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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.
21

Characteristics of Ungulate Behavior and Mortality Associated with Wire Fences

Harrington, Justin L. 01 May 2005 (has links)
I studied the characteristics of fence mortality in pronghorn (Antilocapra americana), mule deer (Odocoileus hemionus), and elk (Cervus elaphus) along roads in Colorado and Utah from June 2004 to June 2005. I defined a direct-fence mortality as a carcass caught directly in a fence and an indirect-fence mortality as a carcass on the ground within 10 m of a fence. I estimated an average annual direct mortality occurrence of 0.25 mortalities/km (0.078 mule deer mortalities/km, 0.113 pronghorn mortalities/km, and 0.061 elk mortalities/km). The highest fence-mortality rates for ungulates occurred during August, which coincided with weaning of fawns on my study area. Mule deer and pronghorn both jumped fences in >81% of observed crossings and did not differ in their crossing methods (P = 0.37). Getting caught between the top 2 wires was the leading cause of death for fence mortalities. Mule deer suffered higher fence-mortality rates than elk or pronghorn because they crossed fences more frequently and fed in the right-of-way of the road more often (P < 0.001). Juveniles were 8 times more likely to die in fences than adults. Woven-wire fence types were more lethal to ungulates (especially juveniles) than other fence types (P < 0.001). Woven wire with a single strand of barbed wire above it was significantly more lethal to ungulates than woven wire with 2 strands of barbed wire above it, or 4-strand barbed-wire fence (P < 0.001). There was a direct relationship between the frequency of fence-mortalities and ungulate abundance (P < 0.001 ). Traffic volumes had an inverse relationship with fence mortality frequencies (P < 0.001) and ungulate densities along the right-of-way (P < 0.001). Indirect mortality (i.e., carcasses within 10 m of fences) composed 66% of fence-related mortality, whereas direct-fence mortality (i.e., carcasses in fences) composed a mere 33%. Additionally, indirect-fence mortality was found to be greater along woven-wire fences, when compared to barbed-wire fence types (P = 0.003).
22

Mötet mellan centralt och lokalt : Studier i uppländska byordningar / The meeting ofcentral and local authority : Studies on village by-laws in Uppland

Ehn, Wolter January 1991 (has links)
The Swedish village by-laws are a collection of rules for coexistence in a village which evolved during the 18th and 19th centuries. The dissertation takes its starting point in an edition of Byordningar från Mälarlänen (Village By-Laws in the Lake Mälar districts) containing about 400 by-laws from the central part of Sweden, and is a limited review of that edition at the same time as it gives a systematic survey of certain aspects specified in the by-laws. These aspects were added as the result of an official proposal in 1742 containing a model on how a by-law should be constructed. The question is asked whether the directives of the Government were formulated when they reached the local level, or whether they were redesigned and adapted to suit the local situation. The village by-laws in the Mälar counties differ in form and in content depending upon the official proposal on by-laws from 1742. The village by-laws were originally discussed in connection with the changes in agriculture, and thus concerned such sectors as farming methods, fencing, grazing, the right to certain proportions of the village's resources. The local conditions in the village are reflected in, for example, the rules on the length of the grass for grazing. There were different kinds of such by-laws, e.g., by-laws for individual villages and by-laws for parishes (approved at a parish meeting). The initiative of the Government in requiring village by-laws gave different results in different counties. Large parts of Uppsala county are without forest land. The fences and the system of enclosing fields are therefore of particular interest in a discussion on the village by-laws. I have demonstrated that their origin and acceptance in Swedish villages and parishes can be placed in political, chronological, social and functional contexts. / <p>Diss. Uppsala : Univ.</p>
23

Seasonal Distribution of Sage-Grouse in Hamlin Valley, Utah and the Effect of Fences on Grouse and Avian Predators

McPherron, Heather Hedden 01 December 2017 (has links)
Greater sage-grouse (Centrocercus urophasianus; hereafter sage-grouse) numbers have declined throughout the western US and are considered a species of concern in most of the eleven states that are within their range. Sage-grouse habitats have been reduced by approximately 44% since European settlement of the Western United States began (Miller et al. 2011). Loss of habitat has contributed to an average decline of sage-grouse populations by 33% across the range (Connelly and Braun 1997). To expand our knowledge of this species, I monitored 16 radio-collared sage-grouse captured from four leks in Hamlin Valley, Utah, USA in 2011 and 2012 to determine habitat use. The Hamlin Valley population was primarily one-stage migratory but non-migratory behaviors were also observed. Birds from at least one of the leks used seasonal habitats in neighboring Nevada. Sage-grouse evolved in habitats where infrastructure (e.g. vertical structures) was not common. Introduction of infrastructure, such as fences in their habitat, can cause direct mortality via collision but may also indirectly influence productivity by increasing artificial perches for avian predators (e.g. golden eagles (Aquila chrysaetos) , red-tailed hawks (Buteo jamaicensis), and common ravens (Corvus corax). This research focused on collision rates and increased potential for avian predation on two small populations on the southern portion of the range of current occupied sage-grouse habitat in southwestern vi Utah. During 2011-2012, over 450 km of fences were surveyed for signs of collision and use by avian predators during all seasons (breeding, fall migration, and winter). No sage-grouse collisions were observed suggesting that management for sage-grouse in small populations may be better focused on improving habitat and reducing other causes of mortality which may be more prevalent. Fence post width (i.e. the perching surface) was the best predictor of use as perch by avian predators. Additionally, areas farther from other natural perches, with a low density of surrounding vegetation, and fences constructed along defined habitat edges were used by avian predators more frequently. Results of this study suggest that managers should construct fences with small widths to deter avian predators and care should be taken to maintain contiguous vegetation on either side of the posts while maintaining low shrub density.
24

Simulated Shrub Encroachment Impacts Function of Arctic Spider Communities

Legault, Geoffrey 14 December 2011 (has links)
The projected increase of shrubs across the Arctic is expected to alter patterns of snow cover, which may affect the phenology and survival of arthropods such as spiders. In this study, we simulated shrub encroachment on a series of tundra plots and examined the effects on the spider assemblages during the following growing season. Our simulated shrub treatment did not affect the abundance or composition of spider communities over the season; however, adults from the dominant genus Pardosa (Lycosidae) had significantly higher body mass on treatment plots. This difference in mass was observed following snow melt and persisted until halfway through the growing season. Given the importance of spiders as arthropod predators and as food sources for breeding birds, such a change in summer body mass could represent a shift in spiders’ functional contributions to Arctic ecosystems.
25

Simulated Shrub Encroachment Impacts Function of Arctic Spider Communities

Legault, Geoffrey 14 December 2011 (has links)
The projected increase of shrubs across the Arctic is expected to alter patterns of snow cover, which may affect the phenology and survival of arthropods such as spiders. In this study, we simulated shrub encroachment on a series of tundra plots and examined the effects on the spider assemblages during the following growing season. Our simulated shrub treatment did not affect the abundance or composition of spider communities over the season; however, adults from the dominant genus Pardosa (Lycosidae) had significantly higher body mass on treatment plots. This difference in mass was observed following snow melt and persisted until halfway through the growing season. Given the importance of spiders as arthropod predators and as food sources for breeding birds, such a change in summer body mass could represent a shift in spiders’ functional contributions to Arctic ecosystems.
26

Šiaulių miesto individualių sodybų tvorų įvairovė / Diversity of fences of private homesteads in Šiauliai city

Kėželienė, Odeta 02 August 2011 (has links)
Tvora - bet kokia užtvara apie kiemą, sodybą, daržą ar kitokį žemės sklypą (Lietuvių kalbos žodynas, 2008). Darbo objektas – Šiaulių miesto Medelyno, Ginkūnų ir Vijolių mikrorajonų individualių sodybų tvoros. Darbo tikslas – nustatyti tvorų funkcijas, formas ir konstrukcijas tirtuose individualiose sodybose Šiaulių miesto mikrorajonuose. Darbo uždaviniai – 1. Nustatyti tvorų funkcijas, būdingas tiruose Vijolių, Medelyno Ginkūnų individualių sodybų mikrorajonuose, remiantis tvorų ažūriškumu, aukščiu, derėjimu prie aplinkos ir būkle. 2. Nustatyti iš kokių medžiagų yra pagamintos tvoros, kurios išsiskiria savo formomis. 3.Apibūdinti tvorų konstrukcijas Vijolių, Medelyno, Ginkūnų mikrorajonų individualiose sodybose. 4. Apibūdinti 10 išskirtinių, originalių individualių sodybų tvorų. Darbo metodai – baigiamojo bakalauro darbo tyrimas buvo atliekamas Šiaulių miesto Medelyno, Ginkūnų, Vijolių individualių sodybų mikrorajonuose. Buvo įvertintos 150 individualių sodybų tvoros. Vertintos individualių sodybų tvoros fiksuotos nuotraukose, vizualiai vertintas tvorų ažūriškumas, aukštis, derėjimas prie aplinkos, medžiagiškumas, būklė, apibūdintos konstrukcijos bei medžiagos, iš kurių tvertos tvoros. Duomenys vedami į pagrindinę tvorų vertinimo lentelę. Analizuojant duomenis ir remiantis tvorų ažūriškumu, aukščiu, derėjimu prie aplinkos, medžiagiškumu ir būkle, tiriamos tvorų funkcijos, formos ir konstrukcijos Šiaulių miesto individualiose sodybose. Tyrimo metu nustatyta, kad individualių... [toliau žr. visą tekstą] / Fence – any barrier enclosing a yard, homestead, garden or any other plot of land. Subject of the paper – fences of private homesteads in Medelynas, Ginkūnai and Vijoliai neighborhoods of Šiauliai city. Aim of the paper – to determine functions, forms and constructions of fences in neighborhoods of Šiauliai city under research. Objectives of the paper – 1. To determine characteristic functions of fences in private homesteads in Medelynas, Ginkūnai and Vijoliai neighborhoods of Šiauliai city referring to openwork, height, consistency to environment and condition thereof. 2. To determine the material composition of the fences distinguishing themselves by forms thereof. 3. To describe constructions of the fences in private homesteads of Vijoliai, Medelynas, Ginkūnai neighborhoods. 4. To describe 10 exclusive extraordinary fences of private homesteads. Methods of the paper – research of the final bachelor’s degree thesis was conducted in Medelynas, Ginkūnai and Vijoliai neighborhoods of Šiauliai city. 150 fences of private homesteads were assessed. Pictures depicting fences of private homesteads were assessed, openwork, height, consistency to environment, materiality and condition of the fences were assessed on the visual basis, constructions and materials used for fencing were described. The data were entered into the main table of fence assessment. Functions, forms and constructions of fences in private homesteads of Šiauliai city were examined by the analysis of data and on... [to full text]
27

Concrete fence posts : statues in the fields

McDonald, Erin January 2001 (has links)
Historic concrete fence posts were created in the early twentieth century. This study examined how they were constructed and who constructed them. A survey of Randolph county, Indiana was conducted in order to determine the possible construction methods. Literature sources indicate that farmers were encouraged to construct concrete posts on their own. The survey also points to the idea that historic concrete fence posts were created by the farmers who used them. While commercially manufactured posts exist in Randolph county, they are from a later date, and thus not the focus of this study. Interviews with members off the farming community also indicate that most farmers built their own concrete fence posts, from molds they also made. While many businesses and colleges promoted the use and construction of concrete fence posts, they were individually made to serve farmers' immediate and long term fencing needs. / Department of Architecture
28

Avaliação dos efeitos de telas porosas sobre a aerodinâmica de pilhas de carvão / The effects of porous fences on the aerodynamics of coal piles

Malcum, Karin Ceroni January 2006 (has links)
O manuseio de matéria-prima bruta utilizada na indústria pode gerar emissões durante o seu transporte, armazenamento e eventual mistura. A atuação dos ventos em pátios abertos de armazenamento de carvão que existem em termelétricas, siderúrgicas e zonas de mineração pode acarretar no transporte e dispersão de partículas de carvão a grandes distâncias e a alturas consideráveis. É desejável reduzir a emissão do poluente sem interferir na atividade operacional destes pátios de carvão, de forma a se obter ganhos ambientais e econômicos. Os efeitos da utilização de telas de proteção para reduzir o transporte eólico de partículas de carvão foram estudados através de ensaios em túnel de vento, medindo-se as distribuições das pressões médias e flutuantes sobre a superfície de um modelo reduzido, em escala 1/125, de uma pilha representativa de um pátio real de estocagem de carvão.Distintas porosidades de tela (68%, 53%, 37% e 0%), em três distintas configurações, dois afastamentos e a duas diferentes alturas foram testadas. Além das medidas de pressões, o campo de velocidades sobre a superfície e entorno das pilhas foi obtido através de medições com sistema de anemometria de fio quente. Percebe-se claramente que as velocidades médias do vento são mais altas próximo ao topo da pilha, e que a presença das telas causa uma redução destas velocidades nas regiões mais críticas. As telas com porosidades intermediárias mostraram-se mais eficazes em minorar os efeitos nocivos provocados pela combinação das sucções na superfície com as velocidades tangenciais de arrasto. Verificou-se que a redução da porosidade implica em uma redução na velocidade do vento atuante na pilha. Quando posicionada a barlavento, a tela com porosidade 0% (placa) causou um aumento da zona de recirculação atrás da mesma, aumentando, portanto, as sucções sobre a superfície da pilha. Entretanto, quando posicionada a sotavento, a placa sólida implicou em reduções significativas das pressões médias sobre a pilha. De uma forma geral, as telas com porosidades variando de 53% a 68% foram mais eficazes em reduzir as flutuações de pressão na face a barlavento da pilha, sem aumentar significativamente as pressões médias. Entretanto, as telas com porosidade em torno de 37% foram as mais eficientes em reduzir os picos de pressão que se desenvolvem a partir de incidências oblíquas do vento. / The effects of using wind fences to reduce wind-blown coal dust were studied through wind tunnel tests. The mean and fluctuating pressure distributions over the surface of reduced coal pile models were measured. The tests were performed at a 1/125 scaled model of a typical coal pile. Different fence porosities (68%, 53%, 37%, 0%) as well as different fence positions and heights were tested. Further to the pressure measurements, the field velocities over the surface and surroundings of the piles were obtained through hot-wire anemometry measurements. The fence with no porosity (0%) caused and increase in the re-circulating zone behind the fence, therefore increasing the negative pressures over the pile surface, being soon disregarded. The fences with porosities ranging from 53% to 68% were most effective in reducing the pressure fluctuations on the windward face of the pile, without increasing significantly the mean pressures over it. These pressures are closely related to the dust emissions from the surface, directly affecting the surrounding environment. Although most effective for reducing pressure fluctuations, the best combined effect together with the drag surface velocities were found for the fences with intermediate porosities. The 37% porosity fence was the most effective in reducing the oblique wind induced peak pressures.
29

Avaliação dos efeitos de telas porosas sobre a aerodinâmica de pilhas de carvão / The effects of porous fences on the aerodynamics of coal piles

Malcum, Karin Ceroni January 2006 (has links)
O manuseio de matéria-prima bruta utilizada na indústria pode gerar emissões durante o seu transporte, armazenamento e eventual mistura. A atuação dos ventos em pátios abertos de armazenamento de carvão que existem em termelétricas, siderúrgicas e zonas de mineração pode acarretar no transporte e dispersão de partículas de carvão a grandes distâncias e a alturas consideráveis. É desejável reduzir a emissão do poluente sem interferir na atividade operacional destes pátios de carvão, de forma a se obter ganhos ambientais e econômicos. Os efeitos da utilização de telas de proteção para reduzir o transporte eólico de partículas de carvão foram estudados através de ensaios em túnel de vento, medindo-se as distribuições das pressões médias e flutuantes sobre a superfície de um modelo reduzido, em escala 1/125, de uma pilha representativa de um pátio real de estocagem de carvão.Distintas porosidades de tela (68%, 53%, 37% e 0%), em três distintas configurações, dois afastamentos e a duas diferentes alturas foram testadas. Além das medidas de pressões, o campo de velocidades sobre a superfície e entorno das pilhas foi obtido através de medições com sistema de anemometria de fio quente. Percebe-se claramente que as velocidades médias do vento são mais altas próximo ao topo da pilha, e que a presença das telas causa uma redução destas velocidades nas regiões mais críticas. As telas com porosidades intermediárias mostraram-se mais eficazes em minorar os efeitos nocivos provocados pela combinação das sucções na superfície com as velocidades tangenciais de arrasto. Verificou-se que a redução da porosidade implica em uma redução na velocidade do vento atuante na pilha. Quando posicionada a barlavento, a tela com porosidade 0% (placa) causou um aumento da zona de recirculação atrás da mesma, aumentando, portanto, as sucções sobre a superfície da pilha. Entretanto, quando posicionada a sotavento, a placa sólida implicou em reduções significativas das pressões médias sobre a pilha. De uma forma geral, as telas com porosidades variando de 53% a 68% foram mais eficazes em reduzir as flutuações de pressão na face a barlavento da pilha, sem aumentar significativamente as pressões médias. Entretanto, as telas com porosidade em torno de 37% foram as mais eficientes em reduzir os picos de pressão que se desenvolvem a partir de incidências oblíquas do vento. / The effects of using wind fences to reduce wind-blown coal dust were studied through wind tunnel tests. The mean and fluctuating pressure distributions over the surface of reduced coal pile models were measured. The tests were performed at a 1/125 scaled model of a typical coal pile. Different fence porosities (68%, 53%, 37%, 0%) as well as different fence positions and heights were tested. Further to the pressure measurements, the field velocities over the surface and surroundings of the piles were obtained through hot-wire anemometry measurements. The fence with no porosity (0%) caused and increase in the re-circulating zone behind the fence, therefore increasing the negative pressures over the pile surface, being soon disregarded. The fences with porosities ranging from 53% to 68% were most effective in reducing the pressure fluctuations on the windward face of the pile, without increasing significantly the mean pressures over it. These pressures are closely related to the dust emissions from the surface, directly affecting the surrounding environment. Although most effective for reducing pressure fluctuations, the best combined effect together with the drag surface velocities were found for the fences with intermediate porosities. The 37% porosity fence was the most effective in reducing the oblique wind induced peak pressures.
30

Avaliação dos efeitos de telas porosas sobre a aerodinâmica de pilhas de carvão / The effects of porous fences on the aerodynamics of coal piles

Malcum, Karin Ceroni January 2006 (has links)
O manuseio de matéria-prima bruta utilizada na indústria pode gerar emissões durante o seu transporte, armazenamento e eventual mistura. A atuação dos ventos em pátios abertos de armazenamento de carvão que existem em termelétricas, siderúrgicas e zonas de mineração pode acarretar no transporte e dispersão de partículas de carvão a grandes distâncias e a alturas consideráveis. É desejável reduzir a emissão do poluente sem interferir na atividade operacional destes pátios de carvão, de forma a se obter ganhos ambientais e econômicos. Os efeitos da utilização de telas de proteção para reduzir o transporte eólico de partículas de carvão foram estudados através de ensaios em túnel de vento, medindo-se as distribuições das pressões médias e flutuantes sobre a superfície de um modelo reduzido, em escala 1/125, de uma pilha representativa de um pátio real de estocagem de carvão.Distintas porosidades de tela (68%, 53%, 37% e 0%), em três distintas configurações, dois afastamentos e a duas diferentes alturas foram testadas. Além das medidas de pressões, o campo de velocidades sobre a superfície e entorno das pilhas foi obtido através de medições com sistema de anemometria de fio quente. Percebe-se claramente que as velocidades médias do vento são mais altas próximo ao topo da pilha, e que a presença das telas causa uma redução destas velocidades nas regiões mais críticas. As telas com porosidades intermediárias mostraram-se mais eficazes em minorar os efeitos nocivos provocados pela combinação das sucções na superfície com as velocidades tangenciais de arrasto. Verificou-se que a redução da porosidade implica em uma redução na velocidade do vento atuante na pilha. Quando posicionada a barlavento, a tela com porosidade 0% (placa) causou um aumento da zona de recirculação atrás da mesma, aumentando, portanto, as sucções sobre a superfície da pilha. Entretanto, quando posicionada a sotavento, a placa sólida implicou em reduções significativas das pressões médias sobre a pilha. De uma forma geral, as telas com porosidades variando de 53% a 68% foram mais eficazes em reduzir as flutuações de pressão na face a barlavento da pilha, sem aumentar significativamente as pressões médias. Entretanto, as telas com porosidade em torno de 37% foram as mais eficientes em reduzir os picos de pressão que se desenvolvem a partir de incidências oblíquas do vento. / The effects of using wind fences to reduce wind-blown coal dust were studied through wind tunnel tests. The mean and fluctuating pressure distributions over the surface of reduced coal pile models were measured. The tests were performed at a 1/125 scaled model of a typical coal pile. Different fence porosities (68%, 53%, 37%, 0%) as well as different fence positions and heights were tested. Further to the pressure measurements, the field velocities over the surface and surroundings of the piles were obtained through hot-wire anemometry measurements. The fence with no porosity (0%) caused and increase in the re-circulating zone behind the fence, therefore increasing the negative pressures over the pile surface, being soon disregarded. The fences with porosities ranging from 53% to 68% were most effective in reducing the pressure fluctuations on the windward face of the pile, without increasing significantly the mean pressures over it. These pressures are closely related to the dust emissions from the surface, directly affecting the surrounding environment. Although most effective for reducing pressure fluctuations, the best combined effect together with the drag surface velocities were found for the fences with intermediate porosities. The 37% porosity fence was the most effective in reducing the oblique wind induced peak pressures.

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