The Experts below are selected from a list of 3483 Experts worldwide ranked by ideXlab platform
Christoph Vogler - One of the best experts on this subject based on the ideXlab platform.
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3d print of polymer bonded rare earth magnets and 3d magnetic field scanning with an end user 3d printer
Applied Physics Letters, 2016Co-Authors: Christian Huber, O. Muthsam, K. Sirak, R. Thanhoffer, Claas Abert, Martin Groenefeld, F Bruckner, Stephan Schuschnigg, Iulian Teliban, Christoph VoglerAbstract:3D print is a recently developed technique, for single-unit production, and for structures that have been impossible to build previously. The current work presents a method to 3D print polymer bonded isotropic hard magnets with a low-cost, end-user 3D printer. Commercially available isotropic NdFeB powder inside a PA11 matrix is characterized, and prepared for the printing process. An example of a printed magnet with a complex shape that was designed to generate a specific stray field is presented, and compared with finite element simulation solving the Macroscopic Maxwell equations. For magnetic characterization, and comparing 3D printed structures with injection molded parts, hysteresis measurements are performed. To measure the stray field outside the magnet, the printer is upgraded to a 3D magnetic flux density measurement system. To skip an elaborate adjusting of the sensor, a simulation is used to calibrate the angles, sensitivity, and the offset of the sensor. With this setup, a measurement resolut...
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3D print of polymer bonded rare-earth magnets, and 3D magnetic field scanning with an end-user 3D printer
Applied Physics Letters, 2016Co-Authors: Christian Huber, O. Muthsam, K. Sirak, R. Thanhoffer, Claas Abert, Martin Groenefeld, F Bruckner, Stephan Schuschnigg, Iulian Teliban, Christoph VoglerAbstract:3D print is a recently developed technique, for single-unit production, and for structures that have been impossible to build previously. The current work presents a method to 3D print polymer bonded isotropic hard magnets with a low-cost, end-user 3D printer. Commercially available isotropic NdFeB powder inside a PA11 matrix is characterized, and prepared for the printing process. An example of a printed magnet with a complex shape that was designed to generate a specific stray field is presented, and compared with finite element simulation solving the Macroscopic Maxwell equations. For magnetic characterization, and comparing 3D printed structures with injection molded parts, hysteresis measurements are performed. To measure the stray field outside the magnet, the printer is upgraded to a 3D magnetic flux density measurement system. To skip an elaborate adjusting of the sensor, a simulation is used to calibrate the angles, sensitivity, and the offset of the sensor. With this setup a measurement resolution of 0.05\,mm along the z-axes is achievable. The effectiveness of our novel calibration method is shown. With our setup we are able to print polymer bonded magnetic systems with the freedom of having a specific complex shape with locally tailored magnetic properties. The 3D scanning setup is easy to mount, and with our calibration method we are able to get accurate measuring results of the stray field.
Radomir I Slavchov - One of the best experts on this subject based on the ideXlab platform.
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the polarized interface between quadrupolar insulators Maxwell stress tensor surface tension and potential
Journal of Chemical Physics, 2015Co-Authors: Radomir I Slavchov, Iglika M Dimitrova, Tzanko IvanovAbstract:The quadrupolar Maxwell electrostatic equations predict several qualitatively different results compared to Poisson’s classical equation in their description of the properties of a dielectric interface. All interfaces between dielectrics possess surface dipole moment which results in a measurable surface potential jump. The surface dipole moment is conjugated to the bulk quadrupole moment density (the quadrupolarization) similarly to Gauss’s relation between surface charge and bulk polarization. However, the classical Macroscopic Maxwell equations completely neglect the quadrupolarization of the medium. Therefore, the electrostatic potential distribution near an interface of intrinsic dipole moment can be correctly described only within the quadrupolar Macroscopic equations of electrostatics. They predict that near the polarized interface a diffuse dipole layer exists, which bears many similarities to the diffuse charge layer near a charged surface, in agreement with existing molecular dynamics simulation data. It turns out that when the quadrupole terms are kept in the multipole expansion of the laws of electrostatics, the solutions for the potential and the electric field are continuous functions at the surface. A well-defined surface electric field exists, interacting with the adsorbed dipoles. This allows for a Macroscopic description of the surface dipole-surface dipole and the surface dipole-bulk quadrupole interactions. They are shown to have considerable contribution to the interfacial tension—of the order of tens of mN/m! To evaluate it, the Maxwell stress tensor in quadrupolar medium is deduced, including the electric field gradient action on the quadrupoles, as well as quadrupolar image force and quadrupolar electrostriction. The dependence of the interfacial tension on the external normal electric field (the dielectrocapillary curve) is predicted and the dielectric susceptibility of the dipolar double layer is related to the quadrupolarizabilities of the bulk phases and the intrinsic polarization of the interface. The coefficient of the dielectro-Marangoni effect (surface flow due to gradient of the normal electric field) is found. A model of the Langevin type for the surface dipole moment and the intrinsic surface polarizability is presented.
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quadrupole terms in the Maxwell equations debye huckel theory in quadrupolarizable solvent and self salting out of electrolytes
Journal of Chemical Physics, 2014Co-Authors: Radomir I SlavchovAbstract:If the molecules of a given solvent possess significant quadrupolar moment, the Macroscopic Maxwell equations must involve the contribution of the density of the quadrupolar moment to the electric displacement field. This modifies the Poisson-Boltzmann equation and all consequences from it. In this work, the structure of the diffuse atmosphere around an ion dissolved in quadrupolarizable medium is analyzed by solving the quadrupolar variant of the Coulomb-Ampere's law of electrostatics. The results are compared to the classical Debye-Huckel theory. The quadrupolar version of the Debye-Huckel potential of a point charge is finite even in r = 0. The ion-quadrupole interaction yields a significant expansion of the diffuse atmosphere of the ion and, thus, it decreases the Debye-Huckel energy. In addition, since the dielectric permittivity of the electrolyte solutions depends strongly on concentration, the Born energy of the dissolved ions alters with concentration, which has a considerable contribution to the activity coefficient γ± known as the self-salting-out effect. The quadrupolarizability of the medium damps strongly the self-salting-out of the electrolyte, and thus it affects additionally γ±. Comparison with experimental data for γ± for various electrolytes allows for the estimation of the quadrupolar length of water: LQ ≈ 2 A, in good agreement with previous assessments. The effect of quadrupolarizability is especially important in non-aqueous solutions. Data for the activity of NaBr in methanol is used to determine the quadrupolarizability of methanol with good accuracy.
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quadrupole terms in the Maxwell equations debye huckel theory in quadrupolarizable solvent and self salting out of electrolytes
Journal of Chemical Physics, 2014Co-Authors: Radomir I SlavchovAbstract:If the molecules of a given solvent possess significant quadrupolar moment, the Macroscopic Maxwell equations must involve the contribution of the density of the quadrupolar moment to the electric displacement field. This modifies the Poisson-Boltzmann equation and all consequences from it. In this work, the structure of the diffuse atmosphere around an ion dissolved in quadrupolarizable medium is analyzed by solving the quadrupolar variant of the Coulomb-Ampere's law of electrostatics. The results are compared to the classical Debye-Huckel theory. The quadrupolar version of the Debye-Huckel potential of a point charge is finite even in r = 0. The ion-quadrupole interaction yields a significant expansion of the diffuse atmosphere of the ion and, thus, it decreases the Debye-Huckel energy. In addition, since the dielectric permittivity of the electrolyte solutions depends strongly on concentration, the Born energy of the dissolved ions alters with concentration, which has a considerable contribution to the...
Christian Huber - One of the best experts on this subject based on the ideXlab platform.
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3d print of polymer bonded rare earth magnets and 3d magnetic field scanning with an end user 3d printer
Applied Physics Letters, 2016Co-Authors: Christian Huber, O. Muthsam, K. Sirak, R. Thanhoffer, Claas Abert, Martin Groenefeld, F Bruckner, Stephan Schuschnigg, Iulian Teliban, Christoph VoglerAbstract:3D print is a recently developed technique, for single-unit production, and for structures that have been impossible to build previously. The current work presents a method to 3D print polymer bonded isotropic hard magnets with a low-cost, end-user 3D printer. Commercially available isotropic NdFeB powder inside a PA11 matrix is characterized, and prepared for the printing process. An example of a printed magnet with a complex shape that was designed to generate a specific stray field is presented, and compared with finite element simulation solving the Macroscopic Maxwell equations. For magnetic characterization, and comparing 3D printed structures with injection molded parts, hysteresis measurements are performed. To measure the stray field outside the magnet, the printer is upgraded to a 3D magnetic flux density measurement system. To skip an elaborate adjusting of the sensor, a simulation is used to calibrate the angles, sensitivity, and the offset of the sensor. With this setup, a measurement resolut...
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3D print of polymer bonded rare-earth magnets, and 3D magnetic field scanning with an end-user 3D printer
Applied Physics Letters, 2016Co-Authors: Christian Huber, O. Muthsam, K. Sirak, R. Thanhoffer, Claas Abert, Martin Groenefeld, F Bruckner, Stephan Schuschnigg, Iulian Teliban, Christoph VoglerAbstract:3D print is a recently developed technique, for single-unit production, and for structures that have been impossible to build previously. The current work presents a method to 3D print polymer bonded isotropic hard magnets with a low-cost, end-user 3D printer. Commercially available isotropic NdFeB powder inside a PA11 matrix is characterized, and prepared for the printing process. An example of a printed magnet with a complex shape that was designed to generate a specific stray field is presented, and compared with finite element simulation solving the Macroscopic Maxwell equations. For magnetic characterization, and comparing 3D printed structures with injection molded parts, hysteresis measurements are performed. To measure the stray field outside the magnet, the printer is upgraded to a 3D magnetic flux density measurement system. To skip an elaborate adjusting of the sensor, a simulation is used to calibrate the angles, sensitivity, and the offset of the sensor. With this setup a measurement resolution of 0.05\,mm along the z-axes is achievable. The effectiveness of our novel calibration method is shown. With our setup we are able to print polymer bonded magnetic systems with the freedom of having a specific complex shape with locally tailored magnetic properties. The 3D scanning setup is easy to mount, and with our calibration method we are able to get accurate measuring results of the stray field.
O. Muthsam - One of the best experts on this subject based on the ideXlab platform.
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3d print of polymer bonded rare earth magnets and 3d magnetic field scanning with an end user 3d printer
Applied Physics Letters, 2016Co-Authors: Christian Huber, O. Muthsam, K. Sirak, R. Thanhoffer, Claas Abert, Martin Groenefeld, F Bruckner, Stephan Schuschnigg, Iulian Teliban, Christoph VoglerAbstract:3D print is a recently developed technique, for single-unit production, and for structures that have been impossible to build previously. The current work presents a method to 3D print polymer bonded isotropic hard magnets with a low-cost, end-user 3D printer. Commercially available isotropic NdFeB powder inside a PA11 matrix is characterized, and prepared for the printing process. An example of a printed magnet with a complex shape that was designed to generate a specific stray field is presented, and compared with finite element simulation solving the Macroscopic Maxwell equations. For magnetic characterization, and comparing 3D printed structures with injection molded parts, hysteresis measurements are performed. To measure the stray field outside the magnet, the printer is upgraded to a 3D magnetic flux density measurement system. To skip an elaborate adjusting of the sensor, a simulation is used to calibrate the angles, sensitivity, and the offset of the sensor. With this setup, a measurement resolut...
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3D print of polymer bonded rare-earth magnets, and 3D magnetic field scanning with an end-user 3D printer
Applied Physics Letters, 2016Co-Authors: Christian Huber, O. Muthsam, K. Sirak, R. Thanhoffer, Claas Abert, Martin Groenefeld, F Bruckner, Stephan Schuschnigg, Iulian Teliban, Christoph VoglerAbstract:3D print is a recently developed technique, for single-unit production, and for structures that have been impossible to build previously. The current work presents a method to 3D print polymer bonded isotropic hard magnets with a low-cost, end-user 3D printer. Commercially available isotropic NdFeB powder inside a PA11 matrix is characterized, and prepared for the printing process. An example of a printed magnet with a complex shape that was designed to generate a specific stray field is presented, and compared with finite element simulation solving the Macroscopic Maxwell equations. For magnetic characterization, and comparing 3D printed structures with injection molded parts, hysteresis measurements are performed. To measure the stray field outside the magnet, the printer is upgraded to a 3D magnetic flux density measurement system. To skip an elaborate adjusting of the sensor, a simulation is used to calibrate the angles, sensitivity, and the offset of the sensor. With this setup a measurement resolution of 0.05\,mm along the z-axes is achievable. The effectiveness of our novel calibration method is shown. With our setup we are able to print polymer bonded magnetic systems with the freedom of having a specific complex shape with locally tailored magnetic properties. The 3D scanning setup is easy to mount, and with our calibration method we are able to get accurate measuring results of the stray field.
R. Thanhoffer - One of the best experts on this subject based on the ideXlab platform.
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3d print of polymer bonded rare earth magnets and 3d magnetic field scanning with an end user 3d printer
Applied Physics Letters, 2016Co-Authors: Christian Huber, O. Muthsam, K. Sirak, R. Thanhoffer, Claas Abert, Martin Groenefeld, F Bruckner, Stephan Schuschnigg, Iulian Teliban, Christoph VoglerAbstract:3D print is a recently developed technique, for single-unit production, and for structures that have been impossible to build previously. The current work presents a method to 3D print polymer bonded isotropic hard magnets with a low-cost, end-user 3D printer. Commercially available isotropic NdFeB powder inside a PA11 matrix is characterized, and prepared for the printing process. An example of a printed magnet with a complex shape that was designed to generate a specific stray field is presented, and compared with finite element simulation solving the Macroscopic Maxwell equations. For magnetic characterization, and comparing 3D printed structures with injection molded parts, hysteresis measurements are performed. To measure the stray field outside the magnet, the printer is upgraded to a 3D magnetic flux density measurement system. To skip an elaborate adjusting of the sensor, a simulation is used to calibrate the angles, sensitivity, and the offset of the sensor. With this setup, a measurement resolut...
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3D print of polymer bonded rare-earth magnets, and 3D magnetic field scanning with an end-user 3D printer
Applied Physics Letters, 2016Co-Authors: Christian Huber, O. Muthsam, K. Sirak, R. Thanhoffer, Claas Abert, Martin Groenefeld, F Bruckner, Stephan Schuschnigg, Iulian Teliban, Christoph VoglerAbstract:3D print is a recently developed technique, for single-unit production, and for structures that have been impossible to build previously. The current work presents a method to 3D print polymer bonded isotropic hard magnets with a low-cost, end-user 3D printer. Commercially available isotropic NdFeB powder inside a PA11 matrix is characterized, and prepared for the printing process. An example of a printed magnet with a complex shape that was designed to generate a specific stray field is presented, and compared with finite element simulation solving the Macroscopic Maxwell equations. For magnetic characterization, and comparing 3D printed structures with injection molded parts, hysteresis measurements are performed. To measure the stray field outside the magnet, the printer is upgraded to a 3D magnetic flux density measurement system. To skip an elaborate adjusting of the sensor, a simulation is used to calibrate the angles, sensitivity, and the offset of the sensor. With this setup a measurement resolution of 0.05\,mm along the z-axes is achievable. The effectiveness of our novel calibration method is shown. With our setup we are able to print polymer bonded magnetic systems with the freedom of having a specific complex shape with locally tailored magnetic properties. The 3D scanning setup is easy to mount, and with our calibration method we are able to get accurate measuring results of the stray field.
