3,552 research outputs found
Tracer profiles across argillaceous formations: A tool to constrain transport processes.
No full textThe spatial distributions of non-reactive natural tracers (anions, stable water isotopes, noble gases) in pore water of clay-rich formations were studied at nine sites. Regular curved profiles were identified in most cases. Transport modeling considering diffusion, advection and available constraints on the paleo-hydrogeological evolution indicates generally that diffusion alone can explain the observations, whereas a marked advective component would distort the profiles and so is not consistent with the data
Flow behavior of aluminum-based materials at ultrahigh temperatures in the presence of a liquid phase
No full textExperiments were conducted to determine the flow behavior of three materials at ultrahigh temperatures: an Al-6061 composite containing 20 vol% SiC whiskers and unreinforced Al-6061 and Al-1050 alloys prepared by casting. Tensile tests were performed at strain rates up to 5× 10-1 s-1 and over a range of ultrahigh temperatures up to and above the temperatures where there is a small amount of liquid phase. High strain rate superplasticity was achieved in the composite material but not in the unreinforced alloys. For all three materials, it is shown that the true activation energy for flow changes from values of <200 kJ mol-1 at the lower temperatures where there is no liquid phase to exceptionally high values in the presence of a liquid phase: these values are up to >1000 kJ mol-1 for the composite and the Al-1050 alloy. It is concluded that exceptionally high activation energies are an inherent feature of flow in materials containing a small amount of discontinuous liquid at temperatures immediately above the onset of partial melting. <br/
On the activation energies observed in Al-based materials deformed at ultrahigh temperatures
No full textThis study examines the exceptionally high activation energies estimated fi om data obtained from various composites exhibiting high strain rate superplasticity and loaded at ultrahigh temperatures near or slightly above the solidus. It is shown that the activation energies for the 6061 composite and for Al 6061 and 1050 alloys are below 200 kJ/mol at temperatures lower than the incipient melting temperature, T-i, but they become significantly higher at temperatures near or slightly above T-i and this increase is independent of the alloy system, the grain size, whether the material is superplastic and the dominant deformation mechanism at T<T-i. There is a transition from plastic flow in a solid state to a viscous-like flow behavior in the Al-6061 systems at T>610 degreesC and in the Al-1050 alloy at T>650 degreesC. It is concluded that the high values of Q(t) have no physical meaning in terms of the rate-controlling diffusive species
Increased cardiomyocyte apoptosis following ischemia and reperfusion in diet-induced hypercholesterolemia: relation to Bcl-2 and Bax protein and caspase-3 activity.
No full textAttenuation of increased myocardial ischaemia-reperfusion injury conferred by hypercholesterolaemia through pharmacological inhibition of the caspase-1 cascade.
No full textMorphological modelling of Lai Giang Inlet, Vietnam.
No full textThe Lai Giang inlet located in Binh Dinh province incorporates various features of the estuaries in the Central part of Vietnam. Belonging to the micro-tidal and wave-dominant coast and influenced by the monsoon regime, the inlet has a seasonal character. During the dry season, as the river flow diminishes, the wave action causes high level of sedimentation and closes up the inlet eventually. In flood season, as the river discharge is high, the channel is scoured and the inlet begins to migrate. The high sedimentation level and migration of the Lai Giang inlet has been a serious problem of Binh Dinh province for a long time, because it is the only exit for the floodway. It is an anchorage and also the connection between the sea and the aquaculture area of Hoai Nhon district. The high level of sedimentation at the entrance of the inlet prevents river flood from flowing smoothly, thus leading to overflow in lowlands and navigation issues. In recent decades, the exploitation and protection of Lai Giang area have been studied in various forms of scientific researches and projects by different scientists and local professional agencies. However, the studies have only focused on hydraulics, hydrology and on adjusting the flow of Lai Giang river. There are only general and basic studies on the entrance of the inlet. The main objective of this research is to understand the morphological behaviour of Lai Giang inlet. The specific interest is focused on the main factors which are the tidal characteristic, the wave climate and the river flow during the flood season, and the interaction between all these factors that influence the morphological changes. The study starts with the collecting and analysing all the documentations to come up with a conceptual model of the Lai Giang inlet to explain how the sedimentation and the migration processes happen. Then, the Delft3D modelling software, which can model (tidal) flow, waves and sediment transport, has been applied to confirm the hypothesis and gain further knowledge. According to the data analysis, the conceptual model as well as the descriptive and quantitative result of the model, we can make the following main conclusions: 1. The wave climate in this area has seasonal characteristic and is dominated by two main directions; Northeast and Southeast in winter and summer monsoon, respectively. 2. During the summer monsoon, the longshore sediment transport moves towards the north, bypasses the entrance of the inlet and gradually builds up on the down-drift spit due to the Southeast Wave. 3. During winter monsoon, the Northeast wave intensifies the southward longshore sediment transport leading to the large amount of sedimentation in front of the inlet. At the same time, the significant river flow flushes away the sediment deposits at the main ebb channel located nearer to the up-drift spit. Thus the sedimentation could not take place at the up-drift spit. The sediment displacement at the up-drift and down-drift spit made the inlet migrate to the north gradually. Finally, the possibility to stabilize the inlet is discussed to give the optimum solution for this area.CoMEM - Coastal and Marine Engineering and ManagementHydraulic EngineeringCivil Engineering and Geoscience
A Study of Jewish Philanthropic Company Colonization in Canada`s Northwest Territories During the Late Nineteenth Century
Full text linkSince the author of this study is of Mennonite ethnic origin it
is perhaps in order to explain how he came to write this study of an
aspect of Jewish History. As an undergraduate his interests lay in
modern European History and Russian Intellectual History during the late
nineteenth century. In 1975, however, his attention was drawn to a
national essay competition sponsored by the Jewish Historical Society of
Western Canada in honour of the Bronfman Family. The author was able to
complete a paper, 'Jewish Agricultural Settlement in Western Canada,
1870-1930' while doing contract research related to the development of a
travelling display for the Western Development Museum in Saskatoon
during the summer of 1976. Dr. T.D. Regehr, who supervised the research
permitted the paper to be submitted to the contest and it was awarded
second prize of $200.
Al though the paper was based on available secondary sources
only, the author had been able to ascertain that there were primary
sources available for more detailed study of aspects of Jewish
Agricultural Settlement in the West. The author's attention was drawn
to Hirsch Colony in particular because of the sharply divergent
portrayals of its history and role in the development of Jewish
agriculture in Western Canada. Jewish literature suggested that it was
at least a moderate success and that it contributed significantly to the
later improvement of Jewish agriculture's progress in the West.
Government sources often quoted in the secondary sources, however, were
generally very negative about Jewish agriculture in general and about
Hirsch Colony in particular. This intrigued the author and resulted in
this study of the Colony's role in determining the direction taken by
Jewish Agricultural Colonization in Western Canada and its influence on
Dominion Lands Policy regarding assisted settlement in general and
Jewish agriculture in particular.
This study grew out of the natural curiosity sparked by the
essay contest, the contract research, and the author's own interest in
the ethnic variety and agricultural foundations of Western Canada
Studies in Singular Optics and Coherence Theory
No full textIn this dissertation, the field of singular optics is examined in terms of common laboratory experiments. Different types of field singularities are related to one another. Problems in coherence theory related to two correlated sources are also investigated.Electrical EngineeringElectrical Engineering, Mathematics and Computer Scienc
Studies in Physical Optics: Coherence Theory and Surface Plasmons
No full textTelecommunicationsElectrical Engineering, Mathematics and Computer Scienc
Measuring the group velocity dispersion of higher order modes in hollow core photonic bandgap fibre
Full text linkWe present for the first time the group velocity dispersion of multiple distinguishable modes propagating in 3, 7 and 19 cell hollow core photonic bandgap fibres. Measurements are made by direct phase extraction from spectral domain low coherence interferometry
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