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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.
171

ECONOMIC ANALYSIS OF NUTRIENT MANAGEMENT PRACTICES FOR WATER QUALITY PROTECTION

Amon-Armah, Frederick 03 October 2012 (has links)
The main purpose of this study was to evaluate the effect of alternative cropping systems on farm net returns, and nitrate-N and sediment yields in Thomas Brook Watershed (TBW). The study involved integrated bio-physical and economic optimization modelling. Crop yield and nitrate-N pollution response functions were estimated and then used in trade-off analysis between farm returns and environmental quality improvement. Five crop rotation systems were evaluated for seven fertilizer levels under conventional tillage (CT) and no-till systems (NT). Nitrate-N leached, as well as estimated maximum economic rate of N (MERN) fertilizer level and marginal abatement costs depended on crop type, rotation system, and tillage type. The most cost effective cropping systems that met restrictions on Health Canada maximum limit on nitrate-N in water included corn-corn-corn-alfalfa-alfalfa under NT for corn-based cropping systems, potato-winter wheat-carrot-corn under CT for vegetable horticulture-based and potato-barley-winter wheat-potato-corn under NT for potato-based cropping systems.
172

Multigenerational effects of selenium in rainbow trout, brook trout, and cutthroat trout

Pilgrim, Nicole L January 2012 (has links)
Selenium (Se) is an essential element, toxic at concentrations only slightly above those required. It can become detrimental to fish health when available in excess in the aquatic environment. This study examined the effects of Se on adult female rainbow trout, brook trout, and cutthroat trout fed Se-methionine for five months, and on their larvae. Differences between fish species and between tissues were observed in the accumulation of Se in adults, and dose-dependent effects of Se on plasma thyroid hormone concentrations in brook trout, gonad size in all three species, and indicators of oxidative stress in rainbow trout and cutthroat trout, were detected. Survival of larvae and swim-up success decreased with increasing egg Se concentrations in rainbow trout and cutthroat trout, however, the same effects were not observed in brook trout. Data from this study provide new evidence for species-specific Se accumulation and toxicity in salmonid fish. / xi, 123 leaves : ill. ; 29 cm
173

Analýza faktorů ovlivňujících přímý odtok z povodí / Analysis of factors affecting the direct runoff

VLASÁK, Ivo January 2016 (has links)
This diploma thesis deals with the analysis of the factors which influence the direct drainage from the drainage area. The thesis specifically deals with the drainage area of the Kopaninský brook. Drainage is always influenced by several factors at the same time. These factors are above all climate, anthropogenic impact, underdrainage, shape and extent of a drainage area, land use, geologic structure, location and altitude of a drainage area. The direct drainage can be separated by different methods (modificated semi-graphical method, GROUND method, method of hydrogram separation, method of digitals filtres) or CN- curves can be used for calculation. This thesis used the method of CN curves to process the results of a given drainage area. In the methodical part of the thesis I reached to the creation of direct drainage maps with the utilisation of the BPEJ maps together with the input data gained by the method of CN curves. These outputs were created at different values of design rains repetition time N= 2, 10, 50 and 100 years. The volume of a direct drainage was calculated by a classic method and by a method using the ArcMap programme. Another part of the thesis was simulation of different area utilisation situations (real condition versus grassing of ploughland) and saturation of drainage area, or more precisely water content in soil (dry soil, middle dry soil, wet soil).
174

Hydrologické simulace odtoků vody z povodí při srážko-odtokových událostech / Event-based rainfall-runoff modelling of the selected river basin

TICHÁČEK, Pavel January 2018 (has links)
This thesis deals with the event-based rainfall-runoff modelling of the selected river basin. This thesis is based on my previous work "Factors affecting the water discharge from the river basin during rainfall-runoff events". In that work I described factors, which have effect on water runoff from the river basin. This thesis was solved on basin of Jílecký stream. Water runoff from basin is affected with a number of factors, the most significant are slope of the terrain, soil saturation, geological and pedological conditions, vegetation cover and anthropogenic influence. Calculations of direct runoff were realised with method of CN curves, with using BPEJ map, land use map gained from Corine Land Cover 2006 and maximum daily precipitation sums with 2, 10, 20, 50 and 100 years probabilities recurrence obtained from the rainfall station Netřebice. Calculations were performed in a numerical method using vector data and a raster method performed in ArcMap. In the next step I performed simulations of various scenarios of change in river basic characteristics such as soil saturation change, grassing of arable land with a slope greater than 12°, grassing of all arable land and enlargement the built-up area in the river basin.
175

Analýza vývoje vegetačního krytu a využití země v povodích toků Novohradských hor (povodí Malše po soutok s Tichou, Tiché, Pohorského potoka po soutok Černou) / Analysis of land use and land cover development in the catchment areas of the water streams in the Novohradské Mountains (catchment areas of the Malše up to the confluence with the Tichá, of the Tichá and the Pohořský brook up to the confluence with the Černá)

JIRÁSEK, Petr January 2010 (has links)
The Dissertation submitted describes and analyses the development and existing situation of the landscape (in terms of land use and land & vegetation cover) in the {\clqq}Novohradské Mountains`` region between 1955 and 2009, in the cadastral district situated in the catchment areas of the Malše river, as well as of the Tichá river and of the Pohořský brook. On the basis of the statistical data of the Land Registry and detailed terrain mapping there have been analysed individual types of land and distribution of elements of the land cover in relation to individual cadastral districts. The results of the issues examined are contained in the Annexes to this Dissertation (tables, charts and figures) and are completed with verbal descriptions in the text part of Dissertation.
176

Ecology and impacts of nonnative salmonids with special reference to brook trout (<em>Salvelinus fontinalis</em> Mitchill) in North Europe

Korsu, K. (Kai) 06 October 2008 (has links)
Abstract My main objectives in this thesis were to explore general patterns and mechanisms driving salmonid invasions globally and, more specifically, to examine the invasion dynamics and impacts of the North American brook trout in North European stream systems. Non-native salmonids have often spread extensively and caused many harmful impacts on their native counterparts. Among the three globally introduced salmonids, the European brown trout appeared as the 'worst' alien species (strongest impact on native fish), followed by the North American rainbow trout and brook trout. Brook trout, which is widely established in European streams, was found to be a non-aggressive species. Moreover, the growth of brown trout was unaffected by brook trout, indicating negligible interspecific interactions between the two species. Habitat niche segregation between brook trout and brown trout was evident, with brook trout occupying mainly low-velocity pool habitats, whereas brown trout resided in fast-flowing riffles. At the river-wide scale, brook trout occurred mainly in small, slightly acid headwater streams, whereas brown trout was found primarily in larger downstream river sections. Evidently, North European streams with a very low number of native fish species offer underutilized niche space for tolerant headwater specialists such as brook trout. However, the habitat niche filled by brook trout was not completely vacant, as brown trout co-occurred with brook trout in numerous small and mid-sized (3–16 m wide) streams. In these streams, brown trout reproduction was negligible presumably related to the presence of brook trout. Brook trout had also increased in density relative to brown trout during the 10-yr study period (1994 vs. 2004). Moreover, the growth rate and population densities of brook trout were high and the species had spread extensively towards the upmost headwater streams during the 10-yr study period. Thus, harmful effects on the native brown trout by brook trout are likely to occur in the core habitat of the invader, i.e. headwater streams, leaving populations of the native species unaffected elsewhere. Due to the high conservation value of the potentially impacted populations of brown trout, I strongly caution against further stocking of brook trout in European watersheds.
177

From Transcendentalism to Progressivism: The Making of an American Reformer, Abby Morton Diaz (1821-1904).

Cro, Ann B. 06 May 2006 (has links) (PDF)
Author and activist Abby Morton Diaz (1821-1904) was a member of the Brook Farm Transcendental community from 1842 until it folded in 1847. Although critics have long recognized that Brook Farm played a role in Diaz's intellectual preparation, they have not attempted to demonstrate its influence through a study of her writings. In this study I will examine in detail two of Diaz's novels and two long essays, with passing references to other works, that reveal how the utopian socialism practiced at Brook Farm influenced Diaz as a writer and reformer. In all her writings Diaz emphasized the importance of education for women so that they may successfully fulfill their roles as wives, mothers, and their children's first teachers. Her philosophy is reflected in the reform initiatives she supported: the Women's Educational and Industrial Union and the Nationalist Party.
178

Authorship, History, and Race in Three Contemporary Retellings of the Mahabharata: The Palace of Illusions, The Great Indian Novel, and The Mahabharata (Television Mini Series)

Kalugampitiya, Nandaka M., 19 September 2016 (has links)
No description available.
179

Synthesis with Perfect Atom Economy: Generation of Furan Derivatives by 1,3-Dipolar Cycloaddition of Acetylenedicarboxylates at Cyclooctynes

Banert, Klaus, Bochmann, Sandra, Ihle, Andreas, Plefka, Oliver, Taubert, Florian, Walther, Tina, Korb, Marcus, Rüffer, Tobias, Lang, Heinrich 25 September 2014 (has links) (PDF)
Cyclooctyne and cycloocten-5-yne undergo, at room temperature, a 1,3-dipolar cycloaddition with dialkyl acetylenedicarboxylates 1a,b to generate furan-derived short-lived intermediates 2, which can be trapped by two additional equivalents of 1a,b or alternatively by methanol, phenol, water or aldehydes to yield polycyclic products 3b–d, orthoesters 4a–c, ketones 5 or epoxides 6a,b, respectively. Treatment of bis(trimethylsilyl) acetylenedicarboxylate (1c) with cyclooctyne leads to the ketone 7 via retro-Brook rearrangement of the dipolar intermediate 2c. In all cases, the products are formed with perfect atom economy.
180

Synthesis with Perfect Atom Economy: Generation of Furan Derivatives by 1,3-Dipolar Cycloaddition of Acetylenedicarboxylates at Cyclooctynes

Banert, Klaus, Bochmann, Sandra, Ihle, Andreas, Plefka, Oliver, Taubert, Florian, Walther, Tina, Korb, Marcus, Rüffer, Tobias, Lang, Heinrich 25 September 2014 (has links)
Cyclooctyne and cycloocten-5-yne undergo, at room temperature, a 1,3-dipolar cycloaddition with dialkyl acetylenedicarboxylates 1a,b to generate furan-derived short-lived intermediates 2, which can be trapped by two additional equivalents of 1a,b or alternatively by methanol, phenol, water or aldehydes to yield polycyclic products 3b–d, orthoesters 4a–c, ketones 5 or epoxides 6a,b, respectively. Treatment of bis(trimethylsilyl) acetylenedicarboxylate (1c) with cyclooctyne leads to the ketone 7 via retro-Brook rearrangement of the dipolar intermediate 2c. In all cases, the products are formed with perfect atom economy.

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