Polyphase nature of Grib pipe formation and its manifestation in paleomagnetic rock properties and sieve diamond characteristics

Paleomagnetic pipe rock properties and sieve diamond characteristics are discussed. To determine paleomagnetic characteristics, 59 samples (41 kimberlites and 18 xenotuff breccias) were taken from pipe rocks in 2019- 2020. Based on analysis results and the obtained data comparison, reasons of magnetic anomaly epicenter shift are validated and polyphase nature of Grib pipe formation is proved. The results suggest complex pipe structure with abnormally magnetized kimberlites. They could be the main anomaly, a focus of early prospecting, which resulted in the pipe discovery. Their location, mostly in the central and eastern pipe combined with primarily east-trending residual magnetization, can account for the eastward anomaly shift and partly beyond the pipe contour. Polyphase pipe nature is also confirmed by various sieve characteristics of diamonds from the orebody.

Magnetic Enhancement and Nitriding Process of Fe Atomic Layers on Si (111)-7×7-CH3OH Surface

Fe atoms were steamed on Si(111)-7×7 surface, which had been saturated by CH3OH. Aim to greatly enhance the magnetic performance, nitriding experiments were implemented and adjusted on the existing linear Fe clusters. First of all, the dissociation of CH3OH adsorption process was deducted in detail, which laid a good foundation for the better use of surface quasi-potential. Further to solve the coming problems like weak linearity and low nitriding effect, the formation mechanism of iron-nitride was explored. Atomic layers of Fe deposition are confirmed as the key to NH3 dissociation process (at room temperature). Specifically, the higher Fe atomic layer contacted by NH3, the weaker influence of surface quasi-potential. With the introduction of Ar, Fe deposition could be controlled at 1-2 atomic layers, result in good NH3 dissociation and nitriding efficiency. Combing with magnetic performance result, the density of residual magnetization is improved from 1.5E-0.5 emu to 7.0E-0.5 emu, forming an obvious linear structure. It is also proved that our new linear iron-nitride clusters will maintain good stability with the improvement of nitriding efficiency.PACS: 07.79.Cz; 81.15.-z; 75.75.Fk

Investigation of the Impact of Load on the Magnetic Field Strength of the Crane by the Magnetic Metal Memory Technique

The paper deals with the problem of applicability of the metal magnetic memory (MMM) technique in the crane structural inspection and monitoring. The MMM method does not require the external magnetization of a structure that results in reduction of downtime of maintenance operations. Measurement of the intensity of the self-magnetic leakage signal can be an alternative to other non-destructive methods used for inspection of a large crane’s structure and equipment. However, the complexity of the residual magnetization effect in the MMM technique is the problem with its application. Thus, the magnetic flux leakage behavior on the crane girder surface under different measurements and the crane’s load conditions is analyzed based on the results obtained during experiments carried out on the overhead traveling crane.

Non-Contact Measurement of Residual Magnetization Caused by Plastic Deformation of Steel

Pipelines are the primary means of land transportation of oil and gas globally, and pipeline integrity is, therefore, of high importance. Failures in pipelines may occur due to internal and external stresses that produce stress concentration zones, which may cause failure by stress corrosion cracking. Early detection of stress concentration zones could facilitate the identification of potential failure sites. Conventional non-destructive testing (NDT) methods, such as magnetic flux leakage, have been used to detect defects in pipelines; however, these methods cannot be effectively used to detect zones of stress concentration. In addition, these methods require direct contact, with access to the buried pipe. Metal magnetic memory (MMM) is an emerging technology, which has the potential to characterize the stress state of underground pipelines from above ground. The present paper describes magnetic measurements performed on steel components, such as bars and tubes, which have undergone changing stress conditions. It was observed that plastic deformation resulted in the modification of measured residual magnetization in steels. In addition, an exponential decrease in signal with the distance of the sensor from the sample was observed. Results are attributed to changes in the local magnetic domain structure in the presence of stress but in the absence of an applied field.

Synthesis and properties of magnetic microspheres based on magnetite and hydrophilic polymers

Using emulsification technique, magnetic microspheres (MMS) were prepared from solutions of alginate, pectin, gelatin, chitosan and polyvinyl alcohol. Index of polidispersity of the microspheres was ≤ 0.1. The microspheres from gelatin, chitosan and polyvinyl alcohol covalently crosslinked with glutaraldehyde were resistant to sonication and hydrolysis at room temperature in buffer solution with pH 7.4. The microspheres containing superparamagnetic magnetite particles demonstrated no residual magnetization. After modification, chitosan and polyvinyl alcohol MMS were used for immunomagnetic separation of cells and germs.

INVESTIGATION MAGNETIC FIELD AND ROCK MAGNETISM DIVERSITY OF THE MELNYKOVTCI PLOT OF THE UKRAINIAN SHIELD

The magnetic scanning method was used to study the exposed section of the Ukrainian Shield in its southwestern part (Pobuzhie region). The values of induction T of the magnetic field (49750+– 100 nT, not counting on the global field), and the magnetic susceptibility MS indices “in situ” were determined. It was found that the MS values vary in 0 - 50 • 10-3 u.SI, with the presence of single regions of more than 50 • 10-3 u.SI. Not found regular direct correlations and patterns of changes in the indicators MS and T. An attempt has been made to reveal correlations between fluctuations of the magnetic field and MS-differences. The results are interpreted from the standpoint of local tectonics. Samples taken from exposure, were studied for density, hysteresis of thermomagnetic properties, orientation of the residual magnetization.

MAGNETIC CHARACTERISTICS OF METAMORPHIZED ULTRABASITES OF THE OCEANIC LITHOSPHERE

As part of the study of the nature of magnetic anomalies associated with the deep layers of the oceanic crust, a comparative analysis was made of the petromagnetic characteristics of serpentinized mantle ultrabasic samples taken from oceanographic expeditions of the Institute of Oceanology and the Institute of Geochemistry and Analytical Chemistry of the Russian Academy of Sciences in various morphotectonic regions of the World Ocean. The purpose of the work is to obtain information on the composition, concentration, crystallization temperature and structural features of ferromagnetic minerals, which are formed in different conditions of the post-magmatic metamorphism of ultrabasites. Sample collections are divided into three groups. 1. Oceanic peridotites from the rift zones of the mid-ocean ridges and transform faults. 2. Peridotites of the submarine ridge Gorringe, located within the Azoro-Gibraltar zone of faults. 3. Dunites of the Pekulney complex (Chukotka) formed in the island arc system. It has been established that in all selected regions, samples of serpentinized hyperbasites have high values of natural residual magnetization, magnetic susceptibility and saturation magnetization. The highest values of magnetic parameters are the dunites of the Pekulney complex. Estimation of the dependence of the concentration of ferrimagnetic materials C% of the degree of serpentinization of the SS%. showed that it is practically of little significance. The main factors contributing to the increase in the concentration of magnetite are the increased iron content of olivine in ultrabasites and the temperature of metamorphism. The question of the period of formation of magnetites and the stability of their primary residual magnetization requires further study.