High resolution images of P/Tempel 1 and P/Tempel 2 constructed from IRAS survey data

Infrared images of P/Tempel 1 and P/Tempel 2 were constructed from IRAS survey data using a computer algorithm based on the Maximum Correlation Method for Image Construction (Aumann et al, 1990). The resulting images are of sufficiently high quality and resolution to delineate coma and tail morphology, and permit accurate photometry of the total dust complex. Comparisons of the infrared colors and photometric profiles of Tempel 1 and Tempel 2 at similar heliocentric distances show that the grains produced by the two comets are quite similar in radiometric and dynamic properties. Tempel 1 is found to produce about 30 percent more dust in its coma and tail than Tempel 2. The comae of Tempel 1 and Tempel 2 are expanding with mean velocities of 5.8 plus or minus 0.07 and 6.1 plus or minus 0.17 m/sec respectively, indicative of the ejection of large grains. The IRAS cataloged infrared fluxes (Walker, 1986) are found to be underestimated by as much as a factor of three for the comets. Therefore, it is essential to create images of the comets to obtain meaningful IRAS photometry

An atlas of selected calibrated stellar spectra

Five hundred and fifty six stars in the IRAS PSC-2 that are suitable for stellar radiometric standards and are brighter than 1 Jy at 25 microns were identified. In addition, 123 stars that meet all of our criteria for calibration standards, but which lack a luminosity class were identified. An approach to absolute stellar calibration of broadband infrared filters based upon new models of Vega and Sirius due to Kurucz (1992) is presented. A general technique used to assemble continuous wide-band calibrated infrared spectra is described and an absolutely calibrated 1-35 micron spectrum of alpha(Tau) is constructed and the method using new and carefully designed observations is independently validated. The absolute calibration of the IRAS Low Resolution Spectrometer (LRS) database is investigated by comparing the observed spectrum of alpha(Tau) with that assumed in the original LRS calibration scheme. Neglect of the SiO fundamental band in alpha(Tau) has led to the presence of a specious 'emission' feature in all LRS spectra near 8.5 microns, and to an incorrect spectral slope between 8 and 12 microns. Finally, some of the properties of asteroids that effect their utility as calibration objects for the middle and far infrared region are examined. A technique to determine, from IRAS multiwaveband observations, the basic physical parameters needed by various asteroid thermal models that minimize the number of assumptions required is developed

Candidates for asteroid dust trails

The contribution of different sources to the circumsolar dust cloud (known as the zodiacal cloud) can be deduced from diagnostic observations. We used the Spitzer Space Telescope to observe the diffuse thermal emission of the zodiacal cloud near the ecliptic. Several structures were identified in these observations, including previously known asteroid dust bands, which are thought to have been produced by recent asteroid collisions, and cometary trails. Interestingly, two of the detected dust trails, denoted t1 and t2 here, cannot be linked to any known comet. Trails t1 and t2 represent a much larger integrated brightness than all known cometary trails combined and may therefore be major contributors to the circumsolar dust cloud. We used our Spitzer observations to determine the orbits of these trails and were able to link them to two ("orphan" or type II) trails that were discovered by the Infrared Astronomical Satellite (IRAS) in 1983. The orbits of trails t1 and t2 that we determined by combining the Spitzer and IRAS data have semimajor axes, eccentricities, and inclinations like those of the main-belt asteroids. We therefore propose that trails t1 and t2 were produced by very recent (<~100 kyr old) collisional breakups of small, <~10 km diameter main-belt asteroids

Percutaneous endoscopic gastrostomy placement in paediatric Crohn's disease patients contributes to both improved nutrition and growth

Aim: This paper describes the outcomes of gastrostomy feeding in patients with Crohn's disease (CD). Methods: Patients with CD who attended the Royal Hospital for Children, Glasgow, and received gastrostomy feeding for at least two years between 2003-2010, were identified from the clinical database. The data recorded included the anthropometric data, CD phenotype, the surgical technique that was used, complications, medication, feed type, median feed, calories, volume and clinical outcomes. Results: The study identified 16 patients (14 male) who had a gastrostomy inserted using a pull technique at a median age of 12.6 years at. Of these two required laparoscopic placement. Short-term complications lasting less than one month were experienced by nine (56%) patients and one (6%) experienced long-term complications. Anthropometry significantly improved at follow up compared to baseline: at 12 months the body mass index z-score was 1.11 (p=0.005) and the weight z-score was 0.19 (p&lt;0.05). At 24 months the height z-score was -1.03 (p=0.04). The daily median volume and calories from feeds increased significantly from baseline to post PEG insertion, from 400-738ml and 705 to 860kcal/day (p&lt; =0.01). Conclusion: Gastrostomy feeding for paediatric patients with CD was associated with improved nutrition, weight gain and growth outcomes

Characteristics of ion flow in the quiet inner plasma sheet

Abstract We use AMPTE/IRM and ISEE 2 data to study the properties of the high beta (βi \u3e 0.5) plasma sheet, the inner plasma sheet (IPS). Bursty bulk flows (BBFs) are excised from the two databases, and the average flow pattern in the non-BBF (quiet) IPS is constructed. At local midnight this ensemble-average flow is predominantly duskward; closer to the flanks it is mostly earthward. The flow pattern agrees qualitatively with calculations based on the Tsyganenko [1987] model (T87), where the earthward flow is due to the ensemble-average cross tail electric field and the duskward flow is the diamagnetic drift due to an inward pressure gradient. The IPS is on the average in pressure equilibrium with the lobes. Because of its large variance the average flow does not represent the instantaneous flow field. Case studies also show that the non-BBF flow is highly irregular and inherently unsteady, a reason why earthward convection can avoid a pressure balance inconsistency with the lobes. The ensemble distribution of velocities is a fundamental observable of the quiet plasma sheet flow field

Spectral Irradiance Calibration in the Infrared

Five new absolutely calibrated continuous stellar spectra from 1.2 to 35 microns are presented. The spectra were constructed as far as possible from actual observed spectral fragments taken from the ground, the Kuiper Airborne Observatory (KAO), and the IRAS Low Resolution Spectrometer (LRS). These stars (beta Peg, alpha Boo, beta And, beta Gem, and alpha Hya) augment the author's already created complete absolutely calibrated spectrum for alpha Tau. All these spectra have a common calibration pedigree. The wavelength coverage is ideal for calibration of many existing and proposed ground-based, airborne, and satellite sensors

Laser-powered lunar base

The objective was to compare a nuclear reactor-driven Sterling engine lunar base power source to a laser-to-electric converter with orbiting laser power station, each providing 1 MW of electricity to the lunar base. The comparison was made on the basis of total mass required in low-Earth-orbit for each system. This total mass includes transportation mass required to place systems in low-lunar orbit or on the lunar surface. The nuclear reactor with Sterling engines is considered the reference mission for lunar base power and is described first. The details of the laser-to-electric converter and mass are discussed. The next two solar-driven high-power laser concepts, the diode array laser or the iodine laser system, are discussed with associated masses in low-lunar-orbit. Finally, the payoff for laser-power beaming is summarized

Spectral Irradiance Calibration in the Infrared

We present five new absolutely calibrated continuous stellar spectra from 1.2 to 35 microns, constructed as far as possible from actual observed spectral fragments taken from the ground, the Kuiper Airborne Observatory (KAO), and the IRAS Low Resolution Spectrometer (LRS). These stars- beta Peg, alpha Boo, beta And, beta Gem, and alpha Hya-augment our already created complete absolutely calibrated spectrum for alpha Tau. All these spectra have a common calibration pedigree. The wavelength coverage is ideal for calibration of many existing and proposed ground-based, airborne, and satellite sensors

Highlights: Spring Council Meeting

Council members present at the May 24, 1981, meeting were Keiiti Aki, Steven Burges (for Jim Wallis), Peter S. Eagleson, E. R. Engdahl, Charles E. Helsley, James R. Heirtzler, Carl Kisslinger, Leslie H. Meredith, Chris N. K. Mooers, Norman F. Ness, Marcia M. Neugebauer, James J. O'Brien, Richard Rapp, Carl Sagan, James C. Savage, Joseph V. Smith, Fred Spilhaus, Donald L. Turcotte, James A. Van Allen, J. Tuzo Wilson, and Jay Winston (for Elmar R. Reiter until his arrival at 6:50 P.M.). David Strangway, representing the Canadian Geophysical Union, and Peter Steinhauser, representing the European Geophysical Society, were special observers at the meeting. Council meetings are open, and a number of section secretaries, committee chairmen, journal editors, and other members attended. The following major actions were adopted by the Council: The experiment of publishing oceanography and lower‐atmosphere papers in JGR Green issues alternate to those containing upper‐atmosphere papers will be continued through 1982. From preliminary indications the experiment seems to be working, but a full year of data, including a renewal cycle, is needed to assess the success of the experiment. Final decision will be made prior to the 1983 dues notices