QCGAT aircraft/engine design for reduced noise and emissions

The high bypass ratio QCGAT engine played an important role in shaping the aircraft design. The aircraft which evolved is a sleek, advanced design, six-place aircraft with 3538 kg (7,800 lb) maximum gross weight. It offers a 2778 kilometer (1500 nautical mile) range with cruise speed of 0.5 Mach number and will take-off and land on the vast majority of general aviation airfields. Advanced features include broad application of composite materials and a supercritical wing design with winglets. Full-span fowler flaps were introduced to improve landing capability. Engines are fuselage-mounted with inlets over the wing to provide shielding of fan noise by the wing surfaces. The design objectives, noise, and emission considerations, engine cycle and engine description are discussed as well as specific design features

CHANGE AND CONFLICT IN LAND AND WATER USE: RESOURCE VALUATION IN CONFLICT RESOLUTION AMONG COMPETING USERS

Resource /Energy Economics and Policy,

COASTAL ALABAMA RECREATIONAL LIVE BAIT STUDY

Recreational fishing is major industry and reasonably priced, high quality bait plays an important role in sustaining recreational fishing's popularity. This study provides a summary of Alabama's coastal live bait market including information on previous live bait studies and results of two surveys on the live bait shrimp, bull minnow and other bait markets. Results indicated there were periods of supply shortages, dealer willingness to pay more for shrimp that live longer and a dealers' use of multiple supply sources. Lost income was reported from not having live bait shrimp available for sale at peak demand periods. The economics of shrimp mariculture needs to be examined to determine its feasibility in augmenting the current supply of shrimp to the live bait industry.Resource /Energy Economics and Policy,

Correlation of Hotspot Isotopic Data with Mantle Tomography

Isotopic data have been gathered from igneous rocks at areas believed to be hotspots. These data include ratios of ^(208)Pb/^(204)Pb, ^(206)Pb/^(204)Pb, ^(207)Pb/^(204)Pb, ^(87)Sr/^(86)Sr, and ^(143)Nd/^(144)Nd. The lead ratios are typically expressed as deviations from the reference lines given by: (^(207)Pb/^(204)Pb) NHRL = 0.1084 (^(206)Pb/^(204)Pb) +13.491. (^(208)Pb/^(204)Pb) NHRL = 1.209 (^(206)Pb/^(204)Pb) +15.627. The expressions for these deviations are given by: Δ7/4 = [(^(207)Pb/^(204)Pb)-(^(207)Pb/^(204)Pb)NHRL]x100. Δ8/4 = [(^(208)Pb/^(204)Pb)-(^(208)Pb/^(204)Pb)NHRL]x100. For the strontium and neodymium ratios, the following expressions are used: ΔSr = {[(^(87)Sr/^(86)Sr)-0.7]-[(^(87)Sr/^(86)Sr)REF-0.7]}x10^4. ΔNd = {[(^(143)Nd/^(144)Nd)-0.51]-[(^(143)Nd/^(144)Nd)REF-0.51]}x10^4. (^(87)Sr/^(86)Sr)REF = .70368. (^(143)Nd/^(144)Nd)REF = .512907. This is the same system for lead used by Hart (1984). The baseline strontium and neodymium ratios, used above, are the median values of the strontium and neodymium isotopic ratios used in this study. The "standard" for strontium is from the Comores hotspot, and the neodymium "standard" is from St. Helena. All of these isotopes and their parent elements are incompatible, entering melts preferentially, but the important aspects of these elements are their relative incompatibilities. It is expected that melts extracted from primitive mantle material would have higher U/Pb, Th/Pb and Rb/Sr ratios than primitive mantle owing to the greater incompatibility of the parent elements as compared to the daughter elements. Conversely, the higher incompatibility of neodymium as compared to its parent, samarium, would result in a lower Sm/Nd ratio in the melt. Castillo (1988) claimed that the Dupal anomaly correlated well with low velocity regions in the lower mantle. In addition, all degree except 2 and 3 in the tomography were discarded. This study examines the quantitative significance of this correlation with the lower mantle, and, since the correlation is to be done depth by depth, it should be possible to determine the depths at which these correlations occur. Additionally, correlations in the upper mantle and at other degrees will be found and evaluated

Spherical disharmonies in the Earth sciences and the spatial solution: Ridges, hotspots, slabs, geochemistry and tomography correlations

There is increasing use of statistical correlations between geophysical fields and between geochemical and geophysical fields in attempts to understand how the Earth works. Typically, such correlations have been based on spherical harmonic expansions. The expression of functions on the sphere as spherical harmonic series has many pitfalls, especially if the data are nonuniformly and/or sparsely sampled. Many of the difficulties involved in the use of spherical harmonic expansion techniques can be avoided through the use of spatial domain correlations, but this introduces other complications, such as the choice of a sampling lattice. Additionally, many geophysical and geochemical fields fail to satisfy the assumptions of standard statistical significance tests. This is especially problematic when the data values to be correlated with a geophysical field were collected at sample locations which themselves correlate with that field. This paper examines many correlations which have been claimed in the past between geochemistry and mantle tomography and between hotspot, ridge, and slab locations and tomography using both spherical harmonic coefficient correlations and spatial domain correlations. No conclusively significant correlations are found between isotopic geochemistry and mantle tomography. The Crough and Jurdy (short) hotspot location list shows statistically significant correlation with lowermost mantle tomography for degree 2 of the spherical harmonic expansion, but there are no statistically significant correlations in the spatial case. The Vogt (long) hotspot location list does not correlate with tomography anywhere in the mantle using either technique. Both hotspot lists show a strong correlation between hotspot locations and geoid highs when spatially correlated, but no correlations are revealed by spherical harmonic techniques. Ridge locations do not show any statistically significant correlations with tomography, slab locations, or the geoid; the strongest correlation is with lowermost mantle tomography, which is probably spurious. The most striking correlations are between mantle tomography and post-Pangean subducted slabs. The integrated locations of slabs correlate strongly with fast areas near the transition zone and the core-mantle boundary and with slow regions from 1022–1284 km depth. This seems to be consistent with the “avalanching” downwellings which have been indicated by models of the mantle which include an endothermic phase transition at the 670-km discontinuity, although this is not a unique interpretation. Taken as a whole, these results suggest that slabs and associated cold downwellings are the dominant feature of mantle convection. Hotspot locations are no better correlated with lower mantle tomography than are ridge locations

Largest IM Platform In China Tecents QQ

This case illustrates how Mainland China based Tencent Holdings Ltd., through focusing on its core competencies, has rapidly evolved into a technology powerhouse in the global Instant Messaging market. In just over a decade, the company has influenced and changed the communication methods and life-style of hundreds of millions of Chinese in China and around the world. Staying true to its core competencies, such as intense attention to innovation, efficiency, and customer responsiveness, the company successfully expanded its marketplace footprint from a locally-sighted, straight-forward telecommunications service provider into a complex, internet value-added service provider with a global reach. This case includes an introduction to the instant messaging industry, followed by a profile of the company. Also, an extensive analysis of Tencents core competencies is presented, along with a summary of the companys path towards internationalization