MAGNETIC SUSCEPTIBILITY OF BEDDED IRON‐FORMATION

Geophysics ◽  
1963 ◽  
Vol 28 (5) ◽  
pp. 756-766 ◽  
Author(s):  
Charles E. Jahren
Keyword(s):  
Magnetic Material ◽  
Magnetic Susceptibility ◽  
Diameter Ratio ◽  
Iron Formation ◽  
Volume Percent ◽  
Homogeneous Sample ◽  
Magnetite Content ◽  
The Relationship ◽  
Apparent Susceptibility ◽  
Layered Samples

The susceptiblity of natural and artificial iron‐formation samples in the form of cylinders with length‐to‐diameter ratio less than 1.2 and susceptibility up to one cgs unit was measured in fields of the order of one gauss. Demagnetization factors calculated for the centers of the cylinders explain observed changes of apparent susceptibility with length and direction of magnetization. Layered samples made by stacking disks of magnetic and nonmagnetic material alternately show susceptibility as much as three times greater parallel to the layers than across them, with layer susceptibility as high as 0.5 cgs. This anisotropy increases with increasing layer susceptibility and is largely independent of the details of layering when less than half the volume of the sample is magnetic material. Natural layered samples show the same range of susceptibility anisotropy. The relationship between susceptibility, k, and volume percent magnetite, V, can be approximated by [Formula: see text] cgs, 10<V<40, corresponding to susceptibility 0.7 for pure magnetite. The along‐the‐layer susceptibility of a bedded sample containing 20 volume percent total magnetite is twice that of a homogeneous sample of the same overall magnetite content. For one percent total magnetite, it is three times as great.

MAGNETIC SUSCEPTIBILITY MEASUREMENTS IN MINNESOTA PART II: ANALYSIS OF FIELD RESULTS

Geophysics ◽  
1953 ◽  
Vol 18 (2) ◽  
pp. 383-393 ◽  
Author(s):  
Harold M. Mooney ◽  
Rodney Bleifuss
Keyword(s):  
Magnetic Susceptibility ◽  
Chemical Analysis ◽  
Magnetic Separation ◽  
The Other ◽  
Volume Percent ◽  
Rock Types ◽  
Magnetite Content

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.

MAGNETIC ANOMALIES AND MAGNETIZATIONS OF THE BIWABIK IRON‐FORMATION, MESABI AREA, MINNESOTA

Geophysics ◽  
1962 ◽  
Vol 27 (5) ◽  
pp. 627-650 ◽  
Author(s):  
Gordon D. Bath
Keyword(s):  
Magnetic Field ◽  
Magnetic Anomalies ◽  
Iron Formation ◽  
Earth’S Magnetic Field ◽  
Aeromagnetic Anomalies ◽  
Magnetite Content ◽  
Earth's Magnetic Field ◽  
Relationship Of ◽  
The Relationship ◽  
Iron Formations

In a study of the relationship of magnetic anomalies to the magnetite content and structure of layered Precambrian iron‐formations, the effective induced and remanent magnetizations of the Biwabik iron‐formation were determined by analyses of aeromagnetic anomalies recorded 1,000 ft above the Biwabik in areas of known geology. The induced magnetization along the layers is relatively insignificant because the formation is almost perpendicular to the earth’s magnetic field. For the relatively unmetamorphosed iron‐formation of the Main Mesabi district, the dominant magnetization was found to be across the layers, about 0.012 gauss, and most likely induced. For the strongly metamorphosed iron‐formation of the East Mesabi district, the dominant magnetization was found to be along the layers, about 0.100 gauss, and remanent. These values are used as bases for explaining aeromagnetic anomalies from correlatives of the Biwabik iron‐formation in the Gunflint, Cuyuna, and Gogebic districts.

Variations in magnetic properties of Mexican serpentinites and related micro-textures 

2021 ◽  
Author(s):  
Sandra B. Ramírez-García ◽  
Luis M. Alva-Valdivia
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Anisotropy Of Magnetic Susceptibility ◽  
Ultramafic Rocks ◽  
Magnetic Carrier ◽  
Temperature Dependent ◽  
Geochemical Studies ◽  
The Relationship ◽  
Magnetite Formation

&lt;p&gt;Magnetite formation of serpentinized ultramafic rocks leads to variations in the magnetic properties of serpentinites; however, magnetite precipitation is still on debate.&lt;/p&gt;&lt;p&gt;In this work, we analyzed 60 cores of ultramafic rocks with a variety of serpentinization degrees. These rocks belong to the ultramafic-mafic San Juan de Otates complex in Guanajuato, Mexico. Geochemical studies have been previously conducted, enabling us to compare changes in the magnetic properties against the chemical variations generated by the serpentinization process. By studying the density and magnetic properties such as anisotropy of magnetic susceptibility, hysteresis curves as well as magnetic and temperature-dependent susceptibility and, we were able to identify the relationship between magnetic content and serpentinization degree, the predominant magnetic carrier, and to what extent the magnetite grain size depends on the serpentinization. &amp;#160;Variations in these parameters allowed us to better constrain the temperature at which serpentinization occurred, the generation of other Fe-rich phases such as Fe-brucite and/or Fe-rich serpentine as well as distinctive rock textures formed at different serpentinization degrees.&lt;/p&gt;

Psychological hardiness as a mediator variable between workplace bullying and job anxiety among early childhood teachers: implications for healthcare

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ghada Farghal Gaber Ahmed
Keyword(s):  
Early Childhood ◽  
Workplace Bullying ◽  
Early Childhood Teachers ◽  
Research Result ◽  
Working Environment ◽  
Homogeneous Sample ◽  
Content Type ◽  
Psychological Hardiness ◽  
The Relationship ◽  
Mediator Variable

Purpose Early childhood teachers play a significant role in building children’s success in their first years of school. Therefore, a healthy early childhood workforce in a healthy working environment is an essential aspect of effective early childhood services. This paper aims to explore the extent to which psychological hardiness can be considered as a mediator variable between exposure to workplace bullying and job anxiety among early childhood teachers. Design/methodology/approach A homogeneous sample comprised of 200 early childhood teachers. For data collection, the researcher used the workplace bullying scale, the psychological hardiness scale and the job anxiety scale among early childhood teachers (prepared by the researcher). Findings The findings indicated that psychological hardiness mediates the relationship between exposure to workplace bullying and job anxiety among early childhood teachers. Originality/value The research result highlighted the necessity of providing counseling programs for early childhood teachers helping them eliminate work stress that affects their job performance. In addition, the kindergarten administration must concentrate on how to effectively communicate and cooperate with early childhood teachers in light of regulations, policies and laws to defeat the spread of workplace bullying. The results of this research contributed to the existing literature by examining the relationship between the research variables, particularly in the early childhood education context.

scholarly journals X-ray Single-Crystal Structural Analysis of a Magnetically Oriented Monoclinic Microcrystal Suspension of α-Glycine

Crystals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 561 ◽  
Author(s):  
Tatsuya Tanaka ◽  
Chiaki Tsuboi ◽  
Kazuaki Aburaya ◽  
Fumiko Kimura ◽  
Masataka Maeyama ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Magnetic Susceptibility ◽  
Single Crystal ◽  
Magnetic Energy ◽  
Powder Sample ◽  
Single Crystal Structure ◽  
X Ray ◽  
Crystal Structural ◽  
The Relationship ◽  
Good Agreement

We previously reported on a method for X-ray single-crystal structure determination from a powder sample via a magnetically oriented microcrystal suspension (MOMS). The method was successfully applied to orthorhombic microcrystals (L-alanine, P212121). In this study, we apply this method to monoclinic microcrystals. Unlike most of the orthorhombic MOMSs, monoclinic MOMSs exhibit two or four orientations with the same magnetic energy (we refer to this as twin orientations), making data processing difficult. In this paper, we perform a MOMS experiment for a powder sample of monoclinic microcrystal (α-glycine, P21/n) to show that our method can also be applied to monoclinic crystals. The single-crystal structure determined in this work is in good agreement with the reported one performed on a real single crystal. Furthermore, the relationship between the crystallographic and magnetic susceptibility axes is determined.

Synthesis and Characterization of T12Ba2CaCu2O8 and T12Ba2Ca2Cu3O10

1989 ◽  
Vol 169 ◽  
Author(s):  
Lauren E. H. McMills ◽  
Shu Li ◽  
Zhen Zhang ◽  
Martha Greenblatt
Keyword(s):  
Magnetic Susceptibility ◽  
Powder Diffraction ◽  
Single Phase ◽  
Synthesis And Characterization ◽  
Synthetic Method ◽  
Superconducting Properties ◽  
X Ray ◽  
Preparation Conditions ◽  
The Relationship

AbstractSingle-phase samples of T12Ba2CaCu2O8 and T12Ba2Ca2Cu3O10 have been prepared using a reliable and simple synthetic method. Samples were characterized by x-ray powder diffraction, magnetic susceptibility and four probe resistivity methods. The TcR=0 values for T12Ba2CaCu2O8 ranged from 100 to 105K, whereas those for T12Ba2Ca2Cu3O10 ranged from 96 to 107K. The relationship between the superconducting properties and the various preparation conditions are discussed.

scholarly journals A relationship between attractiveness and performance in professional cyclists

2014 ◽  
Vol 10 (2) ◽  
pp. 20130966 ◽  
Author(s):  
Erik Postma
Keyword(s):  
Endurance Performance ◽  
Facial Attractiveness ◽  
Hormonal Contraceptive ◽  
Endurance Capacity ◽  
Male Population ◽  
High Quality ◽  
Homogeneous Sample ◽  
Tour De France ◽  
And Performance ◽  
The Relationship

Females often prefer to mate with high quality males, and one aspect of quality is physical performance. Although a preference for physically fitter males is therefore predicted, the relationship between attractiveness and performance has rarely been quantified. Here, I test for such a relationship in humans and ask whether variation in (endurance) performance is associated with variation in facial attractiveness within elite professional cyclists that finished the 2012 Tour de France. I show that riders that performed better were more attractive, and that this preference was strongest in women not using a hormonal contraceptive. Thereby, I show that, within this preselected but relatively homogeneous sample of the male population, facial attractiveness signals endurance performance. Provided that there is a relationship between performance-mediated attractiveness and reproductive success, this suggests that human endurance capacity has been subject to sexual selection in our evolutionary past.

Applications and advantages of the Slingram electromagnetic method for archaeological prospecting

Geophysics ◽  
1986 ◽  
Vol 51 (3) ◽  
pp. 576-584 ◽  
Author(s):  
Alain Tabbagh
Keyword(s):  
Electrical Resistivity ◽  
Magnetic Susceptibility ◽  
Apparent Resistivity ◽  
Electromagnetic Method ◽  
Grid Technique ◽  
Types Of Information ◽  
Mesh Grid ◽  
Apparent Susceptibility ◽  
Depth Of Investigation ◽  
Measurement Capabilities

The electromagnetic Slingram method can provide three types of information simultaneously: (1) the apparent resistivity of the ground; (2) its apparent susceptibility; and (3) the characteristic signatures of buried metallic objects. To build an apparatus with these three measurement capabilities requires an appropriate choice of parameters, including frequency, coil separation, and coil orientation as well as calculations which take into account the electrical resistivity and the magnetic susceptibility of the ground. The value of the Slingram method for archaeological applications is shown by two examples: (1) a Gallo‐Roman pottery workshop investigated with measurements of the apparent susceptibility using a reduced sampling wide mesh grid technique; and (2) the study of a Bronze hoard site located in a marsh. Capabilities of the Slingram method may be improved by further study of an apparatus using several receivers which would increase the depth of investigation. Use of several frequencies would overcome difficulties related to resolving the magnetic quadrature susceptibility.

SOME OBSERVATIONS ON ROCK MAGNETISM

Geophysics ◽  
1958 ◽  
Vol 23 (2) ◽  
pp. 285-298 ◽  
Author(s):  
Lynn G. Howell ◽  
Joseph D. Martinez ◽  
E. H. Statham
Keyword(s):  
Magnetic Field ◽  
Magnetic Material ◽  
Magnetic Susceptibility ◽  
Transition Temperature ◽  
Iron Ore ◽  
Rock Magnetism ◽  
Bedding Plane ◽  
Metamorphic Rocks ◽  
The Magnetic Field ◽  
Red Bed

It seems that in general the plane of maximum magnetic susceptibility lies in the bedding plane for sediments and in the plane of foliation for metamorphic rocks; there is, also, a tendency for the remanent vector to lie in the plane of foliation in the latter. In the case of chemical deposits, the question is raised as to whether the hematite crystal growth is controlled by the magnetic field. Since pure hematite crystals are paramagnetic along the ternary axis, the remanent vector lies in the basal plane perpendicular to this axis, which being the plane of ferromagnetism, is also the plane of maximum susceptibility. We have investigated chemically deposited hematite in the Clinton iron ore of Silurian Age. Although the remanent vector lies close to the plane of maximum susceptibility, this plane, unfortunately, is also the bedding plane. Several other hematite‐bearing formations show a direction of magnetization close to the bedding plane. Measurements of magnetization and susceptibility anisotropy of samples cooled below the transition temperature for hematite have been made with no conclusive results other than indications of the presence of hematite in some cases. Samples from the Hazel formation of pre‐Cambrian Age have been investigated. The planes of maximum susceptibility for this slightly metamorphosed red bed dip at various angles, and thus a system of microfractures containing magnetic material is suggested as a possible explanation. Pole locations for the Clinton iron ore and the Hazel are presented.

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