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Journal of Natural gas Chemistry 2007年第3期16卷 217-226页

作者： g.r.dey radiation and Photochemistry Division Bhabha Atomic Research CentreTrombayMumbai 400085India

The chemical reduction of CO2 remains a challenge with respect to the reversal of the oxidative degradation of any organic materials. The conversion of CO2 into useful substances is essential in developing alternative fuels and various raw materials for different industries. This also aids in preventing the continuous rise in tropospheric temperature due to the green house effect of CO2. In this article an overview of the growth taken place so far in the field of CO2 chemical reduction is pre- sented. The discussion comprises of photochemical methods for the development of different products, viz. CO, CH3OH and CH4, through chemical reduction of CO2. This includes the use of photo catalysts, mainly TiO2, and the role of a hole scavenger （such as 2-propanol） for this purpose.

关键词： CO2 chemical reduction H2 CH4 CO TiO2 hole scavenger photolysis

Approach for C_(1)to C_(2)products commencing from carbon dioxide:A brief review

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Petroleum 2024年第3期10卷 373-398页

作者： g.r.dey radiation and Photochemistry Division Bhabha Atomic Research CentreTrombayMumbai 400085India Homi Bhabha National Institute AnushaktinagarMumbai 400094India

The carbon dioxide(CO_(2))conversion to useable compounds remains a great contest to scientists,engineers,and environmentalists with regard to the reverse of the oxidative degradation of *** conversion is essential for the development of complementary fuels and raw materials for various industries,which in turn will help in avoiding the drastic increase in tropospheric temperature due to greenhouse effect leading to global *** solar energy is the earth's essential power source along with the other various forms of energy for example fossil fuels,hydropower,wind,and biomaterials,*** final goal is to establish the artificial photosynthesis,which can be replicated thru various chemical reduction techniques of CO_(2)by employing appropriate photo-,thermal-and electro-catalysts in order to produce different one carbon atom(C_(1))and higher carbon atoms containing ***,the utilization of clean and sustainable CO_(2)towards high-value products is of great interest today due to the recognized environmental worries and subsequent lessening of the fossil fuels utilization load to meet the energy demand of *** way,solar energy can directly and/or indirectly be altered and stored in chemical energy form for industrial as well as societal *** this article our endeavor is to summarize the advances in CO_(2)chemical reduction research area till date especially in free radical-based methods such as electrochemical,photochemical and plasma chemical for the development of carbon species up to two carbon(C_(2))atoms containing products perceived in the chemical reduction of CO_(2).The author hopes that this piece of work will be helpful to researchers and readers who are focused on the field of CO_(2).

关键词： Photocatalysis Electrocatalysis Plasmolysis Thermolysis Carbon dioxide Chemical reduction

Approach for C1 to C2 products commencing from carbon dioxide: A brief review

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Petroleum 2024年第3期 373-398页

作者： g.r.dey radiation and Photochemistry Division Bhabha Atomic Research Centre Homi Bhabha National Institute

The carbon dioxide（CO2） conversion to useable compounds remains a great contest to scientists, engineers,and environmentalists with regard to the reverse of the oxidative degradation of organics. This conversion is essential for the development of complementary fuels and raw materials for various industries, which in turn will help in avoiding the drastic increase in tropospheric temperature due to greenhouse effect leading to global warming. The solar energy is the earth's essential power source along with the other various forms of energy for example fossil fuels, hydropower, wind, and biomaterials, etc. The final goal is to establish the artificial photosynthesis, which can be replicated thru various chemical reduction techniques of CO2by employing appropriate photo-, thermal-and electro-catalysts in order to produce different one carbon atom（C1） and higher carbon atoms containing products. Besides, the utilization of clean and sustainable CO2towards high-value products is of great interest today due to the recognized environmental worries and subsequent lessening of the fossil fuels utilization load to meet the energy demand of mankind. This way, solar energy can directly and/or indirectly be altered and stored in chemical energy form for industrial as well as societal applications. In this article our endeavor is to summarize the advances in CO2chemical reduction research area till date especially in free radical-based methods such as electrochemical, photochemical and plasma chemical for the development of carbon species up to two carbon（C2） atoms containing products perceived in the chemical reduction of CO2. The author hopes that this piece of work will be helpful to researchers and readers who are focused on the field of CO2.

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Few-shot learning for screening 2D ga2CoS4-x supported single-atom catalysts for hydrogen production

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Journal of Energy Chemistry 2025年第1期100卷 665-673页

作者： Nabil Khossossi Poulumi dey Department of Mechanical Engineering (ME) Delft University of Technology

Hydrogen generation and related energy applications heavily rely on the hydrogen evolution reaction（HEr）,which faces challenges of slow kinetics and high *** electrocatalysts,particularly single-atom catalysts （SACs） on two-dimensional （2D） materials,are *** study presents a few-shot machine learning （ML） assisted high-throughput screening of 2D septuple-atomic-layer ga2CoS4-xsupported SACs to predict HEr catalytic ***,density functional theory （DFT）calculations showed that 2D ga2CoS4is inactive for ***,defective ga2CoS4-x（x=0–0.25）monolayers exhibit excellent HEr activity due to surface sulfur vacancies （SVs）,with predicted overpotentials （0–60 mV） comparable to or lower than commercial Pt/C,which typically exhibits an overpotential of around 50 m V in the acidic electrolyte,when the concentration of surface SV is lower than 8.3%.SVs generate spin-polarized states near the Fermi level,making them effective HEr *** demonstrate ML-accelerated HEr overpotential predictions for all transition metal SACs on 2D *** DFT data from 18 SACs,an ML model with high prediction accuracy and reduced computation time was *** intrinsic descriptor linking SAC atomic properties to HEr overpotential was *** study thus provides a framework for screening SACs on 2D materials,enhancing catalyst design.

关键词： Hydrogen production Electrocatalyst 2D material Density functional theory Machine learning Surface sulfur vacancy

Photolysis studies on HCOOH and HCOO^- in presence of TiO_2 photocatalyst as suspension in aqueous medium

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Journal of Natural gas Chemistry 2009年第1期18卷 50-54页

作者： g. r. dey K. N. r. Nair K. K. Pushpa radiation and Photochemistry Division Bhabha Atomic Research Centre Trombay Mumbai 400 085 India

Photolysis studies on formic acid （HCOOH） and formate ion （HCOO-） in presence of TiO2, a photocatalyst, as suspension in water were carried out separately using 350 nm ultraviolet light. The products, such as H2, CO, CO2 and CH4, generated during the experiments were monitored with varying the ambient, light exposure time, and the concentration of HCOOH/HCOO-. The yields of CO in all these systems increased with light exposure time. In aerated systems, CO yields were higher in contrast to the deoxygenated （Ar-purged） systems under identical conditions. It is proposed apparently that the formation of CO is taking place during the chemical reduction of in-situ generated CO2, a photo-mineralized product of HCOOH/HCOO-, but not through the direct photodecomposition or photodehydration （CO＋H2O） of solute molecules. The rates of CO formation during 1.3 M HCOOH photolysis in presence of TiO2 photocatalyst were evaluated to be 0.21 and 0.13 μl/min in aerated and Ar-purged systems, respectively. As compared with HCOOH systems, the CO yields are lower when 0.2 M HCOONa was exposed to light under identical conditions. The CO growth rates were evaluated to be 0.07 and 0.046 μl/min^-1 for aerated and deoxygenated HCOONa systems, respectively; moreover, the trend is quite similar to that of the HCOOH system. Under these conditions, the emission of H2 was also observed, and its yield was significantly higher in Ar-purged system as compared with the CO yields. However, in aerated system, the yields of these products were just opposite. The formation of low yield of methane was observed during photolysis of HCOOH/HCOO ions. In CO2 ambient, the yields of CO and H2 varied drastically with time.

关键词： formic acid formate ion photolysis TiO2

Effect of a less permeable stronger soil layer on the stability of non-homogeneous unsaturated slopes

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Frontiers of Structural and Civil Engineering 2020年第6期14卷 1462-1475页

作者： Nabarun dey Aniruddha SENgUPTA Department of Civil Engineering Indian Institute of Technology KharagpurKharagpur 721302India

Slope failure occurs due to an increase in the saturation level and a subsequent decrease in matric suction in unsaturated *** paper presents the results of a series of centrifuge experiments and numerical analyses on a 55°inclined unsaturated sandy slope with less permeable,stronger silty sand layer inclusion within *** is observed that a less permeable,stronger silty sand layer in an otherwise homogeneous sandy soil slope hinders the infiltration of *** water content of the slope just above the stronger layer increases significantly,compared to *** shear band is found to initiate in a homogeneous sandy soil slope,whereas for a non-homogeneous slope,they initiate just above the less pervious,stronger layer.A discontinuity of the shear zone is also observed for the case of a non-homogeneous soil *** factor of safety of a non-homogeneous,unsaturated soil slope decreases because of the less permeable,stronger *** decreases significantly if this less permeable,stronger soil layer is located near the toe of the slope.

关键词： non-homogeneous slope stronger soil layer factor of safety centrifuge model test unsaturated soils

Texture Evolution and Ultrafine grain Formation in Cross-Cryo-rolled Zircaloy-2

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Acta Metallurgica Sinica(English Letters) 2015年第7期28卷 837-846页

作者： Sunkulp goel r.Jayaganthan I.V.Singh D.Srivastava g.K.dey N.Saibaba Department of Metallurgical and Materials Engineering Centre of Nanotechnology Department of Mechanical and Industrial Engineering Materials Science Division Bhabha Atomic Research Center Nuclear Fuel Complex Limited

The texture and mechanical properties of cross-rolled zircaloy-2 at 77 and 300 K were *** at 77 K was performed to impart different thickness reductions of 25% and 50%,while at 300 K with 25%,50%,75% and 85% reductions to the *** analysis of deformed sample showed that near-basal orientation is not deformed completely after 50% rolling *** activation of prismatic silp,{1122} contraction twin and {1012} extension twin were evident from the deformed microstructure at 77 *** propensity for activation of basal slip〈a〉 at77 K was also *** deformation of the sample at 300 K occurs by prismatic,basal 〈a〉 and pyramidal 〈c＋a〉slips,which were predicted by pole *** annealing,the tensile strengths（735 and 710 MPa） are almost the same for 50% cryo-cross-rolled and room-temperature cross-rolled zircaloy-2 with almost 2.7% difference in their *** analysis of the deformed samples was made to estimate the stored strain energy and dislocation *** of deformed sample at 673 K for 30 min results in recrystallization,which leads to the formation of ultrafine grains.

关键词： Cross-rolling EBSD TEM Ultrafine grains Texture

A theoretical study on the elastic deformation of cellular phase and creation of necrosis due to the convection reaction process inside a spherical tumor

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International Journal of Biomathematics 2016年第6期9卷 273-306页

作者： Bibaswan dey g. P. raja Sekhar Department of MathematicsIndian Institute of Technology Kharagpur Kharagpur 721302 West Bengal India

Several biological processes, such as convective nutrient transport and convective drug delivery in biological tissues involves the transvascular and interstitial movement of biofluids. This work addresses transvascular and interstitial transport of nutrient inside a spherical tumor. Most of the biological tissues behave like deformable porous materiM and show mechanical behavior towards the fluid motion, due to the fact, that the forces like the drag, which is associated with fluid flow may compress the tissue material. On the macroscopic level, transport of solutes like nutrients, drug molecules, etc. within the tumor interstitial space is modeled. The hydrodynamic problem is treated with biphasic mixture theory under steady state and spherically symmetry situation. The transvascular transport of nutrient is modeled with the modified Sterling＇s equation. The present model describes the overall nutrient distribution and predicts various criteria for the necrosis formation inside the tumor. Present study justifies that the parameters, which controls the nutrient supply to the tumor interstitial space through the blood vessel network inside the tumor, competes with reversible nutrient consumption kinetics of the tumor cells. This study also finds the role of some of those parameters on the deformation of cellular phase of the tumor as a consequence of interstitial fluid flow.

关键词： Tumor vasculature isolated tumor biphasic mixture theory effectivenessfactor necrotic core.

Performance study and kinetic modeling of hybrid bioreactor for treatment of bi-substrate mixture of phenol-m-cresol in wastewater:Process optimization with response surface methodology

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Journal of Environmental Sciences 2013年第4期25卷 698-709页

作者： Sudipta dey Somnath Mukherjee Department of Biotechnology Heritage Institute of TechnologyAnandapurChowbaga RoadKolkata-700107West BengalIndia Environmental Engineering Division Civil Engineering DepartmentJadavpur UniversityRaja S.C.Mallic RoadKolkata-700032West BengalIndia

Performance of a hybrid reactor comprising of trickling filter （TF） and aeration tank （AT） unit was studied for biological treatment of wastewater containing mixture of phenol and m-cresol, using mixed microbial culture. The reactor was operated with hydraulic loading rates （HLr） and phenolics loading rates （PLr） between 0.222-1.078 m3/（m2-day） and 0.900-3.456 kg/（***）, respectively. The efficiency of substrate removal varied between 71%-100% for the range of HLr and PLr studied. The fixed film unit showed better substrate removal efficiency than the aeration tank and was more resistant to substrate inhibition. The kinetic parameters related to both units of the reactor were evaluated and their variation with HLr and PLr were monitored. It revealed the presence of substrate inhibition at high PLr both in TF and AT unit. The biofilm model established the substrate concentration profile within the film by solving differential equation of substrate mass transfer using boundary problem solver tool ＇bvp4c＇ of MATLAB 7. 1 software. response surface methodology was used to design and optimize the biodegradation process using Design Expert 8 software, where phenol and m-cresol concentrations, residence time were chosen as input variables and percentage of removal was the response. The design of experiment showed that a quadratic model could be fitted best for the present experimental study. Significant interaction of the residence time with the substrate concentrations was observed. The optimized condition for operating the reactor as predicted by the model was 230 mg/L of phenol, 190 mg/L of m-cresol with residence time of 24.82 hr to achieve 99.92% substrate removal.

关键词： hybrid bioreactor bi-substrate phenol m-cresol response surface methodology biofilm model

PEgylation in anti-cancer therapy: An overview

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Asian Journal of Pharmaceutical Sciences 2016年第3期11卷 337-348页

作者： Prajna Mishra Bismita Nayak r.K.dey Centre for Applied Chemistry Central University of Jharkhand Department of Life Science National Institute of Technology

Advanced drug delivery systems using poly(ethylene glycol)(PEg) is an important development in anti-cancer therapy. PEgylation has the ability to enhance the retention time of the therapeutics like proteins, enzymes small molecular drugs, liposomes and nanoparticles by protecting them against various degrading mechanisms active inside a tissue or cell, which consequently improves their therapeutic potential. PEgylation effectively alters the pharmacokinetics(PK) of a variety of drugs and dramatically improves the pharmaceutical values;recent development of which includes fabrication of stimuli-sensitive polymers/smart polymers and polymeric micelles to cope of with the pathophysiological environment of targeted site with less toxic effects and more effectiveness. This overview discusses PEgylation involving proteins, enzymes, low molecular weight drugs, liposomes and nanoparticles that has been developed, clinically tried for anti-cancer therapy during the last decade.

关键词： PEg PEgylation Polymers Targeted drug delivery