Startup flow of viscoelastic fluids in a circular pipe under constant flow rates (abstract)

1991 ◽  
Vol 35 (4) ◽  
pp. 699-699
Author(s):  
Noriyasu Mori ◽  
Hiroaki Takehara ◽  
Yoshiro Konishi ◽  
Kiyoji Nakamura
Keyword(s):  
Viscoelastic Fluids ◽  
Circular Pipe ◽  
Constant Flow ◽  
Flow Rates

scholarly journals Startup Flow of Viscoelastic Fluids in a Circular Pipe under Constant Flow Rates

1990 ◽  
Vol 18 (2) ◽  
pp. 69-75 ◽  
Author(s):  
Noriyasu Mom ◽  
Hiroaki TAKEHARA ◽  
Yoshiro KONISHI ◽  
Kiyoji NAKAMURA
Keyword(s):  
Viscoelastic Fluids ◽  
Circular Pipe ◽  
Constant Flow ◽  
Flow Rates

scholarly journals Numerical Calculation of the Startup Flow of Viscoelastic Fluids in a Circular Pipe under Constant Flow Rates

1991 ◽  
Vol 19 (3) ◽  
pp. 125-129
Author(s):  
Noriyasu MORI ◽  
Yoshiro KONISHI ◽  
Takumi KAIGE ◽  
Kiyoji NAKAMURA
Keyword(s):  
Numerical Calculation ◽  
Viscoelastic Fluids ◽  
Circular Pipe ◽  
Constant Flow ◽  
Flow Rates

Numerical calculation of the startup flow of viscoelastic fluids in a circular pipe under constant flow rates (abstract)

1992 ◽  
Vol 36 (5) ◽  
pp. 985-985
Author(s):  
Noriyasu Mori ◽  
Yoshiro Konishi ◽  
Takumi Kaige ◽  
Kiyoji Nakamura
Keyword(s):  
Numerical Calculation ◽  
Viscoelastic Fluids ◽  
Circular Pipe ◽  
Constant Flow ◽  
Flow Rates

An anti-settling sample delivery instrument for serial femtosecond crystallography

2012 ◽  
Vol 45 (4) ◽  
pp. 674-678 ◽  
Author(s):  
Lukas Lomb ◽  
Jan Steinbrener ◽  
Sadia Bari ◽  
Daniel Beisel ◽  
Daniel Berndt ◽  
...  
Keyword(s):  
Constant Flow ◽  
Syringe Pump ◽  
Experimental Conditions ◽  
Flow Rates ◽  
X Ray ◽  
Constant Flow Rate ◽  
Significant Impairment ◽  
Working Principle ◽  
After Hours ◽  
Serial Femtosecond Crystallography

Serial femtosecond crystallography (SFX) using X-ray free-electron laser (FEL) sources has the potential to determine the structures of macromolecules beyond the limitation of radiation damage and without the need for crystals of sufficient size for conventional crystallography. In SFX, a liquid microjet is used to inject randomly oriented crystals suspended in their storage solution into the FEL beam. Settling of crystals in the reservoir prior to the injection has been found to complicate the data collection. This article details the development of an anti-settling sample delivery instrument based on a rotating syringe pump, capable of producing flow rates and liquid pressures necessary for the operation of the injector. The device has been used successfully with crystals of different proteins, with crystal sizes smaller than 20 µm. Even after hours of continuous operation, no significant impairment of the experiments due to sample settling was observed. This article describes the working principle of the instrument and sets it in context with regard to the experimental conditions used for SFX. Hit rates for longer measuring periods are compared with and without the instrument operating. Two versions of the instrument have been developed, which both deliver sample at a constant flow rate but which differ in their minimum liquid flow rates and maximum pressures.

Tracer Gas Mapping of a Beverage Cart Wake in a Twin Aisle Aircraft Cabin

2011 ◽  
Author(s):  
A. Tristan Trupka ◽  
Mohammad H. Hosni ◽  
Byron W. Jones
Keyword(s):  
Contaminant Transport ◽  
Heat Load ◽  
Constant Flow ◽  
Outdoor Air ◽  
Tracer Gas ◽  
Flow Rates ◽  
Constant Flow Rate ◽  
Co2 Level ◽  
Carbon Dioxide Co2 ◽  
Injection Location

An experimental study is performed in a mockup Boeing 767 cabin section consisting of eleven rows with seven seats per row. Carbon Dioxide (CO2) tracer gas is injected at a constant flow rate at a location of interest until concentrations in the cabin reach steady state. Ventilation equipment and flow rates representative of an actual aircraft are used for all experiments. Seats in the mockup are occupied by thermal manikins to simulate passenger heat load. A motorized beverage cart traverses the length of the cabin aisle passing by the injection location. The concentrations of tracer gas displaced by the cart are measured at locations throughout the cabin. Comparing these measurements to baseline readings taken with no cart movement, a map of the degree to which contaminant transport is affected by the beverage cart is calculated. The cabin mockup is supplied by 100% outdoor air through actual Boeing supply ductwork and linear diffusers along the cabin length above the aisles. The CO2 level is measured in the inlet air, measurement locations in the cabin, and exhaust air using nondispersive infrared (NDIR) sensors. Measured results are reported for all (54) seat locations downstream of the cart traverse/injection location for an injection location near the rear of the cabin. Analogous measurements are also conducted examining the effect of variation in cart speed and modified injection location.

Work With Chemical Additives Advances Understanding of Relative Permeability Shifts

2021 ◽  
Vol 73 (09) ◽  
pp. 37-38
Author(s):  
Chris Carpenter
Keyword(s):  
Steady State ◽  
Relative Permeability ◽  
Flow Rate ◽  
Pressure Difference ◽  
Effective Permeability ◽  
Constant Flow ◽  
Chemical Additives ◽  
Flow Rates ◽  
Steady State Method ◽  
Tight Rocks

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 201520, “Advances in Understanding Relative Permeability Shifts by Imbibition of Surfactant Solutions Into Tight Plugs,” by Mohammad Yousefi, Lin Yuan, and Hassan Dehghanpour, SPE, University of Alberta, prepared for the 2020 SPE Annual Technical Conference and Exhibition, originally scheduled to be held in Denver, Colorado, 5–7 October. The paper has not been peer reviewed. Various chemical additives have been proposed recently to enhance imbibition oil recovery from tight formations during shut-in periods after hydraulic fracturing operations. In the complete paper, the authors develop and apply a laboratory protocol mimicking leakoff, shut-in, and flowback processes to evaluate the effects of fracturing-fluid additives on oil regained permeability. A conventional coreflooding apparatus is modified to measure oil effective permeability (koeff) before and after the surfactant-imbibition experiments. Methodology Proposed Technique for Measuring Oil Effective Permeability. Despite the simplicity of the steady-state method, measuring permeability of tight rocks with this technique is challenging because of its time-consuming nature and the fact that accurate measurement is necessary of extremely low flow rates corresponding to low injectivity of tight rocks. The authors use a pair of plugs from a well drilled in the Montney formation that is a stratigraphic unit of the Lower Triassic age in the western Canadian sedimentary basin located in British Columbia and Alberta. It is mainly a low-permeability siltstone reservoir. In the modified coreflooding apparatus, the authors reduce the effect of compressibility in order to reduce the duration of the transient period by approximately one order of magnitude. Because monitoring changes in pressure is much easier and more accurate than monitoring flow-rate changes, a constant flow-rate mode is used and pressure is recorded with time. Oil is injected at different constant flow rates (qo), and the inlet pressure is monitored. The stable pressure difference across the plug is recorded for each flow rate. After steady-state conditions are reached based on the pressure profile, the qo is increased. This process is repeated until four stable pressure differences corresponding to four different qo are obtained. After the highest qo is reached, it is decreased in similar steps to check the repeatability of each data point. The permeability is calculated with the Darcy equation and slope of the qo vs. stable pressure difference across the plug.

Catheter position and blood gases during constant-flow ventilation

1987 ◽  
Vol 62 (2) ◽  
pp. 513-519 ◽  
Author(s):  
A. S. Slutsky ◽  
A. S. Menon
Keyword(s):  
Steady State ◽  
Flow Rate ◽  
Blood Gases ◽  
Constant Flow ◽  
Arterial Blood Gases ◽  
Catheter Position ◽  
Flow Rates ◽  
Arterial Blood ◽  
Tracheal Carina ◽  
Co2 Elimination

We studied the effect of catheter position and flow rate on gas exchange during constant-flow ventilation (CFV) in eight anesthetized, paralyzed dogs. The distal tips of the insufflation catheters were positioned 0.5, 2.0, 3.5, and 5.0 cm from the tracheal carina. Flow rates were varied between 10 and 55 l/min and steady-state arterial blood gases were measured. At a given flow rate, arterial CO2 pressure (PaCO2) decreased as CFV was administered further into the lung up to a distance of 3.5 cm from the carina; there were no significant differences in PaCO2 at 3.5 and 5.0 cm. For a given catheter position, PaCO2 decreased with increasing flow rate up to a flow rate of 40 l/min. Further increases in flow rate had no significant effect on PaCO2. Arterial O2 pressure (PaO2) was relatively constant at all flow rates and catheter positions. We conclude that, up to a point, CO2 elimination can be improved by positioning the catheters further into the lung; advancing the catheters further than 3.5 cm from the carina may cause over-ventilation of specific lung regions resulting in a relative plateau in CO2 elimination and relatively constant PaO2's. Positioning the catheters further into the lung permits the use of lower flow rates, thus potentially minimizing the risk of barotrauma.

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