Water Permeation through Elastomer Laminates, II. SBR/EPDM

Abstract In summary, the measurements described here suggest that the temperature dependence of permeation rate had an Arrhenius behavior. Activation energies fall within the range expected for those membranes that follow activated transport mechanism. For all single elastomers, salt water exhibited higher permeation rates than did distilled water. The laminates show a directional behavior but more distinctly for distilled water than for salt water. Solubility data alone cannot, however, always account for this phenomenon.

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Water Permeation through Elastomer Laminates I. Neoprene/EPDM

Rubber Chemistry and Technology ◽

10.5254/1.3538131 ◽

1983 ◽

Vol 56 (2) ◽

pp. 357-366 ◽

Cited By ~ 9

Author(s):

Patrick E. Cassidy ◽

Tejraj M. Aminabhavi ◽

John C. Brunson

Keyword(s):

Transport Mechanism ◽

Salt Water ◽

Flow Behavior ◽

Arithmetic Mean ◽

Permeation Rate ◽

Effect Of Temperature ◽

Distilled Water ◽

Directional Dependence ◽

Water Permeation ◽

Directional Flow

Abstract Two elastomers namely, neoprene and EPDM and their laminates were used to measure the permeation rates of distilled water and salt water at 23°, 40°, and 60°C. For laminates, the rates were measured in both directions. The laminates showed a directional dependence of permeation rate. These rates were lower than the arithmetic mean of the two single layers, but higher than the theoretical calculated values. Effect of temperature on permeation rate had an Arrhenius-type behavior, and the activation energies fall within the range for those membranes that follow activated transport mechanism. Tentative mechanisms were proposed for the directional flow behavior in regard to concentration-dependent permeation.

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Mechanical Spectroscopy Study on the Light Soaking Effect on Hydrogenated Amorphous Silicon

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.184.416 ◽

2012 ◽

Vol 184 ◽

pp. 416-421 ◽

Cited By ~ 1

Author(s):

H. Mizubayashi ◽

I. Sakata ◽

H. Tanimoto

Keyword(s):

Internal Friction ◽

Temperature Dependence ◽

Amorphous Silicon ◽

Hydrogenated Amorphous Silicon ◽

Wide Distribution ◽

Activation Energies ◽

Mechanical Spectroscopy ◽

Induced Changes ◽

Mild Temperature ◽

Hydrogenated Amorphous

For hydrogenated amorphous silicon (a-Si:H) films deposited at temperatures between 423 K and 623 K (a-Si:H423Kand so on), the light-induced changes in the internal friction between 80 K and 400 K were studied. The internal friction is associated with H2motion in microvoid networks, and shows the mild temperature dependence between about 80 K and 300 K (Q-180-300K) and the almost linear increase above 300 K (Q-1>300K). BothQ-180-300KandQ-1>300Kdecrease with increasing the deposition temperature, and show the mild temperature dependence ina-Si:H623K. The white light soaking with 100 mW/cm2(WLS100and so on) below 300 K caused a change inQ-180-300Kand no changes inQ-1>300K, respectively, and the light-induced changes inQ-180-300Krecovered after annealing at 423 K. The wide distribution of activation energies for H2motions between microvoids indicate that most of neighboring microvoids are connected through windows, i.e., the microvoid networks are existing ina-Si:H, and the spatially loose or solid structures are responsible for the low or high activation energies for the H2motion between microvoids, respectively. Furthermore, the light-induced hydrogen evolution (LIHE) was observed for WLS200to WLS400in a vacuum between 400 and 500 K, resulting in the disappearance of the internal friction due to the H2motion in the microvoid network.

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Influence of Different Concentration and Ratio of a Photoinitiator System on the Properties of Experimental Resin Composites

Brazilian Dental Journal ◽

10.1590/0103-6440201701372 ◽

2017 ◽

Vol 28 (6) ◽

pp. 726-730 ◽

Cited By ~ 5

Author(s):

Caio Vinícius Signorelli Grohmann ◽

Eveline Freitas Soares ◽

Eduardo José Carvalho Souza-Junior ◽

William Cunha Brandt ◽

Regina Maria Puppin-Rontani ◽

...

Keyword(s):

Mechanical Properties ◽

Elastic Modulus ◽

Flexural Strength ◽

Tertiary Amine ◽

Water Sorption ◽

Water Solubility ◽

Distilled Water ◽

Resin Composites ◽

Amine Concentration ◽

One Way Anova

Abstract The aim in this study was to evaluate the influence of different ratio of camphorquinone/tertiary amine concentration on the flexural strength (FS), elastic modulus (EM), degree of conversion (DC), yellowing (YL), water sorption (WS) and water solubility (WSL) of experimental composites. Thus, acrylate blends were prepared with different camphorquinone (CQ) and amine (DABE) concentrations and ratios by weight: (CQ/DABE%): 0.4/0.4% (C1), 0.4/0.8% (C2), 0.6/0.6% (C3), 0.6/1.2% (C4), 0.8/0.8% (C5), 0.8/1.6% (C6), 1.0/1.0% (C7), 1.0/2.0% (C8), 1.5/1.5% (C9), 1.5/3.0% (C10). For the FS and EM, rectangular specimens (7x2x1 mm, n=10) were photo-activated by single-peak LED for 20 s and tested at Instron (0.5 mm/min). Then, the same specimens were evaluated by FTIR for DC measurement. For YL, disks (5x2 mm, n=10) were prepared, light-cured for 20 s and evaluated in spectrophotometer using the b aspect of the CIEL*a*b* system. For WS and WSL, the volume of the samples was calculated (mm³). For WS and WSL, composites disks (5x0.5 mm, n=5) were prepared. After desiccation, the specimens were stored in distilled water for 7 days and again desiccated, in order to measure the WS and WSL. Data were submitted to one-way ANOVA and Tukey’s test (5%). The groups C8, C9 and C10 showed higher DC, EM and YL means, compared to other composites. Therefore, the FS and WS values were similar among all groups. Also, C1, C2 and C3 presented higher WSL in 7 days, compared to other composites. In general, higher concentrations of camphorquinone promoted higher physical-mechanical properties; however, inducing higher yellowing effect for the experimental composites

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Temperature dependence of the optical properties in p-Cd0.96Zn0.04Te single crystals

Journal of Materials Research ◽

10.1557/jmr.2001.0301 ◽

2001 ◽

Vol 16 (8) ◽

pp. 2196-2199 ◽

Cited By ~ 4

Author(s):

H. Y. Lee ◽

T. W. Kang ◽

T. W. Kim

Keyword(s):

Optical Properties ◽

Temperature Dependence ◽

Single Crystals ◽

Reasonable Agreement ◽

Theoretical Calculations ◽

Optoelectronic Devices ◽

Activation Energies ◽

Acoustic Parameters ◽

Longitudinal Acoustic ◽

Pl Spectra

Photoluminescence (PL) measurements were performed on p-Cd0.96Zn0.04Te single crystals to investigate the dependence of the excitons on temperature. The activation energies and the longitudinal acoustic parameters of the excitons were determined from the temperature dependence of the PL spectra and were in reasonable agreement with the theoretical calculations. These results can help improve understanding for the application of p-CdxZn1–xTe single crystals in optoelectronic devices.

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Temperature dependence of planktonic metabolism in the subtropical North Atlantic Ocean

Biogeosciences ◽

10.5194/bg-11-4529-2014 ◽

2014 ◽

Vol 11 (16) ◽

pp. 4529-4540 ◽

Cited By ~ 13

Author(s):

L. S. García-Corral ◽

E. Barber ◽

A. Regaudie-de-Gioux ◽

S. Sal ◽

J. M. Holding ◽

...

Keyword(s):

Atlantic Ocean ◽

Temperature Dependence ◽

North Atlantic ◽

North Atlantic Ocean ◽

Gross Primary Production ◽

Activation Energies ◽

Community Respiration ◽

Metabolic Rates ◽

Net Community Production ◽

Different Seasons

Abstract. The temperature dependence of planktonic metabolism in the subtropical North Atlantic Ocean was assessed on the basis of measurements of gross primary production (GPP), community respiration (CR) and net community production (NCP), as well as experimental assessments of the response of CR to temperature manipulations. Metabolic rates were measured at 68 stations along three consecutive longitudinal transects completed during the Malaspina 2010 Expedition, in three different seasons. Temperature gradients were observed in depth and at basin and seasonal scale. The results showed seasonal variability in the metabolic rates, the highest rates being observed during the spring transect. The overall mean integrated GPP / CR ratio was 1.39 ± 0.27 decreasing from winter to summer, and the NCP for the subtropical North Atlantic Ocean during the cruises exhibits net autotrophy (NCP > 0) in about two-thirds (66%) of the total sampled communities. Also, we reported the activation energies describing the temperature dependence of planktonic community metabolism, which was generally higher for CR than for GPP in the subtropical North Atlantic Ocean, as the metabolic theory of ecology predicts. Furthermore, we made a comparison of activation energies describing the responses to in situ temperature in the field (EaCR = 1.64 ± 0.36 eV) and those derived experimentally by temperature manipulations (EaCR = 1.45 ± 0.6 eV), which showed great consistency.

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Thermooxidative Aging Studies on Silicone Rubber and Lifetime Prediction

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.777.11 ◽

2013 ◽

Vol 777 ◽

pp. 11-14

Author(s):

You Shan Wang ◽

Sha Sha Jiang ◽

Yu Peng Liu

Keyword(s):

Silicone Rubber ◽

Room Temperature ◽

Elevated Temperatures ◽

Activation Energies ◽

Lifetime Prediction ◽

Arrhenius Behavior ◽

Compression Set ◽

Degradation Processes ◽

Aging Studies ◽

Significant Compression

Silicone rubber have been aged in air while under 25% compression at temperature up to 250°C. These studies examined the compression set of silicone rubber at accelerated (elevated) temperatures and were then used to make predictions about compression set at room temperature. The data obtained could be amenable to timetemperature superposition and Arrhenius treatment. The results suggest the presence of two degradation processes with activation energies of 71.6 kJ mol-1 (for temperatures above 165 °C) and 26.08 kJ mol-1 (for temperatures below 165 °C). Based on the extrapolation of the non-Arrhenius behavior, it was estimated that significant compression set loss would occur after around 67 years at 25 °C.

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Hydraulic Conductivity of Compacted Lime-Softening Sludge Used as Landfill Liners

Water Air & Soil Pollution ◽

10.1007/s11270-019-4281-z ◽

2019 ◽

Vol 230 (12) ◽

Cited By ~ 1

Author(s):

Agnieszka Dąbska

Keyword(s):

Hydraulic Conductivity ◽

Moisture Content ◽

Tap Water ◽

Distilled Water ◽

Landfill Liners ◽

Water Permeation ◽

Lime Softening ◽

Approximate Polynomial ◽

Hazardous Waste Landfills

AbstractThe research goal was to investigate the hydraulic conductivity of compacted lime-softening sludge as a material to be applied to landfill liners. In doing so, the effect of compaction and moulding moisture content on the sludge hydraulic conductivity was assessed. An approximate polynomial k10mean at hydraulic gradients ≥30 for degree of compaction (0.95–1.05) and moulding moisture content (28%–36%) was determined. The results of short-term tap water permeation tests revealed that all hydraulic conductivity values were less than 2.5•10–8 m/s. A lowest hydraulic conductivity of 6.5•10–9 m/s, as well as a corresponding moisture content of 31% were then established. The long-term hydraulic conductivity was measured with tap water, distilled water, NaOH and HCl solutions and municipal waste leachate. The factors of permeating liquids and permeation time significantly affected the initial hydraulic conductivity. The long-term hydraulic conductivity increased for NaOH and HCl solutions and decreased for tap and distilled water. A significant reduction of hydraulic conductivity was observed for leachate permeation. The investigated material met the requirements for the liner systems of inert landfill sites regardless of pH and the limit value for hazardous and non-hazardous waste landfills.

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Evaluation of Low-Temperature Properties and the Fragility of Asphalt Binders with Non-Arrhenius Viscosity–Temperature Dependence

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198105190100106 ◽

2005 ◽

Vol 1901 (1) ◽

pp. 44-51 ◽

Cited By ~ 5

Author(s):

Huachun Zhai ◽

Delmar Salomon

Keyword(s):

Temperature Dependence ◽

Asphalt Binders ◽

Arrhenius Behavior ◽

Direct Tension ◽

Different Temperatures ◽

Rotational Viscosity ◽

Liquid Fragility ◽

The Difference ◽

Critical Cracking Temperature ◽

Experimental Values

Rotational viscosities of different asphalt binders were determined at temperatures between 80°C and 185°C. Viscosity–temperature dependence of asphalt binders was described with the use of the Vogel–Tammann–Fulcher (VTF) and the William–Landel–Ferry (WLF) equations. The Vogel temperature ( Tv) and the glass transition temperature ( Tg) for different asphalt binders were determined by fitting experimental values of viscosity at different temperatures with these two equations. For asphalt binders, the difference between Tv and Tg was about 40K. Effects of asphaltenes, aging, chemical modification, and polymer content on these temperatures were evaluated. As asphaltene content increased, both temperatures, Tv and Tg, increased. Different polymers showed different effects on these temperatures. The values of Tv and Tg were correlated with the critical cracking temperature ( Tcr) determined through use of a bending beam rheometer and a direct tension tester. The results suggested that the correlations between Tv, Tg, and Tcr could be used to determine Tcr from the rotational viscosity results tested at high temperature. With simple rotational measurements, a quick estimation of Tcr of asphalt binders could be obtained. Liquid fragility theory was also used to study Tg of asphalt binders. Parameters determined with the VTF and WLF equations indicated that asphalt binders behaved as fragile liquids because of their non-Arrhenius behavior in the temperature range studied.

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Solubility and the periodic table of elements

Pure and Applied Chemistry ◽

10.1515/pac-2014-0935 ◽

2015 ◽

Vol 87 (5) ◽

pp. 477-485 ◽

Cited By ~ 2

Author(s):

Cezary Gumiński

Keyword(s):

Rare Earth ◽

Rare Earth Metal ◽

Alkali Metals ◽

Salt Water ◽

Earth Metal ◽

Solubility Data ◽

Side Reactions ◽

Data Series ◽

Water Type ◽

Boiling Points

AbstractInteresting general tendencies of changes of solubilities of elements and groups of compounds may be observed when the corresponding solubility data are arrayed according to the increasing atomic number of the elements. Such trends are exemplified with the data of various systems (metallic and salt-water type) evaluated in several volumes of the IUPAC-NIST Solubility Data Series. The solubilities of elements in mercury as well as in liquid alkali metals, when ordered according their atomic numbers, change roughly in a corresponding way as the temperatures and energies of melting or boiling points of the elements. However, majority of transition metals dissolved in alkali metals are subject to some side reactions with nonmetallic impurities that may drastically elevate their concentration levels. The solubilities of intermetallic compounds in mercury depend primarily on the energies of formation of these intermetallics in the binary alloys and then on the dissolution energies of the component metals in mercury. It has been observed that the experimental solubilities of metal halates in water show quite well defined periodical changes. The arrayed solubility data of rare earth metal fluorides and chlorides in water display quite smooth changes with the increasing atomic numbers if the solutes are isomorphic. Some exceptions from the smooth changes for rare earth metal bromides and iodides are explained. These general observations are useful in evaluating and predicting solubilities in experimentally unknown systems.

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