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Jantan, Mohd Dahlan. "Chemical preservation of some refractory timber species of Malaysia." Thesis, University of Portsmouth, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310381.
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The treatability of six Malaysian timbers namely Red Balau (Shorea guiso), Kapur (Dryobafanops aromatica), Kasai (Pometia pinnata), Kulim (Scorodocarpus borneensis), Kempas (Koompassia malaccensis) and Keruing (Dipterocarpus grandiflorus) using the applied pressure processes (oscillating pressure, conventional Bethell and a modified Bethell process) was investigated. Treatments were carried out with a commercial water-borne copper-chromearsenic (CCA) preservative, known as Celcure-AP. The conventional Bethell process was the most effective method of wood treatment followed by the modified Bethell and the oscillating pressure process. While sufficient preservative retention and absorption was achieved in Kempas and Keruing to meet the Malaysian Standard MS 386 : 1986 specifications for exterior timber used in ground contact, the other four timbers - Red Balau, Kapur, Kasai and Kulim did not fulfil this requirement, even when treated at the most extreme treatment conditions. Using the three pressure processes, seasoning period and treatment time were found to have significant effects on preservative retention and penetration in all timber species. Investigations into the effect of three pretreatment procedures - steaming, incising and ponding to improve the treatability of the six timber species were carried out. Incising was the most effective pretreatment procedure in enhancing the treatability of these timbers. However, at the highest incising density employed (4,500 incisions/m2), it was still not possible to treat Red Balau, Kapur, Kasai and Kulim timber to achieve satisfactory target preservative retention and penetration. The less effective incising procedure was due mainly to the low incising density used. The possibility of improving the treatability of these four timber species further using higher incising densities and other methods of inCising pretreatment is discussed. Steaming, incising and ponding pretreatments had a pronounced effect on the strength properties of timbers based on reduction of their modulus of elasticity (M.D. E.), modulus of rupture (M.O.A.), compressive strength and hardness. The highest strength losses were observed in timbers that had been ponded for 6 months. Significant strength losses were also observed in incised and steamed timbers, but the magnitudes were lower than the 6 month ponding regime. This was attributed to low incising density and the short steaming period. The performance of Celcure-AP in the six timber species was evaluated in laboratory and field tests. In addition, a copper-azole formulation (Tanalith-3485) was also evaluated on Kempas timber. Laboratory tests involved exposure of treated wood blocks to five decay fungi - Pycnoporus sanguineus, Trametes versicolor, Coniophora puteana, Gloeophyllum trabeum and Oligoporus placenta. The less durable timbers - Kempas and Keruing needed a higher loading of Celcure-AP in order to give equal performance compared to the more durable timbers - Red Balau, Kapur, Kasai and Kulim. Based on copper retention in treated samples, a higher loading of Tanalith-3485 was required in Kempas to achieve comparable results to Celcure-AP treated samples. However, the concentration levels of Tanalith-3485 used in the present study were sufficient to afford protection to Kempas stakes exposed for 36 months in the field test. A longer exposure period is however, recommended for a full evaluation of timber/preservative combinations against wood deteriorating organisms under Malaysian conditions. In the field test, soft rot fungi were the main causal organisms in the attack of timbers in test site A (fungal test bed), while in test site B stake failure was due mainly to termite attack.
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Hart, Tim. "Stem profile equations for several commercially important timber species in Wisconsin /." Link to full text, 2009. http://epapers.uwsp.edu/thesis/2009/Hart.pdf.
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Thesis (M.S.)--University of Wisconsin--Stevens Point, 2009.Submitted in partial fulfillment of the requirements of the degree Master of Science in Natural Resources (Forestry), College of Natural Resources. Includes bibliographical references (leaves 82-87).
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Kelly, Anthony William. "The efficacy of boron-based preservatives in temperate and tropical timber species." Thesis, University of Portsmouth, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327771.
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Ando, Amy Whritenour. "Endangered species protection and National Forest timber sales : three essays in economics." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/10675.
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Torneport, Matilda. "Industrial Requirements for Cross-Laminated Timber Manufacturing." Thesis, Linnéuniversitetet, Institutionen för skog och träteknik (SOT), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-104924.
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Wood is a valuable sustainable material that meets the requirements for structural application. Cross-laminated timber (CLT) is a wood-based product that is mainly used in the building industry. Due to the rapid global market increase, a number of new CLT plants are emerging worldwide and thereby a need for standardisation is more than ever. There is no existing harmonised standard for CLT and it means a diversity between manufacturers, CLT products and its layup, which may in turn affects the properties of available CLT in the market. Therefore, this study was performed through literature study and internet-based interviews from five manufacturer in Sweden and Central Europe, to provide more information regarding the industrial requirements for CLT production. Three specific objectives of this study were: (1) wood and adhesive types in CLT production, (2) wood strength classes for CLT production, (3) important requirements for CLT producers and existing standards. Literature review and interviews showed that spruce (Picea abies L. Karst.) in combination with polyurethane (PUR) adhesive is the most commonly used materials in Europe for CLT production, which are approved by EN 16351 (2021). Other wood species, e.g., pine, poplar and birch can be used or are already used in a minor extent. Strength classes for lamellas in CLT are often C24, but timbers with lower strength grades are possible. Some manufacturer use combinations of different strength graded timber and in this small scale study different strength graded timber was in generally the biggest diversity between manufactures. Only a few material properties such as modulus of elasticity, modulus of rupture, compression and shear strength are listed in EN 16351 (2021) and EN 338 (2016), as the factors for quality measurements of the CLT products. This study, however, showed that the critical material properties for the most interviewed CLT producers are merely modulus of elasticity and rarely modulus of rupture.
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Schulze, Mark D. "Ecology and behavior of nine timber tree species in Pará, Brazil : links between species life history and forest management and conservation /." View online version of this title, 2003. http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-436/index.html.
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Devine, Kevin Patrick. "INITIAL RESPONSE OF INVASIVE EXOTIC PLANT SPECIES TO TIMBER HARVESTING IN SOUTHEASTERN KENTUCKY FORESTS." UKnowledge, 2011. http://uknowledge.uky.edu/gradschool_theses/650.
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The responses of invasive exotic plant species (IES) to silvicultural treatments one growing season after timber harvesting were examined in the Cumberland Plateau region of Southeastern Kentucky. Treatments included a commercial deferment harvest and unharvested control applied to five watersheds within University of Kentucky’s Robinson Forest. The effects of harvesting were compared between treatments and between preharvest and postharvest samplings. The spatial distribution and abundance of targeted IES throughout forest sites and trail systems were calculated from several sampling schemes. Additional analyses were performed to quantify forest disturbances derived from harvest activities to determine the relationships between soil, light levels, and other environmental characteristics and IES cover. Logistic and multivariate analysis techniques were used to analyze differences in IES distribution between pre-harvest and post-harvest units to relate post-harvest IES to microsite conditions. Microsite conditions within the forest and along the trail system proved important for explaining the presence and distribution of IES. Timber harvesting caused a significant increase in both Ailanthus altissima and Microstegium vimineum within harvested areas. However, many other identified IES did not initially respond to disturbances. Throughout the treatment units, species were influenced by disturbance type and intensity, as well as proximity to reclaimed surface mined land.
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Fuchs, Sebastian Mario [Verfasser]. "Diverse forests for climate change: Drought stress tolerance of secondary timber species / Sebastian Mario Fuchs." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2021. http://d-nb.info/1239894678/34.
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Boakye-Yiadom, Kaleem. "Selected anatomical, extractive and physical wood properties of Cylicodiscus gabunensis (Harm) : a tropical timber species /." free to MU campus, to others for purchase, 2001. http://wwwlib.umi.com/cr/mo/fullcit?p3036806.
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Mark, Jennifer. "Applications of the IUCN Red List in evaluating global extinction risk of timber tree species." Thesis, Bournemouth University, 2018. http://eprints.bournemouth.ac.uk/30531/.
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Anthropogenic deforestation and habitat degradation are major pressures on biodiversity. The world’s wild-growth timber tree species additionally face pressure from unsustainable and illegal harvest practices. Despite the threats to these economically valuable species, our understanding of their extinction risk remains incomplete and outdated. In fact, many timber tree taxa are marketed under trade names only, making it difficult to identify those most at risk. An additional challenge is presented by limited data and the pressing need for rapid species assessment in order to inform conservation actions. However, the use of ‘big data’ is coming to the fore in ecological research, and offers a valuable chance to meet international assessment targets such as those of The Global Strategy for Plant Conservation (GSPC), which call for knowledge of the conservation status of all known plant species to guide conservation actions (GSPC Target 2), in addition to sustainable harvesting of all wild- sourced plant-based products (GSPC Target 12), by the year 2020 (CBD, 2012). This thesis therefore aimed to identify timber tree taxa in trade at the species level; to assess utility of occurrence records from the Global Biodiversity Information Facility (GBIF) in timber species range mapping; to assess current extinction risk of a priority subset of timber tree species by applying the IUCN Red List (Red List) of Threatened Species Categories and Criteria; and, lastly, to evaluate the uncertainty of these preliminary Red List assessments. Consolidation of open-access timber lists produced a ‘working list’ of 1,578 angiosperm timber taxa in trade. GBIF records were demonstrated to be a suitable low time-cost resource with which to estimate species extent of occurrence and prioritise range-restricted timber tree species for Red List assessment. In addition to GBIF datasets, Global Forest Change (GFC) satellite imagery was found to be a valuable resource for assessing timber tree species range size, habitat fragmentation, and population trends over time. Preliminary Red List assessments conducted for 324 timber tree species suggest that some 69% may be threatened with extinction if current rates of deforestation persist. Although GBIF and GFC ‘big data’ were found to introduce some uncertainty into timber tree Red List categorisations, quantitative comparison to assessments conducted using ‘expert’ datasets suggested that categorisations were not greatly impacted. Furthermore, these evaluations illustrated the scarcity and inaccessibility of more traditional sources of Red List assessment data for timber tree species. It is evident that if we are to meet GSPC and other conservation targets for timbers and other at-risk, poorly-known tree taxa, we must recognise that open-access ‘big data’ repositories represent a powerful opportunity for Red Listing.
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Ofori, Daniel Aninagyei. "Genetic diversity and its implications for the management and conservation of Milicia species." Thesis, University of Aberdeen, 2001. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU142070.
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This study describes the population genetic structure of Milicia species sampled from different provenances distributed over 5 countries (Sierra Leone, Cote d'Ivoire, Ghana, Cameroon and Tanzania). Random amplified polymorphic DNA (RAPD) and inter sample sequence repeats (ISSR) variation in 41 accessions from 5 different populations were consistent with each other. Analysis of molecular variance partitioned RAPD and ISSR variation into within- and between-population components. The between-population variation component was large, accounting for 62.2% and 71.5% for RAPD and ISSR respectively. Dendrogram analysis produced 2 major clusters separating dry zone accessions (mainly M. excelsa) from moist/wet zone accessions (mainly M. regia). Sub-clustering further separated accessions by forest type and/or geographic region. Phylogenetic analysis of chloroplast genes involved the use of nucleotide sequencing, restriction fragment length polymorphism (RFLP), and microsatellites. Only one region (5' to trnS) out of 6 regions analysed was polymorphic and revealed 3 different cytotypes. The distribution of the cytotypes matched with the 2 major clusters produced by the dominant markers. Wet/moist and dry zone bands were identified with little evidence of gene flow between populations. Seed mediated gene flow estimated from the chloroplast analysis was small (Nm = 0.23). To relate these molecular information with Phytolyma resistance, field provenance and progeny trials were conducted. Accessions from wet/moist zones were more tolerant to Phytolyma than accessions from dry zone. The data also suggest that accessions bearing the wet/moist zone specific markers have a high probability of being tolerant to Phytolyma. The approaches outlined and the results have general applicability in the sustainability of Milicia spp. and are discussed in relation to germplasm sampling, management and conservation of genetic recourses of Milicia species.
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Firmanti, Anita. "Fire endurance of the graded timber and wood based panels from the fast-growing tropical species." Kyoto University, 2005. http://hdl.handle.net/2433/145003.
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Kyoto University (京都大学)0048
新制・論文博士
博士(農学)
乙第11684号
論農博第2567号
新制||農||915(附属図書館)
学位論文||H17||N4067(農学部図書室)
23497
UT51-2005-D602
(主査)教授 川井 秀一, 教授 小松 幸平, 教授 矢野 浩之
学位規則第4条第2項該当
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Rara, Angela Dominique Sarmiento. "Rolling Shear Strength and Modulus for Various Southeastern US Wood Species using the Two-Plate Shear Test." Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/104017.
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Cross-Laminated Timber (CLT) is an engineered wood product made by laminating dimensional or structural composite lumber in alternating orthogonal layers. Compared to Canada and Europe, CLT is a novel product to the US. With the additions included in the 2021 International Building Code (IBC), CLT material properties, especially rolling shear, would need to be explored. The increasing demand for softwood lumber, along with the increase of demand of CLT panel production, could place a burden and surpass the domestic softwood supply. Rolling shear is a phenomenon that occurs when the wood fibers in the cross-layers roll over each other because of the shearing forces acting upon a CLT panel when it is loaded out-of-plane. This study used the two-plate shear test from ASTM D2718 to measure the rolling shear properties of various southeastern US wood species: southern pine, yellow-poplar, and soft maple. A secondary study was conducted, using the same two-plate shear test, to measure the rolling shear properties of re-manufactured southern pine for CLT cross-layer application. The soft maple had the greatest average rolling shear strength at 5.93 N/mm2 and southern pine had the lowest average rolling shear strength at 2.51 N/mm2. Using a single factor analysis of variance (ANOVA), the rolling shear strength values from soft maple were significantly greater than yellow-poplar, which was significantly greater than the southern pine. For the rolling shear modulus, the southern pine and soft maple were of equal statistically significant difference, and both were greater statistically significant different compared to the yellow-poplar. The most common failure found from testing was rolling shear.Master of Science
Cross-Laminated Timber (CLT) is an engineered wood panel product, similar to plywood, constructed with solid-sawn or structural composite lumber in alternating perpendicular layers. The additions included in the incoming 2021 International Building Code (IBC) has placed an importance in expanding the research related to the mechanical and material properties of CLT. Also, with the increasing demand for softwood lumber and CLT panel production, the demand for the domestic softwood lumber could place a burden and surpass the domestic softwood supply. Rolling shear is a failure type that occurs when the wood fibers in the cross-layers roll over each other because of the shearing forces acting upon a CLT panel. This study used the two-plate shear test to measure the rolling shear properties of various southeastern US wood species: southern pine, yellow-poplar, and soft maple. A secondary study was conducted, using the same two-plate shear test, to measure the rolling shear properties of re-manufactured southern pine for CLT cross-layer application. The soft maple had the greatest average rolling shear strength at 5.93 N/mm2 and southern pine had the lowest average rolling shear strength at 2.51 N/mm2. Using a single factor analysis of variance (ANOVA), the rolling shear strength values from soft maple were significantly greater than yellow-poplar, which was significantly greater than the southern pine. For the rolling shear modulus, the southern pine and soft maple were of equal statistically significant difference, and both were greater statistically significant different compared to the yellow-poplar. The most common failure found from testing was rolling shear.
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Soto, Embodas Iria. "A domestication strategy of indigenous premium timber species by smallholders in Central Visayas and Northern Mindanao, the Philippines." Thesis, Uppsala universitet, Systematisk biologi, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-141830.
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Cowell, Anthony Michael. "Growing timber trees with straight stems : an exploration of relationships between morphological traits in some broadleaved tree species." Thesis, De Montfort University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.727131.
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Vinson, Christina C. "Impact of selective logging on inbreeding and gene flow in two Amazonian timber species with contrasting ecological and reproductive characteristics." Thesis, University of Oxford, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.510253.
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Hansen, Simone. "How flower visitation of remnant grassland patches is affected by commercial timber plantations and an invasive alien species (Rubus cuneifolius)." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/98051.
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Thesis (MSc)--Stellenbosch University, 2015.ENGLISH ABSTRACT: Our planet is in the midst of a biodiversity crisis, with factors such as land transformation, climate change, anthropomorphic disturbance and invasive species acting together to threaten biodiversity. In South Africa, with minimal natural wood resources, commercial forestry is one of the most abundant forms of landscape transformation. However, a third of the land inside many plantations has been set aside for conservation as unplanted remnant grassland patches (RGPs). These areas are subjected to an additional negative impact by invasive alien species, namely Rubus cuneifolius (American bramble), a weed that is particularly problematic in and around forestry plantations in South Africa. The grassland biome of South Africa is extremely diverse and is of vital importance for the ecosystem services it supplies. Despite this, the grassland biome is under threat as this is where much of South Africa’s forestry plantations are located. Driven by anthropomorphic disturbance, pollinators are in decline. Landscape transformation of natural areas for forestry plantations is likely to affect plant-pollinator interactions which will affect ecosystems and biodiversity. However, it is not known to what extent these ecosystems are affected. It is thought that the impact depends on the complexity of the ecosystem in question, and analyses at the network-level provide insights into the robustness of ecosystems in the face of biodiversity loss. Thus, this study evaluates the effect of natural habitat fragmentation and invasion of the alien species, R. cuneifolius, on flower visitation networks of South African grasslands. The study was conducted in the KwaZulu-Natal Midlands within a commercial timber plantation and a neighbouring protected area (PA). Flower-visitor observations were carried out in uninvaded protected areas and RGPs and in protected areas and RGPs invaded by R. cuneifolius. I found that RGPs within commercial forestry plantations successfully decrease the negative effects of land transformation on the grasslands of the KwaZulu-Natal Midlands, and flower visitation network patterns are largely maintained in these habitat fragments. However, within RGPs, invasion by R. cuneifolius affected the composition and the interaction network structure of flower-visitor and plant communities. The fact that there are unplanted areas within commercial forestry plantations is positive for biodiversity conservation in South Africa. Research has indicated that these areas successfully aid in the conservation of biodiversity and ecosystem functioning. Due to the positive influence that RGPs have on conservation in fragmented and transformed landscapes, it is critical that these unplanted areas are retained. However, the effects of bramble invasion are more intense within RGPs than within protected areas, and therefore, it must be a priority to keep these areas undisturbed. R. cuneifolius has been found to have devastating effects on ecosystem function and network structure. It is also a category 1 invasive plant within South Africa, and its removal is required by law. Therefore, the removal of bramble must be a management priority.
AFRIKAANSE OPSOMMING: Ons planeet is in die middel van 'n biodiversiteit krisis, met faktore soos grond transformasie, klimaatsverandering, antropomorfiese versteuring en indringerspesies wat gesamentlik werk om biodiversiteit te bedreig. Suid-Afrika, besit minimale houtbronne. Daarom is kommersiële bosbou een van die mees algemene vorme van landskap transformasie. Tog is 'n derde van die land binne baie plantasies opsy gesit vir bewaring as oorblywende grasveld kolle (OGKs). Hierdie gebiede word ongelukkig blootgestel aan die bykomende negatiewe impak van die uitheemse spesies, Rubus cuneifolius (Amerikaanse steekdoring), wat veral problematies is in en rondom bosbouplantasies. Die grasveldbioom van Suid-Afrika is baie divers en is van kardinale belang vir die ekosisteem dienste wat dit lewer. Ten spyte hiervan, word die grasveldbioom bedreig waar dit op dieselfde areas as die meerderheid van Suid-Afrika se bosbouplantasies geleë is. Antropomorfiese versteuring lui daartoe dat bestuiwergetalle daal. Landskap transformasie vir bosbou plantasies raak dus plant-bestuiwer interaksies, wat ekosisteme en biodiversiteit beïnvloed. Dit is nie bekend tot watter mate hierdie ekosisteme geraak word nie. Daar word vermoed dat die impak af hang van die kompleksiteit van die ekosisteem. Ontledings van ekosisteme op netwerk vlak kan insigte bied oor die robuustheid van hierdie ekosisteme in die aangesig van biodiversiteitverlies. Dus, die studie evalueer die effek van fragmentasie van natuurlike habitatte en inval van die indringer spesie, R. cuneifolius, op blom-besoekings netwerke van Suid-Afrikaanse grasvelde. Hierdie studie is uitgevoer in die KwaZulu-Natal Midlands binne 'n kommersiële hout plantasie en 'n naburige beskermde gebied (BG). Blom-besoeker waarnemings was in BGs en OGKs sonder R. cuneifolius, en in BGs en OGKs met R. cuneifolius uitgevoer. Ek het gevind dat OGKs binne kommersiële bosbouplantasies suksesvol is om die negatiewe uitwerking van land transformasie te verminder, en blom-besoeking netwerk patrone grootliks gehandhaaf word in hierdie habitat fragmente. Egter, binne OGKs, het R. cuneifolius die samestelling en die interaksie netwerk struktuur van blom-besoekers en plant gemeenskappe negatief geraak. Die feit dat OGKs ongeplant gelaat word, is positief vir die bewaring van biodiversiteit in Suid- Afrika. Navorsing dui aan dat hierdie gebiede suksesvol is om te help met die bewaring van biodiversiteit en ekosisteemfunksionering. As gevolg van die positiewe invloed van OGKs op bewaring in gefragmenteerde en omskepte landskappe, is dit krities dat hierdie areas ongeplant bly. Egter, die gevolge van steekdoring inval is meer intens binne OGKs as binne beskermde gebiede, en daarom moet dit 'n prioriteit wees om hierdie gebiede ongestoord te hou. R. cuneifolius se verwoestende uitwerking op ekosisteem funksie en netwerk struktuur was baie duidelik. Dit is ook 'n kategorie 1 indringerplant in Suid-Afrika, en sy verwydering word deur is die wet vereis. Daarom moet die verwydering van steekdoring ‘n bestuursprioriteit wees.
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Hagemeier, Andrew James. "The Effects of De-Listing the Grizzly Bear from the Endangered Species Act on Timber Management in the Yellowstone Ecosystem." Thesis, The University of Arizona, 2007. http://hdl.handle.net/10150/190429.
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When the grizzly bear is delisted from the Yellowstone Ecosystem, strict federal standards regulating timber management on the surrounding National Forests will elapse, and new standards written to protect grizzly bear habitat will take their place. Controversy surrounds this change in management, with some believing this will result in an increase in logging. This paper address how will the delisting may effect timber management on National Forest surrounding Yellowstone National Park. Comparing the documents that guided the management of grizzly bear populations and habitat as a listed species, and the documents guiding management post-delisting, has shown there were many standards and guidelines controlling the size, shape, location, and timing of timber sales in occupied grizzly bear habitat. When the bear is delisted, there will only be one standard controlling the size, shape, location, and timing of timber sales. This one standard will allow greater flexibility in how timber sales are designed, which may result in slight increases in the size of timber sales in occupied grizzly bear habitat.
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Rasp, Benjamin Christopher. "SPATIAL AND TEMPORAL PATTERNS OF INVASIVE EXOTIC PLANT SPECIES IN RESPONSE TO TIMBER HARVESTING IN A MIXED MESOPHYTIC FOREST OF EASTERN KENTUCKY." UKnowledge, 2019. https://uknowledge.uky.edu/forestry_etds/45.
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Invasive exotic species (IES) responses to silvicultural treatments eight years after timber harvesting were examined and compared to one-year post-harvest IES survey in University of Kentucky’s Robinson Forest. The temporal effects of harvesting were further compared between harvested and non-harvested watersheds. Analyses were performed to identify IES spatial distribution and determine the relationships between IES presence and disturbance effects, biological, and environmental characteristics. IES prevalence was higher in the harvested watersheds and was influenced by canopy cover, shrub cover and disturbance proximity. Ailanthus altissima and Microstegium vimineum presence in the study area has decreased over time. Comparing to the 1-yr post-harvest study which only identified direct harvesting effects (e.g. canopy cover and disturbance proximities) as significant predictors, the 8-yr post-harvest survey results suggest that while harvesting effects and disturbance proximity still play an important role, environmental characteristics have also taken precedence in predicting IES presence. Overall IES prevalence has decreased but invasive plant species richness has increased over time. Results indicate that IES eradication may not need to be conducted immediately after harvesting, and when needed, can primarily target IES hotspots where low canopy cover, proximity to disturbance, and southwest facing slopes convene on the landscape.
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Fredrickson, H. Signy. "Non-timber forest products, a study of salal productivity, inventory of commercial plant and fungus species, and recommendations for management on the Nanaimo rifle range lands." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0017/MQ54584.pdf.
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Vanden, Abeele Samuel. "Comparative phylogeography of widespread tree species from the Congo Basin." Doctoral thesis, Universite Libre de Bruxelles, 2019. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/298065.
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The aim of this PhD study was to gain new insights into the evolutionary history of the Central African rainforests, which are among the most complex and diverse ecosystems on earth. Even today, many questions regarding the underlying dynamics and evolutionary processes shaping that remarkable diversity remain unanswered, since relatively few studies have focused on the vast tropical forests growing in the Congo Basin. Therefore, we applied various molecular approaches to study the levels of genetic diversity and patterns of differentiation within and between population of the tropical tree species Scorodophloeus zenkeri, Staudtia kamerunensis and Prioria balsamifera. In Chapter 2, we conducted a phylogeographic study on the widespread tropical tree Scorodophloeus zenkeri to assess the impact of past forest fragmentation in Central African lowland forests. By applying Bayesian clustering methods, we revealed six intraspecific genetic clusters within the species. The observed genetic discontinuities most likely result from forest fragmentation during the glacial periods of the Pleistocene. Populations in Lower Guinea appeared differentiated from those in Congolia, and both bioregions harboured distinct genetic clusters.In Chapter 3, we developed 16 highly polymorphic microsatellite primers (SSRs) for Staudtia kamerunensis, a timber species for which species-specific genetic markers were lacking. By validating the developed markers in three populations, we demonstrated their usefulness to study gene flow, population structure and spatial distribution of genetic diversity in S. kamerunensis.In Chapter 4, we applied the newly developed SSRs, two nuclear gene markers and a chloroplast marker to search for evolutionary lineages in Staudtia kamerunensis, a species with a complex taxonomical history. Our analyses reveal multiple genetic discontinuities among populations throughout Central Africa, probably resulting from ancient rainforest fragmentation during cold and dry periods in the Pliocene and/or Pleistocene. However, the clear genetic disjunction observed between northern and southern populations in Lower Guinea could correspond to a genetic break between the kamerunensis and gabonensis varieties described in Staudtia kamerunensis.In Chapter 5, we developed two new sets of microsatellite primers (SSRs); 16 primer pairs for Prioria balsamifera and 15 primer pairs for Prioria oxyphylla. Validation of the primers in two populations of each species, as well as the cross-amplification tests, demonstrated the usefulness of the SSRs to study gene flow and spatial genetic structure in African Prioria species, which is needed to prevent genetic erosion and to set up proper conservation guidelines.In Chapter 6, the 16 newly developed microsatellite loci were amplified in individuals of P. balsamifera from Gabon and the Democratic Republic of the Congo, to assess the levels of genetic diversity and intraspecific differentiation. Our analyses show that the genetic diversity in P. balsamifera populations is relatively low, so efforts should be made to prevent further depletion of the gene pool. Bayesian clustering analyses revealed multiple genetic discontinuities throughout the Congo Basin, probably caused by ancient forest fragmentation. The inferred intraspecific clusters show a parapatric distribution, so they can potentially be used to determine the origin of individuals at a regional scale. Additionally, various genetic assignment methods show that the SSR dataset generated in this study can be used as a reference database for Gabon and DR Congo. The general discussion allows us to show similarities in the genetic structures of species that can be interpreted in terms of forest cover history in Central Africa.Doctorat en Sciences
info:eu-repo/semantics/nonPublished
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Vrazel, Matthew Eric. "The effects of species, adhesive type, and cure temperature on the strength and durability of a structural finger joint." Thesis, Mississippi State : Mississippi State University, 2002. http://library.msstate.edu/etd/show.asp?etd=etd-05152002-122630.
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Schumann, Katharina [Verfasser], Rüdiger [Akademischer Betreuer] Wittig, and Georg [Akademischer Betreuer] Ziska. "Impact of land-use on savanna vegetation and populations of non-timber forest product-providing tree species in West Africa / Katharina Schumann. Gutachter: Rüdiger Wittig ; Georg Ziska." Frankfurt am Main : Univ.-Bibliothek Frankfurt am Main, 2011. http://d-nb.info/1044772131/34.
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Icimoto, Felipe Hideyoshi. "Dormentes em madeira laminada colada de Pinus oocarpa." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/18/18158/tde-23012014-110222/.
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Em 2012 foi anunciado um pacote econômico do governo que concede à iniciativa privada a operação de estradas e ferrovias pelo Brasil, onde serão investidos R$ 133 bilhões, incluindo a construção de 10 mil quilômetros de estradas de ferro. O dormente é um dos componentes estruturais mais importantes na construção de ferrovias, com a função de receber esforços produzidos pelos veículos ferroviários, amortecer parcialmente as vibrações, transmiti-las ao lastro e manter invariável a distância entre os trilhos (bitola). As madeiras utilizadas no Brasil para a produção de dormentes são de essências nobres. Porém, com a escassez cada vez maior dessas espécies e a exploração ilegal de madeiras nativas consideradas de elevada resistência buscaram-se madeiras alternativas para esse uso como o Eucalipto ou o Pinus de florestas plantadas. Objetivo deste trabalho foi a análise experimental da viabilidade técnica da produção de dormentes pelo método de fabricação da Madeira Laminada Colada utilizando a madeira da espécie de Pinus oocarpa e adesivo poliuretano para atender os requisitos da recém aprovada norma de dormentes ABNT NBR 7511:2013 Dormentes de madeira - Requisitos e métodos de ensaio. Após intenso programa experimental em que foram estudadas diversas configurações de disposição de lamelas visando à otimização do processo de fabricação, foram produzidos dormentes de MLC com configurações diferentes de seção transversal, e realizados ensaios preliminares com a finalidade de atingir as especificações mínimas de norma. Os resultados mostraram que os dormentes em MLC de Pinus oocarpa atingiram os requisitos da norma ABNT NBR 7511:2013 Dormentes de madeira - Requisitos e métodos de ensaio.In 2012 it was announced a government economic package that grants to private operation of roads and railways in Brazil, which will be invested R$ 133 billion, including the construction of 10,000 km railroads. Sleepers are one of the most important structural components in the construction of railways with the function of receiving actions produced by the rail vehicles, diminish dampen vibrations and transmitting them to the ballast and remain invariant distance between rails (gauge). The timbers used in Brazil to manufacture sleepers are from tropical forest. Considering the scarcity and tropical illegal logging, Eucalyptus and Pines planted forests are a interesting alternative. The aim of this study was experimental analyze of the technical feasibility to produce Glulam sleepers using Pinus oocarpa species and polyurethane adhesive to reach the requirements of the recently approved sleepers standard ABNT NBR 7511:2013 Wood sleepers - Requirements and test methods. After intensive experimental program using various layout settings of lamellae and different configurations of cross-sectional an optimization of the manufacturing process of MLC sleepers was done in order to achieve the minimum standard specifications. Results showed that in MLC sleepers of Pinus oocarpa reached the requirements of the standard ABNT NBR 7511:2013 Wood sleepers - Requirements and test methods.
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Isik, Aydin. "Disassembly And Re-use Of Building Materials: A Case Study On Salvaged Timber Components." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1042431/index.pdf.
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The objective of this study was to investigate the feasibility of using salvaged timber from deconstructed buildings in Turkey. The intention was to show that the re-use of &lsquowaste&rsquo
materials, while decreasing the cost of construction also preserves the environment from wasteful and extensive use of natural resources. It is hoped that the findings of such a study will encourage professionals to use second hand timber components in Turkey. In order to deal with the waste problem and to save our planet the re-use of construction materials from economic, environmental, social, and historic points of views should be pursued. This research incorporated information about the re-use of timber, including ongoing projects around the world, as reported by the International Council for Research and Innovation in Building Construction (CIB) Task Group on Deconstruction (TG39), a local survey of individuals, organizations, and businesses that are related to the recycling and reuse of building materials. Local deconstruction works, recovery and re-use of timber elements and components were investigated on the basis of information obtained from the demolition contractors in Bentderesi locality in Ankara, a salvaged materials market. iii Moreover the study aimed to observe how used timber components are recovered from a demolition project. By observing the demolition of a building the author was able to determine the problems in recovering timber with the least damage. The findings of the investigation indicated that the architects and the building industry can play an important role to increase recovery rates and conditions of used timber components in construction, considerably. Instead of using nails for timber joints bolted connections should be preferred since they allow demounting and re-use with minimum damage during the deconstruction process. At the same time defects in timber due to extensive and unnecessary nailing can also be avoided. The decision on type of deconstruction, time and cost estimation, worker ability and sensitivity during disassembly influence the success of deconstruction. Tools and machinery used both on the work site and in the UBMs selling area have direct effects on the condition of recovered materials.
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Soja, Morgan C. "The effect of timbre and pitch-pattern difficulty on the pitch perceptions of elementary-aged users of cochlear implants." Thesis, The University of North Carolina at Greensboro, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3708183.
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The purpose of this study was to examine the effects of timbre and pitch-pattern difficulty on perceptions of same-difference between paired pitch patterns, altered and unaltered by timbre and pattern difficulty, among elementary-aged users of cochlear implants. Three null hypotheses were tested to determine the significant effects of these variables and their interaction on the pitch perceptions of children aged five through twelve, who used cochlear implants (p ≤ .05). Secondary purposes of the study included the examination of the relationships, if any, among age, age at implantation, and pitch perceptions, and of significant differences between participants' speech processor and pitch perceptions (p ≤ .05).
The Adapted Musical Background Questionnaire was completed by each participant/parent/guardian and used to collect information about each participant's hearing history and musical experiences. The Pitch Discrimination Test (PDT) was a researcher-developed, 36-item data collection instrument used to measure pitch perceptions of participants. Three timbres were used as stimuli, including the soprano voice, piano, and violin. Thirteen participant responses to the PDT were recorded individually. Results were analyzed using IBM© SPSS© Statistics Version 22.
Results of the study revealed no effect of timbre (p = .511), or pitch-pattern difficulty (p = .971) on pitch perceptions. A significant interaction between timbre and pitch-pattern difficulty, however, was found (p = .046). Additional analyses revealed that there were significant differences between mean scores of PDT test items presented by violin and soprano voice for difficult patterns (p = .041), and items presented by soprano and piano for patterns with moderate difficulty (p = .041). The participants discriminated difficult patterns more accurately when the PDT items were presented by soprano voice than piano, but participants discriminated moderate patterns more accurately when the PDT items were presented piano than by soprano voice.
There were no significant positive or negative correlations between age or age at implantation and PDT scores (p > .05). Additionally, there were no significant differences between participant scores on the PDT and the type of speech processor used (p > .05). Participants who used Cochlear™ devices, however, had higher average scores than participants who used MED-EL® devices. Recommendations were suggested for future research and instruction of children who use cochlear implants in elementary general music classrooms.
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Tyley, Phillip L. "Photodissociation of atmospherically important species." Thesis, University of Oxford, 2000. http://ora.ox.ac.uk/objects/uuid:47f66021-d54e-4f86-ab82-f8cd902b34f6.
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The photodissociation of ozone by ultraviolet light has a great impact on the photochemistry of the atmosphere. The relative quantum yield for the production of the singlet atomic fragment O(1D) has been determined in the wavelength region 306 to 327 nm for four temperatures between 227 K and 300 K. The technique of resonance enhanced multi photon ionisation (REMPI) was used to probe directly the O(1D) photolysis product. These relative measurements have been placed onto an absolute scale by the selection of a calibration point whose value has been agreed by the scientific community. The yields obtained are in good agreement with others reported during the time of the research reported in this thesis and clearly show that three mechanisms contribute to the final quantum yield. Below 310 nm, O(1D) is produced by a spin-allowed channel, above 320 nm the primary channel is a spin- forbidden one and at intermediate wavelengths photolysis of vibrationally excited ozone contributes to the O(1D) yield. Elements of the quantum yield data presented in this thesis are being included in a new recommendation for the temperature dependent O(1D) quantum yield. Details of the dissociation kinetics, including further evidence confirming the spin-forbidden channel, is presented in time-of-flight studies of the O(1D) product. Time-of-flight profiles taken between 317 and 321 nm show evidence that, at room temperature, the O(1D) quantum yield is anti-correlated with the ozone absorption cross section. Excitation of the O2(a1Δg) co-fragment has been observed at wavelengths below 296 nm by monitoring the energies of the O(1D) formed. As the channel for the production of O2(a1Δg,andnbsp;vandnbsp;=andnbsp;1) opens, it is found that energy is preferentially partitioned into rotation of the O2 fragment rather than into translation. Initial studies on the O(1D) fragment have shown that the fragment is orbitally aligned and that the choice of REMPI transition can have a significant effect on the time-of-flight profiles and therefore on the measurements that are made from the profiles. The time-of-flight profiles obtained by probing the O2(a1Δg) photofragment have shown that the O2(a1Δg) has an angular momentum polarisation that is J dependent, with the even J being strongly polarised and the odd J depolarised. This results in the shape of the time-of-flight profiles being a function of the REMPI laser polarisation; and the study of this behaviour has been used to confirm the assignments in highly perturbed REMPI spectra.
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Woon, Weng-Chuen. "The economic valuation of Parkia speciosa (petai) in peninsular Malaysia." Thesis, Bangor University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261341.
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Duan, Shufei. "Automated species recognition in environmental recordings." Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/71390/1/Shufei_Duan_Thesis.pdf.
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Faunal vocalisations are vital indicators for environmental change and faunal vocalisation analysis can provide information for answering ecological questions. Therefore, automated species recognition in environmental recordings has become a critical research area. This thesis presents an automated species recognition approach named Timed and Probabilistic Automata. A small lexicon for describing animal calls is defined, six algorithms for acoustic component detection are developed, and a series of species recognisers are built and evaluated.The presented automated species recognition approach yields significant improvement on the analysis performance over a real world dataset, and may be transferred to commercial software in the future.
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Sullivan, June Eileen Marie 1957. "Seeding dates and field establishment of ten southwestern desert wildflower species." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276818.
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The effects of planting date were evaluated on field establishment and flowering of ten southwestern wildflower species combined in a mix. Species tested include Baileya multiradiata, Castilleja lanata, Eschscholtzia californica, Eschscholtzia mexicana, Gaillardia pulchellum, Lesquerella gordonii, Lupinus sparsiflorus, Orthocarpus purpurascens, Penstemon eatonii, and Phacelia campanularia. Seeds of all species were combined in a mix and directly seeded into field plots. All species are native to the southwestern deserts of the United States. Treatments consisted of five planting dates, starting September 30, 1987 and continuing through November 30, 1987, with treatments planted at two week intervals during the ten week period. There were significant differences in both plant stand and flowering between planting dates. The October 15 planting had the optimum plant stand with regard to the largest spectrum of species represented by desirable numbers. Flowering was most pronounced in the September 30 and October 15 plantings.
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Borrvall, Charlotte. "Biodiversity and Species Extinctions in Model Food Webs." Doctoral thesis, Linköping : Department of Physics, Chemistry and Biology, Linköping University, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-6660.
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Binder, Michael. "Development of a Botrytis specific immunosensor : towards using PCR species identification." Thesis, Cranfield University, 2014. http://dspace.lib.cranfield.ac.uk/handle/1826/12110.
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Botrytis species affect over 300 host plants in all climate areas of the world, at both pre
and post-harvest stages, leading to significant losses in agricultural produce. Therefore,
the development of a rapid, sensitive and reliable method to assess the pathogen load of
infected crops can help to prescribe an effective curing regime. Growers would then
have the ability to predict and manage the full storage potential of their crops and thus
provide an effective disease control and reduce post-harvest losses.
A highly sensitive electrochemical immunosensor based on a screen-printed gold
electrode (SPGE) with onboard carbon counter and silver / silver chloride (Ag/AgCl)
pseudo-reference electrode was developed in this work for the detection and
quantification of Botrytis species. The sensor utilised a direct sandwich enzyme-linked
immunosorbent assay (ELISA) format with a monoclonal antibody against Botrytis
immobilised on the gold working electrode. Two immobilisation strategies were
investigated for the capture antibody, and these included adsorption and covalent
immobilisation after self-assembled monolayer formation with 3-dithiodipropionic acid
(DTDPA). A polyclonal antibody conjugated to the electroactive enzyme horseradish
peroxidase (HRP) was then applied for signal generation. Electrochemical
measurements were conducted using 3,3’, 5,5’-tetramethylbenzidine dihydrochloride /
hydrogen peroxide (TMB/H2O2) as the enzyme substrate system at a potential
of -200 mV. The developed biosensor was capable of detecting latent Botrytis infections
24 h post inoculation with a linear range from 150 to 0.05 μg fungal mycelium ml-1 and
a limit of detection (LOD) as low as 16 ng ml-1 for covalent immobilisation and
58 ng ml-1 for adsorption, respectively. Benchmarked against the commercially
available Botrytis ELISA kits, the optimised immuno-electrochemical biosensor showed
strong correlation of the quantified samples (R2=0.998) ... [cont.].
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Alcântara, Segundinho Pedro Gutemberg de [UNESP]. "Análise teórico-experimental de um tabuleiro misto madeira-concreto composto por vigas circulares." Universidade Estadual Paulista (UNESP), 2005. http://hdl.handle.net/11449/91482.
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Made available in DSpace on 2014-06-11T19:25:21Z (GMT). No. of bitstreams: 0
Previous issue date: 2005-02-14Bitstream added on 2014-06-13T19:12:02Z : No. of bitstreams: 1
alcantarasegundinho_pg_me_ilha.pdf: 4485630 bytes, checksum: 0e58733013f71fa0d93bb68c2fdabebb (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
O estudo em estruturas mistas é dedicado ao emprego do material madeira-concreto em estruturas de pontes, mais precisamente no seu tabuleiro. No entanto, a aplicação desse material no Brasil não está regulamentada por normas que permitam ao engenheiro civil fazer sua aplicação nas estruturas correntes. Com a proposta de viabilizar o uso desse material madeira-concreto esse estudo vem contribuir com um melhor entendimento do comportamento físico da ligação entre os materiais madeira e concreto. O estudo dessa ligação foi realizado quantificando o módulo de deslizamento em corpos-de-prova do tipo push-out, vigas T e tabuleiro de madeira-concreto. Os resultados experimentais do módulo de deslizamento obtidos por esses três tipos de ensaios foram comparados com os resultados obtidos teoricamente pelo Eurocode 5 (1993). Também, no seguinte estudo foi feito uma simulação numérica do tabuleiro de madeira-concreto usando um programa para análise estrutural baseado no Método dos Elementos Finitos (MEF). Na conclusão dessa pesquisa verificou-se que o comportamento estrutural desse material misto pode-ser calculado usando o Eurocode 5 (1993) e o Método dos Elementos Finitos (MEF).
The study of mixed structures is dedicated to the use of timber-concrete material in bridges' structures, more precisely in its tray. However, the application of this material in Brazil is not regulated by standards that allow the civil engineer to make its application in the current structures. With the proposal to make possible the use of this timber-concrete material this study contributes to understand better the physical behavior of the linking between wood and concrete. The study of this connection was carried through quantifying the slip's module in specimens of push-out type, T beams and timber-concrete's tray. The experimental results of the slip's module from these three kinds of tests had been compared with the results obtained theoretically for Eurocode 5 (1993). Also, in the following study it was made a mathematical simulation of the wood-concrete's tray using a numerical analysis' program based on the Finite Elements' Method (MEF). In the conclusion of this research it was verified that the structural behavior of this mixed material can to be calculated using Eurocode 5 (1993) and the Method of the Finite Elements (MEF).
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Alexandrou, Ioannis G. "Growth and characterisation of CN films incorporating fullerene-like species." Thesis, University of Liverpool, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.344005.
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Dunkley, Kingsley Delroy. "Modulation of cell yields and genetic responses of Salmonella fermentation and colonization in the gastrointestinal ecology of avian species." [College Station, Tex. : Texas A&M University, 2006. http://hdl.handle.net/1969.1/ETD-TAMU-1187.
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Sumner, Mitch A. "Cross-species comparisons of the retrosplenial cortex in primates: Through time and neuropil space." Kent State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=kent1364987439.
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Samsoedin, Ismayadi. "Biodiversity and sustainability in the Bulungan Research Forest, East Kalimantan, Indonesia : the response of plant species to logging." Thesis, University of Stirling, 2007. http://hdl.handle.net/1893/224.
Full textAbstract:
This study reports forest structure, regeneration and the soil properties from unlogged and logged forest in the Bulungan Research Forest, Malinau District, East Kalimantan, Indonesia. Four sites were compared by using four 1-ha replicate plots in each of primary forest (PF), 5, 10 and 30-yr old logged forest (LF-5, LF-10, LF- 30). The tree species composition differ among forest types, as it was shown that the mean value of similarity indices for all pairs were 0.215 (for the Jaccard index) and 0.353 (for the Sorensen index). The low values for similarities among forest types were most probably caused by low numbers of species shared between each forest type. Both correlation values, r = 0.023 for Jaccard index and r = 0.031 for Sorensen index, showed no strong correlation between the similarity index (C) and the distance between forest types. This supports the use of a chronosequence approach. A total of 914 tree species with ³ 10 cm dbh were recorded from 223 genera and 65 families. There were no significant differences in mean species numbers (166 – 180/ha) among treatments. Mean density of species was lower in LF-5 and LF-10 (501/ha) than in PF or LF-30 (605/ha and 577/ha); similarly to mean basal area (LF-5, 28.5 m2/ha; LF-10, 32.6 m2/ha) vs. PF (45.8 m2/ha) and LF-30 (46.9 m2/ha). Dead wood on the forest floor was significantly higher in LF-10 (75 m3/ha) than in the other treatments. Seedlings (< 2 cm dbh) of 1,022 species were recorded from 408 genera and 111 families. The mean number of tree seedling species ranged between 170-206; the mean density of seedlings was about two-fold lower in LF-10 (2790/ha) than in the other treatments. Saplings (>2 – 9.9 cm dbh) of 802 species belonged to 241 genera and 65 families. There was a high variability in species richness across treatments (89 – 191/ha), but not in stem numbers. The Dipterocarpaceae family was dominant in all treatments, followed by the Euphorbiaceae. The soils were acidic, low in nutrients and had low to very low fertility. Both primary and logged forest areas are marginal or not suitable for sustained production of plantation crops. Logging caused soil compaction in LF-30. Although in terms of number of species and trees, amount of BA, number of saplings and seedlings LF-30 appeared to have satisfied prescriptions for a second harvest, ecologically the forest is far from mature. The Indonesian Selective Cutting and Replanting (TPTI) system may need to be revised to a 35 – 45 year cycle to ensure long-term forest productivity in terms of not only timber but other goods and ecosystem services, the value of which are never quantified in monetary terms, but can be higher than the timber revenue.
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Thorson, James Turner. "Multi-Species Models of Time-Varying Catchability in the U.S. Gulf of Mexico." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/32662.
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The catchability coefficient is used in most marine stock assessment models, and is usually assumed to be stationary and density-independent. However, recent research has shown that these assumptions are violated in most fisheries. Violation of these assumptions will cause underestimation of stock declines or recoveries, leading to inappropriate management policies. This project assesses the soundness of stationarity and density independence assumptions using multi-species data for seven stocks and four gears in the U.S. Gulf of Mexico. This study also develops a multi-species methodology to compensate for failures of either assumption.
To evaluate catchability assumptions, abundance-at-age was reconstructed and compared with catch-per-unit-effort data in the Gulf. Mixed-effects, Monte Carlo, and bootstrap analyses were applied to estimate time-varying catchability parameters. Gulf data showed large and significant density dependence (0.71, s.e. 0.07, p<0.001) and increasing trends in catchability (2.0% annually compounding, s.e. 0.6%, p < 0.001).
Simulation modeling was also used to evaluate the accuracy and precision of seven different single-species and multi-species estimation procedures. Imputing estimates from similar species provided accurate estimates of catchability parameters. Multi-species estimates also improved catchability estimation when compared with the current assumptions of density independence and stationarity.
This study shows that multi-species data in the Gulf of Mexico have sufficient quantity and quality to accurately estimate catchability model parameters. This study also emphasizes the importance of estimating density-dependent and density-independent factors simultaneously. Finally, this study shows that multi-species imputation of catchability estimates decreases errors compared with current assumptions, when applied to single-species stock assessment data.Master of Science
39
Dixon, Thomas S. "Problems for presentism the inconsistency of presentism with the special theory of relativity /." Laramie, Wyo. : University of Wyoming, 2008. http://proquest.umi.com/pqdweb?did=1594478181&sid=2&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Alcântara, Segundinho Pedro Gutemberg de. "Análise teórico-experimental de um tabuleiro misto madeira-concreto composto por vigas circulares /." Ilha Solteira : [s.n.], 2005. http://hdl.handle.net/11449/91482.
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Orientador: José Antônio MatthiesenBanca: Renato Bertolino Junior
Banca: Antonio Alves Dias
Resumo: O estudo em estruturas mistas é dedicado ao emprego do material madeira-concreto em estruturas de pontes, mais precisamente no seu tabuleiro. No entanto, a aplicação desse material no Brasil não está regulamentada por normas que permitam ao engenheiro civil fazer sua aplicação nas estruturas correntes. Com a proposta de viabilizar o uso desse material madeira-concreto esse estudo vem contribuir com um melhor entendimento do comportamento físico da ligação entre os materiais madeira e concreto. O estudo dessa ligação foi realizado quantificando o módulo de deslizamento em corpos-de-prova do tipo "push-out", vigas T e tabuleiro de madeira-concreto. Os resultados experimentais do módulo de deslizamento obtidos por esses três tipos de ensaios foram comparados com os resultados obtidos teoricamente pelo Eurocode 5 (1993). Também, no seguinte estudo foi feito uma simulação numérica do tabuleiro de madeira-concreto usando um programa para análise estrutural baseado no Método dos Elementos Finitos (MEF). Na conclusão dessa pesquisa verificou-se que o comportamento estrutural desse material misto pode-ser calculado usando o Eurocode 5 (1993) e o Método dos Elementos Finitos (MEF).
Abstract: The study of mixed structures is dedicated to the use of timber-concrete material in bridges' structures, more precisely in its tray. However, the application of this material in Brazil is not regulated by standards that allow the civil engineer to make its application in the current structures. With the proposal to make possible the use of this timber-concrete material this study contributes to understand better the physical behavior of the linking between wood and concrete. The study of this connection was carried through quantifying the slip's module in specimens of "push-out" type, T beams and timber-concrete's tray. The experimental results of the slip's module from these three kinds of tests had been compared with the results obtained theoretically for Eurocode 5 (1993). Also, in the following study it was made a mathematical simulation of the wood-concrete's tray using a numerical analysis' program based on the Finite Elements' Method (MEF). In the conclusion of this research it was verified that the structural behavior of this mixed material can to be calculated using Eurocode 5 (1993) and the Method of the Finite Elements (MEF).
Mestre
41
Hutter, Carl R., Shea M. Lambert, and John J. Wiens. "Rapid Diversification and Time Explain Amphibian Richness at Different Scales in the Tropical Andes, Earth’s Most Biodiverse Hotspot." UNIV CHICAGO PRESS, 2017. http://hdl.handle.net/10150/626254.
Full textAbstract:
The Tropical Andes make up Earth's most species-rich biodiversity hotspot for both animals and plants. Nevertheless, the ecological and evolutionary processes underlying this extraordinary richness remain uncertain. Here, we examine the processes that generate high richness in the Tropical Andes relative to other regions in South America and across different elevations within the Andes, using frogs as a model system. We combine distributional data, a newly generated time-calibrated phylogeny for 2,318 frog species, and phylogenetic comparative methods to test the relative importance of diversification rates and colonization times for explaining Andean diversity at different scales. At larger scales (among regions and families), we find that faster diversification rates in Andean clades most likely explain high Andean richness. In contrast, at smaller temporal and spatial scales (within family-level clades within the Andes), diversification rates rarely explain richness patterns. Instead, we show that colonization times are important for shaping elevational richness patterns within the Andes, with more species found in habitats colonized earlier. We suggest that these scale-dependent patterns might apply to many other richness gradients. Recognition of this scale dependence may help to reconcile conflicting results among studies of richness patterns across habitats, regions, and organisms.
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Vundavalli, Suveen Kumar, and Sri Rama Srinivasa Varma Danthuluri. "Bird Chirps Annotation UsingTime-Frequency Domain Analysis." Thesis, Blekinge Tekniska Högskola, Institutionen för tillämpad signalbehandling, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-13624.
Full textAbstract:
There are around 10,426 bird species around the world. Recognizing the bird species for an untrained person is almost impossible either by watching or listening them. In order to identify the bird species from their sounds, there is a need for an application that can detect the bird species from its sound. Time-frequency domain analysis techniques are used to implement the application. We implemented two time-frequency domain feature extraction methods. In feature extraction, a signature matrix which consist of extracted features is created for bird sound signals. A database of signature matrix is created with bird chirps extracted features. We implemented two feature classification methods. They are auto-correlation feature classification method and reference difference feature classification method. An unknown bird chirp is compared with the database to detect the species name. The main aim of the research is to implement the time-frequency domain feature extraction method, create a signature matrix database, implement two feature classification methods and compare them. At last, bird species were identified in the research and the auto-correlation classification method detects the bird species better than the reference difference classification method.
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Aigbavbiere, Ernest. "How does predation from fish influence the benthic invertebrates’ species composition in the Phragmites australis and Chara vegetation of Lake Takern?" Thesis, Linköpings universitet, Ekologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-72643.
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Predation is one of the important selective factors that regulate the species composition of benthic invertebrate communities. The study objective was to investigate the invertebrate distribution in two contrasting habitats in Lake Takern, southern Sweden, submerged Chara vegetation and emergent Phragmites australis vegetation, and to investigate the influence of predation from fish on certain invertebrates. Laboratory studies were used to estimate handling time and the intake rate (mg/sec) by the fish based on the optimal foraging model. In the field, fish and invertebrates were collected with gill nets and hand nets respectively and the fish gut content was analyzed. In total, sixteen invertebrates’ taxa were collected from the two habitats. The proportion of the invertebrate’s overlaps from each of the habitat was calculated by Renkonen index and with Sorensen diversity index. Both indices showed a similarity larger than 65%, indicating that there was no significant difference in the invertebrates’ distribution in the P. australis and the Chara habitat. The fish caught with the gill nets were: roach (Rutilus rutilus), perch (Perca fluviatilis), tench (Tinca tinca), and rudd (Scardinius erythrophthalmus). The caught perch had eaten: Asellus aquaticus, Gammarus lacustris, Corixidae, and the larvae of Chironomidae and Zygoptera.A comparison was made on the invertebrates found in the field and the ones observed from the gut of the perch, and the findings were that the invertebrates that had more occurrence in the gut were less in proportion in the benthic samples. In the laboratory experiment perch ( Perca fluviatilis) was used as the predator fish and the prey organisms were Asellus aquaticus,Gammarus pulex, and Corixidae of three size categories. The results showed that perch handling time for A.aquaticus of the different size categories, was not significantly different (p>0.05); and the same results were valid for Corixidae and G. pulex. However, the intake rate of perch across the prey and their size categories were significantly different. The handling time was not significantly different which means that the predator fish will gain more in terms of intake rate as it prey on larger size prey items, thus harmonizing with the optimum foraging theory.MSc Ecology and Environmental Science
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Chung, Sunjung. "Effect of Poor Sanitation Procedures on Cross-Contamination of Animal Species in Ground Meat Products." Chapman University Digital Commons, 2019. https://digitalcommons.chapman.edu/food_science_theses/3.
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While the presence of ≥1% of an undeclared species in ground meat generally used as an indicator of intentional mislabeling as opposed to cross-contamination, the actual percent of undeclared species resulting from cross-contamination has not been experimentally determined. The objective of this study was to quantify the effect of sanitation procedures on the crosscontamination of animal species in ground meat products, using undeclared pork in ground beef. Pork (13.6 kg) was processed using a commercial grinder, then one of three sanitation treatments was completed (“no cleaning”, “partial cleaning”, or “complete cleaning”). Next, beef (13.6 kg) was ground using the same equipment. For “no cleaning,” beef was ground immediately after pork without any cleaning step; for “partial cleaning,” the hopper tray was wiped, and excess meat was taken out from the auger; for “complete cleaning,” all parts of the grinder were disassembled and thoroughly cleaned with water and soap. A 100-g sample was collected for each 0.91 kg (2 lb) of beef processed with the grinder and each sanitation treatment was tested twice. Real-time polymerase chain reaction (PCR) was used to quantify pork in ground beef. For “no cleaning,” the first 100-g sample of ground beef run through the grinder contained 24.42 ± 10.41% pork, while subsequent samples contained
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Köchy, Martin, and Katja Tielbörger. "Hydrothermal time model of germination : parameters for 36 Mediterranean annual species based on a simplified approach." Universität Potsdam, 2006. http://opus.kobv.de/ubp/volltexte/2007/1240/.
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Germination rates and germination fractions of seeds can be predicted well by the hydrothermal time (HTT) model. Its four parameters hydrothermal time, minimum soil temperature, minimum soil moisture, and variation of minimum soil moisture, however, must be determined by lengthy germination experiments at combinations of several levels of soil temperature and moisture. For some applications of the HTT model it is more important to have approximate estimates for many species rather than exact values for only a few species. We suggest that minimum temperature and variation of minimum moisture can be estimated from literature data and expert knowledge. This allows to derive hydrothermal time and minimum moisture from existing data from germination experiments with one level of temperature and moisture. We applied our approach to a germination experiment comparing germination fractions of wild annual species along an aridity gradient in Israel. Using this simplified approach we estimated hydrothermal time and minimum moisture of 36 species. Comparison with exact data for three species shows that our method is a simple but effective method for obtaining parameters for the HTT model. Hydrothermal time and minimum moisture supposedly indicate climate related germination strategies. We tested whether these two parameters varied with the climate at the site where the seeds had been collected. We found no consistent variation with climate across species, suggesting that variation is more strongly controlled by site-specific factors.Keimungsgeschwindigkeit und Anteil gekeimter Samen lassen sich gut mit dem Hydrothermalzeit-Modell bestimmen. Dessen vier Parameter Hydrothermalzeit, Mindesttemperatur, Mindestbodenfeuchte und Streuung der Mindestbodenfeuchte müssen jedoch durch aufwendige Keimungsversuche bei Kombinationen von mehreren Temperatur- und Feuchtigkeitsstufen bestimmt werden. Für manche Anwendungen des Hydrothermalzeit-Modells sind aber ungefähre Werte für viele Arten wichtiger als genaue Werte für wenige Arten. Wenn die Mindesttemperatur und die Streuung der Mindestfeuchte aus Veröffentlichungen und Expertenwissen geschätzt würde, können die Hydrothermalzeit und Mindestbodenfeuchte aus vorhandenen Daten von Keimungsversuchen mit nur einer Temperatur- und Feuchtigkeitsstufe berechnet werden. Wir haben unseren Ansatz auf einen Keimungsversuch zum Vergleich der Keimungsquote wilder einjähriger Arten entlang eines Trockenheitsgradienten in Israel angewendet. Mit diesem Ansatz bestimmten wir die Hydrothermalzeit und Mindestfeuchtigkeit von 36 Arten. Der Vergleich mit genauen Werten für drei Arten zeigt, dass mit unserem Ansatz Hydrothermalzeit-Parameter einfach und effektiv bestimmt werden können. Hydrothermalzeit und Mindestfeuchtigkeit sollten auch bestimmte klimabedingte Keimungsstrategien anzeigen. Deshalb testeten wir, ob diese zwei Parameter mit dem Klima am Ursprungsort der Samen zusammenhängen. Wir fanden jedoch keinen für alle Arten übereinstimmenden Zusammenhang, so dass die Unterschiede vermutlich stärker durch standörtliche als durch klimatische Ursachen hervorgerufen werden.
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Schwartz, Jean-Luc. "Représentations auditives de spectres vocaliques." Grenoble INPG, 1987. http://www.theses.fr/1987INPG0086.
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Ce travail se compose en trois parties. La premiere partie est consacree aux techniques d'estimation par masquage des caracteristiques quantitatives des representations auditives "peripheriques". La deuxieme partie traite de l'etude des traitements auditifs des spectres vocaliques. Dans la troisieme partie les auteurs abordent l'etude des systemes vocaliques en proposant ce que pourrait etre une "theorie des formes et de la stabilite" a la lumiere de la theorie de l'integration spectrale e large bande, avec les concepts de stabilite intrinseques et extrinseques, et en essayant d'inscrire cette theorie dans un systeme general des systemes vocaliques
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Wu, Andrew. "Can Spiders (Argiope Aurantia) Indirectly Affect the Fitness of Orange Coneflowers (Rudbeckia Fulgida) by Limiting Pollinator Visitation?" University of Akron / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=akron1343307113.
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Fair, Joseph Edward. "Infant Facial Discrimination and Perceptual Narrowing." BYU ScholarsArchive, 2009. https://scholarsarchive.byu.edu/etd/2154.
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During the early stages of infant development the capacity for perceptual (i.e., visual) discrimination is shaped by infants' perceptual experience. Perceptual narrowing is one process hypothesized to account for developmental change. Perceptual narrowing research often demonstrates that infants before 6 months of age are able to discriminate a wide variety of events whereas infants beyond 6 months of age seemingly "lose" some perceptual abilities. Two investigations are proposed to examine the claim that younger, but not older infants can discriminate faces across species. The purpose of Experiment 1 was to determine whether an increase in familiarization and trial times would result in cross-species facial (i.e. faces of macaques) discrimination in 12-month-olds. The hypothesis was supported, adding evidence that perceptual discrimination becomes more constricted, or less efficient with age, but does not decline. Experiment 2 examined whether reducing both the time of familiarization and comparison time by 50% would allow infants sufficient time to discriminate. Results were consistent with the hypothesis and previous studies were corroborated. These findings highlight the important role of perceptual experience in young infants' perceptual discrimination abilities and provide a greater degree of clarity regarding present use of the concept perceptual narrowing.
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Kim, Ji Sun. "CULTIVABLE FUSOBACTERIUM SPECIES IN CHRONIC PERIODONTITIS MICROBIOTA IDENTIFIED WITH MATRIX-ASSISTED LASER DESORPTION/IONIZATION TIME-OF-FLIGHT MASS SPECTROMETRY." Master's thesis, Temple University Libraries, 2015. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/318875.
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Oral BiologyM.S.
Objectives: Fusobacteria are prominent participants in the maturation of subgingival dental plaque biofilms in humans. A number of various species belonging to the Fusobacterium genus have been recovered from the subgingival microbiota of chronic periodontitis patients. However, conventional Fusobacterium species identification is labor-intensive, time-consuming, and complicated by shortcomings in phenotypic-based classification schemes, where many fusobacteria display overlapping and non-distinguishing morphologic features and biochemical properties. In addition, molecular identification of fusobacteria is plagued with difficulties of validating the specificity of nucleic acid probes and primers to various Fusobacterium species that have closely-related interspecies genetic profiles. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, and its associated analytic software, was recently approved for clinical microbiology diagnostic use by the United States Food and Drug Administration. MALDI-TOF mass spectrometry has the potential to rapidly identify cultivable clinical isolates to a species level for 4,613 different bacterial species based on mass spectra of their bacterial protein profiles, including many Fusobacterium species. The purpose of this study was to use MALDI-TOF mass spectrometry to rapidly identify the patient distribution of fusobacteria isolated from the subgingival microbiota of chronic periodontitis patients. Methods: A total of 34 chronic periodontitis patients provided 96 fresh subgingival cultivable fusobacteria isolates (one to seven isolates per patient), which were presumptively identified by their chartreuse-positive colony autofluorescence under long-wave ultraviolet light on anaerobically-incubated, non-selective, enriched Brucella blood agar primary isolation plates. Each of the presumptive fusobacteria clinical isolates were subjected to MALDI-TOF mass spectrometry analysis using a bench top mass spectrometer, Bruker FlexControl 3.0 software, and MALDI Biotyper 3.1 software (Bruker Daltonics, Billerica, MA, USA), which contains mass spectra for a variety of fusobacteria in its reference library of bacterial protein profiles. Each clinical isolate underwent on-target plate formic acid protein extraction, and was taxonomically classified with MALDI-TOF mass spectrometry within an approximately 30-45 minute time period from the point of colony harvesting from primary isolation culture plates. A MALDI Biotyper log score of equal to or larger than 1.7 was required for reliable taxonomic classification of the clinical fusobacteria isolates. Results: A majority (58.8%) of the chronic periodontitis patients yielded two or three different species of subgingival Fusobacterium on non-selective enriched Brucella blood agar primary isolation plates. Fusobacterium naviforme was identified by MALDI-TOF mass spectrometry analysis in 14 (41.2%) chronic periodontitis study patients, Fusobacterium nucleatum subspecies vincentii in 13 (38.2%) patients, Fusobacterium nucleatum subspecies polymorphum in 9 (26.5%) patients, Fusobacterium nucleatum and Fusobacterium species each in 6 (17.6%) patients, Fusobacterium nucleatum subspecies nucleatum in 4 (11.8%) patients, and Fusobacterium nucleatum subspecies animalis in 3 (8.8%) patients. Three patients additionally yielded subgingival isolates of Fusobacterium canifelinum, normally an inhabitant of the oral cavity of dogs and cats. 52 (54.2%) of the fusobacteria clinical isolates revealed MALDI Biotyper log scores of equal to or larger than 1.7, the threshold for reliable taxonomic classification, while in comparison, 44 (45.8%) had log scores less than 1.7, indicating a less reliable species identification. No other microbial species, other than one of the Fusobacterium species, was listed by the MALDI-TOF mass spectrometry analytic software as the most likely organism for the tested clinical isolates. Conclusions: These findings indicate that a variety of Fusobacterium species may be identified with MALDI-TOF mass spectrometry in the subgingival microbiota of chronic periodontitis patients. F. naviforme and F. nucleatum subspecies vincentii were the most frequently isolated subgingival fusobacteria species in the evaluated study patients. Three chronic periodontitis patients also unexpectedly revealed subgingival isolates of the animal species F. canifelinum, which is normally in the oral cavity of dogs and cats. MALDI-TOF mass spectrometry may facilitate rapid identification of cultivable fusobacteria in human subgingival dental plaque biofilms, and enhance understanding of bacterial community structure in periodontal pockets.
Temple University--Theses
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Macintyre, Alasdair. "Spectres in the studio : Time, memory and the artist's haunted imagination." Phd thesis, Australian Catholic University, 2022. https://acuresearchbank.acu.edu.au/download/1b352559bf33109aaf78ce86abeb5bbbbbd754c375b9b3ec71fb778bd891fb4e/16278474/Macintyre_2022_Spectres_in_the_studio_time_memory.pdf.
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I spent a week in a haunted house and that is what inspired this project. I then discovered hauntology. Hauntology is a concept that was developed by French philosopher Jacques Derrida and articulated in his 1993 lecture Specters of Marx. Hauntology is a theory reliant on time, where the historical past and the envisaged future bleed in to the present moment. A concept that recognises the ghosts of the past that are bound to return again and again to haunt the mind, as well as spectres that represent expectant futures that did not eventuate. While hauntology (also known as spectral studies) has been used as a thematic device in the fields of music and literature as both a creative and a critical tool, it has not been utilised to the same degree in the visual arts. This PhD by creative project aims to correct that by using hauntology as a framework through which to explore my own visual art practice. To do this I have made a body of work that reflects my own life experience and memories as read through a hauntological sensibility. By beginning with an overview of hauntology and then reflecting on the recursive nature of memory evidenced throughout my previous artworks, I suggest in this thesis that hauntology is an interesting and revealing framework through which to better understand the nature of both my art practice and contemporary art practice in general.
In my discussion, I examine the parallel themes of memory and collapsed time, as well as motifs such as the ‘white-sheet ghost’ and abandoned domestic spaces. Inspired by this research, I have created a body of work using hauntology as my visual framework, exploring my own haunted memories and moments in time from my own past (that I have never attempted to do previously). One of my aims was to address certain incidents and moments from my own life that have stayed with me, and how my haunted imagination can inform my art practice. The creation of artworks about these past events neither dulls nor exorcises the memories but allows the artist to better comprehend the range and depth of human experience and the way it contributes to, haunts, our subjectivity both in the present and, probably, in the future. The final body of work was exhibited on the Australian Catholic University campus in Brisbane to complete this project.