A Comparison of Permanent Magnet and Wound Rotor Synchronous Machines for Portable Power Generation

Permanent magnet and wound rotor synchronous machines (PMSMs and WRSMs) are often used in diesel engine-based portable power generation systems. In these applications, there is a growing desire to improve machine efficiency in order to reduce fossil fuel requirements. In addition, there is a desire to reduce mass to improve mobility. To attempt to address these competing performance objectives, a system analyst is confronted with numerous choices, including machine type (PM or WR), converter architecture (active/passive), and control. Herein, to assist the analyst, design tools capable of performing automated multi-objective optimization of PMSMs and WRSMs connected to both active and passive rectifiers are described. The tools are then used to derive tradeoffs between mass and efficiency for a 3 kW application

Machine-Readable Privacy Certificates for Services

Privacy-aware processing of personal data on the web of services requires managing a number of issues arising both from the technical and the legal domain. Several approaches have been proposed to matching privacy requirements (on the clients side) and privacy guarantees (on the service provider side). Still, the assurance of effective data protection (when possible) relies on substantial human effort and exposes organizations to significant (non-)compliance risks. In this paper we put forward the idea that a privacy certification scheme producing and managing machine-readable artifacts in the form of privacy certificates can play an important role towards the solution of this problem. Digital privacy certificates represent the reasons why a privacy property holds for a service and describe the privacy measures supporting it. Also, privacy certificates can be used to automatically select services whose certificates match the client policies (privacy requirements). Our proposal relies on an evolution of the conceptual model developed in the Assert4Soa project and on a certificate format specifically tailored to represent privacy properties. To validate our approach, we present a worked-out instance showing how privacy property Retention-based unlinkability can be certified for a banking financial service.Comment: 20 pages, 6 figure

Dynamic Changes in Brain Mesenchymal Perivascular Cells Associate with Multiple Sclerosis Disease Duration, Active Inflammation, and Demyelination

Vascular changes, including blood brain barrier destabilization, are common pathological features in multiple sclerosis (MS) lesions. Blood vessels within adult organs are reported to harbor mesenchymal stromal cells (MSCs) with phenotypical and functional characteristics similar to pericytes. We performed an immunohistochemical study of MSCs/pericytes in brain tissue from MS and healthy persons. Post-mortem brain tissue from patients with early progressive MS (EPMS), late stage progressive MS (LPMS), and healthy persons were analyzed for the MSC and pericyte markers CD146, platelet-derived growth factor receptor beta (PDGFRβ), CD73, CD271, alpha-smooth muscle actin, and Ki67. The MS samples included active, chronic active, chronic inactive lesions, and normal-appearing white matter. MSC and pericyte marker localization were detected in association with blood vessels, including subendothelial CD146+PDGFRβ+Ki67+ cells and CD73+CD271+PDGFRβ+Ki67– cells within the adventitia and perivascular areas. Both immunostained cell subpopulations were termed mesenchymal perivascular cells (MPCs). Quantitative analyses of immunostainings showed active lesions containing increased regions of CD146+PDGFRβ+Ki67+ and CD73+CD271+PDGFRβ+Ki67– MPC subpopulations compared to inactive lesions. Chronic lesions presented with decreased levels of CD146+PDGFRβ+Ki67+ MPC cells compared to control tissue. Furthermore, LPMS lesions displayed increased numbers of blood vessels harboring greatly enlarged CD73+CD271+ adventitial and perivascular areas compared to control and EPMS tissue. In conclusion, we demonstrate the presence of MPC subgroups in control human brain vasculature, and their phenotypic changes in MS brain, which correlated with inflammation, demyelination and MS disease duration. Our findings demonstrate that brain-derived MPCs respond to pathologic mechanisms involved in MS disease progression and suggest that vessel-targeted therapeutics may benefit patients with progressive MS

Draft genome sequence of the bacteriocinogenic strain Enterococcus faecalis DBH18, isolated from mallard ducks (Anas platyrhynchos)

Here, we report the draft genome sequence of Enterococcus faecalis DBH18, a bacteriocinogenic lactic acid bacterium (LAB) isolated from mallard ducks (Anas platyrhynchos). The assembly contains 2,836,724 bp, with a G+C content of 37.6%. The genome is predicted to contain 2,654 coding DNA sequences (CDSs) and 50 RNAs

Detection of very high energy gamma-ray emission from the gravitationally-lensed blazar QSO B0218+357 with the MAGIC telescopes

Context. QSO B0218+357 is a gravitationally lensed blazar located at a redshift of 0.944. The gravitational lensing splits the emitted radiation into two components, spatially indistinguishable by gamma-ray instruments, but separated by a 10-12 day delay. In July 2014, QSO B0218+357 experienced a violent flare observed by the Fermi-LAT and followed by the MAGIC telescopes. Aims. The spectral energy distribution of QSO B0218+357 can give information on the energetics of z ~ 1 very high energy gamma- ray sources. Moreover the gamma-ray emission can also be used as a probe of the extragalactic background light at z ~ 1. Methods. MAGIC performed observations of QSO B0218+357 during the expected arrival time of the delayed component of the emission. The MAGIC and Fermi-LAT observations were accompanied by quasi-simultaneous optical data from the KVA telescope and X-ray observations by Swift-XRT. We construct a multiwavelength spectral energy distribution of QSO B0218+357 and use it to model the source. The GeV and sub-TeV data, obtained by Fermi-LAT and MAGIC, are used to set constraints on the extragalactic background light. Results. Very high energy gamma-ray emission was detected from the direction of QSO B0218+357 by the MAGIC telescopes during the expected time of arrival of the trailing component of the flare, making it the farthest very high energy gamma-ray sources detected to date. The observed emission spans the energy range from 65 to 175 GeV. The combined MAGIC and Fermi-LAT spectral energy distribution of QSO B0218+357 is consistent with current extragalactic background light models. The broad band emission can be modeled in the framework of a two zone external Compton scenario, where the GeV emission comes from an emission region in the jet, located outside the broad line region.Comment: 11 pages, 6 figures, accepted for publication in A&

Limits to dark matter annihilation cross-section from a combined analysis of MAGIC and Fermi-LAT observations of dwarf satellite galaxies

We present the first joint analysis of gamma-ray data from the MAGIC Cherenkov telescopes and the Fermi Large Area Telescope (LAT) to search for gamma-ray signals from dark matter annihilation in dwarf satellite galaxies. We combine 158 hours of Segue 1 observations with MAGIC with 6-year observations of 15 dwarf satellite galaxies by the Fermi-LAT. We obtain limits on the annihilation cross-section for dark matter particle masses between 10 GeV and 100 TeV - the widest mass range ever explored by a single gamma-ray analysis. These limits improve on previously published Fermi-LAT and MAGIC results by up to a factor of two at certain masses. Our new inclusive analysis approach is completely generic and can be used to perform a global, sensitivity-optimized dark matter search by combining data from present and future gamma-ray and neutrino detectors.Comment: 19 pages, 3 figures. V2: Few typos corrected and references added. Matches published version JCAP 02 (2016) 03

The major upgrade of the MAGIC telescopes, Part II: A performance study using observations of the Crab Nebula

MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes located in the Canary island of La Palma, Spain. During summer 2011 and 2012 it underwent a series of upgrades, involving the exchange of the MAGIC-I camera and its trigger system, as well as the upgrade of the readout system of both telescopes. We use observations of the Crab Nebula taken at low and medium zenith angles to assess the key performance parameters of the MAGIC stereo system. For low zenith angle observations, the standard trigger threshold of the MAGIC telescopes is ~50GeV. The integral sensitivity for point-like sources with Crab Nebula-like spectrum above 220GeV is (0.66+/-0.03)% of Crab Nebula flux in 50 h of observations. The angular resolution, defined as the sigma of a 2-dimensional Gaussian distribution, at those energies is < 0.07 degree, while the energy resolution is 16%. We also re-evaluate the effect of the systematic uncertainty on the data taken with the MAGIC telescopes after the upgrade. We estimate that the systematic uncertainties can be divided in the following components: < 15% in energy scale, 11-18% in flux normalization and +/-0.15 for the energy spectrum power-law slope.Comment: 21 pages, 25 figures, accepted for publication in Astroparticle Physic

Multi-Wavelength Observations of the Blazar 1ES 1011+496 in Spring 2008

The BL Lac object 1ES 1011+496 was discovered at Very High Energy gamma-rays by MAGIC in spring 2007. Before that the source was little studied in different wavelengths. Therefore a multi-wavelength (MWL) campaign was organized in spring 2008. Along MAGIC, the MWL campaign included the Metsahovi radio observatory, Bell and KVA optical telescopes and the Swift and AGILE satellites. MAGIC observations span from March to May, 2008 for a total of 27.9 hours, of which 19.4 hours remained after quality cuts. The light curve showed no significant variability. The differential VHE spectrum could be described with a power-law function. Both results were similar to those obtained during the discovery. Swift XRT observations revealed an X-ray flare, characterized by a harder when brighter trend, as is typical for high synchrotron peak BL Lac objects (HBL). Strong optical variability was found during the campaign, but no conclusion on the connection between the optical and VHE gamma-ray bands could be drawn. The contemporaneous SED shows a synchrotron dominated source, unlike concluded in previous work based on nonsimultaneous data, and is well described by a standard one zone synchrotron self Compton model. We also performed a study on the source classification. While the optical and X-ray data taken during our campaign show typical characteristics of an HBL, we suggest, based on archival data, that 1ES 1011+496 is actually a borderline case between intermediate and high synchrotron peak frequency BL Lac objects.Comment: 13 pages, accepted for publication in MNRA