scholarly journals Mathematical Modeling of Impact of Possible Shock Dynamic Loads on the Modern Composite Materials

2019 ◽  
Vol 224 ◽  
pp. 02012
Author(s):  
Eugenе Sosenushkin ◽  
Oksana Ivanova ◽  
Elena Yanovskaya ◽  
Yuliya Vinogradova
Keyword(s):  
Composite Materials ◽  
Friction Force ◽  
Equations Of Motion ◽  
Elastic Fiber ◽  
Dynamic Loads ◽  
Friction Forces ◽  
Absolute Value ◽  
A Value ◽  
The Absolute ◽  
The Impact

In this paper, we study the dynamic processes in materials reinforced with fibers, that can be represented as composite rods. There has been developed a mathematical model of wave propagation under the impact of a shock pulse in semi-infinite composite rods. It is believed that the considered composite rod consists of two layers formed by simpler rods of different isotropic materials with different mechanical properties. The cross sections of such rods are considered to be constant and identical. When such composite materials are impacted by dynamic loads, a significant part of the energy is dissipated due to the presence of friction forces between the contact surfaces of the rods. In this regard, we study the propagation of waves in an elastic fiber-rod, the layers of which interact according to Coulomb law of dry friction. The case of instantaneous excitation of rods by step pulses is investigated. The blow is applied to a rod made of a harder material. In the absence of slippage, the friction force gets a value not exceeding the absolute value of the limit. In the absence of slippage, the friction force takes a value not exceeding the absolute value of the limit. Let us consider the value of the friction force constant. Normal stresses and velocities satisfy the equations of motion and Hooke’s law. The problem statement results in the solution of inhomogeneous wave equations by the method of characteristics in different domains, which are the lines of discontinuities of the solution. Solutions are found in all constructed domains. On the basis of the analysis of the obtained solution, qualitative conclusions are made and curves are constructed according to the obtained ratios. From the found analytical solution of the problem it is possible to obtain ratios for stresses and strain rates in composite rods and composite materials.

scholarly journals The Role of Environmental Tax in Alleviating the Impact of Environmental Pollution on Residents’ Happiness in China

2019 ◽  
Vol 16 (22) ◽  
pp. 4574 ◽  
Author(s):  
Yu Liu ◽  
Rong-Lin Li ◽  
Yang Song ◽  
Zhi-Jiang Zhang
Keyword(s):  
Water Pollution ◽  
Environmental Pollution ◽  
Regression Coefficient ◽  
General Social Survey ◽  
Environmental Tax ◽  
Absolute Value ◽  
Chow Test ◽  
The Absolute ◽  
The Government ◽  
The Impact

Background: Environmental tax has been implemented by the government in response to the demands of the residents to control environmental pollution. However, a tax has a wide effect on many interacting aspects of the society. It remains unknown whether enacting an environmental tax for the government can improve the residents’ happiness. This study aimed to examine the impact of air and water pollution on residents’ happiness and evaluate whether an environmental tax can alleviate the impact of air and water pollution on residents’ happiness. Methods: Based on the 2015 Chinese General Social Survey Data, 28 provinces in China were divided into two categories according to their environmental tax rates: baseline-tax areas (n = 13) and high-tax areas (n = 15). The ordered probit model was used to analyze the impact of air and water pollution on the residents’ happiness in baseline-tax areas and high-tax areas, respectively. The Chow Test was used to test whether the impact of environmental pollution on happiness was different between baseline-tax areas and high-tax areas. Results: The impact of air pollution on residents’ happiness was statistically significant in the baseline-tax areas (coefficient −0.162, 95% confidence interval (CI) −0.239, −0.086, p < 0.001), but the significance was weakened in the high-tax areas (coefficient −0.030, 95% CI −0.060, 0.000, p = 0.051). The Chow Test showed that the absolute value of the regression coefficient in the baseline-tax areas was significantly higher than the value in the high-tax areas (F = 12.712, p < 0.001). Similarly, the impact of water pollution on residents’ happiness was statistically significant (coefficient −0.264, 95% CI −0.353, −0.174, p < 0.001) in the baseline-tax areas and in the high-tax areas (coefficient −0.063, 95% CI −0.091, −0.035, p < 0.001), but the Chow Test showed that the absolute value of the regression coefficient in the baseline-tax areas was significantly higher than the value in the high-tax areas (F = 13.758, p < 0.001). Conclusions: Both air and water pollution impair residents’ happiness. The present study shows for the first time that enacting an environmental tax significantly alleviates the negative effect of air and water pollution on residents’ happiness. The findings of the present study provide empirical evidence for the government to levy environmental tax.

AN ABSOLUTE MEASUREMENT OF THE ACCELERATION DUE TO GRAVITY AT OTTAWA

1960 ◽  
Vol 38 (6) ◽  
pp. 824-852 ◽  
Author(s):  
H. Preston-Thomas ◽  
L. G. Turnbull ◽  
E. Green ◽  
T. M. Dauphinee ◽  
S. N. Kalra
Keyword(s):  
Stainless Steel ◽  
Discrete Time ◽  
Absolute Measurement ◽  
Absolute Gravity ◽  
Time Intervals ◽  
Absolute Value ◽  
Gravity Station ◽  
A Value ◽  
The Absolute

An apparatus for determining the absolute value of gravity by measuring the distances through which a rule falls in discrete time intervals is described. From the data associated with 64 drops with two non-magnetic stainless steel rules in vacuum, a value of g at the absolute gravity station at Ottawa of 980.6132 cm sec−2 with a possible error of ± 0.0015 cm sec−2 has been obtained. This value is 13.7 ± 2.0 milligal less than the Potsdam value at that position.

Measuring the Impact of Enterprise Resource Planning (ERP) Systems on Earnings Management

2010 ◽  
Vol 7 (1) ◽  
pp. 47-71 ◽  
Author(s):  
John J. Morris ◽  
Indrarini Laksmana
Keyword(s):  
Earnings Management ◽  
Enterprise Resource Planning ◽  
Resource Planning ◽  
Discretionary Accruals ◽  
Control Group ◽  
Erp Systems ◽  
Absolute Value ◽  
The Absolute ◽  
The Impact

ABSTRACT: This study examines the impact of ERP systems on earnings management. We use the absolute value of discretionary accruals as a proxy for earnings management, comparing levels for 143 firms in 32 industry groups that implemented ERP systems between 1994 and 2003 to levels for a control group. We find that over a ten-year period surrounding the implementation date, ERP implementers show a significant decrease in the absolute value of total discretionary accruals, while the control group does not. We further find that short-term discretionary accruals are driving the results, while long-term discretionary accruals show no significant change for either group.

scholarly journals Impact of Friction on the Uniaxial Soil Sample Compression Process

2017 ◽  
Vol 21 (2) ◽  
pp. 49-58 ◽  
Author(s):  
Dariusz Błażejczak ◽  
Rafał Nowowiejski ◽  
Jan B. Dawidowski
Keyword(s):  
Friction Force ◽  
Solid Phase ◽  
Solid Particles ◽  
Carbonate Content ◽  
Dry Density ◽  
Cylinder Wall ◽  
Friction Forces ◽  
Soil Material ◽  
Sample Height ◽  
The Impact

AbstractThe objective of the research was to determine the impact of the friction force between the cylinder wall and soil on the soil compaction resistance in relation to the sample height and diameter of the compaction plate. Samples with the diameter of (D) 100 mm and heights (H) of 30, 50 or 100 mm made of of soil material collected from subsoil of the selected plastic soils were used. The soil material wasidentified by the following properties: the granulation type, density of the solid phase, humus and calcium carbonate content, reaction, plastic and liquid limit. Properties of the samples were described with moisture, dry density of solid particles, porosity of aeration, plastic degree and saturation. The samples were loaded with plates of varied diameters (dA: 20; 30; 50; 70; 80; 90 and 98 mm) measuring at the same time forces on the main plate (FA) and the bottom one (FB) with the fixed diameter (dB=98 mm). The registered relationships between the forces FA and FB and plate sinkage (samples deformation) were used for determination of the impact of external friction forces (between the cylinder wall and soil) on the compression resistance of soils. It was found out that the participation of the friction force in relation to the height of samples and plate diameter varied from 0 to ca. 70%. It was proved that one may avoid the impact of the plate diameter dA on the measurement of force FA, when the relation dA/D, for samples with the heights of H30 and H50, is respectively within 0.5 ≤ dA/D < 0.8 and 0.5 ≤ dA/D < 0.7.

ERP Systems and Earnings Quality: The Impact of Dominant Shareholdings in China

2016 ◽  
Vol 13 (2) ◽  
pp. 49-69
Author(s):  
Songsheng Chen ◽  
Ling Harris ◽  
Jiao Lai ◽  
Wenying Li
Keyword(s):  
Financial Reporting ◽  
Earnings Quality ◽  
Discretionary Accruals ◽  
Erp Systems ◽  
Absolute Value ◽  
Listed Firms ◽  
Enterprise Resources Planning ◽  
Post Test ◽  
The Absolute ◽  
The Impact

ABSTRACT Using a sample of ERP adopters among Chinese publicly listed firms and a one-group pre- and post-test design, this study examines the impact of dominant shareholdings on the relationship between Enterprise Resources Planning (ERP) systems and earnings quality. We use the absolute value of discretionary accruals as a proxy for earnings quality. We predict and find that as the dominant shareholdings increase, Chinese firms show a decrease in the absolute value of total discretionary accruals after ERP implementations. Furthermore, we find that after ERP implementations, discretionary short-term accruals decrease with higher dominant shareholdings, while discretionary long-term accruals increase with higher dominant shareholdings. Our study contributes to research and practice by documenting that dominant shareholdings in China can influence the impact of ERP implementations on earnings quality, suggesting that dominant shareholdings may induce dominant shareholders' self-serving incentives to influence firms' financial reporting via ERP implementations.

scholarly journals More than just slippery: the impact of biofilm on the attachment of non-sessile freshwater mayfly larvae

2014 ◽  
Vol 11 (92) ◽  
pp. 20130989 ◽  
Author(s):  
Petra Ditsche ◽  
Jan Michels ◽  
Alexander Kovalev ◽  
Jochen Koop ◽  
Stanislav Gorb
Keyword(s):  
Friction Force ◽  
Aquatic Organisms ◽  
Friction Forces ◽  
Functional Aspects ◽  
Surface Irregularities ◽  
The Subject ◽  
Terrestrial Insects ◽  
Attachment Ability ◽  
The Impact

While terrestrial insects can usually attach directly to a substrate, for aquatic insects the situation is more complicated owing to the presence of a biofilm on the primary substrates. This important fact has been neither the subject of investigation nor commonly taken into account in the interpretation of functional aspects of attachment in mobile freshwater animals. In this study, we investigate the impact of a biofilm on the attachment of living mayfly larvae. We performed in vivo attachment experiments in a flow channel using different substrates with defined surface roughness. Additionally, we measured friction forces directly generated by dissected tarsal claws on the same substrates. On substrates with smooth or slightly rough surfaces, which have little or no surface irregularities large enough for the claws to grasp, the presence of a biofilm significantly increases the friction force of claws. Consequently, larvae can endure higher flow velocities on these smooth substrates. The opposite effect takes place on rough substrates, where the friction force of claws decreases in the presence of a biofilm. Consequently, a biofilm is a critical ecological structure for these larvae, and other aquatic organisms, not only as a food source but also as a factor influencing attachment ability.

Spatial Impact of a Slender Beam

2002 ◽  
Author(s):  
Horatiu Barbulescu ◽  
Dan B. Marghitu ◽  
Uday Vaidya
Keyword(s):  
Composite Materials ◽  
Incident Angle ◽  
Contact Point ◽  
Equations Of Motion ◽  
Coefficient Of Restitution ◽  
Tangential Component ◽  
Sliding Direction ◽  
Generalized Momentum ◽  
Separation Force ◽  
The Impact

In this paper, the dynamics of the spatial impact of a slender beam is analyzed. The equations of motion are calculated using Kane’s impact method. The generalized momentum and generalized impulse of the beam are considered to find the equations of motion of the beam. The frictional phenomenon at the contact point is analyzed. For the case of impact without slipping, it is used the assumption that the tangential component of the velocity of separation is null. In the case with slipping, the tangential impulse (at the plane of impact) is computed. The sliding direction after impact is calculated. A simulation of the impact of beam with a surface is developed and the velocity of separation, force of impact and kinetic energy of the beam after impact are studied for different incident angles of the beam. The incident angle is varied from 0° to 57°. The results are function of the incident angle of impact. The results can be used to calculate the coefficient of restitution and friction for composite materials.

POSSIBILITY TO ENSURE THE TECHNICAL EFFICIENCY OF THE VERTICAL SPINDLE COTTON PICKER

2021 ◽  
Vol 4 (1) ◽  
pp. 42-49
Author(s):  
M. Shoumarova ◽  
◽  
T. Abdillaev ◽  
Sh.A. Yusupov
Keyword(s):  
Technical Efficiency ◽  
Friction Force ◽  
Angular Speed ◽  
Economic Conditions ◽  
Friction Forces ◽  
Cotton Picker ◽  
Cotton Picking ◽  
Drive Belt ◽  
The Absolute

In order for the use of the vertical-spindle cotton picker, created in Uzbekistan, to be economically effective, it is necessary, first of all, to increase its completeness of harvest. This indicator depends on many factors. However, the most important factor is that the spindle friction drive function is inadequate. Friction forces between the friction drive belts and the spindle roller determine its tagging capacity. The magnitude of the friction force depends on the pressure of the belts on the roller, which in turn depends on the tension of the drive belts. The article analyzes how much the tension of the drive belts in economic conditions meets the requirements.Key words:completeness of cotton picking by the apparatus; friction drive; belt tension; traction ability; direction and magnitude of the absolute speed of the spindle tooth; moment of power; variability of the angular speed of the spindle; gripping power of the tooth

Prognostic value of absolute monocyte count in chronic lymphocytic leukaemia

2015 ◽  
Vol 156 (15) ◽  
pp. 592-597
Author(s):  
László Szerafin ◽  
János Jakó ◽  
Ferenc Riskó
Keyword(s):  
Chronic Lymphocytic Leukaemia ◽  
Prognostic Value ◽  
Lymphocytic Leukaemia ◽  
Treatment Time ◽  
Monocyte Count ◽  
Time To Treatment ◽  
Causes Of Mortality ◽  
The Absolute ◽  
The Impact ◽  
Overal Survival

Introduction: The low peripheral absolute lymphocyte and high monocyte count have been reported to correlate with poor clinical outcome in various lymphomas and other cancers. However, a few data known about the prognostic value of absolute monocyte count in chronic lymphocytic leukaemia. Aim: The aim of the authors was to investigate the impact of absolute monocyte count measured at the time of diagnosis in patients with chronic lymphocytic leukaemia on the time to treatment and overal survival. Method: Between January 1, 2005 and December 31, 2012, 223 patients with newly-diagnosed chronic lymphocytic leukaemia were included. The rate of patients needing treatment, time to treatment, overal survival and causes of mortality based on Rai stages, CD38, ZAP-70 positivity and absolute monocyte count were analyzed. Results: Therapy was necessary in 21.1%, 57.4%, 88.9%, 88.9% and 100% of patients in Rai stage 0, I, II, III an IV, respectively; in 61.9% and 60.8% of patients exhibiting CD38 and ZAP-70 positivity, respectively; and in 76.9%, 21.2% and 66.2% of patients if the absolute monocyte count was <0.25 G/l, between 0.25–0.75 G/l and >0.75 G/l, respectively. The median time to treatment and the median overal survival were 19.5, 65, and 35.5 months; and 41.5, 65, and 49.5 months according to the three groups of monocyte counts. The relative risk of beginning the therapy was 1.62 (p<0.01) in patients with absolute monocyte count <0.25 G/l or >0.75 G/l, as compared to those with 0.25–0.75 G/l, and the risk of overal survival was 2.41 (p<0.01) in patients with absolute monocyte count lower than 0.25 G/l as compared to those with higher than 0.25 G/l. The relative risks remained significant in Rai 0 patients, too. The leading causes of mortality were infections (41.7%) and the chronic lymphocytic leukaemia (58.3%) in patients with low monocyte count, while tumours (25.9–35.3%) and other events (48.1 and11.8%) occurred in patients with medium or high monocyte counts. Conclusions: Patients with low and high monocyte counts had a shorter time to treatment compared to patients who belonged to the intermediate monocyte count group. The low absolute monocyte count was associated with increased mortality caused by infectious complications and chronic lymphocytic leukaemia. The absolute monocyte count may give additional prognostic information in Rai stage 0, too. Orv. Hetil., 2015, 156(15), 592–597.

Influence of social networks on business processes’ development

2020 ◽  
Vol 19 (12) ◽  
pp. 2225-2252
Author(s):  
E.V. Popov ◽  
V.L. Simonova ◽  
O.V. Komarova ◽  
S.S. Kaigorodova
Keyword(s):  
Social Networks ◽  
Social Media ◽  
Business Models ◽  
Business Processes ◽  
Digital Economy ◽  
Theoretical Understanding ◽  
Sales Channels ◽  
A Value ◽  
The Impact

Subject. The emergence of new ways of interaction between sellers and buyers, the formation of new sales channels and product promotion based on the use of digital economy tools is at the heart of improving the business processes. Social networks became a tool for development; their rapid growth necessitates theoretical understanding and identification of potential application in enterprise's business process digitalization. Objectives. We explore the role of social media in the digitalization of business processes, systematize the impact of social networks on business processes of enterprises in the digital economy. Methods. The theoretical and methodological analysis of social networks as a tool for digitalization of company's business processes rests on the content analysis of domestic and foreign scientific studies, comparison, generalization and systematization. Results. We highlight the key effects of the impact of social networks on the business processes of the company; show that the digitalization of business processes should be considered in the context of a value-based approach, aimed at creating a value through the algorithmization of company operations. We determine that social networks are one of the most important tools for digitalization of company's business processes, as they have a high organizational and management potential. We also systematize the effects of social media on company's business processes. Conclusions. We present theoretical provisions of the impact of social networks on business processes of enterprises, which will enable to model and organize ideas about the development of digital ecosystems and the formation of business models.

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