Performance of a transonic fan stage designed for a low meridional velocity ratio

The aerodynamic performance and design parameters of a transonic fan stage are presented. The fan stage was designed for a meridional velocity ratio of 0.8 across the tip of the stage, a pressure ratio of 1.57, a flow of 29.5 kilograms per second, and a tip speed of 426 meters per second. Radial surveys were obtained over the stable operating range from 50 to 100 percent of design speed. The measured, peak efficiency (0.81) of the stage occurred at a pressure ratio of 1.58 and a flow of 28.7 kilograms per second

Accelerated Consolidation of Soft Clays Using Wick Drains

Construction of the New Istana for the Sultan of Brunei required that fill slopes up to 85 feet high be placed on very soft compressible floodplain soils. Wick drains installed in the soft sediments accelerated their consolidation and reduced long-term settlements. The consolidation also produced a strength increase in the soft soils that allowed the fill to be constructed without danger of a major base slip failure. Instrumentation installed in the floodplain soils provided data on excess porepressures built up during the fill placement, and on the resulting settlements. The measured porepressures and settlements were in good agreement with the predicted values

Silver Engineered Nanomaterials and Ions Elicit Species-Specific O\u3csub\u3e2\u3c/sub\u3e Consumption Responses in Plant Growth Promoting Rhizobacteria

Metal containing engineered nanomaterials (ENMs) are now commonly used in various industrial and commercial applications. Many of these materials can be transformed during waste water treatment and ultimately enter terrestrial ecosystems via agriculturally applied biosolids. It is unclear how agriculturally important soil microbes will be affected by exposure to environmentally relevant, sublethal concentrations of ENMs and their transformation products (i.e., ions, aggregates, etc.). A method was developed, which puts O2 consumption responses in terms of viability, and tested by examining the toxic effects of Ag+, Zn2+, and Ni2+ ions on the plant growth promoting rhizobacterium (PGPR) Bacillus amyloliquefaciens GB03. The method was then used to examine the toxicity of Ag+, as-synthesized polyvinylpyrrolidone-coated silver ENM (PVP-AgENMs), and 100% sulfidized AgENM on B. amyloliquefaciens GB03, and two additional PGPRs Sinorhizobium meliloti 2011, and Pseudomonas putida UW4. S. meliloti was found to have the highest LC50 for Ag+ and PVP-AgENMs (6.6 and 207 μM, respectively), while B. amyloliquefaciens and P. putida exhibited LC50\u27s for Ag+ and PVP-AgENMs roughly half those observed for S. meliloti. The authors observed species-specific O2 consumption responses to ENM and ion exposure. PVP-AgENMs were less toxic than ions on a molar basis, and abiotic dissolution likely explains a significant portion of the observed toxic responses. Our results suggest microbes may exhibit distinct metabolic responses to metal and ENM exposure, even when similar LC50\u27s are observed. These findings together illustrate the importance of understanding species-specific toxic responses and the utility of examining O2 consumption for doing so

Unitary relation between a harmonic oscillator of time-dependent frequency and a simple harmonic oscillator with and without an inverse-square potential

The unitary operator which transforms a harmonic oscillator system of time-dependent frequency into that of a simple harmonic oscillator of different time-scale is found, with and without an inverse-square potential. It is shown that for both cases, this operator can be used in finding complete sets of wave functions of a generalized harmonic oscillator system from the well-known sets of the simple harmonic oscillator. Exact invariants of the time-dependent systems can also be obtained from the constant Hamiltonians of unit mass and frequency by making use of this unitary transformation. The geometric phases for the wave functions of a generalized harmonic oscillator with an inverse-square potential are given.Comment: Phys. Rev. A (Brief Report), in pres

Geometric Phase, Hannay's Angle, and an Exact Action Variable

Canonical structure of a generalized time-periodic harmonic oscillator is studied by finding the exact action variable (invariant). Hannay's angle is defined if closed curves of constant action variables return to the same curves in phase space after a time evolution. The condition for the existence of Hannay's angle turns out to be identical to that for the existence of a complete set of (quasi)periodic wave functions. Hannay's angle is calculated, and it is shown that Berry's relation of semiclassical origin on geometric phase and Hannay's angle is exact for the cases considered.Comment: Submitted to Phys. Rev. Lett. (revised version

Complications of Treated Cushing\u27s Syndrome

Fifty-two patients with Cushing\u27s syndrome are reported with emphasis on post treatment complications. Seven patients, cured of their disease following appropriate therapy, had a recurrence of adrenal hypersecretion from one to ten years later. This occurred after all modalities of treatment, but was more common after sub-total adrenalectomy. Pituitary adenomas were found in two cases. Pseudotumor cerebri, psychiatnc complications, hyperthyroidism and hyperpigmentation were observed. One patient developed progressive hyperplgmentation despite pituitary radiation. Thirteen of fifty-two patients had malignant disease including three endometrial carcinomas, one rectal carcinoma and one adenocarcinoma of the mandible. Despite the remarkable improvement In the prognosis for patients with Cushing\u27s syndrome, this population continues to be at high risk for late complications and warrants close follow-up medical care

Mass spectrometric gas composition measurements associated with jet interaction tests in a high-enthalpy wind tunnel

Knowledge of test gas composition is important in wind-tunnel experiments measuring aerothermodynamic interactions. This paper describes measurements made by sampling the top of the test section during runs of the Langley 7-Inch High-Temperature Tunnel. The tests were conducted to determine the mixing of gas injected from a flat-plate model into a combustion-heated hypervelocity test stream and to monitor the CO2 produced in the combustion. The Mass Spectrometric (MS) measurements yield the mole fraction of N2 or He and CO2 reaching the sample inlets. The data obtained for several tunnel run conditions are related to the pressures measured in the tunnel test section and at the MS ionizer inlet. The apparent distributions of injected gas species and tunnel gas (CO2) are discussed relative to the sampling techniques. The measurements provided significant real-time data for the distribution of injected gases in the test section. The jet N2 diffused readily from the test stream, but the jet He was mostly entrained. The amounts of CO2 and Ar diffusing upward in the test section for several run conditions indicated the variability of the combustion-gas test-stream composition

Spectral, mineralogical, and geochemical variations across Home Plate, Gusev Crater, Mars indicate high and low temperature alteration

Over the last ~ 3 years in Gusev Crater, Mars, the Spirit rover observed coherent variations in color, mineralogy, and geochemistry across Home Plate, an ~ 80 m-diameter outcrop of basaltic tephra. Observations of Home Plate from orbit and from the summit of Husband Hill reveal clear differences in visible/near-infrared (VNIR) colors between its eastern and western regions that are consistent with mineralogical compositions indicated by Mössbauer spectrometer (MB) and by Miniature Thermal Emission Spectrometer (Mini-TES). Pyroxene and magnetite dominate the east side, while olivine, nanophase Fe oxide (npOx) and glass are more abundant on the western side. Alpha Particle X-Ray Spectrometer (APXS) observations reveal that eastern Home Plate has higher Si/Mg, Al, Zn, Ni, and K, while Cl and Br are higher in the west. We propose that these variations are the result of two distinct alteration regimes that may or may not be temporally related: a localized, higher temperature recrystallization and alteration of the east side of Home Plate and lower temperature alteration of the western side that produced npOx