Aerodynamic and acoustic effects of eliminating core swirl from a full scale 1.6 stage pressure ratio fan (QF-5A)

Fan QF-5A was a modification of fan QF-5 which had an additional core stator and adjusted support struts to turn the core exit flow from a 30 deg swirl to the axial direction. This modification was necessary to eliminate the impingement of the swirling core flow on the axial support pylon of the NASA-Lewis Quiet Fan Facility that caused aerodynamic, acoustic and structural problems with the original fan stage at fan speeds greater than 85 percent of design. The redesigned fan QF-5A did obtain the design bypass ratio with an increased core airflow suggesting that the flow problem was resolved. Acoustically, the redesigned stage showed a low frequency broadband noise reduction compared to the results for fan QF-5 at similar operating conditions

How Two Sides of the Atlantic Contributed to Understanding of the Global Oceans: Charles Yentsch and Andre Morel

In a few short days in September of this year, the ocean color/ocean optics community lost two of the founding members of its Hall of FameCharles Yentsch and Andre Morel. Yentsch passed away at the age of 85 on September 19, and Morel passed away on September 23 at the age of 79. It might sound clich to say that someone was instrumental to the advance of science in a particular field, but in the case of Yentsch and Morel and ocean color instrumentation, such an assessment would likely be accurate. Each mans career complimented that of the other Yentsch was one of the first to make measurements of the light field of the ocean from altitude and to advocate an instrument in space that could observe the spectrum of ocean radiance Morels theoretical underpinnings established a firm foundation for the measurements such an instrument could make, allowing their successful interpretation

Composition, distribution and supposed origin of mineral inclusions in sessile oak wood - consequences for microdensitometrical analysis

SEM and light-microscopical observations, supported by chemical microanalysis with an EDXA system, revealed that light-saturated pixels observed in X-ray negatives of sessile oak (Quercus petraea Liebl.) wood were caused by inorganic deposits present inside multiseriate ray and axial parenchyma cells. Calcium oxalate crystals, silica grains and amorphous granules with varied mineral compositions have been identified. The wood strips of three out of six sampled trees contained measurable amounts of mineral inclusions which were quantified using image analysis. Based on the variations of mineral content observed between trees and within and between annual rings of the same tree, some hypotheses were formulated concerning the factors involved in the formation of inorganic deposits in oak wood. Their occurrence varies depending on the mineral concerned and seems to be controlled largely by a tree effect. The time of formation appears to coincide with a shifting of the oak wood’s functions as a result of heartwood formation processes (inter-annual scale) or changes in leaf phenology and climate (intra-annual scale). In addition, the technical consequences of their presence as well as their effects on wood density measurements through microdensitometry are discussedComposition, distribution et origine supposée d’inclusions minérales dans le bois de chêne sessile – conséquences pour l’analyse microdensitométrique. Des observations à l’aide de microscopes électronique à balayage et optique, appuyées par des analyses élémentaires au moyen d’un système EDXA, ont révélé que les points-images saturés en niveau de gris, constatés dans les négatifs de radiographies de bois de chêne sessile (Quercus petraea Liebl.), étaient dus à des dépôts inorganiques présents à l’intérieur des cellules parenchymateuses des rayons ligneux multisériés et du parenchyme axial. Des cristaux d’oxalate de calcium, des grains de silice et des granules amorphes ayant des compositions minérales variées ont été identifiés. Des barrettes de trois sur six arbres échantillonnés contenaient des quantités mesurables d’inclusions minérales qui ont été quantifiées par analyse d’images. En se basant sur les variations du contenu en dépôts minéraux observées entre arbres ainsi qu’à l’intérieur d’un arbre, aux niveaux intra- et intercerne, quelques hypothèses ont été avancées concernant les facteurs potentiellement responsables de la formation de dépôts minéraux chez le chêne. Leur présence dépend du minéral concerné et semble être contrôlée par un fort effet arbre. L’apparition des minéraux coïncide apparemment avec des changements de fonctions du bois relatifs aux processus de duraminisation (échelle interannuelle) ou correspondant à des évolutions phénologiques ou climatiques (échelle intra-annuelle). Enfin, les conséquences techniques ainsi que les effets de leur présence sur des mesures de la densité du bois par analyse microdensitométrique sont discuté

Generalizing about trade show effectiveness: a cross-national comparison.

Trade shows are a multi-billion dollar business in the US and the UK, but little is known about the determinants of trade show effectiveness. In this paper, we build a model that explains differences in trade show effectiveness across industries, across companies and across two countries. We focus on the differences in trade show effectiveness measured in a similar way across similar samples of 171 US and 135 UK firm-show experiences between 1980 and 1991. While the similarities outweigh the differences, we find evidence that trade shows are viewed differently by exhibitors and attendees in these two countries. We are able to make substantial generalizations about the effect of various show selection (go-not go) variables (booth size, personnel, etc.) on observed performance. We discuss the implications of our research for developing benchmarks for trade show performance and for better global management of the business marketing communications mix.Effectiveness; Trade;

Preliminary tests of the electrostatic plasma accelerator

This report describes the results of a program to verify an electrostatic plasma acceleration concept and to identify those parameters most important in optimizing an Electrostatic Plasma Accelerator (EPA) thruster based upon this thrust mechanism. Preliminary performance measurements of thrust, specific impulse and efficiency were obtained using a unique plasma exhaust momentum probe. Reliable EPA thruster operation was achieved using one power supply

Three-Flavour Neutrino-Mixing Implications of the LSND Result

The LSND result is shown to fit into a minimal three-flavour neutrino-mixing scenario capable of describing all known experimental facts provided the large Delta M^2 = m_3^2 - m_2^2 \sim m_3^2 - m_1^2 lies in the range 2.5 x 10^{-1} < Delta M^2 < 3.0 eV^2. In this range the value of P_{\mu\tau} is expected to be about 5% or larger.Comment: 10 pages, 2 eps figures, LaTeX 2.09, revised for Physics Letters

Using the NASA Giovanni DICCE Portal to Investigate Land-Ocean Linkages with Satellite and Model Data

Data-enhanced Investigations for Climate Change Education (DICCE), a NASA climate change education project, employs the NASA Giovanni data system to enable teachers to create climate-related classroom projects using selected satellite and assimilated model data. The easy-to-use DICCE Giovanni portal (DICCE-G) provides data parameters relevant to oceanic, terrestrial, and atmospheric processes. Participants will explore land-ocean linkages using the available data in the DICCE-G portal, in particular focusing on temperature, ocean biology, and precipitation variability related to El Ni?o and La Ni?a events. The demonstration includes the enhanced information for educators developed for the DICCE-G portal. The prototype DICCE Learning Environment (DICCE-LE) for classroom project development will also be demonstrated

Using NASA's Giovanni System to Simulate Time-Series Stations in the Outflow Region of California's Eel River

Oceanographic time-series stations provide vital data for the monitoring of oceanic processes, particularly those associated with trends over time and interannual variability. There are likely numerous locations where the establishment of a time-series station would be desirable, but for reasons of funding or logistics, such establishment may not be feasible. An alternative to an operational time-series station is monitoring of sites via remote sensing. In this study, the NASA Giovanni data system is employed to simulate the establishment of two time-series stations near the outflow region of California s Eel River, which carries a high sediment load. Previous time-series analysis of this location (Acker et al. 2009) indicated that remotely-sensed chl a exhibits a statistically significant increasing trend during summer (low flow) months, but no apparent trend during winter (high flow) months. Examination of several newly-available ocean data parameters in Giovanni, including 8-day resolution data, demonstrates the differences in ocean parameter trends at the two locations compared to regionally-averaged time-series. The hypothesis that the increased summer chl a values are related to increasing SST is evaluated, and the signature of the Eel River plume is defined with ocean optical parameters

MSW mediated neutrino decay and the solar neutrino problem

We investigate the solar neutrino problem assuming simultaneous presence of MSW transitions in the sun and neutrino decay on the way from sun to earth. We do a global $\chi^2$-analysis of the data on total rates in Cl, Ga and Superkamiokande (SK) experiments and the SK day-night spectrum data and determine the changes in the allowed region in the \dm - \tan^2\theta plane in presence of decay. We also discuss the implications for unstable neutrinos in the SNO experiment.Comment: Final version to appear in Phys. Rev.

Influence of Averaging Method on the Evaluation of a Coastal Ocean Color Event on the U.S. Northeast Coast

Application of appropriate spatial averaging techniques is crucial to correct evaluation of ocean color radiometric data, due to the common log-normal or mixed log-normal distribution of these data. Averaging method is particularly crucial for data acquired in coastal regions. The effect of averaging method was markedly demonstrated for a precipitation-driven event on the U.S. Northeast coast in October-November 2005, which resulted in export of high concentrations of riverine colored dissolved organic matter (CDOM) to New York and New Jersey coastal waters over a period of several days. Use of the arithmetic mean averaging method created an inaccurate representation of the magnitude of this event in SeaWiFS global mapped chl a data, causing it to be visualized as a very large chl a anomaly. The apparent chl a anomaly was enhanced by the known incomplete discrimination of CDOM and phytoplankton chlorophyll in SeaWiFS data; other data sources enable an improved characterization. Analysis using the geometric mean averaging method did not indicate this event to be statistically anomalous. Our results predicate the necessity of providing the geometric mean averaging method for ocean color radiometric data in the Goddard Earth Sciences DISC Interactive Online Visualization ANd aNalysis Infrastructure (Giovanni)