Interphase modification of alkali-resistant glass fibres and carbon fibres for textile reinforced concrete II: Water adsorption and composite interphases

The interaction between sizings and coatings is varied systematically resulting in different fibre surface modifications and interphase properties in cement matrix composites. The mechanical performance and the water adsorption of sized and coated alkali-resistant glass fibres (ARG) and the working capacity of the composites achieved are elucidated as a function of fibre diameter, sizing and coating content as well as their chemical formulations under special consideration of nanoclay concentrated within the interphase. Depending on the chemistry of the sizing and polymeric coating, respectively, the force–crack width curves together with hydration phase morphology derived from ESEM images of the concrete specimens are used to reveal composite interphases. Furthermore, the results achieved with nanodispersed polymeric coatings on glass fibres are transferred to carbon fibres and their concrete composites.     

Sparse Deconvolution Methods for Ultrasonic NDT

In this work we present two sparse deconvolution methods for nondestructive testing. The first method is a special matching pursuit (MP) algorithm in order to deconvolve the mixed data (signal and noise), and thus to remove the unwanted noise. The second method is based on the approximate Prony method (APM). Both methods employ the sparsity assumption about the measured ultrasonic signal as prior knowledge. The MP algorithm is used to derive a sparse representation of the measured data by a deconvolution and subtraction scheme. An orthogonal variant of the algorithm (OMP) is presented as well. The APM technique also relies on the assumption that the desired signals are sparse linear combinations of (reflections of) the transmitted pulse. For blind deconvolution, where the transducer impulse response is unknown, we offer a general Gaussian echo model whose parameters can be iteratively adjusted to the real measurements. Several test results show that the methods work well even for high noise levels. Further, an outlook for possible applications of these deconvolution methods is given.     

Monitoring uranium, hydrogen, and lithium and their isotopes using a compact laser-induced breakdown spectroscopy (LIBS) probe and high-resolution spectrometer

The development of field-deployable instruments to monitor radiological, nuclear, and explosive (RNE) threats is of current interest for a number of assessment needs such as the on-site screening of suspect facilities and nuclear forensics. The presence of uranium and plutonium and radiological materials can be determined through monitoring the elemental emission spectrum using relatively low-resolution spectrometers. In addition, uranium compounds, explosives, and chemicals used in nuclear fuel processing (e.g., tributyl-phosphate) can be identified by applying chemometric analysis to the laser-induced breakdown (LIBS) spectrum recorded by these spectrometers. For nuclear forensic applications, however, isotopes of U and Pu and other elements (e.g., H and Li) must also be determined, requiring higher resolution spectrometers given the small magnitude of the isotope shifts for some of these elements (e.g., 25 pm for U and 13 pm for Pu). High-resolution spectrometers will be preferred for several reasons but these must fit into realistic field-based analysis scenarios. To address the need for field instrumentation, we evaluated a previously developed field-deployable hand-held LIBS interrogation probe combined with two relatively new high-resolution spectrometers (λ/Δλ ~75,000 and ~44,000) that have the potential to meet field-based analysis needs. These spectrometers are significantly smaller and lighter in weight than those previously used for isotopic analysis and one unit can provide simultaneous wide spectral coverage and high resolution in a relatively small package. The LIBS interrogation probe was developed initially for use with low resolution compact spectrometers in a person-portable backpack LIBS instrument. Here we present the results of an evaluation of the LIBS probe combined with a high-resolution spectrometer and demonstrate rapid detection of isotopes of uranium and hydrogen and highly enriched samples of (6)Li and (7)Li.     

Cloning of Flax Oleic Fatty Acid Desaturase and Its Expression in Yeast

Fatty acid desaturases dehydrogenate acyl chains, which results in the formation of a double bond. Using PCR on flax genomic DNA, we cloned a putative Δ12 fatty acid desaturase (Fad2) gene encoding a 378 amino acid protein. Heterologous expression of this protein in yeast as an N-terminal fusion to GFP showed its localization within endoplasmic reticulum. Analysis of membrane lipids revealed the production of dienoic fatty acids, decreased levels of FAD2 substrates and an increased concentration of longer fatty acids. Higher peroxidation of lipids in FAD2-containing strains is not reflected by any visible phenotype in YPD medium. However, FAD2-containing strains with deleted superoxide dismutase genes exhibited significant growth reductions under oxidative stress.     

Der Rapid-Mix-Test als 10-g-Mikrobackversuch

Zusammenfassung Es wurde ein Mikrobackversuch (MRMT) mit 10 g Mehl entwickelt, der bezüglich Rezeptur, Teigführung und Teigbearbeitung mit dem Standardbackversuch (RMT), soweit technisch möglich, übereinstimmt. Die an 31 Winterweizensorten eines Standorts der Bayerischen Landessortenversuche, Ernte 1990, ermittelten Volumina der Mikrobrote sind mit den RMT-Volumina hoch korreliert (r=0,904). Auch Teigund Gebäckeigenschaften lassen sich beim MRMT gut bewerten.

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A 10-g micro-version of the rapid-mix-test

Summary A micro-baking test for 10-üg flour (MRMT) was developed which corresponds to the standard baking test (RMT) as far as technically possible with respect to formula, preparation and processing of the dough. It was shown for 31 winter wheat varieties (harvest 1990) from one location in Bavaria that the bread volumes obtained by MRMT and RMT are highly correlated (r=0.904). The properties of dough and bread can also be judged very well by the MRMT.

     

Mycetozoal bloom in a hydroponic culture of garden cress (Lepidium sativum L.)

The role and importance of the true slime moulds (mycetozoans, Mycetozoa, formerly Myxomycetes) for agriculture and food industry are poorly documented, most probably because of a low popularity of these “macroscopic microorganisms” among researchers in the past. Here we report probably for the first time the massive occurrence of true slime moulds in their vegetative, plasmodial form in a product intended for direct consumption, i.e. in a household hydroponic culture of garden cress (Lepidium sativum L.). The plasmodia gradually produced numerous, stalked or sessile sporangia and plasmodiocarps, which made it possible to identify them as Didymium species complex (the stalked sporangia) and Didymium difforme (Pers.) Gray (the sessile sporangia and plasmodiocarps). The mycetozoans were transferred to in vitro culture where they were maintained for several weeks on oat flour. We briefly discuss the importance of this observation from the point of view of biochemical interactions between the plant and the true slime moulds in a general context of slime mould biology. Our observation indicates that the presence of mycetozoan material in food products may be frequent, while its influence on food safety and quality remains unknown.