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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.
691

Kaikaku in production

Yamamoto, Yuji January 2010 (has links)
In today’s fast-changing and dynamic business environment, the pressures on manufacturing companies to compete on the global arena have been intensified. Production is challenged to handle and benefit from ever increasing competitions in terms of cost, delivery capability, and flexibility. In order to gain and sustain the competitive advantage under such circumstances, strong and constant development of production must be ensured not only with continuous improvements but also with radical improvements. Continuous improvement or called Kaizen has been an established approach of production improvement. The concept of Kaizen is well described and many tools and methods that support Kaizen have been developed and widely applied in industry. However, for radical improvement or “Kaikaku” in Japanese, the need and the importance of Kaikaku are still limitedly recognized at companies. Moreover, the knowledge of structured support that facilitates an effective and efficient execution of Kaikaku has been insufficiently developed. The purpose of the research presented in this thesis is to develop models and methods that address the need and the importance of Kaikaku in production and facilitate the realization of it. The research consists of a literature study and three case studies. The literature study was conducted in order to structure the concept of Kaikaku. As a result of the study, a conceptual framework of Kaikaku was developed. The three case studies were conducted to identify influential factors to the realization of Kaikaku. Both Swedish and Japanese companies were studied and analyzed. These case studies led to identify a way of realizing a certain type of Kaikaku. Some characteristics of organization setting were also found influential to the realization of Kaikaku. To conclude, the research has contributed to creating a foundation of the research area related to Kaikaku. This has opened up opportunities for further research in this field.
692

Radikala ändringar av marknadsförhållanden och strategiska förändringar / Radical alterations of market conditions and strategic change

Curtsdotter, Jenny, Kihlborg, Louise January 2002 (has links)
There is much literature covering strategic change under different circumstances but very little concerning how companies act strategically under sudden and radical changes to market conditions. Based on three different events (the terrorist attack in the USA September 11th 2001, the Tjernobyl accident April 26th 1986 and the Islamic revolution in Iran 1979) with such radical changes as a result we chose three companies that were affected (SAS, Asea Atom and Atlas Copco). The result of the events that were studied in this thesis is extremely unusual to their character. The events themselves were sudden and of a temporary nature but the results were long term changes of market conditions. Through personal interviews the authors have tried to establish how the companies have perceived the events and how the top management has strategically handled the situation. It seems like the interpretation of the importance the event will have on the company's future has been the basis for what measures that where taken. Furthermore, the authors have, after having compared the actions of the companies with some already established theories concerning strategic change, been able to see that the existing theories cannotcompletely explain the actions of the companies and reactions under such extreme conditions. The time aspect and the resistance to change are factors that are affected by the radical changes of market conditions, since the planning of the changes takes place under a very compressed period of time, and the resistance to change that becomes unusually low within the company.
693

Radical Cyclization Approaches to Pyrrolidines

Beşev, Magnus January 2002 (has links)
Five-membered rings are readily prepared by 5-exo-trig radical cyclization. This thesis is concerned with novel methodology for pyrrolidine synthesis. We have synthesised selenium containing radical precursors from aziridines and α-phenylseleno ketones, and cyclized them to 2,4- and 3,4-disubstituted pyrrolidines. A few examples of 5-exo-dig cyclization were also demonstrated. In another study we investigated the capacity of the nitrogen protecting group to direct diastereoselectivity in the formation of 2,4-disubstituted pyrrolidines. The diphenylphosphinoyl protecting group directed cyclization to occur in a highly cis-selective manner. When cyclizations were performed at 17 oC, cis/trans-ratios as high as 24/1 were obtained. In contrast, cyclization of the unprotected pyrrolidine precursor afforded the trans-diastereomer as the major product (cis/trans = 1/3.3 – 1/20). We also examined the use of a hydroxyl auxiliary for controlling diastereoselectivity in radical cyclization. The required selenium containing radical precursors were synthesised from 2-cyanoaziridines by addition of organometallic reagents, reduction of the resulting aziridine ketone, and benzeneselenol ring-opening of the aziridine. Cyclization at 17 oC produced 2,4-disubstituted pyrrolidines substantially enriched in the trans-isomer (cis/trans = 1/9 – 1/12). Novel radical cyclization approaches to thiazolines and pyrrolines were also tried. The thesis also describes attempts to improve the Hassner aziridine synthesis by employing stannous chloride as a functional group tolerant reducing agent.
694

Challenges in Enzyme Catalysis - Photosystem II and Orotidine Decarboxylase : A Density Functional Theory Treatment

Lundberg, Marcus January 2005 (has links)
Possibly the most fascinating biochemical mechanism remaining to be solved is the formation of oxygen from water in photosystem II. This is a critical part of the photosynthetic reaction that makes solar energy accessible to living organisms. The present thesis uses quantum chemistry, more specifically the density functional B3LYP, to investigate a mechanism where an oxyl radical bound to manganese is the active species in O-O bond formation. Benchmark calculations on manganese systems confirm that B3LYP can be expected to give accurate results. The effect of the self-interaction error is shown to be limited. Studies of synthetic manganese complexes support the idea of a radical mechanism. A manganese complex with an oxyl radical is active in oxygen formation while manganese-oxo complexes remain inactive. Formation of the O-O bond requires a spin transition but there should be no effect on the rate. Spin transitions are also required in many short-range electron-transfer reactions. Investigations of the superproficient enzyme orotidine decarboxylase support a mechanism that involves an invariant network of charged amino acids, acting together with at least two mobile water molecules.
695

Fabrication of polymeric microfluidic devices via photocurable liquid monomers

Haraldsson, Klas Tommy January 2005 (has links)
Microfluidic devices have long been considered an ideal tool for rapid and inexpensive chemical analysis and reactions in areas ranging from point-of-care health to national security applications. However, fabricating microfluidic devices is time consuming, difficult and above all expensive. In commercial applications many thousand units need to be sold before the development costs are recovered. The problem is compounded since most microfluidic devices do not have generalized architectures which means that each end use requires a specialized design. The microfluidics marketplace can therefore be seen as being composed of 1000’s of niche markets. To address development costs, there is clearly a need for a versatile technology that can be used for many different applications and that enables rapid testing and optimization of new designs. This work describes such a technology: Contact Liquid Photolithographic Polymerization (CLiPP). The thesis consists of two parts: polymerization kinetics and the fabrication of polymeric microfluidic devices via CLiPP. The photopolymerization kinetics is evaluated for a number of monomer types, and the results are used to assess their suitability in the CLiPP process. Vinyl ether/maleate photoinitiated copolymerization is examined in detail. It is shown that the polymerization kinetics is dramatically influenced by the availability of easily abstractable hydrogens The presence of α-hydrogens adjacent to the vinyl ether functional group reduces the polymerization rate and the dependence of the polymerization rate as a function of initiation rate. Also, photoinitiated acrylate and methacrylate polymerization kinetics are presented. The kinetics results in these three monomer types are used to explain the different patterning properties of the monomer functionalities used in the CLiPP process, in which acrylates show enhanced patterning properties compared to methacrylates. The polymerization kinetics is studied with traditional tools and methods: photo Differential Scanning Calorimetry (photo-DSC), photo Fourier Transform Real Time Infrared Spectroscopy (photo-RTIR), and photo Real Time Electron Paramagnetic Spectroscopy (ESR). The microfluidic fabrication is performed via both in-house fabricated and commercially available CLiPP-specific hardware. The patterning qualities of the structures are evaluated via Scanning Electron Microscopy (SEM) and Optical Microscopy. The finished devices are used in their intended environment and evaluated in suitable manners to assess their utility. In this thesis, the development and design of specialized CLiPP fabrication machines, fabrication techniques and resulting microfluidic device features are presented anddiscussed. It is shown that the CLiPP scheme enables features such as 3 dimensional (3D) capabilities for minimized device footprints, a very large number of polymeric materials for optimized device components as well as facile integration of prefabricated components. Also, covalent layer adhesion and permanent surface modifications via living radical processes are demonstrated. These capabilities are exemplified in a number of examples that range from a 3D fluidic channel maze with separated fluidic streams and a device with independently moveable parts to a device constructed from multiple polymeric materials and devices with permanently modified surfaces, Also, batch processing capabilities are shown through fabrication of 400 identical undercut microstructures. Rapid and inexpensive design evaluations, multiple materials capabilities and the ability to seamlessly incorporate prefabricated microstructures of the CLiPP process strongly encourages continued method development. The future work that remains to be addressed is divided into two parts. First, to enable novel research devices, new polymer materials with enhanced mechanical and surface properties must be developed. Also, integration of prefabricated microstructures such as sensors and actuators has to be incorporated in a reproducible and rational manner. Secondly, to enable device mass fabrication, new automated equipment is to be developed in order to utilize the full batch processing potential of CLiPP. / QC 20101019
696

Oxidation of Organic Species in Ice

Gao, Shawna Shanshan 24 August 2011 (has links)
Oxidation of organic species, in particular dicarboxylic and humic acids, was investigated in ice. Products were analyzed by Proton Transfer Reaction Mass Spectrometry, ion and gas chromatography, and a Total Organic Carbon analyzer. Photolysis of succinic acid with H2O2, an OH precursor, produced malonic acid and malic acid, illustrating that diacids are subject to photochemical degradation in ice. First-order decay rate constants were an order of magnitude higher at room temperature (~23 °C) than in ice (-20 °C). A smaller difference was observed for malonic acid, a more soluble diacid, suggesting that partial segregation of H2O2 and succinic acid during freezing played an important role in the kinetics. VOCs, likely to be aldehydes and ketones, were produced from ice containing humic acid through heterogeneous ozonolysis and photooxidation which was enhanced by NO3-, an OH precursor. VOCs also formed from ice made from deionized water, likely through oxidation of organic contaminants.
697

Synthesis of Single Isomer Trisubstituted and Tetrasubstituted Olefins from E-β-Chloro-α-Iodo-α,β-Unsaturated Esters and Bergman Cycloaromatizations With and Without a Radical Trapping Agent

Pianosi, Anthony 30 November 2011 (has links)
Optimized methods for the regioselective and stereospecific synthesis of both trisubstituted and tetrasubstituted olefins as single isomers from E-β-chloro-α-iodo-α,β-unsaturated esters have been developed from previous work done in the Ogilvie lab. These optimized methods have led to the synthesis of trans isomeric enediynes that can be photoisomerized to their respective cis isomers and subsequently undergo microwave-assisted Bergman cycloaromatizations. Furthermore, both cis and trans isomeric enediynes that have propargyl ether substituents have been found to be able to undergo photoactivated Bergman cyclizations without the need for an intermolecular hydrogen donor. A mechanism study has confirmed that the Bergman cyclization products that form without the presence of an intermolecular hydrogen donor undergo a series of 1,5-hydrogen shifts as intermediates. A series of optimizations to these reactions were carried out, in part by utilizing electron-donating or electron-withdrawing functional groups to help stabilize the resulting radicals that form on the intermediates, and thus increase the yield of the associated Bergman cyclization products.
698

Red Scare Propaganda in the United States: A Visual and Rhetorical Analysis

Schroeder, Christy 04 January 2007 (has links)
This paper is a discussion and analysis of Red Scare propaganda from two different time periods: 1918-1921 and the 1940-50’s. Six examples of propaganda have been chosen and analyzed both visually and rhetorically. The paper also contains a discussion of the historical context and times surrounding the images, helping to place the texts within a proper framework for discussion. The six images are analyzed through Aristotle’s traditional rhetorical devices – ethos, pathos, and logos. Seven logical fallacies and drawn from this discussion of rhetoric and applied to the images as well. The images are visually analyzed in terms of stereotypes they uphold as well as the American ideology of “Americanism” that they allegedly support.
699

Comparative Analysis Of Domestic Security Issues Of Kazakhstan And Uzbekistan In The Post-soviet Era

Turgut, Arzu 01 January 2013 (has links) (PDF)
This thesis examines the main domestic security issues of Kazakhstan and Uzbekistan and the impact of their securitization processes on the domestic and regional security policies of these countries in the post-Soviet era. Two outstanding issues that have been securitized in these countries, separatism and ethnic conflict for Kazakhstan and radical Islam for Uzbekistan, are scrutinized in detail with a comparative analysis. This thesis argues that Kazakh and Uzbek leaders, Nursultan Nazarbayev and Islam Karimov, as the main securitizing actors in their countries have securitized the above-mentioned issues for certain political objectives in the chaotic order of the post-Cold War era. However, these securitization processes for both of these countries have become an obstacle to find permanent solutions to their domestic security problems and develop more effective security policies at the regional level. Kazakh and Uzbek leaders should renounce manipulating these problems and produce more comprehensive policies by paying equal attention to all other problems of their countries. In addition, Astana and Tashkent should try to ensure regional security rather than overemphasizing domestic one(s) if the aim is to benefit from an effective regional integration on Central Asian security. Contrary to the most of existing studies on the subject, the thesis argues that Kazakhstan and Uzbekistan are accepted as the active players that could contribute to the solution of their own security problems to a great extent, rather than being passive subjects of the &ldquo / New Great Game&rdquo / played among major actors.
700

Examining ethics from a moral point of view framework: a longitudinal analysis

Walker, Kent R. 27 July 2007 (has links)
By use of interview data, this thesis investigates how two moral points of view, the Conventional and Radical, held by study participants relate to: 1) factors that influence ethics; 2) role models of a self-defined well-lived life; 3) factors that help and hinder participants from living their well-lived life; and, 4) experience of pressures to compromise and freedom to live out their ideals within organizations. A longitudinal analysis is applied comparing participant moral point of view as students, to participant perceptions since entering the workforce as university graduates. The results show differences and similarities within the four areas of interest based on moral point of view. The implications of finding differences in participant perceptions based on moral point of view are discussed, and areas for future research are offered. / October 2006

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