expensive, and when solving a sequence of linear systems, we want to avoid computing a new preconditioner too often. Instead, we can recycle a previously computed preconditioner, for which we have good convergence behavior of the preconditioned system. We propose an update technique we call the sparse approximate map, or SAM update, that approximately maps one matrix to another matrix in our sequence. SAM updates are very cheap to compute and apply, preserve good convergence properties of a previously computed preconditioner, and help to amortize the cost of that preconditioner over many linear solves. When solving a sequence of eigenproblems, we can reduce the computational cost of constructing the Krylov space starting with a single vector by warm-starting the eigensolver with a subspace instead. We propose an algorithm to warm-start the Krylov-Schur method using a previously computed approximate invariant subspace. We first compute the approximate Krylov decomposition for a matrix with minimal residual, and use this space to warm-start the eigensolver. We account for the residual matrix when expanding, truncating, and deflating the decomposition and show that the norm of the residual monotonically decreases. This method is effective in reducing the total number of matrix-vector products, and computes an approximate invariant subspace that is as accurate as the one computed with standard Krylov-Schur. In applications where the matrix-vector products require an implicit linear solve, we incorporate Krylov subspace recycling. Finally, in many applications, sequences of matrices take the special form of the sum of the identity matrix, a very low-rank matrix, and a small-in-norm matrix. We consider convergence rates for GMRES applied to these matrices by identifying the sources of sensitivity.
Doctor of Philosophy
Problems in science and engineering often require the solution to many linear systems, or a sequence of systems, that model the behavior of physical phenomena. In order to construct highly accurate mathematical models to describe this behavior, the resulting matrices can be very large, and therefore the linear system can be very expensive to solve. To efficiently solve a sequence of large linear systems, we often use iterative methods, which can require preconditioning techniques to achieve fast convergence. The preconditioners themselves can be very expensive to compute. So, we propose a cheap update technique that approximately maps one matrix to another in the sequence for which we already have a good preconditioner. We then combine the preconditioner and the map and use the updated preconditioner for the current system. Sequences of eigenvalue problems also arise in many scientific applications, such as those modeling disk brake squeal in a motor vehicle. To accurately represent this physical system, large eigenvalue problems must be solved. The behavior of certain eigenvalues can reveal instability in the physical system but to identify these eigenvalues, we must solve a sequence of very large eigenproblems. The eigensolvers used to solve eigenproblems generally begin with a single vector, and instead, we propose starting the method with several vectors, or a subspace. This allows us to reduce the total number of iterations required by the eigensolver while still producing an accurate solution. We demonstrate good results for both of these approaches using sequences of linear systems and eigenvalue problems arising in several real-world applications. Finally, in many applications, sequences of matrices take the special form of the sum of the identity matrix, a very low-rank matrix, and a small-in-norm matrix. We examine the convergence behavior of the iterative method GMRES when solving such a sequence of matrices.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado.
The use of foamed asphalt as a technique that incorporates recycled bases stabilized with RAP is known, because it achieves important structural contributions. However, the component of aggregates, belonging to the fine fraction (through the # 200 mesh) takes special importance. This article seeks to develop a comparative analysis between the stabilizations of recycled foamed asphalt bases and asphalt emulsion. The importance of this study lies in analyzing the structural contribution of the fines fraction when comparing both stabilizations. For the present investigation, 48 pits were examined, where the combined granulometry of the RAP plus the granular base was evaluated. Here it was possible to identify a minimal presence of fines even within the recommended spindle for foamed asphalt mixtures, evidencing a deficit in indirect traction strength (ITS). The results obtained show, that a dry stability of 484.7 kg is achieved, and a conserved strength of 45% in the foamed asphalt. While in the asphalt emulsion a dry stability of 1862.1 kg and a conserved resistance of 70% is achieved. This demonstrates the impact on the structural behavior that have the fines fraction in stabilizations with foamed asphalt.

The scrap metal recycling industry is a growing industry that plays an important role in the sustainability of a large global metal supply. Unfortunately, recycling lacks many standards, and test procedures in place for mineral processing. These standards and practices, if used in recycling, could aid recyclers in determining and achieving optimal separations for their plant.. New regulations for scrap imports into China make it difficult to obtain the metal recoveries that have been achieved in the past. In order to help scrap yards adhere to the new regulations the Eriez RCS eddy current separator system was tested in full scale. The principles this system uses, called circuit analysis, have been used by the mining industry for years, and can be used with any separation system. The Eriez RCS system surpassed the requirements of the Chinese regulations, while simultaneously increasing the recovery of metals. In order to further analyze eddy current separator circuits, tree analysis was attempted for single eddy current separators, as well as more complex circuits mimicked using locked cycle tests. The circuits used in the locked cycle test were a rougher-cleaner, a rougher-scavenger, and a rougher-cleaner-scavenger. It was found that it is possible to use tree analysis to compare different eddy current separator circuits using the same settings, however standards for this practice need to be established for it to be useful. Using the data analysis methods developed for this particular tree analysis, the rougher-cleaner-scavenger test had the best performance overall. This is the same result as the full scale testing done on the Eriez RCS system, but more testing should be conducted to confirm the data analysis techniques of calculating theoretical efficiency, recovery efficiency, and rejection efficiency.
Master of Science

The horticulture industry is facing limited water resources and public pressure to reduce non-point source pollution. In some circumstances, recapturing and recycling of irrigation water in horticultural nurseries can generate significant savings relative to the costs of alternative water sources and potentially reduce non-point source pollution. However, obtaining these savings may also incur substantial risk and capital cost outlays. Disease risk may increase in nurseries that implement recapturing and recycling if recycled water is not properly treated. These added costs must be compared with costs of alternative sources of water, such as municipal or well water. This study employed partial budgeting to compare irrigation water being extended or supplemented through recapturing and recycling against the most feasible alternative. On-site visits were conducted to obtain information for partial budgets and to clarify the reasoning of nurseries choosing to recycle irrigation water. The partial budgets were supplemented with sensitivity analysis with regard to the extraction cost of water and opportunity cost of land used for recapture of water. Six of eight nurseries obtained water from recapturing and recycling at a lower cost compared to a feasible alternative source. The regrading of land for maximum recapture, opportunity cost of land dedicated to a recapture pond, and the cost of municipal water were parameters that were critical to the irrigation choice. Sensitivity analysis indicated that water price and land cost had little effect on the least cost option. Irrigation recycling could be incentivized to motivate further water conservation within the horticulture industry.
Master of Science

The production of textiles, focusing on cotton and polyester, carries with it major environmental concerns such as significant water and chemical use as well as the use of non-renewable resources. Measures need to be taken to decrease those environmental burdens. The present study investigates four different recovery techniques in terms of specific environmental factors. The investigated recovery methods are the Re:newcell method, polyester recycling, textile to insulation material and biogas production from the digestion of textile waste. Incineration is also included as a reference alternative. Waste flows in Sweden are estimated through a literature review of conducted waste analyses and estimations as to the amount of secondary product that can be produced from that input are duly made. Further, the environmental implications of three potential locations for a sorting facility are investigated. Converting cotton into biogas was found to be an unrealistic approach since it is economically inviable and little or no energy is actually gained when transportation costs are taken into consideration. Further studies on the benefits and costs of recycling cotton into insulation material are needed. The unavoidable transportation related to collection, sorting and recycling are not to be underestimated and could in some cases hinder future environmental improvements.  Finally, the study found that fiber material recycling is the only treatment method that has the potential to decrease the environmental burdens related to primary production although, despite the fact it requires the most water and chemicals. However, the data reliability in the current study is a matter of concern and further research in the form of standardized data collection and the use of analytical and strategic tools in further assessments is recommended. Although the recovery of textile material is crucial for decreasing the environmental burdens from primary production of textiles, the work in preventing textile waste is even more vital. In the long run, the prevention of waste is far more important as recovery processes demands their own share of resources.
Den primära produktionen av textilier för med sig enorma miljömässiga påfrestningar. Omfattande mängder kemikalier och vatten samt icke-förnybara resurser används vid tillverkningen av bomull och polyester. Det är nödvändigt att vidta åtgärder för att minska dessa negativa effekter på miljön. Denna studie syftar till att undersöka fyra olika återvinningstekniker för textilt avfall med fokus på bomull och polyester. Förbränning med energiutvinning inkluderas som ett referensfall och återvinningsteknikerna jämförs med hjälp av utvalda miljöfaktorer. De återvinningstekniker som jämförs är Re:newcells metod för återvinning av bomull (och andra cellulosa material) till viskosfiber, kemisk polyesteråtervinning, återvinning av bomull till isoleringsmaterial för byggnader samt rötning av bomullstextilier för utvinning av biogas. Avfallsströmmarna i Sverige uppskattas med hjälp av litteraturstudier av framförallt genomförda plockanalyser. Alla faktorer jämförs med avseende på 1 ton blandat textilavfall från hushåll i Sverige och hur mycket av det som kan användas som potentiell råvara i återvinningsprocesserna. Vidare undersöks även de miljömässiga effekterna som uppstår vid transport av det textila avfallet till en sorteringsanläggning och till återvinnigsanläggningar. Tre potentiella placeringar av sorteringsanläggningen undersöks: Stockholm, Vänersborg och Wolfen, Tyskland. Studien fann att endast fibermaterialåtervinning har möjlighet att motverka de miljömässiga påfrestningarna från primärproduktionen även om de också innebär den största användningen av resurser såsom vatten och kemikalier. Rötning av bomull till biogas anses vara ett orealistiskt alternativ då metoden är ekonomiskt oförsvarbar och lite eller ingen energi egentligen utvinns när man inkluderar de nödvändiga transporterna. Vidare studier behövs för att uppskatta nyttan och kostnaderna för återvinning av bomull till isoleringsmaterial. De transporter som oundvikligt behövs vid återvinning pga. insamling, sortering och återvinning bör inte underskattas och kan i vissa fall förhindra att miljönyttan ökar. Resultaten i studien bör däremot användas kritiskt då tillförlitligheten i det data som har använts i vissa fall kan ifrågasättas. Detta beror på att många antaganden och uppskattningar har gjorts pga. brist på data av sekretesskäl. Mer forskning och undersökningar rekommenderas i form av standardiserade metoder för plockanalyser av textilt avfall. Användningen av analytiska och strategiska verktyg såsom LCA och EIA/SEA rekommenderas för att ta hänsyn till alla intressenter vad gäller end-of-life för textilt avfall. Fastän återvinning är en nödvändig del i arbetet att minska på de miljömässiga påfrestningarna som primärproduktion bidrar till är det ännu viktigare att arbeta med åtgärder för att minska avfallet. Återvinning kräver sin andel resurser i from av energi, vatten och kemikalier bland annat.

Different methods for quality assessment of separated andcommingled plastics from household and electronic waste havebeen developed. Especial attention has been given tospectroscopic methods since they are non-destructive andrequire little or no sample preparation at all.

A wide variety of low molecular weight compounds have beenidentified in recycled polyethylene (HDPE) and polypropylenefrom hard packaging waste by gas chromatography- massspectroscopy (GC-MS) after microwave assisted extraction (MAE).Low molecular weight substances such as alcohols, esters,ketones and fragrance and flavour compounds were detected inthe recycled resins. The major category of compounds identifiedin the virgin resins is conformed by aliphatic hydrocarbonssuch as alkanes and alkenes. It was found that theconcentration of aromatic hydrocarbons without functionalgroups, e.g. ethylbenzene and xylenes in recycled HDPE wasapprox. 5 times higher and equal to 120 and 35 ppb,respectively.

The potential of near infrared (NIR) and Fourier transformRaman (FT-Raman) spectroscopy in combination with multivariateanalysis as a rapid, non-destructive and accurate analyticalmethod has been studied and the feasibility of these methodsfor at/in line characterisation of several properties ofrecyclates has also been explored.

NIR in diffuse reflectance mode has been successfully usedfor quantification of antioxidants in polyethylene, thestandard error of prediction is almost comparable to the errorof wet methods, i.e., extraction plus liquid chromatography.The error of prediction of this method is 35 ppm for Irganox1010 and 68 ppm for Irgafos 168. The inaccuracy in thequantification of Irgafos 168 is due to the fact that thisantioxidant degrades during polymer processing.

NIR and Mid-infrared (Mid-IR) worked well for fastdetermination of molecular weight and crystallinity of therecycled HDPE and acceptable errors of prediction, comparableto that of the reference methods, i.e. size exclusionchromatography (SEC) and differential scanning calorimetry(DSC) have been obtained.

The present thesis also shows that NIR and Raman are goodcandidates for in/on line compositional analysis of mixedpolymer fractions from recycled plastic waste. Diffusereflectance NIR allows a rapid and reliable measurement ofpellets and requires no previous sample preparation. Thecomposition of binary blends can be determined with highaccuracy. The PP content in the PP/HDPE blends was predictedwith a RMSEP equal to 0.46 %w in the 0-15 %wt region and theRMSEP for PP in the PP/ABS blends was 0.3 %wt.

The thermal and thermoxidative stability of recycled PP,HDPE and a 20/80 PP/HDPE blend subjected to multiple extrusionhave been studied by DSC, thermal analysis (TGA) andchemiluminiscence (CL). A decrease in T_oxand OIT was observed after each extrusion step.The drop in OIT was sharper after the first two extrusions. TheOIT values produced by DSC and CL were in good agreement.However, CL provided more information about the oxidationprocess taking place in the blends.

The moisture content in recycled polyamide 6,6 was readilydetermined by NIR in transmission mode and it could bepredicted with a RMSEP = 0.05 %wt. The accuracy of the methodappeared to be as good as that of the more time consumingthermal methods such as TGA, DSC and loss on dry (LOD), whichwere used as reference methods. The influence of differentamounts of water on the viscoelastic properties of nylon hasbeen investigated.

Keywords:Recycling, HDPE, PP, blends, nylon 6,6, ABS,water content, MAE, GC-MS, NIR, FT-Raman, chemiluminiscence,low molecular weight compounds, antioxidant content,crystallinity, molecular weight, thermal stability,characterisation methods, analysis of polymers, blends.

La contribution des travaux de cette thèse porte sur la détermination de l'option de fin de vie adéquate à chaque produit à recycler. Ceci revient à évaluer un produit, donc à classifier ses compsants suivant deux options: réparation ou réutilisables, en tenant compte de leur qualité, des coûts, des revenus éventuels d'une telle classification et enfin des contraintes et des objectifs du recyclage. Cependant, l'absence totale des informations sur la "vie antérieure" du produit à évaluer augmente la complexité de l'évaluation. Notre problématique consiste à tester l'état du produit pour en déduire l'état de ses pièces. La solution que nous avons envisagée consiste alors à tester la bonne marche de ses services. Dans ce but, des séquences de test seront appliqués au produit. Nous nous sommes intéressés à la génération automatique de séquences de test afin d'appliquer la séquence de test la plus appropriée à chaque type de produit. Les phases suivantes sont la caractérisation des symptômes de défaillance (la détection) et l'identification de son origine (le diagnostic). Après avoir identifié l'état du produit et de ses composants, la stratégie la plus adaptée pour le produit est choisie selon un certain nombre d'indicateurs économiques. Enfin, une séquence de démontage est générée selon l'option choisie

Les Déchets d'Equipement Electriques et Electroniques (DEEE) constituent un volume important de déchets dont le constituant majoritaire est l’ABS. C’est pour cela que nous avons travaillé principalement avec des polymères provenant d’un gisement réel (carters d’ordinateurs). Puis, des mélanges ABS/PC ont été élaborés (le PC étant un des constituants d’un gisement de carters), dans le but d’obtenir un matériau avec une résilience au moins équivalente à celle d’un ABS neuf. Même si l’ABS a montré une bonne aptitude à être recyclé seul, après vieillissement et recyclage, sa résilience connaît une chute due à la dégradation de la phase élastomère et à la présence d’ignifugeants. Il est important pour le recyclage de l’ABS et de ses mélanges de séparer les polymères ignifugés de ceux qui ne le sont pas. La voie mélange pour le recyclage de l’ABS par l’ajout de PC a l’avantage de simplifier le tri et de recycler un maximum des polymères présents dans les DEEE. Nous avons tout d’abord réalisé des mélanges ABS/PC neufs pour bénéficier d’une mise en œuvre et d’une composition optimales. L’influence des paramètres du procédé de recyclage (température et vis d’extrusion) et des propriétés des matériaux (taux et viscosité du PC, retardateurs de flamme de l’ABS) sur les propriétés du mélange a été étudiée. Nous avons effectué essentiellement des essais de résistance au choc Charpy et des études morphologiques. Les résultats ont montré qu’une morphologie fibrillaire ou co-continue est favorable à la meilleure résilience des mélanges ABS/PC. Nous avons obtenu pour des mélanges neufs ABS neuf FR/PC neuf réalisés avec 70% d’ABS une résilience supérieure à celle de l’ABS neuf. Mais, à composition égale, ce résultat n’a pas été atteint pour les mélanges majoritaires en ABS recyclé. Souhaitant réaliser des mélanges performants majoritaires en ABS recyclé, la compatibilisation semble nécessaire. Un mélange recyclé majoritaire en ABS, compatibilisé avec du PP-g-MA, est montré plus résilient que l’ABS neuf seul. Toutefois, les compatibilisants ont une efficacité limitée lorsqu’ils sont en présence de retardateurs de flamme ou soumis à un temps de séjour élevé dans la presse à injecter. Nous avons voulu utiliser des nanocharges minérales (montmorillonites), ajoutées en faible quantité, en tant qu'ignifugeants et compatibilisants. Elles se sont avérées inefficaces dans les études préliminaires réalisées. Le choix des nanoargiles minérales doit être optimisé
WEEE constitute a huge waste volume in which ABS is the major component. So, we focused on polymers from a real deposit (casing of computers); such a deposit contains ABS, PC, PS, ABS-PC. In a first step, recycling of aged ABS was studied. The decrease in the C=C content induces an impact strength drop. Nevertheless, ABS proved to be recyclable given that optimized processing conditions are found. The role of flame retardants was shown to be crucial on the recyclability. Separating polymers with or without flame retardants is the key point of the ABS recycling. However, recycled aged ABS do not recover the impact strength of neat virgin ABS. Then, ABS/PC blends were elaborated in order to obtain a material with an impact strength at least equivalent to the neat ABS. The use of ABS/PC blends for this recycling facilitates the sorting and the utilization of most of WEEE polymers. We first made ABS/PC blends from virgin polymers to have optimal processability and composition. Performing Charpy impact strength tests and morphological studies allowed to evaluate the influence of recycling process parameters (temperature and screw extrusion) and material properties (rate and viscosity of PC and ABS flame retardants). Experimental results indicate that the impact strength of the ABS/PC blends is higher when the morphology is fibrillar or co-continuous. We obtained ABS virgin FR/PC virgin blends (70/30) with an impact strength greater than the neat ABS. But, with equal composition, this result was not reached for the blends. So to achieve reliable blends rich in recycled ABS, compatibilisation is necessary. Recycled ABS/PC blends compatibilised with PP-g-MA is more resilient than the ABS. However, the compatibilising agents have a limited efficiency when they are used in the presence of flame retardants or subjected to a high residence time. Finally, nanoclays were attemptively used as both FR and compatibiliser. Tough they proved uneffective in the very first experiments carried out (the choice of clay need to be optimized)

Testability is crucial in today’s complex industrial system on chips (SoCs), where sensitive on-chip analog voltages need to be measured. In such cases, an operational amplifier (opamp) is required to sufficiently buffer the signals before they can drive the chip pad and probe parasitics. A single-stage opamp offers an attractive choice since it is power efficient and eliminates the need for frequency compensation. However, it has to satisfy demanding specifications on its stability, input common mode range, output swing, settling time, closed-loop gain and offset voltage. In this work, the settling time performance of a conventional folded-cascode (FC) opamp is substantially improved. Settling time of an opamp consists of two major components, namely the slewing period and the linear settling period. In order to reduce the settling time significantly without incurring excessive area and power penalty, a prudent circuit implementation that minimizes both these constituents is essential. In this work, three different slew rate enhancement (SRE) circuits have been evaluated through extensive simulations. The SRE candidate providing robust slew rate improvement was combined with a current recycling folded cascode structure, resulting in lower slewing and linear settling time periods. Exhaustive simulations on a FC cascode amplifier with complementary inputs illustrate the effectiveness of these techniques in settling time reduction over all envisaged operating conditions.

Electrophoresis is a widely used analytical technique in the medical and biotechnology industries. It can provide for the determination of thousands of individual compounds on this small scale. The operating conditions are quite conducive to use with the delicate products of genetic engineering. Due to other complexities associated with scale-up, the process is not widely used on a large scale. A novel recycling electrophoretic instrument was investigated as a preparative protein separation device. The process occurs in a thin film of liquid between two flat plates, in a direction perpendicular to the flow. This device was unique in its use of a relatively high flowrate, and recycling of the process fluid as a method for increasing residence time. The apparatus was operated in three modes, isoelectric focusing (IEF), zone electrophoresis (ZE) and isotachophoresis (ITP). For use in the ITP mode, a computer was used for data acquisition and control functions. Model systems included monoclonal antibodies and lentil lectins.

Today’s consumption of textiles generates a large volume of textile waste. Therefore, it is needed to find solutions to re-use the textile waste rather recycling fibers into new fibers. Research using pre- and post-consumer textiles in composites is ongoing and an interesting direction. This thesis reports the recycling of discharged cellulose containing textiles by production of all-cellulose composites (ACCs). ACCs are composites consisting entirely of cellulose. ACCs from discarded denim and polycotton hospital sheets (PCO) were successfully produced with partial dissolution and two-step method. Discarded denim fabrics with 100% cotton (CO) and blend material (BCO) was sorted and shredded into fibers, then made into nonwovens by needle punching. The produced nonwoven laminates and intact hospital sheets were used as the reinforcement in the composites while dissolved cellulose in an ionic liquid (IL), 1-butyl-3-methyl imidazolium acetate ([BMIM][Ac]), was used as the matrix phase. The matrix is then regenerated by removal of the [BMIM][Ac] by washing to form the composite. The washed-out [BMIM][Ac] was collected and recycled in order to study the effect of its reusing as recycled cellulose solvent on mechanical properties of ACCs. Combinations of the different methods, materials and solvents were studied. The mechanical properties – tensile, flexural and impact properties and the void content of the produced composites were deter-mined. Microscopic analysis was done to study the cross-section of the composites. It could be concluded that the achieved values for the mechanical properties can be compared with ACCs found in literature. The results from the research implies that it is possible to find a new purpose for recycled textiles in the form of composites. With this approach, it is possible to avoid unnecessary disposal of textiles containing cellulose.

De-inking sludge generated from pulp and paper industry is considered hazardous since it may contain heavy metals such as Cd, Cr, and Pb. Hence, the de-inking sludge needs to be treated before being disposed of. Sludge combustion is a proven disposal technology, which generates fly ash containing a portion of the heavy metals that may leach out under uncontrolled conditions. The aim of this thesis is to implement a new multi-zone temperature combustion technique (Low-High-Low temperature combustion, LHL) to help contain and immobilize the heavy metals within fly ash particles. During the LHL, the waste will be initially fed into a low-temperature zone (<1100 K) and then subjected to the high-temperature treatment (~1480 K) that will be followed by another low-temperature zone (~1100 K).
This dissertation describes the detailed design and construction of a novel pilot-scale combustion facility, called the Multi-Mode Combustion Facility (MCF), used as a multidisciplinary research tool for investigating the thermal remediation of contaminated solid residues. The MCF is capable of operating in two different modes: Fluidized-Bed combustion mode (FBC) and Single burner furnace mode (SBF). However, this project focuses on the FBC mode (minimum fluidization velocity of 0.42 m/s and bed temperature of 1073 K).
This research compares the combustion characteristics of de-inking sludge obtained in the LHL and in the conventional combustion techniques. The following properties of particulates were studied: morphological evolution of solid particles, structural porosity, metals interactions with fly ash particles, and leachability.
The LHL's final supermicron spherical fly ash went through a molten phase with submicron particles attached to the fly ash particles surfaces. Thus, reducing its porosity to 19%. However, the amorphous final fly ash obtained in the conventional technique reveals 32% porosity. It was found that the physical characteristics of the final LHL's fly ash are the main cause for the reduced heavy metals leachability rates of 0.18, 0.046, and 0.92% for Cd, Cr, and Pb, respectively. The conventional technique had 53.28, 16.79, and 5.20% of Cd, Cr, and Pb respectively, leaching out due to the high porosity percentages. In conclusion, the LHL technique allows for controlling the heavy metals emission from FBCs, while using a waste to energy approach and maintaining environmentally acceptable gas emission levels.

Le recyclage des déchets plastiques issus des déchets d'équipements électriques et électroniques (D3E) est devenu un enjeu majeur de nos sociétés afin de limiter leur impact environnemental. Le recyclage mécanique apparaît aujourd’hui comme une solution mature industriellement et adaptée pour produire de matières premières de recyclage (MPR). L’objectif de cette thèse est la compatibilisation de mélange de plastiques issus de la filière de tri des D3E en vue de leur valorisation par recyclage mécanique. La caractérisation des mélanges D3E par des analyses FT-IR, fluorescence-X, ATG et DSC a montré qu’il s’agissait de mélanges complexes contenant majoritairement des polymères styréniques et des polyoléfines et de faible pourcentage de PVC, PMMA, PC… Ces mélanges, mis en œuvre, présentent des propriétés mécaniques très faibles par rapport aux polymères techniques et de commodité. Ces résultats ont démontré la nécessité d’une compatibilisation de ces D3E en vue de leur transformation en MPR. Au vu de la complexité des mélanges, la compatibilisation in situ à l’aide de réactions radicalaires est apparue particulièrement prometteuse. Une première approche a consisté à générer les radicaux par irradiation puis, en deuxième approche, par ajout d’amorceurs chimiques. Ces deux approches n’ont pas produit d’améliorations significatives des propriétés. Suite à ces résultats, des essais de compatibilisation par ajout de copolymères ont été entrepris, conduisant à une amélioration importante des propriétés mécaniques. La réalisation de prototypes techniques, à partir de MPR compatibilisés, a été validée et permet de démontrer leur potentiel technique
The recycling of the plastics from waste electrical and electronic equipment (WEEE) has attracted great attention recently for environmental reasons. Mechanical recycling has emerged as the most economical, as well as the most energetic and ecologically efficient option. The aim of this work is the mechanical recycling of WEEE mixed plastic waste (MPW) streams. First, MPW composition has been evaluated by FT-IR and X-ray fluorescence spectroscopies, and ATG and DSC analyses. MPW are complex blend composed of thermoplastics, mainly styrenic polymers (ABS, HIPS, PS) and polyolefins. The remaining were other thermoplastics as PVC, PE, PMMA, PC…. After processing, these mixtures show very low mechanical properties compared to commodity and engineering thermoplastics. These results demonstrated that compatibilization is necessary to transform these D3E into secondary raw materials (SRM). In situ compatibilization using radical reactions appeared to be an attractive solution. Two pathways have been studied to generate the radicals, firstly, by electron beam radiation and, secondly, by adding chemical initiators. These two approaches didn’t show any substantial improvement in mechanical properties. Following these results, compatibilization by addition of reactive and non-reactive commercial copolymers were undertaken, leading to a significant improvement in mechanical properties. The production of technical prototypes and 3D printing wires from compatibilized SRM has been validated and allows considering an industrial development

Cette thèse comprend trois expériences et deux prétests (N = 1135) dans lesquelles sont étudiés trois aspects fondamentaux du design statique des messages sur internet : son format (infographie, audio ou texte), sa couleur et sa typographie, sur la thématique du recyclage des déchets électroniques (études 1 et 2) puis à propos de la migration humaine (étude 3).L’étude des aspects graphiques est pertinente si l’on veut augmenter la force persuasive d’un message. Le format joue un rôle prépondérant (étude 1a), permettant à la fois de changer les attitudes, mais aussi d’ancrer ce changement dans le temps. Les couleurs, par contre, ne semblent pas faire varier la force persuasive du message ou amener les lecteurs à agir en faveur du recyclage (étude 1b). La typographie ne semble pas non plus jouer de rôle dans la dynamique persuasive, qu’elle soit jugée lisible ou peu lisible (étude 2). Des pistes théoriques concernant la personnalité des typographies et leur cohérence avec le contexte sont développées.L’analyse des composantes de l’ELM a révélé, dans chaque étude, le fort lien entre l’attitude des individus et leur sentiment de responsabilité personnelle envers la thématique abordée ainsi que leurs connaissances a priori. Nous avons également vu que les leviers de persuasion ne sont pas systématiquement les mêmes selon le besoin de cognition.Globalement, nous suggérons que les messages persuasifs doivent adopter un format permettant une analyse centrale à faible coût cognitif, utilisant une couleur principale et une typographie toutes deux lisibles et cohérentes avec la thématique développée, avec un argumentaire qui renforce le sentiment de responsabilité des lecteurs
This thesis includes three experiments and two pre-tests (N = 1135) in which three fundamental aspects of static message design on the Internet are studied: its format (infographics, audio or text), its colour and typography, on the theme of electronic waste recycling (studies 1 and 2) and then on human migration (study 3).The study of graphic aspects is relevant if we want to increase the persuasive power of a message. The format plays a major role (study 1a), making it possible to change attitudes and to anchor this change over time. Colours, on the other hand, do not seem to vary the persuasive force of the message or to lead readers to act in favour of recycling (study 1b). Nor does typography seem to play a role in the persuasive dynamic, whether it is considered legible or difficult to read (study 2). Theoretical approaches regarding the personality of typographies and their coherence with the context are developed.The analysis of the components of the ELM revealed, in each study, the strong link between the attitude of individuals and their sense of personal responsibility towards the theme addressed as well as their a priori knowledge. We have also seen that the levers of persuasion are not systematically the same according to the need for cognition.We suggest that persuasive messages should adopt a format that allows for central analysis at low cognitive cost, using a main colour and typography that are both readable and consistent with the theme developed, with arguments that reinforce readers' sense of responsibility

碩士
大葉大學
工業工程與科技管理學系碩士在職專班
98
Production of polyvinyl chloride (PVC) using either a suspension or a emulsification method entails producing large quantities of wastewater. The suspension method produces effluent at a 4.0 m3/tonne PVC rate. Because the effluent has lower amounts of SS and COD, there were many research and case studies of its reclaimation. However, since the PVC particles in the effluent are not biodegradable and they tend to plug membrane pores causing fouling, hence it has a relative low reclaimation rate and high treatment cost problem needing resolution. The emulsification method produces ca. 2.5 m3/tonne PVC. Due to the high SS and COD concentration, however, there is a lack of announced successful treatment case that can provide reference to the trade. In this study, we engaged the effluent from a PVC mill in Taiwan and proceeded to treat it for reclaimation purpose. The study was conducted in 3 stages. In the first stage, the PVC effluents were mixed at a fixed ratio (suspension method 22% vs. emulsification method 78%) and fed to a ColOX bioreactor and a sand filtration unit for the preliminary treatment. The treatment variable studied was hydraulic retention time (HRT) effects on the removal efficacies of COD, PVA particles and SS. In the 2nd stage, the discharge from the ColOX unit was respectively treated with granular activated carbon, and ozone/UV irradiation (O3/UV) processes to allow recycling of the effluent. In the activated carbon experiments, effects of the absorbent on the adsorption of organic compounds and determination of the saturation point were examined. In the O3/UV process, the ozone infusion rate, and oxidation time on the removal efficiency of the organics were examined. In the 3rd stage, the potential for using the reclaimed water as makeup water for cooling tower was investigated. Treatment efficiency of different approaches were analyzed and compared. The first stage ColOX study results indicated that an HRT of 2 h provided the best removal efficacy. Thus, we’ve set the flow rate to 31.2 L/min, and HRT of 2.0 h for a persistent trial run. After the ColOX unit, effluent COD decreased from an average of 104 to 35 mg/L, with a COD removal rate of 66.6%. The 2nd stage activated carbon study showed that by setting an inflow rate of 4 L/min and continuously operated for 3 mo, until the activated carbon failed, the average influx COD of 34 mg/L was reduced to 13 mg/L, with removal rate of 62%; and the activated carbon granules lasted for 64 d (ca. 2 mo), afterward their performance gradually declined. Thus, activated carbon granules should be replaced or subjected to regeneration every 2 months. The O3/UV treatment entailed an ozone dosage of 100 g/h influsion rate and 6 sets of UV irradiation conditions. The results indicated that after 4 min of oxidation, the effluent COD reduced from 38 mg/L to 17 mg/L, with a removal rate of 56%. In the 3rd stage, we conducted a model mill cooling tower makeup water test using the treated effluents. A fixed ratio of 65.7% reclaimed water and 34.3% waters of other sources was used, and dispersant, corrosion inhibitor, and microbial dispersant were preadded, and the pH adjusted to 7.8~8.2, residual chlorine set to 0.2~0.5 mg/L. After 14 d of operation, we found that on-line deposition meter showed a cleanliness of 99.8%, a caron steel coupon corrosion rate of 0.299 MPY (< 2 MPY demanded by the standard); a copper coupon corrosion rate of 0.017 MPY (< 0.5 MPY demanded by the standard). Thus, indicating that the reclaimed water for cooling tower makeup water did not cause scaling of the heat exchange tube array and deposition or corrosion of the system. Furthermore, even concentrating the cooling water 6-fold, the water still met the limitations, confirming that the reclaimed effluent could serve as makeup water for cooling tower. Upon evaluating the treatment efficiency, capital cost and problems caused by solid wastes of PVC effluent systems, we deemed that a treatment flow of ColOX + sand filtration unit + O3/UV was superior to a system employing ColOX + sand filtration unit + activated carbon for treating PVC process effluents.

碩士
逢甲大學
環境工程與科學所
95
The major objective of the study is to set up a treatment system and using filtration, electrolysis and photolysis to clear up the organic matter in wastewater of Compact Disc. Utilizing the active carbon of bamboo and bone black as filtrating material to compare adsorbability of them, separately confer the removal efficiency of organic matter with different electric current, and add TiO2 with dissimilar weight to the photolysis to observe its removal efficiency of organic matter. In the end, get the best treatment to combine with filtration to form a complete treatment system. The result exhibit that COD removal efficiency separately up to 51.7% and 64.87% of wastewater after filtrate by carbon of bamboo and bone black, after electrolyze with 0.5~3.0A current, the removal efficiency of organic matter separately up to 18.97%, 21.55%, 29.31%, 45.69%, 50% and 56.03%, and after add 0g, 0.1g, 0.2g and 0.3g catalyst into wastewater its COD removal efficiency separately reach 17.24%, 20.69%, 35.34% and 43.97%. According to the result, the study select electrolysis to combine with filtration to form a new treatment system, after disposing with this new treatment system, the removal efficiency arrive at 97.32% and 98.45%, not only transform the intrinsic quality of wastewater but also enhance the removal efficiency. However the concentration of the aluminum ion is 44.7 mg/L, it does not arrive concentration of recycling and reusing.

碩士
中華科技大學
機電光工程研究所在職專班
107
The main purpose of this research is to find ways for expanded polystyrene(EPS) manufacturers in Taiwan to be able to remain prosperous under the condition of respecting and protecting the environment by reviewing the manufacturing processes, environmental issues caused by EPS, rate of EPS recycling in Taiwan, and the techniques for processing and recycling the EPS waste. Because of its excellent properties and its cheap price, EPS has been broadly used in almost every area. As a result of mass production and single-use, EPS has finally been accused as one of the major causes of environmental pollution. Plans to limit or to ban using EPS are adapted one by one by many authorities around the world. Finding new applications and effective ways to process or to recycle EPS are definitely the solutions to help the EPS manufacturers to break through these difficulties. To find a new application for EPS is not an easy task since it has already been on the market for a long time. But utilizing EPS as geofoam for constructions and buildings seems still has its space in Taiwan since this is an area touched by only a few people. Other application suggested from this research is to use the recycled EPS as the filler of light weight mortar. Ways to process or to eliminate the EPS waste include landfill, incineration, pyrolysis, and biodegradation. When incineration is used, EPS may save the fuel cost since it has high heating value. Its heating value is 19% higher than that of the petroleum coke. Pyrolysis is a good way to chemical recycle the unrecyclable or unclassified plastics waste, especially used in remote islands by the convenient recycling it provided and the economically return from its yields. Thermal decomposing EPS yields 89.5~97% of combustible oil and 2.5-9.9% of gas. Larva of the darkling beetles such as the yellow mealworm, super mealworm, and dark mealworm are EPS eating worms. However the consumption rates of these worms are redeemed as slow for large scale application to recycle EPS. Scientists have already find the bacteria inside the mealworm’s gut that digests the EPS. Furthermore, scientists are eager to find ways to utilize the enzyme found inside these worms to make fertilizer so that fast and vast biodegradation can be processed. Techniques to recycle EPS include thermal melting, mechanical methods, and dissolution. The machine to cut the large piece of EPS into small piece of EPS peanut has already on the market. The other way of using machine for recycling is motivated by that 90% of the non-load bearing wall of the newly built high rises in Taiwan are light weight wall. The light weight mortar consists 50% of EPS beads. If the recycled EPS is shredded into about the size of the bead, it would be more than appropriate to replace the EPS bead. Even the dissolution method is a more favorable way to recycle EPS waste, the solvents used are either hydrocarbons or organic solvents, which presents strong undesirable odor or be harmful to workers. Using the natural solvents extracted from plants for EPS recycling has been an important topic. Although Limonene was used to recycle EPS waste, its commercial application was impeded by its high cost. Researches about using natural extracts from wildly available plants are undergoing. The natural solvents from the leaf oils of Abies sachalinensis and Eucalyptus species were investigated and suggested that they are good alternatives for the petroleum based solvents. In Taiwan, camphor trees are fast growing and wildly available, I would highly recommend a further investigation.

博士
國立臺灣科技大學
營建工程系
99
Pavement work usually has wide coverage and longer mileage, and it also consumes huge stone (aggregate) resources. In view of this, it would be an urgent issue to seek alternative aggregates that are practical for mixing the pavement material. Due to the limit of depleting natural resources in the local market, in order to maintain a balanced eco-environment and ensure the economic development of mankind, energy conservation and recyclable materials should be developed for pavement work in the future; i.e., the use of green building materials conserve energy and are recyclable. Due to the restriction of source and instable properties, the mechanical property and the durability of asphalt concrete containing the recycling green building materials (RGBM) is therefore confined so that the pavement performance is usually lower than the of asphalt concrete fabricated from conventional crushed stone (CS). For this reason, to enhance the mechanical property of the asphalt concrete fabricated from recycled aggregate (RA) and to maintain the performance and durability of the pavement after putting into service, a number of three (3) recycling green building material reinforcing techniques are proposed in this research to study the pavement performance of asphalt concrete from three aspects, i.e. aggregate grain properties, binder type and aggregate gradation constitution. In this research, the theoretical method of the gray system is employed to develop the rutting deformation rate prediction model and the absorption coefficient prediction model. In the meantime, the research results will also be collated to work out the reinforcing technique action and application program. The following are concluded according to the result of this Research: In “aggregate pre-coating reinforcing techniques”: As one layer of intrinsically prepared pre-coating material is attached on the pre-coated aggregate (PCA), it is capable of patching the tiny cracks on the surface of the RA and reinforcing the surface strength of the RA so as to alleviate the ability of RA in resisting crushing and wearing. The research result of the grey relational analysis indicated the following: Optimal solution could be obtained for the PCA mixed from 0.25mm coating thickness. By replacing the asphalt concrete mixed from CS with the PCA fabricated with the optimal solution, the pavement performance of the asphalt concrete could be enhanced. By incorporating the PCA reinforcing techniques in the asphalt concrete, the grey relational analysis result indicated that optimal coating material and optimal coating thickness could be achieved for the PCA when coated with 0.25mm of slag cement pastes and that the asphalt concrete fabricated from the optimal solution can also effectively enhance the overall pavement performance. In “binder reinforcing techniques”: In this respect, the cement emulsified asphalt paste (CEAP, briefed as cement asphalt paste) will be used as the binder to enhance the cohesion force between aggregates and improve the counter-checking effect between them. According to the mixing ratio designed for the CEAP ingredients, which is mixed in CA12SA30 (C/EZ=1:2; FSP/EA=3%), it can not only enhance the stability, strength and durability of the cement emulsified asphalt concrete (CEAC) but can also improve the overall pavement performance. When applying the CEAP reinforcing techniques to the grey relational analysis of asphalt concrete pavement, the result indicated the following: The CEAC fabricated by cold mixing method with PCA can further enhance the pavement performance of the asphalt concrete in which, the asphalt concrete from the SPPCA would be the optimal solution to the application of CEAC reinforcing techniques and asphalt concrete pavement. In “aggregate gradation constitution reinforcing techniques”: The optimal aggregate gradation is selected by aggregate packing method for mixing the CEAC. Further, the entire or part of the PCA is used to replace natural coarse aggregate by mixed packing and gradation method. The research result indicated the following: The PCA is configured by coarse surface and porous internal structure to increase the asphalt absorption amount; besides, these coarse aggregates are also bonded tightly together to provide stabilized aggregate gradation constitution. When applying packing grading aggregate reinforcing techniques to the grey relational analysis of asphalt concrete pavement, the result indicated that the asphalt concrete fabricated from packing grading mixing design method (PGMDM) can further enhance the pavement performance of the asphalt concrete fabricated from conventional asphalt concrete design method; and that optimal solution could be achieved by the CEAC mixed from CEAP and SPPCA for applying in the Packing grading aggregate reinforcing techniques and the relevant asphalt concrete pavement. In the rutting deformation rate prediction model and absorption coefficient prediction model, the model development result indicated the following: The residual value and mean square root error of rutting deformation rate prediction model and absorption coefficient prediction model are very small. The result of two-tailed test indicated that the measured value and the predicted value are mutually correlated, therefore it can be verified that a higher level of accuracy can be predicted for the rutting deformation rate and the absorption coefficient.

博士
國立東華大學
材料科學與工程學系
101
Sewage sludge is produced by urban waste water treatment. Because of the perishable organic substances, sludge disposal without advanced treatment can produce public health problem. Lightweight aggregate synthesized with sewage sludge is a feasible method for sludge recycling and natural constructive materials saving, but the sintering temperature is always over 1000 oC to form melting glassy phase and large energy is consumed. This study focused on adding some low melting point compounds (H3BO3 and Na2CO3) as flux in order to lower the sintering temperature of artificial aggregates. Water adsorption, apparent porosity, bulk density, compressive strength, and soundness test were applied to evaluate the effect of experiment condition on the characteristics of synthetic aggregates. In addition, there were three other wastes which were used as raw materials for aggregates synthesis in this study, including sludge ash derived from sewage sludge, paper sludge and stone manufacturing sludge. As a result, all these industrial waste could be transformed to lightweight aggregates by thermal treatment and the characteristics of these aggregates were different in a reasonable range. According to the experimental design, sewage sludge was adjusted by adding SiO2 to make the SiO2/Al2O3 ratio of the conditioned sludge up to 4. When the flux of H3BO3 was used, 3 wt% of conditioned sludge of CaO was added to prevent the occurrence of black core phenomenon. Conditioned sewage sludge mixed with 13 wt% H3BO3 and 3 wt% CaO were heated at 400 oC for 0.5 hr and 850 oC for 1hr was followed to get highest compressive strength aggregate. The values of four primary parameters of aggregate (including water adsorption, apparent porosity, bulk density and compressive strength) were 3.88 %, 3.93 %, 1.05 g/cm3, 29.7 MPa. The flux was Na2CO3, the highest value of compressive strength of aggregates were got when sludge mixed with 16 wt% Na2CO3 and sintered at 400 oC for 0.5 hr; 900 oC for 1 hr. The values of the four primary parameters of aggregates are 1.36 %, 1.7 %, 1.26 g/cm3, and 27.7 MPa. Sewage sludge ash was also adjusted by adding SiO2 and the ratio of SiO2/Al2O3 was 4. The identical dosages of both H3BO3 and Na2CO3 were 22 wt% of conditioned ash. When the flux was H3BO3, the synthetic aggregates with high compressive strength were sintered at 900 oC for 15 min. When the flux was Na2CO3, the aggregates with higher compressive strength were sintered at 900 oC for 0.5 hr. The values of the four primary parameters of aggregates mentioned above were 5.43 %、5.15 %、0.97 g/cm3、29.2 MPa and 1.42 %、1.64 %、1.17 g/cm3、88.4 MPa respectively. Because the content of Si of paper sludge was too low, SiO2 was added to make the SiO2 content up to 12 wt% of the wet paper sludge. The dosage of H3BO3 was 18 wt% of the conditioned paper sludge and the sintering program was 890 oC for 30 min. The aggregates synthesized with this procedure have the lower water adsorption and the values of the four primary parameters of aggregates are 4.64 %, 2.77 %, 0.6 g/cm3, and 13.2 MPa. Lightweight aggregates can be produced from stone manufacturing sludge with 15 wt% of H3BO3. The sintering program was set for 850 oC 15 min. The water adsorption, apparent porosity, bulk density and compressive strength of the aggregates were 0.21 %, 0.35 %, and 1.67 g/cm3 and 66.9 MPa. Sewage sludge, sewage sludge ash and paper sludge were investigated to be adsorbent for Methylene Blue (MB, cationic dye) and Procion Red MX-5B (PR, ionic dye). Sewage sludge contained organic compounds with oxygen-rich functional group (such as humic substances) which can adsorb pollutants in the water. In order to improve the adsorption ability and filtration efficiency of sewage sludge, Fe3O4 was synthesized on the sewage sludge by hydrothermal method. Fe3O4 can not only act as an adsorptive site for ionic dye, but also decrease the specific resistance of sewage sludge by crystallization. The experimental results showed that ideal pH for modified magnetic sewage sludge to adsorb MB and PR were 6 and 3, and the isotherm adsorption was fitted well to Langmuir equation. The maximum adsorption capacity for MB and PR were 25.06 and 18.83 mg/g. Pseudo-first-order and pseudo-second-order models were utilized to realize the kinetic adsorption of MB and PR. The adsorption data of both dyes were fitted pseudo-second-order model well and the activation energy of MB and PR adsorption were 42.78 kJ/mol and 32.69 kJ/mol, respectively. The crystalline of Fe3O4 synthesized on sewage sludge improved the filtration efficiency of modified magnetic adsorbent and the filtration resistance was decreased from 1.34×107 s2/g to less than 0.08×107 s2/g. Different from sewage sludge, sludge ash was under thermal treatment and the organic compounds were oxidized to CO2 so that sludge ash particle possessed no organic functional group on the surface. In this study, ferrite process was also conducted on sludge ash and Fe3O4 can act as adsorptive site for ionic dyes because Fe3O4 can provide electrostatic attraction to ionic dyes. The zeta potential of Fe3O4 was positive in acid and anionic dye can be adsorbed. Similarly, that was negative in alkali solution and cationic dye can be adsorbed. As the result of adsorption, MB was well adsorbed in pH 9 and that for PR was 2.7 which corresponded to the zeta potential of modified magnetic sludge ash. The isotherm adsorption and kinetic adsorption of MB and PR were also investigated. For isotherm adsorption, the results were fitted Langmuir equation well and the maximum adsorption capacities of MB and PR were 22.27 mg/g and 28.8 mg/g. For kinetic adsorption, pseudo-first-order and pseudo-second-order models were utilized to examine the adsorption behavior and the results were fitted pseudo-second-order models well. The activation energy calculated from Arrhenius equation was 61.7 kJ/mol for MB and 9.07 kJ/mol for PR. Owing to paper sludge contained large amount of organic compounds such as fibers and lignin, it could be pyrolyzed to form activated carbon for dye adsorption. In this study, paper sludge was pyrolyzed under nitrogen atmosphere at 600 oC 1 hr. Then, sample was washed with 1 M HCl and DI water, and dried in an oven. The zeta potential measurement of adsorbent showed that the isoelectric point of paper sludge derived activated carbon was around 3 which meant PR should be adsorbed well below pH 3 and that of MB was in neutral or alkali solution. The effect of pH on adsorption, isotherm adsorption and kinetic adsorption were examined to realize the adsorption behavior of paper sludge derived activated carbon. The results of adsorption in different pH condition were conformed to the results of zeta potential. The data of isotherm adsorption experiment revealed that the adsorption behavior can be described by Langmuir equation well and the maximum adsorption capacities of MB and PR were 119.1 mg/L and 65.8 mg/L. Kinetic adsorption revealed that the adsorption of two dyes were fitted pseudo-second-order model well, and the activation energy of MB and PR adsorption were 8.66 and 2.47 kJ/mol.

In gas-condensate reservoirs, gas productivity declines due to the increasing accumulation of liquids in the near wellbore region as the bottom-hole pressure declines below the dew point pressure. This phenomenon occurs even in reservoirs containing lean gas-condensate fluid. Various methods were addressed to remediate the productivity decline, for example, fracturing, gas injection, solvent injection and chemical treatment. Among them, gas injection techniques have been used as options to prevent retrograde condensation by vaporizing condensate and/or by enhancing condensate recovery in gas-condensate reservoirs. It is of utmost importance that the behavior of liquid accumulation near the wellbore should be described properly as that provides a better understanding of the productivity decline due to the originated from impaired relative mobility of gas. In this research, several gas injection techniques were assessed by using compositional simulators. The feasibility of different methods such as periodic hot gas injection and gas reinjection using horizontal wells were assessed using different reservoir fluid and injection conditions. It is shown that both the temperature and composition of the injection fluids play a key role in the remediation of productivity and condensate recovery. The combined effect of these parameters were investigated and the resulting impact on gas and condensate production was calculated by numerical simulations in this study. Design parameters pertaining to field development and operations including well configuration and injection/production scheme were also investigated in this study along with the above parameters. Based on the results, guidelines on design issues relating gas injection parameters were suggested. The various simulation cases with different parameters helped with gaining insight into the strategy of gas injection techniques to remediate the gas productivity and condensate recovery.
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碩士
國立交通大學
電機工程學系
103
Low voltage Wi-Fi system needs well-regulated supplying power system even in case large load step change. Well-regulation supplying power system needs suppressed output voltage variation including minimized transient undershoot/overshoot voltage variation, steady state voltage variation, and offset voltage effect. State-of-art techniques directly dissipate redundant energy at the output when load changes from heavy to light. Contrarily, proposed multi-phase suppressing output overshoot voltage (MP-SOOV) technique with the help of bond-wire inductance of 33nH has 81.3% overshoot voltage reduction by energy recycling technique and thus simultaneously gets extra power of 98mW in case of load change from 1.7A to 0.3A. Moreover, proposed transient enhancement (TE) technique reduces output undershoot voltage and asynchronous auto-zero (AAZ) technique minimizes the offset effect of core devices in advanced process. Experimental results show 93% peak efficiency, 6mV output voltage ripple with all ceramic capacitors, and -6.4dB improvement in error vector magnitude are achieved by the proposed directly supplying power system.

Dissertação de mestrado em Técnicas de Caraterização e Análise Química
Nos últimos anos a incorporação excessiva de materiais poliméricos na indústria como forma de substituição de materiais convencionais tem levado à acumulação de grandes quantidades de resíduos devido à sua degradação lenta. Como consequência, surgem problemas ambientais e/ou de saúde causado pelo excesso e resíduos poliméricos. Assim, torna-se muito importante o desenvolvimento de tecnologias que sejam viáveis do ponto de vista ambiental e rentáveis, com vista à redução da quantidade enorme de resíduos poliméricos. Com este trabalho pretendeu-se o desenvolvimento de um método expedito para a quantificação de PP e PE em misturas físicas de materiais que possibilite a validação da qualidade dos resíduos a processar e que ajude na melhoria da qualidade do produto reciclado obtido. Para tal, foram preparadas amostras com diferentes percentagens de PP e PE (100/0, 75/25, 50/50, 25/75, 0/100) por extrusão e analisadas por DSC para determinação da percentagem de cada polímero. Para a validação deste método foram recolhidos materiais, provenientes de embalagens usadas em produtos comerciais com composição variada. Posteriormente estes foram granulados para a obtenção de uma mistura homogénea e determinada a percentagem de PP e PE presenta em cada porção analisada. Foi testado o efeito de zeólitos (NaY e HY) na estabilidade térmica de misturas de PP e PE, uma vez que este tipo de aditivos pode ser uma mais-valia para a sua degradação. No desenvolvimento e implementação de um método para a determinação do calor específico através do DSC foram variadas algumas condições de ensaio, programa de temperatura e conformação da amostra, na perspetiva de determinar quais as condições que conduziriam a resultados precisos e exatos. Adicionalmente foi feito um estudo de otimização e validação de um método para a determinação das coordenadas de cor por espetroscopia de refletância (uso da esfera integradora) baseado na norma ASTM C1510, tendo sido verificada a equivalência entre o método do colorímetro e da esfera integradora através da análise de um padrão e da variação de algumas condições de ensaio.
Over the past years, the high incorporation of polymeric materials in the industry as a form of substitution of conventional materials has driven to the accumulation of large quantities of waste due to its slow degradation process. As a result, environmental and/or health problems arises caused by excess polymer waste. Thus, it is imperative the development of technologies environmentally and economically viable, in order to reduction the enormous amount of polymeric wastes. The main goal of this work is the development an expeditious method for quantification of PP and PE in physical blends of materials, enabling the quality validation of the residues recycling process and helping to improve of recycled product quality. In this regard, different and wellestablished percentages of polypropylene (PP) and polyethylene PE blended samples (100/0, 75/25, 50/50, 25/75, 0/100) were produced by extrusion method and analyzed by DSC for PP and PE content quantification. For the validation of this method several materials from packaging waste used in market products with different polymeric content were collected. The granulated materials, allows to obtain a homogeneous mixture, which different portions were tested by the developed method. The effect of zeolites (NaY and HY) on the thermal stability of PP and PE blend was also studied during this works, since this type of additive could interfere in the polymers degradation behavior. During the development and implementation of the method for determination of the heat capacity by DSC some test conditions, was varied (temperature program and shape of the sample), in order to access what conditions, result in more accurate and exact results. Additionally, it was performed a study of method validation for determination of the color coordinates by reflectance spectroscopy (using an integration sphere) based in the ASTM C1510 standard method. From this study, and using a standard sample and different test conditions, it was verified an equivalence between the colorimetric and integrating sphere methods.

Dissertação de mestrado em Engenharia Urbana
A procura de soluções ambientalmente sustentáveis é um dos temas que atualmente tem sido investigado de forma contínua. Nesse sentido, a produção de materiais de pavimentação a frio é uma solução que vai de encontro a esse objetivo, podendo utilizar-se a tecnologia de betume-espuma, ainda pouco conhecida, para desenvolver materiais estabilizados com esse ligante. De facto, o betume-espuma deve conseguir envolver melhor os agregados a baixas temperaturas. Nesse sentido, o presente trabalho teve como objetivo efetuar um estudo sobre o uso de materiais de pavimentação estabilizados a frio com betume-espuma. Para isso procedeu-se ao estudo de duas soluções distintas, uma com estabilização apenas de material granular e outra com estabilização de material granular juntamente com material fresado, de modo a perceber o comportamento deste tipo de soluções em ambos os casos. Durante este trabalho foi feita uma comparação entre as duas soluções de estabilização referidas (apenas material granular ou material granular juntamente com material fresado). Além disso, fez-se a comparação com outras misturas estudadas em trabalhos anteriores para se avaliar o seu desempenho em relação a misturas já conhecidas. Para a produção de betumeespuma foi utilizado um aditivo devido a falta de estabilidade da espuma. Em seguida, foram realizados vários ensaios para formulação e avaliação do comportamento das misturas estabilizadas com betume-espuma. As misturas estabilizadas com betume-espuma foram ensaiadas para medição da baridade aparente, sensibilidade à água, módulo de rigidez e resistência à fadiga e à deformação permanente. Com base nos resultados obtidos é possível concluir que é viável e muito interessante o uso de materiais estabilizados com betume-espuma. No entanto, é necessário estudar cuidadosamente as condições de produção e otimização dos teores de betume usados, pois é possível passar de soluções muito boas a soluções más ao selecionar um teor em betume-espuma desadequado.
The pursuit of environmentally sustainable solutions is one of the topics that has currently and continuously been investigated. In that sense, the production of cold paving materials is a solution that meets that goal, allowing to use the foamed bitumen technology, little known yet, to develop materials stabilised with this binder. In fact, the foamed bitumen should manage to better involve aggregates at lower temperatures. In this sense, the present work had as its main goal to undertake a study and on the use of stabilised cold paving materials with foamed bitumen. For that, the study of two different solutions was undertaken, one with stabilisation only of granular material and another of stabilisation of granular material together with reclaimed asphalt material, so as to perceive the behaviour of this type of solutions in both cases. During this work, a comparison has been made between the two stabilisation solutions (granular material only or granular material along with reclaimed asphalt material). In addition, a comparison has been made with other mixtures studied in previous works to assess their performance in relation to mixtures already known. For the production of foamed bitumen, an additive was used due to the lack of stability of the foam. Then, several tests were carried out for designing and evaluating the behaviour of mixtures stabilised with foamed bitumen. The blends stabilised with foamed bitumen were tested to measure the bulk density, water sensitivity, stiffness modulus and resistance to fatigue and permanent deformation. Based on the obtained results it can be concluded that the use of road materials stabilised with foamed bitumen is feasible and a very interesting technology. However, it is necessary to carefully study the conditions of production, namely concerning the optimization of the percentages of foamed bitumen used, since it is possible to go from very good solutions to bad solutions when selecting the amount of foamed bitumen inadequately.

碩士
國立臺灣大學
工程科學及海洋工程學研究所
99
In general, the power amplifier ( PA ) is one of the most power-hungry devices in a wireless transceiver. Therefore, the longer the mobile devices can operate when the higher the PA efficiency. Linearity and efficiency are two key parameters to determine the performance of wireless transmitters, so linearity and efficiency must be traded-off in the PA. That is, we got more efficiency while the linearity is decreased. This thesis is a method for improving the efficiency of a balanced PA under load mismatch by recycling the reflected power. The reflected power will be directed to the isolated port of a 90° hybrid coupler. The reflected power can then by rectified and converted back to dc power to assist in supplying the PA. A prototype system was built to validate the concept and tested under various phase angles with 2:1 and 4:1 VSWR using a W-CDMA voice signal at 836.5 MHz. Measurement results show that the power recycling technique improves the overall efficiency by as much as 14.7% and 22.1 % when 2:1 and 4:1 VSWR of the output power level is 25 dBm. The proposed an efficiency improved balanced PA using power recycling technique, we believe our designs are valid and effective directions to achieve improving the efficiency of PAs.

碩士
國立高雄應用科技大學
土木工程與防災科技研究所
96
ABSTRACT The disposition of waste tires remains an important issue in Taiwan as the population and corresponding number of waste tires continues to rise. Stockpiling or landfilling of scrap tires has negative environmental impacts and may not be the most efficient disposal solution. The Government has initiated policies to encourage diversion of waste tires to other applications such as crumb rubber products, civil engineering projects, and tire-derived fuel etc. Water jet cutting has a great potential of being an effective and sustainable manufacturing technology. Advantages such as clean cut edges, high accuracy, flexibility, low material loss, inert and abundant main processing substances (water, sand) and negligible thermal influence on the work piece. The objective of this study is to assess the technological environmental, and economic features of the application of high power water jet to process waste tires. Using high pressure water jets, tires can be shredded into a fine powder. The resulting powder can be reused as a filling material for new tires. From an economical and ecological point of view, this process is clearly a better solution than burning tires as well as a great extension of the life span of the tire particles. The product of this process can also be refined: Tire powder is very valuable because of its capability to augment certain properties of plastics, for example impact strength. The concept of using high power water jet to crush old tyres into a fine powder is unique. Technique feasibility research and literature studies show that nobody in the world seems to be working on topics associated with crushing using water jet technology. Preliminary experiments in November 2006 confirmed that it is possible to produce that rubber powder using special water jet nozzle systems. We have developed new high performance water jet nozzles for operation at pressures of a few thousand bars. Using this nozzle type, recycling procedures such as the one mentioned above become feasible without using of abrasive auxiliary compounds. This new technology also facilitates the shredding of similar compounds, such as plastics of all kind, and opens a new door to exciting activities such as the production of coal dust, the demolition of concrete ruins and nuclear power stations without the costly mechanical treatment with pressure hammers, the cleaning of railway systems and airports etc. Keywords：waste tire、water jet、rubber powder、grain distribution curve

碩士
國立交通大學
電機學院電子與光電學程
100
The charge recycling match (CRM) technique is proposed to reduce dynamic power dissipation in display column drivers. The CRM technique can save much power in same polarity operations, which are not easy to have charge recycling in conventional techniques. Theoretical analysis and simulation result show maximum dynamic power reduction of 12% and 30% in column inversion panel with R/G/B stripe pixel arrangement and Zigzag panel, respectively. The proposed method is suitable for voltage mode driving scheme and capacitive loading display column driver. Specially, it also works in thin-film-transistor (TFT) liquid crystal displays (LCDs) and active mode organic light-emission-diode (AMOLED) display. A complete method application including circuit structure, principle, and operation flow are demonstrated in TFT-LCD application. The software provides the theoretical analysis. Besides, the Hardware resource of implementation is implemented by RTL and tested by FPGA to show the correctness of the proposed technique.

碩士
大葉大學
電機工程研究所
90
To reduce the power consumption of the TFT-LCD column driver，a novel multi-phase charge-recycling technique that doesn’t require any external capacitor for charge conservation is proposed. Based on this method, the voltage swing is reduced to (1/2n + 1/4)VSWING, where “n” is the number of data lines in one group. If n is larger, voltage swing will become smaller in order to achieve lower power consumption goal. Comparing with original circuit (without any charge-recycling) and charge sharing one, the proposed method can reduce the power consumption about 65.7% ~ 13.3% respectively for n=8.

碩士
國立屏東科技大學
環境工程與科學系所
103
The study used CFD simulation software (Gambit and Fluent) to simulate a hydrothermal environment, and a hydrothermal reactor to treat general and hazardous industrial wastes in order to investigate the effectiveness of hydrothermal treatment. The hydrothermal method was used as a powerful recovery technique of wastes. In the simulation of hydrothermal reaction, at the initial phase (0 minute), the pressure generated from the bottom and gradually pressurized to 3 atm. In middle stage (60 minutes), vapor generation rate was faster than the coagulation, so the pressure on the interface of bottom was slightly higher than the top of the reactor at 20.9 atm. In later stage to the final stage (simulation time in 80 to 90 minutes), the vapor pressure tended to be balanced, with an internal pressure of 20.0 atm. At this stage, this balance was observed as a stable dynamic balance. The hydrothermal method was used to recover yttrium of phosphor. The yttrium content of phosphor was 2.85 weight %. The recovery effect of using hydrochloric acid increased to 57.46 weight %. When mixing hydrochloric acid and oxalic acid to treat phosphor, it was found that oxalic acid with the calcium of phosphor formed large amounts of calcium oxalate precipitation, and small amounts of precipitated niobium and neodymium. This was observed to cause difficulty in yttrium recovery. To synthesize zeolites, the aluminum slag and waste glass powder as material in alkaline solution was carried out by using the hydrothermal method. From the SEM/EDS, XRD, FI-IR analysis and BET tests, the results probed the method to be effective. The best condition to synthesize samples was at 150 ° C / 5M NaOH / 2 hours. At 120 °C low-temp hydrothermal method to remove arsenic in soil with conditions of hydrothermal treatment, did not change the properties and crystal phase in the soil. The SEM / EDS analysis showed that low-temp hydrothermal conditions did not cause changes of properties and crystal phase in the soil. By using atomic absorption spectrometry to determine the concentration of arsenic in soil, the result showed that arsenic can be removed at 92.7% from soil. In the hydrothermal leaching of heavy metals in fly ash, the best hydrothermal condition of removing lead was operated at a temperature of 90 ° C. The best solvent was deionized water, and the leaching rate of lead was up to 68.98%. Under hydrothermal conditions, the removal effect decreased when temperature increased. The effect of high-temp hydrothermal leaching of heavy metals in fly ash is ineffective.

碩士
國立交通大學
電機學院碩士在職專班電機與控制組
98
The field sequential color (FSC) technology with RGB-LED backlight modules can achieve high color saturation and better color gamut compared to conventional cold cathode fluorescent lamp (CCFL) backlight. Owing to the remove of color filter, the display brightness can be promoted to about three times that of the original one with color filter. Besides, both display power consumption and cost can be decreased greatly due to the disappearance of color filter. The proposed energy-recycling (ER) technique for the FSC display with RGB-LED backlight modules can dynamically switch the output voltage to 36 V for twelve green/blue LEDs in series or 24 V for twelve red LEDs in series according to each color sequence in the FSC technique. As a result, it can reduce 13% of total energy during the red color display period. The current commercial chip can’t satisfy all the functions in the ER technique; thus, a fabricated ER-controller with a commercial IR-2184 driver, which is used to drive independent high/low side power MOSFET with a fixed dead time, synchronous rectification (SR) control function, can implement the ER technique to meet the basic requirement of system. The ER control, which is used to replace the commercial AC-DC converter control further, can operate at the boundary current mode (BCM) with a zero current detection (ZCD) function to trigger the next switching cycle. The ZCD function is achieved by the enhanced current sensing (ECS) circuit, which can satisfy the need of system control to prove the feasibility of the ER technique. The proposed ER technology can accelerate the settling time of the output voltage since the energy that needs to be dissipated by load or leakage is stored to an energy-recycling capacitor from the output capacitor when the driving voltage is switched from 36 V to 24 V; that is it can further reduce 17% of dissipation energy. Specially, it only uses one recycling capacitor and one Schottky diode connected at the power structure of synchronous buck-boost converter.

Tese de Doutoramento (Programa Doutoral em Engenharia Civil)
As questões ambientais assumem um papel essencial para a sociedade atual, e nesse sentido, o desenvolvimento de novas tecnologias que permitam melhorar a sustentabilidade da indústria de pavimentação é cada vez mais pertinente. Dado que, nos países desenvolvidos, a maior parte dos trabalhos realizados nessa área consistem na reabilitação de pavimentos, existe a necessidade de adaptar essa atividade à economia circular, reutilizando os materiais existentes no pavimento quando este atingir o final do seu ciclo de vida. Assim, a reciclagem de misturas betuminosas tem vindo a assumir um interesse crescente da comunidade científica, pelo seu papel fundamental na redução do consumo de recursos naturais e da produção de resíduos. Nesse sentido, atualmente procura-se maximizar a taxa de incorporação de materiais fresados de pavimentos em novas misturas betuminosas, o que traz novos desafios ao nível da sua produção. De facto, para atingir essas taxas é necessário utilizar temperaturas muito elevadas, às quais estão associados consumos de energia e emissões de gases de efeito de estufa significativos. Para minimizar esses efeitos existem tecnologias que permitem reduzir a temperatura de produção, que podem ser aplicadas juntamente com a reciclagem de elevadas quantidades de material fresado, das quais se destaca a tecnologia de betume-espuma. Esta utiliza apenas com uma pequena quantidade de água para expandir o betume, reduzindo a sua viscosidade de forma a envolver adequadamente os agregados a temperaturas muito inferiores. Tendo em conta os desafios anteriores, a presente tese tem como objetivo realizar um estudo detalhado sobre a reciclagem de misturas betuminosas com elevadas taxas de incorporação de material fresado (até 50 %), com grande enfoque na utilização da tecnologia de betume-espuma como solução para minimizar a temperatura de produção das misturas recicladas. Além disso, também se pretende avaliar a utilização de rejuvenescedores em misturas recicladas produzidas a quente, como solução que pode ser utilizada de forma mais generalizada quando não for possível usar a tecnologia de betume-espuma. No decorrer dos trabalhos começou por efetuar-se uma análise completa do material fresado, para uma incorporação mais eficaz em misturas betuminosas recicladas. Depois estudou-se a utilização de rejuvenescedores para melhoria do desempenho de misturas recicladas a quente com 30 e 50% de material fresado. Em seguida estudou-se a tecnologia de betume-espuma em detalhe de forma a contribuir para um maior conhecimento na sua aplicação em misturas recicladas. O estudo desta técnica incluiu a avaliação das propriedades de expansão e das curvas de decaimento do betume-espuma, bem como a determinação da redução da temperatura de produção com ensaios de compactabilidade, para se conseguir determinar as melhores condições de produção destas misturas. Por último, procedeu-se à análise de desempenho das misturas recicladas com betume-espuma, que foi comparado com o das misturas equivalentes produzidas a quente, e procedeu-se à aplicação da tecnologia de betume-espuma em central. No final deste estudo, foi possível obter misturas com betume-espuma e com incorporação de elevadas taxas de reciclagem (30 e 50%), produzidas a temperaturas significativamente mais baixas (temperatura dos agregados diminuiu entre 20 e 40 °C), mas com um desempenho idêntico ao das misturas produzidas a quente. Adicionalmente, para as misturas betuminosas recicladas a quente concluiu-se que o uso de rejuvenescedores não é necessário para taxas de reciclagem até 30%, mas é aconselhado (2 a 3%) ao incorporar 50% de material fresado.
Nowadays, the environmental issues play a key role for the society, and thus, the development of new technologies to improve the sustainability of the paving industry is increasingly relevant. Given that, in developed countries, most of the work carried out in this area is related to pavement rehabilitation, there is a need to adapt this activity to the circular economy, reusing pavement materials when it reaches the end of its life cycle. Therefore, recycling of asphalt mixtures has assumed an increasing interest of the scientific community, due to its fundamental role in reducing the consumption of natural resources and the production of waste. Taking the abovementioned into account, maximization of reclaimed asphalt pavement material incorporation rates into new asphalt mixtures is currently being targeted, which presents new production challenges. In fact, to achieve these rates, it is necessary to use very high temperatures, which are associated with significant energy consumption and greenhouse gas emissions. To minimize these effects, there are technologies that allow the reduction of the production temperature, which can be applied together with the recycling of high quantities of reclaimed asphalt pavement material, of which foamed bitumen technology stands out. It uses only a small amount of water to expand the bitumen, reducing its viscosity in order to properly coat the aggregates at much lower temperatures. Considering the previous challenges, this thesis aims to carry out a detailed study on the recycling of asphalt mixtures with high reclaimed asphalt pavement incorporation rates (up to 50%), with a great focus on the use of foamed bitumen technology as a solution to minimize the production temperature of the recycled mixtures. In addition, it is also intended to evaluate the use of rejuvenators in hot-recycled blends, as a solution that can be more widely used when foamed bitumen technology cannot be used. In the course of the work, a complete analysis of reclaimed asphalt pavement material was made, for a more efficient incorporation in recycled asphalt mixtures. Then, the use of rejuvenators was studied to improve the performance of hot recycled mixtures with 30 and 50% of reclaimed asphalt pavements. Next, foamed bitumen technology was studied in detail in order to contribute to a better knowledge of its application in recycled mixtures. The study of this technology included the evaluation of the expansion properties and the decay curves of the foamed bitumen, as well as the assessment of the production temperature reduction based on compactability tests, in order to determine the best production conditions for these mixtures. Finally, the performance of the recycled mixtures with foamed bitumen was evaluated and compared with that of equivalent hot mixtures, and the foamed bitumen technology was tested in an asphalt plant. At the end of this study, it was possible to obtain asphalt mixtures with foamed bitumen incorporating high recycling rates (30 and 50%), produced at significantly lower temperatures (aggregate temperature decreased between 20 and 40 °C), but with a similar performance to that of hot mix asphalts. Additionally, for hot recycled asphalt mixtures it was concluded that the use of rejuvenators is not required for recycling rates up to 30%, but it is expected to be used (2 to 3%) when incorporating 50% of reclaimed asphalt pavements.
Este trabalho foi financiado pelo Governo de Portugal e pelo Fundo Social Europeu da União Europeia (UE/FSE) através da Fundação para a Ciência e Tecnologia (FCT) com a Bolsa de Doutoramento SFRH/BD/85448/2012, e no âmbito do Programa Operacional Potencial Humano inscrito no Quadro de Referência Estratégico Nacional (POPH/QREN) para o período 2007-2013, assim como no âmbito do projeto “Eficiência Energética e Ambiental das Misturas Betuminosas e Redução das Emissões de Gases de Efeito Estufa (QREN-SI 090528), atribuído à empresa Betominho, Sociedade de Construções S.A., do grupo MonteAdriano, com a colaboração da Universidade do Minho.