128 research outputs found
Curie Point Pyrolysis Gas Chromatography
In Curie Point pyrolysis gas chromatography a ferromagnetic conductor in contact with the sample is heated inside a low volume glass capillary which is inserted into an rf coil with the carrier gas flowing through the capillary. The intrinsic properties of the conductor permit a self-control of the temperature to the Curie Point. The optimum wire diameter for a rapid warm-up is a function of the rf frequency. In order to have a fast temperature drop after cutting the rf field, small wire diameters are preferable. For such conductors relatively high frequencies are inherently necessary for a fast stabilization to the Curie Point. So far no differences in the self-controlled end-temperatures have been detected for wires of different origi
Controlling the stability transfer between oppositely traveling waves and standing waves by inversion-symmetry-breaking perturbations
The effect of an externally applied flow on symmetry degenerated waves
propagating into opposite directions and standing waves that exchange stability
with the traveling waves via mixed states is analyzed. Wave structures that
consist of spiral vortices in the counter rotating Taylor-Couette system are
investigated by full numerical simulations and explained quantitatively by
amplitude equations containing quintic coupling terms. The latter are
appropriate to describe the influence of inversion symmetry breaking
perturbations on many oscillatory instabilities with O(2) symmetry.Comment: 4 pages, 4 figure
Jets opposing turbidity currents and open channel flows
Hydraulic jumps at the tail end of spillways are usually induced by baffle blocks or other obstacles. Such jumps can also be induced by jets that oppose the main flow. Another application is to back up turbidity currents in reservoirs by means of opposing jets. This measure can be adopted when transfer tunnels feed water into the reservoir at a higher elevation near the dam. Stopping the turbidity current increases the local sedimentation rate. To reconcile the shallow water equations for turbidity currents with those for open channel flows, massbased scales for the depth and velocity of both types of flows are outlined. The continuity and momentum equation for flows opposed by jets are then stated in terms of these scales and expressed by a single curve for both gravity currents and free surface flows. The corresponding results for free surface flows agree well with those of experiments carried out for this study. An application to turbidity currents is provided as well
High-resolution measurement of the time-modulated orbital electron capture and of the decay of hydrogen-like Pm ions
The periodic time modulations, found recently in the two-body orbital
electron-capture (EC) decay of both, hydrogen-like Pr and
Pm ions, with periods near to 7s and amplitudes of about 20%,
were re-investigated for the case of Pm by using a 245 MHz
resonator cavity with a much improved sensitivity and time resolution. We
observed that the exponential EC decay is modulated with a period s, in accordance with a modulation period s as obtained
from simultaneous observations with a capacitive pick-up, employed also in the
previous experiments. The modulation amplitudes amount to and
for the 245 MHz resonator and the capacitive pick-up,
respectively. These new results corroborate for both detectors {\it exactly}
our previous findings of modulation periods near to 7s, though with {\it
distinctly smaller} amplitudes. Also the three-body decays have been
analyzed. For a supposed modulation period near to 7s we found an amplitude , compatible with and in agreement with the preliminary
result of our previous experiment. These observations could
point at weak interaction as origin of the observed 7s-modulation of the EC
decay. Furthermore, the data suggest that interference terms occur in the
two-body EC decay, although the neutrinos are not directly observed.Comment: In memoriam of Prof. Paul Kienle, 9 pages, 1 table, 5 figures Phys.
Lett. B (2013) onlin
Religious socialisation and fertility: transition to third birth in the Netherlands
Although previous studies have demonstrated that religious people in Europe have larger families, the role played by religious socialisation in the context of contemporary fertility behaviour has not yet been analysed in detail. This contribution specifically looks at the interrelation between religious socialisation and current religiosity and their impact on the transition to the third child for Dutch women. It is based on data of the first wave of the Netherlands Kinship Panel Study (2002â2004) and uses event history analysis. The transitions to first, second and third birth are modelled jointly with a control for unobserved heterogeneity. The findings provide evidence for an impact of womenâs current church attendance as well as religious socialisation measured by their fathersâ religious affiliation, when they were teenagers. A religious family background remains influential even when a woman has stopped attending church. The effects of religious indicators strengthen over cohorts. Moreover, the combined religious make-up of the respondentâs parents also significantly determines the progression to the third child.Sâil est bien Ă©tabli que les croyants en Europe ont plus dâenfants que les autres, le rĂŽle de la socialisation religieuse dans le contexte de la fĂ©conditĂ© contemporaine nâa pas encore Ă©tĂ© analysĂ© Ă ce jour. Cette Ă©tude sâintĂ©resse au lien entre la socialisation religieuse et la religiositĂ© actuelle, et Ă leur impact sur la probabilitĂ© dâagrandissement de deux Ă trois enfants de la descendance des femmes nĂ©erlandaises. Les donnĂ©es exploitĂ©es sont celles de la premiĂšre vague du Panel NĂ©erlandais dâEtude de la ParentĂ© (the Netherlands Kinship Panel Study, 2002â2004). A lâaide des techniques de lâanalyse des biographies, les probabilitĂ©s dâagrandissement de rang 1, rang 2 et rang 3 ont Ă©tĂ© modĂ©lisĂ©es de façon conjointe, en contrĂŽlant lâhĂ©tĂ©rogĂ©nĂ©itĂ© non observĂ©e. Les rĂ©sultats mettent en Ă©vidence lâimpact de la frĂ©quentation actuelle de lâĂ©glise par les femmes et de leur socialisation religieuse, mesurĂ©e par lâappartenance religieuse de leur pĂšre quand elles Ă©taient adolescentes. Il apparaĂźt que la religiositĂ© du contexte familial exerce une influence, mĂȘme quand la femme ne frĂ©quente plus lâĂ©glise, et que les effets des indicateurs de pratique religieuse se renforcent dâune gĂ©nĂ©ration Ă lâautre. Enfin, lâappartenance religieuse conjointe des parents de la femme dĂ©termine significativement la probabilitĂ© dâavoir un troisiĂšme enfant
Curie Point Pyrolysis Gas Chromatography
ISSN:0021-9665ISSN:1945-239
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