Three studies were undertaken from 2006 to 2007 to examine litter (dead plant material) in southwestern Manitoba pastures. First, the relationship between litter and soil microclimate was tested across five pasture sites. The amount of litter biomass was not strongly related to soil moisture, though near-surface soil temperatures were reduced when litter was present. Second, the effect of four simulated grazing strategies on the litter layer was measured in six pastures. It was found that after three years of simulated grazing, litter was present in largest quantities in the least-frequently grazed treatments. Finally, a field survey was conducted assessing the quantity of litter present in native pastures across Manitoba. Litter was quite variable and averaged 1902 kg/ha over two years. This research confirmed the value of litter as an indicator of sustainable pasture management, though it remains unclear whether litter is important to pastures from the perspective of soil microclimate. / October 2008

Over 2 years (Year 1, 2009-2010; Year 2, 2010-2011), two separate experiments were conducted to evaluate the effects of winter feeding system (n=3) on beef cow performance, reproductive performance, economics and forage degradability. The three systems (treatments) were grazing pea crop residue (PEA) cv. ‘Performance 40-10’ (Year 1, TDN = 50.2%, CP = 7.3%; Year 2, TDN = 56.9%, CP = 8.9%) in field paddocks, grazing oat crop residue (OAT) cv. ‘Baler’ (Year 1, TDN = 59.1%, CP = 2.9%; Year 2, TDN = 66.9%, CP = 5.3%) in field paddocks, and feeding mixed grass-legume hay in drylot pens (DL) (Year 1, TDN = 61.4%; CP = 8.8%; Year 2, TDN = 52.3%, CP = 12.3%). In the first experiment, 90 dry, pregnant Black Angus cows (Year 1, 629 kg ± 74 kg; Year 2, 665 ± 69 kg) stratified by body weight (BW) and days pregnant were randomly allocated to 1 of the 3 systems. Cows were allocated feed in the field or pen on a 3 d basis and supplemented oat grain daily at 0.4-0.6% BW depending on environmental conditions. Dry matter intake (DMI) was estimated for each system using the herbage weight disappearance method. Cow BW, body condition score (BCS), and rib and rump fat were measured at start and end of trial and cow BW was corrected for conceptus gain based on calving data. When data from the first 20 d were pooled over 2 years, initial cow BW was greater (P < 0.01) for the DL and OAT cows compared to the PEA cows and final cow BW was different (P < 0.01) between all 3 winter feeding systems. The change in BW was also greater (P < 0.01) for DL cows compared to cows on the OAT and PEA treatments. Analysis of the first 20 d of Year 1 study period and the total Year 2 study period, showed a significant (P < 0.01) year by treatment interaction for final BW and BW change. The differences (P < 0.01) in initial BW, final BW and BW change between the first 20 d of Year 1 study period and the total Year 2 study period (20 d) suggest feed quality, animal preference and weather conditions may cause difficulties when grazing residues in winter grazing systems. Analysis of the entire trial period in Year 1 (62 d) indicates differences (P < 0.01) for final BW and BW change between cows on all three systems. The change in rib and rump fat was also different (P < 0.01) between cows in all 3 systems. In Year 2 (20 d), initial BW, final BW and BW change were different (P < 0.01) between DL and PEA cows, and between (P < 0.01) OAT and PEA cows. No difference (P > 0.05) was found for cow rib and rump fat in Year 2 and no difference (P > 0.05) was found for BCS in either Year 1 or Year 2 for cows managed in all 3 systems. Differences (P < 0.05) were observed for calving rate and calf birth weight between the DL and OAT system cows, but not between (P > 0.05) cows managed in the DL and PEA or OAT and PEA systems. Costs per cow per day were $1.22, $1.01 and $2.77 for PEA, OAT and DL systems in Year 1, respectively. In Year 2, cow costs per day were $1.59, $1.44 and $1.84 for PEA, OAT and DL systems, respectively. In experiment 2, three ruminally cannulated, dry Holstein cows were fed a silage based total mixed ration (TMR) of 22 kg barley silage, 7 kg chopped alfalfa hay and 1 kg energy supplement (DAC-485). In-situ degradability was studied to determine the extent of degradation of pea, oat and grass-legume hay collected at start (SOT) and end of test (EOT) in experiment one. Rate of degradation (Kd) of DM was greater (P < 0.01) for PEA EOT compared to HAY, OAT SOT and OAT EOT. Dry matter rate of degradation for PEA SOT was greater (P < 0.05) compared to OAT SOT and OAT EOT. The effectively degradable fraction of CP was greater (P = 0.03) for HAY compared to PEA EOT. The ruminally undegradable fraction of CP was greater (P = 0.03) for PEA EOT compared to HAY. Acid detergent fiber rate of degradation (Kd) was greater (P = 0.01) for PEA EOT compared to HAY, OAT SOT and OAT EOT. Acid detergent fiber rate of degradation for PEA SOT was greater (P < 0.05) compared to OAT SOT and OAT EOT. No differences (P > 0.05) were observed between either OAT SOT and OAT EOT or PEA SOT and PEA EOT for S, D, U, ED or RU suggesting that weathering did not have an effect on the degradability of the forages. The results of these experiments show that it is possible to maintain cow BW through the winter months in Western Canada by grazing oat crop residues, which have the potential to reduce winter feeding costs.

This research used high-volume air sampling (PS-1) and micro-orifice uniform deposit impactor (MOUDI) to measure concentrations of polycyclic aromatic hydrocarbons (PAHs) in the air of a agricultural residue open burning area in Jhushan and Singang station during the rice straw non-burning and burning periods. And PAHs of different size distributions are analyzed. Finally, absolute principal component analyze (APCA) model confer the probable sources of pollution in open burning area. The average PAHs concentrations were 330.04 and 567.81 ng/m3 during the rice straw non-burning and burning period in Jhushan station, the average PAHs concentrations were 427.16 and 571.80 ng/m3 during the rice straw non-burning and burning period in Singang station, respectively, in the rice straw burning period, which were higher than those on the non-burning days. The results of APCA model analysis showed that the contributions of PAHs from mobile source (gasoline and diesel) were 66.50 ¡Ó 7.99 %, burning incense in temple source were 14.83 ¡Ó 6.68 % and burning coal and wood source were 18.67 ¡Ó 6.17 % during the rice straw non-burning period. PAHs from mobile (gasoline) and rice straw non-burning source were 57.27 ¡Ó 6.90 %, mobile source (diesel) were 42.73 ¡Ó 6.89 % during the rice straw burning period in Jhushan station. The results of APCA model analysis showed that the contributions of PAHs from mobile (diesel) and burning incense in temple source were 45.67 ¡Ó 6.43 %, mobile (gasoline) and plastics incinerator source were 54.33 ¡Ó 6.39 % during the rice straw non-burning period. PAHs from burning incense in temple, rice straw, mobile (gasoline and diesel) source were 50.69 ¡Ó 4.55 %, plastics incinerator source were 36.78 ¡Ó 4.24 % and other source were 12.53 ¡Ó 2.71 %¡C

The study felld into three sections. The first section that a liquid chromatography method with fluorescence detection was developed for simultaneous determination of 11 quinolones (QNs; marbofloxacin, norfloxacin, ciprofloxacin, lomefloxacin, danofloxacin, enrofloxacin, sarafloxacin, difloxacin, oxolinic acid, nalidixic acid and flumequine) in chicken, pork, fish and shrimp. The analytes were extracted with 0.3% metaphosphoric acid: acetonitrile (1:1, v/v), followed by a HLB cartridge clean-up procedure. The HPLC separation was carried out on a symmetry column C18 (250 mm x 4.5 mm i.d., 5 £gm) with linear gradient elution of 0.1% formic acid: acetonitrile as mobile phase and programmable fluorescence detection. The method was validated by spiking blank animals tissues at three different levels (25, 50 and 250 ng/g; except 6.25, 12.5 and 62.5 ng/g for DAN) and linearity, detection limit, quantification limit, precision and accuracy were checked. Mean recoveries of 11 QNs from edible animal tissues were 71.7-105.3%. The limits of quantification in different muscle tissues ranged from 5.0 to 28.0 ng/g. The results showed it was simple, rapid, sensitive and suitable for routine test. The second section that a LC-ESI-MS/MS method was developed for determining 18 (fluoro)quinolone (QNs) residues in milk, chicken, pork, fish and shrimp. This method is capable of screening and confirming the presence of 12 amphoteric QNs (marbofloxacin, norfloxacin, enrofloxacin, ciprofloxacin, desethylene ciprofloxacin, lomefloxacin, danofloxacin, sarfloxacin, difloxacin, ofloxacin, orbifloxacin and enoxacin) and 6 acidic QNs (oxolinic acid, nalidixic acid, flumequine, cinoxacin, piromidic acid and pipemidic acid). The drugs were extracted from matrix using acetonitrile with 1% formic acid, diluted in 10% acetonitrile and defatted by extraction with hexane. The LC separation was conducted on a XDB C8 (150 x 4.6 mm, 5£gm) column with gradient elution of 20 mM ammonium formate with 0.1% formic acid¡Vacetonitrile as the mobile phase. Mass spectral acquisition was completed in the positive ion mode by applying multiple reaction mode (MRM). The decision limit (CC£\) and detection capability (CC£]) stated in the Decision No. 2002/657/EC and the ISO standard No.11843, has been calculated in the case of the nonauthorized substance. The values of CC£\ ranged from 0.18 to 0.68 ng/g and CC£] ranged from 0.24 to 0.96 ng/g under specified conditions. The third section that the pharmacokinetics of ENR and its active metabolite (CIP and des-CIP) were estimated in tilapia after intravenous (i.v.) and oral (p.o.) administration of a single dose of 2.5 and 10 mg/kg body weigh, respectively. At prefixed time points, from 0.25 h to 7 days after administration, whole blood and main tissue (liver, kidney, bile and muscle) from 4 individuals in each were collected. The concentration of ENR and its active metabolites in the main tissue were simultaneously detected by LC/MS/MS method. Limited of quantitation (LOQ) of this method were 0.01£gg/g. Pharmacokinetic parameters from both routes were described to have a two- compartment open model with first-order elimination. After i.v. administration, the area under the drug concentration-time (AUC), elimination half-life (t1/2£]), maximum plasma concentration (Cmax ), total body clearance (Cltot) and apparent volume of distribution at steady-state (Vss) of ENR were 109.6 ¡Ó 31.33 £gg.h/mL, 55.17 ¡Ó 22.84 h, 4.70 ¡Ó 0.36 £gg/mL, 14.82 ¡Ó 4.24 L/h/kg, 1105 ¡Ó 223.40 L/kg ,respectively. After oral administration, the AUC , t1/2£], Tmax , Cmax of ENR were 599.42 ¡Ó 76.19£gg.h/mL , 75.95 ¡Ó 12.94 h, 0.601¡Ó0.06h, 9.75 ¡Ó 0.46£gg/mL, respectively. After p.o. administration, CIP could be detected in liver, kidney and bile. Regarding des-CIP, the main active metabolite of CIP, could be detected in 120¡ã168 h bile among tissue. ENR and CIP had significance enterohepatic cycle in Tilapia and easily accumulated in bile. It seems reasonable to explain the phenomenon of ENR and CIP maintenance of high concentration in blood and muscle during the test time.

The exhaust valve system of combustion engines experiences a very complex contact situation of frequent impact involving micro sliding, high and varying temperatures, complex exhaust gas chemistry and possible particulates, etc. In addition, the tribological situation in the exhaust valve system is expected to become even worse due to strict future emission regulations, which will require enhanced combustion and cleaner fuels. This will substantially reduce the formation of combustion products that might ease the contact conditions by forming tribofilms on the contacting surfaces. The lack of protective films is expected to result in increased wear of the contact surfaces. The aim of the work presented in this thesis has been to increase the tribological understanding of the valves. The wear that takes place in the valve sealing interface and how the change in operating conditions affects it have been studied. Such understanding will facilitate the development of future valve designs. A test rig has been developed. It has a unique design with the ability to insert ppm amounts of media into a hot air flow, in order to simulate different environmental changes, e.g. varying amount and composition of combustion residue particles. PVD coated valves were evaluated in a dry atmosphere. It was concluded that although some of the coatings showed potential, the substrate could not support the thin, hard coatings. Investigations with an addition of different oils have been performed. Fully formulated oils proved to build up a protective oil residue tribofilm. This tribofilm has been in-depth analysed and proved to have similar composition and appearance as tribofilms found on low wear field tested valves. With a non-additivated oil, wear particles from the valve seat insert formed a wear particle tribofilm on top of the valve sealing surface. Without any oil the surfaces showed severe wear with wear particles spread over the surfaces. The results presented give a hint about what to be expected in the future, when the engine oils are replaced with ash less oils with reduced amount of additives and the consumed amount of oil within the cylinders are reduced.

The goal of our research was to optimize the conditions of chromatographic analysis of penicillin, to define minimal found analysis concentration, analyse contaminated milk samples with given certain concentration and establish resumption of penicillin G. Therefore, we aimed at analysing milk samples‘ contamination with penicillin of randomly selected cows from study farms. The research was performed in Lithuanian Academy of Veterinary which has a practical training and experiment centre in Muniskes cow farm, state enterprise „Pieno tyrimai“ and Food Institute of Kaunas Technological University. State enterprise „Pieno tyrimai“ used preparation LPT to define milk inhibitors. After the bacteriological milk samples analyses 8 out of 25 samples were found to portray remnants of inhibitory materials. Optimal chromatographic conditions were established by the use of experiment, in accordance with a thorough analysis of literature concentrating on chromatographic methods dealing with penicillin G determination. The following are defined conditions for the chromatographic examination of penicillin G: composition of a mobile phaze 0 – 10 min 5% ACN / 95% 0,125 M phosphate buffer (pH=3,5), 12-22 min 70 % ACN / 30% 0,125 M phosphate buffer, 24-30 min 5% ACN / 95% 0,125 M phosphate buffer (gradient flow mode). Period of assay suspention was about 17 minutes. Resumption of contaminated milk samples with penicillin G 500 mg/kg, 250 mg/kg, 50 mg/kg and 4 mg/kg varied from 45 to 76 %. The... [to full text]

Three studies were undertaken from 2006 to 2007 to examine litter (dead plant material) in southwestern Manitoba pastures. First, the relationship between litter and soil microclimate was tested across five pasture sites. The amount of litter biomass was not strongly related to soil moisture, though near-surface soil temperatures were reduced when litter was present. Second, the effect of four simulated grazing strategies on the litter layer was measured in six pastures. It was found that after three years of simulated grazing, litter was present in largest quantities in the least-frequently grazed treatments. Finally, a field survey was conducted assessing the quantity of litter present in native pastures across Manitoba. Litter was quite variable and averaged 1902 kg/ha over two years. This research confirmed the value of litter as an indicator of sustainable pasture management, though it remains unclear whether litter is important to pastures from the perspective of soil microclimate.

Three studies were undertaken from 2006 to 2007 to examine litter (dead plant material) in southwestern Manitoba pastures. First, the relationship between litter and soil microclimate was tested across five pasture sites. The amount of litter biomass was not strongly related to soil moisture, though near-surface soil temperatures were reduced when litter was present. Second, the effect of four simulated grazing strategies on the litter layer was measured in six pastures. It was found that after three years of simulated grazing, litter was present in largest quantities in the least-frequently grazed treatments. Finally, a field survey was conducted assessing the quantity of litter present in native pastures across Manitoba. Litter was quite variable and averaged 1902 kg/ha over two years. This research confirmed the value of litter as an indicator of sustainable pasture management, though it remains unclear whether litter is important to pastures from the perspective of soil microclimate.

Distributed mobile conversion facilities using either fast pyrolysis or torrefaction processes can be used to convert forest residues to more energy dense substances (bio-oil, bio-slurry or torrefied wood) that can be transported as feedstock for bio-fuel facilities. All feedstock are suited for gasification, which produces syngas that can be used to synthesise petrol or diesel via Fischer-Tropsch reactions, or produce hydrogen via water gas shift reactions. Alternatively, the bio-oil product of fast pyrolysis may be upgraded to produce petrol and diesel, or can undergo steam reformation to produce hydrogen. Implementing a network of mobile facilities reduces the energy content of forest residues delivered to a bio-fuel facility as mobile facilities use a fraction of the biomass energy content to meet thermal or electrical demands. The total energy delivered by bio-oil, bio-slurry and torrefied wood is 45%, 65% and 87% of the initial forest residue energy content, respectively. However, implementing mobile facilities is economically feasible when large transport distances are required. For an annual harvest of 1.717 million m3 (equivalent to 2000 ODTPD), transport costs are reduced to less than 40% of the total levelised delivered feedstock cost when mobile facilities are implemented; transport costs account for up to 80% of feedstock costs for conventional woodchip delivery. Torrefaction provides the lowest cost pathway of delivering a forest residue resource when using mobile facilities. Cost savings occur against woodchip delivery for annual forest residue harvests above 2.25 million m3 or when transport distances greater than 250 km are required. Important parameters that influence levelised delivered costs of feedstock are transport distances (forest residue spatial density), haul cost factors, thermal and electrical demands of mobile facilities, and initial moisture content of forest residues. Relocating mobile facilities can be optimised for lowest cost delivery as transport distances of raw biomass are reduced. The overall cost of bio-fuel production is determined by the feedstock delivery pathway and also the bio-fuel production process employed. Results show that the minimum cost of petrol and diesel production is 0.86 $ litre-1 when a bio-oil feedstock is upgraded. This corresponds to a 2750 TPD upgrading facility requiring an annual harvest of 4.30 million m3. The minimum cost of hydrogen production is 2.92 $ kg-1, via the gasification of a woodchip feedstock and subsequent water gas shift reactions. This corresponds to a 1100 ODTPD facility and requires an annual harvest of 947,000 m3. The levelised cost of bio-fuel strongly depends on the size of annual harvest required for bio-fuel facilities. There are optimal harvest volumes (bio-fuel facility sizes) for each bio-fuel production route, which yield minimum bio-fuel production costs. These occur as the benefits of economies of scale for larger bio-fuel facilities compete against increasing transport costs for larger harvests. Optimal harvest volumes are larger for bio-fuel production routes that use feedstock sourced from mobile facilities, as mobile facilities reduce total transport requirements. / Graduate / 0791 / drbrown@uvic.ca

This thesis presents the results of experimental and archaeological investigations of microscopic plant residues on Lapita pottery from the western Pacific Islands. Lapita is a critical phase in the culture history of the Pacific region and has been associated with the development and spread of a subsistence system based on the cultivation of tropical starch crops, particularly those in the taro-yam complex. However, few archaeobotanical remains been recovered from Lapita sites to lend empirical support to this model. This study explores whether microscopic starch granules, calcium oxalate crystals and other plant microremains on Lapita potsherds can provide direct evidence for the preparation and consumption of staple plant foods, as well as important clues to the function and use of pottery in Lapita society, matters which remain the subject of some debate. This research was undertaken in two main phases. The first involved a series of technical studies aimed at developing methods for recovering and identifying starch and raphide residues on archaeological pottery. Changes to starch during cooking and charring under different heat and moisture conditions were examined to understand how granules survive differentially depending on cooking method and food type. Various methods used to extract native starch granules from charred residues were then tested and a procedure based on a weak oxidising treatment was developed for use on the archaeological residues. The reliability of calcium oxalate raphide analysis, which is much less developed than that of starch, was also critically assessed. Issues with previous identifications of raphides in Pacific microfossil assemblages were highlighted. Morphological criteria were presented for identifying aroid raphides more accurately and chemical tests were developed to differentiate them from naturally-occurring calcite crystals, which were abundant in the sites analysed. The second phase of research analysed microscopic residues on Lapita and post-Lapita potsherds from archaeological sites in the Mussau and Anir Islands (PNG), the Reef Islands (Solomon Islands), New Caledonia, and the Samoan Archipelago. Despite the generally small quantities of residue recovered from the archaeological samples, several sherds with possible use-related starch residues were identified. These initial results indicate that ceramic vessels, including both plain and dentate-decorated Lapita wares, were employed in a variety of tasks involving the cooking and/or consumption, and storage or preparation of starch-based foods. It was also found that these were among the activities performed at the ‘special purpose’ stilt house structure at the ECA site, which raises questions about the possible social or ritual status of staple starch resources in Lapita society. One of the most significant findings to emerge from this study was of taro (Colocasia esculenta) starch granules on sherds from the ERA Lapita site (Anir, New Ireland), and granules identified tentatively as taro on sherds from RF-2 (Reef Islands) and Mulifanua (Samoa). A number of unidentified morphotypes were also present on the Lapita and post-Lapita sherds, suggesting that a variety of plants not among the key root crops were also exploited. These may include some of the many fruits and nuts attested in archaeobotanical assemblages from Pacific sites. The ceramic residue data complement starch and phytolith evidence recovered from cultural sediments from RF-2, which demonstrate the presence and probable exploitation of a suite of crop plants typically associated with the Lapita ‘economic package’. In addition to taro, these include at least one cultivated species of Eumusa banana, non-domesticated (seeded) Australimusa bananas, bamboo, and possibly also Canarium, coconut, and sago. These data support models suggesting that Lapita groups were cultivating and transporting subsistence plants, including at least one of the major root crop complexes, and associated knowledge of their production and preparation across the western Pacific from the mid-late Holocene. This study demonstrated that analyses of microscopic starch residues on archaeological ceramics from the Pacific region can yield significant insights into vessel use and plant exploitation. Further methodological refinements should aim to increase starch yields, which will enable stronger associations between residues and vessel uses to be established. Expansion of reference collections is also required so that more precise identifications of the specific plant foods involved can be achieved.