Consideration of the Cross-Anisotropy of Different Materials of the Asphalt Surface Layer and Temperature to Determine Pavement Responses

2021 ◽  
Vol 13 (1) ◽  
pp. 140-151
Author(s):  
Minrui Guo ◽  
Xinglin Zhou
Keyword(s):  
Surface Layer ◽  
High Temperatures ◽  
Low Temperatures ◽  
Compressive Strain ◽  
Fatigue Cracking ◽  
Element Model ◽  
Rate Of Change ◽  
Temperature Relationship ◽  
The Cross ◽  
Cross Anisotropy

The effects of the cross-anisotropy of different materials of the asphalt surface layer and the depth-temperature relationship on pavement responses and damage are investigated. A three-dimensional Finite-Element Model (FEM) of the pavement, which considers the depth-temperature relationship of the surface layer under moving tire load, is developed. Pavement damage models are established to evaluate the damage ratio for primary rutting and fatigue cracking. The results show that the compressive strain at the bottom of the surface layer increases as the temperature increases, and the cross-anisotropy (n-value) decreases, indicating that a decrease in the horizontal modulus of different materials of the surface layer increases the damage ratio for primary rutting at high temperatures. The tensile strain at the bottom of the surface layer declines as the n-value increases to 1. For the same change in the n-value, the rate of change of the damage ratio for fatigue cracking is greater at low temperatures than at high temperatures, demonstrating that the number of allowable load repetitions is more sensitive at low temperatures. In addition, the effect of cross-anisotropy and temperature on the vertical stress are larger on the top of the base than in the subbase and subgrade.

Static 1H dynamic nuclear polarization with the biradical TOTAPOL: a transition between the solid effect and the cross effect

2014 ◽  
Vol 16 (14) ◽  
pp. 6687-6699 ◽  
Author(s):  
Daphna Shimon ◽  
Akiva Feintuch ◽  
Daniella Goldfarb ◽  
Shimon Vega
Keyword(s):  
High Temperatures ◽  
Dynamic Nuclear Polarization ◽  
Low Temperatures ◽  
Nuclear Polarization ◽  
Cross Effect ◽  
Solid Effect ◽  
The Cross

Static 1H-DNP with TOTAPOL: the solid effect (SE) dominant at low temperatures; the cross effect (CE) dominant at high temperatures; and DNP-buildup: Tbu(SE) < Tbu(CE).

Low solubility of alumina in enstatite and uncertainties in estimated palaeogeotherms

1978 ◽  
Vol 288 (1355) ◽  
pp. 471-486 ◽  
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Alumina Content ◽  
Equilibrium Solubility ◽  
Low Solubility

Spurious kinks in estimated palaeogeotherms may result from small errors in the calibration of the geothermometers and geobarometers. New data indicate that the equilibrium solubility of alumina in enstatite is even less than shown by recent studies, and that the slopes (d T /d P ) of the isopleths of equal alumina content are steeper than hitherto believed. Consequently, pressures of equilibration estimated from current formulations of the orthopyroxene-garnet geobarometer will be too high at high temperatures (> 1200 °C) and too low at low temperatures.

scholarly journals Environmental temperature during early life affects the personality of mosquitofish in adulthood

2021 ◽  
Author(s):  
Haifeng Li ◽  
Xinyu ZHang ◽  
Yi Wu ◽  
Feng ZHang ◽  
CHunlin Li
Keyword(s):  
Body Length ◽  
High Temperatures ◽  
Low Temperatures ◽  
Early Life ◽  
Environmental Temperature ◽  
Phenotypic Trait ◽  
Behavioral Syndrome ◽  
Growing Up ◽  
Female Fish ◽  
Behavioral Traits

Abstract Personality has been observed in a variety of animal taxa with important implications in ecology and evolution. Exploring the influence of environmental temperature during early life on personality could help to understand the ontogeny of this phenotypic trait in animals. In this study, we reared newborn mosquitofish Gambusia affinis at high (30°C) and low (25°C) water temperatures and measured their shyness and exploration upon sexual maturity. We tested the repeatability of each behavioral trait; the correlation between them; and the effects of rearing temperature, sex, and body length on the behaviors. When growing up at low temperatures, female fish exhibited repeatability in shyness and exploration, and males exhibited marginal repeatability in shyness. However, neither of the 2 behaviors were repeatable when the fish were reared at high temperatures. There was a negative correlation between shyness and exploration, indicating that the 2 behaviors comprise a behavioral syndrome in this species. Mosquitofish reared at high temperatures were more explorative than those reared at low temperatures, while there was no difference in shyness between the 2 treatments. Body length and sex had no significant effects on the average values of the 2 behaviors. The results indicate that environmental temperature during early life could shape the personality of mosquitofish and modify the average of the behavioral traits. These findings might provide insights to understand the ontogeny of animal personality and how changes in environmental temperature influence animal dispersal by shaping their personality.

Analysis of Ferroelectric Microcapacitors by Scanning Probe Microscope

2004 ◽  
Vol 811 ◽  
Author(s):  
Nobuhiro Kin ◽  
Koichiro Honda
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Evaluation System ◽  
Ferroelectric Material ◽  
Scanning Probe Microscope ◽  
Scanning Probe ◽  
Electrical Heater ◽  
Device Processing ◽  
Probe Microscope ◽  
The Impact

ABSTRACTTo develop higher density FRAM requires reducing cell size. Therefore, the size effects resulting from device processing and the material's physical properties must be measured. Therefore, analyzing the electric characteristics of a single bit cell capacitor has become important. Two known characteristics of ferroelectric material are that the Vc increases at low temperatures, and the Pr falls at high temperatures. To further evaluate the impact of temperature on ferroelectrics, we constructed a new evaluation system based on a scanning probe microscope, that can measure the electric characteristics of a single bit cell capacitor. This system can be used in the temperature range from −120 degrees to 300 degrees C. We accomplished this by circulating liquid nitrogen around a SPM stage and by using an electrical heater. We measured the electrical properties of ferroelectric microcapacitors by using a sample with IrOx/PZT/Pt structure. Our measurements revealed that 2Pr really increases at low temperatures, and Pr decreases at high temperatures. That is, we have shown that Vc increases 30% at low temperatures and Pr decreases 10% also in an actual FRAM single bit cell capacitor.

Effects of ternary additions on the deformation behavior of single crystals of MoSi2

2000 ◽  
Vol 646 ◽  
Author(s):  
Haruyuki Inui ◽  
Koji Ishikawa ◽  
Masaharu Yamaguchi
Keyword(s):  
Yield Strength ◽  
Strain Rate ◽  
Single Crystals ◽  
Creep Strain ◽  
High Temperatures ◽  
Low Temperatures ◽  
Deformation Behavior ◽  
Creep Strain Rate ◽  
Compression Creep ◽  
Ternary Additions

ABSTRACTEffects of ternary additions on the deformation behavior of single crystals of MoSi2 with the hard [001] and soft [0 15 1] orientations have been investigated in compression and compression creep. The alloying elements studied include V, Cr, Nb and Al that form a C40 disilicide with Si and W and Re that form a C11b disilicide with Si. The addition of Al is found to decrease the yield strength of MoSi2 at all temperatures while the additions of V, Cr and Nb are found to decrease the yield strength at low temperatures and to increase the yield strength at high temperatures. In contrast, the additions of W and Re are found to increase the yield strength at all temperatures. The creep strain rate for the [001] orientation is significantly lower than that for the [0 15 1] orientation. The creep strain rate for both orientations is significantly improved by alloying with ternary elements such as Re and Nb.

scholarly journals Forging, textures, and deformation systems in a B2 FeAl alloy

1999 ◽  
Vol 14 (3) ◽  
pp. 715-728 ◽  
Author(s):  
P. Zhao ◽  
D. G. Morris ◽  
M. A. Morris Munoz
Keyword(s):  
High Temperature ◽  
Flow Stress ◽  
Slip System ◽  
High Temperatures ◽  
Low Temperatures ◽  
High Speed ◽  
Deformation Texture ◽  
Slip Systems ◽  
Feal Alloy ◽  
Very High

High-temperature forging experiments have been carried out by axial compression testing on a Fe–41Al–2Cr alloy in order to determine the deformation systems operating under such high-speed, high-temperature conditions, and to examine the textures produced by such deformation and during subsequent annealing to recrystallize. Deformation is deduced to take place by the operation of 〈111〉 {110} and 〈111〉{112} slip systems at low temperatures and by 〈100〉{001} and 〈100〉{011} slip systems at high temperatures, with the formation of the expected strong 〈111〉 textures. The examination of the weak 〈100〉 texture component is critical to distinguishing the operating slip system. Both texture and dislocation analyses are consistent with the operation of these deformation systems. Recrystallization takes place extremely quickly at high temperatures (above 800 °C), that is within seconds after deformation and also dynamically during deformation itself. Recrystallization changes the texture such that 〈100〉 textures superimpose on the deformation texture. The flow stress peak observed during forging is found at a very high temperature. Possible origins of the peak are examined in terms of the operating slip systems.

The Influence of Photoperiod and Temperature on the Induction of Diapause in Diataraxia Oleracea L. (Lepidoptera)

1950 ◽  
Vol 27 (3) ◽  
pp. 365-376
Author(s):  
M. J. WAY ◽  
B. A. HOPKINS
Keyword(s):  
Light Intensity ◽  
High Temperatures ◽  
Larval Stage ◽  
Low Temperatures ◽  
Food Plant ◽  
Larval Food ◽  
Controlled Substances ◽  
Larval Food Plant

The induction of diapause in the pupa of Diataraxia oleracea is influenced by temperature and photoperiod during the larval stage. Low temperatures and short photoperiods tend to induce diapause while high temperatures and long photoperiods tend to prevent diapause. Diapause is not influenced by light intensity during the larval stage providing the intensity is above a certain minimum. Diapause is prevented at high temperatures (30-34° C.) if the larvae are reared in darkness. The photoperiod is operative as a factor influencing diapause only between the beginning of the moulting sleep prior to ecdysis to the last instar and the 3rd-5th day of the last instar. A single diapause-preventing photo-period during the moulting sleep is probably sufficient to prevent diapause. Diapause in D. oleracea is not influenced by photoperiodically controlled substances in the larval food plant.

scholarly journals A reservoir-damage-free encapsulated acid dually controlled by hydrogen ion concentration and temperature

RSC Advances ◽  
2019 ◽  
Vol 9 (58) ◽  
pp. 33733-33746
Author(s):  
Zhifeng Luo ◽  
Nanlin Zhang ◽  
Liqiang Zhao ◽  
Lin Wu ◽  
Pingli Liu ◽  
...  
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Gas Industry ◽  
Hydrogen Ion Concentration ◽  
Oil And Gas Exploration ◽  
Exploration And Development

Oil and gas exploration and development extends from medium-low temperatures to high and ultra-high temperatures with the development of the oil and gas industry.

Evaluate the Importance of Shear Modulus in Dynamic FEM of Flexible Pavement Considering AC Cross-Anisotropy

2016 ◽  
Author(s):  
Mesbah U. Ahmed ◽  
Rafiqul A. Tarefder
Keyword(s):  
Shear Modulus ◽  
Resilient Modulus ◽  
Vertical Plane ◽  
Element Model ◽  
Tire Pressure ◽  
Stress Strain ◽  
Viscoelastic Parameters ◽  
Cross Anisotropy ◽  
As Stress ◽  
Stress Dependent

Goal of this study is to evaluate the effect of shear modulus variation on pavement responses, such as stress-strain, under dynamic load incorporating the AC cross-anisotropy. A dynamic Finite Element Model (FEM) of an instrumented asphalt pavement section on Interstate 40 (I-40) near Albuquerque, New Mexico, is developed in ABAQUS to determine stress-strain under truck tire pressure. Laboratory dynamic modulus tests were conducted on the AC cores to determine the temperature and frequency varying modulus values along both vertical and horizontal directions. The test outcomes are used to produce cross-anisotropic and viscoelastic parameters. Resilient modulus tests are conducted on granular aggregates from base and subbase layer to determine the nonlinear elastic and stress-dependent modulus values. These material parameters are integrated to the FEM through a FORTRAN subroutine via User Defined Material (UMAT) in the ABAQUS. The developed FEM is validated using the pavement deflections and stress-strain data under Falling Weight Deflectometer (FWD) test. The validated dynamic FEM is simulated under the non-uniform vertical tire contact stress. For the parametric study to investigate the effect of shear modulus variation on pavement responses, the validated FEM is simulated by varying the shear modulus in the AC layer. The results show that the variation in shear modulus along a vertical plane barely affects the tensile strain at the bottom of the AC layer and vertical compressive strains in both AC and unbound layers.

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