Search

Inorganic crystal lithium potassium sulfate (LKS) was grown by Sangaranarayanan-Ramasamy technique. Structural parameters of the grown LKS crystal were confirmed by single crystal X-ray diffraction analysis. LKS crystal belongs to hexagonal system with non-centrosymmetric space group P63. The functional elements presented in the compound were analyzed by ICP-OES test. Thermal property of the sample was evaluated by tracing TGA and DSC plots. UV–Vis spectral studies revealed the lower cut-off wavelength, transparency and band gap (4.9 eV) of LKS crystal. Multi-shot laser damage threshold value of LKS crystal was found to be 4.2 GW/cm2. Using Kurtz and Perry powder technique, the second harmonic generation (SHG) efficiency was found. The photoluminescence, dielectric, mechanical and etching studies were also studied to test the LKS crystal for NLO application.

Pure, 1%, 3%, and 5% of cerium-doped vanadium pentoxide (V2O5) nanoparticles were synthesized by non-aqueous sol-gel route. Synthesized samples were employed to various characterizations such as structural, morphological, optical, and electrochemical studies using XRD, SEM, FTIR, RAMAN, and UV-Vis DRS and cyclic voltammetry, charge-discharge, and cycle stability for supercapacitor applications. XRD analysis revealed the phase purity and crystallinity of the powder samples with a crystallite size 89–84 nm. SEM images show that the synthesized nanoparticles are highly monodispersed and homogenous in size. FTIR and RAMAN spectra ensured the presence of functional groups in synthesized V2O5. Then, the UV-Vis DRS spectra depict that the synthesized nanoparticles are red shifted. Ce(5%):V2O5 nanoparticles provided high specific capacitance about 555 Fg−1 at 1 Ag−1 and cycling stability up to 10,000 cycles with capacity retention up to 85% compared with pure, 1%, and 3% cerium-doped V2O5 nanoparticles. Thus, cerium-doped V2O5 nanoparticles were considered potential cathode materials for supercapacitor applications.

Hormesis phenomena in insect pests can have a negative impact, but for beneficial insects, it might be used to optimize mass rearing and increase the quality of biocontrol agents. Here, we report the multigenerational stimulatory effects of deltamethrin in a factitious laboratory host, Corcyra cephalonica, and the subsequent performance of its parasitoid, Habrobracon hebetor. The effects of sublethal (LC10), low lethal (LC15, LC20, LC25 and LC30) and median lethal (LC50) concentrations of deltamethrin along with the control were evaluated on biological traits and nutrient reserves of the host for three consecutive generations (G0, G1, and G2). The biological traits of C. cephalonica (fecundity, developmental duration and larval weight gain) did not differ significantly in the parental generation (G0), whereas in the later generation (G2), significant differences were observed with the control. Nutrient reserves (protein and lipid content) in C. cephalonica were significantly influenced by sublethal concentrations in all three generations (G0, G1, and G2). The performance of H. hebetor on the factitious host C. cephalonica (G2) revealed a significant increase in parasitoid fecundity of 65% when host larvae were exposed to LC15. However, no difference in hatch and pupation rates of parasitoids were observed across treatments. The emergence of both males and females and the longevity of only female wasps were significantly different. No effects were observed on male longevity. Taken together, insecticide-induced hormesis in host C. cephalonica, especially at LC15 exposure, stimulates the development of parasitoid H. hebetor without obvious major trade-off. The results might be helpful in mass rearing of H. hebetor as a biocontrol agent.

Hydrothermal method was used to prepare TiO2 nanoparticles with annealing temperature at 500 °C–700 °C. The mixture of anatase-rutile phase was investigated by powerful tool of X-ray diffraction (X...

Extensive use of imidacloprid in rice ecosystem may alter dynamics of microorganisms and can change soil biochemical properties. The objective of this study was to assess the effect of imidacloprid on growth and activities of microbes in tropical rice soil ecosystem. Four treatments, namely, recommended dose (at 25 g a.i. ha −1 , RD), double the recommended dose (at 50 g a.i. ha −1 , 2RD), five times the recommended dose (at 125 g a.i. ha −1 , 5RD) & ten times the recommended dose (at 250 g a.i. ha −1 , 10RD) along with control were imposed under controlled condition. Dissipation half lives of imidacloprid in soil were 19.25, 20.38, 21.65 and 33.00 days for RD, 2RD, 5RD and 10RD, respectively. In general bacteria, actinomycetes, fungi and phosphate solubilising bacteria population were disturbed due to imidacloprid application. Changes in diversity indices within bacterial community confirmed that imidacloprid application significantly affected distribution of bacteria. Total soil microbial biomass carbon content was reduced on imidacloprid application. Except dehydrogenase and alkaline phosphatase activities, all other soil enzymes namely, β-glycosidase, fluorescien diacetate hydrolase, acid phosphatase and urease responded negatively to imidacloprid application. The extent of negative effect of imidacloprid depends on dose and exposure time. This study concludes imidacloprid application had transient negative effects on soil microbes.

Hydroxyapatite/titanium dioxide composite thin films of different dipping cycle have been prepared by sol-gel processes. The morphology, chemical compositions and structures of the thin films were characterized by scanning electron microscope (SEM), Energy dispersive X-ray analysis (EDX). The crystalline phase and structure of the thin film nanocomposites were determined by XRD. The crystalline sizes of the composites were estimated in the range from 10 nm to 25 nm. The peak intensity of anatase phase increases with the increase of TiO2 concentration in the HAp/TiO2 composite there is no other impurity phases present in state. From the XRD peaks at 2θ = 31.724°, 31.706°, 31.731°, and 31.615° are the prominent characteristic peaks of HAp hexagonal phase. The addition of TiO2 clearly showed the development of rutile peaks at 2θ = 66.248°, 66.226°, 66.253°, and 66.146° which are the prominent characteristics peak of TiO2 rutile phases. The microstructural studies confirm that the HAp is embedded in the titania matrix. EDX analysis confirmed the presence of Ca, P, Ti and O respectively. The IR spectroscopy was performed on HAp/TiO2 thin films deposited on glass substrate. The stretching and vibrational properties of composites were reported the broad and medium peaks where observed at 440, 705 cm−1 which also indicates the titania with rutile phase. The optical absorbance coefficient of a semiconductor close to the band edge can be expressed by the optical bandgap of HAp/TiO2 composite films of 4, 6 and 8 dipping cycle is 3.8 eV, 4.0 eV and 4.1 eV respectively, from the literature the optical bandgap energy of HAp is 5.3 eV and TiO2 is 3.2 eV In our present study, significantly mid bandgap values have been observed. The antimicrobial activity test results showed that the composite films exhibited good inhibition on Gram positive and Gram negative bacteria.

Point pollution of pesticides originating from the washing of spraying machines could be controlled by biobed system and it is in use in temperate countries. The biobed system is yet to be established in tropical countries. An indigenous biobed system was prepared using local resources like rice straw, farm yard manures (FYM) and paddy field soil to suit the tropical climate. Lowermost 3 cm layer of the biobed system was filled with rice husk biochar to prevent leaching of pesticides from the system. This model system was tested with high doses of imidacloprid (178 mg/column), a commonly used pesticide against number of insect-pests in different crops, for its degradation. The bio-mix trapped a major part of the imidacloprid on the top most layer of the biobed column and only a very small part of imidacloprid recovered from the leachate. The biobed system could degrade 70.13% of applied imidacloprid within 15 days of the experiment and only 5.27% of the total pesticide recovered 90 days after incubation. Addition of biochar layer adsorbed imidacloprid from the outgoing leachate from the biobed column. Biomixture boosted microbial activity more particularly fungal population, which might be responsible for imidacloprid degradation. Microbial biomass carbon, and soil enzymes indicated faster dissipation of imidacloprid from the top layer of the biobed. This simple but efficient biobed system using local resources can fulfill the need of the small and marginal farmers of Asian countries for pesticide decontamination.

An experiment was set up to determine the rate of dissipation of chlorantraniliprole (CTP) from two soils with contrasting properties. The other objective of the study was to find out the effect of CTP on soil microorganisms (population, microbial biomass carbon and soil enzymes) under controlled environment. CTP residues when applied at recommended dose ((RD) (at 40 g a.i./ha)) could not be recovered either from alluvial soil or red soil at 60 days post application of CTP in a microcosm study. Higher clay content led to higher half-life in alluvial soil compared to red soil. CTP could not be recovered from RD treatment at 30 days after pesticide application under controlled environment. Faster dissipation of CTP was observed in rice rhizosphere soil with 23.89 and 34.65 days dissipation half-lives for RD and double the recommended dose (DRD) treatments, respectively. Different doses of chlorantraniliprole did not have considerable negative effect on actinomycetes, fungi, biological nitrogen fixers and phospahte solubilising bacteria except the bacteria population. Among the treatments, DRD recorded the lowest activity of dehyrodeganse, fluoresein diacetate hydrolase, acid and alkaline phosphatases followed by RD treatment. Microbial biomass carbon, β –glycosidase and urease did not vary significantly among the different doses of CTP. In general, RD did not have negative effcts on soil microbes. Hence, CTP can be recommeded in rice pest managment maintaining existing soil microbes and soil enzymes activity.

In the crystal of the title salt, C7H10N+·C3H3O4 −, the cations are linked to the anions via N—H...O and trifurcated N—H...(O,O,O) hydrogen bonds. The anions are linked into [010] chains by O—H...O hydrogen bonds. Taken together, these interactions generate (100) sheets.

In the title molecular salt, C6H10N22+·C6H9N2+·3C7H7O3S−, one of the cations is doubly protonated and one is singly protonated with charge balance achieved by three sulfonate anions. The crystal packing features N—H...O and C—H...O hydrogen bonds. The ions are arranged into a two-dimensional network along the (010) plane and the structure is further consolidated by weak C—H...π interactions.

The asymmetric unit of the title molecular salt, C7H10N+·C2Cl3O2−, consists of two cations and two anions. In the crystal, N—H...O hydrogen bonds link the components into [100] chains incorporatingR23(10) loops and weak π–π stacking [centroid-to-centroid distance = 3.865 (2) Å] is also observed.

Picolinium picrate monohydrate (PPM), an organic optical material, was synthesized and single crystals were grown by slow evaporation solution technique. The cell parameters of PPM were confirmed by single crystal X-ray diffraction analysis. The PPM crystals were subjected to FT-IR spectral analyses to confirm the synthesized compound. UV–vis–NIR spectral studies revealed that the optical transparency window of PPM crystal spreads over in the visible and NIR (480–900 nm) regions. From the transmittance data, the optical band gap as function of photon energy was estimated. The microhardness studies were carried out on PPM crystal. The laser damage threshold of PPM crystal was measured using Nd:YAG laser.

Bulk single crystals of pure and xylenol orange (XO) admixtured l -arginine phosphate (LAP) were grown by slow cooling technique. The cell parameters and crystallinity of pure and dye admixtured LAP crystals were confirmed by single crystal and powder X-ray diffraction analyses. HRXRD analysis reveals the presence of xylenol orange dye in interstitial site of LAP crystal lattice and it confirms the crystalline perfection of grown crystals. The functional groups of grown crystals were confirmed by FTIR spectral analysis. UV–vis transmission studies show the characteristic absorption of xylenol orange admixtured LAP crystal. Vickers’ microhardness and laser damage threshold studies were carried out on these crystals. Kurtz and Perry powder test was conducted to measure the second harmonic generation efficiency of pure and dye admixtured LAP crystals.

L-Arginine phosphate (LAP) and methylene blue dye admixtured L-arginine phosphate single crystals were grown by slow cooling technique and their cell parameters, crystalline perfection, dopant inclusion were confirmed by single crystal, powder X-ray diffraction and high resolution X-ray diffraction analyses respectively. The modes of vibrations of different functional groups present in pure and dye admixtured LAP crystals have been identified by FTIR spectral analysis. The UV-Vis-NIR spectral study was performed on the grown crystals and found that the crystals are transparent in the entire visible-NIR region. The dielectric measurement was carried out on the grown crystals as a function of frequency at room temperature. The microhardness hardness study on (100) plane of grown crystals reveals the mechanical behavior of the crystals. The laser damage threshold value significantly enhanced for dye admixtured crystal in comparison with pure LAP crystal. The relative SHG efficiency of methylane blue admixtured LAP crystal was found to be 1.3 times higher than that of pure LAP crystal.

L-asparagine L-tartrate (LAT), an organic compound has been synthesized from aqueous solution and bulk single crystal has been grown by slow evaporation technique. Powder X-ray diffraction studies confirmed the monoclinic structure of the grown LAT crystal. The presence of functional groups of the grown crystal was identified by FTIR studies. Linear optical property of the grown crystal was studied by UV-Vis spectral analysis. Microhardness studies reveal that the crystal possesses relatively higher hardness compared to other organic nonlinear optical crystals. Dielectric response of the L-asparagine L-tartrate crystal was analyzed for different frequencies at various temperatures. Kurtz-Perry powder second harmonic generation test confirmed the nonlinear optical properties of the as-grown LAT crystal.

In the title 1:1 adduct, C6H7N·C7H7NO2, the carboxylic acid group is twisted at an angle of 4.32 (18)° with respect to the attached benzene ring. In the crystal, the carboxylic acid group is linked to the pyridine ring by an O—H...N hydrogen bond, forming a dimer. The dimers are linked by N—H...O hydrogen bonds, generating (010) sheets.

Optical quality c -glycine single crystal of dimension 9 9 38mmhas been grown by slow coolingmethod in the presence of lithium nitrate. The third order nonlinear refractive index and nonlinearabsorption coefficient of the grown crystal were measured by Z-scan studies. The dispersion of birefrin-gence behaviour was studied by modified channelled spectrum method. The relative second harmonicgeneration efficiency of grown crystal was measured by Kurtz and Perry technique and phase matchingangle was also measured using Nd:YAG laser. 2012 Elsevier B.V. All rights reserved. 1. IntroductionIn the recent years, noncentrosymmetric bulk materials or polarcrystals are found to possess technologically useful properties suchas second and third harmonic generation (SHG; THG), piezoelectric-ity,pyroelectricityandferroelectricity,butSHGpropertyisofpartic-ular importance for its practical importance in areas such astelecommunication, lasers, optical storage and information process-ing[1–3]. The mostpopularnonlinearopticalmaterialsusedtogen-erate the SHG signal are of inorganic type bulk crystals with rathersmall second order nonlinear optical susceptibilities, such as KDP,Lithium triborate (LBO), b-Barium borate (BBO) and lithium niobate(LiNbO

In the title mol-ecular salt, C(6)H(6)NO(2) (+) (.)C(4)H(3)O(4) (-), the 2-carb-oxy-pyridinium cation is essentially planar with a maximum deviation of 0.003 (3) A. In the crystal, adjacent cations and anions are linked by an extensive system of weak N-H⋯O, O-H⋯O and C-H⋯O inter-actions, forming a layer parallel to the ab plane.

Picolinium maleate (PM), an organic material has been synthesised and single crystals were grown by slow evaporation technique. The structure of the grown crystal was elucidated by using single crystal X-ray diffraction analysis. PM crystal belongs to the monoclinic crystallographic system with space group P 2 1 / c . The crystalline perfection of the grown crystals was analyzed by high-resolution X-ray diffraction rocking curve measurements. The presence of functional groups in PM was identified by FTIR and FT-NMR spectral analyses. Thermal behaviour and stability of picolinium maleate were studied by TGA/DTA analyses. UV–Vis spectral studies reveal that PM crystals are transparent in the wavelength region 327–1100 nm. The laser damage threshold value of PM crystal was found to be 4.3 GW/cm 2 using Nd:YAG laser. The Kurtz and Perry powder second harmonic generation technique confirms the nonlinear optical property of the grown crystal.

Picolinium tartrate monohydrate (PTM), a novel organic nonlinear optical material was synthesized and bulk crystals were grown from aqueous solution by slow cooling technique. The cell parameters of the grown crystal were found by single and powder X-ray diffraction analyses. The crystalline perfection of the grown crystals has been analyzed by high-resolution X-ray diffraction (HRXRD) rocking curve measurements. The presence of functional groups in the grown crystal was identified by FTIR and FT-Raman spectral analyses. UV–Vis spectral studies reveal PTM crystals are transparent in the wavelength region of 295–1100 nm. The thermal characteristics of PTM were analyzed by TGA/DTA studies. The dielectric and mechanical behaviours of PTM crystals were investigated. Dislocation density was estimated to be 2.89 × 10 3 cm −2 on the flat-surface of PTM crystals from the etching studies. The laser induced surface damage threshold for the grown crystal was measured using Nd:YAG laser. Its second harmonic generation relative efficiency was measured by Kurtz and Perry powder technique and was observed to be comparable with KDP crystal.

Synthesis and growth of a novel organic nonlinear optical (NLO) crystal of 4-aminopyridinium maleate (4APM) in larger size by the slow evaporation solution growth technique are reported. Single crystal and powder X-ray diffraction analyses reveal that 4APM crystallizes in monoclinic system with space group P 2 1 with cell parameters a = 8.140(4) A, b = 5.457(5) A, c = 10.926(10) A and volume = 481.4(7) A 3 . The grown crystal has been characterized by Fourier transform infrared and UV–visible spectral analyses. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) have been carried out to study its thermal properties. Dielectric measurements have been carried out to study the distribution of charges within the crystal. The mechanical strength of the crystal has been studied by using Vickers’ microhardness test. The etching studies have been carried out on the grown crystal. The Kurtz and Perry powder SHG technique confirms the NLO property of the grown crystal and the SHG efficiency of 4APM was found to be 4.8 times greater than that of KDP crystal.