Search results for "Width"
showing 10 items of 690 documents
XMM-Newton Large Program on SN1006 - I: Methods and Initial Results of Spatially-Resolved Spectroscopy
2015
Based on our newly developed methods and the XMM-Newton large program of SN1006, we extract and analyze the spectra from 3596 tessellated regions of this SNR each with 0.3-8 keV counts $>10^4$. For the first time, we map out multiple physical parameters, such as the temperature ($kT$), electron density ($n_e$), ionization parameter ($n_et$), ionization age ($t_{ion}$), metal abundances, as well as the radio-to-X-ray slope ($\alpha$) and cutoff frequency ($\nu_{cutoff}$) of the synchrotron emission. We construct probability distribution functions of $kT$ and $n_et$, and model them with several Gaussians, in order to characterize the average thermal and ionization states of such an extended s…
Determination of the Chiral Couplings L10 and C87 from Semileptonic τ Decays
2008
Using recent precise hadronic tau-decay data on the V-A spectral function, and general properties of QCD such as analyticity, the operator product expansion and chiral perturbation theory, we get accurate values for the QCD chiral order parameters L_10^r(M_rho) and C_87^r(M_rho). These two low-energy constants appear at order p^4 and p^6, respectively, in the chiral perturbation theory expansion of the V-A correlator. At order p^4 we obtain L_10^r(M_rho) = -(5.22\pm 0.06)10^{-3}. Including in the analysis the two-loop (order p^6) contributions, we get L_10^r(M_rho) = -(4.06\pm 0.39)10^{-3} and C_87^r(M_rho) = (4.89\pm 0.19)10^{-3}GeV^{-2}. In the SU(2) chiral effective theory, the correspon…
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…
Circulating histones contribute to monocyte and MDW alterations as common mediators in classical and COVID-19 sepsis
2022
Abstract Objective Histone proteins are physiologically involved in DNA packaging and gene regulation but are extracellularly released by neutrophil/monocyte extracellular traps and mediate thrombo-inflammatory pathways, associated to the severity of many human pathologies, including bacterial/fungal sepsis and COVID-19. Prominent and promising laboratory features in classic and viral sepsis emphasize monocyte distribution width (MDW), due to its ability to distinguish and stratify patients at higher risk of critical conditions or death. No data are available on the roles of histones as MDW modifiers. Design Comparison of MDW index was undertaken by routine hematology analyzer on whole bloo…
Morphological Characterization of Nordic Horseradish (Armoracia rusticana)
2019
AbstractMorphological diversity was studied in 101 accessions of horseradish (Armoracia rusticana) collected from old gardens in Denmark, Norway, Finland and Sweden. The characterization work was performed over three years, where a total of 19 descriptors from the UPOV guidelines TG/191/2-2001 were recorded each year. The results showed high diversity among the studied accessions, both for leaf and rhizome characters. A morphotype with long leaves and a high leaf length/leaf width quota was the most common, but also elliptic and heart-shaped leaf types were found. Some characters showed stability over the years, although there were variations in the results. Correlations between descriptors…
Effect of plot size on measured soil loss for two Italian experimental sites
2011
The objective of this investigation was to determine empirically the plot width and length effects on runoff volume, Ve, soil loss, Ae, and sediment concentration, Ce, by using data collected, at the temporal scale of the erosive event, on bare plots differing in width (2 to 8 m) and length (11 to 22 m) for two Italian stations (Masse, Umbria; Sparacia, Sicily). Mean results differed by a maximum factor of 1.6 for Ve, 1.8 for Ae and 1.2 for Ce when plots differing in width were compared and by a maximum factor of 1.4 for Ve, 1.2 for Ae and 1.3 for Ce when comparison between plot lengths was conducted. Differences between two plot widths or two plot lengths were not statistically significant…
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…
Temperature dependence of the E2h phonon mode of wurtzite GaN/AlN quantum dots
2008
Raman scattering has been used to study the temperature dependence of the frequency and linewidth of the E2h phonon mode of GaN/AlN quantum dot stacks grown on 6H-SiC. The evolution of the nonpolar phonon mode was analyzed in the temperature range from 80 to 655 K for both quantum dots and barrier materials. The experimental results are interpreted by comparison with a model that takes into account symmetric phonon decay and the different thermal expansions of the constituents of the heterostructure. We find a small increase in the anharmonic parameters of the phonon modes in the heterostructure with respect to bulk. jorbumar@alumni.uv.es Alberto.Garcia@uv.es Ana.Cros@uv.es