Library Economic Metrics: Examples of the Comparison of Electronic and Print Journal Collections and Collection Services

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Comparison of speech intelligibility in cockpit noise using SPH-4 flight helmet with and without active noise reduction

Active Noise Reduction (ANR) is a new technology which can reduce the level of aircraft cockpit noise that reaches the pilot's ear while simultaneously improving the signal to noise ratio for voice communications and other information bearing sound signals in the cockpit. A miniature, ear-cup mounted ANR system was tested to determine whether speech intelligibility is better for helicopter pilots using ANR compared to a control condition of ANR turned off. Two signal to noise ratios (S/N), representative of actual cockpit conditions, were used for the ratio of the speech to cockpit noise sound pressure levels. Speech intelligibility was significantly better with ANR compared to no ANR for both S/N conditions. Variability of speech intelligibility among pilots was also significantly less with ANR. When the stock helmet was used with ANR turned off, the average PB Word speech intelligibility score was below the Normally Acceptable level. In comparison, it was above that level with ANR on in both S/N levels

Circular 73

An assessment of Growth of Infrastructure Booms have been a common element in the development of frontier areas in the 19th and 20th centuries. Most commonly, the booms have been associated with resource development such as the mineral booms of the western United States. Booms usually involve some type of dramatic short- term change which has wide-ranging implications (Gilmore, 1976). Since the arrival of the Russians in Alaska, six major booms have occurred: furs, whales, salmon, minerals, military, and petroleum. Each of these booms has, to some degree, created changes in the landscape of Alaska, in particular, the infrastructural base, which in turn has facilitated subsequent development, either another major boom, or a smaller development. For example, agricultural development has been enhanced by mineral, military, and petroleum booms in Alaska. The cumulative impact on infrastructure of more than one boom, or multibooms, as it is referred to here, is the focus of this paper. One problem encountered in studying booms is that there is no general agreement on what constitutes a boom. Detailed studies of booms in communities such as Dixon’s (1978) analysis of Fairbanks and Gilmore’s multi-community work in the Great Plains—Rocky •mountain regions, contained no specific definition of the term “boom”. Yet it was clear in each study that something dramatic had occurred. More general historical studies of the Western mineral bonanzas (Greever, 1963) or the Klondike gold rush (Berton, 1958) likewise suggest a number of factors such as population rise, influx of money, resource extraction, and infrastructure expansion. But in each case, there is no specific factor or define rate of something that specifically qualifies a time period as a boom. In this study, we are concerned with dramatic change of events which have had a major impact on the geographic landscape of an area, As a framework for the initial study, we review those events which have been given attention as boom-type activities in the historical literature of Alaska (Rogers, 1962; Naske and Slotnick, 1987)

A study of the interprofessional relations of social workers with physicians, psychiatrists, psychologists and clergymen.

Thesis (M.S.)--Boston Universit

Bulk metallic glass formation in binary Cu-rich alloy series – Cu100−xZrx (x=34, 36, 38.2, 40 at.%) and mechanical properties of bulk Cu64Zr36 glass

The compositional dependence of a glass-forming ability (GFA) was systematically studied in a binary alloy series Cu100−xZrx (x=34, 36, 38.2, 40 at.%) by the copper mold casting method. Our results show the critical casting thickness jumps from below 0.5 mm to above 2 mm when x changes from 34 to 36 while further increase in x reduces the critical casting thickness. The best glass former Cu64Zr36 does not correspond to either the largest undercooled liquid region (ΔT=Tx1−Tg, where Tg is the glass transition temperature, and Tx1 is the onset temperature of the first crystallization event upon heating) or the highest reduced glass transition temperature (Trg=Tg/Tl, where Tl is the liquidus temperature). Properties of bulk amorphous Cu64Zr36 were measured, yielding a Tg ~ 787 K, Trg ~ 0.64, ΔT ~ 46 K, Hv (Vicker's Hardness) ~ 742 kg/mm^2, Young's Modulus ~ 92.3 GPa, compressive fracture strength ~ 2 GPa and compressive strain before failure ~ 2.2%

Off-diagonal hyperfine interaction between the 6p1/2 and 6p3/2 levels in 133Cs

The off-diagonal hyperfine interaction between the 6p1/2 and 6p3/2 states in 133Cs is evaluated in third-order MBPT giving 37.3 Hz and 48.3 Hz, respectively, for second-order energies of the 6p3/2 F=3 and F=4 levels. This result is a factor of 10 smaller than one obtained from an uncorrelated first-order Dirac-Hartree-Fock calculation and used in the analysis of a recent high-precision (< 2 kHz) measurement of the 6p3/2 hyperfine structure [Gerginov et al. Phys. Rev. Lett. 91, 72301 (2003)]. The factor of 10 difference has negligible effect on the conclusions of the recent experiment but will become important for experiments carried out at a precision of better than 1 kHz

Characteristics of UGC galaxies detected by IRAS

Infrared Astronomy Satellite (IRAS) detection rates at 60 microns were determined for the Uppsala General Catalog of Galaxies (Nilson 1973; the UCG). Late-type spirals, characterized by a normal IR/B ratio of approximately 0.6, are detected to a velocity of approximately 6000 km/s for L sub B = L sub *. Contrary to the situation for IRAS-selected galaxy samples, little evidence was found for a correlation between IR/B and 60/100 microns in this large optically-selected sample. Thus a significant fraction of the IRAS-measured far-infrared flux from normal spirals must originate in the diffuse interstellar medium, heated by the interstellar radiation field. Support was not found for Burstein and Lebofsky's (1986) conclusion that spiral disks are optically thick in the far-infrared