Browse Topic: Magnetic materials

Items (1,916)
ABSTRACT The demand for increased export power generation and ground vehicle electrification are escalating trends due to the warfighter’s expanding mission requirements. Today’s low-voltage alternators used in some fielded ground vehicle’s power systems supply up to 650ADC, or 18kW. Future demand for vehicle export power generation is expected to reach and exceed 100kW. A majority of electric machines capable of meeting this level of power generation rely on rare-earth elements such as Neodymium (Nd), Samarium (Sm), Dysprosium (Dy) and Terbium (Tb). Due to diminished reserves in the United States, availability abroad and price volatility, continued use of rare-earth permanent magnet materials may not be viable. The expanding demand for vehicle power is on a trajectory which surpasses the U.S. ability to reliably harvest or procure rare-earth magnet materials. As such, electric machine topologies that utilize zero rare-earth magnet materials are being considered for ISG (integrated
Riley, KatherineConway, ShanShanLee, Seong T.Jung, Yong-BaeZanardelli, Wesley G.Wright, Ronnie L.
Improvements in trace biological molecule detection can have significant impact on healthcare, food safety, and environmental safety industries. Detection of trace biological molecules can be critical to the diagnosis of early onset of diseases or infections. Researchers at NASA Ames Research Center developed an electrochemical, bead-based biological sensor based on Enzyme-Linked Immunosorbent Assay (ELISA) combining a magnetic concentration of signaling molecules and electrochemical amplification using wafer-scale fabrication of microelectrode arrays
Magnetic cooling technology, grounded in the magnetocaloric effect, is a significant area of study given its immense potential to address escalating energy demands and environmental issues posed by current technologies. Investigations into magnetic cooling systems encompass engineering endeavours and materials research. Magnetic refrigeration at room temperature represents a cutting-edge, high-efficiency, and eco-friendly technology. Despite its current developmental stage, it exhibits immense potential for practical applications and appears to be a viable alternative to conventional vapor compression methods. This review primarily focuses on the applications and materials research aspect of these studies, offering insights into the latest advancements in the field
Meduri, SunilChalla, KrishnaPonangi, Babu Rao
Manufacturing flaws and microstructure irregularities pose challenges for the widespread adoption of metal additive manufacturing (MAM) in the US Army. These issues stem from the influence of melt-pool dynamics on the properties of 3D-printed metal parts, which are highly dependent on multiple process parameters. This paper investigates the potential of using electromagnetic fields (EM) to control the melt-pool dynamics in MAM, aiming to eliminate flaws and irregularities. A novel technique is proposed, involving a coil and strategically positioned permanent magnets to actively churn the melt pool. Initial validation of this approach was conducted using COMSOL Multiphysics® through simulation modeling, with ongoing efforts for experimental verification. The findings indicate promising opportunities for enhancing the consistency of 3D printed parts
Karpenko, OleksiiUdpa, SatishUdpa, LalitaHaq, Mahmood
A potentially effective means for ground system radar cross section reduction (RCSR) involves a checkerboard-arranged applique (ACA) composed of artificial magnetic conductor (AMC) metasurfaces which can result in phase modification – and thus destructive interference – of the reflected radar energy. This effort focused on the development of such a concept through the following main tasks: (1) the development of performance goals; (2) the selection of the AMC topology pattern; (3) the development of various performance models based upon transmission line theory and antenna planar array theory, and the use of various computational electromagnetics (CEM) solvers; (4) model validation; (5) the optimization of the AMC pattern through a design of experiment (DOE) approach; and (6) the development of a genetic programming framework for more rigorous ACA optimization
Tison, NathanD’Archangel, Jeffrey
A Columbia Engineering team has published a paper in the journal Joule that details how nuclear magnetic resonance spectroscopy techniques can be leveraged to design the anode surface in lithium metal batteries. The researchers also present new data and interpretations for how this method can be used to gain unique insight into the structure of these surfaces
Noise, vibration and harshness (NVH) is one of the most important performance evaluation aspects of electric motors. Among the different causes of the NVH issues of electrical drives, the spatial and temporal harmonics of the electrical drive system are of great importance. To reduce the tonal noise of the electric motors induced by these harmonics, harmonic injection methods are applied in many applications. However, a lot of existing researches focus more either on improving the optimization process of the harmonic injection parameter settings, or on the controller design of the harmonic injection process, while the structural dynamic characteristics of the motor are seldom considered. A lot of literature shows that the harmonic injection strategies can more effectively influence the mode 0 (M0) radial forces than the higher spatial orders, so it is more efficient to apply such methods at the frequencies/orders where the effect of mode 0 forces are dominant with respect to the
Fu, TongfangXu, ZhipengGünther, MarcoPischinger, StefanBöld, Simon
MIT researchers have developed a battery-free, self-powered sensor that can harvest energy from its environment. Because it requires no battery that must be recharged or replaced, and because it requires no special wiring, such a sensor could be embedded in a hard-to-reach place, like inside the inner workings of a ship’s engine. There, it could automatically gather data on the machine’s power consumption and operations for long periods of time
A team of researchers at the University of Missouri have made a significant breakthrough in their ongoing development of an on-skin wearable bioelectronic device. Zheng Yan’s lab, which specializes in soft bioelectronics, recently added an important component to the team’s existing ultrasoft, breathable and stretchable material. The key feature: wireless charging — without batteries — through a magnetic connection
Soft magnetic cores of electric motors and generators are normally manufactured by stamping individual circular laminates from non-oriented electrical steel (NOES) sheets and stacking them layer by layer to reach the required height. The traditional lamination method can only achieve the average performance of the NOES since the magnetization is in all the directions of the sheet plane. Although NOES is ideal to have isotropic magnetic properties in all the directions of the sheet plane, commercially available electrical steel sheets always show apparent anisotropy in the rotating magnetization directions lying in the sheet plane. The anisotropy in magnetic properties not only causes fluctuations in the rotating magnetic field, but also leads to oscillations in electromagnetic torque, and thus needs to be minimized. In this paper, a novel electrical steel lamination technique is developed, which takes the advantage of the inherent magnetic anisotropy of electrical steel sheets to
He, YouliangSebesta, DamirPodlesny, Maciej
In electric vehicle applications, the majority of the traction motors can be categorized as Permanent Magnet (PM) motors due to their outstanding performance. As indicated in the name, there are strong permanent magnets used inside the rotor of the motor, which interacts with the stator and causes strong magnetic pulling force during the assembly process. How to estimate this magnetic pulling force can be critical for manufacturing safety and efficiency. In this paper, a full 3D magnetostatic model has been proposed to calculate the baseline force using a dummy non-slotted cylinder stator and a simplified rotor for less meshing elements. Then, the full 360 deg model is simplified to a half-pole model based on motor symmetry to save the simulation time from 2 days to 2 hours. A rotor position sweep was conducted to find the maximum pulling force position. The result shows that the max pulling force happens when the rotor is 1% overlapping with the stator core. The impact of asymmetric
Gong, ChengChang, LeHe, SongZhang, PengMuir, Michael
This paper analyzes the leakage magnetic field generated by the Bi-Directional wireless charging system of Electric Vehicle(EV) and confirms the effect of the shielding coil in the Bi-Directional wireless charging system. In particular, in EV using the Inductive Power Transfer(IPT) method, the effective shielding coil position is proposed by analyzing the contribution of the leakage magnetic field of the Ground Assembly(GA) coil and the Vehicle Assembly(VA) coil according to the power transfer direction. Simulations were conducted using the WPT3/Z2 model of the standard SAE J2954, and it was confirmed that the GA coil contributed more to the leakage magnetic field due to the relatively large size compared to the VA coil regardless of power transfer direction. The same tendency was confirmed not only in alignment condition but also in misalignment condition, and it was also confirmed that the same tendency appeared in the situation where a larger current flows in the VA coil by
Son, SeokhyeonHan, SeunghyunJun, ChanghanShin, DongilWoo, SeminPark, MyungjoonPark, JunhoShin, JuhyunKwon, Daehyun
Wound rotor synchronous machines (WRSM) without rare-earth magnets are becoming more popular for traction applications, but their potential in drive performance has not yet been fully explored. This paper presents a Pulse Width Modulation (PWM) scheme optimization procedure to minimize motor and inverter losses. It leverages different PWM schemes with different PWM switching strategies and switching frequencies. First, a generic PWM-induced motor loss calculation tool developed by BorgWarner is introduced. This tool iteratively calculates motor losses with PWM inputs across the entire operating map, significantly improving motor loss prediction accuracy. The inverter losses are then calculated analytically using motor and wide-bandgap (WBG) switching device characteristics. By quantifying these various scenarios, the optimal PWM scheme for achieving the best system efficiency across the entire operating map is obtained. The PWM-induced motor loss characteristics, the system loss
Ma, CongTyckowski, Joseph
Focused on the permanent magnet synchronous motor (PMSM) used in electric, this paper proposes an online insulation testing method based on voltage injection under high-temperature and high-humidity conditions. The effect of constant humidity and temperature on the insulation performance has been also studied. Firstly, the high-voltage insulation structure and principle of PMSM are analyzed, while an electrical insulation testing method considered constant humidity and temperature is proposed. Finally, a temperature and humidity experimental cycling test is carried out on a certain prototype PMSM, taking heat conduction and radiation models, water vapor, and partial discharge into account. The results show that the electrical insulation performance of the motor under constant humidity and temperature operation environment exhibits a decreasing trend. This study can provide theoretical and practical references for the reliable durability design of PMSM
Zhang, WeiQiu, ZizhenKong, ZhiguoHuang, XinWang, Fang
This paper presents a numerical methodology to generate lookup tables that provide d- and q-axis stator current references for the control of electric motors. The main novelty with respect to other literature references is the introduction of the iron power losses in the equivalent-circuit electric motor model implemented in the optimization routine. The lookup tables generation algorithm discretizes the motor operating domain and, given proper constraints on maximum stator current and magnetic flux, solves a numerical optimization problem for each possible operating point to determine the combination of d- and q- axis stator currents that minimizes the imposed objective function while generating the desired torque. To demonstrate the versatility of the proposed approach, two different variants of this numerical interpretation of the motor control problem are proposed: Maximum Torque Per Ampere and Minimum Electromagnetic Power Loss. A practical example of calculation of the lookup
Grano, EliaLazek, TomasCarello, Massimiliana
The powertrain system plays a crucial role in electric vehicles, exerting significant impact on both the dynamic and economic performances. A breakthrough has been observed by using the dual-motor powertrain system, which outperformed its single-motor counterparts. This study reports a dual-motor powertrain with magnetorheological technology. The powertrain consists of two motors, two magnetorheological brakes and a planetary gear set. Via regulating the brakes, the power transmission flow can be controlled to realise different torque ratios and velocities. The synergetic control of motors and brakes is capable of achieving smooth gear shifting without interruption. This paper details the design of the powertrain system: the structural configuration of the magnetorheological brakes is highlighted, the magnetic field distribution of the brakes under different currents is simulated by COMSOL Multiphysics, and the torque capacities of the brake are also calculated. Future work will focus
Deng, LeiZhao, JinNing, DonghongWong, PakZhao, JingLi, WeihuaDu, Haiping
The modern luxurious electric vehicle (EV) demands high torque and high-speed requirements with increased range. Fulfilling these requirements gives rise to the need for increased efficiency and power density of the motors in the Electric Drive Unit (EDU). Internal Permanent Magnet (IPM) motor is one of the best suited options in such scenarios because of its primary advantages of higher efficiency and precise control over torque and speed. In the IPM motor, permanent magnets are mounted within the rotor body to produce a resultant rotating magnetic field with the 3-phase AC current supply in the stator. IPM configuration provides structural integrity and high dynamic performance as the magnets are inserted within the rotor body. Adhesive glue is used to install the magnets within the laminated stack of rotor. High rotational speed of rotor introduces centrifugal loading on the magnets which can result in multiple failure modes such as the debonding of the magnet, and high radial
Karmakar, NilankanP, PraveenGoel, Ashish
Researchers at Universidad Carlos III de Madrid (UC3M) have created software and hardware for a 4D printer with applications in the biomedical field. In addition to 3D printing, this machine allows for controlling extra functions: programming the material’s response so that shape-changing occurs under external magnetic field, or changes in its electric properties develops under mechanical deformation
Sustainable manufacturing, a term that has been used in the recent past on numerous occasions. A primary reason for it being in limelight, is that it does not cause any damage to the environment and also to the personal involved. Additionally, another important parameter of concern is the energy consumed during the machining process. One major reason for higher energy consumption is because of the presence of tool vibration. There have been several attempts made to reduce vibration and though they have been proved to be effective, they could be not classified under sustainable manufacturing. When used as a semi-active damper in metal cutting, magnetorheological fluid (MRF) has proven to be successful in vibration suppression. MRF is an intelligent non-Newtonian fluid that can change its viscosity instantly when a magnetic field is applied to it. They've utilised it as a damper in a number of areas because of this quality and its toughness. One significant drawback is the settling of
Ajay Vasanth, X.Sam Paul, P.Lawrance, G.Rajkumar, V.Senthilkumar, K.
This specification covers fluorescent magnetic particles in the form of a mixed, ready-to-use suspension in an odorless inspection oil vehicle
AMS K Non Destructive Methods and Processes Committee
This SAE Aerospace Standard (AS) covers water conditioning agents used to facilitate aqueous wet-method magnetic particle inspection
AMS K Non Destructive Methods and Processes Committee
This paper introduces a comprehensive approach aimed at maximizing the efficiency of Permanent Magnet Synchronous Motors by employing various slot-pole combinations. The study focuses on Fractional Slot Concentrated Winding Interior Permanent Magnet Synchronous Motors and conducts a quantitative comparison involving two distinct slot-pole configurations. These configurations are evaluated based on their torque capability, efficiency, and cogging torque characteristics. The research delves into the selection criteria for IPMSMs, leveraging the efficiency mapping analysis facilitated by genetic algorithms and optimization tools. Specifically, the investigation centers around two FSCW IPMSMs with optimized motor dimensions: one with an 8P-12S configuration and the other with a 10P-15S configuration. These motors are meticulously scrutinized and juxtaposed in terms of their electromagnetic performance at rated and peak operating points. The assessment takes into account factors like torque
Gurudevan, VinothiniKhanchoul, MohamedElumalai, Ilakya
The automotive industry has recently started implementing magnetic gears, in different types, as an alternative design for transmission systems. One such design being the Magnetic planetary gear permanent magnet (MPG-PM) machine. The current methodology and the relevant formulae help to design the magnetic planetary gear system, which does not have design considerations for permanent magnet machines and the influence of magnetic fields. The influence of design characteristics of PM machine, Magnetic field and its material plays a vital role in designing the MPG-PM for electric vehicle applications. A method of optimizing the Gear topology design parameters of a magnetic planetary gear permanent magnet machine (MPG-PM machine) is proposed. The Analytical calculations regarding the design parameters are proposed in relation to power, gear ratios, and other design constraints like packaging parameters i.e., outer diameter, the overall length of the machine. The analytical calculation
Ramakrishnan, Gowtham Raj
Corrosion affects all industrial sectors where metals or metal alloys are used in their structures. In the automotive industry, the continuous search for lightweight parts has increased the demand for effective corrosion protection, in order to improve vehicle performance without compromising durability and safety. In this scenario, coatings are essential elements to preserve and protect vehicle parts from various environmental aggressions. Automotive coatings can be classified into primers, topcoats, clearcoats, and specialty coatings. Primers provide corrosion resistance and promote adhesion between the substrate and topcoat. Topcoats provide color, gloss, and durability to the coating system, while clearcoats enhance the appearance and durability of the finish. Specialty coatings provide additional properties, such as scratch resistance, chemical resistance, and UV protection. In addition to these categories, there are the smart coatings, defined as those capable of modifying their
Vanzetto, Andrielen BrazNeves, GuilhermeAlves, Tamires PereiraMoura, João Henriquede Bortoli, Bruna FariasSantana, Leande Oliveira Polkowski, Rodrigo Denizarte
This specification covers fluorescent magnetic particles in the form of a dry powder
AMS K Non Destructive Methods and Processes Committee
Conventional magnetorheological dampers (CMRD) generate damping force through the flow of magnetorheological fluid in a narrow passage. However, due to the fixed geometry of the passage, the damping force is linearly proportional to the velocity. This structural limitation results in significant damping forces at high speeds, severely impacting the energy dissipation efficiency of the damper. This flaw poses a substantial threat to both occupants and mechanical structures. In response to this limitation, this research endeavors to engineer a novel impact-resistant MR damper (NMRD) by augmenting the traditional MR damper’s architecture with an innovative internal channel furnished with an embedded circular permanent magnet. During instances of high-velocity impacts, this specialized channel selectively opens to attenuate impact forces. This augmentation serves to significantly heighten the soft landing impact resistance of flying cars while concurrently enhancing passenger comfort. A
Jiang, LanGong, NingHu, TaoPan, LiYanSun, Shuaishuai
A research team has developed diamond quantum sensors that can be used to improve resolution in magnetic imaging. In order to test the method, the scientists placed a microchip with microscopic water-filled channels on the diamond quantum sensor. This allowed the researchers to simulate microstructures of a cell. They were able to successfully analyze the diffusion of water molecules within the microstructure
The operation of two-wheelers, or bikes, presents risks due to factors such as excessive speed, severe acceleration, and over-tilting, which may compromise the stability of the vehicle. This study proposes a solution to enhance ride safety and turn ability by integrating automatic speed reducers and a motion stabilizer, modelled using CATIA and designed from PVC material. The stabilizer is situated between the fork arms, holding a magnet, which initiates automatic braking when the magnet approaches the rim during a turn. We conducted three modes of testing, including no load and no angle, under magnetic load at zero angles, and under magnetic load at various angles in both lateral directions. Frequency data corresponding to the calculated speed was recorded using a spectrum analyzer, and we performed counterbalancing weight calculations to ensure stability. The results revealed a reduction in speed due to magnetic action. The objective was to design a setup that can be used for a safe
S, RagulRadhika Venugopal Jawahar, VenkatesanVenugopalan, RudraSankarasubramanian, Hariharan
MQ1 magnets are particularly suitable for demanding applications such as automotive accessories and home appliances. Isotropic bonded NdFeB magnets, colloquially termed MQ1, offer several unique advantages in various motor applications. These include being free of heavy rare-earth materials, providing high yield in near-net-shape magnet production, allowing tailored magnetization profiles for optimal magnet performance due to their isotropic nature and exhibiting high resistivity to eliminate eddy current loss in the magnet. MQ1 magnets also exhibit excellent thermal characteristics, maintaining their performance across a wide temperature range. These features make them particularly suitable for demanding applications such as automotive accessories and home appliances, where motors can either experience significant temperature fluctuations and/or require superior energy efficiency
Engineering researchers have developed a next-generation miniature lab device that uses magnetic nano-beads to isolate minute bacterial particles that cause diseases
New global regulations are being implemented, with the intent of reducing pollutants, greenhouse emissions, and continuing improvements in fuel economy. This has caused OEMs to accelerate vehicle electrification in recent years. One of the key components of the electric drive unit is an electric motor (eMotor) constructed with a significant amount of magnet wire (MW). The MW is composed of a copper wire coated with a polymeric insulation material. Other insulation materials found in the eMotor are slot liner, wedge, phase separator, heat shrinkable materials, varnish, etc. However, MW compatibility with electric transmission fluids (ETFs) is the most important performance criteria as poor compatibility can lead to a decrease in performance, electrical short, and even cause catastrophic eMotor failure. This paper discusses new insights gained around MW compatibility with various ETFs. The testing procedures described are MW sample preparation, sample aging method, test equipment, and
Kwak, YungwanGrzyska, PiotrCleveland, ChristopherTsuneo, Adachi
An EESM (Externally Excited Synchronous Motor) consists of a rotor with wound copper wires. One of its benefits is the ability to control the rotor electromagnetically with the rotor current, which is an advantage over an IPMSM (Internal Permanent Magnet Synchronous Motor). To practically use it and achieve optimal NVH quietness performance, the air- gap shape was redesigned to generate a sinusoidal curved magnetic flux density distribution. This differs from the standard design, in which the air gap has the same circumference as the rotor and stator. There was a significant reduction in the high-order magnetic flux density, which did not affect the torque. In addition, there was a reduction in the excitation force and minimal iron loss. Unlike an IPMSM, which only uses magnets and produces less heat, the copper wires of the EESM rotor generate heat as current flows through them. To maintain power density, it is important to ensure optimal cooling performance. A new cooling structure
Fan, XuWada, Hiroki
Linear motors have redefined what’s possible in motion control with faster, more precise, and more reliable performance compared to traditional, rotary motor-driven linear actuators. A linear motor’s unique property is that the load is moved without mechanical power transmission components. Instead, the linear force generated by the magnetic field of the motor coil is directly coupled to the load. This eliminates mechanical devices that convert rotary motion to linear, thus enhancing the system’s life, precision, speed, and overall performance
A new project at Aalto University is developing techniques that will enable immobilized patients to control devices using their brain activity. The project builds on the multi-locus transcranial magnetic stimulation (mTMS) technology developed at Aalto, adapting it into a brain–computer interface (BCI) that can help patients with neurological conditions
Magnets generate invisible fields that attract certain materials. A common example is fridge magnets. Far more important to our everyday lives, magnets also can store data in computers. Exploiting the direction of the magnetic field (say, up or down), microscopic bar magnets each can store one bit of memory as a zero or a one — the language of computers
On the near-atomic level, magnetism is made of many ever-shifting kingdoms — called magnetic domains — that create the magnetic properties of the material. While scientists know these domains exist, they are still looking for the reasons behind this behavior
This specification covers nonfluorescent magnetic particles in the form of a mixed, ready-to-use suspension in an odorless oil vehicle and packaged in aerosol cans
null, null
This specification covers nonfluorescent, magnetic particles having black, red, gray, or other color, as specified, supplied in the form of dry powders
AMS K Non Destructive Methods and Processes Committee
Industrial robots are more affordable than ever for precision assembly and high-speed picking/packing tasks. With improvements to capabilities like vision, each new generation delivers more human-like dexterity and flexibility. A reliable and cost-effective sense of touch now lets them handle fragile objects to fulfill an even wider variety of tasks and interact more safely with humans
Stress-relief annealing is an indispensable processing step for non-oriented electrical steel (NOES) sheets to achieve optimal magnetic properties. The annealing microstructure and texture are not only dependent on the annealing conditions, but also on the prior thermomechanical processing history. To investigate the effect of deformation mode on the recrystallization behavior, a NOES containing 0.9 wt% Si was cold rolled by skew rolling in which the hot-rolled-and-annealed plate was fed at 45° into the rolls to change both the initial texture and the deformation mode. The skew-cold-rolled sheets and those rolled by conventional and cross rolling were then annealed at different temperatures (650 to 1050 °C) for different times (0.5 to 30 min). The recrystallization behavior was characterized using electron backscatter diffraction (EBSD) techniques. It was found that the cold rolling deformation mode and the initial texture have a significant effect on the recrystallization behavior
He, YouliangSanjari, Mehdi
Traditional vector control needs the installation of mechanical sensors to gather rotor position and speed information in order to enhance the control performance and dynamic quality of electric vehicle wheel motors, which increases system cost and reduces system reliability and stability. On the basis of Popov's super-stability theory, an appropriate adjustable model and reference model are constructed, and the system's reference adaptive law is determined. Furthermore, to solve the problem of the standard PI regulator's poor anti-interference capabilities in speed controllers, the approach of utilizing a sliding-mode speed controller in the speed loop is presented. Finally, a MATLAB/SIMULINK simulation model is created to simulate the motor in three scenarios: no-load start, abrupt speed change, and sudden load change, and a permanent magnet synchronous motor experimental platform is created to validate the control approach. The findings demonstrate that this technique can estimate
Qian, KaiWang, TaoZou, XiaojunSong, WeiYuan, LiukaiWang, Liangmo
This paper presents the design of Interior Permanent Magnet Synchronous motor (IPMSM) using Soft Magnetic Composite (SMC) material for Electric Vehicle (EV) applications. In EV, the electric motor is characterized by high power density, high torque, low weight and cost efficient. The high torque, high power to weight ratio and high mechanical strength Synchronous Motor along with the SMC structures will make it suitable candidate for such an EV application. With this focus the new SMC material Somaloy 3P is proposed as a motor core material. The SMC material is made up of iron powder particle coated with an electrically insulated layer which gives a unique 3D flux property. This material provides low eddy current losses because of high material resistance. The benefits of Somaloy 3P material for design of electric motor are compact, high performance, weight reduction and cost efficient. The impacts of Soft magnetic composite in IPMSM have been investigated through Electromagnetic
B, VidhyaShroff, RoopeshSabnis, Avdhut
Electrical steels are silicon alloyed steels that possess great magnetic properties, making them the ideal material choice for the stator and rotor cores of electric motors. They are typically comprised of laminated stacks of thin electrical steel sheets. An electric motor can reach high temperatures under a heavy load, and it is important to understand the combined effect of temperature and load on the electrical steel’s performance to ensure the long life and safety of electric vehicles. This study investigated the fatigue strength and failure behavior of a 0.27mm thick electrical steel sheet, where the samples were prepared by a stamping process. Stress-control fatigue tests were performed at both room temperature and 150°C. The S-N curve indicated a decrease in the fatigue strength of the samples at the elevated temperature compared to the room temperature by 15-25 MPa in the LCF and HCF regimes, respectively. Looking at the fracture surface, the room temperature samples at both
Gill, GurmeetBehravesh, BehzadSaha, DulalZhang, WenshengChen, JimLamonaca, GianniMills, MarieJahed, Hamid
Magneto-Rheological (MR) Fluid started to be used for industrial applications in the last 20 years, and, from that moment on, innovative uses have been evaluated for different applications to exploit its characteristic of changing yield stress as a function of the magnetic field applied. Because of the complexity of the behavior of the MR fluid, it is necessary to perform lots of simulations, combining multi-physical software capable of evaluating all the material’s characteristics. The paper proposes a strategy capable of quickly verifying the feasibility of an innovative MR system, considering a sufficient accuracy of the approximation, able to easily verify the principal criticalities of the innovative applications concerning the MR fluid main electromagnetic and fluid-dynamic capabilities. The procedure follows the main steps: 1. design the solution (functionally related to the MR principles); 2. steady-state analyses (performed respectively with Altair Flux and Altair Acusolve
de Carvalho Pinheiro, HenriqueImberti, GiovanniCarello, Massimiliana
Ionospheric variability is a critical consideration for communication systems, GNSS, and space asset management. At high magnetic latitudes, the convergent magnetic field acts as a lens, focusing electromagnetic power originating from solar wind-magnetosphere interactions into a limited latitudinal range. The geometry and ensuing complex coupling processes result in extreme multi-scale time-dependent variations in the structure and composition of the ionized gases in Earth’s outer atmosphere. Understanding the mechanisms and technological consequences of these interactions benefits from distributed heterogeneous time-dependent measurements of the ionosphere-thermosphere-magnetosphere system, and their application as constraints on predictive space weather models
Innovators at NASA Johnson Space Center have designed an apparatus and method that controls the growth and proliferation of 3D biological cells and mammalian tissue in the presence of a pulsating, alternating ionic magnetic resonance field (AIMR). The technology applies a spectrum of electromagnetic fields to control the growth of all mammalian cells and tissues while simultaneously enabling cellular dedifferentiation and lifespan extension through the control of ionic transport and particular ion frequency resonances
The reactionless drive is an internal momentum engine which until recently has been deemed impossible under the laws of physics. In this paper, the authors will extend the equation for reaction less propulsion = F=−μq2/6πcmr2v×dBdt+B×dvdt and derive an additional equation, which we call “The Sektet Equation” governing the system of motion, FSek=−μq2/6πcmr2∗2B∗dBdt. The results of the paper show that significant thrusts can be generated on relatively low voltages and energy inputs. It applies this equation to explain how NASA’s EM drive likely produces thrust via the “Sektet Equation” using a three circuit analysis of the Sektet Force
Chen, EdCronin, Tara
About 25 percent of the U.S. population suffers from fatty liver disease, a condition that can lead to fibrosis of the liver and, eventually, liver failure. Currently there is no easy way to diagnose either fatty liver disease or liver fibrosis. However, MIT engineers have now developed a diagnostic tool, based on nuclear magnetic resonance (NMR), that could be used to detect both of those conditions
Items per page:
1 – 50 of 1916