Spelling suggestions: "subject:"its"" "subject:"fits""
1 |
Gas chromatographic, mass spectrometric and stable carbon isotope investigations of organic residues in `slab-lined pits' from Arctic NorwayHeron, Carl P., Nilsen, G., Stern, Ben, Craig, O.E., Nordby, C.C. January 2010 (has links)
No / Gas chromatography-mass spectrometry (GC-MS) and bulk carbon isotope determinations have been performed on samples ('cemented organic residues', charcoal, sediment and fire-cracked rock) excavated from twelve slab-lined pits from various locations in Arctic Norway to test the premise that these archaeological features were used for the extraction of oil from the blubber of marine mammals, such as seal, whale and walrus. A wide range of lipid compound classes were detected especially in the cemented organic residues and in the charcoal samples. The presence of long-chain unsaturated and isoprenoid fatty acids together with oxidation and thermal alteration products of unsaturated acids such as dicarboxylic acids, dihydroxyfatty acids and ω-(o-alkylphenyl)alkanoic acids suggests that these features were used for marine oil extraction at elevated temperatures. Notably the location of the hydroxyl groups in the dihydroxyfatty acids provides a record of the positional isomer of the precursor fatty acid and allows confirmation that 11-docosenoic (cetoleic) acid, the most abundant C22:1 isomer in marine oil, was a major component of the original lipid. Further information was provided by the presence of long-chain fatty acyl moieties in surviving triacylglycerols and the presence of cholesterol. A fungal metabolite, mycose (trehalose), was found in all samples apart from a fire-cracked rock and points to microbiological activity in the pits. Bulk isotope analysis conducted on the 'cemented organic residues' is consistent with modern reference samples of blubber and oil from seal and whale. These data provide clear analytical evidence of the function of slab-lined pits in the archaeological record and suggest widespread exploitation of marine mammals for producing oil for heating, lighting and myriad other uses in the past.
|
2 |
Geostatistics applied to probabilistic slope stability analysis in the china clay deposits of CornwallPascoe, Denise Margaret January 1996 (has links)
No description available.
|
3 |
Factors influencing the Nucleation and Morphology of Crystallographic Type Etch Pits in Pure Iron.Spink, Geoffrey 08 1900 (has links)
<p> Etch pits can be produced in iron whose shape reflects the crystallography of the crystal. It is shown that pit morphology can be adequately predicted from an orientation dependent dissolution theory. The influence of an air-formed surface oxide film on pit nucleation and morphology is demonstrated. </p> / Thesis / Master of Science (MSc)
|
4 |
Voices of Toronto - An Intercultural Urban LibraryJanes, Allison January 2010 (has links)
In the last one hundred years Toronto’s cultural identity has been completely transformed. Once a quiet and thoroughly conservative Anglo-Saxon town, Toronto has become a thriving and dynamic multicultural city. Today a majority of the city’s residents are visible minorities and almost half are foreign-born; the largest of any city in the world. Never before have so many ‘different’ people shared place. While successive waves of immigration have had a profound and measurable impact on Toronto’s cultural and social character, the impact on its public spaces and institutions remains more illusive.
This thesis proposes an architectural design for an intercultural library and language centre that seeks to give voice to the principles of diversity that have energized Toronto, while acknowledging the city’s history of divisiveness and political indifference to immigrants. Set adjacent to the Bickford Centre, an existing ESL school dedicated to serving new immigrants, the proposed intercultural library and language centre will face the Christie Pits Park, the site of Toronto’s worst race riot.
Three lines of inquiry structure this thesis. The first is an in-depth sociodemographic investigation of immigration to Toronto. This is followed by an analysis of the meaning and significance of critical intercultural gathering spaces in the city. Finally, the thesis, through the design of the language centre, seeks to explore the capacity of architecture to simultaneously unite and provide amenity for a multicultural city population.
|
5 |
Voices of Toronto - An Intercultural Urban LibraryJanes, Allison January 2010 (has links)
In the last one hundred years Toronto’s cultural identity has been completely transformed. Once a quiet and thoroughly conservative Anglo-Saxon town, Toronto has become a thriving and dynamic multicultural city. Today a majority of the city’s residents are visible minorities and almost half are foreign-born; the largest of any city in the world. Never before have so many ‘different’ people shared place. While successive waves of immigration have had a profound and measurable impact on Toronto’s cultural and social character, the impact on its public spaces and institutions remains more illusive.
This thesis proposes an architectural design for an intercultural library and language centre that seeks to give voice to the principles of diversity that have energized Toronto, while acknowledging the city’s history of divisiveness and political indifference to immigrants. Set adjacent to the Bickford Centre, an existing ESL school dedicated to serving new immigrants, the proposed intercultural library and language centre will face the Christie Pits Park, the site of Toronto’s worst race riot.
Three lines of inquiry structure this thesis. The first is an in-depth sociodemographic investigation of immigration to Toronto. This is followed by an analysis of the meaning and significance of critical intercultural gathering spaces in the city. Finally, the thesis, through the design of the language centre, seeks to explore the capacity of architecture to simultaneously unite and provide amenity for a multicultural city population.
|
6 |
Synthesis of Mesoporous Carbons from Date Pits for the Adsorption of Large Molecular Weight Micropollutants in WastewaterAl Jeffrey, Ahmed 07 1900 (has links)
Efficient reuse of waste water requires removal of micro-pollutants from waste
water streams by affordable and sustainable methods. Activated carbon is
considered a powerful adsorbent due to its high surface area and low cost of
treatment, compared to other expensive methods such as membrane filtration.
Producing activated carbon with larger mesoporosity (>2nm) is of particular
interest in industry in the removal of larger molecular sized pollutants.
This study reports the synthesis of mesoporous activated carbons from a nonsoluble
biomass precursor (date-pits) along with chemical activation using ZnCl2.
Thus, produced activated carbon showed high surface area and large mesopore
volume up to 1571 m2/g and 2.00 cm3/g respectively. In addition, the pore size of
the product was as high as 9.30 nm. As a method of verification, HRTEM (Highresolution
transmission electron microscopy) was used to directly authenticate the
pore size of the synthesized activated carbons.
Tannic acid and atrazine were used as model waste water pollutants and the
adsorption capability of the produced activated carbon for these pollutants were
evaluated and compared to a commercial mesoporous carbon: G60 from Norit. The
results showed that the sorption capacity of produced activated carbon for tannic
acid was 2 times that of G60 while the sorption capacity of produced activated
carbon for atrazine was lower than that of G60. The activated carbon was also
evaluated for adsorption of real secondary effluent municipal wastewater and the
results suggest that the produced activated carbon was able to sorb a greater
amount of biopolymers than G60. These results demonstrate that the thus-produced
activated carbon may be a promising sorbent for waste water treatment.
|
7 |
Insights into the morphological changes undergone by the anode in the lithium sulphur battery systemYalamanchili, Anurag January 2014 (has links)
In this thesis, the morphological changes of the anode surface in lithium sulphur cell, during early cycling, were simulated using symmetrical lithium electrode cells with dissolved polysulphides (PS) in the electrolyte. Electron microscopy (SEM) was used as the principal investigation technique to study and record the morphological changes. The resulting images from the SEM were analysed and discussed. The initial surface structure of the lithium anode largely influenced the ensuing morphological changes taking place through lithium dissolution (pits) and lithium deposition (dendrites) during discharge and charge respectively. The rate of lithium dissolution and deposition was found to be linearly proportional to the current density applied to the cell and the effect of cycling on the anode was proportional to the total charge of the cell in general in agreement with the expected reaction. The effect of self-discharge on the anode was also studied using photoelectron spectroscopy (XPS) in tandem with SEM. The results indicated that self-discharge, occurring in the form of corrosion of the anode SEI by PS reduction, was influenced by the altered morphology of the cell after cycling. The findings presented in this project can be understood as a preliminary description for the morphological changes in the anode and their influence in the performance of lithium sulphur battery, which can be further investigated by more advanced methods. / <p>Joint collaboration project between Scania CV AB and Uppsala University.</p>
|
8 |
Size and Shape Stasis in Late Pleistocene Mammals and Birds From Rancho La Brea During the Last Glacial-Interglacial CycleProthero, Donald R., Syverson, Valerie J., Raymond, Kristina R., Madan, Meena, Molina, Sarah, Fragomeni, Ashley, DeSantis, Sylvana, Sutyagina, Anastasiya, Gage, Gina L. 21 November 2012 (has links)
Conventional neo-Darwinian theory views organisms as infinitely sensitive and responsive to their environments, and considers them able to readily change size or shape when they adapt to selective pressures. Yet since 1863 it has been well known that Pleistocene animals and plants do not show much morphological change or speciation in response to the glacial-interglacial climate cycles. We tested this hypothesis with all of the common birds (condors, golden and bald eagles, turkeys, caracaras) and mammals (dire wolves, saber-toothed cats, giant lions, horses, camels, bison, and ground sloths) from Rancho La Brea tar pits in Los Angeles, California, which preserves large samples of many bones from many well-dated pits spanning the 35,000 years of the Last Glacial-Interglacial cycle. Pollen evidence showed the climate changed from chaparral/oaks 35,000 years ago to snowy piñon-juniper forests at the peak glacial 20,000 years ago, then back to the modern chaparral since the glacial-interglacial transition. Based on Bergmann's rule, we would expect peak glacial specimens to have larger body sizes, and based on Allen's rule, peak glacial samples should have shorter and more robust limbs. Yet statistical analysis (ANOVA for parametric samples; Kruskal-Wallis test for non-parametric samples) showed that none of the Pleistocene pit samples is statistically distinct from the rest, indicating complete stasis from 35 ka to 9 ka. The sole exception was the Pit 13 sample of dire wolves (16 ka), which was significantly smaller than the rest, but this did not occur in response to climate change. We also performed a time series analysis of the pit samples. None showed directional change; all were either static or showed a random walk. Thus, the data show that birds and mammals at Rancho La Brea show complete stasis and were unresponsive to the major climate change that occurred at 20 ka, consistent with other studies of Pleistocene animals and plants. Most explanations for such stasis (stabilizing selection, canalization) fail in this setting where climate is changing. One possible explanation is that most large birds and mammals are very broadly adapted and relatively insensitive to changes in their environments, although even the small mammals of the Pleistocene show stasis during climate change, too.
|
9 |
Solution PitsBell, John Robert 04 1900 (has links)
Littoral solution pits were studied along 4 shorelines in the Guelph and Amabel Formations of the Bruce Peninsula. Pit depths, diameters, and densities were measured at several elevations above and below water, and various distances from the shoreline. Differences in pit characteristics were related to differences in shoreline energies, lithologies, and fluctuating lake levels in the post glacial period.
Pit depths above water are shallower than pit depths below water. This conclusion supports previous hypotheses proposed by Cowell (1976) and Ford (in Goodchild, 1984) that the depth of solution pits increase with increasing water depth. The conclusions also indicate that pits are initiated above water, and that solutional deepening of pits can occur underwater. / Thesis / Bachelor of Science (BSc)
|
10 |
Härdens Bruk Och Olika Betydelser : En undersökning av härdar och kokgropar frånyngre bronsålder och äldre järnålder / The use of hearths and their different meanings : A study of hearths and cooking pits from Early Bronze Age and Roman Iron AgeHansson, Malin January 2022 (has links)
Hearths and cooking pits are common remains from the Bronze Age. It is a trace of human activity possibly over a short or sometimes a longer period of time. Settlement, cooking and crafts are what we associate them with, but these remains have an underestimated potential to tell us more about the people who used them. Being o pen to a broader perspective might provide a better understanding of the phenomena. By examining more closely new interpretations of hearths and cooking pits, we see new meaning and significance of these features which can be seen as a previously overlook ed cultural expression. Based on previous studies, the thesis will further explain and argue for the cultural significance of hearths and cooking pits from the Bronze Age and early Iron Age.
|
Page generated in 0.188 seconds