The geometry and the analytic properties of isotropic multiresolution analysis

In this paper we investigate Isotropic Multiresolution Analysis (IMRA), isotropic refinable functions, and wavelets. The main results are the characterization of IMRAs in terms of the Lax–Wiener Theorem, and the characterization of isotropic refinable functions in terms of the support of their Fourier transform. As an immediate consequence of these results, there are no compactly supported (in the space domain) isotropic refinable functions in many dimensions. Next we study the approximation properties of IMRAs. Finally, we discuss the application of IMRA wavelets to 2D and 3D-texture segmentation in natural and biomedical images.     

Fixed-bed study for adsorptive removal of furfural by activated carbon

In our previous study [A.K. Sahu, V.C. Srivastava, I.D. Mall, D.H. Latye, Sep. Sci. Technol. 43 (5) (2008) 1239], commercial grade activated carbon (ACC) was used for adsorptive removal of furfural from aqueous solution using batch studies. In the present study, continuous fixed-bed adsorption was carried out in ACC packed bed for the removal of furfural from aqueous solution. The effects of important factors namely bed height (Z = 15–60 cm), influent concentration of furfural (C_o = 50–200 mg/l), the flow rate (Q = 0.02–0.04 l/min) and column diameter (D = 2–4 cm) were studied. Capacity of the bed to adsorb furfural was found to increase with an increase in the value of Z, C_o and D; and with decrease in the value of Q. Adams–Bohart, Bed-Depth Service-Time, Thomas, Yoon–Nelson, Clark and Wolborska models were applied to the experimental data for the prediction of the breakthrough point, and to determine the characteristic parameters of the column. Error analysis showed that the Yoon–Nelson model best described the experimental breakthrough curve, while Wolborska model showed good prediction of breakthrough curve for the relative concentration region up to 0.5.     

Lepton distribution in top decay: A probe of new physics and top-polarization

We investigate the possibilities of studying new physics in various processes of t-quark production using kinematical distributions of the secondary lepton coming from decay of t quarks. We show that the angular distributions of the secondary lepton are insensitive to the anomalous tbW vertex and hence are pure probes of new physics in a generic process of t-quark production. The effects of t polarization on the distributions of the decay lepton are demonstrated for top-pair production process at a γγ-collider mediated by a heavy Higgs boson.      

B and collider physics: Working group report

This report summarises the work done during WHEPP-6 (Institute of Mathematical Sciences, Chennai, India, Jan 3–15, 2000) in Working group on ‘B and collider physics’.     

Viscosity control and reactivity improvements of cellulose fibers by cellulase treatment

Cellulase treatment for decreasing viscosity of cellulose (dissolving pulp) is a promising approach to reduce the use of toxic chemicals, such as hypochlorite in the dissolving pulp manufacturing process. In this study, the use of an endoglucanase-rich cellulase to replace the hypochlorite for this purpose and its improvements of the Fock reactivity were investigated. The results showed that at a given viscosity level, the replacement of hypochlorite treatment with a cellulase treatment in the bleach plant under otherwise the same conditions led to a higher Fock reactivity (72.0 vs 46.7 %). These results were due to the enzymatic peeling/etching mechanism, which partially peeled the primary wall of the fibers, thus improving the accessibility of fibers. The improved accessibility of the enzymatic treated pulp was supported by the positive fiber morphological changes determined, based on the SEM, BET and WRV methods. The alkali solubility results further supported the conclusion.     

One pot synthesis of α,β-epoxy ketones by oxidative coupling of methyl arenes with cinnamic acids involving C(sp3)―H activation and decarboxylative strategy

A new one pot oxidative coupling of methyl arenes with cinnamic acids has been developed for the synthesis of α,β-epoxy ketones using MnO₂/TBHP combination. The process involves a co-existing C(sp³)―H activation and decarboxylation under aqueous medium, which makes it practical and attractive.     

A lattice Boltzmann model for adsorption breakthrough

A lattice Boltzmann model is developed to simulate the one-dimensional (1D) unsteady state concentration profiles, including breakthrough curves, in a fixed tubular bed of non-porous adsorbent particles. The lattice model solves the 1D time dependent convection–diffusion–reaction equation for an ideal binary gaseous mixture, with solute concentrations at parts per million levels. The model developed in this study is also able to explain the experimental adsortption/desorption data of organic vapours (toluene) on silica gel under varying conditions of temperature, concentrations and flowrates. Additionally, the programming code written for simulating the adsorption breakthrough is modified with minimum changes to successfully simulate a few flow problems, such as Poiseuille flow, Couette flow, and axial dispersion in a tube. The present study provides an alternative numerical approach to solving such types of mass transfer related problems.     

Fourier Multipliers and Littlewood‐Paley for modulation spaces

In this paper we have studied Fourier multipliers and Littlewood‐Paley square functions in the context of modulation spaces. We have also proved that any bounded linear operator from modulation space into itself possesses an l₂‐valued extension. This is an analogue of a well known result due to Marcinkiewicz and Zygmund on classical ‐spaces.