The Neogene sediment from the Pattani Basin, Gulf of Thailand, were subjected to detailed organic geochemical study. The results suggest that the Neogene source rocks have potential for hydrocarbon generation (as shown by high TOC content). Sequences 2, 3 and part of Sequence 4 are mature and capable of producing hydrocarbons, while those from Sequence 5 are immature. The top of the oil window estimated from biomarker maturity parameters (i.e. CPI and homohopane ratios) is at approximately 6000 feet. SCI data also support this proposal. The biomarker composition and distributions of the bitumen extracts reflect the abundance of higher plant contributions with varying amount of bacterial input, in oxic to sub-oxic conditions during deposition of the sediments. A strong contribution of terrestrially derived organic matter (higher plants) is indicated by the bimodal distribution of <i>n</i>-alkanes, OEP distribution of the <i>n</i>-alkanes in the range C₂₃-C₃₃, high Pr/Ph ratios, low S%, the occurrence and abundance of several biological markers, including oleanenes, oleanane, bicadinanes, tricyclic terpanes, abnormally high C₃₁ homohopane R epimer, and high C₂₉ steranes. Abundant coals in Sequences 5 and 4 contain higher plant material, interpreted as deposited in deltaic swamp environments. Kerogen typing shows that vitrinite (Type III kerogen) is the dominant organic matter in the samples from the Pattani Basin, suggesting potential to generate gas and condensate. The other organic macerals found include cutinite and spore/pollen (Type II kerogen), amorphous (Type I/II/III kerogen) and inertinite (Type IV). In general, molecular and microscopic examination of the Neogene succession of the Pattani Basin suggests a fluvio-deltaic environment, with peat swamps in Sequence 5 and the upper part of Sequence 4. This interpretation is confirmed by pollen analysis data. The age diagnostic pollen found in a few samples from Sequence 5 suggest the time of deposition as Middle Miocene to Pliocene.

A monokinetic beam of neutrons (0.07 e.v.) has been scattered by a gas, and the angular dependence of scattering measured over the range 0° to 90°. This isbelieved to be the first measurement of neutrons diffracted by gas molecules. The experiments were performed with a modified neutron crystal spectrometer using a beam of neutronsfrom the Chalk River pile. The gases studied, CO2 and O2, were at room temperature and approximately 60 atmospheres pressure. Observed intensity distributions are compared with calculated patterns. The latter are based on classical interference theory, so take no account of inelasticscattering. Good angular agreement of interference peaks is found for both gases. Good relative intensity agreement is found for 02, but the measured intensity for CO2 falls below thecalculated curve at small angles. A possible reason for this is given.

Stable carbon isotope fractionation during methanogenesis is affected by the availability of substrates. The effects of different substrates on methanogen biomass, total lipid extract, biomarkers and methane under both abundant and limiting substrate conditions were studied. Methanosarcina barkeri was grown with methanol, acetate, trimethylamine (TMA) and H2/CO2, and carbon isotope fractionation in methane production was greatest with methanol, followed by H2/CO2, TMA and acetate. In contrast, biomass was isotopically lightest in M.barkeri grown on methanol, followed by TMA, H2/CO2 and acetate. Generally, fractionation was greater in cultures grown with abundant substrate availability as compared to those supplied with limiting substrate. During autotrophic growth, fractionation was greatest during slower growth for both methane and biomass production. The results of these fractionation studies under controlled laboratory conditions can be applied to the interpretation of isotopic signatures for methane and methanogen biomarkers, and ecological processes, in marine environments. Several hypersaline springs off the western shore of Lake Winnipegosis, MB support unique microbial mat communities. These low temperature springs contain water with a mean salinity as high as 6.1%. Studies were undertaken to contrast the anaerobic microbial communities of these springs, specifically the methanogens and sulphate-reducing bacteria (SRB), and their contributions to biogeochemical cycling in these mats. Comparisons of lipid profiles revealed changes in the proportions of the dominant fatty acids related to the amount of mat growth. Cultures of SRB and methanogens were established with six different substrates. Methanogenic cultures grew best on TMA and methanol, but could use formate, H2/CO2 and glycine betaine as well. In contrast, H2/CO2 was the preferred substrate of the SRB enrichment cultures, which were also able to use formate, but not TMA, the breakdown product of the compatible solute glycine betaine. Maximum methane production occurred at 5% salinity. The lipid composition of the mats, including methanogen biomarkers, and the results of the enrichments on different substrates and at different salinities, suggest that methanogenesis in these springs is supported by compatible solutes whereas sulphate reduction is linked to availability of hydrogen and formate.

Carbon dioxide is one of the major greenhouse gases being cycled by forests. Mature boreal forests are often carbon sinks, however, following disturbance, forests can become carbon sources. Three forest sites in central Saskatchewan burned in 1977 (F77 site), 1989 (F89 site), and 1998 (F98 site) were studied using eddy covariance to obtain measurements of the energy, carbon, and water budgets. Latent heat flux density increased gradually over time at F98 but remained lower than F77 and F89. Weekly net ecosystem production was lower at F98 than at F77 and F89. F77 lost 40 g C m-2 and 79 g C m-2 in 2004 and 2005, respectively. F89 gained 177 g C m-2, 113 g C m-2, and 88 g C m-2 in 2003, 2004, and 2005, respectively. F98 lost 5 g C m-2, 17 g C m-2, and 52 g C m-2 during these three years, respectively.

The impregnation of mesoporous carbon cloth with alumina has been studied. The most successful method of impregnation resulted from preparation of the alumina phase by a sol/gel route. This method involves a boehmite intermediate, and the heating environment for the thermal transition of boehmite to the final alumina was investigated. Heat treatment of the boehmite intermediate under flowing N2, flowing air and vacuum was found to give a different pore size distribution for the final alumina than did still air heat treatment. For the former environments the transition from boehmite to alumina was not accompanied by the usual increase in pore size. Alumina/carbon composites were made by dipping pieces of mesoporous carbon cloth in a boehmite sol. The distribution of boehmite about the carbon cloth was found to be improved by pre-wetting the carbon cloth and by the use of ultrasonic dispersion during boehmite impregnation. Dried boehmite/carbon composites, with loading levels of up to 180wt.%, were heated under vacuum to 5000 C. In this manner alumina/carbon composites of up to 60wt.% alumina were fabricated. The distribution of the alumina phase about the carbon cloth was investigated by electron microscopy and by gas adsorption techniques. Nitrogen isotherm data indicated that the mesopores of the carbon cloth were not blocked by the deposited alumina, rather the pore volume of the carbon cloth was increased by the clustering of porous alumina about the pore entrances of the carbon cloth. Water isotherms were determined for the composite materials. The water activity of the composite, particularly at low relative pressures, was found to be significantly greater than that of the carbon cloth as a result of the presence of alumina. CO2 activity of the composites was investigated by a gas chromatographic technique. The CO2 activity of the composite material was found to be up to 500 times greater than that of virgin carbon cloth.

An extensive study of into the static loading response and low-velocity impact response of plain and stiffened CFRP panels was conducted. The study investigated the impact response of the CFRP panels over a range of impact energies that include incident kinetic energies sufficiently high to cause complete penetration of the panel by the impacting mass. Static tests were also conducted by driving a hemispherical-nosed indentor into the panel up to displacements that resulted in the complete penetration of the panel by the indentor. Results from these tests suggest that the static perforation energy could predict the impact perforation energy with reasonable accuracy. A lumped-parameter mass-spring-damper model that attempted to incorporate the effects of material damage to the panel response was developed. The model was found to be sufficiently accurate in predicting the response of thin panels to static and impact loads up to the critical delamination force threshold. Assessment of the damaged panels through Penetrant-Enhanced X-Ray methods led to the identification of damage transition energy thresholds that differentiate between changes in damage mechanism. The damage transition energy thresholds were found to be constant fractions of the impact perforation energy.

No description available.

A flux measurement setup was established at a communications tower north of downtown Houston, Texas, to measure energy and trace gas fluxes from a variety of emission sources in the urban surface layer. The first part of this study details the development of a correction for latent heat and carbon dioxide (CO2) fluxes due to a low-pass filtering of the true water vapor and CO2 atmospheric signals. A method of spectral analysis was used to develop a correction scheme for this flux underestimation through the observation that the low-pass filtering is a strong function of atmospheric relative humidity and wind speeds. The determined flux corrections for latent heat fluxes (average correction of 34%) were significantly larger than CO2 fluxes (3-4%), suggesting the low-pass filtering had a more dominant effect on the water vapor signal. For the second part of this study, we describe a quadrant analysis technique for separating measured net fluxes into their biogenic (c’ < 0 and q’ > 0 signals) and anthropogenic (c’ > 0 and T’ > 0 signals) components, and quantify these fluxes through the use of a refined relaxed eddy accumulation model. A method of minimizing a defined net – (biogenic + anthropogenic) residual was used to determine an accurate “hole” around the origin to exclude points in the desired quadrants that appear there randomly. The magnitude of the biogenic flux contribution showed expected relationships with temperature and irradiance. The anthropogenic flux contribution showed a strong correlation with measured traffic counts collected on local thoroughfares. Due to a presumed small bias in the flux calculation methodology, neither flux contribution truly measured zero, so anthropogenic and biogenic “background” fluxes were calculated (0.01 µmol mo^-1 m s^-1 and 0.01 – 0.02 µmol mol^-1 m s^-1 respectively). Future work involves perfecting the model, with the goal being widespread use of the theory at urban flux sites. The accurate separation of the net flux gives a more complete picture of the carbon cycle and allows for more accurate analysis of the effects of increased temperature and CO2 concentration on urban vegetation as compared to non-urban vegetation.

Stable carbon isotope fractionation during methanogenesis is affected by the availability of substrates. The effects of different substrates on methanogen biomass, total lipid extract, biomarkers and methane under both abundant and limiting substrate conditions were studied. Methanosarcina barkeri was grown with methanol, acetate, trimethylamine (TMA) and H2/CO2, and carbon isotope fractionation in methane production was greatest with methanol, followed by H2/CO2, TMA and acetate. In contrast, biomass was isotopically lightest in M.barkeri grown on methanol, followed by TMA, H2/CO2 and acetate. Generally, fractionation was greater in cultures grown with abundant substrate availability as compared to those supplied with limiting substrate. During autotrophic growth, fractionation was greatest during slower growth for both methane and biomass production. The results of these fractionation studies under controlled laboratory conditions can be applied to the interpretation of isotopic signatures for methane and methanogen biomarkers, and ecological processes, in marine environments. Several hypersaline springs off the western shore of Lake Winnipegosis, MB support unique microbial mat communities. These low temperature springs contain water with a mean salinity as high as 6.1%. Studies were undertaken to contrast the anaerobic microbial communities of these springs, specifically the methanogens and sulphate-reducing bacteria (SRB), and their contributions to biogeochemical cycling in these mats. Comparisons of lipid profiles revealed changes in the proportions of the dominant fatty acids related to the amount of mat growth. Cultures of SRB and methanogens were established with six different substrates. Methanogenic cultures grew best on TMA and methanol, but could use formate, H2/CO2 and glycine betaine as well. In contrast, H2/CO2 was the preferred substrate of the SRB enrichment cultures, which were also able to use formate, but not TMA, the breakdown product of the compatible solute glycine betaine. Maximum methane production occurred at 5% salinity. The lipid composition of the mats, including methanogen biomarkers, and the results of the enrichments on different substrates and at different salinities, suggest that methanogenesis in these springs is supported by compatible solutes whereas sulphate reduction is linked to availability of hydrogen and formate.

Carbon dioxide is one of the major greenhouse gases being cycled by forests. Mature boreal forests are often carbon sinks, however, following disturbance, forests can become carbon sources. Three forest sites in central Saskatchewan burned in 1977 (F77 site), 1989 (F89 site), and 1998 (F98 site) were studied using eddy covariance to obtain measurements of the energy, carbon, and water budgets. Latent heat flux density increased gradually over time at F98 but remained lower than F77 and F89. Weekly net ecosystem production was lower at F98 than at F77 and F89. F77 lost 40 g C m-2 and 79 g C m-2 in 2004 and 2005, respectively. F89 gained 177 g C m-2, 113 g C m-2, and 88 g C m-2 in 2003, 2004, and 2005, respectively. F98 lost 5 g C m-2, 17 g C m-2, and 52 g C m-2 during these three years, respectively.