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UV-C light processing of Cantaloupe melon juice: Evaluation of the impact on microbiological, and some quality characteristics, during refrigerated storage
摘要： UV-C light is a non-thermal technology with potential application in food industries. The objective was to assess UV-C radiation effect (13.44 W/m2) on microbiological decontamination and some quality characteristics of Cantaloupe melon juice, during refrigerated storage. Juice was inoculated with Listeria innocua (non-pathogenic surrogate of L. monocytogenes) and Alicyclobacillus acidoterrestris spores (spoilage indicators) used as indicators of the UV-C treatment efficacy. Total mesophylls and yeasts and molds were also enumerated. Results demonstrated that 5 minutes of exposure allowed 3.7– 0.3 log10 cycles reduction of L. innocua, while for A. acidoterrestris, 20 minutes were required to decrease 4.7– 0.1 log10 cycles. At the end of refrigerated storage for 13 days, UV-C treated juices retained color, total phenolics content and antioxidant activity, and yeast and molds did not grow. Since UV-C process was effective on microbial inactivation and allowed juice quality maintenance, it can be considered as a promising alternative to thermal pasteurization.
关键词： UV-C radiation,L. innocua,storage,melon juice,A. acidoterrestris
更新于2025-09-23 15:22:29
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Radiation tolerance characterization of Geiger-mode CMOS avalanche diodes for a dual-layer particle detector
摘要： An array of Single Photon Avalanche Diodes (SPAD), fabricated in a 180 nm CMOS technology featuring a high voltage (HV) option, has been investigated in terms of radiation tolerance, in view of the design of low material budget dual-tier detectors for charged particle tracking based on the coincidence of signals coming from pairs of vertically aligned pixels. Each pixel in the array includes both the processing electronics and the sensing element in a monolithic structure. The test vehicles were irradiated with 10 keV X-rays up to a dose of 1 Mrad (SiO2) and with neutrons up to a fluence of 1011 n_eq cm?2. A selection of the characterization results are presented together with the main features of a new large scale SPAD array to be fabricated in a 150 nm CMOS technology and ready for vertical interconnection in a dual layer structure.
关键词： Pixelated sensor,CMOS,Single Photon Avalanche Diode,Radiation tolerance,Tracking detectors
更新于2025-09-23 15:22:29
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Single photon detection with SiPMs irradiated up to 1014?cm?2 1-MeV-equivalent neutron fluence
摘要： Silicon photomultipliers (SiPM) are solid state light detectors with sensitivity to single photons. Their use in high energy physics experiments, and in particular in ring imaging Cherenkov (RICH) detectors, is hindered by their poor tolerance to radiation. At room temperature the large increase in dark count rate makes single photon detection practically impossible already at 1011 cm?2 1-MeV-equivalent neutron fluence. The neutron fluences foreseen by many subdetectors to be operated at the high luminosity LHC range up to 1014 cm?2 1-MeV-equivalent. In this paper we present the effects of such high neutron fluences on Hamamatsu and SensL SiPMs of different cell size. The advantage of annealing at high temperature (up to 175?C) is discussed. We demonstrate that, after annealing, operation at the single photon level with a SiPM irradiated up to 1014 cm?2 1-MeV-equivalent neutron fluence is possible at cryogenic temperature (77 K) with a dark count rate below 1 kHz.
关键词： Cryogenic temperature,Radiation damage,Single photon detection,SiPM,Neutron irradiation,Annealing
更新于2025-09-23 15:22:29
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An investigation on shielding properties of BaO, MoO3 and P2O5 based glasses using MCNPX code
摘要： In the present work, some radiation shielding quantities (mass attenuation coefficients, effective atomic number, effective electron density, half value layer and mean free path) for various BaO–MoO3–P2O5 ternary glass systems have been determined within the 0.015–15 MeV energy range, using WinXCom program. Additionally, the mass attenuation coefficients of all the investigated glasses have been calculated using MCNPX simulation code (version 2.6.0) and compared to those of WinXCom results. Among the studied glasses, BaMoP8 glass sample with MoO3 content of 70% mol is found to have superior gamma-ray shielding characteristics. Moreover, the glasses studied in this paper possess better radiation shielding properties by providing shorter half value layer (HVL) than RS-253 G18 commercial glass and some concrete samples namely ordinary, hematite-serpentine and ilmanite-limonite.
关键词： Attenuation coefficients,MCNPX,MoO3-based glass,WinXCom,Radiation shielding
更新于2025-09-23 15:22:29
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Proper horizontal photospheric flows in a filament channel
摘要： Context. An extended ?lament in the central part of the active region NOAA 11106 crossed the central meridian on Sept. 17, 2010 in the southern hemisphere. It has been observed in Hα with the THEMIS telescope in the Canary Islands and in 304 ? with the EUV imager (AIA) onboard the Solar Dynamic Observatory (SDO). Counterstreaming along the Hα threads and bright moving blobs (jets) along the 304 ? ?lament channel were observed during 10 h before the ?lament erupted at 17:03 UT. Aims. The aim of the paper is to understand the coupling between magnetic ?eld and convection in ?lament channels and relate the horizontal photospheric motions to the activity of the ?lament. Methods. An analysis of the proper photospheric motions using SDO/HMI continuum images with the new version of the coherent structure tracking (CST) algorithm developed to track granules, as well as the large scale photospheric ?ows, was performed for three hours. Using corks, we derived the passive scalar points and produced a map of the cork distribution in the ?lament channel. Averaging the velocity vectors in the southern hemisphere in each latitude in steps of 3.5 arcsec, we de?ned a pro?le of the di?erential rotation. Results. Supergranules are clearly identi?ed in the ?lament channel. Diverging ?ows inside the supergranules are similar in and out of the ?lament channel. Converging ?ows corresponding to the accumulation of corks are identi?ed well around the Hα ?lament feet and at the edges of the EUV ?lament channel. At these convergence points, the horizontal photospheric velocity may reach 1 km s?1, but with a mean velocity of 0.35 km s?1. In some locations, horizontal ?ows crossing the channel are detected, indicating eventually large scale vorticity. Conclusions. The coupling between convection and magnetic ?eld in the photosphere is relatively strong. The ?lament experienced the convection motions through its anchorage points with the photosphere, which are magnetized areas (ends, feet, lateral extensions of the EUV ?lament channel). From a large scale point-of-view, the di?erential rotation induced a shear of 0.1 km s?1 in the ?lament. From a small scale point-of-view, any convective motions favored the interaction of the parasitic polarities responsible for the anchorages of the ?lament to the photosphere with the surrounding network and may explain the activity of the ?lament.
关键词： prominences – Sun: photosphere – Sun: UV radiation – Sun: magnetic ?elds,Sun: ?laments
更新于2025-09-23 15:22:29
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Cross-correlation of cosmic far-infrared background anisotropies with large scale structures
摘要： We measure the cross-power spectra between luminous red galaxies (LRGs) from the Sloan Digital Sky Survey (SDSS)-III data release 8 (DR8) and cosmic infrared background (CIB) anisotropies from Planck and data from the Improved Reprocessing (IRIS) of the Infrared Astronomical Satellite (IRAS) at 353, 545, 857, and 3000 GHz, corresponding to 850, 550, 350 and 100 μm, respectively, in the multipole range 100 < l < 1000. Using approximately 6.5 × 10^5 photometrically determined LRGs in 7760 deg^2 of the northern hemisphere in the redshift range 0.45 < z < 0.65, we model the far-infrared background (FIRB) anisotropies with an extended version of the halo model. With these methods, we confirm the basic picture obtained from recent analyses of FIRB anisotropies with Herschel and Planck that the most efficient halo mass at hosting star forming galaxies is log(Meff/M☉) = 12.84 ± 0.15. We estimate the percentage of FIRB anisotropies correlated with LRGs as approximately 11.8%, 3.9%, 1.8%, and 1.0% of the total at 3000, 857, 545, and 353 GHz, respectively. At redshift z ～ 0.55, the bias of FIRB galaxies with respect to the dark matter density field has the value bFIRB ～ 1.45, and the mean dust temperature of FIRB galaxies is Td = 26 K. Finally, we discuss the impact of present and upcoming cross-correlations with far-infrared background anisotropies on the determination of the global star formation history and the link between galaxies and dark matter.
关键词： galaxies: statistics,large-scale structure of Universe,galaxies: evolution,cosmic background radiation,infrared: diffuse background
更新于2025-09-23 15:22:29
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First high-resolution look at the quiet Sun with ALMA at 3mm
摘要： We present an overview of high-resolution quiet Sun observations, from disk center to the limb, obtained with the Atacama Large millimeter and sub-millimeter Array (ALMA) at 3 mm. Seven quiet-Sun regions were observed at a resolution of up to 2.5'' by 4.5''. We produced both average and snapshot images by self-calibrating the ALMA visibilities and combining the interferometric images with full-disk solar images. The images show well the chromospheric network, which, based on the unique segregation method we used, is brighter than the average over the fields of view of the observed regions by ～305 K while the intranetwork is less bright by ～280 K, with a slight decrease of the network/intranetwork contrast toward the limb. At 3 mm the network is very similar to the 1600 ? images, with somewhat larger size. We detect, for the first time, spicular structures, rising up to 15'' above the limb with a width down to the image resolution and brightness temperature of ～1800 K above the local background. No trace of spicules, either in emission or absorption, is found on the disk. Our results highlight the potential of ALMA for the study of the quiet chromosphere.
关键词： Sun: chromosphere,Sun: radio radiation
更新于2025-09-23 15:22:29
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CPW-Fed Triple High Rejection Notched UWB & X-Band Antenna on Silicon for Imaging & Wireless Applications
摘要： In this paper, compact Coplanar Waveguide feed antenna covering UWB & X-Band signals (2.98GHz-13.34GHz) is presented. Antenna also offers triple notched band elimination (WiMAX: 3.40GHz-3.95GHz, WLAN: 4.50GHz-6.34GHz & Downlink Satellite System: 7.11GHz-7.802GHz) which are due to insertion of stub and etching of slots. Antenna is fabricated and characterized on silicon for imaging and wireless applications with having fractional bandwidth of 133%. The antenna offers gain, radiation efficiency and group delay between 3.26dBi-8.00dBi, 84%-92% and ≤ ±1.0ns respectively for the entire of its bandwidth. Isolation of antenna in face to face and side to side orientations are < -25dB with very less distortion presented in the transmission and reception of the signal. The radiations emitted by the antenna are observed as dipole like pattern in E-plane and omni-directional in H-plane.
关键词： radiation efficiency,Silicon,high rejection,fractional bandwidth,gain
更新于2025-09-23 15:22:29
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Testbeam and laboratory characterization of CMS 3D pixel sensors
摘要： The pixel detector is the innermost tracking device in CMS, reconstructing interaction vertices and charged particle trajectories. The sensors located in the innermost layers of the pixel detector must be upgraded for the ten-fold increase in luminosity expected at the High-Luminosity LHC (HL-LHC). As a possible replacement for planar sensors, 3D silicon technology is under consideration due to its good performance after high radiation fluence. In this paper, we report on pre- and post- irradiation measurements of CMS 3D pixel sensors with different electrode configurations from different vendors. The effects of irradiation on electrical properties, charge collection efficiency, and position resolution are discussed. Measurements of various test structures for monitoring the fabrication process and studying the bulk and surface properties of silicon sensors, such as MOS capacitors, planar and gate-controlled diodes are also presented.
关键词： Radiation-hard detectors,Si microstrip and pad detectors
更新于2025-09-23 15:22:29
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CONFINED FLARES IN SOLAR ACTIVE REGION 12192 FROM 2014 OCTOBER 18 TO 29
摘要： Using the observations from the Atmospheric Imaging Assembly and Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory, we investigate 6 X-class and 29 M-class ?ares occurring in solar active region (AR) 12192 from October 18 to 29. Among them, 30 (including 6 X- and 24 M-class) ?ares originated from the AR core, and the other 5 M-?ares appeared at the AR periphery. Four of the X-?ares exhibited similar ?aring structures, indicating they were homologous ?ares with an analogous triggering mechanism. The possible scenario is that photospheric motions of emerged magnetic ?uxes lead to shearing of the associated coronal magnetic ?eld, which then yields a tether-cutting favorable con?guration. Among the ?ve periphery M-?ares, four were associated with jet activities. The HMI vertical magnetic ?eld data show that the photospheric ?uxes of opposite magnetic polarities emerged, converged, and canceled with each other at the footpoints of the jets before the ?ares. Only one M-?are from the AR periphery was followed by a coronal mass ejection (CME). From October 20 to 26, the mean decay index of the horizontal background ?eld within the height range of 40–105 Mm is below the typical threshold for torus instability onset. This suggests that a strong con?nement from the overlying magnetic ?eld might be responsible for the poor CME production of AR 12192.
关键词： Sun: coronal mass ejections (CMEs),Sun: ?ares,Sun: activity,Sun: UV radiation
更新于2025-09-23 15:22:29