Search

One of the newly developed methods for obtaining super-finished shiny surfaces for non-magnetic freeform jobs is magnetorheological finishing (MRF). MRF is an advanced finishing process in which the grinding force is controlled by magnetic field. The material removal in MRF is governed by the magnetorheological (MR) fluid which mainly consists of carbonyl iron (CI), abrasive particles, carrier fluids and additives. It is a precision-finishing process that can finish complicated geometries or difficult-to-approach regions. MRF process is capable of giving nanometre-scale surface finish. The process makes use of an MR fluid as a tool that acts as a flexible magnetic abrasive brush that provides finishing action. The relative motion between the finishing medium and the work can be obtained either by rotating the work, rotating the finishing medium or both. In the present paper, a set-up has been developed for MRF application using a pillar-drilling machine. Experiments were conducted to finish freeform jobs of copper alloy using the developed process. The effects of various process parameters, viz composition of the MR fluid, rotational speed of work and vessel containing MR fluid, mesh size of abrasives on surface finish, were explored.

In this paper an attempt is made to recover sillimanite by flotation tree analysis process and conventional flotation process from non magnetic fraction of red sediments. The experimental results of both the processes are presented. The data reveal that the deslimed sample contains 33.2% (by weight) total heavy minerals and out of which the sillimanite mineral content is 3.6% (by weight). It is observed that flotation tree analysis needs 10 cells to get five output products and where as conventional flotation process needs 15 cells to recover similar grade of five output products. Thus, flotation tree analysis is not only economic process but also efficient process (to say efficient process, the tree analysis product should be higher grade). Keywords: Tree analysis, Flotation, Red sediment, Sillimanite

a b s t r a c t Negative magnetophoresis of non-magnetic particles is the induced motion of non-magnetic particles suspended in magnetic media on the application of a magnetic field gradient. Negative magnetophoresis can be used to separate nanoparticles based on their size. An integrated finite-element model was developed using COMSOL to study the transport and separation of nonmagnetic particles in a negative magnetophoresis device. The model solves the magnetic field, fluid flow, and mass transfer equations in three dimensions. The model was used to successfully simulate an experimental separation device and was also used as a tool to develop modified designs that resulted in a substantial enhancement of the separation efficiency. In addition, the model successfully predicted the different phenomena that typically occur in a magnetophoretic device: trapping, focusing, and deflection.

International audience; We theoretically investigate a new mechanism of interfacial current in a two-layer system consisting of a magnetic insulator and an adjacent non-magnetic metal. The mechanism is based on Rashba spin-orbit interaction in the metal layer near the interface where the magnetic insulator induces non-zero magnetization. The rotation of the magnetization of the magnetic insulator induces the alternating interfacial current in the non-magnetic metal. Coordinate and time dependencies of the current and induced magnetization in the non-magnetic layer are calculated using quasi-energy approach assuming ballistic conductivity in non-magnetic metal. It is found that the current displays sizable magnitude within the metal layer over a distance which significantly exceeds a region with non-zero spin-orbit interaction. Both the current and the spin density induced in the metal layer demonstrate oscillatory dependence as a function of the distance from the interface due to the interference of the incoming and reflected waves.

We investigate the quasi-static magnetic, magnetotransport, and dynamic magnetic properties in ferromagnetic biphase films with distinct non-magnetic metallic spacer layers. We observe that the nature of the non-magnetic metallic spacer material does not have significant influence on the overall biphase magnetic behavior, and, consequently, on the magnetotransport and dynamic magnetic responses. We focus on the magnetoimpedance effect and verify that the films present asymmetric magnetoimpedance effect. Moreover, we explore the possibility of tuning the linear region of the magnetoimpedance curves around zero magnetic field by varying the probe current frequency in order to achieve higher sensitivity values. The invariance of the magnetic behavior and the asymmetric magnetoimpedance effect in ferromagnetic biphase films with distinct non-magnetic metallic spacers place them as promising candidates for probe element and open possibilities to the development of lower-cost high sensitivity linear magnetic field sensor devices., The research is supported by the Brazilian agencies CNPq (Grants nos. 306423/2014-6, 471302/2013-9, 306362/2014-7, 152650/2016-­4, and 441760/2014-7), CAPES, and FAPERN (Pronem no. 03/2012).

This paper introduces a supercell model to explain the field-induced multiple transitions and the anomalous dilution effect in the nonmagnetic-substituting intermetallic compounds Dy 50− x Al x Ag 50 , in which the shift of the field-induced transitions in the Al-doped samples results from the change of the magnetic structure. At the doping level of x =1.8 (the ratio of Al/Dy approximates 1/26), an anomalous magnetic dilution effect was observed, in which the dilution effect becomes weak and the magnetic behavior is fairly similar to that of pure DyAg. We assumed that the anomalous dilution effect mainly results from the formation of uniform distribution of supercell in the doped Dy 48.2 Al 1.8 Ag 50 .

A rapid and simple method has been developed for the magnetization of non-magnetic materials. The postmagnetization procedure employs magnetic iron oxide microparticles (prepared using a microwave assisted procedure from ferrous sulphate) which are thoroughly mixed with the powder material to be modified. After drying, stable magnetically responsive materials have been formed.

We investigate the spin polarization of a non magnetic material, e.g., a carbon material made from ten C atoms forming a hexagonal structure with total spin S = 0, induced by a ferromagnetic material, e.g., two Fe atoms with a total spin S = 4. Based on the density functional theory, we calculate the total spin density of the system. Our preliminary results show that the total spin for the ten C atoms changes from S = 0 to S = 4, while the total spin of the two Fe atoms changes from S = 4 to S =0. These results seem to indicate that there is a promising possibility to induce spin polarization on a carbon material by Fe atoms.

Non-magnetic metal plates are widely used in aviation and industrial applications. The detection of cracks in thick plate structures, such as multilayered structures of aircraft fuselage, has been challenging in nondestructive evaluation societies. The remote field eddy current (RFEC) technique has shown advantages of deep penetration and high sensitivity to deeply buried anomalies. However, the RFEC technique is mainly used to evaluate ferromagnetic tubes. There are many problems that should be fixed before the expansion and application of this technique for the inspection of non-magnetic conductive plates. In this article, the pulsed remote field eddy current (PRFEC) technique for the detection of defects in non-magnetic conducting plates was investigated. First, the principle of the PRFEC technique was analysed, followed by the analysis of the differences between the detection of defects in ferromagnetic and non-magnetic plain structures. Three different models of the PRFEC probe were simulated using A...

A non-magnetic temperature controlling system used in atomic magnetometer with flowing hot air has been designed and realized. To measure the temperature in the oven without any additional magnetic noise, a fiber Bragg grating was used as a non-magnetic temperature measuring sensor with a high relative accuracy. Analysis has showed the temperature fluctuation can be controlled less than 0.1°C.

It is difficult to sort fine non-magnetic particles only by the buoyancy of magnetic fluid. Therefore, based on the magneto hydrostatic separation, the centrifugal separation under the condition of centrifugal force would be an effective method to improve the efficiency. By establishing the mechanical model of centrifugal separation in magnetic fluid, this paper analyzes the kinematical equations of non-magnetic particles in three directionstangential direction, radial direction, and axial direction, and then theoretically explores the separation mechanism of this method.

Stress development during cofiring a bi-layer laminate with a non-magnetic (Cu0.2Zn0.8O)–(Fe2O3)0.8 (CZF) and a magnetic (Ni0.25Cu0.25Zn0.5O)–(Fe2O3)0.75 (NCZF) ferrite layer has been investigated by measuring camber development and shrinkage rate difference. Development of camber follows a similar trend to that of linear shrinkage rate difference between CZF and NCZF. The sintering mismatch stress generated during cofiring is much less than those of sintering potentials, resulting in no cofiring defects observed at the interface of CZF/NCZF. Results of electrical and magnetic property measurements show that the multilayer NCZF inductor with an embedded CZF layer has a lower electrical resistance at high frequencies and less significant magnetic inductance reduction with increasing DC current than those of a pure multilayer NCZF inductor.

In A- and late B-type stars, strong magnetic fields are always associated with Ap and Bp chemical peculiarities. However, it is not clear at what point in a star's evolution those peculiarities develop. Strong magnetic fields have been observed in pre-main sequence A and B stars (Herbig Ae and Be stars), and these objects have been proposed to be the progenitors of Ap and Bp stars. However, the photospheric chemical abundances of these magnetic Herbig stars have not been studied carefully, and furthermore the chemical abundances of 'normal' non-magnetic Herbig stars remain poorly characterized. To investigate this issue, we have studied the photospheric compositions of 23 Herbig stars, four of which have confirmed magnetic fields. Surprisingly, we found that half the non-magnetic stars in our sample show lambda Bootis chemical peculiarities to varying degrees. For the stars with detected magnetic fields, we find one chemically normal star, one star with lambda Boo peculiarities, one star displaying weak Ap/Bp peculiarities, and one somewhat more evolved star with somewhat stronger Ap/Bp peculiarities. These results suggests that Ap/Bp peculiarities are preceded by magnetic fields, and that these peculiarities develop over the pre-main sequence lives of A and B stars. The incidence of lambda Boo stars we find is much higher than that seen on the main sequence. We argue that a selective accretion model for the formation of lambda Boo peculiarities is a natural explanation for this remarkably large incidence., Comment: To appear in the proceedings of IAUS 302: Magnetic fields throughout stellar evolution. 4 pages, 1 figure. Added references

In this work, we present a study of the magneto transport properties in magnetic multilayered structure $$\text{ Ni }_{81}\text{ Fe }_{19}\text{/Zr }$$ . The magnetic $$(\text{ Ni }_{81}\text{ Fe }_{19})$$ and non magnetic (Zr) layer thickness $$(\mathbf{t}_\mathbf{NiFe}, \mathbf{t}_\mathbf{zr})$$ effects on the magneto resistance (MR) are discussed theoretically in the framework of the Johnson–Camley semi classical approach based on the Boltzmann transport equation. A comparison between calculated and measured MR is obtained. The observed MR ratio oscillates for Zr layer thickness with an average period of 7A. A generally weak $$\text{ MR }(\text{ t }_{\mathrm{NiFe}})$$ ratio for fixed $$\mathbf{t}_\mathbf{zr}$$ is obtained and it shows a maxima peak of the MR with a value of 1.8 % located at $$\mathbf{t}_\mathbf{NiFe}= 80$$ A.

We report on thermal conductivity and specific heat measurements for eight UCu4+x Al8−x compounds (0 ≤ x ≤ 2.0) as a function of temperature and magnetic field. For this series of compounds, previous magnetic and transport studies indicated a transition from magnetic to a non-magnetic heavy fermion state near x cr ≈ 1.15. This paper presents supplementary specific heat and thermal conductivity studies. The ratio of the specific heat over temperature C/T data on the non magnetic compound with x cr ≈ 1.15 show logarithmic dependence with T, a hallmark of non-Fermi liquid (NFL) behavior due to the proximity of a quantum critical point. Compounds with higher Cu content (x > x cr ) exhibit unusual temperature scaling in the specific heat possibly due to an increase in disorder between Cu and Al. Thermal conductivity data show stark contrast in the behaviors between the magnetic (x = 0.5) and non-magnetic compound (x = 1.75). Our results confirm that a simple free-electron picture is inadequate for the description of the low-temperature thermal conductivity properties in non-magnetic UCu4+x Al8−x compounds.

A novel magnetic carrier with surface magnetic field of 4 mT was developed for studying the magnetic enhanced bio-effect on nitrification. The bio-effect on nitrificaton induced by the magnetic carrier was studied by comparing the performance of sequencing batch biofilm reactors filled with magnetic (MC) and non-magnetic (NMC) carriers. The result showed that the bioreactor with MC had better performance for nitrification than bioreactor with NMC. During the biofilm culturing period, the time required for nitrification formation in biofilm of the MC reactor was 25% less than that for the NMC reactor. The results also showed that the ammonium oxidation rate of the MC reactor was 1.6-fold faster than that in the NMC reactor at high influent NH4-N concentration, while nitrite oxidation rate was always accelerated regardless of influent NH4-N concentration. The specific oxygen uptake rate analysis revealed that ammonia and nitrite oxidation activities in biofilm of the MC reactor were 1.65 and 1.98 times greater than those of the NMC reactor, respectively.

Spin-Orbit Torque Magnetic Random Access Memory (SOT-MRAM) with perpendicular magnetic anisotropy (PMA) materials have received greater interest because of their advantages such as low magnetization switching current and fast switching time. Recent studies reported spin-orbit torque in NM/FM/MgO structure with PMA using various non-magnetic materials (Ta, W, Pt, etc.) and ferromagnetic materials (CoFeB, Co, etc.) [1]–[3].

International audience; —This paper analyses the interaction forces between two magnetic boluses for future drug targeting applications. To transport the drugs, it is necessary to convey several therapeutic magnetic boluses using magnetic gradients. The main difficulty is to control a group of different therapeutic boluses at desired states, despite the presence of interaction forces between boluses. To overcome this issue and designing robust control strategies, it is important to fully understand these interactions forces. Based on a dipole-dipole interaction model and dynamic modeling of two magnetic boluses, the magnetic and non magnetic forces are expressed. Finally, an experimental investigation is carried out in a tank under the presence of the magnetic field in order to to assess the prevalence between the magnetic and the non-magnetic interaction forces.

The present paper reports the use of diluted ferrofluid and two arrays of permanent magnets for the size-selective concentration of non-magnetic particles. The micro magnetofluidic device consists of a straight channels sandwiched between two arrays of permanent magnets. The permanent magnets create multiple capture zones with minimum magnetic field strength along the channel. The complex interaction between magnetic forces and hydrodynamic force allows the device to operate in different regimes suitable for concentration of non-magnetic particles with small difference in size. Our experimental results show that non-magnetic particles with diameters of 3.1 μm and 4.8 μm can be discriminated and separated with this method. The results from this study could be used as a guide for the design of size-sensitive separation devices for particle and cell based on negative magnetophoresis.

A new technique, exploiting magnetic nanoparticles as contrast agent, has been recently proposed for microwave breast cancer imaging. As human tissues are non magnetic, the adoption of a magnetic contrast agent, able to selectively target tumoral cells, represents an effective means to increase diagnostic reliability. Although the effectiveness of the new technique has been fully assessed through realistic and accurate numerical simulations, an experimental proof-of-concept is still needed to set the ground for a subsequent pre-clinical stage. In this communication, we present the first results of such an experimental validation, performed with an ad hoc designed laboratory set-up and exploiting a realistic (although simplified) breast phantom.

Intelligent process control technology in various manufacturing industries is important. Vision based non-magnetic object detection on moving conveyor in the steel industry will play a vital role for intelligent process and raw material handling. This paper presents an approach for a vision based system which performs the detection of non-magnetic objects on raw material moving conveyor in a secondary steel making industry. At single camera level, a vision based differential algorithm is applied to recognize an object. Image pixels based differential techniques; optical flow and motion based segmentations are used for traffic parameters extraction, the proposed approach extends those futures into industrial applications. The authors can implement smart control system, since they can save the energy and control unnecessary breakdowns in a robust manner. The technique developed for non-magnetic object detection is having single static background. Establishing background and background subtraction from continuous video input frames forms the basis. Detection of non-magnetic materials which are moving with raw materials and taking immediate action at the same stage as material handling system will avoid the breakdowns or power wastage. The authors achieve accuracy up to 95% with the computational time of not more than 1.5 seconds for complete system execution.

Alluvial deposits within the Sabaloka Gorge and the Sixth Cataract, the Nile River, Sudan, represent a set of deposits with a high lithological variability. This is due to the geomorphology and short-time and intensive flood events resulting in aggradation and erosion of the alluvial zone. Human maintenance of the alluvial zone also plays a role. Therefore, these sediments seem to be ideal for a methodological case study to show how the lithological facies differ depending on the sedimentary dynamics of the river. Non-magnetic proxies together with TOC values depend on magnetic properties characterized by magnetic susceptibility and its frequency dependence.

Electrodeposition of some alloys and multilayer which exhibits the giant magneto resistance (GMR) effect, have been the subject of numerous studies. They have great potential for technological applications, such as magneto resistive sensors and magnetic recording devices. GMR effect is more usually seen in multilayer and alloys structure, when two magnetic layers are closely separated by a thin non-magnetic spacer layer. This paper deals with the review of literature available on electrodeposition of alloys and multilayer for GMR application. The effect of thickness of magnetic, non-magnetic layers, number of bi-layers, electrolyte pH, electrolyte temperature, additives and annealing process on GMR properties will be discussed.

In this paper, we show that the leakage current properties of BiFeO3 (BFO) thin films have been greatly improved by Zr-doping. In contrast, the magnetic properties of Zr-doped BFO films are affected as a weak ferromagnetism. Beyond the double-exchange interactions arising from the creation of Fe2+, we propose another simple model considering the replacement of the magnetically active Fe3+, time to time, by a non-active Zr4+, which is expected to induce a local ferromagnetic coupling rather than an antiferromagnetic one.

We have performed numerical calculations for low-lying excitations induced by a single non-magnetic impurity in a d-wave superconductor on the basis of two different frameworks. One is the Bogoliubov–de Gennes theory in real coordinates, while the other is the Born approximation in wave-number coordinates. This paper shows that these results for low-lying excitations are identical by using Fourier transformations.

The effect of magnetic field on the growth behavior of compound layer was examined at the interface between the solid Cu and liquid AI during reactive diffusion. It was found that the thickness of compound layer was reduced by the high magnetic field. The growth activation energy in β, γ 1 and ɛ 2 layers under a high magnetic field was larger than those in non magnetic circumstances, the increment percentage being 4.8%, 13.3% and 5.5%, respectively.

It is important to separate the nonmagnetic metals from shredded automobiles scraps efficiently. The research relates in general to the separation of non-magnetic metals automatically on the basis of the different density of the magnetic fluids in a magnetic field. A water-based magnetic fluid was prepared with a chemical coprecipitation method by using ultrasonic in dispersing process. The magnetic field system was design and simulated by a finite element analysis software package, ANSYS 8.1. Separation tests were performed on the mixtures of aluminum, zinc, copper and lead with various scrap size and shape using the water-based magnetic fluids.

To study defect origin of ferromagnetism, hollow spheres are better candidates as they are less agglomerated and has both sides of the wall free, as compared to nanoparticles and thin films respectively. Our results show improved magnetic properties of GaN, ZnAl2O4 and MgO hollow spheres over their earlier reported nanoparticle counterparts. Photoluminescence spectroscopy supports our magnetic findings.

The magnetic properties of GaMnAs could be useful in the development of spintronic devices. Yet the precise origin of these properties has been hotly debated. Resonant-tunnelling spectra obtained from GaMnAs devices of superlative quality could finally resolve this issue.

Kondo temperature TK’s for Kondo insulator alloys Yb1-xRxB12 (R = Y, Lu, Sc and Zr) show drastic variation as every x increase. It is found that YbB12 in a virtual gap-less state would have a peak at about 25 K in magnetic susceptibility χ(T) from analysis of χ(T) of all these alloys. Up-turns shown in χ(T) below 20 K grow as development of an energy gap ΔE. Those behaviors may be related to the second-gap development within the in-gap state showing metallic behaviors.Kondo temperature TK’s for Kondo insulator alloys Yb1-xRxB12 (R = Y, Lu, Sc and Zr) show drastic variation as every x increase. It is found that YbB12 in a virtual gap-less state would have a peak at about 25 K in magnetic susceptibility χ(T) from analysis of χ(T) of all these alloys. Up-turns shown in χ(T) below 20 K grow as development of an energy gap ΔE. Those behaviors may be related to the second-gap development within the in-gap state showing metallic behaviors.

Using the equation of state of the electron-nuclear model at high densities and the mechanical equilibrium equation, we have investigated the influence of interparticle interactions and the axial rotation on the macroscopic characteristics (mass, surface shape) of massive degenerate dwarfs. We propose a method of solving the equilibrium equation in the case of rotation that uses the basis of universal functions of the radial variable. The conditions, under which the axial rotation can compensate for a weight loss of the mass due to the Coulomb interactions, have been established. The maximal value of the relativistic parameter, at which the stability is disturbed, is determined within the general theory of relativity (GTR).

It is shown that the maximum superconducting transition temperature, Tc for ZrP1.25Se0.75 is increased from 5.8 K to 7.2 K by partially substituting a non-magnetic rare earth atom Lu for Zr and on the other hand is decreased by substituting other non-magnetic rare earth atoms Y and La. Obviously, Tc is raised when lattice constants in the a-axis and the c-axis increase with replacing Zr. Its implications for further increasing Tc are discussed.

A magnetic braking and sensing technique developed as a potential alternative to assist with the non-contact deceleration and detection of explosively dispersed non-magnetic metallic particles is discussed. In order to verify the feasibility of such a technique and gain an understanding of how the underlying forces scale with particle size and velocity, a study was conducted whereby an aluminum particle moving along a spatially varying but time-invariant magnetic field was modeled and the corresponding experiment performed.

We evaluated an intrinsic α in ferromagnetic (FM)/non-magnetic (NM) junctions from first principles (FM = Co, Fe, and Ni and NM = Cu, Pd, and Pt) to investigate the effects of the inserted NM layer. α is calculated by liner muffin-tin orbital methods based on the torque-correlation model. We confirmed that Gilbert damping is enhanced and saturated as NM thickness increases, and that the enhancement is greater in NM materials having a stronger spin-orbital interaction. By contrast, the calculated FM thickness dependences of α show that Gilbert damping tends to decrease and be saturated as the FM thickness increases. Under the torque-correlation model, the dependences of α on FM and NM thickness can be explained by considering the electronic structure of the total system, including junction interfaces, which exhibit similar behaviors derived by spin pumping theory.