School Of Basic And Applied Sciences
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Item Twisted helical armchair graphene nanoribbons: mechanical and electronic properties(Springer Science and Business Media Deutschland GmbH, 2021-05-08T00:00:00) Thakur, Rajesh; Ahluwalia, P.K.; Kumar, Ashok; Sharma, Munish; Sharma, RamanAbstract: The Hydrogen and Fluorine planar armchairs graphene nanoribbons (H & F AGNRs), subjected to twist deformation within fixed periodic boundary conditions. H-AGNRs is highly elastic in nature, though passivation with Fluorine does induce the plasticity when twisted beyond threshold torsional strain. This plasticity attributes to the wider bond length distribution suggests distortion of benzo-rings. The bandgap response to the effective strain of narrow GNRs N= 6 , 7 , and 8 get arranged as (i) monotonously increasing for q= 0 , 2 and (ii) decreasing for q= 1 ; here, q= mod(N, 3) in effective strain space (?2?2). The effective strain space is found to be more appropriate for gauging the response of torsional strain. This trend has also been observed for Fluorine passivated AGNRs; however, because of higher sensitive response to torsional strain, the bandgap of N= 7 F-AGNRs drops from Eg? 0.95 eV to Eg? 0.05 eV at extreme torsional strain forming Dirac cone at � K allows dissipationless transport to charge carriers of high kinetic energy at low bias. Graphic abstract: [Figure not available: see fulltext.] � 2021, The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature.Item Trends in small organic fluorescent scaffolds for detection of oxidoreductase(Elsevier Ltd, 2021-06-15T00:00:00) Sidhu, Jagpreet Singh; Kaur, Navneet; Singh, NarinderOxidoreductases are diverse class of enzymes engaged in modulating the redox homeostasis and cellular signaling cascades. Abnormal expression of oxidoreductases including thioredoxin reductase, azoreductase, cytochrome oxidoreductase, tyrosinase and monoamine oxidase leads to the initiation of numerous disorders. Thus, enzymes are the promising biomarkers of the diseased cells and their accurate detection has utmost significance for clinical diagnosis. The detection method must be extremely selective, sensitive easy to use, long self-life, mass manufacturable and disposable. Fluorescence assay approach has been developed potential substitute to conventional techniques used in enzyme's quantification. The fluorescent probes possess excellent stability, high spatiotemporal ratio and reproducibility represent applications in real sample analysis. Therefore, the enzymatic transformations have been monitored by small activatable organic fluorescent probes. These probes are generally integrated with enzyme's substrate/inhibitors to improve their binding affinity toward the enzyme's catalytic site. As the recognition unit bio catalyzed, the signaling unit produces the readout signals and provides novel insights to understand the biochemical reactions for diagnosis and development of point of care devices. Several structural modifications are required in fluorogenic scaffolds to tune the selectivity for a particular enzyme. Hence, the fluorescent probes with their structural features and enzymatic reaction mechanism of oxidoreductase are the key points discussed in this review. The basic strategies to detect each enzyme are discussed. The selectivity, sensitivity and real-time applications are critically compared. The kinetic parameters and futuristic opportunities are present, which would be enormous benefits for chemists and biologists to understand the facts to design and develop unique fluorophore molecules for clinical applications. � 2021 Elsevier B.V.Item Synergistic effect of pistachio shell powder and nano-zerovalent copper for chromium remediation from aqueous solution(Springer Science and Business Media Deutschland GmbH, 2021-07-06T00:00:00) Kumar, Sandeep; Brar, Ravinderdeep Singh; Babu, J. Nagendra; Dahiya, Amarjeet; Saha, Sandip; Kumar, AvneeshPistachio shell powder supported nano-zerovalent copper (ZVC@PS) material prepared by borohydride reduction was characterized using SEM, FTIR, XRD, TGA/DTA, BET, and XPS. SEM, XRD, and XPS revealed the nano-zerovalent copper to consist of a core-shell structure with CuO shell and Cu(0) core with a particle size of 40�100 nm and spherical morphology aggregated on PS biomass. ZVC@PS was found to contain 39% (w/w %) Cu onto the pistachio shell biomass. Batch sorption of Cr(VI) from the aqueous using ZVC@PS was studied and was optimized for dose (0.1�0.5 g/L), initial Cr(VI) concentration(1�20 mg/L), and pH (2�12). Optimized conditions were 0.1 g/L doses of sorbent and pH=3 for Cr(VI) adsorption. Langmuir and Freundlich adsorption isotherm models fitted well to the adsorption behavior of ZVC@PS for Cr(VI) with a pseudo-second-order kinetic behavior. ZVC@PS (0.1g/L) exhibits qmax for Cr(VI) removal up to 110.9 mg/g. XPS and other spectroscopic evidence suggest the adsorption of Cr(VI) by pistachio shell powder, coupled with reductive conversion of Cr(VI) to Cr(III) by ZVC particles to produce a synergistic effect for the efficient remediation of Cr(VI) from aqueous medium. Graphical abstract: [Figure not available: see fulltext.] � 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.Item Kinetic study of thermal degradation of flaxseed oil and moringa oil blends with physico-chemical, oxidative stability index (OSI) and shelf-life prediction(Springer, 2023-10-31T00:00:00) Srivastava, Yashi; Singh, Barinderjit; Kaur, Brahmeet; Ubaid, Mohammed; Semwal, Anil DuttThe thermal degradation kinetics of flaxseed oil (FSO) and moringa oil (MO) blends with soyabean oil (SOY; 80%), rice bran oil (RBO; 80%), cotton seed oil (CSO; 80%) and sunflower oil (SFO; 80%) with Rancimat equipment. There was no significant (p ? 0.05) difference observed in the specific gravity (SG), density (D), and refractive index (RI) values of the MO and FSO blends, while the rancidity parameters showed the opposite variations. The FTIR spectra showed absorption bands at 966�cm?1, 1097�cm?1, 1160�cm?1, 1217�cm?1, 1377�cm?1, 1464�cm?1, 1743�cm?1, 2945�cm?1, 2852�cm?1 and 3008�cm?1. Oil blends� kinetic degradation (Ea, ?H, ?S, A) is represented by the semilogarithmic relationship between the oxidative stability index (OSI) and temperature. The activation energy (Ea) ranged from 77.1 � 0.21 to 106.9 � 0.03�kJ/mol and 73.2 � 0.01 to 104.4 � 0.02�kJ/mol for flaxseed oil (FSO) and moringa oil (MO) blends, respectively. The enthalpy (?H) and entropy (?S) ranged from 67.3 to 121.6�kJ/mol, and ? 60.2 to ?�8.4�J/mol, and 63.55 to 95.59�kJ/mol and ?�20.66 to ? 4.11�J/mol for FSO blends and MO blends, respectively. Graphical Abstract: [Figure not available: see fulltext.] � 2023, Association of Food Scientists & Technologists (India).Item Kinetic study of thermal degradation of flaxseed oil and moringa oil blends with physico-chemical, oxidative stability index (OSI) and shelf-life prediction(Springer, 2023-10-31T00:00:00) Srivastava, Yashi; Singh, Barinderjit; Kaur, Brahmeet; Ubaid, Mohammed; Semwal, Anil DuttThe thermal degradation kinetics of flaxseed oil (FSO) and moringa oil (MO) blends with soyabean oil (SOY; 80%), rice bran oil (RBO; 80%), cotton seed oil (CSO; 80%) and sunflower oil (SFO; 80%) with Rancimat equipment. There was no significant (p ? 0.05) difference observed in the specific gravity (SG), density (D), and refractive index (RI) values of the MO and FSO blends, while the rancidity parameters showed the opposite variations. The FTIR spectra showed absorption bands at 966�cm?1, 1097�cm?1, 1160�cm?1, 1217�cm?1, 1377�cm?1, 1464�cm?1, 1743�cm?1, 2945�cm?1, 2852�cm?1 and 3008�cm?1. Oil blends� kinetic degradation (Ea, ?H, ?S, A) is represented by the semilogarithmic relationship between the oxidative stability index (OSI) and temperature. The activation energy (Ea) ranged from 77.1 � 0.21 to 106.9 � 0.03�kJ/mol and 73.2 � 0.01 to 104.4 � 0.02�kJ/mol for flaxseed oil (FSO) and moringa oil (MO) blends, respectively. The enthalpy (?H) and entropy (?S) ranged from 67.3 to 121.6�kJ/mol, and ? 60.2 to ?�8.4�J/mol, and 63.55 to 95.59�kJ/mol and ?�20.66 to ? 4.11�J/mol for FSO blends and MO blends, respectively. Graphical Abstract: [Figure not available: see fulltext.] � 2023, Association of Food Scientists & Technologists (India).