Wind Powering America: A Key Influence on U.S. Wind Market (Fact Sheet)

This fact sheet summarizes an evaluation of the effectiveness of the Wind Powering America initiative conducted by an independent consultant funded by the U.S. Department of Energy

Synthesis of nitrogen heterocycles via transition metal catalyzed reductive cyclizations of nitroaromatics.

This research focuses on applying a catalyst system discovered in this laboratory, for the intermolecular allylic amination of alkenes with nitrobenzenes, to the synthesis of nitrogen heterocycles via an intramolecular reaction. The catalysts investigated in this study were of the general type [Cp(CO) 2M]2, where M = Fe or Ru. The use of these catalysts with CO pressure (50 atm) allows for the reductive cyclization of o-nitro styrenes to indoles and o-nitroenones to 4-quinolones in moderate to good yield. The reductive cyclization of the Baylis-Hillman adducts of 2-nitro benzaldehydes and acrylates were found to produce indoles and N-formyl indolines in poor yield, in marked contrast to previously reported cyclizations of these substrates with conventional nitro reductants. Functionalization of these o-nitro Baylis-Hillman adducts in a variety of ways led to the discovery that the Baylis-Hillman acetates produce quinolines selectively in good yields (47--67%) under somewhat mild conditions (7 atm CO, 150° C, 10 mol [Cp*(CO)2Fe]2, .011M substrate in dioxane, where Cp* = pentamethylcyclopentadienyl). Limited mechanistic studies (crossover experiments with a mixed Cp ligand dimer) implicate the possible involvement of 17 e-radicals from dissociation of the dimeric catalyst under our reaction conditions. It has also been found that 2-nitro ketoximes cyclize to 1H-indazoles under similar conditions in poor to good yield (26--85%)

"Supersolid" self-bound Bose condensates via laser-induced interatomic forces

We show that the dipole-dipole interatomic forces induced by a single off-resonant running laser beam can lead to a self-bound pencil-shaped Bose condensate, even if the laser beam is a plane-wave. For an appropriate laser intensity the ground state has a quasi-one dimensional density modulation --- a Bose "supersolid".Comment: 4 pages, 3 eps figure

Disks around Hot Stars in the Trifid Nebula

We report on mid-IR observations of the central region in the Trifid nebula, carried out with ISOCAM in several broad-band infrared filters and in the low resolution spectroscopic mode provided by the circular variable filter. Analysis of the emission indicates the presence of a hot dust component (500 to 1000 K) and a warm dust component at lower temperatures (150-200 K) around several members of the cluster exciting the HII region, and other stars undetected at optical wavelengths. Complementary VLA observations suggest that the mid-IR emission could arise from a dust cocoon or a circumstellar disk, evaporated under the ionization of the central source and the exciting star of the nebula. In several sources the $9.7\mu m$ silicate band is seen in emission. One young stellar source shows indications of crystalline silicates in the circumstellar dust.Comment: 4 pages with 1 figur

The effect of a strong external radiation field on protostellar envelopes in Orion

We discuss the effects of an enhanced interstellar radiation field (ISRF) on the observables of protostellar cores in the Orion cloud region. Dust radiative transfer is used to constrain the envelope physical structure by reproducing SCUBA 850 micron emission. Previously reported 13CO, C17O and H2CO line observations are reproduced through detailed Monte Carlo line radiative transfer models. It is found that the 13CO line emission is marginally optically thick and sensitive to the physical conditions in the outer envelope. An increased temperature in this region is needed in order to reproduce the 13CO line strengths and it is suggested to be caused by a strong heating from the exterior, corresponding to an ISRF in Orion 10^3 times stronger than the "standard" ISRF. The typical temperatures in the outer envelope are higher than the desorption temperature for CO. The C17O emission is less sensitive to this increased temperature but rather traces the bulk envelope material. The data are only fit by a model where CO is depleted, except in the inner and outermost regions where the temperature increases above 30-40 K. The fact that the temperatures do not drop below approximately 25 K in any of the envelopes whereas a significant fraction of CO is frozen-out suggest that the interstellar radiation field has changed through the evolution of the cores. The H2CO lines are successfully reproduced in the model of an increased ISRF with constant abundances of 3-5x10^{-10}.Comment: 11 pages, 10 figures. Accepted for publication in A&

A Rapidly Moving Shell in the Orion Nebula

A well-resolved elliptical shell in the inner Orion Nebula has been investigated by monochromatic imaging plus high- and low-resolution spectroscopy. We find that it is of low ionization and the two bright ends are moving at -39 and -49 km/s with respect to OMC-1. There is no central object, even in the infrared J bandpass although H2 emission indicates a possible association with the nearby very young pre-main-sequence star J&W 352, which is one of the youngest pre-main-sequence stars in the inner Orion Nebula. Many of the characteristics of this object (low ionization, blue shift) are like those of the Herbig-Haro objects, although the symmetric form would make it an unusual member of that class

The critical role of mass media in international norm diffusion: The case of UNDP human development reports

Data for the paper is available at https://ink.library.smu.edu.sg/soss_research/1919/</p

Mutual Coherence of Polarized Light in Disordered Media: Two-Frequency Method Extended

The paper addresses the two-point correlations of electromagnetic waves in general random, bi-anisotropic media whose constitutive tensors are complex Hermitian, positive- or negative-definite matrices. A simplified version of the two-frequency Wigner distribution (2f-WD) for polarized waves is introduced and the closed form Wigner-Moyal equation is derived from the Maxwell equations. In the weak-disorder regime with an arbitrarily varying background the two-frequency radiative transfer (2f-RT) equations for the associated $2\times 2$ coherence matrices are derived from the Wigner-Moyal equation by using the multiple scale expansion. In birefringent media, the coherence matrix becomes a scalar and the 2f-RT equations take the scalar form due to the absence of depolarization. A paraxial approximation is developed for spatialy anisotropic media. Examples of isotropic, chiral, uniaxial and gyrotropic media are discussed