Upgrading and testing program for narrow band high resolution planetary IR imaging spectrometer

An imaging spectrometer, intended primarily for observations of the outer planets, which utilizes an acoustically tuned optical filter (ATOF) and a charge coupled device (CCD) television camera was modified to improve spatial resolution and sensitivity. The upgraded instrument was a spatial resolving power of approximately 1 arc second, as defined by an f/7 beam at the CCD position and it has this resolution over the 50 arc second field of view. Less vignetting occurs and sensitivity is four times greater. The spectral resolution of 15 A over the wavelength interval 6500 A - 11,000 A is unchanged. Mechanical utility has been increased by the use of a honeycomb optical table, mechanically rigid yet adjustable optical component mounts, and a camera focus translation stage. The upgraded instrument was used to observe Venus and Saturn

Simplified method introduces drift fields into cells

Drift fields are simply introduced into solar cells at low temperatures in short periods. This is done after their rectifying junctions and output contacts are applied

Analysis of radiation damage in silicon solar cells and annealing or compensation of damage by impurities Final report, 7 Jan. 1964 - 21 Apr. 1966

Radiation damage in silicon solar cells and annealing or compensation of damage by impuritie

Symmetric Entrenchment: A Constitutional and Normative Theory

In this article, we defend the traditional rule that legislative entrenchment, the practice by which a legislature insulates ordinary statutes from repeal by a subsequent legislature, is both unconstitutional and normatively undesirable. A recent essay by Professors Eric Posner and Adrian Vermeule disputes this rule against legislative entrenchment and provides the occasion for our review of the issue. First, we argue that legislative entrenchment is unconstitutional, offering the first comprehensive defense of the proposition that the original meaning of the Constitution prohibits legislative entrenchments. We show that a combination of textual, historical, and structural arguments make a very compelling case against the constitutionality of legislative entrenchment. In particular, the Framers incorporated into the Constitution the traditional Anglo-American practice against legislative entrenchment, as evidenced by early comments by James Madison - comments that have not been previously discussed in this context. Moreover, legislative entrenchment essentially would allow Congress to use majority rule to pass constitutional amendments. On the normative issue, we offer a new theory of the appropriate scope of entrenchment: the theory of symmetric entrenchment. Under our theory, there is a strong presumption that only symmetric entrenchments - entrenchments that are enacted under the same supermajority rule that is needed to repeal them - are desirable. The presumption helps to distinguish desirable entrenchments that would improve upon government decisions from undesirable ones that simply involve legislatures protecting their existing preferences against future repeal. To be desirable entrenchments must generally be symmetric, because the supermajority rule that is applied to the enactment of entrenched measures would improve the quality of these measures and therefore compensate for the additional dangers that entrenchments pose. This theory steers a middle path between a strict majoritarian position, which would prohibit all legislative entrenchments, and a position that would allow legislative majorities to entrench measures

An Ultraluminous Supersoft X-ray Source in M81: An Intermediate-Mass Black Hole?

Ultraluminous supersoft X-ray sources (ULSSS) exhibit supersoft spectra with blackbody temperatures of 50-100 eV and bolometric luminosities above $10^{39}$ erg s$^{-1}$, and are possibly intermediate mass black holes (IMBHs) of $\ge10^3 M_\odot$ or massive white dwarfs that are progenitors of type Ia supernovae. In this letter we report our optical studies of such a source in M81, M81-ULS1, with HST archive observations. M81-ULS1 is identified with a point-like object, the spectral energy distribution of which reveals a blue component in addition to the companion of an AGB star. The blue component is consistent with the power-law as expected from the geometrically-thin accretion disk around an IMBH accretor, but inconsistent with the power-law as expected from the X-ray irradiated flared accretion disk around a white dwarf accretor. This result is strong evidence that M81-ULS1 is an IMBH instead of a white dwarf.Comment: 12 pages, 1 table, 3 figure

Obesity and other predictors of absenteeism in Philadelphia school children.

BACKGROUND: Limited data indicate that obese children are absent from school more than their normal-weight peers. We analyzed administrative data from a large urban school district to investigate the association of obesity and student sociodemographic characteristics with absenteeism. METHODS: We analyzed 291,040 records, representing 165,056 unique students (grades 1-12). Obesity status was classified according to Centers for Disease Control and Prevention age- and sex-specific percentiles for body mass index (BMI) and analyses were based on negative binomial regression. RESULTS: Overall rates of overweight and obesity were 17% and 20%, respectively, and the estimated absence rate was 17 absences per 180 student-days. Obesity was weakly associated with increased school absences. The association was present mainly among the most obese students (BMI \u3e99th percentile), who had an 11% greater absence rate compared to normal-weight students. Compared to white students, Hispanics and African Americans had higher absence rates (14% and 10%, respectively), and Asians had lower absence rates (43%). Students eligible for free or reduced-cost meals had 24% higher absence rates than those who were not eligible. CONCLUSIONS: Overweight and obesity do not seem strongly associated with school absence, except among extremely obese children. Race and poverty appear to affect absences to a greater extent than overweight and obesity. Additional research is needed to investigate the contribution of contextual factors in schools and neighborhoods. This study suggests that data routinely collected in schools could be used to track childhood obesity and to efficiently evaluate public health interventions designed to decrease childhood obesity