scholarly journals Experimental Study on Wet Skid Resistance of Asphalt Pavements in Icy Conditions

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1201 ◽  
Author(s):  
Yan ◽  
Mao ◽  
Zhong ◽  
Zhang ◽  
Zhang
Keyword(s):  
Surface Friction ◽  
Melting Process ◽  
Asphalt Pavements ◽  
Skid Resistance ◽  
Ice Melting ◽  
Temperature Range ◽  
Bitumen Emulsion ◽  
Image Measure ◽  
The Difference ◽  
Increasing Temperature

In this research, the durability of skid resistance during the ice melting process with temperature increasing from −5 °C to 10 °C was characterized by means of a British Pendulum Skid Tester. Four types of pavement surfaces were prepared and tested. The difference between two antiskid layers prepared with bitumen emulsion was the aggregate. The detailed angularity and form 2D index of fine aggregates used for antiskid surfaces, characterized by means of the Aggregate Image Measure System (AIMS) with micro image analysis methods, were then correlated with British Pendulum Number (BPN) values. Results indicate that skid resistance has the lowest value during the ice-melting process. The investigated antiskid layers can increase the surface friction during icy seasons. In icy conditions, the skid resistance behavior first worsens until reaches the lowest value, and then increases gradually with increasing temperature. Results from ice-melting conditions on four investigated pavement surfaces give the same temperature range where there will be lowest skid resistance. That temperature range is from 3 °C to 5 °C. A thicker ice layer will result in a lower skid resistance property and smaller “lowest BPN”.

Friction on Wet Surfaces of Tire-Tread-Type Vulcanizates

1964 ◽  
Vol 37 (4) ◽  
pp. 878-893 ◽  
Author(s):  
Barbara E. Sabey ◽  
G. N. Lupton
Keyword(s):  
Skid Resistance ◽  
Correct Interpretation ◽  
Temperature Range ◽  
The Road ◽  
Test Conditions ◽  
Maximum Value ◽  
Rubber Compounds ◽  
Materials Used ◽  
Increasing Temperature ◽  
Styrene Butadiene

Abstract A laboratory investigation has been made into the variation with temperature of the hardness and resilience of a wide variety of rubber compounds of the tire tread type. The effect of hardness and resilience on the fractional properties of the compounds under wet conditions has also been studied. In the first series of tests the resilience and hardness of 25 compounds were measured over a temperature range 0° to 80° C. All were vulcanized tire tread type compounds, and the basic materials used comprised 14 natural rubbers, 7 styrene/butadiene (SBR) rubbers, 2 butyl, 1 polybutadiene, and 1 ethylene/propylene. The tests showed a marked increase in resilience with increasing temperature for all compounds except the polybutadiene; the hardness of all compounds changed very little with temperature, only a slight decrease being observed over the whole temperature rise. Nine compounds of representative resilience and hardness were selected for a second series of tests in which friction was measured over a temperature range 1° to 40° C on seven surfaces representing roads of different textures. For eight of the compounds, friction values decreased with increase in temperature; for the other compound the friction increased to a maximum value at 30° C. These changes in friction cannot be explained by changes in hardness of the compounds, but they are in accordance with resilience changes, taking into account the different test conditions obtaining in the friction and resilience tests. The friction tests also showed that with the portable skid-resistance tester used to measure friction the sharpness of the projections in the road surface is more important than their size in determining the friction values under wet conditions, even when rubber compounds of low resilience are used. The implications of the findings and their application to the study of friction between tire and road are discussed. In particular, they have a bearing on the correct interpretation of resilience measurements of tire tread materials in relation to friction values under wet conditions.

scholarly journals Особенности доменной структуры гексаферрита BaFe-=SUB=-12-=/SUB=-O-=SUB=-19-=/SUB=- вблизи температуры Кюри

2020 ◽  
Vol 62 (7) ◽  
pp. 1050
Author(s):  
А.А. Безлепкин ◽  
С.П. Кунцевич
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Domain Walls ◽  
Physical Mechanism ◽  
Structural Features ◽  
Temperature Range ◽  
The Difference ◽  
Increasing Temperature ◽  
Curie Temperature Tc ◽  
Ordered State

The structural features of the domain walls of the BaFe12O19 hexaferrite near the Curie temperature TC = 724 K were studied. The studies were performed on single-crystal samples in an alternating magnetic field with a frequency of 73 MHz and 71 MHz with a constant magnetic field in the range 0–0.25 kOe. In BaFe12O19 at a temperature of T1 = 716 K, the magnetic structure of the domain walls changes – the Bloch walls transform into linear walls with increasing temperature. The value ΔТ = Tc – T1≈8 K. The physical mechanism considered in the work, which determines the difference between the temperature range of the existence of the magnetically ordered state and the temperature range of the existence of the Bloch domain walls, is consistent with experimental results. The estimated calculation of the criterion for the transition of the Bloch domain wall to a linear wall at T1 = 716 K corresponds to the obtained experimental data.

Ultrasonic study of liquid-quenched sulfur from room temperature to 200 °C

1994 ◽  
Vol 9 (12) ◽  
pp. 3170-3173 ◽  
Author(s):  
Akira Doi ◽  
Satoru Kariya ◽  
Hiroaki Kamioka
Keyword(s):  
Thermal Analysis ◽  
Room Temperature ◽  
Polymerization Process ◽  
Structural Units ◽  
Ultrasonic Study ◽  
Temperature Range ◽  
The Difference ◽  
Increasing Temperature

When liquid S is heated above 159 °C, the S8 rings (which are the dominant structural units below this temperature) break open and polymerize into helical chains (S∞). Therefore, samples quenched from liquids at temperatures above or below 159 °C would be different in various properties by the difference in the amount of S∞. The present ultrasonic study of liquid-quenched S in the temperature range from room temperature to 200 °C has revealed this difference. It has been demonstrated that ultrasonics is as powerful as a conventional thermal analysis in dealing with the variation of a material with increasing temperature, even though both techniques were found to be relatively insensitive to the polymerization process.

scholarly journals Reduction kinetics of lead-rich slag with carbon in the temperature range of 1073 to 1473K

2013 ◽  
Vol 49 (2) ◽  
pp. 201-206 ◽  
Author(s):  
X. Hou ◽  
K.C. Chou ◽  
B. Zhao
Keyword(s):  
Activation Energy ◽  
Reaction Rate ◽  
Graphite Crucible ◽  
Reduction Reaction ◽  
Synthetic Slag ◽  
Reduction Kinetics ◽  
Temperature Range ◽  
Diffusion Controlled ◽  
The Difference ◽  
Increasing Temperature

Extensive experiments have been carried out on the reduction of lead-rich slag in graphite crucible at temperature range of 1073 to 1473K. The reduction kinetics was also compared between industrial sinters and synthetic slags. The extent of reduction was measured by the volume of CO-CO2 gas produced at a given temperature and time. It was found that, at a given temperature, the reaction rate between the slag and carbon was initially fast and then slow as the extent of the reaction increases. Only limited reaction between slag and carbon occurred at temperatures below 1173K. At temperatures above 1173K, the reaction rate increased significantly with increasing temperature. The reduction reaction was found to be mainly liquid-solid reaction, which was chemically controlled at initial stage and diffusion controlled at later stage. The apparent activation energy was calculated to be 83.8 kJ/mol at chemically controlled stage and 224.9 kJ/mol at diffusion controlled stage for reduction of industrial sinter. For the synthetic slag, the reaction activation energy was 102.9 kJ/mol at chemically controlled stage and 259.4 kJ/mol at diffusion controlled stage. The difference of the activation energy between industrial sinter and synthetic slag can be explained by the difference in their CaO/SiO2 ratios.

PORE-SCALE SIMULATION OF ICE MELTING PROCESS IN POROUS MEDIA

2017 ◽  
Author(s):  
Pu He ◽  
Li Chen ◽  
Yu-Tong Mu ◽  
Wen-Quan Tao
Keyword(s):  
Porous Media ◽  
Melting Process ◽  
Pore Scale ◽  
Ice Melting

scholarly journals Cell mechanical properties of human breast carcinoma cells depend on temperature

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christian Aermes ◽  
Alexander Hayn ◽  
Tony Fischer ◽  
Claudia Tanja Mierke
Keyword(s):  
Mechanical Properties ◽  
Power Law ◽  
Cell Mechanics ◽  
Cell Types ◽  
Creep Response ◽  
Temperature Range ◽  
Myosin Filaments ◽  
Cell Mechanical Properties ◽  
Increasing Temperature ◽  
Mcf 7

AbstractThe knowledge of cell mechanics is required to understand cellular processes and functions, such as the movement of cells, and the development of tissue engineering in cancer therapy. Cell mechanical properties depend on a variety of factors, such as cellular environments, and may also rely on external factors, such as the ambient temperature. The impact of temperature on cell mechanics is not clearly understood. To explore the effect of temperature on cell mechanics, we employed magnetic tweezers to apply a force of 1 nN to 4.5 µm superparamagnetic beads. The beads were coated with fibronectin and coupled to human epithelial breast cancer cells, in particular MCF-7 and MDA-MB-231 cells. Cells were measured in a temperature range between 25 and 45 °C. The creep response of both cell types followed a weak power law. At all temperatures, the MDA-MB-231 cells were pronouncedly softer compared to the MCF-7 cells, whereas their fluidity was increased. However, with increasing temperature, the cells became significantly softer and more fluid. Since mechanical properties are manifested in the cell’s cytoskeletal structure and the paramagnetic beads are coupled through cell surface receptors linked to cytoskeletal structures, such as actin and myosin filaments as well as microtubules, the cells were probed with pharmacological drugs impacting the actin filament polymerization, such as Latrunculin A, the myosin filaments, such as Blebbistatin, and the microtubules, such as Demecolcine, during the magnetic tweezer measurements in the specific temperature range. Irrespective of pharmacological interventions, the creep response of cells followed a weak power law at all temperatures. Inhibition of the actin polymerization resulted in increased softness in both cell types and decreased fluidity exclusively in MDA-MB-231 cells. Blebbistatin had an effect on the compliance of MDA-MB-231 cells at lower temperatures, which was minor on the compliance MCF-7 cells. Microtubule inhibition affected the fluidity of MCF-7 cells but did not have a significant effect on the compliance of MCF-7 and MDA-MB-231 cells. In summary, with increasing temperature, the cells became significant softer with specific differences between the investigated drugs and cell lines.

Influence of Temperature on Hydraulic Conductivity in Compacted Bentonite

1997 ◽  
Vol 506 ◽  
Author(s):  
W. J. Cho ◽  
J. O. Lee ◽  
K. S. Chun
Keyword(s):  
Hydraulic Conductivity ◽  
Influence Of Temperature ◽  
Temperature Range ◽  
Compacted Bentonite ◽  
Influence Of Temperature On ◽  
Water Saturated ◽  
Increasing Temperature ◽  
Good Agreement

ABSTRACTThe hydraulic conductivities in water saturated bentonites at different densities were measured within temperature range of 20 to 80 °C. The results show that the hydraulic conductivities increase with increasing temperature. The hydraulic conductivities of bentonites at the temperature of 80 °C increase up to about 3 times as high as those at 20 °C. The measured values are in good agreement with those predicted. The change in viscosity of water with temperature contributes greatly to increase of hydraulic conductivity.

Plastic Deformation of Mo(Si,Al)2 Single Crystals with the C40 Structure

1996 ◽  
Vol 460 ◽  
Author(s):  
M. Moriwaki ◽  
K. Ito ◽  
H. Inui ◽  
M. Yamaguchi
Keyword(s):  
Single Crystals ◽  
Deformation Behavior ◽  
Basal Slip ◽  
Room Temperature ◽  
Slip Systems ◽  
Temperature Range ◽  
Al Content ◽  
Partial Dislocations ◽  
Increasing Temperature ◽  
Critical Resolved Shear Stress

ABSTRACTThe deformation behavior of single crystals of Mo(Si,Al)2 with the C40 structure has been studied as a function of crystal orientation and Al content in the temperature range from room temperature to 1500°C in compression. Plastic flow is possible only above 1100°C for orientations where slip along <1120> on (0001) is operative and no other slip systems are observed over whole temperature range investigated. The critical resolved shear stress for basal slip decreases rapidly with increasing temperature and the Schmid law is valid. Basal slip appears to occur through a synchroshear mechanism, in which a-dislocations (b=1/3<1120>) dissociate into two synchro-partial dislocations with the identical Burgers vector(b*1/6<1120>) and each synchro-partial further dissociates into two partials on two adjacent planes.

The temperature dependence of the long-range order parameter of Ni3Al

1977 ◽  
Vol 10 (1) ◽  
pp. 14-17 ◽  
Author(s):  
D. P. Pope ◽  
J. L. Garin
Keyword(s):  
Long Range ◽  
Order Parameter ◽  
Anomalous Behavior ◽  
Range Order ◽  
Range Order Parameter ◽  
Long Range Order ◽  
Temperature Range ◽  
Ordered Alloys ◽  
Fine Particle Size ◽  
Increasing Temperature

The macroscopic yield stress of Ni3Al increases rapidly with temperature, reaching a maximum at about 700°C. Such anomalous behavior has been observed in other ordered alloys which undergo partial disordering with increasing temperature, e.g. Cu3Au. The long-range order parameter, S, of stoichiometric Ni3Al powder was measured over the temperature range 25°C to 1000°C and great care was taken to ensure a fine particle size and thus avoid extinction effects. The results of this study showed that, in Ni3Al, S remains constant at about 0.93 over the entire temperature range investigated. This means that theories relating the strength of ordered alloys to S are not applicable to Ni3Al.

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