6.1. Molecular Vibrations PR58 6.2. Molecular Internal Rotations PR58 6.3. Chemical Reactions PR58 7. Dynamical Variants PR62 7.1. Quantum Fluid Density Functional Theory PR62 7.2. Atom-Field Interactions PR62 7.3. Ion-Atom Collisions PR62 7.4. Chemical Kinetics PR62 8. Spin Dependent Generalizations PR63 8.1. {N, Ns, v(r b)} Representation PR63 8.2. {NR, N , v(r b)} Representation PR64 9. Conclusions PR65 10. Abbreviations and Symbols of Some Important Subjects/Quantities PR

Update 2 of: Electrophilicity Index

Impacts of shrimp farming in Bangladesh: Challenges and alternatives

Conceptual density functional theory provides a method for analyzing the chemical reactivity in terms of different global reactivity descriptors including electrophilicity and their local counterparts like philicity. These concepts’ definitions and various applications that demonstrate their interpretive power are discussed. Global and local electrophilicities are able to account for a wide variety of chemical phenomena.

Electrophilicity index within a conceptual DFT framework

The frozen food export sector, next to readymade garments sector, is the second largest export earner of Bangladesh. Shrimp, main item of frozen food, is a major contributor in the national economy of Bangladesh since mid 1980s. Although it provides millions of employment and earns more than US$ 445 million annually, it has been facing a host of challenges. Shrimp farming has been associated with a number of negative environmental and social impacts which hinder the sustainable development of this blooming sector. This paper aim to focus on how the shrimp culture in Bangladesh is affecting the adjacent environment as well as society and management approach for it’s sustain ability by means of reviewing the available scientific literatures. It finds the grave socioeconomic impacts including traditional livelihood displacement, loss of land security, food insecurity, marginalization, rural unemployment, social unrest and conflicts in the wake of shrimp culture development in Bangladesh. Similarly, environmental impacts such as mangrove degradation, loss of biodiversity, sedimentation, saltwater intrusion, and pollution and disease outbreaks are found to be the main obstacles for the development of sustainable shrimp farming. Inappropriate management practices and inadequate plans regarding water quality, seed supply, irrigation facilities and fishery resources are the main reasons for these impacts of shrimp farming. The effective management measures to mitigate the adverse environmental impact of shrimp farming development have now become urgent requirement.

Impacts of shrimp farming on the coastal environment of Bangladesh and approach for management

A comprehensive review of quantitative structure-activity relationships (QSAR) allowing the prediction of the fate of organic compounds in the environment from their molecular properties was done. The considered processes were water dissolution, dissociation, volatilization, retention on soils and sediments (mainly adsorption and desorption), degradation (biotic and abiotic), and absorption by plants. A total of 790 equations involving 686 structural molecular descriptors are reported to estimate 90 environmental parameters related to these processes. A significant number of equations was found for dissociation process (pKa), water dissolution or hydrophobic behavior (especially through the KOW parameter), adsorption to soils and biodegradation. A lack of QSAR was observed to estimate desorption or potential of transfer to water. Among the 686 molecular descriptors, five were found to be dominant in the 790 collected equations and the most generic ones: four quantum-chemical descriptors, the energy of the...

/pdf/prediction-of-the-fate-of-organic-compounds-in-the-5deim1z4tc.pdf

Prediction of the fate of organic compounds in the environment from their molecular properties: a review.

Assessing prospects for shrimp culture in the Indian Sundarbans: A combined simulation modelling and choice experiment approach

The Bronsted and Lowry acid–base theory is based on the capacity of proton donation or acceptance (in the presence/absence of a solvent) whereas the Lewis acid–base theory is based on the propensity of electron pair acceptance or donation. We explore through DFT calculation the obvious question whether these two theories are in conformity with each other. We use p K a as the descriptor for the Bronsted and Lowry acidity. The DFT descriptors like ionization potential, electron affinity, electronegativity, hardness and global electrophilicity are computed for 58 organic and inorganic acids. The fractional electron transfer, Δ N and the associated energy change, Δ E for the reaction of these acids with trimethyl amine (a strong base) are used as the possible descriptors for the Lewis acidity. A near exponential decrease in Δ N and (−Δ E ) values is observed in general with an increase in p K a values. The findings reveal that a stronger Bronsted acid in most cases behaves as a stronger Lewis acid as well. However, it is not necessarily true for all acids.

Are strong Brønsted acids necessarily strong Lewis acids

The Broensted and Lowry acid base theory is based on the capacity of proton donation or acceptance (in the presence or absence of a solvent) whereas the Lewis acid base theory is based on the propensity of electron pair acceptance or donation. We explore through DFT calculation the obvious question whether these two theories are in conformity with each other. We use pKa as the descriptor for the Broensted and Lowry acidity. The DFT descriptors like ionization potential, electron affinity, electronegativity, hardness and global electrophilicity are computed for 58 organic and inorganic acids. The fractional electron transfer, del(N) and the associated energy change, del(E) for the reaction of these acids with trimethyl amine (a strong base) are used as the possible descriptors for the Lewis acidity. A near exponential decrease in del(N) and (-del(E)) values is observed in general with an increase in pKa values. The findings reveal that a stronger Broensted acid in most cases behaves as a stronger Lewis acid as well. However it is not necessarily true for all acids.

Are Strong Bronsted Acids Necessarily Strong Lewis Acids

We consider an urban foreign enclave with sector-specific foreign capital in an otherwise mobile-capital Harris-Todaro model. We consider the taxation of foreign capital. A dynamic version of this model is considered. The long-run equilibrium and the comparative steady-state effects are analyzed. We get some interesting effects of reduction in tax rate on foreign capital on the short-run and the long-run equilibrium levels of domestic factor income and national income under some meaningful conditions.

Foreign enclaves and economic development: A theoretical analysis

In this paper we make a dynamic analysis of the effects of various tax policies on the unemployment of an economy with a labour-efficiency function which shifts over time. Stock of knowledge, which is produced as a durable public good, accumulates over time; and the efficiency of the worker varies positively with the stock of knowledge in addition to wage and unemployment. We analyze the accumulation of physical capital and human capital stock (stock of knowledge) and the properties of long-run equilibrium of the system. The comparative steady-state effects on unemployment with respect to change in various tax rates are analyzed assuming that the production of the public good (educational output) is financed by the tax revenue. In many cases, these results are different from the corresponding comparative static results.

/pdf/tax-policies-and-unemployment-in-a-dynamic-efficiency-wage-uv9ykdlwbl.pdf

Kausik Gupta

Papers

Assessing prospects for shrimp culture in the Indian Sundarbans: A combined simulation modelling and choice experiment approach

Are strong Brønsted acids necessarily strong Lewis acids

Are Strong Bronsted Acids Necessarily Strong Lewis Acids

Foreign enclaves and economic development: A theoretical analysis

Tax Policies and Unemployment in a Dynamic Efficiency Wage Model