Understanding Thermal Drift in Liquid Nitrogen Loads Used for Radiometric Calibration in the Field

2014 ◽  
Vol 31 (3) ◽  
pp. 647-655 ◽  
Author(s):  
Scott N. Paine ◽  
David D. Turner ◽  
Nils Küchler
Keyword(s):  
Liquid Nitrogen ◽  
Boiling Point ◽  
Volume Fraction ◽  
Radiometric Calibration ◽  
Initial Boiling Point ◽  
Nitrogen Loads ◽  
Outdoor Environments ◽  
Infrared Wavelengths ◽  
Simulated Wind ◽  
Liquid Nitrogen Bath

Abstract An absorbing load in a liquid nitrogen bath is commonly used as a radiance standard for calibrating radiometers operating at microwave to infrared wavelengths. It is generally assumed that the physical temperature of the load is stable and equal to the boiling point temperature of pure N2 at the ambient atmospheric pressure. However, this assumption will fail to hold when air movement, as encountered in outdoor environments, allows O2 gas to condense into the bath. Under typical conditions, initial boiling point drift rates of order 25 mK min−1 can occur, and the boiling point of a bath maintained by repeated refilling with pure N2 can eventually shift by approximately 2 K. Laboratory bench tests of a liquid nitrogen bath under simulated wind conditions are presented together with an example of an outdoor radiometer calibration that demonstrates the effect, and the physical processes involved are explained in detail. A key finding is that in windy conditions, changes in O2 volume fraction are related accurately to fractional changes in bath volume due to boiloff, independent of wind speed. This relation can be exploited to ensure that calibration errors due to O2 contamination remain within predictable bounds.

DISPERSION OF CHEMICALLY TREATED CRUDE OIL IN NORWEGIAN OFFSHORE WATERS

1983 ◽  
Vol 1983 (1) ◽  
pp. 7-14 ◽  
Author(s):  
Rainer G. Lichtenthaler ◽  
Per S. Daling
Keyword(s):  
Crude Oil ◽  
Water Samples ◽  
Boiling Point ◽  
Laboratory Tests ◽  
Oil Spills ◽  
Chromatographic Technique ◽  
Chemical Analyses ◽  
Initial Boiling Point ◽  
The Third ◽  
Control Water

ABSTRACT In May and July 1982, two series of dispersant research oil spills were carried out off the Norwegian coast. The May series comprised three discharges of 2,000 liters of Statfjord topped crude oil (initial boiling point 150 °C). Two of the slicks were treated with dispersants (A and B) from a boat while the third untreated slick served as control. The July series comprised four discharges of 2,000 liters of Statfjord crude oil, with the application of three dispersants (A, B, and C), and one untreated slick as control. Water samples were collected from under the slicks and analyzed for total petroleum using a gas chromatographic technique. Chemical analyses showed six percent dispersion of the oil for dispersant A, and 17 percent for dispersant ? in the May series. Effectiveness of dispersants in the July series was found to be 19 percent for dispersant A and 22 percent and two percent for dispersants ? and C, respectively. Gas chromatographic analyses showed in several cases the presence of dispersants (up to two ppm) in water samples without the presence of petroleum at all. The highest oil contents found in water samples were 10 ppm at a one meter depth. The variations in the effectiveness of the three dispersants tested in the field were later confirmed in laboratory tests.

scholarly journals Petroleum Hydrocarbon Quarterly Boiling Range Distribution of Iraqi Crude Oil by Simulated Distillation Method

2021 ◽  
Vol 11 (4) ◽  
pp. 1-16
Author(s):  
Aliaa K. Alhead ◽  
Shatha F. Khaleel
Keyword(s):  
Crude Oil ◽  
Boiling Point ◽  
Internal Standard ◽  
Heavy Component ◽  
Point Distribution ◽  
Initial Boiling Point ◽  
Simulated Distillation ◽  
Point Increase ◽  
Oil Characterization ◽  
Light Components

This study includes analysis of different crude oil stock for various field Iraqi oil by gas chromatography instrument, using simulated distillation technique for determining the  initial and final  boiling point distribution and specified compound distillation information (normal paraffins) (Recovery W/W) for (nC5 – nC44), ASTM-D5307 becomes the analytical method. This method need tow samples; the first one spiked with internal standard and the second without internal standard. This analysis for quantitative and qualitative oil characterization which is often useful for evaluating the range of hydrocarbons in crude oil using Simulated Distillation. The study was performed using: Quarterly analysis of SIMDIS GC Distillation for three field (East Baghdad, Badra, Amara) Comparison of analyzes of SIMDIS GC Distillation with Different API (light, intermediate, heavy) with Initial boiling point (IBP). Finding experimental relationship between API and Initial boiling point (IBP):          The result of this study shows that the boiling point increase as the number of carbon is increase, the values of n-Pentane (nC5) to n- Tetratetracontane (nC44) (w/w) changes from winter and summer (difference in temperatures), Positive correlation between C6 and C5 with API, where their percentages increase with increasing API for crude oil and C6 and C5 are lower in summer than in winter due to the evaporation of light components of the samples in summer. Initial boiling point increase as the API is decrease that mean in crude oil have heavy component increases and light component decrease (inverse relationship).

Nanostructuring of 2xxx Aluminum Alloy under Cryorolling to High Strains

2016 ◽  
Vol 838-839 ◽  
pp. 367-372 ◽  
Author(s):  
Elena Avtokratova ◽  
Stanislav Krymskiy ◽  
Anastasia Mikhaylovskaya ◽  
Oleg Sitdikov ◽  
Michael Markushev
Keyword(s):  
Aluminum Alloy ◽  
Liquid Nitrogen ◽  
Dynamic Recovery ◽  
Volume Fraction ◽  
Effective Strain ◽  
Grain Structure ◽  
Alloy Structure ◽  
2024 Aluminum Alloy ◽  
Continuous Recrystallization ◽  
Nanometric Size

The structure transformations in the D16 (2024) aluminum alloy caused by isothermal rolling with effective strain up to e ~3.5 at a temperature of liquid nitrogen were investigated. It is shown that under straining to e ~2.0 the dislocation structure containing cells of the nanometric size is formed. At higher strains the dynamic recovery and continuous recrystallization result in the development of a mixed nano(sub) grain structure, which after e ~3.5 is characterized by the size and volume fraction of grains ~ 150 nm and 40-45%, respectively. Nature of the alloy structure transformations is discussed.

The Microstructures and Hardness Analysis of a New Hypereutectoid Mn-Cr-Mo-V Steel

2013 ◽  
Vol 58 (2) ◽  
pp. 563-568
Author(s):  
R. Dabrowski ◽  
E. Rozniata ◽  
R. Dziurka
Keyword(s):  
Heat Treatment ◽  
Chemical Composition ◽  
Liquid Nitrogen ◽  
Retained Austenite ◽  
Volume Fraction ◽  
Chemical Compositions ◽  
Tool Steels ◽  
Maximum Hardness ◽  
Hypereutectoid Steel ◽  
Tempering Temperature

The results of a microstructure and hardness investigations of a new hypereutectoid Mn-Cr-Mo-V steel, imitating by its chemical composition tool steels, are presented in the paper. The microstructure as well hardness changes, caused by austenitising and tempering temperatures were assessed, for samples quenched and sub-quenched in liquid nitrogen, directly after the quenching treatment. Additionally, the influence of the tempering temperature on the volume fraction of the retained austenite was estimated. New hypereutectoid steel, after an appropriate heat treatment obtained the relevant hardness of the tools used in the cold and hot working proces. It was indicated that the steel hardness increases with the increases of the austenitising temperature. At 800ºC the hardness of the quenched samples were equal 895HV, and for the sub-quenched samples 937HV. The maximum hardness, after tempering (746HV), was found at a temperature of 520ºC. It will be possible, in future, to apply this obtained investigation results in designing chemical compositions and microstructures of the new hypereutectoid alloyed steels of properties required by their users.

Alternative butanol/gasoline and butanol/diesel fuel blends: An analysis of the interdependence between physical-chemical properties by a multivariate principal component analysis model

2018 ◽  
Vol 31 (5) ◽  
pp. 733-754
Author(s):  
Luiz Filipe Paiva Brandão ◽  
Jez Willian Batista Braga ◽  
Paulo Anselmo Ziani Suarez
Keyword(s):  
Principal Component Analysis ◽  
Diesel Fuel ◽  
Boiling Point ◽  
Principal Component ◽  
Component Analysis ◽  
Analysis Model ◽  
Principal Component Analysis Model ◽  
Initial Boiling Point ◽  
Fuel Blends ◽  
Physical Chemical

The use of butanol as an oxygenated component in blends with fossil fuels has recently been recognized by the industry as a promising and green alternative for automotive use, being subject of several recent studies. In this work, the interdependence between important physical-chemical properties of butanol/gasoline and butanol/diesel fuel blends was investigated using a multivariate principal component analysis model. The model dataset was based on laboratorial results of density, kinematic viscosity, distillation, vapor pressure, octane rating, anti-knock index, flash point and cetane number in a total of 48 blends, the variables of which were transformed to principal component analysis matrix representations, pre-processed and then analyzed. A good coherence was observed between the experimental results in laboratory and those derived from the principal component analysis models, evidencing important physical-chemical changes in blends’ properties due to the butanol addition. Principal component analysis scores and loadings plots could provide an intuitive and comprehensive data visualization. Butanol/gasoline fuel blends showed an overall increase in density, octane rating and higher distillation temperatures from the initial boiling point to T60 (temperature of the 60% distilled volume) and reduction of the distillation temperatures from T70 to the final boiling point. An absolute reduction in values of all properties was observed for butanol/diesel fuel blends, especially for initial distillation temperatures from initial boiling point to T35, T98, final boiling point and flash point, whereas the reductions for density, kinematic viscosity and cetane number were less intense. Total variances of up to 92.50% and 94.14% were explained by the proposed principal component analysis model, depending on the blends matrix and butanol isomer composition.

Sign in / Sign up

Export Citation Format

Share Document