Further, differences in geometry, plasma flow conditions (or lack thereof), magnetic topologies, and field strengths between Gallimore’s Princeton Benchmark Thruster, Hoyt’s coaxial accelerator, Fos- ter’s quiescent plasma experiment, and Tahara’s thrusters can yield particularly different structure to the current streamlines and conduction in the near-anode region. Moreover, there is a conflict between competing suggestions from authors such as Gallimore and Hoyt (anode-intersecting B fields) and Tikhonov (anode-parallel B fields) for the prospects of using applied B fields to reduce anode falls but also avoid excessive current densities. Further, no details were made available about the current pattern or plasma properties of the promising Ageyev thruster design. Therefore, our re- search sought to understand the plasma discharge current pattern and conduction in the near-anode region of an MPDT. Our work specifically examines the effect of appliedmagneticfields on the current distribution along the anode and current structure within the discharge as part of an inves- tigation into the potential for reducing anode fall voltages and mitigating onset-related behaviors with the appliedmagneticfields.
values (Additional file 1: Figure S4), for both type of IOMNPs for all appliedmagneticfields, drastically de- crease, indicating that the Brownian contribution is sup- pressed: the SAR values increase with the appliedmagnetic field amplitude reaching 600 W/g at 60 kA/m (355 kHz), where the highest hysteresis area is covered. A progressive decrease of SAR values is recorded when the viscosity is increased by dissolving the IOMNPs in PEG1000 (Additional file 1: Figure S4). Since the PEG1000 at room temperature is solid, the Brownian contribution is totally suppressed and the magnetic an- isotropy losses contribute to the power dissipation. Therefore, one can consider that Brownian relaxation is the main mechanism responsible for the high SAR values obtained in water for both type of IOMNPs. The dipole-dipole attractive interactions induce aggrega- tion of IOMNPs. As depicted in the Additional file 1: Figure S7 in DLS measurements, the IOMNPs exhibit different degrees of aggregation. At a concentration of 0.5 mg/ml, cubic IOMNPs form aggregates with hydro- dynamic diameters between 450 and 620 nm, while poly- hedral IOMNPs of smaller size develop aggregates with bigger hydrodynamic diameters (700–850 nm). It can be observed that the SAR values of IOMNPs increase with the hydrodynamic diameter of IOMNP aggregates (Additional file 1: Figure S7). This observation is consistent with the above presented results proving that Brown relax- ation is the main mechanism for heat generation in large IOMNPs at high magnetic field intensities.
same order of magnitude as the anisotropy energy. Dipole–dipole interactions in the iron oxide film are verified by probing the temperature-dependent magnetiza- tion for orthogonally appliedmagneticfields. Figure 5 illustrates the ZFC/FC magnetization for magneticfieldsapplied parallel and perpendicular to the film surface. ZFC measurements are obtained by cooling the sample to 20 K in zero field. A small field is then applied at 20 K, and the magnetization is recorded as the sample warms to 350 K. The procedure for the FC measurement is similar, except the sample is cooled in the presence of a small external field. For the ZFC data, the magnetic moment rises more rapidly and attains a greater maximum value for the field applied parallel to the film surface. This implies an easy magnetization axis in the plane of the film as opposed to perpendicular to the surface. Hence, a significant magne- tization anisotropy due to the geometry of the film exists that can be approximated by E 1
To get more insight about magnetic field effects, Figure 3(b) illustrates counter plot of refractive index for continues variations of external field. It is obvious that central frequency has down shift with reduction of magnetic field. In addition to refractive index, slow down factor curve changes with applying an external field. Figure 3(c) exhibits SDF for different amounts of magnetic field. As it can be seen in Figure 3(c), the peak value of SDF is constant during increment of magnetic field and just the focal frequency of the device changes. Figure 3(d) displays better view of slow down factor alterations as a function of magnetic field. As observed in this curve, the focal frequency of device rises from 371.3THz to 372.4THz when value of magnetic field increases in range of 6T. In other words, by applying magnetic field in this range, the central frequency of device shifts near 1.1THz in comparison with experimental result that has been explained in .
low voltages and decreases with increase applied bias. However, no oscillations of CPD were observed with applied bias voltage for RTDs with QDs. The voltage dependence of CPD for InAs QDs was previously associated to the formation of excitonic complexes around hole and electron resonant tunneling condition. In our case, there is no evidence of formation of excitonic complexes with applied voltage in RTDs with QRs. These oscillations of PL intensity and polarization degree were associated to resonant tunneling to excited states of QRs in agreement of a previous work carried out on this device 23 .
The Cosic Resonance Recognition Model (RRM) for amino acid sequences was applied to the classes of proteins displayed by four strains (Sudan, Zaire, Reston, Ivory Coast) of Ebola virus that produced either high or minimal numbers of human fatalities. The results clearly differentiated highly lethal and non-lethal strains. Solutions for the two lethal strains exhibited near ultraviolet (~230 nm) photon values while the two asymptomatic forms displayed near infrared (~1000 nm) values. Cross-correlations of spectral densities of the RRM values of the different classes of pro- teins associated with the genome of the viruses supported this dichotomy. The strongest coeffi- cient occurred only between Sudan-Zaire strains but not for any of the other pairs of strains for sGP, the small glycoprotein that intercalated with the plasma cell membrane to promote insertion of viral contents into cellular space. A surprising, statistically significant cross-spectral correlation occurred between the “spike” glycoprotein component (GP1) of the virus that associated the anc- horing of the virus to the mammalian cell plasma membrane and the Schumann resonance of the earth whose intensities were determined by the incidence of equatorial thunderstorms. Previous applications of the RRM to shifting photon wavelengths emitted by melanoma cells adapting to reduced ambient temperature have validated Cosic’s model and have demonstrated very narrow- wave-length (about 10 nm) specificity. One possible ancillary and non-invasive treatment of people within which the fatal Ebola strains are residing would be whole body application of nar- row band near-infrared light pulsed as specific physiologically-patterned sequences with suffi- cient radiant flux density to perfuse the entire body volume.
Magnetic structures shows interesting properties when the their dimensions go down to nanoscale. They could be one, two or even three dimensional structures. For example, they can be thin film, wire, dot or even three dimensional structures. Understanding of high frequency properties of magnetic materials open up new route for the devices which work in nanosecond time scale. Different magnetic structures have been considered in this thesis to expore and explain both static and dynamic properties. The multilayer systems of ferromagnetic and antiferromagnetic were prepared to study the exchange bias phenomenon. Set of samples where the thickness of ferromgnetic layer was varied keeping the thickness of the antiferromagnetic layer constant to explain the thickness dependence exchange bias. Different experimental techniques were implemented to evaluate the both static and dynamic properties. The slight discrepancies on the exchange bias values that were evaluated using different techniques have been explained considering roughness of the surface, domain wall behaviour as well the reversible and irreversible process in magnetization switching. To better understand experimental results, the angular variation of both FORC and FMR were performed. The modified theroritical model of domain wall formation was used to explain the experimental results and good aggreement was achieved between experimental results and theoretical results.
without a broadening or temperature dependencies. As the E4 instrument detects all the scattered neutrons irrespective of their energy, this observation suggests that some portion of detected neutrons at this reciprocal space position undergoes quasielastic scattering process. This is documented in the inset of Fig. 13, which shows the constant-Q energy scan at the ( 1 2 1 2 1 2 ) position at 1.7 K and at 21 K recorded using the E1 spectrometer. It is apparent that the signal seen at the lower temperature is present within the whole energy window of the E1 spectrometer. (The signal detected at 21 K is due to the elastic background.) Nuclear Bragg reflections, on the other hand, are much narrower in the energy. This suggests that the magnetic signal is quasielastic in nature and extends most probably to higher energies. This intensity, not detected in the temperature dependence as measured at E1, is however collected on E4, thus causing the difference in the temperature dependences seen using the two instruments.
Introduction: Despite many studies on cell division, formation and treatment of cancer (Ca), there is not full explication of aging and death of cells. Everything in the Earth’s magnetic field (EMF) has paramagnetic and ferromagnetic characteristics. Hence tissue cells and organs have magnetic characteristics (Mc). This paper shows that EMF is a factor that impacts cell division. Anomalous magneticfields (AMF) and unnatural EMF contribute to continuous cell division that causes cancer. Moreover, it shows that the magnetic characteristic of the nuclei, organelles and substances is tightly related to the metabolism of the cells. The article also explains when the immune system works the best, why it fails in preventing the formation of cancerous cells, and how aging reduces the defense of the organism against intruders. Results: EMF influences all parts of the cells magnetic characteristics, which in turn impact metabolism. The sequences of the nucleotides in the construction of DNA and RNA match only by magnetic code. EMF impacts the process of crossing over which causes polymorphism and contributes to the evolution. A factor that stimulates cell division is EMF which boosts the metabolism and the immune system. All manifestations of aging are clearly explained by magnetic properties of cells. Intermolecular magnetic forces (Mf) in cell vary because they depend on the number of divisions and temperature. With each division, telomeres lose 100-200 nucleotides which reduces the nucleus Mf and metabolism in the cells. The immune system weakens, because of the impact of Mf. Conclusion: Natural EMF is a factor that influences cell division. Magnetic
Methods: Three finite element head models constructed from segmented MR images of an adult male subject were used for this study. These models were: (1) Model 1: full model with eleven tissues that included detailed structure of the scalp, hard and soft skull bone, CSF, gray and white matter and other prominent tissues, (2) the Model 2 was derived from the Model 1 in which the conductivity of gray matter was set equal to the white matter, i.e., a ten tissuetype model, (3) the Model 3 consisted of scalp, hard skull bone, CSF, gray and white matter, i.e., a five tissue-type model. The lead fields and MEGs due to dipolar sources in the motor cortex were computed for all three models. The dipolar sources were oriented normal to the cortical surface and had a dipole moment of 100 μ A meter. The inverse source localizations were performed with an exhaustive search pattern in the motor cortex area. A set of 100 trial inverse runs was made covering the 3 cm cube motor cortex area in a random fashion. The Model 1 was used as a reference model.
external H is shown in Figure 3. With the decrease of H, the phase transition curve splits into two lines for H < 4 T: one of them corresponds to the FM to PM phase transition, which occurs on heating, while the other corresponds to the inverse transition from PM to FM phase that occurs on cooling. In between the region, the magnetic state of the system is determined by the way through which the sample arrives at this region, i.e., by the increase or decrease of temperature. This confirms that the system has a critical end-point (H cr ≈ 4 T, T cr ≈ 160 K) at which first-order FM
prepared by floating zone technique 5 . The quality of the crystals were carefully checked by various techniques such as x-ray diffraction, Laue diffraction, ac susceptibility, etc. The magnetization measurements were done in a superconducting quantum interference device magnetometer in fields up to 7 T and in a vibrating sample magnetometer up to 11.5. Resistivity measurements were performed by a conventional four-probe method. Specific-heat measurements were performed using semiadiabatic techniques in a wide range of temperature (5–300 K) and magnetic field (0–10 T). Thermoelectric power measurements were carried out by a differential technique.
The study results show the electromagnetic behaviour of the magnetic nanoparticles in the magnetic field. The purpose of the study was to increase the force density as well as the magnetic field gradient to maximum possible higher limits. The maximum distance was 11cm distance where a force/weight ratio of about 300 at 11cm length was achieved in the X-axis. This can be used for therapeutic purposes. The magnetic nanoparticles can be injected in the retrosternal space in a line; and the movement of the magnetic nanoparticles can be controlled with external magnetic field to the target arteries which could be left internal mammary artery (LIMA) adjacent to left anterior descending artery (i.e., LIMA to LAD grafting). The neighbouring arteries to the coronaries can also be utilized as a potential target. However, this needs to be evaluated in future experimental studies for further validation and observations. The motion of the magnetic nanoparticles were already demonstrated from the surface, and the motion of the magnetic nanoparticles were studied in detail including the Brownian motion of the surrounding fluid and dipole-dipole interaction of the particles among themselves have some effect on the trajectory, however, this change in the trajectory is minimal 15,16 .
Large-scale, ordered magneticfields have been invoked to explain the launching, acceleration, and collimation of relativistic jets from the central nuclear region of an active galaxy , and from coalescing and merging stars (neutron stars and blackholes), e.g., . The magnetic field structure and particle composition of the jets are still not well constrained observationally. Circular polarization (CP; measured as Stokes parameter V) in the radio continuum emission from AGN jets provides a powerful diagnostic for deducing magnetic structure and particle composition because, unlike linear polarization (LP), CP is expected to remain almost completely unmodified by external screens, e.g., .
is the energy spectrum of charged particles in a constant magnetic field, f stands for fermion, β is the inverse of the temperature, l = ν + 1/2 + s/2 is the Landau level quantum number. ν = 0, 1, 2, . . ., and s = ±1. The s values correspond to the projection of the spin operator eigenvalues along the direction of the magnetic field.
The toroidal component of stellar magneticfields contains the free energy that, once liberated, is responsible for energetic events. Flares, coronal mass ejections and space weather in general have a large influence on the stellar environment, and can affect any plan- ets orbiting the star (Zarka 2007; Grießmeier, Zarka & Spreeuw 2007; Llama et al. 2011; Vidotto et al. 2012, 2013, 2015; See et al. 2014, 2015; Cohen et al. 2015). Presently, the toroidal compo- nent of stellar magneticfields has only been studied in single, or small samples, of stars. Petit et al. (2008) studied a sample of four solar-like stars and noted that the stellar rotation period plays an important role in determining the fraction of magnetic energy in the toroidal component of the stellar field. However, the rotation period cannot be the sole parameter that determines the toroidal en- ergy fraction since stars with similar rotation periods show different toroidal energy fractions. Additionally, observations of individual stars, over multiple epochs, show that the toroidal energy frac- tion can change significantly on the time-scale of years (Donati & Collier Cameron 1997; Donati et al. 1999, 2003b; Petit et al. 2009; Fares et al. 2010, 2013; Morgenthaler et al. 2012; Jeffers et al. 2014; Boro Saikia et al. 2015). This indicates that the dynamo is dy- namic in nature and cannot be characterized by single time averaged parameters.
direction along which the field changes. The instability generates helical waves whose wavenumber is parallel to the direction of the field. The configuration that leads to the most rapid growth of the instability corre- sponds to a field that varies at a similar scale as the electron number density. Such condi- tions are realized when the magnetic field contains a strong azimuthal component. Indeed, the direction of such a field is per- pendicular to the radius of the star, while the gradient of the electron number density is parallel to the radius. Thus, at the same time as the field migrates towards the poles, it also generates non-axisymmetric features. What determines the end point of this evo- lution is the ratio of initial poloidal versus toroidal field. Having 50% of the energy in the toroidal field would only lead to some minor displacement from the equator, with a stronger field in a zone at mid and lower latitudes. Magneticfields containing more energy in the toroidal component (90% and 99%) will push the field closer to the poles and generate more non-axisymmetric structure. In the initial transitional phase, the density-shearing instability becomes activated, generating zones of incoming and outgoing magnetic field. If the initial toroi- dal field contains 90% of the total energy, the field will generate a region around the poles where the strength of the field is about an order of magnitude higher than the
While the full suite of mass-loss rates described by Hurley, Pols & Tout (2000) was used it was found that, in order to generate su ffi cient low-mass WDs, it was necessary to take η = 1.0 for Reimers’ mass-loss parameter so that value was used throughout the work. Alternatively, su ffi cient low-mass WDs were found to be formed with smaller η if the Galactic disc were somewhat older. Meng et al. (2008) produce them with η = 0.25 in populations of 12 Gyr in age. However, the recent work of Kilic et al. (2017) has convincingly shown that the age of the Galactic disc cannot be greater than 10 Gyr. The metallicity was taken to be solar (Z = 0.02) in all the calculations. From all evolved systems those that could generate single HFMWDs were selected. To this end all pairs of WDs that merge outside any CE and leave a single WD remnant were extracted. These are the double degenerate (DD) WD WD mergers. Added to these are WD remnants of systems that underwent at least one CE phase and merged dur- ing the last CE phase and satisfy two further criteria. Firstly, either one or both of the stars must have a degenerate core before merging and secondly, there must be no further core burning before the remnant WD is exposed. It was assumed that such a core burning would be convective and destroy any frozen-in high magnetic field. The e ff ective number of actual binary systems was calculated by assuming that the primary stars are distributed according to Salpeter’s IMF (Initial Mass Function, Salpeter, 1955) N(M) dM ∝ M −2.35 dM, where N(M) dM is the number of stars with masses between M and M + dM, and that the secondary stars follow a flat mass ratio distribution for q ≤ 1, e.g. Ferrario (2012). Each binary system was then evolved with BSE from ZAMS to an age of 9.5 GYr (assumed age of the Galactic disk, e.g. Oswalt et al. (1996); Liu & Chaboyer (2000); Kilic et al. (2017). All binary systems in both populations, i.e. those becoming HFMWDs and those that do not, were given a weighting according to the Salpeter IMF. It was then possible to calculate the incidence of HFMWDs in the total WD population once the populations had been time integrated through to the Galactic disk age. The output from BSE for each binary system consisted of a time table of evolution through various stellar types (See table 2.1: “Stellar types distin- guished within the BSE algorithms”). By interrogating the output timetable for each system which became a HFMWD it was possible to extract the percentages of stellar companion types immediately preceding the last CE event in which the stellar merger giving rise to the high magnetic field occurred or alternatively which systems gave a DD merger post-CE. Similarly, it was possible to distinguish the WD types emerging from the CE.
The compressibility of the propagating wave front is not homogeneous and is sensitive to the nature of the background field. For example, it is associated with greater density varia- tion in regions of greater field complexity. Therefore, it is plau- sible that observations of the weak plasma compression as a similar wave propagates through coronal field will indicate the complexity of the background Alfvén speed and / or the nature of magnetic field lines. As such synthetic observables derived from the models presented within this article are expected to contain information about the initial conditions. It remains to be seen whether any seismological techniques can be employed on the wave dynamics to infer properties of the background medium. If so, observations of propagating transverse coronal waves may be used to infer the complexity of the coronal magnetic field.
large toroidal energy fractions but lower mass stars cannot. Though the two panels show essentially the same information, this break in behaviour at 0.5 M is much clearer in the bottom panel. A num- ber of authors have previously discussed a sudden change in the magnetic properties of M dwarfs at roughly 0.5 M (Donati et al. 2008b; Morin et al. 2008b, 2010; Gregory et al. 2012). They note that this break is roughly coincident with the fully convective limit suggesting a link with the change in internal structure. Dividing our sample on this basis, we find power index values of a = 0.72 ± 0.08 and a = 1.25 ± 0.06 for stars less and more massive than 0.5 M , respectively. These power laws are plotted in the top panel with dashed lines. It is worth noting that, among the M < 0.5 M stars, it is the dipole dominate stars that deviate the most from the higher index power law. The non-dipolar stars in the bistable regime, as discussed by Morin et al. (2010), are roughly compatible with the other power law. Additionally, theoretical models predict that these non-dipolar stars can vary cyclically and are able to generate sig- nificant toroidal fields (e.g. Gastine et al. 2013).