[en] K-shell fluorescence yields are calculated for 17 ≤ Z ≤ 50 from detailed knowledge of K-shell vacancies and measured K X-ray intensities. (author). 24 refs

[en] A series of novel chloroquinoline based chalcones containing 1,2,3-triazole moiety were synthesized. All new compounds were characterized by ¹H NMR, ¹³C NMR, mass spectra and single crystal X-ray diffraction study. The absorbance, fluorescence spectra and quantum yield of all compounds were investigated in methanol. Photophysical properties of 1-(1-(7-chloroquinolin-4-yl)-5-methyl-1H-1,2,3-triazol-4-yl) -3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (3a) were investigated in detail. The effect of various solvents over emission spectra of 3a was studied using Kamlet–Taft and Catalan polarity scales. The quantum yield of 3a in various solvents was also recorded. The ground state and excited state dipole moments of compound 3a were determined using solvatochromic methods. The ground state dipole moment was estimated to be 1.081 D, while excited state dipole moment was found in the range of 11.969–3.801 D. Thermal stability of compound 3a and its precursor was also investigated using thermogravimetric analysis. - Highlights: • Novel quinoline based chalcones-1,2,3-triazole derivatives were synthesized. • The photophysical properties of all compounds were investigated in methanol. • The excited state and ground state dipole moment is estimated from various methods. • Kamlet–Taft and Catalan solvatochromism was investigated

[en] Perturbed angular correlation parameters in bovine serum albumin were determined using γ-γ sum peak method and time integral perturbed angular correlation technique, using ¹⁶⁰Tb as a probe. The attenuation coefficient decreases with an increase in the concentration of the environment resulting in an increase in the correlation time. (author) 16 refs.; 2 figs.; 2 tabs

[en] An X-ray fraction, efficiency and fluorescence yield independent method has been developed for the measurement of K-capture probabilities to the 437, 384, 161 and 81 keV levels in ¹³³Cs from the EC decay of ¹³³Ba. With errors minimized, the results are more precise compared with earlier works. (author)

[en] Samarium chloride coordinated with salicylic acid (SMS) and samarium chloride coordinated with two organic ligands glycine and salicylic acid (SMGS) have been grown by low temperature solution technique i.e., slow evaporation method. The crystalline nature of the material was firstly confirmed by single crystal X-ray diffraction analysis and secondly by powder X-ray diffraction analysis. It has been observed that the material prepared crystallizes in monoclinic system having space group P12₁/c1. The modes of vibration of different molecular group present in SMS and SMGS have been confirmed by Fourier transform infrared (FTIR) analysis. It indicates the coordination of ligands in complexes i.e., salicylic acid coordinated through oxygen atoms of carbonyl group (C=O) and glycine ligand coordinated through nitrogen atoms. UV–Vis transmittance study analyzes the optical transparency of SMS and SMGS and it has been found that with the incorporation of glycine in SMS transmittance decreases. Moreover, the impact of glycine in SMS single crystal on its various optical parameters such as optical band gap, refractive index and optical conductivity has been calculated. The decrease in the value of optical band gap from 3.43 to 3.29 eV with the incorporation of glycine in SMS has been observed. The calculated values of refractive index at 425 nm for SMS and SMGS complexes are 1.30 and 2.46 respectively and the optimum value of optical conductivity at 425 nm for SMS and SMGS is 4 $\times <!--\; ??\; -->$ 10⁵ and 1.4 $\times <!--\; ??\; -->$ 10⁷ Sm⁻¹ respectively. Luminescence of Sm³⁺ ion is strongly sensitized by salicylic acid as compared to glycine thereby fluorescence of the SMGS complex diminished. Decrease in the dielectric constant was observed with the incorporation of glycine in SMS single crystal. Complex electric modulus analysis confirms the non-Debye type of relaxation in both the materials. Activation energy value depends on frequency as well as on glycine coordination in SMS single crystal.

[en] Highlights: • A simple model for the spatial summation of excitatory inputs. • A small number of biophysically relevant parameters used. • Functional properties of postsynaptic neurons are studied. • Pre and postsynaptic responses are compared for stochastic and coherence resonance. Synaptic integration is a prominent aspect of neuronal information processing. The detailed mechanisms that modulate synaptic inputs determine the computational properties of any given neuron. We study a simple model for the summation of excitatory inputs from synapses and illustrate its use by characterizing some functional properties of postsynaptic neurons. In this regard, we study the response of postsynaptic neurons as defined by the model to two well known noise driven processes: stochastic and coherence resonance. The model requires a small number of parameters and is especially useful to isolate the role of integration mechanisms that rely on summation of inputs with little dendritic processing.

[en] In the present investigations, attempts were made to grow semi-organic composition of thiourea mixed with dysprosium chloride (abbreviated as TuDyCl). The growth of this semi-organic composition is being achieved by room-temperature slow evaporation technique. These were then characterised by using techniques like powder X-ray diffraction, scanning electron microscope (SEM), UV–Vis analysis, Fourier transformation infrared spectroscopy (FTIR), thermal and electrical studies. The composition crystallises in an orthorhombic crystal system having the space group Pnma . The crystallinity and purity were tested by powder X-ray diffraction. Structural morphology, as analysed using SEM, suggests the formation of microcrystals with certain inclusions. Optical spectra suggest a good optical transmission in the entire visible region and the lower cut-off wavelength at 278 nm. The absence of absorption of light in the visible region makes the crystals suitable for optoelectronic applications. The band gap comes out to be 4.24 eV. Other parameters like extinction coefficient, refractive index, optical and electrical conductivity were also analysed. Identification of the expected functional groups and various modes of vibrations present in the grown crystals was carried out by FTIR. Thermal effects, such as dehydration, melting and decomposition mechanism, were observed using thermoanalysis techniques. Electrical performance was tested to understand the electrical response of the materials with externally applied fields as a function of temperature and frequency. (author)

[en] Polypropylene films were irradiated with 120 MeV ²⁸Si⁹⁺ in the ion fluence range of 10¹²-10¹³ ions/cm². The spectral changes owing to ion bombardment were investigated by Fourier-transform infra-red spectroscopy. The isotactic nature of PPy remains unaffected. A band was observed at 1640 cm^-1 and its intensity was found to increase with ion fluence, confirming the formation of unsaturated linkage. Increase in chain length of hydrocarbon due to addition of more CH₂ group in the polymer was also confirmed by observing the increase of absorbance with ion fluence of CH₂ wagging vibration band at 1304 cm^-1. (author)

[en] Graphical abstract: Application of genetic algorithm optimization to control dissociation process in the ground electronic state of HF molecule is demonstrated. Highlights: ► Genetic algorithm optimization for the design of laser pulses. ► Control of dissociation process in the ground electronic state of HF molecule. ► Two types of pulses, one with fixed frequency components and the other having non-deterministic components. ► Optimized laser fields possess simple time and frequency structures. - Abstract: We have applied genetic algorithm optimization for the design of laser pulses to control dissociation process in the ground electronic state of HF molecule, within the mathematical framework of optimal control theory. In order to design the experimentally feasible laser fields, we coded the small set of selected field parameters in the GA parameter space. Two types of pulses, one with fixed frequency components and the other having non-deterministic components have been designed. Optimized laser field obtained using this approach, possesses simple time and frequency structures. We show that the fields having non-deterministic frequency components lead to greater dissociation probability compared to the ones having deterministic frequency components.

[en] Highlights: • Aqueous phase exfoliation of defect free graphene sheets employing nicotine based non-cytotoxic surface active ionic liquid (SAIL). • In-situ preparation of nanocomposite (NC) of Ag/AgBr janus nanoparticles (JNPs) and graphene sheets (Ag/AgBr@G) under sunlight. • Photo-degradation of an antibiotic, ciprofloxacin and organic dye, Rhodamine-B, respectively employing Ag/AgBr@G NC. • Enhanced photocatalytic activity of Ag/AgBr@G NC as compared to Ag/AgBr JNPs has been observed due to good electron-hole separation in prepared NC. Aqueous phase exfoliation of defect free graphene sheets is achieved employing nicotine based non-cytotoxic surface active ionic liquid (SAIL). The SAIL stabilizing the graphene acts as template, reducing agent and precursor of Br⁻ ions for in-situ preparation of of Ag/AgBr janus nanoparticles (JNPs) decorating graphene sheets under sunlight within 5 min of exposure, for the first time. Thus, prepared Ag/AgBr@Graphene nanocomposite (NC) shows 2.4–3.0 fold enhancement in photocatalytic activity towards degradation of an antibiotic, ciprofloxacin and Rhodamine-B dye, respectively in water under sunlight/visible light as compared to Ag/AgBr JNPs and other reported photocatalysts. Greater adsorption of contaminated molecules at Ag/AgBr@Graphene NC along with good elctron-hole separation lead to enhanced photocatalytic activity as compared to Ag/AgBr JNPs