Application of Earthquake Subspace Detectors at Kilauea and Mauna Loa Volcanoes, Hawai`i

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Okubo, P.; Benz, H.; Yeck, W.

2016-12-01

Recent studies have demonstrated the capabilities of earthquake subspace detectors for detailed cataloging and tracking of seismicity in a number of regions and settings. We are exploring the application of subspace detectors at the United States Geological Survey's Hawaiian Volcano Observatory (HVO) to analyze seismicity at Kilauea and Mauna Loa volcanoes. Elevated levels of microseismicity and occasional swarms of earthquakes associated with active volcanism here present cataloging challenges due the sheer numbers of earthquakes and an intrinsically low signal-to-noise environment featuring oceanic microseism and volcanic tremor in the ambient seismic background. With high-quality continuous recording of seismic data at HVO, we apply subspace detectors (Harris and Dodge, 2011, Bull. Seismol. Soc. Am., doi: 10.1785/0120100103) during intervals of noteworthy seismicity. Waveform templates are drawn from Magnitude 2 and larger earthquakes within clusters of earthquakes cataloged in the HVO seismic database. At Kilauea, we focus on seismic swarms in the summit caldera region where, despite continuing eruptions from vents in the summit region and in the east rift zone, geodetic measurements reflect a relatively inflated volcanic state. We also focus on seismicity beneath and adjacent to Mauna Loa's summit caldera that appears to be associated with geodetic expressions of gradual volcanic inflation, and where precursory seismicity clustered prior to both Mauna Loa's most recent eruptions in 1975 and 1984. We recover several times more earthquakes with the subspace detectors - down to roughly 2 magnitude units below the templates, based on relative amplitudes - compared to the numbers of cataloged earthquakes. The increased numbers of detected earthquakes in these clusters, and the ability to associate and locate them, allow us to infer details of the spatial and temporal distributions and possible variations in stresses within these key regions of the volcanoes.

1984 Mauna Loa eruption and planetary geolgoy

International Nuclear Information System (INIS)

Moore, H.J.

1987-01-01

In planetary geology, lava flows on the Moon and Mars are commonly treated as relatively simple systems. Some of the complexities of actual lava flows are illustrated using the main flow system of the 1984 Mauna Loa eruption. The outline, brief narrative, and results given are based on a number of sources. The implications of the results to planetary geology are clear. Volume flow rates during an eruption depend, in part, on the volatile content of the lava. These differ from the volume flow rates calculated from post eruption flow dimensions and the duration of the eruption and from those using models that assume a constant density. Mass flow rates might be more appropriate because the masses of volatiles in lavas are usually small, but variable and sometimes unknown densities impose severe restrictions on mass estimates

Constraining the timescale of magma stagnation beneath Mauna Kea volcano, Hawaii,using diffusion profiles in olivine phenocrysts

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Bloch, E. M.; Ganguly, J.

2009-12-01

Fe-Mg diffusion profiles have been measured in olivine xenocrysts within alkalic basalts in order to constrain the timescales of magma stagnation beneath Mauna Kea volcano, Hawaii. It has been suggested that during the main tholeiitic shield-building stage, and postshield eruptive stages of Mauna Kea, magmas were stalled and stagnated near the Moho, at a depth of ~15 km. Evidence in support of this hypothesis comes from cumulates formed by gravity-settling and in situ crystallization within magma chambers (Fodor and Galar, 1997), and from clinopyroxene-wholerock thermobarometry on Hamakua basalts (Putirka, in press). The cumulates represent a ‘fossil’ magma chamber which formed primarily from tholeiitic basalts; during the later capping-lava stage of Mauna Kea, alkalic basalts tore off chunks of these cumulates during ascent to the surface. We have measured several diffusion profiles in olivine xenocrysts from a single basalt sample. Because these xenocrysts have homogenous core compositions identical to a neighboring dunite cumulate, and because they are much larger and texturally distinct from compositionally dissimilar olivine phenocrysts, they are interpreted to be cumulate olivines which were dislodged during magma recharge/mixing in the stagnation zone. Although the orientations of the phenocrysts are not yet known, the diffusion profiles have been fit using diffusion coefficients parallel to the c and a crystallographic axes (i.e. minimum and maximum values). Modeling diffusion profiles yields ∫Ddt ≤4.5 x 10-5 cm2. Assuming that the xenocrysts were broken off from the cumulate immediately when the magma chamber was recharged, it is possible to calculate the maximum stagnation time of the basalts. Thus, the retrieved ∫Ddt value yields a maximum stagnation time of ~0.7 years. References: Fodor RV, Galar, PA (1997). A View into the Subsurface of Mauna Kea Volcano, Hawaii: Crystallization Processes Interpreted through the Petrology and Petrography of

Geologic map of the northeast flank of Mauna Loa volcano, Island of Hawai'i, Hawaii

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Trusdell, Frank A.; Lockwood, John P.

2017-05-01

SummaryMauna Loa, the largest volcano on Earth, has erupted 33 times since written descriptions became available in 1832. Some eruptions were preceded by only brief seismic unrest, while others followed several months to a year of increased seismicity.The majority of the eruptions of Mauna Loa began in the summit area (>12,000-ft elevation; Lockwood and Lipman, 1987); yet the Northeast Rift Zone (NERZ) was the source of eight flank eruptions since 1843 (table 1). This zone extends from the 13,680-ft-high summit towards Hilo (population ~60,000), the second largest city in the State of Hawaii. Although most of the source vents are farther than 30 km away, the 1880 flow from one of the vents extends into Hilo, nearly reaching Hilo Bay. The city is built entirely on flows erupted from the NERZ, most older than that erupted in 1843.Once underway, Mauna Loa's eruptions can produce lava flows that reach the sea in less than 24 hours, severing roads and utilities in their path. For example, lava flows erupted from the Southwest Rift Zone (SWRZ) in 1950 advanced at an average rate of 9.3 km per hour, and all three lobes reached the ocean within approximately 24 hours (Finch and Macdonald, 1953). The flows near the eruptive vents must have traveled even faster.In terms of eruption frequency, pre-eruption warning, and rapid flow emplacement, Mauna Loa poses an enormous volcanic-hazard threat to the Island of Hawai‘i. By documenting past activity and by alerting the public and local government officials of our findings, we can anticipate the volcanic hazards and substantially mitigate the risks associated with an eruption of this massive edifice.From the geologic record, we can deduce several generalized facts about the geologic history of the NERZ. The middle to the uppermost section of the rift zone were more active in the past 4,000 years than the lower part, perhaps due to buttressing of the lower east rift zone by Mauna Kea and Kīlauea volcanoes. The historical flows

Estimate of the biotic contribution to the atmospheric CO2 increase based on direct measurements at Mauna Loa Observatory

International Nuclear Information System (INIS)

Elliott, W.P.; Machta, L.; Keeling, C.D.

1985-01-01

The CO 2 concentrations recorded at Mauna Loa Observatory from 1958-1983 were examined to detect the existence of any significant sources of CO 2 other than fossil fuel combustion. The observed annual CO 2 concentrations were compared with concentrations calculated assuming a number of hypothetical constant, nonfossil fuel emission scenarios added to the fossil fuel emissions. It was found that constant nonfossil fuel sources must have been 10% or less of the fossil fuel sources. This conclusion assumes that a constant fraction of the total emissions went into the oceans and that the nonfossil fuel emissions were invariant from year to year. When this latter restriction was relaxed, almost any nonfossil fuel source was possible if its history closely matched that of the fossil fuel emissions. We conclude that it is unlikely that biotic or other nonfossil fuel sources could have exceeded about 0.5 GT of carbon per year except in the unlikely event that they grew at a rate close to that of the fossil fuel emissions

Variability of the 2014-present inflation source at Mauna Loa volcano revealed using time-dependent modeling

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Johanson, I. A.; Miklius, A.; Okubo, P.; Montgomery-Brown, E. K.

2017-12-01

Mauna Loa volcano is the largest active volcano on earth and in the 20thcentury produced roughly one eruption every seven years. The 33-year quiescence since its last eruption 1984 has been punctuated by three inflation episodes where magma likely entered the shallow plumbing system, but was not erupted. The most recent began in 2014 and is ongoing. Unlike prior inflation episodes, the current one is accompanied by a significant increase in shallow seismicity, a pattern that is similar to earlier pre-eruptive periods. We apply the Kalman filter based Network Inversion Filter (NIF) to the 2014-present inflation episode using data from a 27 station continuous GPS network on Mauna Loa. The model geometry consists of a point volume source and tabular, dike-like body, which have previously been shown to provide a good fit to deformation data from a 2004-2009 inflation episode. The tabular body is discretized into 1km x 1km segments. For each day, the NIF solves for the rates of opening on the tabular body segments (subject to smoothing and positivity constraints), volume change rate in the point source, and slip rate on a deep décollement fault surface, which is constrained to a constant (no transient slip allowed). The Kalman filter in the NIF provides for smoothing both forwards and backwards in time. The model shows that the 2014-present inflation episode occurred as several sub-events, rather than steady inflation. It shows some spatial variability in the location of the inflation sub-events. In the model, opening in the tabular body is initially concentrated below the volcano's summit, in an area roughly outlined by shallow seismicity. In October, 2015 opening in the tabular body shifts to be centered beneath the southwest portion of the summit and seismicity becomes concentrated in this area. By late 2016, the opening rate on the tabular body decreases and is once again under the central part of summit. This modeling approach has allowed us to track these

The Global Land-Ocean Temperature Index in Relation to Sunspot Number, the Atlantic Multidecadal Oscillation Index, the Mauna Loa Atmospheric Concentration of CO2, and Anthropogenic Carbon Emissions

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Wilson, Robert M.

2013-01-01

Global warming/climate change has been a subject of scientific interest since the early 19th century. In particular, increases in the atmospheric concentration of carbon dioxide (CO2) have long been thought to account for Earth's increased warming, although the lack of a dependable set of observational data was apparent as late as the mid 1950s. However, beginning in the late 1950s, being associated with the International Geophysical Year, the opportunity arose to begin accurate continuous monitoring of the Earth's atmospheric concentration of CO2. Consequently, it is now well established that the atmospheric concentration of CO2, while varying seasonally within any particular year, has steadily increased over time. Associated with this rising trend in the atmospheric concentration of CO2 is a rising trend in the surface-air and sea-surface temperatures (SSTs). This Technical Publication (TP) examines the statistical relationships between 10-year moving averages (10-yma) of the Global Land-Ocean Temperature Index (GLOTI), sunspot number (SSN), the Atlantic Multidecadal Oscillation (AMO) index, and the Mauna Loa CO2 (MLCO2) index for the common interval 1964-2006, where the 10-yma values are used to indicate trends in the data. Scatter plots using the 10-yma values between GLOTI and each of the other parameters are determined, both as single-variate and multivariate fits. Scatter plots are also determined for MLCO2 using single-variate and bivariate (BV) fits, based on the GLOTI alone and the GLOTI in combination with the AMO index. On the basis of the inferred preferential fits for MLCO2, estimates for MLCO2 are determined for the interval 1885-1964, thereby yielding an estimate of the preindustrial level of atmospheric concentration of CO2. Lastly, 10-yma values of MLCO2 are compared against 10-yma estimates of the total carbon emissions (TCE) to determine the likelihood that manmade sources of carbon emissions are indeed responsible for the recent warming now

Rover-Based Instrumentation and Scientific Investigations During the 2012 Analog Field Test on Mauna Kea Volcano, Hawaii

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Graham, L. D.; Graff, T. G.

2013-01-01

Rover-based 2012 Moon and Mars Analog Mission Activities (MMAMA) were recently completed on Mauna Kea Volcano, Hawaii. Scientific investigations, scientific input, and operational constraints were tested in the context of existing project and protocols for the field activities designed to help NASA achieve the Vision for Space Exploration [1]. Several investigations were conducted by the rover mounted instruments to determine key geophysical and geochemical properties of the site, as well as capture the geological context of the area and the samples investigated. The rover traverse and associated science investigations were conducted over a three day period on the southeast flank of the Mauna Kea Volcano, Hawaii. The test area was at an elevation of 11,500 feet and is known as "Apollo Valley" (Fig. 1). Here we report the integration and operation of the rover-mounted instruments, as well as the scientific investigations that were conducted.

Long-term response of the mamane forest to feral herbivore management on Mauna Kea, Hawaii

Science.gov (United States)

E. Reddy; D. H. Van Vuren; P. G. Scowcroft; J. B. Kauffman; L. Perry

2012-01-01

Seven exclosure sites located on Mauna Kea, Hawaii and established in the 1960s and 70s were sampled to characterize long-term response of the mamane (Sophora chrysophylla) forest to protection from feral sheep grazing, and to assess impacts of non-native plant species and recurrent sheep presence on forest recovery. The forest provides essential...

Three-dimensional seismic velocity structure of Mauna Loa and Kilauea volcanoes in Hawaii from local seismic tomography

Science.gov (United States)

Lin, Guoqing; Shearer, Peter M.; Matoza, Robin S.; Okubo, Paul G.; Amelung, Falk

2016-01-01

We present a new three-dimensional seismic velocity model of the crustal and upper mantle structure for Mauna Loa and Kilauea volcanoes in Hawaii. Our model is derived from the first-arrival times of the compressional and shear waves from about 53,000 events on and near the Island of Hawaii between 1992 and 2009 recorded by the Hawaiian Volcano Observatory stations. The Vp model generally agrees with previous studies, showing high-velocity anomalies near the calderas and rift zones and low-velocity anomalies in the fault systems. The most significant difference from previous models is in Vp/Vs structure. The high-Vp and high-Vp/Vs anomalies below Mauna Loa caldera are interpreted as mafic magmatic cumulates. The observed low-Vp and high-Vp/Vs bodies in the Kaoiki seismic zone between 5 and 15 km depth are attributed to the underlying volcaniclastic sediments. The high-Vp and moderate- to low-Vp/Vs anomalies beneath Kilauea caldera can be explained by a combination of different mafic compositions, likely to be olivine-rich gabbro and dunite. The systematically low-Vp and low-Vp/Vs bodies in the southeast flank of Kilauea may be caused by the presence of volatiles. Another difference between this study and previous ones is the improved Vp model resolution in deeper layers, owing to the inclusion of events with large epicentral distances. The new velocity model is used to relocate the seismicity of Mauna Loa and Kilauea for improved absolute locations and ultimately to develop a high-precision earthquake catalog using waveform cross-correlation data.

RESOLVE's Field Demonstration on Mauna Kea, Hawaii 2010

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Captain, Janine; Quinn, Jacqueline; Moss, Thomas; Weis, Kyle

2010-01-01

In cooperation with the Canadian Space Agency, and the Northern Centre for Advanced Technology, Inc., NASA has undertaken the In-Situ Resource Utilization (ISRU) project called RESOLVE (Regolith and Environment Science & Oxygen and Lunar Volatile Extraction). This project is an Earth-based lunar precursor demonstration of a system that could be sent to explore permanently shadowed polar lunar craters, where it would drill into regolith, quantify the volatiles that are present, and extract oxygen by hydrogen reduction of iron oxides. The resulting water could be electrolyzed into oxygen to support exploration and hydrogen, which would be recycled through the process. The RESOLVE chemical processing system was mounted on a Canadian Space Agency mobility chasis and successfully demonstrated on Hawaii's Mauna Kea volcano in February 2010. The RESOLVE unit is the initial prototype of a robotic prospecting mission to the Moon. RESOLVE is designed to go to the poles of the Moon to "ground truth" the form and concentration of the hydrogen/water/hydroxyl that has been seen from orbit (M3, Lunar Prospector and LRO) and to test technologies to extract oxygen from the lunar regolith. RESOLVE has the ability to capture a one-meter core sample of lunar regolith and heat it to determine the volatiles that may be released and then demonstrate the production of oxygen from minerals found in the regolith. The RESOLVE project, which is led by KSC, is a multi-center and multi-organizational effort that includes representatives from KSC, JSC, GRC, the Canadian Space Agency, and the Northern Center for Advanced Technology (NORCAT). This paper details the results obtained from four days of lunar analog testing that included gas chromatograph analysis for volatile components, remote control of chemistry and drilling operations via satalite communications, and real-time water quantification using a novel capacitance measurement technique.

Population estimates of the Endangered Hawaiʻi ʻĀkepa (Loxops coccineus) in different habitats on windward Mauna Loa

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Judge, Seth W.; Camp, Richard J.; Hart, Patrick J.; Kichman, Scott T.

2018-01-01

Endangered Hawai‘i ʻĀkepas (Loxops coccineus) are endemic to Hawai‘i island, where they occur in five spatially distinct populations. Data concerning the status and population trends of these unique Hawaiian honeycreepers are crucial for assessing the effectiveness of recovery and management actions. In 2016, we used point‐transect distance sampling to estimate the abundance of Hawai‘i ʻĀkepas in portions of Hawai‘i Volcanoes National Park (HAVO) and the Kaʻū Forest Reserve (KFR) on Mauna Loa volcano. We then compiled the survey data from four other populations to provide a global population estimate. In our HAVO and KFR study area, we mapped habitat classes to determine the population densities in each habitat. Densities were highest (1.03 birds/ha) in open‐canopy montane ʻōhiʻa (Metrosideros polymorpha) woodland. In contrast, densities of the largest ʻĀkepa population on Mauna Kea volcano were highest in closed‐canopy ʻōhiʻa and koa (Acacia koa) forest where the species is dependent on nest cavities in tall (> 15 m), large (> 50‐cm diameter at breast height) trees. We surveyed potential nesting habitat in HAVO and KFR and found only one cavity in the short‐stature montane ʻōhiʻa woodland and five cavities in the tall‐stature forest. Differences in densities between the Mauna Kea and Mauna Loa populations suggest that Hawai‘i ʻĀkepas may exhibit different foraging and nesting behaviors in the two habitats. The estimated overall population density in the HAVO and KFR study area was 0.52 birds/ha, which equates to 3663 (95% CI 1725–6961) birds in their 11,377‐ha population range. We calculated a global population of 16,428 (95% CI 10,065–25,198) birds, which is similar to an estimate of 13,892 (95% CI 10,315–17,469) birds made in 1986. Our results suggest that populations are stable to increasing in the two largest populations, but the three other populations are smaller (range = 77–1443 birds) and trends

New insights into the magma chamber activity under Mauna Loa inferred from SBAS-InSAR and geodetic inversion modelling

Science.gov (United States)

Varugu, B. K.; Amelung, F.

2017-12-01

Mauna Loa volcano, located on the Big Island, Hawaii, is the largest volcano on the earth and historically been one of the most active volcanoes on the earth. Since its last eruption in 1984, there was a decrease in the magmatic activity, yet episodic inflations with increased seismicity sparks interests in the scientific community and there is strong need to monitor the volcano with growing infrastructure close to the flanks of the volcano. Geodetic modelling of the previous inflations illustrate that the magma activity is due to inflation of hydraulically connected dike and magma chamber located from 4-8km beneath the summit (Amelung et al. 2007). Most of the seismicity observed on Mauna Loa is due to the movement along a decollement fault situated at the base of the volcano. Magma inflation under Mauna Loa has started again during the last quarter of 2013 and is continuing still with an increased seismicity. In this study, we used 140 images form COSMO SkyMED between 2013-2017 to derive and model the ground deformation. We carried out time series InSAR analysis using Small Baseline (SB) approach. While the deformation pattern seems similar in many ways to the previous inflation periods, geodetic modelling for inversion of source parameters indicate a significant propagation of the dike ( 1 km) into the South West Rift Zone(SWRZ) and a decreased depth of the dike top from summit, compared to the previous inflations. Such propagation needs to be studied further in view of the steep slope of SWRZ. In understanding the dynamics of this propagating dike, we also observed an increased seismic activity since 2014 in the vicinity of the modelled dike. Here in this study we attempt to characterize the stresses induced by the propagating dike and seaward slipping movement along the basal decollement, to explain the increased seismicity using a finite element model.

Perspectives on basaltic magma crystallization and differentiation: Lava-lake blocks erupted at Mauna Loa volcano summit, Hawaii

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McCarter, Renee L.; Fodor, R.V.; Trusdell, Frank A.

2006-01-01

Explosive eruptions at Mauna Loa summit ejected coarse-grained blocks (free of lava coatings) from Moku'aweoweo caldera. Most are gabbronorites and gabbros that have 0–26 vol.% olivine and 1–29 vol.% oikocrystic orthopyroxene. Some blocks are ferrogabbros and diorites with micrographic matrices, and diorite veins (≤2 cm) cross-cut some gabbronorites and gabbros. One block is an open-textured dunite.The MgO of the gabbronorites and gabbros ranges ∼ 7–21 wt.%. Those with MgO >10 wt.% have some incompatible-element abundances (Zr, Y, REE; positive Eu anomalies) lower than those in Mauna Loa lavas of comparable MgO; gabbros (MgO <10 wt.%) generally overlap lava compositions. Olivines range Fo83–58, clinopyroxenes have Mg#s ∼83–62, and orthopyroxene Mg#s are 84–63 — all evolved beyond the mineral-Mg#s of Mauna Loa lavas. Plagioclase is An75–50. Ferrogabbro and diorite blocks have ∼ 3–5 wt.% MgO (TiO2 3.2–5.4%; K2O 0.8–1.3%; La 16–27 ppm), and a diorite vein is the most evolved (SiO2 59%, K2O 1.5%, La 38 ppm). They have clinopyroxene Mg#s 67–46, and plagioclase An57–40. The open-textured dunite has olivine ∼ Fo83.5. Seven isotope ratios are 87Sr/86Sr 0.70394–0.70374 and 143Nd/144Nd 0.51293–0.51286, and identify the suite as belonging to the Mauna Loa system.Gabbronorites and gabbros originated in solidification zones of Moku'aweoweo lava lakes where they acquired orthocumulate textures and incompatible-element depletions. These features suggest deeper and slower cooling lakes than the lava lake paradigm, Kilauea Iki, which is basalt and picrite. Clinopyroxene geobarometry suggests crystallization at <1 kbar P. Highly evolved mineral Mg#s, <75, are largely explained by cumulus phases exposed to evolving intercumulus liquids causing compositional ‘shifts.’ Ferrogabbro and diorite represent segregation veins from differentiated intercumulus liquids filter pressed into rigid zones of cooling lakes. Clinopyroxene

Chemical and Mineralogical Characterization of a Hematite-bearing Ridge on Mauna Kea, Hawaii: A Potential Mineralogical Process Analog for the Mount Sharp Hematite Ridge

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Graff, T. G.; Morris, R. V.; Ming, D. W.; Hamilton, J. C.; Adams, M.; Fraeman, A. A.; Arvidson, R. E.; Catalano, J. G.; Mertzman, S. A.

2014-01-01

The Mars Science Laboratory (MSL) rover Curiosity landed in Gale Crater in August 2012 and is currently roving towards the layered central mound known as Mount Sharp [1]. Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) hyperspectral data indicate Mount Sharp contains an 5 km stratigraphic sequence including Fe-Mg smectites, hematite, and hydrated sulfates in the lower layers separated by an unconformity from the overlying anhydrous strata [1,2,3]. Hematite was initially detected in CRISM data to occur in the lower sulfate layers on the north side of the mound [2]. [3] further mapped a distinct hematite detection occurring as part of a 200 m wide ridge that extends 6.5 km NE-SW, approximately parallel with the base of Mount Sharp. It is likely a target for in-situ analyses by Curiosity. We document here the occurrence of a stratum of hematite-bearing breccia that is exposed on the Puu Poliahu cinder cone near the summit of Mauna Kea volcano (Hawaii) (Fig.1). The stratum is more resistant to weathering than surrounding material, giving it the appearance of a ridge. The Mauna Kea hematite ridge is thus arguably a potential terrestrial mineralogical and process analog for the Gale Crater hematite ridge. We are acquiring a variety of chemical and mineralogical data on the Mauna Kea samples, with a focus on the chemical and mineralogical information already available or planned for the Gale hematite ridge.

Moessbauer/XRF MIMOS Instrumentation and Operation During the 2012 Analog Field Test on Mauna Kea Volcano, Hawaii

Science.gov (United States)

Graff, Trevor G.; Morris, R. V.; Klingelhofer, G.; Blumers, M.

2013-01-01

Field testing and scientific investigations were conducted on the Mauna Kea Volcano, Hawaii, as part of the 2012 Moon and Mars Analog Mission Activities (MMAMA). Measurements were conducted using both stand-alone and rover-mounted instruments to determine the geophysical and geochemical properties of the field site, as well as provide operational constraints and science considerations for future robotic and human missions [1]. Reported here are the results from the two MIMOS instruments deployed as part of this planetary analog field test.

Controls on carbon storage and weathering in volcanic ash soils across a climate gradient on Mauna Kea, Hawaii

Science.gov (United States)

Kramer, M. G.; Chadwick, O.

2017-12-01

Volcanic ash soils retain the largest and most persistent soil carbon pools of any ecosystem. However, the mechanisms governing soil carbon accumulation and weathering during initial phases of weathering are not well understood. We examined soil organic matter dynamics and weathering across a high altitude (3563 - 3013 m) 20 ky climate gradient on Mauna Kea in Hawaii. Four elevation sites were selected ( 250-500 mm rainfall) which range from arid-periglacial to sites which contain a mix of shrubs and grasses. At each site, between 2-3 pits were dug and major diagnostic horizons down to bedrock (in-tact lava) were sampled. Soils were analyzed for particle size, organic C and N, soil pH, exchangeable cations, base saturation, NaF pH, phosphorous sorption and bulk elements. Mass loss and pedogenic metal accumulation (hydroxlamine Fe, Al and Si extractions) were used to measure extent of weathering, leaching, changes in soil mineralogy and carbon accumulation with the short-range-ordered (SRO) minerals. Reactive-phase (SRO) minerals show a general trend of increasing abundance through the soil depth profile with increasing rainfall. However carbon accumulation patterns across the climate gradient are largely decoupled from these trends. The results suggest that after 20ky, pedogenic processes have altered the nature and composition of the volcanic ash such that it is capable of retaining soil C even where organic acid influences from plant material and leaching from rainfall is severely limited. Comparisons with lower elevation soils on Mauna Kea and other moist mesic (2500mm rainfall) sites on Hawaii suggest that these soils have reached only between 1-15 % of their capacity to retain carbon. Our results suggest that in low rainfall and a cold climate, after 20ky, weathering has advanced but is decoupled from soil carbon accumulation patterns and the associated influence of vegetation on soil development. Changes in soil carbon composition and amount across the entire

The ISRU Field Tests 2010 and 2012 at Mauna Kea, Hawaii: Results from the Miniaturised Mossbauer Spectrometers Mimos II and Mimos IIA

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Klingelhoefer, G.; Morris, R. V.; Blumers, M; Bernhardt, B.; Graff, T.

2014-01-01

The 2010 and 2012 In-Situ Resource Utilization Analogue Test (ISRU) [1] on the Mauna Kea volcano in Hawai'i was coordinated by the Northern Centre for Advanced Technology (NORCAT) in collaboration with the Canadian Space Agency (CSA), the German Aerospace Center (DLR), and the National Aeronautics and Space Administration (NASA), through the PISCES program. Several instruments were tested as reference candidates for future analogue testing at the new field test site at the Mauna Kea volcano in Hawai'i. The fine-grained, volcanic nature of the material is a suitable lunar and martian analogue, and can be used to test excavation, site preparation, and resource utilization techniques. The 2010 location Pu'u Hiwahine, a cinder cone located below the summit of Mauna Kea (19deg45'39.29" N, 155deg28'14.56" W) at an elevation of 2800 m, provides a large number of slopes, rock avalanches, etc. to perform mobility tests, site preparation or resource prospecting. Besides hardware testing of technologies and systems related to resource identification, also in situ science measurements played a significant role in integration of ISRU and science instruments. For the advanced Mössbauer instrument MIMOS IIA, the new detector technologies and electronic components increase sensitivity and performance significantly. In combination with the high energy resolution of the SDD it is possible to perform Xray fluorescence analysis simultaneously to Mössbauer spectroscopy. In addition to the Fe-mineralogy, information on the sample's elemental composition will be gathered. The 2010 and 2012 field campaigns demonstrated that in-situ Mössbauer spectroscopy is an effective tool for both science and feedstock exploration and process monitoring. Engineering tests showed that a compact nickel metal hydride battery provided sufficient power for over 12 hr of continuous operation for the MIMOS instruments.

Assessing individual and organizational response to volcanic crisis and unrest at Kīlauea and Mauna Loa volcanoes, Hawai'i

Science.gov (United States)

Reeves, Ashleigh; Gregg, Chris; Lindell, Michael; Prater, Carla; Joyner, Timothy; Eggert, Sarah

2017-04-01

This study describes response to and preparedness for eruption and unrest at Kīlauea and Mauna Loa volcanoes, respectively. The on-going 1983-present eruption of Kīlauea's East Rift Zone (ERZ) has generated a series of lava flow crises, the latest occurring in 2014 and 2015 when lava from a new vent flowed northeast and into the perimeter of developed areas in the lower Puna District, some 20km distant. It took ca. 2 months for the June 27 lava flow to advance a distance to which scientists reported it might be a concern to people downslope, but this prompted widespread formal and informal responses and culminated in improvements to infrastructure, voluntary evacuations of residents and businesses and closure of schools. Unlike Kīlauea, which has had frequent crises since the mid-20th century, the last eruption of nearby Mauna Loa occurred in 1984 and the last eruption and crisis on its Southwest Rift Zone (SWZ) was in 1950, so residents there are less familiar with eruptions than in Puna. In September 2015, the US Geological Survey, Hawaiian Volcano Observatory upgraded Mauna Loa's Alert Level from Normal to Advisory due to increases in unrest above known background levels. A crisis on Mauna Loa's SWZ would likely be much different than the recent 2014-15 crisis at Kīlauea as steep topography downslope of the SWZ and typical high discharge rates mean lava flows move fast, posing increased risk to areas downslope. Typically, volcanic eruptions have significant economic consequences out of proportion with their magnitudes. Furthermore, uncertainties regarding the physical and organizational communication of risk information amplify these economic losses. One significant impediment to risk communication is limited knowledge about the most effective ways to verbally, numerically and graphically communicate scientific uncertainty. This was a challenge in the recent lava flow crisis on Kīlauea. The public's demand for near-real time information updates, including

Home range and movements of Feral cats on Mauna Kea, Hawai'i

Science.gov (United States)

Goltz, Dan M.; Hess, S.C.; Brinck, K.W.; Banko, P.C.; Danner, R.M.

2008-01-01

Feral cats Felis catus in dry subalpine woodland of Mauna Kea, Hawai'i, live in low density and exhibit some of the largest reported home ranges in the literature. While 95% fixed kemel home range estimates for three females averaged 772 ha, four males averaged 1 418 ha, and one male maintained a home range of 2 050 ha. Mean daily movement rates between sexes overlapped widely and did not differ significantly (P = 0.083). Log-transformed 95% kernel home ranges for males were significantly larger than those of females (P = 0.024), but 25% kernel home ranges for females were larger than those of males (P = 0.017). Moreover, log-transformed home ranges of males were also significantly larger than those of females in this and seven other studies from the Pacific region (P = 0.044). Feral cats present a major threat to endangered Hawaiian birds, but knowledge of their ecology can be used for management by optimizing trap spacing and creating buffer zones around conservation areas.

Hematite Spherules in Basaltic Tephra Altered Under Aqueous, Acid-Sulfate Conditions on Mauna Kea Volcano, Hawaii: Possible Clues for the Occurrence of Hematite-Rich Spherules in the Burns Formation at Meridiani Planum, Mars

Science.gov (United States)

Morris, R. V.; Ming, D. W.; Graff, T. G.; Arvidson, R. E.; Bell, J. F., III; Squyres, S. W.; Mertzman, S. A.; Gruener, J. E.; Golden, D. C.; Robinson, G. A.

2005-01-01

Iron-rich spherules (>90% Fe2O3 from electron microprobe analyses) approx.10-100 microns in diameter are found within sulfate-rich rocks formed by aqueous, acid-sulfate alteration of basaltic tephra on Mauna Kea volcano, Hawaii. Although some spherules are nearly pure Fe, most have two concentric compositional zones, with the core having a higher Fe/Al ratio than the rim. Oxide totals less than 100% (93-99%) suggest structural H2O and/or /OH. The transmission Moessbauer spectrum of a spherule-rich separate is dominated by a hematite (alpha-Fe2O3) sextet whose peaks are skewed toward zero velocity. Skewing is consistent with Al(3+) for Fe(3+) substitution and structural H2O and/or /OH. The grey color of the spherules implies specular hematite. Whole-rock powder X-ray diffraction spectra are dominated by peaks from smectite and the hydroxy sulfate mineral natroalunite as alteration products and plagioclase feldspar that was present in the precursor basaltic tephra. Whether spherule formation proceeded directly from basaltic material in one event (dissolution of basaltic material and precipitation of hematite spherules) or whether spherule formation required more than one event (formation of Fe-bearing sulfate rock and subsequent hydrolysis to hematite) is not currently constrained. By analogy, a formation pathway for the hematite spherules in sulfate-rich outcrops at Meridiani Planum on Mars (the Burns formation) is aqueous alteration of basaltic precursor material under acid-sulfate conditions. Although hydrothermal conditions are present on Mauna Kea, such conditions may not be required for spherule formation on Mars if the time interval for hydrolysis at lower temperatures is sufficiently long.

Radiocarbon dates for lava flows from northeast rift zone of Mauna Loa Volcano, Hilo 7 1/2 minute quadrangle, Island of Hawaii

Science.gov (United States)

Buchanan-Banks, J. M.; Lockwood, J.P.; Rubin, M.

1989-01-01

Twenty-eight 14C analyses are reported for carbonized roots and other plant material collected from beneath 15 prehistoric lava flows erupted from the northeast rift zone (NERZ) of Mauna Loa Volcano (ML). The new 14C dates establish ages for 13 previously undated lava flows, and correct or add to information previously reported. Limiting ages on other flows that lie either above or below the dated flows are also established. These dates help to unravel the eruptive history of ML's NERZ. -from Authors

Combined U-Th/He and 40Ar/39Ar geochronology of post-shield lavas from the Mauna Kea and Kohala volcanoes, Hawaii

Energy Technology Data Exchange (ETDEWEB)

Aciego, S.M.; Jourdan, F.; DePaolo, D.J.; Kennedy, B.M.; Renne, P.R.; Sims, K.W.W.

2009-10-01

Late Quaternary, post-shield lavas from the Mauna Kea and Kohala volcanoes on the Big Island of Hawaii have been dated using the {sup 40}Ar/{sup 39}Ar and U-Th/He methods. The objective of the study is to compare the recently demonstrated U-Th/He age method, which uses basaltic olivine phenocrysts, with {sup 40}Ar/{sup 39}Ar ages measured on groundmass from the same samples. As a corollary, the age data also increase the precision of the chronology of volcanism on the Big Island. For the U-Th/He ages, U, Th and He concentrations and isotopes were measured to account for U-series disequilibrium and initial He. Single analyses U-Th/He ages for Hamakua lavas from Mauna Kea are 87 {+-} 40 ka to 119 {+-} 23 ka (2{sigma} uncertainties), which are in general equal to or younger than {sup 40}Ar/{sup 39}Ar ages. Basalt from the Polulu sequence on Kohala gives a U-Th/He age of 354 {+-} 54 ka and a {sup 40}Ar/{sup 39}Ar age of 450 {+-} 40 ka. All of the U-Th/He ages, and all but one spurious {sup 40}Ar/{sup 39}Ar ages conform to the previously proposed stratigraphy and published {sup 14}C and K-Ar ages. The ages also compare favorably to U-Th whole rock-olivine ages calculated from {sup 238}U - {sup 230}Th disequilibria. The U-Th/He and {sup 40}Ar/{sup 39}Ar results agree best where there is a relatively large amount of radiogenic {sup 40}Ar (>10%), and where the {sup 40}Ar/{sup 36}Ar intercept calculated from the Ar isochron diagram is close to the atmospheric value. In two cases, it is not clear why U-Th/He and {sup 40}Ar/{sup 39}Ar ages do not agree within uncertainty. U-Th/He and {sup 40}Ar/{sup 39}Ar results diverge the most on a low-K transitional tholeiitic basalt with abundant olivine. For the most alkalic basalts with negligible olivine phenocrysts, U-Th/He ages were unattainable while {sup 40}Ar/{sup 39}Ar results provide good precision even on ages as low as 19 {+-} 4 ka. Hence, the strengths and weaknesses of the U-Th/He and {sup 40}Ar/{sup 39}Ar methods are

Performance of Regolith Feed Systems for Analog Field Tests of In-Situ Resource Utilization Oxygen Production Plants in Mauna Kea, Hawaii

Science.gov (United States)

Townsend, Ivan I.; Mueller, Robert P.; Mantovani, James G.; Zacny, Kris A.; Craft, Jack

2010-01-01

This paper focuses on practical aspects of mechanical auger and pneumatic regolith conveying system feeding In-Situ Resource Utilization Oxygen production plants. The subsystems of these feedstock delivery systems include an enclosed auger device, pneumatic venturi educator, jet-lift regolith transfer, innovative electro-cyclone gas-particle separation/filtration systems, and compressors capable of dealing with hot hydrogen and/or methane gas re-circulating in the system. Lessons learned from terrestrial laboratory, reduced gravity and field testing on Mauna Kea Volcano in Hawaii during NASA lunar analog field tests will be discussed and practical design tips will be presented.

Evidence of feline immunodeficiency virus, feline leukemia virus, and Toxoplasma gondii in feral cats on Mauna Kea, Hawaii.

Science.gov (United States)

Danner, Raymond M; Goltz, Daniel M; Hess, Steven C; Banko, Paul C

2007-04-01

We determined prevalence to feline immunodeficiency virus (FIV) antibodies, feline leukemia virus (FeLV) antigen, and Toxoplasma gondii antibodies in feral cats (Felis catus) on Mauna Kea Hawaii from April 2002 to May 2004. Six of 68 (8.8%) and 11 of 68 (16.2%) cats were antibody positive to FIV and antigen positive for FeLV, respectively; 25 of 67 (37.3%) cats were seropositive to T. gondii. Antibodies to FeLV and T. gondii occurred in all age and sex classes, but FIV occurred only in adult males. Evidence of current or previous infections with two of these infectious agents was detected in eight of 64 cats (12.5%). Despite exposure to these infectious agents, feral cats remain abundant throughout the Hawaiian Islands.

Hawaiian fissure fountains: Quantifying vent and shallow conduit geometry, episode 1 of the 1969-1974 Mauna Ulu eruption: Chapter 17

Science.gov (United States)

Parcheta, Carolyn; Fagents, Sarah; Swanson, Donald A.; Houghton, Bruce F.; Ericksen, Todd; Carey, Rebecca; Cayol, Valérie; Poland, Michael P.; Weis, Dominique

2015-01-01

Geometries of shallow magmatic pathways feeding volcanic eruptions are poorly constrained, yet many key interpretations about eruption dynamics depend on knowledge of these geometries. Direct quantification is difficult because vents typically become blocked with lava at the end of eruptions. Indirect geophysical techniques have shed light on some volcanic conduit geometries, but the scales are too coarse to resolve narrow fissures (widths typically 1 m). Kīlauea's Mauna Ulu eruption, which started with 30 m. Direct measurements at the ground surface were augmented by tripod-mounted lidar measurements to quantify the shallow conduit geometry for three vents at a resolution eruptive behavior, especially if incorporated into computer models.

Field Testing of a Pneumatic Regolith Feed System During a 2010 ISRU Field Campaign on Mauna Kea, Hawaii

Science.gov (United States)

Craft, Jack; Zacny, Kris; Chu, Philip; Wilson, Jack; Santoro, Chris; Carlson, Lee; Maksymuk, Michael; Townsend, Ivan I.; Mueller, Robert P.; Mantovani, James G.

2010-01-01

Lunar In Situ Resource Utilization (ISRU) consists of a number of tasks starting with mining of lunar regolith, followed by the transfer of regolith to an oxygen extraction reactor and finally processing the regolith and storing of extracted oxygen. The transfer of regolith from the regolith hopper at the ground level to an oxygen extraction reactor many feet above the surface could be accomplished in different ways, including using a mechanical auger, bucket ladder system or a pneumatic system. The latter system is commonly used on earth when moving granular materials since it offers high reliability and simplicity of operation. In this paper, we describe a pneumatic regolith feed system, delivering feedstock to a Carbothermal reactor and lessons learned from deploying the system during the 2010 ISRU field campaign on the Mauna Kea, Hawaii.

Evidence of feline immunodeficiency virus, feline leukemia virus, and Toxoplasma gondii in feral cats on Mauna Kea, Hawaii

Science.gov (United States)

Danner, R.M.; Goltz, Dan M.; Hess, S.C.; Banko, P.C.

2007-01-01

We determined prevalence to feline immunodeficiency virus (FIV) antibodies, feline leukemia virus (FeLV) antigen, and Toxoplasma gondii antibodies in feral cats (Felis catus) on Mauna Kea Hawaii from April 2002 to May 2004. Six of 68 (8.8%) and 11 of 68 (16.2%) cats were antibody positive to FIV and antigen positive for FeLV, respectively; 25 of 67 (37.3%) cats were seropositive to T. gondii. Antibodies to FeLV and T. gondii occurred in all age and sex classes, but FIV occurred only in adult males. Evidence of current or previous infections with two of these infectious agents was detected in eight of 64 cats (12.5%). Despite exposure to these infectious agents, feral cats remain abundant throughout the Hawaiian Islands. ?? Wildlife Disease Association 2007.

Statistical analysis of the mesospheric inversion layers over two symmetrical tropical sites: Réunion (20.8° S, 55.5° E) and Mauna Loa (19.5° N, 155.6° W)

Science.gov (United States)

Bègue, Nelson; Mbatha, Nkanyiso; Bencherif, Hassan; Tato Loua, René; Sivakumar, Venkataraman; Leblanc, Thierry

2017-11-01

In this investigation a statistical analysis of the characteristics of mesospheric inversion layers (MILs) over tropical regions is presented. This study involves the analysis of 16 years of lidar observations recorded at Réunion (20.8° S, 55.5° E) and 21 years of lidar observations recorded at Mauna Loa (19.5° N, 155.6° W) together with SABER observations at these two locations. MILs appear in 10 and 9.3 % of the observed temperature profiles recorded by Rayleigh lidar at Réunion and Mauna Loa, respectively. The parameters defining MILs show a semi-annual cycle over the two selected sites with maxima occurring near the equinoxes and minima occurring during the solstices. Over both sites, the maximum mean amplitude is observed in April and October, and this corresponds to a value greater than 35 K. According to lidar observations, the maximum and minimum mean of the base height ranged from 79 to 80.5 km and from 76 to 77.5 km, respectively. The MILs at Réunion appear on average ˜ 1 km thinner and ˜ 1 km lower, with an amplitude of ˜ 2 K higher than Mauna Loa. Generally, the statistical results for these two tropical locations as presented in this investigation are in fairly good agreement with previous studies. When compared to lidar measurements, on average SABER observations show MILs with greater amplitude, thickness and base altitudes of 4 K, 0.75 and 1.1 km, respectively. Taking into account the temperature error by SABER in the mesosphere, it can therefore be concluded that the measurements obtained from lidar and SABER observations are in significant agreement. The frequency spectrum analysis based on the lidar profiles and the 60-day averaged profile from SABER confirms the presence of the semi-annual oscillation where the magnitude maximum is found to coincide with the height range of the temperature inversion zone. This connection between increases in the semi-annual component close to the inversion zone is in agreement with most previously

Redox variations in Mauna Kea lavas, the oxygen fugacity of the Hawaiian plume, and the role of volcanic gases in Earth's oxygenation.

Science.gov (United States)

Brounce, Maryjo; Stolper, Edward; Eiler, John

2017-08-22

The behavior of C, H, and S in the solid Earth depends on their oxidation states, which are related to oxygen fugacity ( f O 2 ). Volcanic degassing is a source of these elements to Earth's surface; therefore, variations in mantle f O 2 may influence the f O 2 at Earth's surface. However, degassing can impact magmatic f O 2 before or during eruption, potentially obscuring relationships between the f O 2 of the solid Earth and of emitted gases and their impact on surface f O 2 We show that low-pressure degassing resulted in reduction of the f O 2 of Mauna Kea magmas by more than an order of magnitude. The least degassed magmas from Mauna Kea are more oxidized than midocean ridge basalt (MORB) magmas, suggesting that the upper mantle sources of Hawaiian magmas have higher f O 2 than MORB sources. One explanation for this difference is recycling of material from the oxidized surface to the deep mantle, which is then returned to the surface as a component of buoyant plumes. It has been proposed that a decreasing pressure of volcanic eruptions led to the oxygenation of the atmosphere. Extension of our findings via modeling of degassing trends suggests that a decrease in eruption pressure would not produce this effect. If degassing of basalts were responsible for the rise in oxygen, it requires that Archean magmas had at least two orders of magnitude lower f O 2 than modern magmas. Estimates of f O 2 of Archean magmas are not this low, arguing for alternative explanations for the oxygenation of the atmosphere.

The Perception of Volcanic Risk in Kona Communities from Mauna Loa and Hualalai Volcanoes, Hawai`i

Science.gov (United States)

Gregg, C. E.; Houghton, B. F.; Johnston, D. M.; Paton, D.; Swanson, D. A.

2002-12-01

Hawai`i's coastal communities are becoming increasingly vulnerable to natural hazards as a consequence of increasing population and infrastructure. Volcanic hazards in Kona (i.e., western side of the island) stem primarily from Mauna Loa and Hualalai volcanoes. The former has erupted thirty-nine times since 1832. Lava flows were emplaced in Kona during six of these, but last impacted Kona in 1950. Hualalai last erupted in c. 1800. The most recent eruptions at each volcano were damaging to society, but future eruptions would exact much greater impacts. The second largest city on the island, several resort complexes, and an international airport are located within 15 km of vents. Society's proximity to potential eruptive sources, a potential for relatively fast moving lavas, and the relatively long time intervals since the last eruptions in Kona, are the stimuli for this study of risk perception. Target populations were high school students and their parents, and the greater adult public (n=462). Using this data, we discuss threat knowledge as an influence on risk perception and perceptions as a driving mechanism for preparedness. Threat knowledge and perception of risk were found to be low to moderate. On average less than two-thirds of residents were aware of the most recent eruptions that impacted Kona and a minority felt that Mauna Loa and Hualalai could erupt again. Furthermore, only about one-third were aware that lava flows could reach the coast in Kona in under three hours. Lava flows and ash fall were perceived to be among the least likely hazards to affect the respondent's community. Not unexpectedly, individual preparedness measures were found to be limited to simple tasks, while measures specific to infrequent hazard events such as volcanic eruptions and earthquakes were seldom adopted. Respondents exhibit an "unrealistic optimism bias" and infer that responsibility for community preparedness for future eruptions rests primarily with officials. Hazard

Redox variations in Mauna Kea lavas, the oxygen fugacity of the Hawaiian plume, and the role of volcanic gases in Earth’s oxygenation

Energy Technology Data Exchange (ETDEWEB)

Brounce, Maryjo; Stolper, Edward; Eiler, John

2017-08-07

The behavior of C, H, and S in the solid Earth depends on their oxidation states, which are related to oxygen fugacity (fO2). Volcanic degassing is a source of these elements to Earth’s surface; therefore, variations in mantle fO2 may influence the fO2 at Earth’s surface. However, degassing can impact magmatic fO2 before or during eruption, potentially obscuring relationships between the fO2 of the solid Earth and of emitted gases and their impact on surface fO2. We show that low-pressure degassing resulted in reduction of the fO2 of Mauna Kea magmas by more than an order of magnitude. The least degassed magmas from Mauna Kea are more oxidized than midocean ridge basalt (MORB) magmas, suggesting that the upper mantle sources of Hawaiian magmas have higher fO2 than MORB sources. One explanation for this difference is recycling of material from the oxidized surface to the deep mantle, which is then returned to the surface as a component of buoyant plumes. It has been proposed that a decreasing pressure of volcanic eruptions led to the oxygenation of the atmosphere. Extension of our findings via modeling of degassing trends suggests that a decrease in eruption pressure would not produce this effect. If degassing of basalts were responsible for the rise in oxygen, it requires that Archean magmas had at least two orders of magnitude lower fO2 than modern magmas. Estimates of fO2 of Archean magmas are not this low, arguing for alternative explanations for the oxygenation of the atmosphere.

Chemical and Mineralogical Characterization of Acid-Sulfate Alteration of Basaltic Material on Mauna Kea Volcano, Hawaii: Jarosite and Hydrated Halloysite

Science.gov (United States)

Graff, Trevor G.; Morris, R. V.; Archilles C. N.; Agresti, D. G.; Ming, D. W.; Hamilton, J. C.; Mertzman, S. A.; Smith, J.

2012-01-01

Sulfates have been identified on the martian surface during robotic surface exploration and by orbital remote sensing. Measurements at Meridiani Planum (MP) by the Alpha-Particle X-ray Spectrometer (APXS) and Mossbauer (MB) instruments on the Mars Exploration Rover Opportunity document the presence of a ubiquitous sulfate-rich outcrop (20-40% SO3) that has jarosite as an anhydrous Fe3+-sulfate [1- 3]. The presence of jarosite implies a highly acidic (pH <3) formation environment [4]. Jarosite and other sulfate minerals, including kieserite, gypsum, and alunite have also been identified in several locations in orbital remote sensing data from the MEx OMEGA and MRO CRISM instruments [e.g. 5-8]. Acid sulfate weathering of basaltic materials is an obvious pathway for formation of sulfate-bearing phases on Mars [e.g. 4, 9, 10]. In order to constrain acid-sulfate pathways on Mars, we are studying the mineralogical and chemical manifestations of acid-sulfate alteration of basaltic compositions in terrestrial environments. We have previously shown that acidsulfate alteration of tephra under hydrothermal conditions on the Puu Poliahu cone (summit region of Mauna Kea volcano, Hawaii) resulted in jarosite and alunite as sulfate-bearing alteration products [11-14]. Other, more soluble, sulfates may have formed, but were leached away by rain and melting snow. Acidsulfate processes on Puu Poliahu also formed hematite spherules similar (except in size) to the hematite spherules observed at MP as an alteration product [14]. Phyllosilicates, usually smectite }minor kaolinite are also present as alteration products [13]. We discuss here an occurrence of acid-sulfate alteration on Mauna Kea Volcano (Hawaii). We report VNIR spectra (0.35-2.5 microns ASD spectrometer), Mossbauer spectra (MER-like ESPI backscatter spectrometer), powder XRD (PANalytical), and major element chemical compositions (XRF with LOI and Fe redox) for comparison to similar data acquired or to be acquired by MRO

Contrasting patterns of vesiculation in low, intermediate, and high Hawaiian fountains: A case study of the 1969 Mauna Ulu eruption

Science.gov (United States)

Parcheta, Carolyn E.; Houghton, Bruce F.; Swanson, Donald A.

2013-01-01

Hawaiian-style eruptions, or Hawaiian fountains, typically occur at basaltic volcanoes and are sustained, weakly explosive jets of gas and dominantly coarse, juvenile ejecta (dense spatter to delicate reticulite). Almost the entire range of styles and mass eruption rates within Hawaiian fountaining occurred during twelve fountaining episodes recorded at Mauna Ulu, Kīlauea between May and December 1969. Such diversity in intensity and style is controlled during magma ascent by many processes that can be constrained by the size and shape of vesicles in the 1969 pyroclasts. This paper describes pyroclast vesicularity from high, intermediate, and low fountaining episodes with eruption rates from 0.05 to 1.3 × 106 m3 h− 1. As each eruptive episode progressed, magma ascent slowed in and around the vent system, offering extended time for bubbles to grow and coalesce. Late ejected pyroclasts are thus characterized by populations of fewer and larger vesicles with relaxed shapes. This progression continued in the intervals between episodes after termination of fountain activity. The time scale for this process of shallow growth, coalescence and relaxation of bubbles is typically tens of hours. Rims and cores of pumiceous pyroclasts from moderate to high fountaining episodes record a second post-fragmentation form of vesicle maturation. Partially thermally insulated pyroclasts can have internal bubble populations evolve more dynamically with continued growth and coalescence, on a time scale of only minutes, during transport in the fountains. Reticulite, which formed in a short-lived fountain 540 m in height, underwent late, short-lived bubble nucleation followed by rapid growth of a uniform bubble population in a thermally insulated fountain, and quenched at the onset of permeability before significant coalescence. These contrasting patterns of shallow degassing and outgassing were the dominant controls in determining both the form and duration of fountaining

Inflation Features of the Distal Pahoehoe Portion of the 1859 Mauna Loa Flow, Hawaii; Implications for Evaluating Planetary Lava Flows

Science.gov (United States)

Zimbelman, J. R.; Garry, W. B.; Bleacher, Jacob E.; Crumpler, L S.

2011-01-01

The 1859 eruption of Mauna Loa, Hawaii, resulted in the longest subaerial lava flow on the Big Island. Detailed descriptions were made of the eruption both from ships and following hikes by groups of observers; the first three weeks of the eruption produced an `a`a flow that reached the ocean, and the following 10 months produced a pahoehoe flow that also eventually reached the ocean. The distal portion of the 1859 pahoehoe flow component includes many distinctive features indicative of flow inflation. Field work was conducted on the distal 1859 pahoehoe flow during 2/09 and 3/10, which allowed us to document several inflation features, in or-der evaluate how well inflated landforms might be detected in remote sensing data of lava flows on other planets.

Statistical analysis of the mesospheric inversion layers over two symmetrical tropical sites: Réunion (20.8° S, 55.5° E and Mauna Loa (19.5° N, 155.6° W

Directory of Open Access Journals (Sweden)

N. Bègue

2017-11-01

Full Text Available In this investigation a statistical analysis of the characteristics of mesospheric inversion layers (MILs over tropical regions is presented. This study involves the analysis of 16 years of lidar observations recorded at Réunion (20.8° S, 55.5° E and 21 years of lidar observations recorded at Mauna Loa (19.5° N, 155.6° W together with SABER observations at these two locations. MILs appear in 10 and 9.3 % of the observed temperature profiles recorded by Rayleigh lidar at Réunion and Mauna Loa, respectively. The parameters defining MILs show a semi-annual cycle over the two selected sites with maxima occurring near the equinoxes and minima occurring during the solstices. Over both sites, the maximum mean amplitude is observed in April and October, and this corresponds to a value greater than 35 K. According to lidar observations, the maximum and minimum mean of the base height ranged from 79 to 80.5 km and from 76 to 77.5 km, respectively. The MILs at Réunion appear on average ∼ 1 km thinner and ∼ 1 km lower, with an amplitude of ∼ 2 K higher than Mauna Loa. Generally, the statistical results for these two tropical locations as presented in this investigation are in fairly good agreement with previous studies. When compared to lidar measurements, on average SABER observations show MILs with greater amplitude, thickness and base altitudes of 4 K, 0.75 and 1.1 km, respectively. Taking into account the temperature error by SABER in the mesosphere, it can therefore be concluded that the measurements obtained from lidar and SABER observations are in significant agreement. The frequency spectrum analysis based on the lidar profiles and the 60-day averaged profile from SABER confirms the presence of the semi-annual oscillation where the magnitude maximum is found to coincide with the height range of the temperature inversion zone. This connection between increases in the semi-annual component close to the

Changes in Mauna Kea Dry Forest Structure 2000-2014

Science.gov (United States)

Banko, Paul C.; Brinck, Kevin W.

2014-01-01

Changes in the structure of the subalpine vegetation of Palila Critical Habitat on the southwestern slope of Mauna Kea Volcano, Hawai‘i, were analyzed using 12 metrics of change in māmane (Sophora chrysophylla) and naio (Myoporum sandwicense) trees surveyed on plots in 2000 and 2014. These two dominant species were analyzed separately, and changes in their structure indicated changes in the forest’s health. There was a significant increase in māmane minimum crown height (indicating a higher ungulate “browse line”), canopy area, canopy volume, percentage of trees with ungulate damage, and percentage of dead trees. No significant changes were observed in māmane maximum crown height, proportion of plots with trees, sapling density, proportion of plots with saplings, or the height distribution of trees. The only significant positive change was for māmane tree density. Significantly negative changes were observed for naio minimum crown height, tree height, canopy area, canopy volume, and percentage of dead trees. No significant changes were observed in naio tree density, proportion of plots with trees, proportion of plots with saplings, or percentage of trees with ungulate damage. Significantly positive changes were observed in naio sapling density and the height distribution of trees. There was also a significant increase in the proportion of māmane vs. naio trees in the survey area. The survey methods did not allow us to distinguish among potential factors driving these changes for metrics other than the percentage of trees with ungulate damage. Continued ungulate browsing and prolonged drought are likely the factors contributing most to the observed changes in vegetation, but tree disease or insect infestation of māmane, or naio, and competition from alien grasses and other weeds could also be causing or exacerbating the impacts to the forest. Although māmane tree density has increased since 2000, this study also demonstrates that efforts by managers

COR1 Engineering Test Unit Measurements at the Mauna Loa Solar Observatory, September 2003

Science.gov (United States)

Thompson, William; Reginald, Nelson; Streander, Kim

2003-01-01

The COR1 Engineering Test Unit (ETU), which had been previously tested at the NCAR/HAO and NRL test facilities, was modified into an instrument capable of observing the Sun. It was then taken to the Mauna Loa Solar Observatory to observe the corona. The changes made to observe the Sun were as follows: 1. The plate scale was changed to accommodate the smaller Apogee camera. This change had already been made for the NRL tests. 2. The previous Oriel polarizer was replaced with a commercial Polarcor polarizer from Newport to be more flight-like. However, because of cost and availability considerations, this polarizer was smaller than those which will be used for flight. 3. A structure was placed around the back section of the instrument, to protect it from stray light. 4. A pointing spar borrowed from HAO was used to track the Sun. A few days into the test, it became evident that some artifacts were appearing in the data, and these artifacts were changing as the polarizer was rotated. It was decided to test two other polarizers, the Oriel polarizer which had been used in the previous tests at HAO and NRL, and a Nikon polarizer which was borrowed from a camera belonging to one of the observatory staff members. These three polarizers had much different qualities are shown.

Radon-222 in boundary layer and free tropospheric continental outflow events at three ACE-Asia sites

International Nuclear Information System (INIS)

Zahorowski, Wlodek; Chambers, Scott; Wang Tao

2005-01-01

A 1-year record of hourly atmospheric radon-222 concentration observations at three ACE-Asia network sites Hok Tsui (Hong Kong), Gosan (Jeju Island) and Mauna Loa Observatory (Hawaii) is presented and discussed. The observations include the spring 2001 ACE-Asia intensive operation period. Site locations were chosen for the experimental characterization of both boundary layer (Hok Tsui, Gosan) and free tropospheric (Mauna Loa) continental outflow to the Pacific. A significant seasonal variability in background radon concentration is quantified at each site with the ratios of winter maximum to summer minimum background of 96, 15 and 3 for Hok Tsui, Gosan and Mauna Loa, respectively. Only during summer were background radon concentrations directly comparable with unperturbed marine values (20 mBq/m 3 ). The variability in radon signal was characterized at each site on diurnal to seasonal timescales. The seasonal variability in fetch regions for air masses experiencing the greatest and smallest terrestrial influence was characterized using 10-day back trajectories of air masses corresponding to radon concentrations higher (lower) than the 90th (10th) percentile value. The trajectory analyses for Hok Tsui and Gosan, as well as a direct analysis of the experimental results, further supports the previously postulated existence of a strong spatial heterogeneity in the radon source strength in East Asia. Back trajectories of free tropospheric air masses reaching Mauna Loa indicated source regions deep within the Asian continent primarily between 20 and 40 deg N. This fetch region is different from that influencing the Hok Tsui and Gosan sites. The radon concentration of air masses reaching Mauna Loa was shown to vary seasonally as well as with latitude of the predominant fetch region. Possible mechanisms of this phenomenon have been identified and include (a) seasonal variation in the radon source, (b) seasonal variation in the strength, frequency and/or efficiency of

Radon-222 in boundary layer and free tropospheric continental outflow events at three ACE-Asia sites

OpenAIRE

Zahorowski, Wlodek; Chambers, Scott; Wang, Tao; Kang, Chang-Hee; Uno, Itsushi; Poon, Steven; Oh, Sung-Nam; Werczynski, Sylvester; Kim, Jiyoung; Henderson-Sellers, Ann

2011-01-01

A 1-year record of hourly atmospheric radon-222 concentration observations at three ACE-Asia network sites—Hok Tsui (Hong Kong), Gosan (Jeju Island) and Mauna Loa Observatory (Hawaii)—is presented and discussed. The observations include the spring 2001 ACE-Asia intensive operation period. Site locations were chosen for the experimental characterization of both boundary layer (Hok Tsui, Gosan) and free tropospheric (Mauna Loa) continental outflow to the Pacific. A significant seasonal variabil...

The perception of volcanic risk in Kona communities from Mauna Loa and Hualālai volcanoes, Hawai'i

Science.gov (United States)

Gregg, Chris E.; Houghton, Bruce F.; Johnston, David M.; Paton, Douglas; Swanson, D.A.

2004-01-01

Volcanic hazards in Kona (i.e. the western side of the island of Hawai'i) stem primarily from Mauna Loa and Huala??lai volcanoes. The former has erupted 39 times since 1832. Lava flows were emplaced in Kona during seven of these eruptions and last impacted Kona in 1950. Huala??lai last erupted in ca. 1800. Society's proximity to potential eruptive sources and the potential for relatively fast-moving lava flows, coupled with relatively long time intervals since the last eruptions in Kona, are the underlying stimuli for this study of risk perception. Target populations were high-school students and adults ( n =462). Using these data, we discuss threat knowledge as an influence on risk perception, and perception as a driving mechanism for preparedness. Threat knowledge and perception of risk were found to be low to moderate. On average, fewer than two-thirds of the residents were aware of the most recent eruptions that impacted Kona, and a minority felt that Mauna Loa and Huala??lai could ever erupt again. Furthermore, only about one-third were aware that lava flows could reach the coast in Kona in less than 3 h. Lava flows and ash fall were perceived to be among the least likely hazards to affect the respondent's community within the next 10 years, whereas vog (volcanic smog) was ranked the most likely. Less than 18% identified volcanic hazards as amongst the most likely hazards to affect them at home, school, or work. Not surprisingly, individual preparedness measures were found on average to be limited to simple tasks of value in frequently occurring domestic emergencies, whereas measures specific to infrequent hazard events such as volcanic eruptions were seldom adopted. Furthermore, our data show that respondents exhibit an 'unrealistic optimism bias' and infer that responsibility for community preparedness for future eruptions primarily rests with officials. We infer that these respondents may be less likely to attend to hazard information, react to warnings as

Automatic near-real-time detection of CMEs in Mauna Loa K-Cor coronagraph images

Science.gov (United States)

Thompson, W. T.; St Cyr, O. C.; Burkepile, J.; Posner, A.

2017-12-01

A simple algorithm has been developed to detect the onset of coronal massejections (CMEs), together with an estimate of their speed, in near-real-timeusing images of the linearly polarized white-light solar corona taken by theK-Cor telescope at the Mauna Loa Solar Observatory (MLSO). The algorithm usedis a variation on the Solar Eruptive Event Detection System (SEEDS) developedat George Mason University. The algorithm was tested against K-Cor data takenbetween 29 April 2014 and 20 February 2017, on days which the MLSO websitemarked as containing CMEs. This resulted in testing of 139 days worth of datacontaining 171 CMEs. The detection rate varied from close to 80% in 2014-2015when solar activity was high, down to as low as 20-30% in 2017 when activitywas low. The difference in effectiveness with solar cycle is attributed to thedifference in relative prevalance of strong CMEs between active and quietperiods. There were also twelve false detections during this time period,leading to an average false detection rate of 8.6% on any given day. However,half of the false detections were clustered into two short periods of a fewdays each when special conditions prevailed to increase the false detectionrate. The K-Cor data were also compared with major Solar Energetic Particle(SEP) storms during this time period. There were three SEP events detectedeither at Earth or at one of the two STEREO spacecraft where K-Cor wasobserving during the relevant time period. The K-Cor CME detection algorithmsuccessfully generated alerts for two of these events, with lead times of 1-3hours before the SEP onset at 1 AU. The third event was not detected by theautomatic algorithm because of the unusually broad width of the CME in positionangle.

Geomorphometric variability of "monogenetic" volcanic cones: Evidence from Mauna Kea, Lanzarote and experimental cones

Science.gov (United States)

Kervyn, M.; Ernst, G. G. J.; Carracedo, J.-C.; Jacobs, P.

2012-01-01

Volcanic cones are the most common volcanic constructs on Earth. Their shape can be quantified using two morphometric ratios: the crater/cone base ratio (W cr/W co) and the cone height/width ratio (H co/W co). The average values for these ratios obtained over entire cone fields have been explained by the repose angle of loose granular material (i.e. scoria) controlling cone slopes. The observed variability in these ratios between individual cones has been attributed to the effect of erosional processes or contrasting eruptive conditions on cone morphometry. Using a GIS-based approach, high spatial resolution Digital Elevation Models and airphotos, two new geomorphometry datasets for cone fields at Mauna Kea (Hawaii, USA) and Lanzarote (Canary Islands, Spain) are extracted and analyzed here. The key observation in these datasets is the great variability in morphometric ratios, even for simple-shape and well-preserved cones. Simple analog experiments are presented to analyze factors influencing the morphometric ratios. The formation of a crater is simulated within an analog cone (i.e. a sand pile) by opening a drainage conduit at the cone base. Results from experiments show that variability in the morphometric ratios can be attributed to variations in the width, height and horizontal offset of the drainage point relative to the cone symmetry axis, to the dip of the underlying slope or to the influence of a small proportion of fine cohesive material. GIS analysis and analog experiments, together with specific examples of cones documented in the field, suggest that the morphometric ratios for well-preserved volcanic cones are controlled by a combination of 1) the intrinsic cone material properties, 2) time-dependent eruption conditions, 3) the local setting, and 4) the method used to estimate the cone height. Implications for interpreting cone morphometry solely as either an age or as an eruption condition indicator are highlighted.

Quality assurance of the UV irradiances of the UV-B Monitoring and Research Program: the Mauna Loa test case

Science.gov (United States)

Zempila, Melina Maria; Davis, John; Janson, George; Olson, Becky; Chen, Maosi; Durham, Bill; Simpson, Scott; Straube, Jonathan; Sun, Zhibin; Gao, Wei

2017-09-01

The USDA UV-B Monitoring and Research Program (UVMRP) is an ongoing effort aiming to establish a valuable, longstanding database of ground-based ultraviolet (UV) solar radiation measurements over the US. Furthermore, the program aims to achieve a better understanding of UV variations through time, and develop a UV climatology for the Northern American section. By providing high quality radiometric measurements of UV solar radiation, UVMRP is also focusing on advancing science for agricultural, forest, and range systems in order to mitigate climate impacts. Within these foci, the goal of the present study is to investigate, analyze, and validate the accuracy of the measurements of the UV multi-filter rotating shadowband radiometer (UV-MFRSR) and Yankee (YES) UVB-1 sensor at the high altitude, pristine site at Mauna Loa, Hawaii. The response-weighted irradiances at 7 UV channels of the UV-MFRSR along with the erythemal dose rates from the UVB-1 radiometer are discussed, and evaluated for the period 2006-2015. Uncertainties during the calibration procedures are also analyzed, while collocated groundbased measurements from a Brewer spectrophotometer along with model simulations are used as a baseline for the validation of the data. Besides this quantitative research, the limitations and merits of the existing UVMRP methods are considered and further improvements are introduced.

Habitat and food preferences of the endangered Palila (Loxioides bailleui) on Mauna Kea, Hawai'i

Science.gov (United States)

Hess, Steven C.; Banko, Paul C.; Miller, Linda J.; Laniawe, Leona P.

2014-01-01

Seeds and flowers of the leguminous māmane (Sophora chrysophylla) tree are the primary food resource of the federally endangered Palila (Loxioides bailleui; Fringillidae: Drepanidinae), which is now restricted to dry subalpine woodland on Mauna Kea Volcano on the island of Hawai'i because of centuries of habitat degradation by non-native ungulates. Palila are morphologically and behaviorally adapted to consume māmane seeds by grasping seed pods with their feet and opening pods with stout bills and demonstrate limited ability to exploit alternative food resources. This degree of single species dependency is rare among birds and illustrates unique adaptations that also occurred in other Hawaiian species that are now extinct. In mixed-woodland with co-dominant naio (Myoporum sandwicense), Palila spent 1.7-3.9 times longer in māmane than in naio during foraging observations where naio was 1.3-4.6 times as dense as māmane. Naio fruit was readily available, but it comprised proportionally food items taken by Palila. Although māmane flowers were more abundant than māmane pods throughout this study except at one lower-elevation mixed-woodland site, Palila spent more time foraging on pods than flowers in both māmane woodland and mixed-woodland, but consumed more flowers than pods in mixed-woodland. Insects, which have been reported as an important component of the diet of Palila, were apparently taken rarely in this study. Protecting and restoring māmane in woodlands adjacent to the current range of Palila will benefit their recovery, allowing them to exploit increased food availability in areas of their former range.

Prevalence of pox-like lesions and malaria in forest bird communitites on leeward Mauna Loa volcano, Hawaii

Science.gov (United States)

Atkinson, C.T.; Lease, J.K.; Dusek, Robert J.; Samuel, M.D.

2005-01-01

Introduced avian pox virus and malaria have had devastating impacts on native Hawaiian forest birds, yet little has been published about their prevalence and distribution in forest bird communities outside of windward Hawaii Island. We surveyed native and non-native forest birds for these two diseases at three different elevations on leeward Mauna Loa Volcano at the Kona Forest Unit of Hakalau Forest National Wildlife Refuge. Prevalence of malaria by both serology and microscopy varied by elevation and ranged from 28% at 710 m to 13% at 1830 m. Prevalence of pox-like lesions also varied by altitude, ranging in native species from 10% at 710 m to 2% at 1830 m. Native species at all elevations had the highest prevalence of malarial antibody and pox-like lesions. By contrast, pox-like lesions were not detected in individuals of four non-native species and only 5% of Japanese White-eye (Zosterops japonicus) was positive for malaria. A significantly high proportion of birds with pox-like lesions also had serological evidence of concurrent, chronic malarial infections, suggesting an interaction between these diseases, dual transmission of both diseases by the primary mosquito vector (Culex quinquefasciatus) or complete recovery of some pox-infected birds without loss of toes. Results from this study document high prevalence of malaria and pox at this refuge. Development of effective disease control strategies will be important for restoration of remnant populations of the endangered 'Akiapola'au (Hemignathus munroi), Hawaii Creeper (Oreomystis mana), and Hawaii 'Akepa (Loxops coccineus coccineus) that still occur on the refuge.

Feasibility Study of Earthquake Early Warning in Hawai`i For the Mauna Kea Thirty Meter Telescope

Science.gov (United States)

Okubo, P.; Hotovec-Ellis, A. J.; Thelen, W. A.; Bodin, P.; Vidale, J. E.

2014-12-01

Earthquakes, including large damaging events, are as central to the geologic evolution of the Island of Hawai`i as its more famous volcanic eruptions and lava flows. Increasing and expanding development of facilities and infrastructure on the island continues to increase exposure and risk associated with strong ground shaking resulting from future large local earthquakes. Damaging earthquakes over the last fifty years have shaken the most heavily developed areas and critical infrastructure of the island to levels corresponding to at least Modified Mercalli Intensity VII. Hawai`i's most recent damaging earthquakes, the M6.7 Kiholo Bay and M6.0 Mahukona earthquakes, struck within seven minutes of one another off of the northwest coast of the island in October 2006. These earthquakes resulted in damage at all thirteen of the telescopes near the summit of Mauna Kea that led to gaps in telescope operations ranging from days up to four months. With the experiences of 2006 and Hawai`i's history of damaging earthquakes, we have begun a study to explore the feasibility of implementing earthquake early warning systems to provide advanced warnings to the Thirty Meter Telescope of imminent strong ground shaking from future local earthquakes. One of the major challenges for earthquake early warning in Hawai`i is the variety of earthquake sources, from shallow crustal faults to deeper mantle sources, including the basal decollement separating the volcanic pile from the ancient oceanic crust. Infrastructure on the Island of Hawai`i may only be tens of kilometers from these sources, allowing warning times of only 20 s or less. We assess the capability of the current seismic network to produce alerts for major historic earthquakes, and we will provide recommendations for upgrades to improve performance.

Development of lava tubes in the light of observations at Mauna Ulu, Kilauea Volcano, Hawaii

Science.gov (United States)

Peterson, D.W.; Holcomb, R.T.; Tilling, R.I.; Christiansen, R.L.

1994-01-01

During the 1969-1974 Mauna Ulu eruption on Kilauea's upper east rift zone, lava tubes were observed to develop by four principal processes: (1) flat, rooted crusts grew across streams within confined channels; (2) overflows and spatter accreted to levees to build arched roofs across streams; (3) plates of solidified crust floating downstream coalesced to form a roof; and (4) pahoehoe lobes progressively extended, fed by networks of distributaries beneath a solidified crust. Still another tube-forming process operated when pahoehoe entered the ocean; large waves would abruptly chill a crust across the entire surface of a molten stream crossing through the surf zone. These littoral lava tubes formed abruptly, in contrast to subaerial tubes, which formed gradually. All tube-forming processes were favored by low to moderate volume-rates of flow for sustained periods of time. Tubes thereby became ubiquitous within the pahoehoe flows and distributed a very large proportionof the lava that was produced during this prolonged eruption. Tubes transport lava efficiently. Once formed, the roofs of tubes insulate the active streams within, allowing the lava to retain its fluidity for a longer time than if exposed directly to ambient air temperature. Thus the flows can travel greater distances and spread over wider areas. Even though supply rates during most of 1970-1974 were moderate, ranging from 1 to 5 m3/s, large tube systems conducted lava as far as the coast, 12-13 km distant, where they fed extensive pahoehoe fields on the coastal flats. Some flows entered the sea to build lava deltas and add new land to the island. The largest and most efficient tubes developed during periods of sustained extrusion, when new lava was being supplied at nearly constant rates. Tubes can play a major role in building volcanic edifices with gentle slopes because they can deliver a substantial fraction of lava erupted at low to moderate rates to sites far down the flank of a volcano. We

State of the climate in 2015

NARCIS (Netherlands)

Aaron-Morrison, Arlene P.; Ackerman, Steven A.; Adams, Nicolaus G.; Adler, Robert F.; Albanil, Adelina; Alfaro, Eric J.; Allan, Rob; Alves, Lincoln M.; Amador, Jorge A.; Andreassen, L. M.; Arendt, A.; Arévalo, Juan; Arndt, Derek S.; Arzhanova, N. M.; Aschan, M. M.; Azorin-Molina, César; Banzon, Viva; Bardin, M. U.; Barichivich, Jonathan; Baringer, Molly O.; Barreira, Sandra; Baxter, Stephen; Bazo, Juan; Becker, Andreas; Bedka, Kristopher M.; Behrenfeld, Michael J.; Bell, Gerald D.; Belmont, M.; Benedetti, Angela; Bernhard, G.; Berrisford, Paul; Berry, David I.; Bettolli, María L.; Bhatt, Uma S.; Bidegain, Mario; Bill, Brian D.; Billheimer, Sam; Bissolli, Peter; Blake, Eric S.; Blunden, Jessica; Bosilovich, Michael G.; Boucher, Olivier; Boudet, Dagne R.; Box, Jason E.; Boyer, Tim; Braathen, Geir O.; Bromwich, David H.; Brown, R.; Bulygina, Olga N.; Burgess, D.; Calderón, Blanca; Camargo, Suzana J.; Campbell, Jayaka D.; Cappelen, J.; Carrasco, Gualberto; Carter, Brendan R.; Chambers, Don P.; Chandler, Elise; Christiansen, Hanne H.; Christy, John R.; Chung, Daniel; Chung, E.S.; Cinque, Kathy; Clem, Kyle R.; Coelho, Caio A.; Cogley, J.G.; Coldewey-Egbers, Melanie; Colwell, Steve; Cooper, Owen R.; Copland, L.; Cosca, Catherine E.; Cross, Jessica N.; Crotwell, Molly J.; Crouch, Jake; Davis, Sean M.; De Eyto, Elvira; De Jeu, Richard A.M.; De Laat, Jos; Degasperi, Curtis L.; Degenstein, Doug; Demircan, M.; Derksen, C.; Destin, Dale; Di Girolamo, Larry; Di Giuseppe, F.; Diamond, Howard J.; Dlugokencky, Ed J.; Dohan, Kathleen; Dokulil, Martin T.; Dolgov, A. V.; Dolman, A. Johannes; Domingues, Catia M.; Donat, Markus G.; Dong, Shenfu; Dorigo, Wouter A.; Dortch, Quay; Doucette, Greg; Drozdov, Dmitry S.; Ducklow, Hugh; Dunn, Robert J.H.; Durán-Quesada, Ana M.; Dutton, Geoff S.; Ebrahim, A.; Elkharrim, M.; Elkins, James W.; Espinoza, Jhan C.; Etienne-Leblanc, Sheryl; Evans, Thomas E.; Famiglietti, James S.; Farrell, S.A.; Fateh, S.; Fausto, Robert S.; Fedaeff, Nava; Feely, Richard A.; Feng, Z.; Fenimore, Chris; Fettweis, Xavier; Fioletov, Vitali E.; Flemming, Johannes; Fogarty, Chris T.; Fogt, Ryan L.; Folland, Chris; Fonseca, C.; Fossheim, M.; Foster, Michael J.; Fountain, Andrew; Francis, S. D.; Franz, Bryan A.; Frey, Richard A.; Frith, Stacey M.; Froidevaux, Lucien; Ganter, Catherine; Garzoli, Silvia; Gerland, S.; Gobron, Nadine; Goldenberg, Stanley B.; Gomez, R. Sorbonne; Goni, Gustavo J.; Goto, A.; Grooß, J. U.; Gruber, Alexander; Guard, Charles Chip; Gugliemin, Mauro; Gupta, S. K.; Gutiérrez, J. M.; Hagos, S.; Hahn, Sebastian; Haimberger, Leo; Hakkarainen, J.; Hall, Brad D.; Halpert, Michael S.; Hamlington, Benjamin D.; Hanna, E.Y.; Hansen, K.; Hanssen-Bauer, I.; Harris, Ian A; Heidinger, Andrew K.; Heikkilä, A.; Heil, A.; Heim, Richard R., Jr.; Hendricks, S.; Hernández, Marieta; Hidalgo, Hugo G.; Hilburn, Kyle; Ho, Shu Peng Ben; Holmes, R. Max; Hu, Zeng Zhen; Huang, Boyin; Huelsing, Hannah K.; Huffman, George J.; Hughes, N.C.; Hurst, Dale F.; Ialongo, I.; Ijampy, J. A.; Ingvaldsen, R. B.; Inness, Antje; Isaksen, K.; Ishii, Masayoshi; Jevrejeva, Svetlana; Jiménez, C.; Jin, Xiangze; Johannesen, E.; John, Viju; Borch-Johnsen, K.; Johnson, Bryan; Johnson, Gregory C.; Jones, Philip D.; Joseph, Annie C.; Jumaux, Guillaume; Kabidi, Khadija; Kaiser, Johannes W.; Kato, Seiji; Kazemi, A.; Keller, Linda M.; Kendon, Mike; Kennedy, John J.; Kerr, Kenneth; Kholodov, A. L.; Khoshkam, Mahbobeh; Killick, Rachel; Kim, Hyungjun; Kim, S. J.; Kimberlain, Todd B.; Klotzbach, Philip J.; Knaff, John A.; Kobayashi, Shinya; Kohler, J.; Korhonen, Johanna; Korshunova, Natalia N.; Kovacs, K.M.; Kramarova, Natalya; Kratz, David P.; Kruger, Andries; Kruk, Michael C.; Kudela, Raphael; Kumar, Arun; Lakatos, M.; Lakkala, K.; Lander, Mark A.; Landsea, Chris W.; Lankhorst, Matthias; Lantz, Kathleen; Lazzara, Matthew A.; Lemons, P.; Leuliette, Eric; L’Heureux, Michelle; Lieser, Jan L.; Lin, I. I.; Liu, Hongxing; Liu, Yinghui; Locarnini, Ricardo; Loeb, Norman G.; Lo Monaco, Claire; Long, Craig S.; López Álvarez, Luis Alfonso; Lorrey, Andrew M.; Loyola, Diego; Lumpkin, Rick; Luo, Jing-Jia; Luojus, K.; Lydersen, C.; Lyman, John M.; Maberly, Stephen C.; Maddux, Brent C.; Malheiros Ramos, Andrea; Malkova, G. V.; Manney, G.L.; Marcellin, Vernie; Marchenko, Sergey; Marengo, José A.; Marra, John J.; Marszelewski, Wlodzimierz; Martens, B.; Martínez-Güingla, Rodney; Massom, Robert A.; Mata, Mauricio M.; Mathis, Jeremy T.; May, Linda; Mayer, Michael; Mazloff, Matthew; McBride, Charlotte; McCabe, M.F.; McCarthy, M.; McClelland, J.W.; McGree, Simon; McVicar, Tim R.; Mears, Carl A.; Meier, Walt; Meinen, Christopher S.; Mekonnen, A.; Menéndez, Melisa; Mengistu Tsidu, G.; Menzel, W. Paul; Merchant, Christopher J.; Meredith, Michael P.; Merrifield, Mark A.; Metzl, N.; Minnis, Patrick; Miralles, Diego G.; Mistelbauer, T.; Mitchum, Gary T.; Monselesan, Didier; Monteiro, Pedro M S; Montzka, Stephen A.; Morice, Colin; Mote, Thomas; Mudryk, L.; Mühle, Jens; Mullan, A. Brett; Nash, Eric R.; Naveira-Garabato, Alberto C.; Nerem, Steven R.; Newman, Paul A.; Nieto, Juan José; Noetzli, Jeannette; O’Neel, S.; Osborn, Tim J.; Overland, James; Oyunjargal, Lamjav; Parinussa, Robert M.; Park, E. Hyung; Parker, David; Parrington, M.; Parsons, A. Rost; Pasch, Richard J.; Pascual-Ramírez, Reynaldo; Paterson, Andrew M.; Paulik, Christoph; Pearce, Petra R.; Pelto, Mauri S.; Peng, Liang; Perkins-Kirkpatrick, Sarah E.; Perovich, Donald; Petropavlovskikh, Irina; Pezza, Alexandre B.; Phillips, David; Pinty, Bernard; Pitts, Michael C.; Pons, M. R.; Porter, Avalon O.; Primicerio, R.; Proshutinsky, A.; Quegan, Sean; Quintana, Juan; Rahimzadeh, Fatemeh; Rajeevan, Madhavan; Randriamarolaza, L.; Razuvaev, Vyacheslav N.; Reagan, James R.; Reid, Phillip; Reimer, Christoph; Rémy, Samuel; Renwick, James A.; Revadekar, Jayashree V.; Richter-Menge, Jacqueline; Riffler, Michael; Rimmer, Alon; Rintoul, Steve; Robinson, David A.; Rodell, Matthew; Rodríguez Solís, José L.; Romanovsky, Vladimir E.; Ronchail, Josyane; Rosenlof, Karen H.; Roth, Chris; Rusak, James A.; Sabine, Christopher L.; Sallée, Jean Bapiste; Sánchez-Lugo, Ahira; Santee, Michelle L.; Sawaengphokhai, P.; Sayouri, Amal; Scambos, Ted A.; Schemm, Jae; Schladow, S. Geoffrey; Schmid, Claudia; Schmid, Martin; Schmidtko, Sunke; Schreck, Carl J.; Selkirk, H. B.; Send, Uwe; Sensoy, Serhat; Setzer, Alberto; Sharp, M.; Shaw, Adrian; Shi, Lei; Shiklomanov, A. I.; Shiklomanov, Nikolai I.; Siegel, David A.; Signorini, Sergio R.; Sima, Fatou; Simmons, Adrian J.; Smeets, C. J.P.P.; Smith, Sharon L.; Spence, Jaqueline M.; Srivastava, A. K.; Stackhouse, Paul W., Jr.; Stammerjohn, Sharon; Steinbrecht, Wolfgang; Stella, José L.; Stengel, Martin; Stennett-Brown, Roxann; Stephenson, Tannecia S.; Strahan, Susan; Streletskiy, D. A.; Sun-Mack, Sunny; Swart, Sebastiaan; Sweet, William; Talley, Lynne D.; Tamar, Gerard; Tank, S.E.; Taylor, Michael A.; Tedesco, M.; Teubner, Katrin; Thoman, R. L.; Thompson, Philip; Thomson, L.; Timmermans, M. L.; Tirnanes, Joaquin A.; Tobin, Skie; Trachte, Katja; Trainer, Vera L.; Tretiakov, M.; Trewin, Blair C.; Trotman, Adrian R.; Tschudi, M.; van As, D.; van de Wal, R.S.W.; van der A, Ronald J.; Van Der Schalie, Robin; Van Der Schrier, Gerard; Van Der Werf, Guido R.; Van Meerbeeck, Cedric J.; Velicogna, I.; Verburg, Piet; Vigneswaran, Bala; Vincent, Lucie A.; Volkov, Denis; Vose, Russell S.; Wagner, Wolfgang; Wåhlin, Anna; Wahr, John; Walsh, John; Wang, Chunzai; Wang, Junhong; Wang, Lei; Wang, M.; Wang, Sheng-Hung; Wanninkhof, Rik; Watanabe, Shohei; Weber, Mark; Weller, Robert A.; Weyhenmeyer, Gesa A.; Whitewood, Robert; Wijffels, Susan E.; Wilber, Anne C.; Wild, Jeanette D.; Willett, Kate M.; Williams, Michael J.M.; Willie, Shem; Wolken, Gabriel; Wong, Takmeng; Wood, E. F.; Woolway, R. Iestyn; Wouters, B.; Xue, Yan; Yamada, Ryuji; Yim, So Young; Yin, Xungang; Young, Steven H.; Yu, Lisan; Zahid, H.; Zambrano, Eduardo; Zhang, Peiqun; Zhao, Guanguo; Zhou, Lin; Ziemke, Jerry R.; Love-Brotak, S. Elizabeth; Gilbert, Kristin; Maycock, Tom; Osborne, Susan; Sprain, Mara; Veasey, Sara W.; Ambrose, Barbara J.; Griffin, Jessicca; Misch, Deborah J.; Riddle, Deborah B.; Young, Teresa

2016-01-01

In 2015, the dominant greenhouse gases released into Earth’s atmosphere—carbon dioxide, methane, and nitrous oxide—all continued to reach new high levels. At Mauna Loa, Hawaii, the annual CO2 concentration increased by a record 3.1 ppm, exceeding 400 ppm for the first time on record. The 2015 global

ANSTO radon monitoring within the WMO global atmosphere watch programme

International Nuclear Information System (INIS)

Zahorowski, W.; Chambers, S.; Sisoutham, O.; Werczynski, S.

2003-01-01

A brief overview of results from the ANSTO radon programmes at the Cape Grim (Tasmania) and Mauna Loa Observatory (Hawaii), World Meteorological Organisation Global Atmosphere Watch stations it presented. At Cape Grim, a 100 mBq m 3 threshold on radon concentration observations has proven to be a suitable criterion for Baseline monitoring. Furthermore, analysis of the Cape Grim Baseline radon data has enabled the characterisation of the oceanic radon flux over the Southern Ocean Cape Grim fetch region. Radon observations at the Mauna Loa Observatory, in conjunction with back trajectory analysis, have helped to identify the source regions of the most pervasive pollution events in the atmosphere of the Pacific Basin. The seasonal variability in the strength of terrestrial influence on Pacific air masses has also been characterised

Shifts in bryophyte carbon isotope ratio across an elevation × soil age matrix on Mauna Loa, Hawaii: do bryophytes behave like vascular plants?

Science.gov (United States)

Waite, Mashuri; Sack, Lawren

2011-05-01

The carbon isotope ratio (δ(13)C) of vascular plant leaf tissue is determined by isotope discrimination, primarily mediated by stomatal and mesophyll diffusion resistances and by photosynthetic rate. These effects lead to predictable trends in leaf δ(13)C across natural gradients of elevation, irradiance and nutrient supply. Less is known about shifts in δ(13)C for bryophytes at landscape scale, as bryophytes lack stomata in the dominant gametophyte phase, and thus lack active control over CO(2) diffusion. Twelve bryophyte species were sampled across a matrix of elevation and soil ages on Mauna Loa, Hawaii Island. We tested hypotheses based on previous findings for vascular plants, which tend to have less negative δ(13)C at higher elevations or irradiances, and for leaves with higher leaf mass per area (LMA). Across the matrix, bryophytes spanned the range of δ(13)C values typical of C(3) vascular plants. Bryophytes were remarkably similar to vascular plants in exhibiting less negative δ(13)C with increasing elevation, and with lower overstory cover; additionally δ(13)C was related to bryophyte canopy projected mass per area, a trait analogous to LMA in vascular plants, also correlated negatively with overstory cover. The similarity of responses of δ(13)C in bryophytes and vascular plants to environmental factors, despite differing morphologies and diffusion pathways, points to a strong direct role of photosynthetic rate in determining δ(13)C variation at the landscape scale.

Mauna Kea, Hawaii as an Analogue Site for Future Planetary Resource Exploration: Results from the 2010 ILSO-ISRU Field-Testing Campaign

Science.gov (United States)

ten Kate, I. L.; Armstrong, R.; Bernhardt, B.; Blummers, M.; Boucher, D.; Caillibot, E.; Captain, J.; Deleuterio, G.; Farmer, J. D.; Glavin, D. P.;

Diet of feral cats in Hawai'i Volcanoes National Park

Science.gov (United States)

Hess, S.C.; Hansen, H.; Nelson, D.; Swift, R.; Banko, P.C.

2007-01-01

We documented the diet of feral cats by analysing the contents of 42 digestive tracts from Kilauea and Mauna Loa in Hawai'i Volcanoes National Park. Small mammals, invertebrates, and birds were the most common prey types consumed by feral cats. Birds occurred in 27.8-29.2% of digestive tracts. The total number of bird, small mammal, and invertebrate prey differed between Kilauea and Mauna Loa. On Mauna Loa, significantly more (89%) feral cats consumed small mammals, primarily rodents, than on Kilauea Volcano (50%). Mice (Mus musculus) were the major component of the feral cat diet on Mauna Loa, whereas Orthoptera were the major component of the diet on Kilauea. We recovered a mandible set, feathers, and bones of an endangered Hawaiian Petrel (Pterodroma sandwichensis) from a digestive tract from Mauna Loa. This specimen represents the first well-documented endangered seabird to be recovered from the digestive tract of a feral cat in Hawai'i and suggests that feral cats prey on this species.

Long range transport of CO and ozone from source regions in Asia

Energy Technology Data Exchange (ETDEWEB)

Jaffe, D.; Mahura, A. [Univ. of Alaska, Fairbanks, AK (United States)]|[Institute of Northern Ecological Problems, Moscow (Russian Federation); Novelli, P. [Univ. of Colorado, Boulder, CO (United States); Merrill, J. [Univ. of Rhode Island, Narraganset, RI (United States)

1996-12-31

Based on current understanding of the atmosphere, CO and photochemically produced ozone can be transported thousands of kilometers prior to being removed. Emissions from Asia have a possible impact on the CO and ozone concentrations over the U.S. west coast following transport across the Pacific Ocean. If this is correct, then there are implications for ozone control strategies in the downwind region. Evidence includes: (1) Global 3D chemical transport models indicating a monthly mean enhancement of 10-20% on the US west coast for both CO and ozone during winter-spring due to emissions from Asia; and (2) CO and O{sub 3} data from several Pacific sites which demonstrate that Asian pollutants can be transported great distances. The weekly flask data clearly define a CO seasonal cycle. In the present analysis we use a locally weighted smoothing technique to identify individual data outliers from the smoothed seasonal cycle. We hypothesize that these outliers represent periods when continental emissions influenced the atmospheric mixing ratios at these locations. Using isentropic back trajectories we try to identify a possible source region or pathway for each event and present a distribution of the trajectory types for the events. For the events at Midway, Mauna Loa, Guam and Shemya, we are able to identify a source region for elevated CO in 82, 72, 65 and 50% of the events, respectively. At Mauna Loa and Midway a majority of the events occur during spring and are mostly associated with transport from Asia. These events bring the highest CO mixing ratios observed at any time during the year to these sites, with CO enhancements up to 46 ppb. For Mauna Loa, a small number of events during summer are due to transport from North and Central America. In-situ ozone from Mauna Loa also demonstrates an impact from Asian emissions.

Observations of carbon dioxide, methane, and carbon monoxide at Tae-Ahn peninsula (Korea), Mount Waliguan (China), Ulaan Uul (Mongolia) and at Mauna Loa (Hawaii USA)

Energy Technology Data Exchange (ETDEWEB)

Chung, Y.S. [Korea National Univ. of Education, Chongwon (Korea, Republic of); Tans, P.P.; Conway, T.J.; Dlugokencky, E.J. [Climate Monitoring and Diagnostics Lab., Bouler (United States); Novelli, P.C.; Tolier, M. [Colorado Univ. (United States). Cooperative Inst. for Research in Environmental Sciences; Wen, Y. [Chinese Academy of Meteorological Sciences, Beijing (China); Dagvadorj, D. [Mongolian Hydrometeorological Research Inst., Ulaan Batar (Mongolia)

1995-12-31

It has been discussed that the greenhouse gases, e.g. carbon dioxide (CO{sub 2}) methane (CH{sub 4}), enhance warming in the biosphere. Many scientists are therefore interested in monitoring the minor constituents of the atmosphere and in the carbon cycle. In cooperation with the Climate Monitoring and Diagnostics Laboratory (CMDL) of U.S. National Oceanic and Atmospheric Administration (NOAA), CO{sub 2}, CH{sub 4} and carbon monoxide (CO) at the western tip of the Tae-ahn Peninsula (TAP) in central Korea since October 1990 has been measured. Shortly thereafter, two more sites were added for the measurement of greenhouse gases in East Asia; one at Mount Waliguar Qinghai Province (QPC) in China and another at Ulaan Uul (UUM), the Gobi Desert in Mongolia. Also, trace gas data obtained at Mauna Loa (MLO) in Hawaii in the USA has been used. The Hawaiian data represent the world`s longest period of CO{sub 2} monitoring since 1958. The present monitoring is a part of the Global Air Sampling Network the WMO`s Global Atmospheric Watch. The method of collecting and measuring CO{sub 2}, CO and CH{sub 4} have been described else where. Here the four year monitoring of the trace gases at the three sites in East Asia is reported. The results are also compared with the measured values obtained at the free troposphere background site at MLO in Hawaii

Observations of carbon dioxide, methane, and carbon monoxide at Tae-Ahn peninsula (Korea), Mount Waliguan (China), Ulaan Uul (Mongolia) and at Mauna Loa (Hawaii USA)

Energy Technology Data Exchange (ETDEWEB)

Chung, Y S [Korea National Univ. of Education, Chongwon (Korea, Republic of); Tans, P P; Conway, T J; Dlugokencky, E J [Climate Monitoring and Diagnostics Lab., Bouler (United States); Novelli, P C; Tolier, M [Colorado Univ. (United States). Cooperative Inst. for Research in Environmental Sciences; Wen, Y [Chinese Academy of Meteorological Sciences, Beijing (China); Dagvadorj, D [Mongolian Hydrometeorological Research Inst., Ulaan Batar (Mongolia)

1996-12-31

It has been discussed that the greenhouse gases, e.g. carbon dioxide (CO{sub 2}) methane (CH{sub 4}), enhance warming in the biosphere. Many scientists are therefore interested in monitoring the minor constituents of the atmosphere and in the carbon cycle. In cooperation with the Climate Monitoring and Diagnostics Laboratory (CMDL) of U.S. National Oceanic and Atmospheric Administration (NOAA), CO{sub 2}, CH{sub 4} and carbon monoxide (CO) at the western tip of the Tae-ahn Peninsula (TAP) in central Korea since October 1990 has been measured. Shortly thereafter, two more sites were added for the measurement of greenhouse gases in East Asia; one at Mount Waliguar Qinghai Province (QPC) in China and another at Ulaan Uul (UUM), the Gobi Desert in Mongolia. Also, trace gas data obtained at Mauna Loa (MLO) in Hawaii in the USA has been used. The Hawaiian data represent the world`s longest period of CO{sub 2} monitoring since 1958. The present monitoring is a part of the Global Air Sampling Network the WMO`s Global Atmospheric Watch. The method of collecting and measuring CO{sub 2}, CO and CH{sub 4} have been described else where. Here the four year monitoring of the trace gases at the three sites in East Asia is reported. The results are also compared with the measured values obtained at the free troposphere background site at MLO in Hawaii

Propuesta de proyecto de estadística: un modelo de regresión lineal simple para pronosticar la concentración de co2 del volcán Mauna Loa

Directory of Open Access Journals (Sweden)

Claudio Alfredo López Miranda

2014-12-01

Full Text Available Este trabajo aplica un modelo predictivo de regresión lineal para analizar la contaminación atmosférica de dióxido de carbono (CO2 producida por el volcán Mauna Loa de Hawái. Los datos fueron extraídos de un repositorio de internet que contiene múltiples casos de geología, climatología, física, etcétera. El modelo se utilizó para predecir la tendencia de emisiones de CO2 con respecto al tiempo; se estimó la contaminación promedio de dicha tendencia, la cual descubrimos ha crecido aproximadamente 0.1 partes por millón por mes; así como también se obtuvieron los intervalos de predicción para una emisión puntual que existió en un momento determinado. Se recomienda el trabajo para estudiantes de ciencias exactas y naturales, como prototipo de artículo de investigación donde se aplique específicamente el modelo de regresión lineal simple; aunque la estructura también puede servir en otras áreas donde se enseñen los modelos de regresión.

Island of Hawaii, State of Hawaii seen from Skylab

Science.gov (United States)

1974-01-01

A vertical view of the Island of Hawaii, State of Hawaii (19.5N, 155.5W), as photographed from the Skylab space station in Earth orbit by a Skylab 4 crewman. This photograph, taken on January 8, 1974, is very useful in studies of volcanic areas. Prominent volcanic features such as the summit caldera on Mauna Loa, the extinct volcano Mauna Kea, the Kilauea caldera, and the pit crater at Halo Mau Mau within the caldera are easily identified. Kilauea was undergoing frequent eruption during the mission. Detailed features such as the extent and delineation of historic lava flows on Mauna Loa can be determined and are important parameters in volcanic studies.

Decline of Ohia (Metrosideros polymorpha) in Hawaii: a review

Science.gov (United States)

Charles S. Hodges; Ken T. Adee; John D. Stein; Hulton B. Wood; Robert D. Doty

1986-01-01

Portions of the ohia (Metrosideros polymorpha) forests on the windward slopes of Mauna Loa and Mauna Kea on the island of Hawaii began dying in 1952. Little mortality has occurred since 1972. About 50,000 ha are affected by the decline. Individual trees exhibit several symptoms, from slow progressive dieback to rapid death. Seven types of decline...

Origin and depositional environment of clastic deposits in the Hilo drill hole, Hawaii

Science.gov (United States)

Beeson, M.H.; Clague, D.A.; Lockwood, J.P.

1996-01-01

Volcaniclastic units cored at depths of about 87, 164, 178, 226, and 246 m below sea level and carbonate units located between depths of 27 and 53 m below sea level in the Hilo drill core were found to be deposited at or near sea level. Four of these units are hydroclastic deposits, formed when subaerially erupted Mauna Loa lava flows entered the ocean and fragmented to produce quenched, glassy fragments during hydrovolcanic explosions. Ash units 24 and 26, at 178 m depth, accumulated at sea level in a freshwater bog. They contain pyroxenes crystallized from tholeiitic magma that we infer erupted explosively at the summit of Kilauea volcano. Two carbon-rich layers from these ashes have a weighted average radiocarbon age of 38.6 ?? 0.9 ka; the ashes probably correlate with the oldest and thickest part of the Pahala ash. Ash unit 44, at the transition from Mauna Kea to Mauna Loa lava flows, was probably nearly 3.2 m thick and is inferred to be equivalent to the lower thick part of the composite Homelani ash mapped in Hilo and on the flanks of Mauna Kea. The age of this part of Homelani ash is between 128 ?? 33 and 200 ?? 10 ka; it may have erupted subglacially during the Pohakuloa glacial maxima on Mauna Kea. Beach sand units 12 and 22 were derived from nearby Mauna Loa and Mauna Kea lava flows. The middle of beach sand unit 38 was derived mainly from lava erupted near the distal end of the subaerial east rift zone of Kilauea volcano; these sands were transported about 33 km northwest to Hilo Bay by prevailing longshore currents. Combined age, depth, and sea level markers in the core allow us to determine that lava flow recurrence intervals averaged one flow every 4 kyr during the past 86 kyr and one flow every 16 kyr between 86 and 200 ka at the drill site and that major explosive eruptions that deposit thick ash in Hilo have occurred only twice in the last 400 kyr. These recurrence intervals support the moderate lava flow hazard zonation (zone 3) for coastal Hilo

The 40Ar/39Ar dating of core recovered by the Hawaii Scientific Drilling Project (phase 2), Hilo, Hawaii

Science.gov (United States)

Sharp, Warren D.; Renne, Paul R.

2005-04-01

The Hawaii Scientific Drilling Project, phase 2 (HSDP-2), recovered core from a ˜3.1-km-thick section through the eastern flanks of Mauna Loa and Mauna Kea volcanoes. We report results of 40Ar/39Ar incremental heating by broad-beam infrared laser of 16 basaltic groundmass samples and 1 plagioclase separate, mostly from K-poor tholeiites. The tholeiites generally have mean radiogenic 40Ar enrichments of 1-3%, and some contain excess 40Ar; however, isochron ages of glass-poor samples preserve stratigraphic order in all cases. A 246-m-thick sequence of Mauna Loa tholeiitic lavas yields an isochron age of 122 ± 86 kyr (all errors 2σ) at its base. Beneath the Mauna Loa overlap sequence lie Mauna Kea's postshield and shield sequences. A postshield alkalic lava yields an age of 236 ± 16 kyr, in agreement with an age of 240 ± 14 kyr for a geochemically correlative flow in the nearby HSDP-1 core hole, where more complete dating of the postshield sequence shows it to have accumulated at 0.9 ± 0.4 m/kyr, from about 330 to <200 ka. Mauna Kea's shield consists of subaerial tholeiitic flows to a depth of 1079 m below sea level, then shallow submarine flows, hyaloclastites, pillow lavas, and minor intrusions to core bottom at 3098 m. Most subaerial tholeiitic flows fail to form isochrons; however, a sample at 984 m yields an age of 370 ± 180 kyr, consistent with ages from similar levels in HSDP-1. Submarine tholeiites including shallow marine vitrophyres, clasts from hyaloclastites, and pillow lavas were analyzed; however, only pillow lava cores from 2243, 2614, and 2789 m yield reliable ages of 482 ± 67, 560 ± 150, and 683 ± 82 kyr, respectively. A linear fit to ages for shield samples defines a mean accumulation rate of 8.6 ± 3.1 m/kyr and extrapolates to ˜635 kyr at core bottom. Alternatively, a model relating Mauna Kea's growth to transport across the Hawaiian hot spot that predicts downward accelerating accumulation rates that reach ˜20 m/kyr at core bottom (De

Lava flow field emplacement studies of Manua Ulu (Kilauea Volcano, Hawai'i, United States) and Venus, using field and remote sensing analyses

Science.gov (United States)

Byrnes, Jeffrey Myer

2002-04-01

This work examines lava emplacement processes by characterizing surface units using field and remote sensing analyses in order to understand the development of lava flow fields. Specific study areas are the 1969--1974 Mauna Ulu compound flow field, (Kilauea Volcano, Hawai'i, USA), and five lava flow fields on Venus: Turgmam Fluctus, Zipaltonal Fluctus, the Tuli Mons/Uilata Fluctus flow complex, the Var Mons flow field, and Mylitta Fluctus. Lava surface units have been examined in the field and with visible-, thermal-, and radar-wavelength remote sensing datasets for Mauna Ulu, and with radar data for the Venusian study areas. For the Mauna Ulu flow field, visible characteristics are related to color, glass abundance, and dm- to m-scale surface irregularities, which reflect the lava flow regime, cooling, and modification due to processes such as coalescence and inflation. Thermal characteristics are primarily affected by the abundance of glass and small-scale roughness elements (such as vesicles), and reflect the history of cooling, vesiculation and degassing, and crystallization of the lava. Radar characteristics are primarily affected by unit topography and fracturing, which are related to flow inflation, remobilization, and collapse, and reflect the local supply of lava during and after unit emplacement. Mauna Ulu surface units are correlated with pre-eruption topography, lack a simple relationship to the main feeder lava tubes, and are distributed with respect to their position within compound flow lobes and with distance from the vent. The Venusian lava flow fields appear to have developed through emplacement of numerous, thin, simple and compound flows, presumably over extended periods of time, and show a wider range of radar roughness than is observed at Mauna Ulu. A potential correlation is suggested between flow rheology and surface roughness. Distributary flow morphologies may result from tube-fed flows, and flow inflation is consistent with observed

Inter-annual variability of the atmospheric carbon dioxide concentrations as simulated with global terrestrial biosphere models and an atmospheric transport model

Energy Technology Data Exchange (ETDEWEB)

Fujita, Daisuke; Saeki, Tazu; Nakazawa, Takakiyo [Tohoku Univ., Sendai (Japan). Center for Atmospheric and Oceanic Studies; Ishizawa, Misa; Maksyutov, Shamil [Inst. for Global Change Research, Yokohama (Japan). Frontier Research System for Global Change; Thornton, Peter E. [National Center for Atmospheric Research, Boulder, CO (United States). Climate and Global Dynamics Div.

2003-04-01

Seasonal and inter-annual variations of atmospheric CO{sub 2} for the period from 1961 to 1997 have been simulated using a global tracer transport model driven by a new version of the Biome BioGeochemical Cycle model (Biome-BGC). Biome-BGC was forced by daily temperature and precipitation from the NCEP reanalysis dataset, and the calculated monthly-averaged CO{sub 2} fluxes were used as input to the global transport model. Results from an inter-comparison with the Carnegie-Ames-Stanford Approach model (CASA) and the Simulation model of Carbon CYCLE in Land Ecosystems (Sim-CYCLE) model are also reported. The phase of the seasonal cycle in the Northern Hemisphere was reproduced generally well by Biome-BGC, although the amplitude was smaller compared to the observations and to the other biosphere models. The CO{sub 2} time series simulated by Biome-BGC were compared to the global CO{sub 2} concentration anomalies from the observations at Mauna Loa and the South Pole. The modeled concentration anomalies matched the phase of the inter-annual variations in the atmospheric CO{sub 2} observations; however, the modeled amplitude was lower than the observed value in several cases. The result suggests that a significant part of the inter-annual variability in the global carbon cycle can be accounted for by the terrestrial biosphere models. Simulations performed with another climate-based model, Sim-CYCLE, produced a larger amplitude of inter-annual variability in atmospheric CO{sub 2}, making the amplitude closer to the observed range, but with a more visible phase mismatch in a number of time periods. This may indicate the need to increase the Biome-BGC model sensitivity to seasonal and inter-annual changes in temperature and precipitation.

Inter-annual variability of the atmospheric carbon dioxide concentrations as simulated with global terrestrial biosphere models and an atmospheric transport model

International Nuclear Information System (INIS)

Fujita, Daisuke; Saeki, Tazu; Nakazawa, Takakiyo; Ishizawa, Misa; Maksyutov, Shamil; Thornton, Peter E.

2003-01-01

Seasonal and inter-annual variations of atmospheric CO 2 for the period from 1961 to 1997 have been simulated using a global tracer transport model driven by a new version of the Biome BioGeochemical Cycle model (Biome-BGC). Biome-BGC was forced by daily temperature and precipitation from the NCEP reanalysis dataset, and the calculated monthly-averaged CO 2 fluxes were used as input to the global transport model. Results from an inter-comparison with the Carnegie-Ames-Stanford Approach model (CASA) and the Simulation model of Carbon CYCLE in Land Ecosystems (Sim-CYCLE) model are also reported. The phase of the seasonal cycle in the Northern Hemisphere was reproduced generally well by Biome-BGC, although the amplitude was smaller compared to the observations and to the other biosphere models. The CO 2 time series simulated by Biome-BGC were compared to the global CO 2 concentration anomalies from the observations at Mauna Loa and the South Pole. The modeled concentration anomalies matched the phase of the inter-annual variations in the atmospheric CO 2 observations; however, the modeled amplitude was lower than the observed value in several cases. The result suggests that a significant part of the inter-annual variability in the global carbon cycle can be accounted for by the terrestrial biosphere models. Simulations performed with another climate-based model, Sim-CYCLE, produced a larger amplitude of inter-annual variability in atmospheric CO 2 , making the amplitude closer to the observed range, but with a more visible phase mismatch in a number of time periods. This may indicate the need to increase the Biome-BGC model sensitivity to seasonal and inter-annual changes in temperature and precipitation

Comparison of Inflation Processes at the 1859 Mauna Loa Flow, HI, and the McCartys Flow Field, NM

Science.gov (United States)

Bleacher, Jacob E.; Garry, W. Brent; Zimbelman, James R.; Crumpler, Larry S.

2012-01-01

Basaltic lavas typically form channels or tubes during flow emplacement. However, the importance of sheet flow in the development of basalt ic terrains received recognition over the last 15 years. George Walke r?s research on the 1859 Mauna Loa Flow was published posthumously in 2009. In this paper he discusses the concept of endogenous growth, or inflation, for the distal portion of this otherwise channeldominated lava flow. We used this work as a guide when visiting the 1859 flow to help us better interpret the inflation history of the McCartys flow field in NM. Both well preserved flows display similar clues about the process of inflation. The McCartys lava flow field is among the you ngest (approx.3000 yrs) basaltic lava flows in the continental United States. It was emplaced over slopes of <1 degree, which is similar to the location within the 1859 flow where inflation occurred. Although older than the 1859 flow, the McCartys is located in an arid environ ment and is among the most pristine examples of sheet flow morphologies. At the meter scale the flow surface typically forms smooth, undula ting swales that create a polygonal terrain. The literature for simil ar features includes multiple explanatory hypotheses, original breakouts from adjacent lobes, or inflation related upwarping of crust or sa gging along fractures that enable gas release. It is not clear which of these processes is responsible for polygonal terrains, and it is po ssible that one explanation is not the sole cause of this morphology between all inflated flows. Often, these smooth surfaces within an inflated sheet display lineated surfaces and occasional squeeze-ups alon g swale contacts. We interpret the lineations to preserve original fl ow direction and have begun mapping these orientations to better interpret the emplacement history. At the scale of 10s to 100s of meters t he flow comprises multiple topographic plateaus and depressions. Some depressions display level floors with

Metrology of the Solar Spectral Irradiance at the Top Of Atmosphere in the Near Infrared using Ground Based Instruments. Final results of the PYR-ILIOS campaign (Mauna Loa Observatory, June-July 2016).

Science.gov (United States)

Cessateur, G.; Bolsée, D.; Pereira, N.; Sperfeld, P.; Pape, S.

2017-12-01

The availability of reference spectra for the Solar Spectral Irradiance (SSI) is important for the solar physics, the studies of planetary atmospheres and climatology. The near infrared (NIR) part of these spectra is of great interest for its main role for example, in the Earth's radiative budget. Until recently, some large and unsolved discrepancies (up to 10 %) were observed in the 1.6 μm region between space instruments, models and ground-based measurements. We designed a ground-based instrumentation for SSI measurements at the Top Of Atmosphere (TOA) through atmospheric NIR windows using the Bouguer-Langley technique. The main instrument is a double NIR spectroradiometer designed by Bentham (UK), radiometrically characterized at the Royal Belgian Institute for Space Aeronomy. It was absolute calibrated against a high-temperature blackbody as primary standard for spectral irradiance at the Physikalisch-Technische Bundesanstalt (Germany). The PYR-ILIOS campaign was carried out in June to July 2016 at the Mauna Loa Observatory (Hawaii, USA, 3396 m a.s.l.) follows the four-month IRESPERAD campaign which was carried out in the summer 2011 at the Izaña Atmospheric Observatory (Canary Islands, 2367 m a.s.l.). We present here the results of the 3'week PYR-ILIOS campaign and compare them with the ATLAS 3 spectrum as well as from recently reprocessed NIR solar spectra obtained with SOLAR/SOLSPEC on ISS and SCIAMACHY on ENVISAT. The uncertainty budget of the PYR-ILIOS results will be discussed.

Petrologic insights into basaltic volcanism at historically active Hawaiian volcanoes: Chapter 6 in Characteristics of Hawaiian volcanoes

Science.gov (United States)

Helz, Rosalind L.; Clague, David A.; Sisson, Thomas W.; Thornber, Carl R.; Poland, Michael P.; Takahashi, T. Jane; Landowski, Claire M.

2014-01-01

Study of the petrology of Hawaiian volcanoes, in particular the historically active volcanoes on the Island of Hawai‘i, has long been of worldwide scientific interest. When Dr. Thomas A. Jaggar, Jr., established the Hawaiian Volcano Observatory (HVO) in 1912, detailed observations on basaltic activity at Kīlauea and Mauna Loa volcanoes increased dramatically. The period from 1912 to 1958 saw a gradual increase in the collection and analysis of samples from the historical eruptions of Kīlauea and Mauna Loa and development of the concepts needed to evaluate them. In a classic 1955 paper, Howard Powers introduced the concepts of magnesia variation diagrams, to display basaltic compositions, and olivine-control lines, to distinguish between possibly comagmatic and clearly distinct basaltic lineages. In particular, he and others recognized that Kīlauea and Mauna Loa basalts must have different sources.

Compositional variation within thick (>10 m) flow units of Mauna Kea Volcano cored by the Hawaii Scientific Drilling Project

Science.gov (United States)

Huang, Shichun; Vollinger, Michael J.; Frey, Frederick A.; Rhodes, J. Michael; Zhang, Qun

2016-07-01

Geochemical analyses of stratigraphic sequences of lava flows are necessary to understand how a volcano works. Typically one sample from each lava flow is collected and studied with the assumption that this sample is representative of the flow composition. This assumption may not be valid. The thickness of flows ranges from 100 m. Geochemical heterogeneity in thin flows may be created by interaction with the surficial environment whereas magmatic processes occurring during emplacement may create geochemical heterogeneities in thick flows. The Hawaii Scientific Drilling Project (HSDP) cored ∼3.3 km of basalt erupted at Mauna Kea Volcano. In order to determine geochemical heterogeneities in a flow, multiple samples from four thick (9.3-98.4 m) HSDP flow units were analyzed for major and trace elements. We found that major element abundances in three submarine flow units are controlled by the varying proportion of olivine, the primary phenocryst phase in these samples. Post-magmatic alteration of a subaerial flow led to loss of SiO2, CaO, Na2O, K2O and P2O5, and as a consequence, contents of immobile elements, such as Fe2O3 and Al2O3, increase. The mobility of SiO2 is important because Mauma Kea shield lavas divide into two groups that differ in SiO2 content. Post-magmatic mobility of SiO2 adds complexity to determining if these groups reflect differences in source or process. The most mobile elements during post-magmatic subaerial and submarine alteration are K and Rb, and Ba, Sr and U were also mobile, but their abundances are not highly correlated with K and Rb. The Ba/Th ratio has been used to document an important role for a plagioclase-rich source component for basalt from the Galapagos, Iceland and Hawaii. Although Ba/Th is anomalously high in Hawaiian basalt, variation in Ba abundance within a single flow shows that it is not a reliable indicator of a deep source component. In contrast, ratios involving elements that are typically immobile, such as La/Nb, La

Status and limiting factors of two rare plant species in dry montane communities of Hawai`i Volcanoes National Park.

Science.gov (United States)

Pratt, Linda W.; VanDeMark, Joshua R.; Euaparadorn, Melody

2012-01-01

Two rare plants native to montane dry forests and woodland communities of Hawai`i Volcanoes National Park (HAVO) were studied for more than two years to determine their stand structure, short-term mortality rates, patterns of reproductive phenology, success of fruit production, floral visitor composition, seed germination rates in the greenhouse, and survival of both natural and planted seedlings. Phyllostegia stachyoides, a shrubby Hawaiian mint (Lamiaceae) that is a species of concern, was studied within two small kīpuka at a natural population on the park’s Mauna Loa Strip, and three plantings at sites along the Mauna Loa Road were also monitored. Silene hawaiiensis, a threatened shrub species in the pink family (Caryophyllaceae), was monitored at two natural populations, one on Mauna Loa at the Three Trees Kīpuka and the second on Kīlauea Crater Rim south of Halema`uma`u. Silene hawaiiensis plantings were also made inside and outside ungulate exclosures at the park’s Kahuku Unit

An adaptive strategy for reducing Feral Cat predation on endangered hawaiian birds

Science.gov (United States)

Hess, S.C.; Banko, P.C.; Hansen, H.

2009-01-01

Despite the long history of Feral Cats Felis catus in Hawai'i, there has been little research to provide strategies to improve control programmes and reduce depredation on endangered species. Our objective Was to develop a predictive model to determine how landscape features on Mauna Kea, such as habitat, elevation, and proximity to roads, may affect the number of Feral Cats captured at each trap. We used log-link generalized linear models and QAIC c model ranking criteria to determine the effect of these factors. We found that The number of cats captured per trap Was related to effort, habitat type, and Whether traps Were located on The West or North Slope of Mauna Kea. We recommend an adaptive management strategy to minimize trapping interference by non-target Small Indian Mongoose Herpestes auropunctatus with toxicants, to focus trapping efforts in M??mane Sophora chrysophylla habitat on the West slope of Mauna Kea, and to cluster traps near others that have previously captured multiple cats.

Environmental conditions associated with lesions in introduced free-ranging sheep in Hawai‘i

Science.gov (United States)

Powers, Jenny G.; Duncan, Colleen G.; Spraker, Terry R.; Schuler, Bridget A.; Hess, Steven C.; Faford, Jonathan K.J.; Sin, Hans

2014-01-01

Wildlife species which have been translocated between temperate and tropical regions of the world provide unique opportunities to understand how disease processes may be affected by environmental conditions. European mouflon sheep (Ovis gmelini musimon) from the Mediterranean Islands were introduced to the Hawaiian Islands for sport hunting beginning in 1954 and were subsequently hybridized with feral domestic sheep (O. aries), which had been introduced in 1793. Three isolated mouflon populations have become established in the Hawaiian Islands but diseases in these populations have been little studied. The objective of this study was to evaluate and compare gross and histologic lesions in respiratory, renal, and hepatic systems of free-ranging sheep in two isolated volcanic environments on Hawai‘i Island. Tissue and fecal samples were collected in conjunction with population reductions during February 2011. We found gross or histologic evidence of lungworm infection in 44/49 sheep from Mauna Loa which were exposed to gaseous emissions from Kīlauea Volcano. In contrast, only 7/50 sheep from Mauna Kea had lesions consistent with lungworm, but Mauna Kea sheep had significantly more upper respiratory tract inflammation and hyperplasia consistent with chronic antigenic stimulation, possibly associated with exposure to fine airborne particulates during extended drought conditions. We hypothesize that gasses from Kīlauea Volcano contributed to severity of respiratory disease principally associated with chronic lungworm infections at Mauna Loa; however, there were numerous other potentially confounding environmental factors and interactions that merit further investigation.

Seismic instrumentation plan for the Hawaiian Volcano Observatory

Science.gov (United States)

Thelen, Weston A.

2014-01-01

The seismic network operated by the U.S. Geological Survey’s Hawaiian Volcano Observatory (HVO) is the main source of authoritative data for reporting earthquakes in the State of Hawaii, including those that occur on the State’s six active volcanoes (Kīlauea, Mauna Loa, Hualālai, Mauna Kea, Haleakalā, Lō‘ihi). Of these volcanoes, Kīlauea and Mauna Loa are considered “very high threat” in a report on the rationale for a National Volcanic Early Warning System (NVEWS) (Ewert and others, 2005). This seismic instrumentation plan assesses the current state of HVO’s seismic network with respect to the State’s active volcanoes and calculates the number of stations that are needed to upgrade the current network to provide a seismic early warning capability for forecasting volcanic activity. Further, the report provides proposed priorities for upgrading the seismic network and a cost assessment for both the installation costs and maintenance costs of the improved network that are required to fully realize the potential of the early warning system.

Dip in the atmospheric CO2 level during the mid-1960's

International Nuclear Information System (INIS)

Bacastow, R.

1979-01-01

Removal of the southern oscillation effect from the CO 2 records at Mauna Loa, Hawaii, and the South Pole reveals corresponding decreases following the Agung eruption in 1963. The period of the decreases roughly corresponds to the period of reduced solar transmittance, as measured at Mauna Loa. It is suggested that the decrease in CO 2 level is due to reduced sea surface temperatures, for which there is some direct evidence. The temperature anomaly required to produce the CO 2 level dip is calculated on the basis of several simple models and found to be close to that observed

Preparation of selective molybdenum concentrate from collective coppermolybdenum concentrate

Directory of Open Access Journals (Sweden)

N. Tusupbaev

2016-06-01

Full Text Available The paper considers possibilities of selective separation of the concentrate of copper and molybdenum from a collective copper-molybdenum concentrate of Aktogay deposit using regrinding and conventional flotation reagents. In the case of conventional flotoreagents, the content of molybdenum in a molybdenum concentrate was 8.0% at extraction effectiveness 83.12%. At 27.96% extraction degree of copper, it’s content in the concentrate equaled to 21.3%. After regrinding, molybdenum content in the concentrate was 24.0% at the extraction effectiveness 59.63%, and copper content in the concentrate was 21.9% at the recovery of 61.23%. Thus, the regrinding of a collective copper-molybdenum concentrate resulted in an increase in the content of molybdenum in molybdenum concentrate by 16%, and the copper concentration increased by 0.6%.

Concentrator Photovoltaics

CERN Document Server

Luque, Antonio L

2007-01-01

Photovoltaic solar-energy conversion is one of the most promising technologies for generating renewable energy, and conversion of concentrated sunlight can lead to reduced cost for solar electricity. In fact, photovoltaic conversion of concentrated sunlight insures an efficient and cost-effective sustainable power resource. This book gives an overview of all components, e.g. cells, concentrators, modules and systems, for systems of concentrator photovoltaics. The authors report on significant results related to design, technology, and applications, and also cover the fundamental physics and market considerations. Specific contributions include: theory and practice of sunlight concentrators; an overview of concentrator PV activities; a description of concentrator solar cells; design and technology of modules and systems; manufacturing aspects; and a market study.

The 40Ar/39Ar and K/Ar dating of lavas from the Hilo 1-km core hole, Hawaii Scientific Drilling Project

Science.gov (United States)

Sharp, W.D.; Turrin, B.D.; Renne, P.R.; Lanphere, M.A.

1996-01-01

Mauna Kea lava flows cored in the HilIo hole range in age from <200 ka to about 400 ka based on 40Ar/39Ar incremental heating and K-Ar analyses of 16 groundmass samples and one coexisting plagioclase. The lavas, all subaerially deposited, include a lower section consisting only of tholeiitic basalts and an upper section of interbedded alkalic, transitional tholeiitic, and tholeiitic basalts. The lower section has yielded predominantly complex, discordant 40Ar/39Ar age spectra that result from mobility of 40Ar and perhaps K, the presence of excess 40Ar, and redistribution of 39Ar by recoil. Comparison of K-Ar ages with 40Ar/39Ar integrated ages indicates that some of these samples have also lost 39Ar. Nevertheless, two plateau ages of 391 ?? 40 and 400 ?? 26 ka from deep in the hole, combined with data from the upper section, show that the tholeiitic section accumulated at an average rate of about 7 to 8 m/kyr and has an mean recurrence interval of 0.5 kyr/flow unit. Samples from the upper section yield relatively precise 40Ar/39Ar plateau and isotope correlation ages of 326 ?? 23, 241 ?? 5, 232 ?? 4, and 199 ?? 9 ka for depths of -415.7 m to -299.2 m. Within their uncertainty, these ages define a linear relationship with depth, with an average accumulation rate of 0.9 m/kyr and an average recurrence interval of 4.8 kyr/flow unit. The top of the Mauna Kea sequence at -280 m must be older than the plateau age of 132 ?? 32 ka, obtained for the basal Mauna Loa flow in the corehole. The upward decrease in lava accumulation rate is a consequence of the decreasing magma supply available to Mauna Kea as it rode the Pacific plate away from its magma source, the Hawaiian mantle plume. The age-depth relation in the core hole may be used to test and refine models that relate the growth of Mauna Kea to the thermal and compositional structure of the mantle plume.

Iridium emissions from Hawaiian volcanoes

International Nuclear Information System (INIS)

Finnegan, D.L.; Zoller, W.H.; Miller, T.M.

1988-01-01

Particle and gas samples were collected at Mauna Loa volcano during and after its eruption in March and April, 1984 and at Kilauea volcano in 1983, 1984, and 1985 during various phases of its ongoing activity. In the last two Kilauea sampling missions, samples were collected during eruptive activity. The samples were collected using a filterpack system consisting of a Teflon particle filter followed by a series of 4 base-treated Whatman filters. The samples were analyzed by INAA for over 40 elements. As previously reported in the literature, Ir was first detected on particle filters at the Mauna Loa Observatory and later from non-erupting high temperature vents at Kilauea. Since that time Ir was found in samples collected at Kilauea and Mauna Loa during fountaining activity as well as after eruptive activity. Enrichment factors for Ir in the volcanic fumes range from 10,000 to 100,000 relative to BHVO. Charcoal impregnated filters following a particle filter were collected to see if a significant amount of the Ir was in the gas phase during sample collection. Iridium was found on charcoal filters collected close to the vent, no Ir was found on the charcoal filters. This indicates that all of the Ir is in particulate form very soon after its release. Ratios of Ir to F and Cl were calculated for the samples from Mauna Loa and Kilauea collected during fountaining activity. The implications for the KT Ir anomaly are still unclear though as Ir was not found at volcanoes other than those at Hawaii. Further investigations are needed at other volcanoes to ascertain if basaltic volcanoes other than hot spots have Ir enrichments in their fumes

Iridium emissions from Hawaiian volcanoes

Science.gov (United States)

Finnegan, D. L.; Zoller, W. H.; Miller, T. M.

1988-01-01

Particle and gas samples were collected at Mauna Loa volcano during and after its eruption in March and April, 1984 and at Kilauea volcano in 1983, 1984, and 1985 during various phases of its ongoing activity. In the last two Kilauea sampling missions, samples were collected during eruptive activity. The samples were collected using a filterpack system consisting of a Teflon particle filter followed by a series of 4 base-treated Whatman filters. The samples were analyzed by INAA for over 40 elements. As previously reported in the literature, Ir was first detected on particle filters at the Mauna Loa Observatory and later from non-erupting high temperature vents at Kilauea. Since that time Ir was found in samples collected at Kilauea and Mauna Loa during fountaining activity as well as after eruptive activity. Enrichment factors for Ir in the volcanic fumes range from 10,000 to 100,000 relative to BHVO. Charcoal impregnated filters following a particle filter were collected to see if a significant amount of the Ir was in the gas phase during sample collection. Iridium was found on charcoal filters collected close to the vent, no Ir was found on the charcoal filters. This indicates that all of the Ir is in particulate form very soon after its release. Ratios of Ir to F and Cl were calculated for the samples from Mauna Loa and Kilauea collected during fountaining activity. The implications for the KT Ir anomaly are still unclear though as Ir was not found at volcanoes other than those at Hawaii. Further investigations are needed at other volcanoes to ascertain if basaltic volcanoes other than hot spots have Ir enrichments in their fumes.

Elliptical concentrators.

Science.gov (United States)

Garcia-Botella, Angel; Fernandez-Balbuena, Antonio Alvarez; Bernabeu, Eusebio

2006-10-10

Nonimaging optics is a field devoted to the design of optical components for applications such as solar concentration or illumination. In this field, many different techniques have been used to produce optical devices, including the use of reflective and refractive components or inverse engineering techniques. However, many of these optical components are based on translational symmetries, rotational symmetries, or free-form surfaces. We study a new family of nonimaging concentrators called elliptical concentrators. This new family of concentrators provides new capabilities and can have different configurations, either homofocal or nonhomofocal. Translational and rotational concentrators can be considered as particular cases of elliptical concentrators.

Concentrated Ownership

DEFF Research Database (Denmark)

Rose, Caspar

2014-01-01

This entry summarizes the main theoretical contributions and empirical findings in relation to concentrated ownership from a law and economics perspective. The various forms of concentrated ownership are described as well as analyzed from the perspective of the legal protection of investors......, especially minority shareholders. Concentrated ownership is associated with benefits and costs. Concentrated ownership may reduce agency costs by increased monitoring of top management. However, concentrated ownership may also provide dominating owners with private benefits of control....

Pushing concentration of stationary solar concentrators to the limit.

Science.gov (United States)

Winston, Roland; Zhang, Weiya

2010-04-26

We give the theoretical limit of concentration allowed by nonimaging optics for stationary solar concentrators after reviewing sun- earth geometry in direction cosine space. We then discuss the design principles that we follow to approach the maximum concentration along with examples including a hollow CPC trough, a dielectric CPC trough, and a 3D dielectric stationary solar concentrator which concentrates sun light four times (4x), eight hours per day year around.

Design and Characterization of the 4STAR Sun-Sky Spectrometer with Results from 4- Way Intercomparison of 4STAR, AATS-14, Prede, and Cimel Photometers at Mauna Loa Observatory.

Science.gov (United States)

Flynn, C. J.; Dunagan, S. E.; Johnson, R. R.; Schmid, B.; Shinozuka, Y.; Ramachandran, S.; Livingston, J. M.; Russell, P. B.; Redemann, J.; Tran, A. K.; Holben, B. N.

2008-12-01

including field of view (FOV) scans, repeatability testing of the fiber optic coupler, calibration of diffuse sky radiance with integrating sphere, and calibration of solar irradiance via Langley retrievals. Recent results from an intercomparison on Mauna Loa Observatory involving 4STAR, AATS-14, AERONET Cimel sun-sky photometers, and a Prede sun-sky photometer will be presented.

A high-resolution Fourier Transform Spectrometer for planetary spectroscopy

Science.gov (United States)

Cruikshank, D. P.; Sinton, W. M.

1973-01-01

The employment of a high-resolution Fourier Transform Spectrometer (FTS) is described for planetary and other astronomical spectroscopy in conjunction with the 88-inch telescope at Mauna Kea Observatory. The FTS system is designed for a broad range of uses, including double-beam laboratory spectroscopy, infrared gas chromatography, and nuclear magnetic resonance spectroscopy. The data system is well-suited to astronomical applications because of its great speed in acquiring and transforming data, and because of the enormous storage capability of the magnetic tape unit supplied with the system. The basic instrument is outlined 2nd some of the initial results from the first attempted use on the Mauna Kea 88-inch telescope are reported.

Hawaii: a picture window on the Universe

International Nuclear Information System (INIS)

Anderson, I.; Redfern, M.

1987-01-01

The paper concerns the telescopes and associated studies of the astronomical observatory situated on Mauna Kea, Big Island, Hawaii. Mauna Kea is the home for ten telescopes, one of which is the United Kingdom Infrared Telescope used to look at the birth of the stars. The two newest telescopes - the Clerk Maxwell Telescope and the Caltech High Dish will study the birth in even more detail using submillimetre waves. Three more telescopes are planned - the Keck ten-metre telescope is due for completion in 1990, followed by the 7.5 metre Japenese National Large Telescope and then the 15-metre National New Technology Telescope. A brief description of the latter five telescopes is given. (U.K.)

Concentration risk

Directory of Open Access Journals (Sweden)

Matić Vesna

2016-01-01

Full Text Available Concentration risk has been gaining a special dimension in the contemporary financial and economic environment. Financial institutions are exposed to this risk mainly in the field of lending, mostly through their credit activities and concentration of credit portfolios. This refers to the concentration of different exposures within a single risk category (credit risk, market risk, operational risk, liquidity risk.

Ultra flat ideal concentrators of high concentration

Energy Technology Data Exchange (ETDEWEB)

Chaves, Julio [IST, Physics Dept., Lisboa (Portugal); INETI-DER, Lisboa (Portugal); Collares-Pereira, Manuel [INETI-DER, Lisboa (Portugal)

2000-07-01

A new method for the design of nonimaging devices is presented. Its application to the design of ultra flat compact concentrators is analysed. These new concentrators are based on a combination of two stages: the first one is composed of a large number of small structures placed side by side and the second one is a very compact single device concentrating the radiation to the limit. These devices are ideal for 2D. These compact designs are much more compact than the traditional ones like lens-mirror combinations or parabolic primaries with nonimaging secondaries. Besides, they can be designed for any acceptance angle, while the traditional ones are limited to small acceptance angles. (Author)

Fine-particle sodium tracer for long-range transport of the Kuwaiti oil-fire smoke

Energy Technology Data Exchange (ETDEWEB)

Lowenthal, D.H.; Borys, R.D.; Rogers, C.F.; Chow, J.C.; Stevens, R.K.

1993-04-23

Evidence for long-range transport of the Kuwaiti oil-fire smoke during the months following the Persian Gulf War has been more or less indirect. However, more-recent data on the aerosol chemistry of Kuwaiti oil-fire plumes provides a direct link between those fires and aerosols collected at the Mauna Loa Observatory (MLO) during the late spring and summer of 1991. By itself, temporal covariation of fine-particle concentrations of elemental carbon, sulfur, and the noncrustal V/Zn ratio in MLO aerosols suggested a link to large-scale oil-combustion sources, but not necessarily to Kuwait. However, high concentrations of fine-particle (0.1-1.0 microm diameter) NaCl were observed in the 'white' oil-fire plumes over Kuwait during the summer of 1991. In the absence of other demonstratable sources of fine-particle Na, these relationships provide a direct link between the Kuwaiti oil-fires and aerosol composition observed at MLO. (Copyright (c) 1993 American Geophysical Union.)

Infrared Solar Spectroscopic Measurements of Free Tropospheric CO, C2H6, and HCN above Mauna Loa, Hawaii: Seasonal Variations and Evidence for Enhanced Emissions from the Southeast Asian Tropical Fires of 1997-1998

Science.gov (United States)

Rinsland, C. P.; Goldman, A.; Murcray, F. J.; Stephen, T. M.; Pougatchev, N. S.; Fishman, J.; David, S. J.; Blatherwick, R. D.; Novelli, P. C.; Jones, N. B.

1999-01-01

High spectral resolution (0.003 per cm) infrared solar absorption measurements of CO, C2H6, and HCN have been recorded at the Network for the Detection of Stratospheric Change station on Mauna Loa, Hawaii, (19.5N, 155.6W, altitude 3.4 km). The observations were obtained on over 250 days between August 1995 and February 1998. Column measurements are reported for the 3.4-16 km altitude region, which corresponds approximately to the free troposphere above the station. Average CO mixing ratios computed for this layer have been compared with flask sampling CO measurements obtained in situ at the station during the same time period. Both show asymmetrical seasonal cycles superimposed on significant variability. The first 2 years of observations exhibit a broad January-April maximum and a sharper CO minimum during late summer. The C2H6 and CO 3.4-16 km columns were highly correlated throughout the observing period with the C2H6/CO slope intermediate between higher and lower values derived from similar infrared spectroscopic measurements at 32'N and 45'S latitude, respectively. Variable enhancements in CO, C2H6, and particularly HCN were observed beginning in about September 1997. The maximum HCN free tropospheric monthly mean column observed in November 1997 corresponds to an average 3.4-16 km mixing ratio of 0.7 ppbv (1 ppbv = 10(exp -9) per unit volume), more than a factor of 3 above the background level. The HCN enhancements continued through the end of the observational series. Back-trajectory calculations suggest that the emissions originated at low northern latitudes in southeast Asia. Surface CO mixing ratios and the C2H6 tropospheric columns measured during the same time also showed anomalous autumn 1997 maxima. The intense and widespread tropical wild fires that burned during the strong El Nino warm phase of 1997- 1998 are the likely source of the elevated emission products.

Maximum Permissible Concentrations and Negligible Concentrations for pesticides

NARCIS (Netherlands)

Crommentuijn T; Kalf DF; Polder MD; Posthumus R; Plassche EJ van de; CSR

1997-01-01

Maximum Permissible Concentrations (MPCs) and Negligible Concentrations (NCs) derived for a series of pesticides are presented in this report. These MPCs and NCs are used by the Ministry of Housing, Spatial Planning and the Environment (VROM) to set Environmental Quality Objectives. For some of the

Experimental characterization of a concentrating photovoltaic system varying the light concentration

International Nuclear Information System (INIS)

Renno, C.; Petito, F.; Landi, G.; Neitzert, H.C.

2017-01-01

Highlights: • Experimental characterization of a concentrating photovoltaic system. • Analysis of the point-focus concentrating system performances. • Photovoltaic system parameters as function of the concentration factor. - Abstract: The concentrating photovoltaic system represents one of the most promising solar technologies because it allows a more efficient energy conversion. When a CPV system is designed, the main parameter which has to be considered is the concentration factor that affects both the system energy performances and its configuration. An experimental characterization of a CPV system previously realized at the University of Salerno, is presented in this paper considering several aspects related to the optical configuration, the concentration factor and the solar cell used. In particular, the parameters of an Indium Gallium Phosphide/Gallium Arsenide/Germanium triple-junction solar cell are investigated as function of the concentration factor determined by means of an experimental procedure that uses different optical configurations. The maximum concentration factor reached by the CPV system is 310 suns. The cell parameters dependence on the concentration is reported together with an electroluminescence analysis of the Indium Gallium Phosphide/Gallium Arsenide/Germanium cell. A monitoring of the electrical power provided by the system during its working is also presented corresponding to different direct irradiance values. A mean power of 2.95 W with an average efficiency of 32.8% is obtained referring to a mean irradiance of 930 W/m"2; lower values are obtained when the irradiance is highly fluctuating. The concentrating photovoltaic system electric energy output is estimated considering different concentration levels; the maximal obtained value is 23.5 W h on a sunny day at 310×. Finally, the temperature of the triple-junction solar cell is evaluated for different months in order to evaluate the potential annual thermal energy production

Studies on influence of environmental factors on concentration on concentration of radionuclides

International Nuclear Information System (INIS)

Anon.

1974-01-01

Environmental factors which seemed to influence the concentration of radionuclides to marine organisms including illumination, water temperature, coexisting stable elements, salt concentration, suspended matters in sea water and residue were studied. The influence of illumination was examined by algae using 137 Cs, 60 Co, 85 Sr, and 106 Ru as tracers, within 24 hours of illumination. The concentration of 137 Cs and 60 Co revealed remarkable increase of uptake in accordance with increasing illumination intensity, and 24 hours illumination showed 2 times concentration of that by 4 hours'. 85 Sr and 106 Ru showed no effect of illumination, and suggested their concentration was depending on adsorption to the surface. As for water temperature, the concentration factor of 65 Zn, 137 Cs obtained from fishes and shells by 22 0 C breeding was 2 times of that by 12 0 C breeding. Concerning the influence of coexisting stable elements, fishes and shells were examined by 54 Mn, 60 Co, and 65 Zn as tracers. When the stable elements concentration in sea water became 10 times the normal, concentration factor depending on adsorption and metabolism became respective one tenth and one second of the normal value. The influence of salt concentration was examined using 85 Sr, 65 Zn, and 137 Cs, and revealed that 28 to 40 per cent changes of salt level gave slight influence on concentration factor. In order to study the influence of suspended matters and quality of residue, 3 kinds of 106 Ru complex species were added. Concentration factor of Hijiki (Hijikia fusiforme) showed no remarkable difference between breeding in filtrated and non-filtrated sea water. However, clams living in the sand should be taken care of the concentration by the residue in the sea bottom. (Kanao, N.)

In Situ Resource Utilization (ISRU) on the Moon: Moessbauer Spectroscopy as a Process Monitor for Oxygen Production. Results from a Field Test on Mauna Kea Volcano, Hawaii

Science.gov (United States)

Morris, R.V.; Schroder, C.; Graff, T.G.; Sanders, G.B.; Lee, K.A.; Simon, T.M.; Larson, W.E.; Quinn, J.W.; Clark, L.D.; Caruso, J.J.

2009-01-01

Essential consumables like oxygen must to be produced from materials on the lunar surface to enable a sustained, long-term presence of humans on the Moon. The Outpost Precursor for ISRU and Modular Architecture (OPTIMA) field test on Mauna Kea, Hawaii, facilitated by the Pacific International Space Center for Exploration Systems (PISCES) of the University of Hawaii at Hilo, was designed to test the implementation of three hardware concepts to extract oxygen from the lunar regolith: Precursor ISRU Lunar Oxygen Testbed (PILOT) developed by Lockheed Martin in Littleton, CO; Regolith & Environmental Science and Oxygen & Lunar Volatiles Extraction (RESOLVE) developed at the NASA Kennedy Space Center in Cape Canaveral, FL; and ROxygen developed at the NASA Johnson Space Center in Houston, TX. The three concepts differ in design, but all rely on the same general principle: hydrogen reduction of metal cations (primarily Fe2+) bonded to oxygen to metal (e.g., Fe0) with the production of water. The hydrogen source is residual hydrogen in the fuel tanks of lunar landers. Electrolysis of the water produces oxygen and hydrogen (which is recycled). We used the miniaturized M ssbauer spectrometer MIMOS II to quantify the yield of this process on the basis of the quantity of Fe0 produced. Iron M ssbauer spectroscopy identifies iron-bearing phases, determines iron oxidation states, and quantifies the distribution of iron between mineral phases and oxidation states. The oxygen yield can be calculated by quantitative measurements of the distribution of Fe among oxidation states in the regolith before and after hydrogen reduction. A M ssbauer spectrometer can also be used as a prospecting tool to select the optimum feedstock for the oxygen production plants (e.g., high total Fe content and easily reduced phases). As a demonstration, a MIMOS II backscatter spectrometer (SPESI, Germany) was mounted on the Cratos rover (NASA Glenn Research Center in Cleveland, OH), which is one of

Horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications.

Science.gov (United States)

Ma, Hongcai; Wu, Lin

2015-07-10

We present the design of a horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications. This solar concentrator consists of an array of telecentric primary concentrators, a horizontally staggered lightguide layer, and a vertically tapered lightguide layer. The primary concentrator is realized by two plano-aspheric lenses with lateral movement and maintains a high F-number over an angle range of ±23.5°. The results of the simulations show that the solar concentrator achieves a high concentration ratio of 500× with ±0.5° of acceptance angle by a single-axis tracker and dual lateral translation stages.

Experimental investigations into low concentrating line axis solar concentrators for CPV applications

OpenAIRE

Singh, H; Sabry, M; Redpath, DAG

2016-01-01

Solar photovoltaic conversion systems with integrated, low concentration ratio, non-imaging reflective concentrators, could be on south facing building roofs used to generate power at a lower cost than currently available proprietary systems. The experimental investigation presented by this research provides information on the optical and energy conversion characteristics of two geometrically equivalent non-imaging concentrators; a compound parabolic concentrator and a V-trough reflector. The...

Hawaii's Annual Journey Through the Universe Program

Science.gov (United States)

Harvey, J.; Daou, D.; Day, B.; Slater, T. F.; Slater, S. J.

2012-08-01

Hawaii's annual Journey through the Universe program is a flagship Gemini public education and outreach event that engages the public, teachers, astronomers, engineers, thousands of local students and staff from all of the Mauna Kea Observatories. The program inspires, educates, and engages teachers, students, and their families as well as the community. From February 10-18, 2011, fifty-one astronomy educators from observatories on Mauna Kea and across the world visited over 6,500 students in 310 classrooms at 18 schools. Two family science events were held for over 2,500 people at the 'Imiloa Astronomy Education Center and the University of Hawaii at Hilo. The local Chamber of Commerce(s) held an appreciation celebration for the astronomers attended by over 170 members from the local government and business community. Now going into its eighth year in Hawaii, the 2012 Journey Through the Universe program will continue working with the observatories on Mauna Kea and with the NASA Lunar Science Institute (NLSI). As a new partner in our Journey program, NLSI will join the Journey team (Janice Harvey, Gemini Observatory, Journey Team Leader) and give an overview of the successes and future developments of this remarkable program and its growth. The future of America rests on our ability to train the next generation of scientists and engineers. Science education is key and Journey through the Universe opens the doors of scientific discovery for our students. www.gemini.edu/journey

Vaginal oxytetracycline concentrations.

Science.gov (United States)

Thin, R N; Al Rawi, Z H; Simmons, P D; Treharne, J; Tabaqchali, S

1979-01-01

Although tetracycline preparations are widely used in departments of genitourinary medicine, or sexually transmitted diseases clinics, little is known of the concentrations of these preparations in genital secretions. For this reason a microbiological method was used for estimating oxytetracycline concentrations in vaginal secretions. These concentrations varied from 0.6 to 6.5 microgram/ml in 19 women who had had sexual contact with a man with non-specific urethritis and who were taking oxytetracycline dihydrate 250 mg four times daily. They were well in excess of the minimum inhibitory concentration of oxytetracycline (0.2 microgram/ml) for the strains of Chlamydia trachomatis isolated from the patients with positive culture results. Thus, oxytetracycline 250 mg four times daily appears to be a satisfactory regimen for the treatment of chlamydial genital infection in women. PMID:509190

Underscreening in concentrated electrolytes.

Science.gov (United States)

Lee, Alpha A; Perez-Martinez, Carla S; Smith, Alexander M; Perkin, Susan

2017-07-01

Screening of a surface charge by an electrolyte and the resulting interaction energy between charged objects is of fundamental importance in scenarios from bio-molecular interactions to energy storage. The conventional wisdom is that the interaction energy decays exponentially with object separation and the decay length is a decreasing function of ion concentration; the interaction is thus negligible in a concentrated electrolyte. Contrary to this conventional wisdom, we have shown by surface force measurements that the decay length is an increasing function of ion concentration and Bjerrum length for concentrated electrolytes. In this paper we report surface force measurements to test directly the scaling of the screening length with Bjerrum length. Furthermore, we identify a relationship between the concentration dependence of this screening length and empirical measurements of activity coefficient and differential capacitance. The dependence of the screening length on the ion concentration and the Bjerrum length can be explained by a simple scaling conjecture based on the physical intuition that solvent molecules, rather than ions, are charge carriers in a concentrated electrolyte.

L' AND M' Photometry Of Ultracool Dwarfs

National Research Council Canada - National Science Library

Marley, M

2004-01-01

We have compiled L' (3.4-4.1 microns) and M' (4.6-4.8 microns) photometry of 63 single and binary M, L, and T dwarfs obtained at the United Kingdom Infrared Telescope using the Mauna Kea Observatory filter set...

Performance investigation of a concentrating photovoltaic/thermal system with transmissive Fresnel solar concentrator

International Nuclear Information System (INIS)

Feng, Chaoqing; Zheng, Hongfei; Wang, Rui; Ma, Xinglong

2016-01-01

Highlights: • A common design method of a cycloidal transmissive Fresnel solar concentrator was presented. • The gallium arsenide high concentrated solar was used as the receiver. • High efficiency of electric generating could be achieved at noon. • Fresnel solar concentrator was studied and compared in hazy weather and clear weather. - Abstract: A design method of a cycloidal transmissive Fresnel solar concentrator which can provide a certain width focal line was presented in this study. Based on the optical principle of refraction, the dimensions of each wedge-shaped element of Fresnel lens are calculated. An optical simulation has been done to obtain the optical efficiency of the concentrator for different tracking error and axial incidence angle. It has been found that about 80% of the incident sunlight can still be gathered by the absorber when the tracking error is within 0.7°. When the axial angle of incidence is within 10°, it almost has no influence to the receiving rate. The concentrating photovoltaic/thermal system with transmissive Fresnel solar concentrator has been designed in this paper. Take the gallium arsenide high concentrated battery as the receiver, experimental research about cylindrical Fresnel concentrating photovoltaic/thermal system is undertaken in the real sky. Main parameters are tested such as the temperature distribution on receiver, electric energy and thermal energy outputs of concentrating photovoltaic/thermal system, the efficiency of multipurpose utilization of electric and heat, and so on. The test results in clear weather show that maximum electric generating efficiency is about 18% at noon, the maximum heat receiving rate of cooling water is about 45%. At noon time (11:00–13:00), the total efficiency of thermal and electricity can reach more than 55%. Performance of this concentrating photovoltaic/thermal system with transmissive Fresnel solar concentrator is studied and compared in two types typical weather, hazy

Highly concentrating Fresnel lenses

International Nuclear Information System (INIS)

Kritchman, E.M.; Friesem, A.A.; Yekutieli, G.

1979-01-01

A new type of concave Fresnel lens capable of concentrating solar radiation very near the ultimate concentration limit is considered. The differential equations that describe the lens are solved to provide computed solutions which are then checked by ray tracing techniques. The performance (efficiency and concentration) of the lens is investigated and compared to that of a flat Fresnel lens, showing that the new lens is preferable for concentrating solar radiation. (author)

[Ozone concentration distribution of urban].

Science.gov (United States)

Yin, Yong-quan; Li, Chang-mei; Ma, Gui-xia; Cui, Zhao-jie

2004-11-01

The increase of ozone concentration in urban is one of the most important research topics on environmental science. With the increase of nitrogen oxides and hydrogen-carbon compounds which are exhausted from cars, the ozone concentration in urban is obviously increased on sunlight, and threat of photochemistry smog will be possible. Therefore, it is very important to monitor and study the ozone concentration distribution in urban. The frequency-distribution, diurnal variation and monthly variation of ozone concentration were studied on the campus of Shandong University during six months monitoring. The influence of solar radiation and weather conditions on ozone concentration were discussed. The frequency of ozone concentration less than 200 microg/m3 is 96.88%. The ozone concentration has an obvious diurnal variation. The ozone concentration in the afternoon is higher than in the morning and in the evening. The maximum appears in June, when it is the strong solar radiation and high air-temperature. The weather conditions also influence the ozone concentration. The ozone concentration in clear day is higher than in rainy and cloudy day.

Observed decrease in atmospheric mercury explained by global decline in anthropogenic emissions

Science.gov (United States)

Yanxu Zhang,; Daniel J. Jacob,; Hannah M. Horowitz,; Long Chen,; Helen M. Amos,; Krabbenhoft, David P.; Franz Slemr,; Vincent L. St. Louis,; Elsie M. Sunderland,

2015-01-01

Observations of elemental mercury (Hg0) at sites in North America and Europe show large decreases (∼1–2% y−1) from 1990 to present. Observations in background northern hemisphere air, including Mauna Loa Observatory (Hawaii) and CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) aircraft flights, show weaker decreases (Asia. Implementation of our inventory in a global 3D atmospheric Hg simulation [GEOS-Chem (Goddard Earth Observing System-Chemistry)] coupled to land and ocean reservoirs reproduces the observed large-scale trends in atmospheric Hg0 concentrations and in HgII wet deposition. The large trends observed in North America and Europe reflect the phase-out of Hg from commercial products as well as the cobenefit from SO2 and NOx emission controls on coal-fired utilities.

Rheology of concentrated biomass

Science.gov (United States)

J.R. Samaniuk; J. Wang; T.W. Root; C.T. Scott; D.J. Klingenberg

2011-01-01

Economic processing of lignocellulosic biomass requires handling the biomass at high solids concentration. This creates challenges because concentrated biomass behaves as a Bingham-like material with large yield stresses. Here we employ torque rheometry to measure the rheological properties of concentrated lignocellulosic biomass (corn stover). Yield stresses obtained...

Solar cell concentrating system

International Nuclear Information System (INIS)

Garg, H.P.; Sharma, V.K.; Agarwal, R.K.

1986-11-01

This study reviews fabrication techniques and testing facilities for different solar cells under concentration which have been developed and tested. It is also aimed to examine solar energy concentrators which are prospective candidates for photovoltaic concentrator systems. This may provide an impetus to the scientists working in the area of solar cell technology

Effect of Crude Protein Levels in Concentrate and Concentrate Levels in Diet on Fermentation

Directory of Open Access Journals (Sweden)

Dinh Van Dung

2014-06-01

Full Text Available The effect of concentrate mixtures with crude protein (CP levels 10%, 13%, 16%, and 19% and diets with roughage to concentrate ratios 80:20, 60:40, 40:60, and 20:80 (w/w were determined on dry matter (DM and organic matter (OM digestibility, and fermentation metabolites using an in vitro fermentation technique. In vitro fermented attributes were measured after 4, 24, and 48 h of incubation respectively. The digestibility of DM and OM, and total volatile fatty acid (VFA increased whereas pH decreased with the increased amount of concentrate in the diet (p<0.001, however CP levels of concentrate did not have any influence on these attributes. Gas production reduced with increased CP levels, while it increased with increasing concentrate levels. Ammonia nitrogen (NH3-N concentration and microbial CP production increased significantly (p<0.05 by increasing CP levels and with increasing concentrate levels in diet as well, however, no significant difference was found between 16% and 19% CP levels. Therefore, 16% CP in concentrate and increasing proportion of concentrate up to 80% in diet all had improved digestibility of DM and organic matter, and higher microbial protein production, with improved fermentation characteristics.

Free amino nitrogen concentration correlates to total yeast assimilable nitrogen concentration in apple juice.

Science.gov (United States)

Boudreau, Thomas F; Peck, Gregory M; O'Keefe, Sean F; Stewart, Amanda C

2018-01-01

Yeast assimilable nitrogen (YAN) is essential for yeast growth and metabolism during apple ( Malus x domestica Borkh.) cider fermentation. YAN concentration and composition can impact cider fermentation kinetics and the formation of volatile aroma compounds by yeast. The YAN concentration and composition of apples grown in Virginia, USA over the course of two seasons was determined through analysis of both free amino nitrogen (FAN) and ammonium ion concentration. FAN was the largest fraction of YAN, with a mean value of 51 mg N L -1 FAN compared to 9 mg N L -1 ammonium. Observed YAN values ranged from nine to 249 mg N L -1 , with a mean value of 59 mg N L -1 . Ninety-four percent of all samples analyzed in this study contained yeast to fully utilize all of the fermentable sugars. FAN concentration was correlated with total YAN concentration, but ammonium concentration was not. Likewise, there was no correlation between FAN and ammonium concentration.

International Gemini Observatory officially launched

CERN Multimedia

2002-01-01

Over 200 research, engineering, and science leaders from seven countries journeyed to the top of a remote mountain in the Chilean Andes to celebrate the inauguration the new Gemini South telescope, the complement of the Gemini North telescope already operating in Mauna Kea, Hawaii.

Design and construction of non-imaging planar concentrator for concentrator photovoltaic system

Energy Technology Data Exchange (ETDEWEB)

Chong, K.K.; Siaw, F.L.; Wong, C.W.; Wong, G.S. [Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Off Jalan Genting Kelang, Setapak, 53300 Kuala Lumpur, Wilayah Persekutuan (Malaysia)

2009-05-15

A novel configuration of solar concentrator, which is the non-imaging planar concentrator, capable of producing much more uniform sunlight and reasonably high concentration ratio, is designed and constructed. This design is envisioned to be incorporated in concentrator photovoltaic (CPV) systems. The work presented here reports on the design, optical alignment and application of the prototype, which is installed at Universiti Tunku Abdul Rahman (UTAR), Malaysia. In the architecture of the prototype, 360 flat mirrors, each with a dimension of 4.0 cm x 4.0 cm, are arranged into 24 rows and 15 columns with a total reflection area of about 5760 cm{sup 2}. In addition to that, illumination distribution for the prototype is simulated and its results are then compared with the experiment result. (author)

Optical assessment of nonimaging concentrators.

Science.gov (United States)

Timinger, A; Kribus, A; Ries, H; Smith, T; Walther, M

2000-11-01

An optical measurement method for nonimaging radiation concentrators is proposed. A Lambertian light source is placed in the exit aperture of the concentrator. Looking into the concentrator's entrance aperture from a remote position, one can photograph the transmission patterns. The patterns show the transmission of radiation through the concentrator with the full resolution of the four-dimensional phase space of geometric optics. By matching ray-tracing simulations to the measurement, one can achieve detailed and accurate information about the geometry of the concentrator. This is a remote, noncontact measurement and can be performed in situ for installed concentrators. Additional information regarding small-scale reflector waviness and surface reflectivity can also be obtained from the same measurement with additional analysis.

Photovoltaic static concentrator analysis

Science.gov (United States)

Almonacid, G.; Luque, A.; Molledo, A. G.

1984-12-01

Ray tracing is the basis of the present analysis of truncated bifacial compound parabolic concentrators filled with a dielectric substance, which are of interest in photovoltaic applications where the bifacial cells allow higher static concentrations to be achieved. Among the figures of merit for this type of concentrator, the directional intercept factor plays a major role and is defined as the ratio of the power of the collector to that at the entry aperture, in a lossless concentrator illuminated by light arriving from a given direction. A procedure for measuring outdoor, full size panels has been developed, and a correction method for avoiding the effect of unwanted diffuse radiation during the measurements is presented.

Photovoltaic solar concentrator

Science.gov (United States)

Nielson, Gregory N.; Gupta, Vipin P.; Okandan, Murat; Watts, Michael R.

2016-03-15

A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

Dependency of soil activity concentration on soil -biota concentration ratio of radionuclides for earthworm

Energy Technology Data Exchange (ETDEWEB)

Keum, Dong Kwon; Kim, Byeong Ho; Jun, In; Lim, Kwang Muk; Choi, Yong Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2012-05-15

The transfer of radionuclides to wildlife (non-human biota) is normally quantified using an equilibrium concentration ratio (CR{sub eq}), defined as the radionuclide activity concentration in the whole organism (fresh weight) divided by that in the media (dry weight for soil). The present study describes the effect of soil radionuclide activity concentration on the transfer of {sup 137}Cs, {sup 85}Sr and {sup 65}Zn to a functionally important wildlife group, annelids, using a commonly studied experimental worm (E.andrei). Time-dependent whole body concentration ratios of {sup 137}Cs, {sup 85}Sr and {sup 65}Zn for the earthworm were experimentally measured for artificially contaminated soils with three different activity concentrations for each radionuclide which were considerably higher than normal background levels. Two parameters of a first order kinetic model, the equilibrium concentration ratio (CR{sub eq}) and the effective loss rate constant (k), were estimated by comparison of experimental CR results with the model prediction

Spectral reflectance study of the Hadley-Appenine (Apollo 15) region

International Nuclear Information System (INIS)

Lucey, P.G.; Hawke, B.R.

1985-01-01

Twenty three near infrared spectra were obtained from the Mauna Kea Observatory 2.2 m telescope. Results of an analysis of near infrared spectra obtained for surface units in the Hadley-Apennine region were presented. Compositional trends from the interior to exterior of the Imbrium are discussed

Low concentrator PV optics optimization

Science.gov (United States)

Sharp, Leonard; Chang, Ben

2008-08-01

Purpose: Cost reduction is a major focus of the solar industry. Thin film technologies and concentration systems are viable ways to reducing cost, with unique strengths and weakness for both. Most of the concentrating PV work focuses on high concentration systems for reducing energy cost. Meanwhile, many believe that low concentrators provide significant cost reduction potential while addressing the mainstream PV market with a product that acts as a flat panel replacement. This paper analyzes the relative benefit of asymmetric vs. symmetric optics for low-concentrators in light of specific PV applications. Approach: Symmetric and asymmetric concentrating PV module performance is evaluated using computer simulation to determine potential value across various geographic locations and applications. The selected optic design is modeled against standard cSi flat panels and thin film to determine application fit, system level energy density and economic value. Results: While symmetric designs may seem ideal, asymmetric designs have an advantage in energy density. Both designs are assessed for aperture, optimum concentration ratio, and ideal system array configuration. Analysis of performance across climate specific effects (diffuse, direct and circumsolar) and location specific effects (sunpath) are also presented. The energy density and energy production of low concentrators provide a compelling value proposition. More significantly, the choice of optics for a low concentrating design can affect real world performance. With the goal of maximizing energy density and return on investment, this paper presents the advantages of asymmetric optic concentration and illustrates the value of this design within specific PV applications.

Using Stable Isotopes in Water Vapor to Diagnose Relationships Between Lower-Tropospheric Stability, Mixing, and Low-Cloud Cover Near the Island of Hawaii

Science.gov (United States)

Galewsky, Joseph

2018-01-01

In situ measurements of water vapor isotopic composition from Mauna Loa, Hawaii, are merged with soundings from Hilo to show an inverse relationship between the estimated inversion strength (EIS) and isotopically derived measures of lower-tropospheric mixing. Remote sensing estimates of cloud fraction, cloud liquid water path, and cloud top pressure were all found to be higher (lower) under low (high) EIS. Inverse modeling of the isotopic data corresponding to terciles of EIS conditions provide quantitative constraints on the last-saturation temperatures and mixing fractions that govern the humidity above the trade inversion. The mixing fraction of water vapor transported from the boundary layer to Mauna Loa decreases with respect to EIS at a rate of about 3% K-1, corresponding to a mixing ratio decrease of 0.6 g kg-1 K-1. A last-saturation temperature of 240 K can match all observations. This approach can be applied in other settings and may be used to test models of low-cloud climate feedbacks.

ʻŌhiʻa Lehua rainforest: born among Hawaiian volcanoes, evolved in isolation: the story of a dynamic ecosystem with relevance to forests worldwide

Science.gov (United States)

Mueller-Dombois, Dieter; Jacobi, James D.; Boehmer, Hans Juergen; Price, Jonathan P.

2013-01-01

In the early 1970s, a multidisciplinary team of forest biologists began a study of Hawaiian ecosystems under the International Biological Program (IBP). Research focus was on the intact native ecosystems in and around Hawai'i Volcanoes National Park, in particular the ʻŌhiʻa Lehua rainforest. Patches of dead ʻŌhiʻa stands had been reported from the windward slopes of Mauna Loa and Mauna Kea. Subsequent air photo analyses by a team of US and Hawai'i State foresters discovered rapidly spreading ʻŌhiʻa dieback, also called ʻŌhiʻa forest decline. A killer disease was suspected to destroy the Hawaiian rain forest in the next 15-25 years. Ecological research continued with a focus on the dynamics of the Hawaiian rainforest. This book explains what really happened and why the ʻŌhiʻa rainforest survived in tact as everyone can witness today.

Observatories and Telescopes of Modern Times

Science.gov (United States)

Leverington, David

2016-11-01

Preface; Part I. Optical Observatories: 1. Palomar Mountain Observatory; 2. The United States Optical Observatory; 3. From the Next Generation Telescope to Gemini and SOAR; 4. Competing primary mirror designs; 5. Active optics, adaptive optics and other technical innovations; 6. European Northern Observatory and Calar Alto; 7. European Southern Observatory; 8. Mauna Kea Observatory; 9. Australian optical observatories; 10. Mount Hopkins' Whipple Observatory and the MMT; 11. Apache Point Observatory; 12. Carnegie Southern Observatory (Las Campanas); 13. Mount Graham International Optical Observatory; 14. Modern optical interferometers; 15. Solar observatories; Part II. Radio Observatories: 16. Australian radio observatories; 17. Cambridge Mullard Radio Observatory; 18. Jodrell Bank; 19. Early radio observatories away from the Australian-British axis; 20. The American National Radio Astronomy Observatory; 21. Owens Valley and Mauna Kea; 22. Further North and Central American observatories; 23. Further European and Asian radio observatories; 24. ALMA and the South Pole; Name index; Optical observatory and telescope index; Radio observatory and telescope index; General index.

Platelet concentration in platelet concentrates and periodontal regeneration-unscrambling the ambiguity

Directory of Open Access Journals (Sweden)

A Suchetha

2015-01-01

Full Text Available Context: Platelet-rich-plasma (PRP and Platelet-rich-fibrin (PRF are extensively used autologous platelet concentrates in periodontal regeneration, and PRF has a better efficacy as compared to PRP. The rationale for this difference has often been attributed to the difference in the structure of the fibrin matrix. However, the effect of concentration of platelets on the regenerative potential of these concentrates is obscure. Aims: The study was conducted to evaluate and compare, clinically and radiographically, the efficacy of PRF and PRP in the treatment of periodontal endosseous defects and to assess the effect of platelet concentration on periodontal regeneration. Materials and Methods: Twenty intrabony defects were selected and divided into two groups randomly by the coin toss method. Group I received PRP and Group II subjects were treated with PRF. The platelet counts in PRP and PRF were analyzed. Clinical and radiological parameters were assessed at baseline and 3, 6, and 9 months postoperatively. Statistical Analysis: Kruskal–Wallis Chi-square test, Wilcoxon signed rank test, t-test, and Spearman's rank correlation were used for statistical analysis of data. Results: There was statistically significant improvement in all the parameters in the two groups except in relation to gingival recession. There was a statistically significant difference between the platelet count in Group I and Group II (P = 0.002. Conclusion: PRP and PRF appear to have nearly comparable effects in terms of periodontal regeneration. The concentration of platelets appears to play a paradoxical role in regeneration. The regenerative potential of platelets appears to be optimal within a limited range.

Preovulatory progesterone concentration associates significantly to follicle number and LH concentration but not to pregnancy rate

DEFF Research Database (Denmark)

Yding Andersen, Claus; Bungum, Leif; Nyboe Andersen, Anders

2011-01-01

Using data from a large prospective randomized controlled trial that evaluated the effect of recombinant LH (rLH)co-administration for ovarian stimulation, the present study assessed whether progesterone concentration on the day of human chorionic gonadotrophin (HCG) administration was associated...... with or without rLH administration from day 6 of stimulation. There was no significant association between the late-follicular-phase progesterone concentration and the clinical pregnancy rate. However, progesterone concentration was strongly associated with the number of follicles and retrieved oocytes. Late......-follicular-phase LH concentration also showed a significant positive association with progesterone concentration (P = 0.018). Administration of rLH during ovarian stimulation did not affect progesterone concentration. The present study does not support an association between progesterone concentration on the day...

Parabolic solar concentrator

Science.gov (United States)

Tecpoyotl-Torres, M.; Campos-Alvarez, J.; Tellez-Alanis, F.; Sánchez-Mondragón, J.

2006-08-01

In this work we present the basis of the solar concentrator design, which has is located at Temixco, Morelos, Mexico. For this purpose, this place is ideal due to its geographic and climatic conditions, and in addition, because it accounts with the greatest constant illumination in Mexico. For the construction of the concentrator we use a recycled parabolic plate of a telecommunications satellite dish (NEC). This plate was totally covered with Aluminum. The opening diameter is of 332 cm, the focal length is of 83 cm and the opening angle is of 90°. The geometry of the plate guaranties that the incident beams, will be collected at the focus. The mechanical treatment of the plate produces an average reflectance of 75% in the visible region of the solar spectrum, and of 92% for wavelengths up to 3μm in the infrared region. We obtain up to 2000°C of temperature concentration with this setup. The reflectance can be greatly improved, but did not consider it as typical practical use. The energy obtained can be applied to conditions that require of those high calorific energies. In order to optimize the operation of the concentrator we use a control circuit designed to track the apparent sun position.

Using atmospheric CO2 data to assess a simplified carbon-climate simulation for the 20th century

International Nuclear Information System (INIS)

Law, Rachel M.; Kowalczyk, Eva A.; Wangs, Ying-Ping

2006-01-01

The CSIRO biosphere model has been coupled to an atmosphere model and a simulation has been performed for the 20th century. Both biosphere and atmosphere are forced with global CO 2 concentration and the atmosphere is also forced with prescribed sea surface temperatures. The simulation follows the C4MIP Phase 1 protocol. We assess the model simulation using atmospheric CO 2 data. Mauna Loa growth rate is well simulated from 1980 but overestimated before that time. The interannual variations in growth rate are reasonably reproduced. Seasonal cycles are underestimated in northern mid-latitudes and are out of phase in the southern hemisphere. The north-south gradient of annual mean CO 2 is substantially overestimated due to a northern hemisphere net biosphere source and a southern tropical sink. Diurnal cycles at three northern hemisphere locations are larger than observed in many months, most likely due to larger respiration than observed

Leaching of copper concentrates using NaCl and soluble copper contributed by the own concentrate

International Nuclear Information System (INIS)

Herrero, O.; Bernal, N.; Quiroz, R.; Fuentes, G.; Vinals, J.

2005-01-01

Leaching of copper concentrates using cupric chloro complexes, generated in situ by the reaction between Cu(II), aported by the soluble copper content of the concentrate, and sodium chloride in acid media was studied. The concentrate samples were obtained from mineral processing plants from Antofagasta, Chile. Chemical and mineralogical characterization from original concentrates was made. Typical variable such as a chloride concentration, soluble copper concentration, leaching time, solid percentage and temperature were studied. DRX and EDS analyzed some of the residues. the experimental results indicated that it is possible to obtain solutions having high copper content (15 to 35 g/L) and 2 to 5 g/L free acid in order to submit this solution directly to a solvent extraction stage. The leaching tests use common reactive and low cost such as sodium chloride and sulfuric acid. (Author) 16 refs

Concentrating photovoltaic solar panel

Science.gov (United States)

Cashion, Steven A; Bowser, Michael R; Farrelly, Mark B; Hines, Braden E; Holmes, Howard C; Johnson, Jr., Richard L; Russell, Richard J; Turk, Michael F

2014-04-15

The present invention relates to photovoltaic power systems, photovoltaic concentrator modules, and related methods. In particular, the present invention features concentrator modules having interior points of attachment for an articulating mechanism and/or an articulating mechanism that has a unique arrangement of chassis members so as to isolate bending, etc. from being transferred among the chassis members. The present invention also features adjustable solar panel mounting features and/or mounting features with two or more degrees of freedom. The present invention also features a mechanical fastener for secondary optics in a concentrator module.

Thermodynamic efficiency of nonimaging concentrators

Science.gov (United States)

Shatz, Narkis; Bortz, John; Winston, Roland

2009-08-01

The purpose of a nonimaging concentrator is to transfer maximal flux from the phase space of a source to that of a target. A concentrator's performance can be expressed relative to a thermodynamic reference. We discuss consequences of Fermat's principle of geometrical optics. We review étendue dilution and optical loss mechanisms associated with nonimaging concentrators, especially for the photovoltaic (PV) role. We introduce the concept of optical thermodynamic efficiency which is a performance metric combining the first and second laws of thermodynamics. The optical thermodynamic efficiency is a comprehensive metric that takes into account all loss mechanisms associated with transferring flux from the source to the target phase space, which may include losses due to inadequate design, non-ideal materials, fabrication errors, and less than maximal concentration. As such, this metric is a gold standard for evaluating the performance of nonimaging concentrators. Examples are provided to illustrate the use of this new metric. In particular we discuss concentrating PV systems for solar power applications.

Estimation of surface area concentration of workplace incidental nanoparticles based on number and mass concentrations

Science.gov (United States)

Park, J. Y.; Ramachandran, G.; Raynor, P. C.; Kim, S. W.

2011-10-01

Surface area was estimated by three different methods using number and/or mass concentrations obtained from either two or three instruments that are commonly used in the field. The estimated surface area concentrations were compared with reference surface area concentrations (SAREF) calculated from the particle size distributions obtained from a scanning mobility particle sizer and an optical particle counter (OPC). The first estimation method (SAPSD) used particle size distribution measured by a condensation particle counter (CPC) and an OPC. The second method (SAINV1) used an inversion routine based on PM1.0, PM2.5, and number concentrations to reconstruct assumed lognormal size distributions by minimizing the difference between measurements and calculated values. The third method (SAINV2) utilized a simpler inversion method that used PM1.0 and number concentrations to construct a lognormal size distribution with an assumed value of geometric standard deviation. All estimated surface area concentrations were calculated from the reconstructed size distributions. These methods were evaluated using particle measurements obtained in a restaurant, an aluminum die-casting factory, and a diesel engine laboratory. SAPSD was 0.7-1.8 times higher and SAINV1 and SAINV2 were 2.2-8 times higher than SAREF in the restaurant and diesel engine laboratory. In the die casting facility, all estimated surface area concentrations were lower than SAREF. However, the estimated surface area concentration using all three methods had qualitatively similar exposure trends and rankings to those using SAREF within a workplace. This study suggests that surface area concentration estimation based on particle size distribution (SAPSD) is a more accurate and convenient method to estimate surface area concentrations than estimation methods using inversion routines and may be feasible to use for classifying exposure groups and identifying exposure trends.

Estimation of surface area concentration of workplace incidental nanoparticles based on number and mass concentrations

International Nuclear Information System (INIS)

Park, J. Y.; Ramachandran, G.; Raynor, P. C.; Kim, S. W.

2011-01-01

Surface area was estimated by three different methods using number and/or mass concentrations obtained from either two or three instruments that are commonly used in the field. The estimated surface area concentrations were compared with reference surface area concentrations (SA REF ) calculated from the particle size distributions obtained from a scanning mobility particle sizer and an optical particle counter (OPC). The first estimation method (SA PSD ) used particle size distribution measured by a condensation particle counter (CPC) and an OPC. The second method (SA INV1 ) used an inversion routine based on PM1.0, PM2.5, and number concentrations to reconstruct assumed lognormal size distributions by minimizing the difference between measurements and calculated values. The third method (SA INV2 ) utilized a simpler inversion method that used PM1.0 and number concentrations to construct a lognormal size distribution with an assumed value of geometric standard deviation. All estimated surface area concentrations were calculated from the reconstructed size distributions. These methods were evaluated using particle measurements obtained in a restaurant, an aluminum die-casting factory, and a diesel engine laboratory. SA PSD was 0.7–1.8 times higher and SA INV1 and SA INV2 were 2.2–8 times higher than SA REF in the restaurant and diesel engine laboratory. In the die casting facility, all estimated surface area concentrations were lower than SA REF . However, the estimated surface area concentration using all three methods had qualitatively similar exposure trends and rankings to those using SA REF within a workplace. This study suggests that surface area concentration estimation based on particle size distribution (SA PSD ) is a more accurate and convenient method to estimate surface area concentrations than estimation methods using inversion routines and may be feasible to use for classifying exposure groups and identifying exposure trends.

Ion climate and radon concentration

International Nuclear Information System (INIS)

Busbarna, L.

1981-01-01

Characteristic values of radon concentration in natural ion climate and in open air were compared and the effect of artificially produced negative ion excess on the radon concentration of air was studied. The results show that the radon concentration measurable at the rise of negative ion excess is smaller than that in the case of natural equilibrium. This effect can be utilized lowering the background of the scintillation chambers, thus increasing their sensitivity. The negative ions of the artificial ion climate lower radon concentration in closed space. The question arises whether only the ion climate is responsible for the effects on the organism and on the nervous system or the radon concentration of the air also contributes to them. (author)

Concentrating Radioactivity

Science.gov (United States)

Herrmann, Richard A.

1974-01-01

By concentrating radioactivity contained on luminous dials, a teacher can make a high reading source for classroom experiments on radiation. The preparation of the source and its uses are described. (DT)

A Concentrator Photovoltaic System Based on a Combination of Prism-Compound Parabolic Concentrators

Directory of Open Access Journals (Sweden)

Ngoc Hai Vu

2016-08-01

Full Text Available We present a cost-effective concentrating photovoltaic system composed of a prism and a compound parabolic concentrator (P-CPC. In this approach, the primary collector consists of a prism, a solid compound parabolic concentrator (CPC, and a slab waveguide. The prism, which is placed on the input aperture of CPC, directs the incoming sunlight beam to be parallel with the main axes of parabolic rims of CPC. Then, the sunlight is reflected at the parabolic rims and concentrated at the focal point of these parabolas. A slab waveguide is coupled at the output aperture of the CPC to collect focused sunlight beams and to guide them to the solar cell. The optical system was modeled and simulated with commercial ray tracing software (LightTools™. Simulation results show that the optical efficiency of a P-CPC can achieve up to 89%. when the concentration ratio of the P-CPC is fixed at 50. We also determine an optimal geometric structure of P-CPC based on simulation. Because of the simplicity of the P-CPC structure, a lower-cost mass production process is possible. A simulation based on optimal structure of P-CPC was performed and the results also shown that P-CPC has high angular tolerance for input sunlight. The high tolerance of the input angle of sunlight allows P-CPC solar concentrator utilize a single sun tracking system instead of a highly precise dual suntracking system as cost effective solution.

Optimal concentrations in transport systems

Science.gov (United States)

Jensen, Kaare H.; Kim, Wonjung; Holbrook, N. Michele; Bush, John W. M.

2013-01-01

Many biological and man-made systems rely on transport systems for the distribution of material, for example matter and energy. Material transfer in these systems is determined by the flow rate and the concentration of material. While the most concentrated solutions offer the greatest potential in terms of material transfer, impedance typically increases with concentration, thus making them the most difficult to transport. We develop a general framework for describing systems for which impedance increases with concentration, and consider material flow in four different natural systems: blood flow in vertebrates, sugar transport in vascular plants and two modes of nectar drinking in birds and insects. The model provides a simple method for determining the optimum concentration copt in these systems. The model further suggests that the impedance at the optimum concentration μopt may be expressed in terms of the impedance of the pure (c = 0) carrier medium μ0 as μopt∼2αμ0, where the power α is prescribed by the specific flow constraints, for example constant pressure for blood flow (α = 1) or constant work rate for certain nectar-drinking insects (α = 6). Comparing the model predictions with experimental data from more than 100 animal and plant species, we find that the simple model rationalizes the observed concentrations and impedances. The model provides a universal framework for studying flows impeded by concentration, and yields insight into optimization in engineered systems, such as traffic flow. PMID:23594815

Ideal 3D asymmetric concentrator

Energy Technology Data Exchange (ETDEWEB)

Garcia-Botella, Angel [Departamento Fisica Aplicada a los Recursos Naturales, Universidad Politecnica de Madrid, E.T.S.I. de Montes, Ciudad Universitaria s/n, 28040 Madrid (Spain); Fernandez-Balbuena, Antonio Alvarez; Vazquez, Daniel; Bernabeu, Eusebio [Departamento de Optica, Universidad Complutense de Madrid, Fac. CC. Fisicas, Ciudad Universitaria s/n, 28040 Madrid (Spain)

2009-01-15

Nonimaging optics is a field devoted to the design of optical components for applications such as solar concentration or illumination. In this field, many different techniques have been used for producing reflective and refractive optical devices, including reverse engineering techniques. In this paper we apply photometric field theory and elliptic ray bundles method to study 3D asymmetric - without rotational or translational symmetry - concentrators, which can be useful components for nontracking solar applications. We study the one-sheet hyperbolic concentrator and we demonstrate its behaviour as ideal 3D asymmetric concentrator. (author)

Antibiotic concentrations in intestinal mucosa.

Science.gov (United States)

Malmborg, A S

1985-01-01

The concentrations in the intestinal mucosa after the initial dose of cefoxitin, piperacillin and clindamycin have been studied. The antibiotics were given at the induction of anesthesia as prophylaxis to patients undergoing elective colorectal surgery. The concentrations of the antibiotics in serum and intestinal mucosa taken during the operation were determined by the microbiological agar diffusion method. Therapeutic concentrations in intestinal mucosa were maintained during the major part of the operation period. The mean mucosa/serum concentration ratios were for cefoxitin 0.4, for piperacillin 0.5 and for clindamycin 1.2.

Micro-evaporation electrolyte concentrator

NARCIS (Netherlands)

Timmer, B.H.; van Delft, K.M.; Olthuis, Wouter; Bergveld, Piet; van den Berg, Albert

2003-01-01

The sensitivity of miniaturized chemical analysis systems depends most of the time on the obtainable detection limit. Concentrating the analyte prior to the detection system can enhance the detection limit. In this writing an analyte concentrator is presented that makes use of evaporation to

Ownership concentration and bank profitability

Directory of Open Access Journals (Sweden)

Peterson Kitakogelu Ozili

2017-12-01

Full Text Available We investigate whether ownership concentration influences bank profitability in a developing country context. We focus on bank ownership concentration measured as the amount of direct equity held by a majority shareholder categorised into: high ownership concentration, moderate ownership concentration and disperse ownership. We find that banks with high ownership concentration have higher return on assets, higher net interest margin and higher recurring earning power while banks with dispersed ownership have lower return on assets but have higher return on equity. Also, higher cost efficiency improves the return on assets of widely-held banks and the return on equity of banks with moderate ownership. The findings have implications. JEL: Code: G3, G34, G31, Keywords: Corporate governance, Ownership structure, Agency theory, Profitability, Firm performance, Banks, Return on asset, Return on equity

Study of the Role of Terrestrial Processes in the Carbon Cycle Based on Measurements of the Abundance and Isotopic Composition of Atmospheric CO2

Energy Technology Data Exchange (ETDEWEB)

Piper, Stephen C; Keeling, Ralph F

2012-01-03

The main objective of this project was to continue research to develop carbon cycle relationships related to the land biosphere based on remote measurements of atmospheric CO2 concentration and its isotopic ratios 13C/12C, 18O/16O, and 14C/12C. The project continued time-series observations of atmospheric carbon dioxide and isotopic composition begun by Charles D. Keeling at remote sites, including Mauna Loa, the South Pole, and eight other sites. Using models of varying complexity, the concentration and isotopic measurements were used to study long-term change in the interhemispheric gradients in CO2 and 13C/12C to assess the magnitude and evolution of the northern terrestrial carbon sink, to study the increase in amplitude of the seasonal cycle of CO2, to use isotopic data to refine constraints on large scale changes in isotopic fractionation which may be related to changes in stomatal conductance, and to motivate improvements in terrestrial carbon cycle models. The original proposal called for a continuation of the new time series of 14C measurements but subsequent descoping to meet budgetary constraints required termination of measurements in 2007.

Confirmation of 5 SN in the Kepler/K2 C16 Field with Gemini

Science.gov (United States)

Margheim, S.; Tucker, B. E.; Garnavich, P. M.; Rest, A.; Narayan, G.; Smith, K. W.; Smartt, S.; Kasen, D.; Shaya, E.; Mushotzky, R.; Olling, R.; Villar, A.; Forster, F.; Zenteno, A.; James, D.; Smith, R. Chris

2018-01-01

We report new spectroscopic classifications by KEGS of supernova discovered by Pan-STARRS1 during a targeted search of the Kepler/K2 Campaign 16 field using the Gemini Multi-Object Spectrograph (GMOS) on both the Gemini North Observatory on Mauna Kea, and the Gemini South Observatory on Cerro Pachon.

Compensation of self-absorption losses in luminescent solar concentrators by increasing luminophore concentration

NARCIS (Netherlands)

Krumer, Zachar; van Sark, Wilfried G.J.H.M.; Schropp, Ruud E.I.; de Mello Donegá, Celso

2017-01-01

Self-absorption in luminophores is considered a major obstacle on the way towards efficient luminescent solar concentrators (LSCs). It is commonly expected that upon increasing luminophore concentration in an LSC the absorption of the luminophores increases as well and therefore self-absorption

Free amino nitrogen concentration correlates to total yeast assimilable nitrogen concentration in apple juice

OpenAIRE

Boudreau, Thomas F.; Peck, Gregory M.; O'Keefe, Sean F.; Stewart, Amanda C.

2017-01-01

Abstract Yeast assimilable nitrogen (YAN) is essential for yeast growth and metabolism during apple (Malus x domestica Borkh.) cider fermentation. YAN concentration and composition can impact cider fermentation kinetics and the formation of volatile aroma compounds by yeast. The YAN concentration and composition of apples grown in Virginia, USA over the course of two seasons was determined through analysis of both free amino nitrogen (FAN) and ammonium ion concentration. FAN was the largest f...

Ideal flux field dielectric concentrators.

Science.gov (United States)

García-Botella, Angel

2011-10-01

The concept of the vector flux field was first introduced as a photometrical theory and later developed in the field of nonimaging optics; it has provided new perspectives in the design of concentrators, overcoming standard ray tracing techniques. The flux field method has shown that reflective concentrators with the geometry of the field lines achieve the theoretical limit of concentration. In this paper we study the role of surfaces orthogonal to the field vector J. For rotationally symmetric systems J is orthogonal to its curl, and then a family of surfaces orthogonal to the lines of J exists, which can be called the family of surfaces of constant pseudopotential. Using the concept of the flux tube, it is possible to demonstrate that refractive concentrators with the shape of these pseudopotential surfaces achieve the theoretical limit of concentration.

Study on high concentration solar concentrator using a Fresnel lens with a secondary concentrator; Fresnel lens to niji shukokei wo mochiita solar chemistry yo kobairitsu shukokei ni kansuru kenkyu

Energy Technology Data Exchange (ETDEWEB)

Aihara, T; Suzuki, A; Fujibayashi, K [Tokyo University of Agriculture and Technology, Tokyo (Japan)

1997-11-25

A high concentration light collection system for solar chemistry was devised by using an inexpensive Fresnel lens in a primary concentration system and a conical type concentrator in a secondary concentration system. A Fresnel lens alone would not achieve sufficiently high light collecting magnification to attain high temperatures because of restrictions in the opening angle as seen from a focus. Therefore, a secondary concentration system was installed on a focus for an attempt of stopping. Reflection plane of a three-dimensional compound parabolic concentrator (CPC) is a rotary parabolic plane, whose process is expensive because of its surface processing accuracy. Therefore, a conical type concentrator was employed as a secondary concentration system. This system may not be capable of achieving as high concentration as in the CPC, but its shape is simple and it is inexpensive. In its optimization, a complete black body surface placed in vacuum atmosphere was hypothesized as a light concentrating part for the secondary concentration system to calculate heat collecting efficiencies at respective temperature settings. Using simultaneously the secondary concentration system, rather than collecting heat by using a Fresnel lens alone, has attained as high value as from 5.99% (500 degC) to 43.47% (1400 degC). Economical high-temperature heat collection of solar chemistry level may be possible by using a Fresnel lens and a conical secondary concentration system. 1 ref., 7 figs., 2 tabs.

MARKET CONCENTRATION IN TURKISH JOURNALISM SECTOR

Directory of Open Access Journals (Sweden)

ADEM KALÇA

2013-05-01

Full Text Available Concentration is a situation in which market structure of a sector is controlled by a few firms. At the present time, many analyzing methods such as Herfindahl-Hirschman and N-Firm Concentration Indexes are used to determine market structure.According to market concentration indexes, higher concentration level means more monopolistic market structure, lower concentration level means more full competitive market structure. In this study concentration levels of media groups in Turkish journalism sector within the scope of traditional journalism and internet journalism was analyzed via N-Firm Concentration and H-H Indexes. As a result of the study, it’s seen that first four biggest media groups have monopolistic competition in internet journalism sector,and oligopol structure in traditional journalism sector. According to H-H index analyze, there is monopolistic competition in the sector.

Measurements of natural 41Ca concentrations

International Nuclear Information System (INIS)

Steinhof, A.

1989-05-01

Atomic mass spectroscopic examinations on 41 Ca were carried out in the UNILAC accelerator. A sensitivity of about 10 -15 was achieved. This would allow the measurement of present natural 41 Ca concentrations as soon as the problem of the transmission determination is solved. In this respect suggestions were worked out and their feasibility discussed. The detection of 41 Ca-ions is especially free of background when high UNILAC-energies are applied. An estimation showed a background level corresponding with a 41 Ca concentration of less then 10 -17 referred to 40 Ca. Besides an independent concept for the electromagnetic concentration of 41 Ca with variable concentration factors was developed. After being concentrated up to 50 respectively 25 times the initial concentration in the GSI mass separator, the 41 Ca concentration of three recent deer bones found in the Odenwald was measured by atomic mass spectroscopy in the 14UD-Pelletron Tandem in Rehovot (Israel). The measured 41 Ca concentrations ranged between 10 -14 to 10 -13 with consideration of the concentration factor. A theoretical study of the 41 Ca production in the earth's surface based on cosmic radiation illustrates the influence of trace elements on the neutron flux and thus on the 41 Ca production. This influence might be a possible explanation for the observed amplitude of variation of the 41 Ca concentration in recent bones which are of decisive importance for the feasibility of 41 Ca-related dating. In this work a method is suggested that does not depend on the amplitude of variation mentioned above and which would allow the determination of the erosion rate of rocks by its 41 Ca concentrations. (orig./HP) [de

A Microfluidic Cell Concentrator

Science.gov (United States)

Warrick, Jay; Casavant, Ben; Frisk, Megan; Beebe, David

2010-01-01

Cell concentration via centrifugation is a ubiquitous step in many cell culture procedures. At the macroscale, centrifugation suffers from a number of limitations particularly when dealing with small numbers of cells (e.g., less than 50,000). On the other hand, typical microscale methods for cell concentration can affect cell physiology and bias readouts of cell behavior and function. In this paper, we present a microfluidic concentrator device that utilizes the effects of gravity to allow cells to gently settle out of a suspension into a collection region without the use of specific adhesion ligands. Dimensional analysis was performed to compare different device designs and was verified with flow modeling to optimize operational parameters. We are able to concentrate low-density cell suspensions in a microfluidic chamber, achieving a cell loss of only 1.1 ± 0.6% (SD, n=7) with no observed loss during a subsequent cell staining protocol which incorporates ~36 complete device volume replacements. This method provides a much needed interface between rare cell samples and microfluidic culture assays. PMID:20843010

The concentration of retail in Poland

Directory of Open Access Journals (Sweden)

Michał Gazdecki

2010-01-01

Full Text Available The article discusses the processes of concentration taking place in retail in Poland. In spite of strong concentration processes, which took place after 2000, Poland still remains a country of dispersed retail structure. In the nearest years we can expect capital concentration (mainly takeovers in modern trade and contract concentration (for example, merchants’ societies in traditional trade.

Thin-source concentration dependent diffusion

International Nuclear Information System (INIS)

Eng, G.

1978-01-01

The diffusion of (Ca ++ ) in NaCl has been measured for various diffusion times and for the temperature range (575 0 to 775 0 C), using a thin-source of 45 Ca tracer, rectangular geometry, and serial sectioning. The pre-diffusion surface concentration was approximately 3 x 10 16 (Ca)-atoms/cm 2 , which, for an average penetration depth of 100 to 300 μm, produces a maximum (post-diffusion) impurity concentration comparable to or greater than the intrinsic cation vacancy concentration. The high-temperature function closely matches the D 0 (T) function obtained from low impurity concentration experiments. The lower-temperature function, combined with the sudden failure of the D(C) = D 0 (1 + [C] + 0.5[C] 2 ) function at these lower temperatures, indicates the onset of a second diffusion process, one which would operate only at extremely high impurity concentrations. This low-temperature behavior is shown to be consistent with a breakdown of the conditions assumed for vacancy equilibrium

Silicon concentrator cells in a two-stage photovoltaic system with a concentration factor of 300x

Energy Technology Data Exchange (ETDEWEB)

Mohr, A.

2005-06-15

In this work a rear contacted silicon concentrator cell was developed for an application in a two stage concentrator photovoltaic system. This system was developed at Fraunhofer ISE some years ago. The innovation of this one-axis tracked system is that it enables a high geometrical concentration of 300x in combination with a high optical efficiency (around 78%) and a large acceptance angle of {+-}23.5 all year through. For this, the system uses a parabolic mirror (40.4x) and a three dimensional second stage consisting of compound parabolic concentrators (CPCs, 7.7x). For the concentrator concept and particularly for an easy cell integration, the rear line contacted concentrator (RLCC) cells with a maximum efficiency of 25% were developed and a hybrid mounting concept for the RLCC cells is presented. The optical performance of different CPC materials was tested and analysed in this work. Finally, small modules consisting of six series interconnected RLCC cells and six CPCs were integrated into the concentrator system and tested outdoor. A system efficiency of 16.2% was reached at around 800 W/m2 direct irradiance under realistic outdoor conditions. (orig.)

Tritium concentrations in tree ring cellulose

International Nuclear Information System (INIS)

Kaji, Toshio; Momoshima, Noriyuki; Takashima, Yoshimasa.

1989-01-01

Measurements of tritium (tissue bound tritium; TBT) concentration in tree rings are presented and discussed. Such measurement is expected to provide a useful means of estimating the tritium level in the environment in the past. The concentration of tritium bound in the tissue (TBT) in a tree ring considered to reflect the environmental tritium level in the area at the time of the formation of the ring, while the concentration of tritium in the free water in the tissue represents the current environmental tritium level. First, tritium concentration in tree ring cellulose sampled from a cedar tree grown in a typical environment in Fukuoka Prefecture is compared with the tritium concentration in precipitation in Tokyo. Results show that the year-to-year variations in the tritium concentration in the tree rings agree well with those in precipitation. The maximum concentration, which occurred in 1963, is attibuted to atmospheric nuclear testing which was performed frequently during the 1961 - 1963 period. Measurement is also made of the tritium concentration in tree ring cellulose sampled from a pine tree grown near the Isotope Center of Kyushu University (Fukuoka). Results indicate that the background level is higher probably due to the release of tritium from the facilities around the pine tree. Thus, measurement of tritium in tree ring cellulose clearly shows the year-to-year variation in the tritium concentration in the atmosphere. (N.K.)

Relations between fatty acid synthesis, pyruvate concentration and cell concentration of suspensions of isolated rat hepatocytes

NARCIS (Netherlands)

Beynen, A.C.; Geelen, M.J.H.

1984-01-01

1. 1. The cell concentration of suspensions of isolated rat hepatocytes affects both the rate of pyruvate accumulation in the incubation medium and the rate of fatty acid synthesis. 2. 2. At low cell concentrations pyruvate accumulation is directly related to the cell concentration but levels off

High-flux solar concentration with imaging designs

Energy Technology Data Exchange (ETDEWEB)

Feuermann, D. [Ben-Gurion University of the Negev (Israel). Jacob Blaustein Institute for Desert Research; Gordon, J.M. [Ben-Gurion University of the Negev (Israel). Jacob Blaustein Institute for Desert Research; Ben-Gurion University of the Negev (Israel). Dept. of Mechanical Engineering; Ries, H. [Ries and Partners, Munich (Germany)

1999-02-01

Most large solar concentrators designed for high flux concentration at high collection efficiency are based on imaging primary mirrors and nonimaging secondary concentrators. In this paper, we offer an alternative purely imaging two-stage solar concentrator that can attain high flux concentration at high collection efficiency. Possible practical virtues include: (1) an inherent large gap between absorber and secondary mirror; (2) a restricted angular range on the absorber; and (3) an upward-facing receiver where collected energy can be extracted via the (shaded) apex of the parabola. We use efficiency-concentration plots to characterize the solar concentrators considered, and to evaluate the potential improvements with secondary concentrators. (author)

Probiotic Yoghurts From Ultrafiltered Concentrated Milk

Directory of Open Access Journals (Sweden)

Kozludzhova Siyka

2015-12-01

Full Text Available In this paper, yoghurts from ultrafiltered concentrated whole milk with a volume reduction ratio 0, 2 and 3 with three different probiotic yoghurt starters were obtained. Their physiological, microbiological and rheological properties were examined. The concentrated probiotic yoghurts had high concentration of viable cells of the probiotic strain Lactobacillus delbrueckii ssp. bulgaricus (over 1010cfu/cm3. For the preparation of concentrated probiotic yoghurts the most appropriate volume reduction ratio was 2. The probiotic yoghurts with starters MZ2 and 1CM had the best structure. The concentrated probiotic yoghurts with all starters are functional foods.

Maximum concentrations at work and maximum biologically tolerable concentration for working materials 1991

International Nuclear Information System (INIS)

1991-01-01

The meaning of the term 'maximum concentration at work' in regard of various pollutants is discussed. Specifically, a number of dusts and smokes are dealt with. The valuation criteria for maximum biologically tolerable concentrations for working materials are indicated. The working materials in question are corcinogeneous substances or substances liable to cause allergies or mutate the genome. (VT) [de

Modeling sediment concentration of rill flow

Science.gov (United States)

Yang, Daming; Gao, Peiling; Zhao, Yadong; Zhang, Yuhang; Liu, Xiaoyuan; Zhang, Qingwen

2018-06-01

Accurate estimation of sediment concentration is essential to establish physically-based erosion models. The objectives of this study were to evaluate the effects of flow discharge (Q), slope gradient (S), flow velocity (V), shear stress (τ), stream power (ω) and unit stream power (U) on sediment concentration. Laboratory experiments were conducted using a 10 × 0.1 m rill flume under four flow discharges (2, 4, 8 and 16 L min-1), and five slope gradients (5°, 10°, 15°, 20° and 25°). The results showed that the measured sediment concentration varied from 87.08 to 620.80 kg m-3 with a mean value of 343.13 kg m-3. Sediment concentration increased as a power function with flow discharge and slope gradient, with R2 = 0.975 and NSE = 0.945. The sediment concentration was more sensitive to slope gradient than to flow discharge. The sediment concentration was well predicted by unit stream power (R2 = 0.937, NSE = 0.865), whereas less satisfactorily by flow velocity (R2 = 0.470, NSE = 0.539) and stream power (R2 = 0.773, NSE = 0.732). In addition, using the equations to simulate the measured sediment concentration of other studies, the result further indicated that slope gradient, flow discharge and unit stream power were good predictors of sediment concentration. In general, slope gradient, flow discharge and unit stream power seem to be the preferred predictors for estimating sediment concentration.

Challenges and Opportunities in Developing the Hawaiian Scientific and Technical Workforce

Science.gov (United States)

Kennedy, James R.

2012-01-01

In searching for dark skies, persistently clear weather, and minimal atmospheric interference, astronomical observing sites are generally located in remote, mountainous locations, and usually far from large communities. Such locations often have weak economies, and shallow workforce pools in the technical and administrative areas generally needed by the observatories. This leads to a problem, and an opportunity, for both the observatories and their local communities. Importing employees from far away locations is costly, leads to high turnover, and deprives the community of economic benefits and the sense of fealty with the observatories that would naturally result if local people occupied these comparatively good paying jobs. While by no means unique, the observatories on Mauna Kea Hawai`i are a clear example of this dual dilemma. This presentation will report findings from a model workforce needs assessment survey of all the Mauna Kea observatories, which has establish likely annual staffing requirements in several categories of technological and administrative support, including the educational entrance requirements. Results indicated that through 2023, 80% of observatory job openings on Hawai`i Island will be in technology and administration. Furthermore, the vast majority of these jobs will require only a two-year or four-year college degree in a relevant field as an entrance requirement. Efforts to realign the existing resources to better meet these common needs will be discussed, including the highly successful partnership between County of Hawai`i Workforce Development Board, the Mauna Kea observatories, the local K-12 systems, Hawai`i Community College, the University of Hawai`i Hilo, and a number of informal education and workplace experience programs. This collaboration has resulted in no fewer than three, interlocked, community programs have stepped up to meet this challenge to the benefit of both the local community and the observatories.

Nonimaging concentrators for solar thermal energy

Science.gov (United States)

Winston, R.; Gallagher, J. J.

1980-03-01

A small experimental solar collector test facility was used to explore applications of nonimaging optics for solar thermal concentration in three substantially different configurations: a single stage system with moderate concentration on an evacuated absorber (a 5.25X evacuated tube Compound Parabolic Concentrator or CPC), a two stage system with high concentration and a non-evacuated absorber (a 16X Fresnel lens/CPC type mirror) and moderate concentration single stage systems with non-evacuated absorbers for lower temperature (a 3X and a 6.5X CPC). Prototypes of each of these systems were designed, built and tested. The performance characteristics are presented.

Comparison of the Force-, Velocity- and Power-Time Curves Between the Concentric-Only and Eccentric-Concentric Bench Press Exercises.

Science.gov (United States)

Pérez-Castilla, Alejandro; Comfort, Paul; McMahon, John J; Pestaña-Melero, Francisco Luis; García-Ramos, Amador

2018-01-17

The aim of this study was to compare the temporal and mechanical variables between the concentric-only and eccentric-concentric bench press (BP) variants. Twenty-one men (age: 22.0±4.2 years, body mass: 73.4±7.7 kg, height: 177.2±8.0 cm; one-repetition maximum [1RM]: 1.12±0.12 kg⋅kg) were evaluated during the concentric-only and eccentric-concentric BP variants using 80% 1RM. Temporal (concentric phase duration, propulsive phase duration, and time to reach the maximum values of force, velocity, and power) and mechanical variables (force, velocity, and power), determined using a linear velocity transducer, were compared between both BP variants. All temporal variables were significantly lower during the eccentric-concentric BP compared to the concentric-only BP (P velocity and power were significantly higher for the eccentric-concentric BP compared to the concentric-only BP (all P velocity (ES: 0.40) and power (ES: 0.41). The stretch-shortening cycle (i.e., eccentric-concentric BP) mainly enhanced force production at the early portion of the concentric phase, but this potentiation effect gradually reduced over the latter part of the movement. Finally, force was higher for the concentric-only BP during 49% of the concentric phase duration. These results suggest that both BP variants should be included during resistance training programs in order to optimize force output at different points of the concentric phase.

A concentration-independent micro/nanofluidic active diode using an asymmetric ion concentration polarization layer.

Science.gov (United States)

Lee, Hyekyung; Kim, Junsuk; Kim, Hyeonsoo; Kim, Ho-Young; Lee, Hyomin; Kim, Sung Jae

2017-08-24

Over the past decade, nanofluidic diodes that rectify ionic currents (i.e. greater current in one direction than in the opposite direction) have drawn significant attention in biomolecular sensing, switching and energy harvesting devices. To obtain current rectification, conventional nanofluidic diodes have utilized complex nanoscale asymmetry such as nanochannel geometry, surface charge density, and reservoir concentration. Avoiding the use of sophisticated nano-asymmetry, micro/nanofluidic diodes using microscale asymmetry have been recently introduced; however, their diodic performance is still impeded by (i) low (even absent) rectification effects at physiological concentrations over 100 mM and strong dependency on the bulk concentration, and (ii) the fact that they possess only passive predefined rectification factors. Here, we demonstrated a new class of micro/nanofluidic diode with an ideal perm-selective nanoporous membrane based on ion concentration polarization (ICP) phenomenon. Thin side-microchannels installed near a nanojunction served as mitigators of the amplified electrokinetic flows generated by ICP and induced convective salt transfer to the nanoporous membrane, leading to actively controlled micro-scale asymmetry. Using this device, current rectifications were successfully demonstrated in a wide range of electrolytic concentrations (10 -5 M to 3 M) as a function of the fluidic resistance of the side-microchannels. Noteworthily, it was confirmed that the rectification factors were independent from the bulk concentration due to the ideal perm-selectivity. Moreover, the rectification of the presenting diode was actively controlled by adjusting the external convective flows, while that of the previous diode was passively determined by invariant nanoscale asymmetry.

Variable aromatase inhibitor plasma concentrations do not correlate with circulating estrogen concentrations in post-menopausal breast cancer patients.

Science.gov (United States)

Hertz, Daniel L; Speth, Kelly A; Kidwell, Kelley M; Gersch, Christina L; Desta, Zeruesenay; Storniolo, Anna Maria; Stearns, Vered; Skaar, Todd C; Hayes, Daniel F; Henry, N Lynn; Rae, James M

2017-10-01

The aromatase inhibitors (AI) exemestane (EXE), letrozole (LET), and anastrozole suppress estrogen biosynthesis, and are effective treatments for estrogen receptor (ER)-positive breast cancer. Prior work suggests that anastrozole blood concentrations are associated with the magnitude of estrogen suppression. The objective of this study was to determine whether the magnitude of estrogen suppression, as determined by plasma estradiol (E2) concentrations, in EXE or LET treated patients is associated with plasma AI concentrations. Five hundred post-menopausal women with ER-positive breast cancer were enrolled in the prospective Exemestane and Letrozole Pharmacogenetic (ELPh) Study conducted by the COnsortium on BReast cancer phArmacogomics (COBRA) and randomly assigned to either drug. Estrogen concentrations were measured at baseline and after 3 months of AI treatment and drug concentrations were measured after 1 or 3 months. EXE or LET concentrations were compared with 3-month E2 concentration or the change from baseline to 3 months using several complementary statistical procedures. Four-hundred patients with on-treatment E2 and AI concentrations were evaluable (EXE n = 200, LET n = 200). Thirty (7.6%) patients (EXE n = 13, LET n = 17) had 3-month E2 concentrations above the lower limit of quantification (LLOQ) (median: 4.75; range: 1.42-63.8 pg/mL). EXE and LET concentrations were not associated with on-treatment E2 concentrations or changes in E2 concentrations from baseline (all p > 0.05). Steady-state plasma AI concentrations do not explain variability in E2 suppression in post-menopausal women receiving EXE or LET therapy, in contrast with prior evidence in anastrozole treated patients.

Method of enriching oil shale concentrate

Energy Technology Data Exchange (ETDEWEB)

Larsson, M

1942-02-14

The method is characterized by producing one concentrate first and then this concentrate, in water solution using suitable apparatus, is separated by settling into one heavier bottom portion, rich in mineral matter, and into a lighter slime containing concentrated organic substance.

Dense medium ore concentrates of Bois-Noirs; Minerais des bois noirs, concentres de milieu dense

Energy Technology Data Exchange (ETDEWEB)

Le Bris, J; Leduc, M

1959-01-20

The chemical treatment of uranium concentrates of Bois-Noirs ore obtained by heavy medium are discussed. The first part deals with sulfuric acid attack on the concentrate, and the second part with the separation of the solution from residues by filtration. A third part deals with this separation by decantation. The fourth part deals with the carbonation of the pickling solutions obtained. (author) [French] Le present rapport est relatif a l'etude du traitement chimique de concentres uraniferes de minerais des Bois-Noirs obtenus par milieu dense. Une premiere partie est consacree a l'attaque sulfurique des concentres, une deuxieme partie a Ia separation de Ia solution d'attaque des residus par decantation. Une quatrieme partie a la carbonatation des solutions d'attaque obtenues. (auteur)

Thermodynamic efficiency of solar concentrators.

Science.gov (United States)

Shatz, Narkis; Bortz, John; Winston, Roland

2010-04-26

The optical thermodynamic efficiency is a comprehensive metric that takes into account all loss mechanisms associated with transferring flux from the source to the target phase space, which may include losses due to inadequate design, non-ideal materials, fabrication errors, and less than maximal concentration. We discuss consequences of Fermat's principle of geometrical optics and review étendue dilution and optical loss mechanisms associated with nonimaging concentrators. We develop an expression for the optical thermodynamic efficiency which combines the first and second laws of thermodynamics. As such, this metric is a gold standard for evaluating the performance of nonimaging concentrators. We provide examples illustrating the use of this new metric for concentrating photovoltaic systems for solar power applications, and in particular show how skewness mismatch limits the attainable optical thermodynamic efficiency.

Design of nonimaging concentrators as second stages in tandem with image-forming first-stage concentrators

Science.gov (United States)

Winston, R.; Welford, W. T.

1980-02-01

The paper discusses the paraboloidal mirror as a tracking solar concentrator, fitting a nonimaging second stage to the paraboloidal mirror, other image-forming systems as first stages, and tracking systems in two-dimensional geometry. Because of inherent aberrations, the paraboloidal mirror cannot achieve the thermodynamic limit. It is shown how paraboloidal mirrors of short focal ratio and similar systems can have their flux concentration enhanced to near the thermodynamic limit by the addition of nonimaging compound elliptical concentrators.

Design of nonimaging concentrators as second stages in tandem with image-forming first-stage concentrators

Science.gov (United States)

Winston, R.; Welford, W. T.

1980-01-01

The paper discusses the paraboloidal mirror as a tracking solar concentrator, fitting a nonimaging second stage to the paraboloidal mirror, other image-forming systems as first stages, and tracking systems in two-dimensional geometry. Because of inherent aberrations, the paraboloidal mirror cannot achieve the thermodynamic limit. It is shown how paraboloidal mirrors of short focal ratio and similar systems can have their flux concentration enhanced to near the thermodynamic limit by the addition of nonimaging compound elliptical concentrators.

Scattering Solar Thermal Concentrators

Energy Technology Data Exchange (ETDEWEB)

Giebink, Noel C. [Pennsylvania State Univ., State College, PA (United States)

2015-01-31

This program set out to explore a scattering-based approach to concentrate sunlight with the aim of improving collector field reliability and of eliminating wind loading and gross mechanical movement through the use of a stationary collection optic. The approach is based on scattering sunlight from the focal point of a fixed collection optic into the confined modes of a sliding planar waveguide, where it is transported to stationary tubular heat transfer elements located at the edges. Optical design for the first stage of solar concentration, which entails focusing sunlight within a plane over a wide range of incidence angles (>120 degree full field of view) at fixed tilt, led to the development of a new, folded-path collection optic that dramatically out-performs the current state-of-the-art in scattering concentration. Rigorous optical simulation and experimental testing of this collection optic have validated its performance. In the course of this work, we also identified an opportunity for concentrating photovoltaics involving the use of high efficiency microcells made in collaboration with partners at the University of Illinois. This opportunity exploited the same collection optic design as used for the scattering solar thermal concentrator and was therefore pursued in parallel. This system was experimentally demonstrated to achieve >200x optical concentration with >70% optical efficiency over a full day by tracking with <1 cm of lateral movement at fixed latitude tilt. The entire scattering concentrator waveguide optical system has been simulated, tested, and assembled at small scale to verify ray tracing models. These models were subsequently used to predict the full system optical performance at larger, deployment scale ranging up to >1 meter aperture width. Simulations at an aperture widths less than approximately 0.5 m with geometric gains ~100x predict an overall optical efficiency in the range 60-70% for angles up to 50 degrees from normal. However, the

Concentrating Solar Power Projects - Khi Solar One | Concentrating Solar

Science.gov (United States)

Power | NREL Khi Solar One This page provides information on Khi Solar One, a concentrating solar power (CSP) project, with data organized by background, parcipants and power plant configuration . Status Date: February 8, 2016 Project Overview Project Name: Khi Solar One Country: South Africa Location

Conical electromagnetic radiation flux concentrator

Science.gov (United States)

Miller, E. R.

1972-01-01

Concentrator provides method of concentrating a beam of electromagnetic radiation into a smaller beam, presenting a higher flux density. Smaller beam may be made larger by sending radiation through the device in the reverse direction.

Cementification for radioactive waste including high-concentration sodium sulfate and high-concentration radioactive nuclide

International Nuclear Information System (INIS)

Miyamoto, Shinya; Sato, Tatsuaki; Sasoh, Michitaka; Sakurai, Jiro; Takada, Takao

2005-01-01

For the cementification of radioactive waste that has large concentrations of sodium sulfate and radioactive nuclide, a way of fixation for sulfate ion was studied comprising the pH control of water in contact with the cement solid, and the removal of the excess water from the cement matrix to prevent hydrogen gas generation with radiolysis. It was confirmed that the sulfate ion concentration in the contacted water with the cement solid is decreased with the formation of ettringite or barium sulfate before solidification, the pH value of the pore water in the cement solid can control less than 12.5 by the application of zeolite and a low-alkali cement such as alumina cement or fly ash mixed cement, and removal of the excess water from the cement matrix by heating is possible with aggregate addition. Consequently, radioactive waste including high-concentration sodium sulfate and high-concentration radioactive nuclide can be solidified with cementitious materials. (author)

Effects of Elevated CO2 Concentration on the Biomasses and Nitrogen Concentrations in the Organs of Sainfoin(Onobrychis viciaefolia Scop.)

Institute of Scientific and Technical Information of China (English)

ZHOU Zheng-chao; SHANGGUAN Zhou-ping

2009-01-01

In forage grasses,the nitrogen concentration is directly related to the nutritional value.The studies examined the hypothesis that global elevation of CO2 concentration probably affects the biomass,nitrogen(N)concentration,and allocation and distribution patterns in the organs of forage grasses.While sainfoin(Onobrychis viciaefolia Scop.)seedlings grew on a low nutrient soil in closed chambers for 90 days,they were exposed to two CO2 concentrations(ambient or ambient+350μmol mol-1 CO2)without adding nutrients to them.After 90 days exposure to CO2,the biomasses of leaves,stems,and roots,and N concentrations and contents of different parts were measured.Compared with the ambient CO2 concentration,the elevated CO2 concentration increased the total dry matter by 25.07%,mainly due to the root and leaf having positive response to the elevated CO2 concentration.However,the elevated CO2 concentration did not change the proportions of the dry matters in different parts and the total plants compared with the ambient CO2 concentration.The elevated CO2 concentration lowered the N concentrations of the plant parts.Because the dry matter was higher,the elevated CO2 concentration had no effect on the N content in the plants compared to the ambient CO2 concentration.The elevated CO2 concentration promoted N allocations of the different parts significantly and increased N allocation of the underground part.The results have confirmed the previous suggestions that the elevated CO2 concentration stimulates plant biomass production and decreases the N concentrations of the plant parts.

In vitro-in vivo extrapolation: estimation of human serum concentrations of chemicals equivalent to cytotoxic concentrations in vitro

International Nuclear Information System (INIS)

Guelden, Michael; Seibert, Hasso

2003-01-01

In the present study an extrapolation model for estimating serum concentrations of chemicals equivalent to in vitro effective concentrations is developed and applied to median cytotoxic concentrations (EC 50 ) determined in vitro. Nominal concentrations of a chemical in serum and in vitro are regarded as equivalent, if they result in the same aqueous concentration of the unbound form. The algorithm used is based on equilibrium distribution and requires albumin binding data, the octanol-water partition coefficient (K ow ), and the albumin concentrations and lipid volume fractions in vitro and in serum. The chemicals studied cover wide ranges of cytotoxic potency (EC 50 : 2.5-530000 μM) and lipophilicity (log K ow : -5 to 7). Their albumin binding characteristics have been determined by means of an in vitro cytotoxicity test as described previously. The equivalent serum concentrations of 19 of the 33 compounds investigated, having high protein binding and/or lipophilicity, were substantially higher than the EC 50 -values, by factors of 2.5-58. Prominent deviations between the equivalent nominal concentrations in serum and in vitro were largely restricted to chemicals with higher cytotoxic potency (EC 50 ≤1000 μM). The results suggest that estimates of equivalent serum concentrations based on in vitro data are robust for chemicals with low lipophilicity (log K ow ≤2) and low potency (EC 50 >1000 μM). With more potent chemicals or those with higher lipophilicity partitioning into lipids and/or binding to serum proteins have to be taken into account when estimating in vivo serum concentrations equivalent to in vitro effective concentrations

Quality assessment of platelet concentrates prepared by platelet rich plasma-platelet concentrate, buffy coat poor-platelet concentrate (BC-PC and apheresis-PC methods

Directory of Open Access Journals (Sweden)

Singh Ravindra

2009-01-01

Full Text Available Background: Platelet rich plasma-platelet concentrate (PRP-PC, buffy coat poor-platelet concentrate (BC-PC, and apheresis-PC were prepared and their quality parameters were assessed. Study Design: In this study, the following platelet products were prepared: from random donor platelets (i platelet rich plasma - platelet concentrate (PRP-PC, and (ii buffy coat poor- platelet concentrate (BC-PC and (iii single donor platelets (apheresis-PC by different methods. Their quality was assessed using the following parameters: swirling, volume of the platelet concentrate, platelet count, WBC count and pH. Results: A total of 146 platelet concentrates (64 of PRP-PC, 62 of BC-PC and 20 of apheresis-PC were enrolled in this study. The mean volume of PRP-PC, BC-PC and apheresis-PC was 62.30±22.68 ml, 68.81±22.95 ml and 214.05±9.91 ml and ranged from 22-135 ml, 32-133 ml and 200-251 ml respectively. The mean platelet count of PRP-PC, BC-PC and apheresis-PC was 7.6±2.97 x 1010/unit, 7.3±2.98 x 1010/unit and 4.13±1.32 x 1011/unit and ranged from 3.2-16.2 x 1010/unit, 0.6-16.4 x 1010/unit and 1.22-8.9 x 1011/unit respectively. The mean WBC count in PRP-PC (n = 10, BC-PC (n = 10 and apheresis-PC (n = 6 units was 4.05±0.48 x 107/unit, 2.08±0.39 x 107/unit and 4.8±0.8 x 106/unit and ranged from 3.4 -4.77 x 107/unit, 1.6-2.7 x 107/unit and 3.2 - 5.2 x 106/unit respectively. A total of 26 units were analyzed for pH changes. Out of these units, 10 each were PRP-PC and BC-PC and 6 units were apheresis-PC. Their mean pH was 6.7±0.26 (mean±SD and ranged from 6.5 - 7.0 and no difference was observed among all three types of platelet concentrate. Conclusion: PRP-PC and BC-PC units were comparable in terms of swirling, platelet count per unit and pH. As expected, we found WBC contamination to be less in BC-PC than PRP-PC units. Variation in volume was more in BC-PC than PRP-PC units and this suggests that further standardization is required for preparation of BC

Concentrating Solar Power Projects - Nevada Solar One | Concentrating Solar

Science.gov (United States)

Power | NREL Nevada Solar One This page provides information on Nevada Solar One, a concentrating solar power (CSP) project, with data organized by background, participants, and power plant configuration. Acciona Energy's Nevada Solar One is the third largest CSP plant in the world and the first plant

Simulation and development of a multi-leg homogeniser concentrating assembly for concentrated photovoltaic (CPV) system with electrical rating analysis

International Nuclear Information System (INIS)

Burhan, Muhammad; Chua, Kian Jon Ernest; Ng, Kim Choon

2016-01-01

Highlights: • Novel multi-leg homogeniser concentrating assembly is developed for CPV system. • Single set of concentrator, concentrates sunlight on 4 MJCs with 1° acceptance angle. • The system performance is analyzed through experiment and ray tracing simulation. • Mini two axis solar tracker, with high tracking accuracy, is developed and tested. • Electrical rating analysis accurately estimates CPV system performance in any region. - Abstract: Concentrated photovoltaic (CPV) system utilizing multi-junction solar cells, is the main focus for current research, offering highest efficiency among all photovoltaic systems. The main aspect of CPV system is the design and performance of concentrating assembly, as it determines the performance of whole CPV system. However, the conventional design of CPV concentrating assembly dedicates one concentrator for each solar cell, in which single concentrator is capable to concentrate solar radiation onto single solar cell. This paper proposes a novel concentrating assembly for CPV system, which is designed to concentrate solar radiation onto four multi-junction solar cells with a single set of concentrators. The proposed design not only can reduce the number of concentrators and assembly efforts for CPV systems, but also achieved an acceptance angle of 1°. In this paper, the proposed multi-leg homogeniser CPV concentrating assembly is designed, developed, experimentally tested and verified through ray tracing simulation. The paper also discuss the development of mini, precise and accurate but cost effective two axis solar tracker for CPV system, which can be installed at any location even at rooftop of residential buildings, unlike conventional large scale CPV systems. Moreover, through the electrical rating analysis of the developed CPV system, its performance can be accurately estimated in any region.

New method of design of nonimaging concentrators.

Science.gov (United States)

Miñano, J C; González, J C

1992-06-01

A new method of designing nonimaging concentrators is presented and two new types of concentrators are developed. The first is an aspheric lens, and the second is a lens-mirror combination. A ray tracing of three-dimensional concentrators (with rotational symmetry) is also done, showing that the lens-mirror combination has a total transmission as high as that of the full compound parabolic concentrators, while their depth is much smaller than the classical parabolic mirror-nonimaging concentrator combinations. Another important feature of this concentrator is that the optically active surfaces are not in contact with the receiver, as occurs in other nonimaging concentrators in which the rim of the mirror coincides with the rim of the receiver.

Optical characterization of nonimaging dish concentrator for the application of dense-array concentrator photovoltaic system.

Science.gov (United States)

Tan, Ming-Hui; Chong, Kok-Keong; Wong, Chee-Woon

2014-01-20

Optimization of the design of a nonimaging dish concentrator (NIDC) for a dense-array concentrator photovoltaic system is presented. A new algorithm has been developed to determine configuration of facet mirrors in a NIDC. Analytical formulas were derived to analyze the optical performance of a NIDC and then compared with a simulated result obtained from a numerical method. Comprehensive analysis of optical performance via analytical method has been carried out based on facet dimension and focal distance of the concentrator with a total reflective area of 120 m2. The result shows that a facet dimension of 49.8 cm, focal distance of 8 m, and solar concentration ratio of 411.8 suns is the most optimized design for the lowest cost-per-output power, which is US$1.93 per watt.

Membrane distillation for milk concentration

NARCIS (Netherlands)

Moejes, S.N.; Romero Guzman, Maria; Hanemaaijer, J.H.; Barrera, K.H.; Feenstra, L.; Boxtel, van A.J.B.

2015-01-01

Membrane distillation is an emerging technology to concentrate liquid products while producing high quality water as permeate. Application for desalination has been studied extensively the past years, but membrane distillation has also potential to produce concentrated food products like

A discussion about maximum uranium concentration in digestion solution of U3O8 type uranium ore concentrate

International Nuclear Information System (INIS)

Xia Dechang; Liu Chao

2012-01-01

On the basis of discussing the influence of single factor on maximum uranium concentration in digestion solution,the influence degree of some factors such as U content, H 2 O content, mass ratio of P and U was compared and analyzed. The results indicate that the relationship between U content and maximum uranium concentration in digestion solution was direct ratio, while the U content increases by 1%, the maximum uranium concentration in digestion solution increases by 4.8%-5.7%. The relationship between H 2 O content and maximum uranium concentration in digestion solution was inverse ratio, the maximum uranium concentration in digestion solution decreases by 46.1-55.2 g/L while H 2 O content increases by 1%. The relationship between mass ratio of P and U and maximum uranium concentration in digestion solution was inverse ratio, the maximum uranium concentration in digestion solution decreases by 116.0-181.0 g/L while the mass ratio of P and U increase 0.1%. When U content equals 62.5% and the influence of mass ratio of P and U is no considered, the maximum uranium concentration in digestion solution equals 1 578 g/L; while mass ratio of P and U equals 0.35%, the maximum uranium concentration decreases to 716 g/L, the decreased rate is 54.6%, so the mass ratio of P and U in U 3 O 8 type uranium ore concentrate is the main controlling factor. (authors)

Imprint of the Sun on the Solar Wind

Science.gov (United States)

Woo, R.; Habbal, S. R.

1998-01-01

Observations of the inner corona in polarized brightness by the Mauna Loa MkIII K-coronameter and soft X-ray by Yohkoh of the inner corona are combined with Ulysses radio occultation measurements of the solar wind to demonstrate that the signature of active regions and bright points is present in the heliocentric distance range of 10-30 Ro.

Industrialisation et concentration urbaine

OpenAIRE

Kamal , Abdelhak

2010-01-01

The aim of this thesis is to analyze the determinants of the urban concentration and their effect at different levels of development. The empirical analysis focuses on the developing countries over the period 1950-2000 grouped by level of per capita income. The results confirm the existence of specific trajectories of urbanization rate and urban primacy which differs meaningfully according to the stage of development considered. Certain factors encourage urbanization and its concentration in ...

Simulation and development of a multi-leg homogeniser concentrating assembly for concentrated photovoltaic (CPV) system with electrical rating analysis

KAUST Repository

Burhan, Muhammad

2016-03-09

Concentrated photovoltaic (CPV) system utilizing multi-junction solar cells, is the main focus for current research, offering highest efficiency among all photovoltaic systems. The main aspect of CPV system is the design and performance of concentrating assembly, as it determines the performance of whole CPV system. However, the conventional design of CPV concentrating assembly dedicates one concentrator for each solar cell, in which single concentrator is capable to concentrate solar radiation onto single solar cell. This paper proposes a novel concentrating assembly for CPV system, which is designed to concentrate solar radiation onto four multi-junction solar cells with a single set of concentrators. The proposed design not only can reduce the number of concentrators and assembly efforts for CPV systems, but also achieved an acceptance angle of 1°. In this paper, the proposed multi-leg homogeniser CPV concentrating assembly is designed, developed, experimentally tested and verified through ray tracing simulation. The paper also discuss the development of mini, precise and accurate but cost effective two axis solar tracker for CPV system, which can be installed at any location even at rooftop of residential buildings, unlike conventional large scale CPV systems. Moreover, through the electrical rating analysis of the developed CPV system, its performance can be accurately estimated in any region. © 2016 Elsevier Ltd. All rights reserved.

Simulation and development of a multi-leg homogeniser concentrating assembly for concentrated photovoltaic (CPV) system with electrical rating analysis

KAUST Repository

Burhan, Muhammad; Chua, Kian Jon Ernest; Ng, Kim Choon

2016-01-01

Concentrated photovoltaic (CPV) system utilizing multi-junction solar cells, is the main focus for current research, offering highest efficiency among all photovoltaic systems. The main aspect of CPV system is the design and performance of concentrating assembly, as it determines the performance of whole CPV system. However, the conventional design of CPV concentrating assembly dedicates one concentrator for each solar cell, in which single concentrator is capable to concentrate solar radiation onto single solar cell. This paper proposes a novel concentrating assembly for CPV system, which is designed to concentrate solar radiation onto four multi-junction solar cells with a single set of concentrators. The proposed design not only can reduce the number of concentrators and assembly efforts for CPV systems, but also achieved an acceptance angle of 1°. In this paper, the proposed multi-leg homogeniser CPV concentrating assembly is designed, developed, experimentally tested and verified through ray tracing simulation. The paper also discuss the development of mini, precise and accurate but cost effective two axis solar tracker for CPV system, which can be installed at any location even at rooftop of residential buildings, unlike conventional large scale CPV systems. Moreover, through the electrical rating analysis of the developed CPV system, its performance can be accurately estimated in any region. © 2016 Elsevier Ltd. All rights reserved.

Concentrating Solar Power Projects - Planta Solar 20 | Concentrating Solar

Science.gov (United States)

Power | NREL 20 This page provides information on Planta Solar 20, a concentrating solar power Solar's Planta Solar 20 (PS20) is a 20-megawatt power tower plant being constructed next to the PS10 tower and increasing incident solar radiation capture will increase net electrical power output by 10

Nonimaging concentrators for diode-pumped slab lasers

Science.gov (United States)

Lacovara, Philip; Gleckman, Philip L.; Holman, Robert L.; Winston, Roland

1991-10-01

Diode-pumped slab lasers require concentrators for high-average power operation. We detail the properties of diode lasers and slab lasers which set the concentration requirements and the concentrator design methodologies that are used, and describe some concentrator designs used in high-average power slab lasers at Lincoln Laboratory.

Concentration factors for fish

International Nuclear Information System (INIS)

Feldt, W.; Lauer, R.; Melzer, M.; Siebert, W.

1978-01-01

Concentration factors are defined as operators allowing to calculate the specific activity of fish meat from a given concentration of an element in the water. This parameter depends among others from the content of stable isotopes and homologues in the different waters. If this parameter is reasonably to be used for model calculations it must be referred to water with all of its content substances, these calculations also being based on this type of 'water'. (orig.) [de

FK concentrator outdoor measurements

OpenAIRE

Hernández Sanz, Maikel; Vilaplana, J., J.; Benitez Gimenez, Pablo; Mohedano,, Rubén; Zamora Herranz, Pablo; Miñano Dominguez, Juan Carlos; Mendes Lopes, Joao

2013-01-01

The FK is a two-stage optical concentrator for CPV, composed by a Fresnel lens working as POE and a refractive element working as SOE. Both elements perform Köhler integration, for uniform irradiance purposes. The FK has demonstrated that compares very well with other Fresnel-based concentrator optics. Recent on-sun measurements carried out on an FK mono-module prototype have already shown outstanding results, achieving electrical efficiencies over 34%. Further optimization of optical design ...

A point focusing double parabolic trough concentrator

Energy Technology Data Exchange (ETDEWEB)

Murphree, Quincy C. [Kentucky Mountain Bible College, Vancleve, KY (United States)

2001-07-01

This article shows that a point focusing solar concentrator can be made from two reflective parabolic troughs, a primary and a secondary, by orienting their longitudinal axes in perpendicular directions and separating them by the difference of their focal lengths along the optical axis. This offers a new alternative to the conventional 3-D paraboloidal concentrator permitting more flexibility in designs for applications requiring high concentrations. Both advantages and disadvantages are discussed. The intensity concentration ratio distribution is calculated in the focal plane and has elliptically shaped contours due to the inherent compensation of errant rays by the concave secondary. The ratio of the major to minor axes was 2.61 for the case considered, resulting in a concentration {approx}2.61 times that of a comparable concentrator without the compensation afforded by a concave secondary. Still, geometrical constraints limit the concentration to about 2000 suns for mirror quality errors of 5 mr. Optimisation of the compensation effect holds potential for improved performance for other concentrator designs. Finally, the functional dependence of the peak concentration and shading factor upon design parameters are presented. (Author)

Tank waste concentration mechanism study

International Nuclear Information System (INIS)

Pan, L.C.; Johnson, L.J.

1994-09-01

This study determines whether the existing 242-A Evaporator should continue to be used to concentrate the Hanford Site radioactive liquid tank wastes or be replaced by an alternative waste concentration process. Using the same philosophy, the study also determines what the waste concentration mechanism should be for the future TWRS program. Excess water from liquid DST waste should be removed to reduce the volume of waste feed for pretreatment, immobilization, and to free up storage capacity in existing tanks to support interim stabilization of SSTS, terminal cleanout of excess facilities, and other site remediation activities

concentrate ratio and rumen ammonia concentration on in situ

African Journals Online (AJOL)

The aim of this experiment was to distinguish between the effects of dietary roughage: concentrate ratio and rumen ammonia ... several factors which include the potential rate and extent of degradation of the test feedstuff and the prevailing rate of ... diet effects have be,en designed to examine either the influence of dietary ...

Continuous measurements of outdoor radon concentrations

International Nuclear Information System (INIS)

Iida, T.; Ikebe, Y.; Suzuki, K.; Ueno, K.; Komura, K.; Kato, I.; Jin Yihe

1993-01-01

The authors studied and developed an electrostatic 222 Rn monitor and have measured continuously outdoor radon ( 222 Rn) concentrations at Nagoya University since 1985. Four 222 Rn monitors were newly constructed to measure outdoor 222 Rn concentrations at other locations. The 222 Rn concentrations at Nagoya and Kasugai show a clear diurnal variation in autumn, and a seasonal pattern of a spring-summer minimum and a autumn-winter maximum. The results at Toki are the same pattern as that at Nagoya except spring. The concentrations at Kanazawa show a slight seasonal variation. A clear diurnal variation is observed in summer. (4 figs.)

The concentration of iodine in horse serum and its relationship with thyroxin concentration by geological difference.

Science.gov (United States)

Mochizuki, Mariko; Hayakawa, Noriyuki; Minowa, Fumiko; Saito, Akihiro; Ishioka, Katsumi; Ueda, Fukiko; Okubo, Kimihiro; Tazaki, Hiroyuki

2016-04-01

In this study, iodine and thyroxin (T4) concentrations in the serum of 69 horses were investigated. Higher iodine concentrations were obtained from the horses housed in Chiba Prefecture. In contrast, T4 concentrations of horses at Shizuoka Prefecture were higher than those of horses at Chiba Prefecture. There was a significant correlation (r = 0.643, P geological differences. It was thought that equine serum is a useful sample for monitoring.

Radon concentration in The Netherlands

International Nuclear Information System (INIS)

Meijer, R.J. de; Put, L.W.; Veldhuizen, A.

1986-02-01

In 1000 dwellings, which can be assumed to be an reasonable representation of the average Dutch dwellings, time averaged radon concentrations, radon daughter concentrations and gamma-exposure tempi are determined during a year with passive dosemeters. They are also determined outdoor at circa 200 measure points. (Auth.)

Radon in indoor concentrations and indoor concentrations of metal dust particles in museums and other public buildings.

Science.gov (United States)

Carneiro, G L; Braz, D; de Jesus, E F; Santos, S M; Cardoso, K; Hecht, A A; Dias da Cunha, Moore K

2013-06-01

The aim of this study was to evaluate the public and occupational exposure to radon and metal-bearing particles in museums and public buildings located in the city of Rio de Janeiro, Brazil. For this study, four buildings were selected: two historic buildings, which currently house an art gallery and an art museum; and two modern buildings, a chapel and a club. Integrated radon concentration measurements were performed using passive radon detectors with solid state nuclear track detector-type Lexan used as nuclear track detector. Air samplers with a cyclone were used to collect the airborne particle samples that were analyzed by the particle-induced X-ray emission technique. The average unattached-radon concentrations in indoor air in the buildings were above 40 Bq/m(3), with the exception of Building D as measured in 2009. The average radon concentrations in indoor air in the four buildings in 2009 were below the recommended reference level by World Health Organization (100 Bq/m(3)); however, in 2011, the average concentrations of radon in Buildings A and C were above this level, though lower than 300 Bq/m(3). The average concentrations of unattached radon were lower than 148 Bq/m(3) (4pCi/L), the USEPA level recommended to take action to reduce the concentrations of radon in indoor air. The unattached-radon average concentrations were also lower than the value recommended by the European Union for new houses. As the unattached-radon concentrations were below the international level recommended to take action to reduce the radon concentration in air, it was concluded that during the period of sampling, there was low risk to human health due to the inhalation of unattached radon in these four buildings.

Solar concentrators. Concentradores solares

Energy Technology Data Exchange (ETDEWEB)

Almanza, R.; Valdes, A.; Lopez, S.

1981-06-01

This paper presents different types of geometries used in concentrators. Some comments are made on the theoretical and experimental analysis necessary to evaluate the geometries and on the type of laboratory equipment needed to obtain experimental data. At the end of the report a description of how to build parabolic trough mirrors is made. The experience gained by the authors, who have been working in this subject for the past five years, is summarized, showing some of the problems related with such concentrators.

Radon concentration in greehouses of Aomori Prefecture

International Nuclear Information System (INIS)

Iyogi, Takashi; Hisamatsu, Shun'ichi; Inaba, Jiro

2001-01-01

222 Rn causes a significant part of natural radiation dose to the general population. We previously surveyed 222 Rn concentrations in dwellings, and indoor and outdoor workplaces in Aomori Prefecture, and found geometric mean concentrations of 13, 22 and 4.4 Bq m -3 , respectively. The annual radiation dose rate of 4.3 mSv y -1 was estimated for people in the prefecture from these data. Since 222 Rn in the environment mainly originates from 226 Ra in the soil, that in cave is known to be higher than that in ordinary environments such as in buildings. Greenhouses are a possible place with high 222 Rn concentration, because of the soil exposed inside. However, the 222 Rn concentration in greenhouses has not yet been reported. We surveyed 222 Rn concentration in greenhouses of Aomori Prefecture. The 222 Rn concentration in 24 greenhouses at six locations in the prefecture were measured for approximately one year with passive Rn detectors using a polycarbonate film for counting α-rays, which could separate concentrations of 222 Rn from 220 Rn. Measurements of 222 Rn concentration and working level for one week carried out with active detectors to get equilibrium factors and the ratio of 222 Rn concentration in working time to non-working time in selected greenhouses. The geometric mean of 222 Rn concentrations in greenhouses was 13 Bq m -3 , and similar to that in dwellings. Significant seasonal variation was observed in 222 Rn concentrations. The geometric mean in June to September was 5.5 Bq m -3 , which was similar to that outside the greenhouses, while that in January to March was 19.5 Bq m -3 . These results showed that the 222 Rn concentration in greenhouses was comparable to that in dwellings. (author)

School concentration and school travel

NARCIS (Netherlands)

De Boer, E.

2010-01-01

The purpose of the research as described in this Doctor’s thesis is twofold. Firstly it is to define in how far Dutch facilities for primary and secondary education were subjected to spatial concentration during recent decades. Secondly it is intended to assess what this concentration implied for

Interstitial adenosine concentration is increased by dipyridamole

International Nuclear Information System (INIS)

Gorman, M.W.; Wangler, R.D.; DeWitt, D.F.; Wang, C.Y.; Bassingthwaighte, J.B.; Sparks, H.V.

1986-01-01

The authors used the multiple indicator dilution technique to observe the capillary transport of adenosine (ADO) in isolated guinea pig hearts. Radiolabelled albumin, sucrose and ADO were injected on the arterial side and measured in venous samples collected during the following 20 seconds. Transport parameters calculated from these data include permeability-surface area products (PS) for transendothelial diffusion, endothelial cell (EC) uptake at the lumenal and ablumenal membranes, and EC metabolism. With simultaneous measurements of arterial and venous ADO concentrations and flow, the authors calculated the steady-state interstitial fluid (ISF) ADO concentration. Under control conditions the venous ADO concentration was 7.1 +/- 2.8 nM. The calculated ISF concentration depends on whether they assume the venous ADO comes from the ISF, or directly from ECs. These ISF concentrations are 25 +/- 12 nM and 9.8 +/- 4.0 nM, respectively. During dipyridamole infusion (10 uM) the EC transport parameters became nearly zero. Venous and ISF ADO concentrations increased to 33 +/- 8.9 nM and 169 +/- 42 nM, respectively. The authors conclude that the ISF ADO concentration is 1.5-4 fold higher than the venous concentration at rest, and the ISF concentration increases greatly with dipyridamole

Lime, agent to uranium concentration; La chaux comme agent de concentration de l'uranium

Energy Technology Data Exchange (ETDEWEB)

Mouret, P; Le Bris, J; Kremer, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Gautier, R [Etablissement Kuhlmann, Service d' Etudes et de Pilotages Industriels (France)

1958-07-01

Choice of the process according to health requirements. Description of the process: dissolution of uranium by sulfuric leaching of ores, precipitation of uranium by lime, re-dissolution of the concentrate with nitric ions, purification by T.B.P. finally resulting in pure uranyl nitrate solution containing 400 g/litre. (author)Fren. [French] Les raisons du choix du procede en fonction des imperatifs d'hygiene, sont exposees ainsi que le procede qui consiste en une dissolution de l'uranium des minerais par lixiviation sulfurique, precipitation de l'uranium par la chaux et redissolution du concentre en presence d'ions nitriques, purification par le T.B.P. et obtention d'un concentre final de nitrate d'uranyle pur a 400 g/litre. (auteur)

Atmospheric relative concentrations in building wakes

International Nuclear Information System (INIS)

Ramsdell, J.V. Jr.; Simonen, C.A.; Smyth, S.B.

1995-05-01

This report documents the ARCON95 computer code developed for the U.S. Nuclear Regulatory Commission Office of Nuclear Regulatory Research for use in control room habitability assessments. The document includes a user's guide to the code, a description of the technical basis for the code, and a programmer's guide to the code. The ARCON95 code uses hourly meteorological data and recently developed methods for estimating dispersion in the vicinity of buildings to calculate relative concentrations at control room air intakes that would be exceeded no more five percent of the time. These concentrations are calculated for averaging periods ranging from one hour to 30 days in duration. Relative concentrations calculated by ARCON95 are significantly lower than concentrations calculated using the currently accepted procedure when winds are less than two meters per second. For higher wind speeds, ARCON95 calculates about the same concentrations as the current procedure

Maximum permissible concentrations and negligible concentrations for antifouling substances. Irgarol 1051, dichlofluanid, ziram, chlorothalonil and TCMTB

NARCIS (Netherlands)

Wezel AP van; Vlaardingen P van; CSR

2001-01-01

This report presents maximum permissible concentrations and negligible concentrations that have been derived for various antifouling substances used as substitutes for TBT. Included here are Irgarol 1051, dichlofluanide, ziram, chlorothalonil and TCMTB.

Concentrated Differential Privacy

OpenAIRE

Dwork, Cynthia; Rothblum, Guy N.

2016-01-01

We introduce Concentrated Differential Privacy, a relaxation of Differential Privacy enjoying better accuracy than both pure differential privacy and its popular "(epsilon,delta)" relaxation without compromising on cumulative privacy loss over multiple computations.

Urea concentration in sheep’s milk

Directory of Open Access Journals (Sweden)

Jasmina Havranek

2009-03-01

Full Text Available Determining urea concentration in milk is a useful indicator for controlling supply of proteins to organisms, as well as the relationship of energy and protein in the food, thus it is finding more and more ways of practical use. The concentration of urea in milk, along with the feeding process, is influenced by a number of other factors such as: breed, stage and sequence of lactation, body mass, daily production and chemical structure of milk, number of somatic cells, season, milking.The goal of the research was to establish the influence of the breed (Island of Krk, East Frisian, lactation stage (beginning, middle and the end and the herd (3 to the concentration of urea in milk during lactation.For each breed there has been established daily quantity of milk, protein share and the concentration of urea in milk.Statistical analysis of data was conducted by using General Linear Models procedure, SAS program system (1999.The breed of sheep considerably (P<0.001 influenced daily quantity of milk, protein share and the concentration of urea in the milk.East Frisian sheep produced on average almost double the daily quantities of milk (1070 mL compared to the Krk sheep (588 mL.Protein share and the urea concentration in Krk sheep milk were higher (5.99 % and 35.97 mg/100 mL then in the milk of East Frisian sheep (5.12 % and 33.31 mg/100 mL.For both breeds the significant influence of lactation stage to the daily milk quantity has been established (0.001, that is also for the urea concentration in the milk of Krk sheep (0.001, as well as protein share in the milk of East Frisian sheep (0.001.Herd influence significantly affected daily milk quantities (0.001 and concentration of urea in the milk (0.05.The defining of the urea concentration in sheep milk should be occasionally carried out in the Republic of Croatia to establish the standard physiological values typical for the particular sheep breed.

Effects of ambient oxygen concentration on soot temperature and concentration for biodiesel and diesel spray combustion

KAUST Repository

Zhang, Ji

2015-06-01

Ambient oxygen concentration, a key variable directly related to exhaust gas recirculation (EGR) levels in diesel engines, plays a significant role in particulate matter (PM) and nitrogen oxides (NOx) emissions. The utilization of biodiesel in diesel engines has been investigated over the last decades for its renewable characteristics and lower emissions compared to diesel. In an earlier work, we demonstrated that the soot temperature and concentration of biodiesel were lower than diesel under regular diesel engine conditions without EGR. Soot concentration was quantified by a parameter called KL factor. As a continuous effort, this paper presents an experimental investigation of the ambient oxygen concentration on soot temperature and KL factor during biodiesel and diesel spray combustion. The experiment was implemented in a constant volume chamber system, where the ambient oxygen concentration varied from 21 to 10% and the ambient temperature was kept to 1,000 K. A high speed two-color pyrometry technique was used to measure transient soot temperature and the KL factor of the spray flame. The soot temperature of biodiesel is found to be lower than that of diesel under the same conditions, which follows the same trend from our previous results found when the ambient temperature changes to 21% oxygen conditions. A reduction in ambient oxygen concentration generally reduces the soot temperature for both fuels. However, this is a complicated effect on soot processes as the change of oxygen concentration greatly affects the balance between soot formation and oxidation. The KL factor is observed to be the highest at 12% O2 for diesel and 18% O2 for biodiesel, respectively. On the other hand, the 10% O2 condition shows the lowest KL factor for both fuels. These results can provide quantitative experimental evidences to optimize the ambient oxygen concentration for diesel engines using different fuels for better emissions characteristics. © 2014 American Society of

Soil dioxin concentrations in Baden-Wuerttemberg

International Nuclear Information System (INIS)

Wolf, D.

1993-01-01

Soil dioxin levels in Baden-Wuerttemberg are generally low. Where high dioxin concentrations have been reported like in Rastatt, Rheinfelden, Crailsheim-Maulach and Eppingen these phenomena are local. Already at less than 100 metres distance, drastically lower concentrations are measured. At 1500 to 2000 metres distance the values are back to the ordinary background level. A programme for detecting sources of emission in the entire state revealed no further sites of heavy contamination. For this assessment of soil dioxin concentrations in Baden-Wuerttemberg 1275 soil samples were used, which is a vast amount also in comparison with nation-wide surveys. The average dioxin content in farmland is about 1 ng I-TEq/kg m T . Soil dioxin concentrations are the higher the greater the density of settlements and industry. In cities they are about three to five times higher than the ubiquitous background concentration. The highest concentrations measured were 5-20 ng I-TE/kg in garden soils in cities. Sewage sludge may be a significant source of dioxin contamination for farmland, far beyond the ubiquitous background concentration. Automobile exhaust gas caused higher soil contamination within 10 m along both sides of the roads as a function of traffic. Because scavengers in gasoline are now prohibited and catalysts are becoming more and more common the rate of additional dioxin and furan contamination due to traffic will decrease. Currently, traffic-related emissions in Baden-Wuerttemberg are well below 2 g I-TEq. (orig./EF) [de

Comparison of two-concentration with multi-concentration linear regressions: Retrospective data analysis of multiple regulated LC-MS bioanalytical projects.

Science.gov (United States)

Musuku, Adrien; Tan, Aimin; Awaiye, Kayode; Trabelsi, Fethi

2013-09-01

Linear calibration is usually performed using eight to ten calibration concentration levels in regulated LC-MS bioanalysis because a minimum of six are specified in regulatory guidelines. However, we have previously reported that two-concentration linear calibration is as reliable as or even better than using multiple concentrations. The purpose of this research is to compare two-concentration with multiple-concentration linear calibration through retrospective data analysis of multiple bioanalytical projects that were conducted in an independent regulated bioanalytical laboratory. A total of 12 bioanalytical projects were randomly selected: two validations and two studies for each of the three most commonly used types of sample extraction methods (protein precipitation, liquid-liquid extraction, solid-phase extraction). When the existing data were retrospectively linearly regressed using only the lowest and the highest concentration levels, no extra batch failure/QC rejection was observed and the differences in accuracy and precision between the original multi-concentration regression and the new two-concentration linear regression are negligible. Specifically, the differences in overall mean apparent bias (square root of mean individual bias squares) are within the ranges of -0.3% to 0.7% and 0.1-0.7% for the validations and studies, respectively. The differences in mean QC concentrations are within the ranges of -0.6% to 1.8% and -0.8% to 2.5% for the validations and studies, respectively. The differences in %CV are within the ranges of -0.7% to 0.9% and -0.3% to 0.6% for the validations and studies, respectively. The average differences in study sample concentrations are within the range of -0.8% to 2.3%. With two-concentration linear regression, an average of 13% of time and cost could have been saved for each batch together with 53% of saving in the lead-in for each project (the preparation of working standard solutions, spiking, and aliquoting). Furthermore

Revealing source signatures in ambient BTEX concentrations

International Nuclear Information System (INIS)

Zalel, Amir; Yuval; Broday, David M.

2008-01-01

Management of ambient concentrations of Volatile Organic Compounds (VOCs) is essential for maintaining low ozone levels in urban areas where its formation is under a VOC-limited regime. The significant decrease in traffic-induced VOC emissions in many developed countries resulted in relatively comparable shares of traffic and non-traffic VOC emissions in urban airsheds. A key step for urban air quality management is allocating ambient VOC concentrations to their pertinent sources. This study presents an approach that can aid in identifying sources that contribute to observed BTEX concentrations in areas characterized by low BTEX concentrations, where traditional source apportionment techniques are not useful. Analysis of seasonal and diurnal variations of ambient BTEX concentrations from two monitoring stations located in distinct areas reveal the possibility to identify source categories. Specifically, the varying oxidation rates of airborne BTEX compounds are used to allocate contributions of traffic emissions and evaporative sources to observed BTEX concentrations. - BTEX sources are identified from temporal variations of ambient concentration

Universal distortion-free entanglement concentration

International Nuclear Information System (INIS)

Matsumoto, Keiji; Hayashi, Masahito

2007-01-01

We propose a new protocol of universal entanglement concentration, which converts many copies of an unknown pure state to an exact maximally entangled state. The yield of the protocol, which is outputted as a classical information, is probabilistic, and achieves the entropy rate with high probability, just as nonuniversal entanglement concentration protocols do

Availability of food resources, distribution of invasive species, and conservation of a Hawaiian bird along a gradient of elevation

Science.gov (United States)

Banko, P.C.; Oboyski, P.T.; Slotterback, J.W.; Dougill, Steve J.; Goltz, Dan M.; Johnson, L.; Laut, M.E.; Murray, T.C.

2002-01-01

, resulted in Sophora resources being available to Loxioides throughout the year on the western slope of Mauna Kea. Sophora produced flowers and pods more seasonally where gradients of elevation were short; thus, resources were available less consistently. In contrast, Myoporum produced flowers and fruits with little variation with respect to season or elevation. The availability of important insect prey of Loxioides was also related to elevation, in part because threats to Lepidoptera larvae from parasitic wasps were generally less at higher elevations. Threats to insect prey from predatory ants was also less at higher elevations but the abundance of predatory wasps was not related to elevation. Several weeds that pose the most serious threats to Loxioides habitat were more abundant at mid and low elevations, and alien grass cover was somewhat greater at mid elevation, thereby increasing fire risks in the centre of Loxioides habitat. Predatory mammals, in particular Felis catus Linnaeus, were common throughout the subalpine forest of Mauna Kea. However, Rattus rattus Linnaeus was rare, especially at higher elevations, whereas Mus musculus Linnaeus was more abundant at lower elevations. Main conclusions: Loxioides are concentrated in habitat that is distributed along a substantial gradient of elevation at least in part because food is available throughout the year and threats to food resources are less concentrated. To recover Loxioides elsewhere in its former range, habitats must be restored and alien threats reduced along extensive elevation gradients. Conservation along environmental gradients will likely benefit other Hawaiian birds that track the availability of food across landscapes or that have been stranded in the higher portions of their original ranges because of the greater impacts of alien diseases, predators, food competitors, and habitat stressors at lower elevations.

Nonimaging optics in luminescent solar concentration.

Science.gov (United States)

Markman, B D; Ranade, R R; Giebink, N C

2012-09-10

Light trapped within luminescent solar concentrators (LSCs) is naturally limited in angular extent by the total internal reflection critical angle, θcrit, and hence the principles of nonimaging optics can be leveraged to increase LSC concentration ratio by appropriately reshaping the edges. Here, we use rigorous ray-tracing simulations to explore the potential of this concept for realistic LSCs with compound parabolic concentrator (CPC)-tapered edges and show that, when applied to a single edge, the concentration ratio is increased by 23% while maintaining >90% of the original LSC optical efficiency. Importantly, we find that CPC-tapering all of the edges enables a significantly greater intensity enhancement up to 35% at >90% of the original optical efficiency, effectively enabling two-dimensional concentration through a cooperative, ray-recycling effect in which rays rejected by one CPC are accepted by another. These results open up a significant opportunity to improve LSC performance at virtually no added manufacturing cost by incorporating nonimaging optics into their design.

Chromium concentrations in ruminant feed ingredients.

Science.gov (United States)

Spears, J W; Lloyd, K E; Krafka, K

2017-05-01

Chromium (Cr), in the form of Cr propionate, has been permitted for supplementation to cattle diets in the United States at levels up to 0.50 mg of Cr/kg of DM since 2009. Little is known regarding Cr concentrations naturally present in practical feed ingredients. The present study was conducted to determine Cr concentrations in feed ingredients commonly fed to ruminants. Feed ingredients were collected from dairy farms, feed mills, grain bins, and university research farms. Mean Cr concentrations in whole cereal grains ranged from 0.025 mg/kg of DM for oats to 0.041 mg/kg of DM for wheat. Grinding whole samples of corn, soybeans, and wheat through a stainless steel Wiley mill screen greatly increased analyzed Cr concentrations. Harvested forages had greater Cr concentrations than concentrates, and alfalfa hay or haylage had greater Cr concentrations than grass hay or corn silage. Chromium in alfalfa hay or haylage (n = 13) averaged 0.522 mg/kg of DM, with a range of 0.199 to 0.889 mg/kg of DM. Corn silage (n = 21) averaged 0.220 mg of Cr/kg of DM with a range of 0.105 to 0.441 mg of Cr/kg of DM. By-product feeds ranged from 0.040 mg of Cr/kg of DM for cottonseed hulls to 1.222 mg of Cr/kg of DM for beet pulp. Of the feed ingredients analyzed, feed grade phosphate sources had the greatest Cr concentration (135.0 mg/kg). Most ruminant feedstuffs and feed ingredients had less than 0.50 mg of Cr/kg of DM. Much of the analyzed total Cr in feed ingredients appears to be due to Cr contamination from soil or metal contact during harvesting, processing, or both. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Comparison of Plasma, Saliva, and Hair Levetiracetam Concentrations.

Science.gov (United States)

Karaś-Ruszczyk, Katarzyna; Kuczyńska, Julita; Sienkiewicz-Jarosz, Halina; Kurkowska-Jastrzębska, Iwona; Bienkowski, Przemyslaw; Restel, Magdalena; Samochowiec, Jerzy; Mierzejewski, Pawel

2017-06-01

Previous findings revealed high correlations between serum/plasma and saliva levetiracetam concentrations, indicating saliva as an alternative matrix for monitoring levetiracetam therapy. Levetiracetam concentration in the hair, which could reflect long-term drug exposure and patients' compliance, has not been systematically tested, as yet. The aim of this study was to determine the correlation between plasma, saliva, and hair levetiracetam concentrations in 47 patients with epilepsy. Plasma, saliva, and hair levetiracetam concentrations were measured by liquid chromatography-tandem mass spectrometry with positive ionization. Levetiracetam saliva and plasma concentrations were highly correlated (r = 0.93). Plasma concentrations were not influenced by sex, age, and other concomitant antiepileptic drugs. Levetiracetam hair concentrations correlated with plasma concentrations (r = 0.36) but not daily dose (mg/kg). Drug hair concentrations were not influenced by hair color or treatment (dyed). The results tend to indicate that saliva may be a reliable alternative to plasma for monitoring levetiracetam concentrations. Levetiracetam can also be detected in human hair.

Concentric retinitis pigmentosa: clinicopathologic correlations.

Science.gov (United States)

Milam, A H; De Castro, E B; Smith, J E; Tang, W X; John, S K; Gorin, M B; Stone, E M; Aguirre, G D; Jacobson, S G

2001-10-01

Progressive concentric (centripetal) loss of vision is one pattern of visual field loss in retinitis pigmentosa. This study provides the first clinicopathologic correlations for this form of retinitis pigmentosa. A family with autosomal dominant concentric retinitis pigmentosa was examined clinically and with visual function tests. A post-mortem eye of an affected 94 year old family member was processed for histopathology and immunocytochemistry with retinal cell specific antibodies. Unrelated simplex/multiplex patients with concentric retinitis pigmentosa were also examined. Affected family members of the eye donor and patients from the other families had prominent peripheral pigmentary retinopathy with more normal appearing central retina, good visual acuity, concentric field loss, normal or near normal rod and cone sensitivity within the preserved visual field, and reduced rod and cone electroretinograms. The eye donor, at age 90, had good acuity and function in a central island. Grossly, the central region of the donor retina appeared thinned but otherwise normal, while the far periphery contained heavy bone spicule pigment. Microscopically the central retina showed photoreceptor outer segment shortening and some photoreceptor cell loss. The mid periphery had a sharp line of demarcation where more central photoreceptors were near normal except for very short outer segments and peripheral photoreceptors were absent. Rods and cones showed abrupt loss of outer segments and cell death at this interface. It is concluded that concentric retinitis pigmentosa is a rare but recognizable phenotype with slowly progressive photoreceptor death from the far periphery toward the central retina. The disease is retina-wide but shows regional variation in severity of degeneration; photoreceptor death is severe in the peripheral retina with an abrupt edge between viable and degenerate photoreceptors. Peripheral to central gradients of unknown retinal molecule(s) may be defective

Photovoltaic applications of Compound Parabolic Concentrator (CPC)

Science.gov (United States)

Winston, R.

1975-01-01

The use of a compound parabolic concentrator as field collector, in conjunction with a primary focusing concentrator for photovoltaic applications is studied. The primary focusing concentrator can be a parabolic reflector, an array of Fresnel mirrors, a Fresnel lens or some other lens. Silicon solar cell grid structures are proposed that increase efficiency with concentration up to 10 suns. A ray tracing program has been developed to determine energy distribution at the exit of a compound parabolic concentrator. Projected total cost of a CPC/solar cell system will be between 4 and 5 times lower than for flat plate silicon cell arrays.

Concentration quenching in Nd-doped glasses

International Nuclear Information System (INIS)

Stokowski, S.E.; Cook, L.; Mueller, H.; Weber, M.J.

1984-01-01

Fluorescence from trivalent Nd in solids is unfortunately quenched by interactions between Nd ions. Thus, laser materials with high Nd concentrations have reduced efficiencies because of this self-quenching, also known as concentration quenching. Nd self-quenching in different crystals and glasses varies considerably. We are therefore investigating this effect in a large number of materials in an effort to: (1) find those materials with long Nd fluorescent lifetimes at high Nd concentrations; and (2) elucidate the basic mechanisms of quenching and how the material structure controls its magnitude. We have concentrated on Nd-doped glasses because they provide a rich variety of structures, albeit complicated by Nd site inhomogeneities, and are easily and quickly made

Preovulatory progesterone concentration associates significantly to follicle number and LH concentration but not to pregnancy rate

DEFF Research Database (Denmark)

Yding Andersen, Claus; Bungum, Leif; Nyboe Andersen, Anders

2011-01-01

Using data from a large prospective randomized controlled trial that evaluated the effect of recombinant LH (rLH)co-administration for ovarian stimulation, the present study assessed whether progesterone concentration on the day of human chorionic gonadotrophin (HCG) administration was associated...... with or without rLH administration from day 6 of stimulation. There was no significant association between the late-follicular-phase progesterone concentration and the clinical pregnancy rate. However, progesterone concentration was strongly associated with the number of follicles and retrieved oocytes. Late...

Oxygen Concentration Inside a Functioning Photosynthetic Cell

OpenAIRE

Kihara, Shigeharu; Hartzler, Daniel A.; Savikhin, Sergei

2014-01-01

The excess oxygen concentration in the photosynthetic membranes of functioning oxygenic photosynthetic cells was estimated using classical diffusion theory combined with experimental data on oxygen production rates of cyanobacterial cells. The excess oxygen concentration within the plesiomorphic cyanobacterium Gloeobactor violaceus is only 0.025 μM, or four orders of magnitude lower than the oxygen concentration in air-saturated water. Such a low concentration suggests that the first oxygenic...

A compact spectrum splitting concentrator for high concentration photovoltaics based on the dispersion of a lens

Science.gov (United States)

He, J.; Flowers, C. A.; Yao, Y.; Atwater, H. A.; Rockett, A. A.; Nuzzo, R. G.

2018-06-01

Photovoltaic devices used in conjunction with functional optical elements for light concentration and spectrum splitting are known to be a viable approach for highly efficient photovoltaics. Conventional designs employ discrete optical elements, each with the task of either performing optical concentration or separating the solar spectrum. In the present work, we examine the performance of a compact photovoltaic architecture in which a single lens plays a dual role as both a concentrator and a spectrum splitter, the latter made possible by exploiting its intrinsic dispersion. A four-terminal two-junction InGaP/GaAs device is prepared to validate the concept and illustrates pathways for improvements. A spectral separation in the visible range is demonstrated at the focal point of a plano-convex lens with a geometric concentration ratio of 1104X with respect to the InGaP subcell.

The Los Angeles TEAM Study: personal exposures, indoor-outdoor air concentrations, and breath concentrations of 25 volatile organic compounds.

Science.gov (United States)

Wallace, L; Nelson, W; Ziegenfus, R; Pellizzari, E; Michael, L; Whitmore, R; Zelon, H; Hartwell, T; Perritt, R; Westerdahl, D

1991-04-01

The U.S. Environmental Protection Agency and the California Air Resources Board studied the exposures of 51 residents of Los Angeles, California, to 25 volatile organic chemicals (VOCs) in air and drinking water in 1987. A major goal of the study was to measure personal, indoor, and outdoor air concentrations, and breath concentrations of VOCs in persons living in households that had previously been measured in 1984. Other goals were to confirm the marked day-night and seasonal differences observed in 1984; to determine room-to-room variability within homes; to determine source emission rates by measuring air exchange rates in each home; and to extend the coverage of chemicals by employing additional sampling and analysis methods. A total of 51 homes were visited in February of 1987, and 43 of these were revisited in July of 1987. The results confirmed previous TEAM Study findings of higher personal and indoor air concentrations than outdoor concentrations of all prevalent chemicals (except carbon tetrachloride); higher personal, indoor, and outdoor air concentrations in winter than in summer; and (in winter only) higher outdoor concentrations at night than in the daytime. New findings included the following: (1) room-to-room variability of 12-hour average concentrations was very small, indicating that a single monitor may be adequate for estimating indoor concentrations over this time span; (2) "whole-house" source emission rates were relatively constant during both seasons, with higher rates for odorous chemicals such as p-dichlorobenzene and limonene (often used in room air fresheners) than for other classes of chemicals; (3) breath concentrations measured during morning and evening were similar for most participants, suggesting the suitability of breath measurements for estimating exposure in the home; (4) limited data obtained on two additional chemicals-toluene and methylene chloride-indicated that both were prevalent at fairly high concentrations and that

Designing generalized conic concentrators for conventional optical systems

Science.gov (United States)

Eichhorn, W. L.

1985-01-01

Generalized nonimaging concentrators can be incorporated into conventional optical systems in situations where flux concentration rather than imaging is required. The parameters of the concentrator for maximum flux concentration depend on the design of the particular optical system under consideration. Rationale for determining the concentrator parameters is given for one particular optical system and the procedure used for calculation of these parameters is outlined. The calculations are done for three concentrators applicable to the optical system.

Nonimaging optical concentrators using graded-index dielectric.

Science.gov (United States)

Zitelli, M

2014-04-01

A new generation of inhomogeneous nonimaging optical concentrators is proposed, able to achieve simultaneously high optical efficiency and acceptance solid angle at a given geometrical concentration factor. General design methods are given, and concentrators are numerically investigated and optimized.

Concentrating Solar Power Projects - KaXu Solar One | Concentrating Solar

Science.gov (United States)

Power | NREL KaXu Solar One This page provides information on KaXu Solar One, a concentrating solar power (CSP) project, with data organized by background, parcipants and power plant configuration . Status Date: April 14, 2015 Project Overview Project Name: KaXu Solar One Country: South Africa Location

Uranium concentration monitor manual: 2300 system

International Nuclear Information System (INIS)

Russo, P.A.; Sprinkle, J.K. Jr.; Stephens, M.M.

1985-04-01

This manual describes the design, operation, and procedures for measurement control for the automated uranium concentration monitor on the 2300 solvent extraction system at the Oak Ridge Y-12 Plant. The nonintrusive monitor provides a near-real time readout of uranium concentration at two locations simultaneously in the solvent extraction system for process monitoring and control. Detectors installed at the top of the extraction column and at the bottom of the backwash column acquire spectra of gamma rays from the solvent extraction solutions in the columns. Pulse-height analysis of these spectra gives the concentration of uranium in the organic product of the extraction column and in the aqueous product of the solvent extraction system. The visual readouts of concentrations for process monitoring are updated every 2 min for both detection systems. Simultaneously, the concentration results are shipped to a remote computer that has been installed by Y-12 to demonstrate automatic control of the solvent extraction system based on input of near-real time process operation information. 8 refs., 13 figs., 4 tabs

Factors Affecting Tocopherol Concentrations in Soybean Seeds.

Science.gov (United States)

Carrera, Constanza S; Seguin, Philippe

2016-12-21

Soybean seeds contain several health-beneficial compounds, including tocopherols, which are used by the nutraceutical and functional food industries. Soybean tocopherol concentrations are, however, highly variable. Large differences observed in tocopherol concentrations among soybean genotypes together with the relatively simple biosynthetic pathway involving few genes support the feasibility of selecting for high-tocopherol soybean. Tocopherol concentrations are also highly influenced by environmental factors and field management. Temperature during seed filling and soil moisture appear to be the main factors affecting tocopherol concentrations; other factors such as soil fertility and solar radiation also affect concentrations and composition. Field management decisions including seeding date, row spacing, irrigation, and fertilization also affect tocopherols. Knowledge of factors affecting soybean tocopherols is essential to develop management strategies that will lead to the production of seeds with consistent target concentrations that will meet the needs of the nutraceutical and functional food industries.

Causality Between Urban Concentration and Environmental Quality

Directory of Open Access Journals (Sweden)

Amin Pujiati

2015-08-01

Full Text Available Population is concentrated in urban areas can cause the external diseconomies on environment if it exceeds the carrying capacity of the space and the urban economy. Otherwise the quality of the environment is getting better, led to the concentration of population in urban areas are increasingly high. This study aims to analyze the relationship of causality between the urban concentration and environmental quality in urban agglomeration areas. The data used in the study of secondary data obtained from the Central Bureau of statistics and the City Government from 2000 to 2013. The analytical method used is the Granger causality and descriptive. Granger causality study results showed no pattern of reciprocal causality, between urban concentration and the quality of the environment, but there unidirectional relationship between the urban concentration and environmental quality. This means that increasing urban concentration led to decreased environmental quality.

Concentrated loads on concrete

DEFF Research Database (Denmark)

Lorenzen, Karen Grøndahl; Nielsen, Mogens Peter

1997-01-01

This report deals with concentrated loads on concrete.A new upper bound solution in the axisymmetrical case of a point load in the center of the end face of a cylinder is developed.Based on previous work dealing with failure mechanisms and upper bound solutions, new approximate formulas are devel......This report deals with concentrated loads on concrete.A new upper bound solution in the axisymmetrical case of a point load in the center of the end face of a cylinder is developed.Based on previous work dealing with failure mechanisms and upper bound solutions, new approximate formulas...

Concentrator-solar-cell development

Science.gov (United States)

Grenon, L.

1982-07-01

A program is described which is a continuation of earlier programs for the development of high-efficiency, low-cost, silicon concentrator solar cells. The base-line process steps and process sequences identified in these earlier contracts were evaluated and specific processes reviewed. In particular, emphasis on the use of Czochralski-grown silicon wafers rather than float-zone wafers were examined. Additionally, a study of the trade-offs between textured and nontextured cells was initiated, and the limits within which the low-cost plated nickel copper metallization can be used in concentrator solar cell applications was identified.

Family-Concentrated Ownership in Chinese PLCs: Does Ownership Concentration Always Enhance Corporate Value?

Directory of Open Access Journals (Sweden)

Jin-Hui Luo

2014-02-01

Full Text Available In this paper we investigate the relationship between family ownership structure and corporate value across a sample of 1314 firm-year observations of China’s family publicly listed companies (PLCs, from 2004 to 2008. We find a significant inverse-U-shaped relationship between the controlling family’s ultimate cash-flow rights and corporate value; as measured by Tobin’s Q. That is, as family-ownership concentration increases, corporate value first increases and then decreases. This finding refreshes our understanding of the relationship between family-ownership concentration and corporate value in emerging economies such as found in China. We corroborate prior findings that when controlling families hold excess control over cash-flow rights, corporate value is significantly lowered, while multiple large shareholders structure is significantly associated with higher corporate value. In addition; board independence is found to significantly improve corporate value in the context of family-concentrated ownership. We also test for potential endogeneity between family ownership and corporate value and find our results to be robust.

Effects of concentrated sunlight on organic photovoltaics

DEFF Research Database (Denmark)

Tromholt, Thomas; Katz, Eugene A.; Hirsch, Baruch

2010-01-01

We report the effects of concentrated sunlight on key photovoltaic parameters and stability of organic photovoltaics (OPV). Sunlight collected and concentrated outdoors was focused into an optical fiber and delivered onto a 1 cm2 bulk-heterojunction cell. Sunlight concentration C was varied gradu...

Concentrated sunlight for organic solar cells

DEFF Research Database (Denmark)

Tromholt, Thomas

2010-01-01

. A high solar intensity study of inverted P3HT:PCBM solar cells is presented. Performance peak positions were found to be in the range of 1-5 suns, with smaller cells peaking at higher solar concentrations. Additionally, concentrated sunlight is demonstrated as a practical tool for accelerated stability...... were degraded resulting in acceleration factors in the range of 19-55. This shows that concentrated sunlight can be used as qualitatively to determine the lifetime of polymers under highly accelerated conditions....

Nonimaging solar concentrator with uniform irradiance

Science.gov (United States)

Winston, Roland; O'Gallagher, Joseph J.; Gee, Randy C.

2004-09-01

We report results of a study our group has undertaken under NREL/DOE auspices to design a solar concentrator with uniform irradiance on a planar target. This attribute is especially important for photovoltaic concentrators.

Intrapulmonary concentration of enrofloxacin in healthy calves

Science.gov (United States)

OTOMARU, Konosuke; HIRATA, Masaya; IKEDO, Tomonobu; HORINOUCHI, Chie; NOGUCHI, Michiko; ISHIKAWA, Shingo; NAGATA, Shun-ichi; HOBO, Seiji

2015-01-01

To determine the intrapulmonary concentration of enrofloxacin (ERFX) in calves, plasma, bronchoalveolar lavage fluid (BALF) and alveolar cells samples were obtained from clinically healthy calves. Four clinically healthy calves were administered a single dose of ERFX (5 mg/kg) by subcutaneous injection. Samples of plasma were obtained for each subjects at 0 (before administration), 1 and 2 hr after administration of ERFX. Samples of BALF were obtained from each subject at 0, 1 and 2 hr after administration of ERFX. This examination was conducted two times, one week apart. The mean EFRX concentrations in plasma at 1 and 2 hr after administration were l.23 and 1.29 µg/ml, respectively. The mean EFRX concentrations in pulmonary epithelial lining fluid (ELF) at 1 and 2 hr after administration 8.53 µg/ml and 9.42 µg/ml, respectively. The mean ERFX concentrations of alveolar cells in BALF at 1 and 2 hr after administration were 4.04 µg/ml and 5.19 µg/ml, respectively. These results suggest that the ERFX concentrations in ELF and alveolar cells concentrations in BALF at 1 and 2 hr after administration were higher than the plasma concentrations. PMID:26668174

The concentrations of uranium in marine organisms

Energy Technology Data Exchange (ETDEWEB)

Matsuba, Mitsue; Ishii, Toshiaki; Nakahara, Motokazu; Nakamura, Ryoichi; Watabe, Teruhisa; Hirano, Shigeki [National Inst. of Radiological Sciences, Hitachinaka, Ibaraki (Japan). Laboratory for Radioecology

2000-07-01

Determination of uranium in sixty-one species of marine organisms was carried out by inductively coupled plasma mass spectrometry to obtain concentration factors and to estimate the internal radiation dose. The concentrations of uranium in soft tissues of marine animals were ranged from 0.077 to 5040 ng/g wet wt. Especially, the branchial heart of cephalopod molluscs showed the specific accumulation of uranium. The concentration factor of the branchial heart of Octopus vulgaris, which indicated the highest value, was calculated to be about 1.6 x 10{sup 3}, comparing with that (3.1 ng/ml) in coastal seawaters of Japan. The concentrations of uranium in hard tissues of marine invertebrates such as clam and sea urchin were similar to those in soft tissues. In contrast, hard tissues like bone, scale, fin, etc. of fishes showed much higher concentrations of uranium than soft tissues like muscle. The concentrations of uranium of twenty-two species of algae were ranged from 2 to 310 ng/g wet wt. Particularly, the brown alga Undaria pinnatifida showed the highest value of the uranium content in the algae and its concentration factor was calculated to be 10{sup 2}. (author)

The concentrations of uranium in marine organisms

International Nuclear Information System (INIS)

Matsuba, Mitsue; Ishii, Toshiaki; Nakahara, Motokazu; Nakamura, Ryoichi; Watabe, Teruhisa; Hirano, Shigeki

2000-01-01

Determination of uranium in sixty-one species of marine organisms was carried out by inductively coupled plasma mass spectrometry to obtain concentration factors and to estimate the internal radiation dose. The concentrations of uranium in soft tissues of marine animals were ranged from 0.077 to 5040 ng/g wet wt. Especially, the branchial heart of cephalopod molluscs showed the specific accumulation of uranium. The concentration factor of the branchial heart of Octopus vulgaris, which indicated the highest value, was calculated to be about 1.6 x 10 3 , comparing with that (3.1 ng/ml) in coastal seawaters of Japan. The concentrations of uranium in hard tissues of marine invertebrates such as clam and sea urchin were similar to those in soft tissues. In contrast, hard tissues like bone, scale, fin, etc. of fishes showed much higher concentrations of uranium than soft tissues like muscle. The concentrations of uranium of twenty-two species of algae were ranged from 2 to 310 ng/g wet wt. Particularly, the brown alga Undaria pinnatifida showed the highest value of the uranium content in the algae and its concentration factor was calculated to be 10 2 . (author)

Zero-reabsorption doped-nanocrystal luminescent solar concentrators.

Science.gov (United States)

Erickson, Christian S; Bradshaw, Liam R; McDowall, Stephen; Gilbertson, John D; Gamelin, Daniel R; Patrick, David L

2014-04-22

Optical concentration can lower the cost of solar energy conversion by reducing photovoltaic cell area and increasing photovoltaic efficiency. Luminescent solar concentrators offer an attractive approach to combined spectral and spatial concentration of both specular and diffuse light without tracking, but they have been plagued by luminophore self-absorption losses when employed on practical size scales. Here, we introduce doped semiconductor nanocrystals as a new class of phosphors for use in luminescent solar concentrators. In proof-of-concept experiments, visibly transparent, ultraviolet-selective luminescent solar concentrators have been prepared using colloidal Mn(2+)-doped ZnSe nanocrystals that show no luminescence reabsorption. Optical quantum efficiencies of 37% are measured, yielding a maximum projected energy concentration of ∼6× and flux gain for a-Si photovoltaics of 15.6 in the large-area limit, for the first time bounded not by luminophore self-absorption but by the transparency of the waveguide itself. Future directions in the use of colloidal doped nanocrystals as robust, processable spectrum-shifting phosphors for luminescent solar concentration on the large scales required for practical application of this technology are discussed.

Process for treatment of pyrochlore concentrates

International Nuclear Information System (INIS)

Charlot, G.

1976-01-01

A continuous process is described for extraction of niobium, rare earths and thorium from niobium ore concentrates which includes digesting the ore with a hot solution containing 13 to 16 moles of sulphuric acid per liter, diluting the solution to a concentration of 10 to 13 moles of sulphuric acid per liter, separating the insolubles from the solution which includes alkaline earth sulphates and the sulphates of thorium and rare earths that are present, reducing titanium in solution to the trivalent state and diluting the solution to a concentration of 5 to 7 moles of sulphuric acid per liter, separating the precipitated niobium oxide and sulphates of thorium and rare earths, and then concentrating the resulting solution to the level desired for recycle to the digestion stage. 10 Claims, No Drawings

Illumination uniformity issue explored via two-stage solar concentrator system based on Fresnel lens and compound flat concentrator

International Nuclear Information System (INIS)

Yeh, Naichia

2016-01-01

This paper illustrates details about the solar radiation distribution on the target of a two-stage solar concentrator that combines the Fresnel lens (FL) and the compound flat concentrator (CFC). The paper starts with a review of some FL development milestones such as the two-stage systems and the comparisons of flat vs. curved lenses in addition to the most noteworthy FL-based solar energy application, concentration photovoltaic (CPV). Through the review of the FL based CPV and two-stage concentrators, this study leads to the development of an algorithm to explore the spectrum distribution insight on the receiver of a two-stage (FL plus CFC) solar concentration system. It established the potential for using a correctly positioned 2nd stage reflector of right dimension to selectively redirect the desired spectrum on the target area so as to enhance the concentration flux intensity and uniformity at the same time. The study also helped to chart out the approximate locations of certain spectrum segments on the FL's target area, which is useful for exploring the spectrum control mechanism via the Fresnel lenses. - Highlights: • Map out the approximate locations of spectrum segments on FL's focal area. • Use the 2nd stage reflector to selectively reflect the desired spectrum on target. • Explore the spectrum distribution insight on FL solar concentrators' target area.

Potassium concentration in bone of Beijing residents

International Nuclear Information System (INIS)

Lin Lianqing

1994-01-01

The author presents the measuring results of K concentration in bone ash samples of 65 residents in Beijing area by atomic absorption spectrum. The results indicate that the K concentrations in bone ash is logarithmic normal distribution, ranging level is 0.75-8.44 g/kg ash, the average and standard deviation is respectively 2.40 and 1.52 g/kg ash. The highest concentration (4.88 g/kg ash) appears in infantile stage (< 1y), the lowest concentration (1.59 g/kg ash) appears in young stage (2-5 y). The lower concentration (1.88 g/kg ash) appears in adolescence (11-20 y). The K concentration in wet bone as a percentage of weight is 0.067%. The specific activities of K-40 in bone is about 22 mBq/g wet bone. The total radioactivity of K-40 in whole bone is 220 Bq. The annual absorbed dose is received in adult bone from K-40 is estimated to be 95 μGy

Urine nickel concentrations in nickel-exposed workers.

Science.gov (United States)

Bernacki, E J; Parsons, G E; Roy, B R; Mikac-Devic, M; Kennedy, C D; Sunderman, F W

1978-01-01

Electrothermal atomic absorption spectrometry was employed for analyses of nickel concentrations in urine samples from nickel-exposed workers in 10 occupational groups and from non-exposed workers in two control groups. Mean concentrations of nickel in urine were greatest in workers who were exposed to inhalation of aerosols of soluble nickel salts (e.g., workers in nickel plating operations and in an electrolytic nickel refinery). Less marked increases in urine nickel concentrations were found in groups of metal sprayers, nickel battery workers, bench mechanics and are welders. No significant increases in mean concentrations of nickel were found in urine samples from workers who performed grinding, buffing and polishing of nickel-containing alloys or workers in a coal gasification plant who employed Raney nickel as a hydrogenation catalyst. Measurements of nickel concentrations in urine are more sensitive and practical than measurements of serum nickel concentrations for evaluation of nickel exposures in industrial workers.

Butanol production from concentrated lactose/whey permeate: Use of pervaporation membrane to recover and concentrate product

Science.gov (United States)

In these studies butanol (acetone butanol ethanol, or ABE) was produced from concentrated lactose/whey permeate containing 211 gL-1 lactose. Fermentation of such a highly concentrated lactose solution was possible due to simultaneous product removal using a pervaporation membrane. In this system a p...

Cesium Concentration in MCU Solvent

International Nuclear Information System (INIS)

Walker, D

2006-01-01

During Modular Caustic-Side Solvent Extraction (CSSX) Unit (MCU) operations, Cs-137 concentrations in product streams will vary depending on the location in the process and on the recent process conditions. Calculations of cesium concentrations under a variety of operating conditions reveal the following: (1) Under nominal operations with salt solution feed containing 1.1 Ci Cs-137 per gallon, the maximum Cs-137 concentration in the process will occur in the strip effluent (SE) and equal 15-16.5 Ci/gal. (2) Under these conditions, the majority of the solvent will contain 0.005 to 0.01 Ci/gal, with a limited portion of the solvent in the contactor stages containing ∼4 Ci/gal. (3) When operating conditions yield product near 0.1 Ci Cs-137/gal in the decontaminated salt solution (DSS), the SE cesium concentration will be the same or lower than in nominal operations, but majority of the stripped solvent will increase to ∼2-3 Ci/gal. (4) Deviations in strip and waste stream flow rates cause the largest variations in cesium content: (a) If strip flow rates deviate by -30% of nominal, the SE will contain ∼23 Ci/gal, although the cesium content of the solvent will increase to only 0.03 Ci/gal; (b) If strip flow rate deviates by -77% (i.e., 23% of nominal), the SE will contain 54 Ci/gal and solvent will contain 1.65 Ci/gal. At this point, the product DSS will just reach the limit of 0.1 Ci/gal, causing the DSS gamma monitors to alarm; and (c) Moderate (+10 to +30%) deviations in waste flow rate cause approximately proportional increases in the SE and solvent cesium concentrations. Recovery from a process failure due to poor cesium stripping can achieve any low cesium concentration required. Passing the solvent back through the contactors while recycling DSS product will produce a ∼70% reduction during one pass through the contactors (assuming the stripping D value is no worse than 0.36). If the solvent is returned to the solvent hold tank (containing additional

Measuring Concentration in Data with an Exogenous Order

OpenAIRE

Abedieh, Jasmin; Groll, Andreas; Eugster, Manuel J. A.

2013-01-01

Concentration measures order the statistical units under observation according to their market share. However, there are situations where an order according to an exogenous variable is more appropriate or even required. The present article introduces a generalized definition of market concentration and defines a corresponding concentration measure. It is shown that this generalized concept of market concentration satisfies the common axioms of (classical) concentration measures. In an appl...

Spectral SP: A New Approach to Mapping Reservoir Flow and Permeability

Energy Technology Data Exchange (ETDEWEB)

Thomas, Donald M. [Univ. of Hawaii, Honolulu, HI (United States). Hawaii Inst. of Geophysics; Lienert, Barry R. [Univ. of Hawaii, Honolulu, HI (United States). Hawaii Inst. of Geophysics; Wallin, Erin L. [Univ. of Hawaii, Honolulu, HI (United States); Gasperikova, Erika [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2014-05-27

Our objectives for the current project were to develop an innovative inversion and analysis procedure for magnetotelluric field data and time variable self-potentials that will enable us to map not only the subsurface resistivity structure of a geothermal prospect but to also delineate the permeability distribution within the field. Hence, the ultimate objective were to provide better targeting information for exploratory and development drilling of a geothermal prospect. Field data were collected and analyzed from the Kilauea Summit, Kilauea East Rift Zone, and the Humuula Saddle between Mauna Loa and Mauna Kea volcanoes. All of these areas were known or suspected to have geothermal activity of varying intensities. Our results provided evidence for significant long-term coordinated changes in spontaneous potential that could be associated with subsurface flows, significant interferences were encountered that arose from surface environmental changes (rainfall, temperature) that rendered it nearly impossible to unequivocally distinguish between deep fluid flow changes and environmental effects. Further, the analysis of the inferred spontaneous potential changes in the context of depth of the signals, and hence, permeability horizons, were unable to be completed in the time available.

Local Community Advocacy for the Thirty Meter Telescope on the Big Island of Hawai’i

Science.gov (United States)

Currie, Thayne; Ha, Richard; Imai-Hong, Amber; Silva, Jasmin; Stark, Chris; Naea Stevens, Dashiel

2018-01-01

The Thirty Meter Telescope project is a next-generation ground-based optical/infrared telescope planned for construction on Mauna Kea. It is also a prominent social issue in Hawai’i, touching upon a wide range of island-specific issues, including economic/educational opportunities and justice, Hawaii’s long and proud history of astronomy/navigation, the cultural significance of Mauna Kea to some Hawaiians, and Hawaiian sovereignty. In this talk, we describe local community outreach carried out by Hawai’i island resident members of our group, Yes2TMT, and also by the pro-TMT Hawaiian group P.U.E.O based in Hilo. We have cultivated a substantial social media community and persistent on-the-ground advocacy that addresses the many misconceptions about TMT while providing an outlet for concerns from our neighbors. Since early 2016 and thanks to the efforts of many on Hawai’i, support for TMT has increased, especially from the Hawaiian community: the project is now favored by at least 70% of Hawaii’s residents. Our goal is to help bring TMT to Hawai’i under conditions deemed acceptable by the vast majority of the local community.

Hydrophobicity and charge shape cellular metabolite concentrations.

Directory of Open Access Journals (Sweden)

Arren Bar-Even

2011-10-01

Full Text Available What governs the concentrations of metabolites within living cells? Beyond specific metabolic and enzymatic considerations, are there global trends that affect their values? We hypothesize that the physico-chemical properties of metabolites considerably affect their in-vivo concentrations. The recently achieved experimental capability to measure the concentrations of many metabolites simultaneously has made the testing of this hypothesis possible. Here, we analyze such recently available data sets of metabolite concentrations within E. coli, S. cerevisiae, B. subtilis and human. Overall, these data sets encompass more than twenty conditions, each containing dozens (28-108 of simultaneously measured metabolites. We test for correlations with various physico-chemical properties and find that the number of charged atoms, non-polar surface area, lipophilicity and solubility consistently correlate with concentration. In most data sets, a change in one of these properties elicits a ~100 fold increase in metabolite concentrations. We find that the non-polar surface area and number of charged atoms account for almost half of the variation in concentrations in the most reliable and comprehensive data set. Analyzing specific groups of metabolites, such as amino-acids or phosphorylated nucleotides, reveals even a higher dependence of concentration on hydrophobicity. We suggest that these findings can be explained by evolutionary constraints imposed on metabolite concentrations and discuss possible selective pressures that can account for them. These include the reduction of solute leakage through the lipid membrane, avoidance of deleterious aggregates and reduction of non-specific hydrophobic binding. By highlighting the global constraints imposed on metabolic pathways, future research could shed light onto aspects of biochemical evolution and the chemical constraints that bound metabolic engineering efforts.

Relationship between silicon concentration and creatinine clearance

International Nuclear Information System (INIS)

Miura, Y.; Nakai, K.; Itoh, C.; Horikiri, J.; Sera, K.; Sato, M.

1998-01-01

Silicon levels in dialysis patients are markedly increasing. Using PIXE we determined the relationship between silicon concentration and creatinine clearance in 30 samples. Urine silicon concentration were significantly correlated to creatinine clearance (p<0.001). And also serum silicon concentration were significantly correlated to creatinine clearance (p<0.0001). (author)

Cream concentrated latex for foam rubber products

Science.gov (United States)

Suksup, R.; Imkaew, C.; Smitthipong, W.

2017-12-01

Fresh natural latex (around 40% rubber and 60% water) can be transformed to concentrated natural latex (around 60% rubber and 40% water) in order to realise economical transportation and easier latex product’s preparation. The concentrated natural latex is an extremely valuable material. It can be applied for many types of products, for example, foam rubber as pillow and mattress, elastic band, etc. Industrially, the concentrated natural latex can be prepared by centrifugation which requires an enormous expensive machine. From the eco-friendly products point of view, most of rubber entrepreneurs in the world try to develop a green rubber product. So, the main objective of this study is to prepare the cream concentrated latex without any sophisticated machine. Thus, we work on a simple, cheap and green method that does not use any expensive machine but uses water-based chemical as sodium alginate to prepare the cream concentrated latex. The optimal amount of sodium alginate in the latex was studied. The main characteristics of the cream concentrated latex were tested by various technics, such as alkalinity, total solid content (TSC), dry rubber content (DRC), etc. We found that there are no significant differences of results between fresh natural latex and cream concentrated latex, except for the TSC and DRC. The TSC and DRC of cream latex are higher than those of fresh natural latex. Finally, we propose a model of natural rubber particle and sodium alginate to form the cream concentrated latex.

Rapid determination of radon daughter concentrations

International Nuclear Information System (INIS)

Bigu, J.

1990-08-01

A technical evaluation of four radon 222 progeny measuring instruments has been conducted. The evaluation has been carried out under laboratory controlled conditions and at several locations in an underground uranium mine. The laboratory evaluation consisted of a thorough study of the behaviour and performance of the instruments under a wide variety of environmental conditions such as radon 222 gas concentration, radon 222 progeny concentration, temperature, relative humidity, aerosol concentration, and gamma-field exposure. The four instruments tested were: the Pylon WL-1000C, the MDA IWLM-811, the MIMIL IIM, and the EDA WLM-30. The readings of the instruments were compared with a widely accepted radon 222 progeny concentration measuring method, namely, the Thomas-Tsivoglou method. Two variables affected two instruments significantly, namely, under high aerosol concentration conditions, one of the instruments (EDA WLM-30) ceased to operate because of filter loading. The other variable was gamma-field exposure which affected another instrument (MDA-811) adversely. The instruments were rated according to several criteria. The overall best performer was the MIMIL IIM, although other instruments also fared quite well under a variety of experimental conditions

Hip implants - Paper VI - Ion concentrations

Energy Technology Data Exchange (ETDEWEB)

Sargeant, A. [Department of Biological Sciences, Ohio Northern University, Ada, OH 45810 (United States); Goswami, T. [Department of Mechanical Engineering, Ohio Northern University, Ada, OH 45810 (United States)]. E-mail: t-goswami@onu.edu

2007-07-01

Total hip-joint arthroplasty is performed in increasing numbers where it translates to about 0.16-0.2% of population per year in industrial countries. In most cases, an implant is a metallic component articulating with a metal, ceramic or poly-ethylene liner as seen in the case of hip, knee and spine. The metal implants release ions in vivo. Therefore, there is a need to study metallic implants and ions released as a result. Toxic concentrations of ions can lead to many adverse physiological effects, including cytotoxicity, genotoxicity, carcinogenicity, and metal sensitivity. There is a need to map ion concentrations establishing boundaries between normal and toxic levels; which however, does not exist. Reference levels of ion concentrations in body fluids and tissues determined by many studies are compiled, reviewed, and presented in this paper. The concentrations of ions released from different alloys, including cobalt, chromium, nickel, molybdenum titanium, aluminum, and vanadium, are presented in this paper. This paper reviews the literature pertaining to clinical data on metal ion concentrations in patients with metal joint prostheses, and laboratory data on the physiological effects of the metals.

Monitoring of radon concentration in dwellings

International Nuclear Information System (INIS)

Kurosawa, Ryuhei

1991-01-01

Radon problems in dwellings have recently received much attention. Radon concentration in dwellings, as well as in the general environment, varies with various factors such as meteorological conditions and soil components. Therefore, a long term monitoring of radon concentration is required to obtain an average concentration. This paper reviews a passive type radon monitor that is handy and allows a long term radon monitoring. It provides the structure and principle of the radon monitor, covering the type, filter function, sensitivity of diffusion collecting type (cup type), electrostatic collecting type, adsorption collecting type, and detector of radon monitor. Actual examples of the radon monitor are also given. Radon daughter nuclides will have become major foci of exposure countermeasures. In the future, the development of a passive type monitor for determining potential alpha energy concentration is required. (N.K.)

Characterization of high concentration dust generator

International Nuclear Information System (INIS)

Shimura, Toichiro; Yokochi, Akira

1999-01-01

This paper describes the development of fluidized bed type high concentration dust generator that keeps for long period dust concentration range of about 10 mg/m 3 for the study of working place monitoring system and evaluation of respirator. The generator is keeping constant powder in fluidized bed for keeping the dust concentration. It is necessary to keep constant feeding rate of powder in order to keep the quantity of dust in the fluidized bed. Our generator enables to obtain constant feeding rate by a screw feeder and by using mixed powder with fluidising particles (glass beads) before feeding. The generator produces high concentration dust of 11.3 mg/m 3 ± 1.0 mg/m 3 for about 5 hours and keeps the dust size 4.2-4.6 μm in mass median aerodynamic diameter with reasonable reproducibility. (author)

Indoor radon concentrations in Vushtrri, Kosovo

International Nuclear Information System (INIS)

Xhafa, B.; Jonuzaj, A.; ); Bekteshi, S.; Ahmetaj, S.; Kabashi, S.; )

2009-01-01

Indoor air radon concentration was measured by exposing trac ketch detectors in the two elementary schools, one high school, a kindergarten and the hospital in the city of Vushtrri. Measurements were performed with the radon monitor PRM-145, which uses alpha scintillation cells and serves to determine the current concentration of radon. The results we obtained are in the range between the average values of radon for the interior spaces, and values that pose a potential risk for lung cancer. Measuring the concentration of radon was done in total of 34 rooms and came up with values which are between 28Bqm -3 and 398Bqm -3 . In order to reduce the concentration of radon, we have built a ventilation pump, then we performed repeated measurements and finally came with results between 130-145Bqm -3 .

RX: a nonimaging concentrator.

Science.gov (United States)

Miñano, J C; Benítez, P; González, J C

1995-05-01

A detailed description of the design procedure for a new concentrator, RX, and some examples of it's use are given. The method of design is basically the same as that used in the design of two other concentrators: the RR and the XR [Appl. Opt. 31, 3051 (1992)]. The RX is ideal in two-dimensional geometry. The performance of the rotational RX is good when the average angular spread of the input bundle is small: up to 95% of the power of the input bundle can be transferred to the output bundle (with the assumption of a constant radiance for the rays of the input bundle).

Computational algorithm for molybdenite concentrate annealing

International Nuclear Information System (INIS)

Alkatseva, V.M.

1995-01-01

Computational algorithm is presented for annealing of molybdenite concentrate with granulated return dust and that of granulated molybdenite concentrate. The algorithm differs from the known analogies for sulphide raw material annealing by including the calculation of return dust mass in stationary annealing; the latter quantity varies form the return dust mass value obtained in the first iteration step. Masses of solid products are determined by distribution of concentrate annealing products, including return dust and benthonite. The algorithm is applied to computations for annealing of other sulphide materials. 3 refs

Final survey reports on radon concentration in Japan

International Nuclear Information System (INIS)

1997-03-01

In order to grasp the present state of indoor radon concentration all over Japan, this survey was conducted in five years from Heisei 4 FY to 8 FY. Measurements were conducted using a radon and thoron separation apparatus so as to enable to develop radon and thoron separately. This was only one survey all over Japan obtained the only radon concentration by removing thoron perfectly. However, it was planned to obtain the mean indoor radon concentration all over Japan by limiting 20 houses for measurement aim because of limitation on numbers of the apparatus. In this survey, no extremely high region of the radon concentration was found. However, it was comparatively higher in Chugoku, Kinki and Kyushu-Okinawa areas, but was comparatively low in Kanto area. These results showed the same tendency as those of γ-ray level from the ground, and the radon concentration also showed temperature difference of a tendency of higher west and lower east. In this survey, seasonal variation of the radon concentration was found. In the third quarter (from October to December) maximum radon concentration (mean value: 15 Bq/cu m) and in the second quarter, the minimum concentration (mean value: 9 Bq/cu m) were observed, respectively. On comparing the indoor radon concentration of each housing structure used in enquete survey, concrete block house showed higher radon concentration. On its arithmetic mean, the radon concentration was high in order of concrete, steel frame, and wood constructions, and lowest in prefabricated house. The radon concentration of the concrete construction showed about 1.8 times higher than that of the wood construction. (G.K.)

Characterizing marijuana concentrate users: A web-based survey.

Science.gov (United States)

Daniulaityte, Raminta; Lamy, Francois R; Barratt, Monica; Nahhas, Ramzi W; Martins, Silvia S; Boyer, Edward W; Sheth, Amit; Carlson, Robert G

2017-09-01

The study seeks to characterize marijuana concentrate users, describe reasons and patterns of use, perceived risk, and identify predictors of daily/near daily use. An anonymous web-based survey was conducted (April-June 2016) with 673 US-based cannabis users recruited via the Bluelight.org web-forum and included questions about marijuana concentrate use, other drugs, and socio-demographics. Multivariable logistic regression analyses were conducted to identify characteristics associated with greater odds of lifetime and daily use of marijuana concentrates. About 66% of respondents reported marijuana concentrate use. The sample was 76% male, and 87% white. Marijuana concentrate use was viewed as riskier than flower cannabis. Greater odds of marijuana concentrate use was associated with living in states with "recreational" (AOR=4.91; p=0.001) or "medical, less restrictive" marijuana policies (AOR=1.87; p=0.014), being male (AOR=2.21, p=0.002), younger (AOR=0.95, pmarijuana concentrate users reported daily/near daily use. Greater odds of daily concentrate use was associated with being male (AOR=9.29, p=0.033), using concentrates for therapeutic purposes (AOR=7.61, p=0.001), using vape pens for marijuana concentrate administration (AOR=4.58, p=0.007), and lower perceived risk of marijuana concentrate use (AOR=0.92, p=0.017). Marijuana concentrate use was more common among male, younger and more experienced users, and those living in states with more liberal marijuana policies. Characteristics of daily users, in particular patterns of therapeutic use and utilization of different vaporization devices, warrant further research with community-recruited samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Population PK modelling and simulation based on fluoxetine and norfluoxetine concentrations in milk: a milk concentration-based prediction model.

Science.gov (United States)

Tanoshima, Reo; Bournissen, Facundo Garcia; Tanigawara, Yusuke; Kristensen, Judith H; Taddio, Anna; Ilett, Kenneth F; Begg, Evan J; Wallach, Izhar; Ito, Shinya

2014-10-01

Population pharmacokinetic (pop PK) modelling can be used for PK assessment of drugs in breast milk. However, complex mechanistic modelling of a parent and an active metabolite using both blood and milk samples is challenging. We aimed to develop a simple predictive pop PK model for milk concentration-time profiles of a parent and a metabolite, using data on fluoxetine (FX) and its active metabolite, norfluoxetine (NFX), in milk. Using a previously published data set of drug concentrations in milk from 25 women treated with FX, a pop PK model predictive of milk concentration-time profiles of FX and NFX was developed. Simulation was performed with the model to generate FX and NFX concentration-time profiles in milk of 1000 mothers. This milk concentration-based pop PK model was compared with the previously validated plasma/milk concentration-based pop PK model of FX. Milk FX and NFX concentration-time profiles were described reasonably well by a one compartment model with a FX-to-NFX conversion coefficient. Median values of the simulated relative infant dose on a weight basis (sRID: weight-adjusted daily doses of FX and NFX through breastmilk to the infant, expressed as a fraction of therapeutic FX daily dose per body weight) were 0.028 for FX and 0.029 for NFX. The FX sRID estimates were consistent with those of the plasma/milk-based pop PK model. A predictive pop PK model based on only milk concentrations can be developed for simultaneous estimation of milk concentration-time profiles of a parent (FX) and an active metabolite (NFX). © 2014 The British Pharmacological Society.

Cerebral Lactate Concentration in Neonatal Hypoxic-Ischemic Encephalopathy: In Relation to Time, Characteristic of Injury, and Serum Lactate Concentration

Directory of Open Access Journals (Sweden)

Tai-Wei Wu

2018-05-01

Full Text Available BackgroundCerebral lactate concentration can remain detectable in neonatal hypoxic-ischemic encephalopathy (HIE after hemodynamic stability. The temporal resolution of regional cerebral lactate concentration in relation to the severity or area of injury is unclear. Furthermore, the interplay between serum and cerebral lactate in neonatal HIE has not been well defined. The study aims to describe cerebral lactate concentration in neonatal HIE in relation to time, injury, and serum lactate.Design/methodsFifty-two newborns with HIE undergoing therapeutic hypothermia (TH were enrolled. Magnetic resonance imaging and spectroscopy (MRI + MR spectroscopy were performed during and after TH at 54.6 ± 15.0 and 156 ± 57.6 h of life, respectively. Severity and predominant pattern of injury was scored radiographically. Single-voxel 1H MR spectra were acquired using short-echo (35 ms PRESS sequence localized to the basal ganglia (BG, thalamus (Thal, gray matter (GM, and white matter. Cerebral lactate concentration was quantified by LCModel software. Serum and cerebral lactate concentrations were plotted based on age at time of measurement. Multiple comparisons of regional cerebral lactate concentration based on severity and predominant pattern of injury were performed. Spearman’s Rho was computed to determine correlation between serum lactate and cerebral lactate concentration at the respective regions of interest.ResultsOverall, serum lactate concentration decreased over time. Cerebral lactate concentration remained low for less severe injury and decreased over time for more severe injury. Cerebral lactate remained detectable even after TH. During TH, there was a significant higher concentration of cerebral lactate at the areas of injury and also when injury was more severe. However, these differences were no longer observed after TH. There was a weak correlation between serum lactate and cerebral lactate concentration at the BG (rs�

Effect of paracentesis on ocular cloxacillin concentration

International Nuclear Information System (INIS)

Salminen, L.

1978-01-01

The effect of interior chamber puncture on cloxacillin concentration in the rabbit eye after intravenous injection was studied using a radioactive tracer method. The enhancement in drug concentration caused by paracentesis was most immediate and significant in the iris-ciliary body preparation. It was soon followed by high cloxacillin concentration in the aqueous humour, which contributed to elevated cloxacillin levels in the cornea, lens and anterior vitreous body, when compared to normal material. Contrary to normal eyes, cloxacillin concentration in the cornea of the punctured eyes was higher than in the limbal area. The morphological changes occurring after paracentesis are discussed. The breakdown of the hydrodynamic equilibrium in the eye, suggested as the only change after paracentesis by Raviola (1974), cannot merely explain the cloxacillin concentration changes measured in the punctured eye. (author)

Tritium concentration monitor

International Nuclear Information System (INIS)

Shono, Kosuke.

1991-01-01

A device for measuring the concentration of tritium in gaseous wastes in a power plant and a nuclear fuel reprocessing plant is reduced in the size and improved in performance. The device of the present invention pressurizes a sampling gas and cools it to a dew point. Water content in the sampling gas cooled to the dew point is condensated and recovered to a fine tube-like water content recovering container. The concentration of the recovered condensates is measured by a tritium density analyzer. With such procedures, since the specimen is pressurized, the dew point can be elevated. Accordingly, the size of the cooling device can be decreased, enabling to contribute to the reduction of the size of the entire device. Further, since the water content recovering device is formed as a fine tube, the area of contact between the specimen gas and the liquid condensated water can be reduced. Accordingly, evaporation of the liquid condensates can be prevented. (I.S.)

Indoor radon concentration in Poland

International Nuclear Information System (INIS)

Mamont-Ciesla, K.; Jagielak, J.; Rosinski, S.W.; Sosinka, A.; Bysiek, M.; Henschke, J.

1996-01-01

Preliminary survey of Rn concentration indoors by means of track detectors and y-ray dose rate with the use of TLD in almost 500 homes in selected areas of Poland was performed in the late 1980s. It was concluded that radon contributes 1.16 mSv i.e. about 46 per cent of the total natural environment ionizing radiation dose to the Polish population. Comparison of the average radon concentrations in 4 seasons of a year and in 3 groups of buildings: masonry, concrete and wood, revealed that the ground beneath the building structure is likely the dominant source of radon indoors. Since the National Atomic Energy Agency in its regulations of 1988-03-31 set up the permissible limit of the equilibrium equivalent concentration of radon in new buildings (equal 100 Bq/m3), the nation-scale survey project for radon in buildings has been undertaken. These regulations were supposed to take effect in 1995-01-01. The project has 3 objectives: to estimate the radiation exposure due to radon daughters received by Polish population to identify radon-prone areas in Poland to investigate dependence of the indoor radon concentrations on such parameters as: type of construction material, presence (or absence) of cellar under the building, number of floor

Particle interactions in concentrated suspensions

International Nuclear Information System (INIS)

Mondy, L.A.; Graham, A.L.; Abbott, J.R.; Brenner, H.

1993-01-01

An overview is presented of research that focuses on slow flows of suspensions in which colloidal and inertial effects are negligibly small. The authors describe nuclear magnetic resonance imaging experiments to quantitatively measure particle migration occurring in concentrated suspensions undergoing a flow with a nonuniform shear rate. These experiments address the issue of how the flow field affects the microstructure of suspensions. In order to understand the local viscosity in a suspension with such a flow-induced, spatially varying concentration, one must know how the viscosity of a homogeneous suspension depends on such variables as solids concentration and particle orientation. The authors suggest the technique of falling ball viscometry, using small balls, as a method to determine the effective viscosity of a suspension without affecting the original microstructure significantly. They also describe data from experiments in which the detailed fluctuations of a falling ball's velocity indicate the noncontinuum nature of the suspension and may lead to more insights into the effects of suspension microstructure on macroscopic properties. Finally, they briefly describe other experiments that can be performed in quiescent suspensions (in contrast to the use of conventional shear rotational viscometers) in order to learn more about boundary effects in concentrated suspensions

Color corrected Fresnel lens for solar concentration

International Nuclear Information System (INIS)

Kritchman, E.M.

1979-01-01

A new linear convex Fresnel lens with its groove side down is described. The design philosophy is similar to the highly concentrating two focal Fresnel lens but including a correction for chromatic aberration. A solar concentration ratio as high as 80 is achieved. For wide acceptance angles the concentration nears the theoretical maximum. (author)

Uranium concentration monitor manual, secondary intermediate evaporator

International Nuclear Information System (INIS)

Russo, P.A.; Sprinkle, J.K. Jr.; Slice, R.W.; Strittmatter, R.B.

1985-08-01

This manual describes the design, operation, and measurement control procedures for the automated uranium concentration monitor on the secondary intermediate evaporator at the Oak Ridge Y-12 Plant. The nonintrusive monitor provides a near-real time readout of uranium concentration in the return loop of time recirculating evaporator for purposes of process monitoring and control. A detector installed near the bottom of the return loop is used to acquire spectra of gamma rays from the evaporator solutions during operation. Pulse height analysis of each spectrum gives the information required to deduce the concentration of uranium in the evaporator solution in near-real time. The visual readout of concentration is updated at the end of every assay cycle. The readout includes an alphanumeric display of uranium concentration and an illuminated, colored LED (in an array of colored LEDs) indicating whether the measured concentration is within (or above or below) the desired range. An alphanumeric display of evaporator solution acid molarity is also available to the operator. 9 refs., 16 figs., 4 tabs

Effect of the Carbon Concentration, Blend Concentration, and Renewal Rate in the Growth Kinetic of Chlorella sp.

Directory of Open Access Journals (Sweden)

Adriano Arruda Henrard

2014-01-01

Full Text Available The microalgae cultivation can be used as alternative sources of food, in agriculture, residual water treatment, and biofuels production. Semicontinuous cultivation is little studied but is more cost-effective than the discontinuous (batch cultivation. In the semicontinuous cultivation, the microalga is maintained in better concentration of nutrients and the photoinhibition by excessive cell is reduced. Thus, biomass productivity and biocompounds of interest, such as lipid productivity, may be higher than in batch cultivation. The objective of this study was to examine the influence of blend concentration, medium renewal rate, and concentration of sodium bicarbonate on the growth of Chlorella sp. during semicontinuous cultivation. The cultivation was carried out in Raceway type bioreactors of 6 L, for 40 d at 30°C, 41.6 µmol m−2 s−1, and a 12 h light/dark photoperiod. Maximum specific growth rate (0.149 d−1 and generating biomass (2.89 g L−1 were obtained when the blend concentration was 0.80 g L−1, the medium renewal rate was 40%, and NaHCO3 was 1.60 g L−1. The average productivity (0.091 g L−1 d−1 was achieved with 0.8 g L−1 of blend concentration and NaHCO3 concentration of 1.6 g L−1, independent of the medium renewal rate.

Rennet-induced gelation of concentrated milk in the presence of sodium caseinate: differences between milk concentration using ultrafiltration and osmotic stressing.

Science.gov (United States)

Krishnankutty Nair, P; Corredig, M

2015-01-01

Concentrating milk is a common unit operation in the dairy industry. With the reduction of water, the particles interact more frequently with each other and the functionality of the casein micelles may depend on the interactions occurring during concentration. The objective of this research was to investigate the effect of concentration on the renneting properties of the casein micelles by comparing 2 concentration methods: ultrafiltration and osmotic stressing. Both methods selectively concentrate the protein fraction of milk, while the composition of the soluble phase is unaltered. To evaluate possible differences in the rearrangements of the casein micelles during concentration, renneting properties were evaluated with or without the addition of soluble caseins, added either before or after concentration. The results indicate that casein micelles undergo rearrangements during concentration and that shear during membrane filtration may play a role in affecting the final properties of the milk. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

21 CFR 146.150 - Canned concentrated orange juice.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Canned concentrated orange juice. 146.150 Section... Fruit Juices and Beverages § 146.150 Canned concentrated orange juice. (a) Canned concentrated orange... labeling of ingredients prescribed for frozen concentrated orange juice by § 146.146, except that it is not...

Refractometric total protein concentrations in icteric serum from dogs.

Science.gov (United States)

Gupta, Aradhana; Stockham, Steven L

2014-01-01

To determine whether high serum bilirubin concentrations interfere with the measurement of serum total protein concentration by refractometry and to assess potential biases among refractometer measurements. Evaluation study. Sera from 2 healthy Greyhounds. Bilirubin was dissolved in 0.1M NaOH, and the resulting solution was mixed with sera from 2 dogs from which food had been withheld to achieve various bilirubin concentrations up to 40 mg/dL. Refractometric total protein concentrations were estimated with 3 clinical refractometers. A biochemical analyzer was used to measure biuret assay-based total protein and bilirubin concentrations with spectrophotometric assays. No interference with refractometric measurement of total protein concentrations was detected with bilirubin concentrations up to 41.5 mg/dL. Biases in refractometric total protein concentrations were detected and were related to the conversion of refractive index values to total protein concentrations. Hyperbilirubinemia did not interfere with the refractometric estimation of serum total protein concentration. The agreement among total protein concentrations estimated by 3 refractometers was dependent on the method of conversion of refractive index to total protein concentration and was independent of hyperbilirubinemia.

Adiabatic theorem and spectral concentration

International Nuclear Information System (INIS)

Nenciu, G.

1981-01-01

The spectral concentration of arbitrary order, for the Stark effect is proved to exist for a large class of Hamiltonians appearing in nonrelativistic and relativistic quantum mechanics. The results are consequences of an abstract theorem about the spectral concentration for self-ad oint operators. A general form of the adiabatic theorem of quantum mechanics, generalizing an earlier result of the author as well as some results of Lenard, is also proved [ru

Building integrated concentrating photovoltaics: A review

International Nuclear Information System (INIS)

Chemisana, Daniel

2011-01-01

For building integration, Concentrating Photovoltaic (CPV) systems can offer a host of advantages over conventional flat panel devices, the most notable being: a higher electrical conversion efficiency in the PV cells, better use of space, ease of recycling of constituent materials, and reduced use of toxic products involved in the PV cells' production process. However, the viability of Building-Integrated Concentrating PV (BICPV) systems is dependent on their ability to offer a comparative economic advantage over flat panel photovoltaic technologies whose market prices are decreasing from day to day and which offer other advantages such as ease of replacement of structural elements. A comparative analysis is presented of the main existing CPV systems' suitability for use in buildings, in which the different challenges specific to integration of each system are discussed. The systems are categorized by type of concentration technology and concentration factor. (author)

Mariner 9 photographs of small-scale volcanic structures on Mars

Science.gov (United States)

Greeley, R.

1972-01-01

Surface features on the flanks of Martian shield volcanoes photographed by Mariner 9 are identified as lava flow channels, rift zones, and partly collapsed lava tubes by comparisons with similar structures on the flanks of Mauna Loa shield volcano, Hawaii. From these identifications, the composition of the Martian lava flows is interpreted to be basaltic, with viscosities ranging from those of fluid pahoehoe to more viscous aa.

Mariner 9 photographs of small volcanic structures on Mars

Science.gov (United States)

Greeley, R.

1973-01-01

Surface features on the flanks of martian shield volcanoes photographed by Mariner 9 are identified as lava flow channels, rift zones, and partly collapsed lava tubes by comparisons with similar structures on the flanks of Mauna Loa shield volcano, Hawaii. From these identification, the composition of the martian lava flows in interpreted to be basaltic, with viscosities ranging from those of fluid pahoehoe to more viscous aa.

Comparative survey of outdoor, residential and workplace radon concentrations

International Nuclear Information System (INIS)

Barros, Nirmalla; Field, R. William; Field, Dan W.; Steck, Daniel J.

2015-01-01

This study investigated radon concentrations in above-ground (i.e. first floor) workplace in Missouri and compared them with above-ground radon concentrations in nearby homes and outdoor locations. This study also examined the potential utility of using home and outdoor radon concentrations to predict the radon concentration at a nearby workplace (e.g. county agencies and schools). Even though workplace radon concentrations were not statistically different from home radon concentrations, the radon concentration at a particular home, or outdoor location, was a poor predictor of the radon concentration at a nearby workplace. Overall, 9.6 and 9.9 % of homes and workplace, respectively, exhibited radon concentrations of ≥148 Bq m -3 . Because of the percentage of workplace with elevated radon concentrations, the results suggest that additional surveys of workplace radon concentrations are needed, especially in areas of high radon potential, to assess the contribution of workplace radon exposure to an individual's overall radon exposure. (authors)

21 CFR 146.145 - Orange juice from concentrate.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Orange juice from concentrate. 146.145 Section 146... Juices and Beverages § 146.145 Orange juice from concentrate. (a) Orange juice from concentrate is the food prepared by mixing water with frozen concentrated orange juice as defined in § 146.146 or with...

Characterization and concentration of manganese ore waste

International Nuclear Information System (INIS)

Lima, Rosa Malena Fernandes; Pereira, Eder Esper; Reis, Erica Linhares; Silva, Glaucia Regina da

2010-01-01

In this work is presented the tests results of characterization and concentration by gravity and flotation methods carried out with a manganese sample waste. By optical microscopy, SEM/EDS and X-ray diffractometry were identified the Mn minerals spessartite (20%), tephroite (15%), rhodonite (5%), rhodochrosite and carbonates minerals (29%), opaque minerals and others (16%), micaceus minerals (6%) and quartz (4%). It was obtained Mn metallurgical recovery of 58% with Mn concentrate contents varying from 30 to 32.5%. The concentrates SiO_2 contents of flotation were until 1.5% smaller than those contents of gravity method concentrates. (author)

Alignment method for parabolic trough solar concentrators

Science.gov (United States)

Diver, Richard B [Albuquerque, NM

2010-02-23

A Theoretical Overlay Photographic (TOP) alignment method uses the overlay of a theoretical projected image of a perfectly aligned concentrator on a photographic image of the concentrator to align the mirror facets of a parabolic trough solar concentrator. The alignment method is practical and straightforward, and inherently aligns the mirror facets to the receiver. When integrated with clinometer measurements for which gravity and mechanical drag effects have been accounted for and which are made in a manner and location consistent with the alignment method, all of the mirrors on a common drive can be aligned and optimized for any concentrator orientation.

Development of compound parabolic concentrators for solar energy

Energy Technology Data Exchange (ETDEWEB)

O' Gallagher, J.; Winston, R.

1983-10-01

The compound parabolic concentrator (CPC) is not a specific collector, but a family of collectors based on a general design principle for maximizing the geometric concentration, C, for radiation within a given acceptance half angle = thetac. This maximum limit exceeds by a factor of 2 to 4 that attainable by systems using focussing optics. The wide acceptance angles permitted using these techniques have several unique advantages for solar concentrators including the elimination of the diurnal tracking requirement at intermediate concentrations (up to about 10x), collection of circumsolar and some diffuse radiation and relaxed tolerances. Because of these advantages, CPC type concentrators have applications in solar energy wherever concentration is desired, e.g., for a wide variety of both thermal and photovoltaic uses. The basic principles of nonimaging optical design are reviewed. Selected configurations for both non-evacuated and evacuated thermal collector applications are discussed with particular emphasis on the most recent advances. The use of CPC type elements as secondary concentrators is illustrated in the context of higher concentration photovoltaic applications.

Obtain of uranium concentrates from fertil liquids

International Nuclear Information System (INIS)

Narvaez Castillo, W.A.

1992-01-01

This research tried to encounter the form to remove uranium from the rock in the best way, for that it was used different process like leaching, extraction, concentration and precipitation. To leach the mineral was chosen basic leaching, using a mixture of carbonate-sodium bicarbonate, this method is more adequated for the basic nature of the mineral. In extraction was used specific uranium ionic interchanges, so was chosen a tertiary amine like Alamina 336. The concentration phase is intimately binding with the extraction by ionic interchange, for the capability of resine's extraction to obtain concentrated liquids. When the liquids were obtained with high concentration of uranium in the same time were purified and then were precipitated, for that we employed a precipitant agent like: Sodium hydroxide, Amonium hydroxide, Magnesium hydroxide, Hydrogen peroxide and phosphates. With all concentrates we obtain the YELLOW CAKE

Luminescent Solar Concentrators with Fibre Geometry

NARCIS (Netherlands)

Edelenbosch, O.Y.; Fisher, M.; Patrignani, L.; Sark, W.G.J.H.M. van; Chatten, A.J.

2013-01-01

The potential of a fibre luminescent solar concentrator has been explored by means of both analytical and ray-tracing techniques. Coated fibres have been found to be more efficient than homogeneously doped fibres, at low absorption. For practical fibres concentration is predicted to be linear

Theoretical modelling of solar dish concentrator

International Nuclear Information System (INIS)

Yaaseen Rafeeu; Mohd Zainal Abidin Abdul Kadir; Senan Mohamed Abdulla; Nor Mariah Adam

2009-01-01

Full text: Concentrating solar power (CSP) technologies could be one of the major contributor to worlds future energy needs and which would be cheap and clean sources of energy. This would improve energy utilization, higher conversion efficiency with reliable and affordable supply of electricity to the public. The proposed approach is using different size and depth of solar dish concentrators to improve solar fraction using the aluminium foil as reflector. In this paper, different measurement of solar concentrators is investigated and aims to aims to introducing an improved methodology for solar fraction on incoming solar energy in wet climate. (author)

Concentrations of rare elements in some Australian soils

International Nuclear Information System (INIS)

Diatloff, E.; Smith, F.W.; Asher, C.J.

1996-01-01

Total, exchangeable, and soil solution concentrations were measured for 15 rare earth elements (REEs) in 9 soils from Queensland and New South Wales. In a further 10 acid soils, effects of amendment with CaCO 3 or CaSO 4 . 2H 2 O were measured on the concentrations of REEs in soil solution. The total concentration of the REEs in soil solutions from unamended soils ranged from below the detection limit (0.007 μM) to 0.64 μM. Lanthanum (La) and cerium (Ce) were the REEs present in the greatest concentrations, the highest concentrations measured in the diverse suite of soils being 0.13 μM La and 0.51 μM Ce. Rare earth elements with higher atomic numbers were present in very low concentrations. Exchangeable REEs accounted for 0.07 to 12.6% of the total REEs measured in the soils. Addition of CaCO 3 increased soil solution pH and decreased REE concentrations in soil solution, whilst CaSO 4 . 2H 2 O decreased soil solution pH and increased the concentrations of REEs in soil solution. Solubility calculations suggest that CePO 4 may be the phase controlling the concentration of Ce in soil solution. 33 refs., 6 tabs., 2 figs

Atmospheric relative concentrations in building wakes

International Nuclear Information System (INIS)

Ramsdell, J.V. Jr.; Simonen, C.A.

1997-05-01

This report documents the ARCON96 computer code developed for the U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation for potential use in control room habitability assessments. It includes a user's guide to the code, a description of the technical basis for the code, and a programmer's guide to the code. The ARCON96 code uses hourly meteorological data and recently developed methods for estimating dispersion in the vicinity of buildings to calculate relative concentrations at control room air intakes that would be exceeded no more than five percent of the time. The concentrations are calculated for averaging periods ranging from one hour to 30 days in duration. ARCON96 is a revised version of ARCON95, which was developed for the NRC Office of Nuclear Regulatory Research. Changes in the code permit users to simulate releases from area sources as well as point sources. The method of averaging concentrations for periods longer than 2 hours has also been changed. The change in averaging procedures increases relative concentrations for these averaging periods. In general, the increase in concentrations is less than a factor of two. The increase is greatest for relatively short averaging periods, for example 0 to 8 hours and diminishes as the duration of the averaging period increases

Plasma Glutamine Concentrations in Liver Failure.

Directory of Open Access Journals (Sweden)

Gunnel Helling

Full Text Available Higher than normal plasma glutamine concentration at admission to an intensive care unit is associated with an unfavorable outcome. Very high plasma glutamine levels are sometimes seen in both acute and chronic liver failure. We aimed to systematically explore the relation between different types of liver failure and plasma glutamine concentrations.Four different groups of patients were studies; chronic liver failure (n = 40, acute on chronic liver failure (n = 20, acute fulminant liver failure (n = 20, and post-hepatectomy liver failure (n = 20. Child-Pugh and Model for End-stage Liver Disease (MELD scores were assessed as indices of liver function. All groups except the chronic liver failure group were followed longitudinally during hospitalisation. Outcomes were recorded up to 48 months after study inclusion.All groups had individuals with very high plasma glutamine concentrations. In the total group of patients (n = 100, severity of liver failure correlated significantly with plasma glutamine concentration, but the correlation was not strong.Liver failure, regardless of severity and course of illness, may be associated with a high plasma glutamine concentration. Further studies are needed to understand whether high glutamine levels should be regarded as a biomarker or as a contributor to symptomatology in liver failure.

Polyaspartic Acid Concentration Controls the Rate of Calcium Phosphate Nanorod Formation in High Concentration Systems

Energy Technology Data Exchange (ETDEWEB)

Krogstad, Daniel V. [Biosystems and; Wang, Dongbo [Biosystems and; Lin-Gibson, Sheng [Biosystems and

2017-08-31

Polyelectrolytes are known to greatly affect calcium phosphate (CaP) mineralization. The reaction kinetics as well as the CaP phase, morphology and aggregation state depend on the relative concentrations of the polyelectrolyte and the inorganic ions in a complex, nonlinear manner. This study examines the structural evolution and kinetics of polyaspartic acid (pAsp) directed CaP mineralization at high concentrations of polyelectrolytes, calcium, and total phosphate (19–30 mg/mL pAsp, 50–100 mM Ca2+, Ca/P = 2). Using a novel combination of characterization techniques including cryogenic transmission electron microscopy (cryo-TEM), spectrophotometry, X-ray total scattering pair distribution function analysis, and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), it was determined that the CaP mineralization occurred over four transition steps. The steps include the formation of aggregates of pAsp stabilized CaP spherical nanoparticles (sNP), crystallization of sNP, oriented attachment of the sNP into nanorods, and further crystallization of the nanorods. The intermediate aggregate sizes and the reaction kinetics were found to be highly polymer concentration dependent while the sizes of the particles were not concentration dependent. This study demonstrates the complex role of pAsp in controlling the mechanism as well as the kinetics of CaP mineralization.

A concept for a thirty-meter telescope

Science.gov (United States)

Burgarella, Denis; Zamkotsian, Frederic; Dohlen, Kjetil; Ferrari, Marc; Hammer, Francois; Sayede, Frederic; Rigaud, Francois

2004-07-01

In May 2000, the Canada-France-Hawaii (CFHT) Telescope Science Advisory Committee solicited the Canadian, Hawaiian and French communities to propose concepts to replace the present CFH telescope by a larger telescope. Three groups were selected: Carlberg et al. (2001) in Canada, Khun et al. (2001) in Hawaii and Burgarella et al. (2001a) in France. The reports were delivered to CFHT in May 2001 and are now available throughout the CFHT website. One of the main constraints was due to the fact that the new and larger telescope should use as much as possible the existing site and be compliant with the Mauna Kea Science reserve Master Plan (2000). This plan analyses all aspects of the Mauna Kea summit but most of them are related to the facts that the mountain must be considered as a sacred area for indigenous Hawaiian people and that the ecosystem is fragile. But in addition, the plan also tries to account for the fact that the summit of Mauna Kea is a world famous site for astronomy. The points that we can highlight in the context of our project are of two types. Since then, the project evolved and Hawaii is not considered as the one and only site to build an Extremely Large Telescope (ELT). Moreover, the size of the primary mirror, which was strongly dependent on the above constraints, is no more limited to the 16 - 20 m which was our conclusion at this time. Nevertheless, the three points of the resolution are still valid and since then, we have kept on working on the concept by launching differnt follow-up studies that are necessary to start such a project. Of course, the main point is the Science Objectives which drive the main specifications for an ELT. But related technical studies are also mandatory e.g. Adaptive Optics, Building of a primary mirror larger than 30 m in diameter, Image Quality as a function of the segment size and shape.

The COronal Solar Magnetism Observatory (COSMO) Large Aperture Coronagraph

Science.gov (United States)

Tomczyk, Steve; Gallagher, Dennis; Wu, Zhen; Zhang, Haiying; Nelson, Pete; Burkepile, Joan; Kolinksi, Don; Sutherland, Lee

2013-04-01

The COSMO is a facility dedicated to observing coronal and chromospheric magnetic fields. It will be located on a mountaintop in the Hawaiian Islands and will replace the current Mauna Loa Solar Observatory (MLSO). COSMO will provide unique observations of the global coronal magnetic fields and its environment to enhance the value of data collected by other observatories on the ground (e.g. SOLIS, BBO NST, Gregor, ATST, EST, Chinese Giant Solar Telescope, NLST, FASR) and in space (e.g. SDO, Hinode, SOHO, GOES, STEREO, Solar-C, Solar Probe+, Solar Orbiter). COSMO will employ a fleet of instruments to cover many aspects of measuring magnetic fields in the solar atmosphere. The dynamics and energy flow in the corona are dominated by magnetic fields. To understand the formation of CMEs, their relation to other forms of solar activity, and their progression out into the solar wind requires measurements of coronal magnetic fields. The large aperture coronagraph, the Chromospheric and Prominence Magnetometer and the K-Coronagraph form the COSMO instrument suite to measure magnetic fields and the polarization brightness of the low corona used to infer electron density. The large aperture coronagraph will employ a 1.5 meter fuse silica singlet lens, birefringent filters, and a spectropolarimeter to cover fields of view of up to 1 degree. It will observe the corona over a wide range of emission lines from 530.3 nm through 1083.0 nm allowing for magnetic field measurements over a wide range of coronal temperatures (e.g. FeXIV at 530.3 nm, Fe X at 637.4 nm, Fe XIII at 1074.7 and 1079.8 nm. These lines are faint and require the very large aperture. NCAR and NSF have provided funding to bring the large aperture coronagraph to a preliminary design review state by the end of 2013. As with all data from Mauna Loa, the data products from COSMO will be available to the community via the Mauna Loa website: http://mlso.hao.ucar.edu

Tip-tilt compensation: Resolution limits for ground-based telescopes using laser guide star adaptive optics

International Nuclear Information System (INIS)

Olivier, S.S.; Max, C.E.; Gavel, D.T.; Brase, J.M.

1992-01-01

The angular resolution of long-exposure images from ground-based telescopes equipped with laser guide star adaptive optics systems is fundamentally limited by the the accuracy with which the tip-tilt aberrations introduced by the atmosphere can be corrected. Assuming that a natural star is used as the tilt reference, the residual error due to tilt anisoplanatism can significantly degrade the long-exposure resolution even if the tilt reference star is separated from the object being imaged by a small angle. Given the observed distribution of stars in the sky, the need to find a tilt reference star quite close to the object restricts the fraction of the sky over which long-exposure images with diffraction limited resolution can be obtained. In this paper, the authors present a comprehensive performance analysis of tip-tilt compensation systems that use a natural star as a tilt reference, taking into account properties of the atmosphere and of the Galactic stellar populations, and optimizing over the system operating parameters to determine the fundamental limits to the long-exposure resolution. Their results show that for a ten meter telescope on Mauna Kea, if the image of the tilt reference star is uncorrected, about half the sky can be imaged in the V band with long-exposure resolution less than 60 milli-arc-seconds (mas), while if the image of the tilt reference star is fully corrected, about half the sky can be imaged in the V band with long-exposure resolution less than 16 mas. Furthermore, V band images long-exposure resolution of less than 16 mas may be obtained with a ten meter telescope on Mauna Kea for unresolved objects brighter than magnitude 22 that are fully corrected by a laser guide star adaptive optics system. This level of resolution represents about 70% of the diffraction limit of a ten meter telescope in the V band and is more than a factor of 45 better than the median seeing in the V band on Mauna Kea

Isotopic constraints on the genesis and evolution of basanitic lavas at Haleakala, Island of Maui, Hawaii

Science.gov (United States)

Phillips, Erin H.; Sims, K.W.W.; Sherrod, David R.; Salters, Vincent; Blusztajn, Jurek; Dulaiova, Henrieta

2016-01-01

To understand the dynamics of solid mantle upwelling and melting in the Hawaiian plume, we present new major and trace element data, Nd, Sr, Hf, and Pb isotopic compositions, and 238U–230Th–226Ra and 235U–231Pa–227Ac activities for 13 Haleakala Crater nepheline normative basanites with ages ranging from ∼900 to 4100 yr B.P. These basanites of the Hana Volcanics exhibit an enrichment in incompatible trace elements and a more depleted isotopic signature than similarly aged Hawaiian shield lavas from Kilauea and Mauna Loa. Here we posit that as the Pacific lithosphere beneath the active shield volcanoes moves away from the center of the Hawaiian plume, increased incorporation of an intrinsic depleted component with relatively low 206Pb/204Pb produces the source of the basanites of the Hana Volcanics. Haleakala Crater basanites have average (230Th/238U) of 1.23 (n = 13), average age-corrected (226Ra/230Th) of 1.25 (n = 13), and average (231Pa/235U) of 1.67 (n = 4), significantly higher than Kilauea and Mauna Loa tholeiites. U-series modeling shows that solid mantle upwelling velocity for Haleakala Crater basanites ranges from ∼0.7 to 1.0 cm/yr, compared to ∼10 to 20 cm/yr for tholeiites and ∼1 to 2 cm/yr for alkali basalts. These modeling results indicate that solid mantle upwelling rates and porosity of the melting zone are lower for Hana Volcanics basanites than for shield-stage tholeiites from Kilauea and Mauna Loa and alkali basalts from Hualalai. The melting rate, which is directly proportional to both the solid mantle upwelling rate and the degree of melting, is therefore greatest in the center of the Hawaiian plume and lower on its periphery. Our results indicate that solid mantle upwelling velocity is at least 10 times higher at the center of the plume than at its periphery under Haleakala.

Determination of the concentration of {alpha} emitting radioactive aerosols; Mesure de la concentration des aerosols radioactifs emetteurs {alpha}

Energy Technology Data Exchange (ETDEWEB)

Labeyrie, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1953-06-15

In the first part of this work the techniques used for the quantitative measurement of the concentrations of aerosols carrying short lived (radon or thoron daughters) or long lived (uranium) {alpha} radioactive emitters are described. In the second part the author investigates the problem of the determination of radon concentration in air by means of activity determinations on airborne dusts. Special reference is made to the measurement of the radon active deposit on two types of dusts (iron oxide (yellow) and uranium oxide) in small chambers (6 liters). In the third part are given data resulting from determinations of radon and thoron concentrations in atmospheric air in the south of Paris area using this method. (author) [French] Dans la premiere partie de ce travail on expose les techniques utilisees pour la mesure quantitative des concentrations d'aerosols contenant des emetteurs radioactifs {alpha}, tant pour ceux a vie courte (derives du radon ou du thoron) que pour ceux a vie longue (uranium). Dans la seconde partie on traite le probleme de la determination de la concentration de l'air en radon par la mesure de l'activite des poussieres ayant sejourne dans cet air. En particulier, on indique pour de petits volumes (6 litres) la proportion de depot actif du radon qui est fixee sur deux types de poussieres (limonite et oxyde d'uranium) en fonction de la concentration de celles-ci. Dans la troisieme partie on donne quelques exemples de mesure par cette methode de la concentration en radon et en thoron de l'atmosphere de la region parisienne. (auteur)

Retrieve Aerosol Concentration Based On Surface Model and Distribution of Concentration of PM2.5 ——A Case Study of Beijing

Science.gov (United States)

Cui, H.

2017-12-01

As China's economy continues to grow, urbanization continues to advance, along with growth in all areas to pollutant emissions in the air industry, air quality also continued to deteriorate. Aerosol concentrations as a measure of air quality of the most important part of are more and more people's attention. Traditional monitoring stations measuring aerosol concentration method is accurate, but time-consuming and can't be done simultaneously measure a large area, can only rely on data from several monitoring sites to predict the concentration of the panorama. Remote Sensing Technology retrieves aerosol concentrations being by virtue of their efficient, fast advantages gradually into sight. In this paper, by the method of surface model to start with the physical processes of atmospheric transport, innovative aerosol concentration coefficient proposed to replace the traditional aerosol concentrations, pushed to a set of retrieval of aerosol concentration coefficient method, enabling fast and efficient Get accurate air pollution target area. At the same paper also monitoring data for PM2.5 in Beijing were analyzed from different angles, from the perspective of the data summarized in Beijing PM2.5 concentration of time, space, geographical distribution and concentration of PM2.5 and explored the relationship between aerosol concentration coefficient and concentration of PM2.5.

Postmortem Femoral Blood Concentrations of Risperidone

DEFF Research Database (Denmark)

Linnet, Kristian; Johansen, Sys Stybe

2014-01-01

Postmortem femoral blood concentrations of the antipsychotic drug risperidone and the active metabolite 9-hydroxyrisperidone were determined by an achiral LC-MS/MS method in 38 cases. The cause of death was classified as unrelated to risperidone in 30 cases, in which the sum of the concentration ...

Qualification standard for photovoltaic concentrator modules

Energy Technology Data Exchange (ETDEWEB)

McConnell, R.; Kurtz, S.; Bottenberg, W. R.; Hammond, R.; Jochums, S. W.; McDanal, A. J.; Roubideaux, D.; Whitaker, C.; Wohlgemuth, J.

2000-05-05

The paper describes a proposed qualification standard for photovoltaic concentrator modules. The standard's purpose is to provide stress tests and procedures to identify any component weakness in photovoltaic concentrator modules intended for power generation applications. If no weaknesses are identified during qualification, both the manufacturer and the customer can expect a more reliable product. The qualification test program for the standard includes thermal cycles, humidity-freeze cycles, water spray, off-axis beam damage, hail impact, hot-spot endurance, as well as electrical tests for performance, ground continuity, isolation, wet insulation resistance, and bypass diodes. Because concentrator module performance can not be verified using solar simulator and reference cell procedures suitable for flat-plate modules, the standard specifies an outdoor I-V test analysis allowing a performance comparison before and after a test procedure. Two options to this complex analysis are the use of a reference concentrator module for side-by-side outdoor comparison with modules undergoing various tests and a dark I-V performance check.

Radiometers for radon concentration in air

International Nuclear Information System (INIS)

Bartak, J.; Machaj, B.; Pienkos, J.P.

2002-01-01

Constant grow of science and technology stimulates development of new improved measuring tools. New measuring demand arise also in radon concentration measurements. Varying rock stress and rock cracks influencing radon emanation encouraged research aimed at use of this phenomenon to predict crumps of mine formation among others based on variation of radon emanation. A measuring set was developed in the Institute of Nuclear Chemistry and Technology enabling long term monitoring of radon concentration in mine bore-hole. The set consists probe and probe controller. Detection threshold of the probe is 230 Bq/m 3 . The set can operate in the environment with methane explosion hazard. A radiometer employing Lucas cell as radiation detector for radon concentration in air was also developed its detection threshold is approx. 10 Bq/m 3 . Replaceable Lucas cell of the radiometer allows for measurement of high as well as low radon concentration in short time interval. (author)

Experimental characterization of Fresnel-Köhler concentrators

Science.gov (United States)

Zamora, Pablo; Benítez, Pablo; Mohedano, Rubén; Cvetković, Aleksandra; Vilaplana, Juan; Li, Yang; Hernández, Maikel; Chaves, Julio; Miñano, Juan C.

2012-01-01

Most cost-effective concentrated photovoltaics (CPV) systems are based on an optical train comprising two stages, the first being a Fresnel lens. Among them, the Fresnel-Köhler (FK) concentrator stands out owing to both performance and practical reasons. We describe the experimental measurements procedure for FK concentrator modules. This procedure includes three main types of measurements: electrical efficiency, acceptance angle, and irradiance uniformity at the solar cell plane. We have collected here the performance features of two different FK prototypes (ranging different f-numbers, concentration ratios, and cell sizes). The electrical efficiencies measured in both prototypes are high and fit well with the models, achieving values up to 32.7% (temperature corrected, and with no antireflective coating on SOE or POE surfaces) in the best case. The measured angular transmission curves show large acceptance angles, again perfectly matching the expected values [measured concentration acceptance product (CAP) values over 0.56]. The irradiance pattern on the cell (obtained with a digital camera) shows an almost perfectly uniform distribution, as predicted by raytrace simulations. All these excellent on-sun results confirm the FK concentrator as a potentially cost-effective solution for the CPV market.

Concentration of trace elements in marine organisms

International Nuclear Information System (INIS)

Ishii, Takaaki; Suzuki, Hamaji; Iimura, Mitsue; Koyanagi, Taku

1976-01-01

Information on the quality and quantity of stable trace elements in marine environments is frequently required to analyze the radioecological behavior of radionuclides released from nuclear facilities into the sea. In the present work, special attention was concentrated in determination of stable Mn, Fe, Co, Zn, Rb and Cs in marine organisms to estimate the concentration factors for these elements and corresponding radionuclides. Marine organisms (fishes, marine invertebrates and seaweeds) were collected at the seashore of Ibaragi prefecture and provided for chemical analysis after dry-ashing and wet-ashing. Atomic absorption spectrophotometry and neutron activation analysis were applied to determine the concentration of elements. The concentration of stable elements in fish muscle was independent on species of the fishes though slightly higher trends were observed in ''Usumebaru'', Sebastes nivosus for Cs, ''Ishimochi'', Nibea mitsukurii for Zn and Fe compared with other species. The concentration of Co, Zn and Fe in muscle of marine invertebrates was one order of magnitude higher than fish muscles especially in shellfishes for Co. Seaweeds showed peculiar species specificity for the concentration of stable trace elements and remarkable differences was observed between the species even among the same genus. (auth.)

Current Status of Concentrator Photovoltaic (CPV) Technology

Energy Technology Data Exchange (ETDEWEB)

Philipps, Simon P. [Fraunhofer Inst. for Solar Energy Systems ISE, Freiburg (Germany); Bett, Andreas W. [Fraunhofer Inst. for Solar Energy Systems ISE, Freiburg (Germany); Horowitz, Kelsey [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kurtz, Sarah [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2015-12-01

This report summarizes the status of the concentrator photovoltaic (CPV) market and industry as well as current trends in research and technology. This report is intended to guide research agendas for Fraunhofer ISE, the National Renewable Energy Laboratory (NREL), and other R&D organizations. Version 1.1 of this report includes recent progress in CPV. The recent record module efficiency of 38.9% at Concentrator Standard Test Conditions (CSTC) is an impressive result, demonstrating the continuing opportunity for CPV technology to improve. 38.9% at Concentrator Standard Test Conditions (CSTC) is an impressive result, demonstrating the continuing opportunity for CPV technology to improve. 38.9% at Concentrator Standard Test Conditions (CSTC) is an impressive result, demonstrating the continuing opportunity for CPV technology to improve. 38.9% at Concentrator Standard Test Conditions (CSTC) is an impressive result, demonstrating the continuing opportunity for CPV technology to improve.

Food chain model to predict westslope cutthroat trout ovary selenium concentrations from water concentrations in the Elk Valley, BC

International Nuclear Information System (INIS)

Orr, P.; Wiramanaden, C.; Franklin, W.; Fraser, C.

2010-01-01

The 5 coal mines operated by Teck Coal Ltd. in British Columbia's Elk River watershed release selenium during weathering of mine waste rock. Since 1966, several field studies have been conducted in which selenium concentrations in biota were measured. They revealed that tissue concentrations are higher in aquatic biota sampled in lentic compared to lotic habitats of the watershed with similar water selenium concentrations. Two food chain models were developed based on the available data. The models described dietary selenium accumulation in the ovaries of lotic versus lentic westslope cutthroat trout (WCT), a valued aquatic resource in the Elk River system. The following 3 trophic transfer relationships were characterized for each model: (1) water to base of the food web, (2) base of the food web to benthic invertebrates, and (3) benthic invertebrates to WCT ovaries. The lotic and lentic models combined the resulting equations for each trophic transfer relationships to predict WCT ovary concentrations from water concentrations. The models were in very good agreement with the available data, despite fish movement and the fact that composite benthic invertebrate sample data were only an approximation of the feeding preferences of individual fish. Based on the observed rates of increase in water selenium concentrations throughout the watershed, the models predicted very small/slow increases in WCT ovary concentrations with time.

HYPOLIPEMIC THERAPY AND LOW SERUM CHOLESTEROL CONCENTRATION

Directory of Open Access Journals (Sweden)

Vladmila Bojanic

2004-01-01

Full Text Available Low concentration of plasma lipoproteins (hypolipoproteinemia presents decreasing concentrations of all or particular lipids components. Classification of hypolipoproteinemia (hypoLP divides them into: primary (hereditary and secondary. Primary hipoLP are rare diseases and their main characteristic is disorder of apolipoproteins synthesis, which leads to low serum cholesterol concentration. Secondary hipoLP are presented in many diseases. They have diagnostic, prognostic significance and present good therapeutic marker. However, modern therapeutic approaches for aggressive lipid lowering pointed out many questions about physiological limits for cholesterol lowering. These approaches, also, open many questions about consequences of low serum concentration of total cholesterol and triglicerides.

Dynamic thermal analysis of a concentrated photovoltaic system

Science.gov (United States)

Avrett, John T., II; Cain, Stephen C.; Pochet, Michael

2012-02-01

Concentrated photovoltaic (PV) technology represents a growing market in the field of terrestrial solar energy production. As the demand for renewable energy technologies increases, further importance is placed upon the modeling, design, and simulation of these systems. Given the U.S. Air Force cultural shift towards energy awareness and conservation, several concentrated PV systems have been installed on Air Force installations across the country. However, there has been a dearth of research within the Air Force devoted to understanding these systems in order to possibly improve the existing technologies. This research presents a new model for a simple concentrated PV system. This model accurately determines the steady state operating temperature as a function of the concentration factor for the optical part of the concentrated PV system, in order to calculate the optimum concentration that maximizes power output and efficiency. The dynamic thermal model derived is validated experimentally using a commercial polysilicon solar cell, and is shown to accurately predict the steady state temperature and ideal concentration factor.

Error exponents for entanglement concentration

International Nuclear Information System (INIS)

Hayashi, Masahito; Koashi, Masato; Matsumoto, Keiji; Morikoshi, Fumiaki; Winter, Andreas

2003-01-01

Consider entanglement concentration schemes that convert n identical copies of a pure state into a maximally entangled state of a desired size with success probability being close to one in the asymptotic limit. We give the distillable entanglement, the number of Bell pairs distilled per copy, as a function of an error exponent, which represents the rate of decrease in failure probability as n tends to infinity. The formula fills the gap between the least upper bound of distillable entanglement in probabilistic concentration, which is the well-known entropy of entanglement, and the maximum attained in deterministic concentration. The method of types in information theory enables the detailed analysis of the distillable entanglement in terms of the error rate. In addition to the probabilistic argument, we consider another type of entanglement concentration scheme, where the initial state is deterministically transformed into a (possibly mixed) final state whose fidelity to a maximally entangled state of a desired size converges to one in the asymptotic limit. We show that the same formula as in the probabilistic argument is valid for the argument on fidelity by replacing the success probability with the fidelity. Furthermore, we also discuss entanglement yield when optimal success probability or optimal fidelity converges to zero in the asymptotic limit (strong converse), and give the explicit formulae for those cases

Novel concept of nonimaging single reflection solar energy concentrator

Energy Technology Data Exchange (ETDEWEB)

Gasparovsky, D.

2004-07-01

Many solar applications require temperatures higher than those that can be achieved by common flat-plate collectors. Temperatures over 100 C are necessary e.g. for industrial process heat. Such temperatures can be obtained by means of solar energy concentrators. Advantages of concentrating the solar radiation can bring in addition to higher temperatures also decrease in heat losses and material savings due to smaller size of absorber, if taking into account that costs for material absorber per square meter can be possibly higher than costs for e.g. concentrating mirrors. On the other hand, using the concentration, two other kinds of losses will raise: losses of diffuse radiation and optical losses. There exist a variety of solar energy concentrators for different purposes. For lowtemperature applications, inexpensive concentrators of diffuse radiation can be used. For these concentrators, acceptance angle A defines the ability to concentrate the diffuse radiation and also its concentration factor C. To this class of concentrators belongs e.g. nonimaging types like CPC (Compound Parabolic Concentrator), V-trough types, cylindrical concentrators etc. This paper deals with development of a new type of concentrator, novel concept of which is based on functionality of CPC by means of flat mirrors, primarily designed for needs of SME's (Small and Medium Enterprises). The CLON project is being ellaborated under the 5th Framework Programme of the EU. (orig.)

Maternal exposure to metals—Concentrations and predictors of exposure

International Nuclear Information System (INIS)

Callan, A.C.; Hinwood, A.L.; Ramalingam, M.; Boyce, M.; Heyworth, J.; McCafferty, P.; Odland, J.Ø.

2013-01-01

A variety of metals are important for biological function but have also been shown to impact health at elevated concentrations, whereas others have no known biological function. Pregnant women are a vulnerable population and measures to reduce exposure in this group are important. We undertook a study of maternal exposure to the metals, aluminium, arsenic, copper, cobalt, chromium, lithium, manganese, nickel, selenium, tin, uranium and zinc in 173 participants across Western Australia. Each participant provided a whole blood and urine sample, as well as drinking water, residential soil and dust samples and completed a questionnaire. In general the concentrations of metals in all samples were low with the notable exception of uranium (blood U mean 0.07 µg/L, range <0.01–0.25 µg/L; urinary U mean 0.018 µg/g creatinine, range <0.01–0.199 µg/g creatinine). Factors that influenced biological concentrations were consumption of fish which increased urinary arsenic concentrations, hobbies (including mechanics and welding) which increased blood manganese concentrations and iron/folic acid supplement use which was associated with decreased concentrations of aluminium and nickel in urine and manganese in blood. Environmental concentrations of aluminium, copper and lithium were found to influence biological concentrations, but this was not the case for other environmental metals concentrations. Further work is underway to explore the influence of diet on biological metals concentrations in more detail. The high concentrations of uranium require further investigation. -- Highlights: • High concentrations of uranium with respect to international literature. • Environmental concentrations of Al, Cu and Li influenced urinary concentrations. • Exposure to mechanics/welding hobbies increased blood Mn concentrations. • Iron/Folic acid supplements reduced biological concentrations of Al, Ni and Mn

Maternal exposure to metals—Concentrations and predictors of exposure

Energy Technology Data Exchange (ETDEWEB)

Callan, A.C., E-mail: a.callan@ecu.edu.au [Centre for Ecosystem Management, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA 6027 (Australia); Hinwood, A.L.; Ramalingam, M.; Boyce, M. [Centre for Ecosystem Management, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA 6027 (Australia); Heyworth, J. [School Population Health, The University of Western Australia, 35 Stirling Highway Crawley, WA 6009 (Australia); McCafferty, P. [ChemCentre, PO Box 1250, Bentley, WA 6983 (Australia); Odland, J.Ø. [Department of Community Medicine, University of Tromsø, N-9037 Tromsø (Norway)

2013-10-15

A variety of metals are important for biological function but have also been shown to impact health at elevated concentrations, whereas others have no known biological function. Pregnant women are a vulnerable population and measures to reduce exposure in this group are important. We undertook a study of maternal exposure to the metals, aluminium, arsenic, copper, cobalt, chromium, lithium, manganese, nickel, selenium, tin, uranium and zinc in 173 participants across Western Australia. Each participant provided a whole blood and urine sample, as well as drinking water, residential soil and dust samples and completed a questionnaire. In general the concentrations of metals in all samples were low with the notable exception of uranium (blood U mean 0.07 µg/L, range <0.01–0.25 µg/L; urinary U mean 0.018 µg/g creatinine, range <0.01–0.199 µg/g creatinine). Factors that influenced biological concentrations were consumption of fish which increased urinary arsenic concentrations, hobbies (including mechanics and welding) which increased blood manganese concentrations and iron/folic acid supplement use which was associated with decreased concentrations of aluminium and nickel in urine and manganese in blood. Environmental concentrations of aluminium, copper and lithium were found to influence biological concentrations, but this was not the case for other environmental metals concentrations. Further work is underway to explore the influence of diet on biological metals concentrations in more detail. The high concentrations of uranium require further investigation. -- Highlights: • High concentrations of uranium with respect to international literature. • Environmental concentrations of Al, Cu and Li influenced urinary concentrations. • Exposure to mechanics/welding hobbies increased blood Mn concentrations. • Iron/Folic acid supplements reduced biological concentrations of Al, Ni and Mn.

Oxygen concentration inside a functioning photosynthetic cell.

Science.gov (United States)

Kihara, Shigeharu; Hartzler, Daniel A; Savikhin, Sergei

2014-05-06

The excess oxygen concentration in the photosynthetic membranes of functioning oxygenic photosynthetic cells was estimated using classical diffusion theory combined with experimental data on oxygen production rates of cyanobacterial cells. The excess oxygen concentration within the plesiomorphic cyanobacterium Gloeobactor violaceus is only 0.025 μM, or four orders of magnitude lower than the oxygen concentration in air-saturated water. Such a low concentration suggests that the first oxygenic photosynthetic bacteria in solitary form could have evolved ∼2.8 billion years ago without special mechanisms to protect them against reactive oxygen species. These mechanisms instead could have been developed during the following ∼500 million years while the oxygen level in the Earth's atmosphere was slowly rising. Excess oxygen concentrations within individual cells of the apomorphic cyanobacteria Synechocystis and Synechococcus are 0.064 and 0.25 μM, respectively. These numbers suggest that intramembrane and intracellular proteins in isolated oxygenic photosynthetic cells are not subjected to excessively high oxygen levels. The situation is different for closely packed colonies of photosynthetic cells. Calculations show that the excess concentration within colonies that are ∼40 μm or larger in diameter can be comparable to the oxygen concentration in air-saturated water, suggesting that species forming colonies require protection against reactive oxygen species even in the absence of oxygen in the surrounding atmosphere. Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Luminescent solar concentrators with fiber geometry.

Science.gov (United States)

Edelenbosch, Oreane Y; Fisher, Martyn; Patrignani, Luca; van Sark, Wilfried G J H M; Chatten, Amanda J

2013-05-06

The potential of a fibre luminescent solar concentrator has been explored by means of both analytical and ray-tracing techniques. Coated fibres have been found to be more efficient than homogeneously doped fibres, at low absorption. For practical fibres concentration is predicted to be linear with fibre length. A 1 m long, radius 1 mm, fibre LSC doped with Lumogen Red 305 is predicted to concentrate the AM1.5 g spectrum up to 1100 nm at normal incidence by ~35 x. The collection efficiency under diffuse and direct irradiance in London has been analysed showing that, even under clear sky conditions, in winter the diffuse contribution equals the direct.

Atmospheric concentration of 210Pb in East Asia

International Nuclear Information System (INIS)

Doi, T.; Sato, S.; Sato, J.

2003-01-01

Concentrations of 210 Pb and 7 Be in the surface air were measured at Tsukuba, Japan. The air concentrations of 210 Pb and 7 Be ranged from 0.2 to 0.7 mBq/m 3 and from 1 to 6 mBq/m 3 , respectively. Seasonal variation of 210 Pb concentration was similar to that of 7 Be, showing a 'two-peak' variation pattern: high concentrations appeared in spring and fall. Atmospheric concentrations of 210 Pb and their variations over Urumqi, Lanzhou and Baotou, cities located inland area of the Eurasian Continent, were observed. The monthly average concentrations ranged from 0.27 to 4.57 mBq/m 3 . The concentrations over these cities in winter were several times higher than that observed at Tsukuba, and the range of variation was also larger. The variations in concentration over the 3 localities resembled well with each other, showing the similar seasonal variation pattern: low concentration appeared in summer and high in winter. This variation pattern was different from that observed at Tsukuba. The variations in concentration over the Eurasian Continent, where precipitation is extremely smaller than that of Japan, inversely correlated quite well with the variation in the precipitation. The atmospheric concentrations of 210 Pb ranged from 0.9 to 4.6 mBq/m 3 at Beijing and from 1.4 to 7.8 mBq/m 3 at Chengdu and from 0.5 to 4.9 mBq/m 3 at Seoul, respectively, which were in the similar level to those observed previously in the inland area of the Eurasian Continent. Seasonal variations of the 210 Pb concentration showed the 'one-peak' variation pattern: the maximum levels were recorded in winter season. Small additional rises in the atmospheric 210 Pb concentrations observed in the period from spring to fall seasons may be due to complicated meteorology with high pressure systems at Beijing and Seoul and due to the topographical situation at Chengdu. Long range transport from the Eurasian Continent to the Japanese Islands was also assessed. The air mass from continent reached the

Effect of breed on plasma endothelin-1 concentration, plasma renin activity, and serum cortisol concentration in healthy dogs

DEFF Research Database (Denmark)

Höglund, K.; Lequarré, A.-S.; Ljungvall, I.

2016-01-01

BACKGROUND: There are breed differences in several blood variables in healthy dogs. OBJECTIVE: Investigate breed variation in plasma endothelin-1 (ET-1) concentration, plasma renin activity, and serum cortisol concentration. ANIMALS: Five-hundred and thirty-one healthy dogs of 9 breeds examined...... at 5 centers (2-4 breeds/center). METHODS: Prospective observational study. Circulating concentrations of ET-1 and cortisol, and renin activity, were measured using commercially available assays. Absence of organ-related or systemic disease was ensured by thorough clinical investigations, including...

Technical Performance and Clinical Effectiveness of Drop Type With Adjustable Concentrator-Cell Free and Concentrated Ascites Reinfusion Therapy.

Science.gov (United States)

Yamada, Yosuke; Harada, Makoto; Yamaguchi, Akinori; Kobayashi, Yasuko; Chino, Takashi; Minowa, Takashi; Kosuge, Takashi; Tsukada, Wataru; Hashimoto, Koji; Kamijo, Yuji

2017-12-01

Cell-free and concentrated ascites reinfusion therapy (CART) is a very useful treatment method for refractory ascites but is difficult for many hospitals to employ due to its need for specialized equipment. We have therefore developed drop-type with adjustable concentrator CART (DC-CART) that uses a drop-type filtration mechanism and requires only a simple pump and pressure monitor for its concentration process. Easy adjustment of ascites concentration is possible through a recirculation loop, and filter membrane washing is aided by DC-CART's external pressure-type filtration to enable the processing of any quality or quantity of ascites. Moreover, the absence of a roller pump before filtration avoids inflammatory substance release from compressed cells. A total of 268 sessions of DC-CART using ascites from 98 patients were performed with good clinical results at our hospitals between January 2012 and June 2016. This report presents the detailed methods of DC-CART and summarizes its clinical effectiveness using patient ascites and blood data obtained from 59 sessions between March 2015 and February 2016. This novel technique successfully processed refractory ascites in numerous diseases with no serious adverse events. DC-CART could concentrate large amounts of ascites (from median weight: 4900 g [max: 20 200 g] to median weight: 695 g; median concentration ratio: 7.4), and a high amount of protein (median weight: 73 g [max: 294 g]) could be reinfused. Serum albumin levels were significantly increased (P = 0.010) and kidney function and systemic hemodynamics were well maintained in treated subjects. Additional concentration of ascites and adjustment of ascites volume were easily performed by recirculation (from median weight: 615 g to median weight: 360 g; median concentration ratio: 1.5). Time was needed during DC-CART for filter membrane cleaning, especially for viscous ascites. Overall, DC-CART represents a safe and useful treatment method for various forms

Serum testosterone concentrations in men with alcoholic cirrhosis

DEFF Research Database (Denmark)

Gluud, C

1987-01-01

Median serum testosterone concentration of men with alcoholic cirrhosis (n = 216) did not differ significantly from normal controls (n = 51), but serum testosterone concentrations varied by a factor 43.9 in patients compared to 3.2 in controls (P less than .001). Nineteen percent of the patients...... had serum testosterone concentrations above 30 nmol/L. Serum concentrations of sex-hormone-binding globulin (SHBG) were significantly (P less than .001) raised, and serum concentrations of calculated nonprotein-bound and non-SHBG-bound testosterone were significantly (P less than .001) decreased...... in patients compared to normal control values. A number of background variables were analyzed with reference to serum testosterone concentrations by means of multiple regression techniques after having divided the patients into groups (A, B, C) with decreasing liver function by a modification of the Child...

Is lowering reducing sugars concentration in French fries an effective measure to reduce acrylamide concentration in food service establishments?

Science.gov (United States)

Sanny, M; Jinap, S; Bakker, E J; van Boekel, M A J S; Luning, P A

2012-12-01

The objective of this study was to obtain insight into the actual effectiveness of lowering reducing sugars concentration in par-fried potato strips on the concentration and variation of acrylamide in French fries prepared in real-life situations in food service establishments. Acrylamide, frying time, frying temperature, and reducing sugars were measured and characteristics of fryers were recorded. Data showed that the use of par-fried potato strips with lower concentrations of reducing sugars than the commonly used potato strips was an effective measure to reduce acrylamide concentrations in French fries prepared under standardised frying conditions. However, there was still large variation in the acrylamide concentrations in French fries, although the variation in reducing sugars concentrations in low and normal types of par-fried potato strips was very small and the frying conditions were similar. Factors that could affect the temperature-time profile of frying oil were discussed, such as setting a lower frying temperature at the end than at the start of frying, product/oil ratio and thawing practice. These need to be controlled in daily practice to reduce variation in acrylamide. Copyright © 2012 Elsevier Ltd. All rights reserved.

Serum magnesium concentration in drug-addicted patients.

Science.gov (United States)

Karakiewicz, Beata; Kozielec, Tadeusz; Brodowski, Jacek; Chlubek, Dariusz; Noceń, Iwona; Starczewski, Andrzej; Brodowska, Agnieszka; Laszczyńska, Maria

2007-03-01

Drug addiction is a complex problem which leads to many somatic, psychic and social diseases. It is accompanied by the disturbed metabolism of various macro and micronutrients. The aim of this study was to assess serum magnesium concentration in drug-addicted patients and analyze whether Human Immunodeficiency Virus (HIV) infection and methadone treatment affect the level of serum magnesium in these patients. The examination was conducted in a group of 83 people - patients of Szczecin-Zdroje Psychiatric Hospital (Poland). They were 21 to 49 years old, and the mean age was 32 +/- 7 years. The control group consisted of 81 healthy individuals. Flame atomic-absorption spectrometry method was used to determine the magnesium concentration. The total serum magnesium concentration was calculated for the whole patient group, subgroups of women and men, a subgroup of people infected with HIV, and a subgroup receiving methadone substitution treatment. How magnesium behaves depending on age and addiction period, was checked. The mean concentration of magnesium in blood serum of the patients examined was 0.57 mmol/L, which was significantly lower than in the control group. In the subgroup of men it was 0.57 mmol/L, and in the subgroup of women - 0.55 mmol/L; the differences were not statistically significant. In the patient group nobody had the appropriate magnesium concentration in blood serum. No significant correlation was found between the magnesium concentration, age of the patients and addiction period. In the subgroup of seropositive people the mean concentration of magnesium was 0.55 mmol/L, and in the subgroup of non-infected patients - 0.58 mmol/L; the difference was not statistically significant. The mean concentration of magnesium in the subgroup treated with methadone was 0.59 mmol/L, and in the subgroup not involved in this type of therapy - 0.55 mmol/L; it was not a statistically significant difference.

Concentrations of Indicator Organisms

Data.gov (United States)

U.S. Environmental Protection Agency — It is a compilation of organism concentrations of 16 sampling events conducted between July 2015 and February 2016. It also includes statistical analysis such as...

A high-gain, compact, nonimaging concentrator: RXI.

Science.gov (United States)

Miñano, J C; Gonźlez, J C; Benítez, P

1995-12-01

The design procedure of a new nonimaging concentrator (called an RXI) is explained. Rays that impinge on the concentrator aperture, within the acceptance angle, are directed to the receiver by means of one refraction, one reflection, and one total internal reflection. The concentrator can be made as a single dielectric piece (in which the receiver is immersed) whose aspect ratio (thickness/aperture diameter) is close to 1/3. Ray-tracing analysis of a rotational symmetric RXI shows total transmissions of greater than 94.5% (no absorption or reflection losses are considered) when the acceptance angle of the incoming rays is small (<3°) and when the receiver area is the smallest possible (maximal concentration.).

Nondestructive measurement for radionuclide concentration distribution in soil column

International Nuclear Information System (INIS)

Ogawa, Hiromichi; Ohnuki, Toshihiko; Yamamoto, Tadatoshi; Wadachi, Yoshiki

1985-01-01

A nondestructive method has been studied for determining the concentration of radionuclide (Cs-137) distributed in a soil column. The concentration distribution was calculated from the counting rate distribution using the efficiency matrix of a detector. The concentration distribution obtained by this method, with measuring efficiencies of theoretical calculation, coincides well with that obtained by the destructive sampling method. This method is, therefore, found to be effective for the measurement of one dimensional concentration distribution. The measuring limit of this method is affected not only by the radionuclide concentration but also by the shape of concentration distribution in a soil column and also by the way it is divided into concentration blocks. It is found that, the radioactive concentration up to 2.6 x 10 -4 μCi/g (9.62 Bq/g), and also the distribution up to where the concentration reduces to half at every 1 cm of depth, can be measured by this system. The concentration blocks can be divided into 1 cm of thickness as a minimum value. (author)

Resonance-shifting luminescent solar concentrators

Energy Technology Data Exchange (ETDEWEB)

Giebink, Noel Christopher; Wiederrecht, Gary P.; Wasielewski, Michael R.

2018-01-23

An optical system and method to overcome luminescent solar concentrator inefficiencies by resonance-shifting, in which sharply directed emission from a bi-layer cavity into a glass substrate returns to interact with the cavity off-resonance at each subsequent reflection, significantly reducing reabsorption loss en route to the edges. In one embodiment, the system comprises a luminescent solar concentrator comprising a transparent substrate, a luminescent film having a variable thickness; and a low refractive index layer disposed between the transparent substrate and the luminescent film.

A Twitter-based survey on marijuana concentrate use.

Science.gov (United States)

Daniulaityte, Raminta; Zatreh, Mussa Y; Lamy, Francois R; Nahhas, Ramzi W; Martins, Silvia S; Sheth, Amit; Carlson, Robert G

2018-04-11

The purpose of this paper is to analyze characteristics of marijuana concentrate users, describe patterns and reasons of use, and identify factors associated with daily use of concentrates among U.S.-based cannabis users recruited via a Twitter-based online survey. An anonymous Web-based survey was conducted in June 2017 with 687 U.S.-based cannabis users recruited via Twitter-based ads. The survey included questions about state of residence, socio-demographic characteristics, and cannabis use including marijuana concentrates. Multiple logistic regression analyses were conducted to identify characteristics associated with lifetime and daily use of marijuana concentrates. Almost 60% of respondents were male, 86% were white, and the mean age was 43.0 years. About 48% reported marijuana concentrate use. After adjusting for multiple testing, significant predictors of concentrate use included: living in "recreational" (AOR = 2.04; adj. p = .042) or "medical, less restrictive" (AOR = 1.74; adj. p = .030) states, being younger (AOR = 0.97, adj. p = .008), and daily herbal cannabis use (AOR = 2.57, adj. p = .008). Out of 329 marijuana concentrate users, about 13% (n = 44) reported daily/near daily use. Significant predictors of daily concentrate use included: living in recreational states (AOR = 3.59, adj. p = .020) and using concentrates for therapeutic purposes (AOR = 4.34, adj. p = .020). Living in states with more liberal marijuana policies is associated with greater likelihood of marijuana concentrate use and with more frequent use. Characteristics of daily users, in particular, patterns of therapeutic use warrant further research with community-recruited samples. Copyright © 2018 Elsevier B.V. All rights reserved.

Refractive Secondary Solar Concentrator Being Designed and Developed

Science.gov (United States)

Macosko, Robert P.; Donovan, Richard M.

1998-01-01

As the need for achieving super high temperatures (2000 K and above) in solar heat receivers has developed so has the need for secondary concentrators. These concentrators refocus the already highly concentrated solar energy provided by a primary solar collector, thereby significantly reducing the light entrance aperture of the heat receiver and the resulting infrared radiation heat loss from the receiver cavity. Although a significant amount of research and development has been done on nonimaging hollow reflective concentrators, there has been no other research or development to date on solid, single crystal, refractive concentrators that can operate at temperatures above 2000 K. The NASA Lewis Research Center recently initiated the development of single-crystal, optically clear, refractive secondary concentrators that, combined with a flux extractor, offer a number of significant advantages over the more conventional, hollow, reflective concentrators at elevated temperatures. Such concentrators could potentially provide higher throughput (efficiency), require no special cooling device, block heat receiver material boiloff from the receiver cavity, provide for flux tailoring in the cavity via the extractor, and potentially reduce infrared heat loss via an infrared block coating.The many technical challenges of designing and fabricating high-temperature refractive secondary concentrators and flux extractors include identifying optical materials that can survive the environment (high-temperature, vacuum and/or hydrogen atmosphere), developing coatings for enhanced optical and thermal performance, and developing crystal joining techniques and hardware that can survive launch loads.

Raltegravir cerebrospinal fluid concentrations in HIV-1 infection.

Directory of Open Access Journals (Sweden)

Aylin Yilmaz

2009-09-01

Full Text Available Raltegravir is an HIV-1 integrase inhibitor currently used in treatment-experienced HIV-1-infected patients resistant to other drug classes. In order to assess its central nervous system penetration, we measured raltegravir concentrations in cerebrospinal fluid (CSF and plasma in subjects receiving antiretroviral treatment regimens containing this drug.Raltegravir concentrations were determined by liquid chromatography tandem mass spectrometry in 25 paired CSF and plasma samples from 16 HIV-1-infected individuals. The lower limit of quantitation was 2.0 ng/ml for CSF and 10 ng/ml for plasma.Twenty-four of the 25 CSF samples had detectable raltegravir concentrations with a median raltegravir concentration of 18.4 ng/ml (range, <2.0-126.0. The median plasma raltegravir concentration was 448 ng/ml (range, 37-5180. CSF raltegravir concentrations correlated with CSF:plasma albumin ratios and CSF albumin concentrations.Approximately 50% of the CSF specimens exceeded the IC(95 levels reported to inhibit HIV-1 strains without resistance to integrase inhibitors. In addition to contributing to control of systemic HIV-1 infection, raltegravir achieves local inhibitory concentrations in CSF in most, but not all, patients. Blood-brain and blood-CSF barriers likely restrict drug entry, while enhanced permeability of these barriers enhances drug entry.

Plasma concentration of ionized calcium in healthy iguanas.

Science.gov (United States)

Dennis, P M; Bennett, R A; Harr, K E; Lock, B A

2001-08-01

To measure plasma concentration of ionized calcium in healthy green iguanas. Prospective study. 9 juvenile and 21 (10 male, 11 female) adult iguanas. Blood samples were obtained from each iguana, and plasma calcium, glucose, phosphorus, uric acid, total protein, albumin, globulin, potassium, and ionized calcium concentrations, aspartate transaminase (AST) activity, and pH were measured. Heparinized blood was used for measurement of ionized calcium concentration and blood pH. A CBC was also performed to assess the health of the iguanas. Significant differences were not detected among the 3 groups (juveniles, males, and females) with regard to ionized calcium concentration. Mean ionized calcium concentration measured in blood was 1.47 +/- 0.105 mmol/L. Significant differences were detected between juveniles and adults for values of phosphorus, glucose, total protein, albumin, globulin, and AST activity. Ionized calcium concentration provides a clinical measurement of the physiologically active calcium in circulation. Evaluation of physiologically active calcium in animals with suspected calcium imbalance that have total plasma calcium concentrations within reference range or in gravid animals with considerably increased total plasma calcium concentrations is vital for determining a therapeutic plan. Accurate evaluation of calcium status will provide assistance in the diagnosis of renal disease and seizures and allow for better evaluation of the health status of gravid female iguanas.

An investigation of factors influencing indoor radon concentrations

International Nuclear Information System (INIS)

Majborn, B.; Soerensen, A.; Nielsen, S.P.; Boetter-Jensen, L.

1988-05-01

Variations in indoor radon concentrations and some influencing factors have been studied during a two-year period (1986-1987) in 16 almost identical single-family houses.The annual average radon concentration in the houses varied from about 50 to about 400 Bq/m 3 . Variations in soil characteristics and radon concentration in soil gas could not be directly related to the variations of the average indoor radon concentrations. Most of the houses showed a ''normal'' seasonal variation of the radon concentration with a maximum in the winter and minimum in the summer. A deviating seasonal variation was found in three of the houses. Hourly data obtained in one unoccupied house during a period of 2-1/2 months showed no or only weak correlations between the indoor radon concentration and meteorological factors. However, for most of the houses, the seasonal variation of the indoor radon concentration was well correlated with the average indoor-outdoor temperature difference on a 2-month basis. It was demonstrated that the radon concentration can be strongly reduced in the Risoe houses if a district-heating duct, which is connected to all the houses, is ventilated, so that a slightly lowered pressure is maintained in the duct. 5 taps., 24 ill. (author)

Raltegravir cerebrospinal fluid concentrations in HIV-1 infection.

Science.gov (United States)

Yilmaz, Aylin; Gisslén, Magnus; Spudich, Serena; Lee, Evelyn; Jayewardene, Anura; Aweeka, Francesca; Price, Richard W

2009-09-01

Raltegravir is an HIV-1 integrase inhibitor currently used in treatment-experienced HIV-1-infected patients resistant to other drug classes. In order to assess its central nervous system penetration, we measured raltegravir concentrations in cerebrospinal fluid (CSF) and plasma in subjects receiving antiretroviral treatment regimens containing this drug. Raltegravir concentrations were determined by liquid chromatography tandem mass spectrometry in 25 paired CSF and plasma samples from 16 HIV-1-infected individuals. The lower limit of quantitation was 2.0 ng/ml for CSF and 10 ng/ml for plasma. Twenty-four of the 25 CSF samples had detectable raltegravir concentrations with a median raltegravir concentration of 18.4 ng/ml (range, <2.0-126.0). The median plasma raltegravir concentration was 448 ng/ml (range, 37-5180). CSF raltegravir concentrations correlated with CSF:plasma albumin ratios and CSF albumin concentrations. Approximately 50% of the CSF specimens exceeded the IC(95) levels reported to inhibit HIV-1 strains without resistance to integrase inhibitors. In addition to contributing to control of systemic HIV-1 infection, raltegravir achieves local inhibitory concentrations in CSF in most, but not all, patients. Blood-brain and blood-CSF barriers likely restrict drug entry, while enhanced permeability of these barriers enhances drug entry.

Complementary construction of ideal nonimaging concentrators and its applications.

Science.gov (United States)

Gordon, J M

1996-10-01

A construction principle for ideal nonimaging concentrators based on the complementary edge rays outside the nominal field of view is presented, with illustrations for the trumpet, compound parabolic concentrator, and compound hyperbolic concentrator. A simple string construction for the trumpet concentrator is shown to follow from this observation-the trumpet having been the one ideal concentrator for which no string-construction method had previously been noted. An application of these observations for solar concentrator design when nonisothermal receivers are advantageous is also presented.

Beam-Forming Concentrating Solar Thermal Array Power Systems

Science.gov (United States)

Cwik, Thomas A. (Inventor); Dimotakis, Paul E. (Inventor); Hoppe, Daniel J. (Inventor)

2016-01-01

The present invention relates to concentrating solar-power systems and, more particularly, beam-forming concentrating solar thermal array power systems. A solar thermal array power system is provided, including a plurality of solar concentrators arranged in pods. Each solar concentrator includes a solar collector, one or more beam-forming elements, and one or more beam-steering elements. The solar collector is dimensioned to collect and divert incoming rays of sunlight. The beam-forming elements intercept the diverted rays of sunlight, and are shaped to concentrate the rays of sunlight into a beam. The steering elements are shaped, dimensioned, positioned, and/or oriented to deflect the beam toward a beam output path. The beams from the concentrators are converted to heat at a receiver, and the heat may be temporarily stored or directly used to generate electricity.

21 CFR 155.191 - Tomato concentrates.

Science.gov (United States)

2010-04-01

... Tomato concentrates. (a) Identity—(1) Definition. Tomato concentrates are the class of foods each of... greater in length. (c) Blemishes, such as dark brown or black particles (specks)—not more than four exceed...; place a U.S. No. 12 screen (1.68 millimeters (0.066 inch) openings) over the sink drain; transfer the...

Assessment of indoor radon gas concentration change of college

Energy Technology Data Exchange (ETDEWEB)

Park, Hoon Hee; Jeong, Eui Hwan; Kim, Hak Jae; Lyu, Kang Yeul [Dept. of of Radiological Technology, Shingu College, Seongnam (Korea, Republic of); Lee, Ju Young [Dept. of Radiological Technology, Songho College, Hoengseong (Korea, Republic of)

2017-03-15

The purpose of this study was to assess the impact by comparing the concentration of indoor radon and look for ways to lower the concentration of indoor radon gas measurements of three variables, the year of completion, volume of the building and ventilation. Measurement target is six classrooms on the sixth floor of building that was constructed in 1973 and was extended in 2011. Selected classroom's volume is different. Four classrooms were selected to compare the radon concentration in accordance with the year of completion, Classrooms that is same year of completion were selected to compare the radon concentration in accordance with the volume, six classroom was performed closure and ventilation to compare radon concentration according to ventilation. Radon concentrations in accordance with the year of building completion showed a high concentration of radon in a building recently built. Also, Radon concentration in volume is high the smaller the volume. Radon concentration change according to ventilation showed a reduction of about 80% when the ventilation than during closing. Especially, The radon concentrations were high detected while the recently year of building completion and the smaller volume. Ventilation of the three variables is considered that can be expected to exposure reduction effect by radon affecting the greatest radon concentration reduction.

Assessment of indoor radon gas concentration change of college

International Nuclear Information System (INIS)

Park, Hoon Hee; Jeong, Eui Hwan; Kim, Hak Jae; Lyu, Kang Yeul; Lee, Ju Young

2017-01-01

The purpose of this study was to assess the impact by comparing the concentration of indoor radon and look for ways to lower the concentration of indoor radon gas measurements of three variables, the year of completion, volume of the building and ventilation. Measurement target is six classrooms on the sixth floor of building that was constructed in 1973 and was extended in 2011. Selected classroom's volume is different. Four classrooms were selected to compare the radon concentration in accordance with the year of completion, Classrooms that is same year of completion were selected to compare the radon concentration in accordance with the volume, six classroom was performed closure and ventilation to compare radon concentration according to ventilation. Radon concentrations in accordance with the year of building completion showed a high concentration of radon in a building recently built. Also, Radon concentration in volume is high the smaller the volume. Radon concentration change according to ventilation showed a reduction of about 80% when the ventilation than during closing. Especially, The radon concentrations were high detected while the recently year of building completion and the smaller volume. Ventilation of the three variables is considered that can be expected to exposure reduction effect by radon affecting the greatest radon concentration reduction

False positive acetaminophen concentrations in icteric serum

Directory of Open Access Journals (Sweden)

L. de Jong

2016-04-01

Full Text Available Introduction: Serum concentrations of acetaminophen are measured to predict the risk of hepatotoxicity in cases of acetaminophen overdose and to identify acetaminophen use in patients with acute liver injury without a known cause. The acetaminophen concentration determines if treatment with N-acetyl cysteine, the antidote for acetaminophen poisoning, is warranted. Description: A 49-year-old woman was admitted to our hospital with a hepatic encephalopathy and a total serum bilirubin concentration of 442 µmol/l. The acetaminophen concentration of 11.5 mg/l was measured with an enzymatic-colorimetric assay, thus treatment with N-acetyl cysteine was started. Interestingly, the acetaminophen concentration remained unchanged (11.5–12.3 mg/l during a period of 4 consecutive days. In contrast, the acetaminophen concentration measured by HPLC, a chromatographic technique, remained undetectable Discussion: In the presented case, elevated bilirubin was the most likely candidate to interfere with acetaminophen assay causing false positive results. Bilirubin has intense absorbance in the ultraviolet and visible regions of the electromagnetic spectrum and for that reason it causes interference in an enzymatic-colorimetric assay. Conclusion: False positive acetaminophen laboratory test results may be found in icteric serum, when enzymatic-colorimetric assays are used for determination of an acetaminophen concentration. Questionable acetaminophen results in icteric serum should be confirmed by a non-enzymatic method, by means of ultrafiltration of the serum, or by dilution studies. Keywords: Acetaminophen, Enzymatic-colorimetric assays, HPLC, Bilirubin, Interference, Paracetamol, Liver failure, Jaundice

Arsenic concentrations in Chinese coals

International Nuclear Information System (INIS)

Wang Mingshi; Zheng Baoshan; Wang Binbin; Li Shehong; Wu Daishe; Hu Jun

2006-01-01

The arsenic concentrations in 297 coal samples were collected from the main coal-mines of 26 provinces in China were determined by molybdenum blue coloration method. These samples were collected from coals that vary widely in coal rank and coal-forming periods from the five main coal-bearing regions in China. Arsenic content in Chinese coals range between 0.24 to 71 mg/kg. The mean of the concentration of Arsenic is 6.4 ± 0.5 mg/kg and the geometric mean is 4.0 ± 8.5 mg/kg. The level of arsenic in China is higher in northeastern and southern provinces, but lower in northwestern provinces. The relationship between arsenic content and coal-forming period, coal rank is studied. It was observed that the arsenic contents decreases with coal rank in the order: Tertiary > Early Jurassic > Late Triassic > Late Jurassic > Middle Jurassic > Late Permian > Early Carboniferous > Middle Carboniferous > Late Carboniferous > Early Permian; It was also noted that the arsenic contents decrease in the order: Subbituminous > Anthracite > Bituminous. However, compared with the geological characteristics of coal forming region, coal rank and coal-forming period have little effect on the concentration of arsenic in Chinese coal. The average arsenic concentration of Chinese coal is lower than that of the whole world. The health problems in China derived from in coal (arsenism) are due largely to poor local life-style practices in cooking and home heating with coal rather than to high arsenic contents in the coal

CMAQ predicted concentration files

Data.gov (United States)

U.S. Environmental Protection Agency — model predicted concentrations. This dataset is associated with the following publication: Muñiz-Unamunzaga, M., R. Borge, G. Sarwar, B. Gantt, D. de la Paz, C....

Nutrient concentrations in a Littorella uniflora community at higher CO₂ concentrations and reduced light intensities

DEFF Research Database (Denmark)

Andersen, T.; Pedersen, O.; Andersen, F. Ø.

2005-01-01

laboratory experiments with isoetid vegetation (Littorella uniflora) where water column CO2 and light could be manipulated in order to test whether (i) light and CO2 availability affect nutrient concentrations in isoetid vegetation, and (ii) if changes in light and CO2 climate affect fluxes of inorganic...... nitrogen (N) and phosphorus (P) from sediment to water column, which potentially could result in increased growth of epiphytic algae. 3. The results showed that the standing stocks of phosphorus and nitrogen in the L. uniflora vegetation were significantly influenced by CO2 concentration and light...... intensity. Both standing stocks of P and N were significantly higher in the mesocosm treatments with high CO2 concentration than in those at low CO2 concentration. Similarly, standing stocks of P and N enhanced with increasing light intensity. 4. Measurements of nutrient fluxes both in the field...

Concentration transients in a gaseous diffusion plant (1961); Cinetique des concentrations dans une usine de separation isotopique (1961)

Energy Technology Data Exchange (ETDEWEB)

Jacques, R; Bilous, O [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

Concentration transients are examined in the case of a gaseous diffusion plant for uranium isotope separation. An application is made for a plant built with two rectifying cascades of different sizes and a stripping cascade. Transients are calculated for a change in the feed concentration, the transport and also for shutdown of a group of separating stages in one of the cascades. (authors) [French] On examine l'evolution des concentrations dans une usine de separation isotopique de l'uranium basee sur le procede de diffusion gazeuse et formee de cascades carrees. Une application est faite pour une installation formee de deux cascades enrichissantes de tailles differentes et d'une cascade appauvrissante. On calcule en particulier les regimes transitoires apres variation de la concentration d'alimentation, du transport et apres mise hors circuit d'un groupe d'etages dans l'une des cascades. (auteurs)

Recalculation of measured fuel nuclide concentrations

International Nuclear Information System (INIS)

Moeller, W.

1984-01-01

The concentrations and concentration ratios of heavy fuel nuclides determined in the Central Institute for Nuclear Research Rossendorf on the basis of destructive burnup measurements are compared with the results of microburnup calculations. The possibility is discussed to improve the results by taking into account the spectral characteristics at the positions of the measuring samples. (author)

Agronomic behavior of phosphoric rock from Bahia Inglesa using isotopic techniques. 1. Field trial with concentrated and non concentrated rock

International Nuclear Information System (INIS)

Pino N, I.; Casa G, L.

1989-01-01

With the aim to assess the agronomic behaviour of the phosphoric rock from Bahia Inglesa, a field trial was carried out with concentrated and non concentrated 100 mesh sieved rock. The method of isotopic dilution was used with TSP labeled P32 (TSP-P32) as standard fertilizer. Total dry matter, total P by colorimetry and P32 by liquid scintillation using the Cerenkov effect were measured. Both agronomic and isotope parameters were analyzed. The concentrated phosphoric rock was 3.7 times better than the same non concentrated rock. These also was a positive effect from non concentrated at 400 kg P205/ha dose. This effect was attributed to a higher saturation in the points of P sorption. The TSP showed a better behaviour than the phosphoric rock under study. (author)

2011 NATA - Risks and Annual Ambient Concentrations

Data.gov (United States)

U.S. Environmental Protection Agency — This dataset includes the modeled annual ambient concentrations and risks at the census tract level for the 2011 National Air Toxics Assessment. All concentrations...

Optimum Concentration Ratio Analysis Using Dynamic Thermal Model for Concentrated Photovoltaic System

Science.gov (United States)

2012-03-22

Iberoamericano de Estudiantes de Ingenieria Electrica, s.l. : Cibelec, 2005. 40. Brogren, Maria. Optical Effeciency of Low-Concentrating Solar Energy...46 3.5 Particular Solution to the Transport Equation...50 3.7 Homogenous Solution the Transport Equation ..................................................... 51 3.8 Total Excess

Design of three-dimensional nonimaging concentrators with inhomogeneous media

Science.gov (United States)

Minano, J. C.

1986-09-01

A three-dimensional nonimaging concentrator is an optical system that transforms a given four-parametric manifold of rays reaching a surface (entry aperture) into another four-parametric manifold of rays reaching the receiver. A procedure of design of such concentrators is developed. In general, the concentrators use mirrors and inhomogeneous media (i.e., gradient-index media). The concentrator has the maximum concentration allowed by the theorem of conservation of phase-space volume. This is the first known concentrator with such properties. The Welford-Winston edge-ray principle in three-dimensional geometry is proven under several assumptions. The linear compound parabolic concentrator is derived as a particular case of the procedure of design.

Validation of image cytometry for sperm concentration measurement

DEFF Research Database (Denmark)

Egeberg Palme, Dorte L.; Johannsen, Trine Holm; Petersen, Jørgen Holm

2017-01-01

Sperm concentration is an essential parameter in the diagnostic evaluation of men from infertile couples. It is usually determined by manual counting using a hemocytometer, and is therefore both laborious and subjective. We have earlier shown that a newly developed image cytometry (IC) method may...... be used to determine sperm concentration. Here we present a validation of the IC method by analysis of 4010 semen samples. There was high agreement between IC and manual counting at sperm concentrations above 3 mill/ml and in samples with concentrations above 12 mill/ml the two methods can be used...... a lower coefficient of variation than the manual method (5% vs 10%), indicating a better precision of the IC method. In conclusion, measurement of sperm concentration by IC can be used at concentrations above 3 mill/ml and seems more accurate and precise than manual counting, making it an attractive...

Nicotine concentration of e-cigarettes used by adolescents.

Science.gov (United States)

Morean, Meghan E; Kong, Grace; Cavallo, Dana A; Camenga, Deepa R; Krishnan-Sarin, Suchitra

2016-10-01

E-cigarettes are popular among youth, but little is known about the nicotine concentrations of e-liquids used by adolescents. In Spring, 2014, we conducted cross-sectional surveys in four Connecticut high schools and two middle schools. Among past-30-day e-cigarette users (n=513, 45% female, mean age 15.9 [SD=1.4]), we examined what nicotine concentration adolescents typically used in their e-cigarettes (range 0-30mg/mL and "I don't know"). We first examined whether age, sex, smoking status, e-cigarette use frequency, and/or e-cigarette acquisition source were associated with using nicotine-free e-liquid, nicotine e-liquid, or not knowing the e-liquid nicotine concentration. Among nicotine users (n=185), we then examined whether the aforementioned variables were associated with using higher nicotine concentrations. Adolescents reported using nicotine-free e-liquid (28.5%), nicotine e-liquid (37.4%), or not knowing their e-liquid nicotine concentration (34.1%). Nicotine users comprised more smokers and heavier e-cigarette users compared to nicotine-free e-liquid users and those who did not know their nicotine concentration. Nicotine users also comprised more males and were more likely to purchase e-cigarettes online or from tobacco shops compared to those who did not know their nicotine concentration. Among nicotine users, cigarette smoking, male sex, and purchasing e-cigarettes from tobacco shops predicted using higher nicotine concentrations. Adolescents reported using e-liquids with variable nicotine concentrations. Smokers, males, and those who purchased their own e-cigarettes reported using the highest nicotine levels. Of concern, many adolescents were unaware of the nicotine concentration in their e-liquid, raising concerns about inadvertent nicotine exposure among youth. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Target concentration intervention: beyond Y2K.

Science.gov (United States)

Holford, N H

2001-01-01

Target concentration intervention (TCI) is proposed as an alternative conceptual strategy to therapeutic drug monitoring (TDM). It is argued that the idea of a therapeutic range has limited the interpretation of measured drug concentrations and diminished the anticipated clinical benefit to patients by use of an oversimplified pharmacodynamic model. TCI on the other hand embraces pharmacokinetic and pharmacodynamic concepts and uses the idea of a target effect and associated target concentration to make rational individual dose decisions.

Radionuclides and selected trace elements in marine protein concentrates

Energy Technology Data Exchange (ETDEWEB)

Beasley, T M; Jokela, T A; Eagle, R J

1971-12-01

The concentrations of various trace elements and radionuclides have been measured in marine protein concentrates prepared from surface feeding fishes. As with concentrates prepared from benthic fishes, the /sup 210/Pb-/sup 210/Po pair are the most significant radionuclides present. Concentrations of stable Pb, Co and Ag in certain concentrates are sufficiently high to contribute substantially to estimated current intakes of these elements.

Recovery of uranium mineral concentrate from copper tailings

International Nuclear Information System (INIS)

Chakravarty, S.; Tewari, U.K.; Beri, K.K.

1991-01-01

Based on the studies conducted on the samples of copper tailings from Surda Copper Concentrator plant, wet concentrating table (Diaster Diagonal Deck) was found most suitable for recovering uranium mineral concentrate. Based on this technique, uranium recovery plants were set up at Surda, Rakha and Mosabani. The recoveries obtained from Surda Uranium Recovery Plant and Rakha Uranium Recovery Plant were in the range of 40-50%. But in Mosaboni Uranium Recovery Plant which is treating copper tailings from Mosaboni Copper Concentrator Plant, the biggest concentrator plant processing nearly 2,700 MT/day of copper ore, the recovery by wet concentrating tables was found to be around 22%. Low recovery was mainly due to low concentration of uranium in ore and as well as more percentage of uranium distribution in fines which tables were unable to recover. Studies were done to recover uranium mineral concentrate from the fines with new set of equipment viz. Curved Static Screen/Bartles Mozley Separator/Cross Belt Concentrator. This gave an improvement of 14-16% only. Studies by low acid leaching in chemical process side have shown that an overall recovery of 68% can be achieved. Though the chemical process is best as far as recovery is concerned but there are several constraints. The major constraint is pertaining to environmental and pollution control. Depending on the results of studies to overcome the constraints decision for the process to be adopted will be taken up and executed. The test results and plant performance data have also been included in the paper. (author). 8 figs., 11 tabs., 1 appendix

High concentration agglomerate dynamics at high temperatures.

Science.gov (United States)

Heine, M C; Pratsinis, S E

2006-11-21

The dynamics of agglomerate aerosols are investigated at high solids concentrations that are typical in industrial scale manufacture of fine particles (precursor mole fraction larger than 10 mol %). In particular, formation and growth of fumed silica at such concentrations by chemical reaction, coagulation, and sintering is simulated at nonisothermal conditions and compared to limited experimental data and commercial product specifications. Using recent chemical kinetics for silica formation by SiCl4 hydrolysis and neglecting aerosol polydispersity, the evolution of the diameter of primary particles (specific surface area, SSA), hard- and soft-agglomerates, along with agglomerate effective volume fraction (volume occupied by agglomerate) is investigated. Classic Smoluchowski theory is fundamentally limited for description of soft-agglomerate Brownian coagulation at high solids concentrations. In fact, these high concentrations affect little the primary particle diameter (or SSA) but dominate the soft-agglomerate diameter, structure, and volume fraction, leading to gelation consistent with experimental data. This indicates that restructuring and fragmentation should affect product particle characteristics during high-temperature synthesis of nanostructured particles at high concentrations in aerosol flow reactors.

Lunar occultation of Saturn. IV - Astrometric results from observations of the satellites

Science.gov (United States)

Dunham, D. W.; Elliot, J. L.

1978-01-01

The method of determining local lunar limb slopes, and the consequent time scale needed for diameter studies, from accurate occultation timings at two nearby telescopes is described. Results for photoelectric observations made at Mauna Kea Observatory during the occultation of Saturn's satellites on March 30, 1974, are discussed. Analysis of all observations of occultations of Saturn's satellites during 1974 indicates possible errors in the ephemerides of Saturn and its satellites.

Evidence for contamination of recent Hawaiian lavas from 230Th-238U data

International Nuclear Information System (INIS)

Condomines, M.; Bernat, M.; Allegre, C.J.

1976-01-01

230 Th- 238 U radioactive disequilibrium was studied in the historical lava flows of the Mauna Loa and Kilauea, Hawaii. Large variations of the ( 230 Th/ 232 Th) ratio among lavas of the same volcano that were erupted at a few years' interval are interpreted as due to contamination. The contamination probably occurs by assimilation of zeolitic minerals formed by seawater interaction while the magma resides in a superficial chamber. (Auth.)

Selection of antibiotic resistance at very low antibiotic concentrations.

Science.gov (United States)

Sandegren, Linus

2014-05-01

Human use of antibiotics has driven the selective enrichment of pathogenic bacteria resistant to clinically used drugs. Traditionally, the selection of resistance has been considered to occur mainly at high, therapeutic levels of antibiotics, but we are now beginning to understand better the importance of selection of resistance at low levels of antibiotics. The concentration of an antibiotic varies in different body compartments during treatment, and low concentrations of antibiotics are found in sewage water, soils, and many water environments due to natural production and contamination from human activities. Selection of resistance at non-lethal antibiotic concentrations (below the wild-type minimum inhibitory concentration) occurs due to differences in growth rate at the particular antibiotic concentration between cells with different tolerance levels to the antibiotic. The minimum selective concentration for a particular antibiotic is reached when its reducing effect on growth of the susceptible strain balances the reducing effect (fitness cost) of the resistance determinant in the resistant strain. Recent studies have shown that resistant bacteria can be selected at concentrations several hundred-fold below the lethal concentrations for susceptible cells. Resistant mutants selected at low antibiotic concentrations are generally more fit than those selected at high concentrations but can still be highly resistant. The characteristics of selection at low antibiotic concentrations, the potential clinical problems of this mode of selection, and potential solutions will be discussed.

Relationship between bank ownership concentration on capital ...

African Journals Online (AJOL)

Relationship between bank ownership concentration on capital adequacy, liquidity, ... In this study we explore the effects of ownership concentration on the ... are material factors in explaining banks' behavior and their market performance.

Storage mediums affect metal concentration in woodlice (Isopoda)

International Nuclear Information System (INIS)

Hendrickx, Frederik; Maelfait, J.-P.; Mayer, Ann de; Tack, F.M.G.; Verloo, M.G.

2003-01-01

Pitfall traps containing formaldehyde influence dry weights and consequently metal concentrations in woodlice. - Terrestrial invertebrates are becoming widely established as tools to assess heavy metal pollution at contaminated sites. A practical and time saving method to sample terrestrial invertebrates consist of pitfall traps, often filled with a 4% formaldehyde solution and some detergent. The reliability of metal concentrations based on organisms captured and stored in this solution might however be questioned and we therefore tested the effect of formaldehyde on Zn, Cu, Cd and Pb concentration experimentally in three isopod species. Our results showed that in many cases, significant decreases in Cu concentrations compared to animals stored in a freezer were observed that could be as high as 40%, while Zn, Cd and Pb concentrations increased. A regression analysis of individual dry weight on individual size revealed that formaldehyde decreases the dry weight substantially and in that way causes increased measurements of Zn, Cd and Pb concentrations. We conclude that pitfall traps with formaldehyde should better not be used to collect animals in which concentrations of heavy metals or other toxic substances will be determined

Uranium concentrations in groundwater, northeastern Washington

Science.gov (United States)

Kahle, Sue C.; Welch, Wendy B.; Tecca, Alison E.; Eliason, Devin M.

2018-04-18

A study of uranium in groundwater in northeastern Washington was conducted to make a preliminary assessment of naturally occurring uranium in groundwater relying on existing information and limited reconnaissance sampling. Naturally occurring uranium is associated with granitic and metasedimentary rocks, as well as younger sedimentary deposits, that occur in this region. The occurrence and distribution of uranium in groundwater is poorly understood. U.S. Environmental Protection Agency (EPA) regulates uranium in Group A community water systems at a maximum contaminant level (MCL) of 30 μg/L in order to reduce uranium exposure, protect from toxic kidney effects of uranium, and reduce the risk of cancer. However, most existing private wells in the study area, generally for single family use, have not been sampled for uranium. This document presents available uranium concentration data from throughout a multi-county region, identifies data gaps, and suggests further study aimed at understanding the occurrence of uranium in groundwater.The study encompasses about 13,000 square miles (mi2) in the northeastern part of Washington with a 2010 population of about 563,000. Other than the City of Spokane, most of the study area is rural with small towns interspersed throughout the region. The study area also includes three Indian Reservations with small towns and scattered population. The area has a history of uranium exploration and mining, with two inactive uranium mines on the Spokane Indian Reservation and one smaller inactive mine on the outskirts of Spokane. Historical (1977–2016) uranium in groundwater concentration data were used to describe and illustrate the general occurrence and distribution of uranium in groundwater, as well as to identify data deficiencies. Uranium concentrations were detected at greater than 1 microgram per liter (μg/L) in 60 percent of the 2,382 historical samples (from wells and springs). Uranium concentrations ranged from less than 1 to

Planar waveguide concentrator used with a seasonal tracker.

Science.gov (United States)

Bouchard, Sébastien; Thibault, Simon

2012-10-01

Solar concentrators offer good promise for reducing the cost of solar power. Planar waveguides equipped with a microlens slab have already been proposed as an excellent approach to produce medium to high concentration levels. Instead, we suggest the use of a cylindrical microlens array to get useful concentration without tracking during the day. To use only a seasonal tracking system and get the highest possible concentration, cylindrical microlenses are placed in the east-west orientation. Our new design has an acceptance angle in the north-south direction of ±9° and ±54° in the east-west axis. Simulation of our optimized system achieves a 4.6× average concentration level from 8:30 to 16:30 with a maximum of 8.1× and 80% optical efficiency. The low-cost advantage of waveguide-based solar concentrators could support their use in roof-mounted solar panels and eliminate the need for an expensive and heavy active tracker.

Metrology of radon and thoron concentrations

International Nuclear Information System (INIS)

Durcik, M; Vicanova, M.

1998-01-01

The alpha spectrometry measurements of radon (radon-222) and thoron (radon-220) concentrations by ionisation chamber, used only in laboratory conditions are described in this paper. For the measurements of radon and thoron in dwellings and work areas was proposed diffusion double chamber detector with track detector. The described dosimeter is very useful for routine measurement and would be applied in measuring of radon and thoron concentrations in caves and dwellings. Big disadvantage of the dosimeter is small holes in cover and it could not be used in dusty areas. From previous measurements of the equilibrium equivalent thoron concentrations by semiconductor detector the measured values ranged from 0.1 to 5.6 Bq m -3 in the Slovak kindergartens were obtained

Mechanisms of urine concentration and dilution (1961); Les mecanismes de concentration et de dilution de l'urine (1961)

Energy Technology Data Exchange (ETDEWEB)

Morel, F; Guinnebault, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

This paper is devoted to the analysis of a problem in the field of renal physiology which has shown many new developments during the course of the last few years. The following are treated successively: a) the data obtained from measurements of free water clearance and their interpretation; b) the data provided by nephron morphology and the comparative anatomy of the kidney ; c) the data relative to the existence of an intrarenal osmotic gradient; d) the principle of concentration multiplication by a counter current technique; e) the present day theory of counter current concentration of urine, and f) the physiological check on dilution and concentration mechanisms in urine. Lastly, the advantages of the modern theory and the unknown factors which remain are discussed. (authors) [French] Cette revue de question est consacree l'analyse d'un probleme de physiologie renale qui, au cours des dernieres annees, a subi un developpement et un renouveau remarquables. Sont successivement exposes: a) les donnees fournies par les mesures de clearance de l'eau libre et leur interpretation; b) les donnees fournies par la morphologie des nephrons et l'anatomie comparee du rein; c) les donnees concernant l'existence d'un gradient osmotique intrarenal; d) le principe de multiplication de concentration par contrecourant; e) la theorie actuelle de concentration de l'urine par contre-courant, et f) le controle physiologique des mecanismes de dilution et de concentration de l'urine. Les avantages de la theorie moderne et les obscurites qui subsistent sont enfin discutes. (auteurs)

Concentration of stable elements in food products

International Nuclear Information System (INIS)

Montford, M.A.; Shank, K.E.; Hendricks, C.; Oakes, T.W.

1980-01-01

Food samples were taken from commercial markets and analyzed for stable element content. The concentrations of most stable elements (Ag, Al, As, Au, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Cu, Fe, Hf, I, K, La, Mg, Mn, Mo, Na, Rb, Sb, Sc, Se, Sr, Ta, Th, Ti, V, Zn, Zr) were determined using multiple-element neutron activation analysis, while the concentrations of other elements (Cd, Hg, Ni, Pb) were determined using atomic absorption. The relevance of the concentrations found are noted in relation to other literature values. An earlier study was extended to include the determination of the concentration of stable elements in home-grown products in the vicinity of the Oak Ridge National Laboratory. Comparisons between the commercial and local food-stuff values are discussed

Nitrate concentrations in drainage water in marine clay areas : exploratory research of the causes of increased nitrate concentrations

NARCIS (Netherlands)

Boekel, van E.M.P.M.; Roelsma, J.; Massop, H.T.L.; Hendriks, R.F.A.; Goedhart, P.W.; Jansen, P.C.

2013-01-01

The nitrate concentrations measured in drainage water and groundwater at LMM farms (farms participating in the National Manure Policy Effects Measurement Network (LLM)) in marine clay areas have decreased with 50% since the mid-nineties. The nitrate concentrations in marine clay areas are on average

Extremely high concentration of folates in premature newborns.

Science.gov (United States)

Zikavska, T; Brucknerova, I

2014-01-01

Extremely high concentration of folates in premature newborns: case reports. Folates are a group of water soluble compounds, which are important for metabolic processes in human body. These are important during periods of rapid cell growth. The most accurate indicator of long-term folate level status in the body is the determination of red blood cell (RBC) folate concentrations. The optimal level of RBC folate is not known in neonatal period. Authors discuss the reasons for extremely high level of RBC folate concentrations. In our work we present the cases of two premature newborns with extremely high level of RBC folate concentrations, which were analyzed immunochemically on the first day of life and after six weeks of life. In both cases we measured RBC folate concentrations on the 1st day of life. After 6 weeks we found extremely high RBC folate concentration level (5516.67 ng/ml) in the first case after RBC transfusions. In second case after two months of life the RBC folate concentration level was doubled (2335.1 ng/ml) until 24 hours after RBC transfusion compared to levels after birth. The normal range of RBC folate values vary in newborns. The upper limit of daily dose of folic acid in pregnancy and neonatal period is not known. On the other hand it is an easily excreted water-soluble vitamin but in premature newborn it can lead to the disruption of metabolic balance and slow its degradation. Some factors can have an impact on RBC folate concentration. Blood transfusion can be one of the main influences on RBC folate concentration. To clarify these mechanisms further studies are required (Ref. 29).

Normal lactate concentration range in the neonatal brain.

Science.gov (United States)

Tomiyasu, Moyoko; Aida, Noriko; Shibasaki, Jun; Tachibana, Yasuhiko; Endo, Mamiko; Nozawa, Kumiko; Shimizu, Eiji; Tsuji, Hiroshi; Obata, Takayuki

2016-11-01

Lactate peaks are occasionally observed during in vivo magnetic resonance spectroscopy (MRS) scans of the neonatal brain, even in healthy patients. The purpose of this study was to investigate the normal range of neonatal brain lactate concentration, as a definitive normal range would be clinically valuable. Using a clinical 3T scanner (echo/repetition times, 30/5000ms), single-voxel MRS data were obtained from the basal ganglia (BG) and centrum semiovale (CS) in 48 healthy neonates (postconceptional age (PCA), 30-43weeks), nine infants (age, 1-12months old), and 20 children (age, 4-15years). Lactate concentrations were calculated using an MRS signal quantification program, LCModel. Correlations between regional lactate concentration and PCA (neonates), or age (all subjects) were investigated. Absolute lactate concentrations of the BG and CS were as follows: neonates, 0.77mM (0-2.02) [median (range)] and 0.77 (0-1.42), respectively; infants, 0.38 (0-0.79) and 0.49 (0.17-1.17); and children, 0.17 (0-0.76) and 0.22 (0-0.80). Overall, subjects' lactate concentrations decreased significantly with age (Spearman: BG, n=61, ρ=-0.38, p=0.003; CS, n=68, ρ=-0.57, p<0.001). However, during the neonatal period no correlations were detected between lactate concentration in either region and PCA. We determined normal ranges of neonatal lactate concentration, which may prove useful for diagnostic purposes. Further studies regarding changes in brain lactate concentration during development would help clarify the reasons for higher concentrations observed during the neonatal period, and contribute to improvements in diagnoses. Copyright © 2016 Elsevier Inc. All rights reserved.

Applications of maximally concentrating optics for solar energy collection

Science.gov (United States)

O'Gallagher, J.; Winston, R.

1985-11-01

A new family of optical concentrators based on a general nonimaging design principle for maximizing the geometric concentration, C, for radiation within a given acceptance half angle ±θα has been developed. The maximum limit exceeds by factors of 2 to 10 that attainable by systems using focusing optics. The wide acceptance angles permitted using these techniques have several unique advantages for solar concentrators including the elimination of the diurnal tracking requirement at intermediate concentrations (up to ˜10x), collection of circumsolar and some diffuse radiation, and relaxed tolerances. Because of these advantages, these types of concentrators have applications in solar energy wherever concentration is desired, e.g. for a wide variety of both thermal and photovoltaic uses. The basic principles of nonimaging optical design are reviewed. Selected configurations for thermal collector applications are discussed and the use of nonimaging elements as secondary concentrators is illustrated in the context of higher concentration applications.

Concentration of solar radiation by white painted transparent plates.

Science.gov (United States)

Smestad, G; Hamill, P

1982-04-01

A simple flat-plate solar concentrator is described in this paper. The device is composed of a white painted transparent plate with a photovoltaic cell fixed to an unpainted area on the bottom of the plate. Light scattering off the white material is either lost or directed to the solar cell. Experimental concentrations of up to 1.9 times the incident solar flux have been achieved using white clays. These values are close to those predicted by theory for the experimental parameters investigated. A theory of the device operation is developed. Using this theory suggestions are made for optimizing the concentrator system. For reasonable choices of cell and plate size and reflectivities of 80% concentrations of over 2x are possible. The concentrator has the advantage over other systems in that the concentration is independent of incidence angle and the concentrator is easy to produce. The device needs no tracking system and will concentrate on a cloudy day.

Concentration of technetium by marine organisms

International Nuclear Information System (INIS)

Koyanagi, T.; Suzuki, Y.; Nakamura, R.; Nakahara, M.

1990-01-01

Accumulation and excretion of technetium by marine organisms were observed in radioisotope tracer experiments to determine concentration factors for estimating radiation dose to humans from radioactive pollution of marine environments. Marine fish, crustaceans, mollusks, echinoderms, and seaweeds were reared in sea water labeled with 95m Tc to observe uptake from sea water. The organisms were then transferred into unlabeled sea water for depuration experiments. Concentration factors were calculated from uptake and excretion rates. Also considered was the contribution of food-chain transfer of technetium, observed by administering labeled seaweeds to mollusks or echinoderms. Low accumulations were shown by fish, crustaceans, pelecypods and cephalopods, whereas high concentration factors were observed in gastropods and seaweeds. Species specificity or specific accumulation in special organs or tissues was not evident except in seaweed, where the difference was clearly species-associated. Relatively high rates of technetium retention were observed in the organisms administered labeled seaweed. The higher concentrations observed in gastropods, compared to those in pelecypods, were thought to result from different feed habits. The adaptability of some species as indicator organisms for monitoring 99 Tc in sea water was recognized, but the contribution of technetium to radiation dose was considered insignificant

Concentration profiles near an activated enzyme.

Science.gov (United States)

Park, Soohyung; Agmon, Noam

2008-09-25

When a resting enzyme is activated, substrate concentration profile evolves in its vicinity, ultimately tending to steady state. We use modern theories for many-body effects on diffusion-influenced reactions to derive approximate analytical expressions for the steady-state profile and the Laplace transform of the transient concentration profiles. These show excellent agreement with accurate many-particle Brownian-dynamics simulations for the Michaelis-Menten kinetics. The steady-state profile has a hyperbolic dependence on the distance of the substrate from the enzyme, albeit with a prefactor containing the complexity of the many-body effects. These are most conspicuous for the substrate concentration at the surface of the enzyme. It shows an interesting transition as a function of the enzyme turnover rate. When it is high, the contact concentration decays monotonically to steady state. However, for slow turnover it is nonmonotonic, showing a minimum due to reversible substrate binding, then a maximum due to diffusion of new substrate toward the enzyme, and finally decay to steady state. Under certain conditions one can obtain a good estimate for the critical value of the turnover rate constant at the transition.

27 CFR 25.296 - Record of beer concentrate.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Record of beer concentrate..., DEPARTMENT OF THE TREASURY LIQUORS BEER Records and Reports § 25.296 Record of beer concentrate. (a) Daily records. A brewer who produces concentrate or reconstitutes beer shall maintain daily records which...

Sucralfate significantly reduces ciprofloxacin concentrations in serum.

OpenAIRE

Garrelts, J C; Godley, P J; Peterie, J D; Gerlach, E H; Yakshe, C C

1990-01-01

The effect of sucralfate on the bioavailability of ciprofloxacin was evaluated in eight healthy subjects utilizing a randomized, crossover design. The area under the concentration-time curve from 0 to 12 h was reduced from 8.8 to 1.1 micrograms.h/ml by sucralfate (P less than 0.005). Similarly, the maximum concentration of ciprofloxacin in serum was reduced from 2.0 to 0.2 micrograms/ml (P less than 0.005). We conclude that concurrent ingestion of sucralfate significantly reduces the concentr...

Concentric Split Flow Filter

Science.gov (United States)

Stapleton, Thomas J. (Inventor)

2015-01-01

A concentric split flow filter may be configured to remove odor and/or bacteria from pumped air used to collect urine and fecal waste products. For instance, filter may be designed to effectively fill the volume that was previously considered wasted surrounding the transport tube of a waste management system. The concentric split flow filter may be configured to split the air flow, with substantially half of the air flow to be treated traveling through a first bed of filter media and substantially the other half of the air flow to be treated traveling through the second bed of filter media. This split flow design reduces the air velocity by 50%. In this way, the pressure drop of filter may be reduced by as much as a factor of 4 as compare to the conventional design.

Entropy concentration and the empirical coding game

NARCIS (Netherlands)

Grünwald, P.D.

2008-01-01

We give a characterization of maximum entropy/minimum relative entropy inference by providing two 'strong entropy concentration' theorems. These theorems unify and generalize Jaynes''concentration phenomenon' and Van Campenhout and Cover's 'conditional limit theorem'. The theorems characterize

Optimal Aquifer Pumping Policy to Reduce Contaminant Concentration

Directory of Open Access Journals (Sweden)

Ali Abaei

2012-01-01

Full Text Available Different sources of ground water contamination lead to non-uniform distribution of contaminant concentration in the aquifer. If elimination or containment of pollution sources was not possible, the distribution of contaminant concentrations could be modified in order to eliminate peak concentrations using optimal water pumping discharge plan. In the present investigation Visual MODFLOW model was used to simulate the flow and transport in a hypothetic aquifer. Genetic Algorithm (GA also was applied to optimize the location and pumping flow rate of wells in order to reduce contaminants peak concentrations in aquifer.

Platelet Concentrates: Past, Present and Future

OpenAIRE

Prakash, Shobha; Thakur, Aditi

2011-01-01

Platelets play a crucial role in hemostasis and wound healing, platelet growth factors are well known source of healing cytokines. Numerous techniques of autologous platelet concentrates have been developed and applied in oral and maxillofacial surgery. This review describes the evolution of the first and second generation of platelet concentrates (platelet rich plasma and platelet rich fibrin respectively) from their fore runner-fibrin sealants.

Radon concentration in dwellings in Aomori Prefecture, Japan

International Nuclear Information System (INIS)

Iyogi, T.; Ueda, S.; Hisamatsu, S.; Kondo, K.; Nakamura, Y.; Tsuji, N.; Mitsubishi Heavy Industries Ltd., Kobe

2002-01-01

To obtain an average dose from 222 Rn to the people in Aomori Prefecture where the first Japan's nuclear fuel cycling facilities are now under construction, we surveyed 222 Rn concentrations in 109 dwellings in the Prefecture from 1992 to 1996. The outdoor 222 Rn concentrations were also measured in gardens of 15 dwellings. The 222 Rn concentrations were measured with passive 222 Rn detectors which used a polycarbonate film for counting α-ray and could separate concentrations of 222 Rn from 220 Rn. Counting efficiencies of the detectors were calibrated with a standard 222 Rn chamber in the Environmental Measurement Laboratory in USA and in the National Radiological Protection Board in UK. Geometric means of 222 Rn concentration were 13 and 4.4 Bq x m -3 in the dwellings and outdoor, respectively. These values were consistent to nationwide survey results in Japan. The 222 Rn concentrations in the dwellings depended on their age. The concentrations were higher in recent dwellings than in older ones. The radiation dose from 222 Rn was estimated, taking into account the occupancy factor for inside and outside of dwellings. The annual dose was 0.32 mSv x y -1 , and 99% of the dose came from the exposure to 222 Rn inside the dwelling. (author)

Effects Of Exposure To Sublethal Concentrations Of Azadirachta ...

African Journals Online (AJOL)

The physiological impairment on the fingerlings of Clarias gariepinus when exposed to sublethal concentrations of Azadirachta Indica was investigated. The fish were exposed to concentrations of 1.25, 2.50, 5.0, 10.0, 20.0 ML -1 for the period of 12 weeks. The crude protein content decreased with increased concentration ...

Effect of concentrations of Artemia salina on zootechnical ...

African Journals Online (AJOL)

The best performances of survival, growth and metamorphosis were produced by 3 AN/ml concentrations of Artemia. The cost of food has increased with the concentration level of Artemia. Then, the production of viable shrimp post larvae and cheaper may be done at 3 AN/ml optimal concentrations of Artemia. Keywords: ...

Magnetic concentration of iron-titanium ore with vanadium concentrate from campo Alegre de Lourdes - Bahia, Brazil

International Nuclear Information System (INIS)

Delgado, O.; Silva, F.T. da; Ogasawara, T.; Soares, G.F.

1988-01-01

The feasibility studies of magnetic concentration of the Campo Alegre de Lourdes ore were carried out, trying to obtain a maximum recovery of vanadium. As a consequence of the complex nature of the ore, mainly due to the presence of ilmenite as a exolutions in the interior of hematite/martite particles, it was not possible to separate the hematite-ilmenite eficiently, wich would be necessary for obtaining a high grade vanadium concentrate with low titanium content. (author) [pt

Assessment of Concentration in the Economy of Ukraine

Directory of Open Access Journals (Sweden)

Khaustova Viktoriia Ye.

2017-09-01

Full Text Available The article is dedicated to the generalization of theoretical aspects of economic concentration and assessment of concentration in Ukraine’s economy. It is proved that in the world there is a stable trend towards the spread of concentration processes both at the level of economies in general and individual industries and business entities, and it occurs predominantly within TNCs. The main stages of the development of TNCs are considered, and it is shown that modern TNCs are large corporations that are the main players in the market. The genesis of the theory of concentration in economy is considered. The views of scientists on the interpretation of the concept “concentration” are studied. It is proved that it is used in different meanings and with respect to different levels of economy and objects of consideration, and there is a wide diversity of basic criteria that determine the essential signs of this concept. The interpretation of the concept “concentration of the country’s economy” is proposed. The existing approaches to assessment of concentration in economy are analyzed. The trends in the development of concentration processes in Ukraine’s economy and the factors that are determined by them are analyzed. There investigated the distribution of industries of Ukraine’s economy in terms of net income of the largest corporations, dynamics of net income of the largest corporations, dynamics of distribution of industries of Ukraine’s economy in terms of profits of large companies, dynamics of net profit of the largest corporations of the top 10 industries of Ukraine’s economy, dynamics of the GDP of Ukraine and main indicators of the largest national corporations. The concentration of Ukraine’s economy is assessed, and it is determined that the most highly concentrated spheres are production of electronics and computers, the automotive industry, media, production of personal goods and software, provision of business

Isoflurane minimum alveolar concentration reduction by fentanyl.

Science.gov (United States)

McEwan, A I; Smith, C; Dyar, O; Goodman, D; Smith, L R; Glass, P S

1993-05-01

Isoflurane is commonly combined with fentanyl during anesthesia. Because of hysteresis between plasma and effect site, bolus administration of fentanyl does not accurately describe the interaction between these drugs. The purpose of this study was to determine the MAC reduction of isoflurane by fentanyl when both drugs had reached steady biophase concentrations. Seventy-seven patients were randomly allocated to receive either no fentanyl or fentanyl at several predetermined plasma concentrations. Fentanyl was administered using a computer-assisted continuous infusion device. Patients were also randomly allocated to receive a predetermined steady state end-tidal concentration of isoflurane. Blood samples for fentanyl concentration were taken at 10 min after initiation of the infusion and before and immediately after skin incision. A minimum of 20 min was allowed between the start of the fentanyl infusion and skin incision. The reduction in the MAC of isoflurane by the measured fentanyl concentration was calculated using a maximum likelihood solution to a logistic regression model. There was an initial steep reduction in the MAC of isoflurane by fentanyl, with 3 ng/ml resulting in a 63% MAC reduction. A ceiling effect was observed with 10 ng/ml providing only a further 19% reduction in MAC. A 50% decrease in MAC was produced by a fentanyl concentration of 1.67 ng/ml. Defining the MAC reduction of isoflurane by all the opioids allows their more rational administration with inhalational anesthetics and provides a comparison of their relative anesthetic potencies.

Hybrid Perovskites: Prospects for Concentrator Solar Cells.

Science.gov (United States)

Lin, Qianqian; Wang, Zhiping; Snaith, Henry J; Johnston, Michael B; Herz, Laura M

2018-04-01

Perovskite solar cells have shown a meteoric rise of power conversion efficiency and a steady pace of improvements in their stability of operation. Such rapid progress has triggered research into approaches that can boost efficiencies beyond the Shockley-Queisser limit stipulated for a single-junction cell under normal solar illumination conditions. The tandem solar cell architecture is one concept here that has recently been successfully implemented. However, the approach of solar concentration has not been sufficiently explored so far for perovskite photovoltaics, despite its frequent use in the area of inorganic semiconductor solar cells. Here, the prospects of hybrid perovskites are assessed for use in concentrator solar cells. Solar cell performance parameters are theoretically predicted as a function of solar concentration levels, based on representative assumptions of charge-carrier recombination and extraction rates in the device. It is demonstrated that perovskite solar cells can fundamentally exhibit appreciably higher energy-conversion efficiencies under solar concentration, where they are able to exceed the Shockley-Queisser limit and exhibit strongly elevated open-circuit voltages. It is therefore concluded that sufficient material and device stability under increased illumination levels will be the only significant challenge to perovskite concentrator solar cell applications.

Nonimaging concentrators for photovoltaic arrays in space

Science.gov (United States)

Winston, R.; Greenman, P.; Rockey, D.

1981-01-01

Two stage concentrators are studied in order to design an optimum concentrator for photovoltaic arrays in space. The study is directed at designs with two-dimensional geometries because they are better suited to moderate concentrations of about 10 X to 50 X, and because the instantaneous flux distribution is more uniform. It is found that with an f/0.5 primary, where f is the focal length of the primary, the flux distribution is very smooth regardless of the angle of incidence of the radiation. As the focal ratio is increased, peaks in the distribution begin to appear. The nonuniformities can be reduced by introducing small, closely spaced distortions into the reflecting surfaces, and practical arrays can achieve a concentration of 10 when the acceptance half angle is 4.25 deg or 50 when the acceptance half angle is + or - 1 deg.

Stress concentration effects in high pressure components

International Nuclear Information System (INIS)

Aller, J.E.

1990-01-01

This paper examines the stress concentration effects of sideholes in thick walled, high pressure cylinders. It has been shown that the theoretical stress concentration factor at the intersection of a small crossbore in a closed end, thick walled cylinder varies between 3.0 and 4.0. Tests have shown that this effect can be greatly reduced in practice by carefully radiusing the bore intersection and autofrettaging the cylinder. It has also been shown that the minimum stress concentration factor occurs when the main bore and sidehole or crossbore have the same diameter, and the radius of the intersection is approximately equal to the sidehole radius. When the bore and sidehole intersection angle decreases from 90 degrees, the stress concentration factor increases significantly. Knowledge of these fundamental relationships can be used in maintaining, as well ad designing, high pressure equipment

Multijunction Photovoltaic Technologies for High-Performance Concentrators: Preprint

Energy Technology Data Exchange (ETDEWEB)

McConnell, R.; Symko-Davies, M.

2006-05-01

Multijunction solar cells provide high-performance technology pathways leading to potentially low-cost electricity generated from concentrated sunlight. The National Center for Photovoltaics at the National Renewable Energy Laboratory has funded different III-V multijunction solar cell technologies and various solar concentration approaches. Within this group of projects, III-V solar cell efficiencies of 41% are close at hand and will likely be reported in these conference proceedings. Companies with well-developed solar concentrator structures foresee installed system costs of $3/watt--half of today's costs--within the next 2 to 5 years as these high-efficiency photovoltaic technologies are incorporated into their concentrator photovoltaic systems. These technology improvements are timely as new large-scale multi-megawatt markets, appropriate for high performance PV concentrators, open around the world.

Concentration of radiocesium in cultivated mushrooms and substrates

International Nuclear Information System (INIS)

Miyake, Sadaaki; Higasa, Mamoru; Urabe, Ken-ichi; Haraguchi, Masato; Omura, Toshitaka

2008-01-01

Concentrations of 134 Cs, 137 Cs and 40 K in mushrooms cultivated in Saitama prefecture and those substrates were measured by gamma-ray spectrometry. In all mushrooms and substrates, 134 Cs was not detected. Concentrations of 137 Cs in mushrooms were in the range of 0.012 - 2.1 Bq/kg·fresh, and those in substrates were in the range of 0.080 - 1.8 Bq/kg·dry. Concentrations of 137 Cs in mushrooms varied widely with mushroom species, and the average concentration of 137 Cs in Lentinus edodes (Shiitake) was over 30 times higher than that in Pleurotus ostreatus (Hiratake). Mushroom-to-substrate concentration ratios of 137 Cs (fresh/dry) were 0.11-0.53. They were higher than the reported transfer factors for common agricultural plants. (author)

Cervical Collagen Concentration within Fifteen Months after Delivery

DEFF Research Database (Denmark)

Sundtoft, Iben; Uldbjerg, Niels; Sommer, Steffe

2011-01-01

OBJECTIVE: Cervical collagen concentration decreases during pregnancy. The increased risk of preterm birth following a short interpregnancy interval may be explained by an incomplete remodeling of the cervix. The objective of this study was to describe the changes in cervical collagen concentration...... over 15 months following delivery. METHODS: The collagen concentrations were determined in cervical biopsies obtained from 15 women at 3, 6, 9, 12, and 15 months after delivery. RESULTS: The mean cervical collagen concentrations were 50, 59, 63, 65, and 65 % of dry weight (SD 4.2 – 6.5). This increase...... was statistically significant until month 9, but not between months 9 and 12. CONCLUSIONS: Low collagen concentrations in the uterine cervix may contribute to the association between a short interpregnancy interval and preterm birth....

Energy concentration on S-300 pulsed power generator

Energy Technology Data Exchange (ETDEWEB)

Bakshaev, Yu Z; Chernenko, A S; Korolev, V D; Mizhiritskij, V I; Zazhivikhin, V V [Kurchatov Institute, Moscow (Russian Federation)

1997-12-31

Energy concentration in fast Z-pinch investigation experiments on an 8-module 10 TW pulsed power S-300 generator (1.3 MV, 45 ns FWHM, 0.15 Ohm) is realized by a 3-d vacuum energy concentrator. The concentrator was constructed on the basis of triplate MITLs connected in parallel at the central unit where the Z-pinch is formed. At some start-up experiments on the 8-module installation version at 700 kV incident wave amplitude on concentrator for a gas puff load current of 4 MA with rise time of about 60 ns was obtained. The efficiency or current transfer from the concentrator input to the load for both a gas liner and a short-circuited case was practically the same. (author). 4 figs., 4 refs.

Progress In Fresnel-Köhler Concentrators

Science.gov (United States)

Mohedano, Rubén; Cvetković, Aleksandra; Benítez, Pablo; Chaves, Julio; Miñano, Juan C.; Zamora, Pablo; Hernandez, Maikel; Vilaplana, Juan

2011-12-01

The Fresnel Köhler (FK) concentrator was first presented in 2008. Since then, various CPV companies have adopted this technology as base for their future commercial product. The key for this rapid penetration is a mixture of simplicity (the FK is essentially a Fresnel lens concentrator, a technology that dominates the market) and excellent performance: high concentration without giving up large manufacturing/aiming tolerances, enabling high efficiency even at the array level. All these features together have a great potential to lower energy costs. This work shows recent results and progress regarding this device, covering new design features, measurements and tests along with first performance achievements at the array level (pilot 6.5 Kwp plant). The work also discusses the potential impact of the FK enhanced performance on the Levelized Cost Of Electricity (LCOE).

Thermogravimetric study of rare earth concentrates

International Nuclear Information System (INIS)

Delyagejd, V.V.; Anisimova, V.N.; Eremenko, Z.V.; Kutsev, V.S.

1974-01-01

Methods of thermogravimetric, chemical and phase analysis were used in measuring the concentration of rare-earth elements of different origins. At temperatures 400-800 deg C a gradual decomposition of fluorocarbonates takes place leading to the formation of derivatives of corresponding oxides and oxyfluorides. For concentrates containing siderite the process takes place at 550-600 deg C followed by oxidation of bivalent iron into trivalent state. Reaction of rare-earth elements with sodium carbonate and the increase in the concentration of the latter results in a narrowing down of the interval of temperatures at which decomposition takes place. Under these conditions an intense reaction and a fusion take place leading to the formation of eutectic at 500-600 deg C and further synthesis of sodium fluoride and oxyfluoride derivatives of calcium and rare-earth elements

Simulation of concentration distribution of urban particles under wind

Science.gov (United States)

Chen, Yanghou; Yang, Hangsheng

2018-02-01

The concentration of particulate matter in the air is too high, which seriously affects people’s health. The concentration of particles in densely populated towns is also high. Understanding the distribution of particles in the air helps to remove them passively. The concentration distribution of particles in urban streets is simulated by using the FLUENT software. The simulation analysis based on Discrete Phase Modelling (DPM) of FLUENT. Simulation results show that the distribution of the particles is caused by different layout of buildings. And it is pointed out that in the windward area of the building and the leeward sides of the high-rise building are the areas with high concentration of particles. Understanding the concentration of particles in different areas is also helpful for people to avoid and reduce the concentration of particles in high concentration areas.

Indoor radon concentration forecasting in South Tyrol

International Nuclear Information System (INIS)

Verdi, L.; Weber, A.; Stoppa, G.

2004-01-01

In this paper a modern statistical technique of multivariate analysis is applied to an indoor radon concentration database. Several parameters are more or less significant in determining the radon concentration inside a building. The elaboration of the information available on South Tyrol makes it possible both to identify the statistically significant variables and to build up a statistical model that allows us to forecast the radon concentration in dwellings, when the values of the same variables involved are given. The results confirm the complexity of the phenomenon. (authors)

Determination of particle concentrations in multitemperature plasmas

International Nuclear Information System (INIS)

Richley, E.; Tuma, D.T.

1982-01-01

The use of the multitemperature Saha equation (MSE) of Prigogine 1 and Patapov 2 for calculating particle concentrations in plasmas is shown to be an invalid procedure. Errors greater than one order of magnitude in the electron density in high-pressure argon and nitrogen electric arc plasmas can be easily incurred by using the multitemperature Saha equation. The alternative kinetic method for calculating concentrations is shown to be based on firm concepts. Simpliying procedures and computational techniques for calculating concentrations with the kinetic method are illustrated with examples

Plasma fibronectin concentrations in morbidly obese patients

DEFF Research Database (Denmark)

Dejgaard, A; Andersen, T; Christoffersen, Pernille Yde

1984-01-01

Plasma fibronectin concentrations and liver morphology were investigated in 45 morbidly obese subjects (median overweight 88%) and in 42 normal weight controls, matched for sex and age. A significantly (P less than 0.01) raised plasma fibronectin concentration (median 464 mg/l, range 276-862 mg...... in their liver biopsies (r = 0.33, P less than 0.05). Significantly (P less than 0.05) elevated plasma fibronectin concentrations even in obese subjects without hepatic fatty change indicate that liver fat accumulation is no prerequisite of the obesity-related elevation of plasma fibronectin. Raised plasma...

Paracetamol (acetaminophen) protein adduct concentrations during therapeutic dosing.

Science.gov (United States)

Heard, Kennon; Green, Jody L; Anderson, Victoria; Bucher-Bartelson, Becki; Dart, Richard C

2016-03-01

Paracetamol protein adducts (PPA) are a biomarker of paracetamol exposure. PPA are quantified as paracetamol-cysteine (APAP-CYS), and concentrations above 1.1 μmol l(-1) have been suggested as a marker of paracetamol-induced hepatotoxicity. However, there is little information on the range of concentrations observed during prolonged therapeutic dosing. The aim of the present study was to describe the concentration of PPA in the serum of subjects taking therapeutic doses of paracetamol for at least 16 days. Preplanned secondary aim of a prospective randomized controlled (placebo vs. 4g day(-1) paracetamol) trial. We measured subjects' serum PPA concentrations every 3 days for a minimum of 16 days. We also measured concentrations on study days 1-3 and 16-25 in subsets of patients. PPA were quantified as APAP-CYS after gel filtration and protein digestion using liquid chromatography/mass spectrometry. Ninety per cent of subjects had detectable PPA after five doses. Median APAP-CYS concentrations in paracetamol-treated subjects increased to a plateau of 0.1 μmol l(-1) on day 7, where they remained. The highest concentration measured was 1.1 μmol l(-1) and two subjects never had detectable PPA levels. PPA were detected in the serum of 78% of subjects 9 days after their final dose. PPA are detectable in the vast majority of subjects taking therapeutic doses of paracetamol. While most have concentrations well below the threshold associated with hepatotoxicity, concentrations may approach 1.1 μmol l(-1) in rare cases. Adducts are detectable after a few doses and can persist for over a week after dosing is stopped. © 2015 The British Pharmacological Society.

Roadside and in-vehicle concentrations of monoaromatic hydrocarbons

Science.gov (United States)

Leung, Pei-Ling; Harrison, Roy M.

Airborne concentrations of benzene, toluene and the xylenes have been measured inside passenger cars whilst driven along major roads in the city of Birmingham, UK, as well as immediately outside the car, and at the roadside. A comparison of concentrations measured in the car with those determined from immediately outside showed little difference, with a mean ratio for benzene of 1.17±0.34 and for toluene 1.11±0.16 ( n=53). The ratio of in-car to roadside concentration was rather higher at 1.55±0.68 for benzene and 1.54±0.72 for toluene ( n=53). The roadside concentrations were typically several-fold higher than those measured at a background suburban monitoring station within Birmingham, although much variation was seen between congested and uncongested roads, with concentrations adjacent to uncongested roads similar to those measured at the background monitoring station. Measurements of benzene and toluene in a car driven on a rural road outside the city showed very comparable in-car and out-of-car concentrations strengthening the conclusion that pollution inside the car is derived from pollutants outside entering with ventilation air. The exceptions were an older car where in-car concentrations appreciably exceeded those outside (in-to out-vehicle ratio=2.3 for benzene and 2.2 for toluene where n=5) indicating probable self-contamination, and a very new car which built up increased VOC concentrations when stationary without ventilation (in-to out-vehicle ratio=2.4 for benzene and 3.3 for toluene where n=5). A further set of measurements inside London taxi cabs showed concentrations to be influenced by the area within which the taxi was driven, the traffic density and the presence of passengers smoking cigarettes.

21 CFR 146.146 - Frozen concentrated orange juice.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Frozen concentrated orange juice. 146.146 Section... Fruit Juices and Beverages § 146.146 Frozen concentrated orange juice. (a) Frozen concentrated orange juice is the food prepared by removing water from the juice of mature oranges as provided in § 146.135...

Concentrations of boron, molybdenum, and selenium in chinook salmon

Science.gov (United States)

Hamilton, Steven J.; Wiedmeyer, Raymond H.

1990-01-01

The concentrations of boron, molybdenum, and selenium in young chinook salmon Oncorhynchus tshawytscha were determined in three partial life cycle chronic toxicity studies. In each study, fish were exposed to a mixture of boron, molybdenum, selenate, and selenite in the proportions found in subsurface agricultural drainage water in the basin of the San Joaquin Valley, California. Tests were conducted in well water and in site-specific fresh and brackish waters. No boron or molybdenum was detected in fish exposed to concentrations as high as 6,046 μg boron/L and 193 μg molybdenum/L for 90 d in well water or fresh water; however, whole-body concentrations of selenium increased with increasing exposure concentrations in well water and fresh water, but not in brackish water. Concentrations of selenium in chinook salmon were strongly correlated with reduced survival and growth of fish in well water and with reduced survival in a 15-d seawater challenge test of fish from fresh water. Concentrations of selenium in fish seemed to reach a steady state after 60 d of exposure in well water or fresh water. Fish in brackish water had only background concentrations of selenium after 60 d of exposure, and no effects on survival and growth in brackish water or on survival in a 10-d seawater challenge test were exhibited. This lack of effect in brackish water was attributed to initiation of the study with advanced fry, which were apparently better able to metabolize the trace element mixture than were the younger fish used in studies with well water and fresh water. In all three experimental waters, concentration factors (whole-body concentration/waterborne concentration) for selenium decreased with increasing exposure concentrations, suggesting decreased uptake or increased excretion, or both, of selenium at the higher concentrations.

Installation package for concentrating solar collector panels

Science.gov (United States)

1978-01-01

The concentrating solar collector panels comprise a complete package array consisting of collector panels using modified Fresnel prismatic lenses for a 10 to 1 concentrating ratio, supporting framework, fluid manifolding and tracking drive system, and unassembled components for field erection.

Concentrations in the Local Association. 1. The southern concentrations NGC 2516, IC 2602, Centaurus-Lupus and Upper Scorpius

Energy Technology Data Exchange (ETDEWEB)

Eggen, O J [Cerro Tololo Inter-American Observatory, La Serena (Chile)

1983-07-01

Extensive intermediate band and H..beta.. observations and the available astrometry, have been used to support the suggestions that (1) several southern concentrations of stars are moving with the Pleiades and ..cap alpha.. Persei clusters (Local Association) and (2) the Local Association contains an appreciable percentage of the main-sequence stars near the Sun but the non-random distribution of the brighter association members focuses attention on a few concentrations, or 'clusters'. (3) All of the concentrations discussed here are larger than about 10 pc and the largest, in Lupus-Centaurus, is shown to be accompanied by A to G type main-sequence stars.

Changes in power and force generation during coupled eccentric-concentric versus concentric muscle contraction with training and aging

DEFF Research Database (Denmark)

Caserotti, Paolo; Aagaard, Per; Puggaard, Lis

2008-01-01

Age-related decline in maximal concentric muscle power is associated with frailty and functional impairments in the elderly. Compared to concentric contraction, mechanical muscle output is generally enhanced when muscles are rapidly pre-stretched (eccentric contraction), albeit less pronounced...... with increasing age. Exercise has been recommended to prevent loss of muscle power and function and recent guidelines indicate training program for increasing muscle power highly relevant for elderly subjects. This study examined the differences in muscle power, force and movement pattern during concentric......) and JH increased in training group (P age-related decline in muscle power and functional performance observed in the control subjects, while substantial gains...

Diagnostic system for measuring temperature, pressure, CO.sub.2 concentration and H.sub.2O concentration in a fluid stream

Science.gov (United States)

Partridge, Jr., William P.; Jatana, Gurneesh Singh; Yoo, Ji Hyung; Parks, II, James E.

2017-12-26

A diagnostic system for measuring temperature, pressure, CO.sub.2 concentration and H.sub.2O concentration in a fluid stream is described. The system may include one or more probes that sample the fluid stream spatially, temporally and over ranges of pressure and temperature. Laser light sources are directed down pitch optical cables, through a lens and to a mirror, where the light sources are reflected back, through the lens to catch optical cables. The light travels through the catch optical cables to detectors, which provide electrical signals to a processer. The processer utilizes the signals to calculate CO.sub.2 concentration based on the temperatures derived from H.sub.2O vapor concentration. A probe for sampling CO.sub.2 and H.sub.2O vapor concentrations is also disclosed. Various mechanical features interact together to ensure the pitch and catch optical cables are properly aligned with the lens during assembly and use.

Description and measurement of concentration problems in depressed patients.

Science.gov (United States)

Watts, F N; Sharrock, R

1985-05-01

Depressed patients commonly complain of concentration problems, yet these have seldom been the focus of systematic investigation. A structured interview about concentration problems was administered to a group of relatively severely depressed patients. Problems in reading and watching television were the most common, and were highly correlated with each other. Direct report of the number of concentration lapses on a reading task was the most generally satisfactory task-performance correlate of complaints of reading/TV concentration problems. Evidence both from this task and from the interview suggests that depressive concentration problems may often be due to 'mind-wandering'. The correlations with concentration problems with the severity and endogeneity of depression and with state anxiety were generally similar.

Calculated volumes of individual shield volcanoes at the young end of the Hawaiian Ridge

Science.gov (United States)

Robinson, Joel E.; Eakins, Barry W.

2006-03-01

High-resolution multibeam bathymetry and a digital elevation model of the Hawaiian Islands are used to calculate the volumes of individual shield volcanoes and island complexes (Niihau, Kauai, Oahu, the Maui Nui complex, and Hawaii), taking into account subsidence of the Pacific plate under the load of the Hawaiian Ridge. Our calculated volume for the Island of Hawaii and its submarine extent (213 × 10 3 km 3) is nearly twice the previous estimate (113 × 10 3 km 3), due primarily to crustal subsidence that had not been accounted for in the earlier work. The volcanoes that make up the Island of Hawaii (Mahukona, Kohala, Mauna Kea, Hualalai, Mauna Loa, Kilauea and Loihi) are generally considered to have been formed within the past million years, and our revised volume for the island indicates that magma supply rates are greater than previously estimated, 0.21 km 3/yr as opposed to ˜ 0.1 km 3/yr. This result also shows that compared with rates calculated for the Hawaiian Islands (0-6 Ma, 0.095 km 3/yr), the Hawaiian Ridge (0-45 Ma, 0.017 km 3/yr), and the Emperor Seamounts (45-80 Ma, 0.010 km 3/yr), magma supply rates have increased dramatically to build the Island of Hawaii.

Hawaiian Starlight: Sharing the Beauty of the Hawaiian Skies

Science.gov (United States)

Cuillandre, J. C.

Canada-France-Hawaii Telescope Corp. The summit of Mauna Kea (14,000 feet) offers the best viewing of the Cosmos in the northern hemisphere, and the film "Hawaiian Starlight" delivers a pure esthetic experience from the mountain into the Universe. Seven years in the making, this cinematic symphony reveals the spectacular beauty of the mountain and its connection to the Cosmos through the magical influence of time-lapse cinematography scored exclusively (no narration) with the awe-inspiring, critically acclaimed, Halo music by Martin O'Donnell and Michael Salvatori. Daytime and nighttime landscapes and skyscapes alternate with stunning true color images of the Universe captured by an observatory on Mauna Kea, all free of any computer generated imagery. An extended segment of the film will be presented at the Advanced Maui Optical and Space Surveillance Technologies Conference to celebrate the international year of Astronomy 2009, a global effort initiated by the IAU (International Astronomical Union) and UNESCO (United Nations Educational, Scientific and Cultural Organization) to help the citizens of the world rediscover their place in the Universe through the day- and night-time sky, and thereby engage a personal sense of wonder and discovery. Hawaiian Starlight is true to this commitment. The inspiration and technology of the film will be shortly presented by the film's director.

Using population genetic tools to develop a control strategy for feral cats (Felis catus) in Hawai'i

Science.gov (United States)

Hansen, H.; Hess, S.C.; Cole, D.; Banko, P.C.

2007-01-01

Population genetics can provide information about the demographics and dynamics of invasive species that is beneficial for developing effective control strategies. We studied the population genetics of feral cats on Hawai'i Island by microsatellite analysis to evaluate genetic diversity and population structure, assess gene flow and connectivity among three populations, identify potential source populations, characterise population dynamics, and evaluate sex-biased dispersal. High genetic diversity, low structure, and high number of migrants per generation supported high gene flow that was not limited spatially. Migration rates revealed that most migration occurred out of West Mauna Kea. Effective population size estimates indicated increasing cat populations despite control efforts. Despite high gene flow, relatedness estimates declined significantly with increased geographic distance and Bayesian assignment tests revealed the presence of three population clusters. Genetic structure and relatedness estimates indicated male-biased dispersal, primarily from Mauna Kea, suggesting that this population should be targeted for control. However, recolonisation seems likely, given the great dispersal ability that may not be inhibited by barriers such as lava flows. Genetic monitoring will be necessary to assess the effectiveness of future control efforts. Management of other invasive species may benefit by employing these population genetic tools. ?? CSIRO 2007.

Radon concentration, absorbed dose rate in air and concentration of natural radionuclides in soil in the Osaka district of Japan

International Nuclear Information System (INIS)

Megumi, K.; Matsunami, T.; Ishiyama, T.; Abe, M.; Kimura, S.; Yamazaki, K.; Tsujimoto, T.

1992-01-01

Radon concentrations in outdoor air at 18 sites in the Osaka district, in the central part of Japan's main island, were measured with electrostatic integrating radon monitors which were developed by Y Ikebe et al of the Osaka survey centre as part of a nationwide survey of radon indoors and outdoors in Japan conducted by the National Institute of Radiological Science. The mean radon concentration in outdoor air during 2-month periods was measured over a period of a year and a half. In addition, the absorbed dose rate in air and the concentration of natural radionuclides in soil were measured at 40 sites in Osaka Prefecture which is located in the central part of the Osaka district using thermoluminescence dosemeters and with gamma ray spectrometry, respectively. Radon concentration in outdoor air showed a seasonal pattern, reaching its maximum during the winter and its minimum during the summer, but this variation was not significant at the coastal sites. It was concluded that this variation is correlated with a seasonal wind which blows from the continental interior to the ocean in winter and in the opposite direction in summer, as well as with geographical factors. Radon concentration in outdoor air in the Osaka district ranged from 0.6 to 17.9 Bq.m -3 and mean annual radon concentration in outdoor air at the 18 sites ranged from 2.7 to 6.9 Bq.m -3 . It was discovered that radon concentration in outdoor air decreased with wind speed in both winter and summer. The absorbed dose rate in air ranged from 66 to 114 nGy.h -1 , and the concentration of 226 Ra in soil ranged from 20 to 60 Bq.kg -1 respectively. (author)

High indoor radon concentrations in some Swedish waterworks

International Nuclear Information System (INIS)

Aakerblom, G.; Hagberg, N.; Mjoenes, L.; Heiberg, A.

2002-01-01

High indoor radon concentrations in buildings used for water treatment are not uncommon. When raw water is processed in an open system radon escapes from the water to the indoor air of the premises. It is not unusual that the staff of the waterworks have their offices in the building where the water is processed. If large volumes of water are processed and the evaporated radon can reach the workplaces the indoor radon concentration can be very high even if the radon concentration of the raw water is moderate. Groundwaters from aquifers in bedrock and soil and surface water that has been infiltrated through deposits of sand or gravel have the potential to cause high indoor radon levels. In surface water emanating directly from a lake or a river the radon concentrations are normally too low to cause problems. Three waterworks in central Sweden have been studied, Ludvika, Fredriksberg and Kolbaeck. The radon concentrations in the raw water of these waterworks are from 85 Bq/l to 300 Bq/l. Average indoor radon concentrations exceeding 17,000 Bq/m 3 have been measured in Ludvika with peaks of almost 37,000 Bq/m 3 . In Kolbaeck radon concentrations up to 56,000 Bq/m 3 have been measured. It is quite possible that employees of waterworks can receive doses exceeding 20 mSv per year (calculated according to ICRP:s dose conversion convention). Measurements of radon and gamma radiation from the waterworks are reported and methods to lower the indoor radon concentrations are discussed. (author)

Effects of Low Phytanic Acid-Concentrated DHA on Activated Microglial Cells: Comparison with a Standard Phytanic Acid-Concentrated DHA.

Science.gov (United States)

Ruiz-Roso, María Belén; Olivares-Álvaro, Elena; Quintela, José Carlos; Ballesteros, Sandra; Espinosa-Parrilla, Juan F; Ruiz-Roso, Baltasar; Lahera, Vicente; de Las Heras, Natalia; Martín-Fernández, Beatriz

2018-05-30

Docosahexaenoic acid (DHA, 22:6 n-3) is an essential omega-3 (ω-3) long chain polyunsaturated fatty acid of neuronal membranes involved in normal growth, development, and function. DHA has been proposed to reduce deleterious effects in neurodegenerative processes. Even though, some inconsistencies in findings from clinical and pre-clinical studies with DHA could be attributed to the presence of phytanic acid (PhA) in standard DHA treatments. Thus, the aim of our study was to analyze and compare the effects of a low PhA-concentrated DHA with a standard PhA-concentrated DHA under different neurotoxic conditions in BV-2 activated microglial cells. To this end, mouse microglial BV-2 cells were stimulated with either lipopolysaccharide (LPS) or hydrogen peroxide (H 2 O 2 ) and co-incubated with DHA 50 ppm of PhA (DHA (PhA:50)) or DHA 500 ppm of PhA (DHA (PhA:500)). Cell viability, superoxide anion (O 2 - ) production, Interleukin 6 (L-6), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), glutathione peroxidase (GtPx), glutathione reductase (GtRd), Caspase-3, and the brain-derived neurotrophic factor (BDNF) protein expression were explored. Low PhA-concentrated DHA protected against LPS or H 2 O 2 -induced cell viability reduction in BV-2 activated cells and O 2 - production reduction compared to DHA (PhA:500). Low PhA-concentrated DHA also decreased COX-2, IL-6, iNOS, GtPx, GtRd, and SOD-1 protein expression when compared to DHA (PhA:500). Furthermore, low PhA-concentrated DHA increased BDNF protein expression in comparison to DHA (PhA:500). The study provides data supporting the beneficial effect of low PhA-concentrated DHA in neurotoxic injury when compared to a standard PhA-concentrated DHA in activated microglia.

Concentration dependence of biotransformation in fish liver S9: Optimizing substrate concentrations to estimate hepatic clearance for bioaccumulation assessment.

Science.gov (United States)

Lo, Justin C; Allard, Gayatri N; Otton, S Victoria; Campbell, David A; Gobas, Frank A P C

2015-12-01

In vitro bioassays to estimate biotransformation rate constants of contaminants in fish are currently being investigated to improve bioaccumulation assessments of hydrophobic contaminants. The present study investigates the relationship between chemical substrate concentration and in vitro biotransformation rate of 4 environmental contaminants (9-methylanthracene, pyrene, chrysene, and benzo[a]pyrene) in rainbow trout (Oncorhynchus mykiss) liver S9 fractions and methods to determine maximum first-order biotransformation rate constants. Substrate depletion experiments using a series of initial substrate concentrations showed that in vitro biotransformation rates exhibit strong concentration dependence, consistent with a Michaelis-Menten kinetic model. The results indicate that depletion rate constants measured at initial substrate concentrations of 1 μM (a current convention) could underestimate the in vitro biotransformation potential and may cause bioconcentration factors to be overestimated if in vitro biotransformation rates are used to assess bioconcentration factors in fish. Depletion rate constants measured using thin-film sorbent dosing experiments were not statistically different from the maximum depletion rate constants derived using a series of solvent delivery-based depletion experiments for 3 of the 4 test chemicals. Multiple solvent delivery-based depletion experiments at a range of initial concentrations are recommended for determining the concentration dependence of in vitro biotransformation rates in fish liver fractions, whereas a single sorbent phase dosing experiment may be able to provide reasonable approximations of maximum depletion rates of very hydrophobic substances. © 2015 SETAC.

Nitrate concentrations in soil solutions below Danish forests

DEFF Research Database (Denmark)

Callesen, Ingeborg; Raulund-Rasmussen, Karsten; Gundersen, Per

1999-01-01

leaching in relation to land-use, a national monitoring programme has established sampling routines in a 7x7 km grid including 111 points in forests. During winters of 1986-1993, soil samples were obtained from a depth of 0-25, 25-50, 50-75 and 75-100 cm. Nitrate concentrations in soil solutions were...... species. A few sites deviated radically from the general pattern of low concentrations. The elevated concentrations recorded there were probably caused by high levels of N deposition due to emission from local sources or temporal disruptions of the N cycle. The nitrate concentration in the soil solution...

Microwave Pretreatment for Thiourea Leaching for Gold Concentrate

Directory of Open Access Journals (Sweden)

Nag-Choul Choi

2017-10-01

Full Text Available In this research, we studied the use of microwave pretreatment to enhance the efficiency of Au leaching from gold concentrate. The gold concentrate was pretreated using microwaves with different irradiation time. The sample temperature was increased up to 950 °C by the microwave irradiation. A scanning electron microscope-energy dispersive spectrometer showed the evolution of microcracks and the reduction of sulfur on the mineral surface. X-ray diffraction data also showed the mineral phase shift from pyrite to hematite or pyrrhotite. A leaching test was conducted for the microwave-treated and untreated gold concentrates using thiourea. Although the thiourea leaching recovered 80% of Au from the untreated concentrate, from the treated concentration, the Au could be recovered completely. Au leaching efficiency increased as the microwave irradiation time increased, as well as with a higher composition of thiourea.

Ownership Concentration and Market Value of European Banks

DEFF Research Database (Denmark)

Busta, Ildura; Sinani, Evis; Thomsen, Steen

2014-01-01

This paper investigates the relationship between ownership concentration and market value of European banks, and the role of the institutional environment in shaping this relationship. Using GMM dynamic estimator on a sample of European banks over a 13-year period (1993–2005) we find on average...... concentration is positive in Scandinavia. We propose that, besides the legal protection of small investors, the differences in the impact of ownership concentration across the countries could be due to the identity of the predominant owners, i.e. financial institutions in Germany and trusts and foundations...... a negative effect of ownership concentration on bank value, measured by Tobin's Q. However, this effect varies across different institutional settings; while higher ownership concentration results in a lower bank value particularly in the countries belonging to German legal family, the impact of ownership...

Influence of surfactant concentration on nanohydroxyapatite growth

Indian Academy of Sciences (India)

Nanohydroxyapatite particles with different morphologies were synthesized through a microwave coupled hydrothermal method using CTAB as a template. A successful synthesis of nanosized HAP spheres, rods and fibres is achieved through this method by controlling the concentration of the surfactant. The concentration ...

Filterability and Sludge Concentration in Membrane Bioreactors

NARCIS (Netherlands)

Lousada-Ferreira, M.

2011-01-01

The Thesis entitled “Filterability and Sludge Concentration in Membrane Bioreactors” aims at explaining the relation between Mixed Liquid Suspended Solids (MLSS) concentration, the amount of solids in the wastewater being treated, also designated as sludge, and filterability, being the ability of

Cylindrical acoustic levitator/concentrator

Science.gov (United States)

Kaduchak, Gregory; Sinha, Dipen N.

2002-01-01

A low-power, inexpensive acoustic apparatus for levitation and/or concentration of aerosols and small liquid/solid samples having particulates up to several millimeters in diameter in air or other fluids is described. It is constructed from a commercially available, hollow cylindrical piezoelectric crystal which has been modified to tune the resonance frequency of the breathing mode resonance of the crystal to that of the interior cavity of the cylinder. When the resonance frequency of the interior cylindrical cavity is matched to the breathing mode resonance of the cylindrical piezoelectric transducer, the acoustic efficiency for establishing a standing wave pattern in the cavity is high. The cylinder does not require accurate alignment of a resonant cavity. Water droplets having diameters greater than 1 mm have been levitated against the force of gravity using; less than 1 W of input electrical power. Concentration of aerosol particles in air is also demonstrated.

Pressure leaching of chalcopyrite concentrate

Science.gov (United States)

Aleksei, Kritskii; Kirill, Karimov; Stanislav, Naboichenko

2018-05-01

The results of chalcopyrite concentrate processing using low-temperature and high-temperature sulfuric acid pressure leaching are presented. A material of the following composition was used, 21.5 Cu, 0.1 Zn, 0.05 Pb, 0.04 Ni, 26.59 S, 24.52 Fe, 16.28 SiO2 (in wt.%). The influence of technological parameters on the degree of copper and iron extraction into the leach solution was studied in the wide range of values. The following conditions were suggested as the optimal for the high-temperature pressure leaching: t = 190 °C, PO2 = 0.5 MPa, CH2SO4 = 15 g/L, L:S = 6:1. At the mentioned parameters, it is possible to extract at least 98% Cu from concentrate into the leaching solution during 100 minutes. The following conditions were suggested as optimal for the low-temperature pressure leaching: t = 105 °C, PO2 = 1.3-1.5 MPa, CH2SO4 = 90 g/L, L:S = 10:1. At the mentioned parameters, it is possible to extract up to 83% Cu from the concentrate into the leach solution during 300-360 minutes.

[Nitrate concentrations in tap water in Spain].

Science.gov (United States)

Vitoria, Isidro; Maraver, Francisco; Sánchez-Valverde, Félix; Armijo, Francisco

2015-01-01

To determine nitrate concentrations in drinking water in a sample of Spanish cities. We used ion chromatography to analyze the nitrate concentrations of public drinking water in 108 Spanish municipalities with more than 50,000 inhabitants (supplying 21,290,707 potential individuals). The samples were collected between January and April 2012. The total number of samples tested was 324. The median nitrate concentration was 3.47 mg/L (range: 0.38-66.76; interquartile range: 4.51). The water from 94% of the municipalities contained less than 15 mg/L. The concentration was higher than 25mg/L in only 3 municipalities and was greater than 50mg/L in one. Nitrate levels in most public drinking water supplies in municipalities inhabited by almost half of the Spanish population are below 15 mg/L. Copyright © 2014 SESPAS. Published by Elsevier Espana. All rights reserved.

Soil-to-plant concentration factors for radiological assessments

International Nuclear Information System (INIS)

Ng, Y.C.; Thompson, S.E.; Colsher, C.S.

1982-09-01

This report presents the results of a literature review to derive soil-to-plant concentration factors to predict the concentration of a radionuclide in plants from that in soil. The concentration factor, B/sub v/ is defined as the ratio of the concentration of a nuclide in the edible plant part to that in dry soil. CR (the concentration ratio) is similarly defined to denote the concentration factor for dry feed consumed by livestock. B/sub v/ and CR values are used to assess the dose from radionuclides deposited onto soil and transferred into crop plants via roots. Approaches for deriving B/sub v/ and CR values are described, and values for food and feed are tabulated for individual elements. The sources of uncertainty are described, and the factors that contribute to the inherent variability of the B/sub v/ and CR values are discussed. Summary tables of elemental B/sub v/ and CR values and statistical parameters that characterize their distributions provide a basis for a systematic updating of many of the B/sub v/ values in Regulatory Guide 1.109. They also provide a basis for selecting B/sub v/ and CR values for other applications that involve the use of equilibrium models to predict the concentration of radionuclides in plants from that in soil

Fluorine concentration profiles in archaeological bone

International Nuclear Information System (INIS)

Coote, G.E.; Sparks, R.J.

1981-01-01

The nuclear microprobe at the Institute of Nuclear Sciences was applied to the measurement of radial concentration profiles of fluorine, in transverse slices of archaeological bone from humans, moas, and other animals. A beam of 2.5 MeV protons was focused to a rectangular spot 250 microns by 50 microns, traversed along a radial line 3mm long, and gamma rays of 5-7 MeV from the reaction 19 F(p, α#betta#) 16 O were detected in a large sodium iodide crystal. Bombardment caused no detectable loss of fluorine from the bone. Measured profiles display a wide variety of shapes and maximum concentrations. In bones which had been exposed to ground water the fluorine concentration usually increases from the centre towards the surface, sometimes by as much as a factor of eight. The concentration at the surface is usually in the range 0.2 to 1%, though in moa bone from a limestone cave it is only 0.025%. Once a quantitative method of analysis has been developed, based on the shape of the profile rather than its magnitude, these profiles might be useful for dating bone. In the meantime, they could be used to distinguish bones of different ages from a common site

Concentration dependent hydrogen diffusion in tungsten

Energy Technology Data Exchange (ETDEWEB)

Ahlgren, T., E-mail: tommy.ahlgren@helsinki.fi; Bukonte, L.

2016-10-15

The diffusion of hydrogen in tungsten is studied as a function of temperature, hydrogen concentration and pressure using Molecular Dynamics technique. A new analysis method to determine diffusion coefficients that accounts for the random oscillation of atoms around the equilibrium position is presented. The results indicate that the hydrogen migration barrier of 0.25 eV should be used instead of the presently recommended value of 0.39 eV. This conclusion is supported by both experiments and density functional theory calculations. Moreover, the migration volume at the saddle point for H in W is found to be positive: ΔV{sub m} ≈ 0.488 Å{sup 3}, leading to a decrease in the diffusivity at high pressures. At high H concentrations, a dramatic reduction in the diffusion coefficient is observed, due to site blocking and the repulsive H-H interaction. The results of this study indicates that high flux hydrogen irradiation leads to much higher H concentrations in tungsten than expected. - Highlights: • The recommended value of 0.39 eV for the H in W migration barrier should be changed to 0.25 eV. • The random oscillation of atoms around the equilibrium position can be dealt with in diffusion simulations. • Hydrogen diffusion in tungsten is highly concentration dependent.

Improved ATIR concentrator photovoltaic module

Science.gov (United States)

Adriani, Paul M.; Mao, Erwang

2013-09-01

Novel aggregated total internal reflection (ATIR) concentrator photovoltaic module design comprises 2-D shaped primary and secondary optics that effectively combine optical efficiency, low profile, convenient range of acceptance angles, reliability, and manufacturability. This novel optical design builds upon previous investigations by improving the shapes of primary and secondary optics to enable improved long-term reliability and manufacturability. This low profile, low concentration (5x to 10x) design fits well with one-axis trackers that are often used for flat plate crystalline silicon photovoltaic modules in large scale ground mount installations. Standard mounting points, materials, and procedures apply without changes from flat plate modules.

Correlation Of Giant Nuclei With Cloud Droplet Concentration

Science.gov (United States)

Jha, V.; Hudson, J. G.; Noble, S.

2011-12-01

The effect of giant nuclei (GN; larger than 1 micrometer particles produced by wind on the ocean surface) on warm rain has been debated for decades. During RICO (Rain in Cumulus over the Ocean) Hudson et al. (2011) found a negative correlation (R) between CCN concentrations at 1% supersaturation (S) and large cloud droplet concentrations (Fig. 1A). This reversal from positive R for CCN with total (or small) cloud droplet concentrations (left side of Fig. 1A) was explained by the greater competition for condensate, which thus limits droplet sizes when CCN concentrations are higher. The negative R increased in magnitude with altitude, and the droplet size where the maximum negative R occurred increased with altitude (Fig. 1A). However, at all altitudes this negative R decreased in magnitude for even larger cloud and drizzle drops (right side of Fig. 1A except highest altitude). The decrease in magnitude of the negative R was greater for increasing drop sizes at higher altitudes. Thus, at the higher altitudes, R for CCN with large drizzle drops was of low negative magnitude and even positive at the highest RICO altitudes. The disparity between CCN and drizzle drop concentrations precluded a causal relationship. But the high R between GN and drizzle drop concentrations at the highest altitudes (Fig. 1B) and the comparable concentrations indicated that GN were engendering drizzle. This is supported by the increasing R with altitude of the GN-drizzle drop R (right side of Fig. 1B). The conclusion of a GN-drizzle connection is also supported by the fact that CCN concentrations should inhibit drizzle. This analysis of Hudson et al. (2011) is here expanded to include correlations of CCN concentrations at lower S with cloud and drizzle drop concentrations to investigate intermediate relationships; i.e., between large nuclei (i.e., 0.1-1 micrometer; critical S 0.1-0.01%) and drizzle drop concentrations. A shortcoming of Hudson et al. (2011) was the small number of high

Beryllium concentration in pharyngeal tonsils in children

Directory of Open Access Journals (Sweden)

Ewa Nogaj

2014-06-01

Full Text Available Power plant dust is believed to be the main source of the increased presence of the element beryllium in the environment which has been detected in the atmospheric air, surface waters, groundwater, soil, food, and cigarette smoke. In humans, beryllium absorption occurs mainly via the respiratory system. The pharyngeal tonsils are located on the roof of the nasopharynx and are in direct contact with dust particles in inhaled air. As a result, the concentration levels of beryllium in the pharyngeal tonsils are likely to be a good indicator of concentration levels in the air. The presented study had two primary aims: to investigate the beryllium concentration in pharyngeal tonsils in children living in southern Poland, and the appropriate reference range for this element in children’s pharyngeal tonsils. Pharyngeal tonsils were extracted from a total of 379 children (age 2–17 years, mean 6.2 ± 2.7 years living in southern Poland. Tonsil samples were mineralized in a closed cycle in a pressure mineralizer PDS 6, using 65% spectrally pure nitric acid. Beryllium concentration was determined using the ICP-AES method with a Perkin Elmer Optima 5300DVTM. The software Statistica v. 9 was used for the statistical analysis. It was found that girls had a significantly greater beryllium concentration in their pharyngeal tonsils than boys. Beryllium concentration varies greatly, mostly according to the place of residence. Based on the study results, the reference value for beryllium in pharyngeal tonsils of children is recommended to be determined at 0.02–0.04 µg/g.

Calcium concentration in the CAPD dialysate

DEFF Research Database (Denmark)

Bro, S; Brandi, L; Daugaard, H

1998-01-01

OBJECTIVE: To evaluate risk/benefit of various continuous ambulatory peritoneal dialysis (CAPD) dialysate calcium concentrations. DATA SOURCES: A review of the literature on the effects of various CAPD dialysate Ca concentrations on plasma Ca, plasma phosphate, plasma parathyroid hormone (PTH......), doses of calcium carbonate, doses of vitamin D analogs, and requirements of aluminum-containing phosphate binders. STUDY SELECTION: Eleven studies of nonselected CAPD patients, and 13 studies of CAPD patients with hypercalcemia were reviewed. RESULTS: In nonselected CAPD patients, treatment...... with a reduced dialysate Ca concentration (1.00, 1.25, or 1.35 mmol/L) improved the tolerance to calcium carbonate and/or vitamin D metabolites and reduced the need for Al-containing phosphate binders. When using dialysate Ca 1.25 or 1.35 mmol/L, the initial decrease of plasma Ca and increase of PTH could easily...

Stress Concentration around Holes in Anistropic Sheets

DEFF Research Database (Denmark)

Krenk, Steen

1979-01-01

The formulation of stress concentration problems of plane anisotropic elasticity in terms of integral equations is discussed. First the singular solutions of a concentrated force and a dislocation are formulated so that they remain valid in the case of double roots. The distribution of singularit...

Radon concentration distribution mapping in a small detached house

International Nuclear Information System (INIS)

Muellerova, Monika; Moravcsik, Attila; Holy, Karol; Hutka, Miroslav; Hola, Olga

2013-01-01

Radon activity concentration was investigated in an older, single storey detached house. The rooms of the house are in contact with the bedrock. The house is fitted with plastic windows and populated mostly during the summer. Integral (Raduet) and continuous (AlphaGUARD) methods were used to measure the radon activity concentration. Average radon and thoron activity concentrations in the house were 150 Bq/m 3 and 40 Bq/m 3 , respectively. The impact of the house occupancy on radon activity concentration was significant only during the summer months when a decrease of radon activity concentration was recorded due to an increased ventilation rate. In the autumn and winter months, the impact of the house occupancy on radon activity concentration was relatively small - up to 20 %. The increases in radon activity concentration after the room had been thoroughly ventilated were analysed in order to estimate the ventilation rate and the rate of radon supply into the house. (orig.)

Theory of Concentrated Vortices

DEFF Research Database (Denmark)

Alekseenko, Sergey; Kuibin, Pavel; Okulov, Valery

This book presents comprehensive and authoritative coverage of the wide field of concentrated vortices observed in nature and technique. The methods for research of their kinematics and dynamics are considered. Special attention is paid to the flows with helical symmetry. The authors have describ...

Aluminum concentration in hydrangeas

International Nuclear Information System (INIS)

Yanagawa, M.; Haruyama, Y.; Saito, M.

2008-01-01

We have been trying to measure concentration of aluminum in Ajisai, Hydrangea macrophylla for these days. But due to bad luck, we have encountered detector trouble for two years in a low. Thus, we have few data to analyze and obtained quite limited results. (author)

Tube collector with integrated tracking parabolic concentrator

Energy Technology Data Exchange (ETDEWEB)

Grass, C.; Benz, N.; Hacker, Z.; Timinger, A. [ZAE Bayern, Bavarian Centre for Applied Energy Research, Muenchen (Germany)

2000-07-01

Low concentrating CPC collectors usually do not track the sun and are mounted in east-west direction with a latitude dependent slope angle. They are most suitable for maximum working temperatures up to 200 250 deg. C. We present a novel evacuated tube-collector with a trough-like concentrating mirror. Single-axis tracking of the mirror is realized with a magnetic mechanism. The mirror is mounted inside the evacuated tube and hence protected from environmental influences. One axis tracking in combination with a small acceptance angle allows for higher concentration as compared to non-tracking concentrating collectors. Ray-tracing analysis shows a half acceptance angle of about 5 deg. at a geometrical concentration ratio of 3.2. The losses of evacuated tube collectors are dominated by the radiation losses of the absorber. Hence, reducing the absorber size can lead to higher efficiencies at high operating temperature levels. With the presented collector we aim for operating temperatures up to 400 deg. C. At temperatures of 300 deg. C we expect efficiencies of 65 %. This allows for application in industrial process heat generation, high efficient solar cooling and power generation. A first prototype was tested at the ZAE Bayern. The optical efficiency was measured to be 75 %. (au)

Complex concentrate pretreatment

International Nuclear Information System (INIS)

Lokken, R.O.; Scheele, R.D.; Strachan, D.M.; Toste, A.P.

1991-03-01

After removal of the transuranics (TRU) by the TRUEX process, complex concentrate waste will be grouted for final storage. The purpose of this project, conducted at the Pacific Northwest Laboratory, is to support a future decision to grout the complexant waste without destruction of the organic contents. It has been demonstrated that grouts with acceptable parameters for the Transportable Grout Facility can be made using actual waste. The acceptability of these grouts from a regulatory view seems to be less of a problem than previously. None of the organics found in the waste have been found on the EPA hazardous chemicals list. Two potential problems with the processing of the complex concentrate wastes were identified during the use of the TRUEX process on samples of several milliliters. One was the amount of foam that is generated during acid addition to the alkaline waste. Some of this foam appears to be of a waxy nature but does redissolve when the waste is strongly acid. The second potential problem is that noticeable amounts of NO x gases are generated. No quantitative measure of the NO x gas generation was made. The problem relates to processing the waste in B-plant where there are no facilities to handle NO x gases. 5 refs., 4 figs., 4 tabs

Effects of barium concentration on oropharyngeal swallow timing measures.

Science.gov (United States)

Stokely, Shauna L; Molfenter, Sonja M; Steele, Catriona M

2014-02-01

Videofluoroscopy is commonly used for evaluating oropharyngeal swallowing but requires radiopaque contrast (typically barium). Prior studies suggest that some aspects of swallowing, including timing measures of oral and pharyngeal bolus transit, vary depending on barium concentration. The aim of our study was to identify timing differences in healthy swallowing between "thin" (40 % w/v concentration) and "ultrathin" (22 % w/v concentration) barium solutions. Twenty healthy adults (Ten women; mean age = 31 years) each performed a series of three noncued 5-ml swallows each of ultrathin and thin liquid barium solutions in videofluoroscopy. Timing measures were compared between barium concentrations using a mixed-model ANOVA. The measures of interest were stage transition duration, pharyngeal transit time, and duration of upper esophageal sphincter opening. Significant differences were observed in the timing measures of swallowing with respect to barium concentration. In all cases, longer durations were seen with the higher barium concentration. Barium concentration influences timing parameters in healthy swallowing, even between ultrathin and thin concentrations. Clinicians need to understand and control for the impact of different barium stimuli on swallowing physiology.

[Preoperatively administered flomoxef sodium concentration in aqueous humor].

Science.gov (United States)

Miyamoto, Mariko; Watanabe, Yoichiro; Mizuki, Nobuhisa

2007-04-01

We intravenously administered flomoxef sodium (FMOX) 0.5-3.5 hours before cataract surgery and measured the concentration of the agent in the aqueous humor to investigate its penetration into the aqueous humor and its efficacy in the prevention of postoperative endophthalmitis. 56 patients who underwent cataract surgery were enrolled in this study. They received 1 g FMOX via a 20-minute intravenous drip beginning 0.5-3.5 hours before the operation. Aqueous humor was aspirated from the anterior chamber and assayed for FMOX concentration using high-performance liquid chromatography. The mean intraoperative FMOX concentrations in the patients' aqueous humor were 0.79 +/- 0.24 microg/ml (administered 3.5 hours before surgery)--1.47 0.79 microg/ml (administered 1.5 hours before surgery). These concentrations administered 0.5-3.0 hours before surgery sufficiently exceeded the minimum inhibitory concentration (MIC) 90 values against Staphylococcus epidermidis, Staphylococcus aureus and Propionibacterium acnes, but did not achieve the MIC90 values against Enterococcus faecalis and Pseudomonas aeruginosa. The FMOX concentrations in the aqueous humor sampling were adequate to kill bacteria in vitro. This drug may be efficacious in the prevention of postoperative endophthalmitis in patients undergoing cataract surgery.

Radon concentration in dwellings of Lanzarote (Canary Islands)

Energy Technology Data Exchange (ETDEWEB)

Pinza, C.; Armas, J.H. [La Laguna Univ., Tenerife (Spain). Faculty of Medicine; Poffijn, A. [Ghent Rijksuniversiteit (Belgium). Lab. voor Kernfysica

1997-07-01

A total of 126 radon passive dosemeters were distributed in 63 dwellings on the island of Lanzarote (Canary Islands) to measure the indoor radon concentration in the period April-June 1994. The mean overall indoor concentration was 50 Bq.m{sup -3} with a standard deviation of 17 Bq.m{sup -3}. Applying the conversion factor for the effective dose, recommended by ICRP 65, this results in a mean effective dose of 0.75 mSv.y{sup -1}. The mean radon concentration in single-family houses proves to be higher at the ground floor than in upper levels. The mean radon concentration obtained in bedrooms is higher than in living-rooms, independently of the floor they are located at. Statistically significant differences in the mean radon concentration have been found depending on the soil permeability (P = 0.001) and building materials used (P 0.0006). (author).

Radon concentration in dwellings of Lanzarote (Canary Islands)

International Nuclear Information System (INIS)

Pinza, C.; Armas, J.H.; Poffijn, A.

1997-01-01

A total of 126 radon passive dosemeters were distributed in 63 dwellings on the island of Lanzarote (Canary Islands) to measure the indoor radon concentration in the period April-June 1994. The mean overall indoor concentration was 50 Bq.m -3 with a standard deviation of 17 Bq.m -3 . Applying the conversion factor for the effective dose, recommended by ICRP 65, this results in a mean effective dose of 0.75 mSv.y -1 . The mean radon concentration in single-family houses proves to be higher at the ground floor than in upper levels. The mean radon concentration obtained in bedrooms is higher than in living-rooms, independently of the floor they are located at. Statistically significant differences in the mean radon concentration have been found depending on the soil permeability (P = 0.001) and building materials used (P 0.0006). (author)

Compact Flyeye concentrator with improved irradiance uniformity on solar cell

Science.gov (United States)

Zhuang, Zhenfeng; Yu, Feihong

2013-08-01

A Flyeye concentrator with improved irradiance distribution on the solar cell in a concentrator photovoltaic system is proposed. This Flyeye concentrator is composed of four surfaces: a refractive surface, mirror surface, freeform surface, and transmissive surface. Based on the principles of geometrical optics, the contours of the proposed Flyeye concentrator are calculated according to Fermat's principle, the edge-ray principle, and the ray reversibility principle without solving partial differential equations or using an optimization algorithm, therefore a slope angle control method is used to construct the freeform surface. The solid model is established by applying a symmetry of revolution around the optical axis. Additionally, the optical performance for the Flyeye concentrator is simulated and analyzed by Monte-Carlo method. Results show that the Flyeye concentrator optical efficiency of >96.2% is achievable with 1333× concentration ratio and ±1.3 deg acceptance angle, and 1.3 low aspect ratio (average thickness to entry aperture diameter ratio). Moreover, comparing the Flyeye concentrator specification to that of the Köhler concentrator and the traditional Fresnel-type concentrator, results indicate that this concentrator has the advantages of improved uniformity, reduced thickness, and increased tolerance to the incident sunlight.

Swift recovery of Sphagnum nutrient concentrations after excess supply.

Science.gov (United States)

Limpens, Juul; Heijmans, Monique M P D

2008-08-01

Although numerous studies have addressed the effects of increased N deposition on nutrient-poor environments such as raised bogs, few studies have dealt with to what extent, and on what time-scale, reductions in atmospheric N supply would lead to recovery of the ecosystems in question. Since a considerable part of the negative effects of elevated N deposition on raised bogs can be related to an imbalance in tissue nutrient concentrations of the dominant peat-former Sphagnum, changes in Sphagnum nutrient concentration after excess N supply may be used as an early indicator of ecosystem response. This study focuses on the N and P concentrations of Sphagnum magellanicum and Sphagnum fallax before, during and after a factorial fertilization experiment with N and P in two small peatlands subject to a background bulk deposition of 2 g N m(-2) year(-1). Three years of adding N (4.0 g N m(-2) year(-1)) increased the N concentration, and adding P (0.3 g P m(-2) year(-1)) increased the P concentration in Sphagnum relative to the control treatment at both sites. Fifteen months after the nutrient additions had ceased, N concentrations were similar to the control whereas P concentrations, although strongly reduced, were still slightly elevated. The changes in the N and P concentrations were accompanied by changes in the distribution of nutrients over the capitulum and the stem and were congruent with changes in translocation. Adding N reduced the stem P concentration, whereas adding P reduced the stem N concentration in favor of the capitulum. Sphagnum nutrient concentrations quickly respond to reductions in excess nutrient supply, indicating that a management policy aimed at reducing atmospheric nutrient input to bogs can yield results within a few years.

Study on calculation models and distribution rules of the radon concentration and its progenies concentration in blind roadway with forced-exhaust ventilation

International Nuclear Information System (INIS)

Ye Yongjun; Wang Liheng; Zhou Xinghuo; Li Xiangyang; Zhong Yongming; Wang Shuyun; Ding Dexin

2014-01-01

The forced-exhaust ventilation is an important way to control the concentration of radon and its progenies in long-distance blind driving roadway. It is of great significance for guiding the design of ventilation and radiation protection to study distribution characteristics of the concentration of radon and its progenies in the wind of roadway adopting the forced-exhaust ventilation. Therefore, according to the decay relationship of radon and its progenies, a simplified mathematical calculation model was built, which relates to the radon activity concentration and the potential alpha concentration of radon progenies. The paper also analyzed the sources of radon and its progenies in the limited space of the blind roadway. Then, based on the turbulence mass transfer theory of ventilation air flow, the paper established mathematical calculation models of distribution characteristics of the radon activity concentration and the potential alpha concentration of radon progenies in blind roadway with forced-exhaust ventilation, respectively. Finally, the paper applied the calculation models to a special blind roadway, and discussed the influence of the ventilation air inflow and the radon exhalation rate of rock wall on the distribution of radon concentration and the potential alpha concentration of radon progenies in the roadway. Meanwhile, some protective measurements were put forward to reduce the radiation dose of worker caused by radon and its progenies in the blind roadway. (authors)

MCB-2 concentration meter for boric acid

International Nuclear Information System (INIS)

Lisecki, W.

1978-01-01

The principles are explained of the thermal neutron absorption method for monitoring boric acid concentration in the WWER type reactor coolant. The design principles and the characteristics of four variants are described of the MSB-2 type boric acid concentration monitor developed by IBJ. (B.S.)

Magma migration and resupply during the 1974 summit eruptions of Kilauea Volcano, Hawaii

Science.gov (United States)

Lockwood, John P.; Tilling, Robert I.; Holcomb, Robin T.; Klein, Fred W.; Okamura, Arnold T.; Peterson, Donald W.

1999-01-01

The purpose of this paper is to present a complete account of contrasting yet related eruptions, thus filling a gap in the published narratives of recent activity of Kilauea; and to examine their significance within a broader context of regional magmatic and eruptive dynamics. We have gained a historical perspective and can view these three eruptions within a multidecade context of the eruptive behavior of not only Kilauea, but also of the adjacent Mauna Loa.

Tracking integration in concentrating photovoltaics using laterally moving optics.

Science.gov (United States)

Duerr, Fabian; Meuret, Youri; Thienpont, Hugo

2011-05-09

In this work the concept of tracking-integrated concentrating photovoltaics is studied and its capabilities are quantitatively analyzed. The design strategy desists from ideal concentration performance to reduce the external mechanical solar tracking effort in favor of a compact installation, possibly resulting in lower overall cost. The proposed optical design is based on an extended Simultaneous Multiple Surface (SMS) algorithm and uses two laterally moving plano-convex lenses to achieve high concentration over a wide angular range of ±24°. It achieves 500× concentration, outperforming its conventional concentrating photovoltaic counterparts on a polar aligned single axis tracker.

Effect of cooking on radionuclide concentrations in waterfowl tissues

International Nuclear Information System (INIS)

Halford, D.K.

1983-01-01

Twenty-four commercially raised mallar ducks (Anas platyrhyncos) were released at the Test Reactor Area radioactive leaching ponds, and subsequently collected 56 to 188 days later. Liver, gizzard, and carcass were analyzed for radionuclide concentrations before and after cooking. Significant decreases (P 137 Cs, 134 Cs, 60 Co, 140 La and /sup 110m/Ag concentrations in carcass and liver samples occurred after cooking. Radionuclide concentrations in gizzard showed no significant change in radionuclide concentrations after cooking. Cesium-134 and 137 Cs concentrations decreased by 27% in carcass after cooking and reduced the dose commitment to man by that amount

Odor concentration invariance by chemical ratio coding

Directory of Open Access Journals (Sweden)

Naoshige Uchida

2008-08-01

Full Text Available Many animal species rely on chemical signals to extract ecologically important information from the environment. Yet in natural conditions chemical signals will frequently undergo concentration changes that produce differences in both level and pattern of activation of olfactory receptor neurons. Thus, a central problem in olfactory processing is how the system is able to recognize the same stimulus across different concentrations. To signal species identity for mate recognition, some insects use the ratio of two components in a binary chemical mixture to produce a code that is invariant to dilution. Here, using psychophysical methods, we show that rats also classify binary odor mixtures according to the molar ratios of their components, spontaneously generalizing over at least a tenfold concentration range. These results indicate that extracting chemical ratio information is not restricted to pheromone signaling and suggest a general solution for concentration-invariant odor recognition by the mammalian olfactory system.

Studies on osmotic concentration of radioactive effluents

International Nuclear Information System (INIS)

Thomas, K.C.; Ramachandhran, V.; Misra, B.M.

1986-01-01

The potential of direct osmosis for concentrating radioactive effluents is examined on the laboratory scale. Studies were carried out using asymmetric cellulose acetate membranes of a range of porosities under varying salinity gradients. A suitable bench scale osmotic concentrator employing tubular membrane systems has been fabricated and tested. An attempt to understand the mechanism of water permeation under osmotic and hydrostatic gradients has been made based on the irreversible thermodynamic approach. The solute separation of sodium chloride and radionuclides under osmosis is in the range of 85 to 95% for various osmotic sink solutions. The osmotic water flux is observed to be lower than the hydraulic water flux under reverse osmosis conditions. While the solute separation increases with an increase in annealing temperature, water flux decreases for both osmosis and reverse osmosis systems for various feed salinities. The effect of concentration polarization is analysed, and the effect of feed and osmotic sink velocity on the performance of the osmotic concentrator has also been studied. (orig.)

Platelet concentrates: Bioengineering dentistry′s regenerative dreams

Directory of Open Access Journals (Sweden)

Sushma Naag

2015-01-01

Full Text Available Technological advances in the fields of medicine and allied sciences had given much needed momentum into the field of molecular biology and regenerative medicine. They indeed provided a boost to innovate new yields for both hard tissue and soft tissue regeneration in dentistry. One among them is the use of platelet concentrates (platelet rich plasma [PRP], platelet rich fibrin [PRF]. Autologous concentrate of blood platelets with a suspension of growth factors offers an enhanced healing of hard and soft tissues. It is an auxiliary benefit for an operator to be aware of platelet concentrates and its healing properties for delivering unsurpassed oral health care to patients. The current article outlines the principles, objectives and clinical insight to the regenerative potential of platelet concentrates in various fields of dentistry. The search words of the PubMed data base were PRF and other permutations of keywords such as "PRP dentistry", PRF dentistry, PRF regenerative dentistry.

Mechanisms of urine concentration and dilution (1961); Les mecanismes de concentration et de dilution de l'urine (1961)

Energy Technology Data Exchange (ETDEWEB)

Morel, F.; Guinnebault, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

This paper is devoted to the analysis of a problem in the field of renal physiology which has shown many new developments during the course of the last few years. The following are treated successively: a) the data obtained from measurements of free water clearance and their interpretation; b) the data provided by nephron morphology and the comparative anatomy of the kidney ; c) the data relative to the existence of an intrarenal osmotic gradient; d) the principle of concentration multiplication by a counter current technique; e) the present day theory of counter current concentration of urine, and f) the physiological check on dilution and concentration mechanisms in urine. Lastly, the advantages of the modern theory and the unknown factors which remain are discussed. (authors) [French] Cette revue de question est consacree l'analyse d'un probleme de physiologie renale qui, au cours des dernieres annees, a subi un developpement et un renouveau remarquables. Sont successivement exposes: a) les donnees fournies par les mesures de clearance de l'eau libre et leur interpretation; b) les donnees fournies par la morphologie des nephrons et l'anatomie comparee du rein; c) les donnees concernant l'existence d'un gradient osmotique intrarenal; d) le principe de multiplication de concentration par contrecourant; e) la theorie actuelle de concentration de l'urine par contre-courant, et f) le controle physiologique des mecanismes de dilution et de concentration de l'urine. Les avantages de la theorie moderne et les obscurites qui subsistent sont enfin discutes. (auteurs)

Effect of fresh air ventilation on indoor radon concentration

International Nuclear Information System (INIS)

Sun Hao; Wu Jianhua; Fu Shi

2012-01-01

The radon concentration of laboratory for radon simulation (LRS) was measured by the RAD7 radon monitor, and the effect of the different fresh air ventilations on indoor radon concentration was studied and analyzed. The indoor radon concentration of LRS can be accumulated up to 2000 Bq/m 3 and the average radon exhalation rate of the LRS is 14.5 Bq · m -2 . h -1 . Furthermore, when the fresh air enters into the LRS continuously, the indoor radon concentration decreases exponentially with the increase of time. The equilibrium radon concentration and equilibrium time of LRS decrease exponentially with the increase of the rate of fresh air ventilation. In addition, the indoor radon concentration increases by accumulation with the decrease of the rate of fresh air ventilation. (authors)

Nonimaging fresnel lenses. Design and performance of solar concentrators

Energy Technology Data Exchange (ETDEWEB)

Leutz, R. [Tokyo Univ. of Agriculture and Technology, Koganei-shi (Japan). BASE; Suzuki, A. [UNESCO, Paris (France). Natural Science Sector

2001-07-01

This book offers a detailed and comprehensive account of the engineering of the world's first nonimaging Fresnel lens solar concentrator. The book closes a gap in solar concentrator design, and describes nonimaging refractive optics and its numerical mathematics. The contents follow a systems approach that is absent in standard handbooks of optics or solar energy. The reader is introduced to the principles, theories, and advantages of nonimaging optics from the standpoint of concentrating sunlight (the solar concentrator idea). The book shows the reader how to find his or her own optical solution using the rules and methodologies covering the design and the assessment of the nonimaging lens. This novel solar concentrator is developed within the natural constraints presented by the sun and in relation to competitive solutions offered by other concentrators. (orig.)

Varying hemin concentrations affect Porphyromonas gingivalis strains differently.

Science.gov (United States)

Ohya, Manabu; Cueno, Marni E; Tamura, Muneaki; Ochiai, Kuniyasu

2016-05-01

Porphyromonas gingivalis requires heme to grow, however, heme availability and concentration in the periodontal pockets vary. Fluctuations in heme concentration may affect each P. gingivalis strain differently, however, this was never fully demonstrated. Here, we elucidated the effects of varying hemin concentrations in representative P. gingivalis strains. Throughout this study, representative P. gingivalis strains [FDC381 (type I), MPWIb-01 (type Ib), TDC60 (type II), ATCC49417 (type III), W83 (type IV), and HNA99 (type V)] were used and grown for 24 h in growth media under varying hemin concentrations (5 × , 1 × , 0.5 × , 0.1 × ). Samples were lysed and protein standardized. Arg-gingipain (Rgp), H2O2, and superoxide dismutase (SOD) levels were subsequently measured. We focused our study on 24 h-grown strains which excluded MPWIb-01 and HNA99. Rgp activity among the 4 remaining strains varied with Rgp peaking at: 1 × for FDC381, 5 × for TDC60, 0.5 × for ATCC49417, 5 × and 0.5 × for W83. With regards to H2O2 and SOD amounts: FDC381 had similar H2O2 amounts in all hemin concentrations while SOD levels varied; TDC60 had the lowest H2O2 amount at 1 × while SOD levels became higher in relation to hemin concentration; ATCC49417 also had similar H2O2 amounts in all hemin concentrations while SOD levels were higher at 1 × and 0.5 × ; and W83 had statistically similar H2O2 and SOD amounts regardless of hemin concentration. Our results show that variations in hemin concentration affect each P. gingivalis strain differently. Published by Elsevier Ltd.

Starch source in high concentrate rations does not affect rumen pH, histamine and lipopolysaccharide concentrations in dairy cows

NARCIS (Netherlands)

Pilachai, R.; Schonewille, J.T.; Thamrongyoswittayakul, C.; Aiumlamai, S.; Wachirapakom, C.; Everts, H.; Hendriks, W.H.

2012-01-01

The replacement of ground corn by cassava meal on rumen pH, lipopolysaccharide (LPS) and histamine concentrations under typical Thai feeding conditions (high concentrate diets and rice straw as the sole source of roughage) was investigated. Four rumen-fistulated crossbred Holstein, non-pregnant, dry

Influence of bleaching on flavor of 34% whey protein concentrate and residual benzoic acid concentration in dried whey products

Science.gov (United States)

Previous studies have shown that bleaching negatively affects the flavor of 70% whey protein concentrate (WPC70), but bleaching effects on lower-protein products have not been established. Benzoyl peroxide (BP), a whey bleaching agent, degrades to benzoic acid (BA) and may elevate BA concentrations...

Is lowering reducing sugars concentration in French fries an effective measure to reduce acrylamide concentration in food service establishments?

NARCIS (Netherlands)

Sanny, M.A.I.; Jinap, S.; Bakker, E.J.; Boekel, van M.A.J.S.; Luning, P.A.

2012-01-01

The objective of this study was to obtain insight into the actual effectiveness of lowering reducing sugars concentration in par-fried potato strips on the concentration and variation of acrylamide in French fries prepared in real-life situations in food service establishments. Acrylamide, frying

Influence of Bleaching on Flavor of 34% Whey Protein Concentrate and Residual Benzoic Acid Concentration in Dried Whey Proteins

Science.gov (United States)

Previous studies have shown that bleaching negatively affects the flavor of 70% whey protein concentrate (WPC70), but bleaching effects on lower-protein products have not been established. Benzoyl peroxide (BP), a whey bleaching agent, degrades to benzoic acid (BA) and may elevate BA concentrations...

Brief Communication: Comparison of formol-acetone concentration ...

African Journals Online (AJOL)

Background: Formol-ether concentration technique is taken as a gold standard method to detect most intestinal parasites; however, because of its low safety and hazardous impact a need for better technique has a paramount importance. Objective: To evaluate a formol- acetone concentration method in comparison with the ...

Concentration control in an isotope separation plant; Regulation des concentrations dans une usine de separation isotopique

Energy Technology Data Exchange (ETDEWEB)

Jacques, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1962-07-01

Concentration control is examined for the case of a gaseous diffusion plant for uranium isotope separation. The effects of various typical perturbations are described and adequate systems of corrective actions are determined according to selected criteria. (author) [French] On considere une installation de separation des isotopes de l'uranium par diffusion gazeuse. On etudie les effets sur les concentrations isotopiques de diverses perturbations type donnees a l'avance et on determine le systeme d'actions correctives qui permet de reduire ces effets d'apres un critere d'efficacite donne. (auteur)

Wafer integrated micro-scale concentrating photovoltaics

Science.gov (United States)

Gu, Tian; Li, Duanhui; Li, Lan; Jared, Bradley; Keeler, Gordon; Miller, Bill; Sweatt, William; Paap, Scott; Saavedra, Michael; Das, Ujjwal; Hegedus, Steve; Tauke-Pedretti, Anna; Hu, Juejun

2017-09-01

Recent development of a novel micro-scale PV/CPV technology is presented. The Wafer Integrated Micro-scale PV approach (WPV) seamlessly integrates multijunction micro-cells with a multi-functional silicon platform that provides optical micro-concentration, hybrid photovoltaic, and mechanical micro-assembly. The wafer-embedded micro-concentrating elements is shown to considerably improve the concentration-acceptance-angle product, potentially leading to dramatically reduced module materials and fabrication costs, sufficient angular tolerance for low-cost trackers, and an ultra-compact optical architecture, which makes the WPV module compatible with commercial flat panel infrastructures. The PV/CPV hybrid architecture further allows the collection of both direct and diffuse sunlight, thus extending the geographic and market domains for cost-effective PV system deployment. The WPV approach can potentially benefits from both the high performance of multijunction cells and the low cost of flat plate Si PV systems.

Co-location synergies : specialized versus diverse logistics concentration areas

OpenAIRE

Heuvel, van den, F.P.; Langen, de, P.W.; Donselaar, van, K.H.; Fransoo, J.C.

2012-01-01

Purpose: The purpose of this paper is to contribute to the understanding of spatial concentration of logistics firms by empirically analyzing synergies through co-location and investigating whether co-location of logistics establishments in specialized logistics concentration areas results in benefits compared to co-location in diverse logistics concentration areas. Methodology: A survey among managers of 128 logistics establishments located in logistics concentration areas was used to test f...

Measurement of concentration of heavy water

International Nuclear Information System (INIS)

Tsukamoto, Yuichi; Kondo, Mitsuo; Sakurai, Naoyuki

1979-01-01

The concentration of heavy water is measured as one of the technical management in the Fugen plant. The heavy water is used as the moderator in the reactor. The measuring method depends on the theory of light absorption. The light absorption range of heavy water spreads from near infrared to infrared zone. The near infrared absorption was adopted for the purpose, as the absorption is much larger in infrared zone, and the measurement has to be conducted, limiting the apparent absorption. This measuring method is available to determine the concentration of heavy water in the broad range exactly. The preparation of heavy water sample and the measurement of the absorption spectra of near infrared ray are explained, as the experimental procedure. The sample cell was made of quartz, and the spectroscope was the Hitachi 323 type. The resolving power is 100 nm and 27 nm for the wave length of 1000 nm and 2500 nm, respectively. Concerning the measured results, the absorption was recorded in the wave length range from 600 nm to 2600 nm, and for the heavy water concentration range from 0 to 99.77 wt. %. The peaks of absorption were located at the wave length of 1450, 1660, 1920, 1970, 2020 and 2600 nm. The three kinds of fundamental vibration mode of the molecules of both light and heavy water are shown, and the peaks belong to H 2 O, HDO and D 2 O, respectively. The relation between the absorption and the heavy water concentration, and that between the transmissivity and the wave length are shown, when the cell thickness was varied to 5 mm and 20 mm, and the heavy water concentration to 21%, 62% and 99.85%. (Nakai, Y.)

Concentrating Solar Power. Report April 2009

Energy Technology Data Exchange (ETDEWEB)

Pihl, Erik (Chalmers Univ. of Technology, Enery and Environment, Goeteborg (Sweden))

2009-04-15

Concentrating solar power (CSP) technologies offer ways to utilise solar radiation by concentrating the light. In a concentrated form, the light can be utilised more cost efficiently. It is focused with mirrors or lenses and used either as a heat source in thermal power cycles (thermal CSP) or as a light source for high efficiency photovoltaic cells (concentrating photovoltaics, CPV). All concentrating systems use tracking to follow the movement of the sun, in two or three dimensions, and require direct sunlight (no diffusing clouds). CSP plants are often more complex, component wise than those based on flat PV. The extra cost of complexity is generally more than offset by the larger scales, the less need for expensive materials such as purified silicon and a better fit with the current energy infrastructure. Some thermal CSP plants offer great possibilities to deal with the intermittency of solar energy, as the heat generated can be stored in the form of a heated liquid in large tanks for many hours with little additional cost, and drive the thermal power generation also during cloudy periods or at night. CSP is growing rapidly and can be an important portion of future low-carbon energy systems. A prerequisite is that expected cost reductions are, at least largely, realised. In regions with good solar conditions (Mediterranean countries, US Southwest, Middle East, Australia etc), CSP systems already in the short-term future can satisfy significant shares of the power demand, to decrease CO{sub 2} emissions. Less solar-intensive regions (Northern Europe, much of North America etc) can be supplied with CSP power from solar-rich regions by using long distance power grids, for instance the high voltage DC cables being deployed and developed today

Radioimmunoassay of thyrotropin concentrated from serum

International Nuclear Information System (INIS)

Nisula, B.C.; Louvet, J.P.

1978-01-01

A method for concentrating human TSH (hTSH) from serum for use in RIAs is described. The method takes advantage of the affinity of the plant lectin, concanavalin A, for the carbohydrate portion of the hTSH molecule. The hTSH from 2.5 ml serum was adsorbed to concanavalin A covalently linked to sepharose and then radioimmunoassayed using the hTSH antiserum and hTSH for iodination distributed by the National Pituitary Agency. For the RIA standard curve, the hTSH reference preparation was concentrated from a serum wwith undetectable hTSH in order to correct for recovery and to control for nonspecific effects. The percentage of serum hTSH extracted from 2.5 ml serum with the concentration procedure was 76.6 +- 3.4% (mean +- SD). The coefficient of correlation between serum hTSH, determined with the concentration procedure, and serum hTSH determined without was 0.979 (P < 0.001). Over 95% of normal adult men and women had detectable levels of serum hTSH, ranging from < 0.56 to 4.0 μU/ml. The mean of detectable serum hTSH levels in normal adult women (n = 11) was 1.54 +- 1.03 μU/ml (mean +- SD) and in normal men (n = 9) was 2.02 +- 1.15 μU/ml (mean +- SD). Clinically hyperthyroid patients with diffuse and nodular toxic goiters (n = 8) and patients with hypothyroidism secondary to pituitary disease (n = 6), four of whom were taking replacement doses of thyroid hormone, had undetectable serum hTSH levels. Serum hTSH in patients with primary hypothyroidism uniformly exceeded the normal range. This hTSH concentrating procedure enhances the effective sensitivity and, therefore, the clinical utility of the RIA for hTSH in serum

Effect of hemodialysis on leflunomide plasma concentrations.

Science.gov (United States)

Beaman, Jasmine M; Hackett, L Peter; Luxton, Grant; Illett, Kenneth F

2002-01-01

To report on the influence of hemodialysis on the disposition of leflunomide in a woman with end-stage renal disease. A 65-year-old white woman with a history of diabetes, end-stage renal disease, rheumatoid arthritis, vasculitis, and leg ulcers was admitted to the hospital with a flare in the symptoms of joint pain and vasculitis. Prior to admission, she had been treated for rheumatoid arthritis with methotrexate 7.5 mg once a week. Due to adverse effects from methotrexate and continuing painful joints, leflunomide was considered as a therapeutic alternative. A loading dose of 100 mg was followed two days later by a daily dose of 10 mg. The active metabolite of leflunomide (A771726) was measured before and after hemodialysis and between hemodialysis sessions over a period of 80 days. Pre- and post-hemodialysis concentrations were compared for 17 sessions during this time. Based on the initial measured concentrations, the leflunomide dose was increased to 20 mg/d for several weeks before being reduced to 15 mg due to elevated liver enzymes. Although renal pathways are responsible in part for excretion of A771726, the concentrations achieved in this patient at doses of 10-20 mg/d were at the low end of the range reported in the literature. It was shown that pre- and post-hemodialysis concentrations of A771726 did not differ significantly. Thus, the low concentrations of A771726 were not a result of the hemodialysis. Steady-state concentrations of A771726 in plasma were not affected by hemodialysis or renal impairment. Reduction of the dose of leflunomide in patients with chronic renal failure undergoing hemodialysis does not appear to be required.

Nonlinear concentration gradients regulated by the width of channels for observation of half maximal inhibitory concentration (IC50) of transporter proteins.

Science.gov (United States)

Abe, Yuta; Kamiya, Koki; Osaki, Toshihisa; Sasaki, Hirotaka; Kawano, Ryuji; Miki, Norihisa; Takeuchi, Shoji

2015-08-21

This paper describes a simple microfluidic device that can generate nonlinear concentration gradients. We changed the "width" of channels that can drastically shorten the total microfluidic channel length and simplify the microfluidic network design rather than the "length" of channels. The logarithmic concentration gradients generated by the device were in good agreement with those obtained by simulation. Using this device, we evaluated a probable IC50 value of the ABC transporter proteins by the competitive transport assays at five different logarithmic concentrations. This probable IC50 value was in good agreement with an IC50 value (0.92 μM) obtained at the diluted concentrations of seven points.

Detecting microalbuminuria by urinary albumin/creatinine concentration ratio

DEFF Research Database (Denmark)

Jensen, J S; Clausen, P; Borch-Johnsen, K

1997-01-01

BACKGROUND: Microalbuminuria, i.e. a subclinical increase of the albumin excretion rate in urine, may be a novel atherosclerotic risk factor. This study aimed to test whether microalbuminuria can be identified by measurement of urinary albumin concentration or urinary albumin/creatinine concentra......BACKGROUND: Microalbuminuria, i.e. a subclinical increase of the albumin excretion rate in urine, may be a novel atherosclerotic risk factor. This study aimed to test whether microalbuminuria can be identified by measurement of urinary albumin concentration or urinary albumin/creatinine...... not included. Urinary albumin (Ualb) and creatinine (Ucreat) concentrations were measured in an overnight collected sample by enzyme-linked immunosorbent and colorimetric assays, respectively. Urinary albumin excretion rate (UAER) and urinary albumin/creatinine concentration ratio (Ualb/Ucreat) were calculated......, and 73%, 97%, and 73% for Ualb/Ucreat, respectively. CONCLUSIONS: It is concluded that measurement of the albumin/creatinine concentration ratio is a specific and quite sensitive alternative to measurement of the urinary albumin excretion rate in timed collections, when screening for microalbuminuria....

Policy and Concentration of Activities : The Case of Dutch Nanotechnology

NARCIS (Netherlands)

Cunningham, S.; Werker, C.

2012-01-01

Geographical concentration of economic activities has been widely discussed. However, the insights into other kinds of concentration such as technological and organizational concentration have been scarce. Here, we analyze organizational, technological and geographical concentration of

Lithography-free nanofluidic concentrator based on droplets-on-demand system

Science.gov (United States)

Yu, Miao; Zhou, Hongbo; Yao, Shuhuai

2013-11-01

Biomarkers are usually low-abundance proteins in biofluids and below detection limit of conventional biosensors. Nanofluidic concentration devices allow efficient biomolecules trapping by utilizing ion concentration polarization near nanochannels. However, once the electric field is turned off, the electrokinetic concentration plug cannot maintain its concentration status and starts to diffuse. In order to maintain the high concentration and extract the concentrated sample for further analysis, a good approach is to encapsulate these plugs into water-in-oil droplets. Here we developed a nanofluidic concentrator based on droplet-on-demand generator to encapsulate concentrated sample in nL droplets. The lithography-free nanochannels were patterned by thermal cracking on the surface of PS Petri-dish. The resulting nanochannel arrays were 30 nm in depth. In combination with microchannels on PDMS, the micro-nano hybrid chip was developed. We used FITC solution to demonstrate that the chip significantly increased the sample concentration for more than 100 folds within 5 minutes. By tuning the pulsed pressure imposed by the solenoid valve connected to the concentration channel, the system can generate a desired volume of droplet with a target sample concentration at a prescribed time. This work was supported by the Research Grants Council of Hong Kong under General Research Fund (Grant No. 621110).

Be-7 concentration in garden and wild vegetables in Japan

International Nuclear Information System (INIS)

Nobuhiko Ito; Iwao Kunugijama; Yoshinori Furukawa.

1996-01-01

Beryllium-7 is a natural radionuclide produced by cosmic rays. Be-7 is found vividly in the atmosphere, so the concentrations in airborne particles were analyzed by many investigators. It is known that airborne particles with Be-7 in the atmosphere fall slowly to the ground and adhere to plant surface. However, Be-7 concentrations of foods were not measured too much. So we measured Be-7 concentrations of garden vegetables, wild vegetables, grasses, beef and milk, and calculated internal exposure dose from Be-7. Beryllium-7 concentrations of plant samples are shown. Beryllium-7 concentrations of garden vegetables were from 0.2 to 25.3 Bq/kg, and concentrations of wild vegetables were from 0.8 to 23.5 Bq/kg. There is no difference in Be-7 concentrations between garden vegetables and wild vegetables. Leaf vegetables have almost higher concentration of Be-7. Though Matteuccia Struthiopteris and Pteridium aquilinum are ferns, their eatable stages are sprouts. The relationship between surface area and Be-7 concentration in some vegetable leaves gathered simultaneously at the same farm is shown. Beryllium-7 concentrations of leaves correlate significantly with the surface area/weight ratios. What high concentration vegetables have proportionately broad leaves suggests that atmospheric Be-7 particles adhere to surface of leaves. (author)

Determination of Glucose Concentration in Yeast Culture Medium

Science.gov (United States)

Hara, Seiichi; Kishimoto, Tomokazu; Muraji, Masafumi; Tsujimoto, Hiroaki; Azuma, Masayuki; Ooshima, Hiroshi

The present paper describes a sensor for measuring the glucose concentration of yeast culture medium. The sensor determines glucose concentration by measuring the yield of hydrogen peroxide produced by glucose oxidase, which is monitored as luminescence using photomultiplier. The present sensor is able to measure low glucose concentration in media in which yeast cells keep respiration state. We herein describe the system and the characteristics of the glucose sensor.

Mercury Concentrations of Bluegill (Lepomis macrochirus Vary by Sex

Directory of Open Access Journals (Sweden)

Charles P. Madenjian

2015-11-01

Full Text Available Patterns in relative differences in contaminant concentrations between the sexes across many species of fish may reveal clues for important behavioral and physiological differences between the sexes, and may also be useful in developing fish consumption advisories and efficient designs for programs meant to monitor contaminant levels in fish. We determined skin-off fillet and whole-fish total mercury (Hg concentrations of 28 adult female and 26 adult male bluegills (Lepomis macrochirus from Squaw Lake, Oakland County, Michigan (MI, USA. Bioenergetics modeling was used to quantify the effect of growth dilution on the difference in Hg concentrations between the sexes. On average, skin-off fillet and whole-fish Hg concentrations were 25.4% higher and 26.6% higher, respectively, in females compared with males. Thus, the relative difference in Hg concentrations between the sexes for skin-off fillets was nearly identical to that for whole fish. However, mean skin-off fillet Hg concentration (363 ng/g was 2.3 times greater than mean whole-fish Hg concentration (155 ng/g. Males grew substantially faster than females, and bioenergetics modeling results indicated that the growth dilution effect could account for females having 14.4% higher Hg concentrations than males. Our findings should be useful in revising fish consumption advisories.

Aspects of reduction clorination of pyrochlore concentrates

International Nuclear Information System (INIS)

Gameiro, D.H.; Brocchi, E.A.

1985-01-01

Reduction chlorination experiments were carried out with two different Brazilian pyrochlore concentrates in order to evaluate the effects of some variables on the extent of niobium pentoxide gaseification as well as to compare the behavior of concentrate under the same chlorination conditions. The pyrochlore concentrates from Araxa (MG) and Catalao (GO), Brazil, were submitted to X ray diffraction and X ray fluorescence analysis for determining their chemical compositions. Kinetic curves were obtained with the main variables being temperature and percentage of reducing agent. Analysis of the condensed material in terms of Nb 2 O 5 indicated that chlorination can be used to produce niobium pentoxide. (Author) [pt

Body and Gender in Nazi Concentration Camps

Directory of Open Access Journals (Sweden)

Bożena Karwowska

2009-01-01

Full Text Available The article Body and Gender in Nazi Concentration Camps is an attempt to discuss difficult issues of human sexuality and sexually marked behaviors in the context of the concentration camps, and their descriptions in the memoirs of the survivors. Using notions and concepts of the so called "black American feminism" the author (referring extensively to books by Stanisław Grzesiuk and Zofia Romanowiczowa shows how in the concentration camp the human body became the only space of a relative privacy of the prisoner. At the same time the body becomes a territory on which all - both biological and socially constructed - human fates cross.

Case study of elevated layers of high sulfate concentration

International Nuclear Information System (INIS)

McNaughton, D.J.; Orgill, M.M.

1979-01-01

During studies in August 1976 that were part of the Multi-State Atmospheric Power Production Pollutant Study (MAP3S), Alkezweeny et al., (1977) noted that in the Milwaukee urban plume, layers of relatively high sulfate concentrations occurred at high altitudes with respect to the boundary layer. This paper represents a progress report on studies undertaken to investigate possible causes for a bimodel vertical profile of sulfate concentrations. Data presented by Alkezweeny et al., (1977) serve as a basis for this study. Data from August 23, 1976, and August 24, 1978, indicate concentrations relatively high in sulfate, at 1000 and 6000 ft, respectively, with lower concentrations at lower altitudes. Concentrations of trace metals also indicate no peaks in the vertical concentration profiles above the surface. Initial studies of the high, elevated sulfate concentrations have centered on the August 23 measurements taken over southeast Wisconsin using synoptic data from the national weather service, emissions data from the national emissions data bank system (EPA), air quality data from the national air surveillance network (EPA), and satellite photographs from the EROS Data Center

Atmospheric radon daughters concentration inside and outside of cloud

International Nuclear Information System (INIS)

Nishikawa, Tsuguo; Okabe, Shigeru; Aoki, Masayoshi; Imamura, Takakazu; Iwata, Yoshitomo; Tamura, Yukihide; Tsuboguchi, Masayasu

1987-01-01

The measurements of the atmospheric radon daughters concentration in and out of the cloud were carried out on the top of the mountain, and in the upper air of the sea by using the airplane. The difference of the concentrations between inside and outside of the stratus measured on the top of the mountain was not clear. The atmospheric radon daughters concentration at the top of the mountain decreased when the amount of precipitation at that point was large. Concerning the cumulus investigated by using the airplane, the concentration in the cloud was a little higher than the concentration out of the cloud. Results of the measurements show that the cloud seems to be constructed of the various air masses whose radon daughters concentrations are different from each other even though it appears to be uniform. (author)

Genome-wide association study of serum selenium concentrations

DEFF Research Database (Denmark)

Gong, Jian; Hsu, Li; Harrison, Tabitha