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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.
811

Genetic analysis of earliness traits in chickpea (<i>Cicer arietinum</i> L.)

Kabeta, Yadeta Anbessa 31 July 2007
The latter part of the reproductive growth phase in chickpea (<i>Cicer arietinum</i> L.) often coincides with declining temperature and wet conditions in western Canada, in sharp contrast to many other growing environments. This exacerbates the indeterminate nature of the crop, leading to excessive canopy development, and subsequently resulting in delayed maturity. The objectives of this study were to: i) determine the genetic relationships of short internode, double podding and early flowering traits with earliness of crop maturity; ii) determine the genetic control of major earliness traits in chickpea; iii) assess the patterns of post-flowering dry matter accumulation and partitioning to reproductive parts as related to earliness. <p>The results showed that double podding significantly reduced the number of days taken to maturity, under the conditions where this trait was sufficiently expressed. The best double podding genotypes, i.e. those with 1535% of the podded nodes bearing double pods, were about one week earlier than their single podding counterparts and standard checks. A physiological study revealed that the double podding parental genotype 272-2 partitioned a relatively greater proportion (about 58%) of the total dry matter to pods compared to 4254% in the single podding genotypes. Double podding increased the total number of pods set, and thus the increased demand for assimilates may have precluded further production of stems and leaves, resulting in an earlier transition of reproductive growth to physiological maturity. Days to flowering was positively associated with days to maturity, and partial path analysis revealed that days to flowering contributed to days to maturity indirectly via days to first pod maturity. Days to flowering explained 32% of the variation in days to first pod maturity. However, the short internode trait had an undesirable effect, in that all the short internode segregants were too late to mature. <p>Genetic studies revealed that days to flowering was determined by two major genes plus polygenes in chickpea in the short-season temperate environment of western Canada. The two major genes control over 65% of the phenotypic variation. Also, the additive component of genetic variance was significant for days to first podding, days to first pod maturity, reproductive period, and days to maturity; which is desirable for development of superior inbred cultivars of chickpea. These key phenological traits are interrelated but could be manipulated separately in the breeding process. Additional gain in earliness of crop maturity may be achieved through combined selection for these traits.
812

Fate and effects of copper in fluvial ecosystems: the role of periphyton

Serra Gasa, Alexandra 03 July 2009 (has links)
L'activitat humana és una de les majors causes d'elevades concentracions de nutrients i substàncies tòxiques en els ecosistemes fluvials. Entre la gran varietat de factors que alteren aquests ecosistemes, l'eutrofització i la contaminació per metalls pesants són dos dels principals problemes ambientals en països desenvolupats. Els biofilms fluvials (també anomenats comunitats perifítiques) representen una eina valuosa per avaluar els efectes dels contaminants (ex. nutrients i metalls) en els ecosistemes aquàtics. Aquest treball pretén investigar el destí i els efectes del Cu en els ecosistemes fluvials centrant-se en les comunitats perifítiques. Diferents metodologies han estat desenvolupades i/o adaptades per investigar específicament la dinàmica del Cu, la seva toxicitat i bioacumulació en comunitats perifítiques naturals, i la interacció entre l'eutrofització i la toxicitat del Cu en aquests ecosistemes. / Human activity is one of the major causes of elevated concentrations of nutrients and toxic substances in fluvial ecosystems. Among the many ecosystem stressors, eutrophication and metal pollution are two of the major environmental problems in many developed countries. Fluvial biofilms (periphyton communities) are a useful tool for monitoring the effects of pollutants (e.g. nutrients and metals) into aquatic ecosytems. The present study aims to investigate the fate and effects of Cu in fluvial ecosystems focusing on periphyton communities. Different methodologies have been developed and/or adapted to specifically investigate the dynamics of Cu, its toxicity and bioaccumulation on natural periphyton communities, and the interaction between eutrophication and Cu toxicity in these ecosystems.
813

The finance-dominated accumulation regime, income distribution and the present crisis

Stockhammer, Engelbert January 2009 (has links) (PDF)
The paper discusses the interactions of changes in income distribution and the accumulation dynamics in the post-Fordist accumulation regime in OECD countries, which is characterized by deregulated financial markets. The neoliberal mode of regulation came with a decisive shift in power relations at the expense of labor, which is clearly reflected in the fall of wage shares across OECD economies. The notion of a "finance-dominated" accumulation regime is proposed to highlight that financial developments crucially shape the pattern and the pace of accumulation. Financial globalization has relaxed balance of payment constraints and thereby allowed the build up of big international imbalances. The combination of real wage moderation and financial liberalization has led to different strategies (or at least outcomes) in different countries. While some countries (like the USA) exhibit a credit-fuelled consumption-driven growth model that comes with large current account deficits, others (like Germany and Japan) show an export-driven growth model with modest consumption growth and large current account surpluses. Overall the finance-dominated accumulation regime is characterized by a mediocre growth performance and by a high degree of fragility. (author´s abstract) / Series: Department of Economics Working Paper Series
814

Genetic analysis of earliness traits in chickpea (<i>Cicer arietinum</i> L.)

Kabeta, Yadeta Anbessa 31 July 2007 (has links)
The latter part of the reproductive growth phase in chickpea (<i>Cicer arietinum</i> L.) often coincides with declining temperature and wet conditions in western Canada, in sharp contrast to many other growing environments. This exacerbates the indeterminate nature of the crop, leading to excessive canopy development, and subsequently resulting in delayed maturity. The objectives of this study were to: i) determine the genetic relationships of short internode, double podding and early flowering traits with earliness of crop maturity; ii) determine the genetic control of major earliness traits in chickpea; iii) assess the patterns of post-flowering dry matter accumulation and partitioning to reproductive parts as related to earliness. <p>The results showed that double podding significantly reduced the number of days taken to maturity, under the conditions where this trait was sufficiently expressed. The best double podding genotypes, i.e. those with 1535% of the podded nodes bearing double pods, were about one week earlier than their single podding counterparts and standard checks. A physiological study revealed that the double podding parental genotype 272-2 partitioned a relatively greater proportion (about 58%) of the total dry matter to pods compared to 4254% in the single podding genotypes. Double podding increased the total number of pods set, and thus the increased demand for assimilates may have precluded further production of stems and leaves, resulting in an earlier transition of reproductive growth to physiological maturity. Days to flowering was positively associated with days to maturity, and partial path analysis revealed that days to flowering contributed to days to maturity indirectly via days to first pod maturity. Days to flowering explained 32% of the variation in days to first pod maturity. However, the short internode trait had an undesirable effect, in that all the short internode segregants were too late to mature. <p>Genetic studies revealed that days to flowering was determined by two major genes plus polygenes in chickpea in the short-season temperate environment of western Canada. The two major genes control over 65% of the phenotypic variation. Also, the additive component of genetic variance was significant for days to first podding, days to first pod maturity, reproductive period, and days to maturity; which is desirable for development of superior inbred cultivars of chickpea. These key phenological traits are interrelated but could be manipulated separately in the breeding process. Additional gain in earliness of crop maturity may be achieved through combined selection for these traits.
815

Flux Measurements of Volatile Organic Compounds from an Urban Tower Platform

Park, Chang Hyoun 2010 May 1900 (has links)
A tall tower flux measurement setup was established in metropolitan Houston, Texas, to measure trace gas fluxes from both anthropogenic and biogenic emission sources in the urban surface layer. We describe a new relaxed eddy accumulation system combined with a dual-channel gas chromatography - flame ionization detection used for volatile organic compound (VOC) flux measurements in the urban area, focusing on the results of selected anthropogenic VOCs, including benzene, toluene, ethylbenzene and xylenes (BTEX), and biogenic VOCs including isoprene and its oxidation products, methacrolein (MACR) and methyl vinyl ketone (MVK). We present diurnal variations of concentrations and fluxes of BTEX, and isoprene and its oxidation products during summer time (May 22 - July 22, 2008) and winter time (January 1 - February 28). The measured BTEX values exhibited diurnal cycles with a morning peak during weekdays related to rush-hour traffic and additional workday daytime flux maxima for toluene and xylenes in summer time. However, in winter time there was no additional workday daytime peaks due mainly to the different flux footprints between the two seasons. A comparison with different EPA National Emission Inventories (NEI) with our summer time flux data suggests potential underestimates in the NEI by a factor of 3 to 5. The mixing ratios and fluxes of isoprene, MACR and MVK were measured during the same time period in summer 2008. The presented results show that the isoprene was affected by both tail-pipe emission sources during the morning rush hours and biogenic emission sources in daytime. The observed daytime mixing ratios of isoprene were much lower than over forested areas, caused by a comparatively low density of isoprene emitters in the tower's footprint area. The average daytime isoprene flux agreed well with emission rates predicted by a temperature and light only emission model (Guenther et al., 1993). Our investigation of isoprene's oxidation products MACR and MVK showed that both anthropogenic and biogenic emission sources exist for MACR, while MVK was strongly dominated by a biogenic source, likely the isoprene oxidation between the emission and sampling points.
816

A Technique to Evaluate Snowpack Profiles in and Adjacent to Forest Openings

Ffolliott, Peter F., Thorud, David B. 20 April 1974 (has links)
From the Proceedings of the 1974 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 19-20, 1974, Flagstaff, Arizona / Profiles of snowpack build-up in openings in forest overstories have been widely observed; however, a quantitative characterization of such a snowpack profile would aid in developing empirical guidelines for improving water yields from snowpacks. A technique is outlined that illustrates (a) evaluating snowpack profiles in and adjacent to individual forest openings in terms of increase or decrease in water equivalent, and (b) defining trade-offs between the estimated increase or decrease in snowpack water equivalent and the forest resource removed. Snowpack water equivalent during peak seasonal accumulation was measured in and adjacent to a clearcut strip in a ponderosa pine stand in north-central Arizona. A 4-degree polynomial, which defines the snowpack profile in terms of deposition, redistribution, and ablation characteristics, was empirically selected to describe snowpack water equivalent data points. An increase of 60 percent in snowpack water equivalent was realized by removing 46 percent of the ponderosa pine in the zone of influence, using a strip equal to one and one-half the height of the adjacent overstory.
817

Επιχειρηματικότητα σε ορεινές περιοχές της Νότιας Ευρώπης / Entrepreneurship in mountainous areas of Southern Europe

Σταθοπούλου, Σοφία 25 June 2007 (has links)
Η διατριβή εξετάζει τους κρίσιμους παράγοντες που προσδιορίζουν την επιχειρηματικότητα της υπαίθρου, θέτει τα κύρια ερευνητικά ερωτήματα που σχετίζονται με ανάπτυξη και υποστήριξη της επιχειρηματικότητας στην ύπαιθρο και τέλος θέτει τις βάσεις για μία μελλοντική επιστημονική έρευνα. Οι περιοχές όπου βασίσθηκε η συγκεκριμένη διατριβή οριοθετούνται σε τέσσερις χώρες της Νότιας Ευρώπης: α) την Ελλάδα (Ευρυτανία)β) την Ιταλία (Garfagnana & Media Valle del Serchio) γ) την Ισπανία (Garrotxa) και δ) την Πορτογαλία (Serra-Algarvia). / The doctoral dissertation examines the crucial factors that determine rural entrepreneurship, it sets the basic research questions concerning the development and support of rural entrepreneurship and it also sets the framework for a future scientific research. The doctoral dissertation was based on four areas of Southern Europe: Evrytania (Greece); Garfagnana & Media Valle del Serchio (Italy); Garrotxa (Spain) and Serra-Algarvia (Portugal).
818

Untersuchungen zur Energiegewinnung mit einem Solardach-Luft-Kollektor / Investigations into the production of energy with a solar roof air heater

Baum, Matthias 15 July 2010 (has links)
No description available.
819

Ford and Futurism: Modern Time at the Panama-Pacific International Exposition

Belanger, Noelle Unknown Date
No description available.
820

Quantification of potential elemental impact of a munitions production and testing facility on its immediate surroundings / Unique Janse van Rensburg

Janse van Rensburg, Unique January 2010 (has links)
The study attempted to quantify the elemental concentrations and possible accumulation levels in the antelope's organ tissue at Rheinmetal Denel Munitions (RDM), as well as to correlate the findings with the surrounding environment. To achieve this, the elemental concentrations within the kidney, liver and lung tissue of the antelope, and environmental factors such as the soil, vegetation and waterholes were quantified. STATISTICA was used to determine meaningful differences between variables and Canoco to determine the relationship between the different datasets. PCA analyses of the vegetation confirmed that the natural slope at RDM could have contributed to the distribution and variation of the elemental concentration. It became apparent that positive associations existed between the liver tissue and the K, the kidney tissue and Ni and Cd, and the lung tissue had a positive association with Mg, Mn, V, Rb and Co elemental concentrations. It became evident in this study that the elemental concentrations of Al and Ni were higher in the liver and kidney tissue of the antelope than the recommended concentration for livestock (Puls, 1994). The elemental concentration of Al, Ca, Fe and Mn also exceeded the recommended elemental concentration for livestock, in the water sampled at RDM (Puls, 1994). Four distinct areas were identified within the study area, the area above the factory, the area under the factory, the testing area and the area under the factory. Significant differences between the testing area and the area under the factory were found regarding the Tl, Ag, Hg and B elemental concentrations in the vegetation. Furthermore, it became apparent that the amount of precipitation could have contributed to the variation of the elemental concentrations and distribution in the study area as well as in the organ tissue of the antelope. / Thesis (M.Sc. (Environmental Science and Management))--North-West University, Potchefstroom Campus, 2011.

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