Polyester Sheet Research Articles

A patch coating method for preparing biocatalytic films of Escherichia coli.

A method has been developed for immobilizing viable but nongrowing Escherichia coli in highly uniform patches. The patches consist of a thin layer of bacteria in acrylate vinyl acetate covered with a thin layer of the same polymer devoid of bacteria and sealed by the edges. This method permits study of immobilized cell physiology in biocatalytic films by the assay methods used for suspended cells. Large numbers of patches of immobilized E. coli can be generated on metal or polyester sheets. Those described here are 12.7 mm in diameter; in them the cell layer is 30 microm thick and contains more than 5 x 10(8) viable cells. The method allows the cell-plus-polymer layer and the polymer sealant to be varied in thickness from 5 to 60 microm and from 7 to 80 microm, respectively. No leakage of cells was detected from 87% of the patches during 15 days of rehydration. Culturability of the immobilized cells, released by shaking the cells out of the porous polymer layer, was 80% of pre coating culturability. E. coli beta-galactosidase activity and measurements of total RNA and DNA from immobilized and suspended cells indicated that cells immobilized in the thin polymer layer have higher specific beta-galactosidase activity and a slower total RNA degradation rate than suspended cells over 15 days.

Sound absorbing article and method of making same

A sound dampening glazing, for example an automotive windshield, in one embodiment of the invention includes a pair of glass sheets having facilities therebetween. In cross section and moving from one glass sheet to the other, the facilities include a polyvinyl butyral sheet, an intermediate sheet having a surface harder than the surface of the interlayer to smooth the interlayer surface e.g. an intermediate polyester sheet, a sheet of dampening material, a polyester sheet, a polyvinyl butyral sheet. In another embodiment, the automotive windshield has two sheets of dampening material, the sheets have sound dampening properties in different temperature ranges to as to provide the automotive windshield with sound dampening properties over a wider temperature range. Methods for making the glazings of the instant invention are also disclosed.

Chemical bath deposition of {111} textured mercury(ii) selenide thin layers on transparent polyester sheets

A novel method for mercury(II) selenide thin film deposition on transparent polyester sheets is presented. The method is based on chemical bath deposition in alkaline media, the chemical reaction involved being hydrolytic decomposition of selenosulfate. X-Ray analysis confirmed that the deposited material is {111} textured mercury(II) selenide. The sheet resistances of the annealed films are about 1.32 kΩ cm–2 and for as-deposited samples are about 10 times higher. The absorption onset is strongly blue-shifted from the bulk value. This is attributed to size quantization in the ca. 8 nm nanocrystals.

Charge Coupled Device Optics System for Simultaneous Measurement of Multiple Reactions in a Microplate

There is considerable interest in the application of Charge Coupled Device (CCD) technology to the challenges of modern analytical chemistry (1)(2)(3) . CCD optical devices provide high photometric sensitivity and low optical noise and can be applied to both photometric and image analysis. These devices are of great interest in application to new state-of-the-art multiple function automated clinical analyzers. A CCD spectrophotometer has been developed by DevTec, Inc. for the simultaneous measurement of multiple reactions in a microplate format (4) . The device consists of a Peltier-cooled-head Spectra Source CCD camera with a 192 × 165 pixel detector array, a 16-position interference filter wheel for wavelength selection, focusing optics for viewing a 96-well microplate, a light source for plate illumination, a fluidics module for automatic multiple sample and reagent handling, a motorized tray for microplate positioning for fluid loading and CCD luminometry, and a computer. The computer controls camera shutter speed, interference filter selection, the fluidics module, and the microplate positioning tray and serves as a user interface. We evaluated the precision and linearity of the CCD system while making absorbance measurements of samples in microplates and assessed the performance of the system with common serum assays. Within-well precision. The precision of successive measurements taken in the same well was evaluated by measuring the transmission of 500 nm light transmitted through an empty microplate, with one to four layers of deep dyed polyester color filter sheets placed under the microplate. The colored polyester sheets used were a nymph pink (filter no. 195) deep dyed polyester color filter (The Great …

Thermoelastic and Creep Analysis of a Reinforced Plastic Interrupter Shell Assembly

In the present paper an interrupter shell assembly that forms an essential part of electrical switch gears is considered for creep analysis and subjected to thermal loads in addition to static leads actuated by circuit breakers. This exercise forms a part of the design evaluation of a new product. The shell is made out of a high strength fiberglass reinforced thermoset polyester sheet molding compound. A conventional finite element formulation based on the classical theory of semicoupled thermoelasticity is employed. The creep phenomenon is considered as an initial strain problem and a time hardening law is followed for creep analysis in the secondary zone. The structure is discretized by bilinear thick and thin flat shell isoparametric elements. Results show the contrasting deformation patterns, creep and thermomechanical stresses with the strains for two temperature cases. Creep characteristics of the shell are depicted for the entire service life of the component.

Impedance measurements on cement paste

The present paper is devoted to the study of the high frequency region of the impedance spectrum, and focused at determining the origin of the time constants in the impedance and their relation to the dielectric properties of cement paste. The origin of the intermediate frequency capacitive range was investigated by intercalating polyester sheets between the paste sample and the graphite electrodes. It was concluded that the dielectric constant of cement paste can be determined only when impedance measurements are performed to frequencies higher than 10 MHz. Oven dried cement paste presents a single almost perfect capacitive behaviour with a dielectric constant, ε, below 10. In partially moistened cement paste the higher frequency range gives a reasonable ε (≈80) for awater containing material. It is concluded that the interpretation of the high values of ε in terms of the DAF effect does not seem correct.

Solvent-resistant carbon electrodes screen printed onto plastic for use in biosensors

A three electrode design using solvent resistant materials is reported, enabling the production of screen printed electrodes for use in biosensor applications involving water-miscible organic solvents. Heat stabilised polyester sheets were used as base materials in combination with carbon basal tracks and an epoxy-based polymer protective coating. The new electrodes avoid problems with solvent induced baseline shifts displayed by conventional screen-printed electrodes. The material for the underlying basal track has been changed from silver to carbon ink to reduce the number of materials involved in the production and avoid possible interferences. In addition, the design is readily applied in biosensor applications. Different methods for the incorporation of a rhodium catalyst are discussed. The application of the electrode system modified with the rhodium catalyst for the amperometric detection of hydrogen peroxide in different concentrations of methanol, isopropanol and ethanol is demonstrated.

埋込み方式，盛土方式で根域制限栽培したブドウ‘ピオーネ’樹の生育と果実発育の比較

The buried and raised soil bed systems which restrict root volume were compared for their effects on root environment, vine growth, and fruit development of 'Hone' grapes. In the buried beds, the soil and roots were enveloped with a polyester sheet that allowed free movement of moisture but which roots did not penetrate. In the raised beds, the root zones were sub-divided into two types: 1) isolated at the ground level with a plastic sheet, and 2) non-isolated.The characteristics and / or advantages of the buried bed system over those of the raised bed system are: a) the soil temperature was 0.8 to 1.7 °C higher from April to June; b) soil moisture changed slower so that it required less frequent irrigation; c) new primary and secondary roots were longer and their peroxidase activity was higher; d) leaf nitrogen and chlorophyll contents were higher; e) photosynthetic rate of leaves was faster during anthesis and berry set; f) shoot growth was more vigorous, and g) growth of berries, development of skin coloration, accumulation of total soluble solids content (TSS), and decrease in acid content were hastened.The above findings indicate that the buried bed system is suitable for dry regions because it promoted better vine growth and berry quality and required less frequent irrigation compared with the raised bed system.

Surface Effects of Plasma Treatments on Some Biodegradable Polymers.

Some biodegradable polymers of as poly(γ-lactone) and poly(succinate) were surface-treated by glow discharge plasmas under an appropriate condition, and the effects were investigated with respect to the weight loss, surface morphology change, and bio-degradation. The weight loss rates by oxidative plasmas were in general higher than those for a polyester sheet made of poly (ethylene terephthalate). After glow discharge treatments, the characteristic surface morphology appeared by the observation of scanning electron microscopy (SEM). Surface became more wettable, and activated by plasma treatments. Bio-degradation of these polymers was investigated in composts under appropriate condition, and the effects were discussed.

Conductive coating films based on low density In2O3 powders and polymer latexes

Several kinds of conductive coating films were prepared from a low-density indium(III) oxide powder (which was employed because it provides a much higher volume for the same weight) and polymer latexes. The low-density In2O3, which is an electrically conductive pigment, was prepared by pyrolysis followed by the combustion of water-swellable polymer microspheres imbibed with In(NO3)3, the precursor of In2O3. Either acrylamide/N,N'-methylenebisacrylamide or poly(vinylalcohol)/glutaricdialdehyde was used to generate spherical hydrogel particles. The polymer latexes with which the In2O3 was mixed had a soft core and a hard shell structure to ensure that the coating film has suitable mechanical properties in addition to conductivity. Acrylonitrile/butadiene/styrene copolymer ABS or acrylonitrile/butylacrylate/styrene copolymer ABAS latexes were used as binders for the conductive pigment. The powder coating followed by hot pressing, the water-borne coating consisting of low-density In2O3 and polymer latexes followed by curing, or the colloidal dispersion coating was used to deposit flexible conductive coating films on polyester sheets. The conductive pigment density and the polymer latexes' size and flowability are the factors that affect the characteristics of the film. We found that the colloidal suspension coating procedure based on ABAS latexes achieves better electrical and mechanical properties for the coating films. © 1996 John Wiley & Sons, Inc.

Thin-film-heater thermal conductivity apparatus and measurement of thermal conductivity of silica aerogel

An apparatus was developed for the measurement of thermal conductivity under steady conditions. The apparatus uses a 10 nm thick gold film heater that is coated on a polyester sheet. The important advantages of this heater are spatial uniformity of the heat generation and a small thickness. The apparatus is compact and has only a small edge loss of heat. The apparatus was used to measure the thermal conductivity of silica aerogel. The heat transfer modes in silica aerogel include gas and solid conduction and thermal radiation. The experiments provide results for the total heat transfer and hence, total (apparent) thermal conductivity. The separate solid and radiative contributions were obtained from analyses of the energy transfer. The solid conductivity of silica aerogel varies with temperature more slowly than the radiative conductivity does. The Rosseland absorption coefficient of silica aerogel decreases with temperature. Assuming one-dimensional heat transfer, the uncertainty of the results for the thermal conductivity is about 5.5%. A three-dimensional analysis is used to evaluate the validity of the assumption of one-dimensional heat transfer in the apparatus. The results shows that the assumption of one-dimensional heat transfer in the apparatus results in a reduction of the thermal conductivity of 1.7% at 20°C and a 7.3% reduction at 90°C.

Color-based image processing to measure local temperature distributions by wide-band liquid crystal thermography

This study presents a color-image-processing procedure for non-intrusive local temperature measurements by thermochromic liquid crystals (TLCs). The image evaluation software is completely independent of the color detection and acquisition hardware. This allows to use a wide variety of hardware solutions. An easy reproducible calibration of camera and light source is presented. The dependence of the detected hue values on intensity is investigated and further the hueversus temperature relation is studied. Sprayable TLC formulations and TLC-coated polyester sheets are studied and compared with regard to their signal-to-noise ratio and the dependence of their hue values on illumination and viewing angle. Furthermore, a method to investigate the hue resolution is presented. The relation between the resolution of hue values and the illumination intensity and its influence on signal noise is discussed for the first time for TLC applications. Different techniques of signal noise reduction are implemented in the image processing system. Their effects on the signal noise level are discussed. As an example the two dimensional temperature distribution caused by wing-type vortex generators in a channel flow is given.

Demineralization of dentine grooves in vitro.

Caries mainly occurs at retention sites for plaque such as pits, fissures, margins of restorations and interproximal sites. An in vitro model was developed to investigate dentine caries in narrow gaps. Forty bovine coronal dentine discs were covered with bonding agent. In 20 discs, two grooves, 200 and 340 mu m wide and 500 mu m deep, were sawn to mimic fissures. In the 20 other discs, a 1-mm-wide groove was made and, after polyester sheets were placed against both walls, filled with composite. After curing of the composite and removal of the sheets, grooves of 22 mu m remained at the borders of the restoration. All grooves were exposed to 8% methylcellulose gel 0.1 M lactic acid at pH 4.8 for 1 week. Demineralization was determined by microradiography of sections sawn out of the center of the discs. The walls of the grooves showed subsurface lesions, which decreased in size towards the base of the grooves. The average mineral losses (vol % x mu m) at the entrance of the 22-, 200- and 340-mu m-wide grooves were 1,112 (SD 370), 1,277 (293) and 1,277 (255), halfway down the groove 218 (150), 659 (244) and 797 (207) and at the base of the groove 140 (88), 285 (145) and 504 (205), respectively. Analysis of variance and Tukey's B test showed that the average mineral losses from grooves of different width and from sites at different depth were all significantly different at p<0.05 level, but not for the mineral losses from the entrance of the two wider grooves and from the two lower sites in the narrowest groove. The reduced mineral loss in the two narrower groove widths is assumed to be caused by the more limited inward diffusion of acids and outward diffusion of mineral ions through the methylcellulose gel.

Cure Characterization of Thick SMC Parts Using Dielectric and Finite Difference Analysis

Curing characteristics of thick composite parts have long been known to be a function of thickness and location within the parts. While cure state as a function of thickness has often been modeled, actual experimental verification has been difficult. In this work, disposable and permanently mounted dielectric sensors were used to characterize the cure in polyester sheet molding compound at various locations through the thickness of the part in a simulated molding environment. Using established tech niques, the dielectric and temperature information were combined to yield local cure state information for each sensor. Parts under five millimeters thick were found to cure rather uniformly, while parts greater than this had increasing degrees of nonuniformity in cure behavior through the thickness. Cure time differences of up to three minutes, between center and edge, were observed in parts 20 millimeters thick. These observed cure state data are compared to finite difference model predictions. The model simulations show that in thick parts, a cure "wave" develops, starting at the SMC/mold interface and proceeds toward the center of the part. The "wave" increases in velocity as it moves toward the center of the part. The overall effect is that a relatively uniform cure rate is observed at the SMC/mold interface while in the middle of the SMC part, a long induction period occurs, followed by an extremely fast cure. The model predictions, which are confirmed by the sensor cure data, may be used to predict the behavior and molding cycle time required for new parts during the design process.

Disposable clark oxygen electrode using recycled materials and its application

This paper describes a remarkably inexpensive disposable Clark oxygen electrode fabricable using recycled materials and without expensive and time-consuming processes. The sensor consists of polyester sheet on which the cathode and anode patterns are deposited by vacuum evaporation, copier paper to hold the electrolyte, and gas-permeable membrane. Although deceptively simple in terms of structure and fabrication, the electrode performs well as an oxygen and proves to be suprisingly durable. Its 90% response time is between 60 and 70 s, with a good linear relationship between generated current and dissolved oxygen concentration. Although designed to be disposed of after one use, the electrode demostrates a lifespan exceeding 60 h, with very low current drift. The oxygen electrode has been applied to disposable glucose sensor. Its response time is between 60 and 70 s, and a linear relationship is obtained between 20 μM and 1.4 mM glucose. The sensor shows excellent selectivity and is applicable to urine testing.

Electroconductive copper selenide films on transparent polyester sheets

Electroconductive thin films of copper selenide (Cu 2Se) were deposited on transparent polyester sheets by a simple electroless deposition technique based on hydrolytic decomposition of selenosulfate in alkaline aqueous solutions. X-ray analysis confirmed that the deposited material is polycrystalline Cu 2Se. Surface resistivities of the films are about 50–500 ohms/square, depending on the experimental conditions. Optical spectra revealed that the Cu 2Se films obtained are fairly transparent in the visible region, while the transmittance drops substantially in the near-infrared region. This suggests a possible use of these films as microwave (infrared) shielding coatings. The deposited films are p-type semiconductors with an optical energy bandgap of 2.33 eV.

Orientation distribution of liquid‐crystalline polyester sheets studied by polarized infrared spectroscopy

AbstractPolarized infrared spectroscopy was applied to evaluate the orientation distribution in extrusion‐molded sheets of a liquid‐crystalline copolyester consisting of 73 mol % of 4‐hydroxy benzoic acid units and 27 mol % of 2‐hydroxy‐6‐naphthoic acid units. The surface orientation function was evaluated from the polarized attenuated total reflection/Fourier transform infrared spectra and the polarized specular reflection spectra. In the case of the specular reflection method, the absorption and refractive indices were obtained from the specular reflectance using the Kramers–Kronig relation and the Fresnel equation. On the other hand, the microscopic orientation functions inside the sheets were evaluated by Fourier‐transform infrared microspectroscopy. The polarized FTIR microspectra of microtomed section of sheets were measured in a microscopic domain as small as 40 μ at various positions from the center of the sheet. The surface orientation function was shown to be higher than the interior orientation function. Orientation functions obtained by the spectroscopic techniques are lower than crystal orientation functions determined by wide‐angle x‐ray diffraction, implying that the crystal orientation function is higher than the orientation function of noncrystalline molecular chains. The orientation distribution in the sheet is discussed in relation to the morphological structures studied by scanning electron microscopy. © John Wiley &amp; Sons, Inc.

Flow-related responses of intracellular inositol phosphate levels in cultured aortic endothelial cells.

In vitro and in vivo evidence indicates that hemodynamic wall shear stress evokes a diversity of biological responses in vascular endothelial cells, ranging from cell shape changes to alterations in low density lipoprotein receptor expression. The signal transduction mechanisms by which the level of fluid mechanical shear stress is recognized by the endothelial cell and translated into these diverse biological responses remain to be elucidated. The present study focuses on the association between the onset of elevated shear stress and activation of the phosphoinositide signal transduction pathway, as measured by the intracellular release of inositol phosphates, in cultured bovine aortic endothelial cells (BAECs). BAECs were seeded, grown to confluence on large polyester sheets, and preincubated with 0.3 microCi/ml [3H]inositol for 24 hours before insertion in parallel-plate flow chambers for exposure to high shear stress (HS) at 30 dynes/cm2 or low shear stress (LS) at < 0.5 dyne/cm2 for periods ranging from 15 seconds to 24 hours. The induction of HS was associated with an early, transient but significant increase (142%, HS/LS x 100%) in inositol trisphosphate (IP3) measured at 15 seconds of shear stress exposure followed by a major peak in IP3 (189%) observed at 5 minutes after HS onset. After these initial increases, IP3 levels returned to near resting levels within 30 minutes of continued HS exposure and then continued to decline to significantly lower (75%) levels relative to LS-treated cells within 4 hours and remained lower throughout the remainder of the 24-hour HS exposure. LS-treated cells exhibited no significant changes in inositol phosphate levels throughout the 24-hour exposure periods. Exposure of BAECs to shear stress of 60 dynes/cm2 resulted in an approximately fourfold increase in IP3 levels (396%) measured at 5 minutes, almost double the levels measured in cells exposed to 30 dynes/cm2 for 5 minutes. Pretreatment of BAECs for 30 minutes with 5 mM neomycin, an inhibitor of phosphoinositide metabolism, before HS exposure inhibited both the early increases in inositol phosphates and subsequent cell elongation and alignment observed in untreated BAECs simultaneously exposed to HS without inhibiting protein synthesis. These results indicate that the exposure of cultured BAECs to elevated wall shear stress is associated with an early biphasic IP3 increase followed by a resetting of intracellular inositol phosphate concentrations to levels below that observed in static cultured BAECs. Furthermore, neomycin inhibition of this IP3 response to shear stress is associated with an inhibition of one of the major endothelial biological responses to shear stress, i.e., cell shape change and orientation.(ABSTRACT TRUNCATED AT 400 WORDS)

Comparison of Reporting Methods for Root Growth Data from Transparent‐Interface Measurements

Transparent viewing planes provide a useful and popular means of observing and quantifying root growth. This study was conducted to compare root growth quantification by soil depth and distribution using three tracing methods of reporting root growth: (i) traced root intensity (traced RI), (ii) traced root‐length density (traced RLD), and (iii) traced root‐length area (traced RLA). These three root‐tracing methods were compared with actual RLD and actual RLA determinations made from the bulk soil volume at the termination of the study. Creeping bentgrass (Agrostis stolonifera L.; syn A. palustris Huds.) sod was planted in clear, flexible polyethylene containers slanted at a 20° angle. During a period of ≈2 mo, root growth by depth was monitored by tracing roots onto clear polyester sheets. None of the reporting methods for traced roots generated root growth measurements equivalent to actual rooting. Traced RLD yielded the best estimates of root quantity at each soil depth, yet, generated poor root distribution estimates. Traced RLA yielded the most accurate estimate of root distribution compared with actual root distribution when data were transformed to a percent basis. Flexible, transparent polyethylene containers used for viewing‐plane measurements of root growth quantification and distribution can, when reported by these three methods, differ substantially from actual bulk soil RLD or RLA. Thus, this transparent viewing‐plane procedure exhibits the same problems inherent in root measurements from rhizotrons and minirhizotrons.

A novel system for the culture of human lung: lung development and the response to injury.

Existing methods of fetal lung organ culture are complicated and require special skills. With the use of a polyester-based plastic sheet, we have developed a simpler human fetal lung organ culture that is viable for 6 wk. This novel method permits the study of growth and differentiation, pulmonary surfactant secretion, and the response of human lung tissue to injury in vitro. Lung tissues, obtained from human fetuses ranging in gestational age from 14 to 18 wk, were cultured on the polyester sheet in Dulbecco's modified Eagle medium supplemented with 15% fetal calf serum and gentamicin. Microscopic study of the fetal lung before culturing revealed round epithelial tubules, lined by glycogen-rich columnar cells and a thick cellular interstitium. After 1 wk in culture, morphological examination showed the development and expansion of alveolar saccules and thinning of the interstitium; type I and II pneumocytes as well as fibroblasts and myofibroblasts were present. Lipid analysis of the tissues, 2 wk after the initiation of the culture, demonstrated a high percentage of dipalmitoyl phosphatidylcholine characteristic of pulmonary surfactant. Treatment of the organ culture with asbestos fibers induced type II cell hyperplasia, increased numbers of collagen fiber bundles within the interstitium, and the accumulation of multi-lamellated surfactant material within the alveolar lumens. We conclude that this organ culture system is suitable for studying lung growth, development, and injury in human tissue.