scholarly journals INFLUENCE OF DIFFERENT ASSORTMENT OF TWO-BALL GRINDING LOAD ON THE PERFORMANCE OF AN OPEN-CYCLE BALL MILL

2021 ◽  
Vol 6 (5) ◽  
pp. 63-70
Author(s):  
I. Borisov ◽  
A. Stronin
Keyword(s):  
Ball Mill ◽  
Mechanical Energy ◽  
Chemical Properties ◽  
Grinding Process ◽  
Fine Grinding ◽  
Grinding Media ◽  
Physical And Chemical ◽  
Selection Of ◽  
Rational Composition ◽  
And Chemical Properties

The ball mill has an energy efficiency of no more than 3.5 % (taking into account the measures taken to intensify the process of grinding the material). This is due to the imperfection of the design of the grinding unit, which consists in the fact that it is impossible to completely convert the mechanical energy accumulated by the grinding load into grinding energy (i.e., energy directly spent on the destruction of material particles). Most of the stored energy is converted into heat, noise, and vibration. The existing directions of intensification of the grinding process are as follows: improvement of the design, internal equipment of the cement mill; changes in the physical and chemical properties of the grinding medium; improvement of the grinding scheme. The authors of this article work in the direction of improving the internal equipment, which is reflected in the scientifically based selection of the range of grinding media for the fine grinding chamber, since the rational composition of the grinding load can significantly reduce the energy consumption of the grinding process. The authors continue to study the possibility of using a two-ball loading in a fine grinding chamber. This article provides a brief overview of the different ranges of two-ball grinding loadings, which differ from each other only in the range of grinding media. The possibility of a significant increase in the productivity of the mill when replacing the traditional grinding load with a rational two-ball is shown

METHODS TO FIND COORDINATES OF OIL WELLS – CONTAMINATORS OF THE ENVIRONMENT

2019 ◽  
pp. 72-80
Author(s):  
Ya. M. Semchuk ◽  
H. D. Lialiuk-Viter ◽  
G. M. Kryvenko
Keyword(s):  
Chemical Properties ◽  
Field Research ◽  
Oil Wells ◽  
Subsurface Water ◽  
Main Method ◽  
Chemical Indicators ◽  
Natural Flow ◽  
Physical And Chemical ◽  
Selection Of ◽  
And Chemical Properties

We have analyzed methods that are used to locate oil wells which pollute subsurface water. The main method to find coordinates is to run indicators in a well. It has been found out that a substance which would be absent in natural water should be selected among the range of chemical indicators. The selection of certain dyes is determined by physical and chemical properties of aquifers in order to eliminate sorption and dispersion processes. Two types of field research are recommended. The first scheme involves putting of the indicator into the well under conditions of natural flow, and the second scheme is the injection of substance into the well. The article points out the drawbacks of this method. It has also examined hydro chemical method to determine the coordinates which is based on the chemical analysis of samples taken from wells. We have also analyzed the method which uses hydrodynamic research to determine sources of contamination of aquifers. That is to disturb static equilibrium in the aquifer by intensive sample taking from the well which is the contamination source.

scholarly journals Review on Silver Nanoparticles as a Novel Class of Antibacterial Solutions

2021 ◽  
Vol 11 (3) ◽  
pp. 1120
Author(s):  
Corina Michaela Crisan ◽  
Teodora Mocan ◽  
Meda Manolea ◽  
Lavinia Iulia Lasca ◽  
Flaviu-Alexandru Tăbăran ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Chemical Properties ◽  
Synthesis And Characterization ◽  
Physical And Chemical Properties ◽  
Future Prospects ◽  
Characterization Methods ◽  
Antimicrobial Efficiency ◽  
Physical And Chemical ◽  
Selection Of ◽  
And Chemical Properties

Nanomaterials represent a promising novel class of materials to be used as antibacterial solutions. Inhomogeneity of synthesis and characterization methods, as well as resulting variate physical and chemical properties make selection of proper nanostructure difficult when designing antimicrobial experiments. Present study focuses on the already existing evidence regarding silver nanoparticles and their antibacterial applications, with focus on various modulatory factors of reported antimicrobial efficiency. Present paper focuses on synthesis and characterization methods, factors modulating antibacterial efficiency, laboratory quantification procedures, as well as up–to-date knowledge on mechanisms of antibacterial action for silver nanoparticles. Moreover, challenges and future prospects for antimicrobial applications of silver nanoparticles are reviewed and discussed.

scholarly journals Transformation of the energy state of the molecular structure of coal in the process of metamorphism

2018 ◽  
Vol 27 (1) ◽  
pp. 30-34 ◽  
Author(s):  
K. A. Bezruchko ◽  
L. I. Pymonenko ◽  
A. V. Burchak ◽  
D. A. Suvorov
Keyword(s):  
Molecular Structure ◽  
Energy State ◽  
Mechanical Energy ◽  
Chemical Properties ◽  
Quantum Mechanical ◽  
Fractal Approach ◽  
Structure Changes ◽  
Physical And Chemical ◽  
Quantum Mechanical Energy ◽  
And Chemical Properties

This article discusses processes of rock-mass geothermal and geomechanical energy transfer on the nanolevel and describes different mechanisms of potential energy absorption, distribution and usage by the molecular structure of the coal substance. We show that mechanical and thermal energies in the molecular structure of the coal substance are transformed into quantum-mechanical energy which feeds the structural transformations and generation processes in the substance. At the nanolevel, the energy inflow transforms the atomic-molecular structure, changes the physical and chemical properties of the coal and may cause fluid (including methane) emission. The availability of a general solution for energetic problems of different hierarchical levels is evidence of the possibility of using a fractal approach for researching the energy re-distribution in the system.

scholarly journals Selection of plum cultivars for subtropical regions

2018 ◽  
Vol 48 (11) ◽  
Author(s):  
Rafael Pio ◽  
Daniela da Hora Farias ◽  
Flávio Gabriel Bianchini ◽  
Pedro Maranha Peche ◽  
Rayane Barcelos Bisi
Keyword(s):  
Chemical Properties ◽  
Fruit Tree ◽  
The State ◽  
Physical And Chemical Properties ◽  
Rio Grande Do Sul ◽  
Physical And Chemical ◽  
Fruit Mass ◽  
Selection Of ◽  
And Chemical Properties

ABSTRACT: Plum growing is widespread in temperate zones. In Brazil, the exploitation of this fruit tree is extended from the colder regions of the state of Rio Grande do Sul to the south of the state of Minas Gerais. However, cultivars exploited at subtropical regions are scarce due to competition. The present study aimed to select productive cultivars of plums adapted to Brazilian subtropical conditions. In this respect, the plum cultivars ‘Fla 87-7’, ‘Gema de Ouro’, ‘Grancoure’, ‘Harry Pickstone’, ‘Januária’, ‘Santa Rosa’ and ‘Satsuma’ were grafted on the ‘Okinawa’ rootstock ‘and evaluated by two cycles in the municipality of Lavras, MG, Brazil. The phenological development, physical and chemical properties of fruits, average number of fruits per plant, average fruit mass and estimated yield were evaluated for each cultivar. It is concluded that plum cultivars ‘Januária’ and ‘Grancoure’ are the most promising for subtropical regions, mainly due to the volume of produced fruits and the quality of fruits.

scholarly journals Synthesis and study of the properties of derivatives 4-phenyl-5-(1H-pyrrol-2-yl)-4H-1,2,4-triazole-3-thiols

2018 ◽  
pp. 59-66
Author(s):  
A. S. Gotsulya ◽  
D. P. Verba ◽  
O. I. Panasenko ◽  
Ye. G. Knysh
Keyword(s):  
Heterocyclic System ◽  
Chemical Properties ◽  
Physico Chemical ◽  
Methods Of Synthesis ◽  
Interesting Object ◽  
Physical And Chemical ◽  
Derivatives Of ◽  
Selection Of ◽  
Base Structure ◽  
And Chemical Properties

The successful use of drugs, derivatives of 1,2,4-triazole, creates the conditionsfor the production and investigation of properties of new derivatives of this heterocyclic system. The aim of this work was synthesis and study of physical and chemical properties of new derivatives of 1,2,4-triazole-3-thiol containing synthon of pyrrole. The object of the study was a 4-phenyl-5-(pyrrol-2-yl)-1,2,4-triazole-3-ylthio-R-carbothioamides. To achieve this goal it was necessary to solve following tasks: to conduct the selection of the optimum base structure to determine the most efficient way of chemical modification of the precursor of targeted synthesis, to carry out selection of necessary methods of synthesis, to investigate the physico-chemical properties and to set the structure of the obtained compounds. The synthesis of target products of the reaction was carried out using as starting material pyrrole, which with using the form non-catalytic form of reaction of the Fridel-Crafts was transformed into 2,2,2-trichloro-1-(pyrrol-2-yl), ethanol. The resulting material in the result of reaction of hydrazinolysis was converted into the pyrrol-2-carbohydrazide. The obtained intermediate product was used in the reaction of nucleophilic joining of phenylisothiocyanate with subsequent intramolecular alkaline heterocyclization. Synthesized thiol was used in the reaction of alkylation. The structure of the obtained substances are confirmed by using elemental analysis, 1H-NMR-spectroscopy, and their individuality – chromatographic methods of analysis. The resulting substances are an interesting object for further studies, especially biological activity.

Study on the Conservation and Restoration of Marine Archaeological Porcelains - A Instructive Case of Traditional Crafts from Yue Kiln

2021 ◽  
Vol 7 (5) ◽  
pp. 3777-3786
Author(s):  
Tao Ma ◽  
Xiaodan Liu ◽  
Haiyan Zhu ◽  
Dan Yang ◽  
Zhijun Pan
Keyword(s):  
Chemical Properties ◽  
Practical Work ◽  
Salting Out ◽  
Production Methods ◽  
Repair Materials ◽  
Materials Used ◽  
Physical And Chemical ◽  
Instructive Case ◽  
Selection Of ◽  
And Chemical Properties

It is generally acknowledged that porcelains, among portable antiquities, boast relatively stable physical and chemical properties. However, marine archaeological porcelains are likely to suffer from deterioration such as salting out, attachment and corrosion due to the complicated burial environments. In the course of conservation and restoration, some natural diseases are easily mistaken for production defects. In order to preserve as much historical information about the antiquities as possible during the clean — up process, we systematically examined traditional porcelain production methods used at the Yue kiln, and conducted further research on typical production flaws that can easily be confused with the natural diseases. Based on these traditional methods and compositional characteristics of porcelains, we provide some guidance on the selection of clean —up methods and repair materials used for porcelains. From the perspective of identifiability and ageing resistance, this paper focuses on discussing the restoration scale of porcelains exhibited in museums. Based on our practical work, we discuss some problems that should be noticed in restoration and also provide an outlook for the future practical work and research.

Compressor and Throttle Characteristics for Models

2013 ◽  
Vol 404 ◽  
pp. 200-206 ◽  
Author(s):  
Lukas Smolarik ◽  
Dusan Mudroncik ◽  
Milan Strbo
Keyword(s):  
Mass Flow ◽  
Mechanical Energy ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Gas Composition ◽  
Compressor Design ◽  
Compressor Map ◽  
Physical And Chemical ◽  
Characteristic Mass ◽  
And Chemical Properties

Turbocharger is a device used for compression of gases of different features. I tis a conversion of kinetic energy or mechanical energy into pressure. Compressed media can be vary from pure gases such as hydrogen, oxygen, noble gases to the gas mixtures such as air, a mixture, of hydrogen and others. Gas composition is very important because of its physical and chemical properties depends on many parameters of compressor design [. The basis of modelling surge dynamics of centrifugal compressors is Greitzerov nonlinear model. This article is getting the gear characteristics of the mass flow and pressure increase passing compression system. Another challenge is getting the throttle characteristic mass flow and pressure drop on the throttling valve. These characteristics are necessary for modelling the dynamic model of a centrifugal compressor according Greitzer (1976). For getting these characteristics, it is necessary to know the data of the measurements. Data can be extracted from a manufacturer. One of the most important graphs is compressor characteristic, known as the compressor map.

Statistical criteria of stellar population types

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska
Keyword(s):  
Stellar Population ◽  
Chemical Properties ◽  
Spectrophotometric Study ◽  
Physical And Chemical Properties ◽  
Population Type ◽  
The Galaxy ◽  
Distribution Parameters ◽  
Physical And Chemical ◽  
Statistical Criteria ◽  
And Chemical Properties

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.

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