Changes in the electronic structure and properties of graphene induced by molecular charge-transfer

Interaction with electron donor and acceptor molecules such as aniline and nitrobenzene brings about marked changes in the Raman spectrum and the electronic structure of graphene, prepared by the exfoliation of graphitic oxide.Comment: 13 pages, 4 figure

Two-Dimensional MXene Based Materials for Micro-Supercapacitors

With the boom in the development of micro-electronics for wearable and flexible electronics, there is a growing demand for micro-batteries and micro-supercapacitors (MSCs). Micro-supercapacitors have garnered a considerable attention for the evolution of these energy storage micro-systems. The choice of electrode material plays a pivotal role in the fabrication and development of MSCs. Recently, a new emerging family of two-dimensional transition metal (M) carbides or nitrides (X) cited as 2D MXene has emerged as a novel material. Due to its exceptionally high electronic conductivity ̴10,000 S cm−1, high charge storage capacity and easy processing capability helps to use MXene as the promising candidate for micro-supercapacitors electrodes. Taking the advantage of such exceptional properties. MXenes have been explored enormously in stacked as well as in interdigital architecture for on-chip micro-supercapacitors (MSCs). This book chapter includes a recent advancement of MXene based MSCs, with a brief overview of synthesis and fabrication techniques

SYNTHESIS, CHARACTERIZATION AND ANTIOXIDANT ACTIVITY OF POTASSIUM CIS-DIAQUA-BIS (OXALATO) CHROMATE (III) WITH LEVODOPA AND CARBIDOPA

Objective: These studies focus on the interaction between two clinically active antiparkinsonian drugs L-dopa (L) and carbidopa (C) with the cis-[Cr(C2O4)2(H2O)2]-and evaluation of the synthesized product from a coordination chemistry aspect with respect to the possibility of its antioxidant activity and its therapeutic application in the treatment of Parkinson disease.Methods: The resulting synthesized complexes were characterized by UV-VIS and FTIR spectroscopy. Evaluation of antioxidant activities of this cis-[Cr(C2O4)2(H2O)2]--L-dopa(ML), cis-[Cr(C2O4)2(H2O)2]--carbidopa(MC) and standard butylated hydroxytoluene (BHT) were carried out by using 1,1-diphenyl-1-picrylhydrazyl free radical (DPPH), 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cations and hydrogen peroxide method.Results: The results of spectral analysis of the synthesized products indicate that complexes have a Cr(III) ion coordinated via the carboxylic and amino group. In the reduction of radical DPPH· and the formation of radical monocation ABTS·+the ability to scavenge radical was measured in these experiments by the discoloration of the solution. However, in hydrogen peroxide method, the increased in absorbance showing its scavenging potential. The scavenging capacity of the test compounds and standard on the DPPH, ABTS·+, H2O2 decreased in the order BHT>ML>MC>C>L which were 98.4, 96.4, 86.4, 68.3, 49.7% for DPPH, BHT>ML>L>MC>C which were 99.3, 96.9, 96.3,66.6, 53.4% for ABTS·+, BHT>ML>MC>L>C which were 68.8%, 52.4%, 49.6%, 43.1% and 37.7% for H2O2 at the concentration of 50 µg/ml, respectively.Conclusion: The experimental findings showed that cis-[Cr(C2O4)2(H2O)2]--levodopa and cis-[Cr(C2O4)2(H2O)2]--carbidopa are having higher antioxidant potential than Levodopa and carbidopa although not superior to that of standard compound

Recent Developments in All-Solid-State Micro-Supercapacitors Based on Two-Dimensional Materials

Owing to their unique features such as high surface area, rich electroactive sites, ultrathin thickness, excellent flexibility and mechanical stability and multiple surface functionalities enables outstanding electrochemical response which provides high energy and power density supercapacitors based on them. Also, the Van der Waals gap between layered 2D materials encourages the fast ion transport with shorter ion diffusion path. 2D materials such as MXenes, graphene, TMDs, and 2D metal–organic frame work, TMOs/TMHs materials, have been described with regard to their electrochemical properties for MSCs. We have summarized the recent progress in MSC based on well-developed 2D materials-based electrodes and its potential outcomes with different architectures including interdigitated pattern, stacked MSC and 3D geometries for on-chip electronics. This chapter provides a brief overview of the recent developments in the field of 2D material based all-solid-state microsupercapacitors (MSCs). A brief note on the MSC device configuration and microfabrication methods for the microelectrodes have been discussed. Taking advantage of certain 2D materials such as 2D MXenes, TMDs, TMOs/TMHs that provide good surface chemistry, tunable chemical and physical properties, intercalation, surface modification (functionalization), heterostructures, phase transformations, defect engineering etc. are beneficial for enhancement in pseudocapacitance as it promotes the redox activity

Biochemical evaluation of dent corn (Zea mays L.) genotypes cultivated under rainfed conditions in the hills of north western Indian Himalayan state of Jammu and Kashmir

The aim of present study was to investigate protein, oil and fatty acid composition in 11 maize (Zea mays) genotypes collected from diverse locations in the hills of north western Indian Himalayan state of Jammu and Kashmir in order to get an idea about the extent of variability in these biochemical traits in the local germplasm. The study revealed significant variation in these quality traits. The protein content among the genotypes ranged from 10.7% to 18.7% while oil content varied between 2.26% and 4.80%. Higher protein content in some of the genotypes especially IC-0617877 (18.7%) and IC-0617880 (17.6%) is noteworthy. The saturated fatty acids of palmitic (C16:0), stearic (C18:0), arachidic (C20:0) and unsaturated fatty acids of oleic (C18:1), linoleic (C18:1) and elaidic (C18:1) were detected and quantified in these genotypes. Considerable variation has been recorded in fatty acid composition; 13.8-33.4% for palmitic acid, 21.5-48.1% for linoleic acid, 19.2-39% for oleic acid, 0.2-2.4% for elaidic acid, 2.5- 8.5% for stearic acid and 0.1-6.6% for arachidic acid. Higher oleic acid content recorded in all the genotypes excepting IC-0617881 is a useful trait. Strikingly, highest oil (4.80%), palmitic acid (33.4%), stearic acid (8.5%) and arachidic acid (6.6%) contents have been recorded in this remarkably cold tolerant genotype with reddish yellow seeds containing moderate protein content of 13.8 %. The appreciable variation in these quality traits could be exploited in breeding programmes for improvement of this crop and opening up new opportunities for its food and industrial end uses

Graphene-based electrochemical supercapacitors

Graphenes prepared by three different methods have been investigated as electrode materials in electrochemical supercapacitors. The samples prepared by exfoliation of graphitic oxide and by the transformation of nanodiamond exhibit high specific capacitance in aq. H2SO4, the value reaching up to 117 F/g. By using an ionic liquid, the operating voltage has been extended to 3.5 V (instead of 1 V in the case of aq. H2SO4), the specific capacitance and energy density being 75 F/g and 31.9 Wh kg−1 respectively. This value of the energy density is one of the highest values reported to date. The performance characteristics of the graphenes which are directly related to the quality, in terms of the number of layers and the surface area, are superior to that of single-walled and multi-walled carbon nanotubes

Observation of the Rare Decay of the η Meson to Four Muons

A search for the rare η→μ+μ−μ+μ− double-Dalitz decay is performed using a sample of proton-proton collisions, collected by the CMS experiment at the CERN LHC with high-rate muon triggers during 2017 and 2018 and corresponding to an integrated luminosity of 101  fb−1. A signal having a statistical significance well in excess of 5 standard deviations is observed. Using the η→μ+μ− decay as normalization, the branching fraction B(η→μ+μ−μ+μ−)=[5.0±0.8(stat)±0.7(syst)±0.7(B2μ)]×10−9 is measured, where the last term is the uncertainty in the normalization channel branching fraction. This work achieves an improved precision of over 5 orders of magnitude compared to previous results, leading to the first measurement of this branching fraction, which is found to agree with theoretical predictions

Search for new physics in multijet events with at least one photon and large missing transverse momentum in proton-proton collisions at 13 TeV

A search for new physics in final states consisting of at least one photon, multiple jets, and large missing transverse momentum is presented, using proton-proton collision events at a center-of-mass energy of 13 TeV. The data correspond to an integrated luminosity of 137 fb−1, recorded by the CMS experiment at the CERN LHC from 2016 to 2018. The events are divided into mutually exclusive bins characterized by the missing transverse momentum, the number of jets, the number of b-tagged jets, and jets consistent with the presence of hadronically decaying W, Z, or Higgs bosons. The observed data are found to be consistent with the prediction from standard model processes. The results are interpreted in the context of simplified models of pair production of supersymmetric particles via strong and electroweak interactions. Depending on the details of the signal models, gluinos and squarks of masses up to 2.35 and 1.43 TeV, respectively, and electroweakinos of masses up to 1.23 TeV are excluded at 95% confidence level