Mechanical behavior of ferritic grade 3Cr12 stainless steel—Part 1: Experimental investigations

Ferritic stainless steels are corrosion resistant steels with a low and stable cost. Widely used in automotive applications, structural applications using ferritic stainless steels are only emerging mainly because ferritics are partially covered by structural standards due to a shortage of design data. Computer models are more and more used to support the developments of conventional design methods based on expensive full-scale tests or trial and errors methods. And for the modeling of metal forming processes as well as structural behavior of members, it is necessary to afford an accurate knowledge of the mechanical properties. In this paper, the experimental investigations made on the chromium based alloy 3Cr12 (1.4003) in order to characterize its mechanical behavior are presented. During the research, a classical uniaxial experimental equipment and a bi-axial experimental equipment designed by Flores (2005) [1] in the Structures Laboratory of the University of Liege have been used. The collection of tests performed included tensile tests, cyclic shear tests, simple shear tests and successive simple shear and plane-strain tests. The yield locus and the hardening models are presented and identified in a companion paper by the same author.     

Special Issue: Water Engineering and Management in a Changing Environment

The paper is the introduction to the special issue Water Engineering and Management in a Changing Environment which presents a set of the most innovative contributions at the EWRA Symposium, held in Catania, Italy on 2011.     

An environmental and thermodynamic analysis to select R22 alternative working fluids

R22, a hydrochlorofluorocarbon (HCFC), is used widely in the air-conditioning and refrigeration industry; however, it is being phased out along with other HCFCs, due to concerns about its impact on ozone depletion. In the EEC countries its production, commercialization and use will be forbidden before the end of 1999.

According to the AREP (R22 Alternative Refrigerants Evaluation Program) project, coordinated by the Air-conditioning and Refrigeration Institute (ARI) a group of substances has been pointed out as potential ozone-free R22 alternatives.

In this paper some working fluids, among those one considered by AREP, will be evaluated by means of a comparative thermodynamic analysis. Furthermore, particular interest will be paid to the environmental global impact joined to the substitution. To this aim, the Total Equivalent Warming Impact (TEWI) will be used as a tool to evaluate both direct and indirect contributions to the “greenhouse effect” linked to an operating vapour compression plant.     

A GC-EI-MS/MS Method for the Determination of 15 Polybrominated Diphenyl Ethers (PBDEs) in Fish and Shellfish Tissues

This paper describes the development and validation of an analytical method to determine 15 polybrominated diphenyl ethers (PBDEs) in fish and shellfish tissues with gas chromatography coupled to triple quadrupole mass spectrometry using electron impact source (GC-EI-MS/MS). A QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe)-like procedure was applied; the extract was cleaned up on an acidic Extrelut-NT3 column connected on top of a silica cartridge and further purified with gel permeation chromatography (GPC). The SIM acquisition proved to yield better results than traditional MRM approach for octa-, nona-, and deca-brominated congeners. The validation study was carried out in inter-laboratory conditions. The average recoveries were in the range 66–118%, with relative standard deviations generally lower than or equal to 22%. Quality assurance and quality control practices were thoroughly described and highlighted. These long and tedious practices are fundamental to obtain reliable quantitative data during food monitoring programs and, therefore, to support daily intake assessments. Finally, the procedure was applied to the analysis of marine fish samples collected in local markets. Mackerel and mullet were the most contaminated species.     

Synthesis of Indole Derivatives from 2-Alkynylanilines by Means of Gold Catalysis

The peculiar features of gold(III) and gold(I) species include exceptional carbophilicity and, at the same time, lone pair affinity. Such a combination offers many advantages for the development of more sustainable approaches to the synthesis of indole derivatives from readily available 2-alkynylanilines. This mini-review critically summarizes the literature reports in this field, with the aim to encourage further research activities in this promising area.     

Soil Moisture Measurements: Comparison of Instrumentation Performances

It has long been recognized that reliable, robust, and automated instrumentation for the measurement of soil moisture content can be extremely useful, if not essential, in hydrological, environmental, and agricultural applications. A number of automated techniques for point measurement of soil water content have been developed to operational level over the past few decades. While each of those techniques has been individually calibrated by the gravimetric method, typically under laboratory conditions, there have been few studies that made a direct comparison between the various techniques, particularly under field conditions. This paper compares ECH2O probes, EC-5 (both sensors based on capacitance measurements, developed by Decagon Devices) and time domain reflectometer sensors (CS616 Campbell Scientific Water Content Reflectometer), with gravimetric data and with each other, under field conditions. Data were collected during two field experiments characterized by different soils and a wide range of soil moistures, resulting from irrigation/drying cycle. Results show that all the tested probes give acceptable results after being calibrated in the field. The capacitive sensors can be used in each type of soil with the same calibration equation, independently from depth, with root mean square error (RMSE) ranging between 2.5 and 3.6%. Time Domain Reflectometry probes showed a dependence on depth but a lower RMSE (1.6%).     

Charge carrier transport anisotropy in ultrananocrystalline diamond films

The optoelectronic properties of ultrananocrystalline diamond films (UNCD) grown using N₂ = 0 and 5% in the deposition gas mixture, are investigated by transient photocurrent measurements under nanosecond light pulses, both in planar and sandwich contact arrangements.Independent of contact configuration and N₂% value, very similar characteristic times in the 6-7 ns range are detected in the nanosecond range, reflecting a homogeneous distribution of states responsible for such decay times. On a longer time scale, nitrogen addition appears to slow down carrier transport promoting trapping and detrapping processes responsible for single and two power law photocurrent decays in films deposited using N₂ = 5% for sandwich and planar contact arrangements, respectively. Such a result suggests a nitrogen induced transport anisotropy tentatively related to structural modifications occurring at relatively low N₂%.