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Bohr model and dimensional scaling analysis of atoms and moleculesUrtekin, Kerim 25 April 2007 (has links)
It is generally believed that the old quantum theory, as presented by Niels Bohr
in 1913, fails when applied to many-electron systems, such as molecules, and nonhydrogenic
atoms. It is the central theme of this dissertation to display with examples
and applications the implementation of a simple and successful extension of BohrâÂÂs
planetary model of the hydrogenic atom, which has recently been developed by an
atomic and molecular theory group from Texas A&M University. This âÂÂextendedâÂÂ
Bohr model, which can be derived from quantum mechanics using the well-known
dimentional scaling technique is used to yield potential energy curves of H2 and several
more complicated molecules, such as LiH, Li2, BeH, He2 and H3, with accuracies
strikingly comparable to those obtained from the more lengthy and rigorous âÂÂab initioâÂÂ
computations, and the added advantage that it provides a rather insightful and
pictorial description of how electrons behave to form chemical bonds, a theme not
central to âÂÂab initioâ quantum chemistry. Further investigation directed to CH, and
the four-atom system H4 (with both linear and square configurations ), via the interpolated
Bohr model, and the constrained Bohr model (with an effective potential),
respectively, is reported. The extended model is also used to calculate correlation
energies.
The model is readily applicable to the study of molecular species in the presence
of strong magnetic fields, as is the case in the vicinities of white dwarfs and neutron
stars. We find that magnetic field increases the binding energy and decreases the bond length.
Finally, an elaborative review of doubly coupled quantum dots for a derivation of
the electron exchange energy, a straightforward application of Heitler-London method
of quantum molecular chemistry, concludes the dissertation.
The highlights of the research are (1) a bridging together of the pre- and post
quantum mechanical descriptions of the chemical bond (Bohr-Sommerfeld vs Heisenberg-
Schrèodinger), and (2) the reporting of the appearance of new bound states of H2 in
the presence of very strong magnetic fields. The new states emerge above the critical
value of 5 ÃÂ 107 G, and hence cannot be obtained perturbatively.
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Three-dimensional fluvial-deltaic sequence stratigraphy Pliocene-Recent Muda Formation, Belida Field, West Natuna Basin, IndonesiaDarmadi, Yan 25 April 2007 (has links)
The Pliocene-Recent Muda formation is essentially undeformed in the West
Natuna Basin, and excellent resolution of this interval on three-dimensional seismic data
in Belida Field allows detailed interpretation of component fluvial-deltaic systems.
Detailed interpretation of seismic time slice and seismic sections along with seismic
facies analysis, horizon mapping, and extraction of seismic attributes provide the basis to
construct a sequence stratigraphic framework and determine patterns for sediment
dispersal and accumulation.
The Muda interval contains five third-order sequences, with depositional
environments confined to the shelf and consisting mainly of fluvial elements. Sequence
boundaries (SB) apparently result from major sea level falls, since there was no tectonic
uplift and the field underwent only regional slow subsidence during sedimentation of the
study interval.
Sea level fluctuation also caused changes in fluvial patterns. Analysis of
changing channel patterns indicates that major systems tracts relate to specific channel
patterns. The Lowstand Systems Tract (LST) is generally dominated by larger channel dimensions and low sinuosity channel patterns. The Transgressive Systems Tract (TST)
typically contains relatively smaller channels with high sinuosity. Channels in the
Highstand Systems Tract (HST) generally show moderate sinuosity channels and are
intermediate in size, larger than TST channels but smaller than LST channels. Crossplots
of stratigraphic position and channel morphology indicate that within the transition from
LST-TST, channel dimensions (width and thickness) generally decrease and channel
sinuosity generally increases.
High sinuosity, meandering and anastomosing channels are generally found near
the maximum flooding surface. Low sinuosity channels occur within the HST-SB-LST
succession, with the exception of higher sinuosity meandering channels evolving inside
valleys. Larger, lower sinuosity channels result from high gradient and high discharge
associated with stream piracy. Smaller, high-sinuosity channels result from low gradient
and small discharge.
Extraction of seismic attributes such as RMS Amplitude and Average Reflection
Strength show these depositional features in greater detail. In the Belida Field area,
lowstand channels were found to comprise the greatest volume of sandstone bodies.
Seismic delineation of the distribution and morphology of these channel systems provides
critical input for reservoir modeling and volumetric analysis.
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The effect of of clerodane diterpenoid 16-hydroxycleroda-3,13-dien-15,16-olide on colorectal cancer cell linesChen, Chiu-Roung 15 July 2008 (has links)
Polyalthia longifolia is a lofty evergreen tree found in India and Sri Lanka. Today, P. longifolia var. pendula is in large-scale cultivation in south Taiwan as a landscape plant. A new compound, clerodane diterpenoid 16-hydroxycleroda-3,13-dien-15, 16 -olide¡]CD¡^, was isolated from the bark of Polyalthia longifolia var. pendula. The compound was shown with cell growth inhibitory property at first screen in KMU¡]Kaohsiung Medical University¡^. In our study, antiproliferative activity of CD on human colorectal adenocarcinoma cells¡]HT29 and HCT116¡^were tested and the inhibitory concertration of 50¢Mcell viability¡]IC50¡^is 5 £gg/ml¡]HCT116¡^ and 10 £gg/ml¡]HT29¡^determined by MTT(3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide) assay. The caspase 3 and PARP cleavage experiment results indicated that CD induced apoptosis is dose dependent manner. We found that CD induced sub-G1 accumulation and reactive oxygen species(ROS) release by flow cytometry analysis. Pretreatment of N-Acetyl-L-cystine(NAC), an antioxidant agent, can reverse the anti-proliferation effect by CD. We found that CD induced loss of mitochondria membrane potentiol¡]£G£Zm¡^. We also analysis differentially expressed proteins by 2-D electrophoresis and find drug response proteins, e.g. HSP10, Profilin-1, Peroxindoxin-1. RT-PCR and western blot was performed to confirm the protein expression changes. It is interesting to reveal the role of these proteins in the colorectal cancinogenesis and anti-tumor drug response.
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Numerical study for a micro-PEMFCLin, Kuan-Wen 21 August 2008 (has links)
A three dimensional numerical model for a micro proton exchange membrane fuel cell was developed to simulate the concentration distribution of the fuel gas, and analyze the flow field and current field in the fuel cell. Finite control volume scheme with SIMPLEC algorithm was employed in the numerical method.
Various operating conditions on the performance of the fuel cell were studied. It was shown that the concentration of oxygen at the cathode can strongly influence the cell performance. Increase the operating temperature and the pressure of the inlet gas can improve the performance of the fuel cell.
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Analysis of Sp1 associated transcription regulatory factors bound on TSG101 promoter by DAPA and two dimensional gel electrophoresisLIN, I-Ju 25 August 2008 (has links)
TSG101 is a tumor susceptibility gene exhibits multiple biological functions, including the regulation of vesicular trafficking, transcription, cellular growth and differentiation. The intracellular steady-state level of TSG101 was shown to under stringent control in a narrow range. Either deprivation or overexpression of mouse tsg101 in NIH3T3 cells leads to neoplastic transformation and subsequent tumorigenic potential of the transformed cells. However, the detail mechanism for regulation of TSG101 gene promoter activity is not clear. Our results indicated TSG101 is a housekeeping gene and contains a TATA-less and Sp1 binding site promoter. Here, we demonstrate in vivo binding of Sp1 transcription factor on TSG101 promoter region by chromatin immunoprecipitation(ChIP). In addition, Sp1-associated transcription regulators were purified using DNA affinity precipitation assay (DAPA) method and subjected to two-dimensional gel electrophoresis and the subsequent MALDI-TOF analysis. Our results verify the biding of Sp1 transcription on the DAPA probe containing wildtype but not the mutant Sp1 biding sequence by subsequent western blotting. Our MALDI-TOF analysis of protein spots from two-dimensional gel did not reveal the binding of Sp1 protein, instead the identified a number of cellular proteins, such as U5 small nuclear RNP¡BATP-dependent DNA helicase 2 and actin of unknown significance.
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Spacecraft pose estimation via a cascading genetic algorithm /Obsniuk, Mark. January 2006 (has links)
Thesis (M.Sc.)--York University, 2006. Graduate Programme in Computer Science. / Typescript. Includes bibliographical references (leaves 157-162). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR29596
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Improvement of the camera calibration through the use of machine learning techniquesNichols, Scott A., January 2001 (has links) (PDF)
Thesis (M.S.)--University of Florida, 2001. / Title from first page of PDF file. Document formatted into pages; contains vii, 45 p.; also contains graphics. Vita. Includes bibliographical references (p. 43-44).
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Theoretical study of dynamic intensity fluctuations in mesoscopic 1D and Quasi-1D systems /Lu, Danyong. January 2009 (has links)
Includes bibliographical references (p. 58-63).
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Experimental and theoretical investigation of optical nonlinearity in one-dimensional photonic crystal with central defect mode /Wong, Tsz Chun. January 2009 (has links)
Includes bibliographical references (p. 74-79).
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[Pi]-line reconstruction formulas in computed tomography /Hass, Ryan Andrew. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 115-117). Also available on the World Wide Web.
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