EFG Studies at 111Cd in InBi Systems

TDPAC study of InBi_1−x Te _x with x=0.0, 0.01, 0.05, 0.1 and 0.2 as a function of temperature is done. Both pure and Te-doped samples show a semi-metallic character up to around room temperature. Above room temperature a steep transition to semiconducting state was observed, which is independent of the doping concentrations. Hence Te may be in the interstitial sites. Conductivity measurement of the above samples showed the same trend as observed in the EFG studies. Thus the importance of the conduction electron density is prominently seen in these systems. This revised version was published online in September 2006 with corrections to the Cover Date.     

Preparation and Thermal Investigation of Renewable Resource Based Terpolymer Bearing Furan Rings as Pendant Groups

Condensation of renewable resources based monomer 2-formylfuran (FF), vanillin (V) and 4-hydroxyacetophenone (HA) at 80°C by polycondensation in the presence of alkaline conditions (potassium hydroxide) gives an amorphous polymer resin in 85% yield. The structure of terpolymer was elucidated by FT-IR, ¹H-NMR and Pyrolysis GC-MS technique. The number average and weight average molecular weight and polydispersity index of the terpolymer were found to be 5,595 and 8,504 g/mol and 1.52, respectively by gel permeation chromatography (GPC). The phase transition temperature was determined by differential scanning calorimetry (DSC). Apparent activation energies of the thermal decomposition of terpolymer were determined using isoconversional Flynn-Wall-Ozawa (FWO) method. The type of solid-state mechanism has been established by Craido method is proposed to be D₃ (three-dimensional diffusion). The terpolymer strongly inhibited the growth of a wide variety of microorganisms, including gram-positive bacteria, gram-negative and fungi. This newly developed terpolymer furan resin may be an exciting intermediates material for the construction of 3D-designed structural products.     

A marketing-oriented inventory model with three-component demand rate dependent on displayed stock level (DSL)

This paper investigates a deterministic inventory system for single item with three-component demand rate. This rate is dependent on selling price, frequency of advertisement and displayed stock level (DSL) in a showroom/shop. Shortages, if any, are allowed and backlogged partially. The storage capacity of the showroom/shop is assumed to be limited (finite). Different scenarios and subscenarios of the system have been mentioned and developed. Some numerical examples are given to illustrate the model. A sensitivity analysis is performed graphically to investigate the effect of changes of the system parameters on the optimal average profit.     

Domino synthesis of indenols and alkyl-indene ethers under modified Vilsmeier conditions

Indenols are produced in high yields through domino reactions, when electron-rich trans-stilbenes and other trans aryl-alkyl olefins were subjected to Vilsmeier formylation in the presence of excess POCl₃ in a one-pot procedure. The method is even suitable for converting aryl-alkyl carbinols (precursors for olefins) directly into indenols. The corresponding indene ethers could be prepared in high yields directly when less reactive α,β-unsaturated aldehydes were subjected to cyclization in alcoholic HCl.     

A columnar mesophase from a disc-shaped molecule derived from triphenylamine: synthesis, mesomorphic behaviour and optical properties

The design and synthesis of a disc-like liquid crystalline compound using triphenylamine as a core has been achieved. The mesogenic properties were characterized by polarizing microscopy and differential scanning calorimetry and XRD studies. The compound existed as a hexagonal columnar mesophase. The fluorescence properties revealed the presence of intermolecular excimer formation.     

Comparative photophysical behaviour of naphthalene-linked crown ethers and aza crown ethers of varying cavity dimensions

A comparative time-resolved emission studies of several naphtho-crown ethers I–V, where metal ions can be complexed in a predetermined orientation with respect to the naphthalene (Naph) π-plane and naphthalene-linked aza crown ethers (L1 and L2) have been presented. In both the systems, crown ethers and aza crown ethers, naphthalene fluorescence gets quenched. In the systems I to V, the quenching is mainly due to efficient spin-orbit coupling (SOC) leading to greater population of the lowest triplet state of naphthalene. This SOC depends on the orientation of the crown ring with respect to the Naph-π-plane. However, in the systems L1 and L2, the quenching is due to photoinduced electron transfer (PET) from nitrogen lone pair of the aza crown ring to naphthalene moiety and consequent exciplex formation. The results have been interpreted using the time-resolved emission studies of all the compounds in various solvents, their alkali metal ion complexes, and protonated ligands.     

The first examples of terminally thiol-functionalized alkoxycyanobiphenyls

In this communication, we report the synthesis of the first examples of terminally thiol-functionalized alkoxycyanobiphenyls. The thermal behaviour of these mesogens and their intermediates was investigated by polarizing optical microscopy, differential scanning calorimetry and X-ray diffractometry.     

Metal nanoparticle-doped coloured films on glass and polycarbonate substrates

In a program on the development of metal (e.g. Au, Ag, Cu and their alloy) nanoparticles in sol-gel derived films, attempts were made to synthesize different coloured coatings on glasses and plastics. The absorption position of surface plasmon resonance (SPR) band arising from the embedded metal nanoparticles was tailored by controlling the refractive index of the matrix for the development of different colours. Thus different coloured (pink to blue) coatings on ordinary sheet glasses were prepared by generating Au nanoparticles in mixed SiO₂-TiO₂ matrices having refractive index values ranging from about 1.41 to 1.93. In another development,in situ generation of Ag nanoparticles in the inorganic-organic hybrid host leads to the formation of different abrasion resistant coloured coatings (yellow to pink) on polycarbonate substrates after curing. As expected, the SPR peak of Ag or Au is gradually red-shifted due to the increase of refractive index of the coating matrices causing a systematic change of colour     

Analytical study for investigating the behaviour of Nd-doped Glass, YAG and GGG under the heat capacity mode of operation

In this paper, detailed analytical studies on heat capacity operation in Nd-doped glass, YAG and GGG has been reported. The effect of the rising temperature on gain and hence on the output energy/power has been numerically worked out. The studies predicted that several kilowatts of the useful output power can be extracted out from the laser materials under investigation when operated under the heat capacity mode. The studies also revealed that output power levels can be scaled up by increasing the number of disks and by increasing the disk aperture size. The factors limiting the power enhancement are also discussed. The estimated results are in good agreement with the other reported experimental results.