Abstract in spanish En este artículo se presenta la calibración del separador magnético de alta intensidad Magnet-lift MLH (13) 111-5 existente en el Laboratorio de Termocronología de la Universidad Central de Venezuela con la finalidad de separar magnéticamente minerales pertenecientes a areniscas y muestras graníticas para su posterior fechado por el método de huellas de fisión. Los resultados obtenidos de esta calibración fueron aplicados a una muestra de 10 kilogramos pertenecie (more) ntes a unaconcentración inicial de minerales de la Formación Betijoque del flanco norte de Los Andes Venezolanos. Se concluye que el Magnet-lift presenta amplias ventajas con respecto a los separadores magnéticos convencionales y además optimiza el tiempo de procesamiento de rocas detríticas que posteriormente serán fechadas por el método de datación empleado eneste laboratorio con el fin de discriminar la edad del último evento tecto-térmico ocurrido en la zona de estudio. Abstract in english In this article we present the calibration of a high intensity Magnet-lift MLH (13) 111-5 magnetic separator located in the Thermochronology Laboratory of the Universidad Central de Venezuela with the purpose of magnetically separating minerals of sandstone and granite samples to be subsequently subjected to the fission track dating method (FTDM). The results of this calibration were applied to 10 kilogram sample belonging to an initial concentration of minerals of Betijo (more) que´s Formation on the north flank of Venezuelans Andes. We conclude that the Magnet-lift presents a number of advantages with regard to conventional magnetic separators as well as optimizing the preparation time of detritic rocks for their dating by the fission track method.

Open gradient magnetic separators utilizing strong permanent magnets are used during a variety of magnetic carrier-based purification and bead coating processes such as protein separations, nucleic acid isolations, and immunodiagnostics. These purification and bead coating processes are often developed on a small, experimental scale before transfer to a functional process scale for use in industrial and manufacturing settings. Accordingly, the strong magnets used for magnetic carrier separation must be scaled to prevent process variation between batch size due to inadequate wash efficiency and discrepant capture times. Magnetic separator scalability may be defined as the consistent capture of magnetic particles as measured by capture time and capture efficiency (>99%) independent of collection vessel diameter. A mathematical relationship between the average magnetic field magnitude and the cross sectional vessel area has been devised for magnetic separators with magnets arranged in quadrature geometry. Using this correlation, the magnet thickness and material for each magnetic separator may be tailored to create the magnetic field strength and gradient required to achieve comparable capture times across different vessel diameters. Accordingly, four magnetic separators ranging in size from 0.125L to 1L were examined and demonstrated equivalent capture times of >99% microparticle capture at 60 seconds for phosphate buffered saline solutions containing 1% solids using Dynabead M-270 carboxylic acid microparticles. In addition, a 5L magnetic separator is also discussed. Magnetic scaling relationships and additional experimental outcomes using magnetic microparticles are described herein for the scaled magnetic separators.

A magnetic separator for separation of magnetic powder (iron trioxide ?-Fe2O3) from the chimney dust of a coal-fired power station is presented. The principle of the new version of separator is based on an iron screw-shaft with square thread which rotates in a dc magnetic field. Design, principle of operation and test results carried out on the magnetic separator are the subjects of the paper.

Magnetic separation of several classes of antibiotics was investigated using electrochemical magnetic seeding. Electrocoagulation with a sacrificial anode followed by addition of magnetite particles was applied for the magnetic seeding of antibiotics. With electrochemical magnetic seeding using an iron anode, tetracycline antibiotics (oxytetracycline, chlortetracycline, doxycycline and tetracycline) and cephalosporin antibiotic (cefdinir) were rapidly removed from synthetic wastewater by magnetic separation using a neodymium magnet. Iron and aluminium anodes were suitable for magnetic seeding of the antibiotics. The results indicated that the ability of antibiotics to form strong complex with iron and aluminium allowed the higher removal by magnetic separation. This method would be appropriate for rapid treatment of antibiotics in wastewater.

With the development of magnetic droplet-based biochips, the manipulation of magnetic droplets has become an important issue. In this study, deposited magnetic circular films are used to assist the positioning of magnetic microdroplets, which are separated from a mother droplet caused by the Rosensweig instability under a magnetic field. Magnetic microdroplets are attracted by the concentrated magnetic flux density caused by out-of-plane magnetization of the magnetic films, and magnetic films confine the positions of droplets. Through adjusting the applied field strength, droplet arrays with different number densities can be obtained. One-to-one correspondences between droplets and magnetic films can be achieved within specific magnetic field ranges.

Nowadays, ferrous materials are usually recovered from Municipal Solid Waste Incineration (MSWI) bottom ash by magnetic separation. To our knowledge, such a physical technique has not been applied so far to other MSWI residues. This study focuses thus on the applicability of magnetic separation on boiler fly ashes (BFA). Different types of magnet are used to extract the magnetic particles. We investigate the magnetic particle composition, as well as their leaching behaviour (EN 12457-1 leaching test). The magnetic particles present higher Cr, Fe, Mn and Ni concentration than the non-magnetic (NM) fraction. Magnetic separation does not improve the leachability of the NM fraction. To approximate industrial conditions, magnetic separation is also applied to BFA mixed with water by using a pil...

This paper describes three methods of separating the magnetic beads within fly ash from the ash itself, using the physical and chemical properties of the beads. Tests were performed on size, density, stability, magnetic material content, specific magnetic susceptibility, medium recovery oxidation resistance, and wear resistance of the magnetic beads from fly ash, in comparison with the magnetic fines currently used in dense media separation. It was shown that magnetic beads from fly ash may substitute for the magnetic fines currently used. 3 refs., 16 tabs.

Thick film magnetic/insulating nanocomposite materials, with significantly reduced core loss, and their manufacture are described. The insulator coated magnetic nanocomposite comprises one or more magnetic components, and an insulating component. The magnetic component comprises nanometer scale particles (about 1 to about 100 nanometers) coated by a thin-layered insulating phase. While the intergrain interaction between the immediate neighboring magnetic nanoparticles separated by the insulating phase provides the desired soft magnetic properties, the insulating material provides high resistivity, which reduces eddy current loss.

The application of superconducting bulk magnets to the magnetic separation techniques has been investigated for the Mn-bearing waste water drained from the university laboratories. The research has been conducted in comparison with the electromagnets, and the cryo-cooled superconducting solenoid magnet. The separation ratios of ferrite precipitates including Mn element in the waste slurry were estimated by means of the high gradient magnetic separation method with ferromagnetic iron filters in the water channel and open gradient magnetic separation without them. As the magnetic force acting on the particles is given by the product of a magnetization of particles and a gradient of magnetic field, and a superconducting bulk magnet shows a sharp gradient of the magnetic field on the surface, the performances of the bulk magnet system were almost equivalent to those of the superconducting solenoid magnet with wide bore with respect to the magnetic separation ratios. The separation ratios for Mn have reached over 80 % for HGMS and 10 % for OGMS under the flow rates less than 3 liter/min.

This Ph.D. thesis presents theory, modeling, design, fabrication, experiments and results for microfluidic magnetic separators. A model for magnetic bead movement in a microfluidic channel is presented, and the limits of the model are discussed. The effective magnetic field gradient is defined, and it is argued that it is a good measure, when comparing the performance of magnetic bead separators. It is described how numeric modelling is used to aid the design of microfluidic magnetic separation systems. An example of a design optimization study is given. A robust fabrication scheme has been developed for fabrication of silicon based systems. This fabrication scheme is explained, and it is shown how, it is applied with variations for several designs of magnetic separators. An experimental setup for magnetic separation experiments has been developed. It has been coupled with an image analysis program to facilitate real-time monitoring of the experiments. The set-up and experimental protocol are described in detail. Results are presented for ’active’ magnetic bead separators, where on-chip microfabricated electromagnets supply the magnetic field and field gradients necessary for magnetic bead separation. It is shown conceptually how such a system can be applied for parallel biochemical processing in a microfluidic system. ’Passive’ magnetic separators are presented, where on-chip soft magnetic elements are magnetized by an external magnetic field and create strong magnetic fields and gradients inside a microfluidic channel. Systems with the elements placed beside the microfluidic channel is combined with hydrodynamic focusing to demonstrate a magnetic bead microarray inside a microfluidic channel. Systems where the on-chip magnetic material is placed underneath the microfluidic channel are also presented. One of these designs feature multiple magnetic length scales, and it is shown that this enhances bead capture ability. A ’hybrid’ magnetic separator design, where the magnetic field from on-chip current lines couples with an externally applied homogenous field to create strong fields and gradients is demonstrated. This gives extra magnetic bead manipulation possibilities compared to the passive designs. It is demonstrated how this can be used for magnetic bead microarrays. Finally, it is discussed, based on the research presented in this thesis, how to further develop magnetic separation systems in microfluidic systems, and recommendations are given for the choice of magnetic design based on the desired application.

Superparamagnetic Iron Oxide Nanoparticles (SPIONs) are attractive because of some peculiar properties such as selective separation of biomolecules and cells, automated DNA extraction, targeted gene delivery, use as magnetic resonance contrast agent (MRI), and magnetic field induced hyperthermia for...

The designs of the bending, focusing, and correction magnetic for the storage ring are described. The computer-optimized pole-tip contours of the dipole, quadrupole, and sextupole magnets and the construction and assembly techniques keep the field errors within the specified limits. Horizontal and vertical steering corrections are provided by separate magnets in addition to a steering capability included in the sextupole magnets.

We present preliminary results for a magnetic flow spectrometer for magnetic microparticle separation, and a magnetic flow cytometer for particle identification. The application of the instrument is to high-throughput bioassay. Here we report on the first application of our magnetic spectrometer to the sorting of ferromagnetic and superparamagnetic microspheres in flow. The system is based on a permanent magnet quadrupole and separates the polymer coated magnetic microspheres based on their magnetic moments. The cryogenic section of our magnetic flow cytometer, which involves SQUID-based detection of the sorted magnetic microspheres based on their magnetic moments, has been re-engineered to permit a smaller standoff between the SQUID array and the flowing magnetic particles. We present preliminary results with the new experimental setup, with an emphasis on both spatial and signal resolution.

The Quadrupole Magnetic Sorter (QMS), employing an annular flow channel concentric with the aperture of a quadrupole magnet, is well established for cell and particle separations. Here we propose a magnetic particle separator comprising a linear array of cylindrical magnets, analogous to the array proposed by Klaus Halbach, mated to a substantially improved form of a parallel plate SPLITT channel, known as the step-SPLITT channel. While the magnetic force and throughput are generally lower than for the QMS, the new separator has advantages in ease of fabrication and the ability to vary the magnetic force to suit the separands. Preliminary experiments yield results consistent with prediction and show promise regarding future separations of cells of biomedical interest. - Research highlights: Novel pairing of an adapted linear Halbach magnet array and step-SPLITT channel is carried out. Unlike QMS, it allows variation in mean magnetic force as well as the gravity component. The magnetic force is easily controlled by varying the channel-magnet distance. Magnetic particle separations behave predictably when varying the flow rate and distance. Separations match prediction with good enrichment of magnetic particles in mixture.

'The objective is to reduce the volume and cost of high-level waste glass produced during US DOE remediation activities by demonstrating that magnetic separation can separate crystalline, amorphous, and colloidal constituents in vitrification feed streams known to be deleterious to the production of borosilicate glass. Magnetic separation will add neither chemicals nor generate secondary waste streams. The project includes the systematic study of magnetic interactions of waste constituents under controlled physical and chemical conditions (e.g., hydration, oxidation, temperature) to identify mechanisms that control the magnetic properties. Partitioning of radionuclides to determine their sorption mechanisms is also being studied. The identification of fundamental magnetic properties within the microscopic chemical environment in combination with hydrodynamic and electrodynamic models provides insights into the design of a system for optimal separation. Following this, experimental studies using superconducting open-gradient magnetic separation (OGMS) will be conducted to validate its effectiveness as a pretreatment technique.'

Flocculation and filtration of micrometer-sized particles in a high-gradient magnetic field (HGMF) were investigated. Experiments were conducted using a cryogenic magnet of 6 Tesla maximum strength. Hematite particles were used for flocculation and filtration experiments. A new approach of using magnetic fields to enhance separation of weakly magnetic particles was also investigated. This approach is based on magnetic seeding which involves flocculation of existing non-magnetic particles with injected paramagnetic particles. A particle-flocculation model was developed based on trajectory analysis. External forces due to gravity and magnetism, and interparticle forces such as electrostatic, hydrodynamic, magnetic dipole, and van der Waals forces, were taken into consideration in these models.

In this article a novel design of on-chip continuous magnetophoretic separator was proposed by utilizing the magnetic field and L-turning/T-junction effect of the flow field for high throughput applications. The motion of the magnetic bead was simulated based on Lagrangian tracking method and the separation efficiency was calculated according to the trajectories. Impact parameters including geometrical configuration, fluid velocity, magnetic flux density, magnetic bead size, and temperature on separation efficiency were discussed. The results show that both the L- and T-microchannel separators have higher separation efficiency as compared with the conventional straight-microchannel separator because of the L-turning/T-junction effect of the flow field. The separation efficiencies for L- an...

A recovery method for electrode compounds from waste nickel metal hydride batteries by physical separation using sizing and distance-variable magnetic separation was investigated. The electrodes are formed by bonding substances of substrate and fine activating agents. Fine particle separation causes increasing costs and decreasing separation efficiency, suggesting a treatment flow where the separation of the anodic compounds from the cathodic compounds is carried out first and then each compound is crushed again for the liberation of activating agents and substrate. There is no suitable magnetic separation equipment to separate ferromagnetic substances using the magnetic property differences in the substrate components and special equipment to achieve this was developed. Using this newly developed equipment resulted in good separation.   

Magnetically separable ordered mesoporous carbon with Fe3O4 nanoparticles, which were grafted on the outer surface of the mesoporous carbon material CMK-3, was prepared through a facile route. The catalytic performance for hydrogenation of cyclohexene to cyclohexane validates the mesoporous nanocomposite material as a promising magnetically separable catalyst support.   

High Gradient Magnetic Separation (HGMS) is an application of superconducting magnet technology to the separation of magnetic solids from other solids, liquids, or gases. The production of both high magnetic fields (>4 T) and large field gradients using superconducting magnet technology has made it possible to separate a previously unreachable but large family of paramagnetic materials. This is a powerful technique that can be used to separate widely dispersed contaminants from a host material and may be the only technique available for separating material in the colloidal state. Because it is a physical separation process, no additional waste is generated. We are applying this technology to the treatment of radioactive wastes for environmental remediation. We have conducted tests examining slurries containing nonradioactive, magnetic surrogates. Results from these studies were used to verify our analytical model of the separation process. The model describes the rate process for magnetic separation and is based on a force balance on the paramagnetic species. This model was used to support bench scale experiments and prototype separator design.

Separations is a critical element of any pollution prevention technology portfolio because of its applicability to a broad set of problems. The range of technologies included in separations is diverse and ranges from chemical engineering unit operations such as distillation and extraction to gas separation via adsorption and membranes to solids separations via classifiers and magnetic fields. The discussions in this chapter focus on separations technologies as used in pollution prevention.

High gradient magnetic separation (HGMS) is a physical separation process that is used to extract magnetic particles from mixtures. The technology is used on a large scale in the kaolin clay industry to whiten or brighten kaolin clay and increase its value. Because all uranium and plutonium compounds are slightly magnetic, HGMS can be used to separate these contaminants from non-magnetic soils. A Cooperative Research and Development Agreement (CRADA) was signed in 1992 between Los Alamos National Laboratory (LANL) and Lockheed Environmental Systems and Technologies Company (LESAT) to develop HGMS for soil decontamination. This paper reports progress and describes the HGMS technology.

In this study, the focus is on magnetic separation of fresh water algae Chlamydomonas reinhardtii and Chlorella vulgaris as well as marine algae Phaeodactylum tricornutum and Nannochloropsis salina by means of silica-coated magnetic particles. Due to their small size and low biomass concentrations, harvesting algae by conventional methods is often inefficient and cost-consuming. Magnetic separation is a powerful tool to capture algae by adsorption to submicron-sized magnetic particles. Hereby, separation efficiency depends on parameters such as particle concentration, pH and medium composition. Separation efficiencies of >95% were obtained for all algae while maximum particle loads of 30 and 77 g/g were measured for C. reinhardtii and P. tricornutum at pH 8 and 12, respectively. This study highlights the potential of silica-coated magnetic particles for the removal of fresh water and marine algae by high gradient magnetic filtration and provides critical discussion on future improvements. PMID:22705536

We present a theoretical analysis of a new design for microfluidic magnetic bead separation. It combines an external array of mm-sized permanent magnets with magnetization directions alternating between up and down with mu m-sized soft magnetic structures integrated in the bottom of the separation channel. The concept is studied analytically for simple representative geometries and by numerical simulation of an experimentally realistic system geometry. The array of permanent magnets provides long-range magnetic forces that attract the beads to the channel bottom, while the soft magnetic elements provide strong local retaining forces that prevent captured beads from being torn loose by the fluid drag. The addition of the soft magnetic elements increases the maximum retaining force by two orders of magnitude. The design is scalable and provides an efficient and simple solution to the capture of large amounts of magnetic beads on a microsystem platform.

Single particle magnetization and size measurements of micron and nano sized, magnetic particles were made using a previously described device referred to as Cell Tracking Velocimetry (CTV). Three types of commercially available, and commonly used, magnetic particles were studied in this report. While the CTV instrument provides individual particles measurements, the average magnetization and size measurements were found to have reasonable agreements with reported values from instruments which measure bulk values. In addition, the CTV instrument, using electromagnets, can also determine magnetization curves, which also proved to have reasonable agreement with other published studies. Given that magnetic separation and analysis technology is dependent on the quality of the magnetic particle...

A freely oriented portable superconducting magnet is disclosed. Coolant is supplied to the superconducting magnet from a repository separate from the magnet, enabling portability of the magnet. A plurality of support assemblies structurally anchor and thermally isolate the magnet within a thermal shield. A plurality of support assemblies structurally anchor and thermally isolate the thermal shield within a vacuum vessel. The support assemblies restrain movement of the magnet resulting from energizing and cooldown, as well as from changes in orientation, enabling the magnet to be freely orientable.

Magnetic solids are widely used in detection and analytical systems because of the performance advantages they offer compared to similar solids that lack magnetic properties. These solids can be used to pre-concentrate analytes and for the magnetic separation and molecular identification of biomolecules, and organic and inorganic species. Magnetic solid separation techniques also offer benefits over centrifugation, filtration, and solid-phase extraction. In this review, we describe the synthesis, characterization and applications of a series of solids including silica supports, carbon nanotubes, alumina, organic polymers and other materials, mostly containing magnetite or paramagnetic metals. Also addressed are the future perspectives of magnetic solid applications. PMID:20678625

A model of magnetic phase transitions in plasmas is presented: plasma elements with pressure excess or defect are dia- or paramagnets and move radially under the influence of the background plasma magnetization. It is found that magnetic phase separation could be the underlying mechanism of L to H transitions and drive transport barrier formation. Magnetic phase separation and the associated pedestal build-up, as described here, can be explained by the well-known interchange mechanism, now reinterpreted as a magnetization interchange. The interchange mechanism can drive motion of plasma elements even when stable. A testable necessary criterion for the L to H transition is presented.

The fundamental chemistry for selective adsorption of magnetizing reagent on coal-associated minerals to enhance the magnetic susceptibilities of minerals have been established in Phase I study. The application of the results to study the feasibility for coal cleaning has been completed in the Phase II study. The most effective approach to clean Illinois No. 6, Ohio Lower Kittanning, and West Virginia Pocahontas coals using the magnetizing method has been determined. Phase III study is in progress during this quarter. Experimental work includes the determination of various separation parameters, including the separator and matrix selection, magnetic reagent dosage, particle size, magnetic field intensity, and retention time.

The structural and magnetic properties of the Tm0.65Sr0.35Mn1 - x Fe x O3 ( x = 0.3-0.4) have been studied by methods of magnetic resonance and differential thermomagnetic analysis. A magnetic phase separation has been revealed in structurally single-phase samples.

The magnetic susceptibility of Escherichia coli (E. coli) was measured by the Faraday balance technique using a microcomputer controlled Cahn balance. The volume magnetic susceptibility of E. Coli is determined to be approximately 1X10-6 (SI units). The high gradient magnetic separation (HGMS) method for capturing aerobic E. coli in its supernatant fluid is determined to have a maximum efficiency of 42%.

We propose an analytical computation of the magnetic field distribution in a magnetic gear. The analytical method is based on the resolution of Laplace's and Poisson's equations (by the separation of variables technique) for each subdomain, i.e., magnets, air gap, and slots. The global solution is o...

A Hall effect plasma accelerator includes inner and outer electromagnets, circumferentially surrounding the inner electromagnet along a thruster centerline axis and separated therefrom, inner and outer magnetic conductors, in physical connection with their respective inner and outer electromagnets, with the inner magnetic conductor having a mostly circular shape and the outer magnetic conductor having a mostly annular shape, a discharge chamber, located between the inner and outer magnetic conductors, a magnetically conducting back plate, in magnetic contact with the inner and outer magnetic conductors, and a combined anode electrode/gaseous propellant distributor, located at a bottom portion of the discharge chamber. The inner and outer electromagnets, the inner and outer magnetic conductors and the magnetically conducting back plate form a magnetic circuit that produces a magnetic field that is largely axial and radially symmetric with respect to the thruster centerline.

The coefficients of mass separation have been calculated for gas mixtures in crossed electric and magnetic fields. The initial kinetic equations have been derived, and the contribution of centrifugal and charge separation mechanisms to mass separation in a weakly ionized plasma has been assessed.

An atomic vapor laser isotope separation in lithium was performed using tunable diode lasers. The method permits also the separation of the isotopes between the sup 6 LiD sub 2 and the sup 7 LiD sub 1 lines using a self-made mass separator which includes a magnetic sector and an ion beam designed for lithium. (Author)

An earlier experimental program tested the separation of pyritic sulfur and ash-forming minerals from dry crushed coal in a small, cyclic, high-gradient magnetic separator over a range of each of the process parameters. That experimental program defined a band of operating conditions that affected reductions of the mineral contaminants and recoveries of the heating value comparable to gravimetric separations. This report describes the procedures and results of an experimental program to extrapolate from the small, cyclic separations to continuous, pilot-scale separation at a feed rate of 1 ton/h. The program at the Oak Ridge National Laboratory testing magnetic preparation of dry crushed coal has demonstrated that: (1) Dry crushed coal in the size range of about 600 x 45 ..mu.. can be effectively cleaned by magnetic separation techniques; (2) Product quality and heating value recovery by the high-gradient magnetic process approaches that obtained by a laboratory gravimetric separation of the same size fraction; and (3) Separations performed on size fractions from 600 to 45 ..mu.. at a feed rate of 1 ton/h in a continuous, industrial-type high-gradient magnetic separator equal those obtained in a cyclic laboratory separator.

The program consisted of a fundamental study to define the chemistry for the interactions between magnetic reagent and mineral and coal particles, a laboratory study to determine the applicability of this technology on coal cleaning, and a parameter study to evaluate the technical and economical feasibility of this technology for desulfurization and de-ashing under various processing schemes. Surface magnetic enhancement using magnetic reagent is a new technology developed at the Institute. This technology can be applied to separate pyrite and other minerals particles from coal with a magnetic separation after adsorbing magnetic reagent on the surface of pyrite and other minerals particles. Particles which have absorbed magnetic reagent are rendered magnetic. The adsorption can be controlled to yield selectivity. Thus, the separation of traditionally nonmagnetic materials with a magnetic separator can be achieved. Experiments have been performed to demonstrate the theoretical fundamentals and the applications of the technology. Adsorbability, adsorption mechanisms, and adsorption selectivity are included in the fundamental study. The effects of particle size, magnetic reagent dosage, solid contents, magnetic matrix, applied magnetic field strengths, retention times, and feed loading capacities are included in the application studies. Three coals, including Illinois No. 6, Lower Kittanning and Pocahontas seams, have been investigated. More than 90% pyritic sulfur and ash reductions have been achieved. Technical and economic feasibilities of this technology have been demonstrated in this study. Both are competitive to that of the froth flotation approach for coal cleaning.

We present the design, fabrication, characterization, and demonstration of a new passive magnetic bead separator. The device operates in an effective state when magnetized by an external magnetic field of only 50 mT, which is available from a tabletop electromagnet. We demonstrate the complete capture of 1.0 mu m fluorescent magnetic beads from a 7.5 mu L sample volume traveling at an average linear fluid velocity of 5 mm/s.

We present a theoretical study of the spatially averaged in-plane magnetic field on square and rectangular magnetic field sensors from a single magnetic bead, a monolayer of magnetic beads, and a half-space filled with magnetic beads being magnetized by the magnetic self-field due to the applied bias current through the sensor. The analysis of the single bead response shows that beads always contribute positively to the average magnetic field as opposed to the case for an applied homogeneous magnetic field where the sign of the signal depends on the bead position. General expressions and analytical approximations are derived for the sensor response to beads as function of the bead distribution, the bias current, the geometry and size of the sensor, and the bead characteristics. Consequences for the sensor design are exemplified and it is described how the contribution from the self-field experimentally can be separated from that due to static magnetic fields.

In order to save computer memory, a long accelerator magnet may be computed by treating the long central region and the end regions separately. The dipole magnets for the injector synchrotron of the Advanced Photon Source (APS), now under construction at Argonne National Laboratory (ANL), employ magnet iron consisting of parallel laminations, stacked with a uniform radius of curvature of 33.379 m. Laplace's equation for the magnetic scalar potential has a different form for a straight magnet (x-y coordinates), a magnet with surfaces curved about a common center (r-{theta} coordinates), and a magnet with parallel laminations like the APS injector dipole. Yet pseudo 2-D computations for the three geometries give basically identical results, even for a much more strongly curved magnet. Hence 2-D (x-y) computations of the central region and 3-D computations of the end regions can be combined to determine the overall magnetic behavior of the magnets. 1 ref., 6 figs.

Magnetic energy is one the main agents powering our society: generating energy in power plants, keeping information in magnetic memories, moving our devices with motors. All of these applications require a certain spatial distribution of magnetic energy, for example concentrating it in a transformer core or in a magnetic sensor. We introduce in this work a way to collect magnetic energy and distribute it in space with unprecedented efficiency and flexibility, allowing very large concentration of magnetic energy in a free space region, an enhanced magnetic coupling between two magnetic sources, and the transfer of magnetic energy from a source to a given distant point separated by empty space. All these features are achieved with a single device, a magnetic shell designed by transformation optics.

Abstract Full-Eulerian simulation of the separation of magnetic particles carried by a Newtonian fluid through a planar channel under the influence of a magnetic field is presented. The simulation is based on the application of the Navier-Stokes and concentration equations. The scheme for the magnetic separation of particles is achieved by applying an external magnetic dipole field. The hydrodynamic and magnetophoretic interactions between the particles and the carrier fluid are analysed. Analysis of the competing tendencies of mass transfer indicates that the magnetophoresis migration of magnetic particles is dominant over the molecular diffusion. This dominance becomes more evident at lower diffusivities leading to a drastic magnetic separation confined within a small region in the proxi...

The progress achieved during this quarter includes the ten months shelf life study of magnetizing reagent, the effect of cation regulators on minerals and coals, the combination effect of depressant and activator on the adsorption of magnetizing reagent, optimum magnetite size for magnetizing reagent, and the magnetic field strength for separating magnetic enhanced minerals. The work is generally on schedule with the original plan. The Phase I study (a fundamental study) is nearly completed. Selective conditions for adsorbing magnetizing reagent on minerals have been identified. The work for the next quarter will be mainly on the Phase II study. Coal will be selected, procured, characterized, and processed.

We use electromagnetic and magnetic shielding materials to protect environment from EMI or to obtain lower electromagnetic field room. Magnetic materials are used for shielding magnetic field that is the electromagnetic field less than 10 kHz. Electromagnetic shielding is for the field over 10kHz. The shielding principle by electromagnetic shielding materials is to reflect or absorb electromagnetic wave, whereas that by magnetic shielding materials is to collect and flow magnetic flux. Here, we explain electromagnetic and magnetic shielding materials in separated sections on basic properties and examples for practical use. (author)

A process for selectively removing metal values which may include catalytic values from a mixture containing same, wherein a magnetic particle is contacted with a liquid solvent which selectively dissolves the metal values to absorb the liquid solvent onto the magnetic particle. Thereafter the solvent-containing magnetic particles are contacted with a mixture containing the heavy metal values to transfer metal values into the solvent carried by the magnetic particles, and then magnetically separating the magnetic particles. Ion exchange resins may be used for selective solvents.

We present a simple technique for creating an on-chip magnetic particle conveyor based on exchange-biased permalloy microstripes. The particle transportation relies on an array of stripes with a spacing smaller than their width in conjunction with a periodic sequence of four different externally applied magnetic fields. We demonstrate the controlled transportation of a large population of particles over several millimeters of distance as well as the spatial separation of two populations of magnetic particles with different magnetophoretic mobilities. The technique can be used for the controlled selective manipulation and separation of magnetically labelled species. (C) 2012 American Institute of Physics.

Crystallographic, magnetic and NMR properties of a NaxCoO2 single crystal with x~1 are presented. We identify the stoichiometric Na1CoO2 phase, which is shown to be a non-magnetic insulator, as expected for homogeneous planes of Co3+ ions with S=0. In addition, we present evidence that, because of slight average Na deficiency, chemical and electronic phase separation leads to a segregation of Na vacancies into the well-defined, magnetic, Na0.8CoO2 phase. The importance of phase separation is discussed in the context of magnetic order for x~0.8 and the occurrence of a metal-insulator transition for x->1.

Because of their extremely large surface area, carbon nano tubes (CNTs) and carbon nano fibers (CNFs) have been widely used to remove heavy metals from water. But the removal of such CNTs and CNFs from water is another important aspect in water purification process. In the present work, we discuss CNT and CNF separation from water using a magnetic separation technique. In order to compare the separation efficiencies, CNTs and CNFs having wide variation in their magnetic properties were selected. The effects of CNT and CNF concentrations in untreated water and water flow velocity on the separation efficiency were investigated systematically.   

A new method to implement an asymmetrical two-dimensional magnetic lattice is proposed. The asymmetrical two-dimensional magnetic lattice can be created by periodically distributing magnetic minima across the surface of magnetic thin film where the periodicity can be achieved by milling $n\\times n$ square holes on the surface of the film. The quantum device is proposed for trapping and confining ultracold atoms and quantum degenerate gases prepared in the low magnetic field seeking-state at low temperature, such as the Bose-Einstein Condensate (BEC) and ultracold fermions. We present detailed analysis of the analytical expressions and the numerical simulation procedure used to calculate the external magnetic field. We also, describe the magnetic band gap structure exhibited by the asymmetric effect of the magnetic minima and show some of the possible application. We analyze the effect of changing the characteristic parameters of the magnetic lattice, such as the separating periodicity length and the hole size...

Magnetic particles for medical applications have been developed by many researchers. Since magnetic particles have unique magnetic features not present in other materials, they can be applied to special medical techniques. Separation, immunoassay, magnetic resonance imaging (MRI), drug delivery, and hyperthermia are enhanced by the use of magnetic particles. Magnetite cationic liposomes (MCLs), one of the group of cationic magnetic particles, can be used as carriers to introduce DNA into cells since their positively charged surface associates with the negatively charged DNA. They can also be used as heat mediators for cancer therapy. Magnetic particles conjugated with tumor-specific antibodies have enabled tumor-specific contrast enhancement in MRI. In addition, antibody-conjugated magnetic particles were shown to target renal cell carcinoma cells, and are applicable to the hyperthermic treatment of carcinomas. The use of magnetic particles with their unique features will further improve medical techniques.   

A portable separator has been developed to quantitatively separate blood-borne magnetic spheres in potentially high-flow regimes for the human detoxification purpose. In the separator design, an array of biocompatible capillary tubing and magnetizable wires is immersed in an external magnetic field that is generated by two permanent magnets. The wires are magnetized and the high magnetic field gradient from the magnetized wires helps to collect blood-borne magnetic nano/micro-spheres from the blood flow. In this study, a 3D numerical model was created and the effect of tubing-wire configurations on the capture efficiency of the system was analyzed using COMSOL Multiphysics 3.3{reg_sign}. The results showed that the configuration characterized by bi-directionally alternating wires and tubes was the best design with respect to the four starting configurations. Preliminary in vitro experiments verified the numerical predictions. The results helped us to optimize a prototype portable magnetic separator that is suitable for rapid sequestration of magnetic nano/micro-spheres from the human blood stream while accommodating necessary clinical boundary conditions.

In this study, the focus is on magnetic separation of fresh water algae Chlamydomonas reinhardtii and Chlorella vulgaris as well as marine algae Phaeodactylum tricornutum and Nannochloropsis salina by means of silica-coated magnetic particles. Due to their small size and low biomass concentrations, harvesting algae by conventional methods is often inefficient and cost-consuming. Magnetic separation is a powerful tool to capture algae by adsorption to submicron-sized magnetic particles. Hereby, separation efficiency depends on parameters such as particle concentration, pH and medium composition. Separation efficiencies of >95% were obtained for all algae while maximum particle loads of 30 and 77g/g were measured for C. reinhardtii and P. tricornutum at pH 8 and 12, respectively. This study ...

QED. As such, the property Eq. (3.7) is shared by any solver of Eq. (1.1) which ...... Bed (SMB) Chromatographic Separation Problems, Chemical Engineering ... tions Without Special Treatment for Divergence-Free Magnetic Field, AIAA J., ...

NASA, the alternator windings will operate in a helium-xenon gas mixture which may .... alumina (AlgOo) slot liners and separators and Anadur insulated nickel magnet .... therefore measured with the alternator placed inside a shielded test ...

Linear birefringence and optical activity are considered separately for electromagnetic wave propagation in magnetized cold plasma, using frequency approximation much bigger than plasma frequency. It is shown that in some interesting cases, those phenomen...

magnetic separation, Mossbauer spectroscopy, and microscopic examination. R. M. Housley, R. W. ..... Since this sample was composed largely of glass- welded ... optically resolvable metallic phase can be found in the majority of particles in ...

oxidation at 11UK and 114OK and the reduction of pseudobrookite (Fe2TiOs) ...... stony fraction through magnetic and gaseous digestion separation techniques. ..... tains ores of chromium and Pt-group metals, illustrates the sort of dry-magma ...

The second part of this paper is concerned with techniques of oil agglomeration, high gradient magnetic separation, biological oxidation and chemical cleaning. Brief descriptions of several of the processes are given.

This review of the history of early atomic clocks includes early atomic beam magnetic resonance, methods of separated and successive oscillatory fields, microwave absorption, optical pumping and atomic masers. (author)

A high-gradient magnetic separator was used in tests of Nishiyama, Miller and Tatung coals. It was discovered that pyrite and siderite could be removed; that calcite and feldspar, which contain iron and other impurities, could be concentrated; and that incomplete separation of clay minerals was possible. The relation between magnetic field strength, coal solution flow rate, percentage ash removal and coal yield was clarified, and light was also thrown on the relation between flow rate and magnetic field strength, both of which affect the percentage pyrite removal. Considerations of yield lead the authors to recommend low magnetic field separation followed by cleaning of impurities which have not adhered to the magnet. 6 references.

Scandium (Sc) concentration from the rare earth ore by high gradient magnetic separation (HGMS) was determined on the basis of Sc content, geophysical parameter determination and the magnetic analyses of the ore. Based on the condition experiments, expanding experiments were carried out. The results showed that the ore had a Sc grade of 48.90 g/t, and after removing iron by low-intensity magnetic separation, a Sc concentrate of 314.89 g/t grade and with 77.53% recovery was obtained by one-stage roughing-one-stage cleaning of high gradient magnetic separation. Most of the rare earth elements were enriched in the Sc concentrate, and some could be comprehensively recovered during Sc extraction. It was therefore concluded that most of the rare earth elements in the weakly magnetic minerals cou...

The ion optics of an existing mass separator are documented. The elctrostatic and magnetic stages are analyzed theoretically, both separately and in combination, by paying particular attention to the ion trajectories, the linear and angular magnifications, and the dispersion. The possibility of converting the magnet into a tunable unit by means of current-carrying elements in the gap is demonstrated. The feasibility of correction coils constructed from printed circuit board is shown.

A magnetically stabilized fluidized-bed separator designed to test the use of pellicular, ferromagnetic affinity chromatography packing materials has been developed. A wire wound solenoid was used to produce the magnetic field. The ferromagnetic packing material is comprised of a magnetite-containing, polyurethane gel coated onto polystyrene beads. The gel contains free carboxyl groups. These were carbodiimide-coupled to soy trypsin inhibitor and the material used for trypsin purification. Narrow-band affinity chromatography was carried out in packed-bed, fluidized-bed, and magnetically stabilized, fluidized-bed separators. Pressure drop, capacity, dilution, and peak asymmetry were evaluated for each type of separator. The three types provide comparable efficiency but the fluidized separators exhibit a much lower pressure drop. As might be expected, fluidized-bed separators perform well for affinity chromatography (large k') but poorly for size exclusion chromatography.

The authors report on the ramp rate testing of a prototype high temperature superconducting (HTS) high gradient magnetic separation (HGMS) magnet. HGMS magnets are ramped from full field to zero field to clean the separation matrix. The time spent ramping the magnet is unavailable for processing and must therefore be kept to a minimum. Existing commercial low temperature superconducting HGMS magnets are immersed in a liquid helium bath and are designed to ramp from zero to full current in one minute. The HTS magnet in the system is conductively cooled and operates in a vacuum at a temperature of approximately 30 K. Heat generated during ramping is not as readily removed from the conductively cooled magnet as a bath cooled magnet. To verify that the conductive cooling can adequately remove heat generated during ramping they recorded magnet temperatures and voltages while ramping at rates of up to 4.8 A/second. The magnet can accommodate ramps from zero to 100 A (1.6 Tesla) in 21 seconds with no degradation in performance. The average magnet temperature rises a maximum of 1 K during ramping. Using temperatures recorded during ramps they have made rough estimates of the ac losses generated in the magnet.

The electronic structure and magnetism of coherent modulated structures of CuNi for varying numbers of Cu and Ni layers modulated along (111) and (100) directions has been determined theoretically by means of self-consistent spin polarized LMTO energy band studies and compared with experiment and with theoretical results separately obtained for bulk fcc and tetragonally distorted Ni metal. The magnetic moments in the Ni layers in CuNi are found to be reduced relative to that of fcc Ni indicating that the enhanced magnetism deduced from earlier ferromagnetic resonance observations must arise from other sources. These predictions have been confirmed recently by direct magnetization and neutron magnetic scattering studies.

We have built active magnetic regenerator (AMR) test apparatuses operated with a gas displacer to transfer the heat from magnetic material unit (AMR bed). Because finding an optimum parameter by experiment is not easy, numerical simulation is necessary to confirm the experimental conditions. As the first step of the project, we developed a 1-dimensional porous media model for hydrogen magnetic refrigerator with a Brayton-likeoperation cycle. This model has been calculated separately for heat exchange fluid and magnetic material. The results using two different magnetic materials have been compared.We confirmed that the simulation results agreed with experimental data of the internal gas displacer system.

The nanotechnology industry is rapidly growing and promises that the substantial changes that will have significant economic and scientific impacts be applicable to a wide range of areas, such as aerospace engineering, nano-electronics, environmental remediation and medical healthcare. In this area, cobalt ferrite nanoparticles have been regarded as one of the competitive candidates because of their suitable physical, chemical and magnetic properties like the high anisotropy constant, high coercivity and high Curie temperature, moderate saturation magnetization and ease of synthesis. This paper introduces the magnetic properties, synthesis methods and some medical applications, including the hyperthermia, magnetic resonance imaging (MRI), magnetic separation and drug delivery of cobalt fer...

The magnet system of the Very Large Hadron Collider (VLHC) Stage I is based on a superconducting 2 Tesla magnetic field combined function magnets. These magnets will have a room temperature iron core with two 20 mm air gaps. Magnetic field in both horizontally separated air gaps is excited by a single turn 100 kA superconducting transmission line. The alternative design with cold iron core, horizontally or vertically separated air gaps is under investigation. The cold iron option with horizontally separated air gaps reduces the amount of iron, which is one of the main cost driver for 233 km length magnet system of the future accelerator. The vertical beam separation decreases volume superconductor, heat load from synchrotron radiation and eliminates fringing field from a return bus. But the horizontal beam separation has lowest volume of iron core and as a result lower heat load for cryosystem during cooling down. All these options are discussed and comparison is made. Superconducting correction system, combined with the magnet, allowing to increase the maximum field is also under discussion. Preliminary cost analysis are made for all options.

Uncovering the physical mechanisms that govern ultrafast charge and spin dynamics is crucial for understanding correlated matter as well as the fundamental limits of ultrafast spin-based electronics. Spin dynamics in magnetic materials can be driven by ultrashort light pulses, resulting in a transient drop in magnetization within a few hundred femtoseconds. However, a full understanding of femtosecond spin dynamics remains elusive. Here we spatially separate the spin dynamics using Ni/Ru/Fe magnetic trilayers, where the Ni and Fe layers can be ferro- or antiferromagnetically coupled. By exciting the layers with a laser pulse and probing the magnetization response simultaneously but separately in Ni and Fe, we surprisingly find that optically induced demagnetization of the Ni layer transiently enhances the magnetization of the Fe layer when the two layer magnetizations are initially aligned parallel. Our observations are explained by a laser-generated superdiffusive spin current between the layers.

Students begin working on the grand challenge of the unit by thinking about the nature of metals and quick, cost-effective means of separating different metals, especially steel. They arrive at the idea, with the help of input from relevant sources, to use magnets, but first they must determine if the magnets can indeed isolate only the steel.

Differential thermal analysis is used to measure the temperature change (?T) due to the application of an external magnetic field in a manganite with phase separation. The temperature dependence of ?T is compared with the expected from magnetization measurements. A phenomenological model for the enthalpy change is used to obtain ?T during the metamagnetic transition.

A latching relay switch assembly which includes a coil section and a switch or contact section. The coil section includes at least one permanent magnet and at least one electromagnet. The respective sections are, generally, arranged in separate locations or cavities in the assembly. The switch is latched by a permanent magnet assembly and selectively switched by an overriding electromagnetic assembly.

Amounts of amino acids adsorbed onto the Au/{gamma}-Fe{sub 2}O{sub 3} composite nanoparticles synthesized by gamma-ray irradiation were measured using magnetic separation technique. Cystine and methionine, which are sulfur-containing amino acids, connected to Au by a Au-S bond could be selectively picked up by a magnet.

A Continuous Flow Separation (CFS) technique is introduced, which operates uninterruptedly, without the use of a magnetic filter matrix. CFS is based on selective magnetosedimentation, in a field gradient introduced by the processing magnet itself. A laboratory scale continuous flow system has been ...

This thesis deals with the interaction of spin-polarized currents with the spin configuration in magnetic wires and disks. The samples are studied by high resolution X-ray magnetic circular dichroism - photo emission electron microscopy and the experiments can be separated in two groups. The study o...

Fly ash specimens from four power plants in the Tennessee Valley Authority system have been separated into three matrices: glass, mullite-quartz, and magnetic spinel. Chemical species of trace elements are defined to a large extent by the matrices that contain them. The magnetic component of fly ash is ferrite. The mullit-quartz phase is relatively pure and can be recovered as a resource.

The ligand, benzophenone-2,4'-dicarboxylate, was used as a polytopic linker and magnetic separator to bridge the inorganic hydroxide-bridged cobat(ii) chain motifs into a laminar inorganic-organic hybrid materials with nearest inter-chain Co(ii)Co(ii) distance of ca. 8.14 A, which exhibits single-chain magnet behaviour. PMID:19259557

A gigantic three orders of magnitude change of resistivity in La(0.67)Sr(0.33)MnO(3) (LSMO) thin film, on application of magnetic field, has been observed. The transport and magnetic properties are characteristic of electronic phase separation between ferromagnetic metallic and antiferromagnetic charge-ordered insulating regions, unusual for a canonical double exchange system such as LSMO. PMID:21814010

In manufacturing a DC motor body including a motor magnet by conventional processes, a magnet is fitted to the cylindrical molding core and a motor body is injection-molded within a cavity formed between a motor-body-forming mold and a cylindrical molding core to which the magnet is attached. Therefore, the magnet has to be molded and stocked before molding the motor body, thus being inapplicable to mass-production processes. To overcome these problems, the motor magnet and the motor body are molded in sequence in accordance with two separate molding steps by the use of the same molding core. This method can eliminate troublesome magnet fitting work and the need of magnet stock, and enhance the dimensional precision of motor magnet, thus being applicable to mass-production process while increasing the energy transduction efficiency of the DC motor.

Magnetic elements are thought to be described by flux tube models, and are well reproduced by MHD simulations. However, these simulations are only partially constrained by observations. We observationally investigate the relationship between G-band bright points and magnetic structures to clarify conditions, which make magnetic structures bright in G-band. The G-band filtergrams together with magnetograms and dopplergrams were taken for a plage region covered by abnormal granules as well as ubiquitous G-band bright points, using the Swedish 1-m Solar Telescope (SST) under very good seeing conditions. High magnetic flux density regions are not necessarily associated with G-band bright points. We refer to the observed extended areas with high magnetic flux density as magnetic islands to separate them from magnetic elements. We discover that G-band bright points tend to be located near the boundary of such magnetic islands. The concentration of G-band bright points decreases with inward distance from the boundar...

Ruderman–Kittel–Kasuya–Yosida interaction is an indirect magnetic coupling between localized spins in a non-magnetic host mediated by conduction electrons. In diluted systems it is often the dominating magnetic interaction and has played a key part in the development of giant magnetoresistance devices, drives ferromagnetism in heavy rare-earth elements as well as in diluted magnetic semiconductors and gives rise to complex magnetic phases such as spin glasses. For bulk systems, an isotropic and continuous model of Ruderman–Kittel–Kasuya–Yosida interaction is often sufficient. However, it can be misleading in magnetic nanostructures consisting of separate magnetic atoms adsorbed on the surface of a non-magnetic material. Here, an atomically precise map of...

Magnetic composite nanoparticle of Au/?-Fe2O3 was synthesized in an aqueous phase using gamma-ray. Connection between gold and ?-Fe2O3 was confirmed by the magnetic separation technique. TEM observation shows that 5-nm gold particles were dispersed on 20-nm ?-Fe2O3 particles. The nanoparticles adsorbed a water-soluble mercaptan, glutathione, and was manipulated by an external magnetic field.   

The metal-nonmetal transition in ionic liquids is reviewed with special emphasis on alkali metal-alkali halide solutions and the ionic alloy Cs-Au. Magnetic measurements, especially nuclear magnetic resonance, are discussed in relation to the nature of localized electronic states at low concentrations of excess metal and electron dynamics in the metal-nonmetal transition region. It is suggested that the stability of non-magnetic species governs the occurrence of a continuous metal-nonmetal transition or, alternatively, liquid-liquid phase separation.

Magnetic polymer resins capable of efficient removal of actinides and heavy metals from contaminated water are disclosed together with methods for making, using, and regenerating them. The resins comprise polyamine-epichlorohydrin resin beads with ferrites attached to the surfaces of the beads. Markedly improved water decontamination is demonstrated using these magnetic polymer resins of the invention in the presence of a magnetic field, as compared with water decontamination methods employing ordinary ion exchange resins or ferrites taken separately.

The magnetic map of Slovakia used in the paper was compiled as part of a project titled Atlas of Geophysical maps and profiles in 2001. The residual magnetic data were analyzed to produce Curie point estimates. To remove distortion of magnetic anomalies caused by the Earth’s magnetic field, reduction to pole transformation was applied to the magnetic anomalies using the magnetization angle of the induced magnetization. Anomalies reduced to the pole tend to be better correlated with tectonic structures. We applied a 3-km upward continuation to the residually compiled magnetic anomalies in order to remove effects of topography. The depth of magnetic dipoles was calculated by an azimuthally averaged power spectrum method for the entire area. Such estimates can be indicative of temperatures in the crust, since magnetic minerals lose their spontaneous magnetization according to Curie temperature of the dominant magnetic minerals in the rocks. The computed Curie point depths in the Slovakia region vary between 15.2 km and 20.9 km. Heat flow higher than 100 mWm-2 occurs at the central volcanics and eastern part of Slovakia, where the Curie point depths values are shallow. The correlation between Curie point depths, heat flow and crust depth was investigated for two E-W cross sections. Heat flow and Curie point depth values are correlated with each other however, these values could not be correlated with crust depth. The Curie point isotherm, which separates magnetic and non-magnetic parts of the crust, is represented in two cross sections.

Results of recent polarization transfer experiments indicate that the ratio of the proton's electric to magnetic form factor decreases with increasing momentum transfer, yet the polarization transfer results are in sharp disagreement with the many Rosenbluth separation results. In this paper, it will be shown that the inclusion of a Coulomb correction to the Rosenbluth separation data slightly reduces this discrepancy.

A study is made of the processes responsible for the spatial separation by mass in a weakly ionized plasma in a radial electric field crossed with a longitudinal magnetic field. The separation processes associated with cataphoresis and with transfer of radial momentum from ions to the neutral particles are studied for the case of unmagnetized ions.

Is at present being thoroughly modified and improved, in order to allow for the increased proton beam intensities, resulting from the SC improvement programme. This photograph, taken before the dismantinling of the facility in June 1973, shows the separator analysing magnet (centre background), the collector chamber of the mass-separated ion.

A new mode of magnetophoresis is described that is capable of separating micron-sized superparamagnetic beads from complex mixtures with high sensitivity to their size and magnetic moment. This separation technique employs a translating periodic potential energy landscape to transport magnetic beads horizontally across a substrate. The potential energy landscape is created by superimposing an external, rotating magnetic field on top of the local fixed magnetic field distribution near a periodic arrangement of micro-magnets. At low driving frequencies of the external field rotation, the beads become locked into the potential energy landscape and move at the same velocity as the traveling magnetic field wave. At frequencies above a critical threshold, defined by the bead's hydrodynamic drag and magnetic moment, the motion of a specific population of magnetic beads becomes uncoupled from the potential energy landscape and its magnetophoretic mobility is dramatically reduced. By exploiting this frequency dependence, highly efficient separation of magnetic beads has been achieved, based on fractional differences in bead diameter and/or their specific attachment to two microorganisms, i.e., B. globigii and S. cerevisiae. PMID:18030387

Short lived $^{212,213,214}$Ra isotopes have been produced at the TRI$\\mu$P facility in inverse kinematics via the fusion-evaporation reaction $^{206}$Pb+$^{12}$C at 8 MeV/u. Isotopes are separated from other reaction products online using the TRI$\\mu$P magnetic separator. The energetic radium (Ra) isotopes at the exit of the separator were converted into low energy ions with a thermal ionizer. Ra isotopes have been identified by observing their $\\alpha$ decay and life times.

Monitoring pollutants in water samples is a challenge to analysts. In recent years, separation technology based on magnetic materials has received considerable attention. This article reviews the literature dealing with the application of magnetic materials, combined with other materials (e.g., silica, octadecylsilane, polymers and surfactants), to the separation and the preconcentration of pollutants in water samples. The magnetic extraction method is not only convenient, economical and highly efficient, but it also overcomes problems with conventional solid-phase extraction, (e.g., packing of sorbent into the column and time-consuming loading of large-volume samples).

This paper presents a microfluidic device for magnetophoretic separation red blood cells from blood under contionous flow. The separation method consist of continous flow of a blood sample (diluted in PBS) through a microfluidic channel which presents on the bottom "dots" of feromagnetic layer. By appling a magnetic field perpendicular on the flowing direction, the feromagnetic "dots" generates a gradient of magnetic field which amplifies the magnetic force. As a result, the red blood cells are captured on the bottom of the microfluidic channel while the rest of the blood is collected at the outlet. Experimental results show that an average of 95 % of red blood cells are trapped in the device

Background. The present work illustrates how magnetic separation-based blood purification using ultra-strong iron nanomagnets can be implemented into an extracorporeal blood purification circuit. By this promising technique, today's blood purification may be extended to specifically filter high-molecular compounds without being limited by filter cut-offs or column surface saturation. Methods. Blood spiked with digoxin (small molecule drug) and interleukin-1b (inflammatory protein) was circulated ex vivo through a device composed of approved blood transfusion lines. Target-specific nanomagnets were continuously injected and subsequently recovered with the aid of a magnetic separator before recirculating the blood. Results. Magnetic blood purification was successfully carried out under flow ...

Precise control of the quadrupole and sextupole components of the magnetic fields in focusing and defocusing sectors respectively was achieved by the combined use of pole-face and yoke windings with three separate power supplies synchronously programmed by a computer. Experience of this technique led to a new philosophy in the design of pole-face windings, in which they become an integral and active part of the magnet. With the arrangement described, focusing and guiding functions are partially separated and an old combined-function accelerator can be transformed effectively into a more flexible separate-function machine without any decrease in available straight- section space. (5 refs).

High gradient magnetic field separation (HGMS) has been used to separate several types of > 1 ..mu..m sized ferro- or paramagnetic particles from bulk streams. The majority of the studies have been carried out using a single ferromagnetic wire or wire mesh to produce the field gradients necessary for particle capture. The purpose of this paper is to examine the possibility of using HGMS on < 1 ..mu..m entities for the purpose of macromolecular separations. Preliminary experimental results demonstrate that HGMS techniques can be used to capture 0.1 ..mu..m diam latex beads from a paramagnetic salt solution passing through a columnar bed of ferro- magnetic spheres. 10 refs., 3 figs.

The results ofthe study ofthe uniaxially oriented PDLC films prepared by solvent induced phase separation (SIPS) method are presented. The samples were obtained applying a longitudinal magnetic field while the phase separation of the liquid crystal and polymer occurs due to the evaporation of common solvent from the uniform solution. In the presence of magnetic field the nematic liquid crystals 4-n-pentyl-4' -cyanophenylcyclohexane (5PCH), the 4-n-pentyl-4'- cyanobiphenyl (SCB) and nematic mixture LN-394 form the separate droplets in polyvinylbutyral (PVB) matrix. At that, the nematics 5PCH and LN-394 form always the stable bipolar structures with the order parameter of the droplet axes depending on the value of the applied field. In 5CB droplets the bipolar structure is realized only in a weak magnetic field and the radial one is formed in a strong magnetic field. At intermediate field the non-equilibrium structures are appeared that are characterized by the flickering textures.

Wet magnetic separation tests have been performed on two coals (Eastern Associated Delmont coal and Old Ben coal) using a superconducting magnet. Pyritic sulfur reductions in excess of 86% were achieved for both coals with corresponding yields of 60% by weight of clean coal product. Ash reductions in the range from 60 to 80% were also obtained. These results were obtained with flow velocities ranging from 1 to 4 cm/sec, slurry concentrations between 10 and 33% and magnetic field strengths of 20 and 50 kilogauss with a stainless steel wool matrix for generating high gradients. A conceptual design for a 110 ton/h superconducting magnetic separator is presented. Capital cost for the equipment for this separator is estimated to be $600,000.

Purification techniques are expected to be developed in order to remove a huge amount of water-bloom at high speed, which is a kind of plankton generated in summer due to the eutrophication of lakes and marshes. This paper describes a newly developed water-bloom removal system by means of a magnetic separation technique utilizing superconductivity. Magnetic powders and flocculants are mixed and agitated in the raw water for several minutes, to form floc. Since the magnetic powders are mixed in the floc, the floc is sucked and separated at the magnetic filter by injecting this pre-treated water into the magnetic separator. Thus, purified water is drained. The trial system is wholly cooled through the conduction by cooling an edge of superconductive magnet with the very low temperature gas of a small helium refrigerator. The intensity of magnetic field is 1 tesla, and the demand is 7 kW. Purification tests were conducted using water-bloom raw water of the Kasumigaura, collected in summer, 1995. As a result, it was confirmed that 95% of the water-bloom can be separated and removed at a high speed. This system has a small size and can be mounted on a vehicle. 2 refs., 4 figs., 2 tabs.

One reason that heavy media cyclone (HMC) circuits suffer from the inadvertent loss of magnetite and fine coal is the presence of nonmagnetic material in the magnetic separator feed. In this study, flotation was applied to the undersize fractions of the HMC drain-and-rinse screens to minimize these problems. These fractions, which contain 17.9% nonmagnetic material, are currently sent to magnetic separators and the nonmagnetic portion from the separators contains 39.1% ash. Applying flotation resulted in a clean coal product with an ash content of 8.7% and a calorific value of 6,300 kcal/kg. The refuse from flotation, which will be sent to the magnetic separators, contains 7.7% nonmagnetics.

Techniques of the magnetic force control have been examined for industrial application. The problems and the technique are different in dispersion medium of gas and that of liquid. In addition, the method is different depending on the magnetic characteristic of the target objects. In case of the liquid, the dispersion medium having different viscosity was examined. The separation speed is decided with the magnitude of the magnetic force because a drag force increases with the viscosity. When the water is the dispersion medium, magnetic seeding is possible and hence the nonmagnetic materials can be separated and even the dissolved material could be separated. The separation technique has been used for purifying the waste water form paper mill or wash water of drum. On the other hand when the water is not dispersion medium, mainly the ferromagnetism particle becomes the target object because the magnetic seeding becomes difficult. The iron fragments have been separated from the slurry of slicing machine of solar battery. It has been clarified high gradient magnetic separation (HGMS) can be applied for the viscous fluid of which viscosity was as high as 10 Pa s. When the dispersion medium is gaseous material, the air is important. The drag force from air depends greatly on Reynolds number. When speed of the air is small, the Reynolds number is small, and the drag force is calculated by the Stokes’ law of resistance. The study with gaseous dispersion medium is not carried out much. The magnetic separation will discuss the possibility of the industrial application of this technique.

Thermal power station is made up of a steam turbine and a steam condenser which need a lot of water. The water of steam condenser should be replaced, since scales consisting of iron oxide mainly are accumulated on the surface of condenser pipes as it goes. Superconducting high gradient magnetic separation (HGMS) system has merits to remove paramagnetic substance like iron oxides because it can generate higher magnetic field strength than electromagnet or permanent magnet. In this paper, cryo-cooled Nb-Ti superconducting magnet that can generate up to 6T was used for HGMS systems. Magnetic filters were designed by the analysis of magnetic field distribution at superconducting magnets. The result of X-ray analysis showed contaminants were mostly a-Fe2O3 (hematite) and g-Fe2O3 (maghemite). Th...

We characterize the magnetic behavior of an array of magnetic bead traps based on domain walls (DWs) formed in zig-zag permalloy wires patterned on a Si substrate. Using magnetic force and magneto-optical Kerr effect microscopy, we study the nucleation and annihilation of DWs for two different wire widths. Through scanning electron microscopy with polarization analysis, we analyze in detail the magnetization configuration of the DWs in the presence of a magnetic bead previously trapped by the DW stray field. Finally, we patterned the magnetic nanostructures directly on a polydimethylsiloxane (PDMS) substrate, and we show that the functionality of the device is completely maintained. These results pave the way to the integration of DW-based devices in a PDMS lab-on-a-chip system for magnetic bead separation.

Experiments were conducted to demonstrate the feasibility of recovering oil from fine, stable oil-in- water emulsions by magnetic means. Emulsions in which the oil phase was rendered magnetically responsive by the addition of a ferrofluid were passed through packed beds (containing magnetic particles and/or screens) placed in a magnetic field. The oil content of the effluent stream was typically 2 to 3 orders of magnitude lower than the oil content of the feed emulsion. The influence of various operating parameters including bed height, flow rate, oil magnetization, and magnetic field strength were systematically evaluated. The results demonstrated that it is possible to attain virtually complete removal of particles of the order of one micron in diameter with a static separation device (magnetic demulsifier) using residence times of the order of a fraction of a minute.

We study magnetization reversal processes of in-plane magnetized (Ga,Mn)As epilayers with different hole concentrations in out-of-plane magnetic fields using magnetotransport measurements. A clear difference in the magnetization process is found in two separate samples with hole concentrations of 10^20 cm^-3 and 10^21 cm^-3 as the magnetization rotates from the out-of-plane saturation to the in-plane remanence. Magnetization switching process from the in-plane remanence to the out-of-plane direction, on the other hand, shows no hole concentration dependence, where the switching process occurs via domain wall propagation. We show that the balance of cubic magnetocrystalline anisotropy and uniaxial [110] anisotropy gives an understanding of the difference in the out-of-plane magnetization processes of (Ga,Mn)As epilayers.

This invention provides a photo-electric conversion system which is able to supply the energy to the system such as micromachine requiring the electric energy without employing any electric wire. The system consists of magnetic core member and coil of primary coil side of thin film laminate transformer composing of photo-electric conversion system made on separate substrates, and magnetic core member and coil of secondary coil side. Both magnetic core members face to each other closely to construct the common magnetic core in which the magnetic fluxes are chain-crossed. By combining magnetically the first coil and the second coil through the above-said magnetic coil, the integrated circuit driven by the output of the thin film laminate transformer and driving member such as actuator or sensor can be constructed. As a result, a compact and multi-functional micromachine can be realized. 5 figs.

The fundamental chemistry for selective adsorption of magnetizing reagent on coal-associated minerals to enhance the magnetic susceptibilities of minerals have been established in Phase I study. The application of the results on coal cleaning is in progress in the Phase II study. Illinois No. 6, Ohio Lower Kittanning, and West Virginia Pocahontas coals have been prepared(simulating the industrial operations) and characterized. The adsorption conditions for {minus}48 mesh ROM coals and flotation concentrates have been optimized. Magnetic separation of the reagent conditioned coals shows that both ash and pyritic sulfur can be significantly reduced. Comparing with the repeated flotation approach for coal cleaning, the magnetizing reagent enhanced magnetic separation method shows better performance on cleaning the flotation concentration at {minus}48 mesh.

We demonstrate one-dimensional nuclear magnetic resonance imaging of the semiconductor GaAs with 170 nanometer slice separation and resolve two regions of reduced nuclear spin polarization density separated by only 500 nanometers. This is achieved by force detection of the magnetic resonance, Magnetic Resonance Force Microscopy (MRFM), in combination with optical pumping to increase the nuclear spin polarization. Optical pumping of the GaAs creates spin polarization up to 12 times larger than the thermal nuclear spin polarization at 5 K and 4 T. The experiment is sensitive to sample volumes containing $\\sim 4 \\times 10^{11}$ $^{71}$Ga$/\\sqrt{Hz}$. These results demonstrate the ability of force-detected magnetic resonance to apply magnetic resonance imaging to semiconductor devices and other nanostructures.

We present UVES/VLT observations of the nearby flare star CN Leo covering the Wing-Ford FeH band near 1mu with high spectral resolution. Some of the FeH absorption lines in this band are magnetically sensitive and allow a measurement of the mean magnetic flux on CN Leo. Our observations, covering three nights separated by 48 hours each, allow a clear detection of a mean magnetic field of Bf~2.2kG. The differential flux measurements show a night-to-night variability with extremely high significance. Finally, our data strongly suggest magnetic flux variability on time scales as low as 6 hours in line with chromospheric variability.

The effect of the random magnetic field distribution on the phase diagrams and ground state magnetizations of Ising nanowire is investigated using effective field theory with correlations. Trimodal distribution has been chosen as a random magnetic field distribution. The variation of the phase diagrams with that distribution parameters has been obtained and some interesting results have been found such as reentrant behavior and first order transitions. Also for the trimodal distribution, ground state magnetizations for different distribution parameters have been determined which can be regarded as separate partially ordered phases of the system.

Since May 2011, long-period magnetotelluric (MT) data have been collected in the non-magnetic pavilion at the geophysical base of Moscow University in the Kaluga Region. The non-magnetic pavilion was constructed in compliance with the following conditions: selection of non-magnetic materials, control of local magnetic field anomalies, and setting the basement for magnetometers separately from the main building. Recording equipment with fluxgate and optomechanical magnetometers with three sets of electric lines with different electrodes was installed. The parallel testing of channels was performed. Currently, the seismo-logical equipment and meteorological station are being prepared for installation.

We report on time-resolved coherent x-ray scattering experiments of laser induced magnetization dynamics in Co/Pd multilayers with a high repetition rate optical pump x-ray probe setup. Starting from a multi-domain ground state, the magnetization is uniformly reduced after excitation by an intense 50 fs laser pulse. Using the normalized time correlation, we study the magnetization recovery on a picosecond timescale. The dynamic scattering intensity is separated into an elastic portion at length scales above 65 nm which retains memory of the initial domain magnetization, and a fluctuating portion at smaller length scales corresponding to domain boundary motion during recovery.

On the basis of the model of a flow-type magnetic filter with a transversely magnetized ordered system of long ferromagnetic rods of rectangular cross section, the process of high-gradient magnetic separation of microscopic diamagnetic particles (potato starch granules of sizes 8?30 ?m) from a liquid suspension has been investigated. The registered laws of change in the concentration and size distribution of particles at the suspension outlet from the filter agree with the theoretical conclusions obtained from the analysis of the magnetic field structure and thecharacter of the particle motion in the filter volume.

It is shown that ions can be accelerated by the space charge electric force arising from the separation of electrons and positrons due to the ponderomotive force of the magnetic field-aligned circularly polarized electromagnetic (CPEM) wave in a magnetized electron-positron-ion plasma. The ion acceleration critically depends on the external magnetic field strength. The result is useful in understanding differential ion acceleration in magnetized electron-positron-ion plasmas, such as those in magnetars and in some laboratory experiments that aim to mimic astrophysical environments.

Mechanism of structure formation in bidispersed colloids is important for its physical and optical properties. It is microscopically observed that the mechanism of chain formation in magnetic nanofluid based magnetorheological (MR) fluid is quite different from that in the conventional MR fluid. Under the application of magnetic field the magnetic nanoparticles are filled inside the structural microcavities formed due to the association of large magnetic particles, and some of the magnetic nanoparticles are attached at the end of the chains formed by the large particles. The dipolar energy of the large particles in a magnetic nanofluid matrix becomes effective magnetic permeability ({mu}{sub eff}) times smaller than that of the neutral medium. Inclusion of magnetic nanoparticles ({approx}10 nm) with large magnetic particles ({approx}3-5 {mu}m) restricts the aggregation of large particles, which causes the field induced phase separation in MR fluids. Hence, nanofluid based MR fluids are more stable than conventional MR fluids, which subsequently increase their application potentiality. - Research highlights: In bidispersed magnetic colloids nanoparticles are attached at the end of the chains formed by the large particles. Inclusion of magnetic nanoparticles ({approx}10 nm) with large magnetic particles ({approx}3-5 m) restricts the aggregation of large particles. Nanofluid based MR fluids are more stable than conventional MR fluids.

...of section 1605 of the American Recovery and Reinvestment Act of 2009 (Recovery Act), Public Law 111-5, 123 Stat. 115, 303 (2009), with respect to the purchase of the propulsion shaft bulkhead seals that will be used in the Alaska Region...

...to the City for the purchase and use of four rotary screw air compressors to provide...This action permits the purchase of rotary screw air compressors for Palmer's...Public Law 111-5 for the purchase and use of four rotary screw air compressors...

1 The effects of chemical irritants on the membrane potential and input resistance of the giant amoeba, Chaos carolinense, have been investigated. The membrane potential and input resistance were -111.5 mV and 8.6 M pi respectively. 2 In the resting state the cell membrane of Chaos carolinense was f...

Experimental work using a wet drum magnetic separator has shown this piece of equipment to be extremely robust. Magnetic separators tend to be overlooked by both maintenance and metallurgical personnel. They appear to work with no attention other than the occasional shot of grease. In surveys conducted it was commonly observed that the separator physical settings were not as they should have been. Poor performance of wet drum magnetic separators commonly observed in industrial situations is usually due to their being operated well outside their design envelope. This paper briefly describes the pilot plant experimental programme and considers the reasons for the considerably inferior results obtained in the real world. The findings have clearly shown that a device to continually monitor magnetite losses in magnetic separator tailings, either installed permanently as part of the plant instrumentation, or temporarily as a trouble shooting device, would be of considerable value to producers and have motivated the development of the Magnetics Loss Monitor (MLM). The operation of this monitor and the first field trials are also described. (author). 17 figs., 10 refs.

A proof-of-principle experiment of a novel harmonics separation optics for synchrotron facilities is presented. The harmonic separator is a Si crystal cut in an inclined geometry in which the impinging beam undergoes a diffractive-refractive effect owing to the dispersive nature of X-ray refraction. A polychromatic beam containing higher-order energies is spatially separated behind the separator into individual monochromatic diffraction spots. A synchrotron experiment at a bending-magnet beamline with 7?keV fundamental energy is presented. The spot of the third-order harmonic of 21?keV is deviated from the fundamental by 0.35?mm at a distance 1?m behind the device. PMID:23093763

A method for disintegrating waste office paper using kerosene was reported in our previous paper, which achieved almost a 100% liberation of toner from paper fibers. The liberated toner must be completely separated to realize effective deinking. Recently, a new method for deinking waste officer paper by magnetic separation after hetero-coagulation of magnetic and non-magnetic toner by 1-octadecanol was reported by Augusta et al. Under this method, coagulation was carried out at 72°C. The 1-octadecanol liquid was then cooled to produce strong solid coagulates. As reported in our previous paper, kerosene has the ability to soften toner, and strong coagulates for magnetic separation may be produced by their adhesion when used as a flocculant. The present study investigated the size of toner particles liberated by the kerosene disintegration method, and compared the bonding strength between the toner particles coagulated by the addition of kerosene as a flocculant to those coagulated with 1-octadecanol. After these investigations, the coagulating and deinking properties of kerosene and 1-octadecanol were compared by rejecting toner coagulates with a neodymium-boron magnet. The results showed that nearly perfect deinking can be achieved with little paper loss, even in ambient temperature, due to the large and strong coagulates produced by this method. When kerosene was used in the disintegration and coagulation stages, the average coagulate size was 1114??m, and a deinking percentage of 98.4% was attained through separation with a neodymium-boron magnet.   

La Palma (Canary Islands) represents a hotspot island with an active rift zone, inferred to have formed during the last 800 ka following southward growth of the former radial-symmetrical stratovolcano Taburiente /1/. The aim of our study is to model the magmatic evolution of the rift system from its early stage (Cumbre Nueva) through the short Bejenado volcano phase which followed the Cumbre Nueva collapse (560-549 ka) to the presently active rift zone (Cumbre Vieja). Clinopyroxene-melt thermobarometry and microthermometry of fluid inclusions were applied to constrain magma pathways and major levels of magma stagnation. CO2- dominated fluid inclusions in olivine and clinopyroxene in Taburiente picrites show density distributions with maxima at 0.7-0.85 g/cm-3. These values correspond to equilibrium pressures of 400-600 MPa, in accordance with other Taburiente data /2/. Inclusion data of a Cumbre Nueva ankaramite give pressure estimates of 200-300 MPa. In comparison, fluid inclusions in Recent Cumbre Vieja rocks yield a pronounced pressure estimate at 200-400 MPa, which overlaps with the Cumbre Nueva data but is shallower than that for Taburiente. Clinopyroxene-melt barometry of phenocryst rims and glassy groundmass yield pressure maxima between 600 and 900 MPa for Taburiente, Bejenado and Cumbre Nueva. This pressure range partly overlaps with that for Cumbre Vieja (maximum between 500 and 800 MPa) but has a tendency to higher pressures. The combined data indicate that two separate magma stagnation levels are distinct for each rift phase: (1) a main fractionation level within the upper mantle which is common to all phases, and (2) intermittent stagnation close to the Moho for the Taburiente volcano and above the Moho for both the Cumbre Nueva and Cumbre Vieja. Observing that the present rift system and the early stages of the rift show different levels of fractionation and magma stagnation and also show compositional differences between the lavas, we suggest that the present rift configuration does not reflect continuous growth of the Taburiente shield during the last 800 ka. We thus propose that Taburiente/Cumbre Nueva and Cumbre Vieja represent two distinct volcanoes with separate magma plumbing systems. This model is supported by the overall morphology. /1/ Carracedo et al. (1999), Geol Soc Am Bull 111 (5), 755-768 /2/ Nikogosian et al., (2002), Chem Geol 183, 169-193

In the Quadrupole Magnetic Sorter (QMS) magnetic particles enter a vertical flow annulus and are separated from non-magnetic particles by radial deflection into an outer annulus where the purified magnetic particles are collected via a flow splitter. The purity of magnetically isolated particles in QMS is affected by the migration of nonmagnetic particles across transport lamina in the annular flow channel. Computational Fluid Dynamics (CFD) simulations were used to predict the flow patterns, pressure drop and nonspecific crossover in QMS flow channel for the isolation of pancreatic islets of Langerhans. Simulation results were compared with the experimental results to validate the CFD model. Results of the simulations were used to show that one design gives up to 10% less nonspecific crossover than another and this model can be used to optimise the flow channel design to achieve maximum purity of magnetic particles. PMID:21984840

The progress achieved during this quarter includes the reagent shelf life study, the evaluation and selection of magnetizing reagents, an experimental database for activating and depressing the adsorption of magnetizing reagents in the presence of various chemicals, an adsorption regulator investigation, the establishment of a coal surface controlling theory, and a magnetite size effect study for the separation of magnetic enhanced minerals. The work is on schedule with the original plan. Modifications include the addition of a regulator study to help proving the selectivity controlling theory. The fundamentals for applying the magnetizing reagent technology on coal cleaning are generally established during this quarter. Selective magnetic enhancement of minerals through the adsorption of magnetizing reagents has been experimentally proved. The work for the next quarter will be mainly on optimizing the selective adsorption conditions and the continuation on magnetite size effect study.

This paper deals with designing a telemanipulation system (TMS) for microrobotics applications. The TMS uses magnetic levitation technology for the three-dimensional (3-D) manipulation of a microrobot. The TMS is made up of two separate components: a magnetic drive unit and a microrobot. The magnetic drive unit is developed to generate the magnetic field for propelling the microrobot in an enclosed environment. The drive unit consists of electromagnets, a disc pole-piece for connecting the magnetic poles, and a yoke. To handle the 3-D high precision motion control of the microrobot, experimental magnetic field measurements coupled with numerical analysis were done to identify the dynamic model of levitation. This approach leads to the design of a linear quadratic gaussian (LQG) control sys...

A novel method for the extraction of low concentration heavy metal ions from aqueous solution by using magnetic fluids in the high gradient magnetic separator (HGMS) has been constructed. We dissolved the extractant tributyl phosphate (TBP) in the magnetic fluids, and selected the Au3+ as the model of heavy metal ion to research the extraction efficiency of magnetic fluids containing TBP in this article. The magnetic fluids containing TBP, as stationary phase in the form of liquid-droplet, were immobilized on the surface of steel wires in the HGMS; the low concentration Au3+, as mobile phase, flowed through the HGMS and was extracted from aqueous solution. The experiments investigated the dependence of the Au3+ extraction efficiency of magnetic fluids on the pH value of aqueous solution, T...

We present newly compiled magnetic, gravity, and geologic datasets from the Parkfield region around the San Andreas Fault Observatory at Depth (SAFOD) pilot hole in order to help define the structure and geophysical setting of the San Andreas Fault (SAF). A 2-D cross section of the SAF zone at SAFOD, based on new, tightly spaced magnetic and gravity observations and surface geology, shows that as drilling proceeds NE toward the SAF, it is likely that at least 2 fault bounded magnetic slivers, possibly consisting of magnetic granitic rock, serpentinite, or unusually magnetic sandstone, will be encountered. The upper 2 km of the model is constrained by an order of magnitude increase in magnetic susceptibility at 1400 m depth observed in pilot hole measurements. NE of the SAF, a flat lying, tabular body of serpentinite at 2 km depth separates two masses of Franciscan rock and truncates against the SAF.

The polarization and diffraction characteristics of x-rays incident upon a magnetic material are manipulated to provide a desired magnetic sensitivity in the material. The contrast in diffracted intensity of opposite helicities of circularly polarized x-rays is measured to permit separation of magnetic signals by element type and by atomic environment. This allows for the direct probing of magnetic signals from elements of the same species in nonequivalent atomic environments to better understand the behavior and characteristics of permanent magnetic materials. By using known crystallographic information together with manipulation of the polarization of x-rays having energies tuned near element-specific electronic excitations and by detecting and comparing the incident and diffracted photons at the same frequency, more accurate magnetic measurements can be made over shorter observation periods.

The relativistic wind of obliquely-rotating pulsars consists of toroidal stripes of opposite magnetic field polarity, separated by current sheets of hot plasma. By means of two- and three-dimensional particle-in-cell simulations, we investigate particle acceleration and magnetic field dissipation at the termination shock of a relativistic striped wind. At the shock, the flow compresses and the alternating fields annihilate by driven magnetic reconnection. Irrespective of the stripe wavelength "lambda" or the wind magnetization "sigma" (in the regime sigma>>1 of magnetically-dominated flows), shock-driven reconnection transfers all the magnetic energy of alternating fields to the particles, whose average Lorentz factor increases by a factor of sigma with respect to the pre-shock value. The shape of the post-shock spectrum depends primarily on the ratio lambda/(r_L*sigma), where r_L is the relativistic Larmor radius in the wind. The spectrum becomes broader as the value of lambda/(r_L*sigma) increases, passing ...

A propulsion and stabilization system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes dividing the superconducting magnets into two types: a strong field magnet which is located vertically below the vehicle for propulsion and guidance and a weak field superconducting magnet located at the ends of the vehicle for levitation and added guidance. Several proposed embodiments exist for the placement of the magnetic field shielding: locating the shielding on the vehicle, locating the shielding on the guideway, and locating the shielding on the guideway and adding shielding to the vertical undercarriage. In addition, the separation between the vehicle and the guideway can be controlled to reduce the exposure of the passenger cabin to magnetic fields.

Nickel metal hydride batteries of hybrid vehicles contain rare metals such as Ni, Co, and rare-earth elements as electrode components. A direct smelting method has been used to recover Ni from waste batteries, but the Co and rare-earth elements are difficult to extract with this conventional method. To recycle Co and rare-earth elements, physical pretreatment is necessary to separate the anode and cathode compounds before smelting. This study investigated the magnetic separation of anode and cathode activating agents in the <0.075mm fraction of crushed cylindrical and prismatic types batteries. In the cylindrical type anode activating agent concentrated in the non-magnetic product of the Davis tube tester, separated at low magnetic fields (0.1T), while in the prismatic type anode activatin...

In magnetocaloric La(Fe,Si)13 alloys, it is known that hydrogen addition shifts the magnetic transition temperature TC near room temperature. By partial hydrogen desorption, TC can be adjusted precisely towards the working temperature of a magnetic cooling device. In this work, we studied the stability of partially desorbed LaFe11.6Si1.4Hy and show that the large volume difference of ferro- and para-magnetic phases drives the system from a single phase to a stable two-phase configuration. The hydrogen concentration separates on a macroscopic scale. The phase-coexistence is visualized by Kerr Microscopy. Differential scanning calorimetry measurements show that hydrogen can be reversibly recombined and separated again. We explain the separation by the coexistence of a high-volume ferromagnetic and low-volume paramagnetic phase that can be induced either by temperature or other external stimuli. This phenomenon can be applied to material systems that show a coupling of physical and structural transitions.

Reverse flotation studies on magnetite samples have revealed that the use of starch as a depressant of Fe-oxides has a hydrophilic effect on the surface of Fe-bearing silicates and significantly decreases Fe in the silica-rich stream when used in combination with an amine (Lilaflot D817M). In this study, the effect of reverse flotation on the optimization of products obtained from magnetic separation was investigated. Two different magnetic samples, zones 1 and 2, were milled to separation (LIMS). The LIMS test conducted on the separation. Reverse flotation tests were conducted on the agitated magnetic concentrate feed, and the result shows a significant upgrade of Fe compared to that obtained from the non-agitated feed. Iron concentrations greater than 69%, and SiO2 concentrations less than 2% with overall magnetite recoveries greater than 67% and 71% were obtained for zones 1 and 2, respectively.

The demonstration of quantized spin splitting by Stern and Gerlach is one of the most important experiments in modern physics. Their discovery was the precursor of recent developments in spin-based technologies. Although electrical spin separation of charged particles is fundamental in spintronics, in non-uniform magnetic fields it has been difficult to separate the spin states of charged particles due to the Lorentz force, as well as to the insufficient and uncontrollable field gradients. Here we demonstrate electronic spin separation in a semiconductor nanostructure. To avoid the Lorentz force, which is inevitably induced when an external magnetic field is applied, we utilized the effective non-uniform magnetic field which originates from the Rashba spin-orbit interaction in an InGaAs-based heterostructure. Using a Stern-Gerlach-inspired mechanism, together with a quantum point contact, we obtained field gradients of 108 T m-1 resulting in a highly polarized spin current.

The mass spectrometer NASE (NAchSEparator) built as a post-separator and located behind the velocity filter SHIP at the GSI in Darmstadt, was taken into operation as a gas-filled separator, and its separation properties for fusion products from heavy ion reactions were studied. Chapter 2 describes the principle of separation in a gas-filled magnet. The technical specifications of the separator, the detectors and the setup of detection electronics are outlined in chapter 3. The studies of separation properties are described in chapter 4, and chapter 5 deals with preliminary applications of the gas-filled separator to detect isotopes poor in neutrons, with an atomic number Z = 92, 93. Chapter 6 is concerned with preliminary tests to detect heavy nuclei with an atomic number Z > = 100 by means of light radiation and actinide targets. The experimental results of comparative measurements between the velocity filter SHIP and the gas-filled separator are pointed out in chapter 7, and future application possibilities of gas-filled separators for synthesis of heaviest nuclei through asymmetric reactions are discussed. (orig./BBR). [Deutsch] Das als NAchSEparator gebaute Massenspektrometer NASE, das sich hinter dem Geschwindigkeitsfilter SHIP bei der GSI in Darmstadt befindet, wurde als gasgefuellter Separator in Betrieb genommen und seine Separationseigenschaften fuer Fusionsprodukte aus Schwerionenreaktionen wurden untersucht. In Kapitel 2 wird das Prinzip der Trennung in einem gasgefuellten Magneten beschrieben. Die technischen Spezifikationen des Separators, die Detektoren und der Aufbau der Nachweiselektronik werden in Kapitel 3 skizziert. Die Untersuchungen der Separationseigenschaften werden im Kapitel 4 beschrieben und im Kapitel 5 erste Anwendungen des gasgefuellten Separators zum Nachweis neutronenarmer Isotope mit einer Ordnungszahl Z = 92, 93. Kapitel 6 befasst sich mit den ersten Versuchen schwere Kerne mit einer Ordnungszahl Z > = 100 mit leichten Strahlen und Aktinidentargets nachzuweisen. Die experimentellen Ergebnisse der Vergleichsmessungen zwischen dem Geschwindigkeitsfilter SHIP und dem gasgefuellten Separator werden im Kapitel 7 aufgezeigt sowie zukuenftige Einsatzmoeglichkeiten des gasgefuellten Separators zur Synthese schwerster Kerne ueber asymmetrische Reaktionen diskutiert. (orig./BBR).

Here, we present a novel technique to immobilize magnetic particles onto whole Gluconobacter oxydans in situ via a synthetic adhesive biomimetic material inspired by the protein glues of marine mussels. Our approach involves simple coating of a cell adherent polydopamine film onto magnetic nanoparticles, followed by conjugation of the polydopamine-coated nanoparticles to G. oxydans which resulted in cell aggregation. After optimization, 21.3?mg (wet cell weight) G. oxydans per milligram of nanoparticle was aggregated and separated with a magnet. Importantly, the G. oxydan aggregates showed high specific activity and good reusability. The facile approach offers the potential advantages of low cost, easy cell separation, low diffusion resistance, and high efficiency. Furthermore, the approach is a convenient platform technique for magnetization of cells in situ by direct mixing of nanoparticles with a cell suspension. Biotechnol. Bioeng. 2012; 109: 2970-2977. © 2012 Wiley Periodicals, Inc. PMID:22729662

Nanoscale magnetite (Fe3O4) (<15 nm) is known to remove arsenic efficiently but is very difficult to separate or require high magnetic fields to separate out from the waste water after treatment. Anisotropic hexagonal ferrite (BaFe12O19, BHF) is a well-known permanent magnet (i.e., fridge magnets) and attractive due to its low cost in making large quantities. BHF offers a viable alternative to magnetite nanocrystals for arsenic removal since it features surfaces similar to iron oxides but with much enhanced magnetism. Herein, we employ BHF nanocrystalline materials for the first time in arsenic removal from wastewater. Our results show better (75 %) arsenic removal than magnetite of the similar sizes. The BHF nanoparticles, 6.06 ± 0.52 nm synthesized by thermolysis method at 320 °C do not ...

Superconducting accelerators and storage rings, presently under construction or in the design phase, are based on separate dipole and quadrupole magnets. It is here suggested that a hybrid lattice configuration consisting of dipoles and combined function gradient magnets would: (1) reduce the number of magnet units and their total cost; and (2) increase the filling factor and thus the energy at a given field. Coil cross sections are presented for the example of the Brookhaven Colliding Beam Accelerator. An asymmetric two-layer cable gradient magnet would have transfer functions of 10.42 G/A and 0.628 G cm/sup -1//A versus 15.77 G/A and 2.03 G cm/sup -1//A of the present separate dipoles and quadrupoles.

Dipole bending magnets are required to change the horizontal separation of the two beams in the LHC. In Intersection Regions (IR) 1, 2, 5, and 8, the beams are brought into collision for the experiments located there. In IR4, the separation of the beams is increased to accommodate the machine's particle acceleration hardware. As part of the US contribution to the LHC Project, BNL is building the required superconducting magnets. Designs have been developed featuring a single aperture cold mass in a single cryostat, two single aperture cold masses in a single cryostat, and a dual aperture cold mass in a single cryostat. All configurations feature the 80 mm diameter, 10 m long superconducting coil design used in the main bending magnets of the Relativistic Heavy Ion Collider recently completed at Brookhaven. The magnets for the LHC, to be built at Brookhaven, are described and results from the program to build two dual aperture prototypes are presented.

The plasma dynamics resulting from the simultaneous impact, of two equal, ultra-intense laser pulses, in two spatially separated spots, onto a dense target is studied via particle-in-cell (PIC) simulations. The simulations show that electrons accelerated to relativistic speeds, cross the target and exit at its rear surface. Most energetic electrons are bound to the rear surface by the ambipolar electric field and expand along it. Their current is closed by a return current in the target, and this current configuration generates strong surface magnetic fields. The two electron sheaths collide at the midplane between the laser impact points. The magnetic repulsion between the counter-streaming electron beams separates them along the surface normal direction, before they can thermalize through other beam instabilities. This magnetic repulsion is also the driving mechanism for the beam-Weibel (filamentation) instability, which is thought to be responsible for magnetic field growth close to the internal shocks of ...

The charge ordered La1/3Sr2/3FeO3-? (LSFO) in bulk and nanocrystalline forms are investigated using ac and dc magnetization, Mössbauer, and polarized neutron studies. A complex scenario of short-range charge and magnetic ordering is realized from the polarized neutron studies in nanocrystalline specimen. This short-range ordering does not involve any change in spin state and modification in the charge disproportion between Fe3+ and Fe5+ compared to bulk counterpart as evident in the Mössbauer results. The refinement of magnetic diffraction peaks provides magnetic moments of Fe3+ and Fe5+ are about 3.15 ?B and 1.57 ?B for bulk, and 2.7 ?B and 0.53 ?B for nanocrystalline specimen, respectively. The destabilization of charge ordering leads to magnetic phase separation, giving rise to the robust exchange bias (EB) effect. Strikingly, EB field at 5 K attains a value as high as 4.4 kOe for average size ˜70 nm, which is zero for the bulk counterpart. A strong frequency dependence of ac susceptibility reveals cluster-glass-like transition around ˜65 K, below which EB appears. Overall results propose that finite-size effect directs the complex glassy magnetic behavior driven by unconventional short-range charge and magnetic ordering, and magnetic phase separation appears in nanocrystalline LSFO.

This paper summarizes studies on the application of fine powder materials to the biochemical engineering, as for the structural analysis of protein molecules on solid phase surface, and the development of functional fine particles and their application to bioproduct separation. The purpose of this series of investigations is to utilize existing fine powder materials by the new ideas, and to newly prepare fine powder materials suitable for the operation. Since ultra fine powder dispersion liquid is transparent and the light is not scattered, the structure of protein on the solid phase surface can be evaluated through the spectroscopic method, such as circular dichroic spectroscopy. By this method, the structural change of protein on the solid phase surface is illustrated. In addition, the magnetic separation method, coagulation separation method, and extraction separation method were investigated as fine powder separation method, and their effectiveness was revealed. Moreover, the affinity separation process of bioproducts using fine powders is introduced. 8 refs., 3 figs.

In order to produce pure beams of radioactive products emanating from the production target/ion source system, both mass and isobar separation is required. A preliminary mass separation with a resolution {triangle}M/M of approximately 10{sup -3} will select the proper mass beam. An isobar separator is needed because the masses of adjacent isobars are usually quite close, especially for beams near stability. In general, a mass resolution of 5 x 10{sup -5} is needed for isobar separation in the A < 120 region, while a resolution of 3 x 10{sup -5} or better is needed for heavier masses. Magnets are used to obtain mass separation. However, in addition to having mass dispersion properties, magnets also have an equal energy dispersion. This means that an energy variation in the beam cannot be distinguished from a mass difference. This is important because ions emerge from the ion source having a small ({approximately} 10{sup -5} - 10{sup -4}) energy spread. In order to make the system respond only to mass differences, it must be made energy dispersion. This is normally accomplished by using a combination of electric and magnetic fields. The most convenient way of doing this is to use an electric deflection following the magnet separator. A preliminary isobar separator which achieves a mass resolution of 2.7 x 10{sup -5} is shown in Figure I-38. It uses two large 60{degrees} bending magnets to obtain a mass dispersion of 140 mm/%, and four electric dipoles with bending angles of 39{degrees} to cancel the energy dispersion. Sextupole and octupole correction elements are used to reduce the geometrical aberrations.

We propose a simple method for separating rare earth elements as oxides from a neodymium magnetic sludge by focusing on the affinity of oxygen for the rare earth elements (Nd, Dy, and Pr) and Fe. We have conducted separation experiments with a carbon crucible as contact material to confirm that carbon maintains the oxygen potential in the coexistence region of rare earth oxides and metallic Fe. In this work, the oxide phase of the rare earth elements and the alloy phase that primarily consists of Fe were separated clearly when the magnetic sludge in the carbon crucible was kept at 1823 K (1550 °C) under an Ar atmosphere. The purity of the rare earth oxide phase was high and only a small amount of rare earth elements were contained in the alloy phase. We found that the melting temperature of the rare earth oxides is a crucial factor for separation efficiency in our proposed method.

In an ore cleaning process, the underflow from an ore classifying cyclone is delivered to a heavy medium cyclone where the ore is cleaned. The underflow leaving the classifying cyclone is continually measured for specific gravity and flow rate while the specific gravity of heavy medium that can be applied to the underflow is continually measured. The amount of this heavy medium and the amount of water required to be added to the underflow are continually controlled as functions of the specific gravity and flow rate thus measured, whereby a substantially constant specific gravity and flow rate of the underflow is maintained as it enters the heavy medium cyclone. Magnetic separating means receive the overflow from the heavy medium cyclone and separate the heavy medium from the ore, while other magnetic separating means receive the underflow from the same cyclone and separate the heavy medium from the rejects. The heavy medium is used again. 3 claims, 1 figure.

The effect of low-magnetic fields on the magnetic and electrical transport properties of polycrystalline samples of the phase-separated compound La0.5Ca0.5MnO3 is studied. The results are interpreted in the framework of the field-induced ferromagnetic fraction enlargement mechanism. A fraction expansion coefficient ?f, which relates the ferromagnetic fraction f with the applied field /H, was obtained. A phenomenological model to understand the enlargement mechanism is worked out.

This bibliography contains citations concerning the curing of urethane and polyurethane coatings by electromagnet radiation. This bibliography is specific to electric and/or magnetic curing as compared to photocuring or ultraviolet curing, which are treated as separate bibliographies. These coatings may be described as inks, paints, lacquers, adhesives, or specialized coatings. Special applications of this technology in the magnetic recording media industry are presented. (Contains 98 citations fully indexed and including a title list.)

The method of waveguide light propagation was applied to carry out direct measurement of non-diagonal components of tensors of dielectric and magnetic permittivity of (YbPr)/sub 3/(FeGa)/sub 5/O/sub 12/ ferrite-garnet. Separate measurement of non-diagonal components of tensors of dielectric and magnetic permittivity can be conducted at waveguide light propagation in ferrite-garnet epitaxial films; the non-diagonal components of the tensor appear to be different from zero in the optical frequency range.

Magnetic field-flow fractionation (MgFFF) is a technique for the separation and characterization of magnetic nanoparticles. It is explained that the analysis of polydisperse samples requires a programmed decay of field and field gradient during sample elution. A procedure for achieving reproducible field decay with asymptotic approach to zero field using a quadrupole electromagnet is described. An example of an analysis of a polydisperse sample under programmed field decay is given.

We find exact solutions of the Dirac equation in the 2+1 dimensional curved background by separation of variables. These solutions are given in terms of hypergeometric functions. We also perform the Gordon decomposition for the Dirac current to discuss the time dependence of the polarization densities and the magnetization density, and to show that the polarization densities are more effective than the magnetization density in the pair production in finite time intervals.

In this paper we study the dynamics of charged particles interacting with a space homogeneous but time oscillating magnetic field of arbitrary amplitude and frequency. We analyze the stability of the particles orbits as functions of the magnetic field parameters and their masses. Based on the fact for a given magnitude field, the particles trajectories may become unstable depending on their masses, that we propose this system as an isotopic separator. (Author)

An asymptotic representation is given of the Gordeyev transcendental function appearing in the elements of the dielectric tensor of a hot nonrelativistic Vlasov plasma in a magnetic field. It is valid for large values of the Larmor radius parameter and for initial-value problems in the finding of the dispersion relation roots. This formula shows, in the limit, a clear separation between magnetic and nonmagnetic effects.

An extensive measurement of the elastic H(e,e?)p reaction in the Q 2-region from 0.003 to 1?(GeV/c)2 has been performed with the three-spectrometer set-up of the A1 collaboration at the Mainz Microtron. The data set consists of about 3,000 overlapping cross-section measurements with a high level of internal redundancy, which allow for a determination of the electric and magnetic form factors with strict control over statistical and systematic errors, in particular also of the charge and magnetization radii of the proton. Besides the classical Rosenbluth separation, the form factors are separated by direct, global fits of different sufficiently flexible models.

High gradient magnetic field separation (HGMS) has been used to separate several types of > 1 ..mu..m sized ferro- or paramagnetic particles from bulk streams. The majority of the studies have been carried out using a single ferromagnetic wire or wire mesh to produce the field gradients necessary for particle capture. The purpose of this paper is to examine the possibility of using HGMS on HGMS techniques can be used to capture 0.1 ..mu..m diam latex beads from a paramagnetic salt solution passing through a columnar bed of ferro- magnetic spheres. 10 refs., 3 figs.

Invert sugar (an equimolar mixture of glucose and fructose prepared by sucrose hydrolysis) is a very important food component. We have prepared magnetically responsive alginate microbeads containing entrapped Saccharomyces cerevisiae cells and magnetite microparticles which can be easily separated in an appropriate magnetic separator. The microbeads (typical diameter between 50 and 100 ?m) were prepared using the water-in-oil emulsification process. The prepared microbeads containing yeast cells with invertase activity enabled efficient sucrose conversion. The biocatalyst was quite stable; the same catalytic activity was observed after one month storage at 4 °C and the microbeads could be used at least six times.

Electron Backscatter Diffraction (EBSD) studies clearly revealed a different crystallographic structure of the smallest particle size fraction of gas-atomized AISI 316L stainless steel powder (<4mm) compared with larger sized fractions of the same powder (<45mm). Despite similar chemical compositions, the predominating structure of the smallest particle size fraction was ferritic (i.e., has ferromagnetic properties) whereas the larger sized particle fractions and massive 316L revealed an expected austenitic and non-magnetic structure. From these findings, it follows that direct magnetic separation can be applied to separate very fine sized particles. These structural differences explain previously observed dissimilarities from corrosion and metal release perspectives.