658 research outputs found
Response to actual and simulated recordings of conventional takeoff and landing jet aircraft
Comparability between noise characteristics of synthesized recordings of aircraft in flight and actual recordings were investigated. Although the synthesized recordings were more smoothly time-varying than the actual recordings and the synthesizer could not produce a comb-filter effect that was present in the actual recordings, results supported the conclusion that annoyance response is comparable to the synthesized and actual recordings. A correction for duration markedly improved the validity of engineering calculation procedures designed to measure noise annoyance. Results led to the conclusion that the magnitude estimation psychophysical method was a highly reliable approach for evaluating engineering calculation procedures designed to measure noise annoyance. For repeated presentations of pairs of actual recordings, differences between judgment results for identical signals ranged from 0.0 to 0.5 db
A study of noise metric and tone correction accuracy
Methods currently used to measure human response to aircraft flyover noise were investigated. Response to high level aircraft noise usually experienced outdoors was obtained. Response to aircraft flyover noise typical of indoor exposure was also investigated. It was concluded that current methods for evaluating response to aircraft flyover are more accurate for outdoor noise
A study of general aviation community noise impact and annoyance
The method involved the selection of three airports which were dominated by aircraft weighing 12,500 lbs or under and which were also undergoing a change relative to utilization. Also, there was interest in airports with different utilization levels so that effect of number of operations could be considered. In addition, there was a requirement to select airports with communities in the surrounding areas which were exposed to aircraft operations noise. Noise annoyance response data was obtained from available sources. These sources included environmental impact statements, interviews with airport managers, noise complaint information, community meetings concerned with projected changes in airport utilization, and social survey data. As a means of objectively assessing the noise impact due to aircraft operations, noise measurement and computer noise modeling determinations were obtained for each airport. Listening quality tape recordings were also obtained
New measurements of total ionizing dose in the lunar environment
[1] We report new measurements of solar minimum ionizing radiation dose at the Moon onboard the Lunar Reconnaissance Orbiter (LRO) from June 2009 through May 2010. The Cosmic Ray Telescope for the Effects of Radiation (CRaTER) instrument on LRO houses a compact and highly precise microdosimeter whose design allows measurements of dose rates below 1 micro-Rad per second in silicon achieved with minimal resources (20 g, ∼250 milliwatts, and ∼3 bits/second). We envision the use of such a small yet accurate dosimeter in many future spaceflight applications where volume, mass, and power are highly constrained. As this was the first operation of the microdosimeter in a space environment, the goal of this study is to verify its response by using simultaneous measurements of the galactic cosmic ray ionizing environment at LRO, at L1, and with other concurrent dosimeter measurements and model predictions. The microdosimeter measured the same short timescale modulations in the galactic cosmic rays as the other independent measurements, thus verifying its response to a known source of minimum-ionizing particles. The total dose for the LRO mission over the first 333 days was only 12.2 Rads behind ∼130 mils of aluminum because of the delayed rise of solar activity in solar cycle 24 and the corresponding lack of intense solar energetic particle events. The dose rate in a 50 km lunar orbit was about 30 percent lower than the interplanetary rate, as one would expect from lunar obstruction of the visible sky
Self-assembly of magnetic biofunctional nanoparticles
Spherical, ferromagnetic FePt nanoparticles with a particle size of 3 nm were prepared by the simultaneous polyol reduction of Fe(acac)3Fe(acac)3 and Pt(acac)2Pt(acac)2 in phenyl ether in the presence of oleic acid and oleylamine. The oleic acid ligands can be replaced with 11-mercaptoundecanoic acid, giving particles that can be dispersed in water. Both x-ray diffraction and transmission electron microscopy indicated that FePt particles were not affected by ligands replacement. Dispersions of the FePt particles with 11-mercaptoundecanoic acid ligands and ammonium counter ions gave self-assembled films consisting of highly ordered hexagonal arrays of particles.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87511/2/10Q901_1.pd
Light noble gas composition of different solar wind regimes: results from genesis
The Genesis mission provided samples of solar wind
(SW) from different regions on the Sun. These SW regime samples are
important in understanding fractionation processes upon formation and
acceleration of the SW to ultimately deduce solar composition from SW
values. We present He and Ne isotopic and elemental compositions of the
bulk SW (SW of entire collection period) and the 3 major SW regimes: slow
(from the ecliptic plane, emanating from above streamers), fast (emanating
from coronal holes), and coronal mass ejections (CME). At the conference
we will also present Ar data
Mass-fractionation induced by the Genesis solar wind concentrator: Analysis of neon isotopes by UV laser ablation
The solar wind (SW) concentrator, a key instrument onboard the
Genesis mission, was designed to provide larger fluences of implanted SW
for precise isotope analyses of oxygen and nitrogen [1]. SW ions in the mass
range 4–28 amu were accelerated and focused on a “concentrator target” by
an electrostatic mirror. This concentration process caused some instrumental
mass fractionation of the implanted SW ions as function of the radial position
on the target. Correction of this fractionation will be based on a combination
of the measured radial fractionation of Ne isotopes with results of simulations
of the implantation process using the actual performance of the concentrator
and the SW conditions during exposure. Here we present He and Ne
abundance and Ne isotopic composition data along one arm of the gold cross
that framed the 4 concentrator subtargets
School librarians as literacy educators within a complex role
Librarians in schools are expected to play an important role as literacy educators, and have a positive impact on young people’s literacy learning. However in the context of their diverse workload, relatively little is known about how this aspect of their role sits within its competing demands, and the exact scope of the literacy educator requirements. Using a hybrid approach to content analysis, this article analyses 40 recent job description documents to identify the nature and prevalence of different aspects of the role, and to explore the literacy educator aspect of this profession. Findings suggest that while the literacy educator aspect is one of the most common role requirements, it sits within a complex workload, and the literacy educator aspect is itself multi-faceted and demanding
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Carbon stable isotope analysis of cereal remains as a way to reconstruct water availability: preliminary results
Reconstructing past water availability, both as rainfall and irrigation, is important to answer questions about the way society reacts to climate and its changes and the role of irrigation in the development of social complexity. Carbon stable isotope analysis of archaeobotanical remains is a potentially valuable method for reconstructing water availability. To further define the relationship between water availability and plant carbon isotope composition and to set up baseline values for the Southern Levant, grains of experimentally grown barley and sorghum were studied. The cereal crops were grown at three stations under five different irrigation regimes in Jordan. Results indicate that a positive but weak relationship exists between irrigation regime and total water input of barley grains, but no relationship was found for sorghum. The relationship for barley is site-specific and inter-annual variation was present at Deir ‘Alla, but not at Ramtha and Khirbet as-Samra
Solar neon released from Genesis aluminum collector duriung stepped uv-laser extraction and step-wise pyrolysis
Earlier this year we reported results of UV-laser stepped raster extractions of Ne and He from Genesis' Al-collector [l]. Since then, using pyrolysis of a 0.005 cm^2 fragment of this material left from the earlier study, we have estimated the efficiency of the UV-laser extraction to be at least 95%. We also analyzed Ne released from the Al-collector by means of stepped pyrolysis. Here we compare these new data with stepped UV-laser extraction and the CSSE results [2]. Figure 1 shows the ^(20)Ne/^(22)Ne ratio extracted from Genesis collectors using these three techniques
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