SEEDisCs: How Clusters Form and Galaxies Transform in the Cosmic Web

Science.gov (United States)

Jablonka, P.

2017-08-01

This presentation introduces a new survey, the Spatial Extended EDisCS Survey (SEEDisCS), which aims at understanding how clusters assemble and the level at which galaxies are preprocessed before falling on the cluster cores. I focus on the changes in galaxy properties in the cluster large scale environments, and how we can get constraints on the timescale of star formation quenching. I also discuss new ALMA CO observations, which trace the fate of the galaxy cold gas content along the infalling paths towards the cluster cores.

Technetium in late-type stars. I. Observations

International Nuclear Information System (INIS)

Little-Marenin, I.R.; Little, S.J.

1979-01-01

An analysis of about 90 spectra (11 or 13A/mm) of nonvariable and variable (mostly Mira variables) M, MS, S, CS, and C stars for the presence of the radioactive element technetium (T/sub 1/2/approx. =2 x 10 5 y) suggests that Tc is most often present at certain variability periods. Stars with no Tc I lines in their spectra can be found at most periods (P-bar=234/sup d/), whereas stars with Tc I lines have periods in most cases in excess of 300 days (P-bar=330/sup d/ +- 83/sup d/). Interpreting our data in terms of kinematic studies by Feast (1963) suggests that the stars with Tc are Pop I and that variables without Tc are largely Pop II type stars

{sup 137}Cs in a raised bog in central Sweden

Energy Technology Data Exchange (ETDEWEB)

Rosen, K. [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, Ulls vag 17, Box 7014, SE-75007, Uppsala (Sweden)], E-mail: klas.rosen@mv.slu.se; Vinichuk, M. [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, Ulls vag 17, Box 7014, SE-75007, Uppsala (Sweden); Department of Ecology, Zhytomyr State Technological University, 103 Cherniakhovsky Str., 10005 Zhytomyr (Ukraine); Johanson, K.J. [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, Ulls vag 17, Box 7014, SE-75007, Uppsala (Sweden)

2009-07-15

The vertical distribution of {sup 137}Cs activity in peat soil profiles and {sup 137}Cs activity concentration in plants of various species was studied in samples collected at two sites on a raised bog in central Sweden. One site (open bog) was in an area with no trees and only a few sparsely growing plant species, while the other (low pine) was less than 100 m from the open bog site and had slowly growing Scots pine, a field layer dominated by some ericaceous plants and ground well-covered by plants. The plant samples were collected in 2004-2007 and were compared with samples collected in 1989 from the same open bog and low pine sites. Ground deposition of {sup 137}Cs in 2005 was similar at both sites, 23 000 Bq m{sup -2}. In the open bog peat profile it seems to be an upward transport of caesium since a clear peak of {sup 137}Cs activity was found in the uppermost 1-4 cm of Sphagnum layers, whereas at the low pine site {sup 137}Cs was mainly found in deeper (10-12 cm) layers. The migration rate was 0.57 cm yr{sup -1} at the open bog site and the migration centre of {sup 137}Cs was at a depth of 10.7, while the rate at the low pine site was 0.78 cm yr{sup -1} and the migration centre was at 14.9 cm. Heather (Calluna vulgaris) was the plant species with the highest {sup 137}Cs activity concentrations at both sites, 43.5 k Bq{sup -1} DM in 1989 decreasing to 20.4 in 2004-2007 on open bog and 22.3 k Bq kg{sup -1} DM in 1989 decreasing to 11.2 k Bq{sup -1} DM by the period 2004-2007 on the low pine site. {sup 137}Cs transfer factors in plants varied between 0.88 and 1.35 on the open bog and between 0.48 and 0.69 m{sup 2} kg{sup -1} DM at the low pine site.

Growth and (137)Cs uptake of four Brassica species influenced by inoculation with a plant growth-promoting rhizobacterium Bacillus pumilus in three contaminated farmlands in Fukushima prefecture, Japan.

Science.gov (United States)

Aung, Han Phyo; Djedidi, Salem; Oo, Aung Zaw; Aye, Yi Swe; Yokoyama, Tadashi; Suzuki, Sohzoh; Sekimoto, Hitoshi; Bellingrath-Kimura, Sonoko Dorothea

2015-07-15

The effectiveness of the plant growth-promoting rhizobacterium Bacillus pumilus regarding growth promotion and radiocesium ((137)Cs) uptake was evaluated in four Brassica species grown on different (137)Cs contaminated farmlands at Fukushima prefecture in Japan from June to August 2012. B. pumilus inoculation did not enhance growth in any of the plants, although it resulted in a significant increase of (137)Cs concentration and higher (137)Cs transfer from the soil to plants. The Brassica species exhibited different (137)Cs uptake abilities in the order Komatsuna>turnip>mustard>radish. TF values of (137)Cs ranged from 0.018 to 0.069 for all vegetables. Komatsuna possessed the largest root surface area and root volume, and showed a higher (137)Cs concentration in plant tissue and higher (137)Cs TF values (0.060) than the other vegetables. Higher (137)Cs transfer to plants was prominent in soil with a high amount of organic matter and an Al-vermiculite clay mineral type. Copyright © 2015 Elsevier B.V. All rights reserved.

Rejuvenation of the Innocent Bystander: Testing Spin-Up in Dwarf Carbon Stars

Science.gov (United States)

Green, Paul

2013-09-01

Carbon stars (C>O) were long assumed to all be giants, because only AGB stars dredge up significant carbon into their atmospheres. We now know that dwarf carbon (dC) stars are actually far more common than C giants. These dCs are hypothesized to have accreted C-rich envelope material from an AGB companion, in systems that have likely undergone a planetary nebula phase, eventually yielding a white dwarf and a dC that has gained both significant mass and angular momentum. To test whether the X-ray emission strength and spectral properties are consistent with a rejuvenated dynamo, we propose a Chandra pilot study of dCs selected from the SDSS; some have hot white dwarf companions (indicating more recent mass transfer), and all show Balmer emission lines (a sign of activity).

CS Informativeness Governs CS-US Associability

Science.gov (United States)

Ward, Ryan D.; Gallistel, C. R.; Jensen, Greg; Richards, Vanessa L.; Fairhurst, Stephen; Balsam, Peter D

2012-01-01

In a conditioning protocol, the onset of the conditioned stimulus (CS) provides information about when to expect reinforcement (the US). There are two sources of information from the CS in a delay conditioning paradigm in which the CS-US interval is fixed. The first depends on the informativeness, the degree to which CS onset reduces the average expected time to onset of the next US. The second depends only on how precisely a subject can represent a fixed-duration interval (the temporal Weber fraction). In three experiments with mice, we tested the differential impact of these two sources of information on rate of acquisition of conditioned responding (CS-US associability). In Experiment 1, we show that associability (the inverse of trials to acquisition) increases in proportion to informativeness. In Experiment 2, we show that fixing the duration of the US-US interval or the CS-US interval or both has no effect on associability. In Experiment 3, we equated the increase in information produced by varying the C̅/T̅ ratio with the increase produced by fixing the duration of the CS-US interval. Associability increased with increased informativeness, but, as in Experiment 2, fixing the CS-US duration had no effect on associability. These results are consistent with the view that CS-US associability depends on the increased rate of reward signaled by CS onset. The results also provide further evidence that conditioned responding is temporally controlled when it emerges. PMID:22468633

The Role of Gender in Asking Questions at Cool Stars 18 and 19

OpenAIRE

Schmidt, Sarah J.; Douglas, Stephanie; Gosnell, Natalie M.; Muirhead, Philip S.; Booth, Rachel S.; Davenport, James R. A.; Mace, Gregory N.

2017-01-01

We examine the gender balance of the 18th and 19th meetings of the Cambridge Workshop on Cool Stellar Systems and the Sun (CS18 and CS19). The percent of female attendees at both meetings (31% at CS18 and 37% at CS19) was higher than the percent of women in the American Astronomical Society (25%) and the International Astronomical Union (18%). The representation of women in Cool Stars as SOC members, invited speakers, and contributed speakers was similar to or exceeded the percent of women at...

Molecular structures and thermodynamic properties of 12 gaseous cesium-containing species of nuclear safety interest: Cs 2, CsH, CsO, Cs 2O, CsX, and Cs 2X 2 (X = OH, Cl, Br, and I)

Science.gov (United States)

Badawi, Michael; Xerri, Bertrand; Canneaux, Sébastien; Cantrel, Laurent; Louis, Florent

2012-01-01

Ab initio electronic structure calculations at the coupled cluster level with a correction for the triples extrapolated to the complete basis set limit have been made for the estimation of the thermochemical properties of Cs 2, CsH, CsO, Cs 2O, CsX, and Cs 2X 2 (X = OH, Cl, Br, and I). The standard enthalpies of formation and standard molar entropies at 298 K, and the temperature dependence of the heat capacities at constant pressure were evaluated. The calculated thermochemical properties are in good agreement with their literature counterparts. For Cs 2, CsH, CsOH, Cs 2(OH) 2, CsCl, Cs 2Cl 2, CsBr, CsI, and Cs 2I 2, the calculated ΔfH298K∘ values are within chemical accuracy of the most recent experimental values. Based on the excellent agreement observed between our calculated ΔfH298K∘ values and their literature counterparts, the standard enthalpies of formation at 298 K are estimated to be the following: ΔfH298K∘ (CsO) = 17.0 kJ mol -1 and ΔfH298K∘ (Cs 2Br 2) = -575.4 kJ mol -1.

CRL 2688: A post-carbon-star object and probable planetary nebula progenitor

International Nuclear Information System (INIS)

Zuckerman, B.; Gilra, D.P.; Turner, B.E.; Morris, M.; Palmer, P.

1976-01-01

Millimeter-wavelength emission is observed toward CRL 2688 from H 12 CN, H 13 CN, CS, and HC 3 N. The similarity of this emission and that from the molecular envelope of the carbon star IRC+10216 establishes, beyond a reasonable doubt, that CRL 2688 is a post--carbon-star object. It appears probable that both of these objects will evolve into planetary nebulae. An evolutionary sequence leading from carbon stars to planetary nebulae is outlined

Study of the Quantum Efficiency of CsI Photocathodes Exposed to Oxygen and Water Vapour

CERN Document Server

Di Mauro, A; Piuz, François; Schyns, E M; Van Beelen, J B; Williams, T D

2000-01-01

The operation of CsI photocathodes in gaseous detectors requires special attention to the purity of the applied gas mixtures.We have studied the influence of oxygen and water vapour contaminations on the performance of CsI photocathodes for theALICE HMPID RICH prototype. Measurements were done through comparison of Cherenkov rings obtained from beamtests. Increased levels of oxygen and water vapour did not show any effect on the performance. The results of this studyfound a direct application in the way of storing CsI photocathodes over long periods nad in particular in the shipment of theHMPID prototype from CERN to the STAR experiment at BNL. (Abstract only available,full text to follow)

Masses of the Planetary Nebula Central Stars in the Galactic Globular Cluster System from HST Imaging and Spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Jacoby, George H. [Lowell Observatory, Flagstaff, AZ 86001 (United States); Marco, Orsola De [Department of Physics and Astronomy, Macquarie University, Sydney, NSW 2109 (Australia); Davies, James [Space Telescope Science Institute, Baltimore MD 21218 (United States); Lotarevich, I. [American Museum of Natural History, New York, NY (United States); Bond, Howard E. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Harrington, J. Patrick [University of Maryland, College Park, MD (United States); Lanz, Thierry, E-mail: gjacoby@lowell.edu, E-mail: orsola.demarco@mq.edu.au, E-mail: jdavies@stsci.edu, E-mail: heb11@psu.edu, E-mail: jph@astro.umd.edu, E-mail: thierry.lanz@oca.eu [Laboratoire Lagrange, Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, F-06304 Nice (France)

2017-02-10

The globular cluster (GC) system of our Galaxy contains four planetary nebulae (PNe): K 648 (or Ps 1) in M15, IRAS 18333-2357 in M22, JaFu 1 in Pal 6, and JaFu 2 in NGC 6441. Because single-star evolution at the low stellar mass of present-epoch GCs was considered incapable of producing visible PNe, their origin presented a puzzle. We imaged the PN JaFu 1 with the Hubble Space Telescope (HST) to obtain photometry of its central star (CS) and high-resolution morphological information. We imaged IRAS 18333-2357 with better depth and resolution, and we analyzed its archival HST spectra to constrain its CS temperature and luminosity. All PNe in Galactic GCs now have quality HST data, allowing us to improve CS mass estimates. We find reasonably consistent masses between 0.53 and 0.58 M {sub ⊙} for all four objects, though estimates vary when adopting different stellar evolutionary calculations. The CS mass of IRAS 18333-2357, though, depends strongly on its temperature, which remains elusive due to reddening uncertainties. For all four objects, we consider their CS and nebula masses, their morphologies, and other incongruities to assess the likelihood that these objects formed from binary stars. Although generally limited by uncertainties (∼0.02 M {sub ⊙}) in post-AGB tracks and core mass versus luminosity relations, the high-mass CS in K 648 indicates a binary origin. The CS of JaFu 1 exhibits compact, bright [O iii] and H α emission, like EGB 6, suggesting a binary companion or disk. Evidence is weaker for a binary origin of JaFu 2.

Growth and {sup 137}Cs uptake of four Brassica species influenced by inoculation with a plant growth-promoting rhizobacterium Bacillus pumilus in three contaminated farmlands in Fukushima prefecture, Japan

Energy Technology Data Exchange (ETDEWEB)

Aung, Han Phyo [United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Saiwaicho 3-5-8, Fuchu, Tokyo 183-8509 (Japan); Djedidi, Salem; Oo, Aung Zaw [Institute of Agriculture, Tokyo University of Agriculture and Technology, Saiwaicho 3-5-8, Fuchu, Tokyo 183-8509 (Japan); Aye, Yi Swe [Department of International Environmental and Agricultural Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Saiwaicho 3-5-8, Fuchu, Tokyo 183-8509 (Japan); Yokoyama, Tadashi; Suzuki, Sohzoh [Institute of Agriculture, Tokyo University of Agriculture and Technology, Saiwaicho 3-5-8, Fuchu, Tokyo 183-8509 (Japan); Sekimoto, Hitoshi [Faculty of Agriculture, Utsunomiya University, 321-8505 (Japan); Bellingrath-Kimura, Sonoko Dorothea, E-mail: skimura@cc.tuat.ac.jp [Institute of Agriculture, Tokyo University of Agriculture and Technology, Saiwaicho 3-5-8, Fuchu, Tokyo 183-8509 (Japan)

2015-07-15

The effectiveness of the plant growth-promoting rhizobacterium Bacillus pumilus regarding growth promotion and radiocesium ({sup 137}Cs) uptake was evaluated in four Brassica species grown on different {sup 137}Cs contaminated farmlands at Fukushima prefecture in Japan from June to August 2012. B. pumilus inoculation did not enhance growth in any of the plants, although it resulted in a significant increase of {sup 137}Cs concentration and higher {sup 137}Cs transfer from the soil to plants. The Brassica species exhibited different {sup 137}Cs uptake abilities in the order Komatsuna > turnip > mustard > radish. TF values of {sup 137}Cs ranged from 0.018 to 0.069 for all vegetables. Komatsuna possessed the largest root surface area and root volume, and showed a higher {sup 137}Cs concentration in plant tissue and higher {sup 137}Cs TF values (0.060) than the other vegetables. Higher {sup 137}Cs transfer to plants was prominent in soil with a high amount of organic matter and an Al-vermiculite clay mineral type. - Highlights: • PGPR inoculation did not enhance plant biomass of tested plants. • PGPR inoculation resulted in higher {sup 137}Cs concentration in plants. • Komatsuna that had larger root volume showed higher {sup 137}Cs TF from soil to plants. • Soil with high SOM and Al-vermiculite caused larger {sup 137}Cs transfer to plants.

MAPPING THE LINEARLY POLARIZED SPECTRAL LINE EMISSION AROUND THE EVOLVED STAR IRC+10216

Energy Technology Data Exchange (ETDEWEB)

Girart, J. M. [Institut de Ciencies de l' Espai, (CSIC-IEEC), Campus UAB, Facultat de Ciencies, C5p 2, 08193 Bellaterra, Catalunya (Spain); Patel, N. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Vlemmings, W. H. T. [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-439 92 Onsala (Sweden); Rao, Ramprasad, E-mail: girart@ice.cat [Submillimeter Array, Academia Sinica Institute of Astronomy and Astrophysics, 645 N. Aohoku Place, Hilo, HI 96720 (United States)

2012-05-20

We present spectro-polarimetric observations of several molecular lines obtained with the Submillimeter Array toward the carbon-rich asymptotic giant branch star IRC+10216. We have detected and mapped the linear polarization of the CO 3-2, SiS 19-18, and CS 7-6 lines. The polarization arises at a distance of {approx_equal} 450 AU from the star and is blueshifted with respect to the Stokes I. The SiS 19-18 polarization pattern appears to be consistent with a locally radial magnetic field configuration. However, the CO 3-2 and CS 7-6 line polarization suggests an overall complex magnetic field morphology within the envelope. This work demonstrates the feasibility of using spectro-polarimetric observations to carry out tomographic imaging of the magnetic field in circumstellar envelopes.

Antibodies derived from an enterotoxigenic Escherichia coli (ETEC) adhesin tip MEFA (multiepitope fusion antigen) against adherence of nine ETEC adhesins: CFA/I, CS1, CS2, CS3, CS4, CS5, CS6, CS21 and EtpA.

Science.gov (United States)

Nandre, Rahul M; Ruan, Xiaosai; Duan, Qiangde; Sack, David A; Zhang, Weiping

2016-06-30

Diarrhea continues to be a leading cause of death in children younger than 5 years in developing countries. Enterotoxigenic Escherichia coli (ETEC) is a leading bacterial cause of children's diarrhea and travelers' diarrhea. ETEC bacteria initiate diarrheal disease by attaching to host receptors at epithelial cells and colonizing in small intestine. Therefore, preventing ETEC attachment has been considered the first line of defense against ETEC diarrhea. However, developing vaccines effectively against ETEC bacterial attachment encounters challenge because ETEC strains produce over 23 immunologically heterogeneous adhesins. In this study, we applied MEFA (multiepitope fusion antigen) approach to integrate epitopes from adhesin tips or adhesive subunits of CFA/I, CS1, CS2, CS3, CS4, CS5, CS6, CS21 and EtpA adhesins and to construct an adhesin tip MEFA peptide. We then examined immunogenicity of this tip MEFA in mouse immunization, and assessed potential application of this tip MEFA for ETEC vaccine development. Data showed that mice intraperitoneally immunized with this adhesin tip MEFA developed IgG antibody responses to all nine ETEC adhesins. Moreover, ETEC and E. coli bacteria expressing these nine adhesins, after incubation with serum of the immunized mice, exhibited significant reduction in attachment to Caco-2 cells. These results indicated that anti-adhesin antibodies induced by this adhesin tip MEFA blocked adherence of the most important ETEC adhesins, suggesting this multivalent tip MEFA may be useful for developing a broadly protective anti-adhesin vaccine against ETEC diarrhea. Copyright © 2016 Elsevier Ltd. All rights reserved.

Analysis of 137Cs radionuclides activities in Cs-zeolite using gamma spectrometry

International Nuclear Information System (INIS)

Noviarty; Ginting, Aslina Br; Anggraini, Dian; Rosika K

2013-01-01

137 Cs Radionuclide activity analysis has been carried out. The objective is to determine the activity of the 137 Cs radionuclide in Cs-zeolite are packaged in the form of point source. Analysis of 137 Cs Radionuclide activities in Cs zeolite samples was determined by measuring intensity of the isotope 137 Cs gamma energy at 661.7 keV use-y spectrometer. Before measurement the sample, was first carried out measurements of 137 Cs radionuclide in certified point standards from Amersham, to determine the efficiency value. Result the standard sample measurement obtained the efficiency value of 43.98%. Efficiency values obtained are used in the calculation of sample activity. On the measurement of the intensity of the sample obtained results dose rate 196.4537 cps with a standard deviation of 0.5274. By using standard measurement efficiency values obtained by the calculation of the average activity of the radionuclide 137 Cs in Cs-zeolite 524.9082 Bq. Deviation measurements were below 5% (0.27% ) so that the analysis of the activity of radionuclide 137 Cs in Cs-zeolite samples using gamma spectrometer can be accepted with a 95% confidence level. (author)

Molecular Cloud Structures and Massive Star Formation in N159

Science.gov (United States)

Nayak, O.; Meixner, M.; Fukui, Y.; Tachihara, K.; Onishi, T.; Saigo, K.; Tokuda, K.; Harada, R.

2018-02-01

The N159 star-forming region is one of the most massive giant molecular clouds (GMCs) in the Large Magellanic Cloud (LMC). We show the 12CO, 13CO, CS molecular gas lines observed with ALMA in N159 west (N159W) and N159 east (N159E). We relate the structure of the gas clumps to the properties of 24 massive young stellar objects (YSOs) that include 10 newly identified YSOs based on our search. We use dendrogram analysis to identify properties of the molecular clumps, such as flux, mass, linewidth, size, and virial parameter. We relate the YSO properties to the molecular gas properties. We find that the CS gas clumps have a steeper size–linewidth relation than the 12CO or 13CO gas clumps. This larger slope could potentially occur if the CS gas is tracing shocks. The virial parameters of the 13CO gas clumps in N159W and N159E are low (<1). The threshold for massive star formation in N159W is 501 M ⊙ pc‑2, and the threshold for massive star formation in N159E is 794 M ⊙ pc‑2. We find that 13CO is more photodissociated in N159E than N159W. The most massive YSO in N159E has cleared out a molecular gas hole in its vicinity. All the massive YSO candidates in N159E have a more evolved spectral energy distribution type in comparison to the YSO candidates in N159W. These differences lead us to conclude that the giant molecular cloud complex in N159E is more evolved than the giant molecular cloud complex in N159W.

'Wash-out' of Cs-134 and Cs-137 from river sediment; 'Ispiranja' Cs-134 i Cs-137 iz recnog sedimenta

Energy Technology Data Exchange (ETDEWEB)

Skrbic, Z; Conkic, Lj; Bikit, I; Veskovic, M; Slivka, J; Marinkov, L [Institut za Fiziku, Novi Sad Univ. (Yugoslavia)

1988-07-01

Natural elimination and 'wash out' period of the Cs-134 and Cs-137 from the river sediment has been investigated. Obtained results suggest the possibility to describe these processes by exponential low and determination of the corresponding half lives. (author)

Uptake and distribution of 137Cs, stable Cs and K in rice plants

International Nuclear Information System (INIS)

Tsukada, Hirofumi; Hasegawa, Hidenao

2003-01-01

The uptake and distributions of 137 Cs, stable Cs and K were determined for rice plant components, including polished rice, rice bran, hulls, leaves, stems, and roots. The distribution of 137 Cs in polished rice and rice bran was similar to that of stable Cs, while that of K was different. The concentration ratios of Cs/K in leaves increased in older leaf blade positions, which meant that the translocation rate of stable Cs, was slower than that of K. At harvest the dry weight of polished rice accounted for 34% of the entire rice plant, while the distributions of stable Cs in the polished rice and the non-edible parts were 7 and 93%, respectively. These findings suggest that the transfer and distribution of stable Cs in rice plants are different from those of K, and the behavior of stable Cs provides a useful analogue in predicting the fate of 137 Cs in an agricultural environment. (author)

135Cs activity and 135Cs/137Cs atom ratio in environmental samples before and after the Fukushima Daiichi Nuclear Power Plant accident.

Science.gov (United States)

Yang, Guosheng; Tazoe, Hirofumi; Yamada, Masatoshi

2016-04-07

(135)Cs/(137)Cs is a potential tracer for radiocesium source identification. However, due to the challenge to measure (135)Cs, there were no (135)Cs data available for Japanese environmental samples before the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. It was only 3 years after the accident that limited (135)Cs values could be measured in heavily contaminated environmental samples. In the present study, activities of (134)Cs, (135)Cs, and (137)Cs, along with their ratios in 67 soil and plant samples heavily and lightly contaminated by the FDNPP accident were measured by combining γ spectrometry with ICP-MS/MS. The arithmetic means of the (134)Cs/(137)Cs activity ratio (1.033 ± 0.006) and (135)Cs/(137)Cs atom ratio (0.334 ± 0.005) (decay corrected to March 11, 2011), from old leaves of plants collected immediately after the FDNPP accident, were confirmed to represent the FDNPP derived radiocesium signature. Subsequently, for the first time, trace (135)Cs amounts before the FDNPP accident were deduced according to the contribution of global and FDNPP accident-derived fallout. Apart from two soil samples with a tiny global fallout contribution, contributions of global fallout radiocesium in other soil samples were observed to be 0.338%-52.6%. The obtained (135)Cs/(137)Cs database will be useful for its application as a geochemical tracer in the future.

Co-intercalation of Mg(2+) and Na(+) in Na(0.69)Fe2(CN)6 as a High-Voltage Cathode for Magnesium Batteries.

Science.gov (United States)

Kim, Dong-Min; Kim, Youngjin; Arumugam, Durairaj; Woo, Sang Won; Jo, Yong Nam; Park, Min-Sik; Kim, Young-Jun; Choi, Nam-Soon; Lee, Kyu Tae

2016-04-06

Thanks to the advantages of low cost and good safety, magnesium metal batteries get the limelight as substituent for lithium ion batteries. However, the energy density of state-of-the-art magnesium batteries is not high enough because of their low operating potential; thus, it is necessary to improve the energy density by developing new high-voltage cathode materials. In this study, nanosized Berlin green Fe2(CN)6 and Prussian blue Na(0.69)Fe2(CN)6 are compared as high-voltage cathode materials for magnesium batteries. Interestingly, while Mg(2+) ions cannot be intercalated in Fe2(CN)6, Na(0.69)Fe2(CN)6 shows reversible intercalation and deintercalation of Mg(2+) ions, although they have the same crystal structure except for the presence of Na(+) ions. This phenomenon is attributed to the fact that Mg(2+) ions are more stable in Na(+)-containing Na(0.69)Fe2(CN)6 than in Na(+)-free Fe2(CN)6, indicating Na(+) ions in Na(0.69)Fe2(CN)6 plays a crucial role in stabilizing Mg(2+) ions. Na(0.69)Fe2(CN)6 delivers reversible capacity of approximately 70 mA h g(-1) at 3.0 V vs Mg/Mg(2+) and shows stable cycle performance over 35 cycles. Therefore, Prussian blue analogues are promising structures for high-voltage cathode materials in Mg batteries. Furthermore, this co-intercalation effect suggests new avenues for the development of cathode materials in hybrid magnesium batteries that use both Mg(2+) and Na(+) ions as charge carriers.

Activity standardization of 134Cs and 137Cs

International Nuclear Information System (INIS)

Sochorová, Jana; Auerbach, Pavel

2014-01-01

The paper presents the results from a primary standardization of 137 Cs using two independent methods – efficiency tracing using PC-NaI coincidence and the TDCR method. The nuclides 60 Co and 134 Cs were used as the tracers. Primary standardization of the 134 Cs is also discussed. The efficiency extrapolation was carried out by measuring samples of varying mass and using the wet extrapolation method. The results obtained are in good agreement; the differences did not exceed 0.5%. The advantages, pitfalls and also possibilities for improvement of the procedures are discussed

Determination of Cs-134 and Cs-137 rain water samples

International Nuclear Information System (INIS)

Lima, M.F.; Mazzilli, B.

1988-01-01

In order to setting an environmental monitoring program at IPEN, was developed a fast and simple methodology for concentration of Cs-134 and Cs-137 in rain water. This procedure consists in the precipitation of cesium and others cathions of its family (NH 4 + , K + and Rb + ) by ammonium molybdophosphate. The measures of the desintegration rates of Cs-134 and Cs-137 was done by gamma spectrometry in a Ge(Li) detector. After setting up the ideal experimental conditions, the procedure was used to analyze four samples of rain water. (author) [pt

Determination of soil-to-plant transfer factors of {sup 137}Cs and {sup 90}Sr in the tropical environment of Bangladesh

Energy Technology Data Exchange (ETDEWEB)

Mollah, A.S.; Begum, A. [Atomic Energy Research Establishment (AERE), Savar, Dacca (Bangladesh); Ullah, S.M. [University of Dhaka (Bangladesh). Department of Soil Science

1998-07-01

Soil-to-plant transfer factors (TF) of {sup 137}Cs and {sup 90}Sr have been determined for different plants/crops, such as rice, beans, peanuts, pineapple, cabbage, tomato, spinach and grass. They were obtained from radioisotope experiments on plants grown in pots under outdoor ambient tropical conditions for three growing seasons (1994-1996). In the case of {sup 137}Cs and concerning the above mentioned plants/crops, the average TFs were found to be 0.28, 0.25, 0.77, 0.19, 0.23, 0.28, 0.59 and 0.18, respectively. In the case of {sup 90}Sr, the average TFs were found to be 0.82, 0.51, 0.20, 0.82, 0.69, 0.59, 0.91 and 0.84, respectively. A minor seasonal variation was observed. This study provides a database of TFs for tropical environments to be used, e.g., for radiological safety assessment models. (orig.) With 1 fig., 3 tabs., 12 refs.

Determination of {sup 135}Cs and {sup 137}Cs in environmental samples: A review

Energy Technology Data Exchange (ETDEWEB)

Russell, B.C., E-mail: ben.russell@npl.co.uk [GAU-Radioanalytical, Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, SO14 3ZH (United Kingdom); National Physical Laboratory, Hampton Road, Teddington, Middlesex, TW11 0LW (United Kingdom); Croudace, Ian W.; Warwick, Phil E. [GAU-Radioanalytical, Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, SO14 3ZH (United Kingdom)

2015-08-26

Radionuclides of caesium are environmentally important since they are formed as significant high yield fission products ({sup 135}Cs and {sup 137}Cs) and activation products ({sup 134}Cs and {sup 136}Cs) during nuclear fission. They originate from a range of nuclear activities such as weapons testing, nuclear reprocessing and nuclear fuel cycle discharges and nuclear accidents. Whilst {sup 137}Cs, {sup 134}Cs and {sup 136}Cs are routinely measurable at high sensitivity by gamma spectrometry, routine detection of long-lived {sup 135}Cs by radiometric methods is challenging. This measurement is, however, important given its significance in long-term nuclear waste storage and disposal. Furthermore, the {sup 135}Cs/{sup 137}Cs ratio varies with reactor, weapon and fuel type, and accurate measurement of this ratio can therefore be used as a forensic tool in identifying the source(s) of nuclear contamination. The shorter-lived activation products {sup 134}Cs and {sup 136}Cs have a limited application but provide useful early information on fuel irradiation history and have importance in health physics. Detection of {sup 135}Cs (and {sup 137}Cs) is achievable by mass spectrometric techniques; most commonly inductively coupled plasma mass spectrometry (ICP-MS), as well as thermal ionisation (TIMS), accelerator (AMS) and resonance ionisation (RIMS) techniques. The critical issues affecting the accuracy and detection limits achievable by this technique are effective removal of barium to eliminate isobaric interferences arising from {sup 135}Ba and {sup 137}Ba, and elimination of peak tailing of stable {sup 133}Cs on {sup 135}Cs. Isobaric interferences can be removed by chemical separation, most commonly ion exchange chromatography, and/or instrumental separation using an ICP-MS equipped with a reaction cell. The removal of the peak tailing interference is dependent on the instrument used for final measurement. This review summarizes and compares the analytical procedures

Rejuvenation of the Innocent Bystander: Testing Spin-Up in a Dwarf Carbon Star Sample

Science.gov (United States)

Green, Paul

2014-09-01

Carbon stars (C>O) were long assumed to all be giants, because only AGB stars dredge up significant carbon into their atmospheres. We now know that dwarf carbon (dC) stars are actually far more common than C giants. These dC stars are hypothesized to have accreted C-rich envelope material from an AGB companion, in systems that have likely undergone a planetary nebula phase, eventually yielding a white dwarf and a dC star that has gained both significant mass and angular momentum. To test whether the X-ray emission strength and spectral properties are consistent with a rejuvenated dynamo, we propose a Chandra pilot study of dCs selected from the SDSS; some have hot white dwarf companions (indicating more recent mass transfer), and all show Balmer emission lines (a sign of activity).

High-mass twins & resolution of the reconfinement, masquerade and hyperon puzzles of compact star interiors

International Nuclear Information System (INIS)

Blaschke, David; Alvarez-Castillo, David E.

2016-01-01

We aim at contributing to the resolution of three of the fundamental puzzles related to the still unsolved problem of the structure of the dense core of compact stars (CS): (i) the hyperon puzzle: how to reconcile pulsar masses of 2 M ⊙ with the hyperon softening of the equation of state (EoS); (ii) the masquerade problem: modern EoS for cold, high density hadronic and quark matter are almost identical; and (iii) the reconfinement puzzle: what to do when after a deconfinement transition the hadronic EoS becomes favorable again? We show that taking into account the compositeness of baryons (by excluded volume and/or quark Pauli blocking) on the hadronic side and confining and stiffening effects on the quark matter side results in an early phase transition to quark matter with sufficient stiffening at high densities which removes all three present-day puzzles of CS interiors. Moreover, in this new class of EoS for hybrid CS falls the interesting case of a strong first order phase transition which results in the observable high mass twin star phenomenon, an astrophysical observation of a critical endpoint in the QCD phase diagram

Abell 48 - a rare WN-type central star of a planetary nebula

Science.gov (United States)

Todt, H.; Kniazev, A. Y.; Gvaramadze, V. V.; Hamann, W.-R.; Buckley, D.; Crause, L.; Crawford, S. M.; Gulbis, A. A. S.; Hettlage, C.; Hooper, E.; Husser, T.-O.; Kotze, P.; Loaring, N.; Nordsieck, K. H.; O'Donoghue, D.; Pickering, T.; Potter, S.; Romero-Colmenero, E.; Vaisanen, P.; Williams, T.; Wolf, M.

2013-04-01

A considerable fraction of the central stars of planetary nebulae (CSPNe) are hydrogen-deficient. Almost all of these H-deficient central stars (CSs) display spectra with strong carbon and helium lines. Most of them exhibit emission-line spectra resembling those of massive WC stars. Therefore these stars are classed as CSPNe of spectral type [WC]. Recently, quantitative spectral analysis of two emission-line CSs, PB 8 and IC 4663, revealed that these stars do not belong to the [WC] class. Instead PB 8 has been classified as [WN/WC] type and IC 4663 as [WN] type. In this work we report the spectroscopic identification of another rare [WN] star, the CS of Abell 48. We performed a spectral analysis of Abell 48 with the Potsdam Wolf-Rayet (PoWR) models for expanding atmospheres. We find that the expanding atmosphere of Abell 48 is mainly composed of helium (85 per cent by mass), hydrogen (10 per cent) and nitrogen (5 per cent). The residual hydrogen and the enhanced nitrogen abundance make this object different from the other [WN] star IC 4663. We discuss the possible origin of this atmospheric composition.

Improving CS regulations.

Energy Technology Data Exchange (ETDEWEB)

Nesse, R.J.; Scheer, R.M.; Marasco, A.L.; Furey, R.

1980-10-01

President Carter issued Executive Order 12044 (3/28/78) that required all Federal agencies to distinguish between significant and insignificant regulations, and to determine whether a regulation will result in major impacts. This study gathered information on the impact of the order and the guidelines on the Office of Conservation and Solar Energy (CS) regulatory practices, investigated problems encountered by the CS staff when implementing the order and guidelines, and recommended solutions to resolve these problems. Major tasks accomplished and discussed are: (1) legislation, Executive Orders, and DOE Memoranda concerning Federal administrative procedures relevant to the development and analysis of regulations within CS reviewed; (2) relevant DOE Orders and Memoranda analyzed and key DOE and CS staff interviewed in order to accurately describe the current CS regulatory process; (3) DOE staff from the Office of the General Counsel, the Office of Policy and Evaluation, the Office of the Environment, and the Office of the Secretary interviewed to explore issues and problems encountered with current CS regulatory practices; (4) the regulatory processes at five other Federal agencies reviewed in order to see how other agencies have approached the regulatory process, dealt with specific regulatory problems, and responded to the Executive Order; and (5) based on the results of the preceding four tasks, recommendations for potential solutions to the CS regulatory problems developed. (MCW)

Contribution of radioactive 137Cs discharge by suspended sediment, coarse organic matter, and dissolved fraction from a headwater catchment in Fukushima after the Fukushima Dai-ichi Nuclear Power Plant accident.

Science.gov (United States)

Iwagami, Sho; Onda, Yuichi; Tsujimura, Maki; Abe, Yutaka

2017-01-01

Radiocesium ( 137 Cs) migration from headwaters in forested areas provides important information, as the output from forest streams subsequently enters various land-use areas and downstream rivers. Thus, it is important to determine the composition of 137 Cs fluxes (dissolved fraction, suspended sediment, or coarse organic matter) that migrate through a headwater stream. In this study, the 137 Cs discharge by suspended sediment and coarse organic matter from a forest headwater catchment was monitored. The 137 Cs concentrations in suspended sediment and coarse organic matter, such as leaves and branches, and the amounts of suspended sediment and coarse organic matter were measured at stream sites in three headwater catchments in Yamakiya District, located ∼35 km northwest of Fukushima Dai-ichi Nuclear Power Plant (FDNPP) from August 2012 to September 2013, following the earthquake and tsunami disaster. Suspended sediment and coarse organic matter were sampled at intervals of approximately 1-2 months. The 137 Cs concentrations of suspended sediment and coarse organic matter were 2.4-49 kBq/kg and 0.85-14 kBq/kg, respectively. The 137 Cs concentrations of the suspended sediment were closely correlated with the average deposition density of the catchment. The annual proportions of contribution of 137 Cs discharge by suspended sediment, coarse organic matter, and dissolved fraction were 96-99%, 0.0092-0.069%, and 0.73-3.7%, respectively. The total annual 137 Cs discharge from the catchment was 0.02-0.3% of the deposition. Copyright © 2016 Elsevier Ltd. All rights reserved.

UV Spectroscopy of Star-Grazing Comets Within the 49 Ceti Debris Disk

Science.gov (United States)

Miles, Brittany E.; Roberge, Aki; Welsh, Barry

2016-01-01

We present the analysis of time-variable Doppler-shifted absorption features in far-UV spectra of the unusual 49 Ceti debris disk. This nearly edge-on disk is one of the brightest known and is one of the very few containing detectable amounts of circumstellar (CS) gas as well as dust. In our two visits of Hubble Space Telescope STIS spectra, variable absorption features are seen on the wings of lines arising from CII and CIV but not for any of the other CS absorption lines. Similar variable features have long been seen in spectra of the well-studied Beta Pictoris debris disk and attributed to the transits of star-grazing comets. We calculated the velocity ranges and apparent column densities of the 49 Cet variable gas, which appears to have been moving at velocities of tens to hundreds of kms(-1) relative to the central star. The velocities in the redshifted variable event seen in the second visit show that the maximum distances of the in falling gas at the time of transit were about 0.050.2 au from the central star. A preliminary attempt at a composition analysis of the redshifted event suggests that the C/O ratio in the in falling gas is super-solar, as it is in the bulk of the stable disk gas.

Radiation damage in undoped CsI and CsI(Tl)

International Nuclear Information System (INIS)

Woody, C.L.; Kierstead, J.A.; Levy, P.W.; Stoll, S.

1992-01-01

Radiation damage has been studied in undoped CsI and CsI(TI) crystals using 60 Co gamma radiation for doses up to ∼ 4.2 x 10 6 . Samples from various manufacturers were measured ranging in size from 2.54 cm long cylinders to a 30 cm long block. Measurements were made on the change in optical transmission and scintillation light output as a function of dose. Although some samples showed a small change in transmission, a significant change in light output was observed for all samples. Recovery from damage was also studied as a function of time and exposure to UV light. A short lived phosphorescence was observed in undoped CsI, similar to the phosphorescence seen in CsI(TI)

Regeneration of Used Frying Palm Oil with Coffee Silverskin (CS), CS Ash (CSA) and Nanoparticles of CS (NCS).

Science.gov (United States)

Ismail, Samir Abd-Elmonem A; El-Anany, Ayman Mohammed; Ali, Rehab Farouk M

2017-01-01

The present investigation aimed to evaluate the efficiency of coffee silverskin (CS), CS ash (CSA) and nanoparticles of CS (NCS) in regeneration the quality of used frying palm oil. The adsorbents were mixed individually with used frying palm oil at level 4% (w/v) for 60 min. The properties of CS, CSA and NCS adsorbents were studied using (SEM) scanning electron microscopy technique. Some of physico-chemical characteristics of used frying palm oil (UFPO) and UFPO treated with adsorbents were determined. The results showed that the CS ash particles composed of irregular spherical and semispherical grains with deep cavities. The size of particles of CS ash ranged in diameter from 1.1 to 1.7 µm. The morphology of NCS consisted of cluster-type spherical nanoparticles and flakes. The particle size of NCS varies from 0.9 to 1.7 µm. Purification treatments caused marked (poil compared to untreated oil. The treatment of UFPO with 4% of adsorbents caused significant reductions in the content of free fatty acids ranged from 51.2 to 65.0%. The lowest level of peroxide (2.1 meq/kg) was recorded for UFPO treated with 4% of NCS. The highest reductions (72.8; 70.0%) in p-anisidine value were observed in UFPO treated with 4% of CSA and NCS, respectively. Treatment of UFPO with 4% of CS, CSA and NCS significantly lowered the polar content from 13.9% to 6.3, 4.8 and 3.9%, respectively. The results also indicate that CSA and NCS have nearly the same adsorption efficiency in lowering polymer content of UFPO. Filtration treatment of UFPO with 4% of CS, CSA and NCS markedly lowered the viscosity and colour values of treated UFPO.

Properties of CsI and CsI-TMAE photocathodes

International Nuclear Information System (INIS)

Anderson, D.F.; Kwan, S.; Peskov, V.; Hoeneisen, B.

1992-06-01

The importance of heating the CsI or CsI-TMAE photocathodes during preparation, as well as the importance of the gas environment on the quantum efficiency is presented. The dependence of the aging characteristics of these photocathodes on the operating temperature, on the presence of gas, and on the charge amplification of the chamber is also discussed. For CsI photocathodes charges in excess of 2x10 14 e - /mm 2 can be collected with little degradation of performance. A timing resolution of 0.55 ns is also achieved for single photoelectrons suggesting a possible time-of-flight detector

Concentration of 134Cs and 137Cs in Malaysian palm products

International Nuclear Information System (INIS)

Yii Mei Wo; Nor Aza Hassan; Narizan Sanusi

2008-08-01

Until today, countries importing food products from Malaysia, in region such as Indian Continental, Middle East, Central Europe and Central America still require the products to be tested for the radioactive contamination particularly for 134 Cs and 137 Cs. Information extracted from 3371 analytical results observed on isotopic concentration for 134 Cs and 137 Cs in the exported Malaysia origins palm products between years 2002 until 2007 had been summarized and reported in this work. Data shown that the concentration level of the concerned radio nuclides are below the minimum detectable activity and also well below maximum permissible limits adopted by Malaysian Government and also the international bodies. (Author)

Separation of 134Cs and 137Cs from 125I solution for medical applications

International Nuclear Information System (INIS)

Ram, Ramu; Dash, Ashutosh; Banerjee, Dayamoy

2015-01-01

While neutron irradiation of natural Xe gas followed by wet chemical dissolution of activation products constitutes a successful paradigm for the small scale production 125 I, the concomitant production of 134 Cs and 137 Cs emerged as the primary impediment which necessitates purification of 125 I solution. This paper describes an ion-exchange chromatographic technique using Resorcinol Formaldehyde (RF) resin to purify 125 I solution from 134 Cs and 137 Cs impurities. A thorough investigation of the adsorption parameters of RF resin was carried out to arrive at the experimental conditions resulting optimum retention of 134 Cs and 137 Cs impurities. Based on the experimental findings, an optimized separation procedure was developed in which the neutron irradiated dissolved products at pH ∝ 13 was passed through a chromatography column containing RF resin where in 134 Cs and 137 Cs impurities gets adsorbed leaving behind 125 I to appear in the effluent. The overall recovery of 125 I was >90% with acceptable purity amenable for clinical applications.

[Energy pooling collisions for K(4P) + Cs(5D) in a K-Cs mixture].

Science.gov (United States)

Aihemaiti, Pulati; Dai, Kang; Lu, Xin-hong; Shen, Yi-fan

2005-04-01

The rate coefficients for energy-pooling collisions K(4P) + Cs(5D) --> Cs(6S) + K(4D, 6S) in the K-Cs vapor mixture were measured relative to a known energy-pooling rate coefficient of a homonuclear reaction [i. e., Cs(6P) + Cs(5D) --> Cs(6S) + Cs (7D(J))]. Populations of the Cs(6P, 5D) and K(4P) states were produced by photodissociation of K2 and Cs2 molecules through the use of a dye laser radiation. The resulting fluorescence included the direct components emitted in the decay of the excited states produced by photodissociation and the induced components arising from the collisionally populated states. By combining relative intensities of the components with the effective lifetimes of Cs(6P) and K(4P) states, the rate coefficients (in units of 10(-9) cm3 x s(-1)) for the heteronuclear energy-pooling were found to be 2.6 and 3.6, respectively. The contribution to the rate coefficients from other processes are discussed.

ALMA Reveals Sequential High-mass Star Formation in the G9.62+0.19 Complex

Energy Technology Data Exchange (ETDEWEB)

Liu, Tie; Kim, Kee-Tae [Korea Astronomy and Space Science Institute 776, Daedeokdae-ro, Yuseong-gu, Daejeon, Korea 34055 (Korea, Republic of); Lacy, John [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States); Li, Pak Shing [Astronomy Department, University of California, Berkeley, CA 94720 (United States); Wang, Ke [European Southern Observatory, Karl-Schwarzschild-Str.2, D-85748 Garching bei München (Germany); Qin, Sheng-Li [Department of Astronomy, Yunnan University, and Key Laboratory of Astroparticle Physics of Yunnan Province, Kunming, 650091 (China); Zhang, Qizhou [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Garay, Guido; Mardones, Diego [Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago (Chile); Wu, Yuefang [Department of Astronomy, Peking University, Beijing 100871 (China); Zhu, Qingfeng [Astronomy Department, University of Science and Technology, Chinese Academy of Sciences, Hefei 210008 (China); Tatematsu, Ken’ichi; Hirota, Tomoya [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Ren, Zhiyuan; Li, Di [National Astronomical Observatories, Chinese Academy of Science, A20 Datun Road, Chaoyang District, Beijing 100012 (China); Liu, Sheng-Yuan; Chen, Huei-Ru; Su, Yu-Nung, E-mail: liutiepku@gmail.com [Academia Sinica, Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 106, Taiwan (China)

2017-11-01

Stellar feedback from high-mass stars (e.g., H ii regions) can strongly influence the surrounding interstellar medium and regulate star formation. Our new ALMA observations reveal sequential high-mass star formation taking place within one subvirial filamentary clump (the G9.62 clump) in the G9.62+0.19 complex. The 12 dense cores (MM1–MM12) detected by ALMA are at very different evolutionary stages, from the starless core phase to the UC H ii region phase. Three dense cores (MM6, MM7/G, MM8/F) are associated with outflows. The mass–velocity diagrams of the outflows associated with MM7/G and MM8/F can be well-fit by broken power laws. The mass–velocity diagram of the SiO outflow associated with MM8/F breaks much earlier than other outflow tracers (e.g., CO, SO, CS, HCN), suggesting that SiO traces newly shocked gas, while the other molecular lines (e.g., CO, SO, CS, HCN) mainly trace the ambient gas continuously entrained by outflow jets. Five cores (MM1, MM3, MM5, MM9, MM10) are massive starless core candidates whose masses are estimated to be larger than 25 M {sub ☉}, assuming a dust temperature of ≤20 K. The shocks from the expanding H ii regions (“B” and “C”) to the west may have a great impact on the G9.62 clump by compressing it into a filament and inducing core collapse successively, leading to sequential star formation. Our findings suggest that stellar feedback from H ii regions may enhance the star formation efficiency and suppress low-mass star formation in adjacent pre-existing massive clumps.

Changing US Attributes After CS-US Pairings Changes CS-Attribute-Assessments: Evidence for CS-US Associations in Attribute Conditioning.

Science.gov (United States)

Förderer, Sabine; Unkelbach, Christian

2016-03-01

Attribute Conditioning (AC) refers to people's changed assessments of stimuli's (CSs) attributes due to repeated pairing with stimuli (USs) possessing these attributes; for example, when an athletic person (US) is paired with a neutral person (CS), the neutral person is judged to be more athletic after the pairing. We hypothesize that this AC effect is due to CSs' associations with USs rather than direct associations with attributes. Three experiments test this hypothesis by changing US attributes after CS-US pairings. Experiments 1 and 2 conditioned athleticism by pairing neutral men (CSs) with athletic and non-athletic USs. Post-conditioning, USs' athleticism was reversed, which systematically influenced participants' assessment of CS athleticism. Experiment 3 conditioned athleticism and changed USs' musicality after CS-US pairings. This post-conditioning change affected musicality assessments of CSs but did not influence athleticism-assessments. The results indicate that AC effects are based on an associative CS-US-attribute structure. © 2016 by the Society for Personality and Social Psychology, Inc.

Exercise for laboratory comparison of calibration coefficient in 137Cs beam, radiation protection - 2013/2014

International Nuclear Information System (INIS)

Cabral, T.S.; Potiens, M.P.A.; Soares, C.M.A.; Silveira, R.R.; Khoury, H.; Borges, J.C.

2015-01-01

This work deals with the preliminary results of the second exercise of comparing the radiation monitors calibration laboratories in Brazil. The exercise involved eight laboratories and the measured quantity is the air kerma in a beam of 137 Cs for radioprotection. The exercise was conducted by the LNMRI/IRD, in a star shaped arrangement from October 2013 to July 2015. The largest deviation was 2% of the calibration coefficient that is acceptable for applications in radioprotection. (author)

A novel vanadosilicate with hexadeca-coordinated Cs+ ions as a highly effective Cs+ remover

International Nuclear Information System (INIS)

Datta, Shuvo Jit; Moon, Won Kyung; Choi, Do Young; Hwang, In Chul; Yoon, Kyung Byung

2014-01-01

The effective removal of 137 Cs + ions from contaminated groundwater and seawater and from radioactive nuclear waste solutions is crucial for public health and for the continuous operation of nuclear power plants. Various 137 Cs + removers have been developed, but more effective 137 Cs + removers are still needed. A novel microporous vanadosilicate with mixed-valence vanadium (V 4+ and V 5+ ) ions is now reported, which shows an excellent ability for Cs + capture and immobilization from groundwater, seawater, and nuclear waste solutions. This material is superior to other known materials in terms of selectivity, capacity, and kinetics, and at very low Cs + concentrations, it was found to be the most effective material for the removal of radioactive Cs + ions under the test conditions. This novel vanadosilicate also contains hexadeca-coordinated Cs + ions, which corresponds to the highest coordination number ever described.

Parkinson’s Disease Impulsive-Compulsive Disorders Questionnaire – Current Short (QUIP-CS – Translation and validation of content of Portuguese Version

Directory of Open Access Journals (Sweden)

Débora Mascella Krieger

Full Text Available ABSTRACT Objective Parkinson’s disease (PD management is usually successfully reached with proper pharmacological treatment. However, PD patients can manifest neuropsychiatric symptoms secondary to medical therapy, including impulse control disorders (ICD, presenting as pathological gambling, hypersexuality, compulsive buying, drinking or eating disorders. We translated and validated the Portuguese version of the gold-standard questionnaire Parkinson’s Disease Impulsive-Compulsive Disorders Questionnaire, or (QUIP for identifying ICDs in PD patients. Methods Translation, back translation and submission to instrument developer was performed, that approved its new version comparing it to his original, validated version, with no loss of it’s original properties. Then, the Portuguese version was administered to 30 PD patients. They also were asked to rate from 1 to 5 the level of comprehensibility of the questions. Results The average level of comprehension was 4.06 ± 0.69 DP, considering 3 or more as acceptable. No patient has answered 1 or 2. Conclusion Our results on Portuguese version of QUIP-CS show that QUIP-CS translated and corrected version was easily understood and easily self-applied.

Hybridization of Single Nanocrystals of Cs4PbBr6 and CsPbBr3.

Science.gov (United States)

Weerd, Chris de; Lin, Junhao; Gomez, Leyre; Fujiwara, Yasufumi; Suenaga, Kazutomo; Gregorkiewicz, Tom

2017-09-07

Nanocrystals of all-inorganic cesium lead halide perovskites (CsPbX 3 , X = Cl, Br, I) feature high absorption and efficient narrow-band emission which renders them promising for future generation of photovoltaic and optoelectronic devices. Colloidal ensembles of these nanocrystals can be conveniently prepared by chemical synthesis. However, in the case of CsPbBr 3 , its synthesis can also yield nanocrystals of Cs 4 PbBr 6 and the properties of the two are easily confused. Here, we investigate in detail the optical characteristics of simultaneously synthesized green-emitting CsPbBr 3 and insulating Cs 4 PbBr 6 nanocrystals. We demonstrate that, in this case, the two materials inevitably hybridize, forming nanoparticles with a spherical shape. The actual amount of these Cs 4 PbBr 6 nanocrystals and nanohybrids increases for synthesis at lower temperatures, i.e., the condition typically used for the development of perovskite CsPbBr 3 nanocrystals with smaller sizes. We use state-of-the-art electron energy loss spectroscopy to characterize nanoparticles at the single object level. This method allows distinguishing between optical characteristics of a pure Cs 4 PbBr 6 and CsPbBr 3 nanocrystal and their nanohybrid. In this way, we resolve some of the recent misconceptions concerning possible visible absorption and emission of Cs 4 PbBr 6 . Our method provides detailed structural characterization, and combined with modeling, we conclusively identify the nanospheres as CsPbBr 3 /Cs 4 PbBr 6 hybrids. We show that the two phases are independent of each other's presence and merge symbiotically. Herein, the optical characteristics of the parent materials are preserved, allowing for an increased absorption in the UV due to Cs 4 PbBr 6 , accompanied by the distinctive efficient green emission resulting from CsPbBr 3 .

Properties of Cs-intercalated single wall carbon nanotubes investigated by 133Cs Nuclear Magnetic resonance

KAUST Repository

Schmid, Marc R.

2012-11-01

In the present study, we investigated Cs-intercalated single wall carbon nanotubes (SWCNTs) using 133Cs Nuclear Magnetic resonance. We show that there are two types of Cs cations depending on the insertion level. Indeed, at low concentrations, Static spectra analysis shows that the Cs (α)+ species are fully ionized, i.e. α equal ca.1, while at higher concentrations a second paramagnetically shifted line appears, indicating the formation of Cs (β)+ ions with β < α ∼ +1. At low concentrations and low temperatures the Cs (α)+ ions exhibit a weak hyperfine coupling to the SWCNT conduction electrons, whereas, at higher temperatures, a thermally activated slow-motion diffusion process of the Cs (α)+ ions occurs along the interstitial channels present within the carbon nanotube bundles. At high concentrations, the Cs (β)+ ions seem to occupy well defined positions relative to the carbon lattice. As a matter of fact, the Korringa relaxation behavior suggests a strong hyperfine coupling between Cs nuclei and conduction electrons in the carbon nanotubes and a partial charge transfer, which suggest a plausible Cs(6s)-C(2p) hybridization. © 2012 Elsevier Ltd. All rights reserved.

ChromaStarPy: A Stellar Atmosphere and Spectrum Modeling and Visualization Lab in Python

Science.gov (United States)

Short, C. Ian; Bayer, Jason H. T.; Burns, Lindsey M.

2018-02-01

We announce ChromaStarPy, an integrated general stellar atmospheric modeling and spectrum synthesis code written entirely in python V. 3. ChromaStarPy is a direct port of the ChromaStarServer (CSServ) Java modeling code described in earlier papers in this series, and many of the associated JavaScript (JS) post-processing procedures have been ported and incorporated into CSPy so that students have access to ready-made data products. A python integrated development environment (IDE) allows a student in a more advanced course to experiment with the code and to graphically visualize intermediate and final results, ad hoc, as they are running it. CSPy allows students and researchers to compare modeled to observed spectra in the same IDE in which they are processing observational data, while having complete control over the stellar parameters affecting the synthetic spectra. We also take the opportunity to describe improvements that have been made to the related codes, ChromaStar (CS), CSServ, and ChromaStarDB (CSDB), that, where relevant, have also been incorporated into CSPy. The application may be found at the home page of the OpenStars project: http://www.ap.smu.ca/OpenStars/.

Thermal gravimetric analysis of the CsCuCl3, Cs2CuCl4 and Cs2CuCl4x2H2O crystals

International Nuclear Information System (INIS)

Soboleva, L.V.; Vasil'eva, M.G.

1977-01-01

The thermal characteristics of crystals of Cs 2 CuCl 4 , Cs 2 CuCl 4 x2H 2 O, and CsCuCl 3 were investigated thermogravimetrically. The derivatogram of the Cs 2 CuCl 4 crystal is characterized by the presence of a single endothermal effect at 505 deg C. The derivatogram of the Cs 2 CuCl 4 x2H 2 O crystal contains three endothermal effects: at 40, 135, and 480 deg C. The derivatogram of the CsCuCl 3 crystal shows the presence of two endothermal effects at 142 and 455 deg C. The thermogravimetric data on Cs 2 CuCl 4 and CsCuCl 3 crystals reveal crystal decomposition on melting; hence, these crystals cannot be grown from melts

135Cs/137Cs isotopic composition of environmental samples across Europe: Environmental transport and source term emission applications

International Nuclear Information System (INIS)

Snow, Mathew S.; Snyder, Darin C.

2016-01-01

135 Cs/ 137 Cs isotopic analyses represent an important tool for studying the fate and transport of radiocesium in the environment; in this work the 135 Cs/ 137 Cs isotopic composition in environmental samples taken from across Europe is reported. Surface soil and vegetation samples from western Russia, Ukraine, Austria, and Hungary show consistent aged thermal fission product 135 Cs/ 137 Cs isotope ratios of 0.58 ± 0.01 (age corrected to 1/1/15), with the exception of one sample of soil-moss from Hungary which shows an elevated 135 Cs/ 137 Cs ratio of 1.78 ± 0.12. With the exception of the outlier sample from Hungary, surface soil/vegetation data are in quantitative agreement with values previously reported for soils within the Chernobyl exclusion zone, suggesting that radiocesium at these locations is primarily composed of homogenous airborne deposition from Chernobyl. Seawater samples taken from the Irish Sea show 135 Cs/ 137 Cs isotope ratios of 1.22 ± 0.11 (age corrected to 1/1/15), suggesting aged thermal fission product Cs discharged from Sellafield. The differences in 135 Cs/ 137 Cs isotope ratios between Sellafield, Chernobyl, and global nuclear weapons testing fallout indicate that 135 Cs/ 137 Cs isotope ratios can be utilized to discriminate between and track radiocesium transport from different nuclear production source terms, including major emission sources in Europe. - Highlights: • 135 Cs/ 137 Cs useful for tracking anthropogenic environmental radiocesium releases. • European surface soils/vegetation have uniform ratio consistent with Chernobyl. • 135 Cs/ 137 Cs in Irish sea represents thermal fission ratio distinct from Chernobyl. • Can distinguish between major source terms in Europe based on 135 Cs/ 137 Cs.

Reactive barriers for 137Cs retention

International Nuclear Information System (INIS)

Krumhansl, James L.; Brady, Patrick V.; Anderson, Howard L.

2000-01-01

137 Cs was dispersed globally by cold war activities and, more recently, by the Chernobyl accident. Engineered extraction of 137 Cs from soils and groundwaters is exceedingly difficult. Because the half life of 137 Cs is only 30.2 years, remediation might be more effective (and less costly) if 137 Cs bioavailability could be demonstrably limited for even a few decades by use of a reactive barrier. Essentially permanent isolation must be demonstrated in those few settings where high nuclear level wastes contaminated the environment with 135 Cs (half life 2.3x10 6 years) in addition to 137 Cs. Clays are potentially a low-cost barrier to Cs movement, though their long-term effectiveness remains untested. To identify optimal clays for Cs retention Cs resorption was measured for five common clays: Wyoming Montmorillonite (SWy-1), Georgia Kaolinites (KGa-1 and KGa-2), Fithian Illite (F-Ill), and K-Metabentonite (K-Mbt). Exchange sites were pre-saturated with 0.16 M CsCl for 14 days and readily exchangeable Cs was removed by a series of LiNO 3 and LiCl washes. Washed clay were then placed into dialysis bags and the Cs release to the deionized water outside the bags measured. Release rates from 75 to 139 days for SWy-1, K-Mbt and F- 111 were similar; 0.017 to 0.021% sorbed Cs released per day. Both kaolinites released Cs more rapidly (0.12 to 0.05% of the sorbed Cs per day). In a second set of experiments, clays were doped for 110 days and subjected to an extreme and prolonged rinsing process. All the clays exhibited some capacity for irreversible Cs uptake so most soils have some limited ability to act as a natural barrier to Cs migration. However, the residual loading was greatest on K-Mbt (∼ 0.33 wt% Cs). Thus, this clay would be the optimal material for constructing artificial reactive barriers

137Cs in man organism

International Nuclear Information System (INIS)

Marej, A.N.; Barkhudarov, R.M.

1980-01-01

Considered are the levels of 137 Cs content in the organism of adult urban population of the USSR and the main regularities of their alterations during 1962-1974. The non-uniform distribution of levels of 137 Cs buildup in adult population is shown to be connected with soil and geographic conditions. Food stuffs of local production have a noticeable effect on the levels of 137 Cs buildup in the organism of urban population. Calculation methods are used to study 137 Cs administration in a human organism. No significant difference is found between the indexes of 137 Cs content in the organism of rural and urban population. Presented are the levels of 137 Cs content in the organisms of inhabitants of such regions as Far North and Byelorussian-Ukrainian woodlands. Given are the reasons for the increased content of 137 Cs in the organism of rural population of these zones

Exploring Polaronic, Excitonic Structures and Luminescence in Cs4PbBr6/CsPbBr3.

Science.gov (United States)

Kang, Byungkyun; Biswas, Koushik

2018-02-15

Among the important family of halide perovskites, one particular case of all-inorganic, 0-D Cs 4 PbBr 6 and 3-D CsPbBr 3 -based nanostructures and thin films is witnessing intense activity due to ultrafast luminescence with high quantum yield. To understand their emissive behavior, we use hybrid density functional calculations to first compare the ground-state electronic structure of the two prospective compounds. The dispersive band edges of CsPbBr 3 do not support self-trapped carriers, which agrees with reports of weak exciton binding energy and high photocurrent. The larger gap 0-D material Cs 4 PbBr 6 , however, reveals polaronic and excitonic features. We show that those lattice-coupled carriers are likely responsible for observed ultraviolet emission around ∼375 nm, reported in bulk Cs 4 PbBr 6 and Cs 4 PbBr 6 /CsPbBr 3 composites. Ionization potential calculations and estimates of type-I band alignment support the notion of quantum confinement leading to fast, green emission from CsPbBr 3 nanostructures embedded in Cs 4 PbBr 6 .

Temperature and Pressure Dependence of the Reaction S plus CS (+M) -> CS2 (+M)

DEFF Research Database (Denmark)

Glarborg, Peter; Marshall, Paul; Troe, Juergen

2015-01-01

Experimental data for the unimolecular decomposition of CS2 from the literature are analyzed by unimolecular rate theory with the goal of obtaining rate constants for the reverse reaction S + CS (+M) -> CS2 (+M) over wide temperature and pressure ranges. The results constitute an important input...

A simple method for the deconvolution of 134 Cs/137 Cs peaks in gamma-ray scintillation spectrometry

International Nuclear Information System (INIS)

Darko, E.O.; Osae, E.K.; Schandorf, C.

1998-01-01

A simple method for the deconvolution of 134 Cs / 137 Cs peaks in a given mixture of 134 Cs and 137 Cs using Nal(TI) gamma-ray scintillation spectrometry is described. In this method the 795 keV energy of 134 Cs is used as a reference peak to calculate the activity of the 137 Cs directly from the measured peaks. Certified reference materials were measured using the method and compared with a high resolution gamma-ray spectrometry measurements. The results showed good agreement with the certified values. The method is very simple and does not need any complicated mathematics and computer programme to de- convolute the overlapping 604.7 keV and 661.6 keV peaks of 134 Cs and 137 Cs respectively. (author). 14 refs.; 1 tab., 2 figs

Microhydration of caesium compounds: Cs, CsOH, CsI and Cs₂I₂ complexes with one to three H₂O molecules of nuclear safety interest.

Science.gov (United States)

Sudolská, Mária; Cantrel, Laurent; Cernušák, Ivan

2014-04-01

Structure and thermodynamic properties (standard enthalpies of formation and Gibbs free energies) of hydrated caesium species of nuclear safety interest, Cs, CsOH, CsI and its dimer Cs₂I₂, with one up to three water molecules, are calculated to assess their possible existence in severe accident occurring to a pressurized water reactor. The calculations were performed using the coupled cluster theory including single, double and non-iterative triple substitutions (CCSD(T)) in conjunction with the basis sets (ANO-RCC) developed for scalar relativistic calculations. The second-order spin-free Douglas-Kroll-Hess Hamiltonian was used to account for the scalar relativistic effects. Thermodynamic properties obtained by these correlated ab initio calculations (entropies and thermal capacities at constant pressure as a function of temperature) are used in nuclear accident simulations using ASTEC/SOPHAEROS software. Interaction energies, standard enthalpies and Gibbs free energies of successive water molecules addition determine the ordering of the complexes. CsOH forms the most hydrated stable complexes followed by CsI, Cs₂I₂, and Cs. CsOH still exists in steam atmosphere even at quite high temperature, up to around 1100 K.

1+ collective states of 124Cs and 126Cs nuclei

International Nuclear Information System (INIS)

Ivanova, S.P.; Kuliev, A.A.; Salamov, D.I.

1977-01-01

Within the framework of the random phase approximation β-decay properties of the 1 + states of 124 Cs and 126 Cs have been investigated. Greatly collectivized 1 + states in odd-odd nuclei are produced by the spin-dependent charge-exchange nucleon interaction. For numerical calculations the scheme of single-particle levels in the deformed Saxon-Woods potential has been used

Cesium platinide hydride 4Cs{sub 2}Pt.CsH: an intermetallic double salt featuring metal anions

Energy Technology Data Exchange (ETDEWEB)

Smetana, Volodymyr [Ames Laboratory, US Department of Energy, and Critical Materials Institute, Ames, Iowa, 50011-3020 (United States); Mudring, Anja-Verena [Ames Laboratory, US Department of Energy, and Critical Materials Institute, Ames, Iowa, 50011-3020 (United States); Department of Materials Sciences and Engineering, Iowa State University, Ames, Iowa, 50011-3111 (United States)

2016-11-14

With Cs{sub 9}Pt{sub 4}H a new representative of ionic compounds featuring metal anions can be added to this rare-membered family. Cs{sub 9}Pt{sub 4}H exhibits a complex crystal structure containing Cs{sup +} cations, Pt{sup 2-} and H{sup -} anions. Being a red, transparent compound its band gap is in the visible range of the electromagnetic spectrum and the ionic type of bonding is confirmed by quantum chemical calculations. This cesium platinide hydride can formally be considered as a double salt of the ''alloy'' cesium-platinum, or better cesium platinide, Cs{sub 2}Pt, and the salt cesium hydride CsH according to Cs{sub 9}Pt{sub 4}H≡4 Cs{sub 2}Pt.CsH. (copyright 2016 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Knudsen cell--mass spectrometer studies of cesium--urania interactions. [Cs/sub 2/CO/sub 3/ or CsOH

Energy Technology Data Exchange (ETDEWEB)

Collins, J.L.; Osborne, M.F.; Malinauskas, A.P.; Lorenz, R.A.; Manning, S.R.

1976-06-01

Limited Knudsen cell--mass spectrometer studies were made of the partial pressures of cesium-containing species (assumed to be primarily Cs(g)) over Cs/sub 2/CO/sub 3/ and over phase equilibria involving UO/sub 2/ and probable Cs-U-O compounds formed from mixtures that initially contained either Cs/sub 2/CO/sub 3/-UO/sub 2/ or CsOH-UO/sub 2/. Although additional work is required to further define the equilibria involved, the data demonstrate unambiguously a significant reduction in cesium partial pressures due to probable Cs-U-O compound formation and indicate essentially identical behavior with either CsOH or Cs/sub 2/CO/sub 3/ as the starting material with UO/sub 2/.

Development of certified matrix reference materials for quality assurance of screening 134Cs and 137Cs in food

International Nuclear Information System (INIS)

Ishizu, H.; Yamada, T.

2013-01-01

A certified reference material using activated alumina powder certified for activity of 134 Cs and 137 Cs was developed. The results of the verification and the certification are described. The certified reference material can be used for quality assurance of screening activity measurements of 134 Cs and 137 Cs in food/foodstuffs. Commercially available equipments were experimentally tested using the CRM and another CRM including 40 K. The results of these tests are also shown. - Highlights: • CRM of 134 Cs and 137 Cs using activated alumina was developed. • CRM including 134 Cs, 137 Cs and 40 K was also developed. • Results of experimental performance test of commercial inspection equipments using CRMs were shown

Ab Initio investigation of cesium monoxide of CsO and CsO+

International Nuclear Information System (INIS)

Zialenina, M.; Kelloe, V.; Cernusak, I.

2015-01-01

Cesium is material with a low work function and, accordingly, atomic Cs has a low value of ionization energy. Therefore cesium is regarded as a good source material for electrons in plasma heating module. One of plasma heating technologies using Cs grid is foreseen as a candidate for the tokamak within the framework of project ITER. Among the possible impurities that can coexist in this module are CsO or CsO + , due to presence of oxygen traces in the heating chamber. We conducted CCSD(T) energy calculations of the cesium oxide (X 2 Σ + ) and its cation (X 3 Σ - ). Here are presented the bond lengths and spectroscopic parameters of both species and ionization energy (IE). Our IE (6.88 eV) is in good agreement with previous theoretical results, experiment indicates substantially lower value (6.22 eV). (authors)

Luminescence properties of undoped CsCaCl3 and CsSrCl3 crystalline scintillators

International Nuclear Information System (INIS)

Fujimoto, Yutaka; Saeki, Keiichiro; Koshimizu, Masanori; Asai, Keisuke; Yanagida, Takayuki

2015-01-01

Intrinsic luminescence properties of undoped CsCaCl 3 and CsSrCl 3 crystalline scintillators were studied. The crystal samples were grown by a vertical Bridgman method. Photoluminescence spectra of the crystals showed Auger-free luminescence (AFL) at 310 nm and self-trapped emission (STE) at 400 nm for CsCaCl 3 and 465 nm for CsSrCl 3 , when vacuum ultraviolet (VUV) light at 84 nm and 160 nm excited the crystals. X-ray excited radioluminescence spectra of the crystals showed some emission bands in the 280-600 nm wavelength range, which are owing to AFL, STE, and other origins such as lattice defects and impurities. Scintillation light yield was 400-300 ph/MeV, and the principal scintillation decay time about 2.5 ns and 12 ns for CsCaCl 3 and 1.8 ns and 13 ns for CsSrCl 3 . (author)

Fast CsI-phoswich detector

International Nuclear Information System (INIS)

Langenbrunner, J.R.

1996-01-01

An improved phoswich radiation detector used pure CsI crystal and a fast plastic scintillator and a single photomultiplier tube. The plastic is arranged to receive incident radiation, and that which passed through then strikes the CsI crystal. Scintillation light from both the plastic and CsI crystal are applied to the photomultiplier tube, with the light from the plastic passing through the crystal without absorption therein. Electronics are provided for analyzing the output of the photomultiplier tube to discriminate responses due to the plastic and the CsI crystal, through short gate and long gate integration, to produce results which are indicative of the characteristics of the different types of incident radiation, even in the presence of large amounts of radiation. The phoswich detector has excellent timing resolution. The scintillators of the CsI- phoswich were chosen for their fast risetimes, of about 3 ns for NE102A, and 30 ns for the pure CsI. 5 figs

Rapid determination of {sup 135}Cs and precise {sup 135}Cs/{sup 137}Cs atomic ratio in environmental samples by single-column chromatography coupled to triple-quadrupole inductively coupled plasma-mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Yang, Guosheng [Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564 (Japan); Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Beijing Engineering Research Center of Radiographic Techniques and Equipment, Beijing 100049 (China); Tazoe, Hirofumi [Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564 (Japan); Yamada, Masatoshi, E-mail: myamada@hirosaki-u.ac.jp [Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564 (Japan)

2016-02-18

For source identification, measurement of {sup 135}Cs/{sup 137}Cs atomic ratio not only provides information apart from the detection of {sup 134}Cs and {sup 137}Cs, but it can also overcome the application limit that measurement of the {sup 134}Cs/{sup 137}Cs ratio has due to the short half-life of {sup 134}Cs (2.06 y). With the recent advancement of ICP-MS, it is necessary to improve the corresponding separation method for rapid and precise {sup 135}Cs/{sup 137}Cs atomic ratio analysis. A novel separation and purification technique was developed for the new generation of triple-quadrupole inductively coupled plasma-mass spectrometry (ICP-MS/MS). The simple chemical separation, incorporating ammonium molybdophosphate selective adsorption of Cs and subsequent single cation-exchange chromatography, removes the majority of isobaric and polyatomic interference elements. Subsequently, the ICP-MS/MS removes residual interference elements and eliminates the peak tailing effect of stable {sup 133}Cs, at m/z 134, 135, and 137. The developed analytical method was successfully applied to measure {sup 135}Cs/{sup 137}Cs atomic ratios and {sup 135}Cs activities in environmental samples (soil and sediment) for radiocesium source identification. - Highlights: • A simple {sup 135}Cs/{sup 137}Cs analytical method was developed. • The separation procedure was based on AMP adsorption and one column chromatography. • {sup 135}Cs/{sup 137}Cs was measured by ICP-MS/MS. • Decontamination factors for Ba, Mo, Sb, and Sn were improved. • {sup 135}Cs/{sup 137}Cs atomic ratios of 0.341–0.351 were found in Japanese soil samples.

A novel vanadosilicate with hexadeca-coordinated Cs{sup +} ions as a highly effective Cs{sup +} remover

Energy Technology Data Exchange (ETDEWEB)

Datta, Shuvo Jit; Moon, Won Kyung; Choi, Do Young; Hwang, In Chul; Yoon, Kyung Byung [Sogang Univ., Seoul (Korea, Republic of). Korea Center for Artificial Photosynthesis

2014-07-07

The effective removal of {sup 137}Cs{sup +} ions from contaminated groundwater and seawater and from radioactive nuclear waste solutions is crucial for public health and for the continuous operation of nuclear power plants. Various {sup 137}Cs{sup +} removers have been developed, but more effective {sup 137}Cs{sup +} removers are still needed. A novel microporous vanadosilicate with mixed-valence vanadium (V{sup 4+} and V{sup 5+}) ions is now reported, which shows an excellent ability for Cs{sup +} capture and immobilization from groundwater, seawater, and nuclear waste solutions. This material is superior to other known materials in terms of selectivity, capacity, and kinetics, and at very low Cs{sup +} concentrations, it was found to be the most effective material for the removal of radioactive Cs{sup +} ions under the test conditions. This novel vanadosilicate also contains hexadeca-coordinated Cs{sup +} ions, which corresponds to the highest coordination number ever described.

The behavior of radioactive 137Cs and stable Cs at the isolated undisturbed mountain pond in Fukui, Japan

International Nuclear Information System (INIS)

Iwamoto, Kazumi; Kimura, Makio; Ando, Kenji; Amano, Hikaru

2003-01-01

The behavior of radioactive 137 Cs and stable Cs at the isolated undisturbed mountain pond in Fukui, Japan was studied for the pond water, the sedimentary grains and the soil near the pond. The concentrations of 137 Cs and stable Cs in the pond water ranged from 0.23 to 0.85 Bq/m 3 and from 0.005 to 0.018 mg/m 3 , respectively. The sedimentary grains were sorted by sieving into fractions with diameter from 2 mm to less than 38 μm. The concentrations of 137 Cs and stable Cs in the sorted grains were measured, and those of the adsorbed state were determined by subtracting the concentration of the grain matrix. The adsorbed concentrations increased with decrease in particle diameter and depended less on the kind of samples. The in-situ distribution coefficient Kd depended largely on particle diameter and increased with the decrease in diameter. The values of Kd ranged from about 20 to 1200 m 3 /kg for stable Cs and about 15 to 1000 m 3 /kg for 137 Cs, and the Kd of 137 Cs seemed to be slightly smaller than that of stable Cs. The concentration of stable Cs in the sedimentary mud was found to be close to that of the fine grains. The concentrations of stable Cs in the soil near the pond was about 7.7 mg/kg, and that of 137 Cs was about 0.6 kBq/kg for the surface layer soil and decreased with increase in soil depth. (author)

The Godparent Plan: A Pedagogical Strategy for CS1 Accompaniment and CS2 Pedagogical Enhancement

Directory of Open Access Journals (Sweden)

Pedro Guillermo Feijóo-García

2018-02-01

Full Text Available Courses such as CS1 and CS2 can present an interesting pedagogical challenge when it comes to the theory-practice relationship, along with aspects that involve the course's logistics, the programming language used, and the characteristics of the students involved in the process. This study presents an innovative didactic approach, oriented towards the accompaniment of CS1 students by CS2 students at Universidad El Bosque, Colombia, seeking with this Godparent Plan, to provide a personalized accompaniment to first semester students, whereby CS2 students enhance their domain over concepts and skills while accompanying, explaining and teaching younger peers. The results of this study are favorable, outlining a didactic scheme that can be adapted and replicated in other curricular scenarios.

Correlations between potassium, rubidium and cesium (133Cs and 137Cs) in sporocarps of Suillus variegatus in a Swedish boreal forest

International Nuclear Information System (INIS)

Vinichuk, M.; Rosen, K.; Johanson, K.J.; Dahlberg, A.

2011-01-01

An analysis of sporocarps of ectomycorrhizal fungi Suillus variegatus assessed whether cesium ( 133 Cs and 137 Cs) uptake was correlated with potassium (K) or rubidium (Rb) uptake. The question was whether intraspecific correlations of Rb, K and 133 Cs mass concentrations with 137 Cs activity concentrations in sporocarps were higher within, rather than among, different fungal species, and if genotypic origin of sporocarps within a population affected uptake and correlation. Sporocarps (n = 51) from a Swedish forest population affected by the fallout after the Chernobyl accident were studied. The concentrations were 31.9 ± 6.79 g kg -1 for K (mean ± SD, dwt), 0.40 ± 0.09 g kg -1 for Rb, 8.7 ± 4.36 mg kg -1 for 133 Cs and 63.7 ± 24.2 kBq kg -1 for 137 Cs. The mass concentrations of 133 Cs correlated with 137 Cs activity concentrations (r = 0.61). There was correlation between both 133 Cs concentrations (r = 0.75) and 137 Cs activity concentrations (r = 0.44) and Rb, but the 137 Cs/ 133 Cs isotopic ratio negatively correlated with Rb concentration. Concentrations of K and Rb were weakly correlated (r = 0.51). The 133 Cs mass concentrations, 137 Cs activity concentrations and 137 Cs/ 133 Cs isotopic ratios did not correlate with K concentrations. No differences between, within or, among genotypes in S. variegatus were found. This suggested the relationships between K, Rb, 133 Cs and 137 Cs in sporocarps of S. variegatus is similar to other fungal species. - Highlights: → We studied uptake of Cs ( 133 Cs and 137 Cs), K and Rb by Suillus variegates sporocarps. → Genotypic origin of fungus did not affect uptake of studied elements (isotopes). → Genotypic origin did not affect correlation between Cs ( 133 Cs and 137 Cs), K and Rb.

Measurement of thermal neutron cross section and resonance integral of the reaction {sup 135}Cs(n,{gamma}){sup 136}Cs

Energy Technology Data Exchange (ETDEWEB)

Katoh, Toshio; Nakamura, Shoji; Harada, Hideo [Power Reactor and Nuclear Fuel Development Corp., Tokyo (Japan); Hatsukawa, Yuichi; Shinohara, Nobuo; Hata, Kentaro; Kobayashi, Katsutoshi; Motoishi, Shoji; Tanase, Masakazu

1997-03-01

The thermal neutron(2,200 m/s neutron) capture cross section({sigma}{sub 0}) and the resonance integral(I{sub 0}) of the reaction {sup 135}Cs(n,{gamma}){sup 136}Cs were measured by an activation method. Targets of radioactive cesium, which include {sup 135}Cs, {sup 137}Cs and stable {sup 133}Cs, were irradiated with reactor neutrons within or without a Cd shield case. The ratio of the number of nuclei of {sup 135}Cs to that of {sup 137}Cs was measured with a quadrupole mass spectrometer. This ratio and the ratio of activity of {sup 136}Cs to that of {sup 137}Cs were used for deduction of the {sigma}{sub 0} and the I{sub 0} of {sup 135}Cs. The {sigma}{sub 0} and the I{sub 0} of the reaction {sup 135}Cs(n,{sigma}){sup 136}Cs were 8.3 {+-} 0.3 barn and 38.1 {+-} 2.6 barn, respectively. (author)

Cs/CsPbX3 (X = Br, Cl) epitaxial heteronanocrystals with magic-angle stable/metastable grain boundary

Science.gov (United States)

Zhang, Yumeng; Fan, Baolu; Wu, Wenhui; Fan, Jiyang

2017-05-01

Metal-semiconductor heteronanostructures are crucial building blocks of nanoscale electronic and optoelectronic devices. However, the lattice misfit remains a challenge in constructing heteronanostructures. Perovskite nanocrystals are superior candidates for constructing nanodevices owing to excellent optical, ferroelectric, and superconducting properties. We report the epitaxial growth of lattice-matched Cs/CsPbBr3 metal-semiconductor heteronanocrystals in a liquid medium. The well-crystallized ultrathin Cs layers grow epitaxially on the surfaces of colloidal CsPbBr3 nanocrystals, forming heteronanocrystals with interface diameters of several nanometers. Most of them are pseudomorphic with coherent interfaces free from dislocations, and the others exhibit discrete high-angle grain boundaries. The model based on the calculation of the elastic potential energy of the epilayer and analysis of the near-coincidence sites explains well the experimental result. The analysis shows that the excellent lattice match between the metal and the semiconductor ensures the ideal epitaxial-growth of both Cs/CsPbBr3 and Cs/CsPbCl3 heteronanocrystals. Such metal/semiconductor heteronanocrystals pave the way for developing perovskite-based nanodevices.

Phase Transitions in CsSnCl3 and CsPbBr3 An NMR and NQR Study

Science.gov (United States)

Sharma, Surendra; Weiden, Norbert; Weiss, Alarich

1991-04-01

The phase transitions in CsSnCl3 and CsPbBr3 have been studied by X-ray powder diffraction, by 81Br-NQR and by 'H-, 119Sn-, and 113Cs-NMR. At room temperature in air CsSnCl3 forms a hydrate which can be dehydrated to the monoclinic phase II of CsSnCl3. The high temperature phase I has the Perovskite structure, as the X-ray and NMR experiments show. The three phases of CsPbBr3, known from literature, have been corroborated. The results are discussed in the framework of the group ABX3, A = alkalimetal ion, B = IV main group ion, and X = Halogen ion

VERA-CS Verification & Validation Plan

Energy Technology Data Exchange (ETDEWEB)

Downar, Thomas [Univ. of Michigan, Ann Arbor, MI (United States)

2017-02-01

This report summarizes the current status of VERA-CS Verification and Validation for PWR Core Follow operation and proposes a multi-phase plan for continuing VERA-CS V&V in FY17 and FY18. The proposed plan recognizes the hierarchical nature of a multi-physics code system such as VERA-CS and the importance of first achieving an acceptable level of V&V on each of the single physics codes before focusing on the V&V of the coupled physics solution. The report summarizes the V&V of each of the single physics codes systems currently used for core follow analysis (ie MPACT, CTF, Multigroup Cross Section Generation, and BISON / Fuel Temperature Tables) and proposes specific actions to achieve a uniformly acceptable level of V&V in FY17. The report also recognizes the ongoing development of other codes important for PWR Core Follow (e.g. TIAMAT, MAMBA3D) and proposes Phase II (FY18) VERA-CS V&V activities in which those codes will also reach an acceptable level of V&V. The report then summarizes the current status of VERA-CS multi-physics V&V for PWR Core Follow and the ongoing PWR Core Follow V&V activities for FY17. An automated procedure and output data format is proposed for standardizing the output for core follow calculations and automatically generating tables and figures for the VERA-CS Latex file. A set of acceptance metrics is also proposed for the evaluation and assessment of core follow results that would be used within the script to automatically flag any results which require further analysis or more detailed explanation prior to being added to the VERA-CS validation base. After the Automation Scripts have been completed and tested using BEAVRS, the VERA-CS plan proposes the Watts Bar cycle depletion cases should be performed with the new cross section library and be included in the first draft of the new VERA-CS manual for release at the end of PoR15. Also, within the constraints imposed by the proprietary nature of plant data, as many as possible of the FY17

Epiphytic fruticose lichens as biomonitors for retrospective evaluation of the 134Cs/137Cs ratio in Fukushima fallout

International Nuclear Information System (INIS)

Ramzaev, V.; Barkovsky, A.; Gromov, A.; Ivanov, S.; Kaduka, M.

2014-01-01

In 2011–2013, sampling of epiphytic fruticose lichens of the genera Usnea, Bryoria and Alectoria was carried out on Sakhalin and Kuril Islands (the Sakhalin region, Russia) to investigate contamination of these organisms with the Fukushima-derived 134 Cs and 137 Cs. Activities of the radionuclides were determined in all 56 samples of lichens taken for the analysis. After correction for radioactive decay (on 15 March 2011), the activity concentrations ranged from 2.1 Bq kg −1 (d.w.) to 52 Bq kg −1 for 134 Cs and from 2.3 Bq kg −1 to 52 Bq kg −1 for 137 Cs. Cesium-134 and 137 Cs activities for the whole set of lichens (n = 56) were strongly positively correlated; Spearman's rank correlation coefficient was calculated as 0.991 (P < 0.01). The activity concentrations of 134 Cs and 137 Cs in Usnea lichens from the Sakhalin and Kunashir islands declined with a factor of three in the period from 2011 to 2013. The average biological half-time for both cesium radionuclides in lichens of the genus Usnea is estimated as 1.3 y. The mean of 0.99 ± 0.10 and median of 0.99 were calculated for the decay corrected 134 Cs/ 137 Cs activities ratios in the lichens (n = 56). The radionuclides ratio in the lichens did not depend on location of sampling site, species and the time that had passed after the Fukushima accident. The regression analysis has shown the background pre-Fukushima level of 137 Cs of 0.4 ± 0.3 Bq kg −1 , whereas the ratio between the Fukushima-borne 134 Cs and 137 Cs in the lichens was estimated as 1.04. The 134 Cs/ 137 Cs activities ratio in lichens from the Sakhalin region is consistent with the ratios reported by others for the heavy contaminated areas on Honshu Island in Japan following the Fukushima accident. The activity concentrations of natural 7 Be in lichens from the Sakhalin region varied between 100 Bq kg −1 and 600 Bq kg −1 ; the activity concentrations did not exhibit temporal variations during a 2y-period of observations. The

All-Ambient Processed Binary CsPbBr3-CsPb2Br5 Perovskites with Synergistic Enhancement for High-Efficiency Cs-Pb-Br-Based Solar Cells.

Science.gov (United States)

Zhang, Xisheng; Jin, Zhiwen; Zhang, Jingru; Bai, Dongliang; Bian, Hui; Wang, Kang; Sun, Jie; Wang, Qian; Liu, Shengzhong Frank

2018-02-28

All-inorganic CsPbBr 3 perovskite solar cells display outstanding stability toward moisture, light soaking, and thermal stressing, demonstrating great potential in tandem solar cells and toward commercialization. Unfortunately, it is still challenging to prepare high-performance CsPbBr 3 films at moderate temperatures. Herein, a uniform, compact CsPbBr 3 film was fabricated using its quantum dot (QD)-based ink precursor. The film was then treated using thiocyanate ethyl acetate (EA) solution in all-ambient conditions to produce a superior CsPbBr 3 -CsPb 2 Br 5 composite film with a larger grain size and minimal defects. The achievement was attributed to the surface dissolution and recrystallization of the existing SCN - and EA. More specifically, the SCN - ions were first absorbed on the Pb atoms, leading to the dissolution and stripping of Cs + and Br - ions from the CsPbBr 3 QDs. On the other hand, the EA solution enhances the diffusion dynamics of surface atoms and the surfactant species. It is found that a small amount of CsPb 2 Br 5 in the composite film gives the best surface passivation, while the Br-rich surface decreases Br vacancies (V Br ) for a prolonged carrier lifetime. As a result, the fabricated device gives a higher solar cell efficiency of 6.81% with an outstanding long-term stability.

The distribution of 137Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden

International Nuclear Information System (INIS)

Vinichuk, M.; Johanson, K.J.; Rydin, H.; Rosen, K.

2010-01-01

We record the distribution of 137 Cs, K, Rb and Cs within individual Sphagnum plants (down to 20 cm depth) as well as 137 Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris 137 Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher 137 Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of 137 Cs within the plants. The patterns of 137 Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The 137 Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10 cm) of the plant (r = 0.50). The strongest correlations were revealed between 137 Cs and Rb (r = 0.89), and between 137 Cs and stable Cs (r = 0.84). This suggests similarities between 137 Cs and Rb in uptake and relocation within the Sphagnum, but that 137 Cs differs from K.

The distribution of (137)Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden.

Science.gov (United States)

Vinichuk, M; Johanson, K J; Rydin, H; Rosén, K

2010-02-01

We record the distribution of (137)Cs, K, Rb and Cs within individual Sphagnum plants (down to 20cm depth) as well as (137)Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris(137)Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher (137)Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of (137)Cs within the plants. The patterns of (137)Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The (137)Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10cm) of the plant (r=0.50). The strongest correlations were revealed between (137)Cs and Rb (r=0.89), and between (137)Cs and stable Cs (r=0.84). This suggests similarities between (137)Cs and Rb in uptake and relocation within the Sphagnum, but that (137)Cs differs from K. Copyright 2009 Elsevier Ltd. All rights reserved.

Uptake and accumulation of 137Cs by upland grassland soil fungi: a potential pool of Cs immobilization

International Nuclear Information System (INIS)

Dighton, J.; Clint, G.M.; Poskitt, J.

1991-01-01

Reports of high concentrations of fallout radiocaesium in basidiomycete fruit bodies after the Chernobyl nuclear reactor accident and speculation that fungi could be long-term 137 Cs accumulators led us to ask if fungi could be long-term 137 Cs accumulators. We used six common upland grassland species to try to estimate their importance in the immobilization of 137 Cs. Uptake of Cs by these species ranged from 44 to 235 nmol Cs g − 1d.w. h − 1. Efflux studies indicate that more than 40% of the Cs taken up is bound within the hyphae. We estimate that the fungal component of the soil could immobilize the total radiocaesium fallout received in upland grasslands following the Chernobyl accident

Photoresponse of CsPbBr3 and Cs4PbBr6 Perovskite Single Crystals.

Science.gov (United States)

Cha, Ji-Hyun; Han, Jae Hoon; Yin, Wenping; Park, Cheolwoo; Park, Yongmin; Ahn, Tae Kyu; Cho, Jeong Ho; Jung, Duk-Young

2017-02-02

High-quality and millimeter-sized perovskite single crystals of CsPbBr 3 and Cs 4 PbBr 6 were prepared in organic solvents and studied for correlation between photocurrent generation and photoluminescence (PL) emission. The CsPbBr 3 crystals, which have a 3D perovskite structure, showed a highly sensitive photoresponse and poor PL signal. In contrast, Cs 4 PbBr 6 crystals, which have a 0D perovskite structure, exhibited more than 1 order of magnitude higher PL intensity than CsPbBr 3 , which generated an ultralow photoresponse under illumination. Their contrasting optoelectrical characteristics were attributed to different exciton binding energies, induced by coordination geometry of the [PbBr 6 ] 4- octahedron sublattices. This work correlated the local structures of lead in the primitive perovskite and its derivatives to PL spectra as well as photoconductivity.

Postsynthesis Transformation of Insulating Cs4PbBr6 Nanocrystals into Bright Perovskite CsPbBr3 through Physical and Chemical Extraction of CsBr.

Science.gov (United States)

Palazon, Francisco; Urso, Carmine; De Trizio, Luca; Akkerman, Quinten; Marras, Sergio; Locardi, Federico; Nelli, Ilaria; Ferretti, Maurizio; Prato, Mirko; Manna, Liberato

2017-10-13

Perovskite-related Cs 4 PbBr 6 nanocrystals present a "zero-dimensional" crystalline structure where adjacent [PbBr 6 ] 4- octahedra do not share any corners. We show in this work that these nanocrystals can be converted into "three-dimensional" CsPbBr 3 perovskites by extraction of CsBr. This conversion drastically changes the optoelectronic properties of the nanocrystals that become highly photoluminescent. The extraction of CsBr can be achieved either by thermal annealing (physical approach) or by chemical reaction with Prussian Blue (chemical approach). The former approach can be simply carried out on a dried film without addition of any chemicals but does not yield a full transformation. Instead, reaction with Prussian Blue in solution achieves a full transformation into the perovskite phase. This transformation was also verified on the iodide counterpart (Cs 4 PbI 6 ).

Elucidation and functional characterization of CsPSY and CsUGT promoters in Crocus sativus L.

Science.gov (United States)

Bhat, Archana; Mishra, Sonal; Kaul, Sanjana; Dhar, Manoj K

2018-01-01

The dried stigmas of Crocus sativus constitute the saffron, which is considered to be the costliest spice of the world. Saffron is valuable for its constituents, which are mainly apocarotenoids. In order to enhance the production of apocarotenoids, it is imperative to understand the regulation of apocarotenoid biosynthetic pathway. In C. sativus, although the pathway has been elucidated, the information regarding the regulation of the pathwaygenes is scanty. During the present investigation, the characterization of promoters regulating the expression of two important genes i.e. CsPSY and CsUGT was performed. We successfully cloned the promoters of both the genes, which were functionally characterized in Crocus sativus and Nicotiana tabaccum. In silico analysis of the promoters demonstrated the presence of several important cis regulatory elements responding tolight, hormonesand interaction with transcription factors (TFs). Further analysis suggested the regulation of CsPSY promoter by Abscisic acid (ABA) and that of CsUGT by Gibberellic acid (GA). In addition, we also observed ABA and GA mediated modulation in the expression of significant TFs and CsPSY and CsUGT transcripts. Overall, the study addresses issues related to regulation of key genes of apocarotenoid pathway in C.sativus.

Transfer of Chernobyl-derived 134Cs, 137Cs, 131I and 103Ru from flowers to honey and pollen

International Nuclear Information System (INIS)

Bunzl, K.; Kracke, W.

1988-01-01

The activity concentrations of 137 Cs, 134 Cs, 131 I and 103 Ru were determined separately in honey and pollen samples collected from a single bee colony during several months after the deposition of Chernobyl fallout. The source of each honey and pollen sample was determined by pollen analysis. Although the activity concentrations in honey and pollen varied with time, the concentrations of 137 Cs and 134 Cs were, in general, higher in pollen than in honey. For 103 Ru and 131 I, these differences were comparatively small. The mean 131 I/ 137 Cs and 103 Ru/ 137 Cs ratios were about one order of magnitude higher in honey than in pollen. The mean 131 I/ 103 Ru ratio was about the same for honey and pollen. This observation, in the light of the corresponding nuclide ratios found in the deposition, suggests that 137 Cs, 134 Cs, 131 I and 103 Ru were taken up by the plant leaves and transported to nectar and pollen. The higher activity concentrations of 137 Cs and 134 Cs in pollen, relative to honey, indicate that these radionuclides behave analogously to potassium, which is also found in higher quantities in pollen. (author)

Relative injectivity and CS-modules

Directory of Open Access Journals (Sweden)

Mahmoud Ahmed Kamal

1994-01-01

Full Text Available In this paper we show that a direct decomposition of modules M⊕N, with N homologically independent to the injective hull of M, is a CS-module if and only if N is injective relative to M and both of M and N are CS-modules. As an application, we prove that a direct sum of a non-singular semisimple module and a quasi-continuous module with zero socle is quasi-continuous. This result is known for quasi-injective modules. But when we confine ourselves to CS-modules we need no conditions on their socles. Then we investigate direct sums of CS-modules which are pairwise relatively inective. We show that every finite direct sum of such modules is a CS-module. This result is known for quasi-continuous modules. For the case of infinite direct sums, one has to add an extra condition. Finally, we briefly discuss modules in which every two direct summands are relatively inective.

Spectroscopic Peculiarity of the Herbig Be Star HD 259431

Science.gov (United States)

Pogodin, M. A.; Pavlovskij, S. E.; Drake, N. A.; Beskrovnaya, N. G.; Kozlova, O. V.; Alekseev, I. Yu.; Borges Fernandes, M.; Pereira, C. B.; Valyavin, G.

2017-06-01

High-resolution spectra of the Herbig Be star HD 259431 obtained in 2010-2016 at three observatories (Crimean AO, ESO in Chile, and OAN SPN in Mexico) are analysed. The object demonstrates a very rich emission line profile spectrum. The bulk of the lines exhibit double-peaked emission profiles and originate in the gaseous disk. The atmospheric lines are unusually shallow, and majority of them are distorted by the circumstellar (CS) contribution. Moreover, we have revealed that they are overlapped with an additional continuum emission. Using the observed ratio of the equivalent widths of two He I λ 4009 and 4026 lines, we estimated the spectral type of the object as B5 V. We also constructed the spectral energy distribution of the additional continuum using wide wings of the atmospheric Hβ-Hɛ lines free of the CS contribution. The continuum corresponds to the blue part of the black body spectrum. The Hβ - Hɛ Balmer emission lines show very variable profiles looking as either of P Cyg-type or a double-peaked emission line with a depression of the red wing. We found the period of this variability P = 2.630d and interpreted it as a sign of a rotating magnetosphere of the star with the magnetic axis inclined to the rotation axis. At different phases of rotation, the observer can see either an accretion flow at high magnetic latitudes or a wind zone at lower latitudes. We also estimated the inclination of the rotation axis i = 52°±1°.

The distribution of {sup 137}Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden

Energy Technology Data Exchange (ETDEWEB)

Vinichuk, M., E-mail: mykhailo.vinichuk@mark.slu.s [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Department of Ecology, Zhytomyr State Technological University, 103 Chernyakhovsky Street, 10005 Zhytomyr (Ukraine); Johanson, K.J. [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Rydin, H. [Department of Plant Ecology, Evolutionary Biology Centre, Uppsala University, Norbyvaegen 18D, SE-752 36 Uppsala (Sweden); Rosen, K. [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden)

2010-02-15

We record the distribution of {sup 137}Cs, K, Rb and Cs within individual Sphagnum plants (down to 20 cm depth) as well as {sup 137}Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris{sup 137}Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher {sup 137}Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of {sup 137}Cs within the plants. The patterns of {sup 137}Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The {sup 137}Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10 cm) of the plant (r = 0.50). The strongest correlations were revealed between {sup 137}Cs and Rb (r = 0.89), and between {sup 137}Cs and stable Cs (r = 0.84). This suggests similarities between {sup 137}Cs and Rb in uptake and relocation within the Sphagnum, but that {sup 137}Cs differs from K.

Derivation of 137Cs deposition density from measurement of 137Cs inventories in undisturbed soils

International Nuclear Information System (INIS)

Hien, P.D.; Hiep, H.T.; Quang, N.H.; Huy, N.Q.; Binh, N.T.; Hai, P.S.; Long, N.Q.; Bac, V.T

2012-01-01

The 137 Cs inventories in undisturbed soils were measured for 292 locations across the territory of Vietnam. the logarithmic inventory values were regressed against characteristics of sampling sites, such as geographical coordinates, annual rainfall and physico-chemical parameters of soil. The regression model containing latitude and annual rainfall as determinants could explain 76% of the variations in logarithmic inventory values across the territory. The model part was interpreted as the logarithmic 137 Cs deposition density. At the 95% confidence level, 137 Cs deposition density could be predicted be the model ± 7% relative uncertainty. the latitude mean 137 Cs deposition density increases northward from 237 Bq m -2 to 1097 Bq m -2 , while the corresponding values derived from the UNSCEAR (1969) global pattern are 300 Bq m -2 and 600 Bq m -2 . High 137 Cs inputs were found in high-rainfall areas in northern and central parts of the territory. (author)

BINARY CENTRAL STARS OF PLANETARY NEBULAE DISCOVERED THROUGH PHOTOMETRIC VARIABILITY. II. MODELING THE CENTRAL STARS OF NGC 6026 AND NGC 6337

International Nuclear Information System (INIS)

Hillwig, Todd C.; Bond, Howard E.; Afsar, Melike; De Marco, Orsola

2010-01-01

Close-binary central stars of planetary nebulae (CSPNe) provide an opportunity to explore the evolution of PNe, their shaping, and the evolution of binary systems undergoing a common-envelope phase. Here, we present the results of time-resolved photometry of the binary central stars (CSs) of the PNe NGC 6026 and NGC 6337 as well as time-resolved spectroscopy of the CS of NGC 6026. The results of a period analysis give an orbital period of 0.528086(4) days for NGC 6026 and a photometric period of 0.1734742(5) days for NGC 6337. In the case of NGC 6337, it appears that the photometric period reflects the orbital period and that the variability is the result of the irradiated hemisphere of a cool companion. The inclination of the thin PN ring is nearly face-on. Our modeled inclination range for the close central binary includes nearly face-on alignments and provides evidence for a direct binary-nebular shaping connection. For NGC 6026, however, the radial-velocity curve shows that the orbital period is twice the photometric period. In this case, the photometric variability is due to an ellipsoidal effect in which the CS nearly fills its Roche lobe and the companion is most likely a hot white dwarf. NGC 6026 then is the third PN with a confirmed central binary where the companion is compact. Based on the data and modeling using a Wilson-Devinney code, we discuss the physical parameters of the two systems and how they relate to the known sample of close-binary CSs, which comprise 15%-20% of all PNe.

Examination of the role of CS{sub 2} in the CS{sub 2}/NMP mixed solvents to coal extraction

Energy Technology Data Exchange (ETDEWEB)

Shui, Hengfu; Wang, Zhicai [School of Chemistry and Chemical Engineering, Anhui University of Technology, 243002 Maanshan Anhui (China); Gao, Jinsheng [Department of Energy Resources and Chemical Engineering, East China University of Science & amp; Technology, 200237 Shanghai (China)

2006-02-15

The roles of CS{sub 2} in the CS{sub 2}/NMP mixed solvent to coal extraction and solubilization were investigated in this study. There was little effect of removing of CS{sub 2} from the solutions on the solubilities of UF coal extract and pyridine insoluble (PI) of the extract in the NMP/CS{sub 2} mixed solvent, suggesting that NMP has high enough solubilities to the UF coal extract and PI. Six Argonne different rank coals were extracted with the CS{sub 2}/NMP mixed solvent and NMP, respectively. It was found that the extraction yield difference between NMP and CS{sub 2}/NMP mixed solvent for UF coal is largely deviated from the curve obtained for the other 5 coals, suggesting that the pre-swelling of CS{sub 2} in the mixed solvent may be one of important roles for high extraction yield of UF coal in the CS{sub 2}/NMP mixed solvent. FTIR indicated that there was a strong interaction between CS{sub 2} and NMP in the CS{sub 2}/NMP mixed solvent of 1:1 volume ratio, which made the strong absorbance at 2156 cm{sup -1} in the FTIR spectra, and this interaction may disrupt the dipole based association of NMP thus making the CS{sub 2}/NMP mixed solvent lower viscosity, to penetrate more quickly into the network structure of coal, resulting in the larger solvent partner (NMP) to enter and break the stronger coal-coal interactions. (author)

Transformation of Sintered CsPbBr3 Nanocrystals to Cubic CsPbI3 and Gradient CsPbBrxI3-x through Halide Exchange.

Science.gov (United States)

Hoffman, Jacob B; Schleper, A Lennart; Kamat, Prashant V

2016-07-13

All-inorganic cesium lead halide (CsPbX3, X = Br(-), I(-)) perovskites could potentially provide comparable photovoltaic performance with enhanced stability compared to organic-inorganic lead halide species. However, small-bandgap cubic CsPbI3 has been difficult to study due to challenges forming CsPbI3 in the cubic phase. Here, a low-temperature procedure to form cubic CsPbI3 has been developed through a halide exchange reaction using films of sintered CsPbBr3 nanocrystals. The reaction was found to be strongly dependent upon temperature, featuring an Arrhenius relationship. Additionally, film thickness played a significant role in determining internal film structure at intermediate reaction times. Thin films (50 nm) showed only a small distribution of CsPbBrxI3-x species, while thicker films (350 nm) exhibited much broader distributions. Furthermore, internal film structure was ordered, featuring a compositional gradient within film. Transient absorption spectroscopy showed the influence of halide exchange on the excited state of the material. In thicker films, charge carriers were rapidly transferred to iodide-rich regions near the film surface within the first several picoseconds after excitation. This ultrafast vectorial charge-transfer process illustrates the potential of utilizing compositional gradients to direct charge flow in perovskite-based photovoltaics.

Neutron Stars and NuSTAR

Science.gov (United States)

Bhalerao, Varun

2012-05-01

My thesis centers around the study of neutron stars, especially those in massive binary systems. To this end, it has two distinct components: the observational study of neutron stars in massive binaries with a goal of measuring neutron star masses and participation in NuSTAR, the first imaging hard X-ray mission, one that is extremely well suited to the study of massive binaries and compact objects in our Galaxy. The Nuclear Spectroscopic Telescope Array (NuSTAR) is a NASA Small Explorer mission that will carry the first focusing high energy X-ray telescope to orbit. NuSTAR has an order-of-magnitude better angular resolution and has two orders of magnitude higher sensitivity than any currently orbiting hard X-ray telescope. I worked to develop, calibrate, and test CdZnTe detectors for NuSTAR. I describe the CdZnTe detectors in comprehensive detail here - from readout procedures to data analysis. Detailed calibration of detectors is necessary for analyzing astrophysical source data obtained by the NuSTAR. I discuss the design and implementation of an automated setup for calibrating flight detectors, followed by calibration procedures and results. Neutron stars are an excellent probe of fundamental physics. The maximum mass of a neutron star can put stringent constraints on the equation of state of matter at extreme pressures and densities. From an astrophysical perspective, there are several open questions in our understanding of neutron stars. What are the birth masses of neutron stars? How do they change in binary evolution? Are there multiple mechanisms for the formation of neutron stars? Measuring masses of neutron stars helps answer these questions. Neutron stars in high-mass X-ray binaries have masses close to their birth mass, providing an opportunity to disentangle the role of "nature" and "nurture" in the observed mass distributions. In 2006, masses had been measured for only six such objects, but this small sample showed the greatest diversity in masses

Correlations between potassium, rubidium and cesium ({sup 133}Cs and {sup 137}Cs) in sporocarps of Suillus variegatus in a Swedish boreal forest

Energy Technology Data Exchange (ETDEWEB)

Vinichuk, M., E-mail: Mykhailo.Vinichuk@slu.s [Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Department of Ecology, Zhytomyr State Technological University, 103 Cherniakhovsky Str., 10005 Zhytomyr (Ukraine); Rosen, K.; Johanson, K.J. [Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Dahlberg, A. [Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences, P.O. Box 7026, 750 07 Uppsala (Sweden)

2011-04-15

An analysis of sporocarps of ectomycorrhizal fungi Suillus variegatus assessed whether cesium ({sup 133}Cs and {sup 137}Cs) uptake was correlated with potassium (K) or rubidium (Rb) uptake. The question was whether intraspecific correlations of Rb, K and {sup 133}Cs mass concentrations with {sup 137}Cs activity concentrations in sporocarps were higher within, rather than among, different fungal species, and if genotypic origin of sporocarps within a population affected uptake and correlation. Sporocarps (n = 51) from a Swedish forest population affected by the fallout after the Chernobyl accident were studied. The concentrations were 31.9 {+-} 6.79 g kg{sup -1} for K (mean {+-} SD, dwt), 0.40 {+-} 0.09 g kg{sup -1} for Rb, 8.7 {+-} 4.36 mg kg{sup -1} for {sup 133}Cs and 63.7 {+-} 24.2 kBq kg{sup -1} for {sup 137}Cs. The mass concentrations of {sup 133}Cs correlated with {sup 137}Cs activity concentrations (r = 0.61). There was correlation between both {sup 133}Cs concentrations (r = 0.75) and {sup 137}Cs activity concentrations (r = 0.44) and Rb, but the {sup 137}Cs/{sup 133}Cs isotopic ratio negatively correlated with Rb concentration. Concentrations of K and Rb were weakly correlated (r = 0.51). The {sup 133}Cs mass concentrations, {sup 137}Cs activity concentrations and {sup 137}Cs/{sup 133}Cs isotopic ratios did not correlate with K concentrations. No differences between, within or, among genotypes in S. variegatus were found. This suggested the relationships between K, Rb, {sup 133}Cs and {sup 137}Cs in sporocarps of S. variegatus is similar to other fungal species. - Highlights: {yields} We studied uptake of Cs ({sup 133}Cs and {sup 137}Cs), K and Rb by Suillus variegates sporocarps. {yields} Genotypic origin of fungus did not affect uptake of studied elements (isotopes). {yields} Genotypic origin did not affect correlation between Cs ({sup 133}Cs and {sup 137}Cs), K and Rb.

137Cs in northern Adriatic sediments

International Nuclear Information System (INIS)

Barisic, D.; Lulic, S.; Vdovic, N.; Vertacnik, A.; Juracic, M.

1996-01-01

The activity of 137 Cs in shallow northern Adriatic sediments was obtained on the basis of measurement results from 25 sediment box cores, sampled during the Adriatic Scientific COoperation Program (ASCOP) 16 cruise in the summer 1990. 137 Cs was determined in surface sediments (0-3 cm) and 12-15 cm-deep sediment. It was found that the lowest caesium concentrations correspond to sands, which are spread along the Croatian coast. Parallel to the Italian coast, 137 Cs concentrations in pelites are the highest. It seems that the influence of Po River is significant for 137 Cs activities in recent marine sediments along Italian coast south of Po River delta. Significantly higher 137 Cs activities in 0-3 cm sediment layer can be attributed to the deposition caused by Chernobyl accident. (author)

137Cs metabolism in pregnant women

International Nuclear Information System (INIS)

Melo, D.R.; Lipsztein, J.L.; Oliveira, C.A.N.; Bertelli, L.

2000-01-01

Data from two pregnant women contaminated with 137 Cs, body burdens of 0.2 and 300 MBq, respectively at the time of the Goiania accident, were compared. The first one, with lower body burden was exposed during the fourth month of pregnancy, while the second became pregnant three years and eight months after 137 Cs intake. For the first woman 137 Cs concentrations were equal for the mother, infant and placenta, indicating an easy and homogeneous transport of 137 Cs from mother to foetus. The whole body monitoring data from the second woman, who became pregnant four years after intake, did not show a reduction in biological half-life during the pregnancy. Cs concentration in the mother was found to be 13 times higher than in the infant. One possible reason for this result is that four years after intake, Cs is supposed to be concentrated mainly in skeletal muscle tissue. During the pregnancy the blood flux becomes higher in most of the organs and tissues except brain, liver and skeletal muscle tissue. (author)

Estimation of average burnup of damaged fuels loaded in Fukushima Dai-ichi reactors by using the 134Cs/137Cs ratio method

International Nuclear Information System (INIS)

Endo, T.; Sato, S.; Yamamoto, A.

2012-01-01

Average burnup of damaged fuels loaded in Fukushima Dai-ichi reactors is estimated, using the 134 Cs/ 137 Cs ratio method for measured radioactivities of 134 Cs and 137 Cs in contaminated soils within the range of 100 km from the Fukushima Dai-ichi nuclear power plants. As a result, the measured 134 Cs/ 137 Cs ratio from the contaminated soil is 0.996±0.07 as of March 11, 2011. Based on the 134 Cs/ 137 Cs ratio method, the estimated burnup of damaged fuels is approximately 17.2±1.5 [GWd/tHM]. It is noted that the numerical results of various calculation codes (SRAC2006/PIJ, SCALE6.0/TRITON, and MVP-BURN) are almost the same evaluation values of 134 Cs/ 137 Cs ratio with same evaluated nuclear data library (ENDF-B/VII.0). The void fraction effect in depletion calculation has a major impact on 134 Cs/ 137 Cs ratio compared with the differences between JENDL-4.0 and ENDF-B/VII.0. (authors)

Waste forms based on Cs-loaded silicotitanates

International Nuclear Information System (INIS)

Balmer, M.L.; Bunker, B.C.

1995-04-01

Silicotitanate ion exchange materials are being considered for removal of radioactive Cs and Sr from tank wastes at the Hanford site. The phase evolution as a function of heat treatment temperature for several sol gel derived compositions within the Cs 2 O-SiO 2 -TiO 2 system was investigated, in order to determine if an adequate waste form can be achieved by direct thermal conversion. The Cs leach rates and Cs loss during heat treatment of select materials were measured. Some compositions which contain large amounts of Ti melt to form a glass with reasonably low aqueous leach rates. A new Cs-silicotitanate material with a structure isomorphous to pollucite was discovered. This material forms at low temperatures (700--800 C) where Cs volatility is negligible. The silicotitanate-pollucite exhibits extremely low leach rates (1.42 g/m 2 day ) at 90 C, and has been identified as a promising waste form for Cs containment

Hybridization of Single Nanocrystals of Cs4PbBr6 and CsPbBr3

OpenAIRE

Weerd, Chris de; Lin, Junhao; Gomez, Leyre; Fujiwara, Yasufumi; Suenaga, Kazutomo; Gregorkiewicz, Tom

2017-01-01

Nanocrystals of all-inorganic cesium lead halide perovskites (CsPbX3, X = Cl, Br, I) feature high absorption and efficient narrow-band emission which renders them promising for future generation of photovoltaic and optoelectronic devices. Colloidal ensembles of these nanocrystals can be conveniently prepared by chemical synthesis. However, in the case of CsPbBr3, its synthesis can also yield nanocrystals of Cs4PbBr6 and the properties of the two are easily confused. Here, we investigate in de...

Behaviour of 134Cs in the aquatic ecosystems

International Nuclear Information System (INIS)

Xu Yinliang; Chen Chuanqun

1992-07-01

The diminution of 134 Cs in the aquatic phases and the absorption of 134 Cs by aquatic lives observe the exponential expression. i.e. Y Ae be . The relationships between the enrichment factor of 134 Cs(K) and the time(t) in the aquatic lives can be represented by a linear equation, K A + Bt. The value of K in the Alternanthera philoxeroides was about 560. That can be used for monitoring and purifying the water phase contaminated by 134 Cs. Fish can absorb 134 Cs from water phase and store it in liver and kidney. The specific activity of 134 Cs in fish flesh was low but the percentage of radioactivity was high that was about 30% of total radioactivity in the fish. River mud can strongly absorb 134 Cs and reduce the absorption by aquatic lives. It is a good adsorbent and purifying agent with low cost for treatment of 134 Cs. The K + can prevent aquatic lives from absorbing Cs + because of antagonistic function

New technology of CRDM-CS

International Nuclear Information System (INIS)

Yasushi Nozaki; Hiroyuki Ukon; Toshiaki Matsumura; Yoshihiro Sakurai; Sigenori Hatazawa; Hitoshi Yamagishi; Katsuji Kaneizumi; Hisashi Yasuda

2005-01-01

Control Rod Drive Mechanism Control System (CRDM-CS) for PWR Nuclear Power Plant was developed as a domestic product in 1975 and it has been applied to the commercial power plants. Since then, the CRDM-CS has been continuously improved through applying a double-hold-system, an intensified monitoring system, etc. As the result of these modifications unexpected rod drops have never occurred more than ten years in Japanese PWR plants. The system is still so high reliable, however, the technologies of employed devices are old-fashioned and we face on the difficulty to keep spare-parts these days. On the other hand, there are new movements to seek after the plant life extension of 60 years. These situations require a modernized CRDM-CS to accomplish the reliability in accordance to the plant life extension. to comply the above-mentioned object we developed a new CRDM-CS applied with following technologies; 1) Digitalized logic cabinet, 2) I.G.B.T in the main circuit of power cabinet, 3) Standardized cabinet by employing the unit structure, 4) Unnecessary DC hold power cabinet. These measures can play an important role in cost cutting and space reduction in replacing CRDM-CS. The concepts in developing the new CRDM-CS, the applied technologies to the power cabinet, the system structure and characteristics of the logic cabinet and the outline of verification test and result are discussed in this paper. (authors)

Coefficients of distribution and accumulation of K, Rb, Cs and 137Cs in the intensive poultry breeding cycle

International Nuclear Information System (INIS)

Djuric, G.; Ajdacic, N.; Institut za Nuklearne Nauke Boris Kidric, Belgrade

1984-01-01

The concentration of K,Rb,Cs and the activity level of Cs-137 in samples from the intensive poultry breeding cycle (feed, meat, eggs), under the condition of chronic alimentary contamination is presented. Concentrations of Cs and Rb were determined by non-destructive neutron activation analysis, concentration of K by atomic absorption flame photometry and activity of Cs-137 by gamma spectrometric analysis. On the basis of these results, coefficients of distribution and accumulation were calculated. The distribution coefficients of the analysed stable isotopes in meat have values close to 1, whereas for various parts of egg these coefficients vary between 0.5 and 1.5. Significant differences in Cs-137 distribution in various parts of egg were established. The values of accumulation coefficients indicate that all analysed elements selectively accumulate in the meat of young birds (broilers), and Cs-137 accumulates in the egg white as well. (orig.)

Intravesical administration of combined hyaluronic acid (HA) and chondroitin sulfate (CS) for the treatment of female recurrent urinary tract infections: a European multicentre nested case-control study.

Science.gov (United States)

Ciani, Oriana; Arendsen, Erik; Romancik, Martin; Lunik, Richard; Costantini, Elisabetta; Di Biase, Manuel; Morgia, Giuseppe; Fragalà, Eugenia; Roman, Tomaskin; Bernat, Marian; Guazzoni, Giorgio; Tarricone, Rosanna; Lazzeri, Massimo

2016-03-31

To compare the clinical effectiveness of the intravesical administration of combined hyaluronic acid and chondroitin sulfate (HA+CS) versus current standard management in adult women with recurrent urinary tract infections (RUTIs). A European Union-based multicentre, retrospective nested case-control study. 276 adult women treated for RUTIs starting from 2009 to 2013. Patients treated with either intravesical administration of HA+CS or standard of care (antimicrobial/immunoactive prophylaxis/probiotics/cranberry). The primary outcome was occurrence of bacteriologically confirmed recurrence within 12 months. Secondary outcomes were time to recurrence, total number of recurrences, health-related quality of life and healthcare resource consumption. Crude and adjusted results for unbalanced characteristics are presented. 181 patients treated with HA+CS and 95 patients treated with standard of care from 7 centres were included. The crude and adjusted ORs (95% CI) for the primary end point were 0.77 (0.46 to 1.28) and 0.51 (0.27 to 0.96), respectively. However, no evidence of improvement in terms of total number of recurrences (incidence rate ratio (95% CI), 0.99 (0.69 to 1.43)) or time to first recurrence was seen (HR (95% CI), 0.99 (0.61 to 1.61)). The benefit of intravesical HA+CS therapy improves when the number of instillations is ≥ 5. Our results show that bladder instillations of combined HA+CS reduce the risk of bacteriologically confirmed recurrences compared with the current standard management of RUTIs. Total incidence rates and hazard rates were instead non-significantly different between the 2 groups after adjusting for unbalanced factors. In contrast to what happens with antibiotic prophylaxis, the effectiveness of the HA+CS reinstatement therapy improves over time. NCT02016118. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Using Multiple Paths in NoCs for Guaranteed Resource Allocation and Improved Best Effort Performance in NoCs.

NARCIS (Netherlands)

Ovadia, I.; Ha, Y.; Corporaal, H.

2005-01-01

Networks-on-Chips (NoCs) provide communication platforms to Systems-on-Chips (SoCs). In NoCs, channels are generally shared between traffic flows, resulting in contention. However, certain flows require delivery guarantees. Differentiated quality-of-service (QoS) is achieved by providing guaranteed

Modeling radionuclide Cs and C dynamics in an artificial forest ecosystem in Japan -FoRothCs ver1.0-

Directory of Open Access Journals (Sweden)

Kazuya eNishina

2015-09-01

Full Text Available Predicting the environmental fate of Cs radionuclides in forest ecosystems is important for the effective management and assessment of radioactively contaminated forest areas. A large proportion of the radioactively contaminated areas in Japan consist of forest ecosystems, and most of these areas are artificial forests that are used for timber production (e.g., Japanese cedar (Cryptomeria japonica and red pine (Pinus densiflora. Determining the long-term redistribution of 137Cs in forest ecosystems is important for estimating human doses and understanding the ecological impacts and challenges associated with managing contaminated forests. To facilitate the management and 137Cs decontamination of these forests, we developed a new open-source 137Cs cycling model, ForRothCs, that considers C cycling within forests, as well as biomass production and soil decomposition processes. For the 137Cs inventory, this model estimates the dynamics (Bq m−2 and activity (Bq kg−2 of 137Cs on a decadal time scale, primarily in the leaves, branches, stems, litter layer, and the soil. This model is based on the biomass production and the dynamics of the C cycle models. We tested the model by considering a simple scenario of forest management, i.e., thinning and harvesting, for the first five years following a fallout event. The results showed that these activities have a limited impact on the 137Cs inventory due to the rapid migration of 137Cs from vegetation to soil. Our projections also showed the examined forest management practices resulted in reduced litterfall, which in turn reduced C input to the forest floor and increased the concentration of 137Cs in the litterfall and soil organic layer. Although further validation of the ForRothCs model is required using field observation data, the model can be used to evaluate long-term 137Cs dynamics associated with commonly used forest and decontamination management scenarios.

Luminescent CsPbI.sub.3./sub. and Cs.sub.4./sub.PbI.sub.6./sub. aggregates in annealed CsI:Pb crystals

Czech Academy of Sciences Publication Activity Database

Babin, V.; Fabeni, P.; Nikl, Martin; Nitsch, Karel; Pazzi, G.P.; Zazubovich, S.

2001-01-01

Roč. 226, č. 2 (2001), s. 419-428 ISSN 0370-1972 Institutional research plan: CEZ:AV0Z1010914 Keywords : CsPbI 3 * Cs 4 PbI 6 * nanoaggregates * luminescence Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.873, year: 2001

Cs2UPd3Se6

Directory of Open Access Journals (Sweden)

George N. Oh

2011-02-01

Full Text Available Dicaesium uranium(IV tripalladium(II hexaselenide, Cs2UPd3Se6, crystallizes in the space group Fmmm in the Ba2NaCu3O6 structure type. The asymmetric unit comprises the following atoms with site symmetries as shown: U1 (mm2, Cs1 (222, Cs2 (m2m, Pd1 (.m., Pd2 (2mm, Se1 (m.., and Se2 (1. This layered structure contains six edge-sharing square-planar [PdSe4] units that form a hexagon. These, in turn, edge-share with [USe6] trigonal–prismatic units, forming an extended layer parallel to (010. The layers are stacked along [010]. They are staggered, and are separated by the Cs atoms. The Cs atoms are either coordinated in a square antiprism of Se atoms or are ten-coordinate, with one square face and the opposite face hexagonal.

Monte Carlo simulation of star/linear and star/star blends with chemically identical monomers

Energy Technology Data Exchange (ETDEWEB)

Theodorakis, P E [Department of Materials Science and Engineering, University of Ioannina, 45110 Ioannina (Greece); Avgeropoulos, A [Department of Materials Science and Engineering, University of Ioannina, 45110 Ioannina (Greece); Freire, J J [Departamento de Ciencias y Tecnicas FisicoquImicas, Universidad Nacional de Educacion a Distancia, Facultad de Ciencias, Senda del Rey 9, 28040 Madrid (Spain); Kosmas, M [Department of Chemistry, University of Ioannina, 45110 Ioannina (Greece); Vlahos, C [Department of Chemistry, University of Ioannina, 45110 Ioannina (Greece)

2007-11-21

The effects of chain size and architectural asymmetry on the miscibility of blends with chemically identical monomers, differing only in their molecular weight and architecture, are studied via Monte Carlo simulation by using the bond fluctuation model. Namely, we consider blends composed of linear/linear, star/linear and star/star chains. We found that linear/linear blends are more miscible than the corresponding star/star mixtures. In star/linear blends, the increase in the volume fraction of the star chains increases the miscibility. For both star/linear and star/star blends, the miscibility decreases with the increase in star functionality. When we increase the molecular weight of linear chains of star/linear mixtures the miscibility decreases. Our findings are compared with recent analytical and experimental results.

Monte Carlo simulation of star/linear and star/star blends with chemically identical monomers

Science.gov (United States)

Theodorakis, P. E.; Avgeropoulos, A.; Freire, J. J.; Kosmas, M.; Vlahos, C.

2007-11-01

The effects of chain size and architectural asymmetry on the miscibility of blends with chemically identical monomers, differing only in their molecular weight and architecture, are studied via Monte Carlo simulation by using the bond fluctuation model. Namely, we consider blends composed of linear/linear, star/linear and star/star chains. We found that linear/linear blends are more miscible than the corresponding star/star mixtures. In star/linear blends, the increase in the volume fraction of the star chains increases the miscibility. For both star/linear and star/star blends, the miscibility decreases with the increase in star functionality. When we increase the molecular weight of linear chains of star/linear mixtures the miscibility decreases. Our findings are compared with recent analytical and experimental results.

Monte Carlo simulation of star/linear and star/star blends with chemically identical monomers

International Nuclear Information System (INIS)

Theodorakis, P E; Avgeropoulos, A; Freire, J J; Kosmas, M; Vlahos, C

2007-01-01

The effects of chain size and architectural asymmetry on the miscibility of blends with chemically identical monomers, differing only in their molecular weight and architecture, are studied via Monte Carlo simulation by using the bond fluctuation model. Namely, we consider blends composed of linear/linear, star/linear and star/star chains. We found that linear/linear blends are more miscible than the corresponding star/star mixtures. In star/linear blends, the increase in the volume fraction of the star chains increases the miscibility. For both star/linear and star/star blends, the miscibility decreases with the increase in star functionality. When we increase the molecular weight of linear chains of star/linear mixtures the miscibility decreases. Our findings are compared with recent analytical and experimental results

Source of the violet depression in carbon stars (a study of the Balmer decrement in carbon L.P.V.s)

International Nuclear Information System (INIS)

Orlati, M.A.

1985-01-01

In an effort to determine the nature of the agent(s) of the violet depression in N-type stars through the behavior of their Balmer decrement, slit spectrograms of two C, one CS, two S (all reported to have the violet depression) and one M type LPVs were repeatedly taken between May 1983 and November 1984. The observed phase related changes in the Balmer decrement exclude the possibility that the absorbers are circumstellar because the emission region in the best-observed star is seen to rise through the opacity source. The exact nature and number of kinds of absorbers remains to be determined

Properties of Cs-intercalated single wall carbon nanotubes investigated by 133Cs Nuclear Magnetic resonance

KAUST Repository

Schmid, Marc R.; Mahfouz, Remi; Bouhrara, Mohamed; Saih, Youssef; Mehring, Michael; Basset, Jean-Marie; Goze-Bac, Christophe; Abou-Hamad, Edy

2012-01-01

present within the carbon nanotube bundles. At high concentrations, the Cs (β)+ ions seem to occupy well defined positions relative to the carbon lattice. As a matter of fact, the Korringa relaxation behavior suggests a strong hyperfine coupling between Cs

Potential value of Cs-137 capsules

Energy Technology Data Exchange (ETDEWEB)

Bloomster, C.H.; Brown, D.R.; Bruno, G.A.; Hazelton, R.F.; Hendrickson, P.L.; Lezberg, A.J.; Tingey, G.L.; Wilfert, G.L.

1985-04-01

We determined the value of Cs-137 compared to Co-60 as a source for the irradiation of fruit (apples and cherries), pork and medical supplies. Cs-137, in the WESF capsule form, had a value of approximately $0.40/Ci as a substitute for Co-60 priced at approximately $1.00/Ci. The comparison was based on the available curies emitted from the surface of each capsule. We developed preliminary designs for fourteen irradiation facilities; seven were based on Co-60 and seven were based on Cs-137. These designs provided the basis for estimating capital and operating costs which, in turn, provided the basis for determining the value of Cs-137 relative to Co-60 in these applications. We evaluated the effect of the size of the irradiation facility on the value of Cs-137. The cost of irradiation is low compared to the value of the product. Irradiation of apples for disinfestation costs $.01 to .02 per pound. Irradiation for trichina-safe pork costs $.02 per pound. Irradiation of medical supplies for sterilization costs $.07 to .12 per pound. The cost of the irradiation source, either Co-60 or Cs-137, contributed only a minor amount to the total cost of irradiation, about 5% for the fruit and hog cases and about 20% for the medical supply cases. We analyzed the sensitivity of the irradiation costs and Cs-137 value to several key assumptions.

Potential value of Cs-137 capsules

International Nuclear Information System (INIS)

Bloomster, C.H.; Brown, D.R.; Bruno, G.A.; Hazelton, R.F.; Hendrickson, P.L.; Lezberg, A.J.; Tingey, G.L.; Wilfert, G.L.

1985-04-01

We determined the value of Cs-137 compared to Co-60 as a source for the irradiation of fruit (apples and cherries), pork and medical supplies. Cs-137, in the WESF capsule form, had a value of approximately $0.40/Ci as a substitute for Co-60 priced at approximately $1.00/Ci. The comparison was based on the available curies emitted from the surface of each capsule. We developed preliminary designs for fourteen irradiation facilities; seven were based on Co-60 and seven were based on Cs-137. These designs provided the basis for estimating capital and operating costs which, in turn, provided the basis for determining the value of Cs-137 relative to Co-60 in these applications. We evaluated the effect of the size of the irradiation facility on the value of Cs-137. The cost of irradiation is low compared to the value of the product. Irradiation of apples for disinfestation costs $.01 to .02 per pound. Irradiation for trichina-safe pork costs $.02 per pound. Irradiation of medical supplies for sterilization costs $.07 to .12 per pound. The cost of the irradiation source, either Co-60 or Cs-137, contributed only a minor amount to the total cost of irradiation, about 5% for the fruit and hog cases and about 20% for the medical supply cases. We analyzed the sensitivity of the irradiation costs and Cs-137 value to several key assumptions

Water culture of the rice containing Cs-137

International Nuclear Information System (INIS)

Choi, Yong Ho; Keum, Dong Kwon; Lim, Kwang Muk; Jun, In; Park, Doo Won

2008-10-01

Pot experiments were carried out in a greenhouse in order to produce Cs-137-containing rice seeds as a source material for use in manufacturing reference rice samples of a high Cs-137 activity. Two kinds of soil were used and two pots were prepared for each kind of soil. Rice plants were water-cultured in the pots and Cs-137 was applied to the surface water to induce a Cs-137 contamination of rice seeds via a plant uptake of Cs-137. Mature rice plants were harvested and Cs-137-containing rice seeds were obtained after some treatment of the harvested plants. These produced rice seeds are going to be provided for the KRISS so as to be used in manufacturing reference rice samples for Cs-137

Thermal, conductivity, NMR, and Raman spectroscopic measurements and phase diagram of the Cs2S2O7-CsHSO4 system

DEFF Research Database (Denmark)

Rasmussen, Søren Birk; Hama, Hind; Lapina, Olga

2003-01-01

The conductivity of the binary system CS2S2O7-CsHSO4 has been measured at 20 different molten compositions in the full composition range and in the temperature range 430-750 K. From the obtained liquidus-solidus phase transition temperatures, the phase diagram has been constructed. It is of the s......The conductivity of the binary system CS2S2O7-CsHSO4 has been measured at 20 different molten compositions in the full composition range and in the temperature range 430-750 K. From the obtained liquidus-solidus phase transition temperatures, the phase diagram has been constructed...... from the NMR measurements on CsHSO4, CS2S2O7, and Cs2S2O7-CsHSO4 mixtures. For 11 selected compositions covering the entire composition range of the CS2S2O7-CsHSO4 binary system, the conductivity of the molten state has been expressed by equations of the form k(X) = A(X) + B(X)(T - T-m) + C(X)(T - T...

The Role Of Gender In Asking Questions At Cool Stars 18 And 19

Science.gov (United States)

Schmidt, Sarah J.; Douglas, Stephanie; Gosnell, Natalie M.; Muirhead, Philip S.; Booth, Rachel S.; Davenport, James R. A.; Mace, Gregory N.

2016-12-01

We examine the gender balance of the 18th and 19th meetings of the Cambridge Workshop on Cool Stellar Systems and the Sun (CS18 and CS19). The percent of female attendees at both meetings (31% at CS18 and 37% at CS19) was higher than the percent of women in the American Astronomical Society (25%) and the International Astronomical Union (18%). The representation of women in Cool Stars as SOC members, invited speakers, and contributed speakers was similar to or exceeded the percent of women attending the meetings. We requested that conference attendees assist in a project to collect data on the gender of astronomers asking questions after talks. Using this data, we found that men were over-represented (and women were under-represented) in the question sessions after each talk. Men asked 79% of the questions at CS18 and 75% of the questions at CS19, but were 69% and 63% of the attendees respectively. Contrary to findings from previous conferences, we did not find that the gender balance of questions was strongly affected by the session chair gender, the speaker gender, or the length of the question period. We also found that female and male speakers were asked a comparable number of questions after each talk. The contrast of these results from previous incarnations of the gender questions survey indicate that more data would be useful in understanding the factors that contribute to the gender balance of question askers. We include a preliminary set of recommendations based on this and other work on related topics, but also advocate for additional research on the demographics of conference participants. Additional data on the intersection of gender with race, seniority, sexual orientation, ability and other marginalized identities is necessary to fully address the role of gender in asking questions at conferences.

Determination of /sup 131/I, /sup 134/Cs, /sup 137/Cs in grass and cheese after Chernobyl accident in Austria

Energy Technology Data Exchange (ETDEWEB)

Teherani, D K

1987-09-14

Various samples from Styria (grass) and Salzburg (cheese) were analyzed for /sup 131/I, /sup 134/Cs and /sup 137/Cs concentration during April - July 1986 by ..gamma..-ray spectroscopy. The concentrations are reported in nCi kg/sup -1/ wet weight. The values found for /sup 131/I were 0.2-17.2 (grass), 0.1-0.5 (cheese), for /sup 134/Cs 1.1-6.2 (grass), 0.2-1.3 (cheese), for /sup 137/Cs 1.6-15.7 (grass), 0.3-2.2 (cheese). While radioactivity of /sup 131/I, /sup 134/Cs and /sup 137/Cs in cheese samples increased from May to June, it decreased in grass samples from May to July. (author) 5 refs

Neutron stars

International Nuclear Information System (INIS)

Irvine, J.M.

1978-01-01

The subject is covered in chapters entitled: introduction (resume of stellar evolution, gross characteristics of neutron stars); pulsars (pulsar characteristics, pulsars as neutron stars); neutron star temperatures (neutron star cooling, superfluidity and superconductivity in neutron stars); the exterior of neutron stars (the magnetosphere, the neutron star 'atmosphere', pulses); neutron star structure; neutron star equations of state. (U.K.)

Calculation of inelastic cross sections for H+ + Cs → H(n=2) + Cs+

International Nuclear Information System (INIS)

Valance, A.; Spiess, G.

1975-01-01

The cross sections for the processes H + +Cs → H(2p and 2s) +Cs + were calculated in the center of mass energy range 250--2400 eV using a simple pseudopotential formalism for the potential curves and coupling matrix elements and a perturbed stationary state (pss) formulation for the calculation of the cross sections. The results are found to be in reasonable agreement with experiment. (auth)

Influence of water management and fertilizer application on "1"3"7Cs and "1"3"3Cs uptake in paddy rice fields

International Nuclear Information System (INIS)

Wakabayashi, Shokichi; Itoh, Sumio; Kihou, Nobuharu; Matsunami, Hisaya; Hachinohe, Mayumi; Hamamatsu, Shioka; Takahashi, Shigeru

2016-01-01

Cesium-137 derived from the Tokyo Electric Power Company's Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident contaminated large areas of agricultural land in Eastern Japan. Previous studies before the accident have indicated that flooding enhances radiocesium uptake in rice fields. We investigated the influence of water management in combination with fertilizers on "1"3"7Cs concentrations in rice plants at two fields in southern Ibaraki Prefecture. Stable Cs ("1"3"3Cs) in the plants was also determined as an analogue for predicting "1"3"7Cs behavior after long-term aging of soil "1"3"7Cs. The experimental periods comprised 3 y starting from 2012 in one field, and 2 y from 2013 in another field. These fields were divided into three water management sections: a long-flooding section without midsummer drainage, and medial-flooding, and short-flooding sections with one- or two-week midsummer drainage and earlier end of flooding than the long-flooding section. Six or four types of fertilizer subsections (most differing only in potassium application) were nested in each water management section. Generally, the long-flooding treatment led to higher "1"3"7Cs and "1"3"3Cs concentrations in both straw and brown rice than medial- and short-flooding treatments, although there were some notable exceptions in the first experimental year at each site. Effects of differing potassium fertilizer treatments were cumulative; the effects on "1"3"7Cs and "1"3"3Cs concentrations in rice plants were not obvious in 2012 and 2013, but in 2014, these concentrations were highest where potassium fertilizer had been absent and lowest where basal dressings of K had been tripled. The relationship between "1"3"7Cs and "1"3"3Cs in rice plants was not correlative in the first experimental year at each site, but correlation became evident in the subsequent year(s). This study demonstrates a novel finding that omitting midsummer drainage and/or delaying drainage during the grain-filling period

Study of Cs recovery by extraction chromatography (2)

International Nuclear Information System (INIS)

Hoshi, Harutaka; Zhang, Anyun; Uchida, Hiromi; Kuraoka, Etsushu

2005-02-01

In order to apply CalixR14 extractant to extraction chromatography for Cs separation, basic characteristics of CalixR14 adsorbent were studied. CalixR14 impregnated resin and CalixR14 + TBP impregnated resin were prepared. CalixR14 extractant showed no adsorption for Cs by liquid-liquid extraction and CalixR14 impregnated resin also showed no adsorption for Cs. Therefore, it is concluded that CalixR14 itself has no affinity for Cs. On the other hand, Cs was adsorbed onto CalixR14-TBP impregnated resin from a concentrated nitric acid solution. The distribution coefficients of Cs were more than 10 cm 3 /g from 2 to 6 M nitric acid. While Rb showed week adsorption, Na, K, Sr and La showed no adsorption and separation factor was over 100. A slight amount of CalixR14 and TBP was leaked from impregnated resin into the aqueous phase. Separation from simulated liquid waste was carried out by using a column packed with CalixR14-TBP adsorbent. Na, K, Sr and La were not adsorbed onto the column, however, Cs and Rb were adsorbed onto the column. Cs and Rb were eluted from the column by water. Cs and Rb were quantitatively recovered. (author)

Vertical profile of 137Cs in soil.

Science.gov (United States)

Krstić, D; Nikezić, D; Stevanović, N; Jelić, M

2004-12-01

In this paper, a vertical distribution of 137Cs in undisturbed soil was investigated experimentally and theoretically. Soil samples were taken from the surroundings of the city of Kragujevac in central Serbia during spring-summer of 2001. The sampling locations were chosen in such a way that the influence of soil characteristics on depth distribution of 137Cs in soil could be investigated. Activity of 137Cs in soil samples was measured using a HpGe detector and multi-channel analyzer. Based on vertical distribution of 137Cs in soil which was measured for each of 10 locations, the diffusion coefficient of 137Cs in soil was determined. In the next half-century, 137Cs will remain as the source of the exposure. Fifteen years after the Chernobyl accident, and more than 30 years after nuclear probes, the largest activity of 137Cs is still within 10 cm of the upper layer of the soil. This result confirms that the penetration of 137Cs in soil is a very slow process. Experimental results were compared with two different Green functions and no major differences were found between them. While both functions fit experimental data well in the upper layer of soil, the fitting is not so good in deeper layers. Although the curves obtained by these two functions are very close to each other, there are some differences in the values of parameters acquired by them.

The 134Cs uptake by sunflower (Helianthus anuus, Less) cultivated on soil contaminated with 134Cs

International Nuclear Information System (INIS)

Poppy Intan Tjahaja; Putu Sukmabuana

2008-01-01

One of the methods for remediation of contaminated environment is phytoremediation techniques, i.e. the environmental remediation using plants. In this research the bioavailability of sunflower plant (Helianthus anuus, Less) in radiocaesium uptake from soil was studied for being considered as a phytoremediator later. Sunflower plants were cultivated on soil contaminated with 134 Cs with the concentrations of 29,3 kBq/kg ; 117,2 kBq/kg ; 557 kBq/kg for 45 days. As control the sunflowers were also cultivated on non contaminated soil. Observation was carried out every 5 days by sampling 3 plants and soils. The plant and soil samples were dried using infra red lamp for 24 hours, and then counted using gamma spectrometer. The counting results i.e. 134 Cs concentration on soil and plant parts were then analyzed to obtain transfer factor (TF) values. The highest TF values was reached on 26 th day, i.e. 0,87; 1,89 ; 2,82 for initial soil 134 Cs concentrations of 29,3 Bq/g ; 117,2 Bq/g ; 557 Bq/g, respectively. The TF values obtained expressed the capability of plants to accumulate 134 Cs from soils. The observation to the plants growth showed that the plants grew normally on the 134 Cs contaminated soil until the concentration of 557 Bq/g. The sunflower can be considered to be phytoremediator of andosol soil contaminated with Cs radionuclides. (author)

SR-XRF imaging of Cs highly accumulated in vegetables

International Nuclear Information System (INIS)

Nakai, Izumi; Oda, Nahoko; Terada, Yasuko

2011-01-01

Accumulation of Cs in vegetables was studied with regard to the remediation of radioactive Cs from a nuclear plant accident in Fukushima. It was found that Brassica oleracea var. capitata, Brassica campestris var. perviridis, and Lactuca sativa accumulated Cs to a level of more than 10000 ppm (dry weight) when they were cultivated in 1 mM Cs solution. Two-dimensional distributions of Cs were revealed by SR-XRF imaging showing a homogeneous distribution of Cs in the plant bodies. (author)

Radioecological studies of 137Cs in limnological ecosystems. Biochemical states of 137Cs accumulated in killifish (Medaka, Oryzias latipes) meat

International Nuclear Information System (INIS)

Miyake, Sadaaki; Motegi, Misako; Oosawa, Takashi; Nakazawa, Kiyoaki; Izumo, Yoshiro; Nakamura, Fumio.

1997-01-01

Biochemical states of 137 Cs accumulated in killifish's (Medaka, Oryzias latipes) meat were investigated in order to elucidate the accumulation mechanism of the radionuclide in goldfish, Carassius auratus auratus, examined in our preceding report. Most of 137 Cs radioactivity in the killifish's raw meat accumulated this radionuclide in the radioactive freshwater, were found in the non-protein nitrogenous compound (NPNC) fraction (>92%), also in the killifish's control raw meat mixed with 137 Cs, the difference between both meat samples was not clear. As the results of gel filtration profiles on Sephadex G-25 for the NPNC fraction of these meats, each only one radioactive peak was shown, also similar to 137 CsCl solution. Moreover, these peaks appeared at the same position. On the other hand, the peak positions absorbed at OD 280nm in the samples were different from those of each radioactive peak. It was so suggested that 137 Cs accumulated in the killifish's meat was shown not to be binding to protein's composition. Furthermore, as the results on thin-layer chromatography, ion-exchange resin chromatography and reaction with 137 Cs in samples and ammonium phosphomolybdate, 137 Cs in the NPNC fraction of the killifish's meat was not almost different from those of each control and 137 CsCl solution. (author)

Comparison of CsI(Tl) and CsI(Na) partially slotted crystals for high-resolution SPECT imaging

International Nuclear Information System (INIS)

Giokaris, N.; Loudos, G.; Maintas, D.; Karabarbounis, A.; Lembesi, M.; Spanoudaki, V.; Stiliaris, E.; Boukis, S.; Sakellios, N.; Karakatsanis, N.; Gektin, A.; Boyarintsev, A.; Pedash, V.; Gayshan, V.

2006-01-01

Dedicated systems based on Position Sensitive Photomultiplier Tubes (PSPMTs) coupled to scintillators, have been used over the past years for the construction of compact systems, suitable for applications such as small animal imaging and small organs imaging. Most of the proposed systems are based on fully pixelized scintillators. Previous studies have shown that partially slotted scintillators offer a good compromise between cost, energy resolution and spatial resolution. In this work, the performance of two sets of CsI(Tl) and CsI(Na) partially slotted crystals is compared. Initial results show that CsI(Tl) scintillators are more suitable for gamma-ray detection, since their performance in terms of sensitivity, spatial and energy resolution is superior than that of CsI(Na)

CsI and some new photocathodes

International Nuclear Information System (INIS)

Anderson, D.F.; Kwan, S.; Peskov, V.

1993-06-01

A discussion of the possible sources of discrepancies in the measurements of the quantum efficiency of CsI photocathodes is presented. We propose that the major causes for disagreements in QE are due to the QE dependence on the current density extracted from the photocathode, on the electric field, and on the temperature of the photocathode. Preliminary results on TMAE enhanced GaAs and Si, plus TMAE protected CsTe and SbCs photocathodes, operated in gas, are also presented

137Cs distribution in guava trees

International Nuclear Information System (INIS)

Mosquera, B.; Veiga, R.; Mangia, L.; Carvalho, C.; Estellita, L.; Uzeda, D.; Facure, A.; Violini, B.; Anjos, R.M.

2004-01-01

This paper presents results of 137 Cs concentration measured from a guava tree cultivated after the first decontamination work of one of the sites where the worst Brazilian radiological accident occurred. The present work aims to verify how the 137 Cs is transported and distributed along the tropical trees. Bi-dimensional analyses of the radial distribution of 137 Cs in the main trunk are also presented. Neither symmetrical nor homogeneous behaviors of the specific activity distribution in the tree rings were observed. (author)

Coordination polyhedra CsCln in crystals

International Nuclear Information System (INIS)

Serezhkin, V.N.; Serezhkina, L.B.

1999-01-01

Characteristics of the Voronoi-Dirichlet polyhedrons are estimated for 133 crystallographic cesium atoms in chlorides Cs x M y Cl z (M=Cd, Sc, V, Nb, Mo, W, Ru, Re, etc.). It is found that cesium atoms have coordination numbers 6,8,9,10, 11 and 12 as regards the chlorine atoms. The results of cesium atom coordination sphere examination by the crossing spheres method are presented. Metal-metal interactions (including Cs-Cs) in the structure of certain chlorides are revealed

Fractionation of 137Cs and Pu in natural peatland

International Nuclear Information System (INIS)

Mihalík, Ján; Bartusková, Miluše; Hölgye, Zoltán; Ježková, Tereza; Henych, Ondřej

2014-01-01

High Cs-137 concentrations in plants growing on peatland inspired us to investigate the quantity of its bioavailable fraction in natural peat. Our investigation aims to: a) estimate the quantity of bioavailable Cs-137 and Pu present in peat, b) verify the similarity of Cs-137 and K-40 behaviours, and c) perform a quantification of Cs-137 and Pu transfer from peat to plants. We analysed the vertical distribution of Cs-137 and Pu isotopes in the peat and their concentrations in plants growing on these places. Bioavailability of radionuclides was investigated by sequential extraction. Sequential analyses revealed that it was the upper layer which contained the majority of Cs-137 in an available form while deeper layers retained Cs-137 in immobile fractions. We can conclude that 18% of all Cs-137 in the peat is still bioavailable. Despite of the low quantity of bioavailable fraction of Cs-137 its transfer factor reached extremely high values. In the case of Pu, 64% of its total amount was associated with fulvic/humic acids which resulted in the high transfer factor from peat to plants. 27 years after the Chernobyl nuclear accident, the significant part of radionuclides deposited in peatland is still bioavailable. - Highlights: • Decrease of exchangeable 137 Cs and its increase in residual fraction with depth. • High 137 Cs transfer factor contrary to its low quantity in bioavailable fractions. • Fulvic/humic acids are a more effective carrier for Pu than for Cs

Neutron Star Science with the NuSTAR

Energy Technology Data Exchange (ETDEWEB)

Vogel, J. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2015-10-16

The Nuclear Spectroscopic Telescope Array (NuSTAR), launched in June 2012, helped scientists obtain for the first time a sensitive high-­energy X-­ray map of the sky with extraordinary resolution. This pioneering telescope has aided in the understanding of how stars explode and neutron stars are born. LLNL is a founding member of the NuSTAR project, with key personnel on its optics and science team. We used NuSTAR to observe and analyze the observations of different neutron star classes identified in the last decade that are still poorly understood. These studies not only help to comprehend newly discovered astrophysical phenomena and emission processes for members of the neutron star family, but also expand the utility of such observations for addressing broader questions in astrophysics and other physics disciplines. For example, neutron stars provide an excellent laboratory to study exotic and extreme phenomena, such as the equation of state of the densest matter known, the behavior of matter in extreme magnetic fields, and the effects of general relativity. At the same time, knowing their accurate populations has profound implications for understanding the life cycle of massive stars, star collapse, and overall galactic evolution.

{sup 137}Cs in northern Adriatic sediments

Energy Technology Data Exchange (ETDEWEB)

Barisic, D; Lulic, S; Vdovic, N; Vertacnik, A [Center for Marine Research - Department Zagreb, ' Ruder Boskovic' Institute, Zagreb (Croatia); Juracic, M [Department of Geology, Faculty of Natural Sciences, University of Zagreb, Zagreb (Croatia)

1996-01-01

The activity of {sup 137}Cs in shallow northern Adriatic sediments was obtained on the basis of measurement results from 25 sediment box cores, sampled during the Adriatic Scientific COoperation Program (ASCOP) 16 cruise in the summer 1990. {sup 137}Cs was determined in surface sediments (0-3 cm) and 12-15 cm-deep sediment. It was found that the lowest caesium concentrations correspond to sands, which are spread along the Croatian coast. Parallel to the Italian coast, {sup 137}Cs concentrations in pelites are the highest. It seems that the influence of Po River is significant for {sup 137}Cs activities in recent marine sediments along Italian coast south of Po River delta. Significantly higher {sup 137}Cs activities in 0-3 cm sediment layer can be attributed to the deposition caused by Chernobyl accident. (author)

Transfer of 137Cs to wild vegetables

International Nuclear Information System (INIS)

Ito, Nobuhiko; Natsuhori, Masahiro; Mezawa, Akane; Kawakami, Akira

1998-01-01

For the evaluation of internal radiation dose, it is needed to estimate the amount of radionuclide incorporated to human body using a simulation model. 137 Cesium (Cs) is easily transferred associating with food intake as well as potassium and so, Cs is an important nuclide for evaluation of internal radiation. 137 Cs concentrations in wild vegetables are higher than those of cultured vegetables and milk. Therefore, the transfer coefficients of 137 Cs from soil to wild vegetables were estimated in this study. Wild vegetables and soils of their farms were collected in the Hakkoda Mountain range of Aomori Prefecture. The levels of 137 Cs in wild vegetables were 0.42-18.35 (Bq/kg), whereas those in cabbage and spinach were 0.08 and 0.01 (Bq/kg), respectively, indicating that the Cs level is dozens to several hundreds times higher in wild vegetables than cultured ones. And the transfer coefficient was estimated as 0.003-0.94 for the former and 0.001-0.8 for the latter. On the other hand, 1 37 Cs levels of the soils on which wild vegetables grew was 28.0 Bq/kg and it was 3.9 Bq/kg for the farm soil. Furthermore, the effects of water content and pH of the soil on the transfer coefficient were studied. (M.N.)

Imbedded Nanocrystals of CsPbBr3 in Cs4 PbBr6 : Kinetics, Enhanced Oscillator Strength, and Application in Light-Emitting Diodes.

Science.gov (United States)

Xu, Junwei; Huang, Wenxiao; Li, Peiyun; Onken, Drew R; Dun, Chaochao; Guo, Yang; Ucer, Kamil B; Lu, Chang; Wang, Hongzhi; Geyer, Scott M; Williams, Richard T; Carroll, David L

2017-11-01

Solution-grown films of CsPbBr 3 nanocrystals imbedded in Cs 4 PbBr 6 are incorporated as the recombination layer in light-emitting diode (LED) structures. The kinetics at high carrier density of pure (extended) CsPbBr 3 and the nanoinclusion composite are measured and analyzed, indicating second-order kinetics in extended and mainly first-order kinetics in the confined CsPbBr 3 , respectively. Analysis of absorption strength of this all-perovskite, all-inorganic imbedded nanocrystal composite relative to pure CsPbBr 3 indicates enhanced oscillator strength consistent with earlier published attribution of the sub-nanosecond exciton radiative lifetime in nanoprecipitates of CsPbBr 3 in melt-grown CsBr host crystals and CsPbBr 3 evaporated films. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

O stars and Wolf-Rayet stars

International Nuclear Information System (INIS)

Conti, P.S.; Underhill, A.B.; Jordan, S.; Thomas, R.

1988-01-01

Basic information is given about O and Wolf-Rayet stars indicating how these stars are defined and what their chief observable properties are. Part 2 of the volume discussed four related themes pertaining to the hottest and most luminous stars. Presented are: an observational overview of the spectroscopic classification and extrinsic properties of O and Wolf-Rayet stars; the intrinsic parameters of luminosity, effective temperature, mass, and composition of the stars, and a discussion of their viability; stellar wind properties; and the related issues concerning the efforts of stellar radiation and wind on the immediate interstellar environment are presented

O stars and Wolf-Rayet stars

Science.gov (United States)

Conti, Peter S.; Underhill, Anne B.; Jordan, Stuart (Editor); Thomas, Richard (Editor)

1988-01-01

Basic information is given about O and Wolf-Rayet stars indicating how these stars are defined and what their chief observable properties are. Part 2 of the volume discussed four related themes pertaining to the hottest and most luminous stars. Presented are: an observational overview of the spectroscopic classification and extrinsic properties of O and Wolf-Rayet stars; the intrinsic parameters of luminosity, effective temperature, mass, and composition of the stars, and a discussion of their viability; stellar wind properties; and the related issues concerning the efforts of stellar radiation and wind on the immediate interstellar environment are presented.

Enthalpy-increment measurements for CsI(s) and Cs2CrO4(s) by high-temperature Calvet calorimetry

International Nuclear Information System (INIS)

Venugopal, V.; Agarwal, R.; Roy, K.N.; Prasad, R.; Sood, D.D.

1987-01-01

Molar thermodynamic properties of CsI(s) and Cs 2 Cr O 4 (s) have been evaluated by enthalpy-increment measurements, using a Calvet high-temperature calorimeter. Least squares analyses were performed on the enthalpy increment results. Data is presented in tabular form for the dependence of enthalpy increments on temperature, in the range 333 to 822 K, for both caesium compounds, along with the thermal properties of the compounds. Good agreement is found between the present data and previously reported results on reduced enthalpy increments of CsI(s) and Cs 2 CrO 4 (s). (U.K.)

A robust star identification algorithm with star shortlisting

Science.gov (United States)

Mehta, Deval Samirbhai; Chen, Shoushun; Low, Kay Soon

2018-05-01

A star tracker provides the most accurate attitude solution in terms of arc seconds compared to the other existing attitude sensors. When no prior attitude information is available, it operates in "Lost-In-Space (LIS)" mode. Star pattern recognition, also known as star identification algorithm, forms the most crucial part of a star tracker in the LIS mode. Recognition reliability and speed are the two most important parameters of a star pattern recognition technique. In this paper, a novel star identification algorithm with star ID shortlisting is proposed. Firstly, the star IDs are shortlisted based on worst-case patch mismatch, and later stars are identified in the image by an initial match confirmed with a running sequential angular match technique. The proposed idea is tested on 16,200 simulated star images having magnitude uncertainty, noise stars, positional deviation, and varying size of the field of view. The proposed idea is also benchmarked with the state-of-the-art star pattern recognition techniques. Finally, the real-time performance of the proposed technique is tested on the 3104 real star images captured by a star tracker SST-20S currently mounted on a satellite. The proposed technique can achieve an identification accuracy of 98% and takes only 8.2 ms for identification on real images. Simulation and real-time results depict that the proposed technique is highly robust and achieves a high speed of identification suitable for actual space applications.

Star-Branched Polymers (Star Polymers)

KAUST Repository

Hirao, Akira

2015-09-01

The synthesis of well-defined regular and asymmetric mixed arm (hereinafter miktoarm) star-branched polymers by the living anionic polymerization is reviewed in this chapter. In particular, much attention is being devoted to the synthetic development of miktoarm star polymers since 2000. At the present time, the almost all types of multiarmed and multicomponent miktoarm star polymers have become feasible by using recently developed iterative strategy. For example, the following well-defined stars have been successfully synthesized: 3-arm ABC, 4-arm ABCD, 5-arm ABCDE, 6-arm ABCDEF, 7-arm ABCDEFG, 6-arm ABC, 9-arm ABC, 12-arm ABC, 13-arm ABCD, 9-arm AB, 17-arm AB, 33-arm AB, 7-arm ABC, 15-arm ABCD, and 31-arm ABCDE miktoarm star polymers, most of which are quite new and difficult to synthesize by the end of the 1990s. Several new specialty functional star polymers composed of vinyl polymer segments and rigid rodlike poly(acetylene) arms, helical polypeptide, or helical poly(hexyl isocyanate) arms are introduced.

Uptake and release of {sup 134} Cs and {sup 137} Cs and iTs relation to {sup 40} K concentration in rats

Energy Technology Data Exchange (ETDEWEB)

Essa, M W.A.; Hussein, H H.M.; Abdelfattah, A T; Abdelbaky, W M [Nuclear research Center, Atomic Energy Authority, Cairo (Egypt)

1997-12-31

Studies were performed to examine the effect of a accumulation of {sup 134} Cs and Cs-137 on the concentration of K-40 in white rats. Five male and five female rats were fed with normal diet for four weeks. After that, the ten rats were fed with macaroni contaminated with Cs-134 (116 Bq/kg) and Cs-137 (318 Bq/kg) besides the normal diet. Animal whole body counting was done once weekly for four months using HPGe and multichannel analyzer. The results should that the uptake of cesium increases until saturation was reached after about one month to values 60,65 Bq/kg for Cs-134, and 200,240 Bq/kg for Cs-137. Results show a decrease in k-40 concentration due to the replacement of potassium ions by cesium ions in the cell. After saturation, feeding with radioactive diet was replaced by normal diet. A release of Cs-134 and Cs-137 was noticed with increase of K-40 concentration. 6 figs., 2 tabs.

SEPARATION OF CsCl FROM LiCl-CsCl MOLTEN SALT BY COLD FINGER MELT CRYSTALLIZATION

Directory of Open Access Journals (Sweden)

JOSHUA R. VERSEY

2014-06-01

Full Text Available This study provides a fundamental understanding of a cold finger melt crystallization technique by exploring the heat and mass transfer processes of cold finger separation. A series of experiments were performed using a simplified LiCl-CsCl system by varying initial CsCl concentrations (1, 3, 5, and 7.5 wt%, cold finger cooling rates (7.4, 9.8, 12.3, and 14.9 L/min, and separation times (5, 10, 15, and 30 min. Results showed a potential recycling rate of 0.36 g/min with a purity of 0.33 wt% CsCl in LiCl. A CsCl concentrated drip formation was found to decrease crystal purity especially for smaller crystal formations. Dimensionless heat and mass transfer correlations showed that separation production is primarily influenced by convective transfer controlled by cooling gas flow rate, where correlations are more accurate for slower cooling gas flow rates.

Solution-Grown CsPbBr3 /Cs4 PbBr6 Perovskite Nanocomposites: Toward Temperature-Insensitive Optical Gain.

Science.gov (United States)

Wang, Yue; Yu, Dejian; Wang, Zeng; Li, Xiaoming; Chen, Xiaoxuan; Nalla, Venkatram; Zeng, Haibo; Sun, Handong

2017-09-01

With regards to developing miniaturized coherent light sources, the temperature-insensitivity in gain spectrum and threshold is highly desirable. Quantum dots (QDs) are predicted to possess a temperature-insensitive threshold by virtue of the separated electronic states; however, it is never observed in colloidal QDs due to the poor thermal stability. Besides, for the classical II-VI QDs, the gain profile generally redshifts with increasing temperature, plaguing the device chromaticity. Herein, this paper addresses the above two issues simultaneously by embedding ligands-free CsPbBr 3 nanocrystals in a wider band gap Cs 4 PbBr 6 matrix by solution-phase synthesis. The unique electronic structures of CsPbBr 3 nanocrystals enable temperature-insensitive gain spectrum while the lack of ligands and protection from Cs 4 PbBr 6 matrix ensure the thermal stability and high temperature operation. Specifically, a color drift-free stimulated emission irrespective of temperature change (20-150 °C) upon two-photon pumping is presented and the characteristic temperature is determined to be as high as ≈260 K. The superior gain properties of the CsPbBr 3 /Cs 4 PbBr 6 perovskite nanocomposites are directly validated by a vertical cavity surface emitting laser operating at temperature as high as 100 °C. The results shed light on manipulating optical gain from the advantageous CsPbBr 3 nanocrystals and represent a significant step toward the temperature-insensitive frequency-upconverted lasers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cs-137 migration in soil near NPPs

International Nuclear Information System (INIS)

Silant'ev, A.N.; Shkuratova, I.G.; Khatskevich, R.N.

1984-01-01

A convective-diffusion model has been employed for describing Cs-137 migration in soil. The migration parameters were determined by comparing the calculated vertical distribution profiles with the experimental ones. The migration parameters dependence on the soil state has been studied. Cs-137 penetration rate was found to be function of the soil type, surface state, soil wetness and orography. The obtained values are presented. A method is suggested for revealing the soil surface contamination by Cs-137 produced during NPP operation with distinguishing it from the global contamination background. For this purpose Cs-137 content in the upper 5 mm soil layer is estimated [ru

Is 137Cs Dating Becoming Obsolete in North America?

Science.gov (United States)

Drexler, J. Z.; Fuller, C.; Salas, A.

2016-12-01

Dating of wetland sediments and peat is routinely carried out using 137Cs and 210Pb analysis. Unlike 210Pb, 137Cs is an anthropogenic radionuclide with a history of fallout from nuclear weapons testing. 137Cs is used as a single time marker; its peak is coincident with the height of atmospheric nuclear testing in 1963/4. During its use in the 1970s-90s, 137Cs peaks were usually highly distinct in wetland sediments (e.g., see 137Cs peaks from Louisiana marshes in Feijtel et al., 1988). This enabled its use as a check for dates assigned to a profile by 210Pb and other methods. However, recently, the efficacy of 137Cs dating in North America has deteriorated. In this presentation, we will provide specific examples of 137Cs as well as 210Pb dating in wetland sediments/peats we collected between 2005 and 2015 in Maine, California, Virginia, North Carolina, South Carolina, and Washington. Two main reasons exist for this decline. First, 137Cs activities in our recent cores are 30-40 % of the original activities in 1963/4 due to decay of the original 137Cs in situ (half-life = 30.17 years) and no major new sources. This manifests in lower signal to noise ratio, with some peaks barely recognizable above the noise. Second, 137Cs peaks are much less distinct due to 137Cs migration through time independent of substrate (or sediment) particles. Migration of peaks has resulted in estimated accretion rates being systematically lower or higher than those derived from 210Pb dating. These issues with 137Cs dating have important implications because 137Cs is used with 210Pb dating or even alone to determine rates of recent wetland carbon accumulation. Such rates are required to enter wetland restoration projects into carbon markets and to document IPCC mandated reductions in carbon pollution. Our analysis shows that, although dating by 137Cs alone has always been highly tenuous, now it is especially contraindicated and should be disallowed for the purposes of carbon accounting.

An optical microscopy study of the swelling of wet-spun films of CsDNA as a function of hydration and CsCl concentration

Science.gov (United States)

Schwenker, Megan; Marlowe, Robert; Lee, Scott; Rupprecht, Allan

2005-03-01

Highly oriented, wet-spun films of DNA expand in the direction perpendicular to the helical axis as the hydration of the film is increased. CsDNA films with a high CsCl content show an unexpected shrinkage at a relative humidity of 92%. Our most recent experiments have been to measure the perpendicular dimension of CsDNA as a function of both hydration and concentration of CsCl. Our preliminary results show that no shrinkage is observed at low contents of CsCl, showing that the CsCl plays an integral role in the shrinkage phenomenon.

137Cs in the western South Pacific Ocean

International Nuclear Information System (INIS)

Yamada, Masatoshi; Wang Zhongliang

2007-01-01

The 137 Cs activities were determined for seawater samples from the East Caroline, Coral Sea, New Hebrides, South Fiji and Tasman Sea (two stations) Basins of the western South Pacific Ocean by γ spectrometry using a low background Ge detector. The 137 Cs activities ranged from 1.4 to 2.3 Bq m -3 over the depth interval 0-250 m and decreased exponentially from the subsurface to 1000 m depth. The distribution profiles of 137 Cs activity at these six western South Pacific Ocean stations did not differ from each other significantly. There was a remarkable difference for the vertical profiles of 137 Cs activity between the East Caroline Basin station in this study and the GEOSECS (Geochemical Ocean Sections Study) station at the same latitude in the Equatorial Pacific Ocean; the 137 Cs inventory over the depth interval 100-1000 m increased from 400 ± 30 Bq m -2 to 560 ± 30 Bq m -2 during the period from 1973 to 1992. The total 137 Cs inventories in the western South Pacific Ocean ranged from 850 ± 70 Bq m -2 in the Coral Sea Basin to 1270 ± 90 Bq m -2 in the South Fiji Basin. Higher 137 Cs inventories were observed at middle latitude stations in the subtropical gyre than at low latitude stations. The 137 Cs inventories were 1.9-4.5 times (2.9 ± 0.7 on average) and 1.7-4.3 times (3.1 ± 0.7 on average) higher than that of the expected deposition density of atmospheric global fallout at the same latitude and that of the estimated 137 Cs deposition density in 10 o latitude by 10 deg. longitude grid data obtained by Aoyama et al. [Aoyama M, Hirose K, Igarashi Y. Re-construction and updating our understanding on the global weapons tests 137 Cs fallout. J Environ Monit 2006;8:431-438], respectively. The possible processes for higher 137 Cs inventories in the western South Pacific Ocean than that of the expected deposition density of atmospheric global fallout may be attributable to the inter-hemisphere dispersion of the atmospheric nuclear weapons testing 137 Cs from

Statistical investigation of flare stars. III. Flare stars in the general galactic star field

International Nuclear Information System (INIS)

Mirzoyan, L.V.; Ambaryan, V.V.; Garibdzhanyan, A.T.; Mirzoyan, A.L.

1989-01-01

Some questions relating to the existence of a large number of flare stars in the general star field of the Galaxy are discussed. It is shown that only a small proportion of them can be found by photographic observations, and the fraction of field flare stars among such stars found in the regions of star clusters and associations does not exceed 10%. The ratio of the numbers of flare stars of the foreground and the background for a particular system depends on its distance, reaching zero at a distance of about 500 pc. The spatial density of flare stars in the Pleiades is at least two orders of magnitude greater than in the general galactic field. A lower limit for the number of flare stars in the Galaxy is estimated at 4.2 ·10 9 , and the number of nonflare red dwarfs at 2.1·10 10 . There are grounds for believing that they were all formed in star clusters and associations

Neutron star/red giant encounters in globular clusters

International Nuclear Information System (INIS)

Bailyn, C.D.

1988-01-01

The author presents a simple expression for the amount by which xsub(crit) is diminished as a star evolves xsub(crit) Rsub(crit)/R*, where Rsub(crit) is the maximum distance of closest approach between two stars for which the tidal energy is sufficient to bind the system, and R* is the radius of the star on which tides are being raised. Also it is concluded that tidal capture of giants by neutron stars resulting in binary systems is unlikely in globular clusters. However, collisions between neutron stars and red giants, or an alternative process involving tidal capture of a main-sequence star into an initially detached binary system, may result either in rapidly rotating neutron stars or in white dwarf/neutron star binaries. (author)

Tidal Distortion of the Envelope of an AGB Star IRS 3 near Sgr A{sup *}

Energy Technology Data Exchange (ETDEWEB)

Yusef-Zadeh, F.; Royster, M. J.; Roberts, D. A. [Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States); Wardle, M. [Department of Physics and Astronomy and Research Center for Astronomy, Astrophysics and Astrophotonics, Macquarie University, Sydney NSW 2109 (Australia); Cotton, W.; Kunneriath, D. [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Schödel, R. [Instituto de Astfisica de Andalucia (CSIC), Glorieta de la Astronomia S/N, E-18008 Granada (Spain)

2017-03-01

We present radio and millimeter continuum observations of the Galactic center taken with the Very Large Array (VLA) and ALMA at 44 and 226 GHz, respectively. We detect radio and millimeter emission from IRS 3, lying ∼4.″5 NW of Sgr A*, with a spectrum that is consistent with the photospheric emission from an AGB star at the Galactic center. Millimeter images reveal that the envelope of IRS 3, the brightest and most extended 3.8 μ m Galactic center stellar source, consists of two semicircular dust shells facing the direction of Sgr A*. The outer circumstellar shell, at a distance of 1.6 × 10{sup 4} au, appears to break up into “fingers” of dust directed toward Sgr A*. These features coincide with molecular CS (5–4) emission and a near-IR extinction cloud distributed between IRS 3 and Sgr A*. The NE–SW asymmetric shapes of the IRS 3 shells seen at 3.8 μ m and radio are interpreted as structures that are tidally distorted by Sgr A*. Using the kinematics of CS emission and the proper motion of IRS 3, the tidally distorted outflowing material from the envelope after 5000 yr constrains the distance of IRS 3 to ∼0.7 pc in front of or ∼0.5 pc behind Sgr A*. This suggests that the mass loss by stars near Sgr A* can supply a reservoir of molecular material near Sgr A*. We also present dark features in radio continuum images coincident with the envelope of IRS 3. These dusty stars provide examples in which high-resolution radio continuum images can identify dust-enshrouded stellar sources embedded in an ionized medium.

Symbiotic stars

International Nuclear Information System (INIS)

Boyarchuk, A.A.

1975-01-01

There are some arguments that the symbiotic stars are binary, where one component is a red giant and the other component is a small hot star which is exciting a nebula. The symbiotic stars belong to the old disc population. Probably, symbiotic stars are just such an evolutionary stage for double stars as planetary nebulae for single stars. (Auth.)

Quark core stars, quark stars and strange stars

International Nuclear Information System (INIS)

Grassi, F.

1988-01-01

A recent one flavor quark matter equation of state is generalized to several flavors. It is shown that quarks undergo a first order phase transition. In addition, this equation of state depends on just one parameter in the two flavor case, two parameters in the three flavor case, and these parameters are constrained by phenomenology. This equation of state is then applied to the hadron-quark transition in neutron stars and the determination of quark star stability, the investigation of strange matter stability and possible strange star existence. 43 refs., 6 figs

Measurement of 137Cs activity in living chicken

International Nuclear Information System (INIS)

Balas, J.; Poeschl, M.

1998-01-01

The possibility of measuring the 137 Cs activity in broiler chickens in vivo was examined. The experiment was conducted with broiler chickens 7 to 22 days old (White Leghorn hybrid, race ISA VEDETTE). Three oral doses of 137 Cs (total activity 5 kBq/chicken) were administered during a day (at 8:00, 12:00 and 16:00). The radioactivity was determined by gamma spectroscopy with a stabilised Nal/Tl detector. The measurement was carried out on days 1, 2, 3, 4, 7, 8, 14 and 15 after the 137 Cs administration in vivo. The detector was put closely to the body in the area of breast muscles. The radiocesium activity concentrations in fresh daily excreta were also determined. A rapid uptake of the orally administered 137 Cs (within a few hours) as well as a rapid loss of radiocesium were observed. The dynamics and accuracy of the in vivo measurement of 137 Cs activity were comparable with the recently published results of in vitro measurement of radiocesium activity. Only the initial 137 Cs activity (during 2 days after 137 Cs application) was higher with regard to the content of contaminated feed mixture in the gastrointestinal tract

A simple preparation of calibration curve standards of 134Cs and 137Cs by serial dilution of a standard reference material

International Nuclear Information System (INIS)

Labrecque, J.J.; Rosales, P.A.

1990-01-01

Two sets of calibration standards for 134 Cs and 137 Cs were prepared by small serial dilution of a natural matrix standard reference material, IAEA-154 whey powder. The first set was intended to screen imported milk powders which were suspected to be contaminated with 134 Cs and 137 Cs. Their concentration ranged from 40 to 400 Bq/kg. The other set of calibration standards was prepared to measure the environmental levels of 137 Cs in commercial Venezuelan milk powders. Their concentration ranged from 3 to 10 Bq/kg of 137 Cs. The accuracy of these calibration curves was checked by IAEA-152 and A-14 milk powders. Their measured values were in good agreement with their certified values. Finally, it is shown that these preparation techniques using serial dilution of a standard reference material were simple, rapid, precise, accurate and cost-effective. (author) 5 refs.; 5 figs.; 3 tabs

Kinematic and spatial distributions of barium stars - are the barium stars and Am stars related?

International Nuclear Information System (INIS)

Hakkila, J.

1989-01-01

The possibility of an evolutionary link between Am stars and barium stars is considered, and an examination of previous data suggests that barium star precursors are main-sequence stars of intermediate mass, are most likely A and/or F dwarfs, and are intermediate-mass binaries with close to intermediate orbital separations. The possible role of mass transfer in the later development of Am systems is explored. Mass transfer and loss from systems with a range of masses and orbital separations may explain such statistical peculiarities of barium stars as the large dispersion in absolute magnitude, the large range of elemental abundances from star to star, and the small number of stars with large peculiar velocities. 93 refs

Seperation of CsCl from LiCl-CsCl molten salt by cold finger melt cryst allization

Energy Technology Data Exchange (ETDEWEB)

Versey, Joshua R. [Dept. of Chemical and Materials Engineering and Nuclear Engineering Program University of Idaho, Idaho (United States); Phongikaroon, Supathorn [Dept. of Mechanical and Nuclear Engineering Virginia Commonwealth University, Richmond (Korea, Republic of); Simpson, Michael F. [Dept. of Metallurgical Engineering University of Utah, Utah (Korea, Republic of)

2014-06-15

This study provides a fundamental understanding of a cold finger melt crystallization technique by exploring the heat and mass transfer processes of cold finger separation. A series of experiments were performed using a simplified LiCl-CsCl system by varying initial CsCl concentrations (1, 3, 5, and 7.5 wt%), cold finger cooling rates (7.4, 9.8, 12.3, and 14.9 L/min), and separation times (5, 10, 15, and 30 min). Results showed a potential recycling rate of 0.36 g/min with a purity of 0.33 wt% CsCl in LiCl. A CsCl concentrated drip formation was found to decrease crystal purity especially for smaller crystal formations. Dimensionless heat and mass transfer correlations showed that separation production is primarily influenced by convective transfer controlled by cooling gas flow rate, where correlations are more accurate for slower cooling gas flow rates.

Fractionation of (137)Cs and Pu in natural peatland.

Science.gov (United States)

Mihalík, Ján; Bartusková, Miluše; Hölgye, Zoltán; Ježková, Tereza; Henych, Ondřej

2014-08-01

High Cs-137 concentrations in plants growing on peatland inspired us to investigate the quantity of its bioavailable fraction in natural peat. Our investigation aims to: a) estimate the quantity of bioavailable Cs-137 and Pu present in peat, b) verify the similarity of Cs-137 and K-40 behaviours, and c) perform a quantification of Cs-137 and Pu transfer from peat to plants. We analysed the vertical distribution of Cs-137 and Pu isotopes in the peat and their concentrations in plants growing on these places. Bioavailability of radionuclides was investigated by sequential extraction. Sequential analyses revealed that it was the upper layer which contained the majority of Cs-137 in an available form while deeper layers retained Cs-137 in immobile fractions. We can conclude that 18% of all Cs-137 in the peat is still bioavailable. Despite of the low quantity of bioavailable fraction of Cs-137 its transfer factor reached extremely high values. In the case of Pu, 64% of its total amount was associated with fulvic/humic acids which resulted in the high transfer factor from peat to plants. 27 years after the Chernobyl nuclear accident, the significant part of radionuclides deposited in peatland is still bioavailable. Copyright © 2014 Elsevier Ltd. All rights reserved.

Energy- and temperature dependences of secondary electron emission of CsI- and CsBr layers doped with Cd

International Nuclear Information System (INIS)

Galij, P.V.; Tsal', N.A.

1983-01-01

The energy and temperature dependences of the secondary electron emission coefficient (SEEC) of CsI-Cd-, CsBr-Cd-, CsI-CsBr layers have been studied. The effect of bivalent cadmium impurity on the SEEC value is investigated. It is shown that implantation of small amounts of Cd 2+ impurity into the lattice of the initial monocrystals might increase the SEEC values of the layers. Temperature dependences (TD) of SEEC are measured and the possibility of comparing experimental results with the Dekker formula is analyzed. A conclusion is drawn that the Dekker model well describes the TD of SEEC of doped layers at temperatures T < or approximately 100 deg C. At elevated temperatures., along with secondary electron scattering on phonons, one should take into account their scattering on vacancies

Cs0.49NbPS6

Directory of Open Access Journals (Sweden)

Hoseop Yun

2011-01-01

Full Text Available The quaternary thiophosphate, Cs0.49NbPS6, caesium hexathioniobiophosphate(V, has been synthesized by the reactive halide flux method. The title compound is isotypic with Rb0.46TaPS6 and is made up of a bicapped trigonal–biprismatic [Nb2S12] unit and a tetrahedral [PS4] group. The [Nb2S12] units linked by the [PS4] tetrahedra form infinite chains, yielding a three-dimensional network with rather large van der Waals gaps along the c axis in which the disordered Cs+ ions reside. The electrons released by the Cs atoms are transferred to the pairwise niobium metal site and there are substantial intermetallic Nb—Nb bonding interactions. This leads to a significant decrease of the intermetallic distance in the title compound compared to that in TaPS6. The classical charge balance of the title compound may be represented as [Cs+]0.49[Nb4.51+][P5+][S2−]4[S22−].

Uptake and distribution of 137Cs and stable Cs by microorganisms isolated from mushroom substrata in the Japanese forests

International Nuclear Information System (INIS)

Kuwahara, Chikako; Fukumoto, Atsushi; Kato, Fumio; Sugiyama, Hideo

2004-01-01

The pH values of wild mushroom substrata, the influence of pH in medium on the appearance frequencies of microorganisms from mushroom substrata, and growth and Cs uptake by several microorganisms were investigated. The results showed that the pH values of 42 mushroom substrata were slightly acidic. There was no remarkable difference in the appearance frequencies of filamentous actinomycetes and planktonic bacteria at pH 5, 6 and 7, except in the samples of mushroom substrata from Mt. Fuji. The values of Cs concentration ratio (CR) for microorganisms isolated from mushroom substrata and for mushrooms were almost the same level, suggesting that those microorganisms could take up Cs in substrata and reserve Cs in their cells. (author)

Cs[FeSe{sub 2}], Cs{sub 3}[FeSe{sub 2}]{sub 2}, and Cs{sub 7}[Fe{sub 4}Se{sub 8}]. Missing links of known chalcogenido ferrate series

Energy Technology Data Exchange (ETDEWEB)

Stueble, Pirmin; Roehr, Caroline [Institut fuer Anorganische und Analytische Chemie, Universitaet Freiburg (Germany)

2017-11-17

The three cesium selenido ferrate title compounds with an Se:Fe ratio of 2:1 were synthesized from stoichiometric samples reacting elemental Cs either (A) with Fe and Se in a double-crucible setup (Cs[FeSe{sub 2}], Cs{sub 3}[FeSe{sub 2}]{sub 2}) or (B) with previously prepared FeSe{sub 2} (Cs{sub 3}[FeSe{sub 2}]{sub 2}, Cs{sub 7}[Fe{sub 4}S{sub 8}]) (T{sub max} = 800-1000 C). The pure Fe{sup III} ferrate Cs[FeSe{sub 2}] crystallizes in the Tl[FeSe{sub 2}] type [monoclinic, space group C2/m, a = 1392.95(10), b = 564.43(3), c = 737.44(6) pm, β = 119.163(5) , Z = 4, R{sub 1} = 0.0550]. It is thus not isotypic to all other alkali ferrates(III) A[FeS{sub 2}] and A[FeSe{sub 2}] containing chains of edge-sharing tetrahedra, but crystallizes in a t2 subgroup of the Immm structure of Cs[FeS{sub 2}]. The mixed-valent chain compound Cs{sub 3}[FeSe{sub 2}]{sub 2} is isotypic to its sulfido analogue [orthorhombic, space group Pnma, a = 777.88(6), b = 1151.02(6), c = 1341.61(7) pm, Z = 4, R{sub 1} = 0.0470]. In contrast to the isopunctal Na{sub 3}[FeSe{sub 2}]{sub 2} type K/Rb compounds the chains are only slightly corrugated. The monoclinic, likewise mixed-valent Fe{sup II/III} selenido ferrate Cs{sub 7}[Fe{sub 4}Se{sub 8}] [monoclinic, space group C2/c, a = 1953.79(10), b = 879.71(5), c = 1717.03(10) pm, β = 117.890(2) , Z = 4, R{sub 1} = 0.0816] is isostructural both to the cesium sulfido and tellurido compound. The structure contains oligomeric moieties of four edge sharing [FeSe{sub 4}] tetrahedra forming slightly distorted tetrahedral clusters [Fe{sub 4}Se{sub 8}]{sup 7-}, which are surrounded by a cube of 26 Cs cations. Based on a structure map, the crystal chemistry of the three title compounds is discussed together with all chain/cluster ferrates of the general series A{sub 1+x}[Fe{sup III}{sub 1-x}Fe{sup II}{sub x}Q{sub 2}] (x = 0-1; A = Na, K, Rb, Cs; Q = S, Se, Te). (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Learning Flash CS4 Professional

CERN Document Server

Shupe, Rich

2009-01-01

Learning Flash CS4 Professional offers beginners and intermediate Flash developers a unique introduction to the latest version of Adobe's powerful multimedia application. This easy-to-read book is loaded with full-color examples and hands-on tasks to help you master Flash CS4's new motion editor, integrated 3D system, and character control using the new inverse kinematics bones animation system. No previous Flash experience is necessary.

The Two Translationally Controlled Tumor Protein Genes, CsTCTP1 and CsTCTP2, Are Negative Modulators in the Cucumis sativus Defense Response to Sphaerotheca fuliginea

Directory of Open Access Journals (Sweden)

Xiangnan Meng

2018-04-01

Full Text Available Pathogen stress often significantly decreases cucumber production. However, knowledge regarding the molecular mechanism and signals of cucumber disease resistance is far from complete. Here, we report two translationally controlled tumor protein genes, CsTCTP1 and CsTCTP2, that are both negative modulators in the Cucumis sativus defense response to Sphaerotheca fuliginea. Subcellular localization analysis showed that CsTCTP1 and CsTCTP2 were both localized in the cytoplasm. Expression analysis indicated that the transcript levels of CsTCTP1 and CsTCTP2 were linked to the degree of cucumber resistance to S. fuliginea. Transient overexpression of either CsTCTP1 or CsTCTP2 in cucumber cotyledons impaired resistance to S. fuliginea, whereas silencing of either CsTCTP1 or CsTCTP2 enhanced cucumber resistance to S. fuliginea. The relationship of several defense-related genes and ABA and target of rapamycin (TOR signaling pathway-related genes to the overexpressing and silencing of CsTCTP1/CsTCTP2 in non-infested cucumber plants was investigated. The results indicated that CsTCTP1 participates in the defense response to S. fuliginea by regulating the expression of certain defense-associated genes and/or ABA signaling pathway-associated genes, and CsTCTP2 participates through regulating the expression of TOR signaling pathway-associated genes. Our findings will guide enhancing the resistance of cucumber to powdery mildew.

Coprecipitation of 137Cs and 85Sr microquantities with complex compound [M(18-crown-6)]BPH4 (M=Na+, Cs+) from neutral and alkaline solutions

International Nuclear Information System (INIS)

Konovalova, N.A.; Rumer, I.A.; Kulyukhin, S.A.

2009-01-01

The paper reports the possibility of joint separation of 137 Cs and 85 Sr from neutral and alkaline aqueous solutions by their coprecipitation with the solid phase of complex compounds [M(18-crown-6)]BPh 4 (M=Na + , Cs + ), as well as to study the coprecipitation of 137 Cs and 85 Sr with the solid phase CsBPh 4 . It is found that complex compounds [M(18-crown-6)]BPh 4 (M=Na + , Cs + ) increased the degree of 85 Sr separation from solutions virtually two- to threefold vs. CsBPh 4 . Chloride and nitrate were found to have hardly any impact on the coprecipitation of 137 Cs and 85 Sr with [M(18-crown-6)]BPh 4 (M = Na + , Cs + ). (orig.)

Mobility and plant availability of radioactive Cs in natural soil in relation to stable Cs, other alkali elements and soil fertility

International Nuclear Information System (INIS)

Varskog, P.; Steinnes, E.; Naeumann, R.

1994-01-01

The mobility and plant availability of radioactive Cs from the Chernobyl accident in natural soil-plant systems of varying fertility were studied at three sampling locations situated in subalpine areas of central Norway. The soil samples included litter, humus (0-2 cm and 2-5 cm depth), and mineral soil (8-12 cm and 20-30 cm depth), and the plant species studied were Betula nana, Empetrum hermaphroditum and Juncus trifidus. The lichen Cetraria nivalis was also sampled. The sampling took place in the middle of the growth season during the period 1987-1989. The soil and vegetation samples were analysed with respect to total radiocaesium ( 137 Cs and 134 Cs), Rb, stable Cs and exchangeable 137 Cs (in soil only), K, Ca and Mg. (Author)

Effect of nutrition peculiarities on 137Cs uptake

International Nuclear Information System (INIS)

Knizhnikov, V.A.; Marej, A.N.; Borisov, B.K.; Petukhova, Eh.V.

1980-01-01

Reasons for different 137 Cs uptake from diets of the vegetable-animal type are studied. Indexes of accumulation multiplicity for Moscow and the Byelorussian-Ukrainian wooded district are compared. 137 Cs buildup levels in the organism of the USSR and the USA population are presented. The most probable reason for peculiarities in 137 Cs uptake from various types of diet, as well as the reason for the alterations in the uptake of this radionuclide from the diet of the same type, is the non-uniformity of 137 Cs contribution of aerial and nonaerial origin

CsMYB5a and CsMYB5e from Camellia sinensis differentially regulate anthocyanin and proanthocyanidin biosynthesis.

Science.gov (United States)

Jiang, Xiaolan; Huang, Keyi; Zheng, Guangshun; Hou, Hua; Wang, Peiqiang; Jiang, Han; Zhao, Xuecheng; Li, Mingzhuo; Zhang, Shuxiang; Liu, Yajun; Gao, Liping; Zhao, Lei; Xia, Tao

2018-05-01

Tea is one of the most widely consumed nonalcoholic beverages worldwide. Polyphenols are nutritional compounds present in the leaves of tea plants. Although numerous genes are functionally characterized to encode enzymes that catalyze the formation of diverse polyphenolic metabolites, transcriptional regulation of those different pathways such as late steps of the proanthcoyanidin (PA) pathway remains unclear. In this study, using different tea transcriptome databases, we screened at least 140 R2R3-MYB transcription factors (TFs) and grouped them according to the basic function domains of the R2R3 MYB TF superfamily. Among 140 R2R3 TFs, CsMYB5a and CsMYB5e were chosen for analysis because they may be involved in PA biosynthesis regulation. CsMYB5a-overexpressing tobacco plants exhibited downregulated anthocyanin accumulation but a high polymeric PA content in the flowers. Overexpression of CsMYB5e in tobacco plants did not change the anthocyanin content but increased the dimethylaminocinnamaldehyde-stained PA content. RNA-seq and qRT-PCR analyses revealed that genes related to PA and anthocyanin biosynthesis pathways were markedly upregulated in both CsMYB5a- and CsMYB5e-overexpressing flowers. Three UGTs and four GSTs were identified as involved in PA and anthocyanin glycosylation and transportation in transgenic plants. These results provide new insights into the regulation of PA and anthocyanin biosynthesis in Camellia sinensis. Copyright © 2018 Elsevier B.V. All rights reserved.

Recovery of Cs from high level radioactive waste

International Nuclear Information System (INIS)

Kumar, Amar; Kaushik, C.P.; Raj, K.; Varshney, Lalit

2008-01-01

Separation of Cs + from HLW restricts the personal radiation exposure during the vitrification and prevents thermal deformation of conditioned waste matrix during storage because of the high calorific power of 134 Cs (13.18 W/g) and 137 Cs (0.417 W/g) which would markedly reduce the storage cost. Separation will also reduce its volatility during vitrification and extent of migration from the vitrified mass in repository. In addition 137 Cs has enormous applications as radiation sources in food preservation, sterilization of medical products, brachy therapy, blood irradiation, hygienization of sewage sludge etc. The use of 137 Cs (T 1/2 = 30 years) in place of 60 Co (T 1/2 = 5.2 years) will also reduce the shielding requirement and frequency of source replenishment which will ease the handling/transportation of radioactive source

Bacterial CS2 Hydrolases from Acidithiobacillus thiooxidans Strains Are Homologous to the Archaeal Catenane CS2 Hydrolase

NARCIS (Netherlands)

Smeulders, M.J.; Pol, A. van der; Venselaar, H.; Barends, T.R.; Hermans, J.; Jetten, M.S.M.; Camp, H.J.M. op den

2013-01-01

Carbon disulfide (CS2) and carbonyl sulfide (COS) are important in the global sulfur cycle, and CS2 is used as a solvent in the viscose industry. These compounds can be converted by sulfur-oxidizing bacteria, such as Acidithiobacillus thiooxidans species, to carbon dioxide (CO2) and hydrogen sulfide

Early stages of Cs adsorption mechanism for GaAs nanowire surface

Science.gov (United States)

Diao, Yu; Liu, Lei; Xia, Sihao; Feng, Shu

2018-03-01

In this study, the adsorption mechanism of Cs adatoms on the (100) surface of GaAs nanowire with [0001] growth direction is investigated utilizing first principles method based on density function theory. The adsorption energy, work function, atomic structure and electronic property of clean surface and Cs-covered surfaces with different coverage are discussed. Results show that when only one Cs is adsorbed on the surface, the most favorable adsorption site is BGa-As. With increasing Cs coverage, work function gradually decreases and gets its minimum at 0.75 ML, then rises slightly when Cs coverage comes to 1 ML, indicating the existence of 'Cs-kill' phenomenon. According to further analysis, Cs activation process can effectively reduce the work function due to the formation of a downward band bending region and surface dipole moment directing from Cs adatom to the surface. As Cs coverage increases, the conduction band minimum and valence band maximum both shift towards lower energy side, contributed by the orbital hybridization between Cs-5s, Cs-5p states and Ga-4p, As-4s, As-4p states near Fermi level. The theoretical calculations and analysis in this study can improve the Cs activation technology for negative electron affinity optoelectronic devices based on GaAs nanowires, and also provide a reference for the further Cs/O or Cs/NF3 activation process.

Radioecological studies of 137Cs in limnological ecosystems. 137Cs concentrations in water, sediment and fishes at the pond in Saitama prefecture, Japan

International Nuclear Information System (INIS)

Miyake, Sadaaki; Motegi, Misako; Oosawa, Takashi; Nakazawa, Kiyoaki; Izumo, Yoshiro

1998-01-01

The concentrations of 137 Cs in water, sediment and fishes at the pond in Saitama prefecture were determined in order to elucidate the radioecology of 137 Cs in limnological ecosystems. 137 Cs concentration in water was 0.31±0.002 mBq/l (mean±standard error), and so indicated about 3 times higher than that (0.10 mBq/l) for the river in our previous report. 137 Cs concentrations in sediment, carp, Cyprinus carpio, crucian carp, Carassius auratus cuvieri, and Hakuren, Hypophthalmichthys molitrix, were about 20000, 1200, 2400 and 3100 times higher than that of the water, respectively. These concentrations were higher than those of each sample for the river in our previous report. It was so suggested that 137 Cs tended to be accumulated in these samples at the pond more than the nuclide in the river. Moreover, concentration ratios, concentration of 137 Cs in sediment, crucian carp and Hakuren to that of the water, were about 30, 2 and 3 times higher than these of 40 K, respectively, except for carp of which 137 Cs and 40 K concentration ratios were almost same. These results showed difference in accumulation mechanism between 137 Cs and 40 K in these samples, as well as 137 Cs transfer mechanism in the limnological ecosystems in part. (author)

Long-term behaviours of 137Cs in simulated crop fields

International Nuclear Information System (INIS)

Lim, K. M.; Choi, Y. H.; Park, H. K.; Park, D. W.; Lee, W. Y.

1999-01-01

In order to understand the long-term behaviour of 137 Cs in crop fields, root uptake and underground distribution of 137 Cs were investigated through a greenhouse experiment where 137 Cs was mixed with topsoil in culture boxes and rice, soybean and Chinese cabbage were grown for 4 years. Soil-to-plant transfer factors of 137 Cs for hulled rice, rice straw, soybean seed and Chinese cabbage reduced by factors of 3-10 depending on crops, and leaching of 137 Cs from the rice culture box decreased by a factor of about 7, in 3 years. The 137 Cs transfer factor for soybean seed were several times higher than that for hulled rice. The amount of 137 Cs leaching during the growing season of rice was as low as 0.025% of applied activity even in the 1st year. The uniformity of 137 Cs distribution in topsoil tended to improve year by year. The present results may be utilized as basic information for the environmental impact assessment and the counter-measure decision when crop fields are contaminated with 137 Cs

Pre-assessment of dose rates of 134Cs, 137Cs, and 60Co for marine biota from discharge of Haiyang Nuclear Power Plant, China

International Nuclear Information System (INIS)

Li, Jingjing; Liu, Senlin; Zhang, Yongxing; Chen, Ling; Yan, Yuan; Cheng, Weiya; Lou, Hailin; Zhang, Yongbao

2015-01-01

Haiyang Nuclear Power Plant to be built in China was selected as a case for the dose pre-assessment for marine biota in this study. The concentrations of Cs and Co in organisms (turbot, yellow croaker, swimming crab, abalone, sea cucumber, and sea lettuce), seawater, and bottom sediment sampled on-site were measured by neutron activation analysis, and the site-specific transfer parameters (concentration ratios and distribution coefficients) of Cs and Co were calculated. 134 Cs, 137 Cs, and 60 Co activity concentrations in the organisms and the sediment at the site were calculated with the site-specific transfer parameters and the anticipated activity concentrations in the liquid effluent of the nuclear power plant. The ERICA tool was used to estimate the dose rates of 134 Cs, 137 Cs, and 60 Co to the selected organisms based on the biological models developed. The total dose rates of 134 Cs, 137 Cs, and 60 Co to the six organisms were all <0.001 μGy h −1 . - Highlights: • Pre-assessment for biota dose rates from Haiyang Nuclear Power Plant was made. • The site-specific transfer parameters were obtained by neutron activation analysis. • The dose rates of 134 Cs, 137 Cs, and 60 Co to the organisms were <0.001 μGy h −1

Radioecological studies of {sup 137}Cs in limnological ecosystems. Biochemical states of {sup 137}Cs accumulated in killifish (Medaka, Oryzias latipes) meat

Energy Technology Data Exchange (ETDEWEB)

Miyake, Sadaaki; Motegi, Misako; Oosawa, Takashi; Nakazawa, Kiyoaki [Saitama Institute of Public Health, Urawa (Japan); Izumo, Yoshiro; Nakamura, Fumio

1997-07-01

Biochemical states of {sup 137}Cs accumulated in killifish`s (Medaka, Oryzias latipes) meat were investigated in order to elucidate the accumulation mechanism of the radionuclide in goldfish, Carassius auratus auratus, examined in our preceding report. Most of {sup 137}Cs radioactivity in the killifish`s raw meat accumulated this radionuclide in the radioactive freshwater, were found in the non-protein nitrogenous compound (NPNC) fraction (>92%), also in the killifish`s control raw meat mixed with {sup 137}Cs, the difference between both meat samples was not clear. As the results of gel filtration profiles on Sephadex G-25 for the NPNC fraction of these meats, each only one radioactive peak was shown, also similar to {sup 137}CsCl solution. Moreover, these peaks appeared at the same position. On the other hand, the peak positions absorbed at OD{sub 280nm} in the samples were different from those of each radioactive peak. It was so suggested that {sup 137}Cs accumulated in the killifish`s meat was shown not to be binding to protein`s composition. Furthermore, as the results on thin-layer chromatography, ion-exchange resin chromatography and reaction with {sup 137}Cs in samples and ammonium phosphomolybdate, {sup 137}Cs in the NPNC fraction of the killifish`s meat was not almost different from those of each control and {sup 137}CsCl solution. (author)

Exposure of a herbivorous fish to 134Cs and 137Cs from the riverbed following the Fukushima disaster

International Nuclear Information System (INIS)

Tsuboi, Jun-ichi; Abe, Shin-ichiro; Fujimoto, Ken; Kaeriyama, Hideki; Ambe, Daisuke; Matsuda, Keishi; Enomoto, Masahiro; Tomiya, Atsushi; Morita, Takami; Ono, Tsuneo; Yamamoto, Shoichiro; Iguchi, Kei'ichiro

2015-01-01

Ayu Plecoglossus altivelis, a herbivorous fish, is an important fishery resource and key component of the foodweb in many Japanese streams. Radionuclide contamination of this species is likely transferred to higher trophic levels, include humans, in the food chain. After the Fukushima accident in March 2011, ayu were exposed to highly contaminated silt while feeding on algae attached to the riverbed stones. To understand the route by which herbivorous fish are exposed to radionuclides, the activity concentrations of sum of 134 Cs and 137 Cs (radiocesium) were analyzed in riverbed samples (algae and silt) and in the internal organs and the muscle of ayu in five river systems in the Fukushima Prefecture between summer 2011 and autumn 2013. Although there was a positive correlation between the radiocesium activity concentrations in the muscle and the internal organs of ayu, the median activity concentration in the muscle was much lower than those in the internal organs. The activity concentrations of radiocesium in the riverbed samples and the internal organs and the muscle of ayu were correlated with contamination levels in soil samples taken from the watershed upstream of the sample sites. The results of the generalized linear mixed models suggest that the activity concentrations in both the internal organs and the muscle of ayu declined over time. Additionally, the activity concentrations in the internal organs were correlated with those in the riverbed samples that were collected around the same time as the ayu. The activity concentrations in the muscle were correlated with ayu body size. Our results suggest that ayu ingest 134 Cs and 137 Cs while grazing silt and algae from the riverbed, and a part of the 134 Cs and 137 Cs is assimilated into the muscle of the fish. - Highlights: • The radiocesium (sum of 134 Cs and 137 Cs) concentrations in a herbivorous fish were measured following the Fukushima disaster. • The muscle concentrations were correlated with

A Brightness-Referenced Star Identification Algorithm for APS Star Trackers

Science.gov (United States)

Zhang, Peng; Zhao, Qile; Liu, Jingnan; Liu, Ning

2014-01-01

Star trackers are currently the most accurate spacecraft attitude sensors. As a result, they are widely used in remote sensing satellites. Since traditional charge-coupled device (CCD)-based star trackers have a limited sensitivity range and dynamic range, the matching process for a star tracker is typically not very sensitive to star brightness. For active pixel sensor (APS) star trackers, the intensity of an imaged star is valuable information that can be used in star identification process. In this paper an improved brightness referenced star identification algorithm is presented. This algorithm utilizes the k-vector search theory and adds imaged stars' intensities to narrow the search scope and therefore increase the efficiency of the matching process. Based on different imaging conditions (slew, bright bodies, etc.) the developed matching algorithm operates in one of two identification modes: a three-star mode, and a four-star mode. If the reference bright stars (the stars brighter than three magnitude) show up, the algorithm runs the three-star mode and efficiency is further improved. The proposed method was compared with other two distinctive methods the pyramid and geometric voting methods. All three methods were tested with simulation data and actual in orbit data from the APS star tracker of ZY-3. Using a catalog composed of 1500 stars, the results show that without false stars the efficiency of this new method is 4∼5 times that of the pyramid method and 35∼37 times that of the geometric method. PMID:25299950

The concentration of 137Cs and stable Cs in zooplankton in the western North Pacific in relation to their taxonomic composition

International Nuclear Information System (INIS)

Kaeriyama, Hideki; Watabe, Teruhisa; Kusakabe, Masashi

2008-01-01

The objective of this study is to obtain information on the background level of 137 Cs in zooplankton in the waters close to Rokkasho-mura in Aomori Prefecture, Japan, where a large-scale project has been progressively promoted to establish the nuclear fuel cycle. Prior to the full-scale operation of the spent nuclear fuel reprocessing plant, zooplankton samples were collected in May and October 2005, June 2006, and June 2007 from the surface water (0-5 m depth). The samples were analyzed to determine the concentrations of 137 Cs and stable Cs in relation to taxonomic composition. The numerical abundance of the plankton varied from 253 to 1514 inds. m -3 . Taxonomic composition differed between the two sampling periods. Although copepods formed the most abundant taxonomic group during both seasons, gelatinous plankton (chaetognaths, siphonophores, appendicularians and doliolids) were more abundant in October 2005 than in June 2006 and June 2007. The concentration of 137 Cs in zooplankton varied from 11 to 24 mBq kg-WW -1 . At the same station, the 137 Cs concentration in zooplankton in October 2005 was almost twice as much as that in June 2006, although the concentration of 137 Cs in seawater did not show a difference. The concentration of stable Cs was measured for each taxonomic group: that in gelatinous zooplankton (chaetognaths) was higher than that in crustacean zooplankton (copepods, euphausiids and amphipods). These results suggest that the concentration of 137 Cs in zooplankton is affected by the occurrence of gelatinous zooplankton. (author)

Quantitative Cs-137 distributions from airborne gamma ray data

International Nuclear Information System (INIS)

Oberlercher, G.; Seiberl, W.

1997-01-01

The Chernobyl reactor accident caused in Austria Cs-137 activities up to 180 kBq/m 2 . The following paper explains how airborne NaJ-spectroscopy, originally designed for geological surveys, was used as an accurate method to obtain the ground activity of Cs-137 in certain regions of Austria. To retrieve the net count rate in a Cs-137 window it is necessary to subtract all background contributions from the peak, including the Compton continuum and the contribution of overlapping peaks. Therefore the measurement of Cs-137 with a NaJ detector system must take into account radioactive elements with gamma-ray lines near the peak energy of Cs-137 at 662 keV. In regions with higher concentrations of the natural radioactive elements uranium and thorium a peak near 600 keV is found, containing the 609 keV line of Bi-214 and the 585 keV line of TI-208. Additionally a Cs-134 line is located at 604 keV. Because of the poor energy resolution of NaJ detectors it is not possible to find a clear separation between these peaks and the Cs-137 peak. The following section describes the method that was used to obtain accurate quantified Cs-137 activity values. (author)

Pre-assessment of dose rates of (134)Cs, (137)Cs, and (60)Co for marine biota from discharge of Haiyang Nuclear Power Plant, China.

Science.gov (United States)

Li, Jingjing; Liu, Senlin; Zhang, Yongxing; Chen, Ling; Yan, Yuan; Cheng, Weiya; Lou, Hailin; Zhang, Yongbao

2015-09-01

Haiyang Nuclear Power Plant to be built in China was selected as a case for the dose pre-assessment for marine biota in this study. The concentrations of Cs and Co in organisms (turbot, yellow croaker, swimming crab, abalone, sea cucumber, and sea lettuce), seawater, and bottom sediment sampled on-site were measured by neutron activation analysis, and the site-specific transfer parameters (concentration ratios and distribution coefficients) of Cs and Co were calculated. (134)Cs, (137)Cs, and (60)Co activity concentrations in the organisms and the sediment at the site were calculated with the site-specific transfer parameters and the anticipated activity concentrations in the liquid effluent of the nuclear power plant. The ERICA tool was used to estimate the dose rates of (134)Cs, (137)Cs, and (60)Co to the selected organisms based on the biological models developed. The total dose rates of (134)Cs, (137)Cs, and (60)Co to the six organisms were all <0.001 μGy h(-1). Copyright © 2015 Elsevier Ltd. All rights reserved.

Cs-137 in Arctic foxes (Alopex lagopus) on Svalbard

International Nuclear Information System (INIS)

Gwynn, Justin P.; Fuglei, Eva; Dowdall, Mark

2007-01-01

This study presents 137 Cs muscle activity concentrations in Arctic foxes (Alopex lagopus) from Svalbard over a period of several years and discusses the transfer of 137 Cs to Arctic foxes through likely predator-prey relationships. Mean 137 Cs activity concentrations and 137 Cs T ag values (per trapping season) ranged from 0.51 ± 2.76 to 1.32 ± 2.89 Bq/kg (w.w.) and 5.1 x 10 -4 to 1.3 x 10 -3 m 2 /kg, respectively. Mean concentration ratios of 137 Cs in Arctic foxes compared to probable prey ranged from 1.0 to 7.9. On Svalbard, transfer of 137 Cs to Arctic foxes is likely to occur via both marine and terrestrial food chains. The relative contribution of marine and terrestrial food sources to the diet of Arctic foxes may vary by location and by season and may lead to either an increase or decrease in the trophic transfer of 137 Cs to Arctic foxes compared to transfer resulting from terrestrial only diets

{sup 137}Cs distribution in guava trees

Energy Technology Data Exchange (ETDEWEB)

Mosquera, B.; Veiga, R.; Mangia, L.; Carvalho, C.; Estellita, L.; Uzeda, D.; Facure, A.; Violini, B.; Anjos, R.M. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Fisica

2004-09-15

This paper presents results of {sup 137}Cs concentration measured from a guava tree cultivated after the first decontamination work of one of the sites where the worst Brazilian radiological accident occurred. The present work aims to verify how the {sup 137}Cs is transported and distributed along the tropical trees. Bi-dimensional analyses of the radial distribution of {sup 137}Cs in the main trunk are also presented. Neither symmetrical nor homogeneous behaviors of the specific activity distribution in the tree rings were observed. (author)

Long-term distribution of Cs-137 in freshwater ecosystem and the effect of bioturbation on leakage of Cs-137 from the sediments

International Nuclear Information System (INIS)

Aquilonius, K.

1995-06-01

The first aim of the project was to make a literature compilation regarding Cs-137 in freshwater systems. Secondly, in order to follow up the long-term behaviour of Cs-137 in Lake Hillesjoen, sediment and water was sampled with respect to Cs-137. Finally, an experiment was done with chironomids, with the aim to assess the impact of bioturbation on the leakage of Cs-137 from the sediment, since this is one of the factors contributing to the uncertainties in radioecological models. Some aspects of long-term distribution of Cs-137 in freshwater lakes is discussed. In lake Hillesjoen the pool of Cs-137 in sediments (225 kBq/m 2 , 1993) has gradually increased since the Chernobyl accident, and now exceeds the initial deposition (100 kBq/m 2 ). The effect of bioturbation on the leakage from the sediment to the water could not be clarified in this experiment, but is discussed. 40 refs

PARALLAXES FOR W49N AND G048.60+0.02: DISTANT STAR FORMING REGIONS IN THE PERSEUS SPIRAL ARM

Energy Technology Data Exchange (ETDEWEB)

Zhang, B.; Menten, K. M.; Brunthaler, A. [Max-Plank-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Reid, M. J.; Dame, T. M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Zheng, X. W. [Department of Astronomy, Nanjing University, Nanjing 210093 (China); Xu, Y. [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

2013-09-20

We report trigonometric parallax measurements of 22 GHz H{sub 2}O masers in two massive star-forming regions from Very Long Baseline Array observations as part of the Bar and Spiral Structure Legacy Survey. The distances of 11.11{sup +0.79}{sub -0.69} kpc to W49N (G043.16+0.01) and 10.75{sup +0.61}{sub -0.55} kpc to G048.60+0.02 locate them in a distant section of the Perseus arm near the solar circle in the first Galactic quadrant. This allows us to locate accurately the inner portion of the Perseus arm for the first time. Combining the present results with sources measured in the outer portion of the arm in the second and third quadrants yields a global pitch angle of 9.°5 ± 1.°3 for the Perseus arm. We have found almost no H{sub 2}O maser sources in the Perseus arm for 50° star formation activity.

Synthesis, thermal decomposition and sensitivity study of CsDNBF

Energy Technology Data Exchange (ETDEWEB)

Wang, Shaozong; Zhang, Tonglai; Yang, Li; Zhang, Jianguo; Sun, Yuanhua [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China)

2007-02-15

CsDNBF (cesium 7-hydroxy-4,6-dinitro-5,7-dihydrobenzofuroxanide) was synthesized from the sodium salt of DNBF and cesium nitrate. The thermal decomposition process has been investigated and the results show that the solid residues at 240 C are RCOOCs, CsNCO, RNO{sub 2} and CsNO{sub 3}. The sensitivity results demonstrate that CsDNBF has better properties than KDNBF, which has been widely used. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

Chemical information on tank supernatants, Cs adsorption from tank liquids onto Hanford sediments, and field observations of Cs migration from past tank leaks

Energy Technology Data Exchange (ETDEWEB)

Serne, R.J.; Zachara, J.M.; Burke, D.S.

1998-01-01

Borehole gamma-logging profiles beneath the SX-Tank Farm suggest that contamination from Cs-137 extends to at least a depth of 40 m (130 ft), and may extend even deeper. What is presently not known is the pathway that Cs-137 has taken to reach these depths. In this report we provide an analysis of the chemistry of tank supernates with emphasis on the REDOX waste stream disposed in SX tanks, Cs chemistry in aqueous solutions and adsorption properties onto minerals, available data on Cs adsorption onto Hanford sediments, and information on Cs migration from other Hanford tank leaks that have been studied. The data in this report was used to help guide the vadose zone transport analysis of the SX Tank Farm presented in a companion report. The goal of the vadose zone transport modelling is to attempt to explain the depth and extent of the Cs-137 plume under the SX Tank farm, specifically in the vicinity of the greatest leak, near the SX-109 Tank as inferred from the gamma logs (DOE 1996). In solution Cs is present as the monovalent cation and shows very little tendency to form aqueous complexes with inorganic or organic ligands. Cs is expected to adsorb primarily onto selective minerals that have unique adsorption sites. The small Cs{sup +} ion is accommodated on these frayed edge and interlayer sites. Adsorption within the interlayers often leads to collapse of the layers such that the Cs{sup +} ion is effectively trapped and not readily exchangeable by all other common cations. The degree of adsorption is thus only moderately dependent on the types and high concentrations of other cations in leaking tank liquors.

Chemical information on tank supernatants, Cs adsorption from tank liquids onto Hanford sediments, and field observations of Cs migration from past tank leaks

International Nuclear Information System (INIS)

Serne, R.J.; Zachara, J.M.; Burke, D.S.

1998-01-01

Borehole gamma-logging profiles beneath the SX-Tank Farm suggest that contamination from Cs-137 extends to at least a depth of 40 m (130 ft), and may extend even deeper. What is presently not known is the pathway that Cs-137 has taken to reach these depths. In this report we provide an analysis of the chemistry of tank supernates with emphasis on the REDOX waste stream disposed in SX tanks, Cs chemistry in aqueous solutions and adsorption properties onto minerals, available data on Cs adsorption onto Hanford sediments, and information on Cs migration from other Hanford tank leaks that have been studied. The data in this report was used to help guide the vadose zone transport analysis of the SX Tank Farm presented in a companion report. The goal of the vadose zone transport modelling is to attempt to explain the depth and extent of the Cs-137 plume under the SX Tank farm, specifically in the vicinity of the greatest leak, near the SX-109 Tank as inferred from the gamma logs (DOE 1996). In solution Cs is present as the monovalent cation and shows very little tendency to form aqueous complexes with inorganic or organic ligands. Cs is expected to adsorb primarily onto selective minerals that have unique adsorption sites. The small Cs + ion is accommodated on these frayed edge and interlayer sites. Adsorption within the interlayers often leads to collapse of the layers such that the Cs + ion is effectively trapped and not readily exchangeable by all other common cations. The degree of adsorption is thus only moderately dependent on the types and high concentrations of other cations in leaking tank liquors

Absorption spectra of CsNd(MoO4)2 and CsGd(MoO4)2-Nd3+ crystals in strong magnetic fields

International Nuclear Information System (INIS)

Gorban', I.S.; Kozeeva, L.P.; Slobodyanyuk, A.V.; Shevchenko, V.A.

1987-01-01

The comparison of the electronic structure of Nd 3+ in CsNd(MoO 4 ) 2 and CsGd(MoO 4 ) 2 - Nd 3+ crystals is made. It is established that in these crystals the activator centers, mainly, of the certain type with the symmetry of the local environment C 2 are formed. The absorption spectra of self-activated CsNd(MoO 4 ) 2 crystal differ from spectra of CsGd(MoO 4 ) 2 - Nd 3+ by the presence of the vibrating structure. The Stark splittings of energy levels of Nd 3+ in the investigated crystalline matrices are more sensitive to the environment effect than the Zeeman ones. The ground state of Nd 3+ ion in CsNd(MoO 4 ) 2 and CsGd(MoO 4 ) 2 molybdates is characterized by the similar values of g-factors

133Cs NMR investigation of 2D frustrated Heisenberg antiferromagnet, Cs2CuCl4

Science.gov (United States)

Vachon, M.-A.; Kundhikanjana, W.; Straub, A.; Mitrovic, V. F.; Reyes, A. P.; Kuhns, P.; Coldea, R.; Tylczynski, Z.

2006-10-01

We report 133Cs nuclear magnetic resonance (NMR) measurements on the 2D frustrated Heisenberg antiferromagnet Cs2CuCl4 down to 2 K and up to 15 T. We show that 133Cs NMR is a good probe of the magnetic degrees of freedom in this material. Cu spin degrees of freedom are sensed through a strong anisotropic hyperfine coupling. The spin excitation gap opens above the critical saturation field. The gap value was determined from the activation energy of the nuclear spin-lattice relaxation rate in a magnetic field applied parallel to the Cu chains (\\skew3\\hat{b} axis). The values of the g-factor and the saturation field are consistent with the neutron-scattering and magnetization results. The measurements of the spin spin relaxation time are exploited to show that no structural changes occur down to the lowest temperatures investigated.

Design and application of star map simulation system for star sensors

Science.gov (United States)

Wu, Feng; Shen, Weimin; Zhu, Xifang; Chen, Yuheng; Xu, Qinquan

2013-12-01

Modern star sensors are powerful to measure attitude automatically which assure a perfect performance of spacecrafts. They achieve very accurate attitudes by applying algorithms to process star maps obtained by the star camera mounted on them. Therefore, star maps play an important role in designing star cameras and developing procession algorithms. Furthermore, star maps supply significant supports to exam the performance of star sensors completely before their launch. However, it is not always convenient to supply abundant star maps by taking pictures of the sky. Thus, star map simulation with the aid of computer attracts a lot of interests by virtue of its low price and good convenience. A method to simulate star maps by programming and extending the function of the optical design program ZEMAX is proposed. The star map simulation system is established. Firstly, based on analyzing the working procedures of star sensors to measure attitudes and the basic method to design optical system by ZEMAX, the principle of simulating star sensor imaging is given out in detail. The theory about adding false stars and noises, and outputting maps is discussed and the corresponding approaches are proposed. Then, by external programming, the star map simulation program is designed and produced. Its user interference and operation are introduced. Applications of star map simulation method in evaluating optical system, star image extraction algorithm and star identification algorithm, and calibrating system errors are presented completely. It was proved that the proposed simulation method provides magnificent supports to the study on star sensors, and improves the performance of star sensors efficiently.

Initial interaction of {sup 137}Cs with soils

Energy Technology Data Exchange (ETDEWEB)

Nagasaki, S., E-mail: nagasaki@mcmaster.ca [McMaster Univ., Hamilton, Ontario (Canada); Makino, H.; Saito, T. [Univ. of Toyko, Tokyo (Japan)

2013-07-01

It is critical to understand the physicochemical behaviour of Cs in soil in order to progress the decontamination of soils which were contaminated by nuclear power plant accident and to improve the reliability of safety assessment of used nuclear fuel disposal. In this paper, the initial interactions of {sup 137}Cs with soils, which were sampled in Fukushima 38 days after Fukushima Accident, were investigated with sequential extraction method. It was found that there were fast and slow processes of fixation of {sup 137}Cs in clay minerals and that the organic substances might play an important role on kinetics of {sup 137}Cs in soils. (author)

Uptake of Cs 137 from farmland 1986-1989

International Nuclear Information System (INIS)

Holmberg, M.

1986-12-01

The basic mechanisms of the accumulation of Cs 137 in grass, corn, oleiferous plants, potatoes etc are described. It is also presented as a function of time after the deposition. Transport of Cs 137 to milk, meat and bacon is described. A prognosis of Cs 137 in food products for the coming two years is made on basis of the estimated data. (G.B.)

137Cs in man due to nuclear fallout

International Nuclear Information System (INIS)

Poulheim, K.F.

1981-01-01

137 Cs has been determined in man with the aid of a whole-body counter. It is shown that the specific 137 Cs content (as related to the potassium content in man) continuously decreased from 1965 through 1974. After a slight increase in 1975, possibly caused by a Chinese atmospheric nuclear test in June 1974, the 137 Cs content again decreased in the following years. (author)

Regular Generalized Star Star closed sets in Bitopological Spaces

OpenAIRE

K. Kannan; D. Narasimhan; K. Chandrasekhara Rao; R. Ravikumar

2011-01-01

The aim of this paper is to introduce the concepts of τ1τ2-regular generalized star star closed sets , τ1τ2-regular generalized star star open sets and study their basic properties in bitopological spaces.

The radiation chemistry of the Cs-7SB modifier used in Cs and Sr extraction

International Nuclear Information System (INIS)

Swancutt, Katy L.; Cullen, Thomas D.; Mezyk, Stephen P.; Elias, Gracy; Bauer, William F.; Peterman, Dean R.; Riddle, Catherine L.; Ball, R. Duane; Mincher, Bruce J.; Muller, James J.

2011-01-01

The compound 1-(2,2,3,3,-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol, also called Cs-7SB, is used as a solvent modifier in formulations containing calixarenes and crown ethers for cesium and/or strontium extraction from nuclear waste solutions. The compound solvates complexes of both metals and concentration decreases result in lowered extraction efficiency for both. The use of Cs-7SB in nuclear solvent extraction ensures that it will be exposed to high radiation doses, and thus its radiation chemical robustness is a matter of interest in the design of extraction systems employing it. The behavior of the compound in irradiated solution, both in the presence and absence of a nitric acid aqueous phase was investigated here using steady state and pulsed radiolysis techniques. The rate constants for the aqueous reactions of Cs-7SB with H, OH, NO 3 and NO 2 radicals are reported. UPLC-UV-MS results were used to identify major products of the radiolysis of Cs-7SB in contact with nitric acid, and revealed the production of hydroxylated nitro-derivatives. Reaction mechanisms are proposed and it is concluded that the aryl ether configuration of this molecule makes it especially susceptible to nitration in the presence of radiolytically-produced nitrous acid. Fluoride yields are also given under various conditions.

Measurement limits to 134Cs concentration in soil

International Nuclear Information System (INIS)

Ahn, J.K.; Kim, J.S.; Lee, H.M.; Kim, H.; Kim, T.H.; Park, J.N.; Kang, Y.S.; Lee, H.S.; Kim, S.J.; Park, J.Y.; Ryu, S.Y.; Kim, H.-Ch.; Kang, W.G.; Kim, S.K.

2011-01-01

We investigate the caesium concentrations in soils in mountain areas near Gori nuclear power plant in Korea, focusing on the measurement limits to the 134 Cs. In order to lower the minimum detectable amount (MDA) of activity for the 134 Cs, we have used the ammonium molybdophosphate (AMP) precipitation method to get rid of the 40 K existing in natural radioactivity, which reduces the MDA activity about 10 times smaller than those without the AMP precipitation method. The MDA results for the 134 Cs were found to be in the range between 0.015 and 0.044 Bq/kg-dry weight. In order to diminish the background, we also have measured a part of the soil samples in Yangyang, a small town in the east coast of Korea. However, it turns out that in order to detect the 134 Cs in the samples the MDA should be reduced to the level of mBq/kg-dry weight. - Highlights: → We study the caesium concentrations in soils in mountain areas near Gori NPT in Korea. → We use the AMP precipitation method to lower the minimum detectable amount (MDA) of activity for the 134 Cs. → The results of the MDA for the 134 Cs turn out to be in the range between 0.015 and 0.044. → In order to detect the 134 Cs in the samples, the MDA should be reduced to the level of mBq/kg-dry weight.

134Cs and 137Cs whole-body measurements and internal dosimetry of the population living in areas contaminated by radioactivity after the Chernobyl accident

International Nuclear Information System (INIS)

Zvonova, I.A.; Jesko, T.V.; Balonov, M.I.; Danilova, I.O.; Wallstroem, E.; Alpsten, M.; Thornberg, C.; Mattsson, S.

1995-01-01

Six western districts of the Bryansk region, Russia, were heavily contaminated with radioactive fallout after the Chernobyl NPP accident. Annually, between 1991 and 1994, inhabitants of four settlements were studied. Whole-body 134+137 Cs contents were measured in about 500 inhabitants. No correlation between Cs whole-body content and Cs soil contamination was found; Cs accumulation in a body depends greatly on natural factors such as type of soil, on social factors such as food habits including consumption of forest products, and on countermeasures to reduce internal exposure. During 1991-1994 average whole-body content of 134+137 Cs in adult inhabitants was about 3-60 kBq, corresponding to an effective dose of 0.1-2.4 mSv.y -1 . Cs whole-body content increases equally for girls and boys up to adult age. Cs content in adults does not depend significantly on age and is usually 1.2-2 times higher in men than in women. The average annual internal effective dose varies with age significantly less than 134+137 Cs whole-body content. In children (0-5 years) the mean absorbed dose is usually 1.2-1.5 times less than in adults. (author)

Room-temperature synthesis of pure perovskite-related Cs4PbBr6 nanocrystals and their ligand-mediated evolution into highly luminescent CsPbBr3 nanosheets

Science.gov (United States)

Yang, Liu; Li, Dongmei; Wang, Cong; Yao, Wei; Wang, Hao; Huang, Kaixiang

2017-07-01

Currently, all-inorganic cesium lead-halide perovskite nanocrystals have attracted enormous attentions owing to their excellent optical performances. While great efforts have been devoted to CsPbBr3 nanocrystals, the perovskite-related Cs4PbBr6 nanocrystals, which were newly reported, still remained poorly understood. Here, we reported a novel room-temperature reaction strategy to synthesize pure perovskite-related Cs4PbBr6 nanocrystals. Size of the products could be adjusted through altering the amount of ligands, simply. A mixture of two good solvents with different polarity was innovatively used as precursor solvent, being one key to the high-yield Cs4PbBr6 nanocrystals synthesis. Other two keys were Cs+ precursor concentration and surface ligands. Ingenious experiments were designed to reveal the underlying reaction mechanism. No excitonic emission was observed from the prepared Cs4PbBr6 nanocrystals in our work. We considered the green emission which was observed in other reports originated from the avoidless transformation of Cs4PbBr6 into CsPbBr3 nanocrystals. Indeed, the new-prepared Cs4PbBr6 nanocrystals could transform into CsPbBr3 nanosheets with surface ligands mediated. The new-transformed two-dimensional CsPbBr3 nanosheets could evolve into large-size nanosheets. The influences of surface ligand density on the fluorescent intensity and stability of transformed CsPbBr3 nanosheets were also explained. Notably, the photoluminescence quantum yield of the as-transformed CsPbBr3 nanosheets could reach as high as 61.6% in the form of thin film. The fast large-scale synthesis of Cs4PbBr6 nanocrystals and their ligand-mediated transformation into high-fluorescent CsPbBr3 nanosheets will be beneficial to the future optoelectronic applications. Our work provides new approaches to understand the structural evolution and light-emitting principle of perovskite nanocrystals. [Figure not available: see fulltext.

Theoretical investigation of the Cs*Hen>=3 exciplexes

International Nuclear Information System (INIS)

Zbiri, Mohamed; Daul, Claude

2005-01-01

The X 2 Σ 1/2 , A 2 Π 1/2 , B 2 Σ 1/2 , and A 2 Π 3/2 states of Cs*He n exciplexes, with n={3,...,9}, are studied using first principle density functional theory (DFT) formalism combined with the zeroth order regular approximation (ZORA). The zero points energies (ZPEs) E 0 for Cs*He n are calculated at a first step, in order to estimate the stability of the studied exciplexes. Relativistic calculations are carried out including spin-orbit effect (SO), and potential energy surfaces of Cs*He 6 are shown. The electronic distribution shapes of the studied molecules are also discussed, and their emission lines are evaluated and compared to a new discovered experimental emission spectra, which has been recently assigned, using a semi-empirical model, to Cs(AΠ 1/2 )He 7 . Our first principle calculation suggests that the discovered emission line is most probably due to a decay of Cs(AΠ 1/2 )He 6

Photon Reabsorption in Mixed CsPbCl3:CsPbI3 Perovskite Nanocrystal Films for Light-Emitting Diodes

KAUST Repository

Davis, Nathaniel J. L. K.; de la Peñ a, Francisco J.; Tabachnyk, Maxim; Richter, Johannes M.; Lamboll, Robin D.; Booker, Edward P.; Wisnivesky Rocca Rivarola, Florencia; Griffiths, James T.; Ducati, Caterina; Menke, S. Matthew; Deschler, Felix; Greenham, Neil C.

2017-01-01

is significantly reduced. We investigate samples containing mixtures of perovskite nanocrystals with different compositions and study the resulting optical and electrical interactions. We report excitation transfer from CsPbCl3 to CsPbI3 in solution and within a

Crystal structure of CsTb(PO3)4 compound

International Nuclear Information System (INIS)

Palkina, K.K.; Maksimova, S.I.; Kuznetsov, V.G.; Chibiskova, N.T.

1978-01-01

The X-ray structural study of compounds of the CsLn(PO 3 ) 4 series has been made. Found is the presence of two structural types for CsPr(PO 3 ) 4 (cubic and monoclinic modifications), one type for CsNd(PO 3 ) 4 (cubic modification) and for CsTb(PO 3 ) 4 (monoclinic modification). For the CsTb(PO 3 ) 4 monocrystal the lattice parameters are determined: a=7.032 +- 0.001; b=8.705 +- 0.001; c=9.051 +- 0.001 A; α=90 deg, β=90 deg, γ=100 deg, Z=2, V=545.68 A 3 , dsub(exp)=3.70 g/cm 3 . The structure character is presented as infinite chains of (PO 4 ) tetrahedrons, stretched along the ''C'' period. Tb and Cs atoms are rounded by 8 atoms of oxygen. Tb polyhedron are irregular octaapexes or strongly deformed tetragonal antiprisms. Tb-Tb shortest distance is 6.59 A

Modelling 137Cs uptake in plants from undisturbed soil monoliths

International Nuclear Information System (INIS)

Waegeneers, Nadia; Smolders, Erik; Merckx, Roel

2005-01-01

A model predicting 137 Cs uptake in plants was applied on data from artificially contaminated lysimeters. The lysimeter data involve three different crops (beans, ryegrass and lettuce) grown on five different soils between 3 and 5 years after contamination and where soil solution composition was monitored. The mechanistic model predicts plant uptake of 137 Cs from soil solution composition. Predicted K concentrations in the rhizosphere were up to 50-fold below that in the bulk soil solution whereas corresponding 137 Cs concentration gradients were always less pronounced. Predictions of crop 137 Cs content based on rhizosphere soil solution compositions were generally closer to observations than those based on bulk soil solution composition. The model explained 17% (beans) to 91% (lettuce) of the variation in 137 Cs activity concentrations in the plants. The model failed to predict the 137 Cs activity concentration in ryegrass where uptake of the 5-year-old 137 Cs from 3 soils was about 40-fold larger than predicted. The model generally underpredicted crop 137 Cs concentrations at soil solution K concentration below about 1.0 mM. It is concluded that 137 Cs uptake can be predicted from the soil solution composition at adequate K nutrition but that significant uncertainties remain when soil solution K is below 1 mM

A homeostatic-partly dynamic model for Cs-137 in trees

International Nuclear Information System (INIS)

Frissel, M. J.

1994-01-01

To describe the uptake of Cs-137 (hereafter only called Cs) two types of models seem most promising: the simple concentration ratio model and the homeostatic model. The first one calculates the concentration of Cs in the vegetation from the Cs concentration in the soil by applying a multiplication factor which is often called a transfer factor. There is no dynamics in the system, the transfer factor or concentration ratio is a constant, which may depend on the ecological system under study. It is often applied to annual crops. The second type of model assumes that the Cs/K ratio in the soil determines the Cs/K ratio in the vegetation. Also this model is usually static. By taking into account variations of the Cs/K ratio in the soil with time - e.g. as caused by K fertilization - it can be extended into a dynamic model. (author)

I-Love relations for incompressible stars and realistic stars

Science.gov (United States)

Chan, T. K.; Chan, AtMa P. O.; Leung, P. T.

2015-02-01

In spite of the diversity in the equations of state of nuclear matter, the recently discovered I-Love-Q relations [Yagi and Yunes, Science 341, 365 (2013), 10.1126/science.1236462], which relate the moment of inertia, tidal Love number (deformability), and the spin-induced quadrupole moment of compact stars, hold for various kinds of realistic neutron stars and quark stars. While the physical origin of such universality is still a current issue, the observation that the I-Love-Q relations of incompressible stars can well approximate those of realistic compact stars hints at a new direction to approach the problem. In this paper, by establishing recursive post-Minkowskian expansion for the moment of inertia and the tidal deformability of incompressible stars, we analytically derive the I-Love relation for incompressible stars and show that the so-obtained formula can be used to accurately predict the behavior of realistic compact stars from the Newtonian limit to the maximum mass limit.

DENSE GAS TRACERS AND STAR FORMATION LAWS IN ACTIVE GALAXIES: APEX SURVEY OF HCN J = 4 → 3, HCO{sup +} J = 4 → 3, AND CS J = 7 → 6

Energy Technology Data Exchange (ETDEWEB)

Zhang, Zhi-Yu; Gao, Yu; Zhao, Yinghe [Purple Mountain Observatory/Key Lab for Radio Astronomy, 2 West Beijing Road, Nanjing 210008 (China); Henkel, Christian; Menten, Karl M.; Güsten, Rolf [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Wang, Junzhi, E-mail: zyzhang@pmo.ac.cn [Shanghai Astronomical Observatory, 80 Nandan Road, Shanghai 200030 (China)

2014-04-01

We report HCN J = 4 → 3, HCO{sup +} J = 4 → 3, and CS J = 7 → 6 observations in 20 nearby star-forming galaxies with the Atacama Pathfinder EXperiment 12 m telescope. Combined with four HCN, three HCO{sup +}, and four CS detections from the literature, we probe the empirical link between the luminosity of molecular gas (L{sub gas}{sup ′}) and that of infrared emission (L {sub IR}), up to the highest gas densities (∼10{sup 6} cm{sup –3}) that have been probed so far. For nearby galaxies with large radii, we measure the IR luminosity within the submillimeter beam size (14''-18'') to match the molecular emission. We find linear slopes for L{sub CS} {sub J=7--6}{sup ′}-L {sub IR} and L{sub HCN} {sub J=4--3}{sup ′}-L {sub IR}, and a slightly super-linear slope for L{sub HCO{sup +}} {sub J=4--3}{sup ′}-L {sub IR}. The correlation of L{sub CS} {sub J=7--6}{sup ′}-L {sub IR} even extends over eight orders of luminosity magnitude down to Galactic dense cores, with a fit of log(L {sub IR}) =1.00(± 0.01) ×log(L{sub CS} {sub J=7--6}{sup ′}) + 4.03(± 0.04). Such linear correlations appear to hold for all densities >10{sup 4} cm{sup –3}, and indicate that star formation rate is not related to the free-fall timescale for dense molecular gas.

Search for OB stars running away from young star clusters. II. The NGC 6357 star-forming region

Science.gov (United States)

Gvaramadze, V. V.; Kniazev, A. Y.; Kroupa, P.; Oh, S.

2011-11-01

Dynamical few-body encounters in the dense cores of young massive star clusters are responsible for the loss of a significant fraction of their massive stellar content. Some of the escaping (runaway) stars move through the ambient medium supersonically and can be revealed via detection of their bow shocks (visible in the infrared, optical or radio). In this paper, which is the second of a series of papers devoted to the search for OB stars running away from young ( ≲ several Myr) Galactic clusters and OB associations, we present the results of the search for bow shocks around the star-forming region NGC 6357. Using the archival data of the Midcourse Space Experiment (MSX) satellite and the Spitzer Space Telescope, and the preliminary data release of the Wide-Field Infrared Survey Explorer (WISE), we discovered seven bow shocks, whose geometry is consistent with the possibility that they are generated by stars expelled from the young (~1-2 Myr) star clusters, Pismis 24 and AH03 J1725-34.4, associated with NGC 6357. Two of the seven bow shocks are driven by the already known OB stars, HD 319881 and [N78] 34. Follow-up spectroscopy of three other bow-shock-producing stars showed that they are massive (O-type) stars as well, while the 2MASS photometry of the remaining two stars suggests that they could be B0 V stars, provided that both are located at the same distance as NGC 6357. Detection of numerous massive stars ejected from the very young clusters is consistent with the theoretical expectation that star clusters can effectively lose massive stars at the very beginning of their dynamical evolution (long before the second mechanism for production of runaway stars, based on a supernova explosion in a massive tight binary system, begins to operate) and lends strong support to the idea that probably all field OB stars have been dynamically ejected from their birth clusters. A by-product of our search for bow shocks around NGC 6357 is the detection of three circular

Distribution of 137Cs in the American Coot (Fulica americana)

International Nuclear Information System (INIS)

Potter, C.M.; Brisbin, I.L. Jr.; McDowell, S.G.; Whicker, F.W.

1989-01-01

Caesium-137 concentrations were determined for major tissue and organ components of Americal Coots (Fulica americana) wintering on two contaminated reactor cooling reservoirs on the US Department of Energy's Savannah River Plant. Concentrations reflected the relative contamination levels of the two reservoirs. A low ratio of 137 Cs in gut contents to that in muscle indicated that the coots used in the study were established winter residents and tissue 137 Cs had probably reached equilibrium with intake. The contributions of each component to the whole body weight and total 137 Cs body burden were calculated. Skeletal muscle exhibited the highest 137 Cs concentrations and comprised 35% of the total 137 Cs body burden. Gut contents represented 17% of the total body burden. Various other organs were intermediate and bone exhibited the lowest 137 Cs concentrations. Linear regressions were determined for 137 Cs concentrations in skeletal muscle, liver, kidney, gastrointestinal (GI) tract tissue and gut contents, as functions of whole-body concentrations. (author)

Chondroitin Sulfate (CS) Lyases: Structure, Function and Application in Therapeutics.

Science.gov (United States)

Rani, Aruna; Patel, Seema; Goyal, Arun

2018-01-01

Glycosaminoglycans (GAGs) such as chondroitin sulfate (CS) are the chief natural polysaccharides which reside in biological tissues mainly in extracellular matrix. These CS along with adhesion molecules and growth factors are involved in central nervous system (CNS) development, cell progression and pathogenesis. The chondroitin lyases are the enzyme that degrade and alter the CS chains and hence modify various signalling pathways involving CS chains. These CS lyases are substrate specific, can precisely manipulate the CS polysaccharides and have various biotechnological, medical and therapeutic applications. These enzymes can be used to produce the unsaturated oligosaccharides, which have immune-modulatory, anti-inflammatory and neuroprotective properties. This review focuses on the major breakthrough of the chondroitin sulfate degrading enzymes, their structures and functioning mechanism. This also provides comprehensive information regarding production, purification, characterization of CS lyases and their major applications, both established as well as emerging ones such as neural development. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Do All O Stars Form in Star Clusters?

Science.gov (United States)

Weidner, C.; Gvaramadze, V. V.; Kroupa, P.; Pflamm-Altenburg, J.

The question whether or not massive stars can form in isolation or only in star clusters is of great importance for the theory of (massive) star formation as well as for the stellar initial mass function of whole galaxies (IGIMF-theory). While a seemingly easy question it is rather difficult to answer. Several physical processes (e.g. star-loss due to stellar dynamics or gas expulsion) and observational limitations (e.g. dust obscuration of young clusters, resolution) pose severe challenges to answer this question. In this contribution we will present the current arguments in favour and against the idea that all O stars form in clusters.

137Cs concentration in some Philippine foods

International Nuclear Information System (INIS)

dela Cruz, B.; Marzan, A.M.; Lagmay, N.; Anden, A.

1977-01-01

The current investigation being made by the Philippine Atomic Research Center on the 137 Cs content of the different foods commonly used by the Filipinos is described and preliminary results are reported. The 137 Cs content is determined radiochemically only for the edible portion of the food

Cs separation from nitric acid solutions of radioactive waste

International Nuclear Information System (INIS)

Heckmann, K.; Pieronczyk, W.; Strnad, J.; Feldmaier, F.

1989-01-01

It was the objective of this study to selectively separate active caesium (Cs-134 and Cs-137) from acid radioactive waste solutions (especially MAW and HAWC). The following 'strategy' was designed for a separation process: synthesis of reagents which are acid-resistant and selective for caesium; precipitation of Cs + and separation of the precipitates by filtration or centrifugation or precipitation of Cs + and separation of the precipitates by flotation; caesium separation by liquid-liquid extraction. As precipitating agents, sodium tetraphenylborate (kalignost) and several of its fluorine derivatives were examined. (orig./RB) [de

Export of 134 Cs and 137 Cs in the Fukushima river systems at heavy rains by Typhoon Roke in September 2011

Directory of Open Access Journals (Sweden)

S. Nagao

2013-10-01

Full Text Available At stations on the Natsui River and the Same River in Fukushima Prefecture, Japan, effects of a heavy rain event on radiocesium export were studied after Typhoon Roke during 21–22 September 2011, six months after the Fukushima Dai-ichi Nuclear Power Plant accident. Radioactivity of 134Cs and 137Cs in river waters was 0.009–0.098 Bq L−1 in normal flow conditions during July–September 2011, but it increased to 0.85 Bq L−1 in high flow conditions because of heavy rains occurring with the typhoon. The particulate fractions of 134Cs and 137Cs were 21–56% of total radiocesium in the normal flow condition, but were close to 100% after the typhoon. These results indicate that the pulse input of radiocesium associated with suspended particles from land to coastal ocean occurred because of the heavy rain event. Export flux of 134Cs and 137Cs attributable to the heavy rain accounts for 30–50% of the annual radiocesium flux from inland to coastal ocean region in 2011. Results show that rain events are one factor contributing to the transport and dispersion of radiocesium in river watersheds and coastal marine environments.

Effect of minerals on accumulation of Cs by fungus Saccaromyces cerevisiae

International Nuclear Information System (INIS)

Ohnuki, Toshihiko; Sakamoto, Fuminori; Yamasaki, Shinya; Kozai, Naofumi; Shiotsu, Hiroyuki; Utsunomiya, Satoshi; Watanabe, Naoko; Kozaki, Tamotsu

2015-01-01

The accumulation of Cs by unicellular fungus of Saccharomyces cerevisiae in the presence of minerals has been studied to elucidate the role of microorganisms in the migration of radioactive Cs in the environment. Two different types of experiments were employed: experiments using stable Cs to examine the effect of a carbon source on the accumulation of Cs, and accumulation experiments of radioactive Cs from agar medium containing 137 Cs and zeolite, vermiculite, phlogopite, smectite, mica, or illite as mineral supplements. In the former type of experiments, the Cs-accumulated cells were analyzed by scanning electron microscopy equipped with energy dispersive X-ray analysis (SEM-EDS). In the latter type, the radioactivity in the yeast cells was measured by an autoradiography technique. When a carbon source was present, higher amounts of Cs accumulated in the cells than in the resting condition without a carbon source. Analyses with SEM-EDS showed that no mineral formed on the cell surface. These results indicate that the yeast cells accumulate Cs by adsorption on the cell surface and intracellular accumulation. In the presence of minerals in the agar medium, the radioactivity in the yeast cells was in the order of mica > smectite, illite >> vermiculite, phlogopite, zeolite. This order is inversely correlated to the ratio of the concentration of radioactive Cs between the minerals and the medium solution. These results strongly suggest that the yeast accumulates radioactive Cs competitively with minerals. - Graphical abstract: Autoradiography analysis showed that presence of larger amounts of mineral of vermiculite collected in South Africa induced less accumulation of radioactive Cs in yeast cells from the medium. - Highlights: • Effect of minerals on the accumulation of radioactive Cs by yeast was studied. • Presence of minerals reduced accumulation of radioactive Cs by yeast. • The order of reduction is mica>smectite, illite>>vermiculite, phlogopite

Giant CP stars

International Nuclear Information System (INIS)

Loden, L.O.; Sundman, A.

1989-01-01

This study is part of an investigation of the possibility of using chemically peculiar (CP) stars to map local galactic structure. Correct luminosities of these stars are therefore crucial. CP stars are generally regarded as main-sequence or near-main-sequence objects. However, some CP stars have been classified as giants. A selection of stars, classified in literature as CP giants, are compared to normal stars in the same effective temperature interval and to ordinary 'non giant' CP stars. There is no clear confirmation of a higher luminosity for 'CP giants', than for CP stars in general. In addition, CP characteristics seem to be individual properties not repeated in a component star or other cluster members. (author). 50 refs., 5 tabs., 3 figs

Facile synthesis of CsPbBr3/PbSe composite clusters.

Science.gov (United States)

Nguyen, Thang Phan; Ozturk, Abdullah; Park, Jongee; Sohn, Woonbae; Lee, Tae Hyung; Jang, Ho Won; Kim, Soo Young

2018-01-01

In this work, CsPbBr 3 and PbSe nanocomposites were synthesized to protect perovskite material from self-enlargement during reaction. UV absorption and photoluminescence (PL) spectra indicate that the addition of Se into CsPbBr 3 quantum dots modified the electronic structure of CsPbBr 3 , increasing the band gap from 2.38 to 2.48 eV as the Cs:Se ratio increased to 1:3. Thus, the emission color of CsPbBr 3 perovskite quantum dots was modified from green to blue by increasing the Se ratio in composites. According to X-ray diffraction patterns, the structure of CsPbBr 3 quantum dots changed from cubic to orthorhombic due to the introduction of PbSe at the surface. Transmission electron microscopy and X-ray photoemission spectroscopy confirmed that the atomic distribution in CsPbBr 3 /PbSe composite clusters is uniform and the composite materials were well formed. The PL intensity of a CsPbBr 3 /PbSe sample with a 1:1 Cs:Se ratio maintained 50% of its initial intensity after keeping the sample for 81 h in air, while the PL intensity of CsPbBr 3 reduced to 20% of its initial intensity. Therefore, it is considered that low amounts of Se could improve the stability of CsPbBr 3 quantum dots.

Bursting star formation and the overabundance of Wolf-Rayet stars

International Nuclear Information System (INIS)

Bodigfee, G.; Deloore, C.

1985-01-01

The ratio of the number of WR-stars to their OB progenitors appears to be significantly higher in some extragalactic systems than in our Galaxy. This overabundance of Wolf-Rayet-stars can be explained as a consequence of a recent burst of star formation. It is suggested that this burst is the manifestation of a long period nonlinear oscillation in the star formation process, produced by positive feedback effects between young stars and the interstellar medium. Star burst galaxies with large numbers of WR-stars must generate gamma fluxes but due to the distance, all of them are beyond the reach of present-day detectors, except probably 30 Dor

Chemical complexity in the winds of the oxygen-rich supergiant star VY Canis Majoris

Science.gov (United States)

Ziurys, L. M.; Milam, S. N.; Apponi, A. J.; Woolf, N. J.

2007-06-01

The interstellar medium is enriched primarily by matter ejected from old, evolved stars. The outflows from these stars create spherical envelopes, which foster gas-phase chemistry. The chemical complexity in circumstellar shells was originally thought to be dominated by the elemental carbon to oxygen ratio. Observations have suggested that envelopes with more carbon than oxygen have a significantly greater abundance of molecules than their oxygen-rich analogues. Here we report observations of molecules in the oxygen-rich shell of the red supergiant star VY Canis Majoris (VY CMa). A variety of unexpected chemical compounds have been identified, including NaCl, PN, HNC and HCO+. From the spectral line profiles, the molecules can be distinguished as arising from three distinct kinematic regions: a spherical outflow, a tightly collimated, blue-shifted expansion, and a directed, red-shifted flow. Certain species (SiO, PN and NaCl) exclusively trace the spherical flow, whereas HNC and sulphur-bearing molecules (amongst others) are selectively created in the two expansions, perhaps arising from shock waves. CO, HCN, CS and HCO+ exist in all three components. Despite the oxygen-rich environment, HCN seems to be as abundant as CO. These results suggest that oxygen-rich shells may be as chemically diverse as their carbon counterparts.

Determination of {sup 135}Cs by accelerator mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

MacDonald, C.M.; Charles, C.R.J. [Andre. E. Lalonde AMS Laboratory, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Department of Earth Sciences, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Zhao, X.-L.; Kieser, W.E. [Andre. E. Lalonde AMS Laboratory, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Cornett, R.J. [Andre. E. Lalonde AMS Laboratory, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Department of Earth Sciences, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Litherland, A.E. [IsoTrace Laboratory, University of Toronto, 60 St. George St., Toronto, ON M5S 1A7 (Canada)

2015-10-15

The ratio of anthropogenic {sup 135}Cs and {sup 137}Cs isotopes is characteristic of a uranium fission source. This research evaluates the technique of isotope dilution (yield tracing) for the purpose of quantifying {sup 135}Cs by accelerator mass spectrometry with on-line isobar separation. Interferences from Ba, Zn{sub 2}, and isotopes of equal mass to charge ratios were successfully suppressed. However, some sample crosstalk from source contamination remains. The transmission and di-fluoride ionization efficiencies of Cs isotopes were found to be 8 × 10{sup −3} and 1.7 × 10{sup −7} respectively. This quantification of {sup 135}Cs using yield tracing by accelerator mass spectrometry shows promise for future environmental sample analysis once the issues of sample crosstalk and low efficiency can be resolved.

The TiO2 Refraction Film for CsI Scintillator

OpenAIRE

C. C. Chen; C. W. Hun; C. J. Wang; C. Y. Chen; J. S. Lin; K. J. Huang

2015-01-01

Cesium iodide (CsI) melt was injected into anodic aluminum oxide (AAO) template and was solidified to CsI column. The controllable AAO channel size (10~500 nm) can makes CsI column size from 10 to 500 nm in diameter. In order to have a shorter light irradiate from each singe CsI column top to bottom the AAO template was coated a TiO2 nano-film. The TiO2 film acts a refraction film and makes X-ray has a shorter irradiation path in the CsI crystal making a stronger the photo-electron signal. Wh...

Dynamic modelling of Cs-137 contamination in Denmark

International Nuclear Information System (INIS)

Oehlenschlaeger, M.

1989-01-01

The paper describes the structure of a dynamic food-chain transport model for Cs-137 in the Danish terrestrial environment. The model solves a set of linear, coupled differential equations in order to estimate the inventories and concentrations of Cs-137 in the soil, vegetation, animal tissue and animal product as a function of time based on the Cs-137 concentrations in the air after an accidental release. Meteorological conditions and seasonal variations in agricultural practice are included. (orig.)

Recent levels of radionuclides in lichens from southwest Poland with particular reference to 134Cs and 137Cs

International Nuclear Information System (INIS)

Seaward, M.R.D.; Bylinska, E.A.

1988-01-01

Analyses of Umbilicaria species collected from southwest Poland in August 1986 have shown there to be significant increases in levels of various radionuclides since previous analyses based on fieldwork in 1978-1979. The composition and ratio of the various radionuclides, particularly in respect of 134 Cs and 137 Cs, exhibit a characteristic signature consistent with contamination derived from the accident at the Chernobyl nuclear reactor in April 1986. Intraspecific variation in levels of 137 Cs in Umbilicaria is related to such factors as location, altitude and, to a lesser degree, aspect; interspecific variation in levels is related to ecological requirements and geographical pattern, and hence the same factors, although morphological differences in thalli may be implicated. (author)

TRIGGERED STAR FORMATION SURROUNDING WOLF-RAYET STAR HD 211853

Energy Technology Data Exchange (ETDEWEB)

Liu Tie; Wu Yuefang; Zhang Huawei [Department of Astronomy, Peking University, 100871 Beijing (China); Qin Shengli, E-mail: liutiepku@gmail.com [I. Physikalisches Institut, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany)

2012-05-20

The environment surrounding Wolf-Rayet (W-R) star HD 211853 is studied in molecular, infrared, as well as radio, and H I emission. The molecular ring consists of well-separated cores, which have a volume density of 10{sup 3} cm{sup -3} and kinematic temperature {approx}20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From the spectral energy distribution modeling toward the young stellar objects, the sequential star formation is revealed on a large scale in space spreading from the W-R star to the molecular ring. A small-scale sequential star formation is revealed toward core 'A', which harbors a very young star cluster. Triggered star formations are thus suggested. The presence of the photodissociation region, the fragmentation of the molecular ring, the collapse of the cores, and the large-scale sequential star formation indicate that the 'collect and collapse' process functions in this region. The star-forming activities in core 'A' seem to be affected by the 'radiation-driven implosion' process.

TRIGGERED STAR FORMATION SURROUNDING WOLF-RAYET STAR HD 211853

International Nuclear Information System (INIS)

Liu Tie; Wu Yuefang; Zhang Huawei; Qin Shengli

2012-01-01

The environment surrounding Wolf-Rayet (W-R) star HD 211853 is studied in molecular, infrared, as well as radio, and H I emission. The molecular ring consists of well-separated cores, which have a volume density of 10 3 cm –3 and kinematic temperature ∼20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From the spectral energy distribution modeling toward the young stellar objects, the sequential star formation is revealed on a large scale in space spreading from the W-R star to the molecular ring. A small-scale sequential star formation is revealed toward core 'A', which harbors a very young star cluster. Triggered star formations are thus suggested. The presence of the photodissociation region, the fragmentation of the molecular ring, the collapse of the cores, and the large-scale sequential star formation indicate that the 'collect and collapse' process functions in this region. The star-forming activities in core 'A' seem to be affected by the 'radiation-driven implosion' process.

CsPb2Br5 Single Crystals: Synthesis and Characterization

KAUST Repository

Dursun, Ibrahim

2017-08-02

CsPb2Br5 is a ternary halogen-plumbate material with close characteristics to well-reported halide perovskites. Due to its unconventional two-dimensional structure, CsPb2Br5 is being looked at broadly for potential applications in optoelectronics. CsPb2Br5 investigations are currently limited to nanostructures and powder forms of the material, which present unclear and conflicting optical properties. In this study, we present the synthesis and characterization of CsPb2Br5 bulk single crystals, which enabled us to finally clarify the material\\'s optical features. Our CsPb2Br5 crystal has a two-dimensional structure with Pb2Br5- layers spaced by Cs+ cations, and exhibits a ~3.1 eV indirect bandgap with no emission in the visible spectrum.

Concentration factors for 137Cs in Japanese coastal fish (1984-1990)

International Nuclear Information System (INIS)

Tateda, Yutaka; Koyanagi, Taku.

1996-01-01

Concentration factors (CFs; Bq kg -1 wet in fish muscle/Bq kg -1 in filtered seawater) for 137 Cs were determined in Japanese coastal fish collected from 1984 to 1990. 137 Cs/Cs (stable) atom ratios were also examined to clarify the distribution equilibrium of 137 Cs-between marine fish and seawater. The geometric mean of CF in Japanese coastal fish was 52±4 (standard error of the mean), with values ranging from 14 to 133. 137 Cs/Cs atom ratios both in marine fish and seawater indicate that the distribution of 137 Cs was in equilibrium between fish muscle and seawater. Therefore, CF values obtained in the present study can be regarded as equilibrated. Our results show that the CFs for 137 Cs in Japanese coastal fish were within the range of Japanese guidelines, but were below the recommended IAEA value. (author)

On the cesium-rich part of the Cs-Te phase diagram

International Nuclear Information System (INIS)

Boer, R. de; Cordfunke, E.H.P.

1995-03-01

The cesium-tellurium system in the region between 33 and 55 at.% Te has been investigated with X-ray diffraction and DSC. The existence of the compounds Cs 5 Te 3 and CsTe is demonstrated. The latter compound exhibits a structural transition at elevated temperature, as does the compound Cs 2 Te. The earlier reported compounds Cs 3 Te 2 and Cs 5 Te 4 do not exist. (orig.)

Photon Reabsorption in Mixed CsPbCl3:CsPbI3 Perovskite Nanocrystal Films for Light-Emitting Diodes

KAUST Repository

Davis, Nathaniel J. L. K.

2017-01-24

Cesium lead halide nanocrystals, CsPbX3 (X = Cl, Br, I), exhibit photoluminescence quantum efficiencies approaching 100% without the core–shell structures usually used in conventional semiconductor nanocrystals. These high photoluminescence efficiencies make these crystals ideal candidates for light-emitting diodes (LEDs). However, because of the large surface area to volume ratio, halogen exchange between perovskite nanocrystals of different compositions occurs rapidly, which is one of the limiting factors for white-light applications requiring a mixture of different crystal compositions to achieve a broad emission spectrum. Here, we use mixtures of chloride and iodide CsPbX3 (X = Cl, I) perovskite nanocrystals where anion exchange is significantly reduced. We investigate samples containing mixtures of perovskite nanocrystals with different compositions and study the resulting optical and electrical interactions. We report excitation transfer from CsPbCl3 to CsPbI3 in solution and within a poly(methyl methacrylate) matrix via photon reabsorption, which also occurs in electrically excited crystals in bulk heterojunction LEDs.

Electronic structure, photoemission spectra, and vacuum-ultraviolet optical spectra of CsPbCl3 and CsPbBr3

Science.gov (United States)

Heidrich, K.; Schäfer, W.; Schreiber, M.; Söchtig, J.; Trendel, G.; Treusch, J.; Grandke, T.; Stolz, H. J.

1981-11-01

Optical spectra of CsPbCl3 and CsPbBr3 have been measured in the range from 2 to 10 eV and have been combined with ultraviolet-photoemission-spectroscopy (UPS)-measurements at 21.1 and 40.8 eV. A quantitative band calculation is presented, which takes into account anion-anion interaction as well as electronic states of the Cs+ ion. The prominent features of earlier band models and measurements are reestablished through our measurements and calculations, namely that the valence band consists of anionic p functions and Pb 6s functions, the lowest conduction band being Pb 6p type, and the lowest gap occuring at the R point of the Brillouin zone. Inclusion of a further (Cs 6s-type) conduction band, however, is necessary to bring the calculated joint density of states into agreement with vacuum-ultraviolet optical spectra. The calculated densities of states of the valence bands are in quantitative agreement with those deduced from our UPS measurements.

Cs phytoremediation by Sorghum bicolor cultivated in soil and in hydroponic system.

Science.gov (United States)

Wang, Xu; Chen, Can; Wang, Jianlong

2017-04-03

Cs accumulation characteristics by Sorghum bicolor were investigated in hydroponic system (Cs level at 50-1000 μmol/L) and in soil (Cs-spiked concentration was 100 and 400 mg/kg soil). Two varieties of S. bicolor Cowly and Nengsi 2# grown on pot soil during the entire growth period (100 days) did not show significant differences on the height, dry weight (DW), and Cs accumulation. S. bicolor showed the potential phytoextraction ability for Cs-contaminated soil with the bioaccumulation factor (BCF) and the translocation factor (TF) values usually higher than 1 in soil system and in hydroponic system. The aerial parts of S. bicolor contributed to 86-92% of the total removed amounts of Cs from soil. Cs level in solution at 100 μmol/L gave the highest BCF and TF values of S. bicolor. Cs at low level tended to transfer to the aerial parts, whereas Cs at high level decreased the transfer ratio from root to shoot. In soil, the plant grew well when Cs spiked level was 100 mg/kg soil, but was inhibited by Cs at 400 mg/kg soil with Cs content in sorghum reaching 1147 mg/kg (roots), 2473 mg/kg (stems), and 2939 mg/kg (leaves). In hydroponic system, average Cs level in sorghum reached 5270 mg/kg (roots) and 4513 mg/kg (aerial parts), without significant damages to its biomass at 30 days after starting Cs treatment. Cs accumulation in sorghum tissues was positively correlated with the metal concentration in medium.

Temperature-dependent Raman spectra and electrical properties of 0.69Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-0.31PbTiO{sub 3} single crystals

Energy Technology Data Exchange (ETDEWEB)

Fang, Bijun [Changzhou University, School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou (China); Liu, Xing [Changzhou University, School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou (China); Chinese Academy of Sciences, Key Laboratory of Inorganic Function Material and Device, Shanghai (China); Li, Xiaobing; Zhao, Xiangyong; Luo, Haosu [Chinese Academy of Sciences, Key Laboratory of Inorganic Function Material and Device, Shanghai (China); Ding, Jianning [Changzhou University, School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou (China); Jiangsu University, School of Material Science and Engineering, Zhenjiang (China)

2016-09-15

The temperature-dependent Raman spectra and electrical properties of the 0.69Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-0.31PbTiO{sub 3} (0.69PMN-0.31PT) single crystals were investigated. Based on the group theory, the poled 0.69PMN-0.31PT single crystals belong to the monoclinic crystal system, which was confirmed by the room-temperature Raman spectra. The 0.69PMN-0.31PT single crystals experience successive structural phase transitions, i.e., a monoclinic-tetragonal (FE{sub M}-FE{sub T}) phase transition at T{sub M-T} and a tetragonal-cubic (FE{sub T}-P{sub C}) phase transition at T{sub m} determined by the dielectric measurement. Due to the enhancement of long-range order, their FE{sub M}-FE{sub T} phase transition becomes more obvious after the poling process. The wavenumbers and line widths of the 271, 502, 575, 795 cm{sup -1} Raman modes, and the intensity ratios of I{sub 271cm}{sup {sub -}{sub 1}}/I{sub 795cm}{sup {sub -}{sub 1}} and I{sub 502cm}{sup {sub -}{sub 1}}/I{sub 575cm}{sup {sub -}{sub 1}} exhibit obvious anomalies around T{sub M-T} and T{sub m}, which are closely related to the FE{sub M}-FE{sub T} and FE{sub T}-P{sub C} phase transitions. The temperature and electric field (E)-induced phase transitions are observed in the unipolar strain-E (S-E) curves. The converse piezoelectric constant (d{sub 33}), maximum strain value (S{sub max}%) and longitudinal electrostrictive coefficient (Q) increase considerably around the ferroelectric phase transition temperature T{sub M-T}. (orig.)

Dissolution behavior of 137Cs absorbed on the green tea leaves

International Nuclear Information System (INIS)

Oya, Yasuhisa; Uchimura, Hiromichi; Toda, Kensuke; Okuno, Kenji; Ikka, Takashi; Morita, Akio

2013-01-01

The green tea leaves was dipped in the 137 CsCl solution to elucidate the dissolution behavior of 137 Cs contaminated on the green tea leaves. It was found that the amount of 137 Cs dissolved into tea water was controlled by the temperature of water, and the activation energy of 137 Cs dissolution was estimated to be 0.045 eV, indicating that most of 137 Cs would exist as the adsorbed state. In addition, the dissolution behavior was controlled by the concentration of stable Cs dissolved in water, although no large correlation with pH was observed. (author)

Star Polymers.

Science.gov (United States)

Ren, Jing M; McKenzie, Thomas G; Fu, Qiang; Wong, Edgar H H; Xu, Jiangtao; An, Zesheng; Shanmugam, Sivaprakash; Davis, Thomas P; Boyer, Cyrille; Qiao, Greg G

2016-06-22

Recent advances in controlled/living polymerization techniques and highly efficient coupling chemistries have enabled the facile synthesis of complex polymer architectures with controlled dimensions and functionality. As an example, star polymers consist of many linear polymers fused at a central point with a large number of chain end functionalities. Owing to this exclusive structure, star polymers exhibit some remarkable characteristics and properties unattainable by simple linear polymers. Hence, they constitute a unique class of technologically important nanomaterials that have been utilized or are currently under audition for many applications in life sciences and nanotechnologies. This article first provides a comprehensive summary of synthetic strategies towards star polymers, then reviews the latest developments in the synthesis and characterization methods of star macromolecules, and lastly outlines emerging applications and current commercial use of star-shaped polymers. The aim of this work is to promote star polymer research, generate new avenues of scientific investigation, and provide contemporary perspectives on chemical innovation that may expedite the commercialization of new star nanomaterials. We envision in the not-too-distant future star polymers will play an increasingly important role in materials science and nanotechnology in both academic and industrial settings.

Detection of CS in Neptune's atmosphere from ALMA observations

Science.gov (United States)

Moreno, R.; Lellouch, E.; Cavalié, T.; Moullet, A.

2017-12-01

Context. The large and vertically non-uniform abundance of CO in Neptune's atmosphere has been interpreted as the result of past cometary impact(s), either single or distributed in size and time, which could also be at the origin of Neptune's HCN. Aims: We aim to provide observational support for this scenario by searching for other comet-induced species, in particular carbon sulfide (CS) which has been observed continuously in Jupiter since the 1994 Shoemaker-Levy 9 impacts. Methods: In April 2016 we used the ALMA interferometer to search for CS(7-6) at 342.883 GHz in Neptune. Results: We report on the detection of CS in Neptune's atmosphere, the first unambiguous observation of a sulfur-bearing species in a giant planet beyond Jupiter. Carbon sulfide appears to be present only at submillibar levels, with a column density of (2.0-3.1) × 1012 cm-2, and a typical mixing ratio of (2-20) × 10-11 that depends on its precise vertical location. The favoured origin of CS is deposition by a putative large comet impact several centuries ago, and the strong depletion of CS with respect to CO - compared to the Jupiter case - is likely due to the CS sticking to aerosols or clustering to form polymers in Neptune's lower stratosphere. Conclusions: The CS detection, along with recent analyses of the CO profile, reinforces the presumption of a large comet impact into Neptune 1000 yr ago, that delivered CO, CS, and HCN at the same time.

Lattice dynamics of cubic Cs2NaLnX6 and CsNaLn1-xLn'xX6 elpasolites

International Nuclear Information System (INIS)

Acevedo, R.; Poblete, V.; Alzamora, R.; Venegas, R.; Navarro, G.; Henriquez, C.

1999-01-01

Crystal lattice dynamics of stoichiometric Cs 2 NaLnX 6 and nonstoichiometric CsNaLn 1-x Ln' x X 6 , 0.01 ≤ x ≤ 0.10, Ln and Ln' are trivalent positive lanthanide ions and X is chlorine or bromine, were studied.. Phonon dispersion relations were computed for similar compound, Cs 2 UBr 6 , and vibronic absorption spectra with reduced number of required input parameters are considered on the basis of proposed model. (author)

Wolf-Rayet stars

Energy Technology Data Exchange (ETDEWEB)

Sahade, J

1981-12-01

Aspects of the problems of the Wolf-Rayet stars related to their chemical composition, their evolutionary status, and their apparent dichotomy in two spectral sequences are discussed. Dogmas concerning WR stars are critically discussed, including the belief that WR stars lack hydrogen, that they are helium stars evolved from massive close binaries, and the existence of a second WR stage in which the star is a short-period single-lined binary. The relationship of WR stars with planetary nebulae is addressed, as is the membership of these stars in clusters and associations. The division of WR stars into WN and WC sequences is considered, questioning the reasonability of accounting for WR line formation in terms of abundance differences.

Soil 137Cs background values in monsoon region of china

International Nuclear Information System (INIS)

Zhang Mingli; Yang Hao; Wang Xiaolei; Wang Yihong; Xu Congan; Yang Jiudong; Rong Jing

2009-01-01

Land degradation,, which is resulted from the soil erosion, is one of the major environmental problems. It severely affects the food supplies, environmental safety and the sustainable development in China. Some areas in the monsoon region are suffering from the acute soil erosion. To find out the degree of soil erosion, the proven technique of 137 Cs tracer is definitely one of the best methods, and the key is to ascertain the accuracy of soil 137 Cs background value. The distributions of 137 Cs were explored in soil profiles by detecting the 137 Cs of soil cores from the Yimeng mountain area in Shandong Province, hills in the southern area of Jiangsu Province and Dianchi catchment in Yunnan Province, respectively. We found that the depth of 137 Cs distribution is not the same in the soils of various areas. But the 137 Cs activity shows an exponential distribution in the uncultivated soil and demonstrates a strong correlation with the soil depth, while the 137 Cs activity proves uniform in the soil plowing layer of the cultivated land. The study shows the 137 Cs background values of three areas: 1737.1 Bq/m 2 in Yimeng mountain area, 1847.6 Bq/m 2 in southern area of hills in Jiangsu, 918.0 Bq/m 2 in Dianchi catchment. The certainty of 137 Cs background value can technically support the use of 137 Cs technique to study the spatial pattern of soil erosion, deposition and the land degradation, which provides the support for the sustainable utilization of soil resource, the assessment of economical benefit and loss and the evaluation of water and soil conservation measures. (authors)

Effect of minerals on accumulation of Cs by fungus Saccaromyces cerevisiae.

Science.gov (United States)

Ohnuki, Toshihiko; Sakamoto, Fuminori; Yamasaki, Shinya; Kozai, Naofumi; Shiotsu, Hiroyuki; Utsunomiya, Satoshi; Watanabe, Naoko; Kozaki, Tamotsu

2015-06-01

The accumulation of Cs by unicellular fungus of Saccharomyces cerevisiae in the presence of minerals has been studied to elucidate the role of microorganisms in the migration of radioactive Cs in the environment. Two different types of experiments were employed: experiments using stable Cs to examine the effect of a carbon source on the accumulation of Cs, and accumulation experiments of radioactive Cs from agar medium containing (137)Cs and zeolite, vermiculite, phlogopite, smectite, mica, or illite as mineral supplements. In the former type of experiments, the Cs-accumulated cells were analyzed by scanning electron microscopy equipped with energy dispersive X-ray analysis (SEM-EDS). In the latter type, the radioactivity in the yeast cells was measured by an autoradiography technique. When a carbon source was present, higher amounts of Cs accumulated in the cells than in the resting condition without a carbon source. Analyses with SEM-EDS showed that no mineral formed on the cell surface. These results indicate that the yeast cells accumulate Cs by adsorption on the cell surface and intracellular accumulation. In the presence of minerals in the agar medium, the radioactivity in the yeast cells was in the order of mica > smectite, illite > vermiculite, phlogopite, zeolite. This order is inversely correlated to the ratio of the concentration of radioactive Cs between the minerals and the medium solution. These results strongly suggest that the yeast accumulates radioactive Cs competitively with minerals. Copyright © 2015 Elsevier Ltd. All rights reserved.

WESF (173)Cs gamma ray sources

Science.gov (United States)

Kenna, B. T.

1984-10-01

The Waste Encapsulation and Storage Facility (WESP) at Hanford, Washington has been separating cesium from stored liquid defense waste since 1945. This is done to alleviate the heat generated by the decay of radioactive Cs137. The cesium is converted to CsCl, doubly encapsulated in 316l stainless steel, and placed in storage. The potential utility of these Cs137 capsules as gamma radiation sources was demonstrated. Registration of the capsule with the NRC as a sealed gamma source would facilitate the licensing of non-DOE irradiation facilities using this source. To grant this registration, the NRC requires characteristics of the capsule. It must also be demonstrated that the capsule will maintain its integrity under both normal circumstances and specified abnormal conditions. The required information is provided through collation of results of studies and tests done previously by other laboratories.

StarDOM: From STAR format to XML

International Nuclear Information System (INIS)

Linge, Jens P.; Nilges, Michael; Ehrlich, Lutz

1999-01-01

StarDOM is a software package for the representation of STAR files as document object models and the conversion of STAR files into XML. This allows interactive navigation by using the Document Object Model representation of the data as well as easy access by XML query languages. As an example application, the entire BioMagResBank has been transformed into XML format. Using an XML query language, statistical queries on the collected NMR data sets can be constructed with very little effort. The BioMagResBank/XML data and the software can be obtained at http://www.nmr.embl-heidelberg.de/nmr/StarDOM/

Experimental and computation method for determination of burnup and isotopic composition of the WWER-440 fuel using the 134Cs and 137Cs concentrations

International Nuclear Information System (INIS)

Babichev, B.A.; Kozharin, V.V.

1990-01-01

An experimental and computational method for determination of burnup and actinoid concentrations in WWER fuel elements using 134 Cs and 137 Cs concentrations in fuel is considered. It is shown that the error in calculation of fuel burnup and U and Pu isotope concentrations in WWER-440 fuel elements is 1.3-4.9% provided that the error in 134 Cs and 137 Cs concentration measurements does not exceed 1.7 and 1.2%. 9 refs.; 10 figs.; 4 tabs

Sequestration and disposal of dissolved Cs+ using zeolite 13X

Science.gov (United States)

Park, M.; Park, J.; Jeong, H. Y.

2017-12-01

Low-to-intermediate level liquid radioactive wastes (LILLW) typically contain high levels of radioactive 137Cs. Due to the great radiational and thermal stability as well as the high selectivity, zeolite has been commonly utilized to sequester radioactive isotopes from nuclear wastewater effluents. In this study, an Al-rich synthetic zeolite 13X was evaluated for the sorption capacity of Cs+ as a function of pH (4.0-10.5), ionic strength (0.05 and 0.2 M), and initial Cs+ concentration (1×10-6-5×10-3 M). For safe disposal, Cs+-exchanged 13X was both thermally and hydrothermally treated under different temperature and pressure. Subsequently, the resultant materials were examined for the phase transition by X-ray diffraction (XRD) and the local coordination chemistry by X-ray absorption spectroscopy (XAS). Our experimental results will detail the Cs+ sorption behavior by 13X under varying solution compositions. Also, the structural changes of Cs+-exchanged 13X upon thermal and hydrothermal treatment will be delineated to assess the stability of Cs+ in the treated materials.

Pulsed Cs beam development for the BNL polarized H- source

International Nuclear Information System (INIS)

Alessi, J.G.

1983-01-01

A pulsed Cs + beam has been developed for use on a polarized H - source. Cesium ion production is by surface ionization using a porous tungsten ionizer. While satisfactory current pulses (5 to 10 mA greater than or equal to 0.5 ms) can be obtained, the pulse shapes are a sensitive function of the ionizer temperature and Cs surface coverage. The beam optical requirements are stringent, and the optics have been studied experimentally for both Cs + and Cs 0 beams. Computer calculations are in good agreement with the observed results. The present source has delivered 2.6 mA of Cs + through the interaction region of the polarized ion source, and as much as 2.0 particle mA of Cs 0 . A new source is being built which is designed to give 15 mA through the interaction region

STARS no star on Kauai

International Nuclear Information System (INIS)

Jones, M.

1993-01-01

The island of Kuai, home to the Pacific Missile Range Facility, is preparing for the first of a series of Star Wars rocket launches expected to begin early this year. The Strategic Defense Initiative plans 40 launches of the Stategic Target System (STARS) over a 10-year period. The focus of the tests appears to be weapons and sensors designed to combat multiple-warhead ICBMs, which will be banned under the START II Treaty that was signed in January. The focus of this article is to express the dubious value of testing the STARS at a time when their application will not be an anticipated problem

Speciation of Cs-137 in fertilizers amended soils

International Nuclear Information System (INIS)

Mocanu, N.; Breban, D.C.

1999-01-01

One of the most used agricultural countermeasures to reduce the uptake of radionuclides from soil into plants is the chemical treatment of the soil with fertilizers. The distribution of a radionuclide between different physico chemical forms is essential to characterize its behaviour and the biological impact on the environment. To assess a radionuclide bioavailability to the soil-plant transfer, the chemical forms that are most relevant are the water soluble and exchangeable ones. Laboratory experiments were conducted to determine the potential modifications in time of the Cs-137 distribution in the two soil fractions, induced by the treatment with different K-based fertilizers. The two types of soil were selected taking into account their importance for the agricultural use in Romania. By the sequential extraction method the distribution of 137 Cs has been determined in the water soluble and exchangeable fractions separated from the soils after 1 day, 1 week, 1 month and 4 months, respectively. For the reference untreated soils, experimental data revealed that less than 1 percent of Cs-137 is associated to the water soluble fraction for both types of soil. Around 4 percents of the total amount of Cs-137 in the brown-reddish soil and 13 percents in the alluvial one were associated to the exchangeable fraction. The differences between the Cs-137 distribution are correlated to the higher content of dust and clay in the brown reddish soil, which are strong binders for Cs ions. The application of the two fertilizers releasing fast the K ions (KCl and potassium salt), determined from at the first moment after the contamination a reduction of the Cs-137 concentration in both fraction. The effect was most pronounced for the soluble fraction in the brown -reddish soil: with a factor of 8 in case of KCl treatment and 5 in case of potassium salt. For the others experimental cases the concentration of Cs-137 in both fractions was slightly reduced, with factors between (1

Biological effects of 137Cs, incorporated into organism of rats

International Nuclear Information System (INIS)

Monakhov, A.S.; Strekalov, S.A.; Sokolov, A.V.; Aver'yanova, T.K.

1987-01-01

Results of investigating mutagenous and hemotoxic effects of 137 Cs on blood lymphocytes of rats are presented. 137 Cs was orally administrated into organism of rats as 270 kBq/g chloride solution. 137 Cs mutagenous effect was studied on metaphase plates of rat blood lymphocytes in course of rats lifetime experiment. It is stated that 137 Cs inducing severe disturbances of genetic material in a great quantity of blood lymphocytes, causes their total killing

The effect of clinoptilolite on 137 Cs binding in broiler chickens

Directory of Open Access Journals (Sweden)

G. VITOROVIC

2008-12-01

Full Text Available The objective of this study was to evaluate the 137 Cs binding capacity of clinoptilolite.In the first in vitro experiment we investigated sorption of 137 Cs to natural and modified forms of clinoptilolite in highly acid solution,prepared to be similar to that of the gut of pigs (pH =2 3at 37 ºC.In the second in vivo experiment 137 Cs binding to a modified form of clinoptilolite was studied in orally contaminated broiler chickens.137 Cs sorption in the high acidity solution depended on clinoptilolite concentration and varied between 30 85 %of the initial activity.In the chickens,three hours after 137 Cs administration,there was 67%and 63%lower accumulation of 137 Cs in meat and edible organs (respectivelyand seven hours after 137 Cs administration,there was 69% and 49% lower accumulation of 137 Cs in meat and edible organs (respectivelycompared to the controls with no clinoptilolite added in food. Natural and modified forms of clinoptilolite have been shown to high sorption efficiency towards 137 Cs ions and could be recommended as possible radiocaesium binders in domestic animals.;

137Cs use in estimating soil erosion: 30 years of research

International Nuclear Information System (INIS)

Ritchie, J.C.

1998-01-01

Significant amounts of fallout 137 Cs from nuclear weapons tests were introduced to the landscape during the 1950s and 1960s. Once 137 Cs reaches the soil surface it is strongly and quickly adsorbed by clay particles, and is essentially nonexchangeable in most environments. Thus, 137 Cs becomes and effective tracer of the movement of soil particles across the landscape. Over the past 30 years, researchers have shown that 137 Cs can be used to study soil movement. Early work used empirical relationships between soil loss and 137 Cs loss to estimate erosion. This was followed by the development of proportional and theoretical models to relate 137 Cs movement and soil redistribution. Most of the problems related to the 137 Cs technique are the same as those encountered with other techniques (i.e., sampling, measurement). The 137 Cs technique can make actual measurements of soil loss and redeposition in fields, fostering the formulation of better plans to conserve the quality of the landscape. This paper reviews the development of the 137 Cs technique to show how it can be used to understand erosion and soil movement on the landscape. (author)

Behaviour of 137Cs in the Boreal forest ecosystem of central Sweden

International Nuclear Information System (INIS)

Fawaris, B.H.

1995-01-01

Behaviour of Chernobyl fallout 1 37 Cs in a coniferous forest ecosystem in central Sweden was investigated between 1990 and 1994. Results demonstrated that forest soil belongs to nutrient deficient type, and deposited fallout 1 37 Cs from Chernobyl nuclear accident (CNA) was retained (85%) in the upper 5 cm of humic forest soil layer, with a venial migration deeper into soil profile. No correlation between forest soil exchangeable and total potassium (K + ) and 1 37 Cs transfer parameters was observed. However, addition of K + , found to efficiently reduce 1 37 Cs uptake by sheep's fescue and the addition of stable caesium (1 33 Cs + ) enhanced it. The addition of ammonium (NH 4 + ) was slightly stimulating the uptake of 1 37 Cs by sheep's fescue in the first cut only. Field plants showed a considerably reduction in their 1 37 Cs activity concentrations. Relative to their 1 37 Cs levels of 1986-89, a little reduction in heather (16%) occurred eight years after CNA. In contrast the reductions in lingonberry and bilberry were 87% and 68%, respectively. Three fractions of forest soil bound 1 37 Cs were observed due to sequential extraction procedure (SEP). The first, is easily extractable 1 37 Cs fraction (F1+F2), it comprises 22% of total forest soil 1 37 Cs inventory in the upper 5 cm layer. The second, is soil organically and biologically bound 1 37 Cs (F3+F4) comprises about 30% of soil bound 1 37 Cs. This fraction might be accounted for long-term soil available 1 37 Cs for plant uptake after bio-degradation processes by soil microorganisms. The third, is the residual fraction (F5), it comprises more than 35% of total forest soil 1 37 Cs inventory, and may be associated with soil components which are probably of organic nature. Sorption of 1 37 Cs by zeolite (Mordenite) revealed that soil bound 1 37 Cs is to some extent more mobile in forest soils with high OM% and low pH than those with low OM%. 99 refs

Study of 137Cs absorption by Lemna minor

International Nuclear Information System (INIS)

Bergamini, P.G.; Palmas, G.; Piantelli, F.; Sani, M.; Banditelli, P.; Previtera, M.; Sodi, F.

1979-01-01

Absorption of 137 Cs by the floating aquatic plant Lemna Minor in relation to 137 Cs concentration in the water was measured under controlled conditions of temperature, pH and light. The method used to analyse the results is described. When applied to this study the method shows the influence on 137 Cs absorption of (1) potassium-cesium exchange due to chemical affinity, (2) the natural colony growth of the organism and (3) the effect of light. Concentration factors were determined for these three processes. (author)

Radioactive caesium (134Cs and 137Cs) in mushrooms of the genus Boletus from the Reggio Emilia in Italy and Pomerania in Poland.

Science.gov (United States)

Cocchi, Luigi; Kluza, Karolina; Zalewska, Tamara; Apanel, Anna; Falandysz, Jerzy

2017-12-01

Activity concentrations of 134 Cs and 137 Cs were determined in mushrooms of the Boletus species B. aereus, B. reticulatus, B. appendiculatus, B. calopus, B. edulis, B. erythropus, B. fechtneri, B. pinophilus, B. pseudoregius, B. rhodopurpureus, B. rhodoxanthus collected in the Reggio Emilia, Italy, in 1993 and 1994 and in B. edulis collected in Pomerania in northern Poland in the period from 1995-2015. Boletus edulis from the Reggio Emilia showed presence of 137 Cs at 330 ± 220 Bq kg -1 dry biomass in 1993 and at 370 ± 180 Bq kg -1 dry biomass in 1994. In B. edulis sampled in the Reggio Emilia in 1993 and 1994, the pre-Chernobyl 137 Cs from global fallout amounted to 39-46 % of the total activity concentrations of isotope 137 Cs. B. edulis from Pomerania contained 137 Cs in caps at 270 ± 15 Bq kg -1 dry biomass in 1995, and in whole fruiting bodies it was found to be 470 ± 9 Bq kg -1 dry biomass in 2015. The activity concentrations of 137 Cs determined in fruiting bodies of B. edulis from Pomerania fluctuated but persisted over the period from 1995 to 2015, while the maximum activity concentrations were well below the tolerance limit of 600 Bq kg -1 fresh product.

Five years of monitoring Cs-137 And Cs-134 in moss and soil samples in the campania region of Italy after the Chernobyl accident

International Nuclear Information System (INIS)

Fontana, C.; Tenero, A.Lo; Musumeci, R.G.; Valeriani, F.

2000-01-01

The Central Laboratory of The Italian Red Cross is part of the National Network for the Monitoring of the Environmental Radioactivity in Italy, coordinated by the National Environmental Agency (ANPA). The Central Laboratory took part in the national campaigns for the monitoring of the environmental gamma radioactivity in order to evaluate the deposition of artificial radioactivity on Italian territory after the Chernobyl accident. The distribution of the concentration of artificial radionuclide Cs-137 as reached, in North and Central Italy, the higher values: 2-185 kBq/m 2 and 0-40 kBq/m 2 . This paper presents the data of the concentration of artificial radionuclides Cs-137 and Cs-134 in mosses picked up in four different locations in the Campania Region of Italy with the help of the Department of the State Forestry Corp of S.Gregorio Matese, Vesuvio, Laviano, Piaggine from 1993 to 1998. The deposition of artificial radioactivity on the territory expected after the Chernobyl fallout was evaluated. The content of K-40 was also measured. Soil samples were also taken from the same sites. In this study Hypnum cupressiforme and Homalotecium lutescens mosses were used as bioindicators, available in all Italian ecosystems. The soil and moss samples were gathered according to a national standard procedure. These results, obtained by gamma spectrometry analyses, initially have shown values of medium concentration in mosses in the Campania Region of Cs-137 of 375 Bq/m 2 and of Cs-134 of 16 Bq/m 2 and K-40 of 150 Bq/m 2 in line with the ones of other Italian regions. The results of the average concentrations of the Cs-137 and Cs-134 in the mosses confirm a uniform distribution of post-Chernobyl radioactivity in the regional territory, in the Department of the State Forestry Corp of Vesuvio, Laviano and Piaggine. The results of Cs-137 and Cs-134 of S.Gregorio Matese are in accordance with the previous data relative to the monitoring campaign of mosses in Italy from 1992 to

Analysis on the influence of forest soil characteristics on radioactive Cs infiltration and evaluation of residual radioactive Cs on surfaces.

Science.gov (United States)

Mori, Yoshitomo; Yoneda, Minoru; Shimada, Yoko; Fukutani, Satoshi; Ikegami, Maiko; Shimomura, Ryohei

2018-03-29

We investigated the depth profiles of radioactive Cs, ignition loss, and cation exchange capacity (CEC) in five types of forest soils sampled using scraper plates. We then simulated the monitored depth profiles in a compartment model, taking ignition loss as a parameter based on experimental results showing a positive correlation between ignition loss and the CEC. The calculated values were comparable with the monitored values, though some discrepancy was observed in the middle of the soil layer. Based on decontamination data on the surface dose rate and surface contamination concentration, we newly defined a surface residual index (SRI) to evaluate the residual radioactive Cs on surfaces. The SRI value tended to gradually decrease in forests and unpaved roads and was much smaller in forests and on unpaved roads than on paved roads. The radioactive Cs was assumed to have already infiltrated underground 18 months after the nuclear power plant accident, and the sinking was assumed to be ongoing. The SRI values measured on paved roads suggested that radioactive Cs remained on the surfaces, though a gradual infiltration was observed towards the end of the monitoring term. The SRI value is thought to be effective in grasping the rough condition of residual radioactive Cs quickly at sites of decontamination activity in the field. The SRI value may be serviceable for actual contamination works after further research is done to elucidate points such as the relation between the SRI and the infiltration of radioactive Cs in various types of objects.

Cs-137 and Sr-90 level in diary products

International Nuclear Information System (INIS)

Petukhov, V.L.; Dukhanov, Y.A.; Sevryuk, I.Z.; Patrashkov, S.A.; Korotkevich, O.S.; Gorb, T.S.; Petukhov, I.V.

2003-01-01

About 70% of radioactive substances fell on the territory of the Byelorussian Republic after the Chernobyl Atom Power Station Disaster. Cs-137 and Sr-90 accumulation dynamics was studied in milk of the cows from the highest polluted Braginsky area. 408 milk samples of Black and White cows were investigated. In 1995 average Cs-137 and Sr-90 levels were 61.00 and 3.73 Bk/dm 3 respectively. Cs-137 and Sr-90 levels exceeded Byelorussian Republic upper limits RDU - 96 in 10 and 50% of milk samples respectively. After 5 years (by 2000) Cs-137 and Sr-90 levels had become almost 3 and 2 times less (21.70 Bk/dm 3 and 1.72 Bk/dm 3 respectively). Cs-137 and Sr-90 levels exceeded RDU - 96 in 1.5 and 5.5% of milk samples respectively. In the same periods Cs-137 and Sr-90 levels were 7 and 2 times higher than the similar indexes in the relatively clean Novosibirsk area. Thus, radioactive element levels in milk of Black and White cows of the Byelorussian Republic decreased significantly for the past years. (authors)

Photoelectron Emission Studies in CsBr at 257 nm

International Nuclear Information System (INIS)

Maldonado, Juan R.; Liu, Zhi; Sun, Yun; Pianetta, Piero A.; Pease, Fabian W.

2006-01-01

CsBr/Cr photocathodes were found [1,2] to meet the requirements of a multi-electron beam lithography system operating with a light energy of 4.8 eV (257nm). The fact that photoemission was observed with a light energy below the reported 7.3 eV band gap for CsBr was not understood. This paper presents experimental results on the presence of intra-band gap absorption sites (IBAS) in CsBr thin film photo electron emitters, and presents a model based on IBAS to explain the observed photoelectron emission behavior at energies below band gap. A fluorescence band centered at 330 nm with a FWHM of about 0.34 eV was observed in CsBr/Cr samples under 257 nm laser illumination which can be attributed to IBAS and agrees well with previously obtained synchrotron photoelectron spectra[1] from the valence band of CsBr films

Knudsen cell mass spectrometric study of the Cs2IOH(g) molecule thermodynamics

International Nuclear Information System (INIS)

Roki, F-Z.; Ohnet, M-N.; Fillet, S.; Chatillon, C.; Nuta, I.

2013-01-01

Highlights: • The pronounced ionic character leads to only dissociative ionization processes. • Ions formed are same as those coming from pure dimmers. • De-convolution of the ions origin needs accurate thermodynamic values for the pure gas phase. • Mass spectrometric interpretation has to be performed gradually and as a function of suitable condensed compositions. • Thermal functions have to be fully estimated. -- Abstract: The gas phase of the CsI + CsOH system is analyzed by high temperature Knudsen cell mass spectrometry in order to confirm the existence of the Cs 2 IOH(g) complex molecule. The mass spectrometric analysis is quite complex since such molecules undergo dissociative ionization into fragment ions that mix with the same ions from dimers of the pure compounds in the same vapor phase. Varying the chemical conditions for vaporization by using different CsI + CsOH mixture contents showed that the ionization of the Cs 2 IOH(g) molecule led to five different fragment ions, Cs 2 OH + , Cs 2 I + , Cs + , CsOH + and CsI + . This complex ionization pattern was studied in relation with previous assessed values for the vaporization of CsOH and CsI pure compounds in which monomer and dimer molecules are predominant. The equilibrium constant for the reaction CsI(g) + CsOH(g) = Cs 2 IOH(g) was determined and, after modeling the structure of the Cs 2 IOH molecule, the enthalpy of formation was determined using the third law of thermodynamics, as follows: Δ f H°(Cs 2 IOH, g, 298.15 K) = −578 ± 14.7 kJ · mole −1

Retention of 137Cs in three humans

International Nuclear Information System (INIS)

Soegaard-Hansen, J.; Lauridsen, B.

1992-01-01

In two experiments the retention of 137 Cs after a single intake have been measured with whole-body counting. In the first experiment, two persons ingested a prepared liquid solution of 137 CsCl. In the second experiment these two persons together with a third person ingested 137 Cs naturally incorporated in a piece of meat. The obtained data have been fitted to a retention function with a small compartment having a fast excretion rate and a large compartment having a slow excretion rate, as given by the International Commission on Radiological Protection (ICRP). The effective biological half-lives were in both experiments significantly different from the value given by ICRP. (au)

Cs-137 for irradiation of sewage sludge

International Nuclear Information System (INIS)

Lessel, T.

1986-01-01

Since 1973, the Geiselbullach sewage treatment works have been continuously operating their first system for gamma irradiation of sewage sludge. Within the framework of a German-American agreement, nine Cs-137 sources with a total activity of 56.000 Ci have been made available to the works free of charge in 1983, in order to test in practice and to demonstrate the applicability of these radiation sources in comparison to the Co-60 sources exclusively used up to then. This first study on the applicability of Cs-137 as a radiation source for sewage sludge treatment revealed no findings or effects speaking against Cs-137 as a radiation source for this purpose. (orig./RB) [de

Speciation of 137Cs in the Baltic sea water

International Nuclear Information System (INIS)

Lujaniene, G.; Morkuniene, R.; Styra, D.

1998-01-01

A possibility of application of Filtrac 391 and Nuclepore filters, Ky-2-8-C exchanger and the Mtilon-T fiber impregnated with Fe, Co, Ni ferrocyanides for separation of particulate and ionic 137 Cs in the sea water was investigated. Physico-chemical forms of 137 Cs were investigated in the Baltic Sea water during 1995-1997. It was determined that 137 Cs was mainly present in ionic form (62-93 %) both in the near-shore and open waters. Concentration of particulate 137 Cs ranged from 255 to 625 Bq/kg (dry weight).The distribution coefficient (K d ) of radiocaesium reached values of 2100-9700. (author)

Elastic properties of Cs2HgBr4 and Cs2CdBr4 crystals

International Nuclear Information System (INIS)

Kityk, A.V.; Zadorozhna, A.V.; Shchur, Y.I.; Martynyuk-Lototska, Y.I.; Burak, Y.; Vlokh, O.G.

1998-01-01

Using ultrasonic velocity measurements, all components of the elastic constant matrix C ij , elastic compliances matrix S ij , and linear compressibility constants matrix K ij of orthorhombic Cs 2 HgBr 4 and Cs 2 CdBr 4 crystals have been determined over a wide temperature range, including the region of the phase transition from the normal to the incommensurate phase. Results obtained are considered within the framework of the phenomenological theory. Preliminary analysis of the acoustical properties at room temperature clearly indicates that both crystals are relatively important materials for acousto-optical applications. Copyright (1998) CSIRO Australia

Energy transfer mechanism in CsI:Eu crystal

International Nuclear Information System (INIS)

Yakovlev, V.; Trefilova, L.; Karnaukhova, A.; Ovcharenko, N.

2014-01-01

This paper studies the scintillation process in CsI:Eu crystal exposed to the pulse electron irradiation (E=0.25 MeV, t 1/2 =15 ns and W=0.003 J/cm 2 ). It has been proved that the energy transfer from the lattice to Eu 2+ ions in CsI:Eu occurs through the re-absorption of STE emission. The proposed model rests on the following experimental facts: (1) the activator emission at 2.68 eV rises gradually after the decay of the excitation pulse even at temperature lower than 90 K when V k centers are immobile; (2) the rise time of 2.68 eV emission and the decay time of STE emission have the same temperature dependences at T=78–300 K; (3) the excitation spectrum of 2.68 eV emission overlaps the emission spectrum of STE. -- Highlights: • The scintillation process in CsI:Eu was studied under pulsed electron irradiation. • A model of the energy transfer from the lattice to Eu 2+ ions in CsI:Eu was proposed. • Eu 2+ ions in CsI:Eu reabsorb the π-emission of self-trapped excitons

New crystals of the CsHSO{sub 4}–CsH{sub 2}PO{sub 4}–H{sub 2}O system

Energy Technology Data Exchange (ETDEWEB)

Makarova, I. P., E-mail: makarova@crys.ras.ru; Grebenev, V. V.; Komornikov, V. A.; Selezneva, E. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography, Federal Scientific Research Centre “Crystallography and Photonics,” (Russian Federation)

2016-11-15

Cs{sub 6}H(HSO{sub 4}){sub 3}(H{sub 2}PO{sub 4}){sub 4} crystals, grown for the first time based on an analysis of the phase diagram of the CsHSO{sub 4}–CsH{sub 2}PO{sub 4}–H{sub 2}O ternary system, have been investigated by structural analysis using synchrotron radiation. The atomic structure of the crystals is determined and its specific features are analyzed.

Sorption Analysis of 137Cs On Karawang’s Clay Samples

Directory of Open Access Journals (Sweden)

Budi Setiawan

2016-12-01

Full Text Available The objective of this work is to characterize the specific of distribution coefficient (Kd values of 137Cs onto Karawang’s clay for radioactive waste disposal facility purpose. Sorption phenomena was affected by contact time, ionic strength and loaded concentration of CsCl.  Experiments were done in a batch method, with initial concentration was 10-8 M CsCl in the experiments of contact time and ionic strength effects. In the CsCl loading experiment, the concentration was varied from 10-8 to 10-4 M CsCl and 137Cs radioactive solution was used as a tracer. The solid-liquid ratio is 10-2 g/mL.  The results shown that obtained Kd values were 21,714 and 4035 mL/g after contacted for 8 days for Sample-1 and 2, respectively. The presence of K+ and Na+ ions in solution had reduced the Kd value Cs-137 where the effect of K+ is greater than Na+ on decreased the value of Kd.  The increasing of CsCl concentrations in solution had reduced the value of Kd.  In both samples of clay were closely fit to Freundlich isotherm and pseudo-second order kinetic model.  The results are very useful as the input of the safety assessment activity of site candidate for radioactive waste disposal facility in the future.

A homeostatic-partly dynamic model for 137Cs in trees

International Nuclear Information System (INIS)

Frissel, M.

1994-01-01

A model has been developed to describe the behaviour of 137 Cs in trees. The core of the model is the assumption that 137 Cs/K ratio in soil determines the 137 Cs/K ratio in various parts of a tree. This is an equilibrium model but taking into account the time dependence of Cs/K ratio in the soil (caused by K-fertilization) it has been extended to a dynamic model. The model desribes a growing tree. Four compartments are considered: soil; easily accessible parts of the tree; woody parts difficult to access; fruits or leaves. The model is homeostatic, i.e. all 137 Cs concentrations and fluxes are controlled by K concentrations and fluxes, respectively. The addition of K-fertilizer to the soil manifests itself in an immediate change of the Cs/K ratio in the soil and in the easily accessible plant parts, but only slowly - in the woody parts. Also an excess of Cs in the woody part is only slowly released. Important processes are the discrimination between Cs and K and the luxurious consumption of K. The cycling of K in the system (throughput of K via falling leaves, branches, etc.) is also important. Furthermore, a good insight in accessibility of the various parts of the tree seems required, the division in only three compartments, as in the model is probably unsufficient. (author)

Paddy-field contamination with 134Cs and 137Cs due to Fukushima Dai-ichi Nuclear Power Plant accident and soil-to-rice transfer coefficients

International Nuclear Information System (INIS)

Endo, Satoru; Kajimoto, Tsuyoshi; Shizuma, Kiyoshi

2013-01-01

The transfer coefficient (TF) from soil to rice plants of 134 Cs and 137 Cs in the form of radioactive deposition from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident in March 2011 was investigated in three rice paddy fields in Minami-Soma City. Rice crops were planted in the following May and harvested at the end of September. Soil cores of 30-cm depth were sampled from rice-planted paddy fields to measure 134 Cs and 137 Cs radioactivity at 5-cm intervals. 134 Cs and 137 Cs radioactivity was also measured in rice ears (rice with chaff), straws and roots. The rice ears were subdivided into chaff, brown rice, polished rice and rice bran, and the 134 Cs and 137 Cs radioactivity concentration of each plant part was measured to calculate the respective TF from the soil. The TF of roots was highest at 0.48 ± 0.10 in the field where the 40 K concentration in the soil core was relatively low, in comparison with TF values of 0.31 and 0.38 in other fields. Similar trends could be found for the TF of whole rice plants, excluding roots. The TF of rice ears was relatively low at 0.019–0.026. The TF of chaff, rice bran, brown rice and polished rice was estimated to be 0.049, 0.10–0.16, 0.013–0.017 and 0.005–0.013, respectively. - Highlights: ► We investigated the transfer coefficient of 134 Cs and 137 Cs from soil to rice plants in Minami-Soma City due to the Fukushima accident in 2011. ► The rice ears, straws, roots, chaff, brown rice, polished rice, rice bran and soil samples have been measured by Ge-detector. ► Transfer coefficient of chaff, rice bran, brown rice, and polished rice is estimated as 0.049, ranging from 0.10 to 0.16, 0.013 to 0.017, and 0.005 to 0.013, respectively.

Physicochemical properties of the CsNO2-CsOH-H2O ternary system at 25 deg C

International Nuclear Information System (INIS)

Protsenko, P.I.; Medvedev, B.S.; Popova, T.B.

1977-01-01

Saturated solutions of the CsNO 2 - CsOH- H 2 O system have been studied at 25 deg C by the methods of solubility, viscosity, electric conductivity, refractometry and density. It is stated that no solid phase of a new composition is formed in the system. While adding hydroxide to the saturated solution of cesium nitride, a considerable salting-out of the latter takes place

Water-resistant, monodispersed and stably luminescent CsPbBr3/CsPb2Br5 core-shell-like structure lead halide perovskite nanocrystals

Science.gov (United States)

Qiao, Bo; Song, Pengjie; Cao, Jingyue; Zhao, Suling; Shen, Zhaohui; Gao, Di; Liang, Zhiqin; Xu, Zheng; Song, Dandan; Xu, Xurong

2017-11-01

Lead halide perovskite materials are thriving in optoelectronic applications due to their excellent properties, while their instability due to the fact that they are easily hydrolyzed is still a bottleneck for their potential application. In this work, water-resistant, monodispersed and stably luminescent cesium lead bromine perovskite nanocrystals coated with CsPb2Br5 were obtained using a modified non-stoichiometric solution-phase method. CsPb2Br5 2D layers were coated on the surface of CsPbBr3 nanocrystals and formed a core-shell-like structure in the synthetic processes. The stability of the luminescence of the CsPbBr3 nanocrystals in water and ethanol atmosphere was greatly enhanced by the photoluminescence-inactive CsPb2Br5 coating with a wide bandgap. The water-stable enhanced nanocrystals are suitable for long-term stable optoelectronic applications in the atmosphere.

Star-forming galaxy models: Blending star formation into TREESPH

Science.gov (United States)

Mihos, J. Christopher; Hernquist, Lars

1994-01-01

We have incorporated star-formation algorithms into a hybrid N-body/smoothed particle hydrodynamics code (TREESPH) in order to describe the star forming properties of disk galaxies over timescales of a few billion years. The models employ a Schmidt law of index n approximately 1.5 to calculate star-formation rates, and explicitly include the energy and metallicity feedback into the Interstellar Medium (ISM). Modeling the newly formed stellar population is achieved through the use of hybrid SPH/young star particles which gradually convert from gaseous to collisionless particles, avoiding the computational difficulties involved in creating new particles. The models are shown to reproduce well the star-forming properties of disk galaxies, such as the morphology, rate of star formation, and evolution of the global star-formation rate and disk gas content. As an example of the technique, we model an encounter between a disk galaxy and a small companion which gives rise to a ring galaxy reminiscent of the Cartwheel (AM 0035-35). The primary galaxy in this encounter experiences two phases of star forming activity: an initial period during the expansion of the ring, and a delayed phase as shocked material in the ring falls back into the central regions.

EMACSS: Evolve Me A Cluster of StarS

Science.gov (United States)

Alexander, Poul E. R.; Gieles, Mark

2012-03-01

The star cluster evolution code Evolve Me A Cluster of StarS (EMACSS) is a simple yet physically motivated computational model that describes the evolution of some fundamental properties of star clusters in static tidal fields. The prescription is based upon the flow of energy within the cluster, which is a constant fraction of the total energy per half-mass relaxation time. According to Henon's predictions, this flow is independent of the precise mechanisms for energy production within the core, and therefore does not require a complete description of the many-body interactions therein. Dynamical theory and analytic descriptions of escape mechanisms is used to construct a series of coupled differential equations expressing the time evolution of cluster mass and radius for a cluster of equal-mass stars. These equations are numerically solved using a fourth-order Runge-Kutta integration kernel; the results were benchmarked against a data base of direct N-body simulations. EMACSS is publicly available and reproduces the N-body results to within 10 per cent accuracy for the entire post-collapse evolution of star clusters.

Crystal Growth and Scintillation Properties of Eu2+ doped Cs4CaI6 and Cs4SrI6

Science.gov (United States)

Stand, L.; Zhuravleva, M.; Chakoumakos, B.; Johnson, J.; Loyd, M.; Wu, Y.; Koschan, M.; Melcher, C. L.

2018-03-01

In this work we present the crystal growth and scintillation properties of two new ternarymetal halide scintillators activated with divalent europium, Cs4CaI6 and Cs4SrI6. Single crystals of each compound were grown in evacuated quartz ampoules via the vertical Bridgman technique using a two-zone transparent furnace. Single crystal X-ray diffraction experiments showed that both crystals have a trigonal (R-3c) structure, with a density of 3.99 g/cm3 and 4.03 g/cm3. The radioluminescence and photoluminescence measurements showed typical luminescence properties due to the 5d-4f radiative transitions in Eu2+. At this early stage of development Cs4SrI6:Eu and Cs4CaI6:Eu have shown very promising scintillation properties, with light yields and energy resolutions of 62,300 ph/MeV and 3.3%, and 51,800 photons/MeV and 3.6% at 662 keV, respectively.

{sup 137}Cs applicability to soil erosion assessment: theoretical and empirical model; Aplicabilidade do {sup 137}Cs para medir erosao do solo: modelos teoricos e empiricos

Energy Technology Data Exchange (ETDEWEB)

Andrello, Avacir Casanova

2004-02-15

The soil erosion processes acceleration and the increase of soil erosion rates due to anthropogenic perturbation in soil-weather-vegetation equilibrium has influenced in the soil quality and environment. So, the possibility to assess the amplitude and severity of soil erosion impact on the productivity and quality of soil is important so local scale as regional and global scale. Several models have been developed to assess the soil erosion so qualitative as quantitatively. {sup 137}Cs, an anthropogenic radionuclide, have been very used to assess the superficial soil erosion process Empirical and theoretical models were developed on the basis of {sup 137} Cs redistribution as indicative of soil movement by erosive process These models incorporate many parameters that can influence in the soil erosion rates quantification by {sup 137} Cs redistribution. Statistical analysis was realized on the models recommended by IAEA to determinate the influence that each parameter generates in results of the soil redistribution. It was verified that the most important parameter is the {sup 137} Cs redistribution, indicating the necessity of a good determination in the {sup 137} Cs inventory values with a minimum deviation associated with these values. After this, it was associated a 10% deviation in the reference value of {sup 137} Cs inventory and the 5% in the {sup 137} Cs inventory of the sample and was determinate the deviation in results of the soil redistribution calculated by models. The results of soil redistribution was compared to verify if there was difference between the models, but there was not difference in the results determinate by models, unless above 70% of {sup 137} Cs loss. Analyzing three native forests and an area of the undisturbed pasture in the Londrina region, can be verified that the {sup 137} Cs spatial variability in local scale was 15%. Comparing the {sup 137} Cs inventory values determinate in the three native forest with the {sup 137} Cs inventory

Transfer of 137Cs through the food chain to man

International Nuclear Information System (INIS)

Evans, C.; Bennett, B.G.

1976-10-01

Deposition, concentrations in diet, and body burdens of 137 Cs have been measured since 1954 at various sites throughout the world. This report is a compilation and updating of various fallout 137 Cs measurements and an interpretation of transfer properties of 137 Cs from deposition to diet and from diet to man. An empirical model is used to correlate deposition and diet data. Direct foliar contamination, stored food supplies, and uptake from soil contribute to the dietary levels of 137 Cs. The accumulation of 137 Cs by man is described by a single exponential model. The inferred biological half-times, 200 to 400 days, are somewhat greater than the half-time of about 100 days obtained from shorter term studies. Differences in body burdens due to sex, age, and weight are discussed. During the period 1954 to 1974, the internal dose from fallout 137 Cs, based on average body burdens, is estimated to be 4 to 5 percent of the 21 year radiation dose from 40 K

Shape and phase evolution from CsPbBr3 perovskite nanocubes to tetragonal CsPb2Br5 nanosheets with an indirect bandgap.

Science.gov (United States)

Li, Guopeng; Wang, Hui; Zhu, Zhifeng; Chang, Yajing; Zhang, Ting; Song, Zihang; Jiang, Yang

2016-09-13

Tetragonal CsPb 2 Br 5 nanosheets were obtained by an oriented attachment of orthorhombic CsPbBr 3 nanocubes, involving a lateral shape evolution from octagonal to square. Meanwhile, the experimental results, together with DFT simulation results, indicated that the tetragonal CsPb 2 Br 5 is an indirect bandgap semiconductor that is PL-inactive with a bandgap of 2.979 eV.

Radioecological studies of 137Cs in limnological ecosystems. 137Cs concentrations in water, sediment and biota at the lower region of the famous river in Saitama Prefecture

International Nuclear Information System (INIS)

Miyake, Sadaaki; Motegi, Misako; Oosawa, Takashi; Nakazawa, Kiyoaki; Ogata, Hiromitsu; Izumo, Yoshiro; Nakamura, Fumio.

1996-01-01

The concentrations of 137 Cs in water, sediment and biota at the lower region of the famous river in Saitama prefecture were determined in order to elucidate the radioecology of 137 Cs in limnological ecosystems. 137 Cs concentration in water was 0.10 mBq/l. 137 Cs concentrations in sediment, shellfish, Sinotaia quadratus historica (mean for 2 detectable samples), and fish, Carassius auratus cuvieri (mean for 2 detectable samples), were about 6200, 840 and 320 times higher than the concentration of the water, respectively. But 137 Cs radioactivity in the crustacea, Procambarus clarki, was significantly not detected. So, 137 Cs transfer mechanism in the limnological ecosystems was indicated in part. (author)

CS Bond formation by

Indian Academy of Sciences (India)

2017-02-02

Feb 2, 2017 ... a thiol substituent at position-2 of the quinazoline ring. ... coupling reactions represent great contribution to the recent growth of organic synthesis.2 ... Difficulties in C-S ...... Experimental Advances (Amsterdam: Elsevier) 19; (b).

Cucumber Metallothionein-Like 2 (CsMTL2 Exhibits Metal-Binding Properties

Directory of Open Access Journals (Sweden)

Yu Pan

2016-11-01

Full Text Available We identified a novel member of the metallothionein (MT family, Cucumis sativus metallothionein-like 2 (CsMTL2, by screening a young cucumber fruit complementary DNA (cDNA library. The CsMTL2 encodes a putative 77-amino acid Class II MT protein that contains two cysteine (Cys-rich domains separated by a Cys-free spacer region. We found that CsMTL2 expression was regulated by metal stress and was specifically induced by Cd2+ treatment. We investigated the metal-binding characteristics of CsMTL2 and its possible role in the homeostasis and/or detoxification of metals by heterologous overexpression in Escherichia coli cells. Furthermore, we produced a deletion mutant form of the protein, CsMTL2m, that contained the two Cys-rich clusters but lacked the spacer region, in E. coli. We compared the metal-binding properties of CsMTL2 with those of CsMTL2m, the β domain of human metallothionein-like protein 1 (HsMTXb, and phytochelatin-like (PCL heterologously expressed in E. coli using metal-binding assays. We found that E. coli cells expressing CsMTL2 accumulated the highest levels of Zn2+ and Cd2+ of the four transformed cell types, with levels being significantly higher than those of control cells containing empty vector. E. coli cells expressing CsMTL2 had a higher tolerance for cadmium than for zinc ions. These findings show that CsMTL2 improves metal tolerance when heterologously expressed in E. coli. Future studies should examine whether CsMTL2 improves metal tolerance in planta.

Reversible light-mediated compositional and structural transitions between CsPbBr3 and CsPb2Br5 nanosheets.

Science.gov (United States)

Shen, Wei; Ruan, Longfei; Shen, Zhitao; Deng, Zhengtao

2018-03-13

This communication describes a new method to achieve reversible light-induced chemical composition and phase structural transitions from polyvinylpyrrolidone-capped orthorhombic CsPbBr 3 to tetragonal CsPb 2 Br 5 nanosheets or vice versa. This work will deepen our understanding of the controlled synthesis, post-processing, and decomposition pathway of cesium lead halide perovskite nanocrystals.

White polymer light-emitting diodes based on star-shaped polymers with an orange dendritic phosphorescent core.

Science.gov (United States)

Zhu, Minrong; Li, Yanhu; Cao, Xiaosong; Jiang, Bei; Wu, Hongbin; Qin, Jingui; Cao, Yong; Yang, Chuluo

2014-12-01

A series of new star-shaped polymers with a triphenylamine-based iridium(III) dendritic complex as the orange-emitting core and poly(9,9-dihexylfluorene) (PFH) chains as the blue-emitting arms is developed towards white polymer light-emitting diodes (WPLEDs). By fine-tuning the content of the orange phosphor, partial energy transfer and charge trapping from the blue backbone to the orange core is realized to achieve white light emission. Single-layer WPLEDs with the configuration of ITO (indium-tin oxide)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/polymer/CsF/Al exhibit a maximum current efficiency of 1.69 cd A(-1) and CIE coordinates of (0.35, 0.33), which is very close to the pure white-light point of (0.33, 0.33). To the best of our knowledge, this is the first report on star-shaped white-emitting single polymers that simultaneously consist of fluorescent and phosphorescent species. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Barium and Tc-poor S stars: Binary masqueraders among carbon stars

OpenAIRE

Jorissen, A.; Van Eck, S.

1997-01-01

The current understanding of the origin of barium and S stars is reviewed, based on new orbital elements and binary frequencies. The following questions are addressed: (i) Is binarity a necessary condition to produce a barium star? (ii) What is the mass transfer mode (wind accretion or RLOF?) responsible for their formation? (iii) Do barium stars form as dwarfs or as giants? (iv) Do barium stars evolve into Tc-poor S stars? (v) What is the relative frequency of Tc-rich and Tc-poor S stars?

Contribution of Asian dust to atmospheric deposition of radioactive cesium (137Cs)

International Nuclear Information System (INIS)

Fukuyama, Taijiro; Fujiwara, Hideshi

2008-01-01

Both Asian dust (kosa) transported from the East Asian continent and locally suspended dust near monitoring sites contribute to the observed atmospheric deposition of 137 Cs in Japan. To estimate the relative contribution of these dust phenomena to the total 137 Cs deposition, we monitored weekly deposition of mineral particles and 137 Cs in spring. Deposition of 137 Cs from a single Asian dust event was 62.3 mBq m -2 and accounted for 67% of the total 137 Cs deposition during the entire monitoring period. Furthermore, we found high 137 Cs specific activity in the Asian dust deposition sample. Although local dust events contributed to 137 Cs deposition, their contribution was considerably smaller than that of Asian dust. We conclude that the primary source of atmospheric 137 Cs in Japan is dust transported from the East Asian continent

Mastering Adobe Premiere Pro CS6

CERN Document Server

Ekert, Paul

2013-01-01

Designed to be practical and engaging, Mastering Adobe Premiere Pro CS6 is a project-based book to help you truly augment your skills and become a film editing hotshot.If you're just starting out or even migrating from existing video editing software, then this book is for you. With rapid progression through practical examples constructed to be both engaging and useful, Mastering Adobe Premiere Pro CS6 is ideal for learning the sometimes complex workflows of this powerful application.

{sup 137}CS-determination in game meat from some hunting areas in lower Austria; {sup 137}Cs-Bestimmungen im Wildfleisch aus einigen niederoesterreichischen Jagdrevieren

Energy Technology Data Exchange (ETDEWEB)

Ayromlou, S. [Inst. fuer Anorganische Chemie der Univ. Wien (Austria); Tataruch, F. [Forschungsinstitut fuer Wildtierkunde und Oekologie der Veterinaermedizinischen Univ., Wien (Austria)

2001-07-01

In 1986, the contamination of some regions in Austria by {sup 137}Cs, due to the Chernobyl accident was relatively high. Among other {sup 137}Cs is taken up by people by the consumption of game. In an area of Lower Austria which is relatively heavily contaminated by Chernobyl fallout since 1986 the {sup 137}Cs-contamination of meat of game-animals was measured every year. Clear differences arose in the load of the single game species whose causes just like the temporal changes are discussed. The highest {sup 137}Cs activity concentration was with 5243 Bq/kg measured on a wild boar. With this activity concentration an annual effective dose of only 0,06 mSv can be estimated for an annual average consumption of one kilogram meat of wild boar. (orig.) [German] Druch den Reaktor-Unfall in Tschernobyl wurde Oesterreich gebietsweise relativ stark mit {sup 137}Cs kontaminiert. Unter anderem gelangt {sup 137}Cs durch den Verzehr von Wildfleisch in den Koerper der Menschen. Daher wurden in einem niederoesterreichischen Gebiet, das 1986 durch Fallout verhaeltnismaessig stark kontaminiert worden war seither jaehrlich erlegte Wildtiere auf den {sup 137}Cs-Gehalt ihres Fleisches hin untersucht. Dabei ergaben sich deutliche Unterschiede in der Belastung der einzelnen Wildarten, deren Ursachen ebenso wie die zeitlichen Veraenderungen diskutiert werden. Die hoechste {sup 137}Cs-Aktivitaetskonzentration wurde mit 5243 Bq/kg bei einem Wildschwein gemessen. Mit einen durchschnittlichen Verzehr von 1 kg Wildschweinfleisch pro Jahr kann daraus eine maximale Effektivdosis von nur 0,06 mSv/Jahr abgeschaetzt werden. (orig.)

Radio stars

International Nuclear Information System (INIS)

Hjellming, R.M.

1976-01-01

Any discussion of the radio emission from stars should begin by emphasizing certain unique problems. First of all, one must clarify a semantic confusion introduced into radio astronomy in the late 1950's when most new radio sources were described as radio stars. All of these early 'radio stars' were eventually identified with other galactic and extra-galactic objects. The study of true radio stars, where the radio emission is produced in the atmosphere of a star, began only in the 1960's. Most of the work on the subject has, in fact, been carried out in only the last few years. Because the real information about radio stars is quite new, it is not surprising that major aspects of the subject are not at all understood. For this reason this paper is organized mainly around three questions: what is the available observational information; what physical processes seem to be involved; and what working hypotheses look potentially fruitful. (Auth.)

TURBOVELOCITY STARS: KICKS RESULTING FROM THE TIDAL DISRUPTION OF SOLITARY STARS

International Nuclear Information System (INIS)

Manukian, Haik; Guillochon, James; Ramirez-Ruiz, Enrico; O'Leary, Ryan M.

2013-01-01

The centers of most known galaxies host supermassive black holes (SMBHs). In orbit around these black holes are a centrally concentrated distribution of stars, both in single and in binary systems. Occasionally, these stars are perturbed onto orbits that bring them close to the SMBH. If the star is in a binary system, the three-body interaction with the SMBH can lead to large changes in orbital energy, depositing one of the two stars on a tightly-bound orbit, and its companion into a hyperbolic orbit that may escape the galaxy. In this Letter, we show that the disruption of solitary stars can also lead to large positive increases in orbital energy. The kick velocity depends on the amount of mass the star loses at pericenter, but not on the ratio of black hole to stellar mass, and are at most the star's own escape velocity. We find that these kicks are usually too small to result in the ejection of stars from the Milky Way, but can eject the stars from the black hole's sphere of influence, reducing their probability of being disrupted again. We estimate that ∼ 10 5 stars, ∼ 1% of all stars within 10 pc of the galactic center, are likely to have had mass removed by the central black hole through tidal interaction, and speculate that these 'turbovelocity' stars will at first be redder, but eventually bluer, and always brighter than their unharassed peers.

First-order phase transitions in a quantum Hall ferromagnet

Czech Academy of Sciences Publication Activity Database

Piazza, V.; Pellegrini, V.; Beltram, F.; Wegscheider, W.; Jungwirth, Tomáš; MacDonald, A.

1999-01-01

Roč. 402, č. 9 (1999), s. 638-641 ISSN 0028-0836 R&D Projects: GA AV ČR KSK1010601 Institutional research plan: CEZ:AV0Z1010914 Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 29.491, year: 1999

Relationship between 137Cs concentration and cultivated history on loessial hillslopes

International Nuclear Information System (INIS)

Wang Xiaoyan; Tian Junliang; Yang Mingyi; Liu Puling

2005-01-01

There are close linkages between soil loss degree and soil disturbance degree by human. So it is a key problem to know that how human activity affects soil loss. To analyse the correlation of 137 Cs loss degree with hillslopes' cultivated histories, the concentrations of 137 Cs on different kinds of loessial hillslopes with different cultivated histories, abandoned ages and different patterns of reforestation are studied. The result shows that there is a linear relationship among 137 Cs areal concentrations, cultivation ages and slope gradients. the regressive equation is as follows: X=2356.79-22.77 t-35.53 S. Variant coefficient of 137 Cs areal concentration is 80.11% among hillslopes with different abandonment ages. It is also deduced that 137 Cs areal concentration is affected primarily by abandonment ages of hillslopes. The 137 Cs loss rates of hillslopes with different vegetation restoration manners show significant differences, as a whole, autogenic restoration 137 Cs area concentrations on hillslopes. (authors)

Internal contamination assessment, with regard to 90Sr, 134Cs, and 137Cs nuclei during nuclear accident

International Nuclear Information System (INIS)

Ayad, M.; Hanna, K.M.

2000-01-01

In case of nuclear reactor accident leading to the release of some radioactive isotopes in the plume, the sedimentation of its constituents on the ground causes surface contamination which consequently can be observed in the form of an internal contamination in the living biosphere. The migration of the radio nuclei from the soil to the plant root, stem, and the other edible parts is considered the main source for the contaminated foodstuffs used by the general public. In this work we have calculated the total accumulative internal dose for 9 0Sr, 1 34Cs, and 1 37Cs radio contaminants with regard to different public age groups (infant, child, and adult) due to an unexpected nuclear accident. In our calculations we have applied the protective measure inequality for the chosen standard group of foodstuffs, with respect to each age group of the public as well as the three indicated above radio nuclei. Our results indicated that the values of the calculated protective measures with regard to 9 0Sr, 1 37Cs, and 1 34Cs radio nuclei are increasing respectively for all age groups. In addition, we found that the ratio of the total protection measure values of all radio nuclei for different age groups still less than one which requires no intervention level procedures

Direct and indirect contamination of tree crops with Cs-134

International Nuclear Information System (INIS)

Skarlou, V.; Nobeli, C.; Anoussis, J.; Arapis, G.; Haidouti, C.

1996-01-01

A long term glasshouse pot experiment was established in 1994 to study the transfer factors of Cs-134 from soil to olive and orange trees for which no relevant data are available. A calcareous-heavy textured and an acid-light textured soil were used in this experiment. Results from two year's experimentation are considered in this study. The ability of the studied plant species for Cs-134 root uptake seems to be significantly influenced by soil type. The contamination of both tree species grown on calcareous and heavy soil was very low and did not change much with the time. On the contrary, trees grown on acid and light soil showed much higher Cs-134 concentration (up to 34 times for orange and 23 for olive trees) which significantly increased with the time. Both olive and orange trees showed a similar behaviour in the studied soils. Effort was also made to study the long term consequences of the direct contamination in a field experiment where an olive tree was contaminated by dry deposition with Cs-134. Six months after contamination 5 % of the Cs-134 deposited on the leaves was measured in the first olive production. However, very small quantities (= 0.5 %) of the olive Cs-134 was detected in the unprocessed olive oil. The following year 15 % of the Cs-134 remained in the leaves while extremely low quantities of Cs-134 were detected in either olives or olive oil. (author)

Changes in 137Cs transfer to agricultural products

International Nuclear Information System (INIS)

Goncharov, N.; Timochtchenko, A.; Milutin, A.

1999-01-01

The food production and food harvesting systems common in the areas contaminated by the Chernobyl accident in Republic of Belarus can be grouped into three major categories: collective farm produce, private farming produce and natural foods collected from natural ecosystems. The collective farm system provided the smallest contribution (8-12 %) to the intake of 137 Cs. Natural food was the major contributor to the intake at one study site (73 %), and private produce was the major contributor (60 %) at the other study site. Assessment of the situation just after the accident (one year) shows that collective farming was still a minor contributor to 137 CS intake (10 %) whilst private fanning would have been the major contributor wherever private milk production and consumption continued. The extent to which inhabitants consume natural foods from forests has a considerable effect on their 137 CS intake. The comparative importance of food products from natural ecosystems increases with time due to the long effective ecological half lives of 137 Cs in unimproved pastures and forests. Estimation of the contribution to the fluxes of 137 Cs from the different production and harvesting systems showed that the contribution from private farming and food harvesting from natural ecosystems may also be significant, contributing 14-30 % to the total fluxes of 137 Cs from an area even if the quantity of food produced in these systems is small. However, the major contributor to the flux exported from an area was the collective farming system, accounting for about 70-86 % of the total. Refs. 12 (author)

Kinetics of Cs adsorption on soils with different mineralogical composition

International Nuclear Information System (INIS)

Nakao, Atsushi; Funakawa, Shinya; Kosaki, Takashi

2004-01-01

137 Cs is one of the main radioisotopes released into the environment by nuclear powerstation accidents (e.g. Chernobyl) and nuclear weapons tests. Many studies have shown that Cs tends to remain at surface soils due to the high adsorption selectivity of clay minerals for this element. This behavior of the Cs + ion is, however, assumed to vary significantly depending on the mineralogical composition of the soil. The main objective of this study is to analyze the kinetics of Cs adsorption on soils with different mineralogical composition. Soil samples used in this study were Mollisols (Um) and Alfisols (Ua) from Ukraine, Ultisols (Tu) from Thailand and Spodosols (Js) from Japan. The dominant clay species of these soils are montmorillonite (Um, Ua), kaolinite and mica (Tu) and beidellite (Js). The rates of Cs adsorption and Ca or K desorption were measured using a continuous flow method. Soil samples that were previously saturated with Ca 2+ were leached with a 0.75 mmol/l Cs + solution at a constant rate of 2.0 ml/min. The leachate was collected every 10 minutes and the concentrations of Cs + , Ca 2+ and K + of each aliquot were measured by atomic adsorption spectrophotometry (Cs + , Ca 2+ ) and flame spectrophotometry (K + ). The datasets obtained were simulated using the first order kinetic model: y = a(1 - exp(-kt)), where a is the adsorption (desorption) maximum and k the rate constant. It is here assumed that Ca 2+ is desorbed from cation exchange sites and K + desorbed from the frayed edges of micaceous minerals. The values of a obtained for both Cs adsorption and Ca desorption was in the order Js>Um>Tu>Ua, whereas the values of k were in the order Tu>Ua>Um>Js. This result reflects the values of permanent negative charge of clays which are originated from the substitution of cations in the structure of 2:1 clay minerals. The value of a for K + desorption was, however, highest in Tu, suggesting that the values of Cs + -exchangeable K + correspond to the amount

Radio stars

International Nuclear Information System (INIS)

Hjellming, R.M.; Gibson, D.M.

1985-01-01

Studies of stellar radio emission became an important field of research in the 1970's and have now expanded to become a major area of radio astronomy with the advent of new instruments such as the Very Large Array in New Mexico and transcontinental telescope arrays. This volume contains papers from the workshop on stellar continuum radio astronomy held in Boulder, Colorado, and is the first book on the rapidly expanding field of radio emission from stars and stellar systems. Subjects covered include the observational and theoretical aspects of stellar winds from both hot and cool stars, radio flares from active double star systems and red dwarf stars, bipolar flows from star-forming regions, and the radio emission from X-ray binaries. (orig.)

Transformation of Cs-IONSIV® into a ceramic wasteform by hot isostatic pressing

Science.gov (United States)

Chen, Tzu-Yu; Maddrell, Ewan R.; Hyatt, Neil C.; Gandy, Amy S.; Stennett, Martin C.; Hriljac, Joseph A.

2018-01-01

A simple method to directly convert Cs-exchanged IONSIV® IE-911 into a ceramic wasteform by hot isostatic pressing (1100 °C/190 MPa/2 hr) is presented. Two major Cs-containing phases, Cs2TiNb6O18 and Cs2ZrSi6O15, and a series of mixed oxides form. The microstructure and phase assemblage of the samples as a function of Cs content were examined using XRD, XRF, SEM and TEM/EDX. The chemical aqueous durability of the materials was investigated using the MCC-1 and PCT-B standard test methods. For HIPed Cs-IONSIV® samples, the MCC-1 normalised release rates of Cs were low rates are indicative of a safe long-term immobilisation matrix for Cs formed directly from spent IONSIV®. It was also demonstrated that the phase formation can be altered by adding Ti metal due to a controlled redox environment.

Effect of 137Cs on immunological reactivity

International Nuclear Information System (INIS)

Shubik, V.M.

1975-01-01

An important role of 137 Cs as a new ecological factor was shown by analyzing 31 different studies. The radioisotope may at present be detected in the organisms of all inhabitants of this planet. The migration of 137 Cs along the chain lichen-deer-man leads to its accumulation in the organism of humans living in the Extreme North and taking venison in their food. Although the high sensitivity of immunological reactions to various unfavourable environmental factors is well known, data on the effect of incorporated 137 Cs on immunity are scanty. Experiments on animals showed changes in factors of nonspecific immunity (phagocytic reaction of blood neutrophils, bactericidal activity, lysozyme and complement titres of blood serum) and specific immunity (formation of antiviral antibodies). The blood of animals injured by the isotope displays complete and incomplete autoantibodies. The dependence of immunobiological changes on the dose absorbed by the organism is shown. The 137 Cs intake of inhabitants of the Extreme North who eat venison did not, with the absorbed dose equalling up to 50 Mrem per year, lead to changes in their immunological reactivity. (author)

Effective half-lives of 137Cs in giant butterbur and field horsetail, and the distribution differences of potassium and 137Cs in aboveground tissue parts

International Nuclear Information System (INIS)

Tagami, Keiko; Uchida, Shigeo

2015-01-01

Concentrations of 137 Cs and 40 K in different tissues of edible wild herbaceous plants, that is, leaf blade and petiole for giant butterbur (Petasites japonicas (Siebold et Zucc.) Maxim.), and leaf, stem and strobilus for fertile shoot of field horsetail (Equisetum arvense L.) were measured in 2012–2014 to clarify the effect in Japan from the Fukushima Daiichi Nuclear Power Plant accident. The concentrations of 137 Cs decreased with time with effective half-lives of ca. 450 d and 360 d for giant butterbur and field horsetail, respectively. The ANOVA test revealed that 40 K and 137 Cs distributions in leaf blade and petiole for giant butterbur and leaf and stem for field horsetail were different. Therefore, other plants, leaf and stem for Japanese knotweed (Fallopia japonica (Houtt.) Ronse Decr.) and Canada goldenrod (Solidago canadensis L.), and leaf blade and petiole for gingko (Ginkgo biloba L.) and Someiyoshino cherry (Cerasus × yedoensis (Matsum.) A.V.Vassil. ‘Somei-yoshino’) were collected from the same sampling field and their 137 Cs and 40 K concentrations were compared to those in the giant butterbur and field horsetail parts. For 137 Cs, concentrations in leaf blade and leaf parts were 1.1–6.0 times higher than those in petiole and stem parts for all six plants. On the other hand, 40 K concentrations in leaf blade and leaf parts were 0.40–0.97 of those observed in petiole and stem parts. Discrimination ratios of 40 K/ 137 Cs of leaf blade to petiole or leaf to stem were then calculated and they ranged from 0.09 to 0.57. These results suggested that Cs and K did not behave similarly in these plants. Thus, to understand the radiocesium fate in plants, K measurement results should not be used as an analog for Cs behavior although Cs is known to have a similar chemical reactivity to that of K. - Highlights: • 137 Cs amounts in leaf blade and leaf were higher than those in petiole and stem in plants. • 40 K amounts in leaf blade and leaf

Plant remediation of soil contaminated with 137Cs

International Nuclear Information System (INIS)

Yang Juncheng; Zhang Jianfeng; Zhu Yongyi; Chen Jingjie; Mei Yong; Jiang Huimin

2005-01-01

A pot experiment was conducted to evaluate the bio-remediation of soils contaminated with 137 Cs. The selected plants are Cucurbita moschata Duchesne, Brassica chinensis L, Chloris virgata, Beta oulgaris L. Hongye, Beta oulgaris L. Dongshengye and Beta oulgaris L. The soils samples were taken from the paddy field, 2 km from the Dayawan nuclear power plant and Qinshan nuclear power plant, respectively, and cinnamon soil from the cultivated land in Beijing. The results show that all the employed species of plant have a higher accumulation to 137 Cs with the increased grade of the radioactivity of 137 Cs. A good correlation exist with the coefficient (r 2 ) of 0.9989. When the contaminated radioactivity of 137 Cs is in the same level the uptake of Cucurbita moschata Duchesne, Brassica chinensis L. and Chloris virgata increased with the decrease of pH value ranged 5.22-7.69. The ability of bioremediation in the orders were Chloris virgata, Brassica chinensis L., Beta oulgaris L. Hongye, Cucurbita moschata Duchesne, Beta oulgaris L. and Beta oulgaris L. Dongshengye, according to the comprehensive evaluation of transfer factor, specific activity of plant in dry weight of biomass and total absorption of 137 Cs by the individual plant in the same area. (authors)

Inferring the chemical form of 137Cs deposited by the Fukushima Dai-ichi Nuclear Power Plant accident by measuring (137)Cs incorporated into needle leaves and male cones of Japanese cedar trees.

Science.gov (United States)

Kanasashi, Tsutomu; Takenaka, Chisato; Sugiura, Yuki

2016-05-15

We hypothesized that the water-soluble (ionic) and water-insoluble (stable) radiocesium from the initial fallout of the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident was distributed in various proportions in the surrounding areas and that this distribution was reflected in the trees that suffered deposition from the initial fallout. This study attempted to evaluate local variations in the chemical form of (137)Cs derived from the initial fallout of the FDNPP accident and whether its chemical form affected the radiocesium concentration in the tissues currently growing in trees, even after the initial fallout ceased. For these estimations, the ratio between the (137)Cs concentration in Cryptomeria japonica needle leaves in the tree crown, which existed before the FDNPP accident and subsequently directly exposed to the initial fallout ((137)Cs pre-accident N), and the amount of (137)Cs in the initial fallout itself ((137)Cs fallout) was determined ((137)Cs pre-accident N/(137)Cs fallout) at 66 sites. In addition, the (137)Cs ratios between the male cones produced in 2012 ((137)Cs male cone) and needle leaves that had elongated in the spring of 2011 ((137)Cs 2011N) was determined at 82 sites ((137)Cs male cone/(137) Cs 2011N). Most of the sites with lower (137)Cs pre-accident N /(137)Cs fallout ratios were distributed in eastern Fukushima, relatively close to the Pacific Ocean coastline. Lower (137)Cs pre-accident N/(137)Cs fallout and higher (137)Cs malecone/(137)Cs 2011N were found to be associated with higher proportions of (137)Cs in ionic forms. These observations are consistent with the hypothesis, and likely reflect regional variations in the chemical form of the deposited radiocesium. Copyright © 2016 Elsevier B.V. All rights reserved.

Facile synthesis of CsPbBr3/PbSe composite clusters

OpenAIRE

Nguyen, Thang Phan; Ozturk, Abdullah; Park, Jongee; Sohn, Woonbae; Lee, Tae Hyung; Jang, Ho Won; Kim, Soo Young

2017-01-01

Abstract In this work, CsPbBr3 and PbSe nanocomposites were synthesized to protect perovskite material from self-enlargement during reaction. UV absorption and photoluminescence (PL) spectra indicate that the addition of Se into CsPbBr3 quantum dots modified the electronic structure of CsPbBr3, increasing the band gap from 2.38 to 2.48 eV as the Cs:Se ratio increased to 1:3. Thus, the emission color of CsPbBr3 perovskite quantum dots was modified from green to blue by increasing the Se ratio ...

A hybrid method for accurate star tracking using star sensor and gyros.

Science.gov (United States)

Lu, Jiazhen; Yang, Lie; Zhang, Hao

2017-10-01

Star tracking is the primary operating mode of star sensors. To improve tracking accuracy and efficiency, a hybrid method using a star sensor and gyroscopes is proposed in this study. In this method, the dynamic conditions of an aircraft are determined first by the estimated angular acceleration. Under low dynamic conditions, the star sensor is used to measure the star vector and the vector difference method is adopted to estimate the current angular velocity. Under high dynamic conditions, the angular velocity is obtained by the calibrated gyros. The star position is predicted based on the estimated angular velocity and calibrated gyros using the star vector measurements. The results of the semi-physical experiment show that this hybrid method is accurate and feasible. In contrast with the star vector difference and gyro-assisted methods, the star position prediction result of the hybrid method is verified to be more accurate in two different cases under the given random noise of the star centroid.

Star Products and Applications

OpenAIRE

Iida, Mari; Yoshioka, Akira

2010-01-01

Star products parametrized by complex matrices are defined. Especially commutative associative star products are treated, and star exponentials with respect to these star products are considered. Jacobi's theta functions are given as infinite sums of star exponentials. As application, several concrete identities are obtained by properties of the star exponentials.

Effective star tracking method based on optical flow analysis for star trackers.

Science.gov (United States)

Sun, Ting; Xing, Fei; Wang, Xiaochu; Li, Jin; Wei, Minsong; You, Zheng

2016-12-20

Benefiting from rapid development of imaging sensor technology, modern optical technology, and a high-speed computing chip, the star tracker's accuracy, dynamic performance, and update rate have been greatly improved with low power consumption and miniature size. The star tracker is currently one of the most competitive attitude measurement sensors. However, due to restrictions of the optical imaging system, difficulties still exist in moving star spot detection and star tracking when in special motion conditions. An effective star tracking method based on optical flow analysis for star trackers is proposed in this paper. Spot-based optical flow, based on a gray gradient between two adjacent star images, is analyzed to distinguish the star spot region and obtain an accurate star spot position so that the star tracking can keep continuous under high dynamic conditions. The obtained star vectors and extended Kalman filter (EKF) are then combined to conduct an angular velocity estimation to ensure region prediction of the star spot; this can be combined with the optical flow analysis result. Experiment results show that the method proposed in this paper has advantages in conditions of large angular velocity and large angular acceleration, despite the presence of noise. Higher functional density and better performance can be achieved; thus, the star tracker can be more widely applied in small satellites, remote sensing, and other complex space missions.

Rietveld refinement of the orthorhombic Pbca structures of Rb2CdSi5O12, Cs2MnSiO5O12, Cs2CoSi5O12 and Cs2NiSi5O12 leucites by synchrotron X-ray powder diffraction

International Nuclear Information System (INIS)

Bell, A.M.T.; Henderson, C.M.B.

1996-01-01

Analysis of high-resolution synchrotron X-ray powder diffraction patterns for hydrothermally synthesized Rb 2 CdSi 5 O 12 and Cs 2 MnSi 5 O 12 leucite analogues, and dry-synthesized Cs 2 CoSi 5 O 12 and Cs 2 NiSi 5 O 12 leucite analogues showed that they have an orthorhombic Pbca structure. The structures have been refined by the Rietveld method, showing that the tetrahedrally coordinated atoms (Si, Cd, Mn, Co and Ni) are ordered on separate sites. The Cs 2 MnSi 5 O 12 , Cs 2 CoSi 5 O 12 and Cs 2 NiSi 5 O 12 leucite samples are unusual in containing SiO 4 tetrahedra which are more distorted, on average, than the larger MnO 4 , CoO 4 and NiO 4 tetrahedra. The JCPDS file numbers for Rb 2 CdSi 5 O 12 , Cs 2 MnSi 5 O 12 and Cs 2 CoSi 5 O 12 are 46-1491, 46-1492 and 46-1493, respectively. (orig.)

Determination of "1"3"5Cs by accelerator mass spectrometry

International Nuclear Information System (INIS)

MacDonald, C.M.; Charles, C.R.J.; Zhao, X.-L.; Kieser, W.E.; Cornett, R.J.; Litherland, A.E.

2015-01-01

The ratio of anthropogenic "1"3"5Cs and "1"3"7Cs isotopes is characteristic of a uranium fission source. This research evaluates the technique of isotope dilution (yield tracing) for the purpose of quantifying "1"3"5Cs by accelerator mass spectrometry with on-line isobar separation. Interferences from Ba, Zn_2, and isotopes of equal mass to charge ratios were successfully suppressed. However, some sample crosstalk from source contamination remains. The transmission and di-fluoride ionization efficiencies of Cs isotopes were found to be 8 × 10"−"3 and 1.7 × 10"−"7 respectively. This quantification of "1"3"5Cs using yield tracing by accelerator mass spectrometry shows promise for future environmental sample analysis once the issues of sample crosstalk and low efficiency can be resolved.

137Cs applicability to soil erosion assessment: theoretical and empirical model

International Nuclear Information System (INIS)

Andrello, Avacir Casanova

2004-02-01

The soil erosion processes acceleration and the increase of soil erosion rates due to anthropogenic perturbation in soil-weather-vegetation equilibrium has influenced in the soil quality and environment. So, the possibility to assess the amplitude and severity of soil erosion impact on the productivity and quality of soil is important so local scale as regional and global scale. Several models have been developed to assess the soil erosion so qualitative as quantitatively. 137 Cs, an anthropogenic radionuclide, have been very used to assess the superficial soil erosion process Empirical and theoretical models were developed on the basis of 137 Cs redistribution as indicative of soil movement by erosive process These models incorporate many parameters that can influence in the soil erosion rates quantification by 137 Cs redistribution. Statistical analysis was realized on the models recommended by IAEA to determinate the influence that each parameter generates in results of the soil redistribution. It was verified that the most important parameter is the 137 Cs redistribution, indicating the necessity of a good determination in the 137 Cs inventory values with a minimum deviation associated with these values. After this, it was associated a 10% deviation in the reference value of 137 Cs inventory and the 5% in the 137 Cs inventory of the sample and was determinate the deviation in results of the soil redistribution calculated by models. The results of soil redistribution was compared to verify if there was difference between the models, but there was not difference in the results determinate by models, unless above 70% of 137 Cs loss. Analyzing three native forests and an area of the undisturbed pasture in the Londrina region, can be verified that the 137 Cs spatial variability in local scale was 15%. Comparing the 137 Cs inventory values determinate in the three native forest with the 137 Cs inventory value determinate in the area of undisturbed pasture in the

Enhanced desorption of Cs from clays by a polymeric cation-exchange agent

Energy Technology Data Exchange (ETDEWEB)

Park, Chan Woo, E-mail: park85@gmail.com [Decontamination & Decommissioning Research Division, Korea Atomic Energy Research Institute, Daedeok-daero 989-111, Yuseong-gu, Daejeon (Korea, Republic of); Kim, Bo Hyun [Decontamination & Decommissioning Research Division, Korea Atomic Energy Research Institute, Daedeok-daero 989-111, Yuseong-gu, Daejeon (Korea, Republic of); Department of Chemical Engineering, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon (Korea, Republic of); Yang, Hee-Man; Seo, Bum-Kyoung [Decontamination & Decommissioning Research Division, Korea Atomic Energy Research Institute, Daedeok-daero 989-111, Yuseong-gu, Daejeon (Korea, Republic of); Lee, Kune-Woo, E-mail: nkwlee@kaeri.re.kr [Decontamination & Decommissioning Research Division, Korea Atomic Energy Research Institute, Daedeok-daero 989-111, Yuseong-gu, Daejeon (Korea, Republic of)

2017-04-05

Highlights: • A cationic polyelectrolyte has excellent ability to desorb Cs bound strongly to clay. • The polycation desorbed significantly more Cs from the clay than did single cations. • Additional NH{sub 4}{sup +} treatment following the polycation treatment enhanced desorption of Cs. • The reaction yielded efficient desorption (95%) of an extremely low concentration of Cs-137 in the clay. - Abstract: We report on a new approach to increase the removal of cesium from contaminated clays based on the intercalation of a cationic polyelectrolyte into the clay interlayers. A highly charged cationic polyelectrolyte, polyethyleneimine (PEI), was shown to intercalate into the negatively charged interlayers and readily replaced Cs ions adsorbed on the interlayers of montmorillonite. The polycation desorbed significantly more Cs strongly bound to the clay than did single cations. Moreover, additional NH{sub 4}{sup +} treatment following the PEI treatment enhanced desorption of Cs ions that were less accessible by the bulky polyelectrolyte. This synergistic effect of PEI with NH{sub 4}{sup +} yielded efficient desorption (95%) of an extremely low concentration of radioactive {sup 137}Cs in the clay, which is very difficult to remove by simple cation-exchange methods due to the increased stability of the binding of Cs to the clay at low Cs concentrations.

Cs and Cl penetration estimation in mortar from fly ash of MSWI

International Nuclear Information System (INIS)

Yamada, K.; Hosokawa, Y.; Haga, K.; Osako, M.

2015-01-01

By the Fukushima Daiichi accident, radioactive Cs was scattered widely in East Japan. From the viewpoint of radionuclide contaminated wastes management, water soluble Cs in the fly ash of incineration of municipal solid wastes (MSWI-FA) is the most serious problem. When final disposal of MSWI-FA contaminated by radioactive Cs in concrete pit is considered, it is necessary to understand the characteristics of MSWI-FA and Cs penetration behavior into concrete. In this study, the expected solution generated from MSWI-FA is analyzed and immersion test of mortar in this model solution was carried out for several kinds of cement and sand types. Cs showed similar penetration profiles with Cl regardless of cement and sand types. By using fly ash cement, the penetration depth of Cs decreased less than half compared to ordinary Portland cement (OPC). Clay mineral in sand did not affect the penetration of Cs possible because of the competing effect of potassium for Cs adsorption. Assuming a diffusion equation considering non-linear binding, from the measured profiles, diffusion coefficient and parameters of binding were obtained by fitting. Then, the Cs and Cl profiles after 30 years are estimated and penetration depths of Cs and Cl were only 15 mm for fly ash mortar. (authors)

Environmental sciences: general. 2. Water Adsorption/Absorption by CsOH Particles

International Nuclear Information System (INIS)

Riggs, C.A.; Ghosh, T.K.; Tompson, R.V.; Loyalka, S.K.; Viswanath, D.S.

2001-01-01

Cesium hydroxide in aerosol form is likely to be a significant source of radio-cesium released during a reactor transient. Cesium hydroxide particles are hydrophilic and absorb/adsorb water rapidly. The result is a rapid growth of cesium hydroxide wetted agglomerates that can deposit on surfaces by gravitational settling. However, they can also react with iodine gas to form CsI according to Eq. (1). The rapid absorption/adsorption of water by CsOH may increase the rate of absorption of iodine by CsOH. Iodine may attach itself to adsorbed water molecules on CsOH and facilitate the reaction by bringing iodine to CsOH. Thus, the iodine removal mechanism from the pressurized water reactor containment atmosphere may change: I 2(g) + 4CsOH (s) ↔ 2CsI (s) + 2CsO (s) + 2H 2 O (l) . (1) Despite the importance of CsOH as an aerosol material released during a reactor transient, we have been unable to find any isotherm data of water on cesium hydroxide in the literature. The significant hydrophilic nature of CsOH, together with its being the strongest base currently known, present challenges to collection of water adsorption data. The objective in this research was to experimentally obtain isotherm data of water vapor on CsOH for a range of temperatures and pressures on macroscopic samples using an electro-balance. These data then may be used to predict the amount of water vapor adsorbed on CsOH at other temperatures and pressures by existing models. The adsorption apparatus using a Cahn 2000 electro-balance is shown in Fig. 1. The water adsorption/absorption data on CsOH at different relative pressures of water vapor were obtained gravimetrically. A detailed description of the experimental system is given in Hassan et al. An∼70-mg sample of CsOH.H 2 O (s) was placed onto a platinum weighing dish in the hang-down tube of the balance. The sample was regenerated by heating it at 100 deg. C under a vacuum of 3.5x10 -2 mm Hg for 24 h to remove adsorbed water and other gases

Infrared absorption of gaseous ClCS detected with time-resolved Fourier-transform spectroscopy

International Nuclear Information System (INIS)

Chu, Li-Kang; Han, Hui-Ling; Lee, Yuan-Pern

2007-01-01

A transient infrared absorption spectrum of gaseous ClCS was detected with a step-scan Fourier-transform spectrometer coupled with a multipass absorption cell. ClCS was produced upon irradiating a flowing mixture of Cl 2 CS and N 2 or CO 2 with a KrF excimer laser at 248 nm. A transient band in the region of 1160-1220 cm -1 , which diminished on prolonged reaction, is assigned to the C-S stretching (ν 1 ) mode of ClCS. Calculations with density-functional theory (B3P86 and B3LYP/aug-cc-pVTZ) predict the geometry, vibrational wave numbers, and rotational parameters of ClCS. The rotational contour of the spectrum of ClCS simulated based on predicted rotational parameters agrees satisfactorily with experimental observation; from spectral simulation, the band origin is determined to be at 1194.4 cm -1 . Reaction kinetics involving ClCS, CS, and CS 2 are discussed

Performance verification tests of JT-60SA CS model coil

Energy Technology Data Exchange (ETDEWEB)

Obana, Tetsuhiro, E-mail: obana.tetsuhiro@LHD.nifs.ac.jp [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Murakami, Haruyuki [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan); Takahata, Kazuya; Hamaguchi, Shinji; Chikaraishi, Hirotaka; Mito, Toshiyuki; Imagawa, Shinsaku [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Kizu, Kaname; Natsume, Kyohei; Yoshida, Kiyoshi [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan)

2015-11-15

Highlights: • The performance of the JT-60SA CS model coil was verified. • The CS model coil comprised a quad-pancake wound with a Nb{sub 3}Sn CIC conductor. • The CS model coil met the design requirements. - Abstract: As a final check of the coil manufacturing method of the JT-60 Super Advanced (JT-60SA) central solenoid (CS), we verified the performance of a CS model coil. The model coil comprised a quad-pancake wound with a Nb{sub 3}Sn cable-in-conduit conductor. Measurements of the critical current, joint resistance, pressure drop, and magnetic field were conducted in the verification tests. In the critical-current measurement, the critical current of the model coil coincided with the estimation derived from a strain of −0.62% for the Nb{sub 3}Sn strands. As a result, critical-current degradation caused by the coil manufacturing process was not observed. The results of the performance verification tests indicate that the model coil met the design requirements. Consequently, the manufacturing process of the JT-60SA CS was established.

Formation of stars and star clusters in colliding galaxies

International Nuclear Information System (INIS)

Belles, Pierre-Emmanuel

2012-01-01

Mergers are known to be essential in the formation of large-scale structures and to have a significant role in the history of galaxy formation and evolution. Besides a morphological transformation, mergers induce important bursts of star formation. These starburst are characterised by high Star Formation Efficiencies (SFEs) and Specific Star Formation Rates, i.e., high Star Formation Rates (SFR) per unit of gas mass and high SFR per unit of stellar mass, respectively, compared to spiral galaxies. At all redshifts, starburst galaxies are outliers of the sequence of star-forming galaxies defined by spiral galaxies. We have investigated the origin of the starburst-mode of star formation, in three local interacting systems: Arp 245, Arp 105 and NGC 7252. We combined high-resolution JVLA observations of the 21-cm line, tracing the HI diffuse gas, with UV GALEX observations, tracing the young star-forming regions. We probe the local physical conditions of the Inter-Stellar Medium (ISM) for independent star-forming regions and explore the atomic-to-dense gas transformation in different environments. The SFR/HI ratio is found to be much higher in central regions, compared to outer regions, showing a higher dense gas fraction (or lower HI gas fraction) in these regions. In the outer regions of the systems, i.e., the tidal tails, where the gas phase is mostly atomic, we find SFR/HI ratios higher than in standard HI-dominated environments, i.e., outer discs of spiral galaxies and dwarf galaxies. Thus, our analysis reveals that the outer regions of mergers are characterised by high SFEs, compared to the standard mode of star formation. The observation of high dense gas fractions in interacting systems is consistent with the predictions of numerical simulations; it results from the increase of the gas turbulence during a merger. The merger is likely to affect the star-forming properties of the system at all spatial scales, from large scales, with a globally enhanced turbulence

Stars Just Got Bigger - A 300 Solar Mass Star Uncovered

Science.gov (United States)

2010-07-01

Using a combination of instruments on ESO's Very Large Telescope, astronomers have discovered the most massive stars to date, one weighing at birth more than 300 times the mass of the Sun, or twice as much as the currently accepted limit of 150 solar masses. The existence of these monsters - millions of times more luminous than the Sun, losing weight through very powerful winds - may provide an answer to the question "how massive can stars be?" A team of astronomers led by Paul Crowther, Professor of Astrophysics at the University of Sheffield, has used ESO's Very Large Telescope (VLT), as well as archival data from the NASA/ESA Hubble Space Telescope, to study two young clusters of stars, NGC 3603 and RMC 136a in detail. NGC 3603 is a cosmic factory where stars form frantically from the nebula's extended clouds of gas and dust, located 22 000 light-years away from the Sun (eso1005). RMC 136a (more often known as R136) is another cluster of young, massive and hot stars, which is located inside the Tarantula Nebula, in one of our neighbouring galaxies, the Large Magellanic Cloud, 165 000 light-years away (eso0613). The team found several stars with surface temperatures over 40 000 degrees, more than seven times hotter than our Sun, and a few tens of times larger and several million times brighter. Comparisons with models imply that several of these stars were born with masses in excess of 150 solar masses. The star R136a1, found in the R136 cluster, is the most massive star ever found, with a current mass of about 265 solar masses and with a birthweight of as much as 320 times that of the Sun. In NGC 3603, the astronomers could also directly measure the masses of two stars that belong to a double star system [1], as a validation of the models used. The stars A1, B and C in this cluster have estimated masses at birth above or close to 150 solar masses. Very massive stars produce very powerful outflows. "Unlike humans, these stars are born heavy and lose weight as

Evaluation of caesium atomic fountain NICT-CsF1

International Nuclear Information System (INIS)

Kumagai, M.; Ito, H.; Kajita, M.; Hosokawa, M.

2008-01-01

In this paper, we describe the first caesium atomic fountain primary frequency standard NICT-CsF1 of National Institute of Information Communications Technology (NICT) in Tokyo, Japan. The structure of the NICT-CsF1 system and evaluation procedure of the systematic frequency shifts and their uncertainties are presented. Typically, NICT-CsF1 has a frequency stability of 4 * 10 -13 /τ 1/2 and a frequency uncertainty of 1.9 * 10 -15 . (authors)

The Destructive Birth of Massive Stars and Massive Star Clusters

Science.gov (United States)

Rosen, Anna; Krumholz, Mark; McKee, Christopher F.; Klein, Richard I.; Ramirez-Ruiz, Enrico

2017-01-01

Massive stars play an essential role in the Universe. They are rare, yet the energy and momentum they inject into the interstellar medium with their intense radiation fields dwarfs the contribution by their vastly more numerous low-mass cousins. Previous theoretical and observational studies have concluded that the feedback associated with massive stars' radiation fields is the dominant mechanism regulating massive star and massive star cluster (MSC) formation. Therefore detailed simulation of the formation of massive stars and MSCs, which host hundreds to thousands of massive stars, requires an accurate treatment of radiation. For this purpose, we have developed a new, highly accurate hybrid radiation algorithm that properly treats the absorption of the direct radiation field from stars and the re-emission and processing by interstellar dust. We use our new tool to perform a suite of three-dimensional radiation-hydrodynamic simulations of the formation of massive stars and MSCs. For individual massive stellar systems, we simulate the collapse of massive pre-stellar cores with laminar and turbulent initial conditions and properly resolve regions where we expect instabilities to grow. We find that mass is channeled to the massive stellar system via gravitational and Rayleigh-Taylor (RT) instabilities. For laminar initial conditions, proper treatment of the direct radiation field produces later onset of RT instability, but does not suppress it entirely provided the edges of the radiation-dominated bubbles are adequately resolved. RT instabilities arise immediately for turbulent pre-stellar cores because the initial turbulence seeds the instabilities. To model MSC formation, we simulate the collapse of a dense, turbulent, magnetized Mcl = 106 M⊙ molecular cloud. We find that the influence of the magnetic pressure and radiative feedback slows down star formation. Furthermore, we find that star formation is suppressed along dense filaments where the magnetic field is

Cs-134 and Cs-137 radioactivity in river waters in Fukushima, Miyagi, Ibaraki and Gunma Prefectures in August 2012 after the Fukuhsima Daiichi Nuclear Power Plant accident

Energy Technology Data Exchange (ETDEWEB)

Nagao, S.; Ochiai, S.; Yamamoto, M. [Low Level Radioactivity Laboratory, Institute of Nature and Environmental Technology, Kanazawa University, Wake, Nomi, Ishikawa 923-1224(Japan); Kanamori, M. [Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa, Ishikawa 921-1192 (Japan); Tomihara, S. [Environmental Aquarium Aquamarine Fukushima, 50 Tatsumi, Onahama, Iwaki, Fukushima 971-8101(Japan); Suzuki, K. [Gunma Prefectural Fisheries Experimental Station, 13 Shikishima, Maebashi, Gunma 371-1036 (Japan)

2014-07-01

About 15 PBq from both {sup 134}Cs and {sup 137}Cs were released from the Fukushima Dai-ichi Nuclear Power Plant (NPP) because of venting operations and hydrogen explosions. The Ministry of Education, Culture, Sports, Science and Technology of Japan reported total surface deposition of {sup 134}Cs and {sup 137}Cs in Japan. To estimate short-term and long-term impacts of the radiation dose in Japan, it is important to understand the dynamics of radionuclides, especially those of {sup 134}Cs and {sup 137}Cs, on river watershed environments. This study investigated {sup 134}Cs and {sup 137}Cs radioactivity in river systems in Fukushima, Miyagi, Ibaraki and Gunma prefectures, Japan. The secondary radioactive dispersion of radiocesium from the contaminated watershed to the river waters is reported for research areas with widely various radiocesium deposition on ground surfaces at 18 months after the accident. Field experiments were conducted at a fixed station in four rivers (the Uta, Niida, Natsui, and Same Rivers) in Fukushima Prefecture, and the Kuji River, and Naka River in Ibaraki Prefecture in August 2012. The Abukuma River was set up one site at the upper, two sites in the middle reach in Fukushima Prefecture and at one site in the lower area in Miyagi Prefecture. The Tone River system has three stations at the upper river area in Gunma Prefecture and one site at the lower reach in Ibaraki Prefecture. Surface deposition results reveals significant external radioactivity in a zone extending northwest from the NPP. However, a mountainous area in Gunma Prefecture, located about 220 km from Fukushima Dai-ichi NPP south of Fukushima Prefecture, shows similar accumulation of {sup 134}Cs and {sup 137}Cs. The 20 L of surface river waters were collected at the station using buckets. The radioactivity of {sup 134}Cs and {sup 137}Cs in the river waters was measured with gamma-ray spectrometry using ammonium molybdophosphate (AMP)/Cs compound method with a low background Ge

A Near-Infrared Surface Compositional Analysis of Blue Straggler Stars in Open Cluster M67

Science.gov (United States)

Seifert, Richard; Gosnell, Natalie M.; Sneden, Chris

2017-06-01

Blue straggler stars (BSSs) are stars whose evolutions have been directly impacted by binary system interactions. By obtaining additional mass from a companion, BSSs are able to live prolonged lives on the main sequence. BSSs bring confusions to studies that rely on a standard stellar evolutionary track when modeling stellar populations, since the presence of BSSs can make a population appear younger than it actually is. It is important to have a better understanding of the mechanisms that drive BSS formation so that BSSs may be correctly accounted for in future studies.Blue stagglers in clusters primarily form in one of two ways; either from a close binary system in which one star accretes mass from its companion star or from a hierarchical trinary system in which a close inner binary merges as a result of perturbations from a farther-orbiting third star. In order to investigate the nature of this mass transfer, We obtained IGRINS H-band high resolution spectra of 6 BSSs and 12 red giant stars in open cluster M67. Using a grid of synthetic spectra obtained from the line analysis code MOOG, we identified and fit abundances for absorption lines of iron, silicon, and carbon. Depending on the evolutionary stage of the donor star, the abundance of carbon in the resulting BSS can be affected by mixing during the mass transfer. By analyzing the abundance of carbon in our targets, we find that [Fe/H] ~= 0 and [C/H] ~= 0. We see no evidence of depletion of carbon from RGB-phase mass transfer or enhancement of carbon from AGB-phase mass transfer, implying that the mass transfer occured earlier in the donar star's evolution.Funding for this research comes from the John W. Cox endowment for the Advanced Studies in Astronomy. For support of this work we acknowledge NSF grants AST-1211585 and AST-1616040 to CS. The successful development of the IGRINS spectrograph has resulted from the combined efforts of teams at the University of Texas at Austin and the Korea Astronomy and

DETERMINING THE AGE OF THE KEPLER OPEN CLUSTER NGC 6819 WITH A NEW TRIPLE SYSTEM AND OTHER ECLIPSING BINARY STARS

International Nuclear Information System (INIS)

Brewer, Lauren N.; Sandquist, Eric L.; Jeffries, Mark W. Jr.; Orosz, Jerome A.

2016-01-01

As part of our study of the old (∼2.5 Gyr) open cluster NGC 6819 in the Kepler field, we present photometric (Kepler and ground-based BVR C I C ) and spectroscopic observations of the detached eclipsing binary WOCS 24009 (Auner 665; KIC 5023948) with a short orbital period of 3.6 days. WOCS 24009 is a triple-lined system, and we verify that the brightest star is physically orbiting the eclipsing binary using radial velocities and eclipse timing variations. The eclipsing binary components have masses M B  = 1.090 ± 0.010 M ⊙ and M C  = 1.075 ± 0.013 M ⊙ , and radii R B  = 1.099 ± 0.006 ± 0.005 R ⊙ and R C  = 1.069 ± 0.006 ± 0.013 R ⊙ . The bright non-eclipsing star resides at the cluster turnoff, and ultimately its mass will directly constrain the turnoff mass: our preliminary determination is M A  = 1.251 ± 0.057 M ⊙ . A careful examination of the light curves indicates that the fainter star in the eclipsing binary undergoes a very brief period of total eclipse, which enables us to precisely decompose the light of the three stars and place them in the color–magnitude diagram (CMD). We also present improved analysis of two previously discussed detached eclipsing stars in NGC 6819 (WOCS 40007 and WOCS 23009) en route to a combined determination of the cluster’s distance modulus (m − M) V  = 12.38 ± 0.04. Because this paper significantly increases the number of measured stars in the cluster, we can better constrain the age of the CMD to be 2.21 ± 0.10 ± 0.20 Gyr. Additionally, using all measured eclipsing binary star masses and radii, we constrain the age to 2.38 ± 0.05 ± 0.22 Gyr. The quoted uncertainties are estimates of measurement and systematic uncertainties (due to model physics differences and metal content), respectively

First stars X. The nature of three unevolved carbon-enhanced metal-poor stars

DEFF Research Database (Denmark)

Sivarani, T.; Beers, T.C.; Bonifacio, P.

2006-01-01

Stars: abundances, stars: population II, Galaxy: abundances, stars: AGB and post-AGB Udgivelsesdato: Nov.......Stars: abundances, stars: population II, Galaxy: abundances, stars: AGB and post-AGB Udgivelsesdato: Nov....

Experimental studies on radiation damages of CsI(Tl) crystals

International Nuclear Information System (INIS)

He Jingtang; Mao Yufang; Dong Xiaoli; Chen Duanbao; Li Zuhao

1997-01-01

The results of experimental studies on radiation damage of CsI(Tl) crystal were reported. There are radiation damage effects on CsI(Tl) crystal. Experimental studies on recovery of damaged CsI(Tl) crystals were made. It seems that after heating at 200 degree C for 4 hours, the damaged crystals could be recovered completely

137Cs in Norwegian Lapps, spring 1980

International Nuclear Information System (INIS)

Westerlund, E.A.; Gjertsen, L.; Lind, B.

1980-01-01

Measurements show that the body burden of 137 in Lapps in Norway fell from 1965 to 1975 with an apparent half-life of 4-5 years. Since then the reduction has been considerably slower due to fallout from Chinese nuclear weapon tests. The content of 137 Cs in reindeer meat follows the same pattern. Seasonal variations occur due to the migration of the reindeer between winter grazing on lichen with a high 137 Cs content and summer grazing on grass with a lower 137 Cs content. For annual dose calculations it is found that whole body mearurements at the end of March or the beginning of April give good values. Radiation doses to Lapps working small holdings are about 3/4 of those of nomadic reindeer-herding Lapps. (JIW)

Thermodynamic studies of (RbF + RbCl + H2O) and (CsF + CsCl + H2O) ternary systems from potentiometric measurements at T = 298.2 K

International Nuclear Information System (INIS)

Huang, Xiaoting; Li, Shu’ni; Zhai, Quanguo; Jiang, Yucheng; Hu, Mancheng

2016-01-01

Graphical abstract: Thermodynamic properties, such as mean activity coefficients, osmotic coefficients and excess Gibbs free energies, of the RbF + RbCl + H 2 O and CsF + CsCl + H 2 O ternary systems were determined from potentiometric measurement at 298.2 K. The Pitzer model and the Harned rule were used to fit the experimental data. - Highlights: • Thermodynamic properties of RbF + RbCl + H 2 O and CsF + CsCl + H 2 O ternary systems were determined. • The Pitzer model and the Harned rule were used to correlate the experimental data. • The mean activity coefficients, osmotic coefficients, and the excess Gibbs free energy were also obtained. - Abstract: Thermodynamic properties of (RbF + RbCl + H 2 O) and (CsF + CsCl + H 2 O) systems were determined by the potentiometric method for different ionic strength fractions y B of RbCl/CsCl at 298.2 K. The Pitzer model and the Harned rule were used to fit the experimental values. The Pitzer mixing parameters and the Harned coefficients were evaluated. In addition, the mean ionic activity coefficients of RbF/CsF and RbCl/CsCl, the osmotic coefficients, and the excess Gibbs energies of the systems studied were calculated.

The feature and distribution of 137Cs in the forest soil

International Nuclear Information System (INIS)

Narazaki, Yukinori

2002-01-01

The 137 Cs concentration in an undisturbed upper layer of naked land in Fukuoka Prefecture decreased exponentially from 1969 to 1999 with the apparent half-life of 7 years. The ratio of 137 Cs concentration in the lower layer of the soil to that in the upper layer was about 1/5. The concentration of 137 Cs, 40 K, and stable Cs and the soil profile consisting of loss on ignition, pH, and electric conductivity were determined in the 48 samples collected in the forests and the neighboring naked land from 1991 to 1998. The 137 Cs concentration in the forest soils ranged from 1 to 424 Bq/kg dry wt, 131 Bq/kg dry wt on average, although 137 Cs was hardly detected in the naked soil around the forest. There was no regional difference in the distribution of the 137 Cs concentration, and it varied with pH and electric conductivity in the soil. Further, it tended to be higher in the deciduous woodland than in the evergreen woodland. (author)

Phonon dispersion curves for CsCN

International Nuclear Information System (INIS)

Gaur, N.K.; Singh, Preeti; Rini, E.G.; Galgale, Jyostna; Singh, R.K.

2004-01-01

The motivation for the present work was gained from the recent publication on phonon dispersion curves (PDCs) of CsCN from the neutron scattering technique. We have applied the extended three-body force shell model (ETSM) by incorporating the effect of coupling between the translation modes and the orientation of cyanide molecules for the description of phonon dispersion curves of CsCN between the temperatures 195 and 295 K. Our results on PDCs in symmetric direction are in good agreement with the experimental data measured with inelastic neutron scattering technique. (author)

Parameters Affecting 137Cs Migration within Soil Profile

International Nuclear Information System (INIS)

Sefien, S.M.; Ibrahim, A.S.; Abdelmalik, W.E.Y.

2013-01-01

Some studies have been carried out on the adsorption, distribution and migration of 137 Cs within soils of the area in the vicinity of the Nuclear Research Centre, Egypt, and Ismailia Canal. The soil physicochemical and mineralogical characteristics were carried out and indicated that the soil samples consisted mainly of sand fraction (quartz) and silt fractions (semctite minerals). The kinetics of caesium adsorption and its adsorption isotherms for the tested soils were also studied. The sorption of 137 Cs on soil minerals markedly affects its migration rate. The natural background of both locations of study indicated that the amounts of 137 Cs present in the reactor site were found to be originated from the fallout and from the external contamination which affected the background level. The 137 Cs activity at the canal site was found to be 20.01 Bq/m 2 .cm, while that around the reactor site were found to be 231.15 Bq/m2.cm which may be originating from the fallout and from external contamination which affect the background level at that location. The activity in the canal soil which amounted to 20.01 Bq/m2/cm (0.87 Bq/kg) is about that of background.Based on the distribution data, the vertical distribution of 137 Cs has been studied for soil in both locations (the vicinity of the Nuclear Research Centre (NRC) and Ismailia canal). The vertical migration rates of 137 Cs were calculated for soil samples selected from different locations. These rates were found to be 0.056 and 0.031 cm/year for the reactor and canal site respectively.

Detection of HCN and C2H2 in ISO Spectra of Oxygen-Rich AGB Stars

Science.gov (United States)

Carbon, Duane F.; Chiar, Jean; Goorvitch, David; Kwak, Dochan (Technical Monitor)

2002-01-01

Cool oxygen-rich AGB stars were not expected to have organic molecules like HCN in either their photospheres or circumstellar envelopes (CSEs). The discovery of HCN and CS microwave emission from the shallowest CSE layers of these stars was a considerable surprise and much theoretical effort has been expended in explaining the presence of such organics. To further explore this problem, we have undertaken a systematic search of oxygen-rich AGB stellar spectra in the Infrared Space Observatory (ISO) data archive. Our purposes are to find evidence regarding critical molecular species that could be of value in choosing among the proposed theoretical models, to locate spectral features which might give clues to conditions deeper in the CSEs, and to lay the groundwork for future SIRTF (Space Infrared Telescope Facility) and SOFIA (Stratospheric Observatory for Infrared Astronomy) observations. Using carefully reduced observations, we have detected weak absorption features arising from HCN and possibly C2H2 in a small number of oxygen-rich AGB stars. The most compelling case is NML Cyg which shows both HCN (14 microns) and CO2 (15 microns). VY CMa, a similar star, shows evidence for HCN, but not CO2. Two S-type stars show evidence for the C-H bending transitions: W Aql at 14 microns (HCN) and both W Aql and S Cas at 13.7 microns (C2H2). Both W Aql and S Cas as well as S Lyr, a SC-type star, show 3 micron absorption which may arise from the C-H stretch of HCN and C2H2. In the case of NML Cyg, we show that the HCN and CO2 spectral features are formed in the CSE at temperatures well above those of the outermost CSE layers and derive approximate column densities. In the case of the S-stars, we discuss the evidence for the organic features and their photospheric origin.

False star detection and isolation during star tracking based on improved chi-square tests.

Science.gov (United States)

Zhang, Hao; Niu, Yanxiong; Lu, Jiazhen; Yang, Yanqiang; Su, Guohua

2017-08-01

The star sensor is a precise attitude measurement device for a spacecraft. Star tracking is the main and key working mode for a star sensor. However, during star tracking, false stars become an inevitable interference for star sensor applications, which may result in declined measurement accuracy. A false star detection and isolation algorithm in star tracking based on improved chi-square tests is proposed in this paper. Two estimations are established based on a Kalman filter and a priori information, respectively. The false star detection is operated through adopting the global state chi-square test in a Kalman filter. The false star isolation is achieved using a local state chi-square test. Semi-physical experiments under different trajectories with various false stars are designed for verification. Experiment results show that various false stars can be detected and isolated from navigation stars during star tracking, and the attitude measurement accuracy is hardly influenced by false stars. The proposed algorithm is proved to have an excellent performance in terms of speed, stability, and robustness.

General Strategy for Rapid Production of Low-Dimensional All-Inorganic CsPbBr3 Perovskite Nanocrystals with Controlled Dimensionalities and Sizes.

Science.gov (United States)

Liu, Wenna; Zheng, Jinju; Cao, Sheng; Wang, Lin; Gao, Fengmei; Chou, Kuo-Chih; Hou, Xinmei; Yang, Weiyou

2018-02-05

Currently, all-inorganic CsPbX 3 (X = Br, I, Cl) perovskite nanocrystals (NCs) are shining stars with exciting potential applications in optoelectronic devices such as solar cells, light-emitting diodes, lasers, and photodetectors, due to their superior performance in comparison to their organic-inorganic hybrid counterparts. In the present work, we report a general strategy based on a microwave technique for the rapid production of low-dimensional all-inorganic CsPbBr 3 perovskite NCs with tunable morphologies within minutes. The effect of the key parameters such as the introduced ligands, solvents, and PbBr 2 precursors and microwave powers as well as the irradiation times on the production of perovskite NCs was systematically investigated, which allowed their growth with tunable dimensionalities and sizes. As a proof of concept, the ratio of OA to OAm as well as the concentration of PbBr 2 precursor played important roles in triggering the anisotropic growth of the perovskite NCs, favoring their growth into 1D/2D single-crystalline nanostructures. Meanwhile, their sizes could be tailored by controlling the microwave powers and irradiation times. The mechanism for the tunable growth of perovskite NCs is discussed.

White Dwarf Stars

OpenAIRE

Kepler, S. O.; Romero, Alejandra Daniela; Pelisoli, Ingrid; Ourique, Gustavo

2017-01-01

White dwarf stars are the final stage of most stars, born single or in multiple systems. We discuss the identification, magnetic fields, and mass distribution for white dwarfs detected from spectra obtained by the Sloan Digital Sky Survey up to Data Release 13 in 2016, which lead to the increase in the number of spectroscopically identified white dwarf stars from 5000 to 39000. This number includes only white dwarf stars with log g >= 6.5 stars, i.e., excluding the Extremely Low Mass white dw...

134Cs emission probabilities determination by gamma spectrometry

Science.gov (United States)

de Almeida, M. C. M.; Poledna, R.; Delgado, J. U.; Silva, R. L.; Araujo, M. T. F.; da Silva, C. J.

2018-03-01

The National Laboratory for Ionizing Radiation Metrology (LNMRI/IRD/CNEN) of Rio de Janeiro performed primary and secondary standardization of different radionuclides reaching satisfactory uncertainties. A solution of 134Cs radionuclide was purchased from commercial supplier to emission probabilities determination of some of its energies. 134Cs is a beta gamma emitter with 754 days of half-life. This radionuclide is used as standard in environmental, water and food control. It is also important to germanium detector calibration. The gamma emission probabilities (Pγ) were determined mainly for some energies of the 134Cs by efficiency curve method and the Pγ absolute uncertainties obtained were below 1% (k=1).

THE PREVALENCE AND IMPACT OF WOLF–RAYET STARS IN EMERGING MASSIVE STAR CLUSTERS

Energy Technology Data Exchange (ETDEWEB)

Sokal, Kimberly R.; Johnson, Kelsey E.; Indebetouw, Rémy [Department of Astronomy, University of Virginia, P.O. Box 3818, Charlottesville, VA 22903 (United States); Massey, Philip, E-mail: krs9tb@virginia.edu [Lowell Observatory, 1400 W Mars Hill Road, Flagstaff, AZ 86001 (United States)

2016-08-01

We investigate Wolf–Rayet (WR) stars as a source of feedback contributing to the removal of natal material in the early evolution of massive star clusters. Despite previous work suggesting that massive star clusters clear out their natal material before the massive stars evolve into the WR phase, WR stars have been detected in several emerging massive star clusters. These detections suggest that the timescale for clusters to emerge can be at least as long as the time required to produce WR stars (a few million years), and could also indicate that WR stars may be providing the tipping point in the combined feedback processes that drive a massive star cluster to emerge. We explore the potential overlap between the emerging phase and the WR phase with an observational survey to search for WR stars in emerging massive star clusters hosting WR stars. We select candidate emerging massive star clusters from known radio continuum sources with thermal emission and obtain optical spectra with the 4 m Mayall Telescope at Kitt Peak National Observatory and the 6.5 m MMT.{sup 4} We identify 21 sources with significantly detected WR signatures, which we term “emerging WR clusters.” WR features are detected in ∼50% of the radio-selected sample, and thus we find that WR stars are commonly present in currently emerging massive star clusters. The observed extinctions and ages suggest that clusters without WR detections remain embedded for longer periods of time, and may indicate that WR stars can aid, and therefore accelerate, the emergence process.

Modulation of electronic and optical properties in mixed halide perovskites CsPbCl3xBr3(1-x) and CsPbBr3xI3(1-x)

Science.gov (United States)

Zhou, Ziqi; Cui, Yu; Deng, Hui-Xiong; Huang, Le; Wei, Zhongming; Li, Jingbo

2017-03-01

The recent discovery of lead halide perovskites with band gaps in the visible presents important potential in the design of high efficient solar cells. CsPbCl3, CsPbBr3 and CsPbI3 are stable compounds within this new family of semiconductors. By performing the first-principles calculation, we explore the structural, electronic and optical properties of CsPbCl3xBr3(1-x) and CsPbBr3xI3(1-x) with various compositions of halide atoms. Structural stability is demonstrated with halide atoms distributing randomly at the halide atomic sites. CsPbCl3xBr3(1-x) and CsPbBr3xI3(1-x) exhibit the modulation of their band gaps by varying the halide composition. Our results also indicate that CsPbCl3xBr3(1-x) and CsPbBr3xI3(1-x) with different halide compositions are suitable to application to solar cells for the general features are well preserved. Good absorption to lights of different wavelengths has been obtained in these mixed halide perovskites.

Egyptian "Star Clocks"

Science.gov (United States)

Symons, Sarah

Diagonal, transit, and Ramesside star clocks are tables of astronomical information occasionally found in ancient Egyptian temples, tombs, and papyri. The tables represent the motions of selected stars (decans and hour stars) throughout the Egyptian civil year. Analysis of star clocks leads to greater understanding of ancient Egyptian constellations, ritual astronomical activities, observational practices, and pharaonic chronology.

Syntheses, crystal structure, and electronic properties of the five ABaMQ{sub 4} compounds RbBaPS{sub 4}, CsBaPS{sub 4}, CsBaVS{sub 4}, RbBaVSe{sub 4}, and CsBaVSe{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Mesbah, Adel [Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113 (United States); ICSM, UMR 5257 CEA / CNRS / UM / ENSCM, Site de Marcoule-Bâtiment 426, BP 17171, 30207 Bagnols-sur-Cèze Cedex (France); Prakash, Jai [Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113 (United States); Rocca, Dario; Lebègue, Sébastien [Laboratoire de Cristallographie, Résonance Magnétique, et Modélisations CRM2 (UMR UHP-CNRS 7036), Faculté des Sciences et Techniques, Université de Lorraine, BP 70239, Boulevard des Aiguillettes, 54506 Vandoeuvre-lès-Nancy Cedex (France); Beard, Jessica C.; Lewis, Benjamin A. [Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113 (United States); Ibers, James A., E-mail: ibers@chem.northwestern.edu [Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113 (United States)

2016-01-15

Five new compounds belonging to the ABaMQ{sub 4} family were synthesized by solid-state chemistry at 1123 K. The compounds RbBaPS{sub 4}, CsBaPS{sub 4}, CsBaVS{sub 4}, RbBaVSe{sub 4}, and CsBaVSe{sub 4} are isostructural and have the TlEuPS{sub 4} structure type. They crystallize in space group D{sup 16}{sub 2h} – Pnma of the orthorhombic system. Their structure consists isolated MQ{sub 4} tetrahedra separated by A and Ba atoms to form a salt-like structure. Density Functional Theory (DFT) calculations of the electronic structures with the use of the HSE functional suggest that the compounds are semiconductors with calculated band gaps of 3.3 eV (RbBaPS{sub 4}), 3.4 eV (CsBaPS{sub 4}), 2.3 eV (CsBaVS{sub 4}), and 1.6 eV (RbBaVSe{sub 4}). - Graphical abstract: General view of the ABaMQ{sub 4} structure down the a axis. - Highlights: • Five new ABaMQ{sub 4} compounds were synthesized by solid-state chemistry at 1123 K. • RbBaPS{sub 4}, CsBaPS{sub 4}, CsBaVS{sub 4}, RbBaVSe{sub 4}, and CsBaVSe{sub 4} have the TlEuPS{sub 4} structure type. • The compounds are semiconductors with calculated band gaps ranging from 1.6 to 3.4 eV.

Symbiotic stars

International Nuclear Information System (INIS)

Kafatos, M.; Michalitsianos, A.G.

1984-01-01

Among the several hundred million binary systems estimated to lie within 3000 light years of the solar system, a tiny fraction, no more than a few hundred, belong to a curious subclass whose radiation has a wavelength distribution so peculiar that it long defied explanation. Such systems radiate strongly in the visible region of the spectrum, but some of them do so even more strongly at both shorter and longer wavelengths: in the ultraviolet region and in the infrared and radio regions. This odd distribution of radiation is best explained by the pairing of a cool red giant star and an intensely hot small star that is virtually in contact with its larger companion. Such objects have become known as symbiotic stars. On photographic plate only the giant star can be discerned, but evidence for the existence of the hot companion has been supplied by satellite-born instruments capable of detecting ultraviolet radiation. The spectra of symbiotic stars indicate that the cool red giant is surrounded by a very hot ionized gas. Symbiotic stars also flared up in outbursts indicating the ejection of material in the form of a shell or a ring. Symbiotic stars may therefore represent a transitory phase in the evolution of certain types of binary systems in which there is substantial transfer of matter from the larger partner to the smaller

Exercise for laboratory comparison of calibration coefficient in {sup 137}Cs beam, radiation protection - 2013/2014; Exercicio de comparacao laboratorial do coeficiente de calibracao em feixe de Cesio-137, radioprotecao - 2013/2014

Energy Technology Data Exchange (ETDEWEB)

Cabral, T.S. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Potiens, M.P.A., E-mail: tschirn@ird.gov.br [Instituto de Pesquisas Energeticas e Nucleres (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Soares, C.M.A. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Silveira, R.R. [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Khoury, H. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear; Fernandes, E. [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Laboratorio de Ciencias Radiologicas; Cardoso, W.F. [Eletrobras Termonuclear S.A. (Eletronuclear), Rio de Janeiro, RJ (Brazil); Borges, J.C. [MRA Comercio de Instrumentos Eletronicos Ltda., Ribeirao Preto, SP (Brazil)

2015-07-01

This work deals with the preliminary results of the second exercise of comparing the radiation monitors calibration laboratories in Brazil. The exercise involved eight laboratories and the measured quantity is the air kerma in a beam of {sup 137}Cs for radioprotection. The exercise was conducted by the LNMRI/IRD, in a star shaped arrangement from October 2013 to July 2015. The largest deviation was 2% of the calibration coefficient that is acceptable for applications in radioprotection. (author)

Concentration factors for Cs-137 in marine algae from Japanese coastal waters

International Nuclear Information System (INIS)

Tateda, Yutaka; Koyanagi, Taku.

1994-01-01

Concentration factors (CF: Bq·kg -1 in wet algae/Bq·kg -1 in filtered seawater) for Cs-137 in Japanese coastal algae, were investigated during 1984-1990. Cs-137/Cs (stable) atom ratios were also examined to clarify the distribution equilibrium of Cs-137 in marine algae and sea water. The CFs in marine algae were within the range of 5.4-92, and the geometric mean of CF was 28±2 (standard error) in Japanese coastal species. The CFs in edible species were within the range of 5.4-67, and the geometric means of CF was 26±4 (standard error). The values of Cs-137/Cs atom ratios in marine algae and sea water indicated that Cs-137 reached an equilibrium state in partition between algae and sea water. Therefore, the CF value obtained in the present study can be regarded as an equilibrated value. Our results showed that hte CF for Cs-137 in Japanese coastal algae were consistent with the Japanese guideline CFs, but were smaller than the recommended value by IAEA. (author)

Star tracking method based on multiexposure imaging for intensified star trackers.

Science.gov (United States)

Yu, Wenbo; Jiang, Jie; Zhang, Guangjun

2017-07-20

The requirements for the dynamic performance of star trackers are rapidly increasing with the development of space exploration technologies. However, insufficient knowledge of the angular acceleration has largely decreased the performance of the existing star tracking methods, and star trackers may even fail to track under highly dynamic conditions. This study proposes a star tracking method based on multiexposure imaging for intensified star trackers. The accurate estimation model of the complete motion parameters, including the angular velocity and angular acceleration, is established according to the working characteristic of multiexposure imaging. The estimation of the complete motion parameters is utilized to generate the predictive star image accurately. Therefore, the correct matching and tracking between stars in the real and predictive star images can be reliably accomplished under highly dynamic conditions. Simulations with specific dynamic conditions are conducted to verify the feasibility and effectiveness of the proposed method. Experiments with real starry night sky observation are also conducted for further verification. Simulations and experiments demonstrate that the proposed method is effective and shows excellent performance under highly dynamic conditions.

Deposition of 137Cs in Rokkasho, Japan and its relation to Asian dust

International Nuclear Information System (INIS)

Akata, Naofumi; Hasegawa, Hidenao; Kawabata, Hitoshi; Chikuchi, Yuki; Sato, Tadahiro; Ohtsuka, Yoshihito; Kondo, Kunio; Hisamatsu, Shun'ichi

2007-01-01

Biweekly atmospheric depositions of 137 Cs were measured in Rokkasho, Aomori, Japan from March 2000 to March 2006 to study recent 137 Cs deposition. Although the deposition level was generally lower than the detectable limit, deposition samples collected in spring occasionally had measurable levels of 137 Cs. The annual 137 Cs deposition from 2001 to 2005 was 0.04-0.69 Bq m -2 with a mean value of 0.27 Bq m -2 . Depositions of insoluble Al, Fe and Ti were strongly correlated with the 137 Cs deposition, suggesting that suspension of soil particles was the main source of the recent 137 Cs deposition. Asian dust events were coincident with some of the significant 137 Cs depositions in spring. It was found that the ratios of 137 Cs/Al and Fe/Al could be used as indices for discriminating Asian dust from suspension of the local surface soil. Backward trajectory analysis suggested southern Mongolian and northeastern China regions as sources of the significant 137 Cs depositions

B- AND A-TYPE STARS IN THE TAURUS-AURIGA STAR-FORMING REGION

International Nuclear Information System (INIS)

Mooley, Kunal; Hillenbrand, Lynne; Rebull, Luisa; Padgett, Deborah; Knapp, Gillian

2013-01-01

We describe the results of a search for early-type stars associated with the Taurus-Auriga molecular cloud complex, a diffuse nearby star-forming region noted as lacking young stars of intermediate and high mass. We investigate several sets of possible O, B, and early A spectral class members. The first is a group of stars for which mid-infrared images show bright nebulae, all of which can be associated with stars of spectral-type B. The second group consists of early-type stars compiled from (1) literature listings in SIMBAD, (2) B stars with infrared excesses selected from the Spitzer Space Telescope survey of the Taurus cloud, (3) magnitude- and color-selected point sources from the Two Micron All Sky Survey, and (4) spectroscopically identified early-type stars from the Sloan Digital Sky Survey coverage of the Taurus region. We evaluated stars for membership in the Taurus-Auriga star formation region based on criteria involving: spectroscopic and parallactic distances, proper motions and radial velocities, and infrared excesses or line emission indicative of stellar youth. For selected objects, we also model the scattered and emitted radiation from reflection nebulosity and compare the results with the observed spectral energy distributions to further test the plausibility of physical association of the B stars with the Taurus cloud. This investigation newly identifies as probable Taurus members three B-type stars: HR 1445 (HD 28929), τ Tau (HD 29763), 72 Tau (HD 28149), and two A-type stars: HD 31305 and HD 26212, thus doubling the number of stars A5 or earlier associated with the Taurus clouds. Several additional early-type sources including HD 29659 and HD 283815 meet some, but not all, of the membership criteria and therefore are plausible, though not secure, members.

Life of a star

International Nuclear Information System (INIS)

Henbest, Nigel.

1988-01-01

The paper concerns the theory of stellar evolution. A description is given of:- how a star is born, main sequence stars, red giants, white dwarfs, supernovae, neutron stars and black holes. A brief explanation is given of how the death of a star as a supernova can trigger off the birth of a new generation of stars. Classification of stars and the fate of our sun, are also described. (U.K.)

Bioaccumulation of 137Cs and 60Co by Helianthus annuus

International Nuclear Information System (INIS)

Hornik, M.; Pipiska, M.; Vrtoch, L.; Augustin, J.; Lesny, J.

2005-01-01

The 60 Co and 137 Cs bioaccumulation by Helianthus annuus L. was measured during 9 day cultivation at 20 ± 2 o C in hydroponic Hoagland medium. Previous starvation for K + and for NH 4 + 2.2 and 2.7 times, respectively, enhanced 137 Cs uptake rate. Previous cultivation in surplus of K + ions 50 mmol·l -1 has no effect on 137 Cs bioaccumulation rate. Both 137 Cs and 60 Co bioaccumulation significantly increase with dilution of basic Hoagland medium up to 1:7 for caesium and up to 1:3 for cobalt followed by mild decrease at higher dilutions. Root to shoot specific 137 Cs radioactivity ratio (Bq.g -1 /Bq·g -1 , fresh wt.) increased with dilution from 1.46 to 9.6-9.8. The values root to shoot specific radioactivity ratio for 60 Co were less dependent on the nutrient concentrations and were within the range 5.7 to 8.5. 137 Cs was localized mainly in young leaves (30%) and roots (39%) and 60 Co mainly in roots (67%) and leaves (20%). Obtained data showed less sensitivity of 60 Co uptake by sunflower on nutrient concentration in hydroponic media. (author)

Radiochemical determination of 137Cs in foods

International Nuclear Information System (INIS)

Kastner, Geraldo F.; Ferreira, Andrea Vidal; Monteiro, Roberto P.G.

2013-01-01

A determination of radionuclides in food samples is important in commodities in order to attend to regulatory requirements for international trade. As a long-lived radioisotope of cesium, 137 Cs is produced as a result of human nuclear activities and than its contamination level evaluation among others radionuclides in foods is necessary. A methodology for the determination of 137 Cs in foods, pork and fish, is described. The procedures covered homogenization and freeze-drying of the samples. The 137 Cs was measured by gamma spectrometry using Canberra 50% HPGe detector. The counting was carried out with Monte Carlo software for detection conditions optimization including geometry and chemical data information. A certified sample, SRM IAEA-375, was analyzed in order to evaluate the reliability of the method, and the results showed good agreement between the measured and certified values. (author)

Behaviour of {sup 137}Cs in the Boreal forest ecosystem of central Sweden

Energy Technology Data Exchange (ETDEWEB)

Fawaris, B.H.

1995-12-31

Behaviour of Chernobyl fallout 1{sup 37}Cs in a coniferous forest ecosystem in central Sweden was investigated between 1990 and 1994. Results demonstrated that forest soil belongs to nutrient deficient type, and deposited fallout 1{sup 37}Cs from Chernobyl nuclear accident (CNA) was retained in the upper 5 cm of humic forest soil layer, with a venial migration deeper into soil profile. No correlation between forest soil exchangeable and total potassium (K{sup +}) and 1{sup 37}Cs transfer parameters was observed. However, addition of K{sup +}, found to efficiently reduce 1{sup 37}Cs uptake by sheep`s fescue and the addition of stable caesium (1{sup 33}Cs{sup +}) enhanced it. The addition of ammonium (NH{sub 4}{sup +}) was slightly stimulating the uptake of 1{sup 37}Cs by sheep`s fescue in the first cut only. Field plants showed a considerably reduction in their 1{sup 37}Cs activity concentrations. Relative to their 1{sup 37}Cs levels of 1986-89, a little reduction in heather occurred eight years after CNA. In contrast the reductions in lingonberry and bilberry were 87% and 68%, respectively. Three fractions of forest soil bound 1{sup 37}Cs were observed due to sequential extraction procedure (SEP). The first, is easily extractable 1{sup 37}Cs fraction, it comprises 22% of total forest soil 1{sup 37}Cs inventory in the upper 5 cm layer. The second, is soil organically and biologically bound 1{sup 37}Cs comprises about 30% of soil bound 1{sup 37}Cs. This fraction might be accounted for long-term soil available 1{sup 37}Cs for plant uptake after bio-degradation processes by soil microorganisms. The third, is the residual fraction, it comprises more than 35% of total forest soil 1{sup 37}Cs inventory, and may be associated with soil components which are probably of organic nature. Sorption of 1{sup 37}Cs by zeolite (Mordenite) revealed that soil bound 1{sup 37}Cs is to some extent more mobile in forest soils with high OM% and low pH than those with low OM%.

Behaviour of {sup 137}Cs in the Boreal forest ecosystem of central Sweden

Energy Technology Data Exchange (ETDEWEB)

Fawaris, B H

1996-12-31

Behaviour of Chernobyl fallout 1{sup 37}Cs in a coniferous forest ecosystem in central Sweden was investigated between 1990 and 1994. Results demonstrated that forest soil belongs to nutrient deficient type, and deposited fallout 1{sup 37}Cs from Chernobyl nuclear accident (CNA) was retained in the upper 5 cm of humic forest soil layer, with a venial migration deeper into soil profile. No correlation between forest soil exchangeable and total potassium (K{sup +}) and 1{sup 37}Cs transfer parameters was observed. However, addition of K{sup +}, found to efficiently reduce 1{sup 37}Cs uptake by sheep`s fescue and the addition of stable caesium (1{sup 33}Cs{sup +}) enhanced it. The addition of ammonium (NH{sub 4}{sup +}) was slightly stimulating the uptake of 1{sup 37}Cs by sheep`s fescue in the first cut only. Field plants showed a considerably reduction in their 1{sup 37}Cs activity concentrations. Relative to their 1{sup 37}Cs levels of 1986-89, a little reduction in heather occurred eight years after CNA. In contrast the reductions in lingonberry and bilberry were 87% and 68%, respectively. Three fractions of forest soil bound 1{sup 37}Cs were observed due to sequential extraction procedure (SEP). The first, is easily extractable 1{sup 37}Cs fraction, it comprises 22% of total forest soil 1{sup 37}Cs inventory in the upper 5 cm layer. The second, is soil organically and biologically bound 1{sup 37}Cs comprises about 30% of soil bound 1{sup 37}Cs. This fraction might be accounted for long-term soil available 1{sup 37}Cs for plant uptake after bio-degradation processes by soil microorganisms. The third, is the residual fraction, it comprises more than 35% of total forest soil 1{sup 37}Cs inventory, and may be associated with soil components which are probably of organic nature. Sorption of 1{sup 37}Cs by zeolite (Mordenite) revealed that soil bound 1{sup 37}Cs is to some extent more mobile in forest soils with high OM% and low pH than those with low OM%.

Constraining properties of high-density matter in neutron stars with magneto-elastic oscillations

Science.gov (United States)

Gabler, Michael; Cerdá-Durán, Pablo; Stergioulas, Nikolaos; Font, José A.; Müller, Ewald

2018-05-01

We discuss torsional oscillations of highly magnetized neutron stars (magnetars) using two-dimensional, magneto-elastic-hydrodynamical simulations. Our model is able to explain both the low- and high-frequency quasi-periodic oscillations (QPOs) observed in magnetars. The analysis of these oscillations provides constraints on the breakout magnetic-field strength, on the fundamental QPO frequency, and on the frequency of a particularly excited overtone. By performing a new set of simulations, we are able to derive for the first time empirical relations for a self consistent model including a superfluid core which describe these constraints quantitatively. We use these relations to generically constrain properties of high-density matter in neutron stars, employing Bayesian analysis. In spite of current uncertainties and computational approximations, our model-dependent Bayesian posterior estimates for SGR 1806-20 yield a magnetic-field strength \\bar{B}˜ 2.1^{+1.3}_{-1.0}× 10^{15} G and a crust thickness of Δ r = 1.6^{+0.7}_{-0.6} km, which are both in remarkable agreement with observational and theoretical expectations, respectively (1σ error bars are indicated). Our posteriors also favour the presence of a superfluid phase in the core, a relatively low stellar compactness, M/R star, and high shear speeds at the base of the crust, cs > 1.4 × 108 cm s-1. Although the procedure laid out here still has large uncertainties, these constraints could become tighter when additional observations become available.

Arbuscular mycorrhizal fungi mediated uptake of 137Cs in leek and ryegrass

International Nuclear Information System (INIS)

Rosen, Klas; Weiliang, Zhong; Maertensson, Anna

2005-01-01

In a first experiment of soil contaminated with 137 Cs, inoculation with a mixture of arbuscular mycorrhizae enhanced the uptake of 137 Cs by leek under greenhouse conditions, while no effect on the uptake by ryegrass was observed. The mycorrhizal infection frequency in leek was independent of whether the 137 Cs-contaminated soil was inoculated with mycorrhizal spores or not. The lack of mycorrhizae-mediated uptake of 137 Cs in ryegrass could be due to the high root density, which was about four times that of leek, or due to a less well functioning mycorrhizal symbiosis than of leek. In a second experiment, ryegrass was grown for a period of four cuts. Additions of fungi enhanced 137 Cs uptake of all harvests, improved dry weight production in the first cut, and also improved the mycorrhizal infection frequencies in the roots. No differences were obtained between the two fungal inoculums investigated with respect to biomass production or 137 Cs uptake, but root colonization differed. We conclude that, under certain circumstances, mycorrhizae affect plant uptake of 137 Cs. There may be a potential for selecting fungal strains that stimulate 137 Cs accumulation in crops. The use of ryegrass seems to be rather ineffective for remediation of 137 Cs-contaminated soil

Radioactive Cs in the estuary sediments near Fukushima Daiichi Nuclear Power Plant

International Nuclear Information System (INIS)

Yamasaki, Shinya; Imoto, Junpei; Furuki, Genki; Ochiai, Asumi; Ohnuki, Toshihiko; Sueki, Keisuke; Nanba, Kenji; Ewing, Rodney C.; Utsunomiya, Satoshi

2016-01-01

The migration and dispersion of radioactive Cs (mainly "1"3"4Cs and "1"3"7Cs) are of critical concern in the area surrounding the Fukushima Daiichi Nuclear Power Plant (FDNPP). Considerable uncertainty remains in understanding the properties and dynamics of radioactive Cs transport by surface water, particularly during rainfall-induced flood events to the ocean. Physical and chemical properties of unique estuary sediments, collected from the Kuma River, 4.0 km south of the FDNPP, were quantified in this study. These were deposited after storm events and now occur as dried platy sediments on beach sand. The platy sediments exhibit median particle sizes ranging from 28 to 32 μm. There is increasing radioactivity towards the bottom of the layers deposited; approximately 28 and 38 Bq g"−"1 in the upper and lower layers, respectively. The difference in the radioactivity is attributed to a larger number of particles associated with radioactive Cs in the lower part of the section, suggesting that radioactive Cs in the suspended soils transported by surface water has decreased over time. Sequential chemical extractions showed that ~ 90% of "1"3"7Cs was strongly bound to the residual fraction in the estuary samples, whereas 60 ~ 80% of "1"3"7Cs was bound to clays in the six paddy soils. This high concentration in the residual fraction facilitates ease of transport of clay and silt size particles through the river system. Estuary sediments consist of particles < 100 μm. Radioactive Cs desorption experiments using the estuary samples in artificial seawater revealed that 3.4 ± 0.6% of "1"3"7Cs was desorbed within 8 h. More than 96% of "1"3"7Cs remained strongly bound to clays. Hence, particle size is a key factor that determines the travel time and distance during the dispersion of "1"3"7Cs in the ocean. - Highlights: • Cs-137 of estuary sediment impacted by the FDNPP was measured. • Physical and chemical properties were measured also. • Increasing radioactivity was

Radioactive Cs in the estuary sediments near Fukushima Daiichi Nuclear Power Plant

Energy Technology Data Exchange (ETDEWEB)

Yamasaki, Shinya, E-mail: s-yamasaki@ied.tsukuba.ac.jp [Faculty of Pure and Applied Sciences and Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 (Japan); Imoto, Junpei; Furuki, Genki; Ochiai, Asumi [Department of Chemistry, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Ohnuki, Toshihiko [Advanced Science Research Center, Japan Atomic Energy Agency, Shirakata Shirane 2-4, Tokai, Ibaraki 319-1195 (Japan); Sueki, Keisuke [Faculty of Pure and Applied Sciences and Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 (Japan); Nanba, Kenji [Department of Environmental Management, Faculty of Symbiotic System Science, Fukushima University, Kanayagawa 1, Fukushima, 960-1296 (Japan); Ewing, Rodney C. [Department of Geological Sciences and Center for International Security and Cooperation, Stanford University, Stanford, CA 94305-2115 (United States); Utsunomiya, Satoshi [Department of Chemistry, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan)

2016-05-01

The migration and dispersion of radioactive Cs (mainly {sup 134}Cs and {sup 137}Cs) are of critical concern in the area surrounding the Fukushima Daiichi Nuclear Power Plant (FDNPP). Considerable uncertainty remains in understanding the properties and dynamics of radioactive Cs transport by surface water, particularly during rainfall-induced flood events to the ocean. Physical and chemical properties of unique estuary sediments, collected from the Kuma River, 4.0 km south of the FDNPP, were quantified in this study. These were deposited after storm events and now occur as dried platy sediments on beach sand. The platy sediments exhibit median particle sizes ranging from 28 to 32 μm. There is increasing radioactivity towards the bottom of the layers deposited; approximately 28 and 38 Bq g{sup −1} in the upper and lower layers, respectively. The difference in the radioactivity is attributed to a larger number of particles associated with radioactive Cs in the lower part of the section, suggesting that radioactive Cs in the suspended soils transported by surface water has decreased over time. Sequential chemical extractions showed that ~ 90% of {sup 137}Cs was strongly bound to the residual fraction in the estuary samples, whereas 60 ~ 80% of {sup 137}Cs was bound to clays in the six paddy soils. This high concentration in the residual fraction facilitates ease of transport of clay and silt size particles through the river system. Estuary sediments consist of particles < 100 μm. Radioactive Cs desorption experiments using the estuary samples in artificial seawater revealed that 3.4 ± 0.6% of {sup 137}Cs was desorbed within 8 h. More than 96% of {sup 137}Cs remained strongly bound to clays. Hence, particle size is a key factor that determines the travel time and distance during the dispersion of {sup 137}Cs in the ocean. - Highlights: • Cs-137 of estuary sediment impacted by the FDNPP was measured. • Physical and chemical properties were measured also. �

Understand B-type stars

Science.gov (United States)

1982-01-01

When observations of B stars made from space are added to observations made from the ground and the total body of observational information is confronted with theoretical expectations about B stars, it is clear that nonthermal phenomena occur in the atmospheres of B stars. The nature of these phenomena and what they imply about the physical state of a B star and how a B star evolves are examined using knowledge of the spectrum of a B star as a key to obtaining an understanding of what a B star is like. Three approaches to modeling stellar structure (atmospheres) are considered, the characteristic properties of a mantle, and B stars and evolution are discussed.

Behaviour of {sup 137} Cs in oxysoils and Goiania soil

Energy Technology Data Exchange (ETDEWEB)

Wassermann, Maria Angelica [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil)

1997-12-31

{sup 137} Cs soil-to-plant transfer factor obtained in oxy soils accidentally contaminated in Goiania and artificially contaminated shows that these soils present higher transfer when compared with data obtained under temperate climates. These differences were discussed in the light of pedology and geochemical partitioning. Some tropical soil characteristics as acidity, low available nutritive elements and low content of 2:1 clay type seems determine high availability for {sup 137} Cs. Results of sequential extraction showed {sup 137} Cs weakly bound to soil components and underline the importance of Fe oxides in the control of {sup 137} Cs availability in tropical climates. (author) 25 refs., 2 figs., 2 tabs.

Toxicity of injected 137CsCl in Beagle dogs. XVI

International Nuclear Information System (INIS)

Muggenburg, B.A.; Hahn, F.F.; Boecker, B.B.; Jones, R.K.; McClellan, R.O.; Pickrell, J.A.; Redman, H.C.

1983-01-01

Studies of the metabolism, dosimetry, and effects of intravenously administered 137 CsCl in the Beagle dog are being conducted to aid in assessing the biologic consequences of exposure to 137 Cs that might occur in the event of certain nuclear accidents. Effects of the chronic, relatively uniform whole-body exposures produced by 137 Cs are being compared with other diverse radiation dose patterns resulting from inhalation of radioactive aerosols. Fifty-four of the dogs that were injected with 237 CsCl have died, as have eight control dogs; four exposed and two control dogs died during the past year. Serial observations are continuing on the surviving four control dogs

Toxicity of injected 137CsCl in Beagle dogs. XVIII

International Nuclear Information System (INIS)

Muggenburg, B.A.; Hahn, F.F.; Boecker, B.B.; Jones, R.K.; McClellan, R.O.; Pickrell, J.A.

1984-01-01

Studies of the metabolism, dosimetry, and effects of intravenously administered 137 CsCl in the Beagle dog are being conducted to aid in assessing the biological consequences of exposure to 137 Cs that might occur in the event of certain nuclear accidents. Effects of the chronic, relatively uniform whole-body exposures produced by 137 CsCl are being compared with other diverse radiation dose patterns resulting from inhalation of radioactive aerosols. The fifty-four dogs that were injected with 137 CsCl have died, as have eleven control dogs; three control dogs died during the past year. Observations are continuing on the surviving control dog. 2 references, 2 figures, 1 table

Flare stars

International Nuclear Information System (INIS)

Nicastro, A.J.

1981-01-01

The least massive, but possibly most numerous, stars in a galaxy are the dwarf M stars. It has been observed that some of these dwarfs are characterized by a short increase in brightness. These stars are called flare stars. These flare stars release a lot of energy in a short amount of time. The process producing the eruption must be energetic. The increase in light intensity can be explained by a small area rising to a much higher temperature. Solar flares are looked at to help understand the phenomenon of stellar flares. Dwarfs that flare are observed to have strong magnetic fields. Those dwarf without the strong magnetic field do not seem to flare. It is believed that these regions of strong magnetic fields are associated with star spots. Theories on the energy that power the flares are given. Astrophysicists theorize that the driving force of a stellar flare is the detachment and collapse of a loop of magnetic flux. The mass loss due to stellar flares is discussed. It is believed that stellar flares are a significant contributor to the mass of interstellar medium in the Milky Way

Obsah Cs-137 v houbách

OpenAIRE

ČADOVÁ, Michaela

2015-01-01

The aim of this work is to compare the presence of Cs-137 in different kinds of mushrooms in selected locations using semiconductor gamma-ray spectrometry. Research question was determined: Does Cs-137 content amount vary depending on the fungal species? The first part deals with basic knowledge of ionizing radiation, which is important for the complex understanding of thematic problems. This concerns basic radiobiological terms such as radioactivity, ionizing radiation, its biological effect...

Foliar absorption and translocation of 137cs in egyptian olive plants

International Nuclear Information System (INIS)

Ramadan, A.A.; Maly, A.I.

1999-01-01

Foliar absorption and translocation of 137Cs by olive leaves were studied. Olive seedlings were transferred to the greenhouse in pots containing fine Nile silt.. Two seriies of pot experiments were conducted at the Nuclear Research Center site at Inshas. The treatments were conducted on leaves at the two middle nodes of the selected shoots. The lower surface of the olive leaf absorbed more 137Cs at the studied pH values as compared with the upper surface. The results show that changing the pH from 2 to 3 had no have any effect on the foliar absorption of 137Cs. Further increase of pH value caused the 137Cs foliar absorption to show a minimum at pH 5 then a maximum at pH 7. At pH 8 the foliar absorption of 137Cs started to decrease again. The concentration of translocated 137Cs was found to decrease gradually in the leaves above and below the treated ones. Absorption of 137Cs increased with time in the first 24 hours followed by lower absorption rates till the end of the experiment after 148 hours

By Draconis Stars

Science.gov (United States)

Bopp, Bernard W.

An optical spectroscopic survey of dK-M stars has resulted in the discovery of several new H-alpha emission objects. Available optical data suggest these stars have a level of chromospheric activity midway between active BY Dra stars and quiet dM's. These "marginal" BY Dra stars are single objects that have rotation velocities slightly higher than that of quiet field stars but below that of active flare/BY Dra objects. The marginal BY Dra stars provide us with a class of objects rotating very near a "trigger velocity" (believed to be 5 km/s) which appears to divide active flare/BY Dra stars from quiet dM's. UV data on Mg II emission fluxes and strength of transition region features such as C IV will serve to fix activity levels in the marginal objects and determine chromosphere and transition-region heating rates. Simultaneous optical magnetic field measures will be used to explore the connection between fieldstrength/filling-factor and atmospheric heating. Comparison of these data with published information on active and quiet dM stars will yield information on the character of the stellar dynamo as it makes a transition from "low" to "high" activity.

Variability in uptake of Cs isotopes by fenugreek plant from three soils

Energy Technology Data Exchange (ETDEWEB)

Pulhani, V; Dafauti, S; Dahiya, S; Hedge, A G [Environmental Studies Section, Health Physics Div., Bhabha Atomic Research Centre, Mumbai (India)

2008-07-01

Soil to plant transfer via root uptake is one of the major compartments in the radionuclide transfer pathways to man and can be used to assess the internal radiation dose via ingestion. The variability in the Transfer Factor (TF) of Cs isotopes was investigated in three different soils from nuclear power plant sites at Rajasthan and Narora with alkaline sandy loam alluvial and Madras with acidic coastal sandy loam alluvial soil. The soils were characterized for soil properties like texture, pH, EC, organic carbon, CaCO{sub 3} (%), CEC, silt, clay sand etc. and spiked with a mixture of 800 Bq {sup 137}Cs, 300 Bq {sup 134}Cs and 10mg of {sup 133}Cs (stable). Fenugreek (Trigonella foenum-graecum L.) from Leguminosae family an annual plant commonly used as a vegetable was grown in these soils to study the uptake of Cs. The uptake of heavy toxic elements like Pb, Cd, Ni, Cr etc. and nutrients Fe, Co, Cu, Zn, Mn, Ca, Mg, Na and K was also studied. The uptake of heavy toxic elements like Pb, Cd, Ni, Cr etc. and nutrients Fe, Co, Cu, Zn, Mn, Ca, Mg, Na and K was also studied. {sup 137}Cs and{sup 134}Cs was estimated using HPGe detector (15% Relative Efficiency, 54cc-coaxial, 2keV resolution at 1332keV of {sup 60}Co). Stable Cs, K and Na were determined by the Atomic Emission Spectrophotometry and Pb, Cd, Cr etc. by Atomic Absorption Spectrophotometry. Among the three soils the transfer factor for all the elements and Cs was highest for MAPS due to higher organic matter content and acidic pH followed by NAPS and RAPS. The {sup 137}Cs and {sup 134}Cs isotopes have been taken up to the same extent from soil and transfer factors are similar to each other. But the stable Cs uptake appears to be slightly high, probably because of excess of {sup 133}Cs (mg level) added as compared to the radioactive isotopes. In spite of this high difference in the soil concentrations of Cs isotopes, uptake of {sup 133}Cs is not very high indicating to a physiological limiting process for uptake

Radioecological studies of {sup 137}Cs in limnological ecosystems. {sup 137}Cs concentrations in water, sediment and biota at the lower region of the famous river in Saitama Prefecture

Energy Technology Data Exchange (ETDEWEB)

Miyake, Sadaaki; Motegi, Misako; Oosawa, Takashi; Nakazawa, Kiyoaki [Saitama Inst. of Public Health, Urawa (Japan); Ogata, Hiromitsu; Izumo, Yoshiro; Nakamura, Fumio

1996-02-01

The concentrations of {sup 137}Cs in water, sediment and biota at the lower region of the famous river in Saitama prefecture were determined in order to elucidate the radioecology of {sup 137}Cs in limnological ecosystems. {sup 137}Cs concentration in water was 0.10 mBq/l. {sup 137}Cs concentrations in sediment, shellfish, Sinotaia quadratus historica (mean for 2 detectable samples), and fish, Carassius auratus cuvieri (mean for 2 detectable samples), were about 6200, 840 and 320 times higher than the concentration of the water, respectively. But {sup 137}Cs radioactivity in the crustacea, Procambarus clarki, was significantly not detected. So, {sup 137}Cs transfer mechanism in the limnological ecosystems was indicated in part. (author).

Uptake and transfer factors of 137Cs by mushrooms

International Nuclear Information System (INIS)

Heinrich, G.

1991-01-01

The 137 Cs content of 118 species (668 samples) of higher fungi collected in the period from August 1984 to October 1989 at three different locations in Styria, Austria, was determined by gamma-spectrometry. The Cs-content of most mushrooms has been increasing since September 1986. In order to find out which factors determine the 137 Cs-contamination of mushrooms and the transfer-value soil to mushroom, the concentration of total and plant-available radiocesium in soils as well as the pH-value, the content of humus, clay, silt, sand, exchangeable cations, the composition of the clay minerals, and the particle size distribution of the soils of two different locations were examined. The higher the 137 Cs contamination of the soil, the thicker the layer of humus and the higher the content of humus, the lower the pH-value, and the lower the amount of essential cations, especially of K + , the higher the amount of 137 Cs plant-available will be. Therefore, the contamination of the mushrooms in the coniferous forest of Koralpenblick (1000 m) is higher than in the mixed forest at the Rosenberg around Graz at approx. 500 m height. Of 26 different species of mushrooms measured at both sites, only 61% show the highest TF-values soil to mushrooms also at the Koralpenblick. In the spruce forest at Koralpenblick there are many species of mushrooms with high 137 Cs-contamination which were not found at the Rosenberg. However, the properties of the species to which a mushroom belongs are more important than environmental conditions and soil properties. The transfer values of 40 K stay within narrow bounds, whereas those of 137 Cs differ widely. (orig.)

Uptake and activity concentration of 137Cs and 90Sr in Salix viminalis

International Nuclear Information System (INIS)

Rosen, K.; Fircks, Y. von; Sennerby-Forsse, L.

1999-01-01

In order to gain a better understanding of the uptake, internal distribution of 137 Cs and 90 Sr and the effects of K-fertilisation of uptake of 137 Cs in Salix plantations, a K-fertilisation experiment including 137 Cs, 90 Sr and 40 K was performed. Previous studies with K-fertilization in Sweden have mainly dealt with the flow of 137 Cs between soil to plant in annual crops. The aim of this study was study the transfer of 137 Cs, 90 Sr and 40 K from soil to plants and to test the following hypothesis: that accumulation of 137 Cs and 90 Sr differs between plant organs, that there is a seasonal variation in uptake and concentration of 137 Cs and 90 Sr and that the availability of K is related to the uptake of 137 Cs. (au)

Shooting stars

International Nuclear Information System (INIS)

Maurette, M.; Hammer, C.

1985-01-01

A shooting star passage -even a star shower- can be sometimes easily seen during moonless black night. They represent the partial volatilization in earth atmosphere of meteorites or micrometeorites reduced in cosmic dusts. Everywhere on earth, these star dusts are searched to be gathered. This research made one year ago on the Greenland ice-cap is this article object; orbit gathering projects are also presented [fr

The Vixen Star Book user guide how to use the star book ten and the original star book

CERN Document Server

Chen, James

2016-01-01

This book is for anyone who owns, or is thinking of owning, a Vixen Star Book Ten telescope mount or its predecessor. A revolution in amateur astronomy has occurred in the past decade with the wide availability of high tech, computer-driven, Go-To telescopes. Vixen Optics is leading the way by offering the Star Book Ten system, with its unique star map graphics software. The Star Book Ten is the latest version of computer telescope control using star map graphics as a user interface, first introduced in the original Star Book first offered in 2003. The increasingly complicated nature of this software means that learning to optimize this program is not straightforward, and yet the resulting views when all features are correctly deployed can be phenomenal. After a short history of computerized Go-To telescopes for the consumer amateur astronomer market, Chen offers a treasury of technical information. His advice, tips, and solutions aid the user in getting the most out of the Star Book Ten system in observing s...

STAR-TO-STAR IRON ABUNDANCE VARIATIONS IN RED GIANT BRANCH STARS IN THE GALACTIC GLOBULAR CLUSTER NGC 3201

International Nuclear Information System (INIS)

Simmerer, Jennifer; Ivans, Inese I.; Filler, Dan; Francois, Patrick; Charbonnel, Corinne; Monier, Richard; James, Gaël

2013-01-01

We present the metallicity as traced by the abundance of iron in the retrograde globular cluster NGC 3201, measured from high-resolution, high signal-to-noise spectra of 24 red giant branch stars. A spectroscopic analysis reveals a spread in [Fe/H] in the cluster stars at least as large as 0.4 dex. Star-to-star metallicity variations are supported both through photometry and through a detailed examination of spectra. We find no correlation between iron abundance and distance from the cluster core, as might be inferred from recent photometric studies. NGC 3201 is the lowest mass halo cluster to date to contain stars with significantly different [Fe/H] values.

Star-to-star Iron Abundance Variations in Red Giant Branch Stars in the Galactic Globular Cluster NGC 3201

Science.gov (United States)

Simmerer, Jennifer; Ivans, Inese I.; Filler, Dan; Francois, Patrick; Charbonnel, Corinne; Monier, Richard; James, Gaël

2013-02-01

We present the metallicity as traced by the abundance of iron in the retrograde globular cluster NGC 3201, measured from high-resolution, high signal-to-noise spectra of 24 red giant branch stars. A spectroscopic analysis reveals a spread in [Fe/H] in the cluster stars at least as large as 0.4 dex. Star-to-star metallicity variations are supported both through photometry and through a detailed examination of spectra. We find no correlation between iron abundance and distance from the cluster core, as might be inferred from recent photometric studies. NGC 3201 is the lowest mass halo cluster to date to contain stars with significantly different [Fe/H] values.

Radiogenotoxicological effect of signal nuclide 134Cs on somatic and germ cells

Institute of Scientific and Technical Information of China (English)

ZhuShou－Peng; XiaFen; 等

1997-01-01

Chromosome at aberation rates in bone marrow cells and micronucleus formation in bone marrow polychromatic erythrocytes both rise with increase in radioactivities of 134Cs,and can be fitted to power functions of radioactivities of 134Cs.In spermatogonia 134Cs mainly induced chromatid breakage,and abnormalities in sperm can also be experessed as power functions of radioactivities of 134 Cs.

137Cs distribution and geochemistry of Lena River (Siberia) drainage basin lake sediments

International Nuclear Information System (INIS)

Johnson-Pyrtle, A.; Scott, M.R.; Laing, T.E.; Smol, J.P.

2000-01-01

The Lena River is the second largest river that discharges into the Arctic Ocean. It is therefore important to determine not only the direct impact its discharge has on the 137Cs concentration of the Arctic, but also the potential its drainage basin has as a 137Cs source. 137Cs surface sediment concentrations and inventory values, which range from 4.97 to 338 Bq kg -1 and 357 to 1732 Bq m -2 , respectively, were determined for the Lena River drainage basin lake samples, via gamma analysis. The average geochemical and mineralogical composition of a subset of samples was also determined using neutron activation analysis, X-ray diffraction and X-ray fluorescence spectrometry techniques. Results of these geochemical analyses allowed for the identification of key geochemical factors that influence the distribution of 137Cs in the Lena River drainage basin. 137Cs profiles indicate that Lena River drainage basin lacustrine sediments serve as a record of 137Cs fallout. Based on the downcore 137Cs, %illite, %smectite, %Al and %Mn distribution patterns, it was concluded that a small fraction of non-selectively bound 137Cs was remobilized at depth in some cores. Inconsistencies between the actual 137Cs fallout record and the 137Cs profiles determined for the lake sediments were attributed to 137Cs remobilization in subsurface sediments. In addition to establishing the agreement between the global atmospheric fallout record and the downcore 137Cs distribution patterns determined for these sediments, results indicate that 137Cs deposited during periods of maximum atmospheric release was buried and is not susceptible to surface erosion processes. However, mean 137Cs concentrations of the lacustrine surface sediments (125 Bq kg -1 ) are still significantly higher than those of the nearby Lena River estuary (11.22 Bq kg -1 ) and Laptev Sea (6.00 Bq kg -1 ). Our study suggests that the Lena River drainage basin has the potential to serve as a source of 137Cs to the adjacent Arctic

Study of /sup 137/Cs absorption by Lemna minor

Energy Technology Data Exchange (ETDEWEB)

Bergamini, P G; Palmas, G; Piantelli, F; Sani, M [Siena Univ. (Italy). Ist. di Fisica; Banditelli, P; Previtera, M; Sodi, F

1979-09-01

Absorption of /sup 137/Cs by the floating aquatic plant Lemna minor in relation to /sup 137/Cs concentration in the water was measured under controlled conditions of temperature, pH and light. The method used to analyse the results is described. When applied to this study the method shows the influence on /sup 137/Cs absorption of (1) potassium-cesium exchange due to chemical affinity, (2) the natural colony growth of the organism and (3) the effect of light. Concentration factors were determined for these three processes.

The first stars: CEMP-no stars and signatures of spinstars

Science.gov (United States)

Maeder, André; Meynet, Georges; Chiappini, Cristina

2015-04-01

Aims: The CEMP-no stars are "carbon-enhanced-metal-poor" stars that in principle show no evidence of s- and r-elements from neutron captures. We try to understand the origin and nucleosynthetic site of their peculiar CNO, Ne-Na, and Mg-Al abundances. Methods: We compare the observed abundances to the nucleosynthetic predictions of AGB models and of models of rotating massive stars with internal mixing and mass loss. We also analyze the different behaviors of α- and CNO-elements, as well the abundances of elements involved in the Ne-Na and Mg-Al cycles. Results: We show that CEMP-no stars exhibit products of He-burning that have gone through partial mixing and processing by the CNO cycle, producing low 12C/13C and a broad variety of [C/N] and [O/N] ratios. From a 12C/13C vs. [C/N] diagram, we conclude that neither the yields of AGB stars (in binaries or not) nor the yields of classic supernovae can fully account for the observed CNO abundances in CEMP-no stars. Better agreement is obtained once the chemical contribution by stellar winds of fast-rotating massive stars is taken into account, where partial mixing takes place, leading to various amounts of CNO being ejected. The [(C+N+O)/H] ratios of CEMP-no stars vary linearly with [Fe/H] above [Fe/H] = -4.0 indicating primary behavior by (C+N+O). Below [Fe/H] = -4.0, [(C+N+O)/H] is almost constant as a function of [Fe/H], implying very high [(C+N+O)/Fe] ratios up to 4 dex. In view of the timescales, such abundance ratios reflect more individual nucleosynthetic properties, rather than an average chemical evolution. The high [(C+N+O)/Fe] ratios (as well as the high [(C+N+O)/α-elements]) imply that stellar winds from partially mixed stars were the main source of these excesses of heavy elements now observed in CEMP-no stars. The ranges covered by the variations of [Na/Fe], [Mg/Fe], and [Al/Fe] are much broader than for the α-elements (with an atomic mass number above 24) and are comparable to the wide ranges covered

Radioecological studies of {sup 137}Cs in limnological ecosystems. Accumulation and excretion of {sup 137}Cs in goldfish, Carassius auratus auratus, from diets

Energy Technology Data Exchange (ETDEWEB)

Miyake, Sadaaki; Motegi, Misako; Oosawa, Takashi; Nakazawa, Kiyoaki [Saitama Inst. of Public Health, Urawa (Japan); Ogata, Hiromitsu; Izumo, Yoshiro; Nakamura, Fumio

1996-06-01

Accumulation and excretion Of {sup 137}Cs in goldfish, Carassius auratus auratus, from radioactive diets (killifish, Oryzias latipes, meats accumulated {sup 137}Cs in the radioactive freshwater) or control diets (killifish meats mixed {sup 137}CsCl) were investigated in order to elucidate the accumulation mechanism of the radionuclide in natural living fishes. The accumulation of {sup 137}Cs, expressed in concentration ratio, in whole body of the fish showed a increasing tendency in proportion to the rearing time. On the other hand, the excretion of {sup 137}Cs, expressed in retention rate, in whole body rearing by administration of non-radioactive commercial diets after the accumulation above for 7 days, demonstrated a rapid decreasing at first few days, and followed a gradual decreasing tendency (the biological half lives were about 1.5 days and 52 days, respectively). As for the tissues and organs, higher accumulation and higher excretion were found in the viscera than those in the muscle. It is so suggested that the metabolic turnover rate of this radionuclide for the viscera is more rapid than that for the muscle. From the experimental results, it was confirmed that the relative contribution by ingestion of the radioactive diets in the accumulation of {sup 137}Cs in natural environmental fish was comparatively higher in comparison with uptake of the radionuclide in the radioactive freshwater. With regard to the difference between the radioactive diets and the control diets, the accumulation of {sup 137}Cs in whole body of the fish from the radioactive diets was less than that from the control diets to rearing 5 days, but afterward was not different. The difference of the accumulation between these diets will be attributable to that of the metabolic turnover between these diets. (author)

134Cs uptake by four plant species and Cs-K relations in the soil-plant system as affected by Ca(OH)2 application to an acid soil

International Nuclear Information System (INIS)

Massas, I.; Skarlou, V.; Haidouti, C.; Giannakopoulou, F.

2010-01-01

Three rates of Ca(OH) 2 were applied to an acid soil and the 134 Cs uptake by radish, cucumber, soybean and sunflower plants was studied. The 134 Cs concentration in all plant species was reduced from 1.6-fold in the sunflower seeds to 6-fold in the soybean vegetative parts at the higher Ca(OH) 2 rate. Potassium (K) concentration in plants was also reduced, but less effectively. The significantly decreased 134 Cs-K soil to plant distribution factors (D.F.) clearly suggest a stronger effect of soil liming on 134 Cs than on K plant uptake. This observation was discussed in terms of ionic interactions in the soil matrix and within the plants. The results also indicated that the increased Ca 2+ concentration in the exchange phase and in the soil solution along with the improved root activity, due to the soil liming, enhanced the immobilization of 134 Cs in the soil matrix and consequently lowered the 134 Cs availability for plant uptake.

Star Cluster Structure from Hierarchical Star Formation

Science.gov (United States)

Grudic, Michael; Hopkins, Philip; Murray, Norman; Lamberts, Astrid; Guszejnov, David; Schmitz, Denise; Boylan-Kolchin, Michael

2018-01-01

Young massive star clusters (YMCs) spanning 104-108 M⊙ in mass generally have similar radial surface density profiles, with an outer power-law index typically between -2 and -3. This similarity suggests that they are shaped by scale-free physics at formation. Recent multi-physics MHD simulations of YMC formation have also produced populations of YMCs with this type of surface density profile, allowing us to narrow down the physics necessary to form a YMC with properties as observed. We show that the shallow density profiles of YMCs are a natural result of phase-space mixing that occurs as they assemble from the clumpy, hierarchically-clustered configuration imprinted by the star formation process. We develop physical intuition for this process via analytic arguments and collisionless N-body experiments, elucidating the connection between star formation physics and star cluster structure. This has implications for the early-time structure and evolution of proto-globular clusters, and prospects for simulating their formation in the FIRE cosmological zoom-in simulations.

Toxicity of injected 137CsCl in beagle dogs. X

International Nuclear Information System (INIS)

Rebar, A.H.; Hanika-Rebar, C.; Benjamin, S.A.; Boecker, B.B.; Jones, R.K.; McClellan, R.O.; Pickrell, J.A.

1977-01-01

Studies on the metabolism, dosimetry and effects of intravenously administered 137 CsCl in the Beagle dog are being conducted to aid in assessing the biologic consequences of exposure to 137 Cs such as occurs in the event of certain nuclear accidents. Effects of the chronic, relatively uniform whole-body exposure produced by 137 Cs are being compared with other diverse radiation dose patterns resulting from inhalation of radioactive aerosols. Sixty-six dogs were entered into the study: six with a mean initial 137 Cs body burden of 3780 μCi/kg and five groups of 12 dogs each with mean initial 137 Cs body burdens of 2820, 1940, 1420, 970 and 0 μCi/kg. Eighteen of the dogs injected with 137 CsCl have died: 11 from 19 to 81 days after injection and cumulative whole-body doses of 860 to 1400 rads died with severe bone marrow damage and resultant pancytopenia; two at 2471 days and at 2707 days after injection and cumulative doses of 690 and 1800 rads with a neurofibrosarcoma of the liver and a mast cell tumor of the skin; five from 693 to 3162 days after injection and cumulative doses of 840 to 2000 rads with shock, aspiration pneumonia, severe arthritis, renal amyloidosis and congestive heart failure. Three control dogs died; one at 647 days with auto-immune hemolytic anemia, one at 2442 days with renal amyloidosis and one at 3088 days with disseminated complex mammary adenocarcinoma. Serial observations are continuing on the 36 137 CsCl dogs and nine control dogs. The 137 CsCl dogs now alive have cumulative whole-body doses of 550 to 2200 rads from 2777 to 3031 days after injection

Fission product behavior in high-temperature water: CsI vs MoO4

Science.gov (United States)

Kanjana, K.; Silva, K.; Channuie, J.

2017-09-01

Fission product behaviors of Cs, a major element released in a severe nuclear accident, still remain unclear. The question frequently addressed is whether Cs released will be in the form of Cs2MoO4 or CsOH. This is a challenging issue since it has been demonstrated that the reaction between Cs2MoO4 and water leading to CsOH production is thermodynamically favored. The present research aims at investigation of CsOH generation through this chemical channel. A high-temperature setup with a flow system based on the cooling system of a water-cooled nuclear reactor has been assembled. The reaction between aqueous solutions of CsI and Na2MoO4 in a high-corrosion-resistant hot cell (Hastelloy) has been studied up to 80 °C in deoxygenated system. The products have been characterized using FTIR and XRD. The results have shown that there is no reaction between CsI and Na2MoO4 under the experimental conditions.

Estimation on the origin and behavior of radioactive Cs in Natsui river basin

International Nuclear Information System (INIS)

Sato, Keisuke; Kikuchi, Ayaka; Tanahashi, Hiroshi

2013-01-01

In this study, we conducted a survey of radioactive Cs contained in soil, sediment, vegetation, and lakes and river water in the Natsui river basin, which was extensively contaminated by radioactive fallout from the nuclear accident. This study focuses on the runoff behavior, pollution level/scale and accumulation in soils/sediments of radioactive 134 Cs and 137 Cs. Half-life ratios of 134 Cs and 137 Cs were used to quantitatively evaluate the impact from the nuclear accident source. In addition, a model was created to reproduce and forecast the concentration of Cs and to predict long-term changes in water contamination levels in the Kodama-dam lake and its river inflow. In this study, a relatively high Cs concentration was detected in the lake and pond sediments with the Fukushima nuclear power plant estimated to be the source of more than 90% of the Cs contamination. From the results it was estimated that the Cs concentration in the Lake of Kodama dam was initially a few Bq/L, with an expected reduction to about 0.1 Bq/L in 10 years. (author)

Motion-blurred star acquisition method of the star tracker under high dynamic conditions.

Science.gov (United States)

Sun, Ting; Xing, Fei; You, Zheng; Wei, Minsong

2013-08-26

The star tracker is one of the most promising attitude measurement devices used in spacecraft due to its extremely high accuracy. However, high dynamic performance is still one of its constraints. Smearing appears, making it more difficult to distinguish the energy dispersive star point from the noise. An effective star acquisition approach for motion-blurred star image is proposed in this work. The correlation filter and mathematical morphology algorithm is combined to enhance the signal energy and evaluate slowly varying background noise. The star point can be separated from most types of noise in this manner, making extraction and recognition easier. Partial image differentiation is then utilized to obtain the motion parameters from only one image of the star tracker based on the above process. Considering the motion model, the reference window is adopted to perform centroid determination. Star acquisition results of real on-orbit star images and laboratory validation experiments demonstrate that the method described in this work is effective and the dynamic performance of the star tracker could be improved along with more identified stars and guaranteed position accuracy of the star point.

Study on movement, accumulation and distribution of 137Cs in rice and soils

International Nuclear Information System (INIS)

Lu Zixian; Xu Shiming

1992-11-01

The experiment of growing rice contaminated by 137 Cs solution shows that from the seedling stage to booting stage the absorption rate of 137 Cs is the highest, in the heading stage it is steady and in the milk stage goes to high again. The 137 Cs transfers from root to straw and ear, and from vegetative organs to reproductive organs. The relationship between specific activity (SA) and the amount of 137 Cs in soil is proportional. Only when the amount of 137 Cs in soil reaches to 370 Bq/g the SA of 137 Cs in rice rises remarkably. The different soil growing rice has different absorption rate of 137 Cs. Only in Shenzhen it is much higher than in other areas. The absorption of 137 Cs is also depending on different stage, in the milk stage it is considerably higher than other stages

Radiological Cs-137 accidents/incidents in Estonia

International Nuclear Information System (INIS)

Sinisso, Mark

1997-01-01

Two radiological accidents/incidents in Estonia are reported. The first -21 October 1994, three brothers entered the Tammiku repository and stole a radioactive Cs-137 source and received dangerous doses of radiation. The other incident (early 1995) involved an abandoned source - a discarded metal cylinder containing Cs-137. Chronologies and factual data are considered for both events. Concise descriptions of the incidents, a medical overview of the fate of injured people and lessons learned are presented

Radiological Cs-137 accidents/incidents in Estonia

Energy Technology Data Exchange (ETDEWEB)

Sinisso, Mark [Ministry of Foreign Affairs, Tallin (Estonia)

1997-12-31

Two radiological accidents/incidents in Estonia are reported. The first -21 October 1994, three brothers entered the Tammiku repository and stole a radioactive Cs-137 source and received dangerous doses of radiation. The other incident (early 1995) involved an abandoned source - a discarded metal cylinder containing Cs-137. Chronologies and factual data are considered for both events. Concise descriptions of the incidents, a medical overview of the fate of injured people and lessons learned are presented

On thermal expansion of RbD2PO4, CsH2PO4 and CsDrPO4 crystals

International Nuclear Information System (INIS)

Vlokh, O.G.; Shchur, Ya.I.; Klymiv, I.M.

1994-01-01

Thermal expansion of RbD 2 PO 4 , CsH 2 PO 4 , CsD 2 PO 4 crystals in a wide range of temperatures embracing points of phase transitions was studied. An explanation of anomalous behaviour of thermal expansion factor along directions b and c in the course of RbD 2 PO 4 transfer into intermediate phase was suggested. 10 refs., 4 figs

C/S data processing system and its application on DECnet

International Nuclear Information System (INIS)

Jin Zhigang; Shu Yantai

1997-01-01

Because of the rapid development of PC and LAN, C/S data processing paradigm became the main stream of distributed processing. For the family of VAX which running VMS operating system, in order to implement a C/S system, the authors must solve some problems and take efforts to implement inter-process communication between VAX and PC. The authors introduce how to construct a C/S system in the VAX-PC heterogeneous environment. The authors also describe the practical method by an example of the data processing system for fusion experiment. At last, the result of performance evaluation and comparison of the centralized processing and C/S system confirmed that the latter has some advantages

Baseline quantity of 131I, 137Cs, 134Cs and 40K in urinary excretions from Thai people and internal exposure dose

Science.gov (United States)

Peekhunthod, D.; Bangvirunrak, J.; Sansakon, S.; Nukultham, A.; Pukkhaw, T.

2017-06-01

Today, sealed and unsealed radioactive materials have been used in Thailand for various purposes such as medical, agricultural and industrial applications. There is a growing trend in the use of radioactive materials. Moreover, neighboring countries are planning to construct and operate nuclear power plants. In case of nuclear power plant accidents, radioactive releases in environment and intakes into human body by inhalation and ingestion causing long term health effects. This research aims to determine the radiation baseline quantity of interested relevant radionuclides such as 131I, 137Cs, 134Cs as well as a natural radionuclide, 40K in urine samples of Thai people by gamma spectrometry. Two types of detectors (NaI and HpGe detectors) are calibrated by mixed radionuclide standards of 109Cd, 57Co, 133Ba, 54Mn, 137Cs and 60Co, (energy range from 88 to 1,331 keV). 720 urine samples are collected over a 24 hour period from Thai volunteers with the age older than 18 years old, who lived in eight locations of Thailand. To reduce the effect of geometric difference, 30 ml of urine samples are prepared for counting measurement and efficiency determination. The radiation baseline quantity of 131I, 137Cs, 134Cs and 40K in 30 ml of urine samples are 0.37±0.09, 0.63±0.13, 0.39±0.08 and 7.84±1.63 Bq, respectively. Based on the assumption of intake (50% of the intake by ingestion and 50% of the intake by inhalation), internal dose for members of public are assessed. The committed dose equivalent due to an intake of 131I, 137Cs, 134Cs and 40K are 2.36E-03±1.66-03, 1.15E-01±8.61E-02, 1.16E-01±7.77E-02, 9.44E-01±3.56E-01 mSv per year, respectively.

Results of the radiological survey at 9 Redstone Lane, Lodi, New Jersey (LJ069)

International Nuclear Information System (INIS)

Foley, R.D.; Carrier, R.F.

1989-07-01

Maywood Chemical Works (MCW) of Maywood, New Jersey, generated process waste and residues associated with the production and refining of thorium and thorium compounds from monozite ores from 1916 to 1956. MCW supplied rare earth metals and thorium compounds to the Atomic Energy Commission and various other government agencies from the late 1940s to the mid-1950s. Areas residents used the sandlike waste from this thorium extraction process mixed with teas and cocoa leaves as mulch in their yards. Some of these contaminated wastes were also eroded from the site into Lodi Brook. At the request of the US Department of Energy (DOE), a group from Oak Ridge National Laboratory conducts investigate radiological surveys of properties in the vicinity of MCW to determine whether a property is contaminated with radioactive residues, principally 232 Th, derived from the MCW site. The survey typically includes direct measurement of gamma radiation levels and soil sampling for radionuclide analyses. The survey of this site, 9 Redstone Lane, Lodi, New Jersey (LJ069), was conducted during 1987. Measurements at the private property located at 9 Redstone Lane indicate slightly elevated gamma exposure rates in association with cinder-like material observed in logging holes. These elevated levels result from naturally occurring radioactivity present in such substances as ashes and cinders. They are not related to the deposit of residues from processing operations at the MCW site. All other radiological findings conform to the guidelines established by the DOE for the Maywood, New Jersey, area remedial action plan. 4 refs., 3 figs., 3 tabs

Performance Evaluation of the Sysmex CS-5100 Automated Coagulation Analyzer.

Science.gov (United States)

Chen, Liming; Chen, Yu

2015-01-01

Coagulation testing is widely applied clinically, and laboratories increasingly demand automated coagulation analyzers with short turn-around times and high-throughput. The purpose of this study was to evaluate the performance of the Sysmex CS-5100 automated coagulation analyzer for routine use in a clinical laboratory. The prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (APTT), fibrinogen (Fbg), and D-dimer were compared between the Sysmex CS-5100 and Sysmex CA-7000 analyzers, and the imprecision, comparison, throughput, STAT function, and performance for abnormal samples were measured in each. The within-run and between-run coefficients of variation (CV) for the PT, APTT, INR, and D-dimer analyses showed excellent results both in the normal and pathologic ranges. The correlation coefficients between the Sysmex CS-5100 and Sysmex CA-7000 were highly correlated. The throughput of the Sysmex CS-5100 was faster than that of the Sysmex CA-7000. There was no interference at all by total bilirubin concentrations and triglyceride concentrations in the Sysmex CS-5100 analyzer. We demonstrated that the Sysmex CS-5100 performs with satisfactory imprecision and is well suited for coagulation analysis in laboratories processing large sample numbers and icteric and lipemic samples.

Enhanced columnar structure in CsI layer by substrate patterning

Energy Technology Data Exchange (ETDEWEB)

Jing, T.; Cho, G.; Drewery, J.; Kaplan, S.N.; Mireshghi, A.; Perez-Mendez, V.; Wildermuth, D. [Lawrence Berkeley Lab., CA (United States); Fujieda, I. [Xerox Palo Alto Research Center, CA (United States)

1991-10-01

Columnar structure in evaporated CsI layers can be controlled by patterning substrates as well as varying evaporation conditions. Mesh-patterned substrates with various dimensions were created by spin-coating polyimide on glass or amorphous silicon substrates and defining patterns with standard photolithography technique. CsI(Tl) layers 200--1000 {mu}m were evaporated. Scintillation properties of these evaporated layers, such as light yield and speed, were equivalent to those of the source materials. Spatial resolution of X-ray detectors consisting of these layers and a linear array of X-ray detectors consisting of these layers and a linear array of Si photodiodes was evaluated by exposing them to a 25{mu}m narrow beam of X-ray. The results obtained with 200{mu}m thick CsI layers coupled to a linear photodiode array with 20 dots/mm resolution showed that the spatial resolution of CsI(Tl) evaporated on patterned substrates was about 75 {mu}m FWHM, whereas that on CsI(Tl) on flat substrates was about 230 {mu}m FWHM. Micrographs taken by SEM revealed that these layers retained the well-defined columnar structure originating from substrate patterns. Adhesion and light transmission of CsI(Tl) were also improved by patterning the substrate.

137Cs contamination of Techa river flood plain in Brodokalmak settlement

International Nuclear Information System (INIS)

Chesnokov, A.V.; Govorun, A.P.; Liksonov, V.I.; Shcherbak, S.B.; Ivanitskaya, M.V.

1999-01-01

137 Cs contamination of the Techa river flood plain inside the Brodokalmak settlement has been mapped. The collimated scintillated detector technique was used for 137 Cs deposit measurements. The 137 Cs contamination is very heterogeneous. A comparison of this technique with the traditional sample method was performed at selected locations. The sampling data are in good agreement with in-situ data. Soil surface activity of 90 Sr was determined from the samples. It was shown that 137 Cs contamination correlates with 90 Sr contamination within the flood plain of the settlement

Transfer of 137Cs to cows' milk in the Nordic countries

International Nuclear Information System (INIS)

Solheim Hansen, H.; Andersson, I.

1994-01-01

A comparison has been made of the transfer of Chernobyl derived 137 Cs cows' milk in the different Nordic countries. A compilation is given of data on 137 Cs levels in both dairy milk and milk from individual farms. In 1986 and 1987 the levels of 137 Cs were higest in Finland and Norway, intermediate in Sweden, the Faroe Islands and Iceland ( 137 Cs from global fallout only) and lowest in Denmark. The aggregated transfer coefficient (T a g) to cows' milk was 2-10 times higher in the Faroe Islands, Iceland and Norway compared to that in Denmark, Finland and Sweden for all years after 1986. The effective ecological half-life (T 1/2ecol ) for dairy cows' milk ranged from 1-2.3 y for all countries, except Iceland where the T 1/2ecol was 18.4 y (global fallout). It was therefore concluded that cows' milk production in the Faroe Islands and Norway was most sensitive to the Chernobyl 137 Cs fallout. Though milk production systems and management systems change over time and could alter the sensitivity to 137 Cs fallout, it is concluded that the Faroe Islands, Iceland and Norway would be most susceptible to future 137 Cs fallout. (orig.)

Retention of Cs on zeolite, bentonite and their mixtures

International Nuclear Information System (INIS)

Atun, G.

2002-01-01

The sorption behavior of cesium on zeolite and bentonite minerals and their mixtures was studied by means of a batch method and a tracer technique. All experiments were carried out in the presence of CsCl spiked with 137 Cs and NaCl as a supporting electrolyte in varying concentrations. The distribution coefficients (K D ) did not show significant differences at low Cs + loadings while they decreased in the high loading region. Freundlich and D-R isotherms were applied to the adsorption data of zeolite and bentonite. Adsorption capacities and mean energies calculated from D-R isotherm parameters decreased by increasing ionic strength on both minerals. The identification of the specific uptake sites was attempted on the basis of the Freundlich isotherm. Experimentally observed distribution coefficients of Cs on two mineral mixtures were smaller than theoretically calculated values, except at the highest NaCl concentration. (author)

137Cs in Finnish wild berries, mushrooms and game meat in 2000-2005

International Nuclear Information System (INIS)

Kostiainen, E.

2007-01-01

Activity concentrations of 137 Cs in wild berries, mushrooms and game meat were measured in samples collected during 2000-2005 in areas with varying 137 Cs deposition levels in Finland. Depending on the 137 Cs deposition levels in the sampling areas, the areal-mean activity concentrations of 137 Cs were 10-230 Bq kg -1 in wild berries, 20-240 Bq kg -1 in moose meat and 10-3000 Bq kg -1 in all mushroom species. Compared with the 137 Cs level of samples collected in 1986 in the corresponding areas, the reduction in the 137 Cs level was about one third for wild berries, equal to the rate of radioactive decay of 137 Cs. More reduction was observed in the activity concentrations of 137 Cs in moose meat, on average up to 50% since 1986. The aggregated transfer coefficients from soil to wild berries showed no change since 1986-1988, while there was about one third reduction in those from soil to game meat. (orig.)

Translocation, accumulation and distribution of 137Cs in spring wheat after foliage contamination

International Nuclear Information System (INIS)

Fan Zhongxue; Xu Shiming; Zhao Wenhu; Hou Lanxin; Li Xia

1995-05-01

The foliage absorption of 137 Cs by spring wheat and the accumulation and distribution of 137 Cs in non-contaminated parts of the plant were studied. The results showed that there was a linear relationship between the content of 137 Cs and the amount of the contamination in each part of the plant. The distribution of 137 Cs in each part of the plant was related with the phyllotaxis of the contaminated leaf, but the majority of 137 Cs in the ear was distributed in the husk. The accumulation of 137 Cs in non-contaminated leaves gradually decrease with the increasing of the relative phyllotaxy distance between non-contaminated leaves and the contaminated leaf. The order of the specific activity of 137 Cs is the leaf>the stem>the ear in the tillering. The translocation rate of 137 Cs to seeds is in direct proportion to physiological metabolic activity of the treated leaf and is also related to its phyllotaxis. (11 tabs., 4 figs.)

137Cs levels in deer following the Three Mile Island accident.

Science.gov (United States)

Field, R W

1993-06-01

White-tailed deer (Odocoileus virgianus) tongues were assayed to assess whether or not significant widespread 137Cs contamination occurred in the vicinity of Three Mile Island Nuclear Station as a result of the 1979 accident. White-tailed deer tongues harvested from 10 Pennsylvania counties more than 88 km away from Three Mile Island had significantly higher 137Cs levels than deer tongues harvested from counties surrounding the nuclear plant. The mean deer tongue 137Cs levels found in Pennsylvania white-tailed deer were lower than 137Cs levels found in deer from other parts of the U.S. sampled shortly after culmination of major atmospheric nuclear testing. These findings support the conclusions of previous studies suggesting that only minimal quantities of 137Cs escaped from the damaged Three Mile Island plant after the accident.

Comparative mode of action of novel hybrid peptide CS-1a and its rearranged amphipathic analogue CS-2a.

Science.gov (United States)

Joshi, Seema; Bisht, Gopal S; Rawat, Diwan S; Maiti, Souvik; Pasha, Santosh

2012-10-01

Cell selective, naturally occurring, host defence cationic peptides present a good template for the design of novel peptides with the aim of achieving a short length with improved antimicrobial potency and selectivity. A novel, short peptide CS-1a (14 residues) was derived using a sequence hybridization approach on sarcotoxin I (39 residues) and cecropin B (35 residues). The sequence of CS-1a was rearranged to enhance amphipathicity with the help of a Schiffer-Edmundson diagram to obtain CS-2a. Both peptides showed good antibacterial activity in the concentration range 4-16 μg·mL(-1) against susceptible as well as drug-resistant bacterial strains, including the clinically relevant pathogens Acenatobacter sp. and methicillin-resistant Staphylococcus aureus. The major thrust of these peptides is their nonhaemolytic activity against human red blood cells up to a high concentration of 512 μg·mL(-1). Compared to CS-1a, amphipathic peptide CS-2a showed a more pronounced α-helical conformation, along with a better membrane insertion depth in bacterial mimic 1,2-dipalmitoyl-sn-glycero-3-phosphocholine/1,2-dipalmitoyl-sn-glycero-3-phospho-(1'-rac-glycerol) small unilamellar vesicles. With equivalent lipid-binding affinity, the two peptides assumed different pathways of membrane disruption, as demonstrated by calcein leakage and the results of transmission electron microscopy on model bacterial mimic large unilamellar vesicles. Extending the work from model membranes to intact Escherichia coli cells, differences in membrane perturbation were visible in microscopic images of peptide-treated E. coli. The present study describes two novel short peptides with potent activity, cell selectivity and divergent modes of action that will aid in the future design of peptides with better therapeutic potential. © 2012 The Authors Journal compilation © 2012 FEBS.

Hemoglobin Constant Spring (Hb CS) Missed by HPLC in an Hb E Trait Pregnancy Resulting in Hb H-CS Disease in a Thai Girl: Utility of Capillary Electrophoresis.

Science.gov (United States)

Pornprasert, Sakorn; Saoboontan, Supansa; Wiengkum, Thanatcha

2016-06-01

Hemoglobin Constant Spring [Hb CS; α142, Term→Gln (TAA>CAA IN α2)] is often missed by routine laboratory testing, especially in subjects with co-inheritance of β-thalassemia or β-variants. We reported the case of a 1-year-old female with Hb H-CS disease who was born from a father with heterozygous of α-thalassemia-1 Southeast Asian type deletion and a mother with the combination of Hb CS and Hb E [β26 (B8) Glu→Lys, GAG>AAG] trait. A very tiny peak of Hb CS of the mother was easily ignored on the high performance liquid chromatography chromatogram while it was clearly seen on the capillary electrophoresis (CE) electrophoregram. Therefore, the CE is useful in screening for heterozygous Hb CS in a person with Hb E trait. This is of potential benefit for prevention of new cases of Hb H-CS disease.

Energy production in stars

International Nuclear Information System (INIS)

Bethe, Hans.

1977-01-01

Energy in stars is released partly by gravitation, partly by nuclear reactions. For ordinary stars like our sun, nuclear reactions predominate. However, at the end of the life of a star very large amounts of energy are released by gravitational collapse; this can amount to as much as 10 times the total energy released nuclear reactions. The rotational energy of pulsars is a small remnant of the energy of gravitation. The end stage of small stars is generally a white dwarf, of heavy stars a neutron star of possibly a black hole

Studies on the transport of fission products through food chains.3. Analysis of the relationship between 137Cs in cereal grain and137Cs deposited in 1964

International Nuclear Information System (INIS)

Eriksson, Aa.; Haak, E.; Karlstroem, F.

1976-01-01

REGRESSION ANALYSES WERE USED TO INVESTIGATE THE RELATIONSHIP BETWEEN THE 137 Cs content in grain and the deposition of 137 Cs during the months of Jun, Jul and Aug in 1964. Data from about half of the 400 yield survey districts in the country were available. The analyses gave coefficients which describe the influence of different monthly depositions of 137 Cs on the final 137 Cs content in grain under normal weather conditions. Coefficients were obtained for the different crops, one set for the Southern region and one for the Eastern and Western regions. In the Southern region the influence of the deposition in Jun on the 137 Cs content in grain was considerably larger than that of the deposition in July. The influence of the deposition in August was noticeable only in the grain of spring wheat. For the other regions the coefficients indicated about the same influence of the depositions in Jun and Jul on the 137 Cs content in grain of winter wheat. With regard to the spring-sown cereals, however, the transfer efficiency increased in the order: Jun 137 Cs deposited 3-6 per cent were recovered in grain in the southern region and 1.5-4 per cent in the other regions. (author)

Pyroelectric Study on Dipolar Alignment in 0.69Pb(Mg1/3Nb2/3)O3-0.31PbTiO3 Single Crystals

Institute of Scientific and Technical Information of China (English)

ZHAO Liang; SHEN Ming-Rong; CAO Wen-Wu

2012-01-01

Pyroelectric measurements are conducted during zero-Geld heating in [001], [110] and [111] poled 0.69Pb(Mg1/3 Nb2/3)O3-0.31PbTiO3 single crystals. Compared to the room-temperature-poled samples, the crystals poled by using the Rield cooling method show broad but well recognizable pyroelectric current peaks near 190℃, which is much higher than the Curie point (126℃) of the crystal. We propose that this peak of the crystals poled by field-cooling above the Curie point is ascribed to the order-disorder transition of the dipoles in polar nano-regions formed at the Burns temperature.%Pyroelectric measurements are conducted during zero-field heating in [001],[110] and [111] poled 0.69Pb(Mg1/3Nb2/3)O3-0.31PbTiO3 single crystals.Compared to the room-temperature-poled samples,the crystals poled by using the field cooling method show broad but well recognizable pyroelectric current peaks near 190℃,which is much higher than the Curie point (126℃) of the crystal.We propose that this peak of the crystals poled by field-cooling above the Curie point is ascribed to the order-disorder transition of the dipoles in polar nano-regions formed at the Burns temperature.

137Cs concentration distribution in among feeds and various soil types

International Nuclear Information System (INIS)

Csupka, S.

1980-01-01

The distribution of 137 Cs in four types of arable land and soil with grass cover (chernozem, serozem, gely soddy soil and meadow calcareous soil) is different. In arable land the penetration of 137 Cs into greater depths is higher than under the grasscover, where the main proportion of 137 Cs is retained by the upper layers in the depth of 0 to 5 cm. The only exception is gley soddy soil, where the upper layers allow the passage of radionuclides into greater depths. In the soil horizon to a depth of 50 cm out or the total content of 137 Cs from 16 to 47% is bound in exchangeable form and from 53 to 84% in a form available to plants according to the soil type. The relationship between exchangeable 137 Cs and that available to plants in soils is given by the coefficient of desorption and the relation between the 137 Cs content in the plant and in the soil is given by the coefficient of concentration. Their value varies within the range of 0.1 to 2.6. (author)