The Determination of the Thermal History in a One-Dimensional Freezing System by a Perturbation Method

1979 ◽  
Vol 101 (2) ◽  
pp. 326-330 ◽  
Author(s):  
B. Rubinsky ◽  
E. G. Cravalho
Keyword(s):  
Perturbation Method ◽  
Thermal History ◽  
Complex Shape ◽  
Time History ◽  
One Dimension ◽  
Phase Front ◽  
Cooling Rates ◽  
One Dimensional ◽  
History Of

A perturbation method is employed to determine the thermal history of a biological organ frozen with a constant cooling rate at its outer surface. Solutions were obtained for the time history of the propagating phase front and the distribution of cooling rates within the organ. By means of a one-dimensional analysis, a new dimensionless group has been found to correlate the range of cooling rates in a frozen organ of complex shape. The analytical model has been confirmed by experimental measurements on a one-dimensional freezing system. The results of this treatment are useful in the design and analysis of experiments dealing with freezing in one dimension, particularly in the preservation of organs by freezing.

scholarly journals OIL AND GAS MODELING GENERARION IN THE JURASSIC SEDIMENTS IN THE SOUTH-EASTERN OF THE WEST SIBERIAN PETROLEUM PROVINSE

2021 ◽  
Vol 2 (1) ◽  
pp. 38-43
Author(s):  
Elena A. Glukhova ◽  
Pavel I. Safronov ◽  
Lev M. Burshtein
Keyword(s):  
Heat Flow ◽  
Thermal History ◽  
Oil And Gas ◽  
Flow Density ◽  
Basin Modeling ◽  
Heat Flow Density ◽  
The West ◽  
One Dimensional ◽  
History Of ◽  
The One

The article presents the one-dimensional basin modeling performed in four wells to reconstruct the thermal history of deposits and reconstruct the effective values of the heat flow density.

Experimental Evidence of Ca Segregation to Antiphase Boundaries in Pigeonite

2001 ◽  
Vol 7 (S2) ◽  
pp. 254-255
Author(s):  
KT Moore ◽  
DR Veblen ◽  
JM Howe
Keyword(s):  
Experimental Evidence ◽  
Thermal History ◽  
Igneous Rocks ◽  
Cooling History ◽  
Antiphase Boundaries ◽  
Cooling Rates ◽  
History Of ◽  
Antiphase Domains

For over 30 years geologists have been trying to better understand antiphase domains (APD) and boundaries (APB) in pigeonite in hopes of using them as markers for the thermal history of the rocks in which they are found. The ability to know the cooling history of igneous rocks is of great interest to geologists and pigeonite has received special attention on this matter because it has exsolution (precipitation) and antiphase domains (APD), both of which can be used as possible thermal markers. APDs in pigeonite arise because of the C2/c → P21/c transformation that occurs upon cooling. When multiple APDs nucleate, grow, and impinge upon one another, they are either in registry or have a translational discrepancy of ½(a+b). The size of the APDs can be used as a qualitative marker of cooling rates, since slowly cooled pigeonites favor large APDs and rapidly cooled pigeonites favor small APDs.

scholarly journals Tracking patchy pulsating aurora through all-sky images

2017 ◽  
Vol 35 (4) ◽  
pp. 777-784 ◽  
Author(s):  
Eric Grono ◽  
Eric Donovan ◽  
Kyle R. Murphy
Keyword(s):  
Time History ◽  
Image Data ◽  
Auroral Oval ◽  
Automatic Identification ◽  
Inner Magnetosphere ◽  
Wide Range ◽  
History Of ◽  
Initial Results ◽  
Automatic Technique

Abstract. Pulsating aurora is frequently observed in the evening and morning sector auroral oval. While the precipitating electrons span a wide range of energies, there is increasing evidence that the shape of pulsating auroral patches is controlled by structures in near-equatorial cold plasma; these patches appear to move with convection, for example. Given the tremendous and rapidly increasing amount of auroral image data from which the velocity of these patches can be inferred, it is timely to develop and implement techniques for the automatic identification of pulsating auroral patch events in these data and for the automatic determination of the velocity of individual patches from that data. As a first step towards this, we have implemented an automatic technique for determining patch velocities from sequences of images from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) all-sky imager (ASI) and applied it to many pulsating aurora events. Here we demonstrate the use of this technique and present the initial results, including a comparison between ewograms (east–west keograms) and time series of patch position as determined by the algorithm. We discuss the implications of this technique for remote sensing convection in the inner magnetosphere.

An assessment of results obtained from Mössbauer spectra of lunar samples

1977 ◽  
Vol 285 (1327) ◽  
pp. 235-240 ◽  
Keyword(s):  
Thermal History ◽  
Major Constituent ◽  
Iron Particles ◽  
Surface Layers ◽  
Significant Evidence ◽  
Geological Features ◽  
Lunar Samples ◽  
History Of ◽  
Detailed Determination

Most of the minerals on the Moon’s surface contain iron as a major constituent, and this enables them to be examined by Mossbauer spectroscopy. The advantages and limitations of this technique for examining lunar samples will be briefly mentioned, before reviewing the results so far obtained on material returned by the Apollo and Luna missions. By far the greatest proportion of iron is present as Fe(II) or Fe(0), and no appreciable concentration of Fe(III) has been observed. The relative amounts of iron-containing minerals at the various lunar sites have been determined and related to the lunar geological features. The more detailed determination of the distribution of iron between the M1 and M2 sites in pyroxene minerals leads to information on the thermal history of the rocks. Likewise the presence of superparamagnetic iron particles within the surface layers of some of the soil particles provides significant evidence concerning their origin and subsequent history.

scholarly journals Advanced calibration of magnetometers on spin-stabilized spacecraft based on parameter decoupling

2019 ◽  
Vol 8 (1) ◽  
pp. 63-76 ◽  
Author(s):  
Ferdinand Plaschke ◽  
Hans-Ulrich Auster ◽  
David Fischer ◽  
Karl-Heinz Fornaçon ◽  
Werner Magnes ◽  
...  
Keyword(s):  
Time History ◽  
Field Measurements ◽  
Incorrect Choice ◽  
University Of Technology ◽  
Solar System Bodies ◽  
History Of ◽  
Determination Of Parameters ◽  
Calibration Equations ◽  
Calibration Parameters

Abstract. Magnetometers are key instruments on board spacecraft that probe the plasma environments of planets and other solar system bodies. The linear conversion of raw magnetometer outputs to fully calibrated magnetic field measurements requires the accurate knowledge of 12 calibration parameters: six angles, three gain factors, and three offset values. The in-flight determination of 8 of those 12 parameters is enormously supported if the spacecraft is spin-stabilized, as an incorrect choice of those parameters will lead to systematic spin harmonic disturbances in the calibrated data. We show that published equations and algorithms for the determination of the eight spin-related parameters are far from optimal, as they do not take into account the physical behavior of science-grade magnetometers and the influence of a varying spacecraft attitude on the in-flight calibration process. Here, we address these issues. Based on decade-long developments and experience in calibration activities at the Braunschweig University of Technology, we introduce advanced calibration equations, parameters, and algorithms. With their help, it is possible to decouple different effects on the calibration parameters, originating from the spacecraft or the magnetometer itself. A key point of the algorithms is the bulk determination of parameters and associated uncertainties. The lowest uncertainties are expected under parameter-specific conditions. By application to THEMIS-C (Time History of Events and Macroscale Interactions during Substorms) magnetometer measurements, we show where these conditions are fulfilled along a highly elliptical orbit around Earth.

The optical determination of preferred orientation in clays and its application to the study of microstructure in consolidated kaolin. ІІ

1967 ◽  
Vol 300 (1461) ◽  
pp. 235-250 ◽  
Keyword(s):  
Preferred Orientation ◽  
Optical Data ◽  
Initial Structure ◽  
Clay Particles ◽  
One Dimensional ◽  
History Of ◽  
Optical Determination ◽  
The Individual ◽  
Water Contents

The degree of preferred orientation and fabric homogeneity of a clay depend upon its method of preparation and subsequent history of loading. The degree of preferred orientation can be determined by measuring the birefringence ratio for a thin section of clay. When the fabric is homogeneous this value is shown to be independent of the area observed. For a fabric composed of packets containing oriented clay particles a representative value of birefringence ratio for the bulk clay may be obtained by measuring over an area large in comparison with the size of the individual packet. In order to study the development of preferred orientation in a kaolin subject to one-dimensional consolidation, birefringence ratio measurements have been obtained for specimens prepared by sedimentation with both a flocculating and deflocculating pore fluid. Significant differences were observed in the initial structure. When loaded beyond 0.1 ton / ft. 2 the optical data indicated little difference in the preferred orientation of these clays. This was corroborated by the near identity of both compressibility and permeability at particular pressures beyond this level. The birefringence ratio measurements show that for flocculated kaolin prepared by sedimentation the development of intense orientation in this test is virtually complete at a stress level of 0-1 ton /ft. 2 . Microscopic observations of the initial structure of kaolin remoulded at different water contents and with different pore fluids revealed the presence of packets composed of parallel particles. The consolidation of these clays was studied and shown to be strongly influenced by the mobility of these packets. Reconsolidation parallel to the direction of preferred orientation does not materially alter the fabric for the range of stresses considered here.

Time Dependent FLC Determination Comparison of Different Algorithms to Detect the Onset of Unstable Necking before Fracture

2013 ◽  
Vol 549 ◽  
pp. 397-404 ◽  
Author(s):  
Walter Hotz ◽  
Marion Merklein ◽  
Andreas Kuppert ◽  
Harald Friebe ◽  
Markus Klein
Keyword(s):  
Correlation Coefficient ◽  
Work Group ◽  
Time History ◽  
Time Dependent ◽  
Forming Limit ◽  
Iso Standard ◽  
Modified Method ◽  
History Of ◽  
Forming Limit Curves

The ISO standard 12004-2:2008E for the determination of forming limit curves based on the section method was approved in 2008. About 4 years of measuring experience in different laboratories has shown advantages and weaknesses of the standard and is leading to some minor changes in the specification. In the years from the development of this standard until today a further technical development of the optical measuring devices occurred, so that it is now possible to determine forming limit curves using the time history of the test. This procedure of determination is referred to a time dependent technique and could be the basis of the ISO 12004 part 2 proposal worked out by the work group Erweiterung FLC ISO 12004 of the German group of the IDDRG. This publication recapitulates existing work which was carried out from the IDDRG work group regarding the determination of forming limit curves for sheet metal materials. On one hand known issues with the current section based approach are discussed and on the other hand it deals with a comparison of different algorithms to determine the FLC from the time history of the Nakajima test using strategies to identify the instant of onset of instable necking. The different time dependent algorithms [ utilised are automatically selecting the area where necking is leading to fracture and then analyze the time history of such points using the first or the second time derivative of the true major strain, or of the true thinning strain using methods like: correlation coefficient (modified method based on [2]), gliding correlation coefficient, linear best fit (modified method based on [3]) and gliding difference of mean to median. The resulting experimental FLC points are compared with the results from the section technique described in ISO 12004 part 2 and with the maximum strain values measured in each test. Further a large number of forming limit curves were determined and used for a comparison of these different methods to define the most promising time dependent algorithm, which was selected as a suggestion for the working group defining the new proposed ISO standard 12004 part 2.

scholarly journals 4. On the Early Thermal History of Chondritic Asteroids Derived by 244-Plutonium Fission Track Thermometry

1977 ◽  
Vol 39 ◽  
pp. 355-363 ◽  
Author(s):  
P. Pellas ◽  
D. Storzer
Keyword(s):  
Thermal History ◽  
Fission Track ◽  
Refractory Materials ◽  
Cooling Curves ◽  
Ordinary Chondrites ◽  
Cooling Rates ◽  
Track Record ◽  
History Of

Cooling curves were determined for ordinary chondrites within the time- and temperature intervals from ~4.6 to ~4.1 × 109 years and ~1400 K to 300 K respectively. This was done by analyzing the 244-plutonium fission track record in whitlockite and adjacent mineral track detectors. The resulting cooling rates constrain the sizes of the parent asteroids to ~120 - 200 km in radius. These dimensions together with the fact that chondrites had never been molten, suggest lower 26Al/27Al initial ratios for ordinary chondritic than for Allende refractory materials.

SIMS Pb–Pb and U–Pb age determination of eucrite zircons at<5μm scale and the first 50Ma of the thermal history of Vesta

2013 ◽  
Vol 110 ◽  
pp. 152-175 ◽  
Author(s):  
Qin Zhou ◽  
Qing-Zhu Yin ◽  
Edward D. Young ◽  
Xian-Hua Li ◽  
Fu-Yuan Wu ◽  
...  
Keyword(s):  
Thermal History ◽  
Age Determination ◽  
History Of

Geo History, Thermal History and Hydrocarbon Generation History of the Northern North Sea Basin

1987 ◽  
Vol 5 (4) ◽  
pp. 315-355 ◽  
Author(s):  
Song Cao ◽  
Ian Lerche
Keyword(s):  
Fluid Flow ◽  
North Sea ◽  
Thermal History ◽  
Hydrocarbon Exploration ◽  
Geochemical Data ◽  
Hydrocarbon Generation ◽  
Similar Data ◽  
History Of ◽  
Northern North Sea

A one-dimensional, fluid flow/compaction model has been developed for petroleum explorationists to make quantitative studies of sedimentary basins. The following results can be obtained from the model: (1) basement subsidence (sediment load and tectonic effect); (2) structural evolution; (3) determination of erosion thickness of an unconformity; (4) changes of porosity, permeability, fluid flow rate and pore pressure with time and depth; (5) heat flow history; (6) temperature change with time and depth; (7) the value of thermal maturity indicators which change with time and depth; (8) hydrocarbon generation history including time and depth of peak hydrocarbon generation; and (9) prediction of possible directions of hydrocarbon migration and accumulation with time. The model is applicable to both frontier basins where only a few wells have been drilled and also to well-developed basins. The input data for the model are based mainly on commonly used geological and geochemical data from one well in a frontier basin or on similar data from many wells in a well-developed basin. Fifty-eight wells in the northern North Sea Basin have been used to reconstruct the geohistory, thermal history and hydrocarbon generation and migration history of the northern North Sea. The results accurately conformed to the well data, allowing determination of hydrocarbon generation amounts, migration times and accumulation sites, which are helpful for further hydrocarbon exploration in the northern North Sea Basin.

Sign in / Sign up

Export Citation Format

Share Document