Distribution of non-sinusoidal currents in parallel conductors used in three-phase four-wire networks

This paper presents an analysis of the distribution of non-sinusoidal currents among parallel-connected cables in low-voltage, three-phase TN–S systems. The cables are assumed to be laid on metallic cable trays in free space, which means that the influence of earth is neglected. An iterative algorithm is developed which can accurately estimate the distribution of line and neutral currents among parallel-connected cables at various harmonic frequencies provided that the impedance matrix of the whole cable system is given.     

Hydrometallurgical Treatment of Steelmaking Electric Arc Furnace Dusts (EAFD)

The aim of the current research study was the development of a hydrometallurgical process for the recovery of metals from electric arc furnace dust. The behaviors of zinc, cadmium, iron, and lead in sulfuric acid were investigated. The recovery of the zinc (from zinc oxide) and cadmium is possible with a relatively high yield, as iron and lead remain in the solid residue after two stages of leaching at room temperature. In a third stage, zinc recovery from the zinc ferrite (in the leached residue) was carried out by pressure leaching. Under the optimum conditions of treatment and after three stages of processing, the total extractions of zinc and cadmium were 99 and 94 pct, respectively. Lead and the main part of iron remain in the residue. The proposed process also resulted in the reduction of the initial residue mass by 30 pct.     

Validation of a Loop-Mediated Amplification/ISO 6579-Based Method for Analysing Soya Meal for the Presence of <Emphasis Type="Italic">Salmonella enterica</Emphasis>

An alternative method for detection of Salmonella spp. in animal feed, based on the use of loop-mediated amplification (LAMP) in conjunction with a standard culturing procedure, was compared with the standard ISO 6579 as reference method, using soya meal as the test matrix. In the method comparison study, the sensitivities for both the alternative and reference methods were 100 %. The relative level of detection was 1.000. Tested against 100 Salmonella and 30 non-Salmonella strains, the LAMP-based method was 99 % inclusive and 100 % exclusive. The interlaboratory trial involved ten laboratories from eight European countries, testing eight samples at three contamination levels: 0 cfu/100 g, 1–5 cfu/100 g and 14–68 cfu/100 g. The trial specificity, or percentage correct identification of uncontaminated samples, was 96.3 % for both the reference methods and the LAMP/ISO 6579 alternative method, thus demonstrating its suitability for adoption as a procedure for rapid identification of Salmonella uncontaminated soya meal.     

The role of hydrogen in hydrogen embrittlement fracture of lath martensitic steel

The microstructure associated with the hydrogen-induced features “flat” and “quasi-cleavage” on the fracture surface of a lath martensitic steel has been visualized in a transmission electron microscope by using focused-ion beam machining to extract samples perpendicular to the fracture surface. Beneath both hydrogen-induced fracture surfaces there is direct evidence, in the form of intense slip bands and destruction of lath boundaries, for significant plasticity. These observations are considered in terms of the fundamental hydrogen embrittlement mechanisms, and the conclusion is reached that the failure is driven by a hydrogen-enhanced and plasticity-mediated decohesion mechanism.     

Continuous electromagnetic radiation monitoring in the environment: analysis of the results in Greece

Non-ionising radiation-monitoring networks were initiated as a result of the public concerns about the potential health effects from telecommunication emissions. In the present study, the data acquired from such networks in Greece are used to assess the changes in the outdoor electromagnetic environment with respect to location and time. The study shows that there is a statistically significant difference between the urban (median electric field: 1.1 V m(-1)) and the rural (median electric field: 0.3 V m(-1)) installations of monitoring units and also shows that there is a median diurnal variation (daily maximum to minimum) of 20.2 and 33.8 % for the broadcasting and mobile telecommunication emissions, respectively. Moreover, there is a difference in the electric field between daytime and night, but not between morning and afternoon. The results are in line with previously published data from spot measurements, monitoring networks and personal exposimeter studies performed in several European countries.     

Rejection of unknown periodic disturbances for continuous‐time MIMO systems with dynamic uncertainties

Rejection of unknown periodic disturbances in multi‐channel systems has several industrial applications that include aerospace, consumer electronics, and many other industries. This paper presents a design and analysis of an output‐feedback robust adaptive controller for multi‐input multi‐output continuous‐time systems in the presence of modeling errors and broadband output noise. The trade‐off between robust stability and performance improvement as well as practical design considerations for performance improvements are presented. It is demonstrated that proper shaping of the open‐loop plant singular values as well as over‐parameterizing the controller parametric model can significantly improve performance. Numerical simulations are performed to demonstrate the effectiveness of the proposed scheme. Copyright © 2016 John Wiley & Sons, Ltd.     

Loss of heterozygosity on the long arm of human chromosome 7 in sporadic renal cell carcinomas

Cytogenetic and molecular analysis of DNA sequences with highly polymorphic microsatellite markers have implicated allele loss in several chromosomal regions including 3p, 6p, 6q, 8p, 9p, 9q, 11p and 14q in the pathogenesis of sporadic renal cell carcinomas (RCCs). Deletions involving the long arm of chromosome 7 have not been described in RCCs although they have been seen in several other tumor types. However, there have been no detailed analysis of loss of heterozygosity (LOH) of 7q sequences in sporadic RCCs. We therefore studied LOH for DNA sequences on 7q with 10 highly polymorphic markers in 92 matched normal/tumor samples representing sporadic RCCs including papillary, nonpapillary, and oncocytomas in order to determine whether allelic loss could be detected in a tumor type with no visible 7q rearrangements at the cytogenetic level. We found chromosome 7q allele loss in 59 of 92 cases (64%) involving one, two, or more microsatellite markers. The most common allele loss included loci D7S522 (24%) and D7S649 (30%) at 7q31.1-31.2, a region that contains one of the common fragile sites, FRA7G. By comparative multiplex PCR analysis, we detected a homozygous deletion of one marker in the 7q 31.1-31.2 region in one tumor, RC21. These results support the idea that a tumor suppressor gene in 7q31 is involved in the pathogenesis of sporadic renal cell carcinomas.     

Optimal and control of hybrid multirate systems

The problem of using a synchronous multirate digital controller for a continuous-time plant is considered. The performance objectives considered are the H^∞ and the H² norms of the periodically time-varying continuous-time input-output behavior of the closed loop system. A continuous-time lifting technique is used to solve these hybrid sampled-data problems. This approach yields equivalent purely discrete-time problems while preserving the multirate causality of the systems. The later problems can then be solved using known techniques.