Jai Mittal
Bhabha Atomic Research Centre, Chemistry Group, Department Member
- Research Professor in Photo and Radiation Chemistryedit
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ABSTRACT Crystalline nanoparticles of anatase phase nitrogen-doped TiO2 (N-TiO2), boron and nitrogen codoped TiO2 (B-N-TiO2), and undoped TiO2 (TiO2) were synthesized by a facile xerogel method followed by reduction in a glycol medium to... more
ABSTRACT Crystalline nanoparticles of anatase phase nitrogen-doped TiO2 (N-TiO2), boron and nitrogen codoped TiO2 (B-N-TiO2), and undoped TiO2 (TiO2) were synthesized by a facile xerogel method followed by reduction in a glycol medium to forcibly create Ti3+ ions (self-doping) in them (R-N-TiO2, R-B-N-TiO2, and R-TiO2, where R stands for reduced) and studied their photocatalytic activity for hydrogen generation from water. A clear red shift of the absorption edge and stronger absorption in the visible region was observed for both reduced and unreduced N-TiO2 and B-N-TiO2 compared to the other samples. The presence of bonded nitrogen in the N-doped samples was evidenced from their N1s X-ray photoelectron spectra. Photocatalytic activity for hydrogen generation using sunlight-type radiation showed enhanced activity for the reduced and doped samples compared to pristine TiO2. The enhanced photocatalytic activity of the R-N-TiO2 for hydrogen generation is attributed to the enhanced light absorption resulting from the narrowing of the band gap caused by the contribution of anion levels near the conduction band and 2p levels of N near the valence band of TiO2. A significant enhancement of photocatalytic activity was observed when Pd metal was present as a cocatalyst due to the efficient separation of photogenerated charge carriers in these nanoparticles.
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Research Interests: Chemistry, Photochemistry, Electron Transfer, Radiolysis, Radical, and 3 moreRedox, Neutral Red, and Adduct
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Many isotopes (stable or radio-active) are widely used for medical therapy, diagnostics, agriculture, food processing and nuclear power generation, to name a few. Isotope separation using lasers constitutes one of the major challenges in... more
Many isotopes (stable or radio-active) are widely used for medical therapy, diagnostics, agriculture, food processing and nuclear power generation, to name a few. Isotope separation using lasers constitutes one of the major challenges in research in physics and chemistry. This article traces some of the important initiatives taken at BARC, in India, towards these goals.
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Platinum nanoparticles have been prepared by radiolytic and chemical methods in the presence of stabilizer gelatin and SiO2 nanoparticles. The formation of Pt nanoparticles was confirmed using UV–vis absorption spectroscopy and... more
Platinum nanoparticles have been prepared by radiolytic and chemical methods in the presence of stabilizer gelatin and SiO2 nanoparticles. The formation of Pt nanoparticles was confirmed using UV–vis absorption spectroscopy and transmission electron microscopy (TEM). The prepared particles were coated on the inner walls of the tubular pyrex reactor and tested for their catalytic activity for oxidation of CO. It
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... Ninnal Singh Sandbar, Mrs. Madhu P. Singh, and Dr. Mrs. Rupa Bakhshi who worked in the scheme from time to time. We are also grateful to all Agricultural Sub Inspectors working in the scheme for collection of data at farmers fields. ...
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... REFERENCES Arnold, PC Mohsenin, NN (1971). Recommended techniques for axial compression test on intact agricultural products of convex shape. Trans. of the American Society of Agricultural Engineers. 14(1), 7884. 68 JP Mittal, BO Oke,... more
... REFERENCES Arnold, PC Mohsenin, NN (1971). Recommended techniques for axial compression test on intact agricultural products of convex shape. Trans. of the American Society of Agricultural Engineers. 14(1), 7884. 68 JP Mittal, BO Oke, RN Kaul Mohsenin, NN Mittal, JP ...
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... 0 ze, o ..= 0 e, k 42 BO Oke, RN Kaul, JP Mittal () rh ql eh 0 Z 4 .=. ,r9 ot E ca) .= EL Properties of sorghum stalk 43 0 ..a 0 "6 ak 44 BO Oke, RN Kaul, JP Mittal ga 0 raO ,,,a .,.a 0 e, re:m 'N a "..a , . : ; = z... more
... 0 ze, o ..= 0 e, k 42 BO Oke, RN Kaul, JP Mittal () rh ql eh 0 Z 4 .=. ,r9 ot E ca) .= EL Properties of sorghum stalk 43 0 ..a 0 "6 ak 44 BO Oke, RN Kaul, JP Mittal ga 0 raO ,,,a .,.a 0 e, re:m 'N a "..a , . : ; = z " 0 r Properties of ... REFERENCES Arnold, PC Mohsenin, NN (1971). ...
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ABSTRACTThe importance of maintaining the purity of rheological terms and using them only when measurements and definitions are in accordance with the accepted rheological definitions is pointed out. It is shown that if rheological terms... more
ABSTRACTThe importance of maintaining the purity of rheological terms and using them only when measurements and definitions are in accordance with the accepted rheological definitions is pointed out. It is shown that if rheological terms and methods of measurements and analyses are used correctly, they can be employed in food texture studies even though conditions upon which the theory is based are not fully met. It is proposed that the term “modulus of elasticity” be replaced by the term “modulus of deformabtiity” which considers both recoverable and unrecoverable deformations that often take place when a food sample is subjected to even very small strains. It is also submitted that mechanical properties reflecting the behavior of the material under small strains do not necessarily correlate significantly with mechanical properties which reflect the yielding and fracturing or failure of the material. Published data are examined to test the validity of this hypothesis. In general, c...
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ABSTRACTA study on water absorption characteristics of the selected cereal grains was conducted. It was found that well dried maize, sorghum and millet grains take about 96, 48 and 24 h, respectively, to reach their water absorption... more
ABSTRACTA study on water absorption characteristics of the selected cereal grains was conducted. It was found that well dried maize, sorghum and millet grains take about 96, 48 and 24 h, respectively, to reach their water absorption capacities (water absorption saturations). Millet had the highest rate of water absorption as well as the total water absorbed. The rate of water absorption in sorghum was higher than in maize but maize grains imbibed more water than sorghum.Rupture stress of the grains and its variation with moisture content was also investigated. The rupture stress of the grains was seen to decrease with increase in moisture content except for maize which showed a rapid rise only at the onset of the increase in moisture content.
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The effect of pretreatment with buthionine sulphoximine (BSO) on the radiosensitivity of mouse bone marrow cells was studied using the in vivo micronucleus test. Varying concentrations of BSO were injected into mice by intraperitoneal... more
The effect of pretreatment with buthionine sulphoximine (BSO) on the radiosensitivity of mouse bone marrow cells was studied using the in vivo micronucleus test. Varying concentrations of BSO were injected into mice by intraperitoneal injection 2 h before irradiation, and the frequency of micronuclei in polychromatic erythrocytes (MnPCEs) of bone marrow were scored. Treatment with BSO resulted in a significant reduction (41% at 20 mg/kg body weight) in the frequency of micronuclei induced by 1 Gy gamma-rays. Reduction was observed in cells sampled at 24, 30 and 48 h postirradiation with no apparent effect on the ratio of poly- to normo-chromatic erythrocytes in BSO-treated versus control groups. Glutathione levels in the bone marrow of BSO-treated animals 2 h after a single injection were found to be unaltered. The protective effect of BSO was not observed if it was given either immediately or 2 h after irradiation. Based on these and earlier findings it seemed as if BSO molecules may be involved in physicochemical reactions with reactive species generated in the system by irradiation. BSO showed relatively high reaction rate constants with hydroxyl radical (.OH, 2.5 x 10(9) dm3 mol-1s1, calculated on the basis of competition kinetics) and with singlet oxygen (1O2, 4.3 x 10(7) dm3 mol-1s-1 but a lower rate constant with hydrated electrons (< or = 5.0 x 10(6) dm3 mol-1s1). Based on half-life estimates, transients formed and potential for damage to biomolecules, .OH and 1O2 seemed to be the possible species responsible. In vitro studies reveal that BSO has significant abilities to protect DNA against single-strand breaks and lipid peroxidation induced by 1O2 in microsomal membranes. This supports our hypothesis that BSO may be involved in scavenging the reactive species generated and that besides .OH, 1O2 may also be a major player in radiation damage.
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Two frontier production functions were applied to different categories of wheat growing farmers in Punjab. The technical efficiency for each category of farmer was determined. Actual use of various forms of energies in wheat production... more
Two frontier production functions were applied to different categories of wheat growing farmers in Punjab. The technical efficiency for each category of farmer was determined. Actual use of various forms of energies in wheat production were compared with the ...
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The state of Punjab (India) is divided into six agro-climatic zones, viz, sub-mountainous undulating zone, undulating zone, undulating plain zone, central plain zone, western zone and flood plain zone. Because of the associated vast... more
The state of Punjab (India) is divided into six agro-climatic zones, viz, sub-mountainous undulating zone, undulating zone, undulating plain zone, central plain zone, western zone and flood plain zone. Because of the associated vast changes in agro-climatic conditions, the distribution of energy consumption for crop production has not been uniform. For this study, the state was divided into four farming
Research Interests: Engineering, Environmental Science, Economics, Irrigation, Agriculture, and 13 moreEnergy Consumption, Crop Production, Fertilizer, Energy Use, Applied Energy, Energy efficient, Intensive farming, FARMING SYSTEM, Grain Yield, Energy Source, Recommended Dose, Energy Requirement, and Climatic condition
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Laser flash photolysis of the nonionic surfactant Triton X‐165 was carried out at 248 nm in methanolic and aqueous solutions at different pHs. Cation radical, triplet, phenoxy radical and solvated electron were observed as the transient... more
Laser flash photolysis of the nonionic surfactant Triton X‐165 was carried out at 248 nm in methanolic and aqueous solutions at different pHs. Cation radical, triplet, phenoxy radical and solvated electron were observed as the transient absorbing species. Various characteristics of these transient species and their decay constants are reported. Photoionization was found to be a major process and it was monophotonic. The results obtained are compared with the photolysis of a small molecule p‐methoxytoluene (PMT). Fluorescence and phosphorescence properties of the surfactants Triton X‐100, Triton X‐165 and PMT are also studied. A suitable reaction scheme is proposed to account for the observed results.
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Photophysical properties of the excited singlet and triplet states of pentaphenylfulleren-2-ol (C60 (C6H5) 5OH, PPF) and penta-4-fluorophenylfulleren-2-ol [C60 (C6H4F) 5OH, PFPF], two derivatives of buckminsterfullerene, C60, have been... more
Photophysical properties of the excited singlet and triplet states of pentaphenylfulleren-2-ol (C60 (C6H5) 5OH, PPF) and penta-4-fluorophenylfulleren-2-ol [C60 (C6H4F) 5OH, PFPF], two derivatives of buckminsterfullerene, C60, have been investigated in benzene and ...
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In a discharge-flow experiment, chemiluminescent reactions of oxygen atoms (O( 3 P)) with organic nitriles (RCN) are studied. For unsaturated nitriles RCN (R: CH 2 =CH; CH 2 =C(CH 3 ); CH 2 =CH(CH 2 )) the observed emission is attributed... more
In a discharge-flow experiment, chemiluminescent reactions of oxygen atoms (O( 3 P)) with organic nitriles (RCN) are studied. For unsaturated nitriles RCN (R: CH 2 =CH; CH 2 =C(CH 3 ); CH 2 =CH(CH 2 )) the observed emission is attributed to CN * (B→X) and NO * (γ:A→X and β: ...
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Radiation chemical reactions of •OH, O•-, and SO4•- with benzaldehyde, acetophenone, and benzophenone have been studied using both pulse and steady-state radiolysis techniques. The observed rates for the •OH addition (k = (2.6−8.8) × 109... more
Radiation chemical reactions of •OH, O•-, and SO4•- with benzaldehyde, acetophenone, and benzophenone have been studied using both pulse and steady-state radiolysis techniques. The observed rates for the •OH addition (k = (2.6−8.8) × 109 M-1 s-1) are higher than those found for the SO4•- reaction (k = (0.7−4.0) × 109 M-1 s-1). The rate for the reaction of O•- with benzaldehyde is higher than that found for •OH, while a reverse trend is observed in the case of the two ketones. Optical absorption spectra of the intermediate transients formed in the reactions of •OH and SO4•- with all three compounds are similar with a peak around 370−380 nm. The absorption spectra from the O•- reaction have shown a major peak at 310 nm and are somewhat different from those obtained in the reaction of •OH. The yields of the phenolic products formed in the reaction of •OH with benzaldehyde and acetophenone in the presence of 0.1 mM ferricyanide corresponded to only 30% and 50% •OH yields, respectively. Benzoic acid is a major...
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Research Interests: Biochemistry, Chemistry, Carbon, Membrane Proteins, Medicine, and 15 moreAntioxidants, Fullerenes, Female, Animals, Glutathione, Enzyme, Lipid peroxidation, Ascorbic Acid, Oxidative Damage, Oxidative phosphorylation, Cyclodextrins, Oxidants, Histidine, Biochemistry and cell biology, and In Vitro Techniques
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ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full... more
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
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The radical cation of 2-(phenylthio)ethanol (PTE) + , generated on reaction of specific one-electron oxidants Cl 2 - , Tl 2 + , SO 4 - , CCl 3 OO, Br 2 - , by pulse radiolysis in aqueous solutions of PTE exhibits absorption bands at 315... more
The radical cation of 2-(phenylthio)ethanol (PTE) + , generated on reaction of specific one-electron oxidants Cl 2 - , Tl 2 + , SO 4 - , CCl 3 OO, Br 2 - , by pulse radiolysis in aqueous solutions of PTE exhibits absorption bands at 315 and 530 nm. Pulse radiolysis of PTE in 1,2-dichloroethane also produced a similar transient absorption spectrum. The hydroxyl radicals are observed to react with a bimolecular rate constant of 7.5×10 9 d mol -1 s -1 and form absorption bands at 300, 365 and 530 nm. While the 530 nm band decayed by first order kinetics with k=2.1×10 4 s -1 , other bands showed mixed kinetics. O - reacts exclusively by H atom abstraction forming a transient absorption band in 290-330 nm region, H reacts both by H abstraction and H-adduct formation. Based on these studies, OH radicals are inferred to react by electron transfer, H abstraction and OH-adduct formation. The radical cation reacts with electron donors, I - , N 3 - , with a high rate constant value. In neutral solutions, e aq - reacts with a bimolecular rate constant of 7.1×10 8 d mol -1 s -1 and the transient absorption band at 360 nm (Iμ=1.4×10 3 d mol -1 cm -1 ) is assigned to H-adduct formed on protonation of radical anion (pK a =7.9). In basic solutions, the radical anion has very small absorption at 360 nm (Iμ=0.6×10 3 d mol -1 cm -1 ). The radical anion formed on reaction of e aq - with PTE at pH 12 is able to transfer an electron to MV 2+ whereas at neutral pH, electron transfer is not possible. The reduction potential for the PTE/PTE - couple is determined to be -1.23V.
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... H. Mohan 1 , M. Mudaliar 2 , BSM Rao 2 and JP Mittal 1. 1 Chemistry Division, Bhabha Atomic Research Centre, Trombay, Bombay 400 085, India. ... Guha SN, Moorthy PN, Kishore K., Naik DB and Rao KN (1987) One electron reduction in... more
... H. Mohan 1 , M. Mudaliar 2 , BSM Rao 2 and JP Mittal 1. 1 Chemistry Division, Bhabha Atomic Research Centre, Trombay, Bombay 400 085, India. ... Guha SN, Moorthy PN, Kishore K., Naik DB and Rao KN (1987) One electron reduction in thionine studied by pulse radiolysis. ...
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The reaction of OH radicals with a number of substituted halobenzenes (C,H,-,X,Y, ... = 2.6 x 1 O3 dm3 mo1-l cm-l. For ... The y-radiation-induced chemical reactions of aqueous sol-utions of benzene and its substituted derivatives are of... more
The reaction of OH radicals with a number of substituted halobenzenes (C,H,-,X,Y, ... = 2.6 x 1 O3 dm3 mo1-l cm-l. For ... The y-radiation-induced chemical reactions of aqueous sol-utions of benzene and its substituted derivatives are of current interest.'., The reaction of ...
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The dynamics of the gas-phase hydrogen atom exchange reaction H + DCl --> HCl + D were studied using the pulsed laser photolysis/laser induced fluorescence... more
The dynamics of the gas-phase hydrogen atom exchange reaction H + DCl --> HCl + D were studied using the pulsed laser photolysis/laser induced fluorescence "pump-and-probe" method. Laser photolysis of H2S at 222 nm was used to generate nonequilibrium distributions of translationally excited hydrogen atoms at high dilution in a flowing moderator gas (Ar)/reagent (DCl) mixture. H and D atoms were detected with sub-Doppler resolution via Lyman-alpha laser induced fluorescence spectroscopy, which allowed the measurement of the line shapes of the moderated H atom Doppler profiles as well as the concentration of the D atoms produced in the H + DCl --> HCl + D reaction. From the measured H atom Doppler profiles, the time evolution of the initially generated nascent nonequilibrium H atom speed distribution toward its room-temperature thermal equilibrium form was determined. In this way, the excitation function and the reaction threshold (E0 = 0.65 +/- 0.13 eV) for the H + DCl --> HCl + D reaction could be determined from the measured nonequilibrium D atom formation rates and single collision absolute reaction cross-section values of 0.12 +/- 0.04 A2 and 0.45 +/- 0.11 A2 measured at reagent collision energies of 1.0 and 1.4 eV, respectively.