Experimental Study on the Impact Factors of Sewage Sludge Wall Slip

2011 ◽  
Vol 422 ◽  
pp. 580-583
Author(s):  
Zhen Xing Li ◽  
Li Zhang ◽  
Ji Zhong Bai
Keyword(s):  
Sewage Sludge ◽  
Water Content ◽  
Strain Amplitude ◽  
High Speed ◽  
Influence Factors ◽  
Wall Slip ◽  
Impact Factors ◽  
Shear Rates ◽  
Time Stress ◽  
The Impact

The influence factors of sewage sludge wall slip were analyzed by using a rotational rheometer with parallel plate fixtures and with high speed camera. The technique involves checking the gap dependence of the stress/strain data and studying the time/stress data trend of strain stepped scanning. For sewage sludge of water content 80%, in the shearing flow it was found that, as the strain amplitude increasing, the stress data obtained at different gaps, then, at certain strain amplitude, started to diverge, indicating that wall slip occurred. But for sewage sludge of water content 87%, these curves are superimpose, indicating no slip occurred. While scanned sewage sludge water content 80% at different shear rates in 5s and 60s, it found that under 5s and 60s respectively, the shear rate is greater than 10s-1 and 0.5s-1 during time/stress curves appeared peak condition, shows slip occurred.

Experimental Analysis of the Slip Phenomenon of Sewage Sludge

2011 ◽  
Vol 243-249 ◽  
pp. 41-44
Author(s):  
Li Zhang ◽  
Min Quan Feng ◽  
Xiao Bin Zhang
Keyword(s):  
Water Content ◽  
Strain Amplitude ◽  
High Speed ◽  
Stress Amplitude ◽  
Wall Slip ◽  
Shearing Flow ◽  
Oscillatory Shear Flow ◽  
Straight Line ◽  
Strain Stress ◽  
Steady Shearing

Wall slip of sweage sludge and affect slip possible factors were studied experimentally by using a rotational rheometer with parallel plate fixtures and by means high speed camera. In the steady shearing flow, the technique involves placing a straight line marker monitoring of wall slip,checking the gap dependence of the stress/ strain data. For sweage sludge of water content 80%, in the shearing flow it was found that, as the strain amplitude increasing, the stress data obtained at different gaps, then, at the certain strain amplitude, started to diverge, indicating that wall slip occurred. But for sweage sludge of water content 90%, these curves are superimpose, indicating no slip occurred. In the dynamic oscillatory shear flow, we analyze the total wave. While strain, stress amplitude decreases with the time, while strain, the stress amplitude remains constant.

scholarly journals Examining partial proportional odds model in analyzing severity of high-speed railway accident

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jing Wang ◽  
Yinghan Wang ◽  
Yichuan Peng ◽  
Jian John Lu
Keyword(s):  
High Speed ◽  
Proportional Odds Model ◽  
Impact Factors ◽  
Proportional Odds ◽  
High Speed Railway ◽  
Severity Level ◽  
Content Type ◽  
Factors Affecting ◽  
Partial Proportional Odds Model ◽  
The Impact

Purpose The operation safety of the high-speed railway has been widely concerned. Due to the joint influence of the environment, equipment, personnel and other factors, accidents are inevitable in the operation process. However, few studies focused on identifying contributing factors affecting the severity of high-speed railway accidents because of the difficulty in obtaining field data. This study aims to investigate the impact factors affecting the severity of the general high-speed railway. Design/methodology/approach A total of 14 potential factors were examined from 475 data. The severity level is categorized into four levels by delay time and the number of subsequent trains that are affected by the accident. The partial proportional odds model was constructed to relax the constraint of the parallel line assumption. Findings The results show that 10 factors are found to significantly affect accident severity. Moreover, the factors including automation train protection (ATP) system fault, platform screen door and train door fault, traction converter fault and railway clearance intrusion by objects have an effect on reducing the severity level. On the contrary, the accidents caused by objects hanging on the catenary, pantograph fault, passenger misconducting or sudden illness, personnel intrusion of railway clearance, driving on heavy rain or snow and train collision against objects tend to be more severe. Originality/value The research results are very useful for mitigating the consequences of high-speed rail accidents.

scholarly journals Nonlinear Dynamic Analysis and Chaos Prediction of Grinding Motorized Spindle System

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Weitao Jia ◽  
Feng Gao ◽  
Yan Li ◽  
Wenwu Wu ◽  
Zhongwei Li
Keyword(s):  
Nonlinear Dynamic ◽  
High Speed ◽  
Chaotic Behavior ◽  
Nonlinear Dynamic Analysis ◽  
Phase Portraits ◽  
Impact Factors ◽  
Nonlinear Dynamic Model ◽  
Motorized Spindle ◽  
Spindle System ◽  
The Impact

The paper determines the impact factors of dynamics of a motorized spindle rotor system due to high speed: centrifugal force and bearing stiffness softening. A nonlinear dynamic model of the grinding motorized spindle system considering the above impact factors is constructed. Through system simulation including phase portraits and Poincaré map, the periodic behavior and chaotic behavior of the nonlinear grinding motorized spindle system are revealed. The threshold curve of chaos motion is obtained through the Melnikov method. The conclusion can provide a theoretical basis for researching deeply the dynamic behaviors of the grinding motorized spindle system.

Dynamic precision analysis and experimental verification of high-speed precision punch press

2016 ◽  
Vol 230 (20) ◽  
pp. 3655-3662 ◽  
Author(s):  
Fengfeng Hu ◽  
Yu Sun ◽  
Binbin Peng
Keyword(s):  
Elastic Wave ◽  
Dynamic Model ◽  
High Speed ◽  
Impact Factors ◽  
Superposition Method ◽  
Bottom Dead Center ◽  
Dynamic Precision ◽  
Modal Superposition Method ◽  
The Impact ◽  
Punch Press

In order to investigate the impact factors and their affection on high-speed precision multilink punch press (MPP), the dynamic model with different joint clearance was established, and the influence of different clearance and speed on the dynamic positional repeatability of bottom dead center (BDC) was analyzed. The elastic dynamic model of high-speed MPP was established, the affection of the elastic deformation and elastic wave on the positional repeatability of the BDC were presented by using modal superposition method to solve dynamic equation. Meanwhile, experiments on the dynamic repeatability of the BDC of the punch during working were completed. At last, the comparison of the experimental results with the analyzed results was given, and based on which, it can be concluded that the clearance, elastic wave and deformation are the key factors of the dynamic repeatability precision of the BDC.

Construction of Rural Financial System Based on the Concept of Low Carbon Economy

2014 ◽  
Vol 687-691 ◽  
pp. 4478-4481 ◽  
Author(s):  
Lei Yu
Keyword(s):  
Carbon Emissions ◽  
Agricultural Production ◽  
Influence Factors ◽  
Impact Factors ◽  
Low Carbon ◽  
Low Carbon Economy ◽  
Development Path ◽  
The Impact ◽  
The Empirical Analysis ◽  
Carbon Economy

Based on rural as research object, this paper mainly combines the local rural development present situation to measure rural carbon emissions, and with the help of Kaya model respectively. The rural residents' energy consumption and carbon emissions are generated by the impact factors of agricultural production LMDI decomposition. And it established the cointegration model of influence factors of the carbon in the empirical analysis. It seek a accord with the actual situation of rural low carbon economy development path.

scholarly journals Propagation of a Plastic Wave in Snow

1977 ◽  
Vol 19 (81) ◽  
pp. 175-183 ◽  
Author(s):  
Gorow Wakahama ◽  
Atsushi Sato
Keyword(s):  
Water Content ◽  
Wave Velocity ◽  
High Speed ◽  
Free Water ◽  
The Body ◽  
High Rate ◽  
Plastic Wave ◽  
Free Water Content ◽  
Moving Body ◽  
The Impact

AbstractWhen snow is pushed very fast by a moving body a plastic wave is generated at the head of the body. If the velocity of the moving body becomes close to that of the plastic wave, the snow may exert a great resistive force against the body as predicted by Yosida. It is, therefore, very important to study the dynamic behaviour of snow at a high rate of deformation, such as takes place when a snow plough is used on the highway, a train runs on a railroad covered with snow, or an avalanche occurs. Hence, this study is concerned with the safety and maintenance of winter traffic and transportation, and also with the generation and propagation of an avalanche. In order to clarify the detailed processes of the deformation of snow at high rates, laboratory experiments were made by compressing snow at high speed. The propagation of a plastic wave through snow was observed by using a high-speed camera and a pressure-detecting device. Analyses of the data obtained gave the velocity of the plastic wave for various kinds of snow whose density ranged from 0.17 to 0.46 Mg m-3and free-water content from o to 17%, whereby studies were made into the dependences on the density and free-water content of the velocity of the plastic wave. When the impact velocity was 4.3 ± 0.2 m s-1, the wave velocity ranged from 5 m s-1for a new snow to 12 m s-1for a fine-grained, well-settled snow. The plastic-wave velocity in wet snow was, in general, smaller than that in dry snow of the same density. Changes in density and structure of snow associated with the passage of a plastic wave were studied and discussed. The pressure at the wave front was measured; values of 0.1-0.3 bar were obtained, these are of the same order as the value estimated from theoretical formulae. The plastic-wave velocity was also observed for a confined snow, which showed a larger velocity and plastic strain than an unconfined snow.

scholarly journals Propagation of a Plastic Wave in Snow

1977 ◽  
Vol 19 (81) ◽  
pp. 175-183 ◽  
Author(s):  
Gorow Wakahama ◽  
Atsushi Sato
Keyword(s):  
Water Content ◽  
Wave Velocity ◽  
High Speed ◽  
Free Water ◽  
The Body ◽  
High Rate ◽  
Plastic Wave ◽  
Free Water Content ◽  
Moving Body ◽  
The Impact

AbstractWhen snow is pushed very fast by a moving body a plastic wave is generated at the head of the body. If the velocity of the moving body becomes close to that of the plastic wave, the snow may exert a great resistive force against the body as predicted by Yosida. It is, therefore, very important to study the dynamic behaviour of snow at a high rate of deformation, such as takes place when a snow plough is used on the highway, a train runs on a railroad covered with snow, or an avalanche occurs. Hence, this study is concerned with the safety and maintenance of winter traffic and transportation, and also with the generation and propagation of an avalanche. In order to clarify the detailed processes of the deformation of snow at high rates, laboratory experiments were made by compressing snow at high speed. The propagation of a plastic wave through snow was observed by using a high-speed camera and a pressure-detecting device. Analyses of the data obtained gave the velocity of the plastic wave for various kinds of snow whose density ranged from 0.17 to 0.46 Mg m-3 and free-water content from o to 17%, whereby studies were made into the dependences on the density and free-water content of the velocity of the plastic wave. When the impact velocity was 4.3 ± 0.2 m s-1, the wave velocity ranged from 5 m s-1 for a new snow to 12 m s-1 for a fine-grained, well-settled snow. The plastic-wave velocity in wet snow was, in general, smaller than that in dry snow of the same density. Changes in density and structure of snow associated with the passage of a plastic wave were studied and discussed. The pressure at the wave front was measured; values of 0.1-0.3 bar were obtained, these are of the same order as the value estimated from theoretical formulae. The plastic-wave velocity was also observed for a confined snow, which showed a larger velocity and plastic strain than an unconfined snow.

A Mini-Network Simulation Approach to Investigate the Capacity and Safety Aspects of National Rail Network

2021 ◽  
Author(s):  
Hamed Pouryousef ◽  
Monique Stewart ◽  
Som P. Singh ◽  
Anand Prabhakaran
Keyword(s):  
High Speed ◽  
Network Simulation ◽  
Network Capacity ◽  
Impact Factors ◽  
Simulation Approach ◽  
Analytical Technique ◽  
Rail Network ◽  
Advanced Technologies ◽  
The Impact ◽  
The U.S

Abstract Over the last decades there have been major technology advancements in the railroad industry to improve the operational safety as well as performance of freight trains in shared-use corridors. This study was focused on developing a methodology that allows evaluation of the impact of such advanced technologies over the safety and capacity aspects of the U.S. rail network using a benchmark mini-network simulation approach. A hypothetical mini-network of 5,000 miles of track with characteristics typical of the North American rail network was developed. Two hundred thirty two (232) daily trains, including a mix of intercity passenger, commuter, High Speed Rail and 78 freight trains, were used to simulate the traffic flow. Several network capacity and safety related parameters; network delay, network velocity, track utilization level, number of stops at stations, number of braking for route reservations, and number of stops at signals were analyzed in this study. The results of the benchmark network simulations were then extended to the U.S. rail network, using an analytical technique with assumptions for important parameters and impact factors such as total route miles, freight train-miles, number of sidings/yards, congestion level and age of fleets. The results indicate that the methodology is able to quantify the improvement in network capacity and safety features that can be obtained when advanced technologies are deployed on freight trains.

scholarly journals Identifying the Impact Factors of the Dynamic Strength of Mudded Intercalations during Cyclic Loading

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Changbin Yan ◽  
Xiao Xu ◽  
Lei Huang
Keyword(s):  
Water Content ◽  
Mineral Composition ◽  
Clay Mineral ◽  
Failure Time ◽  
Dynamic Strength ◽  
Clay Content ◽  
Confining Pressure ◽  
Impact Factors ◽  
The Impact ◽  
Clay Mineral Composition

Despite reports on previous research associated with the dynamic strength of mudded intercalations during cyclic loading, a systematic investigation of the impact factors of this strength is still valuable. This work aimed at experimentally revealing the impact factors of the strength along with their impacts. The potential impact factors considered in this work include (i) water content, (ii) clay mineral composition, (iii) clay content, (iv) confining pressure, and (v) cyclic failure time. Specimens of mudded intercalations were collected from China and were remolded and prepared for a dynamic triaxial test under cyclic loads. The test results showed that the dynamic strength is impacted by water content (strongly), clay mineral composition (moderately), confining pressure (moderately), and cyclic failure time (weakly); no significant impact of clay content was detected. Moreover, the dynamic cohesion is correlated with clay mineral composition (strongly), water content (moderately), and cyclic failure time (weakly); no significant correlation with clay content or confining pressure was detected. Finally, the dynamic friction angle is correlated with water content (strongly), clay content (moderately), and cyclic failure time (weakly); no significant correlation with clay mineral composition or confining pressure was detected.

The Research on the Impact Factors of Low-Quality Stands Soil Respiration after Different Transformations in Greater Higgnan Mountains

2012 ◽  
Vol 610-613 ◽  
pp. 3217-3221
Author(s):  
Hao Ji ◽  
Xi Bin Dong
Keyword(s):  
Soil Respiration ◽  
Respiration Rate ◽  
Temperature Sensitivity ◽  
Influence Factors ◽  
Soil Surface ◽  
Impact Factors ◽  
Forest Gap ◽  
Soil Respiration Rate ◽  
Respiration Rates ◽  
The Impact

Low-quality stands in Greater Higgnan Mountains were transformed by clear-cuttings with different area of forest gaps, then larch were planted after induced transformations. The LI-8150 multi-channel automated soil CO2 flux system was used to measure CO2 flux on soil surface. Changes of different soil respiration rates and influence factors were analyzed after different transformations. The results indicated that the soil respiration rates were all raised after different transformations compared with no interfered control plots. After analyzing different transformations comprehensively, it showed that the soil respiration rate performed a negative correlation with the soil density significantly, while the correlation with soil organic matter and litter weight in little decomposed was positive (p﹤0.05). The largest Q10 with forest gap area of 625 m2 was 3.561. Influenced by soil respiration rate, soil underground with depth of 10cm showed the strongest temperature sensitivity. The smallest Q10 with forest gap area of 900 m2 was 2.312, and temperature sensitivity of soil was the weakest.

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