Search results for "width [Lambda(1405)]"
showing 10 items of 330 documents
Four-Level Three-Phase Inverter With Reduced Component Count for Low and Medium Voltage Applications
2021
This paper proposes a novel three-phase topology with a reduced component count for low- and medium-voltage systems. It requires three bidirectional switches and twelve unidirectional switches for producing four-level voltages without using flying capacitors or clamping diodes, reducing the size, cost, and losses. Removing flying capacitors and clamping diodes allows it to simplify control algorithms and increase the reliability, efficiency, and lifetime. A modified low-frequency modulation (LFM) scheme is developed and implemented on the proposed topology to produce a staircase voltage with four steps. Further, a level-shifted pulse width modulation (LSPWM) is used to reduce the filter siz…
Dead-time impact on the harmonic distortion and conversion efficiency in a three-phase five-level Cascaded H-Bridge inverter: mathematical formulatio…
2023
To avoid leg short-circuit in inverters, dead time must be introduced on leg gate signals. Dead time affects the inverter output voltage fundamental harmonic amplitude, voltage harmonic distortion and inverter efficiency by introducing additional voltage drops. In this regard, dead time effects have been widely investigated for traditional two-level three-phase voltage source inverters in the literature but not extensively for multilevel topology structures. This paper provides a detailed analysis of dead time impact on the harmonic distortion and efficiency of Cascaded H-Bridges Multilevel Inverters (CHBMIs). For this purpose, a general mathematical formulation to determine voltage drop du…
Initial results on energy resolution of the NEXT-White detector
2018
One of the major goals of the NEXT-White (NEW) detector is to demonstrate the energy resolution that an electroluminescent high pressure xenon TPC can achieve for high energy tracks. For this purpose, energy calibrations with 137Cs and 232Th sources have been carried out as a part of the long run taken with the detector during most of 2017. This paper describes the initial results obtained with those calibrations, showing excellent linearity and an energy resolution that extrapolates to approximately 1% FWHM at Q$_{\beta\beta}$.
High-Speed Machines: Typologies, Standards, and Operation under PWM Supply
2018
This paper presents an overview of the most recent state of the art in the field of high-speed electric machines fed through high-frequency converters. This type of systems is rapidly wide spreading in aeronautical and automotive applications, as well as microturbines. Each typology has its own advantages and downsides, which are analytically presented in this paper. Some types of high-speed electric machines require high-frequency voltage supply, highly stressing the dielectric materials of the winding insulation system. For this reason, in high-speed electric drives, premature failure may occur and a reduction of the total system reliability has been observed in the past years. Such issue…
Adaptive Contention Resolution for VoIP Services in the IEEE 802.16 Networks
2007
In the IEEE 802.16 networks, a subscriber station can use the contention slots to send bandwidth requests to the base station. The contention resolution mechanism is controlled by the backoff start/end values and a number of the request transmission opportunities. These parameters are set by the base station and are announced to subscriber stations in the management messages. In the case of the VoIP services, it is critical that the contention resolution occurs within the specified time interval to meet the VoIP QoS requirements. Thus, it is the responsibility of the base station to set correct contention resolution parameters to ensure the QoS requirements. This paper presents analytical c…
Adaptive contention resolution parameters for the IEEE 802.16 networks
2007
In the IEEE 802.16 networks, the base station allocates resources to subscriber stations based on their QoS requirements and bandwidth request sizes. A subscriber station can send a bandwidth request when it has an uplink grant allocated by the base station or by taking part in the contention resolution mechanism. This paper presents analytical calculations for parameters that control the contention resolution process in the IEEE 802.16 networks. In particular, the backoff start/end values and the number of request transmission opportunities are considered. The simulation results confirm the correctness of theoretical calculations. They also reveal that the adaptive parameter tuning results…
Raman spectroscopy of synthetic, geological and biological vaterite: a Raman spectroscopic study
2009
Raman spectroscopy was used to study vaterite samples of biological, geological and synthetic origin. The Raman band positions and the full width at half-maximum (FWHM) of the lattice modes and the internal modes of the carbonate ion of all specimens show no significant differences between vaterites of different origin. With increasing Mg concentrations, synthetic vaterite samples show increasing FWHM in the region of the lattice modes and the three ν1 bands, whereas no change in luminescence was detected. In contrast, in situ measurements of vaterite areas in freshwater cultured pearls (FWCPs) by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) together with the Rama…
GekkoFS — A Temporary Burst Buffer File System for HPC Applications
2020
Many scientific fields increasingly use high-performance computing (HPC) to process and analyze massive amounts of experimental data while storage systems in today’s HPC environments have to cope with new access patterns. These patterns include many metadata operations, small I/O requests, or randomized file I/O, while general-purpose parallel file systems have been optimized for sequential shared access to large files. Burst buffer file systems create a separate file system that applications can use to store temporary data. They aggregate node-local storage available within the compute nodes or use dedicated SSD clusters and offer a peak bandwidth higher than that of the backend parallel f…
An FPGA based Topological Processor Prototype for the ATLAS Level-1 Trigger Upgrade
2012
By 2014 the LHC will collide proton bunches at 14TeV with an increased instantaneous luminosity up to 3·10³⁴cm⁻²s⁻¹. The resulting higher event rate will challenge the existing ATLAS trigger system. A reduction on the trigger rate can be achieved by selecting interesting channels based on their expected decay topology and thus reducing background. This will be achieved by introducing of a new FPGA based module in the Level-1 trigger: the Topological Processor L1Topo. With L1Topo it will be possible for the first time to concentrate detailed information from the entire calorimeters and the muon detector into a single module. L1Topo will receive a total aggregate bandwidth of 1Tb/s. The data …
Ultrascale+ for the new ATLAS calorimeter trigger board dedicated to jet identification
2018
To cope with the expected increase in luminosity at the Large Hadron Collider in 2021, the ATLAS collaboration is planning a major detector upgrade to be installed during Long Shutdown 2. As a part of this, the Level 1 trigger, based on calorimeter data, will be upgraded to exploit the fine granularity readout using a new system of Feature EXtractors (FEXs), which each reconstruct different physics objects for the trigger selection. The Jet FEX (jFEX) is one of three FEXs and has been conceived to identify small/large area jets, large area tau leptons, missing transverse energy and the total sum of the transverse energy. The use of the latest generation Xilinx Field Programmable Gate Array …