Magnetic Poles Research Articles

A Relational Approach to Event Sustainability: Applying Actor‐Network Theory and Foucauldian Discourse Analysis to a Music Event

The framing of event sustainability should go beyond the greening of specific events and the event sector. Based on a relational approach, we used actor‐network theory and Foucauldian discourse analysis to investigate the debate on a music event sustainability. We collected and discursively analyzed online newspapers and social media data regarding this event’s sustainability. The findings showed a polarized discourse characterized by conflicting views on, for example, nature, and three missing discourses–academic, local community, nonhuman–which we identified as alternative discourses and leverage points for greater sustainability. These findings allowed us to conceptualize event sustainability as a catalyzing network of actors, ideas, and relationships attracted to magnetic poles powered by different understandings of central concepts. This study proposes an understanding of event sustainability in relational terms and its contribution resides in the combination of actor‐network theory and Foucauldian discourse analysis as a possible approach to such understanding.

Atmospheric heating and magnetism driven by 22Ne distillation in isolated white dwarfs

The origin of atmospheric heating in the cool, magnetic white dwarf GD 356 remains unsolved nearly 40 years after its discovery. This once idiosyncratic star with Teff ≈ 7500 K, yet Balmer lines in Zeeman-split emission is now part of a growing class of white dwarfs exhibiting similar features, and which are tightly clustered in the HR diagram suggesting an intrinsic power source. This paper proposes that convective motions associated with an internal dynamo can power electric currents along magnetic field lines that heat the atmosphere via Ohmic dissipation. Such currents would require a dynamo driven by core 22Ne distillation, and would further corroborate magnetic field generation in white dwarfs by this process. The model predicts that the heating will be highest near the magnetic poles, and virtually absent toward the equator, in agreement with observations. This picture is also consistent with the absence of X-ray or extreme ultraviolet emission, because the resistivity would decrease by several orders of magnitude at the typical coronal temperatures. The proposed model suggests that i) DAHe stars are mergers with enhanced 22Ne that enables distillation and may result in significant cooling delays; and ii) any mergers that distill neon will generate magnetism and chromospheres. The predicted chromospheric emission is consistent with the two known massive DQe white dwarfs.

Analysis of the Eddy current of water heating device to convert wind energy directly into heat: Case study maldo island, South Korea

The Eddy Current of Water Heating (ECWH) system introduces a pioneering approach for converting wind energy into heat, marking a significant step in renewable energy technology. The current study focuses on refining the ECWH system by evaluating eight distinct heat generator models. Each model is selected based on its magnet configurations and pole numbers to maximize power efficiency at rotational speeds ranging from 100 to 500 rpm. This selection strategy is designed to provide a deep understanding of not only system efficiency across a spectrum of technical specifications but also the practical limitations of experimental research considerations. Energy efficiency is thoroughly analyzed for four models over a power input range of 120 to 2193 W. Wind speed data collected over a year from Maldo Island, west coast of South Korea, simulates the Weibull distribution of wind speeds and estimates total power production by employing the QBlade software. This study aims to explore the practicality of converting wind's kinetic energy directly into thermal energy through the ECWH system. Our findings indicate that the ECWH system outperforms conventional permanent magnet alternators, particularly in its ability to generate more power at lower angular velocities and wind speeds—a crucial feature for locales like Maldo Island, where typical wind speeds range from 3 to 6 m/s, considered low to moderate. With an energy efficiency exceeding 90%, generating an annual power output of 2266.3 kWh, and achieving a facility utilization rate of 10.34%, the results underscore the potential of the ECWH system as an efficient and sustainable solution for heating in areas with similar wind conditions.

Оценки положения Северного магнитного полюса в 2021 году

Based on measurements of magnetic declinations with standard shipboard instruments in three marine expeditions in the Russian Arctic, estimates of the Earth`s North Magnetic Pole position in 2021 were obtained. It is located in the Russian sector of the Arctic. Experiments on determining the North Magnetic Pole in 2021 were carried out on board the research vessels “Professor Molchanov” and the scientific expedition one “Mikhail Somov” supported by the hydrographic ship of “Horizon”. The calculations used a comparison of measurements along the quasi-closed route with magnetic declination data using the International Geomagnetic Analytical Field IGRF13 (International Geomagnetic Reference Field) model with the choice of the minimum discrepancy, a simple inverse matching problem for smooth functions was solved. The results obtained confirm the possibility of regular operational assessment of the Earth`s magnetic poles position. The technology of assessing the magnetic deviation of ships is considered

Detecting life by behavior, the overlooked sensitivity of behavioral assays

Detecting life has driven research and exploration for centuries, but recent attempts to compile and generate a framework that summarizes life features, aimed to develop strategies for life detection missions beyond planet Earth, have disregarded a key life feature: behavior. Yet, some behaviors such as biomineralization or motility have occasionally been proposed as biosignatures to detect life. Here, we capitalize on a specific taxis’ motility behavior, magnetotaxis, to experimentally provide insights in support of behavior as an unambiguous, sensitive biosignature, and magnetic forces as a prescreening option. Using a magnetotactic bacterial species, Magnetospirillum magneticum, we conducted a lab sensitivity experiment comparing PCR with the hanging drop behavioral assay, using a dilution series. The hanging drop behavioral assay visually shows the motility of MTB toward magnetic poles. Our findings reveal that the behavioral assay exhibits higher sensitivity in the detection of M. magneticum when compared to the established PCR protocol. While both methods present similar detection sensitivities at high concentrations, at ≥ 10–7 fold dilutions, the behavioral method proved more sensitive. The behavioral method can detect bacteria even when samples are diluted at 10–9. Comparable results were obtained with environmental samples from the Hula Valley. We propose behavioral cues as valuable biosignatures in the ongoing efforts of life detection in unexplored aquatic habitats on Earth and to stimulate and support discussions about how to detect extant life beyond Earth. Generic and robust behavioral assays can represent a methodological revolution.

Laminar flow and convective heat transfer of ferrofluid in a tube under oscillating magnetic fields: Effect of magnetic phase shift

In this study, laminar flow and forced convective heat transfer of water-based ferrofluids flowing through a uniformly heated pipe are experimentally investigated under the presence of phase-shifted oscillating magnetic fields. To investigate the effect of phase shift on heat transfer, electromagnets are positioned along the tube, and oscillating magnetic fields are applied with various phase shift angles between opposing magnetic poles. Experiments are conducted for different Reynolds numbers (400 to 1000), magnetic field frequencies (0 Hz, 1 Hz, and 5 Hz), phase shift angles (0°, 90°, and 180°), and nanoparticle volume fractions (0.5 % and 1 %). For each parameter set, local and average Nusselt numbers, as well as pressure drop values, are determined, and the effect of applied magnetic fields on the heat transfer rate is extensively discussed. Results showed that, applying an external magnetic field resulted in significant enhancements in the forced convective heat transfer of ferrofluid. Under an oscillating magnetic field with 0° phase shift, maximum of 40 % and 20.6 % enhancements were observed in local and average Nusselt numbers respectively under the investigated parameters. Furthermore, applying oscillating magnetic fields with a phase shift between opposing poles caused significant fluctuations in the fluid, led to remarkable improvements in convective heat transfer rates. For 90° and 180° phase shifts, enhancements in local and average Nusselt numbers were observed to increase up to 73 % and 36 %, respectively.

Torque Performance Analysis of Asymmetric Magnetic Pole Permanent Magnet Synchronous Motor for New Energy Vehicles

In view of the problem of large torque ripple and poor output performance of permanent magnet synchronous motor, a new topology of asymmetric magnetic pole permanent magnet synchronous motor is proposed, and the torque ripple of this motor structure and the suppression method are analyzed. First, the equivalent magnetic circuit method and Lorentz force law are used to derive the analytical formula of torque ripple of the motor. Then, based on the analytical formula, the parameters of permanent magnet of the asymmetric magnetic pole permanent magnet synchronous motor are optimized and verified by finite element software simulation; on this basis, the method of rotor eccentricity is used to further weaken the torque ripple of the motor, and the optimal eccentricity distance is analyzed. The research shows that when the parameters of the magnetic pole of the asymmetric magnetic pole permanent magnet synchronous motor is appropriate, the harmonic content of the air gap magnetic density of the optimized motor is greatly reduced, and the motor has good output characteristics, and the torque ripple is reduced to 5.4%. Finally, the prototype is trial‐manufactured and tested. The results show that after optimization, the cogging torque of the motor is reduced, the torque output performance is improved, and the overall motor performance is improved. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.

A hybrid harvester using a magnetically coupled pendulum structure for limb movement

ABSTRACT Energy harvesting and conversion devices can provide power solutions for wearable devices. In this paper, a piezo-electromagnetic hybrid energy harvester (PEMHEH) using a magnetically-coupled pendulum structure for low-frequency limb movement is proposed. PEMHEH consists of a piezoelectric generator (PEG) unit including a main piezoelectric transducer, an auxiliary piezoelectric transducer (APT), and an electromagnetic generator (EMG) unit. It can reduce the starting frequency and increase the output performance by adopting a slidable mass block, the APT, and the rational magnetic pole arrangement. Its theoretical model is established, and magnetic simulation and experimental tests are carried out. The results show it can be started at 0.4 Hz excitation, and the output performance is maximized at 2 Hz. The maximum voltages of the piezoelectric generator and electromagnetic generator units are 5.29 V and 457 mV, and the maximum power is 286.16 μW (30 kΩ) and 11.25 μW (2 kΩ). The PEMHEH can light up LED boards at a 1 Hz excitation frequency. It has the potential to power wearable devices.

Study on the Impact of Pole Spacing on Magnetic Flux Leakage Detection under Oversaturated Magnetization.

Magnetic flux leakage (MFL) inspection employs leakage magnetic fields to effectively detect and locate pipeline defects. The spacing between magnetic poles significantly affects the leakage magnetic field strength. While most detectors typically opt for moderate pole spacing for routine detection, this study investigates the propagation characteristics of MFL signals at small pole spacings (under specimen oversaturated magnetization) and their impact on MFL detection. Through finite element simulation and experiments, it reveals a new signal phenomenon in the radial MFL signal By at small pole spacings, the double peak-valley (DPV) phenomenon, characterized by outer and inner peaks and valleys. Theoretical analysis based on the simulation results elucidates the mechanisms for this DPV phenomenon. Based on this, the impact of defect size, pipe wall thickness, and magnetic pole and rigid brush height on MFL signals under small magnetic pole spacings is examined. It is demonstrated that, under a smaller magnetic pole spacing, a potent background magnetic field manifests in the air above the defect. This DPV phenomenon is generated by the magnetic diffusion and compression interactions between the background and defect leakage magnetic fields. Notably, the intensity of the background magnetic field can be mitigated by reducing the height of the rigid brush. In contrast, the pipe wall thickness and magnetic pole height exhibit a negligible influence on the DPV phenomenon. The emergence of the DPV precipitates a reduction in the peak-to-valley difference within the MFL signal, constricting the depth range of detectable defects. However, the presence of DPV increases the identification of defects with smaller opening sizes. These findings reveal the characterization of the MFL signal under small pole spacing, offering a preliminary study on identifying specific defects using unconventional signals. This study provides valuable guidance for MFL detection.

Metal accretion scars may be common on magnetic, polluted white dwarfs

More than 30% of white dwarfs exhibit atmospheric metals, which are understood to be from recent or ongoing accretion of circumstellar debris. In cool white dwarfs, surface motions should rapidly homogenise photospheric abundances, and the accreted heavy elements should diffuse inward on a timescale much longer than that for surface mixing. The recent discovery of a metal scar on WD 0816–310 implies its B ≈ 140 kG magnetic field has impeded surface mixing of metals near the visible magnetic pole. Here, we report the discovery of a second magnetic, metal-polluted white dwarf, WD 2138–332, which exhibits periodic variability in longitudinal field, metal line strength, and broadband photometry. All three variable quantities have the same period, and show remarkable correlations: the published light curves have a brightness minimum exactly when the longitudinal field and line strength have a maximum, and a maximum when the longitudinal field and line strength have a minimum. The simplest interpretation of the line strength variability is that there is an enhanced metal concentration around one pole of the magnetic field; however, the variable line-blanketing cannot account for the observed multi-band light curves. More theoretical work is required to understand the efficiency of horizontal mixing of the accreted metal atoms, and the origin of photometric variability. Because both magnetic, metal-polluted white dwarfs that have been monitored to date show that metal line strengths vary in phase with the longitudinal field, we suggest that metal scars around magnetic poles may be a common feature of metal-polluted white dwarfs.

Polar magneto-optical Kerr effect spectroscopy with a microscope arrangement for studies on 2D materials.

We describe a setup for magneto-optical Kerr effect (MOKE) spectroscopy suitable for Kerr rotation (ϕ) and ellipticity (η) measurement on microscopic samples, such as flakes of two-dimensional materials. A spatial resolution of ∼25μm, limited by the demagnified monochromator exit slit image, was achieved. The use of mirrors allows for measurement in polar MOKE geometry with a conventional electro-magnet, without requiring holes in the magnet pole pieces. The microscope-like optics also has a 90° twisted periscope arrangement of two mirrors that helps transport light without change in its circular polarization state. A Jones matrix analysis of the setup brings out the influence of the beam-splitter on the measured signals. Its correction requires the ellipsometry parameters of the beam-splitter in transmission mode, which were measured separately. The working of the setup is tested by measuring the ϕ and η spectra of 2H-WS2 flakes at low temperature, verifying them using Kramers-Kronig analysis and extracting the Landé g-factor of the ground state exciton from them.

Dynamic Analysis and PD Control in a 12-Pole Active Magnetic Bearing System

This paper conducts an in-depth study on the dynamic stability and complex vibration behavior of a 12-pole active magnetic bearing (AMB) system considering gravitational effects under a PD controller. Firstly, based on electromagnetic theory and Newton’s second law, a two-degree-of-freedom control equation of the system, including PD control terms and gravitational effects, is constructed. This equation involves not only parametric excitation, quadratic nonlinearity, and cubic nonlinearity but also a more pronounced coupling effect between the magnetic poles due to the presence of gravity. Secondly, using the multi-scale method, a four-dimensional averaged equation of the system in Cartesian and polar coordinates is derived. Finally, through numerical analysis, the system’s amplitude–frequency response, motion trajectory, the relationship between energy and amplitude, and global dynamic behaviors such as bifurcation and chaos are discussed in detail. The results show that the PD controller significantly affects the system’s spring hardening/softening characteristics, excitation, amplitude, energy, and stability. Specifically, increasing the proportional gain can quickly suppress the rotor’s motion, but it also increases the system’s instability. Adjusting the differential gain can transition the system from a chaotic state to a stable periodic motion.

The Effect of Static Magnetic Fields of Different Strengths and Polarities on Cytokine Production by Human Lymphocytes In Vitro.

In contrast to electromagnetic fields, static magnetic fields (SMFs) have not been extensively studied in terms of their potential health consequences. Although upward- and downward-oriented magnetic poles may cause various biological effects, only the pole with the upward orientation has been mainly investigated. Considering that the interaction of antigen-presenting cells (APCs) and T lymphocytes is crucial to trigger an immune response, we assessed the effect of long-term exposure of human T lymphocytes and dendritic cells (DCs) to moderate strength SMFs of different orientations focusing on the cytokine profile of activated T cells. Cultures of allogenic T lymphocytes and DCs (immature and matured by TLR3 and TLR7 agonists) were continuously exposed to four SMFs. The intensity of the applied field was 1 militesla (mT) or 56 mT of the upward- and downward-oriented pole of the SMF. Cell culture supernatants were assayed for IFN-γ, IL-4, IL-17, TNF-α, TNF-β, IL-1 β, IL-6, IL-8, and IL-10 by ELISA or flow cytometry. The upward-oriented 56 mT SMF significantly increased the release of IFN-γ and TNF-β (both p < 0.05) in the cell culture supernatants of T cells and immature DCs. In contrast, the same cultures exposed to the upward-oriented 1 mT SMF showed significantly elevated levels of IL-17 (p < 0.05). The levels of IL-4, TNF-α, IL-1 β, IL-6, IL-8, and IL-10 were not affected by the upward-oriented SMF. The downward-oriented 56 mT SMF increased TNF-α release when T cells were stimulated with mature DCs. The production of other cytokines was unchanged by the downward-oriented SMF. These findings demonstrate for the first time different in vitro biological effects of upward- and downward-oriented static magnetic fields on the cytokine production of T cells activated by DCs, helping to better understand SMF effects on the immune system and suggesting that the selective SMF effect on the immune response could have potential therapeutic effects in different immune-mediated disorders.

A study of rare-earth magnet profiles for torque ripple improvement of axial flux permanent magnet machine

Purpose The purpose of this study is to reduce the cogging torque in axial flux permanent magnet (AFPM) machine using optimal magnet shape. Design/methodology/approach This study analyzes different magnet shapes for AFPM machine performance enhancement. Three-dimensional (3D) finite element analysis is performed to see the effects of pole shaping on the cogging torque of the AFPM machine. Findings The magnetic pole shape has a significant effect on cogging torque and overall efficiency. The conventional model has the highest torque whereas the conventional skewing affected cogging torque positively and significantly reduced the cogging torque. The combination of skewing the pole along with face curving is more effective and decreases the cogging torque from 3.88 Nm to 1.5 Nm. Originality/value Rare-earth magnets are the most expensive and important part of AFPM machines. Shape and volume optimization of rare-earth magnets is crucial for the performance of AFPM machines. The research aims to analyze the different permanent magnet designs for performance improvement of the AFPM machine. Conventional flat top trapezoidal, curved-top and skewed-magnet shapes are analyzed and the performance of the AFPM machine is compared with different magnet shapes. Curved-top shape and skewed magnet significantly reduce the cogging torque. Furthermore, a combination of curved-top shape and skew magnet shape is proposed to reduce the cogging torque further and improve the AFPM machine’s overall performance. Newly proposed magnet profile gives skewed curve magnet shapes which reduce the cogging torque further. 3D finite element analysis has been used to analyze the single-sided AFPM with all four different magnet shapes. The research focuses on single-sided AFPM machines, but the results are also valid for double-sided AFPM machines and can be extended to other topologies of AFPM machines.

An adjustable acoustic metamaterial cell using a magnetic membrane for tunable resonance

Acoustic metamaterials are growing in popularity for sound applications including noise control. Despite this, there remain significant challenges associated with the fabrication of these materials for the sub-100 Hz regime, because acoustic metamaterials for such frequencies typically require sub-mm scale features to control sound waves. Advances in additive manufacturing technologies have provided practical methods for rapid fabrication of acoustic metamaterials. However, there is a relatively high sensitivity of their resonant characteristics to sub-mm deviations in geometry, pushing the limits of additive manufacturing. One way of overcoming this is via active control of device resonance. Here, an acoustic metamaterial cell with adjustable resonance is demonstrated for the sub-100 Hz regime. A functionally superparamagnetic membrane—devised to facilitate the fabrication process by eliminating magnetic poling requirements—is engineered using stereolithography, and its mechanical and acoustic properties are experimentally measured using laser Doppler vibrometry and electret microphone testing, with a mathematical model developed to predict the cell response. It is demonstrated that an adjustable magnetic acoustic metamaterial can be fabricated at ultra-subwavelength dimensions (≤λ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\le \\lambda$$\\end{document}/77.5), exhibiting adjustable resonance from 88.73 to 86.63 Hz. It is anticipated that this research will drive new innovations in adjustable metamaterials, including wider frequency ranges.

Waiting Time Distribution of Giant Pulses from the Crab Pulsar Modeled with a Non-stationary Poisson Process

We study the waiting time distribution of giant pulses from the Crab pulsar observed with the Nanshan 26-m radio telescope at a center frequency of 1556 MHz with 512 MHz bandwidth. The observations were performed over a duration of 12.6 hours with 32 μs sampling interval. Our analysis has led to the detection of 2097 giant pulses above a threshold of 10 σ, with flux density > 100 Jy. The occurrence rate of giant pulses is characterized by a highly intermittent giant pulse productivity in short clusters with high rates, separated by relatively long quiescent intervals with low occurrence rates, especially for the giant pulses associated with the interpulse emission. The distribution of waiting times between two subsequent giant pulses displays a power-law tail that can be modeled with a non-stationary Poisson process, which indicates that giant pulses are independent and random events. Distinct waiting time distributions between giant pulses in the main pulse and interpulse phases are presented, which implies that the giant pulse emission mechanisms maybe different in the opposite magnetic poles. The ramification for our understanding of the radio emission mechanisms is discussed.

EXPERIMENTAL INVESTIGATION OF NEWLY DEVELOPED ELECTROLYTIC MAGNETIC ABRASIVE FINISHING SETUP WITH MULTIPLE POLE SYSTEM FOR FINISHING OF ALUMIUM WORKPIECE

The procedure of combining abrasion machining with chemical machining is the most demanding and crucial method of machining, because it guarantees higher levels of quality from the part. Combined procedure for machining are typically employed as the last step in the machining process, and their significance grows progressively crucial while a nano finished surface of the work piece material is necessary. The subject of nano surface finishing of materials via chemical machining and abrasion has advanced recently. Electrolytic magnetic abrasive finishing (EMAF) is a procedure that combines chemical and magnetic energy to achieve a desire finish. During the EMAF process, The work piece fits in the middle among two magnetic poles. A mixture of abrasives and ferromagnetic particles fills the gap between each pole and the workpiece. The electrode is positioned at a certain distance from the workpiece, and both are linked to a direct current (DC) power source. An electrolytic solution is circulated between the gap using a pump. The method offer a wide range of industrial applications because to its low specific energy consumption and enhanced surface finishing. This study presents the creation of a novel EMAF with multiple pole system. It further looks into the impact of different process attributes include machining time, rotational speed, size of the abrasive particles, electrolytic concentration and weight of the abrasive particles on the improved performance of material removal rate (MRR) and surface finishing (PISF).

Cogging Torque Reduction of Brushless DC Motor: Investigating the Efficacy of Ra-dial Pole Shaping Technique with Novel Bump-Shaped Rotor Pole

With the rising demand for high-performance motors in electrical vehicle applications, permanent magnet brushless DC motors are a promising solution due to their various attractive features. However, it has a significant drawback of high cogging torque, which deteriorates the overall motor performance. This negative impact is dominating in electric vehicles for low-speed applications. It is desirable to reduce the cogging torque to improve the performance of the radial flux brushless DC motor. The prime focus of this research is reducing cogging torque through the radial pole shaping technique with a bump-shaped rotor pole surface. This work also investigates the impact of the proposed approach on torque ripple and motor performance while cutting down the requirement for rare earth material. This paper uses two ratings: 1000 W, 510 rpm, and 250 W, 150 rpm motors. Two reference motors of proposed ratings were designed using radial-shaped permanent magnet poles. Finite element software is used for the simulation and modeling of the motors. A novel bump-shaped permanent magnet pole shape is introduced, and in-depth investigations have been carried out to evaluate the impact of the proposed pole shape on cogging torque. The validity of the analysis results is further substantiated by comparing the improved and reference model results. The comparison investigation indicates that the motor equipped with the proposed pole shape performs better than the reference motor.

Study on the Influences of an Outer-Coreless-Rotor Permanent Magnet Synchronous Machine Using Halbach Magnet Array

In order to evaluate the influences of the topology design of a Halbach Magnet Array (HA) on the performance of a motor, a PMSM with an outer coreless rotor using a Halbach Magnet Array (HAORPMSM) is proposed in this article. The design parameters of the HA could be separated into dividing methods per pole, magnet thickness, and initial magnetization direction angle. The phase Back-EMF under constant mechanical speed is chosen as the index to measure the performance of the motor. To start with, different dividing methods of the HA are evaluated. After that, the influence of thickness considering the utilization of the magnet is studied. Lastly, the relationship between initial magnetization direction and motor manufacturing is represented. The results show that the HA design meets the optimized performance considering the balance of the amount of magnet usage and manufacturing when using specific HA parameters.

A trend of "geomagnetic jerks" in the inhibition of the earth's south magnetic pole?

The possibility of a reversal in the displacement of the Earth's South Magnetic Pole (SMP), the speed of which has decreased threefold over the past 60 years, is being discussed, which does not contradict the theory of “geomagnetic jerks.” The results of the experiment on measurements of magnetic declination on 6-9.04.2020 in the Southern Ocean are presented. Remote measurements are caused by the fact that during the day the SMP moves along a quasi-closed perimeter with semi-axis sizes up to 50 km. The discrepancies between the magnetic declination measurements and the model isogons of the International Geomagnetic Reference Field (IGRF13) model allow us to estimate the daily average position of the SMP. An example with the estimation of magnetic deviation of ship magnetic declination observations affecting the SMP position determinations is analyzed.