The effect of solvent temperature on the lyoluminescence yield in saccharides has been studied employing photon counting technique over a solvent temperature range 10-90°C. It is observed that yield per mg decreases with temperature in all the five saccharides. A qualitative explanation of the findings, on the basis of molecular structure, formation of collisional pairs and molecular aggregation, has been offered. © 1998 Elsevier Science B.V. All rights reserved.

G S MAHAPATRA

C HALDAR

P BANERJI

D BANERJEE

R BHATTACHARYA

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Study of temperature dependence in saccharide-based lyoluminescence

Journal of Luminescence

The effect of solute mass on lyoluminescence (LL) decay times of γ-irradiated saccharides has been studied employing photon counting technique over a solute mass range 1-20 mg at room temperature. It is observed that all the decay times increase linearly with solute mass. The decay time of the longest component in each of the saccharides studied increases markedly as the solute mass is increased. This finding suggests that the structure of the solute molecule persists longer as larger solute mass is dissolved.

Radiation Effects and Defects in Solids

Mass dependence of lyoluminescent decay in saccharides

The temperature dependence of lyoluminescent decay times in saccharides has been studied employing photon counting technique over a solvent (water) temperature range 10-90°C. It is observed that the decay times of all the three components decrease with increase in temperature. An attempt has been made to explain the results on the basis of free radical recombination, rate of dissolution and molecular structure.

Temperature dependence of lyoluminescent decay in saccharides

The lyoluminescence yield in γ-irradiated glucose, lactose and mannose has been studied, to look for the effect of mass at different doses and solvent pHs on the yield. It is seen that the light yield per mg (Y/m) is different for different solute masses and its nature of variation with mass is independent of irradiation dose and solvent pH. Further, Y/m is independent of pH in the range 4-9. No significant dependence of Y/m on solute mass is found above a certain mass, the level-off point. Estimation of a dose, when it is necessary to be carried out by using a solute mass below the level-off point, therefore, has to be made with reference to the particular Y/m vs dose curve drawn for that solute mass.The lyoluminescence yield in γ-irradiated glucose, lactose and mannose has been studied, to look for the effect of mass at different doses and solvent pHs on the yield. It is seen that the light yield per mg (Y/m) is different for different solute masses and its nature of variation with mass is independent of irradiation dose and solvent pH. Further, Y/m is independent of pH in the range 4-9. No significant dependence of Y/m on solute mass is found above a certain mass, the level-off point. Estimation of a dose, when it is necessary to be carried out by using a solute mass below the level-off point, therefore, has to be made with reference to the particular Y/m vs dose curve drawn for the solute mass.

Applied Radiation and Isotopes

Effect of solute mass and solvent pH on lyoluminescent saccharides used for gamma-ray dosimetry

The lyoluminescence decay times of γ-irradiated saccharides (mannose, glucose, lactose and trehalose dihydrate) have been measured by employing photon counting technique. It is observed that all the saccharides show three decay components for all the doses studied. It is also seen that the decay times and their corresponding intensities do not depend on the irradiation dose. Attempts have been made to correlate the results with the findings from ESR measurements.

The decay times of lyoluminescent saccharides

In view of the contradictory reports of various investigators, the mass effect in radiation-induced lyoluminescence has been reinvestigated using a photon-counting technique. It is seen that the mass effect is present in both the disaccharide materials investigated, viz. sucrose and trehalose dihydrate. A likely cause of the effect may lie in the free radicals getting quenched in solution due to molecular aggregation at larger masses when the recombined nonradical product (due to radical-radical interaction) increases. This results in a decrease in LL yield with an increase of solute mass. © 1994.

Mass effect in radiation-induced lyoluminescence of sugars

The decay times of lyoluminescent NaCl, KCl and KBr have been measured using the photon counting technique. It is seen that there are two decay components for all these halides. The conventional light emission mechanism does not seem to explain more than one decay. A possible explanation of the origin of the two decay components is presented. © 1994.

Journal	Data powered by TypesetJournal of Luminescence
Publisher	Data powered by TypesetElsevier
ISSN	0022-2313