bluuebunny/crossref_metadata_2025 huggingface dataset:
Environmental Valuation Analysis, Public Deliberation, and their Pragmatic Syntheses: A Critical Appraisal
Authors: Niemeyer Simon , Spash Clive L
Published: August 2002

This paper explores how theoretical, practical and political issues are addressed differently by cost-benefit analysis and deliberative – participatory approaches to environmental policy. Theoretically rigorous approaches may prove to be too narrowly defined and so unsuitable because they neglect the requirements of practical implementation. Yet pragmatism which flaunts theoretical understanding lacks analytical power and can mislead policy. How economic methods, such as contingent valuation, compare with those from political science, such as citizens' juries, is an open question which we attempt to address. In addition, the new hybrid approach of deliberative monetary valuation is critically reviewed. A comparison of these approaches is made which draws out the difficulties of developing practical policy tools which are theoretically grounded and avoid political manipulation.
Situating Technoscience: An Inquiry into Spatialities
Authors: Law John , Mol Annemarie
Published: August 2002

This paper explores the spatial characteristics of science and technology. Originally seen as universal, and therefore outside space and place, studies in science, technology, and society (STS) located it first in specific locations—laboratories—and then in narrow networks linking laboratories. This double location implied that science is caught up in and enacts two topological forms— region and network—since objects in networks hold their shape by freezing relations rather than fixing Euclidean coordinates. More recent STS work suggests that science and technology also exist in and help to enact additional spatial forms. Thus some technoscience objects are fluid, holding their form by shifting their relations. And yet others achieve constancy by enacting simultaneous absence and presence, a topological possibility which we call here fire. The paper concludes by arguing that the ‘global’ includes and is enacted in all four of these topological systems.
Lives Lived and Lives Told: Biographies of Geography's Quantitative Revolution
Authors: Barnes Trevor J
Published: August 2002

In this paper I draw upon both biographical and sociological approaches to examine one moment in the history of geography's quantitative revolution of the late 1950s and early 1960s: the publication of Brian Berry and William Garrison's paper, “The functional bases of the central place hierarchy”, in Economic Geography in 1958. The origins of that paper are traced through the life stories—the ‘lives told‘—of the two authors. In particular, I try to connect the specific life trajectories of Berry and Garrison up until 1958 with the wider social and cultural contexts in which they lived. The theoretical impetus for the study are three literatures: the first is science studies, and especially the work of Bruno Latour and his ideas of ‘black boxing’ and ‘translation’; the second is on the history and sociology of quantification; and the third is on biography, particularly scientific biography. The broader argument of the paper is that the seemingly disembodied numbers, calculations, and precisely drawn figures and graphs that increasingly inflect human geography from the late 1950s, and found in such papers as Berry and Garrison's, are socially embedded, a consequence not of a universal rationality but of specific lives and times that infuse the very substance of the works produced.
Direct Measurement of the Curvature of Visual Space
Authors: Koenderink Jan J , van Doorn Andrea J , Lappin Joseph S
Published: August 2002

We consider the horizontal plane at eye height, that is all objects seen at the horizon. Although this plane visually degenerates into a line in the visual field, the ‘depth’ dimension nevertheless gives it a two-dimensional structure. We address the problem of intrinsic curvature of this plane. The classical geometric method is based on Gauss's original definition: The angular excess in a triangle equals the integral curvature over the area of the triangle. Angles were directly measured by a novel method of exocentric pointing. Experiments were performed outside, in the natural environment, under natural viewing conditions. The observers were instructed not to move from a set location and to maintain eye height, but were otherwise free to perform eye, head, and body movements. We measured the angular excess for equilateral triangles with sides of 2–20 m, the vantage position at the barycenter. We found angular excesses and deficits of up to 30°. From these data we constructed the metric. The curvature changes from elliptic in near space to hyperbolic in far space. At very large distances the plane becomes parabolic.
Perceptual Assumptions and Projective Distortions in a Three-Dimensional Shape Illusion
Authors: Griffiths A Fuzz , Zaidi Qasim
Published: August 2002

We examine a shape illusion, in which the balconies of a building appear to tilt up or down, depending on the viewpoint. The balconies are actually level parallelogram shapes, but appear as tilted rectangles. We measured the illusory tilts observed when parallelogram shapes are viewed above the line of sight, using three-dimensional stimuli consisting of parallelograms of various tilts viewed at different orientations. Under perspective projection, parallelism and orthogonality are not preserved. However, perspective distortions alone cannot account for the perceived tilts measured in these experiments, since observers perceived illusory tilts even for stimuli in the frontoparallel plane. We introduce a model, based on the theory that observers assume ambiguously projected three-dimensional angles to be equal to 90°, but revise their predictions on the basis of observation. In the model, perceived tilt is predicted as a weighted sum of the tilts predicted by the assumptions that the shape is rectangular, and that the shape is level (ie that the angle between the shape and the vertical backboard is equal to 90°). We prove that it is mathematically impossible for a planar rectangle to share a projection with a nonrectangular parallelogram. A less restrictive assumption that just the two leading internal angles are equal to 90° is suggested as an alternative, and it is further proven that this new configuration of angles leads to a unique perceived tilt. The relative weights in the model reflect the amount that each prediction is revised, and are shown to vary systematically with stimulus orientation. For some observers a better fit was found by replacing the level-tilt assumptions with an assumption that physical tilt was equal to the projected tilt.
Familiarisation with Faces Selectively Enhances Sensitivity to Changes Made to the Eyes
Authors: O'Donnell Christopher , Bruce Vicki
Published: August 2002

Two experiments were designed to isolate the facial information utilised in the learning of new faces. In experiments 1 and 2, two groups of subjects were each trained on different groups of faces by means of a dynamic video presentation. They were then shown both trained and novel faces in a same – different decision task, where ‘different’ trials included manipulations of internal and external facial features, and the task was to decide whether two images were identical or had a difference in one or more features. Both experiments showed that hair change was most easily detected in untrained (unfamiliar) faces. When faces had been trained (familiar), detection of eye changes was selectively enhanced and sensitivity to hair changes was maintained. While previous studies have suggested that familiar face representations are weighted towards their internal features, our experimental results show that this is due to selective enhancement of sensitivity to changes made to the eyes alone, with no reduction in the salience of the hair. Moreover, within the limits of the familiarisation used here, there was no enhancement of the representation of the other internal face features examined.
A chequered history: the taxonomy of Ficus platypoda and F. leucotricha (Moraceae: Urostigma sect. Malvanthera) unravelled
Authors: Dixon Dale J.
Published: August 2002

A revision of the species complexes of
‘Ficus platypoda’ and
‘Ficus leucotricha’ (Moraceae:
Urostigma sect. Malvanthera
Corner) is presented. A phenetic analysis of morphometric characters using
clustering techniques and multidimensional scaling was used to identify the
taxa in each species complex. Two species from each complex are recognised and
include Ficus brachypoda (Miq.) Miq. and here described
Ficus atricha D.J. Dixon from the
‘F. platypoda’ complex and
F. platypoda (Miq.) A. Cunn. ex Miq. and here
describedFicus cerasicarpa D.J. Dixon from the
‘F. leucotricha’ complex. Each Ficus species
is pollinated by a morphologically distinct pollinator wasp.
Ficus platypoda is pollinated by
Pleistodontes cuneatusWiebes.
Ficus cerasicarpa, F. atricha and
F. brachypodaare pollinated by wasps that are new
species yet to be described. The nomenclature of
F. brachypoda and F. platypoda is
discussed and a key to the species as well as notes and distribution maps are
provided for all four species.
Effect of thinning and prescribed burning on crown fire severity in ponderosa pine forests
Authors: Pollet Jolie , Omi Philip N.
Published: August 2002

Fire exclusion policies have affected stand structure and wildfire hazard in
north American ponderosa pine forests. Wildfires are becoming more severe in
stands where trees are densely stocked with shade-tolerant understory trees.
Although forest managers have been employing fuel treatment techniques to
reduce wildfire hazard for decades, little scientific evidence documents the
success of treatments in reducing fire severity. Our research quantitatively
examined fire effects in treated and untreated stands in western United States
national forests. Four ponderosa pine sites in Montana, Washington, California
and Arizona were selected for study. Fuel treatments studied include:
prescribed fire only, whole-tree thinning, and thinning followed by prescribed
fire. On-the-ground fire effects were measured in adjacent treated and
untreated forests. We developed post facto fire severity
and stand structure measurement techniques to complete field data collection.
We found that crown fire severity was mitigated in stands that had some type
of fuel treatment compared to stands without any treatment. At all four of the
sites, the fire severity and crown scorch were significantly lower at the
treated sites. Results from this research indicate that fuel treatments, which
remove small diameter trees, may be beneficial for reducing crown fire hazard
in ponderosa pine sites.
Monitoring of Fatigue Crack Growth in Steel Structures Using Intensity-Based Optical Fiber Sensors
Authors: Lee D. C. , Lee J. J. , Kwon I. B.
Published: August 2002

In this study we evaluated the potentiality of the application of intensity-based optical fiber sensors (IOFS) to the monitoring of crack growth behavior of steel structures subjected to fatigue loading. This evaluation was performed based on the sensing principle of IOFS and the fracture mechanics theory of cracked structures by the use of IOFS attached to center-cracked-tension steel specimens and a model bridge. Experimental results showed that the attached IOFS could detect the stiffness changes caused by the crack growth of steel structures. We also studied the characteristic advantages of the IOFS, such as durability to fatigue and immunity to elecromagnetic interference, compared to the strain gage. From this experimental study it can be said that the potentiality of the IOFS for practical application has been confirmed.
Vibration Suppression in an MR Fluid Damper Suspension System
Authors: Kim Kiduck , Jeon Doyoung
Published: August 2002

An MR(Magneto-Rheological) fluid damper is designed and applied to a semi-active suspension system of a quarter car model. The damping constant of the MR damper changes according to the input current and the time delay of the damper is included in the system dynamics. The passive method, LQ control and frequency shaped LQ control are compared in experiments. The advantage of the proposed frequency shaped LQ control is that the ride comfort improves in the frequency range of 4 and 8 Hz where a human is most sensitive and the driving safety improves around the resonance frequency of unsprung mass, 11 Hz. The experiments using a quarter car model show the effectiveness of the algorithm.
Present State and Future of the Intelligent Materials and Systems in Japan
Authors: Takagi Toshinori
Published: August 2002

At the 1 st conference on Intelligent Materials-ICIM'92-(Ohiso, Japan) the concept of the Intelligent Materials (IM) and how to be the material in the future were discussed by the author along the historical line of material as to hardware and software. Also, the necessity of the intelligent materials was emphasized. At the 3rd ICIM'96 (Lyon, France) the concept of the IM, the features of the "Smart" and "Intelligent" and IM as a Hierarchy with some recent examples were reported. At the 4th ICIM '98 (Makuhari, Japan), in order to introduce Japanese activities, 13 papers which received Takagi Awards were reported commemorating the conference host country Japan and those papers had been reported at IM symposium sponsored by IM Forum Japan since 1994 and those papers may provide a clue to find the future trend of IM.
Development of an Educational Assessment Plan for Doctor of Pharmacy Programs
Authors: Boyce Eric G.
Published: August 2002

The assessment of academic and student services is becoming an essential component in higher education. Program assessment is a method to collect, disseminate and use data in order to improve the academic program and the students’ experiences while enrolled in that program. A program assessment plan for doctor of pharmacy programs is now part of the accreditation standards from the American Council on Pharmaceutical Education. The organization of an assessment plan includes leadership from college/school administration and faculty, plus participation from administrators, faculty, students, alumni, employers and possibly others. The development of an assessment plan includes designing prospective activities to determine what to assess, methods to perform the assessment, collection and dissemination of assessment data, data analysis, use of the data, and assessment of the assessment plan. Assessment activities should be implemented gradually, with a focus on assessing those factors that are most important, can be readily assessed, and can be useful.
Delamination Modeling of Composites for Improved Crash Analysis
Authors: Fleming David C.
Published: August 2002

Modeling of crashworthy composite structures is limited by the inability of current generations of finite element crash codes to effectively model certain critical failure modes, such as delamination. Previous efforts to model delamination and debonding failure modes using crash codes have typically relied on ad hoc failure criteria and quasistatic fracture data. Improvements to these modeling procedures can be made by using an approach based on fracture mechanics. Finite element predictions of delamination growth using the virtual crack closure technique are implemented using the finite element crash code MSC/DYTRAN and compared with other methods of modeling delamination in finite element crash analyses. Computational results for composite double cantilever beam specimens are compared with experimental results from the literature. This investigation demonstrates the potential for improving the crash modeling of composites through improved delamination modeling. Further developments to this approach may result in improved analytical tools that can be used to model delamination using current generation crash codes.
Foams Made from Blends of Ethylene Styrene Interpolymers with Polyethylene, Polypropylene and Polystyrene
Authors: Chaudhary Bharat I. , Barry Russell P. , Tusim Martin H.
Published: August 2002

INSITE** Technology from The Dow Chemical Company has enabled the production of ethylene-styrene Interpolymers (ESI) by copolymerization of ethylene and styrene monomers. The properties of interpolymers vary significantly with copolymer styrene content. Interpolymers with up to about 45 weight percent copolymer styrene are semicrystalline and exhibit good low temperature toughness. Interpolymers with greater than about 45 weight percent copolymer styrene are essentially amorphous and range from those that have low modulus and high elongation to those that have higher modulus with unique stress relaxation and dead fold properties. Interpolymers have both aromatic and aliphatic functionality. Hence, they are compatible with a variety of other thermoplastics. Interpolymers have been commercially launched under the trademark "INDEXt Interpolymers" and are classified as E-Series (up to about 45 weight percent styrene) or S-series (greater than about 45 weight percent styrene). This paper describes the properties of blends of interpolymers with low density polyethylene (LDPE), high density polyethylene (HDPE), polypropylene (PP) and polystyrene (PS), as well as the novel and unique foams made by expanding some of these blends with physical blowing agents.
Fire-Retardant Characteristics of Water-Blown Molded Flexible Polyurethane Foam Materials
Authors: Jayakody Chandrasiri , Myers Dan , Sorathia Usman , Nelson Gordon L.
Published: August 2002

Polyurethane flexible foam materials have a wide range of industrial applications. These applications include flexible foams for packaging, polyurethane-based foam materials for seat cushions in buses, railways, the airline industry, prisons, and domestic bedding. There is a substantial need for the development of flexible molded foam materials with low heat release rates and smoke release rates. In this study, an extensive series of flexible, molded polyurethane seat cushion materials based on polymeric MDI and polyether polyols were prepared and further modified with commercially available flame retardant additives. The flame retardant behavior of these foam materials was evaluated using Cone Calorimeter (ASTM-E 1354), vertical Bunsen burner test for cabin and cargo component materials [FAR 25.853 (a), Appendix F, Part I, (a)(1)(i) and (a)(1)(ii)], and oil burner test for seat cushions [FAR 25.853 (c), Appendix F, Part II]. Several formulations that passed the 12-second vertical Bunsen burner test were identified. These include the formulations modified with Firemaster® HP-36, Decabromodiphenyl oxide/antimony oxide/Firemaster®HP-36, Fyrol® FR-2, and Fyrol® FR-2/graphite powder. A formulation modified with Antiblaze®-230 and a cross-linking agent passed both 12-second and 60-second vertical Bunsen burner tests. But, all of these materials did not pass the oil burner tests for seat cushions. Using the cone calorimeter, materials with a reduction in peak heat release rate of up to 57% were prepared and with up to a fourfold increase in char residue in the cone. However, most FR formulations showed an increase in carbon monoxide and smoke generation. Lowest peak HRR data were obtained with Firemaster® HP-36/Sb2O3 and Dow Silicones®1-9641 at 25kW/m2 and with Fyrol® FR2/cross-linker at 35 kW/m2 exposure. It appears that there is no correlation between cone calorimeter results and vertical Bunsen burner test results.
Review: Loss of Quality during the Manufacture of Canned Fish Products
Authors: Aubourg S. P.
Published: August 2002

From the moment the fish is caught till it arrives at the consumer as a canned product, raw matter is submitted to a variety of industrial steps. Thus, a storage process (namely, chilling or freezing) is needed for holding the raw material to be canned; a cooking step is normally employed for reducing moisture and inactivating endogenous enzyme activity; a rigorous thermal treatment (sterilization) is undertaken to inactivate micro-organisms; and a proper canned storage is necessary to guarantee good palatability of the product. As a result, labile and essential nutrients (proteins, vitamins, lipids, minerals) present in the raw fish are exposed to different processing conditions that can reduce the nutritional and sensory values of the final product. In the present work, detrimental changes produced in each of the steps involved in the manufacture of canned products are mentioned. This review is focused on nutritional and sensory losses in species commonly employed for canning preparation, and special attention is given to research concerning the effect of varying conditions of previous processing (chilling, freezing and frozen storage and cooking) on the quality of the final canned product. New and current technological strategies are recommended to increase the shelf life of previously stored material and to retain sensory and nutritional quality in the final canned product.
Pre-Heating of Thermoplastic Sandwich Materials for Rapid Thermoforming
Authors: Rozant O. , Bourban P. -E. , Manson J. -A.E. , Drezet J. -M.
Published: August 2002

The thermoforming of thermoplastic sandwich structures based on the same matrix polymer for the face sheets and the core requires precise temperature control both before and during forming. Two opposing requirements must be satisfied: the face sheets must be heated to above the glass transition temperature of the polymer, Tg, whereas the temperature of the core should not approach Tg in order to avoid the collapse of the foam cells. A numerical model was used to determine the optimal thermal parameters for thermoforming using an inverse method. The conductivities of the skins, the interface, and the foam were first calculated by the inverse method and then implemented in a thermal analysis. It was shown that the thermal requirements for the skins and the foam cannot all be fulfilled using a classic one-step heating route; therefore, a two-step procedure was proposed. The numerical tool allowed the principal heating parameters, namely the temperature of the heating plates and the holding and transfer times, to be determined.
Note. Occurrence of Fumonisin B1 in Spanish Corn-Based Foods for Animal and Human Consumption
Authors: Velluti A. , Marín S. , Sanchis V. , Ramos A. J.
Published: August 2002

This survey describes the fumonisin B 1(FB1) occurrence in 228 and 58 corn-based food samples from Spain for human and animal consumption, respectively. High-performance liquid chromatography (HPLC) with ophthaldialdehyde derivatization was used for the analysis of FB 1. We detected FB1 in 86% of the samples for animal consumption, ranging from 89–8757 ng/g. Four of these samples had levels of FB 1> 5000 ng/g but none of them higher than 10,000 ng/g. On the other hand, FB 1was detected in 23% of the samples for human consumption. The lowest amount of FB 1found in a positive sample was 16 ng/g, and the highest was 938 ng/g. The most contaminated samples were the wholemeal corn flours, with a range of contamination that varied from 299–938 ng/g.
Development of Soft Tribo-Sensor Using PVDF Film for Skin Surface Contour Measurement
Authors: Jiang Zhongwei , Funai Katsuyoshi , Tanaka Mami , Chonan Seiji
Published: August 2002

This paper is concerned with a basic experimental study on the development of a tactile sensor for skin surface contour measurement. The sensor, imitating the finger, was constructed from an aluminum pipe as the digital phalanx, a sponge rubber sheet as the digital pulp and PVDF film as the sensory receptor. Furthermore, the sensor was covered with cellophane tape or a piece of gauze, which seemed to be an effective substitution for a fingerprint. The sensor is supposed to be moved directly along the skin surface and the skin texture would be estimated by measuring the output of the sensor. Since the signals from sensor are complex, three data processing methods, so-called Ten-point Average, Symmetrized Dot Pattern and Wavelet Transform, were introduced to evaluate the surface roughness both qualitatively and quantitatively. The experimental results obtained on some different types of paper and some parts of skin are presented. Furthermore, an efficient visual display technique and a quantitative evaluation method were proposed for the determination of skin roughness. The proposed tactile sensor shows great potential for skin surface contour measurement.
Plasticized Poly(Vinyl Chloride) Filled with Waste Leather Particles
Authors: Babanas K. , Tarantili P. A. , Andreopoulos A. G.
Published: August 2002

Waste leather granules were incorporated into poly(vinyl chloride) polymer plasticized with di-octyl phthalate. The blend was prepared by a melt mixing process using a banbury mixer. The rheological behaviour of the mixture was recorded and the filled samples were tested for their physicomechanical properties. It was found that density, wear resistance and Shore D hardness of the specimen increases, whereas the tensile properties are considerably deteriorated with the incorporation of leather particles. A concentration of 40 parts per hundred parts of resin was estimated as the upper level of leather content, satisfying the needs of the design of final products with potential applications to the footwear industry. In order to improve mechanical properties, some treatments of the leather granules were applied, such as sieving and coating with ethylene vinyl acetate copolymer solution. Both those treatments seem to improve tensile strength. An increase up to 30% was observed when coated granules were used.
Stress Induced Matrix Microcracking in Brittle Matrix Plain Weave Fabric Composites under Uniaxial Tension
Authors: Kuhn J. L. , Haan S. I. , Charalambides P. G.
Published: August 2002

A stress induced microcracking non-linear model is employed as part of an incremental and iterative hierarchical modeling procedure aiming at studying the evolution of damage in brittle matrix plain weave fabric composites, subjected to uniaxial tension. The study focuses exclusively on matrix micro-damage and its effects on the macroscopic non-linear woven composite response. For a given load increment, the requisite microstresses and associated state of matrix microcracking are updated through an iterative converging procedure that employs the woven microstress analysis model of Kuhn and Charalambides and the discrete microcracking model employed by Charalambides and McMeeking. While matrix microcracking is predicted in regions of high stress concentration at the early stages of loading, its non-linear effects on the macroscopic stress-strain curve were shown to become visible at applied normalized strain ε̂x≈≈ 1. At about the same level of applied loading, the composite effective elastic in-plane properties in the ding and transverse directions were shown to degrade non-uniformly, thus resulting in damage induced macroscopic elastic anisotropies. The evolution of matrix micro-damage with the applied load was shown to initially take place within well defined, relatively narrow bands in regions of high stress concentration. With applied load increases, the matrix microcracking zones were shown to spread outward from the center of the unit-cell within a confined region thus forming macroscopic damage zones consistent with discrete micro-fracture events such as inter-bundle matrix cracking, bundle mode I cracking, and bundle transverse matrix cracking. The results are compared with experimental results presented by Aubard, Lamon, and Allix for a brittle matrix system with similar matrix and fiber material, but less complex microstructure.
Vibration Control of Plates Using Electromagnetic Compressional Damping Treatment
Authors: Omer A. , Baz A.
Published: August 2002

A new class of structural damping treatments is introduced. This class is the Electromagnetic Compressional Damping Treatment (ECDT) which relies in its operation on a viscoelastic damping layer sandwiched between an electromagnet and a permanent magnet. Interaction between the magnets generates magnetic forces that enhance the compressional damping mechanism of the viscoelastic layer. With proper tuning of the magnetic forces, in response to the structural vibration, undesirable resonances and catastrophic failures can be avoided. The fundamentals and the underlying phenomena associated with the ECDT are investigated theoretically and experimentally.

A finite element model is developed to describe the interaction between the dynamics of flexible plates, the visco-elastic damping layer and the electro-magnetic actuators. The validity of the developed finite element model is checked experimentally using aluminum plates treated with single and multi-ECDT patches. The plate/ECDT system is subjected to sinusoidal excitations and its multi-mode response is monitored when the electro-magnetic actuator is activated or not. Several control strategies are considered to activate the electro-magnetic actuator including simple PD controllers. The performance of the uncontrolled and controlled system is determined at various operating conditions. Comparisons with conventional Passive Constrained Layer Damping (PCLD) treatments emphasize the potential of the ECDT treatment as an effective means for controlling structural vibrations.
Management of Chronic Obstructive Pulmonary Disease: A Review
Authors: Beauchesne Marie-France
Published: August 2002

Chronic obstructive pulmonary disease (COPD) affects about 14 million persons in the United States and is the only common cause of death that is increasing in incidence. Chronic management of this disorder includes nonpharmacologic interventions such as smoking cessation, immunization, nutritional support, and pulmonary rehabilitation. The pharmacotherapy of COPD is based on regular administration of bronchodilators, when symptoms are persistent. Long-acting bronchodilators have been shown to improve quality of life in patients with COPD. Ipratropium remains the anticholinergic of choice, but more specific agents with a longer duration of action should become available. Four recent large clinical trials on the use of inhaled corticosteroids (ICS) have been published. The results demonstrate that ICS do not alter the decline in lung function in patients with COPD. Patients with more severe COPD and frequent exacerbations may have a better quality of life and a reduced rate of exacerbations with ICS. Management of acute exacerbations involves three major pharmacologic treatment modalities: antibiotics, short-acting bronchodilators, and systemic steroids. Recent data shows the benefits of systemic corticosteroids in the management of acute exacerbations.
Methods of Minimising Density Gradients in Rigid Polyurethane Foams
Authors: Harbron Dale R. , Page Christopher J. , Scarrow R. Keith
Published: August 2002

This paper discusses methods to minimise density gradients in moulded rigid polyurethane foams of densities 0.35 g/cc and 0.80 g/cc. Methods examined were changing the nature and concentration of the amine catalyst, the use of high functionality isocyanates and varying the mould temperature. All methods can reduce the density gradient in moulded foam compared to a control formulation.
The Comparison Effects of Palm Oil Fatty Acid and Stearic Acid in Various Natural Rubber Compounds
Authors: Ismail Hanafi , Kamal S. K. , Mark S. E.
Published: August 2002

The effect of palm oil fatty acid (POFA) and stearic acid on dynamic properties, curing characteristics and mechanical properties of natural rubber (SMR L) and epoxidized natural rubber (ENR 50) was investigated in the concentration range of 1 to 7 phr. Results indicate that scorch time, t2, cure time, t90 and maximum elastic torque increased with increasing both acid concentrations. The incorporation of palm oil fatty acid and stearic acid in both rubbers also resulted in lower damping (lower tan δ) and lower hysteresis (lower viscous torque). The tensile modulus (modulus at 100% elongation and 300% elongation, M300) and hardness increased with increasing acid concentration whereas tensile and tear strengths increased up to a maximum value and then decreased. At similar acid concentration, stearic acid and palm oil fatty acid in ENR 50 compounds show higher M100, M300 and hardness, but lower tensile and tear strengths than in SMR L compounds.
Active Tendon Control of Vibration of Truss Structures: Theory and Experiments
Authors: Preumont André , Bossens FréDéRic
Published: August 2002

This paper proposes a strategy for the active damping of cable structures, using active tendons. The first part of the paper summarizes the theoretical background: the control law is first briefly presented and the main results of an approximate linear theory which allows to predict the closed-loop poles with a root-locus technique are mentioned. The second part of the paper reports on experimental results obtained with two truss structures representative of future space applications. Finally, the behaviour of the control system for microvibrations is investigated.
Scrap Free Alloy and Its EB-Stiffened Coating Resin
Authors: Okada Takashi , Mori Kiyotaka , Ishii Hirokazu , Nishi Yoshitake , Yamaguchi Yuriko , Yasuoka Takashi , Mitsuzawa Shunmei , Oguri Kazuya
Published: August 2002

A scrap free alloy is a new concept for materials. We introduce how to determine the composition of scrap free alloy and its coating materials. The optimum alloy composite is Al16 + 8 at% Li. Furthermore, the EB-stiffened resin is very good protective coating film for Li based scrap free alloy.
Preparation, Characterization, and Biological Activity of Amides and Esters from 8-Hydroxyquinoline-2-Carboxylic Acid and Jeffamines ED® Or Poly(Ethylene Glycol)S
Authors: Mladenova R. , Petrova Ts. , Manolova N. , Ignatova M. , Rashkov I. , Kubisa P.
Published: August 2002

New macromolecular chelators were synthesized under mild conditions by reaction of 8-hydroxyquinoline-2-carboxylic acid (8Q2COOH) with polyethers having amino end-groups (Jeffamines ED®) or poly(ethylene glycol)s in the presence of dicyclohexylcarbodiimide and dimethylamino-pyridine. The prepared amides (8Q2CONH-POE) and esters (8Q2COO-POE) were characterized by SEC, DSC, IR, 1H and 13C NMR spectroscopy, and MALDI-TOF mass spectrometry. It was found that the polyethers had 8-hydroxy-2-quinolinyl end groups and formed complexes with Fe3+ ions. The obtained complexes were studied with IR spectroscopy and DSC. The plant tests showed that the Fe3+ complex of 8Q2CONH-POE2000 had high efficacy in the remedy of iron-deficient maize plants under hydroponic conditions.
Development of Novel Method to Create Three-Dimensional Arrangements of Particles Using Dielectrophoresis in Artificially Nonuniform Electric Field
Authors: Hase Masashi , Egashira Mitsuru , Shinya Norio
Published: August 2002

We have developed a novel method to arrange particles three-dimensionally using dielectrophoresis in suspension under an artificially nonuniform electric field. Particles can be attracted to electric field intensity maxima and are aligned parallel to an electric field. This alignment is called a "particle chain." As a result, the particle chains are formed only on micro pillars of metal preformed at selected positions on a flat electrode, because the electric field shows a maximum intensity on tips of the pillars. Two-dimensional arrangements of the one-dimensional chains lead to three-dimensional arrangements of the particles. Since uncured polymer is utilized as a suspension medium, the arrangements are stabilized by curing the polymer on heating. Using this method, we succeed in creating three-dimensional arrangements of glass beads with a diameter of 30 pLm in silicone elastomer. In addition, we confirm particle-chain formation of silica spheres with a 5 pRm diameter, which suggests possibility of three-dimensional arrangements of micron-order silica particles and submicron-order particles with a large permittivity such as BaTiO3.
Enhanced Low Frequency Transmission Loss of Light Weight Trim Panels Using PZT Inertial Actuators
Authors: Huang Wenchao , Koopmann Gary H. , Sharp Stephen J. , Chen Weicheng
Published: August 2002

One method of enhancing the low frequency transmission loss of noise into the cabin of a propeller driven aircraft or helicopter is to replace selected sections of the interior trim with stiff, ultra light panels that are driven with PZT inertial actuators. Given the proper control signals, the panels can be driven by the actuators such that their net volume velocity is minimized. Experiments are described that measure the sound transmission loss for a soft mounted, double layer corrugated aluminum panel driven by four actuators consisting of symmetrically-mounted, cantilevered beams with end masses driven by unimorph piezoelectric elements. A feedback control system is designed by serially connecting three Tow-Thomas biquad filters which are based on a Motorola LF347N integrated circuit design. Using this simple analog controller with the panel’s accelerations as an input, experimental results show that the inertial actuators mounted at the center of the panel produce up to 13 dB improvement in both vibration reduction and noise transmission loss of the panel.
Low-Cost MR Fluid Sponge Devices
Authors: Carlson J. David
Published: August 2002

A variety of robust, high-strength, MR fluids and devices that enable the benefits of controllable fluid technology are now commercially available. Commercial, mass-produced devices include rotary brakes for use in exercise equipment, real-time controllable vibration dampers for truck seats and adjustable linear shock absorbers for racing cars. Recently, a new way of using MR fluids in which the fluid is contained in an absorbent matrix has been developed. Such MR fluid sponge devices enable the benefits of controllable MR fluids to be realized in cost sensitive applications. Most of the high-cost components normally associated with a fluid filled device can be eliminated with this approach. Low-cost, controllable MR fluid sponge dampers are particularly appropriate for moderate-force vibration control problems where a high degree of control authority is desired such as a new generation of high-performance, home washing machines now being developed.
Shape Memory Alloys: Micromechanical Modeling and Numerical Analysis of Stuctures
Authors: Levitas V. I. , Idesman A. V. , Stein E.
Published: August 2002

Multiscale modeling of structures made from shape memory alloys (SMA) is presented. Starting with consideration of a single transformation event at the micro-level and averaging over the representative volume, micromechanically-based macroscopic constitutive equations are derived, which are used in Finite Element Method (FEM) code to model the behaviour of structures. Using the thermodynamic theory of phase transformations (PT) in elastic materials on the micro-level, the macroscopic associated transformation flow rule, the corresponding extremum principle and the nonconcavity of the transformation surface are derived for transformational micromechanisms of inelastic deformation due to phase transformation, twinning and reorientation of martensitic variants. A simple three-dimensional micromechanically-based model for thermoelastic martensitic PT is presented. The model is transformed to the fashion similar to that for J2-plasticity theory. It allows one to modify the FEM for elastoplasticity (including the radial return algorithm for numerical integration of the constitutive equations and calculation of the consistent tangent moduli) in order to model PT in SMA. Some axisymmetric problems for PT in SMA tubes are solved. In particular, PT regularities of a tube assembly with a SMA cylinder element are investigated at different external conditions.
The Use of Scintigraphic Imaging During Liposome Drug Development
Authors: Goins Beth A. , Phillips William T.
Published: August 2002

Liposomes, spherical lipid bilayers enclosing an aqueous space, have become an important class of drug carriers. This review describes the usefulness of scintigraphic imaging during the development of liposome-based drugs. This imaging modality is particularly helpful for tracking the distribution of liposomes in the body, monitoring the therapeutic responses following administration of liposome-based drugs, and investigating the physiological responses associated with liposome administration. Scintigraphy also can be used to monitor the therapeutic responses of patients given approved liposomal drugs. Several examples describing the potential of this imaging modality during both the preclinical formulation and clinical trial stages of liposomal drug development are included. Techniques for radiolabeling liposomes as well as methods for producing scintigraphic images are also described.
New Polyisocyanurate Catalysts Which Exhibit High Activity at Low Temperature
Authors: Okuzono Shuichi , Tokumoto Katsumi , Tamano Yutaka , Lowe Donald W.
Published: August 2002

In polyisocyanurate foam production, alkali metal catalysts of organic carboxylic acids and hydroxyalkyltrimethyl quaternary ammonium salts are traditional standards as polyisocyanurate foam catalysts. The activity of these catalysts, however, is not efficient at low temperature. Therefore, the initiation reactions are extremely delayed, and the flowability of the foam system is far too inferior. In addition, the foam exhibits shrinkage when the thickness of the sprayed layer was thin and the temperature was low while applying the sprayed foams. The combination of other tertiary amine catalysts could improve the flowability; however, the flammability of the foam would be a hazard because the isocyanurate reaction has not fully progressed.

For the improvement of the above-mentioned problems, Tosoh Corp. has developed several new quaternary ammonium salt compounds, such as Toyocat-TR20. TR20, however, should be used in conjunction with an alkali metal co-catalyst. Presently, Tosoh has succeeded in developing another new catalyst having even higher catalytic activity at low temperature, which can replace the use of the alkali metal catalyst. The new catalyst provides the low temperature dependency in the isocyanurate reaction activity compared to the traditional isocyanurate catalysts. The new catalyst provides the following advantages:

1. The catalytic activity is high.

2. The isocyanurate reaction activity at low temperature is high.

3. The initial foaming reaction is improved, thereby the rise profile is now smooth.

In this report, new quaternary ammonium salts will be introduced with comparison data using the FT-IR analytical methods, as well as the evaluation in panel and sprayed foams.
Parametric Study of Moisture and Heat Transfer in a New Rain-Screen Stucco Wall
Authors: Nehdi Moncef
Published: August 2002

The cost of repairs to leaky condominiums in southwestern British Columbia (BC) has been estimated at one billion dollars. Stakeholders have been actively trying to address the problem. Providing a drainage cavity (rain-screen) in wall claddings is emerging as the promising solution to offer a second line of defense against moisture ingress and is currently advocated by municipal authorities, designers and manufacturers of building envelope systems. However, it is not yet clear which assembly of materials will provide an optimal solution or what size of drainage cavity should be used. Designers do not agree on whether the cavity should be pressure equalized, pressure moderated or vented and to what extent. The effects that the cavity will have on the drying and energy efficiency of walls also remain open questions. Since stucco has been a major cladding material in BC, extensive research to design an effective drainage cavity stucco cladding system was carried out. A detailed computer study using the “MOIST 3.0” computer model was conducted to analyze the moisture and heat transfer in a new drainage cavity system versus a conventional stucco wall. The ASHRAE WYEC hourly weather data for the city of Vancouver along with the variable indoor relative humidity model were used as input. Results show superior characteristics of the proposed drainage cavity cladding system. Several residential projects, including multifamily buildings, have been constructed using the new rain-screen system, which is exhibiting good performance.
ER Fluid Finishing Using Rotating Electrode
Authors: Akagami Y. , Asari K. , Jeyadevan B. , Fujita T. , Umehara N.
Published: August 2002

The solids in the particle dispersion type functional fluid have been found to reciprocate between electrode under AC field at low frequencies. This promotes the continued dispersion of the solids. Here, we have tested the positive use of this phenomenon in finishing process and have found that the process is assisted positively or negatively depending on the strength of applied electric field and the pressure applied to the finishing pad. The optimum electric field strength and pressure are 3.5 kV/mm and 24 kPa.
Transverse Moduli Effect on Dilatation and Through-Thickness Poisson’s Ratio of Composite Laminates
Authors: Yeh Hsien-Liang , Yeh Hsien-Yang
Published: August 2002

In this paper, an investigation of the effect from the transverse elastic moduli of the lamina on the through-thickness Poisson’s ratio and the dilatation for a general class of randomly-oriented composite laminate is presented. A dimensionless mathematical model has been used to study the influence of the various transverse elastic moduli E2 and E3 of lamina on the through-thickness Poisson’s ratio and the dilatation of the laminate. The results from the analysis of this dimensionless mathematical model will provide a set of general guidelines for designing the value of through-thickness Poisson’s ratio and the dilatation of the composite laminates to meet various requirements in engineering application.
Application of Ultrasonic Spectroscopy for Hydrolytic Damage Detection in GRFC: Correlations with Mechanical Tests and Microscopic Observations
Authors: Jayet Y. , Gaertner R. , Guy P. , Vassoille R. , Zellouf D.
Published: August 2002

This study concerns the ability of ultrasonic waves to detect the damage caused to polymer composites during water immersion. The acoustical parameters such as velocity and attenuation are linked to the viscoelasticity and microstructure of the propagation medium. For ultrasonic propagation, composite materials are dispersive, so their acoustical parameters are measured by means of pulsed ultrasonic spectroscopy.

Model samples with certain properties are chosen in order to isolate the different damage mechanisms. In these conditions, the results of ultrasonic tests during hydrolytic aging allowed us to correlate the evolution of acoustical parameters to the damage level and nature. The ultrasonic results have been validated by complementary mechanical tests and microscopic observations carried out on the same samples.

From these results, it is possible to implement a practical procedure allowing the damage quantitative evaluation from ultrasonic velocity and attenuation measurements. The damage mechanism is identified through a detailed analysis of the velocity and attenuation dispersion laws.
Sensor Validation for Smart Structures
Authors: Friswell M. I. , Inman D. J.
Published: August 2002

Structures with a large number of embedded sensors are becoming more common, and this refined spatial information can be used to advantage in damage location and model validation. These sensors could be accelerometers, strain gauges, piezoceramic patches, PVDF film sensors, or optical fibre sensors. This approach requires that the sensors be functioning correctly, which on a smart structure operating in the field should be continuous and automatically monitored. This paper considers possible approaches to sensor validation, based on the assumption that a model of the structure is available. The aim is to make use of the natural data redundancy, because there will be more sensors than modes in the data. The validation approaches considered are based on hypothesis testing based on a number of techniques, such as modal filtering. The methods are demonstrated on simple examples that exercise their strengths and weaknesses.