A study of the dynamics of magnetic disaccommodation in amorphous ferromagnets. I. Experimental results

Systematic room‐temperature measurements of the aftereffect of the ac magnetic permeability have been performed on a Fe81B13.5 Si3.5C2 amorphous ribbon in order to get detailed information about the nature of the atomic ordering processes responsible for the magnetic relaxation. The magnetic aftereffect related to 180° domain‐wall motion has been measured by means of a specific technique allowing periodic domain‐wall displacements to be induced between two fixed, neighboring equilibrium positions by applying a square‐wave field of proper amplitude and frequency. In this way, the average direction of the magnetization vector is cyclically modified in all points where the studied directional ordering processes may occur. As a consequence, the kinetics of ordering is modified in a characteristic way, giving rise to relevant variations in the intensity of the magnetic aftereffect measured between fixed times (t1=2×10−3 s and t2=10−1 s), and in the value of the magnetic induction at the time t2. All measurements have been performed at constant applied field. The degree of reliability of this experimental technique has been analyzed in detail. The magnetic aftereffect, ΔB=B(t1)−B(t2), and the magnetic induction B(t2) have been measured as functions of the number of domain‐wall cycles, and after removing the square‐wave field for a variable time t∗. The results of many independent measurements are reported and discussed

A study of the dynamics of magnetic disaccommodation in amorphous ferromagnets. II. Theoretical considerations

The results obtained in part I are interpreted in terms of the viscosity field arising from independent processes of directional ordering for magnetic defects dispersed in the amorphous structure and interacting with the magnetization vector. A specific model is developed in order to take into account the changes in the ordering kinetics induced by the periodic magnetization rotations described in part I. This model, however, requires that the magnetic induction remain constant during the whole measurement; as a consequence, the model's predictions cannot be directly compared with the experimental results, obtained instead at constant applied field. This difficulty is overcome by deriving a general relationship between the magnetic‐induction decay and the viscosity field kinetics for an arbitrary number of half‐periods of the square‐wave field. The agreement of our theory with the experimental results turns out to be quite satisfactory. As consequence, the ordering processes responsible for the magnetic aftereffect in amorphous ferromagnets may be described as essentially uncorrelated

Knowledge and Attitudes of Mothers on Neonatal Jaundice in Saravan, Iran

The objective of the study was to assess the knowledge and attitudes of mothers in Saravan, Iran on neonatal jaundice, whether or not herbal remedies were being used, and if these herbal remedies were harming the neonates. 59 participants answered questions from a questionnaire delivered orally and answers were recorded and entered into a spreadsheet for analysis. 72.88% of the neonates of the mothers questioned had neonatal jaundice within the first 28 days of birth. 58.67% of mothers knew that neonatal jaundice was a “sign of serious illness” and “could damage the brain.” 97.73% of neonates with jaundice within the first 28 days survived and 97.67% of the surviving babies had no abnormalities. 77.5% of mothers had given their neonate with jaundice “antibiotics,” “remedies,” or “herbs.” We concluded that the rates of jaundice among neonates were abnormally high in this region and that the mothers’ knowledge on the significance of the illness was appropriate. Although most of the mothers were giving their neonates herbal remedies, these remedies did not seem to be harming the neonates. Further research will be done to determine correlations and further conclusions

Short-time dynamics of correlated magnetic moments in superparamagnetic Cu-Co melt spun alloys exhibiting giant magnetoresistance

Evidence for correlation among superparamagnetic particles in melt-spun Cu100-xCox systems (x = 5-20) exhibiting a giant magnetoresistance is obtained by plotting this quantity as a function of reduced magnetization. Two ranges, R-theta(H-e) and R-theta(H-e), have been recently introduced to describe the extent of correlation among angles of tilt (theta) and of twist (phi) of superparamagnetic moments precessing around a local field axis. The angle of tilt appears to be spatially correlated over a distance larger by a factor of 3 than the angle of twist. This difference is explained by analyzing the short-time dynamics of magnetic moments in superparamagnetic granular systems with long-range interactions (of dipolar and the RKKY-like type). The typical time constants characterizing the process of scattering of conduction electrons by adjacent magnetic moments (electronic time of flight, relaxation times for theta and phi) are discussed in detail. An explicit expression for R-phi(H) is obtained by considering the competition between a magnetic interaction favoring parallel (or antiparallel) alignment or adjacent moments, and thermal disturbances resulting in a continuous loss of the phase coherence. (C) 1997 American Institute of Physics

TRADHISI NGALAP BERKAH ING PASAREYAN MBAH TRUNOJOYO DESA SENDANGHARJO, KECAMATAN NGASEM, KABUPATEN BOJONEGORO (TINTINGAN FOKLOR)

Abstrak Salah sawijine kabudayan Jawa yaiku tradhisi ngalap berkah ing pasareyane Mbah Trunojoyo. Panliti milih kasebut amarga tradhisi ngalap berkah lumaku ing desa kang kagolong mencil ing Bojonegoro. Pangarep panliti ngenalake marang masayrakat Jawa liyane lan ngangkat ekonomi warga. Saliyane iku paedah akademis kanggo nambahi wawasan lan bisa nambahi referensi kanggo panliten saemper kang ana ing dhaerah liya.Metodhe panliten sing digunakake dheskriptif kualitatif kanthi objek tradhisi ngalap berkah kang manggon ing Desa Sendangharjo, Ngasem, Bojonegoro. Asil saka panliten iki yaiku tradhisi ngalap berkah isih dilaksanakake nalika rame dina Jumat Paing. Tradhisi ngalap berkah iki tuwuh amarga wujud kapitayane masyarakat tumrap kaluwihan sing diduweni dening Mbah Trunojoyo. Tata laku tradhisi iki kanthi runtut lan migunakake ubarampe kembang setaman, menyan, lan berkat. Simbol lan makna yaiku ana ing saperangan tata laku. Fungsi sajrone tradhisi yaiku sistem proyeksi, pengesah budaya, sarana pendhidhikan lan piranti pengendhali sosial, fungsi ekonomi, fungsi sodaqoh, lan fungsi nguri-nguri kabudayan. Owah-owahan tradhisi ngalap berkah piranti ubarampe, berkatan, tata cara ndonga. Tembung Wigati : Tradhisi, Ngalap Berkah, Foklor

Magnetic Nanoparticle Imaging: Insight on the Effects of Magnetic Interactions and Hysteresis of Tracers

The dynamic properties of magnetite nanoparticles are investigated by rate equations with the aim of clarifying the factors affecting their performance as tracers in magnetic particle imaging (MPI). It is shown that size-dependent effects such as magnetic hysteresis and dipole-dipole interaction may have a great impact on the behavior of MPI tracers. Usually, magnetic imaging exploits the higher-order harmonics of the magnetization waveform without considering either intraparticle hysteresis or interparticle interactions. These assumptions may result in an incorrect estimate (either by excess or by defect) of the nanoparticle concentration, which is the ultimate aim of MPI. The mismatch between real and estimated values is apparent for concentrations typical of some therapeutic applications of magnetic nanoparticles or reached by effect of particle accumulation in organs because of slow clearance processes. We show that this difficulty can be removed by measuring not only the magnitude of the third harmonic of the signal but also the phase shift with respect to the driving field. The proposed technique of signal adjustment makes use of the settings of present-day MPI operating devices. The validity of the adjustment procedure is checked by a proof of concept using nonuniform nanoparticle concentrations

Threats to Ocean Biodiversity

Overfishing Taking fish out of the ocean faster than their populations can be naturally replenishedhttps://digitalcommons.imsa.edu/unsdg_infographics/1004/thumbnail.jp

L'évaluation développementale : Six façons de mettre la recherche en éducation au service de l'innovation

In March 2020, COVID-19 challenged health and educational systems across the country. The rapid reallocation of resources to ensure public safety had taken priority over educational obligations. Healthcare students were removed from clinical environments as their learning came to a grinding halt. While academic institutions were pivoting and transforming teaching and learning experiences, students responded to the pandemic with innovation, attending to gaps in patient care. As educators, we must understand how we can further support students and faculty to unleash innovative thinking during a crisis. To begin to address this educational need, academic institutions now have an opportunity to broaden the practice of education scholarship in accordance with best practices to nurture innovation and innovative thinking. What framework can aid us in this endeavor? In times of instability, Developmental Evaluation is an approach that can support the implementation of innovations within medical education. Using an example of an innovation in medical education, we offer six practical tips to begin to use Developmental Evaluation to support and enable learners and faculty in the creation of innovations and contribute to a broader definition of education scholarship.En mars 2020, la COVID-19 a bouleversé les systèmes de santé et d’éducation de tout le pays. La réaffectation rapide des ressources pour assurer la sécurité du public avait pris le pas sur les obligations éducatives. Les étudiants en santé ont été retirés des environnements cliniques et leur apprentissage a connu un arrêt net. Les établissements universitaires ont introduit des ajustements qui ont transformé les expériences d’enseignement et d’apprentissage. De leur côté, réagissant à la pandémie de manière innovante, les étudiants sont intervenus pour combler les besoins en soins aux patients. Il serait pertinent pour nous, éducateurs, de trouver les façons de mieux aider les étudiants et le corps enseignant à laisser libre cours à leur originalité dans les situations de crise. En vue de répondre à ce besoin éducatif, les établissements universitaires ont l’occasion d’aligner la recherche en éducation sur les meilleures pratiques pour favoriser l’innovation et la pensée novatrice. Quel cadre adopter pour nous aider dans cette entreprise? L’évaluation évolutive fait partie des approches qui peuvent soutenir la mise en œuvre d’innovations dans l’éducation médicale en période d’instabilité. À l’aide d’un exemple d’innovation dans le domaine, nous proposons six conseils pratiques pour faire de l’évaluation évolutive un facilitateur de l’innovation par les apprenants et les enseignants et un levier pour élargir la portée de la recherche en éducation

Dipolar interactions among magnetite nanoparticles for magnetic hyperthermia: a rate-equation approach

Rate equations are used to study the dynamic magnetic properties of interacting magnetite nanoparticles viewed as double well systems (DWS) subjected to a driving field in the radio-frequency range. Dipole-dipole interaction among particles is modeled by inserting an ad-hoc term in the energy barrier to simulate the dependence of the interaction on both the interparticle distance and degree of dipole collinearity. The effective magnetic power released by an assembly of interacting nanoparticles dispersed in a diamagnetic host is shown to be a complex function of nanoparticle diameter, mean particle interdistance and frequency. Dipolar interaction markedly modifies the way a host material is heated by an assembly of embedded nanoparticles in magnetic hyperthermia treatments. Nanoparticle fraction and strength of the interaction can dramatically influence the amplitude and shape of the heating curves of the host material; the heating ability of interacting nanoparticles is shown to be either improved or reduced by their concentration in the host material. A frequency-dependent cut-off length of dipolar interactions is determined and explained. Particle polydispersity entailing a distribution of particle sizes brings about non-trivial effects on the heating curves depending on the strength of dipolar interaction