scholarly journals USING TECHNICAL SULFUR AS A STRUCTURING ADDITIVE FOR MINERAL BINDERS BASED ON CALCIUM SULFATE

2020 ◽  
Vol 11 (3) ◽  
pp. 95-100
Author(s):  
Grigorij I. Yakovlev ◽  
Irina S. Polyanskih ◽  
Anastasia F. Gordina ◽  
Aleksandr N. Gumeniuk
Keyword(s):  
Calcium Sulfate ◽  
Building Materials ◽  
Chemical Properties ◽  
Additional Treatment ◽  
Production Waste ◽  
Structure And Properties ◽  
Technical Parameters ◽  
Research Activities ◽  
And Performance ◽  
Physical And Chemical

The article discusses physical and chemical characteristics of producing effective materials based on calcium sulfate dihydrate, the pretreated waste of man-made production being added at the stage of mixing the air binder. The high degree of consumption of exhaustible natural resources causes increased research activities in the field of application of industrial waste in construction. Using manmade waste, such as technical sulfur, as a modifier of the structure and properties of building materials is a significant step in solving environmental, resource, and economic problems. Industrial production of building materials today follows the principles of sustainable development and waste minimization by optimizing product formulations and reducing energy consumption required for their production. In addition, the improvement of quality and performance indicators of standardized products is relevant and sought-after. The need for efficient technologies for utilization of technical sulfur is due to large volumes of production and the environmental threat which accompanies the storage of its large volumes. Adding technical sulfur as a component of technological construction mixtures will create an alternative to the methods of utilization of this production waste. Physical and technical and physical and chemical properties of technical sulfur predetermine the possibility of its use, with certain additional treatment, as an effective modifier of the structure and properties of gypsum products. The results presented in the article prove the potential use of this production waste as an effective structure-forming additive, which has a positive effect on the physical and technical parameters of calcium sulfate-based materials.

Nanocrystals: The Preparation, Precise Control and Application Toward the Pharmaceutics and Food Industry

2018 ◽  
Vol 24 (21) ◽  
pp. 2425-2431 ◽  
Author(s):  
Cao Wu ◽  
Zhou Chen ◽  
Ya Hu ◽  
Zhiyuan Rao ◽  
Wangping Wu ◽  
...  
Keyword(s):  
Food Industry ◽  
Chemical Properties ◽  
Preparation Methods ◽  
Precise Control ◽  
Significant Process ◽  
Technology Applications ◽  
And Performance ◽  
Physical And Chemical ◽  
Analytical Technology ◽  
And Chemical Properties

Crystallization is a significant process employed to produce a wide variety of materials in pharmaceutical and food area. The control of crystal dimension, crystallinity, and shape is very important because they will affect the subsequent filtration, drying and grinding performance as well as the physical and chemical properties of the material. This review summarizes the special features of crystallization technology and the preparation methods of nanocrystals, and discusses analytical technology which is used to control crystal quality and performance. The crystallization technology applications in pharmaceutics and foods are also outlined. These illustrated examples further help us to gain a better understanding of the crystallization technology for pharmaceutics and foods.

scholarly journals The influence of sulfate availability on rheology of fresh cement paste

2020 ◽  
Vol 30 (1) ◽  
pp. 54-63
Author(s):  
Willy Mbasha ◽  
Rainer Haldenwang ◽  
Irina Masalova
Keyword(s):  
Yield Stress ◽  
Calcium Sulfate ◽  
Chemical Properties ◽  
Plastic Viscosity ◽  
Cement Clinker ◽  
Flow Properties ◽  
Cement Pastes ◽  
Hardened Properties ◽  
Physical And Chemical ◽  
And Chemical Properties

AbstractNatural gypsum can degenerate into hemihydrate during cement clinker grinding which changes the physical and chemical properties of cement hydration, affecting therefore the fresh and hardened properties of cement based materials. Cement systems containing a constant total amount of calcium sulfate (4%) with relative proportions of hemihydrate and natural gypsum were considered. Rheological measurements were executed on an Anton Paar MCR51 rheometer to evaluate the flow properties of cement pastes. Results show that, the yield stress and the plastic viscosity of cement pastes were affected when the degeneration of natural gypsum exceeded 50%. Above this concentration, the yield stress remarkably increased and a variation in plastic viscosity of about 50% was observed. Using TG-DSC techniques, it was shown that, the amount of formed ettringite could not explain these rheological changes. However, centrifugational packing and SEM-SE measurements confirmed that, more than the amount of ettringite precipitated, ettringite morphology plays a major role in controlling the yield stress and plastic viscosity of fresh cement pastes.

scholarly journals Testing Engine Oil Specifications and Properties and its Effects on the Engines Maintenance and Performance

2020 ◽  
Vol 15 ◽  
Keyword(s):  
Chemical Properties ◽  
Mechanical Tests ◽  
Engine Oil ◽  
Strong Relation ◽  
Degree Of Stability ◽  
And Performance ◽  
The Cost ◽  
Motor Oils ◽  
Physical And Chemical ◽  
And Chemical Properties

This paper presents the results of practical mechanical tests of motor oils, their specifications and characteristics and the effect of their physical and chemical properties on the performance of the engine. The performance of the engine has a strong relation with the engine oil type and efficiency. The degree of stability of oils properties is very important because if oil or lubricants lose their properties, mechanical and chemical excessive corrosion of the motor metals may occur. Consequently, damage occurs to one or more parts of the engine, thereby the system is breaking down where the cost of downtime is too expensive. It has been found that a higher viscosity value is not the optimum as it increases temperature and energy consumption due to frictional losses. The values required for viscosity is the ideals that gives the stable results regardless temperature variations under any conditions of operation, at which the power losses are minimal and the fuel economy is optimal.

The Comparative Analysis of Lime Burst between Sintered Shale Brick and Light-Weight Sintered Brick

2012 ◽  
Vol 450-451 ◽  
pp. 683-687
Author(s):  
Bang Biao Huang ◽  
Jia Hua Jing ◽  
Ji Zhen Zhu ◽  
Cai Xia Chen ◽  
Shan Luo
Keyword(s):  
Raw Materials ◽  
Tensile Force ◽  
Chemical Properties ◽  
Light Weight ◽  
Technical Parameters ◽  
Research Production ◽  
Wall Materials ◽  
Physical And Chemical ◽  
And Chemical Properties

The sintered shale brick and light-weight sintered shale brick are both of brittle wall materials. The mechanical and other properties will be affected greatly by tensile force producing the lime burst. Through analysis of physical and chemical properties of raw materials, the reason of lime burst, and the comparative experiments of lime burst, studied on similarities and differences between the two wall materials, providing important technical parameters for the follow-up research, production and construction in the feature.

Effects of dimethyl carbonate fuel additive on diesel engine performances

2005 ◽  
Vol 219 (7) ◽  
pp. 897-903 ◽  
Author(s):  
G D Zhang ◽  
H Liu ◽  
X X Xia ◽  
W G Zhang ◽  
J H Fang
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Diesel Engines ◽  
Dimethyl Carbonate ◽  
Chemical Properties ◽  
Fuel Additive ◽  
High Oxygen Content ◽  
Combustion Duration ◽  
And Performance ◽  
Physical And Chemical

The physical and chemical properties of some oxygenated compounds are discussed, including dimethoxymethane (methylal, or DMM), dimethyl carbonate (DMC), and ethyl acetate. In particular, DMC may be a promising additive for diesel fuel owing to its high oxygen content, no carbon-carbon atomic bonds, suitable boiling point, and solubility in diesel fuel. The aim of this research was to study the combustion characteristics and performance of diesel engines operating on diesel fuel mixed with DMC. The experimental results have shown that particulate matter (PM) emissions can be reduced using the DMC oxygenated compound. The combustion analysis indicated that the ignition delay of the engine fuelled with DMC-diesel blended fuel is longer, but combustion duration is much shorter, and the thermal efficiency is increased compared with that of a base diesel engine. Further, if injection is also delayed, NOx emissions can be reduced while PM emissions are still reduced significantly. The experimental study found that diesel engines fuelled with DMC additive had improved combustion and emission performances.

Preparation and Performance of Andalusite Bonded SiC Solar Heat-Absorbing Ceramics

2013 ◽  
Vol 320 ◽  
pp. 52-59
Author(s):  
Jian Feng Wu ◽  
Meng Liu ◽  
Xiao Hong Xu ◽  
Ya Xiang Zhang ◽  
Kun Li ◽  
...  
Keyword(s):  
Thermal Shock ◽  
Bending Strength ◽  
Thermal Power ◽  
Chemical Properties ◽  
Xrd Analysis ◽  
Expansion Rate ◽  
Testing Technology ◽  
Firing Shrinkage ◽  
And Performance ◽  
Physical And Chemical

Using andalusite, SiC, Su Zhou Kaolin and Guang Xi quartz as materials, andalusite bonded SiC heat absorbing ceramic was prepared by pressureless firing in the ceramic preparation process. The influence of gradient SiC on microstructure and properties of the samples were studied. Using the testing technology of XRD, SEM, and etc., physical and chemical properties, phase composition and microstructure were tested and analysised.The results indicate that andalusite bonded SiC heat absorbing ceramic, which prepared to have a low firing shrinkage rate, high refractoriness and a good microstructure. The best firing temperature of the best formula C4 is 1460°C, firing expansion rate is 0.98%, bending strength is 32.52MPa,porosity is 30.74%, bulk density is 2.05g·cm-3, refractoriness is 1650°C,growth rate of oxidation weight is 2.769mg·cm-2and have no crack after 30 times thermal shock. The bending strength has increased 11.15% after thermal shock. XRD analysis indicated that the main phase compositions are α-SiC, mullite and cristobalite.SEM studies show that there are many connected pores in the samples, the diameters of the pores are 10~20μm. Andalusite bonded SiC heat absorbing ceramic have a low firing expansion rate, high bending strength and good microstructure, which is suit for tower type solar thermal power generation.

scholarly journals NANOTECHNOLOGIES IN CONSTRUCTION

2021 ◽  
pp. 7-14
Author(s):  
O.S. BALAN
Keyword(s):  
Food Packaging ◽  
Building Materials ◽  
Chemical Properties ◽  
Practical Significance ◽  
Construction Sector ◽  
Long Term Effects ◽  
Daily Lives ◽  
Building Product ◽  
The Many ◽  
Physical And Chemical

Problem statement. Cosmetics, clothing, and even food packaging: nanomaterials have invaded our daily lives. The construction and construction sector is no exception, and is undoubtedly one of the largest users of this technology. It is difficult to know if a building product contains nanomaterials. Indeed, unlike certain products, such as cosmetics, food or biocides (insecticides, detergents), no regulations establish special labeling. However, they are very widespread and are used to improve the properties of most materials: cement, plaster, glass, tiles, insulation metals, paints, etc. The benefits of using nanoparticles in construction are huge, promising extraordinary physical and chemical properties for modified building materials. Among the many different types of nanoparticles, titanium dioxide, carbon nanotubes, silicon dioxide, copper, clay, and aluminum oxide are the most widely used nanoparticles in the construction sector [1]. The purpose of this article is to analyze the use of nanoparticles in the construction industry to illustrate the benefits of using nanoparticles and address the short − and long-term effects of nanoparticles on the environment and human health in the microcosm of industry, so that the results can be generalized. Results. The use of nanotechnologies in construction and their properties are analyzed. Scientific novelty and practical significance. The problem of using nanothenologies in construction is analyzed.

scholarly journals Utilization of Pet Wastes Aggregate in Building Construction - A Review

2020 ◽  
Vol 9 (3) ◽  
pp. 656-663
Keyword(s):  
Building Materials ◽  
Construction Materials ◽  
Chemical Properties ◽  
Waste Recycling ◽  
Building Construction ◽  
Recycled Pet ◽  
Pet Waste ◽  
Physical And Chemical ◽  
Plastic Containers ◽  
And Chemical Properties

The rapid increase of plastics waste produced worldwide today poses a danger to human health because of the pollution caused by the unsafe disposal and non-biodegradability of this waste combined with toxic gas emissions during incineration. Globally, PET (polyethylene terephalate) is commonly used for bottling water and other plastic containers. Recycling the waste would be an additional benefit. This study focuses some researchers on the forms, methods of recycling and various literature applications of PET wastes. Recycled PET can of course be used when combined with the sand aggregate to manufacture of various construction materials, such as tiles, bricks, paving stones etc. This research focuses on its application as it attracts substantial building materials such as the manufacture of various PET waste tiles and their unique mechanical , physical and chemical properties; There are some important studies discussed in relation to PET waste, recycling methods , and results from the study. Even various applications are described here. Its usefulness is further defined as roofing Composite concrete, floor tiling and other applications

Sign in / Sign up

Export Citation Format

Share Document