scholarly journals New temperature and oxygen fugacity data of Martian nakhlite from Northwest Africa (NWA) 5790 and implications for shallow sulphur degassing

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Zilong Wang ◽  
Wei Tian ◽  
Yankun Di
Keyword(s):  
Oxygen Fugacity ◽  
Impact Crater ◽  
Burial Depth ◽  
Pressure Data ◽  
Northwest Africa ◽  
Extended Range ◽  
Crystallisation Temperature ◽  
Lava Pile ◽  
Sulphur Species ◽  
Good Agreement

AbstractNewly analysed titanomagnetite–ilmenite (Tim–Ilm) intergrowths from Martian nakhlite meteorite Northwest Africa (NWA) 5790 yielded crystallisation temperature up to 1032 °C and oxygen fugacity (fO2) up to ΔQFM + 1.6, notably higher than previous estimates for nakhlite magmas (temperature < 950 °C, fO2 = ΔQFM − 0.5 to ΔQFM + 1). To interpret how the magma was reduced from ΔQFM − 0.5 to ΔQFM + 1.6, we used D-Compress to model the sulphur degassing process within a single thick lava pile. For fO2 to significantly decrease in this extended range, a sulphur-rich (S content 4000–7000 ppm) Martian lava flow had to degas all the sulphur species at a certain final degassing pressure, which was 2–4 bar for NWA 988 and Lafayette and < 0.7 bar for Y-000593 and Nakhla. These final degassing pressure data are in good agreement with the Martian nakhlite burial depth estimated by other petrological and geochemical methods. These estimates are also comparable with the excavation depth of ~ 40 m based on the small (6.5 km in diameter) impact crater over the Elysium lava plain. The fO2-controlled sulphur degassing pressure may constitute a method for estimating the burial depth of sulphur-rich lava flows on Mars.

New temperature and oxygen fugacity data of Martian nakhlite from Northwest Africa (NWA) 5790 and implications for sulphur degassing depth

2021 ◽  
Author(s):  
Zilong Wang ◽  
Wei Tian
Keyword(s):  
Oxygen Fugacity ◽  
Impact Crater ◽  
Lava Flows ◽  
Burial Depth ◽  
Pressure Data ◽  
Northwest Africa ◽  
Extended Range ◽  
Crystallisation Temperature ◽  
Sulphur Species ◽  
Good Agreement

Abstract Newly analysed titanomagnetite–ilmenite (Tim–Ilm) intergrowths from Martian nakhlite meteorite Northwest Africa (NWA) 5790 yielded crystallisation temperature up to 1032°C and oxygen fugacity (fO2) up to ΔQFM + 1.6, notably higher than previous estimates for nakhlite magmas (temperature < 950°C, fO2 = ΔQFM-1 to ΔQFM + 1). To interpret how the magma was reduced from ΔQFM-1 to ΔQFM + 1.6, we used D-Compress to model the sulphur degassing process. For fO2 to significantly decrease in this extended range, the sulphur-rich Martian magma had to degas all the sulphur species at a certain final degassing pressure, which was 2–4 bar for NWA 988 and Lafayette and < 0.7 bar for Y-000593 and Nakhla. These final degassing pressure data are in good agreement with the Martian nakhlite burial depth estimated by other petrological and geochemical methods. These estimates are also comparable with the excavation depth of ~ 40 m based on the small (6.5 km in diameter) impact crater over the Elysium lava plain. The fO2-controlled sulphur degassing pressure may constitute a method for estimating the burial depth of sulphur-rich lava flows on Mars.

Heat-Transfer Characteristics of Subsea Pipelines Embedded in Multilayered Soils

SPE Journal ◽  
2020 ◽  
Vol 25 (03) ◽  
pp. 1128-1139
Author(s):  
Dong-Su Park ◽  
Mun-Beom Shin ◽  
Young-Kyo Seo
Keyword(s):  
Heat Transfer ◽  
Analytical Formula ◽  
Soil Conditions ◽  
Burial Depth ◽  
Overall Heat Transfer Coefficient ◽  
Scale Experiment ◽  
Subsea Pipelines ◽  
Multilayered Soils ◽  
Pipeline Design ◽  
Good Agreement

Summary A good pipeline design must ensure that the heat loss is small enough for flow assurance despite unfavorable hydrate and wax depositions. The objective of this study is to experimentally verify a formula for the modified overall-heat-transfer coefficient (OHTC) that considers multilayered soil conditions for steady-state subsea pipelines. A laboratory-scale experiment is conducted to simulate the flows of cold seawater and hot crude oil inside the pipes immersed in multilayered soils at nine burial-depth rates. The obtained results are in good agreement with the data obtained by a previously derived OHTC analytical formula.

New Relationship Between Resistivity Index and Relative Permeability

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Dong Ma ◽  
Changwei Liu ◽  
Changhui Cheng
Keyword(s):  
Capillary Pressure ◽  
Relative Permeability ◽  
Pressure Data ◽  
Two Phase ◽  
Resistivity Index ◽  
Proposed Model ◽  
Petrophysical Parameter ◽  
Oil Water ◽  
Better Than ◽  
Good Agreement

Relative permeability as an important petrophysical parameter is often measured directly in the laboratory or obtained indirectly from the capillary pressure data. However, the literature on relationship between relative permeability and resistivity is lacking. To this end, a new model of inferring two-phase relative permeability from resistivity index data was derived on the basis of Poiseuille's law and Darcy's law. The wetting phase tortuosity ratio was included in the proposed model. The relative permeabilities computed from the capillary pressure data, as well as the experimental data measured in gas–water and oil–water flow condition, were compared with the proposed model. Both results demonstrated that the two-phase permeability obtained by proposed model were generally in good agreement with the data computed from capillary pressure and measured in the laboratory. The comparison also showed that our model was much better than Li model at matching the relative permeability data.

Spray deposition on plant surfaces: a modelling approach

2008 ◽  
Vol 35 (10) ◽  
pp. 988 ◽  
Author(s):  
Gary Dorr ◽  
Jim Hanan ◽  
Steve Adkins ◽  
Andrew Hewitt ◽  
Chris O'Donnell ◽  
...  
Keyword(s):  
Spray Deposition ◽  
Wild Oat ◽  
Leaf Stage ◽  
Sonchus Oleraceus ◽  
Wild Oats ◽  
Extended Range ◽  
Particle Trajectory Model ◽  
Plant Surfaces ◽  
Good Agreement ◽  
Flat Fan Nozzle

For pesticides to effectively manage pests, they must first be deposited on the target (typically a plant surface) in a manner in which the active ingredient(s) can be readily taken up by the target organism. A plant architectural model that enables the location of various plant components in 3-D space combined with a particle trajectory model has been used to study the interception of spray droplets by various vegetative elements. Results from the simulation are compared with wind tunnel studies of glyphosate deposition on cotton (Gossypium hirsutum L. var. Sicala), sow thistle (Sonchus oleraceus L.) and wild oats (Avena ludoviciana Durieu). An air induction flat fan nozzle (AI110015 at 500 kPa pressure) and an extended range flat fan nozzle (XR11002 at 280 kPa pressure) were predicted to have similar glyphosate deposition on cotton and sow thistle plants, whereas the extended range nozzle resulted in higher deposit on wild oats. Spray deposition (µg cm−2) on wild oat plants at the 5-leaf stage was more than double the amount of deposition on sow thistle or wild oat plants at the 2-leaf stage. The model was in good agreement with the experimental data except that it tended to over predict deposition on sow thistle plants.

Surface Temperatures and Dissociation Loss During the Pulsed Laser Annealing of GaAs

1983 ◽  
Vol 23 ◽  
Author(s):  
John T.A. Pollock ◽  
Alex Rose
Keyword(s):  
Laser Annealing ◽  
Pulsed Laser ◽  
Pressure Data ◽  
Incident Laser ◽  
Time Resolved ◽  
Dissociation Pressure ◽  
Pulsed Laser Annealing ◽  
Modelling Studies ◽  
Maximum Temperatures ◽  
Good Agreement

ABSTRACTFrom reported equilibrium partial and total dissociation pressure data for GaAs and melt times derived from reported time resolved reflectivity experiments, estimates have been made of the anticipated rate of As loss. Good agreement was found with experimentally determined As loss. A similar approach using experimentally determined Ga loss data allowed estimates of the maximum temperatures reached during pulsed laser annealing. These temperatures are considerably higher than suggested in thermal modelling studies. The boiling point of Ga gould be exceeded at incident laser energies >0.8 J cm−2.

STUDIES IN THE SYSTEM CALCIUM-OXIDE–SULPHUR-DIOXIDE–WATER: II. CALCULATION OF IONIC CONCENTRATIONS

1935 ◽  
Vol 13b (5) ◽  
pp. 308-322
Author(s):  
P. E. Gishler ◽  
O. Maass
Keyword(s):  
Vapor Pressure ◽  
Calcium Oxide ◽  
Sulphur Dioxide ◽  
Conductivity Data ◽  
Pressure Data ◽  
Vapor Pressure Data ◽  
Ionic Concentrations ◽  
Methods Of Calculation ◽  
Temperature And Pressure ◽  
Good Agreement

The conductivity and vapor pressure data of the system calcium-oxide–sulphur-dioxide–water presented in an earlier paper have been used to calculate ionic concentrations existing in this system, in the temperature and pressure range investigated. Two methods of calculation have been employed, one depending on the combination of vapor pressure and conductivity data, and the other, on conductivity data. For both, recourse was had to the data of Campbell and Maass on the system sulphur-dioxide–water. These methods gave results that are in good agreement with each other. The existence of a complex CaSO3.Ca(HSO3)2 was deduced.Hydrogen ion concentrations over the concentration and temperature range investigated have been calculated and extrapolations made to higher temperatures. These are presented in tabular form. Apart from the theoretical interest, it is pointed out that these results are of value in connection with studies of the delignification of wood by calcium-oxide–sulphur-dioxide–water solutions.

Assessment of Trawl Board and Anchor Penetration in Different Soils for Use in Selection of a Burial Depth to Protect Submarine Cables or Pipelines

2009 ◽  
Author(s):  
Se´bastien Resse´guier ◽  
Robert Bendzovski ◽  
Pa˚l Johannes Stro̸m ◽  
Harald Wathne ◽  
Maria Vigsnes ◽  
...  
Keyword(s):  
Soft Soil ◽  
Soft Clay ◽  
Soil Profiles ◽  
Burial Depth ◽  
Fishing Boat ◽  
Efficient Measure ◽  
Submarine Cables ◽  
Selection Of ◽  
Good Agreement ◽  
Different Soils

Burial of submarine pipelines, umbilicals and cables has proven to be an efficient measure for protection against trawling and anchoring. Since the 1980s, extensive burying of both existing and new submarine cables has lead to a considerably decrease in the number of failures and accidents. While in the available standards and recommended practice, no particular guidance can be found related to a safe burial depth in different soils, a number of studies have been carried out showing that a burial depth of 0.6m provides good protection against trawling and fishing activities in most soils. In the meantime, a demand has developed for even deeper burial depth, especially in soft soil in order to protect also against light fishing anchors. A review of the available literature has been carried out in order to determine the possible range of penetration of trawl board in different soils and under different conditions. This showed that the penetration remained limited whatever type of trawl gear or type of soil. In addition, calculations have been performed in order to assess the penetration of trawl boards with different sizes, weights and a range of soil strength. The results show a good agreement with the observed data, confirming that the penetration of trawl gear will be very limited in most clays with exception of very soft clay where excessive penetration can be expected. To assess anchor penetration, a software predicting the behaviour of drag embedment anchors during penetration in clay has been used. The maximum expectable penetration for different anchor sizes and soil profiles has been calculated and are presented in this paper. The results from these calculations also show that for most of the soils, the penetration of an anchor from a light fishing boat will be limited.

scholarly journals Behavior of Liquid Sodium in a Sinusoidal Pressure Field

1970 ◽  
Vol 92 (4) ◽  
pp. 671-678
Author(s):  
R. E. Nystrom ◽  
F. G. Hammitt
Keyword(s):  
Pressure Field ◽  
Saturation Temperature ◽  
Pressure Oscillation ◽  
Nucleate Boiling ◽  
Liquid Sodium ◽  
Pressure Amplitude ◽  
Pressure Data ◽  
Cavitation Threshold ◽  
Onset Of Cavitation ◽  
Good Agreement

Utilizing an ultrasonic vibratory cavitation facility, the onset of cavitation was observed in liquid sodium for different liquid sodium temperatures and at various sinusoidal pressure field frequencies. It was observed that the pressure oscillation required to initiate cavitation decreases linearly as the temperature of the sodium is increased from 500 to 1500 deg F. For frequencies below 20 kHz the cavitation threshold pressure amplitude is essentially independent of frequency. For frequencies above 20 kHz the cavitation threshold begins to increase sharply. Using the onset of cavitation data and the saturation temperature-pressure data for liquid sodium, the superheat required to produce nucleate boiling in liquid sodium was calculated. As the saturation temperature of liquid sodium is increased the calculated superheat decreases. For frequencies below 20 kHz the calculated sodium superheat requirements, which are independent of frequency, are in good agreement with steady-state sodium superheat data reported in the literature.

Predicting Shrinkage in Semi-Crystalline Injection Mouldings – The Influence of Pressure

2006 ◽  
Vol 514-516 ◽  
pp. 1501-1505 ◽  
Author(s):  
A.J. Pontes ◽  
António Sergio Pouzada
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Pressure Data ◽  
Melt Viscosity ◽  
Effect Of Pressure ◽  
Experimental Pressure ◽  
Pressure Evolution ◽  
Good Agreement

In this study, the as-moulded shrinkage and pressure data are obtained experimentally and compared with numerical simulations. The mouldings were produced in polypropylene (PP). The effect of pressure on viscosity in the predicted pressure evolution was analyzed and also its influence on the shrinkage. The results show that the rise of holding pressure determines the reduction of the shrinkage. Also, it was observed that the pressure predictions are qualitatively in good agreement with the experimental data. However noticeable quantitative discrepancies can be observed when the effect of pressure on viscosity is not considered. If the effect of pressure on the melt viscosity is considered the deviation between predicted and the experimental pressure evolution is substantially reduced.

Approximate Phase Change Solutions for Insulated Buried Cylinders

1983 ◽  
Vol 105 (1) ◽  
pp. 25-32 ◽  
Author(s):  
V. J. Lunardini
Keyword(s):  
Thermal Properties ◽  
Phase Change ◽  
Numerical Solutions ◽  
Single Point ◽  
Approximate Solutions ◽  
Burial Depth ◽  
Pipe Surface ◽  
Insulation Thickness ◽  
Theoretical Results ◽  
Good Agreement

The conduction problem for cylinders embedded in a medium with variable thermal properties cannot be solved exactly if phase change occurs. New, approximate solutions have been found using the quasi-steady method. These solutions consider heat flow from the entire pipe surface, rather than from a single point, as has been assumed in the past. The temperature field, phase change location, and pipe surface heat transfer can be evaluated using graphs presented for parametric ranges of temperature, thermal properties, burial depth, and insulation thickness. The theoretical results show good agreement with complete numerical solutions. The accuracy of the method increases as the Stefan number decreases and the results are of particular value for insulated hot pipes or refrigerated gas lines.

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