Determination of the water activity of some hygroscopic food materials by a dew-point method

1965 ◽  
Vol 16 (2) ◽  
pp. 71-78 ◽  
Author(s):  
G. Ayerst
Keyword(s):  
Water Activity ◽  
Point Method ◽  
Dew Point

Application of OLI Electrolyte Simulation to the Resolution of Corrosion Concerns Within a Reciprocating Compressor

2012 ◽  
Author(s):  
Diane L. Stewart ◽  
Anthony J. Gerbino ◽  
Tony Scribner
Keyword(s):  
Simulation Software ◽  
Dew Point ◽  
Reciprocating Compressor ◽  
Particulate Contamination ◽  
Ionic Equilibria ◽  
Water Ph ◽  
Condensed Water ◽  
Compressor Reliability

A 38 MMSCF/D Cooper Bessemer Model LM-9 reciprocating compressor in hydrogen service at the Praxair Westlake LA facility has experienced notable particulate contamination within the feed gas. The particulates were believed to be caused by upstream piping corrosion; however, to definitely state the cause, the properties of the fluid existing in the five-stage compressor needed to be more fully understood. An OLI electrochemical simulation software was used for dew point prediction, determination of the condensed phase ionic equilibria, and corrosion rate prediction. These tasks were beyond capabilities of the site-licensed UniSim software, as presently configured. Specifically, the model was used to identify the dew point conditions (temperature, pressure) and properties of the condensed water (pH, corrosivity, dissolved O2, and chlorine speciation). Model results were compared with site inspection findings. Subsequently, recommended limits for chlorine and oxygen in the feed gas were established to improve long term compressor reliability.

Determination of Bubble-Point and Dew-Point Pressure Without a Visual Cell

2014 ◽  
Author(s):  
R.. Hosein ◽  
R.. Mayrhoo ◽  
W. D. McCain
Keyword(s):  
Oil And Gas ◽  
Saturation Pressure ◽  
Volatile Oil ◽  
Phase Region ◽  
Gas Condensate ◽  
Dew Point ◽  
Bubble Point ◽  
Point Pressure ◽  
Dew Point Pressure

Abstract Bubble-point and dew-point pressures of oil and gas condensate reservoir fluids are used for planning the production profile of these reservoirs. Usually the best method for determination of these saturation pressures is by visual observation when a Constant Mass Expansion (CME) test is performed on a sample in a high pressure cell fitted with a glass window. In this test the cell pressure is reduced in steps and the pressure at which the first sign of gas bubbles is observed is recorded as bubble-point pressure for the oil samples and the first sign of liquid droplets is recorded as the dew-point pressure for the gas condensate samples. The experimental determination of saturation pressure especially for volatile oil and gas condensate require many small pressure reduction steps which make the observation method tedious, time consuming and expensive. In this study we have extended the Y-function which is often used to smooth out CME data for black oils below the bubble-point to determine saturation pressure of reservoir fluids. We started from the initial measured pressure and volume and by plotting log of the extended Y function which we call the YEXT function, with the corresponding pressure, two straight lines were obtained; one in the single phase region and the other in the two phase region. The point at which these two lines intersect is the saturation pressure. The differences between the saturation pressures determined by our proposed YEXT function method and the observation method was less than ± 4.0 % for the gas condensate, black oil and volatile oil samples studied. This extension of the Y function to determine dew-point and bubble-point pressures was not found elsewhere in the open literature. With this graphical method the determination of saturation pressures is less tedious and time consuming and expensive windowed cells are not required.

scholarly journals Evaluation of Inhomogeneous Resistive Layers by a Four Point Method

1981 ◽  
Vol 7 (4) ◽  
pp. 211-216
Author(s):  
György Fodor ◽  
Miklós Szilágyi ◽  
László Zombory
Keyword(s):  
Sheet Resistance ◽  
Point Method ◽  
Narrow Strip ◽  
Resistive Layer

This paper describes the determination of the sheet resistance of a narrow strip located in a homogeneous resistive layer of different resistivity. The application of the method for the evaluation of inhomogeneous layers used for thermoprinter head production is discussed.

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