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A prototype of a type A quadrupole magnet has been designed and manufactured for the 3 GeV storage ring of Siam Photon Source II, the second synchrotron light source in Thailand. The required quadrupole gradient is 51 T/m with the magnet effective length being 162 mm. Magnet modeling and magnetic field calculation were performed using Radia and Opera-3D. The bore radius of the magnet is 16 mm. The magnet will be operated at the excitation of 5544 A-turns. A mechanical analysis of the magnet structure was performed in SOLIDWORKS and ANSYS, where the maximum deformation of 0.003 mm was found at the magnet poles, and the first-mode natural frequency was higher than 100 Hz. The magnet yoke is made of AISI 1006 low-carbon steel with a fabrication tolerance of ±0.020 mm. Magnet coils are water-cooled and made of high-purity copper. The temperature rise of the coils was below 3.0 °C at the maximum excitation of 6664 A-turns, which is 20% above the operating point. Magnetic field measurement was carried out using the Hall probe technique. The measured magnetic field and coil temperature of the prototype show good agreement with the calculations.

An electric dipole magnet quite similar to that of the IRANCYC10 cyclotron was designed and constructed to conduct the initial tests on the internal Penning ion source to be installed in the cyclotron. This magnet which was designed and constructed in the department of physics, University of Tehran, is capable of producing a magnetic field of 7000 G in the location of the source, a region in the center of the magnet with the radial extent of 15 mm, with no need for cooling. Magnetic fields as high as 1.1 T are also accessible for a few minutes. The ion source in IRANCYC10 is expected to be exposed by a magnetic field of 1100 G. The measurements show that the magnetic field in the location of the source is homogeneous with the maximum deviation value of 1.1% with respect to the magnetic field strength at the center. The magnet is H type with 100 mm pole diameter and 60 mm gap size. Comsol, Ansys Maxwell and SolidWorks codes were employed in the design and construction of the electric dipole magnet.

Esophageal atresia (EA) repair can be complicated by associated malformations such as a tracheobronchial remnant in the distal esophagus. We describe our experience with a patient found to have long-gap EA with a distal cartilaginous ring who was managed using a combination of esophageal lengthening and magnetic compression anastomosis. A 5-month-old girl was referred to us from an outside hospital with type C EA including a very high upper pouch. She had undergone a prior thoracotomy with fistula ligation during which a clip was placed on the lower esophagus, leaving a 2-cm diverticulum on the trachea and a short lower esophageal pouch. Upon endoscopic evaluation at our center, we found a tracheobronchial remnant in the lower esophagus between the clip and the carina. An open thoracotomy was performed to approximate the esophageal pouches and a magnet anchor (Connect EA, Myka Laboratories, San Francisco, California, United States) was placed retrograde through the distal esophageal cartilaginous ring into the lower pouch. On postoperative day 8, after adequate growth and decreased pouch tension, a second magnetic anchor was placed endoscopically to the upper pouch to mate with the previously placed lower pouch anchor. The anastomosis formed within 14 days. Due to the tracheobronchial remnant, the device did not pass distally and was removed endoscopically. On postoperative day 8, balloon dilation of the anastomosis and tracheobronchial remnant was performed. Subsequently, the patient required a total of 6 dilations in an 18-month follow-up. This case report illustrates the utility of using magnets to create an esophageal anastomosis in complex cases of EA with concomitant esophageal malformations. The parents of the patient gave their written consent to publish this technical report.

Magnetic drug delivery is an effective method to decrease the side effects of traditional drug delivery methods. To enhance the efficiency of magnetic nanoparticle transport, a precise and cost-effective magnetic system is required. In this research, different arrangements of NdFeB magnets for drug delivery in human spinal cord were presented and then compared. Assummed magnetic nanoparticles are injected into the cerebrospinal fluid (CSF) and focused on the disease site with external magnets. The effects of these magnets on nanoparticles have been investigated. The results show that the arrangement of sharp magnets has a more accurate performance in delivering nanoparticles to the damage site than other arrangements. The designed magnetic system can improve the accuracy of drug delivery in the spinal cord compared to previous methods. To enhance the efficiency of magnetic nanoparticle transport, a precise and cost-effective magnetic system is required. In this research, various configuration of permanent NdFeB magnet is used to conduct magnetic drugs to the target in the spinal cord. Besides, the behavior of magnetic nanoparticles in magnets fields is analyzed. [ABSTRACT FROM AUTHOR]

It is often assumed that people experiencing homelessness gravitate to large cities and central city areas because of the concentration of homelessness services — a so-called magnet or honeypot effect. Yet little is actually known about how people experiencing homelessness move across space over time. This article explores this geography by comparing the mobility of those experiencing homelessness, those 'at-risk', and those renting privately in Australia, between waves in two Australian panel surveys: Journeys Home and the Household, Income and Labour Dynamics in Australia (HILDA). Results suggest that while people experiencing homelessness are more likely to move than the other two groups, they more similarly short distances and appear more likely to move for reasons such as relationship breakdown, eviction and to escape violence. While some evidence of movement to areas with particular characteristics (sorting) was detected amongst those at-risk and those renting privately, this was not the case for those experiencing homelessness. Results do not support the contention that people experiencing homelessness gravitate to central urban areas well-resourced with homelessness services over time. The findings challenge assumptions about magnet effects and homelessness and have important implications for the provision and delivery of homelessness services in Australia and beyond. [ABSTRACT FROM AUTHOR]

The possibility of applying additive technology of selective laser melting for preparing specimens from hard magnetic alloy 25Kh15KA is considered. Melt spraying is used to prepare initial powders for melting with a good yield and adaptability to additive manufacturing. Experimental cylindrical samples with a size of ∅10 × 12 mm and ring magnets with an outer diameter of 46 mm, an inner diameter of 37.8 mm, and a height of 6 mm, are prepared. Microstructures of the specimens are studied and magnetic parameters are measured. Conformity of the properties of magnets produced by additive technology and cast magnets is demonstrated. A novel method of structure multifractal analysis is used to show that synthesized magnets are resistant to external effects. [ABSTRACT FROM AUTHOR]

Many patients with cochlear implants (CI) and auditory brainstem implants (ABI) require magnetic resonance imaging (MRI) following implantation. This study explores the patient experience of MRI, identifying factors associated with pain, and the effect of interventions designed to enhance comfort and safety. A prospective observational case series from a tertiary referral unit. Tight head bandaging ± local anaesthetic injection (devices with non-MRI-compatible magnets) or observation alone (implants with MRI-compatible magnets) were employed for 1.5 T MRI of consecutive adult patients with CI or ABI without magnet removal. Pain was recorded via visual analogue scale (1 = no pain, 5 = extreme pain) at three time points; (1) baseline, (2) head bandage applied (3) during scanning. Patient age, device type, body area imaged and total scan time were recorded as variables, alongside adverse events. Data were collected for 227 MRI scans (34 patients with ABI, 32 with CI). In patients managed with bandaging, pain score after bandaging but prior to scanning (median 2.2) did not differ from pain during scanning (2.1), but both were significantly higher than baseline (1.4, both P ≤ 0.001). Scanning areas other than the head/cervical spine was associated with higher pain scores (P = 0.036). Pain during MRI differed between different manufacturers implants (P ≤ 0.001). Adverse events occurred in 8/227 scans (3.5%), none occurring with devices containing an MRI-compatible magnet. MRI scanning with auditory implant magnets in situ is safe and well tolerated by patients. [ABSTRACT FROM AUTHOR]

Adverse reactions in tattooed skin during magnetic resonance imaging (MRI) are rare but well known. Previous reports describe sudden burning pain in tattooed skin, sometimes accompanied by mild erythema and oedema when entering MRI scanners. The pathophysiology remains unclear, but simple direct thermal heating can be excluded. It has been hypothesized that MRI-triggered torque and traction create neural sensations from magnetic pigment particles. However, this case enlightens yet another possible mechanism. We present a 35-year-old woman experiencing reoccurring stinging sensations in three decorative black tattoos just seconds after the initiation of the MRI. Single-blind tests with handheld power magnets or a dummy could reproduce painful subjective feelings in her tattooed skin. Similar events were provoked during re-evaluation with MRI. Surprisingly, chemical analyses and electron microscopy of skin samples revealed carbon black as the colouring agent – no iron-based solids were detected. Our case demonstrates that MRI tattoo reactions are not limited to magnetic contaminants alone. More distinct subgroups of MRI-induced reactions may occur. We hypothesize that radiofrequency induction of surface currents in black carbon particles adjacent to sensory axons in the dermis may lead to neurosensations.

L’any 2022, a Manresa s’ha realitzat la primera edició de la Mobile Week amb l’objectiu d’apropar les tecnologies digitals a la ciutat. Des de l’Institut Guillem Catà, a partir del projecte «Magnet-UPC», vam proposar de participar-hi fent la projecció d’un mapping a la façana del centre cultural més gran de la ciutat, el Casino, situat al passeig de Pere III. Així, el dia 6 de maig es va poder dur a la pràctica fruit d’un treball amb l’alumnat de segon d’ESO des de les optatives de robòtica, de visual i plàstica i també de música. Per als nostres alumnes de segon d’ESO l’objectiu era fomentar la creativitat mitjançant tecnologies digitals. Metodològicament, vam seguir el treball conjunt STEAM (science, technology, engineering, arts and mathematics), que implica un treball cooperatiu des de diferents disciplines. El resultat ha estat un exercici rodó que ens ha permès explorar nous terrenys de la creativitat i l’aplicació tecnològica, i que ha repercutit clarament no només en l’entorn immediat de l’Institut sinó a tota la ciutat de Manresa. En conclusió, l’exercici ha esdevingut un veritable estímul a la creació i la recerca entre nois i noies que no en tenien pas experiències prèvies. I és per aquest motiu que ja estem pensant de repetir-lo milloradament el proper curs.

Key Clinical Message Multiple neodymium magnets can pinch tissue and cause barotrauma. Be careful if the tissue of the penis or foreskin is pinched, as this may cause foreskin necrosis or damage to the urethra.

Background and objectivesA totally implantable venous access port (TIVAP) is a commonly used intravenous infusion device for patients receiving chemotherapy or long-term infusion therapy. To improve the success rate of one-time insertion of the Huber needle, we developed a novel Y-Z magnetic TIVAP (Y-Z MTIVAP), which we produced using three-dimensional printing technology.Materials and methodsThe Y-Z MTIVAP includes a magnetic port body and a magnetic positioning device. For testing, we established four venous port implantation models using the two types of TIVAPs and two implantation depth ranges (≤5 mm and >5 mm). Twenty nurses performed Huber needle puncture with the four models, and we recorded the number of attempts required for successful needle insertion, the operation time, and the operator's satisfaction.ResultsThe success rate for one-time needle insertion with the Y-Z MTIVAP was significantly higher than that with the traditional TIVAP at either depth range (100% vs. 75% at ≤5 mm, p = 0.047; 95% vs. 35% at >5 mm, p 5 mm, p = 0.025), but the success rate with the Y-Z MTIVAP was not significantly affected (100% vs. 95%, p = 1.000). The operation time with the Y-Z MTIVAP was significantly shorter than that with the traditional TIVAP at either depth range (both p

In this paper, we present the development of a high-efficiency electronic commutated (EC) motor using nonoriented electrical steel produced by China Steel Corporation for window-type air-conditioning system applications. The EC motor combines the highly efficient brushless DC electric motor, Hall-effect sensor, driver, and AC/DC converter, but it has similar volume and equivalent performance to the traditional AC motor. By analyzing the material properties and using simulation tools, an EC motor with a high efficiency of about 82–86.4% is demonstrated in this study. A system manufacturer can replace the AC motor with an EC motor directly in the air-conditioning system for higher performance and save more energy, without altering the mechanical design. [ABSTRACT FROM AUTHOR]

The bore diameters of magnets and envelopes of beams in a low energy beam transport (LEBT) system should be large. The large diameter of magnet expands the fringe field as the fringe field distribution depends on the aperture size of the magnet. To avoid magnetic field interference and prevent damage, we investigate the fringe field distribution of a magnet. Further, we present two beam dynamics case studies, wherein all the requirements of a multi-purpose application system using different acceleration modes for neutron generation and implantation are satisfied. Providing energies between a few tens to hundreds of kiloelectronvolts, is an essential apparatus for material science studies in the low energy-region. Considering the fringe field effect of the developed magnets, the LEBT system has been re-designed to satisfy these requirements. We describe the magnetic field distributions in terms of beam dynamics parameters, and discuss it with regard to the two operation modes. [ABSTRACT FROM AUTHOR]

The in-flight fragment (IF) separator of RAON, the main device for producing rare isotope (RI) beams for nuclear science research and applications, is under development. The IF separator consists of a target, beam dump, magnets, and detector systems. The high-power target and beam dump for the 80 kW primary beam were fabricated using graphite. The IF magnet system consists of a total of 8 dipole magnets, 15 sets of quadrupole magnet triplet, 2 sextupole magnets, and power supply systems. In the high radiation region near the target and beam dump, warm iron high temperature superconducting (HTS) magnets and radiation-resistive dipole magnet are used. In the other region, cold iron low temperature superconducting (LTS) quadrupole magnet triplets and normal conducting (NC) dipole and sextupole magnets are used. Fabrication of all IF magnets have been completed and on-site installation is in progress. Also, detectors for particle identification (PID) and data acquisition (DAQ) systems are currently being installed at the focal planes of the IF separator. The current status of IF separator is briefly introduced. [ABSTRACT FROM AUTHOR]

Pin-based shape-changing displays provide dynamic shape changes by actuating numerous pins. However, the large number of actuators required to move so many pins complicates the electrical path and mechanical structure, and creates a need for significant resources if one is to build such a display. Therefore, my research colleague and I proposed a simple pin-based shape-changing display, called MagneShape, that outputs shapes and motions without any electronic components. MagneShape consists of magnetic pins, a pin housing, and magnetic sheet. The magnetic force generated between the magnetic sheet and the magnetic pins levitates the pins vertically. We devised two methods for fabricating alternative magnetic pins, devised a method for controlling the magnetic pins, and developed design tools for MagneShape. [ABSTRACT FROM AUTHOR]

This paper introduces a novel swarm-based metaheuristic called swarm magnetic optimizer (SMO). SMO imitates the behaviour of two magnets close to each other: pushing toward or pulling away from each other. This pushpull mechanism is then adopted to become a novel search in SMO. SMO is set up as a swarm of magnets that move autonomously. In the early iteration, the pull strategy is dominant. Meanwhile, it declines during the iteration and is replaced by a push strategy. The determination between these two strategies is calculated stochastically. SMO consists of three sequential phases in every iteration where the corresponding magnet and its reference run a push or pull search in each phase. The reference used in each phase is the global best magnet, a randomly selected magnet, and a randomly generated magnet. This paper evaluates SMO through simulation to find the optimal solution for 23 functions. The performance of SMO is compared with five latest metaheuristics: mixed leader-based optimizer (MLBO), guided pelican algorithm (GPA), zebra optimization algorithm (ZOA), coati optimization algorithm (COA), and clouded leopard optimizer (CLO). The result shows that SMO is better than MLBO, GPA, ZOA, COA, and CLO in consecutively 22, 15, 11, 13, and 14 functions. The superiority of SMO, especially, is in solving high dimension functions. Meanwhile, in the fixed-dimension multimodal functions, SMO is still superior to MLBO but less superior to GPA, ZOA, COA, and CLO. [ABSTRACT FROM AUTHOR]

Purpose: Slender boring bars vibrate when excited by cutting forces to result in chatter. These chatter vibrations damage the part and the tool and hence must be avoided and/or suppressed. Usually, tuned absorbers integrated within the boring bar dissipate the motion of the boring bar and make stable cutting possible. However, since the boring bar's dynamics change with loading and boundary conditions, optimally tuning the absorber becomes difficult. This prevents stable high-performance cutting. To improve the cutting performance of a potentially detuned absorber within a boring bar, this paper presents a novel hybrid damping solution. The hybrid damper is composed of an absorber working in conjunction with an eddy current damper. Methods: To demonstrate the working of this hybrid damper, we model the boring bar as an Euler–Bernoulli beam. A permanent magnet is supported by a spring and damper within a copper section of a boring bar. The supported magnet acts as an absorber and the relative motion between the conductive copper bar and the magnetic field induces eddy currents that hinder the motion of the boring bar. Governing equations for the beam with an integrated damper are obtained by applying the extended Hamilton's principle. Eddy current damping is evaluated by applying the Lorentz force law and the Biot–Savart law. Results: Our analysis suggests that the improvement in the chatter-free depth of cut with a hybrid damper over the case with a detuned absorber is as much as ~ 500%. And, when the absorber is optimally tuned and the hybrid damper takes its maximum possible value, the chatter-free depth of cut for both cases was found to be the same, suggesting that if/when the absorber can be optimally tuned, the eddy current damper offers no additional benefit. Conclusion: Since optimally tuning an absorber is difficult, our proposed hybrid damper offers a feasible solution to improve cutting performance with slender boring bars. Moreover, since our models are generalized, the approach may also be used to explore the integration of such hybrid dampers within other tooling systems such as milling tool holders. [ABSTRACT FROM AUTHOR]

A prototype of a type A quadrupole magnet has been designed and manufactured for the 3 GeV storage ring of Siam Photon Source II, the second synchrotron light source in Thailand. The required quadrupole gradient is 51 T/m with the magnet effective length being 162 mm. Magnet modeling and magnetic field calculation were performed using Radia and Opera-3D. The bore radius of the magnet is 16 mm. The magnet will be operated at the excitation of 5544 A-turns. A mechanical analysis of the magnet structure was performed in SOLIDWORKS and ANSYS, where the maximum deformation of 0.003 mm was found at the magnet poles, and the first-mode natural frequency was higher than 100 Hz. The magnet yoke is made of AISI 1006 low-carbon steel with a fabrication tolerance of ±0.020 mm. Magnet coils are water-cooled and made of high-purity copper. The temperature rise of the coils was below 3.0 °C at the maximum excitation of 6664 A-turns, which is 20% above the operating point. Magnetic field measurement was carried out using the Hall probe technique. The measured magnetic field and coil temperature of the prototype show good agreement with the calculations. [ABSTRACT FROM AUTHOR]

Adverse reactions in tattooed skin during magnetic resonance imaging (MRI) are rare but well known. Previous reports describe sudden burning pain in tattooed skin, sometimes accompanied by mild erythema and oedema when entering MRI scanners. The pathophysiology remains unclear, but simple direct thermal heating can be excluded. It has been hypothesized that MRI-triggered torque and traction create neural sensations from magnetic pigment particles. However, this case enlightens yet another possible mechanism. We present a 35-year-old woman experiencing reoccurring stinging sensations in three decorative black tattoos just seconds after the initiation of the MRI. Single-blind tests with handheld power magnets or a dummy could reproduce painful subjective feelings in her tattooed skin. Similar events were provoked during re-evaluation with MRI. Surprisingly, chemical analyses and electron microscopy of skin samples revealed carbon black as the colouring agent – no iron-based solids were detected. Our case demonstrates that MRI tattoo reactions are not limited to magnetic contaminants alone. More distinct subgroups of MRI-induced reactions may occur. We hypothesize that radiofrequency induction of surface currents in black carbon particles adjacent to sensory axons in the dermis may lead to neurosensations. [ABSTRACT FROM AUTHOR]

Energy harvesting effectively powers micro-sensors and wireless applications. However, higher frequency oscillations do not overlap with ambient vibrations, and low power can be harvested. This paper utilizes vibro-impact triboelectric energy harvesting for frequency up-conversion. Two magnetically coupled cantilever beams with low and high natural frequencies are used. The two beams have identical tip magnets at the same polarity. A triboelectric energy harvester is integrated with the high-frequency beam to generate an electrical signal via contact-separation impact motion between the triboelectric layers. An electrical signal is generated at the low-frequency beam range achieving frequency up-converter. The two degrees of freedom (2DOF) lumped-parameter model system is used to investigate the system's dynamic behavior and the corresponding voltage signal. The static analysis of the system revealed a threshold distance of 15 mm that divides the system into monostable and bistable regimes. In the monostable and bistable regimes, softening and hardening behaviors were observed at low frequencies. Additionally, the threshold voltage generated was increased by 1117% in comparison with the monostable regime. The simulation findings were experimentally validated. The study demonstrates the potential of using triboelectric energy harvesting in frequency up-converting applications. [ABSTRACT FROM AUTHOR]

Mechanical energy from vibrations is widespread in the ambient environment. It may be harvested efficiently using triboelectric generators. Nevertheless, a harvester's effectiveness is restricted because of the limited bandwidth. To this end, this paper presents a comprehensive theoretical and experimental investigation of a variable frequency energy harvester, which integrates a vibro-impact triboelectric-based harvester and magnetic nonlinearity to increase the operation bandwidth and improve the efficiency of conventional triboelectric harvesters. A cantilever beam with a tip magnet was aligned with another fixed magnet at the same polarity to induce a nonlinear magnetic repulsive force. A triboelectric harvester was integrated into the system by utilizing the lower surface of the tip magnet to serve as the top electrode of the harvester, while the bottom electrode with an attached polydimethylsiloxane insulator was placed underneath. Numerical simulations were performed to examine the impact of the potential wells formed by the magnets. The structure's static and dynamic behaviors at varying excitation levels, separation distance, and surface charge density are all discussed. In order to develop a variable frequency system with a wide bandwidth, the system's natural frequency varies by changing the distance between the two magnets to reduce or magnify the magnetic force to achieve monostable or bistable oscillations. When the system is excited by vibrations, the beams vibrate, which causes an impact between the triboelectric layers. An alternating electrical signal is generated from a periodic contact-separation motion between the harvester's electrodes. Our theoretical findings were experimentally validated. The findings of this study have the potential to pave the way for the development of an effective energy harvester that is capable of scavenging energy from ambient vibrations across a broad range of excitation frequencies. The frequency bandwidth was found to increase by 120% at threshold distance compared to the conventional energy harvester. Nonlinear impact-driven triboelectric energy harvesters can effectively broaden the operational frequency bandwidth and enhance the harvested energy. [ABSTRACT FROM AUTHOR]

Recently, high-speed motors are receiving a lot of attention in the industrial field. When driving a motor at high speed, the advantages include high power density, high efficiency, and miniaturization. However, the disadvantages of the high-speed operation of motors are mechanical and structural safety. This is because the bearings used in high-speed motors require characteristics such as precision and low friction. There are two prominent types of bearings mainly used in high-speed motors: rolling bearings and magnetic bearings. A feature of rolling bearings is that they reduce frictional resistance by contacting points or lines between the shaft and the bearing. However, the disadvantages of rolling bearings are high mechanical friction losses due to the need for contact with the lubrication system. Maintenance costs are high. For this reason, a lot of research on bearings is being conducted to reduce the frictional loss of bearings and increase their efficiency and reliability. Bearings that are advantageous for high-speed operation are magnetic bearings that do not require lubricants, have no friction loss, and have low maintenance. However, magnetic bearings have disadvantages such as high cost and difficulty in miniaturization. In this paper, a stator with a separated teeth structure was used to compensate for these disadvantages. Using this, a model with miniaturization, light weight, and high manufacturability was proposed. The model name proposed in this study is called the STMB (separated teeth magnetic bearing). There are also disadvantages of the STMB model proposed in this paper. A model that compensates for this drawback is called the HSTMB (hybrid separated teeth magnetic bearing). The HSTMB reduces the weight by removing the back yoke of the stator and has advantages of a high filling rate and high productivity in the form of a module. As a result, high productivity, light weight, and high performance are possible when the HSTMB is applied, which was proven through FEA (finite element analysis). [ABSTRACT FROM AUTHOR]

The ingestion of foreign bodies is a very common emergency in the pediatric age. 80-90% will be expelled without problem, while 10-20% will require endoscopic extraction, and close to 1% will occasionally require surgical intervention. The ingestion of neodymium magnets (rare earth magnets) is increasingly frequent since they are commonly part of toys, accessories or ornaments, they are 5 to 20 times more powerful than conventional iron compound magnets. The vast majority of these accidental ingestions are unnoticed by the parents and the diagnosis is given at the onset of gastrointestinal symptoms such as abdominal pain, nausea, vomiting, although on occasions they may be asymptomatic and/or as a radiological finding. We present the clinical case of a 2-year-old male, with a history of autism, who was admitted due to abdominal pain, in whom foreign body ingestion (magnets) was noted when performing an abdominal X-ray, in different locations, requiring exploratory laparotomy, finding internal hernia secondary to enteroenteric fistula as a finding, as well as multiple entero-enteral fistulas. [ABSTRACT FROM AUTHOR]

The novel use of magnetic force to optimize modern surgical techniques originated in the 1970s. Since then, magnets have been utilized as an adjunct or alternative to a wide array of existing surgical procedures, ranging from gastrointestinal to vascular surgery. As the use of magnets in surgery continues to grow, the body of knowledge on magnetic surgical devices from preclinical development to clinical implementation has expanded significantly; however, the current magnetic surgical devices can be organized based on their core function: serving as a guidance system, creating a new connection, recreating a physiologic function, or utilization of an internal–external paired magnet system. The purpose of this article is to discuss the biomedical considerations during magnetic device development and review the current surgical applications of magnetic devices. [ABSTRACT FROM AUTHOR]

High-density on-board optical connectors are necessary for next-generation optical interconnects such as co-packaged optics in datacenter networks. To break through the size limitation of current optical connectors, we proposed the concept of introducing a magnetic attraction structure into an optical-fiber connector. We previously developed simplex and multi-fiber connectors on the basis of this concept. This article reviews the design and fabrication results of our developed multi-fiber magnetic connector, which provided low-insertion losses comparable to those of conventional multi-fiber push-on connectors while achieving space-saving connection. [ABSTRACT FROM AUTHOR]

Sensitive measurements require a vibration isolation system to safeguard against detrimental tremble. Two types of vibration isolation systems - passive and active - are currently implemented. The spring-based passive designs usually accompany with ineffective low-frequency response. Therefore, the active designs, consisting of sensors, feedback control systems, and actuators, are consolidated to improve the total effectiveness of the cancellation performance. In this work, we focus on developing the actuator founded on electromagnetic spring to be incorporated into our compact quantum gravimeter. Each spring-actuated part comprises two repelling Nd magnets positioned face to face inside a solenoid. With this configuration, the spring can also work in the passive mode via repulsive magnetic force. In the active mode, the exerted force is a result of magnetic fields formed by the magnets and the current-controlled solenoid coils. By changing the coil current, the stiffness of the spring can be modified, and thus the displacement can be controlled. Different sizes of magnets are explored, and their force behaviors in passive and active modes are characterized. The implementation scheme of the actuator in the quantum gravimeter is also discussed. [ABSTRACT FROM AUTHOR]

Objective: To evaluate cochlear implant (CI) magnet-related MRI artifact shape and size, as well as imaging indications and clinical adequacy of scans. Methods: A retrospective chart review was performed for patients undergoing CI and subsequent MRI head imaging from 2014 to 2020 at a single institution. Indications and adequacy of each scan was recorded, and interpretability compared by indication. Magnet-related artifact size was determined by performing ellipsoid modeling at axial slice of greatest signal loss. Artifact radius in centimeters was calculated for 5 sequence categories, and size compared between sequences, manufacturers, and by time from implantation. Results: Twenty patients underwent 58 head MRI scans. Approximately 76% of MRIs (n = 44) for 70% of patients (n = 14) were performed for indications known of prior to implantation; the remainder were performed during workup of new issues. Desired structures were interpretable in 23 (52%) of known-indication MRIs and 8 (57%) of new-indication MRIs, without significant difference (P =.751). Magnet-related artifact magnitude, compared to the reference T1-weighted fast spin echo (FSE) (4.47 cm), was similar in T2 FSE (4.57 cm, P =.068) and T1 gradient echo (GRE) sequences (4.79 cm, P =.28), but significantly greater in T2 GRE (6.86, P <.0001) and DWI (7.56 cm, P <.0001) sequences. Conclusions: DWI and T2 GRE sequences are less useful in MRI evaluation of CI patients. With a more favorable artifact profile, T1 FSE, T2 FSE, and T1 GRE sequences more likely yield clinically useful information. The large proportion of scans performed for known pathology represents an opportunity to optimize for magnet location preoperatively. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Accidental ingestion of magnetic foreign bodies has become more common due to the greater availability of toys with these elements, being a clinical problem between 6 months and 3 years of age, which must be treated promptly since they could cause life-threatening gastrointestinal complications. CLINICAL CASE: A 4-year-old male schoolboy, who presented abdominal pain of 4 days of evolution, colic type, intermittent, without other symptoms; clinically stable, the abdomen without data of peritoneal irritation. An AP and lateral standing X-ray of the abdomen is performed, which shows images of radiopaque foreign bodies (chain of magnets) in the gastric chamber and partial intestinal pneumatization. An endoscopy was performed where 4 spherical magnets embedded in the gastric mucosa that conditioned transmural perforation were visualized. An exploratory laparotomy was performed, finding a perforation in the posterior face of the gastric body that fistulized towards the jejunum and another mirror perforation in the colon, and a chain of 15 circumferential magnets was extracted from the gastric cavity. CONCLUSION: The ingestion of magnets must be diagnosed in a timely manner through a directed questioning, based on a simple abdominal X-ray, since this will define the diagnosis and early endoscopic and/or surgical treatment and thus avoid greater gastrointestinal complications secondary to the electromagnetic charge of the magnets, time of ingestion, location and number of foreign bodies. [ABSTRACT FROM AUTHOR]

In this manuscript we deal with recent advances in low-field Magnetic Resonance Imaging (MRI). The development of low-cost MRI solutions allowing portability and trustable diagnosis is a hot topic worldwide by these days. We analyze basic technical issues of recent examples of fixed-field instruments operating at low-field. Then we discuss pros and cons of the pre-polarized approach, from both physical and technical perspectives. Permanent magnet and electromagnet technology are confronted. Finally, magnetic field-cycling is introduced as an alternative MRI technique, where field-dependent experiments can be exploded for the development of new contrast mechanisms that are not feasible for fixed-field MRI instruments. As field cycled machines usually deals with switched currents in electromagnets, magnetic field instability and inhomogeneity are the main limiting factors affecting image quality. We finalize this manuscript discussing how it turns possible to overcome these limitations, thus opening new possibilities for the development of cost effective MRI technology.

In 2023, the manufacturing of all the ITER TF coils has been completed 15 years after the sign of procurement arrangements in 2008. This paper has been jointly submitted by F4E and QST to recollect the lessons learnt in the production of the two parties along the last 15 years.

A method for obtaining bremsstrahlung with a sequence of thin converters is proposed. Its advantages and disadvantages are described. Beam variation during the motion in this system is shown, and the results of estimate calculations are presented. [ABSTRACT FROM AUTHOR]

The current study uses the finite element technique to investigate a single-phase induction motor with non-uniform stator slots. A 0.5 hp, four poles, 36 stator slots, and 48 rotor slots have non-uniform stator slots was analyzed based on magnet Finite Element Method software with using AutoCAD in modeling stator due to its unsymmetrical slots, The suggested study attempts to evaluate all motor design modifications. The values of currents and torque received from the FEM analysis for test motor were compared with motor nameplate data with a good agreement.

The recent development of tough tissue adhesives has stimulated intense interests among material scientists and medical doctors. However, these adhesives have seldom been tested in clinically demanding surgeries. Here we demonstrate adhesive anastomosis in organ transplantation. Anastomosis is commonly conducted by dense sutures and takes a long time, during which all the vessels are occluded. Prolonged occlusion may damage organs and even cause death. We formulate a tough, biocompatible, bioabsorbable adhesive that can sustain tissue tension and pressurized flow. We expose the endothelial surface of vessels onto a gasket, press two endothelial surfaces to the adhesive using a pair of magnetic rings, and reopen the bloodstream immediately. The time for adhesive anastomosis is shortened compared to the time for sutured anastomosis. We have achieved adhesive anastomosis of a great vein in transplanting the liver of a pig. After the surgery, the adhesive is absorbed, the vein heals, and the pig lives for over one month.

Vibration and torque ripple of the permanent magnet generator axis cause excessive wearing up of the generator, noise, efficiency reduction. The article theoretically considers the possibility of eliminating the oscillation of the rotation torque of the permanent magnets generator at constant load due to mutual compensation of the interaction of coils with the field of permanent magnets in the case of certain symmetry of this field. This effect is called pi resonance. For a given class of model functions of the magnetic field density of permanent magnets, it is shown that full compensation occurs with a certain number of coils (Ns) and magnets (Nr), while for other combinations of {Ns, Nr} the interaction is in the nature of oscillations. Pi resonance tables are given for a number of model field density functions represented by Fourier series up to the fifth power. Pi resonance is primarily realized in the case of a small difference in the values of Nr and Ns, which corresponds to the location near the main diagonal of the pi resonance table, as well as at the values of Nr, Ns corresponding to prime numbers. The number of configurations {Nr, Ns} providing pi resonance (compensation of parasitic torques) is the largest for the sinusoidal magnetic flux density and decreases if the magnetic flux density function is approximated by a high-degree Fourier series. It is shown that in the absence of coil cores, pi resonance is possible at Nr = Ns. An additional possibility of pi resonance is shown when placing coils on opposite sides of the rotor. A simplified method of investigating the system (without integrating the equation for the induction current) is substantiated. The results can be used in the design of permanent magnets generators and motors.

Using energy harvesting to convert ambient vibrations efficiently to electrical energy has become a worthy concept in recent years. Nevertheless, the low frequencies of the ambient vibrations cannot be effectively converted to power using traditional harvesters. Therefore, a frequency up-conversion harvester is presented to convert the low-frequency vibrations to high-frequency vibrations utilizing magnetic coupling. The presented harvester consists of a low-frequency beam (LFB) and a high-frequency beam (HFB) with identical tip magnets facing each other at the same polarity. The HFB, fully covered by a piezoelectric strip, is utilized for voltage generation. The dynamic behavior of the system and the corresponding generated voltage signal has been investigated by modeling the system as a two-degrees-of-freedom (2DOF) lumped-parameter model. A threshold distance of 15 mm that divides the system into a monostable regime with a weak magnetic coupling and a bistable regime with a strong magnetic coupling was revealed in the static analysis of the system. Hardening and softening behaviors were reported at the low frequency range for the mono and bistable regimes, respectively. In addition, a combined nonlinear hardening and softening behavior was captured for low frequencies at the threshold distance. Furthermore, a 100 % increment was achieved in the generated voltage at the threshold compared to the monostable regime, and the maximum generated voltage was found to be in the bistable regime. The simulated results were validated experimentally. Moreover, the effect of the external resistance was investigated, and a 2 MΩ resistance was found to be optimal for maximizing the generated power. It was found that frequency up-converting based on magnetic nonlinearity can effectively scavenge energy from low-frequency external vibrations. [ABSTRACT FROM AUTHOR]

The fast development in the compact and wearable opto-electronics devices need a high-performance electromagnetic (EM) shielding materials that are shows a unique feature like lightweight and flexible in characteristics that increase the problems of electromagnetic pollution. At present technological aspects, the absorption predominant microwave shielding materials are gain the huge demand for preventing the major problems of electromagnetic interference over the modern electronic devices as well as environment. In the report we presents synthesis of multifunctional composite thin film material that adequately includes the exceptional EMI shielding, mechanical flexibility and magnetic properties of composite thin film for portable and wearable electronic devices which could be operated at GHz frequencies. The Co 0.5 Ni 0.5 Ce x Sm y Fe 2-x-y O 4 (denoted as CNCSF) its scanning electron microscopy (SEM) micrographs revel the fact that the samples highly agglomerated characteristics features of the prepared thin film samples, this agglomerated structure of the composite film will enhance the EMI shielding performances and strain sensing responses. Further, the prepared thin films were subjected to characterized XRD and Raman spectroscopic techniques to analyse the crystallinity and different functional groups present in the prepared thin films. By doping of samarium and cesium nanoparticles into the Co 0.5 Ni 0.5 Fe 2-x-y O 4 forms the superior conducting islands and enhances the dielectric and magnetic properties of the composite thin films. Owing to the improved dielectric and magnetic properties this x,y = 0.02 ferrites based thin film nanocomposite with the 0.4 mm thickness exhibit the absorption predominated outstanding electromagnetic shielding responses in the order of −23 dB which is almost equal to 99.67% of shielding efficiency in broad band microwave frequencies. Furthermore, these material-based nanocomposite shields show exceptional stability in EMI shielding efficiency under the different mechanical stretching strains. In addition to superior excellent shielding material, this material-based nanocomposite thin film shows an exceptional strain sensing behaviour, which evident that multifunctional applications of this ferrites based thin material. Owing to the all-unique properties like light weight, flexibility, outstanding EMI-SE and excellent strain sensing behaviour, these ferrites-based material thin film could be employed in flexible and fortable electronic devices as crafty jacket on shield. [ABSTRACT FROM AUTHOR]

In 2007, Diane Ream Rourke published in this journal, the history and explanation for Baptist Hospital in Florida to include its library on its successful Magnet journey. This article draws heavily from American Nursing Credentialing Center (ANCC) Magnet Information pages. It begins with a quick review of the history of the Program, further suggestions for a librarian's contribution to obtain Magnet Recognition and a brief current literature review on the values Magnet Recognition brings to a hospital's economics, patient care, and nursing staff. The quick history review and suggestions on the librarian contribution to the Magnet journey are based on an invited CE course by this author. The literature review on the values Magnet Recognition brings to a hospital's economics, patient care, and nursing staff was part of a presentation this author prepared for the Chief of Nursing. This author was a Magnet Champion and Magnet exemplar when Virtua Health first earned its first Magnet designation. [ABSTRACT FROM AUTHOR]

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