113 research outputs found

    A constant magnetocaloric response in FeMoCuB amorphous alloys with different FeB ratios 

    Get PDF
    The magnetocaloric effect of Fe91−xMo8Cu1Bx (x = 15 , 17 , 20) amorphous alloys has been studied. The temperature of the peak of magnetic entropy change can be tuned by altering the Fe / B ratio in pk pk the alloy, without changing its magnitude, ILlSM I. The average contribution of the Fe atoms to ILlSM I increases with increasing B content. This is correlated with the increase in the low temperature mean magnetic moment of Fe. A recently proposed master curve behavior for the magnetic entropy change is also followed by these alloys and is common for all of them

    Biomarkers for Monitoring Pre-Analytical Quality Variation of mRNA in Blood Samples

    Get PDF
    Abstract There is an increasing need for proper quality control tools in the pre-analytical phase of the molecular diagnostic workflow. The aim of the present study was to identify biomarkers for monitoring pre-analytical mRNA quality variations in two different types of blood collection tubes, K 2 EDTA (EDTA) tubes and PAXgene Blood RNA Tubes (PAXgene tubes). These tubes are extensively used both in the diagnostic setting as well as for research biobank samples. Blood specimens collected in the two different blood collection tubes were stored for varying times at different temperatures, and microarray analysis was performed on resultant extracted RNA. A large set of potential mRNA quality biomarkers for monitoring postphlebotomy gene expression changes and mRNA degradation in blood was identified. qPCR assays for the potential biomarkers and a set of relevant reference genes were generated and used to pre-validate a sub-set of the selected biomarkers. The assay precision of the potential qPCR based biomarkers was determined, and a final validation of the selected quality biomarkers using the developed qPCR assays and blood samples from 60 healthy additional subjects was performed. In total, four mRNA quality biomarkers (USP32, LMNA, FOSB, TNRFSF10C) were successfully validated. We suggest here the use of these blood mRNA quality biomarkers for validating an experimental pre-analytical workflow. These biomarkers were further evaluated in the 2 nd ring trial of the SPIDIA-RNA Program which demonstrated that these biomarkers can be used as quality control tools for mRNA analyses from blood samples

    The energy gap of intermediate-valent SmB6 studied by point-contact spectroscopy

    Full text link
    We have investigated the intermediate valence narrow-gap semiconductor SmB6 at low temperatures using both conventional spear-anvil type point contacts as well as mechanically controllable break junctions. The zero-bias conductance varied between less than 0.01 mikrosiemens and up to 1 mS. The position of the spectral anomalies, which are related to the different activation energies and band gaps of SmB6, did not depend on the the contact size. Two different regimes of charge transport could be distinguished: Contacts with large zero - bias conductance are in the diffusive Maxwell regime. They had spectra with only small non-linearities. Contacts with small zero - bias conductance are in the tunnelling regime. They had larger anomalies, but still indicating a finite 45 % residual quasiparticle density of states at the Fermi level at low temperatures of T = 0.1 K. The density of states derived from the tunelling spectra can be decomposed into two energy-dependent parts with Eg = 21 meV and Ed = 4.5 meV wide gaps, respectively.Comment: 9 pages incl. 13 figure

    Miocene waterfowl and other birds from central Otago, New Zealand

    Get PDF
    Copyright © The Natural History Museum 2007Abundant fossil bird bones from the lower Bannockburn Formation, Manuherikia Group, an Early-Middle Miocene lacustrine deposit, 16–19 Ma, from Otago in New Zealand, reveal the “St Bathans Fauna” (new name), a first Tertiary avifauna of land and freshwater birds from New Zealand. At least 23 species of birds are represented by bones, and probable moa, Aves: Dinornithiformes, by eggshell. Anatids dominate the fauna with four genera and five species described as new: a sixth and largest anatid species is represented by just one bone. This is the most diverse Early-Middle Miocene duck fauna known worldwide. Among ducks, two species of dendrochenines are most numerous in the fauna, but a tadornine is common as well. A diving petrel (Pelecanoididae: Pelecanoides) is described, so extending the geological range of this genus worldwide from the Pliocene to the Middle Miocene, at least. The remaining 16 taxa are left undescribed but include: a large species of gull (Laridae); two small waders (Charadriiformes, genus indet.), the size of Charadrius bicinctus and Calidris ruficollis, respectively; a gruiform represented by one specimen similar to Aptornis; abundant rail (Rallidae) bones, including a common flightless rail and a rarer slightly larger taxon, about the size of Gallirallus philippensis; an ?eagle (Accipitridae); a pigeon (Columbidae); three parrots (Psittacidae); an owlet nightjar (Aegothelidae: Aegotheles sp.); a swiftlet (Apodidae: Collocalia sp.); and three passerine taxa, of which the largest is a member of the Cracticidae. The absence of some waterbirds, such as anserines (including swans), grebes (Podicipedidae) and shags (Phalacrocoracidae), among the abundant bones, indicates their probable absence from New Zealand in the Early-Middle Miocene.T. H. Worthy, A. J. D. Tennyson, C. Jones, J. A. McNamara and B. J. Dougla

    Mechanism of and Threshold Biomechanical Conditions for Falsetto Voice Onset

    Get PDF
    The sound source of a voice is produced by the self-excited oscillation of the vocal folds. In modal voice production, a drastic increase in transglottal pressure after vocal fold closure works as a driving force that develops self-excitation. Another type of vocal fold oscillation with less pronounced glottal closure observed in falsetto voice production has been accounted for by the mucosal wave theory. The classical theory assumes a quasi-steady flow, and the expected driving force onto the vocal folds under wavelike motion is derived from the Bernoulli effect. However, wavelike motion is not always observed during falsetto voice production. More importantly, the application of the quasi-steady assumption to a falsetto voice with a fundamental frequency of several hundred hertz is unsupported by experiments. These considerations suggested that the mechanism of falsetto voice onset may be essentially different from that explained by the mucosal wave theory. In this paper, an alternative mechanism is submitted that explains how self-excitation reminiscent of the falsetto voice could be produced independent of the glottal closure and wavelike motion. This new explanation is derived through analytical procedures by employing only general unsteady equations of motion for flow and solids. The analysis demonstrated that a convective acceleration of a flow induced by rapid wall movement functions as a negative damping force, leading to the self-excitation of the vocal folds. The critical subglottal pressure and volume flow are expressed as functions of vocal fold biomechanical properties, geometry, and voice fundamental frequency. The analytically derived conditions are qualitatively and quantitatively reasonable in view of reported measurement data of the thresholds required for falsetto voice onset. Understanding of the voice onset mechanism and the explicit mathematical descriptions of thresholds would be beneficial for the diagnosis and treatment of voice diseases and the development of artificial vocal folds

    Magnetostriction Measurements of (Fe-Co)-Mo-Cu-B Alloys with Varying Atomic Fe/Co Ratio

    No full text
    Amorphous rapidly quenched ribbons of (FeCo)76Mo8Cu1B15(Fe-Co)_{76}Mo_8Cu_1B_{15} with the ratio Co/Fe = 0, 1/9, 1/6, 1/4, 1/3, 1/2, 1/1 and 2/1 were prepared by planar flow casting. The dependence of the Curie temperature TCT_C on Co/Fe ratio was determined. Due to the presence of the invar effect it was possible to measure the spontaneous volume magnetostriction in the temperature interval between 300 K and TCT_C. Field dependences of magnetostriction in parallel and perpendicular directions of applied magnetic field were obtained by direct measurement method. Subsequently, saturation magnetostriction and volume magnetostriction as well as forced magnetostriction were computed. Saturation magnetostriction increases with increasing Co/Fe ratio from 0 up to 17 ppm, depending both on the Co/Fe ratio and on the shift of TCT_C with composition. The alloy with ratio Co/Fe = 0 exhibits TCT_C near room temperature, thus field dependences of magnetostriction, corresponding to the dependences of a paramagnetic system are practically linear functions of applied field, corresponding to paramagnetic state

    Effect of Temperature on Magnetization Processes in Amorphous Rapidly Solidified FeSiB/CoSiB Bilayer Ribbons

    No full text
    Amorphous bilayers consisting of Fe-Si-B and Co-Si-B layers have been prepared by planar flow casting from a single crucible using a double-nozzle technique. Temperature dependencies of magnetization and hysteresis loops have been investigated in a wide temperature range. At room temperature, the effects of interlayer stresses, induced in material due to different thermal expansion coefficients of two mechanically interconnected soft magnetic layers, resulted in rounded hysteresis loops with flattened central part, indicating a dominant role of magnetization rotational processes. With an increase of measurement temperature, the interlayer stresses are relieved and the hysteresis loops became more squared
    corecore