Abstract The lattice parameters of the hexagonal unit cell, atomic parameters, and shift Raman active vibrations are measured p‐Bi 2 Te 3 under uniaxial hydrostatic pressure. structural investigations performed by neutron diffraction, studied scattering. results diffraction experiments constitute a direct experimental confirmation weak bonding between sandwiches in this narrow gap semiconductor with sandwich structure. As consequence, some phonon modes show rather strong dependence upon...

Most 3-D magnetic particle imaging (MPI) scanners currently use permanent magnets to create the strong gradient field required for high resolution MPI. However, using limits of view (FOV) due large amount energy move free point (FFP) from center scanner. To address this issue, an alternative approach called "Traveling Wave MPI" is here presented. This employs a novel system, dynamic linear array, cover FOV while dynamically creating gradient. The proposed design also enables so-called...

While magnetic particle imaging (MPI) constitutes a novel biomedical technique for tracking superparamagnetic nanoparticles in vivo, unlike resonance (MRI), it cannot provide anatomical background information. Until now these two modalities have been performed separate scanners and image co-registration has hampered by the need to reposition sample both systems as similarly possible. This paper presents bimodal MPI-MRI-tomograph that combines single system.MPI MRI images can thus be acquired...

Magnetic particle imaging (MPI) is a non-invasive modality for direct detection of superparamagnetic iron-oxide nanoparticles based on the nonlinear magnetization response magnetic materials to alternating fields. This highly sensitive and rapid method allows both quantitative qualitative analysis measured signal. Since first publication MPI in 2005 several different scanner concepts have been presented 2009 vivo results beating mouse heart were shown. However, since field view (FOV)...

Abstract Magnetic Particle Imaging (MPI) is a promising new tomographic modality for fast as well three-dimensional visualization of magnetic material. For anatomical or structural information an additional imaging such computed tomography (CT) required. In this paper, the first hybrid MPI-CT scanner multimodal providing simultaneous data acquisition presented.

Abstract The extremely anisotropic bonding properties of the narrow gap semiconductor bismuth telluride (Bi 2 Te 3 ) with sandwich structure is studied by inelastic neutron scattering. In combination lattice dynamical shell model calculations, new information obtained on complex forces this structured V–VI semiconductor. character leads predominantely to three‐dimensional behavior. No characteristic two‐dimensional can be observed.

Since the first publication in 2005, several different scanner types for magnetic particle imaging (MPI) have been presented. One of these concepts is traveling wave MPI (TWMPI). It uses a dynamic linear gradient array, which generates and moves field free point with strong gradient, necessary scanning sample 3-D. Due to properties TWMPI device, very fast 2-D frame rates higher than 1500 frames/s possible (superspeed mode). Using superspeed mode high speed measurements are conceivable, e.g.,...

A modular low-noise seven-channel SQUID-magnetometer for biomagnetic measurements was developed. The DC-SQUIDs are prepared by thin film technology based on the materials NbN-MgO-NbN, and show a flux noise below 10 mu Phi /sub 0// square root Hz. signal is picked up with first-order wire-wound gradiometers of 2-cm diameter coupled to SQUIDs integrated coupling coils. Individual channels can be replaced from system, various used giving flexible system. electronics flux-locked-loop method...

Computer simulations of the reconstruction and imaging neural currents from their external magnetic fields are presented. The method is based on Fourier transformed Maxwell equations in combination with Whittaker-Shannon sampling theorem. simultaneous more than one current generator without any special physiological model assumptions density distribution discussed.

A 19-channel SQUID system for biomagnetic measurements has been developed. This differs from standard instruments in its modular approach. Various gradiometers can be coupled to the SQUIDs, cryogenic allows exchange of single channels and electronics is based on a cassette system. Problems with thermal insulation, vibrations tilted gradiometer geometries are discussed solutions presented.

Linear estimation theory incorporating statistical a priori knowledge is applied to the inverse problem of reconstructing static 3-D vector source field from another measurement field. The motivation for this development reconstruct electric current distributions set magnetic measurements. Such capability would be useful clinical determination neural currents, example. A simulation presented demonstrate reconstruction class simple nonbiological objects, and show dependence these...

Since the introduction of magnetic particle imaging in 2005, several different types scanner were presented. One them is traveling wave (TWMPI) scanner. It uses for a dynamic linear gradient array generation strong and field free point. An unresolved issue TWMPI approach so far non-isotropic spatial resolution. As an alternative this paper, rotating slice scanning mode presented to overcome issue. This rotates scanning-slices around axis projection reconstruction method get 3-D volume with...

Magnetic particle imaging (MPI) is a young modality using the nonlinear magnetization properties of superparamagnetic iron-oxide nanoparticles to acquire them. It highly sensitive and fast method allowing both quantitative qualitative analysis measured signal. Since its first publication in 2005, several different scanner types have been presented. Most them work with permanent magnets therefore small field view. In 2014, an alternative concept, traveling wave MPI (TWMPI), was presented,...

To improve the reconstruction quality for quantitative T1 and T2 measurements using inversion recovery (IR) TrueFISP sequence to demonstrate potential multicomponent analysis.The iterative method takes advantage of high redundancy in smooth exponential signals principle component analysis (PCA). Multicomponent information is preserved allows voxel-by-voxel computation relaxation time spectra with an inverse Laplace transform. Off-resonance effects are analytically numerically investigated a...

Samples of the quasi-two-dimensional ferromagnet K2CuF4 with a thickness comparable radiation wavelength have been studied by magnetic resonance in millimetre wave range. The observed transmission and reflection spectra can be explained only on basis electromagnetic propagation polariton effects thus provide experimental evidence for these quasiparticles mixed magnon photon character. In particular, clearly show 'polariton gap' between anti-resonance field while exhibit 'restsrahlen band'...

Ferromagnetic resonance of quasi-two-dimensional K2CuF4 Has been studied for various frequencies between 10 and 100 GHz (external magnetic fields 0.5 3.5T) at temperatures up to 30K. For 35 GHz, the measurements were performed with conventional microwave techniques spectra exhibited structures which are analysed as originating from magnetostatic modes. higher frequencies, a quasi-optical method has used here in absorption explained propagation effects ferromagnetic polaritons. From data,...

Magnetic particle imaging (MPI) was first presented in 2005. It is based on the nonlinear response of ferromagnetic material and fact that magnetization saturates at sufficiently high magnetic fields. In contrast to resonance (MRI), MPI directly detects concentration distribution superparamagnetic iron-oxide nanoparticles without any background tissue. To overcome this issue, a traveling wave (TWMPI) device combined with low field MRI scanner demonstrate feasibility hybrid scanner, which...

The sample shown in fig. 1B contains a tube with an inner diameter of 860 μm filled undiluted Resovist® (Bayer-Schering, Germany) embedded acrylic glass. acquisition time for one slice is t <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">slice</sub> =1/f xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> , 4000 averages and f =920 Hz the overall t=4000/f =4,35 s. intrinsic spatial resolution given by setup was calculated to be 2 mm z- 4...

Magnetic particles have become a core ingredient for many applications in chemistry, biology, and medical diagnostics, e.g., as basis bioanalytical methods or tracer material imaging. This paper discusses the theory presents numerical simulations of new method called rotational drift spectroscopy (RDS), which uses rotating magnetic fields measuring properties nanoparticles (MNPs) liquid suspensions. The RDS signal is based on nonlinear behavior MNPs fields, highly dependent well their...

Determining the composition of solid materials is high interest in areas such as material research or quality assurance. There are several modalities at disposal with which various parameters can be observed, but those only magnetic resonance imaging (MRI) computer tomography (CT) offer anon-destructive determination distribution 3D. A novel non-destructive method Magnetic Particle Imaging (MPI), uses dynamic fields for a direct With this approach, it possible to determine and differentiate...

The infrared reflectivity and Raman spectra of single crystals (NH4)3H(SO4)2 have been studied in the temperature range 10-300 K. A three-parameter classical oscillator fit to data has obtained determine optical constants. effects increased anharmonicity ordering coupled motions cations anions are witnessed spectrum ferroelectric phase. show a reversal trend shift longitudinal (LO) mode frequency phase IV. This behaviour LO modes is correlated with fast rate decrease experimentally measured...