On the dipole–dipole correlation and dielectric anisotropy of some N(4-N-alkyloxy benzylidene)4′-N-alkylaniline compounds doped with silver nanoparticles

Dielectric study of the compounds N(4-n-heptyloxy benzylidene)4′-n-butylaniline and N(4-n-heptyloxy benzylidene)4′-n-hexylaniline at low frequency region (1 kHz–1 MHz) is performed using LCR meter (Agilent 4284 A). A qualitative interpretation in terms of dipole–dipole correlation for both the parallel and the perpendicular components of the dipole moment is given. Further study on the change in the dielectric permittivity and the dielectric anisotropy is made by doping the two compounds separately with dodecanethiol capped silver nanoparticles (0.25% by weight). The molecular positional ordering and relative smectic layer distance influences the change of degree (or type) of dipole–dipole pairing.     

Vector valued paranormed statistically convergent double sequence spaces

In this article we introduce the vector valued paranormed sequence spaces and defined over a seminormed space (X,q). We study their different properties like completeness, solidness, symmetry, convergence freeness etc. We prove some inclusion results.      

An experimental and theoretical high temperature kinetic study of the thermal unimolecular dissociation of fluoroethane

The thermal dissociation of fluoroethane has been studied using shock tube (ST)/time-of-flight mass spectrometry (TOF-MS) at 500 and 1200 Torr over the temperature range 1200-1550 K. The ST/TOF-MS experiments confirm that elimination of HF is the only reaction channel and rate coefficients for this reaction were extracted from concentration/time profiles derived from the mass spectra. Results from a novel diaphragmless shock tube coupled to the TOF-MS are also presented and demonstrate the unique ability of this apparatus to generate sufficiently reproducible shock waves that signal averaging can be performed over multiple experiments; something that is not possible with a conventional shock tube. The dissociation is also studied with ab initio transition state theory based master equation simulations. A modest increase in the calculated barrier height (i.e., by 1 kcal mol(-1)) yields predicted high pressure rate coefficients that are in good agreement with the existing literature data. The present pressure dependent observations are accurately reproduced for a downwards energy transfer for neon at 1200 to 1500 K of approximately 270 cm(-1), which is somewhat smaller than that found in previous studies on fluorinated ethanes with the same bath gases.     

Formic Acid as a Potential Pretreatment Agent for the Conversion of Sugarcane Bagasse to Bioethanol

In recent years, growing attention has been focused on the use of lignocellulosic biomass as a feedstock for the production of ethanol, a possible renewable alternative to fossil fuels. Several pretreatment processes have been developed for decreasing the biomass recalcitrance, but only a few of them seem to be promising. In this study, effect of various organic solvents and organic acids on the pretreatment of sugarcane bagasse was studied. Among the different organic acids and organic solvents tested, formic acid was found to be effective. Optimization of process parameters for formic acid pretreatment was carried out. The structural changes before and after pretreatment was investigated by scanning electron microscopy, X-ray diffraction (XRD), and Fourier transform infrared (FTIR) analysis. The X-ray diffraction profile showed that the degree of crystallinity was more for pretreated biomass than that of untreated. The FTIR spectra shown at the stretching of hydrogen bonds of pretreated sugarcane bagasse arose at higher number. It also revealed that the cellulose content in the solid residue increased because the hemicelluloses fraction in raw materials was released by acid hydrolytic reaction.     

Microbial synthesis of chitinase in solid cultures and its potential as a biocontrol agent against phytopathogenic fungus Colletotrichum gloeosporioides

Antifungal activity of chitinase can be effectively utilized in biologic pest control strategies. Because solid-state cultivation has been termed a cost-effective means for fungal growth and metabolite production, chitinase production by Trichoderma harzianum was studied using wheat bran-based solid medium containing 1% colloidal chitin. Chitinase synthesis was found to be growth associated because maximum enzyme (5.4 U/g of dry substrate) and biomass production occurred at 72h. Substrate moisture had a critical impact on chitinase production; five grams of medium having an initial moisture content of 68.4% when incubated for 72 h increased the enzyme yield to 9.3 U/g of dry substrate. Optimization of colloidal chitin concentration showed that improvements in chitinase yield and maximum activity were attained with a 2% (w/w) concentration. Supplementation of additional nitrogen sources also influenced enzyme production, and the best yield was obtained with yeast extract. The effect of crude chitinase on hyphal morphology of the phytopathogenic fungus Collelotrichum gloeosporioides was swelling as well as lysis of hyphal wall, depending on the age of the mycelium. Studies of pH and thermal stability showed that crude culture filtrate was active over pH 4.0–6.0 and retained about 48.2% activity after 40 min of incubation at 40°C.     

Synthesis,structural analysis,and visualization of poly(2‐ethynyl‐9‐substituted carbazole)s and poly(3‐ethynyl‐9‐substituted carbazole)s containing chiral and achiral minidendritic substituents

The synthesis of 2‐ethynyl‐9‐substituted carbazole and 3‐ethynyl‐9‐substituted carbazole monomers containing first‐generation chiral and achiral dendritic (i.e., minidendritic) substituents, 2‐ethynyl‐9‐[3,4,5‐tris(dodecan‐1‐yloxy)benzyl]carbazole (2ECz), 3‐ethynyl‐9‐[3,4,5‐tris(dodecan‐1‐yloxy)benzyl]carbazole (3ECz), 2‐ethynyl‐9‐{3,4,5‐tris[(S)‐2‐methylbutan‐1‐yloxy]benzyl}carbazole (2ECz*), and 3‐ethynyl‐9‐{3,4,5‐tris[(S)‐2‐methylbutan‐1‐yloxy]benzyl}carbazole (3ECz*), is presented. All monomers were polymerized and copolymerized by stereospecific polymerization to produce cis‐transoidal soluble stereoisomers. A structural analysis of poly(2ECz), poly(2ECz*), poly(3ECz), poly(3ECz*), poly(2ECz*‐co‐2ECz), and poly(3ECz*‐co‐3ECz) by a combination of techniques, including ¹H NMR, ultraviolet–visible, and circular dichroism spectroscopy, thermal optical polarized microscopy, and X‐ray diffraction experiments, demonstrated that these polymers had a helical conformation that produced cylindrical macromolecules exhibiting chiral and achiral nematic phases. Individual chains of these cylindrical macromolecules were visualized by atomic force microscopy. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3509–3533, 2002     

Nörlund and Riesz mean of sequences of fuzzy real numbers

In this article we study some properties of the Nörlund and Riesz mean of sequences of fuzzy real numbers. We establish necessary and sufficient conditions for the Nörlund and Riesz means to transform convergent sequences of fuzzy numbers into convergent sequences of fuzzy numbers with limit preserving.     

On a Class of Generalized Lacunary Difference Sequence Spaces Defined by Orlicz Functions

In this article we introduce the generalized lacunary difference sequence spaces [N_θ,M,Δ~m]_0,[N_θ,M,Δ~m]_1 and [N_θ,M,Δ~m]_∞using m~(th)- difference.We study their properties like completeness,solidness,symmetricity.Also we obtain some inclusion relations involving the spaces [N_θ,M,Δ~m]_0,[N_θ,M,Δ~m]_1 and[N_θ,M,Δ~m]_∞and the Cesàro summable and strongly Cesàro summable sequences.     

Thermodynamics of event horizon with modified Hawking temperature in scalar-tensor gravity

In recent past, Hawking temperature has been modified for the validity of thermodynamical laws at the event horizon in general relativity context. This lead to the introduction of modified Hawking temperature and it has been found that the modified Hawking temperature is more realistic on the event horizon. With this motivation, here we investigate the thermodynamical consistency of scalar-tensor gravity based models by examining the validity of the generalized second law of thermodynamics (GSLT) and thermodynamical equilibrium (TE) at the event horizon. In order to attain our goal, we consider a spatially flat Friedman–Robertson–Walker Universe filled with ordinary matter and the boundary of the Universe bounded by the event horizon that is in thermal equilibrium with modified Hawking temperature. Next, we calculate the general expressions for the GSLT and TE using modified Hawking temperature in the context of the more general action of scalar-tensor gravity where there is a non-minimally coupling between the scalar field and matter Lagrangian (as the chameleon field). From the general expression of GSLT, we find that the null energy condition must hold for a viable scalar-tensor model of the Universe dominated by a perfect fluid. Furthermore, in order to better understand these complicated general expressions of GSLT and TE, we explore the validity of the GSLT and TE for two viable models of scalar-tensor gravity namely Brans–Dicke gravity with a self-interacting potential and Chameleon gravity at the event horizon using special cosmological solutions. Finally, some graphical representation of the GSLT and TE have been presented. From the graphical analysis, we found that the power-law forms of the scale factor and scalar field is much favourable for the study of universal thermodynamics as compared to other choices of the scalar field and the analytic function.