The role of activation enthalpy modeled with a modified Arrhenius equation in a variant of a minimal bromate oscillator for temperatures changes

2021 ◽  
pp. 111165
Author(s):  
M.A. Morales ◽  
A. Anzo ◽  
A. Luna-Flores ◽  
A.M. Cervantes T. ◽  
A.A. Hernández
Keyword(s):  
Arrhenius Equation ◽  
Activation Enthalpy

Kinetic Studies on the Polymerization of Dicyclohexylmethylmethane-4,4'-Diisocyanate with Polyoxytetramethylene Diol

2013 ◽  
Vol 791-793 ◽  
pp. 32-35
Author(s):  
Jian Cheng Wang
Keyword(s):  
Rate Constant ◽  
Arrhenius Equation ◽  
Activation Enthalpy ◽  
Kinetic Studies ◽  
Activation Entropy ◽  
Dimethyl Acetamide ◽  
Different Temperatures ◽  
Ft Ir ◽  
Temperature Activation

Dicyclohexylmethylmethane-4,4'-diisocyanate is used to react with polyoxytetramethylene diol at different temperatures. N,N-Dimethyl acetamide is used as solvent.In situFT-IR is used to monitor the reaction to work out rate constant, Arrhenius equation and Eyring equation. The polymerization has been found to be a second order reaction, and the rate constant increases with the rise of temperature. Activation energy (Ea), activation enthalpy (ΔH) and activation entropy (ΔS) for the polymerization are respectively calculated out, which are very useful to reveal the reaction mechanism.

scholarly journals The role of hazardous factors of chemical and physical nature in welders’ occupational risks management

2021 ◽  
Vol 273 ◽  
pp. 12028
Author(s):  
Yuriy Bulygin ◽  
Elena Andreeva ◽  
David Shoniya
Keyword(s):  
Chemical Nature ◽  
Arrhenius Equation ◽  
Physical Nature ◽  
Physical Factor ◽  
Dust Particles ◽  
Occupational Risks ◽  
Chemical Factors ◽  
Physical And Chemical ◽  
Near Future

The article is devoted to a review of the available scientific approaches to assess the role of hazardous factors of physical and chemical nature, which are very important for the management of occupational risks of workers in dust-hazardous industries using the example of welders. General approaches and models for assessing the risk to public health in general are presented quite fully, the mechanisms of the effect of dust particles on the development of occupational pathologies in welders, including toxic and carcinogenic ones, have been studied in depth, a number of articles are devoted to the study of the effect of a thermal (physical) factor of a chronic nature. The above studies are of a scattered nature, the combined effect of physical and chemical factors are not taken into account, based on the S. Arrhenius equation, which is especially important in the closed spaces of the working area. There is no comprehensive methodology for assessing health risks for workers in dust-hazardous industries and welders. The development of the above-mentioned comprehensive methodology for assessing health risk of workers in dust-hazardous industries based on taking into account hazardous factors of physical and chemical nature is very promising in the near future.

scholarly journals Role of Dielectric Constant on Ion Transport: Reformulated Arrhenius Equation

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Shujahadeen B. Aziz
Keyword(s):  
Dielectric Constant ◽  
Polymer Electrolytes ◽  
Arrhenius Equation ◽  
Dc Conductivity ◽  
Solid Polymer Electrolytes ◽  
Alumina Nanoparticles ◽  
Solid Polymer ◽  
Relaxation Processes ◽  
Linear Behavior

Solid and nanocomposite polymer electrolytes based on chitosan have been prepared by solution cast technique. The XRD results reveal the occurrence of complexation between chitosan (CS) and the LiTf salt. The deconvolution of the diffractogram of nanocomposite solid polymer electrolytes demonstrates the increase of amorphous domain with increasing alumina content up to 4 wt.%. Further incorporation of alumina nanoparticles (6 to 10 wt.% Al2O3) results in crystallinity increase (large crystallite size). The morphological (SEM and EDX) analysis well supported the XRD results. Similar trends of DC conductivity and dielectric constant with Al2O3concentration were explained. The TEM images were used to explain the phenomena of space charge and blocking effects. The reformulated Arrhenius equation (σ(ε′,T)=σoexp(-Ea/KBε′T)) was proposed from the smooth exponential behavior of DC conductivity versus dielectric constant at different temperatures. The more linear behavior of DC conductivity versus1000/(ɛ′×T)reveals the crucial role of dielectric constant in Arrhenius equation. The drawbacks of Arrhenius equation can be understood from the less linear behavior of DC conductivity versus1000/T. The relaxation processes have been interpreted in terms of Argand plots.

Contribution of root respiration to total CO2 efflux from the soil of a deciduous forest

1996 ◽  
Vol 26 (7) ◽  
pp. 1142-1148 ◽  
Author(s):  
Viviane Thierron ◽  
H. Laudelout
Keyword(s):  
Root Respiration ◽  
Arrhenius Equation ◽  
Deciduous Forest ◽  
Soil Layer ◽  
Co2 Efflux ◽  
Temperature Dependent ◽  
Grand Average ◽  
Comparison Of The Results ◽  
Infrared Gas Analyzer

The measurement of CO2 efflux from forest soils has become of great importance in evaluating the role of forests as sequestering agents of atmospheric CO2. In this regard, it is important to know the part of total efflux that originates from root respiration. We have tried to evaluate it by measuring efflux in the field with a portable infrared gas analyzer, while at the same time, the 0–10 cm soil layer was sampled and incubated in the laboratory during 30–40 days. Comparison of field and laboratory measurements was made by conversion to a common temperature (10 °C) using the Arrhenius equation for both processes. Results indicated an Arrhenius apparent activation energy of 25 kcal (1 kcal = 4.1855 kJ) in the field and 15 kcal in the laboratory. Comparison of the results was also made possible by modelling the cumulative CO2 efflux in the laboratory so that we eliminated the initial flush of mineralization, the value of which was temperature dependent. The grand average of CO2 efflux from the forest soil calculated for the whole year from the temperature of the soil and the Arrhenius equation was 70 Mg•ha−1•year−1, of which 90% originated from the roots.

Role of dactinomycin in the improved survival of children with Wilms' tumor

JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 1005-1009 ◽  
Author(s):  
D. J. Fernbach
Keyword(s):  
Wilms Tumor

Role of the allergist in diagnosis and management of patients with uveitis

JAMA ◽  
1966 ◽  
Vol 195 (3) ◽  
pp. 167-172 ◽  
Author(s):  
T. E. Van Metre
Keyword(s):  
Diagnosis And Management

The power of norms to sway fused group members

2018 ◽  
Vol 41 ◽  
Author(s):  
Winnifred R. Louis ◽  
Craig McGarty ◽  
Emma F. Thomas ◽  
Catherine E. Amiot ◽  
Fathali M. Moghaddam
Keyword(s):  
Evolutionary Anthropology ◽  
Normative Systems ◽  
Violent Extremism ◽  
Identity Fusion ◽  
Group Members

AbstractWhitehouse adapts insights from evolutionary anthropology to interpret extreme self-sacrifice through the concept of identity fusion. The model neglects the role of normative systems in shaping behaviors, especially in relation to violent extremism. In peaceful groups, increasing fusion will actually decrease extremism. Groups collectively appraise threats and opportunities, actively debate action options, and rarely choose violence toward self or others.

Elaborating the role of reflection and individual differences in the study of folk-economic beliefs

2018 ◽  
Vol 41 ◽  
Author(s):  
Kevin Arceneaux
Keyword(s):  
Decision Making ◽  
Individual Differences ◽  
Cognitive Processes ◽  
Evolutionary History ◽  
Behavioral Responses ◽  
History Of ◽  
Economic Beliefs

AbstractIntuitions guide decision-making, and looking to the evolutionary history of humans illuminates why some behavioral responses are more intuitive than others. Yet a place remains for cognitive processes to second-guess intuitive responses – that is, to be reflective – and individual differences abound in automatic, intuitive processing as well.

The role of affect in feelings of obligation

2020 ◽  
Vol 43 ◽  
Author(s):  
Stefen Beeler-Duden ◽  
Meltem Yucel ◽  
Amrisha Vaish
Keyword(s):  
Positive Emotions ◽  
The Creation ◽  
Sense Of Obligation

Abstract Tomasello offers a compelling account of the emergence of humans’ sense of obligation. We suggest that more needs to be said about the role of affect in the creation of obligations. We also argue that positive emotions such as gratitude evolved to encourage individuals to fulfill cooperative obligations without the negative quality that Tomasello proposes is inherent in obligations.

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