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Stochastic self-similarity and self-affinity in the data on the solar activity phenomena is discussed in this paper. The following results are given and discussed. Firstly, the area–perimeter method was applied to obtain the fractal dimension values of solar spot umbras and of equal-intensity field lines in solar active regions (ARs). The fractal dimension value D 0=1.35±0.03 has been obtained for sunspot umbras. Field lines of equal intensity have different values of fractal dimensions for north and south polarities. Secondly, it is shown that the fractal dimension extracted from correlation between the magnetic flux and its cross-sectional area (i.e. a photosphere) is temporally invariant for an AR, but the fractal dimensions can be considerably different for various ARs. Thirdly, the multifractal nature of ARs magnetic fields was confirmed by a study of the scaling properties of their Renyi entropy. Fourthly, the R/S analysis was used for the Wolf series with purpose of estimating the long-time ‘memory...

Variability of EPR signal parameters in retrospective dosimetry with teeth has been studied among five different oblasts (regions) of Ukraine. It was found that the native signal in enamel is region-invariant and has peak-to-peak width of 0.85±0.01 mT and intensity of 1.0±0.20 normalized units. Low-frequency background signals in the spectra of enamel, 1 expressed in terms of dose were estimated to represent 15–20 mGy. Variability of radiation sensitivity among different teeth (inter-sample variability measured using 100 mg aliquots) was ±4% while among different parts of one tooth (intra-sample variability measured using 5–10 mg aliquots)—±7%.

We present here a particular application area for EPR dosimetry with teeth—use as a source of reference dose values for validation/verification of other retrospective dosimetry techniques and existing dose records. The conditions of application of EPR dosimetry in this role as well as practical design of such studies are shown. Particular attention is given to the requirements to the techniques in terms of precision and throughput, as well as to the issue of availability of samples for analysis and practical solution of this problem. Practical application of this approach is illustrated by several examples of completed validation sub-studies, which were performed in the framework of large-scale post-Chernobyl epidemiological studies.

We have determined the characteristic features of the formation of five-layer perovskites Ca5− x SrxTiNb4O17 (x=0−5) from systems of coprecipitated hydroxocarbonates. We have established that the sequence of formation for their crystal structure depends on the composition and nature of the products obtained, and is different for the individual compounds Ca5TiNb4O17, Sr5TiNb4O17, and the phases Ca5−x SrxTiNb4O17 (x=1−4).

The reversal of two-magnon relaxation associated with linear scattering of oscillations of uniform magnetization precession from sample nonuniformities is studied theoretically and experimentally in ferrite spheres of yttrium iron garnet (YIG). Relaxation reversal is performed by parametric phase conjugation of dipole-exchange spin waves formed as a result of scattering of uniform precession from inhomogeneities. As a result of two-magnon backward scattering of dipole-exchange spin waves with a certain time delay, magnetization oscillations are renewed with an amplitude that could exceed the initial amplitude of uniform precession. The relaxation reversal is due to crystallographic anisotropy of the sample and is manifested most strongly when a YIG sphere is magnetized along the intermediate axis [110]. Experiments were carried out on YIG spheres of diameter 0.65–1.05 mm for a parallel pumping frequency ωp/2π ≈ 9.4 GHz, which is about twice the uniform precession frequency. The maximal delay time for the restored signal of uniform precession was about 2 μs, while the maximal amplitude exceeded the initial uniform precession amplitude by a factor of about 5. The “latent” relaxation parameters of ferrites, e.g., the natural ferromagnetic resonance linewidth associated with many-particle processes and the linewidth associated with two-magnon scattering at bulk nonuniformities, are determined experimentally.

The matrix method of EPR spectra decomposition is developed and adapted for routine application in retrospective EPR dosimetry with teeth. According to this method, the initial EPR spectra are decomposed (using methods of matrix algebra) into several reference components (reference matrices) that are specific for each material. Proposed procedure has been tested on the example of tooth enamel. Reference spectra were a spectrum of an empty sample tube and three standard signals of enamel (two at g =2.0045, both for the native signal and one at g ⊥ =2.0018, g || =1.9973 for the dosimetric signal). Values of dosimetric signals obtained using the given method have been compared with data obtained by manual manipulation of spectra, and good coincidence was observed. This allows considering the proposed method as potent for application in routine EPR dosimetry.

In the paper the results of investigations on ten solar active regions are presented. The main results are as follows: firstly, the total down-flow velocity exceeds the up-flow velocity by about two orders of magnitude in all the active regions; secondly, no correlation was found between the mean integral velocity flux and the mean integral magnetic flux for all the active regions; thirdly, it was found that, besides a direct correlation between the total sunspot area and the total magnetic flux in active regions, occasionally there is an inverse correlation between these parameters, and the inverse correlation times often corresponded to the structural and topological rebuilding of magnetic flux in the active regions; fourthly, a good correlation was found between some parameters of integral fluxes (magnetic and velocity) and X-ray flux variations.

We present a study of the relationship between integral area and corresponding total magnetic flux for solar active regions. It is shown that some of these relationships are satisfied to simple power laws. Fractal examination showed that some of these power laws can not be justified inside the simple models of stationary magnetic flux tube aggregation. All magnetic fluxes and corresponding areas were calculated using the data measured with the Solar Magnetic Field Telescope of the Huairou Solar Observing Station in Beijing.

In this paper, several integral parameters of solar active regions are defined. The values of these parameters can be calculated from observational data. It is shown that only five of them are inde...

A method for evaluating the overall uncertainty of alanine EPR transfer dosimetry in the therapeutic dose range is described. The method uses experimental data on EPR signal reproducibility from replicate dosimeters irradiated to low doses (1–5 Gy), estimates of Type B uncertainties, and Monte Carlo simulations of heteroscedastic orthogonal linear regression. A Bruker ECS106 spectrometer and Bruker alanine dosimeters have been used for this evaluation. The results demonstrate that alanine dosimetry can be used for transfer dosimetry in that range with the overall uncertainty 1.5–4% (1σ) depending on the dose, the number of replicate dosimeters, and the duration of the calibration session (the session should not exceed one working day).

Magnons - the quanta of spin waves - propagating in magnetic materials with wavelengths at the nanometer-scale and carrying information in the form of an angular momentum, can be used as data carriers in next-generation, nano-sized low-loss information processing systems. In this respect, artificial magnetic materials with properties periodically varied in space, known as magnonic crystals, are especially promising for controlling and manipulating the magnon currents. In this article, different approaches for the realization of static, reconfigurable, and dynamic magnonic crystals are presented along with a variety of novel wave phenomena discovered in these crystals. Special attention is devoted to the utilization of magnonic crystals for processing of analog and digital information., Comment: 37 pages, 9 figures, 2 tables

An attractive direction in next-generation information processing is the development of systems employing particles or quasiparticles other than electrons—ideally with low dissipation—as information carriers. One such candidate is the magnon: the quasiparticle associated with the eigen-excitations of magnetic materials known as spin waves. The realization of single-chip all-magnon information systems demands the development of circuits in which magnon currents can be manipulated by magnons themselves. Using a magnonic crystal—an artificial magnetic material—to enhance nonlinear magnon–magnon interactions, we have succeeded in the realization of magnon-by-magnon control, and the development of a magnon transistor. We present a proof of concept three-terminal device fabricated from an electrically insulating magnetic material. We demonstrate that the density of magnons flowing from the transistor’s source to its drain can be decreased three orders of magnitude by the injection of magnons into the transistor’s gate., A disturbance in the local magnetic order can propagate across a material just like a wave. Chumak et al. now demonstrate a transistor operating on a single quantum of these so-called spin waves, known as a magnon, which could be a central element for magnetic-material-based information processing.

We present the temporal evolution of the longitudinal spin Seebeck effect in a YIG$|$Pt bilayer system. Our findings reveal that this effect is a submicrosecond fast phenomenon governed by the thermal-magnon diffusion along the thermal gradient inside the magnetic material. A comparison of experimental results with the thermal-driven magnon-diffusion model demonstrates that the temporal behavior of this effect depends on the time development of the temperature gradient in the magnetic material close to the interface. The effective thermal-magnon diffusion length for the YIG$|$Pt system is estimated to be around 500 nm.

Single phase Ba5KNb5O18 (I) is prepared by solid state reaction of Ba5Nb4O15 and KNbO3 (1370 K, 2 h), while Sr6Nb4SnO18 (II) results from calcination of the coprecipitated metal hydroxycarbonates (1570 K, 2 h).

Bose-Einstein condensation of quasi-particles such as excitons, polaritons, magnons and photons is a fascinating quantum mechanical phenomenon. Unlike the Bose-Einstein condensation of real particles (like atoms), these processes do not require low temperatures, since the high densities of low-energy quasi-particles needed for the condensate to form can be produced via external pumping. Here we demonstrate that such a pumping can create remarkably high effective temperatures in a narrow spectral region of the lowest energy states in a magnon gas, resulting in strikingly unexpected transitional dynamics of Bose-Einstein magnon condensate: the density of the condensate increases immediately after the external magnon flow is switched off and initially decreases if it is switched on again. This behaviour finds explanation in a nonlinear 'evaporative supercooling' mechanism that couples the low-energy magnons overheated by pumping with all the other thermal magnons, removing the excess heat, and allowing Bose-Einstein condensate formation.

The design of a microstructured, fully functional spin-wave majority gate is presented and studied using micromagnetic simulations. This all-magnon logic gate consists of three-input waveguides, a spin-wave combiner and an output waveguide. In order to ensure the functionality of the device, the output waveguide is designed to perform spin-wave mode selection. We demonstrate that the gate evaluates the majority of the input signals coded into the spin-wave phase. Moreover, the all-magnon data processing device is used to perform logic AND-, OR-, NAND- and NOR- operations., Comment: 5 pages, 5 figures

Low selectivity of action of the chemotherapeutic agents is one of their main shortcomings, leading to serious negative side effects in cancer patients. The main reason for this phenomenon is the formation of free radicals during the action of these drugs in both normal and tumor cells. Doxorubicin and cisplatin are among the most commonly used anticancer drugs. They realize the antineoplastic activity by the intercalation into DNA structure and production of the reactive oxygen species (ROS) (1-3). However, these drugs lead to severe cardio- and nephrotoxicity, which significantly limits their use for tumor treatment (4). It was shown that side effects of doxorubicin and cisplatin are mediated by hydroxyl radicals, which are formed in the presence of iron (II) from superoxide anions whose production is induced by these drugs (3,5). Numerous studies indicate that ROS-induced apoptosis of tumor cells takes place only under supraclinical doses of anthracyclines, and ROS production is not critical for realization of their anticancer activity (3). Thus, selective blocking of ROS action by specific antioxidant agents should at least partially reduce the toxicity of doxorubicin and cisplatin toward normal cells, without significant impact on the antitumor action of these drugs. Promising candidates for such role are derivatives of the pantothenic acid, since they possess significant antioxidant effect toward the mammalian cells and are able to protect the cells against toxic effects of free radicals (6). The inorganic and organic selenium derivatives (sodium selenite and selenomethionine) belong to another group of antioxidants that demonstrated a protective effect during cisplatin chemotherapy (7,8). Similar protective effects were also observed for the pantothenic acid (9). However, it remains unknown whether these antioxidants are capable of inhibiting the production of harmful ROS (including superoxide and hydroxyl radicals) due to the action of anticancer agents, and at the same time not interfering with the anti-tumor activity of these drugs. Besides, the effect of D-pantethine, selenomethionine, and sodium selenite used in combination with the anticancer drugs toward tumor cells resistant to chemotherapy has not been studied thoroughly (10). In this study, we aimed to develop new approaches for cancer chemotherapy that would eliminate negative side effects of the anticancer drugs caused by an excessive production of free radicals, which adversely affect normal tissues and organs in cancer patients. A chemotherapy regimen based on a combination of specific antioxidants (sodium selenite, selenomethionine, D-pantethine) and conventional anticancer drugs (doxorubicin, cisplatin), which are known to induce production of ROS, has been proposed. We studied the molecular mechanisms of antitumor activity of doxorubicin and cisplatin combined with the antioxidants toward tumor cell lines possessing different mechanisms of drug resistance. The results obtained in the in vitro study have been verified in experimental animals (rats).

Magnetism is a very fascinating and dynamic field. Especially in the last 30 years it has experienced many major advances in the full range from novel fundamental phenomena to new products. Applications such as hard disk drives and magnetic sensors are part of our daily life, and new applications, such as in non-volatile computer random access memory, are expected to surface shortly. Thus it is timely for describing the current status, and current and future challenges in the form of a Roadmap article. This 2014 Magnetism Roadmap provides a view on several selected, currently very active innovative developments. It consists of 12 sections, each written by an expert in the field and addressing a specific subject, with strong emphasize on future potential. This Roadmap cannot cover the entire field. We have selected several highly relevant areas without attempting to provide a full review - a future update will have room for more topics. The scope covers mostly nano-magnetic phenomena and applications, where surfaces and interfaces provide additional functionality. New developments in fundamental topics such as interacting nano-elements, novel magnon-based spintronics concepts, spin-orbit torques and spin-caloric phenomena are addressed. New materials, such as organic magnetic materials and permanent magnets are covered. New applications are presented such as nano-magnetic logic, non-local and domain-wall based devices, heat-assisted magnetic recording, magnetic random access memory, and applications in biotechnology. May the Roadmap serve as a guideline for future emerging research directions in modern magnetism., 37 pages

The effect of caries in EPR dosimetry of tooth enamel (in the dose range of 0–1 Gy) was investigated. The enamel of each tooth was divided into carious, non-carious and intermediate portions. The EPR signals of enamel at g = 2.0018 (dosimetric) and g = 2.0045 (native) were examined. The intensity of the dosimetric signal was the same for all three portions, while that of the native signal was higher for carious portions than for non-carious and intermediate portions. Reconstruction of the laboratory applied doses was done using all portions. Reasonable correlation between nominal and reconstructed doses was found in most cases. The effect of alkali treatment on the native and dosimetric signals of enamel was also tested. Reduction of the native signal intensity, particularly in the carious portions, was found to be the only significant effect. This resulted in a slight improvement in the accuracy of the reconstructed doses.

Eighteen international EPR laboratories participated in the second intercomparison programme. Each participant had to prepare enamel samples and evaluate the absorbed dose from molars that were irradiated in vitro in the range 0-1000 mGy. The objective of the programme was to bring together all methods which are currently applied by different laboratories for EPR dose reconstruction and to demonstrate the present state of dosimetry. An overview of the essential features of the different methods is presented. The current accuracy of EPR tooth enamel dosimetry under defined conditions of irradiation is evaluated. (C) 2000 Elsevier Science Ltd. All rights reserved.

Doses of few hundred liquidators were reconstructed using EPR dosimetric technique, developed and routinely used in SCRM. Both cumulative and accidental dose values were determined. Obtained results are analyzed and discussed.

An acute need for reliable dose estimates calls for development and implementation of high precision retrospective dosimetric techniques. Among others, maybe the most preferable approach is EPR dosimetry using tooth enamel as a natural lifetime dosemeter. During the past eight years a vast experience in the field of EPR dosimetry has been accumulated in SCRM. In this research, the main effort was put into providing the highest achievable accuracy and reproducibility of results as well as on reduction of labour intensity for the analyses. The technique developed in SCRM comprises sophisticated sample preparation procedures, analysis of EPR spectra using a Mn 2+ :MgO spectrometric standard, and individual calibration of dose response for each sample. Methods for taking into account confounding factors (e.g. medical X ray exposure, UV light effects and nonlinearity of dose-response curves) and assessment of overall uncertainty of dose estimation were also developed. A systematic approach to EPR dosimetry of an exposed population also includes efforts on acquisition of teeth from Chemobyl clean-up workers on a national scale. So far; samples from more than 700 individuals have been collected in Ukraine, and doses to more than 300 liquidators have been reconstructed. Application of this EPR dosimetric system allowed verification of Chemobyl dosimetry and provided on-going biomedical research with reliable retrospective dose estimates.

In der Spintronik wird anstelle der elektrischen Elementarladung die zweite elementare Eigenschaft der Elektronen – der Spin – zur Informationsverarbeitung genutzt. Durch die Kopplung der Spins untereinander kann sich eine sogenannte Spinwelle – auch Magnon genannt – im Material ausbreiten. Physikern der TU Kaiserslautern ist jungst erstmals die gezielte optische Manipulation der Spinwellen-Propagation gelungen.

A new method of long-term solar activity forecasting based on one-step extrapolation of the Walsh presentation of the Wolf numbers is used to predict the 23rd and 24th solar cycles.

The effect of the crushing and additive dose procedures used in EPR dosimetry of enamel was studied on the signals with g-factors of 2. 0045 and g, = 2.0018, g. = 1.9975. Eight fractions, ranging in size from

Exposure of tooth enamel to natural and artificial UV light results in stable EPR signals with g-factors of 1.9985, 2.0018, 2.0045, 2.0052 and 2.0110. The first three signals correspond to the parallel and perpendicular components of the radiation induced or dosimetric signal and the native signal reported in dosimetry and dating studies. The latter two signals were found to be sensitive to both gamma-ray and sunlight exposure, however, their responses to light differed from that to radiation, giving rise to the possibility of using them as indicators of the dose-equivalent resulting from light exposure.

An intercomparison of methods used for EPR dosimetry of enamel was made by the Center for Applied Dosimetry at the University of Utah and the Scientific Center for Radiation Medicine in the Ukraine (SCRM). The Utah group used the differential microwave power technique while the Ukrainian group employed a system of chemical preparation combined with a technique of subtraction of standard background signals. Because of time constraints, the results were reported before each laboratory had performed detailed background analyses. These results showed that both methods were in good agreement with the applied dose. Subsequent to this, the Utah group continued work on refining the differential power technique while SCRM investigated the differences between the inner and outer portions of the teeth. It was determined that the contribution of dental X-rays to the total dose was between 20 and 140 mGy.

to develop taking into account the specifity of exposure conditions a new algorithm for interventional cardiologists who use the X-ray protective clothes.modelling of the typical conditions of radiation exposure of interventional cardiologist wearing protective clothes during the interventions, providing Monte-Carlo computations of organ doses and dosimeters readouts.partial dose values for all possible radiation conditions and relative frequency weight coefficients for each condition were obtained by Monte-Carlo method.flexible and adaptive methodology for algorithm developing was proposed, a more specific algorithm was obtained for typical radiation conditions occuring under the interventional cardiology procedures. This algorithm well corresponded to experimental measurements demonstrating at that less conservatism comparing to other known algorithms.Meta doslidzhennja: rozrobyty novyj algorytm dlja intervencijnyh kardiologiv, shho pid chas operacij vykorystovujut' rentgeno-zahysnyj odjag, jakyj vrahovuvav by specyfichni umovy oprominennja v intervencijnij kardiologii'. Materialy ta metody doslidzhen': modeljuvannja typovyh umov oprominennja intervencijnogo kardiologa u zahysnomu odjazi pid chas operacii' ta vykonannja metodom Monte-Karlo komp'juternyh rozrahunkiv doz na organy ta pokazan' dozymetriv. Rezul'taty: rozrahovano metodom Monte-Karlo parcial'ni znachennja doz dlja vsih mozhlyvyh sytuacij oprominennja i vidnosni chastotni vagovi koeficijenty kozhnoi' sytuacii' oprominennja. Obchysleno efektyvni dozy ta porivnjano i'h z eksperymental'nymy. Vysnovky: rozrobleno gnuchku ta praktychnu metodologiju vyvedennja algorytmu j oderzhano algorytm, zastosovnyj dlja typovyh umov oprominennja medychnogo personalu pid chas provedennja intervencijnyh kardiologichnyh operacij. Bulo pokazano, shho oderzhanyj algorytm dobre uzgodzhujet'sja z rezul'tatamy eksperymental'nyh vymirjuvan' ta vidznachajet'sja menshoju konservatyvnistju porivnjano z inshymy algorytmamy.

Experimental testing of the practical application of methodology developed for the individual effective doses assay in an NPP staff by means of 4 dosimeters in case of non-uniform external γ-exposure with known angular characteristics of the radiation field.Two series of experimental phantom measurements were held at the workplaces of interventional cardiologists during a procedures in an X-ray operating room.Dose fields in a body of healthcare professional are characterized by the high gradients and readings of individual dosimeters depending on location can differ from 1.5 to 10 times. Thus a single dosimeter is not a source of sufficient information for accurate estimation of an effective dose. Studies have confirmed the possibility of NPP technique application at the workplace of interventional cardiologist. The essential need for a strict control of the eye lens doses is demonstrated.Metoju roboty bula eksperymental'na perevirka praktychnogo zastosuvannja rozroblenoi' dlja umov AES metodyky ocinky indyvidual'noi' efektyvnoi' dozy za pokazannjamy chotyr'oh dozymetriv v umovah neodnoridnogo zovnishn'ogo gamma-oprominennja z vidomymy kutovymy harakterystykamy polja vyprominjuvannja. Materialy ta metody doslidzhen': provedeno dvi serii' eksperymental'nyh fantomnyh doslidzhen' v umovah rentgen-operacijnoi' na robochyh miscjah likariv intervencijnoi' kardiologii' pid chas provedennja operacij. Rezul'taty ta vysnovky: pokazano, shho dozovi polja v tili medychnogo pracivnyka harakteryzujut'sja znachnymy gradijentamy, pokazannja indyvidual'nyh dozymetriv, zalezhno vid miscja roztashuvannja, mozhut' vidriznjatysja vid 1,5 do 10 raziv, otzhe, vykorystannja odnogo dozymetra ne daje dostatn'oi' informacii' dlja dostovirnoi' ocinky efektyvnoi' dozy. Doslidzhennja pidtverdyly mozhlyvist' zastosuvannja metodyky AES na robochomu misci intervencijnogo kardiologa. Prodemonstrovano neobhidnist' kontrolju doz na kryshtalyk oka.

Author(s): Little, Mark P; Azizova, Tamara V; Bazyka, Dimitry; Bouffler, Simon D; Cardis, Elisabeth; Chekin, Sergey; Chumak, Vadim V; Cucinotta, Francis A; de Vathaire, Florent; Hall, Per; Harrison, John D; Hildebrandt, Guido; Ivanov, Victor; Kashcheev, Valeriy V; Klymenko, Sergiy V; Laurent, Olivier; Ozasa, Kotaro; Tapio, Soile; Taylor, Andrew M; Tzoulaki, Ioanna; Vandoolaeghe, Wendy L; Wakeford, Richard; Zablotska, Lydia; Zhang, Wei; Lipshultz, Steven E

We investigate spin-wave propagation in a microstructured magnonic-crystal waveguide fabricated by localized ion implantation. The irradiation caused a periodic variation in the saturation magnetization along the waveguide. As a consequence, the spin-wave transmission spectrum exhibits a set of frequency bands, where spin-wave propagation is suppressed. A weak modification of the saturation magnetization by 7% is sufficient to decrease the spin-wave transmission in the band gaps by a factor of 10. These results evidence the applicability of localized ion implantation for the fabrication of efficient micron- and nano-sized magnonic crystals for magnon spintronic applications., Comment: 4 pages, 3 figures, submitted to Applied Physics Letters

We present an experimental study of spin-wave excitation and propagation in microstructured waveguides patterned from a 100 nm thick yttrium iron garnet (YIG)/platinum (Pt) bilayer. The life time of the spin waves is found to be more than an order of magnitude higher than in comparably sized metallic structures despite the fact that the Pt capping enhances the Gilbert damping. Utilizing microfocus Brillouin light scattering spectroscopy, we reveal the spin-wave mode structure for different excitation frequencies. An exponential spin-wave amplitude decay length of 31 {\mu}m is observed which is a significant step towards low damping, insulator based micro-magnonics.

We present a micromagnetic analysis of spin-wave propagation in a magnonic crystal realized as a permalloy spin-wave waveguide with a spatial periodical variation of its saturation magnetization. Frequency band gaps were clearly observed in the spin-wave transmission spectra and their origin is traced back to an overlap of individual band gaps of the fundamental and the higher order spin-wave width modes. The control of the depth, width and the position in frequency and space of the rejection band gaps by the width areas with a reduced magnetization and by the modulation level, are discussed in this study., Comment: 5 pages, 4 figures

An approach to the assessment of overall uncertainty of dose reconstruction by means of an ESR with additive dose technique is proposed. This approach takes account of uncertainties caused by different sources giving a quantitative measure of uncertainty of the determined dose. Dose is determined as an interval assessment rather than a deterministic value, allowing for the analytical estimation of both the mean value and the 95% confidence intervals. The effects of the number of additional irradiations and the value of dose increment on the uncertainty of dose determination are analyzed.

On the basis of observational data, we estimated the fractal dimension of the solar spot umbras is made. The estimation is obtained using the method of “cross-section area - outline length” and it is equal to 1.35 f 0.03. This value of the fractal dimension corresponds to turbulent structures of the “elastic sceletons” type. 1 METHOD There exist different methods for the evaluation of fractal dimensions of natural structures. One of them is an analysis of such ratios as surface-to-volume or crosssection area-to-outline length. This method has wide applications in various cases: for the study of laboratory turbulence, in the analysis of fractal structures of the storm clouds with strong convective fluxes, in the numerical simulation of clusters of correlated magnetic moments in the king model, and others (Proc. Sympos., 1986).

The thyroid doses of 49 360 inhabitants of Pripjat evacuated after the accident at Chernobyl were reconstructed. During their evacuation most of the evacuees passed through highly contaminated territories. The evaluation of a large-scale public survey showed that only about 50% of the evacuees had left the contaminated areas within 5 days and that 30% of them stayed there for more than 30 days. As a first step, the model of dose estimations was improved, and thyroid doses were assessed for the group of evacuees for whom the131I activity in the thyroids was measured. The131I incorporation during the first 5 days after the accident was described by a single-intake model (inhalation); later incorporations were assumed to be proportional to the radioiodine activity in milk. As a second step, the correlation between the calculated doses andindividual parameters (place of residence in Pripjat, intake of stable iodine, and age at the time of the accident) was described by an empirical equation. This equation was applied to all evacuees who completed the questionnaires of the public survey. Previous dose assessments were found to overestimate the thyroid doses especially for the younger evacuees. On the basis of these estimations, collective doses and the resulting radiation risks for thyroid cancer were assessed for different age groups.

An active nonlinear microwave signal processor based on the excitation and parametric interactions of short and slow dipole-exchange spin waves (DESW) propagating in ferrite (yttrium-iron garnet or YIG) films is proposed and realized. The short-wavelength DESW were excited as a result of scattering of an input long-wavelength dipolar spin wave pulse on defects and inhomogeneities in the YIG film. The best results were achieved in the YIG film sample of the thickness L=7.1 /spl mu/m, where we obtained signal delay time of T/sub d/= 2.6 /spl mu/s with insertion losses lower than 20 dB//spl mu/s.

We performed ferromagnetic resonance measurements of square arrays of noninteracting Permalloy circular dots for different orientations of external magnetic field with respect to the patterned film plane (\ensuremath{\theta}). Out-of-plane angular dependence of the main resonance peak was measured in the whole range of the field angles 0\ifmmode^\circ\else\textdegree\fi{} \ensuremath{\leqslant} \ensuremath{\theta} \ensuremath{\leqslant} 90\ifmmode^\circ\else\textdegree\fi{}. The main eigenmodespatial distribution is strongly nonuniform due to the dot nonellipsoidal shape. Nevertheless, for dots with small aspect ratio $b=L/R\ensuremath{\leqslant}0.1$ (where $R$ is dot radius and $L$ is dot thickness) Kittel's equation, assuming uniform dynamic magnetization (no pinning at the dot lateral edges), describes the peak position with high accuracy. Analytical calculations and micromagnetic simulations confirmed the gradual evolution of the main mode profile and a smooth transition from the strong to relatively weak pinning conditions with the change of external magnetic field angle.

The phenomenon of wave trapping in an artificial crystal with limited number of periods is demonstrated experimentally using spin waves in a magnonic crystal. The information stored in the crystal is recovered afterwards by parametric amplification of the trapped wave. The storage process is based on the excitation of standing internal crystal modes and differs principally from the well-known phenomenon of deceleration of light in photonic crystals., Comment: 4 pages, 4 figures

The potential to control the number of the spin-wave band gaps of a magnonic crystal (MC) by variation of its geometry is investigated by numerical simulations. The magnonic crystal is represented by a micro-sized planar ferromagnetic waveguide with periodically variable width. By choosing a step-like or sinusoidal variation of the width, the magnonic crystal reveals multiple or single band gaps, respectively. This allows for additional degrees of freedom in the design of MC based microwave filters and phase shifters with desired characteristics. The MCs band gaps have been studied in the space and frequency domains exploring the spin-wave spectrum dependence on the probing position inside the magnonic crystal., 8 pages, 3 figures

Background: Although high doses of ionizing radiation have long been linked to circulatory disease, evidence for an association at lower exposures remains controversial. However, recent analyses suggest excess relative risks at occupational exposure levels.Objectives: We performed a systematic review and meta-analysis to summarize information on circulatory disease risks associated with moderate- and low-level whole-body ionizing radiation exposures.Methods: We conducted PubMed/ISI Thomson searches of peer-reviewed papers published since 1990 using the terms "radiation" AND "heart" AND "disease," OR "radiation" AND "stroke," OR "radiation" AND "circulatory" AND "disease." Radiation exposures had to be whole-body, with a cumulative mean dose of < 0.5 Sv, or at a low dose rate (< 10 mSv/day). We estimated population risks of circulatory disease from low-level radiation exposure using excess relative risk estimates from this meta-analysis and current mortality rates for nine major developed countries.Results: Estimated excess population risks for all circulatory diseases combined ranged from 2.5%/Sv [95% confidence interval (CI): 0.8, 4.2] for France to 8.5%/Sv (95% CI: 4.0, 13.0) for Russia.Conclusions: Our review supports an association between circulatory disease mortality and low and moderate doses of ionizing radiation. Our analysis was limited by heterogeneity among studies (particularly for noncardiac end points), the possibility of uncontrolled confounding in some occupational groups by lifestyle factors, and higher dose groups (> 0.5 Sv) generally driving the observed trends. If confirmed, our findings suggest that overall radiation-related mortality is about twice that currently estimated based on estimates for cancer end points alone (which range from 4.2% to 5.6%/Sv for these populations).

We describe a general mechanism of controllable energy exchange between waves propagating in a dynamic artificial crystal. We show that if a spatial periodicity is temporarily imposed on the transmission properties of a wave-carrying medium whilst a wave is inside, this wave is coupled to a secondary counter-propagating wave and energy oscillates between the two. The oscillation frequency is determined by the width of the spectral band gap created by the periodicity and the frequency difference between the coupled waves. The effect is demonstrated with spin waves in a dynamic magnonic crystal., Comment: 5 pages, 4 figures

The influence of a thermal gradient on the propagation properties of externally excited dipolar spin waves in a magnetic insulator waveguide is investigated. It is shown that spin waves propagating towards a colder region along the magnetization direction continuously reduce their wavelength. The wavelength increase of a wave propagating into a hotter region was utilized to realize its decomposition in the partial waveguide modes which are reflected at different locations. This influence of temperature on spin-wave properties is mainly caused by a change in the saturation magnetization and yields promising opportunities for the manipulation of spin waves in spin-caloritronic applications., Comment: 4 pages, 4 figures

The current focus on networking and mutual assistance in the management of radiation accidents or incidents has demonstrated the importance of a joined-up approach in physical and biological dosimetry. To this end, the European Radiation Dosimetry Working Group 10 on 'Retrospective Dosimetry' has been set up by individuals from a wide range of disciplines across Europe. Here, established and emerging dosimetry methods are reviewed, which can be used immediately and retrospectively following external ionising radiation exposure. Endpoints and assays include dicentrics, translocations, premature chromosome condensation, micronuclei, somatic mutations, gene expression, electron paramagnetic resonance, thermoluminescence, optically stimulated luminescence, neutron activation, haematology, protein biomarkers and analytical dose reconstruction. Individual characteristics of these techniques, their limitations and potential for further development are reviewed, and their usefulness in specific exposure scenarios is discussed. Whilst no single technique fulfils the criteria of an ideal dosemeter, an integrated approach using multiple techniques tailored to the exposure scenario can cover most requirements. © The Author 2010. Published by Oxford University Press. All rights reserved.

We experimentally show that exchange magnons can be detected using a combination of spin pumping and inverse spin-Hall effect (iSHE) proving its wavelength integrating capability down to the sub-micrometer scale. The magnons were injected in a ferrimagnetic yttrium iron garnet film by parametric pumping and the iSHE-induced voltage was detected in an attached Pt layer. The role of the density, wavelength, and spatial localization of the magnons for the spin pumping efficiency is revealed. This study opens the field of the magnon-based information processing to magnons with nano-scale wavelengths.

Estimating the effective dose E with dosemeters calibrated in terms of the personal dose equivalent H(p)(10), one should take into account that the ratio of these two values, i.e. the conversion coefficient C(k), depends essentially on angular and energy parameters of the incident radiation field and is not always close to unity. Introducing the parameter that expresses the degree of anisotropy of the photon field, the paper proposes workplace categorisation and presents methods of workplace monitoring used for more accurate estimation of E at two operating nuclear power plants (NPPs) and Object Shelter in Ukraine.

Conversion of traveling magnons into an electron carried spin current is demonstrated in a time resolved experiment using a spatially separated inductive spin-wave source and an inverse spin Hall effect (ISHE) detector. A short spin-wave packet is excited in a yttrium-iron garnet (YIG) waveguide by a microwave signal and is detected at a distance of 3 mm by an attached Pt layer as a delayed ISHE voltage pulse. The delay in the detection appears due to the finite spin-wave group velocity and proves the magnon spin transport. The experiment suggests utilization of spin waves for the information transfer over macroscopic distances in spintronic devices and circuits., Comment: 3 pages, 4 figures