South China Sea Summer Monsoon Onset in Relation to the Off-Equatorial ITCZ

Observations of the South China Sea summer monsoon （SCSSM） demonstrate the different features between the early and late onsets of the monsoon. The determining factor related to the onset and the resultant monsoon rainfall might be the off-equatorial ITCZ besides the land-sea thermal contrast. The northward-propagating cumulus convection over the northern Indian Ocean could enhance the monsoon trough so that the effect of the horizontal advection of moisture and heat is substantially increased, thus westerlies can eventually penetrate and prevail over the South China Sea （SCS） region.

OBSERVATIONAL ANALYSIS OF ASYMMETRIC DISTRIBUTION OF CONVECTION ASSOCIATED WITH TROPICAL CYCLONES “CHANCHU” AND “PRAPIROON” MAKING LANDFALL ALONG THE SOUTH CHINA COAST

Observational data of mesoscale surface weather stations and weather radars of Guangdong province are employed to analyze the asymmetric distribution of convection prior to, during and after landfall for tropical cyclones of Chanchu and Prapiroon making landfall on the south China coast in 2006. The results showed that strong convection is located in the eastern and northern sectors of the landfalling Chanchu and Prapiroon, namely in the front and right portions of the TC tracks, for a period of time starting from 12 h prior to landfall to 6 h after it. Their convection also had distinct differences in the vertical direction. The analysis indicated that although the landfall of Chanchu and Prapiroon has the same asymmetric distribution of convection, the causes are not exactly the same. The asymmetric distribution of convection in the case of Chanchu is mainly correlated with the impacts of a strong environmental vertical wind shear, low-level horizontal wind shear, and low-level convergence and divergence. In the case of Prapiroon, however, the asymmetric distribution of convection is mainly associated with the impacts of low-level convergence and divergence.

Tailoring the Meso-Structure of Gold Nanoparticles in Keratin-Based Activated Carbon Toward High-Performance Flexible Sensor

Flexible biosensors with high accuracy and reliable operation in detecting pH and uric acid levels in body fluids are fabricated using well-engineered metaldoped porous carbon as electrode material.The gold nanoparticles@N-doped carbon in situ are prepared using wool keratin as both a novel carbon precursor and a stabilizer.The conducting electrode material is fabricated at 500℃ under customized parameters,which mimics A-B type(two different repeating units) polymeric material and displays excellent deprotonation performance(pH sensitivity).The obtained pH sensor exhibits high pH sensitivity of 57 mV/pH unit and insignificant relative standard deviation of 0.088%.Conversely,the composite carbon material with sp^2 structure prepared at 700℃ is doped with nitrogen and gold nanoparticles,which exhibits good conductivity and electrocatalytic activity for uric acid oxidation.The uric acid sensor has linear response over a range of 1-150 μM and a limit of detection 0.1 μM.These results will provide new avenues where biological material will be the best start,which can be useful to target contradictory applications through molecular engineering at mesoscale.

Equilibrium folding and unfolding dynamics to reveal detailed free energy landscape of src SH3 protein by magnetic tweezers

Src SH3 protein domain is a typical two-state protein which has been confirmed by research of denaturant-induced unfolding dynamics.Force spectroscopy experiments by optical tweezers and atomic force microscopy have measured the force-dependent unfolding rates with different kinds of pulling geometry.However,the equilibrium folding and unfolding dynamics at constant forces has not been reported.Here,using stable magnetic tweezers,we performed equilibrium folding and unfolding dynamic measurement and force-jump measurement of src SH3 domain with tethering points at its N-and C-termini.From the obtained force-dependent transition rates,a detailed two-state free energy landscape of src SH3 protein is constructed with quantitative information of folding free energy,transition state barrier height and position,which exemplifies the capability of magnetic tweezers to study protein folding and unfolding dynamics.

Growth and Characterization of Guanidinium Trifluoroacetate – Second Harmonic Generation from a Centrosymmetric Crystal

Guanidinium trifluoroacetate (GTFA), a semi-organic non-linear optical material with molecular formula C3H6F3N3O2, has been synthesized at ambient temperature. Second harmonic generation (SHG) efficiency has been observed in this crystal though it crystallizes in centrosymmetric space group. Bulk single crystal of GTFA with a size of 22 x 7 x 2mm3 is successfully grown by submerged seed solution method. The grown crystals of GTFA have been subjected to various characterization studies such as X-ray diffraction, CHNS, FTIR analysis, UV-Vis spectrum, TGA/DTA, powder SHG test, laser damage threshold and microhardness studies.

Measurement of natural radionuclides in bricks and brick-making clays from Cuddalore district,Tamilnadu,India

In India,bricks as building materials are mainly prepared by clay using the deposited sediments of rivers,and the radionuclide contents in bricks and brick-making clays should vary with origin and geological condition.In this paper,the radionuclide contents of these materials from river bank areas of Cuddalore district,Tamilnadu India are measured by gamma ray spectrometer using NaI(Tl) detector,and compared with those of other countries.The radiation hazard indices,which are evaluated by radium-equivalent(Raeq) activity,are lower than that of NEA-OECD.

X-Ray Diffraction Study of Plasma Exposed and Annealed AlSb Bilayer Thin Film

Aluminum antimony seems to be a promising semiconducting material for high temperature applications, especially for transistors and P-N junction diodes. Additionally, it is a highly efficient solar material. This paper discusses the plasma induced bilayer diffusion of A1Sb bilayer thin films using X-ray diffractogram. A1Sb bilayer thin films were prepared on a glass substrate by vacuum evaporation technique. The effect of plasma exposure time and annealing temperature on the micro-structural parameters were investigated. X-ray diffraction studies show that the cubic crystals of A1 orient along the （111） plane and the hexagonal crystals of Sb orient along the （003） plane. Newly formed cubic crystals of A1Sb are oriented along the （200） plane and they are formed due to the simultaneous growth of A1 and Sb crystals during plasma exposure.

Force-dependent unfolding and folding dynamics of protein alpha-catenin modulation domains

α-catenin is an adhesion protein located at the cadherin-based cell-cell adherens junction.α-catenin cross-linksβ-catenin and actin fiber in the adhesion protein complex,and plays an important role in the formation and modulation of cell-cell adhesion.The central modulation domains can be unfolded to expose binding site of vinculin when stretching force is applied.Here,we studied the force-induced unfolding dynamics ofα-catenin modulation domains under different loading rates from which the unfolding distance of M2 and M3 domains is determined to be 5-7 nm,and an unfolding intermediate state is identified.We also found that the folding process of M1-M3 domains goes through different pathways with cooperativity.

Improved data analysis method of single-molecule experiments based on probability optimization

To extract the dynamic parameters from single molecule manipulation experiments, usually lots of data at different forces need to be recorded. But the measuring time of a single molecule is limited due to breakage of the tether or degradation of the molecule. Here we propose a data analysis method based on probability maximizalion of the recorded time trace to extract the dynamic parameters from a single measurement. The feasibility of this method was verified by dealing with the simulation data of a two-state system. We also applied this method to estimate the parameters of DNA hairpin folding and unfolding dynamics measured by a magnetic tweezers experiment.

Medicinal Plant Using Ground State Stabilization of Natural Antioxidant Curcumin by Keto-Enol Tautomerisation

Curcumin is a medicinal agent that exhibits anti-cancer properties and bioactive pigment in Turmeric has a huge thera-peutic value.It has a keto-enol moiety that gives rise to many of its chemical properties.A recent study has shown thatketo-enol tautomerisation at this moiety is implicated the effect of curcumin.The tautomerisation of curcumin in methanol.acetone and acetonitrile are used in nuclear magnetic resonance(^(1)H,^(13)C)spectroscopy.It was characterized using UV,IRand Raman spectral values.The molecular electrostatic potential surface of the Curcumin has been visualized in elec-tropositive potential in the region of the CH^(3+) group and most electronegative potential in the two oxygen atom has verystrong binding group.In the following,the modality of structural and thermo dynamical parameters,electrophilicity(ω).chemical potential(μ),chemical hardness(η) and electronic charge transfer confirms the local reactivity.The rate constantof tautomerisation of curcumin shows strong temperature dependence.Molecular electrostatic potential and Temperature dependence of various thermodynamic properties like(C^(0)_(p,m),S^(0)_(m),and H^(0)_(m))is increase with increase in temperature formonomer and dimer of various electrical fields.

Studies on the Effect of Ba²⁺on Growth, structural, Morphology, Optical, and Mechanical Properties of L-Valinium Picrate

Single crystals of undoped (pure) and barium nitrate (Ba (NO3)2)-doped L-Valinium Picrate (LVP) were grown from aqueous solution by slow evaporation technique. Morphological changes have been observed when Ba (NO3)2) is doped into LVP crystals. The dopant concentration in the crystals was measured by ICP technique. Slight changes in the unit cell parameter of LVP after doping with Ba (NO3)2) have been detected. The powder X-ray diffraction of the grown crystals has been recorded and the various planes of reflection identified shows shift in the peak positions. FTIR and UV spectra reveal the functional group identification and optical property of the grown crystals. The relative second harmonic generation (SHG) efficiency measurements revealed that both 5 and 10 mol % of Ba (NO3)2) in LVP enhanced the SHG efficiency by 92.85 and 160.59 times that of KDP respectively. However, at higher concentration, SHG efficiency is not increased but rather decreased from it undoped condition. Microhardness studies show that hardness number (Hv) increased with increase in load for all the grown crystals of this work.

Optical Conductivity and Dielectric Response of an Organic Aminopyridine NLO Single Crystal

This paper explores the correlation of electro-optical properties with dielectric properties of an organic single crystal. The optical constants of the organic aminopyridine single crystal have been studied. The second harmonic generation efficiency of the grown crystal, based on powder measurement, is 2.9 times higher than that of KDP. The real and imaginary part of the complex refractive index and dielectric constant of the crystal were determined. The optical and electrical conductivity of the grown crystal were studied.

Novel synthesis of cerium oxide nano photocatalyst by a hydrothermal method

Crystalline cubic cerium oxide nano particles have been synthesized from cerium(Ⅲ)nitrate(Ce(NO_(3))_(3).6H2_(O))and sodium hydroxide by a hydrothermal method.The effect of three different molar ratios of the NaOH precipitating agent on structural,optical,and photo catalytic activity was investigated.The synthesized cerium oxide nano particles were characterized by X-ray diffraction(XRD),a UV-vis spectrometer,scanning electron microscope(SEM),energy-dispersive X-ray spectroscopy(EDAX),Raman spectroscopy and X-ray photo electron spectroscopy(XPS).According to the findings,hydrothermally synthesized cerium oxide NPs have a high efficiency for photocatalytic degradation of methylene blue when exposed to UV light.Environmental water pollution is the major issue of the atmosphere.To get fresh water,humans could search the resources to purify the water in simple way and degradation is the one of the methods to purify salt water.

Grain boundary effect on structural, optical, and electrical properties of sol-gel synthesized Fe-doped SnO_(2) nanoparticles

Tin oxide(SnO_(2)) and iron-doped tin oxide(Sn_(1-x)Fe_(x)O_(2),x=0.05 wt%,0.10 wt%) nanoparticles are synthesized by the simple sol-gel method.The structural characterization using x-ray diffraction(XRD) confirms tetragonal rutile phases of the nanoparticles.The variations in lattice parameters and relative intensity with Fe-doping concentration validate the incorporation of iron into the lattice.The compressive strain present in the lattice estimated by using peak profile analysis through using Williamson-Hall plot also exhibits the influence of grain boundary formation in the lattice.The radiative recombination and quenching observed in optical characterization by using photoluminescence spectrum(PL) and the shift in the band gap estimated from UV-visible diffused reflectance spectrum corroborate the grain boundary influence.Raman spectrum and the morphological analysis by using a field emission scanning electron microscope(FESEM) also indicate the formation of grain boundaries.The compositional analysis by using energy dispersive x-ray spectrum(EDAX) confirms Fe in the SnO_(2) lattice.The conductivity studies exhibit that the impendence increases with doping concentration increasing and the loss factor decreases at high frequencies with doping concentration increasing,which makes the Sn_(1-x)Fe_(x)O_(2) a potential candidate for device applications.

Synthesis, Growth and Characterization of Benzophenone Added Sodium Acid Phthalate Crystal—A Potential Material for Nonlinear Optical Applications

Sodium acid phthalate C8H5NaO4 is one of the suitable semiorganic single crystals hired in second harmonic generation conversion applications. In the present work, optically transparent Benzophenone doped with sodium acid phthalate (SAPB) single crystals were grown successfully by slow evaporation solution technique. Single crystal XRD analyses exposed that the crystal lattice of SAPB crystal is a monoclinic crystal system with unit cell parameters a = 6.77 Å, b = 9.31 Å, c = 13.58 Å, and space group B2cb. The crystalline nature of SAPB material was confirmed by powder XRD pattern. The functional groups present in the grown crystals were identified by the FTIR analysis ranging between 4000 and 500 cm−1. The optical transparency and band gap of grown crystals were measured from UV-Visible spectroscopy. The fluorescence emission spectrum of the SAPB crystal having a strong Yellow emission peak at 574 nm and the red emission at 631 nm are identified. The Vickers microhardness number (Hv) increases with increasing load. Meyer’s index number (n) calculated from Hv shows that the material belongs to the soft material category. Preliminary measurement using Kurtz powder technique with Nd-YAG laser light of wavelength 1064 nm indicates that their second harmonic generation (SHG) efficiencies of the grown crystals were presented 2 times in comparison with Potassium Dihydrogen Phosphate (KDP) was confirmed.

Synthesis and Controllable Growth Dynamics of Third Order Nonlinear Optical Material of 2-Amino-4-Methylpyridinium 2-Chloro 4-Nitro Benzoate Electro-Mechanical Investigation and Device Fabrication

An organic nonlinear optical material 2-Amino-4-methylpyridinium 2-chloro 4-nitro benzoate (AMPCNB) was synthesized and large size single crystals were grown by slow evaporation solution growth method. Single crystal X-ray diffraction study showed that the title compound belongs to monoclinic crystal system with P21/n space group. A powder XRD study was performed to ascertain its phase. The UV–VIS-NIR study was performed to investigate the transparency window and lower cutoff wavelength of the compound, no absorption has been observed between 318 and 1100 nm. The third harmonic efficiency of the title compound has been studied using the Z-scan technique using continuous-wave Nd:YAG laser to confirm its saturable absorption and self-defocusing effect. The photo conducting and charge transport properties are analyzed using photoconductivity and dielectric measurements. Theoretical calculation of molecular polarizability, which is helpful in device fabrication, was carried out from Penn gap, Clausius-Mosotti equations and the obtained results were compared. Mechanical properties of the grown crystal were investigated by Vicker’s microhardness study.

Nitrogen Desorption and Positron Sensitive Defect of CVD Diamond

The chemical vapor deposition (CVD) process can produce single or poly-crystalline diamond samples of high purity or with controlled doping concentrations. The defect type in the CVD diamonds can be changed by heating the samples. Controlling the defect type can be used to create devices for quantum diamond switches that could be used in radiation sensors and quantum information technology. Eight samples of CVD diamonds were analyzed with Doppler broadening of positron annihilation radiation (DBAR) before and after annealing in high vacuum with an electron gun. Between temperatures of 1700 - 1850 K, nitrogen was liberated from the diamond sample. At these high temperatures, the surface was graphitized and a change in the color and transparency of the diamond was observed. Some of the samples were analyzed with DBAR during periods with and without light. The defect properties were observed to change depending on the time exposure to the positron beam and were then regenerated by exposure to light. The DBAR data is compared to photoluminescence data and a time varying defect state is discussed for detector and optical grade type II CVD diamonds.

Combined Experimental and Computational Investigation of 2-(2-Hydroxyphenylimino)Phenolic Derivatives:Synthesis,Molecular Structure and NLO Studies

A series of substituted 2-(2-hydroxyphenylimino) phenolic (salen) derivatives (1-4) have been synthesized and their structures of obtained compound were characterized by analytical, FT-IR, UV-Vis and 13C{1H}-NMR experimentally. The geometry structure optimization, frequencies (IR), NMR, electronic character, frontier molecular orbital (HOMO-LUMO) and first static hyperpolarizability (βtot) studies of reported compounds were calculated using DFT with B3LYP/6-311G(d,p) level of theory. The calculated HOMO and LUMO energies showed that charge transfer occurs within the molecule and from the MEP, the molecular stability and bond strength have been explained. In addition to that influence of energy gap (?Egap) between the HOMO-LUMO orbitals on the first static hyperpolarizability (βtot), we calculated the ?Egap for all the salen compounds. These results reveals that the smaller HOMO-LUMO ?Egap is, larger the βtot is.

Growth,Structural,Optical and Hardness Studies of Lithium Potassium Sulphate Single Crystals--An Inorganic NLO Material

Single crystal of lithium potassium sulphate, a nonlinear optical material, was grown from aqua solution by slow evapo- ration method at room temperature. The cell parameters were estimated by single crystal X-ray diffraction analysis. The optical transmittance of the crystal was recorded using the UV-Vis-NIR spectrophotometer and the optical band gap was calculated using this method. The second harmonic generation efficiency was measured by Kurtz and Perry powder technique and the phase-matching property was confirmed. The hardness of the material was measured by Vicker’s hardness test.

Study on Enhanced Antibacterial and Cytotoxicity of Pure and Cadmium Doped Cerium Oxide against Gram-Positive and Gram-Negative Bacteria

Pure and Cadmium (Cd) doped Cerium oxide nanoparticles (CeNPs) have been synthesised by the simple chemical co-precipitation technique. Cadmium ions of concentrations 1, 3 and 5 mol% were doped to investigate their influence on the structural and optical properties of CeO2. The synthesised samples have been subjected to X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis and high-resolution transmission electron microscopy (HRTEM). The XRD and Raman patterns have witnessed the cubic structure of the cerium oxide nanoparticles. The average particle size of CeO2 was found to be around 10 nm. SEM image has also ascertained that the grain size of pure CeO2 appeared is bigger than that of the Cd-doped, which intern indicates the grain growth upon doping. Besides, the antibacterial activity of the cadmium doped cerium oxide nanoparticles against some human pathogens revealed that they have exhibited the maximum zone of inhibition against gram-positive bacteria than the gram-negative species. Further, the cytotoxic effect of Cd-doped CeO2 sample is examined in cultured (MCF-7, A549 and Hep-2) cell.