THE USE OF FLY ASH ALUMINOSILICATE MICROSPHERES IN THE LIME DRY MIXES FOR FINISHING AERATED CONCRETE

2017 ◽  
Vol 2 (3) ◽  
pp. 6-8 ◽  
Author(s):  
Логанина ◽  
Valentina Loganina ◽  
Фролов ◽  
Mikhail Frolov
Keyword(s):  
Thermal Conductivity ◽  
Water Vapor ◽  
Fly Ash ◽  
Water Vapor Permeability ◽  
High Water ◽  
Vapor Permeability ◽  
Low Thermal Conductivity ◽  
Aerated Concrete ◽  
Sufficient Strength

The application of ash microspheres in lime dry construction mixtures, designed for finishing aerated. It is shown that on the basis of dry ash mixtures with microspheres characterized by coating a sufficient strength, low thermal conductivity, high water vapor permeability, resistance to the action of the slanting rain.

scholarly journals WATER VAPOR PERMEABILITY OF POROUS MEDIA

1959 ◽  
Vol 37 (4) ◽  
pp. 413-416 ◽  
Author(s):  
William Woodside
Keyword(s):  
Thermal Conductivity ◽  
Porous Media ◽  
Water Vapor ◽  
Permeability Coefficient ◽  
Lightweight Concrete ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Empirical Relationships ◽  
Glass Spheres ◽  
Cellular Concrete

Following the analogy between the laws of heat conduction and vapor diffusion, two theoretical expressions for the thermal conductivity of a composite medium are applied to the water vapor permeability coefficient of certain porous media. It is shown that both expressions reduce to a form very similar to the empirical relationships found by Penman and Edenholm for soils, glass spheres, charcoal, and cellular concrete. The calculation of the variation of water vapor permeability with density for a cellular lightweight concrete is illustrated.

scholarly journals Influence of Hydration State on Permeation Testing and Vapor Transport Properties of Protective Clothing Layers

2009 ◽  
Vol 4 (4) ◽  
pp. 155892500900400 ◽  
Author(s):  
Phillip W. Gibson ◽  
Heidi L. Schreuder-Gibson
Keyword(s):  
Water Vapor ◽  
Protective Clothing ◽  
Chemical Warfare Agents ◽  
Water Vapor Permeability ◽  
High Water ◽  
Chemical Warfare ◽  
Vapor Permeability ◽  
Liquid Form ◽  
Vapor Flux ◽  
Warfare Agents

Protective clothing systems composed of permselective polymer film laminates are an alternative to standard air-permeable garments based on activated carbon. These polymer layers are designed with high water vapor permeation rates and low permeation of chemical warfare agents. Polymer films that have a significant water vapor flux usually also have an affinity for water, and will hydrate and swell significantly at high humidity levels. The polymer film's increase in water content has the potential to affect the transport rate of chemical warfare agents in vapor and liquid form, and usually also has a large effect on the intrinsic water vapor permeability of the membrane.

scholarly journals Polybenzimidazole-based mixed membranes with exceptionally high water vapor permeability and selectivity

2017 ◽  
Vol 5 (41) ◽  
pp. 21807-21819 ◽  
Author(s):  
F. H. Akhtar ◽  
M. Kumar ◽  
L. F. Villalobos ◽  
H. Vovusha ◽  
R. Shevate ◽  
...  
Keyword(s):  
Water Vapor ◽  
Gas Separation ◽  
Water Vapor Permeability ◽  
High Water ◽  
Mixed Matrix Membranes ◽  
Vapor Permeability ◽  
Mixed Matrix ◽  
Matrix Membranes

Mixed matrix membranes containing polybenzimidazole and titania-based fillers with different morphologies are fabricated and tested for efficient water vapor/gas separation applications.

The effects of the combined process of enzymatic bleach clean-up, enzymatic defibrillation and dyeing on the comfort and physical properties of Tencel/cotton knitted fabrics

2019 ◽  
Vol 90 (9-10) ◽  
pp. 1118-1129
Author(s):  
Sibel Şardağ ◽  
Tuba Toprak ◽  
Pervin Aniş
Keyword(s):  
Thermal Conductivity ◽  
Water Vapor ◽  
Physical Properties ◽  
Water Vapor Permeability ◽  
Lower Surface ◽  
Air Permeability ◽  
Vapor Permeability ◽  
Knitted Fabrics ◽  
Single Bath ◽  
Loss Of Mass

This study aimed to investigate the comfort and physical properties of raw and finished knitted fabrics made of yarns with different Tencel/cotton blend ratios. For this purpose, Ne 20 yarns were produced with the same twist coefficient on the same production line. Fabric samples were produced on the same knitting machine. The raw fabrics were subjected to two different combined enzymatic pre-treatments and dyeing processes. In the first process, enzymatic defibrillation and dyeing were carried out in the same bath. In the second, enzymatic bleach clean-up, defibrillation and dyeing were conducted in the same bath. The comfort and physical properties of all the raw and finished fabric samples were measured according to the relevant standards. The results were assessed statistically. The results of this study showed that with increased percentage of Tencel in the blend, the water vapor and air permeability, fabric roughness, pilling, thermal absorption and loss of mass values of the fabrics increased, whereas thermal conductivity values decreased. It was observed that the fabrics which were subjected to enzymatic defibrillation and dyeing processes in a single bath gave lower surface roughness and abrasion values but higher air permeability values; while those subjected to enzymatic bleach clean-up, defibrillation and dyeing in a single bath gave higher thermal conductivity and thermal absorptivity values. Comparison of the two processes showed that there were no significant differences in the pilling and the water vapor permeability values obtained from both processes.

scholarly journals Synthesis of Silphenylene-Containing Siloxane Resins Exhibiting Strong Hydrophobicity and High Water Vapor Barriers

Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 481
Author(s):  
Chen ◽  
Yi ◽  
Wu ◽  
Tan ◽  
Xu ◽  
...  
Keyword(s):  
Contact Angle ◽  
Water Vapor ◽  
Water Contact Angle ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
High Water ◽  
Vapor Permeability ◽  
One Pot ◽  
Water Contact ◽  
Thermal Stabilities

The novel phenylenedisilane, 1,4-bis(dimethoxyphenylsilyl)benzene (BDMPD), was successfully synthesized via the reaction between trimethoxyphenylsilane (TMPS) and a Grignard reagent originating from 1,4-dibromobenzene. In comparison to common Grignard reactions, this process was a facile one-pot method. 1H NMR spectroscopy, FT-IR measurements, and elemental analysis confirmed the predicted structure of BDMPD. In addition, vinyl-terminated polysiloxanes containing silphenylene units (VPSSP), which were hydrolytically copolymerized from BDMPD, TMPS, and divinyltetramethyldisiloxane, exhibited excellent thermal stabilities (T10%: 502 °C, Rw%: 76.86 beyond 700 °C) and suitable refractive indices (1.542). Furthermore, water contact angle and water vapor permeability tests confirmed that the fully cured siloxane resins containing VPSSP-based silphenylene units exhibited strong hydrophobicity (water contact angle: 119°) and superior water vapor barrier properties, thereby indicating their potential to serve as strong waterproof coatings for moisture-proof applications or as adhesives for use in immersed equipment.

Novel method on thermal resistance prediction and thermo-physiological comfort of socks in a wet state

2020 ◽  
Vol 90 (17-18) ◽  
pp. 1987-2006 ◽  
Author(s):  
Tariq Mansoor ◽  
Lubos Hes ◽  
Vladimir Bajzik ◽  
Muhammad Tayyab Noman
Keyword(s):  
Thermal Conductivity ◽  
Water Vapor ◽  
Thermal Resistance ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Relative Water ◽  
Novel Method ◽  
Resistance Prediction ◽  
Filling Coefficient ◽  
Thermal Absorptivity

The present study proposes a novel method to measure the thermal resistance and comfort properties of various sock samples under wet conditions. Theoretically, comfort properties are responsible for transporting moisture by our body with different rates. Therefore, plain socks with different fiber composition were wetted to a saturated level and after getting the required moisture content, the sock samples were characterized by Alambeta (for thermal resistance and thermal absorptivity) and Permetest instruments for relative water vapor permeability in the wet state. In addition, various skin models were utilized to make a comparison of thermal resistance in the dry state. Two different models were modified for analyzing the thermal resistance under wet conditions. According to the models used, the prediction of thermal resistance is a combined effect of the filling coefficient and thermal conductivity of wet polymers instead of dry polymers. With these modifications, the used models predicted the thermal resistance at different moisture levels with a significant correlation ( R2) value, that is, 0.84–0.97.

Characteristics of Laminates for Car Seats

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Eva Batič ◽  
Dunja Šajn Gorjanc
Keyword(s):  
Thermal Conductivity ◽  
Water Vapor ◽  
Abrasion Resistance ◽  
Water Vapor Permeability ◽  
Areal Density ◽  
Air Permeability ◽  
Vapor Permeability ◽  
Car Seats ◽  
Basic Characteristics ◽  
Nonwoven Textiles

AbstractIn the presented research, 11 different laminates were compared, 8 of them were two-layered 3 of them were three-layered laminates. The laminates that were analyzed vary by the type of face-side textile material (knitted and nonwoven textiles), density and thickness of the foam, and specific properties (higher air permeability and low-emission foam). Depending on the different types of laminates, different laminating processes are used: hot-melt, flame, and powder laminations. The purpose of the presented research is to analyze the basic characteristics of the different laminate structures. Properties that are important for these types of laminates are the number of layers, areal density, thickness, resistance to rubbing, fire resistance, water vapor permeability, air permeability, breaking force and extension, thermal conductivity, and stratification. We found that the properties of laminates were not affected by the density and thickness of the foam. Nonwovens and other laminate components do not perform because they have lower abrasion resistance and lower tensile strength than knitted fabrics as the face layer. Knit laminates have good abrasion resistance, high air permeability, and water vapor permeability. Both are self-extinguishing to the first or second mark. Three-layered laminates have lower thermal conductivity and air permeability than two-layered laminates.

scholarly journals Wearable porous PDMS layer of high moisture permeability for skin trouble reduction

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sunghyun Yoon ◽  
Minho Seok ◽  
Mookyum Kim ◽  
Young-Ho Cho
Keyword(s):  
Water Vapor ◽  
Pore Size ◽  
Daily Life ◽  
Transmission Rate ◽  
Water Vapor Permeability ◽  
High Water ◽  
Vapor Permeability ◽  
Pdms Layer ◽  
Water Vapor Transmission Rate ◽  
Water Vapor Transmission

AbstractThe present research proposes the present porous polydimethylsiloxane (PDMS) layer for the skin trouble reduced daily life skin attachable devices. The present research proposes the new pores forming method in the PDMS by crystallization and dissolution of the citric acid in the PDMS for fabricating high uniform and small size pores. The present porous PDMS layer (i) decreases the pore size 93.2%p and increases the pore size uniformity 425%p compared to the conventional porous PDMS layer of mixing sugars and PDMS; (ii) is able to be fabricated in the thickness of 21–101 µm by spin-coating; (iii) has the 2.2 times higher water vapor transmission rate (947 ± 10.8 g/day•m2) compared to the human skin water vapor transmission rate. The present porous PDMS layer reduces the skin trouble effectively by having the high water vapor permeability, therefore is applicable to the human daily-life skin attachable devices.

Sign in / Sign up

Export Citation Format

Share Document