China
Africa
Explore chapters and articles related to this topic
Magnetic Separation of Micro- and Nanoparticles for Water Treatment Processes
Published in Olayinka I. Ogunsola, Isaac K. Gamwo, Solid–Liquid Separation Technologies, 2022
Jenifer Gómez-Pastora, Xian Wu, Jeffrey J. Chalmers
As can be observed in Table 10.1, the filters are generally magnetized with electromagnets and superconducting magnets. The disadvantage of electromagnets is the energy loss due to Joule effect, which can be overcome by the use of superconducting magnets [21]; these can produce strong magnetic fields, as seen in Table 10.1. Conversely, the use of superconducting magnets, while effectively having no heat loss, require prohibitively expensive cryogenic cooling systems [10]. Because of this challenge, a number of studies have investigated the feasibility of HGMS using permanent magnets as the source field, obtaining promising efficiency results while reducing the electrical usage and improving the system portability [17,21]. However, the design of switchable permanent magnets (necessary for the rinsing of the matrix and to recover the particles) is challenging [10]. Regarding the matrix elements, the most popular material is stainless steel wool, although recent studies have addressed the possibility of using ferromagnetic membranes [17] or supported magnetite composites [15].
Unable to Resist
Published in Sharon Ann Holgate, Understanding Solid State Physics, 2021
Superconducting magnets are also used in particle accelerators to guide the charged particles along a particular path, and as storage devices for electric power. Many of these superconducting electromagnets are made from niobium–titanium alloys because, unlike most of the high-temperature superconductors discovered so far, they can be formed into wires.
Magnetic Resonance Imaging
Published in Ravishankar Chityala, Sridevi Pudipeddi, Image Processing and Acquisition using Python, 2020
Ravishankar Chityala, Sridevi Pudipeddi
The magnets could be permanent magnets, electromagnets or superconducting magnets. An important criterion for choosing a magnet is its ability to produce a uniform magnetic field. Permanent magnets are cheaper but the magnetic field is not uniform. Electromagnets can be manufactured to close tolerance, so that the magnetic field is uniform. They generate a lot of heat, which limits the magnetic field strength. Superconducting magnets are electromagnets that are cooled by superconducting fluids such as liquid nitrogen or helium. These magnets have a homogeneous magnetic field and high field strength but they are expensive to operate.
A segregated spectral element method for thermomagnetic convection of paramagnetic fluid in rectangular enclosures with sinusoidal temperature distribution on one side wall
Published in Numerical Heat Transfer, Part A: Applications, 2019
Wenqiang He, Guoliang Qin, Yazhou Wang, Zhenzhong Bao
With the advent of high-temperature superconducting magnet, strong magnetic field in the order of several tesla or more has been available in the laboratory. The study of thermomagnetic convection of nonferrous materials such as air, water, and others has become attractive, in which the magnetic force is employed to control the fluid flow and heat transfer. Braithwaite et al. [1] investigated both the enhancement and suppression of thermal-convection of paramagnetic fluids due to an inhomogeneous magnetic field in the Rayleigh-Bénard system. Wakayama and coworkers [2,3] theoretically and numerically examined the mechanism of thermomagnetic convection in two-dimensional enclosures with an electrically non-conducting or low-conducting fluid. Tagawa et al. [4,5] reported the thermomagnetic convection of nonferrous materials in a cubic enclosure and derived a model equation using a method similar to the Boussinesq approximation. Akamatsu et al. [6] studied the control of aerial flow in a cylindrical enclosure heated by the vertical wall and cooled by the horizontal walls with an external magnetic field. Jiang et al. [7] numerically simulated the thermomagnetic convection of air in a porous rectangular enclosure and investigated the heat transfer characteristics with and without gravitational field.
Feldspar Purification from Iron Impurities: A Review of Treatment Methods
Published in Mineral Processing and Extractive Metallurgy Review, 2023
Fatima Baila, Tariq Labbilta, Yassine Darmane
Various advantages can be brought by superconducting magnet technologies with cryogenic system, among others, they are provided by helium-based cooling systems to ensure the proper functioning of the superconducting coils, they reduce the dissipation of electrical energy, since superconductors are electrically irresistive, i.e. the whole electrical energy is dedicated to powering the magnet. Additionally, superconducting coils allow much higher magnetic fields than resistive systems and are practically flexible and easy to install (Gillet, Diot, et Joussemet 2000).
Likely U.S. Regulatory Considerations for D-T Fusion Power Reactors
Published in Fusion Science and Technology, 2020
Robert L. Hirsch, Gerald L. Kulcinski, Doug Chapin, Herman Diekamp
Superconducting magnets represent marvelous technology, providing high-steady-state magnetic fields via special conducting wire/cables, charged once with direct-current (dc) electric power after which they are trickle charged for lead losses. Superconducting magnets are widely used in MRI devices, particle accelerators, and various laboratory equipment. Today’s technology demands continuous cooling with liquid helium to maintain the magnets below the critical temperatures of the superconducting wire/cables, housed in special insulating dewars.