Quasi-static vapor pressure measurements on reactive systems in inert atmosphere box

Apparatus makes vapor pressure measurements on air-sensitive systems in an inert atmosphere glove box. Once the apparatus is loaded with the sample and all connections made, all measuring operations may be performed outside the box. The apparatus is a single-tube adaptation of the double-tube quasi-static technique

Herschel-PACS imaging of protostars in the HH 1–2 outflow complex

We present 70 and 160 μm Herschel science demonstration images of a field in the Orion A molecular cloud that contains the prototypical Herbig-Haro objects HH 1 and 2, obtained with the Photodetector Array Camera and Spectrometer (PACS). These observations demonstrate Herschel’s unprecedented ability to study the rich population of protostars in the Orion molecular clouds at the wavelengths where they emit most of their luminosity. The four protostars previously identified by Spitzer 3.6–40 μm imaging and spectroscopy are detected in the 70 μm band, and three are clearly detected at 160 μm. We measure photometry of the protostars in the PACS bands and assemble their spectral energy distributions (SEDs) from 1 to 870 μm with these data, Spitzer spectra and photometry, 2MASS data, and APEX sub-mm data. The SEDs are fit to models generated with radiative transfer codes. From these fits we can constrain the fundamental properties of the protostars. We find luminosities in the range 12–84 L_⊙ and envelope densities spanning over two orders of magnitude. This implies that the four protostars have a wide range of envelope infall rates and evolutionary states: two have dense, infalling envelopes, while the other two have only residual envelopes. We also show the highly irregular and filamentary structure of the cold dust and gas surrounding the protostars as traced at 160 μm

Comparing Policies to Combat Emissions Leakage: Border Tax Adjustments versus Rebates

We explore conditions determining which anti-leakage policies might be more effective complements to domestic greenhouse gas emissions regulation. We consider four policies that could be combined with unilateral emissions pricing to counter effects on international competitiveness: a border tax on imports, a border rebate for exports, full border adjustment, and a domestic production rebate (as might be implemented with output-based allocation of emissions allowances). Each option faces different potential legal hurdles in international trade law; each also has different economic impacts. While all have the potential to support domestic production, none is necessarily effective at reducing global emissions. Nor is it possible to rank order the options. In each case, the effectiveness depends on the relative emissions rates, elasticities of substitution, and consumption volumes. We illustrate these results with simulations for the energy-intensive sectors of two different economies, the United States and Canada.environmental tax, rebate, border tax adjustment, emissions leakage, climate

A simple model of EMI-induced timing jitter in digital circuits, its statistical distribution and its effect on circuit performance

A simple model has been developed to characterize electromagnetic interference induced timing variations (jitter) in digital circuits. The model is based on measurable switching parameters of logic gates, and requires no knowledge of the internal workings of a device. It correctly predicts not only the dependence of jitter on the amplitude, modulation depth and frequency of the interfering signal, but also its statistical distribution. The model has been used to calculate the immunity level and bit error rate of a synchronous digital circuit subjected to radio frequency interference, and to compare the electromagnetic compatibility performance of fast and slow logic devices in such a circuit

Beyond density functional theory: the domestication of nonlocal potentials

Due to efficient scaling with electron number N, density functional theory (DFT) is widely used for studies of large molecules and solids. Restriction of an exact mean-field theory to local potential functions has recently been questioned. This review summarizes motivation for extending current DFT to include nonlocal one-electron potentials, and proposes methodology for implementation of the theory. The theoretical model, orbital functional theory (OFT), is shown to be exact in principle for the general N-electron problem. In practice it must depend on a parametrized correlation energy functional. Functionals are proposed suitable for short-range Coulomb-cusp correlation and for long-range polarization response correlation. A linearized variational cellular method (LVCM) is proposed as a common formalism for molecules and solids. Implementation of nonlocal potentials is reduced to independent calculations for each inequivalent atomic cell.Comment: Accepted for publication in Modern Physics Letters B (2004

The Single Audit Act: How Compliant Are Nonprofit Organizations?

Audits are an important legal accountability tool used by resource providers (donors, grantors, and others) to assure that resources are spent by nonprofit organizations in accordance with the resource providers intentions. This paper reports on audits that are required by the government of the United States for organizations receiving large amounts of federal financial assistance. Since 1990, nonprofits receiving substantial federal funds are required to undergo this rigorous and expensive form of federal oversight. We report on 11,841 nonprofit entities that underwent such audits, and the 3,592 audit firms that conducted them, from 1997 to 1999. Overall, compliance with federal regulations appears to be high. Our study indicates that smaller nonprofits, those that are new to government grants, and those with prior audit findings have a significantly higher rate of adverse audit findings. Perhaps for cost or other reasons, these nonprofits are being audited by less experienced auditors. Current federal funding does not provide any additional funds for Single Audit Act compliance. One policy implication of our work might be to provide federal funding specifically for Single Audit Act compliance to these nonprofits.This publication is Hauser Center Working Paper No. 16. The Hauser Center Working Paper Series was launched during the summer of 2000. The Series enables the Hauser Center to share with a broad audience important works-in-progress written by Hauser Center scholars and researchers

Do Social Networks Inspire Employment? - An Experimental Analysis -

There is robust field data showing that a frequent and successful way of looking for a job is via the intermediation of friends and relatives. Here we want to test this experimentally. Participants first play a simple public goods game with two interaction partners ('friends'), and share whatever they earn this way with two different sharing partners ('cousins') who have different friends. Thus one's social network contains two 'friends' and two 'cousins'. In the second phase of the experiment participants learn about a job opportunity for themselves and one additional vacancy and decide whom of their network they want to recommend and, if so, in which order. In case of coemployment, both employees compete for a bonus. Will one recommend others for the additional job in spite of this competition, will one prefer 'friends' or 'cousins' and how does this depend on contributions (of 'friends') or shared profits (with 'cousins')? Our findings are partly quite puzzling. Most participants, for instance, recommend quite actively but compete very fiercely for the bonus.

Measuring Operations: An Analysis of the Financial Statements of U.S. Private Colleges and Universities

As events in the business sector have highlighted, companies can play by the rules and yet produce misleading financial statements. This study examines the nongovernmental organizations that provide a substantial portion of higher education in the United States. We seek to determine whether private colleges and universities take advantage of the discretion available to them under accounting and auditing standards by presenting an operating measure in their statement of activities. We find that nearly 60 percent of schools report an operating measure but the items included or excluded from operations vary widely.This publication is Hauser Center Working Paper No. 17. The Hauser Center Working Paper Series was launched during the summer of 2000. The Series enables the Hauser Center to share with a broad audience important works-in-progress written by Hauser Center scholars and researchers

QCD on \alpha-Clusters

It is shown that the 21264 Alpha processor can reach about 20% sustained efficiency for the inversion of the Wilson-Dirac operator. Since fast ethernet is not sufficient to get balancing between computation and communication on reasonable lattice- and system-sizes, an interconnection using Myrinet is discussed. We find a price/performance ratio comparable with state-of-the-art SIMD-systems for lattice QCD.Comment: LATTICE99(machines), 3 page