Determination of Tissue, Airway and Total Resistance to Respiration in Cats

1956 ◽  
Vol 9 (2) ◽  
pp. 213-218 ◽  
Author(s):  
Alfred W. Brody ◽  
Arthur B. DuBois
Keyword(s):  
Total Resistance ◽  
Resistance To Respiration

Respiratory impedance and volume flow at high frequency in dogs

1961 ◽  
Vol 16 (3) ◽  
pp. 439-443 ◽  
Author(s):  
Wayland Elroy Hull ◽  
Ernest Croft Long
Keyword(s):  
High Frequency ◽  
Damping Ratio ◽  
Simultaneous Recording ◽  
Volume Flow ◽  
Total Resistance ◽  
Respiratory Impedance ◽  
Static Compliance ◽  
Tissue Resistance ◽  
Zero Phase

Sinusoidal forcing at frequencies up to 11 cycle/sec was applied to the anesthetized, apneic dog in a body respirator. Using an oscilloscope and the Lissajous patterns displayed by the simultaneous recording of driving pressure and volume flow, the frequency (resonant; mean, 5.4 cycle/sec) at which there was zero phase shift was determined. By analogy with an inductance-resistance-capacitance network, inertance (mean, .041 cm H2O/liter/sec2) was derived from static compliance (mean, .022 liter/cm H2O) and resonant frequency. Impedance at each frequency and damping ratio (mean, 1.57) was calculated. Tissue resistance was found to be 19% of the total resistance (mean, 4.3 cm H2O/liter/sec). A nomogram was constructed to facilitate the determination of inertance and the coding of data as electrical analogues. Submitted on September 16, 1960

scholarly journals Methods of Determination of Frictional Resistance for Prediction of Total Resistance of Inland Waterway Vessels

2018 ◽  
Vol 25 (s1) ◽  
pp. 68-73
Author(s):  
Jan Kulczyk
Keyword(s):  
Form Factor ◽  
Model Test ◽  
Water Depth ◽  
Frictional Resistance ◽  
Resistance Coefficient ◽  
Total Resistance ◽  
Inland Waterway ◽  
Correlation Line ◽  
Limited Depth

Abstract In the present paper presented are the results of prediction of total resistance of inland waterway vessels based on model test data. In scaling the resistance from model to full scale the extrapolation with two-dimensional frictional resistance formulation (without form factor) was applied, combined with different methods of determination of frictional (viscous) resistance coefficient. There were used the equations that include the effect of water depth, with and without account for pressure gradient. It was shown that limited depth of water substantially affects the frictional resistance. The results of example calculations are compared to resistance prediction made using the ITTC 1957 model-ship correlation line. Example calculations take into account the limited depth of water. Depending on the applied method of determination of frictional resistance coefficient the resultant total resistance of inland waterway vessel is higher or lower than the resistance based on the ITTC 1957 correlation line. The effect of water depth depends on the ratio of water depth to ship draught (h/T), on ship speed, and on the composition of a convoy. The extrapolation of resistance was made without including the form factor. Computations are made based on model test data for an inland waterway cargo vessel, for a kombi-type convoy of an inland waterway cargo vessel and a dumb barge, and for a convoy of two dumb barges without a pushboat.

Influence of abdominal muscles, mesenteric viscera and liver on respiratory mechanics

1959 ◽  
Vol 14 (1) ◽  
pp. 121-128 ◽  
Author(s):  
Alfred W. Brody ◽  
John J. Connolly ◽  
Harry J. Wander
Keyword(s):  
Natural Frequency ◽  
Abdominal Muscles ◽  
Damping Factor ◽  
Total Resistance ◽  
Abdominal Incision ◽  
Tissue Resistance ◽  
Residual Capacity ◽  
Mass Factor ◽  
Steady Force ◽  
Resistance To Respiration

In a group of 13 supine, anesthetized cats initial measurement was made of respiratory elastance, total resistance by sinusoidal pressure, total resistance, k1 and k2 and their ratio of change from breath to breath, the natural frequency, damping factor and mass factor or inertance, and the functional residual capacity (FRC) and tissue resistance. Comparison was then made with the value obtained by remeasurement in the same cat after a) control operation of mid-line abdominal incision; b) incisions eliminating the effects of the abdominal muscles (mid-line vertical plus transverse incision extended to back); c) evisceration of gastrointestinal tract and spleen and d) evisceration plus hepatectomy. The abdominal response was found to be mainly a surface wave response (at a speed of about 150 cm/sec.) above the natural frequency. The abdominal muscles impose a steady force, more like a weight than a spring, which decreases the FRC. The liver contributes significantly to the mass factor and natural frequency, but the viscera do not. About half the tissue resistance consists of a resistance within the abdomen to respiratory movements; since nearly half the total resistance is tissue resistance, this is nearly one fourth the total resistance to respiration. Submitted on June 2, 1958

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

Distance to SN 1987A and the LMC

1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia
Keyword(s):  
Angular Size ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Distance Modulus ◽  
Absolute Size ◽  
Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

International determination of the total motion of the pole

1961 ◽  
Vol 13 ◽  
pp. 29-41
Author(s):  
Wm. Markowitz
Keyword(s):  
Secular Motion ◽  
The Future

A symposium on the future of the International Latitude Service (I. L. S.) is to be held in Helsinki in July 1960. My report for the symposium consists of two parts. Part I, denoded (Mk I) was published [1] earlier in 1960 under the title “Latitude and Longitude, and the Secular Motion of the Pole”. Part II is the present paper, denoded (Mk II).

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

Large-scale Motion of Solar Filaments

2000 ◽  
Vol 179 ◽  
pp. 205-208
Author(s):  
Pavel Ambrož ◽  
Alfred Schroll
Keyword(s):  
Magnetic Flux ◽  
Proper Motion ◽  
Time Scale ◽  
Large Scale ◽  
Accuracy Of Measurements ◽  
Solar Filaments ◽  
General Movement ◽  
Scale Motion ◽  
Velocity Scatter

AbstractPrecise measurements of heliographic position of solar filaments were used for determination of the proper motion of solar filaments on the time-scale of days. The filaments have a tendency to make a shaking or waving of the external structure and to make a general movement of whole filament body, coinciding with the transport of the magnetic flux in the photosphere. The velocity scatter of individual measured points is about one order higher than the accuracy of measurements.

Practical Realization of a Reference System for Earth Dynamics by Satellite Methods

1975 ◽  
Vol 26 ◽  
pp. 341-380 ◽  
Author(s):  
R. J. Anderle ◽  
M. C. Tanenbaum
Keyword(s):  
Reference Frame ◽  
Polar Motion ◽  
Pole Position ◽  
Control Points ◽  
Significant Information ◽  
Crustal Motion ◽  
Average Reference ◽  
Future Data ◽  
Existing Data

AbstractObservations of artificial earth satellites provide a means of establishing an.origin, orientation, scale and control points for a coordinate system. Neither existing data nor future data are likely to provide significant information on the .001 angle between the axis of angular momentum and axis of rotation. Existing data have provided data to about .01 accuracy on the pole position and to possibly a meter on the origin of the system and for control points. The longitude origin is essentially arbitrary. While these accuracies permit acquisition of useful data on tides and polar motion through dynamio analyses, they are inadequate for determination of crustal motion or significant improvement in polar motion. The limitations arise from gravity, drag and radiation forces on the satellites as well as from instrument errors. Improvements in laser equipment and the launch of the dense LAGEOS satellite in an orbit high enough to suppress significant gravity and drag errors will permit determination of crustal motion and more accurate, higher frequency, polar motion. However, the reference frame for the results is likely to be an average reference frame defined by the observing stations, resulting in significant corrections to be determined for effects of changes in station configuration and data losses.

Sign in / Sign up

Export Citation Format

Share Document