http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Performance of a Dual Layer Silicon Charge Detector During CREAM Balloon Flight
Nam, S.,Ahn, H. S.,Allison, P.,Bagliesi, M. G.,Barbier, L.,Beatty, J. J.,Bigongiari, G.,Brandt, T. J.,Jeon, J. A.,Childers, J. T.,Conklin, N. B.,Coutu, S.,DuVernois, M. A.,Ganel, O.,Han, J. H.,Kim, K. IEEE 2007 IEEE transactions on nuclear science Vol.54 No.5
<P>The balloon-borne cosmic-ray experiment CREAM (Cosmic Ray Energetics And Mass) has completed two flights in Antarctica, with a combined duration of 70 days. One of the detectors in the payload is the SCD (silicon charge detector) that measures the charge of high energy cosmic rays. The SCD was assembled with silicon sensors. A sensor is a 4 × 4 array of DC-coupled PIN diode pixels with the total active area of 21 × 16 mm<SUP>2</SUP>. The SCD used during the first flight (December 2004-January 2005) was a single layer device, then upgraded to a dual layer device for the second flight (December 2005-January 2006), covering the total sensitive area of 779 × 795 mm<SUP>2</SUP>. Flight data demonstrated that adding a second layer improved SCD performance, showing excellent particle charge resolution. With a total dissipation of 136 W for the dual layer system, special care was needed in designing thermal paths to keep the detector temperature within its operational range. As a consequence, flight temperatures of the SCD, even at diurnal maximum were kept below 38°C. The SCD mechanical structure was designed to minimize the possibility of damage to the sensors and electronics from the impacts of parachute deployment and landing. The detector was recovered successfully following the flight and is being refurbished for the next flight in 2007. Details of construction, operation, and performance are presented for the dual-layered SCD flown for the second CREAM flight.</P>
Liu, Ce Feng,Brandt, Gabriel S.,Hoang, Quyen Q.,Naumova, Natalia,Lazarevic, Vanja,Hwang, Eun Sook,Dekker, Job,Glimcher, Laurie H.,Ringe, Dagmar,Petsko, Gregory A. National Academy of Sciences 2016 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.113 No.43
<P>The transcription factor T-bet (Tbox protein expressed in T cells) is one of the master regulators of both the innate and adaptive immune responses. It plays a central role in T-cell lineage commitment, where it controls the T(H)1 response, and in gene regulation in plasma B-cells and dendritic cells. T-bet is a member of the Tbox family of transcription factors; however, T-bet coordinately regulates the expression of many more genes than other Tbox proteins. A central unresolved question is how T-bet is able to simultaneously recognize distant Tbox binding sites, which may be located thousands of base pairs away. We have determined the crystal structure of the Tbox DNA binding domain (DBD) of T-bet in complex with a palindromic DNA. The structure shows a quaternary structure in which the T-bet dimer has its DNA binding regions splayed far apart, making it impossible for a single dimer to bind both sites of the DNA palindrome. In contrast to most other Tbox proteins, a single T-bet DBD dimer binds simultaneously to identical half-sites on two independent DNA. A fluorescence-based assay confirms that T-bet dimers are able to bring two independent DNA molecules into close juxtaposition. Furthermore, chromosome conformation capture assays confirm that T-bet functions in the direct formation of chromatin loops in vitro and in vivo. The data are consistent with a looping/synapsing model for transcriptional regulation by T-bet in which a single dimer of the transcription factor can recognize and coalesce distinct genetic elements, either a promoter plus a distant regulatory element, or promoters on two different genes.</P>
Reliability over time of wind turbines steel towers subjected to fatigue
Emilio A. Berny-Brandt,Sonia E. Ruiz 한국풍공학회 2016 Wind and Structures, An International Journal (WAS Vol.23 No.1
A probabilistic approach that combines structural demand hazard analysis with cumulative damage assessment is presented and applied to a steel tower of a wind turbine. The study presents the step by step procedure to compare the reliability over time of the structure subjected to fatigue, assuming: a) a binomial Weibull annual wind speed, and b) a traditional Weibull probability distribution function (PDF). The probabilistic analysis involves the calculation of force time simulated histories, fatigue analysis at the steel tower base, wind hazard curves and structural fragility curves. Differences in the structural reliability over time depending on the wind speed PDF assumed are found, and recommendations about selecting a real PDF are given.
Reliability over time of wind turbines steel towers subjected to fatigue
Berny-Brandt, Emilio A.,Ruiz, Sonia E. Techno-Press 2016 Wind and Structures, An International Journal (WAS Vol.23 No.1
A probabilistic approach that combines structural demand hazard analysis with cumulative damage assessment is presented and applied to a steel tower of a wind turbine. The study presents the step by step procedure to compare the reliability over time of the structure subjected to fatigue, assuming: a) a binomial Weibull annual wind speed, and b) a traditional Weibull probability distribution function (PDF). The probabilistic analysis involves the calculation of force time simulated histories, fatigue analysis at the steel tower base, wind hazard curves and structural fragility curves. Differences in the structural reliability over time depending on the wind speed PDF assumed are found, and recommendations about selecting a real PDF are given.
Chang, Y.-Y.,Chen, C.R.,Chen, P.,Huang, J.-J.,Huang, M.A.,Liu, T.-C.,Nam, J.W.,Wang, M.-Z.,Bogomolov, V.,Brandt, S.,Budtz-Jørgensen, C.,Castro-Tirado, A.J.,Choi, H.S.,Connell, P.H.,Eyles, C.,Jeong, S. Elsevier 2015 Nuclear Instruments & Methods in Physics Research. Vol.771 No.-
<P><B>Abstract</B></P> <P>In this paper we present the Inverted-Conical light guide designed for optical crosstalk reduction in the scintillator-MAPMT assemblies. The research was motivated by the 30% crosstalk observed in <I>UFFO</I> X-ray telescope, <I>UBAT</I>, during the preliminary calibration with MAPMTs of 64 2.88 × 2.88 mm<SUP>2</SUP> pixels and identically gridded YSO crystal matrices. We began the study with the energy and crosstalk calibrations of the detector, then we constructed a GEANT4 simulation with the customized metallic film model as the MAPMT photocathode. The simulation reproduced more than 70% of the crosstalk and explained it as a consequence of the total reflection produced by the photocathode. The result indicated that the crosstalk mechanism could be a common case in most of the contact-assembled scintillation detectors. The concept of the Inverted-Conical light guide was to suppress the total reflection by contracting the incident angle of the scintillation. We optimized the design in the simulation and fabricated a test sample. The test sample reduced 52% crosstalk with a loss of 6% signal yield. The idea of the Inverted-Conical light guide can be adapted by scintillation detectors multi-pixel, imaging-purpose scintillation detectors such as the ultra-fast GRB observatory <I>UFFO-UBAT</I>, whose performances are sensitive to responding time, image resolution, and geometrical modifications.</P>
MEASUREMENTS OF THE RELATIVE ABUNDANCES OF HIGH-ENERGY COSMIC-RAY NUCLEI IN THE TeV/NUCLEON REGION
Ahn, H. S.,Allison, P. S.,Bagliesi, M. G.,Barbier, L.,Beatty, J. J.,Bigongiari, G.,Brandt, T. J.,Childers, J. T.,Conklin, N. B.,Coutu, S.,DuVernois, M. A.,Ganel, O.,Han, J. H.,Jeon, J. A.,Kim, K. C.,L IOP Publishing 2010 The Astrophysical journal Vol.715 No.2
<P>We present measurements of the relative abundances of cosmic-ray nuclei in the energy range of 500-3980 GeV/nucleon from the second flight of the Cosmic Ray Energetics And Mass balloon-borne experiment. Particle energy was determined using a sampling tungsten/scintillating-fiber calorimeter, while particle charge was identified precisely with a dual-layer silicon charge detector installed for this flight. The resulting element ratios C/O, N/O, Ne/O, Mg/O, Si/O, and Fe/O at the top of atmosphere are 0.919 +/- 0.123(stat) +/- 0.030(syst), 0.076 +/- 0.019(stat) +/- 0.013(syst), 0.115 +/- 0.031(stat) +/- 0.004(syst), 0.153 +/- 0.039(stat) +/- 0.005(syst), 0.180 +/- 0.045(stat) +/- 0.006(syst), and 0.139 +/- 0.043(stat) +/- 0.005(syst), respectively, which agree with measurements at lower energies. The source abundance of N/O is found to be 0.054 +/- 0.013(stat) +/- 0.009(-0.017)(syst+0.010esc). The cosmic-ray source abundances are compared to local Galactic (LG) abundances as a function of first ionization potential and as a function of condensation temperature. At high energies the trend that the cosmic-ray source abundances at large ionization potential or low condensation temperature are suppressed compared to their LG abundances continues. Therefore, the injection mechanism must be the same at TeV/nucleon energies as at the lower energies measured by HEAO-3, CRN, and TRACER. Furthermore, the cosmic-ray source abundances are compared to a mixture of 80% solar system abundances and 20% massive stellar outflow (MSO) as a function of atomic mass. The good agreement with TIGER measurements at lower energies confirms the existence of a substantial fraction of MSO material required in the similar to TeV per nucleon region.</P>
Sol-gel based TiO2 paste applied in screen-printed dye-sensitized solar cells and modules
Mateja Hocˇevar,Ursˇa Opara Krasˇovec,Matevzˇ Bokalic,Marko Topic,Welmoed Veurman,Henning Brandt,Andreas Hinsch 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.5
A simple manufacturing process based on screen-printing is crucial for a successful commercialization of dye-sensitized solar cells (DSSCs). We developed the sol–gel based TiO2 paste in such a way that solely a single step deposition is sufficient to realize a sponge-like structure of the layer assuring its high activity in DSSCs. For the first time the sol–gel based TiO2 paste was screen printed and tested in DSSC masterplates and PV mini-modules. Electroluminescence imaging of the mini-module proved layer homogeneity and no manufacturing defects. The conversion efficiency of the PV mini-module with the active area of 75 cm2 reaches 5.7% at STC.
Recent developments in G<small>EANT</small>4
Allison, J.,Amako, K.,Apostolakis, J.,Arce, P.,Asai, M.,Aso, T.,Bagli, E.,Bagulya, A.,Banerjee, S.,Barrand, G.,Beck, B.R.,Bogdanov, A.G.,Brandt, D.,Brown, J.M.C.,Burkhardt, H.,Canal, Ph.,Cano-Ott, D. Elsevier 2016 Nuclear Instruments & Methods in Physics Research. Vol.835 No.-
<P><B>Abstract</B></P> <P>G<SMALL>EANT</SMALL>4 is a software toolkit for the simulation of the passage of particles through matter. It is used by a large number of experiments and projects in a variety of application domains, including high energy physics, astrophysics and space science, medical physics and radiation protection. Over the past several years, major changes have been made to the toolkit in order to accommodate the needs of these user communities, and to efficiently exploit the growth of computing power made available by advances in technology. The adaptation of G<SMALL>EANT</SMALL>4 to multithreading, advances in physics, detector modeling and visualization, extensions to the toolkit, including biasing and reverse Monte Carlo, and tools for physics and release validation are discussed here.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Multithreading resulted in a smaller memory footprint and nearly linear speed-up. </LI> <LI> Scoring options, faster geometry primitives, more versatile visualization were added. </LI> <LI> Improved electromagnetic and hadronic models and cross sections were developed. </LI> <LI> Reverse Monte Carlo and general biasing methods were added. </LI> <LI> Physics validation efforts were expanded and new validation tools were added. </LI> </UL> </P>
THE UFFO SLEWING MIRROR TELESCOPE FOR EARLY OPTICAL OBSERVATION FROM GAMMA RAY BURSTS
NAM, JIWOO,AHMAD, S.,AHN, K.,BARRILLON, P.,BRANDT, S.,BUDTZ-JØRGENSEN, C.,CASTRO-TIRADO, A. J.,CHANG, S.-H.,CHEN, C.-R.,CHEN, P.,CHOI, Y. J.,CONNELL, P.,DAGORET-CAMPAGNE, S.,EYLES, C.,GROSSAN, B.,HUAN World Scientific 2013 Modern physics letters A Vol.28 No.2
<P> While some space born observatories, such as SWIFT and FERMI, have been operating, early observation of optical after grow of GRBs is still remained as an unexplored region. The Ultra-Fast Flash Observatory (UFFO) project is a space observatory for optical follow-ups of GRBs, aiming to explore the first 60 seconds of GRBs optical emission. Using fast moving mirrors to redirect our optical path rather than slewing the entire spacecraft, UFFO is utilized to catch early optical emissions from GRB within 1 sec. We have developed the UFFO Pathfinder Telescope which is going to be on board of the Lomonosov satellite and launched in middle of 2012. We will discuss about scientific potentials of the UFFO project and present the payload development status, especially for Slewing Mirror Telescope which is the key instrument of the UFFO-pathfinder mission. </P>