294,712 research outputs found
Technique for analyzing human respiratory process
Electronic system /MIRACLE 2/ places frequency and gas flow rate of the respiratory process within a common frame of reference to render them comparable and compatible with ''real clock time.'' Numerous measurements are accomplished accurately on a strict one-minute half-minute, breath-by-breath, or other period basis
Respiratory analysis system and method
A system is described for monitoring the respiratory process in which the gas flow rate and the frequency of respiration and expiration cycles can be determined on a real time basis. A face mask is provided with one-way inlet and outlet valves where the gas flow is through independent flowmeters and through a mass spectrometer. The opening and closing of a valve operates an electrical switch, and the combination of the two switches produces a low frequency electrical signal of the respiratory inhalation and exhalation cycles. During the time a switch is operated, the corresponsing flowmeter produces electric pulses representative of the flow rate; the electrical pulses being at a higher frequency than that of the breathing cycle and combined with the low frequency signal. The high frequency pulses are supplied to conventional analyzer computer which also receives temperature and pressure inputs and computes mass flow rate and totalized mass flow of gas. From the mass spectrometer, components of the gas are separately computed as to flow rate. The electrical switches cause operation of up-down inputs of a reversible counter. The respective up and down cycles can be individually monitored and combined for various respiratory measurements
The long-term optical behavior of MRK421
All data available in B band for the BL Lac object MRK421 from 22
publications are used to construct a historical light curve, dating back to
1900. It is found that the light curve is very complicated and consists of a
set of outbursts with very large duration. The brightness of MRK421 varies from
11.6 magnitude to more than 16 magnitude. Analyses with Jurkevich method of
computing period of cyclic phenomena reveal in the light curve two kinds of
behaviors. The first one is non-periodic with rapid, violent variations in
intensity on time scales of hours to days. The second one is periodic with a
possible period of years. Another possible period of years is not very significant. We have tested the robustness of the
Jurkevich method. The period of about one year found in the light curves of
MRK421 and of other objects is a spurious period due to the method and the
observing window. We try to explain the period of years under the
thermal instability of a slim accretion disk around a massive black hole of
mass of .Comment: Tex, 14 pages, 5 Postscript figures. Accepted for publication in A&A
Supplement Serie
X-shaped radio galaxies as observational evidence for the interaction of supermassive binary black holes and accretion disk at pc scale
A supermassive black hole binary may form during galaxy mergering. we
investigate the interaction of the supermassive binary black holes (SMBBHs) and
an accretion disk and show that the detected X-shaped structure in some FRII
radio galaxies may be due to the interaction-realignment of inclined binary and
accretion disk occurred within the pc scale of the galaxy center. We compare in
detail the model and observations and show that the configuration is consistent
very well with the observations of X-shaped radio sources. X-shaped radio
feature form only in FRII radio sources due to the strong interaction between
the binary and a standard disk, while the absence of X-shaped FRI radio
galaxies is due to that the interaction between the binary and the radiatively
inefficient accretion flow in FRI radio sources is negligible. It is suggested
that the binary would keep misaligned with the outer disk for most of the life
time of FRII radio galaxies and the orientation of jet in most FRII radio
galaxies distributes randomly, while the jets in most FRI radio galaxies is
expected to be vertical to the accretion disk and thus the major axis of host
galaxy. We discuss the relationship of X-shaped and double-double radio
galaxies (DDRGs). The model is applied in paticular to two X-shaped radio
sources 4C+01.30 and 3C293 and one DDRG source J0116-473 and show that the
SMBBHs in the three objects have black hole mass ratios .Comment: 35 pages, no figure, no table. Accepted for publication in MNRA
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