An effect of fabrics thickness and structure on moisture management properties of 3D spacer fabrics

2019 ◽  
Vol 31 (6) ◽  
pp. 777-789
Author(s):  
Palani Rajan T. ◽  
Prakash C. ◽  
Ramakrishnan G.

Purpose Polyester multifilament is used to produce the face and back layer of warp knitted spacer fabric (WKSF) and these two layers are connected by polyester monofilament as a middle layer. This fabric has unique and extraordinary characteristics, and different possibilities of fabric structure and the middle layer thickness are tried to find out the moisture management properties. The paper aims to discuss these issues. Design/methodology/approach This study investigates the influence of fabric thickness and structure on moisture management properties. Findings Polyester monofilament quickly up takes the water molecule from the water reservoir and transfers it by capillary action. The gravitational force and the availability space between the two outer surface layers restrict the movement of water molecules, although the pressure develops to push the molecules from the water reservoir. As a result, all the spacer fabric samples attain the equilibrium state very quickly. WKSF and the hexagonal net structure prove to be better in vertical wicking. Originality/value The liquid movement is quick in the front side of the spacer fabric, and the rate of wicking is higher in open structure than in the closed structure. It confirms that the hexagonal net structure produces high pore size on fabric and it reaches maximum wicking values. Fabric thickness does not have much influence on the vertical wicking properties of all fabric samples, and the rate of liquid movement produces a similar trend. In in-plane wicking, the polyester monofilament in the middle layer of spacer fabric plays a major role rather than the outer surface layers of fabric.

2015 ◽  
Vol 62 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Reza Tamasgavabari ◽  
Kurosh Jafarzadeh ◽  
Masumeh Madanipoor ◽  
Hassan Badri

Purpose – The purpose of this paper was the investigation of corrosion behaviour of Ni-6Al-10Cu-11Fe-15Cr alloy, as a candidate material for inert anodes in aluminium electrolysis industries. Design/methodology/approach – The samples were prepared by casting, and then were oxidized at 1,000°C for 30, 70 and 100 hours, respectively. To determine corrosion resistant of the samples, they were exposed to molten cryolite at 930°C for 70 hours. Then the surface layers were studied. Findings – Results showed that by extension of corrosion time, thickness of oxide layers increases. In addition, it was found that Al2O3 and Cr2O3 are the major oxide compounds that appear on the surface of the sample. Originality/value – In this paper, the Ni-6Al-10Cu-11Fe-15Cr nickel base alloy has been selected to study its corrosion behaviour in molten cryolite as a candidate for inert anodes. It was found out that by addition Al and Cr into the alloy composition, due to formation of Al2O3 and Cr2O3 following oxidation, the substrate was protected from corrosion attacks.


2017 ◽  
Vol 48 (4) ◽  
pp. 738-760 ◽  
Author(s):  
T Suganthi ◽  
P Senthilkumar

Thermo-physiological comfort of the fabric is attained through the ability of managing heat and transmission of sensible and insensible perspiration. An investigation on influence of tri-layer knitted structure on thermal comfort characteristics of layered knitted fabrics was carried out. Three tri-layer knitted structures were developed in which inner layer was made up of micro-fibre polyester and outer layer was made up of modal yarn. The yarn used in the middle layer was changed to either micro-fibre polyester or polyester or acrylic yarn. The thermal comfort characteristics such as thermal conductivity, air permeability, water vapour permeability, wicking, moisture absorbency, drying rate and moisture management properties have been analysed. Wear trial was conducted for shuttle badminton players and they were ranked using thermal environment subjective judgement scale. Tri-layer knitted structure with micro-fibre polyester in the inner and middle layer and modal in the outer layer showed better thermal comfort characteristics both by objective evaluation and wear trial method compared to polyester or acrylic in the middle layer and is preferable for shuttle badminton sportswear.


2016 ◽  
Vol 88 (1) ◽  
pp. 59-68 ◽  
Author(s):  
Chaoyu Chen ◽  
Zhaoqun Du ◽  
Weidong Yu ◽  
Tilak Dias

The main content dealt with in the paper is to present a kind of weft-knitted spacer fabric with high porosity. It is a kind of three-dimensional textile fabric with a sandwich structure that consists of a middle layer of multifilament and two outer layers of plain-knitted fabric. Compared with traditional warp-knitted spacer fabric as cushion mats, weft-knitted spacer fabric is well used as apparel for good softness, thermal/moisture comfort, and air permeability. Therefore, three structures were designed and nine samples were prepared by choosing plain-knitted fabric as the outer layers and selecting soft and thin multifilament as a middle layer. Experimental results show that this kind of weft-knitted spacer fabrics has high porosity, greater than 86%, and also demonstrate that the weft-knitted spacer fabric is suitable for comfortable apparel based on experimental results of air permeability, compression properties, stiffness, and thermal insulation properties.


2020 ◽  
Vol 9 (47) ◽  
Author(s):  
Ju-Yong Jeong ◽  
Mi-Ra Yun ◽  
Seung-Eun Oh ◽  
Seon-Min Hwang ◽  
Chan-Won Hwang ◽  
...  

ABSTRACT The complete genome and plasmid sequences of Raphidiopsis curvispora strain GIHE-G1, a coiled filamentous heterocyst-forming cyanobacterium isolated from a drinking water reservoir in South Korea, are reported here. The genome information is expected to improve understanding of this species.


2019 ◽  
Vol 880 ◽  
pp. 209-238 ◽  
Author(s):  
Xiangming Yu ◽  
Kelli Hendrickson ◽  
Bryce K. Campbell ◽  
Dick K. P. Yue

We investigate two-phase free-surface turbulence (FST) associated with an underlying shear flow under the condition of strong turbulence (SFST) characterized by large Froude ($Fr$) and Weber ($We$) numbers. We perform direct numerical simulations of three-dimensional viscous flows with air and water phases. In contrast to weak FST (WFST) with small free-surface distortions and anisotropic underlying turbulence with distinct inner/outer surface layers, we find SFST to be characterized by large surface deformation and breaking accompanied by substantial air entrainment. The interface inner/outer surface layers disappear under SFST, resulting in nearly isotropic turbulence with ${\sim}k^{-5/3}$ scaling of turbulence kinetic energy near the interface (where $k$ is wavenumber). The SFST air entrainment is observed to occur over a range of scales following a power law of slope $-10/3$. We derive this using a simple energy argument. The bubble size spectrum in the volume follows this power law (and slope) initially, but deviates from this in time due to a combination of ongoing broad-scale entrainment and bubble fragmentation by turbulence. For varying $Fr$ and $We$, we find that air entrainment is suppressed below critical values $Fr_{cr}$ and $We_{cr}$. When $Fr^{2}>Fr_{cr}^{2}$ and $We>We_{cr}$, the entrainment rate scales as $Fr^{2}$ when gravity dominates surface tension in the bubble formation process, while the entrainment rate scales linearly with $We$ when surface tension dominates.


Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2360 ◽  
Author(s):  
Ali Shalbafan ◽  
Amin Nadali ◽  
Heiko Thoemen

Geopolymers show great potential for use as binders in developing and manufacturing multifunctional wood products. The objective of this study was to improve the bonding quality of a geopolymer binder, with wood veneers, using different manufacturing parameters. To this end, we produced five layered plywood panels treated with various lay-up times (1, 5, 10, 15 min), panel compressibility values during hot pressing (5%, 10%, 15%, and 30% compression), veneer roughness values (low, medium, and high roughness), press temperatures (120, 140, and 160 °C), and veneer layouts via changing the middle layer position of plywood relative to the surface layers. The results show that the shear strength and thickness swelling were negatively influenced by increasing the lay-up time of resinated veneers and panel compressibility. Increasing the veneer roughness significantly increased the panels’ properties. Furthermore, the panels produced with a pressing temperature of 140 °C showed the best performances. The veneer layouts also significantly changed the physical and mechanical properties of the plywood panels. Generally speaking, the results obtained in this study show that improving the bonding quality of geopolymer binders with wood can be done through the manipulation of plywood manufacturing parameters.


2019 ◽  
Vol 30 (5) ◽  
pp. 2237-2253 ◽  
Author(s):  
Karol Kaczmarski

Purpose The purpose of this paper is to develop a numerical model of a steam pipeline connecting a boiler with a turbine, with an insulated outer surface. The temperature distribution inside the pipeline wall was compared when was perfectly insulated and when used real insulation on the outside surface. Design/methodology/approach The transient temperature, pressure and velocity of steam in the pipeline were determined using a proposed numerical model with distributed parameters. To calculate the transient temperature of the steam and pipeline wall the finite volume method was used. The energy conservation equations were written for all control area around all the nodes. The heat balance equations are a system of first-order ordinary differential equations with respect to time. The Runge–Kutta method of the fourth-order was used to solve the system of ordinary differential equations of the first-order. Findings The temperature distribution in the pipeline wall and the temperature distribution in wall insulation were presented. Also, the temperature of the steam and pipeline wall as a function of insulation thickness was calculated. Based on the results obtained by the proposed numerical model, thermal stresses at the inner and outer surface of the component were determined. To assess the accuracy of the proposed model, the results were compared to the analytical solution for the steady state. Originality/value The paper presents the results obtained from calculations using a numerical model of the steam pipeline with the actual insulation on the outer surface.


2016 ◽  
Vol 33 (3) ◽  
pp. 136-140 ◽  
Author(s):  
Tibor Rovensky ◽  
Alena Pietrikova ◽  
Igor Vehec ◽  
Martin Kmec

Purpose The purpose of this paper is to create multilayer substrate (composite) from various low temperature co-fired ceramic (LTCC) substrates by their mutual combinations and to analyse influence of these multilayer substrates on dielectric properties in GHz frequency range. Design/methodology/approach GreenTape 951, GreenTape 9K7 and Murata LFC were used to create compound multilayer substrates that include three layers: middle layer is from Murata LFC, and both upper and bottom layers are either from GreenTape 951 or GreenTape 9K7. Shrinkage in all x-, y- and z-axes of all substrates including multilayer substrates were analysed, and influence of different shrinkage on dielectric properties was examined by microstrip ring resonators applied on all mentioned of substrates. Findings The middle layer of Murata LFC has significant influence on shrinkage value of composites which has a good repeatability and minimalizes problems with design of multilayer LTCC devices. Impact of middle layer from Murata LFC on dielectric constant is not significant, but on the other hand Q factor (loss tangent) of these composites is increased according to inhomogeneity between single LTCC layers, especially at frequency around 6 GHz. Originality/value The novelty of this work lies in creating multilayers systems from different types of LTCC substrates to find combination with the most suitable physical and dielectric properties for various purposes in GHz range applications.


2014 ◽  
Vol 64 (Pt_4) ◽  
pp. 1186-1193 ◽  
Author(s):  
René Kaden ◽  
Cathrin Spröer ◽  
Daniel Beyer ◽  
Peter Krolla-Sidenstein

A Gram-stain-negative, oxidase and phosphatase-positive and catalase-negative, short rod-shaped bacterium was isolated from sediment of a drinking water reservoir in Germany. Based on 16S rRNA gene sequence and phenotypic properties, the bacterium belongs to the genus Rhodoferax within the family Comamonadaceae . The new taxon differed from related species mainly with respect to its fatty acid composition, low growth temperature, lack of pigments in young cultures and ability to utilize glycerol and d-mannose but not urea. The major fatty acids were C16 : 1ω7c and/or iso-C15 : 0 2-OH, C16 : 0, and C18 : 1ω7c. The only ubiquinone detected was ubiquinone Q-8. The DNA G+C content was 60.3–61 mol%. Because of the phenotypic and genotypic differences from the most closely related taxa, the new strain represents a novel species for which the name Rhodoferax saidenbachensis sp. nov. is proposed. The type strain is ED16T ( = CCUG 57711T = ATCC BAA-1852T = DSM 22694T). An emended description of the genus Rhodoferax is proposed. Based on the results of this study, strain T118T (Albidiferax ferrireducens) is properly placed in the genus Rhodoferax as Rhodoferax ferrireducens.


1994 ◽  
Vol 80 (2) ◽  
pp. 336-337 ◽  
Author(s):  
Kazuhiko Fujitsu ◽  
Yuusuke Ishiwata ◽  
Gakuji Gondo ◽  
Satoshi Fujii ◽  
Deng Dong Feng

✓ A technique combining wrapping and clipping using a Silastic sheet coated with Dacron mesh is described for treatment of fusiform or broad-based cerebral aneurysms. This sheet is easily tailored to wrapping the aneurysm base while avoiding involvement of the cranial nerves or branching vessels. The sheet is semitransparent so that the caliber of the newly constructed parent artery is easily adjusted during wrap-clipping. After the aneurysm and the parent artery have been circumferentially wrapped with the sheet, aneurysm clips are applied on the sheet so that the base of the aneurysm is clipped between the two leaves of the sheet. This wrap-clipping technique avoids the risks involved in extracting the aneurysm from the parent artery. The Dacron mesh coating the outer surface and sufficient clip closing pressure are both helpful in preventing the clip blades from sliding. Similar previously reported techniques are reviewed and discussed in detail.


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