1,192 research outputs found
Forward (from NDE Education/Training for Engineers )
In 1980 the Materials and Fabrication Committee of the American Society of Engineers, Pressure Vessel and Piping Division, conducted a symposium entitled, Critical Issues in Materials and Mechanical Engineering (1). The purpose of this symposium was to identify those engineering issues which affect the future of ASME and the public at large. One of the critical issues defined and unanimously endorsed by this symposium was the reliability of nondestructive evaluation (NDE). In his statement of the issue, Mordfin pointed out that ... reliable NDE, performed during fabrication and in service, can enhance safety, increase durability, improve performance, and reduce life cycle costs ... He further added that these benefits cannot be achieved without reliable NDE tools, and that reliability itself is a very complex issue that embraces many facets of technology and human skills. Examples of some of the technological facets include the research and development leading to more reliable NDE instrumentation and interpretive signal processing algorithms, the utilization of these advances in the design of NDE systems with predictable and quantifiable performance reliability, and the strong interfacing of NDE with design, materials processing, manufacturing, and maintenance functions that must yet be developed. Human factors that improve reliability are more difficult to define, but certainly include the level of education and training of personnel as well as a number of intangibles that constitute the motivational environment. Burley noted that an important overlying motivational element is management attitude. Reliability in NDE requires an expressed management philosophy that NDE is essential to improved quality and service life of components fabricated from a variety of materials
Accelerating the Production and Application of Evidence for Public Health System Improvement: the Search for New Frontiers
The new journal Frontiers in Public Health Services and Systems Research provides a platform for rapidly and widely communicating emerging findings and lessons learned from studies of public health services and delivery systems
Sensory Impact of Extended Maceration and Regulated Deficit Irrigation on Washington State Cabernet Sauvignon Wines
Irrigation practices such as regulated deficit irrigation (RDI) and winemaking practices such as extended maceration have been experimentally evaluated from a chemical perspective but their impacts on sensory composition and interactive effects merit scientific attention. This study evaluated the sensory impact of extended maceration applied to Cabernet Sauvignon grapes sourced from a vineyard subjected to four RDI treatments: replenishment of 100%, 70%, and 25% of full-vine crop evapotranspiration (ETc) from fruit set until veraison followed by 100% ETc until harvest (labeled 100% ETc, 70% ETc, and 25% ETc, respectively) and 25% ETc from fruit set to veraison followed by 100% ETc from veraison to harvest (labeled 25/100% ETc). Each RDI treatment was replicated four times (n = 4) and made into wine, with two replicates designated as controls (10 day skin contact) and two as extended maceration (30 day skin contact). Wines were evaluated by descriptive analysis with a trained panel (n = 15) and chemical and sensory data were correlated using canonical correlation analysis. Wine-perceived saturation and purple component ratings were highest in 25% ETc wines and were highly correlated with the concentration of flavonols, malvidin- and delphinidin-derivatives, and small polymeric pigments. Fruit-based aroma descriptors were highest in the 25/100% ETc and 70% ETc wines. Extended maceration increased perceived astringency and bitterness, which were in turn correlated with the concentration of flavan-3-ol and oligomeric proanthocyanidins. These results suggest that moderate RDI protocols such as 70% ETc and 25/100% ETc impact positively the fruity aroma component (black and red fruit), whereas extended maceration lowered fruity aromas, possibly due to the masking effect of the oxidized character perceived in these wines.EEA MendozaFil: Casassa, Luis Federico. Washington State University. Irrigated Agriculture Research and Extension Center. School of Food Science; Estados Unidos. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza. Centro de Estudios de Enología; Argentina.Fil: Larsen, Richard C. Washington State University. Viticulture and Enology Program; Estados UnidosFil: Beaver, Christopher W. Washington State University. Irrigated Agriculture Research and Extension Center. School of Food Science; Estados UnidosFil: Mireles, María S. Washington State University. Irrigated Agriculture Research and Extension Center. School of Food Science; Estados UnidosFil: Keller, Markus. Washington State University. Department of Horticulture; Estados UnidosFil: Riley, William R. Ste. Michelle Wine Estates; Estados UnidosFil: Smithyman, Russell. Ste. Michelle Wine Estates; Estados UnidosFil: Harbertson, James F. Washington State University. Irrigated Agriculture Research and Extension Center. School of Food Science; Estados Unido
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A Mechanistic Treatment of the Dominant Soil Nitrogen Cycling Processes: Model Development, Testing, and Application
The development and initial application of a mechanistic model (TOUGHREACT-N) designed to characterize soil nitrogen (N) cycling and losses are described. The model couples advective and diffusive nutrient transport, multiple microbial biomass dynamics, and equilibrium and kinetic chemical reactions. TOUGHREACT-N was calibrated and tested against field measurements to assess pathways of N loss as either gas emission or solute leachate following fertilization and irrigation in a Central Valley, California, agricultural field as functions of fertilizer application rate and depth, and irrigation water volume. Our results, relative to the period before plants emerge, show that an increase in fertilizer rate produced a nonlinear response in terms of N losses. An increase of irrigation volume produced NO{sub 2}{sup -} and NO{sub 3}{sup -} leaching, whereas an increase in fertilization depth mainly increased leaching of all N solutes. In addition, nitrifying bacteria largely increased in mass with increasing fertilizer rate. Increases in water application caused nitrifiers and denitrifiers to decrease and increase their mass, respectively, while nitrifiers and denitrifiers reversed their spatial stratification when fertilizer was applied below 15 cm depth. Coupling aqueous advection and diffusion, and gaseous diffusion with biological processes, closely captured actual conditions and, in the system explored here, significantly clarified interpretation of field measurements
The 1.6 micron near infrared nuclei of 3C radio galaxies: Jets, thermal emission or scattered light?
Using HST NICMOS 2 observations we have measured 1.6-micron near infrared
nuclear luminosities of 100 3CR radio galaxies with z<0.3, by modeling and
subtracting the extended emission from the host galaxy. We performed a
multi-wavelength statistical analysis (including optical and radio data) of the
properties of the nuclei following classification of the objects into FRI and
FRII, and LIG (low-ionization galaxies), HIG (high-ionization galaxies) and BLO
(broad-lined objects) using the radio morphology and optical spectra,
respectively. The correlations among near infrared, optical, and radio nuclear
luminosity support the idea that the near infrared nuclear emission of FRIs has
a non-thermal origin. Despite the difference in radio morphology, the
multi-wavelength properties of FRII LIG nuclei are statistically
indistinguishable from those of FRIs, an indication of a common structure of
the central engine. All BLOs show an unresolved near infrared nucleus and a
large near infrared excess with respect to FRII LIGs and FRIs of equal radio
core luminosity. This requires the presence of an additional (and dominant)
component other than the non-thermal light. Considering the shape of their
spectral energy distribution, we ascribe the origin of their near infrared
light to hot circumnuclear dust. A near infrared excess is also found in HIGs,
but their nuclei are substantially fainter than those of BLO. This result
indicates that substantial obscuration along the line-of-sight to the nuclei is
still present at 1.6 micron. Nonetheless, HIGs nuclei cannot simply be
explained in terms of dust obscuration: a significant contribution from light
reflected in a circumnuclear scattering region is needed to account for their
multiwavelength properties.Comment: 20 pages, 16 figures. Accepted for publication on Ap
Encouraging Medicare Advantage Enrollees to Switch to Higher Quality Plans: Assessing the Effectiveness of a ‘‘Nudge’’ Letter
There are considerable quality differences across private Medicare Advantage insurance plans, so it is important that beneficiaries make informed choices. During open enrollment for the 2013 coverage year, the Centers for Medicare & Medicaid Services sent letters to beneficiaries enrolled in low-quality Medicare Advantage plans (i.e., plans rated less than 3 stars for at least 3 consecutive years by Medicare) explaining the stars and encouraging them to reexamine their choices. To understand the effectiveness of these low-cost, behavioral ‘‘nudge’’ letters, we used a beneficiary-level national retrospective cohort and performed multivariate regression analysis of plan selection during the 2013 open enrollment period among those enrolled in plans rated less than 3 stars. Our analysis controls for beneficiary demographic characteristics, health and health care spending risks, the availability of alternative higher rated plan options in their local market, and historical disenrollment rates from the plans. We compared the behaviors of those beneficiaries who received the nudge letters with those who enrolled in similar poorly rated plans but did not receive such letters. We found that beneficiaries who received the nudge letter were almost twice as likely (28.0% [95% confidence interval = 27.7%, 28.2%] vs. 15.3% [95% confidence interval = 15.1%, 15.5%]) to switch to a higher rated plan compared with those who did not receive the letter. White beneficiaries, healthier beneficiaries, and those residing in areas with more high-performing plan choices were more likely to switch plans in response to the nudge. Our findings highlight both the importance and efficacy of providing timely and actionable information to beneficiaries about quality in the insurance marketplace to facilitate informed and value-based coverage decisions
Arctic tundra shrubification: a review of mechanisms and impacts on ecosystem carbon balance
Vegetation composition shifts, and in particular, shrub expansion across the Arctic tundra are some of the most important and widely observed responses of high-latitude ecosystems to rapid climate warming. These changes in vegetation potentially alter ecosystem carbon balances by affecting a complex set of soil-plant-atmosphere interactions. In this review, we synthesize the literature on (a) observed shrub expansion, (b) key climatic and environmental controls and mechanisms that affect shrub expansion, (c) impacts of shrub expansion on ecosystem carbon balance, and (d) research gaps and future directions to improve process representations in land models. A broad range of evidence, including in-situ observations, warming experiments, and remotely sensed vegetation indices have shown increases in growth and abundance of woody plants, particularly tall deciduous shrubs, and advancing shrublines across the circumpolar Arctic. This recent shrub expansion is affected by several interacting factors including climate warming, accelerated nutrient cycling, changing disturbance regimes, and local variation in topography and hydrology. Under warmer conditions, tall deciduous shrubs can be more competitive than other plant functional types in tundra ecosystems because of their taller maximum canopy heights and often dense canopy structure. Competitive abilities of tall deciduous shrubs vs herbaceous plants are also controlled by variation in traits that affect carbon and nutrient investments and retention strategies in leaves, stems, and roots. Overall, shrub expansion may affect tundra carbon balances by enhancing ecosystem carbon uptake and altering ecosystem respiration, and through complex feedback mechanisms that affect snowpack dynamics, permafrost degradation, surface energy balance, and litter inputs. Observed and projected tall deciduous shrub expansion and the subsequent effects on surface energy and carbon balances may alter feedbacks to the climate system. Land models, including those integrated in Earth System Models, need to account for differences in plant traits that control competitive interactions to accurately predict decadal- to centennial-scale tundra vegetation and carbon dynamics
Planetary Candidates Observed by Kepler VI: Planet Sample from Q1-Q16 (47 Months)
\We present the sixth catalog of Kepler candidate planets based on nearly 4
years of high precision photometry. This catalog builds on the legacy of
previous catalogs released by the Kepler project and includes 1493 new Kepler
Objects of Interest (KOIs) of which 554 are planet candidates, and 131 of these
candidates have best fit radii <1.5 R_earth. This brings the total number of
KOIs and planet candidates to 7305 and 4173 respectively. We suspect that many
of these new candidates at the low signal-to-noise limit may be false alarms
created by instrumental noise, and discuss our efforts to identify such
objects. We re-evaluate all previously published KOIs with orbital periods of
>50 days to provide a consistently vetted sample that can be used to improve
planet occurrence rate calculations. We discuss the performance of our planet
detection algorithms, and the consistency of our vetting products. The full
catalog is publicly available at the NASA Exoplanet Archive.Comment: 18 pages, to be published in the Astrophysical Journal Supplement
Serie
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Science Perspectives on the CCSP Strategic Plan
Scientists offer comments on the Climate Change Science Program Strategic Pla
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