11 results on '"Debdutta Chakraborty"'
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2. IMPORTANCE OF PHYSICAL ENVIRONMENT AT WORKPLACE FOR WOMEN STONE CRUSHER INDUSTRY WORKERS IN PAKUR AND BIRBHUM DISTRICTS
- Author
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Debdutta Chakraborty
- Subjects
Physical Environment, Women Workers, Stone Crusher Industry, Liket Scale - Abstract
The extraction of raw materials for infrastructure and construction projects is one of the major contributions made by the stone crushing sector to the economic growth of places like Pakur and Birbhum. Despite the fact that both men and women can find employment in the stone crusher industries, this abstract focuses on the significance of the physical workplace for female stone crusher industry workers in the Pakur and Birbhum areas. The physical workplace environment has a significant impact on how women who work in the stone crushing sector in the Pakur and Birbhum regions perceive their experiences. Stakeholders may empower female employees, improve their well-being, and boost their overall productivity and job satisfaction by offering a welcoming and encouraging environment that includes layout design, ergonomics, safety precautions, and general atmosphere. Such actions will not only help the workforce as a whole but will also advance the stone crushing sector's sustainable growth. Key Words: Physical Environment, Women Workers, Stone Crusher Industry, Liket Scale
- Published
- 2023
- Full Text
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3. Dynamics of Pyrene-Dimer Association and Ensuing Pyrene-Dimer Dissociation
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Hans Lischka, William L. Hase, and Debdutta Chakraborty
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010304 chemical physics ,Dimer ,Intermolecular force ,Nucleation ,010402 general chemistry ,01 natural sciences ,Dissociation (chemistry) ,0104 chemical sciences ,chemistry.chemical_compound ,Reaction rate constant ,chemistry ,Chemical physics ,Molecular vibration ,Intramolecular force ,0103 physical sciences ,Pyrene ,Physical and Theoretical Chemistry - Abstract
To address the possible role of pyrene dimers in soot, chemical dynamics simulations are reported to provide atomistic details for the process of collisional association of pyrene dimers and ensuing decomposition of pyrene dimers. The simulations are performed at 600, 900, 1200, 1600, and 2000 K temperatures (T) with different collisional impact parameters (b; 0-18 A) using the all-atom optimized potentials for liquid simulations intermolecular force field. Corresponding to each b, ensembles of 1000 trajectories are computed up to a maximum time of 110 ps at each T. Microcanonical association rate constants for the pyrene-dimerization processes decrease with an increase in T. The ensuing dissociation of the pyrene dimers is statistical and could be well represented by the Rice-Ramsperger-Kassel-Marcus theory of unimolecular dissociation. Fits of the dissociation rate constants versus the harmonic Rice-Ramsperger-Kassel equation revealed that partial energy randomization occurs among the inter- and intramolecular vibrational modes during the dissociation of pyrene dimers, whereas rotational and translational modes play a significant role. Based on the low probability of association and short lifetime at 1600 (∼13.3 ps) and 2000 (∼12.8 ps) K, it is concluded that pyrene dimers are unlikely to play any major role in soot nucleation processes.
- Published
- 2020
4. Does Confinement Always Lead to Thermodynamically and/or Kinetically Favorable Reactions? A Case Study using Diels-Alder Reactions within ExBox+4 and CB[7]
- Author
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Debdutta Chakraborty, Ranjita Das, and Pratim Kumar Chattaraj
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Ethylene ,010405 organic chemistry ,Kinetics ,Thermodynamics ,010402 general chemistry ,Kinetic energy ,01 natural sciences ,Decomposition ,Atomic and Molecular Physics, and Optics ,Cycloaddition ,0104 chemical sciences ,chemistry.chemical_compound ,Reaction rate constant ,chemistry ,Computational chemistry ,Density functional theory ,Physical and Theoretical Chemistry ,Natural bond orbital - Abstract
The impact of geometrical confinement on the thermodynamic as well as kinetic aspects of a model cycloaddition reaction in between 1, 3 butadiene and ethylene have been investigated by carrying out density functional theory based calculations. To this end, two organic hosts, ExBox+4 and Cucurbit[7]uril (CB[7]) have been utilized to impose the effect of confinement on the reactants, transition state (TS) and product involved in the reaction. Results suggest that the shape of the host and thereby the nature of confining regime dictates the thermodynamic outcome of the studied reaction. The reaction becomes thermodynamically more spontaneous inside CB[7] as compared to ExBox+4 and that in the 'unconfined' gaseous state. Also the rate constant associated with the reaction increases manifold inside CB[7]. Atoms-in a-Molecule, non-covalent interaction, natural bond orbital as well as energy decomposition analyses suggest that the close geometrical proximity of the reactants inside CB[7] as well as extra stabilization of the TS in the encapsulated state may dictate the outcome.
- Published
- 2017
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5. Bonding, Reactivity, and Dynamics in Confined Systems
- Author
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Pratim Kumar Chattaraj and Debdutta Chakraborty
- Subjects
Rare gas ,Quantization (physics) ,Slow reactions ,Atomic orbital ,Chemical physics ,Covalent bond ,Chemistry ,Direct consequence ,Physical and Theoretical Chemistry ,Electronic energy - Abstract
Confined systems often exhibit unusual behavior regarding their structure, stability, reactivity, bonding, interactions, and dynamics. Quantization is a direct consequence of confinement. Confinement modifies the electronic energy levels, orbitals, electronic shell filling, etc. of a system, thereby affecting its reactivity as well as various response properties as compared to the cases of corresponding unconfined systems. Confinement may force two rare gas atoms to form a partly covalent bond. Gas storage is facilitated through confinement and unprecedented optoelectronic properties are observed in certain cases. Some slow reactions get highly accelerated in an appropriate confined environment. In the current Feature Article we analyze these aspects with a special emphasis on the work done by our research group.
- Published
- 2019
6. Confinement induced catalytic activity in a Diels-Alder reaction: comparison among various CB[n], n = 6–8, cavitands
- Author
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Manas Ghara, Pratim Kumar Chattaraj, and Debdutta Chakraborty
- Subjects
Ethylene ,Enzyme catalyzed ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Cavitand ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,Catalysis ,0104 chemical sciences ,Computer Science Applications ,Inorganic Chemistry ,chemistry.chemical_compound ,Computational Theory and Mathematics ,Physical and Theoretical Chemistry ,Diels–Alder reaction - Abstract
The impact of the size of the confining regime on the thermodynamic and kinetic outcome of a representative Diels-Alder reaction between ethylene and 1,3 butadiene has been investigated in silico. To this end, two organic hosts namely cucurbit[6]uril (CB[6]) and cucurbit[8]uril (CB[8]) have been considered in order to impose confinement on the reactants/transition state/product of the concerned reaction. The obtained results have been compared with the recently reported (Chakraborty et al. ChemPhysChem 18:2162-2170, 2017) corresponding case of the same reaction happening inside cucurbit[7]uril (CB[7]). Results indicate that as compared to the reaction of ethylene and 1,3 butadiene inside CB[7], both CB[6] and CB[8] cavitands slow down the same reaction at 298.15 K and 1 atm. It appears that the size of the cavitand plays a crucial role in affecting the kinetic outcome of the considered reaction. While CB[7] can enforce productive alignment of the reactants inside its cavity thereby facilitating the reaction, neither CB[6] nor CB[8] can perform the same task as effectively. This situation bears qualitative resemblance with the cases of enzyme catalyzed reactions.
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- 2018
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7. Density dynamics in some quantum systems
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Munmun Khatua, Pratim Kumar Chattaraj, and Debdutta Chakraborty
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Physics ,Quantum phase transition ,Quantum geometry ,Quantum dynamics ,Quantum phases ,Condensed Matter Physics ,Quantum number ,Atomic and Molecular Physics, and Optics ,Quantum chaos ,Quantum mechanics ,Quantum process ,Physics::Atomic Physics ,Physical and Theoretical Chemistry ,Quantum dissipation - Abstract
The quantum domain behavior of classical nonintegrable systems is well-understood by the implementation of quantum fluid dynamics and quantum theory of motion. These approaches properly explain the quantum analogs of the classical Kolmogorov–Arnold–Moser type transitions from regular to chaotic domain in different anharmonic oscillators. Field-induced tunneling and chaotic ionization in Rydberg atoms are also analyzed with the help of these theories. Quantum fluid density functional theory may be used to understand different time-dependent processes like ion-atom/molecule collisions, atom-field interactions, and so forth. Regioselectivity as well as confined atomic/molecular systems and their reactivity dynamics have also been explained. © 2013 Wiley Periodicals, Inc.
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- 2013
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8. Possible sequestration of polar gas molecules by superhalogen supported aluminum nitride nanoflakes
- Author
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Pratim Kumar Chattaraj and Debdutta Chakraborty
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Chemistry ,Chemical polarity ,Organic Chemistry ,Context (language use) ,02 engineering and technology ,Nitride ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Computer Science Applications ,Inorganic Chemistry ,Adsorption ,Computational Theory and Mathematics ,Covalent bond ,Chemical physics ,Computational chemistry ,Molecule ,Density functional theory ,Physical and Theoretical Chemistry ,0210 nano-technology ,Natural bond orbital - Abstract
The feasibility of having MF3 (where M = Rh, Ir, Pd, Pt, Ag, Au) supported AlN nanoflakes (AlNF) was investigated through density functional theory based calculations. The thermodynamic analysis reveals that the superhalogen MF3 molecules can bind with the host AlNF in a thermodynamically favorable way. The nature of interaction in between the metal centers and the host is of partly covalent type whereas the F centers bind with the host in a non-covalent fashion as vindicated by natural bond orbital and atoms-in a-molecule analyses. An ab initio molecular dynamics study carried out at 298 K temperature confirms the stability of the MF3@AlNF moieties in a dynamical context. The MF3 guests can reduce the HOMO-LUMO gaps of the host nanoflakes. In general, the MF3@AlNF complexes can sequestrate polar adsorbates such as CO, NO, and H2O in a thermodynamically favorable way in most of the cases. An ab initio molecular dynamics calculation illustrates that the MF3@AlNF can adsorb the chosen representative polar molecules in a more favorable way as compared to the corresponding adsorption scenario in the case of pristine AlNF.
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- 2016
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9. In quest of a superhalogen supported covalent bond involving a noble gas atom
- Author
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Pratim Kumar Chattaraj and Debdutta Chakraborty
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Electron density ,Transition metal ,Computational chemistry ,Chemistry ,Covalent bond ,Atom ,Noble gas ,Charge density ,Physical chemistry ,Density functional theory ,Physical and Theoretical Chemistry ,Bond energy - Abstract
The possibility of having neutral Xe-bound compounds mediated by some representative transition metal fluorides of general formula MX3 (where M=Ru, Os, Rh, Ir, Pd, Pt, Ag, Au and X=F) has been investigated through density functional theory based calculations. Nature of interaction between MX3 and Xe moieties has been characterized through detailed electron density, charge density and bond energy decomposition analyses. The feasibility of having compounds of general formula XeMX3 at 298 K has been predicted through thermodynamic considerations. The nature of interaction in between Xe and M atoms is partly covalent in nature and the orbital interaction is the dominant contributor toward these interactions as suggested by energy decomposition analysis.
- Published
- 2015
10. Is there any role of mast cell density and microvessel density in cervical squamous cell carcinoma? A histologic study with special reference to CD-34 immunomarker staining
- Author
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Santosh Kumar Mondal, Senjuti Dasgupta, Debdutta Chakraborty, Shankha Chatterjee, and Palash Mandal
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squamous cell carcinoma ,Pathology ,medicine.medical_specialty ,business.industry ,Angiogenesis ,Carcinoma in situ ,Cell ,Mast cell ,medicine.disease ,Staining ,medicine.anatomical_structure ,Oncology ,Tumor progression ,cervix ,Pediatrics, Perinatology and Child Health ,immunohistochemistry ,medicine ,cardiovascular system ,Immunohistochemistry ,Original Article ,business ,mast cell ,Cervix - Abstract
Background: Mast cells are involved in induction of angiogenesis in the early-stages of tumor development and in modulating blood vessel growth in the later stages of tumor progression. Aims and Objectives: This study was carried out to evaluate the association between mast cell density (MCD) and microvessel density (MVD) in carcinoma in situ (CIS), microinvasive carcinoma (CA) and invasive squamous cell CA of cervix. Materials and Methods: Six cases of CIS, four cases of microinvasive CA and 38 cases of invasive CA were studied over a period of 2 years from August, 2011 to June, 2013. Ten control samples were included in the study. Routine histologic examination was done. Toluidine blue stain was used for MCD determination. Immunohistochemical analysis with CD-34 was done for assessing MVD. Student′s t-test was used to calculate the statistical significance of MCD and MVD. Results: Both MCD and MVD increased from normal samples through CIS to invasive cervical CA. In the four cases of microinvasive CA, the MCD and MVD were more than that of the control samples, but less than that of the six cases of CIS. Conclusion: There is a correlation between mast cell accumulation and angiogenesis in CIS, microinvasive CA and invasive cervical squamous cell CA. MCD and MVD in invasive CA exceed those in CIS and microinvasive CA. It gives us an opportunity to postulate that therapeutic strategies against mast cell mediators and angiogenesis may be of benefit in patients of early-stage cervical CA.
- Published
- 2014
11. A Perspective on the so-called Dual Descriptor
- Author
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Chermette, Henry, Merzoud, Lynda, Guégan, Frédéric, MORELL, Christophe, Chermette, Henry, and Pratim Kumar Chattaraj, Debdutta Chakraborty
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[CHIM] Chemical Sciences - Published
- 2021
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