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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.
1

The effects of temperature and water potential on the germination of sorghum

Dunbabin, Timothy David January 1998 (has links)
Poor or failed crop establishment is a serious problem for farmers in the semi-arid tropics. Suboptimal stand densities or the necessity to re-sow can be a major factor in limiting crop yields. Establishment can be considered as the result of a set of complex interactions between the seed, the soil and the climate. The experiments detailed within this volume were carried out to determine parameters for sorghum germination for a model to predict crop emergence in the semi-arid tropics to aid the greater understanding of the causes of establishment problems. The cumulative germination of sorghum cv. Tegemeo was recorded in conditions of both constant temperatures and fluctuating temperatures on a thermogradient plate and at negative water potentials over a range of temperatures in solutions of polyethylene glycol and in soil. Results demonstrate that within a temperature range of 14 - 40oC germination can be predicted using a thermal time model. The effect of temperature fluctuation on the time to germination within this temperature range can be predicted using the same thermal time constants that model behaviour at constant temperatures. Prediction of the time to germination in soil using a hydrothermal model (Gummerson 1986) was found to be accurate over a wide range of temperatures (15 - 35oC) and soil matrix potentials (0 - -0.6 MPa). The results of this study have been incorporated into "EMERGE" (Mullins et al., 1996), a published crop emergence model. The potential use of hydrothermal modelling as a tool to investigate aspects of seed vigour is discussed.
2

The effect of seed and soil physical conditions on establishment of sorghum

Rwehumbiza, Filbert January 1994 (has links)
The studies reported here, used sorghum to: (i) investigate the effect of changes in the matric suction (m) of filter-paper on germination and water uptake (ii) assess the effect of seed vigour on seedling response to the m of filter paper and to soil mechanical impedance, (iii) investigate the effect of root-shoot interaction on establishment of seedlings subjected to mechanical impedance (MI), and (iv) evaluate the effects of different amounts of planting rain on crop establishment. A technique for controlling matric suction on seed test paper is described and used to study seed germination at m of 0.1, 1 and 10 kPa. Time to 50% germination was increased, and final lengths of both radicles and cleoptiles reduced by an increase in m from either 0.1 to 1, or 1 to 10 kPa. A link between filter paper m, seed-liquid contact area, seed size, the rate of water uptake and germination is discussed. Unimpeded, pregerminated low vigour and fresh seeds produced a similar root and shoot length, fresh mass, and number of leaves and lateral roots. When grown in compacted soil, low vigour seed took longer to emerge but only when seeds were severely aged. (i) Impedance to the shoot delayed emergence, more so when the root was also impeded. (ii) Shoots emerging through a mechanically impeding layer, had greater extension rates after emergence than unimpeded ones. (iii) Mesocotyls became thicker only when the root systems were impeded. (iv) Impeding the shoot system, increased root extension rate. (v) The length of the first internode, the number of leaves and the spacing of lateral roots were not changed by any of the treatments. Germination was >95% in sand columns watered with 5, 10 or 15 mm equivalents of rain. However, seedling emergence was <15% in the 5 mm compared to 77-100% in the 10 and 15 mm treatments. At harvest (9 DAP), all seedlings in the 5 mm treatment were dead. Seedlings given 10 mm rain showed signs of water stress. The interaction between seed vigour, the amount of water available to germinating seed, and soil mechanical impedance and their effect on crop establishment is discussed.
3

Market entry strategy : Four case studies of Swedish IT-businesses entering in Norway

Karlsson, Pernilla, Sarac, Edip, Mohsen, Zaid January 2012 (has links)
The trade today consist of global trade. Businesses are exercising cross-border activities and businesses tend to establish themselves in foreign markets. Many choices and factors affect a business choice of country to enter, and its choice of form of establishment in the new market. Therefore the thesis will examine the market entry strategy of the four Swedish businesses Lundalogik AB, Infobric AB, Funded-by-me AB, and PayEx AB in the information technology (IT) industry that have established their businesses in Norway. The authors believe that Norway is an interesting country to study as it is one of Sweden's most important ex-port markets and the IT-sector stands for approximately 13% of all Swedish exports towards the whole world. The purpose with the thesis is to explore and understand the market entry strategy used by the above mentioned four Swedish IT-businesses when entering the Norwegian market. With help of the purpose of the thesis the authors intend to answer what the underlying reasons for the four businesses were when entering the Norwegian market and its choice of form of establishment. As this is an explorative study the research method applied is an inductive approach with influences from the grounded theory. An inductive approach is when observations help to formulate a theory whereas the grounded theory is when a theory is discovered from social research. The reason why an inductive approach is better suited for the thesis is due to the flexibility in deciding which theory to choose after analyzing the primary data. After analyzing the four case studies it can be concluded that no pure internationalization strategy exists among the companies, instead a variety of customer follower and market seeker strategies are common. Moreover, the choice of form of establishment has many factors. Credibility, market knowledge, design of business and existing business relationships were the four most common factors identified by the authors affecting the case studies‟ choice of form of establishment.
4

Obchodní závod / Business establishment

Romanová, Renata January 2015 (has links)
Resumé In my thesis, I focus on issues related to the change of the concept of the business establishment, part of the business establishment and purchase of a business establishment in relation with the recodification of the Czech private law. After the introduction in the first chapter, the second chapter deals with the concept of business establishment. Business establishment within the meaning of section 502 of the Civil Code is a newly conceived as an organized set of assets and liabilities created by an entrepreneur, based on his will, are used to pursue his activities. A business establishment is presumed to comprise everything that is typically used for its operation. Thus, in accordance with the propositions of the European Court of Justice was to Czech private law enshrined the concept of the intent of the entrepreneur. The third chapter deals with the parts of the business establishment, specifically definition of the business establishment and reflection on the possibility of using jurisdiction and professional publications under the previous arrangements to similar issues. The fourth chapter deals with the purchase of the business establishment specified in the provisions of section 2175 et seq. Civil Code. In context of the new regulation on purchase of the business establishment, I focus on...
5

Challenging the Status Quo: The Rise and Consequences of Anti-Establishment Parties in Western Europe

Smith, Jason 2009 May 1900 (has links)
This dissertation examines two interconnected research questions: What conditions give rise and lead to the electoral success of anti-establishment parties and what are the consequences of this electoral success? Literature concerning anti-establishment parties fails to investigate this phenomenon in its entirety by focusing disproportionately on the electoral success of these parties neglecting the consequences of this electoral success. Although the electoral success of anti-establishment parties and the subsequent consequences have different theoretical underpinnings, the effects that anti-establishment parties have on individual parties and the party system are dependent upon the electoral success of these of parties. Therefore, this dissertation focuses on both the electoral success and the consequences of anti-establishment parties in Western Europe. Concerning electoral success, this dissertation offers a new approach to the literature by arguing that anti-establishment parties, regardless of their placement on the political spectrum, are born out of the dissatisfaction towards traditional parties within the electorate. Using quantitative analyses of eighteen Western European countries covering the time period 1970-2005, this dissertation offers a unified analysis of anti-establishment parties, regardless of their placement on the political spectrum, examining the political, social, and economic conditions that give rise to the anti-establishment party phenomenon. The findings indicate that while the factors leading to the emergence of anti-establishment parties may be the same regardless of the placement of these parties on the political spectrum, the factors leading to their electoral success are dependent upon their ideological orientation. Furthermore, the electoral success of these new parties has consequences for other individual parties and the broader party system. This dissertation argues that the existence of these parties alone is not enough to accomplish this aim; these parties must be seen as threats to existing mainstream parties on either the left or the right or in some cases, both. In order to counter the threat from these anti-establishment parties, traditional parties may change their ideological positions or organizational structures. Utilizing qualitative (face-to-face interviews with party elites) and evidence from party manifestos from 1970-2005 in six countries, these analyses indicate that the electoral success of anti-establishment parties affects individual parties by altering the ideological placement, particularly on issues relevant to anti-establishment party electoral success. To a lesser extent, traditional parties alter their organizational structures (i.e., allocating more power to rank-and-file members, regional, and local branches), in order to counter this new electoral threat. Moreover, the electoral success of anti-establishment parties causes instability within the broader party system. Utilizing quantitative, statistical methods to analyze eighteen western European countries between 1970 and 2005, this dissertation finds that the electoral success of anti-establishment parties increases the amount of electoral volatility and the amount of polarization both within the system and between traditional parties. However, anti-establishment parties do not mobilize the electorate leading to increases voter turnout in these eighteen countries. Finally, anti-establishment parties, by gaining seats in national legislatures, upset the traditional coalitional dynamics. As such, the electoral success of anti-establishment parties leads to shorter coalitional governments within the party systems of Western Europe.
6

Competitive Effects of Perennial Ryegrass and Chewings Fescue on Bermudagrass Seed Establishment

Gooch, C. Bryan 21 May 1998 (has links)
Perennial ryegrass (Lolium perenne L.) is widely used as a fairway turf on golf courses throughout the transition zone. The transition zone represents the geographical areas between the temperate and subtropical climates, where neither warm season nor cool season grasses are well adapted. The late-spring establishment of seeded bermudagrass could potentially enhance summer quality of a perennial ryegrass fairway during periods of extreme summer stress. Studies were conducted over two years on both perennial ryegrass and Chewings fescue (Festuca rubra L. ssp. commutata Gaud.) areas to assess the competitive effects of each species on bermudagrass seed establishment. The use of fungicides, herbicides and a plant growth regulator, as well as cultivation treatment prior to seeding, were evaluated for their effects on bermudagrass establishment, turfgrass quality, disease incidence and summer annual grass control. Turfgrass treated with preventative fungicide applications of propiconazole and chlorothalonil maintained high density and turf quality which inhibited successful establishment of bermudagrass during either year. Bermudagrass establishment in 1996 was moderately successful in plots not treated with fungicides; however, due to disease severity, turfgrass quality was unacceptable. MSMA applications did not influence turfgrass quality or bermudagrass establishment. Crabgrass populations were too low to ascertain the efficacy of either MSMA (1996) or oxadiazon (1997) on summer annual grass control. Oxadiazon followed by activated charcoal prior to bermudagrass seeding did not adversely affect bermudagrass establishment. In 1996, trinexapac-ethyl slightly enhanced bermudagrass seed establishment, but the competitiveness of perennial ryegrass prohibited establishment success. During 1997, glyphosate was evaluated as a means of eliminating competition and increasing bermudagrass establishment. Glyphosate applied in small strips across existing stands of perennial ryegrass and Chewings fescue significantly increased bermudagrass establishment. Preplant aerification and vertical mowing increased bermudagrass establishment, but slightly reduced turfgrass quality. Overall, bermudagrass establishment into existing stands of turfgrass was successful only where glyphosate was strip-treated over plots to eliminate competition or under circumstances where disease pressure reduced competition from the existing turfgrass. / Master of Science
7

Závod jako předmět právních vztahů (koupě závodu a pacht závodu) / Commercial establishment as an object of legal relationship (purchase of commercial establishment and usufructuary lease of commercial establishment)

Přibyl, Jan January 2015 (has links)
Commercial establishment as an object of legal relationship (purchase of commercial establishment and usufructuary lease of commercial establishment) The topic of this thesis is "Commercial establishment as an object of legal relationship (purchase of commercial establishment and usufructuary lease of commercial establishment)". From the title it is obvious that commercial establishment is an object of legal relationship but not a subject of legal relationship which is a considerable part of its understanding. With the acceptance of the Czech Civil Code a lot of changes came to this institute, including name change. This is the reason why it was necessary to conceive this matter complexly, from the basic term to specifics of particular legal relationships. The first part of this thesis is focussed on a basic term of commercial establishment and its circumscription in the Czech Civil Code, where it is understood as a set of asset and also as an agent for entrepreneurial activities. This part analyses particular kinds of commercial establishment and also branch of another parts of commercial establishment. The second part is dedicated to various examples of legal relationships where the commercial establishment might be the object. Particular legal relationships are concisely characterised. In this part there...
8

Micro-sítio como filtro para o estabelecimento de regenerantes arbóreos em áreas restauradas / Microsites as filters for tree species establishment under restoration plantings

Bertacchi, Maria Isabel Ferreira 20 December 2011 (has links)
As características da regeneração natural no sub-bosque de comunidades florestais em processo de restauração expressam os principais indicadores de sucesso dos projetos de restauração ecológica, sendo que a ausência ou a baixa qualidade de regeneração natural são os principais gargalos para a perpetuação de projetos inseridos em paisagens muito fragmentadas. No entanto, condições adversas de micro-sítio de regeneração sob plantios de restauração podem restringir a colonização do sub-bosque por espécies nativas, comprometendo a sua perpetuação no tempo. O objetivo desse estudo foi avaliar se, e como, as condições físico-químicas do micro-sítio de regeneração, no sub-bosque de áreas em processo de restauração com diferentes idades, podem limitar o estabelecimento de espécies arbóreas nativas, restringindo assim, a restauração da dinâmica florestal. O estudo foi desenvolvido em três áreas em processo de restauração com diferentes idades (10, 22 e 55 anos), implantadas via reflorestamentos de alta diversidade. Foi realizada a caracterização físico-química do micro-sitio de regeneração das áreas de estudo, avaliando-se o grau de compactação, porosidade, umidade, conteúdo de matéria orgânica e nutrientes e granulometria do solo, bem como a massa seca de serapilheira, e a cobertura do dossel. Em cada área de estudo, foram alocados 10 blocos experimentais, cada um constituído por 4 parcelas de 1 m x 1 m, onde foram semeadas nove espécies arbóreas nativas regionais. Nessas parcelas foram estabelecidos três tratamentos e um controle: A) semeadura na condição natural da área, sem qualquer alteração das características do micro-sítio de estabelecimento (serapilheira autóctone), B) semeadura sobre a serapilheira e o solo transplantados de floresta nativa (serapilheira alóctone), C) semeadura sobre bagaço de cana triturado e compostado e D) controle (sem semeadura). A coleta dos dados de emergência e mortalidade de plântulas foi feita por um período de 6 meses. Ocorreu um gradiente de aumento da cobertura do dossel, da porosidade, da umidade, do conteúdo de argila e matéria orgânica e uma diminuição da compactação do solo das áreas restauradas mais novas para as mais velhas. A emergência de plântulas não diferiu entre as áreas de estudo, porém, a sobrevivência de plântulas foi significativamente menor na restauração mais antiga, de 55 anos. Constatou-se uma correlação positiva entre a mortalidade de plântulas com o aumento da cobertura do dossel e com a quantidade de matéria orgânica no solo. A emergência e a sobrevivência de plântulas foram estatisticamente maiores no tratamento onde as sementes foram aplicadas sobre serapilheira autóctone. Assim, conclui-se que apesar das condições de micro-sítio de regeneração de florestas em restauração tornarem-se, com o tempo, mais semelhantes à de florestas naturais, tornam-se cada vez mais restritivas ao estabelecimento de plântulas. Além disso, o estabelecimento de plântulas é favorecido nas condições locais de substrato de florestas em processo de restauração florestal, sem limitação evidente para que a sucessão secundária avance. Conseqüentemente, a limitação de dispersão deve ter influência maior nessas condições para o avanço inicial da restauração do que a limitação de micro-sítios favoráveis de estabelecimento. / The characteristics of the natural regeneration of restoration plantings understory express the main indicators of success of ecological restoration projects, in which the absence of regeneration indicates a bottleneck for the perpetuation of forest communities inserted into highly fragmented landscapes. Nevertheless, adverse conditions of the micro-site of regeneration in restoration plantings may hamper the colonization of the understory by native species, which in turn collapse its perpetuation along the time. We sought to evaluate if, or how, the physical-chemical conditions of the micro-site of regeneration of restoration plantings with different ages can limit native tree species establishment and therefore, the dynamic of forest restoration. The study was developed in three areas under restoration with different ages (10, 22 and 55 years). The physical-chemical characterization of the micro-site of regeneration of the study areas was carried out by evaluating the soil compression level, porosity, humidity, organic matter and nutrients content and granulometry, as well as litter dry mass and canopy cover. In each area, we set 10 experimental blocks, each one consisting of four 1 m x 1 m plots, in which nine tree species were sown. In each plot we established three treatments: A) direct seeding in the natural condition of the area, without any alteration in the characteristics of the micro-site (indigenous leaf litter), B) direct seeding on the leaf litter and soil transplanted from a native forest (allochthonous leaf litter), C) direct seeding on grounded and composted sugarcane bagasse and D) control (no seeding). Seedling emergence and mortality were observed through six months. An increase on the canopy cover and soil porosity, humidity, clay and organic matter content were observed in the oldest areas, as well as a decrease in soil compression. Seedling emergence did not differ among the studied areas; however, seedling survival was significantly lower in the oldest reforestation, with 55 years. A positive correlation was observed between seedling mortality with the increase of canopy cover and soil organic matter content. Seedling emergence and survival were statistically higher in the treatment A (indigenous leaf litter). Thus, although the micro-site conditions for seedling establishment become even more similar to reference ecosystems as restoration planting evolve, it also becomes more restrictive. In addition, seedling establishment was favored in the conditions of local substrate of restoration plantings, without evidence of limitation for the progress of secondary succession. Consequently, dispersal limitation may play a higher influence in this condition for the advance of restoration process.
9

Micro-sítio como filtro para o estabelecimento de regenerantes arbóreos em áreas restauradas / Microsites as filters for tree species establishment under restoration plantings

Maria Isabel Ferreira Bertacchi 20 December 2011 (has links)
As características da regeneração natural no sub-bosque de comunidades florestais em processo de restauração expressam os principais indicadores de sucesso dos projetos de restauração ecológica, sendo que a ausência ou a baixa qualidade de regeneração natural são os principais gargalos para a perpetuação de projetos inseridos em paisagens muito fragmentadas. No entanto, condições adversas de micro-sítio de regeneração sob plantios de restauração podem restringir a colonização do sub-bosque por espécies nativas, comprometendo a sua perpetuação no tempo. O objetivo desse estudo foi avaliar se, e como, as condições físico-químicas do micro-sítio de regeneração, no sub-bosque de áreas em processo de restauração com diferentes idades, podem limitar o estabelecimento de espécies arbóreas nativas, restringindo assim, a restauração da dinâmica florestal. O estudo foi desenvolvido em três áreas em processo de restauração com diferentes idades (10, 22 e 55 anos), implantadas via reflorestamentos de alta diversidade. Foi realizada a caracterização físico-química do micro-sitio de regeneração das áreas de estudo, avaliando-se o grau de compactação, porosidade, umidade, conteúdo de matéria orgânica e nutrientes e granulometria do solo, bem como a massa seca de serapilheira, e a cobertura do dossel. Em cada área de estudo, foram alocados 10 blocos experimentais, cada um constituído por 4 parcelas de 1 m x 1 m, onde foram semeadas nove espécies arbóreas nativas regionais. Nessas parcelas foram estabelecidos três tratamentos e um controle: A) semeadura na condição natural da área, sem qualquer alteração das características do micro-sítio de estabelecimento (serapilheira autóctone), B) semeadura sobre a serapilheira e o solo transplantados de floresta nativa (serapilheira alóctone), C) semeadura sobre bagaço de cana triturado e compostado e D) controle (sem semeadura). A coleta dos dados de emergência e mortalidade de plântulas foi feita por um período de 6 meses. Ocorreu um gradiente de aumento da cobertura do dossel, da porosidade, da umidade, do conteúdo de argila e matéria orgânica e uma diminuição da compactação do solo das áreas restauradas mais novas para as mais velhas. A emergência de plântulas não diferiu entre as áreas de estudo, porém, a sobrevivência de plântulas foi significativamente menor na restauração mais antiga, de 55 anos. Constatou-se uma correlação positiva entre a mortalidade de plântulas com o aumento da cobertura do dossel e com a quantidade de matéria orgânica no solo. A emergência e a sobrevivência de plântulas foram estatisticamente maiores no tratamento onde as sementes foram aplicadas sobre serapilheira autóctone. Assim, conclui-se que apesar das condições de micro-sítio de regeneração de florestas em restauração tornarem-se, com o tempo, mais semelhantes à de florestas naturais, tornam-se cada vez mais restritivas ao estabelecimento de plântulas. Além disso, o estabelecimento de plântulas é favorecido nas condições locais de substrato de florestas em processo de restauração florestal, sem limitação evidente para que a sucessão secundária avance. Conseqüentemente, a limitação de dispersão deve ter influência maior nessas condições para o avanço inicial da restauração do que a limitação de micro-sítios favoráveis de estabelecimento. / The characteristics of the natural regeneration of restoration plantings understory express the main indicators of success of ecological restoration projects, in which the absence of regeneration indicates a bottleneck for the perpetuation of forest communities inserted into highly fragmented landscapes. Nevertheless, adverse conditions of the micro-site of regeneration in restoration plantings may hamper the colonization of the understory by native species, which in turn collapse its perpetuation along the time. We sought to evaluate if, or how, the physical-chemical conditions of the micro-site of regeneration of restoration plantings with different ages can limit native tree species establishment and therefore, the dynamic of forest restoration. The study was developed in three areas under restoration with different ages (10, 22 and 55 years). The physical-chemical characterization of the micro-site of regeneration of the study areas was carried out by evaluating the soil compression level, porosity, humidity, organic matter and nutrients content and granulometry, as well as litter dry mass and canopy cover. In each area, we set 10 experimental blocks, each one consisting of four 1 m x 1 m plots, in which nine tree species were sown. In each plot we established three treatments: A) direct seeding in the natural condition of the area, without any alteration in the characteristics of the micro-site (indigenous leaf litter), B) direct seeding on the leaf litter and soil transplanted from a native forest (allochthonous leaf litter), C) direct seeding on grounded and composted sugarcane bagasse and D) control (no seeding). Seedling emergence and mortality were observed through six months. An increase on the canopy cover and soil porosity, humidity, clay and organic matter content were observed in the oldest areas, as well as a decrease in soil compression. Seedling emergence did not differ among the studied areas; however, seedling survival was significantly lower in the oldest reforestation, with 55 years. A positive correlation was observed between seedling mortality with the increase of canopy cover and soil organic matter content. Seedling emergence and survival were statistically higher in the treatment A (indigenous leaf litter). Thus, although the micro-site conditions for seedling establishment become even more similar to reference ecosystems as restoration planting evolve, it also becomes more restrictive. In addition, seedling establishment was favored in the conditions of local substrate of restoration plantings, without evidence of limitation for the progress of secondary succession. Consequently, dispersal limitation may play a higher influence in this condition for the advance of restoration process.
10

Colonisation and succession along a South Wales trunk road : variation and change in relation to natural and human factors

Thomas, Hilary Susan Clarke January 1992 (has links)
No description available.

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