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Deltell A, Mohamed AEMA, Álvarez-Alonso P, Ipatov M, Andrés J, González J, Sánchez T, Zhukov A, Escoda M, Suñol J, López Antón R. Martensitic transformation, magnetic and magnetocaloric properties of Ni–Mn–Fe–Sn Heusler ribbons. Journal of Materials Research and Technology 2021; 12:1091-1103. [DOI: 10.1016/j.jmrt.2021.03.049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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2
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Mitxelena-Iribarren O, Campisi J, Martínez de Apellániz I, Lizarbe-Sancha S, Arana S, Zhukova V, Mujika M, Zhukov A. Glass-coated ferromagnetic microwire-induced magnetic hyperthermia for in vitro cancer cell treatment. Materials Science and Engineering: C 2020; 106:110261. [DOI: 10.1016/j.msec.2019.110261] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 09/25/2019] [Accepted: 09/25/2019] [Indexed: 10/25/2022]
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3
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Welton RF, Han BX, Stockli MP, Murray SN, Pennisi TR, Stinson C, Barnett W, Aleksandrov A, Piller M, Saethre R, Kang Y, Zhukov A. Installation and commissioning of the ion source systems for the new spallation neutron source 2.5 MeV injector. Rev Sci Instrum 2020; 91:013334. [PMID: 32012529 DOI: 10.1063/1.5128508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 01/07/2020] [Indexed: 06/10/2023]
Abstract
The U.S. Spallation Neutron Source (SNS) is a state-of-the-art neutron scattering facility delivering the world's most intense pulsed neutron beams to a wide array of instruments, which are used to conduct investigations in many fields of engineering, physics, chemistry, material science, and biology. Neutrons are produced by spallation of liquid Hg by the bombardment of short (∼1 µs), intense (∼35 A) pulses of protons delivered at 60 Hz by an accumulator ring which is fed by a high-intensity, 1 GeV, H- LINAC (linear accelerator). This facility has operated nearly continuously since 2006 but has recently undergone a 4-month maintenance period, which featured a complete replacement of the 2.5 MeV injector feeding the LINAC. The new injector was developed at ORNL in an off-line beam test facility and consists of an ion source, low energy beam transport, and a Radio Frequency Quadrupole (RFQ). This report first describes the installed configuration of the new injector detailing the ion source system. The first beam current, RFQ transmission, emittance, and energy measurements from the injector installed on the SNS are reported. These data not only show a significant performance improvement for our existing facility but will also make accessible the higher beam current requirements for future SNS upgrade projects: the proton power upgrade and second target station.
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Affiliation(s)
- R F Welton
- Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37830-6471, USA
| | - B X Han
- Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37830-6471, USA
| | - M P Stockli
- Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37830-6471, USA
| | - S N Murray
- Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37830-6471, USA
| | - T R Pennisi
- Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37830-6471, USA
| | - C Stinson
- Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37830-6471, USA
| | - W Barnett
- Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37830-6471, USA
| | - A Aleksandrov
- Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37830-6471, USA
| | - M Piller
- Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37830-6471, USA
| | - R Saethre
- Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37830-6471, USA
| | - Y Kang
- Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37830-6471, USA
| | - A Zhukov
- Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37830-6471, USA
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Corte-León P, Blanco JM, Zhukova V, Ipatov M, Gonzalez J, Churyukanova M, Taskaev S, Zhukov A. Engineering of Magnetic Softness and Domain Wall Dynamics of Fe-rich Amorphous Microwires by Stress- induced Magnetic Anisotropy. Sci Rep 2019; 9:12427. [PMID: 31455829 PMCID: PMC6711959 DOI: 10.1038/s41598-019-48755-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 08/06/2019] [Indexed: 11/09/2022] Open
Abstract
We observed a remarkable improvement of domain wall (DW) mobility, DW velocity, giant magnetoimpedance (GMI) effect and magnetic softening at appropriate stress-annealing conditions. Beneficial effect of stress-annealing on GMI effect and DW dynamics is associated with the induced transverse magnetic anisotropy. An improvement of the circumferential permeability in the nearly surface area of metallic nucleus is evidenced from observed magnetic softening and remarkable GMI effect rising. We assumed that the outer domain shell with transverse magnetic anisotropy associated to stress-annealing induced transverse magnetic anisotropy affects the travelling DW in a similar way as application of transversal bias magnetic field allowing enhancement the DW velocity. Observed decreasing of the half-width of the EMF peak in stress-annealed microwires can be associated to the decreasing of the characteristic DW width. Consequently, stress annealing enabled us to design the magnetic anisotropy distribution beneficial for optimization of either GMI effect or DW dynamics.
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Affiliation(s)
- P Corte-León
- Dpto. Física de Materiales, Fac. Químicas, UPV/EHU, 20018, San Sebastian, Spain
- Dpto. de Física Aplicada, EIG, UPV/EHU, 20018, San Sebastian, Spain
| | - J M Blanco
- Dpto. de Física Aplicada, EIG, UPV/EHU, 20018, San Sebastian, Spain
| | - V Zhukova
- Dpto. Física de Materiales, Fac. Químicas, UPV/EHU, 20018, San Sebastian, Spain
- Dpto. de Física Aplicada, EIG, UPV/EHU, 20018, San Sebastian, Spain
| | - M Ipatov
- Dpto. Física de Materiales, Fac. Químicas, UPV/EHU, 20018, San Sebastian, Spain
- Dpto. de Física Aplicada, EIG, UPV/EHU, 20018, San Sebastian, Spain
| | - J Gonzalez
- Dpto. Física de Materiales, Fac. Químicas, UPV/EHU, 20018, San Sebastian, Spain
| | - M Churyukanova
- National University of Science and Technology «MISIS», Moscow, 119049, Russia
| | - S Taskaev
- NRU South Ural State University, Chelyabinsk, 454080, Russia
| | - A Zhukov
- Dpto. Física de Materiales, Fac. Químicas, UPV/EHU, 20018, San Sebastian, Spain.
- Dpto. de Física Aplicada, EIG, UPV/EHU, 20018, San Sebastian, Spain.
- IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain.
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Zhukov A, Tomin N, Kurbatsky V, Sidorov D, Panasetsky D, Foley A. Ensemble methods of classification for power systems security assessment. Applied Computing and Informatics 2019. [DOI: 10.1016/j.aci.2017.09.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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6
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Zhukova V, Blanco JM, Ipatov M, Churyukanova M, Taskaev S, Zhukov A. Tailoring of magnetoimpedance effect and magnetic softness of Fe-rich glass-coated microwires by stress- annealing. Sci Rep 2018; 8:3202. [PMID: 29453403 PMCID: PMC5816593 DOI: 10.1038/s41598-018-21356-3] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 01/30/2018] [Indexed: 11/23/2022] Open
Abstract
There is a pressing need for improving of the high-frequency magneto-impedance effect of cost-effective soft magnetic materials for use in high-performance sensing devices. The impact of the stress-annealing on magnetic properties and high frequency impedance of Fe-rich glass-coated microwires was studied. Hysteresis loops of Fe-rich microwires have been considerably affected by stress- annealing. In stress-annealed Fe- rich microwire we obtained drastic decreasing of coercivity and change of character of hysteresis loop from rectangular to linear. By controlling stress-annealing conditions (temperature and time) we achieved drastic increasing (by order of magnitude) of giant magnetoimpedance ratio. Coercivity, remanent magnetization, diagonal and of-diagonal magnetoimpedance effect of Fe-rich microwires can be tuned by stress-annealing conditions: annealing temperature and time. Observed experimental results are discussed considering relaxation of internal stresses, compressive "back-stresses" arising after stress annealing and topological short range ordering.
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Affiliation(s)
- V Zhukova
- Dpto. Fisica de Materiales, Fac. Quimicas, UPV/EHU, 20018, San Sebastian, Spain
- Dpto. de Física Aplicada, EUPDS, UPV/EHU, 20018, San Sebastian, Spain
| | - J M Blanco
- Dpto. de Física Aplicada, EUPDS, UPV/EHU, 20018, San Sebastian, Spain
| | - M Ipatov
- Dpto. Fisica de Materiales, Fac. Quimicas, UPV/EHU, 20018, San Sebastian, Spain
- Dpto. de Física Aplicada, EUPDS, UPV/EHU, 20018, San Sebastian, Spain
| | - M Churyukanova
- National University of Science and Technology «MISIS», Moscow, 119049, Russia
| | - S Taskaev
- NRU South Ural State University, Chelyabinsk, 454080, Russia
| | - A Zhukov
- Dpto. Fisica de Materiales, Fac. Quimicas, UPV/EHU, 20018, San Sebastian, Spain.
- Dpto. de Física Aplicada, EUPDS, UPV/EHU, 20018, San Sebastian, Spain.
- IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain.
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Zhukov A, Ipatov M, Del Val JJ, Zhukova V, Chernenko VA. Magnetic and structural properties of glass-coated Heusler-type microwires exhibiting martensitic transformation. Sci Rep 2018; 8:621. [PMID: 29330513 PMCID: PMC5766560 DOI: 10.1038/s41598-017-19032-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 12/18/2017] [Indexed: 11/13/2022] Open
Abstract
We have studied magnetic and structural properties of the Heusler-type Ni-Mn-Ga glass-coated microwires prepared by Tailor-Ulitovsky technique. As-prepared sample presents magnetoresistance effect and considerable dependence of magnetization curves (particularly magnetization values) on magnetic field attributed to the magnetic and atomic disorder. Annealing strongly affects the temperature dependence of magnetization and Curie temperature of microwires. After annealing of the microwires at 973 K, the Curie temperature was enhanced to about 280 K which is beneficial for the magnetic solid state refrigeration. The observed hysteretic anomalies on the temperature dependences of resistance and magnetization in the as-prepared and annealed samples are produced by the martensitic transformation. The magnetoresistance and magnetocaloric effects have been investigated to illustrate a potential technological capability of studied microwires.
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Affiliation(s)
- A Zhukov
- Dpto. de Fís. Mater., UPV/EHU, San Sebastián, 20018, Spain. .,Dpto. de Física Aplicada, EUPDS, UPV/EHU, 20018, San Sebastian, Spain. .,IKERBASQUE, Basque Foundation for Science, 48013, Bilbao, Spain.
| | - M Ipatov
- Dpto. de Fís. Mater., UPV/EHU, San Sebastián, 20018, Spain.,Dpto. de Física Aplicada, EUPDS, UPV/EHU, 20018, San Sebastian, Spain
| | - J J Del Val
- Dpto. de Fís. Mater., UPV/EHU, San Sebastián, 20018, Spain
| | - V Zhukova
- Dpto. de Fís. Mater., UPV/EHU, San Sebastián, 20018, Spain.,Dpto. de Física Aplicada, EUPDS, UPV/EHU, 20018, San Sebastian, Spain
| | - V A Chernenko
- IKERBASQUE, Basque Foundation for Science, 48013, Bilbao, Spain.,BCMaterials & University of Basque Country (UPV/EHU), Bilbao, 48080, Spain.,Institute of Innovative Research (IIR), Tokyo Institute of Technology, 226-8503, Yokohama, Japan
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Talaat A, Alonso J, Zhukova V, Garaio E, García JA, Srikanth H, Phan MH, Zhukov A. Ferromagnetic glass-coated microwires with good heating properties for magnetic hyperthermia. Sci Rep 2016; 6:39300. [PMID: 27991557 PMCID: PMC5172374 DOI: 10.1038/srep39300] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Accepted: 11/01/2016] [Indexed: 11/22/2022] Open
Abstract
The heating properties of Fe71.7Si11B13.4Nb3Ni0.9 amorphous glass-coated microwires are explored for prospective applications in magnetic hyperthermia. We show that a single 5 mm long wire is able to produce a sufficient amount of heat, with the specific loss power (SLP) reaching a value as high as 521 W/g for an AC field of 700 Oe and a frequency of 310 kHz. The large SLP is attributed to the rectangular hysteresis loop resulting from a peculiar domain structure of the microwire. For an array of parallel microwires, we have observed an SLP improvement by one order of magnitude; 950 W/g for an AC field of 700 Oe. The magnetostatic interaction strength essential in the array of wires can be manipulated by varying the distance between the wires, showing a decreasing trend in SLP with increasing wire separation. The largest SLP is obtained when the wires are aligned along the direction of the AC field. The origin of the large SLP and relevant heating mechanisms are discussed.
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Affiliation(s)
- A Talaat
- Department of Physics, University of South Florida, Tampa, FL 33620, USA.,Dpto. Física de Materiales, UPV/EHU, 20018 San Sebastián, Spain.,Dpto. de Física Aplicada, EUPDS, UPV/EHU, 20018, San Sebastián, Spain
| | - J Alonso
- Department of Physics, University of South Florida, Tampa, FL 33620, USA.,BCMaterials Edificio N°. 500, Parque Tecnológico de Vizcaya, 48160, Derio, Bilbao, Spain
| | - V Zhukova
- Dpto. Física de Materiales, UPV/EHU, 20018 San Sebastián, Spain.,Dpto. de Física Aplicada, EUPDS, UPV/EHU, 20018, San Sebastián, Spain
| | - E Garaio
- Department of Electricity and Electronics, University of Basque Country, Leioa 48940, Spain
| | - J A García
- BCMaterials Edificio N°. 500, Parque Tecnológico de Vizcaya, 48160, Derio, Bilbao, Spain.,Department of Applied Physics II, University of Basque Country, Leioa 48940, Spain
| | - H Srikanth
- Department of Physics, University of South Florida, Tampa, FL 33620, USA
| | - M H Phan
- Department of Physics, University of South Florida, Tampa, FL 33620, USA
| | - A Zhukov
- Dpto. Física de Materiales, UPV/EHU, 20018 San Sebastián, Spain.,Dpto. de Física Aplicada, EUPDS, UPV/EHU, 20018, San Sebastián, Spain.,IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
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Semenova A, Agapov V, Evstifeev I, Shigaev M, Zhukov A. Trends of central and somatic rSO2 during cardiopulmonary bypass in adults and their interaction with cardiopulmonary bypass parameters. J Cardiothorac Vasc Anesth 2016. [DOI: 10.1053/j.jvca.2016.03.113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Kravets VG, Marshall OP, Nair RR, Thackray B, Zhukov A, Leng J, Grigorenko AN. Engineering optical properties of a graphene oxide metamaterial assembled in microfluidic channels. Opt Express 2015; 23:1265-75. [PMID: 25835885 DOI: 10.1364/oe.23.001265] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The dense packing of two dimensional flakes by van der Waals forces has enabled the creation of new metamaterials with desirable optical properties. Here we assemble graphene oxide sheets into a three dimensional metamaterial using a microfluidic technique and confirm their ordering via measurements of ellipsometric parameters, polarized optical microscopy, polarized transmission spectroscopy, infrared spectroscopy and scanning electron microscopy. We show that the produced metamaterials demonstrate strong in-plane optical anisotropy (Δn≈0.3 at n≈1.5-1.8) combined with low absorption (k<0.1) and compare them with as-synthesized samples of graphene oxide paper. Our results pave the way for engineered birefringent metamaterials on the basis of two dimensional atomic crystals including graphene and its derivatives.
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Stupakiewicz A, Chizhik A, Tekielak M, Zhukov A, Gonzalez J, Maziewski A. Direct imaging of the magnetization reversal in microwires using all-MOKE microscopy. Rev Sci Instrum 2014; 85:103702. [PMID: 25362398 DOI: 10.1063/1.4896758] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We report a method of imaging of the magnetization reversal process using analysis of real-time images of magnetic domain structures in cylindrically shaped microwires. This method uses wide-field polarizing optical microscopy and is based on the magneto-optical Kerr effect (MOKE). The aperture diaphragm in MOKE microscope was used to control the incident angles of the light rays that reached the non-planar surface of the microwire and also determined the MOKE geometries. The movement of the non-central position of the hole in this diaphragm leads to a change in the orientation of the plane of incidence of the light along the perpendicular or the parallel direction to the axial direction of the wire. The visualization of the surface magnetic domain structures is obtained using polar and longitudinal MOKE geometries. The hysteresis loops were obtained by plotting the averaged image contrast as a function of the external magnetic field. The separation of the all-magnetization components is performed using different MOKE geometries in a microscope. We demonstrate the use of vector magnetometry to analyze the orientation of the magnetization in a cylindrically shaped microwire under the influence of an external magnetic field.
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Affiliation(s)
- A Stupakiewicz
- Laboratory of Magnetism, Faculty of Physics, University of Bialystok, 15-424 Bialystok, Poland
| | - A Chizhik
- Universidad del País Vasco, UPV/EHU, San Sebastián, Spain
| | - M Tekielak
- Laboratory of Magnetism, Faculty of Physics, University of Bialystok, 15-424 Bialystok, Poland
| | - A Zhukov
- Universidad del País Vasco, UPV/EHU, San Sebastián, Spain
| | - J Gonzalez
- Universidad del País Vasco, UPV/EHU, San Sebastián, Spain
| | - A Maziewski
- Laboratory of Magnetism, Faculty of Physics, University of Bialystok, 15-424 Bialystok, Poland
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Gareeva F, Petrova N, Shenderova O, Zhukov A. Electrokinetic properties of detonation nanodiamond aggregates in aqueous KCl solutions. Colloids Surf A Physicochem Eng Asp 2014. [DOI: 10.1016/j.colsurfa.2012.08.055] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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13
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Chizhik A, Blanco J, Ipatov M, Zhukova V, Gonzalez J, Zhukov A. Domain walls collision in Fe-rich and Co-rich glass covered microwires. EPJ Web of Conferences 2013. [DOI: 10.1051/epjconf/20134017004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Zhukov A, Blanco JM, Ipatov M, Zhukova V. Magnetoelastic contribution in domain wall propagation of micrometric wires. J Nanosci Nanotechnol 2012; 12:7582-7586. [PMID: 23035521 DOI: 10.1166/jnn.2012.6550] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We report on studies of domain wall propagation of magnetically-bistable Fe-Co-rich microwires paying attention on the effect of applied and internal stresses. We measured magnetic domain propagation in various magnetic Fe-Co-rich amorphous microwires with metallic nucleus diameters (from 2.8 microm to 18 microm) using Sixtus Tonks-like experiments. We found that application of applied stresses and increasing of internal stresses result in decreasing of domain wall (DW) velocity. We assume that in order to achieve higher DW propagation velocity at the same magnetic field and enhanced DW mobility, special attention should be paid to the decrease of magnetoelastic energy.
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Affiliation(s)
- A Zhukov
- Dpto. Fisica de Materiales, Fac. Quimicas, UPV/EHU, 20009 San Sebastian, Spain
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Richter K, Varga R, Zhukov A. Influence of the magnetoelastic anisotropy on the domain wall dynamics in bistable amorphous wires. J Phys Condens Matter 2012; 24:296003. [PMID: 22738886 DOI: 10.1088/0953-8984/24/29/296003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We deal with the influence of the applied stress on the domain wall velocity in glass-coated magnetic microwires. In general, the domain wall velocity decreases with the applied tensile stress. Four regimes of the domain wall dynamics appear: (1) diffusion-damped, (2) a regime with variable domain wall width, (3) a viscous and (4) a vortex regime. Detailed analysis of domain wall parameters shows that the structural relaxation plays an important role even at ambient temperatures if high tensile stress is present. At higher fields (viscous regime), the most important damping arises from magnetic relaxation of magnetic moments. Finally, the domain wall velocity steeply increases (reaching a maximum at 7000 m s(-1)) in the vortex regime and so does the domain wall mobility.
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Affiliation(s)
- K Richter
- Institute of Physics, P J Safarik University, Park Angelinum 9, 041 54 Kosice, Slovakia
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Mayorov AS, Elias DC, Mucha-Kruczynski M, Gorbachev RV, Tudorovskiy T, Zhukov A, Morozov SV, Katsnelson MI, Geim AK, Novoselov KS. Interaction-Driven Spectrum Reconstruction in Bilayer Graphene. Science 2011; 333:860-3. [DOI: 10.1126/science.1208683] [Citation(s) in RCA: 236] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Zhukov A, García C, Del Val JJ, Gonzalez J, Knobel M, Serantes D, Baldomir D, Zhukova V. Studies of Fe-Cu microwires with nanogranular structure. J Phys Condens Matter 2009; 21:035301. [PMID: 21817277 DOI: 10.1088/0953-8984/21/3/035301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report on the fabrication, and structural and magnetic characterization of Cu(63)Fe(37) microwires with granular structure produced by rapid quenching, using the Tailor-Ulitovsky method, from the immiscible alloys. X-ray diffraction study demonstrated that the structure consists of small (6-45 nm) crystallites of Cu and body centred cubic α-Fe. Magnetic properties have been measured in the range of 5-300 K using a SQUID (superconducting quantum interference device) magnetometer. The temperature dependences of the magnetization measured in a cooling regime when no external magnetic field is applied (zero-field cooling) and in the presence of the field (field cooling) show considerable difference below 20 K. This difference could be related to the presence of small α-Fe grains embedded in the Cu matrix. Those α-Fe grains appear to be blocked at temperatures below that at which the maximum of the magnetization is observed in the low temperature range. Significant magnetoresistance (about 7%) has been found in the samples studied. The shape of the observed dependences is typical of a giant magnetoresistance effect.
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Affiliation(s)
- A Zhukov
- Department of Materials Physics, Faculty of Chemistry, PO Box 1072, 20080 San Sebastian, Spain. TAMAG Ibérica SL, Parque Tecnológico de Miramón, Paseo Mikeletegi 56, 1a Planta, 20009 San Sebastián, Spain
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Chubykalo-Fesenko O, Gonzalez J, Hernando B, Zhukov A. Nanomagnetism. J Nanosci Nanotechnol 2008; 8:2729. [PMID: 18681011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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21
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Kovsh A, Krestnikov I, Livshits D, Mikhrin S, Weimert J, Zhukov A. Quantum dot laser with 75 nm broad spectrum of emission. Opt Lett 2007; 32:793-5. [PMID: 17339939 DOI: 10.1364/ol.32.000793] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
We report on a quantum dot laser having an emission spectrum as broad as 74.9 nm at 25 degrees C in the 1.2-1.28 wavelength interval with a total pulsed output power of 750 mW in single lateral mode regime and the average spectral power density of >10 mW/nm. A significant overlap and approximate equalization of the ground-state and the excited-state emission bands in the laser's spectrum is achieved by means of intentional inhomogeneous broadening of the quantum dot energy levels.
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Affiliation(s)
- A Kovsh
- NL Nanosemiconductor GmbH, Dortmund, Germany
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García C, Zhukova V, Zhukov A, Usov N, Ipatov M, Gonzalez J, Blanco JM. Effect of Interaction on Giant Magnetoimpedance Effect in a System of Few Thin Wires. ACTA ACUST UNITED AC 2007. [DOI: 10.1166/sl.2007.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Renk KF, Stahl BI, Rogl A, Janzen T, Pavel'ev DG, Koshurinov YI, Ustinov V, Zhukov A. Subterahertz superlattice parametric oscillator. Phys Rev Lett 2005; 95:126801. [PMID: 16197096 DOI: 10.1103/physrevlett.95.126801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2004] [Indexed: 05/04/2023]
Abstract
We report a superlattice parametric oscillator (SPO), with a GaAs/AlAs superlattice as the active element. The SPO was pumped by a microwave field (power 4 mW) and produced third harmonic radiation at subterahertz frequencies (near 300 GHz; 0.1 mW). We attribute the parametric gain to the nonlinearity of the miniband transport.
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Affiliation(s)
- K F Renk
- Institut für Angewandte Physik, Universität Regensburg, 93040 Regensburg, Germany.
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Werlinder V, Backlund M, Zhukov A, Ingelman-Sundberg M. Transcriptional and post-translational regulation of CYP1A1 by primaquine. J Pharmacol Exp Ther 2001; 297:206-14. [PMID: 11259546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
Regulation of the CYP1A1 gene has been shown to involve the aryl hydrocarbon receptor and the CYP1A1 gene expression is induced by AhR ligands. Primaquine is an antimalarial agent that does not exhibit the structural properties of a classical AhR ligand. We have evaluated the mechanisms by which this compound induces CYP1A1 expression using rat hepatoma H4IIE cells and V79 cells stably expressing CYP1A1. In H4IIE cells, primaquine caused a time- and dose-dependent increase of CYP1A1 mRNA and protein expression. The transcriptional activation of the CYP1A1 gene by primaquine was strictly XRE-dependent, as shown by transfection of different CYP1A1 pGL3 reporter constructs in H4IIE cells, and the involvement of the AhR was shown by activation of a Gal4-AhR hybrid protein by primaquine in transfected cells. Furthermore, primaquine caused transformation of the cytosolic AhR to a DNA-binding form, in vitro, suggesting that primaquine directly activates the receptor complex. In addition to its action at the transcriptional level, primaquine caused a dose-dependent inhibition of CYP1A1 degradation with an IC(50) of 3.3 , as seen in mammalian V79 cells. This was not due to the lysosomotropic activity of the drug since other lysosomotropic agents were ineffective. Primaquine formed a type II binding spectrum with CYP1A1 and inhibited the CYP1A1-dependent ethoxyresorufin O-deethylase activity in vitro with a K(i) of 1.3 microM, which is close to the IC(50), suggesting that the drug protects CYP1A1 from degradation by binding at the active site. It is concluded that CYP1A1 is regulated by primaquine both on the transcriptional as well as on a post-translational level.
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Affiliation(s)
- V Werlinder
- Division of Molecular Toxicology, Institute of Environmental Medicine, Karolinska Institutet, SE-171 77 Stockholm, Sweden
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Hales J, Zhukov A, Roy R, Dykman MI. Dynamics of activated escape and its observation in a semiconductor laser. Phys Rev Lett 2000; 85:78-81. [PMID: 10991163 DOI: 10.1103/physrevlett.85.78] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2000] [Indexed: 05/22/2023]
Abstract
We report a direct experimental observation and provide a theory of the distribution of trajectories along which a fluctuating system moves over a potential barrier in escape from a metastable state. The experimental results are obtained for a semiconductor laser with optical feedback. The distribution of paths displays a distinct peak, which shows how the escaping system is most likely to move. We argue that the specific features of this distribution may give an insight into the nature of dropout events in lasers.
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Affiliation(s)
- J Hales
- CREOL, University of Central Florida, Orlando, Florida 32816, USA
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Zhukov A, Ingelman-Sundberg M. Relationship between cytochrome P450 catalytic cycling and stability: fast degradation of ethanol-inducible cytochrome P450 2E1 (CYP2E1) in hepatoma cells is abolished by inactivation of its electron donor NADPH-cytochrome P450 reductase. Biochem J 1999; 340 ( Pt 2):453-8. [PMID: 10333489 PMCID: PMC1220271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Ethanol-inducible cytochrome P450 2E1 (CYP2E1) involved in the metabolism of gluconeogenetic precursors and some cytotoxins is distinguished from other cytochrome P450 enzymes by its rapid turnover (in vivo half-life of 4-7 h), with ligands to the haem iron, both substrates and inhibitors, stabilizing the protein. CYP2E1 is also known to have a high oxidase activity in the absence of substrate, resulting in the production of reactive oxygen radicals. We suggested that the rapid intracellular turnover of the enzyme may be partly due to covalent modifications by such radicals or to other changes during catalytic cycling, in which case the inhibition of electron supply from NADPH-cytochrome P450 reductase would be expected to stabilize the protein. Fao hepatoma cells, where CYP2E1 showed a half-life of 4 h upon serum withdrawal, were treated for 1 h with 0.3 microM diphenylene iodonium (DPI), a suicide inhibitor of flavoenzymes, which resulted in approximately 90% inhibition of the microsomal NADPH-cytochrome P450 reductase and CYP2E1-dependent chlorzoxazone hydroxylase activities. Subsequent cycloheximide chase revealed that the CYP2E1 half-life increased to 26 h. Neither the degradation rates of total protein, CYP2B1 and NADPH-cytochrome P450 reductase nor the cellular ATP level were affected by DPI under the conditions employed. These results demonstrate for the first time that the short half-life of CYP2E1 in vivo may be largely due to the rapid destabilization of the enzyme during catalytic cycling rather than to the intrinsic instability of the protein molecule.
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Affiliation(s)
- A Zhukov
- Division of Molecular Toxicology, Institute of Environmental Medicine, Karolinska Institutet, S-171 77 Stockholm, Sweden.
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Zhukov A, Vázquez M, García-Beneytez JM. Magnetoelastic sensor for signature identification based on mechanomagnetic effect in amorphous wires. ACTA ACUST UNITED AC 1998. [DOI: 10.1051/jp4:19982176] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Zhukov A, Ingelman-Sundberg M. Selective fast degradation of cytochrome P-450 2E1 in serum-deprived hepatoma cells by a mechanism sensitive to inhibitors of vesicular transport. Eur J Biochem 1997; 247:37-43. [PMID: 9249006 DOI: 10.1111/j.1432-1033.1997.00037.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Cytochrome P-450 2E1 (CYP2E1) is characterized by a rapid turnover in the liver and some cell lines and the ability of substrates and heme iron ligands to inhibit significantly enzyme degradation. In the Fao hepatoma cell line, CYP2E1 was found to be fairly stable (half-life of 26 h), but serum withdrawal resulted in its rapid disappearance from the microsomal fraction (half-life of about 7 h) as evaluated using cycloheximide chase. The effect of serum withdrawal could be partially reversed by the addition of albumin to the culture medium, whereas insulin and the insulin-like growth factor IGF-I had no additional effect. The effect of serum withdrawal was specific for CYP2E1 since (a) no concomitant fast degradation of CYP2B1 and NADPH-cytochrome P-450 reductase was observed and (b) the CYP2E1 ligands ethanol and imidazole prevented the fast degradation of the enzyme. The lysosomotropic agent ammonium chloride and the inhibitor of autophagocytosis 3-methyladenine slowed down CYP2E1 degradation by about 30%, while leupeptin had no effect. Under the same conditions, the degradation of total long-lived cell protein showed the same sensitivity to ammonium chloride, but was significantly less sensitive to 3-methyladenine and serum and not sensitive to ethanol and imidazole. CYP2E1 degradation was inhibited by combined treatment with brefeldin A and nocodazole, which blocks both anterograde and retrograde vesicular transport between endoplasmic reticulum and the Golgi apparatus. The data point to the existence of a selective mechanism for the degradation of membrane proteins in serum-deprived cells in addition to nonselective autophagocytosis. The selective degradation of CYP2E1 may be attained by means of its selective vesicular transport to an acidic post-endoplasmic reticulum compartment.
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Affiliation(s)
- A Zhukov
- Institute of Environmental Medicine, Division of Molecular Toxicology, Karolinska Institutet, Stockholm, Sweden
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Abstract
Hepsin, a putative cell-surface serine proteinase, has been isolated from the microsomal membranes of rat liver and purified to homogeneity by hydroxyapatite, DEAE-Sepharose, and benzamidine-Sepharose chromatography. The course of purification was monitored using antibodies raised against a 20-mer peptide at the C-terminus of rat hepsin, and the identity of the purified protein was confirmed by partial amino-acid sequencing. A single-chain precursor of ca. 50 kDa found in the microsomes underwent spontaneous maturation in the course of purification so that the last, affinity chromatography, step recovered only the mature form which dissociated to subunits of 31 and 19 kDa under reducing SDS-PAGE. Proteinase digestion experiments with microsomal vesicles are consistent with the luminal orientation of the precursor C-terminus, which would result in its extracellular orientation upon transportation to the cell surface. [3H]diisopropylfluorophosphate covalently binds to the large subunit showing it to be the catalytic one. The N-terminal sequencing of this subunit demonstrates that the zymogen is converted to the active serine proteinase by cleavage at the Arg161-Ile162 site. Activity measurements with short synthetic peptides show that the enzyme cleaves after basic amino-acid residues, Arg being preferable to Lys. The inhibition pattern is typical of trypsin-like serine proteinases. The pH-dependence of activity within the range pH 6-9 has no maximum, the activity increasing continuously with pH. These results are consistent with the earlier predictions based on hepsin amino-acid sequence and elucidate the specificity and other earlier unknown enzymatic and molecular properties of the enzyme.
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Affiliation(s)
- A Zhukov
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
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Arcas J, Gómez-Polo C, Zhukov A, Vázquez M, Larin V, Hernando A. Magnetic properties of amorphous and devitrified FeSiBCuNb glass-coated microwires. ACTA ACUST UNITED AC 1996. [DOI: 10.1016/s0965-9773(96)00054-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Zhukov A, Werlinder V, Ingelman-Sundberg M. Purification and characterization of two membrane bound serine proteinases from rat liver microsomes active in degradation of cytochrome P450. Biochem Biophys Res Commun 1993; 197:221-8. [PMID: 8250928 DOI: 10.1006/bbrc.1993.2464] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Two serine proteinases capable of digesting cytochrome P4502E1 (CYP2E1) have been purified from sodium cholate solubilized rat liver microsomal membranes. After chromatography on hydroxyapatite, DEAE-Sepharose chromatography resolved the CYP2E1-degrading activity into two peaks, and the two proteinases were finally purified on benzamidine-Sepharose. Both have a M(r) of 32,000 on SDS-PAGE, are optimally active at pH 8, and show a susceptibility to inhibitors typical of serine proteinases. CYP2E1 degradation patterns exhibited by the proteinases are identical to each other and similar to that observed during the proteolysis of endogenous CYP2E1 in the microsomal membranes, which indicates that the proteinases can degrade CYP2E1 in its native environment. We suggest a role of these proteinases in the rapid phase of cytochrome P450 degradation in the endoplasmic reticulum.
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Affiliation(s)
- A Zhukov
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
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