bluuebunny/crossref_metadata_2025 huggingface dataset:
Two‐dimensional encryption system for secure free‐space optical communication of time‐series data streams
Authors: Ikeda K. , Sato Y. , Koyama O. , Yamada M.
Published: May 2019

The importance of encryption in free‐space optical communication systems has been increasing due to their widespread use. Herein, for the first time, the authors propose a novel two‐dimensional encryption system for free‐space optical communication using two spatial patterns as encryption keys. A data stream is physically encrypted with optical signals to reduce the risk of unauthorised third‐party intrusion into communication. The encryption and restoration of a binary data stream using the proposed encryption system are confirmed by simulation results. The authors believe that, in the future, the proposed system could be used as an encryption method at the physical layer level to achieve the desired level of safety determined by the user.
Structure and the space vector modulation for a medium‐voltage power‐electronic‐transformer based on two seven‐level cascade H‐bridge inverters
Authors: Lewicki Arkadiusz , Morawiec Marcin
Published: May 2019

This study presents the structure and the space vector pulse‐width modulation (SVPWM) for power electronic transformer (PET) based on two seven‐level cascade H‐bridge (CHB) inverters. The DC links of CHB inverters are coupled with nine dual‐active bridge (DAB) converters with medium‐frequency transformers. The DC‐link voltages are equalised with two methods – through the control of DAB voltages and through the modulation strategy applied to both CHB inverters. In the proposed SVPWM, the influence of vector sequences on predicted DC‐link voltages is analysed, and the optimum vector sequence is selected to equalise them. Regardless of this, the proposed SVPWM strategy enables the proper generation of output voltage vector also in the case of DC‐link voltage imbalance – the calculation of the space‐vector area takes into consideration the inequality of the DC‐link voltages and its influence on the lengths and positions of active vectors. To simplify the modulation algorithm, the multilevel CHB inverter is considered as a set of three‐level inverters connected in series. Each of them is controlled using the same SVPWM algorithm. The proposed modulation method reuses the H‐bridges with zero duty cycles determined in the initial stages of the output voltage generation process. This enables the optimal management of the DC‐link voltage distribution. The experimental research was carried out on a 600 kW/3.3 kV PET. The results are presented in this study.
Tongue colour and coating prediction in traditional Chinese medicine based on visible hyperspectral imaging
Authors: Zhang Dong , Zhang Junhua , Wang Zheng , Sun Meijun
Published: May 2019

Tongue diagnosis is an important concept in Traditional Chinese Medicine (TCM). The tongue colour and coating can aid understanding of the body's physiological mechanisms, as well as the pathology of diseases. Existing research has focused on using digital images and tongue colour classification, without considering the other visible bands of information in the tongue. In this study, a visible hyperspectral image system, with an approximate spectral range of 400–1000 nm, was used to predict the tongue colour values and the coating position in TCM, and a stacked autoencoder (SAE) predict model based on spectral–spatial feature was performed to digital the tongue colour space and the coating. The experimental results show the effectiveness of the spectral–spatial feature with SAE model in predicting the CIELAB values of L, a, and coating position, thus the authors provide a new technique for the objective and digitising development of TCM.
Content‐based retinal image retrieval
Authors: Sukhia Komal Nain , Riaz Muhammad Mohsin , Ghafoor Abdul
Published: May 2019

The study presents a content‐based retrieval technique for retinal images. Given a query image, the aim is to automatically retrieve the relevant disease images (i.e. diabetic retinopathy, coats and choroidal neovascularisation) from the database. The proposed technique applies different pre‐processing steps to enhance the region of the exudate present in the retina. Segmentation step separates the exudates and vessels region to extract shape and texture features which are optimally combined with an automatic weight assignment approach. The simulations are performed on STARE dataset and compared with other existing techniques to ensure the significance of the proposed technique.
Black hole mass estimates in quasars
Authors: Marziani P. , del Olmo A. , Martínez-Carballo M. A. , Martínez-Aldama M. L. , Stirpe G. M. , Negrete C. A. , Dultzin D. , D’Onofrio M. , Bon E. , Bon N.
Published: May 2019

Context. The inter-line comparison between high- and low-ionization emission lines has yielded a wealth of information on the structure and dynamics of the quasar broad line region (BLR), including perhaps the earliest unambiguous evidence in favor of a disk + wind structure in radio-quiet quasars.

Aims. We carried out an analysis of the C IVλ1549 and Hβ line profiles of 28 Hamburg-ESO high-luminosity quasars and of 48 low-z, low-luminosity sources in order to test whether the width of the high-ionization line C IVλ1549 could be correlated with Hβ and be used as a virial broadening estimator.

Methods. We analyze intermediate- to high-S/N, moderate-resolution optical and near-infrared (NIR) spectra covering the redshifted C IVλ1549 and Hβ over a broad range of luminosity log L ∼ 44 − 48.5 [erg s−1] and redshift (0 − 3), following an approach based on the quasar main sequence.

Results. The present analysis indicates that the line width of C IVλ1549 is not immediately offering a virial broadening estimator equivalent to Hβ. At the same time a virialized part of the BLR appears to be preserved even at the highest luminosities. We suggest a correction to FWHM(C IVλ1549) for Eddington ratio (using the C IVλ1549 blueshift as a proxy) and luminosity effects that can be applied over more than four dex in luminosity.

Conclusions. Great care should be used in estimating high-L black hole masses MBH from C IVλ1549 line width. However, once a corrected FWHM C IVλ1549 is used, a C IVλ1549-based scaling law can yield unbiased MBH values with respect to the ones based on Hβ with sample standard deviation ≈0.3 dex.
Status of the Baikal-GVD Neutrino Telescope
Authors: Avrorin A.D. , Avrorin A.V. , Aynutdinov V.M. , Bannash R. , Belolaptikov I.A. , Brudanin V.B. , Budnev N.M. , Doroshenko A.A. , Domogatsky G.V. , Dvornický R. , Dyachok A.N. , Dzhilkibaev Zh.-A.M. , Fajt L. , Fialkovsky S.V. , Gafarov A.R. , Golubkov K.V. , Gorshkov N.S. , Gres T.I. , Kebkal K.G. , Kebkal O.G. , Khramov E.V. , Kolbin M.M. , Konischev K.V. , Korobchenko A.V. , Koshechkin A.P. , Kozhin V.A. , Kruglov M.V. , Kryukov M.K. , Kulepov V.F. , Kuleshov D.A. , Milenin M.B. , Mirgazov R.A. , Nazari V. , Panfilov A.I. , Petukhov D.P. , Pliskovsky E.N. , Rozanov M.I. , Rjabov E.V. , Rushay V.D. , Safronov G.B. , Šimkovic F. , Skurichin A.V. , Shaybonov B.A. , Solovjev A.G. , Sorokovikov M.N. , Shelepov M.D. , Suvorova O.V. , Shtekl I. , Tabolenko V.A. , Tarashansky B.A. , Yakovlev S.A. , Zagorodnikov A.V.
Published: May 2019

Currently in Lake Baikal a new-generation neutrino telescope is being deployed: Baikal-GVD, a deep underwater Cherenkov detector on the cubic-kilometer scale. This paper presents the status of the detector implementation and the first physical results obtained with the existing configuration.
Neutrinos from TXS 0506+056 prior to the 2017 gamma-ray flare
Authors: Finley Chad
Published: May 2019

On 2017 September 22, IceCube released a public alert announcing the detection of a well-reconstructed, high-energy neutrino event. Such alerts issued through the Extremely High Energy (EHE) alert stream occur roughly four times a year. Subsequent multimessenger follow-up identified that the event was coincident in direction and time with a gamma-ray flare from the blazar TXS 0506+056. This association prompted an archival analysis searching for additional neutrinos from the direction of TXS 0506+056 using 9.5 years of IceCube neutrino observations. An excess of neutrino events with respect to atmospheric backgrounds was found between September 2014 and March 2015. The analysis yields 3:5σ evidence for neutrino emission from the direction of TXS 0506+056, independent of and prior to the 2017 emission.
ANTARES-IceCube combined search for neutrino pointsources in the Southern Hemisphere
Authors: Illuminati Giulia
Published: May 2019

A search for cosmic neutrino point-like sources covering the Southern hemisphere is presented, using 9 years and 7 years of data from the ANTARES and IceCube neutrino telescopes, respectively. The advantageous field of view of ANTARES as well as the high statistics provided by IceCube are exploited to open a window in the Southern sky where the sensitivity to point-sources improves by a factor ~ 2 compared to individual analyses. An unbinned maximum likelihood method is used to search for a localised excess of muon events over the expected background. Before applying the method to the unblinded dataset, the sensitivity and discovery potential of the search are computed through dedicated pseudo-experiments.
Gravitational waves and neutrinos joint searches in the Mediterranean Sea
Authors: Baret Bruny
Published: May 2019

The recent detection of gravitational waves (GW) have launched effectively the field of multimessenger astronomy. High energy neutrinos (HEN) have been detected as a diffuse flux and show indications of transient point sources. They can bring crucial informations on cataclysmic cosmic events by identifying hadrons acceleration to high energies and pointing back to the source at the degree level which is an asset for follow-up of GW events with photonic telescopes. We will review the current searches for joint sources of gravitational waves and high energy neutrinos performed with the ANTARES telescope and the perspectives offered by its successor KM3NeT.
Searching for Optical Counterparts to High-Energy Neutrino Sources with the Zwicky Transient Facility
Authors: Rauch Ludwig
Published: May 2019

The IceCube neutrino observatory has discovered a flux of extragalactic neutrinos. However, the origin of these neutrinos is still unknown. Among the possible candidates are Gamma-Ray Bursts (GRBs), Core-Collapse Supernovae (SNe), Active Galactic Nuclei (AGN) and Tidal Disruption Events (TDEs) - all are accompanied by a characteristic optical counterpart. The goal of this study is thus to identify the neutrino sources by detecting their optical counterparts with the Zwicky Transient Facility (ZTF). ZTF features a high cadence northern-sky survey enabling realtime correlation of optical transients with high-energy neutrino candidates. In this talk I will highlight the multimessenger potential of ZTF for an online neutrino correlation study with Ice- Cube.
The Physics Potential of a Neutrino Beam from Protvino to KM3NeT/ORCA
Authors: Brunner Jürgen
Published: May 2019

The Protvino accelerator facility located in the Moscow region, Russia, is in a good position to offer a rich experimental research program in the field of neutrino physics. Of particular interest is the possibility to direct a neutrino beam from Protvino towards the KM3NeT/ORCA detector which is currently under construction in the Mediterranean sea 40 km offshore Toulon, France. Such an experiment, nicknamed P2O (Protvino-to-ORCA), would yield an unparalleled sensitivity to matter effects in the Earth, allowing for the determination of the neutrino mass ordering with a high level of certainty due to its baseline of 2595 km after only few years of running time at a modest beam intensity up to 100 kW. A second phase of the experiment comprizes a further intensity upgrade of the accelerator complex and a significant densification of the ORCA detector. This would allow for a competitive and complementary measurement of the leptonic CP-violating Dirac phase with a Mton detector but avoiding underground excavation costs.
A Beam from Protvino to the Mediterranean Sea
Authors: Garkusha V. , Ivanov S. , Maksimov A. , Novoskoltsev F. , Pimbursky Y. , Sinyukov R. , Sokolov A. , Zaitsev A.
Published: May 2019

The report overviews preliminary results on the feasibility to produce a neutrino beam based on the U-70 proton synchrotron at Protvino for a very long baseline experiment with the deep water ORCA detector in the Mediterranean Sea.
Particle Physics with ORCA
Authors: Domi Alba , Bourret Simon , Quinn Liam
Published: May 2019

KM3NeT is a Megaton-scale neutrino telescope currently under construction at the bottom of the Mediterranean Sea. When completed, it will consist of two separate detectors: ARCA (Astroparticle Research with Cosmics in the Abyss), optimised for high-energy neutrino astronomy, and ORCA (Oscillation Research with Cosmics in the Abyss) for neutrino oscillation studies of atmospheric neutrinos. The main goal of ORCA is the determination of the neutrino mass ordering (NMO). Nevertheless it is possible to exploit ORCA’s configuration to make other important measurements, such as sterile neutrinos, non standard interactions, tau-neutrino appearance, neutrinos from Supernovae, Dark Matter and Earth Tomography studies. Part of these analyses are summarized here.
Indirect Searches for Dark Matter with IceCube
Authors: Aguilar Sánchez Juan Antonio
Published: May 2019

The nature of dark matter remains one of the unsolved questions in modern cosmology and to understand its properties different experimental avenues are being explored. Indirect searches make use of the annihilation or decay products of dark matter as tracers to prove its existence. Unlike direct detections methods, indirect searches do not require specialized detectors as existing astro-particle experiments and facilities can be used to search for signatures of dark matter. Among the decay and annihilation products, neutrinos offer a unique way to search for dark matter since their low cross-section makes them capable of escaping from environments in which gamma rays will be absorbed, like the Sun or the Earth. The IceCube neutrino telescope is not only an excellent astro-particle detector, it also has lively program on dark matter searches with very competitive and complementary results to direct detection limits. These proceedings review the latests results of IceCube regarding the indirect search of dark matter with neutrinos.
Improving the directional reconstruction of PeV hadronic cascades in IceCube
Authors: Haack Christian , Lu Lu , Yuan Tianlu
Published: May 2019

Many neutrino interactions measured by the IceCube Neutrino Observatory produce only hadronic showers, which appear as almost point-like light emission due to the large detector spacing (125 m). At PeV energies these showers often saturate the PMTs closest to the interaction vertex - thus the reconstruction has to rely on more diffused photons which requires precise understanding of the optical properties of the Antarctic ice. Muons produced in the hadronic showers carry information about the neutrino direction, and their Cherenkov light arrives earlier than the photons emitted by the electromagnetic component. A new reconstruction method has been developed which explicitly takes into account the muonic component of hadronic showers and is shown to be robust against systematic ice uncertainties. By applying the new reconstruction, the angular resolution of multi-PeV cascade events can be significantly improved. This will potentially enable follow-up studies of the highest-energy cascade events measured by IceCube.
Core-Collapse Supernova neutrino detection with KM3NeT
Authors: Molla Marta Colomer , Lincetto Massimiliano
Published: May 2019

Core Collapse Supernovae (CCSNe) are explosive phenomena that may occur at the end of the life of massive stars, releasing over 99% of the energy through neutrino emission. While the explosion mechanism is not fully understood, neutrinos are believed to play an important role. The only detection as of today are the 24 neutrinos from SN1987A. The observation of the next Galactic CCSN will lead to important breakthroughs in astroparticle physics. For a Galactic CCSN, the KM3NeT ORCA and ARCA detectors in the Mediterranean Sea will observe a significant neutrino signal via the detection of Cherenkov light, mostly induced by Inverse Beta Decay interactions in sea water. The detection of coincident photons by the 31 photomultipliers of each KM3NeT digital optical module (DOM) allows for an efficient discrimination of the optical backgrounds.

The KM3NeT detection sensitivity to a Galactic CCSN and the potential to resolve the neutrino light-curve have been estimated relying on detailed Monte Carlo simulations. Specific criteria are proposed for the online triggering and the participation in the SNEWS network.
D-Egg: A next-generation optical module for IceCube
Authors: Makino Yuya
Published: May 2019

The Dual optical sensors in an Ellipsoid Glass for Gen2 (DEgg) is one of the optical modules being developed for the IceCube-upgrade and the IceCube-Gen2 projects. The D-Egg has two 8-inch high-quantum-efficiency PMTs facing downwards and upwards, which are coupled to a highly ultraviolet-transparent glass vessel to detect Cherenkov photons in nearly all directions. In this paper, expected performances of the D-Egg are discussed.
STRAW (STRings for Absorption length in Water): pathfinder for a neutrino telescope in the deep Pacific Ocean
Authors: Henningsen Felix ,   for the STRAW Collaboration
Published: May 2019

Recently, an opportunity for a pathfinder mission towards a new neutrino telescope appeared in the Pacific Ocean. An existing deep-sea electrooptical infrastructure maintained by Ocean Networks Canada could pose as the base towards a potential new large-volume neutrino telescope. Two groups from Technical University Munich and the University of Alberta pursued the optical characterization of the 2.6 km deep site calledCascada Basinwithin the scope of the “Strings for Absorption length in Water” (STRAW) project. We present a summary of the 1-year construction timeline, impressions of the detector performance and first results.
Moon shadow in ANTARES
Authors: Chiarusi Tommaso , Sanguineti Matteo
Published: May 2019

The ANTARES neutrino telescope is the largest Cherenkov detector currently in operation in Mediterranean sea. The search for point-like neutrino sources is one of the telescope goals. For this reason, both the detector angular resolution and the pointing accuracy need a proper estimation. Measuring the deficit of the atmospheric muons in the direction of the Moon induced by the absorption of primary cosmic rays, the so called Moon shadow, allows to evaluate the pointing performance of the telescope. In this contribution we show the result of the analysis of the data taken between 2007 and 2016. The Moon shadow is detected with 3.5σ significance. This is the first measurement of the ANTARES angular resolution for atmospheric muons and its absolute pointing using a celestial calibration source. The presented results confirm the good pointing performance of the detector as well as the expected angular resolution.
Report on the ASTERICS projects CORELib and ROAst
Authors: Bozza Cristiano , Pellegrino Carmelo , Stellacci Simona Maria , Spisso Bernardino
Published: May 2019

Two projects included in the OBELICS work package of the ASTERICS cluster will be described: CORELib and ROAst. CORELib is a collection of simulated showers induced by primary cosmic rays and a common framework to produce and manage such large production. CORELib provides high-statistics simulation for various astroparticle and astronomy experiments. The simulations are obtained by employing the widely used CORSIKA simulation framework. The parameters of simulations are available and easily accessible to the users. The goal of ROAst (ROot extension for Astronomy) is to extend the ROOT capabilities adding packages and tools for astrophysical research “bridging” the gap between particle physics and astronomy. The focus is on astronomical catalogues integration and on the support for astronomical coordinate transformations, manipulations as well as the graphical representation of astronomical regions of the sky.
Upper limit on the fraction of the cosmic ray flux from a separable source in the energy interval (1017 -1019 eV), estimated using data from the Yakutsk array
Authors: Ivanov Anatoly
Published: May 2019

Arrival directions of ultra-high energy cosmic rays (UHECRs) in the equatorial system, detected with the Yakutsk array in the energy range (1017 -10 19 eV), are re-analyzed using a new approximation for the zenith angle distribution of the event rate of extensive air showers (EAS). While the null hypothesis cannot be rejected based on the data used here, an upper limit on the fraction of cosmic rays from a separable source in the uniform background is derived as a function of declination and energy.
The cosmic ray energy spectrum measured with the new Tibet hybrid experiment
Authors: Amenomori M. , Bi X. J. , Chen D. , Chen T. L. , Chen W. Y. , Cui S. W. , Danzengluobu  , Ding L. K. , Feng C. F. , Feng Zhaoyang , Feng Z. Y. , Gou Q. B. , Guo Y. Q. , He H. H. , He Z. T. , Hibino K. , Hotta N. , Hu Haibing , Hu H. B. , Huang J. , Jia H. Y. , Jiang L. , Kajino F. , Kasahara K. , Katayose Y. , Kato C. , Kawata K. , Kozai M. , Labaciren  , Le G. M. , Li A. F. , Li H. J. , Li W. J. , Lin Y. H. , Liu C. , Liu J. S. , Liu M. Y. , Lu H. , Meng X. R. , Miyazaki T. , Munakata K. , Nakajima T. , Nakamura Y. , Nanjo H. , Nishizawa M. , Niwa T. , Ohnishi M. , Ohta I. , Ozawa S. , Qian X. L. , Qu X. B. , Saito T. , Saito T. Y. , Sakata M. , Sako T. K. , Shao J. , Shibata M. , Shiomi A. , Shirai T. , Sugimoto H. , Takita M. , Tan Y. H. , Tateyama N. , Torii S. , Tsuchiya H. , Udo S. , Wang H. , Wu H. R. , Xue L. , Yamamoto Y. , Yamauchi K. , Yang Z. , Yuan A. F. , Zhai L. M. , Zhang H. M. , Zhang J. L. , Zhang X. Y. , Zhang Y. , Zhang Yi , Zhang Ying , Zhaxisangzhu  , Zhou X. X.
Published: May 2019

We have upgraded the new Tibet ASgamma experiment in China since 2014 to measure the chemical composition of cosmic rays around the knee. This hybrid experiment consist of an air-shower-core detector array (YAC-II) to detect high energy electromagnetic component, the Tibet air-shower array (Tibet-III) and a large underground water-Cherenkov muon-detector array (MD). We have carried out a detailed air-shower Monte Carlo (MC) simulation to study the performance of the hybrid detectors by using CORSIKA (version 7.5000), which includes EPOS-LHC, QGSJETII-04, SIBYLL2.1 and SIBYLL2.3 hadronic interaction models. The preliminary results of the interaction model checking above 50 TeV energy region are reported in this paper, and the primary proton and helium spectra in the energy range 50 TeV to 1015 eV was derived from YAC-I data and is smoothly connected with direct observation data at lower energies and also with our previously reported works at higher energies within statistical errors. The knee of the (P+He) spectra is located around 400 TeV. The interaction model dependence in deriving the primary (P+He) spectra is found to be small (less than 25% in absolute intensity, 10% in position of the knee), and the composition model dependence is less than 10% in absolute intensity.
Highly-boosted dark matter and cutoff for cosmic-ray neutrinos through neutrino portal
Authors: Yin Wen
Published: May 2019

We study the cutoff for the cosmic-ray neutrino, set by the scattering with cosmic background neutrinos into dark sector particles through a neutrino portal interaction. We find that a large interaction rate is still viable, when the dark sector particles are mainly coupled to the τ-neutrino, so that the neutrino mean free path can be reduced to be O(10) Mpc over a wide energy range. If stable enough, the dark sector particle, into which most of the cosmic-ray neutrino energy is transferred, can travel across the Universe and reach the earth. The dark sector particle can carry the energy as large as O(EeV) if it originates from a cosmogenic neutrino.
Recent minimum-bias measurements by ATLAS
Authors: Wózniak Krzysztof W.
Published: May 2019

The Large Hadron Collider provides collisions of protons and nuclei at the highest energies available in the laboratory. A variety of recent results for minimum-bias pp, p+Pb and Pb+Pb collisions obtained by the ATLAS experiment is presented. For pp collisions they include the total and inelastic cross section, properties of minimum-bias events, underlying event characteristics and measurements of diffractive processes. The results for p+Pb and Pb+Pb collisions that are relevant for cosmic ray studies are also presented.
Study of contributions of diffractive processes to forward neutral particle production with the ATLAS-LHCf detector
Authors: Zhou Qi-Dong
Published: May 2019

LHCf is an experiment dedicated to verify the hadronic interaction models by measuring the forward neutral particle production at the LHC. Corresponding data are very important for understanding hadronic interactions occurring in air-shower development. According to the current LHCf results, no simulation model predicts the LHCf data perfectly. In order to provide more specific data, it is necessary to classify the LHCf observables into specific interaction types: diffraction or non-diffraction. Combining the information of ATLAS, LHCf is able to classify these specific interaction types experimentally. Especially, the ATLAS-LHCf joint experiment will have the unique sensitivity to low mass diffraction. LHCf and ATLAS have succeeded in the common data-taking in p-p collisions at √s = 13 TeV. We will report the first ATLAS-LHCf joint analysis result and discuss the impact of the corresponding joint analysis result to the determination of mass composition of ultra-high energy cosmic-rays.
Tests of hadronic interactions with measurements by Pierre Auger Observatory
Authors: Prado Raul R.
Published: May 2019

The hybrid design of the Pierre Auger Observatory allows for the measurement of a number of properties of extensive air showers initiated by ultra-high energy cosmic rays. By comparing these measurements to predictions from air shower simulations, it is possible to both infer the cosmic ray mass composition and test hadronic interactions beyond the energies reached by accelerators. In this paper, we will present a compilation of results of air shower measurements by the Pierre Auger Observatory which are sensitive to the properties of hadronic interactions and can be used to constrain the hadronic interaction models. The inconsistencies found between the interpretation of different observables with regard to primary composition and between their measurements and simulations show that none of the currently used hadronic interaction models can provide a proper description of air showers and, in particular, of the muon production.
Study of muons in extensive air showers from ultra-high energy cosmic rays measured with the Telescope Array experiment
Authors: Takeishi R.
Published: May 2019

The origin of ultra-high energy cosmic rays (UHECRs) has been a long-standing mystery. One of the uncertainties in UHECR observation derives from the hadronic interaction model used for air shower Monte-Carlo (MC) simulations. The number of muons observed at ground level from UHECR induced air showers is expected to depend upon the composition of primary cosmic rays. The MC prediction also depends on hadronic interaction models. One may test the hadronic interaction models by comparing the measured number of muons with the MC prediction. The Telescope Array (TA) is the largest experiment in the northern hemisphere observing UHECR in Utah, USA. It aims to reveal the origin of UHECR by studying the energy spectrum, mass composition and anisotropy of cosmic rays by utilizing an array of surface detectors (SDs) and fluorescence detectors. We studied muon densities in the UHE extensive air showers by analyzing the signal of TA SD stations for highly inclined showers which should have high muon purity. A high muon purity condition is imposed that requires the geometry of the shower and relative position of the given station and implies that muons dominate the signal. On condition that the muons contribute about 65% of the total signal, the number of particles from air showers is typically 1.88 ± 0.08(stat:) ± 0.42(syst:) times larger than the MC prediction with the QGSJET II-03 model for protons. The same feature was also obtained for other hadronic models, such as QGSJET II-04.
Some results from the Yakutsk array experiment and the status of the modernization program
Authors: Ivanov Anatoly
Published: May 2019

The Yakutsk array has been used to study cosmic rays since 1974. Charged particles such as electrons, positrons and muons are detected, as well as radio signals emitted by air showers. However, the characteristic shower component detected by the array is Cherenkov light. This article briefly reviews recent results from the Yakutsk array group.
EAS longitudinal development distribution parameters for different extrapolations of the nuclei intaraction cross section to the very high energy domain
Authors: Plebaniak Zbigniew , Wibig Tadeusz
Published: May 2019

Determination of the primary particle mass using air fluorescence or a Cherenkov detector array is one of the most difficult task of experimental cosmic ray studies. The information about the primary particle mass is a compound of the produced particle multiplicity, inelasticity, interaction cross-section and many other parameters, thus it is necessary to compare registered showers with sophisticated Monte-Carlo simulation results. In this work we present results of the studies of at least three possible ways of extrapolating proton- Nucleus and Nucleus-Nucleus cross sections to cosmic ray energies based on the Glauber theory. They are compared with experimental accelerator and cosmic ray data for the proton-air cross section. We also present results of the EAS development with the most popular high-energy interaction models adopted in the CORSIKA program with our cross section extrapolations. The average position of the shower maximum and the width of its distribution are compared with experimental data and some discussion is given.
JAM: an event generator for high energy nuclear collisions
Authors: Nara Yasushi
Published: May 2019

We review recent developments of an event generator JAM microscopic transport model to simulate high energy nuclear collisions, especially at high baryon density regions. Recent developments focus on the collective effects: implementation of nuclear potentials, equation of state (EoS) modified collision term, and dynamical integration of fluid dynamics. With these extensions, we can discuss the EoS dependence of the transverse collective flows.
Adiabatic expansion of nuclear matter gas to describe violation of Feynman scaling law in multiple particle production
Authors: Ohsawa Akinori , Shibuya Edison H. , Tamada Masanobu
Published: May 2019

The main features of the rapidity density distribution of the produced hadrons in multiple particle production in nucleon collisions are; (a) the distribution in the forward region (ȳ ≥ 0) has a shape similar to the Fermi distribution, (b) the distribution in the most forward region reaches almost the maximum rapidity ymax = ln(√s/M) (M : nucleon mass), and (c) the shrinkage of the distribution from the maximum rapidity increases with the incident energy (i.e. violation of Feynman scaling law). These features are possible to be described by the assumptions that; (1) a fireball of the gas (made of nuclear matter, with the temperature Ti and with the shape of the incident nucleon with Lorentz contraction) is produced in the collision, (2) the fireball makes the adiabatic expansion, and (3) the constituent particles of the gas obey the Maxwell-Boltzmann distribution of the temperature Tf in the final state.
Comparison of the Measurement and Simulation with KM2A Prototype Array
Authors: Li Zhe , Chen Songzhan , He Huihai , Li Cong , Lv Hongkui , Wang Yaping
Published: May 2019

The Large High Altitude Air Shower Observatory (LHAASO) is a new hybrid array for very high energy gamma ray astronomy and cosmic ray physics. The KM2A array, one of the main parts of LHAASO, covers an area of 1.3 km2 to observe gamma rays above 10 TeV up to 1 PeV for many sources. A prototype with 1% the size of the whole KM2A has been in stable operation for more than two years. A Monte Carlo simulation program named G4KM2A was developed; based on this work, the trigger rate, hit multiplicity, angular and core reconstruction are compared with KM2A prototype data. Finally, the moon shadow with -6.5 significance was obtained. The G4KM2A simulation results are consistent with KM2A prototype data and can be used for the whole KM2A array in future.
Air Shower Detection by Arrays of Radio Antennas
Authors: Schröder Frank G.
Published: May 2019

Antenna arrays are beginning to make important contributions to high energy astroparticle physics supported by recent progress in the radio technique for air showers. This article provides an update to my more extensive review published in Prog. Part. Nucl. Phys. 93 (2017) 1. It focuses on current and planned radio arrays for atmospheric particle cascades, and briefly references to a number of evolving prototype experiments in other media, such as ice. While becoming a standard technique for cosmic-ray nuclei today, in future radio detection may drive the field for all type of primary messengers at PeV and EeV energies, including photons and neutrinos. In cosmic-ray physics accuracy becomes increasingly important in addition to high statistics. Various antenna arrays have demonstrated that they can compete in accuracy for the arrival direction, energy and position of the shower maximum with traditional techniques. The combination of antennas and particles detectors in one array is a straightforward way to push the total accuracy for high-energy cosmic rays for low additional cost. In particular the combination of radio and muon detectors will not only enhance the accuracy for the cosmic-ray mass composition, but also increase the gamma-hadron separation and facilitate the search for PeV and EeV photons. Finally, the radio technique can be scaled to large areas providing the huge apertures needed for ultra-high-energy neutrino astronomy.
The Effects of Increasing Antenna Arrays for MIMO in Mine Tunnels
Authors: Nehme Ali , Hakem Nadir , Kandil Nahi
Published: May 2019

The aim of this paper is to prove theoretically by using waveguide and geometrical optical models that increasing MIMO array elements at the transmitter and receiver will have a limit on capacity where the equivalent spatial subchannels can be limited by the number of allowable modes.
Varizenchirurgie: Belastender als andere
Verfahren?
Authors: Brunig Guido , Buhr Johanna
Published: May 2019

Sämtliche in der Varizenchirurgie angewandten Verfahren beherbergen Risiken. Die
Risiken der klassischen operativen Sanierung der Varikosis mittels Stripping
sind in der Literatur sehr ausführlich beschrieben.

Bei den neueren therapeutischen Optionen, wie z. B. den endovenösen Therapien
oder der Schaumsklerosierung werden die möglichen Komplikationen erst in
jüngerer Zeit systematisch ausgewertet. Dementsprechend liegen derzeit im
Vergleich wenige Daten hierzu vor.

Betrachtet man die Lebensqualität des Patienten in den neuesten Vergleichsstudien
und Metaanalysen, zeigt sich, dass perioperativ kaum Unterschiede in der
Mobilität, Mortalität und Lebensqualität des Patienten bei den unterschiedlichen
Therapieverfahren bestehen [1].

Insgesamt ist davon auszugehen, dass die klassische operative Sanierung der
Varikosis mittels Crossektomie, Stripping und Miniphlebektomien im Vergleich zu
den endovenösen Therapieverfahren sowohl mit einem erhöhten Blutungsrisiko, also
auch mit einem erhöhten postoperativen Infektionsrisiko einhergeht.
Grundsätzlich ist das Blutungsrisiko, als auch das Infektionsrisiko jedoch auch
bei der Operation als niedrig einzuschätzen.

Das perioperative Nervenverletzungsrisiko scheint bei beiden Verfahren ähnlich
häufig zu sein, wobei repräsentative Daten aus Vergleichsstudien fehlen.

Das postoperative Thromboserisiko mit ggf. konsekutiver Lungenarterienembolie ist
unseres Erachtens nach bei den endovenösen Verfahren höher einzustufen als nach
einer klassischen operativen Sanierung der Varikosis.

Kosmetisch beeinträchtigende, postinflammatorische Hyperpigmentierungen im
OP-Gebiet treten häufiger nach endovenösen Therapieverfahren und nach
Sklerosierungstherapien auf.
Ablative Techniques for Image-Guided Thermal Ablation
Authors: Krokidis Miltiadis , Hatzidakis Adam
Published: May 2019

Percutaneous image-guided thermal ablation is an established form of treatment of small volume hepato-pancreatico-biliary (HPB) tumors with very satisfactory results over the last three decades. Purpose of this article is to offer a brief overview of the history of thermal ablation and the currently available technology that interventional radiologists have in their armamentarium to offer minimally invasive thermally for HPB cancer.
Broadband polarization-insensitive microwave-absorbing composite material based on carbon nanotube film metamaterial and ferrite
Authors: Yang ZhiHui , Che YongXing , Sun Xin , Zhang JiuLin , Tian JiangXiao , Yu HaiTao , Huang Qi
Published: May 2019

To meet the requirements of efficient broadband microwave-absorbing materials for a variety of technological equipment, a composite material based on a carbon nanotube (CNT) film metamaterial and ferrite is designed and fabricated in this study. To this end, available methods for the design and fabrication of the CNT film metamaterial are examined, and the optimal design of the CNT film metamaterial and a ferrite absorber is proposed. The broadband microwave-absorbing composite material was prepared by combining the CNT film with the ferrite absorber according to the design, and the microwave-absorbing properties of the composite material were studied. The results of experiments show that the reflectivity of the composite material was lower than −8 dB at 4–18 GHz at a bandwidth of 14 GHz, which is significantly better than the reflectivity obtained using a single ferrite absorber. Moreover, the composite material is insensitive to electromagnetic wave polarization.
Compact low-loss narrow-band duplexer using low-impedance open-loop resonators for K-band radiometers
Authors: Park Ju Seong , Min Seung Hyun , Kim Tae Gyu , Choi Hyun Chul , Kim Kang Wook
Published: May 2019

Design and implementation of a low-loss K-band duplexer consisting of two narrow bandpass filters with low-impedance open-loop resonators (OLRs) is presented. Narrow bandpass filters of 4%–7% bandwidth were often implemented with OLRs, but previous designs used OLRs mostly with 50 Ω linewidth. The design process was complicated due to multiple coupling mechanisms and multiple spurious response frequencies, often resulting in excessive insertion loss, especially at higher center frequencies. With the proposed design procedure for OLR filters, the values of the low-impedance line (less than 50 Ω) and proper coupling spacing are determined in the process of optimizing the filter performance, resulting in low insertion loss up to above K-band frequencies. The size of the proposed filter is also reduced to 64% of the conventional OLR filters. As an example of the proposed design method, a duplexer consisting of 4% narrow bandpass filters centered at 18.7 GHz and 22.5 GHz was implemented and measured, and the maximum insertion loss in each passband was 1.2 dB, which is much less than those of the previous design approaches.
Mechanical behavior of thin films due to in-plane tensile and fatigue loadings
Authors: Jen Ming Hwa R. , Wu Ying Hui , Liou Ting Yang
Published: May 2019

The mechanical properties, wrinkling phenomenon and fatigue response of polymeric polyethylene rectangular thin films due to both static tensile and cyclic tests were investigated. From the tensile tests we obtained the stress-strain curves and observed the formation of wrinkles for original films. The evolution of wrinkles resulted from in-plane to out-of-plane deformation and deflection. Also, the tensile tests for notched films were performed such as with a central hole, two vertical holes and two horizontal holes. From the fatigue tests the total strain vs. life curve was achieved. It was composed of two straight lines of both elastic and plastic parts.
Computational research on film cooling performance of different shaped holes with backward and forward injection
Authors: Zhao Zi-chen , He Li-ming , Dai Sheng-ji , Shao Shuai
Published: May 2019

The present work has been performed to evaluate the effect of three shaped holes (cylindrical hole, expansion-shaped hole and fan-shaped hole) with forward injection and backward injection on film cooling effectiveness on the adiabatic wall flat plate. All the cases are computed under eight blowing ratios (M) = [0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 1.75 and 2.0]. The results show that for film cooling hole structure with backward injection, a pair of rotating vortex is formed at the outlet of film cooling hole. Differing from the classical counter rotating vortex pair (CRVP) found in each hole with forward injection, the vortexes are expanded away from the test wall under the function of transverse main flow and are broken quickly. It indicates that the rotating vortex pair does not promote the mixing of main flow and jet flow. The uniformity of local film cooling effectiveness of the hole with backward injection is higher than that of the hole with forward injection. In terms of the spatially averaged film cooling effectiveness with a certain hole shape, the value under backward injection exceeds that under forward injection at a certain point: (1) M=0.5 for cylindrical hole, (2) M=0.75 for expansion-shaped hole and (3) M=1.25 for fan-shaped hole. The comparison of the calculation results of different holes with backward injection shows that in the case of high blowing ratio, a uniform distribution with higher film cooling effectiveness is easier to achieve with fan-shaped hole.
Development of a 3-D energy-momentum analyzer for meV-scale energy electrons
Authors: Karkare S. , Feng J. , Maxson J. , Padmore H. A.
Published: May 2019

In this article, we report on the development of a time-of-flight based electron energy analyzer capable of measuring the 3-D momentum and energy distributions of very low energy (millielectronvolt-scale) photoemitted electrons. This analyzer is capable for measuring energy and 3-D momentum distributions of electrons with energies down to 1 meV with a sub-millielectronvolt energy resolution. This analyzer is an ideal tool for studying photoemission processes very close to the photoemission threshold and also for studying the physics of photoemission based electron sources.
A microfocus x-ray computed tomography based gas hydrate triaxial testing apparatus
Authors: Li Yanghui , Wu Peng , Liu Weiguo , Sun Xiang , Cui Zhi , Song Yongchen
Published: May 2019

Gas hydrate-bearing sediment shows complex mechanical characteristics. Its macroscopic deformation process involves many microstructural changes such as phase transformation, grain transport, and cementation failure. However, the conventional gas hydrate triaxial testing apparatus is not possible to obtain the microstructure in the samples. In this study, a novel, low-temperature (−35 to 20 °C), high-pressure (>16 MPa confining pressure and >95.4 MPa vertical stress) triaxial testing apparatus suitable for X-ray computed tomography scanning is developed. The new apparatus permits time-lapse imaging to capture the role of hydrate saturation, effective stress, strain rate, hydrate decomposition on hydrate-bearing sediment characteristic, and cementation failure behavior. The apparatus capabilities are demonstrated using in situ generation of hydrate on a xenon hydrate-bearing glass bead sample. In the mentioned case, a consolidated drained shear test was conducted, and the imaging reveals hydrate occurrence with a saturation of 37.3% as well as the evolution of localized strain (or shear band) and cementation failure along with axial strain.
Remarkable charged particle dynamics near magnetic field null lines
Authors: Neishtadt Anatoly , Artemyev Anton , Turaev Dmitry
Published: May 2019

The study of charged-particle motion in electromagnetic fields is a rich source of problems, models, and new phenomena for nonlinear dynamics. The case of a strong magnetic field is well studied in the framework of a guiding center theory, which is based on conservation of an adiabatic invariant—the magnetic moment. This theory ceases to work near a line on which the magnetic field vanishes—the magnetic field null line. In this paper, we show that the existence of these lines leads to remarkable phenomena which are new both for nonlinear dynamics in general and for the theory of charged-particle motion. We consider the planar motion of a charged particle in a strong stationary perpendicular magnetic field with a null line and a strong electric field. We show that particle dynamics switch between a slow guiding center motion and the fast traverse along a segment of the magnetic field null line. This segment is the same (in the principal approximation) for all particles with the same total energy. During the phase of a guiding center motion, the magnetic moment of particle’s Larmor rotation stays approximately constant, i.e., it is an adiabatic invariant. However, upon each traversing of the null line, the magnetic moment changes in a random fashion, causing the particle to choose a new trajectory of the guiding center motion. This results in a stationary distribution of the magnetic moment, which only depends on the particle’s total energy. The jumps in the adiabatic invariant are described by Painlevé II equation.
UV-polarizing linear polyyne molecules aligned in PVA
Authors: Sata R. , Suzuki H. , Ueno N. , Morisawa Y. , Hatanaka M. , Wakabayashia T.
Published: May 2019

Electronic absorption bands of conjugated linear carbon chain molecules, namely polyynes H(C≡C)nH (n=5−7), are exploited to devise light-polarizing films applicable to the UV. Laser ablated polyynes are separated in size and dispersed in a film of polyvinyl alcohol (PVA), which is stretched to align the trapped linear polyyne molecules inside. As a nature of the structural anisotropy, transition dipole of the UV absorption for polyyne molecules is in parallel with the molecular axis and the absorption occurs only for the electromagnetic wave having the amplitude of its electric vector along the molecular axis. Aligned and fixed orientationally in the solid PVA film, polyyne molecules act as selective absorbers of one of the polarization components of incident light at particular wavelength. Using a light source of linearly polarized UV light, whose direction of polarization is rotatable, angular dependence of the absorption intensity is investigated for the stretched PVA film containing aligned polyyne molecules and analyzed in terms of an order parameter in the theory of linear dichroism.
Structure of the ligated Ag60 nanoparticle [{Cl@Ag12}@Ag48(dppm)12] (where dppm=bis(diphenylphosphino)methane)
Authors: Zavras Athanasios , Mravak Antonija , Bužančić Margarita , White Jonathan M. , Bonačić-Koutecký Vlasta , O’Hair Richard A. J.
Published: May 2019

A novel bisphosphine ligated Ag60 nanocluster, [{Cl@Ag12}@Ag48(dppm)12], has been discovered and characterized by X-ray crystallography. It consists of a central chloride located inside an icosahedral silver core layer, which is further encased by a second shell of 48 silver atoms/ions, which are capped with 12 bis(diphenylphosphino)methane (dppm) ligands. Due to lack of sufficient material the cluster could not be further characterized by other methods. DFT calculations were carried out on the cation [{Cl@Ag12}@Ag48(dppm)12]+ to determine if it corresponds to a superatom with a core count of n=58. The DFT optimized structure is in agreement with X-ray findings, but the low value of the HOMO-LUMO gap does not support superatom stability.