Structural, Microstructural and Electrical Properties of Lanthanum (La+3)-Modified Lead Iron Niobate Pb(Fe0.5Nb0.5)O3

Lanthanum-modified Lead iron niobate ceramic oxides having chemical formula Pb(1-x)Lax(Fe0.5Nb0.5)(1-x/4)O3 (x=0.00, 0.02, 0.04, 0.06, 0.08) have been prepared using traditional solid state reaction route. Preliminary structural, microstructural and electrical studies were carried out by the powder x-ray diffraction, scanning electron microscopy and complex impedance spectroscopic technique in awide experimental conditions. The x-ray diffraction study confirmed the formation of perovskite structures of the newly modified ceramics. The lattice parameters were calculated using standard IUCR software CHECKCELL. Crystallite sizes of the samples were calculated from Williamson-Hall method. Microstructure/morphology of the materials was analyzed from SEM images. Dieletric and impedance spectroscopic studies of the materials were carried out as a function of temperature for a wide range of frequencies. The pure PFN ceramic oxide shows the phase transition from ferroelectric to paraelectric state around 1150C. There is a notable decrease in the transition temperature of La-PFN(x=0.02) ceramic and above 4% La concentration, the transition temperature falls below room temperature

ANATOMICAL AND BIOCHEMICAL ASPECTS OF THEVETIA PERUVIANA L. A COMMONLY PLANTED ROADSIDE TROPICAL SHRUB OF BHUBANESWAR, ODISHA

Objective: Air pollution is one of the most severe environmental problems of developing cities which adversely affects both plant and human life. However, roadside plants in the urban locations help in reducing the pollution level from the air through foliar surface and act as pollution sink. In this work, an attempt was made to understand the impact of air pollution on urban roadside plants which act as bio indicator.Methods: A study was conducted to check the impact of urbanization on air pollution by analyzing anatomical and biochemical aspects of Thevetia peruviana L. For anatomical analysis, the transverse sections of leaves were observed under a microscope; whereas for biochemical analysis, the estimation of chlorophyll, carotenoid and protein were determined by spectrophotometric methods. On the other hand, antioxidant enzyme assays, as well as specific activity staining, were performed to study the antioxidant potential. To investigate the antioxidant activity of the leaf extracts, an assay for catalase (CAT), guaiacol peroxidase (GPX) and superoxide dismutase (SOD) were performed. Isoforms of CAT, GPX and SOD were separated using native polyacrylamide gel electrophoresis (PAGE) and their activities were analyzed.Results: Analysis of data revealed that the anatomical disturbances significantly occurred in exposed plants of various sites. Among biochemical parameters, photosynthetic pigments such as chlorophyll a, chlorophyll b, total chlorophyll and carotenoid content were found to be decreased. A maximum (7.65±0.51, 3.78±0.56,11.43±0.91, 5.63±0.55 mg/g, respectively) decrement was noticed in leaves of the Pokhariput plant in comparison to Khorda NH5 (19.44±1.08, 10.12±1.03, 29.56±2.32, 10.22±1.21 mg/g, respectively) which is taken as control one. To determine the effect of air pollution on proteins, leaf extracts were analyzed by the Lowry method and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The substantial decrement of total protein and alteration in polypeptides were noticed in polluted sites. Meanwhile, the enhancement of antioxidant enzyme activities such as CAT, GPX and SOD were also detected.Conclusion: The increment of antioxidant enzymes and alteration of proteins, suggesting the activation of defensive mechanisms in selected plants under air pollution stress and also the plants made physiological and biochemical adjustments to overcome the oxidative damage

Insights Into Chemical Reactions at the Beginning of the Universe: From HeH+ to H3+

At the dawn of the Universe, the ions of the light elements produced in the Big Bang nucleosynthesis recombined with each other. In our present study, we have tried to mimic the conditions in the early Universe to show how the recombination process would have led to the formation of the first ever formed diatomic species of the Universe: HeH+, as well as the subsequent processes that would have led to the formation of the simplest triatomic species: H3+. We have also studied some special cases: higher positive charge with fewer number of hydrogen atoms in a dense atmosphere, and the formation of unusual and interesting linear, dicationic He chains beginning from light elements He and H in a positively charged atmosphere. For all the simulations, the ab initio nanoreactor (AINR) dynamics method has been employed

MUSiC : a model-unspecific search for new physics in proton-proton collisions at root s=13TeV

Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.Peer reviewe

Measurement of prompt open-charm production cross sections in proton-proton collisions at root s=13 TeV

The production cross sections for prompt open-charm mesons in proton-proton collisions at a center-of-mass energy of 13TeV are reported. The measurement is performed using a data sample collected by the CMS experiment corresponding to an integrated luminosity of 29 nb(-1). The differential production cross sections of the D*(+/-), D-+/-, and D-0 ((D) over bar (0)) mesons are presented in ranges of transverse momentum and pseudorapidity 4 < p(T) < 100 GeV and vertical bar eta vertical bar < 2.1, respectively. The results are compared to several theoretical calculations and to previous measurements.Peer reviewe

Measurement of B-c(2S)(+) and B-c*(2S)(+) cross section ratios in proton-proton collisions at root s=13 TeV

Peer reviewe

Development and validation of HERWIG 7 tunes from CMS underlying-event measurements

This paper presents new sets of parameters (“tunes”) for the underlying-event model of the HERWIG7 event generator. These parameters control the description of multiple-parton interactions (MPI) and colour reconnection in HERWIG7, and are obtained from a fit to minimum-bias data collected by the CMS experiment at s=0.9, 7, and 13Te. The tunes are based on the NNPDF 3.1 next-to-next-to-leading-order parton distribution function (PDF) set for the parton shower, and either a leading-order or next-to-next-to-leading-order PDF set for the simulation of MPI and the beam remnants. Predictions utilizing the tunes are produced for event shape observables in electron-positron collisions, and for minimum-bias, inclusive jet, top quark pair, and Z and W boson events in proton-proton collisions, and are compared with data. Each of the new tunes describes the data at a reasonable level, and the tunes using a leading-order PDF for the simulation of MPI provide the best description of the dat

Measurement of the W gamma Production Cross Section in Proton-Proton Collisions at root s=13 TeV and Constraints on Effective Field Theory Coefficients

A fiducial cross section for W gamma production in proton-proton collisions is measured at a center-of-mass energy of 13 TeV in 137 fb(-1) of data collected using the CMS detector at the LHC. The W -> e nu and mu nu decay modes are used in a maximum-likelihood fit to the lepton-photon invariant mass distribution to extract the combined cross section. The measured cross section is compared with theoretical expectations at next-to-leading order in quantum chromodynamics. In addition, 95% confidence level intervals are reported for anomalous triple-gauge couplings within the framework of effective field theory.Peer reviewe

Reconstruction of signal amplitudes in the CMS electromagnetic calorimeter in the presence of overlapping proton-proton interactions

A template fitting technique for reconstructing the amplitude of signals produced by the lead tungstate crystals of the CMS electromagnetic calorimeter is described. This novel approach is designed to suppress the contribution to the signal of the increased number of out-of-time interactions per beam crossing following the reduction of the accelerator bunch spacing from 50 to 25 ns at the start of Run 2 of the LHC. Execution of the algorithm is sufficiently fast for it to be employed in the CMS high-level trigger. It is also used in the offline event reconstruction. Results obtained from simulations and from Run 2 collision data (2015-2018) demonstrate a substantial improvement in the energy resolution of the calorimeter over a range of energies extending from a few GeV to several tens of GeV.Peer reviewe

Observation of the Production of Three Massive Gauge Bosons at root s=13 TeV

The first observation is reported of the combined production of three massive gauge bosons (VVV with V = W, Z) in proton-proton collisions at a center-of-mass energy of 13 TeV. The analysis is based on a data sample recorded by the CMS experiment at the CERN LHC corresponding to an integrated luminosity of 137 fb(-1). The searches for individualWWW, WWZ, WZZ, and ZZZ production are performed in final states with three, four, five, and six leptons (electrons or muons), or with two same-sign leptons plus one or two jets. The observed (expected) significance of the combinedVVV production signal is 5.7 (5.9) standard deviations and the corresponding measured cross section relative to the standard model prediction is 1.02(-0.23)(+0.26). The significances of the individual WWW and WWZ production are 3.3 and 3.4 standard deviations, respectively. Measured production cross sections for the individual triboson processes are also reported