Transient phenomena in capillary exchange

1954 ◽  
Vol 16 (1) ◽  
pp. 55-58 ◽  
Author(s):  
H. D. Landahl
Keyword(s):  
Transient Phenomena ◽  
Capillary Exchange

Die Atemnotsyndrom-Lunge-Sequestrationsorgan für lösliches Fibrin

1985 ◽  
Vol 05 (03) ◽  
pp. 103-107
Author(s):  
U. Bleyl
Keyword(s):  
Soluble Fibrin ◽  
Pulmonary Failure ◽  
Capillary Exchange ◽  
Fibrin Monomers

SummaryMultifactorial permeability disorders of the alveolo-capillary exchange membranes are one of the main pathophysiologic principles of pulmonary failure in the ARDS. Under the conditions of a generalized activation of coagulation these permeability disorders result in a leakage of circulating fibrin monomers and oligomers into the pulmonary interstitia and alveoli, even before the monomers and oligomers may precipitate intravascularly to disseminated microthrombi. Under the patho-physiologic conditions of an ARDS the lungs thus become an organ of excretion for soluble, intravascularly circulating fibrin monomers and oligomers, an organ of sequestration for soluble fibrin.

TRANSIENT PHENOMENA DURING COLLAPSE OF A PRESSURIZED VAPOR FILM

1970 ◽  
Author(s):  
E. I. Griggs ◽  
J. L. Carson ◽  
R. J. Schoenhals ◽  
Edgar R. F. Winter
Keyword(s):  
Vapor Film ◽  
Transient Phenomena

A New Computational Procedure to Predict Transient Hydroplaning Performance of a Tire

2001 ◽  
Vol 29 (1) ◽  
pp. 2-22 ◽  
Author(s):  
T. Okano ◽  
M. Koishi
Keyword(s):  
Complex Geometry ◽  
Fluid Flows ◽  
Computational Procedure ◽  
Vehicle Body ◽  
Fluid Viscosity ◽  
Safe Driving ◽  
Transient Phenomena ◽  
Vehicle Velocity ◽  
Fixed Reference ◽  
Volume Method

Abstract “Hydroplaning characteristics” is one of the key functions for safe driving on wet roads. Since hydroplaning depends on vehicle velocity as well as the tire construction and tread pattern, a predictive simulation tool, which reflects all these effects, is required for effective and precise tire development. A numerical analysis procedure predicting the onset of hydroplaning of a tire, including the effect of vehicle velocity, is proposed in this paper. A commercial explicit-type FEM (finite element method)/FVM (finite volume method) package is used to solve the coupled problems of tire deformation and flow of the surrounding fluid. Tire deformations and fluid flows are solved, using FEM and FVM, respectively. To simulate transient phenomena effectively, vehicle-body-fixed reference-frame is used in the analysis. The proposed analysis can accommodate 1) complex geometry of the tread pattern and 2) rotational effect of tires, which are both important functions of hydroplaning simulation, and also 3) velocity dependency. In the present study, water is assumed to be compressible and also a laminar flow, indeed the fluid viscosity, is not included. To verify the effectiveness of the method, predicted hydroplaning velocities for four different simplified tread patterns are compared with experimental results measured at the proving ground. It is concluded that the proposed numerical method is effective for hydroplaning simulation. Numerical examples are also presented in which the present simulation methods are applied to newly developed prototype tires.

Investigations into and optimisation of the performance of sewage detention tanks during storm rainfall events

1999 ◽  
Vol 39 (2) ◽  
pp. 43-52 ◽  
Author(s):  
R. Kowalski ◽  
J. Reuber ◽  
Jürgen Köngeter
Keyword(s):  
Flow Field ◽  
Pollutant Transport ◽  
Cleaning Efficiency ◽  
Rainfall Events ◽  
Transient Phenomena ◽  
Numerical Studies ◽  
Hydraulic Load ◽  
Storm Rainfall ◽  
Different Levels ◽  
Sewage Systems

Combined Sewage Detention Tanks (CSDT) are components of combined sewage systems commonly used in Germany. A lack of knowledge of the processes occurring within these structures causes the engineer to apply conceptual approaches in the simulation of pollutant transport. The investigations presented were implemented in an integrated systematic way. Extensive analytical, experimental and numerical studies of steady and transient phenomena taking place in CSDTs were carried out simulating different levels of hydraulic load. The study of the flow field and the simulation of sedimentation and erosion under realistic conditions resulted in proposals for modification and optimisation of the function of CSDTs. A simple way of predicting the cleaning efficiency is presented.

“Stringing Together” Capillary Exchange

HAPS Educator ◽  
2019 ◽  
Vol 23 (2) ◽  
pp. 464-468
Author(s):  
Alejandro Quinonez ◽  
Krista Rompolski
Keyword(s):  
Capillary Exchange

scholarly journals New Approaches for the Observation of Transient Phenomena in Critical Marine Environment

2021 ◽  
Vol 9 (6) ◽  
pp. 578
Author(s):  
Roberta Ferretti ◽  
Massimo Caccia ◽  
Massimo Coltorti ◽  
Roberta Ivaldi
Keyword(s):  
Mediterranean Sea ◽  
Marine Environment ◽  
Environmental Conditions ◽  
Marine Environments ◽  
Transient Phenomena ◽  
New Approaches ◽  
Marine Vehicles ◽  
New Methodologies ◽  
Biogeochemical Parameters ◽  
Very High

This paper focuses on the development of new approaches to observe transient phenomena in critical marine environments using autonomous marine vehicles (AMVs) for the acquisition of physical and biogeochemical parameters of water and seabed characterization. The connection with metrological principles, together with the adoption of observing methodologies adjustable according to the specific marine environment being studied, allows researchers to obtain results that are reliable, reproducible, and comparable with those obtained through the classic monitoring methodologies. Tests were executed in dramatically dynamic, sensitive, and fragile areas, where the study and application of new methodologies is required to observe phenomena strongly localized in space and requiring very high resolutions, in time. Moreover, the harsh environmental conditions may present risks not only for the quality and quantity of the acquired data but also for the instrumentation and the operators. This is the case, for instance, in polar marine environments in proximity of tidal glaciers and in the Mediterranean Sea in areas characterized by seabed degassing activities, where AMV-supported monitoring procedures can allow for the safe observation of not repeatable and not completely predictable events.

Effects of flow heterogeneity on the measurement of capillary exchange in the lung

1995 ◽  
Vol 79 (5) ◽  
pp. 1449-1460 ◽  
Author(s):  
S. D. Caruthers ◽  
T. R. Harris ◽  
K. A. Overholser ◽  
N. A. Pou ◽  
R. E. Parker
Keyword(s):  
Effective Diffusivity ◽  
Relative Dispersion ◽  
Flow Heterogeneity ◽  
Homogeneous Flow ◽  
Capillary Recruitment ◽  
Flow Models ◽  
Capillary Exchange ◽  
Variable Recruitment ◽  
Area Product ◽  
Recruitment Model

The effects of flow heterogeneity on the measurement of transcapillary escape of small molecules for perfused in situ sheep lungs were evaluated. Lungs were studied at five flows (1.5–5.0 l/min) ranging from zone 1 to zone 3 conditions. At each flow, multiple indicator-dilution curves were collected using 14C-labeled urea (U) or butanediol (B) as the diffusing tracer, and radiolabeled 15-microns microspheres were injected. The lungs were removed, dried, sectioned, weighed, and counted for microsphere radioactivity. Flow heterogeneity expressed as relative dispersion, decreased with increasing flow, from 0.838 +/- 0.179 (mean +/- SD, n = 8) to 0.447 +/- 0.119 (n = 6). We applied homogeneous flow models of capillary exchange to compute permeability-surface area product (PS) and a related parameter, D1/2S, for diffusing tracers. (D is effective diffusivity of capillary exchange.) PS and D1/2S increased to a maximum with increasing flow, but the ratio of D1/2SU to D1/2SB remained constant. A new model incorporating flow heterogeneity and recruitment (the variable recruitment model) was used. The variable recruitment model described the effects of flow on capillary recruitment, but incorporating heterogeneity into the computation did not alter D1/2S values from those computed assuming homogeneous flow.

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