Assessment of CO2 Responsiveness by Maximum Rate of Change of Mouth Pressure during Initial Transient Inspiratory Obstruction

1974 ◽  
Vol 46 (2) ◽  
pp. 19P-19P
Author(s):  
A. W. Matthews ◽  
J. B. L. Howell
Keyword(s):  
Maximum Rate ◽  
Rate Of Change ◽  
Initial Transient ◽  
Mouth Pressure

Filtration by superficial and deep glomeruli of normovolemic and volume-depleted rats

1986 ◽  
Vol 250 (1) ◽  
pp. F86-F91
Author(s):  
R. V. Pinnick ◽  
V. J. Savin
Keyword(s):  
Basement Membrane ◽  
Maximum Rate ◽  
Rate Of Change ◽  
The Other ◽  
Membrane Area ◽  
Morphometric Analyses ◽  
Three Samples ◽  
Glomerular Size ◽  
Glomerular Ultrafiltration

We measured glomerular ultrafiltration coefficient (Kf) of isolated superficial (S) and deep (D) glomeruli of normovolemic and volume-depleted rats. Filtration was induced in vitro, and Kf was calculated from the maximum rate of change in glomerular size. Basement membrane area (A) for each glomerulus was estimated from morphometric analyses, and glomerular capillary hydraulic conductivity (Lp) was calculated by the formula Lp = Kf/A. Kf of S and D glomeruli of normovolemic rats were 2.98 +/- 0.98 and 4.25 +/- 0.07 nl . min-1 . mmHg-1, respectively. In hypovolemic rats, Kf of S glomeruli fell by approximately 50% to 1.52 +/- 0.14 nl . min-1 . mmHg-1 (P less than 0.001), whereas Kf of D glomeruli remained unchanged at 4.28 +/- 0.10 nl . min-1 . mmHg-1. Lp, calculated using the peripheral capillary area, averaged 1.98 +/- 0.09 and 1.98 +/- 0.06 microliter . min-1 . mmHg-1 . cm-2 in S and D glomeruli of normovolemic rats and 1.89 +/- 0.11 microliter . min-1 . mmHg-1 . cm-2 in D glomeruli of hypovolemic rats. Lp of S glomeruli of volume-depleted rats (0.90 +/- 0.03 microliter . min-1 . mmHg-1 . cm-2) was lower than in any of the other three samples. Mild hypovolemia causes the Kf of S glomeruli to decline, whereas Kf of D glomeruli remains constant. The decrease in Kf occurs without an alteration in capillary area and is most likely due to a decrease in Lp.

scholarly journals Динамическое управление мощностью мегаваттного электронного пучка субмиллисекудной длительности в источнике с плазменным катодом

2021 ◽  
Vol 47 (10) ◽  
pp. 38
Author(s):  
М.С. Воробьёв ◽  
П.В. Москвин ◽  
В.И. Шин ◽  
Н.Н. Коваль ◽  
К.Т. Ашурова ◽  
...  
Keyword(s):  
Electron Beam ◽  
Beam Energy ◽  
Maximum Rate ◽  
Control Method ◽  
Beam Current ◽  
Rate Of Change ◽  
Beam Power ◽  
Metallic Materials ◽  
Plasma Cathode ◽  
Variable Power

The paper describes a method for a controlled change in the power of an electron beam during a pulse of submillisecond duration, using a source "SOLO" with a plasma cathode. The beam power is controlled by changing the amplitude of the beam current with a corresponding change in the concentration of the emission plasma. This control method allows generating submillisecond beams of variable power (up to 10 MW at a maximum rate of change of no more than 0.5 MW/µs), which can be used for processing various metallic materials in order to change the functional properties of their surface with the ability to control the rate of input of beam energy into the surface of these materials.

Iodoacetate depression in Xenopus sciatic single nerve fibers

1965 ◽  
Vol 208 (4) ◽  
pp. 720-723 ◽  
Author(s):  
Gordon M. Schoepfle ◽  
Eliska Atkins ◽  
Larry A. Schafer
Keyword(s):  
Membrane Potential ◽  
Maximum Rate ◽  
Nerve Fibers ◽  
Rate Of Change ◽  
Resting Membrane Potential ◽  
Delayed Effect ◽  
Fluid Exchange ◽  
Sodium Conductance ◽  
Single Nerve ◽  
A Chain

Under conditions of continuous fluid exchange at a pH 7.55, a 10-min exposure of Xenopus sciatic single nerve fibers to iodoacetate results in eventual decline in the maximum rate of change of membrane potential, even after a delay of an hour or more during which no changes are apparent. This delayed effect is obtained over an iodoacetate concentration range of 0.1–20.0 mm sodium iodoacetate. Neither the resting membrane potential nor the maximal limiting response obtained during hyperpolarization are affected at a time when iodoacetate has appreciably depressed the spike in the nonpolarized fiber. These findings are taken to indicate that iodoacetate blocks a chain of reactions at a link remote from the process directly concerned with maintenance of the resting level of the sodium conductance. Neither lactate nor pyruvate can be relied on to bring about recovery from the iodoacetate depression.

A rate nephelometer for measuring specific proteins by immunoprecipitin reactions.

1977 ◽  
Vol 23 (8) ◽  
pp. 1456-1464 ◽  
Author(s):  
J C Sternberg
Keyword(s):  
Maximum Rate ◽  
Serum Proteins ◽  
Rapid Determination ◽  
Scattered Light ◽  
Single Point ◽  
Rate Of Change ◽  
Specific Proteins ◽  
Antigen Antibody ◽  
Machine Readable

Abstract A kinetic nephelometric method and instrument have been developed for the rapid determination of specific serum proteins by means of immunoprecipitin reactions. The maximum rate of change of scattered light intensity in an antigen-antibody reaction can be made to occur within 60 s after initiation of the reaction and provides a measure of the antigen concentration under antibody excess conditions. A mathematical relationship has been found for the conversion of the nonlinear maximum rate data directly into a linear concentration read-out, making possible the use of single-point calibration. Instrument operating parameters and computations are programmed for a particular analysis by means of machine-readable cards. Antigen-excess samples are detected rapidly by injection of calibrator into the reaction mixture after the rate signal has dropped to a pre-selected level. The method correlates well with both radial immunodiffusion and end-point nephelometric methods.

Comparison Between Measured Radiance and a Radiation Model in a Spark-Ignition Engine

1990 ◽  
Vol 112 (3) ◽  
pp. 331-334 ◽  
Author(s):  
J. Yang ◽  
S. L. Plee ◽  
D. J. Remboski ◽  
J. K. Martin
Keyword(s):  
Heat Release ◽  
Release Rate ◽  
Maximum Rate ◽  
Spark Ignition ◽  
Rate Of Change ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Maximum Heat ◽  
Radiant Intensity ◽  
Maximum Heat Release

Measurements of the radiant emission in the near infrared have been obtained in a spark-ignition engine over a wide range of operating conditions. The system includes an in-cylinder optical sensor and associated detector. Prior work has shown correlations between the measured radiance and pressure quantities such as maximum cylinder pressure, crank angle of maximum pressure, and Indicated Mean Effective Pressure. Here are presented comparisons between the radiant intensity and a simplified model of the radiation emission, which demonstrate that the measured intensity is a function of the mass-burn fraction, mean burned-gas temperature, and the exposed combustion-chamber surface area. Further simplification leads to the conclusion that the time of the maximum rate of change of radiant intensity is the same as for the maximum heat-release rate, leading to the possibility of feedback control of spark timing. In addition, the magnitudes of the maximum rate of change of radiant emission and maximum heat-release rate have a linear relationship over a range of different operating conditions.

DIFFUSION UNDER CROSSED LOCAL AND GLOBAL BIASES IN DISORDERED SYSTEMS

2000 ◽  
Vol 11 (07) ◽  
pp. 1357-1369 ◽  
Author(s):  
SITANGSHU BIKAS SANTRA ◽  
WILLIAM A. SEITZ
Keyword(s):  
Relaxation Time ◽  
Disordered Systems ◽  
Maximum Rate ◽  
Rate Of Change ◽  
Square Lattice ◽  
Site Percolation ◽  
Local Bias ◽  
Random Walker ◽  
Percolation Clusters ◽  
Global Bias

Diffusion on 2D site percolation clusters at p = 0.7, 0.8, and 0.9 above pc on the square lattice in the presence of two crossed bias fields, a local bias B and a global bias E, has been investigated. The global bias E is applied in a fixed global direction whereas the local bias B imposes a rotational constraint on the motion of the diffusing particle. The rms displacement Rt ~ tk in the presence of both biases is studied. Depending on the strength of E and B, the behavior of the random walker changes from diffusion to drift to no-drift or trapping. There is always diffusion for finite B with no global bias. A crossover from drift to no-drift at a critical global bias Ec is observed in the presence of local bias B for all disordered lattices. At the crossover, value of the rms exponent changes from k = 1 to k < 1, the drift velocity vt changes from constant in time t to decreasing power law nature, and the "relaxation" time τ has a maximum rate of change with respect to the global bias E. The value of critical bias Ec depends on the disorder p as well as on the strength of local bias B. Phase diagrams for diffusion, drift, and no-drift are obtained as a function of bias fields E and B for these systems.

Correlation Among Shear Rate Measures in Vascular Flows

1987 ◽  
Vol 109 (1) ◽  
pp. 25-26 ◽  
Author(s):  
Morton H. Friedman ◽  
Owen J. Deters
Keyword(s):  
Shear Rate ◽  
Vessel Wall ◽  
Maximum Rate ◽  
Laser Doppler Anemometry ◽  
Rate Of Change ◽  
Flow Reversal ◽  
Flow Through ◽  
The Mean ◽  
Highly Correlated

A variety of shear rate measures have been calculated from hemodynamic data obtained by laser Doppler anemometry in flow-through casts of human aortic bifurcations. Included are measures sensitive to the mean and amplitude of the shear rate, its maximum rate of change, the duration of stasis and flow reversal near the wall, and the unidirectionality of the flow. Many of these measures are highly correlated with one another. This suggests that that it will be difficult to identify from in vivo measurements those aspects of the flow field to which the vessel wall is most sensitive. It may be possible to separate the effects of purely temporal factors (e.g., the duration of flow reversal) from those related to wall shear stress.

scholarly journals ABOUT A POSSIBLE CONNECTION BETWEEN EARTHQUAKES AND LUNAR-SOLAR GRAVITY VARIATIONS

2018 ◽  
pp. 51-57 ◽  
Author(s):  
Yu. V. Antonov
Keyword(s):  
Maximum Rate ◽  
Extreme Points ◽  
Rate Of Change ◽  
Earth’S Crust ◽  
Maximum Gradient ◽  
The Earth ◽  
External Impact ◽  
Gravity Variations ◽  
Earth's Crust ◽  
Solar Gravity

A possible correlation between the destructive earthquakes of magnitude M = 7 and above and luni-solar gravity variations between 1975 and 2015 has been analyzed. The lunar-solar variations are characterized by three extreme points: the maximum and minimum values of gravity, and the maximum rate of change of variations. At this time, there is an extreme impact of lunar-solar attraction on the earth’s crust and the Earth as a whole. Variations can be a source of irreversible deformation in the earth’s crust. If in this case, there is an additional external impact of space factors, the probability of an earthquake is increased. In a time, the earthquakes are grouped near extremes of lunar-solar variations: half of the events are associated with the maximum gradient of variations change, and the second half is equally confined to the maximum and minimum value of gravity variations. Lunar-solar variations of gravity in conjunction with other cosmic influences can cause earthquakes.

Sign in / Sign up

Export Citation Format

Share Document