• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 28
  • 12
  • 6
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 63
  • 14
  • 12
  • 7
  • 7
  • 6
  • 5
  • 5
  • 5
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 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.
1

An analysis of the Topeka Kansas downtown district to determine a process of rejuvenation

Munz-Pritchard, Christine Patricia January 1900 (has links)
Master of Regional and Community Planning / Department of Architecture and Regional and Community Planning / John W. Keller / This report is a reconnaissance analysis of the Topeka, Kansas downtown district to determine a process of rejuvenation. Many office buildings are established in or near the downtown core, and bring an estimated 30,000 employees to the area; however, after 5:00 PM much of the work force leaves the downtown making it difficult for retail and entertainment businesses to stay open. The purpose of this study is to analyze the downtown district of Topeka in terms of its strengths and weaknesses, and determine the steps that must be taken before a process of rejuvenation can occur. To accomplish this, the study examines strategic data such as a workforce profile, location information, public facilities, historical and current demographics of the city, along with specific information on the downtown area such as past and present plans for renovation. This analysis also includes current plans in the downtown and how they might impact the future physical development of the central core of downtown Topeka such as the potential realignment of Interstate 70. The key to making any downtown project a success is to acknowledge the weaknesses and threats of the area and to recast them as potential opportunities and strengths for the area. This is why the study has a building survey and a S.W.O.T. (Strengths, Weaknesses, Opportunities, and Strengths) analysis.
2

Rejuvenation of the campus core

Bhebhe, Thabo 27 November 2008 (has links)
The University of Pretoria is an international institution that has seen many of its alumni carry its good reputation and high standards into the global community. A well rounded student is one who has not only achieved academically, but also has learnt life skills through exposure to different people from all walks of life. The Core Student Centre is the heart of the University's campus that belongs to the students. It is a place where students will feel like they belong, and be unconsciouslyb encouraged to interact with fellow students. Branding in architecture is the vehicle through which centralised management,student ownership and consistency in high standards of service will keep the Core Student Centre as the hub of student activity on the University's campuses. The main campus in Hatfield is the pilot project, then the rest of the University's campuses will have their student centres adapted to have the Core brand be a campus-wide initiative. The students will then know to expect nothing but high quality standards associated with the brand. Copyright 2008, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Bhebhe, T 2008, Rejuvenation of the campus core, MInt(Prof) dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-11272008-154959 / > C169/eo / Dissertation (MInt(Prof))--University of Pretoria, 2009. / Architecture / unrestricted
3

Cooling Before Super-Eruption: No Role for Rejuvenation in the Cottonwood Wash Tuff Magma Body, Southern Great Basin Ignimbrite Province, Utah and Nevada

Ross, Keryn Tobler 01 December 2015 (has links)
The model of rejuvenation of a near-solidus crystal mush to produce large volumes of crystal-rich magma is tested here by analyzing the mineralogical, chemical, modal, and physical characteristics of the 31.1 Ma super-eruptive (2000 km3) Cottonwood Wash Tuff. It is the oldest in a series of three so-called "monotonous intermediate" ignimbrites from the Indian Peak-Caliente volcanic field in southern Utah and Nevada. A crystal-rich (~50% Pl > Qz ≈ Hbl ≈ Bt > Mag ≈ Ilm > Cpx + Zrn + Ap+ Po) dacite (62 - 69 wt% SiO2), the Cottonwood Wash Tuff is similar in age, volume, mineralogy, crystallinity, and elemental composition to the 28.0 Ma, ~5000 km3 Fish Canyon Tuff (~45% Pl + Kfs + Qz + Hbl + Bt + Ttn + Mag + Ilm + Ap + Zrn + Po, 66 - 68 wt% SiO2), used as the basis of the rejuvenation model, which suggests that magma chambers remain in a near-solidus state until a late heating event melts the magma enough to allow eruption. The Cottonwood Wash magma chamber was compositionally varied, as shown by the composition of mineral and juvenile clast compositions. Most of the whole-rock compositional variations are likely due to the variation of mineral proportions induced by shear in the magma chamber. A volumetrically minor component with evolved mineral compositionss, is represented by "evolved" juvenile clasts. Mineral compositions and experimental phase relationships show the pre-eruption magma crystallized at 800°C, 2.3 kb under water-undersaturated but oxidized conditions (delta QFM = 2.1). The majority of plagioclase and amphibole grains exhibit small-scale oscillatory zonation; where systematic compositional zonation exists, normal and reverse zonation are equally present. Cathodoluminescence of quartz reveals typically normally zoned phenocrysts with late resorption, considered to be the result of eruptive decompression. Many of the characteristics used to identify the warming of a near-solidus mush for the Fish Canyon Tuff are not present in the Cottonwood Wash Tuff [i.e., reversely zoned hornblende or plagioclase, partially remelted mineral aggregates, evidence of fluid saturation, resorption textures not related to decompression, rapakivi mantles, and hybrid andesite inclusions]. The Cottonwood Wash Tuff magma system did not undergo rejuvenation from a near-solidus state. Instead, the magma was apparently cooling and crystallizing just prior to eruption.
4

Cooling Before Super-Eruption: No Role for Rejuvenation in the Cottonwood Wash Tuff Magma Body, Southern Great Basin Ignimbrite Province, Utah and Nevada

Ross, Keryn Tobler 01 December 2015 (has links)
The model of rejuvenation of a near-solidus crystal mush to produce large volumes of crystal-rich magma is tested here by analyzing the mineralogical, chemical, modal, and physical characteristics of the 31.1 Ma super-eruptive (2000 km3) Cottonwood Wash Tuff. It is the oldest in a series of three so-called “monotonous intermediate” ignimbrites from the Indian Peak-Caliente volcanic field in southern Utah and Nevada. A crystal-rich (~50% Pl > Qz ≈ Hbl ≈ Bt > Mag ≈ Ilm > Cpx + Zrn + Ap+ Po) dacite (62 – 69 wt% SiO2), the Cottonwood Wash Tuff is similar in age, volume, mineralogy, crystallinity, and elemental composition to the 28.0 Ma, ~5000 km3 Fish Canyon Tuff (~45% Pl + Kfs + Qz + Hbl + Bt + Ttn + Mag + Ilm + Ap + Zrn + Po, 66 – 68 wt% SiO2), used as the basis of the rejuvenation model, which suggests that magma chambers remain in a near-solidus state until a late heating event melts the magma enough to allow eruption. The Cottonwood Wash magma chamber was compositionally varied, as shown by the composition of mineral and juvenile clast compositions. Most of the whole-rock compositional variations are likely due to the variation of mineral proportions induced by shear in the magma chamber. A volumetrically minor component with evolved mineral compositionss, is represented by “evolved” juvenile clasts. Mineral compositions and experimental phase relationships show the pre-eruption magma crystallized at 800°C, 2.3 kb under water-undersaturated but oxidized conditions (delta QFM = 2.1). The majority of plagioclase and amphibole grains exhibit small-scale oscillatory zonation; where systematic compositional zonation exists, normal and reverse zonation are equally present. Cathodoluminescence of quartz reveals typically normally zoned phenocrysts with late resorption, considered to be the result of eruptive decompression. Many of the characteristics used to identify the warming of a near-solidus mush for the Fish Canyon Tuff are not present in the Cottonwood Wash Tuff [i.e., reversely zoned hornblende or plagioclase, partially remelted mineral aggregates, evidence of fluid saturation, resorption textures not related to decompression, rapakivi mantles, and hybrid andesite inclusions]. The Cottonwood Wash Tuff magma system did not undergo rejuvenation from a near-solidus state. Instead, the magma was apparently cooling and crystallizing just prior to eruption.
5

Plant and soil responses to fertilization of grasslands in Saskatchewan, Canada and Selenge, Mongolia

Lkhagvasuren, Bayartulga 23 May 2007
Studies were conducted at three different sites in Saskatchewan, Canada (Colonsay, Vanscoy and Rosthern) over two years (2005 and 2006) to determine the effect of dribble banded and coulter injected liquid fertilizer applied in the spring of 2005 at 56, 112 and 224 kg N ha-1 with and without P at 28 kg P2O5 ha-1. A similar study was conducted in 2006 at one site in Mongolia to determine the effect of granular N and P fertilizer application on dry matter yield, and N and P concentration in plant biomass in the year of application (2006) only. The three Saskatchewan sites were unfertilized, 7-8 year old stands of mainly meadow bromegrass (<i>Bromus riparius</i>) dominated haylands, while the Mongolia site was mixed species of native rangeland.<p>All fertilization treatments produced significantly (p≤0.05) higher dry matter yield than the control in the year of application at the three Saskatchewan sites. The addition of 28 kg P2O5 ha-1 P fertilizer along with the N fertilizer did not have a significant effect on yield in most cases. In the year of application, increasing N rates above 56 kg N ha-1 did not significantly increase yield over the 56 kg N ha-1 rate in most cases but did increase N concentration, N uptake and protein content. A significant residual effect was found in the high N rate treatments in 2006, with significantly higher yield and N uptake. In 2005, the forage N and P uptake were in all cases significantly higher than the control in the fertilized treatments. The N uptake at the three Saskatchewan sites increased with increasing N rate up to the high rate of 224 kg N ha-1, although the percent recovery decreased with increasing rate. The P fertilization with 28 kg P2O5 ha-1 also increased P uptake at the three Saskatchewan sites. The site in Mongolia was less responsive to fertilization than the three Saskatchewan sites, with only a significant response in yield, N uptake and no significant effect of P fertilization. <p>For incubation soil cores collected in the fall of 2006, mean respiration rates were similar among the fertilized treatments at all the sites and the pattern of CO2 and N2O evolution measured over a two-week period showed similar trend at the three sites, with no significant difference between treatments. However a significant increase in gas production occured as the soils were wetted during the incubation. By the fall of 2005, the fertilization effect had likely diminished along with available substrate for the soil microbial biomass.<p>Overall, rates of fertilizer of approximately 50 kg N ha-1 appear to be sufficient to produce nearly maximum yield and protein concentration of the grass in the year of application for the Saskatchewan and Mongolia sites. Surface banding placement was as effective as in soil placement and there was limited response to P fertilization. A small amount of N fertilizer that is surface-placed on these grass dominated forage systems appears to be an effective means of increasing production in the year of application. Higher rates are needed to sustain the rejuvenation beyond one year.
6

Plant and soil responses to fertilization of grasslands in Saskatchewan, Canada and Selenge, Mongolia

Lkhagvasuren, Bayartulga 23 May 2007 (has links)
Studies were conducted at three different sites in Saskatchewan, Canada (Colonsay, Vanscoy and Rosthern) over two years (2005 and 2006) to determine the effect of dribble banded and coulter injected liquid fertilizer applied in the spring of 2005 at 56, 112 and 224 kg N ha-1 with and without P at 28 kg P2O5 ha-1. A similar study was conducted in 2006 at one site in Mongolia to determine the effect of granular N and P fertilizer application on dry matter yield, and N and P concentration in plant biomass in the year of application (2006) only. The three Saskatchewan sites were unfertilized, 7-8 year old stands of mainly meadow bromegrass (<i>Bromus riparius</i>) dominated haylands, while the Mongolia site was mixed species of native rangeland.<p>All fertilization treatments produced significantly (p≤0.05) higher dry matter yield than the control in the year of application at the three Saskatchewan sites. The addition of 28 kg P2O5 ha-1 P fertilizer along with the N fertilizer did not have a significant effect on yield in most cases. In the year of application, increasing N rates above 56 kg N ha-1 did not significantly increase yield over the 56 kg N ha-1 rate in most cases but did increase N concentration, N uptake and protein content. A significant residual effect was found in the high N rate treatments in 2006, with significantly higher yield and N uptake. In 2005, the forage N and P uptake were in all cases significantly higher than the control in the fertilized treatments. The N uptake at the three Saskatchewan sites increased with increasing N rate up to the high rate of 224 kg N ha-1, although the percent recovery decreased with increasing rate. The P fertilization with 28 kg P2O5 ha-1 also increased P uptake at the three Saskatchewan sites. The site in Mongolia was less responsive to fertilization than the three Saskatchewan sites, with only a significant response in yield, N uptake and no significant effect of P fertilization. <p>For incubation soil cores collected in the fall of 2006, mean respiration rates were similar among the fertilized treatments at all the sites and the pattern of CO2 and N2O evolution measured over a two-week period showed similar trend at the three sites, with no significant difference between treatments. However a significant increase in gas production occured as the soils were wetted during the incubation. By the fall of 2005, the fertilization effect had likely diminished along with available substrate for the soil microbial biomass.<p>Overall, rates of fertilizer of approximately 50 kg N ha-1 appear to be sufficient to produce nearly maximum yield and protein concentration of the grass in the year of application for the Saskatchewan and Mongolia sites. Surface banding placement was as effective as in soil placement and there was limited response to P fertilization. A small amount of N fertilizer that is surface-placed on these grass dominated forage systems appears to be an effective means of increasing production in the year of application. Higher rates are needed to sustain the rejuvenation beyond one year.
7

Programming Language Evolution and Source Code Rejuvenation

Pirkelbauer, Peter Mathias 2010 December 1900 (has links)
Programmers rely on programming idioms, design patterns, and workaround techniques to express fundamental design not directly supported by the language. Evolving languages often address frequently encountered problems by adding language and library support to subsequent releases. By using new features, programmers can express their intent more directly. As new concerns, such as parallelism or security, arise, early idioms and language facilities can become serious liabilities. Modern code sometimes bene fits from optimization techniques not feasible for code that uses less expressive constructs. Manual source code migration is expensive, time-consuming, and prone to errors. This dissertation discusses the introduction of new language features and libraries, exemplifi ed by open-methods and a non-blocking growable array library. We describe the relationship of open-methods to various alternative implementation techniques. The benefi ts of open-methods materialize in simpler code, better performance, and similar memory footprint when compared to using alternative implementation techniques. Based on these findings, we develop the notion of source code rejuvenation, the automated migration of legacy code. Source code rejuvenation leverages enhanced program language and library facilities by finding and replacing coding patterns that can be expressed through higher-level software abstractions. Raising the level of abstraction improves code quality by lowering software entropy. In conjunction with extensions to programming languages, source code rejuvenation o ers an evolutionary trajectory towards more reliable, more secure, and better performing code. We describe the tools that allow us efficient implementations of code rejuvenations. The Pivot source-to-source translation infrastructure and its traversal mechanism forms the core of our machinery. In order to free programmers from representation details, we use a light-weight pattern matching generator that turns a C like input language into pattern matching code. The generated code integrates seamlessly with the rest of the analysis framework. We utilize the framework to build analysis systems that find common workaround techniques for designated language extensions of C 0x (e.g., initializer lists). Moreover, we describe a novel system (TACE | template analysis and concept extraction) for the analysis of uninstantiated template code. Our tool automatically extracts requirements from the body of template functions. TACE helps programmers understand the requirements that their code de facto imposes on arguments and compare those de facto requirements to formal and informal specifications.
8

Links between Germline and Longevity in Caenorhabditis elegans / Étude des mécanismes moléculaires liant la lignée germinale au vieillissement chez Caenorhabditis elegans

Goudeau, Jérôme 30 June 2011 (has links)
Un nouveau gène de la longévité ouvre de nouvelles pistes pour vieillir mieux. L'accroissement de la longévité induit par la suppression des tissus reproducteurs a été observé chez la drosophile et chez le ver. Chez ce dernier, l'opération lui donne 60% de vie en plus et lui permet un vieillissement harmonieux et en bonne santé. Les mécanismes moléculaires qui induisent cette réponse font l'objet d'intenses recherches. Certains gènes étaient déjà connus pour être associés à l'accroissement de la longévité des vers sans lignée germinale, et nous avons démontré l'existence d'une nouvelle voie impliquant le récepteur nucléaire NHR-80. Les nématodes dépourvus de lignée germinale et dont nhr-80 est muté ne voient pas leur longévité augmenter. En outre, la surexpression du gène allonge davantage leur durée de vie: elle est 150% plus longue que celle de leurs congénères sauvages. Cela démontre l'importance de ce récepteur nucléaire dont l'activation par une hormone encore inconnue enclenche l'expression ou la mise sous silence de centaines d'autres gènes. Notamment, nous avons montré que l'une des cibles de NHR-80, l'enzyme FAT-6 qui transforme l'acide stéarique en acide oléique est fondamentale, puisque les vers dépourvus de lignée germinale ne présentent plus aucun gain en longévité en l'absence de FAT-6. À terme, nous espérons pouvoir récapituler les effets de l'ablation de la lignée germinale chez un organisme fertile, c'est à dire, d'induire les réarrangements métaboliques qui ont lieu suite à cette opération afin d'en tirer les effets positifs sur la santé, sans affecter la reproduction. / Discovery of a key longevity gene opens new perspectives for healthy aging.Increased longevity induced by reproductive tissues removal (germline ablation) is observed in the fly Drosophila melanogaster and in the worm Caenorhabditis elegans. In the latter, the operation increases lifespan by 60%, and enables the nematode to age harmoniously and in good health. The molecular mechanisms that induce this response are subject of intensive research. Our study reveals the existence of a new powerful longevity gene, nhr-80, which mediates this longevity effect. We have shown that inactivation of nhr-80 prevents lifespan increase. Furthermore, nhr-80 overexpression lengthens the nematodes' lifespan by 150%! nhr-80 encodes a nuclear receptor, which activation by a still unknown hormone controls the expression of hundreds of other genes. We showed that one of the critical NHR-80 targets, the enzyme FAT-6, which transforms stearic acid into oleic acid, is necessary to prolong lifespan since a mutation of the fat-6 gene suppresses the effects of germline ablation on longevity. The next step will be to determine how an increase in the level of oleic acid induces an adaptive response resulting in increased longevity. This research may lead to the exciting possibility of recapitulating the benefits of germline ablation in fertile animals; in other words, to activate the longevity effects normally triggered by germline ablation in order to fight, in one go, a host of diseases associated with aging, without affecting reproduction.
9

Software rejuvenation in cluster computing systems with dependency between nodes

Yang, M., Min, Geyong, Yang, W., Li, Z. 17 March 2014 (has links)
No / Software rejuvenation is a preventive and proactive fault management technique that is particularly useful for counteracting the phenomenon of software aging, aimed at cleaning up the system internal state to prevent the occurrence of future failure. The increasing interest in combing software rejuvenation with cluster systems has given rise to a prolific research activity in recent years. However, so far there have been few reports on the dependency between nodes in cluster systems when software rejuvenation is applied. This paper investigates the software rejuvenation policy for cluster computing systems with dependency between nodes, and reconstructs an stochastic reward net model of the software rejuvenation in such cluster systems. Simulation experiments and results reveal that the software rejuvenation strategy can decrease the failure rate and increase the availability of the cluster system. It also shows that the dependency between nodes affects software rejuvenation policy. Based on the theoretic analysis of the software rejuvenation model, a prototype is implemented on the Smart Platform cluster computing system. Performance measurement is carried out on this prototype, and experimental results reveal that software rejuvenation can effectively prevent systems from entering into disabled states, and thereby improving the ability of software fault-tolerance and the availability of cluster computing systems. / National Natural Science Foundation of China under the grant No. 60872044, 71133006, and Fundamental Research Funds for the Central Universities, and the Research Funds of Renmin University of China.
10

Rejuvenating & Quenching: Gas Properties of Transitional Galaxies

Lazarus, Dylan January 2023 (has links)
Most galaxies are either actively forming stars or quenched, but there is a small number of galaxies in transition from one population to the other. These galaxies are "quenching" if they are in the process of becoming quenched or "rejuvenating" if they are returning to the star-forming main sequence after a period of being quenched. Quenching occurs when a galaxy’s limited cold gas supply is heated or removed, halting star formation, while rejuvenation refers to any process that reintroduces cold gas to quenched galaxies, reigniting star formation. Rejuvenating galaxies, which are significantly rarer and less well-studied than quenching galaxies, can offer valuable insights into galaxy evolution processes. This thesis investigates the properties of transitional galaxies, with a focus on their gas content, to explore the mechanisms driving quenching and rejuvenation. We employ a recent classification method using GALEX NUV and Sloan Digital Sky Survey H-alpha measurements to identify transitional galaxies and analyze the derived gas properties of those in the xGASS and xCOLD GASS surveys. We find that rejuvenating and quenching galaxies have intermediate gas fractions compared to actively star-forming and quenched galaxies, and that rejuvenating and quenching galaxies have similar depletion times to star-forming and quenched galaxies, respectively. We also find that the rejuvenating population, particularly at lower stellar mass, is efficient at converting its atomic gas supply to molecular hydrogen, which could be attributed to their high gas-phase metallicities at low stellar mass. / Thesis / Master of Science (MSc)

Page generated in 0.4313 seconds