<b><i>Objective:</i></b> To evaluate the visible and quantitative anatomic distribution of fluorine-18–labeled l-DOPA in healthy human brain, to thereby expand understanding extrastriatal sites levodopa function, provide a broader foundation for clinical research studies fluoroDOPA accumulation patients. <b><i>Methods:</i></b> The authors performed dynamic three-dimensional PET imaging 10 volunteers analyzed images visually quantitatively. Twenty-eight regions interest were applied...

Dual-modality imaging, using Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET) simultaneously, is a powerful tool to gain valuable information correlating structure with function in biomedicine. The advantage of this dual approach that the strengths one modality can balance weaknesses other. However, success technique requires developing imaging probes suitable for both. Here, we report on development nanoparticle labeling procedure via covalent bonding carbon-11 PET...

Stationary DC electric fields are determined by the resistivity distribution of insulation materials. In presence interfaces between different materials, charge accumulation at these boundary layers may have a significant influence on field and with it breakdown strength arrangement. many previous works, surface charging model spacers was investigated. However, ion flow problem to properly account for conduction in gas has not yet been solved. The role sources behavior resulting currents...

Stationary DC electric fields are determined by the resistivity distribution of insulation materials. In presence interfaces between different materials, charge accumulation at these boundary layers may have a significant influence on field and with it breakdown strength arrangement. many previous works, surface charging model spacers was investigated. However, ion flow problem to properly account for conduction in gas has not yet been solved. The role sources behavior resulting currents...

In the present contribution, we analyze and quantify micro-discharge currents originating from rough electrode surfaces in HVDC gas insulated switchgear (GIS) applications. These can be significantly larger than those phase caused by natural ionization or bulk conduction solid insulators. They may thus dominate charging of insulator surface are a key dimensioning criterion. Five different systems with different, but clearly defined, roughness were designed. To amplitude micro discharge...

Surface charge on dielectric surfaces can alter the field conditions of insulation systems substantially. In this work, lightning impulse experiments are compared with a simulation model for surface charging in rod-barrier-plane geometries. The is based saturation assumption, i.e., zero normal electric air pointing onto surface, which prevents further charging. This hypothesis holds well most geometries, as long there no leader discharges or restrikes (also known back discharges). Restrikes...

In this paper, a comprehensive design procedure for high voltage pulse power transformers is presented. The based on the finite element method (FEM) and contains an electrical model, magnetical thermal model of transformer isolation design. addition, to avoid overvoltages within winding, dynamic distribution included in approach, as well. For validation models procedure, prototype has been built. There, main focus evaluating parasitics, which are crucial shape output pulse. Further, will be...

Stationary DC electric fields are determined by the resistivity distribution of used insulation materials. In presence interfaces between different materials, charge accumulation at these boundary layers may have a significant influence on field and with it breakdown strength arrangement. To investigate understand charging processes, measurements accumulated surface charges to be performed. our research we measure potential, as is consequence charges, close Kelvin Probe like widely done in...

We describe a wireless power transfer (WPT) system for linear drives based on inductive resonant coupling. The is capable of continuously transmitting from the transmitter to receiver coil, independent its motion or position. paper proposes solution and presents rigorous analysis by means 2-D 3-D FEM simulations. simulations are combined in order compute parameters coupling coils. obtained solutions further optimized Matlab connecting an optimization algorithm Linear Regression with circuit...

Solid state transformers (SSTs) are believed to play a major role in the near future due their additional features compared conventional transformers. SSTs combination of power electronics and transformer. The function this device is commute signal into kHz range before it transformed another voltage with transformer within SST. Many different topologies for electronic part SST applications have been implemented presented literature. newer publications use SiC MOSFETs high achievable...

Surface charging is one of the key problems in HVDC insulation development and accumulated surface charge on insulator has thus to be quantified. The use a vibrating Kelvin probes for this purpose became quite common last years according literature. With probe potential due charges can measured without contacting surface. Due its working principle, distribution convolution actual spatial -rather broad- response function probe. This imposes some limits smallest detectable features an...

The effect of barrier systems on electrical breakdown is well known and wide use in the field high voltage engineering. As shown literature, barriers can increase an electrode configuration. surface conductivity system has not yet been studied full detail. aim this contribution to show effect. For that purpose, we investigated a rod plane arrangement with 80mm distance between (rod) grounded plate electrode. A single was placed its resistivity decreased systematically. decrease decreasing...

PET brings the promise of quantitative imaging in-vivo distribution any positron emitting nuclide, a list with hundreds candidates. All but few these, "pure positron" emitters, have isotropic coincident gamma rays that give rise to misrepresented events in sinogram and resulting reconstructed image. Of particular interest are /sup 10/C, 14/O, 38/K, 52m/Mn, 60/Cu, 61/Cu, 94m/Tc, 124/I, each having high-energy gammas Compton-scattered down into 511 keV window. The problems arising from "third...

As gas insulated DC transmission systems unite the advantages of space saving installation and big capacity, this technology will become essential soon. The main problem in operation with respect to insulation seems be identified today, which is charge accumulation on surface insulators, so called spacers. These trapped charges can cause a reduction dielectric strength lead breakdown, especially at polarity reversals overvoltages. For experiments, full encapsulated test setup was...

Linear induction motors (LIMs) are presently considered as an interesting and promising solution for future transportation systems, motion control applications, linear automation etc. Contrary to their rotational counterparts, simulation based design optimization of LIMs is still open research subject due specific geometrical- electromagnetic features. This paper presents 1-D analytical- 2-D/3-D Finite-Element-Method-based numerical modeling LIMs. To demonstrate different levels accuracy...