Arrhenius relationship and two-step scheme in AF hyperdynamics simulation of diffusion of Mg/Zn interface

2013 ◽  
Vol 23 (2) ◽  
pp. 508-516 ◽  
Author(s):  
Yong-quan WU ◽  
Xiu-ming LU ◽  
Tong SHEN
Keyword(s):  
Arrhenius Relationship

Structure and Electric Property of BaTi2O5 Film by Laser Ablation

2007 ◽  
Vol 350 ◽  
pp. 103-106
Author(s):  
Chuan Bin Wang ◽  
Rong Tu ◽  
Takashi Goto
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Laser Ablation ◽  
Curie Temperature ◽  
Electric Property ◽  
High Curie Temperature ◽  
Arrhenius Relationship ◽  
Permittivity Maximum

BaTi2O5 film was prepared on MgO (100) substrate by laser ablation, and the structure and electric property of the film were investigated. The film was b-axis oriented and epitaxially grown on the substrate along two in-plane directions with the a-axes ([100]-orientation) perpendicular to each other. The b-axis oriented BaTi2O5 film exhibited a sharp permittivity maximum (~ 2000) and had a high Curie temperature (750 K). The electrical conductivity increased with temperature and showed the Arrhenius relationship having an activation energy of 1.25 eV.

MINERALIZATION RATE CONSTANTS AND THEIR USE FOR ESTIMATING NITROGEN MINERALIZATION IN SOME CANADIAN PRAIRIE SOILS

1984 ◽  
Vol 64 (3) ◽  
pp. 333-343 ◽  
Author(s):  
C. A. CAMPBELL ◽  
Y. W. JAME ◽  
G. E. WINKLEMAN
Keyword(s):  
Nitrogen Mineralization ◽  
Rate Constants ◽  
Absolute Temperature ◽  
Canadian Prairie ◽  
Arrhenius Relationship ◽  
Soil Zone ◽  
Net Nitrogen Mineralization ◽  
Significant Difference ◽  
Potentially Mineralizable Nitrogen ◽  
Mineralizable Nitrogen

There is a need to provide quantitative relationships that will allow agronomists to estimate accurately the nitrogen-supplying power of soils while taking into account both temperature and soil moisture variations. The procedure for estimating net nitrogen mineralization proposed by Stanford and co-workers was used to determine Arrhenius relationships between the rate constants (k) and absolute temperature (°K) for 33 virgin and cultivated Western Canadian prairie surface (0–15 cm) soils. There was no significant difference in Arrhenius relationship between soils within each soil zone; thus, a single average Arrhenius equation was calculated per soil zone. Average Q10 for the Brown chernozemic soils was 2.75, for the Dark Brown, thin Black and thick Black chernozems, 2.18, and for the Gray luvisols, 2.0. These Q10 values are as high or higher than those reported in other parts of the world and may be related to the degree of degradation of the soil organic matter in these various soils. Culture had no marked effect on Q10 but sandy soils had higher Q10 than loams and clays. An equation for estimating net nitrogen mineralization for the Wood Mountain loam (a Brown chernozem) was tested using data from a previous study. The results were quite satisfactory, especially when the test data were derived under laboratory conditions where moisture was well controlled. The temperature functions presented herein can be used together with moisture functions and potentially mineralizable nitrogen results published earlier to make first estimates of net nitrogen mineralized during the growing season in the soils tested. Key words: Q10, Arrhenius relationship, potentially mineralizable nitrogen

Removal of Thiophene from Binary Mixtures Using Polyether Block Amide (PEBAX) Film by Pervaporation

2013 ◽  
Vol 726-731 ◽  
pp. 4101-4108 ◽  
Author(s):  
Kun Liu ◽  
Chuan Jie Fang ◽  
Zhi Qiang Li ◽  
Fang Fang Fan ◽  
Jian Jian Han
Keyword(s):  
Binary Mixtures ◽  
Separation Factor ◽  
Sulfur Compounds ◽  
Swelling Degree ◽  
Arrhenius Relationship ◽  
Operation Temperature ◽  
The World ◽  
Preferential Sorption ◽  
Activity Energy

Reduction of organosulfurs in gasoline has become an urgent requirement in the world, especially in China. The goal of this work focuses on removal of thiophene from binary mixtures of thiophene and n-heptane by means of pervaporation. The PEBAX homogenous film was prepared by coating. The swelling experiments of film were studied for the affinity of PEBAX film to thiophene. The swelling degree of film increased with increasing thiophene content in the mixtures. The result indicates the PEBAX film had preferential sorption to thiophene rather than n-heptane. Pervaporation experiments were studied for investigating separation properties of the film. The effect of thiophene concentration in feed and operation temperature on separation properties of the film was researched. The results of pervaporation showed that both total and thiophene flux increased with increase of thiophene content in the feed and temperature, but the separation factor deceased with their increase. The activity energy was calculated according to the Arrhenius relationship. This work may offer useful visions into the possibility of the separation of sulfur compounds from gasoline via pervaporation.

Intrinsic Gettering of Iron in Czochralski Silicon Crystals

1992 ◽  
Vol 262 ◽  
Author(s):  
M. Aoki ◽  
A. Hara ◽  
A. Ohsawa
Keyword(s):  
Experimental Method ◽  
Annealing Time ◽  
Experimental Approach ◽  
Surface Contamination ◽  
Defect Region ◽  
Czochralski Silicon ◽  
Low Level ◽  
Arrhenius Relationship ◽  
Silicon Crystals ◽  
Fe Impurities

ABSTRACTWe present a new experimental approach to studying the mechanism of intrinsic gettering of Fe in Czochralski silicon crystals. We present our experimental method and results for as-grown and intrinsic gettered wafers with high and low-level Fe surface contamination. We found that when annealing at the Fe supersaturation temperature, Fe concentration decreases faster in intrinsic gettered wafers than in as-grown wafers. Concentration saturated with annealing time for each sample and the saturated Fe concentration followed a simple Arrhenius relationship. Re-emission of Fe from the bulk defect region occurred above the gettering temperature. We conclude that in intrinsic gettering, Fe precipitates preferentially in the bulk defect region when the Fe impurities supersaturate as temperature drops.

Determining the energy of activation for the formation of lactulose in heated milks

1985 ◽  
Vol 52 (2) ◽  
pp. 275-280 ◽  
Author(s):  
Geoffrey R. Andrews
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
Temperature Profile ◽  
Energy Of Activation ◽  
Temperature Profiles ◽  
Milk Processing ◽  
Arrhenius Relationship ◽  
Processing Plants ◽  
Sterilized Milk ◽  
Ultra High Temperature

SUMMARYTime/temperature profiles were obtained for commercial ultra high temperature (UHT) and sterilized milk processing plants and for a pilot UHT plant operating under nine different conditions. Samples of milk from each process were analysed for lactulose by an enzymic method, yielding concentrations of lactulose of 4 to 118 mg/100 ml. The measured lactulose concentration could be derived from the corresponding time/temperature profile by assuming an Arrhenius relationship with an activation energy of 152 kJ mol-1, for the whole range of UHT and in-container processes examined.

Effect of voids on Arrhenius relationship between H-solubility and temperature in nickel

1997 ◽  
Vol 36 (2) ◽  
pp. 227-231
Author(s):  
Q.Y. Wu ◽  
X.K. Sun ◽  
M. Gao ◽  
Z.Q. Hu
Keyword(s):  
Arrhenius Relationship

The Effects of Temperature on the Biochemical Reaction Rates of the Activated Sludge Process

1982 ◽  
Vol 14 (1-2) ◽  
pp. 413-430 ◽  
Author(s):  
C W Randall ◽  
L D Benefield ◽  
D Buth
Keyword(s):  
Activated Sludge ◽  
Reaction Rates ◽  
Organic Substrate ◽  
Oxygen Utilization ◽  
Literature Information ◽  
Wastewater Treatment Process ◽  
Arrhenius Relationship ◽  
Microbial Population Dynamics ◽  
Effects Of Temperature ◽  
Substrate Stabilization

Experimental results and literature information were analyzed to define the effects of temperature change on the fundamental biochemical reactions that take place in the activated sludge wastewater treatment process. The reactions that were investigated were: organic substrate stabilization, production of cellular material, maintenance energy requirements, oxygen utilization, autooxidation of cellular mass and nitrification. Classic kinetic parameters and concepts were used in the analysis of the information. The variation of these parameters with temperature was compared to the variation predicted by the classic Arrhenius relationship for chemical reactions. The results were interpreted in terms of microbial population dynamics in the highly diverse mixed-culture system of activated sludge. It was found that all classically defined parameters follow the Arrhenius relationship over the 5 to 20°C range, but, except for substrate stabilization rate, do not follow it above 25°C.

Curing Kinetic Models of Resins for Microwave Assisted Pultrusion

2016 ◽  
Vol 721 ◽  
pp. 92-96 ◽  
Author(s):  
Pavel Akishin ◽  
Evgeny Barkanov ◽  
Nora Miazza ◽  
Santiago Galvez
Keyword(s):  
Kinetic Models ◽  
Microsoft Excel ◽  
Microwave Absorption Properties ◽  
Microwave Assisted ◽  
Arrhenius Relationship ◽  
Reaction Functions ◽  
Thermoset Resin ◽  
Curing Kinetic ◽  
Determination Of Parameters

Traditional description of the rate of the thermoset resin reaction by the Arrhenius relationship multiplied by a reaction function has been used in this study. The Kissinger method and ASTM E 698 procedure have been used for a determination of parameters of the Arrhenius relationship. N-th order, Prout-Tompkins and Kamal-Sourour models have been used and evaluated as the reaction functions to formulate the curing kinetic models of an epoxy resin.An engineering tool based on Microsoft Excel code has been developed by using the developed methodology. This tool has been successfully applied for a building of the curing kinetic model of vinyl ester resin with high microwave absorption properties to be used in the microwave assisted pultrusion processes.

scholarly journals Influence of Pyridoxal-5′-Phosphate on Temperature Relationship of Aspartate Aminotransferase and Alanine Aminotransferase

1982 ◽  
Vol 19 (6) ◽  
pp. 426-430 ◽  
Author(s):  
J C M Hafkenscheid ◽  
J Van Der Ven-Jongekrijg ◽  
TH De Boo
Keyword(s):  
Catalytic Activity ◽  
Reaction Temperature ◽  
Aspartate Aminotransferase ◽  
Alanine Aminotransferase ◽  
Entire Temperature Range ◽  
Temperature Relationship ◽  
Temperature Range ◽  
Arrhenius Relationship ◽  
Relationship Of

The influence of pyridoxal-5′-phosphate on the temperature relationship of aspartate aminotransferase and alanine aminotransferase has been determined. On varying the reaction temperature from 25° to 45° both enzymes showed small but significant deviations from a linear Arrhenius relationship. Supplementation with pyridoxal-5′-phosphate in general enhanced the catalytic activity to the same degree over the entire temperature range. Our results corroborate the findings of Rej but not those of Jung et al.

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