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2006

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Articles 4831 - 4860 of 5872

Full-Text Articles in Physical Sciences and Mathematics

Construction Of Rational Points On Elliptic Curves Over Finite Fields, Andrew Shallue, Christiaan Van De Woestijne Jan 2006

Construction Of Rational Points On Elliptic Curves Over Finite Fields, Andrew Shallue, Christiaan Van De Woestijne

Scholarship

We give a deterministic polynomial-time algorithm that computes a nontrivial rational point on an elliptic curve over a finite field, given a Weierstrass equation for the curve. For this, we reduce the problem to the task of finding a rational point on a curve of genus zero.


The Symmetric Teleparallel Gravity, Muzaffer Adak Jan 2006

The Symmetric Teleparallel Gravity, Muzaffer Adak

Turkish Journal of Physics

We study symmetric teleparallel (STP) gravity model, in which only spacetime non-metricity is nonzero. First we obtain STP equivalent Einstein-Hilbert Lagrangian and give an approach for a generic solution in terms of only metric tensor. Then we obtain a spherically symmetric static solution to the Einstein's equation in STP space-time and discuss the singularities. Finally, we study a model given by a Lagrangian 4-form quadratic in non-metricity. Thus, we seek Schwarzschild-type solutions because of its observational success and obtain some sets of solutions. Finally, we discuss physical relevance of the solutions.


The Calculations Of Oscillator Strengths And Transition Probabilities For Atomic Fluorine, Gülteki̇n Çeli̇k, H. Şükür Kiliç, Erhan Akin Jan 2006

The Calculations Of Oscillator Strengths And Transition Probabilities For Atomic Fluorine, Gülteki̇n Çeli̇k, H. Şükür Kiliç, Erhan Akin

Turkish Journal of Physics

Oscillator strengths for transitions between individual lines belonging to some doublet and quartet terms, and multiplet transition probabilities of atomic fluorine have been calculated using weakest bound electron potential model theory (WBEPMT). In the determination of relevant parameters, we employed numerical non-relativistic Hartree-Fock (NRHF) wave functions for expectation values of radii and the necessary energy values have been taken from experimental energy data in the literature. Oscillator strengths and transition probabilities obtained in this work have been compared to experimental and theoretical values given in the literature.


Neogene - Quaternary Stratigraphy Of Ki̇raz - Beydağ Vicinity, Küçük Menderes Graben, West Anatolia, Tahir Emre, Hasan Sözbi̇li̇r, Nuran Gökçen Jan 2006

Neogene - Quaternary Stratigraphy Of Ki̇raz - Beydağ Vicinity, Küçük Menderes Graben, West Anatolia, Tahir Emre, Hasan Sözbi̇li̇r, Nuran Gökçen

Bulletin of the Mineral Research and Exploration

No abstract provided.


Winter 2006, Nsu Oceanographic Center Jan 2006

Winter 2006, Nsu Oceanographic Center

Currents

No abstract provided.


Integrating Schedulability Analysis With Uml-Rt, Qimin Gao, Lyndon Brown, Luiz Fernando Capretz Jan 2006

Integrating Schedulability Analysis With Uml-Rt, Qimin Gao, Lyndon Brown, Luiz Fernando Capretz

Electrical and Computer Engineering Publications

The use of object oriented techniques and methodologies for the design of real-time control systems appear to be necessary in order to deal with the increasing complexity of such systems. Recently many object-oriented methods have been used for the modeling and design of real-time control systems. We believe that an approach that integrates the advancements in both object modeling and design methods, and real-time scheduling theory is the key to successful use of object oriented technology for real-time software. However, past approaches to integrate the two either restrict the object models, or do not allow sophisticated schedulability analysis techniques. In …


Electrochemical Deposition And Characterization Of Fe₃O₄ Films Produced By The Reduction Of Fe(Iii)-Triethanolamine, Hiten M. Kothari, Elizabeth A. Kulp, Steven J. Limmer, Philippe Poizot, Eric W. Bohannan, Jay A. Switzer Jan 2006

Electrochemical Deposition And Characterization Of Fe₃O₄ Films Produced By The Reduction Of Fe(Iii)-Triethanolamine, Hiten M. Kothari, Elizabeth A. Kulp, Steven J. Limmer, Philippe Poizot, Eric W. Bohannan, Jay A. Switzer

Chemistry Faculty Research & Creative Works

In this paper, we demonstrate that films of magnetite, Fe3O4, can be deposited by the electrochemical reduction of a Fe(III)-triethanolamine complex in aqueous alkaline solution. the films were deposited with a columnar microstructure and a [100] preferred orientation on stainless steel substrates. In-plane electrical transport and magnetoresistance measurements were performed on the films after they were stripped off onto glass substrates. the resistance of the films was dependent on the oxygen partial pressure. We attribute the increase in resistance in O2 and the decrease in resistance in Ar to the oxidation and reduction of grain …


Acid-Catalyzed Time-Efficient Synthesis Of Resorcinol-Formaldehyde Aerogels And Crosslinking With Isocyanates, Sudhir Mulik, Chariklia Sotiriou-Leventis, Nicholas Leventis Jan 2006

Acid-Catalyzed Time-Efficient Synthesis Of Resorcinol-Formaldehyde Aerogels And Crosslinking With Isocyanates, Sudhir Mulik, Chariklia Sotiriou-Leventis, Nicholas Leventis

Chemistry Faculty Research & Creative Works

Aerogels are open-cell foams derived from supercritical fluid (SCF) drying of wet gels. Their large internal void space is responsible for low thermal conductivity, high surface area and high acoustic impedance. Most aerogels are based on inorganic metal or semimetal oxide frameworks. Pekala and co-workers synthesized resorcinol-formaldehyde (RF) organic aerogels by poly-condensation of resorcinol with formaldehyde in the presence of Na2CO3 as base catalyst, followed by drying with SCF CO2. Low-density RF aerogels prepared by this method exhibit high porosities (>80%), high surface areas (400-900 m2g-1), ultrafine cell-size (<500 > Å) …


A Comparative Study Of The Properties Of Polar And Nonpolar Solvent/Solute/Polystyrene Solutions In Microwave Fields Via Molecular Dynamics, Mark J. Purdue, Macduff O. Okuom, Frank D. Blum, James M. D. Macelroy, D. F. O'Shea Jan 2006

A Comparative Study Of The Properties Of Polar And Nonpolar Solvent/Solute/Polystyrene Solutions In Microwave Fields Via Molecular Dynamics, Mark J. Purdue, Macduff O. Okuom, Frank D. Blum, James M. D. Macelroy, D. F. O'Shea

Chemistry Faculty Research & Creative Works

The influence of an applied microwave field on the dynamics of methylamine-dichloromethane (DCM) mixtures bound within atactic polystyrene (a-PS) over a range of polymer densities from 30 to 94 wt % polymer was examined using atomistic molecular dynamics simulations. This study is an extension of previous studies on methylamine transport in relatively polar polystyrene solutions of methanol and dimethylformamide [M. J. Purdue et al., J. Chem. Phys. 124, 204904 (2006)]. A direct comparison is made across the three types of polystyrene solutions. Consideration is given to both solvent and reagent transport within the polymer solutions under zero-field conditions and in …


Molecular Mass And Dynamics Of Poly(Methyl Acrylate) In The Glass Transition Region, Burak Metin, Frank D. Blum Jan 2006

Molecular Mass And Dynamics Of Poly(Methyl Acrylate) In The Glass Transition Region, Burak Metin, Frank D. Blum

Chemistry Faculty Research & Creative Works

The segmental dynamics of bulk poly(methyl acrylate) (PMA) were studied as a function of molecular mass in the glass-transition region using 2H NMR and modulated differential scanning calorimetry (MDSC). Quadrupole-echo 2H NMR spectra were obtained for four samples of methyl-deuterated PMA-d3 with different molecular masses. The resulting spectra were fit using superpositions of simulated spectra generated from the MXQET simulation program, based on a model incorporating nearest-neighbor jumps from positions on the vertices of a truncated icosahedron (soccer-ball shape). The lower molecular-mass samples, influenced by the presence of more chain ends, showed more heterogeneity (broader distribution) and lower glass transitions …


Conformal Internal Coating Of Macroporous Co-Continuous Mcf-Silicas With Isocyanate Derived Polymers, Nicholas Leventis, Chariklia Sotiriou-Leventis, Xiaojiang Wang, Sudhir Mulik Jan 2006

Conformal Internal Coating Of Macroporous Co-Continuous Mcf-Silicas With Isocyanate Derived Polymers, Nicholas Leventis, Chariklia Sotiriou-Leventis, Xiaojiang Wang, Sudhir Mulik

Chemistry Faculty Research & Creative Works

Since their discovery in 1992,1,2 templating sol-gel silica with structuredirecting agents has resulted in new materials with ordered mesoporous (2-50 nm) structure that is investigated for application in areas as diverse as high surface area supports for caralysts or as nanostructured drug storage and release platforms.3 Structure-directing agents are typically surfactants ranging from cationic detergents such as alkyl-trimethylammonium salts with C8-C18 hydrocarbon chains to non-ionic tertiary amines, polyethylene oxide or amphiphilic triblock copolymers such as poly(ethyleneoxide)-blockpoly( propyleneoxide)-block-poly(ethyleneoxide) (e.g., Pluronic P123). Depending on the surfactant and the conditions (e.g., kind and concentration of catalyst) the structure of the mesopores may vary …


Effect Of Processing Conditions On Chemical Makeup Of Di-Isocyanate Crosslinked Silica Aerogels, Mary Ann B. Meador, Nicholas Leventis, Lynn A. Capadona, Plousia Vassilaras Jan 2006

Effect Of Processing Conditions On Chemical Makeup Of Di-Isocyanate Crosslinked Silica Aerogels, Mary Ann B. Meador, Nicholas Leventis, Lynn A. Capadona, Plousia Vassilaras

Chemistry Faculty Research & Creative Works

Sol-gel derived silica aerogels are attractive candidates for many unique thermal, optical, catalytic, and chemical applications1 because of their low density and high mesoporosity. However, their inherent fragility has restricted their use to, for example, insulation in extreme temperature environments such as Mars. We have previously reported crosslinking the mesoporous silica structure of an aerogel with di-isocyanates reacted with silanols on the surface,2,3 or epoxies reacting with an amine decorated silica surface.4 Either approach has been shown to significantly increase the strength of the aerogel with only a small effect on density or porosity. Thus, these hybrid materials may be …


Segmental Dynamics In Poly(Methyl Acrylate) On Silica: Molecular-Mass Effects, Burak Metin, Frank D. Blum Jan 2006

Segmental Dynamics In Poly(Methyl Acrylate) On Silica: Molecular-Mass Effects, Burak Metin, Frank D. Blum

Chemistry Faculty Research & Creative Works

The effect of molecular mass on the segmental dynamics of poly(methyl acrylate) (PMA) adsorbed on silica was studied using deuterium quadrupole-echo nuclear magnetic resonance (NMR) and modulated differential scanning calorimetry. Samples adsorbed on silica (all about 1.5 mg PMA/m2 silica) were shown to have more restricted segmental mobility, and higher Tg's, than the corresponding bulk PMA samples. Around the glass-transition region, adsorbed samples exhibited segmental mobility, which could be classified as heterogeneous due to a superposition of more-mobile and less-mobile components present in the deuterium NMR spectra. This heterogeneity was consistent with a motional gradient with more-mobile segments near the …


Generalized Distance Metric As A Robust Similarity Measure For Mobile Object Trajectories, Garima Pathak, Sanjay Kumar Madria, Spandan Tiwari Jan 2006

Generalized Distance Metric As A Robust Similarity Measure For Mobile Object Trajectories, Garima Pathak, Sanjay Kumar Madria, Spandan Tiwari

Computer Science Faculty Research & Creative Works

In this paper, we propose a novel generalized distance metric based on a model that incorporates the time axis explicitly. The proposed metric is based fundamentally on the Mahalanobis distance metric, which eliminates the correlation and scaling errors in similarity searches on trajectory databases. We propose the incorporation of a weight matrix in the proposed distance metric, which allows for easy manipulation of the degree of significance of the different spatial and or temporal dimensions.


Fermion Condensation In A Relativistic Degenerate Star: Arrested Collapse And Macroscopic Equilibrium [Post-Print], Mark P. Silverman Jan 2006

Fermion Condensation In A Relativistic Degenerate Star: Arrested Collapse And Macroscopic Equilibrium [Post-Print], Mark P. Silverman

Faculty Scholarship

Fermionic Cooper pairing leading to the BCS-type hadronic superfluidity is believed to account for periodic variations ("glitches") and subsequent slow relaxation in spin rates of neutron stars. Under appropriate conditions, however, fermions can also form a Bose–Einstein condensate of composite bosons. Both types of behavior have recently been observed in tabletop experiments with ultra-cold fermionic atomic gases. Since the behavior is universal (i.e., independent of atomic potential) when the modulus of the scattering length greatly exceeds the separation between particles, one can expect analogous processes to occur within the supradense matter of neutron stars. In this paper, I show how …


Solvent-Free Preparation Of Primary Carbamates, Ali Reza Modarresi-Alam, Mohsen Rostamizadeh, Parisa Najafi Jan 2006

Solvent-Free Preparation Of Primary Carbamates, Ali Reza Modarresi-Alam, Mohsen Rostamizadeh, Parisa Najafi

Turkish Journal of Chemistry

Herein, we describe a simple and efficient method for the conversion of compounds containing a hydroxyl group to primary carbamates at room temperature with excellent yield and purity, and without any epimerization, in the absence of solvent.


Thermal And Mechanical Effects Of A Shallow Asthenosphere In The Acadian Orogen: An Investigation Through Numerical Modeling, Lucy E. Brown Jan 2006

Thermal And Mechanical Effects Of A Shallow Asthenosphere In The Acadian Orogen: An Investigation Through Numerical Modeling, Lucy E. Brown

Electronic Theses and Dissertations

A high-temperature region associated with Acadian deformation extends 200 km through north-central New England. The scale of this heat source is investigated in order to better understand the rheology and mechanics of deforming orogens. In central Maine, on the boundary of the high-temperature region, isograds in pelitic rocks are normal to the accretionary structures and record a steep northeast-southwest thermal gradient. The isogradic sequence, geobarometry, and the mineral assemblages indicate low-pressure, high-temperature metamorphism, moderately low pressures of 3 kbar, and temperatures ranging from 600º to 450ºC over a 10 km region. The spacing between these isograds and the temperature at …


History Of The Department Of Mathematical Sciences At The University Of Montana: A Collection Of Interviews, Varoujan Bedros, Daniel F. Finch, Charles Myers, Merry Rampy, Johnny W. Lott (Editor) Jan 2006

History Of The Department Of Mathematical Sciences At The University Of Montana: A Collection Of Interviews, Varoujan Bedros, Daniel F. Finch, Charles Myers, Merry Rampy, Johnny W. Lott (Editor)

History of the Department of Mathematical Sciences at UM: A Collection of Interviews

A collection of transcribed oral history interviews conducted in 1999 with current and recently retired faculty members of the Department of Mathematics.


Reconstructing Sea-Level Change From The Internal Architecture Of Stromatolite Reefs: An Example From The Mesoproterozoic Sulky Formation, Dismal Lakes Group, Arctic Canada, L C. Kah, Julie K. Bartley, Tracy D. Frank, Timothy W. Lyons Jan 2006

Reconstructing Sea-Level Change From The Internal Architecture Of Stromatolite Reefs: An Example From The Mesoproterozoic Sulky Formation, Dismal Lakes Group, Arctic Canada, L C. Kah, Julie K. Bartley, Tracy D. Frank, Timothy W. Lyons

Department of Earth and Atmospheric Sciences: Faculty Publications

The Mesoproterozoic Dismal Lakes Group, arctic Canada, contains a relatively thin, yet regionally extensive stromatolitic reef complex that developed subtidally during a major transgression, shoaled to sea level, and was overlain by intertidal to supratidal carbonate and evaporite strata. The September Lake reef complex exhibits a complex internal architecture that records the interaction between stromatolite growth and changes in accommodation space derived from both higher order (4th- or 5th-order, parasequence-scale) changes in sea level and the variable bathymetry of the sea floor. Reef growth, which was initiated during three sea-level cycles, records progressive marine transgression over depositional lows that were …


Burrows Dug By Large Vertebrates Into Rain-Moistened Middle Jurassic Sand Dunes, David B. Loope Jan 2006

Burrows Dug By Large Vertebrates Into Rain-Moistened Middle Jurassic Sand Dunes, David B. Loope

Department of Earth and Atmospheric Sciences: Faculty Publications

In south-central Utah, eolian cross-strata of the Escalante Member of the Entrada Sandstone contain inclined, cylindrical burrows up to 63 cm in diameter and 305 cm long. Of the 14 large tunnels located during this study, 12 descend from second- and third-order bounding surfaces that formed on the lee slopes of large dune ridges, well above the water table. The tunnels are inclined 15°–22°; one tunnel ends in an expanded chamber. Eolian cross-strata fill proximal portions of four of the tunnels and indicate that after abandonment, sand drifts migrated as much as a meter into the open shafts. Structureless sand …


On Doubly Periodic Solutions Of Quasilinear Hyperbolic Equations Of The Fourth Order, T. Kiguradze, T. Smith Jan 2006

On Doubly Periodic Solutions Of Quasilinear Hyperbolic Equations Of The Fourth Order, T. Kiguradze, T. Smith

Publications

The problem on doubly periodic solutions is considered for a class of quasilinear hyperbolic equations. Effective sufficient conditions of solvability and unique solvability of this problem are established.


Red Rock Desert Learning Center & Wild Horse And Burro Facility: Newsletter, Red Rock Desert Learning Center Jan 2006

Red Rock Desert Learning Center & Wild Horse And Burro Facility: Newsletter, Red Rock Desert Learning Center

Oliver Ranch Project

The mission of the Red Rock Desert Learning Center is to instill stewardship and respect by increasing knowledge and understanding of the Mojave Desert ecosystems
and cultures through a unique experiential discovery program.


Red Rock Desert Learning Center & Wild Horse And Burro Facility: Historical Timeline, Red Rock Desert Learning Center Jan 2006

Red Rock Desert Learning Center & Wild Horse And Burro Facility: Historical Timeline, Red Rock Desert Learning Center

Oliver Ranch Project

Historical Timeline of Red Rock Desert Learning Center.


Explorations In Off-Higway Vehicle (Ohv) Recreation: A High School Driver Education Extension, Allison Brody, Jennell M. Miller, Sky Mcclain, Katharine August Jan 2006

Explorations In Off-Higway Vehicle (Ohv) Recreation: A High School Driver Education Extension, Allison Brody, Jennell M. Miller, Sky Mcclain, Katharine August

Education about the Environment

The lessons within this curriculum have been designed to meet the following goals:

● To increase knowledge about the natural world OHV recreationists will encounter in their exploration of Southern Nevada;

● To increase knowledge of responsible use of OHVs and principles of Tread Lightly! and Leave No Trace (both are nonprofit organizations dedicated to increasing awareness about how to minimize impacts while enjoying public and private lands);

● To increase awareness, knowledge, and understanding of land ethics;

● To allow youth to analyze personal values regarding recreational experiences, including OHV use.


Finicky Fish Finish... Last! Pre-Visit Lessons -- Support Materials (Grade 5), Discover Mojave: Forever Earth Jan 2006

Finicky Fish Finish... Last! Pre-Visit Lessons -- Support Materials (Grade 5), Discover Mojave: Forever Earth

Curriculum materials (FE)

In “Finicky Fish Finish…Last!” students explore what has happened to the Colorado River and the reasons why it is so difficult for the razorback sucker to thrive in a changed environment. Working as ichthyologists (fish biologists) at Lake Mead, students collect water quality data such as temperature, pH, and clarity -- to determine whether current habitat conditions are sufficient for survival of young razorback suckers. Students observe and identify non-native fish in Lake Mead as they learn how the razorback sucker interacts with these neighbors. Students assess whether Lake Mead is still a good habitat for razorback suckers. Using the …


Our Places To Tell Stories: Making Connections With Our Audiences, Public Lands Institute Jan 2006

Our Places To Tell Stories: Making Connections With Our Audiences, Public Lands Institute

Our Places to Tell Stories

The idea for an annual Our Places Tell Stories conference was prompted by discussions that took place within a unique partnership of federal, state, university, and public organizations in southern Nevada. Members identified the need to share and learn from successful educational and interpretive strategies. Our increasingly urban surroundings and rapidly changing populations hinder personal connections between people and their natural environment. However, the right tools and techniques will help us inspire children and adults to understand, value, and take care of our shared natural places.

This first conference supports professionals in creating and evaluating effective educational programs and interpretive …


Oliver Ranch Science School Complex & Wild Horse And Burro Facility: Annual Progress Report, Year Ending June 30, 2006, Margaret N. Rees Jan 2006

Oliver Ranch Science School Complex & Wild Horse And Burro Facility: Annual Progress Report, Year Ending June 30, 2006, Margaret N. Rees

Oliver Ranch Project

Assist in project coordination between numerous stakeholders such as the Clark County School System, Desert Research Institute, Community College of Southern Nevada, UNR Cooperative Extension, Nevada State College, local museums, state parks, non-profit organizations, federal agencies, and the public to ensure appropriate educational curricular activities and venues are provided for in the conceptual design of the School and the Wild Horse and Burro facility where appropriate as well as assist in the NEPA process as needed. The activities will be conducted at least in part by university faculty, staff and students as part of the university’s research, teaching, and service …


Oliver Ranch Science School Complex & Wild Horse And Burro Facility: Quarterly Progress Report, Period Ending September 30, 2006, Margaret N. Rees Jan 2006

Oliver Ranch Science School Complex & Wild Horse And Burro Facility: Quarterly Progress Report, Period Ending September 30, 2006, Margaret N. Rees

Oliver Ranch Project

Assist in project coordination between numerous stakeholders such as the Clark County School System, Desert Research Institute, Community College of Southern Nevada, UNR Cooperative Extension, Nevada State College, local museums, state parks, non-profit organizations, federal agencies, and the public to ensure appropriate educational curricular activities and venues are provided for in the conceptual design of the School and the Wild Horse and Burro facility where appropriate as well as assist in the NEPA process as needed. The activities will be conducted at least in part by university faculty, staff and students as part of the university’s research, teaching, and service …


Oliver Ranch Science School Complex & Wild Horse And Burro Facility: Quarterly Progress Report, Period Ending March 31, 2006, Margaret N. Rees Jan 2006

Oliver Ranch Science School Complex & Wild Horse And Burro Facility: Quarterly Progress Report, Period Ending March 31, 2006, Margaret N. Rees

Oliver Ranch Project

Executive Summary

Activity highlights during the third quarter of Year Two include the following actions toward task agreement deliverables:

  • Agenda and minutes prepared and distributed for Core Group meetings on January 17 and March 21, 2006.
  • Cultural curriculum 100% completed
  • Night Sky curriculum 100% completed.
  • Green Building curriculum 75% completed.
  • Native American Correlations 75% completed.
  • Teacher piloting workshops held on February 23, March 18, and March 25, 2006 at Spring Mountain Ranch State Park and the Oliver Ranch site.
  • RRDLC newsletter completed.
  • Website content, navigation, and graphics updated and improved.


Learning About The Natural World Through An Inquiry-Based Residential Experience, Red Rock Desert Learning Center Jan 2006

Learning About The Natural World Through An Inquiry-Based Residential Experience, Red Rock Desert Learning Center

Oliver Ranch Project

The mission of the Red Rock Desert Learning Center is to instill stewardship and respect by increasing knowledge and understanding of the Mojave Desert ecosystems and cultures through a unique experiential discovery program