Studies of low-energy ionic collisions Final report, 1 Oct. 1965 - 30 Sep. 1967

Ionic-molecular collisions, and collision induced dissociation of ion

Reciprocal Trade Agreements: Impacts on Bilateral Trade Expansion and Contraction in the World Agricultural Marketplace

The rapid increase in the number of bilateral and regional free-trade agreements since 1995 is a striking development. The proliferation of these agreements has raised questions about whether they have, in fact, opened markets, created trade, promoted economic growth, and/or distorted trade. This study uses panel data from 1975 to 2005 and a gravity framework model to identify the influence of reciprocal trade agreements (RTAs) on bilateral trade in the world agricultural marketplace. A benchmark, Heckman sample-selection and two generalized models, one of which accounts for RTA phase-in effects, are used to gauge the impact on partner trade of mutual as well as asymmetric RTA membership. Empirical results show that RTAs increase agricultural trade between member countries but decrease trade between member and nonmember countries. Interestingly, RTAs were found to be particularly effective at expanding agricultural trade and opening markets in developing countries when developing- country trading partners are part of the same agreement.trade policy, reciprocal trade agreements, bilateral, regional, missing trade, gravity models, Agricultural and Food Policy, International Development, International Relations/Trade,

Economic costs and payoffs of bilateral/regional trade agreements

The rapid increase in the number of bilateral and regional free-trade agreements since 1995 is a striking development. The proliferation of these agreements has raised questions among academicians and policymakers about whether they have, in fact, opened markets, created trade, promoted economic growth, and/or distorted trade. This study uses panel data from the 1975-2005 period and the gravity framework to identify the influence of bilateral/regional free-trade agreements on bilateral trade in merchandise, agriculture, and clothing sectors. A benchmark, Heckman sample-selection, and two generalized models, one of which accounts for reciprocal-free-trade-agreement phase-in effects, are used to gauge the impact on partner trade of mutual as well as asymmetric RTA membership.trade policy, bilateral, regional, missing trade, gravity models, reciprocal trade agreements, Agricultural and Food Policy,

Characterization of radially symmetric finite time blowup in multidimensional aggregation equations,

This paper studies the transport of a mass $\mu$ in $\real^d, d \geq 2,$ by a flow field $v= -\nabla K*\mu$. We focus on kernels $K=|x|^\alpha/ \alpha$ for $2-d\leq \alpha<2$ for which the smooth densities are known to develop singularities in finite time. For this range This paper studies the transport of a mass $\mu$ in $\real^d, d \geq 2,$ by a flow field $v= -\nabla K*\mu$. We focus on kernels $K=|x|^\alpha/ \alpha$ for $2-d\leq \alpha<2$ for which the smooth densities are known to develop singularities in finite time. For this range we prove the existence for all time of radially symmetric measure solutions that are monotone decreasing as a function of the radius, thus allowing for continuation of the solution past the blowup time. The monotone constraint on the data is consistent with the typical blowup profiles observed in recent numerical studies of these singularities. We prove monotonicity is preserved for all time, even after blowup, in contrast to the case $\alpha >2$ where radially symmetric solutions are known to lose monotonicity. In the case of the Newtonian potential ($\alpha=2-d$), under the assumption of radial symmetry the equation can be transformed into the inviscid Burgers equation on a half line. This enables us to prove preservation of monotonicity using the classical theory of conservation laws. In the case $2 -d < \alpha < 2$ and at the critical exponent $p$ we exhibit initial data in $L^p$ for which the solution immediately develops a Dirac mass singularity. This extends recent work on the local ill-posedness of solutions at the critical exponent.Comment: 30 page

A Compact Formula for Rotations as Spin Matrix Polynomials

Group elements of SU(2) are expressed in closed form as finite polynomials of the Lie algebra generators, for all definite spin representations of the rotation group. The simple explicit result exhibits connections between group theory, combinatorics, and Fourier analysis, especially in the large spin limit. Salient intuitive features of the formula are illustrated and discussed

Reflectance spectra of mafic silicates and phyllosilicates from .6 to 4.6 microns

The results of spectral measurements for mafic silicates are given. The study provided valuable spectral reflectance information about mafic silicates and phyllosilicates in the 2.5 to 4.6 micron wavelength region. It was shown that the reflectance of these materials is strongly affected by the presence of H2O and OH. Therefore, the identification of these absorbing species is greatly enhanced

Ternary Virasoro - Witt Algebra

A 3-bracket variant of the Virasoro-Witt algebra is constructed through the use of su(1,1) enveloping algebra techniques. The Leibniz rules for 3-brackets acting on other 3-brackets in the algebra are discussed and verified in various situations.Comment: 6 pages, Late