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Разработан прибор для использования в лабораторной практике различных отраслей промышленности с целью контроля содержания магнитоактивных частиц в текучей среде. В устройство прибора входит исполнительный магнитный сепаратор, обеспечивающий не менее трех пошагово осуществляемых операций сепарации пробы среды посредством проникающих в поток этой среды последовательно расположенных источников равноценного магнитного воздействия, каждый из которых состоит из неферромагнитного гнезда и периодически помещаемого в это гнездо магнитного блока. Под каждым из гнезд, где осуществляется самопроизвольный сброс частиц, выделенных из потока среды магнитным осаждением их на внешней поверхности гнезд и перемещаемых к начальному участку гнезда при периодическом выведении из него магнитного блока, расположены весы с тензодатчиками, сигналы от которых поступают в системный блок цифровизации контроля содержания магнитоактивных частиц, обладающий функциями визуализации получаемой зависимости операционных масс выделяемых частиц., An instrument has been developed for use in laboratory practice of various industries for the purpose of monitoring the magnetoactive particles content in a fluid medium. The device comprises an operative magnetic cobbing machiner which provides for at least three step-by-step separate operations of the medium by means of sequentially arranged sources of equal magnetic action penetrating the flow of the medium, each of which consists of a nonmagnetic socket and a magnetic block periodically placed in the pole piece. Under each of the sockets, where spontaneous discharge of particles separates from the medium flux by magnetic coating on the outer surface of the sockets and transports to the initial section of the socket at the periodic removal of a magnetic block, there are scales with tension gauges, signals of which are transferred to the system digitization unit for the control of the magnetoactive particle content, which has the functions of visualizing the resulting dependency of the operational masses of the emitted particles., Международный научно-исследовательский журнал, Выпуск 5 (119) 2022, Pages 97-101

Fiber-reinforced polymers are increasingly being used, especially in lightweight structures. Here, the effective adaptation of mechanical or physical properties to the necessary application or manufacturing requirements plays an important role. In this context, the alignment of reinforcing fibers is often hindered by manufacturing aspects. To achieve graded or locally adjusted alignment of different fiber lengths, common manufacturing technologies such as injection molding or compression molding need to be supported by the external non-mechanical process. Magnetic or electrostatic fields seem to be particularly suitable for this purpose. The present work shows a first simulation study of the alignment of magnetic particles in polymer matrices as a function of different parameters. The parameters studied are the viscosity of the surrounding polymer as a function of the focused processing methods, the fiber length, the thickness and permeability of the magnetic fiber coatings, and the magnetic flux density. The novelty of the presented works is in the development of an advanced simulation model that allows the simulative representation and reveal of the fluid–structure interaction, the influences of these parameters on the inducible magnetic torque and fiber alignment of a single fiber. Accordingly, the greatest influence on fiber alignment is caused by the magnetic flux density and the coating material.

Separation of ilmenite from titanaugite was investigated by magnetic coating. By enlarging magnetic difference between ilmenite and titanaugite, ilmenite was efficiently recovered. Scanning electro...

Die numerische Berechnung entstehender Kraftwirkungen auf Körper aufgrund magnetischer Wechselwirkungen zwischen diesen, ist in Bezug auf die mechanische Deformation dieser Körper ein noch nicht vollständig gelöstes Problem. In dieser Arbeit wird ein Vergleich vorhandener Kraftberechnungsmethoden hinsichtlich der totalen Kraft anhand eines analytisch berechenbaren Beispiels vorgestellt, sowie Unterschiede der lokalen Kraftdichten dieser Methoden in Anwendung auf die magnetische Beschichtung eines magnetischen Rasterkraftmikroskops aufgezeigt. Due to magnetic interactions between magnetic field inducing bodies, force effects occur on the materials. The numerical computation of those occuring forces with respect to a subsequent structural analysis of a deformable material is still a topic of interest in research. In this paper a comparison between several existent force calculation methods regarding the total force is given for an example with two magnetic cubes. Furthermore, differences are shown concerning the local force densities on the magnetic coating of a magnetic force microscope.

Simulations of mechanical or comfort properties of fibers, yarns and textile fabrics have been developed for a long time. In the course of increasing interest in smart textiles, models for conductive fabrics have also been developed. The magnetic properties of fibers or magnetic coatings, however, are almost exclusively being examined experimentally. This article thus describes different possibilities of micromagnetically modeling magnetic fibers or coatings. It gives an overview of calculation times for different dimensions of magnetic materials, indicating the limits due to available computer performance and shows the influence of these dimensions on the simulated magnetic properties for magnetic coatings on fibers and fabrics.

The results of a study into the effect of cantilever structural parameters on the sensitivity of magnetic force microscopy (MFM) have been presented. It has been shown that it is necessary to use cantilevers with an optimal thickness of the magnetic coating and hardness of the beam lying in the range from 0.1 to 1.0 N/m in order to ensure the maximum sensitivity of the method. The use of these cantilevers makes it possible to register locally arranged single-domain iron particles ∼50 nm in size.

In this paper we investigate a hybrid quantum system comprising a mechanical oscillator coupled via magnetic induced electromotive force to an $LC$ resonator. We derive the Lagrangian and Hamiltonian for this system and find that the interaction can be described by a charge-momentum coupling with a strength that has a strong geometric dependence. We focus our study on a mechanical resonator with a thin-film magnetic coating which interacts with a nano-fabricated planar coil. We determine that the coupling rate between these two systems can enter the strong, ultra-strong, and even deep-strong coupling regimes with experimentally feasible parameters. This magnetomechanical configuration allows for a range of applications including electro-mechanical state transfer and weak-force sensing., 16 pages, 5 figures

We study the Imbert–Fedorov (IF) shifts of a reflected Gaussian beam from anisotropic topological insulators (TIs). Aiming, respectively, at the two types of TI surface perturbations that can alter the surface optical properties, i.e., a magnetic coating and an applied magnetic field, we discuss the dependences of the IF shifts on the axion field, the TI's extent of anisotropy, the angle of incidence and the applied magnetic field. For a left-elliptically polarized incident beam, a positive (negative) axion field can lead to the decrease (increase) of the IF shifts relative to a conventional insulator in the magnetic coating case, and in the applied magnetic field case, the crossover of the IF shifts between the positive and the negative values can be realized by adjusting some external parameters. Also, the properties of the IF shifts are discussed for linearly and circularly-polarized incident beams. The results show that TI might be a desirable candidate for controlling flexibly the IF shifts.

The topics chosen Fe3O4 and r-Fe2O3 nano-magnetic particle, respectively, with polyurethane and polyacrylate mixed ,mixed evenly coated on the surface of the fabric, then on before and after coating fabric tensile properties, tear resistance mechanical properties tested and compared. Experimental results show that: the choice of Fe3O4 better than r-Fe2O3 remanence effects, selection polyacrylate better softness than the selection of polyurethane, the latitude and longitude to the breaking strength was increased in the magnetic coating of the fabric, while the tear strength and abrasion resistance were reduced .

We investigate the importance of using nanotips on a point contact spin-transfer torque (STT) experiment. A systematic analysis comparing the STT in a magnetic thin film in current-perpendicular-to-plane (CPP) geometry sample for magnetic coated and uncoated tungsten nanotips is shown. The STT effect presents a reverse resistance to current behavior when using a magnetic coating layer on the nanotips. We demonstrate that the magnetic layer on the tip may assume the role of a polarizer layer. This effect opens up the possibility of exploiting simpler architectures in STT-based devices, such as STT-random access memory (STT-RAM).

The general case where the depth of the informative zone is greater than the thickness of a nonmagnetic base having a two-sided weakly magnetic coating is considered. In this case, the informative signal is determined by the thickness of the base and coating on both sides. A technique for separately measuring the coating thickness on either side taking into account the effect of both coatings on the informative signal is proposed as applied to the magnetodynamic method.

Magnetic tape industry uses a mixture of fatty acids/fatty acid esters. This lubricant mixture transfers from the tape surface to the recording GMR head whereby they cause fouling the tape and enhances corrosion to the GMR head. The current study aims at finding a substitute lubricant that could make a bond with the binder and has no corrosive effect.

In order to improve the spatial resolution achieved by magnetic force microscopy (MFM) technique and its derivatives, we employ here advanced MFM tips fabricated by means of focused ion beam (FIB) milling. The magnetic coating applied on these tips is a CoCr film of 10 nm thickness. The MFM measurements on hard disk test samples reveal the achieved high resolution, and the measurement on a garnet film demonstrates the low invasiveness. High-frequency MFM (HF-MFM) is a development of the MFM technique to observe the HF stray fields emerging from magnetic recording writer poles at their operating conditions. By means of HF-MFM, magnetic recording writer poles are characterized in the frequency range 100–1,000 MHz. Up to now, all HF-MFM experiments conducted were using standard MFM cantilevers. From the HF-MFM images obtained using the advanced MFM cantilevers, it is clearly seen that the spatial resolution is considerably improved over the images obtained using standard MFM tips. However, the 10 nm thick magnetic coating of the cantilevers is found to work properly only at frequencies of up to about 500 MHz. SCANNING 30: 27–34, 2008. © 2008 Wiley Periodicals, Inc.

A high-frequency magnetic force microscope (HF-MFM) is built up for the observation of the high-frequency stray fields of harddisk write heads. We demonstrate the performance of the system using harddisk write heads from different manufacturers. We show that the use of advanced high-aspect ratio MFM cantilevers yields HF-MFM images with clearly improved spatial resolution. Furthermore, we present results obtained using MFM cantilevers with a magnetic coating of Ba3Co2Fe24O41 (BCFO).

The magnetic characterization of four experimental advanced double-coated MP tapes with different magnetic coating thickness has been completed. Although standard vibrating sample magnetometer (VSM) measurements show very similar characteristics such as coercivity, squareness and orientation ratio (OR), alternative measurements show distinct differences in addition to their magnetic thickness. The in-plane distribution of easy axes (EAD) measured using a bi-axial VSM, show that the distribution width increased as the magnetic coating thickness decreased. A theoretical relation between OR and EAD was used to determine the out-of-plane distribution width. This was found to be narrower than the in-plane equivalent, as expected. The out-of-plane distribution width decreased as the magnetic thickness decreases, contrary to the in-plane variation.

The structure of magnetic coating films was analyzed by the ultra-small-angle X-ray scattering (USAXS) technique. Small-angle X-ray scattering (SAXS) has been used to investigate the size, shape, and correlation of the nm sized structure. USAXS, with a measurable range extending to the µm order, can be used to analyze the submicron sized structure of paints and coating films. Preliminary USAXS experiments for a magnetic paint and magnetic coating films revealed that USAXS is useful to evaluate the structure of the particles in the paint and the films. Combined with other experimental methods, USAXS will provide a new kind of information about the structural analysis.

The separation of magnesite fines from serpentine fines by magnetic carrier methods has been examined in this study. The zeta-potential of serpentine, magnesite and magnetite was measured with and without dodecylamine as surfactant. The interaction energies between the particles were then calculated. Without the surfactant, no magnetic coating was obtained despite the favourable predictions for narrow pH ranges. When surfactant is added in suspensions of separate minerals, the serpentine particles obtain a magnetic coating strongly attached to the surface in the range 6 9. The experimental results are in excellent agreement with the theoretically predicted results for serpentine and in fairly good agreement for magnesite. When artificial mixtures of serpentine and magnesite were used, the metallurgical results are slightly different from the results on separate minerals.

A pin-on-disk apparatus was used to study the tribological failure of rigid disk drives, which can be described as lightly, lubricated non-metallic (mostly, ceramic-on-ceramic) sliding systems operating at low loads. The wear models proposed to explain the degradation of the disk magnetic coating, which is deposited on a metallic substrate, can be grouped into two categories; gradual abrasive or adhesive wear processes or sudden fatigue-type failures. In this paper experimental results are reported to eliminate the latter possibility, and an analytical model based on the adhesive wearof alumina particles is derived. This model, which was experimentally verified, expresses the disk life as a function of the mechanical and physical properties of disk and head materials, and the geometry of the pin-medium interface.

To experimentally investigate the acoustical behavior of different dual-mode nanosized contrast agents (NPCAs) for echographic medical imaging at low ultrasound (US) frequency.We synthesized three different nanosized structures: (1) Pure silica nanospheres (SiNSs); (2) FePt-iron oxide (FePt-IO)-coated SiNSs; and (3) IO-coated SiNSs, employing three different diameter of SiNS-core (160, 330 and 660 nm). Tissue mimicking phantoms made of agarose gel solution containing 5 mg of different NPCAs in 2 mL-Eppendorf tubes, were insonified by a commercial echographic system at three different low US pulse values (2.5, 3.5 and 4.5 MHz). The raw radiofrequency signal, backscattered from each considered NPCA containing sample, has been processed in order to calculate the US average backscatter intensity and compare the acoustic behavior of the different NPCA types.The highest US contrast was exhibited by pure SiNSs; FePt-IO-coated SiNSs acoustical behavior followed a similar trend of pure SiNSs with a slight difference in terms of brightness values. The acoustic response of the examined NPCAs resulted function of both SiNS diameter and US frequency. Specifically, higher US frequencies determined higher value of the backscatter for a given SiNS diameter. Frequency-dependent enhancement was marked for pure SiNSs and became less remarkable for FePt-IO-coated SiNSs, whereas IO-coated SiNSs resulted almost unaffected by such frequency variations. Pure and FePt-IO-coated SiNSs evidenced an image backscatter increasing with the diameter up to 330 nm. Conversely, among the types of NPCA tested, IO-coated SiNSs showed the lowest acoustical response for each synthesized diameter and employed US frequency, although a diameter-dependent raising trend was evidenced.The US characterization of magnetically covered SiNS shows that FePt-IO, rather than IO, was the best magnetic coating for realizing NPCAs suitable for dual mode imaging of deep organs, combining US and magnetic resonance imaging.

While the properties of conductive fibres and coatings on textiles can easily be measured and calculated, magnetic coatings of fibres, yarns and fabrics still lack descriptions of their physical properties. Since magnetic textiles can be used for a variety of applications, from magnetic filters to invisible water-marks to magnetic coils and sensors, simulations would be supportive to understand and utilize their properties. The article gives an overview of different coatings on textile fibres, varying the magnetic materials as well as the fibre composition, giving rise to the interactions between neighbouring coated fibres. In this way, it is possible to understand the strong shape anisotropy which must be taken into account when the magnetic properties of textiles are to be tailored. Additionally, the differences between several possible magnetic coating materials become visible. This study can help adjusting the magnetic properties of textile fabrics to a desired application.

The magnetic tape industry applies a mixture of stearic acid/butylstearate as a lubricant mixture in their formulation. This lubricant system has several disadvantageous points since it enhances corrosion to the GMR head, due to the existence of the stearic acid free carboxylic group; also, it is not chemically bonded to the tape surface and can freely leave the tape surface in time, leading to inferior winding/unwinding performance of the tape. In this work, we pursue our challenging task for finding a better lubricant(s) to resolve the problems with the current commercial lubricant system. We also continue working with the hypothesized model test sample which imitates the features for the real magnetic tape surface. The goal of this series of work is to correlate between the chemical structures for the miscellaneous lubricants and their micro-tribological behavior at the interface between the sample and reference guide surfaces.

CrO2 particles provide a good basis for proper pulse recording due to their high output at short wavelengths, combined with low noise print-through. Furthermore, one outstanding features is their low electrical resistance. It avoids statics charging of the magnetic coating and thus eliminates both dropouts caused by the attraction of loose particles and tape edge damage cause by a rough tape pack due to tape static.

The particulate magnetic disks commonly used in magnetic disk storage systems contain aluminum-oxide (Al2O3) particles to reinforce the strength of their magnetic coating. In this paper, the influence of these particles on the tribological characteristics of particulate disks is investigated using two types of ferrite materials for flying heads and particulate disks with four different levels of Al2O3 content. As the Al2O3 content increases, the wear mode changes from the adhesive wear to the abrasive wear. Owing to this transition, the head wear becomes increasingly severe while the durability of the particulate disk improves. Regarding the differences between ferrite materials, relatively soft Mn-Zn ferrite shows worse wear results than hard Ni-Zn ferrite. In particular, it is found that Mn-Zn fertile is worn even by the γ-Fe2O3 particles of the particulate disks. In the combination of ferrite materials and particulate disks used here, an Al2O3 content of around 8 percent is optimum to avoid headcrash, ...

The manufacture of wet-coated magnetic recording media requires the dispersion of the magnetic particles in a blend of resin components and solvents. For optimum quality products the magnetic particles have to be ideally dispersed, the resulting dispersion should be stable over a period of at least 24 h, and the dispersing aids should have a neutral or positive effect on the final properties of the coating. It is now reported that AB-block copolymers are advantageous for the dispersion of magnetic pigments. Compared to conventional polymeric dispersants frequently based on vinyl chloride copolymers, a higher rate of dispersion is achieved. The influence of the structure of the dispersant on the dispersing properties is discussed.

This paper describes two optical devices: one device is capable of measuring real-time the surface roughness of the magnetic coating in the production process in the range of 5 to 40 nm (RMS) and the other device is designed for table measurements. Both devices are easy-to-install and easy-to-use.

We investigated the dependence of the performance of magnetic force microscopy (MFM) on magnetic coating materials by using carbon nanotube (CNT) probes. The magnetic structures of CNT-MFM probes with CoFe(80:20), CoFe(30:70), and CoCr(80:20) coatings were essentially the same in the simulations, but their magnetic properties, such as stability after magnetic reversal, varied slightly in the experiments. It was found that a larger saturation magnetic moment (Ms) is of advantage for attaining high spatial resolution. Although the distinction was hard to see in the MFM images, the experiments and simulations showed that CNT probes coated with high Ms materials gave stronger perturbations to soft magnetic materials than probes coated with low Ms materials.

The uppermost pigment particles of a magnetic coating are covered by a thin layer of organic material. Compared to the bulk of the binder formulation, this layer is highly inhomogeneous. At the phase boundaries to air and pigments, concentration gradients are observed which influence the mechanical behavior of the coating, especially when changes take place that are effected by time and climatic conditions. By applying ESCA and SIMS techniques, important information on this surface layer could be obtained concerning: (1) the thickness of this layer, its distribution, and its differences between magnetic and nonmagnetic particles; (2) the incompatibilities and varying distribution of the components of a given formulation; and (3) the mobility of low molecular additives (alteration during changes of climatic conditions or transfer of substances onto contacting bodies). >

After performing comparative coating thickness measurements using magnetic. coulometric and profilographic methods it has been determined that the coating thickness value obtained by the magnetic method is lower than the actual value, measured by the profilographic method. The measurements of hot-dip coatings with a thickness of 15-20 μm using a magnetic coating thickness gauge have shown that the measurement error may reach 32 %. An introduction of a correction factor equal to 1.3 was proposed.

Publisher Summary This chapter discusses video discs. A video disc has two major advantages over a video cassette: the facility to reproduce a still frame, and the very rapid random access time. These features make video discs particularly suitable for the data market, including interactive teaching aids. The Philips Laser Vision system was introduced into the entertainment market in 1978 but has since developed more steadily as an information storage device. The disc has only one information track, which carries the video and two audio channels on a single fm carrier similar to the VHD disc, but the storage is by variations of a reflective coating, protected by a transparent faceplate. The encoded information is scanned by a small lightspot from a laser source, and the reflected signal measured by a photocell. A floppy disc or diskette is used in home computers and word processors and could now be classified as a domestic product. Single sided discs are available, but double sided are more general. Each side has a magnetic coating that contains one cue track and 50 information tracks. Some disc drives can read both sides simultaneously.

This paper discusses the important innovations in disk file manufacturing at IBM over the past twenty-five years. Technology advances in the key components of disk files- the magnetic read/write head, its air bearing support, and the disk substrate and magnetic coating- have permitted almost four orders of magnitude increase in areal recording density since the first disk file, the IBM 350, was shipped in 1957. Manufacturing capability for these basic recording technology components has been the key to realizing the cost/performance promise of each new technology. The evolution of this manufacturing capability is discussed with an emphasis on important innovations in processes, materials, tools, and testing techniques.

Experience with helical-scan videotape recorders has shown that the mechanical forces involved in handling the tape are sometimes sufficient to cause significant reductions in signal level due to stress demagnetization. A tape-loop recorder was used in an investigation of stress demagnetization in videotapes. Results are presented illustrating the magnitude of stress demagnetization and its dependence on the type of tape and the number of applications of stress. The bending stress resulting from the wrap of the tape around guides was studied in considerable detail. It is found that bending stress can greatly exceed other stresses involved in the normal handling of tape. Results are presented to show how bending-stress demagnetization depends on the depth of recording in the magnetic coating and on the radius of the guide. It is found that there is also a strong dependence on wrap angle around the guide. A new analysis is presented to explain the wrap-angle dependence and to permit calculation of bending-stress demagnetization.

Calendering of magnetic tape is applied to achieve a smooth magnetic coating. The purpose of this study is to gain a better understanding of the calendering process. The investigation is focussed on the roughness and elastoplastic deformation of the uncalendered coating, the substrate and the compliant roll material. It is found that these properties do determine the calendering efficiency to a great extent. Model calculations that are performed using the actual elasto-plastic deformation properties of coating and substrate, confirm the experimental results. A small-scale calender is developed with which coatings are calendered by means of a rolling ball. In this way small samples can be used and a large flexibility is obtained. Surface roughness and modulation noise are measured in order to characterize the calendering efficiency. The elasto plastic deformation properties are determined by means of ultra-microindentation measurements. Implementation of the results of this study resulted in an average surface roughness of 4 nm on lab-scale and of 6 nm on semi-production scale.

A combination of structure identifying and bulk property experiments were combined with a two-phase analytical methodology to elucidate the influence of a magnetic tape coating process on the substrate polymer film. Employing a typical tape manufacturing process that utilizes coating, drying, and calendering stages, polyethylenete-rephthalate polymer film samples with and without the magnetic coating were prepared.

Whenever there are changes in surface chemistry of the magnetic tape caused by various tribological or environmental parameters, such as humidity and temperature, they may significanty increase the adhesive interaction between the magnetic tape and the drive components. Exposure to high humidity at elevated temperatures for extended periods can result in the hydrolytic degradation of the tape-binder system. The products of hydrolytic degradation have lower molecular weight and may be tacky in nature. Changes in the binder can be monitored by measuring molecular weight, extractable binder-to-lubricant ratio, and modulus of elasticity. A chemically stable binder system minimizes the risk of high friction. In the case of tapes tested at low humidity, the frictional behavior shows little dependence on the chemistry of the binder and primarily on the thermomechanical response of the magnetic coating. It is also noted that in most commercial tapes, the friction is high when measured at high humidities (above 60...

In this paper the advantages of connecting a tensile tester to a microcomputer are described. The advantage of this combination compared with the combination of tensile tester and conventional available data analyzer is a much better accuracy of the measurements of viscoelastic materials e.g. magnetic tapes. Using this hardware combination the spread on the measurements is reduced substantially. With this increased accuracy it is now possible to determine the Young's modulus of an actual magnetic coating by measuring the tape and subtracting the basefilm contribution. The justification for this procedure is given and followed by measurements of samples of different origins.