1,427 research outputs found
Mechanism of Electromigration Failure in Al Thin Film Interconnects Containing Sc
In order to understand the role of Sc on electromigration (EM) failure, Al interconnects with 0.1 and 0.3 wt.% Sc sere tested as a function of post-pattern annealing time. In response to the evolution of the line structure, the statistics of lifetime evolved. While the addition of Sc greatly reduces the rate of evolution of the failure statistics because the grain growth rate decreases, the MTF variation was found to be very similar to that of pure Al. These observations seem to show that Sc has little influence on the kinetics of Al EM; however, it has some influence on the EM resistance of the line since it is an efficient grain refiner. Unlike Cu in Al, Sc does not seem to migrate, which may explain its lack of influence on the kinetics of Al EM
Existence of Monetary Steady States in a Matching Model: Indivisible Money
Existence of a monetary steady state is established for a random matching model with divisible goods, indivisible money, and take-it-or-leave-it offers by consumers. There is no restriction on individual money holdings. The background environment is that in papers by Shi and by Trejos and Wright. The monetary steady state shown to exist has nice properties: the value function, defined on money holdings, is increasing and strictly concave, and the measure over money holdings has full support.
Unstable massive tau-neutrinos and primordial nucleosynthesis
The impact of unstable Majorana tau neutrinos on primordial nucleosynthesis
is considered. The mass and lifetime of nu_tau are taken in the intervals
0.1-20 MeV and 0.001-400 sec respectively. The studied decay modes are nu_tau
-> nu_mu + phi and nu_tau -> nu_e + phi, where phi is a massless (or light)
scalar. Integro-differential kinetic equations are solved numerically without
any simplifying assumptions. Our results deviate rather strongly from earlier
calculations. Depending on mass, lifetime, and decay channels of the nu_tau,
the number of effective neutrino species (found from He4), in addition to the 3
standard ones, varies from -2 to +2.5. The abundances of H2 and Li7 are also
calculated.Comment: 36 pages including 28 figures, minor change
Dynamic risk spillovers between gold, oil prices and conventional, sustainability and Islamic equity aggregates and sectors with portfolio implications
This paper investigates the time-varying equicorrelations and risk spillovers between crude oil, gold and the Dow Jones conventional, sustainability and Islamic stock index aggregates and 10 associated disaggregated Islamic sector stock indexes (basic materials, consumer services, consumer goods, energy, financials, health care, technology, industrials, telecommunications and utilities), using the multivariate DECO-FIAPARCH model and the spillover index of Diebold and Yilmaz (2012). We also conduct a risk management analysis at the sector level for commodity-Islamic stock sector index portfolios, using different risk exposure measures. For comparison purposes, we add the aggregate conventional Dow Jones global index and the Dow Jones sustainability world index. The results show evidence of time-varying risk spillovers between these markets. Moreover, there are increases in the correlations among the markets in the aftermath of the 2008–2009 GFC. Further, the oil, gold, energy, financial, technology and telecommunications sectors are net receivers of risk spillovers, while the sustainability and conventional aggregate DJIM indexes as well as the remaining Islamic stock sectors are net contributors of risk spillovers. Finally, we provide evidence that gold offers better portfolio diversification benefits and downside risk reductions than oil. © 2017 Elsevier B.V
Time and Amplitude of Afterpulse Measured with a Large Size Photomultiplier Tube
We have studied the afterpulse of a hemispherical photomultiplier tube for an
upcoming reactor neutrino experiment. The timing, the amplitude, and the rate
of the afterpulse for a 10 inch photomultiplier tube were measured with a 400
MHz FADC up to 16 \ms time window after the initial signal generated by an LED
light pulse. The time and amplitude correlation of the afterpulse shows several
distinctive groups. We describe the dependencies of the afterpulse on the
applied high voltage and the amplitude of the main light pulse. The present
data could shed light upon the general mechanism of the afterpulse.Comment: 11 figure
Dynamic characteristics of flow meters for fuel consumption measurement in ships
The dynamic characteristics of various flow meters for fuel
consumption measurement aboard shipswere evaluated. The
flow rate was measured using the Korea Research Institute of
Standards and Science (KRISS) oil flow standard system using
K-oil(density : 0.804 g/cm3, viscosity : 3.679 cSt), which has
similar fluid properties as diesel oil. The flow meters were tested
in a test bed that simulated the vibration conditions in ships. The
vibration conditions were established in accordance to vibration
standard IEC 60068-2-6 as follows: a±0.7g acceleration and 30
Hz frequency. The K-factors (mL/pulse) of various flow meters
(PD meter, turbine flow meter, Coriolis flow meter, and
ultrasonic flow meter) were obtained for various flow rates (60
L/h ~ 300 L/h). The PD meter, Coriolis flow meter, and
ultrasonic flow meter were found to have almost constant Kfactors
according to the flow rates. However, the K-factor of the
turbine flow meter was reduced at a low flow rate owing to
bearing friction in the turbine blade. The flow rate errors of the
PD meter, Coriolis flow meter, and ultrasonic flow meter were
found to be under ±0.5 % with and without vibration. However,
the flow rate error of the turbine flow meter was approximately
-4.3 % at a low flow rate (60 L/h) owing to the friction effect.
The Coriolis flow meter had the lowest flow rate error (< 0.1%)
according to the flow rate. The vibration influenced the flow rate
error of the Coriolis flow meter at high flow rates owing to its
measuring principle. However, the difference in flow rate errors
was a negligible value (0.05 %) with and without vibration.
Therefore, we confirmed that the PD meter, turbine meter,
Coriolis flow meter and ultrasonic flow meter could be used for
measuring flow rates in ships with a ±0.5 % flow rate error.Papers presented at the 13th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Portoroz, Slovenia on 17-19 July 2017 .International centre for heat and mass transfer.American society of thermal and fluids engineers
Neutron beam test of CsI crystal for dark matter search
We have studied the response of Tl-doped and Na-doped CsI crystals to nuclear
recoils and 's below 10 keV. The response of CsI crystals to nuclear
recoil was studied with mono-energetic neutrons produced by the
H(p,n)He reaction. This was compared to the response to Compton
electrons scattered by 662 keV -ray. Pulse shape discrimination between
the response to these 's and nuclear recoils was studied, and quality
factors were estimated. The quenching factors for nuclear recoils were derived
for both CsI(Na) and CsI(Tl) crystals.Comment: 21pages, 14figures, submitted to NIM
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