UV Induced Processes in Biomolecules, Hydrated Clusters and Stark Deflected Beams

The nanoscale processes by which UV irradiation initiates damage in biological material have not yet been fully elucidated. This represents a barrier to innovations in radiotherapy and also limits our understanding of the molecular origins of life. Experiments on gas-phase biological building blocks can reveal detailed information via comparisons with high-level calculations, while parallel studies of biomolecular clusters offer a route to assess the effects of condensed biological environments. This thesis investigates the stabilities and relaxation pathways of isolated and clustered nucleobases in neutral electronic excited states and ionic states. Furthermore, it presents a new laser thermal desorption facility and reports advances in applying Stark deflection to narrow the range of molecular and cluster configurations in continuous supersonic beams. The key analytical tool in this thesis is UV multi-photon ionization time-of-flight mass spectrometry (MPI-TOF). High-resolution measurements on the RNA base uracil and its fully-deuterated analogue provide new evidence supporting a ring-opening process in a neutral electronic excited state. Comparing experiments on uracil in supersonic beams and from the laser thermal desorption source show that the MPI channel that marks this ring-opening process is not sensitive to the vaporization method and aid comparisons with time-resolved experiments at Heriot Watt University. Exploiting the capabilities of reflectron mass spectrometry to study the metastable dissociation of excited ions and cluster ions is a major theme in this thesis. Photon energy thresholds for metastable dissociation from multi-photon ionized uracil and thymine are reported for the first time. We argue that these thresholds can provide a new route to deduce the adiabatic energies of neutral electronic excited states. Further metastable dissociation experiments and detailed comparisons with ab initio calculations provide the most detailed study of the stable configurations of thymine-water cluster ions to date. The variety of different structural configurations of biomolecules and clusters in neutral target beams presents a major challenge in the experimental study of radiation-induced processes. Stark deflection in electric field gradients offers a powerful method to address this challenge and has previously been used to select specific polar species from mixed pulsed supersonic beams. However, the low pulsing frequencies of such beams are unsuitable to study many collision-induced processes. This thesis reports on the development of a system at the Open University that uses Stark deflection to manipulate continuous beams with the ultimate aim of probing electron attachment processes in selected clusters. Controlled deflection of nitromethane is demonstrated in a helium beam with 94% recovery of the deflected molecules. The manipulation of nucleobases using Stark deflection is achieved for the first time, with continuous argon and krypton expansions providing the necessary rotational cooling. Isolated and clustered nucleobases show very different responses to the deflecting fields, providing a method to gain insights into the origins of specific fragment ions in MPI and electron impact ionization experiments

Research Publication Pattern of Journal of Indian Library Association (JILA): A Bibliometric Analysis during 2015-2019

The present paper aims to investigate the publishing pattern of The Journal of Indian Library Association (JILA) published during 2015-2019. During this period, a total of 107 research articles has been published by various contributors across the country. The study explores the bibliometric aspects like distribution of articles, year-wise growth of publications, authorship pattern of publication their degree of collaboration and an average rate of publication per author. The maximum growth rate was measured in the year 2019 with 21.73%, and individual authors published 47.67% of scholarly articles. The findings of the study demonstrate the strength of the Journal, which will be helpful for further development

Comparative Pressure Drop in Laminar and Turbulent Flows in Circular Pipe with and without Baffles using FEV

The study of Turbulent flow characteristics in complex geometries receives considerable attention due to its Importance in many engineering applications and has been the subject of interest for researchers. Some of these include the energy conversion systems found in same design of heat exchangers, nuclear reactor, solar collectors & cooling of industrial machines and electronic components. Flow in channels with baffle plates occurs in many industrial applications such as heat exchangers, filtration, chemical reactors, and desalination. These baffles cause turbulence which leads to increases friction within the pipe or duct and leads significant pressure drop. This work is concern with the comparative flow and pressure distribution analysis of a smooth and segmented Baffles pipe. In which pressure drop during the flow is examined and with the help of hydrodynamic characteristics performance is predicted with the help of Finite element volume tool ANSYS- Fluent, where simulation is been done. The goal is to carry out evaluating pressure drop across the pipe using different turbulent model and at simulation is done for wide range of Reynolds number in both laminar and turbulent flow regimes. The FEV results are validated with well published results in literature and furthermore with experimentation. The FEV and experimental results show good agreement

CYBER PORNOGRAPHY ADDICTION AMONGST MEDICAL STUDENTS OF WESTERN RURAL MAHARASHTRA

Introduction: Cyberpornography is an act of using cyberspace to create, display, distribute, impart or publish pornography or obscene materials, especially materials depicting children engaged in sexual acts with adults. Cyberpornography on one hand, has opened up the new terrain of \u27safe sex\u27, and a positive space for sexual non-conformists. At the same time, it has negatively impacted many offline relations, and a new space for sexual predation and exploitation. Objective: To find out the prevalence, type and form of risk towards cyber pornography addiction amongst the students. Methods & Materials: A prospective cross sectional study was conducted after obtaining an ethical approval from the institute and an informed consent from volunteers fulfilling the eligibility criteria. The Internet sex screening test (ISST) questionnaire with score sheet was used and was collected by complete anonymity and confidentiality. 300 medical students were considered for the study and data collected was analysed by Microsoft-office excel. Results: 57.15% of the volunteer are in low-risk group whereas 30% are vulnerable and 12.85% are in highest-risk group. For boys, 65% are vulnerable whereas 21% in low-risk and the remaining 14% are in highest-risk group. For girls, 73% are in a low-risk, 19% are vulnerable and 8% are in highest-risk group. Conclusion: It is concluded that the majority of boys come under vulnerable category whereas the girls comes in low-risk group showing male preponderance towards addiction. The study reveals that, questions coming under the subgroup of online sexual behaviour-isolated have been answered the maximum number of times, by both the sexes. Whereas, the questions coming under the subgroup of online sexual spending has been answered the least by both the sexes. KEYWORDS: Cyberpornography; Addiction; Sexual behaviour; ISST Questionnaire