Prediction of the Mechanical Properties of P91 Steel by Means of Magneto-acoustic Emission and Acoustic Birefringence

The paper describes an application of non-destructive volumetric magnetic and ultrasonic techniques for evaluation of the selected mechanical parameter variations of P91 steel having direct influence on its suitability for further use in critical components used in power plants. Two different types of deformation processes were carried out. First, a series of the P91 steel specimens was subjected to creep and second, one to plastic deformation in order to achieve the material with an increasing strain level up to 10%. Subsequently, non-destructive and destructive tests were performed. Magnetic methods based on measurements of magnetoacoustic emission and magnetic hysteresis loop changes as well as the ultrasonic method based on acoustic birefringence measurements, were applied. Finally, the static tensile tests were carried out in order to evaluate the mechanical parameters. It is shown that some relationships between the selected parameters coming from the non-destructive and destructive tests may be formulated.     

Lipophilic Defenses From Alcyonium Soft Corals of Antarctica

Alcyonacean soft corals lack physical or skeletal defenses and their nematocyst system is weak, leading to the conclusion that soft corals mainly rely on chemistry for protection from predators and microbes. Defensive chemicals of primary and secondary metabolic origin are exuded in the mucus surface layer, explaining the general lack of heavy fouling and predation in corals. In Antarctic ecosystems, where generalist predation is intense and mainly driven by invertebrate consumers, the genus Alcyonium is represented by eight species. Our goal was to investigate the understudied chemical ecology of Antarctic Alcyonium soft corals. We obtained six samples belonging to five species: A. antarcticum, A. grandis, A. haddoni, A. paucilobulatum, and A. roseum, and assessed the lipid-soluble fractions for the presence of defensive agents in these specimens. Ethyl ether extracts were tested in feeding bioassays with the sea star Odontaster validus and the amphipod Cheirimedon femoratus as putative sympatric predators. Repellent activities were observed towards both consumers in all but one of the samples assessed. Moreover, three of the extracts caused inhibition to a sympatric marine bacterium. The ether extracts afforded characteristic illudalane sesquiterpenoids in two of the samples, as well as particular wax esters subfractions in all the colonies analyzed. Both kinds of metabolites displayed significant deterrent activities demonstrating their likely defensive role. These results suggest that lipophilic chemicals are a first line protection strategy in Antarctic Alcyonium soft corals against predation and bacterial fouling.     

Consumer perception and use of iron fortified foods is associated with their knowledge and understanding of nutritional issues

Aim

We hypothesised that consumer perception on iron fortified foods and consequent introduction of such products to their diets may depend on their knowledge and understanding on nutritional issues, particularly in relation to iron.

Methods

500 men and women (age 30 ± 12 years) from Athens, Xylokastro, in South Greece and Lamia, in Central Greece participated to the study. Participants were asked about their knowledge in nutritional issues using 28 true/false/do not know questions. These “overall nutrition knowledge” questions were grouped as “general nutrition knowledge” and “iron nutrition knowledge” questions. Answers scored 1, −1 or 0 when correct, wrong or “do not know” respectively. Thus, three different scores were produced, specifically the “overall nutrition knowledge” score, ranging from −28 to 28 and from this, the “general nutrition knowledge” score, ranging from −10 to 10, and the “iron nutrition knowledge” score, ranging from −18 to 18. Perception and consumption of iron fortified products were evaluated and associated with the scores.

Results

Unadjusted logistic regression analysis revealed that one point increase of overall nutrition knowledge score was associated with 4.3% higher likelihood that the consumer believes that iron fortified foods have a positive role in diet (OR = 1.043, 90% CI 1.040-1.080). One point increase of iron nutrition knowledge score was associated with 20% higher likelihood of consuming iron fortified foods more often (OR = 1.200, 90% CI 1.074-1.340).

Conclusions

Consumer perception on iron fortified foods seems to be associated with nutrition knowledge and highlight the importance of focused nutrition education in consumer informed choices.     

Comparison of marital observational measures: The Marital Interaction Coding System and the Communication Skills Test.

The Marital Interaction Coding System (MICS) and the Communication Skills Test (CST) were compared empirically to determine the similarities and differences in the assessment data obtained from these observational measures. Videotaped marital conflict-resolution discussions of 47 married couples were coded with both systems. The results revealed that scores on the summary categories of positive and negative behaviors derived from the MICS and the CST generally were not significantly correlated. Instead, the data from the two coding systems showed different patterns of results. Husband–wife correlations for positive and negative behaviors differed for the two coding systems, and subgroups of distressed (n?=?15) and nondistressed (n?=?15) spouses were discriminated by positive behaviors of the MICS but by negative behaviors on the CST. We consider reasons for the opposing results and suggest directions for improving marital observational coding procedures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Physico‐optical properties of a crosslinked hyaluronic acid scaffold for biomedical applications

Optical techniques are increasingly employed for monitoring cell–matrix interactions in suitably prepared 3D scaffolds. The ability of designing and realizing synthetic extracellular matrix with well‐controlled optical properties is a crucial need in this field. For this purpose, a crosslinked hyaluronic acid (HA) scaffold is prepared. Fourier transform infrared and ultraviolet–visible spectroscopies enable to monitor the scaffold preparation process and to evidence scaffold high transparency and low fluorescence in the visible range. 3D optical characteristics of the HA scaffold are tested by two‐photon microscopy (TPM) imaging of embedded fluorescent microbeads and alive keratinocytes labeled with vital PKH67 dye at different depths from the scaffold surface. Some useful indications about the potentiality of TPM measurements for the determination of attenuation coefficient of turbid media are also reported. Moreover, the use of the presented HA scaffold for preparing tissue phantoms for fluorescence imaging or diffuse imaging is proposed. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45243.     

2D Phononic Crystals: Progress and Prospects in Hypersound and Thermal Transport Engineering

The central concept in phononics is the tuning of the phonon dispersion relation, or phonon engineering, which provides a means of controlling related properties such as group velocity or phonon interactions and, therefore, phonon propagation, in a wide range of frequencies depending on the geometries and sizes of the materials. Phononics exploits the present state of the art in nanofabrication to tailor dispersion relations in the range of GHz for the control of elastic waves/phonons propagation with applications toward new information technology concepts with phonons as state variable. Moreover, phonons provide an adaptable approach for supporting a coherent coupling between different state variables, and the development of nanoscale optomechanical systems during the last decade attests this prospect. The most extended approach to manipulate the phonon dispersion relation is introducing an artificial periodic modulation of the elastic properties, which is referred to as phononic crystal (PnC). Herein, the focus is on the recent experimental achievements in the fabrication and application of 2D PnCs enabling the modification of the dispersion relation of surface and membrane modes, and presenting phononic bandgaps, waveguiding, and confinement in the hypersonic regime. Furthermore, these artificial materials offer the potential of modifying and controlling the heat flow to enable new schemes in thermal management.     

Decision-making criteria and indicators for water and sanitation projects in developing countries

Water and sanitation projects for solving the needs of small communities in developing countries are complex in nature and involve complex decision-making, which must consider technical, socioeconomic and environmental dimensions. Multicriteria analysis (MCA) is a suitable decision-aid method that scores a finite number of options on the basis of a set of evaluation criteria. The main challenge in MCA is choosing the appropriate criteria and evaluation indicators to use for assessment. The aim of this paper is to present a comprehensive and wide list of criteria and evaluation indicators as a guideline in MCA of water and basic sanitation projects in small rural communities of developing countries. First, the paper details the general criteria to be considered in all the projects, which are classified in to 4 main groups: technical (e.g., local resources use, appropriate management); social (e.g., local community participation, overcoming discrimination of conflict); economic (e.g., low cost, employment of local staff) and environmental criteria (e.g., atmospheric emissions, water pollution). Then, it describes technical criteria to be additionally considered in each specific type of project: water supply (e.g., water needs, independent access), water treatment (e.g., constant resource availability, flexibility of use for different types of water) and basic sanitation projects (e.g., maximum number of people per system, effluent quality).     

Interactions of n-Hexadecane with 52100 Steel Surface Under Friction Conditions

Straight-chain aliphatic hydrocarbons, particularly n-hexadecane, are used as reference fluids in research concerning the AW/EP effectiveness of triboactive additives. It is assumed, however, that under boundary lubrication conditions these apparently non-reactive hydrocarbons might influence the tribochemistry of the additives because aliphatic compounds also undergo chemical reactions. Both the thermochemical and tribochemical oxidation of aliphatic hydrocarbons lead to the formation of triboactive products (e.g. alcohols, aldehydes and carboxylic acids). Interactions of these compounds with rubbing surfaces were examined using GC/MS, XPS and EDS techniques. It has been found that carboxylic acids react with the iron surface generating salts or complex compounds.