scholarly journals Flexible Textile Strain Sensor Based on Copper-Coated Lyocell Type Cellulose Fabric

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 784 ◽  
Author(s):  
Waleri Root ◽  
Tom Wright ◽  
Barnaby Caven ◽  
Thomas Bechtold ◽  
Tung Pham
Keyword(s):  
Deposition Process ◽  
Tensile Tests ◽  
Reaction Rates ◽  
Copper Deposition ◽  
Copper Sulfate Pentahydrate ◽  
Copper Coatings ◽  
Diffusion Controlled ◽  
Potassium Hydrogen ◽  
Fabric Deformation ◽  
High Concentrations

Integration of sensors in textile garments requires the development of flexible conductive structures. In this work, cellulose-based woven lyocell fabrics were coated with copper during an electroless step, produced at 0.0284 M copper sulfate pentahydrate, 0.079 M potassium hydrogen L-tartrate, and 0.94 M formaldehyde concentrations. High concentrations led to high homogeneous copper reaction rates and the heterogeneous copper deposition process was diffusion controlled. Thus, the rate of copper deposition did not increase on the cellulose surface. Conductivity of copper coatings was investigated by the resistance with a four probe technique during fabric deformation. In cyclic tensile tests, the resistance of coated fabric (19 × 1.5 cm2) decreased from 13.2–3.7 Ω at 2.2% elongation. In flex tests, the resistance increased from 5.2–6.6 Ω after 5000 bending cycles. After repeated wetting and drying cycles, the resistance increased by 2.6 × 105. The resistance raised from 11–23 Ω/square with increasing relative humidity from 20–80%, which is likely due to hygroscopic expansion of fibers. This work improves the understanding of conductive copper coating on textiles and shows their applicability in flexible strain sensors.

scholarly journals Viscoadaptation controls intracellular reaction rates in response to heat and energy availability

2019 ◽  
Author(s):  
Laura Persson ◽  
Vardhaan S. Ambati ◽  
Onn Brandman
Keyword(s):  
Cellular Response ◽  
Reaction Rates ◽  
Acute Response ◽  
Cellular Environment ◽  
Diffusion Controlled ◽  
Intracellular Diffusion ◽  
Response To Temperature ◽  
And Diffusion ◽  
Tunable Property ◽  
Multiple Conditions

Summary/AbstractCells must precisely orchestrate thousands of reactions in both time and space. Yet reaction kinetics are highly dependent on uncontrollable environmental conditions such as temperature. Here, we report a novel mechanism by which budding yeast influence reaction rates through adjustment of intracellular viscosity. This “viscoadaptation” is achieved by production of two carbohydrates, trehalose and glycogen, which combine to create a more viscous cellular environment in which biomolecules retain solubility. We demonstrate that viscoadaptation functions as both an acute response to temperature increase as well as a homeostatic mechanism, allowing cells grown at temperatures spanning from 22°C to 40°C to maintain equivalent rates of intracellular diffusion and diffusion-controlled chemical reactions. Multiple conditions that lower ATP trigger viscoadaptation, suggesting that viscoadaptation may be a general cellular response to low energy. Viscoadaptation reveals viscosity to be a tunable property of cells through which they can regulate diffusion-controlled processes dynamically in response to a changing environment.

scholarly journals Extrapolation and interpolation by time-scaling in systems with diffusion-controlled kinetics and first-order reaction rates.

1989 ◽  
Vol 37 (1) ◽  
pp. 47-60
Author(s):  
S.E.A.T.M. van der Zee ◽  
W.H. van Riemsdijk ◽  
J.J.M. van Grinsven
Keyword(s):  
Reaction Rates ◽  
Order Reaction ◽  
Management Tool ◽  
First Order ◽  
Physicochemical Processes ◽  
Time Scaling ◽  
Diffusion Controlled ◽  
Scaling Procedure ◽  
Exposure Variable ◽  
Scaling Rule

The interpolation or extrapolation in time of physicochemical processes from experimental data is often difficult. A theoretically derived time-scaling procedure using an exposure variable of the concentration integrated in time, with at most one adjustable parameter was applied successfully to three systems taken from metallurgical, agricultural and environmental engineering. This scaling rule is potentially useful as a research or management tool for systems that are too complex for mechanistic modelling. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Knitting Technologies And Tensile Properties Of A Novel Curved Flat-Knitted Three-Dimensional Spacer Fabrics

2015 ◽  
Vol 15 (3) ◽  
pp. 191-197 ◽  
Author(s):  
Xiaoying Li ◽  
Gaoming Jiang ◽  
Xiaolin Nie ◽  
Pibo Ma ◽  
Zhe Gao
Keyword(s):  
Tensile Stress ◽  
Tensile Properties ◽  
Dimensional Stability ◽  
Three Dimensional ◽  
Tensile Tests ◽  
Weft Direction ◽  
Aramid Fibres ◽  
Spacer Fabric ◽  
Fabric Deformation ◽  
Spacer Fabrics

AbstractThis paper introduces a knitting technique for making innovative curved three-dimensional (3D) spacer fabrics by the computer flat-knitting machine. During manufacturing, a number of reinforcement yarns made of aramid fibres are inserted into 3D spacer fabrics along the weft direction to enhance the fabric tensile properties. Curved, flat-knitted 3D spacer fabrics with different angles (in the warp direction) were also developed. Tensile tests were carried out in the weft and warp directions for the two spacer fabrics (with and without reinforcement yarns), and their stress–strain curves were compared. The results showed that the reinforcement yarns can reduce the fabric deformation and improve tensile stress and dimensional stability of 3D spacer fabrics. This research can help the further study of 3D spacer fabric when applied to composites.

Effect of organic compounds on nitrite accumulation during the nitrification process for coking wastewater

2010 ◽  
Vol 62 (9) ◽  
pp. 2096-2105 ◽  
Author(s):  
H. B. Li ◽  
H. B. Cao ◽  
Y. P. Li ◽  
Y. Zhang ◽  
H. R. Liu
Keyword(s):  
Organic Compounds ◽  
Ammonia Oxidation ◽  
Industrial Effluents ◽  
Reaction Rates ◽  
Inhibitory Effect ◽  
Nitrite Accumulation ◽  
Coking Wastewater ◽  
Batch Bioreactor ◽  
The Difference ◽  
High Concentrations

Coking wastewater is one of the most toxic industrial effluents since it contains high concentrations of ammonia and toxic organic compounds. Nitrification might be upset by the inhibitory effect of organic compounds during the biological treatment of the wastewater. In this study, shortcut nitrification was obtained in a sequencing batch bioreactor (SBR) and the inhibitory effect of organic compounds on the nitrification was examined when temperature was 30±1°C, pH was 7.0–8.5, and dissolved oxygen concentration was 2.0–3.0 mg L−1. The inhibitory effect of organic compounds was presumed to be one of the main factors to obtain satisfactory nitrite accumulation. The effect of organic compounds on nitrification was examined in the SBR with initial inhibitor concentrations ranging from 0 to 80 mg L−1, including phenol, pyrocatechol, resorcin, benzene, quinoline, pyridine and indole. The inhibitory effect became stronger with the increase in the concentration, and it was presumed to take place through a direct mechanism resulting from biological toxicity of the inhibitor itself. Furthermore, the inhibitory effect on ammonia oxidation was slighter than that on nitrite oxidation, and the nitrite accumulation ratio during the nitrification was determined by the difference between the reaction rates of above two processes.

Activated carbon based biological fluidized beds for contaminated water and wastewater treatment: a state-of-the-art review

1994 ◽  
Vol 29 (10-11) ◽  
pp. 309-317 ◽  
Author(s):  
P. M. Sutton ◽  
P. N. Mishra
Keyword(s):  
Activated Carbon ◽  
North America ◽  
Historical Review ◽  
Reaction Rates ◽  
Commercial Application ◽  
Water And Wastewater Treatment ◽  
Active Biomass ◽  
Commercial Media ◽  
Biological Reaction ◽  
High Concentrations

The ability of the biological fluidized bed (BFB) process configuration to intensify biological reaction rates through accumulation of high concentrations of active biomass has brought attention to the technology for the past twenty years. Over 80 commercial, media based BFB reactors have been installed in North America and Europe. Currently there is much interest in systems in which granular activated carbon (GAC) is used as the fluidizing media for treatment of contaminated waters and wastewaters. This paper provides a historical review of the development of the technology together with information on design and commercial application of the technology in North America.

X-ray photoelectron spectroscopy of uv laser irradiated sapphire and alumina

1994 ◽  
Vol 9 (9) ◽  
pp. 2251-2257 ◽  
Author(s):  
A.J. Pedraza ◽  
J.W. Park ◽  
H.M. Meyer ◽  
D.N. Braski
Keyword(s):  
Laser Irradiation ◽  
Valence Band ◽  
Photoelectron Spectroscopy ◽  
Deposition Process ◽  
Copper Deposition ◽  
Excess Oxygen ◽  
Ceramic Surface ◽  
Metallic Aluminum ◽  
X Ray ◽  
Reducing Atmosphere

X-ray photoelectron spectroscopy (XPS) was performed in as-received, thermally annealed, and laser-irradiated sapphire and alumina specimens in order to study the effects of the different treatments on surface chemistry and properties. Laser irradiations with a 308 nm wavelength laser were performed in air and in a reducing atmosphere consisting of a mixture of Ar and 4% of hydrogen. The atomic percentages of carbon, aluminum, and oxygen were measured in all the specimens. Particular attention was paid to the percentages of oxygen in the oxide and in a hydroxyl state. The XPS analyses clearly established that a very thin film of metallic aluminum is formed on the surface of both alumina and sapphire substrates when they are irradiated under a reducing atmosphere. However, the film is discontinuous because it is electrically insulating. Substrates irradiated in air have metallic aluminum only for fluences below 0.4 J/cm2. The valence band photoemission spectra of as-received, annealed, and laser-irradiated specimens were measured. In irradiated specimens, the width of the valence band spectra was found to decrease by ∼10%. One possible cause of this decrease is the generation of point defects during laser irradiation. Electroless copper deposition occurs on sapphire and alumina substrates if their surface has been activated by laser irradiation. The time required for copper deposition was monitored by measuring the electrical resistivity in the irradiated area while the substrates were immersed in an electroless bath. The kinetics of deposition on laser-activated substrates and the XPS results show that the presence of metallic aluminum accelerates the deposition process. However, the presence of aluminum is not the sole reason for laser activation in alumina. Very strong metal-ceramic bonding is produced after thermal annealing of samples having preirradiated substrates. This result is explained in terms of the excess oxygen that is present at the ceramic surface after irradiation.

THE METHOD OF INTER-PARTICLE DISTRIBUTION FUNCTIONS FOR DIFFUSION-REACTION SYSTEMS IN ONE DIMENSION

1995 ◽  
Vol 09 (15) ◽  
pp. 895-919 ◽  
Author(s):  
DANIEL BEN-AVRAHAM
Keyword(s):  
Contact Process ◽  
Reaction Rates ◽  
Distribution Functions ◽  
Diffusion Reaction ◽  
Nonequilibrium Dynamics ◽  
One Dimension ◽  
Many Body ◽  
Dynamical Phase ◽  
Diffusion Limited ◽  
Diffusion Controlled

Diffusions limited reactions in confined geometries exhibit all aspects of nonequilibrium dynamics, such as anomalous kinetics, self-organization and dynamical phase transitions, and have therefore been the subject of extensive research in recent years. In this paper we review the method of interparticle distribution functions (IPDF) which was originally introduced for deriving the exact kinetics of the diffusion-limited coalescence process, A+A→A, in one dimension. We explain the IPDF method and review variants of the coalescence model which can be solved exactly through this technique. We then consider strategies for approximations based on the IPDF method and review applications to coalescence with finite reaction rates (away from the strictly diffusion-controlled regime), many-body reactions (nA→mA), and the contact process. We conclude with a discussion of open, interesting problems and possible ways to their solution.

Diffusion-controlled reaction rates

1949 ◽  
Vol 4 (4) ◽  
pp. 425-437 ◽  
Author(s):  
Frank C Collins ◽  
George E Kimball
Keyword(s):  
Reaction Rates ◽  
Diffusion Controlled ◽  
Diffusion Controlled Reaction
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