Stearidonic Acid Increases the Red Blood Cell and Heart Eicosapentaenoic Acid Content in Dogs

Plant sources of omega-3 fatty acids (FA) are needed that can materially raise tissue levels of long-chain omega-3 FA [i.e., eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 20:6n-3)]. Stearidonic acid (SDA; 18:4n-3) is the delta-6 desaturase product of alpha-linolenic acid (ALA; 18:3n-3), and when fed to humans, increases red blood cell (RBC) content of EPA to a greater extent than does ALA. This study was undertaken to determine the dose-dependence and time course of the increase in the EPA and DHA content of the heart and RBC in dogs. Adult male Beagles were fed 21, 64, or 193 mg/kg of SDA in in their food daily for up to 12 weeks. Positive and negative controls were given EPA (43 mg/kg) or high oleic acid sunflower oil, respectively. The baseline EPA content of RBC was 0.38 ± 0.03% which increased (P < 0.01) in a dose-dependent manner, with the high dose of SDA and EPA achieving levels of 1.33 ± 0.26 and 1.55. ± 0.28%, respectively. In the heart, the content of EPA rose from 0.06 ± 0.01 to 1.24 ± 0.22% in the EPA group and to 0.81 ± 0.32% in the high SDA group (both P < 0.01). In both tissues, DHA did not change. Compared to dietary EPA, SDA was 20–23% as efficient in raising tissue EPA levels. In conclusion, SDA supplementation increased the EPA content of RBC and heart and may have utility as a plant-based source of omega-3 FA.     

Probabilistic seismic damage assessment of reinforced concrete buildings considering directionality effects

Most of buildings and structures are usually projected according to two main axes. However, the geographical position of these buildings varies randomly. Such random distributions of the azimuthal positions of structures, in most of the cities, generally, are not accounted for when assessing their seismic risk; certainly, the direction of the seismic loads is another highly random variable. Moreover, an additional important source of uncertainty is related to the structural response, mainly due to the random character of the mechanical properties. There is a consensus that uncertainties must be considered for adequately assessing the seismic risk of structures, but these directionality effects have not been deeply explored so far. In this article, the influence of the high uncertainty involved in these input variables on the expected seismic damage is analysed. Thus, an actual earthquake, which affected the southern part of Spain, is studied. Notably, damages on a group of affected buildings, located close to the epicentre, are analysed and discussed in detail. The results show that the influence of the random azimuthal position of structures is an important source of uncertainty and that it should be taken into account when estimating the expected seismic risk in urban areas.     

Investigation on mining subsidence over Appin–West Cliff Colliery using time-series SAR interferometry

Advanced Time Series InSAR (ATS-InSAR) generally refers to those TS-InSAR methods with an external distributed scatterer selection module, e.g. SqueeSAR?, and GEOS-ATSA (Advanced Time-Series Analysis). It is being known as a very efficient tool for monitoring ground deformation over suburban or non-urban regions with great success. However, research conducted using C-band Envisat-based ATS-InSAR failed to produce reasonable outcome within Appin Colliery primarily due to the underground mining effect, which is located in the southeastern corner of the Southern Coalfield, New South Wales, Australia; thus, the general underground mining pattern cannot be formed. This work presents a modified ATS-InSAR method for mapping the ground deformation over underground mining region. More specifically, in order to achieve the best outcome, a modified measurement scatterer (MS) pixel selection method is introduced by including less reliable MS pixels through an Inverse Distance Weighted-based integration method. In addition, the proposed method is also applied to C-band Sentinel-1 image stacks for testing purpose, and the final result proved to be efficient to offer sufficient information to the mining industry and government for risk management purpose.     

How verified (or tested) is my code? Falsification-driven verification and testing

Formal verification has advanced to the point that developers can verify the correctness of small, critical modules. Unfortunately, despite considerable efforts, determining if a “verification” verifies what the author intends is still difficult. Previous approaches are difficult to understand and often limited in applicability. Developers need verification coverage in terms of the software they are verifying, not model checking diagnostics. We propose a methodology to allow developers to determine (and correct) what it is that they have verified, and tools to support that methodology. Our basic approach is based on a novel variation of mutation analysis and the idea of verification driven by falsification. We use the CBMC model checker to show that this approach is applicable not only to simple data structures and sorting routines, and verification of a routine in Mozilla’s JavaScript engine, but to understanding an ongoing effort to verify the Linux kernel read-copy-update mechanism. Moreover, we show that despite the probabilistic nature of random testing and the tendency to incompleteness of testing as opposed to verification, the same techniques, with suitable modifications, apply to automated test generation as well as to formal verification. In essence, it is the number of surviving mutants that drives the scalability of our methods, not the underlying method for detecting faults in a program. From the point of view of a Popperian analysis where an unkilled mutant is a weakness (in terms of its falsifiability) in a “scientific theory” of program behavior, it is only the number of weaknesses to be examined by a user that is important.     

From experimental data,the mechanics relationships describing the behaviour of four different low alloyed steel powders during uniaxial cold compaction

This work aims at determining the constitutive model of four commercial water atomised low alloyed steel powders during cold compaction. Single-action experiments were performed, obtaining cylindrical specimens with different H/D ratios. The distribution of axial and radial stresses was investigated, and the relationships describing both the radial stress transmission coefficient and the flow stress as functions of the relative density were determined. The radial stress transmission coefficient also confirmed the hypothesised value of Poisson’s coefficient. The friction coefficient between the powder column and the die wall was determined, also highlighting the influence of the H/D ratio. Measuring the axial and radial strains due to spring-back, the axial and radial elastic moduli were determined, as functions of the relative density. The results obtained for the four materials were compared, also highlighting both differences and similarities.     

Structural and optical characterization of CuInSe2 films deposited by hot wall vacuum evaporation method

Copper indium diselenide (CuInSe₂) compound was prepared by direct reaction of high-purity elemental copper, indium and selenium. CuInSe₂ thin films were deposited onto well-cleaned glass substrates by a hot wall deposition technique using quartz tubes of different lengths (0.05, 0.07, 0.09, 0.11 and 0.13 m). X-ray diffraction studies revealed that all the deposited films are polycrystalline in nature and exhibit chalcopyrite structure. The crystallites were found to have a preferred orientation along the (1 1 2) direction. Micro-structural parameters of the films such as grain size, dislocation density, tetragonal distortion and strain have been determined. The grain sizes in the films were in the range of 65-250 nm. As the tube length increases up to 0.11 m the grain size in the deposited films increases, but the strain decreases. The film deposited using the 0.13 m long tube has smaller grain size and more strain. CuInSe₂ thin films coated using a tube length of 0.11 m were found to be highly crystalline when compared to the films coated using other tube lengths; it has also been found that films possess the same composition (Cu/In=1.015) as that of the bulk. Scanning electron microscope analysis indicates that the films are polycrystalline in nature. Structural parameters of CuInSe₂ thin films deposited under higher substrate temperatures were also studied and the results are discussed. The optical absorption coefficient of CuInSe₂ thin films has been estimated as 10⁴ cm⁻¹ (around 1050 nm). The direct band gap of CuInSe₂ thin films was also determined to be between 1.018 and 0.998 eV.     

Antimicrobial coatings produced by “tethering” biocides to the coating matrix: A comprehensive review

Covalently attached, non-leaching biocidal-moieties are being explored as an environmentally friendly option for replacing antimicrobial coatings that release biocides. This review highlights studies on antimicrobial surface treatments and coatings in which the antimicrobial agent is covalently bound (i.e. tethered) to the surface or coating matrix. In addition, test methods for measuring antimicrobial surface activity are reviewed, and a discussion of advantages and disadvantages of the various methods is provided.     

Buckling initiation and displacement dependence in compression of vertically aligned carbon nanotube arrays

Carbon nanotube (CNT) arrays have shown the remarkable ability to react as foam-like structures and exhibit localized buckling coordinated within specific regions. Here, we report on the low-cycle compression of bulk vertically aligned CNT arrays to observe initiation and growth of the buckling as a function of compressive strain. A critical strain is found above which the buckling region length increased and below which it remained at or below the applied strain. As previously observed, the buckling region of the CNT array propagates from the surface where growth occurred, which, in the test specimen, is a free surface and later receives compressive contact by a polished silicon substrate. The results are corroborated with nanoindentation on the surfaces, which indicate a stiffening of the near surface with increasing applied strain. Observation and results of the buckling region nature are important for applications of nanotube arrays as energy absorbing cushions, tunable dampers, thermal contacts, or in sliding contact.