249 research outputs found
“The Whole Vexed Question”: Seamus Heaney, Old English and Language Troubles
As an Irish poet writing during the twentieth century, Seamus Heaney is constantly aware of the politics and problems of operating in the English language. My project locates Heaney in a context of writers and theorists who are similarly interested in the politics of language-ownership and the logistics of communication and expression in a major language. I argue that Heaney’s North presents a unique solution to these common language questions, and that the poet’s focus on etymologies and language history makes his escape into linguistic nonaffiliation more feasible than other, more abstract attempts at a borderless, liberated language
“The Whole Vexed Question”: Seamus Heaney, Old English and Language Troubles
As an Irish poet writing during the twentieth century, Seamus Heaney is constantly aware of the politics and problems of operating in the English language. My project locates Heaney in a context of writers and theorists who are similarly interested in the politics of language-ownership and the logistics of communication and expression in a major language. I argue that Heaney’s North presents a unique solution to these common language questions, and that the poet’s focus on etymologies and language history makes his escape into linguistic nonaffiliation more feasible than other, more abstract attempts at a borderless, liberated language
Flight evaluation of a simple total energy-rate system with potential wind-shear application
Wind shears can create havoc during aircraft terminal area operations and have been cited as the primary cause of several major aircraft accidents. A simple sensor, potentially having application to the wind-shear problem, was developed to rapidly measure aircraft total energy relative to the air mass. Combining this sensor with either a variometer or a rate-of-climb indicator provides a total energy-rate system which was successfully applied in soaring flight. The measured rate of change of aircraft energy can potentially be used on display/control systems of powered aircraft to reduce glide-slope deviations caused by wind shear. The experimental flight configuration and evaluations of the energy-rate system are described. Two mathematical models are developed: the first describes operation of the energy probe in a linear design region and the second model is for the nonlinear region. The calculated total rate is compared with measured signals for many different flight tests. Time history plots show the tow curves to be almost the same for the linear operating region and very close for the nonlinear region
Controlling the Frequency-Temperature Sensitivity of a Cryogenic Sapphire Maser Frequency Standard by Manipulating Fe3+ Spins in the Sapphire Lattice
To create a stable signal from a cryogenic sapphire maser frequency standard,
the frequency-temperature dependence of the supporting Whispering Gallery mode
must be annulled. We report the ability to control this dependence by
manipulating the paramagnetic susceptibility of Fe3+ ions in the sapphire
lattice. We show that the maser signal depends on other Whispering Gallery
modes tuned to the pump signal near 31 GHz, and the annulment point can be
controlled to exist between 5 to 10 K depending on the Fe3+ ion concentration
and the frequency of the pump. This level of control has not been achieved
previously, and will allow improvements in the stability of such devices.Comment: 17 pages, 10 figure
Evaluation of a total energy-rate sensor on a transport airplane
A sensor that measures the rate of change of total energy of an airplane with respect to the airstream has been evaluated. The sensor consists of two cylindrical probes located on the fuselage of a transport airplane, an in line acoustic filter, and a pressure sensing altitude rate transducer. Sections of this report include the sensor description and experimental configuration, frequency response tests, analytical model development, and flight test results for several airplane maneuvers. The results section includes time history comparisons between data generated by the total energy rate sensor and calculated data derived from independent sources
Improved cryogenic resin/glass-filament-wound composites Interim report, 29 Jun. 1965 - 28 Mar. 1966
Interlaminar-shear testing of resin-filament wound composite materials for cryogenic us
Expansion of CD16-Negative Natural Killer Cells in the Peripheral Blood of Patients with Metastatic Melanoma
Altered natural killer (NK) cell function is a component of the global immune dysregulation that occurs in advanced malignancies. Another condition associated with altered NK homeostasis is normal pregnancy, where robust infiltration with CD16− CD9+ NK cells can be identified in decidual tissues, along with a concomitant expansion of CD16− NK cells in the maternal peripheral blood. In metastatic melanoma, we identified a similar expansion of peripheral blood CD16− NK cells (median 7.4% in 41 patients with melanoma compared with 3.0% in 29 controls, P < .001). A subset of NK cells in melanoma patients also expresses CD9, which is characteristically expressed only on NK cells within the female reproductive tract. Expansion of CD16− NK cells was associated with elevated plasma transforming growth factor-beta (TGF-β levels (median 20 ng/ml, Spearman's ρ = 0.81, P = .015)). These findings suggest the possibility of exploring anti-TGF-β therapy to restore NK function in melanoma
Evaluating the Environmental Performance of the U.S. Next Generation Air Transportation System
The environmental impacts of several possible U.S. Next Generation Air Transportation scenarios have been quantitatively evaluated for noise, air-quality, fuel-efficiency, and CO2 impacts. Three principal findings have emerged. (1) 2025 traffic levels about 30% higher than 2006 are obtained by increasing traffic according to FAA projections while also limiting traffic at each airport using reasonable ratios of demand to capacity. NextGen operational capabilities alone enable attainment of an additional 10-15% more flights beyond that 2025 baseline level with negligible additional noise, air-quality, and fuel-efficiency impacts. (2) The addition of advanced engine and airframe technologies provides substantial additional reductions in noise and air-quality impacts, and further improves fuel efficiency. 2025 environmental goals based on projected system-wide improvement rates of about 1% per year for noise and fuel-efficiency (an air-quality goal is not yet formulated) are achieved using this new vehicle technology. (3) Overall air-transport "product", as measured by total flown distance or total payload distance, increases by about 50% relative to 2006, but total fuel consumption and CO2 production increase by only about 40% using NextGen operational capabilities. With the addition of advanced engine/airframe technologies, the increase in total fuel consumption and CO2 production can be reduced to about 30%
Measurement of fundamental thermal noise limit in a cryogenic sapphire frequency standard using bimodal maser oscillations
We report observations of the Schawlow-Townes noise limit in a cryogenic
sapphire secondary frequency standard. The effect causes a fundamental limit to
the frequency stability, and was measured through the novel excitation of a
bimodal maser oscillation of a Whispering Gallery doublet at . The
beat frequency of between the oscillations enabled a sensitive probe
for this measurement of fractional frequency instability of
with only 0.5 of output power.Comment: Published in PRL 100, 233901 (2008
Phase transformation-induced superconducting aluminium-silicon alloy rings
The development of a materials platform that exhibits both superconducting
and semiconducting properties is an important endeavour for a range of emerging
quantum technologies. We investigate the formation of superconductivity in
nanowires fabricated with silicon-on-insulator (SOI). Aluminium from deposited
contact electrodes is found to interdiffuses with the Si nanowire structures to
form an Al-Si alloy along the entire length of the predefined nanowire device
over micron length scales at temperatures well below that of the Al-Si
eutectic. The resultant transformed nanowire structures are layered in geometry
with a continuous Al-Si alloy wire sitting on the buried oxide of the SOI and a
residual Si cap sitting on top of the wire. The phase transformed material is
conformal with any predefined device patterns and the resultant structures are
exceptionally smooth-walled compared to similar nanowire devices formed by
silicidation processes. The superconducting properties of a mesoscopic AlSi
ring formed on a SOI platform are investigated. Low temperature
magnetoresistance oscillations, quantized in units of the fluxoid, h/2e, are
observed.Comment: 11 pages, 9 figure
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