Biopolishing and cyclodextrin derivative grafting on cellulosic fabric for incorporation of antibacterial agent thymol

Antibacterial textiles were developed and replenished with innovative technologies for durable activity of the antibacterial agent. Inclusion complex formation property of cyclodextrin and their derivatives were utilized for better durability of antibacterial, insect repellent and cosmetic textiles. In this work cellulase treatment process was performed on organic cotton to improve the grafting yield of the cyclodextrin derivative monochlorotriazinyl-β-cyclodextrin (MCT-β-CD). Thymol, an antibacterial compound was incorporated into MCT-β-CD grafted organic cotton to bring enhanced antibacterial property with improved durability. UV–visible and Fourier transform infrared analysis confirmed the incorporation of thymol into cyclodextrin. Scanning electron microscope and energy dispersive X-ray analysis confirmed the morphological and structural changes occurred on the fabric. High performance liquid chromatographic analysis (HPLC) quantified the thymol content on the fabric. Agar diffusion test was performed on fabrics against Staphylococcus aureus and Escherichia coli and their durability to washing cycles was also investigated. Biopolishing, a cellulase enzyme treatment has remarkably raised the grafting yield of MCT-β-CD on fabric. The inclusion of thymol on biopolished MCT-β-CD grafted fabric facilitated durability to the antibacterial property of fabric upon repeated washing process.     

Effect of Mg doping on the properties of combustion synthesized LiCoO<Subscript>2</Subscript> powders

The LiCo_1-xMg_xO₂ (x = 0–0.1) cathode materials for rechargeable lithium ion batteries were synthesized by starch assisted combustion route method. The structural characterization was carried out by X-ray powder diffraction and Laser Raman Spectroscopy. The sample exhibited a well-defined rhombohedral structure and the lattice parameters varied with the increasing magnesium contents. Surface morphology of the synthesized materials was determined by Scanning electron microscope. The cathode materials consist of highly-ordered single crystalline particles with spherical shape. The electrical resistivities of the samples were studied by Hall Effect. Electrical resistivities decrease with increase in magnesium content. Electrochemical properties were characterized by the assembled test cells using Galvanostatic discharge studies that were carried out at a current rate of 0.1 C. Magnesium doped LiCo_0.95Mg_0.05O₂ show improved structural stability, high reversible capacity and excellent electrochemical performance.     

Simple and Highly Convenient Two‐Step Practical Procedure for the Synthesis of Optically Pure Methyl D‐erythro‐2,3‐Dihydroxybutanoate

A synthesis of enantiopure methyl D ‐erythro‐2,3‐dihydroxybutanoate has been realized using two simple and consecutive reactions on D ‐erythronolactone as the starting material. The two reactions are lactone ring opening with hydrobromic acid in methanol and subsequent reductive debromination.     

Computers in law — Some questions

The use of the computer in the legal arena has seen a rapid increase over the last decade ranging from the simple level where it is used to gain access to information to the complex level where it is used for diagnostic and decision making purposes. This second use of technology makes certain assumptions at the theoretical level regarding the nature of law and legal reasoning. This paper outlines in brief the jurisprudential assumptions made and the resulting questions raised as a consequence of the possiblity of ascribing legal functions to intelligent computer systems.     

Thermal management using synthetic jet ejectors

The utility of a synthetic jet ejector for thermal management at low flow rates is discussed. A synthetic jet ejector typically consists of a primary "zero-mass-flux" unsteady jet driving a secondary airflow through a low profile, high aspect ratio channel. A simple configuration of a nominally two-dimensional jet ejector in a rectangular channel is used to investigate the effects of channel width on the induced flow rate, power dissipated, heat transfer coefficient and thermal efficiency. An active heat sink for high power microprocessors is developed using the jet ejector concept and its performance is discussed.     

Mass transfer with chemical reaction in liquid foam reactors

Mass transfer studies were conducted in a stable liquid foam reactor under various operating conditions to evaluate gas holdup, effective interfacial area, liquid-phase mass transfer coefficient and a modified interfacial mass transfer coefficient to include the surface-active agents employed. Gas holdup and effective interfacial area were evaluated experimentally. The interfacial mass transfer coefficient was evaluated semitheoretically, by considering the interfacial region as a separate phase and using the experimental data developed for mass transfer accompanied by a fast first-order chemical reaction. The liquid-phase mass transfer coefficient was also evaluated semitheoretically, using Danckwert's theory for the liquid phase and the experimental data on mass transfer accompanied by a slow pseudofirst-order chemical reaction. An experimental unit was set up to provide a stable flowing foam column, simulating the foam reactor. Mass transfer rates were studied for superfacial gas velocities in the range from 1.5 × 10⁻² m/s to 5 × 10⁻² m/s, giving gas residence times in the range from 20 to 55 seconds. A cationic and nonionic surface-active agent and three different wire mesh sizes, giving bubble size distributions in the range from 2.2 to 5.4 mm Sauter mean diameters, were employed. It is observed that gas holdup is insensitive to the type of surface-active agent; it is however, dependent on wire mesh size and gas velocity. The bubble diameter and, hence, the interfacial area are found to be insensitive to gas velocity in the range studied; they are, however, strong functions of wire mesh size. The liquid-phase mass transfer coefficient increases with increase in gas velocity. The surface-active agent introduces additional resistance to mass transfer in both reaction cases, this being the controlling one in the case of the fast reaction. A comparison with conventional packed bed contactors indicates the mass transfer rates to be about 8 times lower for the foam reactor, for the fast reaction case; for slow reactions, the foam reactor has mass transfer rates approximately 2-4 times higher than those for conventional packed bed contactors.     

An evaluation of the applicability of 4D CAD on construction projects

4D CAD models that integrate physical 3D elements with time, have been used to visualize construction processes in several projects worldwide. 4D models have been used and have been shown to have benefits over processes that span the entire lifecycle of a project such as collaboration with stakeholders, making design decisions, assessing project constructability, identifying spatial conflicts in construction and so on. Despite these benefits, several organizational and project-specific barriers have hindered the widespread adoption of 4D CAD. In order to reconcile the theoretical benefits of 4D models with the practical difficulties faced in implementation, there is an urgent need to explore the implementation of 4D models on construction sites as well as the perceptions of intended users/beneficiaries towards this implementation. This paper aims to address this need and contribute to our understanding of how 4D models must be introduced, positioned and implemented on construction sites, so as to maximize both their acceptability and their usefulness. We describe two 4D models of infrastructure projects and two 4D models of commercial projects that have been built and implemented. Through a process of structured and unstructured interviewing the paper gauges the response of project participants across various organizational levels on each of these projects as to the usefulness of 4D in project planning and control. Through qualitative and statistical analysis of the data we establish that 4D CAD is likely to be most beneficial in the project shaping or planning stage and in the construction stage. In the project shaping stage, 4D CAD is likely to be particularly useful in communicating construction plans and processes to clients, while during the construction phase, 4D CAD is likely to be particularly useful in comparing the constructability of work methods visually in order to detect conflicts or clashes, and as a visual tool for contractors, clients, subcontractors and vendors to review and plan project progress. Further, upper management and site workers are more likely to use and derive benefits from the visualization of processes using 4D given their lack of site related knowledge or skills, while construction professionals who are more construction-savvy are more likely to appreciate and benefit from the analytical and planning aids that 4D simulations provide during the construction phase. However, it is likely that despite these benefits 4D CAD models might not diffuse through the construction industry unless 4D modelling and analysis is integrated into existing project planning approaches. The paper concludes with a brief discussion on future 4D software development that seeks to bring about such integration and leverages the benefits of 4D CAD to bring about improved operational efficiencies on construction sites.