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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

Physical and chemical aspects of water repellent soils affected by slashburning at Vancouver, British Columbia

Henderson, Greg January 1981 (has links)
The persistence and severity of water repellency in soils as affected by slashburning was examined in the municipal watersheds of Vancouver by the water drop penetration time (WDPT) and contact angle method, respectively. Also, hydrophobic materials were extracted from soil, separated by column adsorption chromatography, and analysed for functional groups by infrared absorption. Slashburning increased soil water repellency, as indicated by the WDPT method. Precise responses of soil repellency to slashburning were not consistent, as many site specific factors are involved, but increased repellency was evident in soil up to six years following burning. The severity of increased soil repellency caused by slashburning could not be assessed because contact angle determinations using the capillary rise equation and Darcy's Law were not reliable. The WDPT method was more consistent, reliable and simpler than the contact angle method, hence the WDPT method was considered best to indicate the presence of soil water repellency. A combination of polar and non-polar organic solvents, methanol and benzene respectively, extracted hydrophobic compounds from soil. The extractant separated into three fractions, using benzene and increasing proportions of acetone as eluting agents. Virtually all of the extract (90%) was recovered in Fraction I, indicating that the extraction was predominantly non-polar. Fraction II and III accounted for 4 and 6 per cent, respectively, of the applied extractables. Material in all Fractions induced repellency in wettable sand when 1 mg or more was applied to 5 gm of sand. Repellency was increased by heating the extracted materials in sand to 250°C for 10 minutes and was eliminated after heating to 300°C in inverse proportion to the mass applied. At 350°C, hydrophobic materials volatilized and the sand regained wettability. Analysis of an extraction by infrared absorption revealed that hydrophobic substances have hydrophilic and hydrophobic components. Adsorption of hydrophobic materials to soil particles is therefore likely initially by the hydrophilic end leaving the hydrophobic end of the organic molecule to form the outer surface thus preventing water from infiltrating. During slashburns, adsorption of hydrophobic materials is probably enhanced by optimization of close range van der Waals and London forces. / Forestry, Faculty of / Graduate
22

The economic feasibility of modifying six conventional harvesting systems to recover logging residues for fuel and fiber

Porter, Carl Donald January 1979 (has links)
This analysis provides a relative ranking of six Southern harvesting systems in terms of the costs, capitalization, and operational feasibility of incorporating a Trelan Model C-14 portable chipper or a residue baler to recover logging residues for fuel and fiber on three Southern stand types. The six systems were also considered under six cutting regimes to allow for the varying management objectives employed by woods managers in the South. The Harvesting Systems Simulator was used to perform the analyses. Data was collected from members of the American Pulpwood Association and equipment manufacturers in the South to use as input for the simulations. Each combination of system, stand, and regime was considered in terms of eight factors designed to express system performance. Results of the analysis indicated that logging residue recovery was economically feasible in many Southern harvesting systems. As long as conventional products are merchandized and the flow of those products through the harvesting system is not interrupted, residue recovery will be profitable on most southern stand types. Clearcutting fqr energy and thinning for energy were not economical on any stand due to the loss of revenues from conventional products. As woody fuel prices go up, this situation will change. Results· showed that the machine energy required to produce the residue energy was minimal for all systems on all stands and in all regimes. This indicates that residue recovery is not only economically feasible but energy efficient as well. / Master of Science
23

Recruitment trends and physical characteristics of course woody debris in Oregon Coast Range streams /

Heiman, David C. January 1988 (has links)
Thesis (M.S.)--Oregon State University, 1989. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.
24

Intimacy between men in modern women's writing

Woledge, Elizabeth January 2005 (has links)
This thesis sets out to investigate, and concludes by defining, a genre of modern women's writing. This genre, which 1 have called 'intimatopia' for its depiction of fictional worlds which centre around intimacy, explores close relationships between men, I use this thesis to elucidate the ideological assumptions which underlie this genre, as well as to consider the textual features which are commonly used to support them. My investigation is facilitated by my choice to focus on the appropriative fictions which form a significant part of the intimatopic genre. The appropriative text is particularly apposite to any project which, like this one, seeks to investigate distinctive ideologies, for in a comparison between the text and its source the ideological perspectives of the writer can be glimpsed. As a result of this approach one of the central features of this thesis is a comparison between hegemonic and intimatopic ideologies, which are found to be markedly different. Central to the intimatopic text, which may be sexually explicit, sexually discreet, or sexually ambiguous, is the assumption that there exists a fluid link between love, friendship and intimacy. This ideological perspective is one which many theoreticians, in fields as diverse as literary criticism, psychology and biology, have connected to feminine, rather than masculine, ways of thinking. Although it is therefore unsurprising to find that this is a feature of a predominantly feminine genre, its application to relationships between men runs counter to ideological assumptions about masculine interaction. From examining a variety of appropriative literature 1 move on to less overtly appropriative texts in which the by now familiar intimatopic features can be identified. Following this, 1 discuss the interpretive communities which produce intimatopic texts, using the example of slash fiction, where the interpretive community is readily accessible, I begin to investigate the ideological assumptions about human interaction which underpin the interpretations typical of intimatopic writing. Finally, I consider the genre's antecedents, and mention other texts which, although they do not take male intimacy as their theme, nonetheless share intimatopic features. Thus this thesis offers an insight into an area of women's writing which has received little critical attention and which I have been able to crystallise into the genre of intimatopia. Whilst it is clearly inaccurate to describe all women's writing as intimatopic, this genre accounts for a significant number of texts by women and should be recognised alongside other feminine genres as part of the varied field of women's literature.
25

Faktor Slash: charakteristika a typy slash fan fiction / Slash Factor: Characteristics and Varieties of Slash Fan Fiction

Cupalová, Lucie January 2014 (has links)
Lucie Cupalová - Master's Thesis The Slash Factor: Characteristics and Varieties of Slash Fan Fiction Abstract The aim of the thesis is to discuss specific characteristics of slash fan fiction, both as a subgenre of fan fiction and as a literary and social phenomenon. These characteristics are summarised as the "slash factor" of "slash texts". The beginning of the theoretical part focuses on the history and development of (slash) fan fiction, its various definitions and its role as a specific genre in literature. It summarises the basic premises and principles of fan fiction and explains them on slash fan fiction in particular. Sedgwick's homosocial - homosexual continuum in society is discussed, as well as its understanding and application on same-sex interactions, and several reasons for the reading and writing of slash fan fiction and its appeal are suggested. The main part of the thesis analyses actual slash fan fiction in three different fandoms: Harry Potter, Sherlock (Holmes), and Nightrunners. Each of them offers a different set of characters and slash tropes. Similarities and differences are sought in the stories written in different fandoms. Moreover, the Nightrunner series is analysed as an example of professionally published "slash text" which already features a gay couple as the main...
26

Slash burning and the effects on nutrient dynamics and soil faunal compostition in an Eucalyptus grandis plantation in South Africa

Nadel, Ryan Leslie 14 November 2006 (has links)
Student Number : 0002920M - MSc dissertation - School of Animal, Plant and Environmental Sciences - Faculty of Science / Sustainability of commercial plantations is dependent on the conservation of soil nutrients, especially on the ancient, leached soils of the tropics. This is particularly important when limited fertilization is practiced. To assess the sustainability of commercial plantations, various sustainability indicators have been suggested. One such indicator is that of biodiversity. The measurement of soil faunal diversity is important as soil fauna play an active role in the cycling of nutrients through the decomposition of plant residues and organic matter. The diversity and different feeding activities of soil fauna influence the rate at which nutrient cycling occurs either through microbial grazing, faecal deposition, the mixing of litter with the mineral soil as well as through the spreading of microbial inoculum. Management practices may, however, negatively influence nutrient availability through losses associated with the burning and removal of slash residues, thus changing the soil faunal community composition. In Eucalyptus grandis plantations in South Africa, the site is usually burned following the harvest and prior to replanting, which may markedly disrupt soil faunal function and nutrient availability. Soil biological processes, nutrient loss and soil faunal composition were the focus of this study. Nutrient losses associated with fire and slash management practices were determined by comparing the quantity of nutrients lost from the slash that was either spread or piled following burning. The in situ nitrogen and phosphorus mineralization rates and soil faunal composition were measured in six randomly located plots, three burned and three unburned, prior to and after a low intensity fire. Results indicate that 78 – 99% of phosphorus, nitrogen and carbon were lost from the slash as a result of burning, with a greater percentage loss occurring from the slash that was spread. It was further shown that within the burned plots the nitrogen availability was enhanced four fold within the first month following the fire. Phosphorus availability was also enhanced ten fold as a result of the burning, however, these effects on nitrogen and phosphorus availability were short lived. Soil faunal diversity was low both prior to and after burning. Ants are the dominant soil fauna. Soil faunal composition was more markedly influenced by season than by fire, with millipedes occurring in all plots in spring, prior to the fire and ants dominating in summer, post fire.
27

Modeling the impact of logging debris on the dissolved oxygen balance of small mountain streams /

Berry, John David. January 1974 (has links)
Thesis (M.S.)--Oregon State University, 1975. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.
28

Impact of slash loading on soil temperatures and aspen regeneration

Lieffers-Pritchard, Sarah Marie 11 April 2005
Natural regeneration is used to restock trembling aspen (Populus tremuloides Michx.) cutblocks and factors controlling regeneration are areas of interest and concern to the forest industry. Harvest operations in Manitoba require that coarse woody debris, or slash, be left and distributed in cutblocks. The objective of this study was to investigate the effects of slash loading on soil temperatures and aspen regeneration, and implications for harvest operations in the Duck Mountain area. Early sucker growth, initiation, and soil temperatures were surveyed in six winter and six summer cutblocks under different levels of slash loadings. A growth chamber study, using field temperature data as a guideline, examined the effects of diurnal temperature variation on sucker initiation and production. In winter and summer cutblocks, mean depths to sucker initiation from the parent root were 4.6 + 2.4 cm and 3.4 + 2.1 cm, respectively, and initiation of suckers occurred mainly from parental roots located in the LFH layer. Daily mean soil temperatures during the growing season were significantly lower under higher levels of slash (difference of 3.6 oC during May). Higher amounts of slash also significantly shortened the length of the growing season (89 fewer days above 0 oC in one season) and decreased the number of suckers produced (150 000 ha1 decreased to 14 000 ha-1), sucker volume (decreased by 256 cm3m-2) and leaf area index (decreased by 0.9). There was no difference in sucker production between any diurnal temperature treatments in the growth chamber study. Shallow depth to sucker initiation has important implications for harvest operations using heavy machinery especially those occurring during the summer season. Moderate levels of slash in summer cutblocks, and heavy levels of slash in winter cutblocks limit sucker growth. Although slash decreases diurnal temperature amplitudes, this may not be the reason for the decrease in sucker production associated with increased levels of slash. Both soil temperature and early sucker growth are strongly affected by slash loading; by monitoring harvest operations and the distribution of slash within cutblocks, the negative effect of heavy machine traffic and heavy piles of slash can be reduced and ensure successful forest regeneration.
29

Impact of slash loading on soil temperatures and aspen regeneration

Lieffers-Pritchard, Sarah Marie 11 April 2005 (has links)
Natural regeneration is used to restock trembling aspen (Populus tremuloides Michx.) cutblocks and factors controlling regeneration are areas of interest and concern to the forest industry. Harvest operations in Manitoba require that coarse woody debris, or slash, be left and distributed in cutblocks. The objective of this study was to investigate the effects of slash loading on soil temperatures and aspen regeneration, and implications for harvest operations in the Duck Mountain area. Early sucker growth, initiation, and soil temperatures were surveyed in six winter and six summer cutblocks under different levels of slash loadings. A growth chamber study, using field temperature data as a guideline, examined the effects of diurnal temperature variation on sucker initiation and production. In winter and summer cutblocks, mean depths to sucker initiation from the parent root were 4.6 + 2.4 cm and 3.4 + 2.1 cm, respectively, and initiation of suckers occurred mainly from parental roots located in the LFH layer. Daily mean soil temperatures during the growing season were significantly lower under higher levels of slash (difference of 3.6 oC during May). Higher amounts of slash also significantly shortened the length of the growing season (89 fewer days above 0 oC in one season) and decreased the number of suckers produced (150 000 ha1 decreased to 14 000 ha-1), sucker volume (decreased by 256 cm3m-2) and leaf area index (decreased by 0.9). There was no difference in sucker production between any diurnal temperature treatments in the growth chamber study. Shallow depth to sucker initiation has important implications for harvest operations using heavy machinery especially those occurring during the summer season. Moderate levels of slash in summer cutblocks, and heavy levels of slash in winter cutblocks limit sucker growth. Although slash decreases diurnal temperature amplitudes, this may not be the reason for the decrease in sucker production associated with increased levels of slash. Both soil temperature and early sucker growth are strongly affected by slash loading; by monitoring harvest operations and the distribution of slash within cutblocks, the negative effect of heavy machine traffic and heavy piles of slash can be reduced and ensure successful forest regeneration.
30

The sorption of certain slash pine hemicellulose fractions by cellulose fibers

Most, David S. 01 January 1957 (has links)
No description available.

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