ANALYSIS FOR MAGNETITE UTILIZING MAGNETIC SUSCEPTIBILITY

Geophysics ◽  
1966 ◽  
Vol 31 (2) ◽  
pp. 398-409 ◽  
Author(s):  
P. D. Shandley ◽  
L. O. Bacon

The analysis for magnetite or “magnetite equivalent” by means of magnetic susceptibility is more rapid, lower in cost, and in general, as precise as other methods of analysis. “Magnetite equivalent” analysis is affected by grain size if the individual particles are less than 40 microns in diameter, by the remnant magnetization if greater than about 12 percent of saturation magnetization, and by the presence of other magnetic minerals. The presence of other magnetic minerals does not reflect as great an error in the final result using the susceptibility method as in other methods. Davis tube separation as a method for magnetite analysis is affected by other magnetic minerals but is mainly dependent upon degree of mineral liberation by grinding. Chemical analysis with the subsequent calculation of magnetite content is in error due to presence of other iron‐bearing minerals whether magnetic or nonmagnetic and is particularly affected by the presence of metallic iron from sample preparation. Metallic iron apparently enters solution by the following reaction: [Formula: see text] Thus, one unit of metallic iron would be counted as approximately 12 units of magnetite in the calculation of magnetite content. Analysis for “magnetite equivalent” and chemical analysis for total soluble iron can provide an accurate evaluation of the amount of nonmagnetic iron in any particular ore, especially in mixed magnetite‐hematite ores. Equipment for direct readout of grams magnetite per 100 cc was designed using the differential transformer principle. Calibration is linear below 20 grams magnetite per 100 cc, and measurement of apparent density of sample readily converts the readings to percent magnetite by weight.

Geophysics ◽  
1953 ◽  
Vol 18 (2) ◽  
pp. 383-393 ◽  
Author(s):  
Harold M. Mooney ◽  
Rodney Bleifuss

75 samples of 7 rock types have been analyzed for magnetite content by magnetic separation and chemical analysis, making allowance for iron which occurs as ilmenite, hematite, and silicates. Magnetic susceptibility shows a clear dependence on magnetite content but with too much scatter to permit prediction of one from the other. For small magnetite content V (in volume percent), susceptibility k is roughly given by [Formula: see text] cgs. Based on 200 outcrops of 11 rock types, the approximate mean susceptibility of basalt and diabase is [Formula: see text], of rhyolite and gabbro [Formula: see text], of acid intrusives including granite [Formula: see text], of greenstone [Formula: see text], and of slates [Formula: see text]. Variability is high for acid intrusives, intermediate for basalt, rhyolite, and greenstone, and lower for diabase, gabbro, and slate.


2021 ◽  
Vol 118 (47) ◽  
pp. e2112749118
Author(s):  
Robert W. de Gille ◽  
Julia M. McCoey ◽  
Liam T. Hall ◽  
Jean-Philippe Tetienne ◽  
E. Pascal Malkemper ◽  
...  

The ability of pigeons to sense geomagnetic fields has been conclusively established despite a notable lack of determination of the underlying biophysical mechanisms. Quasi-spherical iron organelles previously termed “cuticulosomes” in the cochlea of pigeons have potential relevance to magnetoreception due to their location and iron composition; however, data regarding the magnetic susceptibility of these structures are currently limited. Here quantum magnetic imaging techniques are applied to characterize the magnetic properties of individual iron cuticulosomes in situ. The stray magnetic fields emanating from cuticulosomes are mapped and compared to a detailed analytical model to provide an estimate of the magnetic susceptibility of the individual particles. The images reveal the presence of superparamagnetic and ferrimagnetic domains within individual cuticulosomes and magnetic susceptibilities within the range 0.029 to 0.22. These results provide insights into the elusive physiological roles of cuticulosomes. The susceptibilities measured are not consistent with a torque-based model of magnetoreception, placing iron storage and stereocilia stabilization as the two leading putative cuticulosome functions. This work establishes quantum magnetic imaging as an important tool to complement the existing array of techniques used to screen for potential magnetic particle–based magnetoreceptor candidates.


1989 ◽  
Vol 44 (11) ◽  
pp. 1063-1078 ◽  
Author(s):  
H. Krause ◽  
D. H. Sutter

Abstract The rotational Zeeman effect has been observed in methanimine which was produced from ethylenediamine by flash pyrolysis. The observed vibronic ground state expectation values of the molecular g-values, the magnetic susceptibility anisotropies and the molecular electric quadrupole moments are: gaa = -1.27099(22), gbb= -0.18975(7), gcc= -0.03440(8), 2ξaa-ξbb-ξcc = 12.49(19) · 10-6 ergG-2mol-1, 2ξbb-ξcc-ξaa = 5.22(11) · 10-6 ergG-2 mol-1 Qaa = 0.43(17) · 10-26esu cm2, Qbb= 1.08(10) · 10-26 esu cm2, and Qcc= -1.51 (26) . 10-26 esu cm2. With the TZVP ab initio value for the out-off plane electronic second moment as additional input, reliable values can be given also for the individual components of the magnetic susceptibility tensor and for the bulk susceptibility:ξ = (ξaa + ξbb + ξcc)/3=-13.13(88) · 10-6 erg G -2 mol-1. From low-J a-and b-type zero field transitions the spin-rotation coupling constants and the 14N nuclear quadrupole coupling constants could be redetermined with improved accuracy. These data are compared with our new theoretical results.


1988 ◽  
Vol 137 ◽  
Author(s):  
Hamlin M. Jennings

Cement paste of water:cement ratios less than about 0.3 usually are not workable, but workability can be maintained at these lower water:cement ratios by using superplasticizers. A typical explanation [1] of the mechanism behind the effectiveness of superplasticizers is that they adsorb on the surface of cement particles and adjust the surface charge so that the particles become deflocculated. The individual particles flow more easily than larger flocs.


2021 ◽  
Vol 7 (3) ◽  
pp. 381
Author(s):  
Dini Fitriani ◽  
Widya Utami ◽  
Kartika Hajar Kirana ◽  
Eleonora Agustine ◽  
Siti Zulaikah

A number of activities occur around the Cikijing River in Rancaekek area, West Java, such as industrial and domestic activities. The various activities could decrease the quality of the river and surrounding environment due to anthropogenic pollutants that might be produced. Since the Cikijing River is also used as the source of irrigation, paddy fields around the river could be also be affected. The presence of pollutants in river sediments and agricultural soils over a long period could change their magnetic properties. Magnetic susceptibility of Cikijing River sediments and soils of the paddy fields in the surrounding have been examined considering that magnetic properties could represent environmental conditions. The results show that river sediments have magnetic susceptibility (cLF) in range of 356.2-456.3 (×10-8) m3kg-1, whereas soils samples have cLF varying from 94.1 to 347.1 (×10-8) m3kg-1, suggesting domination of ferrimagnetic minerals. The cFD (%) is <4% indicating the anthropogenic origin of magnetic minerals.  Electron microscopy images show the imperfect octahedral and spherules shapes of magnetic grains that supports magnetic susceptibility analysis about the source of magnetic minerals. Elemental composition analysis reveals Fe and O’s content as main elements, including minor elements of Ca, Mg, Al. Si, Ti and Cr


The proofs of the no-interaction theorem have been given by many authors in the framework of hamiltonian and lagrangian formalism. They are based on the assumption that there is hamiltonian or lagrangian describing the interaction between particles. This paper presents the proof without such an assumption for one, two, three and four particles. We assume the conservation laws for the linear and angular momentum that are the sums of the respective quantities of individual particles. Then there is no interaction, i. e. the worldlines of the individual particles are straight.


When a beam of electric particles is passed through a sheet of matter the energy of the individual particles is reduced. The loss of energy is not the same for all the particles so that particles incident on the foil with the same energy emerge with different energies. This dispersion of the energy caused by the foil is known as the "straggling" of the particles. The straggling of α-particles has been the subject of several experimental investigations, and the theory in this case was adequately developed by Bohr in 1915. In the case of β-particles, however, the straggling was not experimentally investigated until quite recently and no theoretical treatment of the phenomenon has been given, the calculations of Bohr being, as he showed, applicable only to α-particles. The purpose of the work described in this paper is to develop a theory of the straggling of β-particles by thin foils and by means of it to interpret the results of experiment. The paper is arranged as follows. In 2 an account is given of the state of the experimental work on the subject, and in particular the effect of the complications introduced by "scattering" are considered. The formula derived by Bohr for the straggling of electric particles is given in 3 and its inapplicability to β-particles demonstrated. The present calculations of the straggling of β-particles are given in 4. The theory of the straggling of electric particles resolves itself into two parts. The first deals with the dynamics of collisions between electric particles and atoms, and is the same whether we are concerned with the straggling or some other phenomena such as ionisation of "stopping power." This may be called the fundamental theory and its requirements may be summarised in the function ϕ (Q) which express the frequency of collisions in which the electric particle loses energy of amount Q. The second part of the theory is the process of calculating the straggling by means of probability theory from the function ϕ . This may be regarded as the straggling theory proper and it is the main subject of 4. When the present calculations were started it was intended to calculate the straggling on the basis of classical theory only, the value of the function ϕ on this theory being definitely known. However, after some practice with the type of calculation involved it was decided to calculate the straggling for other forms of ϕ . From the results obtained it is possible to deduce the straggling corresponding to any form which ϕ may reasonably have, and if a new theory leads to a value of ϕ different from the classical value, the straggling on the new theory may readily be determined. Alternatively this fuller treatment may be used for the reverse process of calculating from the observed straggling the value of ϕ to which it corresponds. This is considered to be the most convenient procedure and in 5 the form of ϕ which explains the experimental results is deduced. this is compared in 6 with the value of ϕ on classical theory. A brief outline is given in 7 of certain new ideas concerning the nature of collisions of electric particles with electrons and atoms.


1962 ◽  
Vol 35 (4) ◽  
pp. 918-926 ◽  
Author(s):  
P. Mason

Abstract In Part I of this series it was shown how variations in the dynamic Young's modulus with extension could be represented by linear relations for gum rubbers in the region of 0 to 100% extension. The present work uses a similar treatment to examine how the viscoelastic behavior of natural rubber within this extension region is affected by the incorporation of two carbon blacks of widely differing colloidal activity. One of these materials, MT black, consists substantially of spherical particles with a mean diameter of about 0.4 microns: electron microscopy of cut surfaces of the black-rubber compound showed that the individual particles were well-dispersed. The finer material, HAF black, has a mean particle diameter of about 0.04 microns but exists in the rubber compound in a flocculated condition with aggregates up to about 0.3 microns in diameter. The rubber containing the coarse, MT black yielded linear strain relations enabling a direct comparison to be made with the behavior of the gum: the HAF material did not give linear relations for either the dynamic or the equilibrium Young's modulus. To facilitate discussion of this behavior it is desirable to set out more explicitly than in Part I the model underlying the analysis.


Author(s):  
Yijie Wang ◽  
Jun Chen

Abstract Digital in-line holography (DIH) has been applied to measure the 3D position of objects in a variety of applications, including bubbles and droplets in multi-phase flows, tracking particles in turbulence flows, etc. In addition to the 3D position, the morphology and dimension of the individual particles can also be extracted from the recorded hologram. In this study, a lens-less digital in-line holography setup is applied to measure the morphology and size of three kinds of solid particles (Wollastonite Powder, Pearl Mica Powder and Solder Powder), whose sizes range from several to hundreds of micrometers. The statistics of equivalent diameter, aspect ratio and circularity are introduced to describe the morphology and dimension of each kind of particles. Microscopic images of the particles are taken to verify the accuracy of measurements with DIH. The results measured from DIH are in good agreements with results from microscopic images.


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