Influence of quadrat characteristics on the evolution of the dispersion effect for fiber–water dispersions

2021 ◽  
pp. 004051752110642
Author(s):  
Yunlong Shi ◽  
Xiaoyu Guan ◽  
Xiaoming Qian
Keyword(s):  
Optimum Shape ◽  
Dispersion Effect ◽  
Obvious Effect ◽  
Point Distribution ◽  
Water Dispersion ◽  
Dispersion Effects ◽  
Good Measurement ◽  
Properties Of Materials ◽  
The Difference ◽  
Quadrat Analysis

Dispersing fibers in a water dispersion is an important issue for many fiber-based materials that significantly affects the mechanical and many other properties of materials. However, the measurement and assessment of the dispersion effect remains a significant challenge. In this study, we presented an image analysis method based on quadrat analysis from ecology and geography, transforming the issue of the dispersion effect into the statistics of point distribution. Furthermore, we changed the type of sampling and adjusted the shape, size and numbers of each quadrat to investigate its influences on the evaluation results. Our results showed that the area of one quadrat had a more obvious effect on the evaluation results compared to the number of quadrats. In addition, having a quadrat of an optimum shape enlarged the difference in various dispersion effects; the results of a square quadrat exhibited stably in both complete coverage and random sampling. Quadrat analysis realizes good measurement of dispersion states as a result of image processing and offers an assessment of the dispersion effect in a fiber–water dispersion.

scholarly journals The Role of Internal Control in Firms’ Coping with the Impact of the COVID-19 Pandemic: Evidence from China

2021 ◽  
Vol 13 (11) ◽  
pp. 6294
Author(s):  
Peiqing Zhu ◽  
Jianbo Song
Keyword(s):  
Internal Control ◽  
Manufacturing Industry ◽  
Firm Heterogeneity ◽  
Negative Impact ◽  
Risk Prevention ◽  
High Tech ◽  
Obvious Effect ◽  
The Difference ◽  
The Impact

Internal control plays a role in risk prevention for firms when dealing with serious emergencies, which ensures the sustainable development of firms during a crisis. Based on the rapid outbreak of COVID-19 in China, this paper empirically tests whether internal control alleviates the negative impact of the pandemic on firm performance. Using a sample of Chinese listed firms from the first quarter of 2019 to the third quarter of 2020 and employing the difference-in-difference (DID) method, we find that the firms with a higher quality of internal control achieve better financial performance during the pandemic period; the more serious the pandemic is, the more obvious effect internal control plays. Furthermore, we consider the industry heterogeneity and firm heterogeneity of the risk resistance effect of internal control. In the manufacturing industry, which is a “disaster zone” of the pandemic, and the non-high-tech industry with a low degree of digitization, internal control can play a more important role in firms’ performance. Moreover, for state-owned enterprises, and firms with strong financing constraints, the role of internal control is more prominent. The above results provide empirical evidence for the risk prevention function of internal control and shed new light on the measures for firms to resist emergencies in the future.

scholarly journals Simultaneous and Efficient Production of Furfural and Subsequent Glucose in MTHF/H2O Biphasic System via Parameter Regulation

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 557
Author(s):  
Shaolong Sun ◽  
Xuefei Cao ◽  
Huiling Li ◽  
Yingbo Zhu ◽  
Yijing Li ◽  
...  
Keyword(s):  
Glucose Production ◽  
Biphasic System ◽  
Efficient Production ◽  
Obvious Effect ◽  
Environment Friendly ◽  
H2so4 Concentration ◽  
Food Industries ◽  
The Difference ◽  
Temperature Time ◽  
Furfural Production

Efficient production of furfural from cornstalk in 2-Methyltetrahydrofuran/aqueous (MTHF/H2O) biphasic system via parameter regulation (e.g., VMTHF/VH2O, temperature, time, and H2SO4 concentration) was proposed. The resulting solid residues achieved from the different MTHF/H2O system conditions for furfural production were also to prepare glucose by adding cellulases to increase the high-value applications of cornstalk. A maximum furfural yield (68.1%) was obtained based on reaction condition (VMTHF:VH2O = 1:1, 170 °C, 60 min, 0.05 M H2SO4). Among these parameters, the concentration of H2SO4 had the most obvious effect on the furfural production. The glucose yields of the residues acquired from different MTHF/H2O processes were enhanced and then a maximum value of 78.9% based on the maximum furfural production conditions was observed. Single factor may not be sufficient to detail the difference in glucose production, and several factors affected the hydrolysis efficiency of the residues. Overall, the MTHF/H2O system effectively converted cornstalk into furfural and glucose via a simple and environment-friendly process, thus was an ideal manner for the food industries.

scholarly journals Dispersion analysis of the solid helical pulse-forming line

2015 ◽  
Vol 33 (3) ◽  
pp. 405-413 ◽  
Author(s):  
Langning Wang ◽  
Jinliang Liu
Keyword(s):  
Dispersion Curve ◽  
Pulse Width ◽  
Theoretical Calculations ◽  
Dispersion Analysis ◽  
Dispersion Theory ◽  
Dispersion Effect ◽  
Electric Length ◽  
Field Simulation ◽  
Dispersion Effects ◽  
Em Field

AbstractIn this paper, a solid helical pulse-forming line (HPFL) is described. The electromagnetic (EM) dispersion theory is used to calculate the important parameters of the HPFL based on tape helix model. Dispersion effects on the important EM parameters of HPFL, such as electric length and characteristic impedances, are analyzed. When Al2O3 ceramic is applied to be the dielectric in the HPFL, the pulse width of the HPFL is calculated nearly 50 ns only with the length of 305 mm. EM field simulation can draw the dispersion curve of the HPFL directly, which can describe the dispersion effect on the electric length of HPFL. Furthermore, the EM field simulation and experiments are carried out to verify the theoretical calculations of the pulse wide and characteristic impedances. Both simulation and experimental results can prove the EM analyses and calculations in this paper.

Methodology for Measurement of Density of Liquid Oxides

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Jan Hrbek ◽  
Bence Mészáros ◽  
Mykhaylo Paukov ◽  
Martin Kudláč
Keyword(s):  
High Temperature ◽  
Temperature Dependence ◽  
Extreme Conditions ◽  
Nuclear Accidents ◽  
System A ◽  
Different Temperatures ◽  
Density Values ◽  
Properties Of Materials ◽  
The Difference

Abstract Measurement of physical properties of materials in extreme conditions, such as high temperature, is limited by technological challenges. Nevertheless, modeling of several phenomena relies on the existence of experimental data for their validation. In this study, a method suitable for determination of density in a liquid phase at high temperature is proposed and tested on Al2O3–ZrO2 system. A methodology for acquiring the temperature dependence of density for radioactive materials is proposed and is aimed to refine severe nuclear accidents modeling. The oxide was melted in an induction furnace with a cold crucible. The measurement was based on evaluation of the volume of the melt at different temperatures, in a range from 2100 to 2400 °C. The densities of the oxide in the solid-state and the skull-layer were measured using a pycnometer. A temperature dependence of the density was established and the results were compared with literature. The difference between existing data and the measured values in this work was less than 5%. Thus, the proposed methodology provides reliable density values in extreme conditions.

Supporting Force Analysis of Oil Pads in Hydrostatic Rotary Table of Heavy Duty CNC Machine

2013 ◽  
Vol 655-657 ◽  
pp. 1267-1272
Author(s):  
Li Gang Cai ◽  
Xiao Shi ◽  
Yong Sheng Zhao
Keyword(s):  
Structural Deformation ◽  
Work Piece ◽  
Rotary Table ◽  
Heavy Duty ◽  
Cnc Machine ◽  
Point Distribution ◽  
Supporting Point ◽  
Heavy Work ◽  
The Difference ◽  
Supporting Force

According to the characteristics of constant flow and closed hydrostatic rotary table used in heavy duty CNC machine, in order to consider the interaction between structural deformation of worktable and the supporting force of oil pads, an iteration method between hydrostatic theory calculation and finite element method (FEM) is used to get the real supporting force of each oil pad at different carrying state. The result is compared with the situation which is not considering the deformation of worktable and the difference between them can be used to guide the design of hydrostatic oil pads. The optimal radius of supporting point of work piece is also achieved using this method, which can provide theory basis for supporting point distribution of heavy work piece.

scholarly journals Autosomal dominant erythrocytosis caused by increased sensitivity to erythropoietin

Blood ◽  
1991 ◽  
Vol 78 (11) ◽  
pp. 3066-3069 ◽  
Author(s):  
E Juvonen ◽  
E Ikkala ◽  
F Fyhrquist ◽  
T Ruutu
Keyword(s):  
Autosomal Dominant ◽  
Family Members ◽  
Calf Serum ◽  
Methyl Cellulose ◽  
Colony Growth ◽  
Erythroid Progenitors ◽  
Obvious Effect ◽  
Increased Sensitivity ◽  
The Difference

Abstract We describe here a family with autosomal dominant erythrocytosis. In in vitro cultures, performed using the methyl cellulose assay, the number of erythroid colonies was normal or marginally increased when a standard concentration of erythropoietin (Epo) was used, but at lower Epo concentrations, the investigated persons formed more colonies than the controls. The difference was generally greater the lower the Epo concentration became. Some erythroid colony growth was seen even in the absence of any added Epo (apart from the minute concentration found in fetal calf serum), a phenomenon not seen in the controls. This finding indicates that the erythrocytosis in this family is caused by hypersensitivity of erythroid progenitors to Epo. The serum Epo concentration was low or low normal in all of the investigated family members, which is in good accordance with hypersensitivity to Epo. The erythrocytosis has not had any obvious effect on the health or life- span of the affected individuals. Many of them have reached an advanced age, and one of the affected family members has won several Olympic gold medals and world championships in endurance sports.

Autosomal dominant erythrocytosis caused by increased sensitivity to erythropoietin

Blood ◽  
1991 ◽  
Vol 78 (11) ◽  
pp. 3066-3069 ◽  
Author(s):  
E Juvonen ◽  
E Ikkala ◽  
F Fyhrquist ◽  
T Ruutu
Keyword(s):  
Autosomal Dominant ◽  
Family Members ◽  
Calf Serum ◽  
Methyl Cellulose ◽  
Colony Growth ◽  
Erythroid Progenitors ◽  
Obvious Effect ◽  
Increased Sensitivity ◽  
The Difference

We describe here a family with autosomal dominant erythrocytosis. In in vitro cultures, performed using the methyl cellulose assay, the number of erythroid colonies was normal or marginally increased when a standard concentration of erythropoietin (Epo) was used, but at lower Epo concentrations, the investigated persons formed more colonies than the controls. The difference was generally greater the lower the Epo concentration became. Some erythroid colony growth was seen even in the absence of any added Epo (apart from the minute concentration found in fetal calf serum), a phenomenon not seen in the controls. This finding indicates that the erythrocytosis in this family is caused by hypersensitivity of erythroid progenitors to Epo. The serum Epo concentration was low or low normal in all of the investigated family members, which is in good accordance with hypersensitivity to Epo. The erythrocytosis has not had any obvious effect on the health or life- span of the affected individuals. Many of them have reached an advanced age, and one of the affected family members has won several Olympic gold medals and world championships in endurance sports.

Self-Localization Estimation for Mobile Robot Based on Map-Matching Using Downhill Simplex Method

2019 ◽  
Vol 31 (2) ◽  
pp. 212-220 ◽  
Author(s):  
Kazuya Okawa ◽  
Keyword(s):  
Mobile Robot ◽  
Particle Filter ◽  
Simplex Method ◽  
Map Matching ◽  
Correct Position ◽  
Point Distribution ◽  
Downhill Simplex Method ◽  
The Difference ◽  
Downhill Simplex ◽  
Indoor And Outdoor

This paper describes a map-matching method which utilizes a downhill simplex method for self-localization estimation of a mobile robot for indoor and outdoor application. Although particle filter is widely established as a method of map-matching, it requires considerable time for recovery when the correct position is unidentifiable. One of the features of the downhill simplex method proposed in this paper is that the search point distribution is wide when it is challenging to determine a point as the correct position. However, it immediately shrinks when the correct position is identified. In this study, it is compared with particle filter and demonstrates the effectiveness of the proposed method through a discussion on the difference between the search methods.

Effect of Thermal Aging on Migration Characteristics of Heavy Metal in PET

2016 ◽  
Vol 850 ◽  
pp. 142-147 ◽  
Author(s):  
Xiao Yun Song ◽  
Zhuo Jun Sun ◽  
Chun Ping Li ◽  
Jian Gao ◽  
Jing Long Ma ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Inductively Coupled Plasma ◽  
Food Packaging ◽  
Thermal Ageing ◽  
Obvious Effect ◽  
Inductively Coupled ◽  
Aging Conditions ◽  
The Difference ◽  
Metal Migration ◽  
And Migration

Polyethylene terephthalate (PET) is usually used as food packaging materials. And the heavy metal introduced during the process of manufacture usually exists in the spaces between macromolecules as monomer form. When PET contacts with real food, some heavy metals will migrate into the food since the motion of these molecules overcomes the binding power. As a result, it does great harm to our health. In this article PET was disposed in different thermal ageing conditions in order to accelerate its aging process. Then the original and aged PET samples were tested by Different Scanning Calorimeter (DSC) to characterize its crystallinity. And migration experiments was conducted on them using 4% acetic acid (V/V) as food simulate, the heavy metal content in food simulates was detected by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), so that we can get the migration characteristics of heavy metal. The results show that different aging conditions can do harm to the structure of PET in varying degrees by changing its crystallinity and molecules arrangement. But the difference of crystallinity has no obvious effect on Sb migration characteristic of PET samples. While, the migration quantity of Sb increases significantly with the increase of migrate temperature. It will provide an important reference to the evaluation of use security and service life of PET in real usage to study the relation between heavy metal migration features and aging degree.

Sign in / Sign up

Export Citation Format

Share Document