Double isotope-ratio thermometers: The influence of emission time scales

1999 ◽  
Vol 59 (5) ◽  
pp. 2660-2669 ◽  
Author(s):  
V. E. Viola ◽  
K. Kwiatkowski ◽  
W. A. Friedman
Keyword(s):  
Time Scales ◽  
Isotope Ratio ◽  
Emission Time ◽  
Double Isotope

A reassessment of the double isotope ratio (C-13)O/C(O-18) in molecular clouds

1989 ◽  
Vol 341 ◽  
pp. 293 ◽  
Author(s):  
David K. Taylor ◽  
R. L. Dickman
Keyword(s):  
Isotope Ratio ◽  
Molecular Clouds ◽  
O 18 ◽  
Double Isotope

Isospin independence of the H–He double isotope ratio “thermometer”

1998 ◽  
Vol 416 (1-2) ◽  
pp. 56-61 ◽  
Author(s):  
G.J Kunde ◽  
S Gaff ◽  
C.K Gelbke ◽  
T Glasmacher ◽  
M.J Huang ◽  
...  
Keyword(s):  
Isotope Ratio ◽  
Double Isotope

scholarly journals Choice of precursors for the measurement of protein turnover by the double-isotope method. Application to the study of mitochondrial proteins

1978 ◽  
Vol 176 (3) ◽  
pp. 919-926 ◽  
Author(s):  
R J Burgess ◽  
J H Walker ◽  
R J Mayer
Keyword(s):  
Solvent Extraction ◽  
Nucleic Acids ◽  
Protein Turnover ◽  
Isotope Ratio ◽  
Subcellular Fractions ◽  
Turnover Rates ◽  
Extraction Procedures ◽  
Mitochondrial Fractions ◽  
Double Isotope ◽  
Submitochondrial Fractions

1. The double-isotope concept [Arias, Doyle & Schimke (1969) J. Biol. Chem. 224, 3303–3315] for the measurement of protein turnover was used to estimate the turnover of proteins in subcellular and submitochondrial fractions prepared from rat liver. 2. Double-isotope experiments with [3H]leucine as first precursor and [14C]leucine as second precursor were used to measure the turnover rates of proteins in subcellular and submitochondrial fractions. Solvent extraction procedures designed to remove lipids and nucleic acids from trichloroacetic acid precipitates only changed the isotope ratio of the microsomal fraction. It was not possible to measure turnover of proteins in mitochondrial and submitochondrial fractions with these precursors. 3. Double-isotope experiments were designed to minimize first-precursor reutilization by employing NaH14CO3. [3H]Arginine was used as second precursor. The turnover rates of protein in subcellular and submitochondrial fractions was measured. Solvent extraction procedures designed to remove lipids and nucleic acids showed changes in the isotope ratio for all subcellular fractions, especially in microsomal and detergent-soluble mitochondrial fractions. Isotope ratios of precipitates after solvent extraction indicate that, whereas considerable heterogeneity exists for the average rates of protein turnover in subcellular fractions, little heterogeneity is observed in the average rates of protein turnover in submitochondrial fractions.

The correlation functions and emission time scales for light particles and light fragments in 40Ar+197Au reactions at 25 MeV/nucleon

1997 ◽  
Vol 620 (2) ◽  
pp. 214-228 ◽  
Author(s):  
Zhi Yong He ◽  
Li Min Duan ◽  
Gen Ming Jin ◽  
Zu Yu Li ◽  
He Yu Wu ◽  
...  
Keyword(s):  
Time Scales ◽  
Correlation Functions ◽  
Emission Time ◽  
Light Particles

Sources and emission time scales inE/A=50 MeVXe129+natCu reactions

1993 ◽  
Vol 70 (23) ◽  
pp. 3534-3537 ◽  
Author(s):  
D. R. Bowman ◽  
G. F. Peaslee ◽  
N. Carlin ◽  
R. T. de Souza ◽  
C. K. Gelbke ◽  
...  
Keyword(s):  
Time Scales ◽  
Emission Time

Nuclear temperature measurements with the double isotope ratio technique: Influence of the experimental conditions

2000 ◽  
Vol 8 (3) ◽  
pp. 355-360 ◽  
Author(s):  
P. M. Milazzo ◽  
G. Vannini ◽  
M. Bruno ◽  
N. Colonna ◽  
M. D’Agostino ◽  
...  
Keyword(s):  
Isotope Ratio ◽  
Temperature Measurements ◽  
Experimental Conditions ◽  
Nuclear Temperature ◽  
Double Isotope

scholarly journals An uncertainty principle for star formation – V. The influence of dust extinction on star formation rate tracer lifetimes and the inferred molecular cloud lifecycle

2020 ◽  
Vol 497 (4) ◽  
pp. 5076-5089
Author(s):  
Daniel T Haydon ◽  
Yusuke Fujimoto ◽  
Mélanie Chevance ◽  
J M Diederik Kruijssen ◽  
Mark R Krumholz ◽  
...  
Keyword(s):  
Star Formation ◽  
Time Scales ◽  
Molecular Cloud ◽  
Column Density ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Disc Galaxy ◽  
Dust Extinction ◽  
Stellar Feedback ◽  
Emission Time

ABSTRACT Recent observational studies aiming to quantify the molecular cloud lifecycle require the use of known ‘reference time-scales’ to turn the relative durations of different phases of the star formation process into absolute time-scales. We previously constrained the characteristic emission time-scales of different star formation rate (SFR) tracers, as a function of the SFR surface density and metallicity. However, we omitted the effects of dust extinction. Here, we extend our suite of SFR tracer emission time-scales by accounting for extinction, using synthetic emission maps of a high-resolution hydrodynamical simulation of an isolated, Milky Way-like disc galaxy. The stellar feedback included in the simulation is inefficient compared to observations, implying that it represents a limiting case in which the duration of embedded star formation (and the corresponding effect of extinction) is overestimated. Across our experiments, we find that extinction mostly decreases the SFR tracer emission time-scale, changing the time-scales by factors of 0.04–1.74, depending on the gas column density. UV filters are more strongly affected than H α filters. We provide the limiting correction factors as a function of the gas column density and flux sensitivity limit for a wide variety of SFR tracers. Applying these factors to observational characterizations of the molecular cloud lifecycle produces changes that broadly fall within the quoted uncertainties, except at high kpc-scale gas surface densities ($\Sigma _{\rm g}\gtrsim 20~{\mathrm{M_{\odot }\, pc^{-2}}}$). Under those conditions, correcting for extinction may decrease the measured molecular cloud lifetimes and feedback time-scales, which further strengthens previous conclusions that molecular clouds live for a dynamical time and are dispersed by early, pre-supernova feedback.

Emission time scales for light charged particles from symmetric and asymmetric fission processes for40Ar+197Aureactions at 25 MeV/nucleon

1998 ◽  
Vol 57 (4) ◽  
pp. 1824-1831 ◽  
Author(s):  
Zhi Yong He ◽  
Gen Ming Jin ◽  
Zu Yu Li ◽  
Li Min Duan ◽  
Guang Xi Dai ◽  
...  
Keyword(s):  
Time Scales ◽  
Charged Particles ◽  
Emission Time ◽  
Light Charged Particles ◽  
Asymmetric Fission
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