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Photoisomerization Dynamics of 2-[(E)-(4-fluorophenyl)diazenyl]-1 H -imidazole: A Theoretical and Experimental Insight
This study investigates the photoresponsive behavior of substituted azobenzenes with a specific focus on their nonlinear optical response. This study suggests that azoimidazole substitution is a better alternative to azobenzene derivatives for nonlinear optical responses. The synthesis, characterization, photophysical property and isomerization pathway of 2-[(E)-(4-fluorophenyl)diazenyl]-1H-imidazole (E-2g) are presented as an optical limiter through a comprehensive blend of experimental and theoretical approaches. Notably, E-2g exhibited a lower energy barrier than reported azobenzenes. The trans-to-cis photostationary state was reached in 75 min, while the cis-to-trans state was achieved in 60 min at 354 nm. The study further explores the photoisomerization pathway of E-2g, highlighting its nonlinear absorption, which has a nonlinear absorption coefficient (?eff) of 8.8 10-11 m/W at 20 ?J, as determined by Z-scan measurements. The results suggest that E-2g exhibits significant nonlinear absorption characteristics, which helps in applications requiring protection from intense light sources. 2024 World Scientific Publishing Company. -
Photoluminescence studies of non-toxic monoclinic yttrium oxide quantum dots synthesized at low temperature for live cell imaging applications
Synthesis of monoclinic Y2O3 remains a challenging task due to complex formation conditions such as high pressure or high temperature environments. Monoclinic yttria exhibits better photoluminescence characteristics compared to the cubic phase and hence can be a better host for nanophosphors. Reports are available predicting the stability of monoclinic phase at low temperature in extremely fine particles. But experimental preparation of this phase at low temperature is not yet reported. Here we report the first-time preparation of monoclinic Y2O3 at 90 C using simple laboratory hot air oven. The synthesized nanoparticles exhibit intense PL emission in the blue region and hence can find applications in display industry. The band structure calculations were carried out using density functional theory and the excitonic Bohr radius was estimated using the electron as well as hole effective masses determined from band structure. The cytotoxicity studies reveal non-toxic nature the particles. The fluorescence imaging experiments show that the material is capable of emitting blue fluorescence in L6 skeletal cell lines and it ensures the applicability of this material in the biomedical field. 2022 Elsevier Ltd and Techna Group S.r.l. -
Photometric identification of objects from galaxy evolution explorer survey and sloan digital sky survey
We have used Galaxy Evolution Explorer (GALEX) and Sloan Digital Sky Survey (SDSS) observations to extract seven band photometric magnitudes for over 80 000 objects in the vicinity of the North Galactic Pole. Although these had been identified as stars by the SDSS pipeline, we found through fitting with model spectral energy distributions that most were, in fact, of extragalactic origin. Only about 9 per cent of these objects turned out to be mainsequence stars and about 11 per cent were white dwarfs and red giants collectively, while galaxies and quasars contributed to the remaining 80 per cent of the data. We have classified these objects into different spectral types (for the stars) and into different galactic types (for the galaxies). As part of our fitting procedure, we derive the distance and extinction to each object and the photometric redshift towards galaxies and quasars. This method easily allows for the addition of any number of observations to cover a more diverse range of wavelengths, as well as the addition of any number of model templates. The primary objective of this work is to eventually derive a three-dimensional extinction map of the Milky Way Galaxy. 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. -
Photophysical and antitubercular studies on newly synthesised structurally architectured sulphonamide
This study presents the synthesis and characterisation of four mono-azo sulphonamide derivatives through diazo-coupling electrophilic substitution reactions. The structural analysis of the synthesised molecules was conducted utilising FT-IR, 1H-NMR and HR-MS techniques. Absorption and fluorescence maxima of the synthesised molecules were determined across solvents of varying polarity to explore Solvatochromic behaviour. Density functional theory was employed to elucidate electronic and optical properties, including the computation of HOMOLUMO energies using Gaussian 09W software, with comparisons to experimental data. Molecular electrostatic potential 3D plots identified electrophilic and nucleophilic sites. Solvent interactions were evaluated using KamletAbboud Taft and Catalan parameters. Further, global chemical reactivity descriptors were estimated to ascertain chemical reactivity of the molecules. Additionally, the effectiveness of the colourant anti-tubercular activity was evaluated using in vitro and molecular docking techniques. The biological activity results reveal that methyl-pyridone and barbituric acid coupled with sulphamethizole (SMP and SMB) displayed excellent anti-tubercular activity compared with the standard Gentamycin. 2024 Informa UK Limited, trading as Taylor & Francis Group. -
Photophysical and Electrochemical Studies of Anchored Chromium (III) Complex on Reduced Graphene Oxide via Diazonium Chemistry
Covalently anchored chromium complex on reduced graphene oxide (rGO-Cr) is successfully synthesised through trimethoxy silyl propanamine (TMSPA) and phenyl azo salicylaldehyde (PAS) coupling. The rGO-Cr is characterised by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electron dispersive analysis of X-rays (EDAX), Raman spectroscopy, scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). Absorption and emission properties of rGO-TMSPA-PAS are studied by excitation dependent photoluminescence emissions at room temperature. Electrochemical sensing activity of rGO-Cr is monitored for paracetamol using modified glassy carbon electrode. Cyclic voltammetry measurements indicated that rGO-Cr substantially enhance the eletrochemical response of paracetamol. The experimental factors are investigated and optimized. 2019 John Wiley & Sons, Ltd. -
Photophysical and In Vitro-In Silico Studies on Newly Synthesized Ethyl 3-((3-Methyl-1-phenyl-1H-pyrazol-5-yl)oxy)-2-methyleneheptanoate
Abstract: In the present work, the aryl-substituted pyrazolone derivative ethyl 3-((3-methyl-1-phenyl-1H-pyrazol-5-yl)oxy)-2-methyleneheptanoate (ETT) has been synthesized by the reaction of Baylis-Hillman acetate with pyrazolones and screened for their in vitro antifungal, antibacterial, and antioxidant properties. The molecule shows good in vitro antifungal and antibacterial activities due to the presence of pentane, which enhances the absorption rate by its increased lipid solubility and improves the pharmacological activity. It is also evident from the results obtained from structure-activity relationship (SAR) studies. In silico studies were conducted on the synthesized molecule, examining its interactions with DNA Gyrase, Lanosterol14 alpha demethylase, and KEAP1-NRF2 proteins. The results revealed strong binding interactions at specific sites. Further, the photophysical properties of synthesized compounds were theoretically estimated using the ab-intio technique. The ground state optimization, dipole moment, and HOMOLUMO energy levels are calculated using the DFT-B3LYP-6-31G(d) basis set. Using the theoretically estimated HOMOLUMO value, global chemical reactivity descriptor parameters are estimated, and the result shows the synthesised molecule has a highly electronegative and electrophilic index. NBO analysis proved the presence of intermolecular ON.H hydrogen bonds caused by the interaction of the lone pair of oxygen with the anti-bonding orbital. The results suggest that pentane-substituted pyrazolone derivatives show good photophysical and biological applications. Pleiades Publishing, Ltd. 2024. -
Photophysical study of 6-amino-3-methyl-4-(4-nitrophenyl)-1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile and estimation of ground-state and singlet excited-state dipole moments by solvatochromic approaches
An investigation of absorption and fluorescence behaviour of 6-amino-3-methyl-4-(4-nitrophenyl)-1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile (NDPPC) at room temperature was carried out using a series of twelve organic solvents with different polarities. Ground and excited state dipole moments were determined experimentally by using LippertMataga polarity function, Bakhshiev solvent polarity parameter, Kawski-Chamma-Viallet solvent polarity parameter, Reichardt's microscopic solvent polarity parameter, Kamlet-Abboud-Taft multiple linear regression and Catalan dipolar polarizibility approach. Due to considerable ?- electron density redistribution, the value of excited state dipole moment was found to be greater than that of the ground state. The ground state dipole moment value was determined by quantum chemical method which was used to estimate excited state dipole moment using solvatochromic correlations. Both non-specific solute-solvent interactions and hydrogen bonding interactions were investigated by using Kamlet-Abboud-Taft and Catalan method. TD-DFT (B3LYP/6-311G (d,p)) was used for the determination of HOMO-LUMO energies. 2016 Elsevier B.V. -
Photoresponse and electrochemical behaviour of azobenzene anchored graphene oxide for energy storage application
Solar energy is considered to be a renewable source of energy that is intrinsically more sustainable than fossil fuels. Developing photoactive hybrid materials to store solar energy has recently received much attention. Herein, a photoactive molecule-graphene oxide hybrid was synthesized and characterized systematically. The solar energy storage performances of the hybrids were studied using various photophysical studies. The energy density and power density of the hybrid materials were 47 WhKg?1 and 156.6 WKg-1 respectively which showed 3 fold higher than the pristine compound. The photoelectrochemical behaviour of the hybrid were also studied using Cyclic voltammetry and Electrochemical impedance spectroscopy (EIS). Results showed the electrochemical performances can be varied due to their changing conformations from trans-to-cis isomerization. This work enables the research community in developing a promising material for solar thermal fuels as well as in energy storage devices. 2023 Elsevier B.V. -
Photovoltaic Power Plant Performance Improvement with Electric Vehicle Integration: Integrated Control Strategies
The combination of Photovoltaic (PV) systems and Electric Vehicles (EVs) holds enormous promise in an era characterized by growing environmental consciousness and sustainable energy solutions. PV technology is a clean, sustainable energy source that produces electricity by utilizing solar energy. Concurrently, EVs electrification of transportation is a critical step in the direction of lower greenhouse gas emissions and more energy efficiency. Through the use of advanced control systems, this research aims to push the boundaries of current practice in the area of PV and EV integration. Specifically, it focuses on the Icos? controller and dq controller to regulate voltage, minimize Total Harmonic Distortion (THD), and facilitate bidirectional power flow. A thorough Simulink model is created, simulating a complicated PV-EV-grid system, in order to evaluate the effectiveness of different control mechanisms. This model accommodates the unique characteristics of Plug-in Hybrid Electric Vehicles (PHEVs) and enables a detailed assessment of the percentages of voltage and current THD under different operating situations. It can handle both linear and non-linear loads. Most importantly, the studys findings showthattheTHDvaluesmeetthestrictrequirementsoutlinedinIEEE519, highlighting the efficiency of the integrated control approaches. The research not only contributes to the advancement of PV and EV technologies but also paves the way for grid-compatible, high-quality power distribution. This endeavor facilitates sustainable energy integration while simultaneously reducing the environmental footprint, making substantial strides toward a greener and more energy-efficient future. 2024 Seventh Sense Research Group -
Photovoltaic Structures Using Thermally Evaporated SnS and CDS Thin Films
Thin Solid Films, Vol-545, pp. 543-547. ISSN-0040-6090 -
Photovoltaic structures using thermally evaporated SnS and CdS thin films
Polycrystalline tin sulfide thin films were prepared by thermal evaporation technique.The films grown at substrate temperature of 300 C had an orthorhombic crystal structure with strong preferred orientation along (111) plane.Electrical resistivity of the deposited films was about 32.5 ? cm with a direct optical band gap of 1.33 eV.Carrier concentration and mobility of charge carriers estimated from the Hall measurement were found to be 6.24 1015 cm- 3 and 30.7 cm2V- 1 s- 1 respectively.Heterojunction solar cells were fabricated in superstrate configuration using thermally evaporated SnS as an absorber layer and CdS, In:CdS as window layer.The resistivity of pure CdS thin film of a thickness of 320 nm was about 1-2 ? cm and was reduced to 40 10- 3 ? cm upon indium doping.The fabricated solar cells were characterized using solar simulator.The solar cells with indium doped CdS window layer showed improved performance as compared to pure CdS window layer.The best device had a conversion efficiency of 0.4% and a fill factor of 33.5%. 2013 Elsevier B.V.All rights reserved. -
Phyllanthus Emblica Extract Protects the Rat Liver Cells Against the Toxicity of Monosodium Glutamate: Experimental Evidence
Background: Monosodium glutamate (MSG), used widely in the food industry, is a threat to the public health. We investigated whether the MSG administration depletes non-enzymatic antioxidants, i.e., vitamins C and E in the liver of Wistar albino rats. We also examined the restorative effect of the ethanolic extract of Phyllanthus emblica (P. emblica). Methods: Wistar albino rats (n=42) were adapted and then randomly divided into seven groups of: 1) control, 2, 3, 4) MSG treatment, and 5, 6, 7) combined MSG and P. emblica extract treatment. All rat groups were treated daily for 120 days. They were orally administered either MSG alone or MSG plus the extract combined. The rats were then sacrificed and the liver was harvested from each group, and homogenized to examine the levels of vitamins C and E in the liver, using RP-HPLC method. Results: The vitamins C and E levels significantly declined (P<0.05) in the liver of MSG treated groups compared to those of the control rats. The combined treatment (extract + MSG) at low and moderate doses restored the vitamin C levels but it restored vitamin E only at the low dose (P<0.05). Conclusions: This study clearly demonstrated the deterioration of non-enzymatic antioxidants, i.e., vitamins C and E in the rats' liver after chronic exposure to MSG. The findings support the toxic effect and oxidative stress due to MSG exposure to the liver and the beneficial effect of the extract of P. emblica that inhibits the MSG's harmful effect on the liver. The Author(s), 2022. -
Physical Abuse in the Absence of Ubuntu
Students in Africa and worldwide should learn about Ubuntu at the school, secondary school, college, and university levels. It should be incorporated into the educational process. Tobacco-free days, alcohol-free (dry days), and drug-free days could all be ways to commemorate Ubuntu. Female smokers are at a higher risk than male smokers. Following such measures may aid in raising awareness. Legislators in Africa need to employ incentives to amend legislation to fully integrate Ubuntu into society. It is possible to prevent violence against women and children by instilling Ubuntu principles in the community and society. It is sufficient to refer to the existing Ubuntu documentation to design and validate the necessary training programme. Still, in the case of Ubuntu, more experimental research should be encouraged. Such research must be funded by both the government and the private sector. Even though Ubuntu started in Africa, it can be globalized. Nevertheless, Ubuntu has not been adopted to its full potential in the current situation. The Zulu people of South Africa is well-known for its kindness and hospitality, and it is to them that we owe the concept of Ubuntu. According to Ubuntu, we are people not because of who we are but because of how we connect with other people. This implies that relationships are essential. With over three thousand diverse African tribes, diversity management is critical, and Ubuntu can be a driving force in bringing all the diversity under one umbrella. There are cultural mechanisms in all African traditions and events that exist to unite, but this aspect of unity is within the community, and Ubuntu can be implemented to lead the same element of harmony with various communities. There are ways to integrate Ubuntu as a cultural event into the calendar, bringing together diverse African communities as one force, culture, nation, and identity. Regardless of the level of diversity, the most important thing is to include everyone and give them the recognition they deserve. 2022. Journal of International Womens Studies -
Physical ageing in Se-Te-Sb glasses
Bulk Se60-xTe40Sbx glasses in the composition range 0?x?14 were prepared by the melt quenching method. Differential Scanning Calorimetric (DSC) and thermal crystallization studies were performed to understand the thermodynamic property like glass transition and structural transformations. These glasses exhibit sharp endothermic peak at the glass transition (Tg). Disappearance of the endothermic peak at Tg in the rejuvenated samples clearly indicates the ageing effect in these glasses. Addition of Sb to Se-Te increases the connectivity of the structural network which is evidenced from the increase in Tg. A distinct change in the slope of the Tg at x=6, indicates a major change in the way the network is connected. The glass forming ability and the thermal stability also exhibit a maximum at x=6. Tg increases with the ageing time and the corresponding fictive temperature (Tf) calculated from the specific heat curves shows a decreasing trend. The molecular movements along the polymeric Se chains might cause the structural relaxation and the physical ageing. The physical ageing effect has been understood on the basis of the Bond Free Solid Angle (BFSA) model proposed by Kastner. Thermally crystallized samples show the formation of rhombohedral Sb2Te 3, rhombohedral Sb2Se3 and hexagonal Te phases. 2013 Elsevier Ltd. -
Physical Co-location: an intersection of problem-solving and vicarious learning
Scholars have examined Revans' problem-solving praxeology in many contexts but have not fully explored the concept in the case of physical co-location. Hence, we focussed on investigating Revans' conceptualisation in a co-located context by paying particular attention to the different forms of learning' that emerged from it. The research setting for this study involved two coworking spaces in Bangalore, India, whose constituents were co-located start-ups and established enterprises. Held from January to March 2020, the study involved conducting exploratory, semi-structured interviews with twelve firms. The findings suggested that in a co-located environment, a) firms learnt vicariously' from a rich, external knowledge base during the enquiry-led Alpha phase b) firms learnt experientially', through learning by doing and reflecting in the implementation-focussed Beta phase c) firms learnt through the process of emergence that resulted from personal reflection and team interaction, in the revelatory Gamma phase. This study lends a novel direction in acknowledging that vicarious learning, that is, learning through the experience of others, serves as a starting point for problem-solving in a co-located context. We demonstrate that firms gain familiarity with the problem through vicarious sources, that is, from those experienced co-located firms who had journeyed on a similar path. 2021 Informa UK Limited, trading as Taylor & Francis Group. -
Physical fitness recommender framework for thyroid patients using restricted boltzmann machines
These days, people can easily acquire the information from online sources. Individuals are generally using recommendation services before buying products considering the availability of online. Recommendation systems propose the relevant services or products to users. But sometimes people face issues while retrieving health related information from the recommender systems. A focus on keeping people healthy is one way to address the serious societal concern of healthcare domain. A health-based physical recommender system suggests workout plans for users using their activity level and health condition. A personalized approach is the most effective solution for the fitnessbased recommender framework based on user's desired characteristics. This article presents a personalized fitness recommender system for thyroid patients. The proposed fitness recommender model integrates the user's data like personal and health profile, preferences, calorie intake, and activity level. The proposed hybrid model is built using Restricted Boltzmann Machines (RBM) integrating content based and matrix factorization techniques. The results of experiments prove that the proposed hybrid model outperforms than content based, pure RBM and matrix factorization recommendation techniques. The current proposal achieves the personalization approach by incorporating user's thyroid health condition and exercise preferences in recommendation process. The recommended result of hybrid RBM method is revised based on user's new preferences. 2020, Intelligent Network and Systems Society. -
Physical framework for a counselling environment in India: Thematic analysis of counsellors' perceptions
The influence of the physical environment on the counselling process is an inevitable part of a counselling session. However, there is little insight in Indian research into the desirable elements of the physical environment of the counselling room that helps facilitate a counselling session. Interviews were conducted with 10 professional counsellors in India. Thematic analysis of the databrought out various Basic and Organising themes under the following three Global themes: (a) Elements of the physical framework; (b) Counsellor's perspectives about the physical framework in counselling; and (c) Motivation to build a framework. The findings show how counsellors can systematise the physical framework to help construct the counselling session effectively. 2020 British Association for Counselling and Psychotherapy -
Physical properties of vapour grown indium monotelluride platelets
Indium monotelluride (InTe) crystals were grown from vapour phase under different temperature gradients by employing physical vapour deposition (PVD) method. The morphology of these crystals such as whiskers, needles, platelets etc., strongly depends on the temperature distribution in the horizontal dual zone furnace. InTe platelets were deposited by setting the temperature of the charge (TC) and growth (TS) zones at 1073 K and 773 K (?T=300 K), respectively, for different growth periods (24 h, 48 h, 72 h and 96 h). The surface growth features have been analyzed by scanning electron microscopes, which indicate layer growth mechanism for all the crystals. Various crystals grown under ?T=200 K and 300 K (retaining TS invariant) were examined by X-ray diffraction and elemental analysis. InTe samples exhibited consistent lattice parameters, density and atomic percentage, establishing stoichiometry and chemical homogeneity. The results obtained for Seebeck coefficient, electrical conductivity, power factor, dislocation density and microhardness are found to be reproducible as well. The vapour deposited InTe platelets are mechanically stable and possess high value of TEP, which ensure their practical application in thermoelectric power generation. 2014 Elsevier B.V. -
Physical properties of vapour grown indium monotelluride platelets /
Journal Of Crystal Growth, Vol.415, pp.81-87, ISSN No: 0022-0248. -
Physical vapor deposition and enhancement of optoelectronic properties of SnSe2 platelets
Stoichiometric tin diselenide (SnSe2) platelet crystals have been prepared by physical vapor deposition (PVD) method under high vacuum (~ 106mbar) using a homemade dual-zone furnace. The driving force for growth was optimized in terms of temperature difference (?T = 270 to 420C) of nutrient and growth zones. Good quality platelets, devoid of any screw dislocations, hillocks, defects etc. were crystallized at ?T = 400C by layer growth mode as per the 3D optical profiler and electron microscopic images. Rietveld refinement of the PXRD data using FullProf suite software justified hexagonal crystal structure with a = 3.811 c = 6.137and the computed density (5.967g/cm3) is in agreement with that obtained based on Archimedes principle. Chemical homogeneity of these samples was probed by EDAX, XPS and Raman analysis. The thermal and mechanical behavior was investigated by TGA as well as Vickers microhardness experiments. The values of optical band gap (1.20eV), absorption coefficient (7.25 105cm?1), resistivity (2.70 ? cm), mobility (32.70 cm2V?1s?1) and carrier concentration (3.08 1016cm?3) have been evaluated using UVVis-NIR, photoluminescence, and Hall effect measurements. The enhancement of optoelectronic parameters of the as-grown SnSe2 platelets free of polytypism, throws light on their potential for photovoltaic applications. 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.