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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
251

From Collectives to Connectives: Italian Media Activism and the Repurposing of the Social

Renzi, Alessandra 31 August 2011 (has links)
The dissertation develops the concept of repurposing as a means for thinking with activists and the issues they confront. It moves alongside pirate television collective insu^tv as they draw on a variety of histories, traditions and technological resources for their practices. Repurposing functions on multiple levels and at multiple scales, from the recycling of materials and spaces to the harnessing and relaying of encounters and events within an ever-expanding field of social relations. When seen as a way of connecting activist groups and communities, the repurposing of media contributes to strengthening an often fragmented and conflicted activist field. Indeed, insu^tv’s use of information and technology brings to the fore the value of media activism for the creation of social assemblages in which the “media” literally mediates between individuals and among individuals and their environment, instituting and developing an ontogenetic relation (Simondon, 1989). Yet, rather than simply making sense of insu^tv’s practices, the concept of repurposing also provokes a discussion regarding the ethics of connection. For insu^tv, this connective ethics can be understood as a set of rules and principles that facilitate the evaluation of actions, communication, and thought according to an immanent mode of collective existence (Deleuze, 1988; Simondon, 1989). For the author, herself a member of insu^tv and an academic researcher, this immanent position helps challenge traditional models of knowing and envisioning social change and instead proposes alternatives that attend to the singularity and relation among new political movements, and to the political potential of research methods that focus on process and fold activism into academia. The methodology is inspired by the militant research methods of the Italian Autonomia movement (conricerca or inchiesta), as developed and performed by activists themselves. While attending to the complexity of social struggles, the concept of repurposing enables an approach to research and experimentation as modes of sociability, where these modes are themselves repurposed through an ethics of connection. This line informs the relation between ethics and subjectivation, as well as between ethics and micropolitics, facilitating the emergence of new modes of political action through the repurposing of the social field itself.
252

Charge accumulation effects on time transition of partial discharge activity at GIS spacer defects

Okubo, Hitoshi, Endo, Fumihiro, Hayakawa, Naoki, Kojima, Hiroki, Nishizawa, Kanako, Mansour, Diaa-Eldin A 02 1900 (has links)
No description available.
253

Surface charge accumulation and partial discharge activity for small gaps of electrode/epoxy interface in sf6 gas

Okubo, Hitoshi, Mansour, Diaa-Eldin A., Kojima, Hiroki, Hayakawa, Naoki, Endo, Fumihiro 08 1900 (has links)
No description available.
254

Oxidized soybean oil alters the expression of PPAR gamma and target genes in 3T3-L1 cells

Dingels, Nicole Katherine 15 November 2012 (has links)
Background: The typical western diet contains foods with modest amounts of lipid oxidation products. Previous work by us and others have demonstrated that mildly oxidized lipids promote a gain in fat mass while highly oxidized lipids decrease fat mass in rodents and triglyceride (TAG) accumulation in 3T3-L1 cells. Adipocyte differentiation is regulated by a key nuclear transcription factor known as PPARγ. Objective: To investigate if the alterations in triglyceride accumulation in 3T3-L1 cells pretreated with oxidized soy oil are due to 1) a change in PPARg DNA interactions 2) changes in the expression of SREBP-1c, PPARg, and/or its target genes. Main Methods: Confluent 3T3-L1 cells were pretreated for 24hours with 0.01% soy oil (SO) which was either unheated (unheated SO) or heated for 3, (3h-SO), 6 (6h-SO), or 9hours (9h-SO). The effect of 24hour soy oil exposure was assessed at several time points throughout the differentiation process. Alterations in PPARg DNA interaction was assessed using a PPARγ transcription factor assay kit while alterations in the expression of genes upstream and downstream of PPARγ was determined by RT-PCR. Primary and secondary products of oxidation within the SO were determined by spectrophotometry. Results: The 6hr-SO contained the greatest concentration of peroxides whereas both the 6hr-SO and 9hr-SO contained a significantly higher concentration of conjugated dienes and aldehydes.Nuclear extracts from 3T3-L1 cells pretreated with 6h-SO demonstrated the greatest reduction in PPARγ DNA binding. Compared to the unheated SO and mildly oxidized 3h-SO, cells treated with the 6h-SO had a significant reduction in SREBP-1c, PPARg, LPL, and GLUT4 expression occurring early in the differentiation process. Variations in the gene expression of 6hr-SO pretreated cells persisted within partially differentiated and mature adipocytes. Conclusions: Pre-treatment of preadipocytes with soy oil heated for ³ 6h greatly decreases the activity of PPARγ in the nucleus and adipogenic gene expression . These changes seen in early differentiation seem to correlate the best with the phenotype of reduced triglyceride accumulation seen in mature adipocytes.
255

Förstudie till flödesackumulering på Astra Tech / Pre-study of flow accumulation at Astra Tech

Johansson, Pontus, Kullberg, Lovisa January 2011 (has links)
Syftet med arbetet var att undersöka möjligheten för optimering av produktflödet. Företagets produkter transporteras på ett transportband till en gemensam process. Det nuvarande flödet till processen är inte optimerat vilket resulterar i att processen körs ineffektivt. Ackumulering av produkter innan processen ska därför undersökas som en lösning till problemet. Fyra olika ackumuleringsförslag har analyserats och jämförts: hängande bansystem, palleteringssystem, depalleteringssystem och kombination av bansystem och palleteringssystem. Förslagen har blivit bedömda och jämförda utifrån följande parametrar: yta, investeringskostnad, flexibilitet, arbetsbelastning, arbetsmiljö och tid. Hängande bansystem fick det högsta snittvärdet och valdes därför för fortsatt analys med stöd av simulering. Simuleringen gjordes i ExtendSim 7. Två simuleringsmodeller jämfördes, en med ackumulering av produkter i bansystem och en utan. Resultatet var att ackumulering av produkter kan ge en besparing på 16 procent i driftkostnader per år. Simulering av övriga förslag kan göras för att få en tydligare jämförelse mellan förslagen. Rekommendationen till företaget är att ackumulera produkter i ett bansystem. Det baseras på analys av jämförelsen. Analysen och diskussionen visar också att robothantering inte är en passande lösning på problemet, eftersom rörelserna skulle skaka om produkterna för mycket. En vidare undersökning av utformningen av bansystemet bör göras för att få fram den optimala utformningen. / The purpose of the work was to investigate possibilities for optimization of the material flow. The different products of the company are being transported by a conveyor belt to a common process. The current flow to the process is not optimized with the result that the process runs inefficiently. Accumulation of products before the process should therefore be investigated as a solution. Four different accumulating systems have been analyzed and compared: hanging conveyor belts, palletizing, depalletizing and a combination of conveyor belts and palletizing. The systems have been assessed and compared according to six parameters: area, investment cost, flexibility, work load, work environment and time. The hanging conveyor belt yielded the highest average score and was therefore chosen for further analysis with the support of simulation. The simulation was made in ExtendSim 7. Two simulation models were compared, one with accumulation of product in conveyor belts and one without. The result of the simulation part was that accumulation of product results in savings of running costs with 16 percent per year. To get a better comparison between the accumulation systems simulations of all systems can be done. The recommendation to the company is to accumulate products in a conveyor system. This is based on the analysis of the comparison. The analysis and discussion also shows that robot handling is not an appropriate solution to the problem, because the movements would shake the products too much. A further investigation of the layout should be done in order to find the optimal layout.
256

Accumulation, distribution and employment. A structural VAR approach to a Post-Keynesian Macro Model.

Stockhammer, Engelbert, Onaran, Özlem January 2002 (has links) (PDF)
The paper investigates the relation between effective demand, income distribution and unemployment empirically. Its aim is to evaluate Keynesian, Kaldorian and neoclassical hypotheses about the determination of labor market variables. To do so, a vector autoregression model consisting of capital accumulation, capacity utilization, the profit share, unemployment and the growth of labor productivity is estimated. A general post-Keynesian model following the lines of Kalecki and Kaldor is presented and provides the specification for a structural VAR. The model is estimated for the USA, UK and France. (authors' abstract) / Series: Working Papers Series "Growth and Employment in Europe: Sustainability and Competitiveness"
257

Snow hyydrology of Canadian prairie droughts : model development and application

Fang, Xing 06 September 2007 (has links)
Hydrological models have been developed to estimate snow accumulation, snowmelt and snowmelt runoff on the Canadian Prairies; however, their proper scale of application is unknown in the Prairie environment. The first objective of this thesis is to examine the proper scale for pre-melt snow accumulation as snow water equivalent (SWE) and snowmelt in a Prairie first order basin. Spatially distributed and spatially aggregated approaches were used to calculate SWE and snowmelt at St. Denis National Wildlife Area (SDNWA). Both approaches used models with similar physics, but differed in the model scale at which calculations were carried out. The simulated pre-melt SWE, cumulative seasonal SWE, and daily snowmelt from the two modelling approaches were compared to field observations of pre-melt SWE, cumulative seasonal SWE, and daily snowmelt; comparisons of areal cumulative seasonal SWE, areal snowmelt, snowmelt duration, and snow-covered area were also conducted between two modelling approaches. Results from these comparisons showed that both approaches had reasonable and similar accuracy in estimation of SWE and snowmelt. The spatially aggregated approach was more computationally efficient and was selected as a modelling scale for small-sized prairie basins. <p>Another objective of this thesis is to derive a snow hydrology model for the Canadian Prairies. Physically-based hydrological models were assembled in the Cold Regions Hydrological Model Platform (CRHM) using the aggregated approach. Tests of pre-melt SWE and surface snowmelt runoff were conducted at two basins in Saskatchewan Creighton Tributary of Bad Lake and Wetland 109, St. Denis. Results showed that the snow hydrology model had a reasonable capability to simulate SWE and snowmelt runoff to the stream and wetland. <p>Droughts are natural hazards that develop frequently on the Canadian Prairies. Analyzing the impact of drought on hydrological processes and water supply is another objective of this thesis. Synthetic drought scenarios were proposed for the Creighton Tributary of Bad Lake and the corresponding impacts on the snowmelt runoff-related processes were examined. Results indicated that wind redistribution of snow was very sensitive to drought conditions, sublimation of blowing snow and snow-covered period were sensitive to drought, but winter evaporation and infiltration did not show strong trend. The results also showed that drought conditions had magnified effects on the snowmelt runoff and could cause cessation of streamflow. Also, the impacts of the recent 1999-2005 drought on the snowmelt hydrology were investigated at St. Denis. Results illustrated that three-years (1999-2002) of severe winter drought were followed by a normal year (2002-03) and then a two-year (2003-05) recovery period, and then returning to normal (2005-06). Results showed that both snowfall and rainfall during hydrological winter were consistently low for severe drought and surface snowmelt runoff was very much lower during severe drought, about 45-65 mm less compared to that in the normal periods.
258

Development of river water quality and sediment management strategies

Lin, Chih-En 24 August 2010 (has links)
The river water quality management strategy involves a series of complex inter-disciplinary decisions based on speculated responses of water and sediment quality to changing controls. In the aquatic system a rapid removal of the heavy metals from the water to sediments may occur by settling particles while some of these pollutants can be mobilized by getting accumulated into the biota from the sediments sink. Thus, sediment plays a major role in the determining pollution pattern of aquatic systems. It acts as both carriers and sinks for contaminants, reflecting the history of pollution, and providing a record of catchment inputs into aquatic ecosystems. The Yan Shuei Gang River watershed is one the river watersheds in Kaohsiung City, Taiwan. It is 5-km long, drains a catchment of more than 1,200 ha. Part of the river water is from the domestic drainage areas located in the upper catchment. In Linhai Industrial Parks, there are more than 493 registered industrial factories that discharge their wastewater into the Yan Shuei Gang River. Thus, recent water and sediments quality analysis indicates that the Yan Shuei Gang River is heavily polluted. The major objectives of this study were to (1) perform water quality and sediments sampling and analyses, (2) perform water quality simulation and demonstrates the model application to the Yan Shuei Gang River, (3) assess the water and sediments quality, (4) provide foci for immediate remediation efforts, (5) provide benchmark levels to test outcomes of future remediation efforts, (6) design a novel extraction technique that utilizes a mildly elevated pressure in consecutive cycles with a chelating agent for the sediment slurry. Water quality investigation results show that the biochemical oxygen demand (BOD), ammonia-nitrogen (NH3-N), and suspended solid (SS) average concentrations in water samples of the Salt-water River varied from 10.2 to 194, 8.51 to 18.3, and 7.9 to 19.5 mg/L, respectively. The results of the chemical analysis of the Salt-water River surface sediments showed that the sediments present highly elevated Cd, Cr, Ni, Cu, Pb, Zn and Fe concentrations. Investigation results reveal that sediment samples contained significant amount of iron (up to 3.6%), Cr (up to 66.5 mg/kg), Pb (up to 36.5 mg/kg), Ni (up to 43 mg/kg), and Al (up to 1.8%). All heavy metal concentrations were higher than the world average, sediments average and sediment quality guidelines (SQGs). Although all metals showed varied concentrations, the approaches of factor analysis, normalized enrichment factor (EF), and the geo-accumulation index (Igeo) proposed in this paper were effectively used to differentiate the natural and anthropogenic sources of the metals. Both the EF and Igeo indicated similar anthropogenic contamination degree of the metals. The potential acute toxicity in sediment of Yan Shuei Gang River was observed to be mainly due to Cu contamination. Cu was the major toxicity contributor accounting for 32-46% of the total toxicity in Salt-water River, followed by Zn. The Water Quality Analysis Simulation Program (WASP) model developed by US Environmental Protection Agency (EPA) was selected as a water quality planning tool to perform the water quality evaluation. Modeling results show that the current daily pollutant inputs were much higher than the calculated carrying capacity for nutrients and BOD of the Yan Shuei Gang River. Based on the results from this study, the following remedial strategies have been proposed to minimize the impacts of industry and domestic source pollution on the water quality of Salt-water River: (1) increase the flow by transporting 1 m3/s unpolluted surface water from other sources to dilute the polluted river water, (2) construction of the intercepting systems to effective intercept and transport the untreated wastewater to the wastewater treatment systems. The sediments batch extracted by 150 psi pressure cycles has the most Cu removed rater (70%), much higher than without treatment (55%) or with 90 psi pressure cycles treatment (65%). Pressure-assisted extraction achieves in 60 min the amounts of Cu equal to or exceeding those achieved in 240 min without pressure cycles under the same concentration conditions. This research indicates that the advantages of pressure cycle system are increased process speed, more thorough extraction, and reduced use of the chelating agent. The heightened treatment is explained by sediments aggregate fracturing upon pressure cycles that exposes the contaminants as well as by the chelating agents. The technique is expected to accelerate extraction treatment of a wide range of heavy metal contaminants, and it may provide treatment to dredged and stored contaminated sediments. Experience obtained from this study will be helpful in designing the sediment and river management strategies for other similar river watersheds.
259

Acetate Modulation of Fatty Acid and Triacylglycerol Synthesis-related Gene Expression in Chlamydomonas reinhardtii for Nitrogen Starvation Induced Lipid Accumulation

Wu, Pei-shan 01 September 2010 (has links)
Diacylglycerol acyltransferase (DGAT) is a key for the synthesis of triacylglycerol (TAG) from diacylglycerol in the unicellular green alga Chlamydomonas reinhardtii.Acetyl-CoA carboxylase (ACCase) and fatty acid synthase (FAS) are responsible for the synthesis of fatty acids. We found the TAG and fatty acid synthesis related genes in C. reinhardtii, including five DGAT (DGAT1 (JGI 184281), DGAT2 (JGI 400751), DGAT3 (JGI 285889), DGAT4 (JGI 141301), and DGAT5 (JGI 190539)), three £] ketoacyl-ACP reductase isoforms ( (JGI 153976), (JGI 153976), and (JGI 194728)) and two £] ketoacyl-ACP synthase isofroms ( (JGI 139619) and (JGI 205887)) for FAS, and ACC £\ (NCBI XP_001696945.1), ACC £] (NCBI XP_001703187.1) and ACC biotin carboxylase ( NCBI XP_001702319.1)) for ACCase in C. reinhardtii. This investigation designed the primers of the above genes to determine whether acetate influences their mRNA expression levels in cell-wall less strain CC400 in the nitrogen starvation condition. The results showed that the absence of nitrogen in the medium triggered the lipid accumulation for the strains of CC400 in the condition of 50 £gE light. DGAT3 mRNA levels were increased by nitrogen starvation. For the FAS genes, in the strain of CC400 showed no increased mRNA levels upon exposure to nitrogen starvation. The mRNA levels of ACC£\, ACC £] and ACC biotin carboxylase were more or less decreased by nitrogen starvation in CC400 strains. Thus, the responses of DGAT gene expression to acetate supplement were checked. The absence of acetate from the medium partly inhibited the nitrogen starvation induced increases in lipid and DGAT3 mRNA levels, and the mRNA levels of DGAT1 and DGAT2 in the nitrogen starvation condition. However, DGAT4 mRNA levels were significantly induced by the absence of acetate from the medium. In conclusion, the present study demonstrate that acetate is required for the nitrogen starvation induced DGAT3 gene expression (mRNA levels) and lipid accumulation in C. reinhardtii.
260

Systemic POMC Overexpression Increases Visceral Fat Accumulation in Mice

Tang, Chia-Hua 16 February 2011 (has links)
Proopiomelanocortin (POMC) is a polypeptide precursor with 241 amino acid residues which undergoes extensive post-translational modification to yield a range of smaller, biological active peptides including £\-, £] -, £^-melanocyte-stimulating hormone (£\-MSH, £]-MSH, £^-MSH )¡A£]-endorphin (£]-EP) and adrenocorticotrophic hormone (ACTH). POMC-derived peptides play important roles in appetite and energy homeostasis. Recently, the peripheral POMC system is under active investigation to delineate their pathogenic roles in metabolic diseases such as Cushing¡¦s syndrome and obesity. In the present study, we utilized adenovirus gene delivery system to achieve systemic POMC overexpression in adult C57/BL6 mice for at least 30 days. Subsequently, the plasma and abdominal adipose tissue of mice were collected and analyzed by biochemical assays and weight determination respectively. POMC overexpression did not increase in the food uptake and body weight. These results imply that local POMC gene delivery induced the visceral fat accumulation and altered the metabolism in mice. It was observed that systemic POMC overexpression significantly elevated the triglyceride and the cholesterol levels in mice. However, POMC gene delivery also induced elevated plasma glucose concentration at weeks 1-4 and evoked glucose tolerance in mice at week 4. Interestingly, insulin resistance was readily detected in POMC-transduced in mice at as early as week 1. Besides, Micro-CT scanning and histological studies demonstrated that the visceral fat was significantly increased in POMC over-expressing mice compared with control animals. These data indicate that hepatic POMC gene delivery causes systemic ACTH rise and insulin resistance, which recapitulates the clinical features of Cushing¡¦s syndrome. In summary, POMC gene delivery induces systemic POMC overexpression and results in visceral fat accumulation and insulin resistance, which may facilitates a mice model for Cushing¡¦s-like metabolic syndrome.

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