Effect of electron-phonon scattering on shot noise in nanoscale junctions

We investigate the effect of electron-phonon inelastic scattering on shot noise in nanoscale junctions in the regime of quasi-ballistic transport. We predict that when the local temperature of the junction is larger than its lowest vibrational mode energy $eV_c$, the inelastic contribution to shot noise (conductance) increases (decreases) with bias as $V$ ($\sqrt{V}$). The corresponding Fano factor thus increases as $\sqrt{V}$. We also show that the inelastic contribution to the Fano factor saturates with increasing thermal current exchanged between the junction and the bulk electrodes to a value which, for $V>>V_c$, is independent of bias. A measurement of shot noise may thus provide information about the local temperature and heat dissipation in nanoscale conductors.Comment: 4 pages, 2 figure

Modeling the Effect of Oil Price on Global Fertilizer Prices

The main purpose of this paper is to evaluate the effect of crude oil price on global fertilizer prices in both the mean and volatility. The endogenous structural breakpoint unit root test, the autoregressive distributed lag (ARDL) model, and alternative volatility models, including the generalized autoregressive conditional heteroskedasticity (GARCH) model, Exponential GARCH (EGARCH) model, and GJR model, are used to investigate the relationship between crude oil price and six global fertilizer prices. Weekly data for 2003-2008 for the seven price series are analyzed. The empirical results from ARDL show that most fertilizer prices are significantly affected by the crude oil price, which explains why global fertilizer prices reached a peak in 2008. We also find that that the volatility of global fertilizer prices and crude oil price from March to December 2008 are higher than in other periods, and that the peak crude oil price caused greater volatility in the crude oil price and global fertilizer prices. As volatility invokes financial risk, the relationship between oil price and global fertilizer prices and their associated volatility is important for public policy relating to the development of optimal energy use, global agricultural production, and financial integration.volatility;crude oil price;global fertilizer price;non-renewable fertilizers;structural breakpoint unit root test

An Economy-wide Analysis of Impacts of WTO Tiered Formula for Tariff Reduction on Taiwan

In this study we use Taiwan as a case study to provide an economy-wide analysis of impacts on Taiwan of WTO tariff reduction schemes with different combinations of thresholds and reduction rates. The model we utilized in this study is Taiwan General Equilibrium Model with a WTO module (TAIGEM-WTO, hereafter) that is a multi-sectoral computable general equilibrium (CGE) model of the Taiwan's economy derived from Australian ORANI model (Dixon, Parmenter, Sutton and Vincent, 1982). Simulation results show that results are more sensitive to the scheme of tariff-reduction (i.e., Category 1, 2, and 3) than the tiered levels (i.e., A, B, C, and D) and as a strategy we should pay more attention to the arguments related to the amounts of tariff-reduction. Moreover, changes in nominal average tariff rates are more sensitive and shocks to the economy are more severe when we change the tariff reduction categories rather than the tiered levels. This conclusion also applies to the tiered reduction case when only sensitive products are considered. Finally, simulations with sector's bound rate calculated using arithmetic means have bigger effects than those using import values as weights. Therefore, sector's bound rate using import values as weights would be preferred.Computable General Equilibrium (CGE), Tiered Formula, WTO, International Relations/Trade,

AN INVESTIGATION OF SOCCER BALL VELOCITY ON INSTEP KICK WITH AND WITHOUT ARM SWAYING

Many biomechanical researches of soccer try to understand the kinematic and kinetic effects of kicking; the most widely concerned is maximal force instep kick (powerful instep kick). Kellis and Katis (2008) reported that the ball velocity in instep kick on related researches were surpass in 72 Km/h (20m/s), and the highest was 115.6 Km/h (32.1 m/s). The higher ball speed, the lower time a keeper react. The kicking skills are complicated, and multiple factors must be measured. Not only lower limbs involve on kicking task, but also upper body affects the kicking performance. Kicking with arm swaying is a common motion in goal kick, directly free kick, penalty kick, and instep kick. The arm (non-kicking side) begins to sway when a player run-up to kick a ball at the last step and it may provide more strength to kick a ball. Arm swaying motion also applies in other sports. It advances the jumping performances in standing long jump due to maintaining balance and increasing the velocity of the body’s center of gravity (Ashby & Heegaard, 2002). The muscle pre-lengthening and stretch by arm swaying increased the strength of kicking; skilled soccer players had significantly larger knee flexion-extension movement (Shan and Westerhoff, 2005). The range of motion (ROM) of knee and the foot segment velocity are the important parameter for understanding the skill of players. The distance between right ankle and left ankle (while the support-foot landing) was measure to understand the hip and body stretch, and this distance affect the time of acting force for kicking the ball. To improve the ball velocity on kicking, the purpose of this study was to compare the ball velocity and kinematic data on different motions of arm. The motions were arm swaying and arm fixed (without arm swaying) while kicking the ball. The results were a useful reference for soccer players and instructors

On a class of reductions of Manakov-Santini hierarchy connected with the interpolating system

Using Lax-Sato formulation of Manakov-Santini hierarchy, we introduce a class of reductions, such that zero order reduction of this class corresponds to dKP hierarchy, and the first order reduction gives the hierarchy associated with the interpolating system introduced by Dunajski. We present Lax-Sato form of reduced hierarchy for the interpolating system and also for the reduction of arbitrary order. Similar to dKP hierarchy, Lax-Sato equations for $L$ (Lax fuction) due to the reduction split from Lax-Sato equations for $M$ (Orlov function), and the reduced hierarchy for arbitrary order of reduction is defined by Lax-Sato equations for $L$ only. Characterization of the class of reductions in terms of the dressing data is given. We also consider a waterbag reduction of the interpolating system hierarchy, which defines (1+1)-dimensional systems of hydrodynamic type.Comment: 15 pages, revised and extended, characterization of the class of reductions in terms of the dressing data is give