Physical Sciences and Mathematics Commons^™

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

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

John W. Fraas

No abstract provided.

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

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

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

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

Nat Quansah

No abstract provided.

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

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

Gabriel A. Moreno

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

Joshua M. Pearce

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

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

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

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

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.

Highly Anisotropic Crystal Growth And Thermoelectric Properties Of K2bi8_Xsbxse13 Solid Solutions: Band Gap Anomaly At Low X, Jeffrey S. Dyck, Theodora Kyratsi, Wei Chan, Duck-Young Chung, Ctirad Uher, Konstantinos Paraskevopoulos, Mercouri Kanatzidis

Jeffrey Dyck

The thermoelectric properties of solid solutions of the type B -K2Bi8_xSbxSe13 (0

Why Lawyers Should Care, John C. Dernbach

John C. Dernbach

No abstract provided.

Oral History Interview With Carl Machover, Philip L. Frana

Philip L Frana

Carl Machover is computer graphics pioneer and president of Machover Associates Corporation (MAC), a computer graphics consultancy founded in 1976. MAC provides a broad range of management, engineering, marketing, and financial services to computer graphics users, suppliers, and investors worldwide. In this oral history Machover describes his upbringing in Iowa and training in the Eddy radar and radio program and other Navy service schools in Mississippi and Texas. He also provides details of his education under ...

Infrared Spectroscopy Of Aniline–Ne Clusters And The Corresponding Cluster Cations In The Nh2-Stretching Vibration Region, Naveed Piracha, T. Nakanaga

Naveed K. Piracha

The vibrational spectra of the NH2-stretching modes of aniline–Ne and aniline–Ne+ have been measured using infrared depletion spectroscopy and REMPI–TOF mass spectrometry. In the NH2-stretching vibration region of the aniline–Ne clusters, two absorption bands at 3422 and 3508cm−1 were observed. The frequency shifts from the monomer was found to be negligibly small. As for the aniline–Ne+ cluster cations, the observed frequencies of the vibrational modes were 3394 and 3488cm−1. These values agreed with ones observed for aniline–Ar+ cluster within the error limit. This fact suggests that the effect of neon to aniline in forming the cluster is not significant in …

Packaging And Deploying Predictable Assembly, Scott A. Hissam, Gabriel A. Moreno, Judith Stafford, Kurt C. Wallnau

Gabriel A. Moreno

Significant economic and technical benefits accrue from the use of pre-existing and commercially available software components to develop new systems. However, challenges remain that, if not adequately addressed, will slow the adoption of software component technology. Chief among these are a lack of consumer trust in the quality of components, and a lack of trust in the quality of assemblies of components without extensive and expensive testing. This paper describes predictionenabled component technology (PECT). A PECT results from integrating component technology with analysis models. An analysis model permits analysis and prediction of assembly-level properties prior to component composition, and, perhaps, …

Thermal-Lens Model Compared With The Sheik-Bahae Formalism In Interpreting Z-Scan Experiments On Lyotropic Liquid Crystals, Fabio Luiz Sant'anna Cuppo, Antonio Martins Figueiredo Neto, Sergio Leonardo Gomez, Peter Palffy-Muhoray

Peter Palffy-Muhoray

We carried out Z-scan measurements on lyotropic liquid crystals and on lyotropic liquid crystals doped with ferrofluid. In these experiments, the sample is translated through the focal region of a focused Gaussian laser beam. The dependence of the far-field intensity on sample position due to intensity-dependent optical nonlinearities has been analyzed on the basis of the thermal-lens model of Gordon et al. and the Gaussian decomposition analysis of Sheik-Bahae et al. The thermal-lens model is nonlocal in space and time, whereas the Gaussian decomposition is predicated on a strictly local response. We compare the goodness of fit of the predictions …

The Blups Are Not “Best” When It Comes To Bootstrapping, Jeffrey S. Morris

Jeffrey S. Morris

In the setting of mixed models, some researchers may construct a semiparametric bootstrap by sampling from the best linear unbiased predictor residuals. This paper demonstrates both mathematically and by simulation that such a bootstrap will consistently underestimate the variation in the data in finite samples.

Oral History Interview With Lee Keet, Philip L. Frana

Philip L Frana

In this oral history software entrepreneur Ernest E.(Lee) Keet chronicles his education in programming and engineering at Cornell University, his early work as a salesperson and systems engineer for IBM in White Plains, NY, and his success as founder and CEO of Turnkey Systems, Inc.(TSI). Keet characterizes the heavy" craft" versus the" art" components of computer programming; he discusses the introduction of TSI's Task/Master, the first commercial telecommunications monitor; and his entrepreneurial efforts in Europe. Keet ...

Direct And Sensitive Measurement Of Two-Photon Absorption Cross Sections, Peifang Tian, D. Keusters, Warren Warren

Peifang Tian

Summary form only given. We present a direct method to detect weak two-photon absorption (TPA) signals. As a proof of principle, we have measured the TPA cross section δ for rhodamine 6G (R6G) in methanol and obtained a value which agrees with other results. The technique may be very useful in biomedical imaging.

Statistical Models For Empirical Component Properties And Assembly-Level Property Predictions: Toward Standard Labeling, Gabriel A. Moreno, Scott A. Hissam, Kurt C. Wallnau

Gabriel A. Moreno

One risk inherent in the use of software components has been that the behavior of assemblies of components is discovered only after their integration. The objective of our work is to enable designers to use known (and certified) component properties as parameters to models that can be used to predict assembly-level properties. Our concern in this paper is with empirical component properties and compositional reasoning, rather than formal properties and reasoning. Empirical component properties must be measured; assessing the effectiveness of predictions based on these properties also involves measurement. This, in turn, introduces systematic and random measurement error. As a …

Photovoltaics — A Path To Sustainable Futures, Joshua M. Pearce

Joshua M. Pearce

Multiscalar, Multisensor Search And Survey With Hovering Auvs, Christopher Roman, Hanumant Singh

Christopher N. Roman

No abstract provided.