Search results for " processing"
showing 10 items of 7549 documents
A concept for a magnetic particle imaging scanner with Halbach arrays
2020
Magnetic particle imaging (MPI) is a new medical imaging technique visualizing the concentration distribution of superparamagnetic nanoparticles used as tracer material. MPI is not yet in clinical routine, since one of the challenges is the upscaling of scanners. Typically, the magnetic fields of MPI scanners are generated electromagnetically, resulting in an immense power consumption but providing high flexibility in terms of adjusting the field strengths and very fast image acquisition rates. Permanent magnets provide high flux densities and do not need any power supply. However, the flux density is not adjustable, and a mechanical movement is slow compared to electromagnetically varying …
First operation of the superconducting Darmstadt linear electron accelerator as an energy recovery linac
2020
The superconducting Darmstadt linear electron accelerator (S-DALINAC) has been operated as an energy recovery linac (ERL) for the first time. The S-DALINAC is a recirculating superconducting radio-frequency (SRF) accelerator and had been upgraded with an additional recirculation beamline. It features a path length adjustment system that provides a freedom of choice of 360\ifmmode^\circ\else\textdegree\fi{} for the rf phase difference between the electron bunches recirculated through the new beamline and the phase of the accelerating ${\mathrm{TM}}_{010}$ mode of the oscillating electromagnetic field in the SRF cavities of the accelerator. A choice of around 180\ifmmode^\circ\else\textdegree…
Design and Study of a Wide-Band Printed Circuit Board Near-Field Probe
2021
Magnetic near-field probes (NFP) represent a suitable tool to measure the magnetic field level from a small electromagnetic interference (EMI) source. This kind of antenna is useful as a magnetic field probe for pre-compliance EMC measurements or debugging tasks since the user can scan a printed circuit board (PCB) looking for locations with strong magnetic fields. When a strong H-field point is found, the designer should check the PCB layout and components placement in that area to detect if this could result in an EMI source. This contribution focuses on analyzing the performance of an easy to build and low-cost H-field NFP designed and manufactured using a standard PCB stack-up. Thereby,…
Compensation of missing wedge effects with sequential statistical reconstruction in electron tomography.
2014
Electron tomography (ET) of biological samples is used to study the organization and the structure of the whole cell and subcellular complexes in great detail. However, projections cannot be acquired over full tilt angle range with biological samples in electron microscopy. ET image reconstruction can be considered an ill-posed problem because of this missing information. This results in artifacts, seen as the loss of three-dimensional (3D) resolution in the reconstructed images. The goal of this study was to achieve isotropic resolution with a statistical reconstruction method, sequential maximum a posteriori expectation maximization (sMAP-EM), using no prior morphological knowledge about …
High-pressure optical absorption in InN: Electron density dependence in the wurtzite phase and reevaluation of the indirect band gap of rocksalt InN
2012
We report on high-pressure optical absorption measurements on InN epilayers with a range of free-electron concentrations (5×1017–1.6×1019 cm−3) to investigate the effect of free carriers on the pressure coefficient of the optical band gap of wurtzite InN. With increasing carrier concentration, we observe a decrease of the absolute value of the optical band gap pressure coefficient of wurtzite InN. An analysis of our data based on the k·p model allows us to obtain a pressure coefficient of 32 meV/GPa for the fundamental band gap of intrinsic wurtzite InN. Optical absorption measurements on a 5.7-μm-thick InN epilayer at pressures above the wurtzite-to-rocksalt transition have allowed us to o…
EPR on Radiation-Induced Defects in SiO2
2014
Continuous-wave electron paramagnetic resonance (EPR) spectroscopy has been the technique of choice for the studies of radiation-induced defects in silica (SiO2) for 60 years, and has recently been expanded to include more sophisticated techniques such as high-frequency EPR, pulse electron nuclear double resonance (ENDOR), and pulse electron spin echo envelope modulation (ESEEM) spectroscopy. Structural models of radiation-induced defects obtained from single-crystal EPR analyses of crystalline SiO2 (alfa-quartz) are often applicable to their respective analogues in amorphous silica (a-SiO2), although significant differences are common.
A Web Application for Interactive Visualization of European Basketball Data
2020
The statistical analysis of basketball games is a fast-growing field. Certainly, basketball data are scientifically relevant because an appropriate analysis provides a great deal of information about the performance of both players and teams. The number of games played each season generates a large amount of data worth analyzing. Basketball analytics is well established in U.S. leagues. In Europe, however, it has not been duly developed. This study focuses on the top three European team competitions: the EuroLeague, the EuroCup, and the Spanish ACB (Association of Basketball Clubs, acronym in Spanish) league. Their official websites provide access to game data for anyone who is interested, …
T-wave alternans analysis improvement by means of curve alignment prior to distance calculation.
2007
Tracking of repolarization instabilities in the ECG, such as T-wave alternans (TWA), has become a popular non-invasive method to assess the vulnerability to malignant arrhythmic events. These instabilities are usually characterized by small amplitude changes and their measurement is difficult due to the presence of noise and artifacts. Several methods have been recently proposed to address this problem. Most of them are based on amplitude analysis of beat-to-beat alternation of the T wave. This paper describes a preprocessing stage intended to be used prior to amplitude analysis and aimed at improving the alignment between consecutive T waves. This increases the accuracy of the difference c…
A software tool to acquire, synchronise and playback multimedia data: an application in kinesiology
2000
Assessing the physical condition of the human body frequently requires evaluating different tests performed by different devices. This information has to be analysed simultaneously to derive conclusions, and so a temporal relationship must be established between the data sources. In this paper, synchronisation of the sources of information is achieved by synchronising the clocks of computers connected in a Local Area Network. A clock synchronisation protocol is used and a global time is stamped in each information data flow. During analysis, the time-stamp is used to playback the data in a synchronised way. The proposed system is valid for any medical application in which data synchronisati…
Early detection of contamination and defect in foodstuffs by electronic nose: A review
2017
Abstract Electronic nose (e-nose) has emerged as a potential instrument in various areas of food safety assessment for rapid early detection of contamination and defect in food production chain. E-nose is an innovative measurement system designed for detecting and discriminating complex odors through mimicking the working mechanism and the principal building blocks of the mammalian olfactory system. This paper describes a literature update of the applications of the e-nose for ensuring health and safety in the food industry. Finally, its future trend, perspectives and challenging problem are also mentioned.