An investigation into the effect of temperature-dependent stiffness of rail pads on vehicle-track coupled vibrations

2016 ◽  
Vol 231 (4) ◽  
pp. 444-454 ◽  
Author(s):  
Kai Wei ◽  
Zi-xuan Liu ◽  
Ying-chun Liang ◽  
Ping Wang
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Thermoplastic Polyurethane ◽  
Testing Machine ◽  
Center Frequency ◽  
Effect Of Temperature ◽  
Static Stiffness ◽  
High Temperature Stability ◽  
Temperature Dependent ◽  
Coupled Vibrations

To consider the rail pads of thermoplastic polyurethane elastomer (TPE), chloroprene rubber (CR), and ethylene propylene diene monomer (EPDM) that are usually used in the Chinese subway as test subjects, their static stiffness at temperatures of −40℃ to 70℃ was measured by a universal testing machine equipped with a temperature control box. Then, the influence of the temperature-dependent stiffness of the rail pads on the vertical vehicle-track coupled vibrations was investigated with application of a vehicle-track coupled dynamic model. It was found that the static stiffness of these rail pads exhibits a nonlinear variation with temperature. Their static stiffness is considerably sensitive to temperatures below 20℃, when the CR rail pad is the most sensitive. At temperatures above 20℃, their static stiffness slightly alters with increasing temperature. The temperature-dependent stiffness of these rail pads mainly affects the vertical vibrations of the vehicle system above the one-third octave center frequency of 31.5 Hz and the vertical rail vibrations near the center frequency of 63 Hz. Moreover, the influence of the low-temperature stiffness of rail pads at −40℃ to 20℃ is far greater than the effect of the high-temperature stiffness of rail pads at 20–70℃. Thus, TPE, CR, and EPDM rail pads have excellent high-temperature stability and adverse low-temperature sensibility.

Characteristics of Different Warm Mix Asphalt Compacted at Low Temperature

2011 ◽  
Vol 255-260 ◽  
pp. 3166-3170
Author(s):  
Li Ming Wang ◽  
Yi Qiu Tan ◽  
Zhen Wu Shi
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Crack Resistance ◽  
Temperature Stability ◽  
High Temperature Stability ◽  
Obvious Effect ◽  
Water Sensitivity ◽  
Active Additive ◽  
Surface Active ◽  
Temperature Crack

Additives on low temperature compaction and performances of compacted mixtures, the author devised low temperature environment compaction test, and then, comparison tests of volume parameters, high temperature stability, low temperature crack resistance and water sensitivity were conducted. Tests results showed that the wax additives and the surface-active additive can significantly contribute to mixtures low-temperature compactibility. The wax additive helps to improve high temperature stability obviously, and has no significant contribution to low temperature crack resistance and water sensitivity. The surface-active additive directly reduces water sensitivity, the wax additive indirectly plays the role of reducing water sensitivity by increasing the density of mixture, and the foam additive has no obvious effect on the water sensitivity.

Impact of Rheological Properties of Fiber Asphalt Mortar on Mixture Road Performance

2013 ◽  
Vol 734-737 ◽  
pp. 2287-2291 ◽  
Author(s):  
De Dong Guo
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Rheological Properties ◽  
Asphalt Mixture ◽  
Temperature Stability ◽  
Fiber Content ◽  
High Temperature Stability ◽  
Temperature Performance ◽  
Low Temperature Performance ◽  
Asphalt Mortar

Fiber asphalt concrete has been more and more widely used in highway construction. For analyzing high and low temperature performance of fiber asphalt mixture, rheological properties of fiber asphalt mortar were studied through indoor test. Impact of Rheological properties of the fiber asphalt mortar on high temperature and low temperature properties of asphalt mixture was analyzed. Results showed that the larger fiber content was, the better performance of asphalt mixture's high temperature stability, fiber asphalt mortar rut factor and rutting tests results of asphalt mixture were linear correlation, reflecting the high temperature performance of asphalt mixture; With the increase of fiber content, variation of stiffness modulus, creep rate indicators and mixture low temperature performance was consistent, and rheological properties of fiber asphalt mortar could characterize low temperature performance of asphalt mixture.

scholarly journals Study on Laboratory Experimental Pavement Performances of SEAM Modified Asphalt Mixture

2019 ◽  
Vol 136 ◽  
pp. 03010
Author(s):  
Ma Qingna ◽  
Zhao Zhiqin ◽  
Xu Qian ◽  
Sun Feng
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Asphalt Mixture ◽  
Temperature Stability ◽  
Water Stability ◽  
High Temperature Stability ◽  
Modified Asphalt ◽  
The Road ◽  
Road Performance ◽  
Property Index

Adding sulphur dilution asphalt modifier SEAM to asphalt mixture is not only a modifier of asphalt mixture, but also an additive of asphalt mixture. When the modifier is added into the asphalt mixture, the road performance of the asphalt mixture can be improved. This paper studies SEAM modified asphalt mixture the Marshall property index, temperature stability, Water stability and fatigue feature in the Laboratory. On the based of the result of the experiment and analysis, SEAM can improve the high temperature stability, Water stability and fatigue feature. But the low temperature stability can’t improve.

The tillering pattern in barley varieties: II. The effect of temperature, light intensity and daylength on the frequency of occurrence of the coleoptile node and second tillers in barley

1969 ◽  
Vol 72 (3) ◽  
pp. 423-435 ◽  
Author(s):  
R. Q. Cannell
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Light Intensity ◽  
Field Experiments ◽  
Tiller Number ◽  
Effect Of Temperature ◽  
Controlled Environment ◽  
Frequency Of Occurrence ◽  
Low Light ◽  
Late Sowing

SUMMARYControlled-environment experiments showed that development of the coleoptile node tiller (T1) was suppressed much more than that of the tiller appearing in the axil of the first true leaf (T2) by high temperature (24/15 °C; 19/10 °C; 10/6 °C), by reduced photoperiod (16 h; 12·5 h) or by low light intensity (1100 ft-c; 1000 ft-c), but minimally in the newest variety, Deba Abed. Unlike previous field experiments, the T1 tiller appeared on more Spratt Archer than Maris Badger plants. Maris Badger plants produced more T1 tillers in a high-low temperature regime (19/10 °C; 10/6 °C) than in continuous low temperature (10/6 °C). In a field experiment T1 tiller number (and yield), but not the number of other major shoots, were severely reduced by late sowing of Spratt Archer, progressively reduced in Maris Badger, but minimally in Deba Abed. This seemed to be associated with higher temperatures at later sowings.

RHIZOPUS ROOT ROT OF SUGAR BEET

1943 ◽  
Vol 21c (8) ◽  
pp. 235-248 ◽  
Author(s):  
A. A. Hildebrand ◽  
L. W. Koch
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Sugar Beet ◽  
Root Rot ◽  
The Other ◽  
Effect Of Temperature ◽  
Experimental Plot ◽  
Optimum Growth ◽  
Causal Organism ◽  
Sugar Beets

During the summer of 1942 sugar beets growing in an experimental plot at the Harrow laboratory were destroyed by a root rot of a type that apparently has been reported only once previously on this host in North America. Wilting of the foliage first attracts attention to affected plants, the roots of which show, externally, grayish-brown discoloured areas and, internally, fairly sharply-delimited, grayish to coffee-coloured lesions, affected tissues being more or less spongy in consistency. The causal organism, found to be a wound parasite, has been identified as Rhizopus arrhizus Fischer. The effect of temperature on the growth in culture and on the pathogenicity of this fungus and of representatives of the species, R. oryzae and R. nigricans, has been studied. It has been found that R. arrhizus and R. oryzae are relatively high temperature organisms, showing optimum growth at about 34° to 36 °C., and each capable of infecting and destroying artificially injured sugar beets most rapidly between 30° and 40 °C. R. nigricans, also a wound parasite is, on the other hand, a relatively low temperature organism showing optimum growth in culture at about 24° and displaying highest infection capability at about 14° to 16 °C.

Effect of Temperature on Crater Formation and Ejecta Composition in Aluminum Alloy Targets

2012 ◽  
Vol 706-709 ◽  
pp. 768-773
Author(s):  
Masahiro Nishida ◽  
Koichi Hayashi ◽  
Junichi Nakagawa ◽  
Yoshitaka Ito
Keyword(s):  
Aluminum Alloy ◽  
High Temperature ◽  
Low Temperature ◽  
Room Temperature ◽  
Effect Of Temperature ◽  
Crater Formation ◽  
Influence Of Temperature ◽  
Gas Gun ◽  
Influence Of Temperature On ◽  
Increasing Temperature

The influence of temperature on crater formation and ejecta composition in thick aluminum alloy targets were investigated for impact velocities ranging from approximately 1.5 to 3.5 km/s using a two-stage light-gas gun. The diameter and depth of the crater increased with increasing temperature. The ejecta size at low temperature was slightly smaller than that at high temperature and room temperature. Temperature did not affect the size ratio of ejecta. The scatter diameter of the ejecta at high temperature was slightly smaller than those at low and room temperatures.

Effect of Anti-Rut Agents on Properties of Asphalt Mixture

2014 ◽  
Vol 599 ◽  
pp. 110-114 ◽  
Author(s):  
Yan Hua Wang ◽  
Kuang Yi Liu ◽  
Hai Xia Zhang ◽  
Shan Li
Keyword(s):  
High Temperature ◽  
Fatigue Life ◽  
Low Temperature ◽  
Asphalt Mixture ◽  
Temperature Stability ◽  
High Temperature Stability ◽  
Damage Resistance ◽  
Damage Stability ◽  
Low Temperature Cracking ◽  
Water Damage

Anti-rut agent, named RPS-3000,was added into AC-25 asphalt mixture and its effects on high temperature stability, low temperature cracking resistance, water damage resistance and fatigue life were investigated in this paper. Results showed that the high temperature stability and low temperature crack resistance of the asphalt mixture improved significantly, the water damage stability increase slightly due to the introduction of anti-rut agents. Besides, the result of fatigue life test presented that excess amount of anti-rut agent may lead a deterioration of fatigue life. Keywords: Anti-rut agent; High temperature stability; Asphalt mixture

Influence of Double-Doped Admixtures on Asphalt Mixture Performance

2012 ◽  
Vol 557-559 ◽  
pp. 329-333
Author(s):  
Zhong Run Zheng ◽  
Chao Zhao ◽  
Yi Feng Zhao ◽  
Pei Song
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Asphalt Mixture ◽  
Temperature Stability ◽  
High Temperature Stability ◽  
Rutting Resistance ◽  
Splitting Test ◽  
Improvement Effect ◽  
Low Temperature Cracking ◽  
Better Than

This paper introduces an asphalt mixture that mixed with different admixtures, rutting resistance agent and lignin fiber, at the same time. Rutting test and freeze-thaw splitting test are used to analyze rutting resistance on the high temperature and low temperature cracking of the asphalt mixture. The experiments with different mixes material composition are conducted to analysis various properties of the two admixtures on the mixture, especially the high temperature stability, low temperature crack resistance and the law of improvement effect. In addition, the experiments also determine the optimal asphalt content of different type of mixtures. The results showed that the single-doped KTL rutting resistance or lignin fibers have some improvement in water temperature performance of asphalt mixture, stability improvement of double-doped admixture asphalt mixture is better than the single-doped asphalt mixture, such as KTL rutting resistance agents and lignin fibers

Dry Etching of PZT Films in an Ecr Plasma

1993 ◽  
Vol 310 ◽  
Author(s):  
Barbara Charlet ◽  
Kerrie E. Davies
Keyword(s):  
Surface Roughness ◽  
High Temperature ◽  
Low Temperature ◽  
Bias Voltage ◽  
Etch Rate ◽  
Effect Of Temperature ◽  
Ecr Plasma ◽  
Microwave Reactor ◽  
Pzt Films ◽  
Etch Profile

AbstractPZT films were etched in an ECR microwave reactor with RF polarization.The etch rate was evaluated using various gas mixtures including combinations of two of the following: C12, NF3, SF6 and HBr. The etch rate was measured as a function of the percentage of one gas in the mixture. Other parameters investigated included gas pressure, bias voltage on the electrode and substrate temperature.Results of the effect of temperature show that etch rates are higher on high temperature substrates than on low temperature substrates. A mixture of C12 and SF2 provided a PZT etch rate of 750 Å / min on a substrate, at approximately 100 °C. We evaluated the resultant etch profile and surface roughness

scholarly journals Starch Morphology and Metabolomic Analyses Reveal That the Effect of High Temperature on Cooked Rice Elongation and Expansion Varied in Indica and Japonica Rice Cultivars

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2416
Author(s):  
Nnaemeka Emmanuel Okpala ◽  
Mouloumdema Pouwedeou Potcho ◽  
Muhammad Imran ◽  
Tianyue An ◽  
Gegen Bao ◽  
...  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Oryza Sativa L ◽  
Effect Of Temperature ◽  
Japonica Rice ◽  
Rice Cultivars ◽  
Starch Granules ◽  
Cooked Rice ◽  
Temperature Regimes ◽  
Badh2 Gene

Rice (Oryza sativa L.) is mainly grouped into indica and japonica varieties. The aim of this study was to investigate the effect of temperature on cooked rice elongation, cooked rice expansion, and rice fragrance. This study was conducted in three growth temperature chambers with indica cultivar Basmati 385 (B385) and japonica cultivar Yunjingyou (YJY). Grains of B385 grown in low-temperature regimes had the highest cooked rice elongation and expansion, whereas the grains of YJY grown in high-temperature regimes had the highest cooked rice elongation and expansion. Starch granules of B385 grown in low-temperature regimes were more compact and bigger, compared to grains grown in medium- and high-temperature regimes. Conversely, the starch granules of YJY grown in high-temperature regimes were more compact and bigger, compared to those grown in medium- and low-temperature regimes. Metabolomic analyses showed that temperature affected the rice metabolome and revealed that cyclohexanol could be responsible for the differences observed in cooked rice elongation and expansion percentage. However, in both B385 and YJY, grains from low-temperature regimes had the highest 2-AP content and the lowest expression levels of the badh2 gene. The findings of this study will be useful to rice breeders and producers.

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