Detrital K-feldspar thermochronology of the Nanaimo Group: Characterization of Basement and Extraregional Basin Contributions

Science.gov (United States)

Isava, V.; Grove, M.; Mahoney, J. B.; Kimbrough, D. L.

2016-12-01

The Late Cretaceous-Early Paleogene Nanaimo Group covers the contact between Triassic basement Wrangellia terrane and the Jurassic-Cretaceous Coast Plutonic Complex (CPC) in southern British Columbia. Prior detrital zircon U-Pb and Hf studies indicate a change in sediment source for the Nanaimo basin, from the primitive CPC in Santonian-Early Campanian time to an isotopically evolved continental extraregional source during the late Campanian/Maastrictian. Two notably different areas have been proposed as potential source regions: (1) the Idaho/Boulder batholith and Belt Supergroup, and (2) the Mojave/Salinia segment of structurally disrupted late Cretaceous southern California margin. Single crystal 40Ar/39Ar laser fusion of ca. 100-200 grains apiece from seven detrital K-feldspar samples from Santonian-Maastrichtian strata of the northern Nanaimo Group constrain the history of the sediments' source regions. The two oldest samples, from the K-feldspar poor Comox and Extension Fms., display a monotonic increasing distribution of cooling ages 80-125 Ma that reflects shallow erosion of the CPC. In contrast, Late Campanian strata of the Cedar District and De Courcy Fms. exhibit a more pronounced cluster of cooling ages 80-95 Ma as well as a greater proportion of Jurassic ages that represent progressively deeper erosion of the CPC. Evidence for an extraregional sediment source appears abruptly in the Geoffrey Fm. by 72 Ma, matching the time of local-to-extraregional shift indicated in detrital zircon U-Pb studies. Over 90% of the detrital K-feldspars from these arkosic sandstones yield cooling ages of 70-80 Ma, with sparse older ages associated with the CPC. Samples from the successively younger Spray and Gabriola Fms. also yield >90% K-feldspar ages younger than 80 Ma and exhibit age maxima of 68 Ma and 65 Ma, respectively. These results are distinct from detrital zircon U-Pb and K-feldspar 40Ar/39Ar ages of the southern Sierra Nevada, Mojave/Salina, and northern

Correlation of basic TL, OSL and IRSL properties of ten K-feldspar samples of various origins

Energy Technology Data Exchange (ETDEWEB)

Sfampa, I.K. [Aristotle University of Thessaloniki, Nuclear Physics Laboratory, 54124 Thessaloniki (Greece); Polymeris, G.S. [Institute of Nuclear Sciences, Ankara University, 06100 Besevler, Ankara (Turkey); Pagonis, V. [McDaniel College, Physics Department, Westminster, MD 21157 (United States); Theodosoglou, E. [Department of Mineralogy-Petrology-Economic Geology, School of Geology, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Tsirliganis, N.C. [Laboratory of Radiation Applications and Archaeological Dating, Department of Archaeometry and Physicochemical Measurements, ‘Athena’ R.& I.C., Kimmeria University Campus, GR67100 Xanthi (Greece); Kitis, G., E-mail: gkitis@auth.gr [Aristotle University of Thessaloniki, Nuclear Physics Laboratory, 54124 Thessaloniki (Greece)

2015-09-15

Highlights: • OSL and IRSL bleaching behavior of ten K-feldspar samples is presented. • OSL and IRSL decay curves were component resolved using tunneling model. • The growth of integrated OSL and IRSL signals versus time was described by new expression based on tunneling model. • Correlation between TL, OSL and IRSL signals and of all properties with K-feldspar structure was discussed. - Abstract: Feldspars stand among the most widely used minerals in dosimetric methods of dating using thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Having very good dosimetric properties, they can in principle contribute to the dating of every site of archaeological and geological interest. The present work studies basic properties of ten naturally occurring K-feldspar samples belonging to three feldspar species, namely sanidine, orthoclase and microcline. The basic properties studied are (a) the influence of blue light and infrared stimulation on the thermoluminescence glow-curves, (b) the growth of OSL, IRSL, residual TL and TL-loss as a function of OSL and IRSL bleaching time and (c) the correlation between the OSL and IRSL signals and the energy levels responsible for the TL glow-curve. All experimental data were fitted using analytical expressions derived from a recently developed tunneling recombination model. The results show that the analytical expressions provide excellent fits to all experimental results, thus verifying the tunneling recombination mechanism in these materials and providing valuable information about the concentrations of luminescence centers.

Geochemimal aspects of the megacryst suite from the Monastery Kimberlite pipe

International Nuclear Information System (INIS)

Jakob, W.R.O.

1977-08-01

The Monastery Kimberlite pipe, situated in the Marquard District, South Africa, has evoked much interest in kimberlite studies because it contains large single crystals of olivine, enstatite, garnet, ilmenite and phlogopite/vermiculite. All the silicates have been found associated with ilmenite. This study is concerned with the chemistry of the megacryst suite. These homogeneous crystals have large ranges in chemical composition. The silicates intergrown with ilmenite are always more iron-rich and poorer in chrome than the discrete megacrysts. The olivine megacrysts fall into two compositional ranges, with averages near Fo86 and Fo80. The more-magnesian olivines often have small inclusions of kimberlite with a composition similar to the main Quarry-Type Kimberlite from Monastery. The enstatite megacrysts fall into two compositionally different groups. Least abundant at Monastery are glassy, homogenuous enstatites which have large ranges in chemical composition. Coarse regular and irregular intergrowths of enstatite ilmenite have very restricted compositions which fall within the range defined by the homogenuous enstatites. These two types define Group I enstatites. The most abundant are the lamellar Group II enstatite, which re-equilibrated at lower temperatures and have exsolved chrome-diopside. These enstatites have variable Mg/Mg+Fe ratios, but otherwise have very restricted ranges in chemical composition, unlike the Group I enstatites. The diopside megacrysts are chrome-poor subcalcic diopsides with about 10 mole% iron. Diopside-ilmenite lamellar intergrowths have higher Ca/Ca+Mg ratios than the discrete diopsides. The discrete garnet megacrysts are chrome-poor high-titanium pyropes with peridotitic affinities. Rare finds of small garnet inclusions in ilmenite megacrysts are very low in chrome [af

Exchange of Na+ and K+ between water vapor and feldspar phases at high temperature and low vapor pressure

Science.gov (United States)

Fournier, R.O.

1976-01-01

In order to determine whether gas (steam) containing a small amount of dissolved alkali chloride is effective in promoting base exchange of Na+ and K+ among alkali feldspars and coexisting brine or brine plus solid salt, experiments were carried out at 400-700??C and steam densities ranging down to less than 0.05. For bulk compositions rich in potassium, the low pressure results are close to previous high-pressure results in composition of the fluid and coexisting solid phase. However, when the bulk composition is more sodic, alkali feldspars are relatively richer in potassium at low pressure than at high pressure. This behaviour corresponds to enrichment of potassium in the gas phase relative to coexisting brine and precipitation of solid NaCl when the brine plus gas composition becomes moderately sodic. The gas phase is very effective in promoting base exchange between coexisting alkali feldspars at high temperature and low water pressure. This suggests that those igneous rocks which contain coexisting alkali feldspars out of chemical equilibrium either remained very dry during the high-temperature part of their cooling history or that the pore fluid was a gas containing very little potassium relative to sodium. ?? 1976.

IRSL dating of K-feldspars: Modelling natural dose response curves to deal with anomalous fading and trap competition

International Nuclear Information System (INIS)

Kars, Romee H.; Wallinga, Jakob

2009-01-01

We recently proposed a model that reconstructs the natural dose response curve for K-rich feldspars, using laboratory fading measurements and dose response as input parameters. The model is based on the relationship between recombination centre density and trap lifetime. In this study we test the working of the model by comparing modelled feldspar ages with known quartz OSL ages of the same samples and with anomalous fading-corrected feldspar ages. The modelled feldspar ages are in good agreement with quartz OSL ages and corrected feldspar ages, opening possibilities for future use of the model on samples without independent age constraints. Furthermore, we investigate the effects of trap competition on the build-up of IRSL signal using two new variations of the model. Results show that incorporating trap competition into the model reduces the agreement between feldspar IRSL ages and quartz OSL ages.

Structural, K-Ar and 40Ar-39Ar age studies of adularia K-feldspars from the Lizard Complex, England

International Nuclear Information System (INIS)

Halliday, A.N.; Mitchell, J.G.

1976-01-01

Conventional K-Ar analyses of fifteen adularia feldspars from the Lizard Complex yield ages between 181+-2 Ma and 220+-3 Ma (with one exception from Holseer Cove yielding an age of 156+-3 Ma). The feldspars are dominantly monoclinic but most contain a minor but constant proportion of triclinic material with variable triclinicity. An inverse correlation exists between triclinicity and K-Ar age interpreted as representing argon loss related to the structural state. Extrapolation of the data to zero triclinicity indicates a true age of 210-220 Ma. 40 Ar- 39 Ar stepwise degassing analyses yield plateau ages related to the K-Ar ages and not the crystallization age. The results can be explained in terms of postcrystallization Al-Si ordering resulting in argon loss from lattice sites which under normal diffusion conditions requires a range of activation energies. The Holseer Cove sample is monoclinic and an 40 Ar- 39 Ar stepheating analysis suggests a later crystallization at 160-170 Ma. Neither primary crystallization nor spontaneous ordering through time explain the origin of the triclinic adularia. It is suggested that ordering has been induced by the passage of low-temperature alkaline solutions at a subsequent point in geological time. Argon loss by ordering could explain the low ages found using both K-Ar and 40 Ar- 39 Ar stepheating methods when applied to feldspars in general. The 210-220 Ma, and 160-170 Ma hydrothermal events affected much of southwest England and are probably related to major geotectonic movements in western Europe. (Auth.)

Principles of Thermal Expansion in Feldspars

Science.gov (United States)

Hovis, Guy; Medford, Aaron; Conlon, Maricate; Tether, Allison; Romanoski, Anthony

2010-05-01

Following the recent thermal expansion work of Hovis et al. (1) on AlSi3 feldspars, we have investigated the thermal expansion of plagioclase, Ba-K, and Ca-K feldspar crystalline solutions. X-ray powder diffraction data were collected between room temperature and 925 °C on six natural plagioclase specimens ranging in composition from anorthite to oligoclase, the K-exchanged equivalents of these plagioclase specimens, and five synthetic Ba-K feldspars with compositions ranging from 25 to 99 mol % BaAl2Si2O8. The resulting thermal expansion coefficients (α) for volume have been combined with earlier results for end-member Na- and K-feldspars (2,3). Unlike AlSi3 feldspars, Al2Si2 feldspars, including anorthite and celsian from the present study plus Sr- and Pb-feldspar from other workers (4,5), show essentially constant and very limited thermal expansion, regardless of divalent cation size. In the context of structures where the Lowenstein rule (6) requires Al and Si to alternate among tetrahedra, the proximity of bridging Al-O-Si oxygen ions to divalent neighbors (ranging from 0 to 2) produces short Ca-O (or Ba-O) bonds (7,8) that apparently are the result of local charge-balance requirements (9). Gibbs et al. (10) suggest that short bonds such as these have a partially covalent character. This in turn stiffens the structure. Thus, for feldspar series with coupled substitution the change away from a purely divalent M-site occupant gives the substituting (less strongly bonded) monovalent cations increasingly greater influence on thermal expansion. Overall, then, thermal expansion in the feldspar system is well represented on a plot of α against room-temperature volume, where one sees a quadrilateral bounded by data for (A) AlSi3 feldspars whose expansion behavior is controlled largely by the size of the monovalent alkali-site occupant, (B) Al2Si2 feldspars whose expansion is uniformly limited by partially-covalent bonds between divalent M-site occupants and

The Thermal Expansion Of Feldspars

Science.gov (United States)

Hovis, G. L.; Medford, A.; Conlon, M.

2009-12-01

Hovis and others (1) investigated the thermal expansion of natural and synthetic AlSi3 feldspars and demonstrated that the coefficient of thermal expansion (α) decreases significantly, and linearly, with increasing room-temperature volume (VRT). In all such feldspars, therefore, chemical expansion limits thermal expansion. The scope of this work now has been broadened to include plagioclase and Ba-K feldspar crystalline solutions. X-ray powder diffraction data have been collected between room temperature and 925 °C on six plagioclase specimens ranging in composition from anorthite to oligoclase. When combined with thermal expansion data for albite (2,3,4) a steep linear trend of α as a function of VRT emerges, reflecting how small changes in composition dramatically affect expansion behavior. The thermal expansion data for five synthetic Ba-K feldspars ranging in composition from 20 to 100 mole percent celsian, combined with data for pure K-feldspar (3,4), show α-VRT relationships similar in nature to the plagioclase series, but with a slope and intercept different from the latter. Taken as a group all Al2Si2 feldspars, including anorthite and celsian from the present study along with Sr- (5) and Pb-feldspar (6) from other workers, show very limited thermal expansion that, unlike AlSi3 feldspars, has little dependence on the divalent-ion (or M-) site occupant. This apparently is due to the necessitated alternation of Al and Si in the tetrahedral sites of these minerals (7), which in turn locks the tetrahedral framework and makes the M-site occupant nearly irrelevant to expansion behavior. Indeed, in feldspar series with coupled chemical substitution it is the change away from a 1:1 Al:Si ratio that gives feldspars greater freedom to expand. Overall, the relationships among α, chemical composition, and room-temperature volume provide useful predictive tools for estimating feldspar thermal expansion and give insight into the controls of expansion behavior in

Differential rates of feldspar weathering in granitic regoliths

Science.gov (United States)

White, A.F.; Bullen, T.D.; Schulz, M.S.; Blum, A.E.; Huntington, T.G.; Peters, N.E.

2001-01-01

Differential rates of plagioclase and K-feldspar weathering commonly observed in bedrock and soil environments are examined in terms of chemical kinetic and solubility controls and hydrologic permeability. For the Panola regolith, in the Georgia Piedmont Province of southeastern United States, petrographic observations, coupled with elemental balances and 87Sr/86Sr ratios, indicate that plagioclase is being converted to kaolinite at depths > 6 m in the granitic bedrock. K-feldspar remains pristine in the bedrock but subsequently weathers to kaolinite at the overlying saprolite. In contrast, both plagioclase and K-feldspar remain stable in granitic bedrocks elsewhere in Piedmont Province, such as Davis Run, Virginia, where feldspars weather concurrently in an overlying thick saprolite sequence. Kinetic rate constants, mineral surface areas, and secondary hydraulic conductivities are fitted to feldspar losses with depth in the Panola and Davis Run regoliths using a time-depth computer spreadsheet model. The primary hydraulic conductivities, describing the rates of meteoric water penetration into the pristine granites, are assumed to be equal to the propagation rates of weathering fronts, which, based on cosmogenic isotope dating, are 7 m/106 yr for the Panola regolith and 4 m/106 yr for the Davis Run regolith. Best fits in the calculations indicate that the kinetic rate constants for plagioclase in both regoliths are factors of two to three times faster than K-feldspar, which is in agreement with experimental findings. However, the range for plagioclase and K-feldspar rates (kr = 1.5 x 10-17 to 2.8 x 10-16 mol m-2 s-1) is three to four orders of magnitude lower than for that for experimental feldspar dissolution rates and are among the slowest yet recorded for natural feldspar weathering. Such slow rates are attributed to the relatively old geomorphic ages of the Panola and Davis Run regoliths, implying that mineral surface reactivity decreases significantly with

IR-RF dating of sand-sized K-feldspar extracts: A test of accuracy

DEFF Research Database (Denmark)

Buylaert, Jan-Pieter; Jain, Mayank; Murray, A.S.

2012-01-01

In this paper we use a recently developed radioluminescence (RL) attachment to the Risø TL/OSL reader to test the InfraRed-RadioFluorescence (IR-RF) dating method applied to K-feldspar rich extracts from our known-age archive samples. We present experiments to characterise the instrument performa......In this paper we use a recently developed radioluminescence (RL) attachment to the Risø TL/OSL reader to test the InfraRed-RadioFluorescence (IR-RF) dating method applied to K-feldspar rich extracts from our known-age archive samples. We present experiments to characterise the instrument...... performance and to test the reproducibility of IR-RF measurements. These experiments illustrate the high sensitivity and dose rate of our RL system, the negligible influence of the turntable movement on IR-RF signals and the effectiveness of the built in 395 nm LED at bleaching IR-RF signals. We measure IR......-RF ages on a set of samples with independent age control using a robust analytical method, which is able to detect any possible sensitivity change. Our IR-RF ages do not agree well with the independent age control; the ages of the younger samples (20–45 ka) are significantly over-estimated while the ages...

Infrared stimulated luminescence dating of an Eemian (MIS 5e) site in Denmark using K-feldspar

DEFF Research Database (Denmark)

Buylaert, Jan-Pieter; Huot, Sebastian; Murray, Andrew S.

2011-01-01

Infrared stimulated luminescence (IRSL) dating of K-feldspars may be an alternative to quartz optically stimulated luminescence (OSL) dating when the quartz OSL signal is too close to saturation or when the quartz luminescence characteristics are unsuitable. In this paper, Eemian (MIS 5e) coastal...

Salinity-Dependent Adhesion Response Properties of Aluminosilicate (K-Feldspar) Surfaces

DEFF Research Database (Denmark)

Lorenz, Bärbel; Ceccato, Marcel; Andersson, Martin Peter

2017-01-01

is composed predominantly of quartz with some clay, but feldspar grains are often also present. While the wettability of quartz and clay surfaces has been thoroughly investigated, little is known about the adhesion properties of feldspar. We explored the interaction of model oil compounds, molecules...... in well sorted sandstone. Adhesion forces, measured with the chemical force mapping (CFM) mode of atomic force microscopy (AFM), showed a low salinity effect on the fresh feldspar surfaces. Adhesion force, measured with -COO(H)-functionalized tips, was 60% lower in artificial low salinity seawater (LS......, ∼1500 ppm total dissolved solids) than in the high salinity solution, artificial seawater (HS, ASW, ∼35 600 ppm). Adhesion with the -CH3 tips was as much as 30% lower in LS than in HS. Density functional theory calculations indicated that the low salinity response resulted from expansion of the electric...

Crystallization history of enriched shergottites from Fe and Mg isotope fractionation in olivine megacrysts

Science.gov (United States)

Collinet, Max; Charlier, Bernard; Namur, Olivier; Oeser, Martin; Médard, Etienne; Weyer, Stefan

2017-06-01

Martian meteorites are the only samples available from the surface of Mars. Among them, olivine-phyric shergottites are basalts containing large zoned olivine crystals with highly magnesian cores (Fo 70-85) and rims richer in Fe (Fo 45-60). The Northwest Africa 1068 meteorite is one of the most primitive "enriched" shergottites (high initial 87Sr/86Sr and low initial ε143Nd). It contains olivine crystals as magnesian as Fo 77 and is a major source of information to constrain the composition of the parental melt, the composition and depth of the mantle source, and the cooling and crystallization history of one of the younger magmatic events on Mars (∼180 Ma). In this study, Fe-Mg isotope profiles analyzed in situ by femtosecond-laser ablation MC-ICP-MS are combined with compositional profiles of major and trace elements in olivine megacrysts. The cores of olivine megacrysts are enriched in light Fe isotopes (δ56FeIRMM-14 = -0.6 to -0.9‰) and heavy Mg isotopes (δ26MgDSM-3 = 0-0.2‰) relative to megacryst rims and to the bulk martian isotopic composition (δ56Fe = 0 ± 0.05‰, δ26Mg = -0.27 ± 0.04‰). The flat forsterite profiles of megacryst cores associated with anti-correlated fractionation of Fe-Mg isotopes indicate that these elements have been rehomogenized by diffusion at high temperature. We present a 1-D model of simultaneous diffusion and crystal growth that reproduces the observed element and isotope profiles. The simulation results suggest that the cooling rate during megacryst core crystallization was slow (43 ± 21 °C/year), and consistent with pooling in a deep crustal magma chamber. The megacryst rims then crystallized 1-2 orders of magnitude faster during magma transport toward the shallower site of final emplacement. Megacryst cores had a forsterite content 3.2 ± 1.5 mol% higher than their current composition and some were in equilibrium with the whole-rock composition of NWA 1068 (Fo 80 ± 1.5). NWA 1068 composition is thus close to a

Post-IR IRSL₂₉₀ dating of K-rich feldspar sand grains in a wind-dominated system on Sardinia

DEFF Research Database (Denmark)

Andreucci, S.; Sechi, D.; Buylaert, Jan-Pieter

2017-01-01

The reliability of a post-IR elevated temperature IRSL (290 °C; pIRIR290) is tested on wind-blown, sand-sized (180–250 μm) K-rich feldspar grains. The pIRIR290 ages were compared with quartz SAR-OSL data, other independent age controls and historical information. Three study areas along the coast....... The pIRIR290 ages indicate an offset up to ∼1000 years. We can conclude that the pIRIR290 method on sand-sized K-feldspar grains shows great promise for samples at or beyond the quartz OSL age limit but should not be applied to Late Holocene or modern deposits....

Investigations of the post-IR IRSL protocol applied to single K-feldspar grains from fluvial sediment samples

International Nuclear Information System (INIS)

Nian, Xiaomei; Bailey, Richard M.; Zhou, Liping

2012-01-01

The post-IR IRSL protocol with single K-feldspar grains was applied to three samples taken from a fluvial sedimentary sequence at the archaeological site of the Dali Man, Shaanxi Province, China. K-feldspar coarse grains were extracted for measurement. Approximately 30–40% of the grains were sufficiently bright to measure, and after application of rejection criteria based on signal strength, recuperation, recycling ratio and saturation dose, ∼10–15% of the grains were used for D e calculation. The relationship of signal decay rate and form of D e (t) with the recovery dose were investigated. The dose recovery ratios of the samples after initial bleaching with the four different light sources were within uncertainties of unity. No anomalous fading was observed. The over-dispersion of the recovered dose and D e values were similar, suggesting neither incomplete resetting of the post-IR IRSL signals nor spatially heterogeneous dose rates significantly affected the natural dose estimates. The values of D e obtained with the single K-feldspar grain post-IR IRSL protocol were in the range ∼400–490 Gy. Combining all of the measured single-grain signals for each of the individual samples (into a ‘synthetic single aliquot’) increased the D e estimates to the range ∼700–900 Gy, suggesting that the grains screened-out by the rejection criteria may have the potential to cause palaeodose over-estimation, although this finding requires a more extensive investigation. Thermally transferred signals were found in the single K-feldspar grains post-IR IRSL protocol, and the proportion of thermally transferred signal to test-dose OSL signal (stimulation at 290 °C) from the natural dose was higher than from regenerative doses, and the proportion was grain- and dose-dependent. As such, TT-post-IR IRSL signals at 290 °C have the potential to cause dose underestimation, although this may be reduced by using larger test-dose irradiations. Our study demonstrates

Coeval Formation of Zircon Megacrysts and Host Magmas in the Eifel Volcanic Field (Germany) Based on High Spatial Resolution Petrochronology

Science.gov (United States)

Schmitt, Axel; Klitzke, Malte; Gerdes, Axel; Ludwig, Thomas; Schäfer, Christof

2017-04-01

Zircon megacrysts (approx. 0.5-6 mm in diameter) from the Quaternary West and East Eifel volcanic fields, Germany, occur as euhedral crystals in porous K-spar rich plutonic ejecta clasts, and as partially resorbed xenocrysts in tephrite lava. Their relation to the host volcanic rocks has remained contentious because the dominantly basanitic to phonolitic magma compositions in the Eifel are typically zircon undersaturated. We carried out a detailed microanalytical study of zircon megacrysts from seven locations (Emmelberg and Rockeskyll in the West Eifel; Bellerberg, Laacher See, Mendig, Rieden, and Wehr in the East Eifel). Crystals were embedded in epoxy, sectioned to expose interiors through grinding with abrasives, diamond-polished, and mapped by optical microscopy, backscattered electron, and cathodoluminescence imaging. Subsequently, isotope-specific analysis using secondary ionization mass spectrometry (SIMS) and laser ablation inductively coupled mass spectrometry (LA-ICP-MS) was carried out placing 100 correlated spots on 20 selected crystals. Concordant U-Th disequilibrium and U-Pb ages determined by SIMS are between ca. 430 ka (Rieden) and 170 ka (Mendig) and indicate that the megacryst zircons crystallized almost always briefly before eruption. A significant gap between zircon megacryst crystallization (ca. 230 ka) and eruption (ca. 45 ka) ages was only detected for the Emmelberg location. SIMS trace element abundances (e.g., rare earth elements) vary by orders-of-magnitude and correlate with domain boundaries visible in cathodoluminescence; trace element patterns match those reported for zircon from syenitic origins. Isotopic compositions are homogeneous within individual crystals, but show some heterogeneity between different crystals from the same locality. Average isotopic values (δ18O SMOW = +5.3±0.6 ‰ by SIMS; present-day ɛHf = +1.7±2.5 ‰ by LA-ICP-MS; 1 standard deviation), however, are consistent with source magmas being dominantly mantle

Natural radioactivity and Rare Earth elements in feldspar samples, Central Eastern desert, Egypt

International Nuclear Information System (INIS)

Walley El-Dine, Nadia; El-Shershaby, Amal; Afifi, Sofia; Sroor, Amany; Samir, Eman

2011-01-01

The pegmatite bodies of the Eastern Desert of Egypt are widely distributed especially along the Marsa-Alam-Idfu road. The Abu Dob area covers about 150 km 2 of the Arabian Nubian shield at the central part of the Eastern Desert of Egypt. Most of the pegmatite is zoned; the zonation starts with milky quartz at the core followed by alkali feldspar at the margins. The feldspars vary in color from rose to milky and in composition from K-feldspar to Na-feldspar, sometimes interactions of both types are encountered. Thirteen feldspar samples were collected from different locations in the Abu Dob area for measuring the natural radioactivity of 238 U, 232 Th and 40 K using an HPGe detector. The variation in concentration of radionuclides for the area under investigation can be classified into regions of high, medium and low natural radioactivity. The average concentration in BqKg -1 has been observed to be from 9.5 to 183675.7 BqKg -1 for 238 U, between 6.1 and 94,314.2 BqKg -1 for 232 Th and from 0 to 7894.6 BqKg -1 for 40 K. Radium equivalent activities (Ra eq ), dose rate (D R ) and external hazard (H ex ) have also been determined. In the present work, the concentration of rare earth elements are measured for two feldspar samples using two techniques, Environmental Scanning Electron microscope XIL 30 ESEM, Philips, and Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). The existence of rare earth elements in this area are very high and can be used in different important industries.

Natural radioactivity and Rare Earth elements in feldspar samples, Central Eastern desert, Egypt

Energy Technology Data Exchange (ETDEWEB)

Walley El-Dine, Nadia, E-mail: nadia_walley5@hotmail.co [Department of physics, Faculty of girls for Art, Science and Education, Ain Shams University, Heliopolis, Cairo (Egypt); El-Shershaby, Amal [Department of physics, Faculty of girls for Art, Science and Education, Ain Shams University, Heliopolis, Cairo (Egypt); Afifi, Sofia [Nuclear Materials Authority (Egypt); Sroor, Amany; Samir, Eman [Department of physics, Faculty of girls for Art, Science and Education, Ain Shams University, Heliopolis, Cairo (Egypt)

2011-05-15

The pegmatite bodies of the Eastern Desert of Egypt are widely distributed especially along the Marsa-Alam-Idfu road. The Abu Dob area covers about 150 km{sup 2} of the Arabian Nubian shield at the central part of the Eastern Desert of Egypt. Most of the pegmatite is zoned; the zonation starts with milky quartz at the core followed by alkali feldspar at the margins. The feldspars vary in color from rose to milky and in composition from K-feldspar to Na-feldspar, sometimes interactions of both types are encountered. Thirteen feldspar samples were collected from different locations in the Abu Dob area for measuring the natural radioactivity of {sup 238}U, {sup 232}Th and {sup 40}K using an HPGe detector. The variation in concentration of radionuclides for the area under investigation can be classified into regions of high, medium and low natural radioactivity. The average concentration in BqKg{sup -1} has been observed to be from 9.5 to 183675.7 BqKg{sup -1} for {sup 238}U, between 6.1 and 94,314.2 BqKg{sup -1} for {sup 232}Th and from 0 to 7894.6 BqKg{sup -1} for {sup 40}K. Radium equivalent activities (Ra{sub eq}), dose rate (D{sub R}) and external hazard (H{sub ex}) have also been determined. In the present work, the concentration of rare earth elements are measured for two feldspar samples using two techniques, Environmental Scanning Electron microscope XIL 30 ESEM, Philips, and Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). The existence of rare earth elements in this area are very high and can be used in different important industries.

Investigation into the metamorphic Nappes of the Central Scandinavian Caledonides on the basis of Rb-Sr and K-Ar age determination

International Nuclear Information System (INIS)

Reymer, A.P.S.

1979-01-01

This study concerns age determinations on several rock units of metamorphic nappes in the central Scandinavian Caledonides. Rb-Sr analyses on whole-rocks and minerals (biotite, muscovite/phengite, feldspars, garnet) were made as well as K-Ar determinations on biotite, muscovite/phengite, amphibole and feldspar. (Auth.)

Developing Effective Separation of Feldspar and Quartz While Recycling Tailwater by HF Pretreatment

Directory of Open Access Journals (Sweden)

Weiqing Wang

2018-04-01

Full Text Available The effect of hydrofluoric acid (HF pretreatment on flotation of feldspar and quartz using dodecylamine (DDA as collector was investigated by micro-flotation, zeta potential, pyrene fluorescence spectroscopy, attenuated total reflection flourier transformed infrared spectroscopy (ATR-FTIR, scanning electron microscope (SEM, X-ray photoelectron spectroscopy (XPS and bench scale flotation. The micro-flotation tests revealed that there was little difference in the flotation of feldspar and quartz at pH 2, using H2SO4 as pH regulator. After HF pretreatment, the floatability of feldspar significantly increased while the floatability of quartz showed no change. HF pretreatment resulted in leaching of SiO2 and enrichment of Na, K and Al on the feldspar surface. Consequently, the negative surface charge of feldspar increased at pH 2, which allowed for the flotation separation of the feasible minerals. This took place via an increased electrostatic adsorption between DDA and Na, K, Al on the feldspar surface, which effectively increased its hydrophobicity and as a result, improved the floatability of feldspar. An alternative process which exhibited effective separation of quartz and feldspar while recycling the tailwater from the flotation was proposed.

Structures of the K- and Na-components of two-phase feldspar from Primorskii Krai

International Nuclear Information System (INIS)

Organova, N.I.; Marsii, I.M.; Zakharov, N.D.; Nasedkin, V.V.; Borisovskii, S.B.; Rozhdestvenskaya, I.V.; Ivanova, T.I.

1999-01-01

The structures of two components of the decomposed solid solution of an alkali feldspar are refined. These structures exhibit at least two specific features: (1) the complete phase separation into pure K and pure Na phases and (2) an anomalous distribution of Al atoms over four crystallographically independent positions of silicon-aluminum tetrahedra in the Na-component (different from its usual distribution). To explain the results obtained, the ideas of synergetics are invoked (the geological history of the specimen includes a powerful explosion, which threw out the material from the volcano to the Earth's surface)

Petrogenesis of oceanic kimberlites and included mantle megacrysts: the Malaitan alnoite

International Nuclear Information System (INIS)

Neal, C.R.

1988-01-01

The study of unambiguous suboceanic mantle was facilitated by the occurrence of anomalous kimberlite-type intrusives on Malaita in the Solomon Islands. The pseudo-kimberlites were termed alnoites, and are basically mica lamprophyres with melilite in the ground mass. Alnoitic magmas were explosively intruded into the Ontong Java Plateau (OJP) 34 Ma ago. The OJP is a vastly overthickened portion of the Pacific plate which now abuts the Indo-Australian plate. Malaita is considered to be the obducted leading edge of the OJP. Initial diapiric upwelling beneath the OJP produced the proto-alnoite magma. After impingement on the rigid lithosphere, megacrysts fractionation occurred, with augites precipitating first, representing the parental magma. Sea water-altered oceanic crust, which underplated the OJP, was assimilated by the proto-alnoite magma during megacrysts fractionation

Report on the intercomparison run F-1 U and K(Th) in feldspar

International Nuclear Information System (INIS)

1990-01-01

The present report deals with a recent intercomparison on the determination of uranium, thorium and potassium in potassium feldspar, carried out in 1976-77 and involving the participation of 20 institutes who returned a total of 196 individual results on three elements. Analytical techniques employed by the participating institutes included gamma spectrometry, emission spectroscopy, atomic absorption, X-ray fluorescence, fluorimetry and neutron activation. Each of these techniques has its own particular weakness: The basic principles of gamma-spectrometric technique for the determination of U, Th and K are well known. It is, however, difficult to determine the low concentrations of radioactive nuclides which can be found in geological materials due to systematic errors arising from non-equilibration of decay chains in the samples and from other sources including calibration. Determination of uranium in geological materials by non-destructive neutron activation analysis also has some problems. Elements such as Th, Ta, Pt, Ru, Zn and Ba when irradiated in a nuclear reactor with thermal and epithermal neutrons yield radioactive isotopes, the gamma rays of which interfere with those used in uranium determination. Detection limits for three elements U, Th and K for thermal neutron activation have been reported as 0.7, 1.0 and 10 ppb respectively, however, this seems over-optimistic to expect in real-life situations. Measurement of delayed neutrons and fission track methods for uranium and thorium also have interference problems. Fluorimetry is a suitable method for uranium at low concentrations (down to 0.1 ppm) but one has to take care to overcome quenching by removing, or at least diluting, interfering elements. The determination of some important elements in geochemical samples is often difficult because of their small concentration as well as of the presence of interfering matrix elements in the samples. Some systematic differences seem to exist between the methods

Single-grain dating of young sediments using the pIRIR signal from feldspar

DEFF Research Database (Denmark)

Reimann, Tony; Thomsen, Kristina Jørkov; Jain, Mayank

2012-01-01

In this article we test for the first time the potential of single-grains of K-rich feldspar to date well-bleached and poorly bleached sediments using a post-IR IRSL (pIRIR) protocol. We measure natural dose distributions using K-rich feldspars from four coastal samples applying the pIRIR protocol.......5%.The analysis of the well-bleached samples shows that only the brightest 30% of the grains give pIRIR single-grain ages in agreement with the age control; this effect may arise from the suggested correlation between blue emission and potassium content of individual grains. Comparison of single......-grain quartz and feldspar dose distributions from the poorly bleached samples shows that quartz is relatively better bleached; nevertheless, selection of a reliable ‘minimum’ feldspar dose was achieved using two different statistical models....

Comparative study of ice nucleating efficiency of K-feldspar in immersion and deposition freezing modes

Science.gov (United States)

Hiron, T.; Hoffmann, N.; Peckhaus, A.; Kiselev, A. A.; Leisner, T.; Flossmann, A. I.

2016-12-01

One of the main challenges in understanding the evolution of Earth's climate resides in the understanding the role of ice nucleation on the development of tropospheric clouds as well as its initiation. K-feldspar is known to be a very active ice nucleating particle and this study focuses on the characterization of its activity in two heterogeneous nucleation modes, immersion and deposition freezing.We use a newly built humidity-controlled cold stage allowing the simultaneous observation of up to 2000 identical 0.6-nanoliter droplets containing suspension of mineral dust particles. The droplets are first cooled down to observe immersion freezing, the obtained ice crystals are then evaporated and finally, the residual particles are exposed to the water vapor supersaturated with respect to ice.The ice nucleation abilities for the individual residual particles are then compared for the different freezing modes and correlation between immersion ice nuclei and deposition ice nuclei is investigated.Based on the electron microscopy analysis of the residual particles, we discuss the possible relationship between the ice nucleation properties of feldspar and its microstructure. Finally, we discuss the atmospheric implications of our experimental results, using DESCAM, a 1.5D bin-resolved microphysics model.

Strontium and argon isotopes in naturally weathered biotites, muscovites and feldspars

International Nuclear Information System (INIS)

Clauer, N.

1981-01-01

A Rb-Sr and K-Ar isotopical study on progressively weathered biotites, muscovites and feldspars from plutonic and eruptive rocks shows that their continental weathering is a complex phenomenon controlled by environmental conditions. During weathering of biotites, the K-Ar couple often mimics the Rb-Sr couple. The radiogenic Sr and Ar isotopes are systematically leached out, but the behaviour of the elemental Rb, K, Sr and Ar depends upon the environment. In contrast, the Sr and Ar balances of muscovites are maintained, even during very intensive weathering. In mixtures of feldspars, the common Sr seems to be leached out preferentially to the radiogenic isotope, while the K-Ar balance is maintained. (Auth.)

Application of Cathodoluminescence to The Study of Feldspars: Imaging and Spectrometry

Science.gov (United States)

Fonseca, Rute; Couto, Helena

2017-12-01

Cathodoluminescence (CL) studies were carried out on polished thin sections of different feldspar samples (from migmatites, granites, aplite-pegmatites and granitic aggregates) using a hot cathode CL equipment HC3-LM coupled to an optical microscope and to a spectrometer (SpectraPro 2300i and a CCD Pixis 400B detector and the software Winspec32) from the Faculty of Sciences of University of Porto. The system was operated at 14kV and a filament current of 0.18 mA. The samples were coated with a thin gold film using a Cressington 108 Auto device. Luminescence images were acquired during the CL analysis with an adapted digital video-camera (KAPPA PS 40C-285 (DX) with dual stage Peltier cooling) and an acquisition time between 351ms and 3,52s. The CL study, including imaging and spectrometry, proved to be an important tool to complement the feldspar petrography as it contributes to the identification of features not observed under optical microscope. The application of the Cathodoluminescence to feldspar allows distinguishing between potassic feldspar and plagioclase, differentiating generations of feldspar and displaying internal zoning and growth areas, among other. The spectrometry complements the CL imaging. It allows obtaining a qualitative level of emission intensity, which permits the interpretation of the nature of this luminescence in each feldspar. Bands shown in the spectra are related to the existing activator elements. In the present study, it was found an association of each feldspar to different spectra and respective colour. The plagioclases exhibit yellow or green luminescence. The activator element is Mn2+, showing a broad emission band between 550 - 570 nm specially detected on this type of feldspars, due to the replacement of K+ for Mn2+. The potassium feldspars have more or less intense blue colour associated with various activators elements: the activator element is Cu2+ showing a broad emission band between 420±5 nm. This emission band can be

Sorption of Eu(III) at feldspar/water interface. Effects of pH, organic matter, counter ions, and temperature

Energy Technology Data Exchange (ETDEWEB)

Li, Ping; Liang, Jianjun; Fan, Qiaohui [Chinese Academy of Sciences, Lanzhou (China). Key Lab. of Petroleum Resources Research; Wu, Hanyu [Chinese Academy of Sciences, Lanzhou (China). Key Lab. of Petroleum Resources Research; Lanzhou Univ. (China). Radiochemistry Lab.; Yin, Zhuoxin; Pan, Duoqiang; Wu, Wangsuo [Lanzhou Univ. (China). Radiochemistry Lab.; Xu, Di [Chinese Academy of Sciences, Nanjing (China). State Key Lab. of Lake Science and Environment

2017-07-01

The sorption of Eu(III) on potassium feldspar (K-feldspar) was studied under various physicochemical conditions such as pH, temperature, counter ions and organic matter. The results showed that the sorption of Eu(III) on K-feldspar significantly increased with the increase of pH, and high Eu(III) concentration can inhibit such immobility to some extent. The presence of humic acid (HA) can increase the sorption of Eu(III) on K-feldspar in low pH range; while inhibit to a large extent under alkaline conditions. It is very interesting that at pH ∝6.5, high ionic strength can promote the sorption of Eu(III) on K-feldspar in the presence of HA. In contrast, Eu(III) sorption was restricted obviously by NaCl in the absence of HA. The sorption procedure was involved with ion exchange and/or outer-sphere complexation as well as inner-sphere complexation. The presence of F{sup -} and PO{sub 4}{sup 3-} dramatically enhanced Eu(III) sorption on K-feldspar, whereas both SO{sub 4}{sup 2-} and CO{sub 3}{sup 2-} had negative effects on Eu(III) sorption. X-ray photoelectron spectroscopy analysis indicated that Eu(III) tended to form hydrolysates at high initial concentration (3 x 10{sup -4} mol/L) and high temperature (338 K).

Apatite intergrowths in clinopyroxene megacrysts from the Ostrzyca Proboszczowicka (SW Poland) basanite

Science.gov (United States)

Lipa, Danuta; Puziewicz, Jacek; Ntaflos, Theodoros; Matusiak-Małek, Magdalena

2015-04-01

The Cenozoic basanite from the Ostrzyca Proboszczowicka in Lower Silesia (SW Poland) belongs to numerous lavas occurring in the NE part of the Central European Volcanic Province. Basanite contains clinopyroxene megacrysts up to 3 cm in size. The clinopyroxene has the composition of aluminian-sodian diopside (mg# 0.61-0.70, 0.08-0.12 atoms Na pfu and 0.88-0.93 atoms Ca pfu). Cr is absent. The REE contents are above the primitive mantle reaching up to 18 x PM at Nd. Primitive-mantle normalized REE patterns show enrichment in LREE relative to HREE (LaN/LuN=3.81-5.01). The REE patterns of all the megacrysts show deflection in La-Nd. The trace element patterns are characterized by positive Zr, Hf and in some cases also Ta anomalies, and negative U, La, Sr, Ti and Pb ones. In some samples strong depletion (down to 0.01 x PM) in Rb and Ba is observed.The Ostrzyca megacrysts formed cumulate, which crystallized from magma similar to the host basanite, but more fractionated and enriched in REE, particularly in LREE (Lipa et al., 2014). This happened at mid-crustal depths (10-15 km) and the new pulse of basanitic magma entrained the crystals forming the non-solidified cumulate and brought them to the surface (Lipa et al., 2014). Clinopyroxene megacrysts contain large, transparent, euhedral apatite crystals up to 7 mm. The major element composition indicates the fluor-apatite with F content ranging from 0.87 to 1.93 wt.%. Chlorine content is strongly variable between grains (0.05-1.75 wt.%). Apatite is strongly enriched in LREE relative to HREE (LaN/LuN=60.39-62.23, about 1000 x PM for LREE and about 10 x PM for HREE). The REE patterns are nearly linear, with slight positive Nd and Gd anomalies. The trace element patterns are characterized by very strong negative anomalies of HFSE (Nb, Ta, Zr, Hf, Ti) and Pb, and weaker negative Sr anomaly. Concentration of Yb and Lu is on the level 10 x PM, whereas Rb, Hf and Ti are depleted relative to PM. Apatite preceded clinopyroxene

Cationic polyelectrolyte induced separation of some inorganic contaminants and their mixture (zirconium silicate, kaolin, K-feldspar, zinc oxide) as well as of the paraffin oil from water.

Science.gov (United States)

Ghimici, Luminita

2016-03-15

The flocculation efficiency of a cationic polyelectrolyte with quaternary ammonium salt groups in the backbone, namely PCA5 was evaluated on zirconium silicate (kreutzonit), kaolin, K- feldspar and zinc oxide (ZnO) suspensions prepared either with each pollutant or with their mixture. The effect of several parameters such as settling time, polymer dose and the pollutant type on the separation efficacy was evaluated and followed by optical density and zeta potential measurements. Except for ZnO, the interactions between PCA5 and suspended particles led to low residual turbidity values (around 4% for kreutzonit, 5% for kaolin and 8% for K-feldspar) as well as to the reduction of flocs settling time (from 1200 min to 30 min and 120 min in case of kaolinit and K-feldspar, respectively), that meant a high efficiency in their separation. The negative value of the zeta potential and flocs size measurements, at the optimum polymer dose, point to contribution from charge patch mechanism for the particles flocculation. A good efficiency of PCA5 in separation of paraffin oil (a minimum residual turbidity of 9.8%) has been also found. Copyright © 2015 Elsevier Ltd. All rights reserved.

Measurement of the dose in quartz in the presence of feldspar contamination

DEFF Research Database (Denmark)

Wallinga, J.; Murray, A.S.; Bøtter-Jensen, L.

2002-01-01

To allow the determination of the dose in quartz in the presence of feldspar contamination. the quartz-to-feldspar optically stimulated luminescence (OSL) ratio needs to be maximised. Experiments were carried Out to find the optimum procedure to bleach the feldspar by exposure to infrared light...

Bleaching of the thermoluminescence of feldspars by sunlight

International Nuclear Information System (INIS)

Robertson, G.B.; Prescott, J.R.; Hutton, J.T.

1991-01-01

Feldspars are an important component of materials used for thermoluminescence (TL) and photoluminescence (PL) dating of sediments; and successful dating implies a knowledge of the degree of re-setting by exposure to sunlight of the stored luminescence energy. We have studied the bleaching by full sunlight of the TL of six alkali feldspars of representative composition and of one oligoclase. The high potassium and high sodium feldspars are the brightest, and are also the least easily bleached, whereas those of intermediate (K-Na) composition bleach quickly. On a time scale of upwards of 16 h, all samples would have bleached enough for them to be useful for TL dating. A search was made for individual glow curve peaks that bleach particularly quickly (and are thus similar to the well-known 325 o C peak used in the TL dating of quartz). In the samples studied, there was only one glow curve peak that was selectively susceptible to bleaching: the 280 o C peak in oligoclase. (author)

Feldspar, Infrared Stimulated Luminescence

DEFF Research Database (Denmark)

Jain, Mayank

2014-01-01

This entry primarily concerns the characteristics and the origins of infrared-stimulated luminescence in feldspars.......This entry primarily concerns the characteristics and the origins of infrared-stimulated luminescence in feldspars....

Mechanical behavior of alumina and alumina-feldspar based ceramics in an acetic acid (4%) environment

International Nuclear Information System (INIS)

Stumpf, Aisha S.G.; Bergmann, Carlos P.; Vicenzi, Juliane; Fetter, Rebecca; Mundstock, Karina S.

2009-01-01

This study investigates the mechanical properties of alumina-feldspar based ceramics when exposed to an aggressive environment (acetic acid 4%). Alumina ceramics containing different concentrations of feldspar (0%, 1%, 5%, 10%, or 40%) were sintered at either 1300, 1600, or 1700 o C. Flaws (of width 0%, 30%, or 50%) were introduced into the specimens using a saw. Half of these ceramic bodies were exposed to acetic acid. Their flexural strength, K IC , and porosity were measured and the fractured samples were evaluated using scanning electronic- and optical microscopy. It was found that in the ceramic bodies sintered at 1600 o C, feldspar content up to 10% improved flexural strength and K IC, and reduced porosities. Generally, it was found that acetic acid had a weakening effect on the flexural strength of samples sintered at 1700 o C but a beneficial effect on K IC of ceramics sintered at 1600 o C. It was concluded that alumina-based ceramics with feldspar content up to 10% and sintered at higher temperatures would perform better in an aggressive environment similar to oral cavity.

Hydrothermal alteration of plagioclase and growth of secondary feldspar in the Hengill Volcanic Centre, SW Iceland

Science.gov (United States)

Larsson, D.; Grönvold, K.; Oskarsson, N.; Gunnlaugsson, E.

2002-05-01

Dissolution of igneous feldspar and the formation and occurrence of secondary feldspar in tholeiitic basalts from the Hengill volcanic centre, in SW Iceland was studied by microprobe analysis of cuttings from two ca. 2000 m deep geothermal wells. Well NG-7 in Nesjavellir represents a geothermal system in a rift zone where the intensity of young, insignificantly altered intrusions increases with depth. Well KhG-1 in Kolviðarhóll represents the margin of a rift zone where the intensity of intrusives is lower and the intensity of alteration higher. This marginal well represents altered basaltic crust in an early retrograde state. The secondary plagioclase in both wells is mainly oligoclase, occurring in association with K-feldspar and chlorite±actinolite. The texture of this assemblage depends on the lithology and intensity of alteration. In Nesjavellir (NG-7) the composition of secondary albite-oligoclase is correlated with the host-rock composition. This connection is not apparent in more intensely altered samples from Kolviðarhóll (KhG-1). The influence of temperature on composition of secondary Na-feldspar is unclear in both wells although Ca is expected to increase with temperature. Any temperature dependence may be suppressed by the influence of rock composition in Nesjavellir and by retrograde conditions at Kolviðarhóll. The absence of clear compositional gradients between igneous plagioclase and secondary feldspar and between Na-feldspar and K-feldspar suggests that secondary feldspars formed by dissolution precipitation reactions.

Ice nucleation activity of silicates and aluminosilicates in pure water and aqueous solutions - Part 1: The K-feldspar microcline

Science.gov (United States)

Kumar, Anand; Marcolli, Claudia; Luo, Beiping; Peter, Thomas

2018-05-01

Potassium-containing feldspars (K-feldspars) have been considered as key mineral dusts for ice nucleation (IN) in mixed-phase clouds. To investigate the effect of solutes on their IN efficiency, we performed immersion freezing experiments with the K-feldspar microcline, which is highly IN active. Freezing of emulsified droplets with microcline suspended in aqueous solutions of NH3, (NH4)2SO4, NH4HSO4, NH4NO3, NH4Cl, Na2SO4, H2SO4, K2SO4 and KCl, with solute concentrations corresponding to water activities aw = 0.9-1.0, were investigated by means of a differential scanning calorimeter (DSC). The measured heterogeneous IN onset temperatures, Thet(aw), deviate strongly from ThetΔawhet(aw), the values calculated from the water-activity-based approach (where ThetΔawhet(aw) = Tmelt(aw + Δawhet) with a constant offset Δawhet with respect to the ice melting point curve). Surprisingly, for very dilute solutions of NH3 and NH4+ salts (molalities ≲1 mol kg-1 corresponding to aw ≳ 0.96), we find IN temperatures raised by up to 4.5 K above the onset freezing temperature of microcline in pure water (Thet(aw = 1)) and 5.5 K above ThetΔawhet(aw), revealing NH3 and NH4+ to significantly enhance the IN of the microcline surface. Conversely, more concentrated NH3 and NH4+ solutions show a depression of the onset temperature below ThetΔawhet(aw) by as much as 13.5 K caused by a decline in IN ability accompanied with a reduction in the volume fraction of water frozen heterogeneously. All salt solutions not containing NH4+ as cation exhibit nucleation temperatures Thet(aw) NH4+). However, the presence of a similar increase in IN efficiency in dilute ammonia solutions indicates that the cation exchange cannot explain the increase in IN temperatures. Instead, we hypothesize that NH3 molecules hydrogen bonded on the microcline surface form an ice-like overlayer, which provides hydrogen bonding favorable for ice to nucleate on, thus enhancing both the freezing temperatures and the

Testing the potential of an elevated temperature IRSL signal from K-feldspar

DEFF Research Database (Denmark)

Buylaert, Jan-Pieter; Murray, A.S.; Thomsen, Kristina Jørkov

2009-01-01

on laboratory tests (recycling ratio, recuperation, dose recovery) we show that our SAR protocol is suitable for these samples. The observed post-IR IR fading rates (mean g2days = 1.62 ± 0.06%/decade, n = 24; assuming logarithmic fading) are significantly lower than those measured at 50 °C (mean g2days = 3...... the conventional IRSL signal stimulated at 50 °C and detected in the blue–violet region of the spectrum. One of these was the post-IR IR signal in which first an IR bleach is carried out at a low temperature (e.g. 100 s at 50 °C) and a remaining IRSL signal is measured at an elevated temperature (100 s at 225 °C......; detection in the blue–violet region). It is the latter signal that is of interest in this paper. We test such a post-IR IR dating protocol on K-feldspar extracts from a variety of locations and depositional environments and compare the results with those from the conventional IR at 50 °C protocol. Based...

Comparison of the properties of various optically stimulated luminescence signals from potassium feldspar

International Nuclear Information System (INIS)

Fu Xiao; Zhang Jiafu; Zhou Liping

2012-01-01

Various optically stimulated luminescence signals from K-feldspar have been used to determine the equivalent doses of sediment samples. Understanding the properties of these optical signals is critical to evaluate their applicability and limitations to optical dating. In this paper, some properties of IRSL, post-IR OSL and post-IR IRSL signals (detected in the UV region using U-340 filters) from a museum sample of K-feldspar were investigated by analyzing the relationships between optical and TL signals, and the effect of optical bleaching and heating on optical signals. The trap parameters of the different optical signals were calculated using the pulse annealing method. The results show that this sample exhibits two regenerated TL peaks at ∼140 and ∼330 °C. Corresponding to the low temperature TL peak, the OSL and post-IR OSL signals appear to be more associated with lower temperature TL than the IRSL signal measured at 50 °C. Corresponding to the high temperature TL peak, the post-IR IRSL signals mainly originate from the more thermally stable traps associated with the high temperature TL, compared with the IRSL and post-IR OSL signals. However, the post-IR IRSL 225°C signal is shown to be hard to be bleached by blue light and simulated sunlight, compared with the IRSL 50°C and low temperature post-IR IRSL signals. The implication for optical dating is that the elevated temperature post-IR IRSL signals can be preferentially applied over other signals from K-feldspar, but it is desirable that the effectiveness of the pre-depositional zeroing of these signals is assessed.

Red-IR stimulated luminescence in K-feldspar: Single or multiple trap origin?

DEFF Research Database (Denmark)

Andersen, Martin Thalbitzer; Jain, Mayank; Tidemand-Lichtenberg, Peter

2012-01-01

We investigate on the origins of the infra-red stimulated luminescence (IRSL) signals in 3 potassium feldspars based on IR-red spectroscopy (700–1050 nm) using a fiber-coupled tunable Ti:Sapphire laser, in combination with different thermal and optical (pre)treatments of the samples. We also...

Time-resolved luminescence from feldspars: New insight into fading

DEFF Research Database (Denmark)

Tsukamoto, S.; Denby, P.M.; Murray, A.S.

2006-01-01

Time-resolved infrared optically stimulated luminescence (IR-OSL) signals of K- and Na-feldspar samples extracted from sediments were measured in UV, blue and red detection windows, using a fast photon counter and pulsed IR stimulation (lambda = 875 nm). We observe that the relative contribution ...

U-Pb ages for two tonalitic gneisses, pegmatitic granites, and K-feldspar porphyries, Olkiluoto study site, Eurajoki, SW Finland

International Nuclear Information System (INIS)

Maenttaeri, I.; Lindberg, A.; Aaltonen, I.

2007-08-01

including inherited Archaean and ∼2.05- 1.95 Ga populations and thus the age distribution resembles that of the Svecofennian sedimentary rocks. The youngest U-Pb data from zircon cores and zircons scatter between 1.90 and 1.85 Ga. As there is no common factor to combine the data, also these are considered as inherited zircon material. Similarly and coevally with the other KFP sample A1882, the low Th/U rims indicate metamorphism at 1.82-1.83 Ga (1824± 5 Ma). The absolute minimum ages for the K-feldspar porphyry samples are determined by 1.80-1.81 Ga monazites. (orig.)

Timing of the deglaciation in southern Patagonia: Testing the applicability of K-Feldspar IRSL

DEFF Research Database (Denmark)

Blomdin, Robin; Murray, Andrew S.; Thomsen, Kristina Jørkov

2012-01-01

need evaluation against an absolute chronology. The aim of this project is to investigate the applicability of OSL dating to sediments from southern Patagonia; in particular, we examine the dating potential of K-feldspar IRSL signals. Samples were collected from landforms interpreted as being deposited...... to our individual dose estimates based on the over-dispersion (OD) observed in laboratory gamma dose recovery experiments (22% for small aliquots and 18% for single grains). Then the possible effects of incomplete bleaching and differential fading are examined. For our natural samples we observe...... environmental ODs between 30 and 130% and mean residual doses between ∼30 and 80 Gy. Minimum age models are used to identify the part of the dose population that is most likely to have been well-bleached and results from these models are compared. The models give ages that are consistent with each other...

Stability of IRSL signals from sedimentary K-feldspar samples

DEFF Research Database (Denmark)

Thomsen, Kristina Jørkov; Murray, A.S.; Jain, Mayank

2011-01-01

for potassium-rich sedimentary feldspars. We show that the natural post-IR IRSL (pIRIR) signal from a 3.6 Ma old sample is in apparent saturation on a laboratory generated dose response curve, i.e. it does not show detectable fading in nature although a low fading rate is observed on laboratory time scales. We...... be explained in terms of either a single- or multiple-trap model. We present evidence that may suggest that at least part of pIRIR signal is derived from a high temperature trap (∼550°C thermoluminescence (TL) peak), although again the data can also be explained in terms of a single-trap model. Finally, we...

Determination of potassium in feldspars by beta counting using a GM multicounter system

Energy Technology Data Exchange (ETDEWEB)

Boetter-Jensen, L; Mejdahl, V

1985-01-01

A gas flow multicounter system developed at Risoe National laboratory for low-level beta counting applications was adopted for measuring potassium in feldspars extracted from archaeological and geological materials, in connection with TL dating work. A guard counter reduces the background by using an anticoincidence technique. Calibration was accomplished by measuring KCl and a feldspar standard. A potassium content of 1% yields a net beta count rate (background subtracted) of about 40 c.p.h.; the background is around 15 c.p.h. The precision in repeated measurements is better than 2% and the estimated accuracy is about 3%.

The Shahewan rapakivi-textured granite – quartz monzonite pluton, Qinling orogen, central China: mineral composition and petrogenetic significance

Directory of Open Access Journals (Sweden)

Xiaoxia Wang

2002-01-01

Full Text Available The Mesozoic Shahewan pluton consists of four texturally different types of biotite-hornblende quartz monzonite. In the porphyritic types alkali feldspar occurs as euhedral or ovoidal megacrysts that are often mantled by one or more plagioclase shells, and as smaller grains in the groundmass. Quartz, plagioclase (An20–28, biotite, and hornblende occur as inclusions in the alkali feldspar megacrystsand, more abundantly, in the groundmass. Euhedral quartz crystals in the groundmass are not as common and well developed as in typical rapakivi granite. Compared to typical rapakivi granites, the mafic minerals (biotite and hornblende are rich in Mg and poor in Fe, and the whole rock is low in Si, K, F, Ga, Zr, LREE, Fe/Mg, and K/Na. The rocks of the Shahewan pluton are thus regarded as rapakivi-textured quartz monzonites and granites but not true rapakivi granites.

Ice nucleation activity of silicates and aluminosilicates in pure water and aqueous solutions – Part 1: The K-feldspar microcline

Directory of Open Access Journals (Sweden)

A. Kumar

2018-05-01

Full Text Available Potassium-containing feldspars (K-feldspars have been considered as key mineral dusts for ice nucleation (IN in mixed-phase clouds. To investigate the effect of solutes on their IN efficiency, we performed immersion freezing experiments with the K-feldspar microcline, which is highly IN active. Freezing of emulsified droplets with microcline suspended in aqueous solutions of NH3, (NH42SO4, NH4HSO4, NH4NO3, NH4Cl, Na2SO4, H2SO4, K2SO4 and KCl, with solute concentrations corresponding to water activities aw  =  0.9–1.0, were investigated by means of a differential scanning calorimeter (DSC. The measured heterogeneous IN onset temperatures, Thet(aw, deviate strongly from ThetΔawhet(aw, the values calculated from the water-activity-based approach (where ThetΔawhet(aw = Tmelt(aw + Δawhet with a constant offset Δawhet with respect to the ice melting point curve. Surprisingly, for very dilute solutions of NH3 and NH4+ salts (molalities ≲1 mol kg−1 corresponding to aw ≳ 0.96, we find IN temperatures raised by up to 4.5 K above the onset freezing temperature of microcline in pure water (Thet(aw = 1 and 5.5 K above ThetΔawhet(aw, revealing NH3 and NH4+ to significantly enhance the IN of the microcline surface. Conversely, more concentrated NH3 and NH4+ solutions show a depression of the onset temperature below ThetΔawhet(aw by as much as 13.5 K caused by a decline in IN ability accompanied with a reduction in the volume fraction of water frozen heterogeneously. All salt solutions not containing NH4+ as cation exhibit nucleation temperatures Thet(aw < ThetΔawhet(aw even at very small solute concentrations. In all these cases, the heterogeneous freezing peak displays a decrease as solute concentration increases. This deviation from Δawhet  =  const. indicates specific chemical interactions between particular solutes and the microcline surface not captured by the water-activity-based approach. One

Time-resolved infrared stimulated luminescence signals in feldspars: Analysis based on exponential and stretched exponential functions

International Nuclear Information System (INIS)

Pagonis, V.; Morthekai, P.; Singhvi, A.K.; Thomas, J.; Balaram, V.; Kitis, G.; Chen, R.

2012-01-01

Time-resolved infrared-stimulated luminescence (TR-IRSL) signals from feldspar samples have been the subject of several recent experimental studies. These signals are of importance in the field of luminescence dating, since they exhibit smaller fading effects than the commonly employed continuous-wave infrared signals (CW-IRSL). This paper presents a semi-empirical analysis of TR-IRSL data from feldspar samples, by using a linear combination of exponential and stretched exponential (SE) functions. The best possible estimates of the five parameters in this semi-empirical approach are obtained using five popular commercially available software packages, and by employing a variety of global optimization techniques. The results from all types of software and from the different fitting algorithms were found to be in close agreement with each other, indicating that a global optimum solution has likely been reached during the fitting process. Four complete sets of TR-IRSL data on well-characterized natural feldspars were fitted by using such a linear combination of exponential and SE functions. The dependence of the extracted fitting parameters on the stimulation temperature is discussed within the context of a recently proposed model of luminescence processes in feldspar. Three of the four feldspar samples studied in this paper are K-rich, and these exhibited different behavior at higher stimulation temperatures, than the fourth sample which was a Na-rich feldspar. The new method of analysis proposed in this paper can help isolate mathematically the more thermally stable components, and hence could lead to better dating applications in these materials. - Highlights: ► TR-IRSL from four feldspars were analyzed using exponential and stretched exponential functions. ► A variety of global optimization techniques give good agreement. ► Na-rich sample behavior is different from the three K-rich samples. ► Experimental data are fitted for stimulation temperatures

Mathematical characterization of continuous wave infrared stimulated luminescence signals (CW-IRSL) from feldspars

International Nuclear Information System (INIS)

Pagonis, V.; Phan, Huy; Goodnow, Rebecca; Rosenfeld, Sara; Morthekai, P.

2014-01-01

Continuous-wave infrared stimulated luminescence signals (CW-IRSL) from feldspars have been the subject of many experimental studies, due to their importance in luminescence dating and dosimetry. Accurate mathematical characterization of the shape of these CW-IRSL signals in feldspars is of practical and theoretical importance, especially in connection with “anomalous fading” of luminescence signals in dating studies. These signals are known to decay in a non-exponential manner and their exact mathematical shape as a function of stimulation time is an open research question. At long stimulation times the IRSL decay has been shown experimentally to follow a power law of decay, and previous researchers have attempted to fit the overall shape of these signals empirically using the well known Becquerel function (or compressed hyperbola decay law). This paper investigates the possibility of fitting CW-IRSL curves using either the Becquerel decay law, or a recently developed analytical equation based on localized electronic recombination of donor–acceptor pairs in luminescent materials. It is shown that both mathematical approaches can give excellent fits to experimental CW-IRSL curves, and the precision of the fitting process is studied by analyzing a series of curves measured using a single aliquot of a feldspar sample. Both fitting equations are solutions of differential equations involving numerically similar time dependent recombination probabilities k(t). It is concluded that both fitting equations provide approximately equivalent mathematical descriptions of the CW-IRSL curves in feldspars, and can be used as mathematical representations of the shape of CW-IRSL signals. - Highlights: • Feldspar CW-IRSL curves fitted using Becquerel decay law and new analytical equation. • Both mathematical approaches give excellent fits to experimental CW-IRSL curves. • Series of experimental CW-IRSL curves analyzed using both fitting expressions. • The time

Feldspar dissolution rates in the Topopah Spring Tuff, Yucca Mountain, Nevada

Science.gov (United States)

Bryan, C.R.; Helean, K.B.; Marshall, B.D.; Brady, P.V.

2009-01-01

Two different field-based methods are used here to calculate feldspar dissolution rates in the Topopah Spring Tuff, the host rock for the proposed nuclear waste repository at Yucca Mountain, Nevada. The center of the tuff is a high silica rhyolite, consisting largely of alkali feldspar (???60 wt%) and quartz polymorphs (???35 wt%) that formed by devitrification of rhyolitic glass as the tuff cooled. First, the abundance of secondary aluminosilicates is used to estimate the cumulative amount of feldspar dissolution over the history of the tuff, and an ambient dissolution rate is calculated by using the estimated thermal history. Second, the feldspar dissolution rate is calculated by using measured Sr isotope compositions for the pore water and rock. Pore waters display systematic changes in Sr isotopic composition with depth that are caused by feldspar dissolution. The range in dissolution rates determined from secondary mineral abundances varies from 10-16 to 10-17 mol s-1 kg tuff-1 with the largest uncertainty being the effect of the early thermal history of the tuff. Dissolution rates based on pore water Sr isotopic data were calculated by treating percolation flux parametrically, and vary from 10-15 to 10-16 mol s-1 kg tuff-1 for percolation fluxes of 15 mm a-1 and 1 mm a-1, respectively. Reconciling the rates from the two methods requires that percolation fluxes at the sampled locations be a few mm a-1 or less. The calculated feldspar dissolution rates are low relative to other measured field-based feldspar dissolution rates, possibly due to the age (12.8 Ma) of the unsaturated system at Yucca Mountain; because oxidizing and organic-poor conditions limit biological activity; and/or because elevated silica concentrations in the pore waters (???50 mg L-1) may inhibit feldspar dissolution. ?? 2009 Elsevier Ltd. All rights reserved.

Validating post IR-IRSL dating on K-feldspars through comparison with quartz OSL ages

NARCIS (Netherlands)

Kars, R.H.; Busschers, F.S.; Wallinga, J.

2012-01-01

Recent developments have opened up the possibilities of using potassium feldspar for dating Pleistocene sediments; a stable (less-fading) part of the infrared stimulated luminescence (IRSL) signal can be selected by largely depleting the unstable part of the IR signal, using a combination of thermal

Use of rice straw ash as substitute of feldspar in triaxial porcelain

International Nuclear Information System (INIS)

Alvaro Guzman, A.; Silverio Delvasto, A.; Enrique Sanchez, V.; Vicente Amigo, B.

2013-01-01

The substitution of raw materials for processing high energy consumption materials by agricultural and agro-industrial wastes causes a positive impacts on the environment preservation. One of these residues is rice straw, which according to FAO estimation, its annual production is about 600 million tons. In this research was studied the use of rice straw ash as substitute of the use of feldspar in the white ware production. Clay-feldspar-quartz porcelains are referred to as triaxial white ware. Specimens of semidry triaxial mixtures, where feldspar was substituted for different percentages of CTA, were prepared by uniaxial pressing, followed by drying and sintering. Physical and mechanical properties of sintered bodies were evaluated. The porosity and the compressive strength of the fired pieces do increase with additions of up to 75% of CTA in substitution of feldspar. Their mineralogical phases were determined by DRX and SEM; grains of quartz, and needles of primary and secondary mullite were identified in a vitreous phase. It was concluded that feldspar can be substituted positively by CTA in white ware pastes. (Author) 22 refs.

Climatic aridity over India 11,000 years ago: Evidence from feldspar distribution in shelf sediments

Digital Repository Service at National Institute of Oceanography (India)

Hashimi, N.H.; Nair, R.R.

Feldspars and quartz contents of sand and silt fractions of forty three samples from the western continental shelf of India were determined by the X-ray diffraction method. The results indicate that the feldspar content in the relict (9000...

Atmospheric weathering and silica-coated feldspar: analogy with zeolite molecular sieves, granite weathering, soil formation, ornamental slabs, and ceramics.

Science.gov (United States)

Smith, J V

1998-03-31

Feldspar surfaces respond to chemical, biological, and mechanical weathering. The simplest termination is hydroxyl (OH), which interacts with any adsorption layer. Acid leaching of alkalis and aluminum generated a silica-rich, nanometers-thick skin on certain feldspars. Natural K, Na-feldspars develop fragile surfaces as etch pits expand into micrometer honeycombs, possibly colonized by lichens. Most crystals have various irregular coats. Based on surface-catalytic processes in molecular sieve zeolites, I proposed that some natural feldspars lose weakly bonded Al-OH (aluminol) to yield surfaces terminated by strongly bonded Si-OH (silanol). This might explain why some old feldspar-bearing rocks weather slower than predicted from brief laboratory dissolution. Lack of an Al-OH infrared frequency from a feldspar surface is consistent with such a silanol-dominated surface. Raman spectra of altered patches on acid-leached albite correspond with amorphous silica rather than hydroxylated silica-feldspar, but natural feldspar may respond differently. The crystal structure of H-exchanged feldspar provides atomic positions for computer modeling of complex ideas for silica-terminated feldspar surfaces. Natural weathering also depends on swings of temperature and hydration, plus transport of particles, molecules, and ionic complexes by rain and wind. Soil formation might be enhanced by crushing granitic outcrops to generate new Al-rich surfaces favorable for chemical and biological weathering. Ornamental slabs used by architects and monumental masons might last longer by minimizing mechanical abrasion during sawing and polishing and by silicifying the surface. Silica-terminated feldspar might be a promising ceramic surface.

Determination of Potassium in Feldspars by Beta Counting Using a GM Multicounter System

DEFF Research Database (Denmark)

Bøtter-Jensen, Lars; Mejdahl, V.

1985-01-01

A gas flow multicounter system developed at Riso National Laboratory for low-level beta counting applications was adopted for measuring potassium in feldspars extracted from archaeological and geological materials, in connection with TL dating work. A guard counter reduces the background by using...

On the shape of continuous wave infrared stimulated luminescence signals from feldspars: A case study

DEFF Research Database (Denmark)

Pagonis, V.; Jain, Mayank; Thomsen, Kristina Jørkov

2014-01-01

The continuous-wave IRSL (CW-IRSL) signals from feldspars are known to decay in a non-exponential manner, and their exact mathematical description is of great importance in dosimetric and dating studies. This paper investigates the possibility of fitting experimental CW-IRSL curves from a variety...... to guide future modeling work on luminescence processes in feldspars. Small statistical differences were found between K-rich and Na-rich fractions of the same sample. However, the experimental data shows that the parameters depend on the irradiation dose, but do not depend on the time elapsed after...

Can cathodoluminescence of feldspar be used as provenance indicator?

Science.gov (United States)

Scholonek, Christiane; Augustsson, Carita

2016-05-01

We have studied feldspar from crystalline rocks for its textural and spectral cathodoluminescence (CL) characteristics with the aim to reveal their provenance potential. We analyzed ca. 60 rock samples of plutonic, volcanic, metamorphic, and pegmatitic origin from different continents and of 16 Ma to 2 Ga age for their feldspar CL textures and ca. 1200 feldspar crystals from these rocks for their CL color spectra. Among the analyzed rocks, igneous feldspar is most commonly zoned, whereby oscillatory zoning can be confirmed to be typical for volcanic plagioclase. The volcanic plagioclase also less commonly contains twin lamellae that are visible in CL light than crystals from other rock types. Alkali feldspar, particularly from igneous and pegmatitic rocks, was noted to be most affected by alteration features, visible as dark spots, lines and irregular areas. The size of all textural features of up to ca. 150 μm, in combination with possible alteration in both the source area and the sedimentary system, makes the CL textures of feldspar possible to use for qualitative provenance research only. We observed alkali feldspar mostly to luminesce in a bluish color and sometimes in red, and plagioclase in green to yellow. The corresponding CL spectra are dominated by three apparent intensity peaks at 440-520 nm (mainly blue), 540-620 nm (mainly green) and 680-740 nm (red to infrared). A dominance of the peak in the green wavelength interval over the blue one for plagioclase makes CL particularly useful for the differentiation of plagioclase from alkali feldspar. An apparent peak position in red to infrared at < 710 nm for plagioclase mainly is present in mafic rocks. Present-day coastal sand from Peru containing feldspar with the red to infrared peak position mainly exceeding 725 nm for northern Peruvian sand and a larger variety for sand from southern Peru illustrates a discriminative effect of different source areas. We conclude that the provenance application

IR-RF dating of sand-sized K-feldspar extracts: A test of accuracy

International Nuclear Information System (INIS)

Buylaert, J.-P.; Jain, M.; Murray, A.S.; Thomsen, K.J.; Lapp, T.

2012-01-01

In this paper we use a recently developed radioluminescence (RL) attachment to the Risø TL/OSL reader to test the InfraRed-RadioFluorescence (IR-RF) dating method applied to K-feldspar rich extracts from our known-age archive samples. We present experiments to characterise the instrument performance and to test the reproducibility of IR-RF measurements. These experiments illustrate the high sensitivity and dose rate of our RL system, the negligible influence of the turntable movement on IR-RF signals and the effectiveness of the built in 395 nm LED at bleaching IR-RF signals. We measure IR-RF ages on a set of samples with independent age control using a robust analytical method, which is able to detect any possible sensitivity change. Our IR-RF ages do not agree well with the independent age control; the ages of the younger samples (20–45 ka) are significantly over-estimated while the ages of the older samples (∼130 ka) are significantly under-estimated. Experiments are undertaken to investigate this disagreement and our results indicate that they can most likely be explained by 1) the difficulty of defining the correct bleaching level prior to regeneration measurements, 2) signal instability, 3) sensitivity changes between the additive dose and regenerative dose measurements, or a combination of these three factors.

Granitoids of the Dry Valleys area, southern Victoria Land, Antarctica : plutons, field relationships, and isotopic dating

International Nuclear Information System (INIS)

Allibone, A.H.; Cox, S.C.; Johnstone, R.D.

1993-01-01

Detailed mapping throughout much of the Dry Valleys area indicates the region is underlain by 15 major granitoid plutons and numerous smaller plugs and dikes. Intrusive relationships of these plutons and dikes indicate repeated intrusion of superficially similar granitoids at different times. Sufficient internal lithologic variation occurs within individual plutons, to allow correlation with several of the previously defined granitoid units based on lithologic character. Consequently, previous subdivision schemes based on lithology are no longer tenable and are here replaced with a subdivision scheme based on the identification of individual plutons. The elongate, concordant Bonney, Denton, Cavendish, and Wheeler Plutons, which range in composition between monzodiorite and granodiorite, are the oldest relatively undeformed plutons in the Dry Valleys area. Each pluton is characterised by flow alignment of K-feldspar megacrysts, hornblende, biotite, and mafic enclaves. Field relationships and radiometric dating indicate these are deep-level plutons, emplaced synchronous with upper amphibolite facies metamorphism of the adjacent Koettlitz Group between 589 and 490 Ma ago. Elongate, discordant plutons of equigranular homogeneous biotite granodiorite and granite (Hedley, Valhalla, St Johns, Suess) were subsequently emplaced by stoping at a relatively high crustal level at 490 Ma. These eight plutons are cut by numerous swarms of Vanda mafic and felsic porphyry dikes. The ovoid, discordant, high level Pearse, Nibelungen, Orestes, Brownworth, Swinford, and Harker Plutons, emplaced between c. 486 and 477 Ma, display mutually crosscutting relationships with the youngest of the Vanda dikes. These younger plutons range in composition between monzonite and granite. Some are characterised by K-feldspar megacrystic textures superficially similar to some of the oldest concordant plutons. (author). 57 refs.; 2 tabs.; 4 figs

Electrons in feldspar I: On the wavefunction of electrons trapped at simple lattice defects

DEFF Research Database (Denmark)

Poolton, H.R.J.; Wallinga, J.; Murray, A.S.

2002-01-01

The purpose of this article is to make an initial consideration of the physical properties of electrons trapped at classic hydrogenic lattice defects in feldspar. We are particularly interested to determine the radial extent of the electron wavefunctions in the ground and excited states. It is sh......The purpose of this article is to make an initial consideration of the physical properties of electrons trapped at classic hydrogenic lattice defects in feldspar. We are particularly interested to determine the radial extent of the electron wavefunctions in the ground and excited states...

Quartz and K-feldspar luminescence dating of sedimentation in the North Bohai coastal area (NE China) since the late pleistocene

Science.gov (United States)

Li, Yan; Shang, Zhiwen; Tsukamoto, Sumiko; Tamura, Toru; Yi, Liang; Wang, Hong; Frechen, Manfred; Li, Jianfen; Jiang, Xingyu

2018-02-01

In this study, luminescence dating of core sediments from the North Bohai Coast (China) was applied to provide a high-resolution chronological constraint, on a better understanding of the Holocene marine-terrestrial interaction. The studied sedimentary sequence contains a terrigenous deposit, a transgressive deposit and a prograding deltaic succession; all are believed to have formed during the late Pleistocene. To establish a reliable luminescence chronology, the luminescence signals of ten samples were investigated in order to quantify the degree of bleaching. This approach involved the use of quartz OSL, K-feldspar infrared stimulated luminescence (IRSL) and post-IR IRSL (pIRIR) ages. The resulting data were then compared with radiocarbon ages. The quartz OSL signals were well-bleached for all the samples, and the feldspar pIRIR150 and pIRIR225 signals yielded reliable ages for the pre-Holocene deposits but overestimated ages for late Holocene deposits (input. Rapid deltaic progradation with high sedimentation rates over the last millennia, was revealed by the quartz OSL age results. This was supported by historical records for this section of the coastline. Episodic deposition around 700 years ago most likely triggered by frequent flooding events, was highlighted by the clustered OSL ages. While the sediment increment was 2.7 × 104 m3 a-1 for the period of ∼6-1 ka, this increased considerably to 9.1 × 106 m3 a-1 during the rapid progradation of the last millennium. The increase appears related to winter monsoon enhancement and human activity during the last 1000 years.

Kiglapait Feldspar States 5 to Review

Science.gov (United States)

Morse, S. A.

2017-12-01

The 1305 Ga Kiglapait Intrusion of coastal Labrador records the crystallization of troctolite through olivine gabbro to magnetite- and apatite-bearing rocks to monoclinic sanidine- mesoperthite-ferrosyenite below an inverted stratigraphy of a thin Upper Border Zone. The crystallization history was about 1 Ma. ¶The evolutionary history of Kiglapait feldspars in an 8.4 km thick magma chamber runs from plagioclase An70 at 5 kbar and 1250°C, cooling through to ferrosyenite with mesoperthite and two feldspars at 3 kbar and 1,000°C. The residual magma encountered the binodal solvus and finished crystallizing as an azeotrope with plagioclase (Or 21, An 15) and sanidine (Or 52, An 8) in liquid (Xor = 1/3; An 11). Cooling in the subsolidus brought the feldspars to compositions An15-Or 3, An0-Or 80-85 at 800-730°C. Metastable mesoperthite on the coherent solvus in various stages of late equilibration persists in the local assemblages. Arrested to complete feldspar symplectites suggest the local presence of a vapor phase. ¶Splits of the final Or-rich feldspar were found by mass spectrometry to have a dominant quantity of Rb and 87Sr/86Sr along with % amounts of Ba; in contrast, the plag fraction has very low Rb and 87Sr/86Sr. The estimated timing of the isotopic segregation was plausibly continuous with major-element fractionation or perhaps at the moment(s) of exsolution. ¶The cooling record of the solidified intrusion at 3 kbar is shown by 40Ar/39Ar data to have been rapid, reaching an ambient temperature near 240°C within the first 20 Ma, compared to the ambient country-rock temperature before intrusion of 350°C. The difference suggests a late uplift of the region after the Kiglapait magmatism. ¶Contributions from Y. Yu, T. Krogh, M. Hamilton, D. Lindsley, D. DePaolo, M. Jercinovic and S.R. Hart are especially acknowledged.

Thermo-optical properties of optically stimulated luminescence in feldspars

DEFF Research Database (Denmark)

Poolton, N.R.J.; Bøtter-Jensen, L.; Johnsen, O.

1995-01-01

Optically stimulated luminescence processes in feldspars are subject to competing thermal enhancement and quenching processes: this article describes the thermal enhancement effects for orthoclase, albite and plagioclase feldspars. It is demonstrated that certain lattice vibrational modes can be ...

Thermoluminescence of annealed and shock-loaded feldspar

International Nuclear Information System (INIS)

Hartmetz, C.P.

1988-01-01

Samples of oligoclase and bytownite were shock-loaded to a variety of pressures, and annealed for a variety of temperatures and times. The effect of Mrad doses of gamma-rays on oligoclase TL were also studied. After these treatments, thermoluminescence (TL) and X-ray diffraction (XRD) measurements were made to: (1) determine the effects of shock on terrestrial feldspar and compare with variations in the TL emission of ordinary chondrites (OCs); (2) determine if disordering in feldspar was responsible for any related changes in TL properties of OCs; (3) determine if the combined effect of shock plus annealing causes the changes in TL properties; (4) see if radiation damage from cosmic ray exposure plays a role in the TL variations; (5) examine the implications of this work to the thermal and shock histories of OCs. The lightly shock-loaded and annealed oligoclase samples have a dominant peak temperature of 120-140 C, identical to type 3.3-3.5 OCs. The heavily shocked samples dominant peak is at 230C, similar to type > 3.5 OCs . While the heavily annealed/disordered oligoclase samples have a peak at 280C, this peak is rarely observed in OCs. Radiation damage from Mrad doses of gamma-rays produced no change in peak temperature, but facilitated the shift to higher peak temperatures. The TL sensitivity of the shocked samples decreased by a factor of 25. Samples annealed at low temperatures (438-533C) showed a factor of 2 decrease in TL, but at the highest temperatures, the TL was a factor of 8 higher

Morphological evolution of dissolving feldspar particles with anisotropic surface kinetics and implications for dissolution rate normalization and grain size dependence: A kinetic modeling study

Science.gov (United States)

Zhang, Li; Lüttge, Andreas

2009-11-01

With previous two-dimensional (2D) simulations based on surface-specific feldspar dissolution succeeding in relating the macroscopic feldspar kinetics to the molecular-scale surface reactions of Si and Al atoms ( Zhang and Lüttge, 2008, 2009), we extended our modeling effort to three-dimensional (3D) feldspar particle dissolution simulations. Bearing on the same theoretical basis, the 3D feldspar particle dissolution simulations have verified the anisotropic surface kinetics observed in the 2D surface-specific simulations. The combined effect of saturation state, pH, and temperature on the surface kinetics anisotropy has been subsequently evaluated, found offering diverse options for morphological evolution of dissolving feldspar nanoparticles with varying grain sizes and starting shapes. Among the three primary faces on the simulated feldspar surface, the (1 0 0) face has the biggest dissolution rate across an extensively wide saturation state range and thus acquires a higher percentage of the surface area upon dissolution. The slowest dissolution occurs to either (0 0 1) or (0 1 0) faces depending on the bond energies of Si-(O)-Si ( ΦSi-O-Si/ kT) and Al-(O)-Si ( ΦAl-O-Si/ kT). When the ratio of ΦSi-O-Si/ kT to ΦAl-O-Si/ kT changes from 6:3 to 7:5, the dissolution rates of three primary faces change from the trend of (1 0 0) > (0 1 0) > (0 0 1) to the trend of (1 0 0) > (0 0 1) > (0 1 0). The rate difference between faces becomes more distinct and accordingly edge rounding becomes more significant. Feldspar nanoparticles also experience an increasing degree of edge rounding from far-from-equilibrium to close-to-equilibrium. Furthermore, we assessed the connection between the continuous morphological modification and the variation in the bulk dissolution rate during the dissolution of a single feldspar particle. Different normalization treatments equivalent to the commonly used mass, cube assumption, sphere assumption, geometric surface area, and reactive

Luminescence excitation characteristics of Ca-, Na- and K-aluminosilicates (feldspars), in the stimulation range 20-500 eV: optical detection of XAS

CERN Document Server

Poolton, N R J; Quinn, F M; Pantos, E; Andersen, C E; Bøtter-Jensen, L; Johnsen, O; Murray, A S

2003-01-01

We demonstrate that the visible/UV luminescence from common feldspar crystals (NaAlSi sub 3 O sub 8 , KAlSi sub 3 O sub 8 and CaAl sub 2 Si sub 2 O sub 8) can be used to detect detailed L-edge and associated near-edge absorption structure of the main constituent atoms (Ca, K, Na, Al, Si), when exciting in the energy range 20-500 eV. Comparisons of the spectral features are drawn with similar measurements made on the associated materials SiO sub 2 , Al sub 2 O sub 3 and CaCO sub 3. The potential for using optically detected x-ray absorption spectroscopy as a method for identifying the luminescent components of mixed mineral samples is considered.

Formation of halloysite from feldspar: Low temperature, artificial weathering versus natural weathering

Science.gov (United States)

Parham, Walter E.

1969-01-01

Weathering products formed on surfaces of both potassium and plagioclase feldspar (An70), which were continuously leached in a Soxhlet extraction apparatus for 140 days with 7.21 of distilled water per day at a temperature of approximately 78°C, are morphologically identical to natural products developed on potassium feldspars weathered under conditions of good drainage in the humid tropics. The new products, which first appear as tiny bumps on the feldspar surface, start to develop mainly at exposed edges but also at apparently random sites on flat cleavage surfaces. As weathering continues, the bumps grow outward from the feldspar surface to form tapered projections, which then develop into wide-based thin films or sheets. The thin sheets of many projections merge laterally to form one continuous flame-shaped sheet. The sheets formed on potassium feldspars may then roll to form tubes that are inclined at a high angle to the feldspar surface. Etch pits of triangular outline on the artificially weathered potassium feldspars serve as sites for development of continuous, non-rolled, hollow tubes. It is inferred from its morphology that this weathering product is halloysite or its primitive form. The product of naturally weathered potassium feldspars is halloysite . 4H2O.The flame-shaped films or sheets formed on artificially weathered plagioclase feldspar do not develop into hollow tubes, but instead give rise to a platy mineral that is most probably boehmite. These plates form within the flame-shaped films, and with continued weathering are released as the film deteriorates. There is no indication from this experiment that platy pseudohexagonal kaolinite forms from any of these minerals under the initial stage of weathering.

Na-rich feldspar as a luminescence dosimeter in infrared stimulated luminescence (IRSL) dating

DEFF Research Database (Denmark)

Sohbati, Reza; Murray, Andrew; Jain, Mayank

2013-01-01

on geological origin and erosion history, but the dosimetry of K-rich feldspar grains extracted from rocks is complicated because the internal dose rate is very dependent on the original feldspar grain size. The in situ grain size information is lost during the crushing process used to separate the grains...... settings for which independent age control is available. The blue and yellow luminescence emissions are measured for IR stimulation at 50 °C (IR50), and post-IR IR stimulation at 290 °C (pIRIR290). Thermal stability experiments imply that the corresponding signals in both emissions have comparable thermal...... stabilities and that all signals have similar recombination kinetics and are thermally stable over geological timescales. The IR50 doses measured using blue and yellow emissions are similar to or lower than quartz doses while pIRIR290 blue doses are higher than those from yellow emission and quartz doses...

Identifying well-bleached quartz using the different bleaching rates of quartz and feldspar luminescence signals

DEFF Research Database (Denmark)

Murray, A.S.; Thomsen, Kristina Jørkov; Masuda, N.

2012-01-01

When dating older sedimentary deposits using quartz, there are no unambiguous methods for identifying the presence of incomplete bleaching. Current statistical analysis of dose distributions depends entirely on the assumption that incomplete bleaching and mixing are the main causes of any excess...... dispersion in the distribution; the only existing way to test this assumption is using independent age control. Here we suggest a new approach to this question, based on the differential bleaching rates of quartz and feldspar luminescence signals. We first present data that confirm the differences...... in relative bleaching rates of quartz optically stimulated luminescence (OSL) and feldspar luminescence stimulated at 50 °C by infrared light (IR50) and feldspar luminescence stimulated at 290 °C by infrared light after a stimulation at 50 °C (pIRIR290), and use recently deposited samples to determine...

Understanding optically stimulated charge movement in quartz and feldspar using time-resolved measurements

International Nuclear Information System (INIS)

Ankjaergaard, C.

2010-02-01

through the shallow traps. The results from feldspars show the relative roles of an IR excited state (IR resonance), band tails and the conduction band in determining charge transport. It is suggested that unlike quartz, the excited state lifetime does not play an important role in our measurements. Finally, it is shown that one of these routes favors production if a least fading signal (due to quantum mechanical tunnelling) in feldspars. Although, results are only presented for some quartz and feldspar samples, they were found to be very similar within the each group during the course of this work. (Author)

Understanding optically stimulated charge movement in quartz and feldspar using time-resolved measurements

Energy Technology Data Exchange (ETDEWEB)

Ankjaergaard, C.

2010-02-15

through the shallow traps. The results from feldspars show the relative roles of an IR excited state (IR resonance), band tails and the conduction band in determining charge transport. It is suggested that unlike quartz, the excited state lifetime does not play an important role in our measurements. Finally, it is shown that one of these routes favors production if a least fading signal (due to quantum mechanical tunnelling) in feldspars. Although, results are only presented for some quartz and feldspar samples, they were found to be very similar within the each group during the course of this work. (Author)

Beneficiation of feldspar ore for application in the ceramic industry: Influence of composition on the physical characteristics

OpenAIRE

Gaied, M.E.; Gallala, W.

2015-01-01

In this study, physical and physicochemical experiments were carried out to improve the quality of feldspar ore in Sidi Aïch massive, located in the Gafsa region of south-western Tunisia. After determination of the mineralogical and the chemical composition, flotation methods were applied. In this study, non-hydrofluoric acid flotation methods used in feldspar-quartz separation were compared with each other and with the conventional HF/amine method. The results showed that conventional HF/ami...

Increase in Ice Nucleation Efficiency of Feldspars, Kaolinite and Mica in Dilute NH3 and NH4+-containing Solutions

Science.gov (United States)

Kumar, A.; Marcolli, C.; Luo, B.; Krieger, U. K.; Peter, T.

2017-12-01

Semivolatile species present in the atmosphere are prone to adhere to mineral dust particle surfaces during long range transport, and could potentially change the particle surface properties and its ice nucleation (IN) efficiency. Immersion freezing experiments were performed with microcline (K-feldspar), known to be highly IN active, suspended in aqueous solutions of ammonia, (NH4)2SO4, NH4HSO4, NH4NO3, NH4Cl, Na2SO4, H2SO4, K2SO4 and KCl to investigate the effect of solutes on the IN efficiency. Freezing of emulsified droplets investigated with a differential scanning calorimeter (DSC) showed that the heterogeneous ice nucleation temperatures deviate from the water activity-based IN theory, describing heterogeneous ice nucleation temperatures as a function of solution water activity by a constant offset with respect to the ice melting point curve (Zobrist et al. 2008). IN temperatures enhanced up to 4.5 K were observed for very dilute NH3 and NH4+-containing solutions while a decrease was observed as the concentration was further increased. For all solutes with cations other than NH4+, the IN efficiency decreased. An increase of the IN efficiency in very dilute NH3 and NH4+-containing solutions followed by a decrease with increasing concentration was also observed for sanidine (K-feldspar) and andesine (Na/Ca-feldspar). This is an important indication towards specific chemical interactions between solutes and the feldspar surface which is not captured by the water activity-based IN theory. A similar trend is present but less pronounced in case of kaolinite and mica, while quartz is barely affected. We hypothesize that the hydrogen bonding of NH3 molecules with surface -OH groups could be the reason for the enhanced freezing temperatures in dilute ammonia and ammonium containing solutions as they could form an ice-like overlayer providing hydrogen bonding groups for ice to nucleate on top of it. This implies to possibilities of enhanced IN efficiency, especially

Deformation of quartz and feldspar at mid-crustal depths in an extensional normal fault (Viveiro Fault, NW Spain)

Science.gov (United States)

López-Sánchez, M. A.; Llana-Fúnez, S.; Marcos, A.; Martínez, F. J.

2012-04-01

Metamorphic reactions, deformation mechanism and chemical changes during mylonitization and ultramylonitization of granite affected by a crustal-scale shear zone are investigated using microstructural observations and quantitative analysis. The Vivero Fault (VF) is a large extensional shear zone (>140Km) in NW of Iberia that follows the main Variscan trend dipping 60° toward the West. The movement accumulated during its tectonic history affects the major lithostratigraphic sequence of Palaeozoic and Neoproterozoic rocks and the metamorphic facies developed during Variscan orogenesis. Staurolite, and locally, andalucite plus biotite grew in the hangingwall during the development of VF, overprinted the previous regional Variscan greenschist facies metamorphism. Andalusite growth took place during the intrusion of syntectonic granitic bodies, such as the deformed granite studied here. The Penedo Gordo granite is coarse-grained two-mica biotite-rich granite intruding the VF and its hangingwall. This granite developed a localized deformation consisting of a set of narrow zones (mm to metric scales) heterogeneously distributed subsequently to its intrusion. Based on pseudosections for representative hangingwall pelites hosting the granite and the inferred metamorphic evolution, the shear zone that outcrops at present-day erosion surface was previously active at 14,7-17 km depth (390-450 MPa). Temperature estimates during deformation reach at least the range 500-600° C, implying a local gradient of 35±6°C/km. Microstructures in the mylonites are characterized by bulging (BLG) to subgrain rotation (SGR) recristallization in quartz with the increasing of deformation. Albitisation, flame-perthite and tartan twining are common in K-feldspar at the early stage of deformation. The inferred dominant deformation mechanisms are: i) intracrystalline plasticity in quartz, ii) cataclasis with syntectonic crystallisation of very fine albite-oligoclase and micas in K-feldspar, and

Rare earth element geochemistry of feldspars: examples from Fe-oxide Cu-Au systems in the Olympic Cu-Au Province, South Australia

Science.gov (United States)

Kontonikas-Charos, Alkis; Ciobanu, Cristiana L.; Cook, Nigel J.; Ehrig, Kathy; Krneta, Sasha; Kamenetsky, Vadim S.

2018-04-01

Rare earth element (REE) fractionation trends in feldspars are reported from Olympic Dam (including Wirrda Well and Phillip's Ridge) and Cape Donington (Port Lincoln), for comparison with two other igneous-hydrothermal terranes within the eastern Gawler Craton: Moonta-Wallaroo and Hillside. The case studies were selected as they represent 1590 Ma Hiltaba Suite and/or 1845 - 1810 Ma Donington Suite granites, and, aside from Cape Donington, are associated with Mesoproterozoic iron-oxide copper gold (IOCG)-type mineralization. Both plagioclase and alkali feldspar were analyzed within selected samples with the purpose of constraining and linking changes in REE concentrations and fractionation trends in feldspars to local and whole-rock textures and geochemistry. Two unique, reproducible fractionation trends were obtained for igneous plagioclase and alkali feldspars, distinguished from one another by light rare earth element enrichment, Eu-anomalies and degrees of fractionation (e.g. La/Lu slopes). Results for hydrothermal albite and K-feldspar indicate that REE concentrations and fractionation trends are generally inherited from igneous predecessors, however in some instances, significant amounts of REE appear to have been lost to the fluid. These results may have critical implications for the formation of world-class IOCG systems, in which widespread alkali metasomatism plays a key role by altering the physical and chemical properties of the host rocks during early stages of IOCG formation, as well as trapping trace elements (including REE).

57Fe Moessbauer spectroscopy study of phlogopite megacrysts from an evolved carbonatitic kimberlite in the northeastern Oman Mountains

International Nuclear Information System (INIS)

Al-Rawas, A. D.; Nasir, S.; Gismelseed, A. M.

2008-01-01

The Fe oxidation degree determined by 57 Fe Moessbauer spectroscopy and microprobe was used to characterize fresh and altered phlogopite megacrysts from an evolved carbonatitic kimberlite from northeastern Oman. The Quadrupole splitting (QS) varies between 2.19 and 2.48 mm/s (Fe 2+ ) in the fresh phlogopite samples and between 2.40 and 2.47 mm/s in the altered phlogopite samples. The quadrupole splitting of the Fe 3+ doublets varies between 0.66 and 0.85 mm/s in the fresh samples. The altered phlogopite samples show three Fe 3+ doublets; the first show a quadrupole splitting between 0.97 and 1.13, the second quadrupole splitting varies between 0.24 and 0.46 mm/s and the third varies between - 0.23 and - 0.35 mm/s. The phlogopite was observed to have an average Fe 3+ /Fe total of 35% to 37%, and corresponds to fresh phlogopite. The second one results from the alteration of the first type, and the Fe 3+ /Fe total ranges between 40% and 57%. Tetrahedral Fe 3+ ions were confirmed in the altered phlogopite samples. Quantitative Fe site distributions can be obtained from room-temperature Moessbauer data if the different recoilless factors for octahedral Fe 2+ and tetrahedral Fe 3+ are considered. The observed isomer shifts are consistent with Moessbauer temperatures of 330 K, reported in the literature for tetrahedral and octahedral Fe 3+ and Fe 2+ in phlogopite. The results are compared to those obtained for natural and synthetic phlogopite from worldwide.

Bio-beneficiation of kaolin and feldspar and its effect on fired

Indian Academy of Sciences (India)

Presence of iron compounds as impurities in kaolin and feldspar, impart reddish colour to ceramic products manufactured using these minerals. The quality of kaolin and feldspar was enriched mainly through iron removal by biological methods. Bacteria isolated from kaolin of Indian origin were used for bioleaching.

New insights into the oleate flotation response of feldspar particles of different sizes: Anisotropic adsorption model.

Science.gov (United States)

Xu, Longhua; Tian, Jia; Wu, Houqin; Deng, Wei; Yang, Yaohui; Sun, Wei; Gao, Zhiyong; Hu, Yuehua

2017-11-01

The anisotropic adsorption of sodium oleate (NaOL) on feldspar surfaces was investigated to elucidate the different flotation properties of feldspar particles of four different size ranges. Microflotation experiments showed that the feldspar flotation recovery of particles with sizes spanning different ranges decreased in the order 0-19>19-38>45-75>38-45μm. Zeta potential and FTIR measurements showed that NaOL was chemically adsorbed on the Al sites of the feldspar surface. The anisotropic surface energies and broken bond densities estimated by density functional theory calculations showed that, although feldspar mostly exposed (010) and (001) surfaces, only the (001) surfaces contained the Al sites needed for NaOL adsorption. The interaction energies calculated by molecular dynamics simulations confirmed the more favorable NaOL adsorption on (001) than (010) surfaces, which may represent the main cause for the anisotropic NaOL adsorption on feldspar particles of different sizes. SEM measurements showed that the main exposed surfaces on coarse and fine feldspar particles were the side (010) and basal (001) ones, respectively. A higher fraction of Al-rich (001) surfaces is exposed on fine feldspar particles, resulting in better floatability compared with coarse particles. XPS and adsorption measurements confirmed that the Al content on the feldspar surface varied with the particle size, explaining the different NaOL flotation of feldspar particles of different sizes. Therefore, the present results suggest that coarsely ground ore should be used for the separation of feldspar gangue minerals. Further improvements in the flotation separation of feldspar from associated valuable minerals can be achieved through selective comminution or grinding processes favoring the exposure of (010) surfaces. Copyright © 2017 Elsevier Inc. All rights reserved.

Paleodosimetrical properties of sodium alkali feldspars and problems of luminescence dating of sediments

International Nuclear Information System (INIS)

Huett, Galina; Jaek, Ivar

1996-01-01

Emission spectra of natural alkali feldspars extracted from sediments are studied using a CCD-camera based high sensitivity spectrometer. Applying a semiconductor laser (860± 1 nm), two dominant emission bands, blue (410 nm) and orange (570 nm), are revealed in infrared optically stimulated luminescence (IROSL) spectra for the most of the sediments from Scandinavian sections. Luminescence and dosimetric al properties of the hole traps, the induced orange emission band typical of sodium alkali feldspars are studied. As a result, high light bleach ability but low stability of the dosimetric al information lit sodium alkali feldspars are established. Problems of luminescence dating of sediments based on the mixture of potassium-sodium alkali feldspars are discussed. (author)

Optically stimulated luminescence characteristics of natural and doped quartz and alkali feldspars

Energy Technology Data Exchange (ETDEWEB)

Huett, G.; Jaek, I.; Brodski, L. [Institute of Geology at Tallinn Technical University, Tallinn (Estonia); Vasilchenko, V. [Institute of Experimental Physics and Technology of Tartu University, Tartu (Estonia)

1999-05-01

Natural alkali feldspars and quartz were doped by Tl and Cu by thermodiffusion and electrodiffusion technology. As a result of doping, intensive UV emission bands were created. The OSL stimulation spectra of irradiated natural and doped quartz and alkali feldspars were measured in the span of 400-1300 nm using UV emission of Tl at 280 nm and of Cu at 380 nm. One-trap centre conception was confirmed for high-temperature palaeodosimetrical TL peaks and OSL stimulation spectrum bands: for alkali feldspars at 880 and 420 nm and visible region of the spectrum for quartz. A thermooptical mechanism of the optical depopulation of the corresponding trap is confirmed in alkali feldspars, but there is no evidence for processes of this kind in quartz. An analogy between the physical background of OSL properties of both minerals is discussed.

Optically stimulated luminescence characteristics of natural and doped quartz and alkali feldspars

International Nuclear Information System (INIS)

Huett, G.; Jaek, I.; Brodski, L.; Vasilchenko, V.

1999-01-01

Natural alkali feldspars and quartz were doped by Tl and Cu by thermodiffusion and electrodiffusion technology. As a result of doping, intensive UV emission bands were created. The OSL stimulation spectra of irradiated natural and doped quartz and alkali feldspars were measured in the span of 400-1300 nm using UV emission of Tl at 280 nm and of Cu at 380 nm. One-trap centre conception was confirmed for high-temperature palaeodosimetrical TL peaks and OSL stimulation spectrum bands: for alkali feldspars at 880 and 420 nm and visible region of the spectrum for quartz. A thermooptical mechanism of the optical depopulation of the corresponding trap is confirmed in alkali feldspars, but there is no evidence for processes of this kind in quartz. An analogy between the physical background of OSL properties of both minerals is discussed

Petrology and geochemistry of the Los Cuartos granite, Tafi del Valle, Tucuman, northwest of Argentina: its integration to the regional magmatic layout; Petrologia y geoquimica del granito Los Cuartos, Tafi del Valle, Tucuman, noroeste de Argentina: integracion al esquema magmatico regional

Energy Technology Data Exchange (ETDEWEB)

Lopez, J.P.; Bellos, L.I.

2010-07-01

Los Cuartos Granite crops out on the western flank of the Cumbres Calchaquies, east of Tafi del Valle, Tucuman Province, Argentina. It has a granitic to granodioritic composition, of two micas, being biotite dominant. The granite is medium grained and inequigranular, with rare K-feldspar megacrysts. It contains host-rock xenoliths with different degrees of assimilation. The granite intrusion produced contact metamorphism in the surrounding basement, with development of andalucite porphyroblasts and poikiloblastic biotite. The granite is calk-alkaline and peraluminous, and is K- and P-rich and Ca- and Napoor compared to other granitoids of the region. The pluton shows late-tectonic features with regard to the regional deformation. The granite possibly intruded during the Ordovician (Famatinian Cycle) and its emplacement was structurally controlled by the Tafi Megafracture. Los Cuartos Granite and other intrusive bodies of the region share similar petrographical, geochemical, structural and geochronological characteristics. (Author).

Laboratory fading rates of various luminescence signals from feldspar-rich sediment extracts

DEFF Research Database (Denmark)

Thomsen, Kristina Jørkov; Murray, A.S.; Jain, Mayank

2008-01-01

Feldspar as a retrospective dosimeter is receiving more and more attention because of its useful luminescence properties; in particular the dose response curve extends to significantly higher doses than quartz. However, feldspars have one major disadvantage; both the thermoluminescence (TL...

Quantitative analysis of time-resolved infrared stimulated luminescence in feldspars

DEFF Research Database (Denmark)

Pagonis, Vasilis; Ankjærgaard, Christina; Jain, Mayank

2016-01-01

Time-resolved infrared-stimulated luminescence (TR-IRSL) from feldspar samples is of importance in the field of luminescence dating, since it provides information on the luminescence mechanism in these materials. In this paper we present new analytical equations which can be used to analyze TR-IR....... The equations are applied to experimental TR-IRSL data of natural feldspars, and good agreement is found between experimental and modeling results....

Luminescence characterization of a sodium rich feldspar

International Nuclear Information System (INIS)

Correcher, V.; Sanchez M, L.; Garcia G, J.; Rivera, T.

2006-01-01

This paper reports on the radioluminescence (RL) and thermoluminescence (TL) properties of a sodium rich feldspar ((Na,K)[AlSi 3 O 8 ]) with a mean molecular composition of orthoclase (Or) and albite (Ab) of Or 1 Ab 99 . Despite the complexity of the luminescence signals of the sample, it is possible to determine six different emission bands at about 300, 380, 420, 460, 550 and 680 nm. The 300 nm emission can be associated to structural defects related to the recombination process in which the Na + ion diffusion-limited is involved. The UV-blue emission band at (i) 380 nm is characteristic of mineral phases containing SiO 4 tetrahedral and could be related to intrinsic defects in the lattice, (ii) the 420 nm band could be associated to the presence of Cu (II) ions placed next to the hole traps or the recombination on a centre formed from a hole-oxygen atom adjacent to two Al atoms (Al-O-Al) and (iii) the 460 nm waveband could be due to the presence of Ti 4+ . The green and red emissions are respectively associated to the presence of Mn 2+ and Fe 3+ ions. The ratio between the relative intensities, peaked at 290 (the more intense waveband) and 550 nm is about 10:1 in both TL and RL; this fact indicates that the efficiency of recombination centres does no changes regardless on the type of the process. (Author)

OSL-thermochronometry of feldspar from the KTB borehole, Germany

DEFF Research Database (Denmark)

Guralnik, Benny; Jain, Mayank; Herman, Frédéric

2015-01-01

a new thermochronometer based on the infrared stimulated luminescence (IRSL) from feldspar, and validate the extrapolation of its response to artificial radiation and heat in the laboratory to natural environmental conditions. Specifically, we present a new detailed Na-feldspar IRSL thermochronology...... the current geothermal gradient, or (ii) inverted into a geothermal palaeogradient of 29±2 °C km−1, integrating natural thermal conditions over the last ∼65 ka. The demonstrated ability to invert a depth–luminescence dataset into a meaningful geothermal palaeogradient opens new venues for reconstructing...

Iron removal on feldspar by using Averrhoa bilimbii as bioleaching agent

Science.gov (United States)

Amin, Muhammad; Aji, Bramantyo B.; Supriyatna, Yayat Iman; Bahfie, Fathan

2017-01-01

Investigation of Averrhoa bilimbii as bioleaching agent was carried out. Parameters of leaching duration, acid concentration, and temperature were performed in iron removal process. Feldspar with sized 149 µm was diluted in 30 ml acid solution in order to reduce its iron content. The experimental results showed a good technical feasibility of the process which iron oxide content of feldspar was decreased from 2.24% to 0.29%. The lowest iron concentration remained was obtained after 5 hours of leaching treatment at 60 °C, and concentrated (100 vol%) Averrhoa bilimbii extract as bioleaching agent. SEM characterizations were carried out on the feldspar before and after the leaching treatment. The result shows that there were no significant effect of leaching process on the ore morphology.

OSL and IRSL characteristics of quartz and feldspar from southern California, USA

International Nuclear Information System (INIS)

Lawson, Michael J.; Roder, Belinda J.; Stang, Dallon M.; Rhodes, Edward J.

2012-01-01

Southern California comprises of a wide range of diverse landscapes and environments, from high mountains with glacial and periglacial sediments to deserts with large sand dunes, extensive alluvial fans and ephemeral playas. Highly active tectonic processes has exposed ancient (c. 2 Ga) plutonic and metamorphic basement from deep within the crust, while similar Palaeozoic, Mesozoic and Cenozoic rocks are also common. A rich array of volcanic lithologies extending into the late Quaternary complement many thick sedimentary sequences that formed in equally diverse ancient environments typical of an accreting active continental margin. In some locations, notably in the Coachella Valley close to Palm Springs and the Salton Sea, low OSL sensitivity and poor characteristics restrict the application of the quartz SAR protocol to date late Pleistocene and Holocene fluvial sediments. In other locations such as the Malibu coastline, high sensitivity of the quartz OSL signal is observed, despite local source rocks being dominated by volcanic lithologies. Problems of poor quartz characteristics, along with uncertainty in predicting quartz OSL behavior for future dating campaigns poses a significant problem for projects, in particular for neotectonic contexts. While K-feldspar has been used extensively to date eolian and fluvial sediments in southern California, little information regarding signal stability is available. We explore the characteristics of both quartz and feldspar sub-samples from eolian, fluvial, lacustrine environments, in order to help develop mineral selection criteria for optical dating applications and clarify these issues. The importance of radiation quenching in quartz grains recently eroded from bedrock and the role of fires in enhancing OSL sensitivity are considered. The relative bleachability of quartz and feldspar fractions, along with thermal stability considerations is discussed. A simple test for quartz OSL signal contamination based on thermal

Feldspar basalts in lunar soil and the nature of the lunar continents

Science.gov (United States)

Reid, A. M.; Ridley, W. I.; Harmon, R. S.; Warner, J.; Brett, R.; Jakes, P.; Brown, R. W.

1974-01-01

It is found that 25% on the Apollo-14 glasses have the same composition as the glasses in two samples taken from the Luna-16 column. The compositions are equivalent to feldspar basalt and anorthosite gabbro, and are similar to the feldspar basalts identified from Surveyor-7 analysis for lunar continents.

Structure-dependent interactions between alkali feldspars and organic compounds: implications for reactions in geologic carbon sequestration.

Science.gov (United States)

Yang, Yi; Min, Yujia; Jun, Young-Shin

2013-01-02

Organic compounds in deep saline aquifers may change supercritical CO(2) (scCO(2))-induced geochemical processes by attacking specific components in a mineral's crystal structure. Here we investigate effects of acetate and oxalate on alkali feldspar-brine interactions in a simulated geologic carbon sequestration (GCS) environment at 100 atm of CO(2) and 90 °C. We show that both organics enhance the net extent of feldspar's dissolution, with oxalate showing a more prominent effect than acetate. Further, we demonstrate that the increased reactivity of Al-O-Si linkages due to the presence of oxalate results in the promotion of both Al and Si release from feldspars. As a consequence, the degree of Al-Si order may affect the effect of oxalate on feldspar dissolution: a promotion of ~500% in terms of cumulative Si concentration was observed after 75 h of dissolution for sanidine (a highly disordered feldspar) owing to oxalate, while the corresponding increase for albite (a highly ordered feldspar) was ~90%. These results provide new insights into the dependence of feldspar dissolution kinetics on the crystallographic properties of the mineral under GCS conditions.

Stoneware tile manufacturing using rice straw ash as feldspar replacement

International Nuclear Information System (INIS)

Alvaro Guzman, A.; John Torres, L.; Martha Cedeno, V.; Silvio Delvasto, A.; Vicente Amigo, B.; Enrique Sanchez, V.

2013-01-01

In this research are presented the results of using rice straw ash (RSA) in low proportions as substitute of feldspar for manufacturing stoneware tiles. Specimens of semidry triaxial mixtures, where feldspar was substituted for different percentages (25 % and 50 %) of RSA, were prepared by uniaxial pressing, followed by drying and sintering. Physical and mechanical properties of sintered bodies were evaluated. Porcelain stoneware tile specimens C0 and CF25 reached bending strength and water absorption values were in accordance with standard ISO 13006 (Annex G, BIa) ( ≥ 35 MPa and ≤ 0.5 %, respectively). However, in porcelain stoneware tile specimens CF50 due to bloating phenomenon was not possible obtain commercial tiles in accordance with standard ISO 13006. By using Scanning Electron Microscopy (SEM) needles of primary and secondary mullite were identified in a vitreous phase; and by using X-Ray Diffraction (XRD) mullite and quartz phases were identified. It was concluded that feldspar can be substituted positively by RSA in stoneware tile pastes. (Author)

Probing luminescence centers in Na rich feldspar

DEFF Research Database (Denmark)

Prasad, Amit Kumar; Lapp, Torben; Kook, Myung Ho

2016-01-01

our understanding of the luminescence mechanisms and recombination sites, in a sample of Na rich plagioclase feldspar (oligoclase). Both the UV and violet–blue emissions show resonant excitations arising from a distribution of energy levels. We propose, contrary to the general understanding...

Kinetics of infrared stimulated luminescence from feldspars

DEFF Research Database (Denmark)

Jain, Mayank; Sohbati, Reza; Guralnik, Benny

2015-01-01

thermal and optical, of the infrared stimulated luminescence signal from feldspar. Based on the application of this model, it is concluded that different infra-red stimulated luminescence emissions (UV, blue, yellow and far-red) follow the same kinetics, and, therefore, involve participation of the same...

OSL, TL and IRSL emission spectra of sedimentary quartz and feldspar samples

International Nuclear Information System (INIS)

Lomax, Johanna; Mittelstraß, Dirk; Kreutzer, Sebastian; Fuchs, Markus

2015-01-01

This contribution presents a variety of different luminescence emission spectra from sedimentary feldspar and quartz samples under various stimulation modes. These are green stimulated quartz (OSL-) spectra, quartz TL spectra, feldspar IRSL and post-IR IRSL spectra. A focus was set at recording OSL and IRSL spectra at elevated stimulation temperatures such as routinely applied in luminescence dating. This was to test whether optical stimulation at elevated temperatures results in a shift of emission peaks. For OSL emissions of quartz, this has so far not been tested. In case of feldspar emissions, post-IR IRSL conditions, hence IRSL emissions at a low temperature, directly followed by high temperature post-IRSL emissions, are explicitly investigated. All spectra were recorded using a new system incorporated into a Lexsyg luminescence reader. Thus, this study, besides presenting new spectral data, also serves as a feasibility study for this new device. It is shown that (a) the new device is capable of automatically measuring different sorts of spectra, also at elevated temperatures, (b) known thermally and optically stimulated peak emissions of quartz and feldspar are confirmed, (c) obtained IRSL and OSL spectra indicate that there is no significant relation between peak emission and stimulation temperature. - Highlights: • We have measured OSL, IRSL and TL emission spectra of sedimentary quartz and feldspar samples. • Spectral analyses were performed at elevated stimulation temperatures. • Emission spectra show very little variation with stimulation temperatures.

Further investigations into pulsed optically stimulated luminescence from feldspars using blue and green light

DEFF Research Database (Denmark)

Ankjærgaard, Christina; Jain, Mayank; Kalchgruber, R.

2009-01-01

The purpose of this paper is to investigate characteristics of luminescence signals resulting from pulsed optical stimulation of feldspars and thereby to understand the underlying processes giving rise to the signal. Fourteen different feldspar specimens were investigated using time-resolved opti......The purpose of this paper is to investigate characteristics of luminescence signals resulting from pulsed optical stimulation of feldspars and thereby to understand the underlying processes giving rise to the signal. Fourteen different feldspar specimens were investigated using time...... suggests that the TR-OSL signal decay is governed by the recombination process and not by the excited state lifetime. Furthermore data from the TR-OSL signal dependence on stimulation time and preheat temperature suggest that the recombination process may not be a sum of exponentials, although the model...... cannot be rejected definitively....

Questioning the Sedimentary Paradigm for Granites

Science.gov (United States)

Glazner, A. F.; Bartley, J. M.; Coleman, D. S.; Boudreau, A.; Walker, J. D.

2007-12-01

A critical question regarding volcano-pluton links is whether plutons are samples of magma that passed through on its way to eruption, or residues left behind after volcanic rocks were extracted. A persistent theme of recent work on granites sensu lato is that many are sedimentary accumulations of crystals that lost significant volumes of magmatic liquid. This view is based on observations of structures that clearly seem to reflect deposition on a magma chamber floor (e.g., flows of chilled mafic magma into silicic magma) and on the inference that many other structures, such as modal layering, truncated layering, and crystal accumulations, reflect crystal sedimentation on such chamber floors. There are significant physical and geochemical reasons to question this view, based on observations in the Sierra Nevada of California and similar results from other batholiths. First, few granites show the enrichments in Ba, Sr, and relative Eu that feldspar accumulation should produce. Second, sedimentary features such as graded bedding and cross-bedding form in highly turbulent flows, but turbulence is unachievable in viscous silicic liquids, where velocities on the order of 104 m/s would be required to induce turbulence in a liquid with η=104 Pa s. Third, tabular modally layered domains commonly cut surrounding modal layering on both sides, and orientations of modal layering and of the troughs of "ladder dikes" commonly scatter widely within hectare-sized areas; it is difficult to reconcile these features with gravity-driven settling. Fourth, accumulations of K-feldspar megacrysts are typically inferred to be depositional, but this is precluded by crystallization of most K- feldspar after rheologic lock-up occurs. Finally, accumulations of K-feldspar and hornblende are typically packed too tightly to be depositional. With analogy to layered mafic intrusions, many features attributed to crystal sedimentation in granites may be better explained by crystal aging and other in

Re ‘Luminescence dating of K-feldspar from sediments: a protocol without anomalous fading correction’ by Bo Li and Sheng-Hua Li

DEFF Research Database (Denmark)

Thomsen, Kristina Jørkov; Murray, Andrew; Jain, Mayank

2012-01-01

Have recently proposed a new measurement procedure (MET-pIRIR) for luminescence dating using feldspar; they argue that this procedure reduces anomalous fading to negligible levels, and that it is a significant improvement over existing protocols (pIRIR290). Here we compare the measured equivalent...

Application of pulsed OSL to the separation of the luminescence components from a mixed quartz/feldspar sample

International Nuclear Information System (INIS)

Denby, P.M.; Botter-Jensen, L.; Murray, A.S.; Thomsen, K.J.; Moska, P.

2006-01-01

It is known that the pulsed optically stimulated luminescence (OSL) characteristics of quartz and feldspars are very different. These differences can be used to preferentially discriminate against the feldspar signal in mixed quartz-bar feldspar mineral assemblages, or in separated quartz contaminated with a feldspar signal. We have developed instrumentation for the study of high-speed pulse stimulated OSL. Our system uses the standard blue/IR LED stimulation unit of a Riso reader (allowing stimulation pulses down to 1-2μs duration) and can thus be applied to the routine analysis of samples. Using this stimulation source, and high-speed photon timing, the OSL yield can be monitored throughout the pulsing cycle and subsequent OSL decay. It is found that the total photon yield per unit stimulation power in pulsed mode is, for quartz, twice and, for feldspar, nearly four times, that in continuous wave mode. Observation of this OSL signal, between stimulation pulses, is seen to be characteristic of the mineral being examined, and has been used to preferentially discriminate against feldspar contamination in a mixed quartz/feldspar sample. Simple implementation of this technique by gating the counting period, so that counts are only accumulated during a windowed period, reduces the feldspar signal to 1.6% of its original value relative to that of the quartz

Assessment of the potential hazard represented by natural raw materials containing mineral fibres -The case of the feldspar from Orani, Sardinia (Italy)

Czech Academy of Sciences Publication Activity Database

Gualtieri, A. F.; Gandolfi, N. B.; Pollastri, S.; Rinaldi, R.; Sala, O.; Martinelli, G.; Bacci, T.; Paoli, F.; Viani, Alberto; Vigliaturo, R.

2018-01-01

Roč. 350, May (2018), s. 76-87 ISSN 0304-3894 R&D Projects: GA MŠk(CZ) LO1219 Keywords : feldspar * tremolite * Rietveld * SEM * EMPA Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Mineralogy Impact factor: 6.065, year: 2016 https://www.sciencedirect.com/science/article/pii/S0304389418300888

Optimising the separation of quartz and feldspar optically stimulated luminescence using pulsed excitation

International Nuclear Information System (INIS)

Ankjaergaard, C.; Jain, M.; Thomsen, K.J.; Murray, A.S.

2010-01-01

In luminescence dating, the two most commonly used natural minerals, quartz and feldspar, are exposed to different dose rates in the natural environment, and so record different doses. The luminescence signals also have different stabilities. For accurate dosimetry, the signals from these two minerals must be separated, either by physical separation of the mineral grains, or by instrumental separation of the luminescence signals. The luminescence signals from quartz and feldspar have different luminescence lifetimes under pulsed optical stimulation. This difference in lifetime can be used to discriminate between the two signals from a mixed quartz-feldspar sample. The purpose of this study is to identify optimum measurement conditions for the best separation of quartz OSL from that of feldspar in a mixed sample using pulsed stimulation and time-resolved OSL. We integrate the signal from 5 μs after the LEDs are switched off until just before the LEDs are switched on again, with the pulse on-time equal to the pulse off-time of 50 μs. By using only the initial interval of the pulsed OSL decay curve (equivalent to 0.2 s of CW-OSL using blue light at 50 mW cm -2 ) we find that the quartz to feldspar pulsed OSL intensity ratio is at a maximum. By using these parameters with an additional infrared (IR) stimulation at 175 o C before measurement (to further reduce the feldspar signal intensity), we obtain a factor of 25 enhancement in signal separation compared to that from a conventional prior-IR CW measurement. This ratio can be further improved if the counting window in the pulse off-time is restricted to detect between 20 and 50 μs instead of the entire off-period.

An evaluation of the residence duration of megacrysts in alkaline magma chambers

Directory of Open Access Journals (Sweden)

Berrahma, M.

1999-08-01

Full Text Available The integration of the differential equation of the second law of Fick applied to the diffusion of chemical elements in a semi-infinite solid made it easier to estimate the time of stay of olivine megacrysts horted into alkaline lava. The results of this research show the existence of two groups of olivine. The first remained in contact with the magmatic liquid during 30 to 34 days, while the second remained so during only 4 to 7 days only. This distinction is correlative to that based on the qualitative observation.La integración de la ecuación diferencial de la segunda ley de Fick aplicada a la difusión en un sólido semi-infinito, permitió estimar el tiempo de la residencia de los megacristales de olivino incluidos en lavas alcalinas. Los resultados muestran que existen dos grupos de olivino: el primero persiste entre 30 a 34 días, en contacto con el líquido magmático, mientras que, el segundo, solamente lo hace entre 4 a 7 días. Esta distinción está de acuerdo con la observación petrográfica.

Use of rice straw ash as substitute of feldspar in triaxial porcelain

OpenAIRE

Guzmán, Álvaro; Delvasto, Silvio; Sánchez, Enrique; Amigó Borrás, Vicente

2013-01-01

[EN] The substitution of raw materials for processing high energy consumption materials by agricultural and agro-industrial wastes causes a positive impacts on the environment preservation. One of these residues is rice straw, which according to FAO estimation, its annual production is about 600 million tons. In this research was studied the use of rice straw ash (RSA) as substitute of the use of feldspar in the whiteware production. Clay-feldspar-quartz porcelains are referred to...

Thermal significance of potassium feldspar K-Ar ages inferred from /sup 40/Ar//sup 39/Ar age spectrum results

Energy Technology Data Exchange (ETDEWEB)

Harrison, T.M.; McDougall, I. (Australian National Univ., Canberra. Research School of Earth Sciences)

1982-10-01

/sup 40/Ar//sup 39/Ar age spectrum analyses of three microcline separates from the Separation Point Batholith, northwest Nelson, New Zealand, which cooled slowly through the temperature zone of partial radiogenic /sup 40/Ar accumulation are characterized by a linear age increase over the first 65 percent of gas release with the lowest ages corresponding to the time that the samples cooled below about 100/sup 0/C. The last 35 percent of /sup 39/Ar released from the microclines yields plateau ages which reflect the different bulk mineral ages, and correspond to cooling temperatures between about 130 to 160/sup 0/C. Theoretical calculations confirm the likelihood of diffusion gradients in feldspars cooling at rates =< 5/sup 0/C-Ma/sup -1/. Diffusion parameters calculated from the /sup 39/Ar release yield an activation energy, E = 28.8 +- 1.9 kcal-mol/sup -1/, and a frequency factor/grain size parameter, D/sub 0//l/sup 2/ = 5.6sub(-3.9)sup(+14) sec/sup -1/. This Arrhenius relationship corresponds to a closure temperature of 132 +- 13/sup 0/C which is very similar to the independently estimated temperature. From the observed diffusion compensation correlation, this D/sub 0//l/sup 2/ implies an average diffusion half-width of about 3 ..mu..m, similar to the half-width of the perthite lamellae in the feldspars. The results are discussed.

Bulk rock and mineral chemistries and ascent rates of high-K calc-alkalic epidote-bearing magmas, Northeastern Brazil

Science.gov (United States)

Brasilino, R. G.; Sial, A. N.; Ferreira, V. P.; Pimentel, M. M.

2011-12-01

A manifestation of the Pan-African-Brasiliano orogeny (700-550 Ma) in northeastern Brazil was the emplacement of widespread Neoproterozoic granitoids in diverse tectonic terranes. Among these plutons are the magmatic epidote-bearing Conceição das Creoulas, Caldeirão Encantado, Murici, and Boqueirão plutons, located close to the boundary between the Alto Pajeú and Cachoeirinha-Salgueiro terranes. The plutons are high-K calc-alkalic granodiorites to monzogranites, with tabular K-feldspar megacrysts. Pistacite [atomic Fe+ 3/(Fe3++ Al)] in epidote in these granitoids ranges from 21 to 27%. High oxygen fugacity (log fO2 - 19 to - 13) and the preservation of epidote suggest that the magma was oxidized. Al-in-hornblende barometry indicates hornblende solidification between 6 and 8 kbar, at 620 to 780 °C according to the hornblende-plagioclase thermometer. Zircon saturation thermometry attests to a near-liquidus temperature range from 794 to 853 °C. Partial corrosion of magmatic epidote in these four plutons occurred during an interval of no more than 10-30 years, which corresponds to maximum magma ascent rates of 650-1000 m/year. Diking, associated with regional shearing, probably facilitated rapid transport of granitic magma through hot continental crust at peak metamorphism, and permitted survival of epidote that was out of equilibrium at the low pressure of final emplacement. Similarities between mineralogical composition, chemistry, and isotopic compositions (εNd(0.60Ga) between - 2 and - 5,TDM from 1.2 to 1.3 Ga, δ18O values > 10‰, V-SMOW) of these four plutons and Neoproterozoic magmatic epidote-bearing plutons elsewhere in northeastern Brazil, argue for similar metabasaltic/mafic sources that had previously experienced low-temperature alteration.

Complex Diffusion Mechanisms for Li in Feldspar: Re-thinking Li-in-Plag Geospeedometry

Science.gov (United States)

Holycross, M.; Watson, E. B.

2017-12-01

In recent years, the lithium isotope system has been applied to model processes in a wide variety of terrestrial environments. In igneous settings, Li diffusion gradients have been frequently used to time heating episodes. Lithium partitioning behavior during decompression or cooling events drives Li transfer between phases, but the extent of Li exchange may be limited by its diffusion rate in geologic materials. Lithium is an exceptionally fast diffuser in silicate media, making it uniquely suited to record short-lived volcanic phenomena. The Li-in-plagioclase geospeedometer is often used to time explosive eruptions by applying laboratory-calibrated Li diffusion coefficients to model concentration profiles in magmatic feldspar samples. To quantify Li transport in natural scenarios, experimental measurements are needed that account for changing temperature and oxygen fugacity as well as different feldspar compositions and crystallographic orientation. Ambient pressure experiments were run at RPI to diffuse Li from a powdered spodumene source into polished sanidine, albite, oligoclase or anorthite crystals over the temperature range 500-950 ºC. The resulting 7Li concentration gradients developed in the mineral specimens were evaluated using laser ablation ICP-MS. The new data show that Li diffusion in all feldspar compositions simultaneously operates by both a "fast" and "slow" diffusion mechanism. Fast path diffusivities are similar to those found by Giletti and Shanahan [1997] for Li diffusion in plagioclase and are typically 10 to 20 times greater than slow path diffusivities. Lithium concentration gradients in the feldspar experiments plot in the shape of two superimposed error function curves with the slow diffusion regime in the near-surface of the crystal. Lithium diffusion is most sluggish in sanidine and is significantly faster in the plagioclase feldspars. It is still unclear what diffusion mechanism operates in nature, but the new measurements may impact

Evaluation of The Use of Bentonite, Kaolin and Feldspar For Immobilizing The Uranium Radionuclide Slugdewaste

International Nuclear Information System (INIS)

Prayitno

2006-01-01

The experimental investigation on the mixture of bentonite, kaolin, feldspar, sludge waste and with the ratio of bentonite, kaolin, feldspar for evaluating its effectiveness has been done. Experimentally, this investigation is the preliminary study of the use of bentonite, kaolin, feldspar as a material for the immobilization of sludge waste containing material element especially uranium. This investigation was conducted by mixing waste (2,5; 5; 7.5; 10; 12.5 and 15 %) of total weight sludge waste and bentonite, kaolin, feldspar with of 800, 900 and 1000 o C temperature. The obtained the process condition in which the uranium fraction immobilized could be kept in the limit of safety standard for the sludge waste. Therefore, it could be concluded that the addition of hay ash as an additive in the formation of block monolith tend to minimize the leached sludge waste in the leaching media. (author)

Use of rice straw ash as substitute of feldspar in triaxial porcelain; Cenizas del tamo de arroz como substituto del feldespato en la fabricacion de ceramica blanca

Energy Technology Data Exchange (ETDEWEB)

Alvaro Guzman, A.; Silverio Delvasto, A.; Enrique Sanchez, V.; Vicente Amigo, B.

2013-02-01

The substitution of raw materials for processing high energy consumption materials by agricultural and agro-industrial wastes causes a positive impacts on the environment preservation. One of these residues is rice straw, which according to FAO estimation, its annual production is about 600 million tons. In this research was studied the use of rice straw ash as substitute of the use of feldspar in the white ware production. Clay-feldspar-quartz porcelains are referred to as triaxial white ware. Specimens of semidry triaxial mixtures, where feldspar was substituted for different percentages of CTA, were prepared by uniaxial pressing, followed by drying and sintering. Physical and mechanical properties of sintered bodies were evaluated. The porosity and the compressive strength of the fired pieces do increase with additions of up to 75% of CTA in substitution of feldspar. Their mineralogical phases were determined by DRX and SEM; grains of quartz, and needles of primary and secondary mullite were identified in a vitreous phase. It was concluded that feldspar can be substituted positively by CTA in white ware pastes. (Author) 22 refs.

Metasomatic alkali-feldspar syenites (episyenites) of the Proterozoic Suomenniemi rapakivi granite complex, southeastern Finland

Science.gov (United States)

Suikkanen, E.; Rämö, O. T.

2017-12-01

Peralkaline to marginally metaluminous alkali-feldspar syenites and quartz alkali-feldspar syenites are hosted by subalkaline, ferroan rapakivi granites in the 1644 Ma Suomenniemi complex of southeastern Finland. These alkali syenites form NW-oriented dikes and small (fingerprints are, within error, identical to those of the subalkaline granites of the complex. We propose that the Suomenniemi alkali-feldspar syenites are episyenites, formed as the result of pervasive local metasomatism of the subalkaline granites caused by high-temperature oxidizing peralkaline fluids. The process led to major geochemical changes, e.g., addition of Na, Al and Fe3 +, depletion of Si and Fe2 +, and partial to complete recrystallization of the granites along fluid pathways.

Luminescence dating of the PASADO core 5022-1D from Laguna Potrok Aike (Argentina) using IRSL signals from feldspar

DEFF Research Database (Denmark)

Buylaert, Jan-Pieter; Murray, A.S.; Gebhardt, A.C.

2013-01-01

We have measured and tested a luminescence chronology for the PASADO core 5022-1D from the maar lake of Laguna Potrok Aike. Because of unsuitable quartz OSL characteristics, sand-sized K-feldspar extracts were chosen as a dosimeter and the dose was measured using a post-IR IRSL (pIRIR290......) measurement protocol. Using this approach we were able to access a stable signal and thus avoid the ubiquitous problem of feldspar signal instability. Extensive laboratory tests show that the chosen pIRIR290 protocol is applicable to these samples. We also developed a new criterion based on known relative...... or stratigraphy; the resulting age–depth profile is self-consistent, increases smoothly with depth and is in agreement with independent age control based on volcanic ash layers (Reclús, Mt Burney and Hudson tephras) at the top and middle of the core. Our new luminescence chronology suggests that the 5022-1D core...

Full analysis of feldspar texture and crystal structure by combining X-ray and electron techniques

DEFF Research Database (Denmark)

Balic Zunic, Tonci; Piazolo, Sandra; Katerinopoulou, Anna

2013-01-01

identification plus crystal structure refinement of all components in a feldspar intergrowth. This procedure was applied to perthitic intergrowths in feldspars from two different pegmatites in the Larvik plutonic complex in the southern part of the Oslo region, Norway. It revealed that the two starting high...

Understanding optically stimulated charge movement in quartz and feldspar using time-resolved measurements

DEFF Research Database (Denmark)

Ankjærgaard, Christina

. Although, results are only presented for some quartz and feldspar samples, they were found to be very similar within the each group during the course of this work.Thermoluminescence (TL) and optically stimulated luminescence (OSL) from quartz and feldspar are widely used in accident dosimetry...... stimulation energy. The thesis first delves into three main methodological developments, namely (i) research and development of the equipment for TR-OSL measurements, (ii) finding the best method for multiple-exponential analysis of a TR-OSL curve, and (iii) optimisation of the pulsing configuration...... of the equipment for TR-OSL measurements, (ii) finding the best method for multiple-exponential analysis of a TR-OSL curve, and (iii) optimisation of the pulsing configuration for the best separation of quartz OSL from a mixed quarts-feldspar sample. It then proceeds to study the different charge transport...

Radioluminescence dating: the IR emission of feldspar

International Nuclear Information System (INIS)

Schilles, Thomas.; Habermann, Jan

2000-01-01

A new luminescence reader for radioluminescence (RL) measurements is presented. The system allows detection of RL emissions in the near infrared region (IR). Basic bleaching properties of the IR-RL emission of feldspars are investigated. Sunlight-bleaching experiments as a test for sensitivity changes are presented. IR-bleaching experiments were carried out to obtain information about the underlying physical processes of the IR-RL emission

Tibetan tectonics from 40Ar/39Ar analysis of a single K-feldspar sample

International Nuclear Information System (INIS)

Richter, F.M.; Lovera, O.M.; Harrison, T.M.; Copeland, P.

1991-01-01

40 Ar/ 39 Ar data on an alkali feldspar sample from the Quxu pluton, Gangdese batholith, southern Tibet, allow a detailed assessment of unroofing and uplift history between 35 and 18 Ma. The 39 Ar Arrhenius plot for this sample shows departures from a linear relationship between the effective diffusion parameter, log(D/r 2 ), and reciprocal temperature, which we interpret to be the result of a distribution of distinct diffusion-domain sizes. We use an alternative way of plotting the Arrhenius data that exhibits domain size versus cumulative % 39 Ar released during step heating. The 40 Ar/ 39 Ar age spectrum of the sample has features, such as local age plateaus, that are most easily explained in terms of the distinctive closure age of particular domains. The fact that the same distribution of diffusion-domain sizes explains both the Arrhenius data and the age spectrum is an indication that the diffusion properties operating in the laboratory are those of the sample while it was in its natural environment. Modelling of the age spectrum with a distribution of domain sizes results in the recovery of a continuous cooling-history segment rather than a single time-temperature datum. We demonstrate the robustness of the cooling-curve determination by showing the large misfits to the age spectrum that arise from relatively small changes in the cooling history. The best-fit cooling curve for the Quxu sample shows a decreasing rate of cooling in the time interval 35-18 Ma, followed by a very rapid cooling beginning at about 18 Ma. We have used a thermal model for the conductive cooling of an unroofing pluton to estimate the rate of unroofing required to explain the Quxu cooling curve, and find that in the 35-20 Ma time interval, the primary control of the thermal evolution is the conductive loss of magmatic heat with little or no unroofing (unroofing rates of approximately 0.05 mm/yr) followed by a brief period (<5 Ma) of very rapid unroofing with rates of order 2 mm

Pre-treatment of desalination feed seawater by Jordanian Tripoli, Pozzolana and Feldspar: batch experiments

Directory of Open Access Journals (Sweden)

AIMAN E. AL-RAWAJFEH

2011-06-01

Full Text Available In this research, composites of layered double hydroxide (LDH with three Jordanian natural raw materials: Tripoli (T, Pozzolana (P and Feldspar (F were prepared by co-precipitation and have been used for feed seawater pre-treatment. The data reveals that percent adsorption decreased with increase in initial concentration, but the actual amount of adsorbed ions per unit mass of LDH/T-P-F increased with increase in metal ion concentrations. The values of ΔG were negative and within 21 to 26 kJ/mol, while the values of and ΔS were positive, with ΔH within the range of 0.1 to 25 kJ/mol. The values of ΔH, ΔS and ΔG indicate the favorability of physisorption and show that the LDH/T-P-F composites have a considerable potential as adsorbents for the removal of ions from seawater.

On the effect of optical and isothermal treatments on luminescence signals from feldspars

International Nuclear Information System (INIS)

Pagonis, Vasilis; Polymeris, George; Kitis, George

2015-01-01

During luminescence dosimetry and luminescence dating applications it is often necessary to precondition the geological samples by applying a thermal or optical treatment before measuring the luminescence signal. In luminescence applications using apatites or feldspars, measurement of continuous-wave infrared or optically stimulated signals (CW-IRSL and CW-OSL) are customarily preceded by either an isothermal heating of the samples at a fixed temperature for a short time interval, or alternatively by optically bleaching the samples using light from LEDs with the appropriate wavelength. This paper presents new analytical equations which can be used to describe these commonly employed double experimental procedures. The equations are based on a recently published model which assumes that tunneling processes are taking place in random distributions of donor–acceptor pairs. The concentration of charge carriers during the CW-IRSL or CW-OSL experiment is expressed in terms of the parameters of the preceding thermal or optical bleaching procedure, and depends also on the distribution of distances between electron and hole pairs. The analytical equations in this paper are compared with experimental data from a feldspar sample which undergoes an isothermal procedure followed by measurement of the CW-IRSL signal. Additional comparisons with experiment are provided using a feldspar sample which undergoes an infrared bleaching process, followed by measurement of the CW-OSL signal. These results and conditions under which the equations can be used are discussed within the framework of the model. - Highlights: • CW-IRSL and CW-OSL measurements are preceded by heating or optical bleaching. • New analytical equations are derived to describe these double experimental procedures. • Equations are compared with data from a feldspar sample following isothermal procedure. • Equations are compared with data from a feldspar sample following optical bleaching.

What classic greywacke (litharenite) can reveal about feldspar diagenesis: An example from Permian Rotliegend sandstone in Hessen, Germany

Science.gov (United States)

Molenaar, Nicolaas; Felder, Marita; Bär, Kristian; Götz, Annette E.

2015-08-01

Rotliegend siliciclastic sediments in southern Hessen (Germany) are a good example of dissolution of detrital feldspars, which is a common feature in many sandstones. Dissolution occurred after mechanical compaction of the lithic-rich sandstone, which experienced framework collapse with pores and pore connections filled and obstructed by deformed ductile lithic grains (pseudomatrix) thereby reducing pore space to microporosity., The advanced degree of compaction and reduced porosity caused low permeability and low hydraulic conductivity of the rock mass. This is further reduced by the presence of wackes and shales that occur intercalated with the sandstones. Feldspar dissolution thus took place in low permeable sediments when large-scale flow of meteoric or acidic fluids is ruled out as a cause of feldspar dissolution. Mineral precipitation (illite, kaolinite, and albite) took place within pseudomatrix and detrital matrix as well as in secondary pores created by feldspar dissolution. Feldspar was the source for the authigenesis. The system was thus closed during burial after framework collapse, and diagenetic reactants in the form of detrital components were already present within the system. The original mass was preserved, but redistributed and diagenetic minerals were the local sinks for the dissolved reactants, precipitating within the system. This also suggests that burial diagenesis in general might be more mass conservative than usually assumed. Rotliegend sandstones thus form a case where, despite of the lack of external exchange of mass by fluid flow, major diagenetic processes did take place and significantly modified the original mineralogy and texture. Feldspar diagenesis can take place from other processes than mere large-scale flushing of open systems as often supposed. It implies that the volumes of rock affected by feldspar diagenesis may be much larger than anticipated based upon the common hold believe that feldspar diagenesis is linked to

Feldspar 40Ar/39Ar dating of ICDP PALEOVAN cores

Science.gov (United States)

Engelhardt, Jonathan Franz; Sudo, Masafumi; Stockhecke, Mona; Oberhänsli, Roland

2017-11-01

Volcaniclastic fall deposits in ICDP drilling cores from Lake Van, Turkey, contain sodium-rich sanidine and calcium-rich anorthoclase, which both comprise a variety of textural zoning and inclusions. An age model records the lake's history and is based on climate-stratigraphic correlations, tephrostratigraphy, paleomagnetics, and earlier 40Ar/39Ar analyses (Stockhecke et al., 2014b). Results from total fusion and stepwise heating 40Ar/39Ar analyses presented in this study allow for the comparison of radiometric constraints from texturally diversified feldspar and the multi-proxy lacustrine age model and vice versa. This study has investigated several grain-size fractions of feldspar from 13 volcaniclastic units. The feldspars show textural features that are visible in cathodoluminescence (CL) or back-scattered electron (BSE) images and can be subdivided into three dominant zoning-types: (1) compositional zoning, (2) round pseudo-oscillatory zoning and (3) resorbed and patchy zoning (Ginibre et al., 2004). Round pseudo-oscillatory zoning records a sensitive alternation of Fe and Ca that also reflects resorption processes. This is only visible in CL images. Compositional zoning reflects anticorrelated anorthite and orthoclase contents and is visible in BSE. Eleven inverse isochron ages from total fusion and three from stepwise heating analyses fit the age model. Four experiments resulted in older inverse isochron ages that do not concur with the model within 2σ uncertainties and that deviate from 1 ka to 17 ka minimum. C- and R-type zoning are interpreted as representing growth in magma chamber cupolas, as wall mushes, or in narrow conduits. Persistent compositions of PO-type crystals and abundant surfaces recording dissolution features correspond to formation within a magma chamber. C-type zoning and R-type zoning have revealed an irregular incorporation of melt and fluid inclusions. These two types of zoning in feldspar are interpreted as preferentially

Late Quaternary cooling rate constrained by multiple IRSL thermochronometers of potassium feldspars for granites from Kongur Shan, Chinese Pamir

Science.gov (United States)

Qin, Jintang; Chen, Jie; Valla, Pierre; Herman, Frédéric

2015-04-01

The Kongur Shan (East Pamir), located at the northwestern Tibetan Plateau, is one of the most active orogens on Earth, where both tectonic processes along major active faults and climatic forcing (extensive glaciers coverage) are contributing to the regional landscape evolution. The exhumation rates since late Miocene was constrained to be ~6.5 - 4.2 mm/yr. However, it is still debated whether the exhumation rate accelerated since the Quaternary, of which the climate was featured by the cyclic glaciations with periods of 100 ka and 40 ka. In this study, we tried to employ luminescence thermochronology, which is a still in developing method, to resolve the impact of glacial cycles on exhumation rate. Our study site is located ~10 km to the east of the active Kongur normal fault, along the major valley of Gez river. We sampled three granite rocks from a sub-horizontal tunnel across the granite massif; one was from the entrance of the tunnel, and other two samples were from inside of the tunnel, where the measured ambient temperature is as high as 60-70 ° C. The distances of these samples are within 2 km. Four types of IRSL signals extracted from potassium feldspars (K-feldspars) were measured for each individual sample, and the results of isothermal decay experiments indicated these signals were of different thermal stabilities. Therefore, they may serve as four thermochronometers with different closure temperature. We employ these multiple thermochronometers together for each single sample to constrain their cooling rates. Our preliminary results, which are based on the simplified luminescence model of K-feldspars, suggest that the averaged cooling rate of the last 200 ka is as high as 1.4 oC/ka, which corresponds to an exhumation rate of ~ 2.3 to 0.9 cm/yr with the geothermal gradient assumed to be 60 to 150 oC/km. It seems to imply that the glacial cycles during the Quaternary substantially accelerated the exhumation rate of granite massif of Kongur Shan.

Understanding the ice nucleation characteristics of feldspars suspended in solution

Science.gov (United States)

Kumar, Anand; Marcolli, Claudia; Kaufmann, Lukas; Krieger, Ulrich; Peter, Thomas

2017-04-01

Chemical) and 5 wt% lanolin (Fluka Chemical) is emulsified with a rotor-stator homogenizer for 40 s at a rotation frequency of 7000 rpm. 4 - 10 mg of this mixture is pipetted in an aluminum pan (closed hermetically), placed in the DSC and subjected to three freezing cycles. The first and the third freezing cycles are executed at a cooling rate of 10 K/min to control the stability of the sample. The second freezing cycle is executed at a 1 K/min cooling rate and is used for evaluation. Freezing temperatures are obtained by evaluating the onset of the freezing signal in the DSC curve and plotted against water activity. Results Based on Koop et al. (2000), a general decreasing trend in ice nucleation efficiency of the mineral samples with increasing solute concentrations is expected. Interestingly, feldspars (microcline, sanidine, plagioclase) in very dilute solutions of ammonia and ammonium salts (water activity close to one) show an increase in ice nucleation efficiency of 4 to 6 K compared to that in pure water. Similar trends but less pronounced are observed for kaolinite while quartz shows barely any effect. Therefore, there seem to be specific interactions between the feldspar surface and ammonia and/or ammonium ions which result in an increase in freezing temperatures at low solute concentrations. The surface ion exchange seems to be secondary for this effect since it is also present in ammonia solution. We hypothesize that ammonia adsorbs on the aluminol/silanol groups present on feldspar (viz. aluminosilicate surface) surfaces (Nash and Marshall, 1957; Belchinskaya et al., 2013). Hence allowing one of the N-H bonds to stick outwards from the surface, facing towards the bulk water and providing a favorable template for ice to grow. The current study gives an insight into the ice nucleation behavior of aluminosilicate minerals when present in conjunction with chemical species, eg. ammonium/sulfates, which is of high atmospheric relevance. References Koop et al., (2000

Alkali feldspar syenites with shoshonitic affinities from Chhotaudepur area: Implication for mantle metasomatism in the Deccan large igneous province

Directory of Open Access Journals (Sweden)

K.R. Hari

2014-03-01

Full Text Available Two petrologically distinct alkali feldspar syenite bodies (AFS-1 and AFS-2 from Chhotaudepur area, Deccan Large Igneous Province are reported in the present work. AFS-1 is characterized by hypidiomorphic texture and consists of feldspar (Or55Ab43 to Or25Ab71, ferro-pargasite/ferro-pargasite hornblende, hastingsite, pyroxene (Wo47, En5, Fs46, magnetite and biotite. AFS-2 exhibits panidiomorphic texture with euhedral pyroxene (Wo47-50, En22-39, Fs12–31 set in a groundmass matrix of alkali feldspar (Or99Ab0.77 to Or1.33Ab98, titanite and magnetite. In comparison to AFS-1, higher elemental concentrations of Ba, Sr and ∑REE are observed in AFS-2. The average peralkaline index of the alkali feldspar syenites is ∼1 indicating their alkaline nature. Variation discrimination diagrams involving major and trace elements and their ratios demonstrate that these alkali feldspar syenites have a shoshonite affinity but emplaced in a within-plate and rifting environment. No evidence of crustal contamination is perceptible in the multi-element primitive mantle normalized diagram as well as in terms of trace elemental ratios. The enrichment of incompatible elements in the alkali feldspar syenites suggests the involvement of mantle metasomatism in their genesis.

Quantitative analysis of time-resolved infrared stimulated luminescence in feldspars

Energy Technology Data Exchange (ETDEWEB)

Pagonis, Vasilis, E-mail: vpagonis@mcdaniel.edu [McDaniel College, Physics Department, Westminster, MD 21157 (United States); Ankjærgaard, Christina [Soil Geography and Landscape Group & Netherlands Centre for Luminescence dating, Wageningen University, PO Box 47, 6700 AA Wageningen (Netherlands); Jain, Mayank [Center for Nuclear Technologies, Technical University of Denmark, DTU Risø Campus, Roskilde (Denmark); Chithambo, Makaiko L. [Department of Physics and Electronics, Rhodes University, PO BOX 94, Grahamstown 6140 (South Africa)

2016-09-15

Time-resolved infrared-stimulated luminescence (TR-IRSL) from feldspar samples is of importance in the field of luminescence dating, since it provides information on the luminescence mechanism in these materials. In this paper we present new analytical equations which can be used to analyze TR-IRSL signals, both during and after short infrared stimulation pulses. The equations are developed using a recently proposed kinetic model, which describes localized electronic recombination via tunneling between trapped electrons and recombination centers in luminescent materials. Recombination is assumed to take place from the excited state of the trapped electron to the nearest-neighbor center within a random distribution of luminescence recombination centers. Different possibilities are examined within the model, depending on the relative importance of electron de-excitation and recombination. The equations are applied to experimental TR-IRSL data of natural feldspars, and good agreement is found between experimental and modeling results.

Beneficiation of feldspar ore for application in the ceramic industry: Influence of composition on the physical characteristics

Directory of Open Access Journals (Sweden)

M.E. Gaied

2015-03-01

Experimental studies indicate that an acceptable concentrate for industrial application can be obtained from these rocks. The feldspar yield was used to evaluate the process efficiency. Besides, the cone shrinkage, water absorption, degree of vitrification, mechanical properties (flexural strength and dielectric behaviour were used to monitor the quality of the recovered feldspars.

Thermal quenching of luminescence processes in feldspars

DEFF Research Database (Denmark)

Poolton, N.R.J.; Bøtter-Jensen, L.; Duller, G.A.T.

1995-01-01

, which display very different behaviour. The first involves the internal transitions of common transition metal ions. The second is typical of centres not displaying excited states within the band gap that are likely to arise from direct recombination between the conduction band and the ground state......The technique of optically stimulated luminescence has important uses in the dose evaluation of irradiated feldspars. The luminescence process involves the eviction of electrons from donor traps, charge transfer through the conduction band, and recombination at acceptor sites; each...

Quantitative analysis of time-resolved infrared stimulated luminescence in feldspars

DEFF Research Database (Denmark)

Pagonis, Vasilis; Ankjærgaard, Christina; Jain, Mayank

2016-01-01

Time-resolved infrared-stimulated luminescence (TR-IRSL) from feldspar samples is of importance in the field of luminescence dating, since it provides information on the luminescence mechanism in these materials. In this paper we present new analytical equations which can be used to analyze TR-IR...

Surface studies of feldspar dissolution using surface replication combined with electron microscopic and spectroscopic techniques

Energy Technology Data Exchange (ETDEWEB)

Fung, P C [Petro-Canada, Calgary, Alberta; Sanipelli, G G

1982-04-01

The replica of a microcline cleavage surface was examined before and at various stages of interaction with water and acid solutions at 70/sup 0/C, as part of basic geochemical research for the Canadian Nuclear Fuel Waste Management Program to investigate the feasibility of disposal of these wastes in repositories mined in crystalline rocks. The objective of the report presented was to investigate the mechanism for Al and Si removal during incongruent dissolution of feldspars and its effect on dissolution rate. It was found that phase transformation, like dissolution occured preferentially along crystal defects on the surfaces of the feldspars. Secondary minerals always occured as discrete particles occupying only a very small fraction of the total parent surface, and hence, their presence would not affect the bulk composition or, in this regard, the overall dissolution rate of the feldspars by the formation of diffusion barriers.

Luminescence at the end of the tunnelling - Investigating charge transfer mechanisms and luminescence dating methods for feldspar minerals

NARCIS (Netherlands)

Kars, R.H.

2014-01-01

This thesis comprises analyses of mineral physics with an application in geology and archeology. The thesis contributes to the development of feldspar luminescence dating methods in order to extend the applicable age range of feldspar luminescence dating in the Quaternary (last 2.6 Ma). The research

New ages for Middle and Later Stone Age deposits at Mumba rockshelter, Tanzania: optically stimulated luminescence dating of quartz and feldspar grains.

Science.gov (United States)

Gliganic, Luke A; Jacobs, Zenobia; Roberts, Richard G; Domínguez-Rodrigo, Manuel; Mabulla, Audax Z P

2012-04-01

The archaeological deposits at Mumba rockshelter, northern Tanzania, have been excavated for more than 70 years, starting with Margit and Ludwig Köhl-Larsen in the 1930s. The assemblages of Middle Stone Age (MSA) and Later Stone Age (LSA) artefacts collected from this site constitute the type sequences for these cultural phases in East Africa. Despite its archaeological importance, however, the chronology of the site is poorly constrained, despite the application since the 1980s of several dating methods (radiocarbon, uranium-series and amino acid racemisation) to a variety of materials recovered from the deposits. Here, we review these previous chronologies for Mumba and report new ages obtained from optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL) measurements on single grains of quartz and multi-grain aliquots of potassium (K) feldspar from the MSA and LSA deposits. Measurements of single grains of quartz allowed the rejection of unrepresentative grains and the application of appropriate statistical models to obtain the most reliable age estimates, while measurements of K-feldspars allowed the chronology to be extended to older deposits. The seven quartz ages and four K-feldspar ages provide improved temporal constraints on the archaeological sequence at Mumba. The deposits associated with the latest Kisele Industry (Bed VI-A) and the earliest Mumba Industry (Bed V) are dated to 63.4 ± 5.7 and 56.9 ± 4.8 ka (thousands of years ago), respectively, thus constraining the time of transition between these two archaeological phases to ~60 ka. An age of 49.1 ± 4.3 ka has been obtained for the latest deposits associated with the Mumba Industry, which show no evidence for post-depositional mixing and contain ostrich eggshell (OES) beads and abundant microlithics. The Nasera Industry deposits (Bed III) contain large quantities of OES beads and date to 36.8 ± 3.4 ka. We compare the luminescence ages with the previous chronologies for

Bleaching of the thermoluminescence of feldspars by selected wavelengths present in sunlight

International Nuclear Information System (INIS)

Robertson, G.B.; Prescott, J.R.; Hutton, J.T.

1993-01-01

Feldspars occur in many sediments, and dating them by thermoluminescence (TL) requires a knowledge of how efficiently sunlight bleaches these minerals. The relative bleaching efficiencies of various wavelengths have been investigated for four alkali feldspars and an oligoclase, using the natural TL of the samples and the artificial TL induced by laboratory irradiation, bleached by wavelengths in the range 322-550 nm. Ultraviolet wavelengths are more efficient than the longer wavelengths at bleaching all the glow-curve peaks and are responsible for most of the phototransfer from high-temperature peaks to low-temperature peaks. Some feldspars show an initial increase in TL intensity with bleaching. Two sanidines of similar bulk composition but different TL glow curves show different dependences on bleaching wavelength. In a sodic sanidine with a dominant 240 o C peak the energy required to bleach to 50% was a thousand times greater at 550 nm than at 322 nm. In contrast, another sanidine with a complex glow curve between 150 and 450 o C showed a much slower change in the 330 o C peak with wavelength - a factor of 10 between 322 and 550 nm - with a region between 400 and 500 nm which was almost independent of wavelength. This behaviour is explained by competing mechanisms of phototransfer and bleaching which depend on wavelength in different ways. (author)

Determining the k in k-means with MapReduce

OpenAIRE

Debatty , Thibault; Michiardi , Pietro; Mees , Wim; Thonnard , Olivier

2014-01-01

International audience; In this paper we propose a MapReduce implementation of G-means, a variant of k-means that is able to automatically determine k, the number of clusters. We show that our implementation scales to very large datasets and very large values of k, as the computation cost is proportional to nk. Other techniques that run a clustering algorithm with different values of k and choose the value of k that provides the " best " results have a computation cost that is proportional to...

To the problem of paleodosimetrical information stability in alkali feldspars

International Nuclear Information System (INIS)

Huett, Galina; Jaek, Ivar

1997-01-01

The stability of holes of the centres of recombination in alkali feldspars, extracted from sediments, is studied. For the emission centres with 410 and 570 nm the energy of activation of thermal quenching is obtained (> 2 eV). Problems of fading and difference between thermoluminescence (TL) and optically stimulated luminescence (OSL), as well as bleach abilities, are discussed. Values of thermal activation energy (> 2 eV) obtained for two different emission bands (410 and 570 nm) in alkali feldspars prove the upper limit of dating (c 10 5 years). The absence of a permanent channel of fading is supported by experimental data. Differences in bleach ability, as well as in residuals of TL and OSL response dating signals, are explained within the frame of the proposed model of identity of defects responsible for those signals. It is supposed that better bleach ability of the OSL signal is connected with optical selection of more transparent grains (or more easily bleach able centres). The applicability of the orange band of emission (570 nm) for dating is recommended for future study

Biochemical evolution. I. Polymerization on internal, organophilic silica surfaces of dealuminated zeolites and feldspars

Science.gov (United States)

Smith, Joseph V.

1998-01-01

Catalysis at mineral surfaces might generate replicating biopolymers from simple chemicals supplied by meteorites, volcanic gases, and photochemical gas reactions. Many ideas are implausible in detail because the proposed mineral surfaces strongly prefer water and other ionic species to organic ones. The molecular sieve silicalite (Union Carbide; = Al-free Mobil ZSM-5 zeolite) has a three-dimensional, 10-ring channel system whose electrically neutral Si-O surface strongly adsorbs organic species over water. Three -O-Si tetrahedral bonds lie in the surface, and the fourth Si-O points inwards. In contrast, the outward Si-OH of simple quartz and feldspar crystals generates their ionic organophobicity. The ZSM-5-type zeolite mutinaite occurs in Antarctica with boggsite and tschernichite (Al-analog of Mobil Beta). Archean mutinaite might have become de-aluminated toward silicalite during hot/cold/wet/dry cycles. Catalytic activity of silicalite increases linearly with Al-OH substitution for Si, and Al atoms tend to avoid each other. Adjacent organophilic and catalytic Al-OH regions in nanometer channels might have scavenged organic species for catalytic assembly into specific polymers protected from prompt photochemical destruction. Polymer migration along weathered silicic surfaces of micrometer-wide channels of feldspars might have led to assembly of replicating catalytic biomolecules and perhaps primitive cellular organisms. Silica-rich volcanic glasses should have been abundant on the early Earth, ready for crystallization into zeolites and feldspars, as in present continental basins. Abundant chert from weakly metamorphosed Archaean rocks might retain microscopic clues to the proposed mineral adsorbent/catalysts. Other framework silicas are possible, including ones with laevo/dextro one-dimensional channels. Organic molecules, transition-metal ions, and P occur inside modern feldspars. PMID:9520372

Possible reasons for anomalous fading in alkali feldspars used for luminescence dating of Quaternary deposits

Directory of Open Access Journals (Sweden)

Jaek, Ivar

2007-09-01

Full Text Available According to many publications, alkali feldspars are characterized by specific athermal (anomalous fading of their thermoluminescence and optically-stimulated luminescence. This phenomenon is manifested as spontaneous decline in luminescence intensity over relatively long (months and years time after laboratory irradiation, possibly due to tunnelling of electrons from lattice defects and impurities acting as dosimetric traps. It can hamper reliable luminescent dating of Quaternary deposits on the basis of feldspar extractions due to possible unpredictable underestimation of the ages. In this paper we present some experimental results related to the manifestation of the phenomenon. It is found that, in general case, the assumed long-term anomalous fading cannot be connected to electron tunnelling from the deep dosimetric traps. At the same time, some decrease in the dosimetric luminescence signal observable in just irradiated feldspar samples can really be caused by tunnelling. However, the probability of this process quickly goes down, already within some days after irradiation. Interpretation of some other short- and long-term anomalous fading-like effects requires involvement of radiation- and thermo-induced ionic processes.

Luminescence characteristics of quartz and feldspar from tectonically uplifted terraces in Kashmir Basin, Jammu and Kashmir, India

International Nuclear Information System (INIS)

Jaiswal, Manoj K.; Bhat, M.I.; Bali, B.S.; Ahmad, Shabir; Chen, Y.G.

2009-01-01

The Kashmir Valley or the Jhelum basin is an intermontane-basin in NW Himalaya bounded by the Pir Panjal Range in the south and southwest and the Great Himalayan Range in the north and northeast. The valley is marked by active major thrust boundaries in its south and southwestern parts. Remote sensing studies and morphometric analysis suggest neo-tectonic activities and the formation of tectonic terraces due to uplift on the major thrust boundaries in NW Himalayas. The quartz from freshly eroded mountain belts is usually found to show very poor luminescence sensitivity and thus not suitable for optical dating. Similar problems occurred with the quartz from the Srinagar Basin. Due to this, feldspar was selected as a natural dose meter for dating tectonically uplifted terraces in an active and dynamic belt of the NW Himalayas. We report here for the first time the luminescence characteristics of quartz and feldspar minerals from the study area. However, feldspar also shows poor luminescence sensitivity, although enough to perform optical dating. Athermal fading was observed in all the feldspar samples, which was corrected using 'g' values; a large scatter was found in the g values, probably due to intermixing of feldspar grains from varying source rock types and also due to poor luminescence sensitivity. An average g value correction to the mean paleodose was found to agree if compared with the thermo-luminescence date of loess deposit dated earlier. The ages show that the terrace formation started taking place at ∼100 ka in the southwestern part of the Jhelum basin and continued with pulses at 50 ka and 11 ka towards the northwestern part.

Fabrication and characterization of low temperature co-fired cordierite glass–ceramics from potassium feldspar

International Nuclear Information System (INIS)

Wu, Jianfang; Li, Zhen; Huang, Yanqiu; Li, Fei; Yang, Qiuran

2014-01-01

Highlights: • Low cost cordierite glass–ceramics were fabricated from potassium feldspar. • The glass–ceramics could be highly densified below 950 °C. • The glass–ceramics exhibit extraordinary properties. • The glass–ceramics can be used as LTCC substrates. • The excess SiO 2 improved the microstructure and properties of the glass–ceramics. -- Abstract: Cordierite glass–ceramics for low temperature co-fired ceramic (LTCC) substrates were fabricated successfully using potassium feldspar as the main raw material. The sintering and crystallization behaviors of the glass–ceramics were investigated by the differential scanning calorimetry (DSC), X-ray diffraction (XRD), and field emission scanning electron microscope (FESEM). The results indicated that the glass–ceramics could be highly densified at 850 °C and the cordierite was the main crystalline phase precipitated from the glasses in the temperature range between 900 and 925 °C. The study also evaluated the physical properties including dielectric properties, thermal expansion and flexural strength of the glass–ceramics. The glass–ceramics showed low dielectric constants in the range of 6–8 and low dielectric losses in the range of 0.0025–0.01. The coefficients of thermal expansion (CTEs) are between 4.32 and 5.48 × 10 −6 K −1 and flexural strength of the glass–ceramics are 90–130 MPa. All of those qualify the glass–ceramics for further research to be used as potential LTCC substrates in the multilayer electronic substrate field. Additionally, the excess SiO 2 acted as a great role in improving the sinterability of the glasses, and the microstructure and dielectric properties of the relevant glass–ceramics

Testing feldspar luminescence dating of young archaeological heated materials using potshards from Pella (Tell Tabqat Fahl) in the Jordan valley

DEFF Research Database (Denmark)

Khasswneh, Sahar Al; Murray, Andrew Sean; Bourke, Stephen

2017-01-01

Recent developments in the use of more stable feldspar signals in the luminescence dating of sediments offer the possibility of obtaining accurate feldspar luminescence ages for ceramic artefacts; this is especially interesting in locations which do not provide suitable quartz extracts. Here we e...

Some evidence of uranium in volcanic feldspar rocks in the state of Sonora

Energy Technology Data Exchange (ETDEWEB)

Marquina M, O. E. [Uranio Mexicano, Mexico City

1983-05-15

Description is given of four projects of exploration and survey for uranium associated with tertiary volcanic feldspar rocks importantly dispersed in the State of Sonora and being carried out by Uranium Mexicano.

K-Ca and Rb-Sr Dating of Lunar Granite 14321 Revisited

Science.gov (United States)

Simon, Justin I.; Shih, C.-Y.; Nyquist, L. E.

2011-01-01

K-Ca and Rb-Sr age determinations were made for a bulk feldspar-rich portion of an Apollo rock fragment of the pristine lunar granite clast (14321,1062), an acid-leached split of the sample, and the leachate. K-Ca and Rb-Sr data were also obtained for a whole rock sample of Apollo ferroan anorthosite (FAN, 15415). The recent detection [1] of widespread intermediate composition plagioclase indicates that the generation of a diversity of evolved lunar magmas maybe more common and therefore more important to our understanding of crust formation than previously believed. Our new data strengthen the K-Ca and Rb-Sr internal isochrons of the well-studied Apollo sample 14321 [2], which along with a renewed effort to study evolved lunar magmas will provide an improved understanding of the petrogenetic history of evolved rocks on the Moon.

Influence of diopside: feldspar ratio in ceramic reactions assessed by quantitative phase analysis (X-ray diffraction - Rietveld method)

International Nuclear Information System (INIS)

Kuzmickas, L.; Andrade, F.R.D.; Szabo, G.A.J.; Motta, J.F.M.; Cabral Junior, M.

2013-01-01

White ceramics were produced with raw mixtures prepared with varying proportions of diopside-rich rock (0 to 20 wt.%) and potassic feldspar (40 to 20 wt.%), and fixed proportions of kaolinite (40 wt.%) and quartz (20 wt.%), fired in a temperature range from 1170 to 1210 deg C. The phases identified in the experimental ceramics were quartz, anorthite, mullite and glass, and their relative mass proportions were determined by X-ray diffraction (Rietveld method). The addition of diopside as a partial substitute for potassic feldspar causes the formation of a calcium silicate, analogous of the natural anorthite (CaSi 2 Al 2 O 8 ) in the ceramics, with proportional reduction in its glass and mullite contents. Water absorption and porosity of the ceramic bodies clearly decrease with increasing firing temperature, while the effect of the raw mixture composition on the physical and mechanical properties of the ceramics is less evident. Diopside-rich rock has low iron content (1.5 wt.% Fe 2 O 3 ) and, therefore, promotes white burning. (author)

Influence of diopside: feldspar ratio in ceramic reactions assessed by quantitative phase analysis (X-ray diffraction - Rietveld method)

Energy Technology Data Exchange (ETDEWEB)

Kuzmickas, L.; Andrade, F.R.D.; Szabo, G.A.J. [Universidade de Sao Paulo (IGc/USP), SP (Brazil). Inst. de Geociencias. Dept. de Mineralogia e Geotecnia; Motta, J.F.M.; Cabral Junior, M., E-mail: lukuzmickas@gmail.com, E-mail: dias@usp.br, E-mail: gajszabo@usp.b, E-mail: motta.jf@gmail.com, E-mail: marsis@ipt.br [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil). Secao de Recursos Minerais e Tecnologia Ceramica

2013-04-15

White ceramics were produced with raw mixtures prepared with varying proportions of diopside-rich rock (0 to 20 wt.%) and potassic feldspar (40 to 20 wt.%), and fixed proportions of kaolinite (40 wt.%) and quartz (20 wt.%), fired in a temperature range from 1170 to 1210 deg C. The phases identified in the experimental ceramics were quartz, anorthite, mullite and glass, and their relative mass proportions were determined by X-ray diffraction (Rietveld method). The addition of diopside as a partial substitute for potassic feldspar causes the formation of a calcium silicate, analogous of the natural anorthite (CaSi{sub 2}Al{sub 2}O{sub 8}) in the ceramics, with proportional reduction in its glass and mullite contents. Water absorption and porosity of the ceramic bodies clearly decrease with increasing firing temperature, while the effect of the raw mixture composition on the physical and mechanical properties of the ceramics is less evident. Diopside-rich rock has low iron content (1.5 wt.% Fe{sub 2}O{sub 3}) and, therefore, promotes white burning. (author)

Radiation-induced growth and isothermal decay of infrared-stimulated luminescence from feldspar

DEFF Research Database (Denmark)

Guralnik, Benny; Li, Bo; Jain, Mayank

2015-01-01

the growth and decay of laboratory-regenerated luminescence signals. Here we review a selection of common models describing the response of infrared stimulated luminescence (IRSL) of feldspar to constant radiation and temperature as administered in the laboratory. We use this opportunity to introduce...

The Late Cretaceous Middle Fork caldera, its resurgent intrusion, and enduring landscape stability in east-central Alaska

Science.gov (United States)

Bacon, Charles R.; Dusel-Bacon, Cynthia; Aleinikoff, John N.; Slack, John F.

2014-01-01

Dissected caldera structures expose thick intracaldera tuff and, uncommonly, cogenetic shallow plutons, while remnants of correlative outflow tuffs deposited on the pre-eruption ground surface record elements of ancient landscapes. The Middle Fork caldera encompasses a 10 km × 20 km area of rhyolite welded tuff and granite porphyry in east-central Alaska, ∼100 km west of the Yukon border. Intracaldera tuff is at least 850 m thick. The K-feldspar megacrystic granite porphyry is exposed over much of a 7 km × 12 km area having 650 m of relief within the western part of the caldera fill. Sensitive high-resolution ion microprobe with reverse geometry (SHRIMP-RG) analyses of zircon from intracaldera tuff, granite porphyry, and outflow tuff yield U-Pb ages of 70.0 ± 1.2, 69.7 ± 1.2, and 71.1 ± 0.5 Ma (95% confidence), respectively. An aeromagnetic survey indicates that the tuff is reversely magnetized, and, therefore, that the caldera-forming eruption occurred in the C31r geomagnetic polarity chron. The tuff and porphyry have arc geochemical signatures and a limited range in SiO2 of 69 to 72 wt%. Although their phenocrysts differ in size and abundance, similar quartz + K-feldspar + plagioclase + biotite mineralogy, whole-rock geochemistry, and analytically indistinguishable ages indicate that the tuff and porphyry were comagmatic. Resorption of phenocrysts in tuff and porphyry suggests that these magmas formed by thermal rejuvenation of near-solidus or solidified crystal mush. A rare magmatic enclave (54% SiO2, arc geochemical signature) in the porphyry may be similar to parental magma and provides evidence of mafic magma and thermal input.

Illite K-Ar dating of fault breccia samples from ONKALO underground research facility, Olkiluoto, Eurajoki, SW Finland

International Nuclear Information System (INIS)

Maenttaeri, I.; Mattila, J.; Zwingmann, H.; Todd, A.J.

2007-08-01

Illite K-Ar age determinations were done on five fault breccia samples from the ONKALO underground research facility, Olkiluoto, Eurajoki, S-W Finland. The XRD, SEM, and TEM studies and K-Ar analyses were done in John deLaeter Center in Mass Spectrometry at Curtin University, Perth, Western Australia. The <2 micron grain size fractions contain illite, chlorite, dickite, and quartz. All fractions had minor contamination phases comprising mainly of quartz but traces of K-feldspar contamination could be identified in all samples. The authigenic illite shows variable K concentrations. The illite contents of the ONK-PL68 and ONK-PL87 samples are the smallest. The K-Ar ages for the <2 micron fractions vary from ∼0.55 Ga to 1.38 Ga. The sample ONKPL68 yields a K-Ar age of 912 ± 18 Ma corresponding to a Neoproterozoic-Tonian age. This age can be roughly temporally linked with late events related to Sveconorwegian orogeny. Sample ONK-PL87 has a K-Ar age of 550 ± 11 Ma corresponding to a Neoproterozoic - Lower Cambrian age. The samples ONK-PL522 and ONK-PL901 sampled from the storage hall fault show identical K-Ar ages of 1385 ± 27 Ma and 1373 ± 27 Ma, respectively. These correspond to a Mesoproterozoic-Ectasian age related to Subjotnian or Postjotnian events. ONK-PL960 yields a K-Ar age of 1225 ± 24 Ma corresponding to a Mesoproterozoic-Ectasian age. This age agrees well with the ages from Postjotnian diabase dykes in W Finland. The 2-3 % detrital K-feldspar contamination in clay fractions increases the age. Especially for the youngest sample ONK-PL87, the effect may be geologically meaningful as after the correction the age clearly indicates Caledonian events. Moreover, the age for the low K sample ONKPL901 shifts to indicate Postjotnian diabase age. (orig.)

Dynamics of the deep red Fe3+ photoluminescence emission in feldspar

DEFF Research Database (Denmark)

Prasad, Amit Kumar; Jain, Mayank

2018-01-01

be exploited for site discrimination within a complex feldspar sample. The radiative relaxation in Fe3+ (4T1 → 6A1) is shown to be a dynamic process depending on whether the ion is excited using resonant or non-resonant transition. We suggest that during resonant excitation, the excited state of Fe3+ undergoes...

Application of pulsed OSL to the separation of the luminescence components from a mixed quartz/feldspar sample

DEFF Research Database (Denmark)

Denby, Phil M.; Bøtter-Jensen, L.; Murray, A.S.

2006-01-01

with a feldspar signal. We have developed instrumentation for the study of high-speed pulse stimulated OSL. Our system uses the standard blue/IR LED stimulation unit of a Riso reader (allowing stimulation pulses down to 1-2 mu s duration) and can thus be applied to the routine analysis of samples. Using...... that counts are only accumulated during a windowed period, reduces the feldspar signal to 1.6% of its original value relative to that of the quartz. (c) 2006 Elsevier Ltd. All rights reserved....

Further investigations into pulsed optically stimulated luminescence from feldspars using blue and green light

International Nuclear Information System (INIS)

Ankjaergaard, C.; Jain, M.; Kalchgruber, R.; Lapp, T.; Klein, D.; McKeever, S.W.S.; Murray, A.S.; Morthekai, P.

2009-01-01

The purpose of this paper is to investigate characteristics of luminescence signals resulting from pulsed optical stimulation of feldspars and thereby to understand the underlying processes giving rise to the signal. Fourteen different feldspar specimens were investigated using time-resolved optically stimulated luminescence (TR-OSL), and these signals can be mathematically described as a sum of 4 exponential components (a, b, c, d). The slowest component, d, increases with the duration of the light pulse as expected from the exponential model. The stimulation temperature dependence experiment suggests that the TR-OSL signal decay is governed by the recombination process and not by the excited state lifetime. Furthermore data from the TR-OSL signal dependence on stimulation time and preheat temperature suggest that the recombination process may not be a sum of exponentials, although the model cannot be rejected definitively.

FTIR measurements of OH in deformed quartz and feldspars of the South Tibetan Detachment, Greater Himalaya

Science.gov (United States)

Jezek, L.; Law, R. D.; Jessup, M. J.; Searle, M. P.; Kronenberg, A. K.

2017-12-01

OH absorption bands due to water in deformed quartz and feldspar grains of mylonites from the low-angle Lhotse Detachment (of the South Tibetan Detachment System, Rongbuk Valley north of Mount Everest) have been measured by Fourier Transform Infrared (FTIR) Spectroscopy. Previous microstructural studies have shown that these rocks deformed by dislocation creep at high temperature conditions in the middle crust (lower - middle amphibolite facies), and oxygen isotope studies suggest significant influx of meteoric water. OH absorption bands at 3400 cm-1 of quartz mylonites from the footwall of the Lhotse Detachment Fault are large, with the character of the molecular water band due to fluid inclusions in milky quartz. Mean water contents depend on structural position relative to the core of the Lhotse Detachment, from 1000 ppm (OH/106 Si) at 420 m below the fault to 11,350 (+/-1095) ppm near its center. The gradient in OH content shown by quartz grains implies influx of meteoric water along the Lhotse Detachment from the Tibetan Plateau ground surface to middle crustal depths, and significant fluid penetration into the extruding Himalayan slab by intergranular, permeable fluid flow processes. Feldspars of individual samples have comparable water contents to those of quartz and some are wetter. Large water contents of quartz and feldspar may have contributed to continued deformation and strain localization on the South Tibetan Detachment System. Dislocation creep in quartz is facilitated by water in laboratory experiments, and the water contents of the Lhotse fault rocks are similar to (and even larger than) water contents of quartz experimentally deformed during water weakening. Water contents of feldspars are comparable to those of plagioclase aggregates deformed experimentally by dislocation and diffusion creep under wet conditions.

Dependence of (anomalous) fading of infra-red stimulated luminescence on trap occupancy in feldspars

DEFF Research Database (Denmark)

Morthekai, P.; Jain, Mayank; Gach, Grzegorz

2013-01-01

Dose dependency of anomalous fading of infra-red stimulated luminescence (IRSL) from feldspars has been investigated using radiations of different ionisation qualities. The rate of fading of the IRSL signal after proton irradiation (9.4–30%/decade) is on an average almost twice compared...

Luminescence from potassium feldspars stimulated by infrared and green light

DEFF Research Database (Denmark)

Duller, G.A.T.; Bøtter-Jensen, L.

1993-01-01

A series of experiments are reported which investigate stimulated luminescence from potassium feldspar. The aim is to provide a basic phenomenological description of the response of the material to stimulation by heat, infrared radiation (875 DELTA 80 nm) and a green light wavelength band from 5 15...... to 560 nm. Two conclusions are drawn: firstly it is suggested that the majority of the trapped charge responsible for the infrared stimulated luminescence signal does not give rise to a thermoluminescence signal, and secondly that a large traction of the two optically stimulated luminescence signals...

Wadi Ladid Al-JI,Dan Alkali Feldspar Granites and Associated Pegmatites, North Eastern Eser, Egypt:Geology,Mineralogy and Radioactivity

International Nuclear Information System (INIS)

Abu Steet, A.A.; Ayoub, R.R.; Bakhit, A.F.

2013-01-01

This article deals with the geology, structure, mineralogy and radioactivity of the alkali feldspar granites at wadi Ladid al-Ji,dan, north Eastern Desert of Egypt. Geologically, the area consists mainly of alkali feldspar granites. These granites are medium to coarse grained, pink to red in colour and form numbers of moderate to relatively high elevated outcrops. These rocks are altered in some parts due to secondary processes especially along the fault zones and contacts. The area displays primary and secondary structures. Primary structures comprise layering, volcanic flows, vesicular tops of lavas and volcanic bombs. The secondary structures are represented by exfoliation, joints and faults. The granites are dissected by several sets of joints predominating in the N-S direction, dipping 84°-88° mainly to west; E-W direction, dipping 70°-75° mainly to south and NW-SE direction, dipping 80°-82° to SW direction. The majority of joints are tension ones. These tension joints are commonly filled with quartz, feldspars, epidote, iron oxides, manganese oxides and aplite. The studied area is dissected by major regional faults. Along the fault zones; the granites are marked by fault breccia and alteration features, especially silicification, hematitization, kaolinitization and chloritization. The area is cutting by faults trending mainly in N-S, NE-SW and NNW-SSE directions. The average uranium and thorium contents of the alkali feldspar granites are 12 and 23 ppm and reaches up to 36 and 37 ppm in the normal pegmatites. In the anomalous pegmatites the maximum values recorded are 91 and 72 ppm. Generally, the averages of uranium and thorium contents in the studied pegmatites are higher than that of the world and Egyptian uraniferous pegmatites. The high uranium content in alkali feldspar granites is related to the presence of some accessory minerals such as zircon, fluorite and apatite but the high uranium content in the pegmatites is related to the presence of

Developing a numerical simulation for fading in feldspar

International Nuclear Information System (INIS)

Larsen, A.; Greilich, S.; Jain, M.; Murray, A.S.

2009-01-01

Most models describing anomalous fading in feldspars are based on analytical solutions. As an alternative approach we present an entirely numerical model based on statistical sampling that simulates stepwise the charge creation/trapping and recombination in a given phosphor. We assume the number density of electrons and holes at any time to be equal, although the model is not bound to that assumption. The model is flexible enough to be used on any combination of geological and laboratory timescales and for any defined configuration of defects. Using this approach we observed reorganization of nearest-neighbor distances with time. The best agreement with experimental data is achieved if we assume the crystal to consist of small subvolumes (nanocrystals) only within which charge carriers are allowed to recombine.

Luminescence and ESR properties of Brazilian feldspars

International Nuclear Information System (INIS)

Bitencourt, J.F.S.; Silva, D.M.; Silva, P.H.; Kinoshita, A.; Munita, C.S.; Tatumi, S.H.

2006-01-01

The IRSL and TL responses of three different feldspar crystals have been analysed. TL measurements were taken in the ultraviolet UV (290-370nm) and the visible VIS (340-610nm) regions of the spectrum. For the UV region and for a natural sample, peaks were observed at 283, 287 and 310 deg. C for grey, white and pink crystals, respectively. For samples irradiated after prior preheating, it was noted that TL peaks occurred at about 200 deg. C for all the samples; irradiation with high doses above 500Gy induced the formation of one additional peak at 170 deg. C. The VIS region results were similar to those for the UV. ESR experiments have been developed to verify the influence of radiation and heat treatments on the centres and preliminary results showed great variation in the intensities of [TiO 4 ] - , Al-O - -Al and Fe 3+ centres

Testing the application of quartz and feldspar luminescence dating to MIS 5 Japanese marine deposits

DEFF Research Database (Denmark)

Thiel, Christine; Tsukamoto, Sumiko; Tokuyasu, Kayoko

2015-01-01

The applicability of both quartz and feldspar luminescence dating was tested on twenty-five samples from a marine succession now forming a coastal cliff at Oga Peninsula, Honshu Island, Japan. The quartz optically stimulated luminescence (OSL) signal shows thermal instability and linear modulated...

Limits to depletion of blue-green light stimulated luminescence in feldspars: Implications for quartz dating

DEFF Research Database (Denmark)

Jain, M.; Singhvi, A.K.

2001-01-01

stimulation curve of otherwise pure quartz. In this study, the functional relationship between the infra-red stimulated luminescence (IRSL) and BGSL of feldspars, (1) at different preheats, and (2) with IR bleaching at different stimulation temperatures and durations, is examined. The results suggest two trap...

Preparation and characterization of new dental porcelains, using K-feldspar and quartz raw materials. Effect of B2O3 additions on sintering and mechanical properties.

Science.gov (United States)

Harabi, Abdelhamid; Guerfa, Fatiha; Harabi, Esma; Benhassine, Mohamed-Tayeb; Foughali, Lazhar; Zaiou, Soumia

2016-08-01

The aim of this work was to determine the effect of temperature and boric oxide (B2O3) addition on sintering and mechanical properties of a newly developed dental porcelain (DP) prepared from local Algerian raw materials. Based on a preliminary work, the new selected composition was 75wt.% feldspar, 20wt.% quartz and 5wt.% kaolin. It was prepared by sintering the mixture at different temperatures (1100-1250°C). The optimum sintering conditions gave a relatively higher density (2.47g/cm(3)) and excellent mechanical properties. The three point flexural strength (3PFS) and Martens micro-hardness of dental porcelains were 149MPa and 2600MPa, respectively. This obtained 3PFS value is more than four times greater than that of hydroxyapatite (HA) value (about 37MPa) sintered under the same conditions. However, the sintering temperature was lowered by about 25 and 50°C for 3 and 5wt.% B2O3 additions, respectively. But, it did not improve furthermore the samples density and their mechanical properties. It has also been found that B2O3 additions provoke a glass matrix composition variation which delays the leucite formation during sintering. Copyright © 2016 Elsevier B.V. All rights reserved.

Modeling of the shape of infrared stimulated luminescence signals in feldspars

DEFF Research Database (Denmark)

Pagonis, Vasilis; Jain, Mayank; Murray, Andrew S.

2012-01-01

This paper presents a new empirical model describing infrared (IR) stimulation phenomena in feldspars. In the model electrons from the ground state of an electron trap are raised by infrared optical stimulation to the excited state, and subsequently recombine with a nearest-neighbor hole via...... corresponds to a fast rate of recombination processes taking place along the infrared stimulated luminescence (IRSL) curves. The subsequent decay of the simulated IRSL signal is characterized by a much slower recombination rate, which can be described by a power-law type of equation.Several simulations...

Zoning and exsolution in cumulate alkali feldspars from the eruption (12.9 Ka) of Laacher see volcano (Western Germany) as an indicator of time-scales and dynamics of carbonate-silicate unmixing

Science.gov (United States)

Sourav Rout, Smruti; Wörner, Gerhard

2017-04-01

Time-scales extracted from the detailed analysis of chemically zoned minerals provide insights into crystal ages, magma storage and compositional evolution, including mixing and unmixing events. This allows having a better understanding of pre-eruptive history of large and potentially dangerous magma chambers. We present a comprehensive study of chemical diffusion across zoning and exsolution patterns of alkali feldspars in carbonatite-bearing cognate syenites from the 6.3 km3 (D.R.E) phonolitic Laacher See Tephra (LST) eruption 12.9 ka ago. The Laacher See volcano is located in the Quaternary East Eifel volcanic field of the Paleozoic Rhenish Massif in Western Germany and has produced a compositionally variable sequence in a single eruption from a magma chamber that was zoned from mafic phonolite at the base to highly evolved, actively degassing phonolite magma at the top. Diffusion chronometry is applied to major and trace element compositions obtained on alkali feldspars from carbonate-bearing syenitic cumulates. Methods used were laser ablation inductively coupled plasma mass spectrometry (LA ICP-MS) in combination with energy-dispersive and wavelength-dispersive electron microprobe analyses (EDS & WDS-EMPA). The grey scale values extracted from multiple accumulations of back-scattered electron images represent the K/Na ratio owing to the extremely low concentrations of Ba and Sr (transition and phase separation). A distinctive uphill diffusive analysis is used specifically for the phase separation in the case of exsolution features (comprising of albite- and orthoclase-rich phases) in sanidines. The error values are aggregates of propagated error through calculations and the uncertainty in temperature values. Trace element compositional data of distinct feldspar compositions that are assumed to have grown before and after silicate-carbonate unmixing are used to estimate partition coefficients between carbonate and silicate melt. The resulting values correlate

Development of cataclastic foliation in deformation bands in feldspar-rich conglomerates of the Rio do Peixe Basin, NE Brazil

Science.gov (United States)

Nicchio, Matheus A.; Nogueira, Francisco C. C.; Balsamo, Fabrizio; Souza, Jorge A. B.; Carvalho, Bruno R. B. M.; Bezerra, Francisco H. R.

2018-02-01

In this work we describe the deformation mechanisms and processes that occurred during the evolution of cataclastic deformation bands developed in the feldspar-rich conglomerates of the Rio do Peixe Basin, NE Brazil. We studied bands with different deformation intensities, ranging from single cm-thick tabular bands to more evolved clustering zones. The chemical identification of cataclastic material within deformation bands was performed using compositional mapping in SEM images, EDX and XRD analyses. Deformation processes were identified by microstructural analysis and by the quantification of comminution intensity, performed using digital image processing. The deformation bands are internally non homogeneous and developed during five evolutionary stages: (1) moderate grain size reduction, grain rotation and grain border comminution; (2) intense grain size reduction with preferential feldspar fragmentation; (3) formation of subparallel C-type slip zones; (4) formation of S-type structures, generating S-C-like fabric; and (5) formation of C‧-type slip zones, generating well-developed foliation that resembles S-C-C‧-type structures in a ductile environment. Such deformation fabric is mostly imparted by the preferential alignment of intensely comminuted feldspar fragments along thin slip zones developed within deformation bands. These processes were purely mechanical (i.e., grain crushing and reorientation). No clays or fluids were involved in such processes.

Dating Last Interglacial Coastal Systems Using New Feldspar Luminescence Technologies

Science.gov (United States)

Lamothe, M.

2017-12-01

The recent explosion in new luminescence dating technologies offers new opportunities to explore Quaternary marine coastal facies and landforms. However, tectonic and climatic processes controlling the development of Pleistocene coastal lithosomes are commonly obscured by their poorly constrained geological age. Luminescence dating of feldspar probes one order of magnitude deeper into geological time than radiocarbon and more than 5 times the current age range of quartz optically-stimulated luminescence, routinely used in luminescence dating. However, feldspar luminescence stimulated by infrared photons (eg IRSL) is hampered by anomalous fading. Successful correction methods developed by us over the last 15 years did produce sound chronologies but the fading-corrected ages carried large uncertainties. New approaches initiated by other laboratories, mainly in Europe, have isolated high temperature post-IRSL luminescence as this signal seems to be only slightly affected by fading. However, the gain in stability seems to be lessened due to bleachibility issues, generating age overestimations. We developed a novel protocol known as post-isothermal IRSL dating (Pit-IR) that focuses on a dual system of luminescence signals, probing low (50C) and medium (225C) temperature IRSL signals following isothermal treatments of various intensities. These protocols have been tested on Last interglacial coastal sediments in strikingly different GIA contexts along the Atlantic coastal areas of SE USA as well as from Morocco, Brazil and LIG sites in the Mediterranean basin. A systematic analysis of these results would suggest that a) falling-stages sequences are more commonly preserved as the OSL/IRSL ages are preferentially dating from the end of the MIS5e high stand and b) MIS5a marine sediments may be detectable away from areas generally thought to be affected by peripheral bulge collapse.

The release of iron-bearing minerals and dissolution of feldspars by heterotrophic bacteria of Bacillus species

Czech Academy of Sciences Publication Activity Database

Štyriaková, I.; Štyriak, I.; Galko, I.; Hradil, David; Bezdička, Petr

2003-01-01

Roč. 47, č. 1 (2003), s. 20-26 ISSN 0862-5468 Grant - others:AV SR(SK) 2/2107/22; GA SR(SK) 73/2000 Institutional research plan: CEZ:AV0Z4032918 Keywords : bioleaching * feldspars * Bacillus Subject RIV: CA - Inorganic Chemistry Impact factor: 0.449, year: 2003

Accumulated phenocrysts and origin of feldspar porphyry in the Chanho area, western Yunnan, China

Science.gov (United States)

Xu, Xing-Wang; Jiang, Neng; Yang, Kai; Zhang, Bao-Lin; Liang, Guang-He; Mao, Qian; Li, Jin-Xiang; Du, Shi-Jun; Ma, Yu-Guang; Zhang, Yong; Qin, Ke-Zhang

2009-12-01

The No. 1 feldspar porphyry in the Chanho area, western Yunnan, China is characterized by the development of deformed glomeroporphyritic aggregates (GA) that contain diagnostic gravity settling textures. These textures include interlocking curved grain boundaries caused by compaction, bent twins, and arch-like structures. The GAs are accumulated phenocrysts (AP) and antecrysts. The unstable textural configurations such as extensive penetrative microfractures that are restricted within the AP and fractured cores of zircon grains, all suggest that the GAs are transported fragments of fractured cumulates that formed in a pre-emplacement magma chamber rather than form in situ at the current intrusion site. Compositions of minerals and melt as represented by different mineral aggregates formed at various stages of the magmatic process and their relations to the composition of porphyry bodies in the Chanho area indicate that the porphyritic melt for the No. 1 feldspar porphyry experienced two stages of melt mixing. Pulses of potassic melt flowed into a pre-emplacement magma chamber and mixed with crystallizing dioritic magma containing phenocrysts resulted in the first hybrid alkaline granitic melt. The mixing caused denser phenocrysts to settle and aggregate to form cumulates. Secondly, new dioritic melt was injected into the magma chamber and was mixed with the previously formed hybrid alkaline granitic melt to produce syenitic melt. Geochron data, including U-Pb age of zircon and 39Ar/ 40Ar age of hornblende and oligoclase phenocrysts, indicate that hornblende and oligoclase phenocrysts, as well as the core of zircon grains, were antecrysts that formed in a number of crystallization events between 36.3 and 32.78 Ma. Gravity settling of phenocrysts took place at about 33.1 to 32.78 Ma and melts with deformed GAs were transported upwards and emplaced into the current site at 32 Ma. Results of this research indicate that the No. 1 feldspar porphyry was a shallow

The high-K calc-alkalic Serra da Lagoinha batholith, States of Ceara and Paraiba (Northeastern region, Brazil): coexistence and mixing of dioritic and quartz monzonitic to granitic magmas

International Nuclear Information System (INIS)

Mariano, Gorki; Sobreira, Mauricio de Nassau de Mattos

1999-01-01

The Serra da Lagoinha batholith (SLB) has an outcrop area of 200 km 2 is located in the Borborema Province, northeastern Brazil, and intrudes schists and phylites at the border of the Cachoeirinha-Salgueiro fold belt. Its southern border is defined by a major curved NE-SW sinistral transcurrent shear zone (Boqueirao dos Cochos) connecting the E-W dextral shear zones of Patos to the north and Pernambuco to the south. The SLB has three lithologic domains: the felsic porphyritic domain composed of K-feldspar megacrystic monzonitic, quartz monzonitic, quartz monzodioritic, granitic to granodioritic rocks; the k-dioritic domain composed of biotite (quartz) dioritic to tonalitic rocks and the hybrid domain composed of monzonitic and biotite (quartz) dioritic rocks. Field evidences show that these lithologic domains were produced by the coexistence and mixing of K-diorites with potassic monzonitic to granodioritic magmas. The mafic rocks are enriched in Nb, ba, and Zr and LREE in relation to the felsic porphyritic rocks. The REE patterns for mafic and felsic rocks are similar and enriched in the LREE in relation to the HREE, with (La/Yb) N varying from 22.43 to 36.10 for the felsic and from 27.21 to 58.87 for the mafic rocks. Al Τ in amphibole geobarometer (Hollister 1987) shows that amphibole crystallization in the SLB occurred at approximately 4.5 kbar. Geothermometry based on the coexistence of amphibole and plagioclase, (Blundy and Holland 1990) gives a temperature of 742 deg C. Whole rock Oxygen isotope data showed average values for mafic of δ 18 O = + 7.9 permil SMOW and for the felsic rocks of δ 18 O + 9.1 permil SMOW , suggesting either isotopic equilibrium of coexistent magmas of distinct sources or crystal fractionation process controlling the evolution from mafic to felsic rocks. Quartz corrected values for the felsic porphyritic rocks averaged δ 18 O = + 9.2 permil, suggesting that the whole rock data represent magmatic values. Sm-Nd systematics show T

Stoneware tile manufacturing using rice straw ash as feldspar replacement; Fabricacion de gres porcelanico empleando ceniza de tamo de arroz en sustitucion del feldespato

Energy Technology Data Exchange (ETDEWEB)

Alvaro Guzman, A.; John Torres, L.; Martha Cedeno, V.; Silvio Delvasto, A.; Vicente Amigo, B.; Enrique Sanchez, V.

2013-07-01

In this research are presented the results of using rice straw ash (RSA) in low proportions as substitute of feldspar for manufacturing stoneware tiles. Specimens of semidry triaxial mixtures, where feldspar was substituted for different percentages (25 % and 50 %) of RSA, were prepared by uniaxial pressing, followed by drying and sintering. Physical and mechanical properties of sintered bodies were evaluated. Porcelain stoneware tile specimens C0 and CF25 reached bending strength and water absorption values were in accordance with standard ISO 13006 (Annex G, BIa) ( {>=} 35 MPa and {<=} 0.5 %, respectively). However, in porcelain stoneware tile specimens CF50 due to bloating phenomenon was not possible obtain commercial tiles in accordance with standard ISO 13006. By using Scanning Electron Microscopy (SEM) needles of primary and secondary mullite were identified in a vitreous phase; and by using X-Ray Diffraction (XRD) mullite and quartz phases were identified. It was concluded that feldspar can be substituted positively by RSA in stoneware tile pastes. (Author)

Determination of K-40 in croquettes

International Nuclear Information System (INIS)

Escalona L, M. I.; Campillo R, G. E.; Vega C, H. R.; Garcia S, E.

2017-10-01

The health of the pets depends on several factors; one of the most important is the quality of their diet. The dog (Canis lupus familiaris) is a carnivorous mammal of the family of canines that is part of the most accepted pets. For the feeding of these pets is common to use industrial foods such as croquettes that offer many advantages, however they also contribute to the intake of radioisotopes that can affect their health. Potassium is an essential element for health, naturally there are 3 isotopes: K-39, K-40 and K-41. The K-40 is radioactive with 1,248 x 10 9 years of half-life that when decaying emits beta particles and photons of 1.42 MeV. In this work, potassium 40 activity was determined in croquette brands: Dog Chow, Canine Power and Exceed; KCl was used as a standard and dehydrated pea was used as control. The croquettes and peas were ground and weighed 160 grams of each sample, of KCl and pea, which were placed in Marinelli containers that were measured with a spectrometric system for γ rays and with a Nal(Tl) scintillator of 7.62 cm in diameter and 7.62 cm in height. It was found that the average activity of K-40 in all the measured brands is 5.0 ± 0.3 Bq per croquettes gram. (Author)

Study of sensitivity change of OSL signals from quartz and feldspars as a function of preheat temperature

DEFF Research Database (Denmark)

Jungner, H.; Bøtter-Jensen, L.

1994-01-01

and as a result, the equivalent dose (ED) would be underestimated. A study of sensitivity changes in feldspars and quartz was carried out with emphasis on the effect of preheat and annealing on the OSL signal. Measurement results obtained are presented, and possible elimination of errors in dating caused...

Electrons in feldspar II: A consideration of the influence of conduction band-tail states on luminescence processes

DEFF Research Database (Denmark)

Poolton, H.R.J.; Ozanyan, K.B.; Wallinga, J.

2002-01-01

consider what influence the band tails have on the luminescence properties of feldspar, where electrons travel through the sample prior to recombination. The work highlights the dominant role that 0.04-0.05-eV phonons play in both the luminescence excitation and emission processes of these materials...

How the Emitted Size Distribution and Mixing State of Feldspar Affect Ice Nucleating Particles in a Global Model

Science.gov (United States)

Perlwitz, J. P.; Fridlind, A. M.; Knopf, D. A.; Miller, R. L.; Pérez García-Pando, C.

2017-12-01

The effect of aerosol particles on ice nucleation and, in turn, the formation of ice and mixed phase clouds is recognized as one of the largest sources of uncertainty in climate prediction. We apply an improved dust mineral specific aerosol module in the NASA GISS Earth System ModelE, which takes into account soil aggregates and their fragmentation at emission as well as the emission of large particles. We calculate ice nucleating particle concentrations from K-feldspar abundance for an active site parameterization for a range of activation temperatures and external and internal mixing assumption. We find that the globally averaged INP concentration is reduced by a factor of two to three, compared to a simple assumption on the size distribution of emitted dust minerals. The decrease can amount to a factor of five in some geographical regions. The results vary little between external and internal mixing and different activation temperatures, except for the coldest temperatures. In the sectional size distribution, the size range 2-4 μm contributes the largest INP number.

How the Emitted Size Distribution and Mixing State of Feldspar Affect Ice Nucleating Particles in a Global Model

Science.gov (United States)

Perlwitz, Jan P.; Fridlind, Ann M.; Knopf, Daniel A.; Miller, Ron L.; García-Pando, Carlos Perez

2017-01-01

The effect of aerosol particles on ice nucleation and, in turn, the formation of ice and mixed phase clouds is recognized as one of the largest sources of uncertainty in climate prediction. We apply an improved dust mineral specific aerosol module in the NASA GISS Earth System ModelE, which takes into account soil aggregates and their fragmentation at emission as well as the emission of large particles. We calculate ice nucleating particle concentrations from K-feldspar abundance for an active site parameterization for a range of activation temperatures and external and internal mixing assumption. We find that the globally averaged INP concentration is reduced by a factor of two to three, compared to a simple assumption on the size distribution of emitted dust minerals. The decrease can amount to a factor of five in some geographical regions. The results vary little between external and internal mixing and different activation temperatures, except for the coldest temperatures. In the sectional size distribution, the size range 24 micrometer contributes the largest INP number.

Petrological studies of plutonic rocks of Ecuador

International Nuclear Information System (INIS)

Aly, S.

1980-01-01

The feldspars of many tonalitic plutonic rocks in the coastal regions and West Andean regions are zoned. This leads to the conclusion that they are relatively flat intrusions and to some extent transition rocks in the subvulcanite direction. This is in accordance with the genetic and chronological relationship between plutonites and the surrounding vulcanites of the Basic Igreous Complex (BIC). The composition of representative minerals, e.g. alkali feldspar, plagioclase feldspar, biotite, chlorite, and amphibole has been determined as well as the age of plutonite samples by the K/Ar dating method. (DG) [de

Optical excitation processes in the near band-edge region of KAlSi₃O₈ and NaAlSi₃O₈ feldspar

DEFF Research Database (Denmark)

Poolton, N.R.J.; Mauz, B.; Lang, A.

2006-01-01

-stimulated phosphorescence and energy-dependent photo-transferred optically stimulated luminescence. The photo-transferred OSL confirms the bandgap energy of alkali feldspars to be 7.7eV at 10K, and highlights the role played by a dominant optically active defect 4.4 eV below the conduction band, associated with blue......)) yielding a characteristically narrow feature at 4.61 eV: significantly, excitation to this level allows photo-transferred OSL to take place, a process that is not obviously identifiable with the other transitions of the set. The conclusion of the work is that synchrotron-based luminescence methods can...

Filling material for a buried cavity in a collapse area using light-weighted foam and active feldspar

Science.gov (United States)

Cho, Jin Woo; Lee, Ju-hyoung; Kim, Sung-Wook; Choi, Eun-Kyeong

2017-04-01

Concrete which is generally used as filling material for a buried cavity has very high strength but significantly high self-load is considered its disadvantage. If it is used as filling material, the second collapse due to additional load, causing irreversible damage. If light-weighted foam and active feldspar are used to solve this problem, the second collapse can be prevented by reducing of self-load of filling material. In this study, the specimen was produced by mixing light-weighted foam, active feldspar and cement, and changes in the density, unconfined compressive strength and hydraulic conductivity were analyzed. Using the light-weighted foam could enable the adjustment of density of specimen between 0.5 g/cm3 and 1.7 g/cm3, and if the mixing ratio of the light-weighted foam increases, the specimen has more pores and smaller range of cross-sectional area. It is confirmed that it has direct correlation with the density, and if the specimen has more pores, the density of the specimen is lowered. The density of the specimen influences the unconfined compressive strength and the hydraulic conductivity, and it was also confirmed that the unconfined compressive strength could be adjusted between 0.6 MPa and 8 MPa and the hydraulic conductivity could be adjusted between 10-9cm/sec and 10-3cm/sec. These results indicated that we can adjust unconfined compressive strength and hydraulic conductivity of filling materials by changing the mixing amount of lightweight-weighted foam according to the requirements of the field condition. Keywords: filling material, buried cavity, light-weighted foam, feldspar Acknowledgement This research was supported by a Grant from a Strategic Research Project (Horizontal Drilling and Stabilization Technologies for Urban Search and Rescue (US&R) Operation) funded by the Korea Institute of Civil Engineering and Building Technology.

Major zircon megacryst suites of the Indo-Pacific lithospheric margin (ZIP) and their petrogenetic and regional implications

Science.gov (United States)

Sutherland, Lin; Graham, Ian; Yaxley, Gregory; Armstrong, Richard; Giuliani, Gaston; Hoskin, Paul; Nechaev, Victor; Woodhead, Jon

2016-04-01

Zircon megacrysts (± gem corundum) appear in basalt fields of Indo-Pacific origin over a 12,000 km zone (ZIP) along West Pacific continental margins. Age-dating, trace element, oxygen and hafnium isotope studies on representative zircons (East Australia-Asia) indicate diverse magmatic sources. The U-Pb (249 to 1 Ma) and zircon fission track (ZFT) ages (65 to 1 Ma) suggest thermal annealing during later basalt transport, with < 1 to 203 Ma gaps between the U-Pb and ZFT ages. Magmatic growth zonation and Zr/Hf ratios (0.01-0.02) suggest alkaline magmatic sources, while Ti—in—zircon thermometry suggests that most zircons crystallized within ranges between 550 and 830 °C. Chondrite-normalised multi-element plots show variable enrichment patterns, mostly without marked Eu depletion, indicating little plagioclase fractionation in source melts. Key elements and ratios matched against zircons from magmatic rocks suggest a range of ultramafic to felsic source melts. Zircon O-isotope ratios (δ18O in the range 4 to 11‰) and initial Hf isotope ratios (ɛHf in the range +2 to +14) encompass ranges for both mantle and crustal melts. Calculated Depleted Mantle (TDM 0.03-0.56 Ga) and Crustal Residence (0.20-1.02 Ga) model ages suggest several mantle events, continental break-ups (Rodinia and Gondwana) and convergent margin collisions left imprints in the zircon source melts. East Australian ZIP sites reflect prolonged intraplate magmatism (~85 Ma), often during times of fast-migrating lithosphere. In contrast, East Asian-Russian ZIP sites reflect later basaltic magmatism (<40 Ma), often linked to episodes of back-arc rifting and spreading, slow-migrating lithosphere and slab subduction.

BPM Offset Determination by Sinusoidal Quadrupole K-modulation

CERN Document Server

Baer, T; Wenninger, J

2011-01-01

To ensure an adequate orbit steering that maximizes the machine aperture, a good knowledge of the BPM measurement offsets is crucial. During this MD, a sinusoidal k-modulation of individually powered quadrupoles was performed to determine the offsets of the nearby BPMs. An accuracy of 10µm for the determination of the absolute beam position is reached.

Photoionization of radiation-induced traps in quartz and alkali feldspars.

Science.gov (United States)

Hütt, G; Jaek, I; Vasilchenko, V

2001-01-01

For the optimization of luminescence dating and dosimetry techniques on the basis of the optically stimulated luminescence, the stimulation spectra of quartz and alkali feldspars were measured in the spectral region of 250-1100 nm using optically stimulated afterglow. Optically stimulated luminescence in all studied spectral regions is induced by the same kind of deep traps, that produce thermoluminescence in the regions of palaeodosimetric peaks for both minerals. The mechanism for photoionization of deep traps was proposed as being due to delocalization of the excited state of the corresponding lattice defects. The excited state overlaps the zone states; i.e. is situated in the conduction band. Because of the high quantum yield of deep electron trap ionization in the UV spectral region, the present aim was to study the possibility of using UV-stimulation for palaeodose reconstruction.

Photoionization of radiation-induced traps in quartz and alkali feldspars

International Nuclear Information System (INIS)

Huett, G.; Jaek, I.; Vasilchenko, V.

2001-01-01

For the optimization of luminescence dating and dosimetry techniques on the basis of the optically stimulated luminescence, the stimulation spectra of quartz and alkali feldspars were measured in the spectral region of 250-1100 nm using optically stimulated afterglow. Optically stimulated luminescence in all studied spectral regions is induced by the same kind of deep traps, that produce thermoluminescence in the regions of palaeodosimetric peaks for both minerals. The mechanism for photoionization of deep traps was proposed as being due to delocalization of the excited state of the corresponding lattice defects. The excited state overlaps the zone states; i.e. is situated in the conduction band. Because of the high quantum yield of deep electron trap ionization in the UV spectral region, the present aim was to study the possibility of using UV-stimulation for palaeodose reconstruction

Photoionization of radiation-induced traps in quartz and alkali feldspars

Energy Technology Data Exchange (ETDEWEB)

Huett, G. E-mail: hutt@pdos.gi.ee; Jaek, I.; Vasilchenko, V

2001-01-15

For the optimization of luminescence dating and dosimetry techniques on the basis of the optically stimulated luminescence, the stimulation spectra of quartz and alkali feldspars were measured in the spectral region of 250-1100 nm using optically stimulated afterglow. Optically stimulated luminescence in all studied spectral regions is induced by the same kind of deep traps, that produce thermoluminescence in the regions of palaeodosimetric peaks for both minerals. The mechanism for photoionization of deep traps was proposed as being due to delocalization of the excited state of the corresponding lattice defects. The excited state overlaps the zone states; i.e. is situated in the conduction band. Because of the high quantum yield of deep electron trap ionization in the UV spectral region, the present aim was to study the possibility of using UV-stimulation for palaeodose reconstruction.

$K^{0} \\leftrightharpoons \\overline{K}^0$ transitions monitored by strong interactions a new determination of the $K_{L} - K_{S}$ mass difference

CERN Document Server

Angelopoulos, Angelos; Backenstoss, Gerhard; Bargassa, P; Behnke, O; Benelli, A; Bertin, V; Blanc, F; Bloch, P; Carlson, P J; Carroll, M; Cawley, E; Chertok, M B; Danielsson, M; Dejardin, M; Derré, J; Ealet, A; Eleftheriadis, C; Fetscher, W; Fidecaro, Maria; Filipcic, A; Francis, D; Fry, J; Gabathuler, Erwin; Gamet, R; Gerber, H J; Go, A; Haselden, A; Haymen, P J; Henry-Coüannier, F; Hollander, R W; Jon-And, K; Kettle, P R; Kokkas, P; Kreuger, R; Le Gac, R; Leimgruber, F; Mandic, I; Manthos, N; Marel, Gérard; Mikuz, M; Miller, J; Montanet, François; Müller, A; Nakada, Tatsuya; Pagels, B; Papadopoulos, I M; Pavlopoulos, P; Polivka, G; Rickenbach, R; Roberts, B L; Ruf, T; Sakelliou, L; Schäfer, M; Schaller, L A; Schietinger, T; Schopper, A; Tauscher, Ludwig; Thibault, C; Touchard, F; Touramanis, C; van Eijk, C W E; Vlachos, S; Weber, P; Wigger, O; Wolter, M; Zavrtanik, D; Zimmerman, D

2001-01-01

The CPLEAR set-up (modified) has been used to determine the K/sub L/- K/sub S/ mass difference by a method where neutral-kaon strangeness oscillations are monitored through kaon strong interactions, rather than semileptonic decays, thus requiring no assumptions on CPT invariance for the decay amplitudes. The result, Delta m= (0.5343+or-0.0063/sub stat/+or-0.0025/sub syst/)*10/sup 10/ h(cross) /s, provides a valuable input for CPT tests. (22 refs).

The dependence of orange-red IRSL decay curves of potassium feldspars on sample temperature

International Nuclear Information System (INIS)

Fattahi, Morteza

2004-01-01

This paper presents the effects of stimulation temperature on the infrared stimulated orange-red (600-650 nm) luminescence emission (orange-red infrared simulated luminescence (IRSL)) in potassium feldspar. Investigations explore the relationship between initial (0-2 s), integral (0-100 s), net initial (0-2 s less background over 2 s), net integral (0-100 s less background over 100 s) and last 2 s of the orange-red IRSL signals obtained for 100 s versus stimulation temperature (20-460 degree sign C) on both unpreheated and preheated samples. In the potassium feldspar sample examined, competition effects, including thermal enhancement, depletion and possibly quenching affect the orange-red IRSL signals measured. Observed effects (e.g., thermal enhancement, thermal activation energy and the decay rate) over the temperature range 20-120 degree sign C may be explained by tunnelling luminescence processes, IR transitions to the conduction band following excitations from ground state of electron trap by acquiring thermal energy from the lattice and or the random-walk band-tail model. Preheating prior to orange-red IRSL and Thermoluminescence (TL) measurements provides evidence that there are both shallow and deep traps responsible for low- and high-temperature orange-red IRSL and TL peaks. The effects of both preheating and IR bleaching on the orange-red thermally stimulated luminescence (red emission during thermoluminescence, RTL) provide evidence that bleached RTL traps have no significant contribution in the production of orange-red IRSL signals

Yellow stimulated luminescence from potassium feldspar: Observations on its suitability for dating

International Nuclear Information System (INIS)

Lauer, T.; Krbetschek, M.; Mauz, B.; Frechen, M.

2012-01-01

Yellow stimulated luminescence (Y-OSL) is the light detected from potassium-rich feldspars at 410 nm under stimulation by a yellow light source emitting 590 nm. The investigation of this study aimed at understanding basic luminescence physics of Y-OSL in order to assess the suitability of the technique for dating. The Y-OSL signal properties tested were signal intensity, thermal assistance, thermal stability, sensitivity to daylight and the suitability of a single aliquot regenerative (SAR) protocol to be employed for equivalent dose (D e ) estimation. D e measurements were conducted on samples of Holocene, last glacial and Tertiary age. The tests were undertaken on sedimentary feldspar separates extracted from aeolian, fluvial and coastal deposits. Results from experiments show that the signal intensity increases by measuring Y-OSL at elevated temperature suggesting thermal assistance characteristics similar to infrared stimulated luminescence (IRSL). The yellow stimulated signal remains unaffected by preheat temperatures up to ∼200 °C suggesting higher thermal stability than the IRSL signal. The Y-OSL signal is less light sensitive than the IRSL signal and D e residuals obtained from modern samples are up to 7 Gy indicating suitability of the technique for ‘older’ and well-bleached sediments. The dose recovery tests successfully recovered the given dose if the specific light sensitivity of Y-OSL is taken into account. For every sample Y-OSL D e values obtained by a single aliquot regenerative dose protocol (SAR) are higher than those obtained by an IRSL SAR approach. From these results we infer high thermal stability and a minimal anomalous fading of the Y-OSL signal. We conclude that Y-OSL has a high potential to date Quaternary sediments that were sufficiently bleached in nature.

First determination of CP violation parameters from K0-anti K0 decay asymmetry

International Nuclear Information System (INIS)

Adler, R.; Backenstoss, G.; Eckart, B.; Felder, C.; Pagels, B.; Polivka, G.; Rickenbach, R.; Santoni, C.; Tauscher, L.; Troester, D.A.; Alhalel, T.; Ealet, A.; Fassnacht, P.; Geralis, T.; Montanet, F.; Pelucchi, F.; Angelopoulos, A.; Apostolakis, A.; Rozaki, E.; Sakeliou, L.; Sarigiannis, K.; Aslanides, E.; Bee, C.P.; Gamet, R.; Bennet, J.; Cawley, E.; Dodgson, M.; Fry, J.R.; Gabathuler, E.; Harrison, P.F.; Hayman, P.J.; Maley, P.; Sacks, L.; Sanders, P.; Vlachos, S.; Bienlein, J.K.; Fetscher, W.; Gerber, H.J.; Gumplinger, P.; Ruf, T.; Schaefer, M.; Weber, P.; Witzig, C.; Bloch, P.; Fidecaro, M.; Heyes, W.G.; Pavlopoulos, P.; Schopper, A.; Bula, C.; Kettle, P.R.; Nakada, T.; Burgun, G.; Chardin, G.; Dejardin, M.; Derre, J.; Duclos, J.; Faure, J.L.; Francis, D.; Garreta, D.; Guyot, C.; Kochowski, C.; Schune, P.; Yeche, C.; Carlson, P.; Fuglesang, C.; Jansson, K.; Jon-And, K.; Kerek, A.; Szilagyi, S.; Carvalho, J.; Cobbaert, H.; Ferreira-Marques, R.; Onofre, A.; Pinto da Cunha, J.; Policarpo, A.; Beveren, E. van; Charalambous, S.; Chardalas, M.; Dedoussis, S.; Touramanis, C.; Dousse, J.C.; Faravel, L.; Johner, H.U.; Kern, J.; Schaller, L.; Filipcic, A.; Mikuz, M.; Seljak, U.; Zavrtanik, D.; Go, A.; Lawry, T.; Miller, J.P.; Roberts, B.L.; Varner, G.; Zimmerman, D.; Hollander, R.W.; Kreuger, R.; Postma, H.; Putte, M. van den; Eijk, C.W.E. van; Kokkas, P.; Manthos, N.; Triantis, F.; Le Gac, R.; Thibault, C.; Touchard, F.; Machado, E.; Marel, G.

1992-01-01

We report the first determination of CP violation parameters from particle-antiparticle asymmetry in the decay of neutral kaons into two charged pions. Observation of such an asymmetry is direct proof of CP violation. A fit to the asymmetry enabled a determination of the parameter η +- to be made, yielding the result vertical strokeη +- vertical stroke=[2.32±0.14(stat.)±0.03(syst.)]x10 -3 and φ +- =42.3deg±4.4deg(stat.)±0.4deg(syst.), with an additional uncertainty of ±1.0deg due to the error on the present published value of Δm, the K L 0 -K S 0 mass difference. The magnitudes of both statistical and systematic errors will be significantly reduced in the future. (orig.)

Exogenous and endogenous determinants of vitamin K status in cystic fibrosis.

Science.gov (United States)

Krzyżanowska, Patrycja; Pogorzelski, Andrzej; Skorupa, Wojciech; Moczko, Jerzy; Grebowiec, Philip; Walkowiak, Jarosław

2015-07-10

Cystic fibrosis (CF) patients are at high risk for vitamin K deficiency. The effects of vitamin K supplementation are very ambiguous. Therefore, we aimed to define the determinants of vitamin K deficiency in a large cohort of supplemented - 146 (86.9%) and non-supplemented - 22 (13.1%) CF patients. Vitamin K status was assessed using prothrombin inducted by vitamin K absence (PIVKA-II) and undercarboxylated osteocalcin (u-OC). The pathological PIVKA-II concentration (≥ 2 ng/ml) and abnormal percentage of osteocalcin (≥ 20%) were found in 72 (42.8%) and 60 (35.7%) subjects, respectively. We found that liver involvement, diabetes, and glucocorticoid therapy were potential risk factors for vitamin K deficiency. Pathological concentrations of PIVKA-II occurred more frequently in patients with pancreatic insufficiency and those who have two severe mutations in both alleles of the CFTR gene. Pathological percentage of u-OC was found more frequently in adult CF patients and those not receiving vitamin K. However, it seems that there are no good predictive factors of vitamin K deficiency in CF patients in everyday clinical care. Early vitamin K supplementation in CF patients seems to be warranted. It is impossible to clearly determine the supplementation dose. Therefore, constant monitoring of vitamin K status seems to be justified.

Selective intake of potassium from K-bearing silicate minerals by sunflower and upland rice inferred from Eu anomaly. Implication for weathering as a direct consequence of plant physiology

International Nuclear Information System (INIS)

Akagi, Tasuku; Saito, Sakura; Watanabe, Shin-ichi; Sugiyama, Megumi; Ae, Noriharu

2006-01-01

Two crops (sunflower and upland rice) cultivated using three K-bearing minerals and KCl by Sugiyama and Ae (2000) were analyzed for rare earth elements (REEs). The two crops had been reported by them to general more available silica in soil (especially in the case of sunflower) and absorbed silica in plants (especially in the case of upland rice) than that available originally in soil. The K-bearing minerals included biotite, muscovite, and K-feldspar. The REE patterns of individual crop specimens exhibited different extents of Eu anomaly; upland rice exhibited more varying extent of Eu anomaly than sunflower. It is inferred that REEs released from the K-bearing minerals had a longer contact with soil in the case of sunflower than in the case of upland rice. By the scrutiny of the extent of the Eu anomaly, it was found that upland rice took in K and REEs from all the K-bearing minerals, including hardly-soluble feldspar. Eu anomaly can be a good proxy of sources of inorganic nutrients in plants as well as of the directness of absorption of the nutrients. When the present results are viewed from a different angle, they endorse that plant-induced weathering is equivalent to physiological action of plants. (author)

Determination of k0-factors of short-lived nuclides and application of k0-NAA to selected trace elements

International Nuclear Information System (INIS)

Acharya, R.; Holzbecher, J.; Chatt, A.

2012-01-01

As part of the standardization program of k 0 -based NAA (k 0 -NAA) methods at the Dalhousie University SLOWPOKE-2 reactor (DUSR) facility, the k 0 -factors of 15 analytically important short-lived nuclides (half-life 197 Au). The elemental standards used were prepared mostly from their primary standard solutions. The samples were irradiated in both inner and outer pneumatic sites of the DUSR facility and counted using an HPGe-detector coupled to an ORTEC’s digital gamma-ray spectrometer. The k 0 -factors determined using both inner and outer irradiation sites were found to be within ±5% with respect to either recommended or literature values in most cases. The Z-score values at 95% confidence level were found to be in the range of ±0.03–1.6. The k 0 -NAA method was applied to three different NIST standard reference materials (SRMs) and concentrations of six elements, namely Ag, F, Hf, Rb, Sc, and Se were determined using their short-lived nuclides. The concentrations of these elements were also determined by relative NAA method for comparison purposes.

Petrology and isotope systematics of magma mushes: some porphyritic granitoids of northeastern Brazil

International Nuclear Information System (INIS)

McMurry, J.; Long, L.E.; Sial, A.N.

1987-01-01

More than 80 coarsely porphyritic granitoid plutons with K-feldspar megacrysts (Itaporanga-type granites) intrude metamorphic rocks of Northeastern Brazil. Textural evidence for filter pressing and flow foliation indicates that these bodies were emplaced as viscous, crystal-laden mushes. A representative Itaporanga-type pluton, the Monte das Gameleiras intrusion, consists of a variety of rock types with SiO 2 ranging from 49.5 to 71.6 weight percent. Chemically and petrographically, this hornblende-bearing pluton has I-type characteristics with some S-type affinities. Whole-rock oxygen isotope data are in keeping with the distribution of δO 18 , for unaltered granitic rocks. Similarly, REE data suggest a single magmatic process, at least for the more felsic rock types, without post-intrusive effects. A 5-point, whole-rock Rb-Sr isochron for the Monte das Gameleiras pluton gives t = 511 ± 26 Ma andan initial, 87 Sr/ 86 Sr = 0.7099 ± 0.0004. This is contrasted with disparate ages calculated from texturally similar bodies such as the Fazenda Nova pluton, for which a 5-point whole-rock isochron gives t = 630 ± 24 Ma with initial 87 Sr/ 86 Sr = 0.7065 ± 0.0005, and the type locality Itaporanga pluton, for which a 6-point isochron gives t= 625 ± 22 Ma. (author) [pt

Transpressional granite-emplacement model: Structural and magnetic study of the Pan-African Bandja granitic pluton (West Cameroon)

Science.gov (United States)

Sandjo, A. F. Yakeu; Njanko, T.; Njonfang, E.; Errami, E.; Rochette, P.; Fozing, E.

2016-02-01

The Pan-African NE-SW elongated Bandja granitic pluton, located at the western part of the Pan-African belt in Cameroon, is a K-feldspar megacryst granite. It is emplaced in banded gneiss and its NW border underwent mylonitization. The magmatic foliation shows NE-SW and NNE-SSW strike directions with moderate to strong dip respectively in its northern and central parts. This mostly, ferromagnetic granite displays magnetic fabrics carried by magnetite and characterized by (i) magnetic foliation with best poles at 295/34, 283/33 and 35/59 respectively in its northern, central and southern parts and (ii) a subhorizontal magnetic lineation with best line at 37/8, 191/9 and 267/22 respectively in the northern, central and southern parts. Magnetic lineation shows an `S' shape trend that allows to (1) consider the complete emplacement and deformation of the pluton during the Pan-African D 2 and D 3 events which occurred in the Pan-African belt in Cameroon and (2) reorganize Pan-African ages from Nguiessi Tchakam et al. (1997) compared with those of the other granitic plutons in the belt as: 686 ±17 Ma (Rb/Sr) for D 1 age of metamorphism recorded in gneiss; and the period between 604-557 Ma for D 2-D 3 emplacement and deformation age of the granitic pluton in a dextral ENE-WSW shear movement.

Oster pluton (Central Karelia) - the ancient massif of two-feldspar granites of Baltic Shield

International Nuclear Information System (INIS)

Kovalenko, A.V.; Rizvanova, N.G.

2000-01-01

Geochronological study of two-feldspar granites forming the Oster pluton in the Central Karelia was performed using the methods of U-Pb- and Sm-Nd-dating. U-Pb isotope data for zircons from granite of the Oster pluton correspond to the age of 2876±21 mln. years, whereas Sm-Nd isotope data obtained for three samples of the garnet correspond to the age varying from 3.0 to 3.5 bln. years. The ancient age of granites of the Oster pluton is explained by the presence of a sufficiently powerful crust in the region by that moment [ru

Optical dating using feldspar from Quaternary alluvial and colluvial sediments from SE Brazilian Plateau, Brazil

International Nuclear Information System (INIS)

Tatumi, Sonia H.; Peixoto, Maria Naise O.; Moura, Josilda R.S.; Mello, Claudio L.; Carmo, Isabela O.; Kowata, Emilia A.; Yee, Marcio; Brito, Silvio Luiz M.; Gozzi, Giuiliano; Kassab, Luciana R.P.

2003-01-01

Opticallly stimulated luminescence (OSL) dating has been applied to a wide variety of materials such as loess, sand dunes, colluvium, alluvium, volcanic products, etc., helping geologic geomorphologic studies. OSL dating results using feldspar crystals extracted from alluvial and colluvial deposits of SE Brazilian Plateau will be presented in this work. The methodology used is based on the regeneration method, with multiple aliquot protocol. A total of 23 sample ages were obtained spanning 6.5-97.2 kyr. Results of radioactive contents and comparison with radiocarbon ages will be discussed

Determination of potassium by means of the {sup 40}K measurement; Determinacion de potasio mediante la medicion del {sup 40}K

Energy Technology Data Exchange (ETDEWEB)

Escareno J, E.; Vega C, H. R., E-mail: edmundoej@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

2011-11-15

The concentration of total potassium through the gamma-rays measurement of 1461 KeV emitted during the disintegration of the {sup 40}K was determined. In the nature three isotopes of the K exist: {sup 39}K, {sup 41}K and {sup 40}K, this last is radioactive with a half life of 1.2 x 10{sup 9} years. The {sup 40}K isotope is in a relationship of 0.0117% with regard to the K, this characteristic is used with the purpose of estimating the total quantity of potassium. The potassium has a very important paper in the growth and the reproduction of animals and plants. Due to the secular equilibrium, the emission of {gamma}-rays is proportional to the concentration of K. In this work a group of calibration sources were prepared and a spectrometry system was characterized with NaI(Tl) to determine the concentration of total K. (Author)

determination of reaeration coefficient k2 for polluted stream as a ...

African Journals Online (AJOL)

include velocity of flow, average depth of flow, DO, self purification ratio (f) and reaeration constant (K2). ... Determination of Reaeration Reaeration Coefficient K2 for Polluted Stream. 175. Table 1: ... and theory on which it is based. The result ...

Determining activity of 40K with disturbing from 228Ra by γ spectrometry

International Nuclear Information System (INIS)

Su Qiong

1997-09-01

The measurement methods and some viewpoints for processing data about determining activities in a reference material are reported (The Laboratory of Industrial Hygiene Ministry have a hand in the determining). The measurement and correct problems of determining activity of 40 K with disturbing from 228 Ra by γ spectrometry, which were neglected in the past a lot of measurement, are especially described. It is pointed out that if the correct is neglected then the value of 40 K in the current reference material, in that activities of both 22 '8Ra and 40 K are matched, will be determined with system error of about 20%. (14 refs., 3 tabs.)

A method for evaluating basement exhumation histories from closure age distributions of detrital minerals

International Nuclear Information System (INIS)

Lovera, Oscar M.; Grove, Marty; Kimbrough, David L.; Abbott, Patrick L.

1999-01-01

We have developed a two-dimensional, thermokinetic model that predicts the closure age distributions of detrital minerals from pervasively intruded and differentially exhumed basement. Using this model, we outline a method to determine the denudation history of orogenic regions on the basis of closure age distributions in synorogenic to postorogenic forearc strata. At relatively high mean denudation rates of 0.5 km m.y.-1 sustained over millions of years, magmatic heating events have minimal influence upon the age distributions of detrital minerals such as K-feldspar that are moderately retentive of radiogenic Ar. At lower rates, however, the effects of batholith emplacement may be substantial. We have applied the approach to detrital K-feldspars from forearc strata derived from the deeply denuded Peninsular Ranges batholith (PRB). Agreement of the denudation history deduced from the detrital K-feldspar data with thermochronologic constraints from exposed PRB basement lead us to conclude that exhumation histories of magmatic arcs should be decipherable solely from closure age distributions of detrital minerals whose depositional age is known. (c) 1999 American Geophysical Union

New insights into the origin of ladder dikes: Implications for punctuated growth and crystal accumulation in the Cathedral Peak granodiorite

Science.gov (United States)

Wiebe, R. A.; Jellinek, A. M.; Hodge, K. F.

2017-04-01

Ladder dikes are steep tabular bodies, typically a meter or less thick, composed of moderately dipping, concave upward, alternating dark (i.e. schlieren) and light bands oriented roughly perpendicular to the ladder dike margins. These structures occur widely but sparsely in granitic rocks and are found prominently in the Cathedral Peak granodiorite (CPG) of the Tuolumne Intrusive suite. Previous studies have interpreted that ladder dikes form as a result of processes including the downward flow of crystal mush in cracks within strong crystal mush or by upward flow in steep tubes that migrate within a strong crystal mush. Our new observations indicate that ladder dikes formed by downward flow of crystal mush in troughs or valleys, in a manner potentially comparable to trough bands in mafic layered intrusions. Extensions of the schlieren outward and upward away from the ladder dike margins into the host granite demonstrate that the host granite was deposited as mounds on both sides at the same time as the ladder dikes. Ladder dikes, therefore, record lateral flows of crystal mush on a magma chamber floor. Vertical exposures suggest these flows are on the order of ten meters thick. Some steep exposures on granite domes indicate multiple ladder dikes (and flows) over a stratigraphic height of 80-100 m. Later (stratigraphically higher) flows commonly deform and erode the top of an earlier flow, and granitic material rich in K-feldspar megacrysts has locally engulfed large blocks of ladder dikes, demonstrating that the megacrysts were also transported in flows. Flows in the CPG are directed away from the center of the pluton toward the western and eastern margins and apparently spread along a strong crystal mush floor and into a rheologically complex CPG magma. Whereas established dynamical models for spreading (single phase) gravity currents with simple and complex rheologies explain the elongate geometry, spacing and orientation of the tabular bodies, the origin and

Sorption of environmentally relevant radionuclides (U(VI), Np(V)) and lanthanides (Nd(III)) on feldspar and mica

Energy Technology Data Exchange (ETDEWEB)

Richter, Constanze

2015-11-05

A safe storage of radioactive waste in repositories is an important task to protect humans and the environment from radio- and chemotoxicity. Long-term safety assessments predict the behavior of potential environmental contaminants like the actinides plutonium, uranium, or neptunium, in the near and far field of repositories. For such safety assessments, it is necessary to know the migration behavior of the contaminants in the environment, which is mainly dependent on the aquatic speciation, the solubility product of relevant solid phases, and the retardation due to sorption on surrounding minerals. Thus, an investigation of sorption processes of contaminants onto different minerals as well as the derivation of mineral specific surface complexation model (SCM) parameters is of great importance. Feldspar and mica are widely distributed in nature. They occur as components of granite, which is considered as a potential host rock for a repository in Germany, and in numerous other rocks, and thus also in the far field of nearly all repositories. However, their sorption behavior with actinides has only been scarcely investigated until now. In order to better characterize these systems and subsequently to integrate these minerals into the long-term safety assessments, this work focuses on the investigation of the sorption behavior of U(VI), Np(V), and Nd(III) as analogue for An(III) onto the minerals orthoclase and muscovite, representing feldspars and mica, respectively. All investigations were performed under conditions relevant to the far field of a repository. In addition to the extensive characterization of the minerals, batch sorption experiments, spectroscopic investigations, and surface complexation modeling were performed to elucidate the uptake and speciation of actinides on the mineral surfaces. In addition, the influence of microorganisms naturally occurring on the mineral surfaces and the effect of Ca{sup 2+} on U(VI) uptake on the minerals was studied. The

Sorption of environmentally relevant radionuclides (U(VI), Np(V)) and lanthanides (Nd(III)) on feldspar and mica

International Nuclear Information System (INIS)

Richter, Constanze

2015-01-01

A safe storage of radioactive waste in repositories is an important task to protect humans and the environment from radio- and chemotoxicity. Long-term safety assessments predict the behavior of potential environmental contaminants like the actinides plutonium, uranium, or neptunium, in the near and far field of repositories. For such safety assessments, it is necessary to know the migration behavior of the contaminants in the environment, which is mainly dependent on the aquatic speciation, the solubility product of relevant solid phases, and the retardation due to sorption on surrounding minerals. Thus, an investigation of sorption processes of contaminants onto different minerals as well as the derivation of mineral specific surface complexation model (SCM) parameters is of great importance. Feldspar and mica are widely distributed in nature. They occur as components of granite, which is considered as a potential host rock for a repository in Germany, and in numerous other rocks, and thus also in the far field of nearly all repositories. However, their sorption behavior with actinides has only been scarcely investigated until now. In order to better characterize these systems and subsequently to integrate these minerals into the long-term safety assessments, this work focuses on the investigation of the sorption behavior of U(VI), Np(V), and Nd(III) as analogue for An(III) onto the minerals orthoclase and muscovite, representing feldspars and mica, respectively. All investigations were performed under conditions relevant to the far field of a repository. In addition to the extensive characterization of the minerals, batch sorption experiments, spectroscopic investigations, and surface complexation modeling were performed to elucidate the uptake and speciation of actinides on the mineral surfaces. In addition, the influence of microorganisms naturally occurring on the mineral surfaces and the effect of Ca 2+ on U(VI) uptake on the minerals was studied. The

Preliminary assessment of clinoptilolite K/Ar results from Yucca Mountain, Nevada: A potential high-level radioactive waste repository site

International Nuclear Information System (INIS)

WoldeGabriel, G.; Bish, D.L.; Broxton, D.E.; Chipera, S.J.

1992-01-01

At Yucca Mountain, evidence for at least three distinct temporal groups of clinoptilolites can be delineated from the preliminary K/Ar dates (2--3 Ma; 4--5 Ma; 7--11 Ma). The older K/Ar dates that are similar to published illite/smectite ages (9--12 Ma) may be crystallization ages, whereas the younger dates probably represent continued diagenetic reactions of older clinoptilolites with percolating fluids. The K/Ar dates increase with depth, suggesting minimal argon loss in the deeper samples. Internal consistency of the clinoptilolite K/Ar results at different levels within the drill holes suggest that dating of K-rich zeolites may provide useful information for assessing the zeolitization at Yucca Mountain. Variations in the K/Ar dates are probably related to Ar loss during dissolution of older clinoptilolites and to contamination by finely crystalline feldspars

Metasomatized and hybrid rocks associated with a Palaeoarchaean layered ultramafic intrusion on the Johannesburg Dome, South Africa

Science.gov (United States)

Anhaeusser, Carl R.

2015-02-01

The Johannesburg Dome occurs as an inlier of Palaeoarchaean-Mesoarchaean granitic rocks, gneisses and greenstones in the central part of the Kaapvaal Craton, South Africa. In the west-central part of the dome a large greenstone remnant is surrounded and intruded by ca. 3114 Ma porphyritic granodiorites. Referred to locally as the Zandspruit greenstone remnant, it consists of a shallow-dipping ultramafic complex comprised of a number of alternating layers of harzburgite and pyroxenite. The ultramafic rocks are metamorphosed to greenschist grade and have largely been altered to serpentinite and amphibolite (tremolite-actinolite). In the granite-greenstone contact areas the porphyritic granodiorite has partially assimilated the greenstones producing a variety of hybrid rocks of dioritic composition. The hybrid rocks contain enclaves or xenoliths of greenstone and, in places, orbicular granite structures. Particularly noteworthy is an unusual zone of potash-metasomatized rock, occurring adjacent to the porphyritic granodiorite, consisting dominantly of biotite and lesser amounts of carbonate, quartz and sericite. Large potash-feldspar megacrysts and blotchy aggregated feldspar clusters give the rocks a unique texture. An interpretation placed on these rocks is that they represent metasomatized metapyroxenites of the layered ultramafic complex. Field relationships and geochemical data suggest that the rocks were influenced by hydrothermal fluids emanating from the intrusive porphyritic granodiorite. The adjacent greenstones were most likely transformed largely by the process of infiltration metasomatism, rather than simple diffusion, as CO2, H2O as well as dissolved components were added to the greenstones. Element mobility appears to have been complex as those generally regarded as being immobile, such as Ti, Y, Zr, Hf, Ta, Nb, Th, Sc, Ni, Cr, V, and Co, have undergone addition or depletion from the greenstones. Relative to all the rocks analyzed from the greenstones

Sorption of cesium and uranium to Feldspar

International Nuclear Information System (INIS)

Wijland, G.C.; Pennders, R.M.J.

1990-07-01

Within safety assessment studies, for nuclear waste disposal in deep geologic formations, calculation for the migration of radionuclides through the geosphere are often carried out with models taking sorption into account. In the past 8 years the insight grew that other physico-chemical processes, besides sorption, could affect migration behaviour. While the currently used transport models were being improved taking either linear or non-linear sorption into account, the coupling of geochemical and transport models came into scope. In spite of these developments models which are still based on the sorption theory are frequently applied in studying migration behaviour of radionuclides. This is caused by the necessity of making preliminary pronouncements, while coupled models are still in stage of development and thermodynamic data are very limited available. Therefore one has to obtain insight in the reliability of the models based on the sorption theory. within the sorption database there is a lack of knowledge about mineralogy, composition of the fluid and the experimental conditions underlying the data. Therefore the Expert Group on geochemical Modelling supported by the Finnish proposal in order to obtain insight in the possible deviation of the sorption coefficients that can be estimated from experiments performed with standard samples, fluid composition and experimental conditions. Nine laboratories from OECD membership countries took part in this intercalibration study. In the framework of the Dutch safety assessment studies the Dutch National Institute of Public health and Environmental protection (RIVM) has decided to participate in this exercise. In this report the results are presented of sorption experiments for cesium and natural Uranium to Feldspar. (H.W.). 4 refs.; 1 fig.; 7 tabs

The rapakivi granite plutons of Bodom and Obbnäs, southern Finland: petrography and geochemistry

Directory of Open Access Journals (Sweden)

Kosunen, P.

1999-12-01

Full Text Available The Obbnäs and Bodom granite plutons of southernmost Finland show the typical petrographic and geochemical features of the Proterozoic rapakivi granites in Finland and elsewhere: they cut sharply across the 1900 Ma Svecofennian metamorphic bedrock and have the geochemical characteristics of subalkaline A-type granites. The Bodom pluton is composed of porphyritic granites (hornblende-, hornblende-biotite-, and biotite-bearing varieties and an even-grained granite that probably represent two separate intrusive phases. This lithologic variation does not occur in the Obbnäs pluton, which is almost entirely composed of porphyritic hornblende-biotite granite that gradually becomes more mafic to the southwest. Three types of hybrid granitoids resulting from magma mingling and mixing occur on the southwestern tip of the Obbnäs peninsula. The Bodom granites are syenogranites, whereas the composition of the Obbnäs granite varies from syeno- to monzogranite. The main silicates of both the Bodom and Obbnäs granites are quartz, microcline, plagioclase (An1541, biotite (siderophyllite, and generally also amphibole (ferropargasite or hastingsite. Plagioclase-mantled alkali feldspar megacrysts are absent or rare. The accessory minerals are fluorite, allanite, zircon, apatite, and iron-titanium oxides; the Obbnäs granite also contains titanite. The Bodom and Obbnäs granites are metaluminous to weakly peraluminous, with average A/CNK of 1.00 and 1.05, respectively, have high Fe/Mg (average FeOtot/[FeOtot+MgO] is 0.94 for the Bodom and 0.87 for the Obbnäs granites, and high Ga/Al (3.78 to 5.22 in Bodom and 2.46 to 4.18 in Obbnäs. The REE contents are high with LREE-enriched chondrite-normalized patterns and moderate (Obbnäs to relatively strong (Bodom negative Eu-anomalies. The Obbnäs granite is enriched in CaO, TiO2, MgO, and FeO, and depleted in SiO2 and K2O compared to the Bodom granites. Also, there are differences in the Ba, Rb, and Sr contents of

Isolation, crystallization and crystal structure determination of bovine kidney Na(+),K(+)-ATPase.

Science.gov (United States)

Gregersen, Jonas Lindholt; Mattle, Daniel; Fedosova, Natalya U; Nissen, Poul; Reinhard, Linda

2016-04-01

Na(+),K(+)-ATPase is responsible for the transport of Na(+) and K(+) across the plasma membrane in animal cells, thereby sustaining vital electrochemical gradients that energize channels and secondary transporters. The crystal structure of Na(+),K(+)-ATPase has previously been elucidated using the enzyme from native sources such as porcine kidney and shark rectal gland. Here, the isolation, crystallization and first structure determination of bovine kidney Na(+),K(+)-ATPase in a high-affinity E2-BeF3(-)-ouabain complex with bound magnesium are described. Crystals belonging to the orthorhombic space group C2221 with one molecule in the asymmetric unit exhibited anisotropic diffraction to a resolution of 3.7 Å with full completeness to a resolution of 4.2 Å. The structure was determined by molecular replacement, revealing unbiased electron-density features for bound BeF3(-), ouabain and Mg(2+) ions.

The Application of Determining Students’ Graduation Status of STMIK Palangkaraya Using K-Nearest Neighbors Method

Science.gov (United States)

Rusdiana, Lili; Marfuah

2017-12-01

K-Nearest Neighbors method is one of methods used for classification which calculate a value to find out the closest in distance. It is used to group a set of data such as students’ graduation status that are got from the amount of course credits taken by them, the grade point average (AVG), and the mini-thesis grade. The study is conducted to know the results of using K-Nearest Neighbors method on the application of determining students’ graduation status, so it can be analyzed from the method used, the data, and the application constructed. The aim of this study is to find out the application results by using K-Nearest Neighbors concept to determine students’ graduation status using the data of STMIK Palangkaraya students. The development of the software used Extreme Programming, since it was appropriate and precise for this study which was to quickly finish the project. The application was created using Microsoft Office Excel 2007 for the training data and Matlab 7 to implement the application. The result of K-Nearest Neighbors method on the application of determining students’ graduation status was 92.5%. It could determine the predicate graduation of 94 data used from the initial data before the processing as many as 136 data which the maximal training data was 50data. The K-Nearest Neighbors method is one of methods used to group a set of data based on the closest value, so that using K-Nearest Neighbors method agreed with this study. The results of K-Nearest Neighbors method on the application of determining students’ graduation status was 92.5% could determine the predicate graduation which is the maximal training data. The K-Nearest Neighbors method is one of methods used to group a set of data based on the closest value, so that using K-Nearest Neighbors method agreed with this study.

Combining infrared- and green-laser stimulation sources in single-grain luminescence measurements of feldspar and quartz

DEFF Research Database (Denmark)

Duller, G.A.T.; Bøtter-Jensen, L.; Murray, A.S.

2003-01-01

A system designed for measurement of the optically stimulated luminescence (OSL) from individual sand-sized mineral grains has been constructed. Previously, this system was equipped only with a green laser emitting at 532 run, but now an infrared (IR) laser at 830 run has been added. It is now...... possible to interchangeably use the two laser sources for optical stimulation. This is especially valuable for the measurement of feldspars. The power density using the IR laser at the grain is similar to500 W cm(-2), and stimulation for 1 s reduces the OSL signal to near background level. Initial results...

Determination of Impurities in Aluminum Alloy by INAA Single Comparator Method (K0-Standardization Method)

International Nuclear Information System (INIS)

Sarheel, A.; Khamis, I.; Somel, N.

2007-01-01

Multielement determination by the k0 based INAA using k0-IAEA program has been performed at Syrian Atomic Energy Commission using alloys. Concentrations of Cu, Zn, Fe, Ni, Sn and Ti in addition to aluminum element were determined in an aluminum alloy and Ni, Cr, Mo were determined in dental alloys using INAA k0-standardization method. Al-0.1%Au, Ni and Zn certified reference materials were analyzed to assess the suitability and accuracy of the method. Elements were determined in reference materials and samples after short and long irradiations, according to element half-lives.

Influence of feldspar containing lithium in the sintering of triaxial ceramics

International Nuclear Information System (INIS)

Oliveira, Camila Felippe de; Strecker, Kurt

2011-01-01

In this work, the properties of a ceramic material based on a triaxial mass composed of clay, quartz and 15 to 30% feldspar, albite or spodumene, has been investigated. Specimen were prepared by uniaxial pressing under 28.5MPa and sintering at temperatures of 1000, 1100 and 1200 deg C, for 1h. The samples were characterized by their linear shrinkage, apparent porosity, apparent density and flexural strength, as well as analysis of the microstructure. The best results were obtained for samples prepared with 30% spodumene and sintered at 1200 deg C, with a shrinkage of 6.4%, density of 2.01g/cm 3 , porosity of 14.3% and flexural strength of 13.4MPa, while samples prepared with albite exhibited shrinkage of 5.8%, density of 1.9g/cm 3 , porosity of 18.9% and strength of 9.8MPa. Therefore, by the substitution of albite by spodumene in the ceramic triaxial mass, lower sintering temperatures may be employed, thus reducing production costs by the lesser energy consumption. (author)(

An exsolution silica-pump model for the origin of myrmekite

Science.gov (United States)

Castle, R.O.; Lindsley, D.H.

1993-01-01

Myrmekite, as defined here, is the microscopic intergrowth between vermicular quartz and modestly anorthitic plagioclase (calcic albite-oligoclase), intimately associated with potassium feldspar in plutonic rocks of granitic composition. Hypotheses previously invoked in explanation of myrmekite include: (1) direct crystallization; (2) replacement; (3) exsolution. The occurrence of myrmekite in paragneisses and its absence in rocks devold of discrete grains of potassium feldspar challenge those hypotheses based on direct crystallization or replacement. However, several lines of evidence indicate that myrmekite may in fact originate in response to kinetic effects associated with the exsolution of calcic alkali feldspar into discrete potassium feldspar and plagioclase phases. Exsolution of potassium feldspar system projected from [AlSi2O8] involves the exchange CaAlK-1Si-1, in which the AlSi-1 tetrahedral couple is resistant to intracrystalline diffusion. By contrast, diffusion of octahedral K proceeds relatively easily where it remains uncoupled to the tetrahedral exchange. We suggest here that where the ternary feldspar system is open to excess silica, the exchange reaction that produces potassium feldspar in the ternary plane is aided by the net-transfer reaction K+Si=Orthoclase, leaving behind indigenous Si that reports as modal quartz in the evolving plagioclase as the CaAl component is concomitantly incorporated in this same phase. Thus silica is "pumped" into the reaction volume from a "silica reservoir", a process that enhances redistribution of both Si and Al through the exsolving ternary feldspar. ?? 1993 Springer-Verlag.

Further investigations on 'non-fading' in K-Feldspar

DEFF Research Database (Denmark)

Jain, Mayank; Buylaert, Jan-Pieter; Thomsen, Kristina Jørkov

2015-01-01

, suggesting that the higher the stimulation temperature in post IR-IRSL methods, the greater the ability to access distant electron hole pairs. We further find that the delayed off-time signal in time-resolved IRSL has immense potential for sampling non-fading signal and should be explored further...

Determination of the enthalpy of fusion of K{sub 3}TaF{sub 8} and K{sub 3}TaOF{sub 6}

Energy Technology Data Exchange (ETDEWEB)

Kosa, L. [Institute of Inorganic Chemistry, Slovak Academy of Sciences, SK-845 36 Bratislava (Slovakia)]. E-mail: uachkosa@savba.sk; Mackova, I. [Institute of Inorganic Chemistry, Slovak Academy of Sciences, SK-845 36 Bratislava (Slovakia)

2006-08-15

The areas of the fusion and crystallization peaks of K{sub 3}TaF{sub 8} and K{sub 3}TaOF{sub 6} have been measured using the DSC mode of the high-temperature calorimeter (SETARAM 1800 K). On the basis of these quantities and the temperature dependence of the used calorimetric method sensitivity, the values of the enthalpy of fusion of K{sub 3}TaF{sub 8} at temperature of fusion 1039 K: {delta}{sub fus} H {sub m}(K{sub 3}TaF{sub 8}; 1039 K) = (52 {+-} 2) kJ mol{sup -1} and of K{sub 3}TaOF{sub 6} at temperature of fusion 1055 K: {delta}{sub fus} H {sub m}(K{sub 3}TaOF{sub 6}; 1055 K) = (62 {+-} 3) kJ mol{sup -1} have been determined.

In situ dating on Mars: A new approach to the K-Ar method utilizing cosmogenic argon

Science.gov (United States)

Cassata, William S.

2014-01-01

Cosmogenic argon isotopes are produced in feldspars via nuclear reactions between cosmic rays and Ca and K atoms within the lattice. These cosmogenic isotopes can be used as proxies for K and Ca, much like nuclear reactor-derived 39Ar and 37Ar are used as proxies for K and Ca, respectively, in 40Ar/39Ar geochronology. If Ca and K are uniformly distributed, then the ratio of radiogenic 40Ar (40Ar*) to cosmogenic 38Ar or 36Ar (38Arcos or 36Arcos) is proportional to the difference between the radioisotopic and exposure ages, as well as the K/Ca ratio of the degassing phase. Thus cosmogenic, radiogenic, and trapped Ar isotopes, all of which can be measured remotely and are stable over geologic time, are sufficient to generate an isochron-like diagram from which the isotopic composition of the trapped component may be inferred. Such data also provide a means to assess the extent to which the system has remained closed with respect to 40Ar*, thereby mitigating otherwise unquantifiable uncertainties that complicate the conventional K-Ar dating method.

Gamma Spectrometric Determination of U, Th, K and Some Geochemical Applications

International Nuclear Information System (INIS)

Dodona, A.; Tashko, A.

2001-01-01

The application of 'in situ' gamma-spectrometric method (''infinite'' environment), made possible the simultanious determination of U, Th and K. 4 channel gamma-spectrometric analyser with NaI(TI) scintilation counter crystal detector (103 cm 3 φ=50x50mm) was used to determin U, Th(more than 1-2 ppm) and K (more than 1%) in laboratory conditions. The detector was inserted into a lead camera and calibrated for measurement geometry with vessel of ''Marineli'' type of a 17o cm 3 volume. The study of main factors, which influence in the gamma spectrometric measurements, (the technical, physical, geometrical and time parameters) has been carried out. International standards of U, Th, K and internal monitoring standard samples are used for the calibration. External analytical control has been realized by other radiometric and chemical methods. The detection limits ( 1 ppm Th, 2ppm U and 1% K) and the relative errors (17-20% for 1-10 ppm U, Th and 10-15% for more than 10 ppm U, Th and more than 1% K) guarantee a quantitative analysis that may be used successfully in the geochemical studies. Some geochemical applications, based on the content of Th, U and Th/U ratio in rocks samples that we have we have analyzed with this method, are shown in this paper. U, Th and their ratio are used as trace elements to indicate the differences between the acidic magmatic rocks of Albania (Th/U ratio=2-6 and>10). The bimodal character of Th/U scattering in ignimbrides and monzonites (Korabi zone) shows that in addition to the ''normal'' rocks, there are also some ones enriched with Th, So, the differential analysis of Th, U, and K may be used as geochemical exploration criteria for the radioactive and non-radioactive mineralization, such as REE (Rare Earth Elements), phospghorites, bauxites, placers etc. (authors)

Standardization of 40 K by liquid scintillation counting. Determination of the half-life

International Nuclear Information System (INIS)

Grau Carles, A.; Grau Malonda, A.

1997-01-01

The relative abundance of the natural radioisotope ''40 K in environmental samples frequently generates interferences in low activity measurements. In the present study we propose the determination of ''40 K by the CIEMAT/NIST method. On this context, the verification of ''40 K half-life is required. We present a half-life value obtained by liquid scintillation counting in excellent agreement with those reported in the literature. (Author)

Determination of U, Th and K for optically stimulated luminescence dating by NAA

International Nuclear Information System (INIS)

Qin Yali; Chen Zhe; Wu Weiming

2010-01-01

Optically stimulated luminescence dating techniques have been widely used in northern Loess ancient soil series and recorded climate environment change, ancient earthquake, the ancients site and archaeology research. The determination of U, Th and K using neutron activation analysis (NAA) has been optimized for the samples related to OSL dating research. The procedure for determination of U, Th, K in loess have been fixed by using Miniature neutron source reactor. This procedure of NAA will provide a reliable data base for optically stimulated luminescence dating research. (authors)

The quick and ultrasensitive determination of K in NaI using inductively coupled plasma mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Arnquist, Isaac J., E-mail: isaac.arnquist@pnnl.gov; Hoppe, Eric W.

2017-04-11

A highly sensitive, novel and quick assay method utilizing inductively coupled plasma mass spectrometry was developed for the determination of K in NaI powders and NaI(Tl) scintillator crystals for use in ultralow background applications. The determination of K (viz.{sup 40}K), as well as Th and U and their daughters, is important in ultralow background detector materials to ensure incorporation of materials of sufficiently high radiopurity. Through the use of improved instrumentation, cool plasma operating conditions, and meticulously clean sample preparations, detection limits of 11 fg {sup nat}K g{sup −1} (or 341 pBq {sup 40}K kg{sup −1}) was attained for K in pure water. Detection limits in the sample matrix (i.e., NaI) were 0.529 ng {sup nat}K g NaI{sup −1} (or 16.4 μBq {sup 40}K kg NaI{sup −1}). A number of different precursor NaI powder samples and NaI(Tl) scintillator crystals were assayed for their K content. Determinations ranged from 0.757 to 31.4 ng {sup nat}K g NaI{sup −1}. This method allows for the screening of materials to unprecedented levels in a fraction of the time compared to gamma ray counting techniques, providing a useful method for a more effective screening tool of K in ultralow background detector materials.

Determination of the K*(1800) spin parity

Energy Technology Data Exchange (ETDEWEB)

Brandenburg, G W; Carnegie, R K; Cashmore, R J; Davier, M; Dunwoodie, W M; Lasinski, T A; Leith, D W.G.S.; Matthews, J A.J.; Walden, P; Williams, S H [Stanford Linear Accelerator Center, Calif. (USA)

1976-02-16

A spherical harmonic moment analysis of the reactions K/sup -/p..-->..K/sup -/..pi../sup +/n and K/sup +/p..-->..K/sup +/..pi../sup -/..delta../sup + +/ at 13 GeV/c demonstrates the existence of a broad K* state with mass in the vicinity of 1800 MeV and spin parity 3/sup -/.

Oxygen mobility in alkali feldspars; Etude de la mobilite de l'oxygene dans les feldspaths alcalins

Energy Technology Data Exchange (ETDEWEB)

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

1968-03-15

The oxygen mobility is shown from oxygen atoms exchange between potassic and sodic feldspars and 18 oxygen enriched water. Exchanges are carried out in autoclaves between 400 and 800 deg. C under a water pressure between 300 and 800 bars. The oxygen is extracted from silicate by a ClF{sub 3} attack. Two distinct mechanisms may be found. The first one is auto-diffusion; for adularia we have: D = 9.10{sup -7} exp(-32000/RT) (cm{sup 2}.s{sup -1}), for albite: D 4.5.10{sup -5} exp(-37000/RT) (cm{sup 2}.s{sup -1}). The second one, more rapid, is associated with alkali atoms exchanges. These results are applied to the order-disorder problem in feldspars and to the oxygen geochemistry. (author) [French] La mobilite de l'oxygene est mise en evidence a partir d'echanges d'atomes d'oxygene entre des feldspaths potassiques et sodiques en presence d'une eau enrichie en oxygene 18. Les echanges sont effectues en autoclave entre 400 et 800 deg. C sous des pressions de vapeur d'eau comprises entre 300 et 800 bars. L'oxygene est extrait du silicate par attaque au ClF{sub 3}. Deux mecanismes, bien distincts, peuvent se rencontrer. Le premier correspond a l'autodiffusion de l'oxygene; dans le domaine etudie on trouve pour l'adulaire: D = 9,10{sup -7} exp(-32000/RT) (cm{sup 2}.s{sup -1}), et pour l'albite: D 4,5.10{sup -5} exp(-37000/RT) (cm{sup 2}.s{sup -1}). Le second, beaucoup plus rapide, est associe a l'echange des atomes alcalins avec la solution. Ces resultats sont appliques au probleme du passage ordre-desordre dans les feldspaths et a la geochimie de l'oxygene. (auteur)

Origin of felsic granulite microstructure by heterogeneous decomposition of alkali feldspar and extreme weakening of orogenic lower crust during the Variscan orogeny

Czech Academy of Sciences Publication Activity Database

Franěk, J.; Schulmann, K.; Lexa, O.; Ulrich, Stanislav; Štípská, P.; Haloda, J.; Týcová, P.

2011-01-01

Roč. 29, č. 1 (2011), s. 103-130 ISSN 0263-4929 R&D Projects: GA ČR GA205/09/0539 Grant - others:GA ČR(CZ) GA205/05/2187 Institutional research plan: CEZ:AV0Z30120515 Keywords : felsic granulites * Moldanubian domain * quantitative microstructural analysis * quartz and feldspar rheology * Variscan belt Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.990, year: 2011

Chemical Zoning of Feldspars in Lunar Granitoids: Implications for the Origins of Lunar Silicic Magmas

Science.gov (United States)

Mills, R. D; Simon, J. I.; Alexander, C.M. O'D.; Wang, J.; Christoffersen, R.; Rahman, Z..

2014-01-01

Fine-scale chemical and textural measurements of alkali and plagioclase feldspars in the Apollo granitoids (ex. Fig. 1) can be used to address their petrologic origin(s). Recent findings suggest that these granitoids may hold clues of global importance, rather than of only local significance for small-scale fractionation. Observations of morphological features that resemble silicic domes on the unsampled portion of the Moon suggest that local, sizable net-works of high-silica melt (>65 wt % SiO2) were present during crust-formation. Remote sensing data from these regions suggest high concentrations of Si and heat-producing elements (K, U, and Th). To help under-stand the role of high-silica melts in the chemical differentiation of the Moon, three questions must be answered: (1) when were these magmas generated?, (2) what was the source material?, and (3) were these magmas produced from internal differentiation. or impact melting and crystallization? Here we focus on #3. It is difficult to produce high-silica melts solely by fractional crystallization. Partial melting of preexisting crust may therefore also have been important and pos-sibly the primary mechanism that produced the silicic magmas on the Moon. Experimental studies demonstrate that partial melting of gabbroic rock under mildly hydrated conditions can produce high-silica compositions and it has been suggested by that partial melting by basaltic underplating is the mechanism by which high-silica melts were produced on the Moon. TEM and SIMS analyses, coordinated with isotopic dating and tracer studies, can help test whether the minerals in the Apollo granitoids formed in a plutonic setting or were the result of impact-induced partial melting. We analyzed granitoid clasts from 3 Apollo samples: polymict breccia 12013,141, crystalline-matrix breccia 14303,353, and breccia 15405,78

Final report on AFRIMETS.QM-K27: Determination of ethanol in aqueous matrix

Science.gov (United States)

Archer, Marcellé; Fernandes-Whaley, Maria; Visser, Ria; de Vos, Jayne; Prins, Sara; Rosso, Adriana; Ruiz de Arechavaleta, Mariana; Tahoun, Ibrahim; Kakoulides, Elias; Luvonga, Caleb; Muriira, Geoffrey; Naujalis, Evaldas; Zakaria, Osman Bin; Buzoianu, Mirella; Bebic, Jelena; Achour Mounir, Ben; Thanh, Ngo Huy

2013-01-01

From within AFRIMETS, the Regional Metrology Organization (RMO) for Africa, the RMO Key Comparison AFRIMETS.QM-K27 was coordinated by the National Metrology Institute of South Africa (NMISA) in 2011. Ten Metrology Institutes participated, comprising three AFRIMETS, two APMP, four EURAMET and one SIM participant. Participants were required to determine the forensic level concentration of two aqueous ethanol solutions that were gravimetrically prepared by the NMISA. Concentrations were expected to lie in the range of 0.1 mg/g to 5.0 mg/g. The accurate determination of ethanol content in aqueous medium is critical for regulatory forensic and trade purposes. The CCQM Organic Analysis Working Group has carried out several key comparisons (CCQM-K27 series) on the determination of ethanol in wine and aqueous matrices. Developing NMIs now had the opportunity to link to the earlier CCQM-K27 studies through the AFRIMETS.QM-K27 study. Gas chromatography coupled to flame ionisation or mass spectrometric detection was applied by eight of the participants, while three participants (including NMISA) applied titrimetry for the ethanol assay. The assigned reference value of the aqueous ethanol solutions was used to link AFRIMETS.QM-K27 to the CCQM-K27 key comparison reference value. The assigned reference values for AFRIMETS.QM-K27 Level 1 and Level 2 were (0.3249 ± 0.0021) mg/g (k = 2) and (4.6649 ± 0.0152) mg/g (k = 2), respectively. The reference values were determined using the purity-corrected gravimetric preparation values, while the standard uncertainty incorporated the gravimetric preparation and titrimetric homogeneity uncertainties. From previous CCQM-K27 studies, the expected spread (%CV) of higher order measurements of ethanol in aqueous medium is about 0.85% relative. In this study the CV for Level 1 is about 12% (10% with two outliers removed) and for Level 2 about 4%. Three of the ten laboratories submitted results within 1.5% of the gravimetric reference value for

Melanin determination by high performance liquid chromatography (HPLC) for K. marxianus

Science.gov (United States)

Ultraviolet light (UV) mutated K. marxianus was found to turn dark brown during a growth assay. This brown color was hypothesized to be melanin overproduction influenced by the UV exposure. Cell cultures were oxidized and HPLC analyzed to determine melanin concentrations. The resulting melanin con...

Oxygen mobility in alkali feldspars; Etude de la mobilite de l'oxygene dans les feldspaths alcalins

Energy Technology Data Exchange (ETDEWEB)

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

1968-03-15

The oxygen mobility is shown from oxygen atoms exchange between potassic and sodic feldspars and 18 oxygen enriched water. Exchanges are carried out in autoclaves between 400 and 800 deg. C under a water pressure between 300 and 800 bars. The oxygen is extracted from silicate by a ClF{sub 3} attack. Two distinct mechanisms may be found. The first one is auto-diffusion; for adularia we have: D = 9.10{sup -7} exp(-32000/RT) (cm{sup 2}.s{sup -1}), for albite: D 4.5.10{sup -5} exp(-37000/RT) (cm{sup 2}.s{sup -1}). The second one, more rapid, is associated with alkali atoms exchanges. These results are applied to the order-disorder problem in feldspars and to the oxygen geochemistry. (author) [French] La mobilite de l'oxygene est mise en evidence a partir d'echanges d'atomes d'oxygene entre des feldspaths potassiques et sodiques en presence d'une eau enrichie en oxygene 18. Les echanges sont effectues en autoclave entre 400 et 800 deg. C sous des pressions de vapeur d'eau comprises entre 300 et 800 bars. L'oxygene est extrait du silicate par attaque au ClF{sub 3}. Deux mecanismes, bien distincts, peuvent se rencontrer. Le premier correspond a l'autodiffusion de l'oxygene; dans le domaine etudie on trouve pour l'adulaire: D = 9,10{sup -7} exp(-32000/RT) (cm{sup 2}.s{sup -1}), et pour l'albite: D 4,5.10{sup -5} exp(-37000/RT) (cm{sup 2}.s{sup -1}). Le second, beaucoup plus rapide, est associe a l'echange des atomes alcalins avec la solution. Ces resultats sont appliques au probleme du passage ordre-desordre dans les feldspaths et a la geochimie de l'oxygene. (auteur)

Flame photometric determination of Na, K and Li in uranium compounds

International Nuclear Information System (INIS)

Sabato, S.F.; Lordello, A.R.

1985-01-01

A flame photometric method for the determination of Na, K and Li in uranium compounds is described. The uranium is separated by solvent extraction from hydrochloric acid medium with tri-butyl phosphate. Amounts of uranium in order of 20 μg/ml don't cause any interference in the photometric results. The element Na presents a residual concentration due to the contamination of the reagents. The relative standard deviation is about 10% for the three elements. The relative error varies with the concentration of the element and it is between 1 and 24% for Na, between O and 12% for K and between O and 33% for Li. (Author) [pt

Partial replacement of the feldspar waste of flat glass ceramics for masses in white

International Nuclear Information System (INIS)

Porto, V.S.; Araujo, A.M.B.; Morais, C.R.S.; Cavalcanti, M.S.L.

2012-01-01

In all the industrial production process requires the consumption of raw materials exaggerated the traditional scarcity of incurring the same. To reverse this situation, one of the possible actions is the search for alternative technologies that aim to replace these materials by waste that exhibit similar characteristics. This study aims to verify the possibility of partially replacing feldspar by waste flat glass ceramic mass for white, since this type of waste, when subjected to high temperatures can act as a flux. For this research, initially the raw materials were characterized using the techniques of energy dispersive spectroscopy X-ray (EDX) and X-ray diffraction. Then, test pieces were prepared to be burned at temperatures between 1000 and 1250 ° C, which were submitted to tests of porosity to absorb water. The results are within the standards required by the standards established for ceramic products, which confirms the feasibility of such waste to act as a flux in ceramic white masses. (author)

Updated studies of determining gamma at LHCb with the decays $B^{+-} \\to D(K\\pi,KK,\\pi\\pi)K^{+-}$

CERN Document Server

Patel, M

2009-01-01

The selection efficiencies and backgrounds for the decays B+- -> DK+-, where the D denotes a D0bar or D0 which decays into the two-body final states Kpi, KK, pipi, are determined from simulation studies. These are used to estimate the precision with which LHCb will be able to measure the CKM angle gamma. With a data set corresponding to an intergrated luminosity of 2fb-1, a precision of 9.9-11.3 degrees is expected, depending on the strong phase difference between D0 -> K+pi- and D0->K-pi+ decays.

The assesment on safety distance determination of hydrogen production plant with RGTT200K reactor

International Nuclear Information System (INIS)

Siti Alimah; Sriyono

2013-01-01

The one of the hydrogen production process method coupled to RGTT200K is the utilization of steam reforming with (methane) natural gas as the feedstock. The integration between RGTT200K and hydrogen plant must consider many safety aspects and one of it is separation distance between these two systems. The purpose of this assessment is to study the sources of fires/explosion and to determine the safety distance between the steam reforming hydrogen production plant and RGTT200K reactor. The used methodology was literature assessment and safety distance calculation with equation R = k.W 1/3 . In this studi, safety distance determination in integration between RGTT200K and hydrogen plant was using equation based on reference of the USNRC Regulatory Guide 1.91 and mass on the equation was mass equivalent of TNT (kg). The results of the study show the hydrogen plant produces 160.000 m 3 /day, if requires storage tanks of 400.000 m 3 (based USNRC equal to 1.859 million tons of TNT equivalent) with factor k is 8, based on the equation R = k.W 1/3 , so the requirement for safety distance is 1 km. This distance may be shortened by adding a fire proof wall barrier and requires further assessment. (author)

K-Means Algorithm Performance Analysis With Determining The Value Of Starting Centroid With Random And KD-Tree Method

Science.gov (United States)

Sirait, Kamson; Tulus; Budhiarti Nababan, Erna

2017-12-01

Clustering methods that have high accuracy and time efficiency are necessary for the filtering process. One method that has been known and applied in clustering is K-Means Clustering. In its application, the determination of the begining value of the cluster center greatly affects the results of the K-Means algorithm. This research discusses the results of K-Means Clustering with starting centroid determination with a random and KD-Tree method. The initial determination of random centroid on the data set of 1000 student academic data to classify the potentially dropout has a sse value of 952972 for the quality variable and 232.48 for the GPA, whereas the initial centroid determination by KD-Tree has a sse value of 504302 for the quality variable and 214,37 for the GPA variable. The smaller sse values indicate that the result of K-Means Clustering with initial KD-Tree centroid selection have better accuracy than K-Means Clustering method with random initial centorid selection.

Performance Analysis of Combined Methods of Genetic Algorithm and K-Means Clustering in Determining the Value of Centroid

Science.gov (United States)

Adya Zizwan, Putra; Zarlis, Muhammad; Budhiarti Nababan, Erna

2017-12-01

The determination of Centroid on K-Means Algorithm directly affects the quality of the clustering results. Determination of centroid by using random numbers has many weaknesses. The GenClust algorithm that combines the use of Genetic Algorithms and K-Means uses a genetic algorithm to determine the centroid of each cluster. The use of the GenClust algorithm uses 50% chromosomes obtained through deterministic calculations and 50% is obtained from the generation of random numbers. This study will modify the use of the GenClust algorithm in which the chromosomes used are 100% obtained through deterministic calculations. The results of this study resulted in performance comparisons expressed in Mean Square Error influenced by centroid determination on K-Means method by using GenClust method, modified GenClust method and also classic K-Means.

Determination of the radiative decay width of the positive K*+(890) meson

International Nuclear Information System (INIS)

Chandlee, C.D.

1983-01-01

A systematic study of the coherent excitation of high energy pions and kaons by nuclear targets has been completed at Fermilab (Experiment 272) with the intent of extracting the radiative decay widths of the various vector and tensor mesons. This work was initiated to furnish experimental results for comparison with theoretical predictions based on unitary symmetry schemes, quark models, and vector dominance models with the hope of shedding light on the structure of the quark-antiquark system. The work presented here deals with data collected during the second running period of E272 on the excitation of incident 200 GeV/c K + by copper and lead targets for the purpose of precisely determining the radiative width from the transition K* + (890) → K + γ. The experiment was performed in the MIE secondary beam line of the Meson Lab utilizing an enhanced, Cherenkov tagged, positive kaon beam, a forward charged particle spectrometer consisting of drift and proportional wire chambers, and a liquid argon colorimeter for photon detection. A Primakoff type analysis of excitation in the nuclear Coulomb field including a strong contribution to the coherent production process from isoscalar exchange was applied to data for both the K + π 0 and K/sub S/ 0 π + decay modes of the K* +

(F)UV Spectroscopy of K648: Abundance Determination of Trace Elements

Science.gov (United States)

Mohamad-Yob, S. J.; Ziegler, M.; Rauch, T.; Werner, K.

2010-11-01

We present preliminary results of an ongoing spectral analysis of K 648, the central star of the planetary nebula Ps 1, based on high resolution FUV spectra. K 648, in M 15 is one of only four known PNe in globular clusters. The formation of this post-AGB object in a globular cluster is still unclear. Our aim is to determine Teff, log g, and the abundances of trace elements, in order to improve our understanding of post-AGB evolution of extremely metal-poor stars, especially PN formation in globular clusters. We analyzed FUSE, HST/STIS, and HST/FOS observations. A grid of stellar model atmospheres was calculated using the Tübingen NLTE Model Atmosphere Package (TMAP).

Age of a prehistoric "Rodedian" cult site constrained by sediment and rock surface luminescence dating techniques

DEFF Research Database (Denmark)

Sohbati, Reza; Murray, Andrew; Porat, N.

2015-01-01

The construction age of a pavement in a “Rodedian” prehistoric cult site in Negev desert, Israel, is established by determining the burial age of (i) a cobble used in the pavement, and (ii) the underlying sediment. The quartz OSL age and the K-feldspar corrected IR50 age from the sediment...

Semi-empirical spectrophotometric (SESp) method for the indirect determination of the ratio of cationic micellar binding constants of counterions X⁻ and Br⁻(K(X)/K(Br)).

Science.gov (United States)

Khan, Mohammad Niyaz; Yusof, Nor Saadah Mohd; Razak, Norazizah Abdul

2013-01-01

The semi-empirical spectrophotometric (SESp) method, for the indirect determination of ion exchange constants (K(X)(Br)) of ion exchange processes occurring between counterions (X⁻ and Br⁻) at the cationic micellar surface, is described in this article. The method uses an anionic spectrophotometric probe molecule, N-(2-methoxyphenyl)phthalamate ion (1⁻), which measures the effects of varying concentrations of inert inorganic or organic salt (Na(v)X, v = 1, 2) on absorbance, (A(ob)) at 310 nm, of samples containing constant concentrations of 1⁻, NaOH and cationic micelles. The observed data fit satisfactorily to an empirical equation which gives the values of two empirical constants. These empirical constants lead to the determination of K(X)(Br) (= K(X)/K(Br) with K(X) and K(Br) representing cationic micellar binding constants of counterions X and Br⁻). This method gives values of K(X)(Br) for both moderately hydrophobic and hydrophilic X⁻. The values of K(X)(Br), obtained by using this method, are comparable with the corresponding values of K(X)(Br), obtained by the use of semi-empirical kinetic (SEK) method, for different moderately hydrophobic X. The values of K(X)(Br) for X = Cl⁻ and 2,6-Cl₂C6H₃CO₂⁻, obtained by the use of SESp and SEK methods, are similar to those obtained by the use of other different conventional methods.

Petrología y geoquímica del granito Los Cuartos, Tafí del Valle, Tucumán, noroeste de Argentina: integración al esquema magmático regional

Directory of Open Access Journals (Sweden)

López, J. P.

2010-12-01

Full Text Available Los Cuartos Granite crops out on the western flank of the Cumbres Calchaquíes, east of Tafí del Valle, Tucumán Province, Argentina. It has a granitic to granodioritic composition, of two micas, being biotite dominant. The granite is medium grained and inequigranular, with rare K-feldspar megacrysts. It contains host-rock xenoliths with different degrees of assimilation. The granite intrusion produced con tact metamorphism in the surrounding basement, with development of andalucite porphyroblasts and poikiloblastic biotite. The granite is calk-alkaline and peraluminous, and is K- and P-rich and Ca- and Na poor compared to other granitoids of the region. The pluton shows late-tectonic features with regard to the regional deformation. The granite possibly intruded during the Ordovician (Famatinian Cycle and its emplacement was structurally controlled by the Tafí Megafracture. Los Cuartos Granite and other intrusive bodies of the region share similar petrographical, geochemical, structural and geochronological characteristics.

El Granito Los Cuartos aflora sobre la ladera occidental de Cumbres Calchaquíes, al E de la localidad de Tafí del Valle, provincia de Tucumán, Argentina. Es de composición granítica a granodiorítica, con desarrollo de dos micas, predominando la biotita. Es de grano medio e inequigranular, con megacristales de feldespato potásico raros o ausentes. Contiene xenolitos de la roca de caja con diferentes grados de digestión. Este cuerpo desarrolla fenómenos de metamorfismo de contacto en el basamento al que intruye, con desarrollo de porfiroblastos de andalucita y biotita poiquiloblástica. El granitoide presenta características calcoalcalina, peraluminosos, rico en K y P y con contenidos comparativamente más bajos en Ca y Na que los granitoides del área; poseen rasgos tardío-tectónicos con respecto a la deformación y su emplazamiento se habría producido durante el Ordovícico (Ciclo Famatiniano.

Provenance of sands from the confluence of the Amazon and Madeira rivers based on detrital heavy minerals and luminescence of quartz and feldspar

Science.gov (United States)

do Nascimento, Daniel R.; Sawakuchi, André O.; Guedes, Carlos C. F.; Giannini, Paulo C. F.; Grohmann, Carlos H.; Ferreira, Manuela P.

2015-03-01

Source-to-sink systems are poorly known in tropical rivers. For the Amazonian rivers, the majority of the provenance studies remain focused on the suspended load, implying a poor understanding of the processes governing production and distribution of sands. In this study, we perform heavy mineral and optically stimulated luminescence (OSL) analysis to cover the entire spectrum (heavy and light minerals fraction) of 29 sand samples of the Lower Madeira river region (Amazon and Madeira rivers), of which the main goal was to find provenance indicators specific to these rivers. Despite the tropical humid climate, the sands of the Amazon and Lower Madeira rivers are rich in unstable heavy minerals as augite, hypersthene, green hornblende and andalusite. The Madeira river is highlighted by its higher content of andalusite, with source attributed to the Amazon Craton (medium-to-high grade metamorphic rocks), while the Amazon river, upstream of the Madeira river mouth, has a signature of augite and hypersthene, that suggests an Andean provenance (volcanic rocks). Sands from the Madeira river can be tracked in the Amazon river by the increasing concentration in andalusite. OSL analysis of the light minerals fraction was used as an index of feldspar concentration and sedimentary history of quartz grains. Lower feldspar concentration and quartz grains with longer sedimentary history (higher OSL sensitivity) also point to a major contribution of cratonic sources for the sands in the Madeira river. While the sands from the Lower Madeira would be mainly supplied by cratonic rocks, previous work recognised that suspended sediments (silt and clay) are derived from Andean rocks. Therefore, we interpret a decoupling between the sources of sand and mud (silt and clay) under transport in the Madeira river. Andean sands (rich in augite and hypersthene) would be trapped in the foreland zones of the Beni and Mamoré tributaries. In the Amazon river sands, the low OSL sensitivity of the

Determination of K shell absorption jump factors and jump ratios of 3d transition metals by measuring K shell fluorescence parameters.

Science.gov (United States)

Kaçal, Mustafa Recep; Han, İbrahim; Akman, Ferdi

2015-01-01

Energy dispersive X-ray fluorescence technique (EDXRF) has been employed for measuring K-shell absorption jump factors and jump ratios for Ti, Cr, Fe, Co, Ni and Cu elements. The jump factors and jump ratios for these elements were determined by measuring K shell fluorescence parameters such as the Kα X-ray production cross-sections, K shell fluorescence yields, Kβ-to-Kα X-rays intensity ratios, total atomic absorption cross sections and mass attenuation coefficients. The measurements were performed using a Cd-109 radioactive point source and an Si(Li) detector in direct excitation and transmission experimental geometry. The measured values for jump factors and jump ratios were compared with theoretically calculated and the ones available in the literature. Copyright © 2014 Elsevier Ltd. All rights reserved.

Isochron reassessment of K-Ar dating from the West Carpathian crystalline complex

International Nuclear Information System (INIS)

Burchart, J.; Cambel, B.; Kral, J.

1987-01-01

Published K-Ar ages from the West Carpathian crystalline complex show an extreme dispersion of values. Therefore agreement of model data with Harper's (1970) isochron models was confronted and verified. On the basis of this analysis only a few numbers -isochron data which have real importance from the point of view of geological conditions - can be presented: 1. 394±24 m.y. -amphiboles, Male Karpaty Mts.; 2. 265±18 m.y. - amphiboles, gemerides; 3. 302±40 m.y. - biotites, core mountains; 4. 94±18 m.y. - biotites, veporides. Only isochron K-Ar ages of amphiboles approximate the time of their recrystallization. Isochron ages of biotites belong to the category of cooling ages and they represent the period since transition through isotherm of ca. 270 degC. The results of muscovite and feldspar dating cannot be interpreted by Harper's models. A substantial part of analyzed material is represented by analyses of whole rocks which are inapplicable to geochronological purposes. (author). 15 figs., 4 tabs., 53 refs

Magmatism during Gondwana breakup

DEFF Research Database (Denmark)

van der Meer, Quinten; Scott, J.M.; Waight, Tod Earle

2013-01-01

Newly determined mid-late Cretaceous 40Ar/39Ar ages on megacrystic kaersutite from lamprophyre dikes in central and north Westland (New Zealand) are presented. These ages (88 Ma, 86 Ma and 68 Ma) indicate that the intrusion of mafic dikes was not necessarily restricted to the previously establish...

Determining k channel activation curves from k channel currents often requires the goldman-hodgkin-katz equation.

Science.gov (United States)

Clay, John R

2009-01-01

Potassium ion current in nerve membrane, I(K), has traditionally been described by I(K) = g(K)(V - E(K)), where g(K) is the K ion conductance, V is membrane potential and E(K) is the K(+) Nernst potential. This description has been unchallenged by most investigators in neuroscience since its introduction almost 60 years ago. The problem with the I(K) approximately (V - E(K)) proportionality is that it is inconsistent with the unequal distribution of K ions in the intra- and extracellular bathing media. Under physiological conditions the intracellular K(+) concentration is significantly higher than the extracellular concentration. Consequently, the slope conductance at potentials positive to E(K) cannot be the same as that for potentials negative to E(K), as the linear proportionality between I(K) and (V - E(K)) requires. Instead I(K) has a non-linear dependence on (V - E(K)) which is well described by the Goldman-Hodgkin-Katz equation. The implications of this result for K(+) channel gating and membrane excitability are reviewed in this report.

A neutron diffraction study of ancient Greek ceramics

International Nuclear Information System (INIS)

Siouris, I.M.; Walter, J.

2006-01-01

Non-destructive neutron diffraction studies were performed on three 2nd-century BC archaeological pottery fragments from the excavation site of Neos Scopos, Serres, in North Greece. In all the 273 K diagrams quartz and feldspars phase fractions are dominant. Diopside and iron oxide phases were also identifiable. The diopside content is found to decrease with increasing quartz-feldspar compositions. Iron oxides containing minerals were found to be present and the phase compositions reflect upon the coloring of the samples. However, the different content compositions of the phases may suggest different regions of the original clay materials as well as different preparation techniques. The firing temperatures were determined to be in the range of 900-1000 deg. C

Experimental determination of the beam quality dependence factors, kQ, for ionization chambers used in photon and electron dosimetry

International Nuclear Information System (INIS)

Guerra, A.S.; Laitano, R.F.; Pimpinella, M.

1995-01-01

Dosimetry in radiotherapy with ionization chambers calibrated in 60 Co gamma beams in terms of absorbed dose to water, D W , can be performed if a factor conventionally denoted as k Q is known. The factor k Q depends on the beam quality and the chamber characteristics. Calculated values of the k Q factors for many types of ionization chamber have been recently published. In this work the experimental determination of the k Q factors for various ionization chambers was performed for 6 MV and 15 MV photon beams and for a 14 MeV electron beam. The k Q factors were determined by a procedure based on relative measurements performed with the ionization chamber and ferrous sulphate solution in 60 Co gamma radiation and accelerator beams, respectively. The experimental k Q values are compared with the calculated values so far published. Theoretical and experimental k Q values are in fairly good agreement. The uncertainty in the experimental k Q factors determined in this work is less than about 1%, that is, appreciably smaller than the uncertainty of about 1.5% reported for the calculated values. (Author)

indigenous manufacture and characterization of electrical porcelain

African Journals Online (AJOL)

Dr Obe

ohm cm, breakdown voltage of 26kV/mm, zero water absorption and dielectric constant between 9.2 and 10.8 within .... rising heat at a temperature of 1355 o. C and for ... thus the amount and composition of feldspar glass in the porcelain ... electrical measurements on the sample [4], ... 4.2 Experimental determination of the.

Determination of K shell absorption jump factors and jump ratios of 3d transition metals by measuring K shell fluorescence parameters

International Nuclear Information System (INIS)

Kaçal, Mustafa Recep; Han, İbrahim; Akman, Ferdi

2015-01-01

Energy dispersive X-ray fluorescence technique (EDXRF) has been employed for measuring K-shell absorption jump factors and jump ratios for Ti, Cr, Fe, Co, Ni and Cu elements. The jump factors and jump ratios for these elements were determined by measuring K shell fluorescence parameters such as the Kα X-ray production cross-sections, K shell fluorescence yields, Kβ-to-Kα X-rays intensity ratios, total atomic absorption cross sections and mass attenuation coefficients. The measurements were performed using a Cd-109 radioactive point source and an Si(Li) detector in direct excitation and transmission experimental geometry. The measured values for jump factors and jump ratios were compared with theoretically calculated and the ones available in the literature. - Highlights: • This work regard the K shell absorption jump ratios and jump factors of Ti, Cr, Fe, Co, Ni and Cu. • This paper presents the first measurement of these parameters using the experimental K shell fluorescence parameters. • A good agreement was found between experimental and theoretical values. • The EDXRF technique was suitable, precise and reliable for the measurement of these atomic parameters

TU-F-BRE-05: Experimental Determination of K Factor in Small Field Dosimetry

International Nuclear Information System (INIS)

Das, I; Akino, Y; Francescon, P

2014-01-01

Purpose: Small-field dosimetry is challenging due to charged-particle disequilibrium, source occlusion and more importantly finite size of detectors. IAEA/AAPM has published approach to convert detector readings to dose by k factor. Manufacturers have been trying to provide various types of micro-detectors that could be used in small fields. However k factors depends on detector perturbations and are derived using Monte Carlo simulation. PTW has introduced a microDiamond for small-field dosimetry. An experimental approach is presented to derive the k factor for this detector. Methods: PTW microDiamond is a small volume detector with 1.1 mm radius and 1.0 micron thick synthetic diamond. Output factors were measured from 1×1cm2 to 12×12 cm2 on a Varian machine at various depths using various micro-detectors with published k factors. Dose is calculated as reading * K. Assuming k factor is accurate, output factor should be identical with every micro-detectors. Hence published k values (Francescon et al Med Phys 35, 504-513,2008) were used to covert readings and then output factors were computed. Based on the converged curve from other detectors, k factor for microDiamond was computed versus field size. Results: Traditional output factors as ratio of readings normalized to 10×10 cm2 differ significantly for micro-detectors for fields smaller than 3×3 cm2 which are now being used extensively. When readings are converted to dose, the output factor is independent of detector. Based on this method, k factor for microDiamond was estimated to be nearly constant 0.993±0.007 over varied field sizes. Conclusion: Our method provides a unique opportunity to determine the k factor for any unknown detector. It is shown that even though k factor depends on machine type due to focal spot, however for fields ≥1×1 cm2 this method provides accurate evaluation of k factor. Additionally microDiamond could be used with assumption that k factor is nearly unity

Two novel kinetic techniques for determining relative V/K values for alternate substrates

International Nuclear Information System (INIS)

Anderson, V.; Kannan, B.

1986-01-01

The equilibrium perturbation method of determining kinetic isotope effects has been extended to permit the accurate measurement of relative V/K values for alternate substrates. In the Enoyl-CoA hydratase reaction at pH 8.0 the V/K for trans-2-pentenoyl-CoA (5:1(2t)-CoA) less than 10% greater than V/K for crotonyl-CoA while at pH 4.6 V/K for 5:1(2t)-CoA is over twice the V/K for crotonyl-CoA. This change in the ratio of V/K values indicates that there must be a pKa in the V/K pH profile for 5:1(2t)-CoA that is not characteristic of the free enzyme, a simple interpretation being 5:1(2t)-CoA is a sticky substrate. The pseudoequilibrium perturbation method is inaccurate when the ratio of V/K values exceeds 3. A companion pseudoequilibrium method is introduced where the initial conditions are constrained to produce an initial velocity of zero, rather than requiring the initial and final concentrations of the chromophoric substrate to be identical. The ratio of V/K values is simply the ratio of the concentration of the perturbant molecule to the equilibrium concentration of the nonperturbing analogue. This method combines the advantages of both the equilibrium perturbation method and of initial steady state measurements. The kinetic mechanism of L-3-hydroxyacyl-CoA dehydrogenase, an enzyme whose severe substrate inhibition and small primary 2 H isotope effect have made routine kinetic studies impractical, has been investigated by this method

k{sub 0}-INAA for determining chemical elements in bird feathers

Energy Technology Data Exchange (ETDEWEB)

Franca, Elvis J., E-mail: ejfranca@usp.b [CENA/USP, Centro de Energia Nuclear na Agricultura, Universidade of Sao Paulo, P.O. Box 97, 13400-970, Piracicaba, SP (Brazil); Fernandes, Elisabete A.N.; Fonseca, Felipe Y. [CENA/USP, Centro de Energia Nuclear na Agricultura, Universidade of Sao Paulo, P.O. Box 97, 13400-970, Piracicaba, SP (Brazil); Antunes, Alexsander Z. [IF, Instituto Florestal do Estado de Sao Paulo, Rua do Horto 931, Horto Florestal 02377-000, Sao Paulo, SP (Brazil); Bardini Junior, Claudiney; Bacchi, Marcio A.; Rodrigues, Vanessa S.; Cavalca, Isabel P.O. [CENA/USP, Centro de Energia Nuclear na Agricultura, Universidade of Sao Paulo, P.O. Box 97, 13400-970, Piracicaba, SP (Brazil)

2010-10-11

The k{sub 0}-method instrumental neutron activation analysis (k{sub 0}-INAA) was employed for determining chemical elements in bird feathers. A collection was obtained taking into account several bird species from wet ecosystems in diverse regions of Brazil. For comparison reason, feathers were actively sampled in a riparian forest from the Marins Stream, Piracicaba, Sao Paulo State, using mist nets specific for capturing birds. Biological certified reference materials were used for assessing the quality of analytical procedure. Quantification of chemical elements was performed using the k{sub 0}-INAA Quantu Software. Sixteen chemical elements, including macro and micronutrients, and trace elements, have been quantified in feathers, in which analytical uncertainties varied from 2% to 40% depending on the chemical element mass fraction. Results indicated high mass fractions of Br (max=7.9 mg kg{sup -1}), Co (max=0.47 mg kg{sup -1}), Cr (max=68 mg kg{sup -1}), Hg (max=2.79 mg kg{sup -1}), Sb (max=0.20 mg kg{sup -1}), Se (max=1.3 mg kg{sup -1}) and Zn (max=192 mg kg{sup -1}) in bird feathers, probably associated with the degree of pollution of the areas evaluated. In order to corroborate the use of k{sub 0}-INAA results in biomonitoring studies using avian community, different factor analysis methods were used to check chemical element source apportionment and locality clustering based on feather chemical composition.

Experimental determination of net protein charge and A(tot) and K(a) of nonvolatile buffers in canine plasma.

Science.gov (United States)

Constable, Peter D; Stämpfli, Henry R

2005-01-01

Acid-base abnormalities frequently are present in sick dogs. The mechanism for an acid-base disturbance can be determined with the simplified strong ion approach, which requires accurate values for the total concentration of plasma nonvolatile buffers (A(tot)) and the effective dissociation constant for plasma weak acids (K(a)). The aims of this study were to experimentally determine A(tot) and K(a) values for canine plasma. Plasma was harvested from 10 healthy dogs; the concentrations of quantitatively important strong ions (Na+, K+, Ca2+, Mg2+, Cl-, L-lactate) and nonvolatile buffer ions (total protein, albumin, phosphate) were determined; and the plasma was tonometered with CO2 at 37 degrees C. Strong ion difference (SID) was calculated from the measured strong ion concentrations, and nonlinear regression was used to estimate values for A(tot) and K(a), which were validated with data from an in vitro and in vivo study. Mean (+/- SD) values for canine plasma were A(tot) = (17.4 +/- 8.6) mM (equivalent to 0.273 mmol/g of total protein or 0.469 mmol/g of albumin); K(a) = (0.17 +/- 0.11) x 10(-7); pK(a) = 7.77. The calculated SID for normal canine plasma (pH = 7.40; P(CO2) = 37 mm Hg; [total protein] = 64 g/L) was 27 mEq/L. The net protein charge for normal canine plasma was 0.25 mEq/g of total protein or 0.42 mEq/g of albumin. Application of the experimentally determined values for A(tot), K(a), and net protein charge should improve understanding of the mechanism for complex acid-base disturbances in dogs.

Structural determinants of the outer shell of β-carboxysomes in Synechococcus elongatus PCC 7942: roles for CcmK2, K3-K4, CcmO, and CcmL.

Directory of Open Access Journals (Sweden)

Benjamin D Rae

Full Text Available Cyanobacterial CO(2-fixation is supported by a CO(2-concentrating mechanism which improves photosynthesis by saturating the primary carboxylating enzyme, ribulose 1, 5-bisphosphate carboxylase/oxygenase (RuBisCO, with its preferred substrate CO(2. The site of CO(2-concentration is a protein bound micro-compartment called the carboxysome which contains most, if not all, of the cellular RuBisCO. The shell of β-type carboxysomes is thought to be composed of two functional layers, with the inner layer involved in RuBisCO scaffolding and bicarbonate dehydration, and the outer layer in selective permeability to dissolved solutes. Here, four genes (ccmK2-4, ccmO, whose products were predicted to function in the outer shell layer of β-carboxysomes from Synechococcus elongatus PCC 7942, were investigated by analysis of defined genetic mutants. Deletion of the ccmK2 and ccmO genes resulted in severe high-CO(2-requiring mutants with aberrant carboxysomes, whilst deletion of ccmK3 or ccmK4 resulted in cells with wild-type physiology and normal ultrastructure. However, a tandem deletion of ccmK3-4 resulted in cells with wild-type carboxysome structure, but physiologically deficient at low CO(2 conditions. These results revealed the minimum structural determinants of the outer shell of β-carboxysomes from this strain: CcmK2, CcmO and CcmL. An accessory set of proteins was required to refine the function of the pre-existing shell: CcmK3 and CcmK4. These data suggested a model for the facet structure of β-carboxysomes with CcmL forming the vertices, CcmK2 forming the bulk facet, and CcmO, a "zipper protein," interfacing the edges of carboxysome facets.

User's guide for the portable microprocessor equipment: 'KfK K-edge densitometer' for quantitative determination of Th, U, Np, Pu, Am in solutions

International Nuclear Information System (INIS)

Michel-Piper, I.; Matussek, P.

1985-06-01

This report describes the hardware and software features, and the use of the microprocessor-controlled multichannel analyzer system SILENA + IRIS. The self-contained portable system, which permits independent accumulation and evaluation of spectral data from the KfK K-edge densitometer, provides one of the possible means for the authentication of resident instruments by safeguards inspectors. The 'K-Edge' program, written in PL/M language for compatibility with the system's firmware, allows fully automated assays of heavy element concentrations in solutions by means of X-ray absorption edge spectrometry. It is primarily intended for highly accurate determinations of the U and Pu content in process- and product solutions of a reprocessing plant. (orig.)

Geology and mineralization of the Jabalat alkali-feldspar granite, northern Asir region, Kingdom of Saudi Arabia

Science.gov (United States)

Al Tayyar, Jaffar; Jackson, Norman J.; Al-Yazidi, Saeed

The Jabalat post-tectonic granite pluton is composed of albite- and oligoclase-bearing, low-calcium, F-, Sn- and Rb-rich subsolvus granites. These granites display evidence of late-magmatic, granitophile- and metallic-element specialization, resulting ultimately in the development of post-magmatic, metalliferous hydrothermal systems characterized by a Mo sbnd Sn sbnd Cu sbnd Pb sbnd Zn sbnd Bi sbnd Ag sbnd F signature. Two main types of mineralization are present within the pluton and its environs: (1) weakly mineralized felsic and aplitic dikes and veins enhanced in Mo, Bi, Ag, Pb and Cu; and (2) pyrite—molybdenite—chalcopyrite-bearing quartz and quartz—feldspar veins rich in Mo, Sn, Bi, Cu, Zn and Ag. A satellite stock, 3 km north of the main intrusion, is composed of fine-grained, miarolitic, muscovite—albite—microcline (microperthite) granite. The flanks of this intrusion and adjacent dioritic rocks are greisenized and highly enriched in Sn, Bi and Ag. Quartz veins which transect the satellite stock contain molybdenite and stannite.

Structure determination of K2ZnBr4 at 291 and 144 K

International Nuclear Information System (INIS)

Fabry, J.; Breczewski, T.; Zuniga, F.J.; Arnaiz, A.R.

1993-01-01

The room-temperature phase of K 2 ZnBr 4 is isomorphous with Sr 2 GeS 4 (P2 1 /m) while the low-temperature structure (P2 1 ) is slightly distorted [the phase transition occurs at 155 K]. Both structures contain highly deformed tetrahedral [ZnBr 4 ] 2- molecules with Br(3)-Zn-Br(3') angles of 103.06(5) and 102.49(9) at 291 and 144 K, respectively. This distortion is caused by the repulsion of Br atoms whose distance 3.712(1) and 3.661(2) A at 291 and 144 K, respectively, is below the Br-Br van der Waals distance (3.9 A). The phase transition is accompanied by minor shifts of cations and [ZnBr 4 ] 2- tetrahedra which are simultaneously rotated about a small angle. Below the phase transition point an inversion twin develops whose twin-fraction parameter was refined to 0.459(65). (orig.)

Application of Fast Neutron Activation to Determinate of N, P and K Element Contents in the Sludge

International Nuclear Information System (INIS)

Supriyatni E; Yazid M; Nuraini E; Sunardi

2003-01-01

The application of fast neutron activation to determinate of N, P and K element contents in the sludge has been performed. The aim of this research is to determine the content of N, P and K elements in the sludge for the possibility of reuse as organic fertilizer. Sludge sample was taken from waste water retainer at Bantul Waste Water Treatment Plant. The sample was dried and ground, then irradiated using 14.7 MeV fast neutron from neutron generator. Result was qualitatively and quantitatively analyses using gamma spectrometer. The result showed that the sludge contains N with energy 511 keV, P with energy 1778 keV and K with energy 1273 keV. The concentration of N is (4.101 ± 0.007) mg/g, P is = (640.510 ± 14.34) mg/g and K = (3.045 ± 0.064) mg/g. (author)

Determination of 40K in water samples

International Nuclear Information System (INIS)

Delgado, C. E.; Miranda C, L.; Cuevas J, A. K.; Vega C, H. R.

2014-10-01

The natural water used for human consumption comes from different sources, which may contain suspended solids in varying proportions. In groundwater, the source of suspended solids is related to the dissolution of mineral strata by the waters and leaching of rocks. Also, the radioactivity could concentrate on the bodies of slow-moving water that eventually could present a risk to ecosystems, as well as for the consumer. The water usually contains several natural radionuclides as: tritium, radon, radio, uranium isotopes, etc. The objective of this study was to evaluate the concentration of 40 K in water from different areas of Zacatecas state (Mexico). Four water samples were taken in triplicate from different areas; the 40 K concentration was measured with a spectrum metric system of gamma radiation with NaI (Tl) scintillation detector of 7.62 cm. In the measuring process a standard was prepared using water and KCl analytic grade where the 40 K concentration is 6.25 mol/Lt adding 250 mg/ml of potassium. Also the system was calibrated in energy using 3 point sources of 137 Cs, diameter 22 Na and 7.62 cm of height, using containers Marinelli and 60 Co. In the obtained spectra was observed that the photon of 1.432 MeV that emits the 40 K when decaying is the most important. The highest concentration was of 123 ± 5.2 Bq/lt and the lowest was of 9 ± 0.4 Bq/lt. Under the standards of drinking water, an amount of 40 K deposits an effective dose which contributes to annual dose received by people. (Author)

An algorithm for determining the K-best solutions of the one-dimensional Knapsack problem

Directory of Open Access Journals (Sweden)

Horacio Hideki Yanasse

2000-06-01

Full Text Available In this work we present an enumerative scheme for determining the K-best solutions (K > 1 of the one dimensional knapsack problem. If n is the total number of different items and b is the knapsack's capacity, the computational complexity of the proposed scheme is bounded by O(Knb with memory requirements bounded by O(nb. The algorithm was implemented in a workstation and computational tests for varying values of the parameters were performed.Neste trabalho apresenta-se um esquema enumerativo para se determinar as K-melhores (K > 1 soluções para o problema da mochila unidimensional. Se n é o número total de itens diferentes e b é a capacidade da mochila, a complexidade computacional do esquema proposto é limitado por O(Knb. O algoritmo foi implementado em uma estação de trabalho e testes computacionais foram realizados variando-se diferentes parâmetros do problema.

Localization and Molecular Determinants of the Hanatoxin Receptors on the Voltage-Sensing Domains of a K+ Channel

Science.gov (United States)

Li-Smerin, Yingying; Swartz, Kenton J.

2000-01-01

Hanatoxin inhibits voltage-gated K+ channels by modifying the energetics of activation. We studied the molecular determinants and physical location of the Hanatoxin receptors on the drk1 voltage-gated K+ channel. First, we made multiple substitutions at three previously identified positions in the COOH terminus of S3 to examine whether these residues interact intimately with the toxin. We also examined a region encompassing S1–S3 using alanine-scanning mutagenesis to identify additional determinants of the toxin receptors. Finally, guided by the structure of the KcsA K+ channel, we explored whether the toxin interacts with the peripheral extracellular surface of the pore domain in the drk1 K+ channel. Our results argue for an intimate interaction between the toxin and the COOH terminus of S3 and suggest that the Hanatoxin receptors are confined within the voltage-sensing domains of the channel, at least 20–25 Å away from the central pore axis. PMID:10828242

Direct and indirect methods for the determination of vitamin K3 using differential pulse polarography and application to pharmaceuticals.

Science.gov (United States)

Somer, Güler; Doğan, Mehmet

2008-11-01

Two methods for the determination of vitamin K(3) have been developed. Vitamin K(3) in its oxidized form is determined by direct and indirect methods. Its standard solution was prepared by the indirect method using Ti(III) as reducing agent. For this purpose vitamin K(3) (menadion) in a clinical injection solution, which is in its hydroquinone form in the presence of sulfite, is oxidized with oxygen. In 0.2 M HAc and 0.02 M HCl electrolyte vitamin K(3) and Ti(IV) have reduction peaks at -0.58 V at -0.82 V respectively. The reaction between Ti(III) and vitamin takes place quantitatively in a medium of 0.2 M HAc and 0.002 M HCl. After the reduction, the reaction product Ti(IV) is followed from its polarographic peak at about -0.82 V. The most important result in this work is that, with this method vitamin K(3) can be standardized and after standardization this solution can be used for the direct determination in routine analysis with a very simple and fast method, using only the peak at -0.71 V in 0.2 M HAc medium. Both direct and indirect methods have been used for the determination of Vitamin K(3) in a clinical injection solution. The limit of quantification (LOQ) was 1.5x10(-6) M and in both methods the detection limit found was 7x10(-7) M.

Lead isotopic study of aplites from the Precambrian basement rocks near Ibadan, southwestern Nigeria

International Nuclear Information System (INIS)

Oversby, V.M.

1975-01-01

Pb isotopic compositions for three total-rock samples of aplite and their constituent K-feldspars from the Nigerian basement assemblage near Ibadan show lead homogenization during the Pan-African thermo-tectonic event. A secondary isochron formed by the K-feldspars data points is used to calculate a primary age of about 2750 m.y. for the aplites. The aplites do not register any Pb isotopic effect from the intrusion of granite gneiss in the area at 2330m.y. (Auth.)

Determining the K coefficient to leaf area index estimations in a tropical dry forest

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Magalhães, Sarah Freitas; Calvo-Rodriguez, Sofia; do Espírito Santo, Mário Marcos; Sánchez Azofeifa, Gerardo Arturo

2018-03-01

Vegetation indices are useful tools to remotely estimate several important parameters related to ecosystem functioning. However, improving and validating estimations for a wide range of vegetation types are necessary. In this study, we provide a methodology for the estimation of the leaf area index (LAI) in a tropical dry forest (TDF) using the light diffusion through the canopy as a function of the successional stage. For this purpose, we estimated the K coefficient, a parameter that relates the normalized difference vegetation index (NDVI) to LAI, based on photosynthetically active radiation (PAR) and solar radiation. The study was conducted in the Mata Seca State Park, in southeastern Brazil, from 2012 to 2013. We defined four successional stages (very early, early, intermediate, and late) and established one optical phenology tower at one plot of 20 × 20 m per stage. Towers measured the incoming and reflected solar radiation and PAR for NDVI calculation. For each plot, we established 24 points for LAI sampling through hemispherical photographs. Because leaf cover is highly seasonal in TDFs, we determined ΔK (leaf growth phase) and K max (leaf maturity phase). We detected a strong correlation between NDVI and LAI, which is necessary for a reliable determination of the K coefficient. Both NDVI and LAI varied significantly between successional stages, indicating sensitivity to structural changes in forest regeneration. Furthermore, the K values differed between successional stages and correlated significantly with other environmental variables such as air temperature and humidity, fraction of absorbed PAR, and soil moisture. Thus, we established a model based on spectral properties of the vegetation coupled with biophysical characteristics in a TDF that makes possible to estimate LAI from NDVI values. The application of the K coefficient can improve remote estimations of forest primary productivity and gases and energy exchanges between vegetation and atmosphere

CCQM-K11.2 determination of glucose in human serum and CCQM-K12.2 determination of creatinine in human serum

Science.gov (United States)

Wise, Stephen A.; Phinney, Karen W.; Duewer, David L.; Sniegoski, Lorna T.; Welch, Michael J.; Pritchett, Jeanita; Pabello, Guiomar; Avila Calderon, Marco A.; Balderas, Miryan; Qinde, Liu; Kooi, Lee Tong; Rego, Eliane; Garrido, Bruno; Allegri, Gabriella; de La Cruz, Marcia; Barrabin, Juliana; Monteiro, Tânia; Lee, Hwashim; Kim, Byungjoo; Delatour, Vincent; Peignaux, Maryline; Kawaguchi, Migaku; Bei, Xu; Can, Quan; Nammoonnoy, Jintana; Schild, Katrin; Ohlendorf, Rüdiger; Henrion, Andre; Ceyhan Gören, Ahmet; Yılmaz, Hasibe; Bilsel, Mine; Konopelko, L.; Krylov, A.; Lopushanskaya, E.

2018-01-01

Glucose and creatinine are two of the most frequently measured substances in human blood/serum for assessing the health status of individuals. Because of their clinical significance, CCQM-K11 glucose in human serum and CCQM-K12 creatinine in human serum were the fourth and fifth key comparisons (KCs) performed by the Organic Analysis Working Group (OAWG). These KCs were conducted in parallel and were completed in 2001. The initial subsequent KCs for glucose, CCQM-K11.1, and creatinine, CCQM-K12.1, were completed in 2005. Measurements for the next KCs for these two measurands, CCQM-K11.2 and CCQM-K12.2, were completed in 2013. While designed as subsequent KCs, systematic discordances between the participants' and the anchor institution's results in both comparisons lead the OAWG to request reference results from two experienced laboratories that had participated in the 2001 comparisons. Based on the totality of the available information, the OAWG converted both CCQM-K11.2 and CCQM-K12.2 to 'Track C' KCs where the key comparison reference value is estimated by consensus. These comparisons highlighted that carrying out comparisons for complex chemical measurements and expecting to be able to treat them under the approaches used for formal CIPM subsequent comparisons is not an appropriate strategy. The approach used here is a compromise to gain the best value from the comparison; it is not an approach that will be used in the future. Instead, the OAWG will focus on Track A and Track C comparisons that are treated as stand-alone entities. Participation in CCQM-K11.2 demonstrates a laboratory's capabilities to measure a polar (pKow > 2), low molecular mass (100 g/mol to 500 g/mol) metabolite in human serum at relatively high concentrations (0.1 mg/g to 10 mg/g). Participation in CCQM-K12.2 demonstrates capabilities to measure similar classes of metabolites at relatively low concentrations (1 μg/g to 30 μg/g). The capabilities required for the analysis of complex

Rapakivi texture formation via disequilibrium melting in a contact partial melt zone, Antarctica

Science.gov (United States)

Currier, R. M.

2017-12-01

In the McMurdo Dry Valleys of Antarctica, a Jurassic aged dolerite sill induced partial melting of granite in the shallow crust. The melt zone can be traced in full, from high degrees of melting (>60%) along the dolerite contact, to no apparent signs of melting, 10s of meters above the contact. Within this melt zone, the well-known rapakivi texture is found, arrested in various stages of development. High above the contact, and at low degrees of melting, K-feldspar crystals are slightly rounded and unmantled. In the lower half of the melt zone, mantles of cellular textured plagioclase appear on K-feldspar, and thicken towards the contact heat source. At the highest degrees of melting, cellular-textured plagioclase completely replaces restitic K-feldspar. Because of the complete exposure and intact context, the leading models of rapakivi texture formation can be tested against this system. The previously proposed mechanisms of subisothermal decompression, magma-mixing, and hydrothermal exsolution all fail to adequately describe rapakivi generation in this melt zone. Preferred here is a closed system model that invokes the production of a heterogeneous, disequilibrium melt through rapid heating, followed by calcium and sodium rich melt reacting in a peritectic fashion with restitic K-feldspar crystals. This peritectic reaction results in the production of plagioclase of andesine-oligoclase composition—which is consistent with not just mantles in the melt zone, but globally as well. The thickness of the mantle is diffusion limited, and thus a measure of the diffusive length scale of sodium and calcium over the time scale of melting. Thermal modeling provides a time scale of melting that is consistent with the thickness of observed mantles. Lastly, the distribution of mantled feldspars is highly ordered in this melt zone, but if it were mobilized and homogenized—mixing together cellular plagioclase, mantled feldspars, and unmantled feldspars—the result would be

Determination of Psub(K) values to the 172, 103 and 97 keV levels and the fluorescence yield. omega. sub(K) of Eu after electron capture by /sup 153/Gd

Energy Technology Data Exchange (ETDEWEB)

Singh, K; Grewal, B S; Sahota, H S [Punjabi Univ., Patiala (India). Dept. of Physics

1985-03-01

From an analysis of K x-ray-..gamma..-ray sum peaks observed with an intrinsic Ge detector the K-capture probabilities (Psub(K)) to the 172, 103 and 97 keV levels in the decay of /sup 153/Gd have been determined; these yield an electron-capture energy Qsub(EC)=245 +- 2. The K-capture probability to the 172 keV level differs significantly from that found in the literature. With these results the K-shell fluorescence yield of Eu is ..omega..sub(K)=0.935 +- 0.019.

Determination of Na+ and K+ ions in the high-level liquid waste by ion chromatography (IC)

International Nuclear Information System (INIS)

Chen Lianzhong; Ma Guilan

1992-01-01

The determination of Na + and k + ions in the high-level liquid waste is investigated using ion chromatography. In order to protect the low capacity ion exchange resin in single column IC and remove the transition metal as well as other heavy metal ions that are contained in liquid waste, the pretreatment column with EDTA chelating resin is used. Those impurity metal ions are strongly absorbed by EDTA chelating resin and 100% of Na + and K + ions in the solution are eluted. The ability of the decontamination of EDTA chelating resin is satisfactory. The sample of the high-level liquid waste is diluted appropriately, then an aliquot of the sample is passed through the pretreatment column with EDTA chelating resin, the eluate is analysed by single column ion chromatography. The precision of this method is better than 5% for the determination of Na + and K + ions (at μg· ml -1 level)

A strategy for determination of test intervals of k-out-of-n multi-channel systems

International Nuclear Information System (INIS)

Cho, S.; Jiang, J.

2007-01-01

State space models for determination of the optimal test frequencies for k-out-of-n multi channel systems are developed in this paper. The analytic solutions for the optimal surveillance test frequencies are derived using the Markov process technique. The solutions show that an optimal test frequency which maximizes the target probability can be determined by decomposing the system states to 3 states based on the system configuration and success criteria. Examples of quantification of the state probabilities and the optimal test frequencies of a three-channel system and a four-channel system with different success criteria are presented. The strategy for finding the optimal test frequency developed in this paper can generally be applicable to any k-out-of-n multi-channel standby systems that involve complex testing schemes. (author)

Optical dating of eolian deposits since the last interglacial along the northern margin of the Chinese Loess Plateau

Science.gov (United States)

Lü, Tongyan; Sun, Jimin; Gong, Zhijun

2018-04-01

Understanding the chronology of eolian sand-loess-paleosol sequences along the northern margin of the Chinese Loess Plateau (CLP) is crucial for comprehending climate change and the advance and retreat of the adjacent Mu Us desert. In this study, a sand-loess-soil sequence from the northern margin of the CLP was studied by applying the single aliquot regenerative (SAR) protocol to quartz grains, and the multi-elevated-temperature post-IR IRSL (MET-pIRIR) protocol to K-feldspar grains. For equivalent dose (De) determination, 63-90 μm quartz and K-feldspar grains were used. Our results indicate that the MET-pIRIR ages of K-feldspar grains in this sequence range from 94.4 ± 7.0 ka to 148.3 ± 13.3 ka for the last interglacial paleosol (S1); for the upper part of the section, quartz-based SAR-OSL dating was used, yielding ages spanning from 5.8 ± 0.4 ka to 35.9 ± 4.1 ka. After cross-checking these results with previously-reported isochron OSL and TL ages, the reliability of the MET-pIRIR protocol when applied to the last interglacial paleosol was confirmed. Based on a new OSL chronology of the Shimao profile, the studied eolian deposits can be broadly correlated with the last glacial-interglacial cycle, but their dating also points to sedimentary hiatuses occurring at 94.4 ka, 35.9 ka and 5.8 ka, due most probably to strong wind erosion caused by intensified cold-dry winter monsoonal circulations during the last glacial maxima.

The formation of the Late Cretaceous Xishan Sn-W deposit, South China: Geochronological and geochemical perspectives

Science.gov (United States)

Zhang, Lipeng; Zhang, Rongqing; Hu, Yongbin; Liang, Jinlong; Ouyang, Zhixia; He, Junjie; Chen, Yuxiao; Guo, Jia; Sun, Weidong

2017-10-01

The Xishan Sn-W deposit is spatially related to K-feldspar granites in the Yangchun basin, western Guangdong Province, South China. LA-ICP-MS zircon U-Pb dating for the Xishan pluton defines an emplacement age of 79 Ma (78.1 ± 0.9 Ma; 79.0 ± 1.2 Ma; 79.3 ± 0.8 Ma), consistent with the mineralization age of the Xishan Sn-W deposit constrained by molybdenite Re-Os isochron age (79.4 ± 4.5 Ma) and LA-ICP-MS cassiterite U-Pb ages (78.1 ± 0.9 Ma and 79.0 ± 1.2 Ma) for the cassiterite-quartz vein. These indicate a close genetic relationship between the granite and Sn-W mineralization. The Xishan K-feldspar granites have geochemical characteristics of A-type granites, e.g., high total alkali (Na2O + K2O = 7.88-10.07 wt.%), high Ga/Al ratios (10000*Ga/Al > 2.6) and high Zr + Nb + Ce + Y concentrations (> 350 ppm). They are further classified as A2-type granites. The whole-rock isotopic compositions of K-feldspar granites (initial 87Sr/86Sr = 0.705256-0.706181; εNd(t) = - 5.4 to - 4.8) and zircon εHf(t) values (- 7.8 to 2.0) suggest a mixed magma source. The low zircon Ce4 +/Ce3 + ratios (12-88) of K-feldspar granites suggest low oxygen fugacities, which is key for enrichment of tin in primary magmas. The K-feldspar granites have experienced strong differentiation as indicated by their high Rb/Sr and K/Rb ratios, and low Nb/Ta and Zr/Hf ratios, which play an important role in ore-forming element transportation and concentration. A-type granite characteristics of the Xishan pluton show that it formed in an extensional environment. The high F and low Cl characteristics of the K-feldspar granite are most probably attributed to slab rollback. In the Late Cretaceous, the Xishan Sn-W deposit was located near the interaction of the circum-Pacific and the Tethys tectonic realms. Late Cretaceous Sn-W deposits, including the Xishan deposit, form an EW-trending belt from Guangdong to Yunnan Province in South China. This belt is in accordance with the direction of the Neo

Experimental determination of beam quality conversion factors kQ in clinical photon beams using ferrous sulphate (Fricke) dosimetry

International Nuclear Information System (INIS)

Palm, A.; Mattsson, Olof

2002-01-01

The implementation of protocols based on absorbed dose to water standards requires beam quality conversion factors, k Q . Calculated values of k Q are available for ionization chambers used for reference dosimetry. Ideally, k Q should be experimentally determined at the same beam qualities as that of the user. In this work we measure k Q factors in clinical photon beams and compare them with calculated and measured values. Beam quality conversion factors are determined for clinical photon beams of nominal energies 4 MV, 6 MV, 15 MV, and 25 MV, for commonly used cylindrical ionization chambers. Twelve chambers of eight different types are used. For three of them, no experimental data have previously been available. The experimental procedure is based on measurements with ionization chambers and Fricke dosimetry in the reference beam ( 60 Co γ radiation) and in clinical linear accelerator beams. The k Q values determined in this work generally agree within 0.5% with previously reported experimental values both when %dd(10) x and TPR 20,10 are used for beam quality specification. The agreement with calculated data is generally within 0.5%, except for the 15 MV beam. For this beam the measured values are usually between 0.5% and 1% lower than the data taken from the TG-51 protocol or the TRS-398 code of practice. For three NE2571 chambers and three NE2581 chambers, the maximum observed deviation of individual k Q values is 0.2% and 0.4%, respectively

Determining K+ channel activation curves from K+ channel currents often requires the Goldman-Hodgkin-Katz equation

Directory of Open Access Journals (Sweden)

john r Clay

2009-12-01

Full Text Available Potassium ion current in nerve membrane, IK, has traditionally been described by IK = gK(V-EK, where gK is the K ion conductance, V is membrane potential, and EK is the K+ Nernst potential. This description has been unchallenged by most investigators in neuroscience since its introduction almost sixty years ago. The problem with the IK ~ (V-EK proportionality is that it is inconsistent with the unequal distribution of K ions in the intra- and extracellular bathing media. Under physiological conditions the intracellular K+ concentraion is significantly higher than the extracellular concentration. Consequently, the slope conductance at potentials positive to EK cannot be the same as that for potentials negative to EK, as the linear proportionality requires. Instead IK has a non-linear dependence on (V-EK which is well described by the Goldman-Hodgkin-Katz equation. The implications of this result for K+ channel gating and membrane excitability are reviewed in this report.

Determination of multi-element in marine sediment samples collected in Angola by the k0-NAA technique

International Nuclear Information System (INIS)

Teixeira, M.C.P.; Ho Manh Dung; Cao Dong Vu; Nguyen Thi Sy; Nguyen Thanh Binh; Vuong Huu Tan

2006-01-01

The marine sediment samples were designed to collect in Angola for marine environmental pollution study. The k 0 -standardization method of neutron activation analysis (k 0 -NAA) on Dalat research reactor has been developed to determine of multi-element in the Angola marine sediment samples. The samples were irradiated in cell 7-1 for short- and middle-lived nuclides and rotary specimen rack for long-lived nuclides. The irradiation facilities were characterized for neutron spectrum parameters and post-activated samples were measured on the calibrated gamma-ray spectrometers using HPGe detectors. The analytical results for 9 marine sediment samples with 27 elements: Al, As, Br, Ca, Ce,Cl, Co, Cs, Dy, Fe, Hf, I, K, Mg, Mn, Na, Rb, Sb, Sc, Se, Sm, Th, Ti, U, V and Zn in term of mean concentration, standard deviation and their content range are shown in the report. The analytical quality assurance was done by analysis of a Japan's certified reference material namely marine sediment NMIJ-CRM-7302a. These preliminary results revealed that the k 0 -NAA technique on the Dalat research reactor is a good analytical technique for determination of multi-element in the marine sediment samples. Some heavy metals and trace elements determined in this work possibly connected to the human activities at the sampling region. (author)

Diffusion in the Muscovite 40K Decay System (Invited)

Science.gov (United States)

Harrison, T. M.

2010-12-01

The considerable potential of muscovite for thermochronological applications is beginning to be fully exploited following the belated publication of Ar kinetic data. Muscovite’s high potassium content, low solubility for excess 40Ar*, and ubiquitous presence in regionally metamorphosed terranes make it an important phase for 40Ar/39Ar thermochronometry, particularly in light of recognition that both age spectra and vacuum-step-heating-derived 39Ar Arrhenius plots reflect Ar release via the same volume diffusion mechanism. Thus instead of assuming a nominal closure temperature to estimate a single T-t datum, continuous and accurate thermal histories can be inferred in a similar fashion to that well-documented for K-feldspar using the multi-diffusion domain (MDD) model. The Arrhenius parameters for Ar diffusion in muscovite (E=64 kcal/mol, Do=4 cm2/s) correspond to an effective intragrain closure temperature range of ~500 to 300oC for ca. 100 μm grains cooling at ~10oC/Ma at 5 kbar. However, even greater exploitation of the 40K decay system remains possible as only one of every ten 40K atoms decay to 40Ar. The other 90% decay to 40Ca giving the 40K-40Ca branch, in principle, greater sensitivity for dating high K/Ca minerals such as muscovite. The advent of the ‘double-plus’ SIMS 40K++-40Ca++ dating method, which permits analysis of Ca isotopes at an MRP of ~4k rather than the ~25k required for full separation of 40K+ from 40Ca+, opens up the prospect of directly revealing 40K-40Ca closure profiles in muscovite (as opposed to their indirect inference from inversion of 40Ar/39Ar data through the MDD model) at a gain of enhanced precision and accuracy in thermal history reconstruction. We have used SIMS to observe K-Ca age variations in natural muscovites pressed into In. Translating this data into thermal history information, however, requires knowledge of the Arrhenius parameters for Ca tracer diffusion in muscovite. We are undertaking hydrothermal piston

Determination of K shell absorption jump factors and jump ratios in the elements between Tm(Z = 69) and Os(Z = 76) by measuring K shell fluorescence parameters

International Nuclear Information System (INIS)

Kaya, N.; Tirasoglu, E.; Apaydin, G.

2008-01-01

The K shell absorption jump factors and jump ratios have been measured in the elements between Tm (Z = 69) and Os(Z = 76) without having any mass attenuation coefficient at the upper and lower energy branch of the K absorption edge. The jump factors and jump ratios for these elements have been determined by measuring K shell fluorescence parameters such as the total atomic absorption cross-sections, the K α X-ray production cross-sections, the intensity ratio of the K β and K α X-rays and the K shell fluorescence yields. We have performed the measurements for the calculations of these values in attenuation and direct excitation experimental geometry. The K X-ray photons are excited in the target using 123.6 keV gamma-rays from a strong 57 Co source, and detected with an Ultra-LEGe solid state detector with a resolution 0.15 keV at 5.9 keV. The measured values have been compared with theoretical and others' experimental values. The results have been plotted versus atomic number

Determination of K shell absorption jump factors and jump ratios in the elements between Tm( Z = 69) and Os( Z = 76) by measuring K shell fluorescence parameters

Science.gov (United States)

Kaya, N.; Tıraşoğlu, E.; Apaydın, G.

2008-04-01

The K shell absorption jump factors and jump ratios have been measured in the elements between Tm ( Z = 69) and Os( Z = 76) without having any mass attenuation coefficient at the upper and lower energy branch of the K absorption edge. The jump factors and jump ratios for these elements have been determined by measuring K shell fluorescence parameters such as the total atomic absorption cross-sections, the K α X-ray production cross-sections, the intensity ratio of the K β and K α X-rays and the K shell fluorescence yields. We have performed the measurements for the calculations of these values in attenuation and direct excitation experimental geometry. The K X-ray photons are excited in the target using 123.6 keV gamma-rays from a strong 57Co source, and detected with an Ultra-LEGe solid state detector with a resolution 0.15 keV at 5.9 keV. The measured values have been compared with theoretical and others' experimental values. The results have been plotted versus atomic number.

Chemical weathering of a marine terrace chronosequence, Santa Cruz, California I: Interpreting rates and controls based on soil concentration-depth profiles

Science.gov (United States)

White, A.F.; Schulz, M.S.; Vivit, D.V.; Blum, A.E.; Stonestrom, David A.; Anderson, S.P.

2008-01-01

The spatial and temporal changes in element and mineral concentrations in regolith profiles in a chronosequence developed on marine terraces along coastal California are interpreted in terms of chemical weathering rates and processes. In regoliths up to 15 m deep and 226 kyrs old, quartz-normalized mass transfer coefficients indicate non-stoichiometric preferential release of Sr > Ca > Na from plagioclase along with lesser amounts of K, Rb and Ba derived from K-feldspar. Smectite weathering results in the loss of Mg and concurrent incorporation of Al and Fe into secondary kaolinite and Fe-oxides in shallow argillic horizons. Elemental losses from weathering of the Santa Cruz terraces fall within the range of those for other marine terraces along the Pacific Coast of North America. Residual amounts of plagioclase and K-feldspar decrease with terrace depth and increasing age. The gradient of the weathering profile bs is defined by the ratio of the weathering rate, R to the velocity at which the profile penetrates into the protolith. A spreadsheet calculator further refines profile geometries, demonstrating that the non-linear regions at low residual feldspar concentrations at shallow depth are dominated by exponential changes in mineral surface-to-volume ratios and at high residual feldspar concentrations, at greater depth, by the approach to thermodynamic saturation. These parameters are of secondary importance to the fluid flux qh, which in thermodynamically saturated pore water, controls the weathering velocity and mineral losses from the profiles. Long-term fluid fluxes required to reproduce the feldspar weathering profiles are in agreement with contemporary values based on solute Cl balances (qh = 0.025-0.17 m yr-1). During saturation-controlled and solute-limited weathering, the greater loss of plagioclase relative to K-feldspar is dependent on the large difference in their respective solubilities instead of the small difference between their respective

Determination of Neutron Flux Parameter f and α and k0 Factor in Irradiation Facility of RSG GA Siwabessy reactor

International Nuclear Information System (INIS)

Amir Hamzah

2004-01-01

Determination of neutron flux thermal to epithermal ratio f and parameter α and k 0 factor has been done in irradiation facility of RSG G.A. Siwabessy reactor. Those parameters are needed to determine the concentration of an element in a sample using k 0 NAA method. Parameters f was measured using foil activation method and α parameter was obtained from power function fitting at epithermal neutron spectrum. Based on the fitting method the a parameter was determined of 0.0267,0.0255 and -0.0346 at system rabbit, IP2 and CIP irradiation position. The k 0 factor is depended on absolute gamma fraction. The neutron flux thermal to epithermal ratio f at all rabbit system is closed to 40. (author)

Determination of activation energies of K2YF5: Tb by the isothermal decay method

International Nuclear Information System (INIS)

Gallegos, A.A.; Azorin, J.; Khaidukov, M.

2007-01-01

Full text: In the search of thermoluminescent materials (TL) for use in personal dosimetry, were studied different materials such as the lithium fluoride doped with magnesium and titanium (LiF: Mg, Ti), the one which had been studied and used as reference material by their good equivalence with the tissue although has poor sensibility, this has generated the necessity to look for materials that show a considerable improvement as for their TL response. In this search the double fluorides as the double lithium potassium fluorides and yttrium doped with praseodymium (LiKYF 5 : Pr) and the double fluoride of potassium and yttrium doped with terbium (K 2 YF 5 : Tb) they show an alternative with many advantages, for their increase of the sensibility to the being doped with those rare earths in different percentages. In this investigation work was determined some dosimetric characteristics like they are the form of TL glow curve to be able to determine the TL property expressed by the kinetic parameters of the TL glow curve: Activation energy E t of the trapper states and the time of permanency in these metastates given by the preexponential factor s of the TL material: double fluoride of potassium and yttrium doped with terbium (K 2 YF 5 : Tb) to 0.8% and 0.99%. Also to this TL material it is characterized studying the TL response in function of the dose and the time of decay of the TL material. To determine the kinetic parameters of the TL glow curve of the TL materials these went one to one irradiated with a beta radiation source of 90 Sr/ 90 Y giving them a dose of 233 mGy for later to be heated in a lineal way during a certain time, with this the trapped electrons were liberated and the energy excess is emitted in light form. The registration of this light is known like it glow curves, those that were obtained with an analyzer TL Harshaw 4000, with interface to CPU for the handling of the data of the curves. The kinetic parameters of TL glow curve were determined for

Application of k0-based NAA for multielement determination in serpentines and associated minerals

International Nuclear Information System (INIS)

Nagendra Kumar, P.V.; S.V. University, Tirupati; Suresh Kumar, N.; King Fahad Specialist Hospital, Dammam; Acharya, R.; Krishna Reddy, L.; Reddy, A.V.R.

2014-01-01

The k 0 -based neutron activation analysis method was applied for multielement determination in black and yellow serpentines along with two associated minerals namely altered and unaltered dolomites and intrusive rock dolerite, obtained from the asbestos mines of Cuddapah basin, Andhra Pradesh, India. Concentrations of 20 elements were determined and they were used to predict the process of formation of fibrous chrysotile asbestos. Majority of elements as well as REEs reveal the contribution of elements from both dolerite and dolomite during the process of contact metamorphism in forming the mineral serpentine. (author)

Micropaleontological and Paleomagnetic Characterization of La Ceiba K/T Boundary Section, Central Mexico

Science.gov (United States)

Martínez-López, M.; Urrutia-Fucugauchi, J.

2007-05-01

We report results of a micropaleontological and magnetostratigraphic study of the La Ceiba section that spans the K/T boundary. La Ceiba is located in central Mexico (20o 19.8' N, 97o 41.0' W) within the Tampico-Mizantla basin. The K/T boundary is marked by a clastic unit of about one-meter thickness intercalated between the carbonate hemipelagic marls of the Cretaceous Mendez Formation and the Paleocene Velasco Formation. The clastic unit can be divided into four sub-units, according to their texture and architectural characteristics following Arenillas et al. (2002). The basal sub-unit is formed by calcareous marls and is rich in shocked quartz and millimeter size spherules with microtektites and bioclasts of shallow water origin. The second sub-unit is formed by medium-grained sandstones, with clasts and quartz fragments, feldspars, metamorphic and calcareous fragments and re-worked benthic and planktic foraminifera. The third sub-unit is composed by a single body of medium- to fine-grained sandstones with tabular geometry. In this sub-unit, cross- and parallel-lamination trough cross-stratification, current ripples and climbing ripples have been observed. The top sub-unit is a tabular body of fine-grained sandstones, showing parallel-lamination and low-angle cross-lamination, with asymmetric ripples and burrow traces to the top. For the paleontologic and paleomagnetic study we collected twenty-five oriented samples across the section. We measured the low-field susceptibility, intensity and direction of the NRM. The vectorial composition and stability of NRM were analyzed by progressive thermal and alternating field demagnetization. Vectorial orthogonal diagrams and vector subtraction and principal component analysis were used to determine the characteristic magnetization and secondary components for each sample. The characteristic NRM negative inclination and southward declination in the K/T clastic sediments indicate a reverse polarity, which is correlated to

Search for B^0 meson decays to \\pi^0 K^0_S K^0_S, \\eta K^0_S K^0_S, and \\eta^{\\prime}K^0_S K^0_S

Energy Technology Data Exchange (ETDEWEB)

Aubert, B.

2009-05-08

We describe searches for B{sup 0} meson decays to the charmless final states {pi}{sup 0}K{sub S}{sup 0}K{sub S}{sup 0}, {eta}K{sub S}{sup 0}K{sub S}{sup 0}, and {eta}{prime}K{sub S}{sup 0}K{sub S}{sup 0}. The data sample corresponds to 467 x 10{sup 6} B{bar B} pairs produced in e{sup +}e{sup -} annihilation and collected with the BABAR detector at the SLAC National Accelerator Laboratory. We find no significant signals and determine the 90% confidence level upper limits on the branching fractions, in units of 10{sup -7}, {Beta}(B{sup 0} {yields} {pi}{sup 0}K{sub S}{sup 0}K{sub S}{sup 0}) < 12, {Beta}(B{sup 0} {yields} {eta}K{sub S}{sup 0}K{sub S}{sup 0}) < 10, and {Beta}(B{sup 0} {yields} {eta}{prime}K{sub S}{sup 0}K{sub S}{sup 0}) < 20.

The high-pressure structural configurations of Ca_0.2Sr_0.8Al₂Si ₂O₈ feldspar

DEFF Research Database (Denmark)

Benna, Piera; Nestola, Fabrizio; Boffa Ballaran, Tiziana

2007-01-01

Single-crystal in situ high-P X-ray diffraction was performed at P = 0.0001, 3.2, 4.4, 6.2, and 7.4 GPa on synthetic Ca0.2Sr0.8Al2Si2O8 feldspar (An20SrF80). Data collections conÞ rmed the displacive Þ rst-order triclinic I1-monoclinic I2/c phase transition at P ~4.3 GPa found in a previous high-...

Determination of integral K-shell Compton scattering cross-sections in elements 41>=Z>=51 for 1250 keV photons

Energy Technology Data Exchange (ETDEWEB)

Verma, S L; Allawadhi, K L; Sood, B S [Punjabi Univ., Patiala (India). Dept. of Physics

1978-04-01

Integral K-shell Compton scattering cross-sections in elements Nb, Mo, Ag, Cd, In, Sn and Sb have been determined for 1250 keV photons. The results when compared with theory suggest that K-shell electrons in the elements under investigation behave as free electrons.

Magma hybridization in the Western Tatra Mts. granitoid intrusion (S-Poland, Western Carpathians).

Science.gov (United States)

Burda, Jolanta; Gawęda, Aleksandra; Klötzli, Urs

In the Variscan Western Tatra granites hybridization phenomena such as mixing and mingling can be observed at the contact of mafic precursors of dioritic composition and more felsic granitic host rocks. The textural evidence of hybridization include: plagioclase-K-feldspar-sphene ocelli, hornblende- and biotite-rimmed quartz ocelli, plagioclase with Ca-rich spike zonation, inversely zoned K-feldspar crystals, mafic clots, poikilitic plagioclase and quartz crystals, mixed apatite morphologies, zoned K-feldspar phenocrysts. The apparent pressure range of the magma hybridization event was calculated at 6.1 kbar to 4.6 kbar, while the temperature, calculated by independent methods, is in the range of 810°C-770°C. U-Pb age data of the hybrid rocks were obtained by in-situ LA-MC-ICP-MS analysis of zircon. The oscillatory zoned zircon crystals yield a concordia age of 368 ± 8 Ma (MSWD = 1.1), interpreted as the age of magma hybridization and timing of formation of the magmatic precursors. It is the oldest Variscan magmatic event in that part of the Tatra Mountains.

Is there a geochemical link between volcanic and plutonic rocks in the Organ Mountains caldera?

Science.gov (United States)

Memeti, V.; Davidson, J.

2013-12-01

determine within-crystal geochemical variations. Our current conclusions and working hypotheses are: 1) All igneous rocks from the Organ Mountains are crustal-mantle melt mixtures indicating two component mixing; 2) the caldera-forming ignimbrites are likely derived from a fractionating Organ Needle pluton; 3) pre- and post-caldera lavas are isotopically similar to the post-caldera Sugarloaf Peak quartz-monzonite; 4) K-feldspar cumulate textures in the structurally top 0.5-1 km of the Organ Needle pluton indicate that interstitial melt was lost from the magma mush, which likely fed the ignimbrite eruptions. 5) Plutonic feldspar textures are complex compared to rather simple zoned volcanic feldspars including K-feldspar rimmed plagioclase, plagioclase rimmed K-feldspar and unrimmed feldspars occurring over a range of grain sizes at thin section scale. Some volcanic feldspar phenocrysts have any previous zonation erased due to late stage albitization. Although the single mineral studies are still work in progress and details need resolving, our data so far suggest a geochemical link between volcanic and plutonic rocks of the Organ Mountains caldera, albeit a complex one; and greater complexity in plutonic versus volcanic minerals. [1] Seager (1980), NM Bureau of Mines and Min. Res. Memoir 36, 97 p. [2] Zimmerer & McIntosh (2013) Journal of Geophysical Research, v. 93, p. 4421-4433

In-situ 40Ar/39Ar Laser Probe Dating of Micas from Mae Ping Shear Zone, Northern Thailand

Science.gov (United States)

Lin, Y. L.; Yeh, M. W.; Lo, C. H.; Lee, T. Y.; Charusiri, P.

2012-04-01

The Mae Ping Shear Zone (MPSZ, also known as Wang Chao Fault Zone), which trends NW-SE from Myanmar to central Thailand, was considered as the southern boundary of the SE extrusion of Indochina and Sibumasu block during the Cenozoic escape tectonic event of SE asia. Many analyses of 40Ar/39Ar dating on biotite and K-feldspar, K/Ar dating on biotite and illite, zircon fission-track and apatite fission-track dating had been accomplished to constrain the shearing period. Nevertheless, it is hard to convince that the ages could represent the end of the shearing since none of the dated minerals have been proved to be crystallized syn-tectonically. Meta-granitoid and gneiss from the MPSZ were analyzed in this study by applying in-situ 40Ar/39Ar laser probe dating with combination of petrology and micro-structural analysis in the purpose to decipher the geological significance of the dates. Plagioclase was replacing K-feldspar for K-feldspar was cut and embayed by plagioclase observed by SEM + EDS. Muscovite in the granitoid own fish shapes of sinistral sense of shearing, and are always in contact with plagioclase and quartz, which suggests that the muscovite crystallized from the dissolving K-feldspar under amphibolite facies condition. 117 spots on 12 muscovite fishes yield ages from 44 Ma to 35 Ma and have a mean age of 40 Ma. Since the growth condition of the muscovite is higher than the closure temperature, thus we can interpret these muscovite ages as cooling ages. Hence left-lateral shearing of the MPSZ can be deduced as syn- to post-muscovite growth and uplifted the crystalline rocks within the shear zone. The ages of matrix biotite in gneiss has a mean age of 35 Ma, which is consistent with the cooling path reconstructed from previous studies. While the ages of inclusion biotite in the K-feldspar phenocryst scatter from 40 to 50 Ma due to the isotopes were not totally re-equilibrated during the shearing. Consequently, the left-lateral shearing of the MPSZ was

Determination of Mg, Al, Si, Cl and K in some medicinal plants by NAA and REA methods

Energy Technology Data Exchange (ETDEWEB)

Mumba, N.K.; Csikai, J.; Petoe, G. (Kossuth Lajos Tudomanyegyetem, Debrecen (Hungary). Kiserleti Fizikai Intezet)

1982-07-26

Trace elements have been determined in biological samples including pepperwort, thyme, plantain, blessed thistle and common comfrey as well as cabbage leaves and milk powder. Concentrations of Al, Si, and Cl have been determined by fast neutron activation analysis while, in the case of Mg-, K, and Cl the X-ray fluorescence method was used.

K$_{-}$ and K$_{-}$ polarizability from kaonic atoms

CERN Document Server

Backenstoss, Gerhard; Bergström, I; Bunaciu, T; Egger, J; Hagelberg, R; Hultberg, S; Koch, H; Lynen, Y; Ritter, H G; Schwitter, A; Tauscher, L

1973-01-01

The K/sup -/ mass was determined from kaonic atomic X-rays from Au and Ba to be 493.691+or-0.040 MeV. An upper limit for the polarizability of the K/sup -/ was found to be 0.020 fm/sup 3/ at 90% confidence. (18 refs).

Determination of Mg, Al, Si, Cl and K in some medicinal plants by NAA and REA methods

International Nuclear Information System (INIS)

Mumba, N.K.; Csikai, J.; Petoe, G.

1982-01-01

Trace elements have been determined in biological samples including pepperwort, thyme, plantain, blessed thistle and common comfrey as well as cabbage leaves and milk powder. Concentrations of Al, Si, and Cl have been determined by fast neutron activation analysis while, in the case of Mo-, K, and Cl the X-ray fluorescence method was used. (author)

Trace and essential elements determination in baby formulas milk by INAA and k0-INAA techniques

International Nuclear Information System (INIS)

Lylia Hamidatou; Hocine Slamene; Tarik Akhal; Alaa Boulegane

2014-01-01

As a part of the food analysis program executed at Es-Salam research reactor by neutron activation analysis laboratory, the concentration of As, Ba, Br, Ca, Fe, K, La, Rb and Zn in baby formulas milk have been determined by using INAA and k 0 -NAA techniques. It was found that the concentration of all elements obtained by both techniques was relatively identical for the three brands of the 0-6 and 6-12 months of analyzed samples. In addition, the analytical results have been compared with those given by producers. (author)

Determination of potassium in several plants and study of potassium transfer to different beverages, including tequila, by measurement of 40K

International Nuclear Information System (INIS)

Navarrete, J.M.; Muller, G.; Cabrera, L.; Martinez, T.

2006-01-01

Measurement of 40 K was used for determination of potassium concentrations in leaves of agave and maguey cactus leaves, and coffee beans of various origins. The procedure was also used to study potassium transfer to tequila (alcoholic drink made of agave cactus), and the cactus and coffee infusions using 40 K as a natural radioactive tracer. Counting of 40 K in Marinelli containers with the aid of a low background NaI(Tl) scintillation detection system for 12-24 hours was employed. The method appeared to be simple and suitable for determination of potassium concentrations in large samples, which eliminates homogeneity problems. (author)

Determination of K-factors for arbitrarily shaped flaws at pressure vessel nozzle corners

International Nuclear Information System (INIS)

Bryson, J.W.

1979-01-01

Photoelastic and finite element studies are being conducted to determine Mode I stress intensity factor distributions along arbitrarily shaped flaw fronts at pressure vessel nozzle corners. Comparisons of results from NOZ-FLAW, BIGIF, and the photoelastic studies showed that (1) good agreement was obtained between NOZ-FLAW and the photoelastically determined K 1 's for the deep flaw in an ITV model, (2) good agreement was obtained between NOZ-FLAW BIGIF for shallow and moderately deep flaws in a BWR model, and (3) less satisfactory agreement was obtained between NOZ- FLAW and the photoelastic results for the BWR models, particularly for moderately deep to deep flaws. Attempts are presently being made at understanding and explaining the discrepancies between the two

Determination of trace amounts of selenium in minerals and rocks by flame less atomic-absorption spectrometry

International Nuclear Information System (INIS)

Alduan, F. A.; Capdevilla, C.

1980-01-01

The determination of trace amounts of selenium In silicate rocks and feldspar by solvent extraction and graphite furnace atomic-absorption spectrometry has been stu- died. Sodium diethyl-ditio carbamate and ammonium pyrrolidine dithiocarbamate have been tried as chelating agents. The best results are achieved when selenium is extracted Into carbon tetrachloride as the sodium diethyldithiocarbamate complex. The method allows to detect 0,75 ppm of selenium in the sample. Recoveries are about 100%. (Author) 7 refs

Theoretical and experimental determination of K - and L -shell x-ray relaxation parameters in Ni

Science.gov (United States)

Guerra, M.; Sampaio, J. M.; Parente, F.; Indelicato, P.; Hönicke, P.; Müller, M.; Beckhoff, B.; Marques, J. P.; Santos, J. P.

2018-04-01

Fluorescence yields (FY) for the Ni K and L shells were determined by a theoretical and an experimental group within the framework of the International Initiative on X-ray Fundamental Parameters (FPs) collaboration. Coster-Kronig (CK) parameters were also measured for the L shell of Ni. Theoretical calculations of the same parameters were performed using the Dirac-Fock method, including relativistic and QED corrections. The experimental values for the FY and CK were determined at the PTB laboratory in the synchrotron radiation facility BESSY II, Berlin, Germany, and are compared to the corresponding calculated values.

Search for the suppressed decays $B^{+}\\rightarrow K^{+}K^{+}\\pi^{-}$ and $B^{+}\\rightarrow \\pi^{+}\\pi^{+}K^{-}$

CERN Document Server

Aaij, Roel; Adinolfi, Marco; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Andreassi, Guido; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; d'Argent, Philippe; Arnau Romeu, Joan; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Babuschkin, Igor; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Batsukh, Baasansuren; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Bel, Lennaert; Bellee, Violaine; Belloli, Nicoletta; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bertolin, Alessandro; Betti, Federico; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bezshyiko, Iaroslava; Bifani, Simone; Billoir, Pierre; Bird, Thomas; Birnkraut, Alex; Bitadze, Alexander; Bizzeti, Andrea; Blake, Thomas; Blanc, Frederic; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Boettcher, Thomas; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borgheresi, Alessio; Borghi, Silvia; Borisyak, Maxim; Borsato, Martino; Bossu, Francesco; Boubdir, Meriem; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Braun, Svende; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Buchanan, Emma; Burr, Christopher; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Camboni, Alessandro; Campana, Pierluigi; Campora Perez, Daniel; Campora Perez, Daniel Hugo; Capriotti, Lorenzo; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carniti, Paolo; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cavallero, Giovanni; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chatzikonstantinidis, Georgios; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chobanova, Veronika; Chrzaszcz, Marcin; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Costa Sobral, Cayo Mar; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dall'Occo, Elena; Dalseno, Jeremy; David, Pieter; Davis, Adam; De Aguiar Francisco, Oscar; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Serio, Marilisa; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Demmer, Moritz; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Dey, Biplab; Di Canto, Angelo; Dijkstra, Hans; Dordei, Francesca; Dorigo, Mirco; Dosil Su{á}rez, Alvaro; Dovbnya, Anatoliy; Dreimanis, Karlis; Dufour, Laurent; Dujany, Giulio; Dungs, Kevin; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; D{é}l{é}age, Nicolas; Easo, Sajan; Ebert, Marcus; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Farley, Nathanael; Farry, Stephen; Fay, Robert; Fazzini, Davide; Ferguson, Dianne; Fernandez Albor, Victor; Fernandez Prieto, Antonio; Ferrari, Fabio; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fini, Rosa Anna; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fleuret, Frederic; Fohl, Klaus; Fontana, Marianna; Fontanelli, Flavio; Forshaw, Dean Charles; Forty, Roger; Franco Lima, Vinicius; Frank, Markus; Frei, Christoph; Fu, Jinlin; Furfaro, Emiliano; F{ä}rber, Christian; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; Garcia Martin, Luis Miguel; Garc{í}a Pardi{ñ}as, Juli{á}n; Garra Tico, Jordi; Garrido, Lluis; Garsed, Philip John; Gascon, David; Gaspar, Clara; Gavardi, Laura; Gazzoni, Giulio; Gerick, David; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gian{ì}, Sebastiana; Gibson, Valerie; Girard, Olivier G{ö}ran; Giubega, Lavinia-Helena; Gizdov, Konstantin; Gligorov, V.V.; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gorelov, Igor Vladimirovich; Gotti, Claudio; Grabalosa G{á}ndara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Griffith, Peter; Grillo, Lucia; Gruberg Cazon, Barak Raimond; Gr{ü}nberg, Oliver; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; G{ö}bel, Carla; Hadavizadeh, Thomas; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; Hatch, Mark; He, Jibo; Head, Timothy; Heister, Arno; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adl{è}ne; Hill, Donal; Hombach, Christoph; Hulsbergen, Wouter; Humair, Thibaud; Hushchyn, Mikhail; Hussain, Nazim; Hutchcroft, David; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jawahery, Abolhassan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Kariuki, James Mwangi; Karodia, Sarah; Kecke, Matthieu; Kelsey, Matthew; Kenyon, Ian; Kenzie, Matthew; Ketel, Tjeerd; Khairullin, Egor; Khanji, Basem; Khurewathanakul, Chitsanu; Kirn, Thomas; Klaver, Suzanne; Klimaszewski, Konrad; Koliiev, Serhii; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Kozachuk, Anastasiia; Kozeiha, Mohamad; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krokovny, Pavel; Kruse, Florian; Krzemien, Wojciech; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kuonen, Axel Kevin; Kurek, Krzysztof; Kvaratskheliya, Tengiz; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Leflat, Alexander; Lefran{ç}ois, Jacques; Lef{è}vre, Regis; Lemaitre, Florian; Lemos Cid, Edgar; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Liu, Xuesong; Loh, David; Longstaff, Iain; Lopes, Jose; Lucchesi, Donatella; Lucio Martinez, Miriam; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Lusiani, Alberto; Lyu, Xiao-Rui; Machefert, Frederic; Maciuc, Florin; Maev, Oleg; Maguire, Kevin; Malde, Sneha; Malinin, Alexander; Maltsev, Timofei; Manca, Giulia; Mancinelli, Giampiero; Manning, Peter Michael; Maratas, Jan; Marchand, Jean Fran{ç}ois; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Marks, J{ö}rg; Martellotti, Giuseppe; Martin, Morgan; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massacrier, Laure Marie; Massafferri, Andr{é}; Matev, Rosen; Mathad, Abhijit; Mathe, Zoltan; Matteuzzi, Clara; Mauri, Andrea; Maurin, Brice; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; Meadows, Brian; Meier, Frank; Meissner, Marco; Melnychuk, Dmytro; Merk, Marcel; Merli, Andrea; Michielin, Emanuele; Milanes, Diego Alejandro; Minard, Marie-Noelle; Mitzel, Dominik Stefan; Mogini, Andrea; Molina Rodriguez, Josue; Monroy, Ignacio Alberto; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mord{à}, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Mulder, Mick; Mussini, Manuel; M{ü}ller, Dominik; M{ü}ller, Janine; M{ü}ller, Katharina; M{ü}ller, Vanessa; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nandi, Anita; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen-Mau, Chung; Nieswand, Simon; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Ogilvy, Stephen; Oldeman, Rudolf; Onderwater, Gerco; Otalora Goicochea, Juan Martin; Otto, Adam; Owen, Patrick; Oyanguren, Maria Aranzazu; Pais, Preema Rennee; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Pappenheimer, Cheryl; Parker, William; Parkes, Christopher; Passaleva, Giovanni; Pastore, Alessandra; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Pescatore, Luca; Petridis, Konstantinos; Petrolini, Alessandro; Petrov, Aleksandr; Petruzzo, Marco; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pikies, Malgorzata; Pinci, Davide; Pistone, Alessandro; Piucci, Alessio; Playfer, Stephen; Plo Casasus, Maximo; Poikela, Tuomas; Polci, Francesco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Pomery, Gabriela Johanna; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, C{é}dric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Quagliani, Renato; Rachwal, Bartolomiej; Rademacker, Jonas; Rama, Matteo; Ramos Pernas, Miguel; Rangel, Murilo; Raniuk, Iurii; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; dos Reis, Alberto; Remon Alepuz, Clara; Renaudin, Victor; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vicente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Lopez, Jairo Alexis; Rodriguez Perez, Pablo; Rogozhnikov, Alexey; Roiser, Stefan; Romanovskiy, Vladimir; Romero Vidal, Antonio; Ronayne, John William; Rotondo, Marcello; Rudolph, Matthew Scott; Ruf, Thomas; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sadykhov, Elnur; Sagidova, Naylya; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santimaria, Marco; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schael, Stefan; Schellenberg, Margarete; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmelzer, Timon; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schubert, Konstantin; Schubiger, Maxime; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sergi, Antonino; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Siddi, Benedetto Gianluca; Silva Coutinho, Rafael; Silva de Oliveira, Luiz Gustavo; Simi, Gabriele; Simone, Saverio; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Eluned; Smith, Iwan Thomas; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Stefko, Pavol; Stefkova, Slavorima; Steinkamp, Olaf; Stemmle, Simon; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Syropoulos, Vasileios; Szczekowski, Marek; Szumlak, Tomasz; T'Jampens, Stephane; Tayduganov, Andrey; Tekampe, Tobias; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Toriello, Francis; Tournefier, Edwige; Tourneur, Stephane; Trabelsi, Karim; Traill, Murdo; Tran, Minh T{â}m; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tully, Alison; Tuning, Niels; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valat, Sebastien; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vecchi, Stefania; van Veghel, Maarten; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Venkateswaran, Aravindhan; Vernet, Maxime; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Volkov, Vladimir; Vollhardt, Achim; Voneki, Balazs; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; V{á}zquez Sierra, Carlos; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wang, Jianchun; Ward, David; Wark, Heather Mckenzie; Watson, Nigel; Websdale, David; Weiden, Andreas; Whitehead, Mark; Wicht, Jean; Wilkinson, Guy; Wilkinson, Michael; Williams, Mark Richard James; Williams, Matthew; Williams, Mike; Williams, Timothy; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wraight, Kenneth; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yin, Hang; Yu, Jiesheng; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zarebski, Kristian Alexander; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Yanxi; Zhang, Yu; Zhelezov, Alexey; Zheng, Yangheng; Zhokhov, Anatoly; Zhu, Xianglei; Zhukov, Valery; Zucchelli, Stefano

2017-02-10

A search is made for the highly-suppressed B meson decays $B^{+}\\rightarrow K^{+}K^{+}\\pi^{-}$ and $B^{+}\\rightarrow \\pi^{+}\\pi^{+}K^{-}$ using a data sample corresponding to an integrated luminosity of 3.0 $fb^{-1}$ collected by the LHCb experiment in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV. No evidence is found for the decays, and upper limits at 90\\% confidence level are determined to be $\\mathcal{B}(B^{+}\\rightarrow K^{+}K^{+}\\pi^{-}) < 1.1\\times 10^{-8}$ and $\\mathcal{B}(B^{+}\\rightarrow \\pi^{+}\\pi^{+}K^{-}) < 4.6\\times 10^{-8}$.

CCQM K6.2 determination of total cholesterol in human serum

Science.gov (United States)

Wise, Stephen A.; Phinney, Karen W.; Duewer, David L.; Sniegoski, Lorna T.; Welch, Michael J.; Pabello, Guiomar; Avila Caldero, Marco A.; Qinde, Liu; Kooi, Lee Tong; Rego, Eliane; Garrido, Bruno; Allegri, Gabriella; de La Cruz, Marcia; Barrabin, Juliana; Puglisi, Celia; Lopez, Eduardo; Lee, Hwashim; Kim, Byungjoo; Delatour, Vincent; Heuillet, Maud; Nammoonnoy, Jintana; Ceyhan Gören, Ahmet; Bilsel, Gokhan; Konopelko, L.; Krylov, A.; Lopushanskaya, E.

2018-01-01

Cholesterol is one of the most frequently measured substances in human blood/serum to assist in assessing the health status of individuals. Because of its clinical significance, CCQM-K6 determination of cholesterol in serum was completed in 2000 as one of the first key comparison (KC) studies performed within the Organic Analysis Working Group (OAWG). The first subsequent KC for cholesterol, CCQM-K6.1, was completed in 2001. Measurements for this second subsequent, CCQM-K6.2, were completed in 2012. These subsequent comparisons were conducted to enable CCQM members that had not participated in earlier studies to demonstrate their capabilities to measure a nonpolar (pKow mass (100 g/mol to 500 g/mol) metabolite in human serum at relatively high concentrations (1 mg/g to 3 mg/g) found in normal populations. Successful participation in CCQM-K6.2 demonstrated capabilities in analysis of complex biological matrices including sample preparation (extraction, derivatization), LC or GC separation, and quantification using an isotope dilution mass spectrometry approach. Normally in a subsequent KC, no key comparison reference value (KCRV) would be established and assessment of performance would be via the deviation of participants' results to the anchor institute's results, adjusted to account for the anchor's performance in the original comparison versus its KCRV. Due to the very long-time period since the original key comparison, the OAWG decided that this did not represent the best approach to assess performance in what is a relatively complex measurement. Given the excellent agreement between the anchor institute's results and robust consensus summary of the participants' values, the reference value for this study was taken as the anchor institute's result and treated as a 'KCRV'. Seven of the nine participants demonstrated agreement with the reference value. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears

Determination of 228Th, 226Ra and 40K in Soil Using In-Situ GammaSpectrometer

International Nuclear Information System (INIS)

Bunawas; Wahyudi; Syarbaini; Untara

2000-01-01

Determination of natural radionuclide in latosol soil at six locationsaround PPTN Serpong by using Inspector portable gamma spectrometer with highpurity Germanium detector (HPGe) which has 26% relative efficiency had beenobtained. Radionuclides data of 228 Th, 226 Ra and 40 K were obtained in4 hours, shorter than laboratories analysis which needed 3 weeks. Thedifferences between in-situ measurement and laboratory were 3.6% to 56.2% forsix conditions of soil measured. According to the specific activity dataanalysis using statistic hypothesis, the result shows that the activity of 228 Th and 226 Ra are independent on location, but 40 K is dependent onlocation. (author)

Adsorption of N-tallow 1,3-propanediamine-dioleate collector on albite and quartz minerals, and selective flotation of albite from greek stefania feldspar ore.

Science.gov (United States)

Vidyadhar, A; Hanumantha Rao, K; Forssberg, K S E

2002-04-01

The adsorption behavior of tallow 1,3-propanediamine-dioleate (Duomeen TDO) collector on albite and quartz minerals is assessed through Hallimond flotation, zeta potential, and diffuse reflectance FTIR investigations, together with the species distribution of the collector. The collector performance on albite separation from a natural feldspar material is evaluated in bench scale flotation tests. The Hallimond flotation responses of the minerals as a function of pH and collector concentration indicate that albite can be selectively floated from quartz at pH 2 where the doubly positively charged collector species adsorb on albite but not on quartz. However, the zeta potential and infrared spectra reveal that the adsorption behavior of the collector is similar on both minerals. The discrepancy in the flotation and adsorption results is attributed to the coarse and fine particle size fractions, and the shorter and longer equilibration periods employed in these studies respectively. The comparable adsorption on fine particles of albite and quartz at pH 2 is explained by the interaction of ammonium ions on silanol groups by hydrogen bonding as well as electrostatic interactions. The changes in zeta potentials are in good agreement with the formation of ionic species and free molecular forms of the collector. The IR spectra show the coexistence of neutral oleic acid together with charged amine species at low pH values in accordance with the species distribution diagram. Selective flotation of albite is accomplished from a natural feldspar material with tallow diamine-dioleate collector at pH 2 using sulfuric acid, only when the feed is deslimed prior to the bench scale flotation tests. An albite recovery exceeding 85% is achieved from a feed material containing about 50% albite.

Electromagnetic mass splittings of π, a1, K, K1(1400), and K* (892)

International Nuclear Information System (INIS)

Gao, D.; Li, B.A.; Yan, M.

1997-01-01

To one-loop order and O(α EM ), the electromagnetic mass splittings of π, a 1 , K, K 1 (1400), and K * (892) are calculated in the framework of U(3) L xU(3) R chiral field theory. The logarithmic divergences emerging in the Feynman integrations of the mesonic loops are factorized by using an intrinsic parameter g of this theory. No other additional parameters or counterterms are introduced to absorb the mesonic loop divergences. When f π , m ρ , and m a are taken as inputs, the parameter g will be determined and all the physical results are finite and fixed. Dashen's theorem is satisfied in the chiral SU(3) limit of this theory and a rather large violation of the theorem is revealed at the order of m s or m K 2 . Mass ratios of light quarks have been determined. A relation for electromagnetic corrections to masses of axial-vector mesons is obtained. It could be regarded as a generalization of Dashen's theorem. Comparing with data, it is found that the nonelectromagnetic mass difference of K * is in agreement with the estimation of Schechter, Subbaraman, and Weigel. copyright 1997 The American Physical Society

A study of K*(890) and K*(1420) production mechanisms in K/sup +/p. -->. K/sup +/. pi. /sup -/. delta. /sup + +/ at 13 GeV/c. [Exchange mechanisms, angular distributions

Energy Technology Data Exchange (ETDEWEB)

Estabrooks, P; Martin, A D [Durham Univ. (UK); Brandenburg, G W; Carnegie, R K; Cashmore, R J; Davier, M; Dunwoodie, W M; Lasinski, T A; Leith, D W.G.S.; Matthews, J A.J.

1976-04-05

Amplitudes for K*(890) and K*(1420) production, and their lower spin background, are determined from an analysis of the K..pi.. angular distribution observed in K/sup +/p..-->..K/sup +/..pi../sup -/..delta../sup + +/ at 13 GeV/c. The exchange mechanisms responsible for K*..delta.. production are studied, and a simple model is introduced which describes all features of the data.

Measurements of the absolute branching fractions for D→anti Kπe+νe, D→anti K*e+νe and determination of Γ(D+→anti K*0e+νe)/Γ(D+→anti K0e+νe)

International Nuclear Information System (INIS)

Ablikim, M.; Bai, J.Z.; Ban, Y.

2006-01-01

Using the data of about 33 pb -1 collected at and around 3.773 GeV with the BES-II detector at the BEPC collider, we have studied the exclusive semileptonic decays D + →K - π + e + ν e , D 0 →anti K 0 π - e + ν e , D + →anti K *0 e + ν e and D 0 →K *- e + ν e . The absolute branching fractions for the decays are measured to be BF(D + →K - π + e + ν e )=(3.50±0.75±0.27)%, BF(D 0 →anti K 0 π - e + ν e )=(2.61±1.04±0.28)%, BF(D + →anti K *0 e + ν e )=(5.06±1.21±0.40)% and BF(D 0 →K *- e + ν e )=(2.87±1.48±0.39)%. The ratio of the vector to pseudoscalar semileptonic decay rates Γ(D + →anti K *0 e + ν e )/Γ(D + →anti K 0 e + ν e ) is determined to be 0.57±0.17±0.02. (orig.)

Final report on CCQM-K27.2: Second Subsequent study: determination of ethanol in aqueous media

Science.gov (United States)

Schantz, Michele M.; Parris, Reenie M.; May, Willie E.; Rosso, Adriana; Puglisi, Celia; Marques Rodrigues Caixeiro, Janaína; Massiff, Gabriela; Camacho Frías, Evangelina; Pérez Urquiza, Melina; Archer, Marcellé; Visser, M. S.; deVos, Betty-Jayne

2013-01-01

Ethanol is important both forensically ('drunk driving' or driving while under the influence, 'DWI', regulations) and commercially (alcoholic beverages). Blood- and breath-alcohol testing can be imposed on individuals operating private vehicles such as cars, boats or snowmobiles, or operators of commercial vehicles like trucks, planes and ships. The various levels of blood alcohol that determine whether these operators are considered legally impaired vary depending on the circumstances and locality. Accurate calibration and validation of instrumentation is critical in areas of forensic testing where quantitative analysis directly affects the outcome of criminal prosecutions, as is the case with the determination of ethanol in blood and breath. Additionally, the accurate assessment of the alcoholic content of beverages is a commercially important commodity. In 2002, the CCQM conducted a key comparison (CCQM-K27) for the determination of ethanol in aqueous matrix with nine participants. A report on this project has been approved by the CCQM and can be found at the BIPM website. CCQM-K27 comprised three samples, one at low mass fraction of ethanol in water (nominal concentration of 0.8 mg/g), one at high level (nominal concentration of 120 mg/g) and one wine matrix (nominal concentration of 81 mg/g). Overall agreement among eight participants using gas chromatography with flame ionization detection (GC-FID), titrimetry, isotope dilution gas chromatography/mass spectrometry (GC-IDMS) and gas chromatography-combustion-isotope ratio mass spectrometry (ID-GC-C-IRMS) was good. The ninth participant used a headspace GC-FID method that had not been validated in an earlier pilot study (CCQM-P35). A follow-on key comparison, CCQM-K27-Subsequent, was initiated in 2003 to accommodate laboratories that had not been ready to benchmark their methods in the original CCQM-K27 study or that wished to benchmark a different method. Four levels of ethanol in water were used in the

Determination of vitamin K homologues by high-performance liquid chromatography with on-line photoreactor and peroxyoxalate chemiluminescence detection

International Nuclear Information System (INIS)

Ahmed, Sameh; Kishikawa, Naoya; Nakashima, Kenichiro; Kuroda, Naotaka

2007-01-01

A sensitive and highly selective high-performance liquid chromatography (HPLC) method was developed for the determination of vitamin K homologues including phylloquinone (PK), menaquinone-4 (MK-4) and menaquinone-7 (MK-7) in human plasma using post-column peroxyoxalate chemiluminescence (PO-CL) detection following on-line ultraviolet (UV) irradiation. The method was based on ultraviolet irradiation (254 nm, 15 W) of vitamin K to produce hydrogen peroxide and a fluorescent product at the same time, which can be determined with PO-CL detection. The separation of vitamin K by HPLC was accomplished isocratically on an ODS column within 35 min. The method involves the use of 2-methyl-3-pentadecyl-1,4-naphthoquinone as an internal standard. The detection limits (signal-to-noise ratio = 3) were 32, 38 and 85 fmol for PK, MK-4 and MK-7, respectively. The recoveries of PK, MK-4 and MK-7 were greater than 82% and the inter- and intra-assay R.S.D. values were 1.9-5.4%. The sensitivity and selectivity of this method were sufficient for clinical and nutritional applications

Constraining the timing of palaeosol development in Iranian arid environments using OSL dating

DEFF Research Database (Denmark)

Rashidi, Zakieh; Sohbati, Reza; Karimi, Alireza

2018-01-01

are compared to investigate the degree of bleaching of quartz OSL in individual samples at the time of deposition. A comparison between the quartz OSL and K-feldspar IR50 ages shows that 12 out of 15 samples were probably well-bleached prior to deposition. The 17 OSL ages constrain at least four broad phases......The ages of palaeosols in arid environments in Iran are constrained using the optically stimulated luminescence (OSL) signal from quartz. The luminescence properties of quartz OSL and K-feldspar infrared stimulated luminescence (IRSL) at 50 °C (IR50) and post-IR IRSL at 290 °C (pIRIR290) signals...

Microstructure Study For Optimization Of Dielectric Property Of Electrical Porcelain

International Nuclear Information System (INIS)

Tak, S. K.; Shekhawat, M. S.; Mangal, R.

2010-01-01

Five sample mixtures of kaolin, ball clay, feldspar and Quartz were formulated and porcelain samples fabricated. Crystalline phases and mullite morphology were studied using XRD and SEM respectively. A composition of 30% kaolin, 15% ball clay, 30% feldspar and 25% quartz yielded a body with high dielectric strength of 19 kV/mm compare to an ISO graded product having dielectric strength 14.6 KV/mm after firing at 1225 deg. C.

Study of K-π- inelastic scattering from K-p interactions at 4.2 GeV/c

International Nuclear Information System (INIS)

Voorthuis, H.; Groot, A.J. de; Jongejans, B.; Kluyver, J.C.; Kittel, E.W.; Schotanus, D.J.

1976-01-01

The isospin I=3/2K - π - inelastic scattering cross section is determined from the reactions K - p→Δ ++ (K+pions) -- at 4.2 GeV/c incident K - momentum, using a Chew-Low extrapolation method. The available statistics also allowed a determination of the cross sections for individual K - π - reactions by this method. The total inelastic K - π - scattering cross section is found to increase almost linearly with K - π - mass from - π - →(Kππ) -- contribute to the inelastic cross section; higher multiplicity K - π - interactions start to play a role above this mass. (Auth.)

k0-INAA as a contributor in nutrition and health. Multielemental determination in Stevia rebaudiana Bertoni, leaves and stevioside product

International Nuclear Information System (INIS)

Bedregal, P.S.; Ubillus, M.S.; Mendoza, P.A.

2018-01-01

Concerned about food safety and considering the advantages that bring the use of the powerful INAA technique based in k 0 method, we have decided to perform a complete multi element determination in the leaves and in the product stevioside, of Stevia rebaudiana Bertoni, which use as a sweetener has increased in the last decade. Using Stevia leaves from different origin, thirty seven elements were determined using k 0 -INAA; copper was quantified using ontoFAAS, while sixteen elements were determined in the stevioside product from different manufacturers. The results indicated that it is necessary to make a strict quality control on the content of elements in leaves, which are used both as a raw material of the stevioside product, as a sweetener. (author)

A Parametric k-Means Algorithm

Science.gov (United States)

Tarpey, Thaddeus

2007-01-01

Summary The k points that optimally represent a distribution (usually in terms of a squared error loss) are called the k principal points. This paper presents a computationally intensive method that automatically determines the principal points of a parametric distribution. Cluster means from the k-means algorithm are nonparametric estimators of principal points. A parametric k-means approach is introduced for estimating principal points by running the k-means algorithm on a very large simulated data set from a distribution whose parameters are estimated using maximum likelihood. Theoretical and simulation results are presented comparing the parametric k-means algorithm to the usual k-means algorithm and an example on determining sizes of gas masks is used to illustrate the parametric k-means algorithm. PMID:17917692

A General Analysis of $\\gamma$ Determinations from $B \\to \\pi K$ Decays

CERN Document Server

Buras, Andrzej J; Buras, Andrzej J.; Fleischer, Robert

1999-01-01

We present a general parametrization of $B^\\pm\\to\\pi^\\pm K, \\pi^0K^\\pm$ and $B_d\\to\\pi^0 K, \\pi^\\mp K^\\pm$ decays, taking into account both electroweak penguin and rescattering effects. This formalism allows -- among other things -- an improved implementation of the strategies that were recently proposed by Neubert and Rosner to probe the CKM angle $\\gamma$ with the help of $B^\\pm\\to\\pi^\\pm K, \\pi^0K^\\pm$ decays. In particular, it allows us to investigate the sensitivity of the extracted value of $\\gamma$ to the basic assumptions of their approach. We find that certain SU(3)-breaking effects may have an important impact and emphasize that additional hadronic uncertainties are due to rescattering processes. The latter can be controlled by using SU(3) flavour symmetry arguments and additional experimental information provided by $B^\\pm\\to K^\\pm K$ modes. We propose a new strategy to probe the angle $\\gamma$ with the help of the neutral decays $B_d\\to\\pi^0 K, \\pi^\\mp K^\\pm$, which is theoretically cleaner than t...

CCQM key comparison CCQM-K75: Determination of toxic metals in algae

Science.gov (United States)

Shakhashiro, A.; Toervenyi, A.; Gaudino, S.; Rosamilia, S.; Belli, M.; Turk, G. C.

2011-01-01

The determination of mass fraction of toxic elements and especially platinum emitted from automobile catalytic converters in the air is a critical factor in assessing air quality and the potential impact of possible pollutants. Air is in fact one of the main pathways for human exposure to toxic elements. Biomonitors, such as lichen and algae, are examples of environmental samples that have been widely used by the scientific community to assess and monitor the level of environmental pollution. For this purpose, the IAEA-450 algae material containing heavy metals and platinum at low level was prepared by IAEA Seibersdorf Laboratories in collaboration with the Italian National Institute for Environmental Protection—ISPRA (former APAT). During the April meeting in 2009 of the Inorganic Analysis Working Group (IAWG) of the CCQM it was agreed to organize a key comparison K75 for Pt and Ni and a parallel pilot study P118 for As, Cd, Cr, Hg, Ni, Pb and Pt using this algae material. The key comparison CCQM-K75 was successfully organized. The participating NMIs demonstrated a high level of measurement capabilities and technical competence in analysing nickel and platinum at a low level of concentration in environmental samples such as algae. The between-laboratories reproducibility standard deviation for nickel and platinum was 1.9% and 3.6% respectively, which reflects an excellent agreement of between-laboratories measurement results. The ratio between the bias and its expanded uncertainty for nickel and platinum was below 2.0 for all reported results except in one case. This study was a practical demonstration of a CCQM comparison to use the 'core-capabilities' utilized by participants as a mean of providing evidence for Calibration and Measurement Capabilities (CMC) claims for Ni and Pt. Based on this CCQM international key comparison, the measurement capability of the NMIs which participated in the CCQM-K75 has been demonstrated directly for determination of Pt and Ni

Structural determinants of PIP(2) regulation of inward rectifier K(ATP) channels.

Science.gov (United States)

Shyng, S L; Cukras, C A; Harwood, J; Nichols, C G

2000-11-01

Phosphatidylinositol 4,5-bisphosphate (PIP(2)) activates K(ATP) and other inward rectifier (Kir) channels. To determine residues important for PIP(2) regulation, we have systematically mutated each positive charge in the COOH terminus of Kir6.2 to alanine. The effects of these mutations on channel function were examined using (86)Rb efflux assays on intact cells and inside-out patch-clamp methods. Both methods identify essentially the same basic residues in two narrow regions (176-222 and 301-314) in the COOH terminus that are important for the maintenance of channel function and interaction with PIP(2). Only one residue (R201A) simultaneously affected ATP and PIP(2) sensitivity, which is consistent with the notion that these ligands, while functionally competitive, are unlikely to bind to identical sites. Strikingly, none of 13 basic residues in the terminal portion (residues 315-390) of the COOH terminus affected channel function when neutralized. The data help to define the structural requirements for PIP(2) sensitivity of K(ATP) channels. Moreover, the regions and residues defined in this study parallel those uncovered in recent studies of PIP(2) sensitivity in other inward rectifier channels, indicating a common structural basis for PIP(2) regulation.

Determination of 40K radioactivity in the soil using energy dispersive X ray fluorescence spectrometer

International Nuclear Information System (INIS)

Lu Weiwei; Song Fuxiang; Zeng Liping; Lu Hongning

2012-01-01

The 40 K radioactive of' the pressed powder sample was determined by Epsilon 5 high-energy polarized energy dispersive X ray fluorescence (EDXRF) spectrometer. The correlation coefficient of the standard curve method was 0.9910, the precision was 2.98% and the relative deviation of the measurement standard samples was up to 6.40%, which showed that the precision and accuracy of the method were also good. Simultaneous measurement of seven soil samples using this method and γ-spectrometer were carried, the results of two analytical methods were compared using a paired t-test by SPSS program, which showed that there was no significant difference in the two sets of data, P>0.05. It indicated that EDXRF could be a potential simple method for analyzing 40 K radioactive in soil samples. (authors)

A Precise determination of B(K) in quenched QCD

CERN Document Server

Dimopoulos, P.; Palombi, F.; Pena, C.; Sint, S.; Vladikas, A.

2006-01-01

The $B_K$ parameter is computed in quenched lattice QCD with Wilson twisted mass fermions. Two variants of tmQCD are used; in both of them the relevant $\\Delta S = 2$ four-fermion operator is renormalised multiplicatively. The renormalisation adopted is non-perturbative, with a Schroedinger functional renormalisation condition. Renormalisation group running is also non-perturbative, up to very high energy scales. In one of the two tmQCD frameworks the computations have been performed at the physical $K$-meson mass, thus eliminating the need of mass extrapolations. Simulations have been performed at several lattice spacings and the continuum limit was reached by combining results from both tmQCD regularisations. Finite volume effects have been partially checked and turned out to be small. Exploratory studies have also been performed with non-degenerate valence flavours. The final result for the RGI bag parameter, with all sources of uncertainty (except quenching) under control, is $\\hat B_K =0.789 \\pm 0.046$.

Microtectonic-assisted P-T determination on low-grade Alpine metamorphic rocks from the "Tisia Mega-Unit" of the Slavonian Mountains in Croatia

Science.gov (United States)

Balen, Dražen; Lihter, Iva; Massonne, Hans-Joachim

2016-04-01

The internal structure of the Tisia (Tisza) Mega-Unit in the Alpine-Carpathian-Dinaridic orogenic system encompasses large Alpine nappe systems brought to its present-day position by complex regional-scale movements. The Slavonian Mountains are part of the Bihor nappe system which is below the Codru and above the Mecsek nappe systems. The low-grade metamorphic schist unit of the Slavonian Mountains includes numerous rocks which were previously related to Precambrian and/or Lower Paleozoic orogeneses. However, recent studies (e.g. Balen, 2014, European Geosciences Union General Assembly, EGU 2014-6122) show that the metapelites of this unit should be attributed to the Alpine orogeny and the poorly known P-T conditions, which they experienced, should be refined. Although metapelites can be sensitive to changes of metamorphic conditions and, therefore, be suitable for the P-T estimation of metamorphic event(s), the extraction of mineral assemblages, being in equilibrium, and associated microtectonic data for particular low-grade metamorphic rocks is not straightforward. On the contrary, due to lack of suitable minerals and complex mictotectonic features, one can be faced with a severe problem concerning (dis)equilibrium. To avoid this, the observation scale in the research was set to the sub-mm level taking into account microtectonic positions of minerals. The investigated samples from the Slavonian Mountains are fine-grained schists consisting of chlorite (15-30 vol. %), white mica (15-25 vol. %), quartz (10-25 vol. %), feldspars (albite 10-15 vol. %; some K-feldspar), biotite (<5 vol. %), opaques (<5 vol. %), and accessory minerals (zircon, monazite, xenotime, apatite, chalcopyrite, pyrite, barite, parisite-(Ce), rutile). The schists show complex microtectonic fabric including well-developed foliations, pervasive folding, crenulation and cleavage. Foliations are defined by the preferred orientation of phyllosilicates and thin quartz and feldspar ribbons. Chlorite

Evaluation of 40K in vegetables collected Malaysia by determination total potassium using neutron activation analysis

International Nuclear Information System (INIS)

Shafaei, M.A.; Saion, E.; Naghavi, K.; Wood, K.; Rezaee, Kh.

2011-01-01

Some vegetables of important nutritive requirements have been collected from Kuala Lumpur region capital of Malaysia. The vegetables were analyzed in order to determine activity concentration level of potassium using neutron activation analysis (NAA). The NAA results obtained showed the activity concentration of 40 K varied from 379 Bq/kg (Egg-plant) to 1585 Bq/kg (Spinach Red). These results are compared to other researches and are clear that the concentrations of K are relatively high in the Malaysia in compared to rather than vegetables of Pakistan and Jamaican. However, they are seen not to pose any serious internal health burden due to ingestion given the realities of vegetables choice by individuals in the study area. (author)

Determining mineralogical variations of aeolian deposits using thermal infrared emissivity and linear deconvolution methods

Science.gov (United States)

Hubbard, Bernard E.; Hooper, Donald M.; Solano, Federico; Mars, John C.

2018-01-01

We apply linear deconvolution methods to derive mineral and glass proportions for eight field sample training sites at seven dune fields: (1) Algodones, California; (2) Big Dune, Nevada; (3) Bruneau, Idaho; (4) Great Kobuk Sand Dunes, Alaska; (5) Great Sand Dunes National Park and Preserve, Colorado; (6) Sunset Crater, Arizona; and (7) White Sands National Monument, New Mexico. These dune fields were chosen because they represent a wide range of mineral grain mixtures and allow us to gauge a better understanding of both compositional and sorting effects within terrestrial and extraterrestrial dune systems. We also use actual ASTER TIR emissivity imagery to map the spatial distribution of these minerals throughout the seven dune fields and evaluate the effects of degraded spectral resolution on the accuracy of mineral abundances retrieved. Our results show that hyperspectral data convolutions of our laboratory emissivity spectra outperformed multispectral data convolutions of the same data with respect to the mineral, glass and lithic abundances derived. Both the number and wavelength position of spectral bands greatly impacts the accuracy of linear deconvolution retrieval of feldspar proportions (e.g. K-feldspar vs. plagioclase) especially, as well as the detection of certain mafic and carbonate minerals. In particular, ASTER mapping results show that several of the dune sites display patterns such that less dense minerals typically have higher abundances near the center of the active and most evolved dunes in the field, while more dense minerals and glasses appear to be more abundant along the margins of the active dune fields.

Determining mineralogical variations of aeolian deposits using thermal infrared emissivity and linear deconvolution methods

Science.gov (United States)

Hubbard, Bernard E.; Hooper, Donald M.; Solano, Federico; Mars, John C.

2018-02-01

We apply linear deconvolution methods to derive mineral and glass proportions for eight field sample training sites at seven dune fields: (1) Algodones, California; (2) Big Dune, Nevada; (3) Bruneau, Idaho; (4) Great Kobuk Sand Dunes, Alaska; (5) Great Sand Dunes National Park and Preserve, Colorado; (6) Sunset Crater, Arizona; and (7) White Sands National Monument, New Mexico. These dune fields were chosen because they represent a wide range of mineral grain mixtures and allow us to gauge a better understanding of both compositional and sorting effects within terrestrial and extraterrestrial dune systems. We also use actual ASTER TIR emissivity imagery to map the spatial distribution of these minerals throughout the seven dune fields and evaluate the effects of degraded spectral resolution on the accuracy of mineral abundances retrieved. Our results show that hyperspectral data convolutions of our laboratory emissivity spectra outperformed multispectral data convolutions of the same data with respect to the mineral, glass and lithic abundances derived. Both the number and wavelength position of spectral bands greatly impacts the accuracy of linear deconvolution retrieval of feldspar proportions (e.g. K-feldspar vs. plagioclase) especially, as well as the detection of certain mafic and carbonate minerals. In particular, ASTER mapping results show that several of the dune sites display patterns such that less dense minerals typically have higher abundances near the center of the active and most evolved dunes in the field, while more dense minerals and glasses appear to be more abundant along the margins of the active dune fields.

Development and validation of a FIA/UV-vis method for pK(a) determination of oxime based acetylcholinesterase reactivators.

Science.gov (United States)

Musil, Karel; Florianova, Veronika; Bucek, Pavel; Dohnal, Vlastimil; Kuca, Kamil; Musilek, Kamil

2016-01-05

Acetylcholinesterase reactivators (oximes) are compounds used for antidotal treatment in case of organophosphorus poisoning. The dissociation constants (pK(a1)) of ten standard or promising acetylcholinesterase reactivators were determined by ultraviolet absorption spectrometry. Two methods of spectra measurement (UV-vis spectrometry, FIA/UV-vis) were applied and compared. The soft and hard models for calculation of pK(a1) values were performed. The pK(a1) values were recommended in the range 7.00-8.35, where at least 10% of oximate anion is available for organophosphate reactivation. All tested oximes were found to have pK(a1) in this range. The FIA/UV-vis method provided rapid sample throughput, low sample consumption, high sensitivity and precision compared to standard UV-vis method. The hard calculation model was proposed as more accurate for pK(a1) calculation. Copyright © 2015 Elsevier B.V. All rights reserved.

Analysis of the differential cross sections for the reaction pp→ppK+K- in view of the K+K- interaction

International Nuclear Information System (INIS)

Silarski, M.

2008-07-01

Measurements of the pp→ppK + K - reaction, performed with the experiment COSY-11 at the Cooler Synchrotron COSY, show a significant difference between the obtained excitation function and theoretical expectations including pp-FSI. The discrepancy may be assigned to the influence of K + K - or K - p interaction. This interaction should manifest itself in the distributions of the differential cross section. This thesis presents an analysis of event distributions as a function of the invariant masses of two particle subsystems. In particular in the analysis two generalizations of the Dalitz plot proposed by Goldhaber and Nyborg are used. The present Investigations are based on the experimental data determined by the COSY-11 collaboration from two measurements at excess energies of Q=10 MeV and 28 MeV. The experimental distributions are compared to results of Monte Carlo simulations generated with various parameters of the K + K - and K - p interaction. The values of the K + K - scattering length, extracted from two data sets for Q=10 MeV and 28 MeV amount to: a K + K - =(11±8)+i(0±6) fm for Q=10 MeV, and a K + K - =(0.2±0.2)+i(0.0±0.5) fm for Q=28 MeV. Due to the low statistics, the extracted values have large uncertainties and are consistent with very low values of the real and imaginary part of the scattering length. (orig.)

Effect of CaCO_3 addition on ash sintering behaviour during K_2CO_3 catalysed steam gasification of a Chinese lignite

International Nuclear Information System (INIS)

Zhang, Jiguang; Li, Jianbo; Mao, Yandong; Bi, Jicheng; Zhu, Mingming; Zhang, Zhezi; Zhang, Li; Zhang, Dongke

2017-01-01

Highlights: • K_2CO_3 decreased ash sintering temperature and enhanced ash melting in gasification. • CaCO_3 addition enhanced ash melting and lowered ash sintering temperatures. • CaCO_3 reacted with SiO_2 to form fluxing phases and amorphous materials. • CaCO_3 addition inhibited the potassium aluminium silicate formation. • CaCO_3 addition preserved the catalytic activity of potassium. - Abstract: The ash sintering behaviour of a Chinese lignite (LLI) with different amounts of CaCO_3 addition during K_2CO_3-catalysed gasification was investigated. 0–10 wt% K_2CO_3 was doped into the lignite for catalytic gasification, and CaCO_3 was added into the K_2CO_3-doped samples, varying in the range of 0–20 wt% relative to the lignite, for understanding its impact on ash sintering and catalytic gasification activity. Ash samples were prepared by completely gasifying the lignite samples with steam in a fixed-bed catalytic gasification system operating at 1073 K and atmospheric pressure. Sintering temperature, mineralogy and morphology of the ash samples thus obtained were determined using a pressure-drop sintering device, XRD and SEM-EDS, respectively. The results showed that the ash sintering temperature decreased as the K_2CO_3 addition increased, indicating that K_2CO_3 as the catalyst for gasification would promote ash sintering. SEM imaging analysis showed that all the ash samples from LLI with K_2CO_3 addition were composed of agglomerated particles with smooth surfaces, indicating the ashes had incurred partial melting. The degree of melting became more apparent as the K_2CO_3 addition ratio increased. These molten phases were identified as K-bearing arcanite and kaliophilite, which contributed to the formation of liquid phases at lower temperatures, resulting in lowered ash sintering temperatures. It was also revealed that the addition of CaCO_3 decreased the sintering temperatures of ash samples, indicating that the ash sintering was further

Effect of infiltrated water on rheology of plagioclase feldspar under lower crustal condition

Science.gov (United States)

Kido, M.; Muto, J.; Koizumi, S.; Nagahama, H.

2016-12-01

Fluids in the deep crust have an important role in deformation of lithosphere and seismicity. In this study, we performed deformation experiments to reveal rheological properties of plagioclase feldspars as a main constituent of crustal materials with infilitrated water. Axial compression tests on synthetic polycrystalline anorthite (An) were performed in a Griggs-type deformation apparatus at temparature of 900 °C, strain rates of roughly about 10-5 s-1 and various confining pressures of 0.8-1.4 GPa. Distilled water was added on samples before tests. Times for infiltration of water into samples were changed to investigate the variation of strength associated with diffusion of water. Strengths of wet An tended to decrease with infiltration time or strain magnitude. If other conditions such as temperature, time and strain being the same, strengths increase with confining pressures. Recovered samples show that deformation was concentrated in the lower part of samples. Differential stresses were significantly lower than predicted values by a previous flow law for wet An obtained by low pressure gas apparatus ( 0.4 GPa, Rybacki et al., 2006). This implies that the effect of water on mechanical behavior in higher pressure might be larger than those predicted by lower pressure experiments. Ideal water concentration and strength profile of internal of samples were estimated by one-dimensional model of grain boundary diffusion. Estimated strength of internal part of samples was significant higher than measured stresses. There is possibility that cataclastic flow partially occurred in samples. In addition, deformation-enhanced fluid flow probably occurred. In conclusion, strength of wet An depends on water infiltration time, strain magnitude and confining pressure. The results suggest that the strength of fluid-rich regions in the lower crust becomes lower than that predicted by previous studies.

Field Exploration and Life Detection Sampling for Planetary Analogue Research (FELDSPAR)

Science.gov (United States)

Gentry, D.; Stockton, A. M.; Amador, E. S.; Cable, M. L.; Cantrell, T.; Chaudry, N.; Cullen, T.; Duca, Z. A.; Jacobsen, M. B.; Kirby, J.; McCaig, H. C.; Murukesan, G.; Rennie, V.; Rader, E.; Schwieterman, E. W.; Stevens, A. H.; Sutton, S. A.; Tan, G.; Yin, C.; Cullen, D.; Geppert, W.

2017-12-01

Extraterrestrial studies are typically conducted on mg samples from cm-scale features, while landing sites are selected based on m to km-scale features. It is therefore critical to understand spatial distribution of organic molecules over scales from cm to the km, particularly in geological features that appear homogenous at m to km scales. This is addressed by FELDSPAR, a NASA-funded project that conducts field operations analogous to Mars sample return in its science, operations, and technology [1]. Here, we present recent findings from a 2016 and a 2017 campaign to multiple Martian analogue sites in Iceland. Icelandic volcanic regions are Mars analogues due to desiccation, low nutrient availability, temperature extremes [2], and are relatively young and isolated from anthropogenic contamination [3]. Operationally, many Icelandic analogue sites are remote enough to require that field expeditions address several sampling constraints that are also faced by robotic exploration [1, 2]. Four field sites were evaluated in this study. The Fimmvörðuháls lava field was formed by a basaltic effusive eruption associated with the 2010 Eyjafjallajökull eruption. Mælifellssandur is a recently deglaciated plain to the north of the Myrdalsjökull glacier. Holuhraun is a basaltic spatter and cinder cone formed by 2014 fissure eruptions just north of the Vatnajökull glacier. Dyngjusandur is a plain kept barren by repeated aeolian mechanical weathering. Samples were collected in nested triangular grids from 10 cm to the 1 km scale. We obtained overhead imagery at 1 m to 200 m elevation to create digital elevation models. In-field reflectance spectroscopy was obtained with an ASD spectrometer and chemical composition was measured by a Bruker handheld XRF. All sites chosen were homogeneous in apparent color, morphology, moisture, grain size, and reflectance spectra at all scales greater than 10 cm. Field lab ATP assays were conducted to monitor microbial habitation, and home

Formation of albitite-hosted uranium within IOCG systems: the Southern Breccia, Great Bear magmatic zone, Northwest Territories, Canada

Science.gov (United States)

Montreuil, Jean-François; Corriveau, Louise; Potter, Eric G.

2015-03-01

Uranium and polymetallic U mineralization hosted within brecciated albitites occurs one kilometer south of the magnetite-rich Au-Co-Bi-Cu NICO deposit in the southern Great Bear magmatic zone (GBMZ), Canada. Concentrations up to 1 wt% U are distributed throughout a 3 by 0.5 km albitization corridor defined as the Southern Breccia zone. Two distinct U mineralization events are observed. Primary uraninite precipitated with or without pyrite-chalcopyrite ± molybdenite within magnetite-ilmenite-biotite-K-feldspar-altered breccias during high-temperature potassic-iron alteration. Subsequently, pitchblende precipitated in earthy hematite-specular hematite-chlorite veins associated with a low-temperature iron-magnesium alteration. The uraninite-bearing mineralization postdates sodic (albite) and more localized high-temperature potassic-iron (biotite-magnetite ± K-feldspar) alteration yet predates potassic (K-feldspar), boron (tourmaline) and potassic-iron-magnesium (hematite ± K-feldspar ± chlorite) alteration. The Southern Breccia zone shares attributes of the Valhalla (Australia) and Lagoa Real (Brazil) albitite-hosted U deposits but contains greater iron oxide contents and lower contents of riebeckite and carbonates. Potassium, Ni, and Th are also enriched whereas Zr and Sr are depleted with respect to the aforementioned albitite-hosted U deposits. Field relationships, geochemical signatures and available U-Pb dates on pre-, syn- and post-mineralization intrusions place the development of the Southern Breccia and the NICO deposit as part of a single iron oxide alkali-altered (IOAA) system. In addition, this case example illustrates that albitite-hosted U deposits can form in albitization zones that predate base and precious metal ore zones in a single IOAA system and become traps for U and multiple metals once the tectonic regime favors fluid mixing and oxidation-reduction reactions.

Improvement of the Ca determination accuracy with k (0)-INAA using an HPGe coaxial detector with extended energy range efficiency calibration

Czech Academy of Sciences Publication Activity Database

Kučera, Jan; Kubešová, Marie; Lebeda, Ondřej

2018-01-01

Roč. 315, č. 3 (2018), s. 671-675 ISSN 0236-5731. [7th International K0-Users Workshop. Montreal, 03.09.2017-08.09.2017] R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk LM2015056 Institutional support: RVO:61389005 Keywords : k(0)-INAA * Ca determination * HPGe detector * High-energy efficiency calibration * Co-56 activity standard Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 1.282, year: 2016

The brittle-viscous-plastic evolution of shear bands in the South Armorican Shear Zone

Science.gov (United States)

Bukovská, Zita; Jeřábek, Petr; Morales, Luiz F. G.; Lexa, Ondrej; Milke, Ralf

2014-05-01

Shear bands are microscale shear zones that obliquely crosscut an existing anisotropy such as a foliation. The resulting S-C fabrics are characterized by angles lower than 45° and the C plane parallel to shear zone boundaries. The S-C fabrics typically occur in granitoids deformed at greenschist facies conditions in the vicinity of major shear zones. Despite their long recognition, mechanical reasons for localization of deformation into shear bands and their evolution is still poorly understood. In this work we focus on microscale characterization of the shear bands in the South Armorican Shear Zone, where the S-C fabrics were first recognized by Berthé et al. (1979). The initiation of shear bands in the right-lateral South Armorican Shear Zone is associated with the occurrence of microcracks crosscutting the recrystallized quartz aggregates that define the S fabric. In more advanced stages of shear band evolution, newly formed dominant K-feldspar, together with plagioclase, muscovite and chlorite occur in the microcracks, and the shear bands start to widen. K-feldspar replaces quartz by progressively bulging into the grain boundaries of recrystallized quartz grains, leading to disintegration of quartz aggregates and formation of fine-grained multiphase matrix mixture. The late stages of shear band development are marked by interconnection of fine-grained white mica into a band that crosscuts the original shear band matrix. In its extremity, the shear band widening may lead to the formation of ultramylonites. With the increasing proportion of shear band matrix from ~1% to ~12%, the angular relationship between S and C fabrics increases from ~30° to ~40°. The matrix phases within shear bands show differences in chemical composition related to distinct evolutionary stages of shear band formation. The chemical evolution is well documented in K-feldspar, where the albite component is highest in porphyroclasts within S fabric, lower in the newly formed grains within

Signed star (k,k-domatic number of a graph

Directory of Open Access Journals (Sweden)

S. M. Sheikholeslami

2014-01-01

Full Text Available Let \\(G\\ be a simple graph without isolated vertices with vertex set \\(V(G\\ and edge set \\(E(G\\ and let \\(k\\ be a positive integer. A function \\(f:E(G\\longrightarrow \\{-1, 1\\}\\ is said to be a signed star \\(k\\-dominating function on \\(G\\ if \\(\\sum_{e\\in E(v}f(e\\ge k\\ for every vertex \\(v\\ of \\(G\\, where \\(E(v=\\{uv\\in E(G\\mid u\\in N(v\\}\\. A set \\(\\{f_1,f_2,\\ldots,f_d\\}\\ of signed star \\(k\\-dominating functions on \\(G\\ with the property that \\(\\sum_{i=1}^df_i(e\\le k\\ for each \\(e\\in E(G\\, is called a signed star \\((k,k\\-dominating family (of functions on \\(G\\. The maximum number of functions in a signed star \\((k,k\\-dominating family on \\(G\\ is the signed star \\((k,k\\-domatic number of \\(G\\, denoted by \\(d^{(k,k}_{SS}(G\\. In this paper we study properties of the signed star \\((k,k\\-domatic number \\(d_{SS}^{(k,k}(G\\. In particular, we present bounds on \\(d_{SS}^{(k,k}(G\\, and we determine the signed \\((k,k\\-domatic number of some regular graphs. Some of our results extend these given by Atapour, Sheikholeslami, Ghameslou and Volkmann [Signed star domatic number of a graph, Discrete Appl. Math. 158 (2010, 213-218] for the signed star domatic number.

Females and STEM: Determining the K-12 Experiences that Influenced Women to Pursue STEM Fields

Science.gov (United States)

Petersen, Anne Marie

In the United States, careers in the fields of Science, Technology, Engineering, and Mathematics (STEM) are increasing yet there are not enough trained personnel to meet this demand. In addition, of those that seek to pursue STEM fields in the United States, only 26% are female. In order to increase the number of women seeking STEM based bachelor's degrees, K-12 education must provide a foundation that prepares students for entry into these fields. The purpose of this phenomenological study was to determine the perceived K-12 experiences that influenced females to pursue a STEM field. Twelve college juniors or seniors seeking a degree in Biology, Mathematics, or Physics were interviewed concerning their K-12 experiences. These interviews were analyzed and six themes emerged. Teacher passion and classroom characteristics such as incorporating challenging activities played a significant role in the females' decisions to enter STEM fields. Extra-curricular activities such as volunteer and mentor opportunities and the females' need to benefit others also influenced females in their career choice. Both the formal (within the school) and informal (outside of the traditional classroom) pipeline opportunities that these students encountered helped develop a sense of self-efficacy in science and mathematics; this self-efficacy enabled them to persist in pursuing these career fields. Several participants cited barriers that they encountered in K-12 education, but these barriers were primarily internal as they struggled with overcoming self-imposed obstacles in learning and being competitive in the mathematics and science classrooms. The experiences from these female students can be used by K-12 educators to prepare and encourage current female students to enter STEM occupations.

Measurement of the effective $B^0_s \\rightarrow K^+K^-$ lifetime

CERN Document Server

Aaij, R; Adeva, B; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amhis, Y; Anderson, J; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Arrabito, L; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Bachmann, S; Back, J J; Bailey, D S; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bates, A; Bauer, C; Bauer, Th; Bay, A; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Benayoun, M; Bencivenni, G; Benson, S; Benton, J; Bernet, R; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blanks, C; Blouw, J; Blusk, S; Bobrov, A; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Brisbane, S; Britsch, M; Britton, T; Brook, N H; Brown, H; Büchler-Germann, A; Burducea, I; Bursche, A; Buytaert, J; Cadeddu, S; Caicedo Carvajal, J M; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carson, L; Carvalho Akiba, K; Casse, G; Cattaneo, M; Charles, M; Charpentier, Ph; Chiapolini, N; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Collins, P; Comerma-Montells, A; Constantin, F; Conti, G; Contu, A; Cook, A; Coombes, M; Corti, G; Cowan, G A; Currie, R; D'Almagne, B; D'Ambrosio, C; David, P; De Bonis, I; De Capua, S; De Cian, M; De Lorenzi, F; De Miranda, J M; De Paula, L; De Simone, P; Decamp, D; Deckenhoff, M; Degaudenzi, H; Deissenroth, M; Del Buono, L; Deplano, C; Derkach, D; Deschamps, O; Dettori, F; Dickens, J; Dijkstra, H; Diniz Batista, P; Domingo Bonal, F; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Dzhelyadin, R; Dziurda, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisele, F; Eisenhardt, S; Ekelhof, R; Eklund, L; Elsasser, Ch; d'Enterria, D G; Esperante Pereira, D; Estève, L; Falabella, A; Fanchini, E; Färber, C; Fardell, G; Farinelli, C; Farry, S; Fave, V; Fernandez Albor, V; Ferro-Luzzi, M; Filippov, S; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Frank, M; Frei, C; Frosini, M; Furcas, S; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garnier, J-C; Garofoli, J; Garra Tico, J; Garrido, L; Gascon, D; Gaspar, C; Gauvin, N; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Haefeli, G; Haen, C; Haines, S C; Hampson, T; Hansmann-Menzemer, S; Harji, R; Harnew, N; Harrison, J; Harrison, P F; He, J; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicks, E; Holubyev, K; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Huston, R S; Hutchcroft, D; Hynds, D; Iakovenko, V; Ilten, P; Imong, J; Jacobsson, R; Jaeger, A; Jahjah Hussein, M; Jans, E; Jansen, F; Jaton, P; Jean-Marie, B; Jing, F; John, M; Johnson, D; Jones, C R; Jost, B; Kaballo, M; Kandybei, S; Karacson, M; Karbach, T M; Keaveney, J; Kerzel, U; Ketel, T; Keune, A; Khanji, B; Kim, Y M; Knecht, M; Koblitz, S; Koppenburg, P; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kruzelecki, K; Kucharczyk, M; Kumar, R; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Le Gac, R; van Leerdam, J; Lees, J-P; Lefévre, R; Leflat, A; Lefrançois, J; Leroy, O; Lesiak, T; Li, L; Li Gioi, L; Lieng, M; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; Lopes, J H; Lopez Asamar, E; Lopez-March, N; Luisier, J; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Magnin, J; Malde, S; Mamunur, R M D; Manca, G; Mancinelli, G; Mangiafave, N; Marconi, U; Märki, R; Marks, J; Martellotti, G; Martens, A; Martin, L; Martin Sánchez, A; Martinez Santos, D; Massafferri, A; Mathe, Z; Matteuzzi, C; Matveev, M; Maurice, E; Maynard, B; Mazurov, A; McGregor, G; McNulty, R; Mclean, C; Meissner, M; Merk, M; Merkel, J; Messi, R; Miglioranzi, S; Milanes, D A; Minard, M-N; Monteil, S; Moran, D; Morawski, P; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Musy, M; Mylroie-Smith, J; Naik, P; Nakada, T; Nandakumar, R; Nardulli, J; Nasteva, I; Nedos, M; Needham, M; Neufeld, N; Nguyen-Mau, C; Nicol, M; Nies, S; Niess, V; Nikitin, N; Nomerotski, A; Novoselov, A; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Owen, P; Pal, K; Palacios, J; Palano, A; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Paterson, S K; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perego, D L; Perez Trigo, E; Pérez-Calero Yzquierdo, A; Perret, P; Perrin-Terrin, M; Pessina, G; Petrella, A; Petrolini, A; Picatoste Olloqui, E; Pie Valls, B; Pietrzyk, B; Pilar, T; Pinci, D; Plackett, R; Playfer, S; Plo Casasus, M; Polok, G; Poluektov, A; Polycarpo, E; Popov, D; Popovici, B; Potterat, C; Powell, A; du Pree, T; Prisciandaro, J; Pugatch, V; Puig Navarro, A; Qian, W; Rademacker, J H; Rakotomiaramanana, B; Rangel, M S; Raniuk, I; Raven, G; Redford, S; Reid, M M; dos Reis, A C; Ricciardi, S; Rinnert, K; Roa Romero, D A; Robbe, P; Rodrigues, E; Rodrigues, F; Rodriguez Perez, P; Rogers, G J; Roiser, S; Romanovsky, V; Rosello, M; Rouvinet, J; Ruf, T; Ruiz, H; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salzmann, C; Sannino, M; Santacesaria, R; Santamarina Rios, C; Santinelli, R; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schaack, P; Schiller, M; Schleich, S; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M-H; Schwemmer, R; Sciascia, B; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Sepp, I; Serra, N; Serrano, J; Seyfert, P; Shao, B; Shapkin, M; Shapoval, I; Shatalov, P; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Skottowe, H P; Skwarnicki, T; Smith, A C; Smith, N A; Smith, E; Sobczak, K; Soler, F J P; Solomin, A; Soomro, F; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stoica, S; Stone, S; Storaci, B; Straticiuc, M; Straumann, U; Styles, N; Subbiah, V K; Swientek, S; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Topp-Joergensen, S; Torr, N; Tournefier, E; Tran, M T; Tsaregorodtsev, A; Tuning, N; Ubeda Garcia, M; Ukleja, A; Urquijo, P; Uwer, U; Vagnoni, V; Valenti, G; Vazquez Gomez, R; Vazquez Regueiro, P; Vecchi, S; Velthuis, J J; Veltri, M; Vervink, K; Viaud, B; Videau, I; Vilasis-Cardona, X; Visniakov, J; Vollhardt, A; Voong, D; Vorobyev, A; Voss, H; Wacker, K; Wandernoth, S; Wang, J; Ward, D R; Webber, A D; Websdale, D; Whitehead, M; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wishahi, J; Witek, M; Witzeling, W; Wotton, S A; Wyllie, K; Xie, Y; Xing, F; Xing, Z; Yang, Z; Young, R; Yushchenko, O; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhong, L; Zverev, E; Zvyagin, A

2012-01-01

A measurement of the effective $B^0_s \\rightarrow K^+K^-$ lifetime is presented using approximately $37 pb^{-1}$ of data collected by LHCb during 2010. This quantity can be used to put constraints on contributions from processes beyond the Standard Model in the $B_s$ meson system and is determined by two complementary approaches as $\\tau_{B_s\\to K^+K^-} = 1.440 \\pm 0.096 (stat) \\pm 0.008 (syst) \\pm 0.003 (model) ps$.

Detection of MPLW515L/K mutations and determination of allele frequencies with a single-tube PCR assay.

Science.gov (United States)

Takei, Hiraku; Morishita, Soji; Araki, Marito; Edahiro, Yoko; Sunami, Yoshitaka; Hironaka, Yumi; Noda, Naohiro; Sekiguchi, Yuji; Tsuneda, Satoshi; Ohsaka, Akimichi; Komatsu, Norio

2014-01-01

A gain-of-function mutation in the myeloproliferative leukemia virus (MPL) gene, which encodes the thrombopoietin receptor, has been identified in patients with essential thrombocythemia and primary myelofibrosis, subgroups of classic myeloproliferative neoplasms (MPNs). The presence of MPL gene mutations is a critical diagnostic criterion for these diseases. Here, we developed a rapid, simple, and cost-effective method of detecting two major MPL mutations, MPLW515L/K, in a single PCR assay; we termed this method DARMS (dual amplification refractory mutation system)-PCR. DARMS-PCR is designed to produce three different PCR products corresponding to MPLW515L, MPLW515K, and all MPL alleles. The amplicons are later detected and quantified using a capillary sequencer to determine the relative frequencies of the mutant and wild-type alleles. Applying DARMS-PCR to human specimens, we successfully identified MPL mutations in MPN patients, with the exception of patients bearing mutant allele frequencies below the detection limit (5%) of this method. The MPL mutant allele frequencies determined using DARMS-PCR correlated strongly with the values determined using deep sequencing. Thus, we demonstrated the potential of DARMS-PCR to detect MPL mutations and determine the allele frequencies in a timely and cost-effective manner.

Detection of MPLW515L/K mutations and determination of allele frequencies with a single-tube PCR assay.

Directory of Open Access Journals (Sweden)

Hiraku Takei

Full Text Available A gain-of-function mutation in the myeloproliferative leukemia virus (MPL gene, which encodes the thrombopoietin receptor, has been identified in patients with essential thrombocythemia and primary myelofibrosis, subgroups of classic myeloproliferative neoplasms (MPNs. The presence of MPL gene mutations is a critical diagnostic criterion for these diseases. Here, we developed a rapid, simple, and cost-effective method of detecting two major MPL mutations, MPLW515L/K, in a single PCR assay; we termed this method DARMS (dual amplification refractory mutation system-PCR. DARMS-PCR is designed to produce three different PCR products corresponding to MPLW515L, MPLW515K, and all MPL alleles. The amplicons are later detected and quantified using a capillary sequencer to determine the relative frequencies of the mutant and wild-type alleles. Applying DARMS-PCR to human specimens, we successfully identified MPL mutations in MPN patients, with the exception of patients bearing mutant allele frequencies below the detection limit (5% of this method. The MPL mutant allele frequencies determined using DARMS-PCR correlated strongly with the values determined using deep sequencing. Thus, we demonstrated the potential of DARMS-PCR to detect MPL mutations and determine the allele frequencies in a timely and cost-effective manner.

High resolution luminescence chronology for Xiashu Loess deposits of Southeastern China

Science.gov (United States)

Yi, Shuangwen; Li, Xusheng; Han, Zhiyong; Lu, Huayu; Liu, Jinfeng; Wu, Jiang

2018-04-01

Loess deposits in Xiashu are representative of such deposits in Southeastern China that are mainly distributed in the middle and lower reaches of the Yangtze River valley. These loess-paleosol sequences provide a key archive of past climate change in humid, subtropical regions. However, the ages of the sequences are not well constrained. In this study, the standard quartz single-aliquot regenerative (SAR) dose optically stimulated luminescence (OSL) and K-feldspar post-infrared infrared stimulated luminescence (post-IR IRSL; pIRIR290) methods are used to date two loess sequences in Nanjing region. Our results show that quartz SAR OSL and K-feldspar pIRIR290 ages are more or less indistinguishable from one another up to ∼50 ka. Beyond this age, the K-feldspar pIRIR ages increased systematically with deposition depth, agreeing well with the expected ages as far as ∼200 ka. On the basis of a fully independently-dated timescale, we are therefore able to propose, for the first time, a new age model for the Xiashu Loess deposits accumulated since the penultimate interglacial period. Using our newly obtained luminescence dating ages, we observe a marked difference between the loess accumulation rates in the two sequences, potentially forced by regional depositional processes and loess preservation.

[Prophylactic vitamin K for vitamin K deficiency bleeding of the newborn].

Science.gov (United States)

Martín-López, J E; Carlos-Gil, A M; Rodríguez-López, R; Villegas-Portero, R; Luque-Romero, L; Flores-Moreno, S

2011-01-01

The administration of vitamin K immediately after birth has shown a significant decrease in the incidence of newborn bleeding, but there is not enough evidence to determine the most appropriate method of administration. The objective of this review is to determine the effectiveness of orally administered vitamin K compared to the intramuscular route in the prevention of hemorrhagic disease of newborn (HDN). We conducted a systematic review of the main databases (Medline, Embase and Cochrane, among others) without limitation by date, language or type of study. Selected studies evaluated the efficacy and safety of vitamin K. Excluded were studies in pregnant women in preterm infants or patients with pathology. The validity of these studies was assessed by CASPe tools for systematic reviews and clinical trials. Only two studies evaluated clinical aspects. They showed a reduction in the incidence of bleeding in the newborn after intramuscular prophylaxis with vitamin K. With regard to the oral route, different studies examined the effectiveness of vitamin K by determining biochemical parameters (factor X, prothrombin time and index, vitamin K1 in plasma and prothrombin antigen, among others) with inconclusive results regarding the route of administration and the number of doses. There is sufficient evidence to support the effectiveness of a single intramuscular dose of vitamin K to prevent the classic form of HDN. With regard to late HDN and oral route, the results are inconclusive because the studies used biochemical indicators of effectiveness, which can not be correlated with the actual coagulation status of the newborn due to lack of scientific evidence. Copyright © 2010 SEFH. Published by Elsevier Espana. All rights reserved.

Cambios en las propiedades luminiscentes de un feldespato potásico inducidos por efecto térmico y exposición a infrarrojo

OpenAIRE

Correcher, V.; García-Guinea, J.

2004-01-01

Luminescence properties of quartz and feldspars, main components of traditional ceramic materials (bricks, tiles or porcelains), change considerably during the manufactured process that involves a heating treatment up to ∼900ºC (bricks) or ∼1200ºC (porcelains). The aim of this paper is the study of the change the luminescence properties of a well characterised K-rich feldspar (KAlSi3O8) when (i) thermal treatment and (ii) infrared exposure are performed. It could be appreciated an increase in...

Effective lifetime measurements in the $B_{s}^{0} \\rightarrow K^{+}K^{-}$, $B^{0} \\rightarrow K^{+}\\pi^{-}$ and $B_{s}^{0} \\rightarrow \\pi^{+}K^{-}$ decays

CERN Document Server

INSPIRE-00258707; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves Jr, A.A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreassen, R.; Andreotti, M.; Andrews, J.E.; Appleby, R.B.; Aquines Gutierrez, O.; Archilli, F.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J.J.; Badalov, A.; Balagura, V.; Baldini, W.; Barlow, R.J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Bauer, Th.; Bay, A.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Belogurov, S.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bettler, M.O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Bird, T.; Bizzeti, A.; Bjornstad, P.M.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borgia, A.; Borsato, M.; Bowcock, T.J.V.; Bowen, E.; Bozzi, C.; Brambach, T.; van den Brand, J.; Bressieux, J.; Brett, D.; Britsch, M.; Britton, T.; Brook, N.H.; Brown, H.; Bursche, A.; Busetto, G.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Camboni, A.; Campana, P.; Campora Perez, D.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carranza-Mejia, H.; Carson, L.; Carvalho Akiba, K.; Casse, G.; Cassina, L.; Garcia, L.Castillo; Cattaneo, M.; Cauet, Ch.; Cenci, R.; Charles, M.; Charpentier, Ph.; Cheung, S.F.; Chiapolini, N.; Chrzaszcz, M.; Ciba, K.; Cid Vidal, X.; Ciezarek, G.; Clarke, P.E.L.; Clemencic, M.; Cliff, H.V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Corvo, M.; Counts, I.; Couturier, B.; Cowan, G.A.; Craik, D.C.; Cruz Torres, M.; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Dalseno, J.; David, P.; David, P.N.Y.; Davis, A.; De Bruyn, K.; De Capua, S.; De Cian, M.; de Miranda, J.M.; De Paula, L.; De Silva, W.; De Simone, P.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Deleage, N.; Derkach, D.; Deschamps, O.; Dettori, F.; Di Canto, A.; Dijkstra, H.; Donleavy, S.; Dordei, F.; Dorigo, M.; Dosil Suarez, A.; Dossett, D.; Dovbnya, A.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Esen, S.; Evans, T.; Falabella, A.; Farber, C.; Farinelli, C.; Farley, N.; Farry, S.; Ferguson, D.; Fernandez Albor, V.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Garofoli, J.; Garra Tico, J.; Garrido, L.; Gaspar, C.; Gauld, R.; Gavardi, L.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianelle, A.; Giani', S.; Gibson, V.; Giubega, L.; Gligorov, V.V.; Gobel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gordon, H.; Gotti, C.; Grabalosa Gandara, M.; Graciani Diaz, R.; Granado Cardoso, L.A.; Grauges, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griffith, P.; Grillo, L.; Grunberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S.C.; Hall, S.; Hamilton, B.; Hampson, T.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S.T.; Harrison, J.; Hartmann, T.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; Hernando Morata, J.A.; van Herwijnen, E.; Hess, M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Hunt, P.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jaton, P.; Jawahery, A.; Jezabek, M.; Jing, F.; John, M.; Johnson, D.; Jones, C.R.; Joram, C.; Jost, B.; Jurik, N.; Kaballo, M.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T.M.; Kelsey, M.; Kenyon, I.R.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koopman, R.F.; Koppenburg, P.; Korolev, M.; Kozlinskiy, A.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kucharczyk, M.; Kudryavtsev, V.; Kurek, K.; Kvaratskheliya, T.; La Thi, V.N.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lambert, R.W.; Lanciotti, E.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J.P.; Lefevre, R.; Leflat, A.; Lefrancois, J.; Leo, S.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Liles, M.; Lindner, R.; Linn, C.; Lionetto, F.; Liu, B.; Liu, G.; Lohn, S.; Longstaff, I.; Lopes, J.H.; Lopez-March, N.; Lowdon, P.; Lu, H.; Lucchesi, D.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Machefert, F.; Machikhiliyan, I.V.; Maciuc, F.; Maev, O.; Malde, S.; Manca, G.; Mancinelli, G.; Manzali, M.; Maratas, J.; Marchand, J.F.; Marconi, U.; Benito, C.Marin; Marino, P.; Marki, R.; Marks, J.; Martellotti, G.; Martens, A.; Martin Sanchez, A.; Martinelli, M.; Martinez Santos, D.; Martinez Vidal, F.; Martins Tostes, D.; Massafferri, A.; Matev, R.; Mathe, Z.; Matteuzzi, C.; Mazurov, A.; McCann, M.; McCarthy, J.; McNab, A.; McNulty, R.; McSkelly, B.; Meadows, B.; Meier, F.; Meissner, M.; Merk, M.; Milanes, D.A.; Minard, M.N.; Moggi, N.; Molina Rodriguez, J.; Monteil, S.; Moran, D.; Morandin, M.; Morawski, P.; Morda, A.; Morello, M.J.; Moron, J.; Mountain, R.; Muheim, F.; Muller, K.; Muresan, R.; Mussini, M.; Muster, B.; Naik, P.; Nakada, T.; Nandakumar, R.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A.D.; Nguyen, T.D.; Nguyen-Mau, C.; Nicol, M.; Niess, V.; Niet, R.; Nikitin, N.; Nikodem, T.; Novoselov, A.; Oblakowska-Mucha, A.; Obraztsov, V.; Oggero, S.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Onderwater, G.; Orlandea, M.; Otalora Goicochea, J.M.; Owen, P.; Oyanguren, A.; Pal, B.K.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Parkes, C.; Parkinson, C.J.; Passaleva, G.; Patel, G.D.; Patel, M.; Patrignani, C.; Pazos Alvarez, A.; Pearce, A.; Pellegrino, A.; Pepe Altarelli, M.; Perazzini, S.; Perez Trigo, E.; Perret, P.; Perrin-Terrin, M.; Pescatore, L.; Pesen, E.; Petridis, K.; Petrolini, A.; Picatoste Olloqui, E.; Pietrzyk, B.; Pilar, T.; Pinci, D.; Pistone, A.; Playfer, S.; Plo Casasus, M.; Polci, F.; Poluektov, A.; Polycarpo, E.; Popov, A.; Popov, D.; Popovici, B.; Potterat, C.; Powell, A.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Puig Navarro, A.; Punzi, G.; Qian, W.; Rachwal, B.; Rademacker, J.H.; Rakotomiaramanana, B.; Rama, M.; Rangel, M.S.; Raniuk, I.; Rauschmayr, N.; Raven, G.; Reichert, S.; Reid, M.M.; dos Reis, A.C.; Ricciardi, S.; Richards, A.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Roa Romero, D.A.; Robbe, P.; Rodrigues, A.B.; Rodrigues, E.; Rodriguez Perez, P.; Roiser, S.; Romanovsky, V.; Vidal, A.Romero; Rotondo, M.; Rouvinet, J.; Ruf, T.; Ruffini, F.; Ruiz, H.; Valls, P.Ruiz; Sabatino, G.; Saborido Silva, J.J.; Sagidova, N.; Sail, P.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santovetti, E.; Sapunov, M.; Sarti, A.; Satriano, C.; Satta, A.; Savrie, M.; Savrina, D.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmidt, B.; Schneider, O.; Schopper, A.; Schune, M.H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Seco, M.; Semennikov, A.; Senderowska, K.; Sepp, I.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Shires, A.; Coutinho, R.Silva; Simi, G.; Sirendi, M.; Skidmore, N.; Skwarnicki, T.; Smith, N.A.; Smith, E.; Smith, E.; Smith, J.; Smith, M.; Snoek, H.; Sokoloff, M.D.; Soler, F.J.P.; Soomro, F.; Souza, D.; Souza De Paula, B.; Spaan, B.; Sparkes, A.; Spinella, F.; Spradlin, P.; Stagni, F.; Stahl, S.; Steinkamp, O.; Stenyakin, O.; Stevenson, S.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Stroili, R.; Subbiah, V.K.; Sun, L.; Sutcliffe, W.; Swientek, K.; Swientek, S.; Syropoulos, V.; Szczekowski, M.; Szczypka, P.; Szilard, D.; Szumlak, T.; T'Jampens, S.; Teklishyn, M.; Tellarini, G.; Teubert, F.; Thomas, C.; Thomas, E.; van Tilburg, J.; Tisserand, V.; Tobin, M.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Tran, M.T.; Tresch, M.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Garcia, M.Ubeda; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vagnoni, V.; Valenti, G.; Vallier, A.; Vazquez Gomez, R.; Vazquez Regueiro, P.; Vazquez Sierra, C.; Vecchi, S.; Velthuis, J.J.; Veltri, M.; Veneziano, G.; Vesterinen, M.; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Vilasis-Cardona, X.; Vollhardt, A.; Volyanskyy, D.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voss, C.; Voss, H.; de Vries, J.A.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wandernoth, S.; Wang, J.; Ward, D.R.; Watson, N.K.; Websdale, D.; Whitehead, M.; Wicht, J.; Wiedner, D.; Wilkinson, G.; Williams, M.P.; Williams, M.; Wilson, F.F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S.A.; Wright, S.; Wu, S.; Wyllie, K.; Xie, Y.; Xing, Z.; Xu, Z.; Yang, Z.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zavertyaev, M.; Zhang, F.; Zhang, L.; Zhang, W.C.; Zhang, Y.; Zhelezov, A.; Zhokhov, A.; Zhong, L.; Zvyagin, A.

2014-01-01

Measurements of the effective lifetimes in the $B_{s}^{0} \\rightarrow K^{+}K^{-}$, $B^{0} \\rightarrow K^{+}\\pi^{-}$ and $B_{s}^{0} \\rightarrow \\pi^{+}K^{-}$ decays are presented using $1.0~\\mathrm{fb^{-1}}$ of $pp$ collision data collected at a centre-of-mass energy of 7 TeV by the LHCb experiment. The analysis uses a data-driven approach to correct for the decay time acceptance. The measured effective lifetimes are $\\tau_{B_{s}^{0} \\rightarrow K^{+}K^{-}}$ = $1.407~\\pm~0.016~\\pm~0.007~\\mathrm{ps}$, $\\tau_{B^{0} \\rightarrow K^{+}\\pi^{-}}$ = $1.524~\\pm~0.011~\\pm~0.004~\\mathrm{ps}$, $\\tau_{B_{s}^{0} \\rightarrow \\pi^{+}K^{-}}$ = $1.60~\\pm~0.06~\\pm~0.01~\\mathrm{ps}$. This is the most precise determination to date of the effective lifetime in the $B_{s}^{0} \\rightarrow K^{+}K^{-}$ decay and provides constraints on contributions from physics beyond the Standard Model to the $B_{s}^{0}$ mixing phase and the width difference $\\Delta\\Gamma_{s}$.

Measurement of CP Asymmetry in B0 --> K+K-K0S Decays

International Nuclear Information System (INIS)

Dujmic, D

2004-01-01

The authors present preliminary measurements of the CP asymmetry parameters and CP content in B 0 --> K + K - K s 0 decays, with φK s 0 events excluded. In a sample of 227 M B(bar B) pairs collected by the BABAR detector at the PEP-II B Factory at SLAC, they find the CP parameters to be S = -0.42 ± 0.17 ± 0.04 and C = 0.10 ± 0.14 ± 0.06, where the first error is statistical and the second systematic. Extracting the fraction of CP-even final states from angular moments f even = 0.89 ± 0.08 ± 0.06, and setting C = 0, they determine sin 2β = 0.55 ± 0.22 ± 0.04 ± 0.11, where the last error is due to uncertainty on the CP content

Viscosities of cesium vapor to 1,620 K and of liquid gallium to 1,800 K

International Nuclear Information System (INIS)

Tippelskirch, H. v.

1976-01-01

The viscosity of cesium at 1,620 K and 40 bar has been determined to 41 x 10 -6 (Pa x s) by the oscillating cup method. The saturated vapor density at 1,580 K could be derived from the viscosity measurements. The viscosity of liquid gallium has been determined from 370 K to 1,800 K. The experimental results have been compared with calculations based on the Enskog hard-sphere transport theory for dense fluids. (orig.) [de

On the measurement of the crack tip stress field as a means of determining Delta K(sub eff) under conditions of fatigue crack closure

Science.gov (United States)

Wallhead, Ian R.; Edwards, Lyndon; Poole, Peter

1994-01-01

The optical method of caustics has been successfully extended to enable stress intensity factors as low as 1MPa square root of m to be determined accurately for central fatigue cracks in 2024-T3 aluminium alloy test panels. The feasibility of using this technique to study crack closure, and to determine the effective stress intensity factor range, Delta K(sub eff), has been investigated. Comparisons have been made between the measured values of stress intensity factor, K(sub caus), and corresponding theoretical values, K(sub theo), for a range of fatigue cracks grown under different loading conditions. The values of K(sub caus) and K(sub theo) were in good agreement at maximum stress, where the cracks are fully open, while K(sub caus) exceeded K(sub theo) at minimum stress, due to crack closure. However, the levels of crack closure and values of Delta K(sub eff) obtained could not account for the variations of crack growth rate with loading conditions. It is concluded that the values of Delta K(sub eff), based on caustic measurements in a 1/square root of r stress field well outside the plastic zone, do not fully reflect local conditions which control crack tip behavior.

Determination of conversion factors of kerma and fluence to ambient dose equivalent for X-rays generated between 50 kVp to 125 kVp

International Nuclear Information System (INIS)

Nogueira, Maria do Socorro

1997-01-01

The ambient dose equivalent was determined experimentally on the interval of energy of X ray applied in diagnostic radiology. A PMMA sphere was used to simulate the trunk human (phantom), based on the definition of the report ICRU 39. The absorbed dose in different positions in the phantom was determined using LiF-TLD 100. The X ray spectra were measured with a high-purity germanium detector (HP Ge). It was also determined the HVL and the effective energy in this energy range. The conversion coefficient of the K air and Φ to H * (d) were determined to 10, 50 and 60 mm deep in the PMMA sphere. The obtained values were compared with data of the literature. The maximum uncertainty obtained for the coefficients was 7.2%. All parameters were also determined to the X ray quality of the incident and transmitted beam by the patient, according to the recommendation of the standard DIN 6872. The conversion factor was calculated for those situations where the X-ray beam is transmitted by a layer and Pb and it is necessary to estimate the effective dose, as in the case of shielding project of radiology diagnosis room. (author)

Determination of lutetium (III) hydrolysis constants in the middle of ion force 1M sodium chloride at 303 K

International Nuclear Information System (INIS)

Jimenez R, M.; Solache R, M.J.; Ramirez G, J.J.; Rojas H, A.

1997-01-01

With the purpose to complete information about the lutetium (III) hydrolysis constants here is used the potentiometric method to determine those in the middle of ion force 1M sodium chloride at 303 K. (Author)

Clay-mineral assemblages from some levels of K-118 drill core of Maha Sarakham evaporites, northeastern Thailand

Science.gov (United States)

Suwanich, Parkorn

Clay-mineral assemblages in Middle Clastic, Middle Salt, Lower Clastic, Potash Zone, and Lower Salt, totalling 13 samples from K-118 drill core, in the Maha Sarakham Formation, Khorat Basin, northeastern Thailand were studied. The clay-size particles were separated from the water-soluble salt by water leaching. Then the samples were leached again in the EDTA solution and separated into clay-size particles by using the timing sedimentation. The EDTA-clay residues were divided and analyzed by using the XRD and XRF method. The XRD peaks show that the major-clay minerals are chlorite, illite, and mixed-layer corrensite including traces of rectorite? and paragonite? The other clay-size particles are quartz and potassium feldspar. The XRF results indicate Mg-rich values and moderate MgAl atom ratio values in those clay minerals. The variable Fe, Na, and K contents in the clay-mineral assemblages can explain the environment of deposition compared to the positions of the samples from the core. Hypothetically, mineralogy and the chemistry of the residual assemblages strongly indicate that severe alteration and Mg-enrichment of normal clay detritus occurred in the evaporite environment through brine-sediment interaction. The various Mg-enrichment varies along the various members reflecting whether sedimentation is near or far from the hypersaline brine.

Novel aspects of Na+,K+-ATPase

OpenAIRE

Aizman, Oleg

2002-01-01

Na,K-ATPase, an integral membrane protein expressed in each eukaryotic cell, serves as the major determinant of intracellular ion composition. In the current study we investigated novel aspects of Na,K-ATPase function and regulation. It is well established that Na,K-ATPase activity is regulated by reversible phosphorylation. New findings in this study are: 1) the level of intracellular Ca 2. concentration determines the functional effects of PKA and PKC-mediated Na,K-ATP...

KEY COMPARISON: CCQM-K27-Subsequent: Key Comparison (subsequent) for the determination of ethanol in aqueous matrix

Science.gov (United States)

Schantz, Michele M.; Duewer, David L.; Parris, Reenie M.; May, Willie E.; Archer, Marcellé; Mussell, Chris; Carter, David; Konopelko, Leonid A.; Kustikov, Yury A.; Krylov, Anatoli I.; Fatina, Olga V.

2005-01-01

Ethanol is important both forensically ('drunk driving' or driving while under the influence, 'DWI', regulations) and commercially (alcoholic beverages). Blood- and breath-alcohol testing can be imposed on individuals operating private vehicles such as cars, boats, or snowmobiles, or operators of commercial vehicles like trucks, planes, and ships. The various levels of blood alcohol that determine whether these operators are considered legally impaired vary depending on the circumstances and locality. Accurate calibration and validation of instrumentation is critical in areas of forensic testing where quantitative analysis directly affects the outcome of criminal prosecutions, as is the case with the determination of ethanol in blood and breath. Additionally, the accurate assessment of the alcoholic content of beverages is a commercially important commodity. In 2002, the CCQM conducted a Key Comparison (CCQM-K27) for the determination of ethanol in aqueous matrix with nine participants. A report on this project has been approved by the CCQM and can be found at the BIPM website and in this Technical Supplement. CCQM-K27 comprised three samples, one at low mass fraction of ethanol in water (nominal concentration of 0.8 mg/g), one at high level (nominal concentration of 120 mg/g), and one wine matrix (nominal concentration of 81 mg/g). Overall agreement among eight participants using gas chromatography with flame ionization detection (GC-FID), titrimetry, isotope dilution gas chromatography/mass spectrometry (GC-IDMS), and gas chromatography-combustion-isotope ratio mass spectrometry (ID-GC-C-IRMS) was good. The ninth participant used a headspace GC-FID method that had not been validated in an earlier pilot study (CCQM-P35). A follow-on Key Comparison, CCQM-K27-Subsequent, was initiated in 2003 to accommodate laboratories that had not been ready to benchmark their methods in the original CCQM-K27 study or that wished to benchmark a different method. Four levels of

Effects of K{sup 0}−K-bar{sup 0} mixing on determining γ from B{sup ±}→DK{sup ±}

Energy Technology Data Exchange (ETDEWEB)

Grossman, Yuval; Savastio, Michael [Department of Physics, LEPP, Cornell University,Ithaca, NY 14853 (United States)

2014-03-03

The decay B{sup ±}→DK{sup ±} followed by the subsequent decay of the D meson into final states involving a neutral kaon can be used to determine the CKM angle γ. We study CP violation effects due to mixing and decay of the final state kaon. We find that ignoring these effects produces a shift in γ of order ϵ{sub K}/r{sub B}, an enhancement of 1/r{sub B} compared to the naive expectation. We then show how to take these effects into account such that, in principle, they will not introduce any theoretical error in the extraction of γ.

The magma plumbing system in the Mariana Trough back-arc basin at 18° N

Science.gov (United States)

Lai, Zhiqing; Zhao, Guangtao; Han, Zongzhu; Huang, Bo; Li, Min; Tian, Liyan; Liu, Bo; Bu, Xuejiao

2018-04-01

Mafic magmas are common in back-arc basin, once stalled in the crust, these magmas may undergo different evolution. In this paper, compositional and textural variations of plagioclase as well as mineral-melt geothermobarometry are presented for basalts erupted from the central Mariana Trough (CMT). These data reveal crystallization conditions and we attempt a reconstruction of the magma plumbing system of the CMT. Plagioclase megacrysts, phenocrysts, microphenocrysts, microlites, olivine, spinel, and clinopyroxene have been recognized in basalt samples, using BSE images and compositional features. The last three minerals are homogeneous as microphenocrysts. Mineral-melt barometry indicates that plagioclase crystals crystallized and eventually grew into phenocrysts and megacrysts in mush zone with depth of 5-9 km, in which the normal zoning plagioclases crystallized in the interval of various batches of basic magma recharging. Plagioclase megacrysts and phenocrysts were dissolved and/or resorbed, when new basic magmas injected into the mush zone near Moho depth. It is inferred that magma extracted from the mush zone, and adiabatically ascended via different pathways. Some basaltic magmas underwent plagioclase and clinopyroxene microphenocrysts crystallization in low-pressure before eruption. Plagioclase microlites and outermost rims probably crystallized after eruption.

Determination of {sup 40}K in water samples; Determinacion del {sup 40}K en muestras de agua

Energy Technology Data Exchange (ETDEWEB)

Delgado, C. E.; Miranda C, L.; Cuevas J, A. K.; Vega C, H. R., E-mail: rmfranccesco0223@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

2014-10-15

The natural water used for human consumption comes from different sources, which may contain suspended solids in varying proportions. In groundwater, the source of suspended solids is related to the dissolution of mineral strata by the waters and leaching of rocks. Also, the radioactivity could concentrate on the bodies of slow-moving water that eventually could present a risk to ecosystems, as well as for the consumer. The water usually contains several natural radionuclides as: tritium, radon, radio, uranium isotopes, etc. The objective of this study was to evaluate the concentration of {sup 40}K in water from different areas of Zacatecas state (Mexico). Four water samples were taken in triplicate from different areas; the {sup 40}K concentration was measured with a spectrum metric system of gamma radiation with NaI (Tl) scintillation detector of 7.62 cm. In the measuring process a standard was prepared using water and KCl analytic grade where the {sup 40}K concentration is 6.25 mol/Lt adding 250 mg/ml of potassium. Also the system was calibrated in energy using 3 point sources of {sup 137}Cs, diameter {sup 22}Na and 7.62 cm of height, using containers Marinelli and {sup 60}Co. In the obtained spectra was observed that the photon of 1.432 MeV that emits the {sup 40}K when decaying is the most important. The highest concentration was of 123 ± 5.2 Bq/lt and the lowest was of 9 ± 0.4 Bq/lt. Under the standards of drinking water, an amount of {sup 40}K deposits an effective dose which contributes to annual dose received by people. (Author)

Sorption of niobium on boreal forest soil

Energy Technology Data Exchange (ETDEWEB)

Soederlund, Mervi; Hakanen, Martti; Lehto, Jukka [Helsinki Univ. (Finland). Lab. of Radiochemistry

2015-07-01

The sorption of niobium (Nb) was investigated on humus and mineral soil samples taken from various depths of a four-metre deep forest soil pit on Olkiluoto Island, southwestern Finland. Mass distribution coefficients, K{sub d}, were determined in batch sorption tests. The steady state of Nb sorption was observed in the mineral soil samples already after one week of equilibration, and sorption decreased with depth from a very high value of 185000 mL/g at 0.7 m to 54000 mL/g at 3.4 m. The reason behind this decrease is probably the tenfold reduction in the specific surface area of the soil at the same depth range. Distribution coefficients were clearly lower in the humus layer (1000 mL/g). The K{sub d} values determined in pure water at a pH range of 4.7-6.5 were at a high level (above 55000 mL/g), but decreased dramatically above pH 6.5, corresponding to the change in the major Nb species from the neutral Nb(OH){sub 5} to the low-sorbing anionic Nb(OH){sub 6}{sup -} and Nb(OH){sub 7}{sup 2-}. However, the K{sub d} values in the model soil solution were in the slightly alkaline range an order of magnitude higher than in pure water, which is probably caused by the formation of calcium niobate surface precipitate or electrostatic interaction between surface-sorbed calcium and solute Nb. Among nine soil constituent minerals kaolinite performed best in retaining Nb in both pure water and model soil solution at pH 8, whereas potassium feldspar showed the poorest sorption. The K{sub d} value for kaolinite was above 500000 mL/g in both solutions, while the respective potassium feldspar values were in the range of 120-220 mL/g.

Progress in Primary Acoustic Thermometry at NIST: 273 K to 505 K

Science.gov (United States)

Strouse, G. F.; Defibaugh, D. R.; Moldover, M. R.; Ripple, D. C.

2003-09-01

The NIST Acoustic Thermometer determines the thermodynamic temperature by measuring the speed of sound of argon in a spherical cavity. We obtained the thermodynamic temperature of three fixed points on the International Temperature Scale of 1990: the melting point of gallium [T(Ga) = 302.9146 K] and the freezing points of indium [T(In) = 429.7485 K] and tin [T(Sn) = 505.078 K]. The deviations of thermodynamic temperature from the ITS-90 defined temperatures are T - T90 = (4.7 ± 0.6) mK at T(Ga) , T - T90 = (8.8 ± 1.5) mK at T(In) , and T - T90 = (10.7 ± 3.0) mK at T(Sn) , where the uncertainties are for a coverage factor of k = 1. Our results at T(In) and T(Sn) reduce the uncertainty of T - T90 by a factor of two in this range. Both T - T90 at T(Ga) and the measured thermal expansion of the resonator between the triple point of water and T(Ga) are in excellent agreement with the 1992 determination at NIST. The dominant uncertainties in the present data come from frequency-dependent and time-dependent crosstalk between the electroacoustic transducers. We plan to reduce these uncertainties and extend this work to 800 K.

A simple transformation for converting CW-OSL curves to LM-OSL curves

DEFF Research Database (Denmark)

Bulur, E.

2000-01-01

A simple mathematical transformation is introduced to convert from OSL decay curves obtained in the conventional way to those obtained using a linear modulation technique based on a linear increase of the stimulation light intensity during OSL measurement. The validity of the transformation...... was tested by the IR-stimulated luminescence curves from feldspars, recorded using both the conventional and the linear modulation techniques. The transformation was further applied to green-light-stimulated OSL from K and Na feldspars. (C) 2000 Elsevier Science Ltd. All rights reserved....

The study of water droplets electrical charging effect on spray tower scrubber efficiency for feldspar particles removal

Directory of Open Access Journals (Sweden)

R Golmohammadi

2012-01-01

Full Text Available Background and aims: One of the modern ways introduced nowadays for increasing the collection efficiency of particulate, is the use of electric charge in wet scrubbers. These systems can be used in places in which scrubbers are suitable for contaminant collection. In fact, this system only increases the collection efficiency, and it is not a new technology for contaminant collection.   Methods: First, according to ACGIH recommendation for pilot study a ventilation system was designed and installed. Later, water was charged by using an DC electric exchanger (1275 Volt, DC& product 3×1014 electron on system. Air velocity in the duct was determined by Pitot tube, pressure drop and speed equations, and sampling prop diameter was calculated considering isokenetic conditions. Sampling was performed at two flow rates of 20.3 and 11.4 liter per minute and in overall 72 samples were collected. Sample analysis was performed using gravimetric method and data analysis was performed using SPSS software.      Results: The collection efficiency of inhalable particles in the flow rate of 20.3 liter per minute in a non-electric intervention, and electric intervention with positive and negative charge was 66, 77.67 and 73 percent and in the flow rate of 11.4 liters per minute 60, 69.43 and 68.32 percent respectively. For non-inhalable particles the efficiency in the flow rate 20.3 liter per minute in a non-electric intervention and electric intervention with positive and negative charge was 94.67, 98.33 and 97.67 percent, and in the flow charge of 11/4 liter per minute the flow charge was 91.33, 95, and 97.33 percent respectively.  Conclusion: The results obtained from the experiments, showed that in a certain flow rate, electric intervention increases the efficiency of inhalable particle collection. By the way, this electric intervention has no significant effect on non-inhalable particle collection. Also, the effect of electric intervention with

On the determination of the water energy dose for X-rays produced with high voltages up to 100 kV

International Nuclear Information System (INIS)

Engelke, B.A.; Grosswendt, B.

1989-01-01

For X-rays produced with high-tensions up to 100 kV the absorbed dose to water in water can be determined by measuring the exposure or air kerma and by means of the calibration factor of the dosemeter for these quantities and a conversion factor and a correction factor. For this procedure it is necessary that the exposure or air kerma measured and the correction factor are referred to the same diameter of the X-ray beam and the same measuring distance as used for the determination of the calibration factor. If they do not agree, an additional correction factor for the influence of this discrepancy in the measuring geometry is needed. The paper gives the values of this correction factor. Furthermore, it informs on new values of the backscattering factor in water and of the correction k a→w required for the determination of the absorbed dose to water in water. (orig.) [de

Radiometric, SEM and XRD investigation of the Chituc black sands, southern Danube Delta, Romania

International Nuclear Information System (INIS)

Margineanu, R.M.; Blebea-Apostu, Ana-Maria; Celarel, Aurelia; Gomoiu, Claudia-Mariana; Costea, C.; Dumitras, Delia; Ion, Adriana; Duliu, O.G.

2014-01-01

The black sand of the Chituc marine sand bank, northern of the city of Navodari (Romania), presents anomalous high radioactivity. Field measurements recorded in some places dose rate up to 200 nSv/h, significantly overpassing the average value of 44 ± 20 nSv/h along the entire Southern sector of Romanian Black Sea shore. Gamma ray spectrometry performed on both Slanic-Prahova Underground Low Background Laboratory and Geological Institute of Romania Radiometric Facilities showed with clarity the dominance of 228 Ac radioisotope in the 50 microns fraction together with the 226 Ra and traces of 40 K. No significant amount of anthropogenic 137 Cs was identified. Based on radiometric as well as on SEM–EDAX and XRD determinations we come to the conclusion that the evidenced radioactivity could be attributed to both uranium and thorium series in the zircon and monazite fractions and to a lesser extent to potassium in the feldspars. - Highlights: • High background radioactivity (up to 200 nSv/h) evidenced. • Radiometric measurements showed a maximum radioactivity of U and Th confined to 50–100 μm fraction. • XRD and SEM–EDAX data revealed the presence of k-feldspars, ilmenite, zircone, monazite and garnets

The Electrogenic Na+/K+ Pump Is a Key Determinant of Repolarization Abnormality Susceptibility in Human Ventricular Cardiomyocytes: A Population-Based Simulation Study

Directory of Open Access Journals (Sweden)

Oliver J. Britton

2017-05-01

Full Text Available Background: Cellular repolarization abnormalities occur unpredictably due to disease and drug effects, and can occur even in cardiomyocytes that exhibit normal action potentials (AP under control conditions. Variability in ion channel densities may explain differences in this susceptibility to repolarization abnormalities. Here, we quantify the importance of key ionic mechanisms determining repolarization abnormalities following ionic block in human cardiomyocytes yielding normal APs under control conditions.Methods and Results: Sixty two AP recordings from non-diseased human heart preparations were used to construct a population of human ventricular models with normal APs and a wide range of ion channel densities. Multichannel ionic block was applied to investigate susceptibility to repolarization abnormalities. IKr block was necessary for the development of repolarization abnormalities. Models that developed repolarization abnormalities over the widest range of blocks possessed low Na+/K+ pump conductance below 50% of baseline, and ICaL conductance above 70% of baseline. Furthermore, INaK made the second largest contribution to repolarizing current in control simulations and the largest contribution under 75% IKr block. Reversing intracellular Na+ overload caused by reduced INaK was not sufficient to prevent abnormalities in models with low Na+/K+ pump conductance, while returning Na+/K+ pump conductance to normal substantially reduced abnormality occurrence, indicating INaK is an important repolarization current.Conclusions: INaK is an important determinant of repolarization abnormality susceptibility in human ventricular cardiomyocytes, through its contribution to repolarization current rather than homeostasis. While we found IKr block to be necessary for repolarization abnormalities to occur, INaK decrease, as in disease, may amplify the pro-arrhythmic risk of drug-induced IKr block in humans.

Determination of Na, Cl, Ca, Mg, Mn and K in milk samples by activation analysis

International Nuclear Information System (INIS)

Kira, Carmen S.; Maihara, Vera A.

2000-01-01

In the present work cow milk samples distributed for Sao Paulo government institutions, by means of the 'Viva leite' programme, have been monitored. The concentrations of Ca, Cl, K, Mg, Mn and Na were determined in five milk samples and in three different kinds of commercial powder milk, by instrumental neutron activation. For quality control, the reference materials NIST whole milk powder and non fat milk powder were analysed. The results obtained are in the range of the concentrations mentioned in the literature for these elements. (author)

Function of minerals in the natural radioactivity level of Vaigai River sediments, Tamilnadu, India--spectroscopical approach.

Science.gov (United States)

Ramasamy, V; Paramasivam, K; Suresh, G; Jose, M T

2014-01-03

Using Gamma ray and Fourier Transform Infrared (FTIR) spectroscopic techniques, level of natural radioactivity ((238)U, (232)Th and (40)K) and mineralogical characterization of Vaigai River sediments have been analyzed with the view of evaluating the radiation risk and its relation to available minerals. Different radiological parameters are calculated to know the entire radiological characterization. The average of activity concentrations and all radiological parameters are lower than the recommended safety limit. However, some sites are having higher radioactivity values than the safety limit. From the FTIR spectroscopic technique, the minerals such as quartz, microcline feldspar, orthoclase feldspar, kaolinite, gibbsite, calcite, montmorillonite and organic carbon are identified and they are characterized. The extinction co-efficient values are calculated to know the relative distribution of major minerals such as quartz, microcline feldspar, orthoclase feldspar and kaolinite. The calculated values indicate that the amount of quartz is higher than orthoclase feldspar, microcline feldspar and much higher than kaolinite. Crystallinity index is calculated to know the crystalline nature of quartz and the result indicates that the presence of ordered crystalline quartz in the present sediment. The role of minerals in the level of radioactivity is assessed by multivariate statistical analysis (Pearson's correlation and Cluster analysis). The statistical analysis confirms that the clay mineral kaolinite is the major factor than other major minerals to induce the important radioactivity variables such as absorbed dose rate and concentrations of (232)Th and (238)U. Copyright © 2013 Elsevier B.V. All rights reserved.

Optical absorption, TL and IRSL of basic plagioclase megacrysts from the Pinacate (Sonora (Mexico)) quaternary alkalic volcanics

International Nuclear Information System (INIS)

Chernov, V.; Paz-Moreno, F.; Piters, T. M.; Barboza-Flores, M.

2006-01-01

The paper presents the first results of an investigation on optical absorption (OA), thermally and infrared stimulated luminescence (TL and IRSL) of the Pinacate plagioclase (labradorite). The OA spectra reveal two bands with maxima at 1.0 and 3.2 eV connected with absorption of the Fe 3+ and Fe 2+ and IR absorption at wavelengths longer than 2700 nm. The ultraviolet absorption varies exponentially with the photon energy following the 'vitreous' empirical Urbach rule indicating exponential distribution of localised states in the forbidden band. The natural TL is peaked at 700 K. Laboratory beta irradiation creates a very broad TL peak with maximum at 430 K. The change of the 430 K TL peak shape under the thermal cleaning procedure and dark storage after irradiation reveals a monotonous increasing of the activation energy that can be explained by the exponential distribution of traps. The IRSL response is weak and exhibits a typical decay behaviour. (authors)

Optical absorption, TL and IRSL of basic plagioclase megacrysts from the pinacate (Sonora, Mexico) quaternary alkalic volcanics.

Science.gov (United States)

Chernov, V; Paz-Moreno, F; Piters, T M; Barboza-Flores, M

2006-01-01

The paper presents the first results of an investigation on optical absorption (OA), thermally and infrared stimulated luminescence (TL and IRSL) of the Pinacate plagioclase (labradorite). The OA spectra reveal two bands with maxima at 1.0 and 3.2 eV connected with absorption of the Fe3+ and Fe2+ and IR absorption at wavelengths longer than 2700 nm. The ultraviolet absorption varies exponentially with the photon energy following the 'vitreous' empirical Urbach rule indicating exponential distribution of localised states in the forbidden band. The natural TL is peaked at 700 K. Laboratory beta irradiation creates a very broad TL peak with maximum at 430 K. The change of the 430 K TL peak shape under the thermal cleaning procedure and dark storage after irradiation reveals a monotonous increasing of the activation energy that can be explained by the exponential distribution of traps. The IRSL response is weak and exhibits a typical decay behaviour.

Mechanism of adsorption of cations onto rocks

International Nuclear Information System (INIS)

Kitamura, Akira; Yamamoto, Tadashi; Fujiwara, Kenso; Nishikawa, Sataro; Moriyama, Hirotake

1999-01-01

Adsorption behavior of cations onto granite was investigated. The distribution coefficient (K d ) of Sr 2+ and Ba 2+ onto granite was determined in the solution of which pH was ranged from 3.5 to 11.3 and ionic strength was set at 10 -2 and 10 -1 . The K d values were found to increase with increasing pH and with deceasing ionic strength. The obtained data were successfully analyzed by applying an electrical double layer model. The optimum parameter values of the double layer electrostatics and adsorption reactions were obtained, and the mechanism of adsorption of cations onto granite was discussed. Feldspar was found to play an important role in their adsorption. (author)

The system K2NbF7-K2TiF6-KCl

International Nuclear Information System (INIS)

Kamenskaya, L.A.; Matveev, A.M.

1984-01-01

Using visual-polythermal and thermographical methods the ternary system K 2 NbF 7 -K 2 TiE 6 -KCl has been studied. Crystallization fields of initial components and the field of solid solutions of double compounds K 3 NbClF 7 and K 3 TiClF 6 are outlined. Ternary eutectics at 654 deg C, having the composition K 2 NbF 6 -41, K 2 TiP 6 -41, KCl-18 mol.%, is determined. Potassium fluoroniobate and fluorotitanate form continuous solid solutions unstable in the presence of the third component, potassium chloride

Minimum distance determination between consecutive carriers in the gamma irradiator IR-200 K trajectory

International Nuclear Information System (INIS)

Achmad Suntoro

2014-01-01

A design to determine the minimum distance between the consecutive carriers at the trajectory of gamma irradiators IR-200K is implemented. Equilibrium between centrifugal force of a moving carrier in circular trajectory and its gravity force as well as carrier dimensions are used as parameters in determining such a minimum distance. The minimum distance between the consecutive carriers in the design is defined 1.2 meters. The distance is 11.5% greater than the minimum distance theoretically calculated, namely 1,076 meters. Errors tolerance in construction/installation of the trajectory and other unexpected things during irradiator's operation are part of the consideration to enlarge the minimum distance from its theoretical value. The distance between the consecutive carriers will not affect throughput and efficiency of using radiation due to the straight trajectory segments do not need to follow such the minimum distance between the carriers, as the trajectory segments around the i radiation sources are straight. (author)

Cation distribution in a Fe-bearing K-feldspar from Itrongay,Madagascar. A combined neutron- and X-ray single crystal diffractionstudy

Energy Technology Data Exchange (ETDEWEB)

Ackermann, Sonia; Kunz, Martin; Armbruster, Thomas; Schefer,Jurg; Hanni, Henry

2005-05-02

We determined the cation distribution and ordering of Si, Al and Fe on the tetrahedral sites of a monoclinic low-sanidine from Itrongay, Madagascar, by combined neutron- and X-ray single-crystal diffraction. The cation distribution was determined by means of a simultaneous refinement using neutron- and X-ray data, as well as by combining scattering densities obtained from separate refinements with chemical data from a microprobe experiment. The two methods give the same results and show that Fe is fully ordered on T1, whereas Al shows a high degree of disorder. Based on this and previously published temperature-dependent X-ray data, we conclude that it is preferential ordering of Fe on T1 even at high temperature, rather than a high diffusion kinetics of Fe, which causes this asymmetry in ordering behavior between Al and Fe. The preferential ordering of Fe3+ relative to Al3+ in T1 is consistent with its 25 percent larger ionic radius.

K2-99

DEFF Research Database (Denmark)

Smith, A. M. S.; Gandolfi, D.; Barragan, O.

2017-01-01

We report the discovery from K2 of a transiting planet in an 18.25-d, eccentric (0.19 +/- 0.04) orbit around K2-99, an 11th magnitude subgiant in Virgo. We confirm the planetary nature of the companion with radial velocities, and determine that the star is a metal-rich ([ Fe/H] = 0.20 +/- 0...

Crossed molecular beam-tunable laser determination of velocity dependence of intramultiplet mixing: K(4p2P1/2)+He →K(4p2P3/2)+He

International Nuclear Information System (INIS)

Anderson, R.W.; Goddard, T.P.; Parravano, C.; Warner, J.

1976-01-01

The velocity dependence of intramultiplet mixing, K(4p 2 P 1 / 2 ) +He→K(4p 2 P 3 / 2 )+He, has been measured over the relative velocity range v=1.3--3.4 km/sec. The cross section appears to fit a linear function Q (v) =A (v-v 0 ), where a=6.3 x 10 -4 A 2 and v 0 = 7.9 x 10 4 cm/sec. The value of A is obtained by normalization to the literature thermal average cross section. The intramultiplet mixing theory of Nikitin is modified to yield Q (v) for the process. The modified theory correctly exhibits detailed balancing, and it is normalized to provide a very good fit to the observed Q (v). The magnitude of the normalization factor, however, is larger than that predicted from recent pseudopotential calculations of the excited state potentials. The temperature dependence of intramultiplet mixing is predicted. The use of laser polarization to determine the m/subj/ dependence of the process K(4p 2 P 3 / 2 +He→K(4p 2 P 1 / 2 )+He and other collision processes of excited 2 P 3 / 2 states is examined

K concentration in seven rice varieties and two infusions (coffee and tea) determined by 40K-40Ar radioactive decay

International Nuclear Information System (INIS)

Navarrete, J.M.; Cabrera, L.; Martinez, T.

2005-01-01

As a result of the event occurred in Mexico about 20 years ago, by which milk powder contaminated with 137 CS was imported from an European country after the Chernobyl accident, a legal disposition was set up in the country in order to certify the absence of radioactive contamination by gamma emitters, performing gamma spectroscopy to every foodstuff sample either imported or to be exported. In this process is always detected the X rays (1461 KeV) natural radiation emitted by 11% of 40 K nucleus decaying to 40 Ar by EC. So, when the counts accumulated during a detection time from 12 to 24 hours in a low background scintillation detection system are expressed as cps, corrected for background and divided by the sample weight (g), detection efficiency (%), decay yielding (0.11) and constant specific activity of elementary K(31.19 Bq/gK), the K concentration in the sample .is obtained. This paper reports the results found in seven rice varieties and two more vegetables, coffee and tea, including the K fractions passing to infusions, as well as are discussed similarities and differences related to K concentration and the advantages of the method.

The Electrogenic Na+/K+ Pump Is a Key Determinant of Repolarization Abnormality Susceptibility in Human Ventricular Cardiomyocytes: A Population-Based Simulation Study.

Science.gov (United States)

Britton, Oliver J; Bueno-Orovio, Alfonso; Virág, László; Varró, András; Rodriguez, Blanca

2017-01-01

Background: Cellular repolarization abnormalities occur unpredictably due to disease and drug effects, and can occur even in cardiomyocytes that exhibit normal action potentials (AP) under control conditions. Variability in ion channel densities may explain differences in this susceptibility to repolarization abnormalities. Here, we quantify the importance of key ionic mechanisms determining repolarization abnormalities following ionic block in human cardiomyocytes yielding normal APs under control conditions. Methods and Results: Sixty two AP recordings from non-diseased human heart preparations were used to construct a population of human ventricular models with normal APs and a wide range of ion channel densities. Multichannel ionic block was applied to investigate susceptibility to repolarization abnormalities. I Kr block was necessary for the development of repolarization abnormalities. Models that developed repolarization abnormalities over the widest range of blocks possessed low Na + /K + pump conductance below 50% of baseline, and I CaL conductance above 70% of baseline. Furthermore, I NaK made the second largest contribution to repolarizing current in control simulations and the largest contribution under 75% I Kr block. Reversing intracellular Na + overload caused by reduced I NaK was not sufficient to prevent abnormalities in models with low Na + /K + pump conductance, while returning Na + /K + pump conductance to normal substantially reduced abnormality occurrence, indicating I NaK is an important repolarization current. Conclusions: I NaK is an important determinant of repolarization abnormality susceptibility in human ventricular cardiomyocytes, through its contribution to repolarization current rather than homeostasis. While we found I Kr block to be necessary for repolarization abnormalities to occur, I NaK decrease, as in disease, may amplify the pro-arrhythmic risk of drug-induced I Kr block in humans.

Nitrogen in biogenic and abiogenic minerals from Paleozoic black shales: an NRA study

International Nuclear Information System (INIS)

Gallien, J.-P.; Orberger, B.; Daudin, L.; Pinti, D.L.; Pasava, J.

2004-01-01

Nuclear reaction analyses were performed on feldspars, quartz, abiogenic and biogenic sulfides and phosphates in organic matter-rich black shales. The goal was to study N-fractionation in black shales during diagenesis and contemporaneous hydrothermalism. Light elements (N, C) together with heavier ones (K, Ca, Ni, Fe, Zn) were analyzed by PIXE. Due to the heterogeneous sample composition, a scanning mode was used. Each phase was identified before extracting the corresponding spectra for quantification. Six phases, carrying nitrogen (and C), have been identified. K-feldspars are the richest in N (1.0-2.4 wt.%), followed by organic carbon (0.67 wt.%). Quartz, biogenic and abiogenic sulfides and phosphates contain N in the range of 0.56-1.08 wt.%. The present N-distribution in the black shales is explained by a two-step nitrogen release: (1) organic matter decay produces N, P, S nutriments for the development of a hydrothermal vent fauna and (2) biomineralization of this vent fauna liberates nitrogen to early diagenetic fluids. The extreme N enrichment of feldspars is related to its crystal structure, favoring the potassium substitution by NH 4 + , and the N-uptake during organic matter replacement

Diagenesis of Permian alluvial fan deposits of Northern Switzerland

International Nuclear Information System (INIS)

Bluem, W.

1987-01-01

Fine-grained sandstones of Permian alluvial fan deposits from three Nagra boreholes (Weiach, Riniken, Kaisten) and an exploration well, drilled at Wintersingen are clast supported, moderately sorted arkosic greywackes containing typically 2-20 % clayey matrix. Petrographic studies indicate that the origin of this clayey matrix is postdepositional. Mechanical infiltration of fines and diagenetic reddening of detrital and authigenic iron oxides are the earliest recorded events. Additionally, nodular calcites of calcrete origin and fibrous illitic clays are also ascribed to the eogenetic environment. The present strong compaction fabric results from general lack of eogenetic framework supporting cements. During mesogenesis, secondary porosity was generated through partial removal of early calcite. At the same time, a first generation of syntaxial quartz cementation and a subsequent fibrous illite authigenesis took place. Leaching of detrital K-feldspars post-dating compaction is recorded throughout the studied boreholes. The following burial diagenetic events differ between the various boreholes: in Weiach and Wintersingen kaolinite, illite, prismatic quartz and ankerite/siderite are recorded; in Riniken K-feldspar, illite, prismatic quartz and dolomite developed; whilst in Kaisten K-feldspar and microcrystalline quartz-cement dominate. These differences reflect the chemistry, pH and ionic strength of the pore fluids. Filling of veins by dolomite/ankerite, iron-rich and subsequent iron-poor calcite is the latest recorded event. (author) 21 refs., 10 figs., 1 tab

Measurement of $CP$ asymmetry in $D^0\\rightarrow K^-K^+$ decays

CERN Document Server

Aaij, Roel; Adinolfi, Marco; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Andreassi, Guido; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Archilli, Flavio; d'Argent, Philippe; Arnau Romeu, Joan; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Babuschkin, Igor; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baker, Sophie; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Baszczyk, Mateusz; Batozskaya, Varvara; Batsukh, Baasansuren; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Bel, Lennaert; Bellee, Violaine; Belloli, Nicoletta; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bertolin, Alessandro; Betti, Federico; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bezshyiko, Iaroslava; Bifani, Simone; Billoir, Pierre; Bird, Thomas; Birnkraut, Alex; Bitadze, Alexander; Bizzeti, Andrea; Blake, Thomas; Blanc, Frederic; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Boettcher, Thomas; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borgheresi, Alessio; Borghi, Silvia; Borisyak, Maxim; Borsato, Martino; Bossu, Francesco; Boubdir, Meriem; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Braun, Svende; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Buchanan, Emma; Burr, Christopher; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Camboni, Alessandro; Campana, Pierluigi; Campora Perez, Daniel; Campora Perez, Daniel Hugo; Capriotti, Lorenzo; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carniti, Paolo; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cavallero, Giovanni; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chatzikonstantinidis, Georgios; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chobanova, Veronika; Chrzaszcz, Marcin; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Costa Sobral, Cayo Mar; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Da Cunha Marinho, Franciole; Dall'Occo, Elena; Dalseno, Jeremy; David, Pieter; Davis, Adam; De Aguiar Francisco, Oscar; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Serio, Marilisa; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Demmer, Moritz; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Dey, Biplab; Di Canto, Angelo; Dijkstra, Hans; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dovbnya, Anatoliy; Dreimanis, Karlis; Dufour, Laurent; Dujany, Giulio; Dungs, Kevin; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Déléage, Nicolas; Easo, Sajan; Ebert, Marcus; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Farley, Nathanael; Farry, Stephen; Fay, Robert; Fazzini, Davide; Ferguson, Dianne; Fernandez Albor, Victor; Fernandez Prieto, Antonio; Ferrari, Fabio; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fini, Rosa Anna; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fleuret, Frederic; Fohl, Klaus; Fontana, Marianna; Fontanelli, Flavio; Forshaw, Dean Charles; Forty, Roger; Franco Lima, Vinicius; Frank, Markus; Frei, Christoph; Fu, Jinlin; Furfaro, Emiliano; Färber, Christian; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; Garcia Martin, Luis Miguel; García Pardiñas, Julián; Garra Tico, Jordi; Garrido, Lluis; Garsed, Philip John; Gascon, David; Gaspar, Clara; Gavardi, Laura; Gazzoni, Giulio; Gerick, David; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianì, Sebastiana; Gibson, Valerie; Girard, Olivier Göran; Giubega, Lavinia-Helena; Gizdov, Konstantin; Gligorov, V.V.; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gorelov, Igor Vladimirovich; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Griffith, Peter; Grillo, Lucia; Gruberg Cazon, Barak Raimond; Grünberg, Oliver; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Göbel, Carla; Hadavizadeh, Thomas; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; Hatch, Mark; He, Jibo; Head, Timothy; Heister, Arno; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hombach, Christoph; Hopchev, P H; Hulsbergen, Wouter; Humair, Thibaud; Hushchyn, Mikhail; Hussain, Nazim; Hutchcroft, David; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jawahery, Abolhassan; Jiang, Feng; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Kariuki, James Mwangi; Karodia, Sarah; Kecke, Matthieu; Kelsey, Matthew; Kenyon, Ian; Kenzie, Matthew; Ketel, Tjeerd; Khairullin, Egor; Khanji, Basem; Khurewathanakul, Chitsanu; Kirn, Thomas; Klaver, Suzanne; Klimaszewski, Konrad; Koliiev, Serhii; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Kozachuk, Anastasiia; Kozeiha, Mohamad; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krokovny, Pavel; Kruse, Florian; Krzemien, Wojciech; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kuonen, Axel Kevin; Kurek, Krzysztof; Kvaratskheliya, Tengiz; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lanfranchi, Gaia; Langenbruch, Christoph; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Leflat, Alexander; Lefrançois, Jacques; Lefèvre, Regis; Lemaitre, Florian; Lemos Cid, Edgar; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Liu, Xuesong; Loh, David; Longstaff, Iain; Lopes, Jose; Lucchesi, Donatella; Lucio Martinez, Miriam; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Lusiani, Alberto; Lyu, Xiao-Rui; Machefert, Frederic; Maciuc, Florin; Maev, Oleg; Maguire, Kevin; Malde, Sneha; Malinin, Alexander; Maltsev, Timofei; Manca, Giulia; Mancinelli, Giampiero; Manning, Peter Michael; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Marks, Jörg; Martellotti, Giuseppe; Martin, Morgan; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massacrier, Laure Marie; Massafferri, André; Matev, Rosen; Mathad, Abhijit; Mathe, Zoltan; Matteuzzi, Clara; Mauri, Andrea; Maurin, Brice; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; Meadows, Brian; Meier, Frank; Meissner, Marco; Melnychuk, Dmytro; Merk, Marcel; Merli, Andrea; Michielin, Emanuele; Milanes, Diego Alejandro; Minard, Marie-Noelle; Mitzel, Dominik Stefan; Mogini, Andrea; Molina Rodriguez, Josue; Monroy, Ignacio Alberto; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Mulder, Mick; Mussini, Manuel; Müller, Dominik; Müller, Janine; Müller, Katharina; Müller, Vanessa; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nandi, Anita; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen-Mau, Chung; Nieswand, Simon; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Ogilvy, Stephen; Oldeman, Rudolf; Onderwater, Gerco; Otalora Goicochea, Juan Martin; Otto, Adam; Owen, Patrick; Oyanguren, Maria Aranzazu; Pais, Preema Rennee; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parker, William; Parkes, Christopher; Passaleva, Giovanni; Pastore, Alessandra; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Pescatore, Luca; Petridis, Konstantinos; Petrolini, Alessandro; Petrov, Aleksandr; Petruzzo, Marco; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pikies, Malgorzata; Pinci, Davide; Pistone, Alessandro; Piucci, Alessio; Playfer, Stephen; Plo Casasus, Maximo; Poikela, Tuomas; Polci, Francesco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Pomery, Gabriela Johanna; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Poslavskii, Stanislav; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Quagliani, Renato; Rachwal, Bartolomiej; Rademacker, Jonas; Rama, Matteo; Ramos Pernas, Miguel; Rangel, Murilo; Raniuk, Iurii; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; dos Reis, Alberto; Remon Alepuz, Clara; Renaudin, Victor; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vicente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Lopez, Jairo Alexis; Rodriguez Perez, Pablo; Rogozhnikov, Alexey; Roiser, Stefan; Rollings, Alexandra Paige; Romanovskiy, Vladimir; Romero Vidal, Antonio; Ronayne, John William; Rotondo, Marcello; Rudolph, Matthew Scott; Ruf, Thomas; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sadykhov, Elnur; Sagidova, Naylya; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santimaria, Marco; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schael, Stefan; Schellenberg, Margarete; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmelzer, Timon; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schubert, Konstantin; Schubiger, Maxime; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sergi, Antonino; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Siddi, Benedetto Gianluca; Silva Coutinho, Rafael; Silva de Oliveira, Luiz Gustavo; Simi, Gabriele; Simone, Saverio; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Eluned; Smith, Iwan Thomas; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Souza De Paula, Bruno; Spaan, Bernhard; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Stefko, Pavol; Stefkova, Slavorima; Steinkamp, Olaf; Stemmle, Simon; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Syropoulos, Vasileios; Szczekowski, Marek; Szumlak, Tomasz; T'Jampens, Stephane; Tayduganov, Andrey; Tekampe, Tobias; Tellarini, Giulia; Teubert, Frederic; Thomas, Eric; van Tilburg, Jeroen; Tilley, Matthew James; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Toriello, Francis; Tournefier, Edwige; Tourneur, Stephane; Trabelsi, Karim; Traill, Murdo; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tully, Alison; Tuning, Niels; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valassi, Andrea; Valat, Sebastien; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vecchi, Stefania; van Veghel, Maarten; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Venkateswaran, Aravindhan; Vernet, Maxime; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Volkov, Vladimir; Vollhardt, Achim; Voneki, Balazs; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Vázquez Sierra, Carlos; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wang, Jianchun; Ward, David; Wark, Heather Mckenzie; Watson, Nigel; Websdale, David; Weiden, Andreas; Whitehead, Mark; Wicht, Jean; Wilkinson, Guy; Wilkinson, Michael; Williams, Mark Richard James; Williams, Matthew; Williams, Mike; Williams, Timothy; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wraight, Kenneth; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yin, Hang; Yu, Jiesheng; Yuan, Xuhao; Yushchenko, Oleg; Zarebski, Kristian Alexander; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Yanxi; Zhang, Yu; Zhelezov, Alexey; Zheng, Yangheng; Zhokhov, Anatoly; Zhu, Xianglei; Zhukov, Valery; Zucchelli, Stefano

2017-04-10

A measurement of the time-integrated $CP$ asymmetry in the Cabibbo-suppressed decay $D^0\\rightarrow K^-K^+$ is performed using pp collision data, corresponding to an integrated luminosity of 3fb$^-1$, collected with the LHCb detector at centre-of-mass energies of 7 and 8 TeV. The flavour of the charm meson at production is determined from the charge of the pion in $D^{*+}\\rightarrow D^0 \\pi^+$ and $D^{*-}\\rightarrow \\bar{D^0} \\pi^-$ decays. The time-integrated $CP$ asymmetry $A_{CP}(K^-K^+)$ is obtained assuming negligible $CP$ violation in charm mixing and in Cabibbo-favoured $D^0\\rightarrow K^-\\pi^+$, $D^+\\rightarrow K^-\\pi^+\\pi^+$ and $D^+\\rightarrow \\bar{K^0}\\pi^+$ decays used as calibration channels. It is found to be $A_{CP}(K^-K^+)=(0.14\\pm0.15(stat)\\pm0.10(syst))\\%$. A combination of this result with previous LHCb measurements yields $A_{CP}(K^-K^+)=(0.04\\pm0.12(stat)\\pm0.10(syst))\\%$, $A_{CP}(\\pi^-\\pi^+)=(0.07\\pm0.14(stat)\\pm0.11(syst))\\%$. These are the most precise measurements from a single experi...

Determination of microelements in thyroids of the inhabitants of Belarus by neutron activation analysis using the k0-method

International Nuclear Information System (INIS)

Boulyga, S.F.; Zhuk, I.V.; Lomonosova, E.M.; Kievetz, M.K.; Denschlag, H.O.; Zauner, S.

1997-01-01

The 'k 0 -method' of neutron activation analysis has been tested for applicability to the determination of trace elements in samples of thyroids of inhabitants from regions in Belarus affected to different degree by thyroid cancer among children after the accident of the Chernobyl power plant. It is shown that the k 0 -method produces results identical to the 'relative method' in neutron activation analysis. Significant differences in the elemental composition of thyroids from the regions of Gomel and Minsk are observed and may be related to the different levels of occurrence of thyroid cancer among children. (author)

Determining the Number of Instars in Simulium quinquestriatum (Diptera: Simuliidae) Using k-Means Clustering via the Canberra Distance.

Science.gov (United States)

Yang, Yao Ming; Jia, Ruo; Xun, Hui; Yang, Jie; Chen, Qiang; Zeng, Xiang Guang; Yang, Ming

2018-02-21

Simulium quinquestriatum Shiraki (Diptera: Simuliidae), a human-biting fly that is distributed widely across Asia, is a vector for multiple pathogens. However, the larval development of this species is poorly understood. In this study, we determined the number of instars in this pest using three batches of field-collected larvae from Guiyang, Guizhou, China. The postgenal length, head capsule width, mandibular phragma length, and body length of 773 individuals were measured, and k-means clustering was used for instar grouping. Four distance measures-Manhattan, Euclidean, Chebyshev, and Canberra-were determined. The reported instar numbers, ranging from 4 to 11, were set as initial cluster centers for k-means clustering. The Canberra distance yielded reliable instar grouping, which was consistent with the first instar, as characterized by egg bursters and prepupae with dark histoblasts. Females and males of the last cluster of larvae were identified using Feulgen-stained gonads. Morphometric differences between the two sexes were not significant. Validation was performed using the Brooks-Dyar and Crosby rules, revealing that the larval stage of S. quinquestriatum is composed of eight instars.

Differentiating pedogenesis from diagenesis in early terrestrial paleoweathering surfaces formed on granitic composition parent materials

Science.gov (United States)

Driese, S.G.; Medaris, L.G.; Ren, M.; Runkel, Anthony C.; Langford, R.P.

2007-01-01

Unconformable surfaces separating Precambrian crystalline basement and overlying Proterozoic to Cambrian sedimentary rocks provide an exceptional opportunity to examine the role of primitive soil ecosystems in weathering and resultant formation of saprolite (weathered rock retaining rock structure) and regolith (weathered rock without rock structure), but many appear to have been affected by burial diagenesis and hydrothermal fluid flow, leading some researchers to discount their suitability for such studies. We examine one modern weathering profile (Cecil series), four Cambrian paleoweathering profiles from the North American craton (Squaw Creek, Franklin Mountains, Core SQ-8, and Core 4), one Neoproterozoic profile (Sheigra), and one late Paleoproterozoic profile (Baraboo), to test the hypothesis that these paleoweathering profiles do provide evidence of primitive terrestrial weathering despite their diagenetic and hydrothermal overprinting, especially additions of potassium. We employ an integrated approach using (1) detailed thin-section investigations to identify characteristic pedogenic features associated with saprolitization and formation of well-drained regoliths, (2) electron microprobe analysis to identify specific weathered and new mineral phases, and (3) geochemical mass balance techniques to characterize volume changes during weathering and elemental gains and losses of major and minor elements relative to the inferred parent materials. There is strong pedogenic evidence of paleoweathering, such as clay illuviation, sepic-plasmic fabrics, redoximorphic features, and dissolution and alteration of feldspars and mafic minerals to kaolinite, gibbsite, and Fe oxides, as well as geochemical evidence, such as whole-rock losses of Na, Ca, Mg, Si, Sr, Fe, and Mn greater than in modern profiles. Evidence of diagenesis includes net additions of K, Ba, and Rb determined through geochemical mass balance, K-feldspar overgrowths in overlying sandstone sections, and

The Segue K giant survey. II. A catalog of distance determinations for the Segue K giants in the galactic halo

International Nuclear Information System (INIS)

Xue, Xiang-Xiang; Rix, Hans-Walter; Ma, Zhibo; Morrison, Heather L.; Harding, Paul; Beers, Timothy C.; Ivans, Inese I.; Jacobson, Heather R.; Johnson, Jennifer; Lee, Young Sun; Lucatello, Sara; Rockosi, Constance M.; Sobeck, Jennifer S.; Yanny, Brian; Zhao, Gang; Allende Prieto, Carlos

2014-01-01

We present an online catalog of distance determinations for 6036 K giants, most of which are members of the Milky Way's stellar halo. Their medium-resolution spectra from the Sloan Digital Sky Survey/Sloan Extension for Galactic Understanding and Exploration are used to derive metallicities and rough gravity estimates, along with radial velocities. Distance moduli are derived from a comparison of each star's apparent magnitude with the absolute magnitude of empirically calibrated color-luminosity fiducials, at the observed (g – r) 0 color and spectroscopic [Fe/H]. We employ a probabilistic approach that makes it straightforward to properly propagate the errors in metallicities, magnitudes, and colors into distance uncertainties. We also fold in prior information about the giant-branch luminosity function and the different metallicity distributions of the SEGUE K-giant targeting sub-categories. We show that the metallicity prior plays a small role in the distance estimates, but that neglecting the luminosity prior could lead to a systematic distance modulus bias of up to 0.25 mag, compared to the case of using the luminosity prior. We find a median distance precision of 16%, with distance estimates most precise for the least metal-poor stars near the tip of the red giant branch. The precision and accuracy of our distance estimates are validated with observations of globular and open clusters. The stars in our catalog are up to 125 kpc from the Galactic center, with 283 stars beyond 50 kpc, forming the largest available spectroscopic sample of distant tracers in the Galactic halo.

Amplitude analysis of $D^0\\rightarrow K^+K^-\\pi^+\\pi^-$ and its subsequent use in measuring the CKM phase $\\gamma$ through $B^{\\pm}\\rightarrow D(\\rightarrow K^+K^-\\pi^+\\pi^-)K^{\\pm}$ decays at LHCb

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00392618

An amplitude analysis of the 4-body charmed decay $D^0\\rightarrow K^+K^-\\pi^+\\pi^-$ has been performed using data collected from symmetric electron-positron collisions at the CLEO experiment. Both flavour tagged and CP tagged data are utilised in the analysis, making it unique among amplitude analyses performed at other experiments and providing extra sensitivity to the phases of the amplitude components. This analysis uses a data driven regularisation method to determine which of the multitude of possible amplitude components to include in the amplitude model. The dominant contributions are found to be $D^0 \\to \\phi(1020) \\, \\rho^0(770)$, $D^0 \\to K^- \\, K_{1}(1270)^{+}$ and $D^0 \\to K^- \\, K_{1}(1400)^{+}$. Tests for CP violation in the $D$ system are performed using the amplitude model; no evidence for CP violation is found. The amplitude model obtained is crucial input for a model-dependent measurement of the CP-violating phase $\\gamma$ using $B^\\pm \\to D(\\to K^+K^-\\pi^+\\pi^-)K^\\pm$ decays, which remains...

Search for the Theta+ pentaquark in the reactions gammap-->[overline K]0K+n and gammap-->[overline K]0K0p

Energy Technology Data Exchange (ETDEWEB)

Raffaella De Vita; Marco Battaglieri; V. Kubarovsky; Nathan Baltzell; Matthew Bellis; John Goett; Lei Guo; Gordon Mutchler; Paul Stoler; Maurizio Ungaro; Dennis Weygand; Moscov Amaryan; Pawel Ambrozewicz; Marco Anghinolfi; Gegham Asryan; Harutyun AVAKIAN; Harutyun Avakian; Hovhannes Baghdasaryan; Nathan Baillie; Jacques Ball; Vitaly Baturin; Ivan Bedlinski; Ivan Bedlinskiy; Nawal Benmouna; Barry Berman; Angela Biselli; Sergey Boyarinov; Sylvain Bouchigny; Robert Bradford; Derek Branford; William Briscoe; William Brooks; Stephen Bueltmann; Volker Burkert; Cornel Butuceanu; John Calarco; Sharon Careccia; Daniel Carman; Shifeng Chen; Eric Clinton; Philip Cole; Patrick Collins; Philip Coltharp; Donald Crabb; Hall Crannell; Volker Crede; John Cummings; D. Dale; Raffaella De Vita; Enzo De Sanctis; Pavel Degtiarenko; Alexandre Deur; Kahanawita Dharmawardane; Chaden Djalali; Gail Dodge; Joseph Donnelly; David Doughty; Michael Dugger; Oleksandr Dzyubak; Hovanes Egiyan; Kim Egiyan; Lamiaa Elfassi; Latifa Elouadrhiri; Paul Eugenio; Gleb Fedotov; Herbert Funsten; Marianna Gabrielyan; Liping Gan; Michel Garcon; Ashot Gasparian; Gagik Gavalian; Gerard Gilfoyle; Kevin Giovanetti; Francois-Xavier Girod; Oleksandr Glamazdin; John Goetz; Evgueni Golovatch; Atilla Gonenc; Christopher Gordon; Ralf Gothe; Keith Griffioen; Michel Guidal; Nevzat Guler; Harutyun Gyurjyan; Cynthia Hadjidakis; Kawtar Hafidi; Hayk Hakobyan; Rafael Hakobyan; John Hardie; F. Hersman; Kenneth Hicks; Ishaq Hleiqawi; Maurik Holtrop; Charles Hyde-Wright; Yordanka Ilieva; David Ireland; Boris Ishkhanov; Eugeny Isupov; Mark Ito; D. Jenkins; Hyon-Suk Jo; Kyungseon Joo; Henry Juengst; James Kellie; Mahbubul Khandaker; Wooyoung Kim; Andreas Klein; Franz Klein; Alexei Klimenko; Mikhail Kossov; Laird Kramer; Joachim Kuhn; Sebastian Kuhn; Sergey Kuleshov; Jeff Lachniet; Jean Laget; Jorn Langheinrich; Dave Lawrence; Tsung-shung Lee; Ji Li; K. Livingston; Haiyun Lu; Marion MacCormick; Nikolai Markov; Bryan McKinnon; Bernhard Mecking; Joseph Melone; Mac Mestayer; Curtis Meyer; Tsutomu Mibe; Konstantin Mikhaylov; Ralph Minehart; Marco Mirazita; R. Miskimen; Vasiliy Mochalov; Viktor Mokeev; Ludyvine Morand; Steven Morrow; Maryam Moteabbed; Pawel Nadel-Turonski; Itaru Nakagawa; Rakhsha Nasseripour; Silvia Niccolai; Gabriel Niculescu; Maria-Ioana Niculescu; Bogdan Niczyporuk; Megh Niroula; Rustam Niyazov; Mina Nozar; Mikhail Osipenko; Alexander Ostrovidov; Kijun Park; Evgueni Pasyuk; Craig Paterson; Joshua Pierce; Nikolay Pivnyuk; Dinko Pocanic; Oleg Pogorelko; Sergey Pozdnyakov; John Price; Yelena Prok; Dan Protopopescu; Brian Raue; Gregory Riccardi; Giovanni Ricco; Marco Ripani; Barry Ritchie; Federico Ronchetti; Guenther Rosner; Patrizia Rossi; Franck Sabatie; Carlos Salgado; Joseph Santoro; Vladimir Sapunenko; Reinhard Schumacher; Vladimir Serov; Youri Sharabian; Nikolay Shvedunov; Elton Smith; Lee Smith; Daniel Sober; Aleksey Stavinskiy; Samuel Stepanyan; Stepan Stepanyan; Burnham Stokes; Igor Strakovski; Steffen Strauch; Mauro Taiuti; David Tedeschi; Aram Teymurazyan; Ulrike Thoma; Avtandil Tkabladze; Svyatoslav Tkachenko; Luminita Todor; Clarisse Tur; Michael Vineyard; Alexander Vlassov; Daniel Watts; Lawrence Weinstein; M. Williams; Elliott Wolin; Michael Wood; Amrit Yegneswaran; Lorenzo Zana; Jixie Zhang; Bo Zhao; Zhiwen Zhao

2006-11-16

The exclusive reactions {gamma}p {yields} {bar K}{sup 0} K{sup +} n and {gamma}p {yields} {bar K}{sup 0} K{sup 0} p have been studied in the photon energy range 1.6--3.8 GeV, searching for evidence of the exotic baryon {Theta}{sup +}(1540) in the decays {Theta}{sup +} {yields} nK{sup +} and {Theta}{sup +} {yields} pK{sup 0}. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. The integrated luminosity was about 70 pb{sup -1}. The reactions have been isolated by detecting the K{sup +} and proton directly, the neutral kaon via its decay to K{sub S} {yields} {pi}{sup +}{pi}{sup -} and the neutron or neutral kaon via the missing mass technique. The mass and width of known hyperons such as {Sigma}{sup +}, {Sigma}{sup -} and {Lambda}(1116) were used as a check of the mass determination accuracy and experimental resolution. Approximately 100,000 {Lambda}*(1520)'s and 150,000 {phi}'s were observed in the {bar K}{sup 0} K{sup +} n and {bar K}{sup 0} K{sup 0} p final state respectively. No evidence for the {Theta}{sup +} pentaquark was found in the nK{sup +} or pK{sub S} invariant mass spectra. Upper limits were set on the production cross section of the reaction {gamma}p {yields} {Theta}{sup +} {bar K}{sup 0} as functions of center-of-mass angle, nK{sup +} and pK{sub S} masses. Combining the results of the two reactions, the 95% C.L. upper limit on the total cross section for a resonance peaked at 1540 MeV was found to be 0.7 nb. Within most of the available theoretical models, this corresponds to an upper limit on the {Theta}{sup +} width, {Gamma}{sub {Theta}{sup +}}, ranging between 0.01 and 7 MeV.

Decay of 36K

International Nuclear Information System (INIS)

Fritts, M.J.

1976-01-01

36 K was produced via the 36 Ar(p, n) 36 K reaction. Measurement of 27 β + delayed γ rays associated with the decay of 36 K implied 10 new β + branches to energy levels in 36 Ar. Branching ratios and logft values are calculated for the β + branches. Restrictions on spin and parity assignments for the 36 Ar levels are given, as well as branching ratios for γ transitions from these levels. The half-life of 36 K is determined to be 344 +- 3 msec

Chemical analysis of minerals in granitic rocks by electron probe micro analyser

International Nuclear Information System (INIS)

Hiraoka, Yoshihiro

1994-01-01

The chemical compositions of minerals in a few granitic rocks were determined by electron probe micro analyser (EPMA). The accurate analytical data for standard feldspar groups were obtained by correcting the low analytical values of sodium and potassium that were arised from the damage in EPMA analysis. Using this method, feldspar groups and biotites in three granitic rocks gathered from Hiei, Hira and Kurama areas respectively, were analyzed. As the results, the local characteristics were observed in the kinds of feldspar groups and the chemical compositions of biotites that were contained in granitic rocks. (author)

Keratins K2 and K10 are essential for the epidermal integrity of plantar skin.

Science.gov (United States)

Fischer, Heinz; Langbein, Lutz; Reichelt, Julia; Buchberger, Maria; Tschachler, Erwin; Eckhart, Leopold

2016-01-01

K1 and K2 are the main type II keratins in the suprabasal epidermis where each of them heterodimerizes with the type I keratin K10 to form intermediate filaments. In regions of the ears, tail, and soles of the mouse, only K2 is co-expressed with K10, suggesting that these keratins suffice to form a mechanically resilient cytoskeleton. To determine the effects of the suppression of both main keratins, K2 and K10, in the suprabasal plantar epidermis of the mouse. Krt2(-/-) Krt10(-/-) mice were generated by crossing Krt2(-/-) and Krt10(-/-) mice. Epidermal morphology of soles of hind-paws was examined macroscopically and histologically. Immunofluorescence analysis and quantitative PCR analysis were performed to analyze the expression of keratins in sole skin of wildtype and Krt2(-/-) Krt10(-/-) mice. Highly abundant proteins of the sole stratum corneum were determined by electrophoretic and chromatographic separation and subsequent mass spectrometry. K2 and K10 are the most prominent suprabasal keratins in normal mouse soles with the exception of the footpads where K1, K9 and K10 predominate. Mice lacking both K2 and K10 were viable and developed epidermal acanthosis and hyperkeratosis in inter-footpad epidermis of the soles. The expression of keratins K1, K9 and K16 was massively increased at the RNA and protein levels in the soles of Krt2(-/-) Krt10(-/-) mice. This study demonstrates that the loss of the main cytoskeletal components of plantar epidermis, i.e. K2 and K10, can be only partly compensated by the upregulation of other keratins. The thickening of the epidermis in the soles of Krt2(-/-) Krt10(-/-) mice may serve as a model for pathomechanistic aspects of palmoplantar keratoderma. Copyright © 2015. Published by Elsevier Ireland Ltd.

Analysis of the differential cross sections for the reaction pp{yields}ppK{sup +}K{sup -} in view of the K{sup +}K{sup -} interaction

Energy Technology Data Exchange (ETDEWEB)

Silarski, M.

2008-07-15

Measurements of the pp{yields}ppK{sup +}K{sup -} reaction, performed with the experiment COSY-11 at the Cooler Synchrotron COSY, show a significant difference between the obtained excitation function and theoretical expectations including pp-FSI. The discrepancy may be assigned to the influence of K{sup +}K{sup -} or K{sup -}p interaction. This interaction should manifest itself in the distributions of the differential cross section. This thesis presents an analysis of event distributions as a function of the invariant masses of two particle subsystems. In particular in the analysis two generalizations of the Dalitz plot proposed by Goldhaber and Nyborg are used. The present Investigations are based on the experimental data determined by the COSY-11 collaboration from two measurements at excess energies of Q=10 MeV and 28 MeV. The experimental distributions are compared to results of Monte Carlo simulations generated with various parameters of the K{sup +}K{sup -} and K{sup -}p interaction. The values of the K{sup +}K{sup -} scattering length, extracted from two data sets for Q=10 MeV and 28 MeV amount to: a{sub K{sup +}}{sub K{sup -}}=(11{+-}8)+i(0{+-}6) fm for Q=10 MeV, and a{sub K{sup +}}{sub K{sup -}}=(0.2{+-}0.2)+i(0.0{+-}0.5) fm for Q=28 MeV. Due to the low statistics, the extracted values have large uncertainties and are consistent with very low values of the real and imaginary part of the scattering length. (orig.)

Technical Note: Using k-means clustering to determine the number and position of isocenters in MLC-based multiple target intracranial radiosurgery.

Science.gov (United States)

Yock, Adam D; Kim, Gwe-Ya

2017-09-01

To present the k-means clustering algorithm as a tool to address treatment planning considerations characteristic of stereotactic radiosurgery using a single isocenter for multiple targets. For 30 patients treated with stereotactic radiosurgery for multiple brain metastases, the geometric centroids and radii of each met were determined from the treatment planning system. In-house software used this as well as weighted and unweighted versions of the k-means clustering algorithm to group the targets to be treated with a single isocenter, and to position each isocenter. The algorithm results were evaluated using within-cluster sum of squares as well as a minimum target coverage metric that considered the effect of target size. Both versions of the algorithm were applied to an example patient to demonstrate the prospective determination of the appropriate number and location of isocenters. Both weighted and unweighted versions of the k-means algorithm were applied successfully to determine the number and position of isocenters. Comparing the two, both the within-cluster sum of squares metric and the minimum target coverage metric resulting from the unweighted version were less than those from the weighted version. The average magnitudes of the differences were small (-0.2 cm 2 and 0.1% for the within cluster sum of squares and minimum target coverage, respectively) but statistically significant (Wilcoxon signed-rank test, P k-means clustering algorithm represented an advantage of the unweighted version for the within-cluster sum of squares metric, and an advantage of the weighted version for the minimum target coverage metric. While additional treatment planning considerations have a large influence on the final treatment plan quality, both versions of the k-means algorithm provide automatic, consistent, quantitative, and objective solutions to the tasks associated with SRS treatment planning using a single isocenter for multiple targets. © 2017 The Authors. Journal

The k0 and relative INAA methods to determine elements in entire archaeological pottery objects

International Nuclear Information System (INIS)

Bedregal, P.S.; Mendoza, P.A.; Ubillus, M.S.; Montoya, E.H.; Cohen, I.M.; Universidad Tecnologica Nacional, Buenos Aires

2014-01-01

The advantages of instrumental neutron activation analysis applied to archaeological ceramics have been enhanced through the analysis of entire objects, using both the k 0 method and the relative method, respectively, to determine the concentrations of chemical elements in aliquots of replicate objects used as comparators and in the sample object. Twenty-two chemical elements of archaeological importance were measured in mud figurines from Caral civilization (5000 year BC), irradiated inside a well-characterized radial channel facility of the nuclear research reactor at IPEN, Peru. The results showed less than 10 % of bias for most of the elements. (author)

Observation of the $B^{0}_{s}\\rightarrow J/\\psi K_{{\\rm S}}^{0} K^{\\pm} \\pi^{\\mp}$ decay

CERN Document Server

Aaij, Roel; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassen, Rolf; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Balagura, Vladislav; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Belogurov, Sergey; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Bizzeti, Andrea; Bjørnstad, Pål Marius; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brambach, Tobias; van den Brand, Johannes; Bressieux, Joël; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Brown, Henry; Bursche, Albert; Busetto, Giovanni; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Camboni, Alessandro; Campana, Pierluigi; Campora Perez, Daniel; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carranza-Mejia, Hector; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Ciba, Krzystof; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pascal; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Di Canto, Angelo; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Ferguson, Dianne; Fernandez Albor, Victor; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gaspar, Clara; Gauld, Rhorry; Gavardi, Laura; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Giani', Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, Vladimir; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gordon, Hamish; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; Hartmann, Thomas; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Hunt, Philip; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jaton, Pierre; Jawahery, Abolhassan; Jezabek, Marek; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kaballo, Michael; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Kelsey, Matthew; Kenyon, Ian; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kozlinskiy, Alexandr; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanciotti, Elisa; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leo, Sabato; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Liu, Guoming; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lopez-March, Neus; Lowdon, Peter; Lu, Haiting; Lucchesi, Donatella; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Manca, Giulia; Mancinelli, Giampiero; Manzali, Matteo; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martens, Aurelien; Martín Sánchez, Alexandra; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Moggi, Niccolò; Molina Rodriguez, Josue; Monteil, Stephane; Moran, Dermot; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Katharina; Muresan, Raluca; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Nicol, Michelle; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Oggero, Serena; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Orlandea, Marius; Otalora Goicochea, Juan Martin; Owen, Patrick; Oyanguren, Maria Arantza; Pal, Bilas Kanti; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Parkes, Christopher; Parkinson, Christopher John; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pazos Alvarez, Antonio; Pearce, Alex; Pellegrino, Antonio; Pepe Altarelli, Monica; Perazzini, Stefano; Perez Trigo, Eliseo; Perret, Pascal; Perrin-Terrin, Mathieu; Pescatore, Luca; Pesen, Erhan; Petridis, Konstantin; Petrolini, Alessandro; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poluektov, Anton; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Powell, Andrew; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Alexander; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Roa Romero, Diego; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruffini, Fabrizio; Ruiz, Hugo; Ruiz Valls, Pablo; Sabatino, Giovanni; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sapunov, Matvey; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Savrie, Mauro; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Seco, Marcos; Semennikov, Alexander; Senderowska, Katarzyna; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Anthony; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Sparkes, Ailsa; Spinella, Franco; Spradlin, Patrick; Stagni, Federico; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Subbiah, Vijay Kartik; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szilard, Daniela; Szumlak, Tomasz; T'Jampens, Stephane; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Tran, Minh Tâm; Tresch, Marco; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; Voss, Helge; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Whitehead, Mark; Wicht, Jean; Wiedner, Dirk; Wilkinson, Guy; Williams, Matthew; Williams, Mike; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wu, Suzhi; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Feng; Zhang, Liming; Zhang, Wen Chao; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang; Zvyagin, Alexander

2014-01-01

Decays of the form $B^{0}_{(s)}\\rightarrow J/\\psi K_{{\\rm S}}^{0} h^+ h^{\\left(\\prime\\right) -}$ ($h^{(\\prime)} = K, \\pi$) are searched for in proton-proton collision data corresponding to an integrated luminosity of $1.0 \\, {\\rm fb}^{-1}$ recorded with the LHCb detector. The first observation of the $B^{0}_{s}\\rightarrow J/\\psi K_{{\\rm S}}^{0} K^{\\pm} \\pi^{\\mp}$ decay is reported, with significance in excess of 10 standard deviations. The $B^{0}\\rightarrow J/\\psi K_{{\\rm S}}^{0} K^{+} K^{-}$ decay is also observed for the first time. The branching fraction of $B^{0}\\rightarrow J/\\psi K_{{\\rm S}}^{0} \\pi^{+} \\pi^{-}$ is determined, to significantly better precision than previous measurements, using $B^0 \\rightarrow J/\\psi K_{{\\rm S}}^{0}$ as a normalisation channel. Branching fractions and upper limits of the other $B^{0}_{(s)}\\rightarrow J/\\psi K_{{\\rm S}}^{0} h^+ h^{\\left(\\prime\\right) -}$ modes are determined relative to that of the $B^{0}\\rightarrow J/\\psi K_{{\\rm S}}^{0} \\pi^{+} \\pi^{-}$ decay.

Experimental determination of PVT data, critical quantities and of the equation of state for sodium up to 2600 K and 500 bar

International Nuclear Information System (INIS)

Binder, H.

1984-01-01

In the present thesis the PVT-data of fluid sodium are measured up to 2600 K and 500 bar and the vapor pressure curve is determined up to the critical point, which is found to be Tsub(c) = 2485 +- 15 K / Psub(c) = 248 +- 5 bar, rhosub(c) = 0.30 +- 0.05 g/cm 3 . The measured values are used to investigate the attractive forces of sodium theoretically. (BHO)

Petrochemistry and zircon U-Pb geochronology of granitic rocks in the Wang Nam Khiao area, Nakhon Ratchasima, Thailand: Implications for petrogenesis and tectonic setting

Science.gov (United States)

Fanka, Alongkot; Tsunogae, Toshiaki; Daorerk, Veerote; Tsutsumi, Yukiyasu; Takamura, Yusuke; Sutthirat, Chakkaphan

2018-05-01

Carboniferous biotite granite, Late Permian hornblende granite, and Triassic biotite-hornblende granite, all of which belong to the Eastern Granite Belt, expose in the Wang Nam Khiao area, Nakhon Ratchasima, northeastern Thailand. The Carboniferous biotite granite is dominated by quartz, K-feldspar, plagioclase, and biotite. The Late Permian hornblende granite contains dominant assemblages of plagioclase, quartz, K-feldspar, hornblende, and minor amount of biotite, while the Triassic biotite-hornblende granite consists of quartz, plagioclase, K-feldspar with small amounts of biotite, and hornblende. The REE patterns with steep decrease from light to heavy REE together with the LILE (e.g. K, Sr) enrichment and depletion of some particular HFSE (e.g. Nb, Ti) indicate low degree of partial melting. Mineral chemistry of biotite and hornblende in the granites reflects crystallization from hydrous calc-alkaline arc-derived magmas possibly formed by subduction. Amphibole-plagioclase thermometry and Al-in-hornblende barometry indicate that the Late Permian hornblende granite and the Triassic biotite-hornblende granite may have equilibrated at 3.0-5.8 kbar/700-820 °C and 2.0-3.2 kbar/600-750 °C, respectively, in the middle-upper crust (about 10-15 km depth). Zircon U-Pb geochronology of the Carboniferous biotite granite, Late Permian hornblende granite and Triassic biotite-hornblende granite yielded intrusion ages of 314.6-284.9 Ma, 253.4 Ma, and 237.8 Ma, respectively, which implies multiple episodes of arc-magmatism formed by Palaeo-Tethys subduction beneath Indochina Terrane during Late Carboniferous/Early Permian, Late Permian and Middle Triassic.

Toothbrushing alters the surface roughness and gloss of composite resin CAD/CAM blocks.

Science.gov (United States)

Kamonkhantikul, Krid; Arksornnukit, Mansuang; Lauvahutanon, Sasipin; Takahashi, Hidekazu

2016-01-01

This study investigated the surface roughness and gloss of composite resin CAD/CAM blocks after toothbrushing. Five composite resin blocks (Block HC, Cerasmart, Gradia Block, KZR-CAD Hybrid Resin Block, and Lava Ultimate), one hybrid ceramic (Vita Enamic), one feldspar ceramic (Vitablocs Mark II), one PMMA block (Telio CAD), and one conventional composite resin (Filtek Z350 XT) were evaluated. Surface roughness (Ra) and gloss were determined for each group of materials (n=6) after silicon carbide paper (P4000) grinding, 10k, 20k, and 40k toothbrushing cycles. One-way repeated measures ANOVA indicated significant differences in the Ra and gloss of each material except for the Ra of GRA. After 40k toothbrushing cycles, the Ra of BLO and TEL showed significant increases, while CER, KZR, ULT, and Z350 showed significant decreases. GRA, ENA, and VIT maintained their Ra. All of the materials tested, except CER, demonstrated significant decreases in gloss after 40k toothbrushing cycles.

Age determination of bottom sediments from Lake Hovsgol, Mongolia

International Nuclear Information System (INIS)

Ito, Kazumi; Nakamura, Toshio; Duller, Geoff; Hasebe, Noriko; Kashiwaya, Kenji

2013-01-01

Dating plays a key role in determining past environmental changes in lake sediments cores. The feldspar post-IR infrared stimulated luminescence (IRSL) procedure is one of the IRSL procedures and has a great potential to date older samples compared to quartz optically stimulated luminescence (OSL). In this study, the post-IR IRSL (pIRIR) procedure was applied to the polymineral fine grained sediments from Lake Khuvsgul (Hovsgol), Mongolia, and these ages were compared to 14 C ages of bulk samples from the certain depths. The pIRIR ages are always younger than 14 C ages from bulk samples, however, it was possible to construct the suitable age model based on luminescence and 14 C ages. Therefore, pIRIR 225 protocol can be contributed to estimate the sedimentation age of lake sediments as well as 14 C dating. (author)

Quantitative determination of Na+-K+-ATPase and other sarcolemmal components in muscle cells

International Nuclear Information System (INIS)

Hansen, O.; Clausen, T.

1988-01-01

A recurring problem in the characterization of plasma membrane enzymes in tissues and cells is whether the samples tested are representative for the entire population of enzyme molecules present in the starting material. Measurements of [ 3 H]-ouabain binding, enzyme activity, and maximum transport capacity all indicate that the concentration of Na + -K + pumps in mammalian skeletal muscle is high. Studies on Na + -K + -ATPase activity in isolated sarcolemma, however, generally give little or no information on total cellular enzyme concentration. Due to the low and variable enzyme recovery, such subcellular preparations may, therefore, give misleading data on factors regulating Na + -K + -ATPase in heart and skeletal muscle cells. As the same isolation and purification procedures are used for the study of other sarcolemmal components, this inadequate recovery has general implications for statements on regulatory changes in the sarcolemmal composition of muscle cells. On the other hand, complete quantification of Na + -K + -ATPase in muscle tissue can now be achieved using simple procedures and the entire material. Recent studies have shown that regulatory changes in the entire population of Na + -K + pumps in muscle can be quantified in measurements of [ 3 H]-ouabain binding, K + -activated 3-O-methylfluorescein phosphatase activity, as well as maximum ouabain suppressible Na + -K + transport capacity

Multianalytical determination of trace elements in atmospheric biomonitors by k0-INAA, ICP-MS and AAS

Science.gov (United States)

Freitas, M. C.; Pacheco, A. M. G.; Dionísio, I.; Sarmento, S.; Baptista, M. S.; Vasconcelos, M. T. S. D.; Cabral, J. P.

2006-08-01

Elemental contents of atmospheric biomonitors—epiphytic lichens and tree bark, exposed in continuous and discontinuous modes—have been assessed through k0-standardised instrumental neutron activation analysis ( k0-INAA) (two different institutions), inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS). Certified reference materials—ISE-921 (river clay), NIST-1547 (peach leaves), ICHTJ-INCT-TL-1 (tea leaves; TL-1 hereinafter) and IAEA-336 (lichen material), and nonparametric statistics—rank-order correlations (Spearman RS) and enhanced-sign tests (Wilcoxon T)—were used for analytical control and data comparison, respectively. In general, quality of procedures was deemed good, except for k0-INAA in determining Br, Cu and Na, all likely affected by high counting statistics, and/or contamination issues (the latter). Results for Cu, Ni, Pb and Sr (by both ICP-MS and AAS) revealed that, despite an outstanding correlation (asymptotic p=0.000), they could be viewed as statistically equal for Cu only: AAS tended to yield higher values for Pb and Ni, and lower ones for Sr. The comparison between ICP-MS and k0-INAA data from TUDelft, for Al, Ca, Cu, Mg, Mn, Na, Ti and V, showed an excellent correlation (as above) and random (relative) magnitude for Cu, Mg, Mn and Ti only: ICP-MS tended to yield higher values for Al, Na and V, and lower ones for Ca, whereas between k0-INAA data from TUDelft and ITN, for Br, Ca and Na, resulted in systematically higher [Br] and [Ca] variates from TUDelft, even if all corresponding data sets were found to correlate at stringent significance levels. In a few cases, though—Ca, Sr in lichens; Pb in bark—matrix effects did appear to interfere in the outcome of matched-pairs, signed-rank tests, since random hierarchy of variates could be asserted just when lichen and bark data sets were processed separately.

Determination of stability constants of K and Cs nitrate complex with dicyclohexyl-18-crown-6 and dibenzo-18-crown-6 in isopropanol aqueous solutions

International Nuclear Information System (INIS)

Myasoedova, T.G.; Ponomareva, A.V.; Zagorets, P.A.; Filippov, E.A.

1984-01-01

Total stability constants of K and Cs nitrate complexes with dicyclohexyl-18-crown-6 and dibenzo-18-crown-6 in isopropanol aqueous solutions were determined by the method of low-frequency contact conductometry. Clearly defined K/Cs selectivity is observed for the system with dibenzo-18-crown-6. It is shown that lgβ depends on permittivity of the solvent. The decrease of permittivity of isopropanol aqueous solutions results in reduction of K/Cs selectivity of DB18C6

Determination of stability constants of K and Cs nitrate complex with dicyclohexyl-18-crown-6 and dibenzo-18-crown-6 in isopropanol aqueous solutions

Energy Technology Data Exchange (ETDEWEB)

Myasoedova, T G; Ponomareva, A V; Zagorets, P A; Filippov, E A [Moskovskij Khimiko-Tekhnologicheskij Inst. (USSR)

1984-08-01

Total stability constants of K and Cs nitrate complexes with dicyclohexyl-18-crown-6 and dibenzo-18-crown-6 in isopropanol aqueous solutions were determined by the method of low-frequency contact conductometry. Clearly defined K/Cs selectivity is observed for the system with dibenzo-18-crown-6. It is shown that lg..beta.. depends on permittivity of the solvent. The decrease of permittivity of isopropanol aqueous solutions results in reduction of K/Cs selectivity of DB18C6.

K-means Clustering: Lloyd's algorithm

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. K-means Clustering: Lloyd's algorithm. Refines clusters iteratively. Cluster points using Voronoi partitioning of the centers; Centroids of the clusters determine the new centers. Bad example k = 3, n =4.

Plutonium isotopic assay of reprocessing product solutions in the KfK K-edge densitometer

International Nuclear Information System (INIS)

Eberle, H.; Ottmar, H.; Matussek, P.

1985-04-01

The KfK K-edge densiometer, designed for accurate element concentration measurements using the technique of X-ray absorptiometry at the K absorption edge, provides as an additional option the possibility to determine the isotopic composition of freshly separated plutonium from an gamma-spectrometric analysis of its self-radiation. This report describes the underlying methodology and experimental procedures for the isotopic analysis in the K-edge densitometer. The paper also presents and discusses the experimental results so far obtained from routine measurements on reprocessing product solutions. (orig.)

Determined Initial lead for South Of Isua (SOI) terrain suggests a single homogeneous source for it and possibly other archaean rocks

Science.gov (United States)

Tera, F.

2011-12-01

A Thorogenic-Uranogenic Lead Isotope Plane (TULIP), which entails plotting 206/208 (or its reverse) vs 207/208 (or its reverse), was applied to the Pb data on South of Isua (SOI) by Kamber et al., (1). When the data on 20 samples of these rocks and feldspars are plotted in pairs (each pair is a rock and its feldspar) on TULIP, they fall on 10 mixing lines that converge on a single spot (Fig. 1). This is the end member initial lead (EMIL). The 206/208 & 207/208 so determined are 0.3675 and 0.43525, respectively. From these values one calculates 207/206 = 1.1843 ± 0.0007, for EMIL. This pattern requires either: A) each pair has a singular kappa, K = 232Th/238U, different from others, or B) a pair's in situ decay Pb was homogenized in recent times. On 204/206 vs 207/206 diagram, the whole rocks of SOI define a 3.776 Ga isochron (2). From this and EMIL's 207/206, one obtains: 206/204 = 10.977, 207/204 = 12.974; and 208/204 = 29.756. This singularity of initial Pb contrasts with a deduced variability by the original authors (1). EMIL's radiogenic *(207/206) = 1.6220, gives a single-stage age = 5.9 Ga, indicating inapplicability of its evolution in one stage. Also, the μ calculated from 238U-206Pb for the single stage is different from that inferred from 235U-207Pb, confirming disqualification of this scenario. Reconciliation of the two decay schemes necessitates assumption of EMIL evolution in a minimum of two stages. Starting at 4.563 Ga, five scenarios were assumed: First stage ends and second starts at 4.55, 4.54, 4.53, 4.52 or 4.51 Ga. Second stages end at 3.776 Ga. The calculated μ1 for the first stage are 106, 59.5, 44.6, 36.3 and 30.9 respectively. For μ2 the change is limited, from 5.45 to 5.28. Only an average calculated K for both stages is possible. For the five outlined scenarios it ranges from 1.118 to 1.111. Earlier, Tera (3) observed that initial Pb of the oldest terrestrial reservoir requires evolution in two stages. There too μ1 >> μ2. Data on

Determining the neutrino mass hierarchy with INO, T2K, NOvA and reactor experiments

International Nuclear Information System (INIS)

Ghosh, Anushree; Choubey, Sandhya; Thakore, Tarak

2013-01-01

The relatively large measured value of θ 13 has opened up the possibility of determining the neutrino mass hierarchy through earth matter effects. Amongst the current accelerator experiments only NOvA has a long enough baseline to observe earth matter effects. However, even NOvA is plagued with uncertainty on the knowledge of the true value of Δ CP which drastically reduces its sensitivity to the neutrino mass hierarchy. Earth matter effects in atmospheric neutrinos on the other hand is almost independent of δ CP . The 50 kton magnetized Iron CALorimeter at the India-based Neutrino Observatory (ICAL at the rate lNO) will be observing atmospheric neutrinos. The charge identification capability of this detector gives it an edge over others for mass hierarchy determination through observation of earth matter effects. We study in detail the neutrino mass hierarchy sensitivity of the data from this experiment simulated using the Nuance based generator developed for ICAL at the rate lNO and folded with the detector resolution and efficiencies obtained by the INO collaboration from a full detector Geant based simulation. The data from ICAL at the rate lNO is then combined with simulated of T2K, NOvA Double Chooz, RENO and Daya Bay experiments and a combined sensitivity study to the mass hierarchy performed. With 10 years of ICAL at the rate lNO data combined with T2K, NOvA and reactor data, one could get 2.8σ - 5σ discovery for the neutrino mass hierarchy depending on the true value of (θ23, θ13 and δ CP . (author)

Computer code determination of tolerable accel current and voltage limits during startup of an 80 kV MFTF sustaining neutral beam source

International Nuclear Information System (INIS)

Mayhall, D.J.; Eckard, R.D.

1979-01-01

We have used a Lawrence Livermore Laboratory (LLL) version of the WOLF ion source extractor design computer code to determine tolerable accel current and voltage limits during startup of a prototype 80 kV Mirror Fusion Test Facility (MFTF) sustaining neutral beam source. Arc current limits are also estimated. The source extractor has gaps of 0.236, 0.721, and 0.155 cm. The effective ion mass is 2.77 AMU. The measured optimum accel current density is 0.266 A/cm 2 . The gradient grid electrode runs at 5/6 V/sub a/ (accel voltage). The suppressor electrode voltage is zero for V/sub a/ < 3 kV and -3 kV for V/sub a/ greater than or equal to 3 kV. The accel current density for optimum beam divergence is obtained for 1 less than or equal to V/sub a/ less than or equal to 80 kV, as are the beam divergence and emittance

Determination of 40 K in food and whole body

International Nuclear Information System (INIS)

Quintero P, E.; Alfaro L, M.M.; Valentin A, G.; Rojas M, V.P.

2007-01-01

We present the concentration of radioactivity of 40 K, in samples of some foods consumed by the population settled down in the area of influence of the Nuclear Center of Mexico, using the foods more representative of this area. We also present the concentration of this radioisotope in the human body classified by ages and sex. (Author)

Direct Determination of the Rate Coefficient for the Reaction of OH Radicals with Monoethanol Amine (MEA) from 296 to 510 K.

Science.gov (United States)

Onel, L; Blitz, M A; Seakins, P W

2012-04-05

Monoethanol amine (H2NCH2CH2OH, MEA) has been proposed for large-scale use in carbon capture and storage. We present the first absolute, temperature-dependent determination of the rate coefficient for the reaction of OH with MEA using laser flash photolysis for OH generation, monitoring OH removal by laser-induced fluorescence. The room-temperature rate coefficient is determined to be (7.61 ± 0.76) × 10(-11) cm(3) molecule(-1) s(-1), and the rate coefficient decreases by about 40% by 510 K. The temperature dependence of the rate coefficient is given by k1= (7.73 ± 0.24) × 10(-11)(T/295)(-(0.79±0.11)) cm(3) molecule(-1) s(-1). The high rate coefficient shows that gas-phase processing in the atmosphere will be competitive with uptake onto aerosols.

Resuspension of polychlorinated biphenyl-contaminated field sediment: release to the water column and determination of site-specific K DOC.

Science.gov (United States)

Friedman, Carey L; Lohmann, Rainer; Burgess, Robert M; Perron, Monique M; Cantwell, Mark G

2011-02-01

Sediments from the New Bedford Harbor (NBH) U.S. Environmental Protection Agency (U.S. EPA) Superfund site (Massachusetts, USA), contaminated with polychlorinated biphenyls (PCBs), were resuspended under different water column redox conditions: untreated, oxidative, and reductive. The partitioning of PCBs to the overlying water column was measured with polyethylene samplers and compared to partitioning without resuspension. Greater concentrations of total aqueous (freely dissolved + dissolved organic carbon (DOC)-associated) PCBs were found in all resuspended treatments for PCBs with mid-range K(OW)s, but no difference was observed in total aqueous concentrations among different redox conditions. The magnitude of increased concentrations depended on resuspension time and congener K(OW), but ranged from approximately one to eight times those found without resuspension. In a parallel study, DOC was flocculated and removed from smaller-scale NBH sediment resuspensions. In situ K(DOC)s were determined and used to calculate freely dissolved and DOC-associated fractions of the increase in total aqueous PCB concentrations due to resuspension. The importance of DOC-associated PCBs increased with increasing K(OW). In situ K(DOC)s were approximately one to two orders of magnitude greater than those calculated with a commonly used linear free energy relationship (LFER). The present study demonstrates that resuspension of contaminated sediments releases PCBs to the water column, of which a significant fraction are DOC-associated (e.g., 28, 65, and 90% for PCBs 28, 66, and 110, respectively). Results also imply that site-specific PCB K(DOC)s are superior to those calculated with generic LFERs. © 2010 SETAC.

Determination of trace amounts of selenium in minerals and rocks by flame less atomic-absorption spectrometry; Determinacion de selinio en minerales y rocas por espectrometria de absorcion atomica

Energy Technology Data Exchange (ETDEWEB)

Alduan, F. A.; Capdevilla, C.

1980-07-01

The determination of trace amounts of selenium In silicate rocks and feldspar by solvent extraction and graphite furnace atomic-absorption spectrometry has been stu- died. Sodium diethyl-ditio carbamate and ammonium pyrrolidine dithiocarbamate have been tried as chelating agents. The best results are achieved when selenium is extracted Into carbon tetrachloride as the sodium diethyldithiocarbamate complex. The method allows to detect 0,75 ppm of selenium in the sample. Recoveries are about 100%. (Author) 7 refs.

Arsenic K-edge X-ray absorption near-edge spectroscopy to determine oxidation states of arsenic of a coastal aquifer–aquitard system

International Nuclear Information System (INIS)

Wang, Ya; Jiao, Jiu Jimmy; Zhu, Sanyuan; Li, Yiliang

2013-01-01

Determination of oxidation states of solid-phase arsenic in bulk sediments is a valuable step in the evaluation of its bioavailability and environmental fate in deposits, but is difficult when the sediments have low arsenic contents and heterogeneous distribution of arsenic species. As K-edge X-ray absorption near-edge spectroscopy (XANES) was used to determine quantitatively the oxidation states of arsenic in sediments collected from different depths of boreholes in the Pearl River Delta, China, where the highest aquatic arsenic concentration is 161.4 μg/L, but the highest solid arsenic content only 39.6 mg/kg. The results demonstrated that XANES is efficient in determining arsenic oxidation states of the sediments with low arsenic contents and multiple arsenic species. The study on the high-resolution vertical variations of arsenic oxidation states also indicated that these states are influenced strongly by groundwater activities. With the help of geochemical data, solid arsenic speciation, toxicity and availability were further discussed. -- Highlights: •XANES is efficient in determining arsenic oxidation states of the bulk sediments. •Distribution of arsenic oxidation states is consistent with geochemical conditions. •Arsenic oxidation states are influenced strongly by groundwater activities. -- As K-edge X-ray absorption near-edge spectroscopy is efficient in determining arsenic oxidation states of the bulk sediments with low arsenic contents and heterogeneous distribution of arsenic species

Cathodoluminescence (CL Characteristics of Quartz from Different Metamorphic Rocks within the Kaoko Belt (Namibia

Directory of Open Access Journals (Sweden)

Jonathan Sittner

2018-05-01

Full Text Available Quartz of metamorphic rocks from the Kaoko belt (Namibia representing metamorphic zones from greenshist to granulite facies were investigated by cathodoluminescence (CL microscopy and spectroscopy to characterize their CL properties. The samples cover P-T conditions from the garnet zone (500 ± 30 °C, 9 ± 1 kbar up to the garnet-cordierite-sillimanite-K-feldspar zone (750 ± 30 °C, 4.0–5.5 kbar. Quartz from 10 different localities and metamorphic environments exclusively exhibits blue CL. The observed CL colors and spectra seem to be more or less independent of the metamorphic grade of the host rocks, but are determined by the regional geological conditions. Quartz from different localities of the garnet-cordierite-sillimanite-K-feldspar zone shows a dominant 450 nm emission band similar to quartz from igneous rocks, which might be related to recrystallization processes. In contrast, quartz from different metamorphic zones in the western part of the central Kaoko zone (garnet, staurolite, kyanite, and kyanite-sillimanite-muscovite zone is characterized by a heterogeneous blue-green CL and a dominant 500 nm emission band that strongly decreases in intensity under electron irradiation. Such CL characteristics are typical for quartz of pegmatitic and/or hydrothermal origin and indicate the participation of fluids during neoformation of quartz during metamorphism.

Final report on CCQM-K9.2 : subsequent key comparison on pH determination of phosphate buffer by Harned cell measurements

OpenAIRE

Spitzer, Petra; Giera, Janine; Fraga, Isabel Cristina Serta; Jakobsen, Pia Tonnes; Jensen, Hans D.; Hyllested, Peter; Karpov, Oleg; Kutovoy, Viatcheslav; Nakamura, Susumu; Vospelova, Alena; Zvezdina, Valentina

2008-01-01

CCQM-K9.2 was performed supplementary to the key comparison CCQM-K9 [1] on the pH determination of a phosphate buffer with nominal pH ~ 6.9 (at 25 °C). The sample composition was very similar in both comparisons. Only the source of the starting material used for sample preparation was different. The comparison was restricted to the use of the primary method for pH (Harned cell measurement) as defined in the IUPAC Recommendations [2]. The measurement temperatures were15 °C, 25 °C , 37...

Determination of specific activity of 226Ra, 232Th and 40K for assessment of environmental hazards

International Nuclear Information System (INIS)

Al-Haydari, A.; Al Sharabi, E. S. A.; Al Buhairi, M. H.

2012-01-01

Studies have been carried out using gamma-spectrometric techniques to determine the natural radioactivity in some rocks that are used as building materials in Yemen. The concentrations of the natural radionuclides namely 226 Ra, 232 Th and 40 K in the rock samples collected from different rock markets in Yemen have been determined using an NaI(Tl) detector. The concentrations of 226 Ra, 232 Th and 40 K in the studied rock samples range from 22.2 to 88.8 Bq kg -1 , 8.12 to 113.68 Bq kg -1 and 31.3 to 2222.3 Bq kg -1 , respectively. The concentrations of these radionuclides are compared with the typical world values. To evaluate the radiological hazard of the natural radioactivity, the radium equivalent activity, the air absorbed dose rate, the annual effective dose rate, the representative level index and the values of both external and internal hazard indices were evaluated and compared with the internationally approved values. The radium equivalent activity values of all rock samples are lower than the limit of 370 Bq kg -1 except for one sample which is about 413.386. The values of external hazard index (H ex ) and internal hazard index (H in ), absorbed doses in indoor air and the corresponding effective dose equivalents in a typical dwelling are presented. The need for further studies is also discussed. (authors)

Pore Fluid Evolution Influenced by Volcanic Activities and Related Diagenetic Processes in a Rift Basin: Evidence from the Paleogene Medium-Deep Reservoirs of Huanghekou Sag, Bohai Bay Basin, China

Directory of Open Access Journals (Sweden)

Zhongheng Sun

2017-01-01

Full Text Available Volcanic activities exert a significant influence on pore fluid property and related diagenetic processes that substantially controlled reservoirs quality. Analysis of Paleogene medium-deep sandstones on the Huanghekou Sag provides insight into relating the diagenetic processes to pore fluid property evolution influenced by volcanic activities. Three distinct types of pore fluids were identified on the basis of an integrated and systematic analysis including core and thin section observation, XRD, SEM, CL, and trace element. Alkaline aqueous medium environment occurred in E2s1+2 where volcanic activities have insignificant influence on pore fluids, evidenced by typical alkaline diagenetic events such as K-feldspar albitization, quartz dissolution, feldspar dissolution, and carbonate cementation. During the deposition of E3d3, influx of terrestrial freshwater and alteration of ferromagnesian-rich pore water result in the formation of mixing aqueous medium environment through volcanic eruption dormancy causing zeolite dissolution, clay mineral transformation, and K-feldspar albitization. Ferromagnesian-rich aqueous medium environment developed resulting from the intensive hydrolysis of the unstable ferromagnesian minerals formed due to intense volcanic activities during E3d1+2 and corresponding predominant diagenetic processes were characterized by the precipitation and dissolution of low-silica zeolites. Therefore, the differential properties of pore fluids caused various diagenetic processes controlling reservoir quality.

Determination of the cell parameters of β-quartz at 1003 K by neutron multiple diffraction

International Nuclear Information System (INIS)

Campos, Luiz Carlos de

2002-01-01

In this work, neutron multiple diffraction (NMD) data was employed for the determination of the parameters a and c of the β-quartz hexagonal cell at 1003 K. An experimental 00.1 β-quartz NMD 'Umweg' pattern has been used for the determinations. During the indexing of the β-quartz pattern it was verified that most of the peaks could be classified as either 'good for the determination of the parameter a' or 'good for the determination of the parameter c'. With such a classification, it became possible to employ an iterative process for the determination of both parameters. To attain this purpose, two methods were developed. The first one, named 'absolute method', used angular azimuthal positions of the peaks, related to the origin of the experimental diagram. The second method, named 'relative method', used azimuthal angular differences between two selected peaks. The values obtained for both parameters, in the two methods employed, were found by applying the angular azimuthal positions, for the first method, and the azimuthal angular differences, for the second method, upon appropriate theoretical indexing diagrams. An iterative process was applied in order to obtain the values of the parameters. In this process, the value obtained for one of the parameters was used in the determination of the other parameter. The process continues until both parameters converge. The iterative process was used in both methods. The relative method proved to be better than the absolute method. The best values of the parameters obtained by the relative method were: a 4.99638 ± 0.00057 angstrom and c = 5.46119 ± 0.00044 angstrom. (author)

Cryogenic laboratory (80 K - 4 K)

International Nuclear Information System (INIS)

Brad, Sebastian; Steflea, Dumitru

2002-01-01

condensing temperature (65 K). In the Joule-Thompson valve, the helium is expanded to 1.2 bar (corresponding to approx. 4.4 K). The resulting helium-liquid-mixture is transferred to the LHe container via a coaxial, vacuum-insulated transfer pipe. The He-cold-gas in the LHe container is transferred back to the low-pressure side of the heat exchanger E 205 to the cold-box via the transfer pipe. In the counter-flow to the cooling high-pressure flow the gas is now heated up to approx. 293 K in the heat exchangers. The gas leaving the cold-box at a pressure of approx. 1.07 bar is transferred to the suction side of the screw compressor together with the feed gas out of the helium reserve container via PC 111. To put into service the helium liquefier Type L5 tests were made to determine the performances and the cryogenic cycle efficiency: modified and complete components and spare parts, in order to adapted to our laboratory conditions; rebuild the liquid helium feeding system for the helium liquid tank and changed all the missed spare parts; redesigned the configuration for helium gas plant supplying system; vacuum test in order to determine that the leakage rates remain within tolerance levels; functioning tests for transfer line, oil-injected screw-compressor, helium recovery unit and electrical control unit. (authors)

Measurement of the effective $B_s^0 \\to K^+ K^-$ lifetime

CERN Document Server

Aaij, R; Adametz, A; Adeva, B; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves Jr, A A; Amato, S; Amhis, Y; Anderson, J; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Bachmann, S; Back, J J; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bates, A; Bauer, C; Bauer, Th; Bay, A; Beddow, J; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Benayoun, M; Bencivenni, G; Benson, S; Benton, J; Bernet, R; Bettler, M -O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blanks, C; Blouw, J; Blusk, S; Bobrov, A; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Büchler-Germann, A; Burducea, I; Bursche, A; Buytaert, J; Cadeddu, S; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carson, L; Carvalho Akiba, K; Casse, G; Cattaneo, M; Cauet, Ch; Charles, M; Charpentier, Ph; Chen, P; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Corti, G; Couturier, B; Cowan, G A; Craik, D; Currie, R; D'Ambrosio, C; David, P; David, P N Y; De Bonis, I; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Simone, P; Decamp, D; Deckenhoff, M; Degaudenzi, H; Del Buono, L; Deplano, C; Derkach, D; Deschamps, O; Dettori, F; Dickens, J; Dijkstra, H; Diniz Batista, P; Domingo Bonal, F; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisele, F; Eisenhardt, S; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Elsby, D; Esperante Pereira, D; Falabella, A; Färber, C; Fardell, G; Farinelli, C; Farry, S; Fave, V; Fernandez Albor, V; Ferro-Luzzi, M; Filippov, S; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Furcas, S; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garnier, J-C; Garofoli, J; Garra Tico, J; Garrido, L; Gascon, D; Gaspar, C; Gauld, R; Gauvin, N; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hampson, T; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Harrison, P F; Hartmann, T; He, J; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicks, E; Hoballah, M; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Huston, R S; Hutchcroft, D; Hynds, D; Iakovenko, V; Ilten, P; Imong, J; Jacobsson, R; Jaeger, A; Jahjah Hussein, M; Jans, E; Jansen, F; Jaton, P; Jean-Marie, B; Jing, F; John, M; Johnson, D; Jones, C R; Jost, B; Kaballo, M; Kandybei, S; Karacson, M; Karbach, T M; Keaveney, J; Kenyon, I R; Kerzel, U; Ketel, T; Keune, A; Khanji, B; Kim, Y M; Knecht, M; Kochebina, O; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kruzelecki, K; Kucharczyk, M; Kudryavtsev, V; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J -P; Lefèvre, R; Leflat, A; Lefrançois, J; Leroy, O; Lesiak, T; Li, L; Li, Y; Li Gioi, L; Lieng, M; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; von Loeben, J; Lopes, J H; Lopez Asamar, E; Lopez-March, N; Lu, H; Luisier, J; Mac Raighne, A; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Magnin, J; Malde, S; Mamunur, R M D; Manca, G; Mancinelli, G; Mangiafave, N; Marconi, U; Märki, R; Marks, J; Martellotti, G; Martens, A; Martin, L; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Massafferri, A; Mathe, Z; Matteuzzi, C; Matveev, M; Maurice, E; Maynard, B; Mazurov, A; McCarthy, J; McGregor, G; McNulty, R; Meissner, M; Merk, M; Merkel, J; Milanes, D A; Minard, M -N; Molina Rodriguez, J; Monteil, S; Moran, D; Morawski, P; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Muster, B; Mylroie-Smith, J; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Needham, M; Neufeld, N; Nguyen, A D; Nguyen-Mau, C; Nicol, M; Niess, V; Nikitin, N; Nikodem, T; Nomerotski, A; Novoselov, A; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Owen, P; Pal, B K; Palacios, J; Palano, A; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perego, D L; Perez Trigo, E; Pérez-Calero Yzquierdo, A; Perret, P; Perrin-Terrin, M; Pessina, G; Petrolini, A; Phan, A; Picatoste Olloqui, E; Pie Valls, B; Pietrzyk, B; Pilař, T; Pinci, D; Plackett, R; Playfer, S; Plo Casasus, M; Polci, F; Polok, G; Poluektov, A; Polycarpo, E; Popov, D; Popovici, B; Potterat, C; Powell, A; Prisciandaro, J; Pugatch, V; Puig Navarro, A; Qian, W; Rademacker, J H; Rakotomiaramanana, B; Rangel, M S; Raniuk, I; Raven, G; Redford, S; Reid, M M; dos Reis, A C; Ricciardi, S; Richards, A; Rinnert, K; Roa Romero, D A; Robbe, P; Rodrigues, E; Rodrigues, F; Rodriguez Perez, P; Rogers, G J; Roiser, S; Romanovsky, V; Rosello, M; Rouvinet, J; Ruf, T; Ruiz, H; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salzmann, C; Sanmartin Sedes, B; Sannino, M; Santacesaria, R; Santamarina Rios, C; Santinelli, R; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schaack, P; Schiller, M; Schindler, H; Schleich, S; Schlupp, M; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M -H; Schwemmer, R; Sciascia, B; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Sepp, I; Serra, N; Serrano, J; Seyfert, P; Shapkin, M; Shapoval, I; Shatalov, P; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Skwarnicki, T; Smith, N A; Smith, E; Smith, M; Sobczak, K; Soler, F J P; Solomin, A; Soomro, F; Souza, D; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stoica, S; Stone, S; Storaci, B; Straticiuc, M; Straumann, U; Subbiah, V K; Swientek, S; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Teklishyn, M; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Tolk, S; Topp-Joergensen, S; Torr, N; Tournefier, E; Tourneur, S; Tran, M T; Tsaregorodtsev, A; Tuning, N; Ubeda Garcia, M; Ukleja, A; Uwer, U; Vagnoni, V; Valenti, G; Vazquez Gomez, R; Vazquez Regueiro, P; Vecchi, S; Velthuis, J J; Veltri, M; Vesterinen, M; Viaud, B; Videau, I; Vieira, D; Vilasis-Cardona, X; Visniakov, J; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Vorobyev, V; Voß, C; Voss, H; Waldi, R; Wallace, R; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Webber, A D; Websdale, D; Whitehead, M; Wicht, J; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wishahi, J; Witek, M; Witzeling, W; Wotton, S A; Wright, S; Wu, S; Wyllie, K; Xie, Y; Xing, F; Xing, Z; Yang, Z; Young, R; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhong, L; Zvyagin, A

2012-01-01

A precise determination of the effective $B_s^0 \\rightarrow K^+ K^-$ lifetime can be used to constrain contributions from physics beyond the Standard Model in the $B_s^0$ meson system. Conventional approaches select $B$ meson decay products that are significantly displaced from the $B$ meson production vertex. As a consequence, $B$ mesons with low decay times are suppressed, introducing a bias to the decay time spectrum which must be corrected. This analysis uses a technique that explicitly avoids a lifetime bias by using a neural network based trigger and event selection. Using 1.0~fb$^{-1}$ of data recorded by the LHCb experiment, the effective $B_s^0 \\rightarrow K^+ K^-$ lifetime is measured as $1.455 \\pm 0.046 \\; \\mathrm{(stat.)} \\pm 0.006 \\; \\mathrm{(syst.)} \\, \\mathrm{ps}.$

An improved method for obtaining small pressed powder pellets for the analysis by XRF

International Nuclear Information System (INIS)

D'Angelo, J.; Marchevsky, E.; Strasser, E.; Perino, E.

2002-01-01

A rapid, very low cost of instrumentation and simple approach to specimen preparation for the analysis by X-ray fluorescence spectrometry is presented. This technique requires a few mg of powders samples, Which are compressed to produce pellets. This procedure is employed for determining major and trace elements in muscovites and K-feldspars. Factors affecting measured intensities, such as particle size and distribution, surface texture, pelletizing pressure, etc, are considered. A description of new sample preparation device, including technical characteristics, is also given. It is demonstrated that suitable specimen presentation to the X-ray beam is obtained by using our procedure. (author)

Measurement of $CP$ asymmetries and polarisation fractions in $B_s^0 \\rightarrow K^{*0}\\overline{K}{}^{*0}$ decays

CERN Document Server

Aaij, Roel; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassen, Rolf; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Bel, Lennaert; Belogurov, Sergey; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bertolin, Alessandro; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Bizzeti, Andrea; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Capriotti, Lorenzo; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carniti, Paolo; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casanova Mohr, Raimon; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cavallero, Giovanni; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pascal; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Dey, Biplab; Di Canto, Angelo; Di Ruscio, Francesco; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fol, Philip; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gascon, David; Gaspar, Clara; Gastaldi, Ugo; Gauld, Rhorry; Gavardi, Laura; Gazzoni, Giulio; Geraci, Angelo; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, Vladimir; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Humair, Thibaud; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jawahery, Abolhassan; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Karodia, Sarah; Kelsey, Matthew; Kenyon, Ian; Kenzie, Matthew; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Klimaszewski, Konrad; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lowdon, Peter; Lucchesi, Donatella; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Malinin, Alexander; Manca, Giulia; Mancinelli, Giampiero; Manning, Peter Michael; Mapelli, Alessandro; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Mauri, Andrea; Maurin, Brice; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Molina Rodriguez, Josue; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Katharina; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Nicol, Michelle; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Osorio Rodrigues, Bruno; Otalora Goicochea, Juan Martin; Otto, Adam; Owen, Patrick; Oyanguren, Maria Arantza; Pal, Bilas Kanti; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parkes, Christopher; Parkinson, Christopher John; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Pescatore, Luca; Petridis, Konstantin; Petrolini, Alessandro; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Quagliani, Renato; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruiz, Hugo; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skillicorn, Ian; Skwarnicki, Tomasz; Smith, Anthony; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Sterpka, Christopher Francis; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szumlak, Tomasz; T'Jampens, Stephane; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Todd, Jacob; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Trabelsi, Karim; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viana Barbosa, Joao Vitor; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Whitehead, Mark; Wiedner, Dirk; Wilkinson, Guy; Wilkinson, Michael; Williams, Matthew; Williams, Mike; Wilschut, Hans; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Wen Chao; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang

2015-01-01

An angular analysis of the decay $B_s^0 \\rightarrow K^{*0}\\overline{K}{}^{*0}$ is performed using $pp$ collisions corresponding to an integrated luminosity of $1.0$ ${fb}^{-1}$ collected by the LHCb experiment at a centre-of-mass energy $\\sqrt{s} = 7$ TeV. A combined angular and mass analysis separates six helicity amplitudes and allows the measurement of the longitudinal polarisation fraction $f_L = 0.201 \\pm 0.057 {(stat.)} \\pm 0.040{(syst.)}$ for the $B_s^0 \\rightarrow K^*(892)^0 \\overline{K}{}^*(892)^0$ decay. A large scalar contribution from the $K^{*}_{0}(1430)$ and $K^{*}_{0}(800)$ resonances is found, allowing the determination of additional $CP$ asymmetries. Triple product and direct $CP$ asymmetries are determined to be compatible with the Standard Model expectations. The branching fraction $\\mathcal{B}(B_s^0 \\rightarrow K^*(892)^0 \\overline{K}^*(892)^0)$ is measured to be $(10.8 \\pm 2.1 {(stat.)} \\pm 1.4 {(syst.)} \\pm 0.6 (f_d/f_s) ) \\times 10^{-6}$.

Ouabain affinity determining residues lie close to the Na/K pump ion pathway.

Science.gov (United States)

Artigas, Pablo; Gadsby, David C

2006-08-15

The Na/K pump establishes essential ion concentration gradients across animal cell membranes. Cardiotonic steroids, such as ouabain, are specific inhibitors of the Na/K pump. We exploited the marine toxin, palytoxin, to probe both the ion translocation pathway through the Na/K pump and the site of its interaction with ouabain. Palytoxin uncouples the pump's gates, which normally open strictly alternately, thus allowing both gates to sometimes be open, so transforming the pump into an ion channel. Palytoxin therefore permits electrophysiological analysis of even a single Na/K pump. We used outside-out patch recording of Xenopus alpha1beta3 Na/K pumps, which were made ouabain-resistant by point mutation, after expressing them in Xenopus oocytes. Endogenous, ouabain-sensitive, Xenopus alpha1beta3 Na/K pumps were silenced by continuous exposure to ouabain. We found that side-chain charge of two residues at either end of the alpha subunit's first extracellular loop, known to make a major contribution to ouabain affinity, strongly influenced conductance of single palytoxin-bound pump-channels by an electrostatic mechanism. The effects were mimicked by modification of cysteines introduced at those two positions with variously charged methanethiosulfonate reagents. The consequences of these modifications demonstrate that both residues lie in a wide vestibule near the mouth of the pump's ion pathway. Bound ouabain protects the site with the strongest influence on conductance from methanethiosulfonate modification, while leaving the site with the weaker influence unprotected. The results suggest a method for mapping the footprint of bound cardiotonic steroid on the extracellular surface of the Na/K pump.

Iron Quadrangle, Brazil. Elemental concentration determined by k0-instrumental neutron activation analysis. Part 1. Soil samples

International Nuclear Information System (INIS)

Menezes, M.A.B.C.; Palmieri, H.E.L.; Leonel, L.V.; Nalini, H.A.Jr.; Jacimovic, R.

2006-01-01

The Iron Quadrangle, Minas Gerais, Brazil, is rich in mineral occurrences and is considered one of the richest mineral-bearing regions in the world. Most investigations in this region have dealt with the determination of arsenic and mercury but so far few studies have been carried out aiming at determining other important elements. Having in mind the potential risk caused by mineral activities, this study was developed in order to assess the potential influence of the soil on foodstuffs. The soil samples were collected from three sites inside and outside the Iron Quadrangle. The samples were analyzed at the Laboratory for Neutron Activation Analysis, CDTN/CNEN by the k 0 -instrumental neutron activation analysis. This paper reports the elemental concentration determined in soil and emphasises the elements cited in the Brazilian environmental legislation for soil. This work also confirms the high elemental concentration of several minerals, however, it is difficult to distinguish the contamination from anthropogenic activities from the natural occurrence. (author)

HCO3(-)-coupled Na+ influx is a major determinant of Na+ turnover and Na+/K+ pump activity in rat hepatocytes

International Nuclear Information System (INIS)

Fitz, J.G.; Lidofsky, S.D.; Weisiger, R.A.; Xie, M.H.; Cochran, M.; Grotmol, T.; Scharschmidt, B.F.

1991-01-01

Recent studies in hepatocytes indicate that Na(+)-coupled HCO3- transport contributes importantly to regulation of intracellular pH and membrane HCO3- transport. However, the direction of net coupled Na+ and HCO3- movement and the effect of HCO3- on Na+ turnover and Na+/K+ pump activity are not known. In these studies, the effect of HCO3- on Na+ influx and turnover were measured in primary rat hepatocyte cultures with 22Na+, and [Na+]i was measured in single hepatocytes using the Na(+)-sensitive fluorochrome SBFI. Na+/K+ pump activity was measured in intact perfused rat liver and hepatocyte monolayers as Na(+)-dependent or ouabain-suppressible 86Rb uptake, and was measured in single hepatocytes as the effect of transient pump inhibition by removal of extracellular K+ on membrane potential difference (PD) and [Na+]i. In hepatocyte monolayers, HCO3- increased 22Na+ entry and turnover rates by 50-65%, without measurably altering 22Na+ pool size or cell volume, and HCO3- also increased Na+/K+ pump activity by 70%. In single cells, exposure to HCO3- produced an abrupt and sustained rise in [Na+]i from approximately 8 to 12 mM. Na+/K+ pump activity assessed in single cells by PD excursions during transient K+ removal increased congruent to 2.5-fold in the presence of HCO3-, and the rise in [Na+]i produced by inhibition of the Na+/K+ pump was similarly increased congruent to 2.5-fold in the presence of HCO3-. In intact perfused rat liver, HCO3- increased both Na+/K+ pump activity and O2 consumption. These findings indicate that, in hepatocytes, net coupled Na+ and HCO3- movement is inward and represents a major determinant of Na+ influx and Na+/K+ pump activity. About half of hepatic Na+/K+ pump activity appears dedicated to recycling Na+ entering in conjunction with HCO3- to maintain [Na+]i within the physiologic range

Experimental tests of CP, T and CPT symmetries using K0 and K-bar0

International Nuclear Information System (INIS)

Zavrtanik, D.; Angelopoulos, A.; Apostolakis, A.; Aslanides, E.; Bertin, V.; Ealet, A.; Fassnacht, P.; Henry-Couannier, F.; Le Gac, R.; Montanet, F.; Touchard, F.; Backenstoss, G.; Leimgruber, F.; Pavlopoulos, P.; Polivka, G.; Rickenbach, R.; Schietinger, T.; Tauscher, L.; Vlachos, S.; Bargassa, P.

1998-01-01

The CPLEAR experiment at CERN measured the CP and CPT violation parameters and determined in a direct way the T violation. The results allow the determination of the CPT violation parameters in the neutral kaon mixing with a precision better than a few 10 -4 . The mass equality between K 0 and K-tilde 0 is tested down to the level of 10 -19 GeV. In addition, physics on a scale close to the Planck mass is probed for the first time

Cross Sections for the Reactions e+e to K+ K- pi+pi-, K+ K- pi0pi0, and K+ K- K+ K- Measured Using Initial-State Radiation

Energy Technology Data Exchange (ETDEWEB)

Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; /INFN, Trieste /Trieste U.; Milanes, D.A.; /INFN, Trieste /Trieste U.; Palano, A.; /INFN, Trieste /Trieste U.; Pappagallo, M.; /INFN, Trieste /Trieste U. /INFN, Bari /Bari U. /Bari U. /INFN, Bari; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /LBL, Berkeley /UC, Berkeley; Koch, H.; Schroeder, T.; /Ruhr U., Bochum; Asgeirsson, D.J.; /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Trieste /INFN, Trieste /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /INFN, Ferrara /Ferrara U. /Frascati /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /INFN, Trieste /Trieste U. /INFN, Trieste /INFN, Genoa /Genoa U. /Indian Inst. Tech., Guwahati /Harvard U. /Harvey Mudd Coll. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U., Comp. Sci. Dept. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /INFN, Trieste /INFN, Trieste /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Perugia /Perugia U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /INFN, Pisa /Princeton U. /INFN, Trieste /INFN, Trieste /INFN, Trieste /Trieste U. /INFN, Trieste /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /INFN, Trieste /INFN, Trieste /INFN, Rome /Rome U. /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

2011-08-19

We study the processes e{sup +}e{sup -} {yields} K{sup +}K{sup -}{pi}{sup +}{pi}-{gamma}, K{sup +}K{sup -}{pi}{sup 0}{pi}{sup 0}{gamma}, and K{sup +}K{sup -}K{sup +}K{sup -}{gamma}, where the photon is radiated from the initial state. About 84000, 8000, and 4200 fully reconstructed events, respectively, are selected from 454 fb{sup -1} of BABAR data. The invariant mass of the hadronic final state defines the e{sup +}e{sup -} center-of-mass energy, so that the K{sup +}K{sup -}{pi}{sup +}{pi}{sup -}{gamma} data can be compared with direct measurements of the e{sup +}e{sup -} {yields} K{sup +}K{sup -}{pi}{sup +}{pi}{sup -} reaction. No direct measurements exist for the e{sup +}e{sup -} {yields} K{sup +}K{sup -}{pi}{sup 0}{pi}{sup 0} or e{sup +}e{sup -} {yields} K{sup +}K{sup -}K{sup +}K{sup -} reactions, and we present an update of our previous result with doubled statistics. Studying the structure of these events, we find contributions from a number of intermediate states, and extract their cross sections. In particular, we perform a more detailed study of the e{sup +}e{sup -} {yields} {phi}(1020){pi}{pi}{gamma} reaction, and confirm the presence of the Y (2175) resonance in the {phi}(1020)f{sub 0}(980) and K{sup +}K{sup -} f{sub 0}(980) modes. In the charmonium region, we observe the J/{psi} in all three final states and in several intermediate states, as well as the {phi}(2S) in some modes, and measure the corresponding branching fractions.

Increasing potassium (K release from K-containing minerals in the presence of insoluble phosphate by bacteria

Directory of Open Access Journals (Sweden)

Mohammad Reza Sarikhani

2016-03-01

Full Text Available Introduction: Phosphorus and potassium are major essential macronutrients for biological growth and development. Application of soil microorganisms is one approach to enhance crop growth. Some bacteria are efficient in releasing K and solubilizing P from mineral sources but their behavior was not studied more in presence together. Materials and methods: In this study the ability of seven bacterial strains, including Pseudomonas putida P13, P. putida Tabriz, P. fluorescens Tabriz, P. fluorescens Chao, Pantoea agglomerans P5, Azotobacter sp. and Bacillus megaterium JK3 to release mineral K from muscovite and biotite with application of insoluble (Ca3(PO42 or soluble (Na2HPO4 P-sources was investigated. Nutrient Broth was used to prepare an overnight culture of bacteria to inoculate in Aleksandrov medium, which was used to study the dissolution of silicate minerals. It should be mentioned that Aleksandrov medium was used to determine the amount of released P from tricalcium phosphate (TCP while muscovite was added to the medium as a sole source of potassium. Concentration of P was determined spectrophotometrically by ammonium-vanadate-molybdate method and K was determined by flame photometry. Results: The insoluble P-source led to a significantly increased released K into assay medium (66%, and the net release of K from the biotite was significantly enhanced. Among bacterial strains, the highest mean of released K was observed with P. putida P13 which released more K (27% than the control. The amounts of released K from micas in the presence of insoluble and soluble phosphate by P. putida P13 were 8.25 and 4.87 mg/g, respectively. Discussion and conclusion: Application of insoluble phosphate could increase K release from mica minerals. The enhanced releasing of mineral K might be attributed to the release of organic acids from the bacteria, a mechanism which plays a pivotal role in solubilizing phosphate from inorganic source of phosphate.

Measurement of plasma vitamin K1 (phylloquinone) and K2 (menaquinones-4 and -7) using HPLC-tandem mass spectrometry

NARCIS (Netherlands)

Riphagen, Ineke J; van der Molen, Jan C; van Faassen, Martijn; Navis, Gerjan; de Borst, Martin H; Muskiet, Frits A J; de Jong, Wilhelmina H A; Bakker, Stephan J L; Kema, Ido P

BACKGROUND: Given the growing interest in the health benefits of vitamin K, there is great need for development of new high-throughput methods for quantitative determination of vitamin K in plasma. We describe a simple and rapid method for measurement of plasma vitamin K1 (phylloquinone [PK]) and K2

K-West and K-East basin thermal analyses for dry conditions

International Nuclear Information System (INIS)

Beaver, T.R.; Cramer, E.R.; Hinman, C.A.

1994-01-01

Detailed 3 dimensional thermal analyses of the 100K East and 100 K West basins were conducted to determine the peak fuel temperature for intact fuel in the event of a complete loss of water from the basins. Thermal models for the building, an array of fuel encapsulation canisters on the basin floor, and the fuel within a single canister are described along with conservative predictions for the maximum expected temperatures for the loss of water event

Diagenesis of sedimentary phosphorite deposits in Djebel Onk basin, Algeria

DEFF Research Database (Denmark)

Redjehimi, Hacène; Friis, Henrik; Boutaleb, Abdelhak

affecting the Upper Paleocene phosphorites of the Djebel Onk include: (1) accumulation of phosphate grains, (2) compaction, (3) dolomite cementation, (3) minor amount of other diagenetic mineral cements: opal-CT, K-feldspar overgrowth, clinoptinolite and pyrite, (4) dissolution of dolomite crystals...

Determining metal ion distributions using resonant scattering at very high-energy K-edges: Bi/Pb in Pb5Bi6Se14

International Nuclear Information System (INIS)

Zhang Yuegang; Lee, P.L.; Shastri, S.D.; Shu Deming; Wilkinson, A.P.; Chung Duck-Young; Kanatzidis, M.G.

2005-01-01

Powder diffraction data collected at ∝ 86 keV, and just below both the Pb and the Bi K-edges, on an imaging plate detector using synchrotron radiation from the Advanced Photon Source have been used to examine the Pb/Bi distribution over the 11 crystallographically distinct sites in Pb 5 Bi 6 Se 14 [space group P2 1 /m, a=16.0096(2) Aa, b=4.20148(4) Aa, c=21.5689(3) Aa and β=97.537(1) 0 ]. The scattering factors needed for the analyses were determined both by Kramers- Kronig transformation of absorption spectra and by analyses of diffraction patterns from reference compounds. Even with the relatively low scattering contrast that is available at the K-edges, it was possible to determine the Pb/Bi distribution and probe the presence of cation site vacancies in the material. The current results indicate that resonant scattering measurements at high-energy K-edges are a viable, and perhaps preferable, route to site occupancies when absorption from the sample or sample environment/container is a major barrier to the acquisition of high-quality resonant scattering data at lower-energy edges

DETERMINATION OF LIMIT DETECTION OF THE ELEMENTS N, P, K, Si, Al, Fe, Cu, Cd, WITH FAST NEUTRON ACTIVATION USING NEUTRON GENERATOR

OpenAIRE

Sunardi, Sunardi; Muryono, Muryono

2010-01-01

Determination of limit detection of the elements N, P, K, Si, Al, Fe, Cu, Cd, with fast neutron activation using neutron generator has been done.  Samples prepared from SRM 2704, N, P, K elements from MERCK, Cu, Cd, Al from activation foil made in San Carlos, weighted and packed for certain weight then iradiated during 30 minutes with 14 MeV fast neutron using the neutron generator and then counted with gamma spectrometry (accuspec).  At this research condition of neutron generator was set at...

A simple and sensitive method for determination of vitamins D3 and K1 in rat plasma: application for an in vivo pharmacokinetic study.

Science.gov (United States)

Gershkovich, Pavel; Ibrahim, Fady; Sivak, Olena; Darlington, Jerald W; Wasan, Kishor M

2014-03-01

To develop and to validate a simple but sensitive method for determination of vitamins D3 and K1 in rat plasma. The sample treatment included protein precipitation by cold acetonitrile, evaporation, reconstitution with methanol and filtration. The chromatography conditions included Xterra RP18 3.5 µm 4.6 × 100 mm column at ambient temperature and mobile phase consisting of methanol/water (93/7, v/v) at 0.5 mL/min flow rate. Vitamin D3 and probucol were detected at 265 nm and vitamin K1 at 239 nm. Rats were administered intravenously by 0.1 mg/kg of vitamin D3 or K1 and the blood samples were withdrawn pre-administration and at pre-determined time points post-administration. The pharmacokinetic analysis was performed using a non-compartmental approach. The calibration curves in rat plasma were linear up to 5000 ng/mL for both vitamins. The limit of quantification (LOQ) was 20 ng/mL for vitamin D3 and 40 ng/mL for K1. Inter- and intra-day precision and accuracy were below 15%. The pharmacokinetic parameters of vitamin D3 following intravenous administration were: AUC0-∞ = 11323 ± 1081 h × ng/mL, Vd = 218 ± 80 mL/kg, CL = 8.9 ± 0.8 mL/h/kg, t1/2 = 16.8 ± 5 h; and of vitamin K1: AUC0-∞ = 2495 ± 297 h × ng/mL, Vd = 60 ±24 mL/kg, CL = 40.5 ± 5.1 mL/h/kg, t1/2 = 1.1 ±0.5 h. The developed HPLC-UV assay is a simple and sensitive method for the determination of vitamins D3 and K1 in rat plasma. A higher dose of vitamin K1 should be used in future studies for accurate estimation of pharmacokinetic parameters. The data show the suitability of the assay for pharmacokinetic studies in rats.

Determination of the Earth's pole tide Love number k2 from observations of polar motion using an adaptive Kalman filter approach

Science.gov (United States)

Seitz, F.; Kirschner, S.; Neubersch, D.

2012-09-01

The geophysical interpretation of observed time series of Earth rotation parameters (ERP) is commonly based on numerical models that describe and balance variations of angular momentum in various subsystems of the Earth. Naturally, models are dependent on geometrical, rheological and physical parameters. Many of these are weakly determined from other models or observations. In our study we present an adaptive Kalman filter approach for the improvement of parameters of the dynamic Earth system model DyMEG which acts as a simulator of ERP. In particular we focus on the improvement of the pole tide Love number k2. In the frame of a sensitivity analysis k2 has been identified as one of the most crucial parameters of DyMEG since it directly influences the modeled Chandler oscillation. At the same time k2 is one of the most uncertain parameters in the model. Our simulations with DyMEG cover a period of 60 years after which a steady state of k2 is reached. The estimate for k2, accounting for the anelastic response of the Earth's mantle and the ocean, is 0.3531 + 0.0030i. We demonstrate that the application of the improved parameter k2 in DyMEG leads to significantly better results for polar motion than the original value taken from the Conventions of the International Earth Rotation and Reference Systems Service (IERS).

Determination of infinite dilution activity coefficients using HS-SPME/GC/FID for hydrocarbons in furfural at temperatures of (298.15, 308.15, and 318.15) K

International Nuclear Information System (INIS)

Arantes Furtado, Filipe; Vieira Coelho, Gerson Luiz

2012-01-01

Highlights: ► Two approaches were proposed using SPME on determination of infinite dilution activity coefficients. ► Infinite dilution activity coefficients of nine solutes in solvent furfural at T = (298.15, 308.15, and 318.15) K. ► Fiber–gas partition coefficients of nine solutes on PDMS at T = (298.15, 308.15, and 318.15) K. ► Optical microscopy analysis and statistical tests to measure possible damages on fiber coating. ► Advantages and limitations of methodology proposed were discussed. - Abstract: A new methodology using the headspace solid phase microextraction (HS-SPME) technique has been used to evaluate the infinite dilution activity coefficient (γ 12 ∞ ) of nine hydrocarbons (alkanes, cycloalkanes, and aromatics) in furfural solvent. The main objective of this study was to validate a faster and lower cost methodology expanding the use of HS-SPME to determine infinite dilution activity of solutes in organic solvents. Two approaches were proposed for the determination of γ 12 ∞ in order to use this technique (HS-SPME). In addition, the fiber–gas partition coefficients (K fg ) for each analyte at each of the studied temperatures were determined. The activity and partition coefficients have been reported at temperatures of (298.15, 308.15, and 318.15) K. The data were compared with the literature infinite dilution data determined by other methods such as liquid–gas chromatography (GLC) and gas stripping. Partial molar excess enthalpies of mixing at infinite dilution for each solute have been determined. The fibers were tested before and after each experiment, using statistical methods to ensure that their properties do not change during the experiments. The fibers were also analyzed by optical microscopy to evaluate possible surface damage by comparing them with new fibers. The activity coefficient values correlated well with the data in the literature and showed average deviations less than 10%.

Constraints on the Parental Melts of Enriched Shergottites from Image Analysis and High Pressure Experiments

Science.gov (United States)

Collinet, M.; Medard, E.; Devouard, B.; Peslier, A.

2012-01-01

Martian basalts can be classified in at least two geochemically different families: enriched and depleted shergottites. Enriched shergottites are characterized by higher incompatible element concentrations and initial Sr-87/Sr-86 and lower initial Nd-143/Nd-144 and Hf-176/Hf-177 than depleted shergottites [e.g. 1, 2]. It is now generally admitted that shergottites result from the melting of at least two distinct mantle reservoirs [e.g. 2, 3]. Some of the olivine-phyric shergottites (either depleted or enriched), the most magnesian Martian basalts, could represent primitive melts, which are of considerable interest to constrain mantle sources. Two depleted olivine-phyric shergottites, Yamato (Y) 980459 and Northwest Africa (NWA) 5789, are in equilibrium with their most magnesian olivine (Fig. 1) and their bulk rock compositions are inferred to represent primitive melts [4, 5]. Larkman Nunatak (LAR) 06319 [3, 6, 7] and NWA 1068 [8], the most magnesian enriched basalts, have bulk Mg# that are too high to be in equilibrium with their olivine megacryst cores. Parental melt compositions have been estimated by subtracting the most magnesian olivine from the bulk rock composition, assuming that olivine megacrysts have partially accumulated [3, 9]. However, because this technique does not account for the actual petrography of these meteorites, we used image analysis to study these rocks history, reconstruct their parent magma and understand the nature of olivine megacrysts.

Determination of Cl, K, and Na in the blood serum of healthy elderly in the city of Sao Paulo, SP

International Nuclear Information System (INIS)

Araujo, Nathalia Souza de; Saiki, Mitiko

2009-01-01

This work determined the blood serum concentration of Cl, K, and Na from a healthy elderly population of the city of Sao Paulo, Sao Paulo, Brazil viewing the comparison with reference values used in clinical laboratories. For collecting these samples the present work were approved by the Ethic Committee of the FMUSP and IPEN-CNEN/SP. The quality of the analytical results were evaluated by the analysis of the reference material certification NIST 1577b Bovine Liver. The results presented good accuracy and precision due to the fact that they presented relative errors less than 5.2 % and standard deviation less than 8.6 %. The average concentrations (mmol L -1 ) of Cl in the analysed serum were 99.1; the K were 3.9 and the Na were 136.9. The obtained data allows the to conclude that the mostly of the elderly presented Cl, K and Na concentrations in the range of reference values used in the clinical laboratories

Direct determination of k Q factors for cylindrical and plane-parallel ionization chambers in high-energy electron beams from 6 MeV to 20 MeV

Science.gov (United States)

Krauss, A.; Kapsch, R.-P.

2018-02-01

For the ionometric determination of the absorbed dose to water, D w, in high-energy electron beams from a clinical accelerator, beam quality dependent correction factors, k Q, are required. By using a water calorimeter, these factors can be determined experimentally and potentially with lower standard uncertainties than those of the calculated k Q factors, which are tabulated in various dosimetry protocols. However, one of the challenges of water calorimetry in electron beams is the small measurement depths in water, together with the steep dose gradients present especially at lower energies. In this investigation, water calorimetry was implemented in electron beams to determine k Q factors for different types of cylindrical and plane-parallel ionization chambers (NE2561, NE2571, FC65-G, TM34001) in 10 cm  ×  10 cm electron beams from 6 MeV to 20 MeV (corresponding beam quality index R 50 ranging from 1.9 cm to 7.5 cm). The measurements were carried out using the linear accelerator facility of the Physikalisch-Technische Bundesanstalt. Relative standard uncertainties for the k Q factors between 0.50% for the 20 MeV beam and 0.75% for the 6 MeV beam were achieved. For electron energies above 8 MeV, general agreement was found between the relative electron energy dependencies of the k Q factors measured and those derived from the AAPM TG-51 protocol and recent Monte Carlo-based studies, as well as those from other experimental investigations. However, towards lower energies, discrepancies of up to 2.0% occurred for the k Q factors of the TM34001 and the NE2571 chamber.

Direct determination of k Q factors for cylindrical and plane-parallel ionization chambers in high-energy electron beams from 6 MeV to 20 MeV.

Science.gov (United States)

Krauss, A; Kapsch, R-P

2018-02-06

For the ionometric determination of the absorbed dose to water, D w , in high-energy electron beams from a clinical accelerator, beam quality dependent correction factors, k Q , are required. By using a water calorimeter, these factors can be determined experimentally and potentially with lower standard uncertainties than those of the calculated k Q factors, which are tabulated in various dosimetry protocols. However, one of the challenges of water calorimetry in electron beams is the small measurement depths in water, together with the steep dose gradients present especially at lower energies. In this investigation, water calorimetry was implemented in electron beams to determine k Q factors for different types of cylindrical and plane-parallel ionization chambers (NE2561, NE2571, FC65-G, TM34001) in 10 cm  ×  10 cm electron beams from 6 MeV to 20 MeV (corresponding beam quality index R 50 ranging from 1.9 cm to 7.5 cm). The measurements were carried out using the linear accelerator facility of the Physikalisch-Technische Bundesanstalt. Relative standard uncertainties for the k Q factors between 0.50% for the 20 MeV beam and 0.75% for the 6 MeV beam were achieved. For electron energies above 8 MeV, general agreement was found between the relative electron energy dependencies of the k Q factors measured and those derived from the AAPM TG-51 protocol and recent Monte Carlo-based studies, as well as those from other experimental investigations. However, towards lower energies, discrepancies of up to 2.0% occurred for the k Q factors of the TM34001 and the NE2571 chamber.

Mineralogy of dust deposited during the Harmattan season in Ghana

DEFF Research Database (Denmark)

He, Changling; Breuning-Madsen, Henrik; Awadzi, Theodore W.

2007-01-01

Ocean. In this project, we studied samples of dust and topsoils in various agroecological zones, from the north to the south of Ghana, focussing mainly on the mineralogy of these materials. Some data about grain sizes and morphology of the samples are also presented. Feldspars, together with quartz......In Ghana, a dust-laden Harmattan wind blows from the Sahara in the period November to March. Some of the dust is trapped in the vegetation, in lakes and other inland waters, and a little on the bare land, whereas the rest of the dust is blown further away to the Ivory Coast or out into the Atlantic......, are the common minerals found in Harmattan dust, but the relative contents of K-feldspars and plagioclase vary markedly in the different zones. This variation is consistent with changes in the relative content of the feldspars in the topsoil, indicating a substantial local contribution to the Harmattan dust...

Determination of the photoeffect cross section and the K- absorption edge energy of Dy, Ta, Pt and Au atoms using Bremsstrahlung

International Nuclear Information System (INIS)

Garcia-Alvarez, J. A.; Lopez-Pino, N.; Diaz Rizo, O.; Corrales, Y.; Padilla-Cabal, F.; Perez-Liva, M.; D' Alessandro, K.; Maidana, N. L.

2011-01-01

An experiment to determine the K-shell photoelectric cross-section (CS) of Dy, Ta, Pt and Au atoms was implemented at the Nuclear Analytical Laboratory (LAN) of the InSTEC. Bremsstrahlung photons, produced by 90 Sr- 90 Y beta particles hitting a thin Ni converter, were used to irradiate the foils target of the elements under study. A HPGe detector, coupled to standard nuclear instrumentation, collected the incident and transmitted spectra. A sharp decrease in intensity at the K-shell binding energy was observed in the transmitted spectra. The photon beam divergence effects were corrected with a calibration curve calculated by means of Monte Carlo simulations (MCNPX 2.6). In order to establish accurately the CS at the K-edge energy, the obtained data was processed by two methods: fitting the total CS to a sigmoidal function, as well as the CS branches around the K edge to the empirical law σ=(A/E) n . The results were compared with experimental and theoretical values showing the best agreement when the thinner foils were used. (Author)

Determination of $f_s/f_d$ for 7 TeV $pp$ collisions and a measurement of the branching fraction of the decay $B^0 \\to D^{-}K^{+}$

CERN Document Server

Aaij, R; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Alkhazov, G; Alvarez Cartelle, P; Alves Jr, A A; Amato, S; Amhis, Y; Amoraal, J; Anderson, J; Appleby, R B; Aquines Gutierrez, O; Arrabito, L; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Bachmann, S; Back, J J; Bailey, D S; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bates, A; Bauer, C; Bauer, Th; Bay, A; Bediaga, I; Belous, K; Belyaev, I; Ben-Haim, E; Benayoun, M; Bencivenni, G; Benson, S; Benton, J; Bernet, R; Bettler, M O; van Beuzekom, M; Bien, A; Bifani, S; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blanks, C; Blouw, J; Blusk, S; Bobrov, A; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brisbane, S; Britsch, M; Britton, T; Brook, N H; Büchler-Germann, A; Bursche, A; Buytaert, J; Cadeddu, S; Carvajal, J.M.Caicedo; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carson, L; Carvalho Akiba, K; Casse, G; Cattaneo, M; Charles, M; Charpentier, Ph; Chiapolini, N; Cid Vidal, X; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Collins, P; Constantin, F; Conti, G; Contu, A; Cook, A; Coombes, M; Corti, G; Cowan, G A; Currie, R; D'Almagne, B; D'Ambrosio, C; David, P; David, P N Y; De Bonis, I; De Capua, S; De Cian, M; De Lorenzi, F; De Miranda, J M; De Paula, L; De Simone, P; Decamp, D; Deckenhoff, M; Degaudenzi, H; Deissenroth, M; Del Buono, L; Deplano, C; Deschamps, O; Dettori, F; Dickens, J; Dijkstra, H; Diniz Batista, P; Dossett, D; Dovbnya, A; Dupertuis, F; Dzhelyadin, R; Eames, C; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisele, F; Eisenhardt, S; Ekelhof, R; Eklund, L; Elsasser, Ch; d'Enterria, D G; Esperante Pereira, D; Esteve, L; Falabella, A; Fanchini, E; Farber, C; Fardell, G; Farinelli, C; Farry, S; Fave, V; Fernandez Albor, V; Ferro-Luzzi, M; Filippov, S; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Frank, M; Frei, C; Frosini, M; Furcas, S; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garnier, J-C; Garofoli, J; Garrido, L; Gaspar, C; Gauvin, N; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Gregson, S; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Haefeli, G; Haines, S C; Hampson, T; Hansmann-Menzemer, S; Harji, R; Harnew, N; Harrison, J; Harrison, P F; He, J; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hofmann, W; Holubyev, K; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Huston, R S; Hutchcroft, D; Hynds, D; Iakovenko, V; Ilten, P; Imong, J; Jacobsson, R; Jahjah Hussein, M; Jans, E; Jansen, F; Jaton, P; Jean-Marie, B; Jing, F; John, M; Johnson, D; Jones, C R; Jost, B; Kandybei, S; Karbach, T M; Keaveney, J; Kerzel, U; Ketel, T; Keune, A; Khanji, B; Kim, Y M; Knecht, M; Koblitz, S; Koppenburg, P; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Krocker, G; Krokovny, P; Kruse, F; Kruzelecki, K; Kucharczyk, M; Kukulak, S; Kumar, R; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Le Gac, R; van Leerdam, J; Lees, J P; Lefèvre, R; Leflat, A; Lefrancois, J; Leroy, O; Lesiak, T; Li, L; Li, Y Y; Li Gioi, L; Lieng, M; Lindner, R; Linn, C; Liu, B; Liu, G; Lopes, J H; Lopez Asamar, E; Lopez-March, N; Luisier, J; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Magnin, J; Maier, A; Malde, S; Mamunur, R M D; Manca, G; Mancinelli, G; Mangiafave, N; Marconi, U; Märki, R; Marks, J; Martellotti, G; Martens, A; Martin, L; Martín Sánchez, A; Martinez Santos, D; Massafferri, A; Mathe, Z; Matteuzzi, C; Matveev, M; Maurice, E; Maynard, B; Mazurov, A; McGregor, G; McNulty, R; Mclean, C; Meissner, M; Merk, M; Merkel, J; Messi, R; Miglioranzi, S; Milanes, D A; Minard, M N; Monteil, S; Moran, D; Morawski, P; Morris, J V; Mountain, R; Mous, I; Muheim, F; Muller, K; Muresan, R; Muryn, B; Musy, M; Naik, P; Nakada, T; Nandakumar, R; Nardulli, J; Nedos, M; Needham, M; Neufeld, N; Nguyen-Mau, C; Nicol, M; Nies, S; Niess, V; Nikitin, N; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Pal, B; Palacios, J; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Paterson, S K; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perego, D L; Perez Trigo, E; Pérez-Calero Yzquierdo, A; Perret, P; Perrin-Terrin, M; Pessina, G; Petrella, A; Petrolini, A; Pie Valls, B; Pietrzyk, B; Pilar, T; Pinci, D; Plackett, R; Playfer, S; Plo Casasus, M; Polok, G; Poluektov, A; Polycarpo, E; Popov, D; Popovici, B; Potterat, C; Powell, A; du Pree, T; Pugatch, V; Puig Navarro, A; Qian, W; Rademacker, J H; Rakotomiaramanana, B; Raniuk, I; Raven, G; Redford, S; Reid, M M; dos Reis, A C; Ricciardi, S; Rinnert, K; Romero, D.A.Roa; Robbe, P; Rodrigues, E; Rodrigues, F; Rodriguez Cobo, C; Rodriguez Perez, P; Rogers, G J; Romanovsky, V; Rouvinet, J; Ruf, T; Ruiz, H; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salzmann, C; Sannino, M; Santacesaria, R; Santinelli, R; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schaack, P; Schiller, M; Schleich, S; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M H; Schwemmer, R; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Serra, N; Serrano, J; Seyfert, P; Shao, B; Shapkin, M; Shapoval, I; Shatalov, P; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Skottowe, H P; Skwarnicki, T; Smith, A C; Smith, N A; Sobczak, K; Soler, F J P; Solomin, A; Soomro, F; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stoica, S; Stone, S; Storaci, B; Straumann, U; Styles, N; Swientek, S; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Topp-Joergensen, S; Tran, M T; Tsaregorodtsev, A; Tuning, N; Ukleja, A; Urquijo, P; Uwer, U; Vagnoni, V; Valenti, G; Vazquez Gomez, R; Vazquez Regueiro, P; Vecchi, S; Velthuis, J J; Veltri, M; Vervink, K; Viaud, B; Videau, I; Vilasis-Cardona, X; Visniakov, J; Vollhardt, A; Voong, D; Vorobyev, A; Voss, H; Wacker, K; Wandernoth, S; Wang, J; Ward, D R; Webber, A D; Websdale, D; Whitehead, M; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wishahi, J; Witek, M; Witzeling, W; Wotton, S A; Wyllie, K; Xie, Y; Xing, F; Yang, Z; Young, R; Yushchenko, O; Zavertyaev, M; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhong, L; Zverev, E; Zvyagin, A

2011-01-01

The relative abundance of the three decay modes $B^0 \\to D^- K^+$, $B^0 \\to D^- \\pi^+$ and $B^0_s \\to D_s^- \\pi^+$ produced in 7 TeV $pp$ collisions at the LHC is determined from data corresponding to an integrated luminosity of 35 pb$^{-1}$. The branching fraction of $B^0 \\to D^- K^+$ is found to be $\\cal B (B^0 \\to D^- K^+) = (2.01 \\pm 0.18^{\\textrm{stat}} \\pm 0.14^{\\textrm{syst}})\\times 10^{-4}$. The ratio of fragmentation fractions $f_s/f_d$ is determined through the relative abundance of $B^0_s \\to D_s^- \\pi^+$ to $B^0 \\to D^- K^+$ and $B^0 \\to D^-\\pi^+$, leading to $f_s/f_d = 0.253 \\pm 0.017 \\pm 0.017 \\pm 0.020$, where the uncertainties are statistical, systematic, and theoretical respectively.

Experimental Determination of pK[subscript a] Values and Metal Binding for Biomolecular Compounds Using [superscript 31]P NMR Spectroscopy

Science.gov (United States)

Swartz, Mason A.; Tubergen, Philip J.; Tatko, Chad D.; Baker, Rachael A.

2018-01-01

This lab experiment uses [superscript 31]P NMR spectroscopy of biomolecules to determine pK[subscript a] values and the binding energies of metal/biomolecule complexes. Solutions of adenosine nucleotides are prepared, and a series of [superscript 31]P NMR spectra are collected as a function of pH and in the absence and presence of magnesium or…

Detection of food irradiation with luminescence methods

International Nuclear Information System (INIS)

Anderle, H.

1997-06-01

Food irradiation is applied as method for the preservation of foods, the prevention of food spoilage and the inhibition of food-borne pathogens. Doses exceeding 10 kGy (10 kJ/kg) are not recommended by the WHO. The different legislation requires methods for the detection and the closimetry of irradiated foods. Among the physical methods based on the radiation-induced changes in inorganic, nonhygroscopic crystalline solids are thermoluminescence (TL), photostimulated luminescence (PSL) and lyoluminescence (LL) measurement. The luminescence methods were tested on natural minerals. Pure quartz, feldspars, calcite, aragonite and dolomite of known origin were irradiated, read out and analyzed to determine the influence of luminescence-activators and deactivators. Carbonate minerals show an orange-red TL easily detectable by blue-sensitive photomultiplier tubes. TIL-inactive carbonate samples may be identified by a lyoluminescence method using the reaction of trapped irradiation-generated charge carriers with the solvent during crystal-lattice breakup. The fine-ground mineral is dissolved in an alkaline complexing agent/chemiluminescence sensitizer/chemiluminescence catalyst (EDTA/luminol/hemin) reagent mixture. The TL and PSL of quartz is too weak to contribute a significant part for the corresponding signals in polymineral dust. Alkali and soda feldspar show intense TL and PSL. The temperature maxima in the TL glow curves allow a clear distinction. PSL does not give this additional information, it suffers from bleaching by ambient light and requires light-protection. Grain disinfestated with low irradiation doses (500 Gy) may not identified by both TL and PSL measurement. The natural TL of feldspar particles may be overlap with the irradiation-induced TL of other minerals. As a routine method, irradiated spices are identified with TL measurement. The dust particles have to be enriched by heavy-liquid flotation and centrifugation. The PSL method allows a clear

Loss of mitogen-activated protein kinase kinase kinase 4 (MAP3K4 reveals a requirement for MAPK signalling in mouse sex determination.

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Debora Bogani

2009-09-01

Full Text Available Sex determination in mammals is controlled by the presence or absence of the Y-linked gene SRY. In the developing male (XY gonad, sex-determining region of the Y (SRY protein acts to up-regulate expression of the related gene, SOX9, a transcriptional regulator that in turn initiates a downstream pathway of testis development, whilst also suppressing ovary development. Despite the requirement for a number of transcription factors and secreted signalling molecules in sex determination, intracellular signalling components functioning in this process have not been defined. Here we report a role for the phylogenetically ancient mitogen-activated protein kinase (MAPK signalling pathway in mouse sex determination. Using a forward genetic screen, we identified the recessive boygirl (byg mutation. On the C57BL/6J background, embryos homozygous for byg exhibit consistent XY gonadal sex reversal. The byg mutation is an A to T transversion causing a premature stop codon in the gene encoding MAP3K4 (also known as MEKK4, a mitogen-activated protein kinase kinase kinase. Analysis of XY byg/byg gonads at 11.5 d post coitum reveals a growth deficit and a failure to support mesonephric cell migration, both early cellular processes normally associated with testis development. Expression analysis of mutant XY gonads at the same stage also reveals a dramatic reduction in Sox9 and, crucially, Sry at the transcript and protein levels. Moreover, we describe experiments showing the presence of activated MKK4, a direct target of MAP3K4, and activated p38 in the coelomic region of the XY gonad at 11.5 d post coitum, establishing a link between MAPK signalling in proliferating gonadal somatic cells and regulation of Sry expression. Finally, we provide evidence that haploinsufficiency for Map3k4 accounts for T-associated sex reversal (Tas. These data demonstrate that MAP3K4-dependent signalling events are required for normal expression of Sry during testis development, and

Loss of Mitogen-Activated Protein Kinase Kinase Kinase 4 (MAP3K4) Reveals a Requirement for MAPK Signalling in Mouse Sex Determination

Science.gov (United States)

Bogani, Debora; Siggers, Pam; Brixey, Rachel; Warr, Nick; Beddow, Sarah; Edwards, Jessica; Williams, Debbie; Wilhelm, Dagmar; Koopman, Peter; Flavell, Richard A.; Chi, Hongbo; Ostrer, Harry; Wells, Sara; Cheeseman, Michael; Greenfield, Andy

2009-01-01

Sex determination in mammals is controlled by the presence or absence of the Y-linked gene SRY. In the developing male (XY) gonad, sex-determining region of the Y (SRY) protein acts to up-regulate expression of the related gene, SOX9, a transcriptional regulator that in turn initiates a downstream pathway of testis development, whilst also suppressing ovary development. Despite the requirement for a number of transcription factors and secreted signalling molecules in sex determination, intracellular signalling components functioning in this process have not been defined. Here we report a role for the phylogenetically ancient mitogen-activated protein kinase (MAPK) signalling pathway in mouse sex determination. Using a forward genetic screen, we identified the recessive boygirl (byg) mutation. On the C57BL/6J background, embryos homozygous for byg exhibit consistent XY gonadal sex reversal. The byg mutation is an A to T transversion causing a premature stop codon in the gene encoding MAP3K4 (also known as MEKK4), a mitogen-activated protein kinase kinase kinase. Analysis of XY byg/byg gonads at 11.5 d post coitum reveals a growth deficit and a failure to support mesonephric cell migration, both early cellular processes normally associated with testis development. Expression analysis of mutant XY gonads at the same stage also reveals a dramatic reduction in Sox9 and, crucially, Sry at the transcript and protein levels. Moreover, we describe experiments showing the presence of activated MKK4, a direct target of MAP3K4, and activated p38 in the coelomic region of the XY gonad at 11.5 d post coitum, establishing a link between MAPK signalling in proliferating gonadal somatic cells and regulation of Sry expression. Finally, we provide evidence that haploinsufficiency for Map3k4 accounts for T-associated sex reversal (Tas). These data demonstrate that MAP3K4-dependent signalling events are required for normal expression of Sry during testis development, and create a novel

Determination of hyperin in seed of Cuscuta chinensis Lam. by enhanced chemiluminescence of CdTe quantum dots on calcein/K3Fe(CN)6 system.

Science.gov (United States)

Kang, Jing; Li, Xuwen; Geng, Jiayang; Han, Lu; Tang, Jieli; Jin, Yongri; Zhang, Yihua

2012-10-15

In this paper, 3-mercaptocarboxylic acid (MPA) modified CdTe quantum dots (QDs) were used as sensitizers, to enhance the chemiluminescence (CL) of the calcein/K(3)Fe(CN)(6) system. A new CL system of CdTe/calcein/K(3)Fe(CN)(6) was developed. The effects of reactant concentrations and the particle sizes of CdTe QDs on the CL emission were investigated in detail. The possible enhancement mechanism of the CL was also further investigated based on the photoluminescence (PL) and CL spectra. Polyphenols such as chlorogenic acid, quercetin, hyperin, catechin and kaempferol, were observed to inhibit the CL signal of the CdTe/calcein/K(3)Fe(CN)(6) system and determined by the proposed method. The proposed method was applied to the determination of hyperin in seed of Cuscuta chinensis Lam. and the results obtained were satisfactory. Copyright © 2012 Elsevier Ltd. All rights reserved.

Quantitative determination of minerals in Nevada Test Site samples by x-ray diffraction

International Nuclear Information System (INIS)

Pawloski, G.A.

1983-07-01

The external standard intensity ratio technique has been developed into a routine procedure for quantitatively determining mineralogic compositions of Nevada Test Site (NTS) samples by x-ray diffraction. This technique used ratios of x-ray intensity peaks from the same run which eliminates many possible errors. Constants have been determined for each of thirteen minerals commonly found in NTS samples - quartz, montmorillonite, illite, clinoptilolite, cristobalite, feldspars, calcite, dolomite, hornblende, kaolinite, muscovite, biotite, and amorphous glass. Ratios of the highest intensity peak of each mineral to be quantified in the sample and the highest intensity peak of quartz are used to calculate sample composition. The technique has been tested on samples with three to eleven components representative of geologic environments at NTS, and is accurate to 7.0 wt % of the total sample. The minimum amount of each of these minerals detectable by x-ray diffraction has also been determined. QUANTS is a computer code that calculates mineral contents and produces a report sheet. Constants for minerals in NTS samples other than those listed above can easily be determined, and added to QUANTS at any time

Construction of the KUT test pits

International Nuclear Information System (INIS)

Knapp, K.E.; Bush, W.E.

1976-09-01

Models are required to calibrate spectral logging systems to differentiate between U, Th, and K (''KUT''), in order to determine the grade of low-grade U deposits. The models were constructed by excavating three pits, emplacing three form tanks (11 ft long, 4 ft dia culvert) with 4-in. dia central holes, and pouring the following zones: 3-ft concrete lower barren zone, a 5-ft ore zone, and a final 3-ft upper barren zone. The U ore zone comprised 0.33 percent U 3 O 8 Climax ore, sand, cement, and water; the Th ore zone comprised monazite sands, plaster sand, cement, and water; and the K ore zone comprised feldspar, cement, and water. Form pipes were used to form the central holes. Analyses were made of samples taken from the zones

K-n and K-p elastic scattering in K-d collisions from 1.2 to 2.2 GeV/c

International Nuclear Information System (INIS)

Declais, Y.; Duchon, J.; Louvel, M.; Patry, J.-P.; Seguinot, J.; Baillon, P.; Bruman, C.; Ferro-Luzzi, M.; Perreau, J.-M.; Ypsilantis, T.

1977-01-01

This report contains the detailed description of an experiment which has determined the differential cross section of the K - n→K - n elastic scattering reaction. The results are 12 angular distributions spanning the K - n c.m. energy interval from approximately 1.86 to approximately 2.32 GeV. The measurements have been performed at the CERN PS using a beam of negative kaons with momenta from 1.2 to 2.2 GeV/c incident on a liquid deuterium target. By means of electronic apparatus the process K - d→K - n psub(s) was identified and recorded; this process is basically the same as the K - n elastic reaction insofar as the spectator proton psub(s) has low momentum. The elastic reaction was derived from the above process by taking into account the Fermi motion of the target neutron and by introducing the appropriate corrections to compensate for the effects due to the composite nature of the neutron (double-scattering, final state interaction). These results, constituting the first extensive collection of data on the pure isospin 1 anti KN state have been used in conjunction with other data in a preliminary partial wave analysis of the anti KN elastic system over the c.m. energy range from 1.84 to 2.23 GeV. Mainly for testing purposes, a similar amount of data has been collected for the K - p elastic reaction also from K - d collisions (K - d→K - p nsub(s)). (Auth.)

Phamacognostical Evaluation and Determination of Total Phenols of Paeonia sinjiangensis K. Y. Pan

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H. Y. Gong

2012-01-01

Full Text Available Paeonia sinjiangensis K. Y. Pan is a perennial herb belonging to the family Ranunculaceae which is one of the most important crude drugs in traditional Chinese medicine, used as an anti-inflammatory, analgesic and sedative agent. This paper deals with the detailed pharmacognostical evaluation of the crude drug P. sinjiangensis K. Y. Pan. The microscopic, physico-chemical, preliminary physicochemical parameters, total phenols contents presented in this paper may be proposed as parameters to establish the authenticity of P. sinjiangensis K. Y. Pan and can possibly help to differentiate the drug from its other species.

The determination of the inhalable fraction of 40K activity in marijuana (Cannabis sativa L. buds by instrumental neutron activation analysis and the effective dose to the body

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Johann M.R. Antoine

2017-07-01

Full Text Available Total potassium in marijuana (Cannabis sativa L. buds was determined using instrumental neutron activation analysis. The mass fraction of 40K and its activity were derived using the natural isotopic ratios of potassium. The total potassium in the marijuana buds ranged from 0.84% to 3.15% with a mean mass fraction of 1.93%. The activity concentrations of 40K in the samples of marijuana ranged from 253 to 946 Bq kg−1 with a mean activity concentration of 581 Bq kg−1. The effective dose to the body from smoking marijuana is lower than that for comparable tobacco smoking. Simulated smoking experiments show that over 90% of 40K is retained in the cigarette ash. Accepted methods of determining effective dose to the body from 40K inhalation are likely overestimations for both marijuana and tobacco cigarette smoke.

Experimental (155 K) and predicted (151 K) Curie temperature (Tc) of K2ZnBr4: structural confirmation of ferroelectric state below Tc

International Nuclear Information System (INIS)

Abrahams, S.C.

1994-01-01

The temperature T c at which K 2 ZnBr 4 is predicted to transform from the paraelectric to the ferroelectric phase is 151 (19) K, based on the crystal structure determinations at 291 and 144 K by Fabry, Breczewski, Zuniga and Arnaiz and the Abrahams-Kurtz-Jamieson relationship. A dielectric and heat-capacity anomaly in this material at 155 K has been reported elsewhere. The locations reported for the ZnBr 2- 4 and K + ions fulfill the requirements of mirror plane symmetry above T c ; ionic displacements along the polar direction that approach but do not exceed 0.1 A and that violate the mirror symmetry on cooling through T c form the basis of the prediction and satisfy the structural criteria for ferroelectricity in the phase below the transition. (orig.)

Determination of k{sub 0} for {sup 63}Cu(n,γ){sup 64}Cu reaction with covariance analysis

Energy Technology Data Exchange (ETDEWEB)

Barros, Livia F.; Dias, Mauro S.; Koskinas, Marina F.; Yamazaki, Ione M.; Semmler, Renato, E-mail: lfbarros@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

Nowadays the k{sub 0} Method is one of the most used procedures on Neutron Activation Analysis (NAA). For an element of interest, the parameter k{sub 0} can be used to determine its mass concentration. The recommended nuclear data has been investigated, and the measurement of this parameter for {sup 63}Cu(n,γ){sup 64}Cu reaction was motivated by some discrepancies that were observed in the literature. The irradiations were performed near the core of the IEA-R1 4.5 MW nuclear research reactor of the Nuclear and Energy Research Institute – IPEN-CNEN/SP, in São Paulo, Brazil. Two irradiations were carried out in sequence, using two sets of samples: the first one with a cadmium cover around the samples and the second one without it. The activity measurements were carried out in a previously calibrated HPGe gamma-ray spectrometer. Standard sources of {sup 152}Eu, {sup 133}Ba, {sup 60}Co and {sup 13}'7Cs supplied by the IAEA with gamma transitions ranging from 121 keV to 1408 keV were used in order to obtain the HPGe gamma-ray peak efficiency as a function of the energy. The covariance matrix methodology was applied to all uncertainties involved. The resulting value of k{sub 0} for {sup 63}Cu(n,γ){sup 64}Cu reaction for the gamma transition energy of the formed isotope {sup 64}Cu 1345.77 keV was 4.99 x 10{sup -4} (78).This final value for k{sub 0} has been compared with the literature. (author)

Platinum-group elements in the cores of potassium feldspar spherules from the Cretaceous-Tertiary boundary at Caravaca (Spain

Directory of Open Access Journals (Sweden)

Palomo, I.

1994-04-01

Full Text Available The abundant spherules present in the Cretaceous-Tertiary boundary layer at Caravaca are diagenetically transformed to potassium feldspar. Before our study no possible relicts of the precursor material had been reported. but in this paper we describe the presence of cores in these spherules that could represent a relict of the «unknown precursor». These cores are made up of C mixed with Si. Mg. AL Cr. Ca among other elements. Laser Ablation System analysis also reveals an enrichment in pe;E could suggest an extraterrestrial origin for this material. PI. Pd and Ir do not show a chondritic ratio: however. asevere modification of their concentration could be expected during the early diagenetic processes.Las esférulas existentes en la lámina de sedimento del tránsito Cretácico-Terciario de la sección de Caravaca han sido transformadas diagenéticamente a feldespato potásico. En este trabajo se describe la existencia de núcleos encontrados en el interior de las esférulas. los cuales' pueden representar relictos del material precursor. Dichos núcleos están constituidos por C. Si. Mg, AL Cr y Ca entre otros elementos. Se pone de relieve, por vez primera, su notable enriquecimiento en elementos del grupo del platino, cuyas relaciones no condríticas pueden ser debidas a la existencia de importantes modificaciones en su concentración inicial causadas por los procesos diagenéticos y por la existencia de materia orgánica.

A recalculation of the gravitational mass difference between the K0 and anti K0 mesons

International Nuclear Information System (INIS)

Kenyon, I.R.

1990-01-01

The method first applied by Good to determine the gravitational mass difference ΔM g between the K 0 and anti K 0 mesons is repeated using recent measurements of the parameters of neutral K meson decays and of the location and mass of the supergalactic centre. The ratio ΔM g /M≤2x10 -13 , which constitutes one of the severest tests of the weak equivalence principle. (orig.)

Determination of the branching fractions of $B_{s}^{0} \\to D_{s}^{\\mp} K^{\\pm}$ and $B^{0} \\to D_{s}^{-} K^{+}$

CERN Document Server

Aaij, Roel; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassen, Rolf; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Bel, Lennaert; Belogurov, Sergey; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bertolin, Alessandro; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Bizzeti, Andrea; Bjørnstad, Pål Marius; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Capriotti, Lorenzo; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casanova Mohr, Raimon; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pascal; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Dey, Biplab; Di Canto, Angelo; Di Domenico, Antonio; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fol, Philip; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gascon, David; Gaspar, Clara; Gastaldi, Ugo; Gauld, Rhorry; Gavardi, Laura; Gazzoni, Giulio; Geraci, Angelo; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, V.V.; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jawahery, Abolhassan; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Karodia, Sarah; Kelsey, Matthew; Kenyon, Ian; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Klimaszewski, Konrad; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lowdon, Peter; Lucchesi, Donatella; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Malinin, Alexander; Manca, Giulia; Mancinelli, Giampiero; Mapelli, Alessandro; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Moggi, Niccolò; Molina Rodriguez, Josue; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Katharina; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Nicol, Michelle; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Orlandea, Marius; Osorio Rodrigues, Bruno; Otalora Goicochea, Juan Martin; Otto, Adam; Owen, Patrick; Oyanguren, Maria Arantza; Pal, Bilas Kanti; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parkes, Christopher; Parkinson, Christopher John; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Pescatore, Luca; Pesen, Erhan; Petridis, Konstantin; Petrolini, Alessandro; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Quagliani, Renato; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruiz, Hugo; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skillicorn, Ian; Skwarnicki, Tomasz; Smith, Anthony; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Sterpka, Christopher Francis; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szumlak, Tomasz; T'Jampens, Stephane; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Todd, Jacob; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viana Barbosa, Joao Vitor; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Whitehead, Mark; Wiedner, Dirk; Wilkinson, Guy; Wilkinson, Michael; Williams, Matthew; Williams, Mike; Wilschut, Hans; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Wen Chao; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang

2015-01-01

Measurements are presented of the branching fractions of the decays $B_{s}^{0} \\to D_{s}^{\\mp} K^{\\pm}$ and $B^{0} \\to D_{s}^{-} K^{+}$ relative to the decays $B_{s}^{0} \\to D_{s}^{-} \\pi^{+}$ and $B^{0} \\to D^{-} \\pi^{+}$, respectively. The data used correspond to an integrated luminosity of 3.0 fb$^{-1}$ of proton-proton collisions. The ratios of branching fractions are $\\dfrac{\\mathcal{B}(B_{s}^{0} \\to D_{s}^{\\mp} K^{\\pm})}{\\mathcal{B}(B_{s}^{0} \\to D_{s}^{-} \\pi^{+})} = 0.0752 \\pm 0.0015 \\pm 0.0019$ and $\\dfrac{\\mathcal{B}(B^{0} \\to D_{s}^{-} K^{+})}{\\mathcal{B}(B^{0} \\to D^{-} \\pi^{+})} = 0.0129 \\pm 0.0005 \\pm 0.0008,$ where the uncertainties are statistical and systematic, respectively.

Age group and sex do not influence responses of vitamin K biomarkers to changes in dietary vitamin K.

Science.gov (United States)

Truong, Jennifer T; Fu, Xueyan; Saltzman, Edward; Al Rajabi, Ala; Dallal, Gerard E; Gundberg, Caren M; Booth, Sarah L

2012-05-01

Inadequate vitamin K intake has been associated with abnormal soft tissue calcification. Older adults may have insufficient intakes of vitamin K and respond less to vitamin K supplementation compared with younger adults. However, little is known about the determinants that influence the response to vitamin K supplementation. Our primary objective was to assess dietary and nondietary determinants of vitamin K status in healthy younger and older adults. In a nonrandomized, nonmasked study, 21 younger (18-40 y) and 21 older (55-80 y) men and women consumed a baseline diet (200 μg phylloquinone/d) for 5 d, a phylloquinone-restricted diet (10 μg phylloquinone/d) for 28 d, and a phylloquinone-supplemented diet (500 μg phylloquinone/d) for 28 d. Changes in vitamin K status markers in response to vitamin K depletion and repletion were studied and the influences of BMI, body fat, and circulating TG were assessed by including them as covariates in the model. Despite baseline differences in measures of vitamin K status, plasma phylloquinone tended to increase (P = 0.07) and the percentage of uncarboxylated osteocalcin and uncarboxylated prothrombin both improved with phylloquinone supplementation (P vitamin K metabolite, was greater among younger adults in response to depletion than in older adults (P = 0.012), regardless of sex. Adiposity measures and circulating TG did not predict response of any measures. In conclusion, poor vitamin K status can be similarly improved with vitamin K supplementation, regardless of age group or sex.

KEY COMPARISON: Final report on CCQM-K9.2: Subsequent key comparison on pH determination of phosphate buffer by Harned cell measurements

Science.gov (United States)

Spitzer, Petra; Giera, Janine; Fraga, Isabel C.; Tønnes Jakobsen, Pia; Jensen, Hans D.; Hyllested, Peter; Karpov, Oleg; Kutovoy, Viatcheslav; Nakamura, Susumu; Vospelova, Alena; Zvezdina, Valentina

2008-01-01

CCQM-K9.2 was performed supplementary to the key comparison CCQM-K9 on the pH determination of a phosphate buffer with nominal pH ~ 6.9 (at 25 °C). The sample composition was very similar in both comparisons. Only the source of the starting material used for sample preparation was different. The comparison was restricted to the use of the primary method for pH (Harned cell measurement) as defined in the IUPAC Recommendations [2]. The measurement temperatures were 15 °C, 25 °C, 37 °C. CCQM-K9.2, CCQM-K.9 and the first supplementary comparison CCQM-K9.1 [5] are activities of the Electrochemical Working Group (EAWG) of the CCQM. All three comparisons were coordinated by the PTB, Germany. The Danish Primary Laboratory (DPL) successfully took part in the CCQM-K9. Meanwhile the primary set-up for pH in Denmark moved from DPL affiliated to Radiometer Medical to DFM, Denmark. The subsequent comparison allows assessing the degree of equivalence for the measurement of pH at DFM after the move. Due to the interest of other laboratories in demonstrating their progress in pH measurements on the primary level the CCQM-K9.2 supplementary comparison was extended to other participants than DFM, namely NMIJ, VNIIFTRI, INMETRO and CMI. The reported quantity for CCQM-K9.2 was not the pH of the sample but the acidity function at zero chloride molality (see chapter 12). To calculate the pH value from the acidity function it is necessary to know the ionic strength of the sample buffer solution, which was undisclosed by the coordinator. With the exception of the Czech Metrology Institute, CMI, good agreement in the determined acidity function is found between the participants. The results reported by DFM and by PTB agree within their measurement uncertainty at all measurement temperatures. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report

Determination of toxic and trace elements in human hair and sediment samples by reactor neutron activation analysis technique based-on the k-zero method

International Nuclear Information System (INIS)

Ho Manh Dung; Nguyen Mong Sinh; Nguyen Thanh Binh; Cao Dong Vu; Nguyen Thi Si

2004-01-01

The analysis of human hair can evaluate the degree of environmental pollutants exposure to human body, intakes of food and metabolism. Also, the analysis of sediment can aid in reconstructing the history of changes, understanding human impact on the ecosystem, and suggesting possible remedial strategies. The k o -standardization method of neutron activation analysis (k o -NAA) on research reactor is capable to play an important role as a main analytical technique with the advantages of sensitivity, precision, accuracy, multielement and routine for the sample object. Therefore, the project's aim is to build the k o -NAA procedures on the Dalat research reactor for the analysis of human hair and sediment samples. The K o -NAA procedure on the Dalat research reactor is able to determine of multielement: Ag, Al, As, Br, Ca, Cl, Co, Cr, Cu, Fe, Hg, I, K Mg, Mn, Na, S, Sb, Se, Sr, Ti, V and Zn in The human hair; and of multielement: As, Co, Cr, Cs, Fe, Hf, K, La, Mn, Na Rb, Sb, Sc, Yb and Zn in the sediment. (author)

K2-60b and K2-107b. A Sub-Jovian and a Jovian Planet from the K2 Mission

International Nuclear Information System (INIS)

Eigmüller, Philipp; Csizmadia, Szilard; Smith, Alexis M. S.; Cabrera, Juan; Erikson, Anders; Gandolfi, Davide; Barragán, Oscar; Persson, Carina M.; Fridlund, Malcolm; Donati, Paolo; Cusano, Felice; Korth, Judith; Grziwa, Sascha; Prieto-Arranz, Jorge; Nespral, David; Deeg, Hans J.; Saario, Joonas; Cochran, William D.; Endl, Michael; Guenther, Eike W.

2017-01-01

We report the characterization and independent detection of K2-60b, as well as the detection and characterization of K2-107b, two transiting hot gaseous planets from the K2 space mission. We confirm the planetary nature of the two systems and determine their fundamental parameters combining the K2 time-series data with FIES@NOT and HARPS-N@TNG spectroscopic observations. K2-60b has a radius of 0.683 ± 0.037 R Jup and a mass of 0.426 ± 0.037 M Jup and orbits a G4 V star with an orbital period of 3.00267 ± 0.00006 days. K2-107b has a radius of 1.44 ± 0.15 R Jup and a mass of 0.84 ± 0.08 M Jup and orbits an F9 IV star every 3.31392 ± 0.00002 days. K2-60b is among the few planets at the edge of the so-called “desert” of short-period sub-Jovian planets. K2-107b is a highly inflated Jovian planet orbiting an evolved star about to leave the main sequence.

K2-60b and K2-107b. A Sub-Jovian and a Jovian Planet from the K2 Mission

Energy Technology Data Exchange (ETDEWEB)

Eigmüller, Philipp; Csizmadia, Szilard; Smith, Alexis M. S.; Cabrera, Juan; Erikson, Anders [Institute of Planetary Research, German Aerospace Center, Rutherfordstrasse 2, D-12489 Berlin (Germany); Gandolfi, Davide; Barragán, Oscar [Dipartimento di Fisica, Universitá di Torino, via P. Giuria 1, I-10125 Torino (Italy); Persson, Carina M.; Fridlund, Malcolm [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-439 92 Onsala (Sweden); Donati, Paolo; Cusano, Felice [INAF—Osservatorio Astronomico di Bologna, Via Ranzani, 1, I-40127, Bologna (Italy); Korth, Judith; Grziwa, Sascha [Rheinisches Institut für Umweltforschung an der Universität zu Köln, Aachener Strasse 209, D-50931 Köln (Germany); Prieto-Arranz, Jorge; Nespral, David; Deeg, Hans J. [Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife (Spain); Saario, Joonas [Nordic Optical Telescope, Apartado 474, E-38700, Santa Cruz de La Palma (Spain); Cochran, William D.; Endl, Michael [Department of Astronomy and McDonald Observatory, University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712 (United States); Guenther, Eike W. [Thüringer Landessternwarte Tautenburg, Sternwarte 5, D-07778 Tautenberg (Germany); and others

2017-03-01

We report the characterization and independent detection of K2-60b, as well as the detection and characterization of K2-107b, two transiting hot gaseous planets from the K2 space mission. We confirm the planetary nature of the two systems and determine their fundamental parameters combining the K2 time-series data with FIES@NOT and HARPS-N@TNG spectroscopic observations. K2-60b has a radius of 0.683 ± 0.037 R {sub Jup} and a mass of 0.426 ± 0.037 M {sub Jup} and orbits a G4 V star with an orbital period of 3.00267 ± 0.00006 days. K2-107b has a radius of 1.44 ± 0.15 R {sub Jup} and a mass of 0.84 ± 0.08 M {sub Jup} and orbits an F9 IV star every 3.31392 ± 0.00002 days. K2-60b is among the few planets at the edge of the so-called “desert” of short-period sub-Jovian planets. K2-107b is a highly inflated Jovian planet orbiting an evolved star about to leave the main sequence.

Determination of multi-element composition of Vietnamese marine sediment and tuna fish by k0-standardized neutron activation analysis

International Nuclear Information System (INIS)

Manh-Dung Ho; Quang-Thien Tran; Van-Doanh Ho; Thi-Sy Nguyen

2016-01-01

The k 0 -standardized neutron activation analysis (k 0 -NAA) has been applied for determination of multiple elements (25 elements: Al, As, Ba, Br, Ca, Cl, Co, Cr, Cs, Cu, Eu, Fe, Hg, K, La, Mg, Na, Rb, Sc, Se, Sm, Th, Ti, V and Zn) in marine sediment and tuna fish. About 50 marine sediment and 9 tuna fish samples were collected in two coastal areas of Vietnam. The health risk index (HRI) values of As and Br were higher than 1.0 for the tuna fish. Also, HRI value of Hg was 8.92 × 10 -1 indicating a relatively high potential health risk, whiles Co and Mn with HRIs = 1.56 × 10 -4 and 8.56 × 10 -4 , respectively, have the lowest potential health risks. Average enrichment factors using Al as a reference element (EF Al ) were higher than 1.5 for Eu, La, Zn, Th, Cs and As in which the highest EF Al value for As was higher than 10. This study showed that the HRI value of As in the tuna fish correlated positively with the EF Al value for the element in the marine sediment. (author)

Magmatic and petrologic evolution of the mesozvic vulcanic acid rocks from Piraju-Ourinhos region (SP-PR)

International Nuclear Information System (INIS)

Raposo, M.I.B.

1987-01-01

This work presents the result of geological, petrological and geochemical studies, on the volcanic rocks from Piraju-Ourinhos region, SP, with special emphasis on the rocks. A geological mapping was carried out by using images from Landsat satellite. Petrographic and chemical analyses have defined a suite represented by basic lithotype - tholeutic andesibasalt - with high TiO 2 , rich in incompable elements - mainly Sr, Zr, La, Ce, and Ba - and by acid lithotype - rhyolite - rhyodacite. k-Ar ages are determined in feldspar concentrated, and indicate an age of 133+- 4m,y, for the volcanic acid rocks. Determinations of Sr isotopes. In order to explain the genesis of Chapeco type acid magnas quantitative models were tested using both fractional Crystallization [pt

Torsion in a gravity theory with SO(k) x SO(d-k) as tangent group

International Nuclear Information System (INIS)