Arcjet Testing and Thermal Model Development for Multilayer Felt Reusable Surface Insulation

Felt Reusable Surface Insulation was used extensively on leeward external surfaces of the Shuttle Orbiter, where the material is reusable for temperatures up to 670 K. For application on leeward surfaces of the Orion Multi-Purpose Crew Vehicle, where predicted temperatures reach 1620 K, the material functions as a pyrolyzing conformal ablator. An arcjet test series was conducted to assess the performance of multilayer Felt Reusable Surface Insulation at high temperatures, and a thermal-response, pyrolysis, and ablation model was developed. Model predictions compare favorably with the arcjet test dat

Hydraulic Apparatus for Mechanical Testing of Nuts

The figure depicts an apparatus for mechanical testing of nuts. In the original application for which the apparatus was developed, the nuts are of a frangible type designed for use with pyrotechnic devices in spacecraft applications in which there are requirements for rapid, one-time separations of structures that are bolted together. The apparatus can also be used to test nonfrangible nuts engaged without pyrotechnic devices. This apparatus was developed to replace prior testing systems that were extremely heavy and immobile and characterized by long setup times (of the order of an hour for each nut to be tested). This apparatus is mobile, and the setup for each test can now be completed in about five minutes. The apparatus can load a nut under test with a static axial force of as much as 6.8 x 10(exp 5) lb (3.0 MN) and a static moment of as much as 8.5 x 10(exp 4) lb in. (9.6 x 10(exp 3) N(raised dot)m) for a predetermined amount of time. In the case of a test of a frangible nut, the pyrotechnic devices can be exploded to break the nut while the load is applied, in which case the breakage of the nut relieves the load. The apparatus can be operated remotely for safety during an explosive test. The load-generating portion of the apparatus is driven by low-pressure compressed air; the remainder of the apparatus is driven by 110-Vac electricity. From its source, the compressed air is fed to the apparatus through a regulator and a manually operated valve. The regulated compressed air is fed to a pneumatically driven hydraulic pump, which pressurizes oil in a hydraulic cylinder, thereby causing a load to be applied via a hydraulic nut (not to be confused with the nut under test). During operation, the hydraulic pressure is correlated with the applied axial load, which is verified by use of a load cell. Prior to operation, one end of a test stud (which could be an ordinary threaded rod or bolt) is installed in the hydraulic nut. The other end of the test stud passes through a bearing plate; a load cell is slid onto that end, and then the nut to be tested is threaded onto that end and tightened until the nut and load cell press gently against the bearing plate

A 1200-μm MAMBO survey of the GOODS-N field: a significant population of submillimetre dropout galaxies

We present a 1200-mu m image of the Great Observatories Origin Deep Survey North (GOODS-N) field, obtained with the Max Planck Millimetre Bolometer array (MAMBO) on the IRAM 30-m telescope. The survey covers a contiguous area of 287 arcmin(^2) to a near-uniform noise level of similar to 0.7mJy beam(^-1). After Bayesian flux deboosting, a total of 30 sources are recovered (>= 3.5 sigma). An optimal combination of our 1200-mu m data and an existing 850-mu m image from the Submillimetre Common-User Bolometer Array (SCUBA) yielded 33 sources (>= 4 sigma). We combine our GOODS-N sample with those obtained in the Lockman Hole and ELAIS N2 fields (Scott et al. 2002; Greve et al. 2004) in order to explore the degree of overlap between 1200-and 850-mu m-selected galaxies (hereafter SMGs), finding no significant difference between their S-850 mu m/S-1200 mu m distributions. However, a noise-weighted stacking analysis yields a significant detection of the 1200-mu m-blank SCUBA sources, S-850 mu m/S-1200 mu m = 3.8 +/- 0.4, whereas no significant 850-mu m signal is found for the 850-mu m-blank MAMBO sources (S-850 mu m/S-1200 mu m = 0.7 +/- 0.3). The hypothesis that the S-850 mu m/S-1200 mu m distribution of SCUBA sources is also representative of the MAMBO population is rejected at the similar to 4 sigma level, via Monte Carlo simulations. Therefore, although the populations overlap, galaxies selected at 850 and 1200 mu m are different, and there is compelling evidence for a significant 1200-mu m-detected population which is not recovered at 850 mu m. These are submillimetre dropouts (SDOs), with S-850 mu m/S-1200 mu m = 0.7-1.7, requiring very cold dust or unusual spectral energy distributions (T-d similar or equal to 10 K; beta similar or equal to 1), unless SDOs reside beyond the redshift range observed for radio-identified SMGs, i. e. at z > 4

Time Variable Gravity modeling for Precise Orbits Across the TOPEX/Poseidon, Jason-l and Jason-2 Missions

Modeling of the Time Variable Gravity (TVG) is believed to constitute one of the the largest remaining source of orbit error for altimeter satellite POD. The GSFC operational TVG model consists of forward modeling the atmospheric gravity using ECMWF 6-hour pressure data, a GRACE derived 20x20 annual field to account for changes in the hydrology and ocean water mass, and linear rates for C20, C30, C40, based on 17 years of SLR data analysis (IERS 2003) using the EIGEN-GL04S1 (a GRACE+Lageos-based geopotential solution). Although the GSFC Operational model can be applied from 1987, there may be long-term variations not captured by these linear models, and more importantly the linear models may not be consistent with more recent surface mass trends due to global climate change, We have evaluated the impact of TVG in two different wavs: (1) by using the more recent EIGEN-6S gravity model developed by the GFZ/GRGS tearm, which consists of annual, semi-annual and secular changes in the coefficients to 50x50 determined over 8(?) years of GRACE+Lageos+GOCE data (2003-200?): (2) Application of 4x4 solutions developed from a multi satellite SLR+DORIS solution based on GGM03S that span the period from 1993 to 2011. We have evaluated the recently released EIGEN6s static and time-varying gravity field for Jason-2 (J2). Jason-I (J1), and TOPEX/Posiedon (TP) Precise Orbit Determination (POD) spanning 1993-2011. Although EIGEN6s shows significant improvement for J2POD spanning 2008 - 2011, it also shows significant degradation for TP POD from 1992. The GSFC 4x4 time SLR+DORIS-based series spans 1993 to mid 2011, and shows promise for POD. We evaluate the performance of the different TVG models based on analysis of tracking data residuals use of independent data such as altimeter crossovers, and through analysis of differences with internally-generated and externally generated orbits

Missouri Representative Farms Financial Projections

This document presents an estimate of financial risk on individual Missouri representative farms in future years.This material is based upon work supported by Cooperative States Research Education and Extension Service, U.S. Department of Agriculture, under Agreement No. 00-34228-8988 and Missouri Department of Agriculture proposal #00112091

Cost Effectiveness Analysis Evaluating Real-Time Characterization of Diminutive Colorectal Polyp Histology using Narrow Band Imaging (NBI)

Background: Endoscopists and new computer-aided programs can achieve performance benchmarks for real-time diagnosis of colorectal polyps using Narrow-Band Imaging (NBI), though do not perform as well as endoscopists with expertise in advanced imaging. Previous cost-effectiveness studies on optical diagnosis have focused on expert performance, potentially over-estimating its benefits. Aim: Determine cost-effectiveness of an NBI ‘characterize, resect and discard (CRD)’ strategy using updated assumptions based on non-expert performance. Methods: Markov model was constructed to compare cost-effectiveness of the CRD strategy, where diminutive polyps characterized as non-adenomas with high confidence are not resected and adenomas are resected and discarded, versus standard of care (SOC) in which all polyps are resected with histologic analysis. Rates related to NBI performance, missed polyps, polyp progression, malignancy, and complications, as well as quality-adjusted life years (QALYs) were derived from the literature. Costs were age and insurer-specific. Mean QALYs and costs were calculated using first order Monte Carlo simulation. Deterministic and probabilistic sensitivity analyses were conducted. Results: The mean QALY estimates were similar for the CRD (8.563, 95% CI: 8.557-8.571) and SOC strategy (8.563, 8.557-8.571), but costs were reduced ($2,693.06 vs.$2,800.27, mean incremental cost savings: $107.21/person). Accounting for colonoscopy rates, the CRD strategy would save$708 million to $1.06 billion annually. The model was sensitive to the incidence of tubular adenomas; the results were otherwise robust in all other one-way and probabilistic analyses. Conclusions: An NBI CRD strategy is cost-effective when compared to the SOC, even when employed by non-experts. The appreciated benefit is primarily due to cost savings of the CRD strategy

The Impact of Temporal Geopotential Variations on GPS

Lemoine et al. (2006) and Lemoine et al. (2010) showed that applying more detailed models of time-variable gravity (TVG) improved the quality of the altimeter satellite orbits (e.g. TOPEX/Poseidon, Jason-1, Jason-2). This modeling include application of atmospheric gravity derived from 6-hrly pressure fields obtained from the ECMWF and annual gravity variations to degree & order 20x20 in spherical harmonics derived from GRACE data. This approach allowed the development of a consistent geophysical model for application to altimeter satellite orbit determination from 1993 to 2011. In addition, we have also evaluated the impact of TVG modeling on the POD of Jason-1 and Jason-2 by application of a weekly degree & order four gravity coefficient time series developed using data from ten SLR & DORIS-tracked satellites from 1993 to 2011 (Lemoine et al., 2011)

Origins of the extragalactic background at 1mm from a combined analysis of the AzTEC and MAMBO data in GOODS-N

We present a study of the cosmic infrared background, which is a measure of the dust obscured activity in all galaxies in the Universe. We venture to isolate the galaxies responsible for the background at 1mm; with spectroscopic and photometric redshifts we constrain the redshift distribution of these galaxies. We create a deep 1.16mm map (sigma ~ 0.5mJy) by combining the AzTEC 1.1mm and MAMBO 1.2mm datasets in GOODS-N. This combined map contains 41 secure detections, 13 of which are new. By averaging the 1.16mm flux densities of individually undetected galaxies with 24um flux densities > 25uJy, we resolve 31--45 per cent of the 1.16mm background. Repeating our analysis on the SCUBA 850um map, we resolve a higher percentage (40--64 per cent) of the 850um background. A majority of the background resolved (attributed to individual galaxies) at both wavelengths comes from galaxies at z > 1.3. If the ratio of the resolved submillimeter to millimeter background is applied to a reasonable scenario for the origins of the unresolved submillimeter background, 60--88 per cent of the total 1.16mm background comes from galaxies at z > 1.3.Comment: 12 pages, 10 figures. Accepted by MNRAS. The combined map is publicly available at http://www.astro.umass.edu/~pope/goodsn_mm