AN EXAMPLE OF THE INFLUENCE OF REMANENT MAGNETIZATION ON MAGNETIC INTENSITY MEASUREMENTS

Geophysics ◽  
1963 ◽  
Vol 28 (6) ◽  
pp. 1037-1048 ◽  
Author(s):  
Walter W. Hays ◽  
LeRoy Scharon
Keyword(s):  
Remanent Magnetization ◽  
Magnetic Measurements ◽  
Magnetic Intensity ◽  
Rock Unit ◽  
Total Magnetization ◽  
Intensity Measurements ◽  
Measured Profile ◽  
Magnetic Profile ◽  
The Individual ◽  
Rhyolitic Rock

Near Ironton, Missouri, measurements of the relative vertical intensity of the earth’s magnetic field were made along an 1,800‐ft line over an intrusive rhyolitic rock unit. Sharp variations of the order of 2,500 gammas were obtained along the sample line. These variations cannot be explained on the basis of induced magnetization alone. However, paleomagnetic measurements made on samples collected coincident to the line of magnetic measurements reveal great inhomogeneities in the magnetic properties: the magnetic susceptibility varies between [Formula: see text] and [Formula: see text] units; the ratio of the intensity of remanent magnetization to the intensity of induced magnetization varies from 0.21 to 26.91; the direction of remanent magnetization varies from sample to sample and is significantly different from the direction of the present geomagnetic field; and the polarity of the samples is both normal and reversed. A theoretical magnetic profile, calculated on the basis of the direction of total magnetization in the individual samples along the sample line, has the same gross features as the measured profile. The improved correlation which results upon consideration of the total magnetization properties of the rock unit emphasizes the necessity for considering the effects of remanent magnetization when interpreting magnetic intensity measurements.

scholarly journals Differences in the directions of ejection of x-ray photo-electrons from various atomic levels

1929 ◽  
Vol 126 (800) ◽  
pp. 138-143 ◽  
Keyword(s):  
Resolving Power ◽  
X Rays ◽  
Expansion Chamber ◽  
X Ray ◽  
Chamber Method ◽  
Heavy Atoms ◽  
Intensity Measurements ◽  
The Individual ◽  
Radio Corporation Of America ◽  
Slow Electrons

Very valuable studies of the directions in which photo-electrons are ejected by X-rays have been made recently by Williams, Auger, and Anderson. All of these observers, however, used the C. T. R. Wilson expansion-chamber method which, in spite of its power in working with the individual electron, suffers from the disadvantage that the particular energy level in the atom from which the electron is ejected in general cannot be determined. It is true that in the case of heavy atoms such as xenon and bromine, Auger and Anderson succeeded, through the use of X-rays of particular energies, in distinguishing the electrons thrown out of the K level from those thrown out of the L levels, but to go much further in this direction by the expansion-chamber method (and, for example, to distinguish the L I from the L II or L III electrons) seems hopeless. Consequently, the magnetic spectrograph developed by one of us for studying the velocity of the X-ray electrons as a function of the angle of emission was applied to the problem with the results which it is the purpose of this paper to describe. We, as yet, have not succeeded in determining the actual directions of ejection with the precision which has been attained in the expansion-chamber method, but the resolving power of the apparatus for velocities is so large that the particular level in which each electron group originates is in general quite unambiguous. A description of the apparatus used and the procedure followed has been given in the paper referred to above and need not be repeated here. Ballast lamps of the sort developed at the General Electric Company and sold by the Radio Corporation of America (radiotron UV-886) have proved very useful in holding the current through the solenoid which produces the magnetic field constant during the long exposures (100-200 hours) which are necessary. Eastman X-ray plates were used throughout, as they have been found to be the most sensitive of any so far tried (except Schumann plates which are much too irregular for intensity measurements). The work has been seriously handicapped by the lack of sensibility of the photographic plates for slow electrons and by their rapid falling off in sensibility for electrons of velocities below about 12,000 volts. X-ray tubes with silver, molybdenum and copper anticathodes were used. The characteristic radiation from copper is, however, in spite of its intrinsic intensity, too soft to eject electrons with sufficient velocity to give photographic results in a reasonable length of time with the apparatus used. All the results shown below consequently were obtained with the characteristic rays of either silver or molybdenum.

COMPUTER SYSTEMS FOR REAL‐TIME MARINE EXPLORATION

Geophysics ◽  
1973 ◽  
Vol 38 (2) ◽  
pp. 301-309 ◽  
Author(s):  
E. K. Darby ◽  
E. J. Mercado ◽  
R. M. Zoll ◽  
J. R. Emanuel
Keyword(s):  
Real Time ◽  
Seismic Data ◽  
Magnetic Tape ◽  
Single Channel ◽  
Magnetic Measurements ◽  
Data Gathering ◽  
Time Of Day ◽  
Magnetic Profile ◽  
Multichannel Seismic Data ◽  
Marine Exploration

The goals of the Gulfrex are to perform marine exploration and to conduct research and development in the various facets of marine exploration. The Gulfrex is equipped with various geologic and geophysical data‐gathering instruments along with a highly sophisticated navigational package. Computerized control systems were designed to output data in real time so that preliminary interpretations could be made concurrently with data collection. One system, based on an EMR‐6130 computer, handles multichannel seismic data. This system includes routines for real‐time demultiplexing, normal moveout, stacking, and deconvolution. Output of demultiplexed data is to magnetic tape and optionally to paper records. Output of moveout‐corrected, stacked data is to a visual monitor and to magnetic tape via a PDP‐8 computer. Deconvolution may be applied to either the single‐channel traces or the stacked traces. A moveout‐corrected, CDP group is output to a paper record every 24 shots so that estimates of average velocities can be made for a normal‐moveout correction. Another system, designed for a PDP‐8 computer, is used to collect data from devices interfaced to it. These include single‐channel seismic data, gravity and magnetic measurements, and navigational measurements such as course, speed, ship position, and direction. Deconvolved single‐channel seismic data are plotted in real time on a visual monitor along with a corrected gravity profile, magnetic profile, speed, course, and time of day. A map of the ship’s course is plotted in real time on a drum plotter Inquiries may be made of the system for current position in latitude and longitude.

scholarly journals Investigations of magne-crystallic action. Part II.-Paramagnetics

1933 ◽  
Vol 232 (707-720) ◽  
pp. 99-115 ◽  
Keyword(s):  
Magnetic Measurements ◽  
Energy Levels ◽  
Magnetic Behaviour ◽  
Point Of View ◽  
Diamagnetic Anisotropy ◽  
Direct Measurements ◽  
Intrinsic Anisotropy ◽  
Atomic Energy Levels ◽  
The Individual ◽  
Van Vleck

In Part I we gave an account of some magnetic measurements on diamagnetic crystals. It is found that the diamagnetic anisotropy of a crystal can be satisfactorily explained in terms of the intrinsic anisotropy of the individual molecules (or ions) constituting it and their relative orientations. Thus by a study of the magnetic properties of diamagnetic crystals much useful information can be obtained regarding the anisotropies of molecules and their orientations in the crystal lattice. The study of paramagnetic crystals is also of great interest, but for other reasons. Here the crystal-forces play an all-important part in determining their anisotropy, as opposed to diamagnetic crystals where the influence of crystal structure is indirect, and appears only so far as it determines the relative orientations of the molecules. The recent work of BETHE on the Stark-splitting of the energy levels of a paramagnetic ion in a crystal, under the influence of the crystalline forces, and the discussions by VAN VLECK , and by PENNEY and SCHLAPP about the effect of this splitting on the magnetic behaviour of the ion, throw considerable light on the origin of the magnetic anisotropy in a paramagnetic crystal. From the point of view of these newer theories, especially in consideration of our present incomplete knowledge regarding atomic energy levels in crystals, extensive data on the anisotropies of paramagnetic crystals would be useful. The present paper describes the results of some direct measurements on anisotropy for a number of crystals.

scholarly journals Hydrodynamic properties of human cervical-mucus glycoproteins in 6m-guanidinium chloride

1984 ◽  
Vol 217 (1) ◽  
pp. 93-101 ◽  
Author(s):  
J K Sheehan ◽  
I Carlstedt
Keyword(s):  
Sedimentation Coefficient ◽  
Large Degree ◽  
Correlation Spectroscopy ◽  
Radius Of Gyration ◽  
Random Coils ◽  
Intensity Measurements ◽  
Hydrodynamic Behaviour ◽  
Stokes Radius ◽  
The Individual ◽  
The Relationship

Cervical mucins and fragments thereof were studied by sedimentation-velocity, rotatory viscometry and laser light-scattering performed as photon-correlation spectroscopy as well as low-angle total-intensity measurements. The Mr of the whole mucins is 10 × 10(6)-15 × 10(6), whereas fragments obtained after reduction of disulphide bonds (‘subunits’) have Mr 2.1 × 10(6)-2.9 × 10(6), depending on the method used. Subsequent trypsin digestion of subunits afforded glycopeptides with Mr approx. 0.4 × 10(6). The high frictional ratio for the whole mucins is interpreted as a large degree of expansion. The Stokes radius calculated from the diffusion coefficient is approx. 110nm for the whole mucins, which is in agreement with that estimated from the radius of gyration (130nm) by using the concept of the equivalent hydrodynamic sphere. The ratio of the concentration-dependence parameter for the reciprocal sedimentation coefficient (Ks) to the intrinsic viscosity ([eta]) for the whole mucins is 1.42, suggesting that the individual macromolecule occupies a spheroidal domain in solution. The relationship between [eta] and Mr for whole mucins, subunits and T-domains suggests that they are linear flexible macromolecules behaving as somewhat ‘stiff’ random coils. This conclusion is supported by the relationships between the sedimentation coefficients, the diffusion coefficients and the Mr. The hydrodynamic behaviour of the mucins is thus close to that expected for coiling macromolecules entrapping a lot of solvent, which is consistent with the postulated polymeric structure.

A New Method of Cross-Correlation by Magnetic Dipole for Estimating Magnetization Direction under the Influence of Remanent Magnetization

2014 ◽  
Vol 644-650 ◽  
pp. 3459-3462 ◽  
Author(s):  
Lei Shi ◽  
Liang Hui Guo ◽  
Feng Yi Guo
Keyword(s):  
Correlation Coefficient ◽  
Magnetic Dipole ◽  
Remanent Magnetization ◽  
Cross Correlation ◽  
New Method ◽  
Magnetic Data ◽  
Dipole Source ◽  
Total Field ◽  
Magnetization Direction ◽  
Total Magnetization

Processing and interpretation of magnetic data usually require information of total magnetization direction. However, under the effects of remanent magnetization, total magnetization direction is different from induced magnetization direction, which makes data processing and interpretation complexity. In this paper, we present a new method by cross-correlation of magnetic dipole source for determination of magnetization direction from relatively isolated and approximate equiaxial-shape magnetic total field anomaly. This method calculates cross-correlation coefficient between observed magnetic total field anomaly and theoretical magnetic total field anomaly caused by a magnetic dipole source, by using a set of varying parameters of positions and total magnetization direction of dipole source for trial and error. The corresponding magnetization direction of maximum correlation coefficient is regarded as estimated total magnetization direction. Test on synthetic data indicates that this method reliably and effectively estimates the magnetization direction from relatively isolated and approximate equiaxial-shape magnetic total field anomaly.

Estimating the Magnetization Direction of Sources through Correlation between Reduced-to-Pole Anomaly and Normalized Source Strength

2014 ◽  
Vol 644-650 ◽  
pp. 3793-3796
Author(s):  
Liang Hui Guo ◽  
Rui Gao ◽  
Guo Li Zhang
Keyword(s):  
Geomagnetic Field ◽  
Remanent Magnetization ◽  
Cross Correlation ◽  
Synthetic Data ◽  
Field Direction ◽  
Magnetic Data ◽  
Source Strength ◽  
Magnetization Direction ◽  
New Approach ◽  
Total Magnetization

Under the effects of remanent magnetization, total magnetization direction is different from geomagnetic field direction, which makes magnetic data processing and interpretation complexity. In this paper, we present a new approach for estimating the total magnetization direction of sources via cross-correlation between the reduced-to-pole anomaly and the normalized source strength (who is less sensitive to remanent magnetization). The geomagnetic field direction is used to calculated the normalized source strength, while various assumed total magnetization directions are used to calculated the RTP anomalies. The maximum correlation between the RTP anomalies and the normalized corresponds to the estimated total magnetization direction. Test on synthetic data showed that the new approach is simple and effective.

PALAEOMAGNETISM OF DIABASE DYKES OF THE CANADIAN SHIELD

1965 ◽  
Vol 2 (4) ◽  
pp. 278-298 ◽  
Author(s):  
W. F. Fahrig ◽  
E. H. Gaucher ◽  
A. Larochelle
Keyword(s):  
Remanent Magnetization ◽  
Lake Superior ◽  
Canadian Shield ◽  
Igneous Rocks ◽  
Palaeomagnetic Data ◽  
The World ◽  
Oriented Samples ◽  
The Mean ◽  
The Individual ◽  
Dyke Swarms

Some areas of the Canadian Shield are profusely intruded by swarms of subparallel basaltic dykes. These typically have a diabasic texture and formerly were considered to be strictly the intrusive equivalents of tholeiitic flood basalt.About 650 oriented samples were collected from about 25 dyke swarms and preliminary palaeomagnetic data from six of them are presented here. The Mackenzie swarm has a K–Ar age of 1 295 million years, occurs throughout the western Canadian Shield, and is the most extensive swarm of basic dykes known anywhere in the world. The other swarms are the Molson dykes (1 445 m.y.) in northeastern Manitoba, the Marathon dykes (1 810 m.y.) just north of Lake Superior, the Sudbury dykes (1 285 m.y.) of southeastern Ontario, the Matachewan dykes (2 485 m.y.) of western Quebec and northeastern Ontario, and the Abitibi dykes (1 230 m.y.), which occur from Sault Ste. Marie, Ontario, to Lake Mistassini, Quebec.The palaeomagnetic virtual pole positions of six swarms were derived from the mean of their measured remanent magnetization directions. These directions of magnetization were determined from the samples after they were magnetically washed in an a-c. field of 80 or 130 oersteds. The reasons for the dispersion within the individual swarms are discussed. The pole positions of the Sudbury and Mackenzie dykes are almost identical and the two swarms are the same age within the limits of analytical uncertainty. However, basalt of the Sudbury swarm is alkalic and more undersaturated than basalt of the Mackenzie dykes.No evidence was found to contradict the usual assumption that unaltered basic igneous rocks of this type acquire and generally retain a stable magnetization which was parallel with the earth's magnetic field at the time of the dyke intrusion.

scholarly journals The crystalline structure of anthracene. A quantitative X-ray investigation

1933 ◽  
Vol 140 (840) ◽  
pp. 79-98 ◽  
Keyword(s):  
Organic Compounds ◽  
Aromatic Hydrocarbons ◽  
Magnetic Measurements ◽  
Upright Position ◽  
Ray Method ◽  
Tetrahedral Structure ◽  
X Ray ◽  
Intensity Measurements ◽  
Graphite Structure ◽  
Absolute Measurements

The aromatic hydrocarbons naphthalene and anthracene were among the first organic compounds to be investigated by the X-ray method. The early work on these crystals afforded evidence that the long axes of the molecules lay along the c direction in the crystal, but less definite indication was obtained regarding the lateral disposition of the molecules. An attempt was made to settle this point by a study of the intensities of the principal X-ray reflections by visual estimate, and this led to a distorted “tetrahedral” structure being advanced. Somewhat later it was shown by Sir William Bragg that this structure was untenable, the discrepancies between the calculated and the measured values of certain reflections being too great. In this work absolute measurements of intensity were obtained for the more important planes, and the evaluation of the atomic positions carried out by Fourier analysis. This led to a structure consisting of molecules with flat or slightly distorted carbon rings, whose planes made an angle of about 25° with the bc plane, and with the long axis of the molecule tilted about 6° away from the direction of the c axis towards a more upright position. Almost at the same time Banerjee independently arrived at a structure, based upon the measurement of some intensities, together with the results of optical and magnetic measurements, which agreed very closely with Bragg’s structure. At the commencement of the present work, then, it could be taken that the structure of anthracene was approximately known. It was very important, however, to confirm these results by more accurate and more extensive intensity measurements, and also to attempt to work out the finer details of the structure. For example, it was not known if the carbon rings were quite flat like the graphite structure, or slightly puckered, perhaps intermediate between the diamond and graphite type: the evidence seemed to point to the latter possibility. The carbon to carbon distance was not accurately known. The only estimate obtained was 1⋅48 A., which is again intermediate between the diamond (1⋅54) and the graphite (1⋅42) distance.

scholarly journals Size heterogeneity of human cervical mucus glycoproteins. Studies performed with rate-zonal centrifugation and laser light-scattering

1987 ◽  
Vol 245 (3) ◽  
pp. 757-762 ◽  
Author(s):  
J K Sheehan ◽  
I Carlstedt
Keyword(s):  
Light Scattering ◽  
Laser Light ◽  
Laser Light Scattering ◽  
Correlation Spectroscopy ◽  
Radius Of Gyration ◽  
Intensity Measurements ◽  
The Individual ◽  
Size Heterogeneity ◽  
Mucus Glycoproteins ◽  
Good Agreement

Mucus glycoproteins (mucins) from cervical pregnancy mucus were fractionated by using rate-zonal centrifugation in a gradient of guanidinium chloride. The distribution of the macromolecules, as assessed by using sialic acid determination, suggested the presence of three populations of different size. Individual fractions were subjected to laser light-scattering performed as total-intensity measurements as well as photon correlation spectroscopy. The results showed that points of inflexion were present in the distribution of both Mr and DT (translational diffusion coefficient) and that the three populations have Mr values of approx. 24 × 10(6), 16 × 10(6) and 6 × 10(6) respectively. The weight-average Mr for the whole distribution, as calculated from the values obtained for the individual fractions, was 13.6 × 10(6), which is in good agreement with that found for the unfractionated material (11.1 × 10(6]. Plots of log RG (radius of gyration) and log (1/DT) versus log Mr are in keeping with the macromolecules being linear flexible chains.

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