A morphological study on direct polymer cast micro-textured hydrophobic surfaces

The surface microstructures that contribute to the lotus leaf's superhydrophobicity are replicated onto a polymer surface using a two-stage (negative-positive) direct casting method and the replicates' surface morphology is investigated in this study. Vinyl polysiloxane (VPS), polydimethylsiloxane (PDMS) and polymethylmethacrylate (PMMA) are used for the replication and the replicates obtained are investigated using confocal microscopy, scanning electron microscopy (SEM), and contact angle measurements. Geometric texture parameters such as peak height, peak/valley base width and inter-spacing between adjacent peak/valleys are measured for the lotus leaf and its replicates. Of the six combinations of positive and negative replicates attempted, VPS-PMMA and PDMS-PMMA replicates display shorter peak heights and larger base widths. These replicates have contact angles of 132.1° and 129.2° respectively, which are closest to the contact angle of the lotus leaf, 152.9°. Statistical two sample t-test revealed that VPS-PMMA's surface morphological parameters are closest to that of the lotus leaf. Also, theoretical calculations, based on two different methods from literature, using the measured geometric texture parameters show that polymer replicates satisfy criteria for a stable Cassie-Baxter wetting regime.     

Solution to economic dispatch problem with valve-point loading effect by using catfish PSO algorithm

This paper proposes application of a catfish particle swarm optimization (PSO) algorithm to economic dispatch (ED) problems. The ED problems considered in this paper include valve-point loading effect, power balance constraints, and generator limits. The conventional PSO and catfish PSO algorithms are applied to three different test systems and the solutions obtained are compared with each other and with those reported in literature. The comparison of solutions shows that catfish PSO outperforms the conventional PSO and other methods in terms of solution quality though there is a slight increase in computational time.     

Simulation Studies on Buoyancy-Aided Conjugate Mixed Convection With Radiation From a Vertical Plate With Multiple Nonidentical Heat Sources

This paper documents certain salient results of the simulation studies performed on conjugate mixed convection with surface radiation from a vertical electronic board equipped with multiple nonidentical flush-mounted discrete heat sources. Air that is assumed to be radiatively transparent with constant thermophysical properties subjected to the Boussinesq approximation is considered to be the cooling agent. The governing fluid flow and heat transfer equations without the boundary-layer approximations are initially transformed into vorticity-stream function form and are later appropriately normalized. The resulting equations, along with pertinent boundary conditions, are subsequently solved using a finite-volume-based finite-difference method coupled with Gauss–Seidel iterative technique. An extended computational domain has been used to capture the fluid flow and heat transfer adequately employing optimum combination of finer and coarser grids. A computer code is specifically written for the job. Effects of modified Richardson number, surface emissivity, and thermal conductivity on local temperature distribution, peak board temperature, and contributions of mixed convection and radiation in heat dissipation have been clearly elucidated. Two correlations that help in calculation of maximum and average nondimensional plate temperatures have also been developed.     

Aflatoxins and food pathogens: impact of biologically active aflatoxins and their control strategies

Globally disease outbreaks as a result of the consumption of contaminated food and feedstuffs are a regular primary problem. The foremost elements contributing to contamination are microorganisms, particularly fungi, which produce low‐molecular weight secondary metabolites, with demonstrated toxic properties that are referred to as mycotoxins. Aflatoxins contaminate agricultural commodities and may cause sickness or fatality in humans and animals. Moreover, poor conditions of storage and a deficiency in regulatory measures in food quality control aggravate the main issue. For that reason, mycotoxin‐related illness of nutrition represents a major health hazard for local populations. Government policies should make regulations aiming to avoid the entry of aflatoxins into food stuffs. For consumer safety, control and management strategies should be developed and implemented by regulatory authorities. There is the need for attention from farmers, scientists, government and collaborative minds throughout the country to ensure aflatoxin‐free food. The present review is informative not only for health‐conscious consumers, but also for relevant authorities with respect to paving the way for future research aiming to fill the existing gaps in our knowledge with regard to mycotoxins and food security. © 2016 Society of Chemical Industry     

Opportunities and challenges in setting up solar photo voltaic based micro grids for electrification in rural areas of India

Rural area electrification in developing countries helps to improve the quality of life of the people. It increases productivity and supports education. It also discourages people from migrating towards urban areas. In India about 70% of the population lives in rural area, hence it is necessary to electrify these villages to achieve inclusive economic growth. Transmission and distribution of power to this less densely populated areas which are located far away from the power generating stations is the major reason for not able to achieve 100% electrification in the country. Hence it is necessary to find out an energy source which can be decentralized to supply power to these hamlets. As India is blessed with solar energy which is omnipresent in almost all parts of the country, micro grid system which uses solar photo voltaic panels seems as the finest option. The solar photo voltaic system converts light energy into direct current power using photovoltaic effect. Battery is used to store the extra power generated during the day and used during nights. Inverters and power conditioning devices are used to convert direct current power generated by solar photo voltaic systems to alternative current, which is supplied to the load using power distribution network which adds to system cost. At present the capital cost and the land requirement for this system is higher than all other renewable energy power generation system. But it has very less operation and maintenance cost which makes it superior to other system. Moreover additional modules can be added to it when the power demand increases. This paper says about how rural area electrification can be achieved in India by solar photo voltaic system micro grid system and the challenges which has to be over come during implementation.     

Cumulative residual entropy: a new measure of information

In this paper, we use the cumulative distribution of a random variable to define its information content and thereby develop an alternative measure of uncertainty that extends Shannon entropy to random variables with continuous distributions. We call this measure cumulative residual entropy (CRE). The salient features of CRE are as follows: 1) it is more general than the Shannon entropy in that its definition is valid in the continuous and discrete domains, 2) it possesses more general mathematical properties than the Shannon entropy, and 3) it can be easily computed from sample data and these computations asymptotically converge to the true values. The properties of CRE and a precise formula relating CRE and Shannon entropy are given in the paper. Finally, we present some applications of CRE to reliability engineering and computer vision.     

Immune response to phi X 174 in man. 5. Primary and secondary antibody production in primary biliary cirrhosis

In primary biliary cirrhosis, the primary immune response to the bacteriophage phi X 174 is normal but the secondary response is significantly reduced. The reduction is primarily of IgG antibody, while IgM is proportionately less affected. These changes may be the result of a reduction in helper T lymphocyte function and may contribute to the increase in the ratio of serum concentration of IgM to IgG.