Physical Sciences and Mathematics Commons^™

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.

Review Of Frank Ryan: Tuberculosis: The Greatest Story Never Told, Lynn Margulis

Lynn Margulis (1938 - 2011)

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.

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

Magnetochemical Origin For Invar Anomalies In Iron-Nickel Alloys, V. Crisan, P. Entel, H. Ebert, H. Akai, Duane D. Johnson, J. B. Staunton

Duane D. Johnson

Zero- and finite-temperature (T) first-principles calculations versus composition (c) show that magnetochemical effects lead to Invar anomalies in Fe-(Ni, Co, Pt) alloys. Chemical short- or long-range order and negative interatomic exchange interaction of electrons in antibonding majority-spin states force the face-centered-cubic lattice to compete simultaneously for a smaller volume (from antiferromagnetic tendencies) and a larger volume (from Stoner ferromagnetic tendencies). The resulting additional negative lattice anharmonicity is very large for Fe-(Ni, Co) while absent for Fe-Pt. Our results explain the T- and c-dependent behavior of Invar properties, including the lattice softening and thermal expansion of Fe-Ni. In addition, the occurrence …

Longitudinal Ionosphericeffects In The South Atlantic Sector During Solar Maximum, E. R. De Paula, J. R. Souza, Bela G. Fejer, G. J. Bailey, R. A. Heelis

Bela G. Fejer

[1] Large-scale horizontal gradients in ion density and vertical drift observed by the Atmospheric Explorer E satellite in the South Atlantic region (latitudes 10°S–20°S, longitudes 50°W–10°E) during the June solstice at solar maximum are presented and analyzed. These features occur during the nighttime period. The observations near 450-km altitude show vertically downward ion drift velocities exceeding 120 m s−1 and depleted regions where the ion density is around 2 × 104 cm−3. It is shown, using values modeled by the Sheffield University Plasmasphere Ionosphere Model (SUPIM) along the satellite trajectory, that the large ion density depletions appear as a result …

Why Lawyers Should Care, John C. Dernbach

John C. Dernbach

No abstract provided.

Weryfikacja Emisji Pyłowej Z Huty Katowice I Zasięgu Jej Oddziaływania, Marian Mazur, Robert Oleniacz, Marek Bogacki, Agnieszka Łopata

Robert Oleniacz

Preliminary analysis of the results of atmospheric dispersion modeling for dust emission from the Katowice Steelworks (Poland) showed necessity of verification the particulate matter, lead and cadmium emission from the plant. The verification was limited to the substance emission sources influencing air pollution to the largest extent. Both scale of dust emission and its granulometric and chemical composition were re-evaluated. Further calculations of the air propagation for the pollutants were carried out and calculation results were compared with direct measurements. Thus the Katowice Steelworks impact on air quality and the level of total dust, lead and cadmium ground deposition was …

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 ...

On The Minimum Ropelength Of Knots And Links, Jason Cantarella, Robert B. Kusner, John M. Sullivan

Robert Kusner

The ropelength of a knot is the quotient of its length by its thickness, the radius of the largest embedded normal tube around the knot. We prove existence and regularity for ropelength minimizers in any knot or link type; these are C 1,1 curves, but need not be smoother. We improve the lower bound for the ropelength of a nontrivial knot, and establish new ropelength bounds for small knots and links, including some which are sharp.

Wpływ Związków Metali Alkalicznych W Procesie Spiekania Rud Na Emisję Pyłów, Marian Mazur, Marek Bogacki, Robert Oleniacz

Robert Oleniacz

The work shows the impact of alkali metals in the sintering process on effectiveness of the electrostatic precipitator and dust emissions into the air. The results of analysis of the content of Na and K in dust discharged from the sinter strand and emitted to the air are presented. It was found that this content is subject to large fluctuations and significantly increases in the dust phase after electrostatic precipitators. Using the balance sheet data, the effect of loads of Na2O and K2O compounds contributed to the sinter mix on emissions of dust. It was also observed high variability of …

Robust Estimation Of Origin-Destination Matrices, Byron J. Gajewski, Laurence R Rilett, Michael P. Dixon, Clifford H. Spiegelman

Byron J Gajewski

The demand for travel on a network is usually represented by an origin-destination (OD) trip table or matrix. OD trip tables are typically estimated with synthetic techniques that use observed data from the traffic system, such as link volume counts from intelligent transportation systems (ITS), as input. A potential problem with current estimation techniques is that many ITS volume counters have a relatively high error rate. The focus of this paper is on the development of estimators explicitly designed to be robust to outliers typically encountered in ITS. Equally important, standard errors are developed so that the parameter reliability can …

Polarization Jet Events And Excitation Of Weak Sar Arcs, S. Sazykin, Bela G. Fejer, Y. I. Galperin, S. A. Grigoriev, L. V. Zinin, M. Mendillo

Bela G. Fejer

[1] Polarization Jet (PJ), also known as Sub-Auroral Ion Drift (SAID), events are supersonic westward plasma drifts on the equatorward edge of the diffuse aurora in the evening and nighttime sector. Their optical F-region signatures are weak 630.0 nm red arcs colocated with regions of fast convection. These weak arcs resemble Stable Auroral Red (SAR) arcs observed during the recovery phase of magnetic storms, but have lower intensities, shorter lifetimes, and occur without a significant heat flux from the magnetosphere. Previous model studies underestimated the brightness of weak SAR arcs. We present calculations showing that ion-neutral collisional heating and ion …

Transport Out Of The Antarctic Polar Vortex From A Three-Dimensional Transport Model, Shuhua Li, Eugene Cordero, David J. Karoly

Eugene C. Cordero

[1] A three-dimensional chemical transport model is utilized to study the transport out of the Antarctic polar vortex during the southern hemisphere spring. On average, over five consecutive years between 1993 and 1997, horizontal transport out of the vortex into the midlatitude stratosphere is smaller than vertical transport into the troposphere. However, there is significant interannual variability in the magnitude of mass exchange, which is related to year-to-year fluctuations in planetary wave activity. In 1994 the net loss of the vortex tracer mass in September is similar to that in October. However, the relative mass flux entering the midlatitude stratosphere …

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.

Statistical Properties Of Composite Distortions In Hfc Systems And Their Effects On Digital Channels, Ron D. Katznelson

Ron D. Katznelson

The statistical properties of Composite Triple Beat (CTB) and Composite Second Order (CSO) distortion terms associated with the analog channels carried on Hybrid Fiber Coax (HFC) are presented. Both simulation and measurement results show that such distortion components falling on individual channels have amplitude Probability Density Function that is nearly Rayleigh distributed (having a Standard Deviation of 5.7 dB). It is shown that both CTB and CSO components have peak envelope power fluctuations that exceed their average (measured) power levels by more than 15 dB. The temporal statistical properties of these distortion components demonstrate peak envelope power fluctuations with characteristic …

Oral History Interview With Gary Durbin, Philip L. Frana

Philip L Frana

Gary Durbin is a software pioneer and entrepreneur with over thirty-five years of experience. He began his career specializing in operating systems and database systems. His first company, started in 1970, developed operating system improvements for IBM machines. That company introduced Secure, an early software security product. Secure was sold to Boole & Babbage in 1978. Durbin then founded Tesseract Corporation, a human resources software company that introduced the Time Relational Database. Tesseract was sold to ...

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 ...

Impervious Surfaces And Water Quality: A Review Of Current Literature And Its Implications For Watershed Planning, Elizabeth Brabec

Elizabeth Brabec

Impervious surfaces have for many years been recognized as an indicator of the intensity of the urban environment and, with the advent of urban sprawl, they have become a key issue in habitat health. Although a considerable amount of research has been done to define impervious thresholds for water quality degradation, there are a number of flaws in the assumptions and methodologies used. Given refinement of the methodology, accurate and usable parameters for preventative watershed planning can be developed, which include impervious surface thresholds and a balance between pervious and impervious surfaces within a watershed.

On The Existence Of Multiple Positive Solutions For A Semilinear Problem In Exterior Domains, Yinbin Deng, Yi Li

Yi Li

In this paper, we study the existence and nonexistence of multiple positive solutions for problem where Ω=^N\ω is an exterior domain in ^N, ω⊂^N is a bounded domain with smooth boundary, and N>2. μ⩾0, p>1 are some given constants. K(x) satisfies: K(x)∈C^α_loc(Ω) and ∃C, ϵ, M>0 such that |K(x)|⩽C |x|^l for any |x|⩾M, with l⩽ −2−ϵ. Some existence and …

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

Transport Properties Of Polycrystalline Type-I Sn Clathrates, G. S. Nolas, J. L. Cohn, Jeffrey Dyck, C. Uher, J. Lang

Jeffrey Dyck

Thermal conductivity, resistivity, Seebeck coefficient, and Hall measurements on polycrystalline Sn-clathrate compounds with the type-I hydrate crystal structure are reported. Interstitial alkali-metal atoms in these compounds reside inside polyhedral cavities formed by the tetrahedrally bonded Sn network atoms. Localized disorder associated with “rattling” motion of these interstitial atoms contributes to the low thermal conductivity of these semiconducting compounds. The Hall coefficient and resistivity for some compounds exhibit nonmonotonic temperature dependences consistent with a crossover with decreasing temperature from conduction-band to impurity-band conduction. The carrier mobility is found to be low even in the absence of interstitial atoms within the Sn …

Absolute Tin(111) Step Energies From Analysis Of Anisotropic Island Shape Fluctuations, S. Kodambaka, V. Petrova, S. V. Khare, Duane D. Johnson, I. Petrov, J. E. Greene

Duane D. Johnson

In situ high-temperature (1165–1248 K) scanning tunneling microscopy was used to measure fluctuations around the equilibrium shape of two-dimensional vacancy islands on TiN(111) terraces. From the equilibrium shape, the ratio of the two ⟨110⟩ step energies was found to be 0.72±0.02. Combining this with the results of an exact approach for analysis of shape fluctuations, applicable to highly anisotropic islands, we obtain absolute values for step energies and step stiffnesses as a function of orientation.

Karst Gis Advances In Kentucky, Lee J. Florea, Randall L. Paylor, Larry Simpson, Jason Gulley

Lee J Florea, PhD, P.G.

Little statewide geospatial data was available for Kentucky caves and karst in the past. Recent trends in land development have prompted a distinct need for these data in order to help minimize impact to cave and karst resources. During the past two years, the I-66 Special Project of the National Speleological Society, The Kentucky Speleological Survey, and the Kentucky Geological Survey have gathered, archived, and developed karst data for the state. Current projects include publication of karst basin maps, archiving cave entrance locations, archiving and georeferencing cave maps, creating polygon coverages of cave conduits, and a statewide sinkhole digitization project. …

Modeling Vegetative Filter Performance With Vfsmod, Matthew J. Helmers, Dean E. Eisenhauer, Michael G. Dosskey, Thomas G. Franti

Matthew J. Helmers

The model VFSMOD was used to investigate the effect of varying watershed characteristics and buffer dimensions on the sediment trapping efficiency of vegetative filters. This investigation allows for a better understanding of how watershed characteristics, buffer dimensions, and storm characteristics impact the performance of vegetative filters. Using VFSMOD, relationships that estimate sediment trapping efficiency from the ratio of filter area and field area were developed for different sites. These relationships have been applied for field assessment of concentrated flow.