On Linear Codes over $${\mathbb{Z}}_{2^{s}}$$

In an earlier paper the authors studied simplex codes of type α and β over and obtained some known binary linear and nonlinear codes as Gray images of these codes. In this correspondence, we study weight distributions of simplex codes of type α and β over The generalized Gray map is then used to construct binary codes. The linear codes meet the Griesmer bound and a few non-linear codes are obtained that meet the Plotkin/Johnson bound. We also give the weight hierarchies of the first order Reed-Muller codes over The above codes are also shown to satisfy the chain condition.A part of this paper is contained in his Ph.D. Thesis from IIT Kanpur, India     

Measurement of cosmogenic radionuclides in meteorites with a sensitive gamma-ray spectrometer

Summary A large-volume HPGe gamma-ray spectrometer in a NaI(Tl) well has been set up underground at 70 m.w.e. depth for whole body counting of cosmogenic radionuclides in meteorites. The detectors are housed in a 20 cm thick lead shield with a lining of cadmium and OFHC copper. The scintillator is simultaneously operated in anticoincidence as well as in coincidence in selected energy channels to achieve low background levels (in the range of counts per day) and high specificity. In this way a large number of radionuclides such as²⁶Al,⁴⁴Ti,⁶⁰Co,²²Na,⁵⁴Mn, and shorter-lived nuclides produced in extraterrestrial materials like meteorites and lunar rocks can be analysed. Results on Bouvante and Bereba achondrites and Dhajala and Torino chondrites are presented. Due to the relevance of its scientific content, this paper has been given priority by the Journal Direction.     

Mixed micelles of benzyldimethyltetradecylammonium chloride with tetradecyltrimethylammonium and tetradecyltriphenylphosphonium bromides: a head group contribution

Mixed micelle formation by tetradecyltrimethylammonium (TTAB) and tetradecyltriphenylphosphonium bromides (TTPB) with benzyldimethyltetradecylammonium chloride (BTDACl) was studied with the help of conductivity and Kraft point measurements. The BTDACl + TTAB mixtures showed synergistic interactions whereas those of BTDACl + TTPB indicated weak antagonistic behavior. From Kraft temperature measurements, the enthalpy of fusion (H(1)(0)) from solid hydrated BTDACl to the liquid state in the presence of TTAB or TTPB was computed. It was found that DeltaH(1)(0) was much more positive for BTDACl + TTPB than for BTDACl + TTAB mixtures.     

N-Substituted Amido Derivatives of Lanthanides

The synthesis of lanthanide amido complexes of the type Ln(CH₃CONR)₃ (I), (OPrⁱ)Ln(C₆H₅CONC₆H₅)₂ (II), and (OBu^t)Ln(C₆H₅CONC₆H₅)₂ (III) [where Ln = La, Pr, Nd; R = C₆H₅, p-NO₂C₆H₄, p-BrC₆H₄] are described. Infrared spectra indicate deprotonation of the secondary amide (anilide). Anion coordination is proposed as chelating bidenate ligands.     

Wide spectrum H2O sources—astrophysical Raman masers

The extraordinarily wide 22 GHz emission from W49A and two other galactic HII regions is discussed, and arguments presented why the entire width of these spectra cannot be attributed to the 6₁₆ → 5₂₃ transition of H₂O. It is suggested that most of the weak emission with large frequency shifts is due to stimulated Raman scattering of the strong central features appearing at the expected frequency of the water vapour line. It has not been possible to identify the scattering agent, but it is predicted that the spectra of millimetre-wave maser sources should also show such frequency-shifted features.     

Electroanalysis of Carbendazim using MWCNT/Ca‐ZnO Modified Electrode

The present research involves the report on electrochemical deportment of Carbendazim (MBC) at multiwalled carbon nanotubes and calcium‐doped zinc oxide nanoparticles altered nanocomposite based carbon paste electrode (MWCNTs/Ca‐ZnO‐CPE). The modified carbon paste evidenced manifest electrocatalytic behavior for MBC in 0.2 M phosphate buffer (PB) solutions. Cyclic voltammetry (CV), linear sweep voltammetry (LSV), and square wave voltammetry (SWV) techniques were used for the analysis. The working electrode assembly exhibits faster electron transfer of MBC with increase in the peak current. At bare CPE, MBC showed maximum peak current of 1.098 μA at potential 0.7568 V whereas at MWCNT/Ca‐ZnO/CPE peak current of 5.203 μA was observed at potential 0.7541 V in 0.2 M PBS of pH 7.0 at the sweep rate of 50 mV s^?1. The synthesized 5 % Ca‐ZnO nanoparticles (NPs) were characterized by X‐ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive X‐ray analysis (EDX), and Transmission electron microscopy (TEM) analysis. Various factors influencing the voltammetry of MBC such as pre‐concentration time, pH, sweep rate, and amount of MBC were studied and from the studies we observed that the response was found to be diffusion‐controlled. The concentration variation studies for MBC was watched in the linear working range of 0.01 μM to 0.45 μM and the detection limit was found by SWV technique.     

Spectrophotometric Studies of V(V) Complexes of N-Methylaminothioformyl-N′-phenylhydroxylamine

The violet-colored complexes of V(V) and N-methylaminothio-formyl-N′-phenylhydroxylamine are extractable into chloroform. The spectrophotometric studies have shown that 1:3 and 1:4 (metal:ligand) complexes predominate in the acidity range 6.5–9 N and 9.5–10.5 N HCl, respectively. The values of stability constants, stepwise and overall, have been calculated by following extended Leden and Yatsimirskii methods. The analytical suitability of the reagent for the microdetermination of vanadium has also been investigated.     

Nafion‐modified Carbon Based Sensor for Soil Potassium Detection

In the present investigation, we report a voltammetric sensor based on Nafion modified screen printed carbon ink functionalized with 4‐aminobenzo‐18‐crown‐6 ether for the detection of soil potassium. The potassium is one of the major nutrient elements required by the plants and is critical for the crop productivity. The selective and sensitive assay is based on recording change in current signal of a positively charged redox probe, hexammineruthenium(III)chloride in the absence and presence of K⁺ ion in solution. The sensing interface is highly stable and reproducible for detection of K⁺ ion a under a wide range of concentration 1 to 500 ppm. The detection sensitivity over a wide concentration range was achieved by altering the concentration of redox species. Mechanistically, the recognition properties of 4‐aminobenzo‐18‐Crown‐6 covalently bound to the Nafion on carbon surface was found to be selective for potassium ion over sodium, ammonium and calcium ion. Potassium recognition through host‐guest binding of crown ether derivative and proposed simplicity of fabrication protocol makes the systems highly promising for real‐time applications in soil analysis.     

Boundary integral equation formulation for generalized thermoelastic diffusion – Analytical aspects

The present work deals with the formulation of the boundary integral equations for the solution of equations under linear theory of generalized thermoelastic diffusion in a three-dimensional Euclidean space. A mixed initial-boundary value problem is considered in the present context and the fundamental solutions of the corresponding coupled differential equations are obtained in the Laplace transform domain by employing the treatment of scalar and vector potential theory. A reciprocal relation of Betti type is established. Then we formulate the boundary integral equations for generalized thermoelastic diffusion on the basis of these fundamental solutions and the reciprocal relation.     

High-temperature thermal transport in heavily doped small-grain-size lead telluride

An improved theoretical model has been used to analyse the high-temperature thermal conductivity of dopedn-type lead telluride in terms of the separate contributions from electrons and phonons. At high carrier concentrations the electronic thermal conductivity is significant and the non-parabolic nature of the energy bands must be included to obtain a reasonable agreement with experimental thermal conductivity data. Although acoustic phonon scattering is the dominant carrier scattering mechanism, the inclusion of polar optical mode scattering further improves the agreement between the theoretical results and experimental data. The improved model is employed to estimate the effect of grain-boundary scattering in reducing the thermal conductivity of small-grain-size material. At optimum doping the thermal conductivity of 1 m grain size unalloyed lead telluride would be reduced by approximately 5% compared with the single-crystal data.On leave from the University of Allahabad, India