Hydrogen Molecules in the Planetary Nebula NGC6302

2006 ◽  
pp. 423-426
Author(s):  
Mikako Matsuura ◽  
Albert A. Zijlstra
Keyword(s):  
Planetary Nebula ◽  
Hydrogen Molecules

Effects of Cooking Processes on Breath Hydrogen and Colonic Fermentation of Soybean

2020 ◽  
Vol 16 (4) ◽  
pp. 488-493
Author(s):  
Naoya Okumura ◽  
Naoya Jinno ◽  
Kentaro Taniguchi ◽  
Kenichi Tanabe ◽  
Sadako Nakamura ◽  
...  
Keyword(s):  
Healthy Adult ◽  
Area Under The Curve ◽  
Cooking Methods ◽  
Breath Hydrogen ◽  
Gas Chromatograph ◽  
Colonic Fermentation ◽  
Hydrogen Molecules ◽  
Nutritional Analysis ◽  
Hydrogen Level ◽  
Adult Volunteers

Background: Soybean is rich in dietary fibers; consequently, soybean ingestion considerably increases the breath level of hydrogen molecules via anaerobic colonic fermentation. However, the influence of cooking methods on this effect, which can affect the overall health benefits of soybean, remains unknown. Objectives: The aim is to examine whether different methods of cooking soybean affect the colonic fermentation process. Methods: Nine healthy adult volunteers participated in the study; they ingested either roasted soybean flour (kinako) or well-boiled soybean (BS). Differences in their breath components were compared. Both test meals were cooked using 80 g of soybeans per individual. After a 12 h fast, the participants ate the test meals, and their breath hydrogen level was analyzed every 1 h for 9 h by using a gas chromatograph with a semiconductor detector. In addition, particle size distribution and soluble/ insoluble fibers in the feces were examined. Results: The oro-cecal transit time did not significantly differ between individuals who ingested kinako and BS. However, the area under the curve between 7 and 9 h after the ingestion of BS was significantly increased compared with that after the ingestion of kinako. The nutritional analysis indicated that the content of both soluble and insoluble fibers in BS was higher than that in kinako. In addition, the levels of unfermented fragments and soluble/insoluble fibers in the feces were increased after the ingestion of kinako compared with those after the ingestion of kinako. Conclusion: Cooking methods alter the composition of non-digestible fibers in soybean, and this can result in the lack of fermentative particles in the feces, thereby causing alterations in the breath level of hydrogen via colonic fermentation.

Coupled-pair theories and Davidson-type corrections for quasidegenerate states: The H4 model revisited

1988 ◽  
Vol 53 (9) ◽  
pp. 1919-1942 ◽  
Author(s):  
Josef Paldus ◽  
Paul E. S. Wormer ◽  
Marc Benard
Keyword(s):  
Electron Correlation ◽  
Model System ◽  
Coupled Cluster ◽  
Electron Model ◽  
Hydrogen Molecules ◽  
Double Zeta ◽  
Correlation Problem ◽  
Variational Approaches ◽  
Cluster Type ◽  
The Many

The performance of various variational and non-variational approaches to the many-electron correlation problem is examined for a simple four-electron model system consisting of two stretched hydrogen molecules in trapezoidal, rectangular and linear configurations, in which the degree of quasi-degeneracy can be continuously varied from a non-degenerate to an almost degenerate situation. In contrast to an earlier work (K. Jankowski and J. Paldus, Int. J. Quantum Chem. 18, 1243 (1980)) we employ a double-zeta plus polarization basis and examine both single reference and multireference configuration interaction and coupled-cluster-type approaches. The performance of various Davidson-type corrections is also investigated.

Angular Expansion Measurement of the Young and Compact Planetary Nebula V[CLC]y[/CLC] 2-2

1998 ◽  
Vol 115 (6) ◽  
pp. 2466-2474 ◽  
Author(s):  
Haryadi Christianto ◽  
E. R. Seaquist
Keyword(s):  
Planetary Nebula ◽  
Angular Expansion

High‐Resolution X‐Ray Image of the Hydrogen‐deficient Planetary Nebula Abell 30

1997 ◽  
Vol 482 (2) ◽  
pp. 891-896 ◽  
Author(s):  
You‐Hua Chu ◽  
Thomas H. Chang ◽  
Gail M. Conway
Keyword(s):  
High Resolution ◽  
Planetary Nebula ◽  
X Ray

The Kinematics and Excitation of Molecular Hydrogen Emission in the Planetary Nebula BD +30o3639

1998 ◽  
Vol 498 (1) ◽  
pp. 267-277 ◽  
Author(s):  
D. L. Shupe ◽  
J. E. Larkin ◽  
R. A. Knop ◽  
L. Armus ◽  
K. Matthews ◽  
...  
Keyword(s):  
Planetary Nebula ◽  
Molecular Hydrogen ◽  
Hydrogen Emission

The High‐Excitation Planetary Nebula NGC 7662

1997 ◽  
Vol 491 (1) ◽  
pp. 242-253 ◽  
Author(s):  
Siek Hyung ◽  
Lawrence H. Aller
Keyword(s):  
Planetary Nebula ◽  
High Excitation ◽  
Ngc 7662

The Structure and Dynamics of the Proto–Planetary Nebula M1‐92

1998 ◽  
Vol 504 (2) ◽  
pp. 915-920 ◽  
Author(s):  
V. Bujarrabal ◽  
J. Alcolea ◽  
R. Neri
Keyword(s):  
Planetary Nebula ◽  
Structure And Dynamics

scholarly journals Planetary Nebulae in M31: Abundances, and comparison with bright Planetary Nebulae in the LMC

1997 ◽  
Vol 180 ◽  
pp. 475-476
Author(s):  
M. G. Richer ◽  
G. Stasińska ◽  
M. L. McCall
Keyword(s):  
Planetary Nebula ◽  
Luminosity Function ◽  
Large Population ◽  
Wavelength Region ◽  
Planetary Nebulae ◽  
Surprising Result ◽  
Population Synthesis ◽  
Abundance Distribution ◽  
Wide Range ◽  
The Mean

We have obtained spectra of 28 planetary nebulae in the bulge of M31 using the MOS spectrograph at the Canada-France-Hawaii Telescope. Typically, we observed the [O II] λ3727 to He I λ5876 wavelength region at a resolution of approximately 1.6 å/pixel. For 19 of the 21 planetary nebulae whose [OIII]λ5007 luminosities are within 1 mag of the peak of the planetary nebula luminosity function, our oxygen abundances are based upon a measured [OIII]λ4363 intensity, so they are based upon a measured electron temperature. The oxygen abundances cover a wide range, 7.85 dex < 12 + log(O/H) < 9.09 dex, but the mean abundance is surprisingly low, 12 + log(O/H)–8.64 ± 0.32 dex, i.e., roughly half the solar value (Anders & Grevesse 1989). The distribution of oxygen abundances is shown in Figure 1, where the ordinate indicates the number of planetary nebulae with abundances within ±0.1 dex of any point on the x-axis. The dashed line indicates the mean abundance, and the dotted lines indicate the ±1 σ points. The shape of this abundance distribution seems to indicate that the bulge of M31 does not contain a large population of bright, oxygen-rich planetary nebulae. This is a surprising result, for various population synthesis studies (e.g., Bica et al. 1990) have found a mean stellar metallicity approximately 0.2 dex above solar. This 0.5 dex discrepancy leads one to question whether the mean stellar metallicity is as high as the population synthesis results indicate or if such metal-rich stars produce bright planetary nebulae at all. This could be a clue concerning the mechanism responsible for the variation in the number of bright planetary nebulae observed per unit luminosity in different galaxies (e.g., Hui et al. 1993).

Sign in / Sign up

Export Citation Format

Share Document