1,475 research outputs found
Infrared Coronal Lines. II. Observation of [SI x] λ 1.43 μ and [Mg VIII] λ 3.03 μ
The wavelengths and intensities of the coronal lines of the ions Si^(9+) and Mg^(8+), resulting from the airborne observation of the November 12, 1966, total solar eclipse, are given
What are Hybrid Development Methods Made Of?
Regardless of company size or industry sector, a majority of project teams and companies use customized processes that combine different development methods-so-called hybrid development methods. Even though such hybrid development methods are highly individualized, a common understanding of how to systematically construct synergetic practices is missing. Based on 1,467 data points from a large-scale online survey among practitioners, we study the current state of practice in process use to answer the question: What are hybrid development methods made of? Our findings reveal that only eight methods and few practices build the core of modern software development. This small set allows for statistically constructing hybrid development methods
Infrared Spectra of Low-Temperature Stars
Spectra of stars of types M, N(R), and S, as well as of NML objects in Cygnus and Taurus, are presented in the regions ⋋⋋l 5-1.8 μ and ⋋⋋l 9-2 5 μ. In M stars the absorption due to stellar H_2O is apparent from the wings of the bands at ⋋l.4, ⋋l.9, and ⋋2.7 μ Stars of N and S types show weaker H_2O absorption. The Δv = 2 and Δv = 3 vibration-rotation band sequences of CO appear well marked in all stars, being somewhat weaker in the M types than in other stars. The late N stars Y CVn and U Hyd show a sharp discontinuity or band head at ⋋l.76 μ not present in other stars. The entire spectra of Y CVn and U Hyd shortward of this discontinuity appears veiled, the Δv = 3 CO band sequence being conspicuously weak. The spectra of the NML objects in Cygnus and Taurus have spectral characteristics
resembling the carbon more than the M stars
An Analysis of the Spectrum of Mars
On a high-dispersion spectrogram of Mars taken at Mount Wilson rotational lines of H_2O near λ 8300 and CO_2 near λ 8700 have been detected. Recent laboratory measurements of line strengths by D. Rank have been used to determine the amounts of H_2O and CO_2 in the atmosphere of Mars: 14 ± 7 μ precipitable water and 55 ± 20 m atm CO_2. From the absence of O_2 in the Martian spectra, we set an upper limit of 70 cm atm for the O_2 content.
By suitably combining the CO_2 amount with observations by Kuiper and Sinton of the strongly saturated bands in the 2-μ. region, a surface pressure of 25 ± 15 mb has been derived.
The implications of the results on the composition of the Martian atmosphere are discussed
Portable inhalation systemfor a dosed insulin supply
Интенсивная инсулинотерапия необходима для контроля состояния пациентов с диабетом.Несмотря на постоянное усовершенствование инсулинотерапии, все ещ? существует проблема неудобства режимов многократных инъекций инсулина. Целью данной работы является создание системы, позволяющей осуществлять ингаляцию инсулина.Intensive insulin therapy is necessary for the control of a condition diabetic patients. Despite the constant improvement of insulin therapy, there is still the problem of discomfort repeated regimes of insulin injections. The objective of this work is to create a system that allows the inhalation of insulin
Hypersurface Bohm-Dirac models
We define a class of Lorentz invariant Bohmian quantum models for N entangled
but noninteracting Dirac particles. Lorentz invariance is achieved for these
models through the incorporation of an additional dynamical space-time
structure provided by a foliation of space-time. These models can be regarded
as the extension of Bohm's model for N Dirac particles, corresponding to the
foliation into the equal-time hyperplanes for a distinguished Lorentz frame, to
more general foliations. As with Bohm's model, there exists for these models an
equivariant measure on the leaves of the foliation. This makes possible a
simple statistical analysis of position correlations analogous to the
equilibrium analysis for (the nonrelativistic) Bohmian mechanics.Comment: 17 pages, 3 figures, RevTex. Completely revised versio
The influence of constrictivity on the effective transport properties of porous layers in electrolysis and fuel cells
The aim of the present investigation is to define microstructure parameters, which control the effective transport properties in porous materials for energy technology. Recent improvements in 3D-imaging (FIB-nanotomography, synchrotron X-ray tomography) and image analysis (skeletonization and graph analysis, transport simulations) open new possibilities for the study of microstructure effects. In this study, we describe novel procedures for a quantitative analysis of constrictivity, which characterizes the so-called bottleneck effect. In a first experimental part, methodological tests are performed using a porous (La,Sr)CoO3 material (SOFC cathode). The tests indicate that the proposed procedure for quantitative analysis of constrictivity gives reproducible results even for samples with inhomogeneous microstructures (cracks, gradient of porosity). In the second part, 3D analyses are combined with measurements of ionic conductivity by impedance spectroscopy. The investigations are preformed on membranes of electrolysis cells with porosities between 0.27 and 0.8. Surprisingly, the tortuosities remain nearly constant (1.6) for the entire range of porosity. In contrast, the constrictivities vary strongly and correlate well with the measured transport resistances. Hence, constrictivity represents the dominant microstructure parameter, which controls the effective transport properties in the analysed membrane materials. An empirical relationship is then derived for the calculation of effective transport properties based on phase volume fraction, tortuosity, and constrictivit
Die informations- und kommunikationstechnische Infrastruktur und ihre mittelfristige Entwicklung an den Hochschulen des Landes NRW
Dieser Bericht des Arbeitskreises der Leiter wissenschaftlicher Rechenzentren in NRW (ARNW) richtet sich an die Hochschulleitungen und die Verantwortlichen für Grundstrukturen in Information und Kommunikation (IuK). Er informiert über aktuelle wichtige Fragen, besonders über den Stand und Einsatz von IuK-Technologien. In Anbetracht der anhaltend schnellen Weiterentwicklung dieses Technologiefeldes, die sich auf alle Bereiche der Hochschulen auswirkt, halten wir das für wichtig, damit vermieden wird, dass wichtige Themen am Rande bleiben. Das neue Hochschulgesetz und der Qualitätspakt machen darüber hinaus eine Positionierung der Hochschulen in NRW zur IuK-Infrastruktur unabdingbar
A Placenta Derived C-Terminal Fragment of beta-Hemoglobin With Combined Antibacterial and Antiviral Activity
Encoding difficulty promotes postlearning changes in sleep spindle activity during napping
Learning-dependent increases in sleep spindle density have been reported during nocturnal sleep immediately after the learning session. Here, we investigated experience-dependent changes in daytime sleep EEG activity after declarative learning of unrelated word pairs. At weekly intervals, 13 young male volunteers spent three 24 h sessions in the laboratory under carefully controlled homeostatic and circadian conditions. At approximately midday, subjects performed either one of two word-pair learning tasks or a matched nonlearning control task, in a counterbalanced order. The two learning lists differed in the level of concreteness of the words used, resulting in an easier and a more difficult associative encoding condition, as confirmed by performance at immediate cued recall. Subjects were then allowed to sleep for 4 h; afterward, delayed cued recall was tested. Compared with the control condition, sleep EEG spectral activity in the low spindle frequency range and the density of low-frequency sleep spindles (11.25-13.75 Hz) were both significantly increased in the left frontal cortex after the difficult but not after the easy encoding condition. Furthermore, we found positive correlations between these EEG changes during sleep and changes in memory performance between pre-nap and post-nap recall sessions. These results indicate that, like during nocturnal sleep, daytime sleep EEG oscillations including spindle activity are modified after declarative learning of word pairs. Furthermore, we demonstrate here that the nature of the learning material is a determinant factor for sleep-related alterations after declarative learning
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