Klimatförändringar är en av de viktigaste problemen som påverkar framtida generationer. För att bekämpa detta införlivar Northvolt hållbara metoder genom hela batteriproduktionsprocessen. Ett avgörande steg i elektrodtillverkningen är slurryblandningen, vilket innebär att man kombinerar flera pulver inklusive det aktiva materialet. Det aktiva materialet doseras in i mixern med hjälp av pulverdoseringsutrustning. En omfattande studie har genomförts på pulverdoseringsutrustningen för att minska produktionstiden och förbättra kvaliteten på slurryn. Efter att ha förstått utrustningens funktioner och genomfört inledande tester på både anoden och katoden, föreslogs nya justeringar. Med de nyligen genomförda justeringarna observerades en betydande minskning av produktionstiden med 50 % i anoden och därför minskade även energiförbrukningen vid dosering. Det är viktigt att notera att stora skillnader mellan anod och katod observerades på grund av olika kemikalieanvändning. Slutligen har denna studerade framgångsrikt uppnått en minskning av produktionstid och energiförbrukning genom att optimera pulverdoseringsutrustningen som används i anod. / Climate Change is one of the main concerns affecting future generations. To combat this, Northvolt incorporates sustainable practices throughout the battery production process. One crucial step in electrode manufacturing is the slurry mixing, which involves combining several powders including the active material. The active material is dosed into the mixer using powder dosing equipment. An extensive study has been carried out on the powder dosing equipment to reduce production time and improve the quality of the slurry. After understanding the equipment’s functionalities and conducting initial tests on both the anode and cathode, new adjustments were suggested. With the newly implemented adjustments, a significant reduction in production time by 50% was observed in the anode and therefore the energy consumption during dosing also decreased. It is important to note that big differences between anode and cathode were observed due to different chemical usage. Finally, this studied has successfully achieved a reduction in production time and energy consumption optimising the powder dosing equipment used in anode.

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No description available.

This thesis presents a series of studies pertaining to tribological, thermal, kinetic and slurry utilization aspects of chemical mechanical planaraization processes. The purpose of this work is to both develop a better method of characterizing the tribological mechanisms during polishing, as well as propose methods by which slurry utilization efficiency can be increased in order to minimize environmental hazards and operational costs associated with polishing without compromising the desired polish outcomes. The first study was conducted using a modified version of the generic Stribeck curve using real-time shear and down force data collection at 1,000 Hz. This investigation served to provide a better understanding of the tribological and thermal mechanisms associated with polishing copper and tungsten blanket wafers on an industrially relevant soft pad. A multitude of gradual yet continuous changes in sliding velocity and polishing pressure were applied during polishing. Results indicated that polishing on the soft pad produced stable coefficient of friction (COF) values entirely within the "boundary lubrication" regime, while copper polishing on a hard pads produced a tremendous spread of data and resulted in both “boundary lubrication” and "mixed lubrication" regimes. In addition, the average pad surface temperature showed a linear relationship with the product of the COF, sliding velocity, and downward pressure for all copper and tungsten polishes on both soft and hard pads. Another study in this thesis investigated slurry availability and the extent of slurry mixing for three different slurry injection schemes. An ultraviolet enhanced fluorescence technique was employed to qualitatively measure slurry film thicknesses atop the pad surface during polishing. This study investigated standard pad-center point slurry dispensing and a slurry injection system (SIS) that covered only the outer half of the wafer track. Results indicated that the radial position of slurry injection and fluid interactions with the SIS greatly influenced slurry mixing and availability atop the pad. Silicon dioxide removal rates were also found to increase as slurry availability increased. Using a combination of standard pad-center slurry dispensing and a half-wafer track SIS resulted in similar silicon dioxide removal rates as standard pad-center slurry dispensing but at a 40% lower slurry flowrate. The final study in this thesis investigated the effects of ultrapure (UPW) water dilution of a ceria-based slurry on silicon dioxide removal rates. Results showed that pre-mixing the slurry and UPW increased the removal rate with dilution up to a slurry to UPW ratio of 1:7.5 due to the increasing presence of Ce3+ via the reduction of Ce4+ by UPW. Further dilution yielded a plateau in the removal rate trend as additional UPW reduced the coefficient of friction (COF) and the temperature during polishing, causing the benefits of increased ceria-silica binding to be offset by mechanical limitations. Mixing the slurry directly at point-of-use at the dispense nozzle resulted in a removal rate trend that was highly similar to pre-mixing, however, removal rates were higher at every dilution ratio. A novel slurry injection system (SIS) was employed at various rotation angles as measured from the leading edge. The SIS angles produced different retaining ring bow wave thicknesses, which led to varying extents of dilution and, by extension, removal rates. The SIS at -8° produced the highest removal rates of all angles. A third dilution ratio test was performed using point-of-use mixing through the SIS at the optimum angle of -8°, which resulted in a similar removal rate trend as pre-mixing and pad-center dispense point-of use mixing, but with dramatically higher removal rates at each dilution ratio. The ability to attain higher removal rates could potentially allow integrated circuit (IC) manufacturers to either reduce polishing times or reduce slurry consumption, subsequently reducing slurry waste and creating a more environmentally benign semiconductor manufacturing process.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1980. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: leaves 36-38. / by Jan Adam Norris II. / M.S.

Thesis. 1975. Ph.D.--Massachusetts Institute of Technology. Dept. of Mechanical Engineering. / Vita. / Includes bibliographical references. / by Eugene C. Eckstein. / Ph.D.

Os resíduos de fármacos presentes em matrizes ambientais têm sido foco em pesquisas no mundo todo. Este tema tem sido bastante discutido devido ao fato de que fármacos são freqüentemente encontrados em efluentes de estações de tratamento de esgotos (ETE´s), águas de abastecimento público e em outras matrizes ambientais, tais como solos, sedimentos e águas naturais em concentrações na faixa de µg L-1 e ng L-1. A grande preocupação da presença de resíduos de fármacos na água são os potenciais efeitos adversos para a saúde humana, animal e de organismos aquáticos. Neste trabalho estudou-se o diclofenaco sódico, por ser um dos antiinflamatórios mais prescritos pelos médicos. O método utilizado para a extração do diclofenaco sódico de amostras de efluentes domésticos da ETE de Araraquara-SP foi à extração em fase sólida, e subseqüentemente a determinação por cromatografia líquida de alta eficiência com detector UV. O método foi validado e a recuperação foi de 94-105%. Constatou-se a presença do diclofenaco sódico nas amostras do efluente doméstico da cidade de Araraquara-SP antes e após o tratamento e as concentrações foram 2,12 e 3,52 µg L-1 na coleta feita em março e 18,0 e 22,0µg L-1 na coleta feita em setembro. / The pharmacos residues that are present in the environmental matrices has been a focus of research all over the world. This subject has been discussed because the fact that pharmacos are frequently found in effluents of sewage treatment plants (STPs), public water supply and in others environmental matrices, such as the soil, sediments and water springs in concentrations between µg L-1 and ng L-1. The biggest concern of pharmacos residues in the water are the adverse effects for the human health and the other species too. So, in this research the sodium diclofenac was studied for being the most prescribed anti-inflammatory by the doctors. The method used for the extraction of the sodium diclofenac of samples from the domestic effluent at STP-Araraquara (SP) was the extraction in solid phase, and subsequently the determination by liquid chromatography of high efficiency with UV detector. The method was validated and the recovery was of 94 to 105%. The results of the research have shown the presence of sodium diclofenac in the samples of Araraquara\'s domestic effluent before and after the treatment and the concentrations were 2,12 and 3,52 µg L-1 in the collection made in March and 18,0 and 22,0µg L-1 in the collection made in September.

Student Number : 0006342N - PhD thesis - School of Chemistry - Faculty of Science / An improved slurry method for determination of PGMs, gold and base metals (Ni, Cu, Fe and Co) using ICP-OES analytical instrument has been developed. This method has been successfully applied to quantitate metals in mineral concentrates and biological samples (grass, lichens, leaves and tree trunks) and validated using analytical figure of merit that include limits of detection, limits of quantition, accuracy and precision. Sample grinding using Fritsch GmbH Pulverissette Planetary Mono Mill was optimized to get > 60% and >80% of the particles to < 5.0 μm and < 10 μm respectively. The optimum grinding conditions for a sample mass of 0.4 g was determined as 130 rpm grinding speed and 30 minutes grinding time. An additional 15 minutes mixing with reagent was employed to ensure better slurry homogeneity for improved precisions. Five slurry dispersants; tetrasodium pyrophosphate, Triton X-100, dodecylbenzene sulfonic acid sodium salt, potassium cyanide and potassium thiocyanate, were evaluated at varied concentrations and 0.1% v/v Triton X-100 established as the best dispersant for slurry preparation. The ICP-OES sample delivery system was modified by introducing an extension elbow between the torch and the spray chamber that not only effectively reduced the sample residence time in the plasma for efficient atomization of the particles but also acted as a gravitational sieve eliminating larger particles and droplets. Prepared slurries were continuously agitated using an ultrasonic bath prior to and during aspiration into ICP-OES to prevent sedimentation and ensure constant stability of the slurry. Optimum operating conditions for ICP-OES established as 1600 W and 1450 W plasma power for PGMs and base metals respectively, using a nebulizer flow rate of 0.8 mL min-1, coolant gas flow rate of 13.0 mL min-1, auxiliary gas flow rate of 1.0 L min-1 with a sample uptake rate of 0.2 mL min-1. Limits of detection for the developed technique were determined in μg g-1 as 0.075, 0.039, 0.115, 0.071, 0.035 and 0.118 for Au, Ir, Pd, Pt, Rh and Ru respectively and 0.15, 0.391, 0.345 and 0.217 for Ni, Cu, Fe and Co respectively. Limits of quantitation in μg g-1 were obtained as 0.250, 0.130, 0.383, 0.237, 0.117 and 0.393 for Ir, Pd, Pt, Rh and Ru respectively and 0.5, 1.31, 1.15 and 0.723 for Ni, Cu, Fe and Co respectively. Good accuracy was recorded for all the base metals as well as for the platinum group metals and gold except iridium that was susceptible to copper interference. Two measurements of precision, reproducibility and repeatability were assessed. Reproducibility was obtained in percentages as 12, 7.93, 5.54, 10 and 12 for Au, Pd, Pt, Rh and Ru respectively and 9.9, 10, 9.8 and 10 for Ni, Cu, Fe and Co respectively. Repeatability was obtained in percentages as 11, 7.03, 4.94, 8.08 and 9.85 for Au, Pd, Pt, Rh and Ru respectively and 9.4, 9.6, 9.7 and 10 for Ni, Cu, Fe and Co respectively. Good percentage recoveries were obtained of 104.3%, 98.3%, 98%, 90.5% and 92.8% for Au, Pd, Pt, Rh and Ru respectively. Percentage recoveries of 109%, 111%, 89.9% and 100% for Ni, Cu, Fe and Co respectively were obtained. The simplicity and low cost of sample preparation used in this method enables it to be easily adopted in any ICP-OES laboratory. A single analyst may achieve more sample through-puts than before per day (including re-grinding and analysis), resulting in a highly economical and rapid technique for determination of metals.

Drilled shafts are large cylindrical cast-in-place concrete structural elements that can be favored due to cost-effectiveness. These elements however, require strict quality control during construction to ensure a stable excavation. Drilling fluid is often used in construction to attain this stability. Drilling fluid, or slurry, can be ground water or salt water, but is typically made from a mixture of water and mineral or polymer powder to form a viscous fluid slightly more dense than ground water. During concreting, the drilling fluid is displaced by the heavier concrete, which is tremie placed at the base of the excavation from the center of the reinforcement cage. While concrete used for drilled shafts should be highly fluid, it does not follow an ideal, uniform flow. The concrete rather builds up inside the reinforcement cage to a sufficient height before then pressing out radially into the annular cover region. This concrete flow pattern associated with drilled shafts has been shown to trap slurry around/near the steel reinforcement and affect reinforcement bond strength. Presently there are no specifications relating to slurry effects on reinforcing bar bond strength from the American Concrete Institute (ACI) or the American Association of State and Highway Transportation Officials (AASHTO). This dissertation analyzes longitudinal reinforcing bar concrete bond strength data recorded from 268 specimens constructed with tremie-placed concreting conditions in varying drilling fluids. Reinforcement used for testing were No. 8 deformed rebar. Based on the results found from this analysis, this dissertation recommends the use of a slurry modification factor to current bond strength and development length specifications.

<p>Today the use of anaerobic digestion technique emerges as an alternative to the conventional treatment method of pig slurry to the pig producers in Brazil because of the energy demanding intensive pig production and the negative environmental impact that arises during storage and use. The end products of AD technique are biogas as an energy source and digestate that can be used as a fertilizer.</p><p>The study took place at two pig producers in southern Brazil in order to evaluate the biogas production in the area, its applications and environmental impact. The visited pig producers run a confined animal production system where the slurry that is used in the anaerobic digesters is diluted.</p><p>The studied digesters are covered with an air tight flexible plastic membrane that takes the shape of a balloon where each digester has the volume of 620 m3. Sedimentation occurs inside each reactor where the temperature also fluctuates. The produced biogas is conveyed to a torch where</p><p>the biogas is combusted.</p><p>The results of this study show that the digesters are working properly but there is a need for mixing and constant temperature in order to optimize the process. Biogas is primarily suited for heat production and the digestate can be used as a fertilizer. Biogas production is considered to have a positive environmental impact if the biogas is used or combusted in a torch. There is also a need to apply a cover over the digestate during the storage time to avoid ammonia emissions.</p><p>The approximated biogas potential for Rio Grande do Sul is nearly 100 GWh/year. For an</p><p>approximated biogas potential of more consideration it is found that further studies of the housing systems in Rio Grande do Sul are needed. This is due to a greatly varying amount of degradable materials in the pig slurry from one ranch to another.</p>