Methods for Calculating the Process of Chemisorption in Systems with a Moving Front of an Instantaneous Irreversible Reaction

2007 ◽  
Vol 38 (2) ◽  
pp. 135-142
Author(s):  
L. M. Musabekova ◽  
A. M. Brener
Keyword(s):  
Irreversible Reaction ◽  
Moving Front

Empirical model approach for the evaluation of pH and conductivity on pollutant diffusion in soil environment

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Mathematical Model ◽  
Quadratic Equation ◽  
Diffusivity Coefficient ◽  
Soil Environment ◽  
Irreversible Reaction ◽  
Chemical Pollutant ◽  
The Mathematical Model ◽  
Coefficient Of Diffusion ◽  
Level Of Agreement ◽  
Model Approach

This work is aimed at developing a mathematical model equation that can be used to predict the fate of contaminant in the soil environment. The mathematical model was developed based on the fundamental laws of conservation and the equation of continuity given asand was resolved to obtain a quadratic equation of the form C(X) = DX2+vX+f. The developed equation was then used to fit the experimental data that were obtained from the Physio-chemical analysis of the soil samples which were obtained at various depths; within the vicinity of the H & H Asphalt plant Company, located at Enito 3 in Ahoada West L.G.A, River State, Nigeria. The Experimental and Model results obtained from the Calculation and Simulation of the developed models were compared numerically and graphically as presented in this work. It was observed that there is reasonable level of agreement between the three results. The polynomial of the curve was established to ascertain the validity of the model; this was done for all the parameters that were analyzed. From the findings the model developed can be used to predict the concentration of a chemical pollutant at various depths. The reliability of the model developed was established giving the fact that through this quadratic equation the diffusivity (coefficient of diffusion), the water velocity and the irreversible reaction decay rate could be determined.

scholarly journals Enhanced Reversible Zinc Ion Intercalation in Deficient Ammonium Vanadate for High-Performance Aqueous Zinc-Ion Battery

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Quan Zong ◽  
Wei Du ◽  
Chaofeng Liu ◽  
Hui Yang ◽  
Qilong Zhang ◽  
...  
Keyword(s):  
High Performance ◽  
Coulombic Efficiency ◽  
Specific Capacity ◽  
Interlayer Spacing ◽  
Zinc Ion ◽  
Carbon Cloth ◽  
High Specific Capacity ◽  
Irreversible Reaction ◽  
Ammonium Vanadate ◽  
Structure Degradation

AbstractAmmonium vanadate with bronze structure (NH4V4O10) is a promising cathode material for zinc-ion batteries due to its high specific capacity and low cost. However, the extraction of $${\text{NH}}_{{4}}^{ + }$$ NH 4 + at a high voltage during charge/discharge processes leads to irreversible reaction and structure degradation. In this work, partial $${\text{NH}}_{{4}}^{ + }$$ NH 4 + ions were pre-removed from NH4V4O10 through heat treatment; NH4V4O10 nanosheets were directly grown on carbon cloth through hydrothermal method. Deficient NH4V4O10 (denoted as NVO), with enlarged interlayer spacing, facilitated fast zinc ions transport and high storage capacity and ensured the highly reversible electrochemical reaction and the good stability of layered structure. The NVO nanosheets delivered a high specific capacity of 457 mAh g−1 at a current density of 100 mA g−1 and a capacity retention of 81% over 1000 cycles at 2 A g−1. The initial Coulombic efficiency of NVO could reach up to 97% compared to 85% of NH4V4O10 and maintain almost 100% during cycling, indicating the high reaction reversibility in NVO electrode.

Toward a Theory of International Politics

1955 ◽  
Vol 49 (3) ◽  
pp. 733-746 ◽  
Author(s):  
Kenneth W. Thompson
Keyword(s):  
Foreign Policy ◽  
Foreign Relations ◽  
International Politics ◽  
Jet Stream ◽  
Human Relations ◽  
Levels Of Abstraction ◽  
Theoretical Approaches ◽  
Analysis Theory ◽  
Moving Front ◽  
Special Priority

Recently a group of scholars, analysts, and diplomatists met for a weekend conference on theoretical approaches to international politics. Their discussion was inspired by the widespread and growing interest in conceptual and theoretical problems illustrated by parallel efforts in the study of politics, economics, law, and human relations. In the field of foreign relations the impulse toward theory comes from practitioners as well as philosophers. Indeed a former Secretary of State maintains that our most urgent need is for “an applicable body of theory in foreign policy.” Practical men with first-hand diplomatic experience point to the need for rational generalizations and intellectual structures to extract meaning from the jet stream of contemporary events. The intellectual processes by which practical judgments are made along a moving front of events clearly demand inquiry and analysis. Theory in the study of international politics perhaps derserves a special priority because of the urgency of the problem and the stridency of the debate generated by competing approaches each claiming to have preempted the field. Perhaps what is called for is a sorting out and assessment of the intellectual factors that go into diverse theories of international politics at varying levels of abstraction and generality. This sorting out was one of the objectives of the conferees. Similarly this paper seeks to review the nature and purpose of theory, its limitations, and the characteristics of the chief types of theory in international politics.

Spectrochemical Behavior of Carcinogenic Polycyclic Aromatic Hydrocarbons in Biological Systems. Part II: A Theoretical Rate Model for BaP Metabolism in Living Cells

1996 ◽  
Vol 50 (11) ◽  
pp. 1352-1359 ◽  
Author(s):  
Ping Chiang ◽  
Kuang-Pang Li ◽  
Tong-Ming Hseu
Keyword(s):  
Rate Constant ◽  
Living Cells ◽  
Rate Model ◽  
Number Density ◽  
Order Process ◽  
Irreversible Reaction ◽  
First Order ◽  
Metabolism Rate ◽  
Polycyclic Aromatic ◽  
Kinetics Of

An idealized model for the kinetics of benzo[ a]pyrene (BaP) metabolism is established. As observed from experimental results, the BaP transfer from microcrystals to the cell membrane is definitely a first-order process. The rate constant of this process is signified as k1. We describe the surface–midplane exchange as reversible and use rate constants k2 and k3 to describe the inward and outward diffusions, respectively. The metabolism is identified as an irreversible reaction with a rate constant k4. If k2 and k3 are assumed to be fast and not rate determining, the effect of the metabolism rate, k4, on the number density of BaP in the midplane of the microsomal membrane, m3, can be estimated. If the metabolism rate is faster than or comparable to the distribution rates, k2 and k3, the BaP concentration in the membrane midplane, m3, will quickly be dissipated. But if k4 is extremely small, m3 will reach a plateau. Under conditions when k2 and k3 also play significant roles in determining the overall rate, more complicated patterns of m3 are expected.

scholarly journals KINETIKA TRANSPOR Co(II) MELALUI TEKNIK MEMBRAN CAIR FASA RUAH SECARA KONSEKUTIF

2015 ◽  
Vol 3 (1) ◽  
pp. 67
Author(s):  
Riana Dewi ◽  
Admin Alif ◽  
Hermansyah Aziz
Keyword(s):  
Optimum Condition ◽  
Ion Transport ◽  
Intermediate Phase ◽  
Bulk Liquid ◽  
Liquid Membranes ◽  
Kinetic Evaluation ◽  
Irreversible Reaction ◽  
First Order ◽  
Source Phase

 ABSTRACT Determination of kinetic analysis of Co(II) ion transport through bulk liquid membranes by consecutive method have been study. The optimum condition was obtained at pH 4 for the intermediate phase and receiving phase at pH near zero, while the source phase at pH 7, oxine concentration in chloroform at source phase is 2.10 M, methyl red concentration in chloroform at receiving phase is 3.10 M. It was found that Co(II) ion receiving phase at optimum condition as 4.40%. Evaluation of Co(II) ion kinetic transport shows k1 as 0.0116 minutes-1 and k4 0.0113 minutes-1. Kinetic transport process of Co(I1) ion through bulk liquid membranes by consecutive method followed first order consecutive irreversible reaction rate low. Consecutive method can used as an alternative method in determination the optimum condition of metals ion transport and kinetic evaluation of mentioned transport metals ion. Keywords : bulk liquid membranes, consecutive, cobalt

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