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Thin-film patterned magnetic nanostructures are widely employed within perceived magnonic device architectures to guide and/or manipulate spin waves for data processing and communication purposes. Here, using micromagnetic simulations, we explore how the internal magnetic field nonuniformity inherent to patterned magnetic nanostructures can also be exploited to create spin-wave sources. The spin-wave emission is achieved through the resonant excitation of finite-sized regions of increased effective magnetic field formed near the edges of patterned structures. The phenomenon is rather universal and could be used to generate magnetodipole, dipole-exchange, and exchange dominated spin waves. Depending on the frequency of excitation and parameters of the nanostructures, the emitted spin waves may form either highly directional spin-wave caustic beams or more regular plane spin waves.

The mechanism used to alter the features of propagating spin waves is a key component underpinning the functionality of high-frequency magnonic devices. Here, using experiment and micromagnetic simulations, we demonstrate the feasibility of a magnonic multiplexer in which the spin-wave beam is toggled between device output branches by the polarity of a small global bias magnetic field. Due to the anisotropy inherent in the dispersion of magnetostatic spin waves, the phase fronts of the output spin waves are asymmetrically tilted relative to the direction of the beam propagation (group velocity). We show how the phase tilts could be (partly) rectified in the magnonic waveguides of variable widths.

The wave solutions of the Landau–Lifshitz equation (spin waves) are characterized by some of the most complex and peculiar dispersion relations among all waves. For example, the spin-wave (“magnonic”) dispersion can range from the parabolic law (typical for a quantum-mechanical electron) at short wavelengths to the nonanalytical linear type (typical for light and acoustic phonons) at long wavelengths. Moreover, the long-wavelength magnonic dispersion has a gap and is inherently anisotropic, being naturally negative for a range of relative orientations between the effective field and the spin-wave wave vector. Nonuniformities in the effective field and magnetization configurations enable the guiding and steering of spin waves in a deliberate manner and therefore represent landscapes of graded refractive index (graded magnonic index). By analogy to the fields of graded-index photonics and transformation optics, the studies of spin waves in graded magnonic landscapes can be united under the umbrella of the graded-index magnonics theme and are reviewed here with focus on the challenges and opportunities ahead of this exciting research direction.

This research has received funding from the European Union's Horizon 2020 research and innovation program under Marie Sklodowska-Curie Grant Agreement No. 644348 (MagIC) and from Ukrainian State Fund for Fundamental Research under project No. F71/73-2016 ('Multifunctional Photonic Structures').

Background Automated external defibrillators (AEDs) operated by lay persons are used in the UK in a National Defibrillator Programme promoting public access defibrillation (PAD). Methods Two strategies are used: (1) Static AEDs installed permanently in busy public places operated by those working nearby. (2) Mobile AEDs operated by community first responders (CFRs) who travel to the casualty. Results One thousand five hundred and thirty resuscitation attempts. With static AEDs, return of spontaneous circulation (ROSC) was achieved in 170/437 (39%) patients, hospital discharge in 113/437 (26%). With mobile AEDs, ROSC was achieved in 110/1093 (10%), hospital discharge in 32 (2.9%) (P < 0.001 for both variables). More shocks were administered with static AEDS 347/437 (79%) than mobile AEDs 388/1093 (35.5%) P < 0.001. Highly significant advantages existed for witnessed arrests, administration of shocks, bystander CPR before arrival of AED and short delays to start CPR and attach AED. These factors were more common with static AEDs. For CFRs, patients at home did less well than those at other locations for ROSC (P < 0.001) and survival (P = .006). Patients at home were older, more arrests were unwitnessed, fewer shocks were given, delays to start CPR and attach electrodes were longer. Conclusions PAD is a highly effective strategy for patients with sudden cardiac arrest due to ventricular fibrillation who arrest in public places where AEDs are installed. Community responders who travel with an AED are less effective, but offer some prospect of resuscitation for many patients who would otherwise receive no treatment. Both strategies merit continuing development.

We have used time-resolved scanning Kerr microscopy (TRSKM) and micromagnetic simulations to demonstrate that, when driven by spatially uniform microwave field, the edges of patterned magnetic samples represent both efficient and highly tunable sources of propagating spin waves. The excitation is due to the local enhancement of the resonance frequency induced by the non-uniform dynamic demagnetizing field generated by precessing magnetization aligned with the edges. Our findings represent a crucial step forward in the design of nanoscale spin-wave sources for magnonic architectures, and are also highly relevant to the understanding and interpretation of magnetization dynamics driven by spatially-uniform magnetic fields in patterned magnetic samples.

Objective: To report on the effectiveness of an initiative to reduce deaths from sudden cardiac arrest occurring in busy public places. Setting: 110 such places identified from ambulance service data as high risk sites. Patients: 172 members of the public who developed cardiac arrest at these sites between April 2000 and March 2004. 20 592 defibrillator months’ use is reported, representing one automated external defibrillator (AED) use every 120 months. Intervention: 681 AEDs were installed; staff present at the sites were trained in basic life support and to use AEDs. Main outcome measures: Initial rhythm detected by AED, restoration of spontaneous circulation, survival to hospital discharge. Results: 172 cases of cardiac arrest were treated by trained lay staff working at the site before the arrival of the emergency services during the period. A shockable rhythm was detected in 135 (78%), shocks being administered in 134 an estimated 3–5 minutes after collapse; 38 (28.3%) patients subsequently survived to hospital discharge. Spontaneous circulation was restored in five additional patients who received shocks but died later in hospital. In 37 cases no shock was initially indicated; one patient survived after subsequent treatment by paramedics, cardiopulmonary resuscitation having been given soon after collapse. Overall, irrespective of the initial rhythm, 39 patients (22.7%), were discharged alive from hospital. For witnessed arrests of presumed cardiac cause in ventricular fibrillation (an international Utstein comparator) survival was 37 of 124 (29.8%). Conclusions: The use of AEDs by lay people at sites where cardiac arrest commonly occurs is an effective strategy to reduce deaths at these sites.

Ferromagnetic resonance in thin films and heterostructures is studied by micromagnetic simulation. Using a Fourier transform, we obtain the power spectrum of modes of precession and demonstrate that they agree with experimental results. Additional resonance modes associated with demagnetization effects are observed and studied as a function of the sample dimensions. Sufficiently confined geometries lead to a reorientation of the resonance mode, and a dramatic change in its frequency. Finally, the simulations are extended to exchange-coupled bilayers where energy is transferred between magnetic materials. © 2014 AIP Publishing LLC.

Lipoxygenase-mediated oxidation of fatty acids has long been implicated in the production of off-flavors in soybean products. This assumption was tested by use of preparations from soybean lines nearly isogenic to the cultivar Century that lack the lipoxygenase isozyme or isozyme combinations L1, L2, L3, L1 + L3, or L2 + L3. Near-isogenic lines were used to ensure that any effects observed were due to elimination of lipoxygenase isozymes, and not to other unrecognized genetic differences between lines. Full-fat soy flour and unblanched soymilk preparations from the lines were evaluated by a six-member taste panel for eight flavor and/or aroma attributes common to soybeans. By comparison to near-isogenic controls, removal of the L2 isozyme from soymilk preparations produced significantly lower scores for beany, rancid and oily flavor and aroma attributes, as well as higher scores for dairy and cereal flavor and aroma attributes. Similar trends were noted for soy flour flavor attributes. Thiobarbituric acid (TBA) numbers, a measure of lipid oxidation, were lower in homogenized soy flour suspensions from lines lacking L2. Removal of the L1 and L3 isozymes did not result in improved flavor scores or lower TBA numbers. Total oil content and the fatty acid profile of the near isolines did not vary appreciably. The results indicated that genetic removal of the L2 isozyme may reduce off-flavors in soy products.

A cultivar lacking the glycinin subunit A5A4B3 ('Raiden') was crossed with one lacking the α'-subunit of β-conglycinin ('Keburi'). Analysis of F2 and F3 progeny indicated that the missing bands of the A5A4B3 and the α'-subunit were each controlled by a recessive allele of two independently segregating genes. Gene symbols Gy 4/gy 4 and Cgy 1/cgy 1 were proposed for the genes which confer the presence or absence of the glycinin and conglycinin subunits, respectively.