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Title: Acoustic and adsorption properties of submerged wood.
Contributors: Calvin Patrick Hilde (author), Ian Hartley (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: Wood is a common material for the manufacture of many products. Submerged wood, in particular, is used in niche markets, such as the creation of musical instruments. An initial study performed on submerged wood from Ootsa Lake, British Columbia, provided results that showed that the wood was not suitable for musical instruments. This thesis re-examined the submerged wood samples. After allowing the wood to age unabated in a laboratory setting, the wood was retested under the hypothesis that the physical acoustic characteristics would improve. It was shown, however, that the acoustic properties became less adequate after being left to sit. The adsorption properties of the submerged wood were examined to show that the submerged wood had a larger accessible area of wood than that of control wood samples. This implied a lower amount of crystalline area within the submerged wood. From the combined adsorption and acoustic data for the submerged wood, relationships between the moisture content and speed of sound were created and combined with previous research to create a proposed model to describe how the speed of sound varies with temperature, moisture content and the moisture content corresponding to complete hydration of sorption sites within the wood. --P. ii.
Discipline: Physics
Date added: 2017-03-30T17:10:33.941Z

Title: Adoption of wood pellets in the Prince George, BC market: perceptions and opportunities
Contributors: Mark Dunsford (author), Ian Hartley (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: No abstract available.
Discipline: Business Administration
Date added: 2017-04-10T22:15:57.554Z

Title: Arsenic adsorption in aqueous solution and immobilization in soils and using hand warmers
Contributors: Zeyi Tong (author), Ian Hartley (Thesis advisor), Todd Whitcombe (Thesis advisor), Hualin Chen (Thesis advisor), University of Northern British Columbia College of Science and Management (Degree granting institution), Michael Rutherford (Committee member), William McGill (Committee member), Yubao Li (Committee member)
Abstract: Adsorption is a commonly used method for arsenic remediation. The adsorption and immobilization effectiveness of arsenic by soil particles and used hand warmers was studied. The adsorption effectiveness at equilibrium of soil particles in 10 ppm As(III) solution was: clay (77.70%) > silt (69.24%) > sand (41.35%). In 1000 ppm As(III) solution, 17.02 mg As(III) was adsorbed onto each gram of hand warmers at equilibrium, which was significantly higher than other adsorbents. For As(III) adsorption from aqueous solution, soil samples and hand warmers were well fitted to the pseudo secondorder model and the Freundlich model. After 8 weeks of soil incubation, the sequential extraction procedure data indicated the labile fractions of arsenic (F1 and F2) decreased with the addition of hand warmers. Meanwhile, the percentage of the most stable fraction, F5, increased. These results are valuable for the future application of used hand warmers as an adsorbent/amendment for arsenic decontamination.
Discipline: NRES-Environmental Science
Date added: 2017-05-15T21:06:46.774Z

Title: Cost analysis of a forest seedling planting machine: a case study for BC
Contributors: Geoffrey Graham Clarke (author), Ian Hartley (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: The Province of British Columbia forest tenure licensing practices require the replanting of tree seedlings in the place of logged forest. Reforestation is presently done manually by individual tree planters. Currently there is a shortage of skilled tree planting labour in Western Canada. This shortage will be exacerbated as the millions of hectares of dead lodgepole pine forests in British Columbia's Central Interior continue to be harvested in the wake of the mountain pine beetle epidemic. Mechanized planting provides a possible solution to this problem. This method has been applied successfully in the agriculture sector and attempted in forestry. Presently in Western Canada no commercially viable automated reforestation is taking place. Research into mechanized conifer transplanting techniques introduced thus far show low productivity and high operating expenses. This paper investigates current manual and automated planting methods for seedling planting quality, growth rates and transplanting costs. In order to contribute to design criteria and assess the commercial prospects of mechanized reforestation equipment in British Columbia's Central Interior, estimates of a machine's minimum planting rate, crew size and equipment configuration will be made. From these specification an initial capital investment in equipment is forecast and projections of operating costs determined. --P. ii.
Discipline: Business Administration
Date added: 2017-04-10T22:07:26.65Z

Title: Determination of density and moisture content of wood using Terahertz time domain spectroscopy.
Contributors: Belal Ahmed (author), Ian Hartley (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: Terahertz time-domain spectroscopy was used to simultaneously predict the density and moisture content of four wood species (Aspen, Birch, Hemlock and Fir). Using a fixed value for the dielectric function of water, it was found that moisture content was systematically underestimated at low moisture contents, which results from changes in the dielectric function of water as it goes from free to bound in nature. The variation of the dielectric function of water with moisture content was studied further, and the results show that the dielectric function of water does indeed change with moisture content. The results are a large step forward in our understanding of wood-water interactions at Terahertz frequencies, and therefore useful for applications in wood science. --Leaf i.
Discipline: Physics
Date added: 2017-04-11T21:13:11.575Z

Title: Determination of the origin of birefringence in wood at terahertz frequencies.
Contributors: Tara Marie Todoruk (author), Matthew Reid (Thesis advisor), Ian Hartley (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: In the wood products industry, terahertz (THz) radiation is an emerging technology that is showing promise for new types of monitoring. These applications are dependent on the ability of THz radiation to probe the gross fibre structure of wood. The sensitivity to this gross fibre structure results from strong birefringence at THz frequencies. Prior to this thesis work, the nature of the birefringence exhibited in wood was an open question. Based on the physical structure of wood, the large birefringence observed can be due to intrinsic birefringence, resulting from the dielectric properties of the wood material present in the cell walls, or form birefringence, resulting from the repetitive array of cylindrical cells present in the wood structure. This thesis determines for the first time the origin of birefringence at THz frequencies in wood. This question is important to potential applications in the wood products industries because if the birefringence has a large contribution from form birefringence, then it is the gross fibre structure of wood products that is being probed by THz radiation, which opens the door to applications in non-contact, non-destructing strength testing for example. This thesis outlines a number of systematic studies that will address the relative contributions of form and intrinsic birefringence to the large birefringence seen in wood at THz frequencies, and demonstrate, for the first time, what the source of this large birefringence is in several different species of wood. --P. ii.
Discipline: Physics
Date added: 2017-03-30T17:05:14.832Z

Title: Evaluating lodgepole pine (Pinus contorta) affected by mountain pine beetle (Dendroctonus ponderosae) for development of wood-cement board.
Contributors: Sorin Andrei Pasca (author), Ian Hartley (Thesis advisor), Ron Thring (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: Assessing the shelf life of wood from mountain pine beetle (Dendroctonus pondersoa [Hopkins]) killed lodgepole pine (Pinus contorta var. latifolia) in terms of its compatibility for Portland cement was examined. Two methods of assessment were used, based on the behavior of the exothermic chemical reaction of cement hydration, accounting for the difference between neat cement paste and wood-cement mixtures. A new wood-cement compatibility index meant to integrate current approaches was defined. No evidence was found of limitations in terms of beetle-killed heartwood wood compatibility with cement except for the white rot infested samples. An outstanding physicochemical behavior characterized the mixtures of blue-stained sapwood and cement. Three compositions of ingredients were proposed for fabricating wood-cement boards that would meet the technical specifications given by the gypsum board standards with respect to strength and stiffness. In absence of pressing, the water was the factor used to regulate workability during the molding process.--P.ii.
Discipline: Environmental Science
Date added: 2017-03-30T17:03:11.32Z

Title: Exploring a child's developmental diagnosis: an interpretive description of parents' experiences in northern British Columbia
Contributors: Tammy Pearson (author), Ian Hartley (Thesis advisor), Shannon Wagner (Thesis advisor), Glen Schmidt (Thesis advisor), University of Northern British Columbia College of Arts, Social, and Health Sciences (Degree granting institution), Gerard Bellefeuille (Committee member), Margo Greenwood (Committee member), Angelo Valeo (Committee member)
Abstract: Background: Full parental understanding of a child’s diagnosis of a developmental disability is critical to be able to ensure the best health outcome for their child. Yet factors that parents perceive as influencing their comprehension during the final diagnostic meeting have not been well identified. Method: As part of a qualitative study using interpretive description, 17 parents were interviewed on the basis of their having been referred to, and for having received a child’s developmental diagnosis from a Complex Developmental Behavioural multidisciplinary team located in northern British Columbia. Semi-structured interviews focused on the factors that played a role in facilitating or impeding the parents’ understanding of their child’s diagnosis, and on the identification of factors that influenced the way in which the child’s clinical recommendations were pursued. The interviews were recorded and transcribed. Data analysis was informed by Braun and Clarke’s six phases of thematic analysis. Results: Three overarching themes with twelve subthemes emerged from parents’ reported experiences of receiving their child’s developmental diagnosis. The three overarching themes and twelve subthemes included (a) clinical encounter (including the subthemes structural considerations, professional diversity and new insights, questions regarding the assessment process, validation, and expectations); (b) the manner of the delivery of the diagnosis (impact—emotional and impact on parenting practices, professionalism, professional language, and quantity of information); (c) Where do we go from here? (post disclosure, the final evaluation report, and recommendations). The parents’ accounts established and clarified the positive and negative parental determinants that aided or challenged their ability to understand their child’s developmental diagnosis and identified the influence this had when it came to implementing the clinical recommendations. ...
Discipline: Health Sciences
Date added: 2017-05-15T21:10:44.539Z

Title: Feasibility study: utilization of wood pellets as an institutional heat energy source at the University of Northern British Columbia
Contributors: Steven Storch (author), Alex Ng (Thesis advisor), Ian Hartley (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: The three main factors that underpin the project study were: 1) Biofuels and alternative energy are becoming more important parts of the British Columbia energy matrix. 2) In central BC, the mountain pine beetle infestation has led to increased harvesting opportunities for lumber, pulp and paper and wood pellet producing companies. 3) In 2007, the University of Northern British Columbia branded itself as the Green University and introduced six green objectives as part of the process. It was from the intersection of these three facts that an investigation was undertaken to determine the feasibility of utilizing wood pellet derived heat energy for campus heating and cooling. The first part of this paper was to review and document the existing heating system at UNBC and review the options for selecting, funding, installing and operating a wood pellet biomass system in parallel with the existing natural gas campus heating system. The second part of the paper was an attempt to calculate the approximate cost of a wood pellet biomass energy system suitably sized to fulfill the base load heat requirements of the Prince George UNBC campus. Interviews were conducted with key university personnel, industry and regulatory bodies to ascertain costs. Costs and estimates were then calculated with Natural Resources Canada's RETScreen International Clean Energy Support software and Excel spreadsheets to determine the financial viability of such a project. The analyses showed that wood pellet heat energy is financially feasible as an alternative energy source at UNBC.
Discipline: Business Administration
Date added: 2017-04-10T22:11:18.611Z

Title: An investigation of natural hybridization between jack pine (Pinus banksiana) and lodgepole pine (Pinus contorta var. latifolia) in northern British Columbia.
Contributors: Lisa Wood (author), Ian Hartley (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: No abstract available.
Discipline: Forestry
Date added: 2017-03-30T17:01:19.756Z

Title: Log quality characteristics of mountain pine beetle killed lodgepole pine trees from southern interior British Columbia for board processing.
Contributors: Benjamin Woodward (author), Ian Hartley (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: The mountain pine beetle (MPB) (Dendroctonus ponderosae Hopkins) epidemic has ravaged lodgepole pine (Pinus contorta var. latifolia) forests throughout British Columbia (BC). The research focused on the effects of three stages of MPB trees, green, red, and grey attack from southern interior BC on the MPB-induced variables of log moisture content (MC), blue stain, and checking and how these relate to log quality from an end product perspective. The objectives were to determine if: 1) the percentage of blue stain calculated from the log end surface at diameter breast height (DBH) correlates to the percentage of blue stained boards 2) the quantity and size of checks present in a disk removed at DBH correlates to the percentage of checked boards 3) the sapwood moisture content from a cross sectional disc at DBH correlates to the percentage of MPB-induced degrades (checking, wood borers, and decay fungi). Three sections of each MPB log (bottom, middle, and top), were examined for the MPB-induced degrades blue stain, checking, and the losses due to wood borers and decay fungi. The results support the findings of previous MPB research where reduced moisture content, blue stain, and checking significantly reduce log quality. However, this study is unique since it relates these findings to the effects that they have on the board products. The percentage of blue stain from a disc cut at DBH is correlated to the percentage of blue stained boards from that tree for green, red, and grey attack. As blue stain increases in the disc cut at DBH by attack stage, the amount of blue stained boards also increases by attack stage. When the check depth is >3 cm and the check depth to width ratio in a disk cut at DBH is >4, there is a positive correlation to the percentage of checked boards for that tree. If the check depth to width ratio is less, these shallow checks are removed by the canter chipping heads during primary breakdown. As MC decreases below the fibre saturation point, there is a linear relationship between MC and MPB-
Discipline: Forestry
Date added: 2017-03-30T17:08:51.613Z

Title: Probing the potential applications of terahertz radiation in wood products
Contributors: Jonathan Michael Schneider (author), Matthew Reid (Thesis advisor), Ian Hartley (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: In the wood products industry, terahertz (THz) radiation is showing promise as a new remote sensing technology with many applications. The purpose of this project was to probe the interaction of terahertz radiation with wood to determine the extent of these possibilities. Three avenues of study were undertaken: 1. Probe the cylindrical structure of wood in a reflection geometry, 2. Study the birefringence of different species of oven dry wood, 3. Study the extinction coefficient of different species of oven dry wood. These three studies increased our understanding of the interaction between THz radiation and wood. Prior to this study, the extinction mechanism in THz transmission through wood was an open question. Three mechanisms were identified: absorption by the vibrational and rotational modes of the wood and water molecules scattering by the dielectric cylindrical wood cells and, diffraction by the earlywood-latewood pattern. This project determined that absorption by the wood and water molecules is the dominant extinction mechanism in transmission through wood, contributing to ~90% of the signal attenuation. --P. i.
Discipline: Physics
Date added: 2017-04-10T22:05:38.763Z