scholarly journals Study on the Preparation and Properties of Impervious and Breathable Sand Based on Hydrophobic Theory

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5613
Author(s):  
Xiao Li ◽  
Xiong Zhang ◽  
Hao Ren

Land desertification, a severe global ecological and environmental problem, brings challenges to the sustainable utilization of land resources in the world. The purpose of this research is to use hydrophobic theory to prepare impervious and breathable sand, and to solve the problems of sandy soil that seeps easily and makes it difficult for vegetation to survive in desertified areas. The influences of coating material content, first-level and second-level rough structure on the impermeability and air permeability of impervious and breathable sand were studied. The research showed that, with the increase in coating material content, the impervious performance of the sample increased firstly and then decreased, and the air permeability rose continuously. The hydrostatic pressure resistance of the sample can reach an extreme value of 53 mm. The first-level rough structure of micron structure can greatly improve the hydrophobic performance, thus improving the impervious performance. The addition of micron calcium carbonate would improve the hydrostatic pressure resistance height of the sample to 190 mm. The sample would reach a superhydrophobic state in the condition of a first-level rough structure of a nano structure built by nano silica, and the contact angle was up to 152.0°, so that the hydrostatic pressure resistance height can rise to 205 mm. The best performance would be achieved under the condition of relatively less raw material with a second-level rough structure of micro–nano. At this point, the contact angle of the sample reached 152.8° and the hydrostatic pressure resistance height was up to 205 mm. At the same time, the air permeability index of the above four kinds of impervious and breathable sand met all planting requirements. The sample prepared can satisfy the demands of different degrees of impermeability and air permeability, and can be widely used in desertification control.

2020 ◽  
Vol 20 (4) ◽  
pp. 372-381
Author(s):  
Suzana Kutnjak-Mravlinčić ◽  
Jadranka Akalović ◽  
Sandra Bischof

AbstractFunctionality and appearance are key aspects of good footwear. Developments in recent science and technology offer a wider scope of innovations, contributing to diversity and higher complexity of the production concept of footwear. Contemporary industrial footwear market offers a practically limitless number of new design and fashion solutions, often of quite similar appearance, but with significant differences in quality level, both regarding manufacture, raw material content, durability, and in some special functional finishes. The materials for footwear manufacture are functionalized for functional protective purposes, such as antimicrobial, waterproofing, fire resistant, wear and tear resistant, and recently for some therapeutical purposes. Novelties in material functionalization for the materials built in the footwear are most often promoted and presented on tags and labels and are used as advertisement issues, while some functionalities have become a logo for some brands.


2021 ◽  
Vol 59 (2) ◽  
Author(s):  
Elizabeta Zandona ◽  
Marijana Blažić ◽  
Anet Režek Jambrak

The dairy industry produces large amounts of whey as a by- product or co-product, which has led to considerable environmental problems due to its high organic matter content. Over the past decades, possibilities of more environmentally and economically efficient whey utilisation have been studied, primarily to convert unwanted end products into a valuable raw material. Sustainable whey management is mostly oriented to biotechnological and food applications for the development of value-added products such as whey powders, whey proteins, functional food and beverages, edible films and coatings, lactic acid and other biochemicals, bioplastic, biofuels and similar valuable bioproducts. This paper provides an overview of the sustainable utilization of whey and its constituents, considering new refining approaches and integrated processes to covert whey, or lactose and whey proteins to high value-added whey-based products.


2014 ◽  
Vol 9 (1) ◽  
pp. 155892501400900 ◽  
Author(s):  
S. Sakthivel ◽  
Anban J.J. Ezhil ◽  
T. Ramachandran

This paper reports an investigative study on the fabrication and measurement of the air permeability, mechanical properties, pore size distribution, and filtration efficiency of different nonwoven fabrics produced from reclaimed fibers by analytically changing the machine variables to manipulate the physical parameters of the nonwoven fabrics. Reclaimed fiber of cotton (60%) and polyester (40%) blend was used, so that the prospect of value addition to an inexpensive source of raw material could be explored. The changes in air permeability were interpreted in terms of fabric density profile and pore size distribution. The filtration parameters of filtration efficiency, dust holding capacity, and pressure drop were also calculated. Additionally, the effects of calendering on pore size and filtration properties were evaluated to discover the opportunity of fine-tuning and the performance of the filters. The outcome in this study reflected an overall development in all filtration characteristics due to the calendering operation.


2019 ◽  
Vol 78 ◽  
pp. 171-178 ◽  
Author(s):  
Elisa Gayán ◽  
Nele Rutten ◽  
Jan Van Impe ◽  
Chris W. Michiels ◽  
Abram Aertsen

2011 ◽  
Vol 311-313 ◽  
pp. 1634-1637 ◽  
Author(s):  
Li Hong Yao ◽  
Xi Ming Wang ◽  
Ben Hua Fei

Permeability coefficient is an important indicator of surface wettability and permeability, which influenced by the surface roughness. In this paper, bamboo and fir veneer as raw material, the contact angle of phenolic resin adhesives in different surface roughness of outer cuticle of bamboo, inner skin of bamboo, tight side of Chinese fir veneer and loose side of Chinese fir veneer were measured, and then use the software Spass non-linear fitting for permeability coefficient, and analysis of variance of the results by SAS software. The results show that permeability coefficient of four different kinds of surface variance analysis models are significantly, permeability coefficient of fir veneer is larger than bamboo surface; permeability coefficient of tight side of fir veneer is larger than loose side; permeability coefficient of inner skin of bamboo is larger than outer cuticle of bamboo. Permeability coefficients decrease first and then increased when mesh sandpaper increasing.


2019 ◽  
Vol 208 ◽  
pp. 393-401 ◽  
Author(s):  
Patricia B. Cusack ◽  
Ronan Courtney ◽  
Mark G. Healy ◽  
Lisa M.T. O’ Donoghue ◽  
Éva Ujaczki

2021 ◽  
Vol 21 (8) ◽  
pp. 4492-4497
Author(s):  
Eun Ae Shin ◽  
Gye Hyeon Kim ◽  
Jeyoung Jung ◽  
Sang Bong Lee ◽  
Chang Kee Lee

Hydrophobic ceramic coatings are used for a variety of applications. Generally, hydrophobic coating surfaces are obtained by reducing the surface energy of the coating material or by forming a highly textured surface. Reducing the surface energy of the coating material requires additional costs and processing and changes the surface properties of the ceramic coating. In this study, we introduce a simple method to improve the hydrophobicity of ceramic coatings by implementing a textured surface without chemical modification of the surface. The ceramic coating solution was first prepared by adding cellulose nanofibers (CNFs) and then applied to a polypropylene (PP) substrate. The surface roughness increased as the amount of added CNFs increased, increasing the water contact angle of the surface. When the amount of CNFs added was corresponding to 10% of the solid content, the surface roughness average of the area was 43.8 μm. This is an increase of approximately 140% from 3.1 μm (the value of the surface roughness of the surface without added CNFs). In addition, the water contact angle of the coating with added CNF increased to 145.0°, which was 46% higher than that without the CNFs. The hydrophobicity of ceramic coatings with added CNFs was better because of changes in the surface topography. After coating and drying, the CNFs randomly accumulated inside the ceramic coating layer, forming a textured surface. Thus, hydrophobicity was improved by implementing a rugged ceramic surface without revealing the surface of the CNFs inside the ceramic layer.


2017 ◽  
Vol 12 (1) ◽  
pp. 155892501701200
Author(s):  
Züleyha Değirmenci ◽  
Ebru Çoruh

This paper reports the effect of loop length and raw material on the air permeability and the bursting strength of plain knitted fabrics. In this study, a series of plain knitted fabrics were produced on a circular knitting machine with cotton, polyester, acrylic and viscose by Ne 30/1 yarns. Each fabric type was produced with four different stitch lengths. All the fabrics were knitted at the same machine setting in order to determine the effect of their structure on the fabric properties. Their geometrical and physical properties were experimentally investigated. The influences of the loop length and the raw material on the number of the courses per cm, number of the wales per cm, loop shape factor, thickness, fabric unit weight, tightness factor, air permeability and bursting strength are analyzed. Statistical analysis indicates that raw material and loop length significantly parameters affect the air permeability and the bursting strength properties of the fabrics.


2013 ◽  
Vol 664 ◽  
pp. 129-132
Author(s):  
Sai Ming Yang

Ecological security is the basis of sustainable development.Ecological security assessment of land resources is a forefront research topic of sustainable utilization of land resources. A index system of twenty indicators on ecological security of land resources,including natural, economic and social aspects, is established. Using AHP method to determine the index weights and mathematical models to calculate ecological security values of land resources, Ecological security values of land resources are devided into five grades.


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