The Space Debris Sensor Experiment

The Space Debris Sensor (SDS) is a NASA Class 1E technology demonstration external payload aboard the International Space Station (ISS). With approximately one square meter of detection area, the SDS is attached to the European Space Agency Columbus module facing the ISS velocity vector with minimal obstruction from ISS hardware. The SDS is the first flight demonstration of the Debris Resistive/Acoustic Grid Orbital NASA-Navy Sensor (DRAGONS) technology developed and matured over 10 years by the NASA Orbital Debris Program Office (ODPO), in concert with the DRAGONS consortium, to provide information on the sub-millimeter scale orbital debris environment. The SDS demonstrated the capacity to read 4 resistive grids at 1 Hz, 40 acoustic sensors at 500 kHz, and record and downlink impact data to the ground. Observable and derived data from the SDS could provide information to models that are critical to understanding risks the small debris environment poses to spacecraft in low Earth orbit. The technology demonstrated by the SDS is a major step forward in monitoring and characterizing the space debris environment. This paper will address the technical performance of the SDS during its operational lifetime and its realization of technical and scientific goals. The SDS was intended to operate for 3 years; however, the payload incurred multiple anomalies during its operational life. Subsequently termed Anomaly #1, the first was the symptomatic loss of low data rate 1553 channel command and telemetry. The second, Anomaly #2, was loss of all low- and medium-data rate (Ethernet) telemetry. Anomaly #2 proved to be unrecoverable, leading to loss of the payload after approximately 26 days on-board the ISS. Therefore, this paper also addresses the anomalies that occurred during operation of the SDS, their attribution, and their resolution. Lessons learned are described when relevant to anomaly identification, attribution, and resolution

The NASA Orbital Debris Engineering Model 3.1: Development, Verification, and Validation

The NASA Orbital Debris Program Office has developed the Orbital Debris Engineering Model (ORDEM) primarily as a tool for spacecraft designers and other users to understand the long-term risk of collisions with orbital debris. The newest version, ORDEM 3.1, incorporates the latest and highest fidelity datasets available to build and validate representative orbital debris populations encompassing low Earth orbit (LEO) to geosynchronous orbit (GEO) altitudes for the years 2016-2050. ORDEM 3.1 models fluxes for object sizes > 10 m within or transiting LEO and > 10 cm in GEO. The deterministic portion of the populations in ORDEM 3.1 is based on the U.S. Space Surveillance Network (SSN) catalog, which provides coverage down to approximately 10 cm in LEO and 1 m in GEO. Observational datasets from radar, in situ, and optical sources provide a foundation from which the model populations are statistically extrapolated to smaller sizes and orbit regions that are not well-covered by the SSN catalog, yet may pose the greatest threat to operational spacecraft. Objects in LEO ranging from approximately 5 mm to 10 cm are modeled using observational data from ground-based radar, namely the Haystack Ultrawideband Satellite Imaging Radar (HUSIR formerly known as Haystack). The LEO population smaller than approximately 3 mm in size is characterized based on a reanalysis of in situ data from impacts to the windows and radiators of the U.S. Space Transportation System orbiter vehicle, i.e., the Space Shuttle. Data from impacts on the Hubble Space Telescope are also used to validate the sub-millimeter model populations in LEO. Debris in GEO with sizes ranging from 10 cm to 1 m is modeled using optical measurement data from the Michigan Orbital DEbris Survey Telescope (MODEST). Specific, major debris-producing events, including the Fengyun-1C, Iridium 33, and Cosmos 2251 debris clouds, and unique populations, such as sodium-potassium droplets, have been re-examined and are modeled and added to the ORDEM environment separately. The debris environment greater than 1 mm is forecast using NASAs LEO-to- GEO ENvironment Debris model (LEGEND). Future explosions of intact objects and collisions involving objects greater than 10 cm are assessed statistically, and the NASA Standard Satellite Breakup Model is used to generate fragments from these events. Fragments smaller than 10 cm are further differentiated based on material density categories, i.e., high-, medium-, and low-density, to better characterize the potential debris risk posed to spacecraft. The future projection of the sub-millimeter environment is computed using a special small-particle degradation model where small particles are created from intact spacecraft and rocket bodies. This work discusses the development, features, and capabilities of the ORDEM 3.1 model; the ne new data analyses used to build the model populations; and sample verification and validation results

Infusing Social Justice Advocacy into Counselor Education: Strategies and Recommendations

As the counseling profession calls counselors to act as social justice advocates, it is imperative that they are prepared for this role. This places responsibility on counselor education programs to incorporate the necessary training into existing programs. There are strategies for infusing social justice advocacy instruction throughout the existing curricula with reasonable investments of time, energy, and funds. The purpose of this article is to offer practical strategies and recommendations, grounded in critical pedagogy and supported by a growing evidence base, that can be implemented in existing counselor education programs in order to provide a strong foundation for social justice advocacy work

Fixing DNA breaks during class switch recombination

Immunoglobulin (Ig) class switch recombination (CSR) involves the breakage and subsequent repair of two DNA sequences, known as switch (S) regions, which flank IgH constant region exons. The resolution of CSR-associated breaks is thought to require the nonhomologous end-joining (NHEJ) DNA repair pathway, but the role of the NHEJ factor DNA-dependent protein kinase catalytic subunit (DNA-PKcs) in this process has been unclear. A new study, in which broken IgH-containing chromosomes in switching B cells were visualized directly, clearly demonstrated that DNA-PKcs and, unexpectedly, the nuclease Artemis are involved in the resolution of switch breaks

Recycling of rayon industry effluent for the recovery and separation of Zn/Ca using Thiophosphinic extractant

In textile industries, waste effluent containing zinc is generated during the manufacture of rayon yam :trom the wood pulp or cotton linters. Due to the strict environmental regulations and the presence of toxic metallic and other constituents, the discharge of industrial effluents in the sewage or disposal of solid sludge as landfill is restricted. Before recycling of zinc as zinc sulphate solution to the spinning-bath of the rayon manufacturing plant the zinc sulphate solution must be free from calcium, which is deleterious to the process as gypsum precipitates with the increase in concentration and forms scale in the bath. In the present work an attempt has been made to develop a process following solvent extraction technique using thiophosphinic extractants, Cyanex 272 and 302 modified with isodecanol and diluted in kerosene to recover zinc from rayon effluent. Various process parameters viz. extraction of zinc from different concentration of solution, distribution ratio, selective extraction, 0/ A ratio on extraction and stripping from the loaded organic, complex formation in the organic phase etc. have been studied to see the feasibility of the process. The extractant Cyanex 302 has be~n found selective for the recovery of 99.99% of zinc from the effluent above equilibrium pH 3.4 maintaining the O/A ratio of 1/30 leaving all the calcium in the raffina1e. It selectively extracted zinc in the form of complex [RzZn.3RH]org and retained all the calcium in the aqueous raffinate. The zinc from the loaded Cyanex 302 can be stripped with 10% sulphuric acid at even 0/ A ratio of 10 without affecting the stripping efficiency. The stripped solution thus obtained could be recycled in the spinning bath of the rayon plant. The raffinate obtained after the recovery of zinc could be disposed safely without affecting environment

Human N ‐acetylation genotype determination with urinary caffeine metabolites

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109862/1/cptclpt199059.pd

Sensitivity to speech rhythm explains individual differences in reading ability independently of phonological awareness

This study considered whether sensitivity to speech rhythm can predict concurrent variance in reading attainment after individual differences in age, vocabulary and phonological awareness have been controlled. Five to six-year-old English-speaking children completed a battery of phonological processing assessments and reading assessments, along with a simple word stress manipulation task. The results showed that performance on the stress manipulation measure predicted a significant amount of variance in reading attainment after age, vocabulary, and phonological processing had been taken into account. These results suggest that stress sensitivity is an important, yet neglected aspect of English-speaking children?s phonological representations, which needs to be incorporated into theoretical accounts of reading development

Kriteria Planet Layak Huni sebagai Analisis Keberadaan Doppelganger Bumi

The discovery of extrasolar planets has reached rapid development. Until now, various earth-sized planets called terrestrial planets around their parent stars have been discovered . It is well known that some of these planets orbit their parent stars in habitable zone around their parent stars in class G-M. Some parameters have been determined to re-categorize these planets whether as habitable planets or as Earth's doppelganger, so that various fundamental parameters assumptions to re-categorize the planets appear. We have studied 300 extrasolar planets－ located in habitable zone － data by using our calculations to determine the fundamental parameters which determine the position of these planets whether as habitable or as Earth's doppelganger. Earth's doppelganger must be able to maintain water in liquid form and must have fingerprints which are exactly same like Earth does. Therefore, we determine four fundamental parameters, the physical condition of the planet, the surface temperature of the planet, the parent star parameters, and the location of the habitable zone. We set the Earth's doppelganger to have the standard parameter of ±1 and assume all of Earth parameters as the standard values. After carrying out four analysis processes, we have foundonly two Earth's doppelganger candidates

Response vs. Perception

Three experiments were conducted in which college students read, and then attempted to match, a series of written descriptive passages with the referent photographs on which they were based; the photographs sho wed the face of an actor, representing a variety of emotional expressions. In Experiment I, subjects provided with a series of context passages depicting a narrow range of emotions (neither pleasant nor unpleasant) chose “matches” having more extreme pleasantness values than did subjects provided with context passages depicting a wide range of descriptions on the pleasantness dimension when responding to test descriptions embedded within the context series. In Experiments II and III, contrast effects were obtained; subjects who had read mostly unpleasant context passages chose more pleasant referents in response to neutral test descriptions than did those who had read mostly pleasant descriptions. The results of all three experiments suggested that these effects were mediated in large part by a response bias, the tendency to use each response alternative with roughly equal frequency. In Experiments II and III, there was suggestive evidence for the possibility that a more central (or perceptual) mechanism may also have contributed to the observed results.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45367/1/11031_2004_Article_BF00992590.pd

Leaching of Korean monazite for the recovery of rare earth metals

The technological innovations resulted in various applications using rare earth metals (REM), which lead to a steep increase in their demand. Monazite is the second most essential naturally occurring phosphate mineral containing REM. The present work reports the recovery of REM from Korean monazite which contained mainly 50.12% rare earth oxide and 29.4% phosphate. For the recovery of REM from monazite, the hydrometallurgical process consisting of alkaline leaching of phosphate followed by acid dissolution of REM has been reported. As the presence of phosphate decreases the leaching efficiency of REM from monazite, the studies were carried out initially for hot digestion of phosphate present in the monazite in an autoclave using sodium hydroxide, which resulted in the formation of RE oxide and soluble sodium phosphate. To get the optimum condition for phosphate decomposition by alkaline leaching, the various process parameters such as concentration of sodium hydroxide, temperature, mixing time and pulp density were studied. The obtained slurry was washed with hot water and filtered to get sodium phosphate in the solution. A maximum of 99% phosphate was removed from monazite concentrate using 50% sodium hydroxide solutions (wt./vol.) at 170oC in 4 h mixing time maintaining the pulp density of 100 g/L. From the phosphate free monazite sample, REM was leached out using hydrochloric acid. More than 95% of REM was found to be leached out using 6M HCl at constant pulp density 100 g/L, temperature 90oC and mixing time 2 h. Further studies are in progress to obtain pure solution and salts of REM from chloride leach liquor using recipitation/ solvent extraction/ ion-exchange techniques