bluuebunny/crossref_metadata_2025 huggingface dataset:
Feline pansteatitis revisited: Hazards of unbalanced home-made diets
Authors: Niza M.M.R.E , Vilela C.L , Ferreira L.M.A
Published: September 2003

Pansteatitis is caused by the consumption of high levels of unsaturated fatty acids and/or the insufficient intake of vitamin E, leading to inflammation of adipose tissue. This disease has been related to fish-based diets. However, non-conventional diets must also be considered. The authors present case records of two cats with pansteatitis, for which diet consisted mostly of pig's brain, comparing them with eight cases of disease in cats eating mainly oily fish.

Cats fed pig's brain did not show clinical signs, while cats eating oily fish presented inappetence, depression, reluctance to move and subcutaneous nodules painful on palpation. Cats eating pig's brain did not show any change in blood parameters, while cats fed oily fish presented leukocytosis and anaemia. Histological examination confirmed pansteatitis in all cats, independently of the diet.

All animals except one of the cats eating oily fish recovered after medical treatment and change of the feeding regime.
n‐2‐Hydroxyglutaric aciduria with absence of corpus callosum and neonatal intracranial haemorrhage
Authors: Wang X. , Jakobs C. , Bawle D. V.
Published: September 2003

Summary: We report D‐2‐hydroxyglutaric aciduria in a neonate with intracranial haemorrhage and absence of the corpus callosum. D‐2‐hydroxyglutaric acid was confirmed by specific chiral derivatization gas chromatography–mass spectrometry. Absence of the corpus callosum and spontaneous neonatal intracranial haemorrhage should raise the suspicion for metabolic disease, and especially organic acidurias.
Abnormal lysosomal inclusions in liver hepatocytes but not in fibroblasts in congenital disorders of glycosylation (CDG)
Authors: Grünewald S. , De Vos R. , Jaeken J.
Published: September 2003

Summary: We report a retrospective electron‐microscopical study of liver biopsies and fibroblast cultures of 19 patients with congenital disorders of glycosylation (CDG) of different subtypes. A constant finding in liver biopsies of all CDG‐I cases was that of abnormal lysosomal lamellar inclusions in the hepatocytes, which were not found in CDG‐II. None of the patients showed significant abnormalities in their fibroblasts.
Analysis of surface compositions in the Oxia Palus region on Mars from Mars Global Surveyor Thermal Emission Spectrometer Observations
Authors: Wyatt Michael B. , McSween Harry Y. , Moersch Jeffrey E. , Christensen Phillip R.
Published: September 2003

We examine the distribution of Thermal Emission Spectrometer (TES) derived surface compositions in the Oxia Palus region on Mars through high‐spatial‐resolution mapping and integration with Mars Orbiter Camera and Mars Orbiter Laser Altimeter data sets. We also fit the basalt and andesite‐weathered basalt interpretations of TES surface type 1 and type 2 materials into multiple working hypotheses to describe the origin of surface compositions. A mixing/transition from surface type 1 to type 2 is observed in low‐albedo regions of southern Acidalia Planitia and may represent either (1) an influx of basaltic sediment from the southern highlands, deposited on and mixed with andesitic volcanics; (2) an influx of water‐transported basaltic sediment from the southern highlands that was altered and later deposited as a thin sedimentary veneer; or (3) different degrees of weathering of indigenous basalt, marking the geographic extent of submarine alteration of basaltic crust. TES spectra of low‐albedo intracrater materials reveal that surface type 1 compositions form a central core on crater floors, while type 2 compositions form a surrounding arc on the dark downwind sides of crater walls. Intracrater floor materials are interpreted as eolian sediment, and wall materials are interpreted as either eolian sediment or eroded material from in‐place crater wall lithologies. Surface type 1 and type 2 compositions are also observed in adjacent low‐albedo wind streaks; however, a mixing trend is not as evident. The Mars Pathfinder landing site and Ares and Tiu Valles source regions are sufficiently blanketed by fine‐grained dust to prohibit the analysis of surface rock compositions.
Evaluation of new therapies for inflammatory bowel disease
Authors: Carty E. , Rampton D. S.
Published: September 2003

The pathophysiology of inflammatory bowel disease (IBD) is gradually being unravelled and new therapies are being developed to target the disturbed biological processes. This article outlines the clinical features of IBD, its current therapy and pathogenesis. The difficulties for clinical pharmacologists and gastroenterologists associated with designing, executing and interpreting clinical trials in IBD are then discussed. The final section reviews methods that can used to demonstrate the pharmacological actions of new treatments in patients with IBD. It is emphasized that proof of the therapeutic efficacy of a novel agent with a specific mechanism of action yields not only clinical benefit to patients with IBD, but also indicates the importance of the targeted biochemical pathway in the pathogenesis of the disease.
The averaging of gravity currents in porous media
Authors: Anderson Daniel M. , McLaughlin Richard M. , Miller Cass T.
Published: September 2003

We explore the problem of a moving free surface in a water-saturated porous medium that has either a homogeneous or a periodically heterogeneous permeability field. We identify scaling relations and derive similarity solutions for the homogeneous, constant coefficient case in both a Cartesian and an axisymmetric, radial coordinate system. We utilize these similarity scalings to identify half-height slumping time scales as a rough guide for field groundwater cleanup strategies involving injected brines. We derive averaged solutions using homogenization for a vertically periodic, a horizontally periodic, and a two-dimensional periodic case—the solution of which requires solving a cell problem. Using effective coefficients, we connect the first two of these homogenized solutions to the similarity scaling solution derived for the homogeneous case. By simplifying to a thin limit, retaining variations of the porous media in the horizontal direction, we derive a homogenization solution in agreement with the general horizontally layered solution and an expression for the leading-order correction. Finally, we implement two numerical solution approaches and show that self-similar scaling and agreement with leading-order averaging emerge in finite time, and demonstrate the accuracy and convergence rate of the leading order correction for both the interior and the boundary of the domain.
Intense ultraviolet cathodoluminescence at 318 nm from Gd3+-doped AlN
Authors: Vetter Ulrich , Zenneck Jan , Hofsäss Hans
Published: September 2003

We present investigations of Gd-implanted aluminum nitride, studied with cathodoluminescence (CL) as well as time-resolved CL in the temperature range 12–300 K. Luminescence due to intra-4f electron transitions of Gd3+ is dominated by the P7/26→S7/28 transition between the first excited state and the ground state of Gd3+ detected at around 318 nm. Time-resolved CL of the P7/26 level monitoring the P7/26→S7/28 transition shows a temperature-dependent lifetime which decreases from 0.76 ms at 12 K to 0.69 ms at 300 K, in contrast to an increasing intensity of the P7/26→S7/28 transition by a factor of more than 3.5 in the same temperature range. The decay is of the Inokuti–Hirayama-type indicating energy transfer between Gd3+ ions. Due to the overall weak splitting of the P7/26 and S7/28 multiplets phonon replica with energies of 100 and 588 cm−1 can be assigned.
Two statistical models for predicting collision rates of inertial particles in homogeneous isotropic turbulence
Authors: Zaichik Leonid I. , Simonin Olivier , Alipchenkov Vladimir M.
Published: September 2003

The objective of the paper is to present and compare two models for the collision rate of inertial particles immersed in homogeneous isotropic turbulence. The merits and demerits of several known collision models are discussed. One of the models proposed in the paper is based on the assumption that the velocities of the fluid and a particle obey a correlated Gaussian distribution. The other model stems from a kinetic equation for the probability density function of the relative velocity distribution of two particles. The predictions obtained by means of these two models are compared with numerical simulations published in the literature.
Study of ammonia-gas-induced irreversibility in polypyrrole films
Authors: Choi Jaewu , Hormes J. , Kahol Pawan K.
Published: September 2003

Polypyrrole’s conductivity as a function of polymerization temperature and its properties on treatment with ammonia gas are studied. Electronic structures of PF6 (hexafluorophosphate) doped polypyrrole (PPY) films grown at −40, 0, and 20 °C, before and after ammonia treatment, are compared using angle resolved photoemission spectroscopy, electron paramagnetic spectroscopy, and semiempirical calculations. The valence band electronic structures of these polypyrrole films largely depend on polymerization temperature, and ammonia treatment. The light-polarization-dependent valence band structures reflect ordering of polymer chains with decreasing polymerization temperature. The irreversibility properties of polypyrrole, which can be used as an ammonia gas senor, are shown to possibly arise from detachment of the dopant molecules under pumping.
Ultrafast nonresonant third-order optical nonlinearity of fullerene-containing polyurethane films at telecommunication wavelengths
Authors: Chen Qiying , Kuang Li , Sargent Edward H. , Wang Zhi Yuan
Published: September 2003

High-optical-quality polyurethane films containing a high load of (60)fullerene (C60) were prepared by reaction of the hydroxy-containing C60 and triisocyanate with the goal of obtaining enhanced nonresonant third-order optical nonlinearity. Optical nonlinearity was measured using the Z-scan technique in the wavelength range 1150–1600 nm. This revealed a positive Kerr coefficient with nonresonant n2 equal to 2.0(±0.6)×10−3 cm2/GW and excellent linear-absorption and nonlinear-absorption figures of merit at 1550 nm. The technique reported herein is a new approach to obtain fullerene films with the capacity to realize a high number density of C60 moieties. These resulted in more than 2 orders of enhancement in the third-order susceptibility over recently reported C60 sol and gel, and an enlarged second-order hyperpolarizability resulting from further enhanced charge transfer processes.
Observation of ferroelectromagnetic nature in rare-earth-substituted bismuth iron titanate
Authors: Srinivas A. , Kim Dong-Wan , Hong Kug Sun , Suryanarayana S. V.
Published: September 2003

Rare earth ions; Nd, Sm, Gd, and Dy, are substituted at the bismuth site in bismuth iron titanate, a four-layered compound which belongs to bismuth layer structured ferroelectrics. A solid-state sintering route was adopted in synthesizing the materials. X-ray diffraction indicates the formation of single-phase materials. The dielectric measurements showed the anomalies at high temperatures. Dynamic magnetoelectric measurements showed magnetoelectric output at room temperature and at low temperatures. Thus, the material is ferroelectromagnetic in nature.
Microwave distribution in stacked Bi2Sr2CaCu2O8+x intrinsic Josephson junctions in a transmission-line geometry
Authors: Bae Myung-Ho , Lee Hu-Jong , Kim Jinhee , Kim Kyu-Tae
Published: September 2003

The microwave distribution inside a rectangular stack (15 μm×0.72 μm×60 nm) of Bi2Sr2CaCu2O8+x intrinsic Josephson junctions (IJJs) was studied. The stack was microfabricated into a transmission-line geometry, with a-few-hundred-nm-thick Au layers deposited on the top and bottom of the stack. The microwave distribution was monitored by measuring the anomalous suppression of the tunneling critical current of the IJJs with varied microwave power at frequencies in the W band. This technique can provide valuable information on the microwave transmission modes inside the sandwiched stack of IJJs, which is utterly important for the high-frequency device applications using IJJs, such as fluxon-flow THz oscillators.
Experimental evidence of carrier leakage in InGaAsN quantum-well lasers
Authors: Tansu Nelson , Yeh Jeng-Ya , Mawst Luke J.
Published: September 2003

Carrier leakage processes are shown experimentally as one of the factors contributing to the temperature sensitivity of InGaAsN quantum well lasers. The utilization of the direct barriers of GaAs0.85P0.15 instead of GaAs, surrounding the InGaAsN quantum-well (QW)-active region, leads to significant suppression of carrier leakage at elevated temperatures of 90–100 °C. Threshold current densities of only 390 and 440 A/cm2 was achieved for InGaAsN QW lasers (Lcav=2000 μm) with GaAs0.85P0.15-direct barriers at temperature of 80 and 90 °C, respectively.
Percolation path and dielectric-breakdown-induced-epitaxy evolution during ultrathin gate dielectric breakdown transient
Authors: Tung Chih Hang , Pey Kin Leong , Tang Lei Jun , Radhakrishnan M. K. , Lin Wen He , Palumbo Felix , Lombardo Salvatore
Published: September 2003

A physical model has been developed which complies with the experimental observation on the failure mechanism of ultrathin gate oxide breakdown during constant voltage stress. Dynamic equilibrium needs to be established between the percolation conductive path and the dielectric breakdown induced epitaxy (DBIE) formation during gate dielectric breakdown transient. The model is capable of linking the percolation model, soft breakdown, and hard breakdown to the DBIE growth for a variety of stress conditions and gate oxide thickness without involving new empirical parameters.
Nanosolution as a New Turn of Nanoconfinement for Fluids
Authors: Ohkubo Takahiro , Kanoh Hirofumi , Kaneko Katsumi
Published: September 2003

Towards the goal of nanoscale molecular systems, little work has been undertaken on ionic solutions at the nanoscale (‘nanosolution’, NSN). Functional nanoporous materials can be applied to confine, and thereby allow study of molecular assemblies and NSNs; electrically neutral hydrophobic pores reveal a particularly marked confinement effect. This article summarizes the properties and structures of molecules confined within nanospaces and the pioneering work on the distorted and partially dehydrated structures of NSNs.
Thin Films of a Tetracationic Porphyrin
Authors: O'Driscoll Benjamin M. D. , Ruggles Jeremy L. , Foran Garry J. , Gentle Ian R.
Published: September 2003

Langmuir–Blodgett films of the tetracationic porphyrin tetrakis(octadecyl-4-pyridinium)porphinatozinc(II) bromide transferred from subphases containing different salts were studied using X-ray photoelectron spectroscopy (XPS) and X-ray reflectometry. In contrast to previous results at the air/water interface, we found that the porphyrin adopted a fixed conformation at the air/solid interface regardless of composition of the subphase or whether the films were transferred above or below the primary phase transition. This conformation was assigned to the formation of an interdigitated bilayer structure.
Meditation on an Engraving of Fricke and Klein (The Modular Group and Geometrical Chemistry)
Authors: Hyde Stephen T. , Larsson Ann-Kristin , Di Matteo Tiziana , Ramsden Stuart , Robins Vanessa
Published: September 2003

A non-technical account of the links between two-dimensional (2D) hyperbolic and three-dimensional (3D) euclidean symmetric patterns is presented, with a number of examples from both spaces. A simple working hypothesis is used throughout the survey: simple, highly symmetric patterns traced in hyperbolic space lead to chemically relevant structures in euclidean space. The prime examples in the former space are derived from Felix Klein's engraving of the modular group structure within the hyperbolic plane; these include various tilings, networks and trees. Disc packings are also derived. The euclidean examples are relevant to condensed atomic and molecular materials in solid-state chemistry and soft-matter structural science. They include extended nets of relevance to covalent frameworks, simple (lattice) sphere packings, and interpenetrating extended frameworks (related to novel coordination polymers). Limited discussion of the projection process from 2D hyperbolic to 3D euclidean space via mapping onto triply periodic minimal surfaces is presented.
Sea anemone host selection by the symbiotic saddled cleaner shrimp Periclimenes holthuisi
Authors: Khan Ritindra N. , Becker Justine H. A. , Crowther Andrea L. , Lawn Ian D.
Published: September 2003

A preliminary field survey was conducted to determine the distribution of ectosymbiotic shrimp Periclimenes holthuisi on the sea anemone Stichodactyla haddoni in Moreton Bay (Queensland, Australia). Laboratory experiments were also carried out to verify whether the shrimp show a preference for one anemone host. In the field, 45 individuals of P. holthuisi were found to be associated with 70% of the specimens of S. haddoni (n�=�20). We inferred this shrimp population was not space-limited because not all anemones were colonized. After having been isolated from their natural host for 2 weeks, when placed between individuals of S. haddoni and Macrodactyla doreensis (an anemone that is sympatric with S. haddoni), shrimp overwhelmingly selected S.�haddoni (92%). To establish whether M. doreensis may serve as an alternative host for P. holthuisi, unacclimated shrimp were forced to associate with this anemone. Macrodactyla doreensis showed little tentacle reaction during this association; shrimp were found on the anemone's tentacles and the column. The finding that M. doreensis can serve as an alternative host for P. holthuisi demonstrates that this anemoneshrimp is adaptable to another anemone host and thus may not be highly host specific.
Field study of pesticide leaching in an allophanic soil in New Zealand. 2: Comparison of simulations from four leaching models
Authors: Close M. E. , Pang L. , Magesan G. N. , Lee R. , Green S. R.
Published: September 2003

Seven pesticides were applied to an allophanic silt loam along with a bromide tracer and their concentrations in soil and water monitored over a 2-year period. Inverse modelling was carried out using GLEAMS, LEACHM, and HYDRUS-2D to derive field-based mobility and degradation parameters. Hexazinone and procymidone were more mobile and more persistent than most literature values would suggest, whereas picloram and triclopyr were much less mobile but more persistent. The greater mobility for hexazinone, a weak base, and the reduced mobility of picloram and triclopyr, weak acids, are consistent with the effects of allophane. Mobility values for 2,4-D, atrazine, and terbuthylazine could not be determined with confidence from experimental results, but both atrazine and terbuthylazine appeared less persistent, and 2,4-D more persistent than literature values. A fourth model, SPASMO, currently under development, was used as an independent test of the optimised parameters. It performed well for the soil water concentrations but tended to overestimate the observed soil concentrations using the derived parameters. HYDRUS-2D simulations of bromide and hexazinone concentrations in the groundwater gave a good fit to observed data from 3 monitoring wells following a large recharge pulse.
Transformation and fixation of Zn in two polluted soils by changes of pH and organic ligands
Authors: Collins Richard N. , Merrington Graham , McLaughlin Mike J. , Morel Jean-Louis
Published: September 2003

Although the movement of Zn from the solid to the solution phase of soils is a significant process preceding plant uptake, the quantity of metal that can be solubilised through rhizosphere processes is also extremely important. Therefore, the consequences of plant-derived organic ligands, and changes in pH on the isotopically exchangeable quantity of Zn (E value) were examined in a polluted acid and calcareous soil. Variations in pH were facilitated through the use of dilute NaOH or HNO3 solutions. The organic ligands studied included 0.25–5 mM concentrations of sodium tartrate, the free acid and sodium salt of citrate, histidine, and deoxymugineic acid. As expected, the organic ligands and a reduction in pH increased the solution concentration of Zn in these soils. Furthermore, through the application of isotopic dilution techniques, it was determined that some of these organic ligands could significantly increase the quantity of isotopically exchangeable Zn. However, with the exception of the 5 mM sodium citrate treatment in the calcareous soil, pH was the overriding parameter that effected changes in the E value. Reducing the pH by approximately 2 units increased the E value by 39 and 80%, respectively, in the acid and calcareous soil. Conversely, evidence for Zn fixation (a decrease of the E value) was observed in the acid soil when pH was increased. The exudation of organic ligands and variations of pH induced by plants have the potential to significantly vary the quantity of phytoavailable Zn in these 2 polluted soils.
Comparing fluid mechanics models with experimental data
Authors: Spedding G. R.
Published: September 2003

The art of modelling the physical world lies in the appropriate simplification and abstraction of the complete problem. In fluid mechanics, the Navier–Stokes equations provide a model that is valid under most circumstances germane to animal locomotion, but the complexity of solutions provides strong incentive for the development of further, more simplified practical models. When the flow organizes itself so that all shearing motions are collected into localized patches, then various mathematical vortex models have been very successful in predicting and furthering the physical understanding of many flows, particularly in aerodynamics. Experimental models have the significant added convenience that the fluid mechanics can be generated by a real fluid, not a model, provided the appropriate dimensionless groups have similar values. Then, analogous problems can be encountered in making intelligible but independent descriptions of the experimental results. Finally, model predictions and experimental results may be compared if, and only if, numerical estimates of the likely variations in the tested quantities are provided. Examples from recent experimental measurements of wakes behind a fixed wing and behind a bird in free flight are used to illustrate these principles.
Photosynthesis and Growth of Tobacco with a Substituted Bacterial Rubisco Mirror the Properties of the Introduced Enzyme
Authors: Whitney Spencer M. , Andrews T. John
Published: September 2003

Complete replacement, by biolistic plastid transformation, of the hexadecameric ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) of tobacco (Nicotiana tabacum) with the dimeric version from the bacterium, Rhodospirillum rubrum, resulted in fully autotrophic and reproductive tobacco plants that required high CO2 concentrations to grow (Whitney SM, Andrews TJ [2001] Proc Natl Acad Sci USA 98: 14738-14743). Growth and photosynthesis of these plants was compared with that of nontransformed tobacco and other controls where the rbcL gene for the large subunit of tobacco Rubisco was linked to the aadA selectable-marker gene, simulating the gene arrangement of the transformants with R. rubrum Rubisco. An arrangement of the rbcL and aadA genes that gave rise to an abundant monocistronic rbcL transcript and a one-fifth as abundant bicistronic rbcL-aadA transcript had Rubisco levels and photosynthetic properties similar to those of nontransformed tobacco. Direct linkage of the rbcL and aadA genes, resulting in exclusive production of a bicistronic mRNA transcript analogous to that of the transformants with R. rubrum Rubisco, reduced transcript abundance and tobacco Rubisco content. The analogous transcript with the R. rubrum rbcM gene substituted for rbcL was not only reduced in abundance, but was also translated less efficiently. The photosynthetic rates of the transformants and controls were measured at high CO2 concentrations, using a mass spectrometric method. The rates and their responses to atmospheric CO2 concentration mirrored the amounts and the kinetic properties of the Rubiscos present. The contents of total nitrogen, carbohydrates, and photosynthetic metabolites of the leaves were also consistent with the content and type of Rubisco.
Preschoolers' Use of Form Class Cues to Learn Descriptive Proper Names
Authors: Geoffrey Hall D. , Waxman Sandra R. , Brédart Serge , Nicolay Anne‐Catherine
Published: September 2003

This study examined 3‐ and 4‐year‐old preschoolers' ability to learn proper names containing familiar descriptions. Children saw a novel creature with a familiar property (it was red) and heard either an adjective (“This is a red one”) or a descriptive proper name (“This is Mr. Red”). The creature was then transformed, losing the property (e.g., it became green). Children had to extend the word to either the transformed original creature or a new creature bearing the original property (another red creature). Children, especially 4‐year‐olds, extended the adjective to the new creature but were significantly more likely to extend the proper name to the original creature. Lexical form class cues provided potent information about word meaning, directing preschoolers to reinterpret familiar descriptive terms (adjectives) as homophonic terms designating unique individuals (proper names).
Accident Epidemiology and the U.S. Chemical Industry: Accident History and Worst‐Case Data from RMP*Info
Authors: Kleindorfer Paul R. , Belke James C. , Elliott Michael R. , Lee Kiwan , Lowe Robert A. , Feldman Harold I.
Published: September 2003

This article reports on the data collected on one of the most ambitious government‐sponsored environmental data acquisition projects of all time, the Risk Management Plan (RMP) data collected under section 112(r) of the Clean Air Act Amendments of 1990. This RMP Rule 112(r) was triggered by the Bhopal accident in 1984 and led to the requirement that each qualifying facility develop and file with the U.S. Environmental Protection Agency a Risk Management Plan (RMP) as well as accident history data for the five‐year period preceding the filing of the RMP. These data were collected in 1999–2001 on more than 15,000 facilities in the United States that store or use listed toxic or flammable chemicals believed to be a hazard to the environment or to human health of facility employees or off‐site residents of host communities. The resulting database, RMP*Info, has become a key resource for regulators and researchers concerned with the frequency and severity of accidents, and the underlying facility‐specific factors that are statistically associated with accident and injury rates. This article analyzes which facilities actually filed under the Rule and presents results on accident frequencies and severities available from the RMP*Info database. This article also presents summaries of related results from RMP*Info on Offsite Consequence Analysis (OCA), an analytical estimate of the potential consequences of hypothetical worst‐case and alternative accidental releases on the public and environment around the facility. The OCA data have become a key input in the evaluation of site security assessment and mitigation policies for both government planners as well as facility managers and their insurers. Following the survey of the RMP*Info data, we discuss the rich set of policy decisions that may be informed by research based on these data.
Presidential Greatness as an Attribute of Warmaking
Authors: Adler David Gray
Published: September 2003

The founders of the nation were acutely aware of the penchant among executives to pursue war as a means of achieving fame and glory. Scholars, like presidents, have assumed a strong correlation between presidential tenure during war and presidential greatness. That assumption must necessarily rest on either the decision to go to war or on the president's conduct of war, or on both considerations. This essay contends that, contrary to the assumption of a linkage between wartime service and presidential greatness, very few presidents have achieved greatness through war, and that for others, the path of war has been a path to disappointment and devastation.
Organizing for Homeland Security
Authors: Relyea Harold C.
Published: September 2003

For much of the twentieth century, Congress and the president were rivals for determining the organization of the executive branch. The events of September 11, 2001 did not end that contest. The president sought to be the architect of new arrangements for protecting and maintaining homeland security, a nebulous term seeking to be a policy concept. Initial institutions created to exert leadership and coordination on behalf of the president were the Office of Homeland Security and the Homeland Security Council, simultaneously established by an executive order. Several months later, the president called for a new administrative organization, and steadfastly pursued the mandating of a Department of Homeland Security, composed of existing entities of his choosing and vested with managerial flexibilities he considered to be essential. Ultimately, he largely obtained what he wanted in the legislation mandating the department.
The Contemporary Presidency: Rating the Presidents: A Tracking Study
Authors: Lonnstrom Douglas A. , Kelly, II Thomas O.
Published: September 2003

This article, based on four presidential tracking studies by academics conducted over a 20‐year period, seeks, through analysis of those studies, to answer five questions:

1. Is there any correlation between views held about a president early in his term/s or immediately after his term ends, and those held much later?

2. Is there a pattern to such rankings as they change over time?

3. Can we explain why change occurs?

4. Can actions taken by a president after he has left office significantly alter his ranking?

5. When might the process of change be, to all intents and purposes, complete? Is there, for example, a 25‐year rule? 50?
Real-time etching monitor using argon quadrupole mass spectrometry for 100 nm class WSiN gate fabrication
Authors: Jin Y. , Takahashi C. , Ono T.
Published: September 2003

We have developed a real-time etching monitor technique for 100 nm class WSiN gate fabrication that uses mass analysis of argon. The WSiN film absorbs argon atoms during the sputter-deposition process, and argon atoms are emitted back into the etching chamber when the WSiN film is etched in a SF6–CF4–SiF4–O2 gas mixture. By using a quadrupole mass spectrometer (QMS) to detect the emitted argon atoms, we can determine an accurate just etching time and estimate the most appropriate overetching time. This monitoring technique has sufficient signal intensity, follows etching within 1 s, has no effect on the etching reaction products, and has a small deviation in signal intensity between wafers. Using the monitor, we obtained a vertical and anisotropic etched pattern with a small GaAs loss. We compared the predictions of the QMS monitor with those of optical emission spectrometry. We demonstrated that the technique is well suited for multilayer-gate WSiN etching by using it to detect the nitrogen concentration in WSiN film.
Preparation and characterization of superhard boron-suboxide films
Authors: Huang H. , Ong C. W. , Zheng B. , Kwok R. W. M. , Lau W. M. , He J. W.
Published: September 2003

Boron-suboxide films with hardness reaching 44 GPa, the highest record ever achieved, were synthesized. The films with such high hardness had an oxygen/boron atomic concentration ratio of 0.05 and a carbon concentration of about 20 at. %. They were deposited on silicon at 750 °C by simple sputtering. In the range of oxygen/boron ratio varying from 0.06 to 0.3, the film hardness and elastic modulus decreased monotonically. Unlike other hard film formation, argon ion bombardment of the film during film growth reduced the film hardness.
Mass spectral resolution of F+ and H3O+ in very high vacuum
Authors: Cole C. R. , Outlaw R. A. , Champion R. L. , Baker D. H. , Holloway B. C.
Published: September 2003

This brief report presents mass spectral resolution of H3O+ and F+ at mass 19 in a high vacuum system. Typically, this mass spectral peak observed in residual gas analyzers has always been attributed to fluorine. Using Fourier transform mass spectrometry, the presence of the hydronium ion was fully resolved from fluorine and it is shown that there is ample time for the formation of the hydronium ion through ion–molecule interactions.
Focusing of MeV ion beams by means of tapered glass capillary optics
Authors: Nebiki T. , Yamamoto T. , Narusawa T. , Breese M. B. H. , Teo E. J. , Watt F.
Published: September 2003

We present evidence of the focusing effects of fine glass capillary optics for MeV He ion beams. The glass capillary optics are formed by a puller as to have inlet diameters of about 1 mm and outlet diameters of submicrons. The total length of the optics is about 50 mm. Impingent MeV ions to such optics are reflected by the inner wall several times, in a very similar process to the so-called surface channeling. The majority of incident ions are lost by the dechanneling, or large-angle scattering process, however, a part of them, actually about 1% more or less, is emitted through the outlet without significant energy loss. Compared with the conventional micro-ion beam facilities, the present method is certainly simple and lowcost, thus providing an easy method of submicron Rutherford backscattering spectrometry or particle induced x-ray emission analyses. In addition, if the ion species are extended to heavier elements, the present method provides versatile maskless ion implantation techniques.
Plasma load characteristics of pulsed-bias arc ion plating
Authors: Lin Guoqiang , Ding Zhenfeng , Qi Dong , Zhao Yanhui , Wang Ninghui , Dong Chuang , Huang Rongfang , Wen Lishi
Published: September 2003

In a pulsed-bias arc ion plating system, the load voltage and current in the substrate circuit manifest oscillation behaviors. A simple analogous electrical circuit model is then constructed, which consists of a pair of capacitor and resistor connected in parallel. The output of the analogous circuit reproduces the oscillation profiles measured from experiments. Finally, plasma sheath theory is used to explain the capacitance characteristic of the plasma load.
Observation of the phase formation in Fe–N films deposited by reactive pulsed laser deposition
Authors: Wang N. , Ulmer K. M. , Constant A. P. , Anderegg J. W. , Snyder J. E.
Published: September 2003

Fe–N films have been grown on SiO2/Si(100) substrates by reactive pulsed laser deposition (PLD). A series of films was deposited at 20 °C and at 250 °C, with a wide range of nitrogen pressures. Both nitrogen pressure and deposition temperature were found to affect the film average compositions, structures, phase percentages, and magnetic properties of the films. The saturation magnetization of the films is shown to depend not only on their average nitrogen content but also on the phases and their relative amounts that make up the films. In particular, the iron nitrides γ′-Fe4N, and ε-Fe3N (which has a wide range of composition) play a major role in determining the magnetization. Results can be understood in terms of the relative contributions of the deposition rate and atomic surface diffusion in producing thin-film structure. To date, no giant moments larger than Ms of pure Fe have been observed in this investigation.
Surface theory moves into the real world
Authors: Feibelman Peter J.
Published: September 2003

Scanning-probe and low-energy electron microscopy offer detailed views of surface morphology and its time-evolution. Experimental tools developed earlier, like low-energy electron diffraction, provide quantitative surface structural parameters. The unrelenting advance of computer power and key improvements in algorithmic efficiency make it possible to derive full value from these potent surface characterization tools by providing reliable, often predictive interpretation. Bridging length- and time scales are the key surface theory projects in a research environment dominated by nanotechnology.
Electronic materials growth: A retrospective and look forward
Authors: Tu Charles W.
Published: September 2003

This article reviews the development of electronic materials, primarily III–V compound semiconductors, from substrates to epitaxy and in situ monitoring to heterostructures, quantum wells and superlattices, that are important to various device applications. As the current research direction leads to the immediate future, the article then summarizes some of the recent advancement in quantum wires, nanowires, and quantum dots.
American Vacuum Society leadership in electronic materials processing: Past, present, and future
Authors: Lucovsky Gerald , Rubloff Gary
Published: September 2003

This article traces the evolution of electronics materials processing in the American Vacuum Society (AVS) up to the present time, and projects the trajectory of this activity into the future. The format and style of this article benefits from perspective of one of the authors (G.L.), who has been editor-in-chief of the Journal of Vacuum Science and Technology (JVST) for more than 20 years, and who has additionally contributed personally to materials processing research through interactions involving AVS symposia, divisions, and publications in the JVST. Major areas of contributions are identified, and then are correlated with the evolution of the AVS and JVST. As we move into the 21st century, the foundation laid by a strong presence in electronic materials processing is proving to be the basis for emerging cross-disciplinary AVS activities in the nanoscience and technology advances that will continue to evolve in unanticipated ways in 21st century and beyond.
Plasma-based physical vapor deposition surface engineering processes
Authors: Matthews Allan
Published: September 2003

Plasma-based physical vapor deposition (PVD) process developments occurring over the past few decades now allow the production of tribological coatings with properties which were previously unachievable. These new coatings will be critical in the creation of new products with improved functionality and performance, which will have a dramatic impact on, for example, their operating efficiency and lifetime. The key pioneers behind these PVD developments are discussed here, together with some significant process innovations. The latter include ionization-enhancing systems, such as thermionic assistance and arc evaporation, as well as unbalanced magnetron sputtering and magnetic plasma confinement. These developments have provided the impetus behind the recent growth in the technology field which we now know as surface engineering, and the recognition that surfaces provide the functionality and durability for almost all engineered products. Vacuum plasma technologies can thus be regarded as critical, not only for functional devices and thin film applications (for which their importance was previously most recognized), but also for structural product applications; they will thus underpin the entire spectrum of manufacturing industry.
Materials in nanotechnology: New structures, new properties, new complexity
Authors: Bonnell Dawn A.
Published: September 2003

The evolution of nanoscale science and technology has dramatically expanded the classes of materials being explored and even implemented in device applications. This article summarizes advancements in making low dimensional structures from inorganic and organic compounds, determining the resulting, and necessarily local properties and assembling complex structures.
Transitioning from the art to the science of thin films: 1964 to 2003
Authors: Greene J. E.
Published: September 2003

The origin of the modern era of thin film technology is closely linked to the development of vacuum technology. However, the more recent emergence of thin film science as an identifiable field of investigation parallels the development and adaptation of surface structural and chemical probes to provide in situ real-time atomic-scale data during film growth. The ready accessibility of high-resolution transmission electron microscopy also played an important role. The next step in this evolutionary process, which is occurring right now, is the addition of theory and modeling as standard approaches, used in combination with the above physical tools, to complement, design, and analyze experiments. The beautifully hierarchical complexity associated with thin film microstructural and surface morphological evolution, which arises from a diverse set of competitive kinetic instabilities operating on very different time and length scales, assures that thin film science and technology will remain a vital and exciting field long into the future. While the present focus of the field is on film growth from the vapor phase, there is an increasingly strong resurgent interest, driven by nanotechnology and the desire to extend self-organization to higher spatial orders, in film growth from solution.
Morphological instabilities in thin-film growth and etching
Authors: Cahill David G.
Published: September 2003

Experiments and theory have shown that surface morphology during thin-film growth and etching is often unstable. Pattern formation of the morphology results when a mechanism that destabilizes the morphology on long length scales competes with a mechanism that stabilizes the morphology on short length scales. We review some of the important mechanisms—e.g., asymmetric attachment kinetics at step edges, mechanical stress, curvature dependence of the sputtering yield, capillarity, viscous flow, and the nucleation and growth of new layers—and apply linear stability analysis to determine the length scales and growth rates of the instabilities.
Measurement of charge-separation potentials in GaAs1−xNx
Authors: Johnston S. W. , Ahrenkiel R. K. , Tu C. W. , Hong Y. G.
Published: September 2003

The ternary alloy GaAs1−xNx is interesting as a semiconductor that can be grown epitaxially on GaAs. As is well known, the band gap can be reduced by as much as 0.4 eV by changing the nitrogen concentration from 0% to 3%. We measured the spectral response and photoconductive lifetime of the alloys as a function of temperature. In this work, the films were grown by gas-source molecular-beam epitaxy on semi-insulating GaAs substrates. All measurements were made using the contactless, resonant-coupled photoconductive decay method. Our data show that the spectral response of GaAs1−xNx alloys consists of photoconductive band tails that extend well into the infrared (beyond the nominal band gap). For example, the photoconductive band tails extend to about 1900 nm for GaAs0.967N0.033 at room temperature. The primary photoconductive decay times are in the range of 200–300 ns at room temperature. At temperatures below about 200 K, the decay rate decreases substantially. By plotting the decay rate values on an Arrhenius plot, we calculate activation energies of 70–80 meV for GaAs1−xNx samples with x=1.1%–3.3%. These energies represent potential barriers that inhibit recombination.
A simple method for estimating the thickness of the atmosphere by light scattering
Authors: Vollmer Michael
Published: September 2003

A simple experiment on light scattering in the atmosphere is presented, which allows us to estimate the thickness of the atmosphere. The experiment is based on an idea by Wood and uses only tubes, diaphragms, and a partially reflecting mirror as optical elements.
Supercritical bifurcation of a spinning hoop
Authors: Moisy Frédéric
Published: September 2003

The motion of a hoop hung on a spinning string provides an illustrative and pedagogical example of a supercritical bifurcation. Above a certain angular velocity threshold Ωc, the hoop rises and spins about its symmetry axis. The equation of motion is derived in the limit of a long massless string, and the calculated steady states are compared to experimental measurements. This simple experiment is suitable for classroom demonstration, and provides an interesting alternative to the classical experiment of a bead sliding on a rotating hoop.
Textbook treatments of the hysteresis loop for ferromagnets—Survey of misconceptions and misinterpretations
Authors: Rudowicz C. , Sung H. W. F.
Published: September 2003

A close look at the definitions of “coercivity” reveals two distinct notions: one referring to the hysteresis loop for B vs H and the other to that of M vs H. These are confused in several books. The properties of the M vs H loop are often ascribed to the B vs H loop, giving rise to various misconceptions. In this note we highlight a number of misconceptions and misinterpretations in the textbook presentations of the hysteresis loop for ferromagnets. This brief report is aimed at helping faculty become aware of the existence of problems in the current literature.
Cooling Bose-Einstein Condensates Below 500 Picokelvin
Authors: Leanhardt A. E. , Pasquini T. A. , Saba M. , Schirotzek A. , Shin Y. , Kielpinski D. , Pritchard D. E. , Ketterle W.
Published: September 2003

Spin-polarized gaseous Bose-Einstein condensates were confined by a combination of gravitational and magnetic forces. The partially condensed atomic vapors were adiabatically decompressed by weakening the gravito-magnetic trap to a mean frequency of 1hertz, then evaporatively reduced in size to 2500 atoms. This lowered the peak condensate density to 5 × 10
10
atoms per cubic centimeter and cooled the entire cloud in all three dimensions to a kinetic temperature of 450 ± 80 picokelvin. Such spin-polarized, dilute, and ultracold gases are important for spectroscopy, metrology, and atom optics.
Geometrical and vibrational DFT studies of HOBr·(H2O)n clusters (n = 14)
Authors: Santos Cristina Maria P , Faria Roberto B , De Almeida Wagner B , Machuca-Herrera Juan O , Machado Sérgio P
Published: September 2003

The geometrical structures and the vibrational spectra of the HOBr·(H2O)n clusters (n = 14) have been calculated at the DFT level of theory, using the pBP method and the DN* and DN** numerical basis sets. The results showed that the interaction involving the H of the HOBr and the O of the water molecule represent the preferred arrangements for these hydrated compounds. Both HOBr·H2O and HOBr·(H2O)2 clusters presented stable structures with syn and anti conformations, the syn being the most stable. The HOBr·(H2O)3 and the HOBr·(H2O)4 clusters have presented stable cyclic structures. In the HOBr·H2O and HOBr·(H2O)2 clusters, low-frequency stretching values could be assigned to hydrogen bonds, but the same could not be done so clearly for the HOBr·(H2O)3 and the HOBr·(H2O)4 cyclic clusters. The binding energies were also determinated for these HOBr hydrated clusters, showing that the addition of a water molecule to the HOBr·H2O and HOBr·(H2O)2 clusters increases the binding energy by approximately 4 kcal mol1, while the addition of a water molecule to the HOBr·(H2O)3 cluster decreases this value by 4 kcal mol1.Key words: DFT, numerical basis, HOBr·(H2O)n, clusters.
Novel synthesis of a highly functionalized cyclopropane derivative
Authors: Trudeau Stéphane , Deslongchamps Pierre
Published: September 2003

A model study was carried out to explore the feasibility of synthesizing fused tricyclic ring structures containing a C7C8 double bond juncture (steroid numbering) by employing an SN2' cyclization of a silyl enol ether to displace an allylic acetate as the key step. Instead of the anticipated product, highly functionalized cyclopropanes were obtained. These novel cyclopropane structures are the result of the concomitant 1,2-migration of a dithiane thioether moiety and the eventual displacement of the acetate group, followed by the cyclization of the silyl enol ether.Key words: tricycles, SN2' cyclization, inductive effect, cyclopropane.