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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.
121

Efeito da densidade construída sobre o microclima urbano: construção de diferentes cenários possíveis e seus efeitos no microclima para a cidade de São Paulo, SP / Effect of built density on the urban microclimate: construction of different scenarios and their effects on the microclimate for the city of São Paulo, SP

Carolina dos Santos Gusson 26 May 2014 (has links)
O objeto desta pesquisa é a relação entre densidade construída e microclimas urbanos. O objetivo é quantificar o efeito da densidade construída sobre o microclima urbano, por meio da construção de diferentes cenários paramétricos, considerando os possíveis padrões de ocupação de quadra, com diferentes tipologias de edifícios: o bloco perimetral, o edifício lâmina e o edifício torre, para a cidade de São Paulo. O método é indutivo, por meio de levantamentos de campo de uso e ocupação do solo e de condições microclimáticas locais, em dois dos distritos mais densamente habitados do município de São Paulo, mas que apresentam diferentes densidades construídas: Brasilândia, com coeficiente de aproveitamento menor do que 1, e Bela Vista, com coeficiente de aproveitamento maior do que 3,5; e dedutivo, por meio de comparações entre os levantamentos de campo e as simulações computacionais com o modelo ENVI-met 4.0 (preview), que foram feitas para se calibrar o modelo entre dados medidos e simulados, visando à maior confiabilidade dos resultados. Na sequência, foram explorados cinco cenários paramétricos (lâminas com 3 orientações diferentes, torre e perímetro), com nove quadras cada, mantendo-se aproximadamente o mesmo coeficiente de aproveitamento (em torno de 3,7) e a mesma densidade populacional possível (em torno de 1500 hab/ha) em todos os casos estudados. As simulações paramétricas para três dias consecutivos mostraram que, dentre os cenários simulados, o cenário torre apresentou, de forma consistente, uma diferença de cerca de 0,6°C para menos na temperatura do ar, a 1,5m do chão, em relação ao cenário perímetro para a quadra central, no horário de maior temperatura do ar, às 15h, e cerca de 1,4°C a menos na temperatura do ar para o período noturno. Os demais cenários lâmina apresentaram resultados intermediários entre os dois anteriores. Isso mostra que, mantendo-se a mesma densidade construída, os arranjos apresentam comportamentos distintos. Dentre os casos estudados, o cenário torre foi o que apresentou as menores temperaturas do ar, nos períodos diurno e noturno, provavelmente devido ao sombreamento mutuo entre os edifícios, que contribui para o menor aquecimento das superfícies e, consequentemente, menor aquecimento do ar no entorno imediato. / The subject of this research is the relation between the built density and urban microclimates. The objective is to quantify the effect of built density on urban microclimates, through the construction of different parametric scenarios, considering the possible blocks occupation patterns, with different buildings typologies: the perimeter block, the blade building, and the tower building for the city of São Paulo. The method is inductive, through field data measurement of the land use and local microclimate conditions in two most densely populated districts in São Paulo city, but with different built densities: Brasilândia with a plot ratio lower than 1, and Bela Vista, with a plot ratio greater than 3.5; and deductive, by comparisons between field measurements and computer simulations with the ENVI-met 4.0 (preview) model, which were used to calibrate the model between measured data and simulated data, aiming at higher reliability of the results. After that, five parametric scenarios (blades with 3 different orientations, tower, and perimeter) were explored, each with nine blocks, while maintaining approximately the same plot ratio (around 3.7) and the same population density (around 1500 inhabitants/ha) in all cases studied. Parametric simulations for three consecutive days showed that, among the simulated scenarios, the tower scenario presented, consistently, a difference of about 0.6 °C lower for air temperature, at 1.5 m from the floor, compared the perimeter scenario for the center court at the time, 15h, of highest air temperature, and about 1.4 °C less in the nighttime air temperature. The other blade scenarios showed intermediate results between the previous two, showing that, keeping the same built density, the scenarios have different behaviors. Among the cases studied, the tower scenario showed the lowest air temperatures during day and night periods, probably due to mutual shading among buildings, which contributes to less heating of the surfaces and thus less heating of the air in the immediate surroundings.
122

Predação de plantas jovens de Euterpe edulis e invasão de lavouras de milho por Sapajus nigritus em remanescentes de floresta atlântica no sul do Brasil / Density and population abundance of Sapajus nigritus in remnants of Atlantic Forest immersed in agricultural matrix in southern Brazil

Lacerda, Wagner Rafael 18 July 2013 (has links)
Made available in DSpace on 2017-07-10T14:38:18Z (GMT). No. of bitstreams: 1 LACERDA.pdf: 2108583 bytes, checksum: abf7b4231c66cc12a04083c0090487bb (MD5) Previous issue date: 2013-07-18 / The almost complete replacement of the native vegetation of the Atlantic Forest by agriculture and livestock generated an altered matrix in which are embedded fragments of different sizes and historical use and degradation. In this study, the population density of Sapajus nigritus was estimated in two forest fragments surrounded by agricultural crops in southern Brazil. We use the method of linear transect between September 2011 and January 2013, covering 344.08 km in area and 216 km in another. We recorded 119 sightings and 35, respectively. In the first area the population density of Sapajus nigritus was 92.15 individuals / km2, and 32.10 individuals / km2 for the second area. While the lowest value is within the limits found for the species throughout its geographical distribution, the value of 92.15 individuals / km2 is among the highest ever recorded. In addition to offering food crops by anthropogenic factors such as low hunting pressure and predation, as well as composition and forest structure may be related to the densities found / A quase completa substituição da vegetação nativa da Floresta Atlântica pela agricultura e pecuária gerou uma matriz alterada onde estão inseridos fragmentos de diferentes tamanhos e históricos de uso e degradação. Neste estudo, a densidade populacional de Sapajus nigritus foi estimada em dois remanescentes florestais cercados por cultivos agrícolas no sul do Brasil. Nós utilizamos o método de transecções lineares entre setembro de 2011 e janeiro de 2013, percorrendo 344,08 km em uma área e 216 km em outra. Foram registrados 119 e 35 avistamentos, respectivamente. Na primeira área a densidade populacional de Sapajus nigritus foi de 92,15 indivíduos/km2, e 32,10 indivíduos/km2 para a segunda área. Enquanto o valor mais baixo está dentro dos limites encontrados para a espécie ao longo de sua distribuição geográfica, o valor de 92,15 indivíduos/km2 está entre os mais elevados já registrados. Além da oferta de alimento de origem antrópica pelos cultivos, fatores como baixa pressão de caça e predação, além da composição e estrutura da floresta podem estar relacionados às densidades encontradas
123

Feeding behaviour on the European hedgehog (Erinaceus europaeus L.) in a New Zealand pasture

Campbell, Patricia Ann January 1973 (has links)
The feeding behaviour of the European hedgehog (Erinaceus europaeus L.) has been investigated in a pastoral environment. Sampling methods that caused the minimum interference to the natural population were used. The relative importance of the various prey species in the diet were analysed by occurrence, relative volume and direct counting techniques. Problems often associated with the use of direct counting were successfully overcome. It was established that the main animal food items in the hedgehog diet were earwigs, lepidopteran larvae, beetles, harvestmen, dung flies, slugs, and earthworms. Small quantities of a large number of other species were also consumed. Several variations in the diet were found to be related to changes in the availability of food species. Although hedgehogs are capable of consuming large numbers of grass grub beetles (Costelytra zealandica) during the flight season it is concluded that they are unlikely to provide any effective measure of biological control of this pasture pest. Hedeghog diet was not influenced significantly by the sex of the animal, or by pasture irrigation. It was demonstrated that the feeding rhythm of captive animals, fed under laboratory conditions, was similar to that observed in the field. Observation showed that hedgehogs were active for an average of eight hours per night, with a period of maximum activity between 9 p.m. and 11 p.m. Animals tended to follow relatively fixed routes on successive nights. Excluding nestlings, the population density in an irrigated clover-ryegrass pasture was found to vary from four (winter) to eight (summer) animals per hectare. The average minimum feeding range of these animals was 2.4 hectares, although their feeding ranges overlapped considerably.
124

Population change in Adelaide's peri-urban region : patterns, causes and implications

Ford, Tania. January 1998 (has links) (PDF)
Errata slip inserted. Bibliography: leaves 282-298. Aims to contribute to a clearer understanding of the nature of current patterns of population change in the peri-urban region; conceptualized as a set of overlapping zones of net growth representing the product of four demographic processes (suburbanisation, counterurbanisation, population retention, centripetal migration). Considers three key aspects of peri-urban growth dynamics in the context of Adelaide's peri-urban region.
125

Determining optimum plant population densities for three annual green manure crops under weedy and weed-free conditions

Lawley, Yvonne 22 December 2004
Green manure crops are critical to maintaining soil fertility in organic cropping systems. However, little research has been conducted to address their contribution to weed control. Indianhead black lentil (Lens culinaris Medikus), AC Green Fix chickling vetch (Lathyrus sativus L.), and Trapper field pea (Pisum sativum L.) are legumes developed for use as annual green manure crops in the Northern Great Plains. Currently, no plant population density recommendations exist for these three species when grown as green manure crops under weedy conditions. The objective of this research was to determine the yield-density response of these three species under weedy and weedy-free conditions and to develop plant population density recommendations for use as annual green manure crops. Each species was grown at five plant population densities (10, 24, 64, 160, and 400 plants m-2) with weedy and weed-free treatments. Wild oat (Avena fatua L.) and wild mustard (Brassica kaber (D.C.) L.C. Wheeler) were planted in weedy treatments to supplement the natural weed community. Biomass samples and soil moisture measurements were taken at early bud and full bloom to simulate when these crops would be terminated. Biomass samples from the early bud stage were analysed for total nitrogen content. Green manure biomass production for all species was lower under weedy conditions. Weed biomass in weedy treatments decreased with increasing green manure plant population density for all species. Trapper field pea was the most competitive crop while Indianhead black lentil was the least competitive. Although total plot biomass differed among species and green manure crop density, changes in soil moisture levels were not greatly affected. No significant difference in total nitrogen concentration was found among green manure species. Differences in total nitrogen accumulation occurred because of differences in biomass production. Marginal cost analysis based on green manure seed costs and their nitrogen contribution to the value of subsequent wheat crop yield were used to determine optimum plant population densities. Under weedy conditions field pea and black lentil should be planted at densities of 49-78 and 223-300 plants m-2, respectively. Under weed-free conditions plant population densities for field pea and black lentil could be reduced to 45-60 and 184-223 plants m-2, respectively. No profitable plant population density was determined for chickling vetch when assuming a lower nitrogen contribution under both weedy and weed-free conditions. However, when assuming a higher nitrogen contribution, a profitable plant population density for chickling vetch of 24 plants m-2 was determined under weedy conditions and 32 plants m-2 under weed-free conditions.
126

Mathematical Models of <i>Zea mays</i>: Grain Yield and Aboveground Biomass Applied to Ear Flex and within Row Spacing Variability

Ballard, Todd Curtis 01 December 2008 (has links)
Field studies were conducted during the summers of 2007 and 2008 at the Agricultural Research and Education Complex, Western Kentucky University, Warren County, KY and commercial production fields in Caldwell County, KY, Warrick County IN, and Vanderburgh County, IN. The goals of these studies were to further validate the Duncan grain yield model, the Russell aboveground biomass model, and to study the effect of inconsistent spacing within rows on Zea mays L. yield. Plant spacing other than uniform decreases grain yield and profitability. The population experiments conducted at the Warren County location were a randomized complete block design with three planting densities, three varieties (c.v. DeKalb DKC6547, DeKalb DKC6346, DeKalb DKC6478) in 2007 and (DeKalb DKC6478, DeKalb DKC6342, and DeKalb DKC6544) in 2008, and three replications. Seeds were planted in rows 76 cm apart and 9.1 m long with four rows per plot in a no-till system on a Crider Silt Loam with pH of 6.8 and 1.5% organic matter. The effect of variable within row spacing was evaluated in commercial production fields by randomly selecting five adjacent rows of 5.3 meters in length at each location. Grain yield for each row was then curve fitted both linearly and exponentially. Minimizing interspecies competition was essential to evaluating the effects of competition within Zea mays L. A burn-down application of 2,4-D and glyphosate was used prior to planting. The most common weeds in the plots were Sorghum halepense L. (johnsongrass), Trifolium repens L. (white clover), and Taraxacum officinale L. (common dandelion) . Glyphosate was reapplied throughout the growing season due to reemergence of S. halepense and Ipomoea hederacea Jacq. (ivyleaf morningglory). The weight of each ear was recorded and one row from each plot was randomly selected to shell. The moisture content was measured from a subsample twice each row using an electrical conductivity moisture meter. The mean of the two moisture readings was used as the moisture content from the plot. Cob weights from shelled ears were recorded to determine the grain/cob mass ratio. This ratio was used to project the grain weight for the remaining harvested rows. Duncan’s grain yield model and Russell’s biomass model were curve fitted to the data for areas of 0.00040 hectares at the p < 0.05 significance level or greater in all population density plots. Individual plant grain masses were curve fitted to Duncan’s model with p < 0.05 significance in 3 out of 15 plots. Grain mass was negatively correlated (R < 0) with standard deviation of within row spacing in 14 of 15 plots. A linear fit to this trend was significant in only 2 of 15 plots. The Duncan yield curve and the Russell aboveground biomass model fit all 6 genotype by environment interactions for 2007 and 2008 to the α = 0.05 level of confidence when evaluated over a 5.3 meter length on 76.2 cm wide rows. Individual plants fit linearly at α = 0.05 in 9 out of 15 plots. Individual plants fit the Duncan yield curve at α = 0.05 in 4 out of 15 plots. Standard deviation of within row spacing fit grain yield loss significantly at &#; = 0.05 in two of 15 plots. The individual plant spacing and local population density collectively fit nine plots significantly at α = 0.05 or better.
127

Determining optimum plant population densities for three annual green manure crops under weedy and weed-free conditions

Lawley, Yvonne 22 December 2004 (has links)
Green manure crops are critical to maintaining soil fertility in organic cropping systems. However, little research has been conducted to address their contribution to weed control. Indianhead black lentil (Lens culinaris Medikus), AC Green Fix chickling vetch (Lathyrus sativus L.), and Trapper field pea (Pisum sativum L.) are legumes developed for use as annual green manure crops in the Northern Great Plains. Currently, no plant population density recommendations exist for these three species when grown as green manure crops under weedy conditions. The objective of this research was to determine the yield-density response of these three species under weedy and weedy-free conditions and to develop plant population density recommendations for use as annual green manure crops. Each species was grown at five plant population densities (10, 24, 64, 160, and 400 plants m-2) with weedy and weed-free treatments. Wild oat (Avena fatua L.) and wild mustard (Brassica kaber (D.C.) L.C. Wheeler) were planted in weedy treatments to supplement the natural weed community. Biomass samples and soil moisture measurements were taken at early bud and full bloom to simulate when these crops would be terminated. Biomass samples from the early bud stage were analysed for total nitrogen content. Green manure biomass production for all species was lower under weedy conditions. Weed biomass in weedy treatments decreased with increasing green manure plant population density for all species. Trapper field pea was the most competitive crop while Indianhead black lentil was the least competitive. Although total plot biomass differed among species and green manure crop density, changes in soil moisture levels were not greatly affected. No significant difference in total nitrogen concentration was found among green manure species. Differences in total nitrogen accumulation occurred because of differences in biomass production. Marginal cost analysis based on green manure seed costs and their nitrogen contribution to the value of subsequent wheat crop yield were used to determine optimum plant population densities. Under weedy conditions field pea and black lentil should be planted at densities of 49-78 and 223-300 plants m-2, respectively. Under weed-free conditions plant population densities for field pea and black lentil could be reduced to 45-60 and 184-223 plants m-2, respectively. No profitable plant population density was determined for chickling vetch when assuming a lower nitrogen contribution under both weedy and weed-free conditions. However, when assuming a higher nitrogen contribution, a profitable plant population density for chickling vetch of 24 plants m-2 was determined under weedy conditions and 32 plants m-2 under weed-free conditions.
128

Investigating the applicability of new urbanist principles for urban renewal in a high-density context

Fermin, Ephraim Kimwell. January 1998 (has links)
published_or_final_version / Urban Design / Master / Master of Urban Design
129

Aggregation in the Schelling model and inverted biomass pyramids in ecosystems

Singh, Abhinav 25 June 2009 (has links)
Thomas Schelling proposed a simple spatial model to illustrate how, even with relatively mild assumptions on each individual's nearest neighbor preferences, an integrated city would likely unravel to a segregated city, even if all individuals prefer integration. Many authors assumed that the segregation which Schelling observed in simulations on very small cities persists for larger, realistic size cities. We describe how different measures can be used to quantify the segregation and unlock its dependence on city size, disparate neighbor comfortability threshold, and population density. We develop highly efficient simulation algorithms and quantify aggregation in large cities based on thousands of trials. In particular, we show that for the values of disparate neighbor comfortability threshold used by Schelling, the striking global aggregation Schelling observed is strictly a small city phenomenon. Along the way we prove that in the Schelling model, in the process of evolution, the total perimeter of the interface between the different agents always decreases, which provides a useful analytical tool to study the evolution. At the isolated reef Kingman, it was recently discovered that apex predators constitute 85% of the total fish biomass. This is in sharp contrast to most reefs, where the prey biomass substantially dominates the total fish biomass. The recent study at the two pristine reefs, Kingman and Palmyra also indicates that the predator:prey fish biomass ratio is an increasing function of reef cover. Based on these field observations, we model the fish biomass structure at a pristine coral reef. We introduce a new refuge based mechanism for predator-prey interaction with an explicit dependence on refuge size. Our refuge based model does not assume mass action interaction between predators and prey and may provide a new mechanism in ecology to produce inverted biomass pyramids. Our model yields both the inverted biomass pyramid and the increasing dependence of the predator:prey biomass ratio on reef cover. We add various forms of fishing to our model, and show that sufficiently high fishing pressure with quite general types of fishing transforms the inverted biomass pyramid to be bottom heavy.
130

A study of home ranges, movement and activity patterns of Great Spotted Kiwi (Ateryx haastii) in the Hurunui Region, South Island, New Zealand

Keye, Constanze January 2008 (has links)
All kiwi species (Apteryx spp.) have suffered serious decline since human arrival and are nowa-days threatened on the New Zealand mainland. One of the most elusive, and as a result least known among the different kiwi species, is the great spotted kiwi (Apteryx haastii). Hence, little is known about the current status of the remaining great spotted kiwi populations or their popu-lation dynamics. Three main ‘natural’ populations are found in Northwest Nelson, the Paparoa Range and in the Arthur’s Pass Hurunui district. In 2007, the Department of Conservation started a great spotted kiwi population dynamics study in the North Branch of the Hurunui, the area where this research project was conducted. Kiwi workers of the Department of Conserva-tion (Waimakariri area office) captured and VHF radio-tagged 11 kiwi between March and July 2007 in the North Branch and started to collect radio tracking and activity data. To improve this existing data set, 10 of the 11 birds were intensely radio tracked using triangulation and homing techniques during December 2007 to April 2008 for this Master’s research project. Estimated home-range sizes for great spotted kiwi in the North Branch varied between 19.59 ha and 35.41 ha, with a calculated mean of 29.3 ha for adult birds. The kiwi population in a defined research area of 60 km² in the Hurunui North Branch was estimated to be around 290 birds. The density for the whole area monitored by the Department of Conservation in the North Branch was esti-mated to be 2.25 pairs per km² plus subadults or in other terms 4.83 birds per km². These density estimates are much higher than results of earlier studies in the Arthurs Pass/Hurunui district. Movement plots of three bonded pairs showed that partners stayed in territories they shared. Nevertheless pairs shared only in 5% of days (n=38) shelters but regularly met during night and kept in contact via calls especially prior to meetings. Nightly travel distances varied between 488-1657 m. Furthermore, the most frequent travel distances covered per hour ranged between 50-150 m. The results of this study provide information for other kiwi researchers and raise ad-ditional questions for other projects regarding great spotted kiwi biology, behaviour and dynam-ics still need to be answered (e.g. habitat requirements). Finally, the results of this study alone are poor indicators of current population health, but they do provide a scientific baseline for any subsequent population monitoring for the great spotted kiwi population status and health in the North Branch area. If future monitoring shows that the great spotted kiwi population is at risk, suitable management actions can be applied and their success can be correctly evaluated.

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