Thermal conductivity of ME771 glass-epoxy laminate from millikelvin temperatures to 4 K

Permaglas ME771 is a glass-epoxy laminate which is suitable for use at cryogenic temperatures. We have measured the thermal conductivity of a sample of this material between 64 mK and 4.2 K in the direction parallel to the reinforcing fibres, enabling us to make a comparison with the better known material G-10CR. The thermal conductivity follows the form that would be expected for such a material, and is similar to that of G-10CR, which has a similar (room temperature) tensile strength. We comment on some confusion that has arisen over the difference between G-10CR, a material specifically produced for cryogenic use, and G-10, the more common equivalent.     

Application of near (NIR) infrared and mid (MIR) infrared spectroscopy as a rapid tool to classify extra virgin olive oil on the basis of fruity attribute intensity

A sensory analysis of 112 virgin olive oils was performed by a fully trained taste panel. The samples were divided in “defective” and “not defective” on the basis of their olfactory attributes. Then, the “not defective” samples were classified into “low”, “medium” and “high” according to the fruity aroma intensity perceived by assessors. All samples were also analysed by FT-NIR and FT-IR spectroscopy and processed by classification methods (LDA and SIMCA). The results showed that NIR and MIR spectroscopy coupled with statistical methods are an interesting technique compared with traditional sensory assessment in classifying olive oil samples on the basis of the fruity attribute. The prediction rate varied between 71.6% and 100%, as average value. The spectroscopic methods, combined with chemometric strategies, could represent a reliable, cheap and fast classification tool, able to draw a complete fingerprint of a food product, describing its intrinsic quality attributes, that include its sensory attributes.     

Synthesis of Autosymmetric Functions in a New Three-Level Form

Autosymmetric functions exhibit a special type of regularity that can speed-up the minimization process. Based on this autosymmetry, we propose a three level form of logic synthesis, called ORAX (EXOR-AND-OR), to be compared with the standard minimal SOP (Sum of Products) form. First we provide a fast ORAX minimization algorithm for autosymmetric functions. The ORAX network for a function f has a first level of at most 2(n−k) EXOR gates, followed by the AND-OR levels, where n is the number of input variables and k is the “autosymmetry degree” of f. In general a minimal ORAX form has smaller size than a standard minimal SOP form for the same function. We show how the gain in area of ORAX over SOP can be measured without explicitly generating the latter. If preferred, a SOP expression can be directly derived from the corresponding ORAX. A set of experimental results confirms that the ORAX form is generally more compact than the SOP form, and its synthesis is much faster than classical three-level logic minimization. Indeed ORAX and SOP minimization times are often comparable, and in some cases ORAX synthesis is even faster.     

Effect of the Phase Composition of Barium-Calcium Alumoscandates on the Emission Properties of Impregnated Cathodes

The effect of scandium oxide additions on the emission properties of impregnated tungsten cathodes was investigated. The synthesis of alumoscandates in the BaO ― CaO ― Sc₂O₃ ― Al₂O₃ system were studied by x-ray diffraction, thermography, and petrographic analysis. The hygroscopic properties of the emission-active material was determined. Based on the results of emission tests the recommended optimal compositions of emission-active material are 2.4 BaO·0.6 CaO·0.1 Sc₂O₃·0.9 Al₂O₃ and 2.6 BaO·1.9 CaO·0.1 Sc₂O₃·0.9 Al₂O₃. Cathodes based on these compositions had lifetimes greater than 10000 h operating in the temperature range 900-1000°C at current densities of 15-20 A/cm² in a vacuum of the order of 10⁻⁶ Torr.

     

An effective multipurpose building block for 3D electropolymerisation: 2,2′-Bis(2,2′-bithiophene-5-yl)-3,3′-bithianaphthene

Novel thiophene-based oligomer, 2,2′-bis(2,2′-bithiophene-5-yl)-3,3′-bithianaphthene (TX), was designed and synthesized, and its electrochemical and spectral properties characterised. TX was readily polymerised electrochemically to form well organized conducting homopolymer films on various solid electrode substrates. Moreover, it was successfully used for deposition by electropolymerisation of electrochemically active thin films of co-polymers with three different monomers of functionalised bis(2,2′-bithienyl)methane derivatives. It appeared that TX was an effective crosslinker and 3D promoter in these electropolymerisations involving co-monomers intrinsically showing limited aptitude for the electropolymerisation or forming polymer films of low conductivity. This attractive TX ability stems from combination of its (i) high conjugation efficiency in each of the two planar moieties, (ii) intrinsic 3D structure on account of the presence of the central node, and (iii) intrinsic regioselectivity in electropolymerisation on account of the positions of the two available free α-thiophene sites.     

UNICORE 6 — Recent and Future Advancements

UNICORE is a European Grid Technology with more than 10 years of history. Originating from the Supercomputing domain, the latest version UNICORE 6 has turned into a general-purpose Grid technology that follows established standards and offers a rich set of features to its users. The paper starts with an architectural insight into UNICORE 6, highlighting the workflow features, standards and the different clients. Next, the current state of advancement is presented by describing recent developments. The paper closes with an outlook on future planned developments.     

Confirmation of brand identity in foods by near infrared transflectance spectroscopy using classification and class-modelling chemometric techniques — The example of a Belgian beer

Food and beverage processors require tools to monitor conformance of finished goods to their defined specification; regulatory authorities need appropriate methods for detecting retail fraud. In this report, samples (n = 275) of Belgian and other European beers were collected and analysed using near infrared transflectance spectroscopy; three class-modelling techniques (soft independent modelling of class analogy, SIMCA; potential functions techniques, POTFUN; and unequal dispersed classes, UNEQ) were employed to characterise beer types (firstly Trappist and then Rochefort) while a classification method (partial least squares discriminant analysis, PLS-DA) was applied to discriminate between two final beer classes: Rochefort 8° and Rochefort 10°. The class-models and the classification rules developed were validated by means of an external prediction set. A discussion on the appropriate use of these chemometric approaches is included. Modelling of Trappist beers met with limited success while model efficiencies for Rochefort samples were highest for SIMCA and UNEQ applications i.e. 81.4% and 84.5% respectively. The classification of beers as Rochefort 8? or Rochefort 10? was possible with an average correct classification rate of 93.4%.     

On total internal reflection investigation of nanoparticles by integrated micro-fluidic system

We report on a novel sensor for characterization of nanoparticles colloidal suspensions. We employ a diffraction grating under total internal reflection for investigation of nanodisperse fluids passing through an integrated microfluidic channel. Dispersions containing polymeric, metallic, and ferromagnetic nanoparticles are studied. Using this device, we can accurately determine in real-time the specific refractive index for the nanoparticle suspension and the nanoparticle concentration. The nanoparticle concentrations can be calculated with a resolution of 0.3-0.5 wt% for polymeric nanoparticles, 0.03-0.05 wt% for metallic nanoparticles, and 0.05-0.1 wt% for ferromagnetic nanoparticles. This translates to an effective refractive index that can be determined with an accuracy of 7 x 10(-4) for the polymeric and 2 x 10(-4) for the metallic and ferromagnetic dispersions.