1,051 research outputs found
Gas Density and the Volume Schmidt Law for Spiral Galaxies
The thickness of the equilibrium isothermal gaseous layers and their volume
densities \rho_{gas}(R) in the disc midplane are calculated for 7 spiral
galaxies (including our Galaxy) in the frame of self-consistent axisymmetric
model. Local velocity dispersions of stellar discs were assumed to be close to
marginal values necessary for the discs to be in a stable equilibrium state.
Under this condition the stellar discs of at least 5 of 7 galaxies reveal a
flaring. Their volume densities decrease with R faster than \rho_{gas}, and, as
a result, the gas dominates by the density at the disc periphery. Comparison of
the azimuthally averaged star formation rate SFR with the gas density shows
that there is no universal Schmidt law SFR \rho_{gas}^n, common to all
galaxies. Nevertheless, SFR in different galaxies reveals better correlation
with the volume gas density than with the column one. Parameter n in the
Schmidt law SFR \rho_{gas}^n, formally calculated by the least square method,
lies within 0.8-2.4 range and it's mean value is close to 1.5. Values of n
calculated for molecular gas only are characterized by large dispersion, but
their mean value is close to 1. Hence the smaller \rho_{gas} the less is a
fraction of gas actively taking part in the process of star formation.Comment: 24 pages, 11 figures, to be published in Astronomy Reports, 200
Midplane Gas Density and the Schmidt Law
The thickness of isothermal gaseous layers and their midplane volume
densities \rho_{gas}(R) were calculated for several spiral and LSB galaxies by
solving the self-consistent equilibrium equations for gaseous discs embedded
into a stellar one. The self-gravity of the gas and influence of dark halo on
the disk thickness were taken into account. The resulting midplane volume
densities of spiral galaxies were compared with the azimuthally averaged star
formation rate SFR to verify the feasibility and universality of the Schmidt
law SFR ~ \rho_{gas}^n.Comment: 2 pages, 2 figures, proceeding of the poster presented at the Vatican
Conf. "Formation and evolution of galaxy disks" held in Rome, 1-5 Oct. 200
Reversible metaphorical models βmechanism is a manβ and βman is a mechanismβ: productivity of the model as an aspect of functional asymmetry
NMR β SPECTROSCOPY TECHNIQUE FOR SALMON FISH SPECIES QUALITY ASSESSMENT
NMR-spectroscopy was used for development of the criteria which characterize the chilled and frozen fish quality. It has been shown that 1H-NMR experiments can be used as quality factor to measure the concentration of inosine, hypoxanthine and inosine-5β-monophosphate generated during the fish storage. The quality factor is expressed by the K1 correlates well with the sensory quality of chilled Atlantic salmon (Salmo Salar), whereas, quality factor H is more sensitive for measuring the quality characteristics of frozen pink salmon (Oncorhynchus gorbuscha), chum salmon (Oncorhynchus keta), sockeye salmon (Oncorhynchus nerka).NMR-spectroscopy was used for development of the criteria which characterize the chilled and frozen fish quality. It has been shown that 1H-NMR experiments can be used as quality factor to measure the concentration of inosine, hypoxanthine and inosine-5β-monophosphate generated during the fish storage. The quality factor is expressed by the K1 correlates well with the sensory quality of chilled Atlantic salmon (Salmo Salar), whereas, quality factor H is more sensitive for measuring the quality characteristics of frozen pink salmon (Oncorhynchus gorbuscha), chum salmon (Oncorhynchus keta), sockeye salmon (Oncorhynchus nerka)
Development of the concept language in the minds of pupils: analysis of school textbooks
Knowledge of a person about the world make a system of concepts, while language is coding of the language world picture by language means. Conceptual approach stimulates development of a more detailed world picture in the mind of a person. The Russian language takes an important place in the system of education. Analysis of the concept βlanguageβ in school textbooks revealed both positive and negative features.ΠΠ½Π°Π½ΠΈΡ ΡΠ΅Π»ΠΎΠ²Π΅ΠΊΠ° ΠΎ ΠΌΠΈΡΠ΅ ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»ΡΡΡ ΡΠΎΠ±ΠΎΠΉ ΡΠΈΡΡΠ΅ΠΌΡ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½Π½ΡΡ
ΠΊΠΎΠ½ΡΠ΅ΠΏΡΠΎΠ², Π° ΡΠ·ΡΠΊ β ΡΡΠΎ ΠΊΠΎΠ΄ΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ ΡΠ·ΡΠΊΠΎΠ²ΡΠΌΠΈ ΡΡΠ΅Π΄ΡΡΠ²Π°ΠΌΠΈ ΠΊΠ°ΡΡΠΈΠ½Ρ ΠΌΠΈΡΠ°. ΠΠΎΡΡΠΎΠΌΡ ΠΊΠΎΠ½ΡΠ΅ΠΏΡΡΠ°Π»ΡΠ½ΡΠΉ ΠΏΠΎΠ΄Ρ
ΠΎΠ΄ ΡΠΏΠΎΡΠΎΠ±ΡΡΠ²ΡΠ΅Ρ ΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΡ Π½Π°ΠΈΠ±ΠΎΠ»Π΅Π΅ ΠΏΠΎΠ»Π½ΠΎΠΉ ΠΊΠ°ΡΡΠΈΠ½Ρ ΠΌΠΈΡΠ° Π² ΡΠ·ΡΠΊΠΎΠ²ΠΎΠΌ ΡΠΎΠ·Π½Π°Π½ΠΈΠΈ ΠΈ ΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΈΡ ΠΈΠ½Π΄ΠΈΠ²ΠΈΠ΄Π° ΠΊΠ°ΠΊ Π»ΠΈΡΠ½ΠΎΡΡΠΈ. Π’Π°ΠΊΠΈΠΌ ΠΎΠ±ΡΠ°Π·ΠΎΠΌ, ΡΡΡΡΠΊΠΈΠΉ ΡΠ·ΡΠΊ Π² ΡΠΈΡΡΠ΅ΠΌΠ΅ ΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΡ Π·Π°Π½ΠΈΠΌΠ°Π΅Ρ ΠΎΡΠΎΠ±ΠΎΠ΅ ΠΌΠ΅ΡΡΠΎ. ΠΠ½Π°Π»ΠΈΠ· ΠΊΠΎΠ½ΡΠ΅ΠΏΡΠ° Β«ΡΠ·ΡΠΊΒ» Π² ΡΠΊΠΎΠ»ΡΠ½ΡΡ
ΡΡΠ΅Π±Π½ΠΈΠΊΠ°Ρ
Π²ΡΡΠ²ΠΈΠ» ΠΊΠ°ΠΊ ΠΏΠΎΠ»ΠΎΠΆΠΈΡΠ΅Π»ΡΠ½ΡΠ΅, ΡΠ°ΠΊ ΠΈ ΠΎΡΡΠΈΡΠ°ΡΠ΅Π»ΡΠ½ΡΠ΅ ΠΌΠΎΠΌΠ΅Π½ΡΡ
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