Influence of plasma surface treatments on kink band formation in PBO fibers during compression

The effect of nitrogen and oxygen plasma surface treatments on the compressive strength of PBO fibers has been studied. To this end, the nucleation and propagation of compression‐induced kink bands was carefully monitored by means of in situ bending tests inside a scanning electron microscope. The micromechanisms of deformation were identical irrespective of fiber surface condition (either as‐received or modified by plasma) but the critical stress necessary to induce irreversible damage in compression in the nitrogen‐plasma treated fibers was 40% higher than in the as‐received fibers. This improvement occurred without any reduction in the fiber tensile properties. The source of this behavior is discussed in the light of the morphological and chemical changes induced by the plasma treatments on the fiber surface, as studied by AFM and XPS. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

The European contribution to the development and validation activities for the design of IFMIF lithium facility

The International Fusion Materials Irradiation Facility (IFMIF) is an accelerator-driven intense neutron source where candidate materials for fusion reactors will be tested and validated. The high energy neutron flux is produced by means of two deuteron beams (total current of 250 mA, energy of 40 MeV) that strikes a liquid lithium target circulating in a lithium loop of IFMIF plant. The European (EU) contribution to the development of the lithium facility comprises five procurement packages, as follow: (1) participation to the experimental activities of the EVEDA lithium test loop in Oarai (Japan); (2) study aimed at evaluating the corrosion and erosion phenomena, promoted by lithium, for structural fusion reference materials like AISI 316L and Eurofer; (3) design and validation of the lithium purification method with the aim to provide input data for the design of the purification system of IFIMF lithium loop; (4) design and validation of the remote handling (RH) procedures for the refurbishment/replacement of the EU concept of IFMIF target assembly including the design of the remote handling tools; (5) the engineering design of the European target assembly for IFMIF and the safety and RAMI analyses for the entire IFMIF lithium facility.The paper gives an overview of the status of the activities and of the main outcomes achieved so far.     

Preparation of Nonfragmented,Completely Amorphous,Pregelatinized Maize Starches and Determination of the Effects of Fragmentation on the Adhesiveness of Their Pastes

The objective of this research was to prepare pregelatinized maize starches that were both completely amorphous (no crystalline structure) and unfragmented, and to apply the same method to partially depolymerized maize starches to determine the effect of fragmentation on the degree of stickiness (tackiness, adhesiveness). Amorphous pregelatinized normal maize starch could be prepared by precipitation of a paste with acetone. Precipitation with a polar organic solvent was not applicable for the preparation of amorphous, pregelatinized waxy maize starch, because a sticky, cohesive and adhesive mass was produced. Therefore, freeze drying was used to prepare amorphous pregelatinized waxy maize starch. Limited acid‐catalyzed hydrolysis of normal maize starch before pregelatinization increased stickiness up to a maximum, after which the degree of stickiness decreased. In all aspects of this research, it was clear that the behavior of waxy maize starch was rather different than that of normal maize starch.     

Individual differences for self-regulating task-oriented reading activities.

The goal of this study is to analyze the self-regulation processes present in task-oriented reading activities. In the 1st experiment, we examined the following self-regulation processes in the context of answering questions about an available text: (a) monitoring the comprehension of the question, (b) self-regulating the search process, and (c) monitoring the decision to search. Skilled and less skilled comprehenders from 7th and 8th grades read 2 texts and answered 16 questions while all their actions were recorded on a computer. We hypothesized that skilled comprehenders would differ from less skilled comprehenders on the 1st 2 processes on the basis of their general comprehension skills but that their superiority in the 3rd process would be based on specific characteristics of the interaction between the reader and the text. The results support our hypotheses. In the 2nd experiment, we hypothesized that monitoring the decision to search would be equivalent to judgments of learning (JOLs). Eighth graders made JOLs before answering every question, and then they decided whether to search the text. Our hypothesis was confirmed. Our study reveals that task-oriented reading places specific demands on readers related to metacognitive monitoring. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electrical and optical switching properties of ion implanted VO2 thin films

The metal-insulator transition in vanadium dioxide thin films implanted with O⁺ ions was studied. Ion implantation lowered the metal-insulator transition temperature of the VO₂ films by 12 °C compared to the unimplanted ones, as measured both optically and electrically. The lowering of the transition temperature was accomplished without significantly reducing the mid-wave infrared optical transmission in the insulating state for wavelengths > 4.3 μm. Raman spectroscopy was used to examine changes to the crystalline structure of the implanted films. The Raman spectra indicate that ion implantation effects are not annealed out for temperatures up to 120 °C.     

Towards a water–energy–food nexus policy: realizing the blue and green virtual water of agriculture in Jordan

Virtual water is an important addendum to how we view a country's water resources. This study examines the virtual water embedded in Jordan's agricultural produce and its impact on future water–energy–food policies. Blue and green virtual waters are calculated from data on rainfall, crop patterns, yields, and water requirements at the district level. Results highlight the advantages of blue water usage in the Jordan Valley and of harnessing more available green water in the Highlands, with both displaying low energy impact. Results also emphasize the high groundwater usage and energy footprint in the Desert regions, signalling a need to rein in groundwater extraction and take advantage of solar power.     

Vitamin C and sugar levels as simple markers for discriminating Spanish honey sources

In this work, 7 Spanish honeys with different botanical origins were studied. The honey origins were rosemary, chestnut, lavender, echium, thyme, multifloral, and honeydew. The chemical compounds determined were ascorbic acid (vitamin C), hydroxymethylfurfural, and major sugar contents (glucose and fructose). The physicochemical parameters, pH, conductivity, moisture, free acidity, and color, were also measured. Vitamin C is an important antioxidant in food, and the possibility to use it as discriminate parameter among different honeys was studied. The determination of vitamin C in honey samples was carried out by 2 different methods, volumetric and chromatographic comparing the results by both statistically. Vitamin C content was higher in thyme honeys than in the other types; however a wide dispersion in the values was found. Through a linear discriminant analysis (LDA), conductivity, glucose, fructose, and vitamin C content were the most important discriminant parameters. PRACTICAL APPLICATION: Vitamin C content in different honey sources has been determined by a simple and rapid chromatographic method (less than 3 min) in honeys from 6 botanical origins. The results together with glucose and fructose content and some physicochemical parameters have been studied in order to discriminate the botanical origin of honeys and in the future certified their quality. A statistical LDA was applied to the data, and differentiation of honey sources was possible with very good agreement. The vitamin C content found in thymus honeys was significantly higher than in other types. This fact makes vitamin C a special marker for thymus honeys that have a higher antioxidant effect than the others giving it special properties. The identification of honey sources is essential for beekeepers in order to certify honeys for consumers.     

Analysis of pesticide residues in sugarcane juice using QuEChERS sample preparation and gas chromatography with electron capture detection

QuEChERS sample preparation was used for the determination of 7 pesticides residues in 80 samples of sugarcane juice collected from two Brazilian cities, in two different periods. The method involved extraction with acetonitrile, liquid–liquid partition with addition of MgSO₄ and NaCl followed by dispersive SPE cleanup with PSA sorbent and the analyses were carried out with a GC–ECD equipment. The method was validated using sugarcane juice spiked at 0.025, 0.10 and 0.20 mg/L and the average recovery by the method varied from 62.9% to 107.5% with RSDs < 18%. The method showed good linearity and the LODs for the pesticides studied ranged from 0.003 to 0.04 mg/L. No pesticide residue was detected (>LOD) amongst the 80 samples analysed.