Autonomous rendezvous and capture development infrastructure

In the development of the technology for autonomous rendezvous and docking, key infrastructure capabilities must be used for effective and economical development. This involves facility capabilities, both equipment and personnel, to devise, develop, qualify, and integrate ARD elements and subsystems into flight programs. One effective way of reducing technical risks in developing ARD technology is the use of the ultimate test facility, using a Shuttle-based reusable free-flying testbed to perform a Technology Demonstration Test Flight which can be structured to include a variety of additional sensors, control schemes, and operational approaches. This conceptual testbed and flight demonstration will be used to illustrate how technologies and facilities at MSFC can be used to develop and prove an ARD system

Baseline design of the filters for the LAD detector on board LOFT

The Large Observatory for X-ray Timing (LOFT) was one of the M3 missions selected for the phase A study in the ESA's Cosmic Vision program. LOFT is designed to perform high-time-resolution X-ray observations of black holes and neutron stars. The main instrument on the LOFT payload is the Large Area Detector (LAD), a collimated experiment with a nominal effective area of ~10 m 2 @ 8 keV, and a spectral resolution of ~240 eV in the energy band 2-30 keV. These performances are achieved covering a large collecting area with more than 2000 large-area Silicon Drift Detectors (SDDs) each one coupled to a collimator based on lead-glass micro-channel plates. In order to reduce the thermal load onto the detectors, which are open to Sky, and to protect them from out of band radiation, optical-thermal filter will be mounted in front of the SDDs. Different options have been considered for the LAD filters for best compromise between high quantum efficiency and high mechanical robustness. We present the baseline design of the optical-thermal filters, show the nominal performances, and present preliminary test results performed during the phase A study.Comment: Proc. SPIE 9144, Space Telescopes and Instrumentation 2014: Ultraviolet to Gamma Ray, 91446

Water Transport and the Evolution of CM Parent Bodies

Extraterrestrial water-bearing minerals are of great importance both for understanding the formation and evolution of the solar system and for supporting future human activities in space. Asteroids are the primary source of meteorites, many of which show evidence of an early heating episode and varying degrees of aqueous alteration. The origin and characterization of hydrated minerals (minerals containing H2O or OH) among both the main-belt and near-earth asteroids is important for understanding a wide range of solar system formation and evolutionary processes, as well as for planning for human exploration. Current hypotheses postulate asteroids began as mixtures of water ice and anhydrous silicates. A heating event early in solar system history was then responsible for melting the ice and driving aqueous alteration. The link between asteroids and meteorites is forged by reflectance spectra, which show 3-m bands indicative of bound OH or H2O on the C-class asteroids, which are believed to be the parent bodies of the carbonaceous chondrites in our collections. The conditions at which aqueous alteration occurred in the parent bodies of carbonaceous chondrites are thought to be well-constrained: at 0-25 C for less than 15 Myr after asteroid formation. In previous models, many scenarios exhibit peak temperatures of the rock and co-existing liquid water in more than 75 percent of the asteroid's volume rising to 150 C and higher, due to the exothermic hydration reactions triggering a thermal runaway effect. However, even in a high porosity, water-saturated asteroid very limited liquid water flow is predicted (distances of 100's nm at most). This contradiction has yet to be resolved. Still, it may be possible for water to become liquid even in the near-surface environment, for a long enough time to drive aqueous alteration before vaporizing or freezing then subliming. Thus, we are using physics- and chemistry-based models that include thermal and fluid transport as well as the effects of relevant chemical reactions, to investigate whether formation of hydrated minerals can occur in the surface and near-surface environments of carbonaceous type asteroids. These models will elucidate how the conditions within the parent body that cause internal aqueous alteration play themselves out at the asteroid's surface. We are using our models to determine whether the heat budget of 20-100-km bodies is sufficient to bring liquid water to the near-surface and cause mineral alteration, or whether additional heat input at the surface (i.e, by impacts) is needed to provide a transient liquid water source for mineral hydration without large- scale liquid water transport

Design and construction of an inverter using solar cell as a source of charger

The present study is basically on electricity generation in which solar cell or module is used to power an inverter. This can also be called photovoltaic system, because it consists of solar modules, solar charge controller, 24V.d.c battery and an inverter. Solar modules serve as source of charger through solar charge controller to the battery and inverter are used in converting the direct current into an alternating current for the domestic appliance. This study is very useful in electricity generation especially in a developing country such as Nigeria where there is epileptic power supply. It-’s use is far better than generating set because it needs less maintenance, it does not use fuel, it is not heavy, it is rugged, it does not need an alternating current for its charging and it is noiseless

APPLICATION OF POLYNUCLEAR AROMATIC HYDROCARBONS IN CHEMICAL FINGERPRINTING: THE NIGER DELTA CASE STUDY

Chemical fingerprinting is an aspect of environmental forensic investigation which involves chemical analysis of contaminants and associated chemicals to provide source specific information. Polynuclear Aromatic Hydrocarbons (PAHs) in the environment have 3 categories of sources namely petrogenic, pyrogenic and biogenic sources. Petrogenic PAHs are generated from geochemical alterations of organic mater. Pyrogenic PAHs originate when organic matter is incompletely combusted. Biogenic originate as a result of oxidation of microbial or plant derived compounds in older and deeper sediments. PAHs fingerprinting involves the determination of a number of quantitative diagnostic ratios of source specific marker PAH compounds. These quantitative diagnostic ratios may be used to distinguish petrogenic PAHs including phenanthrene/anthracene; benz(a)anthracene/chrysene; flouranthene/pyrene; phenanthrene/(phenanthrene+anthracene) and indeno(1,2,3-cd) pyrene/indeno (1,2,3-cd) pyrene + benzo (ghi) perylene from other sources. In this research over 40 environmental samples from the Niger Delta region were subjected to chemical fingerprinting employing some of the quantitative diagnostic ratios above with the aim of ascertaining the precise nature and source the contaminants. It was found that the PAHs contamination in the Niger Delta is not only emanating from petrogenic sources but other sources contribute significantly

Prevalence and determinants of smoking in Tirana city, Albania: a population-based survey.

BACKGROUND: Smoking is the leading cause of premature death in Europe yet there are still many countries in which there is little information on its patterns and determinants. Albania is one such country. METHODS: A survey of health and lifestyle, including questions on smoking practice and attitudes, and its determinants was undertaken in Tirana, the capital of Albania in mid 2001. SUBJECTS: One thousand one hundred and twenty adults aged 25 years and over (response rate 72.7%). RESULTS: Forty-one percent of the study population (61% male and 24% female) were current or ex-smokers-28% were current smokers (37.6% of males and 19.3% of females) and 13% were ex-smokers (23.4% of males and 4.7% of females). Age-standardized (to the European standard population) prevalence of smoking for the adult population of Tirana was 31.2% (42.8% in males and 21.2% in females). Smoking was most common among those aged 25-34 years (59% of males and 30% of females in this age group). Of the current smokers, 16.5% smoked more than 20 cigarettes/day, and 67.3% smoked the first cigarette within 30 min of waking. Only 11% of current smokers had tried to quit smoking once during their life. Concern about health was the most common reason for quitting cited by ex-smokers (44%). In men, smoking was inversely associated with educational achievement. While the probability of smoking decreases with age, there was no consistent association with employment or income. CONCLUSION: The prevalence of smoking in Albania is comparable with other Western societies. The high rates of smoking among young men and women suggest that tobacco will make an increasingly large contribution to premature morbidity and mortality in the future. The high rate of smoking among young women in Albania, while a common phenomenon in post-communist countries, is especially worrying. This study emphasizes the need for a robust, evidence-based strategy for tobacco control in Albania