The Electronic Spectrum of Germanium Monosulfide: Rotational Structure in the A(1)Pi-X(1)Sigma(+) Transition in (70)GeS

The emission spectrum of the specific isotopomer (70)GeS was excited in a microwave (2450-MHz) discharge and the A(1)Pi-X(1)Sigma(+) transition (270-430 nm) was photographed under high resolution on a 10.6-m Ebert grating spectrograph. The rotational analysis of 43 bands led to the determination of accurate vibrational and rotational constants. Making use of these constants, the potential energy curves for the A(1)Pi and X(1)Sigma(+) states were generated by the RKR method and Franck-Condon factors and r-centroids were computed for the bands analyzed. The present extensive high-resolution study has revealed only a few localized perturbations in the A(1)Pi (v'=4, 5, 9) vibronic states, which contrasts with the situation in the isovalent molecules such as GeO, SiS, and SiSe. Copyright 2001 Academic Press.     

RFID-enabled track and traceability in job-shop scheduling environment

This study presents an RFID-based traceability approach to improve production scheduling. An in-depth study for a manufacturer is conducted to explore scheduling options enabled by an RFID-based traceability system. We propose a novel information visibility-based scheduling (VBS) rule that utilizes information generated from the real-time traceability systems for tracking work in processes (WIPs), parts and components, and raw materials to adjust production schedules. We then evaluate the performance of this information visibility-based schedule against the classical scheduling rules. The results of the simulation suggest that an RFID-based scheduling rule generates better performance compared to traditional scheduling rules with regard to cycle time, machine utilizations, backlogs, and penalty costs. We also observe that the value of this information visibility is more relevant when the demand varies widely and/or operational disruptions occur.     

High-resolution F T spectrum of A2Πr-X2Σ+ band system of MgCl

The emission spectrum of the A ² Π _r -X ² Σ ⁺ band system of MgCl molecule (360–380 nm) has been recorded on BOMEM DA8 Fourier transform spectrometer at an apodized resolution of 0.035 cm⁻¹. The spectra have been excited under flowing conditions in a demountable stainless steel hollow cathode lamp (400 V, 250 mA) containing anhydrous MgCl₂ and Ar. The resulting spectra are very intense and the 0-0, 1-1, 1-0 bands of A ² Π _1/2-X ² Σ ⁺ sub-transition and the 0-0 band of A ² Π _3/2-X ² Σ ⁺ sub-transition have been rotationally analyzed. Improved molecular constants have been derived using a least-squares fit program in which optical data of earlier analyzed 0-1 and 0-2 bands (A ² Π _1/2-X ² Σ ⁺) was also included. The Λ-doubling constants in the v′ = 0, 1 levels of the A ² Π _1/2 sub-state are as expected, i.e. p ₁ > p ₀, where as it is found that the spin-doubling constants of the v″ = 0, 1 and 2 levels of the ground state X ² Σ ⁺, decrease with the increase in v, i.e. γ ₀ > γ ₁ > γ ₂. This is indicative of the presence of some nearby state, influencing the spin-doubling.     

Effect of strain on stripe phases in the quantum Hall regime

Preferential orientation of the stripe phases in the quantum Hall (QH) regime has remained a puzzle since its discovery. We show experimentally and theoretically that the direction of high and low resistance of the two-dimensional (2D) hole gas in the QH regime can be controlled by an external strain. Depending on the sign of the in-plane shear strain, the Hartree-Fock energy of holes or electrons is minimized when the charge density wave (CDW) is oriented along the [110] or [110] directions. We suggest that shear strains due to internal electric fields in the growth direction are responsible for the observed orientation of CDW in pristine electron and hole samples.     

The effect of CuO and NiO doping on dielectric and ferroelectric properties of Na0.5Bi0.5TiO3 lead-free ceramics

In the present work, lead-free piezoelectric ceramics (Na_0.5Bi_0.5)TiO₃ –xCuO–yNiO (for x = 0.0, 0.02, 0.04 and 0.06) have been prepared by a conventional solid-state reaction method. An investigation of CuO and NiO doping in bismuth sodium titanate (BNT) and a study of the structure, morphology, and dielectric and ferroelectric properties of the NBT–CuNi system have been conducted. Phase and microstructural analysis of the (Na_0.5Bi_0.5)TiO₃ (NBT) based ceramics has been carried out using X-ray diffraction and scanning electron microscopy (SEM) techniques. Field emission scanning electron microscopy (FE-SEM) images showed that inhibition of grain growth takes place with increasing Cu and Ni concentration. The results indicate that the co-doping of NiO and CuO is effective in improving the dielectric and ferroelectric properties of NBT ceramics. Temperature-dependent dielectric studies have also been carried out at room temperature to 400 °C at different frequencies. The NBT ceramics co-doped with x = 0.06 and y = 0.06 exhibited an excellent dielectric constant ?_r = 1514. The study suggests that there is enormous scope of application of such materials in the future for actuators, ultrasonic transducers and high-frequency piezoelectric devices.     

Synthesis and Anticancer, Antiinflammatory,and Analgesic Activity Evaluation of Some Sulfa Drug and Acridine Derivatives

Summary.  Various sulfa drugs were condensed with 4-isothiocyanato-4-methyl-2-pentanone at pH∼3–5 by refluxing in methanol to give various substituted mercaptopyrimidines. On condensation with 9-chloro-2-substituted or -unsubstituted acridines, sulfathiazole gave the corresponding condensed products. N-Ethylaminoadenosine reacted with 9-chloroacridine to the coupled product. Condensation of sulfathiazole with 9-isothiocyanato-2,4-substituted or -unsubstituted acridines afforded the corresponding condensed compounds. The structures of all synthesized compounds were confirmed by spectroscopic methods. Anticancer, antiinflammatory, and analgesic activities of all compounds were investigated. Received November 18, 1999. Accepted (revised) January 12, 2000     

Advancement and future challenges of metal–organic coordination polymers: A case study of optical sensor for the detection of the environmental contaminants

Fast industrialization, increasing population, rapid urbanization, and the greediness of creamy layer in the society without the issues of caring the sustainability of ecosystem are the main out of many reasons behind the environmental catastrophe. The ecological balance is disturbed with the noxious materials generated from the uncontrolled use of modern science and technology and also unscientific and unsystematic societal growths. To save the modern civilization, a fast-track task is the monitoring of the toxic materials for the maintenance of sustainable ecological health and their utilization in a circular economy. Accordingly, optical methods are employed for the detection and estimation of environmental contaminants for immediate monitoring. The stability and structural tunability of the coordination polymeric (CPs) materials make them promising optical sensors for easy, low cost, reliable, selective, and sensitive detection of toxic ions/molecules. The crystallinity, thermal, mechanical, magnetic, and optical stability and flexibility of the CPs play a beneficial role for the accurate and stress-free recognition of the toxicants. In this review, the recent developments as well as the outlook on the sensing of pollutants at a very low concentration level using CPs as selective and specific sensors by spectro-fluorometric method are summarized. The progresses and challenges in the fabrication of hybrid materials and understanding their structure property correlations are described with an aim to motivate and facilitate the future researchers to perform research in the area.