scholarly journals The use of nanosized additives in the modification of brick loam

2021 ◽  
Vol 274 ◽  
pp. 04005
Author(s):  
Andrey Bogdanov ◽  
Azat Mavlyuberdinov ◽  
Evgeniya Nurieva
Keyword(s):  
Amorphous Phase ◽  
Control Sample ◽  
Strength Properties ◽  
Strength Characteristics ◽  
Positive Effect ◽  
Nanosized Silica

The effect of nanosized additives on the strength properties of ceramics based on fusible brick loam of the Klyuchischenskoye deposit has been studied. In general, all nanosized additives selected for the study had a positive effect on the strength properties of ceramics. The greatest increase in strength, when using nanosized silica ash Laksil 30, was 70 %, in relation to the control sample. When using silica ash, an increase in the content of the amorphous phase in the shard after firing is noted against the background of a decrease in its porosity, which causes an increase in strength characteristics. The nature of the destruction of the samples also differed. The destruction of the control sample was accompanied by the formation and gradual opening of cracks. The destruction of the modified samples was more fragile in comparison with the control. Thus, the effectiveness of nanosized additives on the strength properties of ceramics is shown.

scholarly journals Density, hardness and strength properties of densified fir and aspen woods pretreated with water repellents

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Hüseyin Pelit ◽  
Fatih Emiroglu
Keyword(s):  
Compression Ratio ◽  
Bending Strength ◽  
Linseed Oil ◽  
Vacuum Treatment ◽  
Strength Properties ◽  
Aspen Wood ◽  
Positive Effect ◽  
Water Repellents ◽  
Impregnated Wood ◽  
Compression Temperature

AbstractIn this study, the effect of thermo-mechanical densification on the density, hardness, compression strength, bending strength (MOR), and modulus of elasticity (MOE) of fir and aspen wood pretreated with water repellents was analyzed. Wood specimens were impregnated with paraffin, linseed oil and styrene after pre-vacuum treatment. Then, the impregnated wood specimens were densified with compression ratios of 20 and 40%, and at 120, 150 and 180 °C. The results indicated that the density, hardness and strength properties of the all densified specimens (untreated and impregnated) increased depending on the compression ratio and temperature. For all tested properties, higher increases were obtained in the paraffin and styrene pretreated specimens compared to untreated samples. However, the increase rates in linseed oil pretreated specimens were generally lower than untreated specimens. Regarding water repellents the most successful results in all tested properties were determined in styrene pretreated specimens. The density, hardness and strength properties of all specimens increased with the increase in compression ratio. On the other hand, the increase in the compression temperature negatively affects the properties of untreated and linseed oil pretreated specimens, while having a generally positive effect on the properties of paraffin pretreated specimens. However, all tested properties of styrene pretreated specimens have increased significantly due to the increase in compression temperature. The increasing strength properties of wood as a result of densification have increased much more with paraffin and especially styrene pretreatment. These combinations can be considered as an important potential for applications that require more hardness and strength.

General concept of determining the parameters of non-mining walls of ultra-deep diamond deposits development open pits

2021 ◽  
pp. 48-53
Author(s):  
I. V. Zyryanov ◽  
A. N. Akishev ◽  
I. B. Bokiy ◽  
N. M. Sherstyuk
Keyword(s):  
Rock Mass ◽  
Structural Relaxation ◽  
Slope Angle ◽  
Field Tests ◽  
Friction Angle ◽  
Strength Properties ◽  
Strength Characteristics ◽  
Open Pit ◽  
Open Pit Mining ◽  
Relaxation Coefficient

A specific feature of open pit mining of diamond deposits in Western Yakutia is the construction of the open pits in the zone of negative ambient temperatures, which includes thick permafrost rock mass, and which is at the same time complicated by the influence of cryogenic processes on deformation of pit wall benches. The paper presents the comparative analysis of strength characteristics in frozen and thawed rocks, stability of benches during mining, the general geomechanical approach to the determination of parameters of non-mining walls of the ultra-deep open pit diamond mines, and the parameters of nonmining walls and benches. Optimization of open pit wall configuration should primarily be based on the maximum utilization of the strength properties of frozen rocks in combination with the development of new approaches, calculation schemes and methods for assessing stability of open pit walls and benches of unconventional design, including the non-mining vertical benches. The main design characteristic that determines the parameters of open pit walls is the structural tectonic relaxation coefficient, which specifies the calculated value of cohesion in rock mass. For the diamond deposits, the values of the structural relaxation coefficient were obtained in a series of field tests and back calculations. Full-scale tests were carried out both during exploration operations in underground mines and in open pits. The accuracy of determining the values of the structural relaxation coefficient in the range of 0.085–0.11 is confirmed by the parameters of non-mining walls in an open pit mine 385–640 m deep, with overall slope angles of 38–55° and a steeper H 0.35–0.5 lower part having the slope angle of up to 70° with average strength characteristics of 7.85–11.84 MPa and the internal friction angle of 28.1–37.4°. Using the natural load-bearing capacity of rock mass to the full advantage, which the values of the structural relaxation coefficient of deposits show, allows optimization of open pit wall slope design and minimization of stripping operations.

Weldability: Effect of Alloying Element Sc, Mn, and Zr on Alloys of the Al-Mg-Sc-Mn-Zr System

2019 ◽  
Author(s):  
V. I. Lukin
Keyword(s):  
Aluminum Alloys ◽  
Practical Importance ◽  
Strength Properties ◽  
Strength Characteristics ◽  
Mg Alloy ◽  
Alloying Element ◽  
Processing Properties ◽  
Alloys Of The Al ◽  
Effect Of Alloying

Scandium in aluminum alloys behaves as the most efficient modifier of the structure of the material and as an agent suppressing recrystallization. This unique behavior of scandium in alloys of the Al-Mg system greatly increases the strength characteristics, whilst retaining on a higher level the ductility and processing properties of deformed semi-finished products. This article describes the effect of complex alloying the Al-6.3% Mg alloy with scandium, manganese and zirconium on the weldability and strength properties of the material is of considerable scientific and practical importance.Investigations.

The Effect of Corporate Sustainability Practices on Financial Performance

2019 ◽  
pp. 52-70 ◽  
Author(s):  
Ibrahim Yasar Gok ◽  
Ozan Ozdemir ◽  
Bugra Unlu
Keyword(s):  
Financial Performance ◽  
Manufacturing Industry ◽  
Corporate Sustainability ◽  
Control Sample ◽  
Corporate Financial Performance ◽  
Performance Variables ◽  
Sustainability Practices ◽  
The Impact ◽  
Positive Effect ◽  
Better Than

In this chapter, the impact of corporate sustainability practices (CSP) on corporate financial performance (CFP) is investigated in terms of Turkish manufacturing industry. In this context, 16 sustainable companies vs. 21 control companies in 2016 and 16 sustainable companies vs. 24 control companies in 2017 are examined. Thirty-seven financial performance variables within seven groups are used, and non-parametric Mann-Whitney U test is applied. In 2016, four out of seven significant variables point out that sustainable companies perform better than control sample; however, in 2017, three out of four significant variables indicate the opposite. Therefore, the results are mixed, and it is concluded that implementing environmental, social, and governance (ESG) criteria do not have a noticeable positive effect on financial performances of manufacturing industry companies, at least in the short-term.

Influence Study of Plasticizer Compatibility on Strength Properties of Ethylene-Vinyl Acetate

2018 ◽  
Vol 935 ◽  
pp. 79-83
Author(s):  
A.N. Volotskoy ◽  
Yuriy V. Yurkin ◽  
V.V. Avdonin
Keyword(s):  
Mechanical Properties ◽  
Vinyl Acetate ◽  
Ethylene Vinyl Acetate ◽  
Dynamic Mechanical Properties ◽  
Strength Properties ◽  
Polymer Materials ◽  
Strength Characteristics ◽  
Actual Problem ◽  
Urgent Task ◽  
Wide Range

This research is devoted to the actual problem of the development of damping polymer materials which are effective in a wide range of temperatures and having satisfactory strength characteristics. There are many works devoted to the study of dynamic mechanical properties of filled composites, but most do not take into account the influence of plasticizer on the strength properties of the polymer, as they change its characteristics for the worse. In this respect, the study and comparison of the mechanical properties of the polymer base with the introduction of different types and concentrations of plasticizers is an urgent task. According to the received regularities it was possible to define the type, concentration and boundaries of the polarity of the plasticizer, which reduces the strength characteristics of ethylene-vinyl acetate to a lesser degree.

scholarly journals THE EFFECT OF CERAMIC WASTE AS COARSE AGGREGATE ON STRENGTH PROPERTIES OF CONCRETE

2017 ◽  
Vol 36 (3) ◽  
pp. 691-696
Author(s):  
EE Ikponmwosa ◽  
SO Ehikhuenmen
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Coarse Aggregate ◽  
Control Sample ◽  
Strength Properties ◽  
Waste Material ◽  
Partial Replacement ◽  
Replacement Level ◽  
Ceramic Waste ◽  
Curing Age

This paper reports the findings on an experimental investigation of the effect of partial replacement of coarse aggregate with ceramic waste on strength properties of concrete. Compressive strength tests were conducted using 150x150x150mm cube specimens, while tensile strength was investigated using 150x300mm cylinder specimens. Results of tests show that workability, density, compressive and flexural strength of concrete decreased with increase in ceramic waste content. The compressive strength at 90 days curing age for the control sample was 24.67 N/mm2. Compressive strength values at 90 days curing age for  25%, 50% and 75% replacement levels were 21.78 N/mm2, 19.85 N/mm2and 17.85 N/mm2 respectively. The decrease in density and strength was due to ceramic waste being lighter and more porous than normal coarse aggregate. Tensile strength of concrete with ceramic waste decline gradually from 8.39 N/mm2 to 6.13 N/mm2 for the control and 75% replacement samples respectively. This could be attributed to the water absorption capacity and external porcelain nature of the waste material. A production cost savings of 10.7% for 1:2:4 concrete mix was noted at 75% replacement level. This study concludes that ceramic waste could be used for both structural and non-structural works and recommends that beyond 75% replacement level, ceramic waste material should not be used in concrete structures where strength is the major consideration. http://dx.doi.org/10.4314/njt.v36i3.5

In Situ Test Study on Shear Strength Properties of Weathered Silty Mudstone

2010 ◽  
Vol 146-147 ◽  
pp. 10-13 ◽  
Author(s):  
Zhang Ming Li ◽  
Liang Liang Chen ◽  
Feng Wu ◽  
Ling Wan
Keyword(s):  
Shear Strength ◽  
Maximum Shear Stress ◽  
Strength Properties ◽  
Strength Characteristics ◽  
Shear Strength Parameters ◽  
Silty Mudstone ◽  
Normal Loading ◽  
Test Study ◽  
The Given

The shear strength characteristics of rock are very concerned in related underground construction. In this paper, in situ direct shear test for the weathered silty mudstone of the direct rock mass in a large section tunnel is carried out, the shear strength parameters are obtained, and some laws on the strength characteristics of this rock are got, such as that the displacement corresponds to the maximum shear stress under the given normal is decreased with increasing of normal loading number. This work provides a reference for the study of rock strength theory and its application.

scholarly journals Influence of climate warming on the strength characteristics of ice in the Ob Bay

2019 ◽  
Vol 59 (4) ◽  
pp. 539-545
Author(s):  
O. M. Andreev ◽  
D. V. Drabenko ◽  
R. A. Vinogradov ◽  
E. U. Orlova
Keyword(s):  
Climate Warming ◽  
Oil And Gas ◽  
Strength Properties ◽  
Water Area ◽  
Strength Characteristics ◽  
Ice Thickness ◽  
Empirical Formulas ◽  
The Russian Federation ◽  
Oil And Gas Companies ◽  
Further Development

The article presents results of investigation of the climate warming effects in the northern polar region of the Earth, in particular on some characteristics of ice in the northern part of the Ob Bay (the area of the most active economic activity of the Russian Federation in the last decade). It is determined that over the past 40 years, morphometric and strength characteristics of ice have significantly changed. Estimates of ice thickness obtained using simple empirical formulas (depending on the sum of the degree-days of frost) show that the ice thickness decreased here by an average of 10 15%. The strength characteristics of ice were analyzed for two periods: the maximum strength of ice (for this area it is March) and the maximum development of ice thickness (usually it is May). It was found that the strength properties of ice (bending and compression) for both periods decreased by 10-12%. Thus, in recent decades, under the influence of climate warming in the Ob Bay, the thickness and strength of the ice cover have significantly decreased. This circumstance will be favorable for further development of the considered water area by Russian oil and gas companies.

scholarly journals THE USE OF PULSE MODULATION AS A WAY TO IMPROVE THE STRENGTH CHARACTERISTICS OF PLASMA COATINGS

2021 ◽  
Author(s):  
A.M. Kadirmetov ◽  
◽  
V.N. Bukhtoyarov ◽  
V.A. Ivannikov ◽  
◽  
...  
Keyword(s):  
Wear Resistance ◽  
Strength Properties ◽  
Strength Characteristics ◽  
Plasma Process ◽  
Electrical Parameters ◽  
Pulse Modulation ◽  
Coat Ings ◽  
Machine Parts ◽  
Plasma Coatings

Currently, much attention is paid to improving the wear resistance of the sur-face of machine parts. It is possible to improve the quality of surfaces with the use of plasma coat-ings. However, these coatings do not always provide the necessary strength properties. The article considers one of the ways to improve the strength characteristics – the modulation of the electrical parameters of the plasma process.

scholarly journals Influence of Lime, Rice Husk Ash and Coconut Fibre on Strength Properties of Subgrade

2020 ◽  
Vol 9 (8) ◽  
pp. 767-772
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
Clayey Soil ◽  
Strength Properties ◽  
Strength Characteristics ◽  
Soil Stability ◽  
Dry Density ◽  
Subgrade Soil ◽  
Adjustment Strategies ◽  
Coconut Fibre

Soil stability is a significant criterion in the field of development, for soil which needs adequate steadiness, different adjustment strategies can be embraced. The entrenched methods of soil adjustment regularly utilize such establishing operators like cement. Substitution of solidifying substance with commercial or agriculture outcome is profoundly attractive. Rice husk ash is an extremely prospective agriculture dissipates as pozzolanic materials that bring about a prevalent property after joined with lime. Also, coconut fibre is well known for its durability and high resistance and gives well establishing results when combined with lime and rice husk ash. This study worked on the experimental investigation of clayey soil with admixtures like lime, rice husk ash and coconut fibre. This study included the calculation of properties of the soil as consistency limits and strength characteristics. Clay type of soil is used in this study. In view of compaction, expansion of lime, RHA and coconut fibre diminishes the dry density and expands the moisture content. From the perspective of strength characteristics and economical terms, expansion of 6% lime, 8 % RHA and 1 % coconut fibre are prescribed as ideal value for subgrade soil adjustment

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