A sensitive far infrared detection system

An infrared field optics system was designed which achieves the maximum flux concentration allowed by the Abbe sine inequality and provides efficient coupling to bolometer-type detectors

The determination of cloud masses and dust characteristics from submillimetre thermal emission

The principles by which the dust and masses and total masses of interstellar clouds and certain characteristics of interstellar dust grains can be derived from observations of far infrared and submillimeter thermal emission are reviewed. To the extent possible, the discussion will be independent of particular grain models

Impact wave deposits provide new constraints on the location of the K/T boundary impact

All available evidence is consistent with an impact into oceanic crust terminating the Cretaceous Period. Although much of this evidence is incompatible with an endogenic origin, some investigators still feel that a volcanic origin is possible for the Cretaceous/Tertiary (K/T) boundary clay layers. The commonly cited evidence for a large impact stems from delicate clay layers and their components and the impact site has not yet been found. Impact sites have been suggested all over the globe. The impact is felt to have occurred near North America by: the occurrence of a 2 cm thick ejecta layer only at North American locales, the global variation of shocked quartz grain sizes peaking in North America, the global variation of spinel compositions with most refractory compositions occurring in samples from the Pacific region and possibly uniquely severe plant extinctions in the North American region. The K/T boundary interval was investigated as preserved on the banks of the Brazos River, Texas. The K/T fireball and ejecta layers with associated geochemical anomalies were found interbedded with this sequence which apparently allows a temporal resolution 4 orders of magnitude greater than typical K/T boundary sections. A literature search reveals that such coarse deposits are widely preserved at the K/T boundary. Impact wave deposits have not been found elsewhere on the globe, suggesting the impact occurred between North and South America. The coarse deposits preserved in Deep Sea Drilling Project (DSDP) holes 151-3 suggest the impact occurred nearby. Subsequent tectonism has complicated the picture

Observation of the Cosmic Ray Electron- Positron Ratio from 100 Mev to 3 Bev in 1964

Balloon flight data on cosmic ray electron- positron ratio from 100 MeV to 3 Be

Provenance of the K/T boundary layers

An array of chemical, physical and isotopic evidence indicates that an impact into oceanic crust terminated the Cretaceous Period. Approximately 1500 cu km of debris, dispersed by the impact fireball, fell out globally in marine and nonmarine environments producing a 2 to 4 mm thick layer (fireball layer). In North American locales, the fireball layer overlies a 15 to 25 mm thick layer of similar but distinct composition. This 15 to 25 mm layer (ejecta layer) may represent approximately 1000 cu km of lower energy ejecta from a nearby impact site. Isotopic and chemical evidence supports a mantle provenance for the bulk of the layers. The extraordinary REE pattern of the boundary clays was modelled as a mixture of oceanic crust, mantle, and approximately 10 percent continental material. The results are presented. If the siderophiles of the ejecta layer were derived solely from the mantle, a test may be available to see if the siderophile element anomaly of the fireball layer had an extraterrestrial origin. Radiogenic Os-187 is depleted in the mantle relative to an undifferentiated chondritic source. Os-187/Os-186 ratios of 1.049 and 1.108 were calculated for the ejecta and fireball layers, respectively

Detection of submillimeter polarization in the Orion Nebula

Linear polarization of the submillimeter (270 micron) continuum radiation from two regions of Orion was observed: one centered on the Kleinmann-Low Nebula and one centered on the 400 micron peak 1.5' south of the nebula. The polarizations measured for these regions are P = (1.7 +/-0.4)% at phi = 23 deg +/-7 deg and P=(1.7 +/- 0.5)% at phi = 27 deg +/- 7 deg respectively. A 2(sigma) upper limit, P or = 1.6%, was found for the nebular W3(OH). The position angle at KL is orthogonal to that measured at 11 microns by Dyck and Beichman and at 11 and 20 microns by Knacke and Capps. The far-IR values for KL reported by Gull et. al. (approx 2%) and by Cudlip et al. (1 to 2% level) are consistent with the submillimeter results

High-spatial-resolution CN and CS observation of two regions of massive star formation

Molecular line CN, CS and mm continuum observations of two intermediate- to high-mass star-forming regions - IRAS20293+3952 and IRAS19410+2336 - obtained with the Plateau de Bure Interferometer at high spatial resolution reveal interesting characteristics of the gas and dust emission. In spite of the expectation that the CN and CS morphology might closely follow the dense gas traced by the dust continuum, both molecules avoid the most central cores. Comparing the relative line strengths of various CN hyperfine components, this appears not to be an opacity effect but to be due to chemical and physical effects. The CN data also indicate enhanced emission toward the different molecular outflows in the region. Regarding CS, avoiding the central cores can be due to high optical depth, but the data also show that the CS emission is nearly always associated with the outflows of the region. Therefore, neither CS nor CN appear well suited for dense gas and disk studies in these two sources, and we recommend the use of different molecules for future massive disk studies. An analysis of the 1 and 3mm continuum fluxes toward IRAS20293+3952 reveals that the dust opacity index beta is lower than the canonical value of 2. Tentatively, we identify a decreasing gradient of beta from the edge of the core to the core center. This could be due to increasing optical depth toward the core center and/or grain growth within the densest cores and potential central disks. We detect 3mm continuum emission toward the collimated outflow emanating from IRAS20293+3952. The spectral index of alpha ~ 0.8 in this region is consistent with standard models for collimated ionized winds.Comment: 5 pages, 2 tables, 9 figures, accepted for Ap

Synchronous seasonal change in fin whale song in the North Pacific.

Fin whale (Balaenoptera physalus) song consists of down-swept pulses arranged into stereotypic sequences that can be characterized according to the interval between successive pulses. As in blue (B. musculus) and humpback whales (Megaptera novaeangliae), these song sequences may be geographically distinct and may correlate with population boundaries in some regions. We measured inter-pulse intervals of fin whale songs within year-round acoustic datasets collected between 2000 and 2006 in three regions of the eastern North Pacific: Southern California, the Bering Sea, and Hawaii. A distinctive song type that was recorded in all three regions is characterized by singlet and doublet inter-pulse intervals that increase seasonally, then annually reset to the same shorter intervals at the beginning of each season. This song type was recorded in the Bering Sea and off Southern California from September through May and off Hawaii from December through April, with the song interval generally synchronized across all monitoring locations. The broad geographic and seasonal occurrence of this particular fin whale song type may represent a single population broadly distributed throughout the eastern Pacific with no clear seasonal migratory pattern. Previous studies attempting to infer population structure of fin whales in the North Pacific using synchronous individual song samples have been unsuccessful, likely because they did not account for the seasonal lengthening in song intervals observed here

The Effects of Selected Tax Reform and School Finance Proposals on the Equalizing Tendencies of State Aid to Michigan Public School Districts

Problem. The purpose of this study was to determine the effects selected tax reform and school finance proposals would have on the equalizing tendencies of state aid to Michigan school districts. The study focused on nine finance revisions as follows: The Tisch proposal which would make 50 percent cuts in all real property values; the Siljander proposal which would make 60 percent cuts in the value of some classifications of real property; two variations of the Tisch and Siljander proposals which would specify even larger reductions in property values than the original proposals; two variations of the Siljander proposal which would place ceilings on the amount of eligible state aid; and three alternative proposals which would not affect property values but would call for slight dollar increases in the state aid guarantee formula and/or removal of any designated mill-ceiling on state aid. Data Collection, Methods, and Procedures. Data were collected for 530 school districts representing 99.8 percent of all public school students in grades K-12 in the State of Michigan for the 1977-78 school year. Included for each school district was the tax rate and local per-pupil revenues; the total number of pupils; the state equalized valuations (S.E.V.) per pupil for each political subdivision (township, village, city) within each school district; and the amount of per-pupil state aid (apportionment) paid to each school district. Additionally, the amount of assessed property values by property classification for each of 1,783 political subdivisions in the State of Michigan for 1977 was acquired. The data collected for school systems and the data concerning property valuations were combined to reflect the property classifications within each school district. Subsequently, a computer simulation was performed applying each of nine finance revision schemes to the 1977-78 data. The r4elationship between state equalized valuations of property and state aid per pupil was determined by computing a Person product-moment-correlation coefficient for the 1977-78 data and each of the nine proposals being investigated to determine equalizing tendencies. A test of the difference between correlation coefficients from two independent samples was performed to determine statistical significance of each analysis compared to 1977-78 data. A power analysis of each proposal was performed to determine effect size and practical significance. Major Findings. The Tisch and Siljander proposals would significantly reduce the equalizing effects of state aid to Michigan schools. Two variations of the Siljander proposal which specified a ceiling on the amount of eligible state aid were not significantly different from the 1977-78 finance method and could be substituted without changing the equalizing effects of state aid. At the same time, property tax reduction could be achieved. No improvement in the equalizing effects of state aid to Michigan schools would be realized by adoption of any of the nine finance revision plans analyzed. Conclusions. Plans to reduce property taxes and make up for lost revenues by state sources decrease the equalizing effects of state aid except that shifts away from the property tax to other revenues can be carried out without damage to equalization if there is a ceiling on the amount of state aid permitted to the local school district. It appears that the larger the reduction in assessed valuations, the more damage that is done insofar as equalizing effects of state aid are concerned when the state makes up for lost revenues. Slight increases in the amount of state aid guaranteed in an equal yield formula does not improve equalization. Removing the ceiling on the number of mills eligible for state aid in a guaranteed equal yield formula does not result in improved equalizing tendencies of state aid. The utilization of computer simulation is a valuable tool in decision making