scholarly journals MAGNETIC STUDIES OF NATURAL AND MAN-MADE PROCESSES OF CRITICAL INFRASTRUCTURE OBJECTS AT THE AREA "GLINKA"

2020 ◽  
pp. 34-39
Author(s):  
O. Menshov
Keyword(s):  
Magnetic Susceptibility ◽  
Frequency Dependence ◽  
Critical Infrastructure ◽  
Average Intensity ◽  
Magnetic Studies ◽  
Magnetic Parameters ◽  
Erosion Processes ◽  
Specific Magnetic Susceptibility ◽  
Joint Interpretation ◽  
The Vertical Distribution

The results of magnetic soil and underlying rocks studies at the area near Lake Glinka are considered. This study was performed as a part of the landslide investigation of the urban environment of the Kyiv agglomeration. The aim was to detect the natural and man-made processes affecting critical infrastructure. Under field condition we measured the volume magnetic susceptibility of soil κ (10-3 SI), and sampling was performed. Under laboratory conditions we measured and then calculated the mass-specific magnetic susceptibility χ (10-8 m3/kg), and its frequency dependence χFD (%). The soil of the study area is gray forest (Greyic Phaeozems Albic in WRB) with signs of urban soil. Magnetic studies were conducted at two points on the high landslide bank of the Lake Glinka, as well as on the opposite low bank. On the low bank, we organised measurements and sampling along the micro-catena and at the vertical soil section to study the soil genetic horizons. Magnetic polygons were constructed based on cosmography downloaded by ArcGIS. The classification of the polygons is made by the attracting the magnetic susceptibility and its frequency dependence. We identified the polygon with the highest values of magnetic susceptibility (χ = 54 × 10-8 m3/kg) and the lowest value of frequency dependence (χFD = 3.6 %). This is the soil with man-made pollution. Two polygons with similar values of magnetic parameters were identified: χ = 25-35 × 10-8 m3/kg, χFD = 8-10 %. Such values are related to the natural soils. Three polygons (two on the the low bank and one on the high landslide bank of Glinka) have average intensity values of magnetic parameters: χ=35-40 × 10-8 m3/kg, χFD = 6-7 %. The vertical distribution of soil magnetic parameters in genetic horizons was observed and the redistribution of magnetic matherial was detected. Such kind of the redistribution indicates the erosion processes. The magnetic properties of soils are important for the joint interpretation with electric tomography, GPR measurements, and GIS analysis of the national landslide database of Ukraine. The results are useful for the development of the algorithm for the environmental monitoring of the critical infrastructure at the urban area.

Linking cave sediments and soil magnetism in the Urșilor cave (Romania)

2021 ◽  
Author(s):  
Cristian George Panaiotu ◽  
Cristian Necula ◽  
Relu D. Roban ◽  
Alexandru Petculescu ◽  
Ionut-Cornel Mirea ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Frequency Dependence ◽  
Remanent Magnetization ◽  
Rock Magnetism ◽  
Magnetic Mineral ◽  
Magnetic Data ◽  
Sediment Samples ◽  
Superparamagnetic Particles ◽  
Susceptibility Data ◽  
Cave Sediments

<p>Cyclical changes in the magnetic mineral assemblages have been observed in numerous sedimentary records confirming the relationship between rock magnetism and past global change. Several studies have shown that the magnetic susceptibility data of cave sediments reflect both long- and short-term climatic oscillations. These magnetic susceptibility variations are attributed to changes in climate-controlled pedogenesis which influence the production of low coercivity magnetic mineral phases, magnetite, and maghemite outside the cave. These soils with climate-dependent magnetic properties are then washed, blown, or tracked into the cave where they accumulate, creating the changes observed in rock magnetic data. We present a rockmagnetism study of the sediments from the Urșilor cave and the soils above the cave. Our focus is the detailed characterization of the ferromagnetic mineralogy preserved in the cave sediments and its links with potential soil sources. In the cave, we sampled four sections (2-3 m high) consisting mainly of silts and clays, with some sand layers. The age of the sediments is older than 40 ka. At the surface, we sampled various types of soils from 9 sites. For all samples, we measured: variation of magnetic susceptibility with frequency (976 and 15616 Hz), the anisotropy of magnetic susceptibility, isothermal remanent magnetization, and anhysteretic remanent magnetization. Because soils are characterized by the presence of superparamagnetic magnetite produced by pedogenesis which can be detected by the frequency dependence of magnetic susceptibility, we also measured the frequency dependence of soils and selected cave sediment samples at 13 frequencies (between 128 and 512000 Hz). Multi-frequencies measurements of the magnetic susceptibility of recent soils show that all the sampled soils have a strong frequency dependence indicating the presence of superparamagnetic particles produced by pedogenesis. Most of the sediment samples have an important frequency dependence similar to the one observed in the recent soils. As a preliminary conclusion, we can state that most of the fine cave sediments contain superparamagnetic particles, which can be probably attributed to soils transported into the cave by erosion. These results suggest that during the deposition of high magnetic susceptibility sediments it was a climate favorable for intense pedogenesis. The interpretation of the intervals with lower values of magnetic susceptibility is still under investigation to decide if represents a climatic signal or a change in the dynamics of sediment transport. <strong>Acknowledgment:</strong> The research leading to these results has received funding from the EEA Grants 2014-2021, under Project contract no. EEA-RO-NO-2018-0126.</p>

X-ray diffraction and magnetic studies of altered ilmenite and pseudorutile

1980 ◽  
Vol 43 (329) ◽  
pp. 659-663 ◽  
Author(s):  
M. J. Wort ◽  
M. P. Jones
Keyword(s):  
Magnetic Susceptibility ◽  
Western Australia ◽  
Wide Distribution ◽  
Diffraction Spectrum ◽  
X Ray Diffraction ◽  
Magnetic Studies ◽  
Subsequent Work ◽  
Secondary Alteration ◽  
X Ray ◽  
Magnetic Spin

SynopsisIT was not until 1966 that pseudorutile was first defined. Earlier, its X-ray diffraction spectrum had been confused with that of futile and, to a lesser degree, with those of hematite and ilmenite. Subsequent work has shown that pseudorutile has a world-wide distribution in detrital ilmenite-bearing heavy mineral deposits. The present work has confirmed its magnetic susceptibility and density. In addition pseudorutile is shown to be a magnetic spin glass with a peak susceptibility at 23 °K.Altered ilmenites, in which pseudorutile occurs as a secondary alteration product, display a range of chemical composition and magnetic susceptibility. The most highly magnetic fractions are not necessarily those containing the least-altered ilmenite, and in material from Capel, Western Australia, the most highly magnetic fractions were those containing grains of ferrimagnetic ferrian ilmenite.Quantitative X-ray diffraction has shown that West Australian altered ilmenite contains significant amounts of amorphous ilmenite, pseudorutile, and rutile. The magnetic susceptibility of paramagnetic fractions of altered ilmenite from Capel, Western Australia, can be calculated from normative compositions based on chemical analyses.

scholarly journals Iron-containing phases in metallurgical and coke dusts as well as in bog iron ore

Nukleonika ◽  
2017 ◽  
Vol 62 (2) ◽  
pp. 187-195 ◽  
Author(s):  
Tadeusz Szumiata ◽  
Marzena Rachwał ◽  
Tadeusz Magiera ◽  
Katarzyna Brzózka ◽  
Małgorzata Gzik-Szumiata ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Spinel Structure ◽  
Iron Ore ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mineral Phases ◽  
Coke Plants ◽  
Wide Range ◽  
Specific Magnetic Susceptibility ◽  
Diffraction Patterns

Abstract Several samples of dusts from steel and coke plants (collected mostly with electro filters) were subjected to the investigation of content of mineral phases in their particles. Additionally, sample of bog iron ore and metallurgical slurry was studied. Next, the magnetic susceptibility of all the samples was determined, and investigations of iron-containing phases were performed using transmission Mössbauer spectrometry. The values of mass-specific magnetic susceptibility χ varied in a wide range: from 59 to above 7000 × 10−8 m-3·kg−1. The low values are determined for bog iron ore, metallurgical slurry, and coke dusts. The extremely high χ was obtained for metallurgical dusts. The Mössbauer spectra and X-ray diffraction patterns point to the presence of the following phases containing iron: hematite and oxidized magnetite (in coke and metallurgical dusts as well as metallurgical slurry), traces of magnetite fine grains fraction (in metallurgical dusts), amorphous glassy silicates with paramagnetic Fe3+ and Fe2+ ions, traces of pyrrhotite (in coke dusts), α-Fe and nonstoichiometric wüstite (in metallurgical slurry), as well as ferrihydrite nanoparticles (in bog iron ore). For individual samples of metallurgical dusts, the relative contributions of Fe2+/3+ ions in octahedral B sites and Fe2+ ions in tetrahedral A sites in magnetite spinel structure differs considerably.

Long range antiferromagnetic exchange in dinuclear copper(II) complexes containing 1,4-dicyanamidobenzene dianion bridging ligands

1995 ◽  
Vol 73 (4) ◽  
pp. 573-580 ◽  
Author(s):  
Linnus L. Cheruiyot ◽  
Robert J. Crutchley ◽  
Laurence K. Thompson ◽  
J.E. Greedan ◽  
Guo Liu
Keyword(s):  
Magnetic Susceptibility ◽  
Elemental Analysis ◽  
Epr Spectroscopy ◽  
Antiferromagnetic Exchange ◽  
Temperature Dependent ◽  
Magnetic Studies ◽  
Bridging Ligands ◽  
Dimer Model ◽  
Bridging Ligand ◽  
Exchange Constants

Six Cu(II)dimers, [{Cu(dien)}2(μ-dicyd)][CF3SO3]2 (1), [{Cu(dien)}2(μ-Me2dicyd)][CF3SO3]2 (2), [{Cu(dien)}2(μ-Cl2dicyd)][CF3SO3]2 (3), [{Cu(L)}2(μ-dicyd)] (4), [{Cu(L)}2(μ-Me2dicyd)] (5), and [{Cu(L)}2(μ-Cl2dicyd)] (6), where dicyd2−, Me2dicyd2− and Cl2dicyd2− are unsubstituted, 2,5-dimethyl- and 2,5-dichloro-1,4-dicyanamidobenzene dianions, respectively, dien is diethylenetriamine, and L− = 1,3-bis(2-pyridylimino)isoindolinato, have been synthesized and characterized by elemental analysis, IR, UV–vis, and EPR spectroscopy, and magnetic studies. Temperature-dependent magnetic susceptibility measurements of the complexes 1–6 from 5 to 300 K are reported. The data for 2, 3, 5, and 6 have been fitted to a dimer model with a modified Bleaney–Bowers expression which derived antiferromagnetic exchange constants −J = 10.6, 4.5, 5.2, and 3.0 cm−1, respectively (where the Hamiltonian is of the form [Formula: see text]) For 4, an approach to a maximum in χm with decreasing temperature gave an estimated −J < 3.5 cm−1. Only complex 1 showed Curie–Weiss behavior. This is far weaker antiferromagnetic exchange compared to that observed for dinuclear Ru(III) complexes incorporating the dicyd2− bridging ligands (J. Am. Chem Soc. 114, 5130 (1992)) and is attributed to a symmetry and energy mismatch between Cu(II) σ* magnetic orbitals and the πnb molecular orbitals of the bridging ligand which are important for superexchange. Keywords: superexchange, copper dimer, dicyanamidobenzene.

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