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Physical Sciences and Mathematics Commons

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2008

San Jose State University

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Articles 1 - 30 of 63

Full-Text Articles in Physical Sciences and Mathematics

Temperature Dependence Investigation Of Dissipation Processes In Strongly Anisotropic High-Temperature Superconductors Of Bi-Pb-Sr-Ca-Cu-O System Synthesized Using Solar Energy, J Chigvinadze, Juana Acrivos, S. Ashimov, D. Gulamova, T. Machaidze, D Uskenbaev Oct 2008

Temperature Dependence Investigation Of Dissipation Processes In Strongly Anisotropic High-Temperature Superconductors Of Bi-Pb-Sr-Ca-Cu-O System Synthesized Using Solar Energy, J Chigvinadze, Juana Acrivos, S. Ashimov, D. Gulamova, T. Machaidze, D Uskenbaev

Faculty Publications, Chemistry

The investigation of temperature dependence of damping and period of vibrations of HTSC superconductive cylinder of Bi-Pb-Sr-Ca-Cu-O system suspended by a thin elastic thread and performing axial-torsional vibrations in a magnetic field at temperatures above the critical one for the main phase Tc=107 K were carried out. It was observed some "chaos" temperature region in the temperature interval 107-138 K, where it is seen separate ripples of dissipation and oscillation frequency. It is assumed that the "chaos" region could point to a possibility of existence of other magnetic and more high-temperature phases as single islands in a normal materials matrix.


Word Sense Disambiguation In Biomedical Ontologies With Term Co-Occurrence Analysis And Document Clustering, Bill Andreopoulos, Dimitra Alexopoulou, Michael Schroeder Sep 2008

Word Sense Disambiguation In Biomedical Ontologies With Term Co-Occurrence Analysis And Document Clustering, Bill Andreopoulos, Dimitra Alexopoulou, Michael Schroeder

Faculty Publications, Computer Science

With more and more genomes being sequenced, a lot of effort is devoted to their annotation with terms from controlled vocabularies such as the GeneOntology. Manual annotation based on relevant literature is tedious, but automation of this process is difficult. One particularly challenging problem is word sense disambiguation. Terms such as |development| can refer to developmental biology or to the more general sense. Here, we present two approaches to address this problem by using term co-occurrences and document clustering. To evaluate our method we defined a corpus of 331 documents on development and developmental biology. Term co-occurrence analysis achieves an …


Effect Of Long-Range Hopping On Tc In A Two-Dimensional Hubbard-Holstein Model Of The Cuprates, Ehsan Khatami, A. Macridin, M. Jarrell Aug 2008

Effect Of Long-Range Hopping On Tc In A Two-Dimensional Hubbard-Holstein Model Of The Cuprates, Ehsan Khatami, A. Macridin, M. Jarrell

Faculty Publications

We study the effect of long-range hoppings on Tc for the two-dimensional (2D) Hubbard model with and without Holstein phonons using parameters evaluated from band-structure calculations for cuprates. Employing the dynamical cluster approximation (DCA) with a quantum Monte Carlo (QMC) cluster solver for a 4-site cluster, we observe that without phonons, the long-range hoppings, t′ and t′′, generally suppress Tc. We argue that this trend remains valid for larger clusters. In the presence of the Holstein phonons, a finite t′ enhances Tc in the under-doped region for the hole-doped system, consistent with local-density approximation (LDA) calculations and experiment. This is …


Unraveling Protein Networks With Power Graph Analysis, Loïc Royer, Matthias Reimann, Bill Andreopoulos, Michael Schroeder Jul 2008

Unraveling Protein Networks With Power Graph Analysis, Loïc Royer, Matthias Reimann, Bill Andreopoulos, Michael Schroeder

Faculty Publications, Computer Science

Networks play a crucial role in computational biology, yet their analysis and representation is still an open problem. Power Graph Analysis is a lossless transformation of biological networks into a compact, less redundant representation, exploiting the abundance of cliques and bicliques as elementary topological motifs. We demonstrate with five examples the advantages of Power Graph Analysis. Investigating protein-protein interaction networks, we show how the catalytic subunits of the casein kinase II complex are distinguishable from the regulatory subunits, how interaction profiles and sequence phylogeny of SH3 domains correlate, and how false positive interactions among high-throughput interactions are spotted. Additionally, we …


Climate Change Education And The Ecological Footprint, Eugene C. Cordero, Anne Marie Todd, Diana Abellera Jun 2008

Climate Change Education And The Ecological Footprint, Eugene C. Cordero, Anne Marie Todd, Diana Abellera

Faculty Publications, Meteorology and Climate Science

Global warming has become one of the most important scientific, political, and social issues of our era. In designing an effective mitigation strategy, it is clear that public education must play an important role. This study looks at various components of climate change literacy within a cohort of university students and investigates the impact of action-oriented learning on student understanding. Results from questionnaires given to primarily nonscience students enrolled in weather and climate courses are used to examine student knowledge of climate change. In agreement with prior research, this study finds that signif icant student misconceptions exist regarding the causes …


Climate Change Education And The Ecological Footprint, Eugene Cordero, Anne Marie Todd, D. Abellerra Jun 2008

Climate Change Education And The Ecological Footprint, Eugene Cordero, Anne Marie Todd, D. Abellerra

Anne Marie Todd

No abstra


W(H)Ither Fossils? Studying Morphological Character Evolution In The Age Of Molecular Sequences, Elizabeth J. Hermsen, Jonathan R. Hendricks Apr 2008

W(H)Ither Fossils? Studying Morphological Character Evolution In The Age Of Molecular Sequences, Elizabeth J. Hermsen, Jonathan R. Hendricks

Faculty Publications

A major challenge in the post-genomics era will be to integrate molecular sequence data from extant organisms with morphological data from fossil and extant taxa into a single, coherent picture of phylogenetic relationships; only then will these phylogenetic hypotheses be effectively applied to the study of morphological character evolution. At least two analytical approaches to solving this problem have been utilized: (1) simultaneous analysis of molecular sequence and morphological data with fossil taxa included as terminals in the analysis, and (2) the molecular scaffold approach, in which morphological data are analyzed over a molecular backbone (with constraints that force extant …


Selfish Wavelength Assignment In Multifiber Optical Networks, Evangelos Bampas, Aris Pagourtzis, George Pierrakos, Katerina Potika Apr 2008

Selfish Wavelength Assignment In Multifiber Optical Networks, Evangelos Bampas, Aris Pagourtzis, George Pierrakos, Katerina Potika

Faculty Publications, Computer Science

No abstract provided.


Metcrax 2006 - Meteorological Experiments In Arizona's Meteor Crater, C. David Whiteman, Sebastian Hoch, Maura Hahnenberger, Andreas Muschinski, Vincent Hohreiter, Mario Behn, Yonghum Cheon, Sharon Zhong, Wenqing Yao, David Fritts, Craig Clements, Thomas Horst, William Brown, Steven Oncley Jan 2008

Metcrax 2006 - Meteorological Experiments In Arizona's Meteor Crater, C. David Whiteman, Sebastian Hoch, Maura Hahnenberger, Andreas Muschinski, Vincent Hohreiter, Mario Behn, Yonghum Cheon, Sharon Zhong, Wenqing Yao, David Fritts, Craig Clements, Thomas Horst, William Brown, Steven Oncley

Faculty Publications, Meteorology and Climate Science

The Meteor Crater Experiment (METCRAX 2006) was conducted in October 2006 at Arizona's Meteor Crater to investigate stable boundary layer evolution in a topographically uncomplicated basin surrounded by the nearly homogeneous plain of the Colorado Plateau. The two goals of the experiment were 1) to investigate the microscale and mesoscale structure and evolution of the stable boundary layer in the crater and its surroundings and 2) to determine whether atmospheric seiches or standing waves are produced inside the crater. This article provides an overview of the scientific goals of the experiment; summarizes the research measurements, the crater topography, and the …


Forcing Mechanisms For Washoe Zephyr - A Daytime Downslope Wind Phenomenon In The Great Basin East Of The Sierra Nevada, Shiyuan Zhong, Ju Li, Craig Clements, Stephan Dewekker, Xindi Bian Jan 2008

Forcing Mechanisms For Washoe Zephyr - A Daytime Downslope Wind Phenomenon In The Great Basin East Of The Sierra Nevada, Shiyuan Zhong, Ju Li, Craig Clements, Stephan Dewekker, Xindi Bian

Faculty Publications, Meteorology and Climate Science

This paper investigates the formation mechanisms for a local wind phenomenon known as Washoe Zephyr that occurs frequently in the lee of the Sierra Nevada. Unlike the typical thermally driven slope flows with upslope wind during daytime and downslope at night, the Washoe Zephyr winds blow down the lee slopes of the Sierra Nevada in the afternoon against the local pressure gradient. Long-term hourly surface wind data from several stations on the eastern slope of the Sierra Nevada and rawinsonde sounding data in the region are analyzed and numerical simulations are performed to test the suggested hypotheses on the formation …


First Observations Of Turbulence Generated By Grass Fires, Craig Clements, Shiyuan Zhong, Xindi Bian, Warren Heilman, Daewon Byun Jan 2008

First Observations Of Turbulence Generated By Grass Fires, Craig Clements, Shiyuan Zhong, Xindi Bian, Warren Heilman, Daewon Byun

Faculty Publications, Meteorology and Climate Science

Wildland fires radically modify the atmospheric boundary layer by inducing strong fire-atmosphere interactions. These interactions lead to intense turbulence production in and around the fire front. Two field experiments were conducted in tall-grass fuels to quantify turbulence generation during the passage of wind-driven fire fronts. Observations showed that the measured turbulence generated by the fires was five times greater than the turbulence in the ambient environment. The production of the turbulence at the surface near the fire front was caused by increased variance of the ambient wind, while the buoyancy was strongest at higher levels within the fire plume. Immediately …


Favourable Influence Of Hydrophobic Surfaces On Protein Structure In Porous Organically-Modified Silica Glasses, Daryl K. Eggers, B. Menaa, M. Herrero, V. Rives, M. Lavrenko Jan 2008

Favourable Influence Of Hydrophobic Surfaces On Protein Structure In Porous Organically-Modified Silica Glasses, Daryl K. Eggers, B. Menaa, M. Herrero, V. Rives, M. Lavrenko

Faculty Publications, Chemistry

Organically-modified siloxanes were used as host materials to examine the influence of surface chemistry on protein conformation in a crowded environment. The sol–gel materials were prepared from tetramethoxysilane and a series of monosubstituted alkoxysilanes, RSi(OR′)3, featuring alkyl groups of increasing chain length in the R-position. Using circular dichroism spectroscopy in the far-UV region, apomyoglobin was found to transit from an unfolded state to a native-like helical state as the content of the hydrophobic precursor increased from 0 to 15%. At a fixed molar content of 5% RSi(OR′)3, the helical structure of apomyoglobin increased with the chain length of the R-group, …


Botnets And Distributed Denial Of Service Attacks, Anilkumar Panicker Jan 2008

Botnets And Distributed Denial Of Service Attacks, Anilkumar Panicker

Master's Projects

With their ever increasing malicious capabilities and potential to infect a vast majority of computers on the Internet, botnets are emerging as the single biggest threat to Internet security. The aim of this project is to perform a detailed analysis of botnets and the vulnerabilities exploited by them to spread themselves and perform various malicious activities such as DDoS attacks. DDoS attacks are without doubt the most potent form of attacks carried out by botnets. In order to better understand this growing phenomenon and develop effective counter measures, it is necessary to be able to simulate DDoS attacks in a …


Bibliography Data Mining And Data Visualization, Deepthi Pullannagari Jan 2008

Bibliography Data Mining And Data Visualization, Deepthi Pullannagari

Master's Projects

Data mining is a concept of discovering meaningful patterns from large data repositories, and Data visualization is a graphical representation of data using shapes, colors and images for a better conceptualization. These two techniques have been in use for a long time now and are used together in number of fields to gain a better perception of the data. Bibliographic data is widely used in academic and scientific literature fields and this project deals with data mining and data visualization of bibliographic data downloaded from Citeseer Citation Indexing system. The downloaded metadata is extracted into the database, looking for patterns …


Fuzzy Range Query In Xml, Dexiong Zhang Jan 2008

Fuzzy Range Query In Xml, Dexiong Zhang

Master's Projects

This writing project presents a new approach to implement a fuzzy range query solution for retrieving Extensible Markup Language (XML) data. Ever since XML was introduced, it has become a web standard to describe data on the Internet. The need for performing range query against XML data is growing day by day. Many search service providers are eager to improve their solutions on range query against XML data. The project studies and analyzes the limitations on the current range query solutions. The project also proposes a new solution using fuzzy semantic analysis to quantify XML data so that it can …


Personalized Shopping Agent For Semantic Web, Ramani Arunachalam Jan 2008

Personalized Shopping Agent For Semantic Web, Ramani Arunachalam

Master's Projects

Current online shopping experience has limitations due to lack of uniform, inter- linked machine readable data across various shopping sites. This project attempts to improve the experience by employing semantic web concepts such as OWL and SPARQL. A new OWL ontology is defined for product data and real-life data from shopping sites such as Amazon, Yahoo shopping are imported and inter-linked using this ontology. A web-based personalized shopping agent is implemented to query this inter- linked database by specifying the preferences for various product attributes. Screenshots of the resulting system and its usage have been provided.


Sql Injection Analysis, Detection And Prevention, Jagdish Halde Jan 2008

Sql Injection Analysis, Detection And Prevention, Jagdish Halde

Master's Projects

Web sites are dynamic, static, and most of the time a combination of both. Web sites need protection in their database to assure security. An SQL injection attacks interactive web applications that provide database services. These applications take user inputs and use them to create an SQL query at run time. In an SQL injection attack, an attacker might insert a malicious SQL query as input to perform an unauthorized database operation. Using SQL injection attacks, an attacker can retrieve or modify confidential and sensitive information from the database. It may jeopardize the confidentiality and security of Web sites which …


Heuristic Health Resource Referral (H2r2) Engine, Duy Vo Jan 2008

Heuristic Health Resource Referral (H2r2) Engine, Duy Vo

Master's Projects

Searching for health resources is difficult for many individuals because it requires domain knowledge and understanding of search engines techniques. Our system proposes a paradigm shift whereby users provide as much or as little information as they feel comfortable, and we endeavor to match them with relevant health resources. The system first attempts to identify risk factors through a heuristic engine that employs fuzzy logic and then searches for health resources based on the user’s profile. We aim to unburden the user from having to understand complex health information and sometimes esoteric search techniques. Our preliminary findings show that a …


Intelligent Query For Real Estate Search, Mandeep Jandir Jan 2008

Intelligent Query For Real Estate Search, Mandeep Jandir

Master's Projects

The purpose of this project is to improve search query accuracy in a real estate website by developing an intelligent query system which provides the best matching result for standard search criteria. This intelligent query website utilizes fuzzy logic and partial membership to filter query results based on user input data. Fuzzy logic helps obtain results that are otherwise not attainable from a non-fuzzy search. A non-fuzzy search entails search results that match exactly with the given criteria. This project also allows a user to do a free keyword search. This type of search uses synonyms of the keywords to …


A Promising Change In The Selection Of The Circular Polarization Excitation Used In The Measurement Of Eu(Iii) Circularly Polarized Luminescence, K. Do, F. C. Muller, Gilles Muller Jan 2008

A Promising Change In The Selection Of The Circular Polarization Excitation Used In The Measurement Of Eu(Iii) Circularly Polarized Luminescence, K. Do, F. C. Muller, Gilles Muller

Gilles Muller

A judicious change in the selected transition used for circular polarization excitation will overcome the low oscillator strength limitation of the currently allowed magnetic-dipole 5D1 ← 7F2 (Eu(III)) transition chosen for circularly polarized luminescence (CPL) measurement. The proposed allowed magnetic-dipole 5D1 ← 7F0 (Eu(III)) transition will facilitate the detection of CPL from the Eu(III) systems of interest. CPL on the acetonitrile solution of the chiral tris complex of Eu(III) with (R,R)-N,N′-bis(1-phenylethyl)-2,6-pyridinedicarboxamide ([Eu((R,R)-1)3]3+), recently suggested as an effective and reliable CPL calibrating agent, confirms the feasibility of the proposed experimental procedure. A comparable CPL activity exhibited by the acetonitrile solution of …


Stochastic Hard-Sphere Dynamics For Hydrodynamics Of Non-Ideal Fluids, Alejandro Garcia, Aleksandar Donev, Berni J. Alder Jan 2008

Stochastic Hard-Sphere Dynamics For Hydrodynamics Of Non-Ideal Fluids, Alejandro Garcia, Aleksandar Donev, Berni J. Alder

Alejandro Garcia

A novel stochastic fluid model is proposed with a nonideal structure factor consistent with compressibility, and adjustable transport coefficients. This stochastic hard sphere dynamics (SHSD) algorithm is a modification of the direct simulation Monte Carlo algorithm and has several computational advantages over event-driven hard-sphere molecular dynamics. Surprisingly, SHSD results in an equation of state and a pair correlation function identical to that of a deterministic Hamiltonian system of penetrable spheres interacting with linear core pair potentials. The fluctuating hydrodynamic behavior of the SHSD fluid is verified for the Brownian motion of a nanoparticle suspended in a compressible solvent.


The Dark Matter Halo Of Ngc 1399- Cdm Or Mond?, T. Richtler, Y. Schuberth, M. Hilker, B. Dirsch, L. Bassino, Aaron J. Romanowsky Jan 2008

The Dark Matter Halo Of Ngc 1399- Cdm Or Mond?, T. Richtler, Y. Schuberth, M. Hilker, B. Dirsch, L. Bassino, Aaron J. Romanowsky

Aaron J. Romanowsky

Context. Central galaxies in galaxy clusters may be key discriminants in the competition between the cold dark matter (CDM) paradigm and modified Newtonian dynamics (MOND). Aims. We investigate the dark halo of NGC 1399, the central galaxy of the Fornax cluster, out to a galactocentric distance of 80 kpc. Methods.The data base consists of 656 radial velocities of globular clusters obtained with MXU/VLT and GMOS/Gemini, which is the largest sample so far for any galaxy. We performed a Jeans analysis for a non-rotating isotropic model. Results.An NFW halo with the parameters $r_{\rm s} = 50\,\rm {kpc}$ and $\varrho_{\rm s} = …


Testing The Nature Of S0 Galaxies Using Planetary Nebula Kinematics In Ngc 1023, E. Noordermeer, M. R. Merrifield, L. Coccato, M. Arnaboldi, M. Capaccioli, N. G. Douglas, K. C. Freeman, O. Gerhard, K. Kuijken, F. De Lorenzi, N. R. Napolitano, Aaron J. Romanowsky Jan 2008

Testing The Nature Of S0 Galaxies Using Planetary Nebula Kinematics In Ngc 1023, E. Noordermeer, M. R. Merrifield, L. Coccato, M. Arnaboldi, M. Capaccioli, N. G. Douglas, K. C. Freeman, O. Gerhard, K. Kuijken, F. De Lorenzi, N. R. Napolitano, Aaron J. Romanowsky

Aaron J. Romanowsky

We investigate the manner in which lenticular galaxies are formed by studying their stellar kinematics: an S0 formed from a fading spiral galaxy should display similar cold outer disc kinematics to its progenitor, while an S0 formed in a minor merger should be more dominated by random motions. In a pilot study, an attempt to distinguish between these scenarios, we have measured the planetary nebula (PN) kinematics of the nearby S0 system NGC 1023. Using the Planetary Nebula Spectrograph, we have detected and measured the line-of-sight velocities of 204 candidate planetary nebulae (PNe) in the field of this galaxy. Out …


Favourable Influence Of Hydrophobic Surfaces On Protein Structure In Porous Organically-Modified Silica Glasses, Daryl K. Eggers, B. Menaa, M. Herrero, V. Rives, M. Lavrenko Jan 2008

Favourable Influence Of Hydrophobic Surfaces On Protein Structure In Porous Organically-Modified Silica Glasses, Daryl K. Eggers, B. Menaa, M. Herrero, V. Rives, M. Lavrenko

Daryl K. Eggers

Organically-modified siloxanes were used as host materials to examine the influence of surface chemistry on protein conformation in a crowded environment. The sol–gel materials were prepared from tetramethoxysilane and a series of monosubstituted alkoxysilanes, RSi(OR′)3, featuring alkyl groups of increasing chain length in the R-position. Using circular dichroism spectroscopy in the far-UV region, apomyoglobin was found to transit from an unfolded state to a native-like helical state as the content of the hydrophobic precursor increased from 0 to 15%. At a fixed molar content of 5% RSi(OR′)3, the helical structure of apomyoglobin increased with the chain length of the R-group, …


Protein Adsorption Onto Organically-Modified Silica Glass Leads To A Different Structure Than Sol-Gel Encapsulation, Daryl K. Eggers, B, Menaa, C. Torres, M. Herrero, V. Rives, A. R.W Gilbert Jan 2008

Protein Adsorption Onto Organically-Modified Silica Glass Leads To A Different Structure Than Sol-Gel Encapsulation, Daryl K. Eggers, B, Menaa, C. Torres, M. Herrero, V. Rives, A. R.W Gilbert

Daryl K. Eggers

The secondary structures of two proteins were examined by circular dichroism spectroscopy after adsorption onto a series of organically modified silica glasses. The glasses were prepared by the sol-gel technique and were varied in hydrophobicity by incorporation of 5% methyl, propyl, trifluoropropyl, or n-hexyl silane. Both cytochrome c and apomyoglobin were found to lose secondary structure after adsorption onto the modified glasses. In the case of apomyoglobin, the α-helical content of the adsorbed protein ranged from 21% to 28%, well below the 62% helix found in solution. In contrast, these same glasses led to a striking increase in apomyoglobin structure …


Protein Adsorption Onto Organically-Modified Silica Glass Leads To A Different Structure Than Sol-Gel Encapsulation, Daryl K. Eggers, B, Menaa, C. Torres, M. Herrero, V. Rives, A. R.W Gilbert Jan 2008

Protein Adsorption Onto Organically-Modified Silica Glass Leads To A Different Structure Than Sol-Gel Encapsulation, Daryl K. Eggers, B, Menaa, C. Torres, M. Herrero, V. Rives, A. R.W Gilbert

Faculty Publications, Chemistry

The secondary structures of two proteins were examined by circular dichroism spectroscopy after adsorption onto a series of organically modified silica glasses. The glasses were prepared by the sol-gel technique and were varied in hydrophobicity by incorporation of 5% methyl, propyl, trifluoropropyl, or n-hexyl silane. Both cytochrome c and apomyoglobin were found to lose secondary structure after adsorption onto the modified glasses. In the case of apomyoglobin, the α-helical content of the adsorbed protein ranged from 21% to 28%, well below the 62% helix found in solution. In contrast, these same glasses led to a striking increase in apomyoglobin structure …


A Promising Change In The Selection Of The Circular Polarization Excitation Used In The Measurement Of Eu(Iii) Circularly Polarized Luminescence, K. Do, F. C. Muller, Gilles Muller Jan 2008

A Promising Change In The Selection Of The Circular Polarization Excitation Used In The Measurement Of Eu(Iii) Circularly Polarized Luminescence, K. Do, F. C. Muller, Gilles Muller

Faculty Publications, Chemistry

A judicious change in the selected transition used for circular polarization excitation will overcome the low oscillator strength limitation of the currently allowed magnetic-dipole 5D1 ← 7F2 (Eu(III)) transition chosen for circularly polarized luminescence (CPL) measurement. The proposed allowed magnetic-dipole 5D1 ← 7F0 (Eu(III)) transition will facilitate the detection of CPL from the Eu(III) systems of interest. CPL on the acetonitrile solution of the chiral tris complex of Eu(III) with (R,R)-N,N′-bis(1-phenylethyl)-2,6-pyridinedicarboxamide ([Eu((R,R)-1)3]3+), recently suggested as an effective and reliable CPL calibrating agent, confirms the feasibility of the proposed experimental procedure. A comparable CPL activity exhibited by the acetonitrile solution of …


Evidence Contrary To The Statistical View Of Boosting, David Mease, A. Wyner Jan 2008

Evidence Contrary To The Statistical View Of Boosting, David Mease, A. Wyner

Faculty Publications

The statistical perspective on boosting algorithms focuses on optimization, drawing parallels with maximum likelihood estimation for logistic regression. In this paper we present empirical evidence that raises questions about this view. Although the statistical perspective provides a theoretical framework within which it is possible to derive theorems and create new algorithms in general contexts, we show that there remain many unanswered important questions. Furthermore, we provide examples that reveal crucial flaws in the many practical suggestions and new methods that are derived from the statistical view. We perform carefully designed experiments using simple simulation models to illustrate some of these …


Stochastic Hard-Sphere Dynamics For Hydrodynamics Of Non-Ideal Fluids, Alejandro Garcia, A. Donev, B. J. Alder Jan 2008

Stochastic Hard-Sphere Dynamics For Hydrodynamics Of Non-Ideal Fluids, Alejandro Garcia, A. Donev, B. J. Alder

Faculty Publications

A novel stochastic fluid model is proposed with a nonideal structure factor consistent with compressibility, and adjustable transport coefficients. This stochastic hard sphere dynamics (SHSD) algorithm is a modification of the direct simulation Monte Carlo algorithm and has several computational advantages over event-driven hard-sphere molecular dynamics. Surprisingly, SHSD results in an equation of state and a pair correlation function identical to that of a deterministic Hamiltonian system of penetrable spheres interacting with linear core pair potentials. The fluctuating hydrodynamic behavior of the SHSD fluid is verified for the Brownian motion of a nanoparticle suspended in a compressible solvent.


Testing The Nature Of S0 Galaxies Using Planetary Nebula Kinematics In Ngc 1023, E. Noordermeer, M. R. Merrifield, L. Coccato, M. Arnaboldi, M. Capaccioli, N. G. Douglas, K. C. Freeman, O. Gerhard, K. Kuijken, F. De Lorenzi, N. R. Napolitano, Aaron J. Romanowsky Jan 2008

Testing The Nature Of S0 Galaxies Using Planetary Nebula Kinematics In Ngc 1023, E. Noordermeer, M. R. Merrifield, L. Coccato, M. Arnaboldi, M. Capaccioli, N. G. Douglas, K. C. Freeman, O. Gerhard, K. Kuijken, F. De Lorenzi, N. R. Napolitano, Aaron J. Romanowsky

Faculty Publications

We investigate the manner in which lenticular galaxies are formed by studying their stellar kinematics: an S0 formed from a fading spiral galaxy should display similar cold outer disc kinematics to its progenitor, while an S0 formed in a minor merger should be more dominated by random motions. In a pilot study, an attempt to distinguish between these scenarios, we have measured the planetary nebula (PN) kinematics of the nearby S0 system NGC 1023. Using the Planetary Nebula Spectrograph, we have detected and measured the line-of-sight velocities of 204 candidate planetary nebulae (PNe) in the field of this galaxy. Out …