Fundamental interaction of hydrophobic materials in concrete with different moisture contents in saline environment

AbstractThe phenomenon of the smoulder stream flowing through the cigarette during smouldering and during the puff intervals is demonstrated for the first time and its dependence upon physical conditions is examined. The volume of the smoulder stream can amount up to 180 ml per cigarette. Increasing draw resistance of the cigarette and augmenting moisture content of the tobacco as well as perforation of the cigarette paper have a decreasing effect on volume and velocity of the smoulder stream. The porosity of the cigarette paper has no perceptible influence. The spatial position of the cigarette affects volume and velocity of the smoulder stream. The influence exercised by the smoulder stream on the yields of total condensate, nicotine, phenols, aldehydes, and acroleine when the cigarette tip is open during the puff intervals is determined. When the moisture contents of the tobacco were extremely high, yield decreases reaching 50 % could be observed.

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A Study On Microbial Population Under The Effect Of Some Pesticides In Different Soil Orders And Moisture Contents

Journal of Raparin University ◽

10.26750/jru.1021 ◽

2018 ◽

Vol 5 (14) ◽

pp. 75-98

Author(s):

Nashmeel Khudhur ◽

Abdul-ghany Sarmamy

Keyword(s):

Microbial Population ◽

Moisture Contents

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Impact of climate and bulking materials on characteristics of compost from ecological toilets

Journal of Water Sanitation and Hygiene for Development ◽

10.2166/washdev.2012.059 ◽

2012 ◽

Vol 2 (2) ◽

pp. 79-86 ◽

Cited By ~ 3

Author(s):

James W. McKinley ◽

Rebecca E. Parzen ◽

Álvaro Mercado Guzmán

Keyword(s):

Low Carbon ◽

Pathogen Inactivation ◽

High Ph ◽

Moisture Contents ◽

Urine Diversion ◽

Ph Values ◽

Dominant Process ◽

Nitrogen Ratio ◽

Storage Times ◽

Carbon Concentrations

Urine-diversion dehydration toilets (UDDT) are common throughout the developing world, and the toilet product is widely used as compost. There is no comprehensive research to date that characterizes the compost to determine its quality, extent of pathogen inactivation, and the effects of climate and bulking materials on the compost. Compost was collected from 45 UDDT in Bolivia and analyzed for physical, chemical, and biological parameters. Eighty percent and 56% of samples did not meet acceptable compost guidelines for moisture content and pH, respectively, indicating desiccation was the dominant process in UDDT. Bulking materials significantly impacted compost characteristics in terms of pH, carbon, carbon-to-nitrogen ratio, and carbon stability (P < 0.05). Composts with ash exhibited, on average, low carbon concentrations (4.9%) and high pH values (9.7), which can be harmful to plants and composting microorganisms. Composts with sawdust exhibited, on average, high carbon concentrations (40.0%) and carbon-to-nitrogen ratios (31.0). Climate had no significant impact on chemical characteristics, however composts from humid regions had significantly higher moisture contents (34.4%) than those from arid climates (24.8%) (P < 0.05). Viable Ascaris lumbricoides ova were identified in 31% of samples, including samples with high pH, low moisture contents, and long storage times.

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High‐temperature performance and cross‐linking mechanism of different types of gel systems in saline environment

Journal of Applied Polymer Science ◽

10.1002/app.51452 ◽

2021 ◽

pp. 51452

Author(s):

Jianbin Liu ◽

Liguo Zhong ◽

Zijuan Cao ◽

Tongchun Hao ◽

Yigang Liu ◽

...

Keyword(s):

High Temperature ◽

Cross Linking ◽

Saline Environment ◽

Temperature Performance ◽

Different Types

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Performance Optimisation of Fuel Pellets Comprising Pepper Stem and Coffee Grounds through Mixing Ratios and Torrefaction

Energies ◽

10.3390/en14154667 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4667

Author(s):

Sunyong Park ◽

Hui-Rim Jeong ◽

Yun-A Shin ◽

Seok-Jun Kim ◽

Young-Min Ju ◽

...

Keyword(s):

Calorific Value ◽

Basic Information ◽

Spent Coffee Grounds ◽

Mixing Ratios ◽

Moisture Contents ◽

Fuel Pellets ◽

Coffee Grounds ◽

Coffee Ground ◽

Fuel Characteristics ◽

By Products

Agricultural by-products have several disadvantages as fuel, such as low calorific values and high ash contents. To address these disadvantages, this study examined the mixing of agricultural by-products and spent coffee grounds, for use as a solid fuel, and the improvement of fuel characteristics through torrefaction. Pepper stems and spent coffee grounds were first dried to moisture contents of <15% and then combined, with mixing ratios varying from 9:1 to 6:4. Fuel pellets were produced from these mixtures using a commercial pelletiser, evaluated against various standards, and classified as grade A, B, or Bio-SRF. The optimal ratio of pepper stems to spent coffee grounds was determined to be 8:2. The pellets were torrefied to improve their fuel characteristics. Different torrefaction temperatures improved the mass yields of the pellets to between 50.87% and 88.27%. The calorific value increased from 19.9% to 26.8% at 290 °C. The optimal torrefaction temperature for coffee ground pellets was 230 °C, while for other pellets, it was 250 °C. This study provides basic information on the potential enhancement of agricultural by-products for fuel applications.

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Non-adhesive lotus and other hydrophobic materials

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2007.2171 ◽

2008 ◽

Vol 366 (1870) ◽

pp. 1539-1556 ◽

Cited By ~ 116

Author(s):

David Quéré ◽

Mathilde Reyssat

Keyword(s):

Solid Surface ◽

Room Temperature ◽

Water Repellency ◽

Short Review ◽

Water Repellent ◽

Practical Applications ◽

Hydrophobic Materials ◽

Volatile Liquid ◽

Air Cushion ◽

The Stability

Superhydrophobic materials recently attracted a lot of attention, owing to the potential practical applications of such surfaces—they literally repel water, which hardly sticks to them, bounces off after an impact and slips on them. In this short review, we describe how water repellency arises from the presence of hydrophobic microstructures at the solid surface. A drop deposited on such a substrate can float above the textures, mimicking at room temperature what happens on very hot plates; then, a vapour layer comes between the solid and the volatile liquid, as described long ago by Leidenfrost. We present several examples of superhydrophobic materials (either natural or synthetic), and stress more particularly the stability of the air cushion—the liquid could also penetrate the textures, inducing a very different wetting state, much more sticky, due to the possibility of pinning on the numerous defects. This description allows us to discuss (in quite a preliminary way) the optimal design to be given to a solid surface to make it robustly water repellent.

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A methodology for hygrothermal modelling of imperfect masonry interfaces

Journal of Building Physics ◽

10.1177/1744259121989388 ◽

2021 ◽

pp. 174425912198938

Author(s):

Michael Gutland ◽

Scott Bucking ◽

Mario Santana Quintero

Keyword(s):

Boundary Conditions ◽

Material Properties ◽

Structural Integrity ◽

Bulk Material ◽

Weather Conditions ◽

Masonry Wall ◽

Two Dimensional ◽

Liquid Transport ◽

Imperfect Contact ◽

Moisture Contents

Hygrothermal models are important tools for assessing the risk of moisture-related decay mechanisms which can compromise structural integrity, loss of architectural features and material. There are several sources of uncertainty when modelling masonry, related to material properties, boundary conditions, quality of construction and two-dimensional interactions between mortar and unit. This paper examines the uncertainty at the mortar-unit interface with imperfections such as hairline cracks or imperfect contact conditions. These imperfections will alter the rate of liquid transport into and out of the wall and impede the liquid transport between mortar and masonry unit. This means that the effective liquid transport of the wall system will be different then if only properties of the bulk material were modelled. A detailed methodology for modelling this interface as a fracture is presented including definition of material properties for the fracture. The modelling methodology considers the combined effect of both the interface resistance across the mortar-unit interface and increase liquid transport in parallel to the interface, and is generalisable to various combinations of materials, geometries and fracture apertures. Two-dimensional DELPHIN models of a clay brick/cement-mortar masonry wall were created to simulate this interaction. The models were exposed to different boundary conditions to simulate wetting, drying and natural cyclic weather conditions. The results of these simulations were compared to a baseline model where the fracture model was not included. The presence of fractures increased the rate of absorption in the wetting phase and an increased rate of desorption in the drying phase. Under cyclic conditions, the result was higher peak moisture contents after rain events compared to baseline and lower moisture contents after long periods of drying. This demonstrated that detailed modelling of imperfections at the mortar-unit interface can have a definitive influence on results and conclusions from hygrothermal simulations.

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Tissue tolerance mechanisms conferring salinity tolerance in a halophytic perennial species Nitraria sibirica Pall.

Tree Physiology ◽

10.1093/treephys/tpaa174 ◽

2020 ◽

Author(s):

Xiaoqian Tang ◽

Huilong Zhang ◽

Sergey Shabala ◽

Huanyong Li ◽

Xiuyan Yang ◽

...

Keyword(s):

Plant Root ◽

Transcriptional Level ◽

Distribution Analysis ◽

Specific Level ◽

Saline Environment ◽

Nitraria Sibirica ◽

Mechanistic Basis ◽

Plant Salt Tolerance ◽

Cellular Compartments ◽

Growth Of Seedlings

Abstract Plant salt tolerance relies on a coordinated functioning of different tissues and organs. Salinity tissue tolerance is one of the key traits that confers plant adaptation to saline environment. This trait implies maintenance low cytosolic Na+/K+ ratio in metabolically active cellular compartments. In this study, we used Nitraria sibirica Pall., a perennial woody halophytes species, to understand the mechanistic basis of its salinity tissue tolerance. The results showed that the growth of seedlings was stimulated by 100-200 mM NaCl treatment. The ions distribution analysis showed that the leaves acted as Na+ sink while plant root possess superior K+ retention. The excessive Na+ absorbed from soil was mainly transported to the shoot and eventually sequestrated into mesophyll vacuoles in the leaves. As a result, N. sibirica could keep optimal balance of K+/Na+ at a tissue- and cell-specific level under saline condition. To enable this, N. sibirica increased both vacuolar H+-ATPase and H+-PPase enzymes activities and up-regulated expressions of NsVHA, NsVP1 and NsNHX1 genes. Vacuolar Na+ sequestration in the leaf mesophyll mediated by NsVHA, NsVP1 and NsNHX1 reduced the Na+ concentration in cytosol and inhibited further K+ loss. Meanwhile, N.sibirica enhanced the TPK expression at the transcriptional level to promote K+ efflux from vacuole into cytoplasm, assisting in maintaining cytosolic K+ homeostasis. It is concluded that the tissue tolerance traits such as vacuolar Na+ sequestration and intracellular K+ homeostasis is critical to confer adaptation of N. sibirica to soil salinity.

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