Multiphoton dissociation/ionisation of dimethyl sulphide (CH3SCH3) at 355 and 532 nm

Multiphoton dissociation/ionization has been studied for CH₃SCH₃ at 355 and 532 nm using a time-of-flight mass spectrometer. The major ion signals observed at 355 nm are C⁺, CH₃ ⁺, HCS⁺, CH₂S⁺, CH₃S⁺ and CH₃SCH₃ ⁺. Power dependence studies at 355 nm show a (2+1) REMPI process for the formation of parent ion. Peaks atm/e = 46, 47 and 61 show two-photon laser power dependence whereasm/e = 15 and 45 peaks show four-photon dependence. However, in 532 nm photo-ionisation, no parent ion signal is observed. A peak atm/e = 35 corresponding to SH₃ ⁺ has been observed. SH₃ ⁺ has been suggested to originate from CH₃SCH₂ ⁺ via a cyclic transition state. Photoionisation results of CH₃SCH₃ have been compared with those of CH₃SSCH₃, at these two wavelengths.     

Mixed n-step MIR inequalities: Facets for the n-mixing set

Günlük and Pochet [O. Günlük, Y. Pochet, Mixing mixed integer inequalities. Mathematical Programming 90 (2001) 429–457] proposed a procedure to mix mixed integer rounding (MIR) inequalities. The mixed MIR inequalities define the convex hull of the mixing set $\{(y^1,\dots ,y^m,v)\in {\mathbb{Z}}^m\times {\mathbb{R}}_{+}:{\alpha }_1{y}^i+v\ge {\beta }_i,i=1,\dots ,m\}$ and can also be used to generate valid inequalities for general as well as several special mixed integer programs (MIPs). In another direction, Kianfar and Fathi [K. Kianfar, Y. Fathi, Generalized mixed integer rounding inequalities: facets for infinite group polyhedra. Mathematical Programming 120 (2009) 313–346] introduced the $n$-step MIR inequalities for the mixed integer knapsack set through a generalization of MIR. In this paper, we generalize the mixing procedure to the $n$-step MIR inequalities and introduce the mixed $n$-step MIR inequalities. We prove that these inequalities define facets for a generalization of the mixing set with $n$ integer variables in each row (which we refer to as the $n$-mixing set), i.e. $\{(y^1,\dots ,y^m,v)\in {(\mathbb{Z}\times {\mathbb{Z}}_{+}^{n?1})}^m\times {\mathbb{R}}_{+}:{\sum }_{j=1}^n{\alpha }_j{y}_j^i+v\ge {\beta }_i,i=1,\dots ,m\}$. The mixed MIR inequalities are simply the special case of $n=1$. We also show that mixed $n$-step MIR can generate valid inequalities based on multiple constraints for general MIPs. Moreover, we introduce generalizations of the capacitated lot-sizing and facility location problems, which we refer to as the multi-module problems, and show that mixed $n$-step MIR can be used to generate valid inequalities for these generalizations. Our computational results on small MIPLIB instances as well as a set of multi-module lot-sizing instances justify the effectiveness of the mixed $n$-step MIR inequalities.     

Medical applications of infrared thermography: A review

Abnormal body temperature is a natural indicator of illness. Infrared thermography (IRT) is a fast, passive, non-contact and non-invasive alternative to conventional clinical thermometers for monitoring body temperature. Besides, IRT can also map body surface temperature remotely. Last five decades witnessed a steady increase in the utility of thermal imaging cameras to obtain correlations between the thermal physiology and skin temperature. IRT has been successfully used in diagnosis of breast cancer, diabetes neuropathy and peripheral vascular disorders. It has also been used to detect problems associated with gynecology, kidney transplantation, dermatology, heart, neonatal physiology, fever screening and brain imaging. With the advent of modern infrared cameras, data acquisition and processing techniques, it is now possible to have real time high resolution thermographic images, which is likely to surge further research in this field. The present efforts are focused on automatic analysis of temperature distribution of regions of interest and their statistical analysis for detection of abnormalities. This critical review focuses on advances in the area of medical IRT. The basics of IRT, essential theoretical background, the procedures adopted for various measurements and applications of IRT in various medical fields are discussed in this review. Besides background information is provided for beginners for better understanding of the subject.     

Coulomb interaction energy of double acceptor in a semimagnetic Quantum Dot

The effect of magnetic field and the concentration of Mn²⁺ ion on the Coulombic interaction energy of a double acceptor impurity in a Cd_1−xMn_xTe/CdTe semimagnetic Spherical Quantum Dot is computed in the effective mass approximation using the variational principle. Results are presented and discussed.     

Ultrasonic Study of Collagen Solutions

Ultrasonic propagation characteristics of collagen solutions are reported. The concentration dependences of the various ultrasonic parameters of the solvent (acetic acid) and the solute (collagen) are compared. The ultrasonic velocities for acetic acid and collagen are comparable, while the attenuation is very high in collagen solutions. The adiabatic compressibility and the free length in collagen solutions decrease with increasing concentration. The relaxation time increases rapidly with concentration of collagen, unlike that for acetic acid.     

Inelastic neutron scattering and lattice dynamics of GaPO<Subscript>4</Subscript>

We report here measurements of phonon spectrum and lattice dynamical calculations for GaPO₄. The measurements in low-cristobalite phase of GaPO₄ are carried out using high-resolution medium-energy chopper spectrometer at ANL, USA in the energy transfer range 0–160 meV. Semiempirical interatomic potential in GaPO₄, previously determined using ab-initio calculations have been widely used in studying the phase transitions among various polymorphs. The calculated phonon spectrum using the available potential show fair agreement with the experimental data. However, the agreement between the two is improved by including the polarisability of the oxygen atoms in the framework of the shell model. The lattice dynamical models are also exploited for calculations of various thermodynamic properties of GaPO₄.     

Cascade One-Pot Synthesis of Orange-Red-Fluorescent Polycyclic Cinnolino[2,3-f]phenanthridin-9-ium Salts by Palladium(II)-Catalyzed C−H Bond Activation of 2-Azobiaryl Compounds and Alkenes

Quaternary ammonium salts were synthesized in moderate to good yields through double oxidative C−H bond activation on azobenzenes. The mechanism of the highly regioselective reaction of 2-azobiaryls with alkenes to give orange-red-fluorescent cinnolino[2,3-f]phenanthridin-9-ium salts and 15H-cinnolino[2,3-f]phenanthridin-9-ium-10-ide is proposed to involve ortho C−H olefination of the 2-azobiaryl compound with the alkene, intramolecular aza-Michael addition, concerted metalation–deprotonation (CMD), reductive elimination, and oxidation.     

Simple and Efficient One-Pot Synthesis of Nitriles from Amides and Oximes Using in Situ–Generated Burgess-Type Reagent

The dehydration of aldoximes and amides, and oxidation of benzoin are accomplished in one-pot using in situ–generated Burgess-type reagent.

Microwave-Mediated Modification of Selected Limonoids with DMAB Reagent and Antibacterial Studies

N,N-Dimethylaniline.borane (DMAB) is a stable, multifaceted electrophilic boron agent that displays hydroboration of C = C as well as selective reduction of functional groups under reflux, microwave, and ultrasound conditions. Natural products contain a plethora of functional groups that govern the specific bioactivity. It will be interesting to correlate the change in a functional group with the concern for change in bioactivity. Current research emphasizes the influence of microwave irradiation on moderately reactive DMAB reagent towards the functional group modification of selected limonoid-phytochemicals of Meliaceae family viz. cedrelone, azadirone, nimbin, and azadiradione. DMAB conveniently reduces the ketone, epoxide group into alcohol, and does a hydroboration reaction on the C = C bond. It does not show interest to reduce the ester group irrespective of 30 min of MW irradiation. Except for these reducing properties, the reagent DMAB unveils chemo-selective nature in respect of different functional groups and utilizes in an asymmetric synthesis. The coalescence of amine.borane with microwave irradiation brings forth a commodious and prompt method for the selective reduction of functional groups. The bioactive efficacy of modified phytochemicals is further taken for the antimicrobial studies.     

Mittag-leffler process

First-order autoregressive Mittag-Leffler process is studied. Methods for generating dependent (first-order autoregressive Markovian) sequences of random variables with Mittag-Leffier marginal distributions are discussed. Comparison of the first-order autoregressive Mittag-Leffler process with the first-order autoregressive exponential process of Gaver and Lewis [1] is done. As an application, the first-order autoregressive Mittag-Leffier process is fitted to weakly stream flows of the Kallada River in Kerala, India.