631 research outputs found

    Response to actual and simulated recordings of conventional takeoff and landing jet aircraft

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    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

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    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

    New measurements of total ionizing dose in the lunar environment

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    [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

    Developing Berkshire Market Pig Growth Curves

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    Several factors have stimulated interest in an old, rather minor swine breed, Berkshire pigs. Berkshires produce pork that is darker, with more intramuscular fat than most swine breeds and lines currently. As the majority of modern pigs were genetically selected to be leaner, the Berkshire breed has continued to produce more flavorful pork. Asian consumers, especially Japanese, prefer and will pay a premium for Berkshire pork. American chefs and discriminating consumers request Berkshire pork, a strong market demand that has caused a flourish in the pork niche market largely centered around pork from Berkshirebred pigs. Some Iowa pork producers are raising Berkshire or Berkshire-cross pigs exclusively for export and niche markets. Several Berkshire niche markets and marketers are currently active in Iowa. Many of these markets require that the pigs must be reared in bedded or outdoor settings. A popular housing system used in Iowa is the bedded hoop barn

    Lean and Fat Deposition Measurements for Purebred Berkshire Pigs Housed in Hoop Barns in Iowa

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    Previous research on meat quality of pork has demonstrated that purebred Berkshires have advantages over most commodity based pork. Therefore a Certified Berkshire Pork program has developed and is a vital niche market in Iowa and the United States that provides economic opportunity for a growing number of producers. This research has also documented that Berkshires have a significantly poorer feed conversion than other breeds, thus raising their cost of production. Understanding how feed programs and growth rates affect lean and fat deposition rates is a critical aspect to these niche programs in order to maximize profitability and quality of the Berkshire pork products marketed. From these two trials there are differences between the two trials for both barrows and gilts that may not be accounted for by seasonal affects. Overall, barrows averaged an inch of backfat between 200 and 240 lb body weight whereas gilts approached this backfat depth between 260 and 300 lb. Lean deposition rates were different between barrows and gilts and between trials. This difference makes it critical when selecting animals for marketing and achieving consistency in meat quality within a marketing system. The differences between barrows and gilts indicate it may be more critical that each are fed differently than in commercial production systems

    Feed Intake and Growth Rate in Purebred Berkshire Pigs Housed in Hoop Buildings in Iowa

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    Niche marketing continues to grow in Iowa and the United States as the demand for high quality pork increases for both in home and out of home consumption. The majority of pigs in demand for these markets are Berkshires, with many raised in bedded hoop barns. Berkshires have been shown to have significant advantages in meat eating quality, with significantly poorer feed conversion and higher feed costs. However very little information exists as to how these pigs grow and the nutritional needs to optimize both growth and feed efficiency. Producers have little production data to evaluate and adjust feeding programs. These trials were initiated to help characterize these parameters and allow Berkshire producers a means to be more effective within their production and marketing system. This trial demonstrated that Berkshire pigs grow as fast but consume more feed than expected from traditional commodity genetic lines, resulting in a challenging feed conversion ratio. Barrows grow faster, consumed more feed than gilts, but gilts were more efficient converting feed to gain. Although seasonal feed intakes differ for both sexes, growth rates were similar within gilts and barrows. This information can perhaps be used in designing rations and feed budgeting systems that can lower the feed costs for production of Berkshire pork

    School librarians as literacy educators within a complex role

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    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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