scholarly journals THE SULFONIUM SALT OF MUSTARD GAS: BIS-ß-[BIS(ß-HYDROXYETHYL) SULFONIUM] ETHYLSULFIDE DICHLORIDE (H·2TDG)

1947 ◽  
Vol 30 (6) ◽  
pp. 457-464 ◽  
Author(s):  
Roger M. Herriott
Keyword(s):  
Activation Energy ◽  
Temperature Coefficient ◽  
Arrhenius Equation ◽  
Effect Of Temperature ◽  
Mustard Gas ◽  
Hydrolysis Constant ◽  
Dilute Solutions ◽  
Sulfonium Salt ◽  
Simple Method

1. The sulfonium salt H·2TDG is formed when H is mixed with even dilute solutions of TDG. Crystalline H·2TDG was isolated from such a reaction mixture. A simple method of preparation of this salt is outlined. 2. A material which differs from H·2TDG in that it hydrolyzes faster, is formed when H hydrolyzes in water. This material is probably H·1TDG but it was not isolated. Approximately 5 to 8 per cent of the original H is converted to this sulfonium salt. 3. The hydrolysis constant of M/100 H·2TDG has been determined at 20°, 25.5°, 37°, 75°, and 100°C., a temperature coefficient, Q10, of 3–4 was obtained. The effect of temperature is in agreement with that predicted by the Arrhenius equation. An activation energy of 26,000 calories was calculated.

A STUDY OF THE MECHANISM AND KINETICS OF THE SULPHITE PROCESS

1939 ◽  
Vol 17b (4) ◽  
pp. 121-132 ◽  
Author(s):  
J. M. Calhoun ◽  
F. H. Yorston ◽  
O. Maass
Keyword(s):  
Temperature Coefficient ◽  
Arrhenius Equation ◽  
Practical Interest ◽  
Effect Of Temperature ◽  
Wood Meal ◽  
Spruce Wood ◽  
Mechanism And Kinetics ◽  
Kinetics Of

The rate of delignification of resin extracted spruce wood-meal has been determined in calcium-base sulphite liquor at temperatures from 130 °C. down to 50 °C. No break was found in the temperature coefficient curve at the lower temperatures, the reaction following the Arrhenius equation closely. Possible mechanisms of the reaction are discussed in the light of existing theories, and the effect of temperature on the yield of pulp is pointed out for its practical interest.

Effect of Temperature on Dynamic Viscosity and Activation Energy of Milk and Acidophilus Milk

2014 ◽  
Vol 1059 ◽  
pp. 53-59
Author(s):  
Peter Hlaváč ◽  
Monika Božiková
Keyword(s):  
Activation Energy ◽  
Dynamic Viscosity ◽  
Arrhenius Equation ◽  
Viscosity Measurement ◽  
Effect Of Temperature ◽  
Rheological Parameters ◽  
Physical Parameters ◽  
Measured Temperature ◽  
Regression Equations ◽  
Increasing Functions

This article is focused on temperature dependencies of rheological parameters as the dynamic viscosity and activation energy of milk and acidophilus milk. Viscosity measurement was performed using a single-spindle viscometer. The relations of dynamic viscosity and activation energy in the temperature range 5–25 oC for milk and acidophilus milk were measured. The relations of all physical parameters of milk to temperature showed the influence of relative fat content. The effect of temperature on milk and acidophilus milk parameters is shown in Fig. 1–4. In the measured temperature interval, dynamic viscosities of milk ranged between 2.0 mPa.s and 1.3 mPa.s, and of acidophilus milk between 443.4 mPa.s and 244.1 mPa.s. Measured relations of dynamic viscosity for milk and acidophilus milk during temperature stabilisation had an exponential decreasing progress (Fig. 1–2), which is in accordance with Arrhenius equation. Temperature dependencies of activation energy are described by linear increasing functions (Fig. 3–4). Obtained values of activation energy were in the range 356.97–1267.70 J/mol for milk and in the range 615.94–2129.96 J/mol for acidophilus milk. The mathematical description of the dependencies is summarised by regression equations 2 and 3. Coefficients of regression equations and coefficients of determination approximately in the range 0.984–0.999 are presented in Table 1.

A Study on the Rheological Properties of Low-Density Polyethylene/Palm Kernel Shell Composites

2012 ◽  
Vol 626 ◽  
pp. 615-619 ◽  
Author(s):  
B.Y. Lim ◽  
Salmah Husseinsyah ◽  
Pei Leng Teh
Keyword(s):  
Activation Energy ◽  
Rheological Properties ◽  
Arrhenius Equation ◽  
Palm Kernel ◽  
Testing Temperature ◽  
Filler Loading ◽  
Low Density Polyethylene ◽  
Effect Of Temperature ◽  
Low Density ◽  
Palm Kernel Shell

The rheological properties of the low density polyethylene (LDPE)/palm kernel shell (PKS) composites were studied by using a melt flow indexer. The silane treated and untreated composites were investigated. Both of the composites were further varied by amount of filler loading from 10 to 40 php. The testing temperature of composites varied from 180 to 210 °. It was found out that the MFI values of the composites increased with temperature but decreased with a rise of filler loading. The treated LDPE/PKS composites exhibited lower MFI values compared to untreated composites, which indicated the increase of viscosity. Thus, a better adhesion between the LDPE matrix and PKS was established. The effect of temperature on the viscosity of LDPE/PKS composites was found to obey the Arrhenius equation. The results showed that the activation energy of the composites increased with the increase of filler loading. However, at similar filler loading, the silane treated composites showed lower activation energy compared to untreated composites, leading to the reduction of their temperature sensitivity.

Effect of temperature on the rheological behavior of sugary cassava

2020 ◽  
pp. 125
Author(s):  
Leiliane do Socorro Sodré Souza ◽  
Tatiane Pereira de Souza ◽  
Rafael Lopes e Oliveira ◽  
Sérgio Duvoisin Junior ◽  
Ari de Freitas Hidalgo ◽  
...  
Keyword(s):  
Activation Energy ◽  
Shear Rate ◽  
Rheological Behavior ◽  
Food Production ◽  
Arrhenius Equation ◽  
Effect Of Temperature ◽  
Rheological Models ◽  
Rate Range ◽  
Fermented Beverages ◽  
Three Samples

The rheological behavior of the juice extracted from sugary cassava roots, a type of cassava that stored the largest amount of sugars and the starch as it was, at various temperatures (9-65ºC) and in concentrations of 5ºBrix, 10.5ºBrix, and 18.5ºBrix. The experiments were performed on a Brookfield viscometer in a shear rate range of 0.01-237.6 s-1. The rheological models of Newton, Bingham, and Ostwald-De-Waele were fitted to the experimental results. The Newton model describes well the rheological behavior of the three samples evaluated. The effect of temperature on viscosity was evaluated using an Arrhenius equation; the viscosity value is influenced by the same temperature. The activation energy values ​​for the concentrations of 5ºBrix, 10.5ºBrix and 18.5ºBrix correspond to 3.14 kcal mol-1, 3.53 kcal mol-1 and 3.71 kcal mol-1. This type of cassava can be used in the production of ethanol, fermented beverages and syrups. It is also an important alternative for food production, as the cultivation of cassava can be classified as less aggressive to the environment, in comparison with sugarcane.

Cr-Substituted Mesoporous Aluminophosphate Molecular Sieve: Synthesis, Characterization, Crystallization Kinetics and Catalytic Activity

2013 ◽  
Vol 316-317 ◽  
pp. 1018-1023
Author(s):  
Xin Zhu Li ◽  
Ji Shi Zhang
Keyword(s):  
Activation Energy ◽  
Catalytic Activity ◽  
Crystal Growth ◽  
Crystallization Kinetics ◽  
Molecular Sieve ◽  
Arrhenius Equation ◽  
Degree Of Crystallinity ◽  
Tert Butylhydroperoxide ◽  
Growth Activation ◽  
Cr Map

Cr-substituted mesoporous aluminophosphate molecular sieve (Cr-MAP) was synthesized and characterized. Crystallization kinetics curves measured as an index to the relative degree of crystallinity, according to the Arrhenius equation to calculate the apparent nucleation activation energy and crystal growth activation energy of Cr-MAP, which was 63.7 and 14.7 kJ• mol-1, respectively. Cr-MAP had highly catalytic activity for fabricating acetophenone by selectively oxizing ethylbenzene. Using tert-butylhydroperoxide as oxidant and chlorobenzene as solvent at 100 °C for 8 h, acetophenone selectivity, acetophenone yield and ethylbenzene conversion reaches 85.4, 62.2 and 72.8 %, respectively.

Diffusion Coefficients of Interest for the Simulation of Heat Treatment in Rare-Earth Transition Metal Magnets

2012 ◽  
Vol 727-728 ◽  
pp. 163-168 ◽  
Author(s):  
Marcos Flavio de Campos
Keyword(s):  
Experimental Data ◽  
Heat Treatment ◽  
Activation Energy ◽  
Rare Earth ◽  
Transition Metal ◽  
Impurity Atom ◽  
Diffusion Coefficients ◽  
Arrhenius Equation ◽  
Atom Diffusion ◽  
Essential Input

In the case of the modeling of sintering and heat treatments, the diffusion coefficients are an essential input. However, experimental data in the literature about diffusion coefficients for rare-earth transition metal intermetallics is scarce. In this study, the available data concerning diffusion coefficients relevant for rare-earth transition metal magnets are reviewed and commented. Some empirical rules are discussed, for example the activation energy is affected by the size of the diffusing impurity atom. Diffusion coefficients for Dy, Nd and Fe into Nd2Fe14B are given according an Arrhenius equation D=D0exp (-Q/RT). For Dy diffusion into Nd2Fe14B, Q 315 kJ/mol and D08 . 10-4m2/s.

scholarly journals Photocatalytic Degradation of Textile Dyeing Wastewater Using Titanium Dioxide and Zinc Oxide

2008 ◽  
Vol 5 (2) ◽  
pp. 219-223 ◽  
Author(s):  
Abbas J. Attia ◽  
Salih H. Kadhim ◽  
Falah H. Hussein
Keyword(s):  
Activation Energy ◽  
Zinc Oxide ◽  
Titanium Dioxide ◽  
Photocatalytic Degradation ◽  
Irradiation Time ◽  
Effect Of Temperature ◽  
Dyeing Wastewater ◽  
Textile Dyeing ◽  
Textile Factory ◽  
Textile Dyeing Wastewater

Photodegradation of a real textile dyeing wastewater taken from Hilla textile factory in Babylon Governorate, Iraq have been investigated. Photocatalytic degradation was carried out over suspensions of titanium dioxide or zinc oxide under ultraviolet irradiation. Photodegradation percentage was followed spectrophometrically by the measurements of absorbance at λmax equal to 380 nm. The rate of photodegradation increased linearly with time of irradiation when titanium dioxide or zinc oxide was used. A maximum color removal of 96% was achieved after irradiation time of 2.5 hours when titanium dioxide used at 303K and 82% color reduction was observed when zinc oxide used for the same period and at the same temperature. The effect of temperature on the efficiency of photodegradation of dyestuff was also studied. The activation energy of photodegradation was calculated and found to be equal to 21 ± 1 kJ mol-1 on titanium dioxide and 24 ± 1 kJ mol-1 on zinc oxide.

scholarly journals Effect of temperature on toxicity of selected insecticides to forest beetle Anoplotrupes Stercorosus / Interakcja temperatury z wybranymi insektycydami chrząszcza leśnego Anoplotrupes stercorosus

2013 ◽  
Vol 18 (1-2) ◽  
pp. 103-108 ◽  
Author(s):  
Bartosz Piechowicz ◽  
Przemysław Grodzicki
Keyword(s):  
Temperature Coefficient ◽  
Positive Temperature Coefficient ◽  
Effect Of Temperature ◽  
Positive Temperature ◽  
Benzoyl Urea ◽  
The Impact

Abstract In 2007 and 2008 research on the impact of temperature, ranging from 14 to 39°C on the survivability of an adult Anoplotrupes stercorosus intoxicated by insecticide preparations from the group of phosphoorganic insecticides (diazinon), carbamate (pirimicarb), quinazolines (fenazaquin), oxadiazine (indoxacarb), benzoyl urea insecticides (teflubenzuron), neonicotinoids (acetamiprid) and pyrethroids (beta-cyfluthrin) was carried out. The results obtained indicate that all preparations used in tests had a positive temperature coefficient.

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