Hopping Conduction in a-Si:H Studied by Transient Photoconductivity with Optical Bias Illumination

1991 ◽  
Vol 219 ◽  
Author(s):  
Xing Chen ◽  
Upali Jayamaha ◽  
Chen-Yu Tai
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Localization Length ◽  
Quantitative Comparison ◽  
Experimental Results ◽  
Hopping Conduction ◽  
Transient Photocurrent ◽  
Transient Photoconductivity ◽  
Rate Of Decay ◽  
Charge Propagation

ABSTRACTCharge transport in a-Si:H films is studied by measuring the intensity and the rate of decay of the transient photocurrent with optical bias illumination. The optical bias enhancement of the transient photocurrent due to the probe beam decreases at first as the temperature is decreased, reaches a minimum at about 21OK, and then increases as the temperature is further decreased. This observation, together with the decay time measurements, indicates a change in the mechanism of charge propagation from conduction band transport at high temperature to hopping conduction in the low temperature. A theory of hopping conduction in tail states is developed to explain the experimental results. A quantitative comparison of the theoretical and experimental results is made to determine the localization length of the tail states.

Temperature Effect of Refining Performance by Al-Ti-B (C) Master Alloys

2011 ◽  
Vol 306-307 ◽  
pp. 475-480
Author(s):  
Cong Juan Gao ◽  
Hai Min Ding ◽  
Xiang Fa Liu
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Temperature Effect ◽  
Master Alloy ◽  
Experimental Results ◽  
Refining Effect ◽  
Master Alloys ◽  
Refining Performance ◽  
Tib2 Particles ◽  
Performance And Mechanism

Refining performance and mechanism of Al-5Ti-1B and Al-5Ti-0.4C master alloys at different temperature were investigated in this paper. The experimental results show that the refining effect of Al-5Ti-0.4C master alloy becomes worse as temperature increasing from 750°C to 1200°C, The refining effect of Al-5Ti-1B master alloy becomes worse as temperature increasing from 750°C to 1000°C. However, when the temperature is above 1000°C, the refining effect of Al-5Ti-1B master alloy recovers gradually as temperature increasing. TiB2 particles with TiAl3 layers are the heterogeneous nucleating cores of α-Al at low temperature. However, TiB2 particles are the heterogeneous nuclei of α-Al at high temperature.

Study on the Fuel-Saving Efficiency of Electric Vehicles under Empirical Test

2014 ◽  
Vol 494-495 ◽  
pp. 95-99
Author(s):  
Heng Jia Zhang ◽  
Bo Yang
Keyword(s):  
Energy Consumption ◽  
High Temperature ◽  
Low Temperature ◽  
Electric Vehicles ◽  
Empirical Test ◽  
Experimental Results ◽  
Fuel Saving ◽  
Travel Mode ◽  
Saving Effect ◽  
Daily Travel

This study constitutes an empirical fleet with electric vehicles (EV) and conventional vehicles (CV) which used by a large number of test participants who have different travel mileage to research the fuel-saving efficiency of EVs under daily travel mode within six months. Experimental results show that there is a great difference in energy consumption when EV running under different average temperatures and seasons. During summer (high temperature) and winter (low temperature) the energy consumption is bigger and the average electric consumption of 100-kilometer is 12.3 kWh/100km. The fuel-saving efficiency of EV in Tianjin empirical test is 66.7% and which is 74.8% in ten typical cities in China. EV has better fuel-saving effect in the whole country. The fuel-saving efficiency in working-days and rest-days is 80.3% and 42.2% respectively. EV has the best fuel-saving effect in working-days.

Exsolution and inversion in pigeonite from the Whin Sill, Northern England

1978 ◽  
Vol 36 (1) ◽  
pp. 474-475
Author(s):  
P.P.K. Smith
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Homogeneous Nucleation ◽  
Silicate Mineral ◽  
Antiphase Boundaries ◽  
Two Phase ◽  
Primitive Form ◽  
The Core ◽  
Nucleation Mechanisms ◽  
And Inversion

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.

Superconducting Wind Generators with Capacities of 10 MW and Larger

2020 ◽  
Vol 10 (10) ◽  
pp. 59-67
Author(s):  
Victor N. ANTIPOV ◽  
◽  
Andrey D. GROZOV ◽  
Anna V. IVANOVA ◽  
◽  
...  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Wind Power ◽  
State Of The Art ◽  
Superconducting Materials ◽  
Commercial Application ◽  
Synchronous Generators ◽  
High Temperature Superconducting ◽  
Wind Generators ◽  
Main Factor

The overall dimensions and mass of wind power units with capacities larger than 10 MW can be improved and their cost can be decreased by developing and constructing superconducting synchronous generators. The article analyzes foreign conceptual designs of superconducting synchronous generators based on different principles: with the use of high- and low-temperature superconductivity, fully superconducting or only with a superconducting excitation system, and with the use of different materials (MgB2, Bi2223, YBCO). A high cost of superconducting materials is the main factor impeding commercial application of superconducting generators. In view of the state of the art in the technology for manufacturing superconductors and their cost, a conclusion is drawn, according to which a synchronous gearless superconducting wind generator with a capacity of 10 MW with the field winding made of a high-temperature superconducting material (MgB2, Bi-2223 or YBCO) with the «ferromagnetic stator — ferromagnetic rotor» topology, with the stator diameter equal to 7—9 m, and with the number of poles equal to 32—40 has prospects for its practical use in the nearest future.

SOMERS LTA COPPER

Alloy Digest ◽  
1980 ◽  
Vol 29 (12) ◽  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Physical Properties ◽  
Copper Foil ◽  
Heat Treating ◽  
Dielectric Substrates ◽  
Printed Circuits

Abstract SOMERS LTA Copper is a wrought copper foil that can be annealed at 350 F in 15 minutes to the full-soft condition; its use simplifies the manufacture of printed circuits (LTA = Low-Temperature Annealable). LTA Copper is especially useful for foil weights up to and including one ounce per square foot (0.0014-inch thick) for laminating to high-temperature dielectric substrates. This datasheet provides information on composition, physical properties, and elasticity as well as fatigue. It also includes information on forming, heat treating, and machining. Filing Code: Cu-407. Producer or source: Olin Corporation.

CHRO-MOW

Alloy Digest ◽  
1958 ◽  
Vol 7 (2) ◽  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
Steel Company ◽  
Temperature Performance ◽  
Hot Work Steel ◽  
Crucible Steel ◽  
Red Hardness

Abstract CHRO-MOW is a tough hot work steel which will harden from a relatively low temperature in air. It possesses a desirable combination of toughness and red-hardness. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, and machining. Filing Code: TS-67. Producer or source: Crucible Steel Company of America.

NICLOY 5

Alloy Digest ◽  
1960 ◽  
Vol 9 (3) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Low Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Ferritic Steel ◽  
Heat Treating ◽  
Low Carbon ◽  
Temperature Performance

Abstract NICLOY 5 is a low carbon, nickel ferritic steel reecommended for low temperature service. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-96. Producer or source: Babcock & Wilcox Company.

The Application of X-Ray Diffraction at Elevated Temperatures to Study the Mechanism of Formation of Sodium Tripolyphosphate

1961 ◽  
Vol 5 ◽  
pp. 276-284
Author(s):  
E. L. Moore ◽  
J. S. Metcalf
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Amorphous Phase ◽  
Elevated Temperatures ◽  
Sodium Tripolyphosphate ◽  
X Ray Diffraction ◽  
Mechanism Of Formation ◽  
X Ray ◽  
Temperature Form ◽  
High Temperature Form

AbstractHigh-temperature X-ray diffraction techniques were employed to study the condensation reactions which occur when sodium orthophosphates are heated to 380°C. Crystalline Na4P2O7 and an amorphous phase were formed first from an equimolar mixture of Na2HPO4·NaH2PO4 and Na2HPO4 at temperatures above 150°C. Further heating resulted in the formation of Na5P3O10-I (high-temperature form) at the expense of the crystalline Na4P4O7 and amorphous phase. Crystalline Na5P3O10-II (low-temperature form) appears after Na5P3O10-I.Conditions which affect the yield of crystalline Na4P2O7 and amorphous phase as intermediates and their effect on the yield of Na5P3O10 are also presented.

scholarly journals GERMINATION AND VIGOUR IN SEEDS OF THE COWPEA IN RESPONSE TO SALT AND HEAT STRESS

2019 ◽  
Vol 32 (1) ◽  
pp. 143-151 ◽  
Author(s):  
Luma Rayane de Lima Nunes ◽  
Paloma Rayane Pinheiro ◽  
Charles Lobo Pinheiro ◽  
Kelly Andressa Peres Lima ◽  
Alek Sandro Dutra
Keyword(s):  
Salt Stress ◽  
Heat Stress ◽  
High Temperature ◽  
Low Temperature ◽  
Vigna Unguiculata ◽  
Salt Concentration ◽  
Dry Weight ◽  
Germination Percentage ◽  
Different Types ◽  
Different Temperatures

ABSTRACT Salinity is prejudicial to plant development, causing different types of damage to species, or even between genotypes of the same species, with the effects being aggravated when combined with other types of stress, such as heat stress. The aim of this study was to evaluate the tolerance of cowpea genotypes (Vigna unguiculata L. Walp.) to salt stress at different temperatures. Seeds of the Pujante, Epace 10 and Marataoã genotypes were placed on paper rolls (Germitest®) moistened with different salt concentrations of 0.0 (control), 1.5, 3.0, 4.5 and 6.0 dS m-1, and placed in a germination chamber (BOD) at temperatures of 20, 25, 30 and 35°C. The experiment was conducted in a completely randomised design, in a 3 × 4 × 5 scheme of subdivided plots, with four replications per treatment. The variables under analysis were germination percentage, first germination count, shoot and root length, and total seedling dry weight. At temperatures of 30 and 35°C, increases in the salt concentration were more damaging to germination in the Epace 10 and Pujante genotypes, while for the Marataoã genotype, damage occurred at the temperature of 20°C. At 25°C, germination and vigour in the genotypes were higher, with the Pujante genotype proving to be more tolerant to salt stress, whereas Epace 10 and Marataoã were more tolerant to high temperatures. Germination in the cowpea genotypes was more sensitive to salt stress when subjected to heat stress caused by the low temperature of 20°C or high temperature of 35°C.

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