Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Selected Works

2002

Discipline
Keyword
Publication
File Type

Articles 1 - 30 of 113

Full-Text Articles in Physical Sciences and Mathematics

A Soap-Oriented Component-Based Framework Supporting Device-Independent Multimedia Web Services, Jia Zhang, Jen-Yao Chung Nov 2002

A Soap-Oriented Component-Based Framework Supporting Device-Independent Multimedia Web Services, Jia Zhang, Jen-Yao Chung

Jia Zhang

No abstract provided.


Quantitative Evaluation Of Hiv Preventon Programs, Edward Kaplan, Ron Brookmeyer Nov 2002

Quantitative Evaluation Of Hiv Preventon Programs, Edward Kaplan, Ron Brookmeyer

Ron Brookmeyer

How successful are HIV prevention programs? Which HIV prevention programs are most cost effective? Which programs are worth expanding and which should be abandoned altogether? This book addresses the quantitative evaluation of HIV prevention programs, assessing for the first time several different quantitative methods of evaluation


Prevention Of Inhalational Anthrax In The U.S. Outbreak, Ron Brookmeyer, Natalie Blades Nov 2002

Prevention Of Inhalational Anthrax In The U.S. Outbreak, Ron Brookmeyer, Natalie Blades

Ron Brookmeyer

No abstract provided.


Applications Of Underground Structures For The Protection Of Critical Infrastructure, George H. Baker, Richard G. Little, Don A. Linger Nov 2002

Applications Of Underground Structures For The Protection Of Critical Infrastructure, George H. Baker, Richard G. Little, Don A. Linger

George H Baker

The U.S. President’s Commission on Critical Infrastructure Protection (PCCIP), convened in the wake of the bombing of the Murrah Federal Building in Oklahoma City, concluded that the nation’s physical security and economic security depend on our critical energy, communications, and computer infrastructures. While a primary motivating event for the establishment of the commission was the catastrophic physical attack of the Murrah Building, it is ironic that the commission focused its attention primarily on cyber threats. Their rationale was that cyber vulnerabilities posed a new, unaddressed challenge to infrastructure security. This approach was further questioned by the events of September 11, …


Supervisory Control And Data Acquisition (Scada) Systems, George H. Baker, Allan Berg Nov 2002

Supervisory Control And Data Acquisition (Scada) Systems, George H. Baker, Allan Berg

George H Baker

Our critical national infrastructure systems have become almost universally dependent upon computer-based control systems technically referred to as supervisory control and data acquisition (SCADA) systems. SCADA systems evolved from the telemetry and event-alarm systems developed in the early days of utilities. With the widespread use of SCADA systems, computers have become the "basis element" for much of our critical infrastructure. Thus, the disruption of controlling computer terminals and networks due to natural disasters, electric power failure, accidents or malicious activity can have catastrophic consequences.


A Convenient One-Pot, Organoaluminum Mediated Vinylsilane Synthesis From Non-Enolizable Ketones Via The Peterson Protocol, Man Lung Kwan, Merle Battiste Nov 2002

A Convenient One-Pot, Organoaluminum Mediated Vinylsilane Synthesis From Non-Enolizable Ketones Via The Peterson Protocol, Man Lung Kwan, Merle Battiste

Man Lung Desmond Kwan

Vinylsilanes serve as convenient vinyl anion equivalents which have gained popularity over decades. A variety of non-enolizable aromatic ketones are converted to the corresponding vinylsilanes in a one-pot procedure involving the addition of (trimethylsilylmethyl)lithium to aromatic ketones followed by addition of diethylaluminum chloride and then small amounts of water. Halide and alkoxide substituents are tolerated, and this trans-stereoselective (broad generalization; the most sterically bulky group on the double bond is trans to the trimethylsilyl group) reaction affords vinylsilanes in good yield.


Oral History Interview With Laszlo A. Belady, Philip L. Frana Nov 2002

Oral History Interview With Laszlo A. Belady, Philip L. Frana

Philip L Frana

Belady discusses his early life and education in Hungary, escape to West Germany during the 1956 revolution, and work as a draftsman at Ford Motor Company in Cologne and as an aerodynamics engineer at Dassault in Paris. Belady covers his 1961 immigration into the United States, where he joined International Business Machines and did early work in operating systems, virtual machine architectures, program behavior modeling, memory management, computer graphics, Asian character sets, and data security. He also ...


Structure, Wettability, And Reductive Desorption Of Self-Assembled Monolayers Of Positional Isomers Of (12-Mercaptododecyl)Phenol, Francisco Cavadas, Mark Anderson Nov 2002

Structure, Wettability, And Reductive Desorption Of Self-Assembled Monolayers Of Positional Isomers Of (12-Mercaptododecyl)Phenol, Francisco Cavadas, Mark Anderson

Mark R. Anderson

No abstract is currently available.


Asymptotic Solitons For A Higher-Order Modified Korteweg–De Vries Equation, T. Marchant Oct 2002

Asymptotic Solitons For A Higher-Order Modified Korteweg–De Vries Equation, T. Marchant

Tim Marchant

Solitary wave interaction for a higher-order modified Korteweg–de Vries (mKdV) equation is examined. The higher-order mKdV equation can be asymptotically transformed to the mKdV equation, if the higher-order coefficients satisfy a certain algebraic relationship. The transformation is used to derive the higher-order two-soliton solution and it is shown that the interaction is asymptotically elastic. Moreover, the higher-order phase shifts are derived using the asymptotic theory. Numerical simulations of the interaction of two higher-order solitary waves are also performed. Two examples are considered, one satisfies the algebraic relationship derived from the asymptotic theory, and the other does not. For the example …


Molecular Dynamics Simulations Of Sodium Dodecyl Sulfate Micelle In Water: The Behavior Of Water, Chrystal Bruce, Sanjib Senapati, Max Berkowitz, L. Perera, M. Forbes Oct 2002

Molecular Dynamics Simulations Of Sodium Dodecyl Sulfate Micelle In Water: The Behavior Of Water, Chrystal Bruce, Sanjib Senapati, Max Berkowitz, L. Perera, M. Forbes

Chrystal D. Bruce

Using a 5 ns explicit atom molecular dynamics simulation of a 60 monomer sodium dodecyl sulfate micellar system containing 7579 TIP3P water molecules, the behavior of water in different electrostatic environments was examined. Structural evaluation of the system revealed that penetration of water molecules into the micelle was restricted to the headgroup region, leaving a 12 Å water-free hydrocarbon core. Water molecules near the headgroup exhibit a distortion of the water−water hydrogen bonding network due to headgroup oxygen−water hydrogen bond formation. The dynamic implications of this distortion are manifested in the decay of the dipole autocorrelation function, Φ(t) and translational …


Polarization From Microlensing Of Spherical Circumstellar Envelopes By A Point Lens., J. F. L. Simmons, J. E. Bjorkman, R. Ignace, I. J. Coleman Oct 2002

Polarization From Microlensing Of Spherical Circumstellar Envelopes By A Point Lens., J. F. L. Simmons, J. E. Bjorkman, R. Ignace, I. J. Coleman

Richard Ignace

We discuss the flux and polarization signals obtained from the microlensing of stars with extended circumstellar envelopes by a single point-mass lens. A previous paper considered the case of main-sequence stars, and showed that microlensing of the stellar photosphere could produce a small net polarization (up to 0.1 per cent). In this paper, we show that stars with extensive envelopes will show a much higher level of variable polarization (up to 10 per cent), even if they are spherically symmetric. Since the stellar envelopes most likely to be lensed are produced by red giant winds, we also investigate the effects …


Application Of Steaming Video And Flash Animation For Teaching Analytical Chemistry, Mark Anderson Oct 2002

Application Of Steaming Video And Flash Animation For Teaching Analytical Chemistry, Mark Anderson

Mark R. Anderson

No abstract is currently available.


A Mathematical Model Of Bacterial Aerotaxis, Borbala Mazzag, Alex Mogilner Sep 2002

A Mathematical Model Of Bacterial Aerotaxis, Borbala Mazzag, Alex Mogilner

Borbala Mazzag

No abstract provided.


On Porosity Prediction From Seismic Data In Ghawar Field, Saudi Arabia, Thomas M. Loretto Sep 2002

On Porosity Prediction From Seismic Data In Ghawar Field, Saudi Arabia, Thomas M. Loretto

Thomas M Loretto

No abstract provided.


Expressing Logistic Regression Coefficients As Changes In Initial Probability Values: Useful Information For Practitioners, John Fraas, J Michael Drushal, Jef Graham Sep 2002

Expressing Logistic Regression Coefficients As Changes In Initial Probability Values: Useful Information For Practitioners, John Fraas, J Michael Drushal, Jef Graham

John W. Fraas

No abstract provided.


Heat Transport In Sb2àXvxte3 Single Crystals, Jeffrey Dyck, W. Chen, C. Uher, Č. DrašAr, P. LošŤÁK Sep 2002

Heat Transport In Sb2àXvxte3 Single Crystals, Jeffrey Dyck, W. Chen, C. Uher, Č. DrašAr, P. LošŤÁK

Jeffrey Dyck

Antimony telluride doped with small concentrations of vanadium was recently identified as a diluted magnetic semiconductor. We present a study of the heat transport in single crystals of [formula] with [formula] 0.01, 0.02, and 0.03. Thermopower and thermal conductivity were measured from 1.5 K to 300 K. The thermopower is positive for all samples investigated and has a modest dependence on vanadium content. At low temperatures, the lattice thermal conductivity has an approximate [formula] dependence and the data up to 100 K can be fitted well assuming that phonons scatter on boundaries, point defects, charge carriers, and other phonons. Theoretical …


Calorimetric Study Of Nematic Prewetting, Xuewu Liu, David W. Allender, D. Finotello Sep 2002

Calorimetric Study Of Nematic Prewetting, Xuewu Liu, David W. Allender, D. Finotello

David W Allender

We report specific-heat measurements for a series of liquid crystals imbedded in a porous cylindrical geometry. Above the nematic-to-isotropic transition and dependent on nematic width (or chain length), the specific heat shows a small peak. In analogy to known ellipsometry results, the peak is believed to be the signature of a nematic prewetting transition.


Researching The History Of Software: Mining Internet Resources In The “Old World,”“New World,” And The “Wild West”, Juliet Burba, Philip L. Frana Sep 2002

Researching The History Of Software: Mining Internet Resources In The “Old World,”“New World,” And The “Wild West”, Juliet Burba, Philip L. Frana

Philip L Frana

So wrote the great philosopher and poet Jorge Augustín Nicolás Ruiz de Santayana in his essay" The Elements and Function of Poetry."[1] Without doubt, the advent of the early Web unleashed a mania, an unreasonable recklessness that to this day resists being swept back under the rug. How can we tease" sanity" out of the Web? Can the historian put this madness to good use?


Studies Of The Relationship Between The Structure And Properties Of Interfacial Thin Films, Mark Anderson Sep 2002

Studies Of The Relationship Between The Structure And Properties Of Interfacial Thin Films, Mark Anderson

Mark R. Anderson

No abstract is available at this time.


‘A View From Johannesburg.’ Daily Reports On The World Summit On Sustainable Development, Nat Quansah Aug 2002

‘A View From Johannesburg.’ Daily Reports On The World Summit On Sustainable Development, Nat Quansah

Nat Quansah

No abstract provided.


The Seabed Auv — A Platform For High Resolution Imaging, Hanumant Singh, Ryan Eustice, Christopher Roman, Oscar Pizarro Aug 2002

The Seabed Auv — A Platform For High Resolution Imaging, Hanumant Singh, Ryan Eustice, Christopher Roman, Oscar Pizarro

Christopher N. Roman

No abstract provided.


Ultrafast Measurement Of Two-Photon Absorption By Loss Modulation, Peifang Tian, Warren Warren Aug 2002

Ultrafast Measurement Of Two-Photon Absorption By Loss Modulation, Peifang Tian, Warren Warren

Peifang Tian

We demonstrate a direct and sensitive technique for measuring two-photon absorption (TPA).An intensity- modulated femtosecond laser beam passes through a sample exhibiting TPA.A TPA signal at twice the modulation frequency is then generated and subsequently measured by a lock-in amplifier. The absolute TPA cross section of Rhodamine 6G at 800nm is found to be 15.32.010 -50 cm 4 s / photon and agrees well with previously published results obtained with much higher intensity [J.Chem.Phys. 112, 9201 (2000)]. Our method may be especially useful in measuring nonlinear absorptions of nonfluorescent materials.


Predictable Assembly Of Substation Automation Systems: An Experiment Report, Scott A. Hissam, John Hudak, James Ivers, Mark H. Klein, Magnus Larsson, Gabriel A. Moreno, Linda M. Northrop, Daniel Plakosh, Judith Stafford, Kurt C. Wallnau, William G. Wood Aug 2002

Predictable Assembly Of Substation Automation Systems: An Experiment Report, Scott A. Hissam, John Hudak, James Ivers, Mark H. Klein, Magnus Larsson, Gabriel A. Moreno, Linda M. Northrop, Daniel Plakosh, Judith Stafford, Kurt C. Wallnau, William G. Wood

Gabriel A. Moreno

The Predictable Assembly from Certifiable Components (PACC) Initiative at the Software Engineering Institute (SEI) is developing methods and technologies for predictable assembly. A software development activity that builds systems from components is predictable if the runtime behavior of an assembly of components can be predicted from known properties of components and their patterns of interactions (connections), and if these predictions can be objectively validated. A component is certifiable if these known properties can be obtained or validated by independent third parties. The SEI's technical approach to PACC rests on prediction-enabled component technology (PECT). At the highest level, PECT is a …


Infrared Depletion Spectroscopy Of Aniline-Acetonitrile Cation And Aniline-Acetonitrile-Water Cation Clusters, H. Nagai, Naveed Piracha, T. Nakanaga Aug 2002

Infrared Depletion Spectroscopy Of Aniline-Acetonitrile Cation And Aniline-Acetonitrile-Water Cation Clusters, H. Nagai, Naveed Piracha, T. Nakanaga

Naveed K. Piracha

The vibrational spectra of the aniline-acetonitrile^+ and the aniline-acetonitrile-water^+ cluster cations have been measured by the infrared depletion spectroscopy in the frequency region of NH and OH stretching vibrations. One absorption band was observed at 3437cm^-^1 in the infrared spectrum of the aniline-acetonitrile^+ cluster cation, and was assigned to the NH stretching vibration of free NH of aniline. As for the aniline-water-acetonitrile^+ cluster cation, three absorptions were observed at 3722, 3634 and 3247cm^-^1, which were assigned to the anti-symmetric stretching and symmetric stretching vibrations of OH of water and the stretching vibrations of NH bond interacting with water, respectively. In …


Maximization Of The Open Circuit Voltage For Hydrogenated Amorphous Silicon N–I–P Solar Cells By Incorporation Of Protocrystalline Silicon P-Type Layers, R. J. Koval, Chi Chen, G. M. Ferreira, A. S. Ferlauto, Joshua M. Pearce, P. I. Rovira, C. R. Wronski, R. W. Collins Aug 2002

Maximization Of The Open Circuit Voltage For Hydrogenated Amorphous Silicon N–I–P Solar Cells By Incorporation Of Protocrystalline Silicon P-Type Layers, R. J. Koval, Chi Chen, G. M. Ferreira, A. S. Ferlauto, Joshua M. Pearce, P. I. Rovira, C. R. Wronski, R. W. Collins

Joshua M. Pearce

In studies of hydrogenated amorphous silicon(a-Si:H) n–i–psolar cells fabricated by rf plasma-enhanced chemical vapor deposition (PECVD), we have found that the maximum open circuit voltage (Voc) is obtained by incorporating p-type doped Si:H layers that are protocrystalline in nature. Specifically, these optimum p layers are prepared by PECVD in the a-Si:H growth regime using the maximum hydrogen-to-silane flow ratio possible without crossing the thickness-dependent transition into the mixed-phase (amorphous+microcrystalline) growth regime for the ∼200 Å p-layer thickness. The strong dependence of the p-layer phase and solar cell Voc on the underlying i-layer phase also confirms the protocrystalline nature of the …


The Enthalpy Of Vaporization And Sublimation Of Corannulene, Coronene, And Perylene At T = 298.15 K, James S. Chickos, Paul Webb, Gary Nichols, Tetsu Kiyobayashi, Pei-Chao Cheng, Lawrence Scott Jul 2002

The Enthalpy Of Vaporization And Sublimation Of Corannulene, Coronene, And Perylene At T = 298.15 K, James S. Chickos, Paul Webb, Gary Nichols, Tetsu Kiyobayashi, Pei-Chao Cheng, Lawrence Scott

James Chickos

No abstract provided.


Oral History Interview With Peter Watson, Philip L. Frana Jul 2002

Oral History Interview With Peter Watson, Philip L. Frana

Philip L Frana

Peter Watson is founder of Berkeley Computer Services Limited (BCS), one of the oldest continuously operating software houses in Scotland. The company was established in 1978, and is based in Glasgow. BCS's first customer was Kangolwear. The company moved into healthcare solutions in the 1980s. In 1991 the company launched the integrated software package Masterlab, first implemented at Neville Hall Hospital in Abergavenny, Wales. In 2002 BCS was one of the largest providers of laboratory information systems in the United ...


Oral History Interview With Charles Antony Richard Hoare, Philip L. Frana Jul 2002

Oral History Interview With Charles Antony Richard Hoare, Philip L. Frana

Philip L Frana

Sir Antony Hoare is Senior Researcher at Microsoft Research in Cambridge, England, and Research/Professor Emeritus at the University of Oxford. Hoare is the recipient of the AM Turing Award for fundamental contributions to the definition and design of programming languages. He has also been awarded the Kyoto Prize in Advanced Technology for pioneering and fundamental contributions to software science. In this oral history Hoare recounts his personal involvement in the development of academic computing science ...


Core Services In The Architecture Of The National Digital Library For Science Education (Nsdl), Carl Lagoze, Walter Hoehn, David Millman, William Arms, Stoney Gan, Diane Hillmann, Christopher Ingram, Dean Krafft, Richard Marisa, Jon Phipps, John Saylor, Carol Terrizzi, James Allan, Sergio Guzman-Lara, Tom Kalt Jul 2002

Core Services In The Architecture Of The National Digital Library For Science Education (Nsdl), Carl Lagoze, Walter Hoehn, David Millman, William Arms, Stoney Gan, Diane Hillmann, Christopher Ingram, Dean Krafft, Richard Marisa, Jon Phipps, John Saylor, Carol Terrizzi, James Allan, Sergio Guzman-Lara, Tom Kalt

James Allan

We describe the core components of the architecture for the (NSDL) National Science, Mathematics, Engineering, and Technology Education Digital Library. Over time the NSDL will include heterogeneous users, content, and services. To accommodate this, a design for a technical and organization infrastructure has been formulated based on the notion of a spectrum of interoperability. This paper describes the first phase of the interoperability infrastructure including the metadata repository, search and discovery services, rights management services, and user interface portal facilities.


Electrical Conductivity And Thermopower Of Cu–Sio[Sub 2] Nanogranular Films., W. Chen, J. Lin, X. Zhang, H. Shin, Jeffrey Dyck, C. Uher Jul 2002

Electrical Conductivity And Thermopower Of Cu–Sio[Sub 2] Nanogranular Films., W. Chen, J. Lin, X. Zhang, H. Shin, Jeffrey Dyck, C. Uher

Jeffrey Dyck

We have measured the thermopower S and electrical conductivity σ in a series of Cu[sub x](SiO[sub 2])[sub 1-x] nanogranular films between 2 and 300 K with Cu volume fraction x varying from 0.43 up to 1.0. At low temperatures, disorder-enhanced electron-electron interaction effects dictate the behavior of σ. A crossover of the temperature dependence from σ∝ √T to σ∝ T[sup 1/3] is observed as x is lowered and the metal-insulator transition is approached. S is small, shows linear temperature dependence, and is rather insensitive to the change of x. Effects of annealing are also discussed.