The determination of fission time scales from excitation function data

1990 ◽  
Vol 247 (2-3) ◽  
pp. 242-245 ◽  
Author(s):  
J.B. Natowitz ◽  
M. Gonin ◽  
M. Gui ◽  
K. Hagel ◽  
Y. Lou ◽  
...  
Keyword(s):  
Excitation Function ◽  
Time Scales ◽  
Function Data

scholarly journals Hydrological response to different time scales of climatological drought: an evaluation of the Standardized Precipitation Index in a mountainous Mediterranean basin

2005 ◽  
Vol 9 (5) ◽  
pp. 523-533 ◽  
Author(s):  
S. M. Vicente-Serrano ◽  
J. I. López-Moreno
Keyword(s):  
Time Scales ◽  
Hydrological Cycle ◽  
Standardized Precipitation Index ◽  
Precipitation Index ◽  
Drought Indices ◽  
Long Time ◽  
The Standardized Precipitation Index ◽  
Hydrological Droughts ◽  
Different Time Scales

Abstract. At present, the Standardized Precipitation Index (SPI) is the most widely used drought index to provide good estimations about the intensity, magnitude and spatial extent of droughts. The main advantage of the SPI in comparison with other indices is the fact that the SPI enables both determination of drought conditions at different time scales and monitoring of different drought types. It is widely accepted that SPI time scales affect different sub-systems in the hydrological cycle due to the fact that the response of the different water usable sources to precipitation shortages can be very different. The long time scales of SPI are related to hydrological droughts (river flows and reservoir storages). Nevertheless, few analyses empirically verify these statements or the usefulness of the SPI time scales to monitor drought. In this paper, the SPI at different time scales is compared with surface hydrological variables in a big closed basin located in the central Spanish Pyrenees. We provide evidence about the way in which the longer (>12 months) SPI time scales may not be useful for drought quantification in this area. In general, the surface flows respond to short SPI time scales whereas the reservoir storages respond to longer time scales (7–10 months). Nevertheless, important seasonal differences can be identified in the SPI-usable water sources relationships. This suggests that it is necessary to test the drought indices and time scales in relation to their usefulness for monitoring different drought types under different environmental conditions and water demand situations.

scholarly journals Experiment-based determination of the excitation function for the production of Ti44 in proton-irradiated vanadium samples

2021 ◽  
Vol 104 (1) ◽  
Author(s):  
M. Veicht ◽  
I. Kajan ◽  
J.-C. David ◽  
S. Chen ◽  
E. Strub ◽  
...  
Keyword(s):  
Excitation Function

Determination of the reference range of platelet aggregation using a new automatic coagulation analyzer and visualization of platelet function data

2020 ◽  
Vol 194 ◽  
pp. 95-97
Author(s):  
Makiko Yoshida ◽  
Kazumasa Oura ◽  
Mie Shimizu ◽  
Tatsunori Natori ◽  
Shinsuke Narumi ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Platelet Function ◽  
Reference Range ◽  
Function Data ◽  
Coagulation Analyzer

A hybrid model description of 13C(p,γ)14N capture reaction

2019 ◽  
Vol 28 (06) ◽  
pp. 1950038 ◽  
Author(s):  
Suprita Chakraborty ◽  
Avijit Mukherjee ◽  
Subinit Roy
Keyword(s):  
Excitation Function ◽  
Hybrid Model ◽  
Cross Sections ◽  
Bound State ◽  
Relative Energy ◽  
Model Description ◽  
Broad Resonance ◽  
Capture Reaction ◽  
Function Data ◽  
The Cross

The radiative capture reaction [Formula: see text] is analyzed using a hybrid model approach where the non-resonant component has been constructed employing the potential model with a folded M3Y potential. The one-level Breit–Wigner formula has been used to estimate the cross-sections of the resonant decays of dominant ([Formula: see text]) state of [Formula: see text]N at 8.06[Formula: see text]MeV. The contribution of the broad resonance at 8.77[Formula: see text]MeV ([Formula: see text]) has been dealt with differently. While Breit–Wigner formula has been used where the excitation function data exist, the [Formula: see text]-matrix prediction for the cross-section of decay to a bound state of [Formula: see text]N from the broad resonance has been used where excitation function data are not available. The single particle spectroscopic factors for ground and six excited states of [Formula: see text]N have been obtained from the fits. The resulting astrophysical [Formula: see text]-factor at zero relative energy is [Formula: see text][Formula: see text]keV b. The value is in good agreement with the previously reported [Formula: see text]-matrix result and also consistent within error bars with the published values.

scholarly journals Type II Supernova Photospheres and the Distance to Supernova 1987A

1988 ◽  
Vol 108 ◽  
pp. 295-304
Author(s):  
Manorama Chilukuri ◽  
Robert V. Wagoner
Keyword(s):  
Time Scales ◽  
Direct Determination ◽  
Type Ii ◽  
Physical Conditions ◽  
Supernova 1987A ◽  
Spectral Flux ◽  
Spectrophotometric Data ◽  
Parallel Geometry ◽  
The Many

Among the many historic opportunities provided by the recent supernova in the LMC is that to improve our understanding of the physical conditions in the neighborhood of supernova photospheres, even though 1987A was initially characterized by radial and time scales smaller (by a factor 5–10) than “standard” more luminous SNII. Two consequences of this understanding, which we shall focus on in this contribution, are (a) an estimate of the (frequency-dependent) location and thickness of the photosphere and (b) the only direct determination of the distance of the supernova (via the generalized Baade method). We find that the photosphere is sharp enough to allow the use of plane-parallel geometry in the calculation of the emergent continuum spectral flux, if we confine our attention to those epochs (temperature T ~ 5000−6000 K) at which hydrogen is recombining at the photosphere. We also find that the distance to this supernova is 43 ± 4 kpc. The reliability of this determination should improve when accurate spectrophotometric data for dates other than March 1 become available to us.

scholarly journals Determination of LC and LB

1995 ◽  
Vol 10 ◽  
pp. 205-205
Author(s):  
T. Fukushima
Keyword(s):  
Time Scales ◽  
Full Paper ◽  
Numerical Integrations ◽  
Best Estimate ◽  
Analytical Formulas ◽  
The Mean ◽  
The Difference ◽  
Scale Difference ◽  
Astronomical Constants

The location-independent part of TCB-TCG, the difference between the two new time scales adopted by the IAU (1992), was integrated numerically for three JPL planetary/lunar ephemerides; DE102, DE200, and DE245. The differences among these three integrations were mostly explained by the difference in the adopted constants of the ephemerides. It was shown that the post-Newtonian correction and the perturbation by asteroids are negligible except for the mean rate, LC. The comparison of these numerical integrations with the analytical formulas of Hirayama et al. (1987) and Fairhead and Bretagnon (1990) as well as their extended versions lead to the best estimate of LC asCombining this with the recent value of the geoid potential in Bursa et al. (1992), we estimated the value of LB, the scale difference between TCB and TT, asTable I summarizes these conclusions. These estimates of LC and LB are more reliable than the former values we gave (Fukushima et al. 1986). The new estimate of LB will be useful in converting the numerical values of some precisely determined astronomical constants such as AU measured in meter from those in TDB to those in TCB. Also the numerically integrated TCB-TCG, which are to be called Time Ephemeris, will be useful when converting between TCB and TDB, i.e. the time scales themselves. The full paper will be appeared in A & A with the title of Time Ephemeris.

Determination of the excitation function for the reaction T(d, n) He4

Atomic Energy ◽  
1957 ◽  
Vol 2 (4) ◽  
pp. 474-476 ◽  
Author(s):  
V. A. Davidenko ◽  
I. S. Pogrebov ◽  
A. I. Saukov
Keyword(s):  
Excitation Function
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