scholarly journals Current Aspects of Prevention of Coal Freezing by Means of Inorganic and Organic Reagents

2021 ◽  
Vol 100 ◽  
pp. 06003
Author(s):  
Ekaterina Shmeltser ◽  
Maryna Kormer ◽  
Vitalij Lyalyuk
Keyword(s):  
Alkaline Earth ◽  
Physicochemical Characteristics ◽  
Cold Season ◽  
Chemical Additives ◽  
Organic Reagents ◽  
Alkaline Metals ◽  
Structure Of Molecules ◽  
Coke Plants ◽  
Composition And Structure ◽  
Effective Use

In the cold season, irregular coal supplies to coke plants are aggravated by the need to heat the coal cars. Thawing of rail cars in garages (enclosures) is the least efficient and most expensive approach. Treatment of the coal concentrates with chemical additives reliably prevents freezing in winter during transit from suppliers to consumers. With a view to finding new reagents for preventing the freezing of coal in winter, the lime, the acetates and chlorides of alkaline-earth and alkaline metals are studied. Attention focuses on their physicochemical characteristics, methods of preparation and of introduction in coal concentrate, and their influence on freezing. The results of studies have shown that the use of organosilicon is more effective use of acetates and chlorides of metals. The high activity of organosilicon substances is explained by their elemental composition and structure of molecules.

ASPECTS OF CHEMICAL ADDITIVES IN FOODS1

1957 ◽  
Vol 20 (2) ◽  
pp. 44-48
Author(s):  
K. G. Weckel
Keyword(s):  
Community Development ◽  
Food Production ◽  
Food Distribution ◽  
Insect Control ◽  
Chemical Additives ◽  
Military Logistics ◽  
The Past ◽  
History Of ◽  
Military Campaigns ◽  
Effective Use

The history of man is closely associated with his food supplies; survival, migrations, community development, formation of government, military campaigns, religious worship, functions of politics. The ability of man to produce food in quantity for increasing populations is dependent upon effective use of fertilizers, insect, rodent, fungicide, miticide, weed, and simular controls, and mechanization. Insect control is an intense problem. The American farm enterprise is rapidly changing characteristics, in population, manpower output, available acreage, and acreage output. Food distribution practices also have changed markedly in the past decade. Military logistics have strong impacts on food production and utilization practices. The necessity for new forms of foods for shifting populations has resulted in re-evaluation of regulations governing the use of chemicals in foods, their functions, and effects.

scholarly journals Influence of composition and structure on the thermal quenching of the 5d–4f emission of Eu2+ doped M–Si–N (M = alkali, alkaline earth, rare earth) nitridosilicates

2019 ◽  
Vol 7 (21) ◽  
pp. 6289-6300 ◽  
Author(s):  
Otmar M. ten Kate ◽  
J. Ruud van Ommen ◽  
H. T. (Bert) Hintzen
Keyword(s):  
Rare Earth ◽  
Alkaline Earth ◽  
Thermal Quenching ◽  
Composition And Structure ◽  
The Eu

Thermal quenching of the Eu2+ emission in the nitridosilicates has been analysed and related to structure and composition.

Study of graphite-like materials obtained from coal-tar pitch

2020 ◽  
Vol 63 (7) ◽  
pp. 46-53
Author(s):  
Sergey A. Sozinov ◽  
◽  
Anna N. Popova ◽  
Larisa V. Sotnikova ◽  
Anastasiya S. Valnukova ◽  
...  
Keyword(s):  
Coal Tar ◽  
Functional Materials ◽  
Xrd Analysis ◽  
Physicochemical Characteristics ◽  
Coal Tar Pitch ◽  
Medium Temperature ◽  
Paramagnetic Resonance ◽  
Derivative Analysis ◽  
Composition And Structure ◽  
The Individual

In the research, the study of precursors of graphite-like materials obtained from medium-temperature coal tar pitch was carried out on the individual components of coal tar pitch by separating the multicomponent composition of the pitch into separate fractions. Such approach, to study the physicochemical characteristics of the individual components of coal tar pitch, contributes to both the determination of the contribution of individual pitch components to the process of its structuring during carbonization and the development of new environmentally friendly methods for the synthesis of functional materials for various applications. The β-fraction was precipitated with n-hexane from toluene extract of coal tar pitch. γ-fraction was isolated from n-hexane by solvent evaporation. α2-fraction was isolated from the residue, insoluble in toluene, by quinoline extraction. The composition and structure of the isolated individual fractions of coal tar pitch were studied by physicochemical methods of analysis. The shape and morphology were investigated by electron microscopy. To study the composition and structure, the methods of elemental analysis, infrared spectroscopy, electron-paramagnetic resonance, XRD-analysis, and thermoanalysis were used in combination with methods of derivative analysis, chromatography, and mass spectrometry. The authors of the work propose new approaches to the use of individual fractions of coal tar pitch in order to obtain new graphite-like materials on their basis.

Influence of the preparing conditions on the physicochemical characteristics of glasses for thick film hybrid microelectronics

1994 ◽  
Vol 9 (9) ◽  
pp. 2304-2313 ◽  
Author(s):  
M. Prudenziati ◽  
B. Morten ◽  
P. Savigni ◽  
G. Guizzetti
Keyword(s):  
Thick Film ◽  
Specular Reflection ◽  
Physicochemical Characteristics ◽  
Systematic Investigation ◽  
Glassy Matrix ◽  
Lead Glass ◽  
Preparation Methods ◽  
Composition And Structure ◽  
The Difference ◽  
High Lead

Seven batches of a high-lead glass were used for the preparation of RuO2-based thick film resistors. Investigation of their electrical properties showed a lack of reproducibility of results whose origin was related to changes of the physicochemical properties of the glassy matrix. A systematic investigation of the glass batches, both in form of frit powders and screen printed and fired layers, was carried out with several spectroscopies to detect changes in composition and structure. The spectroscopic methods included x-ray Energy Dispersive Fluorescence (EDS), Scanning Electron Microscopy (SEM), Atomic Absorption (AA), diffuse optical reflection of the powders and specular reflection of the layers, optical transmission, and other complementary methods. The dissolution of Al, due to interaction between the glasses and the alumina substrate, as well as the diffusivity and solubility of Ag due to interaction with the Ag-bearing terminations were measured. The results demonstrated that, apart from small compositional differences, the various batches were characterized by differences in residual stresses, redox reactions, and “microstructure.” The latter was responsible for very notable differences in the optical properties of the glasses, which in turn are closely related with the difference in atomic solubility and diffusivity. Optical spectroscopies have been found to be a suitable means for testing reproducible preparation methods of glass frits for thick-film hybrid microelectronics.

scholarly journals Quality of Sliced Cured Pork Loin with Spinach: Effect of Incubation Period with Starter Culture

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Tae-Kyung Kim ◽  
Hae In Yong ◽  
Hae Won Jang ◽  
Heeyoung Lee ◽  
Young-Boong Kim ◽  
...  
Keyword(s):  
Incubation Period ◽  
Starter Culture ◽  
Meat Products ◽  
Physicochemical Characteristics ◽  
Dependent Manner ◽  
Chemical Additives ◽  
Basic Nitrogen ◽  
Residual Nitrite ◽  
Pork Loin ◽  
Nitrite Content

An increasing concern about the usage of chemical additives in meat products has resulted in the use of natural ingredients instead of chemical additives in meat products. Therefore, this study aimed to investigate the effect of incubation period on the physicochemical characteristics of meat products cured with spinach and starter culture containing Staphylococcus carnosus. The pH, color, TBARS lipid oxidation, volatile basic nitrogen, residual nitrite content, and microbial number in cured pork loin were determined by incubating it with spinach and starter culture for the following durations: 3, 6, 9, 12, 24, and 48 h. The pH and TBARS values of cured pork loin incubated with spinach and starter culture decreased in a time-dependent manner. An increase in the incubation time from 3 to 48 h resulted in a significant increase in the redness and volatile basic nitrogen content. The residual nitrite content was observed to be maximum in samples from the I48 group followed by the control (+), preconverted nitrite group, and I24 groups. Thus, we found that incubation with spinach and starter culture for 24 h yields a good-quality cooked sliced cured pork loin.

scholarly journals Study of the influence of modern superplastificators on the properties of road cement concrete

2021 ◽  
Vol 2 (92) ◽  
pp. 74
Author(s):  
Serhii Tolmachov ◽  
Olena Belichenko ◽  
Oleksandr Moskalenkо ◽  
Yurii Pokusa
Keyword(s):  
Water Demand ◽  
Concrete Strength ◽  
Cement Concrete ◽  
Chemical Additives ◽  
Actual Problem ◽  
The Road ◽  
Concrete Mixtures ◽  
Modern Chemical ◽  
Cast Concrete ◽  
Effective Use

Abstract. In the technology of road concrete, the use of plasticizing additives is mandatory. In the last century, the most widely used plasticizers are lignosulfonates. These additives reduce the water demand of concrete mixtures by 10...15 % and increase the strength of concrete by 20...25 %. However, the presence of sugars in their composition leads to a strong slowdown of the hardening processes and can lead to a decrease the strength of concrete at the age of 28 days. In this century, modern superplasticizers based on polycarboxylates began to be widely used in industrial and civil construction. They were mainly used for the manufacture of cast concrete mixtures. On the other hand, their use in moderately mobile concrete mixes allows reducing water demand by 35...40 % and increasing strength by 60...100 % compared to concretes without additives. However, in such mixtures the use of polycarboxylates leads to a quick setting of the ce-ment and an accelerated set of concrete strength. This does not meet the requirements of the road concrete standards. The goal of the work is to study the influence of modern chemical additives of various nature on the basic properties of road cement con-crete. The article is devoted to the actual problem of the effective use of polycarboxylate superplasticizers

The factors determining the skin penetration and cellular uptake of nanocarriers: New hope for clinical development

2021 ◽  
Vol 27 ◽  
Author(s):  
Afsaneh Farjami ◽  
Sara Salatin ◽  
Samira Jafari ◽  
Mohammad Mahmoudian ◽  
Mitra Jelvehgari
Keyword(s):  
Drug Delivery ◽  
Skin Permeation ◽  
Direct Interaction ◽  
Skin Barrier ◽  
Skin Penetration ◽  
Physicochemical Characteristics ◽  
Skin Permeability ◽  
Topical Drug Delivery ◽  
Major Barrier ◽  
Composition And Structure

: The skin provides a protective barrier against toxic environments and also offers a valuable route for topical drug delivery. The stratum corneum (SC) is the outermost layer of the skin and serves as the major barrier to chemical transfer through the skin. The human skin barrier is particularly diffcult to overcome because of the complex composition and structure of the SC. Nanoparticulate carriers have gained widespread attention in topical drug delivery due to their tunable and versatile properties. The present review summarizes the main factors involved in the skin penetration of nanocarriers containing drug. Employment of nanotechnology in topical delivery has grown progressively during recent years; however, it is important to monitor the skin penetration of nanocarriers prior to their use due to avoid possible toxic effects. Nanocarriers can act as a means to increase the skin permeation of drugs by supporting a direct interaction with the SC and increasing the period of permanence on the skin. The skin penetration is influenced by the physicochemical characteristics of nanocarriers such as composition, size, shape, surface chemistry as well as skin features. Considering that the target of topical systems based on nanocarriers is the penetration of therapeutic agents in the skin layers, so a detailed understanding of the factors influencing skin permeability of nanocarriers is essential for safe and efficient therapeutic applications.

Mechanisms of grinding modification by chemical additives: organic reagents

1984 ◽  
Vol 38 (3) ◽  
pp. 267-273 ◽  
Author(s):  
H. El-Shall ◽  
P. Somasundaran
Keyword(s):  
Chemical Additives ◽  
Organic Reagents
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