2,280 research outputs found
Sperimagnetism in Fe(78)Er(5)B(17) and Fe(64)Er(19)B(17) metallic glasses: II. Collinear components and ferrimagnetic compensation
Magnetization measurements on an Fe(64)Er(19)B(17) glass and polarized-beam neutron scattering measurements on Fe(78)Er(5)B(17) and Fe(64)Er(19)B(17) were described in part I. The finite spin-flip neutron scattering cross sections were calculated using a sperimagnetic structure based on random cone arrangements of the magnetic moments. The temperature variation of the cross sections of Fe(64)Er(19)B(17) suggested that a compensated sperimagnetic phase existed at T(comp).
The analysis of the non-spin-flip neutron scattering cross sections is described here in part II. Two spin-dependent total structure factors S(+/-+/-). (Q) were defined from these cross sections and, despite the limited range of the data 0.5 angstrom(-1) , are zero on both sublattices in the compensated sperimagnetic structure at T(comp). The pre-peak in the spin-dependent total structure factors at 112 K showed that it originated in the atomic structure and it may involve Fe-Er-Fe 'collineations' at a radial distance of approximate to 6.0 angstrom. Finally, the RDF(+/-+/-) (r) of Fe(64)Er(19)B(17) at 180 K and of Fe(78)Er(5)B(17) at 2 K show that both glasses have the (mu(Fe) UP:mu(Er) DOWN) structure like the (Fe, Tb)(83)B(17) collinear ferrimagnets
Traumatic events in the life of the deep-sea cephalopod mollusc, the coleoid Spirula spirula
Here, we report on different types of shell pathologies of the enigmatic deep-sea (mesopelagic) cephalopod Spirula spirula. For the first time, we apply non-invasive imaging methods to: document trauma-induced changes in shell shapes, reconstruct the different causes and effects of these pathologies, unravel the etiology, and attempt to quantify the efficiency of the buoyancy apparatus. We have analysed 2D and 3D shell parameters from eleven shells collected as beach findings from the Canary Islands (Gran Canaria and Fuerteventura), West-Australia, and the Maldives. All shells were scanned with a nanotom-m computer tomograph. Seven shells were likely injured by predator attacks: fishes, cephalopods or crustaceans, one specimen was infested by an endoparasite (potentially Digenea) and one shell shows signs of inflammation and one shell shows large fluctuations of chamber volumes without any signs of pathology. These fluctuations are potential indicators of a stressed environment. Pathological shells represent the most deviant morphologies of a single species and can therefore be regarded as morphological end-members. The changes in the shell volume / chamber volume ratio were assessed in order to evaluate the functional
tolerance of the buoyancy apparatus showing that these had little effect.
Key words: pathology; parasitism; Spirula; mesopelagic; ecology; predator; buoyancy; cephalopod
Constructive updating/downdating of oblique projectors: a generalization of the Gram-Schmidt process
A generalization of the Gram-Schmidt procedure is achieved by providing
equations for updating and downdating oblique projectors. The work is motivated
by the problem of adaptive signal representation outside the orthogonal basis
setting. The proposed techniques are shown to be relevant to the problem of
discriminating signals produced by different phenomena when the order of the
signal model needs to be adjusted.Comment: As it will appear in Journal of Physics A: Mathematical and
Theoretical (2007
Large magnetic anisotropy in Ferrihydrite nanoparticles synthesized from reverse micelles
Six-line ferrihydrite(FH) nanoparticles have been synthesized in the core of
reverse micelles, used as nanoreactors to obtain average particle sizes
2 to 4 nm. The blocking temperatures extracted from
magnetization data increased from to 20 K for increasing particle
size. Low-temperature \MOS measurements allowed to observe the onset of
differentiated contributions from particle core and surface as the particle
size increases. The magnetic properties measured in the liquid state of the
original emulsion showed that the \FH phase is not present in the liquid
precursor, but precipitates in the micelle cores after the free water is
freeze-dried. Systematic susceptibility \chi_{ac}(\emph{f},T) measurements
showed the dependence of the effective magnetic anisotropy energies
with particle volume, and yielded an effective anisotropy value of kJ/m.Comment: 8 pages, 10 figures. Nanotechnology, v17 (Nov. 2006) In pres
Institutional maintenance of macroeconomic equilibrium and well-being
Goodwill component changes the pricing mechanism and gives the production of knowledge marketable character, complementing its with cognitive component. The paper substantiates the need to institute a regulated competitive market order as the search strategy of social sustainable balance consolidated on the basis of the reproduction cognitive capital process
European wind turbine testing procedure developments. Task 1: Measurement method to verify wind turbine performance characteristics
Transformation of Quartz to Tridymite in the Presence of Binary Silicate Liquids
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66429/1/j.1151-2916.1967.tb15146.x.pd
Smartphone-based cardiac implantable electronic device remote monitoring: improved compliance and connectivity
Aims: Remote monitoring (RM) is the standard of care for follow up of patients with cardiac implantable electronic devices. The aim of this study was to compare smartphone-based RM (SM-RM) using patient applications (myMerlinPulse™ app) with traditional bedside monitor RM (BM-RM). Methods and results: The retrospective study included de-identified US patients who received either SM-RM or BM-RM capable of implantable cardioverter defibrillators or cardiac resynchronization therapy defibrillators (Abbott, USA). Patients in SM-RM and BM-RM groups were propensity-score matched on age and gender, device type, implant year, and month. Compliance with RM was quantified as the proportion of patients enrolling in the RM system (Merlin.net™) and transmitting data at least once. Connectivity was measured by the median number of days between consecutive transmissions per patient. Of the initial 9714 patients with SM-RM and 26 679 patients with BM-RM, 9397 patients from each group were matched. Remote monitoring compliance was higher in SM-RM; significantly more patients with SM-RM were enrolled in RM compared with BM-RM (94.4 vs. 85.0%, P < 0.001), similar number of patients in the SM-RM group paired their device (95.1 vs. 95.0%, P = 0.77), but more SM-RM patients transmitted at least once (98.1 vs. 94.3%, P < 0.001). Connectivity was significantly higher in the SM-RM, with patients transmitting data every 1.2 (1.1, 1.7) vs. every 1.7 (1.5, 2.0) days with BM-RM (P < 0.001) and remained better over time. Significantly more SM-RM patients utilized patient-initiated transmissions compared with BM-RM (55.6 vs. 28.1%, P < 0.001). Conclusion: In this large real-world study, patients with SM-RM demonstrated improved compliance and connectivity compared with BM-RM
Membrane shape as a reporter for applied forces
Recent advances have enabled 3-dimensional reconstructions of biological structures in vivo, ranging in size and complexity from single proteins to multicellular structures. In particular, tomography and confocal microscopy have been exploited to capture detailed 3-dimensional conformations of membranes in cellular processes ranging from viral budding and organelle maintenance to phagocytosis. Despite the wealth of membrane structures available, there is as yet no generic, quantitative method for their interpretation. We propose that by modeling these observed biomembrane shapes as fluid lipid bilayers in mechanical equilibrium, the externally applied forces as well as the pressure, tension, and spontaneous curvature can be computed directly from the shape alone. To illustrate the potential power of this technique, we apply an axial force with optical tweezers to vesicles and explicitly demonstrate that the applied force is equal to the force computed from the membrane conformation
coupling determined beyond the chiral limit
Within the conventional QCD sum rules, we calculate the coupling
constant, , beyond the chiral limit using two-point correlation
function with a pion. We consider the Dirac structure, , at
order, which has clear dependence on the PS and PV coupling schemes
for the pion-nucleon interactions. For a consistent treatment of the sum rule,
we include the linear terms in quark mass as they constitute the same chiral
order as . Using the PS coupling scheme for the pion-nucleon
interaction, we obtain , which is very close to the
empirical coupling. This demonstrates that going beyond the chiral
limit is crucial in determining the coupling and the pseudoscalar coupling
scheme is preferable from the QCD point of view.Comment: 8 pages, revtex, some errors are corrected, substantially revise
- …