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An in situ kinetic investigation of the selective dissolution mechanism of Cu alloys / Une étude cinétique in situ du mécanisme de dissolution sélective des alliages de CuZhou, Peng 13 October 2017 (has links)
Les mécanismes de dissolution sélective des alliages de Cu dans l'eau du robinet et la solution de transpiration ont été étudiés. La spectroélectrochimie d'émission atomique a été utilisée. La première partie de la thèse portait sur le mécanisme de dissolution de Cu. La plupart des espèces de Cu (II) sont solubles et sont libérées dans l'eau, laissant derrière eux un film de Cu2O. Une analyse cinétique suggère que le mécanisme de dissolution implique la dissolution simultanée du Cu et la formation du film. La deuxième partie a étudié la dissolution de Cu-42Zn et Cu-21Zn-3Si-P. Un processus de dissolution en deux étapes a été proposé: une première étape d'une croissance rapide de la couche dézincitée et une deuxième étape où la croissance de la couche dézincitée était plus lente. La troisième partie s'est concentrée sur l'effet du contenu de Zn sur la dissolution des alliages de Cu-Zn. Le mécanisme de dissolution a été clarifié. Pour la phase ?: une étape initiale dans laquelle Cu et Zn sont oxydés de manière congruente, mais seulement Zn2+ a été libéré dans l'eau, Cu formant un film Cu2O et une deuxième étape où le Cu2+ a été libéré dans l'eau. Pour la phase ?', la deuxième étape est identique à la phase initiale. L'augmentation de la teneur en Zn entraîne une extension temporelle du stade initial et retardent la libération de Cu2+. La partie finale a porté sur l'effet de la libération de Sn on Cu provenant des alliages Cu-Sn. L'effet amélioré de la libération de Sn sur Cu a été identifié. Cependant, l'augmentation de la teneur en Sn n'a pas augmenté monotoniquement l'efficacité de libération de Cu des alliages de Cu-Sn, ce qui était dû à la passivité de Sn. / The selective dissolution mechanisms of Cu alloys in tap water and perspiration solution were investigated. Atomic emission spectroelectrochemistry (AESEC) was used to obtain the elemental dissolution kinetics. The first part of the thesis focused on the dissolution mechanism of Cu. Most Cu(II) species are soluble and are released into tap water, leaving behind a Cu2O film on the surface. A kinetic analysis suggests that the dissolution mechanism involves simultaneous Cu dissolution and film formation. The second part investigated the dissolution behavior of Cu-42Zn and Cu-21Zn-3Si-P. A two-stage dissolution process of dezincification was proposed: a first stage of a rapid growth of the dezincified layer and a second stage where the growth of dezincified layer was much slower. The third part concentrated on the effect of Zn content on the dissolution of Cu-Zn alloys, by investigating the dissolution behavior of alloys with various Zn content (0-45 wt%). The two-stage dissolution mechanism was further clarified. For α phase: an initial stage in which Cu and Zn are oxidized congruently, but only Zn2+ was released into water, Cu forming a Cu2O film, and a second stage where Cu was released into water in the form of Cu2+. For β' phase, the second stage is the same to the initial stage. The increase of Zn content in the alloy results in a time extension of the initial stage and retard Cu2+ release. The final part focused on the effect of Sn on Cu release from Cu-Sn alloys. The enhanced effect of Sn on Cu release was identified. However, the increase of Sn content didn’t monotonically increase the Cu release efficacy of Cu-Sn alloys, which was due to the passivity of Sn.
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Autism and the Performing Arts: Using BST to Teach Dance to Children with ASDFreed, Calyn 02 November 2017 (has links)
Behavioral skills training (BST) has been proven effective in helping children with autism spectrum disorder (ASD) acquire new skills. Little research had been done to evaluate the effect of BST on the acquisition of sport skills within this population, and no research exists in regards to using BST to teach dance skills to individuals with ASD. The purpose of this study was to evaluate the effectiveness of BST for teaching dance steps to children diagnosed with ASD. This study used a multiple baseline across behaviors design. The dance movements that were targeted consisted of a tap step, a leap, and a turn. Skill acquisition was scored using a task analysis for each dance step to calculate percentage correct. This study found that the use of BST increased the percentage correct of each dance step from baseline levels in all three participants.
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Study on Contamination of Perfluorinated Compounds (PFCs) in Water Environment and Industrial Wastewater in Thailand / タイにおける水環境および工業廃水のペルフルオロ化合物(PFCs)汚染に関する研究 / タイ ニ オケル ミズ カンキョウ オヨビ コウギョウ ハイスイ ノ ペルフルオロ カゴウブツ ( PFCs ) オセン ニ カンスル ケンキュウKunacheva, Chinagarn 24 September 2009 (has links)
PFCs are used in a wide variety of industrial and commercial applications for more than 50 years. Among variation of PFCs, Perfluorooctane sulfonate (PFOS) (CF3(CF2)7SO3-) and perfluorooctanoic acid (PFOA) (CF3(CF2)6COO-) are the most dominant PFCs. In May 2009, PFOS, its salts and perfluorooctane sulfonyl fluoride (PFOSF) are designated as new Persistent Organic Compounds (POPs) which are resistant, bio-accumulating, and having potential of causing adverse effects to humans and environment (IISD, 2009). However, products containing PFCs are still being manufactured and used, which could be the main reason why they are still observed in the environment and biota (Berger et al., 2004; Saito et al., 2003; Sinclair et al., 2004). The study is focused on the PFCs contamination in water and industrial wastewater around the Central and Eastern Thailand, where is one of the major industrialized areas in the country. The samplings were conducted in major rivers, Chao Phraya, Bangpakong and Tachin River. PFCs were contaminated in all rivers. The average total PFCs were 15.10 ng/L, 18.29 ng/L and 7.40 ng/L in Chao Phraya, Bangpakong and Tachin River, respectively. PFOS and PFOA were the predominant PFCs in all samples. The total of 118.6 g/d PFOS and 323.6 g/d PFOA were released from the three rivers to the Gulf of Thailand. The survey was also conducted in small rivers, reservoirs, and coastal water around Eastern Thailand, where many industrial zones (IZ) are located. The geometric mean (GM) concentration of each PFC was ranged from 2.3 to 107.7 ng/L in small rivers, 2.2 to 212.2 ng/L in reservoirs, and 0.8 to 41.1 ng/L in coastal water samples. The higher PFCs contaminations were detected in the surface water around the industrial zones, where might be the sources of these compounds. Field surveys were also conducted in ten industrial zones (IZ1 – IZ10) to identify the occurrences of PFCs from in industries. The recovery rates of PFCs in the samples indicated that the matrix interference or enhancement was an important problem in PFCs analysis. The elevated concentrations were detected in electronics, textile, chemicals and glass making industries. Total PFCs concentrations in the influent of WWTP were ranged from 39.6 to 3, 344.1 ng/L. Ten industrial zones released 188.41 g/d of PFCs. All of the treatment processes inside industrial zones were biological processes, which were reported that they were not effective to remove PFCs. The influence of industrial discharges was affected not only the rivers and reservoirs but also in the coastal water. The PFCs in rivers and reservoirs were discharged to the Gulf of Thailand, which is the important food source for Thai people and exports. Due to the problems in industrial wastewater analysis, several optimizing options were applied in PFCs analytical method especially in Solid Phase Extraction (SPE) procedure. The combination of PresepC-Agri and Oasis®HLB was the better option for analyzing PFCs in water samples. The optimum flow rate for loading the samples was 5 mL/min. Methanol (2 mL) plus Acetronitrile (2 mL) was the effective way to elute PFCs from the cartridges. The specific solvent percentages to elute each PFCs were identified for both water and industrial wastewater samples. The matrix removal methods by using Envi-Carb and Ultrafilter were effective for different types of industrial wastewater samples. PFCs were detected in surface waters, which are the sources of tap and drinking water for the people in Central and Eastern Thailand. The surveys were conducted in Bangkok city. Samples were collected from water treatment plants (WTPs), tap water, and drinking water. PFCs were detected in all tap water and drinking water samples. PFOS and PFOA concentrations in raw water of WTP were found 4.29 ng/L and 16.54 ng/L, respectively. The average PFOS and PFOA concentrations in tap water were detected 0.17 and 3.58 ng/L, respectively. The tap water results also showed that PFOS and PFOA concentrations were not similarly detected in all area in the city. PFOA were detected higher in the western area, while PFOS concentration was quite similar in all areas. Overall, it can be concluded that the current treatment processes were not completely remove PFCs. Nevertheless, PFCs in particulate phase were effectively removed by the primary sedimentation and rapid sand filtration. Elevated PFCs were found in the industrial zones (IZ2 and IZ5). To understand the distribution and fate of PFCs during industrial wastewater process, PFCs mass flows were studied. Higher PFCs in adsorbed phase were detected only in activated sludge and some influent samples. In IZ2, PFOA loading in the dissolved phase increased after activated sludge process by 5%. There was no degradation of PFOA inside the polishing pond. The highest loading to the treatment plant was PFOS with the loading of 2, 382 mg/d and 1, 529 mg/d in dissolved and adsorbed phase, respectively. Unlike PFCAs that showed no removal in the treatment process, PFOS were decreased during the treatment processes with 36% in the activated sludge process and 36% in the polishing pond. The predominant in this IZ5 was PFOS. The increasing of PFOS was also found in this treatment plant dissimilar to IZ2. PFOS was increasing by 45% in dissolved phase and 47% in adsorbed phase. All of PFCs in this industrial zone were detected higher in the effluent, indicated that PFCs’ precursors should be the major effects of this contamination. / Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第14930号 / 工博第3157号 / 新制||工||1473(附属図書館) / 27368 / UT51-2009-M844 / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 田中 宏明, 教授 清水 芳久, 教授 藤井 滋穂 / 学位規則第4条第1項該当
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Localisation de l'ARN polymérase II humaine à travers le génome en couplant double immunoprécipitation de la chromatine et clonageCôté, Pierre January 2005 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
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La machinerie transcriptionnelle basale : étude de son organisation moléculaire au promoteur génique et de ses interactions avec les régulateurs XAB1 et DDX5Thérien, Cynthia January 2005 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
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Banning Bottled Water in Concord, MA: How an Apolitical Commodity Became PoliticalBegg, Rachel January 2014 (has links)
This thesis paper explores how various actors gathered around bottled water when a ban was put into place in Concord, Massachusetts. The objective has been to answer the following questions: How does an apolitical commodity become a political one? Specifically, how does bottled water move from being an apolitical commodity to become a highly political one? What does this mean for environmental politics? I situate my theoretical approach within Martha Kaplan’s research with fountains and coolers. I use Bruno Latour to show in which ways this ban became a matter of concern, as well as how the ban and the plastic bottle are actors. I conducted fieldwork in Concord and I interviewed participants. My findings reveal that the ban brought meanings to the surface and challenged them or supported them in various ways. The discussions turned from the impact of bottled water on our environment to the political impact of bottled water companies and large corporations on local Concord issues.
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Distribution network supports for transmission system reactive power managementChen, Linwei January 2015 (has links)
To mitigate high voltages in transmission systems with low demands, traditional solutions often consider the installation of reactive power compensators. The deployment and tuning of numbers of VAr compensators at various locations may not be cost-effective. This thesis presents an alternative method that utilises existing parallel transformers in distribution networks to provide reactive power supports for transmission systems under low demands. The operation of parallel transformers in small different tap positions, i.e. with staggered taps, can provide a means of absorbing reactive power. The aggregated reactive power absorption from many pairs of parallel transformers could be sufficient to provide voltage support to the upstream transmission network. Network capability studies have been carried out to investigate the reactive power absorption capability through the use of tap stagger. The studies are based on a real UK High Voltage distribution network, and the tap staggering technique has been applied to primary substation transformers. The results confirm that the tap staggering method has the potential to increase the reactive power demand drawn from the transmission grid. This thesis also presents an optimal control method for tap stagger to minimise the introduced network loss as well as the number of tap switching operations involved. A genetic algorithm (GA) based procedure has been developed to solve the optimisation problem. The GA method has been compared with two alternative solution approaches, i.e. the rule-based control scheme and the branch-and-bound algorithm. The results indicate that the GA method is superior to the other two approaches. The economic and technical impacts of the tap staggering technique on the transmission system has been studied. In the economic analysis, the associated costs of applying the tap staggering method have been investigated from the perspective of transmission system operator. The IEEE Reliability Test System has been used to carry out the studies, and the results have been compared with the installation of shunt reactors. In the technical studies, the dynamic impacts of tap staggering or reactor switching on transmission system voltages have been analysed. From the results, the tap staggering technique has more economic advantages than reactors and can reduce voltage damping as well as overshoots during the transient states.
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Avaliação do desempenho de machos tratados com um condicionador metálico no processo de rosqueamento internoOliveira, Fernando Santos de 07 April 2015 (has links)
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Previous issue date: 2015-04-07 / It is important that the machining processes are continually improved in order to provide competitive advantages and economic conditions for manufacturing companies. A very used manufacturing process, mainly because it is one of the few that allow obtaining small diameter internal thread, is the thread tapping with thread cutting taps. As such, thread tapping is one of the last process to be carried out and any failure can influence in production costs. One way to reduce costs is by increasing the useful life of the thread tap through the use of surface treatments, coatings or cutting fluids. Therefore, the main objective of this work is to evaluate the performance of the application of a dry impregnated lubrication on the surface of thread taps, with a focus on conventional tapping process improvement concerning tool useful life and, consequently, costs reduction. For this purpose, tests in the tapping process were performed using high speed steel taps in two conditions, i.e., treated or not with a dry impregnated lubrication. The results obtained allow to conclude that the procedure employed was appropriate, because it increased the tool useful life, reduced the tool wear, and maintained the thread quality, promoting a reduction in manufacturing costs. / É importante que os processos de usinagem sejam continuamente melhorados, de forma a oferecer vantagens competitivas e condições econômicas para as indústrias manufatureiras. Um processo de fabricação muito empregado, principalmente por ser um dos poucos a permitir a obtenção de roscas internas de pequeno diâmetro, é o processo de rosqueamento interno com machos. Tal processo, normalmente é um dos últimos a ser realizado e qualquer falha pode influenciar os custos de produção. Uma forma de minimizar os custos no processo de rosqueamento interno é a utilização de abordagens que visam otimizar a vida útil do macho de roscar por meio do uso de tratamentos superficiais, revestimentos ou fluidos de corte. Dessa forma, este trabalho tem como objetivo principal avaliar o desempenho da aplicação de um condicionador de metais na superfície de machos, com foco na melhoria do referido processo em relação à vida útil da ferramenta e, consequentemente, na redução de custos. Para tanto, ensaios foram realizados utilizando-se de machos de aço rápido em duas condições: tratados ou não com condicionador metálico. Os dados coletados foram analisados com apoio de recursos estatísticos para se verificar o nível de confiança das amostras. Os resultados obtidos permitem concluir que o procedimento utilizado foi adequado, pois aumentou a vida útil do macho, reduziu o nível de desgaste das ferramentas, mantendo-se a qualidade das roscas e, consequentemente, promoveu uma redução nos custos de fabricação.
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Mechanisms of Slowed Foot Tap Speed in Older AdultsHartman, Erica L 13 July 2016 (has links)
Rapid repetitive tapping, like the Foot Tap Test (FTT), slows with age, but the underlying mechanisms are unknown. Purpose: 1. Test the hypotheses that greater performance variability, increased muscle coactivation, and slowed muscle contractile speeds are related to lower foot tap count (FTC) in older adults; 2. Examine the relationship between FTC and physical function in older adults, using the advanced SPPB-A. Methods: 18 (25.0±3.1years, 9F, mean±SD), and 28 (73.4±4.9, 14F) adults were recruited; the later were divided into Higher (HFO) and Lower (LFO) Functioning based on SPPB-A score. Participants performed 10s of rapid tapping (FTT) while seated. A MATLAB program was used to calculate FTC and variability of the intertap-interval (COV-ITI). Contractile speed (rates of force development and relaxation, RFD and RFR) of the dorsiflexor muscles were determined using ballistic contractions. Electromyography was recorded on the tibialis anterior, soleus, and coactivation was calculated based on their agreement. Results: LFO had a lower FTC than Young and HFO (45.9±7.0taps, 54.4±7.5, 53.1±5.7, respectively; p=0.003), and lower COV-ITI than Young (12.3±5.9%, 20.5±8.1, respectively, p=0.009). No associations were found between COV-ITI and FTC. Coactivation was higher in Young than HFO (0.568±0.209, 0.321±0.129) and was negatively related to FTC in older (r2=0.274, p=0.005). The LFO had a slower RFD than Young and FTC was positively related to maximal RFD (r2=0.345, p=0.001) and RFR (r2=0.162, p=0.038) in older adults. In older, FTC was related to SPPB-A (r2=0.329, p=0.001). Conclusions: Greater coactivation during the FTT and slower force development may negatively affect FTC in older adults.
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Optimering av spårplan i depå Hagalund / Optimising the Track Allocation Problem at the Hagalund Train DepotHammarstedt, Lovisa, Stefan, Åberg January 2018 (has links)
SJ AB is the leading railway operating company in Sweden and is owned by the Swedish government. In Hagalund train depot (HGL) SJ AB, as well as some of SJ AB:s competitors, run their operational maintenance. The HGL property is owned by Jernhusen but some of the infrastructure is owned by Trafikverket; the Swedish transport administration. The number of depot tracks available for SJ AB have been reduced over time, as competition is increasing. SJ AB constructs their own track plans, i.e. decide the arrival and departure track for each train turnaround in the depot. These track plans are currently made by a so called production planner in the planning system RPS. In RPS the planners base their decisions on common sence, as there is no optimising function in the system. The mathematical problem associated with this task is called the Track Assignment Problem (TAP), which is a well-known problem within railway related research. This report presents an optimisation program - TAP Solver (TAPS) - that takes information from RPS and then generates an optimised solution visualised as a track plan. The user is given the opportunity to direct the solution through parameters in a weight matrix in Excel. TAPS is created to make the process of constructing a track plan both faster and easier. Our results show that TAPS is able to find the optimal 24 hour track plan within a few minutes.
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