Severe climate sway in coherent CDMA-OSSB-FSO transmission system

Free space optics (FSO) link at high transmission rate is delimited due to its perceptivity to diversified surroundings especially in hilly regions. A demonstration of CDMA-FSO coherent detection system is reported in this work to achieve a prolonged 10 Gbps-FSO link with acceptable SNR under the impact profound haze, rain and fog environment. Further, the work is extended to weigh the proposed CO-CDMA-OSSB-FSO transmission system against OFDM-OSSB-FSO direct detection system 0045 and 0050.     

Calorimetric investigation of Al–Zn alloys using Oelsen method

The results of calorimetric study of binary Al–Zn system done according to the Oelsen thermodynamic method are presented in this paper. Main thermodynamic properties, including activities, activity coefficients, partial/integral molar Gibbs excess, and mixing energies were determined at 1,000 K. Positive deviation from Raoult law was noticed, with minimal values of ΔG ^M about ?3 kJ mol^?1 and maximal values of ΔG ^E about +2 kJ mol^?1. The energetics of mixing in liquid Al–Zn alloys has been analyzed through the study of concentration fluctuation in the long-wavelength limit, and weak affinity between Al and Zn atoms in the system was observed. Differential thermal analysis and light optic microscopy were applied in the frame of characterization of investigated binary alloys and phase diagram examination, and the results obtained were in accordance with available literature data.     

Mobile interstitial model and mobile electron model of mechano-induced luminescence in coloured alkali halide crystals

A theoretical study is made on the mobile interstitial and mobile electron models of mechano-induced luminescence in coloured alkali halide crystals. Equations derived indicate that the mechanoluminescence intensity should depend on several factors like strain rate, applied stress, temperature, density of F-centres and volume of crystal. The equations also involve the efficiency and decay time of mechanoluminescence. Results of mobile interstitial and mobile electron models are compared with the experimental observations, which indicated that the latter is more suitable as compared to the former. From the temperature dependence of ML, the energy gaps between the dislocation band and ground state of F-centre is calculated which are 0.08, 0.072 and 0.09 eV for KCl, KBr and NaCl crystals, respectively. The theory predicts that the decay of ML intensity is related to the process of stress relaxation in crystals.     

Six coordinate Ni(II) complexes of ONN donor aroylhydrazone ligands: synthesis,spectral studies,and crystal structures

A new ligand N′-(pyridin-2-ylmethylene)nicotinohydrazide (HL²) and two Ni(II) complexes of stoichiometry NiL¹·H₂O [L¹-2-benzoylpyridine nicotinoylhydrazone] and NiL²·H₂O have been synthesized and characterized by elemental analyses, IR and UV–Vis spectral studies. Structures of HL² and Ni(II) compounds have been determined by single crystal X-ray diffraction studies which reveal a distorted octahedral geometry around the two Ni(II) centers.

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Graphical abstract A new ligand N￠-(pyridin-2-ylmethylene)nicotinohydrazide (HL2) and two Ni(II) complexes of stoichiometry NiL1·H2O [L1-2-benzoylpyridine nicotinoylhydrazone] and NiL2·H2O have been synthesized and characterized by elemental analyses, IR, UV–Vis spectral studies and single crystal X-ray analysis.

     

Gaussian Analytic Functions in the Polydisk

We study hyperbolic Gaussian analytic functions in the unit polydisk of \(\mathbb {C}^n\). Following the scheme previously used in the unit ball, we first study the asymptotics of fluctuations of linear statistics as the directional intensities \(L_j\), \(j=1,\dots ,n\) tend to \(\infty \). Then, we estimate the probability of large deviations of such linear statistics and use the estimate to prove a hole theorem. Our proofs are inspired by the methods of M. Sodin and B. Tsirelson for the one-dimensional case, and B. Shiffman and S. Zelditch for the study of the analogous problem for compact Kähler manifolds.     

One‐pot Synthesis of Highly Functionalized Tetrahydropyridines: A Camphoresulfonic Acid Catalyzed Multicomponent Reaction

A simple and straight forward solvent free method for the synthesis of a series of highly functionalized tetrahydropyridine derivatives has been achieved via multicomponent reaction of aromatic aldehydes, various amines, and β‐keto esters at room temperature using readily available (±)‐camphor‐10‐sulfonic acid as an organocatalyst. The current protocol offers an atom economic and environmentally benign method for the synthesis of the title compounds under solvent free conditions in good yields with high substrate scope and avoids column chromatographic purification.     

Application of HR-MAS NMR spectroscopy for studying chemotype variations of Withania somnifera (L.) Dunal

Withania somnifera (L.) Dunal (Solanaceae), commonly known as Ashwagandha, is one of the most valued Indian medicinal plants with a number of pharmaceutical and nutraceutical applications. Metabolic profiling has been performed by HR-MAS NMR spectroscopy on fresh leaf and root tissue specimens from four chemotypes of W. somnifera. The HR-MAS NMR spectroscopy of lyophilized defatted leaf tissue specimens clearly distinguishes resonances of medicinally important secondary metabolites (withaferin A and withanone) and its distinctive quantitative variability among the chemotypes. A total of 41 metabolites were identified from both the leaf and root tissues of the chemotypes. The presence of methanol in leaf and root tissues of W. somnifera was detected by HR-MAS NMR spectroscopy. Multivariate principal component analysis (PCA) on HR-MAS (1) H NMR spectra of leaves revealed clear variations in primary metabolites among the chemotypes. The results of the present study demonstrated an efficient method, which can be utilized for metabolite profiling of primary and secondary metabolites in medicinally important plants.