Physico-chemical properties of ethanol – Compilation of existing data

Physico-chemical properties of ethanol and aqueous solutions of ethanol are important for chemical engineering calculation, modelling and evaluation of processes during ethanol production and its use for food and non-food applications. The majority of these properties are possible to find in handbooks and tables as Yaws (1999): Chemical Properties Handbook; Miller and Yaws (1976): Correlation constants for liquids; Lide (2007–2008): CRC Handbook of Chemistry and Physics; Hole?ek (2007): Chemical-engineering tables; Critical Data Tables and other literature. Some of them are also accessible online. The goal of this paper is to present the formulas and developed algorithms for calculation of extended properties of ethanol collected from literature. Extended properties include density, vapor pressure, surface tension, viscosity, molar and specific heat capacity, enthalpy of vaporization, thermal conductivity and static relative permittivity (dielectric constant) of ethanol.     

Behaviour of an optically trapped probe approaching a dielectric interface

Abstract

The way in which reflection of the trapping beam from a dielectric interface influences the distance of the trapped sphere from the beam waist is studied theoretically and experimentally. The reflected wave interferes with the incident wave and they create a standing-wave component in the total axial intensity distribution. This component then modulates the trapping potential and creates several possible equilibrium positions for the trapped sphere. When the beam waist approaches the surface, the potential profile changes, which consequently causes jumps of the trapped probe from its current location to a deeper potential well. We suggested theoretically and proved experimentally that the magnitude of these unwanted jumps between the neighbouring equilibrium positions can be decreased by a suitable size of the sphere.     

Some Properties of Nickel-Cobalt Alloys Electrodeposited from Sulphosalicylate Solutions

An uncommon electrolyte, based on sulphosalicylic acid, was used for nickel-cobalt deposition. Some mechanical properties (internal stress and microhardness) and structural properties of the deposits have been presented. High microhardness (nearly 800 HM) with simultaneous low internal stress (about 50 MPa) can be reached.     

Synthesis and magnetorheological characteristics of ribbon‐like,polypyrrole‐coated carbonyl iron suspensions under oscillatory shear

One of the crucial problems of classical magnetorheological (MR) fluids is their high rate of sedimentation. This disadvantage may be substantially eliminated using core‐shell particles. The aim of this study is to prepare spherical carbonyl iron (CI) particles coated with conducing polymer polypyrrole (PPy) with ribbon‐like morphology. Scanning electron microscopy proved the formation of the ribbon‐like layer onto CI particles while Fourier transform infrared spectroscopy confirmed the chemical structure of PPy. The magnetic properties observed via vibrating sample magnetometer showed decreased magnetization saturation of core‐shell‐structured particles due to the existence of non‐magnetic surface layer. MR measurements performed under oscillatory shear flow as a function of the applied magnetic flux density, temperature, and particle concentration showed that core‐shell particle‐based MR suspension exhibits sufficient MR performance for practical applications. Moreover, the suspension stability is promoted significantly when core‐shell particles are used as a dispersed phase. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

A Novel Three-Dimensional Hydrogel-Based Microarray Platform

Three dimensional (3D) microarrays utilizing hydrogel matrixes are becoming increasingly attractive as a desired format for bio-analysis. These materials offer significant advantages as a scaffolding for capture agents over more conventional two dimensional (2D) printed formats in both captures per site and the ability to provide an environment more closely resembling that of a free solution. Biocept has developed a flexible three dimensional polyethylene glycol (PEG) polymer based platform suitable for a variety of biological assays. This novel approach is simple, biocompatible and provides a high degree of reproducibility and very low variability in the final array.     

The hot rectus abdominis muscle sign

We report a 2.5-year-old child who presented with an acute abdomen caused by the perforation of a sewing pin through her appendix that had started to penetrate the wall of the bladder.     

Enabling differentiated services using generalized power control model in optical networks

This paper considers a generalized framework to study OSNR optimization-based end-to-end link level power control problems in optical networks. We combine favorable features of game-theoretical approach and central cost approach to allow different service groups within the network. We develop solutions concepts for both cases of empty and nonempty feasible sets. In addition, we derive and prove the convergence of a distributed iterative algorithm for different classes of users. In the end, we use numerical examples to illustrate the novel framework.     

Electrodeposition of nanocrystalline chromium-carbon alloys from electrolyte based on trivalent chromium sulfate using pulsed current

The effect of the parameters of pulsed electrolysis on the current efficiency, nanocrystal size, composition, hardness, friction coefficient, and wear resistance of nanocrystalline Cr-C coatings obtained from electrolyte based on Cr(III) sulfate containing carbamide and formic acid is studied. It is shown that coatings contain ∼9 wt % of carbon; the current density and pulse ratio produce practically no effect on their composition. It is found that a maximum appears on the dependence of current efficiency on pulse ratio in the case of the pulse ratio of ∼1.05–1.1. Thereby, current efficiency greatly exceeds the value implemented in the steady-state current mode. It is shown that, if the microhardness of Cr-C deposits obtained at constant current is close to 850–900 HV, the microhardness may increase to ∼1200−300 HV when pulsed electrolysis is used in certain modes. It is found that application of pulsed electrolysis allows a significant decrease in the friction coefficient of chromium-carbon coating (steel counterbody) both under the dry friction conditions and in the case of boundary lubrication and also results in an increase in the deposit wear resistance.