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Sample records for 111-5 magnetic separator

  1. Calibracin del separador magntico de alta intensidad magnet-lift mlh (13) 111-5 para su uso en el laboratorio de termocronologa de la UCV

    Scientific Electronic Library Online (English)

    A, MAURICIO; CELLA, BERMDEZ; RAQUEL C, ANAYA.

    Full Text Available En este artculo se presenta la calibracin del separador magntico de alta intensidad Magnet-lift MLH (13) 111-5 existente en el Laboratorio de Termocronologa de la Universidad Central de Venezuela con la finalidad de separar magnticamente minerales pertenecientes a areniscas y muestras grantica [...] s para su posterior fechado por el mtodo de huellas de fisin. Los resultados obtenidos de esta calibracin fueron aplicados a una muestra de 10 kilogramos pertenecientes a unaconcentracin inicial de minerales de la Formacin Betijoque del flanco norte de Los Andes Venezolanos. Se concluye que el Magnet-lift presenta amplias ventajas con respecto a los separadores magnticos convencionales y adems optimiza el tiempo de procesamiento de rocas detrticas que posteriormente sern fechadas por el mtodo de datacin empleado eneste laboratorio con el fin de discriminar la edad del ltimo evento tecto-trmico 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 sub [...] jected 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 Betijoques 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.

  2. Magnetic Separation in Czechoslovakia

    OpenAIRE

    Hencl, Vladimir

    1991-01-01

    The use of magnetic separation in various mineral processing facilities in Czechoslovakia is described. The manufacture of assorted types of magnetic separation machines is highlighted. Potential applications and research and development activities are discussed.

  3. Magnetic separation anxiety

    International Nuclear Information System (INIS)

    This paper reports that only a few years ago superconducting magnetic separation was viewed as the next major market for superconducting magnets. The first commercial units had been installed, worked flawlessly, and demonstrated real economic viability. The potential market was seen as quite large, and many people believed that superconducting magnetic separation would soon show the same rapid growth that MRI had demonstrated after its initial success. These hopes even prompted IGC, one of the top MRI magnet builders, to form a separate division devoted to magnetic separation. Despite the existence of Magstream, IGC has not been overly active in the market. As a technology that has applications from the clay on the Earth to the soil on the moon, superconducting magnetic separation has yet to become widely used

  4. Magnetic separation anxiety

    Energy Technology Data Exchange (ETDEWEB)

    Canning, C.

    1992-01-01

    This paper reports that only a few years ago superconducting magnetic separation was viewed as the next major market for superconducting magnets. The first commercial units had been installed, worked flawlessly, and demonstrated real economic viability. The potential market was seen as quite large, and many people believed that superconducting magnetic separation would soon show the same rapid growth that MRI had demonstrated after its initial success. These hopes even prompted IGC, one of the top MRI magnet builders, to form a separate division devoted to magnetic separation. Despite the existence of Magstream, IGC has not been overly active in the market. As a technology that has applications from the clay on the Earth to the soil on the moon, superconducting magnetic separation has yet to become widely used.

  5. High gradient magnetic separation

    International Nuclear Information System (INIS)

    In a process in which magnetic material is trapped in a filter disposed in a magnetic field, and is unloaded by passing a fluid through the filter in the absence of the initial magnetic field, the magnetic field is first reduced to an intermediate value to allow unloading of the more weakly magnetic particles, the more strongly magnetic particles being retained and subsequently unloaded by further reduction of the magnetic field. Stage by stage reduction of the magnetic field during unloading allows separation of different species from the mixture. As an example the method can be applied to the separation of uranium compounds from mine ores. The uranium compounds are magnetic, while most of the other constituents of the ore are non-magnetic. The starting material is a suspension of the ore. Water is used for unloading. The filter material in this case is stainless steel balls. (author)

  6. 25 CFR 111.5 - Future payments.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Future payments. 111.5 Section 111.5 Indians BUREAU OF... 111.5 Future payments. Indians who have received or applied for their pro rata shares of an interest... act of May 18, 1916 (39 Stat. 128), will not be permitted to participate in future payments made...

  7. Magnetic Separation in South Africa

    OpenAIRE

    Corrans, Ian James; Svoboda, Jan

    1985-01-01

    The use of magnetic separators in the various mineral processing facilities in South Africa is described. A large number are used to recover medium in dense medium plants. The manufacture of various types of magnetic separation machines by three local suppliers is highlighted. The potential use of highgradient and/or highintensity magnetic separation in the recovery of gold, uranium, and phosphate minerals is discussed.

  8. Magnetic separation in microfluidic systems

    DEFF Research Database (Denmark)

    Smistrup, Kristian

    2007-01-01

    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...... 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...

  9. Isotope separation by magnetic fields

    International Nuclear Information System (INIS)

    One of the isotopes of an element having several isotopes can be separated from the others in a dense, neutral plasma. Thus initially a neutral plasma is prepared including the element in question. This may consist of positive ions and negative electrons or alternatively of positive and negative ions, or else of a mixture of positive ions, negative ions and electrons. The plasma may then be injected into a magnetic field or may be generated in the field where more energy is imparted to a selected isotope than to the others. Finally, the isotopes are separated from each other on the basis of their differential energies. For example, the selected isotope may be given more energy than the others by stimulating it within the plasma at its resonant frequency which may be close to the cyclotron frequency, either by an electric field or by a magnetic field. In order to excite the other isotope, a different resonant frequency is required which depends on the plasma density, the relative concentration of electrons if the plasma contains electrons, the strength of the magnetic field, the ratio of charge to mass of the isotope, and possibly on the physical parameters of the plasma apparatus itself, such as the ratio of the length of the plasma column to its radius. The more energetic isotope may be separated by energy dependent chemical reactions, it may be collected by a positively biased probe or else the isotopes may be separated from each other by magnetic fields or in various other ways

  10. Recent Activities in Magnetic Separation in Sweden

    OpenAIRE

    Wang, Yanmin; Forssberg, Eric

    1995-01-01

    This paper describes some industrial applications of magnetic separation in Swedish mineral industry. Recent studies on magnetic treatment of minerals in Sweden are also presented. These studies involve selectivity of wet magnetic separation, wet magnetic recovery of mineral fines and ultrafines, sulphide processing by magnetic means, as well as dry magnetic purification of industrial minerals.

  11. Magnetic Enhancement in High Gradient Magnetic Separation.

    Science.gov (United States)

    Kelland, David Ross

    Available from UMI in association with The British Library. Requires signed TDF. An effective way to improve the performance of High Gradient Magnetic Separation (HGMS) is to increase the magnetization of small particulates. An example in which this can be demonstrated is in the use of HGMS to desulfurize coal. Part of the sulfur in coal occurs as finely divided pyrite. Is removal before combustion would reduce SO_2 emission with a subsequent reduction in acid rain. Experiments on direct heating of mineral pyrite achieved enhanced pyrite magnetization in several different atmospheres; this increase in magnetization was measured on a vibrating sample magnetometer. Mossbauer and electron microprobe analysis have identified the converted mineral as ferrimagnetic monoclinic pyrrhotite along with iron oxides and even iron. Selective heating of the pyrite in coal. To save energy by not heating the coal itself, was accomplished by employing high power density microwave irradiation. Thermal reflectance measurements clearly showed that the final temperature reached in the heated pyrite was higher than that in the coal. Then the improvement in HGMS separations of the partially converted pyrite from coals was demonstrated in samples irradiated at a frequency of 2.45 gigahertz and 5.4 kW of power. Pyrite removal was improved as much as 30-40% (at constant heating value recovery) over that with HGMS alone. In addition to this improvement in HGMS performance, the work provides a microscopic insight into the process of magnetic conversion.

  12. Magnetic separation of antibiotics by electrochemical magnetic seeding

    International Nuclear Information System (INIS)

    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.

  13. Magnetic separation of antibiotics by electrochemical magnetic seeding

    Energy Technology Data Exchange (ETDEWEB)

    Ihara, I; Toyoda, K [Department of Agricultural Engineering and Socio Economics, Kobe University, Nada, Kobe 657-8501 (Japan); Beneragama, N; Umetsu, K [Department of Animal Science, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555 (Japan)], E-mail: ihara@port.kobe-u.ac.jp

    2009-03-01

    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.

  14. Magnetic separations: From steel plants to biotechnology

    Energy Technology Data Exchange (ETDEWEB)

    Cafer T. Yavuz; Arjun Prakash; J.T. Mayo; Vicki L. Colvin [Rice University, Houston, TX (United States). Department of Chemistry

    2009-05-15

    Magnetic separations have for decades been essential processes in diverse industries ranging from steel production to coal desulfurization. In such settings magnetic fields are used in continuous flow processes as filters to remove magnetic impurities. High gradient magnetic separation (HGMS) has found even broader use in wastewater treatment and food processing. Batch scale magnetic separations are also relevant in industry, particularly biotechnology where fixed magnetic separators are used to purify complex mixtures for protein isolation, cell separation, drug delivery, and biocatalysis. In this review, we introduce the basic concepts behind magnetic separations and summarize a few examples of its large scale application. HGMS systems and batch systems for magnetic separations have been developed largely in parallel by different communities. However, in this work we compare and contrast each approach so that investigators can approach both key areas. Finally, we discuss how new advances in magnetic materials, particularly on the nanoscale, as well as magnetic filter design offer new opportunities for industries that have challenging separation problems.

  15. Magnetic Separation - A computer simulation study

    OpenAIRE

    Caciagli, A.

    2015-01-01

    Nanotechnology which involves magnetic particles has experienced, in the last decades, an impressive boost and magnetic nanoparticles have become an interesting research area on their own, finding applications in a rather broad range of techniques and devices, from waste-water treatment to new clinical and biomedical applications. Most notably, they occupy a relevant role in the framework of magnetic separation technology. However, due to their minute size, the actual separation of the magnet...

  16. Microfabricated Passive Magnetic Bead separators

    DEFF Research Database (Denmark)

    Hansen, Mikkel Fougt; Lund-Olesen, Torsten; Smistrup, Kristian; Bruus, Henrik

    2006-01-01

    The use and manipulation of functionalized magnetic beads for bioanalysis in lab-on-a-chip systems is receiving growing interest. We have developed microfluidic systems with integrated magnetic structures for the capture and release of magnetic beads. The systems are fabricated in silicon by deep...

  17. Wide aperture multipole magnets of separator COMBAS

    International Nuclear Information System (INIS)

    The high-resolving wide aperture separator COMBAS has been designed and commissioned at the FLNR, JINR. Its magneto-optical structure is based on strong focusing principle. The magnetic fields of analysing magnets M1, M2, M7, M8, contain quadrupole components of alternating sign that provide necessary beam focusing. Besides, all the magnets M1 - M8, contain sextupole and octupole field components, which minimizes the 2nd and 3rd order aberrations. All this allowed one to increase their apertures, to effectively form a beam of the required sizes, and to decrease the channel length. This implementation of wide aperture magnets with combined functions is unique for the separation technology. Three-components magnetic measurements of all the magnets were performed. The measured data allow reconstructing the 3D-distributions of the fields in all the magnets. 3D-maps are supposed to be used for particle trajectory simulations throughout the entire separator

  18. A superconducting magnetic separator with magnetically balanced matrix

    International Nuclear Information System (INIS)

    In a magnetic separator the field gradients around magnetized fibres (the matrix) are used to capture particles. To remove the particles from the fibres the background magnetic field must be reduced to zero. The large superconducting magnets which are used to produce the background field cannot be de-energised quickly (i.e. in less than 1000 s). As the separator is fully loaded in approximately 1000 s a way must be found to reduce the cleaning time significantly

  19. Microfluidic magnetic separator using an array of soft magnetic elements

    DEFF Research Database (Denmark)

    Smistrup, Kristian; Lund-Olesen, Torsten; Hansen, Mikkel Fougt; Tang, Peter Torben

    2006-01-01

    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....

  20. Magnetic separation of uranium from waste materials

    International Nuclear Information System (INIS)

    Criteria were developed for selection of candidate wastes for testing magnetic separation of uranium and/or other paramagnetic materials. A survey of Department of Energy (DOE) hazardous wastes was conducted to determine good candidates for bench-scale magnetic separation tests. Representatives of 21 DOE sites were contacted, and materials were identified as potential candidates for magnetic separation. To date, seven samples have been obtained and tested for separability of uranium with a bench-scale magnetic assaying device. The samples tested have been obtained from the K-1401B and K-1401C ponds in Oak Ridge, Tennessee; from waste piles in Maywood, New Jersey; from North and South Ponds in Richland, Washington; and from magnesium fluoride drums in Fernald, Ohio. The magnetic device utilized in these tests can be used in a deflective mode with dry particulate samples or a matrix-gradient mode with either dry particulate or liquid-suspended materials. Uranium separation from magnesium fluoride has shown exceptionally good performance in both wet and dry systems and could be an important application of the technology. 13 figs., 6 tabs

  1. Development of magnetic separation system of magnetoliposomes

    Science.gov (United States)

    Nakao, R.; Matuo, Y.; Mishima, F.; Taguchi, T.; Maenosono, S.; Nishijima, S.

    2009-10-01

    The magnetic separation technology using sub-microsized ferromagnetic particle is indispensable in many areas of medical biosciences. For example, ferromagnetic particles (200-500 nm) are widely used for cell sorting in stem cell research with the use of cell surface-specific antigens. Nanosized ferromagnetic particles (10-20 nm) have been suggested as more suitable in drug delivery studies given their efficiency of tissue penetration, however, the magnetic separation method for them has not been established. One of the major reasons is that magnetic force acting on the object particles decreases drastically as a particle diameter becomes small. In this study, magnetic force acting on the targets was enhanced by the combination of superconducting magnet and the filter consisting of ferromagnetic particle. By doing so, we confirmed that Fe 3O 4 of 20 nm in diameter was trapped in the magnetic filter under an external magnetic field of 0.5 T. Fe 3O 4 encapsulated with phospholipid liposomes of 200 nm in diameter was also shown to be trapped as external magnetic field of 1.5 T, but not of 0.5 T. We also showed the result of particle trajectory calculation which emulated well the experimental data.

  2. Development of magnetic separation system of magnetoliposomes

    Energy Technology Data Exchange (ETDEWEB)

    Nakao, R., E-mail: ryo-nakao@see.qb.eng.osaka-u.ac.j [Osaka University. Yamadaoka 2-1, Suita, Osaka, 565-0871 (Japan); Matuo, Y.; Mishima, F. [Osaka University. Yamadaoka 2-1, Suita, Osaka, 565-0871 (Japan); Taguchi, T. [Osaka University. Yamadaoka 2-1, Suita, Osaka, 565-0871 (Japan); University of Queensland, 4072, QLD (Australia); Maenosono, S. [Japan Advanced Institute of Science and Technology, Nomi, Ishikawa, 923-1292 (Japan); Nishijima, S. [Osaka University. Yamadaoka 2-1, Suita, Osaka, 565-0871 (Japan)

    2009-10-15

    The magnetic separation technology using sub-microsized ferromagnetic particle is indispensable in many areas of medical biosciences. For example, ferromagnetic particles (200-500 nm) are widely used for cell sorting in stem cell research with the use of cell surface-specific antigens. Nanosized ferromagnetic particles (10-20 nm) have been suggested as more suitable in drug delivery studies given their efficiency of tissue penetration, however, the magnetic separation method for them has not been established. One of the major reasons is that magnetic force acting on the object particles decreases drastically as a particle diameter becomes small. In this study, magnetic force acting on the targets was enhanced by the combination of superconducting magnet and the filter consisting of ferromagnetic particle. By doing so, we confirmed that Fe{sub 3}O{sub 4} of 20 nm in diameter was trapped in the magnetic filter under an external magnetic field of 0.5 T. Fe{sub 3}O{sub 4} encapsulated with phospholipid liposomes of 200 nm in diameter was also shown to be trapped as external magnetic field of 1.5 T, but not of 0.5 T. We also showed the result of particle trajectory calculation which emulated well the experimental data.

  3. Development of magnetic separation system of magnetoliposomes

    International Nuclear Information System (INIS)

    The magnetic separation technology using sub-microsized ferromagnetic particle is indispensable in many areas of medical biosciences. For example, ferromagnetic particles (200-500 nm) are widely used for cell sorting in stem cell research with the use of cell surface-specific antigens. Nanosized ferromagnetic particles (10-20 nm) have been suggested as more suitable in drug delivery studies given their efficiency of tissue penetration, however, the magnetic separation method for them has not been established. One of the major reasons is that magnetic force acting on the object particles decreases drastically as a particle diameter becomes small. In this study, magnetic force acting on the targets was enhanced by the combination of superconducting magnet and the filter consisting of ferromagnetic particle. By doing so, we confirmed that Fe3O4 of 20 nm in diameter was trapped in the magnetic filter under an external magnetic field of 0.5 T. Fe3O4 encapsulated with phospholipid liposomes of 200 nm in diameter was also shown to be trapped as external magnetic field of 1.5 T, but not of 0.5 T. We also showed the result of particle trajectory calculation which emulated well the experimental data.

  4. Electromagnetic Isotope Separator: Magnetic Measurement: Results

    International Nuclear Information System (INIS)

    The electromagnetic isotope separator of the University of Grenoble can produce isotope with a great purity. It has two magnets with non homogeneous field. The magnetic fields have been corrected with shims in order to obtain an accuracy of ±10-4 in the useful region. These shims have been determined experimentally by measurements. The great enrichment factors obtained, prove the quality of this apparatus. (author)

  5. Magnetic separation using high-Tc superconductors

    International Nuclear Information System (INIS)

    Superconductivity has found in magnetic separation one of its major industrial applications second only to magnetic resonance imaging. Low-Tc superconducting coils have been employed in High Gradient magnetic Separators (HGMS) since the late 80s, the saving in power consumption overcoming the high costs of the liquid helium refrigeration system. The discovery in 1986 of the high-Tc materials has opened the possibility of cooling with liquid nitrogen or cryocoolers, which represents a considerable simplification of the cryogenics involved and a reduction of capital and running costs. But the present high-Tc materials are not sufficiently developed to simply replace low-Tc coils in the opened solenoid configuration of the HGMS, due to their low critical currents around 77 K. This thesis investigates the employment of a high-Tc superconducting coil in a magnetic separator with an iron yoke. In this application the low-Tc coil supplies Ampereturns to a magnetic circuit, which provides a low reluctance path for the magnetic flux and delivers a magnetic field in the air-gap much higher than the field seen by the coil. A small prototype of such a separator has been built. The superconducting coil, a Bi2S2Ca2Cu3O8 solenoid, has been provided by Intermagnetics General Corporation. The use of high-Tc coil as opposed to resistive ones, however, results in different design requirements, ultimately dictated by the sensitivity of the high-Tc material to magnetic fields. Finite elements modelling of the system has provided the framework for the quantitative analysis of the magnetic field distributions on the coil windings and the optimisation of the system configuration. The performance of the separator has been tested at 77 K with liquid nitrogen at atmospheric pressure, and at a temperature ? 67 K by pumping liquid nitrogen at a pressure around 100 Torr. The highest field obtained in the air gap at 67 K was of 340 mT. Magnetic separators with an iron circuit have been in operation for many years in mineral industry, and there appear to be an opportunity of building machines with high-Tc coils or retrofitting existing machines with high-Tc coils to run them closer to saturation in a cheap and effective way. (author)

  6. Isotope separation utilizing Zeeman compensated magnetic extraction

    International Nuclear Information System (INIS)

    A method and apparatus are described for creating a plasma of ions of one isotope type and magnetically extracting the ions from the plasma without impairing the ionization selectivity and efficiency. In a particle flow of plural isotope types, radiant energy is applied to selectively excite and ionize ions of at least one isotope type without corresponding ionization of particles of other isotope types. A magnetic field is applied to divert the ions of the one isotope type sufficiently to permit separate collection of those ions without the other particle constituents of the flow. The system of the invention balances the requirements for a high magnetic field to provide sufficient diversion before charge exchange with the requirement for a limited magnetic field to prevent interference with the selective ionization process due to Zeeman broadening of the isotope absorption lines. 25 claims, 8 drawing figures

  7. Magnetic separation using a switchable system of permanent magnets (abstract)

    Science.gov (United States)

    Watson, J. H. P.; Beharrell, P. A.

    1997-04-01

    Permanent magnets have been used in magnetic filtration, particularly in drum separators, thus, obviating the need for solenoids and electrical power. In the area of high gradient magnetic separation, which uses a matrix magnetized by an external field, the use of permanent magnets has been limited, because the field needs to be switched off periodically, due to the loss of filter efficiency owing to the accumulation of captured material, necessitating periodic cleaning. Cleaning requires the field in the matrix to be reduced, which is not possible with a nonswitchable field source. The solution presented here is to employ a novel arrangement of permanent magnets as the field source that permits the flux density in the matrix to be switched between distinct maximum and minimum levels. As a result, optimum capture is carried out with the field at maximum, then cleaning is accomplished by backwashing the filter with the field at minimum. The aim of this work is to develop a viable filtration system utilizing this principle. Early work has centered on a simple configuration of this system with two-dimensional symmetry and has demonstrated that the basic principles are sound. This apparatus has been incorporated into a separator using a ferromagnetic stainless steel wool matrix and its effectiveness demonstrated using paramagnetic wolframite particles. More sophisticated configurations are being developed with axial symmetry and with more powerful magnet materials, the basic outlines being optimized by means of computer-aided-design. It is anticipated that these subsequent models will provide the basis for a large operating volume, self-contained and fully reusable magnetic separation system.

  8. Fundamental study of phosphor separation by controlling magnetic force

    International Nuclear Information System (INIS)

    Highlights: We tried to separate the phosphor using the magnetic Archimedes separation method. In this method, vertical and radial components of the magnetic force were used. We succeeded to separate HP and developed the continuous separation system. The separation system enables successive separation and recovery of HP. -- Abstract: The phosphor wastes consist of phosphors with different emission colors, green (LAP), red (YOX), blue (BAM) and white (HP). It is required to recover and reuse the rare earth phosphors with high market value. In this study, we tried to separate the phosphor using the magnetic separation by HTS bulk magnet utilizing the differences of magnetic susceptibility by the type of phosphors. We succeeded in the successive separation of HP with low market value from YOX and BAM including the rare earth using the magnetic Archimedes method. In this method, vertical and radial components of the magnetic force were used

  9. Fundamental study of phosphor separation by controlling magnetic force

    Energy Technology Data Exchange (ETDEWEB)

    Wada, Kohei, E-mail: kohei@qb.see.eng.osaka-u.ac.jp; Mishima, Fumihito; Akiyama, Yoko, E-mail: yoko-ak@qb.see.eng.osaka-u.ac.jp; Nishijima, Shigehiro

    2013-11-15

    Highlights: We tried to separate the phosphor using the magnetic Archimedes separation method. In this method, vertical and radial components of the magnetic force were used. We succeeded to separate HP and developed the continuous separation system. The separation system enables successive separation and recovery of HP. -- Abstract: The phosphor wastes consist of phosphors with different emission colors, green (LAP), red (YOX), blue (BAM) and white (HP). It is required to recover and reuse the rare earth phosphors with high market value. In this study, we tried to separate the phosphor using the magnetic separation by HTS bulk magnet utilizing the differences of magnetic susceptibility by the type of phosphors. We succeeded in the successive separation of HP with low market value from YOX and BAM including the rare earth using the magnetic Archimedes method. In this method, vertical and radial components of the magnetic force were used.

  10. Optimizing the performance of wet drum magnetic separators

    Scientific Electronic Library Online (English)

    M., Dworzanowski.

    2010-11-01

    Full Text Available The difference in the magnetic properties of minerals is the basis for magnetic separation. All minerals can be generally classified as ferromagnetic (strongly magnetic), paramagnetic (weakly magnetic) or diamagnetic (non-magnetic). Magnetic separation can be conducted dry or wet. The majority of th [...] e applications of wet magnetic separation in the mining industry are based on the wet drum magnetic separator. The wet drum magnetic separator has been in use for over 50 years and its design is based on a rotating drum installed inside a tank. Inside the drum are stationary, permanent magnets arranged in an arc to provide the magnetic field. These magnets can be of the ceramic ferrite type providing a low intensity magnetic field or of the rare earth type providing a high intensity magnetic field. Wet drum magnetic separators are generally applied in three different ways, namely to recover and recycle the medium used in dense medium separation (DMS), to remove magnetic contaminants from ores and concentrates, and to recover valuable magnetic products. Wet drum magnetic separators are applied in the following commodity areas: coal, diamonds, iron ore, chrome, platinum, heavy mineral sands, industrial minerals, and base metals. Whereas the design and operation of wet drum magnetic separators is relatively straightforward, it is very often found that the performance of wet drum magnetic separators is far from optimum. The reason for this is generally a lack of understanding of how the different design and operating variables interact and how they affect performance. This paper examines these variables, describing their importance and impact for all applications of wet drum magnetic separators. It also provides clear guidelines on how to adjust and control these variables so that optimum performance is achieved.

  11. High Radiation Environment Nuclear Fragment Separator Magnet

    Energy Technology Data Exchange (ETDEWEB)

    Kahn, Stephen [Muons, Inc., Batavia, IL (United States); Gupta, Ramesh [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-01-31

    Superconducting coils wound with HTS conductor can be used in magnets located in a high radiation environment. NbTi and Nb3Sn superconductors must operate at 4.5 K or below where removal of heat is less efficient. The HTS conductor can carry significant current at higher temperatures where the Carnot efficiency is significantly more favorable and where the coolant heat capacity is much larger. Using the HTS conductor the magnet can be operated at 40 K. This project examines the use of HTS conductor for the Michigan State University Facility For Rare Isotope Beams (FRIB) fragment separator dipole magnet which bends the beam by 30° and is located in a high radiation region that will not be easily accessible. Two of these magnets are needed to select the chosen isotope. There are a number of technical challenges to be addressed in the design of this magnet. The separator dipole is 2 m long and subtends a large angle. The magnet should keep a constant transverse field profile along its beam reference path. Winding coils with a curved inner segment is difficult as the conductor will tend to unwind during the process. In the Phase I project two approaches to winding the conductor were examined. The first was to wind the coils with curved sections on the inner and outer segments with the inner segment wound with negative curvature. The alternate approach was to use a straight segment on the inner segment to avoid negative curvature. In Phase I coils with a limited number of turns were successfully wound and tested at 77 K for both coil configurations. The Phase II program concentrated on the design, coil winding procedures, structural analysis, prototyping and testing of an HTS curved dipole coil at 40 K with a heat load representative of the radiation environment. One of the key criteria of the design of this magnet is to avoid the use of organic materials that would degrade rapidly in radiation. The Lorentz forces expected from the coils interacting with the magnetic field are large and in order minimize the deformation of the coils, mechanical support must be provided. Since the support structure cannot be made of organic materials with minimal thermal conductivity, an optimization was explored comparing the amount of coil deformation that can be tolerated and the amount of heat leakage that can be endured. A test coil containing 500 m of HTS was constructed to be tested at the 40 K operating temperature. The anticipated heat load was simulated with heater strips to demonstrate that the heat could be removed and that the coil can operate in a stable state. The FRIB project has decided that using HTS coils for this magnet was too risky considering their time and funding constraints and has opted for a more conservative approach with conventional coils. As an outcome of this STTR project, it is likely that HTS coils operating at higher temperatures will have beneficial applications for future accelerator projects.

  12. Prediction of Separation Performance of Dry High Intensity Magnetic Separator for Processing of Para-Magnetic Minerals

    Science.gov (United States)

    Tripathy, Sunil Kumar; Singh, Veerendra; Suresh, Nikkam

    2015-10-01

    High intensity dry magnetic separators are gaining popularity for the separation of para-magnetic minerals due to the cost economic factor. Induced roll magnetic separator is found to be an effective dry separator for the separation of fine particles. Separation efficiency of this separator depends on mineral characteristics and the design features of equipment along with the optimization of process variables. Present investigation focuses on the prediction and validation of separation performance of minerals while treating in induced roll magnetic separator. Prediction of the separation is expressed in terms of separation angle at which a particle leaves the rotor surface by using a modified particle flow model derived by Cakir. The validation of the model is carried by capturing the particle trajectory using an image analyzer. It is found that Cakir's mathematical model produces reliable results and a new model is proposed to increase the reliability of separation angle prediction by including the particle shape factor.

  13. Separation of magnetic susceptibility components from magnetization curves

    Science.gov (United States)

    Kosareva, L.; Nourgaliev, D.; Kuzina, D.; Spassov, S.; Fattakhov, A.

    2014-12-01

    Modern lake sediments are a unique source of information for climate changes, regionally and globally, because all environmental variations are recorded by these sediments with high resolution. The magnetic properties of Chernyshov Bay (Aral Sea) sediments we investigated from core number 4 (N45o57'04.2''; E59o17'14.3'') are taken at far water depth of 9.5 m. The length of the core is 4.16 m. Samples for measurements were taken to plastic sample boxes with internal dimensions 2x2x2 cm. Remanent magnetization curves were measured by coercivity spectrometer for the separate determination of the different contributions to the total bulk magnetic susceptibility. There was measured also magnetic susceptibility using MS2 susceptibility meter. Those operations were done for data comparison between 2 susceptibilities obtained from different equipment. Our goal is to decipher the magnetic susceptibility signal in lake sediments by decomposing the bulk susceptibility signal of a lake sediment sequence into ferromagnetic (?f), dia-/paramagnetic (?p) and superparamagnetic (?sp) components using data from remanent and indused magnetization curves Each of these component has a different origin: paramagnetic minerals are usually attributed to terrigenous sediment input, ferromagnetics are of biogenic origin, and superparamagnetic minerals may be of either biogenic or terrigenous origin. Comparison between susceptibility measurements of MS2-Bartington susceptometer and of the coercivity spectrometer has shown good correlation. The susceptibility values measured in two different equipment are fairly close and indicate thus the reliability the proposed method. In research also has shown water level changes in Aral Sea based on magnetic susceptibility. The work is performed according to the Russian Government Program of Competitive Growth of Kazan Federal University also by RFBR research projects No. 14-05-31376 - ?, 14-05-00785- ?.

  14. Magnetic force on a magnetic particle within a high gradient magnetic separator

    International Nuclear Information System (INIS)

    Highlights: ? Magnetic field and the gradient decide magnetic force on a particle in HGMS (High Gradient Magnetic Separation). ? We calculated the field and the gradient of a superconducting HGMS system by finite element method. ? We could calculate magnetic force on a particle consisting of major impurities in the condenser water of a thermal power station. -- Abstract: HGMS (High Gradient Magnetic Separator) uses matrix to make high magnetic field gradient so that ferro- or para-magnetic particles can be attracted to them by high magnetic force. The magnetic force generated by the field gradient is several thousand times larger than that by background magnetic field alone. So the HGMS shows excellent performance compared with other magnetic separators. These matrixes are usually composed of stainless steel wires having high magnetization characteristics. This paper deals with superconducting HGMS which is aimed for purifying waste water by using stainless steel matrix. Background magnetic field up to 6 T is generated by a superconducting solenoid and the stainless steel matrixes are arranged inside of the solenoid. Based on magnetic field calculated by FEM (Finite Element Method), we could calculate magnetic force acting on a magnetic particle such as hematite and maghemite consisting of major impurities in the condenser water of a thermal power station

  15. The design of the drum separator with superconducting magnets

    Energy Technology Data Exchange (ETDEWEB)

    Sidorenko, V.D.; Gerasimenko, I.A.; Kretinin, E.A. [Mekhanobrchermet Inst., Krivoy Rog (Ukraine). Lab. for Superconducting Technique and Technologies; Zhelamsky, M.V.; Bondarchuk, E.N.; Rodin, I.Y.; Muratov, V.P. [Scientific and Research Inst. of Electrophysical Apparatus, St. Petersburg (Russian Federation)

    1996-07-01

    This paper describes the open gradient drum type magnetic separator with superconducting magnet system to develop technologies for dry separation of low magnetic mineral raw material of 4-0 mm (medium size) up to 25-0 mm (coarse size). The separation zone is 1200 mm x 50 mm with the magnet system-wrap angle equal to 90{degree}, the magnetic field in the separation zone is at the level of 4.5 T, the average value of the magnetic forces is 120 T{sup 2}/m and the capacity is about 100 t/h. The results of the optimization and numerical calculations of thermophysical processes in magnetic and cryogenic systems are given. The technological developments of the design of some separator units are presented. The paper also presents the techno-economic indices of the separator application at the ore-mining operations.

  16. High-gradient magnetic separation using ferromagnetic membrane

    Science.gov (United States)

    Podoynitsyn, Sergey N.; Sorokina, Olga N.; Kovarski, Alexander L.

    2016-01-01

    The magnetic separator with the membrane separating unit made of laser-perforated thick ferromagnetic foil was tested using composite water suspension of magnetic nanoparticles adsorbed on hydroxylapatite microparticles. The average sizes of the particles in the suspension and the magnetic moment of the suspension were measured by dynamic light scattering and electron magnetic resonance correspondingly to evaluate the efficiency of the separation. It was shown experimentally that the separation is effected by the membrane type and the flow rate. Magnetic coarse grains (larger than 1 ?m) were captured by the membrane preferably and the magnetic moment of the suspension decreased by 20-25% after the separation. The magnetic field simulation and experimental results demonstrate the higher separation efficiency for thicker membranes.

  17. Creation of superconducting magnet separators for weakly magnetic mineral raw material processing

    Energy Technology Data Exchange (ETDEWEB)

    Sidorenko, V.D.; Gerasimenko, I.A.; Kutin, A.M. [Mekhanobrchermet Inst., Krivoy Rog (Ukraine); Yupherov, V.B.; Skibenko, Y.I. [National Research Centre Kharkov Physico-Technical Inst. (Ukraine); Gladky, V.V. [Inst. of Low Temperature Physics and Engineering, Kharkov (Ukraine)

    1996-07-01

    The paper describes the investigations to work out the design and process parameters of superconducting commercial separators using laboratory units. The design features of the magnet system and the cryostat of the separator of the disk type for wet separation of weakly magnetic ores and non-ore materials are presented. The results of modelling the technological flowsheets for separation of various types of weakly magnetic material using SC magnetic separators are given. The necessity to further improve the magnetic separators in the direction of generation of the magnetic flux higher magnetic forces and densities is well-grounded.

  18. Magnetic separation technique for environmental water purification by strong magnetic field generator loading HTS bulk magnets

    International Nuclear Information System (INIS)

    The magnetic separation technique in combination with high temperature superconducting bulk magnets has been investigated to purify the ground water which has been used in the coolant system for the incinerator furnace to cool the burning gas. The experiment has been operated by means of the newly-built alternating channel type magnetic separating device. The separation ratios of ferromagnetic flocks including fine magnetite powder have been estimated by means of the high gradient magnetic separation method with small iron balls filled in the water channels. As the magnetic force acting on the magnetic particle is given by the product of a magnetization of the material and a gradient of magnetic field, and as the ferromagnetic stainless steel balls yield the steep gradient of magnetic field around them in a strong magnetic field, the system has exhibited a quite excellent performance with respect to the separation ratios. The separation ratios of the flocks which contain the magnetite powder with the values more than 50 ppm have remained over 80% for under the flow rates less than 5 L/min.

  19. Highly efficient magnetic separation using five-aligned superconducting bulk magnet

    International Nuclear Information System (INIS)

    We have constructed the highly efficient magnetic separation system using five-aligned superconducting bulk magnets, which has ten usable magnetic poles on both sides in open space. We applied the bulk magnet system to the magnetic separation of ferromagnetic particles (magnetite; Fe3O4) and paramagnetic ones (?-hematite; Fe2O3) dispersed in water for various average particle diameters d, flow speeds VF and initial concentrations C0 of the particles. The multi-bulk magnet system has been confirmed to be effective for the magnetic separation and the efficiency of the magnetic separation per one magnetic pole has been estimated using the theoretical relation.

  20. Inverted Linear Halbach Array for Separation of Magnetic Nanoparticles

    OpenAIRE

    Ijiri, Y.; Poudel, C.; Williams, P.S.; Moore, L R; Orita, T.; Zborowski, M.

    2013-01-01

    A linear array of Nd-Fe-B magnets has been designed and constructed in an inverted Halbach configuration for use in separating magnetic nanoparticles. The array provides a large region of relatively low magnetic field, yet high magnetic field gradient in agreement with finite element modeling calculations. The magnet assembly has been combined with a flow channel for magnetic nanoparticle suspensions, such that for an appropriate distance away from the assembly, nanoparticles of higher moment...

  1. MSWI boiler fly ashes: magnetic separation for material recovery.

    Science.gov (United States)

    De Boom, Aurore; Degrez, Marc; Hubaux, Paul; Lucion, Christian

    2011-07-01

    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 pilot. BFA magnetic separation is economically evaluated. This study globally shows that it is possible to extract some magnetic particles from MSWI boiler fly ashes. However, the magnetic particles only represent from 23 to 120 g/kg of the BFA and, though they are enriched in Fe, are composed of similar elements to the raw ashes. The industrial application of magnetic separation would only be profitable if large amounts of ashes were treated (more than 15 kt/y), and the process should be ideally completed by other recovery methods or advanced treatments. PMID:21306886

  2. Electron spin separation without magnetic field.

    Science.gov (United States)

    Paw?owski, J; Szumniak, P; Skubis, A; Bednarek, S

    2014-08-27

    A nanodevice capable of separating spins of two electrons confined in a quantum dot formed in a gated semiconductor nanowire is proposed. Two electrons confined initially in a single quantum dot in the singlet state are transformed into the system of two electrons confined in two spatially separated quantum dots with opposite spins. In order to separate the electrons' spins we exploit transitions between the singlet and the triplet state, which are induced by resonantly oscillating Rashba spin-orbit coupling strength. The proposed device is all electrically controlled and the electron spin separation can be realized within tens of picoseconds. The results are supported by solving numerically the quasi-one-dimensional time-dependent Schroedinger equation for two electrons, where the electron-electron correlations are taken into account in the exact manner. PMID:25106038

  3. Application of HTS bulk magnet system to the magnetic separation techniques for water purification

    International Nuclear Information System (INIS)

    We have investigated the application of the HTS bulk magnets to the magnetic separation techniques for the waste water drained from the university laboratories. The study has been conducted in comparison with the electromagnets, and the cryo-cooled superconducting solenoid magnet. A superconducting bulk magnet has the highest value of the trapped magnetic fields at the centre of the sample surface, showing a sharp gradient of the magnetic field on the surface. Magnetic force acting on magnetic particles in magnetic fields is given by the product of a magnetization of particles and a gradient of magnetic field. The HTS bulk is superior to a solenoid magnet which has a poor gradient in magnetic fields in a bore. The separation ratios of ferrite precipitates in the waste slurry were estimated by means of the high gradient magnetic separation method which requires iron filters in the water channel and open gradient magnetic separation without any filters. The magnetic separation using HTS bulk magnet is substantially effective for the practical water purification

  4. MAGNETITE RECOVERY IN COAL WASHING BY HIGH GRADIENT MAGNETIC SEPARATION

    Science.gov (United States)

    The report describes a demonstration of the successful recovery of magnetite from mixtures of magnetite and coal, like those found in a coal-washing circuit, by High Gradient Magnetic Separation. The demonstration was part of a research program at Francis Bitter National Magnet L...

  5. Estimation of magnet separation for magnetic suspension applications

    OpenAIRE

    Parfitt, Maxwell

    2013-01-01

    This thesis describes a form of non-contact measurement using two dimensional hall effect sensing to resolve the location of a moving magnet which is part of a magnetic spring type suspension system. This work was inspired by the field of Space Robotics, which currently relies on solid link suspension techniques for rover stability. This thesis details the design, development and testing of a novel magnetic suspension system with a possible application in space and terrestrial based robotic...

  6. Electromagnet with two coils separated by magnetic wall

    International Nuclear Information System (INIS)

    The electromagnet comprises a magnetic core with a magnetic wall fixed to it separating two coaxial coils, a casing surrounding the coils and magnetically coupled to the wall, and a carrying face at the end of the casing, arranged so that the carrying force exerted by energising one of the coils is less than that exerted by energising the other. The invention applies for holding nuclear reactor control rods. The force exerted on a control rod can be varied with its position

  7. "On-chip magnetic bead microarray using hydrodynamic focusing in a passive magnetic separator"

    DEFF Research Database (Denmark)

    Smistrup, Kristian; Kjeldsen, B.; Reimers, R.L.; Dufva, Hans Martin; Petersen, J.; Hansen, Mikkel Fougt

    2005-01-01

    Implementing DNA and protein microarrays into lab-on-a-chip systems can be problematic since these are sensitive to heat and strong chemicals. Here, we describe the functionalization of a microchannel with two types of magnetic beads using hydrodynamic focusing combined with a passive magnetic separator with arrays of soft magnetic elements. The soft magnetic elements placed on both sides of the channel are magnetized by a relatively weak applied external magnetic field ( 21 mT) and provide magn...

  8. Study on magnetic separation system using high Tc superconducting bulk magnets for water purification technique

    International Nuclear Information System (INIS)

    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.

  9. On Poor Separation in Magnetically Driven Shock Tube

    DEFF Research Database (Denmark)

    Chang, C.T.

    1973-01-01

    Observations made at steady-state running conditions in a magnetically driven shock tube, with parallel-plate electrodes, showed that for a given discharge voltage, sufficient separation between the shock and the current-sheet occurred only at relatively high discharge pressures. As a comparison, poor separations were also noted in conventional diaphragm-type shock tubes running at low initial pressures. It is demonstrated that the observed poor separation can be explained by a mass leakage, ins...

  10. Use of high gradient magnetic separation for actinide application

    International Nuclear Information System (INIS)

    Decontamination of materials such as soils or waste water that contain radioactive isotopes, heavy metals, or hazardous components is a subject of great interest. Magnetic separation is a physical separation process that segregates materials on the basis of magnetic susceptibility. Because the process relies on physical properties, separations can be achieved while producing a minimum of secondary waste. Most traditional physical separation processes effectively treat particles larger than 70 microns. In many situations, the radioactive contaminants are found concentrated in the fine particle size fraction of less than 20 microns. For effective decontamination of the fine particle size fraction most current operations resort to chemical dissolution methods for treatment. High gradient magnetic separation (HGMS) is able to effectively treat particles from 90 to ?0.1 micron in diameter. The technology is currently used on the 60 ton per hour scale in the kaolin clay industry. When the field gradient is of sufficiently high intensity, paramagnetic particles can be physically captured and separated from extraneous nonmagnetic material. Because all actinide compounds are paramagnetic, magnetic separation of actinide containing mixtures is feasible. The advent of reliable superconducting magnets also makes magnetic separation of weakly paramagnetic species attractive. HGMS work at Los Alamos National Laboratory (LANL) is being developed for soil remediation, waste water treatment and treatment of actinide chemical processing residues. LANL and Lockheed Environmental Systems and Technologies Company (LESAT) have worked on a co-operative research and development agreement (CRADA) to develop HGMS for radioactive soil decontamination. The program is designed to transfer HGMS from the laboratory and other industries for the commercial treatment of radioactive contaminated materials. 9 refs., 2 figs., 2 tabs

  11. Low field orientation magnetic separation methods for magnetotactic bacteria

    International Nuclear Information System (INIS)

    Microbial biomineralisation of iron often results in a biomass that is magnetic and can be separated from water systems by the application of a magnetic field. Magnetotactic bacteria form magnetic membrane bound crystals within their structure, generally of magnetite. In nature, this enables magnetotactic bacteria to orientate themselves with respect to the local geomagnetic field. The bacteria then migrate with flagellar driven motion towards their preferred environment. This property has been harnessed to produce a process in which metal loaded magnetotactic bacteria can be recovered from a waste stream. This process is known as orientation magnetic separation. Several methods exist which permit the unique magnetic properties of individual magnetotactic bacteria to be studied, such as U-turn analysis, transmission electron microscopy and single wire cell studies. In this work an extension of U-turn analysis was developed. The bacteria were rendered non-motile by the addition of specific metal ions and the resulting 'flip time' which occurs during a field reversal enabled the magnetic moment of individual bacteria to be determined. This method proved to be much faster and more accurate than previous methods. For a successful process to be developed, large scale culturing of magnetotactic bacteria is required Experiments showed that culture vessel geometry was an important factor for high-density growth. Despite intensive studies reproducible culturing at volumes exceeding one litre was not achieved. This work showed that numerous metal ions rendered magnetotactic bacteria non-motile at concentrations below 10 ppm. Sequential adaptation raised typical levels to in excess of 100 ppm for a number of ions. such as zinc and tin. However, specific ions. such as copper or nickel, remained motility inhibiting at lower concentrations. To achieve separation using orientation magnetic separation, motile, field susceptible MTB are required. Despite successful adaptation, the range of motility inhibiting ions is such that MTB cannot be envisaged for general wastewater applications. Radionucleide studies were undertaken targeting a niche application where this metal ion restriction would not apply. Liquid scintillation and ?-ray counting measurements indicated that magnetotactic bacteria accumulate high levels of both plutonium and mercury. A number of both static and flow recovery separators for magnetotactic bacteria were developed. Statistical models predicting the behaviour of these separators were compared to measured results. These comparisons highlighted the problems of 'wash off' of accumulated bacteria in separators where flow was present. The most successful of the flow recovery designs - the channel separator - was then tested using a simulated effluent that contained plutonium. The results confirmed both previous radioisotope uptake studies and separator test results. The channel separator design was enhanced by the introduction of wire arrays into the separation chamber. Orientation magnetic separation in these hybrid-type separators was used to accumulate the biomass and the magnetic gradients generated by the wire arrays to retain the bacteria on the separator walls. These separators achieved increases in efficiency of up to 300% compared with the channel separator. In summary, this thesis describes a successful separation process for the recovery of motile MTB. However, to apply this separator approach to the suggested radioisotope application would require successful large scale culturing. (author)

  12. Bench-scale magnetic separation of Department of Energy wastes

    International Nuclear Information System (INIS)

    Criteria were developed for selection of candidate wastes for testing magnetic separation of uranium and/or other paramagnetic materials. A survey of Department of Energy (DOE) hazardous wastes was conducted to determine good candidates for bench-scale magnetic separation tests. Representatives of 21 DOE sites were contacted, and 11 materials were identified as potential candidates for magnetic separation. To date, seven samples have been obtained and tested for separability of uranium with a bench-scale magnetic assaying device. The samples tested have been obtained from the K-1401B and K-1401C ponds in Oak Ridge, Tennessee; from waste piles in Maywood, New Jersey; from North and South Ponds in Richland, Washington; and from magnesium fluoride drums in Fernald, Ohio. The magnetic device utilized in these tests can be used in an open-gradient mode with dry particulate or liquid-suspended materials. Uranium separation from magnesium fluoride has shown exceptionally good performance in both open- and high-gradient modes and could be an important application of the technology

  13. Iso-geometric shape optimization of magnetic density separators

    DEFF Research Database (Denmark)

    Dang Manh, Nguyen; Evgrafov, Anton

    2014-01-01

    Purpose The waste recycling industry increasingly relies on magnetic density separators. These devices generate an upward magnetic force in ferro-fluids allowing to separate the immersed particles according to their mass density. Recently, a new separator design has been proposed that significantly reduces the required amount of permanent magnet material. The purpose of this paper is to alleviate the undesired end-effects in this design by altering the shape of the ferromagnetic covers of the individual poles. Design/methodology/approach The paper represents the shape of the ferromagnetic pole covers with B-splines and defines a cost functional that measures the non-uniformity of the magnetic field in an area above the poles. The authors apply an iso-geometric shape optimization procedure, which allows us to accurately represent, analyze and optimize the geometry using only a few design variables. The design problem is regularized by imposing constraints that enforce the convexity of the pole cover shapes and is solved by a non-linear optimization procedure. The paper validates the implementation of the algorithm using a simplified variant of the design problem with a known analytical solution. The algorithm is subsequently applied to the problem posed. Findings The shape optimization attains its target and yields pole cover shapes that give rise to a magnetic field that is uniform over a larger domain. Research limitations/implications This increased magnetic field uniformity is obtained at the cost of a pole cover shape that differs per pole. This limitation has negligible impact on the manufacturing of the separator. The new pole cover shapes therefore lead to improved performance of the density separation. Practical implications Due to the larger uniformity the generated field, these shapes should enable larger amounts of waste to be processed than the previous design. Originality/value This paper treats the shapes optimization of magnetic density separators systematically and presents new shapes for the ferromagnetic poles covers.

  14. Novel platform for minimizing cell loss on separation process: Droplet-based magnetically activated cell separator

    Science.gov (United States)

    Kim, Youngho; Hong, Su; Lee, Sang Ho; Lee, Kangsun; Yun, Seok; Kang, Yuri; Paek, Kyeong-Kap; Ju, Byeong-Kwon; Kim, Byungkyu

    2007-07-01

    To reduce the problem of cell loss due to adhesion, one of the basic phenomena in microchannel, we proposed the droplet-based magnetically activated cell separator (DMACS). Based on the platform of the DMACSwhich consists of permanent magnets, a coverslip with a circle-shaped boundary, and an injection tubewe could collect magnetically (CD45)-labeled (positive) cells with high purity and minimize cell loss due to adhesion. To compare separation efficiency between the MACS and the DMACS, the total number of cells before and after separation with both the separators was counted by flow cytometry. We could find that the number (3241/59940) of cells lost in the DMACS is much less than that (22360/59940) in the MACS while the efficiency of cell separation in the DMACS (96.07%) is almost the same as that in the MACS (96.72%). Practically, with fluorescent images, it was visually confirmed that the statistical data are reliable. From the viability test by using Hoechst 33 342, it was also demonstrated that there was no cell damage on a gas-liquid interface. Conclusively, DMACS will be a powerful tool to separate rare cells and applicable as a separator, key component of lab-on-a-chip.

  15. On heteroclinic separators of magnetic fields in electrically conducting fluids

    CERN Document Server

    Grines, V; Pochinka, O; Zhuzhoma, E

    2014-01-01

    In this paper we partly solve the problem of existence of separators of a magnetic field in plasma. We single out in plasma a 3-body with a boundary in which the movement of plasma is of special kind which we call an (a-d)-motion. We prove that if the body is the 3-annulus or the "fat" orientable surface with two holes the magnetic field necessarily have a heteroclinic separator. The statement of the problem and the suggested method for its solution lead to some theoretical problems from Dynamical Systems Theory which are of interest of their own.

  16. Magnetic driven separation techniques - DNA isolation from probiotic food samples.

    Czech Academy of Sciences Publication Activity Database

    Trachtov, S.; panov, A.; Prettl, Z.; Hork, Daniel; Rittich, B.

    Wroclaw : Institute of Immunology and Experimental Therapy Polish Academy of Science , 2013 - (Gamian, A.; Grska-Fraczek, S.). s. 27 ISBN 978-83-928488-3-7. [Polish-Czech Probiotics Conference /1./ - Microbiology and Immunology of Mucosa, Probiotics Conference 2013. 28.05.2013-31.05.2013, Kudowa Zdrj] R&D Projects: GA ?R GAP206/12/0381 Institutional support: RVO:61389013 Keywords : magnetic * DNA * separation Subject RIV: CB - Analytical Chemistry, Separation

  17. Ultrasound imaging for quantitative evaluation of magnetic density separation:

    OpenAIRE

    Sanaee, S.A.

    2013-01-01

    This thesis is dedicated to an investigation of the potential and technological possibilities of an inline ultrasound system as a quality control system for wet recycling of solid waste. The main targeted recycling technology is magnetic density separation (MDS), a novel technique that was investigated and technologically matured in a project running in parallel to this work. In MDS, the easily magnetisable ferrofluid is used as the separation medium to sort different materials based on their...

  18. An experimental investigation of the effect of preliminary magnetization in magnetic separation

    International Nuclear Information System (INIS)

    The effects of preliminary magnetization on the high-gradient magnetic separation of hematite and uranium-gold leach residues were studied. It is shown that the pre-magnetization of anti-ferromagnetic hematite can enhance the recovery of iron and the grade of the magnetic product. The effect of pre-magnetization was found to increase with decreasing particle size, the recovery from the fraction -12 ?m increasing by 11% and the grade of the magnetic concentrate by 30%. The pre-magnetization of paramagnetic uranium-gold leach residues, however, reduced the recovery of uranium. It is suggested that the behaviour of a mineral with an ordered magnetic structure is related to magnetic viscosity. The capital and operating costs of the magnet required for pre-magnetization are assessed. (orig.)

  19. On Poor Separation in Magnetically Driven Shock Tube

    DEFF Research Database (Denmark)

    Chang, C.T.

    1973-01-01

    Observations made at steady-state running conditions in a magnetically driven shock tube, with parallel-plate electrodes, showed that for a given discharge voltage, sufficient separation between the shock and the current-sheet occurred only at relatively high discharge pressures. As a comparison......, poor separations were also noted in conventional diaphragm-type shock tubes running at low initial pressures. It is demonstrated that the observed poor separation can be explained by a mass leakage, instead of through the wall boundary layer, but through the current-sheet itself....

  20. Passive magnetic separator integrated with microfluidic mixer: Demonstration of enhanced capture efficiency

    DEFF Research Database (Denmark)

    Lund-Olesen, Torsten; Bruus, Henrik; Hansen, Mikkel Fougt

    In this paper, we present two results: (1) a new method for quantifying the efficiency of magnetic bead separators by magnetic measurements, and (2) a new idea for designing efficient magnetic bead separators. For microfluidic magnetic separators, a limiting factor for the capture of magnetic beads...... enhances the bead capture-and-release efficiency....

  1. Separation of the Magnetic Field into External and Internal Parts

    DEFF Research Database (Denmark)

    Olsen, Nils; Glassmeier, K.-H.

    2010-01-01

    The magnetic field of a planet or a planetary moon contains contributions from a variety of sources in the environment of the body (external sources) and its interior (internal sources). This chapter describes different methods that have been developed for the separation of external and internal source contributions, and their application to selected planets and one of Jupiters moons, Ganymede.

  2. Separation of the Magnetic Field into External and Internal Parts

    DEFF Research Database (Denmark)

    Olsen, Nils; Glassmeier, K.-H.; Jia, X.

    The magnetic field of a planet or a planetary moon contains contributions from a variety of sources in the environment of the body (external sources) and its interior (internal sources). This chapter describes different methods that have been developed for the separation of external and internal...... source contributions, and their application to selected planets and one of Jupiter’s moons, Ganymede....

  3. Magnetic Separations with Magnetite: Theory, Operation, and Limitations

    Energy Technology Data Exchange (ETDEWEB)

    G. B. Cotten

    2000-08-01

    This dissertation documents the theory development and experimental plan followed to describe how a magnetite-based column under the influence of an external magnetic field functions as a magnetic separator. Theoretical simulations predict that weekly paramagnetic particles in the sub-micron range can be magnetically separated while diamagnetic particles as large as 2 microns in diameter may pass. Magnetite-based columns were evaluated as magnetically-controllable enhanced filtration devices. There was no evidence of enhanced filtration for diamagnetic particles by the magnetite-based bed. Magnetite-based magnetic separators have proven to be effective in specific laboratory experiments, indicating a potential feasibility for scale-up operations. Column media-filter type filtration effects indicate a magnetite-based column would not be suitable for treatment of a waste stream with a high diamagnetic solids content or high volume throughput requirements. Specific applications requiring removal of sub-micron para- or ferromagnetic particles under batch or Stokes flow conditions would be most applicable.

  4. Magnetic separation using high-T sub c superconductors

    CERN Document Server

    Bolt, L

    2001-01-01

    sensitivity of the high-T sub c material to magnetic fields. Finite elements modelling of the system has provided the framework for the quantitative analysis of the magnetic field distributions on the coil windings and the optimisation of the system configuration. The performance of the separator has been tested at 77 K with liquid nitrogen at atmospheric pressure, and at a temperature approx = 67 K by pumping liquid nitrogen at a pressure around 100 Torr. The highest field obtained in the air gap at 67 K was of 340 mT. Magnetic separators with an iron circuit have been in operation for many years in mineral industry, and there appear to be an opportunity of building machines with high-T sub c coils or retrofitting existing machines with high-T sub c coils to run them closer to saturation in a cheap and effective way. Superconductivity has found in magnetic separation one of its major industrial applications second only to magnetic resonance imaging. Low-T sub c superconducting coils have been employed in Hig...

  5. Magnetic Separations with Magnetite: Theory, Operation, and Limitations

    International Nuclear Information System (INIS)

    This dissertation documents the theory development and experimental plan followed to describe how a magnetite-based column under the influence of an external magnetic field functions as a magnetic separator. Theoretical simulations predict that weekly paramagnetic particles in the sub-micron range can be magnetically separated while diamagnetic particles as large as 2 microns in diameter may pass. Magnetite-based columns were evaluated as magnetically-controllable enhanced filtration devices. There was no evidence of enhanced filtration for diamagnetic particles by the magnetite-based bed. Magnetite-based magnetic separators have proven to be effective in specific laboratory experiments, indicating a potential feasibility for scale-up operations. Column media-filter type filtration effects indicate a magnetite-based column would not be suitable for treatment of a waste stream with a high diamagnetic solids content or high volume throughput requirements. Specific applications requiring removal of sub-micron para- or ferromagnetic particles under batch or Stokes flow conditions would be most applicable

  6. Feasibility study of iron mineral separation from red mud by high gradient superconducting magnetic separation

    International Nuclear Information System (INIS)

    Research highlights: → Red mud residues (RM) were disposed in alumina production. → Utilization of Red mud residues was affected by its iron content. → Superconducting magnetic separation (HGSMS) was used in iron separation from RM. → RM with high and low iron contents were separated in HGSMS. - Abstract: The disposal of bayer red mud tailings now seriously threats the environment safety. Reduction and recycling of red mud is now an urgent work in aluminum industry. High gradient superconducting magnetic separation (HGSMS) system was applied to separate the extreme fine RM particles (<100 μm) into high iron content part and low iron content part. Two sorts of RM were fed in the HGSMS. The iron oxide contents in concentrates were about 65% and 45% when RM 1 and RM 2 were fed respectively. Meanwhile, the residues contained 52.0% or 14.1% iron oxide in residues after eight separation stages when RM 1 and RM 2 were fed respectively. The mass recovery of iron concentrates was about 10% after once separation process regardless of RM 1 or RM 2 was fed. Extreme fine particles (<10 μm) could be captured in the HGSMS. Intergrowth of Fe and other elements is disadvantages for iron mineral separation from RM by HGSMS. Some improvement should be studied to enhance the efficiency of iron separation. It is possible for HGSMS to separate RM into high iron content part and low iron content part, the former part could be used in iron-making furnace and the later part could be recycling to sintering process for alumina production or used as construction material.

  7. Tank waste remediation system milestone report magnetic separation of tank waste: Surrogate system separations report

    Energy Technology Data Exchange (ETDEWEB)

    Avens, L.R.; Worl, L.A.; Schake, A.R.; Padilla, D.D.; de Aguero, K.J.; Prenger, F.C.; Stewart, W.F.; Hill, D.D.

    1994-01-14

    High-level radioactive waste (HLW) has been stored in large underground storage tanks (UST) at the US Department of Energy`s Hanford Site since 1944. More than 253,000 m{sup 3} of waste have been accumulated in 177 tanks. The waste consists of many different chemicals and are in the form of liquids, slurries, salt cakes and sludges. A magnetic separation effort at Los Alamos National Laboratory is funded through the Tank Waste Remediation System (TWRS) to explore the use of high-gradient magnetic separation (HGMS) for tank waste segregation. The concept is to concentrate into a low volume waste stream, all or most of the magnetic components, which include actinide compounds, most of the fission products and precious metals. As a first step in this process investigations were made on surrogate systems. This milestone report discusses the HGMS results on these systems.

  8. Maximizing the recovery of fine iron ore using magnetic separation

    Scientific Electronic Library Online (English)

    M, Dworzanowski.

    2012-03-01

    Full Text Available The beneficiation of fine iron ore will increase in importance in the future because most new iron ore resources will be in the form of lower grade ore deposits that will require liberation of iron ore minerals at finer sizes. Generally this fine iron ore will be benefi-ciated to produce a pelletizi [...] ng concentrate with very strict chemical and physical specifications. In addition, because of the increasing demand for iron ore there are now more opportunities to produce by-product iron ore from mining operations producing other commodities. In the past the associated iron ore minerals would report to final tailings but now there is potential value to be realised from by-product revenue. These by-product iron ore opportunities are almost all centred on producing pelletizing concentrate. Currently pelletizing concentrates are produced mainly by various combinations of flotation and magnetic separation. The selection of the beneficiation route will depend on ore mineralogy and considerations around plant capacity and final concentrate quality. The main economic iron minerals are magnetic, haematite being paramagnetic and magnetite being ferromagnetic. This, therefore, means that magnetic separation can be applied, in principle, to all fine iron-ore beneficiation plants. While flotation has a considerable capacity advantage over magnetic separation, the real advantage of magnetic separation over flotation in fine iron-ore beneficiation is that treatment of -10 m iron ore is possible-in flotation, the feed is deslimed at 10 m and the -10 m stream is considered to be final tailings, even though there is often a significant amount of contained iron ore. This paper describes a study around the recovery of fine magnetite in the form of a pelletizing concentrate. The study is based on an evaluation of an iron ore by-product opportunity from an iron oxide copper-gold (IOCG) deposit. Experiments were conducted to quantify the differences in magnetic separation performance with decrease in particle size treated. A mineralogical evaluation of all the test work products was undertaken to facilitate the interpretation of the test work results. These results were then used to propose an economically viable flowsheet for maximizing fine magnetite recovery using magnetic separation.

  9. The electromagnetic design of a permanent magnet based separator

    International Nuclear Information System (INIS)

    The aim of this work was to design a permanent magnet based device that can selectively transport paramagnetic particles. Using specialised electromagnetic design software various arrangements of permanent magnets have been investigated. Each test geometry had to be constructively simple and able to produce highly non-uniform magnetic fields before being considered further in any more detail. The main parameter to indicate that the test geometry might be a suitable device has been ascribed to the ratio η between the highest (ON) and lowest (OFF) magnetic fields that were measured. A linear arrangement of permanent magnets has been considered first. This device produced a ratio η ∼ 2. Further, the cylindrical and the tubular arrangements may be considered as substantial improvements over the first geometry. The OFF magnetic fields have been substantially reduced by the method of magnetic shielding. Intensive research and modelling has been spent on addressing the problem of finding the optimal geometry for such arrangements. An experimental system has been also built, and the experimental values were compared against the theory. However, the results produced evidence that the manufacturing of any improved geometry (an estimated η ∼ 100) in this direction might be very difficult, for the tolerances involved were very strict. The disk arrangement was the latest device to be investigated. Particularly, a magnetic dipole model developed earlier for the ring arrangement suggested the way in which to arrange the magnets in the ON position. Moreover, the use of the magnetic symmetry of the device forced the OFF magnetic fields to negligible values. Detailed computer simulations of the dynamics of the particles in the applied magnetic field of the tubular and disk arrangements have been earned out. The adopted models could show realistic phenomena, e.g. particle clustering, chaining, block movement, etc. The separation efficiency proved to be nearly 100%. For the disk arrangement the minimum paramagnetic susceptibility of the particle that could be transported has been χ ∼ 10-4. In addition, the particle radii had little influence on the functioning of this magnetic separation device. (author)

  10. Waste water purification by magnetic separation technique using HTS bulk magnet system

    International Nuclear Information System (INIS)

    We have investigated the feasibility of strong magnetic field generators composed of the high temperature superconducting (HTS) bulk magnet systems to the magnetic separation techniques for the waste water including thin emulsion bearing the cutting oil. Two types of the strong field generators were prepared by the face-to-face HTS bulk magnet systems, which emit the magnetic field density of 1 and 2 T in the open spaces between the magnetic poles activated by the pulsed field magnetization and the field cooling methods, respectively. A couple of water channels containing iron balls were settled in the strong field to trap the magnetized flocks in the waste water. The separation ratios of flocks containing 200 ppm magnetite powder were evaluated with respect to the flow rates of the waste water. The performances of bulk magnet system have kept showing values of around 100% until the flowing rate reached up to 18 l/min. This suggests that the magnetic separation by using bulk magnets is effective for the practical water purification systems.

  11. Magnetic separation as a plutonium residue enrichment process

    International Nuclear Information System (INIS)

    Several plutonium contaminated residues have been subjected to Open Gradient Magnetic Separation (OGMS) on an experimental scale. OGMS experiments on graphite and bomb reduction residues resulted in a plutonium rich fraction and a plutonium lean fraction. Values for the bulk quantity rejected to the lean fraction varied between about 20% to 85% of the feed bulk. The plutonium content of the lean fraction can be reduced from about 2% in the feed to the 0.1% to 0.5% range dependent on the portion of the feed rejected to this lean fraction. These values are low enough in plutonium to meet economic discard limits and be considered for direct discard. Magnetic separation of pyrochemical salts gave less favorable results. While a fraction very rich in plutonium could be obtained, the lean fraction plutonium content was too high for direct discard. This may still have chemical processing applications. OGMS experiments at low magnetic field strength on incinerator ash did give two fractions but the plutonium content of each fraction was essentially identical. Thus, no chemical processing advantage was identified for magnetic separation of this residue. 6 refs., 1 fig., 9 tabs

  12. Magnetic nano-sorbents for fast separation of radioactive waste

    International Nuclear Information System (INIS)

    In order to find a cost effective and environmentally benign technology to treat the liquid radioactive waste into a safe and stable form for resource recycling or ultimate disposal, this study investigates the separation of radioactive elements from aqueous systems using magnetic nano-sorbents. Our current study focuses on novel magnetic nano-sorbents by attaching DTPA molecules onto the surface of double coated magnetic nanoparticles (dMNPs), and performed preliminary sorption tests using heavy metal ions as surrogates for radionuclides. The results showed that the sorption of cadmium (Cd) and lead (Pb) onto the dMNP-DTPA conjugates was fast, the equilibrium was reached in 30 min. The calculated sorption capacities were 8.06 mg/g for Cd and 12.09 mg/g for Pb. After sorption, the complex of heavy elements captured by nano-sorbents can be easily manipulated and separated from solution in less than 1 min by applying a small external magnetic field. In addition, the sorption results demonstrate that dMNP-DTPA conjugates have a very strong chelating power in highly diluted Cd and Pb solutions (1-10 ?g/L). Therefore, as a simple, fast, and compact process, this separation method has a great potential in the treatment of high level waste with low concentration of transuranic elements compared to tradition nuclear waste treatment. (authors)

  13. Advantage of combining magnetic cell separation with sperm preparation techniques.

    Science.gov (United States)

    Said, Tamer M; Grunewald, Sonja; Paasch, Uwe; Glander, Hans-Juergen; Baumann, Thomas; Kriegel, Christian; Li, Liang; Agarwal, Ashok

    2005-06-01

    The selection of vital, non-apoptotic spermatozoa is a prerequisite for achieving optimal conception rates in assisted reproductive techniques. Magnetic cell sorting using annexin-V microbeads can effectively separate apoptotic and non-apoptotic spermatozoa. The objective of the present study was to optimize the integration of magnetic cell sorting in standard sperm preparations and to correlate the effect of different sperm preparation procedures on apoptotic markers. Semen specimens collected from 15 healthy donors were prepared by either density gradient centrifugation or by one-step sperm wash technique separately and in combination with magnetic cell sorting. The preparation methods were evaluated by assessment of semen parameters (motility, viability and morphology) as well as markers of apoptosis (levels of active caspase-3, integrity of membrane mitochondrial potential and externalization of phosphatidylserine). The apoptotic markers were measured using fluorochrome dyes coupled with flow cytometry. The results showed that the combination of density gradient centrifugation and annexin-V magnetic cell sorting was superior to all other sperm preparation methods in terms of providing motile, viable and non-apoptotic spermatozoa. This study clearly shows the advantage of integrating magnetic cell sorting as a part of sperm preparation, which in turn may positively affect the success rates of assisted reproductive techniques. PMID:15970004

  14. Magnetically modified biological materials as perspective adsorbents for large-scale magnetic separation processes.

    Czech Academy of Sciences Publication Activity Database

    Mosiniewicz-Szablewska, E.; afa?kov, Miroslava; afa?k, Ivo

    New York : Nova Science Publishers, 2010 - (Valencia, R.), s. 301-318 ISBN 978-1-60876-074-9. - ( Horizons in World Physics. 266) R&D Projects: GA MPO 2A-1TP1/094; GA Mk OC09052 Institutional research plan: CEZ:AV0Z60870520 Keywords : magnetically modified biological material * magnetic separation * biologically active compounds Subject RIV: CB - Analytical Chemistry, Separation

  15. Low-Intensity Magnetic Separation: Principal Stages of a Separator Development – What is the Next Step?

    OpenAIRE

    Bikbov, M. A.; Karmazin, V. V.; Bikbov, A. A.

    2004-01-01

    An analysis of the technological limitations of magnetite quartzite beneficiation illustrated the imperfections of the traditional classification by size. As an alternative to size classification, separation by the degree of magnetite grain liberation can be employed. Comparative analysis of the mineral phase properties of the magnetic separation feed and its magnetic product has confirmed that wet drum magnetic separators currently used for wet treatment of magnetite ores have a low selectiv...

  16. Study on magnetic separation for decontamination of cesium contaminated soil by using superconducting magnet

    International Nuclear Information System (INIS)

    Highlights: The method for the soil decontamination by the superconducting magnet is proposed. Magnetic separation of clay minerals was performed by HGMS. Soil separation ratio was evaluated by quantitative analysis using XRD. It is expected that HGMS can be applied to the actual soil decontamination. - Abstract: The accident of Fukushima Daiichi nuclear power plant caused the diffusion of radioactive cesium over the wide area. We examined the possibility of applying magnetic separation method using the superconducting magnet, which can process a large amount of the soil in high speed, to the soil decontamination and volume reduction of the radioactive cesium contaminated soil. Clay minerals are classified as 2:1 and 1:1 types by the difference of their layer structures, and these types of minerals are respectively paramagnetic and diamagnetic including some exception. It is known that most of the radioactive cesium is strongly adsorbed on the clay, especially on 2:1 type clay minerals. It is expected that the method which can separate only 2:1 type clay minerals selectively from the mixture clay minerals can enormously contribute to the volume reduction of the contaminated soil. In this study, the components in the clay before and after separation were evaluated to estimate the magnetic separation efficiency by using X-ray diffraction. From the results, the decontamination efficiency and the volume reduction ratio were estimated in order to examine the appropriate separation conditions for the practical decontamination of the soil

  17. Oil-field wastewater purification by magnetic separation technique using a novel magnetic nanoparticle

    Science.gov (United States)

    Liu, Zhuonan; Yang, Huihui; Zhang, Hao; Huang, Chuanjun; Li, Laifeng

    2012-12-01

    In the present work, oil-field wastewater purification through superconducting magnetic separation technique using a novel magnetic nanoparticle was investigated. The magnetic nanoparticle, which has a multi-shell structure with ferroferric oxide as core, dense nonporous silica as inter layer and mesoporous silica as outer layer, was synthesized by co-precipitation method. To functionalize the magnetic nanoparticle, plasma polymerization technique was adopted and poly methyl acrylate (PMA) was formed on the surface of the nanoparticle. The multi-shell structure of the nanoparticle was confirmed by transmission electron microscope (TEM) and the characteristic is measurable by FTIR. It is found that most of the pollutants (85% by turbidity or 84% by COD value) in the oil-field wastewater are removed through the superconducting magnetic separation technique using this novel magnetic nanoparticle.

  18. Magnetic Separation for Nuclear Material Detection and Surveillance

    International Nuclear Information System (INIS)

    A high performance superconducting magnet is being developed for particle retrieval from field collected samples. Results show that maximum separation effectiveness is obtained when the matrix fiber diameter approaches the diameter of the particles to be captured. Experimentally, the authors obtained a single particle capture limit with 0.8microm PuO2 particles with dodecane as a carrier fluid. The development of new matrix materials is being pursued through the controlled corrosion of stainless steel wool, or the deposition of nickel dendrites on the existing stainless steel matrix material. They have also derived a model from a continuity equation that uses empirically determined capture cross section values. This enables the prediction of high gradient magnetic separator performance for a variety of materials and applications. The model can be used to optimize the capture cross section and thus increase the capture efficiency

  19. Magnetic Separation for Nuclear Material Detection and Surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Worl, L.A.; Devlin, D.; Hill, D.; Padilla, D.; Prenger, F.C.

    1998-08-01

    A high performance superconducting magnet is being developed for particle retrieval from field collected samples. Results show that maximum separation effectiveness is obtained when the matrix fiber diameter approaches the diameter of the particles to be captured. Experimentally, the authors obtained a single particle capture limit with 0.8{micro}m PuO{sub 2} particles with dodecane as a carrier fluid. The development of new matrix materials is being pursued through the controlled corrosion of stainless steel wool, or the deposition of nickel dendrites on the existing stainless steel matrix material. They have also derived a model from a continuity equation that uses empirically determined capture cross section values. This enables the prediction of high gradient magnetic separator performance for a variety of materials and applications. The model can be used to optimize the capture cross section and thus increase the capture efficiency.

  20. Theoretical Assessment of Technological Potential of Magnetic and Electrical Separation

    OpenAIRE

    Karmazin, V. V.

    1997-01-01

    Magnetic, electrical an combined methods of mineral beneficiation are widely used in various branches of mining industry. These processes have significant economic and ecological advantages in those areas where they can be applied technologically. It is thus necessary to analyse technological possibilities and areas of potential applications. Different designs of the separators must also be considered. Such an attempt is being done in this article based on the assessment of the level of diffe...

  1. Highly Sensitive and Rapid Detection of Pseudomonas aeruginosa Based on Magnetic Enrichment and Magnetic Separation

    OpenAIRE

    Tang, Yongjun; Zou, Jun; Chao MA; Ali, Zeeshan; Li, Zhiyang; LI, Xiaolong; Ma, Ninging; Mou, Xianbo; Deng, Yan; Zhang, Liming(Physics Department, Syracuse University, Syracuse, NY 13244-1130, USA); Li, Kai; Lu, GuangMing; Yang, Haowen; He, Nongyue

    2013-01-01

    A method for highly sensitive and rapid detection of Pseudomonas aeruginosa, based on magnetic enrichment and magnetic separation, is described in this paper. The magnetic nanoparticles (MNPs) were applied to adsorb genome DNA after the sample was lysed. The DNA binding MNPs were directly subjected to polymerase chain reaction (PCR) to amplify gyrB specific sequence of Pseudomonas aeruginosa. The biotin labeled PCR products were detected by chemiluminescence when they were successively incuba...

  2. Characterization of steel grit recovered from ornamental rocks waste by magnetic separation

    International Nuclear Information System (INIS)

    The aim of this work is characterization of steel grit recovered from ornamental rock waste by magnetic separation. The magnetic separation was realized in three steps: first, using a high intensity wet magnetic separator, which used only the remaining magnetic field of equipment. In the second step, the magnetic material obtained in the first phase was subjected to a new manual magnetic separation using rare earth magnets. In a third step, magnetic material obtained with rare earth magnets was subjected to manual magnetic separation using ferrite magnets. After the magnetic separation, the material was sent to characterization which was obtained by chemical analysis, scanning electron microscopy, X-ray diffraction and size analysis. The size analysis showed that the concentrate range from 0,5 to 563,67 μm with 4 wt.% over 100 μm and content metallic iron of 93 wt%. (author)

  3. Radiolysis and hydrolysis of magnetically assisted chemical separation particles

    Energy Technology Data Exchange (ETDEWEB)

    Buchholz, B.A.; Nunez, L.; Vandegrift, G.F.

    1995-05-01

    The magnetically assisted chemical separation (MACS) process is designed to separate transuranic (TRU) elements out of high-level waste (HLW) or TRU waste. Magnetic microparticles (1--25 {mu}m) were coated with octyl (phenyl)N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) dissolved in tributyl phosphate (TBP) and tested for removing TRU elements from acidic nitrate solutions. The particles were contacted with nitric acid solutions and Hanford plutonium finishing plant (PFP) simulant, irradiated with a high intensity {sup 60}Co {gamma}-ray source, and evaluated for effectiveness in removing TRU elements from 2m HNO{sub 3} solutions. The resistance of the coatings and magnetic cores to radiolytic damage and hydrolytic degradation was investigated by irradiating samples of particles suspended in a variety of solutions with doses of up to 5 Mrad. Transmission electron microscopy (TEM), magnetic susceptibility measurements, and physical observations of the particles and suspension solutions were used to assess physical changes to the particles. Processes that affect the surface of the particles dramatically alter the binding sites for TRU in solution. Hydrolysis played a larger role than radiolysis in the degradation of the extraction capacity of the particles.

  4. Development of magnetic separator for deironing of paint industrial stock

    Energy Technology Data Exchange (ETDEWEB)

    Bohm, J.; Csoke, B.; Antal, G. [Univ. of Miskolc (Hungary). Dept. of Process Engineering

    1995-12-31

    From the waste material of the production of aluminum foil aluminum pigment is produced for the paint industry by grinding it in white spirit. During grinding 1--2% iron impurity gets into the product, weakening its quality, from the war of the mill armor and the grinding bodies and from the contamination of the raw material. For deironing the product, a stage-operated electrically induced magnetic filter separator was developed and put into operation. The separator was sited in an explosive environment and therefore required a special design and safety system. The paper describes the results of the development work, the device that was developed, the safety system as well as the results of and experiences with the operation of the separator.

  5. Loss separation for dynamic hysteresis in magnetic thin films

    CERN Document Server

    Colaiori, F; Zapperi, S; Colaiori, Francesca; Durin, Gianfranco; Zapperi, Stefano

    2006-01-01

    We develop a theory for dynamic hysteresis in ferromagnetic thin films, on the basis of the phenomenological principle of loss separation. We observe that, remarkably, the theory of loss separation, originally derived for bulk metallic materials, is applicable to disordered magnetic systems under fairly general conditions regardless of the particular damping mechanism. We confirm our theory both by numerical simulations of a driven random--field Ising model, and by re--examining several experimental data reported in the literature on dynamic hysteresis in thin films. All the experiments examined and the simulations find a natural interpretation in terms of loss separation. The power losses dependence on the driving field rate predicted by our theory fits satisfactorily all the data in the entire frequency range, thus reconciling the apparent lack of universality observed in different materials.

  6. Magnetically separable titania-coated nickel ferrite photocatalyst

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Yun Seup; Park, Seung Bin; Kang, Duk-Won

    2004-08-15

    A magnetically separable photocatalyst was prepared by a continuous multi-step spray pyrolysis process. In the first step, nickel ferrite core particles were prepared by an ultrasonic spray pyrolysis. In the second step, tetraethyl orthosilicate (TEOS) and titanium isopropoxide (TTIP) were sequentially injected and coated on the surface of the core particles. The sequentially coated layers were decomposed to form silica and titania layers in a final furnace reactor. The titania-silica layered particles displayed higher photoactivity than particles coated only with titania and titania-silica mixture-coated particles. The photoactivity of the titania-silica layered particles remained unchanged after magnetic separation and washing. This confirms that the adhesion between the core particles and the coated layer is strong enough to withstand vigorous mixing. It also implies that the formation of free particles of silica or titania is negligible in the second reactor. The strong adhesion between the coated layer and the nickel ferrite core is attributed to the features of the multi-step process, wherein the core particles are exposed to high temperate in the second reactor for only a few seconds and transformation of the core particles into non-magnetic particles is prohibited.

  7. Magnetically separable titania-coated nickel ferrite photocatalyst

    International Nuclear Information System (INIS)

    A magnetically separable photocatalyst was prepared by a continuous multi-step spray pyrolysis process. In the first step, nickel ferrite core particles were prepared by an ultrasonic spray pyrolysis. In the second step, tetraethyl orthosilicate (TEOS) and titanium isopropoxide (TTIP) were sequentially injected and coated on the surface of the core particles. The sequentially coated layers were decomposed to form silica and titania layers in a final furnace reactor. The titania-silica layered particles displayed higher photoactivity than particles coated only with titania and titania-silica mixture-coated particles. The photoactivity of the titania-silica layered particles remained unchanged after magnetic separation and washing. This confirms that the adhesion between the core particles and the coated layer is strong enough to withstand vigorous mixing. It also implies that the formation of free particles of silica or titania is negligible in the second reactor. The strong adhesion between the coated layer and the nickel ferrite core is attributed to the features of the multi-step process, wherein the core particles are exposed to high temperate in the second reactor for only a few seconds and transformation of the core particles into non-magnetic particles is prohibited

  8. Characterization of a Prototype Compact High Gradient Magnetic Separator Device for Blood Detoxification.

    Czech Academy of Sciences Publication Activity Database

    Chen, H.; Kaminski, M. D.; Stepp, Patricia Caviness; Holtzman, S.; Rosengart, A. J.

    2009-01-01

    Ro?. 44, ?. 9 (2009), s. 1954-1969. ISSN 0149-6395 Institutional research plan: CEZ:AV0Z40550506 Keywords : magnetic separation * magnetic separator * detoxification * nanotechnology Subject RIV: CE - Biochemistry Impact factor: 1.028, year: 2009

  9. PER - CONCENTRATION OF IRON ORE SLIME IN MAGNETIC SEPARATOR

    Directory of Open Access Journals (Sweden)

    Dr. Nirlipta Nayak

    2015-08-01

    Full Text Available Indian iron ore is generally friable in nature that results in generation of significant quantity of fines (around 35% during mining and processing in the country. The ratio of lumps to fines produced in the country is 2:3. During washing and sizing of the ore, slimes with less than 0.21 mm size are generated and discarded into the tailing pond. It is estimated that around 10 million tons of slimes are being generated in every year during the processing of hematite ore and lost as tailings containing around 48 - 62% of Fe. The slime sample collected from Barsua assaying 54% Fe, 8.3% SiO2 & 11.08% Al2O3 was studied for pre concentration of iron values adopting gravity techniques followed by magnetic separa tion. The results indicated that Magnetic separation is a better pre concentration technique compared to gravity.

  10. Plasma separation process: Magnet move to Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    This is the final report on the series of operations which culminated with the delivery of the Plasma Separation Process prototype magnet system (PMS) to Building K1432 at Oak Ridge National Laboratory (ORNL). This procedure included real time monitoring of the cold mass support strut strain gauges and an in-cab rider to monitor the instrumentation and direct the driver. The primary technical consideration for these precautions was the possibility of low frequency resonant vibration of the cold mass when excited by symmetrical rough road conditions at specific speeds causing excess stress levels in the support struts and consequent strut failure. A secondary consideration was the possibility of high acceleration loads due to sudden stops, severe road conditions, of impacts. The procedure for moving and transportation to ORNL included requirements for real time continuous monitoring of the eight strut stain gauges and three external accelerometers. Because the strain gauges had not been used since the original magnet cooldown, it was planned to verify their integrity during magnet warmup. The measurements made from the strut strain gauges resulted in stress values that were physically impossible. It was concluded that further evaluation was necessary to verify the usefulness of these gauges and whether they might be faulty. This was accomplished during the removal of the magnet from the building. 6 figs., 1 tab

  11. On-chip Magnetic Separation and Cell Encapsulation in Droplets

    Science.gov (United States)

    Chen, A.; Byvank, T.; Bharde, A.; Miller, B. L.; Chalmers, J. J.; Sooryakumar, R.; Chang, W.-J.; Bashir, R.

    2012-02-01

    The demand for high-throughput single cell assays is gaining importance because of the heterogeneity of many cell suspensions, even after significant initial sorting. These suspensions may display cell-to-cell variability at the gene expression level that could impact single cell functional genomics, cancer, stem-cell research and drug screening. The on-chip monitoring of individual cells in an isolated environment could prevent cross-contamination, provide high recovery yield and ability to study biological traits at a single cell level These advantages of on-chip biological experiments contrast to conventional methods, which require bulk samples that provide only averaged information on cell metabolism. We report on a device that integrates microfluidic technology with a magnetic tweezers array to combine the functionality of separation and encapsulation of objects such as immunomagnetically labeled cells or magnetic beads into pico-liter droplets on the same chip. The ability to control the separation throughput that is independent of the hydrodynamic droplet generation rate allows the encapsulation efficiency to be optimized. The device can potentially be integrated with on-chip labeling and/or bio-detection to become a powerful single-cell analysis device.

  12. Theoretical analysis of a new, efficient microfluidic magnetic bead separator based on magnetic structures on multiple length scales

    DEFF Research Database (Denmark)

    Smistrup, Kristian; Bu, Minqiang; Wolff, Anders; Bruus, Henrik; Hansen, Mikkel Fougt

    2008-01-01

    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 lon...

  13. An open gradient magnetic separator assembled using NdFeB magnets for a use of fine particles remover

    International Nuclear Information System (INIS)

    A drum type magnetic separator was designed and optimized by computer simulation. The separator consisted of rotating outer shell of drum, magnetic flux generator drum which was assembled with numbers of disk type magnet holders, and drum axis around which the magnet holders were fixed. NdFeB magnet blocks were inserted into the disks, and the disks were assembled layer by layer along the drum axis. Magnetic circuits of the separator were simulated on the basis of highest magnetic strength, least cost, and high yield of separation by using a vector field S/W employing the opera-2D program. The separator proved a separation yield of 95% in removing fine iron-base particles, and installed at hot rolling mill of Pohang iron and steel co. in Korea. (orig.)

  14. Correlations, spin-charge separation, and magnetic anisotropy

    Science.gov (United States)

    Skomski, Ralph; Manchanda, Priyanka

    2015-03-01

    Much of the physics of condensed matter reflects electron-electron correlations. On an independent-electron level, correlations are described by a single Slater determinant with broken spin symmetry. This approach includes Hund's rule correlations as well the LSDA and LSDA+U approximations to density-functional theory (DFT). However, from Kondo and heavy-fermion systems it is known that the independent-electron approach fails to describe spin-charge separation in strongly correlated systems, necessitating the use of two or more Slater determinants. Using first-principle and model calculations, we show that spin-charge separation strongly affects the leading rare-earth anisotropy contribution in top-end permanent magnet materials such as Nd2Fe14B and SmCo5. Explicit correlation results are obtained for two limiting cases. First, we derive the density functional for tripositive rare-earth ions in a Bethe-type crystal field. The potential looks very different from the LSDA(+U) potentials, including gradient corrections. Second, we use a simple model to show that Kondo-type spin-charge separation yield a rare-earth anisotropy contribution absent in the independent-electron approach. This research is supported by DOE (DE-FG02-04ER46152).

  15. Monte Carlo study of phase separation in magnetic insulators

    CERN Document Server

    Murawski, Szymon; Paw?owski, Grzegorz; Robaszkiewicz, Stanis?aw

    2015-01-01

    In this work we focus on the study of phase separation in the zero-bandwidth extended Hubbard with nearest-neighbors intersite Ising-like magnetic interactions $J$ and on-site Coulomb interactions $U$. The system has been analyzed by means of Monte Carlo simulations (in the grand canonical ensemble) on two dimensional square lattice (with $N=L\\times L =400$ sites) and the results for $U/(4J)=2$ as a function of chemical potential and electron concentration have been obtained. Depending on the values of interaction parameters the system exhibits homogeneous (anti-)ferromagnetic (AF) or non-ordered (NO) phase as well as phase separation PS:AF/NO state. Transitions between homogeneous phases (i.e. AF-NO transitions) can be of first or second order and the tricritical point is also present on the phase diagrams. The electron compressibility $K$ is an indicator of the phase separation and that quantity is of particular interest of this paper.

  16. Thorium-uranium processing with gravity, magnetic and electrical separation in zarigan ore deposit

    International Nuclear Information System (INIS)

    Because of low grade of thorium and uranium in the Zarigan mineral deposit, the pre-concentration operation prior to leaching is necessary. From X-ray diffraction analysis results, it was clear that this ore has large amount of other minerals such as Feldespat, Quartz, Hematite, Titanomagnetite, and rare earths. In this paper the thorium enhancement grade in Zarigan deposit by using gravity, magnetic and electrical separations methods is reported. The output of a Jaw crusher was ground to 85 micron by using ball mill. Then about 95% of SiO2 was separated by using shaking table separation. The heavy concentrate of shaking table was processed by a high intensity magnetic separator and then the magnetic concentrate separated by a low intensity magnetic separator. Finally, the non magnetic concentrate of low magnetic separator was processed with the electrical separation. The grades of thorium and uranium in the non magnetic concentrate of low magnetic separator were increased to 4000 and 5000 ppm, respectively where only 15% of the initial feed (ore) was transferred to this concentrate. Therefore, this resulted in a decrease of acid consumption in the leaching processes and the efficiency enhancement of the process. The pre-treatment circuit of this ore was designed as Jaw crusher/ball mill/shaking table/high-magnetic separator/low-magnetic separator/electrical separator, respectively.

  17. Fundamental study on magnetic separation of aquatic organisms for preservation of marine ecosystem

    International Nuclear Information System (INIS)

    Recently, destruction and disturbance of marine ecosystem have been caused by changes in global environment and transplants of farmed fishes and shellfishes. To solve the problems, water treatment techniques to kill or to remove aquatic organisms are necessary. In this study, application of magnetic separation for removal of the aquatic organisms was examined in order to establish the process with high-speed, compact device and low environmental load. Techniques of magnetic seeding and magnetic separation using superconducting magnet are important for high-speed processing of aquatic organisms. Magnetic seeding is to adhere separating object to the surface of ferromagnetic particles, and magnetic separation is to remove aquatic organisms with magnetic force. First, we confirmed the possibility of magnetic seeding of aquatic organisms, and then interaction between aquatic organisms and ferromagnetic particles was examined. Next, for practical application of magnetic separation system using superconducting magnet for removal of aquatic organisms, particle trajectories were simulated and magnetic separation experiment using superconducting magnet was performed in order to design magnetic separation system to achieve high separation efficiency.

  18. Magnetic separation - Advanced nanotechnology for future nuclear fuel recycle

    International Nuclear Information System (INIS)

    The unique properties of magnetic nanoparticles (MNPs), such as their extremely small size and high surface area to volume ratio, provide better kinetics for the adsorption of metal ions from aqueous solutions. In this work, we demonstrated the separation of minor actinides using complex conjugates of MNPs with diethylenetriamine-pentaacetic acid (DTPA) chelator. The sorption results show the strong affinity of DTPA towards Am (III) and Pu (IV) by extracting 97% and 80% of actinides, respectively. It is shown that the extraction process is highly dependent on the pH of the solution. If these long-term heat generating actinides can be efficiently removed from the used fuel raffinates, the volume of material that can be placed in a given amount of repository space can be significantly increased. (authors)

  19. Magnetic separation - Advanced nanotechnology for future nuclear fuel recycle

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, M.; Zhang, H.; Qiang, Y. [Department of Physics and Environmental Science, University of Idaho, Moscow, ID 83844 (United States); Martin, L.; Todd, T. [Idaho National Laboratory, Idaho Falls, ID 83415 (United States)

    2013-07-01

    The unique properties of magnetic nanoparticles (MNPs), such as their extremely small size and high surface area to volume ratio, provide better kinetics for the adsorption of metal ions from aqueous solutions. In this work, we demonstrated the separation of minor actinides using complex conjugates of MNPs with diethylenetriamine-pentaacetic acid (DTPA) chelator. The sorption results show the strong affinity of DTPA towards Am (III) and Pu (IV) by extracting 97% and 80% of actinides, respectively. It is shown that the extraction process is highly dependent on the pH of the solution. If these long-term heat generating actinides can be efficiently removed from the used fuel raffinates, the volume of material that can be placed in a given amount of repository space can be significantly increased. (authors)

  20. Titania deposited on soft magnetic activated carbon as a magnetically separable photocatalyst with enhanced activity

    International Nuclear Information System (INIS)

    Magnetically separable composite photocatalysts, TiO2 deposited on soft magnetic ferrite activated carbon (TFAC), were prepared by sol-gel and dip-coating technique. The prepared composites were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectra (FTIR), optical absorption spectroscopy, vibrating sample magnetometer (VSM) and nitrogen adsorption. These photocatalysts exhibited enhanced photocatalytic activity compared to Degussa P25 for the degradation of methyl orange (MO) in aqueous solution. The kinetics of MO degradation was well fitted to the Langmuir-Hinshelwood model. The samples showed good magnetic response and could be completely recovered by an external magnet. Furthermore, the photocatalysts could maintain high photocatalytic activity after five cycles, and the degradation rate of MO was still close to 90%.

  1. Tracing magnetic separators and their dependence on IMF clock angle in global magnetospheric simulations

    CERN Document Server

    Komar, C M; Dorelli, J C; Glocer, A; Kuznetsova, M M

    2013-01-01

    A new, efficient, and highly accurate method for tracing magnetic separators in global magnetospheric simulations with arbitrary clock angle is presented. The technique is to begin at a magnetic null and iteratively march along the separator by finding where four magnetic topologies meet on a spherical surface. The technique is verified using exact solutions for separators resulting from an analytic magnetic field model that superposes dipolar and uniform magnetic fields. Global resistive magnetohydrodynamic simulations are performed using the three-dimensional BATS-R-US code with a uniform resistivity, in eight distinct simulations with interplanetary magnetic field (IMF) clock angles ranging from 0 (parallel) to 180 degrees (anti-parallel). Magnetic nulls and separators are found in the simulations, and it is shown that separators traced here are accurate for any clock angle, unlike the last closed field line on the Sun-Earth line that fails for southward IMF. Trends in magnetic null locations and the struc...

  2. Mercury removal from solution by superconducting magnetic separation with nanostructured magnetic adsorbents

    International Nuclear Information System (INIS)

    Recently, mercury Hg concentration in human blood increases due to expanding the global mercury contamination. Excess mercury bioaccumulation poses a significant health risk. In order to decrease mercury concentration in the environment and human blood, we have developed two different kinds of nanostructured magnetic adsorbents for mercury to apply them to superconducting magnetic separation instead of conventional filtration. One is magnetic beads (MBs) which have nanosize magnetite particles in the core and a lot of SH radicals on the surface to adsorb Hg ions effectively. MBs were developed mainly to remove mercury from human blood. The maximum amount of the adsorption for MBs is 6.3 mg/g in the solution in less than a minute. Dithiothreitol can easily remove mercury adsorbed to MBs, hence MBs can be reusable. The other is nanostructured magnetic activated carbon (MAC) which is activated carbon with mesopores and nanosize magnetite. The maximum amount of the adsorption for MAC is 38.3 mg/g in the solution. By heat-treatment mercury can be easily removed from MAC. We have studied superconducting magnetic separation using each adsorbent for mercury removal from solution.

  3. Mercury removal from solution by superconducting magnetic separation with nanostructured magnetic adsorbents

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, T., E-mail: okamoto-takayuki@ed.tmu.ac.jp [Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397 (Japan); Tachibana, S.; Miura, O. [Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397 (Japan); Takeuchi, M. [Komazawa Jin Clinic, 1-19-8 Komazawa, Setagayaku, Tokyo 154-0012 (Japan)

    2011-11-15

    Recently, mercury Hg concentration in human blood increases due to expanding the global mercury contamination. Excess mercury bioaccumulation poses a significant health risk. In order to decrease mercury concentration in the environment and human blood, we have developed two different kinds of nanostructured magnetic adsorbents for mercury to apply them to superconducting magnetic separation instead of conventional filtration. One is magnetic beads (MBs) which have nanosize magnetite particles in the core and a lot of SH radicals on the surface to adsorb Hg ions effectively. MBs were developed mainly to remove mercury from human blood. The maximum amount of the adsorption for MBs is 6.3 mg/g in the solution in less than a minute. Dithiothreitol can easily remove mercury adsorbed to MBs, hence MBs can be reusable. The other is nanostructured magnetic activated carbon (MAC) which is activated carbon with mesopores and nanosize magnetite. The maximum amount of the adsorption for MAC is 38.3 mg/g in the solution. By heat-treatment mercury can be easily removed from MAC. We have studied superconducting magnetic separation using each adsorbent for mercury removal from solution.

  4. Influences of separate position to radial direction between bulk superconductor and permanent magnetic ring about magnetic levitation and rotating characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Nagaya, S.; Komura, K.; Kashima, N.; Minami, M.; Kawashima, H.; Nara, Y.; Ishigaki, H

    2003-10-15

    The segmental structure of bulk superconductor will be needed designing ultra-large scale high temperature superconducting magnetic bearing for MWh class superconducting flywheel. The N-S poles of permanent magnetic ring assembly were arranged alternately to radial direction and the influences to magnetic levitation and rotating characteristics of the separate position of bulk superconductor to radial direction were tested. It was found when the separate position of bulk superconductor was coincided with the joint of the N-S poles of permanent magnets, both the magnetic levitation and the rotating characteristics were the same as the case of non-separate superconductor. When its position was the center of one side pole of permanent magnets, the levitation was the same as the case of non-separate superconductor, but the behavior of rotating characteristics changed and the loss increased as compared with the case of non-separate type.

  5. Collection of Ni-bearing material from electroless plating waste by magnetic separation with HTS bulk magnet

    Energy Technology Data Exchange (ETDEWEB)

    Oka, T., E-mail: okat@eng.niigata-u.ac.jp [Niigata University, 8050 Ikarashi-Ninocho, Nishi-ku, Niigata 950-2181 (Japan); Fukazawa, H.; Fukui, S.; Ogawa, J.; Sato, T.; Ooizumi, M. [Niigata University, 8050 Ikarashi-Ninocho, Nishi-ku, Niigata 950-2181 (Japan); Tsujimura, M. [Aichi Giken Co., 50-1 Takeshita, Hitotugi-cho, Kariya, Aichi 448-0003 (Japan); Yokoyama, K. [Ashikaga Institute of Technology, 268-1 Ohmae-cho, Ashikaga, Tochigi 326-8558 (Japan)

    2014-01-15

    Highlights: ? The magnetic separation for Ni compounds was conducted by HTS bulk magnet. ? The coarse Ni-sulfate crystals were formed from the Ni-phosphite precipitates. ? Ni-sulfate crystals was separated from the mixture of Ni-sulfate and Ni-phosphite compounds. -- Abstract: The magnetic separation experiment to collect the Ni compounds from the waste liquid of electroless plating processes was conducted in the open-gradient magnetic separation process with the high temperature superconducting bulk magnet system. The magnetic pole containing Gd-based bulk superconductors was activated to 3.45 T at 35 K in the static magnetic field of 5 T with use of a superconducting solenoid magnet. The coarse Ni-sulfate crystals were formed by adding the concentrated sulfuric acid to the Ni-phosphite precipitates which yielded from the plating waste liquid by controlling the temperature and the pH value. The open-gradient magnetic separation technique was employed to separate the Ni-sulfate crystals from the mixture of the Ni-sulfate and Ni-phosphite compounds by the difference between their magnetic properties. And we succeeded in collecting Ni-sulfate crystals preferentially to the Ni-phosphite by attracting them to the magnetic pole soon after the Ni-sulfate crystals began to grow.

  6. Large Scale Magnetic Separation of Solanum tuberosum Tuber Lectin from Potato Starch Waste Water

    Science.gov (United States)

    Safarik, Ivo; Horska, Katerina; Martinez, Lluis M.; Safarikova, Mirka

    2010-12-01

    A simple procedure for large scale isolation of Solanum tuberosum tuber lectin from potato starch industry waste water has been developed. The procedure employed magnetic chitosan microparticles as an affinity adsorbent. Magnetic separation was performed in a flow-through magnetic separation system. The adsorbed lectin was eluted with glycine/HCl buffer, pH 2.2. The specific activity of separated lectin increased approximately 27 times during the isolation process.

  7. Exploiting Size-Dependent Drag and Magnetic Forces forSize-Specific Separation of Magnetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Hunter B. Rogers

    2015-08-01

    Full Text Available Realizing the full potential of magnetic nanoparticles (MNPs in nanomedicinerequires the optimization of their physical and chemical properties. Elucidation of the effectsof these properties on clinical diagnostic or therapeutic properties, however, requires thesynthesis or purification of homogenous samples, which has proved to be difficult. Whileinitial simulations indicated that size-selective separation could be achieved by flowingmagnetic nanoparticles through a magnetic field, subsequent in vitro experiments wereunable to reproduce the predicted results. Magnetic field-flow fractionation, however, wasfound to be an effective method for the separation of polydisperse suspensions of iron oxidenanoparticles with diameters greater than 20 nm. While similar methods have been used toseparate magnetic nanoparticles before, no previous work has been done with magneticnanoparticles between 20 and 200 nm. Both transmission electron microscopy (TEM anddynamic light scattering (DLS analysis were used to confirm the size of the MNPs. Furtherdevelopment of this work could lead to MNPs with the narrow size distributions necessary fortheir in vitro and in vivo optimization.

  8. SUPERCONDUCTING MAGNET FOR 60 TONNE/HOUR MINERAL SEPARATOR WITH CLOSED CYCLE 4 KELVIN REFRIGERATION

    OpenAIRE

    Good, J.; White, K.

    1984-01-01

    Cryogenic Consultants Limited has constructed a superconducting magnet system for magnetic separation, with a three metre long dipole magnet cooled by a closed-cycle refrigerator. This paper considers the design and construction of the magnet system in relation to a theoretical expression for processing capacity.

  9. Rapid Characterization of Magnetic Separator Feed Stocks in Titanium Minerals Processing

    OpenAIRE

    Cavanough, G.; Holtham, P.N.

    2004-01-01

    Magnetic separation is widely used in the processing of titanium minerals. The expected mineral recoveries are assessed by performing laboratory magnetic separations of representative samples to determine the distribution of magnetic components. This is an inherently slow process performed on relatively small samples. This paper describes the development of an inductance based device to rapidly determine the mass distribution of the magnetic properties of a titanium mineral sample. The system...

  10. Magnetic separation of particles and cells in ferrofluid flow through a straight microchannel using two offset magnets

    International Nuclear Information System (INIS)

    The separation of particles and cells is critical in many chemical and biological applications. This work presents a simple idea for utilizing a pair of permanent magnets to continuously separate diamagnetic particles and cells in ferrofluid flow through a straight microchannel. The first magnet is placed close to the microchannel for focusing the particle mixture to a single stream without the use of a sheath flow. The second magnet, which is offset from the first magnet and placed farther from the channel, is to displace the aligned particles to dissimilar flow paths for a continuous sorting. This idea is first demonstrated through the separation of 3 ?m- and 10 ?m-diameter polystyrene particles, where the effects of flow speed and magnet distance are both examined. The experimental data are found to fit well with the predictions of an analytical model. Furthermore, a continuous separation of live yeast cells from 10 ?m polystyrene particles is implemented in the same device. - Highlights: We develop a simple diamagnetic particle and cell separation technique in ferrofluids. Two offset magnets are used to achieve a sheath-free continuous separation in a straight microchannel. The technique is demonstrated through the magnetic separation of polystyrene particles and yeast cells. The effects of ferrofluid speed and magnet-channel distance are examined on particle separation. The predictions from an analytical model agree with the experimental data quantitatively

  11. Application of high temperature superconductors to high-gradient magnetic separation

    International Nuclear Information System (INIS)

    High Gradient Magnetic Separation (HGMS) is a powerful technique which can be used to separate widely dispersed contaminants from a host material. This technology can separate magnetic solids from other solids, liquids or gases. As the name implies HGMS uses large magnetic field gradients to separate ferromagnetic and paramagnetic particles. HGMS separators usually consist of a high-field solenoid magnet, the bore of which contains a fine-structured, ferromagnetic matrix material. The matrix material locally distorts the magnetic field and creates large field gradients in the vicinity of the matrix elements. These elements then become trapping sites for magnetic particles and are the basis for the magnetic separation. In this paper the authors discuss the design and construction of a prototype HGMS unit using a magnet made with high temperature superconductors (HTS). The prototype consists of an outer vacuum vessel which contains the HTS solenoid magnet. The magnet is surrounded by a thermal radiation shield and multilayer insulation (MLI) blankets. The magnet, thermal shield and current leads all operate in a vacuum and are cooled by a cryocooler. High temperature superconducting current leads are used to reduce the heat leak from the ambient environment to the HTS magnet

  12. Theoretical analysis of a new, efficient microfluidic magnetic bead separator based on magnetic structures on multiple length scales

    DEFF Research Database (Denmark)

    Smistrup, Kristian; Bu, Minqiang

    2008-01-01

    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.

  13. Magnetic separation as a method to assist mineralogical characterization of rocks by X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Amanda Luzia da; Oliveira, Arno Heeren de; Fernandes, Maria Lourdes Souza, E-mail: amanda@igc.ufmg.br, E-mail: heeren@nuclear.ufmg.br, E-mail: amanda@igc.ufmg.br, E-mail: lurdesfernandes@ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horionte, MG (Brazil)

    2013-07-01

    The X-ray diffraction (XRD) corresponds to one of the main techniques for characterization of structures in crystalline materials widely used in the identification of minerals in samples of geological materials such as rocks. However, the large number of mineral phases present in a rock sample can generate excess peaks in the diffractogram, and it can promote overlapping peaks and induce erroneous identification. The purpose of this study was to perform magnetic separation of minerals from rock samples in order to enable the identification of the minerals by XRD. For this magnetic separation, two samples of rock were selected: a sample of high silica content and a sample with low silica content. The magnetic separation of minerals from each sample was performed using the magnetic separator isodynamic Frantz. Posteriorly, the fractions obtained in magnetic separations were analyzed by XRD. In the sample with high silica content, it was obtained a fraction where was identified the accessory mineral epidote, which had not been identified in the total sample diffractogram. In the sample with low silica content, the magnetic separation into several mineral fractions made possible to obtain diffraction patterns with fewer peaks and peaks with higher relative intensities, which allowed its mineralogical characterization. The results showed that the mineral separation by the magnetic separator Frantz made the identification of accessory minerals by XRD and the characterization of samples which have many mineral phases possible, which proves that magnetic separation by Frantz is a method which can assist analyses by XRD. (author)

  14. Conjugates of Actinide Chelator-Magnetic Nanoparticles for Used Fuel Separation Technology

    Energy Technology Data Exchange (ETDEWEB)

    Qiang, You; Paszczynski, Andrzej; Rao, Linfeng

    2011-10-30

    The actinide separation method using magnetic nanoparticles (MNPs) functionalized with actinide specific chelators utilizes the separation capability of ligand and the ease of magnetic separation. This separation method eliminated the need of large quantity organic solutions used in the liquid-liquid extraction process. The MNPs could also be recycled for repeated separation, thus this separation method greatly reduces the generation of secondary waste compared to traditional liquid extraction technology. The high diffusivity of MNPs and the large surface area also facilitate high efficiency of actinide sorption by the ligands. This method could help in solving the nuclear waste remediation problem.

  15. Magnetic separation in microfluidic systems using microfabricated electromagnets - Experiments and simulations

    DEFF Research Database (Denmark)

    Smistrup, Kristian; Hansen, Ole

    2005-01-01

    We present experiments and simulations of magnetic separation of magnetic beads in a microfluidic channel. The separation is obtained by microfabricated electromagnets. The results of our simulations using FEMLAB and Mathematica are compared with experimental results obtained using our own microfabricated systems. (c) 2005 Elsevier B.V. All rights reserved.

  16. Phase separation in cuprate superconductors: study of magnetic resonance

    International Nuclear Information System (INIS)

    Phase distribution processes in ceramics and crystals of cuprate superconductors of 1-2-3 type compounds are investigated by magnetic resonance and microwave spectroscopy methods. Magnetic resonance signals observed in these compounds after quenching are studied. Magnetic resonance signal intensity anticorrelates with the quantity of a superconducting phase in a sample. An intensive magnetic resonance signal occurs in cuprate superconductor 123 type samples after quenching in air at the temperature exceeding 1000 k and the superconducting phase disappears alsmost completely. During a shortterm annealing in the air at the temperatures exceeding 300 K the magnetic resonance signal disappears and the superconducting phase reconduction takes place. 17 refs.; 6 figs

  17. The electromagnetic design of a permanent magnet based separator

    CERN Document Server

    Nedelcu, S

    2002-01-01

    The aim of this work was to design a permanent magnet based device that can selectively transport paramagnetic particles. Using specialised electromagnetic design software various arrangements of permanent magnets have been investigated. Each test geometry had to be constructively simple and able to produce highly non-uniform magnetic fields before being considered further in any more detail. The main parameter to indicate that the test geometry might be a suitable device has been ascribed to the ratio eta between the highest (ON) and lowest (OFF) magnetic fields that were measured. A linear arrangement of permanent magnets has been considered first. This device produced a ratio eta approx 2. Further, the cylindrical and the tubular arrangements may be considered as substantial improvements over the first geometry. The OFF magnetic fields have been substantially reduced by the method of magnetic shielding. Intensive research and modelling has been spent on addressing the problem of finding the optimal geometr...

  18. Open gradient magnetic separation utilizing NbTi, Nb3Sn and Bi-2223 materials

    International Nuclear Information System (INIS)

    Superconducting magnets enable the magnetic separation of particles with small magnetic susceptibility. In this paper, we compare superconducting separator magnets made of Nb3Sn, NbTi and Bi-2223 materials. The separator system is used to determine the optimal conditions for separation of various slurries. The magnet should provide a high and nearly constant magnetic force density. These requirements are met with racetrack coils. Geometries consisting of one or two racetracks have been examined. In order to keep the material costs at a reasonable level, the volume of the magnet has been minimized taking into account the constraints set by the force and current densities. Sequential quadratic programming (SQP) was used in the optimization procedure. The force density has been calculated using an analytical two-dimensional model. The critical current density of the coil was obtained by solving the magnetic flux density from a three-dimensional model using the finite element method. We have compared magnetic force densities and wire lengths in magnets made of different materials. For magnets made of low-temperature superconductors, the optimized geometry consisted of two coils. For magnets made of high-temperature superconductors, the minimum volume was achieved by using only one coil. (author)

  19. Magnetite/CdTe magnetic-fluorescent composite nanosystem for magnetic separation and bio-imaging

    International Nuclear Information System (INIS)

    A new synthesis protocol is described to obtain a CdTe decorated magnetite bifunctional nanosystem via dodecylamine (DDA) as cross linker. High resolution transmission electron microscopy (HRTEM), energy-dispersive x-ray spectroscopy (EDAX), vibrating sample magnetometry (VSM), Fourier transform infrared spectroscopy (FTIR), diffuse reflectance spectroscopy (DRS) and fluorescence microscopy are used to characterize the constitution, size, composition and physical properties of these superparamagnetic-fluorescent nanoparticles. These CdTe decorated magnetite nanoparticles were then functionalized with anti-epidermal growth factor receptor (EGFR) antibody to specifically target cells expressing this receptor. The EGFR is a transmembrane glycoprotein and is expressed on tumor cells from different tissue origins including human leukemic cell line Molt-4 cells. The magnetite-CdTe composite nanosystem is shown to perform excellently for specific selection, magnetic separation and fluorescent detection of EGFR positive Molt-4 cells from a mixed population. Flow cytometry and confocal laser scanning microscopy results show that this composite nanosystem has great potential in antibody functionalized magnetic separation and imaging of cells using cell surface receptor antibody.

  20. In search of chiral magnetic effect: separating flow-driven background effects and quantifying anomaly-induced charge separations

    CERN Document Server

    Huang, Xu-Guang; Liao, Jinfeng

    2015-01-01

    We report our recent progress on the search of Chiral Magnetic Effect (CME) by developing new measurements as well as by hydrodynamic simulations of CME and background effects, with both approaches addressing the pressing issue of separating flow-driven background contributions and possible CME signal in current heavy ion collision measurements.

  1. Proposal for implanting a magnetic stable isotope separator

    International Nuclear Information System (INIS)

    The implantation of an electromagnetic isotope separator able to separate elements of mass from 20 to 250 a.m.u., with an enrichment factor from 10 to 200 times the initial concentration, depending on the elements, is proposed. The most suitable separator type for Brazilian CNEN, considering building installations and minimum conditions for the equipment facilities, the retinue chronogram, the infrastructure, and the personnel training for operation is defined. (M.C.K.)

  2. Separation and Focusing of Magnetic Beads for Agglutination Tests

    OpenAIRE

    Afshar Ghasemlouy, Rana

    2011-01-01

    Functional magnetic micro- and nanoparticles are used in bioanalytical applications as solid carriers for capture, transport and detection of biomolecules or magnetically labeled cells. Colloidal suspensions of such particles provide a large specific surface for chemical binding and therefore allow highly efficient interactions with target molecules in a sample solution. Controlled actuation and manipulation of these mobile substrates in the microflui...

  3. Purification of condenser water in thermal power station by superconducting magnetic separation

    International Nuclear Information System (INIS)

    Magnetic separation using cryo-cooled Nb-Ti superconducting magnet was applied for the purification of condenser water. Iron oxides in condenser water were effectively removed by superconducting magnetic separation. The effect of magnetic field strength and filter size was determined. 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 6 T 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 ?-Fe2O3 (hematite) and ?-Fe2O3 (maghemite). The higher magnetic field was applied up to 6 T, the more iron oxides were removed. As the wire diameter of magnetic filter decreased, the turbidity removal of the sample was enhanced.

  4. Magnetic properties and loss separation in iron-silicone-MnZn ferrite soft magnetic composites

    International Nuclear Information System (INIS)

    This paper investigates the magnetic and structural properties of iron-based soft magnetic composites coated with silicone-MnZn ferrite hybrid. The organic silicone resin was added to improve the flexibility of the insulated iron powder and causes better adhesion between particles to increase the mechanical properties. Scanning electron microscopy and distribution maps show that the iron particle surface is covered with a thin layer of silicone-MnZn ferrite. Silicone-MnZn ferrite coated samples have higher permeability when compared with the non-magnetic silicone resin coated compacts. The real part of permeability increases by 34.18% when compared with the silicone resin coated samples at 20 kHz. In this work, a formula for calculating the total loss component by loss separation method is presented and finally the different parts of total losses are calculated. The results show that the eddy current loss coefficient is close to each other for the silicone-MnZn ferrite, silicone resin and MnZn ferrite coated samples (0.007832 =1.4058) in comparison with other samples

  5. Highly Sensitive and Rapid Detection of Pseudomonas aeruginosa Based on Magnetic Enrichment and Magnetic Separation

    Directory of Open Access Journals (Sweden)

    Yongjun Tang, Jun Zou, Chao Ma, Zeeshan Ali, Zhiyang Li, Xiaolong Li, Ninging Ma, Xianbo Mou, Yan Deng, Liming Zhang, Kai Li, Guangming Lu, Haowen Yang, Nongyue He

    2013-01-01

    Full Text Available A method for highly sensitive and rapid detection of Pseudomonas aeruginosa, based on magnetic enrichment and magnetic separation, is described in this paper. The magnetic nanoparticles (MNPs were applied to adsorb genome DNA after the sample was lysed. The DNA binding MNPs were directly subjected to polymerase chain reaction (PCR to amplify gyrB specific sequence of Pseudomonas aeruginosa. The biotin labeled PCR products were detected by chemiluminescence when they were successively incubated with the probes-modified MNPs and alkaline phosphatase (ALP labeled streptavidin (SA. Agarose gel electrophoresis analyses approved the method of in situ PCR to be highly reliable. The factors which could affect the chemiluminiscence were studied in detail. The results showed that the MNPs of 400 nm in diameter are beneficial to the detection. The sequence length and the binding site of the probe with a target sequence have obvious effects on the detection. The optimal concentration of the probes, hybridization temperature and hybridization time were 10 ?M, 60 C and 60 mins, respectively. The method of in situ PCR based on MNPs can greatly improve the utilization rate of the DNA template ultimately enhancing the detection sensitivity. Experiment results proved that the primer and probe had high specificity, and Pseudomonas aeruginosa was successfully detected with detection limits as low as 10 cfu/mL by this method, while the detection of a single Pseudomonas aeruginosa can also be achieved.

  6. Magnetic separation of algae genetically modified for increased intracellular iron uptake

    International Nuclear Information System (INIS)

    Algae were investigated in the past as a potential source of biofuel and other useful chemical derivatives. Magnetic separation of algae by iron oxide nanoparticle binding to cells has been proposed by others for dewatering of cellular mass prior to lipid extraction. We have investigated feasibility of magnetic separation based on the presence of natural iron stores in the cell, such as the ferritin in Auxenochlorella protothecoides (A. protothecoides) strains. The A. protothecoides cell constructs were tested for inserted genes and for increased intracellular iron concentration by inductively coupled plasma atomic absorption (ICP–AA). They were grown in Sueoka’s modified high salt media with added vitamin B1 and increasing concentration of soluble iron compound (FeCl3 EDTA, from 1× to 8× compared to baseline). The cell magnetic separation conditions were tested using a thin rectangular flow channel pressed against interpolar gaps of a permanent magnet forming a separation system of a well-defined fluid flow and magnetic fringing field geometry (up to 2.2 T and 1000 T/m) dubbed “magnetic deposition microscopy”, or MDM. The presence of magnetic cells in suspension was detected by formation of characteristic deposition bands at the edges of the magnet interpolar gaps, amenable to optical scanning and microscopic examination. The results demonstrated increasing cellular Fe uptake with increasing Fe concentration in the culture media in wild type strain and in selected genetically-modified constructs, leading to magnetic separation without magnetic particle binding. The throughput in this study is not sufficient for an economical scale harvest. - Highlights: • Auxenochlorella protothecoides algae were genetically modified for biofuel production. • Algal iron metabolism was sufficient for their label-less magnetic separation. • High magnetic field and low flow required make the separation scale-up uneconomical

  7. Collection of Ni-bearing material from electroless plating waste by magnetic separation with HTS bulk magnet

    Science.gov (United States)

    Oka, T.; Fukazawa, H.; Fukui, S.; Ogawa, J.; Sato, T.; Ooizumi, M.; Tsujimura, M.; Yokoyama, K.

    2014-01-01

    The magnetic separation experiment to collect the Ni compounds from the waste liquid of electroless plating processes was conducted in the open-gradient magnetic separation process with the high temperature superconducting bulk magnet system. The magnetic pole containing Gd-based bulk superconductors was activated to 3.45 T at 35 K in the static magnetic field of 5 T with use of a superconducting solenoid magnet. The coarse Ni-sulfate crystals were formed by adding the concentrated sulfuric acid to the Ni-phosphite precipitates which yielded from the plating waste liquid by controlling the temperature and the pH value. The open-gradient magnetic separation technique was employed to separate the Ni-sulfate crystals from the mixture of the Ni-sulfate and Ni-phosphite compounds by the difference between their magnetic properties. And we succeeded in collecting Ni-sulfate crystals preferentially to the Ni-phosphite by attracting them to the magnetic pole soon after the Ni-sulfate crystals began to grow.

  8. Integrated acoustic and magnetic separation in microfluidic channels

    DEFF Research Database (Denmark)

    Adams, Jonathan; Thevoz, Patrick; Bruus, Henrik; Soh, H. Tom

    2009-01-01

    With a growing number of cell-based biotechnological applications, there is a need for particle separation systems capable of multiparameter separations at high purity and throughput, beyond what is presently offered by traditional methods including fluorescence activated cell sorting and column-......(8) particles/hr. (C) 2009 American Institute of Physics. [doi:10.1063/1.3275577]...

  9. Theoretical analysis of a simple yet efficient portable magnetic separator design for separation of magnetic nano/micro-carriers from human blood flow

    International Nuclear Information System (INIS)

    A technology that could physically remove substances from the blood such as biological, chemical, or radiological toxins could dramatically improve treatment of disease. One method in development proposes to use magnetic-polymer spheres to selectively bind toxins and remove them by magnetic filtration. Although magnetic filtration is a developed technology, the clinical boundary conditions described here require a new filter design. We investigated the removal of toxin-bound magnetic carriers from the blood stream using 2-D FEMLAB simulations. The magnetic separator consisted of a permanent magnet with parallel ferromagnetic prisms on the faces and in contact with a straight tube carrying the magnetic-polymer spheres in suspension. We varied the following parameters: blood flow velocity, the size, and number of ferromagnetic prisms, and the ferromagnetic material in both prisms and magnets. The capture efficiency reached maximum values when the depth of the prisms equaled the diameter of the tubing and the saturation magnetization of the prism material equaled twice that of the magnet. With this design a piece of 2 mm (diameter) tube carrying the fluid resulted in 95% capture of 2.0 ?m magnetic-polymer spheres at 10 cm/s flow velocity

  10. Cleaning of liquid radioactive waste by the methods of ozonization and magnetic separation

    International Nuclear Information System (INIS)

    The possibility for purification of liquid radioactive wastes (LRW) from organic compounds by the methods of ozonization and magnetic separation is studied. It is shown that addition of a finely divided ferromagnetic substance into LRW and subsequent filtration through a magnetic filter is an effective method for removal of emulsified organic compounds. The dissolved organic compounds are destroyed by ozonization. Some characteristics of the ozonization and magnetic separation processes are determined. The composition of the products of reactions between ozone and organic compounds is defined. The behavior of 137Cs in the process of magnetic separation is investigated. A feasibility of very good cleaning of LRW from emulsified organic compounds by means of successive application of the methods of magnetic separation and ozonization is confirmed

  11. Fluctuations of the Solitary Bubble at the Separation from the Air Cavity, Compressed by the Magnetic Field in Magnetic Liquid

    OpenAIRE

    Boev, M.L.; Polunin, V.M.; O.V. Lobova; Shabanova, I.A.; Chervjakov, L.M.; A.N. Ryapolov

    2013-01-01

    In the article, on the basis of the concept of "display" of geometry of a free surface of the "low-magnetic" environment by the topography of isolines of the module of intensity of a magnetic field, it is studied a form of a free surface of magnetic fluid in a static condition at the initial stage of rapprochement of a ring magnet with a surface of a column of magnetic fluid in a tube and at a stage of pressing of a cavity to a bottom. It is shown that the separation of bubbles from an air ca...

  12. Colossal magnetoresistance and phase separation in magnetic semiconductors

    CERN Document Server

    Nagaev, Eduard L

    2002-01-01

    Colossal magnetoresistance materials, to which manganites and conventional ferromagnetic semiconductors belong, draw great attention because of their intriguing physical properties and the excellent prospects for their practical applications in electronic devices. In addition, magnetic semiconductors are basic materials for high-temperature conductors, and it is impossible to construct a theory of the latter without elucidating properties of the former.This book presents theoretical and experimental results on manganites and conventional magnetic semiconductors, with emphasis on the former. It

  13. Large Scale Magnetic Separation of Solanum tuberosum Tuber Lectin from Potato Starch Waste Water.

    Czech Academy of Sciences Publication Activity Database

    afa?k, Ivo; Horsk, Kate?ina; Martinez, L. M.; afa?kov, Miroslava

    Melville : American institute of physics, 2010 - (Hfeli, U.; Schtt, W.; Zborowski, M.), s. 146-151 ISBN 978-0-7354-0866-1. ISSN 0094-243X. - (AIP Conference Proceedings. 1311). [International Conference on the Scientific and Clinical Applications of Magnetic Carriers /8./. Rostock (DE), 25.05.2010-29.05.2010] Institutional research plan: CEZ:AV0Z60870520 Keywords : drug delivery * magnetic microspheres and ferrofluids * magnetic nanospheres * molecular biology * stem cell separation * starch production * potato waste water * magnetic separation * chitosan * lectin * Solanum tuberosum Subject RIV: EH - Ecology, Behaviour

  14. Detection of carcinoembryonic antigen using functional magnetic and fluorescent nanoparticles in magnetic separators

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, H. Y., E-mail: annetsai@csmu.edu.tw [Chung Shan Medical University, Department of Applied Chemistry (China); Chang, C. Y.; Li, Y. C.; Chu, W. C.; Viswanathan, K.; Bor Fuh, C., E-mail: cbfuh@ncnu.edu.tw [National Chi Nan University, Department of Applied Chemistry (China)

    2011-06-15

    We combined a sandwich immunoassay, anti-CEA/CEA/anti-CEA, with functional magnetic ({approx}80 nm) and fluorescent ({approx}180 nm) nanoparticles in magnetic separators to demonstrate a detection method for carcinoembryonic antigen (CEA). Determination of CEA in serum can be used in clinical diagnosis and monitoring of tumor-related diseases. The CEA concentrations in samples were deduced and determined based on the reference plot using the measured fluorescent intensity of sandwich nanoparticles from the sample. The linear range of CEA detection was from 18 ng/mL to 1.8 pg/mL. The detection limit of CEA was 1.8 pg/mL. In comparison with most other detection methods, this method had advantages of lower detection limit and wider linear range. The recovery was higher than 94%. The CEA concentrations of two serum samples were determined to be 9.0 and 55 ng/mL, which differed by 6.7% (9.6 ng/mL) and 9.1% (50 ng/mL) from the measurements of enzyme-linked immunosorbent assay (ELISA), respectively. The analysis time can be reduced to one third of ELISA. This method has good potential for other biomarker detections and biochemical applications.

  15. Iso-geometric shape optimization of magnetic density separators

    DEFF Research Database (Denmark)

    Dang Manh, Nguyen; Evgrafov, Anton; Gravesen, Jens; Lahaye, Domenico

    2014-01-01

    covers with B-splines and defines a cost functional that measures the non-uniformity of the magnetic field in an area above the poles. The authors apply an iso-geometric shape optimization procedure, which allows us to accurately represent, analyze and optimize the geometry using only a few design...

  16. Immunomagnetic separation of Salmonella cells using newly designed magnetic carrriers.

    Czech Academy of Sciences Publication Activity Database

    Rittich, B.; panov, A.; Su?ikov, J.; trumcov, S.; Lenfeld, Ji?; Hork, Daniel

    Frankfurt am Main : Dechema e. V. Society for Chemical Engineering and Biotechnology, 2002. s. P28. [International Symposium on the Separation of Proteins, Peptides and Polynucleotides /22./. 10.11.2002-13.11.2002, Heidelberg] R&D Projects: GA AV ?R KSK4055109 Keywords : Salmonella cells Subject RIV: CC - Organic Chemistry

  17. High-gradient magnetic affinity separation of trypsin from porcine pancreatin

    DEFF Research Database (Denmark)

    Hubbuch, Jrgen; Thomas, Owen R. T.

    2002-01-01

    submicron-sized magnetic supports are presented. These support materials exhibit unique features, which facilitate their large-scale processing using high magnetic field gradients, namely sufficiently high magnetization, a relatively narrow particle size distribution and ideal superparamagnetism. Following...... increased scale using a high-gradient magnetic separation system to capture loaded benzamidine-linked adsorbents following batch adsorption. With the aid of a simple recycle loop over 80% of the initially adsorbed trypsin was recovered in-line with an overall purification factor of approximate to3.5.......We introduce a robust and scale-flexible approach to macromolecule purification employing tailor-made magnetic adsorbents and high-gradient magnetic separation technology adapted from the mineral processing industries. Detailed procedures for the synthesis of large quantities of low-cost defined...

  18. Fluctuations of the Solitary Bubble at the Separation from the Air Cavity, Compressed by the Magnetic Field in Magnetic Liquid

    Directory of Open Access Journals (Sweden)

    M.L. Boev

    2013-12-01

    Full Text Available In the article, on the basis of the concept of "display" of geometry of a free surface of the "low-magnetic" environment by the topography of isolines of the module of intensity of a magnetic field, it is studied a form of a free surface of magnetic fluid in a static condition at the initial stage of rapprochement of a ring magnet with a surface of a column of magnetic fluid in a tube and at a stage of pressing of a cavity to a bottom. It is shown that the separation of bubbles from an air cavity occurs in close proximity to the plane of symmetry of a ring magnet on its axis. It is described the method and experimental installation for studying the possibility of electromagnetic indication of sizes of the air bubbles, being in magnetic fluid. It is discussed the results of experimental research on process of a separation of solitary air bubble from a cavity, contained in magnetic fluid and squeezed by ponderomotive forces of a magnetic field which are of interest for creation of essentially new technique of the dosed supply of small amount of gas in the reactor.

  19. ELECTRON TRANSPORT IN CORONAL LOOPS: THE INFLUENCE OF THE EXPONENTIAL SEPARATION OF MAGNETIC FIELD LINES

    International Nuclear Information System (INIS)

    Observations by the TRACE spacecraft have shown that coronal emission in the extreme ultraviolet is characterized by filamentary structures within coronal loops, with transverse sizes close to the instrumental resolution. Starting from the observed filament widths and using the concepts of braided magnetic fields, an estimate of the turbulence level in the coronal loops can be obtained. Magnetic turbulence in the presence of a background magnetic field can be strongly anisotropic, and such anisotropy influences the separation of magnetic field lines, as well as the magnetic field line diffusion coefficient. Careful computations of the magnetic field line diffusion coefficient Dm and of the rate of exponential separation of magnetic field lines h, also allowing for the possibility of anisotropic magnetic turbulence, enable computation of the effective perpendicular diffusion coefficient for electrons. When compared with observations this yields magnetic turbulence levels on the order of ?B/B 0 = 0.05-0.7, which are larger than previous estimates. These values of the magnetic fluctuation level support the idea that magnetic turbulence can contribute to coronal heating by means of MHD turbulence dissipation. It is also found that field line transport is not governed by the quasilinear regime, but by a nonlinear regime which includes an intermediate and the percolation regimes.

  20. Magnetic separation of algae genetically modified for increased intracellular iron uptake

    Science.gov (United States)

    Buck, Amy; Moore, Lee R.; Lane, Christopher D.; Kumar, Anil; Stroff, Clayton; White, Nicolas; Xue, Wei; Chalmers, Jeffrey J.; Zborowski, Maciej

    2015-04-01

    Algae were investigated in the past as a potential source of biofuel and other useful chemical derivatives. Magnetic separation of algae by iron oxide nanoparticle binding to cells has been proposed by others for dewatering of cellular mass prior to lipid extraction. We have investigated feasibility of magnetic separation based on the presence of natural iron stores in the cell, such as the ferritin in Auxenochlorella protothecoides (A. protothecoides) strains. The A. protothecoides cell constructs were tested for inserted genes and for increased intracellular iron concentration by inductively coupled plasma atomic absorption (ICP-AA). They were grown in Sueoka's modified high salt media with added vitamin B1 and increasing concentration of soluble iron compound (FeCl3 EDTA, from 1 to 8 compared to baseline). The cell magnetic separation conditions were tested using a thin rectangular flow channel pressed against interpolar gaps of a permanent magnet forming a separation system of a well-defined fluid flow and magnetic fringing field geometry (up to 2.2 T and 1000 T/m) dubbed "magnetic deposition microscopy", or MDM. The presence of magnetic cells in suspension was detected by formation of characteristic deposition bands at the edges of the magnet interpolar gaps, amenable to optical scanning and microscopic examination. The results demonstrated increasing cellular Fe uptake with increasing Fe concentration in the culture media in wild type strain and in selected genetically-modified constructs, leading to magnetic separation without magnetic particle binding. The throughput in this study is not sufficient for an economical scale harvest.

  1. On-chip magnetic separation of superparamagnetic beads for integrated molecular analysis

    Science.gov (United States)

    Florescu, Octavian; Wang, Kevan; Au, Patrick; Tang, Jimmy; Harris, Eva; Beatty, P. Robert; Boser, Bernhard E.

    2010-03-01

    We have demonstrated a postprocessed complementary metal oxide semiconductor (CMOS) integrated circuit (IC) capable of on-chip magnetic separation, i.e., removing via magnetic forces the nonspecifically bound magnetic beads from the detection area on the surface of the chip. Initially, 4.5 ?m wide superparamagnetic beads sedimenting out of solution due to gravity were attracted to the detection area by a magnetic concentration force generated by flowing current through a conductor embedded in the IC. After sedimentation, the magnetic beads that did not bind strongly to the functionalized surface of the IC through a specific biochemical complex were removed by a magnetic separation force generated by flowing current through another conductor placed laterally to the detection area. As the spherical bead pivoted on the surface of the chip, the lateral magnetic force was further amplified by mechanical leveraging, and 50 mA of current flowing through the separation conductor placed 18 ?m away from the bead resulted in 7.5 pN of tensile force on the biomolecular tether immobilizing the bead. This force proved high enough to break nonspecific interactions while leaving specific antibody-antigen bonds intact. A sandwich capture immunoassay on purified human immunoglobulin G showed strong correlation with a control enzyme linked immunosorbent assay and a detection limit of 10 ng/ml or 70 pM. The beads bound to the detection area after on-chip magnetic separation were detected optically. To implement a fully integrated molecular diagnostics platform, the on-chip magnetic separation functionality presented in this work can be readily combine with state-of-the art CMOS-based magnetic bead detection technology.

  2. Biomedical applications of high gradient magnetic separation: progress towards therapeutic haeomofiltration.

    Science.gov (United States)

    Frodsham, George; Pankhurst, Quentin A

    2015-10-01

    High gradient magnetic separation is a well-established technology in the mineral processing industry, and has been used for decades in the bioprocessing industry. Less well known is the increasing role that high gradient magnetic separation is playing in biomedical applications, for both diagnostic and therapeutic purposes. We review here the state of the art in this emerging field, with a focus on therapeutic haemofiltration, the key enabling technologies relating to the functionalisation of magnetic nanoparticles with target-specific binding agents, and the development of extra-corporeal circuits to enable the in situ filtering of human blood. PMID:26439594

  3. Removal of freshwater microalgae by a magnetic separation method

    Science.gov (United States)

    Vergini, Sofia S.; Aravantinou, Andriana F.; Manariotis, Ioannis D.

    2013-04-01

    Some species of microalgae, with high growth rate and high lipid content, appear to be attractive alternatives as a feedstock for biodiesel production. The high-energy input for harvesting biomass and removing the water from the algae makes current commercial microalgal biodiesel production cost expensive. The major techniques currently employed in microalgae harvesting and recovery include centrifugation, coagulation-flocculation, bio-flocculation, filtration and screening, gravity sedimentation, and flotation. The purpose of this study was to investigate the harvesting of microalgae cells by coagulation using magnetic activated carbon, magnetite (FeO4) nanoparticles, and common chemical coagulants. Scenedesmus rubescens was selected and cultivated in 10 L flasks under continuous artificial light. Samples were taken at different operation intervals. Jar tests were conducted to investigate the effect of adsorption of microalgae on the magnetic material. The removal efficiency of microalgae was affected by the coagulants dose, stirring time and speed, and the initial microalgae concentration. The recovery of microalgae was greater in cultures with high initial microalgae concentration compared to cultures with low microalgae concentrations.

  4. Versatile fabrication of magnetic carbon fiber aerogel applied for bidirectional oil-water separation

    Science.gov (United States)

    Li, Yong; Zhu, Xiaotao; Ge, Bo; Men, Xuehu; Li, Peilong; Zhang, Zhaozhu

    2015-09-01

    Fabricating functional materials that can solve environmental problems resulting from oil or organic solvent pollution is highly desired. However, expensive materials or complicated procedures and unidirectional oil-water separation hamper their applications. Herein, a magnetic superhydrophobic carbon fiber aerogel with high absorption capacity was developed by one-step pyrolysis of Fe(NO3)3-coated cotton in an argon atmosphere. The obtained aerogel can selectively collect oils from oil-polluted region by a magnet bar owing to its magnetic properties and achieves fast oil-water separation for its superhydrophobicity and superoleophilicity. Furthermore, the aerogel performs recyclable oil absorption capacity even after ten cycles of oil-water separation and bears organic solvent immersion. Importantly, the obtained aerogel turns to superhydrophilic and underwater superoleophobic after thermal treatment, allowing it as a promising and efficient material for bidirectional oil-water separation and organic contaminants removal.

  5. Magnetic two-dimensional molecularly imprinted materials for the recognition and separation of proteins.

    Science.gov (United States)

    Chen, Fangfang; Zhao, Weifeng; Zhang, Jingjing; Kong, Jie

    2015-12-23

    Surface molecular imprinting for proteins is an emerging cross-field of molecular imprinting engineering and functional materials. In this contribution, we report a novel design of magnetic two-dimensional molecularly imprinted polymers (2D-MIPs) for the high recognition and separation of proteins. Bovine serum albumin-surface-imprinted polydopamines were prepared on the surfaces of the magnetic Fe3O4-graphene oxide hybrid to form magnetic 2D-MIPs for proteins. The 2D Fe3O4-graphene oxide substrate possesses a dominant surface-to-volume ratio in comparison to 3D spherical substrates with the same volume. These materials are sensitive to a magnetic field and can be easily separated using an external magnet. The binding experimental results of bovine serum albumin on magnetic 2D-MIPs and real sample analysis demonstrated the high recognition specificity, selectivity, accessibility and convenient separation of 2D-MIPs for template protein. The design and synthesis of magnetic 2D-MIPs provide a new perspective for the surface molecularly imprinted materials with potential in the recognition and separation of proteins. PMID:26388494

  6. Circular Halbach array for fast magnetic separation of hyaluronan-expressing tissue progenitors.

    Science.gov (United States)

    Joshi, Powrnima; Williams, P Stephen; Moore, Lee R; Caralla, Tonya; Boehm, Cynthia; Muschler, George; Zborowski, Maciej

    2015-10-01

    Connective tissue progenitors (CTPs) are a promising therapeutic agent for bone repair. Hyaluronan, a high molecular mass glycosaminoglycan, has been shown by us to be a suitable biomarker for magnetic separation of CTPs from bone marrow aspirates in a canine model. For the therapy to be applicable in humans, the magnetic separation process requires scale-up without compromising the viability of the cells. The scaled-up device presented here utilizes a circular Halbach array of diametrically magnetized, cylindrical permanent magnets. This allows precise control of the magnetic field gradient driving the separation, with theoretical analysis favoring a hexapole field. The separation vessel has the external diameter of a 50 mL conical centrifuge tube and has an internal rod that excludes cells from around the central axis. The magnet and separation vessel (collectively dubbed the hexapole magnet separator or HMS) was tested on four human and four canine bone marrow aspirates. Each CTP-enriched cell product was tested using cell culture bioassays as surrogates for in vivo engraftment quality. The magnetically enriched cell fractions showed statistically significant, superior performance compared to the unenriched and depleted cell fractions for all parameters tested, including CTP prevalence (CTPs per 10(6) nucleated cells), proliferation by colony forming unit (CFU) counts, and differentiation by staining for the presence of osteogenic and chondrogenic cells. The simplicity and speed of the HMS operation could allow both CTP isolation and engraftment during a single surgical procedure, minimizing trauma to patients and lowering cost to health care providers. PMID:26368657

  7. Optimisation of magnetic separation: a case study for soil washing at a heavy metals polluted site.

    Science.gov (United States)

    Sierra, C; Martnez-Blanco, D; Blanco, Jess A; Gallego, J R

    2014-07-01

    Sandy loam soil polluted with heavy metals (As, Cu, Pb and Zn) from an ancient Mediterranean Pb mining and metallurgy site was treated by means of wet high-intensity magnetic separation to remove some of the pollutants therein. The treated fractions were chemically analysed and then subjected to magnetic characterisation, which determined the high-field specific (mass), magnetic susceptibility (?) and the specific (mass) saturation magnetisation (?S), through isothermal remanent magnetisation (IRM) curves. From the specific values of ? and ?S, a new expression to assess the performance of the magnetic separation operation was formulated and verified by comparison with the results obtained by traditional chemical analysis. The magnetic study provided valuable information for the exhaustive explanation of the operation, and the deduced mathematical expression was found to be appropriate to estimate the performance of the separation operation. From these results we determined that magnetic soil washing was effective for the treatment of the contaminated soil, concentrating the majority of the heavy metals and peaking its separation capacity at 60% of the maximum output voltage. PMID:24418067

  8. Magnetically assisted chemical separation (MACS) process: Preparation and optimization of particles for removal of transuranic elements

    International Nuclear Information System (INIS)

    The Magnetically Assisted Chemical Separation (MACS) process combines the selectivity afforded by solvent extractants with magnetic separation by using specially coated magnetic particles to provide a more efficient chemical separation of transuranic (TRU) elements, other radionuclides, and heavy metals from waste streams. Development of the MACS process uses chemical and physical techniques to elucidate the properties of particle coatings and the extent of radiolytic and chemical damage to the particles, and to optimize the stages of loading, extraction, and particle regeneration. This report describes the development of a separation process for TRU elements from various high-level waste streams. Polymer-coated ferromagnetic particles with an adsorbed layer of octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) diluted with tributyl phosphate (TBP) were evaluated for use in the separation and recovery of americium and plutonium from nuclear waste solutions. Due to their chemical nature, these extractants selectively complex americium and plutonium contaminants onto the particles, which can then be recovered from the solution by using a magnet. The partition coefficients were larger than those expected based on liquid[liquid extractions, and the extraction proceeded with rapid kinetics. Extractants were stripped from the particles with alcohols and 400-fold volume reductions were achieved. Particles were more sensitive to acid hydrolysis than to radiolysis. Overall, the optimization of a suitable NMCS particle for TRU separation was achieved under simulant conditions, and a MACS unit is currently being designed for an in-lab demonstration

  9. Magnetically assisted chemical separation (MACS) process: Preparation and optimization of particles for removal of transuranic elements

    Energy Technology Data Exchange (ETDEWEB)

    Nunez, L.; Kaminski, M.; Bradley, C.; Buchholz, B.A.; Aase, S.B.; Tuazon, H.E.; Vandegrift, G.F. [Argonne National Lab., IL (United States); Landsberger, S. [Univ. of Illinois, Urbana, IL (United States)

    1995-05-01

    The Magnetically Assisted Chemical Separation (MACS) process combines the selectivity afforded by solvent extractants with magnetic separation by using specially coated magnetic particles to provide a more efficient chemical separation of transuranic (TRU) elements, other radionuclides, and heavy metals from waste streams. Development of the MACS process uses chemical and physical techniques to elucidate the properties of particle coatings and the extent of radiolytic and chemical damage to the particles, and to optimize the stages of loading, extraction, and particle regeneration. This report describes the development of a separation process for TRU elements from various high-level waste streams. Polymer-coated ferromagnetic particles with an adsorbed layer of octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) diluted with tributyl phosphate (TBP) were evaluated for use in the separation and recovery of americium and plutonium from nuclear waste solutions. Due to their chemical nature, these extractants selectively complex americium and plutonium contaminants onto the particles, which can then be recovered from the solution by using a magnet. The partition coefficients were larger than those expected based on liquid[liquid extractions, and the extraction proceeded with rapid kinetics. Extractants were stripped from the particles with alcohols and 400-fold volume reductions were achieved. Particles were more sensitive to acid hydrolysis than to radiolysis. Overall, the optimization of a suitable NMCS particle for TRU separation was achieved under simulant conditions, and a MACS unit is currently being designed for an in-lab demonstration.

  10. Particle Capture Efficiency in a Multi-Wire Model for High Gradient Magnetic Separation

    CERN Document Server

    Eisenträger, Almut; Griffiths, Ian M

    2014-01-01

    High gradient magnetic separation (HGMS) is an efficient way to remove magnetic and paramagnetic particles, such as heavy metals, from waste water. As the suspension flows through a magnetized filter mesh, high magnetic gradients around the wires attract and capture the particles, removing them from the fluid. We model such a system by considering the motion of a paramagnetic tracer particle through a periodic array of magnetized cylinders. We show that there is a critical Mason number (ratio of viscous to magnetic forces) below which the particle is captured irrespective of its initial position in the array. Above this threshold, particle capture is only partially successful and depends on the particle's entry position. We determine the relationship between the critical Mason number and the system geometry using numerical and asymptotic calculations. If a capture efficiency below 100% is sufficient, our results demonstrate how operating the HGMS system above the critical Mason number but with multiple separa...

  11. Simulating Chiral Magnetic and Separation Effects with Spin-Orbit Coupled Atomic Gases.

    Science.gov (United States)

    Huang, Xu-Guang

    2016-01-01

    The chiral magnetic and chiral separation effects-quantum-anomaly-induced electric current and chiral current along an external magnetic field in parity-odd quark-gluon plasma-have received intense studies in the community of heavy-ion collision physics. We show that analogous effects occur in rotating trapped Fermi gases with Weyl-Zeeman spin-orbit coupling where the rotation plays the role of an external magnetic field. These effects can induce a mass quadrupole in the atomic cloud along the rotation axis which may be tested in future experiments. Our results suggest that the spin-orbit coupled atomic gases are potential simulators of the chiral magnetic and separation effects. PMID:26868084

  12. Botryococcus braunii cells: ultrasound-intensified outdoor cultivation integrated with in situ magnetic separation.

    Science.gov (United States)

    Wang, Shi-Kai; Wang, Feng; Stiles, Amanda R; Guo, Chen; Liu, Chun-Zhao

    2014-09-01

    An integrated system combining ultrasound-intensified outdoor cultivation of Botryococcus braunii with in situ magnetic harvesting of the algal cells was developed. The algal cells were cultivated in 200 L plastic bag reactors, and seven five-minute ultrasonic treatments at a four-day interval using a fixed frequency of 40 kHz and a total power of 300 W improved algal cell biomass and hydrocarbon productivity. The algal cells were harvested using functional magnetic particles and a magnetic separator, and a recovery efficiency of 90% was obtained under continuous operation at a flow rate of 100mL/min using the in situ magnetic separation system. The overall production cost using the integrated system was US$ 25.14 per kilogram of B. braunii dry biomass. The system developed in this study provides a base for the industrial production of B. braunii. PMID:24998478

  13. Closed-loop magnetic separation of nanoparticles on a packed bed of spheres

    Science.gov (United States)

    Magnet, Ccilia; Akouala, Mesferdon; Kuzhir, Pavel; Bossis, Georges; Zubarev, Andrey; Wereley, Norman M.

    2015-05-01

    In this work, we consider magnetic separation of iron oxide nanoparticles when a nanoparticle suspension (diluted ferrofluid) passes through a closed-loop filter composed of a packed bed of micro-beads magnetized by an externally applied magnetic field. We show that the capture of nanoparticles of a size as small as 60 nm is easily achieved at low-to-moderate magnetic fields (16-32 kA/m) thanks to relatively strong magnetic interactions between them. The key parameter governing the capture process is the Mason numberthe ratio of hydrodynamic-to-magnetic forces exerted to nanoparticles. The filter efficiency, ?, defined through the ratio of the inlet-to-outlet concentration shows a power-law dependency on Mason number, ??M a-0.83 , in the range of 102magnetic nanoparticles, followed by magnetic separation of the nanoparticles.

  14. Optimized high gradient magnetic separation for isolation of Plasmodium-infected red blood cells

    OpenAIRE

    Chimma Pattamawan; Pannadaporn Peeranad; Sratongno Panudda; Somsri Sangdao; Ottinger Annette; Bhakdi Sebastian C; Malasit Prida; Pattanapanyasat Kovit; Neumann Hartmut PH

    2010-01-01

    Abstract Background Highly purified infected red blood cells (irbc), or highly synchronized parasite cultures, are regularly required in malaria research. Conventional isolation and synchronization rely on density and osmotic fragility of irbc, respectively. High gradient magnetic separation (HGMS) offers an alternative based on intrinsic magnetic properties of irbc, avoiding exposure to chemicals and osmotic stress. Successful HGMS concentration in malaria research was previously reported us...

  15. Theoretical and Experimental Study of the Magnetic Separation of Pollutants from Wastewater

    OpenAIRE

    Mariani, Giacomo

    2010-01-01

    This Thesys reports the study of a HGMS (High GradientMagnetic Separation) process for the treatment of industrialwastewaters that considers an assisted chemical-physical pre-treatment for the removal of heavy metals through the bound by adsorption with added iron-oxide particulate matter (hematite). The considered filter, constituted by ferromagnetic stainless steel wool and permanent magnets, is studied with a new approach based on a statistical analysis that requires the study of the traje...

  16. Recovery of iron from cyanide tailings with reduction roasting-water leaching followed by magnetic separation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yali; Li, Huaimei [College of Chemical Engineering, Shandong University of Technology, 255081, Zibo, Shandong (China); Yu, Xianjin, E-mail: xjy@sdut.edu.cn [College of Chemical Engineering, Shandong University of Technology, 255081, Zibo, Shandong (China)

    2012-04-30

    Highlights: Black-Right-Pointing-Pointer Using reduction roasting-water leaching-magnetic separation method, the recovery of iron from cyanide tailings was optimized. Black-Right-Pointing-Pointer The recovery of iron was highly depended on the water-leaching process after reduction roasting. Black-Right-Pointing-Pointer The results suggest that the method can be effectively used for iron recovery, and the grade of magnetic concentrate and recovery rate can reach 59.11% and 75.12%, respectively. - Abstract: Cyanide tailing is a kind of solid waste produced in the process of gold extraction from gold ore. In this paper, recovery of iron from cyanide tailings was studied with reduction roasting-water leaching process followed by magnetic separation. After analysis of chemical composition and crystalline phase, the effects of different parameters on recovery of iron were chiefly introduced. Systematic studies indicate that the high recovery rate and grade of magnetic concentrate of iron can be achieved under the following conditions: weight ratios of cyanide tailings/activated carbon/sodium carbonate/sodium sulfate, 100:10:3:10; temperature, 50 Degree-Sign C; time, 60 min at the reduction roasting stage; the liquid to solid ratio is 15:1 (ml/g), leaching at 60 Degree-Sign C for 5 min and stirring speed at 20 r/min at water-leaching; exciting current is 2 A at magnetic separation. The iron grade of magnetic concentrate was 59.11% and the recovery ratio was 75.12%. The mineralography of cyanide tailings, roasted product, water-leached sample, magnetic concentrate and magnetic tailings were studied by X-ray powder diffraction (XRD) technique. The microstructures of above products except magnetic tailings were also analyzed by scanning electron microscope (SEM) and energy disperse spectroscopy (EDS) to help understand the mechanism.

  17. Recovery of iron from cyanide tailings with reduction roastingwater leaching followed by magnetic separation

    International Nuclear Information System (INIS)

    Highlights: ? Using reduction roastingwater leachingmagnetic separation method, the recovery of iron from cyanide tailings was optimized. ? The recovery of iron was highly depended on the water-leaching process after reduction roasting. ? The results suggest that the method can be effectively used for iron recovery, and the grade of magnetic concentrate and recovery rate can reach 59.11% and 75.12%, respectively. - Abstract: Cyanide tailing is a kind of solid waste produced in the process of gold extraction from gold ore. In this paper, recovery of iron from cyanide tailings was studied with reduction roastingwater leaching process followed by magnetic separation. After analysis of chemical composition and crystalline phase, the effects of different parameters on recovery of iron were chiefly introduced. Systematic studies indicate that the high recovery rate and grade of magnetic concentrate of iron can be achieved under the following conditions: weight ratios of cyanide tailings/activated carbon/sodium carbonate/sodium sulfate, 100:10:3:10; temperature, 50 C; time, 60 min at the reduction roasting stage; the liquid to solid ratio is 15:1 (ml/g), leaching at 60 C for 5 min and stirring speed at 20 r/min at water-leaching; exciting current is 2 A at magnetic separation. The iron grade of magnetic concentrate was 59.11% and the recovery ratio was 75.12%. The mineralography of cyanide tailings, roasted product, water-leached sample, magnetic concentrate and magnetic tailings were studied by X-ray powder diffraction (XRD) technique. The microstructures of above products except magnetic tailings were also analyzed by scanning electron microscope (SEM) and energy disperse spectroscopy (EDS) to help understand the mechanism.

  18. Magnetic separation as an adjunct to surface barrier detectors for backscattering and ion reaction analysis methods

    International Nuclear Information System (INIS)

    The sensitivity of analysis by energy spectroscopy of product ions using solid state detectors is often limited by instrumental background from pulse pileup, due to an intense flux of lower energy ions scattered from the accelerator beam. A small magnet can be used for low resolution separation of ions of different type and/or energy. In the present work a simple permanent magnet is used to reject ions of low magnetic rigidity. The technique has been developed for the depth profiling of oxygen in solar absorber surfaces using the 18O(p,?) reaction, and to determine surface trces of gold on silicon substrates

  19. Recovery of iron from cyanide tailings with reduction roasting-water leaching followed by magnetic separation.

    Science.gov (United States)

    Zhang, Yali; Li, Huaimei; Yu, Xianjin

    2012-04-30

    Cyanide tailing is a kind of solid waste produced in the process of gold extraction from gold ore. In this paper, recovery of iron from cyanide tailings was studied with reduction roasting-water leaching process followed by magnetic separation. After analysis of chemical composition and crystalline phase, the effects of different parameters on recovery of iron were chiefly introduced. Systematic studies indicate that the high recovery rate and grade of magnetic concentrate of iron can be achieved under the following conditions: weight ratios of cyanide tailings/activated carbon/sodium carbonate/sodium sulfate, 100:10:3:10; temperature, 50 C; time, 60 min at the reduction roasting stage; the liquid to solid ratio is 15:1 (ml/g), leaching at 60 C for 5 min and stirring speed at 20 r/min at water-leaching; exciting current is 2A at magnetic separation. The iron grade of magnetic concentrate was 59.11% and the recovery ratio was 75.12%. The mineralography of cyanide tailings, roasted product, water-leached sample, magnetic concentrate and magnetic tailings were studied by X-ray powder diffraction (XRD) technique. The microstructures of above products except magnetic tailings were also analyzed by scanning electron microscope (SEM) and energy disperse spectroscopy (EDS) to help understand the mechanism. PMID:22333161

  20. Design of large aperture superferric quadrupole magnets for an in-flight fragment separator

    Energy Technology Data Exchange (ETDEWEB)

    Zaghloul, Aziz; Kim, Dogyun; Kim, Jangyoul; Kim, Mijung; Kim, Myeongjin; Yun, Chongcheoul; Kim, Jongwon [Rare Isotope Science Project, Institute for Basic Science, Yuseong, Daejeon, 305-811 (Korea, Republic of)

    2014-01-29

    Superferric quadrupole magnets to be used for in-flight fragment separator have been designed. A quadrupole magnet triplet for beam focusing is placed in a cryostat together with superconducting correction coils. To maximize acceptance of rare isotope beams produced by projectile fragmentation, it is essential to use large-aperture quadrupole magnets. The pole tip radius is 17 cm in the current design, and we tried to enlarge the aperture with 3D analysis on magnetic fields. In the front end of the separator, where a target and beam dump are located, we plan to use two sets of quadrupole triplets made of high-Tc superconductor (HTS) operating at 20-50 K considering high radiation heat load. The HTS magnet will use warm iron poles. Both low-Tc and high-Tc superconductors are acquired for test winding, and two kinds of dewar and cryostat are under construction to perform the coil and magnet tests. The magnetic design of superferric quadrupole is mainly discussed.

  1. New High Performance Magnet Structures for Bead Based MolecularSeparation

    Energy Technology Data Exchange (ETDEWEB)

    Humphries, David

    2005-06-01

    New High Performance Magnet Structures for Bead Based Molecular Separation David Humphries Lawrence Berkeley National Laboratory, D.O.E. Joint Genome Institute Abstract High performance Hybrid magnetic separation technology is under continuing development at the D.O.E. Joint Genome Institute and Lawrence Berkeley National Laboratory for general laboratory and high throughput automated applications. This technology has broad applicability for molecular separation in genomics, proteomics and other areas. It s applicability ranges from large and small scale microtiter plate and flow separation processes to single molecule DNA manipulation. It is currently an enabling purification technology for very high throughput production sequencing at the D.O.E. Joint Genome Institute. This technology incorporates hybrid magnetic structures that combine linear permanent magnet material and ferromagnetic material to produce significantly higher fields and gradients than those of currently available commercial devices. These structures incorporate ferromagnetic poles that can be easily shaped to produce complex field distributions for specialized applications. The higher maximum fields and strong gradients of the hybrid structures result in greater holding forces on magnetized targets that are being processed as well as faster extraction. Current development versions of these magnet plates have exhibited fields in excess of 1.0 tesla and gradients approaching 1000.0 tesla/meter. Second generation Hybrid magnet plates have now been developed for both 384 and 96-well applications. This technology is currently being made available to industry through the Tech Transfer Department at Lawrence Berkeley National Laboratory. This work was performed under the auspices of the US Department of Energy's Office of Science, Biological and Environmental Research Program and the by the University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48, Lawrence Berkeley National Laboratory under contract No. DE-AC03-6SF00098 and Los Alamos National Laboratory under contract No. W-7405-ENG-36.

  2. Purification of condenser water in thermal power station by superconducting magnetic separation

    Science.gov (United States)

    Ha, D. W.; Kwon, J. M.; Baik, S. K.; Lee, Y. J.; Han, K. S.; Ko, R. K.; Sohn, M. H.; Seong, K. C.

    2011-11-01

    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 6 T 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 ?-Fe 2O 3 (hematite) and ?-Fe 2O 3 (maghemite). The higher magnetic field was applied up to 6 T, the more iron oxides were removed. As the wire diameter of magnetic filter decreased, the turbidity removal of the sample was enhanced.

  3. High intensity magnetic separation for the clean-up of a site polluted by lead metallurgy.

    Science.gov (United States)

    Sierra, C; Martnez, J; Menndez-Aguado, J M; Afif, E; Gallego, J R

    2013-03-15

    The industrial history in the district of Linares (Spain) has had a severe impact on soil quality. Here we examined soil contaminated by lead and other heavy metals in "La Cruz" site, a brownfield affected by metallurgical residues. Initially, the presence of contaminants mainly associated with the presence of lead slag fragments mixed with the soil was evaluated. The subsequent analysis showed a quasi-uniform distribution of the pollution irrespective of the grain-size fractions. This study was accompanied by a characterization of the lead slag behavior under the presence of a magnetic field. Two main magnetic components were detected: first a ferromagnetic and/or ferrimagnetic contribution, second a paramagnetic and/or antiferromagnetic one. It was also established that the slag was composed mainly of lead spherules and iron oxides embedded in a silicate matrix. Under these conditions, the capacity of magnetic separation to remove pollutants was examined. Therefore, two high intensity magnetic separators (dry and wet devices, respectively) were used. Dry separation proved to be successful at decontaminating soil in the first stages of a soil washing plant. In contrast, wet separation was found effective as a post-process for the finer fractions. PMID:23357508

  4. Desulphurisation of coal pyrolysis and magnetic separation. Desulfuracion de carbones mediante pirolisis y separacion magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, J.C.; Ayala, N.; Ibarra, J.V.; Moliner, R.; Miranda, J.L.; Vazquez, A. (CENIM, Madrid (Spain))

    1991-07-01

    The desulphurisation of coal intended for use inthermal power stations is a priority issue in the national strategy for the reduction of acid rain. This article studies the feasibility of eliminating pyritic sulphur from coal by physical methods using high intensity pyrolysis and magnetic separation. 6 refs., 9 figs., 4 tabs.

  5. Magnetic separation of colloidal nanoparticle mixtures using a material specific peptide.

    Science.gov (United States)

    Essinger-Hileman, Elizabeth R; Popczun, Eric J; Schaak, Raymond E

    2013-06-18

    A material specific peptide bound to Fe2O3 facilitates the selective sequestration of Au from a colloidal mixture of Au and CdS nanoparticles; the Au-Fe2O3 precipitate can then be magnetically separated from the colloidal CdS, and the Au nanoparticles can be recovered upon release from the Fe2O3. PMID:23661051

  6. Separation of flow from chiral magnetic effect in U+U collisions using spectator asymmetry

    CERN Document Server

    Chatterjee, Sandeep

    2014-01-01

    We demonstrate that the prolate shape of the Uranium nucleus generates anti-correlation between spectator asymmetry and initial state ellipticity of the collision zone, providing a way to constrain the initial event shape in U+U collisions. As an application, we show that this can be used to separate the background contribution due to flow from the signals of chiral magnetic effect.

  7. Removal of less biodegradable dissolved organic matters in water by superconducting magnetic separation with magnetic mesoporous carbon

    International Nuclear Information System (INIS)

    Less biodegradable dissolved organic matters in water as typified by humic substances are known as precursors of carcinogenic trihalomethanes, and are removed about 60% by current advanced water treatments. However, further increase of the removal ratio is demand. In this study, magnetic mesoporous carbon (MMPC), which can adsorb the substances physically and be efficiently collected by using superconducting high gradient magnetic separation (HGMS), has been synthesized with coconut-shell-based activated carbon and ferric nitrate solution by the gas activation method. The MMPC has the maximum magnetization value of 30.7 emu/g and an adsorption ability of 87% to 10 mg/L humic acid in a short time. The standard MMPC having a magnetization of 6.43 emu/g was able to be separated at magnetic field of 2 T. Used MMPC regained the adsorption ability to 93.1% by N2 reactivation heat treatment. These results show promise for application of current water treatments by superconducting HGMS, which is suitable for high-speed water treatment without secondary wastes.

  8. Removal of less biodegradable dissolved organic matters in water by superconducting magnetic separation with magnetic mesoporous carbon

    Science.gov (United States)

    Kondo, K.; Jin, T.; Miura, O.

    2010-11-01

    Less biodegradable dissolved organic matters in water as typified by humic substances are known as precursors of carcinogenic trihalomethanes, and are removed about 60% by current advanced water treatments. However, further increase of the removal ratio is demand. In this study, magnetic mesoporous carbon (MMPC), which can adsorb the substances physically and be efficiently collected by using superconducting high gradient magnetic separation (HGMS), has been synthesized with coconut-shell-based activated carbon and ferric nitrate solution by the gas activation method. The MMPC has the maximum magnetization value of 30.7 emu/g and an adsorption ability of 87% to 10 mg/L humic acid in a short time. The standard MMPC having a magnetization of 6.43 emu/g was able to be separated at magnetic field of 2 T. Used MMPC regained the adsorption ability to 93.1% by N 2 reactivation heat treatment. These results show promise for application of current water treatments by superconducting HGMS, which is suitable for high-speed water treatment without secondary wastes.

  9. Double-Layer Magnetic Nanoparticle-Embedded Silica Particles for Efficient Bio-Separation

    Science.gov (United States)

    Kang, Homan; Cho, Hong-Jun; Park, Sung-Jun; Yang, Jin-Kyoung; Kim, Sehoon; Kim, Hyung-Mo; Jun, Bong-Hyun; Lee, Yoon-Sik

    2015-01-01

    Superparamagnetic Fe3O4 nanoparticles (NPs) based nanomaterials have been exploited in various biotechnology fields including biomolecule separation. However, slow accumulation of Fe3O4 NPs by magnets may limit broad applications of Fe3O4 NP-based nanomaterials. In this study, we report fabrication of Fe3O4 NPs double-layered silica nanoparticles (DL MNPs) with a silica core and highly packed Fe3O4 NPs layers. The DL MNPs had a superparamagnetic property and efficient accumulation kinetics under an external magnetic field. Moreover, the magnetic field-exposed DL MNPs show quantitative accumulation, whereas Fe3O4 NPs single-layered silica nanoparticles (SL MNPs) and silica-coated Fe3O4 NPs produced a saturated plateau under full recovery of the NPs. DL MNPs are promising nanomaterials with great potential to separate and analyze biomolecules. PMID:26599084

  10. Magnetic separation of Dy(III) ions from homogeneous aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Pulko, B., E-mail: Barbara.Pulko@tu-dresden.de; Yang, X.; Lei, Z.; Odenbach, S.; Eckert, K., E-mail: Kerstin.Eckert@tu-dresden.de [Institute of Fluid Mechanics, Chair of Magnetofluiddynamics, Measuring and Automation Technology, Technische Universitt Dresden, Dresden 01069 (Germany)

    2014-12-08

    The possibility to enrich paramagnetic dysprosium(III) ions in a magnetic field gradient is proved by means of interferometry, which may open the route for a magnetic separation of rare earth ions from aqueous solutions. The separation dynamics are studied for three different concentrations of DyCl{sub 3} and compared with those found recently in a sulphate solution of the 3d ion Mn(II). In view of the similar-sized hydration spheres for Dy(III) and Mn(II), the slower separation dynamics in DyCl{sub 3} is attributed to both a higher densification coefficient and the strong impact of Brownian motion due to the absence of ion-pair clusters.

  11. Particle capture efficiency in a multi-wire model for high gradient magnetic separation

    KAUST Repository

    Eisenträger, Almut

    2014-07-21

    High gradient magnetic separation (HGMS) is an efficient way to remove magnetic and paramagnetic particles, such as heavy metals, from waste water. As the suspension flows through a magnetized filter mesh, high magnetic gradients around the wires attract and capture the particles removing them from the fluid. We model such a system by considering the motion of a paramagnetic tracer particle through a periodic array of magnetized cylinders. We show that there is a critical Mason number (ratio of viscous to magnetic forces) below which the particle is captured irrespective of its initial position in the array. Above this threshold, particle capture is only partially successful and depends on the particle\\'s entry position. We determine the relationship between the critical Mason number and the system geometry using numerical and asymptotic calculations. If a capture efficiency below 100% is sufficient, our results demonstrate how operating the HGMS system above the critical Mason number but with multiple separation cycles may increase efficiency. © 2014 AIP Publishing LLC.

  12. Gravitational and magnetic separation in self-assembled clay-ferrofluid nanocomposites

    Scientific Electronic Library Online (English)

    F.L.O., Paula; G.J. da, Silva; R., Aquino; J., Depeyrot; J.O., Fossum; K.D., Knudsen; G., Helgesen; F.A., Tourinho.

    2009-04-01

    Full Text Available We report on experimental observations of self-assemblies in colloidal dispersions of clay nanoplatelets and magnetic nanoparticles. Visual observations have been combined with small angle X-ray scattering (SAXS) in the study of several composites at a fixed clay concentration in the dilute regime, [...] and varying ferrofluid concentrations. Our visual observations which encompass macroscopic separation in gravitational- and magnetic field, indicate that all samples present a concentrated phase and a diluted one. SAXS data obtained from each phase are consistent with the interpretation that the scattering contribution from the clay nano-platelets in the samples can be neglected in comparison with the magnetic particle contribution. The analysis of the scattered intensity is performed combining two models, one based on the global scattering function and the other allowing the extraction of the structure factor of the mixtures. The parameters of the size distribution of magnetic nanoparticles determined by both methods are in good agreement. The structure factor of the mixtures shows that on a local scale, the mixtures behave like a gas of isolated magnetic nanoparticles. It also indicates the presence of interactions between magnetic nanoparticles mediated by the presence of Laponite platelets. Such interactions could be attributed with a progressive partial phase separation between spheres and discs rather than to the formation of dense aggregates.

  13. Magnetic and transport properties of phase-separated manganite BiLaCaMnO

    Science.gov (United States)

    Zhang, R. R.; Kuang, G. L.; Zhao, B. C.; Sun, Y. P.

    2010-01-01

    We have investigated the magnetic and transport properties of Bi 0.1La 0.5Ca 0.4MnO 3 manganite, systematically. Four distinct feature temperature points in the temperature dependence of the magnetization curve M(T) occurring at 218 K, 181 K,112 K and 38 K are observed; these are suggested to be related to charge ordered (CO), weak ferromagnetic (FM), strong FM, and blocked metastable state. These temperature points can be changed by applying magnetic fields. The field-cooled (FC) M(T) curves show an obvious thermal hysteresis between the FC cooling (FCC) and FC warming (FCW) measuring process. The large variation between the FC and zero-field-cooled (ZFC) magnetization curves at low temperatures reflects the existence of blocked metastable states separated by high energy barriers. The blocked state can be weakened or eventually destroyed by applying magnetic fields. The field dependence of the magnetization and resistivity at both 5 K and 130 K shows that the magnetic and electrical transport properties are tightly correlated with the same critical field. The results indicate that CO and FM phases coexist in the sample at low temperatures. The local lattice distortion induced by the Bi 3+ doping may play an important role in the complex magnetic and transport properties of the sample.

  14. A comprehensive in vitro investigation of a portable magnetic separator device for human blood detoxification

    International Nuclear Information System (INIS)

    A portable magnetic separator device is being developed for a proposed magnetically based detoxification system. In this paper, the performance of this device was evaluated via preliminary in vitro flow experiments using simple fluids and a separator unit consisting of one tube and two metal wires, each at the top and bottom of the tube. The effects of the following factors were observed: mean flow velocity Uo (0.14-45 cm s-1), magnetic field strength ?oHo (0.125-0.50 T), wire size Rw (0.125, 0.250 and 0.500 mm), wire length Lw (2, 5 and 10 cm), wire materials (nickel, stainless steel 304 and 430) and tube size (outer radius Ro = 0.30 mm and inner radius Ri = 0.25 mm; Ro = 0.50 mm and Ri = 0.375 mm; and Ro = 2.0 mm and Ri = 1.0 mm). Our observations showed that the experimental results fit well with the corresponding theoretical results from the model we previously developed at a low flow velocity area (for example, Uo ? 20 cm s-1), strong external magnetic field (for example, ?0.30 T) and long wire length (for example, Lw = 10 cm). The experimental results also showed that more than 90% capture efficiency is indeed achievable under moderate systemic and operational conditions. Pressure drop measurements revealed that the device could work well under human physiological and clinical conditions, and sphere buildup would not have any considerable effect on the pressure drop of the device. The breakthrough experiments demonstrated that a lower flow rate V, higher applied magnetic field ?oHo and diluted sphere suspension, i.e. lower Co, would delay the breakthrough. All the results indicate the promise of this portable magnetic separator device to efficiently in vivo sequestrate nano-/micro-spheres from blood flow in the future magnetically based detoxification system

  15. Measurement of the adhesion force between particles for high gradient magnetic separation of pneumatic conveyed powder products

    Science.gov (United States)

    Senkawa, K.; Nakai, Y.; Mishima, F.; Akiyama, Y.; Nishijima, S.

    2011-11-01

    In the industrial plants such as foods, medicines or industrial materials, there are big amount of issues on contamination by metallic wear debris originated from pipes of manufacturing lines. In this study, we developed a high gradient magnetic separation system (HGMS) under the dry process by using superconducting magnet to remove the ferromagnetic particles. One of the major problems of dry HGMS systems is, however, the blockage of magnetic filter caused by particle coagulation or deposition. In order to actualize the magnetic separation without blockage, we introduced pneumatic conveyance system as a new method to feed the powder. It is important to increase the drag force acting on the sufficiently dispersed particles, which require strong magnetic fields. To generate the strong magnetic fields, HGMS technique was examined which consists of a magnetic filter and a superconducting solenoid magnet. As a result of the magnetic separation experiment, it was shown that the separation efficiency changes due to the difference of the cohesive property of the particles. On the basis of the result, the adhesion force which acts between the ferromagnetic particles and the medium particles used for the magnetic separation was measured by Atomic Force Microscope (AFM), and cohesion of particles was studied from the aspect of interparticle interaction. We assessed a suitable flow velocity for magnetic separation according to the cohesive property of each particle based on the result.

  16. Measurement of the adhesion force between particles for high gradient magnetic separation of pneumatic conveyed powder products

    International Nuclear Information System (INIS)

    In the industrial plants such as foods, medicines or industrial materials, there are big amount of issues on contamination by metallic wear debris originated from pipes of manufacturing lines. In this study, we developed a high gradient magnetic separation system (HGMS) under the dry process by using superconducting magnet to remove the ferromagnetic particles. One of the major problems of dry HGMS systems is, however, the blockage of magnetic filter caused by particle coagulation or deposition. In order to actualize the magnetic separation without blockage, we introduced pneumatic conveyance system as a new method to feed the powder. It is important to increase the drag force acting on the sufficiently dispersed particles, which require strong magnetic fields. To generate the strong magnetic fields, HGMS technique was examined which consists of a magnetic filter and a superconducting solenoid magnet. As a result of the magnetic separation experiment, it was shown that the separation efficiency changes due to the difference of the cohesive property of the particles. On the basis of the result, the adhesion force which acts between the ferromagnetic particles and the medium particles used for the magnetic separation was measured by Atomic Force Microscope (AFM), and cohesion of particles was studied from the aspect of interparticle interaction. We assessed a suitable flow velocity for magnetic separation according to the cohesive property of each particle based on the result.

  17. Model Magnet Development of D1 Beam Separation Dipole for the HL-LHC Upgrade

    CERN Document Server

    Nakamoto, T; Kawamata, H; Enomoto, S; Higashi, N; Idesaki, A; Iio, M; Ikemoto, Y; Iwasaki, R; Kimura, N; Ogitsu, T; Okada, N; Sasaki, K I; Yoshida, M; Todesco, E

    2014-01-01

    KEK has been conducting the design study of the beam separation dipole magnet, D1, for the High Luminosity LHC (HL-LHC) upgrade within a framework of the CERN-KEK collaboration. The D1 magnet has a coil aperture of 150 mm using Nb-Ti superconducting cable and the nominal dipole field of 5.6 T can be generated at 12 kA and 1.9 K. A field integral of 35 Tm is required. The development of the 2-m-long model magnet has been started since May 2013. This paper describes the development status of the short model magnet as well as advancement of the fundamental design studies.

  18. Development of 5 T NbTi Superconducting Magnet with 160 mm Warm Bore for Magnetic Separation

    International Nuclear Information System (INIS)

    A wide-bore 5 T NbTi superconducting magnet, for magnetic separator, with an operational current of 106 A is designed and fabricated. This magnet with a oe 60 mm room-temperature bore is installed in a vacuum cryostat and immersed in liquid helium. A two-stage 4 K Gifford-McMahon (GM) cryocooler is used to maintain the cooling shield at 70 K and the condenser at 4 K in order to achieve the zero vaporization loss of liquid helium. The cooling power of the GM cryocooler is 1.5 W. In this paper, the design, heat leakage, stress analysis, quench protection characteristics and preliminary test results are presented.

  19. A simple and rapid harvesting method for microalgae by in situ magnetic separation.

    Science.gov (United States)

    Xu, Ling; Guo, Chen; Wang, Feng; Zheng, Sen; Liu, Chun-Zhao

    2011-11-01

    A simple and rapid harvesting method by in situ magnetic separation with naked Fe(3)O(4) nanoparticles has been developed for the microalgal recovery of Botryococcus braunii and Chlorella ellipsoidea. After adding the magnetic particles to the microalgal culture broth, the microalgal cells were adsorbed and then separated by an external magnetic field. The maximal recovery efficiency reached more than 98% for both microalgae at a stirring speed of 120 r/min within 1 min, and the maximal adsorption capacity of these Fe(3)O(4) nanoparticles reached 55.9 mg-dry biomass/mg-particles for B. braunii and 5.83 mg-dry biomass/mg-particles for C. ellipsoidea. Appropriate pH value and high nanoparticle dose were favorable to the microalgae recovery, and the adsorption mechanism between the naked Fe(3)O(4) nanoparticles and the microalgal cells was mainly due to the electrostatic attraction. The developed in situ magnetic separation technology provides a great potential for saving time and energy associated with improving microalgal harvesting. PMID:21890346

  20. Separation Nanotechnology of Diethylenetriaminepentaacetic Acid Bonded Magnetic Nanoparticles for Spent Nuclear Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Maninder [Idaho Univ., Moscow, ID (United States); Johnson, Andrew [Idaho Univ., Moscow, ID (United States); Tian, Guoxin [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Jiang, Weilin [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Rao, Linfeng [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Paszczynski, Andrzej [Idaho Univ., Moscow, ID (United States); Qiang, You [Center for Advanced Energy Studies, Idaho Falls, ID (United States); Idaho Univ., Moscow, ID (United States)

    2013-01-01

    A nanomagnetic separation method based on Diethylenetriaminepentaacetic acid (DTPA) conjugated with magnetic nanoparticles (MNPs) is studied for application in spent nuclear fuel separation. The high affinity of DTPA towards actinides aids in separation from the highly acidic medium of nuclear waste. The solubility and magnetization of particles at low pH is protected by encapsulating them in silica layer. Surface functionalization of silica coated particles with polyamines enhances the loading capacity of the chelators on MNPs. The particles were characterized before and after surface modification using transmission electron microscopy (TEM), helium ion microscopy (HIM), Fourier transform-infrared (FT-IR) spectrometry, and X-ray diffractometry. The coated and uncoated samples were studied using vibrating sample magnetometer (VSM) to understand the change in magnetic properties due to the influence of the surface functionalization. The hydrodynamic size and surface charge of the particles are investigated using Dynamic Light Scattering (DLS). The uptake behavior of Am(III), Pu(IV), U(VI), and Np(V) from 0.1M NaNO3 solution was investigated. The sorption result shows the strong affinity of DTPA towards Am(III) and Pu(IV) by extracting 97% and 80% of actinides, respectively. The high removal efficiency and fast uptake of actinides make the chelator conjugated MNPs an effective method for spent nuclear fuel separation.

  1. Challenge to the volume reduction of contaminated soil based on magnetic separation

    International Nuclear Information System (INIS)

    A great amount of radioactive substances were released in the neighborhood of Fukushima Daiichi Nuclear Power Station following the accident of this plant. In particular, damage from radioactive cesium (134 or 137) has become the main case of trouble, incurring the necessity of decontamination of soil in the contaminated territory. In addition, a large amount of contaminated soil was generated due to the decontamination work, and its volume reduction has become a large challenge for the management and storage. This paper takes up magnetic separation technology as one of the technologies of volume reduction, and introduces its development condition. In this method, soil is firstly classified by size, and clay (or silt) with small particles, which adsorbs about 80% of radioactive cesium in soil, is separated from sand gravel. Furthermore, this clay portion is separated based on magnetic separation to 1:1 type and 1:2 type clay minerals with different magnetic susceptibilities, for the purpose of volume reduction. This paper describes the principle of the above method, as well as the development history to date. (A.O.)

  2. Separation Nanotechnology of Diethylenetriaminepentaacetic Acid Bonded Magnetic Nanoparticles for Spent Nuclear Fuel

    International Nuclear Information System (INIS)

    A nanomagnetic separation method based on Diethylenetriaminepentaacetic acid (DTPA) conjugated with magnetic nanoparticles (MNPs) is studied for application in spent nuclear fuel separation. The high affinity of DTPA towards actinides aids in separation from the highly acidic medium of nuclear waste. The solubility and magnetization of particles at low pH is protected by encapsulating them in silica layer. Surface functionalization of silica coated particles with polyamines enhances the loading capacity of the chelators on MNPs. The particles were characterized before and after surface modification using transmission electron microscopy (TEM), helium ion microscopy (HIM), Fourier transform-infrared (FT-IR) spectrometry, and X-ray diffractometry. The coated and uncoated samples were studied using vibrating sample magnetometer (VSM) to understand the change in magnetic properties due to the influence of the surface functionalization. The hydrodynamic size and surface charge of the particles are investigated using Dynamic Light Scattering (DLS). The uptake behavior of Am(III), Pu(IV), U(VI), and Np(V) from 0.1M NaNO3 solution was investigated. The sorption result shows the strong affinity of DTPA towards Am(III) and Pu(IV) by extracting 97% and 80% of actinides, respectively. The high removal efficiency and fast uptake of actinides make the chelator conjugated MNPs an effective method for spent nuclear fuel separation.

  3. On-chip micro-electromagnets for magnetic-based bio-molecules separation

    Energy Technology Data Exchange (ETDEWEB)

    Ramadan, Qasem E-mail: qasem@pmail.ntu.edu.sg; Samper, Victor; Poenar, Daniel; Yu Chen

    2004-10-01

    This paper reports a comprehensive theoretical, finite element and measurement analysis of different designs of planar micro-electromagnets for bio-molecular manipulation. The magnetic field due to current flowing in complex shapes of current-carrying conductors have been calculated analytically, simulated using finite-element analysis (FEA), and measured using the superconducting quantum interference device technique (SQUID). A comparison of the theoretical and measured magnetic field strength and patterns is presented. The planar electromagnets have been fabricated using patterned Al 2 {mu}m thick. The aim of the study is to explore and optimize the geometrical and structural parameters of planar electromagnets that give rise to the highest magnetic fields and forces for magnetic micro-beads manipulation. Magnetic beads are often used in biochemical assays for separation of bio-molecules. Typical beads are 0.2-10 {mu}m in diameter and have superparamagnetic properties. Increasing the intensity of the magnetic field generated by a coil by injection a larger current is not the most suitable solution as the maximum current is limited by Joule heating. Consequently, in order to maximize the field for a given current, one should optimize the geometry of the coil, as this is an extremely significant factor in determining the magnetic field intensity in 2D planar designs. The theoretical and measured results of this work show that the meander micro-electromagnet with mesh-shaped winding profile produces the strongest magnetic field (about 2.7 {mu}T for a current intensity of 6 mA) compared with other meander designs, such as the serpentine and rosette-shaped ones. The magnetic fields of these three types of meander-shaped micro-electromagnets were compared theoretically with that produced by a spiral micro-electromagnet whose technological realization is more complicated and costly due to the fact that it requires an additional insulation layer with a contact window and a second patterned metal layer as a via. Nevertheless, the spiral design produces a much stronger magnetic field up to five times larger than that of the mesh-shaped micro-electromagnet for the same current and electromagnet area. The measured results strongly agree with these conclusions resulted from the theoretical analysis. The results presented in this paper provide a solid and useful basis for the design of a micro-fluidic bio-molecule separation and detection system using magnetic fields and magnetic beads.

  4. Development and creation of the electromagnetic separator for isotope separation in the system of opposing axisymmetric magnetic fields with two fields reversed

    International Nuclear Information System (INIS)

    The paper reports the results of work on creation of a setup for isotope separation in the system of opposing axisymmetric magnetic fields with two field reverses. Consideration is given to a real possibility of improving the efficiency of the electromagnetic separator and its resolving power in the double-reverse magnetic field system. It is demonstrated that the use of the opposing axisymmetric field system may substantially reduce the energy consumption during the process of isotope separation. The estimated magnetic field of the facility attests to a possibility of molybdenum isotope separation and isolation of high-purity 98Mo and 100Mo isotopes required for production of the 99Mo/99Tc generator, most widely used in modern medicine.

  5. Treatment of heavy metals and radionuclides in groundwater and wastewater by magnetic separation

    International Nuclear Information System (INIS)

    Removal of trace quantities of heavy metal or radionuclide contamination from solutions at high flow rate presents a considerable technical challenge. Low flow methods of treatment such as particle gravity settling require expensive large volume equipment, whereas traditional methods of filtration demand significant energy costs. Magnetic filtration can be used to provide a low cost method of solid-liquid separation at high flow rate, provided contaminants can be selectively bound to a magnetic solid particle. This paper describes recent progress with this technique including performance tests of composite materials produced to selectively remove specific contaminants such as cesium, uranium, lead, cadmium, and mercury from solution

  6. Review and evaluation of extractants for strontium removal using magnetically assisted chemical separation

    International Nuclear Information System (INIS)

    A literature review on extractants for strontium removal was initially performed at Northern Illinois University to assess their potential in magnetically assisted chemical separation. A series of potential strontium extractants was systematically evaluated there using radioanalytical methods. Initial experiments were designed to test the uptake of strontium from nitric acid using several samples of magnetic extractant particles that were coated with various crown ether ligands. High partition coefficient (Kd) values for stimulant tank waste were obtained. Further studies demonstrated that the large partitioning was due to uncoated particles

  7. Review and evaluation of extractants for strontium removal using magnetically assisted chemical separation

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, C.B.; Rogers, R.D. [Northern Illinois Univ., De Kalb, IL (United States). Dept. of Chemistry; Nunez, L.; Ziemer, M.D.; Pleune, T.T.; Vandegrift, G.F. [Argonne National Lab., IL (United States)

    1995-11-01

    A literature review on extractants for strontium removal was initially performed at Northern Illinois University to assess their potential in magnetically assisted chemical separation. A series of potential strontium extractants was systematically evaluated there using radioanalytical methods. Initial experiments were designed to test the uptake of strontium from nitric acid using several samples of magnetic extractant particles that were coated with various crown ether ligands. High partition coefficient (K{sub d}) values for stimulant tank waste were obtained. Further studies demonstrated that the large partitioning was due to uncoated particles.

  8. Combined performance of biochar sorption and magnetic separation processes for treatment of chromium-contained electroplating wastewater.

    Science.gov (United States)

    Wang, Sheng-ye; Tang, Yan-kui; Li, Kun; Mo, Ya-yuan; Li, Hao-feng; Gu, Zhan-qi

    2014-12-01

    Magnetic biochar was prepared with eucalyptus leaf residue remained after essential oil being extracted. Batch experiments were conducted to examine the capacity of the magnetic biochar to remove Cr (VI) from electroplating wastewater and to be separated by an external magnetic field. The results show that the initial solution pH plays an important role on both sorption and separation. The removal rates of Cr (VI), total Cr, Cu (II), and Ni (II) were 97.11%, 97.63%, 100% and 100%, respectively. The turbidity of the sorption-treated solution was reduced to 21.8NTU from 4075NTU after 10min magnetic separation. The study also confirms that the magnetic biochar still retains the original magnetic separation performance after the sorption process. PMID:25463783

  9. Satellite Observations of Separator Line Geometry of Three-Dimensional Magnetic Reconnection

    CERN Document Server

    Xiao, C J; Pu, Z Y; Ma, Z W; Zhao, H; Zhou, G P; Wang, J X; Kivelson, M G; Fu, S Y; Liu, Z X; Zong, Q G; Dunlop, M W; Glassmeier, K-H; Lucek, E; Reme, H; Dandouras, I; Escoubet, C P

    2007-01-01

    Detection of a separator line that connects magnetic nulls and the determination of the dynamics and plasma environment of such a structure can improve our understanding of the three-dimensional (3D) magnetic reconnection process. However, this type of field and particle configuration has not been directly observed in space plasmas. Here we report the identification of a pair of nulls, the null-null line that connects them, and associated fans and spines in the magnetotail of Earth using data from the four Cluster spacecraft. With di and de designating the ion and electron inertial lengths, respectively, the separation between the nulls is found to be ~0.7di and an associated oscillation is identified as a lower hybrid wave with wavelength ~ de. This in situ evidence of the full 3D reconnection geometry and associated dynamics provides an important step toward to establishing an observational framework of 3D reconnection.

  10. Local magneto-electric effects from separate areas of magnetic domains of yttrium iron garnets

    Energy Technology Data Exchange (ETDEWEB)

    Koronovskyy, Vadim; Gorchinskii, Nikolai [Department of Radiophysics, Taras Shevchenko Kiev National University, 2, Prospekt Glushkova Street, 03127 Kiev (Ukraine)

    2011-12-15

    Magneto-electric properties (electromagneto-optical effect (EMOE)) of separate magnetic domains of yttrium iron garnets (YIGs) are investigated with using an optical polarimetry method. This local effect depends on the chosen point of optical scanning and changes essentially at scanning of various points of the domain. We have revealed separate sites of YIG sample where sharp changes of the electromagneto-optical (EMO) signal concerning average value in the domain are registered. We assume that the defect area (or its vicinity) on a surface or in volume of the investigated YIG sample causes the specified changes of EMO effect value. When probing by thin laser beam various sites of the magnetic domain, it is possible to define the defects positions by EMO signal value and it can matter for applications. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Separated magnet yoke for permanent magnet linear generator for marine wave energy converters

    OpenAIRE

    Gargov, NP; Zobaa, AF; Pisica, I

    2014-01-01

    In this paper the performance of a longitudinal flux permanent magnet linear generator (PMLG) for wave energy converters (WEC) is investigated. The influence of the number of slots per pole, phase q and the number of stator's winding sections are analysed. The power output and the cogging forces in the PMLG are calculated and reviewed with respect to the above design parameters. In addition, an optimised PMLG model is designed and simulated. Three-dimensional Finite Element Method (FEM) is us...

  12. Single-step synthesis and magnetic separation of graphene and carbon nanotubes in arc discharge plasmas

    Science.gov (United States)

    Volotskova, O.; Levchenko, I.; Shashurin, A.; Raitses, Y.; Ostrikov, K.; Keidar, M.

    2010-10-01

    The unique properties of graphene and carbon nanotubes made them the most promising nanomaterials attracting enormous attention, due to the prospects for applications in various nanodevices, from nanoelectronics to sensors and energy conversion devices. Here we report on a novel deterministic, single-step approach to simultaneous production and magnetic separation of graphene flakes and carbon nanotubes in an arc discharge by splitting the high-temperature growth and low-temperature separation zones using a non-uniform magnetic field and tailor-designed catalyst alloy, and depositing nanotubes and graphene in different areas. Our results are very relevant to the development of commercially-viable, single-step production of bulk amounts of high-quality graphene.The unique properties of graphene and carbon nanotubes made them the most promising nanomaterials attracting enormous attention, due to the prospects for applications in various nanodevices, from nanoelectronics to sensors and energy conversion devices. Here we report on a novel deterministic, single-step approach to simultaneous production and magnetic separation of graphene flakes and carbon nanotubes in an arc discharge by splitting the high-temperature growth and low-temperature separation zones using a non-uniform magnetic field and tailor-designed catalyst alloy, and depositing nanotubes and graphene in different areas. Our results are very relevant to the development of commercially-viable, single-step production of bulk amounts of high-quality graphene. Electronic supplementary information (ESI) available: Details of the setup and process; details on the micro-Raman, TEM, SEM, AFM, and characterization of the carbon deposits in different collection areas; detailed description of the results obtained by micro-Raman, AFM and electron diffraction techniques. See DOI: 10.1039/c0nr00416b

  13. Magnetically Separable Base Catalysts: Heterogeneous Catalysis vs. Quasi-Homogeneous Catalysis

    OpenAIRE

    Raed Abu-Reziq; Howard Alper

    2012-01-01

    The synthesis of magnetically separable quasi-homogeneous base catalyst and heterogeneous base catalyst is described. The quasi-homogeneous catalyst is achieved by supporting silane monomers functionalized with different amine groups directly on the surface of magnetite nanoparticles. The heterogeneous catalyst is prepared via a sol-gel process in which silane monomers containing different amine groups are copolymerized with tetraethoxysilane in the presence of magnetite nanoparticles functio...

  14. Rock Magnetic Mineral Assemblage in Mineral Separates from Xenoliths of Continental Lithospheric Mantle

    Science.gov (United States)

    Khakhalova, E.; Feinberg, J. M.; Ionov, D. A.; Ferre, E. C.; Friedman, S. A.; Hernandez, F. M.; Neal, C. R.; Conder, J. A.

    2014-12-01

    Studies of aeromagnetic anomalies suggest that the lithospheric mantle may contribute to long wavelength features. Examination of unaltered mantle xenoliths may reveal the mineralogical sources of these aeromagnetic anomalies. Prior work has reported microscopic inclusions of magnetic minerals in mantle silicates. Here we explore the magnetism of pure olivine, clinopyroxene, orthopyroxene, and spinel separated from peridotite xenoliths from the Dariganga and Tariat localities in Mongolia that sample the lithospheric mantle. All separates were leached with HF and HCl to remove secondary minerals adhering to the surface of the grains or in cracks. Separates were then mounted in cement to create monomineralic specimens for investigation using hysteresis loops, first order reversal curves (FORC), alternating field and thermal demagnetization of a 1T IRM, and low-temperature magnetometry. All specimens showed trace concentrations of ferromagnetic inclusions with Ms values of ~10-3 Am2kg-1. Thermal demagnetization showed a range of unblocking temperatures with median destructive temperatures of 300-400C. Two specimens showed a dramatic demagnetization at 585C, consistent with pure magnetite (Mt). The presence of Mt was confirmed by observations of the Verwey transition at 100-120K and by backfield remanence acquisition curves that plateau at ~300 mT. The median destructive alternating field was ~20 mT and 40-80 mT for specimens from Dariganga and Tariat, respectively. FORC diagrams show single-domain-like behavior with a median Hc of ~20 mT. The demagnetization experiments suggest that Mt inclusions in the lattice of olivine, opx, cpx and spinel carry magnetic remanence. Thus, the lithospheric mantle may exhibit in-situ ferromagnetism carried by Mt below 585C. The magnetization of separates varies between xenolith localities but is consistent amongst minerals of the same locality. Future work will address whether the Mt formed before or during xenolith ascent.

  15. Multilevel (3D) microfluidic technology for an innovative magnetic cell separation and couting platform

    OpenAIRE

    Fouet, Marc; Manczak, R; Manczak, Rmi; Courson, Rmi; Blatch, Charline; Reybier, K; Gu, Anne-Marie

    2014-01-01

    Currently, the technique for the quantitative detection of cells is flow cytometry. This technique has the advantage of being sensitive and reliable but is expensive, time consuming and not suited to both routine screening and point?of?care diagnostics. Miniaturized cell separation devices offer many advantages such as the use of small volumes, portability and low cost.We propose a new concept of device which, by combining 3D fluid engineering and localized magnetic actuation, enables the ful...

  16. Spin-Charge Separation in Two-dimensional Frustrated Quantum Magnets

    CERN Document Server

    Laeuchli, A

    2004-01-01

    The dynamics of a mobile hole in two-dimensional frustrated quantum magnets is investigated by exact diagonalization techniques. Our results provide evidence for spin-charge separation upon doping the kagome lattice, a prototype of a spin liquid. In contrast, in the checkerboard lattice, a symmetry broken Valence Bond Crystal, a small quasi-particle peak is seen for some crystal momenta, a finding interpreted as a restoration of weak holon-spinon confinement.

  17. Tailored functionalization of iron oxide nanoparticles for MRI, drug delivery, magnetic separation and immobilization of biosubstances.

    Science.gov (United States)

    Hola, Katerina; Markova, Zdenka; Zoppellaro, Giorgio; Tucek, Jiri; Zboril, Radek

    2015-11-01

    In this critical review, we outline various covalent and non-covalent approaches for the functionalization of iron oxide nanoparticles (IONPs). Tuning the surface chemistry and design of magnetic nanoparticles are described in relation to their applicability in advanced medical technologies and biotechnologies including magnetic resonance imaging (MRI) contrast agents, targeted drug delivery, magnetic separations and immobilizations of proteins, enzymes, antibodies, targeting agents and other biosubstances. We review synthetic strategies for the controlled preparation of IONPs modified with frequently used functional groups including amine, carboxyl and hydroxyl groups as well as the preparation of IONPs functionalized with other species, e.g., epoxy, thiol, alkane, azide, and alkyne groups. Three main coupling strategies for linking IONPs with active agents are presented: (i) chemical modification of amine groups on the surface of IONPs, (ii) chemical modification of bioactive substances (e.g. with fluorescent dyes), and (iii) the activation of carboxyl groups mainly for enzyme immobilization. Applications for drug delivery using click chemistry linking or biodegradable bonds are compared to non-covalent methods based on polymer modified condensed magnetic nanoclusters. Among many challenges, we highlight the specific surface engineering allowing both therapeutic and diagnostic applications (theranostics) of IONPs and magnetic/metallic hybrid nanostructures possessing a huge potential in biocatalysis, green chemistry, magnetic bioseparations and bioimaging. PMID:25689073

  18. Characterization of steel grit recovered from ornamental rocks waste by magnetic separation; Caracterizacao da granalha de aco recuperada do residuo de rochas ornamentais por separacao magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Junca, E.; Telles, V.B.; Rodrigues, G.F.; Oliveira, J.R. de; Tenorio, J.A.S., E-mail: eduardojunca@gmail.co [Universidade de Sao Paulo (USP), SP (Brazil). Dept. de Engenharia Metalurgica e de Materiais; Instituto Federal de Ciencia e Tecnologia do Espirito Santo (IFES), Vitoria, ES (Brazil)

    2010-07-01

    The aim of this work is characterization of steel grit recovered from ornamental rock waste by magnetic separation. The magnetic separation was realized in three steps: first, using a high intensity wet magnetic separator, which used only the remaining magnetic field of equipment. In the second step, the magnetic material obtained in the first phase was subjected to a new manual magnetic separation using rare earth magnets. In a third step, magnetic material obtained with rare earth magnets was subjected to manual magnetic separation using ferrite magnets. After the magnetic separation, the material was sent to characterization which was obtained by chemical analysis, scanning electron microscopy, X-ray diffraction and size analysis. The size analysis showed that the concentrate range from 0,5 to 563,67 {mu}m with 4 wt.% over 100 {mu}m and content metallic iron of 93 wt%. (author)

  19. Superconducting magnet system of in-flight separator for a heavy ion accelerator planned in Korea

    International Nuclear Information System (INIS)

    An in-flight fragment separator, which aims to produce and study rare isotopes, consists of superferric quadrupole triplets and dipole magnets to focus and bend the beams for achromatic focusing and momentum dispersion, respectively. The separator is divided into pre and main stages, and we plan to use superconducting magnets employing high-Tc superconductor (HTS) coils in the pre-separator area, where radiation heating is high. The HTS coils will be cooled by cold He gas in 20-50 K, and in the other area, superferric magnets using low-temperature superconductor (LTS) will be used at 4 K. A few LTS coils were wound and successfully tested in a LHe dewar, and the design of cryostat has been optimized. Development of the HTS coils is ongoing in collaboration with a group at KERI. An HTS coil of racetrack shape was wound and tested in a bath and in a dewar with cryocooler. No degradation on critical current due to coil winding was found

  20. Superconducting magnet system of in-flight separator for a heavy ion accelerator planned in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. W.; Kim, D. G.; Jo, H. C. [Institute for Basic Science, Daejeon (Korea, Republic of); Choi, Y. S. [Korea Basic Science Institute, Daejeon (Korea, Republic of); Kim, S. H. [Changwon National University, Changwon (Korea, Republic of); Sim, K. D.; Sohn, M. H. [Korea Electrotechnology Research Institute, Changwon (Korea, Republic of)

    2015-03-15

    An in-flight fragment separator, which aims to produce and study rare isotopes, consists of superferric quadrupole triplets and dipole magnets to focus and bend the beams for achromatic focusing and momentum dispersion, respectively. The separator is divided into pre and main stages, and we plan to use superconducting magnets employing high-Tc superconductor (HTS) coils in the pre-separator area, where radiation heating is high. The HTS coils will be cooled by cold He gas in 20-50 K, and in the other area, superferric magnets using low-temperature superconductor (LTS) will be used at 4 K. A few LTS coils were wound and successfully tested in a LHe dewar, and the design of cryostat has been optimized. Development of the HTS coils is ongoing in collaboration with a group at KERI. An HTS coil of racetrack shape was wound and tested in a bath and in a dewar with cryocooler. No degradation on critical current due to coil winding was found.

  1. Characterization of magnetic ion-exchange composites for protein separation from biosuspensions.

    Science.gov (United States)

    Kppler, Tobias E; Hickstein, Birgit; Peuker, Urs A; Posten, Clemens

    2008-06-01

    Downstream processing is a major issue in biotechnological production. A multitude of unit operations with nonsatisfying yield are often used to reach the desired product purity. Direct recovery technologies such as high-gradient magnetic fishing (HGMF) are advantageous because of their ability to separate the desired product in early stages from crude cultivation broths. However, the use of magnetic particles to capture valuable biotechnological products is often linked to the drawback that support particles are expensive and not available in greater quantities. This current work presents new composite magnetic particles that can be used in biotechnology. They are manufactured by a spray drying process. During this process, the nanosized magnetite particles as well as functional ion-exchange nanoparticles are integrated into one particle in which they are linked by a matrix polymer. The production procedure is flexible, scalable, and therefore economical. These particles have good adsorption capacities of up to 85 mg/g adsorbed protein and good binding kinetics. They are resistant to harsh conditions such as short ultrasonic treatment or extreme pHs. In order to test their usefulness in biosuspensions, model proteins were separated using these particles. The anion and cation exchanger particles separated lysozyme (LZ) or BSA from cultivation suspensions. The selectivity of recovery was dependent on other proteins present as is usual for ion-exchange binding mechanisms. PMID:18640596

  2. Recovery of iron from vanadium tailings with coal-based direct reduction followed by magnetic separation.

    Science.gov (United States)

    Yang, Huifen; Jing, Lili; Zhang, Baogang

    2011-01-30

    A technique with coal-based direct reduction followed by magnetic separation is presented in this study for recovering and reusing iron otherwise wasted in vanadium tailings. Process parameters such as usage of additives, tailings/reductant/additives ratio, reduction temperature and time, as well as particle size were experimentally determined. The optimum process parameters were proposed as follows: using lime as the additive, lignite as the reductant, weight ratios of vanadium tailings/lignite/lime at 100:30:10, reduction roasting at 1200 C for 60 min, and particle size of 98% less than 30 ?m in the final roasted product feeding to magnetic separation. Under these conditions, a magnetic concentrate containing 90.31% total iron and 89.76% metallization iron with a total iron recovery rate of 83.88% was obtained. In addition, mineralography of vanadium tailings, coal-based reduction product and magnetic concentrate were studied by X-ray powder diffraction technique (XRD). The microstructures of above products were analyzed by scanning electron microscope (SEM) to help understand the mechanism. PMID:21071144

  3. Recovery of iron from vanadium tailings with coal-based direct reduction followed by magnetic separation

    International Nuclear Information System (INIS)

    A technique with coal-based direct reduction followed by magnetic separation is presented in this study for recovering and reusing iron otherwise wasted in vanadium tailings. Process parameters such as usage of additives, tailings/reductant/additives ratio, reduction temperature and time, as well as particle size were experimentally determined. The optimum process parameters were proposed as follows: using lime as the additive, lignite as the reductant, weight ratios of vanadium tailings/lignite/lime at 100:30:10, reduction roasting at 1200 deg. C for 60 min, and particle size of 98% less than 30 ?m in the final roasted product feeding to magnetic separation. Under these conditions, a magnetic concentrate containing 90.31% total iron and 89.76% metallization iron with a total iron recovery rate of 83.88% was obtained. In addition, mineralography of vanadium tailings, coal-based reduction product and magnetic concentrate were studied by X-ray powder diffraction technique (XRD). The microstructures of above products were analyzed by scanning electron microscope (SEM) to help understand the mechanism.

  4. Mineralogy and heavy metal leachability of magnetic fractions separated from some Chinese coal fly ashes.

    Science.gov (United States)

    Lu, S G; Chen, Y Y; Shan, H D; Bai, S Q

    2009-09-30

    Magnetic fractions (MFs) in fly ashes from eight coal-burning power plants were extracted by magnetic separation procedure. Their mineralogy and potential leachability of heavy metals were analyzed using rock magnetism, X-ray diffraction (XRD), scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM/EDX) and leaching procedures (toxicity characteristics leaching procedure by the United States Environmental Protection Agency, TCLP, and gastric juice simulation test, GJST). Results show that the MFs in the fly ashes range between 2.2 and 16.3wt%, and are generally composed of magnetite, hematite, quartz and mullite. Thermomagnetic analysis and SEM/EDX indicate that the main magnetic carrier magnetite is substituted with small amounts of impure ions, and its structures are featured by rough, dendritic and granular iron spherules. The MFs are found to be rich in Fe, Mn, Cr, Cu, Cd and Pb. Compared with the non-magnetic fractions (NMFs), the MFs have about 5 times higher iron, and 1.6 times higher Mn, Cr, Cu and Cd concentrations. The TCLP test shows that the TCLP-extractable Cr, Cu, and Pb concentrations in the MFs are higher than those in the NMFs, while the TCLP-extractable Cd concentration in the MFs and NMFs is below the detection limit (Cr>Pb>Cd. The heavy metals of fly ashes have a great potential to be released into the environment under acid environment. PMID:19380201

  5. Magnetic design and field optimization of a superferric dipole for the RISP fragment separator

    Science.gov (United States)

    Zaghloul, A.; Kim, J. Y.; Kim, D. G.; Jo, H. C.; Kim, M. J.

    2015-10-01

    The in-flight fragment separator of the Rare Isotope Science Project requires eight dipole magnets to produce a gap field of 1.7 T in a deflection sector of 30 degree with a 6-m central radius. If the beam-optics requirements are to be met, an integral field homogeneity of a few units (1 unit = 10-4) must be achieved. A superferric dipole magnet has been designed by using the Low-Temperature Superconducting wire NbTi and soft iron of grade SAE1010. The 3D magnetic design and field optimization have been performed using the Opera code. The length and the width of the air slots in the poles have been determined in an optimization process that considered not only the uniformity of the field in the straight section but also the field errors in the end regions. The field uniformity has also been studied for a range of operation of the dipole magnet from 0.4 T to 1.7 T. The magnetic design and field uniformity are discussed.

  6. Removal and recycle of phosphate from treated water of sewage plants with zirconium ferrite adsorbent by high gradient magnetic separation

    International Nuclear Information System (INIS)

    Zirconium ferrite particles are good adsorbent for phosphate ions. Magnetic separation characteristics for removal of phosphate from treated water of sewage plants with the adsorbent have been studied to prevent eutrophication of semi-enclosed bay, e.g. the bay of Tokyo. Based on the adsorption for the phosphate ions and ferromagnetic properties of the zirconium ferrite adsorbent, high gradient magnetic separation characteristics with using superconducting magnet was discussed. Very rapid magnetic filtration velocity, i.e. 1m/s, and regeneration properties of the adsorbent indicate that the zirconium ferrite is the excellent adsorbent for phosphorus removal and recycle from treated water of large scale sewage plants.

  7. Chiral separation and chiral magnetic effects in a slab: the role of boundaries

    CERN Document Server

    Gorbar, E V; Shovkovy, I A; Sukhachov, P O

    2015-01-01

    We study the chiral separation and chiral magnetic effects in a slab of Dirac semimetal of finite thickness, placed in a constant magnetic field perpendicular to its surfaces. We utilize the Bogolyubov boundary conditions with a large Dirac mass outside the slab. We find that a finite thickness of the slab leads to a quantization of the axial current density, which is seen in its stepped shape dependence on the fermion chemical potential and a sawtooth shape dependence on the thickness of the slab. As expected, in the limit of a large thickness, the result reduces to the well known expression for the chiral separation effect. On the other hand, in the same slab geometry, we find that a nonzero chiral chemical potential induces no electric current, as might have been expected from the chiral magnetic effect. We argue that this outcome is natural and points to the truly non-static nature of the latter. By taking into account a nonzero electric field of double layer near the boundaries of the slab, we find that ...

  8. Separation and measurement of silver nanoparticles and silver ions using magnetic particles.

    Science.gov (United States)

    Mwilu, Samuel K; Siska, Emily; Baig, R B Nasir; Varma, Rajender S; Heithmar, Ed; Rogers, Kim R

    2014-02-15

    The recent surge in consumer products and applications using metallic nanoparticles has increased the possibility of human or ecosystem exposure due to unintentional release into the environment. To protect consumer health and the environment, there is an urgent need to develop tools that can characterize and quantify these materials at low concentrations and in complex matrices. In this study, magnetic nanoparticles coated with either dopamine or glutathione were used to develop a new, simple and reliable method for the separation/pre-concentration of trace amounts of silver nanoparticles followed by their quantification using inductively coupled plasma mass spectrometry (ICP-MS). The structurally modified magnetic particles were able to capture trace amounts of silver nanoparticles (~2 ppb) and concentrate (up to 250 times) the particles for analysis with ICP-MS. Under laboratory conditions, recovery of silver nanoparticles was >99%. More importantly, the magnetic particles selectively captured silver nanoparticles in a mixture containing both nano-particulate and ionic silver. This unique feature addresses the challenges of separation and quantification of silver nanoparticles in addition to the total silver in environmental samples. Spiking experiments showed recoveries higher than 97% for tap water and both fresh and saline surface water. PMID:24295749

  9. Accessible and green manufacturing of magnetite (ferrous ferric oxide) nanocrystals and their use in magnetic separations

    Science.gov (United States)

    Yavuz, Cafer Tayyar

    This work describes the first size dependent magnetic separation in nanoscale. Magnetite (Fe3O4) nanocrystals of high quality and uniform size were synthesized with monodispersity below 10%. Magnetite nanocrystals of 4 nm to 33 nm (average diameter) were produced. Batch synthesis was shown to go up to 20 grams which is more than 10 times of a standard nanocrystal synthesis, without loosing the quality and monodispersity. Reactor design for mass (1 gram per hour) production of magnetite nanocrystals is reported for the first time. The cost of a kg of lab purity magnetite nanocrystals was shown to be 2600. A green synthesis that utilizes rust and edible oils was developed. The cost of a kg was brought down to 22. Size dependency of magnetism was shown in nanoscale for the first time. Reversible aggregation theory was developed to explain the low field magnetic separation and solution behavior of magnetite nanocrystals. Arsenic was removed from drinking water with magnetite nanocrystals 200 times better than commercial adsorbents. Silica coating was successfully applied to enable the known silica related biotechnologies. Magnetite-silica nanoshells were functionalized with amino groups. For the first time, silver was coated on the magnetite-silica nanoshells to produce triple multishells. Anti-microbial activity of multishells is anticipated.

  10. Magnetic particle separation technique: a reliable and simple tool for RIA/IRMA and quantitative PCR assay

    International Nuclear Information System (INIS)

    Five types of magnetic particles without or with aldehyde, amino and carboxyl functional groups, respectively were used to immobilize first or second antibody by three models, i. e. physical adsorption, chemical coupling and immuno-affinity, forming four types of magnetic particle antibodies. The second antibody immobilized on polyacrolein magnetic particles through aldehyde functional groups and the first antibodies immobilized on carboxylic polystyrene magnetic particles through carboxyl functional groups were recommended to apply to RIAs and/or IRMAs. Streptavidin immobilized on commercial magnetic particles through amino functional groups was successfully applied to separating specific PCR product for quantification of human cytomegalovirus. In the paper typical data on reliability of these magnetic particle ligands were reported and simplicity of the magnetic particle separation technique was discussed. The results showed that the technique was a reliable and simple tool for RIA/IRMA and quantitative PCR assay. (author)

  11. Three-dimensional modeling of a portable medical device for magnetic separation of particles from biological fluids

    International Nuclear Information System (INIS)

    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 (registered) . 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

  12. Magnetic-field-induced nematic-nematic phase separation and droplet formation in colloidal goethite

    International Nuclear Information System (INIS)

    We demonstrate the suitability of polarization microscopy to study the recently discovered (parallel) nematic-(perpendicular) nematic phase separation. This novel type of phase transition is induced by applying an external magnetic field to a nematic liquid crystal of boardlike colloidal goethite and is due to an interplay between the intrinsic magnetic properties of goethite and the collective effect of liquid crystal formation. It is shown that the intense ochre colour of goethite does not preclude the use of polarization microscopy and interference colours, and that dichroism can give valuable qualitative information on the nature of the phases, their anchoring and their sedimentation and order parameter profiles. We also apply these techniques to study 'nematic-nematic tactoids': nematic droplets sedimenting within a nematic medium with mutually perpendicular orientations.

  13. Preparation of quantum dot-coated magnetic polystyrene nanospheres for cancer cell labelling and separation

    Science.gov (United States)

    Chu, Maoquan; Song, Xin; Cheng, Duo; Liu, Shupeng; Zhu, Jian

    2006-07-01

    CdTe-coated magnetic polystyrene nanospheres (MPN) were prepared via a stepwise electrostatic self-assembly approach, and the conjugation of epidermal growth factor (EGF) to the MPN/CdTe core-shell nanocomposites was prepared by using 1-ethyl-3(3-dimethylamino propyl)-carbodiimide (EDC) as a cross-linking reagent. The MPN/CdTe and their bioconjugates yielded not only emitted bright fluorescence, but also exhibited superparamagnetism. The human breast cancer MDA-MB-435S cells could be labelled and rapidly separated by the MPN/CdTe-EGF bioconjugates. These magnetofluorescent nanospheres, consisting of magnetic spheres and quantum dots (QDs), may be of special interest for many biomedical applications.

  14. Deterministic Generation of Quantum State Transfer Between Spatially Separated Single Molecule Magnets

    International Nuclear Information System (INIS)

    We propose a new scheme for realizing deterministic quantum state transfer (QST) between two spatially separated single molecule magnets (SMMs) with the framework of cavity quantum electrodynamics (QED). In the present scheme, two SMMs are trapped in two spatially separated optical cavities coupled by an optical fiber. Through strictly numerically simulating, we demonstrate that our scheme is robust with respect to the SMMs' spontaneous decay and fiber loss under the conditions of dispersive SMMs-field interaction and strong coupling of cavity fiber. In addition, we also discuss the influence of photon leakage out of cavities and show that our proposal is good enough to demonstrate the generation of QST with high fidelity utilizing the current experimental technology. The present investigation provides research opportunities for realizing QST between solid-state qubits and may result in a substantial impact on the progress of solid-state-based quantum communications network. (general)

  15. Novel polydopamine imprinting layers coated magnetic carbon nanotubes for specific separation of lysozyme from egg white.

    Science.gov (United States)

    Gao, Ruixia; Zhang, Lili; Hao, Yi; Cui, Xihui; Liu, Dechun; Zhang, Min; Tang, Yuhai

    2015-11-01

    Novel core-shell nanocomposites, consisting of magnetic carbon nanotubes (MCNTs) core surrounded by a thin polydopamine (PDA) imprinting shell for specific recognition of lysozyme (Lyz), were fabricated for the first time. The obtained products were characterized and the results showed that the PDA layer was successfully attached onto the surface of MCNTs and the corresponding thickness of imprinting layer was just about 10nm which could enable the template access the recognition cavities easily. The polymerization conditions and adsorption performance of the resultant nanomaterials were investigated in detail. The results indicated that the obtained imprinted polymers showed fast kinetic and high affinity towards Lyz and could be used to specifically separate Lyz from real egg white. In addition, the prepared materials had excellent stability and no obvious deterioration after five adsorption-regeneration cycles. Easy preparation, rapid separation, high binding capacity, and satisfactory selectivity for the template protein make this polymer attractive in biotechnology and biosensors. PMID:26452937

  16. Steelmaking slag beneficiation by magnetic separator and impacts on sinter quality

    Directory of Open Access Journals (Sweden)

    Blkba?? .S.

    2014-01-01

    Full Text Available Basic oxygen furnaces (BOF slag is the main problem at all iron and steel factories. About more than 6 million tons/year of BOF slag has been accumulated from the waste stockyards in Turkey. Dumps slags can be revaluated by a processing technology which makes it possible to obtain products that meet the requirements of sintering and blast furnace production. The slags with particle size of -10 mm were enriched by the magnetic separator resulting and increase in Fe grade from 18% to 33%. The use of BOF slag in sinter blend provided additional Mn, CaO, MgO and introduced a good solution to environmental problems.

  17. Magnetically Separable Base Catalysts: Heterogeneous Catalysis vs. Quasi-Homogeneous Catalysis

    Directory of Open Access Journals (Sweden)

    Raed Abu-Reziq

    2012-03-01

    Full Text Available The synthesis of magnetically separable quasi-homogeneous base catalyst and heterogeneous base catalyst is described. The quasi-homogeneous catalyst is achieved by supporting silane monomers functionalized with different amine groups directly on the surface of magnetite nanoparticles. The heterogeneous catalyst is prepared via a sol-gel process in which silane monomers containing different amine groups are copolymerized with tetraethoxysilane in the presence of magnetite nanoparticles functionalized with ionic liquid moieties. The reactivity of the quasi-homogeneous and the heterogeneous base catalysts is compared in the nitroaldol condensation.

  18. Double-Layer Magnetic Nanoparticle-Embedded Silica Particles for Efficient Bio-Separation

    OpenAIRE

    Kyeong, San; Jeong, Cheolhwan; Kang, Homan; Cho, Hong-Jun; Park, Sung-Jun; Yang, Jin-Kyoung; Kim, Sehoon; Kim, Hyung-Mo; Jun, Bong-Hyun; Lee, Yoon-Sik

    2015-01-01

    Superparamagnetic Fe3O4 nanoparticles (NPs) based nanomaterials have been exploited in various biotechnology fields including biomolecule separation. However, slow accumulation of Fe3O4 NPs by magnets may limit broad applications of Fe3O4 NP-based nanomaterials. In this study, we report fabrication of Fe3O4 NPs double-layered silica nanoparticles (DL MNPs) with a silica core and highly packed Fe3O4 NPs layers. The DL MNPs had a superparamagnetic property and efficient accumulation kinetics un...

  19. Separation of Selenite from Inorganic Selenium Ions using TiO2 Magnetic Nanoparticles

    International Nuclear Information System (INIS)

    A simple and quick separation technique for selenite in natural water was developed using TiO2 SiO2/Fe3O4 nanoparticles. For the synthesis of nanoparticles, a polymer-assisted sol-gel method using hydroxypropyl cellulose (HPC) was developed to control particle dispersion in the synthetic procedure. In addition, titanium butoxide (TBT) precursor, instead of the typical titanium tetra isopropoxide, was used for the formation of the TiO2 shell. The synthesized nanoparticles were used to separate selenite (Se4+) in the presence of Se6+ or selenium anions for the photocatalytic reduction to Se0 atom on the TiO2 shell, followed by magnetic separation using Fe3O4 nanoparticles. The reduction efficiency of the photocatalytic reaction was 81.4% at a UV power of 6W for 3 h with a dark adsorption of 17.5% to the nanoparticles, as determined by inductively coupled plasma-mass spectrometry (ICP-MS). The developed separation method can be used for the speciation and preconcentration of selenium cations in environmental and biological analysis

  20. On the possibility of using neodymium-iron-boron magnets in gas centrifuges for uranium isotopes separation

    International Nuclear Information System (INIS)

    Aimed to decrease mass and dimensions of magnets in gas centrifuges, used for uranium isotope separation, it is suggested that barium ferrite magnets in a top magnetic suspension support (TMSS) be replaced with magnets made of a more high-energy Nd-Fe-B alloy. Experimental and calculated data point to the possibility of using Nd-Fe-B magnets (mass of 150-200 g) if the design of TMSS is optimized and the problems dealt with Nd-Fe-B alloy brittleness and corrosion susceptibility are solved

  1. Magnetic separation of amino acids by gold/iron-oxide composite nanoparticles synthesized by gamma-ray irradiation

    International Nuclear Information System (INIS)

    Amounts of amino acids adsorbed onto the Au/?-Fe2O3 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

  2. Method and apparatus for separating gases based on electrically and magnetically enhanced monolithic carbon fiber composite sorbents

    Science.gov (United States)

    Judkins, Roddie R. (9917 Rainbow Dr., Knoxville, TN 37922); Burchell, Timothy D. (109 Greywood Pl., Oak Ridge, TN 37830)

    1999-01-01

    A method for separating gases or other fluids involves placing a magnetic field on a monolithic carbon fiber composite sorption material to more preferentially attract certain gases or other fluids to the sorption material to which a magnetic field is applied. This technique may be combined with the known "pressure swing adsorption" technique utilizing the same sorption material.

  3. Theoretical study of moving magnetic beads on an inclined plane and its application in the ratchet separation technique

    Science.gov (United States)

    Rashidi, M. M.; Johnson, S.; Yang, Z.

    2016-01-01

    For first time, motion of a magnetic bead ascending an inclined surface is investigated. The translational and rotational velocities of magnetic beads traveling on an inclined plane in the creeping flow regime are studied. The governing equations considering lift force and magnetic torque are obtained. Rolling and slipping cases are studied in detail. It is shown that the lift force effect is critical for large values of sedimentation Reynolds number (Res) and negligible for small values of Res. This method is applicable for neutrally buoyant and heavy magnetic bead motion. Practical application of this study is implemented in the ratchet configuration for separation of magnetic beads with different sizes. This is applicable for novel applications such as drug delivery, magnetic tweezers, and magnetic actuated stiffness testing systems which require accurate magnetic bead sizes for accurate function.

  4. Mineralogy and heavy metal leachability of magnetic fractions separated from some Chinese coal fly ashes

    Energy Technology Data Exchange (ETDEWEB)

    Lu, S.G., E-mail: lusg@zju.edu.cn [College of Environmental and Resource Sciences, Zhejiang University, Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, Hangzhou 310029 (China); Chen, Y.Y. [Institute of Applied Biological Resources, Zhejiang University, Hangzhou 310029 (China); Shan, H.D.; Bai, S.Q. [College of Environmental and Resource Sciences, Zhejiang University, Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, Hangzhou 310029 (China)

    2009-09-30

    Magnetic fractions (MFs) in fly ashes from eight coal-burning power plants were extracted by magnetic separation procedure. Their mineralogy and potential leachability of heavy metals were analyzed using rock magnetism, X-ray diffraction (XRD), scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM/EDX) and leaching procedures (toxicity characteristics leaching procedure by the United States Environmental Protection Agency, TCLP, and gastric juice simulation test, GJST). Results show that the MFs in the fly ashes range between 2.2 and 16.3 wt%, and are generally composed of magnetite, hematite, quartz and mullite. Thermomagnetic analysis and SEM/EDX indicate that the main magnetic carrier magnetite is substituted with small amounts of impure ions, and its structures are featured by rough, dendritic and granular iron spherules. The MFs are found to be rich in Fe, Mn, Cr, Cu, Cd and Pb. Compared with the non-magnetic fractions (NMFs), the MFs have about 5 times higher iron, and 1.6 times higher Mn, Cr, Cu and Cd concentrations. The TCLP test shows that the TCLP-extractable Cr, Cu, and Pb concentrations in the MFs are higher than those in the NMFs, while the TCLP-extractable Cd concentration in the MFs and NMFs is below the detection limit (<0.1 mg/L). The GJST-extractable Cd, Cr, Cu, and Pb concentrations in the MFs are higher those in the NMFs. No significant difference in the leachability ratio of Cr, Cu and Pb with TCLP and GJST is found in the MFs and NMFs. However, the GJST test showed that Pb has higher leachability in MFs than that in NMFs. The leachability ratio of heavy metals has an order of Cu > Cr > Pb > Cd. The heavy metals of fly ashes have a great potential to be released into the environment under acid environment.

  5. A novel bubbling-assisted exfoliating method preparation of magnetically separable ?-Fe2O3/graphene recyclable photocatalysts

    Science.gov (United States)

    Zhang, Lili; Hu, Hongrui; Wu, Mingzai; Yu, Xinxin; Sun, Zhaoqi; Li, Guang; Liu, Xiansong; Zheng, Xiuwen

    2014-06-01

    A facile and novel bubbling-assisted exfoliating method was developed for the preparation of ?-Fe2O3/graphene composite, which showed desirable photocatalytic activity toward methyl orange with excellent cycling abilities and the possible growth mechanism was discussed. Photocatalytic and magnetic properties measurements show that the composite has excellent recyclable degradation efficiency and soft magnetic parameters, which makes the composite magnetically separable in a suspension system and can be recycled without significant loss of catalytic activity.

  6. Development program for magnetically assisted chemical separation: Evaluation of cesium removal from Hanford tank supernatant

    International Nuclear Information System (INIS)

    Magnetic particles (MAG*SEPSM) coated with various absorbents were evaluated for the separation and recovery of low concentrations of cesium from nuclear waste solutions. The MAG*SEPSM particles were coated with (1) clinoptilolite, (2) transylvanian volcanic tuff, (3) resorcinol formaldehyde, and (4) crystalline silico-titanate, and then were contacted with a Hanford supernatant simulant. Particles coated with the crystalline silico-titanate were identified by Bradtec as having the highest capacity for cesium removal under the conditions tested (variation of pH, ionic strength, cesium concentration, and absorbent/solution ratio). The MAG*SEPSM particles coated with resorcinol formaldehyde had high distribution ratios values and could also be used to remove cesium from Hanford supernant simulant. Gamma irradiation studies were performed on the MAG*SEPSM particles with a gamma dose equivalent to 100 cycles of use. This irradiation decreased the loading capacity and distribution ratios for the particles by greater than 75%. The particles demonstrated high sensitivity to radiolytic damage due to the degradation of the polymeric regions. These results were supported by optical microscopy measurements. Overall, use of magnetic particles for cesium separation under nuclear waste conditions was found to be marginally effective

  7. Removal and recovery of phosphorus in wastewater by superconducting high gradient magnetic separation with ferromagnetic adsorbent

    International Nuclear Information System (INIS)

    Prevention of eutrophication for semi-enclosed bays and ponds is serious and important challenge. In spite of the advanced wastewater treatment, typically 1 mg/L phosphorus is discharged into public water bodies from wastewater treatment plants. The total amount of the discharged water is so large that the further improvement of the removal efficiency of phosphorus in the discharged water is demanded. On the other hand, recently phosphorus has become increasingly recognized as the important strategic material due to the global food problem. Therefore, the recovery and recycling of phosphorus is also important issue. In this work, removal and recovery of phosphorus from treated wastewater by High Gradient Magnetic Separation (HGMS) with ferromagnetic zirconium ferrite adsorbent were studied. Phosphorus in the treated wastewater could be removed from 1.12 mg/L to 0.03 mg/L by the HGMS system with 500 mg/L zirconium ferrite adsorbent for 5 min in adsorption time. The magnetic separation speed achieved 1 m/s at 1 T which was necessary for practical use. We also confirmed that phosphorus could be desorbed from zirconium ferrite adsorbent by alkali treatment in a short time.

  8. Magnetic isotope effect and isotope separation under photolysis of dibenzylketone; dependence on viscosity and electron-nuclear interaction

    Energy Technology Data Exchange (ETDEWEB)

    Tarasov, V.F.; Askerov, D.B.; Buchachenko, A.L. (AN SSSR, Moscow. Inst. Khimicheskoj Fiziki)

    1982-09-01

    Dependence of effectiveness of magnetic isotope redistribution on the solvent mixture of glycerine and butanol viscosity is investigated on the example of dibenzylketone (DBK) photolysis. Changes in /sup 13/C isotope content in dibenzylketone molecules and dibenzyl molecules-DBK photolysis product are measured. It is shown that the stronger is the difference of effective electron-nuclear interactions in the magnetic and non-magnetic radical pairs the higher is the effectiveness of isotope separation. Isotope separation takes place more effectively at a certain, optimal viscosity of the solvent, in which the reaction proceeds.

  9. Effect of microwave irradiation on selective heating behavior and magnetic separation characteristics of Panzhihua ilmenite

    International Nuclear Information System (INIS)

    Highlights: Microwave irradiation can be applied effectively and efficiently to the irradiation processes of Panzhihua ilmenite. The mineral processing properties of microwave treated ilmenite were generally as good as or better than that of initial ilmenite. The microwave selective heating characteristics of the different minerals and compounds, and the thermal stresses were caused by the uniform heat rate disturbed under microwave irradiation. - Abstract: The influences of microwave irradiation on the surface characteristics of Panzhihua ilmenite were systematically investigated. The crystal structures, surface morphology and surface chemical functional groups of ilmenite were characterized before and after microwave irradiation and magnetic separation for different microwave treatment times by using various methods, such as XRD, SEM, and FT-IR, respectively. XRD analysis showed that the microwave treated ilmenite has the strongest peaks of phase more than that of raw samples, indicates that the crystalline compound of ilmenite increased with the microwave irradiation time. SEM analysis showed the micro-cracking appeared at many grain boundaries of ilmenite after being pretreated by microwave treatment. The separations of ilmenite from gangue minerals were completed and the micro-fissure within ilmenite minerals were also formed, which could be attributed to the microwave selective heating characteristics of the different minerals and compounds, and the thermal stresses were caused by the uniform heat rate disturbed under microwave irradiation. The mineral processing results showed that the magnetic separation characteristics and properties of microwave treated ilmenite samples were better than that of microwave untreated ilmenite samples. It was concluded that microwave irradiation can be applied effectively and efficiently to the irradiation processes of Panzhihua ilmenite

  10. Effect of microwave irradiation on selective heating behavior and magnetic separation characteristics of Panzhihua ilmenite

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Wei; Chen, Jin; Chang, Xiaodong; Guo, Shenghui [National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Srinivasakannan, C. [Chemical Engineering Program, The Petroleum Institute, Abu Dhabi, P.O. Box 253 (United Arab Emirates); Chen, Guo, E-mail: guochen@kmust.edu.cn [National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Chemical Engineering Program, The Petroleum Institute, Abu Dhabi, P.O. Box 253 (United Arab Emirates); Peng, Jinhui, E-mail: jhpeng@kmust.edu.cn [National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Chemical Engineering Program, The Petroleum Institute, Abu Dhabi, P.O. Box 253 (United Arab Emirates)

    2014-05-01

    Highlights: Microwave irradiation can be applied effectively and efficiently to the irradiation processes of Panzhihua ilmenite. The mineral processing properties of microwave treated ilmenite were generally as good as or better than that of initial ilmenite. The microwave selective heating characteristics of the different minerals and compounds, and the thermal stresses were caused by the uniform heat rate disturbed under microwave irradiation. - Abstract: The influences of microwave irradiation on the surface characteristics of Panzhihua ilmenite were systematically investigated. The crystal structures, surface morphology and surface chemical functional groups of ilmenite were characterized before and after microwave irradiation and magnetic separation for different microwave treatment times by using various methods, such as XRD, SEM, and FT-IR, respectively. XRD analysis showed that the microwave treated ilmenite has the strongest peaks of phase more than that of raw samples, indicates that the crystalline compound of ilmenite increased with the microwave irradiation time. SEM analysis showed the micro-cracking appeared at many grain boundaries of ilmenite after being pretreated by microwave treatment. The separations of ilmenite from gangue minerals were completed and the micro-fissure within ilmenite minerals were also formed, which could be attributed to the microwave selective heating characteristics of the different minerals and compounds, and the thermal stresses were caused by the uniform heat rate disturbed under microwave irradiation. The mineral processing results showed that the magnetic separation characteristics and properties of microwave treated ilmenite samples were better than that of microwave untreated ilmenite samples. It was concluded that microwave irradiation can be applied effectively and efficiently to the irradiation processes of Panzhihua ilmenite.

  11. Mass separation of a multi-component plasma flow travelling through a magnetic transport system

    Energy Technology Data Exchange (ETDEWEB)

    Paperny, V L; Krasov, V I [Physics Department, Irkutsk State University, Irkutsk, K. Marx Str., 1, 664003, Irkutsk (Russian Federation); Lebedev, N V; Astrakchantsev, N V [Institute for Physics and Technology, Irkutsk State Technical University, Irkutsk, Lermontov Str., 83, 664074, Irkutsk (Russian Federation)

    2011-06-15

    The travel of plasma flow produced by a dc arc through a transport system based on a curved magnetic field was studied. The characteristics of the system were the absence of a curved metallic plasma guiding duct ('open architecture') and the fact that the magnetic field coils were non-coaxial to the plasma flow. By means of Langmuir probe measurements it was shown that both shape and position of the cathode plasma flow at the exit of the transport system were governed by variation of currents of the magnetic coils as well as by biasing of a special electrode inserted into the plasma flow. It was found that with parameters of the transport system held constant, the plasma ions with lower m/Z were deflected more, e.g. Al ions were deflected more than Ti ions. For an arc with a composite cathode, consisting of mainly Cr-Fe-Ni, the profile of atoms of these elements at the exit of the transport system was measured by x-ray fluorescence spectrometry. The results obtained were consistent with the probe measurements, hence the transport system, in principle, may be used for spatial separation of a multi-component (in masses) plasma flow.

  12. Mass separation of a multi-component plasma flow travelling through a magnetic transport system

    International Nuclear Information System (INIS)

    The travel of plasma flow produced by a dc arc through a transport system based on a curved magnetic field was studied. The characteristics of the system were the absence of a curved metallic plasma guiding duct ('open architecture') and the fact that the magnetic field coils were non-coaxial to the plasma flow. By means of Langmuir probe measurements it was shown that both shape and position of the cathode plasma flow at the exit of the transport system were governed by variation of currents of the magnetic coils as well as by biasing of a special electrode inserted into the plasma flow. It was found that with parameters of the transport system held constant, the plasma ions with lower m/Z were deflected more, e.g. Al ions were deflected more than Ti ions. For an arc with a composite cathode, consisting of mainly Cr-Fe-Ni, the profile of atoms of these elements at the exit of the transport system was measured by x-ray fluorescence spectrometry. The results obtained were consistent with the probe measurements, hence the transport system, in principle, may be used for spatial separation of a multi-component (in masses) plasma flow.

  13. Adsorption mechanism of magnetically separable Fe3O4/graphene oxide hybrids

    Science.gov (United States)

    Ouyang, Ke; Zhu, Chuanhe; Zhao, Ya; Wang, Leichao; Xie, Shan; Wang, Qun

    2015-11-01

    A reclaimable Fe3O4/graphene oxide (GO) magnetic hybrid was successfully synthesized via a facile one-pot polyol approach and employed as a recyclable adsorbent for Bisphenol A (BPA) in aqueous solutions. The maximum adsorption capacity (qm) of the Fe3O4/GO hybrid for BPA was 72.80 mg/g at 273 K. The kinetics of the adsorption process and the adsorption isotherm data were fitted using the Freundlich equation and a pseudo-second-order kinetic model. The results of the thermodynamic parameters ?H, ?S and ?G showed that the adsorption process was exothermic and spontaneous. Furthermore, the reusability of the samples was investigated, and the results indicated that the samples exhibited high stability. The magnetic characterization demonstrated that hybrids were superparamagnetic and could be recovered conveniently by magnetic separation. The strong ?-? interaction was determined to be the predominant driving force behind the adsorption of BPA onto the Fe3O4/GO hybrid. Therefore, the Fe3O4/GO hybrid could be regarded as a potential adsorbent for wastewater treatment and purification processes.

  14. Development of high gradient magnetic separation system for removing the metallic wear debris to be present in highly viscous fluid

    International Nuclear Information System (INIS)

    In the industrial plants processing highly viscous fluid such as foods or industrial materials, there is an issue of contamination by metallic wear debris originating from pipe of manufacturing line. It is necessary to remove the metallic wear debris in highly viscous fluid, since these debris causes quality loss. In this study, we developed a high gradient magnetic separation system by using superconducting magnet to remove the metallic wear debris. The particle trajectory simulation and the magnetic separation experiment were conducted with polyvinyl alcohol as a model material. As a result, ca. 100% and 92.2% of the separation efficiency was achieved respectively for the highly viscous fluid of 1 Pa s and 6 Pa s in viscosity, with 14 and 30 mesh magnetic filters.

  15. Function of the demagnetization factor in respect of a quasi-solid filtermatrix of a magnetic separator ?????????????? ??? ???????????? ??????????????? ????????????? ??????-??????? ?????????? ??????????

    Directory of Open Access Journals (Sweden)

    Sandulyak Anna Aleksandrovna

    2013-07-01

    Full Text Available The author presents the prospects for the use of a magnetic separator, equipped with a filter matrix, in the treatment of ceramic suspensions and minerals. Particles of ferromagnetic impurities are captured by matrix pores, when purified media is transmitted through the magnetized filter matrix. The particle capture efficiency depends on the level of the filter matrix magnetization. The intensity of demagnetization influences the filter matrix magnetization intensity. Unfortunately, many researchers frequently ignore the demagnetization factor of a filter matrix as a specific (granulated magnet.The effect of self-demagnetization is studied in terms of homogeneous (solid magnets. The effect of self-demagnetization means that poles emerge on the borders of magnetized short magnets. Thus, a strong inner demagnetization field emerges. The main parameter of this physical characteristic of sample-magnets is the coefficient of demagnetization, which relates the intensity of the demagnetization field and the magnetization intensity of a sample body. The author considers the relevant issue of influence of the demagnetization intensity on the average values of the magnetic permeability of porous (quasi-solid magnets, for example, a filter matrix. This dependence is relevant for the calculation of magnetic permeability values.??????????? ?????????? ?????? ? ???????????? ??????? ????????????????? ??????? N ?? ??????? ???????? ????????? ????????????? ???????? ?????????? (??????-??????. ????????? ???????? N ? ??????????? ?? ????????? ????? L ????? ?????????? ? ?? ???????? D . ????????, ??? ?????? N ????? ????????? ???????????????? ????? ? ????????? ?????????????? ???????? (? L/D . ????????????? ????? ????????? ???????? ??????????? ???????? ????????? ????????????? ???????? ??????-??????? ? ??? ????? ?????? ? ?? ??????????????? ?????????????????.

  16. The selection of a matrix for the recovery of uranium by wet high-intensity magnetic separation

    International Nuclear Information System (INIS)

    The proper choice of a suitable matrix for high-intensity magnetic separation is of the utmost importance, since the geometry and size of the matrix play decisive roles in the achievement of optimum separation conditions. In relatively simple filtration applications, the matrix must offer a high efficiency of collision with suspended particles, a high probability of retention of intercepted particles, and high loading capacity. Also, it must be easily cleaned. The results obtained by the use of theoretical models of magnetic separation fail to agree with the experimental results for basic parameters like the ratio of particle size to matrix size, the length of the matrix, and the magnetic properties of the matrix material. Preconceived ideas about the matrix often lead to the erroneous choice of a matrix, and hence to its unsatisfactory performance during magnetic separation. The potential value of high-intensity magnetic separation as applied to the recovery of uranium and gold from leach residues and in association with the development of a large-scale magnetic separator to be used for the same purpose led to the present investigation in which a wide spectrum of matrix shapes and sizes were tested. It was found that the optimum recovery and selectivity of separation are obtained at a ratio of particle size to matrix-element size ranging from 200 to 300. The use of these matrices also results in a low degree of mechanical entrapment, particularly of coarser particles, for which straining plays a significant role for fine matrices. It was also found that the magnetization of a matrix plays a minor role, contrary to the theoretical predictions. Furthermore, the effects of matrix height, matrix loading, and scalping of the pulp by paramagnetic matrices were evaluated for various types of matrices

  17. Superconducting Open-Gradient Magnetic Separation for the Pretreatment of Radioactive or Mixed Waste Vitrification Feeds

    International Nuclear Information System (INIS)

    An open-gradient magnetic separation (OGMS) process is being considered to separate deleterious elements from radioactive and mixed waste streams prior to vitrification or stabilization. By physically segregating solid wastes and slurries based on the magnetic properties of the solid constituents, this potentially low-cost process may serve the U.S. Department of Energy (DOE) by reducing the large quantities of glass produced from defense-related high-level waste (HLW). Furthermore, the separation of deleterious elements from low-level waste (LLW) also can reduce the total quantity of waste produced in LLW immobilization activities. Many HLW 'and LLW waste' streams at both Hanford and the Savannah River Site (SRS) include constituents deleterious to the durability of borosilicate glass and the melter many of the constituents also possess paramagnetism. For example, Fe, Cr, Ni, and other transition metals may limit the waste loading and affect the durability of the glass by forming spine1 phases at the high operating temperature used in vitrification. Some magnetic spine1 phases observed in glass formation are magnetite (Fe,O,), chromite (FeCrO,), and others [(Fe, Ni, Mg, Zn, Mn)(Al, Fe, Ti, Cr)O,] as described elsewhere [Bates-1994, Wronkiewicz-1994]. Stable spine1 phases can cause segregation between the glass and the crystalline phases. As a consequence of the difference in density, the spine1 phases tend to accumulate at the bottom of the glass melter, which decreases the conductivity and melter lifetime [Sproull-1993]. Crystallization also can affect glass durability [Jantzen-1985, Turcotte- 1979, Buechele-1990] by changing the chemical composition of the matrix glass surrounding the crystals or causing stress at the glass/crystal interface. These are some of the effects that can increase leaching [Jantzen-1985]. A SRS glass that was partially crystallized to contain 10% vol. crystals composed of spinels, nepheline, and acmite phases showed minimal changes in short term leachability [Jantzen-1985, Hench-1982]. However, Jantzen et.al. found that leaching increased preferentially at grain boundary interfaces [Jantzen-1985]. For a SRL 165 glass crystallized up to 30% vol., leachability measured by normalized boron release increased by a factor of three compared to the uncrystallized glass [Kelly-1975, Plodinec-1979]. In general, the magnitude of the crystallization effect depends highly on glass composition and cooling rate

  18. Wave-driven rotation and mass separation in rotating magnetic mirrors

    Science.gov (United States)

    Fetterman, Abraham J.

    Axisymmetric mirrors are attractive for fusion because of their simplicity, high plasma pressure at a given magnetic pressure, and steady state operation. Their subclass, rotating mirrors, are particularly interesting because they have increased parallel confinement, magnetohydrodynamic stability, and a natural heating mechanism. This thesis finds and explores an unusual effect in supersonically rotating plasmas: particles are diffused by waves in both potential energy and kinetic energy. Extending the alpha channeling concept to rotating plasmas, the alpha particles may be removed at low energy through the loss cone, and the energy lost may be transferred to the radial electric field. This eliminates the need for electrodes in the mirror throat, which have presented serious technical issues in past rotating plasma devices. A high azimuthal mode number perturbation on the magnetic field is a particularly simple way to achieve the latter effect. In the rotating frame, this perturbation is seen as a wave near the alpha particle cyclotron harmonic, and can break the azimuthal symmetry and magnetic moment conservation without changing the particles total energy. The particle may exit if it reduces its kinetic energy and becomes more trapped if it gains kinetic energy, leading to a steady state current that maintains the field. Simulations of single particles in rotating mirrors show that a stationary wave can extract enough energy from alpha particles for a reactor to be self-sustaining. In the same way, rotation can be produced in non-fusion plasmas. Waves are identified to produce rotation in plasma centrifuges, which separate isotopes based on their mass difference. Finally, a new high throughput mass filter which is well suited to separating nuclear waste is presented. The new filter, the magnetic centrifugal mass filter (MCMF), has well confined output streams and less potential for nuclear proliferation than competing technologies. To assess the usefulness of the MCMF, a metric for comparing mass filters is developed. With this metric, the MCMF is compared with other mass filters such as the Ohkawa filter and the conventional plasma centrifuge.

  19. Pade-Froissart exact signal-noise separation in nuclear magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Nuclear magnetic resonance spectroscopy is one of the key methods for studying the structure of matter on different levels (sub-nuclear, nuclear, atomic, molecular, cellular, etc). Its overall success critically depends upon reliable mathematical analysis and interpretation of the studied data. This is especially aided by parametric signal processing with the ensuing data quantification, which can yield the abundance or concentrations of the constituents in the examined matter. The sought reliability of signal processing rests upon the possibility of an accurate solution of the quantification problem alongside the unambiguous separation of true from false information in the spectrally analysed data. We presently demonstrate that the fast Pade transform (FPT), as the unique ratio of two polynomials for a given Maclaurin series, can yield exact signal-noise separation for a synthesized free induction decay curve built from 25 molecules. This is achieved by using the concept of Froissart doublets or pole-zero cancellations. Unphysical/spurious (noise or noise-like) resonances have coincident or near-coincident poles and zeros. They possess either zero- or near-zero-valued amplitudes. Such spectral structures never converge due to their instability against even the smallest perturbations. By contrast, upon convergence of the FPT, physical/genuine resonances are identified by their persistent stability against external perturbations, such as signal truncation or addition of random noise, etc. In practice, the computation is carried out by gradually and systematically increasing the common degree of the Pade numerator and denominator polynomials in the diagonal FPT. As this degree changes, the reconstructed parameters and spectra fluctuate until stabilization occurs. The polynomial degree at which this full stabilization is achieved represents the sought exact number of resonances. An illustrative set of results is reported in this work to show the exact separation of genuine from spurious information by reliance upon Froissart doublets and stabilization of reconstructions. The FPT for optimal quantification of the physical constituents of the studied matter and the denoising Froissart filter for unequivocal signal-noise separation is expected to significantly aid nuclear magnetic resonance spectroscopy in achieving the most reliable data analysis and interpretation.

  20. Research on high gradient magnetic separation of pneumatic conveyed powder products: Investigation from the viewpoint of interparticle interactions

    International Nuclear Information System (INIS)

    Highlights: ? We separated SUS particle from the mixture of alumina/silica and SUS particle. ? The high separation efficiencies were obtained both in two samples. ? The separation efficiency of the sample using alumina did not reach to 100%. ? The adhesion forces between particles were measured when changing the humidity. ? Based on these data, the conditions of the separation experiment were examined. -- Abstract: The separation and removal of the metallic debris originating from pipe of manufacturing line are required in the manufacturing process of the fine particle products. In this study, we develop a high gradient magnetic separation system (HGMS) under a dry process by using a superconducting magnet to remove ferromagnetic particles such as the material stainless steel (SUS). To avoid the obstruction of the separation part by aggregation of the processed material, we develop a magnetic separation system using a pneumatic conveying as a new transportation method of the particles. The magnetic separations were experimented under the same conditions on different days, but the results were different. The reason is considered to be the difference in adhesion force between the particles due to a change of humidity, we have measured the adhesion forces between the ferromagnetic particles and the paramagnetic medium particles using AFM (Atomic Force Microscope) while changing the humidity. As a result, the adhesion force between the particles increased with the increasing of humidity. Furthermore, we saw that the effect of relative humidity was larger in the adhesion force of alumina with larger cohesive property. Based on these results, an appropriate condition of the separation experiment was clarified. And a dehumidification mechanism was introduced

  1. Research on high gradient magnetic separation of pneumatic conveyed powder products: Investigation from the viewpoint of interparticle interactions

    Energy Technology Data Exchange (ETDEWEB)

    Senkawa, Kohei, E-mail: senkawa@qb.see.eng.osaka-u.ac.jp [Graduate School of Engineering, Osaka University, A1 Bldg., 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Nakai, Yuki; Mishima, Fumihito [Graduate School of Engineering, Osaka University, A1 Bldg., 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Akiyama, Yoko, E-mail: yoko-ak@qb.see.eng.osaka-u.ac.jp [Graduate School of Engineering, Osaka University, A1 Bldg., 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Nishijima, Shigehiro [Graduate School of Engineering, Osaka University, A1 Bldg., 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2013-01-15

    Highlights: ? We separated SUS particle from the mixture of alumina/silica and SUS particle. ? The high separation efficiencies were obtained both in two samples. ? The separation efficiency of the sample using alumina did not reach to 100%. ? The adhesion forces between particles were measured when changing the humidity. ? Based on these data, the conditions of the separation experiment were examined. -- Abstract: The separation and removal of the metallic debris originating from pipe of manufacturing line are required in the manufacturing process of the fine particle products. In this study, we develop a high gradient magnetic separation system (HGMS) under a dry process by using a superconducting magnet to remove ferromagnetic particles such as the material stainless steel (SUS). To avoid the obstruction of the separation part by aggregation of the processed material, we develop a magnetic separation system using a pneumatic conveying as a new transportation method of the particles. The magnetic separations were experimented under the same conditions on different days, but the results were different. The reason is considered to be the difference in adhesion force between the particles due to a change of humidity, we have measured the adhesion forces between the ferromagnetic particles and the paramagnetic medium particles using AFM (Atomic Force Microscope) while changing the humidity. As a result, the adhesion force between the particles increased with the increasing of humidity. Furthermore, we saw that the effect of relative humidity was larger in the adhesion force of alumina with larger cohesive property. Based on these results, an appropriate condition of the separation experiment was clarified. And a dehumidification mechanism was introduced.

  2. Bio-inspired durable, superhydrophobic magnetic particles for oil/water separation.

    Science.gov (United States)

    Zhang, Liang; Li, Lili; Dang, Zhi-Min

    2016-02-01

    In the present study, superhydrophobic and superoleophilic microparticles with magnetic property were fabricated by combining the oxidation and self-polymerization of dopamine and formation of Fe3O4 nanoparticles on the surface of the polydopamine (PDA) particles, followed by modification with low surface energy material. The modified PDA/Fe3O4 particles showed high water repellency with contact angle (CA) measured at 153.71.6 and high oil affinity. The superhydrophobic microparticles preserved high water CA after aging test, showing excellent durability. The microparticles were employed to effectively remove oil from water in different routes. Superhydrophobic sponge was prepared by modifying with the achieved microparticles. The sponge exhibited high absorption capability of oil, with weight gains ranging from 1348% to 7268%. The results suggest this work might provide a promising candidate for oily pollutants/water separation and transportation. PMID:26550784

  3. Superparamagnetic magnesium ferrite nanoadsorbent for effective arsenic (III, V) removal and easy magnetic separation.

    Science.gov (United States)

    Tang, Wenshu; Su, Yu; Li, Qi; Gao, Shian; Shang, Jian Ku

    2013-07-01

    By doping a proper amount of Mg(2+) (~10%) into ?-Fe2O3 during a solvent thermal process, ultrafine magnesium ferrite (Mg0.27Fe2.50O4) nanocrystallites were successfully synthesized with the assistance of in situ self-formed NaCl "cage" to confine their crystal growth. Their ultrafine size (average size of ~3.7 nm) and relatively low Mg-content conferred on them a superparamagnetic behavior with a high saturation magnetization (32.9 emu/g). The ultrafine Mg0.27Fe2.50O4 nanoadsorbent had a high specific surface area of ~438.2 m(2)/g, and demonstrated a superior arsenic removal performance on both As(III) and As(V) at near neutral pH condition. Its adsorption capacities on As(III) and As(V) were found to be no less than 127.4 mg/g and 83.2 mg/g, respectively. Its arsenic adsorption mechanism was found to follow the inner-sphere complex mechanism, and abundant hydroxyl groups on its surface played the major role in its superior arsenic adsorption performance. It could be easily separated from treated water bodies with magnetic separation, and could be easily regenerated and reused while maintaining a high arsenic removal efficiency. This novel superparamagnetic magnesium ferrite nanoadsorbent may offer a simple single step adsorption treatment option to remove arsenic contamination from water without the pre-/post-treatment requirement for current industrial practice. PMID:23726698

  4. Photocatalytic degradation of methylene blue on magnetically separable MgFe2O4 under visible light irradiation

    International Nuclear Information System (INIS)

    A magnetically separable single-phase MgFe2O4 photocatalyst with a spinel crystal structure was synthesized by using the solid-state reaction method. The formation of spinel structure is confirmed by X-ray diffraction and Fourier transform infrared spectroscopy. The magnetic measurements showed that the photocatalyst material can be separated from water when an external magnetic field is added and redispersed into water solution after the external magnetic field is eliminated. It is one of the promising photocatalysts for waste water treatment. The photocatalytic activity of MgFe2O4 was investigated by using the photo-decomposition of methylene blue dye under visible light. The photoelectrochemical property of the MgFe2O4 was studied by measuring their photocurrentpotential behavior in 1 M NaOH electrolyte under AM 1.5100 mW cm?2 illumination. - Graphical abstract: Highly efficient magnetically separable MgFe2O4 photocatalyst for organic based impurities decomposition as well as for the production of H2 gas was synthesized and characterized successfully (a) MgFe2O4 photocatalyst in polluted water, (b) The photocatalyst (MgFe2O4) is being attracted toward magnetic field for separation, (c) Hysteresis loop of MgFe2O4 showing magnetic behavior. Highlights: ? New photocatalyst working in the visible range have been synthesized by facile cheap route. ? MgFe2O4 photocatalyst showed well defined magnetically separable behavior. ? Excellent water splitting characteristics to produce H2 was observed under visible light irradiation

  5. Research on high gradient magnetic separation of pneumatic conveyed powder products: Investigation from the viewpoint of interparticle interactions

    Science.gov (United States)

    Senkawa, Kohei; Nakai, Yuki; Mishima, Fumihito; Akiyama, Yoko; Nishijima, Shigehiro

    2013-01-01

    The separation and removal of the metallic debris originating from pipe of manufacturing line are required in the manufacturing process of the fine particle products. In this study, we develop a high gradient magnetic separation system (HGMS) under a dry process by using a superconducting magnet to remove ferromagnetic particles such as the material stainless steel (SUS). To avoid the obstruction of the separation part by aggregation of the processed material, we develop a magnetic separation system using a pneumatic conveying as a new transportation method of the particles. The magnetic separations were experimented under the same conditions on different days, but the results were different. The reason is considered to be the difference in adhesion force between the particles due to a change of humidity, we have measured the adhesion forces between the ferromagnetic particles and the paramagnetic medium particles using AFM (Atomic Force Microscope) while changing the humidity. As a result, the adhesion force between the particles increased with the increasing of humidity. Furthermore, we saw that the effect of relative humidity was larger in the adhesion force of alumina with larger cohesive property. Based on these results, an appropriate condition of the separation experiment was clarified. And a dehumidification mechanism was introduced.

  6. Facile synthesis of magnetically separable reduced graphene oxide/magnetite/silver nanocomposites with enhanced catalytic activity.

    Science.gov (United States)

    Ji, Zhenyuan; Shen, Xiaoping; Yue, Xiaoyang; Zhou, Hu; Yang, Juan; Wang, Yuqin; Ma, Lianbo; Chen, Kangmin

    2015-12-01

    In this study, the combination of magnetite (Fe3O4) with reduced graphene oxide (RGO) generates a new hybrid substrate for the dispersion of noble metal nanoparticles. Well-dispersed silver (Ag) nanoparticles loaded on the surface of Fe3O4 modified RGO are achieved by an efficient two-step approach. Through reducing Ag(+) ions, highly dispersed Ag nanoparticles are in-situ formed on the RGO/Fe3O4 substrate. It is found that the existence of Fe3O4 nanocrystals can significantly improve the dispersity and decrease the particle size of the in-situ formed Ag nanoparticles. Magnetic study reveals that the as-prepared RGO/Fe3O4/Ag ternary nanocomposites display room-temperature superparamagnetic behavior. The catalytic properties of the RGO/Fe3O4/Ag ternary nanocomposites were evaluated with the reduction of 4-nitrophenol into 4-aminophenol as a model reaction. The as-synthesized RGO/Fe3O4/Ag ternary catalysts exhibit excellent catalytic stability and much higher catalytic activity than the corresponding RGO/Ag catalyst. Moreover, the RGO/Fe3O4/Ag catalysts can be easily magnetically separated for reuse. This study further demonstrates that nanoparticles modified graphene can act as an effective hybrid substrate for the synthesis of multi-component and multifunctional graphene-based composites. PMID:26263498

  7. Magnetic orderings and phase separations in a simple model of insulating systems

    Science.gov (United States)

    Kapcia, Konrad Jerzy; Murawski, Szymon; K?obus, Waldemar; Robaszkiewicz, Stanis?aw

    2015-11-01

    A simple effective model for a description of magnetically ordered narrow-band insulators is studied. The Hamiltonian considered consists of the effective on-site interaction (U) and intersite magnetic exchange interactions (Jz, Jxy) between nearest-neighbours. The phase diagrams and properties of this model for arbitrary chemical potential ? and arbitrary electron density n have been determined within several approaches: (i) the variational method (which treats the on-site interaction term exactly and the intersite interactions within the mean-field approximation) for any Jz ,Jxy ? 0 (exact in the limit of infinite dimensions), (ii) the Monte Carlo simulations on a square lattice with periodic boundary conditions for Jxy = 0, and (iii) other approximate methods (inter alia: random phase approximation and spin-wave approximation) as well as (iv) rigorous treatment to obtain results concerning the ground state phase diagrams (the two last also for Jz ,Jxy ? 0). The investigations of the general case show that, depending on the values of interaction parameters and electron concentration n, the system can exhibit not only homogeneous phases: (anti-)ferromagnetic (F?, ? = z , xy) and nonordered (NO), but also phase separated states (PS?: F?/NO). For a fixed n one finds the following phase transitions (both continuous and discontinuous ones) and their sequences, which can occur with increasing temperature: F? ? NO, PS? ? NO, PS? ?F? ? NO, PS? ?F? ?PS? ? NO. The system analysed exhibits also tricritical behaviour.

  8. Optimized high gradient magnetic separation for isolation of Plasmodium-infected red blood cells

    Directory of Open Access Journals (Sweden)

    Chimma Pattamawan

    2010-02-01

    Full Text Available Abstract Background Highly purified infected red blood cells (irbc, or highly synchronized parasite cultures, are regularly required in malaria research. Conventional isolation and synchronization rely on density and osmotic fragility of irbc, respectively. High gradient magnetic separation (HGMS offers an alternative based on intrinsic magnetic properties of irbc, avoiding exposure to chemicals and osmotic stress. Successful HGMS concentration in malaria research was previously reported using polymer coated columns, while HGMS depletion has not been described yet. This study presents a new approach to both HGMS concentration and depletion in malaria research, rendering polymer coating unnecessary. Methods A dipole magnet generating a strong homogenous field was custom assembled. Polypropylene syringes were fitted with one-way stopcocks and filled with stainless steel wool. Rbc from Plasmodium falciparum cultures were resuspended in density and viscosity optimized HGMS buffers and HGMS processed. Purification and depletion results were analysed by flow cytometer and light microscopy. Viability was evaluated by calculating the infection rate after re-culturing of isolates. Results In HGMS concentration, purity of irbc isolates from asynchronous cultures consistently ranged from 94.8% to 98.4% (mean 95.7%. With further optimization, over 90% of isolated irbc contained segmented schizonts. Processing time was less than 45 min. Reinfection rates ranged from 21.0% to 56.4%. In HGMS depletion, results were comparable to treatment with sorbitol, as demonstrated by essentially identical development of cultures. Conclusion The novel HGMS concentration procedure achieves high purities of segmented stage irbc from standard asynchronous cultures, and is the first HGMS depletion alternative to sorbitol lysis. It represents a simple and highly efficient alternative to conventional irbc concentration and synchronization methods.

  9. Templated synthesis of monodisperse mesoporous maghemite/silica microspheres for magnetic separation of genomic DNA

    Science.gov (United States)

    Chen, Feng; Shi, Ruobing; Xue, Yun; Chen, Lei; Wan, Qian-Hong

    2010-08-01

    A novel method is described for the preparation of superparamagnetic mesoporous maghemite (?-Fe 2O 3)/silica (SiO 2) composite microspheres to allow rapid magnetic separation of DNA from biological samples. With magnetite (Fe 3O 4) and silica nanoparticles as starting materials, such microspheres were synthesized by the following two consecutive steps: (1) formation of monodispersed organic/inorganic hybrid microspheres through urea-formaldedyde (UF) polymerization and (2) removal of the organic template and phase transformation of Fe 3O 4 to ?-Fe 2O 3 by calcination at elevated temperatures. The as-synthesized particles obtained by heating at temperature 300 C feature spherical shape and uniform particle size ( dparticle=1.72 ?m), high saturation magnetization ( Ms=17.22 emu/g), superparamagnetism ( Mr/ Ms=0.023), high surface area ( SBET=240 m 2/g), and mesoporosity ( dpore=6.62 nm). The composite microsphere consists of interlocked amorphous SiO 2 nanoparticles, in which cubic ?-Fe 2O 3 nanocrystals are homogeneously dispersed and thermally stable against ?- to ?-phase transformation at temperatures up to 600 C. With the exposed iron oxide nanoparticles coated with a thin layer of silica shell, the magnetic microspheres were used as a solid-phase adsorbent for rapid extraction of genomic DNA from plant samples. The results show that the DNA templates isolated from pea and green pepper displayed single bands with molecular weights greater than 8 kb and A260/ A280 values of 1.60-1.72. The PCR amplification of a fragment encoding the endogenous chloroplast ndhB gene confirmed that the DNA templates obtained were inhibitor-free and amenable to sensitive amplification-based DNA technologies.

  10. Studies of charge separation characteristics for higher density plasma in a direct energy converter using slanted cusp magnetic field

    International Nuclear Information System (INIS)

    In an advanced fusion, fusion-produced charged particles must be separated from each other for converting their kinetic energy to electricity. The CUSPDEC performs this function of separation and direct energy conversion of thermal components. This paper summarizes experimental works by using a small scale experimental device and these results as charge separation characteristics by slanted cusp magnetic field. When the incident plasma is low-density, the dependences of the separation efficiency on magnetic field strength, energy of electrons, and gradient of the field line are explained by the theory based on a single particle motion. In high density plasma, however, this theory cannot always be applied due to a self-induced field. In the experiment, as plasma density became higher, separation capability of the charged particles became lower although the efficiency of separation was improved with some extent by using slanted cusp magnetic field. The modification of the theory applicable for high density plasma and the effective factor corresponding to separation efficiency was required in the following research. (author)

  11. Photocatalytic degradation of methylene blue on magnetically separable MgFe2O4 under visible light irradiation

    KAUST Repository

    Shahid, Muhammad

    2013-05-01

    A magnetically separable single-phase MgFe2O4 photocatalyst with a spinel crystal structure was synthesized by using the solid-state reaction method. The formation of spinel structure is confirmed by X-ray diffraction and Fourier transform infrared spectroscopy. The magnetic measurements showed that the photocatalyst material can be separated from water when an external magnetic field is added and redispersed into water solution after the external magnetic field is eliminated. It is one of the promising photocatalysts for waste water treatment. The photocatalytic activity of MgFe2O4 was investigated by using the photo-decomposition of methylene blue dye under visible light. The photoelectrochemical property of the MgFe2O4 was studied by measuring their photocurrent-potential behavior in 1 M NaOH electrolyte under AM 1.5100 mW cm-2 illumination. © 2013 Elsevier B.V. All rights reserved.

  12. Spatiotemporally separating electron and phonon thermal transport in L10 FePt films for heat assisted magnetic recording

    International Nuclear Information System (INIS)

    We report the spatio-temporal separation of electron and phonon thermal transports in nanostructured magnetic L10 FePt films at the nanometer length scale and the time domain of tens of picosecond, when heated with a pulsed laser. We demonstrate that lattice dynamics measured using the picosecond time-resolved laser pump/X-ray probe method on the FePt (002) and Ag (002) Bragg reflections from different layers provided the information of nanoscale thermal transport between the layers. We also describe how the electron and phonon thermal transports in nanostructured magnetic thin films were separated.

  13. Fabrication of chiral amino acid ionic liquid modified magnetic multifunctional nanospheres for centrifugal chiral chromatography separation of racemates.

    Science.gov (United States)

    Liu, Yating; Tian, Ailin; Wang, Xiong; Qi, Jing; Wang, Fengkang; Ma, Ying; Ito, Yoichiro; Wei, Yun

    2015-06-26

    As the rapid development of nanotechnology, the magnetic nanospheres modified with special chiral selective ligands show a great potentiality in enantiomeric separation. In this study, magnetic nanospheres modified with task-specific chiral ionic liquid were designed for the separation of chiral amino acids. These modified magnetic nanospheres were effective in a direct chiral separation of five racemic amino acids (D- and L-cysteine, D- and L-arginine, D- and L-leucine, D- and L-glutamine and D- and L-tryptophan). Furthermore, a new online method for complete separation of the enantiomers via the magnetic nanospheres was established with centrifugal chiral chromatography using a spiral tube assembly mounted on a type-J coil planet centrifuge. One kind of chiral compounds, D- and L-tryptophan was resolved well using this method. These results demonstrated that the modified nanospheres display a good chiral recognition ability, and can be used as a potential material for chiral separation of various racemates. PMID:25976126

  14. Analytical description of the coefficient of demagnetization for chains of cores of granulesin the filter matrix of a magnetic separator ????????????? ???????? ???????????? ??????????????? ????????????? ????????? ??????? ?????? ??????-??????? ?????????? ??????????

    Directory of Open Access Journals (Sweden)

    Sandulyak Anna Aleksandrovna

    2013-09-01

    Full Text Available Particle capturing efficiency inside the filter matrix of a magnetic separator used in the treatment of ceramic suspensions, minerals, condensates, other liquids and gas depends immediately on the intensity of its magnetization capacity. Chains of granules of a filter matrix represent effective magnetization channels. Demagnetization intensity influences the magnetization intensity of the whole filter matrix and its separate chains that are also considered as magnetization channels. The pattern of calculation of demagnetization factor N (coefficient of demagnetization for such channel magnets is of utmost academic interest, and this pattern is provided in this article. The author provides values for demagnetization factor N for quasi solid cores ofchains of granules having with various lengths L and diameters d (metal concentra-tion 0.780.99, if magnetized by the field having the intensity of ? =18175 k?/m. It isproven that the values of N and ? L / d have an exponential relation.Earlier, the author identified that the values of N for the porous media having a cylindrical form depend on the ratio of the length of magnet L to its diameter D . It is proven that the values of N and those of ? L / D also have an exponential relation. Therefore, this reciprocal conformity of relations in respect of the demagnetization factor for samples of the granulated medium (consisting of chains of magnets-channels and for cores of magnets-channels (having different porosity values has confirmed the similarity of the demagnetization factor for magnets having substantial and high concentration of the ferromagnetic material. The analytical description (the formula of the coefficient of demagnetization of channel cores is provided in the article.?????? ?? ???????????? ????????? ? ??????????? ?????????????? ??????????????? ????, ? ??????? ???????????? ???????????-???????? ???????? ??????? ?????????????? ??????, ?????????? ??????? ??????? ??????? ?????? ? ?????????? ????????????????? ??????? N ????? ???????. ????????? ???????? N ??? ????????????? ????????? ??????? ????????? ???? L ? ????????? d , ? ????? ????????? ??? N ? ?????????? ? ???? ???????? ?????????????? ???????? ?????????? ? L / d , ??? ????????? ??????????? ? ??????????? ?????????? ??? ??????? ??????????????? ????? (????????? ?? ????? ???????.

  15. Magnetic isotope and magnetic field effects on chemical reactions. Sunlight and soap for the efficient separation of 13C and 12C isotopes

    International Nuclear Information System (INIS)

    Photolysis of dibenzyl ketone (DBK) solution at room temperature yields 1,2-diphenylethane and carbon monoxide quantitatively. Results of the study of this reaction, using light and ordinary mercury lamps as excitation sources, show that (1) a measurable, but small, 12C/13C isotope separation occurs in homogeneous (benzene) solution; (2) the efficiency of the separation is greatly enhanced in soap solution relative to homogeneous solution; (3) the carbonyl carbon of DBK is specifically and exponentially enriched as photolysis proceeds; (4) an external magnetic field significantly influences the efficiency of the isotopic separation. Mass spectroscopic and NMR analyses of the recovered DBK confirm these conclusions. 2 figures

  16. Magnetically separable nanocomposites with photocatalytic activity under visible light for the selective transformation of biomass-derived platform molecules

    Science.gov (United States)

    Novel magnetically separable TiO2-guanidine-(Ni,Co)Fe2O4 nanomaterials were prepared and characterised by a series of techniques including XRD, SEM, TEM, N2 physisorption as well as XPS and subsequently tested for their photocatalytic activities in the selective transformation of...

  17. Metal organic framework derived magnetically separable 3-dimensional hierarchical Ni@C nanocomposites: Synthesis and adsorption properties

    Science.gov (United States)

    Song, Yixuan; Qiang, Tingting; Ye, Ming; Ma, Qiuyang; Fang, Zhen

    2015-12-01

    Design an effective absorbent that has high surface area, and perfect recyclable is imperative for pollution elimination. Herein, we report a facile two-step strategy to fabricate magnetically separable 3-dimensional (3D) hierarchical carbon-coated nickel (Ni@C) nanocomposites by calcinating nickel based metal organic framework (Ni3(OH)2(C8H4O4)2(H2O)4). SEM and TEM images illuminate that the nanocomposites were constructed by 8 nm nickel nanoparticle encapsulated in 3D flake like carbon. The specific surface area of the obtained nanocomposites is up to 120.38 m2 g-1. Room temperature magnetic measurement indicates the nanocomposites show soft magnetism property, which endows the nanocomposites with an ideal fast magnetic separable property. The maximum adsorption capacity of the nanocomposites for rhodamine B is 84.5 mg g-1. Furthermore, the nanocomposites also exhibit a high adsorption capacity for heavy metal ions. The adsorbent can be very easily separated from the solution by using a common magnet without exterior energy. The as-prepared Ni@C nanocomposites can apply in waste water treatment on a large-scale as a new adsorbent with high efficiency and excellent recyclability.

  18. Novel magnetically separable AgCl/iron oxide composites with enhanced photocatalytic activity driven by visible light

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ying; Zhang, Yanrong, E-mail: yanrong_zhang@hust.edu.cn; Tan, Jue

    2013-10-15

    Highlights: The AgCl/iron oxide composites were prepared by a chemical precipitation method. The composites exhibited improved performances in the photodegradation of pollutants. The visible light photocatalysts could be recycled easily by a magnet. -- Abstract: In this work, AgCl/iron oxide composites were synthesized by a simple chemical precipitation method and calcining process. The composition of the material and magnetic and optical properties of the composites were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating specimen magnetometer (VSM) techniques, which confirms the high crystalline and magnetic behavior of the composites. UV-vis diffuse reflectance spectral (DRS) studies showed that the AgCl/iron oxide composites were of much higher absorption in longer wavelength region compared to bare iron oxide. The AgCl/iron oxide composites showed better performance in the photodegradation of organic dyes Rhodamin B (RhB) under the fluorescent lamp irradiation, which is remarkably superior to the N-TiO{sub 2}. The degradation of microcystin-LR (MC-LR) and phenol was also found to be good owing to its effective electron-hole separation at AgCl/iron oxide interface. The separation of AgCl/iron oxide composites from the treated water was achieved by an external magnetic field as ?-Fe{sub 2}O{sub 3} exhibits enough magnetic power to facilitate the separation.

  19. Separation of species of a binary fluid mixture confined in a channel in presence of a strong transverse magnetic field

    Directory of Open Access Journals (Sweden)

    Sharma Bishwaram

    2012-01-01

    Full Text Available Effects of a transverse magnetic field on separation of a binary mixture of incompressible viscous thermally and electrically conducting fluids confined between two stationary parallel plates are examined. Both the plates are maintained at constant temperatures. It is assumed that one of the components, which is rarer and lighter, is present in the mixture in a very small quantity. The equations governing the motion, temperature and concentration in Cartesian coordinate are solved analytically. The solution obtained for concentration distribution is plotted against the width of the channel for various values of non-dimensional parameters. It is found that the effect of transverse magnetic field is to separate the species of rarer and lighter component by contributing its effect directly to the temperature gradient and the pressure gradient. The effects of increase in the values of Hartmann number, magnetic Reynolds number, barodiffusion number, thermal diffusion number, electric field parameter and the product of Prandtl number and Eckert number are to collect the rarer and lighter component near the upper plate and throw away the heavier component towards the lower plate. The problem discussed here derives its application in the basic fluid dynamics separation processes to separate the rare component of the different isotopes of heavier molecules where electromagnetic method of separation does not work.

  20. A highly-efficient imprinted magnetic nanoparticle for selective separation and detection of 17?-estradiol in milk.

    Science.gov (United States)

    Gao, Ruixia; Cui, Xihui; Hao, Yi; Zhang, Lili; Liu, Dechun; Tang, Yuhai

    2016-03-01

    In this work, we prepared molecularly imprinted polymers (MIPs) combining surface molecular imprinting technique and magnetic separation for separation and determination of 17?-estradiol (E2) from milk. During the synthesis process, the acryloyl chloride was specially used to graft double bonds on Fe3O4 nanoparticles and served as co-functional monomer cooperating with acrylamide. The morphology, structure property, and the best polymerization and adsorption conditions of the prepared magnetic nanoparticles were investigated in detail. The obtained nanomaterials displayed high adsorption capacity of 12.62mg/g, fast equilibrium time of 10min, and satisfactory selectivity for target molecule. What's more, the MIPs was successfully applied as sorbents to specifically separate and enrich E2 from milk with a relatively high recovery (88.9-92.1%), demonstrating the potential application of the MIPs as solid phase extractant for rapid, highly-efficient, and cost-effective sample analysis. PMID:26471651

  1. Boundary-value problem for a counterrotating electrical discharge in an axial magnetic field. [plasma centrifuge for isotope separation

    Science.gov (United States)

    Hong, S. H.; Wilhelm, H. E.

    1978-01-01

    An electrical discharge between two ring electrodes embedded in the mantle of a cylindrical chamber is considered, in which the plasma in the anode and cathode regions rotates in opposite directions under the influence of an external axial magnetic field. The associated boundary-value problem for the coupled partial differential equations describing the azimuthal velocity and radial current-density fields is solved in closed form. The velocity, current density, induced magnetic induction, and electric fields are presented for typical Hartmann numbers, magnetic Reynolds numbers, and geometry parameters. The discharge is shown to produce anodic and cathodic plasma sections rotating at speeds of the order 1,000,000 cm/sec for conventional magnetic field intensities. Possible application of the magnetoactive discharge as a plasma centrifuge for isotope separation is discussed.

  2. Synthesis, characterization and photocatalytic activity of magnetically separable hexagonal Ni/ZnO nanostructure

    Science.gov (United States)

    Senapati, Samarpita; Srivastava, Suneel K.; Singh, Shiv B.

    2012-09-01

    The hexagonal zinc oxide coated nickel (Ni/ZnO) nanostructure photocatalyst has successfully been prepared by the reduction of nickel chloride hexahydrate using hydrazine hydrate through the solvothermal process at 140 C followed by surface modification of the product by the reflux method at 110 C for 1 h. The X-ray diffraction (XRD) pattern showed that the `as prepared' sample consists of face centered cubic Ni and hexagonal wurtzite ZnO without any traces of impurity. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) images confirmed the formation of nickel nanoparticles under solvothermal conditions. These nickel nanoparticles, when subjected to reflux, formed the hexagonal zinc oxide coated nickel nanostructure. Fourier transform infrared (FTIR) spectra, photoluminescence (PL) and Raman studies also confirmed the presence of zinc oxide in the hybrid nanostructure. The growth mechanism for the development of the hexagonal zinc oxide coated nickel (Ni/ZnO) nanostructure has also been proposed. The appearance of the hysteresis loop, in the as-prepared Ni/ZnO hybrid nanostructure, demonstrated its ferromagnetic character at room temperature. The hexagonal Ni/ZnO nanostructure also acts as an efficient photocatalyst in the degradation of methylene blue under ultraviolet light irradiation. It is observed that the catalytic efficiency of the hybrid nanocatalyst is better compared to pure zinc oxide. Most importantly, the Ni/ZnO catalyst could also be easily separated, simply by applying an external magnetic field, and reused.The hexagonal zinc oxide coated nickel (Ni/ZnO) nanostructure photocatalyst has successfully been prepared by the reduction of nickel chloride hexahydrate using hydrazine hydrate through the solvothermal process at 140 C followed by surface modification of the product by the reflux method at 110 C for 1 h. The X-ray diffraction (XRD) pattern showed that the `as prepared' sample consists of face centered cubic Ni and hexagonal wurtzite ZnO without any traces of impurity. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) images confirmed the formation of nickel nanoparticles under solvothermal conditions. These nickel nanoparticles, when subjected to reflux, formed the hexagonal zinc oxide coated nickel nanostructure. Fourier transform infrared (FTIR) spectra, photoluminescence (PL) and Raman studies also confirmed the presence of zinc oxide in the hybrid nanostructure. The growth mechanism for the development of the hexagonal zinc oxide coated nickel (Ni/ZnO) nanostructure has also been proposed. The appearance of the hysteresis loop, in the as-prepared Ni/ZnO hybrid nanostructure, demonstrated its ferromagnetic character at room temperature. The hexagonal Ni/ZnO nanostructure also acts as an efficient photocatalyst in the degradation of methylene blue under ultraviolet light irradiation. It is observed that the catalytic efficiency of the hybrid nanocatalyst is better compared to pure zinc oxide. Most importantly, the Ni/ZnO catalyst could also be easily separated, simply by applying an external magnetic field, and reused. Electronic supplementary information (ESI) available: Fig. S1 Ni/ZnO hybrid nanostructure prepared using (a) 0.195 and (b) 0.25 M [Zn2+] at 90 C Fig. S2 FTIR spectra of nickel nanoparticles prepared at 140 C (a), and Ni/ZnO hybrid nanostructure prepared using (b) 0.063, (c) 0.125, (d) 0.195 and (e) 0.25 M [Zn2+]; Fig. S3 Raman spectra of Ni/ZnO nanostructure prepared using (a) 0.063, (b) 0.125, (c) 0.195 and (d) 0.25 M [Zn2+]; Fig. S4 Room temperature PL spectra of (a) ZnO and (b) Ni/ZnO nanostructure prepared using 0.25 M [Zn2+]. See DOI: 10.1039/c2nr31831h

  3. Folic acid conjugated magnetic iron oxide nanoparticles for nondestructive separation and detection of ovarian cancer cells from whole blood.

    Science.gov (United States)

    Liu, Wenting; Nie, Liju; Li, Fulai; Aguilar, Zoraida P; Xu, Hong; Xiong, Yonghua; Fu, Fen; Xu, Hengyi

    2015-12-15

    Because of the lack of early screening strategies, ovarian cancer is the most deadly cause of gynecologic malignancies. This paper describes an effective method for the separation and detection of ovarian cancer cells from female whole blood, using folic acid (FA) conjugated magnetic iron oxide nanoparticles (IO-FA nanoparticles). The IO nanoparticles were synthesized by thermal decomposition and then covalently conjugated with FA. The IO-FA nanoparticles were stably attached to the surface of ovarian cancer cells by coupling to the over-expressed folate receptor (FR), thereby making the cells magnetic. These "magnetic cells" were separated from the complex blood matrix without destruction under a magnetic field. The separation efficiency was as high as 61.3% when the abundance of spiked ovarian cancer SKOV3 cells was as low as 5 × 10(-5)%. We also successfully detected five (5) out of ten (10) metastatic ovarian cancer patients' whole blood. This study suggested the feasibility of early detecting of metastatic ovarian cancer cells, which may potentially improve the ovarian cancers patients' overall survival rate for clinical applications. PMID:26478922

  4. Magnetic phase separation in double layer ruthenates Ca3(Ru1-xTix)2O7.

    Science.gov (United States)

    Peng, Jin; Liu, J Y; Hu, J; Mao, Z Q; Zhang, F M; Wu, X S

    2016-01-01

    A phase transition from metallic AFM-b antiferromagnetic state to Mott insulating G-type antiferromagnetic (G-AFM) state was found in Ca3(Ru1-xTix)2O7 at about x?=?0.03 in our previous work. In the present, we focused on the study of the magnetic transition near the critical composition through detailed magnetization measurements. There is no intermediate magnetic phases between the AFM-b and G-AFM states, which is in contrasted to manganites where a similar magnetic phase transition takes place through the presence of several intermediate magnetic phases. The AFM-b-to-G-AFM transition in Ca3(Ru1-xTix)2O7 happens through a phase separation process in the 2-5% Ti range, whereas similar magnetic transitions in manganites are tuned by 50-70% chemical substitutions. We discussed the possible origin of such an unusual magnetic transition and compared with that in manganites. PMID:26771083

  5. Separation of radioimmunoassay in magnetic phase with particles prepared at the IPEN and its comparison with conventional methodologies

    International Nuclear Information System (INIS)

    In the present work two main objectives were chosen. The first was the preparation for the execution of the magnetic phase separation technique, useful for the radioimmunoassay as well as for the most modern and most efficient immunoradiometric assay. The second objective, of a theoretical-practical kind and directly linked to the first, was the realization of a study about the precision of the technique with synthesized products compared with imported products and with two liquid phase separation techniques: the second antibody and polyethyleneglycol (PEG). This analysis was performed with the help of precision profiles built according to R.P.Ekins' recommendations. (author)

  6. Separation of Water and Fat Signal in Magnetic Resonance Imaging : Advances in Methods Based on Chemical Shift

    OpenAIRE

    Berglund, Johan

    2011-01-01

    Magnetic resonance imaging (MRI) is one of the most important diagnostic tools of modern healthcare. The signal in medical MRI predominantly originates from water and fat molecules. Separation of the two components into water-only and fat-only images can improve diagnosis, and is the premier non-invasive method for measuring the amount and distribution of fatty tissue. Fat-water imaging (FWI) enables fast fat/water separation by model-based estimation from chemical shift encoded data, such as...

  7. Beam-energy dependence of charge separation along the magnetic field in Au+Au collisions at RHIC

    CERN Document Server

    Adamczyk, L; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Anson, C D; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Banerjee, A; Beavis, D R; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Brandin, A V; Brovko, S G; Bltmann, S; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Snchez, M Caldern de la Barca; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chwastowski, J; Codrington, M J M; Contin, G; Cramer, J G; Crawford, H J; Cui, X; Das, S; Leyva, A Davila; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; de Souza, R Derradi; Dhamija, S; di Ruzza, B; Didenko, L; Dilks, C; Ding, F; Djawotho, P; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Engle, K S; Eppley, G; Eun, L; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Fedorisin, J; Filip, P; Finch, E; Fisyak, Y; Flores, C E; Gagliardi, C A; Gangadharan, D R; Garand, D; Geurts, F; Gibson, A; Girard, M; Gliske, S; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, A; Gupta, S; Guryn, W; Haag, B; Hamed, A; Han, L-X; Haque, R; Harris, J W; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, B; Huang, H Z; Huang, X; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kesich, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Kosarzewski, L K; Kotchenda, L; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; LeVine, M J; Li, C; Li, W; Li, X; Li, Y; Li, Z M; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, G L; Ma, Y G; Don, D M M D Madagodagettige; Mahapatra, D P; Majka, R; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Minaev, N G; Mioduszewski, S; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nelson, J M; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Olvitt, D L; Pachr, M; Page, B S; Pal, S K; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlak, T; Pawlik, B; Pei, H; Perkins, C; Peryt, W; Pile, P; Planinic, M; Pluta, J; Poljak, N; Poniatowska, K; Porter, J; Poskanzer, A M; Pruthi, N K; Przybycien, M; Pujahari, P R; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Riley, C K; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ross, J F; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Singaraju, R N; Skoby, M J; Smirnov, D; Smirnov, N; Solanki, D; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Sun, X; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szelezniak, M A; Takahashi, J; Tang, A H; Tang, Z; Tarnowsky, T; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Turnau, J; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Vanfossen,, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Vertesi, R; Videbk, F; Viyogi, Y P; Vokal, S; Vossen, A; Wada, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, X L; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, H; Xu, J; Xu, N; Xu, Q H; Xu, Y; Xu, Z; Yan, W; Yang, C; Yang, Y; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Yu, N; Zawisza, Y; Zbroszczyk, H; Zha, W; Zhang, J B; Zhang, J L; Zhang, S; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y; Zyzak, M

    2014-01-01

    Local parity-odd domains are theorized to form inside a Quark-Gluon-Plasma (QGP) which has been produced in high-energy heavy-ion collisions. The local parity-odd domains manifest themselves as charge separation along the magnetic field axis via the chiral magnetic effect (CME). The experimental observation of charge separation has previously been reported for heavy-ion collisions at the top RHIC energies. In this paper, we present the results of the beam-energy dependence of the charge correlations in Au+Au collisions at midrapidity for center-of-mass energies of 7.7, 11.5, 19.6, 27, 39 and 62.4 GeV from the STAR experiment. After background subtraction, the signal gradually reduces with decreased beam energy, and tends to vanish by 7.7 GeV. The implications of these results for the CME will be discussed.

  8. Beam-energy dependence of charge separation along the magnetic field in Au+Au collisions at RHIC.

    Science.gov (United States)

    Adamczyk, L; Adkins, J K; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Anson, C D; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Banerjee, A; Beavis, D R; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Brandin, A V; Brovko, S G; Bltmann, S; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Caldern de la Barca Snchez, M; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chwastowski, J; Codrington, M J M; Contin, G; Cramer, J G; Crawford, H J; Cui, X; Das, S; Davila Leyva, A; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; Derradi de Souza, R; Dhamija, S; di Ruzza, B; Didenko, L; Dilks, C; Ding, F; Djawotho, P; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Engle, K S; Eppley, G; Eun, L; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Fedorisin, J; Filip, P; Finch, E; Fisyak, Y; Flores, C E; Gagliardi, C A; Gangadharan, D R; Garand, D; Geurts, F; Gibson, A; Girard, M; Gliske, S; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, A; Gupta, S; Guryn, W; Haag, B; Hamed, A; Han, L-X; Haque, R; Harris, J W; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, B; Huang, H Z; Huang, X; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kesich, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Kotchenda, L; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; LeVine, M J; Li, C; Li, W; Li, X; Li, X; Li, Y; Li, Z M; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, G L; Ma, Y G; Madagodagettige Don, D M M D; Mahapatra, D P; Majka, R; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Minaev, N G; Mioduszewski, S; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nelson, J M; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Olvitt, D L; Pachr, M; Page, B S; Pal, S K; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlak, T; Pawlik, B; Pei, H; Perkins, C; Peryt, W; Pile, P; Planinic, M; Pluta, J; Poljak, N; Porter, J; Poskanzer, A M; Pruthi, N K; Przybycien, M; Pujahari, P R; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Riley, C K; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ross, J F; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Singaraju, R N; Skoby, M J; Smirnov, D; Smirnov, N; Solanki, D; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Sun, X; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szelezniak, M A; Takahashi, J; Tang, A H; Tang, Z; Tarnowsky, T; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Turnau, J; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Vertesi, R; Videbk, F; Viyogi, Y P; Vokal, S; Voloshin, S A; Vossen, A; Wada, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, X L; Wang, Y; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, H; Xu, J; Xu, N; Xu, Q H; Xu, Y; Xu, Z; Yan, W; Yang, C; Yang, Y; Yang, Y; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Yu, N; Zawisza, Y; Zbroszczyk, H; Zha, W; Zhang, J B; Zhang, J L; Zhang, S; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y; Zyzak, M

    2014-08-01

    Local parity-odd domains are theorized to form inside a quark-gluon plasma which has been produced in high-energy heavy-ion collisions. The local parity-odd domains manifest themselves as charge separation along the magnetic field axis via the chiral magnetic effect. The experimental observation of charge separation has previously been reported for heavy-ion collisions at the top RHIC energies. In this Letter, we present the results of the beam-energy dependence of the charge correlations in Au+Au collisions at midrapidity for center-of-mass energies of 7.7, 11.5, 19.6, 27, 39, and 62.4GeV from the STAR experiment. After background subtraction, the signal gradually reduces with decreased beam energy and tends to vanish by 7.7GeV. This implies the dominance of hadronic interactions over partonic ones at lower collision energies. PMID:25126911

  9. Graphene supported silver@silver chloride & ferroferric oxide hybrid, a magnetically separable photocatalyst with high performance under visible light irradiation

    Science.gov (United States)

    Zhong, Suting; Jiang, Wei; Han, Mei; Liu, Gongzong; Zhang, Na; Lu, Yue

    2015-08-01

    A stable magnetic separable plasmonic photocatalyst was successfully fabricated by grafting silver@silver chloride (Ag@AgCl) and ferroferric oxide (Fe3O4) nanoparticles on graphene sheets. The composite exhibited high activity degrading methylene blue (MB) and rhodamine B (RB) under visible light irradiation: decomposition 97.4% of MB in 100 min and 97.9% of RB in 120 min. The enhanced photocatalytic activities can be attributed to synergistic effect between Ag@AgCl and graphene: the effective charge transfer from Ag@AgCl to graphene thus promotes the separation of electron-hole pairs. Moreover, the excellent magnetic property gives a more convenient way to recycle the photocatalysts.

  10. The Application of High–Gradient Magnetic Separation to Water Treatment by Means of Chemically Precipitated Magnetite

    OpenAIRE

    Hencl, V.; Mucha, P.

    1994-01-01

    Conditions of high–gradient magnetic separation (HGMS) of chemically precipitated magnetite, prepared from a waste material of the titanium white production were studied. The magnetite was used as a sorption material for the treatment of water from the Vltava River. Detailed experimental research resulted in a proposal for a technology of water treatment, schematic description of which is presented. The results of HGMS of chemically precipitated magnetite together with those of water treatmen...

  11. The Vlasov equation with strong magnetic field and oscillating electric field as a model of isotope resonant separation

    CERN Document Server

    Frenod, E; Frenod, Emmanuel; Watbled, Frederique

    2002-01-01

    We study qualitative behavior of the Vlasov equation with strong external magnetic field and oscillating electric field. This model is relevant in order to understand isotop resonant separation. We show that the effective equation is a kinetic equation with a memory term. This memory term involves a pseudo-differential operator whose kernel is characterized by an integral equation involving Bessel functions. In some particular cases, the kernel is explicitly given.

  12. The Vlasov equation with strong magnetic field and oscillating electric field as a model for isotop resonant separation

    Directory of Open Access Journals (Sweden)

    Emmanuel Frenod

    2002-01-01

    Full Text Available We study the qualitative behavior of solutions to the Vlasov equation with strong external magnetic field and oscillating electric field. This model is relevant to the understanding of isotop resonant separation. We show that the effective equation is a kinetic equation with a memory term. This memory term involves a pseudo-differential operator whose kernel is characterized by an integral equation involving Bessel functions. The kernel is explicitly given in some particular cases.

  13. The Vlasov equation with strong magnetic field and oscillating electric field as a model for isotop resonant separation

    OpenAIRE

    Emmanuel Frenod; Frederique Watbled

    2002-01-01

    We study the qualitative behavior of solutions to the Vlasov equation with strong external magnetic field and oscillating electric field. This model is relevant to the understanding of isotop resonant separation. We show that the effective equation is a kinetic equation with a memory term. This memory term involves a pseudo-differential operator whose kernel is characterized by an integral equation involving Bessel functions. The kernel is explicitly given in some particular cases.

  14. Evidence for magnetic phase separation in La0.86Sr0.14Mn1-xCuxO3+? manganites from NMR and magnetic measurements

    International Nuclear Information System (INIS)

    Polycrystalline La0.86Sr0.14Mn1-xCuxO3+? (x = 0, 0.05, 0.10, 0.15, 0.20) manganites were investigated by means of magnetic measurements and zero-field 139La and 55Mn nuclear magnetic resonance (NMR) spectroscopy. Magnetization versus temperature measurements revealed a paramagnetic to ferromagnetic transition in most samples, with lower Curie temperatures and broader transitions for samples with higher Cu contents. The details of the magnetization measurements suggested a phase-separated scenario, with ferromagnetic clusters embedded in an antiferromagnetic matrix, especially for the samples with large Cu contents (x = 0.15 and 0.20). Zero-field 139La NMR measurements confirmed this finding, since the spectral features remained almost unchanged for all Cu-doped samples, whereas the bulk magnetization was drastically reduced with increasing Cu content. 55Mn NMR spectra were again typical of ferromagnetic regions, with a broadening of the resonance line caused by the disorder introduced by the Cu doping. The results indicate a coexistence of different magnetic phases in the manganites studied, with the addition of Cu contributing to the weakening of the double-exchange interaction in most parts of the material

  15. Magnetically separable Ag3PO4/NiFe2O4 composites with enhanced photocatalytic activity.

    Science.gov (United States)

    Patil, Santosh S; Tamboli, Mohaseen S; Deonikar, Virendrakumar G; Umarji, Govind G; Ambekar, Jalindar D; Kulkarni, Milind V; Kolekar, Sanjay S; Kale, Bharat B; Patil, Deepak R

    2015-12-21

    Magnetically separable Ag3PO4/NiFe2O4 (APO/NFO) composites were prepared by an in situ precipitation method. The photocatalytic activity of photocatalysts consisting of different APO/NFO mass ratios was evaluated by degradation of methylene blue (MB) under visible light irradiation. The excellent photocatalytic activity was observed using APO/NFO5 (5% NFO) composites with good cycling stability which is higher than that of pure Ag3PO4 and NiFe2O4. All the APO/NFO composites showed good magnetic behavior, which makes them magnetically separable after reaction and reusable for several experiments. Photoconductivities of pure and composite samples were examined to study the photoresponse characteristics. The current intensity greatly enhanced by loading NFO to APO. Furthermore, the photocatalytic performance of the samples is correlated with the conductivity of the samples. The enhancement in the photocatalytic activity of APO/NFO composites for MB degradation is attributed to the excellent conductivity of APO/NFO composites through the co-catalytic effect of NFO by providing accelerated charge separation through the n-n interface. PMID:26508302

  16. Visible light activated photocatalytic degradation of tetracycline by a magnetically separable composite photocatalyst: Graphene oxide/magnetite/cerium-doped titania.

    Science.gov (United States)

    Cao, Muhan; Wang, Peifang; Ao, Yanhui; Wang, Chao; Hou, Jun; Qian, Jin

    2016-04-01

    In this study, magnetic graphene oxide-loaded Ce-doped titania (MGO-Ce-TiO2) hybridized composite was prepared by a facile method. The as-prepared samples exhibited good adsorption capacity, high visible-light photoactive and magnetic separability as a novel photocatalyst in the degradation of tetracyclines (TC). The intermediate products and photocatalytic route of TC were proposed based on the analysis results of LC-MS. Moreover, the repeatability of the photoactivity with the use of MGO-Ce-TiO2 was investigated in the multi-round experiments with the assistance of an applied magnetic field. Therefore, the prepared composite photocatalysts were considered as a kind of promising photocatalyst in a suspension reaction system, in which they can offer effectively recovery ability. The effect of MGO content on the photocatalytic performance was also studied, and an optimum content was obtained. PMID:26799623

  17. Synthesis and performance of novel magnetically separable nanospheres of titanium dioxide photocatalyst with egg-like structure

    International Nuclear Information System (INIS)

    A magnetically separable photocatalyst TiO2/SiO2/NiFe2O4 (TSN) nanosphere with egg-like structure was prepared by a unique process that combined a liquid catalytic phase transformation method, reverse micelle technique and chemical precipitation means. The prepared photocatalyst shows high photocatalytic activity for the degradation of methyl orange in water. The magnetic property measurements indicate that the photocatalyst possesses a superparamagnetic nature. It can be separated from water when an external magnetic field is added and redispersed into water solution after the external magnetic field is eliminated. It is one of the promising photocatalysts for wastewater treatment. A transmission electron microscope (TEM) and an x-ray diffractometer (XRD) were used to characterize the structure of the TSN photocatalyst. The results indicate that nickel ferrite core nanoparticles were completely encapsulated into monodisperse silica nanospheres as carrier, and titania nanoparticle aggregates were coated onto the surface of SN nanospheres, forming an imperfect TiO2 shell for photocatalysis. The SiO2 layer between the NiFe2O4 core and the TiO2 shell effectively prevents the injection of charges from TiO2 particles to NiFe2O4, which gives rise to an increase in photocatalytic activity. Moreover, the recycled TSN exhibits good repeatability of the photocatalytic activity

  18. Physical and technical aspects for 'Shelter' object rad waste magnetic separation technology

    International Nuclear Information System (INIS)

    The lava-like fuel-containing materials (LFCM) of Shelter object magnetic susceptibility temperature dependences (80-500K) were under the experimental study for the first time. The LFCM magnetic properties changeability under the isochronic annealing have been in fact detected as well

  19. Training effects induced by cycling of magnetic field in ferromagnetic rich phase-separated nanocomposite manganites

    International Nuclear Information System (INIS)

    We have carried out an experimental investigation of magneto-transport and magnetic properties of charge-ordered Pr0.67Ca0.33MnO3 (PCMO) and ferromagnetic La0.67Sr0.33MnO3 (LSMO) nanoparticles along with a nanocomposite consisting of those two types of nanoparticles. From the magneto-transport measurements, clear irreversibility is observed in the field dependence of resistance due to magnetic field cycling in the case of PCMO nanoparticles. The value of resistance increases during such a field cycling. However such an irreversibility is absent in the case of LSMO nanoparticles as well as nanocomposites. On the other hand, the magnetic measurements indicate the gradual growth of antiferromagnetic phases in all samples leading to a decrease in magnetization. These inconsistencies between magneto-transport and magnetic behaviors are attributed to the magnetic training effects. - Highlights: • The resistance value in Pr0.67Ca0.33MnO3 nanoparticles is found to increase owing to the magnetic field cycling. • No anomaly in resistance was found in Pr0.67Ca0.33MnO3–La0.67Sr0.33MnO3 nanocomposite. • Magnetic measurements indicate the training effect in nanostructure compounds

  20. The effect of particle size and colloid stability on the wet high-intensity magnetic separation of uranium from cyanidation residues

    International Nuclear Information System (INIS)

    This report describes an experimental investigation on the magnetic separation of U3O8 from various size fractions of uranium-gold tailings. High recoveries were obtained at high grades, even from the finest fraction (smaller than 25?m), and an increase in magnetic field did not improve the efficiency of separation. The use of theoretical models did not lead to the correct prediction of the limiting particle size recoverable by magnetic separation. It was shown that the presence of coarse fractions enhances the recovery of uranium from a very fine fraction, and that 'piggy-back' magnetic separation plays an important role in the capture of slimes. The results also showed that the use of a dispersant considerably improves the selectivity of the separation

  1. Theoretical analysis of a new, efficient microfluidic magnetic bead separator based on magnetic structures on multiple length scales

    DEFF Research Database (Denmark)

    Smistrup, Kristian; Bu, Minqiang; Wolff, Anders; Bruus, Henrik; Hansen, Mikkel Fougt

    2008-01-01

    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...

  2. Manipulation of magnetic phase separation and orbital occupancy in manganites by strain engineering and electric field

    Science.gov (United States)

    Cui, Bin; Song, Cheng; Pan, Feng; Key Laboratory of Advanced Materials (MOE) Team

    2015-03-01

    The modification of electronic phases in correlated oxides is one of the core issues of condensed matter. We report the reversible control of ferromagnetic phase transition in manganite films by ionic liquid gating, replicating the La1-xSrxMnO3 (LSMO) phase diagram. The formation and annihilation of an insulating and magnetically hard phase in the soft magnetic matrix, which randomly nucleates and grows across the film, is directly observed under different gate voltages (VG) . The realization of reversible metal-insulator transition in colossal magnetoresistance materials can lead to the development of four-state memories. The orbital occupancy and magnetic anisotropy of LSMO films are manipulated by VG in a reversible and quantitative manner. Positive and negative VG increases and reduces the occupancy of the orbital and magnetic anisotropy that were initially favored by strain (irrespective of tensile and compressive), respectively. This finding fills in the blank of electrical manipulation of four degrees of freedom in correlated system.

  3. Electronic and magnetic phase separation in EuB6. Fluctuation spectroscopy and nonlinear transport

    International Nuclear Information System (INIS)

    The main topics of this thesis are electrical, stationary, and time-resolved transport measurements on EuB6 as well as the further development of measuring methods and analysis procedures of the fluctuation spectroscopy. The first part of this thesis was dedicated to the further development of the already known measuring methods under application of a fast data-acquisition card. The second part deals with the electrical transport properties of EuB6 and the understanding of the coupling between charge and magnetic degrees of freedom. By means of resistance and nonlinear-transport measurements as well as fluctuation spectroscopy hypotheses of other scientists were systematically verified as well as new knowledge obtained. The magnetoresistance was studied as function of the temperature in small external magnetic fields between 1 mT and 700 mT. Measurements of the third harmonic resistance as function of the temperature show maxima at TMI and TC. Electrical-resistance fluctuations were measured without external magnetic field between 5 and 100 K as well in presence of a magnetic field between 18 K and 32 K. At constant temperature measurements of the spectral power density in external magnetic fields were performed in the temperature range from 18 K to 32 K. Highly resolving measurements of the thermal expansion coefficient showed a very strong coupling of the magnetic (polaronic) degrees of freedom to the crystal lattice.

  4. Greek red mud residue: A study of microwave reductive roasting followed by magnetic separation for a metallic iron recovery process

    Energy Technology Data Exchange (ETDEWEB)

    Samouhos, Michail, E-mail: msamouhos@metal.ntua.gr [School of Mining and Metallurgical Engineering, Laboratory of Metallurgy, National Technical University of Athens, 9, Iroon Polytechniou Street, 157 80 Zografou, Athens (Greece); Taxiarchou, Maria; Tsakiridis, Petros E. [School of Mining and Metallurgical Engineering, Laboratory of Metallurgy, National Technical University of Athens, 9, Iroon Polytechniou Street, 157 80 Zografou, Athens (Greece); Potiriadis, Konstantinos [Greek Atomic Energy Commission (GAEC), Patriarxou Grigoriou and Neapoleos, P.O. Box 60092, 15310 Agia Paraskevi, Athens (Greece)

    2013-06-15

    Highlights: Microwave reduction of a red mud. Measurement of real and imaginary permittivity of red mudlignite mixture. Red mud was subjected to reductive roasting and magnetic separation processes. The optimum concentrate contains 31.6% iron with a 69.3% metallization degree. {sup 226}Ra, {sup 228}Ra, {sup 238}U, {sup 228}Th, {sup 232}Th, {sup 40}K were detected in the magnetic concentrate. -- Abstract: The present research work is focused on the development of an alternative microwave reductive roasting process of red mud using lignite (30.15 wt.% C{sub fix}), followed by wet magnetic separation, in order to produce a raw material suitable for sponge or cast iron production. The reduction degree of iron was controlled by both the reductive agent content and the microwave heating time. The reduction followed the Fe{sub 2}O{sub 3} ? Fe{sub 3}O{sub 4} ? FeO ? Fe sequence. The dielectric constants [real (??) and imaginary (??) permittivities] of red mudlignite mixture were determined at 2.45 GHz, in the temperature range of 251100 C. The effect of parameters such as temperature, intensity of reducing conditions, intensity of magnetic field and dispersing agent addition rate on the result of both processes was investigated. The phase's transformations in reduction process with microwave heating were determined by X-ray diffraction analysis (XRD) in combination with thermogravimetric/differential thermal analysis (TGA/DTA). The microstructural and morphological characterization of the produced calcines was carried out by scanning electron microscopy (SEM). At the optimum conditions a magnetic concentrate with total iron concentration of 35.15 and 69.3 wt.% metallization degree was obtained.

  5. Maximizing haematite recovery within a fine and wide particle-size distribution using wet high-intensity magnetic separation

    Scientific Electronic Library Online (English)

    M, Dworzanowski.

    2014-07-01

    Full Text Available The physical beneficiation of iron ore that has a wide particle-size distribution is problematic, regardless of the process applied, whether dense medium separation, gravity concentration, magnetic separation, or flotation. The problem of particle size is further compounded when there is a significa [...] nt -10 m fraction. Generally the approach to a wide particle-size distribution is to split into narrower size ranges and treat each separately. More often than not the -10 m fraction is not treated but discarded. This approach results in a more complicated and expensive flow sheet and the loss of any potential value in the -10 m fraction. Wet high-intensity magnetic separation (WHIMS) bench-scale test work was conducted on a haematite-rich material with a particle size of -200 m What made this material different was that it contained a 60% -10 m fraction, hence discarding the -10 m material was not an option. The objective of the test work was to determine how to maximize the recovery of the haematite across the full particle size range. Given the unusual particle size distribution, it was concluded that WHIMS would be the only practical beneficiation route. The -200 +10 m and -10 m fractions were treated separately and together under varying WHIMS conditions. For a given concentrate grade, the mass yield obtained was greater when the total particle-size distribution was treated. The inferred optimum conditions, using the same material, were tested on a pilot-scale WHIMS and similar results were obtained.

  6. A pH-responsive and magnetically separable dynamic system for efficient removal of highly dilute antibiotics in water.

    Science.gov (United States)

    Liu, Wanpeng; Ma, Jianqing; Shen, Chensi; Wen, Yuezhong; Liu, Weiping

    2016-03-01

    In order to control the antibiotic-related crisis and reduce the negative impacts on the environment and human health, it is urgent to develop effective technologies to eliminate residual antibiotics in water. Herein, we successfully fabricated a novel, pH-responsive and magnetically separable dynamic system for micropollutant adsorption and oxidation degradation in graphene oxide (GO)/nanoscale zero-valent iron (nZVI) composite with macroscopic structure. The pH-responsive self-assembly behavior of GO/nZVI composite was explored. The macroscopic structure of GO/nZVI composite serves as an excellent adsorbent for antibiotic removal in water. The adsorption process is fast and highly efficient even in high salty and humic acid containing water under acid to neutral conditions. After removal antibiotics, GO/nZVI composite is conveniently separated by magnetic system and put into alkaline solution (pH>9) for adsorbent regeneration. Interestingly, it is found that at pH>9, GO/nZVI composite disassembles partly upon increasing pH values, leading to the elution of antibiotics for efficient antibiotics degradation by ozonization. More importantly, this pH-responsive GO/nZVI system exhibits high removal efficiency, high stability, reusability and easily separation, making it a promising method for treatment of water with micropollutants. PMID:26724436

  7. Phase separation and magnetic order in K-doped iron selenide superconductor

    Science.gov (United States)

    Li, Wei; Ding, Hao; Deng, Peng; Chang, Kai; Song, Canli; He, Ke; Wang, Lili; Ma, Xucun; Hu, Jiang-Ping; Chen, Xi; Xue, Qi-Kun

    2012-02-01

    The newly discovered alkali-doped iron selenide superconductors not only reach a superconducting transition temperature as high as 32K, but also exhibit unique characteristics that are absent from other iron-based superconductors, such as antiferromagnetically ordered insulating phases, extremely high Nel transition temperatures and the presence of Fe vacancies and ordering. These features have generated considerable excitement as well as confusion, regarding the delicate interplay between Fe vacancies, magnetism and superconductivity. Here we report on molecular beam epitaxy growth of high-quality KxFe2-ySe2 thin films and in situ low-temperature scanning tunnelling microscope measurement of their atomic and electronic structures. We demonstrate that a KxFe2-ySe2 sample contains two distinct phases: an insulating phase with well-defined order of Fe vacancies, and a superconducting KFe2Se2 phase containing no Fe vacancies. An individual Fe vacancy can locally destroy superconductivity in a similar way to a magnetic impurity in conventional superconductors. Measurement of the magnetic-field dependence of the Fe-vacancy-induced bound states reveals a magnetically related bipartite order in the tetragonal iron lattice. These findings elucidate the existing controversies on this new superconductor and provide atomistic information on the interplay between magnetism and superconductivity in iron-based superconductors.

  8. New high performance hybrid magnet plates for DNA separation andbio-technology applications

    Energy Technology Data Exchange (ETDEWEB)

    Humphries, David; Pollard, Martin; Elkin, Chris; Petermann, Karl; Reiter, Charles; Cepeda, Mario

    2004-08-02

    A new class of magnet plates for biological and industrial applications has recently been developed at the D.O.E. Joint Genome Institute and Lawrence Berkeley National Laboratory (JGI/LBNL). These devices utilize hybrid technology that combines linear permanent magnet material and ferromagnetic material to produce significantly higher fields and gradients than currently available commercial magnet plates. These hybrid structures incorporate ferromagnetic poles that can be easily shaped to produce complex field distributions for specialized applications. The higher maximum fields and strong gradients of the hybrid structures result in greater holding forces on magnetized targets that are being processed as well as faster draw-down. Current development versions of these magnet plates have exhibited maximum fields in excess of 9000.0 Gauss. The design of these structures is easily scalable to allow for field increases to significantly above 1.0 tesla (10000.0gauss). Author's note: 11000.0 Gauss peak fields have been achieved as of January 2005.

  9. Quantitative characterization of magnetic separators: Comparison of systems with and without integrated microfluidic mixers

    DEFF Research Database (Denmark)

    Lund-Olesen, Torsten; Bruus, Henrik; Hansen, Mikkel Fougt

    2006-01-01

    and magnetized by an external magnetic field. In one of the systems, a staggered herringbone microfluidic mixer is integrated in the channel. The characterization of the systems includes magnetic measurements of the capture-and-release efficiencies, estimates of distributions of captured beads in a...... channel from micrographs, and simulations and analytical models of bead trajectories, capture efficiencies, and capture distributions. We show that the efficiencies of both systems compare favorably to those in the literature. For the studied geometries, the mixer is demonstrated to increase the bead...... capture-and-release efficiency for a fixed flow rate by up to a factor of two. Moreover, high capture efficiencies can be achieved in the system with mixer at up to ten times higher flow rates than in the system without mixer....

  10. Magnetic and noble metal nanocomposites for separation and optical detection of biological species.

    Science.gov (United States)

    Bagga, K; Brougham, D F; Keyes, T E; Brabazon, D

    2015-11-14

    Nanoalloys and nanocomposites are widely studied classes of nanomaterials within the context of biological systems. They are of immense interest because of the possibility of tuning the optical, magnetic, electronic and chemical properties through particle composition and internal architecture. In principle these properties can therefore be optimized for application in biological detections such as of DNA sequences, bacteria, viruses, antibodies, antigens, and cancer cells. This article presents an overview of methods currently used for nanoalloy and nanocomposite synthesis and characterisation, focusing on Au-Ag and FexOy@Au structures as primary components in detection platforms for plasmonic and magnetically enabled plasmonic bio-sensing. PMID:26024367

  11. Superconductivity, metastability and magnetic field induced phase separation in the atomic limit of the Penson-Kolb-Hubbard model

    CERN Document Server

    Kapcia, Konrad Jerzy

    2014-01-01

    We present the analysis of paramagnetic effects of magnetic field ($B$) (Zeeman term) in the zero-bandwidth limit of the extended Hubbard model for arbitrary chemical potential $\\mu$ and electron density $n$. The effective Hamiltonian considered consists of the on-site interaction $U$ and the intersite charge exchange term $I$, determining the hopping of electron pairs between nearest-neighbour sites. The model has been analyzed within the variational approach, which treats the on-site interaction term exactly and the intersite interactions within the mean-field approximation (rigorous in the limit of infinite dimensions $d\\rightarrow+\\infty$). In this report we focus on metastable phases as well as phase separated (PS) states involving superconducting (SS) and nonordered (NO) phases and determine their ranges of occurrence for $U/I_0=1.05$ ($I_0=zI$) in the presence of magnetic field $B\

  12. Application of Graphene Oxide-MnFe2O4 Magnetic Nanohybrids as Magnetically Separable Adsorbent for Highly Efficient Removal of Arsenic from Water

    Science.gov (United States)

    Huong, Pham Thi Lan; Huy, Le Thanh; Phan, Vu Ngoc; Huy, Tran Quang; Nam, Man Hoai; Lam, Vu Dinh; Le, Anh-Tuan

    2016-01-01

    In this work, a functional magnetic nanohybrid consisting of manganese ferrite magnetic nanoparticles (MnFe2O4) deposited onto graphene oxide (GO) nanosheets was successfully synthesized using a modified co-precipitation method. The as-prepared GO-MnFe2O4 magnetic nanohybrids were characterized using x-ray diffraction, transmission electron microscopy, Fourier transformed infrared spectroscopy, and vibrating sample magnetometer measurements. Adsorption experiments were performed to evaluate the adsorption capacities and efficient removal of arsenic of the nanohybrid and compared with bare MnFe2O4 nanoparticles and GO nanosheets. Our obtained results reveal that the adsorption process of the nanohybrids was well fitted with a pseudo-second-order kinetic equation and a Freundlich isotherm model; the maximum adsorption capacity and removal efficiency of the nanohybrids obtained ~240.385 mg/g and 99.9% with a fast response of equilibrium adsorption time ~20 min. The larger adsorption capacity and shorter equilibrium time of the GO-MnFe2O4 nanohybrids showed better performance than that of bare MnFe2O4 nanoparticles and GO nanosheets. The advantages of reusability, magnetic separation, high removal efficiency, and quick kinetics make these nanohybrids very promising as low-cost adsorbents for fast and effective removal of arsenic from water.

  13. The GSI projectile fragment separator (FRS): a versatile magnetic system for relativistic heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Geissel, H.; Armbruster, P.; Behr, K.H.; Bruenle, A.; Burkard, K.; Chen, M.; Folger, H.; Franczak, B.; Keller, H.; Klepper, O.; Langenbeck, B.; Nickel, F.; Pfeng, E.; Pfuetzner, M.; Roeckl, E.; Rykaczewski, K.; Schall, I.; Schardt, D.; Scheidenberger, C.; Schmidt, K.H.; Schroeter, A.; Schwab, T.; Suemmerer, K.; Weber, M.; Muenzenberg, G. (Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany)); Brohm, T.; Clerc, H.G.; Fauerbach, M.; Gaimard, J.J.; Grewe, A.; Hanelt, E.; Knoedler, B.; Steiner, M.; Voss, B.; Weckenmann, J.; Ziegler, C. (TH Darmstadt (Germany). Inst. fuer Kernphysik); Magel, A.; Wollnik, H. (Giessen Univ. (Germany)); Dufour, J.P. (CEN, 33 - Bordeaux (France)); Fujita, Y. (Osaka Univ., Toyonaka (Japan). Coll. of General Education); Vieira, D.J. (Los Alamos National Lab., NM (United States)); Sherrill, B. (NSCL, East Lansing, MI (United States))

    1992-08-01

    The projectile fragment separator FRS designed for research and applied studies with relativistic heavy ions was installed at GSI as a part of the new high-energy SIS/ESR accelerator facility. This high-resolution forward spectrometer has been successfully used in first atomic and nuclear physics experiments using neon, argon, krypton, xenon, and gold beams in the energy range from 500 to 2000 MeV/u. For the first time relativistic xenon and gold fragments have been isotopically separated. In this contribution we describe first experiments characterizing the performance of the spectrometer. (orig.).

  14. Separation of fields and 3D inversion of gravity and magnetic data for the Thuringian Basin, Germany

    Science.gov (United States)

    Prutkin, Ilya; Bleibinhaus, Florian; Jahr, Thomas

    2013-04-01

    We have developed a new algorithm for the 3D inversion of potential field data, and we have applied it to gravity and magnetic data from the Thuringian Basin in Mid-Germany to obtain additional constraints for the basin structure. A detailed structural model is an essential boundary condition for models of fluid transport, one of the central goals of the INFLUINS project. Our inversion approach separates the sources (i) in depth using upward and downward continuation, (ii) in the lateral direction by means of approximation with a field generated by 3D line segments, and (iii) according to the density and magnetization contrast on the basis of a pseudo-gravity calculation. Potential field anomalies are modeled either as depth variations of a density interface, or as restricted 3D bodies. We have inverted gravity and magnetic data from the Thuringian Basin for short, intermediate and long wavelengths separately. We assume that the intermediate wavelengths are generated by anomalies in the crystalline basement (~10 km depth), while the short wavelength structure is caused by the variable thickness and structure of the basin sediments. Our 3D model for the main intermediate sources includes three low-density bodies that we interpret as granitic intrusions, and a density interface with topography within the crystalline basement. A significant arc-shaped anomaly, visible both in gravity and in magnetic data, is modeled as an uplift of the crystalline crust. More detailed models for the Tannrodaer anticline are indicative of salt tectonics: the corresponding 3D model includes an uplift of Bundsandstein and a salt deposit. We are currently working on including further constraints on the basin structure from a recently acquired reflection seismic survey.

  15. Magnetic IDA-modified hydrophilic methacrylate-based polymer microspheres for IMAC protein separation.

    Czech Academy of Sciences Publication Activity Database

    P?ikryl, P.; Hork, Daniel; Tich, M.; Ku?erov, Z.

    2006-01-01

    Ro?. 29, ?. 16 (2006), s. 2541-2549. ISSN 1615-9306 R&D Projects: GA ?R GA203/05/0241 Institutional research plan: CEZ:AV0Z40500505 Keywords : human IgG * hydrophilic magnetic microspheres * iminodiacetic acid Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.535, year: 2006

  16. Studies in matter antimatter separation and in the origin of lunar magnetism

    Science.gov (United States)

    Barker, W. A.; Greeley, R.; Parkin, C.; Aggarwal, H.; Schultz, P.

    1975-01-01

    A progress report, covering lunar and planetary research is introduced. Data cover lunar ionospheric models, lunar and planetary geology, and lunar magnetism. Wind tunnel simulations of Mars aeolian problems and a comparative study of basaltic analogs of Lunar and Martial volcanic features was discussed.

  17. Magnetic BaFe12O19 nanofiber filter for effective separation of Fe3O4 nanoparticles and removal of arsenic

    International Nuclear Information System (INIS)

    Magnetic nanoparticles are promising in applications where magnetic separation is intended, although material losses via leaching mechanisms are often inevitable. Magnetic separations with widely available permanent magnets can effectively trap particles, leading to a complete removal of used or waste particles. In this report, we first demonstrate the synthesis of the thinnest (112.716.4nm) and most magnetic (71.96emug?1) barium hexaferrite (BaFe12O19, BHFfridge magnet) via an organic solvent-free electrospinning procedure. When the fibers are then packed into a column, they clearly remove 12nm magnetite (Fe3O4) nanoparticles quantitatively. The same BHF cartridge also removes more than 99.9% As-treated magnetite nanoparticles at capacities up to 70 times of its weight. As a result, one liter of 150?gL?1 As-contaminated water can be purified rapidly at a material cost of less than 2 US cents

  18. Mass separation of a multicomponent plasma flow in a curvilinear magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Papernyi, V. L.; Krasov, V. I. [Irkutsk State University (Russian Federation)

    2011-11-15

    The motion of a metal plasma flow of a vacuum-arc discharge in a transportation plasma-optical system with a curvilinear magnetic field is studied experimentally and numerically. The flow position at the output of the system is shown to depend on the cathode material, which determines the mass-to-charge ratio of plasma ions. As a result, the flow with a greater ion mass-to-charge ratio moves along a trajectory with a larger radius. A similar effect is observed in the case of a multicomponent plasma flow generated by a composite cathode. The results of two-fluid MHD simulations of a plasma flow propagating in a curvilinear magnetic field agree qualitatively with the experimental data.

  19. Isolation of Murine Postnatal Brain Microglia for Phenotypic Characterization Using Magnetic Cell Separation Technology

    OpenAIRE

    Harms, Ashley S; Tansey, Mal G.

    2013-01-01

    To shorten the time between brain harvesting and microglia isolation, and characterization we utilized the MACS neural dissociation kit followed by OctoMACS CD11b magnetic bead isolation technique to positively select for brain microglia expressing the pan-microglial marker Cd11b, a key subunit of the Membrane Attack Complex (MAC). This protocol yields a viable and highly pure (> 95%) microglial population of approximately 500,000 cells per pup that is amenable for in vitro characterization...

  20. Calculating Separate Magnetic Free Energy Estimates for Active Regions Producing Multiple Flares: NOAA AR11158

    CERN Document Server

    Tarr, Lucas A; Millhouse, Margaret

    2013-01-01

    It is well known that photospheric flux emergence is an important process for stressing coronal fields and storing magnetic free energy, which may then be released during a flare. The \\emph{Helioseismic and Magnetic Imager} (HMI) onboard the \\emph{Solar Dynamics Observatory} (SDO) captured the entire emergence of NOAA AR 11158. This region emerged as two distinct bipoles, possibly connected underneath the photosphere, yet characterized by different photospheric field evolutions and fluxes. The combined active region complex produced 15 GOES C--class, 2 M--class, and the X2.2 Valentine's Day Flare during the four days after initial emergence on February 12th, 2011. The M and X class flares are of particular interest because they are nonhomologous, involving different subregions of the active region. We use a Magnetic Charge Topology together with the Minimum Current Corona model of the coronal field to model field evolution of the complex. Combining this with observations of flare ribbons in the 1600\\AA\\ chann...

  1. Novel Monoclonal Antibody and Peptide Binders for Mycobacterium avium subsp. paratuberculosis and Their Application for Magnetic Separation.

    Science.gov (United States)

    O'Brien, Lorna M; Stewart, Linda D; Strain, Sam A J; Grant, Irene R

    2016-01-01

    The generation of novel Mycobacterium avium subsp. paratuberculosis (MAP)-specific monoclonal antibodies and phage-display derived peptide binders, along with their application for the magnetic separation (MS) of MAP cells, is described. Our aim was to achieve even greater MAP capture capability than is possible with peptide-mediated magnetic separation (PMS) using a 50:50 mix of biotinylated-aMp3 and biotinylated-aMptD peptide-coated beads. Gamma-irradiated whole MAP cells and ethanol extracted antigens (EEA) from these cells were used to elicit an immune response and as phage-display biopanning targets. A range of novel binders was obtained and coated onto paramagnetic beads, both individually and in various combinations, for MS evaluation. IS900 PCR was employed after MS to provide quick results. Capture sensitivity was assessed using a range of MAP concentrations after which the most promising beads were tested for their specificity for MAP, by performing MS followed by culture using 10 other Mycobacterium species. Magnetic beads coated with the biotinylated EEA402 peptide demonstrated a greater level of MAP capture than the current PMS method, even when low numbers of MAP (PMS method, but with little cross-reactivity to other Mycobacterium spp. Therefore, two new MS protocols are suggested, the application of which would be dependent upon the required endpoint. Biotinylated EEA402-coated beads could potentially be used with a MAP-specific PCR to ensure detection specificity, while beads coated with 6G11 and 15D10 monoclonal antibodies could be used with culture or the phage amplification assay. PMID:26815790

  2. A study on the purification of primary coolant in a nuclear power plant using a magnetic filter - electrodeionization hybrid separation system

    International Nuclear Information System (INIS)

    A study on the purification of primary coolant system in a nuclear power plant is carried out using magnetic filter - electrodeionization hybrid separation process. Magnetic filter system with 3000 Gauss permanent manget is used for the removal of CRUD (Chalk River Unidentified Deposit) and electrodeionization for ionic nuclide species. The removal and transport mechanism of nickel ion in an electrodeionization system is explained. The developed magnetic filter - electrodeionization hybrid separation process showed high removal rate over 98 %. The results suggested the applicable possibility for the purification of primary coolant system in a nuclear power plant

  3. Greek "red mud" residue: a study of microwave reductive roasting followed by magnetic separation for a metallic iron recovery process.

    Science.gov (United States)

    Samouhos, Michail; Taxiarchou, Maria; Tsakiridis, Petros E; Potiriadis, Konstantinos

    2013-06-15

    The present research work is focused on the development of an alternative microwave reductive roasting process of red mud using lignite (30.15 wt.%Cfix), followed by wet magnetic separation, in order to produce a raw material suitable for sponge or cast iron production. The reduction degree of iron was controlled by both the reductive agent content and the microwave heating time. The reduction followed the Fe?O? ? Fe?O? ? FeO ? Fe sequence. The dielectric constants [real (?') and imaginary (??) permittivities] of red mud-lignite mixture were determined at 2.45 GHz, in the temperature range of 25-1100 C. The effect of parameters such as temperature, intensity of reducing conditions, intensity of magnetic field and dispersing agent addition rate on the result of both processes was investigated. The phase's transformations in reduction process with microwave heating were determined by X-ray diffraction analysis (XRD) in combination with thermogravimetric/differential thermal analysis (TGA/DTA). The microstructural and morphological characterization of the produced calcines was carried out by scanning electron microscopy (SEM). At the optimum conditions a magnetic concentrate with total iron concentration of 35.15 and 69.3 wt.% metallization degree was obtained. PMID:23611801

  4. Wet high-intensity magnetic separation for the concentration of Witwatersrand gold-uranium ores and residues

    International Nuclear Information System (INIS)

    Wet high-intensity magnetic separation (WHIMS) for the concentration of gold and uranium was tested on many Witwatersrand cyanidation residues, and on some ores and flotation tailings. The results varied, but many indicated recoveries of over 60 per cent of the gold and uranium. The main source of loss is the inefficiency of WHIMS for material of smaller particle size than 20?m. The recoveries in the continuous tests were lower than those in the batch tests. The continuous tests indicated an operational difficulty that could be experienced in practice, namely the tendency for wood chips and ferromagnetic particles to block the matrix of the separator. It was decided that a solution to the problem lies in the modification of the separator to allow continuous removal of the matrix for cleaning. A system has been developed for this purpose and is being demonstrated on a pilot-plant scale. Promising results were obtained in tests on a process that combines a coarse grind, gravity concentration, and WHIMS. In the gravity-concentration step, considerable recoveries, generally over 50 per cent, of high-grade pyrite were obtained, together with high recoveries of gold and moderate, but possibly important, recoveries of uranium. A simple model describing the operation of the WHIMS machine in terms of the operating parameters is described. This should reduce the amount of empirical testwork required for the optimization of operating conditions and should provide a basis for scale-up calculations. The economics of the WHIMS process is discussed

  5. Magnetic separation of heavy metal ions and evaluation based on surface-enhanced Raman spectroscopy: copper(II) ions as a case study.

    Science.gov (United States)

    Yan, Xue; Zhang, Xue-Jiao; Yuan, Ya-Xian; Han, San-Yang; Xu, Min-Min; Gu, Ren'ao; Yao, Jian-Lin

    2013-11-01

    A new approach was developed for the magnetic separation of copper(II) ions with easy operation and high efficiency. p-Mercaptobenzoic acid served as the modified tag of Fe2O3@Au nanoparticles both for the chelation ligand and Raman reporter. Through the chelation between the copper(II) ions and carboxyl groups on the gold shell, the Fe2O3@Au nanoparticles aggregated to form networks that were enriched and separated from the solution by a magnet. A significant decrease in the concentration of copper(II) ions in the supernatant solution was observed. An extremely sensitive method based on surface-enhanced Raman spectroscopy was employed to detect free copper(II) ions that remained after the magnetic separation, and thus to evaluate the separation efficiency. The results indicated the intensities of the surface-enhanced Raman spectroscopy bands from p-mercaptobenzoic acid were dependent on the concentration of copper(II) ions, and the concentration was decreased by several orders of magnitude after the magnetic separation. The present protocol effectively decreased the total amount of heavy metal ions in the solution. This approach opens a potential application in the magnetic separation and highly sensitive detection of heavy metal ions. PMID:24106161

  6. Acid-Stable Magnetic Core?Shell Nanoparticles for the Separation of Rare Earths

    OpenAIRE

    Dupont, David; Luyten, Jakob; Bloemen, Maarten; Verbiest, Thierry; Binnemans, Koen

    2014-01-01

    Coreshell Fe3O4@SiO2 nanoparticles were prepared with a modified Stber method and functionalized with N-[(3-trimethoxysilyl)propyl]ethylenediamine triacetic acid (TMS-EDTA). The synthesis was optimized to make coreshell nanoparticles with homogeneous and thin SiO2 shells (4.8 0.5 nm) around highly superparamagnetic Fe3O4 cores (14.5 3.0 nm). The coreshell Fe3O4@SiO2(TMS-EDTA) nanoparticles were then used for the extraction and separation of rare-earth ions. By comparing them with prev...

  7. Preparation of magnetic carbon nanotubes for separation of pyrethroids from tea samples

    International Nuclear Information System (INIS)

    Magnetic carbon nanotubes (MCNTs) have been synthesized by chemical deposition of Fe3O4 nanoparticles onto carbon nanotubes. They were characterized by Fourier transform infrared spectroscopy, scanning electron microscope, X-ray diffraction and physical property measurement system. The MCNTs were used as the sorbents for the extraction of pyrethroids including beta-cyfluthrin, cyhalothrin and cyphenothrin from tea samples. The extraction conditions, such as the amount of magnetic sorbent, shaking time and rate, washing and eluting solution have been fully investigated. The analytes desorbed from MCNTs were determined by HPLC with UV detection. Under the optimal conditions, the linearity of the method is in the range of 0.05-25 ?g g-1. The limits of detection of the three pyrethroids are 0.017, 0.010 and 0.018 ?g g-1, respectively. The relative standard deviations of within- and between-day range from 3.5 % to 6.4 %, and from 4.5 % to 29 7.3 %, respectively. In all three spiked levels (0.05, 0.5 and 5 ?g g-1), the recoveries of pyrethroids are in the range of 82.2 %-94.4 %. This method is much faster and more effective than traditional methods, and it is promising for the analysis of pesticides residues. (author)

  8. Magnetically separable polymer (Mag-MIP) for selective analysis of biotin in food samples.

    Science.gov (United States)

    Uzuriaga-Sánchez, Rosario Josefina; Khan, Sabir; Wong, Ademar; Picasso, Gino; Pividori, Maria Isabel; Sotomayor, Maria Del Pilar Taboada

    2016-01-01

    This work presents an efficient method for the preparation of magnetic nanoparticles modified with molecularly imprinted polymers (Mag-MIP) through core-shell method for the determination of biotin in milk food samples. The functional monomer acrylic acid was selected from molecular modeling, EGDMA was used as cross-linking monomer and AIBN as radical initiator. The Mag-MIP and Mag-NIP were characterized by FTIR, magnetic hysteresis, XRD, SEM and N2-sorption measurements. The capacity of Mag-MIP for biotin adsorption, its kinetics and selectivity were studied in detail. The adsorption data was well described by Freundlich isotherm model with adsorption equilibrium constant (KF) of 1.46 mL g(-1). The selectivity experiments revealed that prepared Mag-MIP had higher selectivity toward biotin compared to other molecules with different chemical structure. The material was successfully applied for the determination of biotin in diverse milk samples using HPLC for quantification of the analyte, obtaining the mean value of 87.4% recovery. PMID:26212997

  9. Enhanced defluoridation and facile separation of magnetic nano-hydroxyapatite/alginate composite.

    Science.gov (United States)

    Pandi, Kalimuthu; Viswanathan, Natrayasamy

    2015-09-01

    In this research study, a new magnetic biosorbent was developed by the fabrication of magnetic Fe3O4 particles on nano-hydroxyapatite(n-HAp)/alginate (Alg) composite (Fe3O4@n-HApAlg composite) for defluoridation in batch mode. The synthesized Fe3O4@n-HApAlg biocomposite possess an enhanced defluoridation capacity (DC) of 4050 mgF(-)/kg when compare to n-HApAlg composite, Fe3O4@n-HAp composite, n-HAp and Fe3O4 which possesses the DCs of 3870, 2469, 1296 and 1050 mgF(-)/kg respectively. The structural changes of the sorbent, before and after fluoride sorption were studied using FTIR, XRD and SEM with EDAX techniques. There are various physico-chemical parameters such as contact time, pH, co-existing anions, initial fluoride concentration and temperature were optimized for maximum fluoride removal. The equilibrium data was well modeled by Freundlich, Langmuir, Dubinin-Radushkevich (D-R) and Temkin isotherms. The present system follows Dubinin-Radushkevich isotherm model. The thermodynamic parameters reveals that the feasibility, spontaneity and endothermic nature of fluoride sorption. The performance and efficiency of the adsorbent material was examined with water samples collected from fluoride endemic areas namely Reddiyarchatram and Ammapatti in Dindigul District of Tamil Nadu using standard protocols. PMID:26092170

  10. Hour-glass magnetic excitations induced by nanoscopic phase separation in cobalt oxides La$_{2-x}$Sr$_x$CoO$_4$

    CERN Document Server

    Drees, Y; Ricci, A; Rotter, M; Schmidt, W; Lamago, D; Sobolev, O; Rtt, U; Gutowski, O; Sprung, M; Piovano, A; Castellan, J P; Komarek, A C

    2015-01-01

    The magnetic excitations in the cuprate superconductors might be essential for an understanding of high-temperature superconductivity. In these cuprate superconductors the magnetic excitation spectrum resembles an hour-glass and certain resonant magnetic excitations within are believed to be connected to the pairing mechanism which is corroborated by the observation of a universal linear scaling of superconducting gap and magnetic resonance energy. So far, charge stripes are widely believed to be involved in the physics of hour-glass spectra. Here we study an isostructural cobaltate that also exhibits an hour-glass magnetic spectrum. Instead of the expected charge stripe order we observe nano phase separation and unravel a microscopically split origin of hour-glass spectra on the nano scale pointing to a connection between the magnetic resonance peak and the spin gap originating in islands of the antiferromagnetic parent insulator. Our findings open new ways to theories of magnetic excitations and superconduc...

  11. Levitation Performance of Two Opposed Permanent Magnet Pole-Pair Separated Conical Bearingless Motors

    Science.gov (United States)

    Kascak, Peter; Jansen, Ralph; Dever, Timothy; Nagorny, Aleksandr; Loparo, Kenneth

    2013-01-01

    In standard motor applications, rotor suspension with traditional mechanical bearings represents the most economical solution. However, in certain high performance applications, rotor suspension without contacting bearings is either required or highly beneficial. Examples include applications requiring very high speed or extreme environment operation, or with limited access for maintenance. This paper expands upon a novel bearingless motor concept, in which two motors with opposing conical air-gaps are used to achieve full five-axis levitation and rotation of the rotor. Force in this motor is created by deliberately leaving the motor s pole-pairs unconnected, which allows the creation of different d-axis flux in each pole pair. This flux imbalance is used to create lateral force. This approach is different than previous bearingless motor designs, which require separate windings for levitation and rotation. This paper examines the predicted and achieved suspension performance of a fully levitated prototype bearingless system.

  12. Phase separation instabilities and magnetism in two dimensional square and honeycomb Hubbard model

    Science.gov (United States)

    Kocharian, A. N.; Fang, Kun; Fernando, G. W.; Balatsky, A. V.

    2015-06-01

    The variational cluster approximation is applied to rigorously calculate intrinsic local electron correlations in bipartite square and honeycomb Hubbard lattices. The Mott-Hubbard gap at half filling is manifested by a smooth metal-insulator transition in both lattices in agreement with the generic two-dimensional phase diagram. However, a density variation with the chemical potential shows the distinct structural differences away from half filling. The square lattice exhibits electron density discontinuity accompanied with spontaneous transition from antiferromagnetic Mott-Hubbard insulator into nonmagnetic metal. The spectral density anomaly and spin susceptibility peaks also are signaling on coexistence of hole rich metallic and hole poor insulating regions. In contrast, honeycomb lattice does not show density anomaly but displays a smooth transition with continuous evolution of a homogenous metallic state. These calculations provide strong evidence for spontaneous phase separation instability found in our quantum cluster calculations at moderate U

  13. Cryo magnetic separation adaptation to environment technologies: application to industrial effluents; Adaptation de la separation cryomagnetique aux technologies de l`environnement: application a l`epuration d`effluents liquides industriels

    Energy Technology Data Exchange (ETDEWEB)

    Bureau, V.

    1993-12-20

    Cryomagnetic separation adaptation to environment technologies application to industrial liquid effluents. The performance, obtained by superconducting high filed - high gradient magnetic separation, permitted to foresee the magnetic treatment of heavy metals in rinse waters, derived from the surface finishing industry. The paramagnetic ions, precipitated in basic media as hydroxides, present a very hydrated amorphous structure, which masks their subjacent magnetic properties. Coprecipitation of a `magnetic carrier`, jointly with the heavy metals, has been studied: ferric chloride forms in basic media, an hydrated iron oxide. Its structure is of the goethite type, and it stabilizes as hematite. The magnetic susceptibility of the obtained product is still weak and its crystalline structure is not enough affirmative to utilize magnetic filtration with efficiency. Mixture of ferrous sulphate and ferric chloride forms, in a basic media, an hydrated magnetite. Initial ideal ratio between divalent iron and trivalent iron, varies between 0,5 and 1,2. This mixture, coprecipitated with the heavy metals, permits to optimize the magnetic cleaning of the fluids in a high field - high gradient filter. (author)

  14. Colorimetric aptasensing of ochratoxin A using Au@Fe3O4 nanoparticles as signal indicator and magnetic separator.

    Science.gov (United States)

    Wang, Chengquan; Qian, Jing; Wang, Kun; Yang, Xingwang; Liu, Qian; Hao, Nan; Wang, Chengke; Dong, Xiaoya; Huang, Xingyi

    2016-03-15

    Gold nanoparticles (Au NPs) doped Fe3O4 (Au@Fe3O4) NPs have been synthesized by a facile one-step solvothermal method. The peroxidase-like activity of Au@Fe3O4 NPs was effectively enhanced due to the synergistic effect between the Fe3O4 NPs and Au NPs. On this basis, an efficient colorimetric aptasensor has been developed using the intrinsic dual functionality of the Au@Fe3O4 NPs as signal indicator and magnetic separator. Initially, the amino-modified aptamer specific for a typical mycotoxin, ochratoxin A (OTA), was surface confined on the amino-terminated glass beads surafce using glutaraldehyde as a linker. Subsequently, the amino-modified capture DNA (cDNA) was labeled with the amino-functionalized Au@Fe3O4 NPs and the aptasensor was thus fabricated through the hybridization reaction between cDNA and the aptamers. While upon OTA addition, aptamers preferred to form the OTA-aptamer complex and the Au@Fe3O4 NPs linked on the cDNA were released into the bulk solution. Through a simple magnetic separation, the collected Au@Fe3O4 NPs can produce a blue colored solution in the presence of 3,3',5,5'-tetramethylbenzidine and H2O2. When the reaction was terminated by addition of H(+) ions, the blue product could be changed into a yellow one with higher absorption intensity. This colorimetric aptasensor can detect as low as 30 pgmL(-1) OTA with high specificity. To the best of our knowledge, the present colorimetric aptasensor is the first attempt to use the peroxidase-like activity of nanomaterial for OTA detection, which may provide an acttractive path toward routine quality control of food safety. PMID:26583358

  15. Photocatalytic degradation of methylene blue on magnetically separable MgFe{sub 2}O{sub 4} under visible light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Shahid, Muhammad [Material Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900 (Saudi Arabia); Jingling, Liu [BK21 Physics Research Division, SKKU Advanced Institute of Nanotechnology, Institute of Basic Sciences, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Ali, Zahid [National Institute of Lasers and Optronics, Nilore, Islamabad (Pakistan); Shakir, Imran [Sustainable Energy Technologies (SET) Center, King Saud University, Riyadh (Saudi Arabia); Warsi, Muhammad Farooq, E-mail: farooq.warsi@iub.edu.pk [Chemistry Department, Baghdad-ul-Jaded Campus, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Parveen, Riffat [Institute of Chemistry, University of the Punjab, Lahore (Pakistan); Nadeem, Muhammad [Department of Chemistry, University of Agriculture, Faisalabad 38040, Punjab (Pakistan)

    2013-05-15

    A magnetically separable single-phase MgFe{sub 2}O{sub 4} photocatalyst with a spinel crystal structure was synthesized by using the solid-state reaction method. The formation of spinel structure is confirmed by X-ray diffraction and Fourier transform infrared spectroscopy. The magnetic measurements showed that the photocatalyst material can be separated from water when an external magnetic field is added and redispersed into water solution after the external magnetic field is eliminated. It is one of the promising photocatalysts for waste water treatment. The photocatalytic activity of MgFe{sub 2}O{sub 4} was investigated by using the photo-decomposition of methylene blue dye under visible light. The photoelectrochemical property of the MgFe{sub 2}O{sub 4} was studied by measuring their photocurrentpotential behavior in 1 M NaOH electrolyte under AM 1.5100 mW cm{sup ?2} illumination. - Graphical abstract: Highly efficient magnetically separable MgFe{sub 2}O{sub 4} photocatalyst for organic based impurities decomposition as well as for the production of H{sub 2} gas was synthesized and characterized successfully (a) MgFe{sub 2}O{sub 4} photocatalyst in polluted water, (b) The photocatalyst (MgFe{sub 2}O{sub 4}) is being attracted toward magnetic field for separation, (c) Hysteresis loop of MgFe{sub 2}O{sub 4} showing magnetic behavior. Highlights: ? New photocatalyst working in the visible range have been synthesized by facile cheap route. ? MgFe{sub 2}O{sub 4} photocatalyst showed well defined magnetically separable behavior. ? Excellent water splitting characteristics to produce H{sub 2} was observed under visible light irradiation.

  16. Separating spatial and temporal variations in auroral electric and magnetic fields by Cluster multipoint measurements

    Directory of Open Access Journals (Sweden)

    T. Karlsson

    2004-07-01

    Full Text Available Cluster multipoint measurements of the electric and magnetic fields from a crossing of auroral field lines at an altitude of 4RE are used to show that it is possible to resolve the ambiguity of temporal versus spatial variations in the fields. We show that the largest electric fields (of the order of 300mV/m when mapped down to the ionosphere are of a quasi-static nature, unipolar, associated with upward electron beams, stable on a time scale of at least half a minute, and located in two regions of downward current. We conclude that they are the high-altitude analogues of the intense return current/black auroral electric field structures observed at lower altitudes by Freja and FAST. In between these structures there are temporal fluctuations, which are shown to likely be downward travelling Alfvn waves. The periods of these waves are 20-40s, which is not consistent with periods associated with either the Alfvnic ionospheric resonator, typical field line resonances or substorm onset related Pi2 oscillations. The multipoint measurements enable us to estimate a lower limit to the perpendicular wavelength of the Alfvn waves to be of the order of 120km, which suggests that the perpendicular wavelength is similar to the dimension of the region between the two quasi-static structures. This might indicate that the Alfvn waves are ducted within a wave guide, where the quasi-static structures are associated with the gradients making up this waveguide.

  17. Evidence for Two Separate but Interlaced Components of the Chromospheric Magnetic Field

    Science.gov (United States)

    Muglach, K.; Reardon, K. P.; Wang, Y.-M.; Warren, H. P.

    2012-01-01

    Chromospheric fibrils are generally thought to trace out horizontal magnetic fields that fan out from flux concentrations in the photosphere. A high-resolution (0.2") image taken in the core of the Ca IJ854.2 nm line shows the dark fibrils within an active region remnant as fine, loop-like features that are aligned parallel to each other and have lengths on the order of a supergranular diameter (approx.30 Mm). Comparison with a line-of-sight magnetogram confirms that the fibrils are centered above intranetwork areas, with one end rooted just inside the neighboring plage or strong unipolar network but the other endpoint less clearly defined. Focusing on a particular arcade-like structure lying entirely on one side of a filament channel (large-scale polarity inversion), we find that the total amount of positive-polarity flux underlying this "fibril arcade' is 50 times greater than the total amount of negative-polarity flux. Thus, if the fibrils represent closed loops, they must consist of very weak fields (in terms of flux density), which are interpenetrated by a more vertical field that contains most of the flux. This surprising result suggests that the fibrils in unipolar regions connect the network to the nearby intranetwork flux, while the bulk of the network flux is diverted upward into the corona and connects to remote regions of the opposite polarity. We conclude that the chromospheric field near the edge of the network has an interlaced structure resembling that in sunspot penumbrae, with the fibrils representing the low-lying horizontal flux that remains trapped within the highly nonpotential chromospheric layer.

  18. Magnetic-optical nanohybrids for targeted detection, separation, and photothermal ablation of drug-resistant pathogens.

    Science.gov (United States)

    Ondera, Thomas J; Hamme, Ashton T

    2015-12-01

    A rapid, sensitive and quantitative immunoassay for the targeted detection and decontamination of E. coli based on Fe3O4 magnetic nanoparticles (MNPs) and plasmonic popcorn-shaped gold nanostructure attached single-walled carbon nanotubes (AuNP@SWCNT) is presented. The MNPs were synthesized as the support for a monoclonal antibody (mAb@MNP). E. coli (49979) was captured and rapidly preconcentrated from the sample with the mAb@MNP, followed by binding with Raman-tagged concanavalin A-AuNP@SWCNTs (Con A-AuNP@SWCNTs) as detector nanoprobes. A Raman tag 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB) generated a Raman signal upon 670 nm laser excitation enabling the detection and quantification of E. coli concentration with a limit of detection of 10(2) CFU mL(-1) and a linear logarithmic response range of 1.0 10(2) to 1.0 10(7) CFU mL(-1). The mAb@MNP could remove more than 98% of E. coli (initial concentration of 1.3 10(4) CFU mL(-1)) from water. The potential of the immunoassay to detect E. coli bacteria in real water samples was investigated and the results were compared with the experimental results from the classical count method. There was no statistically significant difference between the two methods (p > 0.05). Furthermore, the MNP/AuNP@SWCNT hybrid system exhibits an enhanced photothermal killing effect. The sandwich-like immunoassay possesses potential for rapid bioanalysis and the simultaneous biosensing of multiple pathogenic agents. PMID:26469636

  19. A flexible lab-on-a-chip for the synthesis and magnetic separation of magnetite decorated with gold nanoparticles.

    Science.gov (United States)

    Cabrera, Flvio C; Melo, Antonio F A A; de Souza, Joo C P; Job, Aldo E; Crespilho, Frank N

    2015-04-21

    Magnetite decorated with gold nanoparticles (Fe3O4-AuNPs) is a ferrimagnetic material with unprecedented applications in immunosensors, as a contrast agent for imaging diagnosis, and for the photothermal ablation of tumor cells. Here, we show the preparation of controlled amounts of Fe3O4-AuNPs without organic solvents, surfactants, or heat treatment. For this, we have developed a customized natural-rubber-based microfluidic device (NRMD) as a flexible lab-on-a-chip for the decoration of Fe3O4 with AuNPs. With a novel NRMD configuration, monodisperse Fe3O4-NPs (? = 10 nm) decorated with AuNPs (? = 4 nm) were readily obtained. The AuNPs were homogenous in terms of their size and their distribution on the Fe3O4-NP surfaces. Furthermore, the lab-on-a-chip was projected with an internal system for magnetic separation, an innovation in terms of aqueous/carrier phase separation. Finally, the nanomaterials produced with this NRMD are free of organic solvents and surfactants, allowing them to be used directly for medical applications. PMID:25723569

  20. Magnetic source separation in the outer core. Introducing the SCOR-field

    International Nuclear Information System (INIS)

    Complete text of publication follows. We present evidence that the primary source of Earth's axial dipole (AD) is physically distinct from sources responsible for the rest of the geomagnetic field. Support for this claim comes from correlations between the structure of the historic non-axial dipole (NAD) field and transitional paleomagnetic behavior recorded in lavas during the early Brunhes Chron. 40Ar/39Ar age determinations of lavas from West Eifel, Germany, indicate the recording of five excursions spanning ?200 kyr, including the Big Lost Event (?580 ka). Transitional lavas from Tahiti also record the Big Lost as well as the Matuyama-Brunhes reversal. Virtual geomagnetic poles (VGPs) recorded at West Eifel are spread across Eurasia, while those recorded on Tahiti during the two events are associated with the same tightly clustered location west of Australia - the site of the most intense NAD flux feature since direct field measurements started some 400 years ago. The differing locations and amounts of spread of transitional VGPs match - at both sites - virtual poles determined for the historic NAD-field. We contend that (1) the field generated by deep convective columns near the tangent cylinder is the primary source for the AD; and (2) the field arising from flux concentrations held and controlled by lower mantle conditions is the primary source for the NAD. Since there most certainly is a small contribution to the AD term (g10) associated with mantle-held sources, we define this field as the Shallow-Core-Generated (SCOR) field. Paleomagnetic data from Tahiti and Australia strongly suggest that the Australasian flux feature is long-lived, regionally dominating the field when the strength of the main AD had significantly weakened or vanished. We argue that recurrence of transitional VGPs observed over geologic time indicates that (1) the entire field does not reverse as a single unit, and (2) field sources exist in the core that are sufficiently separated to be in 'poor communication.' It follows that subsequent work on spherical harmonic-based field descriptions may now incorporate an understanding of a dichotomy of spatial-temporal dynamo processes.

  1. Synthesis of magnetic molecularly imprinted polymers for the selective separation and determination of metronidazole in cosmetic samples.

    Science.gov (United States)

    Liu, Min; Li, Xiao-Yan; Li, Jun-Jie; Su, Xiao-Meng; Wu, Zong-Yuan; Li, Peng-Fei; Lei, Fu-Hou; Tan, Xue-Cai; Shi, Zhan-Wang

    2015-05-01

    In this study, novel magnetic molecularly imprinted polymers (MMIPs) were developed as a sorbent for solid-phase extraction (SPE) and used for the selective separation of metronidazole (MNZ) in cosmetics; MNZ was detected by high-performance liquid chromatography (HPLC). First, magnetic Fe3O4 nanoparticles (NPs) were prepared by the co-precipitation of Fe(2+)and Fe(3+) ions in an ammonia solution; then oleic acid (OA) was modified onto the surface of Fe3O4NPs. Finally, the MMIP was prepared by aqueous suspension polymerization, involving the copolymerization of Fe3O4NPs@OA with MNZ as the template molecule, methacrylic acid (MAA) as the functional monomer, ethylene glycol maleic rosinate acrylate (EGMRA) as the cross-linking agent, and 2,2-azobisisobutyronitrile (AIBN) as the initiator. The MMIP materials showed high selective adsorption capacity and fast binding kinetics for MNZ; the maximum adsorption amount of the MMIP to MNZ was 46.7 mg/g. The assay showed a linear range from 0.1 to 20.0 ?g/mL for MNZ with the correlation coefficient 0.999. The relative standard deviations (RSD) of intra- and inter-day ranging from 0.71 to 2.45% and from 1.06 to 5.20% were obtained. The MMIP can be applied to the enrichment and determination of MNZ in cosmetic products with the recoveries of spiked toner, powder, and cream cosmetic samples ranging from 90.6 to 104.2, 84.1 to 91.4, and 90.3 to 100.4%, respectively, and the RSD was <3.54%. PMID:25749799

  2. ZnO nanostructured film deposition using the separated pulsed laser deposition (SPLD) assisted by electric and magnetic drift motion

    International Nuclear Information System (INIS)

    We have developed the separated pulsed laser deposition (SPLD) technique to prepare high quality ZnO based films exhibiting uniform and droplet-free properties. This SPLD consists of an ablation chamber and a deposition chamber which can be independently evacuated under different ambient gases. The gas species and the pressures in both chambers can be arbitrarily chosen for the specific deposition such as nanostructured films and nanoparticles. The ablation chamber is a stainless steel globe and the deposition chamber is a quartz tube connected to a metallic conic wall with an orifice. We used a KrF excimer laser with ? = 248 nm and 25 ns pulse duration. The different gas conditions in two chambers allow us to realize optimal control of the plasma plume, the gas phase reaction and the film growth by applying the bias voltage between the conic wall and the substrate under the magnetic field. We can expect that at appropriate pressures the electric and magnetic field motion (E x B azimuthal drift velocity) gives significant influences on film growth. We have deposited ZnO thin films at various pressures of ablation chamber (Pab) and deposition chamber (Pd). The deposition conditions used here were laser fluence of 3 J/cm2, laser shot number of 30,000, Pab of 0.67-2.67 Pa (O2 or Ar), Pd of 0.399-2.67 Pa (O2), and substrate temperature of 400 deg. C. Particle-free and uniform ZnO films were obtained at Pab of 0.67 Pa (Ar) and Pd of 1.33 Pa (O2). The ZnO film showed high preferential orientation of (002) plane, optical band gap of 2.7 eV, grain size of 42 nm and surface roughness of 1.2 nm

  3. Magnetic, durable, and superhydrophobic polyurethane@Fe3O4@SiO2@fluoropolymer sponges for selective oil absorption and oil/water separation.

    Science.gov (United States)

    Wu, Lei; Li, Lingxiao; Li, Bucheng; Zhang, Junping; Wang, Aiqin

    2015-03-01

    Magnetic, durable, and superhydrophobic polyurethane (PU) sponges were fabricated by chemical vapor deposition (CVD) of tetraethoxysilane (TEOS) to bind the Fe3O4 nanoparticles tightly on the sponge and then dip-coating in a fluoropolymer (FP) aqueous solution. The sponges were characterized using scanning electron microscopy and other analytical techniques. The effects of CVD time of TEOS and FP concentration on wettability, mechanical properties, oil absorbency, and oil/water selectivity of the sponges were also investigated. The sponges exhibit fast magnetic responsivity and excellent superhydrophobicity/superoleophilicity (CAwater = 157 and CAoil ? 0). The sponges also show very high efficiency in oil/water separation and could, driven by a magnet, quickly absorb floating oils on the water surface and heavy oils under water. Moreover, the PU@Fe3O4@SiO2@FP sponges could be used as membranes for oil/water separation and for continuous separation of large amounts of oil pollutants from the water surface with the help of a pump. The in turn binding of Fe3O4 nanoparticles, SiO2, and FP can also improve mechanical properties of the PU sponge. The sponges maintain the superhydrophobicity even when they are stretched with 200% strain or compressed with 50% strain. The sponges also show excellent mechanical stability, oil stability, and reusability in terms of superhydrophobicity and oil absorbency. The magnetic, durable, and superhydrophobic PU sponges are very promising materials for practical oil absorption and oil/water separation. PMID:25671386

  4. Ultrasonic-assisted preparation of novel ternary ZnO/AgI/Fe3O4 nanocomposites as magnetically separable visible-light-driven photocatalysts with excellent activity.

    Science.gov (United States)

    Shekofteh-Gohari, Maryam; Habibi-Yangjeh, Aziz

    2016-01-01

    The present work demonstrates preparation of novel ternary ZnO/AgI/Fe3O4 nanocomposites, as magnetically separable visible-light-driven photocatalysts using ultrasonic irradiation method. The XRD, EDX, SEM, TEM, UV-vis DRS, FT-IR, PL, and VSM techniques was applied for characterization of structure, purity, morphology, optical, and magnetic properties of the resultant samples. The superior activity was seen for the nanocomposite with 8 weight ratio of ZnO/AgI to Fe3O4 in degradation of rhodamine B under visible-light irradiation. Photocatalytic activity of this nanocomposite in degradation of rhodamine B, methylene blue, and methyl orange is about 32, 6, and 5-fold higher than that of the ZnO/Fe3O4 nanocomposite. The highly enhanced activity of the ternary magnetic photocatalyst was mainly attributed to more visible-light absorption ability and efficiently separation of the charge carriers. Furthermore, it was revealed that the ultrasonic irradiation time and calcination temperature affect largely on the photocatalytic activity. Finally, the magnetic photocatalyst was successfully separated from the treated solution using external magnetic field. PMID:26397921

  5. Fenton-like degradation of Methylene Blue using paper mill sludge-derived magnetically separable heterogeneous catalyst: Characterization and mechanism.

    Science.gov (United States)

    Zhou, Guoqiang; Chen, Ziwen; Fang, Fei; He, Yuefeng; Sun, Haili; Shi, Huixiang

    2015-09-01

    For the paper industry, the disposal and management of the yielded sludge are a considerable challenge. In our work, the paper mill sludge-derived magnetically separable heterogeneous catalyst (PMS-Fe-380) was prepared easily through a facile synthesis method. The morphology and structure of PMS-Fe-380 were fully characterized by means of X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and Brunauer-Emmet-Teller analysis. The catalytic activity of PMS-Fe-380 was evaluated by degradation of Methylene Blue (MB). The reusability and stability of PMS-Fe-380 were evaluated in five repeated runs, which suggested that PMS-Fe-380 manifested excellent stability of catalytic activity. Moreover, leaching tests indicated that the leached iron is negligible (<0.5mg/L). This study provides an alternative environmentally friendly reuse method for paper mill sludge and a novel catalyst PMS-Fe-380 that can be considered as a promising heterogeneous Fenton-like catalyst. PMID:26354688

  6. Magnetically Separable Fe3O4/AgBr Hybrid Materials: Highly Efficient Photocatalytic Activity and Good Stability

    Science.gov (United States)

    Cao, Yuhui; Li, Chen; Li, Junli; Li, Qiuye; Yang, Jianjun

    2015-06-01

    Magnetically separable Fe3O4/AgBr hybrid materials with highly efficient photocatalytic activity were prepared by the precipitation method. All of them exhibited much higher photocatalytic activity than the pure AgBr in photodegradation of methyl orange (MO) under visible light irradiation. When the loading amount of Fe3O4 was 0.5 %, the hybrid materials displayed the highest photocatalytic activity, and the degradation yield of MO reached 85 % within 12 min. Silver halide often suffers serious photo-corrosion, while the stability of the Fe3O4/AgBr hybrid materials improved apparently than the pure AgBr. Furthermore, depositing Fe3O4 onto the surface of AgBr could facilitate the electron transfer and thereby leading to the elevated photocatalytic activity. The morphology, phase structure, and optical properties of the composites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-visible diffuse reflectance spectra (UV-vis DRS), and photoluminescence (PL) techniques.

  7. Magnetically Separable Fe3O 4/AgBr Hybrid Materials: Highly Efficient Photocatalytic Activity and Good Stability.

    Science.gov (United States)

    Cao, Yuhui; Li, Chen; Li, Junli; Li, Qiuye; Yang, Jianjun

    2015-12-01

    Magnetically separable Fe3O4/AgBr hybrid materials with highly efficient photocatalytic activity were prepared by the precipitation method. All of them exhibited much higher photocatalytic activity than the pure AgBr in photodegradation of methyl orange (MO) under visible light irradiation. When the loading amount of Fe3O4 was 0.5%, the hybrid materials displayed the highest photocatalytic activity, and the degradation yield of MO reached 85% within 12min. Silver halide often suffers serious photo-corrosion, while the stability of the Fe3O4/AgBr hybrid materials improved apparently than the pure AgBr. Furthermore, depositing Fe3O4 onto the surface of AgBr could facilitate the electron transfer and thereby leading to the elevated photocatalytic activity. The morphology, phase structure, and optical properties of the composites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-visible diffuse reflectance spectra (UV-vis DRS), and photoluminescence (PL) techniques. PMID:26058513

  8. Magnetically separable hybrid CdS-TiO{sub 2}-Fe{sub 3}O{sub 4} nanomaterial: Enhanced photocatalystic activity under UV and visible irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Bian, Xiaofang; Hong, Kunquan, E-mail: hongkq@gmail.com; Liu, Liqing; Xu, Mingxiang, E-mail: mxxu@seu.edu.cn

    2013-09-01

    Magnetically separable photocatalyst of TiO{sub 2}-CdS-Fe{sub 3}O{sub 4}@SiO{sub 2} nanocomposite was successfully prepared through a microwave heating method. The products exhibit enhanced photocatalystic activity which is more efficient than that of pure CdS and Degussa P25 TiO{sub 2} toward the degradation of RhB under both UV and visible irradiation. This is attributed to the charge separation and transformation from CdS to TiO{sub 2}. The hysteresis loop of TiO{sub 2}-CdS-Fe{sub 3}O{sub 4}@SiO{sub 2} nanocomposite indicates an excellent magnetic property with the saturated magnetization of 9 emu/g. We also show the fast magnetic separation behaviour of the TiO{sub 2}-CdS-Fe{sub 3}O{sub 4}@SiO{sub 2} nanocomposite to remove and recycle the photocatalyst from the solution. These indicate TiO{sub 2}-CdS-Fe{sub 3}O{sub 4}@SiO{sub 2} nanocomposite is an effective and convenient recyclable photocatalyst.

  9. Magnetically separable hybrid CdS-TiO2-Fe3O4 nanomaterial: Enhanced photocatalystic activity under UV and visible irradiation

    International Nuclear Information System (INIS)

    Magnetically separable photocatalyst of TiO2-CdS-Fe3O4@SiO2 nanocomposite was successfully prepared through a microwave heating method. The products exhibit enhanced photocatalystic activity which is more efficient than that of pure CdS and Degussa P25 TiO2 toward the degradation of RhB under both UV and visible irradiation. This is attributed to the charge separation and transformation from CdS to TiO2. The hysteresis loop of TiO2-CdS-Fe3O4@SiO2 nanocomposite indicates an excellent magnetic property with the saturated magnetization of 9 emu/g. We also show the fast magnetic separation behaviour of the TiO2-CdS-Fe3O4@SiO2 nanocomposite to remove and recycle the photocatalyst from the solution. These indicate TiO2-CdS-Fe3O4@SiO2 nanocomposite is an effective and convenient recyclable photocatalyst.

  10. Enrichment of Rare Earth and Niobium from a REE-Nb-Fe Associated Ore via Reductive Roasting Followed by Magnetic Separation

    Science.gov (United States)

    Liu, Mudan; You, Zhixiong; Peng, Zhiwei; Li, Xiang; Li, Guanghui

    2016-02-01

    REE-Nb-Fe ore is a typical refractory resource rich in valuable elements. In this article, coal-based reductive roasting followed by magnetic separation is proposed to recover rare earth element (REE), niobium (Nb), and powdered metallic iron (Fe) concentrate from a REE-Nb-Fe raw concentrate containing 31.9% total iron grade (TFe), 3.2% rare earth oxides (REO), and 2.9% Nb2O5. Sodium sulfate is employed to enhance the reduction of iron oxide and to facilitate the growth of metallic iron grains. A magnetic fraction with TFe of 89.3%, iron metallization of 95.8% and iron recovery of 91.5% is obtained by magnetic separation after the raw concentrate is reduced to 1100C for 120 min in the presence of 15 wt.% sodium sulfate. The contents of rare earth and niobium in the nonmagnetic fraction are enriched to 5.4% (REO) and 4.6% (Nb2O5) with recoveries of 96.1% and 95.8%, respectively. The TFe in the nonmagnetic fraction obtained after the separation is decreased to 4.8% accordingly. The reactions between sodium sulfate and SiO2/Al2O3 enhance the reduction by destroying the mineral structure. The separation of iron from rare earth and niobium is highly improved as metallic iron grains grow markedly when roasted in the presence of sodium sulfate.

  11. Weak cation magnetic separation technology and MALDI-TOF-MS in screening serum protein markers in primary type I osteoporosis.

    Science.gov (United States)

    Shi, X L; Li, C W; Liang, B C; He, K H; Li, X Y

    2015-01-01

    We investigated weak cation magnetic separation technology and matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) in screening serum protein markers of primary type I osteoporosis. We selected 16 postmenopausal women with osteoporosis and nine postmenopausal women as controls to find a new method for screening biomarkers and establishing a diagnostic model for primary type I osteoporosis. Serum samples were obtained from controls and patients. Serum protein was extracted with the WCX protein chip system; protein fingerprints were examined using MALDI-TOF-MS. The preprocessed and model construction data were handled by the ProteinChip system. The diagnostic models were established using a genetic arithmetic model combined with a support vector machine (SVM). The SVM model with the highest Youden index was selected. Combinations with the highest accuracy in distinguishing different groups of data were selected as potential biomarkers. From the two groups of serum proteins, 123 cumulative MS protein peaks were selected. Significant intensity differences in the protein peaks of 16 postmenopausal women with osteoporosis were screened. The difference in Youden index between the four groups of protein peaks showed that the highest peaks had mass-to-charge ratios of 8909.047, 8690.658, 13745.48, and 15114.52. A diagnosis model was established with these four markers as the candidates, and the model specificity and sensitivity were found to be 100%. Two groups of specimens in the SVM results on the scatterplot were distinguishable. We established a diagnosis model, and provided a new serological method for screening and diagnosis of osteoporosis with high sensitivity and specificity. PMID:26634492

  12. Ferrimagnetism and magnetic phase separation in Nd{sub 1?x}Y{sub x}MnO{sub 3} studied by magnetization and high frequency electron paramagnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Nair, Harikrishnan S., E-mail: krishnair1@gmail.com [Department of Physics, Indian Institute of Science, Bangalore 560012 (India); Yadav, Ruchika [Department of Physics, Indian Institute of Science, Bangalore 560012 (India); Adiga, Shilpa [Jlich Center for Neutron Sciences 2/Peter Grnberg Institute 4, Forschungszentrum Jlich GmbH, 52425 Jlich (Germany); Rao, S.S. [Materials Science Division, Army Research Office, Research Triangle Park, North Carolina 27709 (United States); Department of Material Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Tol, Johan van [National High Magnetic Field Laboratory, Centre for Interdisciplinary Magnetic Resonance, Florida State University,1800 E. Paul Dirac Drive, Tallahassee, Florida 32310 (United States); Elizabeth, Suja [Department of Physics, Indian Institute of Science, Bangalore 560012 (India)

    2015-01-01

    Ferrimagnetism and metamagnetic features tunable by composition are observed in the magnetic response of Nd{sub 1?x}Y{sub x}MnO{sub 3}, for x=0.10.5. For all values of x in the series, the compound crystallizes in orthorhombic Pbnm space group similar to NdMnO{sub 3}. Magnetization studies reveal a phase transition of the Mn-sublattice below T{sub N}{sup Mn}?80K for all compositions, which, decreases up on diluting the Nd-site with Yttrium. For x=0.35, ferrimagnetism is observed. At 5 K, metamagnetic transition is observed for all compositions x<0.4. The evolution of magnetic ground states and appearance of ferrimagnetism in Nd{sub 1?x}Y{sub x}MnO{sub 3} can be accounted for by invoking the scenario of magnetic phase separation. The high frequency electron paramagnetic resonance measurements on x=0.4 sample, which is close to the critical composition for phase separation, revealed complex temperature dependent lineshapes clearly supporting the assumption of magnetic phase separation.

  13. Separation of species of a binary fluid mixture confined between two concentric rotating circular cylinders in presence of a strong radial magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, B.R. [Dibrugarh University, Department of Mathematics, Dibrugarh, Assam (India); Singh, R.N. [Marwari Hindi High School, Dibrugarh (India)

    2010-08-15

    The effect of a radial magnetic field on separation of a binary mixture of incompressible viscous thermally and electrically conducting fluids confined between two concentric rotating circular cylinders with different angular velocity is examined. The equations governing the motion, temperature and concentration in cylindrical polar coordinate are solved analytically. The solution obtained in closed form for concentration distribution is plotted against the radial distances from the surface of the inner circular cylinder for various values of non-dimensional parameters. It is found that the non-dimensional parameters viz. the Hartmann number, thermal diffusion number, baro diffusion number, rotational Reynolds number, the product of Prandtl number and Eckert number, magnetic Prandtl number and the ratio of the angular velocities of inner and outer cylinders affects the species separation of rarer and lighter component significantly. The problem discussed here derives its application in the basic fluid dynamics separation processes to separate the rarer component of the different isotopes of heavier molecules where electromagnetic method of separation does not work. (orig.)

  14. Isolation of prostate cancer cell subpopulations of functional interest by use of an on-chip magnetic bead-based cell separator

    International Nuclear Information System (INIS)

    This work presents the design, fabrication and characterization of a modular magnetic bead-based cell separation device developed for the sequential sorting of a heterogeneous prostate cancer (CaP) cell population. The chief aim is cell sorting carried out on the basis of surface marker expression, serially selecting cellular subpopulations for capture by the use of antibody-coated magnetic beads. The markers of interest, prostate specific membrane antigen (PSMA) and CD10 were selected for their relevance to ongoing CaP development research. The separation device was fabricated out of plastic, by the use of cyclic olefin copolymer (COC) injection molding, nickeliron electroplating and thermoplastic fusion bonding. Effective depletion and enrichment of cell subsets based on multiple surface markers was achieved. Various flow rates and incubation times were tested for optimizing the sorting procedure

  15. Isolation of prostate cancer cell subpopulations of functional interest by use of an on-chip magnetic bead-based cell separator

    Science.gov (United States)

    Estes, Matthew D.; Ouyang, Bin; Ho, Shuk-mei; Ahn, Chong H.

    2009-09-01

    This work presents the design, fabrication and characterization of a modular magnetic bead-based cell separation device developed for the sequential sorting of a heterogeneous prostate cancer (CaP) cell population. The chief aim is cell sorting carried out on the basis of surface marker expression, serially selecting cellular subpopulations for capture by the use of antibody-coated magnetic beads. The markers of interest, prostate specific membrane antigen (PSMA) and CD10 were selected for their relevance to ongoing CaP development research. The separation device was fabricated out of plastic, by the use of cyclic olefin copolymer (COC) injection molding, nickel-iron electroplating and thermoplastic fusion bonding. Effective depletion and enrichment of cell subsets based on multiple surface markers was achieved. Various flow rates and incubation times were tested for optimizing the sorting procedure.

  16. Cluster glass magnetism in the phase-separated Nd{sub 2/3}Ca{sub 1/3}MnO{sub 3} perovskite

    Energy Technology Data Exchange (ETDEWEB)

    Fertman, Elena, E-mail: fertman@ilt.kharkov.ua [B. Verkin Institute for Low Temperature Physics and Engineering NASU, 47 Lenin Ave., Kharkov 61103 (Ukraine); Dolya, Sergiy; Desnenko, Vladimir; Beznosov, Anatoly [B. Verkin Institute for Low Temperature Physics and Engineering NASU, 47 Lenin Ave., Kharkov 61103 (Ukraine); Kajnakova, Marcela; Feher, Alexander [P. J. Safarik University in Kosice, Faculty of Science, Park Angelinum 9, 04154 Kosice (Slovakia)

    2012-09-15

    A detailed study of the low-temperature magnetic state and the relaxation in the phase-separated colossal magnetoresistance Nd{sub 2/3}Ca{sub 1/3}MnO{sub 3} perovskite has been carried out. Clear experimental evidence of the cluster-glass magnetic behavior of this compound has been revealed. Well defined maxima in the in-phase linear ac susceptibility {chi} Prime (T) were observed, indicative of the magnetic glass transition at T{sub g}{approx}60 K. Strongly divergent zero-field-cooled and field-cooled static magnetizations and frequency dependent ac susceptibility are evident of the glassy-like magnetic state of the compound at low temperatures. The frequency dependence of the cusp temperature T{sub max} of the {chi} Prime (T) susceptibility was found to follow the critical slowing down mechanism. The Cole-Cole analysis of the dynamic susceptibility at low temperature has shown extremely broad distribution of relaxation times, indicating that spins are frozen at 'macroscopic' time scale. Slow relaxation in the zero-field-cooled magnetization has been experimentally revealed. The obtained results do not agree with a canonical spin-glass state and indicate a cluster glass magnetic state of the compound below T{sub g}, associated with its antiferromagnetic-ferromagnetic nano-phase segregated state. It was found that the relaxation mechanisms below the cluster glass freezing temperature T{sub g} and above it are strongly different. Magnetic field up to about {mu}{sub 0}H{approx}0.4 T suppresses the glassy magnetic state of the compound. - Highlights: Black-Right-Pointing-Pointer Cluster-glass magnetic state of Nd{sub 2/3}Ca{sub 1/3}MnO{sub 3} below T{sub g}{approx}60 K has been revealed. Black-Right-Pointing-Pointer Magnetic fields up to about {mu}{sub 0}H{approx}0.4 T suppress the glassy magnetic state. Black-Right-Pointing-Pointer Extremely broad distribution of relaxation times has been found below T{sub g}. Black-Right-Pointing-Pointer The relaxation mechanisms below and above T{sub g} are found to be strongly different. Black-Right-Pointing-Pointer Cluster-glass magnetic behavior of Nd{sub 2/3}Ca{sub 1/3}MnO{sub 3} is associated with its phase segregated state.

  17. Improved accuracy of U-Pb zircon dating by selection of more concordant fractions using a high gradient magnetic separation technique

    International Nuclear Information System (INIS)

    A loop of soft iron wire or a paper clip or a ferromagnetic grid mounted between the poles of an electromagnet picks up and allows further magnetic separation of zircons previously found to be non-magnetic on a Frantz Isodynamic Separator. Tests on previously analysed samples indicate that most such zircons that are fairly discordant (say approximately 10%) can be picked up and isolated from associated grains that are more concordant. Tests on new samples indicate that even when most grains can be picked up the last few percent of the sample contain less uranium, and are more concordant than the bulk sample. The degree of discordance is the dominant factor affecting the uncertainty of U-Pb zircon ages both because of the error amplification in projections, and because the assumption of a simple two-stage system may not be valid. Only by eliminating or reducing discordance can errors approaching the uncertainty in a single analysis, say +- 2 m.y. for 2700 m.y. rocks, be achieved. Rutile normally concentrated with zircon as non-magnetic has been successfully removed from a small amount of low uranium zircon, using the high intensity separation technique. (author)

  18. Improved accuracy of U-Pb zircon dating by selection of more concordant fractions using a high gradient magnetic separation technique

    International Nuclear Information System (INIS)

    A loop of soft iron wire or a paper clip or a ferromagnetic grid mounted between the poles of an electromagnet picks up and allows further magnetic separation of zircons previously found to be non-magnetic on a Frantz Isodynamic Separator. Tests on previously analysed samples indicate that most such zircons that are fairly discordant (say approximately 10%) can be picked up and isolated from associated grains that are more concordant. Tests on new samples indicate that even when most grains can be picked up the last few percent of the sample contain less uranium, and are more concordant than the bulk sample. The degree of discordance is the dominant factor affecting the uncertainty of U-Pb zircon ages both because of the error amplification in projections, and because the assumption of a simple two-stage system may not be valid. Only by eliminating or reducing discordance can errors approaching the uncertainty in a single analysis, say +-2m.y. for 2700m.y. rocks, be achieved. Rutile normally concentrated with zircon as non-magnetic has been successfully removed from a small amount of low uranium zircon, using the high intensity separation technique. (author)

  19. Magnetically separable ternary g-C3N4/Fe3O4/BiOI nanocomposites: Novel visible-light-driven photocatalysts based on graphitic carbon nitride.

    Science.gov (United States)

    Mousavi, Mitra; Habibi-Yangjeh, Aziz

    2016-03-01

    The present work demonstrates preparation of magnetically separable ternary g-C3N4/Fe3O4/BiOI nanocomposites as novel visible-light-driven photocatalysts. The resultant samples were characterized using XRD, EDX, SEM, TEM, UV-Vis DRS, FT-IR, PL, BET, and VSM techniques. The results revealed that weight percent of BiOI has considerable effect on photodegradation of rhodamine B under visible-light irradiation. Among the prepared samples, the g-C3N4/Fe3O4/BiOI (20%) nanocomposite has the best photocatalytic activity. The activity of this nanocomposite is about 10, 22, and 21-fold higher than that of the g-C3N4 sample in degradation of rhodamine B, methylene blue, and methyl orange under the visible-light irradiation. The excellent activity of the magnetic nanocomposite was attributed to more harvesting of the visible-light irradiation and efficiently separation of the electron-hole pairs. More importantly, the nanocomposite was magnetically separated after five successive cycles. PMID:26669494

  20. Combination of dynamic magnetophoretic separation and stationary magnetic trap for highly sensitive and selective detection of Salmonella typhimurium in complex matrix.

    Science.gov (United States)

    Guo, Pei-Lin; Tang, Man; Hong, Shao-Li; Yu, Xu; Pang, Dai-Wen; Zhang, Zhi-Ling

    2015-12-15

    Foodborne illnesses have always been a serious problem that threats public health, so it is necessary to develop a method that can detect the pathogens rapidly and sensitively. In this study, we designed a magnetic controlled microfluidic device which integrated the dynamic magnetophoretic separation and stationary magnetic trap together for sensitive and selective detection of Salmonella typhimurium (S. typhimurium). Coupled with immunomagnetic nanospheres (IMNs), this device could separate and enrich the target pathogens and realize the sensitive detection of target pathogens on chip. Based on the principle of sandwich immunoassays, the trapped target pathogens identified by streptavidin modified QDs (SA-QDs) were detected under an inverted fluorescence microscopy. A linear range was exhibited at the concentration from 1.010(4) to 1.010(6) colony-forming units/mL (CFU/mL), the limit of detection (LOD) was as low as 5.410(3) CFU/mL in milk (considering the sample volume, the absolute detection limit corresponded to 540C FU). Compared with the device with stationary magnetic trap alone, the integrated device enhanced anti-interference ability and increased detection sensitivity through dynamic magnetophoretic separation, and made the detection in complex samples more accurate. In addition, it had excellent specificity and good reproducibility. The developed system provides a rapid, sensitive and accurate approach to detect pathogens in practice samples. PMID:26201979

  1. A novel method for isolating specific endocytic vesicles using very fine ferrite particles coated with biological ligands and the high-gradient magnetic separation technique.

    Science.gov (United States)

    Sato, S B; Sako, Y; Yamashina, S; Ohnishi, S

    1986-12-01

    We have developed a novel method for isolating specific endocytic vesicles using magnetic ligands and high-gradient magnetic separation. Ligands were prepared by coating extremely fine ferrite particles (10-20 nm) with bovine serum albumin and then conjugating asialoglycopeptides. These ligands were introduced into rat liver by perfusion at 16 or 37 degrees C, or by injection through the tail vein. The ligand particles were observed as electron-dense small grains in membrane-bound vesicles in Kupffer as well as parenchymal cells by electron microscopy. Livers were taken out, homogenized and lightly centrifuged. The supernatant was pumped into a separator glass tube filled with very fine ferritic stainless steel fibers and placed in a magnetic field of 0.9-2 T. Vesicles containing ferrite particles were collected with a high efficiency (ca. 70% of endocytosed magnetic ligands). About 70% of uptake appeared to be mediated by the asialoglycoprotein receptors. The captured vesicles were practically free from marker enzymes for plasma membranes, endoplasmic reticulum, and Golgi apparatus. Lysosomal enzyme activity of the vesicles increased with the time of perfusion at 37 degrees C but not at 16 degrees C. Protein composition of the captured vesicles was analyzed by one- and two-dimensional gel electrophoresis. The composition changed characteristically with time on perfusion at 16 and 37 degrees C. The present method provides a powerful tool to collect prelysosomal endocytic vesicles containing specific ligands and lysosomes fused with these specific endocytic vesicles. PMID:3571183

  2. Preparations and photocatalytic degradation of methyl orange in water on magnetically separable Bi12TiO20 supported on nickel ferrite

    Directory of Open Access Journals (Sweden)

    Shihong Xu, Wenfeng Shangguan, Jian Yuan, Jianwei Shi and Mingxia Chen

    2007-01-01

    Full Text Available A magnetically separable photocatalyst Bi12TiO20/SiO2/NiFe2O4 (BSN with a typical ferromagnetic hysteresis was prepared by a simple process: the magnetic 200 wt% SiO2/NiFe2O4 (SN dispersion prepared by a liquid catalytic phase transformation method and the visible-light-active photocatalyst Bi12TiO20 prepared by a simple coprecipitation processing were mixed, sonificated, dried, and calcined at 550 C. The prepared photocatalyst showed high photocatalytic activity for the degradation of methyl orange in water under UV irradiation and visible-light irradiation (?>400 nm, and it was easy to be separated from a slurry-type photoreactor under the application of an external magnetic field, being one of promising photocatalysts for wastewater treatment. Transmission electron microscope (TEM and X-ray diffractometer (XRD were used to characterize the structure of the photocatalyst, indicating that the magnetic SN particles adhered to the surface of the Bi12TiO20 congeries. SiO2 layer round the surface of NiFe2O4 nanoparticles prevented effectively the injection of charges from TiO2 particles to NiFe2O4, which gave rise to the increase in photocatalytic activity.

  3. Novel Phase Separation and Magnetic Volume Tuning in Underdoped NaFe1-xCoxAs (x 0.01)

    Science.gov (United States)

    Ma, Long; Dai, J.; Lu, X. R.; Tan, Guotai; Song, Yu; Dai, Pengcheng; Zhang, C. L.; Normand, B.; Yu, Weiqiang

    2013-03-01

    NaFeAs is a quasi-2D pnictide parent compound with a weak magnetic moment and separate structural and antiferromagnetic transitions. Because Co doping leads to a superconductor with Tc ~= 20 K at a very low optimal doping of x = 0 . 02 , NaFe1-xCoxAs is uniquely suited to sensitive studies of the cohabitation and competition between magnetism and superconductivity. Using NMR as a local probe of both antiferromagnetic order and superconductivity, we have compared Knight shifts and relaxation rates on the Na, As, and Co nuclei. Above Tc, we find weak doping inhomogeneity, in the form of residual paramagnetic regions with differing TN values, and a strongly field-controlled magnetic volume. Below Tc, we observe a strong competition between antiferromagnetism and superconductivity, in which the temperature is the dominant control parameter, suppressing the magnetic volume fraction very significantly in favor of the superconducting one, while the external field suppresses Tc. Our results suggest both a microscale phase separation in real space and in reciprocal space a competition between two order parameters requiring the same electrons on the quasi-2D Fermi surface.

  4. Observation of dynamical spin-dependent electron interactions and screening in magnetic transitions via core-level multiplet-energy separations

    Energy Technology Data Exchange (ETDEWEB)

    Tober, Eric D.; Palomares, F. Javier; Ynzunza, Ramon X.; Denecke, Reinhard [Department of Physics, University of California Davis, Davis, CA 95616 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Morais, Jonder [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Liesegang, John [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Department of Physics, La Trobe University, Melbourne, VIC 3086 (Australia); Hussain, Zahid [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Shick, Alexander B.; Pickett, Warren E. [Department of Physics, University of California Davis, Davis, CA 95616 (United States); Fadley, Charles S., E-mail: fadley@lbl.gov [Department of Physics, University of California Davis, Davis, CA 95616 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2013-08-15

    Highlights: ? Gd 5s and 4s multiplet splittings of Gd(0001) change during magnetic transitions. ?Atomic multiplet theory and LDA+U calculations partially explain these results. ?Provide a novel probe of dynamical spin-dependent screening/magnetic fluctuations. ? Suggest future experiments in a time-resolved mode, e.g. using free electron lasers. -- Abstract: The magnetic phase transitions for Gd(0 0 0 1) grown on W(1 1 0) a bulk transition at 293 K and a surface transition about 85 K above this are found to influence the energy separation of the Gd 5s and 4s core-photoelectron doublets. The 5s doublet separation ?E{sub 5s} changes over a range of temperatures spanning these transitions, and decreases by a maximum of 60 meV in this region, but then recovers its original value; the 4s doublet shows a smaller change in the reverse direction, which does not recover at high temperature. Some of these effects are semi-quantitatively understood from free-atom multiplet theory and from theoretical calculations based on all-electron LDA+U calculations including 4f electron correlation effects. However, the high-temperature behavior of the data also suggest a dynamical nature to these effects via spin-dependent electron screening that is influenced by magnetic fluctuations. Several avenues for studying such effects in a time-resolved manner in future experiments are discussed.

  5. Magnetic ordering in electronically phase-separated La2-xSrxCuO4+y: Neutron diffraction experiments

    DEFF Research Database (Denmark)

    Udby, Linda; Andersen, Niels Hessel; Chou, F.C.; Christensen, Niels Bech; Emery, S.B.; Lefmann, Kim; Lynn, J.W.; Mohottala, H.E.; Niedermayer, Ch.; Wells, B.O.

    2009-01-01

    We present results of magnetic neutron diffraction experiments on the codoped superoxygenated La2-xSrxCuO4+y (LSCO+O) system with x=0.09. We find that the magnetic phase is long-range ordered incommensurate antiferromagnetic with a Neacuteel temperature T-N coinciding with the superconducting...

  6. In vivo labeling and specific magnetic bead separation of RNA for biofilm characterization and stress-induced gene expression analysis in bacteria.

    Science.gov (United States)

    Stankiewicz, Nikolai; Gold, Andrea; Yksel, Yousra; Berensmeier, Sonja; Schwartz, Thomas

    2009-12-01

    The method of in vivo labeling and separation of bacterial RNA was developed as an approach to elucidating the stress response of natural bacterial populations. This technique is based on the incorporation of digoxigenin-11-uridine-5'-triphosphate (DIG-11-UTP) in the RNA of active bacteria. The digoxigenin fulfills a dual role as a label of de novo synthesized RNA and a target for magnetic bead separation from a total RNA extract. Depending on the growth conditions and the population's composition, the assembly rate of DIG-11-UTP ranged from 1.2% to 12.5% of the total RNA in gram-positive and gram-negative reference bacteria as well as in natural biofilms from drinking water, surface water, and lake sediment. Separation of DIG-RNA from total RNA extracts was performed with a biotinylated anti-digoxigenin antibody and streptavidin-functionalized magnetic particles. The average separation yield from total RNA extracts was about 95% of labeled RNA. The unspecific bindings of non-labeled nucleic acids were smaller than 0.2%, as was evaluated by spiking experiments with an unmarked DNA amplicon. Applicability of the method developed was demonstrated by rRNA-directed PCR-DGGE population analysis of natural biofilms and expression profiling of two stress-induced genes (vanA and rpoS) in reference bacteria. PMID:19837116

  7. Magnetically separable ternary hybrid of ZnFe2O4Fe2O3Bi2WO6 hollow nanospheres with enhanced visible photocatalytic property

    International Nuclear Information System (INIS)

    Highlights: Ternary hybrid ZnFe2O4Fe2O3Bi2WO6 hollow nanospheres were synthesized. Ternary hybrid sample exhibited highest performance than the others. The enhanced activity could be attributed to the cascade electron transfer. The photocatalyst could be separated by magnetic field. - Abstract: Magnetically separable ternary hybrid ZnFe2O4Fe2O3Bi2WO6 hollow nanospheres were designed and synthesized by an effective three-step approach. Specifically, using phenolic formaldehyde microspheres (PFS) as template direct the sequential coating of ?-Fe2O3/ZnFe2O4 layer and subsequent Bi2WO6 layer via impregnating-calcination process. The photocatalytic activity under visible light irradiation is in the order of ZnFe2O4Fe2O3Bi2WO6 > ZnFe2O4Bi2WO6 > Bi2WO6 > ZnFe2O4Fe2O3 > ZnFe2O4. The enhanced activity could be attributed to the cascade electron transfer from ZnFe2O4 to ?-Fe2O3 then to Bi2WO6 through the interfacial potential gradient in the ternary hybrid conduction bands, which facilitate the charge separation and retard the charge pair recombination. Furthermore, the ternary hybrid ZnFe2O4Fe2O3Bi2WO6 hollow nanospheres could be conveniently separated by using an external magnetic field, and be chemically and optically stable after several repetitive tests. The study also provides a general and effective method in the composite hollow nanomaterials with sound heterojunctions that may show a variety of applications

  8. Pre-analysis separation and concentration of actinides in groundwater using a magnetic filtration/sorption method. I. Background and concept

    International Nuclear Information System (INIS)

    A wide variety of iron oxides has been used for the removal of radioactive and toxic metals from aqueous solutions. Natural magnetite and iron ferrite (FeO x Fe2O3) in a batch mode to remove actinides (Pu and Am) from wastewater have been utilized. Compared to the batch process, enhanced capacity for actinide removal was observed using supported magnetite in a column surrounded by an external magnetic field (0.3 tesla). The enhanced magnetite capacity in the column is primarily due to magnetic filtration of colloidal and submicron actinide particles along with some actinide complex and ion exchange sorption mechanisms. The removal of the magnetic field from around the column and use of a regenerating solution will easily remove the actinides loaded on the magnetite. The magnetic field-enhanced column process is under development for a variety of applications. Previous work on using ferrites for water treatment is reviewed and the potential for using the magnetic field-enhanced column process as a pre-analysis separation and concentration method for actinides in groundwater is discussed. (author)

  9. Magnetically separable Fe3O4@SiO2@TiO2-Ag microspheres with well-designed nanostructure and enhanced photocatalytic activity

    International Nuclear Information System (INIS)

    Graphical abstract: An effective route has been developed to synthesize magnetic Fe3O4@SiO2@TiO2-Ag microspheres with well-defined coreshell nanostructure and enhanced photocatalytic activity. -- Highlights: Controllable synthesis of coreshell structured Fe3O4@SiO2@TiO2-Ag magnetic nanocomposite. The unique nanostructure of Fe3O4@SiO2@TiO2-Ag can improve the total photocatalytic performance. An easy magnetically separable and recoverable process. -- Abstract: Major efforts in modern material chemistry are devoted to the design and fabrication of nanostructured systems with tunable physicalchemical properties for advanced catalytic applications. Here, a novel Fe3O4@SiO2@TiO2-Ag nanocomposite has been synthesized and characterized by a series of techniques including SEM, TEM, XRD, XPS as well as magnetization measurement and subsequently tested for the photocatalytic activities. The well-designed nanocomposite exhibits significantly superior activity to that of the commercial Degussa P25 thanks to the suppression of electronhole pairs from recombination by Ag nanoparticles, and can be easily recycled by applying an external magnetic field while maintaining the catalytic activity without significant decrease even after running 10 times. The unique nanostructure makes Fe3O4@SiO2@TiO2-Ag a highly efficient, recoverable, stable, and cost-effective photocatalytic system offering broad opportunities in the field of catalyst synthesis and application

  10. Ternary ZnO/Ag3VO4/Fe3O4 nanocomposites: Novel magnetically separable photocatalyst for efficiently degradation of dye pollutants under visible-light irradiation

    Science.gov (United States)

    Shekofteh-Gohari, Maryam; Habibi-Yangjeh, Aziz

    2015-10-01

    In this work, we successfully prepared a series of novel magnetically separable ZnO/Ag3VO4/Fe3O4 nanocomposites by a facile refluxing method using Fe3O4, zinc nitrate, silver nitrate, ammonium metavanadate, and sodium hydroxide as starting materials without using any post preparation treatments. The microstructure, purity, morphology, spectroscopic, and magnetic properties of the prepared samples were studied using XRD, EDX, SEM, TEM, UV-vis DRS, FT-IR, PL, and VSM techniques. The ZnO/Ag3VO4/Fe3O4 nanocomposite with 8:1 weight ratio of ZnO/Ag3VO4 to Fe3O4 has the superior activity in degradation of rhodamine B under visible-light irradiation. Photocatalytic activity of this nanocomposite is about 11.5-fold higher than that of the ZnO/Fe3O4 nanocomposite. The results showed that the preparation time and calcination temperature significantly affect on the photocatalytic activity. The trapping experiments revealed that superoxide ions and holes have major influence on the degradation reaction. Furthermore, the enhanced activity of the nanocomposite for degradation of two more dye pollutants was confirmed. Finally, the nanocomposite was magnetically separated from the treated solution after four successive cycles.

  11. A novel magnetically separable TiO{sub 2}/CoFe{sub 2}O{sub 4} nanofiber with high photocatalytic activity under UV-vis light

    Energy Technology Data Exchange (ETDEWEB)

    Li, Cong-Ju, E-mail: congjuli@gmail.com [Beijing Key Laboratory of Clothing Materials R and D and Assessment, Beijing Institute of Fashion Technology, Beijing 100029 (China); Wang, Jiao-Na; Wang, Bin [Beijing Key Laboratory of Clothing Materials R and D and Assessment, Beijing Institute of Fashion Technology, Beijing 100029 (China); Gong, Jian Ru, E-mail: gongjr@nanoctr.cn [National Center for Nanoscience and Technology, China, 11 Zhongguancun Beiyitiao, Beijing 100190 (China); Lin, Zhang [Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fujian 350002 (China)

    2012-02-15

    Graphical abstract: A novel magnetically separable composite photocatalyst TiO{sub 2}/CoFe{sub 2}O{sub 4} nanofiber was prepared by sol-gel method and electrospinning technique, which can be reclaimed with a magnet, and the decolorizing efficiency of MB solution reached 95.87%. Highlights: Black-Right-Pointing-Pointer The composite TiO{sub 2}/CoFe{sub 2}O{sub 4} nanofibers with diameter of 110 {+-} 28 nm have been successfully synthesized by the combination of sol-gel method and electrospinning technique. Black-Right-Pointing-Pointer The presence of Co{sup 2+} or/and Fe{sup 3+} ions may occupy some of the lattice sites of TiO{sub 2} to form an iron-titanium solid solution and narrow the band gap, which broadens the response region of visible light. Black-Right-Pointing-Pointer The resultant nanofibers not only have high decomposition efficiency with methylene blue (MB) under the UV irradiation, which is close to that of Degussa P25, but also can be separated with a magnet and avoid the secondary pollution of the treated water. -- Abstract: A novel magnetically separable heterogeneous photocatalyst TiO{sub 2}/CoFe{sub 2}O{sub 4} nanofiber was prepared by sol-gel method and electrospinning technology, followed by heat treatment at 550 Degree-Sign C for 2 h. The phase structure, morphology and magnetic property of the composite nanofibers were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscope and vibrating sample magnetometer analysis. The photocatalytic studies of TiO{sub 2}/CoFe{sub 2}O{sub 4} fibers suggested that the presence of CoFe{sub 2}O{sub 4} not only enhanced the absorbance of UV light, but also broadened the response region to visible light. The decolorizing efficiency of methylene blue (MB) solution reaches 95.87% over TiO{sub 2}/CoFe{sub 2}O{sub 4} nanofibers under 300 W Hg lamp after 5 h, which is close to that of Degussa P25. Furthermore, these fibers can be collected with a magnet for reuse and effectively avoid the secondary pollution of the treated water.

  12. A novel magnetically separable TiO2/CoFe2O4 nanofiber with high photocatalytic activity under UV–vis light

    International Nuclear Information System (INIS)

    Graphical abstract: A novel magnetically separable composite photocatalyst TiO2/CoFe2O4 nanofiber was prepared by sol–gel method and electrospinning technique, which can be reclaimed with a magnet, and the decolorizing efficiency of MB solution reached 95.87%. Highlights: ► The composite TiO2/CoFe2O4 nanofibers with diameter of 110 ± 28 nm have been successfully synthesized by the combination of sol–gel method and electrospinning technique. ► The presence of Co2+ or/and Fe3+ ions may occupy some of the lattice sites of TiO2 to form an iron–titanium solid solution and narrow the band gap, which broadens the response region of visible light. ► The resultant nanofibers not only have high decomposition efficiency with methylene blue (MB) under the UV irradiation, which is close to that of Degussa P25, but also can be separated with a magnet and avoid the secondary pollution of the treated water. -- Abstract: A novel magnetically separable heterogeneous photocatalyst TiO2/CoFe2O4 nanofiber was prepared by sol–gel method and electrospinning technology, followed by heat treatment at 550 °C for 2 h. The phase structure, morphology and magnetic property of the composite nanofibers were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscope and vibrating sample magnetometer analysis. The photocatalytic studies of TiO2/CoFe2O4 fibers suggested that the presence of CoFe2O4 not only enhanced the absorbance of UV light, but also broadened the response region to visible light. The decolorizing efficiency of methylene blue (MB) solution reaches 95.87% over TiO2/CoFe2O4 nanofibers under 300 W Hg lamp after 5 h, which is close to that of Degussa P25. Furthermore, these fibers can be collected with a magnet for reuse and effectively avoid the secondary pollution of the treated water.

  13. Magnetically separable core-shell structural ?-Fe2O3@Cu/Al-MCM-41 nanocomposite and its performance in heterogeneous Fenton catalysis.

    Science.gov (United States)

    Ling, Yuhan; Long, Mingce; Hu, Peidong; Chen, Ya; Huang, Juwei

    2014-01-15

    To target the low catalytic activity and the inconvenient separation of copper loading nanocatalysts in heterogeneous Fenton-like reaction, a core-shell structural magnetically separable catalyst, with ?-Fe2O3 nanoparticles as the core layer and the copper and aluminum containing MCM-41 as the shell layer, has been fabricated. The role of aluminum has been discussed by comparing the copper containing mesoporous silica with various Cu contents. Their physiochemical properties have been characterized by XRD, UV-vis, FT-IR, TEM, nitrogen physisorption and magnetite susceptibility measurements. Double content Cu incorporation results in an improved catalytic activity for phenol degradation at the given condition (40C, initial pH=4), but leads to a declined BET surface area and less ordered mesophase structure. Aluminum incorporation helps to retain the high BET surface area (785.2m(2)/g) and the regular hexagonal mesoporous structure of MCM-41, which make the catalyst possess a lower copper content and even a higher catalytic activity than that with the double copper content in the absence of aluminum. The catalysts can be facilely separated by an external magnetic field for recycle usage. PMID:24295771

  14. Experimental investigation of inhomogeneities, nanoscopic phase separation, and magnetism in arc melted Fe-Cu metals with equal atomic ratio of the constituents

    KAUST Repository

    Hassnain Jaffari, G.

    2015-12-16

    Composition gradient and phase separation at the nanoscale have been investigated for arc-melted and solidified with equiatomic Fe-Cu. Diffraction studies revealed that Fe and Cu exhibited phase separation with no trace of any mixing. Microscopy studies revealed that immiscible Fe-Cu form dense bulk nanocomposite. The spatial distribution of Fe and Cu showed existence of two distinct regions, i.e., Fe-rich and Cu-rich regions. Fe-rich regions have Cu precipitates of various sizes and different shapes, with Fe forming meshes or channels greater than 100 nm in size. On the other hand, the matrix of Cu-rich regions formed strips with fine strands of nanosized Fe. Macromagnetic response of the system showed ferromagnetic behavior with a magnetic moment being equal to about 2.13 μB/Fe atom and a bulk like negligible value of coercivity over the temperature range of 5–300 K. Anisotropy constant has been calculated from various laws of approach to saturation, and its value is extracted to be equal to 1350 J/m3. Inhomogeneous strain within the Cu and Fe crystallites has been calculated for the (unannealed) sample solidified after arc-melting. Annealed sample also exhibited local inhomogeneity with removal of inhomogeneous strain and no appreciable change in magnetic character. However, for the annealed sample phase separated Fe exhibited homogenous strain.

  15. A Quantitative Determination of Magnetic Nanoparticle Separation Using On-Off Field Operation of Quadrupole Magnetic Field-Flow Fractionation (QMgFFF)

    Science.gov (United States)

    Orita, Toru; Moore, Lee R.; Joshi, Powrnima; Tomita, Masahiro; Horiuchi, Takashi; Zborowski, Maciej

    2014-01-01

    Quadrupole Magnetic Field-Flow Fractionation (QMgFFF) is a technique for characterization of sub-micrometer magnetic particles based on their retention in the magnetic field from flowing suspensions. Different magnetic field strengths and volumetric flow rates were tested using on-off field application and two commercial nanoparticle preparations that significantly differed in their retention parameter, ? (by nearly 8-fold). The fractograms showed a regular pattern of higher retention (98.6% v. 53.3%) for the larger particle (200 nm v. 90 nm) at the higher flow rate (0.05 mL/min v. 0.01 mL/min) at the highest magnetic field (0.52 T), as expected because of its lower retention parameter. The significance of this approach is a demonstration of a system that is simpler in operation than a programmed field QMgFFF in applications to particle mixtures consisting of two distinct particle fractions. This approach could be useful for detection of unwanted particulate contaminants, especially important in industrial and biomedical applications. PMID:23842422

  16. L-cysteine functionalized magnetic nanoparticles (LCMNP): a novel magnetically separable organocatalyst for one-pot synthesis of 2-amino-4H-chromene-3-carbonitriles in water.

    Science.gov (United States)

    Khalafi-Nezhad, Ali; Nourisefat, Maryam; Panahi, Farhad

    2015-07-28

    In this study, L-cysteine was chemically grafted to magnetic nanoparticles in order to prepare a reusable magnetic material incorporating an amino acid moiety. For this purpose, silica-coated magnetic nanoparticles (Fe3O4@SiO2) were reacted with trimethoxy(vinyl)silane to produce vinyl-functionalized magnetic nanoparticles (VMNP). Reaction of a VMNP substrate with L-cysteine in the presence of azobisisobutyronitrile (AIBN) resulted in the production of L-cysteine-functionalized magnetic nanoparticles (LCMNP). The LCMNP material was characterized using different microscopy and spectroscopy techniques such as FT-IR, XRD, TEM, SEM, EDX, VSM, and elemental analysis. Also, LCMNP was analyzed by thermogravimetric analysis (TGA) in order to determine its thermal behavior. The applicability of the LCMNP material was evaluated in a three-component coupling reaction between a nucleophile, salicylaldehyde and malononitrile as the catalyst for one-pot synthesis of 2-amino-4H-chromene-3-carbonitrile derivatives. The catalyst system showed high catalytic activity in this process and target products were obtained in high isolated yields in water as a green solvent. The LCMNP catalyst was reusable in this reaction at least 7 times with no significant decrease in its catalytic activity. PMID:26098281

  17. Magnetic field structure effect on the spatial flow in a supersonic MHD generator with boundary layer separation

    International Nuclear Information System (INIS)

    Calculational experiment for evaluating the role of the inhomogeneous two-component magnetic field constants in the MHD-channel is carried out. Difference of the medium-integral magnetic induction from the values on the axis is within the range of 2 up 4%. It is shown that availability of additional component of the magnetic field in the electrode direction in the channel cross sections intensifies the secondary flows and thereby increases the danger of the boundary layers break-off. The negative effect of the additional component by the beginning of the break-off regime is surpassed by stabilizing effect from decrease in the basic component to electrodes. By developed break-off flow the effects related to the availability of the additional component are prevailing

  18. Data logging and control of the magnetic optic element currents of separated beams with the help of the M-6000 computer

    International Nuclear Information System (INIS)

    Presented is a description of automation system (ACS) for controlling the operation of magnetic optical elements (MOE) of separated beam channels for the MIRABEL chamber. MOE comprise 6 beam bending magnets and 24 quadrupole lenses. Current control was performed with the M-6000 computer and A-200 digital voltmeter. The system of manual control of MOE currents was used. Structural sheams of ACS and interface device of the A-200 are presented along with test results, block diagram of the control program and MOE operation monitoring, performances of automatic control at the operation with MOE. It has been stated as a result of the ACS performance testing that mean time of the tuning of an element is equal to 30 s while measuring for 0.5 V; the above parameter for more than 5 elements is equal to 2-4 min while measuring for 1 V, and it is not practically dependent on the number of elements being tuned

  19. A self-consistent two-dimensional resistive fluid theory of field-aligned potential structures including charge separation and magnetic and velocity shear

    International Nuclear Information System (INIS)

    A self-consistent two-fluid theory that includes the magnetic field and shear patterns therein is developed to model stationary electrostatic structures with field-aligned potential drops. Shear flow is also included in the theory since this seems to be a prominent feature of the structures of interest. In addition, Ohmic dissipation, a Hall term and pressure gradients in a generalized Ohm's law, modified for cases without quasi-neutrality are included. In the analytic theory, the electrostatic force is balanced by field-aligned pressure gradients, i.e., thermal effects in the direction of the magnetic field, and by pressure gradients and magnetic stresses in the perpendicular direction. Within this theory simple examples of applications are presented to demonstrate the kind of solutions resulting from the model. The results show how the effects of charge separation and shear in the magnetic field and the velocity can be combined to form self-consistent structures such as are found to exist above the aurora, suggested also in association with solar flares

  20. Volume reduction on all particle size of the contaminated soil. Continuous processing technology of attrition, chemical wash under an ambient temperature and pressure condition and magnetic separation

    International Nuclear Information System (INIS)

    An examination was conducted in order to establish a practical purification system that could largely reduce the storage volume of radioactive waste in the Intermediate Storage Facility. The examination consists of a 3-step washing treatment of contaminated soil, which includes “Milling Washing” of removed contaminated soil, chemical extraction of fine soil fraction resulted from the “Milling Washing” under an ambient temperature and pressure condition, and magnetic separation of cesium from the extracted solution. As a result of the examination, we succeeded in development of a safe system with low initial cost and running cost. (author)

  1. Three Birds with One Fe3O4 Nanoparticle: Integration of Microwave Digestion, Solid Phase Extraction, and Magnetic Separation for Sensitive Determination of Arsenic and Antimony in Fish.

    Science.gov (United States)

    Jia, Yun; Yu, Huimin; Wu, Li; Hou, Xiandeng; Yang, Lu; Zheng, Chengbin

    2015-06-16

    An environmentally friendly and fast sample treatment approach that integrates accelerated microwave digestion (MWD), solid phase extraction, and magnetic separation into a single step was developed for the determination of arsenic and antimony in fish samples by using Fe3O4 magnetic nanoparticles (MNPs). Compared to conventional microwave digestion, the consumption of HNO3 was reduced significantly to 12.5%, and the digestion time and temperature were substantially decreased to 6 min and 80 C, respectively. This is largely attributed to Fe3O4 magnetic nanoparticles being a highly effective catalyst for rapid generation of oxidative radicals from H2O2, as well as an excellent absorber of microwave irradiation. Moreover, potential interferences from sample matrices were eliminated because the As and Sb species adsorbed on the nanoparticles were efficiently separated from the digests with a hand-held magnet prior to analysis. Limits of detection for arsenic and antimony were in the range of 0.01-0.06 ?g g(-1) and 0.03-0.08 ?g g(-1) by using hydride generation atomic fluorescence spectrometry, respectively, and further improved to 0.002-0.005 ?g g(-1) and 0.005-0.01 ?g g(-1) when inductively coupled plasma mass spectrometry was used as a detector. The precision of replicate measurements (n = 9) was better than 6% by analyzing 0.1 g test sample spiked with 1 ?g g(-1) arsenic and antimony. The proposed method was validated by analysis of two certified reference materials (DORM-3 and DORM-4) with good recoveries (90%-106%). PMID:25962876

  2. Magnetically assisted chemical separation (MACS): a promising technique for the uptake of actinides, lanthanides and fission products from nuclear wastes

    International Nuclear Information System (INIS)

    The present work deals with the development of MACS process for the uptake of various actinides, lanthanides and fission products from nitric acid solutions using tiny magnetic particles (cross-linked polyacrylamide and acrylic acid entrapping charcoal and iron oxide, 1:1:1, particle size 1-60 ?m) coated with N,N'-dimenthyl N,N'-dubutyl tetradecyl melonamide (DMDBTDMA)

  3. Resource Recovery and Reuse: Recycled Magnetically Separable Iron-based Catalysts for Phosphate Recovery and Arsenic Removal

    Science.gov (United States)

    Environmentally friendly processes that aid human and environmental health include recovering, recycling, and reusing limited natural resources and waste materials. In this study, we re-used Iron-rich solid waste materials from water treatment plants to synthesize magnetic iron-o...

  4. Sm1-xSrxMnO3 manganites: unusual magnetic, electric and elastic properties due to phase separation

    International Nuclear Information System (INIS)

    Colossal magnetoresistance (CMR) (??/?) and giant negative volume magnetostriction (?) have been observed in the Curie temperature region of Sm1-xSrxMnO3 manganites, for x=0.33 compounds containing ferromagnetic (FM) and A-type antiferromagnetic (AFM) clusters and for x 0.4, 0.45 compounds containing FM and both types of AFM clusters (A-type and charge-ordering (CO) type). For x=0.33, the magnetization ?, ??/? and ? increase smoothly with magnetic field increase and saturation of ??/? and ? is not achieved. Isotherms of ?, ??/? and ? for x=0.4 and 0.45 show another behaviour: sharp jumps of ?, ??/? and ? take place at HC1?H?HC2, and saturation is achieved at H?HC2. We consider that the reason for CMR and giant magnetostriction being observed in the compounds investigated is the increase of the FM phase volume under the action of the magnetic field. For x=0.33 this increase is smooth because it arises from FM phase 'sprouting' on FM layers of A-type AFM phase. For x=0.4 and 0.45 the increase of the volume of the FM part arises from CO clusters with CE-type AFM structure too. In this case, CO clusters are completely transformed to the FM state with a large saturation magnetization ?s which is equal to ?70% of ?s at T=1.5 K. This transition is accompanied by crystal structure reconstruction that is manifested in both the temperature and magnetic field dependences of the anisotropic magnetostriction. (author). Letter-to-the-editor

  5. Magnets

    International Nuclear Information System (INIS)

    A magnet pole piece for an NMR imaging magnet is made of a plurality of magnetic wires with one end of each wire held in a non-magnetic spacer, the other ends of the wires being brought to a pinch, and connected to a magnetic core. The wires may be embedded in a synthetic resin and the magnetisation and uniformity thereof can be varied by adjusting the density of the wires at the spacer which forms the pole piece. (author)

  6. Synthesis of Cu-Fe3O4@graphene composite: A magnetically separable and efficient catalyst for the reduction of 4-nitrophenol

    International Nuclear Information System (INIS)

    Highlights: The Cu-Fe3O4@GE composite was prepared by one-step solventthermal method. The Cu-Fe3O4@GE composite exhibited the highest catalytic activity with excellent stability. The Cu-Fe3O4@GE composite was magnetically separable. - Abstract: In this work, the Cu-Fe3O4@GE composite was prepared easily by a one-step solventthermal method, which achieved the formation of Cu nanoparticles (Cu NPs), Fe3O4 nanoparticles (Fe3O4 NPs) and reduction of GO simultaneously. The morphology and structure of the composite was fully characterized by means of X-ray diffraction (XRD), Fourier transformed infrared (FTIR) spectroscopy, transmission electron microscopy (TEM). The time-dependent adsorption spectra of the reaction mixture was measured by UVvis absorption spectroscopy. The results demonstrated that the Cu NPs and Fe3O4 NPs were densely and evenly deposited on the graphene (GE) sheets. It was found that the Cu-Fe3O4@GE composite exhibited high catalytic activities on the reduction of p-nitrophenol to p-aminophenol. Furthermore, the composite catalyst can be easily recovered due to its magnetic separability and high stability

  7. Adsorption of phosphate from water by easily separable Fe3O4@SiO2 core/shell magnetic nanoparticles functionalized with hydrous lanthanum oxide.

    Science.gov (United States)

    Lai, Li; Xie, Qiang; Chi, Lina; Gu, Wei; Wu, Deyi

    2016-03-01

    Hydrous lanthanum oxide was loaded onto the surface of Fe3O4@SiO2 core/shell magnetic nanoparticles to obtain an easily separable adsorbent (abbreviated as Fe-Si-La) for efficient separation of phosphate from water. Fe-Si-La was characterized with XRF, XRD, TEM, specific surface area and magnetization and their performance for phosphate removal was investigated. The Fe3O4@SiO2 core/shell structure was confirmed and the hydrous lanthanum oxide was successfully loaded onto its surface. The newly developed adsorbent had magnetization of 51.27emu/g. The Langmuir adsorption capacity of phosphate by Fe-Si-La reached 27.8mg/g by loading only 1mmol lanthanum per gram of magnetite. The adsorption was fast; nearly 99% of phosphate could be removed within 10min. The removal of phosphate was favored within the pH range 5.0-9.0. The adsorption on Fe-Si-La was not significantly influenced by ionic strength and by the coexistence of the anions of chloride and nitrate but sulfate, bicarbonate and humic acid showed slightly greater negative effects. Phosphate removal efficiency of higher than 95% was attained for real effluent of a wastewater treatment plant when the dose of adsorbent was >0.2kg/ton. The results showed that adsorbed phosphate could be nearly completely desorbed with NaOH solution for further use. In conclusion, Fe-Si-La is a promising adsorbent for the removal and recovery of phosphate from water. PMID:26641568

  8. Efficient separation and sensitive detection of Listeria monocytogenes using an impedance immunosensor based on magnetic nanoparticles, a microfluidic chip, and an interdigitated microelectrode.

    Science.gov (United States)

    Kanayeva, Damira A; Wang, Ronghui; Rhoads, Douglas; Erf, Gisela F; Slavik, Michael F; Tung, Steve; Li, Yanbin

    2012-11-01

    Listeria monocytogenes continues to be a major foodborne pathogen that causes food poisoning, and sometimes death, among immunosuppressed people and abortion among pregnant women. In this study, magnetic nanoparticles with a diameter of 30 nm were functionalized with anti-L. monocytogenes antibodies via biotin-streptavidin bonds to become immunomagnetic nanoparticles (IMNPs) to capture L. monocytogenes in a sample during a 2-h immunoreaction. A magnetic separator was used to collect and hold the IMNPs-L. monocytogenes complex while the supernatants were removed. After the washing step, the nanoparticle-L. monocytogenes complex was separated from the sample and injected into a microfluidic chip. The impedance change caused by L. monocytogenes was measured by an impedance analyzer through the interdigitated microelectrode in the microfluidic chip. For L. monocytogenes in phosphate-buffered saline solution, up to 75% of the cells in the sample could be separated, and as few as three to five cells in the microfluidic chip could be detected, which is equivalent to 10(3) CFU/ml of cells in the original sample. The detection of L. monocytogenes was not interfered with by other major foodborne bacteria, including E. coli O157:H7, E. coli K-12, L. innocua, Salmonella Typhimurium, and Staphylococcus aureus. A linear correlation (R(2) = 0.86) was found between the impedance change and the number of L. monocytogenes in a range of 10(3) to 10(7) CFU/ml. Equivalent circuit analysis indicated that the impedance change was mainly due to the decrease in medium resistance when the IMNPs-L. monocytogenes complexes existed in mannitol solution. Finally, the immunosensor was evaluated with food sample tests; the results showed that, without preenrichment and labeling, 10(4) and 10(5) CFU/ml L. monocytogenes in lettuce, milk, and ground beef samples could be detected in 3 h. PMID:23127703

  9. Selective separation of mercury(II) using magnetic chitosan resin modified with Schiff's base derived from thiourea and glutaraldehyde

    International Nuclear Information System (INIS)

    Magnetic chitosan resin was chemically modified by a Schiff's base cross-linker. The interaction of the resin obtained with Hg(II) was studied and uptake value of 2.8 mmol/g was reported. The kinetic and thermodynamic parameters of the adsorption process were estimated. These data indicated that the adsorption process is exothermic and follow the pseudo-second-order kinetics. The selectivity of Hg(II) from other different metal ions in solutions using the studied resin was also reported. Breakthrough curves for the recovery of Hg(II) were studied. The critical bed height was found to be 2.05 cm. The adsorbed Hg(II) was eluted from the resin effectively using 0.1 M potassium iodide

  10. Wide aperture kinematical separator COMBAS

    International Nuclear Information System (INIS)

    The high-resolving wide aperture separator COMBAS with advanced ion-optical characteristics has been designed and commissioned at the FLNR JINR. For the first time in the world, the strong focusing magneto-optical system has been realized on the base of wide-aperture bending magnets. The magnetic optics of the separator is formed by a cascade of eight magnets with alternating sign of the quadrupole component of the magnetic field from magnet to magnet. Fields of all the magnets contain sextupole and octupole components in order to compensate higher order aberration. (author)

  11. Potential environmental benefits of improving recycling of polyolefines – LCA of Magnetic density separation (MDS) developed in the EU FP7 funded project W2Plastic

    DEFF Research Database (Denmark)

    Olsen, Stig Irving; Bonou, Alexandra

    identify eco-design criteria for the development and secondly to document the potential environmental improvement of polyolefin recycling using the MDS technology. A preliminary study focusing solely on the carbon footprint benefits of recycling plastic waste compared to virgin production of polymers...... showed that there are large benefits to recycling. However, including other uses of the waste illustrates that the benefits to a large extent depend on that the recycled plastic have such high quality that it can actually replace virgin plastic and also to some extent depends on which energy systems e......The core of the EU FP7 funded project W2Plastic is development of a magnetic density separation (MDS) of polyolefines in order to improve the sorting efficiency of these polymer types in different waste fractions. As part of the project a life cycle assessment is performed in order to firstly...

  12. Potential environmental benefits of improving recycling of polyolefines LCA of Magnetic density separation (MDS) developed in the EU FP7 funded project W2Plastic

    DEFF Research Database (Denmark)

    Olsen, Stig Irving; Bonou, Alexandra

    2012-01-01

    The core of the EU FP7 funded project W2Plastic is development of a magnetic density separation (MDS) of polyolefines in order to improve the sorting efficiency of these polymer types in different waste fractions. As part of the project a life cycle assessment is performed in order to firstly identify eco-design criteria for the development and secondly to document the potential environmental improvement of polyolefin recycling using the MDS technology. A preliminary study focusing solely on the carbon footprint benefits of recycling plastic waste compared to virgin production of polymers showed that there are large benefits to recycling. However, including other uses of the waste illustrates that the benefits to a large extent depend on that the recycled plastic have such high quality that it can actually replace virgin plastic and also to some extent depends on which energy systems e.g. energy recovery from incineration substitutes.

  13. Characterization of flavonoid glycosides from rapeseed bee pollen using a combination of chromatography, spectrometry and nuclear magnetic resonance with a step-wise separation strategy.

    Science.gov (United States)

    Li, Yi; Qi, Yitao; Ritho, Joan; Zhang, Yongxin; Zheng, Xiaowei; Zhou, Jinhui; Sun, Liping

    2016-01-01

    To identify the structures of flavonoid glycosides in bee pollen collected from rapeseed plants (Brassica napus L.), we utilised an approach that combined liquid chromatography-diode array detector-electrospray ionization-mass spectrometry (LC-DAD-ESI-MS) and nuclear magnetic resonance (NMR) technology with a step-wise separation strategy. We identified four constituents of high purity in rape bee pollen samples: (1) quercetin-3-O-?-D-glucosyl-(2?l)-?-glucoside, (2) kaempferol-3, 4'-di-O-?-D-glucoside, (3) 5, 7, 4'-trihydroxy-3'-methoxyflavone-3-O-?-D-sophoroside and (4) kaempferol-3-O-?-D-glucosyl-(2?l)-?-D-glucoside. This study will also provide useful reference standards for qualification and quantification of four flavonoid glycosides in natural products. PMID:25981986

  14. Well-Combined Magnetically Separable Hybrid Cobalt Ferrite/Nitrogen-Doped Graphene as Efficient Catalyst with Superior Performance for Oxygen Reduction Reaction.

    Science.gov (United States)

    Lu, Lei; Hao, Qingli; Lei, Wu; Xia, Xifeng; Liu, Peng; Sun, Dongping; Wang, Xin; Yang, Xujie

    2015-11-01

    Catalysts with low-cost, high activity and stability toward oxygen reduction reaction (ORR) are extremely desirable, but its development still remains a great challenge. Here, a novel magnetically separable hybrid of multimetal oxide, cobalt ferrite (CoFe2 O4 ), anchored on nitrogen-doped reduced graphene oxide (CoFe2 O4 /NG) is prepared via a facile solvothermal method followed by calcination at 500 C. The structure of CoFe2 O4 /NG and the interaction of both components are analyzed by several techniques. The possible formation of Co/Fe?N interaction in the CoFe2 O4 /NG catalyst is found. As a result, the well-combination of CoFe2 O4 nanoparticles with NG and its improved crystallinity lead to a synergistic and efficient catalyst with high performance to ORR through a four-electron-transfer process in alkaline medium. The CoFe2 O4 /NG exhibits particularly comparable catalytic activity as commercial Pt/C catalyst, and superior stability against methanol oxidation and CO poisoning. Meanwhile, it has been proved that both nitrogen doping and the spinel structure of CoFe2 O4 can have a significant contribution to the catalytic activity by contrast experiments. Multimetal oxide hybrid demonstrates better catalysis to ORR than a single metal oxide hybrid. All results make the low-cost and magnetically separable CoFe2 O4 /NG a promising alternative for costly platinum-based ORR catalyst in fuel cells and metal-air batteries. PMID:26390018

  15. Dispersive solid phase microextraction with magnetic graphene oxide as the sorbent for separation and preconcentration of ultra-trace amounts of gold ions.

    Science.gov (United States)

    Kazemi, Elahe; Dadfarnia, Shayessteh; Haji Shabani, Ali Mohammad

    2015-08-15

    A selective, simple and rapid dispersive solid phase microextraction was developed using magnetic graphene oxide (MGO) as an efficient sorbent for the separation and preconcentration of gold ions. The MGO was synthesized by means of the simple one step chemical coprecipitation method, characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). Gold ions retained by the sorbent were eluted using 0.5mol L(-)(1) thiourea in 0.1mol L(-1) HCl solution and determined by the flow injection flame atomic absorption spectrometry (FI-FAAS). The factors affecting the separation and preconcentration of gold were investigated and optimized. Under the optimized conditions, the method exhibited a linear dynamic range of 0.02-100.0g L(-)(1) with a detection limit of 4ng L(-1) and an enrichment factor of 500. The relative standard deviations of 3.2% and 4.7% (n=6) were obtained at 20g L(-1) level of gold ions for the intra and the inter day analysis, respectively. The method was successfully applied to the determination of gold ions in water and waste water samples as well as a certified reference material (CCU-1b, copper flotation concentrate). PMID:25966414

  16. Effective connection of phase-separated metallic pathways under low magnetic fields in charge-ordered insulators of micropatterned perovskite manganite thin films

    International Nuclear Information System (INIS)

    We investigated the probe size dependence of the electrical transport properties of perovskite manganite La0.67Ca0.33MnO3 (LCMO) films with electronic phase separation (EPS) between ferromagnetic metal and charge-ordered insulator phases. A micropatterned wire was fabricated by an excimer-laser-assisted metal organic deposition process. A patterned wire of an LCMO film with a width of 10 ?m had a higher insulator-metal transition temperature associated with the ferromagnetic transition than that of an LCMO film with a large probe size. Moreover, a low-magnetic-field magnetoresistance (LFMR) effect was observed for the micropatterned wire film; the resistivity decreased only from H perpendicular c > 0.02 T. The origin of this LFMR effect is thought to be the effective connections of the ferromagnetic metal domains between the probe contacts with small dimensions similar to the size of the phase-separated metal and insulator domains. These properties were qualitatively explained by numerical simulations of resistance variations for different probe sizes. (author)

  17. Optimization of a phase separation based magnetic-stirring salt-induced liquid-liquid microextraction method for determination of fluoroquinolones in food.

    Science.gov (United States)

    Gao, Ming; Wang, Huili; Ma, Meiping; Zhang, Yuna; Yin, Xiaohan; Dahlgren, Randy A; Du, Dongli; Wang, Xuedong

    2015-05-15

    Herein, we developed a novel integrated apparatus to perform phase separation based on magnetic-stirring, salt-induced, liquid-liquid microextraction for determination of five fluoroquinolones in animal-based foods by HPLC analysis. The novel integrated apparatus consisted of three simple HDPE (high density polyethylene) parts that were used to separate the solvent from the aqueous solution prior to retrieving the extractant. The extraction parameters were optimized using the response surface method based on central composite design: 791 ?L of acetone solvent, 2.5 g of Na2SO4, pH 1.7, 3.0 min of stir time, and 5.5 min centrifugation. The limits of detection were 0.07-0.53 ?g kg(-1) and recoveries were 91.6-105.0% for the five fluoroquinolones from milk, eggs and honey. This method is easily constructed from inexpensive materials, extraction efficiency is high, and the approach is compatible with HPLC analysis. Thus, it has excellent prospects for sample pre-treatment and analysis of fluoroquinolones in animal-based foods. PMID:25577068

  18. Kinetic, isotherm and thermodynamic investigations of phosphate adsorption onto core-shell Fe?O?@LDHs composites with easy magnetic separation assistance.

    Science.gov (United States)

    Yan, Liang-guo; Yang, Kun; Shan, Ran-ran; Yan, Tao; Wei, Jing; Yu, Shu-jun; Yu, Hai-qin; Du, Bin

    2015-06-15

    In this study, three different magnetic core-shell Fe3O4@LDHs composites, Fe3O4@Zn-Al-, Fe3O4@Mg-Al-, and Fe3O4@Ni-Al-LDH were prepared via a rapid coprecipitation method for phosphate adsorptive removal. The composites were characterized by XRD, FTIR, TEM, VSM and BET analyses. Characterization results proved the successful synthesis of core-shell Fe3O4@LDHs composites with good superparamagnetisms. Batch experiments were conducted to study the adsorption efficiency of phosphate. Optimal conditions for the phosphate adsorption were obtained: 0.05 g of adsorbent, solution pH of 3, and contact time of 60 min. Proposed mechanisms for the removal of phosphate species onto Fe3O4@LDHs composites at different initial solution pH were showed. The kinetic data were described better by the pseudo-second-order kinetic equation and KASRA model. The adsorption isotherm curves showed a three-region behavior in the ARIAN model. It had a good fit with Langmuir model and the maximum adsorption capacity followed the order of Fe3O4@Zn-Al-LDH>Fe3O4@Mg-Al-LDH>Fe3O4@Ni-Al-LDH. Thermodynamic analyses indicated that the phosphate adsorption process was endothermic and spontaneous in nature. The three Fe3O4@LDHs composites could be easily separated from aqueous solution by the external magnetic field in 10s. These novel magnetic core-shell Fe3O4@LDHs adsorbents may offer a simple single step adsorption treatment option to remove phosphate from water without the requirement of pre-/post-treatment for current industrial practice. PMID:25778739

  19. MAGNET

    CERN Multimedia

    by B. Curé

    2011-01-01

    The magnet operation was very satisfactory till the technical stop at the end of the year 2010. The field was ramped down on 5th December 2010, following the successful regeneration test of the turbine filters at full field on 3rd December 2010. This will limit in the future the quantity of magnet cycles, as it is no longer necessary to ramp down the magnet for this type of intervention. This is made possible by the use of the spare liquid Helium volume to cool the magnet while turbines 1 and 2 are stopped, leaving only the third turbine in operation. This obviously requires full availability of the operators to supervise the operation, as it is not automated. The cryogenics was stopped on 6th December 2010 and the magnet was left without cooling until 18th January 2011, when the cryoplant operation resumed. The magnet temperature reached 93 K. The maintenance of the vacuum pumping was done immediately after the magnet stop, when the magnet was still at very low temperature. Only the vacuum pumping of the ma...

  20. Magnetically separable Prussian blue analogue Mn3[Co(CN)6]2.nH2O porous nanocubes as excellent absorbents for heavy metal ions

    Science.gov (United States)

    Hu, Lin; Mei, Ji-Yang; Chen, Qian-Wang; Zhang, Ping; Yan, Nan

    2011-10-01

    The application of Prussian blue analogue (PBA) Mn3[Co(CN)6]2.nH2O porous nanocubes as absorbents for heavy metal ions has been demonstrated. The result indicates that Mn3[Co(CN)6]2.nH2O porous nanocubes with average diameter of 240 nm possess excellent adsorption efficiency for Pb2+ ions (94.21% at initial Pb2+ concentration of 10 mg L-1). Moreover, Mn3[Co(CN)6]2.nH2O porous nanocubes can also show high adsorption efficiency on heavy metal ions even in a strong acidic solution due to its chemical stability. Notably, an external magnet could be used to accelerate the separation of Mn3[Co(CN)6]2.nH2O from the treated solution. It is suggested that the high adsorption efficiency may derive from the large surface area, M3II[MIII(CN)6]2.nH2O porous framework structure and affinity between polarizable π-electron clouds of the cyanide bridges and heavy metals ions.The application of Prussian blue analogue (PBA) Mn3[Co(CN)6]2.nH2O porous nanocubes as absorbents for heavy metal ions has been demonstrated. The result indicates that Mn3[Co(CN)6]2.nH2O porous nanocubes with average diameter of 240 nm possess excellent adsorption efficiency for Pb2+ ions (94.21% at initial Pb2+ concentration of 10 mg L-1). Moreover, Mn3[Co(CN)6]2.nH2O porous nanocubes can also show high adsorption efficiency on heavy metal ions even in a strong acidic solution due to its chemical stability. Notably, an external magnet could be used to accelerate the separation of Mn3[Co(CN)6]2.nH2O from the treated solution. It is suggested that the high adsorption efficiency may derive from the large surface area, M3II[MIII(CN)6]2.nH2O porous framework structure and affinity between polarizable π-electron clouds of the cyanide bridges and heavy metals ions. Electronic supplementary information (ESI) available. See DOI: 10.1039/c1nr10506j

  1. MAGNET

    CERN Multimedia

    B. Curé

    2012-01-01

      The magnet was energised at the beginning of March 2012 at a low current to check all the MSS safety chains. Then the magnet was ramped up to 3.8 T on 6 March 2012. Unfortunately two days later an unintentional switch OFF of the power converter caused a slow dump. This was due to a misunderstanding of the CCC (CERN Control Centre) concerning the procedure to apply for the CMS converter control according to the beam-mode status at that time. Following this event, the third one since 2009, a discussion was initiated to define possible improvement, not only on software and procedures in the CCC, but also to evaluate the possibility to upgrade the CMS hardware to prevent such discharge from occurring because of incorrect procedure implementations. The magnet operation itself was smooth, and no power cuts took place. As a result, the number of magnetic cycles was reduced to the minimum, with only two full magnetic cycles from 0 T to 3.8 T. Nevertheless the magnet suffered four stops of the cryogeni...

  2. MAGNET

    CERN Multimedia

    B. Curé

    2012-01-01

      Following the unexpected magnet stops last August due to sequences of unfortunate events on the services and cryogenics [see CMS internal report], a few more events and initiatives again disrupted the magnet operation. All the magnet parameters stayed at their nominal values during this period without any fault or alarm on the magnet control and safety systems. The magnet was stopped for the September technical stop to allow interventions in the experimental cavern on the detector services. On 1 October, to prepare the transfer of the liquid nitrogen tank on its new location, several control cables had to be removed. One cable was cut mistakenly, causing a digital input card to switch off, resulting in a cold-box (CB) stop. This tank is used for the pre-cooling of the magnet from room temperature down to 80 K, and for this reason it is controlled through the cryogenics control system. Since the connection of the CB was only allowed for a field below 2 T to avoid the risk of triggering a fast d...

  3. MAGNET

    CERN Multimedia

    Benoit Cur

    2010-01-01

    Operation of the magnet has gone quite smoothly during the first half of this year. The magnet has been at 4.5K for the full period since January. There was an unplanned short stop due to the CERN-wide power outage on May 28th, which caused a slow dump of the magnet. Since this occurred just before a planned technical stop of the LHC, during which access in the experimental cavern was authorized, it was decided to leave the magnet OFF until 2nd June, when magnet was ramped up again to 3.8T. The magnet system experienced a fault also resulting in a slow dump on April 14th. This was triggered by a thermostat on a filter choke in the 20kA DC power converter. The threshold of this thermostat is 65C. However, no variation in the water-cooling flow rate or temperature was observed. Vibration may have been the root cause of the fault. All the thermostats have been checked, together with the cables, connectors and the read out card. The tightening of the inductance fixations has also been checked. More tem...

  4. Detection of hepatitis A virus in seeded oyster digestive tissue by ricin A-linked magnetic separation combined with reverse transcription PCR.

    Science.gov (United States)

    Ko, Sang-Mu; Vaidya, Bipin; Kwon, Joseph; Lee, Hee-Min; Oh, Myung-Joo; Shin, Tai-Sun; Cho, Se-Young; Kim, Duwoon

    2015-05-01

    Outbreaks of hepatitis A virus (HAV) infections are most frequently associated with the consumption of contaminated oysters. A rapid and selective concentration method is necessary for the recovery of HAV from contaminated oysters prior to detection using PCR. In this study, ricin extracted from castor beans (Ricinus communis) was tested as an alternative to antibody used in immunomagnetic separation while concentrating HAV prior to its detection using reverse transcription PCR. Initially, the extracted proteins from castor beans were fractionated into 13 fractions by gel filtration chromatography. Pretreatment of different protein fractions showed a variation in binding of HAV viral protein (VP) 1 to oyster digestive tissue in the range of 25.9 to 63.9%. The protein fraction, which caused the highest reduction in binding of VP1 to the tissue, was identified as ricin A by quadrupole time-of-flight mass spectrometry. Ricin A could significantly inhibit binding of VP1 to the tissue with a 50% inhibitory concentration of 4.5 ?g/ml and a maximal inhibitory concentration of 105.2%. The result showed that the rate of inhibition of HAV binding to tissue was higher compared to the rate of ricin itself binding to HAV (slope: 0.0029 versus 0.00059). However, ricin A concentration showed a higher correlation to the relative binding of ricin itself to HAV than the inhibition of binding of HAV to the tissue (coefficient of determination, R(2): 0.9739 versus 0.6804). In conclusion, ricin A-linked magnetic bead separation combined with reverse transcription PCR can successfully detect HAV in artificially seeded oyster digestive tissue up to a 10(-4) dilution of the virus stock (titer: 10(4) 50% tissue culture infective dose per ml). PMID:25951406

  5. Neptunium separations

    International Nuclear Information System (INIS)

    Two procedures for the separation of Np are presented; the first involves separation of 239Np from irradiated 238U, and the second involves separation of 237Np from a solution representing that from a dissolved fuel element

  6. Magnetically separable reactive sorbent based on the CeO2/?-Fe2O3 composite and its utilization for rapid degradation of the organophosphate pesticide parathion methyl and certain nerve agents.

    Czech Academy of Sciences Publication Activity Database

    Jano, P.; Kur?, P.; Pila?ov, V.; Trgl, J.; ?astn, M.; Pelant, O.; Henych, Ji?; Bakardjieva, Snejana; ivotsk, O.; Kormunda, M.; Mazanec, K.; Skoumal, M.

    2015-01-01

    Ro?. 262, FEB (2015), s. 747-755. ISSN 1385-8947 R&D Projects: GA ?R(CZ) GAP106/12/1116 Institutional support: RVO:61388980 Keywords : Magnetically separable sorbent * Destructive sorption * Cerium oxide * Parathion methyl * Toxic organophosphates Subject RIV: CA - Inorganic Chemistry Impact factor: 4.321, year: 2014

  7. Magnetization steps in the phase separated manganite La0.275Pr0.35Ca0.375MnO3

    International Nuclear Information System (INIS)

    The low temperature magnetic properties of the La0.275Pr0.35Ca0.375MnO3 manganite have been investigated. Step-like charge ordered antiferromagnetic (AFM)-ferromagnetic (FM) transition is observed in the magnetic field dependence of magnetization M(H) curve below 200 K as the applied magnetic field is only several Tesla, and the magnetic step become ultrasharp at 2 K. The onset magnetic field of the step decreases initially and then increases with increasing temperatures and the critical magnetic field is sensitive to the magnetic history. The results are discussed according to the field-induced reduction of the distortion of Mn?O octahedron as martensitic mechanism. The magnetic phase diagram is also constructed based on the magnetic measurements

  8. A separation mechanism of photogenerated charges and magnetic properties for BiFeO3 microspheres synthesized by a facile hydrothermal method.

    Science.gov (United States)

    Zheng, Haiwu; Liu, Xiangyang; Diao, Chunli; Gu, Yuzong; Zhang, Weifeng

    2012-06-21

    BiFeO(3) (BFO) microspheres were synthesized by a facile hydrothermal method. The optical absorption spectrum indicates that on site Fe(3+) crystal-field transitions and the charge transfer excitations can be observed. Magnetic measurements show a spin-glass behavior and room temperature weak ferromagnetism. The surface photovoltage spectroscopy of the BFO shows two response peaks centered at about 370 and 400 nm, respectively. Under an ambient atmosphere, the maximum surface photovoltage of the BFO reaches 180 ?V with the bias (+2 V) and is three times larger than that with zero bias. It is found that the surface photovoltage response intensity increases with an increase in applied bias, regardless of positive or negative bias. It is suggested that the surface photovoltaic properties are related to both the depolarization field owing to ferroelectric polarization and the build-in electric field due to the Schottky barrier. The micro-process and the physical mechanism of the separation of photogenerated charges for BFO are fully explained. PMID:22588092

  9. Preparation of magnetically separable Fe{sub 3}O{sub 4}/BiOI nanocomposites and its visible photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiangwei; Niu, Chenggang, E-mail: cgniu@hnu.edu.cn; Huang, Dawei; Wang, Xiaoyu; Zhang, Xuegang; Zeng, Guangming, E-mail: zgming@hnu.edu.cn; Niu, Qiuya

    2013-12-01

    Novel magnetic Fe{sub 3}O{sub 4}/BiOI nanocomposites with visible light response were successfully fabricated through a facile and economical method at low temperature and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED), respectively. The Fe{sub 3}O{sub 4}/BiOI nanocomposites were further employed in photodegrading rhodamine B (RhB). After 40 min, RhB removal rate reached to 90.1%, which was superior to the pure BiOI (50.3%). The enhanced photocatalytic performance of Fe{sub 3}O{sub 4}/BiOI nanocomposites may be attributed to the separation efficiency of the carriers. After five recycles for the photodegradation of RhB, the Fe{sub 3}O{sub 4}/BiOI nanocomposites did not exhibit any significant loss of activity, confirming the photocatalyst was essentially stable. Moreover, direct hole transfers and O{sub 2}{sup ?} are proved to be the dominant reactive species in the photodegradation of RhB over Fe{sub 3}O{sub 4}/BiOI nanocomposites.

  10. MAGNET

    CERN Multimedia

    Benoit Curé

    2010-01-01

    The magnet was successfully operated at the end of the year 2009 despite some technical problems on the cryogenics. The magnet was ramped up to 3.8 T at the end of November until December 16th when the shutdown started. The magnet operation met a few unexpected stops. The field was reduced to 3.5 T for about 5 hours on December 3rd due to a faulty pressure sensor on the helium compressor. The following day the CERN CCC stopped unintentionally the power converters of the LHC and the experiments, triggering a ramp down that was stopped at 2.7 T. The magnet was back at 3.8 T about 6 hours after CCC sent the CERN-wide command. Three days later, a slow dump was triggered due to a stop of the pump feeding the power converter water-cooling circuit, during an intervention on the water-cooling plant done after several disturbances on the electrical distribution network. The magnet was back at 3.8 T in the evening the same day. On December 10th a break occurred in one turbine of the cold box producing the liquid ...

  11. MAGNET

    CERN Multimedia

    B. Curé

    2012-01-01

      The magnet and its sub-systems were stopped at the beginning of the winter shutdown on 8th December 2011. The magnet was left without cooling during the cryogenics maintenance until 17th January 2012, when the cryoplant operation resumed. The magnet temperature reached 93 K. The vacuum pumping was maintained during this period. During this shutdown, the yearly maintenance was performed on the cryogenics, the vacuum pumps, the magnet control and safety systems, and the power converter and discharge lines. Several preventive actions led to the replacement of the electrovalve command coils, and the 20A DC power supplies of the magnet control system. The filters were cleaned on the demineralised water circuits. The oil of the diffusion pumps was changed. On the cryogenics, warm nitrogen at 343 K was circulated in the cold box to regenerate the filters and the heat exchangers. The coalescing filters have been replaced at the inlet of both the turbines and the lubricant trapping unit. The active cha...

  12. MAGNET

    CERN Multimedia

    B. Curé

    2011-01-01

    The CMS magnet has been running steadily and smoothly since the summer, with no detected flaw. The magnet instrumentation is entirely operational and all the parameters are at their nominal values. Three power cuts on the electrical network affected the magnet run in the past five months, with no impact on the data-taking as the accelerator was also affected at the same time. On 22nd June, a thunderstorm caused a power glitch on the service electrical network. The primary water cooling at Point 5 was stopped. Despite a quick restart of the water cooling, the inlet temperature of the demineralised water on the busbar cooling circuit increased by 5 °C, up to 23.3 °C. It was kept below the threshold of 27 °C by switching off other cooling circuits to avoid the trigger of a slow dump of the magnet. The cold box of the cryogenics also stopped. Part of the spare liquid helium volume was used to maintain the cooling of the magnet at 4.5 K. The operators of the cryogenics quickly restarted ...

  13. MAGNET

    CERN Multimedia

    B. Curé

    2013-01-01

      The magnet was operated without any problem until the end of the LHC run in February 2013, apart from a CERN-wide power glitch on 10 January 2013 that affected the CMS refrigerator, causing a ramp down to 2 T in order to reconnect the coldbox. Another CERN-wide power glitch on 15 January 2013 didn’t affect the magnet subsystems, the cryoplant or the power converter. At the end of the magnet run, the reconnection of the coldbox at 2.5 T was tested. The process will be updated, in particular the parameters of some PID valve controllers. The helium flow of the current leads was reduced but only for a few seconds. The exercise will be repeated with the revised parameters to validate the automatic reconnection process of the coldbox. During LS1, the water-cooling services will be reduced and many interventions are planned on the electrical services. Therefore, the magnet cryogenics and subsystems will be stopped for several months, and the magnet cannot be kept cold. In order to avoid unc...

  14. Magnetic BaFe{sub 12}O{sub 19} nanofiber filter for effective separation of Fe{sub 3}O{sub 4} nanoparticles and removal of arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Byun, Jeehye; Patel, Hasmukh A.; Yavuz, Cafer T., E-mail: yavuz@kaist.ac.kr [Korea Advanced Institute of Science and Technology (KAIST), Graduate School of EEWS (Korea, Republic of)

    2014-12-15

    Magnetic nanoparticles are promising in applications where magnetic separation is intended, although material losses via leaching mechanisms are often inevitable. Magnetic separations with widely available permanent magnets can effectively trap particles, leading to a complete removal of used or waste particles. In this report, we first demonstrate the synthesis of the thinnest (112.716.4nm) and most magnetic (71.96emug{sup ?1}) barium hexaferrite (BaFe{sub 12}O{sub 19}, BHFfridge magnet) via an organic solvent-free electrospinning procedure. When the fibers are then packed into a column, they clearly remove 12nm magnetite (Fe{sub 3}O{sub 4}) nanoparticles quantitatively. The same BHF cartridge also removes more than 99.9% As-treated magnetite nanoparticles at capacities up to 70 times of its weight. As a result, one liter of 150?gL{sup ?1} As-contaminated water can be purified rapidly at a material cost of less than 2 US cents.

  15. MAGNET

    CERN Multimedia

    B. Curé

    2011-01-01

    The magnet ran smoothly in the last few months until a fast dump occurred on 9th May 2011. Fortunately, this occurred in the afternoon of the first day of the technical stop. The fast dump was due to a valve position controller that caused the sudden closure of a valve. This valve is used to regulate the helium flow on one of the two current leads, which electrically connects the coil at 4.5 K to the busbars at room temperature. With no helium flow on the lead, the voltage drop and the temperatures across the leads increase up to the defined thresholds, triggering a fast dump through the Magnet Safety System (MSS). The automatic reaction triggered by the MSS worked properly. The helium release was limited as the pressure rise was just at the limit of the safety valve opening pressure. The average temperature of the magnet reached 72 K. It took four days to recover the temperature and refill the helium volumes. The faulty valve controller was replaced by a spare one before the magnet ramp-up resumed....

  16. Electrostatic separator and mass separation

    International Nuclear Information System (INIS)

    Present performance of KEK electrostatic separator (Mark I) and the results of mass separation test using this separator and described. Maximum voltage of 900 kV was obtained with the 3 m separator and of 800 kV with the 9 m separator across the electrode spacing of 10 cm. Mass separation test using the 9 m separator was attempted at the bubble chamber beam Kl, and mass separation between pion and proton was achieved at the momentum of 3.5 GeV/c and 2 GeV/c. Separation ratio of -- 3.6 between pion and proton was obtained. The relative kaon yields were enriched from -- 1/200 to -- 1/15 at the mass slit when the separator was tuned at the momentum of 3.5 GeV/c. (auth.)

  17. Magnetic Field

    DEFF Research Database (Denmark)

    Olsen, Nils

    Earth by time-varying external fields. These sources have their specific characteristics in terms of spatial and temporal variations, and their proper separation, based on magnetic measurements, is a major challenge. Such a separation is a prerequisite for remote sensing by means of magnetic field...

  18. MAGNET

    CERN Multimedia

    Benoit Curé

    2010-01-01

    The magnet worked very well at 3.8 T as expected, despite a technical issue that manifested twice in the cryogenics since June. All the other magnet sub-systems worked without flaw. The issue in the cryogenics was with the cold box: it could be observed that the cold box was getting progressively blocked, due to some residual humidity and air accumulating in the first thermal exchanger and in the adsorber at 65 K. This was later confirmed by the analysis during the regeneration phases. An increase in the temperature difference between the helium inlet and outlet across the heat exchanger and a pressure drop increase on the filter of the adsorber were observed. The consequence was a reduction of the helium flow, first compensated by the automatic opening of the regulation valves. But once they were fully opened, the flow and refrigeration power reduced as a consequence. In such a situation, the liquid helium level in the helium Dewar decreased, eventually causing a ramp down of the magnet current and a field...

  19. MAGNET

    CERN Multimedia

    Benoit Curé.

    The magnet operation restarted end of June this year. Quick routine checks of the magnet sub-systems were performed at low current before starting the ramps up to higher field. It appeared clearly that the end of the field ramp down to zero was too long to be compatible with the detector commissioning and operations plans. It was decided to perform an upgrade to keep the ramp down from 3.8T to zero within 4 hours. On July 10th, when a field of 1.5T was reached, small movements were observed in the forward region support table and it was decided to fix this problem before going to higher field. At the end of July the ramps could be resumed. On July 28th, the field was at 3.8T and the summer CRAFT exercise could start. This run in August went smoothly until a general CERN wide power cut took place on August 3rd, due to an insulation fault on the high voltage network outside point 5. It affected the magnet powering electrical circuit, as it caused the opening of the main circuit breakers, resulting in a fast du...

  20. MAGNET

    CERN Multimedia

    B. Curé

    2013-01-01

    The magnet is fully stopped and at room temperature. The maintenance works and consolidation activities on the magnet sub-systems are progressing. To consolidate the cryogenic installation, two redundant helium compressors will be installed as ‘hot spares’, to avoid the risk of a magnet downtime in case of a major failure of a compressor unit during operation. The screw compressors, their motors, the mechanical couplings and the concrete blocks are already available and stored at P5. The metallic structure used to access the existing compressors in SH5 will be modified to allow the installation of the two redundant ones. The plan is to finish the installation and commissioning of the hot spare compressors before the summer 2014. In the meantime, a bypass on the high-pressure helium piping will be installed for the connection of a helium drier unit later during the Long Shutdown 1, keeping this installation out of the schedule critical path. A proposal is now being prepared for the con...

  1. MAGNET

    CERN Multimedia

    B. Curé

    MAGNET During the winter shutdown, the magnet subsystems went through a full maintenance. The magnet was successfully warmed up to room temperature beginning of December 2008. The vacuum was broken later on by injecting nitrogen at a pressure just above one atmosphere inside the vacuum tank. This was necessary both to prevent any accidental humidity ingress, and to allow for a modification of the vacuum gauges on the vacuum tank and maintenance of the diffusion pumps. The vacuum gauges had to be changed, because of erratic variations on the measurements, causing spurious alarms. The new type of vacuum gauges has been used in similar conditions on the other LHC experiments and without problems. They are shielded against the stray field. The lubricants of the primary and diffusion pumps have been changed. Several minor modifications were also carried out on the equipment in the service cavern, with the aim to ease the maintenance and to allow possible intervention during operation. Spare sensors have been bough...

  2. Low-temperature magnetization step and its training effects in phase-separated La0.5Ca0.5MnO3

    International Nuclear Information System (INIS)

    We observed a magnetization step accompanied by a metal-insulator transition around 75 K in La0.5Ca0.5MnO3. Repeating measurements under the same condition weaken the magnetization step and enhance the resistance at low temperature. The decayed magnetization step reappears after annealing the sample at high temperature or cooling it under a magnetic field. The low-temperature magnetization step can be attributed to the melting of the overcooled ferromagnetic fragments and its training effect may be related to structure distortions at the interfaces between the ferromagnetic and charge-ordered phases in the investigated system. (author)

  3. Electronic phase separation in La sub 1 sub . sub 2 Sr sub 1 sub . sub 8 Mn sub 2 O sub 7 observed by sup 5 sup 5 Mn nuclear magnetic resonance

    CERN Document Server

    Shimizu, K; Renard, J P; Pevcolevschi, A

    2003-01-01

    A single crystal of perovskite bilayer manganite La sub 1 sub . sub 2 Sr sub 1 sub . sub 8 Mn sub 2 O sub 7 has been studied by the sup 5 sup 5 Mn NMR technique. The observed spectra at 4.2 K in zero external magnetic field are broad and spread in the frequency range 310-480 MHz. The shape of the spectrum depends strongly on the rf radiation field for exciting and refocusing a spin-echo signal. In external magnetic fields up to 1.75 T, signals arising from both metallic and insulating phases are observed, which is an evidence of the electronic phase separation. (author)

  4. MAGNET

    CERN Multimedia

    Benoit Curé

    The magnet subsystems resumed operation early this spring. The vacuum pumping was restarted mid March, and the cryogenic power plant was restarted on March 30th. Three and a half weeks later, the magnet was at 4.5 K. The vacuum pumping system is performing well. One of the newly installed vacuum gauges had to be replaced at the end of the cool-down phase, as the values indicated were not coherent with the other pressure measurements. The correction had to be implemented quickly to be sure no helium leak could be at the origin of this anomaly. The pressure measurements have been stable and coherent since the change. The cryogenics worked well, and the cool-down went quite smoothly, without any particular difficulty. The automated start of the turbines had to be fine-tuned to get a smooth transition, as it was observed that the cooling power delivered by the turbines was slightly higher than needed, causing the cold box to stop automatically. This had no consequence as the cold box safety system acts to keep ...

  5. MAGNET

    CERN Multimedia

    B. Curé

    During the winter shutdown, the magnet subsystems went through a full maintenance. The magnet was successfully warmed up to room temperature beginning of December 2008. The vacuum was broken later on by injecting nitrogen at a pressure just above one atmosphere inside the vacuum tank. This was necessary both to prevent any accidental humidity ingress, and to allow for a modification of the vacuum gauges on the vacuum tank and maintenance of the diffusion pumps. The vacuum gauges had to be changed, because of erratic variations on the measurements, causing spurious alarms. The new type of vacuum gauges has been used in similar conditions on the other LHC experiments and without problems. They are shielded against the stray field. The lubricants of the primary and diffusion pumps have been changed. Several minor modifications were also carried out on the equipment in the service cavern, with the aim to ease the maintenance and to allow possible intervention during operation. Spare sensors have been bought. Th...

  6. Superposition of DC magnetic fields by cascading multiple magnets in magnetic loops

    Science.gov (United States)

    Sun, Fei; He, Sailing

    2015-09-01

    A novel method that can effectively collect the DC magnetic field produced by multiple separated magnets is proposed. With the proposed idea of a magnetic loop, the DC magnetic field produced by these separated magnets can be effectively superimposed together. The separated magnets can be cascaded in series or in parallel. A novel nested magnetic loop is also proposed to achieve a higher DC magnetic field in the common air region without increasing the DC magnetic field in each magnetic loop. The magnetic loop can be made by a magnetic hose, which is designed by transformation optics and can be realized by the combination of super-conductors and ferromagnetic materials.

  7. Environmentally-friendly oxygen-free roasting/wet magnetic separation technology for in situ recycling cobalt, lithium carbonate and graphite from spent LiCoO2/graphite lithium batteries.

    Science.gov (United States)

    Li, Jia; Wang, Guangxu; Xu, Zhenming

    2016-01-25

    The definite aim of the present paper is to present some novel methods that use oxygen-free roasting and wet magnetic separation to in situ recycle of cobalt, Lithium Carbonate and Graphite from mixed electrode materials. The in situ recycling means to change waste into resources by its own components, which is an idea of "waste+waste→resources." After mechanical scraping the mixed electrode materials enrich powders of LiCoO2 and graphite. The possible reaction between LiCoO2 and graphite was obtained by thermodynamic analysis. The feasibility of the reaction at high temperature was studied with the simultaneous thermogravimetry analysis under standard atmospheric pressure. Then the oxygen-free roasting/wet magnetic separation method was used to transfer the low added value mixed electrode materials to high added value products. The results indicated that, through the serious technologies of oxygen-free roasting and wet magnetic separation, mixture materials consist with LiCoO2 and graphite powders are transferred to the individual products of cobalt, Lithium Carbonate and Graphite. Because there is not any chemical solution added in the process, the cost of treating secondary pollution can be saved. This study provides a theoretical basis for industrial-scale recycling resources from spent LIBs. PMID:26448495

  8. Battery separators.

    Science.gov (United States)

    Arora, Pankaj; Zhang, Zhengming John

    2004-10-01

    The ideal battery separator would be infinitesimally thin, offer no resistance to ionic transport in electrolytes, provide infinite resistance to electronic conductivity for isolation of electrodes, be highly tortuous to prevent dendritic growths, and be inert to chemical reactions. Unfortunately, in the real world the ideal case does not exist. Real world separators are electronically insulating membranes whose ionic resistivity is brought to the desired range by manipulating the membranes thickness and porosity. It is clear that no single separator satisfies all the needs of battery designers, and compromises have to be made. It is ultimately the application that decides which separator is most suitable. We hope that this paper will be a useful tool and will help the battery manufacturers in selecting the most appropriate separators for their batteries and respective applications. The information provided is purely technical and does not include other very important parameters, such as cost of production, availability, and long-term stability. There has been a continued demand for thinner battery separators to increase battery power and capacity. This has been especially true for lithiumion batteries used in portable electronics. However, it is very important to ensure the continued safety of batteries, and this is where the role of the separator is greatest. Thus, it is essential to optimize all the components of battery to improve the performance while maintaining the safety of these cells. Separator manufacturers should work along with the battery manufacturers to create the next generation of batteries with increased reliability and performance, but always keeping safety in mind. This paper has attempted to present a comprehensive review of literature on separators used in various batteries. It is evident that a wide variety of separators are available and that they are critical components in batteries. In many cases, the separator is one of the major factors limiting the life and/or performance of batteries. Consequently, development of new improved separators would be very beneficial for the advanced high capacity batteries. PMID:15669158

  9. Optics of mass separator I

    International Nuclear Information System (INIS)

    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

  10. Optics of mass separator I

    Energy Technology Data Exchange (ETDEWEB)

    Balestrini, S.J.

    1981-07-01

    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.

  11. MAGNET

    CERN Multimedia

    B. Curé

    The first phase of the commissioning ended in August by a triggered fast dump at 3T. All parameters were nominal, and the temperature recovery down to 4.5K was carried out in two days by the cryogenics. In September, series of ramps were achieved up to 3 and finally 3.8T, while checking thoroughly the detectors in the forward region, measuring any movement of and around the HF. After the incident of the LHC accelerator on September 19th, corrective actions could be undertaken in the forward region. When all these displacements were fully characterized and repetitive, with no sign of increments in displacement at each field ramp, it was possible to start the CRAFT, Cosmic Run at Four Tesla (which was in fact at 3.8T). The magnet was ramped up to 18.16kA and the 3 week run went smoothly, with only 4 interruptions: due to the VIP visits on 21st October during the LHC inauguration day; a water leak on the cooling demineralized water circuit, about 1 l/min, that triggered a stop of the cooling pumps, and resulte...

  12. MAGNET

    CERN Multimedia

    Benoit Cur

    The cooling down to the nominal temperature of 4.5 K was achieved at the beginning of August, in conjunction with the completion of the installation work of the connection between the power lines and the coil current leads. The temperature gradient on the first exchanger of the cold box is now kept within the nominal range. A leak of lubricant on a gasket of the helium compressor station installed at the surface was observed and several corrective actions were necessary to bring the situation back to normal. The compressor had to be refilled with lubricant and a regeneration of the filters and adsorbers was necessary. The coil cool down was resumed successfully, and the cryogenics is running since then with all parameters being nominal. Preliminary tests of the 20kA coil power supply were done earlier at full current through the discharge lines into the dump resistors, and with the powering busbars from USC5 to UXC5 without the magnet connected. On Monday evening August 25th, at 8pm, the final commissionin...

  13. Magnetic

    Science.gov (United States)

    Aboud, Essam; El-Masry, Nabil; Qaddah, Atef; Alqahtani, Faisal; Moufti, Mohammed R. H.

    2015-06-01

    The Rahat volcanic field represents one of the widely distributed Cenozoic volcanic fields across the western regions of the Arabian Peninsula. Its human significance stems from the fact that its northern fringes, where the historical eruption of 1256 A.D. took place, are very close to the holy city of Al-Madinah Al-Monawarah. In the present work, we analyzed aeromagnetic data from the northern part of Rahat volcanic field as well as carried out a ground gravity survey. A joint interpretation and inversion of gravity and magnetic data were used to estimate the thickness of the lava flows, delineate the subsurface structures of the study area, and estimate the depth to basement using various geophysical methods, such as Tilt Derivative, Euler Deconvolution and 2D modeling inversion. Results indicated that the thickness of the lava flows in the study area ranges between 100 m (above Sea Level) at the eastern and western boundaries of Rahat Volcanic field and getting deeper at the middle as 300-500 m. It also showed that, major structural trend is in the NW direction (Red Sea trend) with some minor trends in EW direction.

  14. MAGNET

    CERN Multimedia

    Benoit Curé

    2013-01-01

    Maintenance work and consolidation activities on the magnet cryogenics and its power distribution are progressing according to the schedules. The manufacturing of the two new helium compressor frame units has started. The frame units support the valves, all the sensors and the compressors with their motors. This activity is subcontracted. The final installation and the commissioning at CERN are scheduled for March–April 2014. The overhauls of existing cryogenics equipment (compressors, motors) are in progress. The reassembly of the components shall start in early 2014. The helium drier, to be installed on the high-pressure helium piping, has been ordered and will be delivered in the first trimester of 2014. The power distribution for the helium compressors in SH5 on the 3.3kV network is progressing. The 3.3kV switches, between each compressor and its hot spare compressor, are being installed, together with the power cables for the new compressors. The 3.3kV electrical switchboards in SE5 will ...

  15. Novel magnetic flux penetration in overdoped La2-xSrxCuO4 single crystals: macroscopic phase separation in a heavily overdoped regime

    International Nuclear Information System (INIS)

    Superconducting diamagnetic properties and magnetic flux penetration have been comparatively investigated on two La2-xSrxCuO4 single crystals: one underdoped (x=0.092) and the other overdoped (x = 0.24). Both samples have only a single transition when the external field is low. While when a relatively high external field is applied, a large distinction between these two samples is observed: there is only one transition for the underdoped sample, but an unexpected second transition appears for the overdoped sample. Further investigation on the overdoped sample shows that it has a novel property of magnetic flux penetration, which is characterized by the vanishing of the usual central peak near zero field on the magnetization hysteresis loops. This easy penetration of magnetic flux can be understood in the picture of percolative superconductivity due to the inhomogeneous electronic state in a heavily overdoped regime. (author)

  16. Field dependence of the electronic phase separation in Pr0.67Ca0.33MnO3 by small angle magnetic neutron scattering

    CERN Document Server

    Mercone, S; Martin, C; Simon, C; Saurel, D; Brulet, A; Mercone, Silvana; Hardy, Vincent; Martin, Christine; Simon, Charles; Saurel, Damien; Brulet, Annie

    2003-01-01

    We have studied by small angle neutron scattering the evolution induced by the application of magnetic field of the coexistence of ferromagnetism (F) and antiferromagnetism (AF) in a crystal of Pr$_{0.67}$Ca$_{0.33}$MnO$_3$. The results are compared to magnetic measurements which provide the evolution of the ferromagnetic fraction. These results show that the growth of the ferromagnetic phase corresponds to an increase of the thickness of the ferromagnetic ''cabbage'' sheets.

  17. Separation technologies

    International Nuclear Information System (INIS)

    The chemical process industries (CPI), including the petroleum and chemical industries, consume the energy equivalent of about three million barrels of crude oil per day - this translates to 27% of industrial energy consumption in the U.S. (excluding raw materials). This paper discusses separation processes which recover and purify products account for over 40% of CPI energy demand. Separation processes include removal of impurities from raw materials, of products and by-products from reactor crude, and of containments from water and air effluents. Examples of such separation processes include absorption, adsorption, ion exchange, chromatography, crystallization, distillation, drying, electrodialysis, electrolytic processes, evaporation, extraction, filtration, flotation, membranes, and stripping. Because distillation is the most widely used separation process, we will focus on it and its alternatives, adsorption, and membrane processes

  18. Isotopic separation

    International Nuclear Information System (INIS)

    Isotopic species in an isotopic mixture including a first species having a first isotope and a second species having a second isotope are separated by selectively exciting the first species in preference to the second species and then reacting the selectively excited first species with an additional preselected radiation, an electron or another chemical species so as to form a product having a mass different from the original species and separating the product from the balance of the mixture in a centrifugal separating device such as centrifuge or aerodynamic nozzle. In the centrifuge the isotopic mixture is passed into a rotor where it is irradiated through a window. Heavier and lighter components can be withdrawn. The irradiated mixture experiences a large centrifugal force and is separated in a deflection area into lighter and heavier components. (UK)

  19. Stereoisomers Separation

    Science.gov (United States)

    Wieczorek, Piotr

    The use of capillary electrophoresis for enantiomer separation and optical purity determination is presented. The contents start with basic information about the nature of stereoizomers and the mechanism of enantioseparation using capillary electrophoresis techniques. The molecules to be separated show identical chemical structure and electrochemical behavior. Therefore, the chiral recognition of enantiomers is possible only by bonding to chiral selector and the separation based on very small differences in complexation energies of diastereomer complexes formed. This method is useful for this purpose due to the fact that different compounds can be used as chiral selectors. The mostly used chiral selectors like cyclodextrins, crown ethers, chiral surfactants, macrocyclic antibiotics, transition metal complexes, natural, and synthetic polymers and their application for this purpose is also discussed. Finally, examples of practical applications of electromigration techniques for enantiomers separation and determination are presented.

  20. Isotopic separation

    International Nuclear Information System (INIS)

    A method is described for separating isotopes in which photo-excitation of selected isotope species is used together with the reaction of the excited species with postive ions of predetermined ionization energy, other excited species, or free electrons to produce ions or ion fragments of the selected species. Ions and electrons are produced by an electrical discharge, and separation is achieved through radial ambipolar diffusion, electrostatic techniques, or magnetohydrodynamic methods

  1. Isotopic separation

    International Nuclear Information System (INIS)

    A method is described for separating isotopes in an isotopic mixture, in which photo-excitation of selected isotopic species is utilized in conjunction with reaction of the excited species with positive ions of predetermined ionization energy, other excited species or free electrons to produce ions or ion fragments of the selected species. Ions and electrons are produced by an electrical discharge, and separation is achieved through radial ambipolar diffusion, electrostatic or magnetohydrodynamic techniques. (author)

  2. Separations chemistry

    International Nuclear Information System (INIS)

    Results of studies on the photochemistry of aqueous Pu solutions and the stability of iodine in liquid and gaseous CO2 are reported. Progress is reported in studies on: the preparation of macroporous bodies filled with oxides and sulfides to be used as adsorbents; the beneficiation of photographic wastes; the anion exchange adsorption of transition elements from thiosulfate solutions; advanced filtration applications of energy significance; high-resolution separations; and, the examination of the separation agents, octylphenylphosphoric acid (OPPA) and trihexyl phosphate (THP)

  3. Anomalies of magnetic, electric and elastic properties of Sm1-xSrxMnO3 manganites due to phase separation

    International Nuclear Information System (INIS)

    Colossal magnetoresistance (MR) and giant negative volume magnetostriction (MS) have been observed in the Curie temperature region of Sm1-xSrxMnO3 manganites for x=0.33 compounds containing ferromagnetic (FM) and A-type antiferromagnetic (AFM) clusters, and for x=0.4 and 0.45 containing FM and both types of AFM clusters (A type and charge ordering (CO) type). For x=0.33 magnetization, MR and MS increase smoothly with magnetic field increase and saturation of MR and MS is not achieved. For x=0.4 and 0.45 the sharp jump of magnetization, MR and MS takes place at HC1C2, and saturation is achieved at H>HC2. We believe that the reason for colossal MR and giant MS being observed in the investigated compounds is the increase of FM phase volume under magnetic field action. For x=0.33 this increase is smooth because it arises from the FM phase 'sprouting' on FM layers of the A-type AFM phase. For x=0.4 and 0.45 the increase of FM part volume arises from CO clusters with CE type of AFM structure too. In this case, CO clusters are completely transformed to the FM state. This transition is accompanied by crystal structure reconstruction that is manifested in both the temperature and magnetic field dependences of the anisotropic MS

  4. Observation of dynamical spin-dependent electron interactions and screening in magnetic transitions via core-level multiplet-energy separations.

    Czech Academy of Sciences Publication Activity Database

    Tober, E.D.; Palomares, F.J.; Ynzunza, R.X.; Denecke, R.; Morais, J.; Liesegang, J.; Hussain, Z.; Shick, Alexander; Pickett, W. E.; Fadley, C. S.

    2013-01-01

    Ro?. 189, AUG (2013), s. 152-156. ISSN 0368-2048 Institutional support: RVO:68378271 Keywords : photoelectron spectroscopy * electronic structure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.552, year: 2013 http://www.sciencedirect.com/science/article/pii/S0368204812001880

  5. Studies in matter antimatter separation and in the origin of lunar magnetism. Annual progress report, 1 Sep 1974--31 Aug 1975

    International Nuclear Information System (INIS)

    A progress report covering lunar and planetary research is introduced. Data cover lunar ionospheric models, lunar and planetary geology, and lunar magnetism. Wind tunnel simulations of Mars aeolian problems and a comparative study of basaltic analogs of Lunar and Martial volcanic features was discussed

  6. Isotope separation

    International Nuclear Information System (INIS)

    A method and apparatus is described for separating gas molecules containing one isotope of an element from gas molecules containing other isotopes of the same element in which all of the molecules of the gas are at the same electronic state in their ground state. Gas molecules in a gas stream containing one of the isotopes are selectively excited to a different electronic state while leaving the other gas molecules in their original ground state. Gas molecules containing one of the isotopes are then deflected from the other gas molecules in the stream and thus physically separated

  7. Separation of PCR-ready DNA from dairy products using magnetic hydrophilic microspheres and poly(ethylene glycol)-NaCl water solutions

    Energy Technology Data Exchange (ETDEWEB)

    Rittich, Bohuslav [Masaryk University, Faculty of Science, Institute of Experimental Biology, Tvrdeho 14, CZ-611 37 Brno (Czech Republic); Brno University of Technology, Faculty of Chemistry, Institute of Food Science and Biotechnology, Purkynova 464/118, CZ-612 00 Brno (Czech Republic)], E-mail: rittich@sci.muni.cz; Spanova, Alena [Masaryk University, Faculty of Science, Institute of Experimental Biology, Tvrdeho 14, CZ-611 37 Brno (Czech Republic); Brno University of Technology, Faculty of Chemistry, Institute of Food Science and Biotechnology, Purkynova 464/118, CZ-612 00 Brno (Czech Republic); Salek, Petr [Brno University of Technology, Faculty of Chemistry, Institute of Food Science and Biotechnology, Purkynova 464/118, CZ-612 00 Brno (Czech Republic); Nemcova, Petra [Masaryk University, Faculty of Science, Institute of Experimental Biology, Tvrdeho 14, CZ-611 37 Brno (Czech Republic); Trachtova, Stepanka [Brno University of Technology, Faculty of Chemistry, Institute of Food Science and Biotechnology, Purkynova 464/118, CZ-612 00 Brno (Czech Republic); Horak, Daniel [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2, CZ-162 06 Prague (Czech Republic)

    2009-05-15

    Carboxyl group-containing magnetic nonporous poly(2-hydroxyethyl methacrylate-co-glycidyl methacrylate) (P(HEMA-co-GMA)) and magnetic glass microspheres were used for the isolation of bacterial DNA. P(HEMA-co-GMA) microspheres were prepared by the dispersion polymerization in toluene/2-methylpropan-1-ol mixture in the presence of magnetite nanoparticles obtained by coprecipitation of Fe(II) and Fe(III) salts with ammonium hydroxide. Carboxyl groups were then introduced by oxidation of the microspheres with potassium permanganate. The most extensive DNA recovery was achieved at PEG 6000 concentrations of 12% or 16% and 2 M NaCl. The method proposed was used for bacterial DNA isolation from different dairy products containing Bifidobacterium and Lactobacillus cells. The presence of target DNA and the quality of isolated DNA were checked by polymerase chain reaction (PCR) amplification with specific primers.

  8. The Swarm End-to-End mission simulator study: A demonstration of separating the various contributions to Earth's magnetic field using synthetic data

    DEFF Research Database (Denmark)

    Olsen, Nils; Haagmans, R.; Sabaka, T.J.; Kuvshinov, A.; Maus, S.; Purucker, M.E.; Rother, M.; Lesur, V.; Mandea, M.

    2006-01-01

    Swarm, a satellite constellation to measure Earth's magnetic field with unpreceded accuracy, has been selected by ESA for launch in 2009. The mission will provide the best ever survey of the geomagnetic field and its temporal evolution, in order to gain new insights into the Earth system by improving our understanding of the Earth's interior and climate. An End-to-End mission performance simulation was carried out during Phase A of the mission, with the aim of analyzing the key system requiremen...

  9. Tris(2-Aminoethyl)Amine-Functionalized Fe3O4 Magnetic Nanoparticles as a Selective Sorbent for Separation of Silver and Gold Ions in Different pHs

    OpenAIRE

    Hamid Reza Lotfi Zadeh Zhad; Forouzan Aboufazeli; Omid Sadeghi; Vahid Amani; Ezzatollah Najafi; Najmeh Tavassoli

    2013-01-01

    The usage of tris(2-aminoethyl)amine-functionalized Fe3O4 nanoparticles as a novel magnetic sorbent for rapid extraction, preconcentration, and determination of trace amounts of silver and gold ions was investigated. The optimum conditions for sample pH, eluent parameters (type, concentration and volume) were obtained. The effect of various cationic interferences on the adsorption of silver and gold was evaluated. The analytical efficiency values of both silver and gold ions were higher than ...

  10. Nuclear magnetic resonance and liquid chromatography-mass spectrometry combined with an incompleted separation strategy for identifying the natural products in crude extract

    International Nuclear Information System (INIS)

    NMR and LC-MS combined with an incompleted separation strategy were proposed to the simultaneous structure identification of natural products in crude extracts, and a novel method termed as NMR/LC-MS parallel dynamic spectroscopy (NMR/LC-MS PDS) was developed to discover the intrinsic correlation between retention time (Rt), mass/charge (m/z) and chemical shift (?) data of the same constituent from mixture spectra by the co-analysis of parallelly visualized multispectroscopic datasets from LC-MS and 1H NMR. The extracted ion chromatogram (XIC) and 1H NMR signals deriving from the same individual constituent were correlated through fraction ranges and intensity changing profiles in NMR/LC-MS PDS spectrum due to the signal amplitude co-variation resulted from the concentration variation of constituents in a series of incompletely separated fractions. NMR/LC-MS PDS was applied to identify 12 constituents in an active herbal extract including flavonol glycosides, which was separated into a series of fractions by flash column chromatography. The complementary spectral information of the same individual constituent in the crude extract was discovered simultaneously from mixture spectra. Especially, two groups of co-eluted isomers were identified successfully. The results demonstrated that NMR/LC-MS PDS combined with the incompleted separation strategy achieved the similar function of on-line LC-NMR-MS analysis in off-line mode and had the potential for simplifying and accelerating the analytical routes for structure identification of constituents in herbs or their active extracts

  11. Nuclear magnetic resonance and liquid chromatography-mass spectrometry combined with an incompleted separation strategy for identifying the natural products in crude extract

    Energy Technology Data Exchange (ETDEWEB)

    Dai Dongmei; He Jiuming [Key Laboratory of Bioactive Substances and Resource Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, 1 Xian Nong Tan Street, Beijing 100050 (China); Sun Ruixiang [Institute of Computing Technology, Chinese Academy of Sciences, Beijing 100080 (China); Zhang Ruiping [Key Laboratory of Bioactive Substances and Resource Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, 1 Xian Nong Tan Street, Beijing 100050 (China); Aisa, Haji Akber [Xinjiang Technological Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011 (China); Abliz, Zeper [Key Laboratory of Bioactive Substances and Resource Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, 1 Xian Nong Tan Street, Beijing 100050 (China)], E-mail: zeper@imm.ac.cn

    2009-01-26

    NMR and LC-MS combined with an incompleted separation strategy were proposed to the simultaneous structure identification of natural products in crude extracts, and a novel method termed as NMR/LC-MS parallel dynamic spectroscopy (NMR/LC-MS PDS) was developed to discover the intrinsic correlation between retention time (Rt), mass/charge (m/z) and chemical shift ({delta}) data of the same constituent from mixture spectra by the co-analysis of parallelly visualized multispectroscopic datasets from LC-MS and {sup 1}H NMR. The extracted ion chromatogram (XIC) and {sup 1}H NMR signals deriving from the same individual constituent were correlated through fraction ranges and intensity changing profiles in NMR/LC-MS PDS spectrum due to the signal amplitude co-variation resulted from the concentration variation of constituents in a series of incompletely separated fractions. NMR/LC-MS PDS was applied to identify 12 constituents in an active herbal extract including flavonol glycosides, which was separated into a series of fractions by flash column chromatography. The complementary spectral information of the same individual constituent in the crude extract was discovered simultaneously from mixture spectra. Especially, two groups of co-eluted isomers were identified successfully. The results demonstrated that NMR/LC-MS PDS combined with the incompleted separation strategy achieved the similar function of on-line LC-NMR-MS analysis in off-line mode and had the potential for simplifying and accelerating the analytical routes for structure identification of constituents in herbs or their active extracts.

  12. Magnetically separable ternary hybrid of ZnFe{sub 2}O{sub 4}Fe{sub 2}O{sub 3}Bi{sub 2}WO{sub 6} hollow nanospheres with enhanced visible photocatalytic property

    Energy Technology Data Exchange (ETDEWEB)

    Li, Junqi, E-mail: sfmlab@163.com; Liu, Zhenxing; Zhu, Zhenfeng

    2014-11-30

    Highlights: Ternary hybrid ZnFe{sub 2}O{sub 4}Fe{sub 2}O{sub 3}Bi{sub 2}WO{sub 6} hollow nanospheres were synthesized. Ternary hybrid sample exhibited highest performance than the others. The enhanced activity could be attributed to the cascade electron transfer. The photocatalyst could be separated by magnetic field. - Abstract: Magnetically separable ternary hybrid ZnFe{sub 2}O{sub 4}Fe{sub 2}O{sub 3}Bi{sub 2}WO{sub 6} hollow nanospheres were designed and synthesized by an effective three-step approach. Specifically, using phenolic formaldehyde microspheres (PFS) as template direct the sequential coating of ?-Fe{sub 2}O{sub 3}/ZnFe{sub 2}O{sub 4} layer and subsequent Bi{sub 2}WO{sub 6} layer via impregnating-calcination process. The photocatalytic activity under visible light irradiation is in the order of ZnFe{sub 2}O{sub 4}Fe{sub 2}O{sub 3}Bi{sub 2}WO{sub 6} > ZnFe{sub 2}O{sub 4}Bi{sub 2}WO{sub 6} > Bi{sub 2}WO{sub 6} > ZnFe{sub 2}O{sub 4}Fe{sub 2}O{sub 3} > ZnFe{sub 2}O{sub 4}. The enhanced activity could be attributed to the cascade electron transfer from ZnFe{sub 2}O{sub 4} to ?-Fe{sub 2}O{sub 3} then to Bi{sub 2}WO{sub 6} through the interfacial potential gradient in the ternary hybrid conduction bands, which facilitate the charge separation and retard the charge pair recombination. Furthermore, the ternary hybrid ZnFe{sub 2}O{sub 4}Fe{sub 2}O{sub 3}Bi{sub 2}WO{sub 6} hollow nanospheres could be conveniently separated by using an external magnetic field, and be chemically and optically stable after several repetitive tests. The study also provides a general and effective method in the composite hollow nanomaterials with sound heterojunctions that may show a variety of applications.

  13. Separation Logic

    DEFF Research Database (Denmark)

    Reynolds, John C.

    2002-01-01

    In joint work with Peter O'Hearn and others, based on early ideas of Burstall, we have developed an extension of Hoare logic that permits reasoning about low-level imperative programs that use shared mutable data structure. The simple imperative programming language is extended with commands (not expressions) for accessing and modifying shared structures, and for explicit allocation and deallocation of storage. Assertions are extended by introducing a "separating conjunction" that asserts that i...

  14. Synthesis of Superparamagnetic Core-Shell Structure Supported Pd Nanocatalysts for Catalytic Nitrite Reduction with Enhanced Activity, No Detection of Undesirable Product of Ammonium, and Easy Magnetic Separation Capability.

    Science.gov (United States)

    Sun, Wuzhu; Yang, Weiyi; Xu, Zhengchao; Li, Qi; Shang, Jian Ku

    2016-01-27

    Superparamagnetic nanocatalysts could minimize both the external and internal mass transport limitations and neutralize OH(-) produced in the reaction more effectively to enhance the catalytic nitrite reduction efficiency with the depressed product selectivity to undesirable ammonium, while possess an easy magnetic separation capability. However, commonly used qusi-monodispersed superparamagnetic Fe3O4 nanosphere is not suitable as catalyst support for nitrite reduction because it could reduce the catalytic reaction efficiency and the product selectivity to N2, and the iron leakage could bring secondary contamination to the treated water. In this study, protective shells of SiO2, polymethylacrylic acid, and carbon were introduced to synthesize Fe3O4@SiO2/Pd, Fe3O4@PMAA/Pd, and Fe3O4@C/Pd catalysts for catalytic nitrite reduction. It was found that SiO2 shell could provide the complete protection to Fe3O4 nanosphere core among these shells. Because of its good dispersion, dense structure, and complete protection to Fe3O4, the Fe3O4@SiO2/Pd catalyst demonstrated the highest catalytic nitrite reduction activity without the detection of NH4(+) produced. Due to this unique structure, the activity of Fe3O4@SiO2/Pd catalysts for nitrite reduction was found to be independent of the Pd nanoparticle size or shape, and their product selectivity was independent of the Pd nanoparticle size, shape, and content. Furthermore, their superparamagnetic nature and high saturation magnetization allowed their easy magnetic separation from treated water, and they also demonstrated a good stability during the subsequent recycling experiment. PMID:26709845

  15. The Swarm End-to-End mission simulator study: A demonstration of separating the various contributions to Earth's magnetic field using synthetic data

    DEFF Research Database (Denmark)

    Olsen, Nils; Haagmans, R.; Sabaka, T.J.; Kuvshinov, A.; Maus, S.; Purucker, M.E.; Rother, M.; Lesur, V.; Mandea, M.

    2006-01-01

    applied to the synthetic data to analyze various aspects of field recovery in relation to different number of satellites, different constellations and realistic noise sources. This paper gives an overview of the study activities, describes the generation of the synthetic data, and assesses the obtained...... science objectives of Swarm. In order to be able to use realistic parameters of the Earth's environment, the mission simulation starts at January 1, 1997 and lasts until re-entry of the lower satellites five years later. Synthetic magnetic field values were generated for all relevant contributions to...

  16. Microwave-enhanced synthesis of magnetic porous covalent triazine-based framework composites for fast separation of organic dye from aqueous solution

    International Nuclear Information System (INIS)

    Graphical abstract: - Abstract: A novel type of magnetic porous carbonaceous polymeric material, CTF/Fe2O3 composite (CTF = covalent triazine-based framework), has been synthesized by a facile microwave-enhanced high-temperature ionothermal method. By selecting ZnCl2 as a reaction medium and the Lewis acid catalyst, and choosing FeCl3.6H2O as an iron oxide precursor, a series of CTF/Fe2O3 composites with different ?-Fe2O3 contents has been prepared in 60 min. The resulting samples were characterized by the X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibration sample magnetometer (VSM), and N2 sorption-desorption isotherms. The obtained CTF/Fe2O3 composites exhibit high surface areas (930-1149 m2 g-1), and their saturation magnetizations at 300 K vary from 1.1 to 5.9 emu g-1, depending respectively on different Fe2O3 contents (6.43-12.43 wt%) in the CTF/Fe2O3 composites. The CTF/Fe2O3 composites were applied to remove organic dye from aqueous solution by selecting methyl orange as a model molecule, and both high adsorption capacity (291 mg g-1, corresponding to 0.889 mmol g-1) and fast adsorption kinetics (kads = 4.31 m2 mg-1 min-1) were observed.

  17. Separations sciences

    International Nuclear Information System (INIS)

    1,1,1,2,2,3,3-heptafluoro-7,7-dimethyl-4,6-octanedione (HFDMOD) is being studied for extracting cations. Methods and agents for separating actinides from U ore processing streams and fuel reprocessing wastes are being studied. Zinc in HEPA filters was found to increase penetration by alpha-active materials. Distribution data are given for the extraction of acetic acid by amines, of alkali metals by HDEHP and crown ethers, of Eu by DEHDECMP, and of alkali and alkaline-earth metals by HFDMOD. Removal of tritium from lithium by sorption on yttrium was studied

  18. Isotope separation

    International Nuclear Information System (INIS)

    A process for separating uranium isotopes is described which includes: preparing a volatile compound U-T, in which U is a mixture of uranium isotopes and T is a chemical moiety containing at least one organic or deuterated borohydride group, and which exhibits for at least one isotopic species thereof a fundamental, overtone or combination vibrational absorption excitation energy level at a frequency between 900 and 1100 cm-1; and irradiating the compound in the vapour phase with energy emitted by a radiation source at a frequency between 900 and 1100 cm-1 (e.g. a CO2 laser). (author)

  19. Magnetic Field

    DEFF Research Database (Denmark)

    Olsen, Nils

    2015-01-01

    he Earth has a large and complicated magnetic field, the major part of which is produced by a self-sustaining dynamo operating in the fluid outer core. Magnetic field observations provide one of the few tools for remote sensing the Earths deep interior, especially regarding the dynamics of the fluid flow at the top of the core. However, what is measured at or near the surface of the Earth is the superposition of the core field and fields caused by magnetized rocks in the Earths crust, by electric currents flowing in the ionosphere, magnetosphere, and oceans, and by currents induced in the Earth by time-varying external fields. These sources have their specific characteristics in terms of spatial and temporal variations, and their proper separation, based on magnetic measurements, is a major challenge. Such a separation is a prerequisite for remote sensing by means of magnetic field observations.

  20. Atomic lithium vapor laser isotope separation

    CERN Document Server

    Olivares, I E

    2002-01-01

    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)

  1. Microwave-enhanced synthesis of magnetic porous covalent triazine-based framework composites for fast separation of organic dye from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Wang; Liang Fei; Li Cun [Laboratory of Advanced Porous Materials, School of Chemistry and Chemical Engineering, Anhui University, 3rd Feixi Road, Hefei 230039, Anhui Province (China); Qiu Lingguang, E-mail: lgqiu@ahu.edu.cn [Laboratory of Advanced Porous Materials, School of Chemistry and Chemical Engineering, Anhui University, 3rd Feixi Road, Hefei 230039, Anhui Province (China); Yuan Yupeng; Peng Fumin; Jiang Xia; Xie Anjian; Shen Yuhua [Laboratory of Advanced Porous Materials, School of Chemistry and Chemical Engineering, Anhui University, 3rd Feixi Road, Hefei 230039, Anhui Province (China); Zhu Junfa [National Synchrocyclotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China)

    2011-02-28

    Graphical abstract: - Abstract: A novel type of magnetic porous carbonaceous polymeric material, CTF/Fe{sub 2}O{sub 3} composite (CTF = covalent triazine-based framework), has been synthesized by a facile microwave-enhanced high-temperature ionothermal method. By selecting ZnCl{sub 2} as a reaction medium and the Lewis acid catalyst, and choosing FeCl{sub 3}.6H{sub 2}O as an iron oxide precursor, a series of CTF/Fe{sub 2}O{sub 3} composites with different {gamma}-Fe{sub 2}O{sub 3} contents has been prepared in 60 min. The resulting samples were characterized by the X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibration sample magnetometer (VSM), and N{sub 2} sorption-desorption isotherms. The obtained CTF/Fe{sub 2}O{sub 3} composites exhibit high surface areas (930-1149 m{sup 2} g{sup -1}), and their saturation magnetizations at 300 K vary from 1.1 to 5.9 emu g{sup -1}, depending respectively on different Fe{sub 2}O{sub 3} contents (6.43-12.43 wt%) in the CTF/Fe{sub 2}O{sub 3} composites. The CTF/Fe{sub 2}O{sub 3} composites were applied to remove organic dye from aqueous solution by selecting methyl orange as a model molecule, and both high adsorption capacity (291 mg g{sup -1}, corresponding to 0.889 mmol g{sup -1}) and fast adsorption kinetics (k{sub ads} = 4.31 m{sup 2} mg{sup -1} min{sup -1}) were observed.

  2. Isotopomeric separation

    International Nuclear Information System (INIS)

    The labelling of molecules using stable or radioactive isotopes is an important task in particular for further use in biology and medicine. In this framework, tritiated and deuterated compounds are synthesized and the behaviour of deuterated molecules is studied using reversed phase polarities partition chromatography for a comparison with their protonated homologues. Neutral molecular compounds like benzene or toluene and others with ionizable groups such as aniline or diethyl-aniline and with carry a chromophore (aromatic cycle) are studied on several alkyls grafted silica. The retention times are proportional to the number of hydrogen atoms substituted by deuterium. A separation of diethyl-aniline isotopomers is performed for compounds deuterated even on the aromatic cycle, or on one of the ethyl groups carried by nitrogen, or on the whole molecule. A study has started on isotopomeric chiral molecules with deuterium fixed on the benzene cycle or on a methyl

  3. Multi-cycle recovery of lactoferrin and lactoperoxidase from crude whey using fimbriated high-capacity magnetic cation exchangers and a novel "rotor-stator" high-gradient magnetic separator.

    Science.gov (United States)

    Brown, Geoffrey N; Mller, Christine; Theodosiou, Eirini; Franzreb, Matthias; Thomas, Owen R T

    2013-06-01

    Cerium (IV) initiated "graft-from" polymerization reactions were employed to convert M-PVA magnetic particles into polyacrylic acid-fimbriated magnetic cation exchange supports displaying ultra-high binding capacity for basic target proteins. The modifications, which were performed at 25?mg and 2.5?g scales, delivered maximum binding capacities (Qmax ) for hen egg white lysozyme in excess of 320?mg?g(-1) , combined with sub-micromolar dissociation constants (0.45-0.69?m) and "tightness of binding" values greater than 49?L?g(-1) . Two batches of polyacrylic acid-fimbriated magnetic cation exchangers were combined to form a 5?g pooled batch exhibiting Qmax values for lysozyme, lactoferrin, and lactoperoxidase of 404, 585, and 685?mg?g(-1) , respectively. These magnetic cation exchangers were subsequently employed together with a newly designed "rotor-stator" type HGMF rig, in five sequential cycles of recovery of lactoferrin and lactoperoxidase from 2?L batches of a crude sweet bovine whey feedstock. Lactoferrin purification performance was observed to remain relatively constant from one HGMF cycle to the next over the five operating cycles, with yields between 40% and 49% combined with purification and concentration factors of 37- to 46-fold and 1.3- to 1.6-fold, respectively. The far superior multi-cycle HGMF performance seen here compared to that observed in our earlier studies can be directly attributed to the combined use of improved high capacity adsorbents and superior particle resuspension afforded by the new "rotor-stator" HGMS design. PMID:23335282

  4. Novel antibody/gold nanoparticle/magnetic nanoparticle nanocomposites for immunomagnetic separation and rapid colorimetric detection of Staphylococcus aureus in milk.

    Science.gov (United States)

    Sung, Yun Ju; Suk, Ho-Jun; Sung, Hwa Young; Li, Taihua; Poo, Haryoung; Kim, Min-Gon

    2013-05-15

    We demonstrated the new antibody/gold nanoparticle/magnetic nanoparticle nanocomposites (antibody/AuNP/MNPs) and their application in the detection of the foodborne pathogen, Staphylococcus aureus (S. aureus), in milk. The nanocomposites were synthesized by coating the MNPs with bovine serum albumin (BSA) then adsorbing the AuNPs and anti-S. aureus antibodies on their surface. Using the completed immunomagnetic nanostructures, S. aureus inoculated in the milk sample was captured and isolated from the medium using the permanent magnet. The nanoparticle-bound cells as well as the unbound cells in the supernatant were enumerated via surface plating to evaluate the target binding capacity of the nanocomposites. The capture efficiencies of the antibody/AuNP/MNPs were 96% and 78% for S. aureus in PBS and the milk sample respectively, which were significantly higher than those of the antibody-coupled MNPs without any AuNP. The captured cells were also applied to the selective filtration system to produce color signals that were used for the detection of the target pathogen. During the filtration, the cells bound to the antibody/AuNP/MNPs remained on the surface of the membrane filter while unbound nanoparticles passed through the uniform pores of the membrane. After the gold enhancement, the cells-particles complex resting on the membrane surface rendered a visible color, and the signal intensity became higher as the target cell concentration increased. The detection limits of this colorimetric sensor were 1.510(3) and 1.510(5)CFU for S. aureus in PBS and the milk sample respectively. This sensing mechanism also had the high specificity for S. aureus over the other pathogens such as Escherichia coli, Listeria monocytogenes, and Salmonella enterica. The assay required only 40min to obtain the results. With the use of the appropriate antibodies, our immunomagnetic nanocomposites-based detection strategy can provide an easy, convenient, and rapid sensing method for a wide range of pathogens. PMID:23370174

  5. Green synthesis of Pd/RGO/Fe3O4 nanocomposite using Withania coagulans leaf extract and its application as magnetically separable and reusable catalyst for the reduction of 4-nitrophenol.

    Science.gov (United States)

    Atarod, Monireh; Nasrollahzadeh, Mahmoud; Mohammad Sajadi, S

    2016-03-01

    A reduced graphene oxide (RGO)/Fe3O4 based nanocomposite with palladium nanoparticles (Pd NPs) has been synthesized via a green route by Withania coagulans leaf extract as a reducing and stabilizing agent and its catalytic activity has been tested for the reduction of 4-nitrophenol (4-NP) in water at room temperature. The hydroxyl groups of phenolics in W. coagulans leaf extract is directly responsible for the reduction of Pd(2+), Fe(3+) ions and GO. The nanocomposite was characterized by X-ray diffraction (XRD), fourier transformed infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), Vibrating sample magnetometer (VSM) and transmission electron microscopy (TEM). Furthermore, due to the magnetic separability and high stability of the composite the catalyst can be recovered and recycled several times without marked loss of activity. PMID:26674242

  6. Photo-induced reduction of CO2 using a magnetically separable Ru-CoPc@TiO2@SiO2@Fe3O4 catalyst under visible light irradiation.

    Science.gov (United States)

    Kumar, Pawan; Chauhan, R K; Sain, Bir; Jain, Suman L

    2015-03-14

    An efficient photo-induced reduction of CO2 using magnetically separable Ru-CoPc@TiO2@SiO2@Fe3O4 as a heterogeneous catalyst in which CoPc and Ru(bpy)2phene complexes were attached to a solid support via covalent attachment under visible light is described. The as-synthesized catalyst was characterized by a series of techniques including FTIR, UV-Vis, XRD, SEM, TEM, etc. and subsequently tested for the photocatalytic reduction of carbon dioxide using triethylamine as a sacrificial donor and water as a reaction medium. The developed photocatalyst exhibited a significantly higher catalytic activity to give a methanol yield of 2570.78 ?mol per g cat after 48 h. PMID:25653014

  7. Chloridization and Reduction Roasting of High-Magnesium Low-Nickel Oxide Ore Followed by Magnetic Separation to Enrich Ferronickel Concentrate

    Science.gov (United States)

    Zhou, Shiwei; Wei, Yonggang; Li, Bo; Wang, Hua; Ma, Baozhong; Wang, Chengyan

    2016-02-01

    The chloridization and reduction roasting of high-magnesium, low-nickel oxide ore containing 0.82 pct Ni and 31.49 pct MgO were investigated in this study. Mineralogical investigation indicated that 84.6 pct of nickel was associated with silicates, and nickel was well distributed in mineral in the form of isomorphism. A series of chloridization tests with different added proportions of sodium chloride and coal along with different roasting temperatures and times was conducted. The results indicate that for a ferronickel content of 7.09 pct Ni, a nickel recovery of 98.31 pct could be obtained by chloridizing the laterite ore at 1473 K (1200 C) for 20 minutes with the addition of 10 wt pct sodium chloride and 8 wt pct coal followed by the application of a 150-mT magnetic field. X-ray diffraction indicated that the nickel is mainly present in the form of ferronickel, which can also be detected by SEM-EDS. Compared with the roasted ore with no added chlorinating agent, the ore roasted in the presence of sodium chloride exhibited enhanced ferronickel particle growth.

  8. The mechanism of degradation of bisphenol A using the magnetically separable CuFe2O4/peroxymonosulfate heterogeneous oxidation process.

    Science.gov (United States)

    Xu, Yin; Ai, Jia; Zhang, Hui

    2016-05-15

    The removal of bisphenol A (BPA) in aqueous solution by an oxidation process involving peroxymonosulfate (PMS) activated by CuFe2O4 magnetic nanoparticles (MNPs) is reported herein. The effects of PMS concentration, CuFe2O4 dosage, initial pH, initial BPA concentration, catalyst addition mode, and anions (Cl(-), F(-), ClO4(-) and H2PO4(-)) on BPA degradation were investigated. Results indicate that nearly complete removal of BPA (50mg/L) within 60min and 84.0% TOC removal in 120min could be achieved at neutral pH by using 0.6g/L CuFe2O4 MNPs and 0.3g/L PMS. The generation of reactive radicals (mainly hydroxyl radicals) was confirmed using electron paramagnetic resonance (EPR). Possible mechanisms on the radical generation from CuFe2O4/PMS system are proposed based on the results of radical identification tests and XPS analysis. The lack of inhibition of the reaction by free radical scavengers such as methanol and tert-butyl alcohol suggests that these species may not be generated in the bulk solution, and methylene blue probe experiments confirm that this process does not involve free radical generation. Surface-bound, rather than free radicals generated by a surface catalyzed-redox cycle involving both Fe(III) and Cu(II), are postulated to be responsible for the mineralization of bisphenol A. PMID:26875144

  9. Chloridization and Reduction Roasting of High-Magnesium Low-Nickel Oxide Ore Followed by Magnetic Separation to Enrich Ferronickel Concentrate

    Science.gov (United States)

    Zhou, Shiwei; Wei, Yonggang; Li, Bo; Wang, Hua; Ma, Baozhong; Wang, Chengyan

    2015-10-01

    The chloridization and reduction roasting of high-magnesium, low-nickel oxide ore containing 0.82 pct Ni and 31.49 pct MgO were investigated in this study. Mineralogical investigation indicated that 84.6 pct of nickel was associated with silicates, and nickel was well distributed in mineral in the form of isomorphism. A series of chloridization tests with different added proportions of sodium chloride and coal along with different roasting temperatures and times was conducted. The results indicate that for a ferronickel content of 7.09 pct Ni, a nickel recovery of 98.31 pct could be obtained by chloridizing the laterite ore at 1473 K (1200 C) for 20 minutes with the addition of 10 wt pct sodium chloride and 8 wt pct coal followed by the application of a 150-mT magnetic field. X-ray diffraction indicated that the nickel is mainly present in the form of ferronickel, which can also be detected by SEM-EDS. Compared with the roasted ore with no added chlorinating agent, the ore roasted in the presence of sodium chloride exhibited enhanced ferronickel particle growth.

  10. Preparation of combustible material from high sulphur coal by means of pyrolysis: magnetic separation; Obtencion de combustibles limpios a partir de carbones con altos contenidos en azure mediante procesos de pirolisis: separacion magnetica

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-11-01

    Basic studies on coal desulphurization by pyrolysis have been carried out with a series of low rank coals with high total sulphur contents and differences in the distribution of sulphur forms. The evolved sulphur compounds were studied by sulphide selective electrode H{sub 2}S and Fourier transform infrared (FTIR) spectroscopy. The mechanisms affecting the sulphur removal during pyrolysis have been studied by scanning electron microscopy coupled with energy dispersive X-ray (SEM-EDX), X-ray diffraction (XRD) and photoelectronic spectroscopy (XPS). A sample coal of 11 Tm, representative of the Teruel basins was processed at pilot scale in a rotary kiln (coal HR). A series of pyrolysis runs simulating the experimental conditions of the rotary kiln were also carried out in laboratory scale. The magnetic behaviour of the chars from the rotary kiln and from the lab-scale pyrolysis was tested. The efficiency of the desulphurization, including pyrolysis and magnetic separation, was calculated. Chars from rotary kiln were tested by thermogravimetric analysis, air reactivity and carbon efficiency combustion in fluidized bed.

  11. Production of sulfate radical from peroxymonosulfate induced by a magnetically separable CuFe2O4 spinel in water: efficiency, stability, and mechanism.

    Science.gov (United States)

    Zhang, Tao; Zhu, Haibo; Crou, Jean-Philippe

    2013-03-19

    A simple, nonhazardous, efficient and low energy-consuming process is desirable to generate powerful radicals from peroxymonosulfate (PMS) for recalcitrant pollutant removal. In this work, the production of radical species from PMS induced by a magnetic CuFe(2)O(4) spinel was studied. Iopromide, a recalcitrant model pollutant, was used to investigate the efficiency of this process. CuFe(2)O(4) showed higher activity and 30 times lower Cu(2+) leaching (1.5 ?g L(-1) per 100 mg L(-1)) than a well-crystallized CuO at the same dosage. CuFe(2)O(4) maintained its activity and crystallinity during repeated batch experiments. In comparison, the activity of CuO declined significantly, which was ascribed to the deterioration in its degree of crystallinity. The efficiency of the PMS/CuFe(2)O(4) was highest at neutral pH and decreased at acidic and alkaline pHs. Sulfate radical was the primary radical species responsible for the iopromide degradation. On the basis of the stoichiometry of oxalate degradation in the PMS/CuFe(2)O(4), the radical production yield from PMS was determined to be near 1 mol/mol. The PMS decomposition involved an inner-sphere complexation with the oxide's surface Cu(II) sites. In situ characterization of the oxide surface with ATR-FTIR and Raman during the PMS decomposition suggested that surface Cu(II)-Cu(III)-Cu(II) redox cycle was responsible for the efficient sulfate radical generation from PMS. PMID:23439015

  12. Production of sulfate radical from peroxymonosulfate induced by a magnetically separable CuFe2O4 spinel in water: Efficiency, stability, and mechanism

    KAUST Repository

    Zhang, Tao

    2013-03-19

    A simple, nonhazardous, efficient and low energy-consuming process is desirable to generate powerful radicals from peroxymonosulfate (PMS) for recalcitrant pollutant removal. In this work, the production of radical species from PMS induced by a magnetic CuFe2O4 spinel was studied. Iopromide, a recalcitrant model pollutant, was used to investigate the efficiency of this process. CuFe2O4 showed higher activity and 30 times lower Cu2+ leaching (1.5 ?g L-1 per 100 mg L-1) than a well-crystallized CuO at the same dosage. CuFe 2O4 maintained its activity and crystallinity during repeated batch experiments. In comparison, the activity of CuO declined significantly, which was ascribed to the deterioration in its degree of crystallinity. The efficiency of the PMS/CuFe2O4 was highest at neutral pH and decreased at acidic and alkaline pHs. Sulfate radical was the primary radical species responsible for the iopromide degradation. On the basis of the stoichiometry of oxalate degradation in the PMS/CuFe 2O4, the radical production yield from PMS was determined to be near 1 mol/mol. The PMS decomposition involved an inner-sphere complexation with the oxide\\'s surface Cu(II) sites. In situ characterization of the oxide surface with ATR-FTIR and Raman during the PMS decomposition suggested that surface Cu(II)-Cu(III)-Cu(II) redox cycle was responsible for the efficient sulfate radical generation from PMS. 2013 American Chemical Society.

  13. Superposition of DC magnetic fields by cascading multiple magnets in magnetic loops

    Directory of Open Access Journals (Sweden)

    Fei Sun

    2015-09-01

    Full Text Available A novel method that can effectively collect the DC magnetic field produced by multiple separated magnets is proposed. With the proposed idea of a magnetic loop, the DC magnetic field produced by these separated magnets can be effectively superimposed together. The separated magnets can be cascaded in series or in parallel. A novel nested magnetic loop is also proposed to achieve a higher DC magnetic field in the common air region without increasing the DC magnetic field in each magnetic loop. The magnetic loop can be made by a magnetic hose, which is designed by transformation optics and can be realized by the combination of super-conductors and ferromagnetic materials.

  14. Magnetic nanotubes

    Science.gov (United States)

    Matsui, Hiroshi (Glen Rock, NJ); Matsunaga, Tadashi (Tokyo, JP)

    2010-11-16

    A magnetic nanotube includes bacterial magnetic nanocrystals contacted onto a nanotube which absorbs the nanocrystals. The nanocrystals are contacted on at least one surface of the nanotube. A method of fabricating a magnetic nanotube includes synthesizing the bacterial magnetic nanocrystals, which have an outer layer of proteins. A nanotube provided is capable of absorbing the nanocrystals and contacting the nanotube with the nanocrystals. The nanotube is preferably a peptide bolaamphiphile. A nanotube solution and a nanocrystal solution including a buffer and a concentration of nanocrystals are mixed. The concentration of nanocrystals is optimized, resulting in a nanocrystal to nanotube ratio for which bacterial magnetic nanocrystals are immobilized on at least one surface of the nanotubes. The ratio controls whether the nanocrystals bind only to the interior or to the exterior surfaces of the nanotubes. Uses include cell manipulation and separation, biological assay, enzyme recovery, and biosensors.

  15. Measurement of the elastic electron-proton cross section and separation of the electric and magnetic form factor in the Q{sup 2} range from 0.004 to 1 (GeV/c){sup 2}

    Energy Technology Data Exchange (ETDEWEB)

    Bernauer, Jan C.

    2010-09-24

    The electromagnetic form factors of the proton are fundamental quantities sensitive to the distribution of charge and magnetization inside the proton. Precise knowledge of the form factors, in particular of the charge and magnetization radii provide strong tests for theory in the non-perturbative regime of QCD. However, the existing data at Q{sup 2} below 1 (GeV/c){sup 2} are not precise enough for a hard test of theoretical predictions. For a more precise determination of the form factors, within this work more than 1400 cross sections of the reaction H(e, e{sup '})p were measured at the Mainz Microtron MAMI using the 3-spectrometer-facility of the A1-collaboration. The data were taken in three periods in the years 2006 and 2007 using beam energies of 180, 315, 450, 585, 720 and 855 MeV. They cover the Q{sup 2} region from 0.004 to 1 (GeV/c){sup 2} with counting rate uncertainties below 0.2% for most of the data points. The relative luminosity of the measurements was determined using one of the spectrometers as a luminosity monitor. The overlapping acceptances of the measurements maximize the internal redundancy of the data and allow, together with several additions to the standard experimental setup, for tight control of systematic uncertainties. To account for the radiative processes, an event generator was developed and implemented in the simulation package of the analysis software which works without peaking approximation by explicitly calculating the Bethe-Heitler and Born Feynman diagrams for each event. To separate the form factors and to determine the radii, the data were analyzed by fitting a wide selection of form factor models directly to the measured cross sections. These fits also determined the absolute normalization of the different data subsets. The validity of this method was tested with extensive simulations. The results were compared to an extraction via the standard Rosenbluth technique. The dip structure in G{sub E} that was seen in the analysis of the previous world data shows up in a modi ed form. When compared to the standard-dipole form factor as a smooth curve, the extracted GE exhibits a strong change of the slope around 0.1 (GeV/c){sup 2}, and in the magnetic form factor a dip around 0.2 (GeV/c){sup 2} is found. This may be taken as indications for a pion cloud. For higher Q{sup 2}, the fits yield larger values for G{sub M} than previous measurements, in agreement with form factor ratios from recent precise polarized measurements in the Q{sup 2} region up to 0.6 (GeV/c){sup 2}. The charge and magnetic rms radii are determined as left angle r{sub e} right angle =0.879{+-} 0.005{sub stat.} {+-} 0.004{sub syst.} {+-} 0.002{sub model} {+-} 0.004{sub group} fm; left angle r{sub m} right angle =0.777 {+-} 0.013{sub stat.} {+-} 0.009{sub syst.} {+-} 0.005{sub model} {+-} 0.002{sub group} fm. This charge radius is significantly larger than theoretical predictions and than the radius of the standard dipole. However, it is in agreement with earlier results measured at the Mainz linear accelerator and with determinations from Hydrogen Lamb shift measurements. The extracted magnetic radius is smaller than previous determinations and than the standard-dipole value. (orig.)

  16. Measurement of the elastic electron-proton cross section and separation of the electric and magnetic form factor in the Q2 range from 0.004 to 1 (GeV/c)2

    International Nuclear Information System (INIS)

    The electromagnetic form factors of the proton are fundamental quantities sensitive to the distribution of charge and magnetization inside the proton. Precise knowledge of the form factors, in particular of the charge and magnetization radii provide strong tests for theory in the non-perturbative regime of QCD. However, the existing data at Q2 below 1 (GeV/c)2 are not precise enough for a hard test of theoretical predictions. For a more precise determination of the form factors, within this work more than 1400 cross sections of the reaction H(e, e')p were measured at the Mainz Microtron MAMI using the 3-spectrometer-facility of the A1-collaboration. The data were taken in three periods in the years 2006 and 2007 using beam energies of 180, 315, 450, 585, 720 and 855 MeV. They cover the Q2 region from 0.004 to 1 (GeV/c)2 with counting rate uncertainties below 0.2% for most of the data points. The relative luminosity of the measurements was determined using one of the spectrometers as a luminosity monitor. The overlapping acceptances of the measurements maximize the internal redundancy of the data and allow, together with several additions to the standard experimental setup, for tight control of systematic uncertainties. To account for the radiative processes, an event generator was developed and implemented in the simulation package of the analysis software which works without peaking approximation by explicitly calculating the Bethe-Heitler and Born Feynman diagrams for each event. To separate the form factors and to determine the radii, the data were analyzed by fitting a wide selection of form factor models directly to the measured cross sections. These fits also determined the absolute normalization of the different data subsets. The validity of this method was tested with extensive simulations. The results were compared to an extraction via the standard Rosenbluth technique. The dip structure in GE that was seen in the analysis of the previous world data shows up in a modi ed form. When compared to the standard-dipole form factor as a smooth curve, the extracted GE exhibits a strong change of the slope around 0.1 (GeV/c)2, and in the magnetic form factor a dip around 0.2 (GeV/c)2 is found. This may be taken as indications for a pion cloud. For higher Q2, the fits yield larger values for GM than previous measurements, in agreement with form factor ratios from recent precise polarized measurements in the Q2 region up to 0.6 (GeV/c)2. The charge and magnetic rms radii are determined as left angle re right angle =0.879 0.005stat. 0.004syst. 0.002model 0.004group fm; left angle rm right angle =0.777 0.013stat. 0.009syst. 0.005model 0.002group fm. This charge radius is significantly larger than theoretical predictions and than the radius of the standard dipole. However, it is in agreement with earlier results measured at the Mainz linear accelerator and with determinations from Hydrogen Lamb shift measurements. The extracted magnetic radius is smaller than previous determinations and than the standard-dipole value. (orig.)

  17. Magnetic nanoparticles for Biomedicine.

    Czech Academy of Sciences Publication Activity Database

    afa?k, Ivo; Horsk, Kate?ina; afa?kov, Miroslava

    Dodrecht : Springer, 2011 - (Prokop, A.), s. 363-372 ISBN 9789400712478 R&D Projects: GA MPO 2A-1TP1/094 Institutional research plan: CEZ:AV0Z60870520 Keywords : maghemite * magnetic iron oxides * magnetic particles * magnetic separation * magnetite Subject RIV: FR - Pharmacology ; Medidal Chemistry

  18. Magnetically responsive enzyme powders.

    Czech Academy of Sciences Publication Activity Database

    Pospikov, K.; afa?k, Ivo

    2015-01-01

    Ro?. 380, APR 2015 (2015), s. 197-200. ISSN 0304-8853 R&D Projects: GA Mk(CZ) LD13021 Institutional support: RVO:67179843 Keywords : enzyme powders * cross-linking * magnetic modification * magnetic separation * magnetic iron oxides particles * microwave-assisted synthesis Subject RIV: CE - Biochemistry Impact factor: 1.970, year: 2014

  19. Magnetic Density Separation of Polyolefin Wastes:

    OpenAIRE

    Hu, B.

    2014-01-01

    Polymer recycling has significantly positive impacts on the environment, economics and society. Using recycled polymer to replace virgins reduces the growing amount of post-consumer polymer wastes, decreases the demand for fossil fuel and creates local jobs. As the most used polymer types, polyolefins certainly have attracted attention of recycling. Mechanical sorting has been pointed out as the preferred route for the recovery of relatively clean and homogeneous plastic waste streams....

  20. APIARY B-Factory Separation Scheme

    Energy Technology Data Exchange (ETDEWEB)

    Garren, A.; Sullivan, M.

    1991-05-03

    A magnetic beam-separation scheme for an asymmetric-energy B Factory based on the SLAC electron-positron collider PEP is described that has the following properties: the beams collide head-on and are separated magnetically with sufficient clearance at the parasitic crossing points and at the septum, the magnets have large beam-stay-clear apertures, synchrotron radiation produces low detector backgrounds and acceptable heat loads, and the peak {beta}-function values and contributions to the chromaticities in the IR quadrupoles are moderate.

  1. Apiary B-Factory separation scheme

    Energy Technology Data Exchange (ETDEWEB)

    Garren, A. (Lawrence Berkeley Lab., CA (USA)); Sullivan, M. (Stanford Linear Accelerator Center, Menlo Park, CA (USA))

    1991-04-01

    A magnetic beam-separation scheme for an asymmetric-energy B-Factory based on the SLAC electron-positron collider PEP is described that has the following properties: the beams collide head-on and are separated magnetically with sufficient clearance at the parasitic crossing points and at the septum, the magnets have large beam-stay-clear apertures, synchrotron radiation produces low detector backgrounds and acceptable heat loads, and the peak {beta}-function values and contributions to the chromaticities in the IR quadrupoles are moderate. 8 figs., 2 tabs.

  2. Application of Rare Earth Magnets in Mineral Processing

    OpenAIRE

    Wells, I. S.; N.A.Rowson

    1992-01-01

    Recent advances in permanent magnet technology have led to the development of a new generation of permanent rare earth industrial magnetic separators. The excellent separation efficiency of these rare earth magnetic separators has reselted in them superceeding conventional electromagnetic high-intensity magnetic separators for many applications. One example of this technology is the Boxmag-Rapid Magnaroll magnetic separator which has been successfully installed for mineral processing applicat...

  3. Protein purification using magnetic adsorbent particles

    DEFF Research Database (Denmark)

    Franzreb, M; Siemann-Herzberg, M.; Hobley, Timothy John; Thomas, O.R.T.

    2006-01-01

    The application of functionalised magnetic adsorbent particles in combination with magnetic separation techniques has received considerable attention in recent years. The magnetically responsive nature of such adsorbent particles permits their selective manipulation and separation in the presence...... current state of development of protein separation using magnetic adsorbent particles and identify the obstacles that must be overcome if protein purification with magnetic adsorbent particles is to find its way into industrial practice....

  4. Microfluidic immunomagnetic cell separation from whole blood.

    Science.gov (United States)

    Bhuvanendran Nair Gourikutty, Sajay; Chang, Chia-Pin; Puiu, Poenar Daniel

    2016-02-01

    Immunomagnetic-based separation has become a viable technique for the separation of cells and biomolecules. Here we report on the design and analysis of a simple and efficient microfluidic device for high throughput and high efficiency capture of cells tagged with magnetic particles. This is made possible by using a microfluidic chip integrated with customized arrays of permanent magnets capable of creating large magnetic field gradients, which determine the effective capturing of the tagged cells. This method is based on manipulating the cells which are under the influence of a combination of magnetic and fluid dynamic forces in a fluid under laminar flow through a microfluidic chip. A finite element analysis (FEA) model is developed to analyze the cell separation process and predict its behavior, which is validated subsequently by the experimental results. The magnetic field gradients created by various arrangements of magnetic arrays have been simulated using FEA and the influence of these field gradients on cell separation has been studied with the design of our microfluidic chip. The proof-of-concept for the proposed technique is demonstrated by capturing white blood cells (WBCs) from whole human blood. CD45-conjugated magnetic particles were added into whole blood samples to label WBCs and the mixture was flown through our microfluidic device to separate the labeled cells. After the separation process, the remaining WBCs in the elute were counted to determine the capture efficiency, and it was found that more than 99.9% WBCs have been successfully separated from whole blood. The proposed design can be used for positive selection as well as for negative enrichment of rare cells. PMID:26773879

  5. Particle acceleration at reconnecting separator current layers

    CERN Document Server

    Threlfall, J; Parnell, C E; Neukirch, T

    2015-01-01

    The aim of this work is to investigate and characterise particle behaviour in a 3D MHD model of a reconnecting magnetic separator. We use a relativistic guiding-centre test-particle code to investigate electron and proton acceleration in snapshots from 3D MHD separator reconnection experiments, and compare the results with findings from an analytical separator reconnection model studied in a previous investigation. The behaviour (and acceleration) of large distributions of particles are examined in detail for both analytical and numerical separator reconnection models. Differences in acceleration sites are recovered and discussed, together with the dependence of final particle energy ranges upon the dimensions of the models and the stage of the (time-dependent) MHD reconnection event. We discuss the implications of these results for observed magnetic separators in the solar corona.

  6. Separation Anxiety (For Parents)

    Science.gov (United States)

    ... for Your Child All About Food Allergies Separation Anxiety KidsHealth > For Parents > Separation Anxiety Print A A ... both of you get through it. How Separation Anxiety Develops Babies adapt pretty well to other caregivers. ...

  7. Horizontally separated 1-in-1 crossing insertions

    Energy Technology Data Exchange (ETDEWEB)

    Syphers, M.J. [Fermi National Accelerator Lab., Batavia, IL (United States)

    1985-10-01

    Previous to this workshop, realistic lattices have been developed for vertically separated l-in-l (e.g., D.E. Johnson, A.A. Garren) and 2-in-1 (e.g., S. Heifets) magnets as well as for horizontally separated 2-in-l magnets (e.g., SSC RDS). Bringing together the widely separated ({approximately}60-70 cm) beams in a reasonable length of tunnel and keeping the dispersion zero at the interaction point has been difficult in the vertical l-in-l case. Most designs have required spacial 2-in-1 quadrupoles near the interaction point where the beams are separated by 15 cm or less. It is not clear that such magnets, as dictated by some of these lattice designs, can easily be built. The purpose of this exercise is to provide a crossing insertion for a realistic lattice which involves horizontally separated l-in-l magnets. The following horizontal crossing insertions, which incorporate the dispersion suppressors and phase trombones into the major arcs, need no special 2-in-1 magnets near the interaction point. The dispersion at the IP created by the horizontal crossing can be cancelled by the dispersion suppressor and one set of triplets.

  8. Fictional Separation Logic

    DEFF Research Database (Denmark)

    Jensen, Jonas Buhrkal; Birkedal, Lars

    , separation means physical separation. In this paper, we introduce \\emph{fictional separation logic}, which includes more general forms of fictional separating conjunctions P * Q, where "*" does not require physical separation, but may also be used in situations where the memory resources described by P and Q...... overlap. We demonstrate, via a range of examples, how fictional separation logic can be used to reason locally and modularly about mutable abstract data types, possibly implemented using sophisticated sharing. Fictional separation logic is defined on top of standard separation logic, and both the meta...

  9. Characteristics of magnetic field induction inside a module of a magnetic separator ХАРАКТЕРИСТИКИ ИНДУКЦИИ ПОЛЯ В МОДУЛЕ МАГНИТНОГО СЕПАРАТОРА

    Directory of Open Access Journals (Sweden)

    Sandulyak Anna Aleksandrovna

    2013-05-01

    Full Text Available Characteristics of magnetic separators are analyzed in the article. Magnetic separators are used to treat various construction materials. Unfortunately, the nature of the magnetic field, generated in their operating zone, is generally not taken into account by their designers. Academic publications fail to provide any detailed basic characteristics of the field induction emitted by magnetic separators in the course of their operation.Magnetic systems of any magnetic separator have a modular structure; they consist of several modules. Single and opposite magnetic elements are usually integrated into one module within a system having permanent magnets. If opposite magnetic elements are used, magnetic field intensity inside the module increases.In this study, characteristics of magnetic induction for single magnetic elements inside various modules of magnetic separators were assessed in a laboratory experiment. Similar characteristics of magnetic induction for single and twin (opposite magnetic elements were compared. In the module consisting of two opposed magnetic elements, the magnetic field becomes stronger compared to the field of a single magnetic element. Magnetic induction in the module recedes as the distance between magnetic elements increases, because of the isolation of the field generated by the opposed magnetic elements.The authors have proven the feasibility and expediency of employment of the superposition principle used to obtain the resulting characteristics. It may be employed to substitute modeling by calculations.Экспериментально получены характеристики индукции магнитного поля для одиночных элементов в различных модулях магнитных сепараторов. Сопоставлены характеристики индукции магнитного поля для одиночных и спаренных магнитных элементов модуля. В модуле, состоящем и двух противостоящих магнитных элементов, поле усиливается по сравнению с полем одиночного модульного элемента, хотя по мере увеличения межполюсного расстояния уровень индукции в модуле снижается за счет все большего «разобщения» встречных полей, создаваемых противостоящими магнитными элементами.Показана возможность и практическая целесообразность использования принципа суперпозиции для установления результирующей характеристики индукции поля между противостоящими магнитными элементами для замены реального моделирования расчетным.

  10. Microfluidic Device for Continuous Magnetophoretic Separation of Red Blood Cells

    OpenAIRE

    Iliescu, Ciprian; Barbarini, Elena; Avram, Marioara; Xu, G; Avram, Andrei

    2008-01-01

    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...

  11. The isotopic contamination in electromagnetic isotope separators

    International Nuclear Information System (INIS)

    In the early years of isotope separation, and in particular electromagnetic isotope separation, needs for rapid results have conducted to empiric research. This paper describes fundamental research on the electromagnetic isotope separation to a better understanding of isotope separators as well as improving the performances. Focus has been made on the study of the principle of isotope contamination and the remedial action on the separator to improve the isotope separation ratio. In a first part, the author come back to the functioning of an electromagnetic separator and generalities on isotope contamination. Secondly, it describes the two stages separation method with two dispersive apparatus, an electromagnetic separation stage followed by an electrostatic separation stage, both separated by a diaphragm. The specifications of the electrostatic stage are given and its different settings and their consequences on isotope separation are investigated. In a third part, mechanisms and contamination factors in the isotope separation are discussed: natural isotope contamination, contamination by rebounding on the collector, contamination because of a low resolution, contamination by chromatism and diffusion effect, breakdown of condenser voltage. Analysis of experimental results shows the diffusion as the most important contamination factor in electromagnetic isotope separation. As contamination factors are dependent on geometric parameters, sector angle, radius of curvature in the magnetic field and clearance height are discussed in a fourth part. The better understanding of the mechanism of the different contamination factors and the study of influential parameters as pressure and geometric parameters lead to define a global scheme of isotope contamination and determinate optima separator design and experimental parameters. Finally, the global scheme of isotope contamination and hypothesis on optima specifications and experimental parameters has been checked during a series of experiments for the separation of cadmium isotopes. (M.P.)

  12. Vacuum arc plasma mass separator

    International Nuclear Information System (INIS)

    The propagation of a metal plasma flow in a transport system with a curvilinear magnetic field was studied experimentally. The flow was generated by a pulsed vacuum arc discharge with a composite (W+Fe) cathode. The ion energy measurements at the transport system output showed that all ion components were accelerated up to equal energies per charge unit, about 150eV and 320eV in the outer and inner areas of the curved plasma flow, respectively. The spatial separation of the atoms of the cathode material was measured at the system output by x-ray fluorescence spectrometry. The ions of the lighter element (Fe) were concentrated in the inner part of the cathodic plasma flow deflected by the magnetic field while the distribution of the heavy element (W) was substantially shifted toward the outer area of the flow. The maximum mass separation efficiency reached 45, the effective value being 7.7. Such a system is promising for use in plasma technology for reprocessing spent nuclear fuel, namely for the separation of the heavy radioactive fission product from nuclear waste. (paper)

  13. Method of and apparatus for the separation of isotopes

    International Nuclear Information System (INIS)

    A method of separating one isotope of an element from the others which comprises the steps of generating a substantially neutral plasma including an element having at least two ionized isotopes to be separated; generating a substantially steady magnetic field extending through the plasma; imparting more energy to a selected isotope than to the other isotopes while the element is in the magnetic field; and separating the isotopes from each other on the basis of their differential energies

  14. Rf separators and separated beams at SLAC

    International Nuclear Information System (INIS)

    For particle momenta above approximately 5 GeV/c, the only effective means of separation by particle mass in secondary beams is using rf deflectors. Particle separation at proton synchrotrons requires the use of two rf deflectors. The beam structure at SLAC permits the use of a single deflector. (auth)

  15. Isobar separator for radioactive nuclear beams project

    Energy Technology Data Exchange (ETDEWEB)

    Davids, C.N.; Nolen, J.A.

    1995-08-01

    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.

  16. Isotope separation by ionic cyclotron resonance

    International Nuclear Information System (INIS)

    The principle of the process of isotopic separation by ionic cyclotron resonance is explained succinctly. The theoretical calculation of the isotopic effect is given as functions of the electric and magnetic fields in the frame of single particle approximation and of plasma collective theory. Then, the main parts of the demonstration device which is in operation at the CEA, are described here: the supraconducting magnetic field, the used diagnostics, the principle of the source and the collecting apparatus. Some experimental results are given for chromium. The application of the process to ponderal separation of metal isotopes, as chromium, nickel and molybdenum is discussed in view of production of medical, structural and irradiation isotopes

  17. Protein purification using magnetic adsorbent particles

    DEFF Research Database (Denmark)

    Franzreb, M; Siemann-Herzberg, M.; Hobley, Timothy John; Thomas, O.R.T.

    2006-01-01

    The application of functionalised magnetic adsorbent particles in combination with magnetic separation techniques has received considerable attention in recent years. The magnetically responsive nature of such adsorbent particles permits their selective manipulation and separation in the presence of other suspended solids. Thus, it becomes possible to magnetically separate selected target species directly out of crude biological process liquors (e.g. fermentation broths, cell disruptates, plasma...

  18. Three dimensional magnetic abacus memory.

    OpenAIRE

    Zhang, S; Zhang, J.; Baker, AA; S. Wang; Yu, G; Hesjedal, T

    2014-01-01

    Stacking nonvolatile memory cells into a three-dimensional matrix represents a powerful solution for the future of magnetic memory. However, it is technologically challenging to access the data in the storage medium if large numbers of bits are stacked on top of each other. Here we introduce a new type of multilevel, nonvolatile magnetic memory concept, the magnetic abacus. Instead of storing information in individual magnetic layers, thereby having to read out each magnetic layer separately,...

  19. Three dimensional magnetic abacus memory

    OpenAIRE

    Zhang, Shilei; Zhang, Jingyan; Baker, Alexander A.; Wang, Shouguo; Yu, GuangHua; Hesjedal, Thorsten

    2014-01-01

    Stacking nonvolatile memory cells into a three-dimensional matrix represents a powerful solution for the future of magnetic memory. However, it is technologically challenging to access the data in the storage medium if large numbers of bits are stacked on top of each other. Here we introduce a new type of multilevel, nonvolatile magnetic memory concept, the magnetic abacus. Instead of storing information in individual magnetic layers, thereby having to read out each magnetic layer separately,...

  20. Magnetic fluids

    Science.gov (United States)

    Rosensweig, R. E.

    1982-10-01

    An overview of studies done on ferrofluids is presented, and recently discovered technological uses for such a fluid are examined. By interacting magnetization and pressure, a ferrofluid plug, held in place by a focused magnetic field imposed from the outside, serves as an airtight seal in rotating machinery. A 160 stage rotary seal has withstood a pressure differential of 66 atmospheres. The fluid has also proved useful in the design of loudspeakers, as it does not drip out of the gap in the cylindrical permanent magnet which allows the voice coil to move, thus serving as a coolant for the system. Finally, the fluid can be used to separate materials according to density, as the magnetic-levitation forces that can be established in the fluid are strong enough to float materials of any density. Other applications are being explored, such as an induced convection that can be much more vigorous than simple gravity convection when a gradient magnetic field is applied to a heated ferrofluid.

  1. Superconducting magnets

    International Nuclear Information System (INIS)

    A superconductor is an electrical conductor which is capable of carrying a 'Supercurrent' and the transmission of energy is 'loss-less'. If such conductors were generally available the implications for industries would be enormous. Unfortunately, superconductivity occurs only in certain materials under certain conditions. The transition of any superconductor from the superconducting mode to 'normal' or resistive mode is a function of absolute temperature, current density within the conductor and local magnetic field intensity. If any one of these parameters exceeds a certain 'critical value' superconductivity is destroyed. Superconducting magnets for high energy physics and medical imaging are discussed. Experience gained in the maturing medical imaging industry has demonstrated beyond doubt that superconducting magnets, even at liquid helium temperatures can today be regarded as industrial pieces of electrical machinery. The advances in magnet stability, cryogenic engineering and refrigeration technology make it feasible for superconductivity to be considered seriously for other electrical engineering applications such as, for example, energy storage, levitation and magnetic separation of ores and minerals. Whereas the impact of the new high temperature superconductors on electrical engineering can at present only be imagined, there is general agreement that ambient temperature superconducting electrical machinery will not be generally available for at least another decade. However, when it does come, electrical engineering will be altered immeasurably. 4 figs., 1 tab

  2. Magnetically responsive enzyme powders

    Science.gov (United States)

    Pospiskova, Kristyna; Safarik, Ivo

    2015-04-01

    Powdered enzymes were transformed into their insoluble magnetic derivatives retaining their catalytic activity. Enzyme powders (e.g., trypsin and lipase) were suspended in various liquid media not allowing their solubilization (e.g., saturated ammonium sulfate and highly concentrated polyethylene glycol solutions, ethanol, methanol, 2-propanol) and subsequently cross-linked with glutaraldehyde. Magnetic modification was successfully performed at low temperature in a freezer (-20 C) using magnetic iron oxides nano- and microparticles prepared by microwave-assisted synthesis from ferrous sulfate. Magnetized cross-linked enzyme powders were stable at least for two months in water suspension without leakage of fixed magnetic particles. Operational stability of magnetically responsive enzymes during eight repeated reaction cycles was generally without loss of enzyme activity. Separation of magnetically modified cross-linked powdered enzymes from reaction mixtures was significantly simplified due to their magnetic properties.

  3. On Separation of Variables

    CERN Document Server

    Viazminsky, C P

    2002-01-01

    The necessary and sufficient conditions for a function to be totally or partially separable are derived. It is shown that a function is totally separable if and only if each component of the gradient vector of depends only on the corresponding variable. The conditions of separability are expressed neatly in terms of the matrix which has to be diagonal if the function is to be totally separable, and has to assume a diagonal block form in order that the function is partially separable. The conditions of separability are also given without using derivatives. For polynomials, the conditions of separability are shown to hold if and only if the product of the first column and the first row of the coefficients matrix is equal to the matrix itself. This promotes an easy computational scheme for checking, and actually carrying out, variable separation.

  4. Magnetic isotope effect

    Energy Technology Data Exchange (ETDEWEB)

    Buchachenko, A.L. [N.N. Semenov Inst. of Chemical Physics, Moscow (Russian Federation)

    1995-11-01

    The electron spin selectivity of radical reactions is accompanied by nuclear spin selectivity, i.e., sorting of the isotopic nuclei relative to their magnetic moment. This property of spin-selective reactions produces separation of magnetic and nonmagnetic isotopes known as the magnetic isotope effect. The chemical physics of this phenomenon is examined along with the conditions and magnitude of its manifestation as well as the prospects for its use in theoretical and experimental chemistry.

  5. Phase separator safety valve blow-off.

    CERN Document Server

    G. Perinic

    2006-01-01

    The fast discharge of the CMS solenoid leads to a pressure rise in the phase separator. On August 28th, a fast discharge was triggered at a current level of 19.1 kA. The pressure in the phase separator increased up to the set pressure of the safety valve and some helium was discharged. In consequence of this and prevoious similar observations the liquid helium level in the phase separator has been reduced from 60% to 50% and later to 45% in order to reduce the helium inventory in the magnet.

  6. Enhancement of giant magnetoresistance effect in the Ruddlesden-Popper phase Sr3Fe2-xCoxO7-d: Predominant role of oxygen nonstoichiometry and magnetic phase separation

    CERN Document Server

    Motohashi, T; Hervieu, M; Maignan, A; Nguyen, N; Pralong, V; Raveau, B

    2006-01-01

    The magnetic and magnetotransport properties of the Sr3Fe2-xCoxO7-d system (0.2 <= x <= 1.0) were systematically investigated. This oxide system exhibits a giant magnetoresistance (GMR) effect at low temperatures, reaching up to 80% in 7 T at 5 K. Ac-susceptibility measurements show that there exists a strong competition between ferromagnetic (F) and spin glass states, and the balance between these two magnetic states can be controlled by varying cobalt (x) and/or oxygen contents (d). Importantly, the MR effect is closely related to the magnetic property: the development of magnetic disordering leads to enhancement in the negative MR effect. It is suggested that the compound segregates into F clusters embedded in a non-F matrix, being a naturally occurring analog of the artificial granular-GMR materials, as in the doped perovskite cobaltites, La1-xSrxCoO3 (x < 0.18).

  7. Enhancement of giant magnetoresistance effect in the Ruddlesden-Popper phase Sr3Fe2-xCoxO7-?: predominant role of oxygen nonstoichiometry and magnetic phase separation

    International Nuclear Information System (INIS)

    The magnetic and magnetotransport properties of the Sr3Fe2-xCoxO7-? system (0.2?x?1.0) have been systematically investigated. This oxide system exhibits a giant magnetoresistance (GMR) effect at low temperatures, reaching up to 80% in 7 T at 5 K. Ac-susceptibility measurements show that there exists a strong competition between ferromagnetic (F) and spin glass states, and the balance between these two magnetic states can be controlled by varying cobalt (x) and/or oxygen contents (?). Importantly, the MR effect is closely related to the magnetic property: the development of magnetic disordering leads to enhancement in the negative MR effect. It is suggested that the compound segregates into F clusters embedded in a non-F matrix, being a naturally occurring analogue of the artificial granular-GMR materials, as in the doped perovskite cobaltites, La1-xSrxCoO3 (x< 0.18)

  8. Electronic and magnetic phase separation in EuB{sub 6}. Fluctuation spectroscopy and nonlinear transport; Elektronische und magnetische Phasenseparation in EuB{sub 6}. Fluktuationsspektroskopie und nichtlinearer Transport

    Energy Technology Data Exchange (ETDEWEB)

    Amyan, Adham

    2013-07-09

    The main topics of this thesis are electrical, stationary, and time-resolved transport measurements on EuB{sub 6} as well as the further development of measuring methods and analysis procedures of the fluctuation spectroscopy. The first part of this thesis was dedicated to the further development of the already known measuring methods under application of a fast data-acquisition card. The second part deals with the electrical transport properties of EuB{sub 6} and the understanding of the coupling between charge and magnetic degrees of freedom. By means of resistance and nonlinear-transport measurements as well as fluctuation spectroscopy hypotheses of other scientists were systematically verified as well as new knowledge obtained. The magnetoresistance was studied as function of the temperature in small external magnetic fields between 1 mT and 700 mT. Measurements of the third harmonic resistance as function of the temperature show maxima at T{sub MI} and T{sub C}. Electrical-resistance fluctuations were measured without external magnetic field between 5 and 100 K as well in presence of a magnetic field between 18 K and 32 K. At constant temperature measurements of the spectral power density in external magnetic fields were performed in the temperature range from 18 K to 32 K. Highly resolving measurements of the thermal expansion coefficient showed a very strong coupling of the magnetic (polaronic) degrees of freedom to the crystal lattice.

  9. Safety shutdown separators

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Steven Allen; Anakor, Ifenna Kingsley; Farrell, Greg Robert

    2015-06-30

    The present invention pertains to electrochemical cells which comprise (a) an anode; (b) a cathode; (c) a solid porous separator, such as a polyolefin, xerogel, or inorganic oxide separator; and (d) a nonaqueous electrolyte, wherein the separator comprises a porous membrane having a microporous coating comprising polymer particles which have not coalesced to form a continuous film. This microporous coating on the separator acts as a safety shutdown layer that rapidly increases the internal resistivity and shuts the cell down upon heating to an elevated temperature, such as 110.degree. C. Also provided are methods for increasing the safety of an electrochemical cell by utilizing such separators with a safety shutdown layer.

  10. Freely oriented portable superconducting magnet

    Science.gov (United States)

    Schmierer, Eric N. (Los Alamos, NM); Prenger, F. Coyne (Los Alamos, NM); Hill, Dallas D. (Los Alamos, NM)

    2010-01-12

    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.

  11. Protein purification using magnetic adsorbent particles

    DEFF Research Database (Denmark)

    Franzreb, M; Siemann-Herzberg, M.

    2006-01-01

    The application of functionalised magnetic adsorbent particles in combination with magnetic separation techniques has received considerable attention in recent years. The magnetically responsive nature of such adsorbent particles permits their selective manipulation and separation in the presence of other suspended solids. Thus, it becomes possible to magnetically separate selected target species directly out of crude biological process liquors (e.g. fermentation broths, cell disruptates, plasma, milk, whey and plant extracts) simply by binding them on magnetic adsorbents before application of a magnetic field. By using magnetic separation in this way, the several stages of sample pretreatment (especially centrifugation, filtration and membrane separation) that are normally necessary to condition an extract before its application on packed bed chromatography columns, may be eliminated. Magnetic separations are fast, gentle, scaleable, easily automated, can achieve separations that would be impossible or impractical to achieve by other techniques, and have demonstrated credibility in a wide range of disciplines, including minerals processing, wastewater treatment, molecular biology, cell sorting and clinical diagnostics. However, despite the highly attractive qualities of magnetic methods on a process scale, with the exception of wastewater treatment, few attempts to scale up magnetic operations in biotechnology have been reported thus far. The purpose of this review is to summarise the current state of development of protein separation using magnetic adsorbent particles and identify the obstacles that must be overcome if protein purification with magnetic adsorbent particles is to find its way into industrial practice.

  12. Separator for separating liquid from gas

    Energy Technology Data Exchange (ETDEWEB)

    Kazaryan, V.A.; Chirkin, A.V.; Fedorov, B.N.; Filonenko, N.A.; Pyshkov, N.N.; Rachevskiy, B.S.

    1981-02-07

    A separator is suggested for separating liquid from gas. It includes a housing with sleeve for gas input and conical reflectors arranged on top of each other, and overflow sleeve. In order to improve the effectiveness of separating liquid from gas by eliminating the secondary drop remover, it is equipped with guide sleeves arranged on the surface of the lower reflector, conical settling tank arranged above the sleeve of gas inlet, skirts attached to the lower edges of the lower and middle reflector and lowered under the level of the liquid in the housing, by-pass pipeline connecting the upper and lower part of the housing. The middle reflector is made with openings shifted in relation to the axis of the control sleeves, and the upper reflector is made in the form of a truncated cone attached to the walls of the housing.

  13. Rapid chemical separations

    CERN Document Server

    Trautmann, N

    1976-01-01

    A survey is given on the progress of fast chemical separation procedures during the last few years. Fast, discontinuous separation techniques are illustrated by a procedure for niobium. The use of such techniques for the chemical characterization of the heaviest known elements is described. Other rapid separation methods from aqueous solutions are summarized. The application of the high speed liquid chromatography to the separation of chemically similar elements is outlined. The use of the gas jet recoil transport method for nuclear reaction products and its combination with a continuous solvent extraction technique and with a thermochromatographic separation is presented. Different separation methods in the gas phase are briefly discussed and the attachment of a thermochromatographic technique to an on-line mass separator is shown. (45 refs).

  14. Superconducting magnets and cryogenics: proceedings

    International Nuclear Information System (INIS)

    Separate abstracts were prepared for 70 papers in these workshop proceeedings. Topics covered include: superconducting accelerator magnet research and development; superconductor development; electrical measurements; magnet design and construction methods; field correction methods; power schemes and quench protection; cryogenic systems; and magnet measurements

  15. Electromagnetic Separator of a Plasma

    International Nuclear Information System (INIS)

    Simple freestanding 90 deg. filter is used for obtaining the metallic vacuum coatings. As the source of metallic plasma adapted standard cathode vaporizer on the installation ''Bulat 6''. Plasma flow from the cathode flowed through the not protected by isolation spiral (solenoid). The solenoid outlet from the side of cathode find under the floating potential. The second solenoid outlet was connected to the autonomous power supply. Solenoid was prepared with the wide interval of the coil winding and with the turning to 90 degrees. Therefore, drifting charged of particle can freely depart from the interior of solenoid outside. The glow of the turned flow of plasma is observed during the supplying to the cathode and the solenoid. Flow is separation from the coils and is extended along the axis of solenoid. In this case over the solenoid flow the current 20-90 A, the voltage of solenoid relative to vessel (earth) + 15 V. We assume, that this device ensures radial electric field relative to the basic nucleus of the plasma (diameter of the nucleus of plasma column it is commensurate with the diameter of cathode) and the current of solenoid creates the longitudinal magnetic field (estimated order 20 oersted). Magnetic field strength is sufficient for the magnetization of electrons, but it is very small for the ions and the charged microdroplets. The carried out experiments on the application of coatings on the dielectric substrate with the use of aluminum and titanium cathodes showed the effectiveness of the work of this separator. Coatings without the drops are obtained also on the glass substrate with HF- displacement. The reflective properties of the metallic films (Ti,Al) on the glass samples were measured

  16. Separation of a mixture of particles into its individual components with the aid of the magneto-Archimedes separation

    International Nuclear Information System (INIS)

    The magneto-Archimedes separation allows for separating mixtures of feeble magnetic materials into its components based on the difference of their densities and magnetic susceptibilities. So far, this technique was applied for the separation of relatively large particles of several millimeters in diameter. Here we apply this technique experimentally to the simultaneous quantitative analysis of multiple micrometer-sized particles in a fluid. It was confirmed that the magneto-Archimedes separation can be applied for the separation of mixture of microspheres larger than 20 μm. Further high performance separation efficiency is expected with the optimization of separation conditions including the control of the spatial distribution of the magnetic field. - Highlights: • The magneto-Archimedes separation is based on the magnetic levitation of materials. • It allows for separating mixtures into its components by the difference of properties. • The separation of mixture of spheres larger than 20 μm was confirmed experimentally. • It enables the simultaneous quantitative analysis of multiple particles

  17. Measurement of the elastic electron-proton cross section and separation of the electric and magnetic form factor in the Q 2 range from 0.004 to 1 (GeV/c) 2

    OpenAIRE

    Bernauer, Jan C.

    2010-01-01

    The electromagnetic form factors of the proton are fundamental quantities sensitive to the distribution of charge and magnetization inside the proton. Precise knowledge of the form factors, in particular of the charge and magnetization radii provide strong tests for theory in the non-perturbative regime of QCD. However, the existing data at Q^2 below 1 (GeV/c)^2 are not precise enough for a hard test of theoretical predictions.rnrnFor a more precise determination of the form factors, within t...

  18. Cascade of centrifugal separator

    International Nuclear Information System (INIS)

    Object: To reduce installation area of cascade in centrifugal separator and to improve separation performance of the separator by means of an effective arrangement of a plurality of ideal cascade units. Structure: A plurality of complex cascades are utilized as constructive elements, each comprising a pair of ideal cascade units arranged in reversal parallel relation to each other with condensation or recovery stages thereof being adjacent each other. (Furukawa, Y.)

  19. Stem Cell Separation Technologies

    OpenAIRE

    Zhu, Beili; Murthy, Shashi K

    2013-01-01

    Stem cell therapy and translational stem cell research require large-scale supply of stem cells at high purity and viability, thus leading to the development of stem cell separation technologies. This review covers key technologies being applied to stem cell separation, and also highlights exciting new approaches in this field. First, we will cover conventional separation methods that are commercially available and have been widely adapted. These methods include Fluorescence-activated cell so...

  20. Graph separators, with applications

    CERN Document Server

    Rosenberg, Arnold L

    2001-01-01

    This text is devoted to techniques for obtaining upper and lower bounds on the sizes of graph separators - upper bounds being obtained via decomposition algorithms. The book surveys the main approaches to obtaining good graph separations, while its main focus is on techniques for deriving lower bounds on the sizes of graph separators. This asymmetry in focus reflects the perception that the work on upper bounds, or algorithms, for graph separation is much better represented in the standard theory literature than is the work on lower bounds, which we perceive as being much more scattered throug