Behavior of square and circular columns strengthened with aramidic or carbon fibers

The confinement of reinforced concrete (RC) columns with transverse reinforcement has been extensively studied and it is known that the response of concrete cylinders subjected to equivalent levels of pressure depends on how that lateral pressure is transmitted, and not on its magnitude alone. When confinement is, additionally to that given by steel stirrups, provided by external jackets of fiber reinforced polymers (FRP) the complexity and the scarcity of experimental data increase and tests to gain insight into the structural behavior and consequent design procedures are still required. The present study reports tests performed on axially loaded RC columns, with and without jackets. The FRP tested were made either of carbon fibers reinforced polymers (CFRP) or aramidic (AFRP) wraps and the geometry of the specimens included square and circular cross-sections. Comparison of gains of axial strength and ductility are presented and aspects of the variation of the lateral pressure and rupture of FRP jackets are examined.     

The ITU-T Software Tool Library

The advancement of speech coding technology has led to new and improved standards. The Telecommunication Standardization Sector of the International Telecommunication Union (ITU-T) has been a leader in developing speech coding standards for telecommunications applications. To increase the efficiency of the coding standard selection process, a group called User's Group on Software Tools (UGST) was established in 1990 to produce a framework of speech coding-related software tools that would allow a common ground for activities across different organizations. Over the years, this group produced a high-quality software tool library (STL), which has been used in the definition of ITU and non-ITU standards, such as G.723.1, G.729, half-rate and enhanced full-rate GSM, among others. However, despite its usefulness, the ITU-T STL is largely unknown outside the telecommunications standards community. This paper introduces the ITU-T STL concepts and functionalities to the wider communications community.     

The comparison of the corrosion resistance of advanced ferromagnetic stainless steels by Mott–Schottky approach

Ferromagnetic stainless steels (SSs) have been investigated as potential candidates for dental prosthesis applications in replacement of magnetic attachments made of noble and expensive alloys. In order to be used as biomaterials, their corrosion resistance has to be appropriate. The corrosion resistance of passive materials is related to the characteristics of the passive film formed and their properties might be investigated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization curves, and Mott–Schottky approach. The corrosion resistance and the capacitance of the passive films formed on PM2000, DIN 1.4575, and 17‐4 PH advanced SSs during 2 days of immersion in a phosphate buffered saline solution (PBS), at 25 °C and pH 7.0 were studied by electrochemical techniques. A commercial alloy Dyna EFM was also analyzed for comparison reasons. The results showed that films on tested materials behave as both n‐type and p‐type semiconductors and the PM2000 presented the highest corrosion resistance among all of them.     

Biohydrometallurgical/UV production of ferrous sulphate heptahydrate crystals from pyrite present in coal tailings

The objective of this work was to develop a biohydrometallurgical/UV radiation route to produce ferrous sulphate heptahydrate (melanterite) from the pyrite present in coal tailings. The experimental work was carried out with a pyrite concentrate obtained from gravimetric processing of coal tailing. At laboratory scale it was performed the oxidation of pyrite in an aqueous medium in packed bed leaching columns in an oxidising environment with the presence of acidophilic bacteria (Acidithiobacillus ferrooxidans). The recirculation of the liquor allowed obtaining an iron-rich extract. The conversion of Fe³⁺ to Fe²⁺ was performed using ultraviolet irradiation (UV). Finally, the solution was evaporated allowing the formation of iron sulphate crystals. The results demonstrated that it is possible to produce high purity ferrous sulphate heptahydrate crystals using coal tailings as raw material.     

Innovation in traditional food products in Europe: Do sector innovation activities match consumers’ acceptance?

Traditional food products are subject to an increased interest in Europe. Innovations, though controversial in the context of traditional food, are essential to maximally cope with this opportunity. So far, only few studies have concentrated on innovation in the traditional food sector. In this paper sector and consumer data are combined in order to validate to what extent innovations in the traditional food sector match with consumers’ acceptance. Sector innovations were explored through 270 interviews, covering 90 traditional food chains in three European countries (Belgium, Italy and Hungary). Consumers’ innovation acceptance was investigated using a quantitative survey approach with 2429 respondents in Belgium, Italy and Poland. In general, both the sector and the consumers were open towards innovations in traditional food products. In addition, the innovation activities of the sector were matching well with the innovations accepted by consumers. Throughout, preserving the traditional character of the food was stressed as a prerequisite for innovations in traditional food products.     

Variable-order fractional derivatives and their numerical approximations

This paper addresses the different possible definitions of variable-order derivatives and their numerical approximations; both approximations based upon the definitions and approximations consisting of non-linear transfer functions (in particular combining existing approximations of constant-order fractional derivatives, such as the Crone approximation, with fuzzy logic) are considered. There are different possible configurations, implementing variable-order fractional derivatives both with and without memory of past values of the time-dependent differentiation order.     

Natural Lignocellulosic Fibers as Engineering Materials—An Overview

Recent investigations on the tensile properties of natural cellulose-based fibers revealed an increasing potential as engineering materials. This is particularly the case of very thin fibers of some species such as sisal, ramie, and curaua. However, several other commonly used fibers such as flax, jute, hemp, coir, cotton, and bamboo as well as less known bagasse, piassava, sponge gourde, and buriti display tensile properties that could qualify them as engineering materials. An overview of the strength limits attained by these fibers is presented. Based on a tensile strength vs density chart, it is shown that natural fibers stand out as a relevant class of engineering materials.     

Dielectric characterization of alcoholic beverages and solutions of ethanol in water under microwave radiation in the 1–20 GHz range

We measured the dielectric permittivity of several solutions of ethyl alcohol in water and observed that their spectra follow the Debye model. The parameters used to adjust the Debye model according to the alcohol concentration in a solution follow a linear law. We tested the resulting model with various alcoholic beverages and found that we can obtain the concentration of alcoholic solutions using our model.