Analysis of the Formation Mechanism of Hollow and Cricoid Stria in Formed Coke

2011 ◽  
Vol 287-290 ◽  
pp. 2927-2932
Author(s):  
Ming Jie Ma ◽  
Quan Run Liu ◽  
Shan Xiu Huang
Keyword(s):  
Heat Conduction ◽  
Chemical Reaction ◽  
Formation Mechanism ◽  
Chemical Change ◽  
Experimental Conditions ◽  
Carbonization Process ◽  
Physical And Chemical

Under certain experimental conditions, the formed coke with hollow and cricoid stria. Through the perfect supposition about briquette carbonization process, the formation mechanism of the hollow and cricoid stria in formed coke is analyzed and the property of physical and chemical change and their conditionality relationship during briquette carbonated are demonstrated by use of the rules of heat conduction, the chemical reaction in the melting stage of colloid matter in coal and hydrodynamics. The conclusions from above analysis has an important instruction for the preparation mechanism of other allied carbon stuff.

scholarly journals Investigation of the Formation Mechanism and Environmental Risk of Tire—Pavement Wearing Waste (TPWW)

2021 ◽  
Vol 13 (15) ◽  
pp. 8172
Author(s):  
Kechen Wang ◽  
Xiangyu Chu ◽  
Jiao Lin ◽  
Qilin Yang ◽  
Zepeng Fan ◽  
...  
Keyword(s):  
Formation Mechanism ◽  
Organic Contaminants ◽  
Asphalt Mixture ◽  
Fine Fraction ◽  
Crumb Rubber ◽  
Environmental Benefit ◽  
The Road ◽  
Open Graded Friction Course ◽  
Volatile Alkanes ◽  
Physical And Chemical

Tire—pavement interaction behaviours result in large amounts of wearing waste matter, which attaches to the surface of the pavement and is directly exposed to the surrounding environment. This kind of matter imposes a great challenge to the environment of the road area. The current study is devoted to carrying out a comprehensive investigation of the formation mechanism of tire—pavement wearing waste (TPWW), as well as the resulting environmental risks. A self-developed piece of accelerated polishing equipment, the Harbin advanced polishing machine (HAPM), was employed to simulate the wearing process between vehicle tires and pavement surfaces, and the TPWW was collected to conduct morphological, physical, and chemical characterisations. The results from this study show that the production rate of TPWW decreases with the increase in polishing duration, and the coarse particles (diameters greater than 0.425 mm) account for most of the TPWW obtained. The fine fraction (diameter smaller than 0.425 mm) of the TPWW comprises variously sized and irregularly shaped rubber particles from the tire, as well as uniformly sized and angular fine aggregates. The environmental analysis results show that volatile alkanes (C9–C16) are the major organic contaminants in TPWW. The Open-Graded Friction Course (OGFC) asphalt mixture containing crumb rubber as a modifier showed the highest risk of heavy metal pollution, and special concern must be given to tire materials for the purpose of improving the environmental conditions of road areas. The use of polyurethane as a binder material in the production of pavement mixtures has an environmental benefit in terms of pollution from both organic contaminants and heavy metals.

scholarly journals The influence of temperature on the absorption of water by seeds of hordeum vulgare in relation to the temperature coefficient of chemical change

1912 ◽  
Vol 85 (582) ◽  
pp. 546-553 ◽  
Keyword(s):  
Hordeum Vulgare ◽  
Aqueous Solutions ◽  
Temperature Coefficient ◽  
Chemical Change ◽  
Experimental Conditions ◽  
Influence Of Temperature ◽  
Suitable Medium ◽  
Influence Of Temperature On

Attention has previously been directed by one of us to the existence of a differential septum enclosing the seeds of Hordeum (barley). When the seeds are immersed in aqueous solutions of most electrolytes, and of many non-electrolytes, this covering behaves as a very efficient differential septum, water alone entering the seeds under the attractive influence of the finely granulated contents. The rate at which the water enters is considerably affected if substances are dissolved in it, being increased by some and diminished by others; it is also markedly dependent on the temperature of the water or solution in which the seeds are immersed. Variations of the rate at which water enters with alterations of the experimental conditions are presumably due mainly to changes in the water, and the seeds of Hordeum would thus appear to be a very suitable medium for the investigation of the nature of the changes produced in water by the presence of dissolved substances or by alterations of temperature.

scholarly journals The Photocatalytic Activity of Cement in Reducing Air Pollutants

2019 ◽  
Vol 8 (6S3) ◽  
pp. 1422-1424
Keyword(s):  
Climate Change ◽  
Air Pollution ◽  
Global Warming ◽  
Photocatalytic Activity ◽  
Ion Chromatography ◽  
Air Pollutants ◽  
Experimental Conditions ◽  
Open Environment ◽  
Physical And Chemical ◽  
The Ideal

Air pollution is the major concern in the recent years because of causing imbalance to the ecosystem and also increases global warming and climate change. This paper, tries to investigate the applicability of photo catalytic cement in removing the pollutants under partially controlled and simpler experimental conditions such that it mimics the ideal state of its use, that is the natural open environment where it always is susceptible to complex physical and chemical interactions. It also gives an overview of the concentrations of the contaminants reduced not limiting to NOx residues alone, by employing Ion Chromatography instead of NOx analyzers.

Granite Weathering

2006 ◽  
Author(s):  
Piotr Migon
Keyword(s):  
Solid Rock ◽  
Chemical Change ◽  
Transitional Zone ◽  
Sufficient Evidence ◽  
Small Scale ◽  
Bare Rock ◽  
Moisture Deficit ◽  
Geomorphic Features ◽  
Drying Up ◽  
Physical And Chemical

Weathering is a necessary precursor for landform development. However, in the context of granite it acquires a particular importance for various reasons. First, many granite terrains show an extensive development of deep weathering profiles, which can be extremely varied in terms of their depth, vertical zonation, degree of rock decomposition, and mineralogical and chemical change. Moreover, the transitional zone between the weathering mantle and the solid rock, for which the term ‘weathering front’ is used (Mabbutt, 1961b), may be very thin. There is now sufficient evidence that many geomorphic features of granite landscapes, including boulders, domes, and plains, have been sculpted at the solid rock/weathering mantle interface and they are essentially elements of an exposed weathering front. Therefore, the origin of granite landscapes cannot be satisfactorily explained and understood without a proper understanding of the phenomenon of deep weathering. Second, granites break down via a range of weathering mechanisms, both physical and chemical, which interact to produce an extreme diversity of small-scale surface features and minor landforms. In this respect, it is only limestones and some sandstones which show a similar wealth of weathering-related surface phenomena. Third, both superficial and deep weathering of granite act very selectively, exploiting a variety of structural and textural features, including fractures, microfractures, veins, enclaves, and textural inhomogeneities. In effect, the patterns of rock breakdown may differ very much between adjacent localities, and so the resultant landforms differ. In the context of deep weathering, selectivity is evident in significant changes of profile thickness and its properties over short distances, and in the presence of unweathered compartments (corestones) within an altered rock mass. Fourth, it is emphasized that granites are particularly sensitive to the amount of moisture in the environment (Bremer, 1971; Twidale, 1982). They alter very fast in moist environments, whereas moisture deficit enhances rock resistance and makes it very durable. Hence, a bare rock slope shedding rainwater and drying up quickly after rain will be very much immune to weathering, whereas at its foot a surplus of moisture will accelerate decomposition.

Analytical Methodology from Lavoisier to Mendeleev

2014 ◽  
Author(s):  
Marco Fontani ◽  
Mariagrazia Costa ◽  
Mary Virginia Orna
Keyword(s):  
Chemical Change ◽  
Chemical Properties ◽  
Professional Activity ◽  
Analytical Methodology ◽  
Long Run ◽  
Similar Chemical ◽  
Experimental Errors ◽  
Ancient Times ◽  
Almost All ◽  
Physical And Chemical

Within the period covered by Part II, 1789–1869, 37 true elements, almost all of them metals, were discovered. Prior to this time, about 14 metals had been discovered, excluding those that had been known from ancient times. The discovery of the elements during this period of interest is intimately related to the analytical methodologies available to chemists, as well as to a growing consciousness of just what an element is. Because these methods were also available to the less competent who may have lacked the skills to use them or the knowledge to interpret their results, their use also led to as many, if not more, erroneous discoveries in the same period. One can number among the major sources of error faulty interpretation of experimental data, the “rediscovery” of an already known element, sample impurities, very similar chemical properties (as in the case of the rare earths), the presence of an element in nature in very scarce or trace amounts, gross experimental errors, confusion of oxides and earths with their metals, and baseless dogmatic pronouncements by known “authorities” in the field. Antoine Laurent Lavoisier’s conceptualization of what constitutes an element was a radical break from the principles of alchemy. His stipulation that an element is a substance that cannot be further decomposed conferred an operational, pragmatic, concrete definition on what had previously been a more abstract concept. At the other end of the spectrum was the intuition of Dmitri Mendeleev who, contrary to the prevailing acceptance of Lavoisier’s concept, stressed the importance of retaining a more abstract, more fundamental sense of an element—an idea that in the long run enabled the development of the periodic table. What both men had in common is that they defined and named individual elements as those components of substances that could survive chemical change and whose presence in compounds could explain their physical and chemical properties. Mendeleev’s table has been immortalized in every chemistry classroom—and also concretely in Saint Petersburg, the city that saw most of his professional activity, by a spectacular building-sized model The analytical chemist depends on both of these concepts and indeed, analytical practice preceded Lavoisier’s concept by at least a century.

Role of Variable Conductance on Heat and Mass Transport Mechanism Using Generalized Theory

2020 ◽  
Vol 13 (2) ◽  
Author(s):  
Imran Haider Qureshi ◽  
Ahmed Elmoasry ◽  
Jawdat Alebraheem ◽  
M. Nawaz
Keyword(s):  
Thermal Conductivity ◽  
Heat Conduction ◽  
Chemical Reaction ◽  
Diffusion Coefficients ◽  
Mass Diffusion ◽  
Memory Effects ◽  
Temperature Dependent ◽  
Newton's Law ◽  
Newton’S Law ◽  
The Impact

Abstract Fourier law of heat conduction, its analog Fick's first law, and Newton's law of viscosity are classical laws that are not capable of exhibiting memory effects. Conservation laws based on these classical laws do not give predictions about memory effects on the transport phenomena. Recently, proposed novel laws are called Cattaneo–Christov heat flux. Models are based on the generalization of classical laws of heat conduction, mass diffusion, and Newton's law of viscosity. This investigation considers this generalized theory to model the impact of relaxation phenomenon on the transport of momentum, heat, and mass in Maxwell fluid (viscoelastic fluid) of temperature-dependent viscosity and thermal conductivity in the presence of temperature-dependent mass diffusion coefficients. It is observed from the simulations that memory effects play a key role in controlling momentum, thermal and concentration boundary layer thicknesses. It is also noted that the rate of diffusion of heat and mass has shown an increasing trend when thermal conductivity and mass diffusion coefficients are increased via rise in temperature of the fluid. The generative chemical reaction on the transport of specie relative to the impact on the transport of specie when it is compared with the impact of destructive chemical reaction on the transport of specie.

The Reactions of Aniline and Its Homologs as Accelerators of Vulcanization

1928 ◽  
Vol 1 (2) ◽  
pp. 307-340
Author(s):  
Takeo Kimishima
Keyword(s):  
Reaction Mechanism ◽  
Chemical Reaction ◽  
Satisfactory Result ◽  
Chemical Change ◽  
The Other ◽  
Chemical Effect ◽  
Reaction Products ◽  
Thermal Change ◽  
Points Of View ◽  
The One

Abstract The accelerating action of aniline and its homologs can be considered from two points of view. The one is whether there are exothermic phenomena caused by the accelerators and the effect of those phenomena upon vulcanization. The other is the chemical effect upon vulcanization caused by reaction products derived as a result of chemical reaction of an accelerator and sulfur. In other words, the object of consideration in the former is the effect of thermal change, while that in the latter is the effect caused by chemical change. Leaving the former for later discussion, the writer will first describe the result of his experiments concerning the reaction products of accelerators and sulfur and the effect of these products upon vulcanization. In an investigation of this kind it is extremely difficult to extract and determine the effective elements from material derived from an accelerator in the process of vulcanizing reactions of rubber. No case has yet been known where a satisfactory result was realized by such a method. Therefore, the writer has first taken up the investigations of reactions of an accelerator with sulfur and by separating and refining each of the various reaction products approached the matter of vulcanization itself, and under various conditions caused these reaction products to act upon rubber. Thus the writer has followed the plan of establishing the reaction mechanism of accelerators by seeing the changes, both chemical and physical, together with their effect upon vulcanization.

Physical and chemical change in textbooks: An initial view

1996 ◽  
Vol 26 (1) ◽  
pp. 129-140 ◽  
Author(s):  
Bill Palmer ◽  
David F Treagust
Keyword(s):  
Chemical Change ◽  
Physical And Chemical
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