Warsaw University of Technology

About: Warsaw University of Technology is a education organization based out in Warsaw, Poland. It is known for research contribution in the topics: Microstructure & Optical fiber. The organization has 14293 authors who have published 34362 publications receiving 492211 citations. The organization is also known as: Warsaw Polytechnic & Politechnika Warszawska.

Naïve Bayes classifier

Abstract: The Bayes Theorem gives us information of changes in probability given a particular situation. Bayes theorem act as a basic criteria for many machine learning algorithm and forms the basis of Naïve Bayes classifier. These kind of classifier work in linear time and are very scalable and adoptable. The conditional independence of features may result in wrong classification many times but the ease of use and adaptability of classifiers make these types of classifier as the widespread tool.

Density and Viscosity of Binary Mixtures of Thiocyanate Ionic Liquids + Water as a Function of Temperature.

Abstract: Densities and viscosities have been determined for binary mixtures of the ionic liquids (ILs) 1-butyl-3-methylimidazolium thiocyanate [BMIM][SCN], or 1-butyl-4-methylpyridinium thiocyanate [BMPy][SCN], or 1-butyl-1-methylpyrrolidinium thiocyanate [BMPYR][SCN], or 1-butyl-1-methylpiperidinium thiocyanate [BMPIP][SCN] with water over wide range of temperatures (298.15–348.15) K and ambient pressure. The thermal properties of [BMPy][SCN], i.e. glass transition temperature and the heat capacity at glass transition, have been measured using a differential scanning microcalorimetry, DSC. The decomposition of [BMPy][SCN] was detected. The density and viscosity correlations for these systems have been made using an empirical second-order polynomial and by the Vogel–Fulcher–Tammann equation, respectively. The concentration dependences have been described by polynomials. The excess molar volumes and deviations in viscosity have been calculated from the experimental values and were correlated by Redlich–Kister polynomial expansions. The variations of these parameters, with compositions of the mixtures and temperature, have been discussed in terms of molecular interactions. A qualitative analysis of the trend of properties with composition and temperature was performed. Further, the excess partial molar volumes, $V_{1}^{\mathrm{E}}$ and $V_{2}^{\mathrm{E}}$ , were calculated and discussed. The isobaric expansivities (coefficient of thermal expansion), α, and the excess isobaric expansivities, α E, were determined for four ILs and their mixtures with water. The results indicate that the interactions of thiocyanate ILs with water is not as strong as with alcohols, which is shown by the positive/slightly negative excess molar volumes in these binary systems.

Epoxy resin modified with soybean oil containing cyclic carbonate groups

Abstract: Carbonated soybean oil (CSO) containing five-membered cyclic carbonate groups has been obtained in the reaction of epoxidized soybean oil with carbon dioxide in the presence of KI activated by 18-crown-6 under 6 MPa CO2 pressure at 130°C. The CSO was used for modification of bisphenol-A based epoxy resin. The composition epoxide-cyclic carbonate was cured using polyamine hardeners by one-step and two-step procedures. All cured compositions were characterized for their thermal and mechanical properties and compared with the parent epoxy network. The optimal properties were obtained for compositions containing CSO and cured by one-step method when phase separation takes place. The mechanical properties were discussed in terms of morphology observed by SEM. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2904-2914, 2006

Solubility of 1-Alkyl-3-ethylimidazolium-Based Ionic Liquids in Water and 1-Octanol

Abstract: The liquid–liquid phase equilibria (LLE) of the following imidazolium ionic liquids (ILs), {1-ethyl-3-ethylimidazolium, or 1-butyl-3-ethylimidazolium, or 1-hexyl-3-ethylimidazolium bis{(trifluoromethyl)sylfonyl}imide [EEIM][Tf2N], or [BEIM][Tf2N], or [HEIM][Tf2N], + water or + 1-octanol}, and {1-butyl-3-ethylimidazolium hexafluorophosphate [BEIM][PF6] + water or + 1-octanol}, have been measured. The effect of anion type ([Tf2N]- compared to [PF6]-) and the effect of structural components of an ionic liquid including alkyl chain length on the cation and the ethyl substituent instead of methyl at the cation on the physical-chemical properties of the IL and on the phase behavior were studied. An upper critical solution temperature (UCST) was observed in every system. An increase in the alkyl chain length increases the mutual solubility with 1-octanol and partly with water. Ionic liquids with the ethyl substituent on the cation [HEIM][Tf2N] show higher solubility in 1-octanol in comparison with the methyl sub...