bluuebunny/crossref_metadata_2025 huggingface dataset:
ACTIVE INFORMATION GATHERING IN INFOSLEUTHTM
Authors: NODINE MARIAN , FOWLER JERRY , KSIEZYK TOMASZ , PERRY BRAD , TAYLOR MALCOLM , UNRUH AMY
Published: August 2002

InfoSleuth is an agent-based system that can be configured to perform many different information management activities in a distributed environment. InfoSleuthTM agents provide a number of complex query services that require resolving ontology-based queries over dynamically changing, distributed, heterogeneous resources. These include distributed query processing, location-independent single-resource updates, event and information monitoring, statistical or inferential data analysis, and trend discovery in complex event streams. It has been used in numerous applications, including the Environmental Data Exchange Network and the Competitive Intelligence System.
CLASSIFYING LOCAL QUERIES FOR GLOBAL QUERY OPTIMIZATION IN MULTIDATABASE SYSTEMS
Authors: ZHU QIANG , LARSON P.-Å.
Published: August 2002

A multidatabase system (MDBS) integrates information from multiple pre-existing local databases. A major challenge for global query optimization in an MDBS is that some required local information about local database systems such as local cost models may not be available at the global level due to local autonomy. A feasible method to tackle this challenge is to group local queries on a local database system into classes and then use the costs of sample queries from each query class to derive a cost formula for the class via regression analysis. This paper discusses the issues on how to classify local queries so that a good cost formula can be derived for each query class. Two classification approaches, i.e. bottom-up and top-down, are suggested. The relationship between these two approaches is discussed. Classification rules that can be used in the approaches are identified. Problems regarding composition and redundancy of classification rules are studied. Classification algorithms are given. To test the membership of a query in a class, an efficient algorithm based on ranks is introduced. In addition, a hybrid classification approach that combines the bottom-up and top-down ones is also suggested. Experimental results demonstrate that the suggested query classification techniques can be used to derive good local cost formulas for global query optimization in an MDBS.
Effect of modafinil on the pharmacokinetics of ethinyl estradiol and triazolam in healthy volunteers
Authors: Robertson Philmore , Hellriegel Edward T. , Arora Sanjay , Nelson Michael
Published: August 2002

Background

Modafinil has been reported to produce a concentration‐related induction of CYP3A4/5 activity in vitro in primary cultures of human hepatocytes.

Objective

Our objective was to determine whether the pharmacokinetics of steady‐state ethinyl estradiol (INN, ethinylestradiol) and single‐dose triazolam were altered after 4 weeks of modafinil treatment in volunteers.

Methods

This was a placebo‐controlled, single‐blind, single‐period study in 41 female subjects who were receiving long‐term treatment with an oral contraceptive that contained ethinyl estradiol (0.035 mg) and norgestimate (0.180–0.250 mg). Pharmacokinetic profiles for ethinyl estradiol and for a single oral dose of triazolam (0.125 mg) were obtained the day before initiation of treatment with modafinil (200 mg for 7 days, followed by 400 mg for 21 days) or placebo (28 days). A second dose of triazolam was administered with the final dose of modafinil, and pharmacokinetic profiling was repeated.

Results

The modafinil treatment group had a marked decrease in maximum observed plasma concentrations and areas under the plasma concentration–time curve for triazolam relative to placebo, with a much smaller decrease in these parameters for ethinyl estradiol. The half‐life of triazolam was also decreased, but the half‐life of ethinyl estradiol did not appear to be affected by treatment with modafinil.

Conclusion

Modafinil induced CYP3A4/5 activity in humans in vivo, suggesting that there is potential for metabolic drug‐drug interactions between modafinil and substrates of CYP3A4/5. However, the induction appeared to be more gastrointestinal than hepatic in nature. Therefore significant metabolic drug‐drug interactions are most likely to occur with compounds (such as triazolam) that undergo significant gastrointestinal CYP3A4/5‐mediated first‐pass metabolism.

Clinical Pharmacology & Therapeutics (2002) 71, 46–56; doi: 10.1067/mcp.2002.121217
Pharmacokinetic and pharmacodynamic modeling of humanized anti–factor IX antibody (SB 249417) in humans
Authors: Chow Fung‐Sing , Benincosa Lisa J. , Sheth Sunita B. , Wilson Douglas , Davis Charles B. , Minthorn Elisabeth A. , Jusko William J.
Published: August 2002

Background

SB 249417 is a humanized anti‐factor IX/IXa antibody that, on administration to rats and monkeys, produces an immediate suppression of factor IX activity and prolongation of activated partial thromboplastin times (aPTT).

Objective

Our objective was to establish the pharmacokinetics of SB 249417 and to explore its effects on factor IX activity levels and aPTT in humans.

Methods

In this phase I, single‐blind, randomized, placebo‐controlled, parallel‐group, single intravenous infusion study, individual and mean data from a total of 26 healthy volunteers at 5 dosing levels were analyzed. A 2‐compartment pharmacokinetic model was used in the analysis of total SB 249417 concentration‐time profiles. A modified indirect‐response model was used, with the total concentration indirectly serving as the driving force for the suppression of free factor IX concentration (as assessed by factor IX activity). The aPTT was related to factor IX activity with a biexponential equation, and a population approach was used to generate posterior parameter estimates for the individual fittings.

Results

Mean parameter estimates from individual fittings are 0.092 L/kg for volume of distribution, 0.15 L/kg for steady‐state volume of distribution, and 0.0021 L/kg per hour for systemic clearance. The model described well the factor IX activity and aPTT time course in response to SB 249417 at 5 dose levels. The estimated half‐life of factor IX in blood was 21 hours.

Conclusions

This model was stable and robust in fitting both mean and individual data. Endogenous factor IX baseline levels and dose were the major determinants of the decline in factor IX activity during the infusion period. Thereafter the recovery of factor IX activity was governed solely by the endogenous factor IX turnover rate.

Clinical Pharmacology & Therapeutics (2002) 71, 235–245; doi: 10.1067/mcp.2002.122276
Pharmacokinetic and pharmacodynamic modeling of the antiplatelet and cardiovascular effects of cilostazol in healthy humans
Authors: Woo Su Kyung , Kang Won Ku , Kwon Kwang‐il
Published: August 2002

Objective

Cilostazol is an antiplatelet agent with vasodilating properties. It has been used to treat patients with peripheral ischemia, such as intermittent claudication. We used a pharmacokinetic‐pharmacodynamic model to analyze the relation between the plasma concentration of cilostazol, the inhibitory effect of the drug onplatelet aggregation, and the cardiovascular effects of the drug on healthy humans.

Methods

A single oral dose of 100 mg cilostazol was administered to 20 healthy volunteers. Serial blood sampling and pharmacodynamic measurements were performed up to 48 hours thereafter. The effects of cilostazol on platelet aggregation, blood pressure, and heart rate were measured during the same period. The plasma concentration of cilostazol was measured with a validated HPLC method that entailed ultraviolet detection. The time courses of plasma cilostazol concentration, platelet aggregation, and cardiovascular effects were analyzed by means of pharmacokinetic‐pharmacodynamic modeling with the program ADAPT II.

Results

The plasma concentration‐time course followed a 2‐compartment model. Mean peak concentration was775 ng/ml approximately 3.65 hours after administration of cilostazol. The maximal effect on platelet aggregation wasa 31.14% reduction 6.05 hours after administration. No significant difference in systolic blood pressure was found. The maximal increase in heart rate was 13.49%, whereas the maximal decrease in diastolic blood pressure was 29.51%. Both peak effects were detected approximately 6 hours after administration of the drug. Platelet aggregation and cardiovascular effects (change in diastolic blood pressure and heart rate) were analyzed with the effect‐link sigmoid maximal effect model.

Conclusion

This pharmacokinetic‐pharmacodynamic model successfully described the relation between plasmaconcentration of cilostazol and the antiplatelet and cardiovascular effects of the drug.

Clinical Pharmacology & Therapeutics (2002) 71, 246–252; doi: 10.1067/mcp.2002.122474
Impact of CYP2C9 amino acid polymorphisms on glyburide kinetics and on the insulin and glucose response in healthy volunteers
Authors: Kirchheiner Julia , Brockmöller Jürgen , Meineke Ingolf , Bauer Steffen , Rohde Wolfgang , Meisel Christian , Roots Ivar
Published: August 2002

Background

Glyburide (INN, glibenclamide) is a second‐generation sulfonylurea antidiabetic agent with high potency. We hypothesized that glyburide may be a substrate of cytochrome P450 2C9 (CYP2C9), an enzyme that has two low‐activity amino acid variants‐Arg144Cys (CYP2C9*2) and Ile359Leu (CYP2C9*3). We explored the impact of these polymorphisms on glyburide pharmacokinetics and the effects on insulin and glucose concentrations.

Methods

Twenty‐one healthy volunteers who represented all possible combinations of the two variant alleles were studied (genotypes CYP2C9*1/*1, *1/*2, *2/*2, *1/*3, *2/*3, and *3/*3). They received a single oral dose of 3.5 mg glyburide followed by 75 g glucose at 1, 4.5, and 8 hours after administration of glyburide. Glyburide was quantified in plasma by reversed‐phase HPLC. Venous blood concentrations of glyburide, insulin, and glucose were analyzed with a population pharmacokinetic‐pharmacodynamic model by use of NONMEM statistical software.

Results

Pharmacokinetics of glyburide depended significantly on CYP2C9 genotypes. In homozygous carriers of the genotype *3/*3, total oral clearance was less than half of that of the wild‐type genotype *1/*1 (P < .001). Correspondingly, insulin secretion measured within 12 hours after glyburide ingestion was higher in carriers of the genotype *3/*3 compared with the other genotypes (P = .028), whereas the differences in glucose concentrations were not significant.

Conclusions

Carriers of the CYP2C9 variant *3 had decreased oral clearances of glyburide. This confirms that glyburide is metabolized by CYP2C9. Corresponding differences in insulin plasma levels indicated that dose adjustment based on CYP2C9 genotype may improve antidiabetic treatment.

Clinical Pharmacology & Therapeutics (2002) 71, 286–296; doi: 10.1067/mcp.2002.122476
Expertise and the Perception of Kinematic and Situational Probability Information
Authors: Abernethy Bruce , Gill Danny P , Parks Sheri L , Packer Stephen T
Published: August 2002

Two experiments were conducted on the nature of expert perception in the sport of squash. In the first experiment, ten expert and fifteen novice players attempted to predict the direction and force of squash strokes from either a film display (occluded at variable time periods before and after the opposing player had struck the ball) or a matched point-light display (containing only the basic kinematic features of the opponent's movement pattern). Experts outperformed the novices under both display conditions, and the same basic time windows that characterised expert and novice pick-up of information in the film task also persisted in the point-light task. This suggests that the experts' perceptual advantage is directly related to their superior pick-up of essential kinematic information. In the second experiment, the vision of six expert and six less skilled players was occluded by remotely triggered liquid-crystal spectacles at quasi-random intervals during simulated match play. Players were required to complete their current stroke even when the display was occluded and their prediction performance was assessed with respect to whether they moved to the correct half of the court to match the direction and depth of the opponent's stroke. Consistent with experiment 1, experts were found to be superior in their advance pick-up of both directional and depth information when the display was occluded during the opponent's hitting action. However, experts also remained better than chance, and clearly superior to less skilled players, in their prediction performance under conditions where occlusion occurred before any significant pre-contact preparatory movement by the opposing player was visible. This additional source of expert superiority is attributable to their superior attunement to the information contained in the situational probabilities and sequential dependences within their opponent's pattern of play.
Distractor Ratio Influences Patterns of Eye Movements during Visual Search
Authors: Shen Jiye , Reingold Eyal M , Pomplun Marc
Published: August 2002

We examined the flexibility of guidance in a conjunctive search task by manipulating the ratios between different types of distractors. Participants were asked to decide whether a target was present or absent among distractors sharing either colour or shape. Results indicated a strong effect of distractor ratio on search performance. Shorter latency to move, faster manual response, and fewer fixations per trial were observed at extreme distractor ratios. The distribution of saccadic endpoints also varied flexibly as a function of distractor ratio. When there were very few same-colour distractors, the saccadic selectivity was biased towards the colour dimension. In contrast, when most of the distractors shared colour with the target, the saccadic selectivity was biased towards the shape dimension. Results are discussed within the framework of the guided search model.
Visual Motion Integration for Perception and Pursuit
Authors: Stone Leland S , Beutter Brent R , Lorenceau Jean
Published: August 2002

To examine the relationship between visual motion processing for perception and pursuit, we measured the pursuit eye-movement and perceptual responses to the same complex-motion stimuli. We show that humans can both perceive and pursue the motion of line-figure objects, even when partial occlusion makes the resulting image motion vastly different from the underlying object motion. Our results show that both perception and pursuit can perform largely accurate motion integration, ie the selective combination of local motion signals across the visual field to derive global object motion. Furthermore, because we manipulated perceived motion while keeping image motion identical, the observed parallel changes in perception and pursuit show that the motion signals driving steady-state pursuit and perception are linked. These findings disprove current pursuit models whose control strategy is to minimize retinal image motion, and suggest a new framework for the interplay between visual cortex and cerebellum in visuomotor control.
Invariant Recognition of Natural Objects in the Presence of Shadows
Authors: Braje Wendy L , Legge Gordon E , Kersten Daniel
Published: August 2002

Shadows are frequently present when we recognize natural objects, but it is unclear whether they help or hinder recognition. Shadows could improve recognition by providing information about illumination and 3-D surface shape, or impair recognition by introducing spurious contours that are confused with object boundaries. In three experiments, we explored the effect of shadows on recognition of natural objects. The stimuli were digitized photographs of fruits and vegetables displayed with or without shadows. In experiment 1, we evaluated the effects of shadows, color, and image resolution on naming latency and accuracy. Performance was not affected by the presence of shadows, even for gray-scale, blurry images, where shadows are difficult to identify. In experiment 2, we explored recognition of two-tone images of the same objects. In these images, shadow edges are difficult to distinguish from object and surface edges because all edges are defined by a luminance boundary. Shadows impaired performance, but only in the early trials. In experiment 3, we examined whether shadows have a stronger impact when exposure time is limited, allowing little time for processing shadows; no effect of shadows was found. These studies show that recognition of natural objects is highly invariant to the complex luminance patterns caused by shadows.
Influence of light intensity and salt-treatment on mode of photosynthesis and enzymes of the antioxidative response system of Mesembryanthemum crystallinum
Authors: Broetto Fernando , Lüttge Ulrich , Ratajczak Rafael
Published: August 2002

The metabolic switch from C3-photosynthesis to
crassulacean acid metabolism (CAM),and the antioxidative response of
Mesembryanthemum crystallinum L. plants cultured under
severe salt stress and high light intensities, and a combination of both
stress conditions, were studied. High light conditions led to a more rapid CAM
induction than salinity. The induction time was still shortened when both
stress factors were combined. A main pattern observed in CAM plants was a
decrease in mitochondrial Mn–superoxide dismutase (SOD) activity during
the day. The activities of the chloroplastic Fe–SOD and cytosolic
CuZn–SOD were increased due to salt treatment after a lag phase, while
catalase activity was decreased. Combination of salt and light stress did not
lead to a higher SOD activity as found after application of one stress factor
alone, indicating that there is a threshold level of the oxidative stress
response. The fact that salt-stressed plants grown under high light conditions
showed permanent photoinhibition and lost the ability for nocturnal malate
storage after 9 d of treatment indicate serious malfunction of metabolism,
leading to accelerated senescence. Comparison of CuZn–SOD activity with
CuZn–SOD protein amount, which was determined immunologically, indicates
that the activity of the enzyme is at least partially post-translationally
regulated.
Notes on the Australian species described in the genus Cantharellus (Basidiomycetes)
Authors: Eyssartier G. , Buyck B.
Published: August 2002

Type specimens of Australian species of
CantharellusAdans. : Fr. are critically examined. Two,
perhaps three taxa (if C. ochraceoravus is not a
Clitocybe) among 17 belong to the genus and a short
dichotomous key is provided for these species.
Systematics of cretaceous and tertiary Nothofagoxylon: implications for Southern Hemisphere biogeography and evolution of the Nothofagaceae
Authors: Poole Imogen
Published: August 2002

Fossil woods with greatest anatomical similarity to modern Nothofagaceae are
traditionally assigned to the organ genus Nothofagoxylon
Gothan. All fossil wood records of Nothofagoxylon were
re-evaluated so that recently collected specimens from the Antarctica
Peninsula region could be assigned to taxa within this organ genus. Widespread
synonymy was found within the published records of
Nothofagoxylon, so that of the 16 described species,
only seven were retained. Six of these fossil species were found to be present
in Antarctica. In undertaking this review, some lauraceous woods assigned to
Laurinoxylon Schuster were found to be nothofagaceous.
Temporal and spatial patterns of occurrence of the
Nothofagoxylon wood type help support current views that
the centre of origin of the Nothofagaceae was within the Antarctic
Peninsula–South America region during the Campanian followed by
radiation into the lower southern latitudes throughout the Tertiary.
Short Note: Ficus rubiginosa f. glabrescens (F.M.Bailey) D.J.Dixon: a new taxonomic status for an old Bailey name
Authors: Dixon Dale J.
Published: August 2002

The basionym of Ficus rubiginosa f.
glabrescens (F.M. Bailey) D.J. Dixon is provided to
validate the change of taxonomic status.
New species of Banksieaeformis and a Banksia 'cone' (Proteaceae) from the tertiary of central Australia
Authors: Greenwood David R. , Haines Peter W. , Steart David C.
Published: August 2002

Silicified leaf impressions attributed to the tribe Banksieae (Proteaceae) are
reported from a new Tertiary macroflora from near Glen Helen, Northern
Territory and from the Miocene Stuart Creek macroflora, northern South
Australia. The fossil leaf material is described and placed in
Banksieaeformis Hill & Christophel.
Banksieaeformis serratus sp. nov. is very similar in
gross morphology to the extant Banksia baueri R.Br. and
B. serrata L.f. and is therefore representative of a
leaf type in Banksia that is widespread geographically
and climatically within Australia and that is unknown in
Dryandra or other genera of the Banksieae. The leaf
material from Stuart Creek and Woomera represents the lobed leaf form typical
of Paleogene macrofloras from southern Australia, but one
species,B. langii sp. nov., is closely similar in gross
form to Banksieaephyllum taylorii R.J.Carpenter,
G.J.Jordan & R.S.Hill et al. from the Late Paleocene
of New South Wales and similarly may be sclerophyllous. Also reported are
impressions of Banksia infructescences, or ‘seed
cones’, in Neogene sediments near Marree and Woomera, South Australia.
These fossils demonstrate the presence of Banksiinae in central Australia in
the mid-Tertiary, potentially indicating the former existence of linking
corridors between now widely separated populations of
Banksia.
Studies in the genus Galerina (Agaricales) in Australia
Authors: Wood A. E.
Published: August 2002

Descriptions are provided for 29 species and varieties, of which 21 are new,
for Galerina from Australia, mainly from New South
Wales. A key is provided for the species and line drawings illustrating the
macro-and micro-characters are also provided. The species are discussed in
relation to the world flora.
Aphyllophorales in Australasia
Authors: Buchanan Peter K.
Published: August 2002

Taxonomic knowledge of the Aphyllophorales of Australasia is reviewed. Recent
literature is cited for groups of Aphyllophorales arranged pragmatically by
type of hymenophore (polypore fungi (poroid and related lamellate taxa),
corticioid, clavarioid, hydnoid, cantharelloid, cupuloid), along with numbers
of recorded species, estimates of endemism and distinctive features of the
Australasian mycota. With the partial exception of poroid and clavarioid
fungi, the order is poorly known in the region. Their importance as pathogens,
as sources of food and medicine and as arthropod associates is discussed,
along with their relevance to biogeography. Although only limited collecting
has been undertaken and few Australasian mycologists are actively researching
these fungi, current preparation of checklists and recent taxonomic studies
indicate renewed research interest.
Mixmaster exposure to dust during mixing of wildland fire retardant chemicals
Authors: Spear Terry M. , Cannell Curtis E.
Published: August 2002

A study was performed at two air tanker/retardant bases to determine the
mixmaster’s exposure to dust derived from mixing dry fire retardant
compounds. Personal sampling for both inhalable and respirable dust was
conducted while the mixmaster mixed fire retardant compounds to form a
retardant slurry. Personal samples were also analysed for a colorant in the
retardants and hydrogen cyanide. Hazard quotients were calculated for average
and upper-end use scenarios using a risk assessment model from Labat-Anderson,
Incorporated.
The exposure analysis revealed that the 8-h time weighted average (TWA)
concentrations were within applicable occupational exposure limits for the
inhalable and respirable dust fractions as well as for the colorant and
hydrogen cyanide. When the mean inhalable exposure concentration was used to
calculate chemical intake, hazard quotients were above 1 at both retardant
bases, indicating a potential for non-carcinogenic health effects.
Exposure control methods recommended from this study include substitution of a
liquid concentrate fire retardant, installation of local exhaust ventilation
systems, good housekeeping and personal hygiene. We also recommend the use of
personal protective equipment including a filtering facepiece, half-mask
respirator; eye protection, and protective clothing such as gloves and
coveralls.
Wave Propagation in Electromechanical Structures: Induced by Embedded Piezoelectric Actuators
Authors: Wang X. D. , Huang G. L.
Published: August 2002

This paper provides an analytical analysis of the elastic wave propagation in an elastic medium induced by an embedded thin sheet piezoceramic actuator under high frequency dynamic electric loads. A new actuator model taking account of the deformation in both the transverse and longitudinal directions of the actuator is developed. The wave propagation induced by the actuator is studied using Fourier transform method and solving the resulting integral equations in terms of the interfacial normal and shear stresses. Detailed numerical simulation is conducted to evaluate the effects of the geometry of the actuator, the material combination and the loading frequency upon the load transfer and the resulting wave propagation.
High-Order Analysis of Unidirectional Sandwich Panels with Flat and Generally Curved Faces and a “Soft” Core
Authors: Rabinovitch O. , Frostig Y.
Published: August 2002

The bending behavior of a unidirectional sandwich panel with flat and generally curved faces and a flexible core in the vertical direction is investigated. The studied panels consist of an upper flat face sheet, a core of variable thickness, and a lower face sheet that can take any geometrical layout described by an analytical function. The core is assumed a two-dimensional elastic medium with shear and transverse vertical rigidities only, and the face sheets are considered as membrane and bending members made of metallic or composite materials. The term unidirectional refers here either to a beam (narrow panel) or to a wide beam (panel) undergoing a cylindrical bending. The field equations and the boundary conditions are derived via the variational principle of the virtual work and transformed from the local polar coordinate system of the curved face into the global Cartesian one. Higher order effects due to flexibility of the core in the form of nonlinear deformation fields are incorporated in the proposed analysis as a result of the closed-form solution of the field equations and are not postulated a priori. Numerical results in terms of deformations, stresses, and stress resultants are presented for some typical cases of flat-curved panels. The effect of a wide range of layouts, various boundary conditions, and the influence of manufacturing imperfections in the form of initially wrinkled face are investigated. The results demonstrate the capabilities and generality of the proposed model and present its ability to predict the high-order localized effects that characterize such panels.
Designing with “L-” and “U-” Shaped snap Fits
Authors: McMaster William , Lee Chul S.
Published: August 2002

Snap-fit designs for assembly of thermoplastic-based products provide many benefits. However, when the strain caused by the deflection of a typical cantilever snap fit cannot be designed below the allowable strain of the intended material, conventional designs must give way to alternative snap-fit designs. In these cases, a “U-” or “L-” shaped snap usually reduces the strain to an acceptable level without sacrificing the cost and performance benefits of the typical cantilever snap fit. These alternative designs can accommodate very large deflections without inducing high strains at the base of the snap-fit finger. Formulae for both the “L” and the “U” have been derived to allow for maximum deflection for a given geometry. Detailed examples of the application of these formulae, which were confirmed using finite-element analysis, are given in this paper.
Achieving Maximum Tip Displacement during Resonant Excitation of Piezoelectrically Actuated Beams
Authors: Lobontiu Nicolae , Goldfarb Michael , Garcia Ephrahim
Published: August 2002

A linear, lumped-parameter, single-degree-of-freedom model is formulated to describe the dynamic response of the first mode of a piezoelectrically-actuated cantilevered beam. The modeled system consists of two identical, symmetrically disposed piezoelectric patch actuators bonded to a uniform beam with a tip mass. Specifically, the first mode of the system is described by an equivalent mass-spring-damper system where the equivalent mass, stiffness, damping, and force are functions of the parameters of the piezoelectrically-actuated system. Experimental data are used to verify model damping and displacement. The model is then used to show that the dynamic response of the system depends upon four independent non-dimensional geometric variables. Numerical simulations are performed to graphically demonstrate this dependence and to indicate an optimal configuration for achieving a maximum deflection at the beam's free end during resonant excitation.
Study of Shear and Extensional Viscosities of Biodegradable PBS/CO2 Solutions
Authors: Ladin Dmitry , Park Chul B. , Park Simon S. , Naguib Hani E. , Cha Sung W.
Published: August 2002

The purpose of this research is to study the pressure drop profiles of biodegradable polybutylene succinate (PBS)/CO2 solutions in a slit die and to measure the rheological properties of the solutions as a function of the blowing agent concentration. A slit die with four pressure transducers has been designed to describe the effects of shear rate, temperature, pressure, and gas content on the shear viscosity and extensional viscosity of the flowing PBS/CO2 solutions. The low shear rate viscosity of the pure polymer was measured using a cone and plate rheometer. Extensive experiments were conducted to investigate the polymer/gas solution viscosities at five different shear rates, three temperatures and five gas contents. Cross-Carreau model and generalized Arrhenius equation were used to describe the shear-viscosity behaviors of PBS/CO2 solutions. The extensional viscosity of solution was modeled based on Cogswell’s equation.
Amylases and Hemicellulases in Breadmaking. Degradation By-Products and Potential Relationship with Functionality
Authors: Jiménez T. , Martínez-Anaya* M.A.
Published: August 2002

Eleven commercial enzyme preparations, based on pentosanase and/or amylase activities, were added to wheat doughs and were processed to bread. Changes in free sugars, maltodextrins and carbohydrate polymer degradation—starch and pentosans—during fermentation, baking and storage are reported, and their possible relationship to functional properties is evaluated. The main activity of preparations was endo-type, although some arabinosidase action was present, even in•-amylases without other declared activity. Dextrinogenic (low molecular weight) properties of•-amylases depended on the source, and within the same manufacturer, on the enzyme characteristics. The majority of preparations solubilized part of pentosans, changes consistent with reported enzyme composition. Storage of breads induced variations in soluble starch and solids, which were affected by the enzymes. Some low molecular weight dextrins correlated with fresh bread properties, favored crumb and starch solubilization and did not induce changes in texture during storage, whereas water-insoluble pentosans correlated with crumb elasticity and hardness during storage.
Statistical Data Analysis of Abrasive Wear Performance of Polyetherimide and Composites
Authors: Fahim M. , Indumathi J. , Bijwe J.
Published: August 2002

In this paper, abrasive wear data obtained on polyetherimide (PEI) and its four composites reinforced with short glass fibres have been statistically analysed. The statistical analysis was done to investigate the effects of individual operating parameters like load, sliding speed and abrasive paper grit size and the combined effect of same parameters, and their interactions with the contact surfaces, on the wear of PEI and composites. It was found that the combined effect of operating parameters and their interactions with the contact surfaces had a profound influence on the wear of these materials. Their influence, however, depended on the percentage reinforcement of glass fibres.
Modeling of Multi-Layer Sandwich Type Structures Using a High-Order Plate Formulation
Authors: Thomsen Ole Thybo
Published: August 2002

A general theory for the analysis of multiple layer plate assemblies consisting of interchanging high density, high stiffness layers and low density, low stiffness/compliant interface layers is presented. The high stiffness layers are modeled as generally orthotropic laminated composite plates, and the compliant interface layers are modeled as specially orthotropic solid layers only possessing stiffness in the thickness direction. The multiple layer plate theory includes the transverse flexibility of the compliant interface layers, and the formulation inherently includes a description of the global plate response as well as the local responses of the individual high stiffness and compliant layers. The capabilities of the theory are demonstrated through a numerical example involving the prediction of the complete deformation and stress fields in a 7-layer cantilever sandwich plate composed of 4 solid laminates interfaced by 3 compliant interface layers.
Optical Metrology of Adaptive Membrane Mirrors
Authors: Wagner John W. , Agnes Gregory S. , Magee Eric
Published: August 2002

Current space-based imaging platforms are significantly constrained in both size and weight by the launch vehicle. Increased payload size and weight increases the cost and decreases the selection of launch vehicles. The challenge of membrane optics in space is implementing adaptive optics technology via a membrane surface that provides at least rough order of magnitude imaging—enabling a large lightweight imaging system where small can be eliminated by processes such as real time holography.

A system was developed which categorizes surface properties of optical quality membrane material with the ability to interpret membrane mirror deformation. Membrane mirrors with adaptive control were constructed and analyzed using this system which provided sub-micron deformation data with associated optical aberrations, proving the ability of PVDF film to provide adaptive control to regions of interest on membrane mirrors. Remaining technical challenges include bonding methods and eventual multi-layer laminate bonding of the PVDF control surfaces to the membrane.
A Theoretical Examination of the Possibility of Spontaneous Combustion of Laundry in Tumble Dryers
Authors: Jones J. C.
Published: August 2002

Using Semenov boundary conditions, thermal ignition theory is applied to laundered clothing in a tumble dryer. Before the theory could be effectively applied, an analysis of heat transfer from the outside surface of the drum of the dryer to the surroundings was necessary. The final conclusion is that with neither natural nor synthetic fabrics as payload is spontaneous ignition possible.
Antiretroviral Resistance: Mechanisms, Detection and Clinical Implications
Authors: Sharma Roopali
Published: August 2002

Widespread use of antiretroviral agents and the epidemic of human immunodeficiency virus (HIV) strains resistant to these drugs have raised a lot of issues including the biology and clinical implications of HIV resistance, reliability of resistant assays and their role in clinical practice. In May 2000, the International AIDS panel endorsed and recommended the use of antiretroviral drug resistance testing in patients. Considerable data on HIV drug resistance testing that strongly suggest that utility of these assays may be of great value have been published and presented at major meetings. Although the genotypic and phenotypic assays are available for antiretroviral drug resistance testing, the testing has certain limitations. The role of these resistance assays is not clearly defined in clinical practice. Prospective studies are needed to define the long-term benefits of these assays. HIV drug resistance testing in the near future may become an important tool and standard of practice for patients infected with HIV. Clinicians caring for HIV-positive patients should be familiar with the antiretroviral drug resistant assays.
Kinetics of Ethanol and Acetaldehyde Production in Fermenting Wheat Dough by Laser-Based Trace Gas Detection
Authors: Tomás S. , Harren F. J. M.
Published: August 2002

The fermentation process of wheat dough was studied by laser-based trace gas detection. A CO-laser-driven photoacoustic spectrometer was used to monitor simultaneously, in real time, the ethanol and acetaldehyde production rates of two commercial types of active dry yeast ( Saccharomyces cerevisiae) in wheat dough substrates. Both types of yeast, Oand B, produced ethanol for 5 hours. Acetaldehyde was yielded only during 100 minutes by the yeast O, whereas the yeast Bgenerated this compound for 3.5 hours. The total ethanol and acetaldehyde productions amounted to 1.50 mL/g dough and 4.5 µ L/g dough in the Ocase, and 0.84 mL/g dough and 14.75 µ L/g dough, in the Bcase, respectively. The yeasts were also tested for their ability tometabolize mixes consisting of the control wheat dough substrate and extra amounts of glucose or maltose. Both types of yeasts showed a similar ability to consume the added glucose, however, only the yeast Bwas found to possess an adapted enzymatic system to metabolize maltose. This work showed the efficiency of applying photoacoustic trace gas detection to food technology research for on-line monitoring of fermenting wheat dough.
Reinforcing Masonry Walls with Composite Materials—Test Results
Authors: Jai John , Springer George S. , Kollár László P. , Krawinkler Helmut
Published: August 2002

In a previous paper, models are described for estimating the deformations and failures of masonry walls reinforced with composites when the wall is subjected to static, in-plane shear and normal loads. In this follow-up investigation, tests were performed to assess the accuracies of these models. Three types of test specimens were constructed: i) walls made of clay bricks and mortar and reinforced with chopped glass mat and epoxy resin, ii) walls made of wood bricks and reinforced with paper, and iii) beams made of wood bricks and reinforced with paper. Static, in-plane normal and shear loads were applied to each test specimen and the load versus deflection, failure load and deflection at failure were recorded. The data were compared with corresponding results generated by the models. These comparisons showed reasonable agreements between the data and the values calculated by the models.
Dynamic Modeling and Controller Design for a Piezoelectric Actuation System Used for Machine Tool Control
Authors: Mayhan Paul , Srinivasan K. , Watechagit Sarawoot , Washington Gregory
Published: August 2002

The dynamic model of a commercially available piezoelectric actuation system intended for use in a machine tool position control system is presented, and its fidelity to observed behavior evaluated. The components of the actuation system are presented and an available nonlinear dynamic model form for piezoelectric actuators, capable of representing actuator hysteresis, used as the basis for the system dynamic model. Parameters in the dynamic model are obtained from manufacturer’s specifications. The resulting actuator model is combined with a nonlinear model of the amplifier, the resulting system model forming the basis of a SIMULINK simulation. System responses based on the simulation are compared with experimentally measured responses. The agreement between simulation and experimental responses is reasonably good at low frequencies, and the model is used for preliminary closed loop position control system evaluations. Specific recommendations for improvement in model accuracy are also made.
Rate of Heat Release and Ignitability Indices in Predicting SBI Test Results
Authors: Hakkarainen Tuula
Published: August 2002

Rate of heat release and ignitability indices are applied to predict the European fire classification based on FIGRA values from Single Burning Item (SBI) tests for building products. Both indices can be calculated from cone calorimeter test results measured at 50 kW/m2. Within its validated range, the predictive procedure gives the correct classification for 90% of the products studied. The model provides a practical tool to support product development and quality control.
Imaging Transgene Expression for Gene Therapy
Authors: Sadelain Michel , Blasberg Ronald G.
Published: August 2002

Imaging transgene activity is of great interest to the development and implementation of genetically based therapies. Gene transfer in human cells and in humans is performed using either viral or nonviral vectors. Vectors are the vehicles used to transduce cells that are either cultured and destined to be transfused or implanted in patients (ex vivo gene transfer) or cells residing in the body (in vivo gene transfer). To illustrate the principles involved in imaging transgene expression, focus was given to the herpes simplex virus thymidine kinase gene (HSV1-tk) and the HSV1-tk ganciclovir “drug sensitivity” cancer treatment protocol. The imaging paradigm is based on an enzymatic radiotracer assay in which the market substrate, radiolabeled 2′-fluoro-1-β-D-arabinofuranosyl-5-iodo-uracil (FIAU), is selectively phosphorylated by HSV1-thymidine kinase and “trapped” in transduced cells. Information is presented that shows that the images of FIAU-derived radioactivity obtained using quantitative autoradiography, single photon emission computed tomography, and positron emission tomography imaging techniques reflect the level of HSV1-tk gene expression.
Polymer Matrix Woven Fabric Composites Subjected to Low Velocity Impact: Part I-Damage Initiation Studies
Authors: Naik N. K. , Sekher Y. Chandra , Meduri Sailendra
Published: August 2002

An investigation was undertaken to study the damage initiation behavior in polymer matrix laminated composite plates subjected to a transverse central low velocity point impact load. Inplane failure of the layers in the form of matrix cracking/lamina splitting and delaminations were the primary objectives of the study. The study has been carried out using modified Hertz contact law and an inhouse three-dimensional transient finite element analysis (FEA) code. The inplane failure functions and the interlaminar failure functions have been predicted using quadratic failure criteria. The inhouse FEA code was validated with other analytical studies and the experimental results in our earlier work. The present studies have been carried out on different plain weave fabric laminated composite plates, simply supported on all four sides. For comparison, impact behavior of balanced symmetric crossply (CP) laminates made of unidirectional (UD) layers and UD composites has been included. The studies have been carried out with plate dimensions of 150 mm x 150 mm with different plate thicknesses. Incident impact velocity in the range of 1 m/sec to 3 m/sec and impactor mass of 50 gm are considered. General observations on the distribution of failure functions and the initiation of damage are presented.
CONSTRUCTIVE CLASSICAL LOGIC AS CPS-CALCULUS
Authors: OGATA ICHIRO
Published: August 2002

We establish the Curry-Howard isomorphism between constructive classical logic and [Formula: see text]-calculus. [Formula: see text]-calculus exactly means the target language of Continuation Passing Style (CPS) transforms. Constructive classical logic we refer to are LKT and LKQ introduced by Danos et al.(1993).
DIRAC OPERATOR ON A CONFORMAL SURFACE IMMERSED IN ℝ4: A WAY TO FURTHER GENERALIZED WEIERSTRASS EQUATION
Authors: MATSUTANI SHIGEKI
Published: August 2002

In the previous report (J. Phys.A30 (1997) 4019–4029), I showed that the Dirac operator defined over a conformal surface immersed in ℝ3 by means of confinement procedure is identified with the differential operator of the generalized Weierstrass equation and the Lax operator of the modified Novikov–Veselov (MNV) equation. In this article, using the same procedure, I determine the Dirac operator defined over a conformal surface immersed in ℝ4, which is for a Dirac field confined in the surface. Then it is reduced to the Lax operators of the nonlinear Schrödinger and the MNV equations by taking appropriate limits. It means that the Dirac operator is related to the further generalized Weierstrass equation for a surface in ℝ4.
STRUCTURE MAPS OF SURFACE STRUCTURES
Authors: HAUCK J. , MIKA K.
Published: August 2002

The adatom positions of adsorbates like A=H, Se, Xe on (100) or (111) surfaces of bcc or ccp metals and related compounds like hcp metals, NaCl or ZnS form a square, hexagonal, honeycomb or Kagomé net. The ordered structures can be characterized by the self-coordination numbers of nearest, next-nearest and third neighbors T1, T2, T3 and the T1, T2 values plotted in structure maps for a constant ratio of vacant/occupied sites. Most experimental structures have a single coordination of all A atoms. The interactions between A atoms are attractive for chains of A atoms with T1=2 and repulsive for T1=0 or T1=T2=0. The structures with intermediate T1, T2 values can be characterized by sequences of structural units like squares or hexagons with a different occupation of the corners by A atoms.
THERMAL DESORPTION OF SODIUM ATOMS FROM THIN SiO2 Films
Authors: YAKSHINSKIY B. V. , MADEY T. E. , AGEEV V. N.
Published: August 2002

The adsorption and thermal desorption of Na from thin SiO2 films have been studied. X-ray photoelectron spectroscopy (XPS), angle-resolved XPS (ARXPS), low energy ion scattering (LEIS), temperature-programmed desorption (TPD), low energy electron diffraction (LEED) and work function measurements have been used to characterize the growth mechanism and properties of stoichiometric SiO2 films deposited onto a Re (0001) substrate. Upon deposition of Na onto SiO2 at 250 K, the first monolayer of Na exhibits ionic character, and evidence of metallic Na (plasmon features in XPS) is observed for higher coverages. TPD spectra for Na from SiO2 include a monolayer peak at ~700 K, and the multilayer peak due to sublimation of bulk Na at ~330 K. Penetration of Na into SiO2 can be induced by heating, or by He ion bombardment of a Na/SiO2 layer. The sticking probability for Na on SiO2 is ~0.5 at 250 K, and it decreases at higher substrate temperatures.
TOWARDS EXPERIMENTAL REALIZATION OF THE SUPERCONDUCTOR–SEMICONDUCTOR INTERFACE IN THE YBCO–Si COMPOSITE SYSTEM
Authors: ABO-ARAIS A.
Published: August 2002

To study the solid state and chemical interactions between Y1Ba2Cu3O7-δ and Si, resistivity and X-ray diffraction measurements were carried out on Y1Ba2Cu3O7-δ–Si x compounds with 00.12. The transition temperature Tc was found to be slightly decreased by Si addition up to x=0.08 and sharply decreased at x=0.10. The superconducting phase incompletely disappeared at x=0.12. The resistivity was increased by Si doping and its behavior was changed from a metallic to an insulator and semiconductor-like nature. All peaks of the orthorhombic phase were still present by increasing the Si ratio and new phases were produced which were indexed as mainly barium silicates. At x=0.12 the orthorhombic phase was greatly decreased and the barium silicate phases were very clearly destroying the superconducting phase.

The obtained results are discussed according to the superconductor–semiconductor composite model and with the idea of Bose–Einstein condensation. The superconductor–semiconductor composite as the YBCO–Si system seems to be a key to unlocking some secrets about the mechanisms of high Tc superconductors.