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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.
301

Static Recovery of a Clad Aluminum Alloy After Cold Rolling

BAG, DEBARTHA 03 October 2011 (has links)
This study examines the static recovery behaviour of a clad aluminum alloy manufactured by Novelis FusionTM technology after 72% cold rolling. The clad alloy system studied consisted of a core AA6XXX alloy clad on one side with AA3003. The Recovery at the inter-alloy region is compared with the recovery of core AA6XXX at the same depth from the rolling surface. Sample coupons from the inter-alloy region and core AA6XXX were heated isochronally and isothermally, at different temperatures and times, respectively, to probe the recovery kinetics of the X-ray peak broadening, X-ray macro-texture and micro-hardness from the cold rolled state. The recovery of the {220} and {311} X-ray line profiles were observed between the anneals. A pseudo-Voigt fit function was fit to the profile to obtain the defect related information. Recovery in the peak broadening began by 100°C and correlated to a decrease in the hardness. Sharpening of X-ray profiles during recovery is attributed to the microstructural evolution resulting from preferred release of the stored energy due to dislocation rearrangement and annihilation. Kinetic behaviour of the recovery is measured by observing the evolution of X-ray profiles and hardness during isothermal annealing at two different temperatures. Recovery behaviour in the inter-alloy region is measured to be relatively slower than the recovery of the core AA6XXX after same macroscopic pre-strain. Activation energy for recovery is calculated from the isothermal data to deduce a recovery mechanism. The activation energy calculated in core AA6XXX, 1.7eV, is close to the activation energy value for diffusion of Mg in Al (1.3-1.7eV). This indicates a possible role of Mg diffusion in the recovery of AA6XXX. The relatively higher activation energy for recovery of 2.9eV measured in the inter-alloy region may be due to pinning by nano-scale Al-Mn precipitates. The X-ray broadening data is deconvoluted to determine the apparent dislocation content using a modified Williamson-Hall model. The dislocation density measured in the AA6XXX and inter-alloy regions in the deformed and recovered conditions indicates that dislocation density is a suitable parameter that represents the stored energy that drives subsequent structural evolution during recovery. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2011-09-30 19:02:44.02
302

THE ROLE OF DISPERSAL DURING THE RECOVERY OF ACID-DAMAGED ZOOPLANKTON COMMUNITIES

GRAY, DEREK 21 December 2011 (has links)
Ecologists studying acid-damaged zooplankton communities have often documented a time lag in recovery following pH increases. While previous work has provided a solid understanding of the local factors that may delay recovery (e.g. competition), less is known about the role of dispersal. The work in this thesis was conducted to test the hypothesis that dispersal limitation contributes to delays in the recovery of acid-damaged zooplankton communities. To assess the role of dispersal during recovery I pursued three objectives: 1) To measure dispersal in the field and determine the relative importance of various dispersal vectors for contributing acid-sensitive colonists to lakes; 2) to determine if spatial structure in recovering zooplankton communities exists across the landscape independent of environmental gradients; and 3) to determine if an interaction between dispersal and local environmental variables could influence recovery. Data collected for Objective 1 demonstrated that overland dispersal rates for acid-sensitive species in Killarney Park were relatively low, but some species were found emerging from the diapausing egg bank or dispersing through streams to recovering lakes. Spatial modeling and variation partitioning analyses for Objective 2 revealed spatial patterns indicative of dispersal limitation in recovering Killarney Park zooplankton communities. Enclosure experiments conducted for Objective 3 suggested that the colonization of the acid-sensitive copepod Epischura lacustris may be influenced by an interaction between dispersal levels and pH, such that higher dispersal levels may be required for establishment in lakes that are early in the process of pH recovery. Enclosure experiments also indicated that community resistance and low dispersal levels might hinder the reestablishment of the acid-sensitive copepod Skistodiaptomus oregonensis. Taken together, my results strongly suggest that dispersal limitation could contribute to delays in zooplankton community recovery. The recovery of acid-sensitive copepod species may be particularly difficult, as their reestablishment in recovering lakes appears to be influenced by Allee effects, community resistance, and an interaction between pH and dispersal levels. While dispersal rates could be artificially increased by human intervention, this would carry the risk of introducing invasive species. As a result, patience and continued monitoring of recovering lakes may be the best management approaches at this time. / Thesis (Ph.D, Biology) -- Queen's University, 2011-12-20 22:49:05.193
303

Role of Bitumen Viscosity in Bitumen Recovery from Athabasca Oil Sands

Zhang, Mei Unknown Date
No description available.
304

Nanostructured Environmental Barrier Coatings for Corrosion Resistance in Recovery Boilers

Rao, Shishir Unknown Date
No description available.
305

The im/possibility of recovery in Native North American literatures

Van Styvendale, Nancy Unknown Date
No description available.
306

Hot solvent injection for heavy-oil and bitumen recovery

Pathak, Varun Unknown Date
No description available.
307

Constructing hope in challenging spaces: narratives by health professionals on issues of solvent use

De Boer, Tracy 28 March 2013 (has links)
The process of recovery from addiction is a multifaceted process that involves the efforts of clients, professionals and the broader community. Additional challenges to recovery are present for individuals who use solvents. This study investigates how professionals, involved in the provision of services to clientele who use solvents, understand the process of healing in their collaborative work. Using a narrative methodology, semi-­‐structured interviews were conducted with professionals employed in providing recovery-based services to individuals who use volatile solvents. The stories of these professionals demonstrate how they view their clients as “just like everyone else” despite what the dominant cultural story says about their possibilities for recovery. The professionals told stories which are in extreme opposition to the story of dominant culture and involved groupings of “us” (professionals) versus “them” (others). These stories, and how they were told, are discussed in relation to hope for professionals who provide health and housing services.
308

The significance of social support in the recovery process from severe mental illness - A Case study from Uganda

Boström, Michaela January 2013 (has links)
This study aims to examine howdifferent forms of social support are perceived to affect the recovery process of people with severe mental health difficulties, and what factors people within this group perceive as being most beneficial for their recovery. This study was conducted in Uganda for eight weeks during November 2013 and December 2013 and is based on semi-structured interviews with people in recovery from severe mental illness such as bi-polar affective disorder and schizophrenia. This study is using Interpretative phenomenological analysis (IPA), which is a qualitative research approach, and the strength of IPA is its commitment to examine lived experience and personal meaning in detail. This study has shown that social support received from service user organisations was perceived to highly affect the recovery process in a most fundamental way. The service user organisations/associations were seen as platforms providing acceptance, understanding and recognition of what one has been or are going through. In terms of social support from family members, this was neither described as particularly helpful or hindering for the recovery process by most of the participants; this finding was somewhat unexpected but could be explained due to the complexity that proved to exist within the relationships between the participants and their family members. Medication was perceived as very important in terms of recovery, however it was strongly pointed out that medication alone was not enough. Despite this a majority of the participants had negative perceptions regarding both the dosage and the prescribed medicine itself particularly the prescription of Chlorpromazine, here feelings of being overmedicated and dealing with severe side effects were expressed, leading to some of the participants changing the prescribed dose on their own, so called manipulative medication.
309

Effect of a silver-bearing photoprocessing wastewater and silver compounds on biological treatment processes

Maeng, Sung Kyu 05 1900 (has links)
No description available.
310

Financial and non-financial information transfer and communication within small and medium enterprises.

Liu, Mengdi Mandy January 2012 (has links)
This participant-observation study explores the process of gathering and evaluating both financial and non-financial information and communication and transfer of that information within a medium-size Electrical Company in Christchurch, New Zealand. The previous literature has established the importance and the main characteristics of small and medium enterprises (SMEs), mainly studying manufacturing companies. However, there has been little research done in New Zealand on the overall communication process and the financial and non-financial information usage in a small-medium enterprise. Face-to-face interviews were carried out with all the office employees and two partners, along with a ten month participant-observation in the Electrical Company in order to understand how financial and non-financial information is communicated and processed in an SME. Also, research in an SME that has overcome the 2008 economic depression and several major earthquakes allows a deep understanding of lessons learned and what is valued by the Electrical Company. The research has found characteristics of this SME similar to those that have been mentioned in previous literature. However, the partners of the Electrical Company understand the importance of financial management and use financial information extensively to ensure the business expenses are under control. Moreover, the partners use more than just financial information to manage the company. They gather non-financial information through talking to their accountant, their customers and people in the same industry and they keenly follow the news on the rebuilding of Christchurch.

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