An expeditious protocol for sesquiterpene-cored functionalized arenes from S-(−)-citronellal

An expeditious straightforward synthesis of sesquiterpene-cored arenes functionalized with electron-withdrawing or electron-donating substituents is described and illustrated by Michael addition of S-(−)-citronellal on functionalized 2H-pyran-2-one in a single step at room temperature. The reaction was further generalized by synthesizing isoprenylated 9,10-dihydrophenanthrene-2-carbonitrile using 5,6-dihydro-2-oxo-4-sec-amino-2H-benzo[h]chromene-3-carbonitriles and S-(−)-citronellal under similar reaction conditions.     

Signature inversion in theK=4− band in doubly-odd152Eu and156Tb nuclei: Role of theh 9/2 proton orbital

The phenomenon of signature inversion in the doubly-odd nuclei¹⁵²Eu and¹⁵⁶Tb is understood within the framework of a two-quasiparticle plus rotor model. It is shown that theh _9/2:1/2[541] proton orbital plays a crucial role in reproducing this phenomenon.     

Structural, dielectric and pyroelectric studies of Pb1−XCaXTiO3 thin films

Thin films of Pb_1−xCa_xTiO₃ [x=0.20, 0.24 and 0.28] have been prepared on ITO coated Corning glass substrates by sol gel technique. The perovskite phase of PCT films is formed at 650 °C with a polycrystalline tetragonal structure. The tetragonal factor (c/a) decreases with increasing Ca concentration. Dielectric, pyroelectric and ferroelectric studies have been carried out on these films. The effects of introduction of Ca ion in PbTiO₃ have also been discussed.     

Lattice dynamics of lithium oxide

Li₂O finds several important technological applications, as it is used in solid-state batteries, can be used as a blanket breeding material in nuclear fusion reactors, etc. Li₂O exhibits a fast ion phase, characterized by a thermally induced dynamic disorder in the anionic sub-lattice of Li⁺, at elevated temperatures around 1200 K. We have carried out lattice-dynamical calculations of Li₂O using a shell model in the quasi-harmonic approximation. The calculated phonon frequencies are in excellent agreement with the reported inelastic neutron scattering data. Thermal expansion, specific heat, elastic constants and equation of state have also been calculated which are in good agreement with the available experimental data.     

Sequence Analysis of KpnI Repeat Sequences to Revisit the Phylogeny of the Genus Carthamus L.

Repetitive DNA sequences constitute a significant proportion of eukaryotic genomes. Knowledge about the distribution of repetitive DNA sequences is necessary in order to gain insights into the organization, evolution and behavior of eukaryotic genomes. Therefore, we used two repetitive DNA sequences pCtKpnI-I and pCtKpnI-II, earlier reported in Carthamus tinctorius L. to study the phylogeny and to revise the taxonomic status of the taxa belonging to the genus. The study unraveled two major lines within the genus Carthamus; one line included all the diploid taxa (2n?=?24) and the other line comprised the taxa with 2n?=?20 and the polyploid taxa (2n?=?44 and 64). The results of the present study will prove useful in molecular breeding for improving some targeted agronomic traits in genus Carthamus.     

Complex permittivity,complex permeability and microwave absorption properties of ferrite–polymer composites

The complex permittivity (ε′–jε″), complex permeability (μ′–jμ″) and microwave absorption properties of ferrite–polymer composites prepared with different ferrite ratios of 50%, 60%, 70% and 80% in polyurethane (PU) matrix have been investigated in X-band (8.2–12.4 GHz) frequency range. The M-type hexaferrite composition BaCo⁺²_0.9Fe⁺²_0.05Si⁺⁴_0.95Fe⁺³_10.1O₁₉ was prepared by solid-state reaction technique, whereas commercial PU was used to prepare the composites. At higher GHz frequencies, ferrite's permeabilities are drastically reduced, however, the forced conversion of Fe⁺³ to Fe⁺² ions that involves electron hopping, could have increased the dielectric losses in the chosen composition. We have measured complex permittivity and permeability using a vector network analyzer (HP/Agilent model PNA E8364B) and software module 85071. All the parameters ε′, ε″, μ′ and μ″ are found to increase with increased ferrite contents. Measured values of these parameters were used to determine the reflection loss at various sample thicknesses, based on a model of a single-layered plane wave absorber backed by a perfect conductor. The composite with 80% ferrite content has shown a minimum reflection loss of −24.5 dB (>99% power absorption) at 12 GHz with the −20 dB bandwidth over the extended frequency range of 11–13 GHz for an absorber thickness of 1.6 mm. The prepared composites can fruitfully be utilized for suppression of electromagnetic interference (EMI) and reduction of radar signatures (stealth technology).     

Large neighborhood search for LNG inventory routing

Liquefied Natural Gas (LNG) is steadily becoming a common mode for commercializing natural gas. Due to the capital intensive nature of LNG projects, the optimal design of LNG supply chains is extremely important from a profitability perspective. Motivated by the need for a model that can assist in the design analysis of LNG supply chains, we address an LNG inventory routing problem where optimized ship schedules have to be developed for an LNG project. In this paper, we present an arc-flow formulation based on the MIP model of Song and Furman (Comput. Oper. Res., 2010). We also present a set of construction and improvement heuristics to solve this model efficiently. The heuristics are evaluated based on a set of realistic test instances that are very large relative to the problem instances seen in recent literature related to this problem. Extensive computational results indicate that the proposed methods are computationally efficient in finding optimal or near optimal solutions and are substantially faster than state-of-the-art commercial optimization software.     

Computational strategies for non-convex multistage MINLP models with decision-dependent uncertainty and gradual uncertainty resolution

In many planning problems under uncertainty the uncertainties are decision-dependent and resolve gradually depending on the decisions made. In this paper, we address a generic non-convex MINLP model for such planning problems where the uncertain parameters are assumed to follow discrete distributions and the decisions are made on a discrete time horizon. In order to account for the decision-dependent uncertainties and gradual uncertainty resolution, we propose a multistage stochastic programming model in which the non-anticipativity constraints in the model are not prespecified but change as a function of the decisions made. Furthermore, planning problems consist of several scenario subproblems where each subproblem is modeled as a nonconvex mixed-integer nonlinear program. We propose a solution strategy that combines global optimization and outer-approximation in order to optimize the planning decisions. We apply this generic problem structure and the proposed solution algorithm to several planning problems to illustrate the efficiency of the proposed method with respect to the method that uses only global optimization.     

Classical and Bayesian inference in two parameter exponential distribution with randomly censored data

This paper deal with the classical and Bayesian estimation for two parameter exponential distribution having scale and location parameters with randomly censored data. The censoring time is also assumed to follow a two parameter exponential distribution with different scale but same location parameter. The main stress is on the location parameter in this paper. This parameter has not yet been studied with random censoring in literature. Fitting and using exponential distribution on the range \((0, \infty )\), specially when the minimum observation in the data set is significantly large, will give estimates far from accurate. First we obtain the maximum likelihood estimates of the unknown parameters with their variances and asymptotic confidence intervals. Some other classical methods of estimation such as method of moment, L-moments and least squares are also employed. Next, we discuss the Bayesian estimation of the unknown parameters using Gibbs sampling procedures under generalized entropy loss function with inverted gamma priors and Highest Posterior Density credible intervals. We also consider some reliability and experimental characteristics and their estimates. A Monte Carlo simulation study is performed to compare the proposed estimates. Two real data examples are given to illustrate the importance of the location parameter.     

Amperometric immunosensor for the detection of Vibrio cholerae O1 using disposable screen-printed electrodes.

A disposable amperometric immunosensor was studied for the rapid detection of Vibrio cholerae (V. cholerae), the causative agent of cholera, employing an indirect sandwich enzyme linked immunosorbent assay (ELISA) principle. Screen-printed electrodes (SPEs) were fabricated (by using commercial and homemade carbon inks), electrochemically characterized and the assay conditions were optimized for capturing antibodies and antigen. Whole cell lysate (WCL) of V. cholerae was used to raise antibodies in rabbits and mice. The antibodies raised against WCL of V. cholerae were found to be specific, and no cross reactivity was observed with other enteric bacteria. 1-Naphthyl phosphate was used as a substrate with the amperometric detection of its enzymatic hydrolysis product 1-naphthol at a potential of +400 mV vs. Ag/AgCl reference electrode. A comparison between the amperometric detection technique and the standard ELISA was made in terms of the total assay time, the amount of biological materials used and the sensitivity of detection. The minimum detection limit of the amperometric immunosensor for V. cholerae was found to be 10(5) cells/ml in 55 min, while ELISA detected 10(6) cells/ml in 4 h.