Esse trabalho teve como objetivo avaliar a viabilidade técnica e econômica da regeneração de coagulantes a partir do lodos gerados em ETA\'s. Foi considerado que o coagulante regenerado será empregado em sistemas de tratamento de esgotos. A regeneração de coagulante consiste basicamente em promover uma alteração no pH do lodo, de forma que os hidróxidos metálicos presentes são solubilizados. A fase líquida com alta concentração de metais é então separada, constituindo o coagulante regenerado. Consequentemente, essa tecnologia propicia a recuperação de um recurso, que é o coagulante, e a redução de lodo. Para a verificação da viabilidade técnica foram realizados ensaios de acidificação em escala de bancada com lodos das ETA\'s Guaraú e Rio Grande, visando o estudo das condições de regeneração, da qualidade do coagulante produzido e do lodo restante. Foi verificado que do ponto de vista técnico a regeneração de coagulantes é uma alternativa possível, gerando um coagulante aproximadamente 100 vezes mais diluído que os comerciais, mas com desempenho satisfatório na aplicação no tratamento de efluentes de reator UASB. As reduções médias de sólidos em suspensão nos lodos utilizados foram de 28% e 53%. A avaliação econômica foi realizada considerando uma ETA com características similares à ETA Rio Grande, com um sistema de regeneração em funcionamento. Foi verificado que considerando as reduções de custos decorrentes da diminuição de lodo a ser tratado e disposto, o custo de produção do coagulante regenerado é muito próximo ao custo do coagulante comercial. Portanto, conclui-se que hoje em dia essa tecnologia deve ser considerada como uma alternativa potencialmente viável dos pontos de vista técnico e econômico para o tratamento e reaproveitamento de lodo de ETA\'s. / The primary goal of this work was to evaluate the technical and economical feasibility of coagulant recovery from water treatment plant sludges, considering that the recovered coagulant is going to be used in wastewater treatment plants. The coagulant recovery technology consists in change the sludge pH, in order to solubilize the present metal hydroxides. The liquid phase with high metals concentrations is then separated, becoming the recovered coagulant. This technology provides a resource recovery, which is the coagulant, and also a reduction in the amount of sludge that needs to be treated and disposed. To verify the technical feasibility, acidification bench tests were conduced using sludges from Guaraú e Rio Grande water treatment plants, in order to study the regeneration conditions, the recovered coagulant quality and the remaining sludge. From the technical point of view, it was verified that coagulant recovery is a possible alternative, producing a coagulant 100 times more diluted than the commercial coagulant, but with a satisfactory behavior in the treatment of UASB reactor effluent. The suspended solids average reductions in the Rio Grande and Guaraú water treatment plants sludges were 53% and 28%, respectively. The economical evaluation was done using the results obtained in the bench tests and considering a water treatment plant similar to Rio Grande. It was verified that considering the costs decrease due to the sludge reduction, the recovered coagulant production cost was very similar to commercial coagulants cost. Thus, it was concluded that nowadays this technology must be considered as a potential alternative for the treatment and reuse for water treatment plant sludges, regarding to the technical and economical aspects.

Small organic ‘collector’ ligands play an important role in the recovery of platinum group minerals (PGMs) from the industrial platinum mining process via the froth flotation process, which separates finely ground minerals on the basis of relative hydrophobicity. Design of novel ligands to improve PGM recovery is an ongoing industrial interest. This thesis involves the application of computational chemistry techniques to gain a first-principles understanding of simple mineral-collector ligand interactions, with a view to applying this understanding to the design of novel collector ligands. Experimental techniques are also used, where appropriate, to validate computational modelling in order to gauge the applicability of computational chemistry to this field. Sperrylite (PtAs2), the world’s most common PGM, was used as a model for a typical platinum group sulfide mineral. Pentlandite ((Fe,Ni)9S8) and pyrite (FeS2), two base metal sulfide minerals commonly associated with PGMs, were used as competitor surfaces to gauge collector selectivity. α-quartz (SiO2) was used as to model silicaceous waste material, and pure platinum (Pt) as an internal standard to gauge Pt-collector interactions. Chapter 1 provides an overview of PGM mining with particular focus on the froth flotation process. A brief overview of the computational methods applied in this work is provided in Chapter 2. Chapter 3 presents modelling work based on assessing the various mineral and metal surfaces upon which ligands adsorption is modelled. Stable ‘working surfaces’ are defined by calculating surface energies for various low Miller index cleavages of the bulk unit cells of these solids. Surface stability with respect to slab depth is also assessed. A number of methods, including application of the virtual crystal approximation, a pairwise cluster expansion and explicit site modelling, are used to resolve the issue of positional disorder of the metal sites in pentlandite. This leads to the observation that pentlandite slabs with a higher concentration of Ni atoms at the mineral/vacuum interface are more stable. A global minimum energy bulk unit cell of pentlandite is described. Chapters 4 and 5 deal with the adsorption of collector and aqua ligands onto these surfaces, with Chapter 5 also reporting attempts at rational in-silico ligand design. A novel method for calculating the binding energy of anionic species in periodic systems via a work-function based correction is described and tested for both mono- and dianionic species. Modelling of ethyl xanthate (H5C2OCS2-) and xanthate-based analogues (H5C2XCS2-, where X=N, NH, NC2H5, S, CH, CH2) shows a trend of increased binding strength upon formation of dianionic species. Whilst this observation was supported (to a lesser degree) by geometrical parameters, the extension of the work-function based correction to deal with dianionic species tended to significantly overbind these ligands and so the work function correction was found to be inappropriate for use in models with a charge state greater than -1. Modelling of heterocyclic ligands on selected surfaces shows weaker adsorption than non-heterocyclic species due to unfavourable electronic effects of the delocalised heterocycle on the R-CS2- head group. Efforts in ligand design focussed on optimising the electronic properties of the tail group in the xanthate structure to provide maximum electron density to the CS2- system. The output from this process was p-methoxyphenyl dithiocarbamate (H2CO-C6H4-N=CS2²-), which performed well in computational models. Synthesis of this ligand, as well as protonated Nethyl dithiocarbamate (H5C2NHCS2-) failed, however, due to the intrinsic instability of monosubstituted dithiocarbamates. Attempts to validate modelling results using two experimental techniques are reported in Chapter 6. Firstly, cyclic voltammetry experiments using sperrylite, pentlandite and platinum working electrodes suspended in collector solutions of concentration 1x10-3 M are reported, which show some correlation between the order of calculated binding energies and the relative position of the oxidation potential for the formation of disulfide oxidation products, a process which is affected by surface adsorption. Correlation is best for ethyl xanthate and diisobutyl dithiophospinate, but poor for N,N-diethyl dithiocarbamate ((H5C2)2NCS2-). Secondly, microflotation experiments for the recovery of sperrylite, pentlandite and pyrite using various collector ligands were conducted. Results broadly agree with prior microflotation literature, but show no simple correlation between ligand binding energies and flotation recovery, suggesting that more complex factors than simple ligand/mineral adsorption are involved.

Aims: To explore and inform current water immersion recovery practice of high performance athletes; and to compare recovery interventions of 5 minutes cold water immersion, warm water immersion and passive rest, in trained subjects, following intense exercise replicating the demands of game-sports. Methods: Study 1: In a repeated measures design, a measurement approach for use in the evaluation of water immersion efficacy was piloted. The within-day and between-day reliability of surface electromyelography (sEMG), particularly functional wavelet analysis, was evaluated in human lower limb muscles. Functional wavelet analysis provides the opportunity to measure neuromuscular function at the greatest level of detail by differentiating the relative intensity of low and high frequency motor unit recruitment. On 2 consecutive days (Trial 1 & Trial 2), 12 participants performed 3x5 second isometric 80% maximal voluntary contractions (MVC) on a Biodex® dynamometer in each of 150 ankle plantarflexion, 200 knee extension and 200 knee flexion. sEMG was obtained from the medial gastrocnemius (MG), vastis medialis (VM), vastis lateralis (VL) and biceps femoris (BF) muscles. Joint position and force production were controlled. Electrodes remained in situ during each trial. Electrodes were removed upon completion of Trial 1 and replaced in the same position the next day for Trial 2. Simultaneous sEMG metrics for intervals of consistent force production were compared between contractions in Trial 1 and Trial 2 (between-day) and contractions within Trial 2 (within-day). Study 2: 11 trained participants completed the 90 minute Loughborough Intermittent Shuttle Test (LIST). Five minutes of COLD water immersion (8.8 ± 0.30C), WARM water immersion (35.1 ± 1.80C) and REST were compared in a repeated measures randomised cross over design. Recovery was evaluated at 2, 4 and 24 hours post exercise using circulating markers of muscle damage, muscle dynamometry, drop jump and repeated single leg hop performance tests and perceived recovery. Study 3: Current water immersion practice of high performance athletes, practice implications stemming from this study’s findings, and the rationale were explored. In a purposive, theoretical sampling approach of expert consultation, 8 professionals advising internationally competing athletes on water immersion recovery practice were provided with a research brief of this project in advance of a scribed, semi-structured interview. Participants were of Sports Coach, Strength & Conditioning Coach and Sports Physiotherapist professions with a minimum of 5 years’ experience working with internationally competing athletes; and differed in international location and sporting disciplines.

Each year, millions of tons of non-ferrous scrap metal are discarded in the US. This metal is wasted due to a lack of proper recovery methods. Recent developments in spectroscopic technology have made it possible to identify the waste composition of scrap metal in real-time. This has opened the door for high-speed automated metal sortation and recovery, especially for the recovery of high value precious metals, such as titanium, nickel, cobalt, molybdenum and tantalum. Automated sortation systems typically consist of three main phases: (i) Feeding of material, (ii) Composition identification, and (iii) Physical separation. Due to their low volume and industry fragmentation, high-strength precious metal chips usually come in the form of chips smaller than 10 mm. Therefore it is extremely difficult to feed metal chips individually into the sorting system. At CR3, a new feeding mechanism was invented and developed in order to provide single layer feeding of small metal chips. A laboratory-scale prototype was built and proven to be feasible, scalable and reliable. A model was developed to predict the output of feeding variables based on initial input parameters. An operation window of the process was also defined for various metal chip resources. These will be presented, reviewed and discussed in the following paper.

In situations of mass disaster (1), which include airline crashes (2), terrorist attacks (2), large fires (3), and mass homicide (4), the human remains are often damaged beyond recognition (5). In these cases, bones and teeth are potentially the only acceptable source of deoxyribonucleic acid, or DNA (6). Previous studies have evaluated a plethora of techniques to purify DNA from hard tissue, but there is no consensus on the optimal process by which to extract and purify DNA from these samples. Not only are hard tissue samples difficult to process, in many cases the samples are subjected to extreme environmental conditions, such as high temperature. Thus, there is interest in obtaining information on DNA quality from samples exposed to high temperatures (7). This work hopes to fill the gap by: 1) optimizing a DNA extraction protocol from hard tissue; and 2) measuring the degree to which the DNA is degraded in an effort to link the quantity and quality of the DNA recovered to the outer appearance of the tooth. To accomplish this, individual teeth were burned in a furnace at 100 °C, 200 °C, 300 °C, 400 °C, 500 °C, and 600 °C for 10, 20, and 30 minutes. The optimal extraction procedure utilized Amicon® Ultra-4 Centrifugal 30K filter devices and the QIAGEN MinElute Polymerase Chain Reaction (PCR) Purification Kit. Samples were quantified using the Quantifiler® Trio quantification kit to obtain the quantity and quality metrics. After heat exposure, each tooth was photographed and subsequently given a color designation or value: light yellow to beige teeth were assigned a value of 1; dark yellow to orange were assigned a value of 2; brown was assigned a value of 3; shiny black was assigned a value of 4; and black to light gray teeth were assigned a value of 5. Both carbonization and the early stages of calcination were observed. The mass of DNA per mass of tooth was determined by examining quantitative PCR (qPCR) results for both a large and small autosomal fragment. The degradation index, or DI, was also calculated from qPCR measurements. The results demonstrate a strong correlation between the quantity of DNA recovered, the quality of the DNA obtained, and the designated color value. The highest recovery rates were obtained from teeth assigned a color value of 1 (unaltered beige) or 2 (yellow to orange). These teeth were exposed to either room temperature, 100 °C or 200 °C. At temperatures exceeding 300 °C, the amount of DNA recovered drastically decreased and was inconsistent. Some of the samples subjected to temperatures at and above 300 °C resulted in no quantifiable DNA. In contrast, the DI results suggested that when the teeth were subjected to temperatures ≤ 100 °C, the quality of the DNA was good, wherein the DI value was approximately 1. At 200 °C, the temperature began to impact the DI value, which increased with time to the point where a DI was no longer able to be calculated because the large autosomal fragment could not be detected. In conclusion, the current work compares five different methods of DNA extraction to establish a best practice extraction procedure for these difficult samples. Furthermore, this work suggests that examination of the tooth’s appearance can be used to deduce whether successful DNA recovery is likely. In summary, the results demonstrate that when the tooth sample was assigned a color value of 1, the quantity and quality of the DNA obtained was high. Once the color value of the sample rose to 2, the quantity and quality of DNA varied greatly and the probative value of the sample was diminished. Samples that exhibited large color changes or had begun the calcination process resulted in no recoverable DNA.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / by Rahmatallah Shoureshi. / Ph.D.

Este trabalho de pesquisa foi elaborado com o objetivo de apresentar os resultados da recuperação e reciclagem de xileno, gerado em laboratórios de análises clínicas. É importante salientar a importância de um programa de gestão e gerenciamento de resíduos químicos, principalmente em instituições de ensino e pesquisa, de forma a contribuir para a preservação do ambiente e possibilitar a formação de profissionais conscientes, acostumados à práticas corretas de gestão e gerenciamento de resíduos químicos. A recuperação do resíduos de xileno foi feita por meio da técnica de destilação fracionada. Para a verificação da eficiência da recuperação do xileno, foram analisadas amostras do resíduo de xileno, do xileno recuperado e do xileno padrão, com o propósito de comparar os resultados obtidos destas amostras por meio das análises de Espectrofotometria de ultravioleta visível, (UVVis), Refratometria, Cromatografia Gasosa (CG) e Cromatografia Gasosa acoplada à Espectrometria de Massas (CG-EM). Os resultados desta pesquisa confirmam a eficiência da recuperação do resíduo de xileno, possibilitando que este retorne ao processo produtivo ou gerador, na forma de produto, refazendo assim, o ciclo por completo. A recuperação do resíduo do xileno e sua reciclagem traz benefícios ambientais e econômicos. / This research was elaborated with the objectives to present the results of recovery and recycling of xylene, generated in clinical analyses laboratories. It is essential to point out the importance of management and chemical waste management program, especially in education and research institutions, contributing to environment preservation and to making possible the qualification of conscientious professionals, used with correct practices of management and the chemical waste management. The xylene waste was recovered by fractional distillation technique. To verify the efficiency of the xylene recovery it was analyzed samples of waste xylene, recovered xylene and standard xylene, to compare the obtained data of these samples through the ultraviolet-visible Spectrophotometry (UV - Vis), Refractometry, Gas Chromatography (GC) and connected Gas Chromatography to the Spectrometry of Mass (GC-MS) analyses. The results of this work confirmed the efficiency of the xylene recovery, making possible its return to the productive or generator processes as a product, thus completing the entire cycle. The recovery of the xylene waste and its recycling has important ambient and economic benefits.

This thesis presents the MicroBooNE search for the MiniBooNE low energy excess using a fully automated image based data reconstruction scheme. A suite of traditional and deep learning computer vision algorithms are developed for identification of charge current quasi-elastic (CCQE) like muon and electron neutrino interactions using the MicroBooNE detector. Given a model of the MiniBooNE low energy excess as due to an enhancement of electron neutrino type events, this analysis predicts a combined statistical and systematic 3.8σ low energy signal in 13.2 × 1020 POT of MicroBooNE data. When interpreted in the context of νμ → νe 3 + 1 sterile neutrino oscillations a best fit point of (∆m241, sin2 2θeμ) = (0.063,0.794) is found with a 90% confidence allowed region consistent with > 0.1 eV2 oscillations

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Architecture; and, (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1986. / Typescript (photocopy). / Includes bibliographical references (v. 2, leaves 288-292) / A study of the energy system at the Massachusetts State Transportation Building was conducted. This innovative energy system utilizes internal-source heat pumps and a water thermal storage system to provide building heating and cooling. The potential benefits of this type of system include both energy savings and operating and equipment cost savings when compared to more conventional building heating and cooling systems. The study involved monitoring of equipment performance, computer simulation of the building energy system dynamics, and analysis of actual and modelled system efficiency. It was found that the building is presently operating as a 'low energy' building, despite a number of factors which have limited the heat pump system's capability to entirely meet winter heating requirements. Significant additional operation efficiency and cost savings are potentially available if a variety of measures are undertaken, including: stratification of the thermal storage system, utilization of demand management controls, and increased lighting system efficiency. / by Abbe Ellen Bjorklund. / M.S.

Cerâmicas à base de zircônia tetragonal estabilizada com ítria (ZrO2(3%Y2O3)) possuem excelentes propriedades mecânicas, devido a uma peculiar transformação de fases que ocorre nos grãos desta cerâmica durante o crescimento de uma trinca. O crescimento da trinca gera tensões compressivas sobre os grãos tetragonais metaestáveis, os quais se transformam em monoclínicos, promovendo uma expansão volumétrica de 3 a 5%, a qual impede que a trinca continue crescendo nas condições de carregamento mecânicos inicialmente utilizados, o que produz aumento da resistência à fratura, e tenacidade deste material. Neste trabalho são apresentados os resultados do estudo da recuperação da fase tetragonal pela utilização de tratamentos térmicos, em zircônia envelhecida por desgaste, durante a preparação de próteses dentárias. Blocos cerâmicos pré-sinterizados à base de ZrO2(3%Y2O3) foram sinterizados em três condições distintas, quais sejam, 1450°C - 0h, 1530°C - 2h e 1600°C - 4h. Cada lote de amostras sinterizado foi submetido análise de densidade relativa, difração de raios X (DRX) e microscopia eletrônica de varredura (MEV). Parte das cerâmicas sinterizada foi fraturada, e a superfície de fratura foi re-examinada por DRX e MEV. Outra parte foi fragmentada visando a transformação martensítica, que gera a fase monoclínica no material, e em seguida caracterizada por DRX. Os resultados da densificação e análise microestrutural indicaram densidade relativa de 94,2%, 99,6% e 99,75%, tamanho médio de grão de 0,28?m, 0,49m e 1,31m, para amostras sinterizadas a 1450°C - 0h, 1530°C - 2h e 1600°C - 4h respectivamente. Após fragmentação, os teores de fase monoclínica medidos foram da ordem de 58%, 43% e 4,5% que correspondem a aproximadamente 65% vol, 50% vol e 6% vol. Tratamentos térmicos realizados a 950°C, 1100°C e 1200°C foram necessárias para recuperação de 100% de fase tetragonal, em amostras sinterizadas a 1450°C - 0h, 1530°C - 2h e 1600°C - 4h, respectivamente. / Tetragonal zirconia-based ceramic stabilized with (ZrO2(3%Y2O3)) have excellent mechanical properties due to a peculiar phase transformation that occurs in this ceramic grains during the growth of a crack. The crack growth generates compressive stresses on the metastable tetragonal grains, which are transformed into monoclinic, promoting a volumetric expansion of 3 to 5% which prevents the crack continues to grow under conditions of mechanical loading initially used, which produces the increased fracture strength and toughness of this material. This paper presents results of the recovery of the tetragonal phase by the use of thermal treatments in zirconia aged for wear during the preparation of dental prostheses. ZrO2(3%Y2O3) pre-sintered ceramic blocks were sintered in three different conditions: 1450°C-0h, 1530°C-2h and 1600°C-4h. Sintered samples were characterized by relative density, X-Ray diffraction (XRD) and Scanning Electron Microscopy (SEM). Part of the sintered samples was fractured and the fracture surface was re-examined by XRD and SEM. Another part was milled aiming generates a martensitic transformation (monoclinic phase), and characterized by XRD. The results of densification and SEM analysis indicates relative density of 94.2%, 99.6% and 99.75%, average grain size of 0.28?m, 0.48m and 1.31m, for samples sintered at 1450°C-0h, 1530°C-2h and 1600°C-4h respectively. After milling, the monoclinic phase content was 58%, 43% e 4,5% corresponding to 65% vol, 50% vol e 6% vol. For samples sintered at 1450°C-0h, 1530°C-2h e 1600°C-4h, heat treatments of 950°C, 1100°C and 1200°C were performed respectively, for recuperation of 100% of tetragonal phase.