Ultrasound-assisted Acid red dye removal using leather fibre wastes as matrix: ‘intra wastes interaction’ approach

It is desirable to make effective use of solid wastes, as well as waste liquors, of the dye house generated from leather processing. The present study deals with the adsorption of Acid red 26 (Xylidine ponceau) dye using leather fibre waste (buffing dust) as substrate matrix by the means of ultrasound, magnetic stirring and conventional heating. The research examined the effect of various process parameters: ultrasonic power, concentration of dye, temperature and time. The dye uptake data have been fitted with Freundlich and Langmuir isotherms, indicating a useful dye adsorption process. A mechanism for dye adsorption in leather fibres has also been proposed. This study shows that it is possible to remove dyes from dye house effluent streams using leather waste fibres of buffing dust by means of ultrasound. Two different toxic wastes produced by the same industry can be effectively contained. This ‘Intra wastes interaction’ approach could reduce the burden of discarding wastes of other materials in the leather industry.     

N‐Arylsulfonyl Indolines as Retinoic Acid Receptor‐Related Orphan Receptor γ (RORγ) Agonists

The nuclear retinoic acid receptor‐related orphan receptor γ (RORγ; NR1F3) is a key regulator of inflammatory gene programs involved in T helper 17 (T_H17) cell proliferation. As such, synthetic small‐molecule repressors (inverse agonists) targeting RORγ have been extensively studied for their potential as therapeutic agents for various autoimmune diseases. Alternatively, enhancing T_H17 cell proliferation through activation (agonism) of RORγ may boost an immune response, thereby offering a potentially new approach in cancer immunotherapy. Herein we describe the development of N‐arylsulfonyl indolines as RORγ agonists. Structure–activity studies reveal a critical linker region in these molecules as the major determinant for agonism. Hydrogen/deuterium exchange coupled to mass spectrometry (HDX‐MS) analysis of RORγ–ligand complexes help rationalize the observed results.     

Mass transfer and biochemical reaction in enzyme membrane reactor systems—I. Single enzyme reactions

The effective use of an enzyme as a biological catalyst for process scale conversion is greatly enhanced by immobilizing the enzyme within the matrix of a membrane whose walls are permeable to the substrate and product. The enzyme is thus stabilized for reuse, but the apparent activity is reduced compared to that obtained with the free enzyme because of transport resistances in the bulk fluid near the membrane and within the membrane itself. To account for this reduction, solutions to the differential equations describing the mass transport-kinetic models can be obtained for certain important cases. The reaction is considered to be first-order and isothermal, and to occur in one of two modes of operation: fixed-bed or batch (limited volume). Irreversible and reversible reactions and plane sheet and spherical geometries of the membrane are considered. An example of the application of these solutions to actual data obtained with a laboratory scale immobilized enzyme reactor is presented.     

Directory-based composite routing and scheduling policies for dynamic multimedia environments

In this paper we present and evaluate algorithms to address combined path and server selection (CPSS) problems in highly dynamic multimedia environments. Our goal is to ensure effective utilization of network and server resources while tolerating imprecision in system state information. Components within the framework implement the optimized scheduling policies as well as collect/update the network and server parameters using a directory service. We present and analyze multiple policies to solve the CPSS problem. In addition, we study multiple techniques for updating the directory service with system state information. We further evaluate the performance of the CPSS policies under different update mechanisms and study the implications of the CPSS policies on directory service management.     

Optical constants of Bi2Te3 and Sb2Te3 measured using spectroscopic ellipsometry

In this work, we present the optical constants of bismuth telluride (Bi₂Te₃), and antimony telluride (Sb₂Te₃) determined using spectroscopic ellipsometry (SE). The spectral range of the optical constants is from 404 nm to 740 nm. Bi₂Te₃ and Sb₂Te₃ films with different thicknesses were grown by metalorganic chemical vapor deposition (MOCVD). Multiple sample analysis (MSA) technique was employed in order to eliminate the parameter correlation in the SE data analysis caused by the presence of the overalyer on top of Bi₂Te₃ and Sb₂Te₃ films. Optical constants and thicknesses for both Bi₂Te₃ and Sb₂Te₃ overlayers were also determined. Independent Bi₂Te₃ and Sb₂Te₃ samples were used to check the results obtained. In addition, SE analysis was performed on two Sb₂Te₃ samples after being etched in diluted NH₄OH solution in order to characterize the overlayer and confirm the reliability of the results.