Chemical and spectrochemical production analysis of ThO2 and 233UO2-ThO2 pellets for the light water breeder reactor core for Shippingport (LWBR development program)

International Nuclear Information System (INIS)

Bukowski, J.F.; Hollis, E.D.

1975-06-01

The Bettis Atomic Power Laboratory has utilized wet chemical, emission spectrochemical, and mass spectrometric analytical techniques for the production analysis of the ThO 2 and 233 UO 2 -ThO 2 (1 to 6 wt percent 233 UO 2 ) pellets for the Light Water Breeder Reactor (LWBR) core for Shippingport. Proof of the fuel breeding concept necessitates measurement of precise and accurate chemical characterization of all fuel pellets before core life. Chemistry's efforts toward this goal are presented in three main sections: (1) general discussions relating the chemical requirements for ThO 2 and 233 UO 2 -ThO 2 core materials to the analytical capabilities, (2) technical discussions of the chemical and instrumental technology applied for the analysis of aluminum, boron, calcium, carbon, chloride plus bromide, chromium, cobalt, copper, dysprosium, europium, fluoride, gadolinium, iron, magnesium, manganese, mercury, molybdenum, nickel, nitrogen, samarium, silicon, titanium, vanadium, thorium, and uranium (total, trace, and uranium VI), and (3) a formal presentation of the analytical procedures as applied to the LWBR Development Program. (U.S.)

Innovative microstructures in ThO2-UO2 system

International Nuclear Information System (INIS)

Kutty, T.R.G.; Sengupta, A.K.; Majumdar, S.; Sah, D.N.; Kamath, H.S.

2005-01-01

The basic properties that really matter to the nuclear scientists are those that have greatest influence on microstructure: crystal structure, defects concentration and phase stability. The role of microstructure and crystal defects in determining the engineering properties are always acknowledged. Microstructure of nuclear fuels controls the in-pile fuel behavior like fission gas release, plasticity, in-pile creep and swelling. Conventional nuclear ceramic fabrication process consists of a number of stages, including calcination, milling, incorporating additives, pressing, drying and densification. Since each of these steps affects the microstructure of fuel pellets they must all be understood and a more holistic approach is required when processing nuclear ceramics compared to metals and polymers. It is possible to obtain a wide range of microstructures for ThO 2 -UO 2 system if a proper fabrication route is chosen. It is possible to tailor microstructure as per our requirement so that an improved behaviour during irradiation is expected. The improvement in plasticity and fission gas release can be attained by modifying the microstructure during fabrication. This paper deals with fabrication of ThO 2 -UO 2 pellets of varying U content and its characterization with the help of optical microscopy, XRD, SEM and EPMA. The microstructures are characterized in terms grain size, pore size and its distribution and homogeneity of uranium. (author)

Communication: theoretical study of ThO for the electron electric dipole moment search.

Science.gov (United States)

Skripnikov, L V; Petrov, A N; Titov, A V

2013-12-14

An experiment to search for the electron electric dipole moment (eEDM) on the metastable H(3)Δ1 state of ThO molecule was proposed and now prepared by the ACME Collaboration [http://www.electronedm.org]. To interpret the experiment in terms of eEDM and dimensionless constant kT, P characterizing the strength of the T,P-odd pseudoscalar-scalar electron-nucleus neutral current interaction, an accurate theoretical study of an effective electric field on electron, Eeff, and a parameter of the T,P-odd pseudoscalar-scalar interaction, WT, P, in ThO is required. We report our results for Eeff (84 GV/cm) and WT, P (116 kHz) together with the hyperfine structure constant, molecule frame dipole moment, and H(3)Δ1 → X(1)Σ(+) transition energy, which can serve as a measure of reliability of the obtained Eeff and WT, P values. Besides, our results include a parity assignment and evaluation of the electric-field dependence for the magnetic g factors in the Ω-doublets of H(3)Δ1.

Communication: Theoretical study of ThO for the electron electric dipole moment search

International Nuclear Information System (INIS)

Skripnikov, L. V.; Petrov, A. N.; Titov, A. V.

2013-01-01

An experiment to search for the electron electric dipole moment (eEDM) on the metastable H 3 Δ 1 state of ThO molecule was proposed and now prepared by the ACME Collaboration [ http://www.electronedm.org ]. To interpret the experiment in terms of eEDM and dimensionless constant k T, P characterizing the strength of the T,P-odd pseudoscalar–scalar electron–nucleus neutral current interaction, an accurate theoretical study of an effective electric field on electron, E eff , and a parameter of the T,P-odd pseudoscalar–scalar interaction, W T, P , in ThO is required. We report our results for E eff (84 GV/cm) and W T, P (116 kHz) together with the hyperfine structure constant, molecule frame dipole moment, and H 3 Δ 1 → X 1 Σ + transition energy, which can serve as a measure of reliability of the obtained E eff and W T, P values. Besides, our results include a parity assignment and evaluation of the electric-field dependence for the magnetic g factors in the Ω-doublets of H 3 Δ 1

Accumulation of the coumarin scopolin under abiotic stress conditions is mediated by the Arabidopsis thaliana THO/TREX complex

KAUST Repository

Döll, Stefanie

2017-12-09

Secondary metabolites are involved in the plant stress response. Among these are scopolin and its active form scopoletin, which are coumarin derivatives associated with reactive oxygen species scavenging and pathogen defence. Here we show that scopolin accumulation can be induced in the root by osmotic stress and in the leaf by low-temperature stress in Arabidopsis thaliana. A genetic screen for altered scopolin levels in A. thaliana revealed a mutant compromised in scopolin accumulation in response to stress; the lesion was present in a homologue of THO1 coding for a subunit of the THO/TREX complex. The THO/TREX complex contributes to RNA silencing, supposedly by trafficking precursors of small RNAs. Mutants defective in THO, AGO1, SDS3 and RDR6 were impaired with respect to scopolin accumulation in response to stress, suggesting a mechanism based on RNA silencing such as the trans-acting small interfering RNA pathway, which requires THO/TREX function.

Combined 4-component and relativistic pseudopotential study of ThO for the electron electric dipole moment search.

Science.gov (United States)

Skripnikov, L V

2016-12-07

A precise theoretical study of the electronic structure of heavy atom diatomic molecules is of key importance to interpret the experiments in the search for violation of time-reversal (T) and spatial-parity (P) symmetries of fundamental interactions in terms of the electron electric dipole moment, eEDM, and dimensionless constant, k T,P , characterizing the strength of the T,P-odd pseudoscalar-scalar electron-nucleus neutral current interaction. The ACME collaboration has recently improved limits on these quantities using a beam of ThO molecules in the electronic H 3 Δ 1 state [J. Baron et al., Science 343, 269 (2014)]. We apply the combined direct relativistic 4-component and two-step relativistic pseudopotential/restoration approaches to a benchmark calculation of the effective electric field, E eff , parameter of the T,P-odd pseudoscalar-scalar interaction, W T,P , and hyperfine structure constant in Δ13 state of the ThO molecule. The first two parameters are required to interpret the experimental data in terms of the eEDM and k T,P constant. We have investigated the electron correlation for all of the 98 electrons of ThO simultaneously up to the level of the coupled cluster with single, double, and noniterative triple amplitudes, CCSD(T), theory. Contributions from iterative triple and noniterative quadruple cluster amplitudes for the valence electrons have been also treated. The obtained values are E eff = 79.9 GV/cm, W T,P = 113.1 kHz. The theoretical uncertainty of these values is estimated to be about two times smaller than that of our previous study [L. V. Skripnikov and A. V. Titov, J. Chem. Phys., 142, 024301 (2015)]. It was found that the correlation of the inner- and outer-core electrons contributes 9% to the effective electric field. The values of the molecule frame dipole moment of the Δ13 state and the H 3 Δ 1 →X 1 Σ + transition energy of ThO calculated within the same methods are in a very good agreement with the experiment.

Dr.LiTHO: a development and research lithography simulator

Science.gov (United States)

Fühner, Tim; Schnattinger, Thomas; Ardelean, Gheorghe; Erdmann, Andreas

2007-03-01

This paper introduces Dr.LiTHO, a research and development oriented lithography simulation environment developed at Fraunhofer IISB to flexibly integrate our simulation models into one coherent platform. We propose a light-weight approach to a lithography simulation environment: The use of a scripting (batch) language as an integration platform. Out of the great variety of different scripting languages, Python proved superior in many ways: It exhibits a good-natured learning-curve, it is efficient, available on virtually any platform, and provides sophisticated integration mechanisms for existing programs. In this paper, we will describe the steps, required to provide Python bindings for existing programs and to finally generate an integrated simulation environment. In addition, we will give a short introduction into selected software design demands associated with the development of such a framework. We will especially focus on testing and (both technical and user-oriented) documentation issues. Dr.LiTHO Python files contain not only all simulation parameter settings but also the simulation flow, providing maximum flexibility. In addition to relatively simple batch jobs, repetitive tasks can be pooled in libraries. And as Python is a full-blown programming language, users can add virtually any functionality, which is especially useful in the scope of simulation studies or optimization tasks, that often require masses of evaluations. Furthermore, we will give a short overview of the numerous existing Python packages. Several examples demonstrate the feasibility and productiveness of integrating Python packages into custom Dr.LiTHO scripts.

Neutronics characteristics of micro-heterogeneous ThO2-UO2 PWR cores

International Nuclear Information System (INIS)

Zhao, X.; Driscoll, M.J.; Kazimi, S.

2001-01-01

A new fuel concept, axially-micro-heterogeneous ThO 2 -UO 2 fuel, where ThO 2 fuel pellets and UO 2 fuel pellets are stacked in separate layers in the fuel rods, is being studied at MIT as an option to reduce plutonium production in LWR fuel. Very interesting neutronic behavior is observed: (1) A reactivity increase of 3% to 4% at EOL for a given 235 U inventory which results in a 20-30% increase in average core discharge burnup; (2) For certain configurations, a ''burnable poison'' effect is observed. Analysis shows that these effects are achieved due to a combination of changes in self-shielding, local fissile worth, and conversion ratio, among which self-shielding is the dominant effect at the end of a reactivity-limited burnup. Other variations of micro-heterogeneous UO 2 -ThO 2 fuel including duplex pellets, checkerboard pin distribution, and checkerboard-axial combinations have also been investigated, and their neutronic performance compared. It is concluded that the axial fuel micro-heterogeneity provides the largest gain in reactivity-limited burnup. (author)

Densification kinetics and microstructure of ThO2 pellets

International Nuclear Information System (INIS)

Kutty, T.R.G.; Khan, K.B.; Hegde, P.V.; Banerjee, J.; Jarvis, T.; Sengupta, A.K.; Majumdar, S.; Kamath, H.S.

2004-01-01

Several reactor concepts based on thorium fuel cycles are under study since thorium is much more abundant than uranium. In this paper, the sintering activation energy of ThO 2 pellet doped with 0.5% CaO was determined by constant heating rate method

Preparation of ThO2 sols suitable for gelation into microspheres in CCl4-ammonia media

International Nuclear Information System (INIS)

Yamagishi, Shigeru; Takahashi, Yoshihisa

1985-01-01

Production conditions of ThO 2 sols are studied for satisfactorily gelling them into microspheres in CCl 4 -ammonia media, which result gel-spheres with good sphericities but need high-quality source-sols for crackfree gelation. Two-stage pH-setting techniques were added to the previously reported method, which had been developed to produce ThO 2 sols suitable for gelation in hexone-ammonia media and was characterized by preneutralization followed by neutralization under pH-control. As a result, colloid fractions of Th in sols were increased without decreasing colloid size. This enabled one to obtain crackfree, large, spherical ThO 2 particles by gelation in the CCl 4 -ammonia media. (author)

Thermal defect annealing of swift heavy ion irradiated ThO2

Science.gov (United States)

Palomares, Raul I.; Tracy, Cameron L.; Neuefeind, Joerg; Ewing, Rodney C.; Trautmann, Christina; Lang, Maik

2017-08-01

Isochronal annealing, neutron total scattering, and Raman spectroscopy were used to characterize the structural recovery of polycrystalline ThO2 irradiated with 2-GeV Au ions to a fluence of 1 × 1013 ions/cm2. Neutron diffraction patterns show that the Bragg signal-to-noise ratio increases and the unit cell parameter decreases as a function of isochronal annealing temperature, with the latter reaching its pre-irradiation value by 750 °C. Diffuse neutron scattering and Raman spectroscopy measurements indicate that an isochronal annealing event occurs between 275-425 °C. This feature is attributed to the annihilation of oxygen point defects and small oxygen defect clusters.

Associations between Dengue Hospitalizations and Climate in Can Tho, Vietnam, 2001-2011

Directory of Open Access Journals (Sweden)

Nguyen P. Toai

2016-07-01

Full Text Available In Vietnam, dengue fever is a major cause of hospitalization with over one million cases reported between 1991 and 2004. Changes in the incidence of dengue in Can Tho city due to increased temperature and changes in precipitation, are anticipated. In an effort to better characterize the relationship between climate and dengue, we examine the associations between weather variables and dengue hospitalizations in Can Tho between 2001 and 2011. Monthly data on hospitalized dengue cases and means of temperature, rainfall and humidity were recorded from 2001 to 2011. We used the Box-Jenkins approach to modelling of time series to assess the association between these factors. This model was validated by the Portmanteau test. Our results revealed that the highest dengue incidences in Can Tho occur between July and December. After adjusting for seasonality, the rate of dengue hospitalizations was significantly associated with relative humidity with a lag of one month. Rainfall and temperature were not predictors of dengue hospitalization rate. In conclusion, these data suggest that maximum relative humidity (with a one month lag is an important determinant of dengue hospitalizations. Enhanced vector control during months with high humidity may be an important approach to prevent dengue transmission.

Comparison of sensory characteristics of green tea in Thai Nguyen and Phu Tho, Vietnam

OpenAIRE

Dang, Thi Minh Luyen; Ha, Duyen Tu; Lebailly, Philippe; Nguyen, Duy Thinh; Tu, Viet Phu

2013-01-01

Green tea is a popular consumption product in Vietnam. Especially, tea which origins from Tan Cuong, Thai Nguyen has been known for long by its better quality than those coming from other regions on the country. The study aims at comparing and finding out if the difference between tea in Thai Nguyen and Phu Tho can be figured by sensory tasting. Two products picked from Tan Cuong, Thai Nguyen province and two others from Phu Ho district, Phu Tho are were evaluated by a panel of twelve judg...

Communication: Theoretical study of ThO for the electron electric dipole moment search

Energy Technology Data Exchange (ETDEWEB)

Skripnikov, L. V., E-mail: leonidos239@gmail.com; Petrov, A. N.; Titov, A. V. [Federal State Budgetary Institute “Petersburg Nuclear Physics Institute,” Gatchina, Leningrad district 188300 (Russian Federation); Department of Physics, Saint Petersburg State University, Saint Petersburg, Petrodvoretz 198904 (Russian Federation)

2013-12-14

An experiment to search for the electron electric dipole moment (eEDM) on the metastable H{sup 3}Δ{sub 1} state of ThO molecule was proposed and now prepared by the ACME Collaboration [ http://www.electronedm.org ]. To interpret the experiment in terms of eEDM and dimensionless constant k{sub T,} {sub P} characterizing the strength of the T,P-odd pseudoscalar–scalar electron–nucleus neutral current interaction, an accurate theoretical study of an effective electric field on electron, E{sub eff}, and a parameter of the T,P-odd pseudoscalar–scalar interaction, W{sub T,} {sub P}, in ThO is required. We report our results for E{sub eff} (84 GV/cm) and W{sub T,} {sub P} (116 kHz) together with the hyperfine structure constant, molecule frame dipole moment, and H{sup 3}Δ{sub 1} → X{sup 1}Σ{sup +} transition energy, which can serve as a measure of reliability of the obtained E{sub eff} and W{sub T,} {sub P} values. Besides, our results include a parity assignment and evaluation of the electric-field dependence for the magnetic g factors in the Ω-doublets of H{sup 3}Δ{sub 1}.

Determination of the cationic self-diffusion coefficient in ThO2-5%UO2 nuclear fuel

International Nuclear Information System (INIS)

Sabioni, A.C.S.

1984-01-01

The cation self-diffusion coefficient for the ThO 2 -5%UO 2 by means of the densification model developed by Assmann and Stehle was determined. The experimental data of the fuel densification, used in the calculations, were obtained from thermal resinter tests. Our result is comparable to previously published values for U and Th diffusion in polycrystalline ThO 2 and (Th, U)O 2 . (Author) [pt

Dominant lethals following administration of tritium (THO) to rat males

International Nuclear Information System (INIS)

Yagova, A.; Baev, I.; Bajrakova, A.

1976-01-01

Adult rat males were given a single intraperitoneal tritium (THO) injection at 0,01 or 0,001 mCi/g body weight (1/100 or 1/1000 of LDsub(50/30), respectively). Twelve days after treatment each male was mated to 3-5 intact females, and the latter were replaced by fresh ones every 12 following days over a 120-day period. Mated females were killed to score conceptions, corpora lutea, and live and dead embryos. Estimations were made of F 1 prenatal death rate (according to Bateman, 1958) and the frequency of induction of dominant lethal mutations (according to Roehrborn, 1970). The results observed indicated paternal exposure to tritium (THO) to produce dominant lethals both in pre- and post-meiotic germ cells in the rat. The extent of the genetic damage studied was found to depend on the amount of activity administered as well as on the time interval between treatment and conception. (author)

Fission gas release and grain growth in THO2-UO2 fuel irradiated at high temperature

International Nuclear Information System (INIS)

Goldberg, I.; Waldman, L.A.; Giovengo, J.F.; Campbell, W.R.

1979-01-01

Data are presented on fission gas release and grain growth in ThO 2 -UO 2 fuels irradiated as part of the LWBR fuel element development program. These data for rods that experienced peak linear power outputs ranging from 15 to 22 KW/ft supplement fission gas release data previously reported for 51 rods containing ThO 2 and ThO 2 -UO 2 fuel irradiated at peak linear powers predominantly below 14 KW/ft. Fission gas release was relatively high (up to 15.0 percent) for the rods operated at high power in contrast to the relatively low fission gas release (0.1 to 5.2 percent) measured for the rods operated at lower power. Metallographic examination revealed extensive equiaxed grain growth in the fuel at the high power axial locations of the three rods

Thermally stimulated depolarization currents in ThO2

International Nuclear Information System (INIS)

Campos, L.L.

1979-01-01

Thermally Stimulated Depolarization Currents (TSDC) have been detected in polycrystalline samples of ThO 2 in the temperature range 100K - 350K. The induced polarization is found to be due to migration of charge carriers over microscopic distances with trapping at grain boundaries. Moreover the density of charges carriers released from trapping sites, upon heating the cooled previously dc biased specimen, decreases for increasing sintering temperature, suggesting the use of the technique to the study of grain growth in the bulk of ceramic nuclear oxides [pt

Influence of organic matter on the solubility of ThO2 and geochemical modeling

International Nuclear Information System (INIS)

Liu Dejun; Luo Tian; Maes, N.; Bruggeman, C.

2014-01-01

Thorium (IV) is widely considered in laboratory experiments as a suitable chemical analogue for long-lived tetravalent actinides. Th (IV) is redox-insensitive, as an analogue for U (IV) to study the influence of natural organic matter on the solubility. The solubility of crystalline ThO 2 (cr) has been measured under geochemical conditions representative for the Boom Clay using Real Boom Clay Water containing organic matter to assess its influence on the ThO 2 (cr) solubility. For the purpose of comparison, Aldrich Humic Acid was also investigated. Solubility measurements of ThO 2 (cr) were approached from under-saturation in an anaerobic glove box with a controlled Ar0.4%CO 2 atmosphere. Th concentration is determined after 30000 MWCO, 300000 MWCO, and 0.45 μm filtration to distinguish solid (0.45 μm), larger colloids (300000 MWCO), and small dissolved species(30000 MWCO). X-ray diffraction was carried out to investigate the transformation of ThO 2 (cr) phase during the contact with Boom Clay Water. In Synthetic Boom Clay Water (without organic matter) the concentrations of Th (IV) are 5 × l0 -ll mol/L, 4 × lO -10 mol/L, and 8 × lO -8 mol/L after 30000 MWCO, 300000 MWCO, and 0. 45 μm filtration, respectively. It indicated the existence of inorganic colloids in solution. The increase of the total Th solution concentration with increasing organic matter concentration revealed a complexation-like interaction between Th and organic matter. All the experimental data could be modeled by Tipping humic ion-binding model VI using a combination of solubility calculations and complexation reactions between Th (IV) and organic matter functional groups. Similar to the investigation of Eu 3+ solubility, the affinity of organic matter for Th was higher for Aldrich humic acid compared to Boom Clay organic matter. However, Boom Clay organic matter with different size had the similar complexation affinity with Th (IV). (authors)

Migration of THO and Np in a fractured granite core at deep underground laboratory

International Nuclear Information System (INIS)

Park, Chung Kyun; Cho, Won Zin; Hahn, Pil Soo; Kienzler, B.

2005-01-01

Migration experiments of THO and 237Np have performed through a sampled granite core in Chemlab2 probe at the Aspo hard Rock laboratory. The elution curves of THO were analysed to determine hydraulic properties such as the extent of dispersion effect according to flow rates. The retardation phenomena of the solutes were observed and described with elution curves and migration plumes. After migration test, the rock core was opened, and the remaining radioactivities on the rock fracture surfaces were measured. The transport process was simulated with a two-dimensional channel model. The mass transport process was described with three types of basic processes: advection, sorption and matrix diffusion. By the combination of these processes, effects of each process on transport were described in terms of elution curves and migration plumes. By comparing the simulation results to the experimental one, it was possible to analyse the retardation effect quantitatively

Microspheres of UO2, ThO2 and PuO2 for the high temperature reactor

International Nuclear Information System (INIS)

Brandau, T.; Brandau, E.

2010-01-01

Up to the end of the eighties of last century, the so called ''Kernels'', microspheres with a diameter of about 300 μm as sintered out of ThO 2 and UO 2 have been produced by a special vibrational dropping process. After coating and embedding in carbon the pebble fuel balls with a diameter of 60 mm included 40.000 UO 2 - or ThO 2 -microspheres in the core. Since the early nineties BRACE is developing the processing of microspheres with a broad range of materials for applications in chemical, pharmaceutical, electronic, cosmetic and food industries. One of the developing areas is the production of microspheres out of metal oxides, where different processes as sol-gel-, suspension- or mixed processes are used. (orig.)

Modeling fission gas release in high burnup ThO2-UO2 fuel

International Nuclear Information System (INIS)

Long, Y.; Yuan, Y.; Pilat, E.E.; Rim, C.S.; Kazimi, M.S.

2001-01-01

A preliminary fission gas release model to predict the performance of thoria fuel using the FRAPCON-3 computer code package has been formulated. The following modeling changes have been made in the code: - Radial power/burnup distribution; - Thermal conductivity and thermal expansion; - Rim porosity and fuel density; - Diffusion coefficient of fission gas in ThO 2 -UO 2 fuel and low temperature fission gas release model. Due to its lower epithermal resonance absorption, thoria fuel experiences a much flatter distribution of radial fissile products and radial power distribution during operation as compared to uranian fuel. The rim effect and its consequences in thoria fuel, therefore, are expected to occur only at relatively high burnup levels. The enhanced conductivity is evident for ThO 2 , but for a mixture the thermal conductivity enhancement is small. The lower thermal fuel expansion tends to negate these small advantages. With the modifications above, the new version of FRAPCON-3 matched the measured fission gas release data reasonably well using the ANS 5.4 fission gas release model. (authors)

Fabrication of ThO2, UO2, and PuO2-UO2 pellets

International Nuclear Information System (INIS)

Rasmussen, D.E.; Jentzen, W.R.; McCord, R.B.

1978-01-01

Fabrication of ThO pellets for EBR-II irradiation testing and fabrication of UO 2 and PuO 2 -UO 2 pellets for United Kingdom Prototype Fast Reactor (PFR) irradiation testing is discussed. Effect of process parameters on density and microstructure of pellets fabricated by the cold press and sinter technique is reviewed

Theoretical study of thorium monoxide for the electron electric dipole moment search: electronic properties of H(3)Δ(1) in ThO.

Science.gov (United States)

Skripnikov, L V; Titov, A V

2015-01-14

Recently, improved limits on the electron electric dipole moment, and dimensionless constant, kT,P, characterizing the strength of the T,P-odd pseudoscalar-scalar electron-nucleus neutral current interaction in the H(3)Δ1 state of ThO molecule were obtained by the ACME collaboration [J. Baron et al., Science 343, 269 (2014)]. The interpretation of the experiment in terms of these fundamental quantities is based on the results of theoretical study of appropriate ThO characteristics, the effective electric field acting on electron, Eeff, and a parameter of the T,P-odd pseudoscalar-scalar interaction, WT,P, given in Skripnikov et al. [J. Chem. Phys. 139, 221103 (2013)] by St. Petersburg group. To reduce the uncertainties of the given limits, we report improved calculations of the molecular state-specific quantities Eeff, 81.5 GV/cm, and WT,P, 112 kHz, with the uncertainty within 7% of the magnitudes. Thus, the values recommended to use for the upper limits of the quantities are 75.8 GV/cm and 104 kHz, correspondingly. The hyperfine structure constant, molecule-frame dipole moment of the H(3)Δ1 state, and the H(3)Δ1 → X(1)Σ(+) transition energy which, in general, can serve as a measure of reliability of the obtained Eeff and WT,P values are also calculated. In addition, we report the first calculation of g-factor for the H(3)Δ1 state of ThO. The results are compared to the earlier experimental and theoretical studies, and a detailed analysis of uncertainties of the calculations is given.

Bond energies of ThO+ and ThC+: A guided ion beam and quantum chemical investigation of the reactions of thorium cation with O2 and CO

Science.gov (United States)

Cox, Richard M.; Citir, Murat; Armentrout, P. B.; Battey, Samuel R.; Peterson, Kirk A.

2016-05-01

Kinetic energy dependent reactions of Th+ with O2 and CO are studied using a guided ion beam tandem mass spectrometer. The formation of ThO+ in the reaction of Th+ with O2 is observed to be exothermic and barrierless with a reaction efficiency at low energies of k/kLGS = 1.21 ± 0.24 similar to the efficiency observed in ion cyclotron resonance experiments. Formation of ThO+ and ThC+ in the reaction of Th+ with CO is endothermic in both cases. The kinetic energy dependent cross sections for formation of these product ions were evaluated to determine 0 K bond dissociation energies (BDEs) of D0(Th+-O) = 8.57 ± 0.14 eV and D0(Th+-C) = 4.82 ± 0.29 eV. The present value of D0 (Th+-O) is within experimental uncertainty of previously reported experimental values, whereas this is the first report of D0 (Th+-C). Both BDEs are observed to be larger than those of their transition metal congeners, TiL+, ZrL+, and HfL+ (L = O and C), believed to be a result of lanthanide contraction. Additionally, the reactions were explored by quantum chemical calculations, including a full Feller-Peterson-Dixon composite approach with correlation contributions up to coupled-cluster singles and doubles with iterative triples and quadruples (CCSDTQ) for ThC, ThC+, ThO, and ThO+, as well as more approximate CCSD with perturbative (triples) [CCSD(T)] calculations where a semi-empirical model was used to estimate spin-orbit energy contributions. Finally, the ThO+ BDE is compared to other actinide (An) oxide cation BDEs and a simple model utilizing An+ promotion energies to the reactive state is used to estimate AnO+ and AnC+ BDEs. For AnO+, this model yields predictions that are typically within experimental uncertainty and performs better than density functional theory calculations presented previously.

Preparation of ThO2 sols having colloid-size distributions suitable for gelation into microspheres

International Nuclear Information System (INIS)

Yamagishi, Shigeru; Takahashi, Yoshihisa; Shiba, Koreyuki

1984-01-01

Production conditions of ThO 2 sols suitable for gelling into crackfree microspheres in an external gelation process were studied. The sols were prepared under pH control and colloid size distributions of the resulting sols were determined. The gelation was carried out by using hexone as a drop formation medium and ammonia as a gelling agent. The crackfree gelation was achieved by the use of ThO 2 sols produced under favorable pH, which were large in colloid size and high in colloid fraction. ''Preneutralization'' preceding the pH control is also important for the good sols. Analyzing the colloid fraction, colloid size and crystallite size of sol, it was found that, under the favorable pH, colloid nuclei generating at early stages grow in the form of single-crystals with their number kept constant and, after cooling, they exist as polycrystalline colloids. The mechanism of cracking is also discussed. (author)

Drill bit seismic, vertical seismic profiling, and seismic depth imaging to aid drilling decisions in the Tho Tinh structure, Nam Con Son basin, Vietnam

Energy Technology Data Exchange (ETDEWEB)

Borland, W; Hayashida, N; Kusaka, H; Leaney, W; Nakanishi, S

1996-10-01

This paper reviews the problem of overpressure, a common reason for acquiring look-ahead VSPs, and the seismic trace inversion problem, a fundamental issue in look-ahead prediction. The essential components of intermediate VSPs were examined from acquisition through processing to inversion, and recently acquired real data were provided, which were indicative of the advances being made toward developing an exclusive high resolution VSP service. A simple interpretation method and an end product of predicted mud weight versus depth were also presented, which were obtained from the inverted acoustic impedance and empirical relations. Of paramount importance in predicting the depth to a target was the velocity function used below the intermediate TD. The use of empirical or assumed density functions was an obvious weak link in the procedure. The advent of real-time time-depth measurements from drill bit seismic allowed a continuously updated predicted target depth below the present bit depth. 8 refs., 7 figs.

Magnetic and electric dipole moments of the H 3Δ1 state in ThO

International Nuclear Information System (INIS)

Vutha, A. C.; Kirilov, E.; DeMille, D.; Spaun, B.; Gurevich, Y. V.; Hutzler, N. R.; Doyle, J. M.; Gabrielse, G.

2011-01-01

The metastable H 3 Δ 1 state in the thorium monoxide (ThO) molecule is highly sensitive to the presence of a CP-violating permanent electric dipole moment of the electron (eEDM) [E. R. Meyer and J. L. Bohn, Phys. Rev. A 78, 010502 (2008)]. The magnetic dipole moment μ H and the molecule-fixed electric dipole moment D H of this state are measured in preparation for a search for the eEDM. The small magnetic moment μ H =8.5(5)x10 -3 μ B displays the predicted cancellation of spin and orbital contributions in a 3 Δ 1 paramagnetic molecular state, providing a significant advantage for the suppression of magnetic field noise and related systematic effects in the eEDM search. In addition, the induced electric dipole moment is shown to be fully saturated in very modest electric fields (<10 V/cm). This feature is favorable for the suppression of many other potential systematic errors in the ThO eEDM search experiment.

Water Quality Dynamics of Urban Water Bodies during Flooding in Can Tho City, Vietnam

Directory of Open Access Journals (Sweden)

Hong Quan Nguyen

2017-04-01

Full Text Available Water pollution associated with flooding is one of the major problems in cities in the global South. However, studies of water quality dynamics during flood events are not often reported in literature, probably due to difficult conditions for sampling during flood events. Water quality parameters in open water (canals, rivers, and lakes, flood water on roads and water in sewers have been monitored during the extreme fluvial flood event on 7 October 2013 in the city of Can Tho, Vietnam. This is the pioneering study of urban flood water pollution in real time in Vietnam. The results showed that water quality is very dynamic during flooding, especially at the beginning of the event. In addition, it was observed that the pathogen and contaminant levels in the flood water are almost as high as in sewers. The findings show that population exposed to flood water runs a health risk that is nearly equal to that of being in contact with sewer water. Therefore, the people of Can Tho not only face physical risk due to flooding, but are also exposed to health risks.

Heat capacity measurements on ThO2 by temperature modulated differential scanning calorimetry (TMDSC)

International Nuclear Information System (INIS)

Venkatakrishnan, R.; Nagarajan, K.; Vasudeva Rao, P.R.

2001-01-01

Heat capacity measurements were carried out on ThO 2 in the temperature range 330-820 K by using temperature modulated DSC. An underlying heating rate of 5 K. min -1 , a temperature modulation with an amplitude of 0.398K and a period of 150s were used for these measurements. The heat capacity values are within ± 2-4% of the literature data. (author)

Postirradiation examination report of TRISO and BISO coated ThO2 particles irradiated in capsules HT-31 and HT-33

International Nuclear Information System (INIS)

Sedlak, B.J.

1980-01-01

Capsules HT-31 and HT-33 were uninstrumented capsule experiments irradiated in the target position of the High-Flux Isotope Reactor at Oak Ridge National Laboratory. The experiments were used to evaluate the irradiation performance of (1) fuel fabricated in a 240-mm-diameter coater for production scale-up, (2) TRISO ThO 2 and BISO ThO 2 particles, and (3) fuel with certain OPyC variables. A total of 16 BISO particle samples and 32 TRISO particle samples were irradiated to fast neutron fluences ranging from 4.0 to 11.7 x 10 25 n/m 2 (E > 29 fJ)/sub HTGR/ and heavy metal burnups between 3.5% and 13.2% FIMA at temperatures from 1150 0 to 1530 0 C

Theoretical study of thorium monoxide for the electron electric dipole moment search: Electronic properties of H{sup 3}Δ{sub 1} in ThO

Energy Technology Data Exchange (ETDEWEB)

Skripnikov, L. V., E-mail: leonidos239@gmail.com; Titov, A. V. [B.P. Konstantinov Petersburg Nuclear Physics Institute, Gatchina, Leningrad district 188300 (Russian Federation); Department of Physics, Saint Petersburg State University, Saint Petersburg, Petrodvoretz 198504 (Russian Federation)

2015-01-14

Recently, improved limits on the electron electric dipole moment, and dimensionless constant, k{sub T,P}, characterizing the strength of the T,P-odd pseudoscalar–scalar electron–nucleus neutral current interaction in the H{sup 3}Δ{sub 1} state of ThO molecule were obtained by the ACME collaboration [J. Baron et al., Science 343, 269 (2014)]. The interpretation of the experiment in terms of these fundamental quantities is based on the results of theoretical study of appropriate ThO characteristics, the effective electric field acting on electron, E{sub eff}, and a parameter of the T,P-odd pseudoscalar–scalar interaction, W{sub T,P}, given in Skripnikov et al. [J. Chem. Phys. 139, 221103 (2013)] by St. Petersburg group. To reduce the uncertainties of the given limits, we report improved calculations of the molecular state–specific quantities E{sub eff}, 81.5 GV/cm, and W{sub T,P}, 112 kHz, with the uncertainty within 7% of the magnitudes. Thus, the values recommended to use for the upper limits of the quantities are 75.8 GV/cm and 104 kHz, correspondingly. The hyperfine structure constant, molecule-frame dipole moment of the H{sup 3}Δ{sub 1} state, and the H{sup 3}Δ{sub 1} → X{sup 1}Σ{sup +} transition energy which, in general, can serve as a measure of reliability of the obtained E{sub eff} and W{sub T,P} values are also calculated. In addition, we report the first calculation of g-factor for the H{sup 3}Δ{sub 1} state of ThO. The results are compared to the earlier experimental and theoretical studies, and a detailed analysis of uncertainties of the calculations is given.

Powder preparation, compaction and sintering of ThO2 and (U,Th)O2 - a review

International Nuclear Information System (INIS)

Balakrishna, Palanki; Hemantha Rao, G.V.S.

2012-01-01

Sustainable development is the development that meets the needs of the present generation without compromising the needs of future generations. In spite of the disaster at Fukushima, nuclear power remains a clean viable alternative to fossil fuels that has wreaked havoc on the environment by way of global warming, climate change, melting ice caps and rising sea levels. Thorium fuels complement uranium fuels and ensure long term sustainability of nuclear power. Thorium is 3 to 4 times more abundant than uranium and widely distributed in nature as an easily exploitable resource. In recent times, the need for proliferation-resistance, longer fuel cycles, higher burn up, improved waste form characteristics, reduction of plutonium inventories and in situ use of bred-in fissile material has led to renewed interest in thorium-based fuels and fuel cycles in several countries. ThO 2 containing around 4 % 233 UO 2 along with ThO 2 - 3 to 4 % PuO 2 is the proposed fuel for the Indian Advanced Heavy Water Reactor

Microbial Risk Assessment of Tidal-Induced Urban Flooding in Can Tho City (Mekong Delta, Vietnam).

Science.gov (United States)

Nguyen, Hong Quan; Huynh, Thi Thao Nguyen; Pathirana, Assela; Van der Steen, Peter

2017-11-30

Public health risks from urban flooding are a global concern. Contaminated floodwater may expose residents living in cities as they are in direct contact with the water. However, the recent literature does not provide much information about this issue, especially for developing countries. In this paper, the health risk due to a flood event occurred in Can Tho City (Mekong Delta, Vietnam) on 7 October 2013 was investigated. The Quantitative Microbial Risk Assessment method was used in this study. The data showed that the pathogen concentrations were highly variable during the flood event and exceeded water standards for surface water. Per 10,000 people in contact with the floodwater, we found Salmonella caused the highest number of infections to adults and children (137 and 374, respectively), while E. coli caused 4 and 12 cases, per single event, respectively. The results show that further investigations on health risk related to flood issues in Can Tho City are required, especially because of climate change and urbanization. In addition, activities to raise awareness- about floods, e.g., "living with floods", in the Mekong Delta should also consider health risk issues.

Microbial Risk Assessment of Tidal−Induced Urban Flooding in Can Tho City (Mekong Delta, Vietnam

Directory of Open Access Journals (Sweden)

Hong Quan Nguyen

2017-11-01

Full Text Available Public health risks from urban flooding are a global concern. Contaminated floodwater may expose residents living in cities as they are in direct contact with the water. However, the recent literature does not provide much information about this issue, especially for developing countries. In this paper, the health risk due to a flood event occurred in Can Tho City (Mekong Delta, Vietnam on 7 October 2013 was investigated. The Quantitative Microbial Risk Assessment method was used in this study. The data showed that the pathogen concentrations were highly variable during the flood event and exceeded water standards for surface water. Per 10,000 people in contact with the floodwater, we found Salmonella caused the highest number of infections to adults and children (137 and 374, respectively, while E. coli caused 4 and 12 cases, per single event, respectively. The results show that further investigations on health risk related to flood issues in Can Tho City are required, especially because of climate change and urbanization. In addition, activities to raise awareness- about floods, e.g., “living with floods”, in the Mekong Delta should also consider health risk issues.

Microbial Risk Assessment of Tidal−Induced Urban Flooding in Can Tho City (Mekong Delta, Vietnam)

Science.gov (United States)

Huynh, Thi Thao Nguyen; Van der Steen, Peter

2017-01-01

Public health risks from urban flooding are a global concern. Contaminated floodwater may expose residents living in cities as they are in direct contact with the water. However, the recent literature does not provide much information about this issue, especially for developing countries. In this paper, the health risk due to a flood event occurred in Can Tho City (Mekong Delta, Vietnam) on 7 October 2013 was investigated. The Quantitative Microbial Risk Assessment method was used in this study. The data showed that the pathogen concentrations were highly variable during the flood event and exceeded water standards for surface water. Per 10,000 people in contact with the floodwater, we found Salmonella caused the highest number of infections to adults and children (137 and 374, respectively), while E. coli caused 4 and 12 cases, per single event, respectively. The results show that further investigations on health risk related to flood issues in Can Tho City are required, especially because of climate change and urbanization. In addition, activities to raise awareness- about floods, e.g., “living with floods”, in the Mekong Delta should also consider health risk issues. PMID:29189715

Biodegradation of organ chlorine pesticides in contaminated soil collected from Yen Tap, Cam Khe, Phu Tho

International Nuclear Information System (INIS)

Nguyen Thuy Binh; Nguyen Van Toan; Pham Thi Thai; Dinh Thi Thu Hang

2007-01-01

Biodegradation of POPs contaminant in soil collected from Phu Tho province and Nghe An province had carried out. The process comprises treating soil, which contains anaerobic and aerobic microbes capable of transforming lindane and DDT into harmless material and being under anaerobic and aerobic steps. Significant biodegradation of POPs contaminants occurred in there tests. But some of toxic organic compounds remained. (author)

Microspheres of UO2, ThO2 and PuO2 for the high temperature reactor

International Nuclear Information System (INIS)

Brandau, E.

2002-01-01

The production of high temperature reactor fuel, so called pebble fuel, was done in the eighties by a special vibrational dropping process to obtain as sintered UO 2 - or ThO 2 -microspheres, so called 'Kernels', with a diameter size of about 300 μm. These microspheres have been coated and embedded in carbon balls to get the pebble fuel. Since the early nineties BRACE is developing the processings of microspheres starting with sols and suspensions to produce Al 2 O 3 , ZrO 2 , HfO 2 and Actinide oxide microspheres. Two main developments have been made: 1) the preparation of the feed solution (sol, suspension) and the solidification processing, and 2) the equipment, design, and electronic control have been completely changed. A newly developed suspension process for actinide oxides and for metal oxides e.g. Al 2 O 3 , TiO 2 , SiO 2 , ZrO 2 , HfO 2 , CeO 2 , ThO 2 , UO 2 , PuO 2 leads to cheaper production of as sintered microspheres. The processing and the installations will be described and the experience of production will be shown. (author)

Thoria-fuel irradiation. Program to irradiate 80% ThO2/20% UO2 ceramic pellets at the Savannah River Plant

International Nuclear Information System (INIS)

Pickett, J.B.

1982-02-01

This report describes the fabrication of proliferation-resistant thorium oxide/uranium oxide ceramic fuel pellets and preparations at the Savannah River Laboratory (SRL) to irradiate those materials. The materials were fabricated in order to study head end process steps (decladding, tritium removal, and dissolution) which would be required for an irradiated proliferation-resistant thorium based fuel. The thorium based materials were also to be studied to determine their ability to withstand average commercial light water reactor (LWR) irradiation conditions. This program was a portion of the Thorium Fuel Cycle Technology (TFCT) Program, and was coordinated by the Oak Ridge National Laboratory (ORNL) under the Consolidated Fuel Reprocessing Program (CFRP). The fuel materials were to be irradiated in a Savannah River Plant (SRP) reactor at conditions simulating the heat ratings and burnup of a commercial LWR. The program was terminated due to a de-emphasis of the TFCT Program, following completion of the fabrication of the fuel and the modified assemblies which were to be used in the SRP reactor. The reactor grade ceramic pellets were fabricated for SRL by Battelle, Pacific Northwest Laboratories. Five fuel types were prepared: 100% UO 2 pellets (control); 80% ThO 2 /20% UO 2 pellets; approximately 80% ThO 2 /20% UO 2 + 0.25 CaO (dissolution aid) pellets; 100% UO 2 hybrid pellets (prepared from sol-gel microspheres); and 100% ThO 2 pellets (control). All of the fuel materials were transferred to SRL from PNL and were stored pending a subsequent reactivation of the TFCT Programs

Investigations by gamma spectrometry and histoaudiography of the biokinetics of colloidal 232ThO2 ('Thorotrast')

International Nuclear Information System (INIS)

Foell, U.

1978-01-01

Experiments were carried out in mice in order to determine activity ratios and distribution kinetics of ThO 2 and its decay products. The data will be used as a basic for dose calculations. In supplementary investigations, the microdistribution, localisation, and quantitative enrichment of thorotrast were determined in order to provide a basis for microdosimetric evaluation of late thorotrast lesions. The radioactive colloid was injected intravenously into the tail vein of the animals (25 to 250 μl). Whole-body activity was measured at regular intervals. The animals were killed at different times after incorporation, and their livers, spleens, and skeleton without bone marrow were investigated by gammy spectrometry and histoautoradiography. With the findings obtained for the macroscopic distribution of colloid 232 ThO 2 and its decay products on the cellular level as a function of the duration of thorotrast storage, the mean radiation exposure of RHS organs can be determined and at least the order of magnitude of the local dose can be estimated. It will require long-term animal experiments to determine the biological effects of thorotrast incorporation and correlate them with the results of these dose calculations on the basis of the studies on thorotrast biokinetics. (orig./MG) [de

Radiochemical separation and ICP-AES determination of some common metallic elements in ThO2 matrix

International Nuclear Information System (INIS)

Adya, V.C.; Hon, N.S.; Bangia, T.R.; Sastry, M.D.; Iyer, R.H.

1997-01-01

Radioactive tracer and also ICP-AES studies have been carried out to determine Al, Cd, Ca, Cr, Co, Cu, Mn, Mo and Pd in ThO 2 matrix after chemical separation. Di-2-ethyl-hexyl phosphoric acid/xylene/HNO 3 extraction system was used for quantitative separation of thorium. The recovery of elements as determined by tracers and ICP-AES was found to be quantitative within experimental error. (author). 3 refs., 1 tab

Analysis of neutron parameters in light water moderated lattices of ThO2 and UO2 fuel rods

International Nuclear Information System (INIS)

Onusic Junior, J.; Oosterkamp, W.J.

1977-01-01

A large number of light water moderated lattices of UO 2 and ThO 2 fuel rods were analyzed with the code HAMMER. The purpose of the study was to compare experimental results with computer calculated values. The model employed is described and some modification were introduced in the resonance parameters of Th-232 to increase the agreement with the experimental value [pt

Phase relations in crystalline ceramic nuclear waste forms the system UO/sub 2 + x/-CeO2-ZrO2-ThO2 at 12000C in air

International Nuclear Information System (INIS)

Pepin, J.G.; McCarthy, G.J.

1981-01-01

Steady-state phase relations in the system UO/sub 2 + x/-CeO 2 -ZrO 2 -ThO 2 were determined for application to phase relations in the high-level crystalline ceramic nuclear waste form Supercalcine-Ceramics. Samples were treated at 1200 0 C at an oxygen partial pressure of 0.21 atm and a total pressure of 1 atm. Phase assemblages were found to be composed of cubic solid solutions of the flourite structure type, solid solutions based on ZrO 2 , and orthorhombic solid solutions based on U 3 O 8

X-ray spectral study of the Th6p,5f electron states in ThO2 and ThF4

International Nuclear Information System (INIS)

Teterin, Y.A.; Nikitin, A.S.; Teterin, A.Y.; Ivanov, K.E.; Utkin, I.O.; Nerehov, V.A.; Ryzhkov, M.V.; Vukchevich, I.J.

2002-01-01

The study of the Th6p,5f electron states in Th, ThO 2 and ThF was carried out on the basis of the X-ray photoelectron fine spectral structure parameters in the binding energy range of 0-∼ 1000 eV, X-ray O 4,5 (Th) emission spectra of the shallow (0-∼50 eV) electrons and results of theoretical calculations. As a result, despite the absence of the Th5f electrons in thorium atoms, the Th5f atomic orbitals were established to participate in the formation of molecular orbitals in thorium dioxide and tetrafluoride. In the MO LCAO approximation this allowed to suggest the possible existence of filled Th5f electronic states in thorium compounds. On the basis of the X-ray O 4,5 (Th) emission spectral structure parameters the effective formation of the inner valence molecular orbitals in the studied compounds was confirmed. (authors)

Fracture properties of ThO2-UO2 pellets by Hertzian indentation technique

International Nuclear Information System (INIS)

Kutty, T.R.G.; Rath, B.N.; Balakrishnan, K.S.

2005-01-01

Fracture toughness (K Ic ) and fracture surface energy (γ s ) of ThO 2 -UO 2 pellets with varying UO 2 contents were measured using Hertzian indentation technique. The knowledge of fracture toughness (K Ic ) and fracture surface energy values are important for fuel designers since these values are used in fuel modeling. Cracks in nuclear fuel act as a path for fission gas release and enhances fuel cladding mechanical interaction. Microstructural features like grain size and presence of second phase play a significant role in controlling the fracture behavior. Since the fracture properties of nuclear materials are of primary design consideration, it is important that these properties should be evaluated with good precision. There have been several attempts to use Hertzian indentation for evaluating the fracture toughness of brittle materials. The main principle of this method depends on the interaction of the elastic stress field with a pre-existing surface flaw of the sample. One significant advantage of Hertzian indentation over that of Vickers is that the substrate's deformation is entirely elastic until fracture occurs. This avoids the complications arising from the ill-defined residual stress that is normally associated with indentations brought about by pointed indenters like that of Vickers. The material properties that may be determined by this test include (a) fracture toughness and fracture surface energy of the near surface material, (b) the densities and sizes of surface cracks, and (c) residual stresses in the near surface material. This paper deals with experimental procedure for the evaluation of fracture properties of ThO 2 -UO 2 of varying U content and results thus obtained are also presented. The K Ic values thus obtained are explained in terms of their microstructures and the U content. (author)

Sample preparation and analysis of large 238PuO2 and ThO2 spheres

International Nuclear Information System (INIS)

Wise, R.L.; Selle, J.E.

1975-01-01

A program was initiated to determine the density gradient across a large spherical 238 PuO 2 sample produced by vacuum hot pressing. Due to the high thermal output of the ceramic a thin section was necessary to prevent overheating of the plastic mount. Techniques were developed for cross sectioning, mounting, grinding, and polishing of the sample. The polished samples were then analyzed on a quantitative image analyzer to determine the density as a function of location across the sphere. The techniques for indexing, analyzing, and reducing the data are described. Typical results obtained on a ThO 2 simulant sphere are given

HYPER RECOMBINATION1 of the THO/TREX complex plays a role in controlling transcription of the REVERSION-TO-ETHYLENE SENSITIVITY1 gene in Arabidopsis.

Directory of Open Access Journals (Sweden)

Congyao Xu

2015-02-01

Full Text Available Arabidopsis REVERSION-TO-ETHYLENE SENSITIVITY1 (RTE1 represses ethylene hormone responses by promoting ethylene receptor ETHYLENE RESPONSE1 (ETR1 signaling, which negatively regulates ethylene responses. To investigate the regulation of RTE1, we performed a genetic screening for mutations that suppress ethylene insensitivity conferred by RTE1 overexpression in Arabidopsis. We isolated HYPER RECOMBINATION1 (HPR1, which is required for RTE1 overexpressor (RTE1ox ethylene insensitivity at the seedling but not adult stage. HPR1 is a component of the THO complex, which, with other proteins, forms the TRanscription EXport (TREX complex. In yeast, Drosophila, and humans, the THO/TREX complex is involved in transcription elongation and nucleocytoplasmic RNA export, but its role in plants is to be fully determined. We investigated how HPR1 is involved in RTE1ox ethylene insensitivity in Arabidopsis. The hpr1-5 mutation may affect nucleocytoplasmic mRNA export, as revealed by in vivo hybridization of fluorescein-labeled oligo(dT45 with unidentified mRNA in the nucleus. The hpr1-5 mutation reduced the total and nuclear RTE1 transcript levels to a similar extent, and RTE1 transcript reduction rate was not affected by hpr1-5 with cordycepin treatment, which prematurely terminates transcription. The defect in the THO-interacting TEX1 protein of TREX but not the mRNA export factor SAC3B also reduced the total and nuclear RTE1 levels. SERINE-ARGININE-RICH (SR proteins are involved mRNA splicing, and we found that SR protein SR33 co-localized with HPR1 in nuclear speckles, which agreed with the association of human TREX with the splicing machinery. We reveal a role for HPR1 in RTE1 expression during transcription elongation and less likely during export. Gene expression involved in ethylene signaling suppression was not reduced by the hpr1-5 mutation, which indicates selectivity of HPR1 for RTE1 expression affecting the consequent ethylene response. Thus

First-principles study of helium clustering at initial stage in ThO2

International Nuclear Information System (INIS)

Shao Kuan; Han Han; Zhang Wei; Wang Chang-Ying; Guo Yong-Liang; Ren Cui-Lan; Huai Ping

2017-01-01

The clustering behavior of helium atoms in thorium dioxide has been investigated by first-principles calculations. The results show that He atoms tend to form a cluster around an octahedral interstitial site (OIS). As the concentration of He atoms in ThO 2 increases, the strain induced by the He atoms increases and the octahedral interstitial site is not large enough to accommodate a large cluster, such as a He hexamer. We considered three different Schottky defect (SD) configurations (SD 1 , SD 2 , and SD 3 . When He atoms are located in the SD sites, the strain induced by the He atoms is released and the incorporation and binding energies decrease. The He trimer is the most stable cluster in SD 1 . Large He clusters, such as a He hexamer, are also stable in the SDs. (paper)

investigation of production conditions of ThO2-(%0-40)UO3 microspheres suitable for pellet production

International Nuclear Information System (INIS)

Tel, H.; Eral, M.; Altas, Y.

1997-01-01

The aim of the present study is to prepare homogeneous,sinterable and high density ThO 2 and thorium based (Th,U)O 2 pellets by using sol-gel transition. For the purpose to obtain of stable ThO 2 -UO 3 mixed sols suitable for gelling into crackfree microspheres, first the nitrate solutions of thorium and uranium at the different mol ratios of uranium (0, 5,10, 20, 30, 35 and 40 percent) were prepared. The sources sols used for the processes have been prepared by an ammonia addition method where starting nitrate solutions of thorium and uranium are heated and partially neutralized by aqueous ammonia under pH control at the different pH set and neutralization mode for each uranium mol ratio. Crackfree microspheres suitable for gelation were obtained by using hexone-10 % CCl 4 mixture as drop formation medium and ammonia as a gelling agent.Following the washing and aging, the formed gel microspheres were treated with IPA (isopropyl alcohol), dried at 85 o C and then heat-treated in air atmosphere at 300 o C.The dimensions, sphericity, bulk and apparent densities and specific surface area of microspheres were determined. Before the compaction the microspheres were exposed to air in a medium controlled at 30 o C and 85 % relative humidity and humidified to a moisture ratio > 18 % and then pelletized. The geometric densities of pellets were measured and then the pellets were sintered in 75 % Ar - 25 % H 2 atmosphere at 1090+-10 o C during 150 minutes

Preparation of nuclear oxide powders via thermal decomposition. Ex: ThO2

International Nuclear Information System (INIS)

Bayoglu, A. S.; Yayli, A.; Tarhan, M.; Bayram, Y.; Aybers, M. T.; Kopuz, B.

1986-01-01

In this paper, the influence of thorium oxalate precipitation variable (temperature, digertion time, agitation and addition rate of oxalic acid, etc.) and calcination parameters (temperature and time) upon the properties of derived powder characteristics (specific surface area, cryctallite size, morphology, etc.) was investigated. The results obtained indicate that the temperature has an important effect upon the particle morphology among the thorium oxalate precipitation variables. The low precipitation temperature gives the smaller particles. The ThO 2 powder has the same shape and the size of the parent oxalate. The precipitations variables don't exhibit an appreciable change on the specific surface area and crystallite size. The calcination temperature and time has an important influence on the specific surface area which is an exponentielly decreasing function of the temperature due to the introparticle sintering. The calcination temperature has not a noticeable effect between 700 C o -900 C o on the particle sizes and morphology. (author)

Experimental investigations into the spectral reflectivity and emissivity of liquid UO2, UC, ThO2, and Nd2O3

International Nuclear Information System (INIS)

Karow, H.U.; Bober, M.

1979-01-01

Fast reactor safety research requires knowledge of emissivity data of nuclear fuel materials up to temperatures of the liquid state. A special integrating sphere laser reflectometer has been used to measure the normal reflectivity and emissivity of UO 2 , UC, ThO 2 , and in addition of Nd 2 O 3 in the solid state (premolten, refrozen material) and in the liquid state up to temperatures of 4000 to 4800 K. The measuring wavelengths have been 0.63 μm and 10.6 μm. The emissivity curves of the oxidic specimens measured at 0.63 μm show the same characteristic course: little temperature dependence below the melting point, distinct increase in the liquid state. In the case of UO 2 the emissivity at the melting point (3120 K) is 0.84, at 4100 K it is 0.92. At 10.6 μm, a decrease has been measured for the liquid state of UO 2 and ThO 2 . UC shows in the solid and in the liquid state only a small temperature dependence with a marked drop, however, at the melting point (2780 K) from 0.54 to 0.45. The measuring results are presented by diagrams and by fit equations related to the true and the black temperature, respectively. (orig./HP) [de

Preliminary design needs for pilot plant of Monazite processing into Thorium Oxide (ThO_2)

International Nuclear Information System (INIS)

Hafni Lissa Nuri; Prayitno; Abdul Jami; M-Pancoko

2014-01-01

Data and information collection aimed in order to meet the needs of the initial design for pilot plant of monazite processing into thorium oxide (ThO_2). The content of thorium in monazite is high in Indonesia between 2.9 to 4.1% and relatively abundant in Bangka Belitung Islands. Thorium can be used as fuel because of its potential is more abundant instead of uranium. Plant of thorium oxide commercially from monazite established starting from pilot uranium. Plant of thorium oxide commercially from monazite established starting from pilot plant in order to test laboratory data. Pilot plant design started from initial design, basic design, detailed design, procurement and construction. Preliminary design needs includes data feed and products, a block diagram of the process, a description of the process, the determination of process conditions and type of major appliance has been conducted. (author)

Field evaluation of spatial repellency of metofluthrin-impregnated latticework plastic strips against Aedes aegypti (L.) and analysis of environmental factors affecting its efficacy in My Tho City, Tien Giang, Vietnam.

Science.gov (United States)

Kawada, Hitoshi; Iwasaki, Tomonori; LE Loan, Luu; Tien, Tran Khanh; Mai, Nguyen Thi Nhu; Shono, Yoshinori; Katayama, Yasuyuki; Takagi, Masahiro

2006-12-01

Spatial repellency of metofluthrin-impregnated polyethylene latticework plastic strips against Aedes aegypti mosquitoes was evaluated. Analysis of environmental factors affecting the efficacy of these strips, such as room temperature, humidity, and house structure, was performed in a residential area in My Tho City, Tien Giang Province, Vietnam. Treatment with the strips at the rate of 1 strip per 2.6-5.52 m(2) (approximately 600 mg per 2.6-5.52 m(2)) reduced the collection of Ae. aegypti resting inside the houses for at least eight weeks. Multiple regression analysis indicated that both increase in the average room temperature and decrease in the area of openings in the rooms that were treated with the strips positively affected the spatial repellency of metofluthrin.

Synthesis, characterization, kinetic and thermodynamic studies of the dissolution of ThO2 and of solid solutions Th1-xMxO2 (M = U, Pu)

International Nuclear Information System (INIS)

Heisbourg, G.

2003-12-01

The aim of this work was to understand the mechanisms of dissolution of ThO 2 and of thorium mixed oxides such as Th 1-x U x O 2 and Th 1-x Pu x O 2 in aqueous, oxygenated or inert media. Several solids have been synthesized by precipitation in oxalic medium: Th 1-x U x O 2 (x= 0.11; 0.24; 0.37; 0.53; 0.67; 0.81 and 0.91) and Th 1-x Pu x O 2 (x= 0.13; 0.32 and 0.66). They have been characterized by XRD, SEM, TEM, XPS, XAS, PIXE and EPMA. The sintering conditions of these materials have been studied and optimized in order to obtain sintered samples with a measured density very near the theoretical densities. A kinetic study of the dissolution of ThO 2 and of solid solutions Th 1-x U x O 2 has been carried out in several aqueous media (HNO 3 , HCl, H 2 SO 4 ) in terms of several parameters: protons concentration, temperature, pH, ionic strength, nature of the electrolyte solution and uranium molar ratio for the solid solutions Th 1-x U x O 2 in order to determine the kinetic laws of dissolution of the solid solutions having different compositions comparatively to ThO 2 . The leaching tests carried out in natural waters of compositions near those of the deep geologic sites considered for the storage of nuclear wastes have shown that the dissolution of the solids was bound to the complexing effect of the constitutional ions of the water considered. The leaching tests carried out on sintered samples of the same composition have led to the same normalized dissolution velocities. The thermodynamic aspect of the dissolution of the solid solutions Th 1-x U x O 2 in nitric medium has been studied at last. (O.M.)

Methods for assessing homogeneity in ThO2--UO2 fuels (LWBR Development Program)

International Nuclear Information System (INIS)

Berman, R.M.

1978-06-01

ThO 2 -UO 2 solid solutions fabricated as LWBR fuel pellets are examined for uniform uranium distribution by means of autoradiography. Kodak NTA plates are used. Images of inhomogeneities are 29 +- 10 microns larger in diameter than the high-urania segregations that caused them, due to the range of alpha particles in the emulsion, and an appropriate correction must be made. Photographic density is approximately linear with urania content in the region between underexposure and overexposure, but the slope of the calibration curve varies with aging and growth of alpha activity from the parasitic 232 U and its decomposition products. A calibration must therefore be performed using two known points--the average photographic density (corresponding to the average composition) and an extrapolated background (corresponding to zero urania). As part of production pellet inspection, plates are evaluated by inspectors, who count segregations by size classes. This is supplemented by microdensitometer scans of the autoradiograph and by electron probe studies of the original sample if apparent homogeneity is marginal

Flood precautionary behaviour of private households in Can Tho city in the Mekong Delta

Science.gov (United States)

Kreibich, Heidi; Gani Adnan, Sarfaraz; Thi Chinh, Do; Bubeck, Philip

2015-04-01

Flood risk is high and it is projected to increase in many places due to the effects of climate change and the on-going intensification of human activities in risk-prone areas. These projections and the considerable uncertainties associated with these developments increasingly require integrated approaches in flood risk management. In addition to flood protection, private precautionary measures aim at reducing the potential negative consequences of floods. Thus, insights into flood precautionary behaviour are important. This study is grounded on the Protection Motivation Theory (PMT), which refers to the cognitive process that people undergo when evaluating their own ability to avoid a certain risk. Results of a survey among 858 flood-prone households in Can Tho city in the Mekong Delta, Vietnam are presented. It is shown that flood-coping appraisal is an important variable in terms of precautionary behaviour. Thus, risk communication should focus more on the potential of precautionary measures to effectively reduce flood damage, as well as on information about how to implement such measures in practice.

ThO2-based pellet fuels - their properties, methods of fabrication, and irradiation performance: a critical assessment of the state of the technology and recommendations for further work

International Nuclear Information System (INIS)

Hart, P.E.; Griffin, C.W.; Hsieh, K.A.; Matthews, R.B.; White, G.D.

1979-09-01

This critical assessment of the ThO 2 -UO 2 pellet fuel technology was conducted in support of the Fuels Refabrication and Development Program (FRAD). Included in this critical review are the following areas: powder preparation; pellet fabrication; fuel chemical, physical, and mechanical properties; and fuel irradiation performance. The authors identify (1) areas where data are either deficient or lacking and (2) requirements for additional development and experimental work

Combined fluvial and pluvial urban flood hazard analysis: method development and application to Can Tho City, Mekong Delta, Vietnam

Science.gov (United States)

Apel, H.; Trepat, O. M.; Hung, N. N.; Chinh, D. T.; Merz, B.; Dung, N. V.

2015-08-01

Many urban areas experience both fluvial and pluvial floods, because locations next to rivers are preferred settlement areas, and the predominantly sealed urban surface prevents infiltration and facilitates surface inundation. The latter problem is enhanced in cities with insufficient or non-existent sewer systems. While there are a number of approaches to analyse either fluvial or pluvial flood hazard, studies of combined fluvial and pluvial flood hazard are hardly available. Thus this study aims at the analysis of fluvial and pluvial flood hazard individually, but also at developing a method for the analysis of combined pluvial and fluvial flood hazard. This combined fluvial-pluvial flood hazard analysis is performed taking Can Tho city, the largest city in the Vietnamese part of the Mekong Delta, as example. In this tropical environment the annual monsoon triggered floods of the Mekong River can coincide with heavy local convective precipitation events causing both fluvial and pluvial flooding at the same time. Fluvial flood hazard was estimated with a copula based bivariate extreme value statistic for the gauge Kratie at the upper boundary of the Mekong Delta and a large-scale hydrodynamic model of the Mekong Delta. This provided the boundaries for 2-dimensional hydrodynamic inundation simulation for Can Tho city. Pluvial hazard was estimated by a peak-over-threshold frequency estimation based on local rain gauge data, and a stochastic rain storm generator. Inundation was simulated by a 2-dimensional hydrodynamic model implemented on a Graphical Processor Unit (GPU) for time-efficient flood propagation modelling. All hazards - fluvial, pluvial and combined - were accompanied by an uncertainty estimation considering the natural variability of the flood events. This resulted in probabilistic flood hazard maps showing the maximum inundation depths for a selected set of probabilities of occurrence, with maps showing the expectation (median) and the uncertainty by

TRU transmutation using ThO2-UO2 and fully ceramic micro-encapsulated fuels in LWR fuel assemblies

International Nuclear Information System (INIS)

Bae, Gonghoon; Hong, Sergi

2012-01-01

The objective of this work is to design new LWR fuel assemblies which are able to efficiently destroy TRU (transuranics) nuclide without degradation of safety aspects by using ThO 2 -UO 2 fuel pins and FCM (Fully Ceramic Micro-encapsulated) fuel pins containing TRU fuel particles. Thorium was mixed to UO 2 in order to reduce the generation of plutonium nuclides and to save the uranium resources in the UO 2 pins. Additionally, the use of thorium contributes to the extension of the fuel cycle length. All calculations were performed by using DeCART (Deterministic Core Analysis based on Ray Tracing) code. The results show that the new concept of fuel assembly has the TRU destruction rates of ∼40% and ∼25% per 1200 EFPD (Effective Full Power Day) over the TRU FCM pins and the overall fuel assembly, respectively, without degradation of FTC and MTC

Investigation of oxygen disorder, thermal parameters, lattice vibrations and elastic constants of UO2 and ThO2 at temperatures up to 2 930 K

DEFF Research Database (Denmark)

Clausen, Kurt Nørgaard; Hayes, W; Hutchings, M.T.

1984-01-01

temperatures has been unanswered until now. A new high temperature furnace has been purchased by Harwell for work at temperatures in this region, and a series of experiments has been carried out involving diffraction, quasielastic diffuse and inelastic neutron scattering from single crystals of UO2 and ThO2....... These have been backed by experiments in the lower temperature range to 2 500 K at I.L.L. Details of the Harwell furnace, and methods used for temperature measurement and encapsulation of the crystal samples are given, together with some examples of the principal results. These results show unambiguously...

Application of the Water Needs Index: Can Tho City, Mekong Delta, Vietnam

Science.gov (United States)

Moglia, Magnus; Neumann, Luis E.; Alexander, Kim S.; Nguyen, Minh N.; Sharma, Ashok K.; Cook, Stephen; Trung, Nguyen H.; Tuan, Dinh D. A.

2012-10-01

SummaryProvision of urban water supplies to rapidly growing cities of South East Asia is difficult because of increasing demand for limited water supplies, periodic droughts, and depletion and contamination of surface and groundwater. In such adverse environments, effective policy and planning processes are required to secure adequate water supplies. Developing a Water Needs Index reveals key elements of the complex urban water supply by means of a participatory approach for rapid and interdisciplinary assessment. The index uses deliberative interactions with stakeholders to create opportunities for mutual understanding, confirmation of constructs and capacity building of all involved. In Can Tho City, located at the heart of the Mekong delta in Vietnam, a Water Needs Index has been developed with local stakeholders. The functional attributes of the Water Needs Index at this urban scale have been critically appraised. Systemic water issues, supply problems, health issues and inadequate, poorly functioning infrastructure requiring attention from local authorities have been identified. Entrenched social and economic inequities in access to water and sanitation, as well as polluting environmental management practices has caused widespread problems for urban populations. The framework provides a common language based on systems thinking, increased cross-sectoral communication, as well as increased recognition of problem issues; this ought to lead to improved urban water management. Importantly, the case study shows that the approach can help to overcome biases of local planners based on their limited experience (information black spots), to allow them to address problems experienced in all areas of the city.

Procedure for the fabrication of ceramic fuel pellets with an adjustable structure

International Nuclear Information System (INIS)

Henke, M.; Klemm, U.; Sobek, D.

1986-01-01

The invention concerns a procedure for the fabrication of ceramic fuel pellets of UO 2 , PuO 2 , ThO 2 and their mixtures with an adjustable structure. Before or during the milling the particle shaped fuel pellets have been added polyethylenglycol in a 20 - 60 % aqueous solution with an amount of 0.5 - 2.0 % in weight. This additive has an effect on a controlled pore formation and grain growth advancement

Combined fluvial and pluvial urban flood hazard analysis: concept development and application to Can Tho city, Mekong Delta, Vietnam

Science.gov (United States)

Apel, Heiko; Martínez Trepat, Oriol; Nghia Hung, Nguyen; Thi Chinh, Do; Merz, Bruno; Viet Dung, Nguyen

2016-04-01

Many urban areas experience both fluvial and pluvial floods, because locations next to rivers are preferred settlement areas and the predominantly sealed urban surface prevents infiltration and facilitates surface inundation. The latter problem is enhanced in cities with insufficient or non-existent sewer systems. While there are a number of approaches to analyse either a fluvial or pluvial flood hazard, studies of a combined fluvial and pluvial flood hazard are hardly available. Thus this study aims to analyse a fluvial and a pluvial flood hazard individually, but also to develop a method for the analysis of a combined pluvial and fluvial flood hazard. This combined fluvial-pluvial flood hazard analysis is performed taking Can Tho city, the largest city in the Vietnamese part of the Mekong Delta, as an example. In this tropical environment the annual monsoon triggered floods of the Mekong River, which can coincide with heavy local convective precipitation events, causing both fluvial and pluvial flooding at the same time. The fluvial flood hazard was estimated with a copula-based bivariate extreme value statistic for the gauge Kratie at the upper boundary of the Mekong Delta and a large-scale hydrodynamic model of the Mekong Delta. This provided the boundaries for 2-dimensional hydrodynamic inundation simulation for Can Tho city. The pluvial hazard was estimated by a peak-over-threshold frequency estimation based on local rain gauge data and a stochastic rainstorm generator. Inundation for all flood scenarios was simulated by a 2-dimensional hydrodynamic model implemented on a Graphics Processing Unit (GPU) for time-efficient flood propagation modelling. The combined fluvial-pluvial flood scenarios were derived by adding rainstorms to the fluvial flood events during the highest fluvial water levels. The probabilities of occurrence of the combined events were determined assuming independence of the two flood types and taking the seasonality and probability of

Coping capacities for improving adaptation pathways for flood protection in Can Tho, Vietnam

Science.gov (United States)

Pathirana, A.; Radhakrishnan, M.; Quan, N. H.; Gersonius, B.; Ashley, R.; Zevenbergen, C.

2016-12-01

Studying the evolution of coping and adaptation capacities is a prerequisite for preparing an effective flood management plan for the future, especially in the dynamic and fast changing cities of developing countries. The objectives, requirements, targets, design and performance of flood protection measures will have to be determined after taking into account, or in conjunction with, the coping capacities. A methodology is presented based on adaptation pathways to account for coping capacities and to assess the effect on flood protection measures. The adaptation pathways method determines the point of failure of a particular strategy based on the change in an external driver, a point in time or a socio economic situation where / at which the strategy can no longer meet its objective. Pathways arrived at based on this methodology reflect future reality by considering changing engineering standards along with future uncertainties, risk taking abilities and adaptation capacities. This pathways based methodology determines the Adaptation tipping points (ATP), `time of occurrence of ATP' of flood protection measures after accounting for coping capacities, evaluates the measures and then provides the means to determine the adaptation pathways. Application of this methodology for flood protection measures in Can Tho city in the Mekong delta reveals the effect of coping capacity on the usefulness of flood protection measures and the delay in occurrence of tipping points. Consideration of coping capacity in the system owing to elevated property floor levels lead to the postponement of tipping points and improved the adaptation pathways comprising flood protection measures such as dikes. This information is useful to decision makers for planning and phasing of investments in flood protection.

Comparison of stapled haemorrhoidopexy with traditional excisional surgery for haemorrhoidal disease (eTHoS): a pragmatic, multicentre, randomised controlled trial.

Science.gov (United States)

Watson, Angus J M; Hudson, Jemma; Wood, Jessica; Kilonzo, Mary; Brown, Steven R; McDonald, Alison; Norrie, John; Bruhn, Hanne; Cook, Jonathan A

2016-11-12

Two commonly performed surgical interventions are available for severe (grade II-IV) haemorrhoids; traditional excisional surgery and stapled haemorrhoidopexy. Uncertainty exists as to which is most effective. The eTHoS trial was designed to establish the clinical effectiveness and cost-effectiveness of stapled haemorrhoidopexy compared with traditional excisional surgery. The eTHoS trial was a large, open-label, multicentre, parallel-group, pragmatic randomised controlled trial done in adult participants (aged 18 years or older) referred to hospital for surgical treatment for grade II-IV haemorrhoids. Participants were randomly assigned (1:1) to receive either traditional excisional surgery or stapled haemorrhoidopexy. Randomisation was minimised according to baseline EuroQol 5 dimensions 3 level score (EQ-5D-3L), haemorrhoid grade, sex, and centre with an automated system to stapled haemorrhoidopexy or traditional excisional surgery. The primary outcome was area under the quality of life curve (AUC) measured with the EQ-5D-3L descriptive system over 24 months, assessed according to the randomised groups. The primary outcome measure was analysed using linear regression with adjustment for the minimisation variables. This trial is registered with the ISRCTN registry, number ISRCTN80061723. Between Jan 13, 2011, and Aug 1, 2014, 777 patients were randomised (389 to receive stapled haemorrhoidopexy and 388 to receive traditional excisional surgery). Stapled haemorrhoidopexy was less painful than traditional excisional surgery in the short term and surgical complication rates were similar between groups. The EQ-5D-3L AUC score was higher in the traditional excisional surgery group than the stapled haemorrhoidopexy group over 24 months; mean difference -0·073 (95% CI -0·140 to -0·006; p=0·0342). EQ-5D-3L was higher for stapled haemorrhoidopexy in the first 6 weeks after surgery, the traditional excisional surgery group had significantly better quality of life

Structural evolvement and the capability of resistance to γ-ray irradiation on zircon originating from nyainqentanglha granite

International Nuclear Information System (INIS)

Cui Chunlong; Zhang Dong; Kang Houjun; Wang Xiaoli; Zhou Yulin; Yi Facheng; Lu Xirui; Tang Jingyou

2010-01-01

In order to investigate the structural evolvement and the capability of resistance to γ-ray irradiation on zircon as mothball waste forms of radionuclide, the zircon crystals (11.01±0.24 M) were studied as investigative object, which were collected from nyainqentanglha granite. All the samples were irradiated using a 60 Co y-ray source with 576 kGy doses. Phases, structures and microstructures of the as-gained samples before and after y-ray irradiation were characterized by means of a multi-functional microscope, cathodoluminescence (CL), backscattered electron microprobe (BEM), X-ray diffraction (XRD), Raman spectroscopy (Raman), infrared spectroscopy (IR) and scanning electron microscopy (SEM), and so on. Moreover, the geological backgrounds and chemical compositions of zircons originating from natural rocks were analyzed as well. The results indicated that the as-gained crystals came from magmatic rock which undergone near 11 million years geological evolvement and still contain UO 2 and ThO 2 with the contents of 0.5729 wt%. The alteration of 10 -3 nm magnitude in the crystal cell parameters was measured (of the standard XRD card of zircon). The irradiation on the crystalline samples using γ-ray induced to the alteration of 10 -4 nm magnitude for their crystal cell parameters. The conclusion shows that zircon crystals with a certain amount of UO 2 and ThO 2 have better structural stability for the y-ray irradiation. (authors)

High-risk and multiple human papillomavirus infections among married women in Can Tho, Viet Nam.

Science.gov (United States)

Vu, Lan Thi Hoang

2012-07-01

The two currently licensed human papillomavirus (HPV) vaccines are highly efficacious in preventing cervical pre-cancers related to HPV 6, 11, 16 and 18. Before implementing a large-scale HPV vaccine campaign in Viet Nam, information about the prevalence of infection with the HPV vaccine types is required. This study was done in Can Tho, the province with the highest prevalence of cervical cancer in the south of Viet Nam, to explore the distribution of other high-risk types of HPV among married women in this province. The study employed a cross-sectional design with multistage sampling. A total of 1000 participants were randomly selected, interviewed and given gynaecological examinations. HPV infection status and HPV genotyping test were completed for all participants. A broad spectrum of HPV types was reported in this study. The prevalence of cases infected with HPV 16 and/or 18 was 7%; the prevalence of cases infected with other high-risk HPV types was 6%. The highest prevalence for single and multiple infections, as well as for high-risk infections, was reported for the youngest age group (less than 30 years). While it is relevant to implement an HPV vaccine campaign in Viet Nam due to the high prevalence of infection with HPV 16 and/or 18, it is important to note that one can be infected with multiple types of HPV. Vaccination does not protect against all types of high-risk HPV. Future vaccine campaigns should openly disclose this information to women receiving vaccines.

Chemical and structural evolution in the Th-SeO3(2-)/SeO4(2-) system: from simple selenites to cluster-based selenate compounds.

Science.gov (United States)

Xiao, Bin; Langer, Eike; Dellen, Jakob; Schlenz, Hartmut; Bosbach, Dirk; Suleimanov, Evgeny V; Alekseev, Evgeny V

2015-03-16

While extensive success has been gained in the structural chemistry of the U-Se system, the synthesis and characterization of Th-based Se structures are widely unexplored. Here, four new Th-Se compounds, α-Th(SeO3)2, β-Th(SeO3)2, Th(Se2O5)2, and Th3O2(OH)2(SeO4)3, have been obtained from mild hydrothermal or low-temperature (180-220 °C) flux conditions and were subsequently structurally and spectroscopically characterized. The crystal structures of α-Th(SeO3)2 and β-Th(SeO3)2 are based on ThO8 and SeO3 polyhedra, respectively, featuring a three-dimensional (3D) network with selenite anions filling in the Th channels along the a axis. Th(Se2O5)2 is a 3D framework composed of isolated ThO8 polyhedra interconnected by [Se2O5](2-) dimers. Th3O2(OH)2(SeO4)3 is also a 3D framework constructed by octahedral hexathorium clusters [Th6(μ3-O)4(μ3-OH)4](12+), which are interlinked by selenate groups SeO4(2-). The positions of the vibrational modes associated with both Se(IV)O3(2-) and Se(VI)O4(2-) units, respectively, were determined for four compounds, and the Raman spectra of α- and β-Th(SeO3)2 are compared and discussed in detail.

Two new species of the genus Pararrhynchium de Saussure (Hymenoptera: Vespidae: Eumeninae) from northern Vietnam.

Science.gov (United States)

Nguyen, Lien Thi Phuong

2015-06-22

Two new species of the genus Pararrhynchium are described and figured: P. striatum sp. nov. (northern Vietnam: Hoa Binh, Ha Tinh and Thai Nguyen) and P. concavum sp. nov. (northern Vietnam: Cao Bang). A key to all known species of the genus is provided.

Assessment of plastic waste generation and its potential recycling of household solid waste in Can Tho City, Vietnam.

Science.gov (United States)

Thanh, Nguyen Phuc; Matsui, Yasuhiro; Fujiwara, Takeshi

2011-04-01

Plastic solid waste has become a serious problem when considering the disposal alternatives following the sequential hierarchy of sound solid waste management. This study was undertaken to assess the quantity and composition of household solid waste, especially plastic waste to identify opportunities for waste recycling. A 1-month survey of 130 households was carried out in Can Tho City, the capital city of the Mekong Delta region in southern Vietnam. Household solid waste was collected from each household and classified into ten physical categories; especially plastic waste was sorted into 22 subcategories. The average household solid waste generation rate was 281.27 g/cap/day. The compostable and recyclable shares respectively accounted for high percentage as 80.74% and 11%. Regarding plastic waste, the average plastic waste generation rate was 17.24 g/cap/day; plastic packaging and plastic containers dominated with the high percentage, 95.64% of plastic waste. Plastic shopping bags were especially identified as the major component, accounting for 45.72% of total plastic waste. Relevant factors such as household income and household size were found to have an existing correlation to plastic waste generation in detailed composition. The household habits and behaviors of plastic waste discharge and the aspects of environmental impacts and resource consumption for plastic waste disposal alternatives were also evaluated.

Investigation of the system ThO2-NpO2-P2O5. Solid solutions of thorium-neptunium (IV) phosphate-diphosphate

International Nuclear Information System (INIS)

Dacheux, N.; Thomas, A.C.; Brandel, V.; Genet, M.

1998-01-01

Considering that phosphate matrices could be potential candidates for the immobilization of actinides or for the final disposal of the excess plutonium from dismantled nuclear weapons, the chemistry of thorium phosphates has been re-examined. In the ThO 2 -P 2 O 5 system, the thorium phosphate-diphosphate Th 4 (PO 4 ) 4 P 2 O 7 (TPD) can be synthesized by wet and dry chemical processes. The substitution of thorium by other tetravalent actinides like uranium or plutonium can be obtained for 0 4-x Np x (PO 4 ) 4 P 2 O 7 (TNPD) with 0 4+ by Np 4+ in the TPD structure is evaluated to 2.08 (which corresponds to about 52 mol% of thorium replaced by neptunium (IV)). The field of existence of solid solutions Th 4-x U -x Np -x Pu U x U Np x Np Pu x Pu (PO 4 )4P 2 O 7 has been calculated. These solid solutions should be synthesized for 5x U +7x Np +9x Pu ≤15. In the NpO 2 -P 2 O 5 system, the unit cell parameters of Np 2 O(PO 4 ) 2 were refined by analogy with U 2 O(PO 4 ) 2 which crystallographic data have been published recently. For Np 2 O(PO 4 ) 2 the unit cell is orthorhombic with the following cell parameters: a=7.033(2)A, b=9.024(3)A, c=12.587(6)A and V=799(1)A 3 . The unit cell parameter obtained for α-NpP 2 O 7 (a=8.586(1)A) is in good agreement with those already reported in literature. (orig.)

Extended networks, porous sheets, and chiral frameworks. Thorium materials containing mixed geometry anions: Structures and properties of Th(SeO3)(SeO4), Th(IO3)2(SeO4)(H2O)3.H2O, and Th(CrO4)(IO3)2

International Nuclear Information System (INIS)

Sullens, Tyler A.; Almond, Philip M.; Byrd, Jessica A.; Beitz, James V.; Bray, Travis H.; Albrecht-Schmitt, Thomas E.

2006-01-01

Three novel Th(IV) compounds containing heavy oxoanions, Th(SeO 3 )(SeO 4 ) (1), Th(IO 3 ) 2 (SeO 4 )(H 2 O) 3 .H 2 O (2), and Th(CrO 4 )(IO 3 ) 2 (3), have been synthesized under mild hydrothermal conditions. Each of these three distinct structures contain trigonal pyramidal and tetrahedral oxoanions. Compound 1 adopts a three-dimensional structure formed from ThO 9 tricapped trigonal prisms, trigonal pyramidal selenite, SeO 3 2- , anions containing Se(IV), and tetrahedral selenate, SeO 4 2- , anions containing Se(VI). The structure of 2 contains two-dimensional porous sheets and occluded water molecules. The Th centers are found as isolated ThO 9 tricapped trigonal prisms and are bound by four trigonal pyramidal iodate anions, two tetrahedral selenate anions, and three coordinating water molecules. In the structure of 3, the Th(IV) cations are found as ThO 9 tricapped trigonal prisms. Each Th center is bound by six IO 3 1- anions and three CrO 4 2- anions forming a chiral three-dimensional structure. Second-harmonic generation of 532nm light from 1064nm radiation by a polycrystalline sample of 3 was observed. Crystallographic data (193K, MoKα, λ=0.71073): 1; monoclinic, P2 1 /c; a=7.0351(5)A, b=9.5259(7)A, c=9.0266(7)A, β=103.128(1), Z=4, R(F)=2.47% for 91 parameters with 1462 reflections with I>2σ(I); 2, monoclinic, P2 1 /n, a=7.4889(9)A, b=8.002(1)A, c=20.165(3)A, β=100.142(2), Z=4, R(F)=4.71% for 158 parameters with 2934 reflections with I>2σ(I); 3, orthorhombic, P2 1 2 1 2 1 , a=7.3672(5)A, b=9.3617(6)A, c=11.9201(7)A, Z=4, R(F)=2.04% for 129 parameters with 2035 reflections with I>2σ(I)

Human factors and tidal influences on water quality of an urban river in Can Tho, a major city of the Mekong Delta, Vietnam.

Science.gov (United States)

Ozaki, Hirokazu; Co, Thi Kinh; Le, Anh Kha; Pham, Viet Nu; Nguyen, Van Be; Tarao, Mitsunori; Nguyen, Huu Chiem; Le, Viet Dung; Nguyen, Hieu Trung; Sagehashi, Masaki; Ninomiya-Lim, Sachi; Gomi, Takashi; Hosomi, Masaaki; Takada, Hideshige

2014-02-01

In this study, we focused on water quality in an urban canal and the Mekong River in the city of Can Tho, a central municipality of the Mekong Delta region, southern Vietnam. Water temperature, pH, electrical conductivity, BOD5, CODCr, Na(+), Cl(-), NH4 (+)-N, SO4 (2-)-S, NO3 (-)-N, and NO2 (-)-N for both canal and river, and tide level of the urban canal, were monitored once per month from May 2010 to April 2012. The urban canal is subject to severe anthropogenic contamination, owing to poor sewage treatment. In general, water quality in the canal exhibited strong tidal variation, poorer at lower tides and better at higher tides. Some anomalies were observed, with degraded water quality under some high-tide conditions. These were associated with flow from the upstream residential area. Therefore, it was concluded that water quality in the urban canal changed with a balance between dilution effects and extent of contaminant supply, both driven by tidal fluctuations in the Mekong River.

Phase study in Sr-Th-P-O system: Structural and thermal investigations of quaternary compounds

International Nuclear Information System (INIS)

Keskar, Meera; Phatak, Rohan; Sali, S.K.; Krishnan, K.; Dahale, N.D.; Kulkarni, N.K.; Kannan, S.

2011-01-01

The sub-solidus phase relations in Sr-Th-P-O quaternary system were determined at 1223 K in air. To confirm the formation and stability of reported phases, ternary and quaternary compounds in Sr-Th-O, Sr-P-O, Th-P-O and Sr-Th-P-O systems were synthesized by solid state reactions of SrCO 3 , ThO 2 and NH 4 H 2 PO 4 in desired molar proportions at 1223 K. A pseudo-ternary phase diagram of SrO-ThO 2 -P 2 O 5 system was drawn on the basis of the phase analysis of various phase mixtures and phase fields were established by powder X-ray diffraction. In the phase diagram, three quaternary compounds SrTh(PO 4 ) 2 , SrTh 4 (PO 4 ) 6 and Sr 7 Th(PO 4 ) 6 were identified. When heated in air at 1673 K, these compounds decompose to ThO 2 . Structures of SrTh(PO 4 ) 2 , SrTh 4 (PO 4 ) 6 and Sr 7 Th(PO 4 ) 6 were derived from X-ray powder data using the Rietveld refinement method. Thermal expansion behaviors of SrTh(PO 4 ) 2 , SrTh 4 (PO 4 ) 6 and Sr 7 Th(PO 4 ) 6 were investigated using high-temperature X-ray diffraction in the temperature range of 298-1273 K.

Effect of high content nano-thoria addition on the properties of tungsten electrode

International Nuclear Information System (INIS)

Wang Fazhan; Zhuge Fei; Zhang Hui; Ding Bingjun

2003-01-01

By hot swaging, the nano-composite W-4.5%ThO 2 cathode was fabricated. A comparative investigation has been made on the operation characteristics for a conventional W-2%ThO 2 cathode, a conventional W-4%ThO 2 cathode and a nano-composite W-4.5%ThO 2 cathode. The results showed that the arc starting and arc voltage-current characteristic of the nano-composite W-4.5%ThO 2 electrode was the best among the three cathodes. These operating characteristics depended on the content and the size of thoria. The anti-erosion ability of the nano-composite W-4.5%ThO 2 cathode was slightly better than that of conventional W-4%ThO 2 cathode, but was obviously improved as compared to W-2%ThO 2 cathode, indicating that the content of thoria governs the resistance to arc erosion of the electrodes

High-pressure phase transformations of fluorite-type dioxides

International Nuclear Information System (INIS)

Lin-Gun Liu

1980-01-01

Phase transformations in six fluorite-type dioxides ('TbO 2 ', PbO 2 , 'PrO 2 ', CeO 2 , UO 2 and ThO 2 in the order of increasing cation size, where the quotation marks indicate non-stoichiometric materials) have been investigated in the diamond-anvil press coupled with laser heating. Together with earlier work, the results show that the post-fluorite phase transformations of these dioxides fall into two groups. The smaller cation group (HfO 2 , ZrO 2 and 'TbO 2 ') transforms to a cotunnite or a distorted cotunnite-type structure at pressures in the vicinity of 100 kbar and at about 1000 0 C. The larger cation group (from PbO 2 to ThO 2 ) is believed to transform to a different type of orthorhombic modification at high pressures. It is plausible that this high-pressure phase may possess a Ni 2 Si-related structure, as was observed in ThO 2 and 'PrO 2 ' at pressures greater than 150 and 200 kbar, respectively. (orig./ME)

Peculiarities Of The Chemical Bond In Thorium Compounds And Fine X-Ray Photoelectron And O4,5(Th) Emission Spectral Structure

International Nuclear Information System (INIS)

Teterin, Yu.A.; Teterin, A.Yu.; Utkin, I.O.; Ivanov, K.E.; Terehov, V.A.; Ryzhkovc, M.V.; Vukchevich, L.J.

2002-01-01

On the basis of the XPS (0 - -1000 eV), x-ray 04 5(Th) low-energy (0 - 50eV) emission fine spectral structure parameters, and theoretical calculations results for electronic structure of Th, ThO 2 , and ThF 4 , the study of the Th6p-,5f- electronic states was carried out. As a result, despite the absence of the Th5f electrons in atomic Th, the Th5f atomic orbitals were established to be able to participate in the molecular orbital formation in thorium dioxide and tetrafluoride. In the MOLCAO approximation it enabled to suggest that the filled Th5f states exist in thorium compounds

Size of oxide vacancies in fluorite and perovskite structured oxides

DEFF Research Database (Denmark)

Chatzichristodoulou, Christodoulos; Norby, Poul; Hendriksen, Peter Vang

2015-01-01

An analysis of the effective radii of vacancies and the stoichiometric expansion coefficient is performed on metal oxides with fluorite and perovskite structures. Using the hard sphere model with Shannon ion radii we find that the effective radius of the oxide vacancy in fluorites increases...... with increasing ion radius of the host cation and that it is significantly smaller than the radius of the oxide ion in all cases, from 37% smaller for HfO2 to 13 % smaller for ThO2. The perovskite structured LaGaO3 doped with Sr or Mg or both is analyzed in some detail. The results show that the effective radius...... of an oxide vacancy in doped LaGaO3 is only about 6 % smaller than the oxide ion. In spite of this the stoichiometric expansion coefficient (a kind of chemical expansion coefficient) of the similar perovskite, LaCrO3, is significantly smaller than the stoichiometric expansion coefficient of the fluorite...

Transfer of atmospheric tritiated water to foliage and fruit of crops

International Nuclear Information System (INIS)

Fellows, R.J.; Cataldo, D.A.; Ligotke, M.W.; Napier, B.A.

1993-01-01

Tritiated water (THO) released to the environment from the effluent streams of nuclear reactors may be easily assimilated by organisms through metabolic fixation following foliar interception of THO vapor. This study was initiated to characterize atmospheric THO exchange parameters in two crops agronomically important to eastern Washington, grape (Vitus vinifera) and alfalfa (Medicago sativa). Short-term exposures using atmospheric THO concentrations ranging from 458 to 1,300,900 pCi/m 3 indicated no statistically significant concentration influences on THO exchange into the leaf tissue free-water (TFW) and organically bound tritium (OBT) of the leaves of either species. Long-term exposures indicated that equilibration of the leaf TFW with atmospheric THO concentrations occurred within 24 to 48 h for both species while equilibration of grape TFW appeared to take over 20 days. The rate of THO saturation of the foliage TFW appeared to be directly related to the stomatal resistance of the leaves and fruit. Desorption rates from both leaves and fruit were greater in the light than in the dark, again correlating with stomatal resistance. More than 90% of the absorbed THO was lost from the leaf TFW pool within 24 h following cessation of exposure for both species, while loss of THO from grape TFW and OBT pools was minimal. It appeared that more than 95 to 98% of the THO found in the TFW and OBT pools of the grape fruit was of atmospheric origin and not from transport from other parts of the plant

Structural analysis by load combination for conceptual design of HCCR TBM-set

Energy Technology Data Exchange (ETDEWEB)

Lee, Dong Won, E-mail: dwlee@kaeri.re.kr [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Jin, Hyung Gon; Lee, Eo Hwak; Kim, Suk-Kwon; Yoon, Jae Sung; Park, Seong Dae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Shin, Kyu In [Gentec Co., Daejeon (Korea, Republic of); Cho, Seungyon [National Fusion Research Institute, Daejeon (Korea, Republic of)

2016-11-01

Highlights: • The structural analyses of the load combination are performed for the HCCR TBM-set. • Structural analyses are performed with the conventional CFD and FEM codes (ANSYS-CFX and ANSYS). • The results of stresses and deformations for all the loads conditions are confirmed to meet the design criteria. - Abstract: Using a conceptual design of the Korean Helium Cooled Ceramic Reflector (HCCR) Test Blanket Module (TBM) including the TBM-shield for testing in ITER, a structural analysis is performed according to the selected Load Combinations (LCs), which is described in the TBM Port Plug (TBM PP) System Load Specifications. Single load analyses are performed such as dead weight (DW), operating pressure (PresO), operating temperature (THO), electromagnetic (EM; MD-I, MD-II, and MD-IV), seismic (SL-1, SL-2, and SMHV), and in-TBM LOCA-IV. In addition, their results are superposed for the selected LCs. Through an analysis with 14 single load cases and 10 LC cases, it is confirmed that all load combination results meet the design criteria from the stress breakdown analysis according to the RCC-MRx.

Fishing fleet profiling methodology

National Research Council Canada - National Science Library

Ferraris, Jocelyne

2002-01-01

A fishing fleet profile aims tho assist in understanding the complexity and structure of fisheries from a technical and socio-economic point of view, or from the point of view of fishing strategies...

Preparation of high quality zirconium oxychloride from zircon of Vietnam

International Nuclear Information System (INIS)

Ngo Van Tuyen; Vu Thanh Quang; Trinh Giang Huong; Vuong Huu Anh

2007-01-01

This paper introduces a sodium hydroxide decomposition method for zirconium oxychloride production from zircon sand of Vietnam such as Ha Tinh, Hue, Binh Thuan seaside. Techniques for separation of impurities in ZOC final product such as SiO 2 , Fe 2 O 3 , TiO 2 , rare earths, uranium, and thorium have also been introduced. Content of uranium and thorium in the final product of ZOC is less than 1 ppm. (author)

A pragmatic multicentre randomised controlled trial comparing stapled haemorrhoidopexy with traditional excisional surgery for haemorrhoidal disease: the eTHoS study.

Science.gov (United States)

Watson, Angus Jm; Cook, Jonathan; Hudson, Jemma; Kilonzo, Mary; Wood, Jessica; Bruhn, Hanne; Brown, Steven; Buckley, Brian; Curran, Finlay; Jayne, David; Loudon, Malcolm; Rajagopal, Ramesh; McDonald, Alison; Norrie, John

2017-11-01

over 24 months the TH group had significantly better EQ-5D-3L scores (-0.073, 95% confidence interval -0.140 to -0.006; p  = 0.0342). Symptoms and further interventions were significantly fewer in the TH arm at 24 months. Continence was better in the TH arm and tenesmus occurred less frequently. The number of serious adverse events reported was 24 out of 337 (7.1%) for participants who received SH and 33 out of 352 (9.4%) for those who received TH. There were two deaths in the SH arm, both unrelated to the eTHoS (either Traditional Haemorrhoidectomy or Stapled haemorrhoidopexy for haemorrhoidal disease) study. Patient preference did not seem to influence the treatment difference. SH was dominated by TH as it cost more and was less effective. The net benefit for the TH arm was higher than that for the SH arm. Neither the participants nor the assessors were masked to treatment assignment and final recruitment was slightly short of the total target of 800. There were also substantial missing follow-up data. While patients who received SH had less short-term pain, after 6 weeks, recurrence rates, symptoms, re-interventions and quality-of-life measures all favoured TH. In addition, TH is cheaper. As part of a tailored management plan for haemorrhoids, TH should be considered over SH as the surgical treatment of choice for haemorrhoids refractory to clinic-based interventions. Perform an updated meta-analysis incorporating recently conducted European trials [eTHoS, HubBLe (haemorrhoidal artery ligation versus rubber band ligation for the management of symptomatic second-degree and third-degree haemorrhoids) and LingaLongo (Cost-effectiveness of New Surgical Treatments for Haemorrhoidal Disease)]. Current Controlled Trials ISRCTN80061723. This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment ; Vol. 21, No. 70. See the NIHR Journals Library website

Genetic variation observed at three tetrameric short tandem repeat loci HumTHO1, TPOX, and CSF1PO--in five ethnic population groups of northeastern India.

Science.gov (United States)

Ranjan, D; Kashyap, V K

2001-01-01

This paper portrays the genetic variation observed at three tetrameric short tandem repeat (STR) loci HumTHO1, TPOX, and CSF1PO in five ethnic population groups from northeastern India. The study also specifies the suitability of use of these markers for forensic testing. The populations studied included three tribal groups (Kuki, Naga and Hmar), one Mongoloid caste group (Meitei), and a religious caste group (Manipuri Muslims). The loci were highly polymorphic in the populations, and all loci met Hardy-Weinberg expectations. No evidence for association of alleles among the loci was detected. The probability of match for the three loci of the most frequent genotype in the five population groups ranged between 2.6 x 10(-4) and 6.6 x 10(-5). The average heterozygosity among the population groups was approximately 70% with the overall extent of gene differentiation among the five groups being high (Gst = 0.046). Genetic affinity among the populations reveal very close association between the Kuki, Hmar, Naga, and Meitei. The Manipuri Muslims, despite being found in the same region, have had no admixture with these populations and maintain a substantial distance with the other groups. The genetic polymorphism data suggest that the studied systems can be used for human identity testing to estimate the frequency of a multiple locus STR DNA profile in population groups of northeastern India.

Coordination polyhedra ThOn in crystal structure

International Nuclear Information System (INIS)

Shevchenko, A.P.; Serezhkin, V.N.; Mikhajlov, Yu.N.

2000-01-01

The environment peculiarities of Th(4) 107 atoms in 93 oxygen-containing compounds were studied using the Voronoi-Dirichlet (VD) polyhedrons. It was determined that in case of high coordination number (CN ≥ 6) of thorium atoms the volume of their VD polyhedrons did not practically depend on CN Th and constituted 11.9 (4) A 3 . The volume of the classical coordination polyhedrons, namely, ThO n , ZrO n and U 4 O n ones, was determined to depend linearly on the coordination number. It was shown that in case CN [ru

Apparatus for the Measurement of Air Blast Pressures by Means of Piezoelectric Gauges

Science.gov (United States)

1946-03-01

boam-brightenor atare or in tho voltage at tho cathode of tho cathodo-ray tubo, whether duo to olther 60-oycle hum or lino-voltage fluctuations, aro...AGENC r (Not Knowa-)- P.A. NO (None) TRANSLATING AGENCY DATE: Mar𔃻+5 COUNTRY: U.S. LANGUAGE: PAGES: REMARKS: English I 225 I...11. S 1 English PAUS 225 •UMTtATKMS ntntOfl. tables. cHarrs Description and requirements are given of an apparatus used for

Formation, Stability, and Chemistry of Tetravalent Actinide Nanocrystals

Energy Technology Data Exchange (ETDEWEB)

Yang, Ping [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Aguirre Castiblanco, Nestor Fabian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2018-02-06

First database with almost 4000 stable structures for thorium dioxide (ThO₂)_n (n≤8) calculated with density functional theory. The figure shows the lowest energy minima for different units of ThO₂ and the energy landscape generated by the found stable structures for Th₈O₁₆. This highlights the structural richness of the ThO interactions.

Study by X-ray diffraction of structure modifications induced by pressure in different actinide compounds: AnO2 dioxides (An=Th, Pu, Am), AnCl4 tetrachlorides (An=Th, U), UBx borides (x=2,4,12) and the carbide UC2

International Nuclear Information System (INIS)

Dancausse, J.P.

1991-01-01

Structural transitions, induced by pressure, of actinide compounds are studied by X-ray diffraction, the determination of incompressibility is also studied at atmospheric pressure. The crystal structure of ThO 2 , PuO 2 and AmO 2 evolves, near 40 MPa from a fcc lattice to an orthorhombic lattice. Incompressibility values associated to UO 2 and NpO 2 incompressibility evidence an important discontinuity between UO 2 and NpO 2 and other dioxides due to their different electronic structure. Tetragonal ThCl 4 and UCl 4 undergo a structure transition respectively at 2 and 5 GPa. UCl 4 becomes monoclinic and its color changes. At higher pressure these compounds become progressively amorphous. The crystal structure of uranium borides is not changed up to 50 GPa. UC 2 presents a phase transition at 17.6 GPa from a tetragonal to a hexagonal lattice

Outcomes after medical and surgical interventions in horses with temporohyoid osteoarthropathy.

Science.gov (United States)

Espinosa, P; Nieto, J E; Estell, K E; Kass, P H; Aleman, M

2017-11-01

Temporohyoid osteoarthropathy (THO) is a cause of neurological disease in horses that is characterised by facial and vestibulocochlear nerve deficits. Studies reporting and comparing survival following medical or surgical treatment of THO are lacking. To compare survival and prognosis in horses with THO treated medically or surgically, and to report surgical complications. Retrospective study. The medical records of horses diagnosed with THO were retrieved, and data on signalment, clinical signs and duration, corneal ulceration and bilateral occurrence were recorded. Neurological severity was graded according to clinical signs. Preoperative radiographic and endoscopic images were graded according to the severity of changes. Factors potentially affecting survival and treatment were compared using Cox proportional hazards regression. A total of 77 horses were identified as having THO during the period 1990-2014. Of these, 25 horses underwent ceratohyoid ostectomy (CHO) and eight underwent partial stylohyoid ostectomy (PSHO). Thirteen of 20, one of 25 and one of eight horses treated by medical therapy, CHO and PSHO, respectively, died or were subjected to euthanasia as a consequence of THO. Compared with CHO, medical therapy was significantly associated with nonsurvival, but there were no significant differences in survival between horses undergoing PSHO and medical therapy. The duration of clinical signs, and neurological, radiographic and endoscopic grades were not associated with survival of THO. However, the age of the horse was significantly associated with poorer survival. Survival time was significantly shorter in the medical therapy group compared with the two surgical groups combined, but did not differ significantly between the two surgical groups. No significant difference between groups was seen in the incidence of surgical complications (33.3% in the PSHO and 22.2% in the CHO group). This was a nonrandomised study of treatment effects on survival and

Pro-Amateur Observatories as a Significant Resource for Professional Astronomers - Taurus Hill Observatory

Science.gov (United States)

Haukka, H.; Hentunen, V.-P.; Nissinen, M.; Salmi, T.; Aartolahti, H.; Juutilainen, J.; Vilokki, H.

2013-09-01

Taurus Hill Observatory (THO), observatory code A95, is an amateur observatory located in Varkaus, Finland. The observatory is maintained by the local astronomical association of Warkauden Kassiopeia [8]. THO research team has observed and measured various stellar objects and phenomena. Observatory has mainly focuse d on asteroid [1] and exoplanet light curve measurements, observing the gamma rays burst, supernova discoveries and monitoring [2]. We also do long term monitoring projects [3]. THO research team has presented its research work on previous EPSC meetings ([4], [5],[6], [7]) and got very supportive reactions from the European planetary science community. The results and publications that pro-amateur based observatories, like THO, have contributed, clearly demonstrates that pro-amateurs area significant resource for the professional astronomers now and even more in the future.

Phase Behavior and Equations of State of the Actinide Oxides

Science.gov (United States)

Chidester, B.; Pardo, O. S.; Panero, W. R.; Fischer, R. A.; Thompson, E. C.; Heinz, D. L.; Prescher, C.; Prakapenka, V. B.; Campbell, A.

2017-12-01

The distribution of the long-lived heat-producing actinide elements U and Th in the deep Earth has important implications for the dynamics of the mantle and possibly the energy budget of Earth's core. The low shear velocities of the Large Low-Shear Velocity Provinces (LLSVPs) on the core-mantle boundary suggests that these regions are at least partially molten and may contain concentrated amounts of the radioactive elements, as well as other large cations such as the rare Earth elements. As such, by exploring the phase behavior of actinide-bearing minerals at extreme conditions, some insight into the mineralogy, formation, and geochemical and geodynamical effects of these regions can be gained. We have performed in situ high-pressure, high-temperature synchrotron X-ray diffraction experiments and calculations on two actinide oxide materials, UO2 and ThO2, to determine their phase behavior at the extreme conditions of the lower mantle. Experiments on ThO2 reached 60 GPa and 2500 K, and experiments on UO2 reached 95 GPa and 2500 K. We find that ThO2 exists in the fluorite-type structure to 20 GPa at high temperatures, at which point it transforms to the high-pressure cotunnite-type structure and remains thus up to 60 GPa. At room temperature, an anomalous expansion of the fluorite structure is observed prior to the transition, and may signal anion sub-lattice disorder. Similarly, UO2 exists in the fluorite-type structure at ambient conditions and up to 28 GPa at high temperatures. Above these pressures, we have observed a previously unidentified phase of UO2 with a tetragonal structure as the lower-temperature phase and the cotunnite-type phase at higher temperatures. Above 78 GPa, UO2 undergoes another transition or possible dissociation into two separate oxide phases. These phase diagrams suggest that the actinides could exist as oxides in solid solution with other analogous phases (e.g. ZrO2) in the cotunnite-type structure throughout much of Earth's lower mantle.

Preparation and X-ray diffraction characterization of Th1-xBixO2-0.5x (where x= 0 to 0.5) solid solutions

International Nuclear Information System (INIS)

Kanrar, Buddhadev; Misra, N.L.

2015-01-01

Solid solutions of ThO 2 and Bi 2 O 3 were prepared by solid state reactions of these oxides. X-ray diffraction studies indicated that Bi +3 up to 50 at% can be dissolved in ThO 2 lattice. Rietveld refinement of the XRD patterns indicated single phase solid solutions up to 50 atom% of Bi +3 in ThO 2 lattice. The cell parameters of the solid solutions were found to decrease with increasing amount of Bi +3 in the lattice. (author)

Temporal and spatial assessment of river surface water quality using multivariate statistical techniques: a study in Can Tho City, a Mekong Delta area, Vietnam.

Science.gov (United States)

Phung, Dung; Huang, Cunrui; Rutherford, Shannon; Dwirahmadi, Febi; Chu, Cordia; Wang, Xiaoming; Nguyen, Minh; Nguyen, Nga Huy; Do, Cuong Manh; Nguyen, Trung Hieu; Dinh, Tuan Anh Diep

2015-05-01

The present study is an evaluation of temporal/spatial variations of surface water quality using multivariate statistical techniques, comprising cluster analysis (CA), principal component analysis (PCA), factor analysis (FA) and discriminant analysis (DA). Eleven water quality parameters were monitored at 38 different sites in Can Tho City, a Mekong Delta area of Vietnam from 2008 to 2012. Hierarchical cluster analysis grouped the 38 sampling sites into three clusters, representing mixed urban-rural areas, agricultural areas and industrial zone. FA/PCA resulted in three latent factors for the entire research location, three for cluster 1, four for cluster 2, and four for cluster 3 explaining 60, 60.2, 80.9, and 70% of the total variance in the respective water quality. The varifactors from FA indicated that the parameters responsible for water quality variations are related to erosion from disturbed land or inflow of effluent from sewage plants and industry, discharges from wastewater treatment plants and domestic wastewater, agricultural activities and industrial effluents, and contamination by sewage waste with faecal coliform bacteria through sewer and septic systems. Discriminant analysis (DA) revealed that nephelometric turbidity units (NTU), chemical oxygen demand (COD) and NH₃ are the discriminating parameters in space, affording 67% correct assignation in spatial analysis; pH and NO₂ are the discriminating parameters according to season, assigning approximately 60% of cases correctly. The findings suggest a possible revised sampling strategy that can reduce the number of sampling sites and the indicator parameters responsible for large variations in water quality. This study demonstrates the usefulness of multivariate statistical techniques for evaluation of temporal/spatial variations in water quality assessment and management.

Charged defects during alpha-irradiation of actinide oxides as revealed by Raman and luminescence spectroscopy

International Nuclear Information System (INIS)

Mohun, R.; Desgranges, L.; Léchelle, J.; Simon, P.; Guimbretière, G.; Canizarès, A.; Duval, F.; Jegou, C.; Magnin, M.; Clavier, N.; Dacheux, N.; Valot, C.; Vauchy, R.

2016-01-01

We have recently evidenced an original Raman signature of alpha irradiation-induced defects in UO 2 . In this study, we aim to determine whether the same signature also exists in different actinide oxides, namely ThO 2 and PuO 2 . Sintered UO 2 and ThO 2 were initially irradiated with 21 MeV He 2+ ions using a cyclotron device and were subjected to an in situ luminescence experiment followed by Raman analysis. In addition, a PuO 2 sample which had accumulated self-irradiation damage due to alpha particles was investigated only by Raman measurement. Results obtained for the initially white ThO 2 showed that a blue color appeared in the irradiated areas as well as luminescence signals during irradiation. However, Raman spectroscopic analysis showed the absence of Raman signature in ThO 2 . In contrast, the irradiated UO 2 and PuO 2 confirmed the presence of the Raman signature but no luminescence peaks were observed. The proposed mechanism involves electronic defects in ThO 2 , while a coupling between electronic defects and phonons is required to explain the Raman spectra for UO 2 and PuO 2 .

Investigation of tritium and 233U breeding in a fission-fusion hybrid reactor fuelling with ThO2

International Nuclear Information System (INIS)

Yildiz, K.; Sahin, S.; Sahin, H. M.; Acir, A.; Yalcin, S.; Altinok, T.; Bayrak, M.; Alkan, M.; Durukan, O.

2007-01-01

In the world, thorium reserves are three times more than natural Uranium reserves. It is planned in the near future that nuclear reactors will use thorium as a fuel. Thorium is not a fissile isotope because it doesn't make fission with thermal neutrons so it could be converted to 2 33U isotope which has very high quality fission cross-section with thermal neutrons. 2 33U isotope can be used in present LWRs as an enrichment fuel. In the fusion reactors, tritium is the most important fossil fuel. Because tritium is not natural isotope, it has to be produced in the reactor. The purpose of this work is to investigate the tritium and 2 33U breeding in a fission-fusion hybrid reactor fuelling with ThO 2 for Δt=10 days during a reactor operation period in five years. The neutronic analysis is performed on an experimental hybrid blanket geometry. In the center of the hybrid blanket, there is a line neutron source in a cylindrical cavity, which simulates the fusion plasma chamber where high energy neutrons (14.1 MeV) are produced. The conventional fusion reaction delivers the external neutron source for blankets following, 2 D + 3 T →? 4 He (3.5 MeV) + n (14.1 MeV). (1) The fuel zone made up of natural-ThO 2 fuel and it is cooled with different coolants. In this work, five different moderator materials, which are Li 2 BeF 4 , LiF-NaF-BeF 2 , Li 2 0Sn 8 0, natural Lithium and Li 1 7Pb 8 3, are used as coolants. The radial reflector, called tritium breeding zones, is made of different Lithium compounds and graphite in sandwich structure. In the work, eight different Lithium compounds were used as tritium breeders in the tritium breeding zones, which are Li 3 N, Li 2 O, Li 2 O 2 , Li 2 TiO 3 , Li 4 SiO 3 , Li 2 ZrO 3 , LiBr and LiH. Neutron transport calculations are conducted in spherical geometry with the help of SCALE4.4A SYSTEM by solving the Boltzmann transport equation with code CSAS and XSDRNPM, under consideration of unresolved and resolved resonances, in S 8 -P 3

Continuous-Tone Electrostatic Electrography

Science.gov (United States)

1948-12-15

TRANSLATOR <»>: Schaf fort, R.M. Williams, D.I. WfOiwp, L*E, = TYRS. SERIES . NUMBER AND PERIOD OF R*RO«T COVERED: Quarterly Progress ropt fjT...a passing wire (a ohöft distance abo’ve tho plato) or a series qf point a or othor oourpoo of aom<^> ^mat similar geometry hold at high voltage In... temporale of tho plat©» If tho dark decay i„s not of thermal : origin, an exponential typo of decay would still ho anticipated. Ih such caoe

Development Of Protocols For Simultaneous Measurements Of Rn, Tn Using Nuclear Track Detectors And Trial Application In Mining Areas Of Vietnam

International Nuclear Information System (INIS)

Bui Dac Dung; Trinh Van Giap; Le Dinh Cuong; Tran Khanh Minh; Nguyen Huu Quyet; Nguyen Van Khanh; Tran Ngoc Toan

2013-01-01

Radioactive gases Radon (Rn) and Thoron (Tn) contribute of more than 50% of natural radiation dose. However, separate measurements of Rn and Tn have not been paid enough attention. An Intergovernmental Cooperation Project was conducted at the Institute for Nuclear Science and Technology with the help from Hungarian experts. The main tasks of the project were to finalize 02 protocols for simultaneous measurements of Rn and Tn using nuclear track detectors and to test these protocols in investigating the concentrations of Rn and Tn, calculating the natural dose due to Rn and Tn, and evaluating the increased radiation dose and radiation safety due to mining activities. Main results of the project include 02 protocols for simultaneous measurements of Rn and Tn and the test results in the mining areas. Rn and Tn concentrations inside the coal mining tunnels are in the average level of Vietnam and the world. Tn concentration inside the factory for separating Zircon at the Ha Tinh Zircon Processing Plant was found to be very high, up to 2931 Bq/m 3 . Based on annual effective dose calculation, workers inside the factory for separating Zircon at the Ha Tinh Zircon Processing Plant could receive an annual effective dose due to Rn and Tn of 4.890 mSv/year, and the increasing dose of 4.710 mSv/year is for higher than 1 mSv/year recommended by the IAEA. (author)

Anti-UV Radiation Textiles Designed by Embracing with Nano-MIL (Ti, In)-Metal Organic Framework.

Science.gov (United States)

Emam, Hossam E; Abdelhameed, Reda M

2017-08-23

Protective textiles against harmful solar radiation are quite important materials for outdoor workers to secure their skin from several diseases. Current report focuses on production of anti-ultraviolet radiation (UVR) textiles by incorporation of nano-metal-organic frameworks (n-MOFs). Two different MIL-MOFs, namely, MIL-68(In)-NH 2 and MIL-125(Ti)-NH 2 , were immediately formed inside natural textiles (cotton and silk) matrix in nano size using quite simple and one-pot process. The formation of n-MIL-MOFs inside textiles were confirmed by using electron microscope and X-ray diffraction. Different size and morphology were seen depending on textile type reflecting the textiles' chemical composition role in the nature of prepared MIL-MOFs. For MIL-68(In)-NH 2 , particles with size distribution of 70.6-44.5 nm in cotton and 81.3-52.2 nm in silk were detected, while crystalline disc of MIL-125(Ti)-NH 2 was clearly seen inside textiles. The natural textiles exhibited full UVR blocking after modification, and the UV protection factor (UPF) was linearly proportional with MIL-MOFs and metal contents. Whatever metal type, direct incorporation of MIL-MOF contents greater than or equal to 10.4 g/kg was sufficient to attain excellent UV blocking property. Although 38.5-41.0% of MIL-MOFs was lost during five washings, the washed samples showed very good blocking rate (UPF = 26.7-36.2) supporting good laundering durability.

Contribution to Taxonomy and Distribution of the Genus Elaphropoda (Hymenoptera: Apidae: Apinae in Vietnam

Directory of Open Access Journals (Sweden)

Nguyen, Minh Phuong

2016-04-01

Full Text Available Taxonomic notes on the genus Elaphropoda Lieftinck, 1966 (Hymenoptera: Apidae from Vietnam are presented. Two species of the genus are reported: Elaphropoda percarinata (Cockerell, 1930 was first recorded from Vietnam based on specimens collected from Ha Tinh province in 1998, and is reconfirmed with a specimens collected from Bac Kan province in the Northeastern part of the country in this study, and Elaphropoda khasiana (Schulz, 1906 is recorded from Vietnam for the first time. Redescriptions of the male of E. percarinata and the female of E. khasiana are given with illustrations.

Managing risks in the fisheries supply chain using House of Risk Framework (HOR) and Interpretive Structural Modeling (ISM)

Science.gov (United States)

Nguyen, T. L. T.; Tran, T. T.; Huynh, T. P.; Ho, T. K. D.; Le, A. T.; Do, T. K. H.

2018-04-01

One of the sectors which contributes importantly to the development of Vietnam economy is fishery industry. However, during recent year, it has been witnessed many difficulties on managing the performance of the fishery supply chain operations as a whole. In this paper, a framework for supply chain risk management (SCRM) is proposed. Initially, all the activities are mapped by using Supply Chain Operations Reference (SCOR) model. Next, the risk ranking is analyzed in House of Risk. Furthermore, interpretive structural modeling (ISM) is used to identify inter-relationships among supply chain risks and to visualize the risks according to their levels. For illustration, the model has been tested in several case studies with fishery companies in Can Tho, Mekong Delta. This study identifies 22 risk events and 20 risk agents through the supply chain. Also, the risk priority could be used for further House of Risk with proactive actions in future studies.

A Report of Research on Detection of Deception

Science.gov (United States)

1952-09-15

roce -dt or tho ’ ,oo other oubJoao wore ~,ncorinloti2.) Also stwiplo3 of the heart rate worn -’ Akon following the ribJootnt rcioprinn.o to th* ncutral...v.nr worn t’. akon , the only differonce in tho situation being that the S’s ir ,tvuin tho auditory stiil (four each at intervals of a minute as soon as...show’- 1I mr 2.* In this caso I or 2 is subtracted from aJ. inda~x readlings t akon (ri r’ nofrfti-ot. (2) h O Icction ol the indicati~ng imotnr for a

Determination of thermo-physical properties of (Th,Ce)O2 MOX using classical molecular dynamics simulations

International Nuclear Information System (INIS)

Ghosh, P.S.; Arya, A.; Dey, G.K.; Somayajulu, P.S.

2015-01-01

This paper calculates lattice thermal expansion (LTE) and thermal conductivity (TC) of Th 1-x Ce x O 2 (x=0.0, 0.0625 and 0.125) MOX using classical molecular dynamic simulations. The potential parameters of Coulomb-Buckingham function for Th-O, Ce-O and O-O were determined by fitting experimentally available LTE data for pure ThO 2 and CeO 2 . The calculated linear thermal expansion coefficients in the temperature range 300-1500K for ThO 2 , CeO 2 , Th 93.75 Ce 6.25 O 2 and Th 87.5 Ce 12.5 O 2 are 10.61, 13.08, 10.78 and 10.93x10 -6 K -1 , respectively. The MD calculated LTE values of ThO 2 and (Th,Ce)O 2 MOX are slightly higher than the experimentally determined values. The MD calculated TC values of ThO 2 and (Th,Ce)O 2 MOX in the high temperature range (600 to 1200 K) our results accords very well with the experimental measurements and at the low temperature range (300-500 K) our results are slightly different from some experimental results as the difference comes from our presumption that the dominant mechanism for phonon scattering is the Umklapp process. (author)

Nuclear surveillance of mRNP formation

DEFF Research Database (Denmark)

Jensen, Torben Heick

Proper formation of mRNP requires co-transcriptional loading of proteins onto nascent transcripts. Mutations in several genes involved in mRNA processing, mRNP assembly and nuclear export lead to production of aberrant mRNPs that are retained in transcription site-associated foci. Retention...... and degradation of transcripts depend on the nuclear exosome of 3’-5’ exonucleases.We have studied connections between mRNP assembly and quality control in the yeast S. cerevisiae using mutants of the THO complex. THO is implicated in co-transcriptional mRNP assembly, but its precise role is not known. Genetic...... and biochemical data now show that a defective THO complex negatively impacts mRNA 3’-end processing. We are currently trying to understand the relationship between this phenomenon and mRNP quality control. Retention of mRNP in THO mutants is dependent on the nuclear exosome component Rrp6p. Using the solved...

High temperature thermophysical properties of (Th,U)O2 fuels

International Nuclear Information System (INIS)

Jarvis, T.; Banerjee, J.; Bhagat, R.K.; Ravi, K.; Sengupta, A.K.; Kutty, T.R.G.; Majumdar, S.

2000-01-01

In the present investigation thermal expansion data for sintered ThO 2 and ThO 2 containing 2,4,6,10 and 20% UO 2 pellets were measured using a high temperature dilatometer in the temperature range from ambient to 1773K in an inert atmosphere of argon

Extravascular lung water: its measurement by simultaneous pulmonary and aortic sampling and iterative convolution

International Nuclear Information System (INIS)

Giuntini, C.; Fazio, F.

1975-01-01

The inadequacy of the apparent distribution volume of THO during the first passage dilution curve (a) to account for the total lung water in in-vitro measurements in dogs and (b) to measure any increase in lung water, even in patients with obvious clinical pulmonary oedema, prompted the present investigation. Tritiated water, THO, as diffusible indicator, and human serum albumin labelled with 131 I, ALB, as intravascular tracer, are injected into the superior vena cava at the junction with the right atrium. In order to clear the aortic blood samples of recirculation, the recirculating tracers must be determined. This is accomplished by pulmonary artery sampling. Iterative convolution of the pulmonary artery dilution curves with suitable test functions eventually yields products of convolution that fit well the corresponding aortic dilution curves of THO and ALB. The test functions that yield the best fit are taken to represent the frequency functions of the transit time from pulmonary artery to aorta of THO and ALB, respectively. By applying the same procedure of iterative convolution to these frequency functions, we obtain the dilution curve of THO in the extravascular lung space. As a result of this analysis: (a) forward extrapolation is less subject to systematic errors such as overestimation of the mean transit time of ALB, i.e. of the tracer that recirculates more; and (b) the distribution volume of THO can be better defined since the dilution of THO in the extravascular lung space may be followed beyond the point of recirculation. The results indicate that both in normal subjects and in patients with left ventricular insufficiency the computed dilution curves of THO in the extravascular lung space have a long tail which is more pronounced in the patients. These findings suggest the existence in the lungs of extravascular water pools that are slowly exchanging with pulmonary water flow. This may depend both on inhomogeneities of perfusion, with lack of it at

United States-Vietnam Relations 1945-1967. Book 8 of 12

Science.gov (United States)

1971-09-20

territories t- ken from the enemy in this war, as Might be agreed upon at a later date, end also such other territories as mi~r.it voluntarily...lag controls* In consequence tho process of Giving definition 211 . the ontot’prise * A dispassionate cvpprsisSl loach ) tho United States

A prospective randomized comparison of continuous hemihepatic with intermittent total hepatic inflow occlusion in hepatectomy for liver tumors.

Science.gov (United States)

Liang, Guanlin; Wen, Tianfu; Yan, Lunan; Li, B O; Wu, Guochang; Yang, Jian; Lu, Bo; Chen, Zheyu; Liao, Zhixue; Ran, Shun; Yu, Zhang

2009-01-01

To evaluate whether continuous hemihepatic inflow occlusion (HHO) during hepatectomy can be safer than and be as effective as intermittent total hepatic inflow occlusion (THO) in reducing blood loss. Eighty patients undergoing liver resections were included in a prospective randomized study comparing the intra- and postoperative course under THO (n=40) or HHO (n=40). THO was performed with periods of 20 minutes of occlusion and 5 minutes of releasing, while HHO was performed with continuous occlusion. The surface area of liver transection, amount of blood loss, measurements of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and postoperative evolution were recorded. The two groups were similar at entry in terms of preoperative liver function and in the proportion of patients experiencing major hepatectomy. The total ischemic time of the two groups was similar (p=0.37), but the operative time in the THO group was longer than in the HHO group (p=0.02). No significant difference was found between the HHO and THO group in blood loss during liver parenchyma transection (p=0.14), the elevations of ALT and AST on the first postoperative day (ALT: p=0.12; AST: p=0.66) and postoperative morbidity (p=0.35). On the basis of our findings, if it is feasible, continuous HHO is recommended for complex liver resection.

Metabolism and risks from tritium and carbon-14 in the developing organism

International Nuclear Information System (INIS)

Gerber, G.B.; Kirchmann, R.; Hoek, J. van den

1987-01-01

In this review the risks are considered from tritium and carbon-14 to the developing organs of mammals. It mainly deals with H-3 but the conclusions are largely valid also for C-14. The metabolism and average tissue of THO as well as of organically bound tritium are discussed. Dosimetry of radiosensitive structures is also considered. 14 refs.; 2 figs.; 1 table

Study of the defect structure of ''pure'' and doped nonstoichiometric CeO2. Final report, January 1, 1965--May 31, 1977

International Nuclear Information System (INIS)

Blumenthal, R.N.

1977-11-01

The defect structure and transport properties of defects in nonstoichiometric oxides was studied based on their electrical and thermodynamic behavior. Similar studies were also made on doped-nonstoichiometric oxides to determine the effect of the ionic radii, valence and concentration of the dopant cation on the nonstoichiometric defect structure and the transport properties of these defects. The thermodynamic and electrical property study on ''pure'' and doped-nonstoichiometric CeO 2 /sub -x/ is reviewed. The combined study of the electrical conductivity, ionic transference, and thermodynamic measurements initiated on CaO-doped CeO 2 as a function of temperature, oxygen pressure and CaO content is discussed. The results of similar measurements on CeO 2 doped with other oxides (e.g., ThO 2 , Ta 2 O 5 , etc.) which have cations with different valences and ionic radii are also discussed. The primary objective of these studies was to determine the effect of ionic radii, valence and concentration of the dopant cation on (1) the nonstoichiometric behavior, (2) the thermodynamic quantities ΔantiH/sub O 2 / and ΔantiS/sub O 2 /, (3) the nonstoichiometric defect structure, (4) the electronic and ionic conductivities, and (5) the mobility of electrons and oxygen vacancies in doped CeO 2 /sub -x/

Advanced Proliferation Resistant, Lower Cost, Uranium-Thorium Dioxide Fuels for Light Water Reactors (Progress report for work through June 2002, 12th quarterly report)

International Nuclear Information System (INIS)

Mac Donald, Philip Elsworth

2002-01-01

The overall objective of this NERI project is to evaluate the potential advantages and disadvantages of an optimized thorium-uranium dioxide (ThO2/UO2) fuel design for light water reactors (LWRs). The project is led by the Idaho National Engineering and Environmental Laboratory (INEEL), with the collaboration of three universities, the University of Florida, Massachusetts Institute of Technology (MIT), and Purdue University; Argonne National Laboratory; and all of the Pressurized Water Reactor (PWR) fuel vendors in the United States (Framatome, Siemens, and Westinghouse). In addition, a number of researchers at the Korean Atomic Energy Research Institute and Professor Kwangheon Park at Kyunghee University are active collaborators with Korean Ministry of Science and Technology funding. The project has been organized into five tasks: Task 1 consists of fuel cycle neutronics and economics analysis to determine the economic viability of various ThO2/UO2 fuel designs in PWRs; Task 2 will determine whether or not ThO2/UO2 fuel can be manufactured economically; Task 3 will evaluate the behavior of ThO2/UO2 fuel during normal, off-normal, and accident conditions and compare the results with the results of previous UO2 fuel evaluations and U.S. Nuclear Regulatory Commission (NRC) licensing standards; Task 4 will determine the long-term stability of ThO2/UO2 high-level waste; and Task 5 consists of the Korean work on core design, fuel performance analysis, and xenon diffusivity measurements

Neutron multipilication factors as a function of temperature: a comparison of calculated and measured values for lattices using 233UO2-ThO2 fuel in graphite

International Nuclear Information System (INIS)

Newman, D.F.; Gore, B.F.

1978-01-01

Neutron multiplication factors calculated as a function of temperature for three graphite-moderated 233 UO 2 -ThO 2 -fueled lattices are correlated with the values measured for these lattices in the high-temperature lattice test reactor (HTLTR). The correlation analysis is accomplished by fitting calculated values of k/sub infinity/(T) to the measured values using two least-squares-fitted correlation coefficients: (a) a normalization factor and (b) a temperature coefficient bias factor. These correlations indicate the existence of a negative (nonconservative) bias in temperature coefficients of reactivity calculated using ENDF/B-IV cross-section data. Use of an alternate cross-section data set for thorium, which has a smaller resonance integral than ENDF/B-IV data, improved the agreement between calculated and measured temperature coefficients of reactivity for the three experimental lattices. The results of the correlations are used to estimate the bias in the temperature coefficient of reactivity calculated for a lattice typical of fresh 233 U recycle fuel for a high-temperature gas-cooled reactor (HTGR). This extrapolation to a lattice having a heavier fissile loading than the experimental lattices is accomplished using a sensitivity analysis of the estimated bias to alternate thorium cross-section data used in calculations of k/sub infinity/(T). The envelope of uncertainty expected to contain the actual values for the temperature coefficient of the reactivity for the 233 U-fueled HTGR lattice studied remains negative at 1600 K (1327 0 C). Although a broader base of experimental data with improved accuracy is always desirable, the existing data base provided by the HTLTR experiments is judged to be adequate for the verification of neutronic calculations for the HTGR containing 233 U fuel at its current state of development

Ground Based Support for Exoplanet Space Missions

Science.gov (United States)

Haukka, H.; Hentunen, V.-P.; Salmi, T.; Aartolahti, H.; Juutilainen, J.; Vilokki, H.; Nissinen, M.

2011-10-01

Taurus Hill Observatory (THO), observatory code A95, is an amateur observatory located in Varkaus, Finland. The observatory is maintained by the local astronomical association Warkauden Kassiopeia. THO research team has observed and measured various stellar objects and phenomena. Observatory has mainly focused to asteroid [1] and exoplanet light curve measurements, observing the gamma rays burst, supernova discoveries and monitoring [2] and long term monitoring projects [3]. In the early 2011 Europlanet NA1 and NA2 organized "Coordinated Observations of Exoplanets from Ground and Space"-workshop in Graz, Austria. The workshop gathered together proam astronomers who have the equipment to measure the light curves of the exoplanets. Also there were professional scientists working in the exoplanet field who attended to the workshop. The result of the workshop was to organize coordinated observation campaign for follow-up observations of exoplanets (e.g. CoRoT planets). Also coordinated observation campaign to observe stellar CME outbreaks was planned. THO has a lot of experience in field of exoplanet light curve measurements and therefore this campaign is very supported by the research team of the observatory. In next coming observing seasons THO will concentrate its efforts for this kind of campaigns.

Advanced Proliferation Resistant, Lower Cost, Uranium-Thorium Dioxide Fuels for Light Water Reactors (Progress report for work through June 2002, 12th quarterly report)

Energy Technology Data Exchange (ETDEWEB)

Mac Donald, Philip Elsworth

2002-09-01

The overall objective of this NERI project is to evaluate the potential advantages and disadvantages of an optimized thorium-uranium dioxide (ThO2/UO2) fuel design for light water reactors (LWRs). The project is led by the Idaho National Engineering and Environmental Laboratory (INEEL), with the collaboration of three universities, the University of Florida, Massachusetts Institute of Technology (MIT), and Purdue University; Argonne National Laboratory; and all of the Pressurized Water Reactor (PWR) fuel vendors in the United States (Framatome, Siemens, and Westinghouse). In addition, a number of researchers at the Korean Atomic Energy Research Institute and Professor Kwangheon Park at Kyunghee University are active collaborators with Korean Ministry of Science and Technology funding. The project has been organized into five tasks: · Task 1 consists of fuel cycle neutronics and economics analysis to determine the economic viability of various ThO2/UO2 fuel designs in PWRs, · Task 2 will determine whether or not ThO2/UO2 fuel can be manufactured economically, · Task 3 will evaluate the behavior of ThO2/UO2 fuel during normal, off-normal, and accident conditions and compare the results with the results of previous UO2 fuel evaluations and U.S. Nuclear Regulatory Commission (NRC) licensing standards, · Task 4 will determine the long-term stability of ThO2/UO2 high-level waste, and · Task 5 consists of the Korean work on core design, fuel performance analysis, and xenon diffusivity measurements.

Ligand induced shape transformation of thorium dioxide nanocrystals.

Science.gov (United States)

Wang, Gaoxue; Batista, Enrique R; Yang, Ping

2018-04-27

Nanocrystals (NCs) with size and shape dependent properties are a thriving research field. Remarkable progress has been made in the controlled synthesis of NCs of stable elements in the past two decades; however, the knowledge of the NCs of actinide compounds has been considerably limited due the difficulties in handling them both experimentally and theoretically. Actinide compounds, especially actinide oxides, play a critical role in many stages of the nuclear fuel cycle. Recently, a non-aqueous surfactant assisted approach has been developed for the synthesis of actinide oxide NCs with different morphologies, but an understanding of its control factors is still missing to date. Herein we present a comprehensive study on the low index surfaces of thorium dioxide (ThO2) and their interactions with relevant surfactant ligands using density functional calculations. A systematic picture on the thermodynamic stability of ThO2 NCs of different sizes and shapes is obtained employing empirical models based on the calculated surface energies. It is found that bare ThO2 NCs prefer the octahedral shape terminated by (111) surfaces. Oleic acid displays selective adsorption on the (110) surface, leading to the shape transformation from octahedrons to nanorods. Other ligands such as acetylacetone, oleylamine, and trioctylphosphine oxide do not modify the equilibrium shape of ThO2 NCs. This work provides atomic level insights into the anisotropic growth of ThO2 NCs that was recently observed in experiments, and thus may contribute to the controlled synthesis of actinide oxide NCs with well-defined size and shape for future applications.

Taurus Hill Observatory Scientific Observations for Pulkova Observatory during the 2016-2017 Season

Science.gov (United States)

Hentunen, V.-P.; Haukka, H.; Heikkinen, E.; Salmi, T.; Juutilainen, J.

2017-09-01

Taurus Hill Observatory (THO), observatory code A95, is an amateur observatory located in Varkaus, Finland. The observatory is maintained by the local astronomical association Warkauden Kassiopeia. THO research team has observed and measured various stellar objects and phenomena. Observatory has mainly focused on exoplanet light curve measurements, observing the gamma rays burst, supernova discoveries and monitoring. We also do long term monitoring projects.

Doped Boron Carbide-Based Polymers: Fundamental Studies of a Novel Class of Materials for Enhanced Neutron Detection

Science.gov (United States)

2016-03-01

heterojunction diodes fabricated from these films show no evidence of Schottky barrier formation or of significant leakage current in reverse bias [8...all of summer 2012 for this purpose. Related project work: measuring the electronic structure and the surface oxide of thorium oxide ThO2 with Tony...Detecting and Nanoelectronic Applications, Techon 2012. 4. “The History and Development of Boron Carbon Alloy Devices and Rare Earth Heterojunction

Depression, anxiety, and suicidal ideation among Vietnamese secondary school students and proposed solutions: A cross-sectional study

OpenAIRE

Nguyen, Dat Tan; Dedding, Christine; Pham, Tam Thi; Wright, Pamela; Bunders-Aelen, J.G.F.

2013-01-01

Background: There is a rapidly growing public awareness of mental health problems among Vietnamese secondary school students. This study aims to determine the prevalence of anxiety, depression, and suicidal ideation, to identify related risk factors, and to explore students' own proposals for improving their mental health. Methods. A cross-sectional study was conducted among 1161 secondary students in Can Tho City, Vietnam during September through December, 2011. A structured questionnaire wa...

Are dishonest extraverts more harmful than dishonest introverts? The interaction effects of honesty-humility and extraversion in predicting workplace deviance

OpenAIRE

Oh, I.S.; Lee, K.; Ashton, M.C.; de Vries, R.E.

2011-01-01

Honesty-Humility, one of the six major personality dimensions included in the HEXACO model of personality structure, has previously been found to show negative correlations with workplace deviance. In this study, we hypothesised that Extraversion would moderate the relationship between Honesty-Humility and workplace deviance. In particular, we posited that the relation between Honesty-Humility and workplace deviance would be stronger among employees who are high on Extraversion than among tho...

Core Designs and Economic Analyses of Homogeneous Thoria-Urania Fuel in Light Water Reactors

International Nuclear Information System (INIS)

Saglam, Mehmet; Sapyta, Joe J.; Spetz, Stewart W.; Hassler, Lawrence A.

2004-01-01

The objective is to develop equilibrium fuel cycle designs for a typical pressurized water reactor (PWR) loaded with homogeneously mixed uranium-thorium dioxide (ThO 2 -UO 2 ) fuel and compare those designs with more conventional UO 2 designs.The fuel cycle analyses indicate that ThO 2 -UO 2 fuel cycles are technically feasible in modern PWRs. Both power peaking and soluble boron concentrations tend to be lower than in conventional UO 2 fuel cycles, and the burnable poison requirements are less.However, the additional costs associated with the use of homogeneous ThO 2 -UO 2 fuel in a PWR are significant, and extrapolation of the results gives no indication that further increases in burnup will make thoria-urania fuel economically competitive with the current UO 2 fuel used in light water reactors

Computed tomography of temporal bone fractures and temporal region anatomy in horses.

Science.gov (United States)

Pownder, S; Scrivani, P V; Bezuidenhout, A; Divers, T J; Ducharme, N G

2010-01-01

In people, specific classifications of temporal bone fractures are associated with clinical signs and prognosis. In horses, similar classifications have not been evaluated and might be useful establishing prognosis or understanding pathogenesis of certain types of trauma. We hypothesized associations between temporal bone fracture location and orientation in horses detected during computed tomography (CT) and frequency of facial nerve (CN7) deficit, vestibulocochlear nerve (CN8) deficit, or temporohyoid osteoarthropathy (THO). Complex temporal region anatomy may confound fracture identification, and consequently a description of normal anatomy was included. All horses undergoing temporal region CT at our hospital between July 1998 and May 2008. Data were collected retrospectively, examiners were blinded, and relationships were investigated among temporal bone fractures, ipsilateral THO, ipsilateral CN7, or ipsilateral CN8 deficits by Chi-square or Fischer's exact tests. Seventy-nine horses had CT examinations of the temporal region (158 temporal bones). Sixteen temporal bone fractures were detected in 14 horses. Cranial nerve deficits were seen with fractures in all parts of the temporal bone (petrosal, squamous, and temporal) and, temporal bone fractures were associated with CN7 and CN8 deficits and THO. No investigated fracture classification scheme, however, was associated with specific cranial nerve deficits. Without knowledge of the regional anatomy, normal structures may be mistaken for a temporal bone fracture or vice versa. Although no fracture classification scheme was associated with the assessed clinical signs, simple descriptive terminology (location and orientation) is recommended for reporting and facilitating future comparisons.

A pragmatic, multicentre, randomised controlled trial comparing stapled haemorrhoidopexy to traditional excisional surgery for haemorrhoidal disease (eTHoS): study protocol for a randomised controlled trial.

Science.gov (United States)

Watson, Angus J M; Bruhn, Hanne; MacLeod, Kathleen; McDonald, Alison; McPherson, Gladys; Kilonzo, Mary; Norrie, John; Loudon, Malcolm A; McCormack, Kirsty; Buckley, Brian; Brown, Steven; Curran, Finlay; Jayne, David; Rajagopal, Ramesh; Cook, Jonathan A

2014-11-11

Current interventions for haemorrhoidal disease include traditional haemorrhoidectomy (TH) and stapled haemorrhoidopexy (SH) surgery. However, uncertainty remains as to how they compare from a clinical, quality of life (QoL) and economic perspective. The study is therefore designed to determine whether SH is more effective and more cost-effective, compared with TH. eTHoS (either Traditional Haemorrhoidectomy or Stapled Haemorrhoidopexy for Haemorrhoidal Disease) is a pragmatic, multicentre, randomised controlled trial. Currently, 29 secondary care centres are open to recruitment. Patients, aged 18 year or older, with circumferential haemorrhoids grade II to IV, are eligible to take part. The primary clinical and economic outcomes are QoL profile (area under the curve derived from the EuroQol Group's 5 Dimension Health Status Questionnaire (EQ-5D) at all assessment points) and incremental cost per quality adjusted life year (QALY) based on the responses to the EQ-5D at 24 months. The secondary outcomes include a comparison of the SF-36 scores, pain and symptoms sub-domains, disease recurrence, complication rates and direct and indirect costs to the National Health Service (NHS). A sample size of n =338 per group has been calculated to provide 90% power to detect a difference in the mean area under the curve (AUC) of 0.25 standard deviations derived from EQ-5D score measurements, with a two-sided significance level of 5%. Allowing for non-response, 400 participants will be randomised per group. Randomisation will utilise a minimisation algorithm that incorporates centre, grade of haemorrhoidal disease, baseline EQ-5D score and gender. Blinding of participants and outcome assessors is not attempted. This is one of the largest trials of its kind. In the United Kingdom alone, 29,000 operations for haemorrhoidal disease are done annually. The trial is therefore designed to give robust evidence on which clinicians and health service managers can base management decisions

The Thoc1 encoded ribonucleoprotein is required for myeloid progenitor cell homeostasis in the adult mouse.

Science.gov (United States)

Pitzonka, Laura; Ullas, Sumana; Chinnam, Meenalakshmi; Povinelli, Benjamin J; Fisher, Daniel T; Golding, Michelle; Appenheimer, Michelle M; Nemeth, Michael J; Evans, Sharon; Goodrich, David W

2014-01-01

Co-transcriptionally assembled ribonucleoprotein (RNP) complexes are critical for RNA processing and nuclear export. RNPs have been hypothesized to contribute to the regulation of coordinated gene expression, and defects in RNP biogenesis contribute to genome instability and disease. Despite the large number of RNPs and the importance of the molecular processes they mediate, the requirements for individual RNP complexes in mammalian development and tissue homeostasis are not well characterized. THO is an evolutionarily conserved, nuclear RNP complex that physically links nascent transcripts with the nuclear export apparatus. THO is essential for early mouse embryonic development, limiting characterization of the requirements for THO in adult tissues. To address this shortcoming, a mouse strain has been generated allowing inducible deletion of the Thoc1 gene which encodes an essential protein subunit of THO. Bone marrow reconstitution was used to generate mice in which Thoc1 deletion could be induced specifically in the hematopoietic system. We find that granulocyte macrophage progenitors have a cell autonomous requirement for Thoc1 to maintain cell growth and viability. Lymphoid lineages are not detectably affected by Thoc1 loss under the homeostatic conditions tested. Myeloid lineages may be more sensitive to Thoc1 loss due to their relatively high rate of proliferation and turnover.

The Thoc1 encoded ribonucleoprotein is required for myeloid progenitor cell homeostasis in the adult mouse.

Directory of Open Access Journals (Sweden)

Laura Pitzonka

Full Text Available Co-transcriptionally assembled ribonucleoprotein (RNP complexes are critical for RNA processing and nuclear export. RNPs have been hypothesized to contribute to the regulation of coordinated gene expression, and defects in RNP biogenesis contribute to genome instability and disease. Despite the large number of RNPs and the importance of the molecular processes they mediate, the requirements for individual RNP complexes in mammalian development and tissue homeostasis are not well characterized. THO is an evolutionarily conserved, nuclear RNP complex that physically links nascent transcripts with the nuclear export apparatus. THO is essential for early mouse embryonic development, limiting characterization of the requirements for THO in adult tissues. To address this shortcoming, a mouse strain has been generated allowing inducible deletion of the Thoc1 gene which encodes an essential protein subunit of THO. Bone marrow reconstitution was used to generate mice in which Thoc1 deletion could be induced specifically in the hematopoietic system. We find that granulocyte macrophage progenitors have a cell autonomous requirement for Thoc1 to maintain cell growth and viability. Lymphoid lineages are not detectably affected by Thoc1 loss under the homeostatic conditions tested. Myeloid lineages may be more sensitive to Thoc1 loss due to their relatively high rate of proliferation and turnover.

Tritium metabolism in cow's milk after administration of tritiated water and of organically bound tritium

International Nuclear Information System (INIS)

Hoek, J. van den

1982-01-01

Tritium was administered as THO and as organically bound tritium (OBT) to lactating cows. Urine and milk samples were collected and analyzed for tritium content. Plateau levels in milk water and in milk fat, lactose and casein were reached in about 20 days after feeding either THO or OBT. Comparison of the specific activity (pCi 3 H/g H) of the various milk constituents with the specific activity of the body water showed that, after administration of THO, the highest tritium incorporation occurred in lactose (0.58), followed by milk fat (0.36) and casein (0.27). Tritium incorporation in milk dry matter (0.45) is considerably higher than in most tissue components of several mammalian species after continuous ingestion of THO as reported in the literature. After feeding OBT, the highest tritium incorporation occurred in milk fat and to a lesser extent in casein. Tritium levels in lactose were surprisingly low and the reason for this is not clear. They were similar to those in milk water. Tritium levels in milk and urine water showed systematic differences during administration of OBT and after this was stopped. There was more tritium in milk water until the last day of OBT feeding and this situation was reversed after this. (author)

Tritium metabolism in cow's milk after administration of tritiated water and of organically bound tritium

Energy Technology Data Exchange (ETDEWEB)

van den Hoek, J [Landbouwhogeschool Wageningen (Netherlands). Lab. voor Fysiologie der Dieren; Gerber, G; Kirchmann, R [Centre d' Etude de l' Energie Nucleaire, Mol (Belgium)

1982-01-01

Tritium was administered as THO and as organically bound tritium (OBT) to lactating cows. Urine and milk samples were collected and analyzed for tritium content. Plateau levels in milk water and in milk fat, lactose and casein were reached in about 20 days after feeding either THO or OBT. Comparison of the specific activity (pCi/sup 3/H/g H) of the various milk constituents with the specific activity of the body water showed that, after administration of THO, the highest tritium incorporation occurred in lactose (0.58), followed by milk fat (0.36) and casein (0.27). Tritium incorporation in milk dry matter (0.45) is considerably higher than in most tissue components of several mammalian species after continuous ingestion of THO as reported in the literature. After feeding OBT, the highest tritium incorporation occurred in milk fat and to a lesser extent in casein. Tritium levels in lactose were surprisingly low and the reason for this is not clear. They were similar to those in milk water. Tritium levels in milk and urine water showed systematic differences during administration of OBT and after this was stopped. There was more tritium in milk water until the last day of OBT feeding and this situation was reversed after this.

Fabrication of 0.5-inch diameter FBR mixed oxide fuel pellets

International Nuclear Information System (INIS)

Rasmussen, D.E.; Benecke, M.W.; McCord, R.B.

1979-01-01

Large diameter (0.535 inch) mixed oxide fuel pellets for Fast Breeder Reactor application were successfully fabricated by the cold-press-and-sinter technique. Enriched UO 2 , PuO 2 -UO 2 , and PuO 2 -ThO 2 compositions were fabricated into nominally 90% theoretical density pellets for the UO 2 and PuO 2 -UO 2 compositions, and 88% and 93% T.D. for the PuO 2 -ThO 2 compositions. Some processing adjustments were required to achieve satisfactory pellet quality and density. Furnace heating rate was reduced from 200 to 50 0 C/h for the organic binder burnout cycle for the large, 0.535-inch diameter pellets to eliminate pellet cracking during sintering. Additional preslugging steps and die wall lubrication during pressing were used to eliminate pressing cracks in the PuO 2 -ThO 2 pellets

Postirradiation examination of capsules GF-1, GF-2, and GF-3

International Nuclear Information System (INIS)

Kovacs, W.J.; Blanchard, R.; Pointud, M.L.

1980-09-01

The GF-1, GF-2, and GF-3 capsule tests were irradiated in the Siloe reactor at Grenoble, France, between October 31, 1973, and July 25, 1975. High-enriched uranium (HEU) mixed oxide (8Th,U)O 2 fissile and ThO 2 fertile particles were tested over the following exposure conditions: 3.8 to 11.0 x 10 25 n/m 2 (E > 29 fJ)/sub HTGR/; 960 0 to 1120 0 C time volume average temperature; and mixed oxide (8Th,U)O 2 burnup between 5.3 and 11.4% FIMA and ThO 2 burnup between 1.1 and 3.6% FIMA. Postirradiation examination of HTGR fuel rods in capsules GF-1, GF-2, and GF-3 showed acceptable structural integrity and irradiation-induced dimensional changes that were consistent with model predictions. Pressure vessel failure levels between different TRISO-coated (8Th,U)O 2 fissile particle types showed that the 400-μm-diameter kernel design was more conservative than the 500-μm-diameter designs

X-Ray Fluorescence Spectrometry. I. Determination of thorium in ores

International Nuclear Information System (INIS)

Bermudez Polonio, J.; Crus Castillo, F. de la; Fernandez Cellini, R.

1961-01-01

A X-ray spectrometric method has been developed for analysis of thorium in ores in the range of concentration from 0.01 to 0.5 percent ThO 2 , using selenium as a internal standard. The concentration of thorium is determined in a working curve prepared by plotting the percentage of ThO 2 against the ratio intensity of the Th Lα 1 line to Sek β 1 line. (Author) 17 refs

Speciation of uranium in UxTh1-xO2 by time resolved emission spectroscopy

International Nuclear Information System (INIS)

Pathak, N.; Gupta, Santosh K.; Thulasidas, S.K.; Natarajan, V.

2014-01-01

The utilization of thorium based fuel leads to stable energy supply, higher resistance to nuclear proliferation and lesser long lived minor actinides in the spent fuel. Enriched uranium or plutonium added thorium oxide (ThO 2 ) has been considered as a nuclear fuel for various reactors such as light water reactors, heavy water reactors, high-temperature gas-cooled reactors and accelerator-driven systems. Moreover, ThO 2 is a matrix candidate for plutonium incineration

Crystal and molecular structures of thorium and uranium tetrakis(hexafluoroacetonylpyrazolide) complexes

International Nuclear Information System (INIS)

Volz, K.; Zalkin, A.; Templeton, D.H.

1976-01-01

Triclinic crystals of thorium(IV) and uranium(IV) tetrakis(hexafluoroacetonylpyrazolide) are isostructural, with space group P1 and Z = 2. At 23 0 C for Th(C 6 H 3 ON 2 F 6 ) 4 α = 11.282 (5) A, b = 16.245 (7) A, c = 10.836 (5) A, α = 90.14 (5) 0 , β = 108.75 (5) 0 , and γ = 107.07 (5) 0 . For the uranium compound a = 11.302 (5) A, b = 16.377 (8) A, c = 11.000 (5) A, α = 87.85 (5) 0 , β = 111.02 (5) 0 , and γ = 109.95 (5) 0 . X-ray diffraction data were measured with a scintillation counter, theta-2theta scans, and Mo Kα radiation. For thorium the conventional R value is 0.026 for 2966 unique data with I greater than sigma(I), and for uranium it is 0.027 for 4125 unique data with I greater than sigma(I). The full-matrix least-squares refinement of the 598 parameters of each structure included anisotropic thermal parameters for the 61 nonhydrogen atoms and isotropic ones for the 12 hydrogen atoms. The actinide ion is at the center of an irregular polyhedron of four oxygen and four nitrogen atoms. The average Th-O, Th-N, U-O, and U-N distances are 2.291 (4), 2.637 (5), 2.237 (3), and 2.574 (5) A. The molecules are packed in a manner which resembles cubic closest packing but which is more nearly analogous to the body-centered tetragonal structure of protactinium metal

Estimate of the absorbed dose in the mouse organs and tissues after tritium administration

International Nuclear Information System (INIS)

Saito, Masahiro

2000-01-01

Chronic and accidental release of tritium from future fusion facilities may cause some extent of hazardous effect to the public health. Various experiments using small animals such as mice have been performed to mimic the dose accumulation due to tritium intake by the human body. An difficulty in such animal experiments using small animals is that it is rather difficult to administer tritium orally and estimate the dose to small organs or tissues. In the course of our study, a simple method to administer THO and T-labeled amino acids orally to the mouse was dictated and dose accumulation in various organs and tissues was determined. The tritium retention in the bone marrow was also determined using the micro-centrifuge method. Throughout our experiment, colony-bred DDY mice were used. The 8-10 week old male mice were orally and intraperitoneally administered THO water or T-amino acids mixture solution. For the purpose of oral administration, a 10 μl aliquot of T-containing saline solution was placed on the tongue of the mice using an automatic micropipette. At various times after tritium administration, the animals were sacrificed and the amount of tritium in various tissues and organs including bone marrow was examined. Dose accumulation pattern after THO intake and T-amino acids was compared between intraperitoneal injection and oral administration. The accumulated dose after oral administration of THO exhibited a tendency to be 10-20% higher than after intraperitoneal injection. The bone marrow dose after oral intake of THO was found to be lower than the doses to urine, blood, liver and testis. In contrast, the blood dose gave a conservative estimate for the dose to the other tissues and organs. (author)

A new immersion sensor for rapid electrochemical determination of dissolved oxygen in liquid metals

International Nuclear Information System (INIS)

Janke, D.; Schwerdtfeger, K.

1978-01-01

Development of a new solid electrolyte 'needle sensor' with ZrO 2 or ThO 2 electrolyte and metal-metal oxide reference mixture for the rapid determination of oxygen in steel melts. Details of the manufacture of the layer-structured, miniaturized probe. Test results of simultaneous measurements performed with the newly developed ZrO 2 needle sensor and the hitherto usual tubular sensor in iron melts at oxygen activities between 0.00005 and 0.030. (orig.) [de

Alpha spectrometry and the secondary ion mass spectrometry of thorium

International Nuclear Information System (INIS)

Strisovska, J.; Kuruc, J.; Galanda, D.; Matel, L.; Aranyosiova, M.; Velic, D.

2009-01-01

The main objective of this master thesis was preparation of samples with thorium content on the steel discs by electrodeposition for determination of natural thorium isotope by alpha spectrometry and the secondary ion mass spectrometry and finding out their possible linear correlation between these methods. The samples with electrolytically excluded isotope of 232 Th were prepared by electrodeposition from solution Th(NO 3 ) 4 ·12 H2 O on steel discs in electrodeposition cell with use of solutions Na 2 SO 4 , NaHSO 4 , KOH and (NH 4 ) 2 (C 2 O 4 ) by electric current 0.75 A. Discs were measured by alpha spectrometer. Activity was calculated from the registered impulses for 232 Th and surface's weight. After alpha spectrometry measurements discs were analyzed by TOF-SIMS IV which is installed in the International Laser Centre in Bratislava. Intensities of isotope of 232 Th and ions of ThO + , ThOH + , ThO 2 H + , Th 2 O 4 H + , ThO 2 - , ThO 3 H - , ThH 3 O 3 - and ThN 2 O 5 H - were identified. The linear correlation is between surface's weights of Th and intensities of ions of Th + from SIMS, however the correlation coefficient has relatively low value. We found out with SIMS method that oxidized and hydride forms of thorium are significantly represented in samples with electroplated thorium. (authors)

Hemihepatic versus total hepatic inflow occlusion during hepatectomy: a systematic review and meta-analysis.

Science.gov (United States)

Wang, Hai-Qing; Yang, Jia-Yin; Yan, Lu-Nan

2011-07-14

To evaluate the clinical outcomes of patients undergoing hepatectomy with hemihepatic vascular occlusion (HHO) compared with total hepatic inflow occlusion (THO). Randomized controlled trials (RCTs) comparing hemihepatic vascular occlusion and total hepatic inflow occlusion were included by a systematic literature search. Two authors independently assessed the trials for inclusion and extracted the data. A meta-analysis was conducted to estimate blood loss, transfusion requirement, and liver injury based on the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Either the fixed effects model or random effects model was used. Four RCTs including 338 patients met the predefined inclusion criteria. A total of 167 patients were treated with THO and 171 with HHO. Meta-analysis of AST levels on postoperative day 1 indicated higher levels in the THO group with weighted mean difference (WMD) 342.27; 95% confidence intervals (CI) 217.28-467.26; P = 0.00 001; I(2) = 16%. Meta-analysis showed no significant difference between THO group and HHO group on blood loss, transfusion requirement, mortality, morbidity, operating time, ischemic duration, hospital stay, ALT levels on postoperative day 1, 3 and 7 and AST levels on postoperative day 3 and 7. Hemihepatic vascular occlusion does not offer satisfying benefit to the patients undergoing hepatic resection. However, they have less liver injury after liver resections.

High temperature studies on scheelite and zircon type ThGeO4

International Nuclear Information System (INIS)

Patwe, S.J.; Achary, S.N.; Tyagi, A.K.

2008-01-01

The detailed structural analyses of two polymorphs of ThGeO 4 , namely, zircon (stable) and scheelite (metastable) types have been carried out from the in situ high temperature X-ray diffraction studies. Though both the polymorphs show positive thermal expansion, the coefficient of volume thermal expansion of scheelite modification is almost double of that for zircon modification. The anisotropies in thermal expansion behaviors are also different for the two modifications. The differences in thermal expansion behaviors have been explained from the differences in structural arrangements and anisotropy of the ThO 8 polyhedra in these two modifications. (author)

Thermal expansion data of (Th,U)O2 fuels

International Nuclear Information System (INIS)

Sengupta, A.K.; Banerjee, J.; Bhagat, R.K.; Ramachandran, R.; Majumdar, S.; Purushotham, D.S.C.

2000-04-01

Thermal expansion data for sintered ThO 2 and ThO 2 containing 2, 4, 6, 10 and 20% UO 2 pellets were measured using a high temperature dilatometer in the temperature range from ambient to 1773 K. The dilatometer was first calibrated using a standard graphite sample as reference material. The reproducibility of the dilatometer was tested by measuring the coefficient of expansion of tungsten (NBS SRM 737) and comparing the data with that recommended by National Bureau of Standard. It was observed that there is close agreement between the experimental and reported data. The coefficient of expansion data of (Th,U)O 2 fuel indicate that out of all the six compositions, ThO 2 +2%UO 2 showed the maximum expansion of around 1.75% at 1773 K. However, the expansion data for all the compositions were very close to each other. Empirical equation correlating thermal expansion and temperature for all six compositions have been generated and reported. (author)

Current status of VEGA program

International Nuclear Information System (INIS)

Hidaka, Akihide; Nakamura, Takehiko; Nishino, Y.; Kanazawa, H.; Hashimoto, Kazuichiro; Harada, Yuhei; Kudo, Tamotsu; Uetsuka, Hiroshi; Sugimoto, Jun

1999-01-01

The VEGA program has been performed at JAERI to investigate the release of transuranium and FP including non-volatile and short-life radionuclides from Japanese PWR/BWR irradiated fuel at ∼3000degC under high pressure condition up to 1.0 MPa. One of special features is to investigate the effect of ambient pressure on FP release which has never been examined in previous studies. As the furnace structures, ZrO 2 , W or ThO 2 will be used depending on the experimental conditions. In the post-test measurement, off-line gamma spectrometry, metallography and the elemental analyses are scheduled with SEM/EPMA, SIMA and ICP-AES. The installation of test facility into the beta/gamma concrete No.5 cell at the Reactor Fuel Examination Facility (RFEF) will be finished soon and four experiments in a year are scheduled. The analyses will be conducted with the VICTORIA code to prepare the operational conditions and to evaluate the results. Preliminary fabrication of ThO 2 crucible and tube was mostly successful by using the centrifugal slip casting technique. The FP release from MOX fuel will also be investigated in future. (author)

Study of the carbon reduction of thorium dioxide with the aid of high temperature X-ray diffractometry under controlled pressure, then under vacuum

International Nuclear Information System (INIS)

Pialoux, A.; Zaug, J.

1976-01-01

Compressed samples of various initial compositions in the range ThO 2 +nC(0 0 C. In this way, the lattice parameters of 'ThO 2 ' (fcc), 'ThC 2 ' (monoclinic, tetragonal and cubic forms) and 'ThC' (fcc) were measured and the compositions of these nonstoichiometric phases which coexist at high temperatures evaluated. Most of the thorium carbides observed contained, by all appearance, very little oxygen, and from this it was possible to refine some of the phase boundaries in the Th-C system previously established by some investigators. (Auth.)

The Formation of Laurentia: Evidence from Shear Wave Splitting and Seismic Tomography

Science.gov (United States)

Liddell, M. V.; Bastow, I. D.; Rawlinson, N.; Darbyshire, F. A.; Gilligan, A.

2017-12-01

The northern Hudson Bay region of Canada comprises several Archean cratonic nuclei, assembled by Paleoproterozoic orogenies including the 1.8 Ga Trans-Hudson Orogen (THO) and Rinkian-Nagssugtoqidian Orogen (NO). Questions remain about how similar in scale and nature these orogens were compared to modern orogens like the Himalayas. Also in question is whether the thick Laurentian cratonic root below Hudson Bay is stratified, with a seismically-fast Archean core underlain by a lower, younger, thermal layer. We investigate these problems via shear-wave splitting and teleseismic tomography using up to 25 years of data from 65 broadband seismic stations across northern Hudson Bay. The results of the complementary studies comprise the most comprehensive study to date of mantle seismic velocity and anisotropy in northern Laurentia. Splitting parameter patterns are used to interpret multiple layers, lithospheric boundaries, dipping anisotropy, and deformation zone limits for the THO and NO. Source-side waveguide effects from Japan and the Aleutian trench are observed despite the tomographic data being exclusively relative arrival time. Mitigating steps to ensure data quality are explained and enforced. In the Hudson Strait, anisotropic fast directions (φ) generally parallel the THO, which appears in tomographic images as a strong low velocity feature relative to the neighbouring Archean cratons. Several islands in northern Hudson Bay show short length-scale changes in φ coincident with strong velocity contrasts. These are interpreted as distinct lithospheric blocks with unique deformational histories, and point to a complex, rather than simple 2-plate, collisional history for the THO. Strong evidence is presented for multiple anisotropic layers beneath Archean zones, consistent with the episodic development model of cratonic keels (e.g., Yuan & Romanowicz 2010). We show via both tomographic inversion models and SKS splitting patterns that southern Baffin Island was

Study on the effect of UO2 composition on dissolution of sintered (Th-U)O2 MOX by microwave heating

International Nuclear Information System (INIS)

Singh, G.; Malav, R.K.; Fulzele, A.K.; Prakash, A.; Afzal, Md.; Panakkal, J.P.

2010-01-01

Full text: Complete dissolution of sample is a prerequisite for any chemical analysis in liquid form. Dissolution of ThO 2 based mixed oxide sample like (Th-U)O 2 , (Th-Pu)O 2 is a challenging job due to single oxidation state of thorium (IV). The present paper describes a study carried out on effect of UO 2 composition on dissolution of sintered (Th-U)O 2 mixed oxide pellets, in 0.05M HF prepared in 16 M HNO 3 . The experiments were performed in PTFE pressure vessels which could stand up to ∼ 250 deg C and safely operated up to 120 psi in an indigenous 700 watts microwave digestion system. ThO 2 , ThO 2 -3.75%UO 2 and ThO 2 -5%UO 2 pellets (∼ 6 g each) were dissolved in 60 mL of 16M HNO 3 /HF mixtures (0.05M HF in 16 M HNO 3 ) in PTFE (teflon) made pressure vessels (each experiment triplicate) at a pressure of ∼ 120 psi. Samples (two at an instant) were withdrawn after each hour and Th in the solution was determined by EDTA complexometric titration where end point was detected visually. Table 1 shows the results of percent dissolution of Th (mean of three experiments) for the sintered pellet after each interval of time until 100% dissolution. The plot for percent dissolution of Th (mean Th %) against time taken for sintered pellets is shown. Application of microwave heating has been applied for the dissolution of uncrushed sintered ThO 2 and (Th-U)O 2 pellets. It is quite evident from Th% dissolved versus time curves that the dissolution is faster as percentage of UO 2 in (Th-U)O 2 MOX solid solution increases. This is attributed to UO 2 as it can easily absorb microwave energy, leading to high temperature

Effect of oxide additives on radiolytic decomposition of zirconium and thorium nitrates

International Nuclear Information System (INIS)

Joshi, N.G.; Garg, A.N.; Natarajan, V.; Sastry, M.D.

1996-01-01

Gamma ray-induced decomposition of the binary mixtures of zirconium and thorium nitrates with 2.5, 5 and 10 mol% of V 2 O 5 , PbO, ThO 2 , ZrO 2 , and MnO 2 has been studied at different doses up to 260 kGy. Radiation chemical yield G(NO 2 - )-values are enhanced by V 2 O 5 , PbO, and ThO 2 but are decreased by ZrO 2 and MnO 2 . The effect of radiation dose on the G(NO 2 - ) values of the binary mixtures of zirconium nitrate with 10 mol% of As 2 O 3 , CuO, MgO, MoO 3 , PbO, ZnO, V 2 O 5 , ThO 2 , MnO 2 and ZrO 2 has been studied. ESR and TL measurements suggest the formation of radical species which interact with the damage entities to enhance or retard the decomposition of the nitrates. A possible mechanism based on the interaction of radical species has been suggested. (Author)

Prevalence of cervical human papilloma virus infection among married women in Vietnam, 2011.

Science.gov (United States)

Vu, Lan T H; Bui, Dieu

2012-01-01

The burden of cervical cancer is increasing in Vietnam in the recent years, infection with high risk HPV being the cause. This study aimed to examine the prevalence of HPV and the distribution of HPV specific types among the general population in 5 big cities in Vietnam. Totals of 1500 women in round 1 and 3000 in round 2 were interviewed and underwent gynecological examination. HPV infection status, and HPV genotyping test were performed for all participants. Results indicated that the prevalence of HPV infection in 5 cities ranged from 6.1% to 10.2% with Can Tho having highest prevalence. The most common HPV types in all 5 cities were HPV 16, 18 and 58. Most of the positive cases were infected with high risk HPV, especially in Hanoi and Can Tho where more than 90% positive cases were high risk HPV. Furthermore, in Can Tho more than 60% of women were infected with multiple HPV types. The information from this study can be used to provide updated data for planning preventive activities for cervical cancer in the studied cities.

Safety analysis of thorium-based fuels in the General Electric Standard BWR

International Nuclear Information System (INIS)

Colby, M.J.; Townsend, D.B.; Kunz, C.L.

1980-06-01

A denatured (U-233/Th)O 2 fuel assembly has been designed which is energy equivalent to and hardware interchangeable with a modern boiling water reactor (BWR) reference reload assembly. Relative to the reference UO 2 fuel, the thorium fuel design shows better performance during normal and transient reactor operation for the BWR/6 product line and will meet or exceed current safety and licensing criteria. Power distributions are flattened and thermal operating margins are increased by reduced steam void reactivity coefficients caused by U-233. However, a (U-233/Th)O 2 -fueled BWR will likely have reduced operating flexibility. A (U-235/Th)O 2 -fueled BWR should perform similar to a UO 2 -fueled BWR under all operating conditions. A (Pu/Th)O 2 -fueled BWR may have reduced thermal margins and similar accident response and be less stable than a UO 2 -fueled BWR. The assessment is based on comparisions of point model and infinite lattice predictions of various nuclear reactivity parameters, including void reactivity coefficients, Doppler reactivity coefficients, and control blade worths

Oxygen potential of Th1-yUyO2+x

International Nuclear Information System (INIS)

Schram, R.P.C.; Cordfunke, E.H.P.

1996-03-01

Oxygen potentials of UO 2 -ThO 2 solid solutions (Th 1-y U y O 2+x ) were retrieved from literature and stored in a database. For each datapoint the oxygen pressure p O 2 the nonstoichiometry x, the temperature T and the uranium concentration y was specified. The data were analyzed using a defect model, which includes electronic disorder, point defects and cluster formation. In addition, the thermochemical representation of Lindemer and Besmann for UO 2+x was extended for the analysis of the Th 1-y U y O 2+x data. The solid solution is regarded as an ideal ternary mixture of UO 2 , ThO 2 and a hypothetical compound U a O b . The thermodynamic properties of this compound U a O b were determined in two oxygen pressure ranges of the database. In both the defect model and thermochemical approach ThO 2 is treated as an inert compound that does not participate in any of the chemical equilibria describing the oxygen potential. (orig.)

Differential expression of THOC1 and ALY mRNP biogenesis/export factors in human cancers

International Nuclear Information System (INIS)

Domínguez-Sánchez, María S; Sáez, Carmen; Japón, Miguel A; Aguilera, Andrés; Luna, Rosa

2011-01-01

One key step in gene expression is the biogenesis of mRNA ribonucleoparticle complexes (mRNPs). Formation of the mRNP requires the participation of a number of conserved factors such as the THO complex. THO interacts physically and functionally with the Sub2/UAP56 RNA-dependent ATPase, and the Yra1/REF1/ALY RNA-binding protein linking transcription, mRNA export and genome integrity. Given the link between genome instability and cancer, we have performed a comparative analysis of the expression patterns of THOC1, a THO complex subunit, and ALY in tumor samples. The mRNA levels were measured by quantitative real-time PCR and hybridization of a tumor tissue cDNA array; and the protein levels and distribution by immunostaining of a custom tissue array containing a set of paraffin-embedded samples of different tumor and normal tissues followed by statistical analysis. We show that the expression of two mRNP factors, THOC1 and ALY are altered in several tumor tissues. THOC1 mRNA and protein levels are up-regulated in ovarian and lung tumors and down-regulated in those of testis and skin, whereas ALY is altered in a wide variety of tumors. In contrast to THOC1, ALY protein is highly detected in normal proliferative cells, but poorly in high-grade cancers. These results suggest a differential connection between tumorogenesis and the expression levels of human THO and ALY. This study opens the possibility of defining mRNP biogenesis factors as putative players in cell proliferation that could contribute to tumor development

Brainstem auditory evoked responses in an equine patient population: part I--adult horses.

Science.gov (United States)

Aleman, M; Holliday, T A; Nieto, J E; Williams, D C

2014-01-01

Brainstem auditory evoked response has been an underused diagnostic modality in horses as evidenced by few reports on the subject. To describe BAER findings, common clinical signs, and causes of hearing loss in adult horses. Study group, 76 horses; control group, 8 horses. Retrospective. BAER records from the Clinical Neurophysiology Laboratory were reviewed from the years of 1982 to 2013. Peak latencies, amplitudes, and interpeak intervals were measured when visible. Horses were grouped under disease categories. Descriptive statistics and a posthoc Bonferroni test were performed. Fifty-seven of 76 horses had BAER deficits. There was no breed or sex predisposition, with the exception of American Paint horses diagnosed with congenital sensorineural deafness. Eighty-six percent (n = 49/57) of the horses were younger than 16 years of age. The most common causes of BAER abnormalities were temporohyoid osteoarthropathy (THO, n = 20/20; abnormalities/total), congenital sensorineural deafness in Paint horses (17/17), multifocal brain disease (13/16), and otitis media/interna (4/4). Auditory loss was bilateral and unilateral in 74% (n = 42/57) and 26% (n = 15/57) of the horses, respectively. The most common causes of bilateral auditory loss were sensorineural deafness, THO, and multifocal brain disease whereas THO and otitis were the most common causes of unilateral deficits. Auditory deficits should be investigated in horses with altered behavior, THO, multifocal brain disease, otitis, and in horses with certain coat and eye color patterns. BAER testing is an objective and noninvasive diagnostic modality to assess auditory function in horses. Copyright © 2014 by the American College of Veterinary Internal Medicine.

Endothelial extraction of tracer water varies with extravascular water in dog lungs

International Nuclear Information System (INIS)

Chinard, F.P.; Cua, W.O.

1987-01-01

In multiple indicator-dilution experiments, transvascular passage of a permeating indicator is conventionally derived from the up-slope separation of the curve of the permeating indicator from that of a vascular reference and is expressed as the extraction (Ec). Extraction may be limited by the barrier (barrier-limited distribution). It may be limited by the volume of distribution accessible to it; in the time domain of an indicator-dilution experiment, the passage to and distribution in the extravascular volume are rapid relative to the velocity of blood in the exchange vessels. We examine here the relations of the extraction of tracer water as tritium oxide (THO) [Ec(THO)] and of the extraction of tracer sodium as 22Na [Ec(22Na)] to extravascular lung water, delta V wev, by adding isotonic fluid to the gas phase of the lungs. The net convective transvascular passage of water is negligible relative to the transendothelial molecular exchange. In 10 experiments in vivo and in 10 experiments in isolated perfused lungs, Ec(THO) increases as delta V wev increases. Ec(22Na) and the permeability-surface area product (PS) for 22Na do not change as delta V wev increases. We conclude that the extraction of THO is determined mainly by the volume accessible to it (flow- or volume-limited distribution) and that the extraction of 22Na is determined mainly by the resistance of the endothelium (barrier-limited distribution). A diffusion limitation in the added alveolar fluid rather than a barrier limitation at the endothelium may moderate Ec

Sleep Apnea Detection Based on Thoracic and Abdominal Movement Signals of Wearable Piezo-Electric Bands.

Science.gov (United States)

Lin, Yin-Yan; Wu, Hau-Tieng; Hsu, Chi-An; Huang, Po-Chiun; Huang, Yuan-Hao; Lo, Yu-Lun

2016-12-07

Physiologically, the thoracic (THO) and abdominal (ABD) movement signals, captured using wearable piezo-electric bands, provide information about various types of apnea, including central sleep apnea (CSA) and obstructive sleep apnea (OSA). However, the use of piezo-electric wearables in detecting sleep apnea events has been seldom explored in the literature. This study explored the possibility of identifying sleep apnea events, including OSA and CSA, by solely analyzing one or both the THO and ABD signals. An adaptive non-harmonic model was introduced to model the THO and ABD signals, which allows us to design features for sleep apnea events. To confirm the suitability of the extracted features, a support vector machine was applied to classify three categories - normal and hypopnea, OSA, and CSA. According to a database of 34 subjects, the overall classification accuracies were on average 75.9%±11.7% and 73.8%±4.4%, respectively, based on the cross validation. When the features determined from the THO and ABD signals were combined, the overall classification accuracy became 81.8%±9.4%. These features were applied for designing a state machine for online apnea event detection. Two event-byevent accuracy indices, S and I, were proposed for evaluating the performance of the state machine. For the same database, the S index was 84.01%±9.06%, and the I index was 77.21%±19.01%. The results indicate the considerable potential of applying the proposed algorithm to clinical examinations for both screening and homecare purposes.

Polymeric media for tritium fixation. Supplement I

International Nuclear Information System (INIS)

Franz, J.A.; Burger, L.L.

1976-01-01

Procedures for the fixation of tritium as TH or THO in two different polymeric media are described. The complete procedure for THO fixation in a polyureylene-polyurethane polumer, including polymer molding procedures and leach tests is presented. The catalytic tritiation of polystyrene under very mild conditions using a rhodium catalyst is also described. Thermal stabilities and cost estimates for the polymers examined under this program are discussed. Organic polymers were found to have attractive features for the fixation and storage of concentrated tritium wastes due to the convenience of fixation procedures and favorable properties of the resulting media

Order of Magnitude Smaller Limit on the Electron's Electron Dipole Moment

Science.gov (United States)

Gabrielse, Gerald

2014-05-01

Proposed extensions to the Standard Model of particle physics typically predict that the electron would naturally have a small but potentially measurable electric dipole moment (EDM). The Standard Model, known to be incomplete, instead predicts that the electron EDM is much too small to measure. The ACME collaboration used the enormous electric field that electrons experience within a ThO molecule, the unique structure of this molecule, and a cryogenic buffer gas beam of molecules to search for an electron EDM. The new search was sensitive enough to detect an EDM that is ten times smaller than the previously measured upper limit - well within the range of predictions from various proposed extensions to the Standard Model. We did not detect such an EDM, however. Instead, we set a new upper limit on the electron EDM at a 90% confidence limit, | de | < 8 . 7 × 10-29 , making use of the effective electric field calculated for ThO. The new limit stringently constrains the parameters of proposed extensions to the Standard Model to values that predict an electron EDM smaller than the new limit. The TeV energy scale being probed is comparable to that being investigated at CERN's Large Hadron Collider (LHC). Supported by the AMO program of the NSF.

High-temperature vaporization behavior of oxygen-deficient thoria

International Nuclear Information System (INIS)

Ackermann, R.J.; Tetenbaum, M.

1979-01-01

The experimental results of the present study on the vaporization behavior of oxygen-deficient thoria are directed toward a more precise and detailed study of the lower phase boundary (l.p.b.) and congruently vaporizing composition (c.v.c), and intermediate compositions, and the corresponding oxygen potentials and total pressure at temperatures above 2000K. The l.p.b. and c.v.c. values were found to fit an equation of the form log x = A + (B/T), where x is the stoichiometric defect in ThO 2 -x. Oxygen potentials corresponding to the l.p.b. and c.v.c. have been estimated from vapor pressures and thermodynamic data. A very sharp decrease in oxygen potential occurs when thoria isreduced only slightly from the stoichiometric composition. In the temperature range from 2400 to 2655 K, the oxygen partial pressure dependency of x in ThO 2 -x was found to be approximately proportional to PO 2 - 1 /4to PO 2 - 1 /. The small extent of reduction over a wide range of oxygen potentials at these temperatures is a clear illustration of the higher stability of the ThO 2 -x phase compared with that of UO 2 -x. Values of ΔHO 2 and ΔSO 2 have been estimated for selected compositions from the dependence of the measured oxygen potential on temperature. Estimates of the standard free energy of formation of bivariant ThO 2 -x compositions have been made. A substantial increase in the total pressure of thorium-bearing species occurs when stoichiometric thoria is reduced toward the lower phase boundary. (orig.) [de

Safety and Regulatory Issues of the Thorium Fuel Cycle

Energy Technology Data Exchange (ETDEWEB)

Ade, Brian [ORNL; Worrall, Andrew [ORNL; Powers, Jeffrey [ORNL; Bowman, Steve [ORNL; Flanagan, George [ORNL; Gehin, Jess [ORNL

2014-02-01

Thorium has been widely considered an alternative to uranium fuel because of its relatively large natural abundance and its ability to breed fissile fuel (233U) from natural thorium (232Th). Possible scenarios for using thorium in the nuclear fuel cycle include use in different nuclear reactor types (light water, high temperature gas cooled, fast spectrum sodium, molten salt, etc.), advanced accelerator-driven systems, or even fission-fusion hybrid systems. The most likely near-term application of thorium in the United States is in currently operating light water reactors (LWRs). This use is primarily based on concepts that mix thorium with uranium (UO2 + ThO2), add fertile thorium (ThO2) fuel pins to LWR fuel assemblies, or use mixed plutonium and thorium (PuO2 + ThO2) fuel assemblies. The addition of thorium to currently operating LWRs would result in a number of different phenomenological impacts on the nuclear fuel. Thorium and its irradiation products have nuclear characteristics that are different from those of uranium. In addition, ThO2, alone or mixed with UO2 fuel, leads to different chemical and physical properties of the fuel. These aspects are key to reactor safety-related issues. The primary objectives of this report are to summarize historical, current, and proposed uses of thorium in nuclear reactors; provide some important properties of thorium fuel; perform qualitative and quantitative evaluations of both in-reactor and out-of-reactor safety issues and requirements specific to a thorium-based fuel cycle for current LWR reactor designs; and identify key knowledge gaps and technical issues that need to be addressed for the licensing of thorium LWR fuel in the United States.

Summary report of phase I residual holdup measurements for a mixed oxide fuel fabrication facility

International Nuclear Information System (INIS)

Woodsum, H.C.

1978-03-01

Metal surface-powder adherence tests showed that the average mean values for direct impingement was 60 to 80 g/ft 2 , whereas the average mean values of the colloidal samples were 0.2 to 2.5 g/ft 2 . Thus, it is advantageous to design powder processing equipment to reduce direct impingement wherever possible. Holdup of powder appears to be relatively independent of the surface material or finish, and it is reduced significantly by low-frequency vibration of the surface. Under colloidal conditions, ThO 2 produces more residual material than UO 2 and is preferentially deposited from a UO 2 --ThO 2 blend. Pure ThO 2 and high enrichment blends of ThO 2 in UO 2 are expected to produce a significant, persistent electrostatic charge, thus increasing residual holdup. Residual holdup in the clean scrap recovery system (CSRS) could be reduced by 25%. Comparison of CSRS holdup and powder adherence-metal surface data indicated that the areal density of residual material (40 g/ft 2 ) was considerably higher than for colloidal suspension ( 2 ). Steady-state residual holdup factor for sintered-metal filters was 13 g/ft 2 of filter surface area under optimum conditions. During the pellet grinding tests, residual material built up in the system at rate of about 100 g/h to an estimated limit of 1.4 kg, primarily within the particle collector shroud. During dry grinding, 97% of this residue was contained within the shroud, and during wet grinding only 50% was contained in the shroud owing to inertial effects of the rotating wheel and water coolant

Compositional changes at the interface between thorium-doped uranium dioxide and zirconium due to high-temperature annealing

Science.gov (United States)

Youn, Young-Sang; Lee, Jeongmook; Kim, Jandee; Kim, Jong-Yun

2018-06-01

Compositional changes at the interface between thorium-doped uranium dioxide (U0.97Th0.03O2) and Zr before and after annealing at 1700 °C for 18 h were studied by X-ray photoelectron spectroscopy, X-ray diffraction, and Raman spectroscopy. At room temperature, the U0.97Th0.03O2 pellet consisted of hyperstoichiometric UO2+x with UO2 and ThO2, and the Zr sample contained Zr with ZrO2. After annealing, the former contained stoichiometric UO2 with ThO2 and the latter consisted of ZrO2 along with ZrO2·2H2O.

Recent activities of the nuclear fuel technology department of Cekmece Nuclear Research and Training Center

International Nuclear Information System (INIS)

Can, S.; Aybers, T.; Kopuz, B.

1997-01-01

The Nuclear Fuel Technology Department (NFTD) in CNRTC is a unique unit in Turkey in charge of performing all activities in nuclear fuel field. It has a pilot plant on uranium refining and conversion to UO 2 since 1986. Presently, its R and D activities are focused on pellet manufacturing and characterization: UO 2 , ThO 2 and (Th,U)O 2 . The studies on thorium dioxide fuel include to obtain ThO 2 pellets from thorium nitrate and mixed (Th,U)O 2 pellets. A study on evaluation of different fuel cycle options in accordance with nuclear energy planning in Turkey is also going on. (author)

Thermal expansion data

International Nuclear Information System (INIS)

Taylor, D.

1984-01-01

This paper gives regression data for a modified second order polynomial fitted to the expansion data of, and percentage expansions for dioxides with (a) the fluorite and antifluorite structure: AmO 2 , BkO 2 , CeO 2 , CmO 2 , HfO 2 , Li 2 O, NpO 2 , PrO 2 , PuO 2 , ThO 2 , UO 2 , ZrO 2 , and (b) the rutile structure: CrO 2 , GeO 2 , IrO 2 , MnO 2 , NbO 2 , PbO 2 , SiO 2 , SnO 2 , TeO 2 , TiO 2 and VO 2 . Reduced expansion curves for the dioxides showed only partial grouping into iso-electronic series for the fluorite structures and showed that the 'law of corresponding states' did not apply to the rutile structures. (author)

Postirradiation examination of capsule GF-4

International Nuclear Information System (INIS)

Kovacs, W.J.; Sedlak, B.J.

1980-10-01

The GF-4 capsule test was irradiated in the SILOE reactor at Grenoble, France between April 8, 1975 and July 26, 1976. High-enriched uranium (HEU) UC 2 and weak acid resin (WAR) UC/sub x/O/sub y/ fissile and ThO 2 fertile particles were tested. Postirradiation examination of cured-in-place fuel rods showed no fuel rod/graphite element interaction. In addition, all rods exhibited adequate structural integrity. Irradiation-induced dimensional changes for rods containing all TRISO-coated fuel were consistent with model predictions; however, rods containing BISO-coated fuel exhibited greater volumetric contractions than predicted

Thermal diffusivity and conductivity of thorium- uranium mixed oxides

Science.gov (United States)

Saoudi, M.; Staicu, D.; Mouris, J.; Bergeron, A.; Hamilton, H.; Naji, M.; Freis, D.; Cologna, M.

2018-03-01

Thorium-uranium oxide pellets with high densities were prepared at the Canadian Nuclear Laboratories (CNL) by co-milling, pressing, and sintering at 2023 K, with UO2 mass contents of 0, 1.5, 3, 8, 13, 30, 60 and 100%. At the Joint Research Centre, Karlsruhe (JRC-Karlsruhe), thorium-uranium oxide pellets were prepared using the spark plasma sintering (SPS) technique with 79 and 93 wt. % UO2. The thermal diffusivity of (Th1-xUx)O2 (0 ≤ x ≤ 1) was measured at CNL and at JRC-Karlsruhe using the laser flash technique. ThO2 and (Th,U)O2 with 1.5, 3, 8 and 13 wt. % UO2 were found to be semi-transparent to the infrared wavelength of the laser and were coated with graphite for the thermal diffusivity measurements. This semi-transparency decreased with the addition of UO2 and was lost at about 30 wt. % of UO2 in ThO2. The thermal conductivity was deduced using the measured density and literature data for the specific heat capacity. The thermal conductivity for ThO2 is significantly higher than for UO2. The thermal conductivity of (Th,U)O2 decreases rapidly with increasing UO2 content, and for UO2 contents of 60% and higher, the conductivity of the thorium-uranium oxide fuel is close to UO2. As the mass difference between the Th and U atoms is small, the thermal conductivity decrease is attributed to the phonon scattering enhanced by lattice strain due to the introduction of uranium in ThO2 lattice. The new results were compared to the data available in the literature and were evaluated using the classical phonon transport model for oxide systems.

Solid-state syntheses and single-crystal characterizations of three tetravalent thorium and uranium silicates

International Nuclear Information System (INIS)

Jin, Geng Bang; Soderholm, L.

2015-01-01

Colorless crystals of ThSiO 4 (huttonite) (1) and (Ca 0.5 Na 0.5 ) 2 NaThSi 8 O 20 (2) have been synthesized by the solid-state reactions of ThO 2 , CaSiO 3 , and Na 2 WO 4 at 1073 K. Green crystals of (Ca 0.5 Na 0.5 ) 2 NaUSi 8 O 20 (3) have been synthesized by the solid-state reactions of UO 2 , CaSiO 3 , and Na 2 WO 4 at 1003 K. All three compounds have been characterized by single-crystal X-ray diffraction. Compound 1 adopts a monazite-type three-dimensional condensed structure, which is built from edge- and corner-shared ThO 9 polyhedra and SiO 4 tetrahedra. Compounds 2 and 3 are isostructural and they crystallize in a steacyite-type structure. The structure consists of discrete pseudocubic [Si 8 O 20 ] 8− polyanions, which are connected by An 4+ cations into a three-dimensional framework. Each An atom coordinates to eight monodentate [Si 8 O 20 ] 8− moieties in a square antiprismatic geometry. Na + and Ca 2+ ions reside in the void within the framework. Raman spectra of 1, 2, and 3 were collected on single crystal samples. 1 displays more complex vibrational bands than thorite. Raman spectra of 2 and 3 are analogous with most of vibrational bands located at almost the same regions. - Graphical abstract: A Raman spectrum and crystal structures of (Ca 0.5 Na 0.5 ) 2 NaAnSi 8 O 20 (An=Th, U), which contain pseudocubic [Si 8 O 20 ] 8− polyanions and eight-coordinate An 4+ cations. - Highlights: • Single crystal growth of three tetravalent actinide silicates from melts. • Single-crystal structures and Raman spectra of (Ca 0.5 Na 0.5 ) 2 NaAnSi 8 O 20 (An=Th, U). • First report of Raman spectrum of huttonite on single crystal samples

Actinide chemistry using singlet-paired coupled cluster and its combinations with density functionals

Science.gov (United States)

Garza, Alejandro J.; Sousa Alencar, Ana G.; Scuseria, Gustavo E.

2015-12-01

Singlet-paired coupled cluster doubles (CCD0) is a simplification of CCD that relinquishes a fraction of dynamic correlation in order to be able to describe static correlation. Combinations of CCD0 with density functionals that recover specifically the dynamic correlation missing in the former have also been developed recently. Here, we assess the accuracy of CCD0 and CCD0+DFT (and variants of these using Brueckner orbitals) as compared to well-established quantum chemical methods for describing ground-state properties of singlet actinide molecules. The f0 actinyl series (UO22+, NpO23+, PuO24+), the isoelectronic NUN, and thorium (ThO, ThO2+) and nobelium (NoO, NoO2) oxides are studied.

Impact of nuclear library difference on neutronic characteristics of thorium-loaded light water reactor fuel

International Nuclear Information System (INIS)

Unesaki, H.; Isaka, S.; Nakagome, Y.

2006-01-01

Impact of nuclear library difference on neutronic characteristics of thorium-loaded light water reactor fuel is investigated through cell burnup calculations using SRAC code system. Comparison of k ∞ and nuclide composition was made between the results obtained by JENDL-3.3, ENDF/B-VI.8 and JEFF3.0 for (U, Th)O 2 fuels as well as UO 2 fuels, with special interest on the burnup dependence of the neutronic characteristics. The impact of nuclear data library difference on k ∞ of (U, Th)O 2 fuels was found to be significantly large compared to that of UO 2 fuels. Notable difference was also found in nuclide concentration of TRU nuclides. (authors)

Once-through thorium fuel cycle evaluation for TVA's Browns Ferry-3 Boiling Water Reactor

International Nuclear Information System (INIS)

Hopkins, G.C.

1982-05-01

This report documents benchmark evaluations to test thorium lattice predictive methods and neutron cross sections against available data and summarizes specific evaluations of the once-through thorium cycle when applied to the Browns Ferry-3 BWR. It was concluded that appreciable uncertainties in thorium cycle nuclear data cloud the ability to reliably predict the fuel cycle performance and that power reactor irradiations of ThO 2 rods in BWRs are desirable to resolve uncertainties. Benchmark evaluations indicated that the ENDF/B-IV data used in the evaluations should cause an underprediction of U-233/ThO 2 fuel reactivity, and, therefore, the results of the preliminary evaluations completed under the program should be conservative

Room temperature ferromagnetism in nano-crystalline Co:ThO2 powders

International Nuclear Information System (INIS)

Bhide, M.K.; Kadam, R.M.; Godbole, S.V.; Tyagi, A.K.; Salunke, H.G.

2012-01-01

The major interest in dilute magnetic semiconductors (DMS's) had been directed towards the synthesis of room temperature ferromagnetic (RTF) materials for their potential applications in spintronic devices. Room temperature (RT) ferromagnetism was initially reported in Co doped TiO 2 , ZnO 2 and SnO 2 thin films and in the recent past in transition metal doped wide band gap materials. In the present paper we report the synthesis of Co doped ThO 2 nano powders by urea combustion method. The XRD characterization of 300℃ annealed samples confirmed formation of ThO 2 in the cubic phase and the average crystallite size obtained using Scherrer's formula was around 6 nm

Investigation of effective factors of transient thermal stress of the MONJU-System components

Energy Technology Data Exchange (ETDEWEB)

Inoue, Masaaki; Hirayama, Hiroshi; Kimura, Kimitaka; Jinbo, M. [Toshiba Corp., Kawasaki, Kanagawa (Japan)

1999-03-01

Transient thermal stress of each system Component in the fast breeder reactor is an uncertain factor on it's structural design. The temperature distribution in a system component changes over a wide range in time and in space. An unified evaluation technique of thermal, hydraulic, and structural analysis, in which includes thermal striping, temperature stratification, transient thermal stress and the integrity of the system components, is required for the optimum design of tho fast reactor plant. Thermal boundary conditions should be set up by both the transient thermal stress analysis and the structural integrity evaluation of each system component. The reasonable thermal boundary conditions for the design of the MONJU and a demonstration fast reactor, are investigated. The temperature distribution analysis models and the thermal boundary conditions on the Y-piece structural parts of each system component, such as reactor vessel, intermediate heat exchanger, primary main circulation pump, steam generator, superheater and upper structure of reactor core, are illustrated in the report. (M. Suetake)

Hydrogeologic reconnaissance of the Mekong Delta in South Vietnam and Cambodia

Science.gov (United States)

Anderson, Henry R.

1978-01-01

The present report describes the results of a hydrogeologic reconnaissance in the Mekong Delta region by the writer, a hydrogeologist of the U.S. Geological Survey, while on assignment as an adviser to the Vietnamese Directorate of Water Supply from October 1968 to April 1970 under the auspices of the U.s. Agency for International Development. The delta of the Mekong River, comprising an area of about 70,000 square kilometres in South Vietnam and Cambodia, is an almost featureless plain rising gradually from sea level to about 5 metres above sea level at its apex 300 kilometres inland. Most of the shallow ground water in the Holocene Alluvium of the delta in Vietnam is brackish or saline down to depths of 50 to 100 metres. Moreover, in the Dong Thap Mu?oi (Plain of Reeds) the shallow ground water is alum-bearing. Locally, however, perched bodies of fresh ground water occur in ancient beach and dune ridges and are tapped by shallow dug wells or pits for village and domestic water supply. The Old Alluvium beneath the lower delta contains freshwater in some areas, notably in the Ca Mau Peninsula and adjacent areas, in the viciniy of Bau Xau near Saigon, and in the Tinh Long An area. Elsewhere in the lower delta both the Holocene and Old Alluvium may contain brackish or saline water from the land surface to depths of as much as 568 metres, as for example in Tinh Vinh Binh. Ground water in the outcrop area of Old Alluvium northwest of Saigon is generally fresh and potable, but high iron and low pH are locally troublesome. Although considerable exploratory drilling for ground water down to depths of as much as 568 metres has already been completed, large areas of the delta remain yet to be explored before full development of the ground-water potential can be realized. With careful development and controlled management to avoid saltwater contamination, however, it is estimated that freshwater aquifers could provide approximately 80 percent of existing needs for village

A preparation method of thorium nitrides and their oxidation behavior

International Nuclear Information System (INIS)

Miyake, M.; Katsura, M.; Uno, M.

1991-01-01

In the preparation of ThN, thermal decomposition of Th 3 N 4 has been performed under various conditions and the kind of products has been examined as a function of temperature and time. In the Th-N-O system there exist ThN, Th 3 N 4 , ThO 2 , and Th 2 N 2 O as solid phases. The thermodynamic stability of these solid compounds has been evaluated as a function of P(O 2 ) and P(N 2 ) and compared with the experimental results. One of the main aims in this work is to explore the oxidation behaviour of thorium nitrides. Preliminary oxidation experiments of ThN and Th 3 N 4 gave the same result. From the study of the air oxidation of Th 3 N 4 , it was found that the oxidation product obtained close to room temperature exhibited only one or more diffuse reflections in its diffraction pattern, suggesting that the product may be of a poor crystalline nature. In order to reveal the dependence of the crystallinity of the product on the oxidation temperature, powdered Th 3 N 4 was exposed to air for one week at 0, 50, and 100degC and the product was examined by X-ray diffraction. In order to prepare ThO 2 with a wide variety of degrees of crystallinity, poorly-crystallized ThO 2 , which is produced by the air oxidation of Th 3 N 4 at 50degC, was heat-treated at temperatures ranging from 200 to 1,400degC in air and vacuum. The degree of crystallinity of ThO 2 heat-treated at and below 1000degC is discussed in terms of the number of detected peaks in the X-ray diffraction patterns, and above 1100degC in terms of the Kα doublet resolution of detected peaks. (author). 11 refs., 7 figs., 6 tabs

Optimization of thorium oxalate precipitation conditions relative to thorium oxide sinterability

International Nuclear Information System (INIS)

White, G.D.; Bray, L.A.; Hart, P.E.

1980-01-01

The effect of thorium oxalate precipitation conditions on derived oxide sinterability was investigated with the objective of producing ThO 2 powder that could be sintered to high density without premilling. Precipitation conditions examined were temperature, digestion time and agitation method which were employed in a two-level factorial experimental design to delineate their effects. The two levels for each of the factors, respectively, were 10 0 C and 70 0 C, 15 min and 360 min, and mechanical stirrer and a homogenizer that imparted both mechanical and ultrasonic agitation. The ThO 2 derived from each of the precipitation trials was characterized with respect to morphology, surface area, and crystallite size as well as sinterability. Only precipitation temperature had a significant effect upon all the properties of the derived oxide powders

Autosomal recessive mutations in THOC6 cause intellectual disability: syndrome delineation requiring forward and reverse phenotyping.

Science.gov (United States)

Amos, J S; Huang, L; Thevenon, J; Kariminedjad, A; Beaulieu, C L; Masurel-Paulet, A; Najmabadi, H; Fattahi, Z; Beheshtian, M; Tonekaboni, S H; Tang, S; Helbig, K L; Alcaraz, W; Rivière, J-B; Faivre, L; Innes, A M; Lebel, R R; Boycott, K M

2017-01-01

THOC6 is a part of the THO complex, which is involved in coordinating mRNA processing with export. The THO complex interacts with additional components to form the larger TREX complex (transcription export complex). Previously, a homozygous missense mutation in THOC6 in the Hutterite population was reported in association with syndromic intellectual disability. Using exome sequencing, we identified three unrelated patients with bi-allelic mutations in THOC6 associated with intellectual disability and additional clinical features. Two of the patients were compound heterozygous for a stop and a missense mutation, and the third was homozygous for a missense mutation; the missense mutations were predicted to be pathogenic by in silico analysis and modeling. Clinical features of the three newly identified patients and those previously reported are reviewed; intellectual disability is moderate to severe, and malformations are variable including renal and heart defects, cleft palate, microcephaly, and corpus callosum dysgenesis. Facial features are variable and include tall forehead, short upslanting palpebral fissures +/- deep set eyes, and a long nose with overhanging columella. These subtle facial features render the diagnosis difficult to make in isolation with certainty. Our results expand the mutational and clinical spectrum of this rare disease, confirm that THOC6 is an intellectual disability causing gene, while providing insight into the importance of the THO complex in neurodevelopment. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Sources of neutronics data involving thorium of 233U and light water moderation

International Nuclear Information System (INIS)

Davenport, L.C.

1978-11-01

A literature search has been conducted to locate sources of neutronics data for light water moderated systems which contain thorium and/or uranium-233. It is concluded that insufficient data is currently available to validate neutronics design methods for licensing the 233 UO 2 -ThO 2 fuel cycle in light water reactors. A summary of the neutronics data sources found is reported in this document. These sources include critical and exponential experiments with lattices of fuel rods containing 233 U + Th or 235 U + Th. A few experiments using homogeneous aqueous solutions of 233 UO 2 (NO 3 ) 2 or 233 UO 2 F 2 are also included. The only critical lattice data using both 233 U and Th came from the LWBR program. All these experiments were zoned radially and in most cases axially also. Geometrically clean lattice critical data were measured for the CETR and TUPE programs. Both series used 235 UO 2 -ThO 2 pellets. A series of 21 exponential experiments using 3% 233 UO 2 - 97% ThO 2 fuel vibratory compacted to 92% of theoretical density in Zircaloy-2 tubing was performed at BNL using both unpoisoned and boric acid poisoned H 2 O moderator. For completeness, homogeneous systems are listed in which basic neutronics data have been measured. However, it is expected that most data concerning homogeneous systems will be applied to criticality safety problems rather than neutronics methods validation

Formation of solid thorium monoxide at near-ambient conditions as observed by neutron reflectometry and interpreted by screened hybrid functional calculations

Energy Technology Data Exchange (ETDEWEB)

He, Heming [Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Majewski, Jaroslaw, E-mail: jarek@lanl.gov [MPA/CINT/Lujan Neutron Scattering Center, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Department of Chemical Engineering, University of California Davis, Davis, CA 95616 (United States); Allred, David D., E-mail: dda@byu.edu [Department of Physics and Astronomy, Brigham Young University Provo, UT 84602 (United States); Wang, Peng [MPA/CINT/Lujan Neutron Scattering Center, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Wen, Xiaodong [Theoretical Division, Los Alamos National Laboratory Los Alamos, NM 87545 (United States); Rector, Kirk D. [Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2017-04-15

Oxidation of a ∼1000 Å sputter-deposited thorium thin film at 150 °C in 100 ppm of flowing oxygen in argon produces the long-sought solid form of thorium monoxide. Changes in the scattering length density (SLD) distribution in the film over the 700-min experiment measured by in-situ, dynamic neutron reflectometry (NR) shows the densities, compositions and thickness of the various thorium oxides layers formed. Screened, hybrid density-functional theory calculations of potential thorium oxides aid interpretation, providing atomic-level picture and energetics for understanding oxygen migration. NR provided evidence of the formation of substoichiometric thorium oxide, ThO{sub y} (y < 1) at the interface between the unreacted thorium metal and its dioxide overcoat which grows inward, consuming the thorium at a rate of 2.1 Å/min while y increases until reaching 1:1 oxygen-to-thorium. Its presence indicates that kinetically-favored solid-phase ThO can be preferentially generated as a majority phase under the thermodynamically-favored ThO{sub 2} top layer at conditions close to ambient. - Highlights: •The long-sought solid form of thorium monoxide forms as thin-film thorium oxidizes. •Density-functional calculations suggest that ThO forms for kinetic reasons. •A pathway to producing ThO as a majority phase for future studies is now open. •Dynamic, in-situ neutron reflectometry is valuable for studying oxidation. •At low oxygen content in the lattice octahedral sites are preferred.

Slip casting of thoria-10 mole per cent yttria solid electrolyte

International Nuclear Information System (INIS)

Ramanathan, S.; Rao, S.V.K.

1990-01-01

One end closed thoria-yttria solid electrolyte have been fabricated by the slip casting technique. A systematic study of the influence of the process parameters on the characteristics of the final bodies has been carried out. Slips of ThO 2 -10 mole % Y 2 O 3 were prepared; their fluidity and castability were studied as a function of concentration, pH and particle size. The bodies were sintered at 2000degC and the physical properties like density and microstructure were evaluated. Slip cast bodies of bulk densities around 95% T.D. with relatively inhomogenous but predominantly fine grained structure could be obtained by optimizing the process variables. (author). 5 figs., 10 refs

Occurrence of monazite in some alluvial soils of North Bihar

International Nuclear Information System (INIS)

Mall, J.; Mishra, B.B.

1994-01-01

Monazite, a thorium-bearing mineral, has been identified in the heavy mineral fractions of the fine sands from the alluvial soil profiles at Barpalia and Gyaspur of Siwan district in north Bihar. The amount of monazite varied from 14.29 to 15.40 per cent and 6.25 to 9.38 per cent of the heavy minerals in the fine sands of Barpalia and Gyaspur, respectively. Monazite could have been derived from the granite pegmatite and gneissic metamorphic rocks in association with feldspar, zircon and apatite from the Himalayan orogan. The amount of 232 Th present in monazite originally ranges from a few wt per cent ThO 2 to 10-12 per cent. Even in the east coast of India , monazite contains 9.05 per cent ThO 2 . (author).5 refs., 2 tabs., 1 fig

Radiological control aspects of the fabrication of the Light Water Breeder Reactor core (LWBR Development Program)

International Nuclear Information System (INIS)

Schultz, B.G.

1979-05-01

A description is presented of the radiological control aspects of the fabrication of the Light Water Breeder Reactor (LWBR) core. Included are the radiological control criteria applied for the design and use of fabrication facilities, the controls and limits imposed to minimize radiaion exposure to personnel, and an evaluation of the applied radiological program in meeting the program objectives. The goal of the LWBR program is to develop the technology to breed in light water reactors so that nuclear fuel may be used significantly more efficiently in these reactors. This technology is being developed by designing and fabricating a breeder reactor core, utilizing thoria (ThO 2 ) and binary thoria--urania (ThO 2 - 233 UO 2 ) fuel, to be operated in the existing pressurized water reactor plant owned by the Department of Energy at Shippingport, Pennsylvania

Factores pronósticos de complicaciones postoperatorias en el trasplante hepático Prognostic factors associated with postoperative complications in liver transplantation

Directory of Open Access Journals (Sweden)

A. Rodríguez-Ariza

2008-03-01

Full Text Available Objetivo: la evolución postoperatoria de los pacientes sometidos a trasplante hepático ortotópico (THO se encuentra frecuentemente asociada a la aparición de diversas complicaciones tales como disfunción renal, rechazo agudo, infecciones y complicaciones neurológicas. Estas complicaciones constituyen las causas más significativas de morbilidad y mortalidad tempranas en pacientes que reciben un THO. El propósito del presente estudio es la identificación de factores relacionados con las distintas complicaciones postoperatorias del THO. Diseño experimental: se llevó a cabo un estudio prospectivo. Pacientes: se analizaron 78 variables en 32 pacientes consecutivos sometidos a THO. Utilizando un análisis de regresión logística se identificaron aquellos factores asociados de forma independiente con la aparición de complicaciones postoperatorias. Resultados: el análisis multivariante demostró que los niveles pretrasplante en suero de malondialdehído y creatinina estaban asociados con el desarrollo de disfunción renal. Los niveles pretrasplante de hemoglobina y las unidades de plaquetas administradas durante la cirugía fueron factores pronósticos de infecciones. El rechazo agudo fue pronosticado por los niveles séricos de γ-glutamil transpeptidasa y de bilirrubina total. Los niveles pretrasplante de sodio y glutaredoxina en suero estuvieron asociados con complicaciones neurológicas. Conclusiones: proponemos estos marcadores para la identificación de pacientes de alto riesgo, permitiendo una vigilancia y/o tratamiento anticipados que mejorarán la morbilidad y la supervivencia en pacientes sometidos a THO.Objectives: the postoperative evolution of patients submitted to orthotopic liver transplant (OLT is frequently associated with the appearance of different types of complications such as renal failure, graft rejection, infections, and neurological disorders. These complications are the most significant causes of early morbidity

A novel brain trauma model in the mouse : effects of dexamethasone treatment

NARCIS (Netherlands)

Hortobágyi, Tibor; Hortobagyi, S; Gorlach, C; Harkany, T; Benbyo, Z; Gorogh, T; Nagel, W; Wahl, M

2000-01-01

We describe a novel methodological approach for inducing cold lesion in the mouse as a model of human cortical contusion trauma. To validate its reproducibility and reliability, dexamethasone (Dxm) was repeatedly applied to demonstrate possible antioedematous drug effects. Following tho induction of

Combustion/absorption process for the separation of {sup 14}C and {sup 3}H in radwastes released from nuclear power plants and their analysis

Energy Technology Data Exchange (ETDEWEB)

Ko, Young Gun, E-mail: ygko@kaeri.re.kr; Kim, Chang-Jong; Cho, Young Hyun; Chung, Kun Ho; Kang, Mun Ja

2017-06-05

Highlights: • {sup 14}CO{sub 2} and THO were produced by the combustion of radwaste samples. • The radioactivity of {sup 14}CO{sub 2} and THO absorbed sorbents were measured by LSC. • The CO{sub 2} absorption in the {sup 14}C sorbent was analyzed using by FT-IR and a rheometer. • The temperature and viscosity of the CO{sub 2} absorbed {sup 14}C sorbent was investigated. - Abstract: Radioactivities of {sup 3}H and {sup 14}C in spent radioactive ion exchange resins and spent radioactive lubricant oils released from nuclear power plants, has been determined using a combustion and sorption method (combustion method). The liquid scintillation counting (LSC) spectra showed that the interference of other radionuclides has not significantly affected the determination of radioactivities of {sup 3}H and {sup 14}C in the radwaste samples. The chemical structure of {sup 14}CO{sub 2}, which originated from the combustion of radwastes, trapped {sup 14}C sorbent has been investigated using Fourier transform infrared spectroscopy (FT-IR). FT-IR study showed interesting results that peaks for uncoupled CO{sub 2} and carbonic amide appeared at FT-IR spectra of CO{sub 2} high-absorbed {sup 14}C sorbents, while the peak for carbamate was only observed at the spectra of CO{sub 2} low-absorbed sorbents. During the CO{sub 2} sorption in {sup 14}C sorbent, temperature and viscosity of the sorbent increased owing to decrease of enthalpy and increase of apparent molecular weight of the sorbent caused by the bonding formation between sorbent molecules.

Mechanism of extractive/oxidative desulfurization using the ionic liquid inimidazole acetate: a computational study.

Science.gov (United States)

Wang, Hanlu; Xu, Mingsheng; Zhou, Rujin

2017-02-01

The dual role of the ionic liquid 1-butyl-3-methyl-imidazolium trifluoroacetic acid ([C 4 mim]TFA) as an extractant for thiophene (TH) and a catalyst for the oxidation of TH was explored at the molecular level by performing density functional theory (DFT) calculations. The calculated interaction energies demonstrated why [C 4 mim]TFA is a better extractant for thiophene sulfone (THO 2 ) than for TH. Two pathways were proposed for the oxidation of TH to THO 2 with [C 4 mim]TFA acting as a catalyst. In the dominant pathway, a peracid is formed which then oxidizes TH to the sulfoxide and sulfones. The presence of [C 4 mim]TFA was found to greatly reduce the barrier to the oxidative desulfurization (ODS) of TH using H 2 O 2 as an oxidant. Graphical Abstract Possible reaction mechanisms of TH with the aid of [C4mim]TFAᅟ.

Transfer and incorporation of tritium in mammals

International Nuclear Information System (INIS)

Hoek, J. van den; Juan, N.B.

1979-01-01

The metabolism of tritium in mammals has been studied in a number of laboratories which have participated in the IAEA Co-ordinated Research Programme on the Behaviour of Tritium in the Environment. The results of these studies are discussed and related to data obtained elsewhere. The animals studied are small laboratory and domestic animals. Tritium has been administered as THO, both in single and long-term dosing experiments, and also as organically bound tritium. The biological half-life of tritium in the body water pool has been determined in different species. The following values have been found: 1.1 days in mice; 13.2 days in kangaroo rats; 3.8 days in pigs; 4.1 days in lactating versus 8.3 in non-lactating goats and 3.1-4.0 days in lactating cows and steers. Much attention has been paid to the incorporation of tritium into organic constituents, both in the animal organism (organs, tissues) and in the secretions of the animal after continuous administration of tritium, mostly as THO. When compared with tritium levels in body water, and expressed as the ratio of specific activities, values of 0.25 and 0.40 have been found in mice liver and testis respectively. In cow's milk, these ratios vary from 0.30 for casein to 0.60 for lactose. The transfer of tritium into milk after continuous ingestion of THO by a lactating cow is about 1.50% of the daily ingested tritium per litre of milk. Some results of experiments, utilizing organically bound tritium, are also presented. (author)

SAMJ

African Journals Online (AJOL)

the use of a cement gun, with or without venting, and effective ... have all been u ed in an anempt ro redu e the tiffne ofthefemoral tern ... acetabular revi ion in tho e components ....'ith 32 .... ing technology, cost-containment must remain a prag-.

Critical Evaluation of a Human In Vitro Biotransformation Rate Database

Science.gov (United States)

Chemical biotransformation is critical information in the understanding of how a chemical may elicit health effects in humans or in the environment. Despite the fundamental value of these data, very relatively few measured in vivo data are available for humans compared to the tho...

Estudio comparativo de la eficacia terapéutica de oxitetraciclina, imidocarb y diminazeno, utilizados en el tratamiento de hemoparasitosis en equinos pura sangre de carrera

DEFF Research Database (Denmark)

Comerma Steffensen, Simon Gabriel; Arrieta-Mendoza, D.; Morales, A

2012-01-01

It presents a comparative study of the therapeutic efficacy of oxytetracycline, imidocarb and diminaze- ne, used in the treatment of equine hemoparasitosis Thoroughbreds. We studied a total of 105 horses, Tho- roughbreds, all under 2 years old, during the quarantine period November to December 20...

Influence of pesticide information sources on citrus farmer's knowledge, perception and practices in pest management, Mekong Delta, Vietnam

NARCIS (Netherlands)

Mele, van P.; Hai, T.V.; Thas, O.; Huis, van A.

2002-01-01

In 1998-99, about 150 citrus farmers and 120 pesticide sellers were interviewed in Can Tho and Dong Thap province, Mekong Delta, Vietnam. Media, pesticide sellers and extension staff had different influences on farmers' pest perception and management practices depending on the region and intensity

Hepatitis C virus (HCV) RNA profiles among chronic HIV/HCV-coinfected individuals in ESPRIT; spontaneous HCV RNA clearance observed in nine individuals

DEFF Research Database (Denmark)

Grint, D; Tedaldi, Ellen; Peters, L

2017-01-01

OBJECTIVES: Studies have shown that hepatitis C virus (HCV) RNA levels remain stable over time in HIV/HCV-coinfected individuals taking combination antiretroviral therapy (cART), while spontaneous clearance of HCV RNA during the persistent infection phase has been documented only rarely among tho...

v V V V V v

Indian Academy of Sciences (India)

after glass has been exposed for .. long time to the impact of these rays, the intensity of its .... meter, but that when the rays reach the cylinder there is at once a .... dark, while the luminosity occupies tho space between the arms of the cross.

Structural characterization of M(IV)1-xLn(III)xO2-x/2 (M = Ce, Th) mixed-oxides prepared from oxalate precursors. Multi-parametric study of dissolution and microstructural evolution

International Nuclear Information System (INIS)

Horlait, D.

2011-01-01

In the framework of Gen IV program development, several physico-chemical properties of some foreseen fuels, including the chemical durability, have to be evaluated. In this aim, a study was undertaken on M(IV) 1-x Ln(III) x O 2 (M=Ce,Th) model compounds prepared from oxalate precursors. The fluorite-type structure of CeO 2 and ThO 2 remains stable up to x ≅ 0.4, the substitution of M(IV) by Ln(III) occurring simultaneously to the formation of oxygen vacancies. For higher x values, a cubic superstructure is formed as a result of oxygen vacancies ordering. The normalized dissolution rates of such solids were found to be strongly enhanced by the Ln(III) fraction. On the contrary, the nature of the M(IV) and Ln(III) elements did not modify significantly the normalized dissolution rates. The effect of temperature and acid concentration suggested the existence of surface-controlling dissolution reactions. Simultaneously, the microstructural evolution of both powdered and sintered samples revealed some important changes in the reactive surface during dissolution tests. ESEM images allowed observing the existence of preferential dissolution sites located at grains boundaries and around crystalline defects, leading to the formation of corrosion pits. In addition, the formation of gelatinous phases, acting as diffusion barriers (thus slowing down the dissolution process) was also evidenced. (author) [fr

The permanent electric dipole moment of thorium sulfide, ThS.

Science.gov (United States)

Le, Anh; Heaven, Michael C; Steimle, Timothy C

2014-01-14

Numerous rotational lines of the {18.26}1-X(1)Σ(+) band system of thorium sulfide, ThS, were recorded near 547.6 nm at a resolution of approximately 30 MHz. Measurements were made under field-free conditions, and in the presence of a static electric field. The field-free spectrum was analyzed to produce rotational and Λ-doubling parameters. The Stark shifts induced by the electric field were analyzed to determine permanent electric dipole moments, μ⃗el, of 4.58(10) D and 6.72(5) D for the X(1)Σ(+) (v = 0) and {18.26}1 states, respectively. The results are compared with the predictions of previous and new electronic structure calculations for ThS, and the properties of isovalent ThO.

Nothingness and the Forgotten

DEFF Research Database (Denmark)

Jensen, Tine

2016-01-01

This chapter takes an onset in forgetting and applies Karen Barad’s agential realism to the phenomenon. The question here is neither about retrieval problems, as forgetting is coined in cognitive science, nor is it about psychoanalytical concepts of repression. Rather, this chapter conducts a tho...

Characterization and Aerosol Mass balance of PM2.5 and PM10 Collected in Conakry, Guinea during the 2004 Harmattan Period

Science.gov (United States)

The United States EPA conducted a six week air quality survey of the city of Conakry, Guinea, West Africa in 2004. The study was conducted to assess the background levels of anthropogenic and natural particulate matter (PM) and to investigate the local and regional sources of tho...

Continuous, flexible, and high-strength superconducting Nb3Ge and Nb3Sn filaments

International Nuclear Information System (INIS)

Ahmad, I.; Heffernan, W.J.

1976-01-01

Fabrication of continuous, flexible, and high-strength (1600 MN/m 2 ) composite filaments of Nb 3 Ge (T/subc/ 18 0 K) and Nb 3 Sn is reported, involving chemical vapor deposition of these compounds on Nb-coated high-strength W--1% ThO 2 filaments

Chemical characterization of materials by inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Deb, S.B.; Nagar, B.K.; Saxena, M.K.; Ramakumar, K.L.

2009-11-01

An Inductively Coupled Plasma Mass Spectrometer was procured for trace elemental determination in diverse samples. Since its installation a number of analytical measurements have been carried out on different sample matrices. These include chemical quality control measurements of nuclear fuel and other materials such as uranium metal. Uranium peroxide, ADU, ThO 2 , UO 2 ; isotopic composition of B, Li; chemical characterization of simulated ThO 2 + 2%UO 2 fuel; sodium zirconium phosphate and trace metallic elements in zirconium; Antarctica rock samples and wet phosphoric acid. Necessary separation methodologies required for effective removal of matrix were indigenously developed. In addition, a rigorous analytical protocol, which includes various calibration methodologies such as mass calibration, response calibration, detector cross calibration and linearity check over the entire dynamic range of 109 required for quantitative determination of elements at trace and ultra trace level,, has been standardized. This report summarizes efforts of RACD that have been put in this direction for the application of ICP-MS for analytical measurements. (author)

Fuel cycle model and the cost of a recycling thorium in the CANDU reactor

International Nuclear Information System (INIS)

Choi, Hangbok; Park, Chang Je

2005-01-01

The dry process fuel technology has a high proliferation-resistance, which allows applications not only to the existing but also to the future nuclear fuel cycle systems. In this study, the homogeneous ThO 2 -UO 2 recycling fuel cycle in a Canada deuterium uranium (CANDU) reactor was assessed for a fuel cycle cost evaluation. A series of parametric calculations were performed for the uranium fraction, enrichment of the initial uranium fuel, and the fission product removal rated of the recycled fuel. The fuel cycle cost was estimated by the levelized lifetime cost model provided by the Organization for Economic Cooperation and Development/Nuclear Energy Agency. Though it is feasible to recycle the homogeneous ThO 2 -UO 2 fuel in the CANDU reactor from the viewpoint of a mass balance, the recycling fuel cycle cost is much higher than the conventional natural uranium fuel cycle cost for most cases due to the high fuel fabrication cost. (author)

Neutronic performance of a fusion-fission hybrid reactor designed for fuel enrichment for LWRs

International Nuclear Information System (INIS)

Yapici, H.; Baltacioglu, E.

1997-01-01

In this study, the breeding performance of a fission hybrid reactor was analyzed to provide fissile fuel for Light Water Reactors (LWR) as an alternative to the current methods of gas diffusion and gas centrifuge. LWR fuel rods containing UO 2 or ThO 2 fertile material were located in the fuel zone of the blanket and helium gas or Flibe (Li 2 BeF 4 ) fluid was used as coolant. As a result of the analysis, according to fusion driver (D,T and D,D) and the type of coolant the enrichment of 3%-4% were achieved for operation periods of 12 and 36 months in case of fuel rods containing UO 2 , respectively and for operation periods of 18 and 48 months in case of fuel rods containing ThO 2 , respectively. Depending on the type of fusion driver, coolant and fertile fuel, varying enrichments of between 3% and 8.9% were achieved during operation period of four years

Production of 231Pa and 232U by irradiation of 230Th/232Th mixtures

International Nuclear Information System (INIS)

Kluge, E.; Lieser, K.H.

1981-01-01

The production of 231 Pa and of 232 U by irradiating a 230 Th/ 232 Th mixture (containing 12 mol per cent 230 Th) in form of ThO 2 at a thermal neutron flux of 6.9 x 10 13 cm -2 s -1 for 4 months was investigated. Pa, U and Th were separated and the chemical yields were determined. 2.6% of the 230 Th were transformed into 231 Pa and 0.13% into 232 U. These values are higher than those calculated for a thermal flux, but lower than those calculated for a flux ratio epithermal to thermal = 0.03. 231 Pa and 232 U were isolated in form of a protactinium solution and of U 3 O 8 with 94.9 and 89.1% chemical yields, respectively. Foreign activities were not detected. Thorium was recuperated and isolated as ThO 2 , with a chemical yield of 93.6%. (orig.)

High-Speed Visualization of Evaporation Phenomena from Tungsten Based Electrode in Multi-Phase AC Arc

Science.gov (United States)

Tanaka, Manabu; Hashizume, Taro; Imatsuji, Tomoyuki; Nawata, Yushi; Watanabe, Takayuki

2015-09-01

A multi-phase AC arc has been developed for applications in various fields of engineering because it possesses unique advantages such as high energy efficiency. However, understanding of fundamental phenomena in the multi-phase AC arc is still insufficient for practical use. Purpose of this study is to investigate electrode erosion mechanism by high-speed visualization of the electrode metal vapor in the arc. Results indicated that the electrode mainly evaporated at anodic period, leading to the arc constriction. Moreover, evaporation of W electrode with 2wt% La2O3 at the anodic period was much higher than that with 2wt% ThO2. This can be explained by different properties of these oxide additives. Evaporation of the oxide additive resulted in the arc constriction, which accelerated the evaporation of W electrode. Therefore, addition of La2O3 with lower melting and boiling point than ThO2 lead to stronger arc constriction, resulting in severer evaporation of W electrode.

Surface Water Investigations in Afghanistan: A Summary of Activities from 1952 to 1969. Appendix 5: End of Tour Report. United States Operations Mission to Afghanistan; International Cooperation Administration, Lashkar Gah, Afghanistan

Science.gov (United States)

1966-05-01

Royal Government of Afghanistan under the auspices of the United States Agency for International Development. 18 appendices. 15. SUBJECT TERMS...village leaders; third, the transfer to Kob-ol of Kr. Chulan Shell t;ho, altliou^o. a ’ . S* graduate engineer (at AID espenoe), has no interest in

Another Theory is Possible

DEFF Research Database (Denmark)

Manners, Ian James

2016-01-01

The article argues that dissident voices which attempt to theorise Europe differently and advocate another European trajectory have been largely excluded and left unheard in mainstream discussions over the past decade of scholarship and analysis. Dissident voices in European Union studies are tho...... theory, is possible – indeed, probable....

Spectrographic analysis of thorium and its compounds

International Nuclear Information System (INIS)

Grampurohit, S.V.; Saksena, M.D.; Kaimal, V.N.P.; Kapoor, S.K.; Murty, P.S.

1980-01-01

A spectrographic method, which employs the principle of carrier-distillation technique, is described for the analysis of high purity thoria. Two carriers, AgCl and NaF were used in determining 27 trace elements in ThO 2 . The elements were divided into three groups, A, B and C. In group A, 15 elements, viz. Al, B, Be, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sb, Si and Sn were included since it was possible to choose sensitive lines of these elements in one spectral region, 220 - 285 nm. Group B covered 8 elements, viz. Ag, Bi, Ca, Ga, Mo, Ti, V and Zn, which could be determined in the spectral region 290 - 352.5 nm. Group C consisted 4 elements, viz. Ba, K, Li and Na which could be determined in the spectral region 440 - 820 nm. 5% AgCl was used as the carrier for the determination of groups A and C elements and 4% NaF was used as the carrier for the estimation of group B elements. One hundred milligrammes of the sample (in the form of ThO 2 ) containing the carrier were taken in a carrier-distillation electrode and excited in a d.c. arc (10 amps for groups A and C; 15 amps for group B). The spectra of sample and synthetic standards were photographed on Hilger's large quartz, JACO 3.4 m Ebert plane grating and Higler's large glass spectrographs respectively for determining group A, B and C elements. The detection limit obtained for B and Cd was 0.1 ppm. Thorium metal and thorium nitrate samples were converted to ThO 2 prior to analysis. (auth.)

Transmutation of minor actinides in a Candu thorium borner

International Nuclear Information System (INIS)

Sahin, S.; Sahin, H. M.; Acir, A.; Yalcin, S.; Yildiz, K.; Sahin, N.; Altinok, T.; Alkan, M.

2007-01-01

The paper investigates the prospects of exploitation of rich world thorium reserves in CANDU reactors. Large quantities of plutonium have been accumulated in the nuclear waste of civilian LWRs and CANDU reactors. Reactor grade plutonium can be used as a booster fissile fuel material in form of mixed ThO 2 /PuO 2 fuel in a CANDU fuel bundle in order to assure reactor criticality. Two different fuel compositions have been selected for investigations: 1) 96% thoria (ThO 2 ) + 4% PuO 2 and 2) 91% ThO 2 + 5% UO 2 + 4 PuO 2 . The latter is used for the purpose of denaturing the new 2 33U fuel with 2 38U. The behavior of the criticality k ∞ and the burn-up values of the reactor have been pursued by full power operation for > ∼ 8 years. The reactor starts with k ∞ = ∼ 1.39 and the criticality drops down asymptotically to values k ∞ > 1.06, still tolerable and usable in a CANDU reactor. Reactor criticality k ∞ remains nearly constant between the 4th year and 7th year of plant operation and then a slight increase is observed thereafter, along with a continuous depletion of thorium fuel. After the 2nd year, the CANDU reactor begins to operate practically as a thorium burner. Very high burn up can be achieved with the same fuel (> 160 000 MW.D/MT). The reactor criticality would be sufficient until a great fraction of the thorium fuel is burnt up, provided that the fuel rods could be fabricated to withstand such high burn up levels. Fuel fabrication costs and nuclear waste mass for final disposal per unit energy could be reduced drastically. There is a great quantity of weapon grade plutonium accumulated in nuclear stockpiles. In the second phase of investigations, weapon grade plutonium is used as a booster fissile fuel material in form of mixed ThO 2 /PuO 2 fuel in a CANDU fuel bundle in order to assure the initial criticality at startup. Two different fuel compositions have been used: 1) 97% thoria (ThO 2 ) + 3% PuO 2 and 2) 92% ThO 2 + 5% UO 2 + 3% PuO 2 . The

Development of thoria certified reference materials-role of NFC

International Nuclear Information System (INIS)

Balaji Rao, Y.; Yadav, R.B.; Ramana Rao, A.V.

2007-01-01

The present paper discusses the different phases of Inter Laboratory Comparison Experiments (ILCE) program for development of thoria CRMs with a special emphasis on the role played by Control Laboratory, NFC. The preparation of ThO 2 CRMs along with their importance in analysis is also explained in the paper. (author)

The permanent electric dipole moment of thorium sulfide, ThS

Energy Technology Data Exchange (ETDEWEB)

Le, Anh; Steimle, Timothy C., E-mail: Tsteimle@ASU.edu [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604 (United States); Heaven, Michael C. [Department of Chemistry, Emory University, Atlanta, Georgia 30322 (United States)

2014-01-14

Numerous rotational lines of the (18.26)1-X{sup 1}Σ{sup +} band system of thorium sulfide, ThS, were recorded near 547.6 nm at a resolution of approximately 30 MHz. Measurements were made under field-free conditions, and in the presence of a static electric field. The field-free spectrum was analyzed to produce rotational and Λ-doubling parameters. The Stark shifts induced by the electric field were analyzed to determine permanent electric dipole moments, μ{sup -vector}{sub el}, of 4.58(10) D and 6.72(5) D for the X{sup 1}Σ{sup +} (v = 0) and (18.26)1 states, respectively. The results are compared with the predictions of previous and new electronic structure calculations for ThS, and the properties of isovalent ThO.

Zeolite-catalyzed isomerization of tetroses in aqueous medium

DEFF Research Database (Denmark)

Shunmugavel, Saravanamurugan; Riisager, Anders

2014-01-01

(THO) (corresponding to the equilibrium mixture), i.e. total tetrose yield 90 %, after reaction for 5-7 h at 120 °C. Changing the solvent from water to methanol decreased the yield of ERU markedly to 18 %, and gave only a total yield of tetroses of 27 % which is significantly lower than obtained...

Connections between transcription, mRNP assembly and quality control in S. cerevisiae

DEFF Research Database (Denmark)

Jensen, Torben Heick

in the context of THO and rna14-3 mutants improves mRNP quality by acting upstream of transcription-site retention and nuclear degradation of the transcripts. As Rad3p mutant effects can be phenocopied by other mutations known to affect transcription and by the addition of transcription elongation drugs, our...

Failure mechanisms in high temperature gas cooled reactor fuel particles

International Nuclear Information System (INIS)

Soo, P.; Uneberg, G.; Sabatini, R.L.; Schweitzer, D.G.

1979-01-01

BISO coated UO 2 and ThO 2 particles were heated to high temperatures to determine failure mechanisms during hypothetical loss of coolant scenarios. Rapid failure begins when the oxides are reduced to liquid carbides. Several failure mechanisms are applicable, ranging from hole and crack formation in the coatings to catastrophic particle disintegration

Optical properties of ThO2–based nanoparticles

International Nuclear Information System (INIS)

Pereira, F.J.; Castro, M.A.; Vázquez, M.D.; Debán, L.; Aller, A.J.

2017-01-01

Thoria nanomaterials show great interest in different fields other than nuclear technology. In this work, optical characteristics of four types of thoria-based nanoparticles were evaluated. The ultraviolet-visible (UV–vis) absorption spectrum of the pure (undoped/uncapped) thoria nanoparticles was characterised by an intense peak at 222 nm, while the doped/capped thoria nanoparticles shown maximum absorption peaks at both 195/200 nm and 233 nm. Contrarily to the particle size, the band gap energy of the thoria nanoparticles decreased with the doping/capping process using arsenic (As (III) )/cysteine (Cyst). The room-temperature photoluminescence excitation spectra were featured by two bands located at 268 nm for both pure and As-doped thoria nanoparticles and at 352 nm for all thoria-based nanoparticles studied, recording the photoluminescence emission at 500 nm. The characteristic wavelengths of the photoluminescence emission spectra were at 325 and 385 nm for the pure and As-doped thoria nanoparticles, while only the band at 385/415 nm was noted for the Cyst-capped thoria nanoparticles, with slightly red shift depending on the excitation wavelength.

Accurate determination of ultra-trace levels of Ti in blood serum using ICP-MS/MS

International Nuclear Information System (INIS)

Balcaen, Lieve; Bolea-Fernandez, Eduardo; Resano, Martín; Vanhaecke, Frank

2014-01-01

Graphical abstract: -- Highlights: •Novel method for determination of Ti at ultra-trace levels in clinical samples (serum). •Novel method based on Ti(NH 3 ) 6 + reaction product ion formation and double mass selection using recently introduced ICP-QQQ instrumentation. •Lowest limits of detection ever obtained using quadrupole-based instrumentation for Ti. •Accurate determination of basal levels of Ti in blood serum. -- Abstract: Ti is frequently used in implants and prostheses and it has been shown before that the presence of these in the human body can lead to elevated Ti concentrations in body fluids such as serum and urine. As identification of the exact mechanisms responsible for this increase in Ti concentrations, and the risks associated with it, are not fully understood, it is important to have sound analytical methods that enable straightforward quantification of Ti levels in body fluids (for both implanted and non-implanted individuals). Until now, only double-focusing sector field ICP-mass spectrometry (SF-ICP-MS) offered limits of detection that are good enough to deal with the very low basal levels of Ti in human serum. This work reports on the development of a novel method for the accurate and precise determination of trace levels of Ti in human serum samples, based on the use of ICP-MS/MS. O 2 and NH 3 /He have been compared as reaction gases. While the use of O 2 did not enable to overcome all spectral interferences, it has been shown that conversion of Ti + ions into Ti(NH 3 ) 6 + cluster ions by using NH 3 /He as a reaction gas in an ICP-QQQ-MS system, operated in MS/MS mode, provided interference-free conditions and sufficiently low limits of detection, down to 3 ng L −1 (instrumental detection limit obtained for the most abundant Ti isotope). The accuracy of the method proposed was evaluated by analysis of a Seronorm Trace Elements Serum L-1 reference material and by comparing the results obtained with those achieved by means of SF

Advanced methods for fabrication of PHWR and LMFBR fuels

International Nuclear Information System (INIS)

Ganguly, C.

1988-01-01

For self-reliance in nuclear power, the Department of Atomic Energy (DAE), India is pursuing two specific reactor systems, namely the pressurised heavy water reactors (PHWR) and the liquid metal cooled fast breeder reactors (LMFBR). The reference fuel for PHWR is zircaloy-4 clad high density (≤ 96 per cent T.D.) natural UO 2 pellet-pins. The advanced PHWR fuels are UO 2 -PuO 2 (≤ 2 per cent), ThO 2 -PuO 2 (≤ 4 per cent) and ThO 2 -U 233 O 2 (≤ 2 per cent). Similarly, low density (≤ 85 per cent T.D.) (UPu)O 2 pellets clad in SS 316 or D9 is the reference fuel for the first generation of prototype and commercial LMFBRs all over the world. However, (UPu)C and (UPu)N are considered as advanced fuels for LMFBRs mainly because of their shorter doubling time. The conventional method of fabrication of both high and low density oxide, carbide and nitride fuel pellets starting from UO 2 , PuO 2 and ThO 2 powders is 'powder metallurgy (P/M)'. The P/M route has, however, the disadvantage of generation and handling of fine powder particles of the fuel and the associated problem of 'radiotoxic dust hazard'. The present paper summarises the state-of-the-art of advanced methods of fabrication of oxide, carbide and nitride fuels and highlights the author's experience on sol-gel-microsphere-pelletisation (SGMP) route for preparation of these materials. The SGMP process uses sol gel derived, dust-free and free-flowing microspheres of oxides, carbide or nitride for direct pelletisation and sintering. Fuel pellets of both low and high density, excellent microhomogeneity and controlled 'open' or 'closed' porosity could be fabricated via the SGMP route. (author). 5 tables, 14 figs., 15 refs

Economic Cost and Benefits of Subsidizing Western Credits to the East,

Science.gov (United States)

1984-07-01

these reports it is possible to calculate the scheduled repayments and deter- mine the extent to which these repayments were not made. Table 5...It was bleved tha in am of sp- MOM dfficultee, the Soviet would aasf their satllfML Th& ocabld uubftf hrtbyo tho ouhl dis dited b nosut expesLne .4. p

Evaluation of the quasi-isothermal method of modulated DSC for heat capacity measurement

International Nuclear Information System (INIS)

Venkata Krishnan, R.; Nagarajan, K.

2004-01-01

Heat capacity measurements were carried out on ThO 2 by Modulated Differential Scanning Calorimetry (MDSC) using quasi-isothermal method in the temperature range 323-723 K. The highest accuracy of the heat capacity data obtained by this method was ± 2-3% which is much lower than that reported in the literature. (author)

Geochemical behaviour of U3O8, Mo, Y, Ga, V and Zr in laterite - bauxitic sequence of the ''Croanta-Paragominas''

International Nuclear Information System (INIS)

Ferraioli, R.N.M.; Ferreira, Z.C.A.

1987-10-01

Fifteen samples are studied, analyzed for U 3 O 8 (delayed neutrons), ThO 2 (X-ray fluorescence spectrometry) and Mo, Y, Ga, V and Zr (optical emission spectrography) in laterite - bauxitic sequence of the Paragominas, Brazil. Generical datas about the arrangements of thorium, uranium and zirconium are also presented. (C.G.C.) [pt

Resonance integral calculations for isolated rods containing oxides of 238U and 232Th

International Nuclear Information System (INIS)

Baker, V.C.; Marable, J.H.

1980-02-01

Results of resonance integral calculations for UO 2 and ThO 2 isolated rods are discussed. The calculations were performed with ENDF/B-IV cross-section data and the multigroup transport code ANISN. The findings reported demonstrate by comparison with semiempirical relationships (based on experimentally derived results) the suitability of the method used for determining resonance integrals. The calculations were based on a cylindrical rod in an H 2 O moderator of large radius. Multigroup cross sections were obtained by a MINX-SPHINX-AMMPX sequence, and ANISN was used to account for the neutron flux and capture rates. A special approach was used to determine a neutron source distribution such that the flux in the moderator region was forced to behave in an asymptotic way; thus, the ideal resonance integral experiment could be calculated. The UO 2 resonance integrals calculated were in exceptionally good agreement with experimental values based on isolated rods. The ThO 2 results were approximately 6% lower than experimental values, and efforts to understand the discrepancy are discussed. 8 figures, 7 tables

Carbon dioxide electrolysis using a ceramic electrolyte. [for space processing

Science.gov (United States)

Erstfeld, T. E.; Mullins, O., Jr.; Williams, R. J.

1979-01-01

This paper discusses the results of an experimental study of the electrical aspects of carbon dioxide electrolysis using a ceramic electrolyte. The electrolyte compositions used in this study are 8% Y2O3 stabilized ZrO2, 7.5% CaO stabilized ZrO2, and 5% Y2O3 stabilized ThO2. Results indicate that the 8% Y2O3 stabilized ZrO2 is the best material to use for electrolysis, in terms of current as a function of voltage and temperature, and in terms of efficiency of oxide ion flow through it. The poorest results were obtained with the 5% Y2O3 stabilized ThO2 composition. An electrolysis system which might be employed to reclaim oxygen and carbon from effluents of space manufacturing, assuming that an industry would have to electrolyze 258,000 tonnes of CO2 per year, is predicted to require a total cell area of 110,000 sq m of 1 mm thickness and electrical capacity of 441 MW.

A preliminary simulation of an ADS using MCNPX for U233 production

International Nuclear Information System (INIS)

Barros, Graiciany P.; Pereira, Claubia; Veloso, Maria A.F.; Costa, Antonella L.

2009-01-01

The code MCNPX is used to evaluate a simplified model of a hybrid system regenerator accelerator (ADS - Accelerator Driven Subcritical), for energy and 233 U production. The concept consists of coupling a high-energy particle accelerator with a sub-critical reactor core, using 232 ThO 2 + 233 UO 2 as initial composition. In this work, the spallation source definition used in MCNPX is a point source of 1000 MeV. The system consists in three coaxial cylinders. The internal cylinder is the spallation target that is a thick natural Pb. The intermediate cylinder is the core, composed by the mixture of fuel ( 232 ThO 2 + 9.5% 233 UO 2 ) and Pb coolant; and lead, as reflector, composes the external cylinder. The goal is to begin studies to evaluate the regenerator blanket composition when submitted to a neutron flux during a time step. The effective multiplication coefficient of the system and the variation of the composition of the regenerative layer are analyzed. The preliminary results show the possibility of utilization of this system. (author)

Thermal diffusivity and thermal conductivity of (Th,U)O2 fuels

International Nuclear Information System (INIS)

Sengupta, A.K.; Jarvis, T.; Nair, M.R.; Ramachandran, R.; Mujumdar, S.; Purushotham, D.S.C.

2000-05-01

India has vast reserves of thorium (> 460,000 tons) and sustained work on all aspects of thorium utilization has been initiated. In this context work on fabrication of sintered thoria and mixed (Th,U)O 2 pellets and evaluation of their thermophysical properties have been taken up in Radiometallurgy Division. Thermal conductivity, being the most important thermal properties, has been calculated using the experimentally measured thermal diffusivity, density and literature values of specific heats for ThO 2 and thoria containing 2,4,6,10 and 20% UO 2 . Thermal diffusivity was measured experimentally by the laser flash method from 600 to 1600 deg C in vacuum. It was observed that thermal conductivity of ThO 2 and mixed (Th,U)O 2 decrease with increase in temperature. It was also observed that the conductivity decreases with increase in UO 2 content, the decrease being more at lower temperature than that at higher temperatures. Empirical relations correlating thermal conductivity to temperatures have been generated by the least square fit method and reported. (author)

Atomistic modeling of the solid-state chemistry of actinide materials

Science.gov (United States)

Shuller, Lindsay C.

Materials that incorporate actinides are critical to the nuclear fuel cycle, either as nuclear fuels or nuclear waste forms. In this thesis, I examine four materials: i) ThO2-UO2 solid solutions, ii) binary ThO2-CeO2-ZrO2 solid solutions, iii) Np-doped studtite, iv) Np-doped boltwoodite. Computational methods, particularly density functional theory (DFT) calculations and Monte-Carlo (MC) simulations, are used to determine the energetics and structures of these actinide-bearing materials. The solid-solution behavior of nuclear fuels and nuclear waste forms indicate the thermodynamic stability of the material, which is important for understanding the in-reactor fuel properties and long-term stability of used fuel. The ThxU1-xO2 and ThxCe 1-xO2 binaries are almost completely miscible; however, DeltaGmix reveals a small tendency for the systems to exsolve (e.g., DeltaEexsoln(Th xU1-xO2) = 0.13 kJ/(mol cations) at 750 K). Kinetic hindrances (e.g., interfacial energy) may inhibit exsolution, especially at the low temperatures necessary to stabilize the nanoscale exsolution lamellae observed in the ThxU1-xO2 and Ce xZr1-xO2 binaries. Miscibility in the Zr-bearing binaries is limited. At 1400 °C, only 3.6 and 0.09 mol% ZrO2 is miscible in CeO2 and ThO2, respectively. The incorporation of minor amounts of Np5+,6+ into uranium alteration phases, e.g., studtite [UO2O2 (H2O)4] or boltwoodite [K(UO2)(SiO 3OH)(H2O)1.5] , may limit the mobility of aqueous neptunyl complexes released from oxidized nuclear fuels. Np6+-incorporation into studtite requires less energy than Np5+-incorporation (e.g., with source/sink = Np2O5/UO 3 DeltaEincorp(Np6+) = 0.42 eV and DeltaEincorp(Np5+) = 1.12 eV). In addition, Np6+ is completely miscible in studtite at room temperature with respect to a hypothetical Np6+-studtite. Electronic structure calculations provide insight into Np-bonding in studtite. The Np 5f orbitals are within the band gap of studtite, resulting in the narrowing of the band gap

What makes biology unique?: considerations on the autonomy of a scientific discipline

National Research Council Canada - National Science Library

Mayr, Ernst

2004-01-01

... of evolution is actually five separate theories, each with its own history, trajectory, and impact. Natural selection is a separate idea from common descent, and from geographic speciation, and so on. A number of the perennial Darwinian controversies may well have been caused by the confounding of the five separate theories into a single composite. Tho...

User’s Guide to the SOLAR Semantic Analysis File

Science.gov (United States)

1975-04-30

PERFORMING ORGANIZATION NAME AND ADDRESS System Development Corporation 2500 Colorado Avenue, Santa Monica, Cal. 90406 II. CONTROLLING OFFICE NAME...Dordrecht: D. Pt-Idnir ppT ^üs-eb1!. Ld/ coff , George« (1971) "Tho Hole of Dpduction in 5^»^^ in Studies in IlJliyiStiS 5’JSläüiiES (Gd

Experimental measurement of enthalpy increments of Th0.25Ce0.75O2

International Nuclear Information System (INIS)

Babu, R.; Balakrishnan, S.; Ananthasivan, K.; Nagarajan, K.

2013-01-01

Thorium has been suggested as an alternative fertile material for a nuclear fuel cycle, and an inert matrix for burning plutonium and for waste disposal. The third stage of India's nuclear power programme envisages utilization of thorium and plutonium as a fuel in Advanced Heavy Water Reactor (AHWR) and Accelerator Driven Sub-critical Systems (ADSS). Solid solutions of ThO 2 -PuO 2 are of importance because of coexistence of Th with Pu during the breeding cycle. CeO 2 is used as a PuO 2 analog due to similar ionic radii of cations and similar physico-chemical properties of the oxides. ThO 2 forms a homogeneous solid solution with the cubic fluorite structure when doped with Ce in the entire compositional range. In the development of mixed oxide nuclear fuels, knowledge of thermodynamic properties of thorium oxide and its mixtures has become extremely importance for understanding the fuel behavior during irradiation and for predicting the performance of the fuel under accidental conditions. Thermodynamic functions such as the enthalpy increment and heat capacity of the theria-ceria solid solution have not been measured experimentally. Hence, the enthalpy increments of thoria-ceria solid solutions, Th 0.25 Ce 0.75 O 2 by inverse drop calorimetry in the temperature range 523-1723 K have been measured. The measured enthalpy increments were fitted in to polynomial functions by using the least squares method and the other thermodynamic functions such as heat capacity, entropy and Gibbs energy functions were computed in the temperature range 298-1800 K. The reported thermodynamic functions for Th 0.25 Ce 0.75 O 2 forms the first experimental data and the heat capacity of (Th,Ce)O 2 solid solutions was shown to obey the Neumann-Kopp's rule. (author)

Psicología general

OpenAIRE

Carvajal, Gloria

1997-01-01

introduction. History of psychology. Pre-scientific psychology. Scientific psychology. Schools or psychological power. Action fields of psychology. Nervous system. Central nervous system. Spinal cord. Peripheral nervous system. Process of excitation and inhibition. Psychic spheres of the person. The intellectual life. Volitional life. Emotional life. The personality. Determinants of personality. Maturation of personality. Pathological manifestations of personality. The sensory perception. Tho...

Coenzyme Q10: A New Treatment for Hemorrhagic Shock

Science.gov (United States)

2014-10-29

SUBJECT TERMS hemorrhagic shock, ubiquinol, Coenzyme Q10, patient outcome 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18...o leo& to tboOigllll failure. The < Iota fur AlM •1 ha"’ boon ._...runym.,..,; •• ted in p=en~atlons and publiobed tn Expu""’""" P/u<llology. Tho

Radioactive dinosaur fossil bones of Balasinor area, Kheda district, Gujarat, India

International Nuclear Information System (INIS)

Maithani, P.B.; Rathaiah, Y.V.; Dwivedy, K.K.

1993-01-01

High-thorium (upto 0.4% ThO 2 ) bearing Dinosaur fossil remains are reported from the Infratrappeans of Balasinor area, Kheda district, Gujarat. The thorium enrichment in these fossils is confined to the osseous matter which could be attributed to either isomorphic substitution for Ca 2+ or adsorption and colloidal precipitation on the bone surfaces. (author). 5 refs., 1 fig

Clear up the rule for the exporter (at the Resolution 04/69), whether it is not possible the acquisition at the market abroad

International Nuclear Information System (INIS)

1977-09-01

Define rules for acquisition at the abroad market of the concentrates of uranium chemical compounds. When this impossibility is corroborated by a quarterly consultation, the exporter will have an acquittance after proving the withdrawal, in a special account in the name oc Comissao Nacional De Energia Nuclear (CNEN), and maintain the limit of exception for 0.20 % of ThO 2

Natural radiation in mineral sands deposits in Vietnam and problem of radiological protection

International Nuclear Information System (INIS)

Hung, Bui Van; Duong, Pham Van; Dien, Pham Quang; Quang, Nguyen Hao

1993-01-01

There are about 40 mineral sands deposits located along the Vietnamese coast between Binh Ngoc in the North to Vung Tau in the South of the country. Most of them are being exploited for both, domestic and foreign markets. It has been assessed that the natural gamma background levels over the deposits vary between 0.2 to over 10μGy/h. This wide range indicates that the level of naturally occurring radioactivity in the deposits will warrant its further investigations due to the likelihood of an occurrence of elevated radioactivity levels in mineral processing plants. This paper presents results of the following preliminary investigations: determinations of U and Th concentrations in mineral sands ore samples from several deposits, and determinations of U and Th concentrations in various ilmenite concentrate fractions and secondary separation tailings from Ha Tinh province. The radioactivity levels in the heavy minerals and the labour intensive mineral separation technology currently applied will warrant closer attention to be paid to mineral processing and waste handling in order to improve both, occupational and environmental radiological aspects of the operations. 4 refs., 3 tabs., 1 fig

Microseismic Properties of Typhoons in the Western Pacific

Science.gov (United States)

Xu, Y.; Koper, K. D.; Burlacu, R.

2017-12-01

We analyzed the ambient seismic noise recorded in 2012 by a temporary array of 240 seismometers deployed in Yunnan, China as part of Phase I of the ChinArray project. The stations were installed with a quasi-uniform spacing of about 70 km by the Yunnan Earthquake Administration. Each station consisted of a three-component Guralp-3ESP seismometer and a Reftek 130 data acquisition system with a sampling interval of 0.01 s. To identify the structure and source of the ambient noise, we applied frequency-dependent polarization analysis to the individual stations and f-k analysis for three sub-arrays consisting of 14-25 stations. The most prominent microseismic signals we observed were surface waves generated at periods of 3-7 s by 15 typhoons that occurred in the Western Pacific, mostly during the summer of 2012. The U.S. Navy's Joint Typhoon Warning Center divides a tropical cyclone into four levels, Tropical Depression (TD), Tropical Storm (TS), Typhoon (TY) and Super Typhoon (ST) based on the estimated wind speed. Four of the 15 analyzed typhoons reached ST intensity. The maximum microseism signals tended to last throughout the lifetime of a typhoon. Sometimes, we observed the splitting of a single microseism spectral peak into two parallel peaks. We compared the seismic observations to storm track data for typhoons Guchol, Jelawat, and Son-Tinh, and with oceanic models of wave-wave interaction. We find that microseismic power is correlated with changes in the direction or speed, or both, of the typhoon track. High wind speed or changing wind speed within the typhoon does not have a clear relationship with the microseismic power.

Anomalous uranium concentration in Archaean basement Shear at Dhani Basri and its significance on Southern Margin of Alwar sub-basin, Rajasthan

International Nuclear Information System (INIS)

Panigrahi, B.; Shaji, T.S.; Sharma, G.S.; Yadav, O.P.; Nanda, L.K.

2008-01-01

Prominent shear zones cutting through the basement and cover rocks of Delhi Supergroup have been recognized in Dhani Basri - Ramewala sector of Dausa district, Rajasthan. One such shear zone traversing the granite gneiss (Archaean basement) has been observed at Dhani Basri. The sheared rock is exposed in the form of a small hump and gives appearance of quartzite due to intense silicification. Grab samples collected from the shear zone rock analysed upto 93 ppm U 3 O 8 and <10 ppm ThO 2 , which is anomalous in comparison to unsheared rock which analysed 51 ppm eU 3 O 8 , upto 5 ppm U 3 O 8 and 80 ppm ThO 2 . Gamma-ray logging of boreholes drilled by GSI across this shear zone indicated uranium mineralization of the order of 0.030% eU 3 O 8 x 5.40 m and the primary radioactive mineral has been identified as uraninite. The extension of Dhani Basri shear zone inside the cover rocks of Meso-Proterozoic Delhi Supergroup of rocks of Alwar sub-basin is of paramount importance in locating unconformity related as well as hydrothermal vein type uranium mineralization. (author)

Managing urban water systems with significant adaptation deficits - a unified framework for secondary cities

Science.gov (United States)

Pathirana, A.; Radhakrishnan, M.; Zevenbergen, C.; Quan, N. H.

2016-12-01

The need to address the shortcomings of urban systems - adaptation deficit - and shortcomings in response to climate change - `adaptation gap' - are both major challenges in maintaining the livability and sustainability of cities. However, the adaptation actions defined in terms of type I (addressing adaptation deficits) and type II (addressing adaptation gaps), often compete and conflict each other in the secondary cities of the global south. Extending the concept of the environmental Kuznets curve, this paper argues that a unified framework that calls for synergistic action on type I and type II adaptation is essential in order for these cities to maintain their livability, sustainability and resilience facing extreme rates of urbanization and rapid onset of climate change. The proposed framework has been demonstrated in Can Tho, Vietnam, where there are significant adaptation deficits due to rapid urbanisation and adaptation gaps due to climate change and socio-economic changes. The analysis in Can Tho reveals the lack of integration between type I and type II measures that could be overcome by closer integration between various stakeholders in terms of planning, prioritising and implementing the adaptation measures.

Murine Leukemia Virus Uses TREX Components for Efficient Nuclear Export of Unspliced Viral Transcripts

Directory of Open Access Journals (Sweden)

Toshie Sakuma

2014-03-01

Full Text Available Previously we reported that nuclear export of both unspliced and spliced murine leukemia virus (MLV transcripts depends on the nuclear export factor (NXF1 pathway. Although the mRNA export complex TREX, which contains Aly/REF, UAP56, and the THO complex, is involved in the NXF1-mediated nuclear export of cellular mRNAs, its contribution to the export of MLV mRNA transcripts remains poorly understood. Here, we studied the involvement of TREX components in the export of MLV transcripts. Depletion of UAP56, but not Aly/REF, reduced the level of both unspliced and spliced viral transcripts in the cytoplasm. Interestingly, depletion of THO components, including THOC5 and THOC7, affected only unspliced viral transcripts in the cytoplasm. Moreover, the RNA immunoprecipitation assay showed that only the unspliced viral transcript interacted with THOC5. These results imply that MLV requires UAP56, THOC5 and THOC7, in addition to NXF1, for nuclear export of viral transcripts. Given that naturally intronless mRNAs, but not bulk mRNAs, require THOC5 for nuclear export, it is plausible that THOC5 plays a key role in the export of unspliced MLV transcripts.

U. S. Naval Forces, Vietnam Monthly Historical Summary for May 1971

Science.gov (United States)

1971-07-05

Nuoc Mam (fish sauce, Vietnam’s * *- national condiment ). The "pigs and chickens" animal husbandry projects, which are now underway at 49 Naval bases in...Tau LCDR J. J. DOOLEv, 1JSINt SA. GOSFLOT 4 An Thoi LCDR J. G. TONT󈧏 --S’N *SA COSE LOT 5 My Tho LCDR J. McCORMICK , 12N SA 14DU Camr Ranh Bay LT J

The Buffalo Creek Archaeological Project. Volume 1: Background and Testing at 3MS346 and 3CG847 Mississippi and Craighead Counties, Arkansas

Science.gov (United States)

1992-01-01

shagbark hickory ( Carya ovata), and pecan ( Carya illinoensis ). These trees dominate the vegetation on well-drained elevated land such as tho-se areas...strongly acidic soil (Steyermark 1959:95, 120). Chinquapin (Castanea ozarkensis), black or sourgum (Nyssa sylvatica), black hickory ( Carya texana...white oak, mockernut hickory ( Carya tomentosa), black hickory, white hickory ( Carya alba), flowering dogwoo-T-,whiT𔃻eFash(Fraxinus americana

Description of the MHS Health Level 7 Radiology for Public Health Surveillance

Science.gov (United States)

2014-03-01

0704-0188 r Lbhe: r;.. ) ort n:) bur:l ?n fcr ths co:IV..ct\\or of i1lom:tioo is e~t n:~I:M tv £1\\’?ft:)? 1 t"vJrr.err~>~f. )’" ISo ? , irck.K’ r:, tho...records, and outpatient/inpatient pharmacy transactions. Consequently, surveillance methods are largely disease-specific, but this specificity depends

Positron lifetime studies on thorium oxide powders

International Nuclear Information System (INIS)

Upadhyaya, D.D.; Muraleedharan, R.V.; Sharma, B.D.

1982-01-01

Positron lifetime spectra have been studied for ThO 2 powders, calcined at different temperatures and having different particle sizes. Three lifetime components could be resolved, the longest component being of low intensity. An observed strong dependence on the particle size of the annihilation process and the variation of positronium diffusion constant is explained on the basis of defect density variations in these powders. (author)

Oxide particle size distribution from shearing irradiated and unirradiated LWR fuels in Zircaloy and stainless steel cladding: significance for risk assessment

International Nuclear Information System (INIS)

Davis, W. Jr.; West, G.A.; Stacy, R.G.

1979-01-01

Sieve fractionation was performed with oxide particles dislodged during shearing of unirradiated or irradiated fuel bundles or single rods of UO 2 or 96 to 97% ThO 2 --3 to 4% UO 2 . Analyses of these data by nonlinear least-squares techniques demonstrated that the particle size distribution is lognormal. Variables involved in the numerical analyses include lognormal median size, lognormal standard deviation, and shear cut length. Sieve-fractionation data are presented for unirradiated bundles of stainless-steel-clad or Zircaloy-2-clad UO 2 or ThO 2 --UO 2 sheared into lengths from 0.5 to 2.0 in. Data are also presented for irradiated single rods (sheared into lengths of 0.25 to 2.0 in.) of Zircaloy-2-clad UO 2 from BWRs and of Zircaloy-4-clad UO 2 from PWRs. Median particle sizes of UO 2 from shearing irradiated stainless-steel-clad fuel ranged from 103 to 182 μm; particle sizes of ThO 2 --UO 2 , under these same conditions, ranged from 137 to 202 μm. Similarly, median particle sizes of UO 2 from shearing unirradiated Zircaloy-2-clad fuel ranged from 230 to 957 μm. Irradiation levels of fuels from reactors ranged from 9,000 to 28,000 MWd/MTU. In general, particle sizes from shearing these irradiated fuels are larger than those from the unirradiated fuels. In addition, variations in particle size parameters pertaining to samples of a single vendor varied as much as those between different vendors. The fraction of fuel dislodged from the cladding is nearly proportional to the reciprocal of the shear cut length, until the cut length attains some minimum value below which all fuel is dislodged. Particles of fuel are generally elongated with a long-to-short axis ratio usually less than 3. Using parameters of the lognormal distribution deduced from experimental data, realistic estimates can be made of fractions of dislodged fuel having dimensions less than specified values

Feasibility to convert an advanced PWR from UO2 to a mixed U/ThO2 core – Part I: Parametric studies

International Nuclear Information System (INIS)

Maiorino, Jose R.; Stefani, Giovanni Laranjo; Moreira, João M.L.; Rossi, Pedro C.R.; Santos, Thiago A.

2017-01-01

Highlights: • Neutronics calculation using SERPENT code. • Conversion of an advanced PWR from a UO 2 to (U-Th)O 2 core. • AP 1000-advanced PWR. • Parametric studies to define a converted core. • Demonstration of the feasibility to convert the AP 1000 by using mixed uranium thorium oxide fuel with advantages. - Abstract: This work presents the neutronics and thermal hydraulics feasibility to convert the UO 2 core of the Westinghouse AP1000 in a (U-Th)O 2 core by performing a parametric study varying the type of geometry of the pins in fuel elements, using the heterogeneous seed blanket concept and the homogeneous concept. In the parametric study, all geometry and materials for the burnable poison were kept the same as the AP 1000, and the only variable was the fuel pin material, in which we use several mass proportion of uranium and thorium but keeping the enrichment in 235 U, as LEU (20 w/o). The neutronics calculations were made by SERPENT code, and to validate the thermal limits we used a homemade code. The optimization criteria were to maximize the 233 U, and conversion factor, and minimize the plutonium production. The results obtained showed that the homogeneous concept with three different mass proportion zones, the first containing (32% UO 2 -68%ThO 2 ); the second with (24% UO 2 -76% ThO 2 ), and the third with (20% UO 2 -80% ThO 2 ), using 235 U LEU (20 w/o), and corresponding with the 3 enrichment zones of the AP 1000 (4.45 w/o; 3.40 w/o; 2.35 w/o), satisfies the optimization criteria as well as attending all thermal constrain. The concept showed advantages compared with the original UO 2 core, such a lower power density, and keeping the same 18 months of cycle a reduction of B-10 concentration at the soluble poison as well as eliminating in the integral boron poison coated (IFBA).

Occupationally Based Disaster Medicine

Science.gov (United States)

2011-01-01

and thai bener r ’~tI h~ may re~ult from the a signmem of a prcvi- (luslv trained and drillc:d disa ler Lrc::almen l Icam that can Lake uvcr in al l...they wi ll sup >rv ise tho~e teams and are rt’ ~ pon~ible, ill ong wilh (lccupillional he lth personnel, for Ihe a fet y a nd heallh ()f th e tea

FM Quieting Curves and Related Topics

Science.gov (United States)

1977-08-01

Electronics Engineering Group (EEO) is organized as an independent group reorting, directly to -the Comwiander, Air ’Force Conmmunica-r tions Service (WOC...NUMBER N/A 7. AklTHO -() 6. CONTRACT OR GRANT NUMBER(#) /, .C...or.e M./ Kizer/ , ,/A 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT...in vestigial sideband modulation) and are separated from the carrier frequency by a frequency difference equal to the frequency of the baseband

Dinamika Konflik Dan Integrasi Antara Etnis Dayak Dan Etnis Madura (Studi Kasus Di YOGYAKARTA Malang Dan Sampit)

OpenAIRE

Bashori, Khoiruddin; Majid, Abd; Tago, Mahli Zainuddin

2012-01-01

Indonesia is one of the most pluralistic societies in the world consisting of various social groups, ethnics, tribes, languages and religious diversities. However, the social, political, and cultural diversities among people have frequently been resulting conflicts or tensions. Using conflict and integration approach, therefore, this article observes the dynamics relation between ethnic groups, Madura and Dayak ethnic in particular, in certain plural regions in term of ethnic diversities; tho...

A study on the determination of phosphorus in Th-U matrix by a high resolution spectroanalyser (ICP-AES)

International Nuclear Information System (INIS)

Save, Neeta; Kumar, Neeraj; Jaiswal, Rajesh; Ghosh, Seema; Malav, R.K.; Das, D.K.; Prakash, Amrit; Behere, P.G.; Afzal, Mohd

2013-01-01

Phosphorus is present as an impurity in Thoria and constitutes an important chemical specification of the Thoria based fuel. The present paper depicts the importance of determination of phosphorus, which forms an important quality control step during the fabrication of mixed oxide (Th-U)O 2 pellet. A high resolution spectroanalyser using ICP-AES has been used for the determination of Phosphorus in (ThO 2 -3.25%UO 2 ). (author)

Wybrane aspekty metodyczne zastosowań informatyki do zarządzania województwem

OpenAIRE

Poraszka, Tadeusz

1981-01-01

Methodology of designing applications for informatics in state administration organs represents a creative adaptation of experience gained mainly in the course of applying informatics in tho industry. It also takes into account typical conditions and complex nature of management and administration as well as a fact that all activities on the macroeconomic scale carry a much bigger burden of uncertainty than operations on the company's scale. The present trends in desig...

Surface Geometry and Chemistry of Hydrothermally Synthesized Single Crystal Thorium Dioxide

Science.gov (United States)

2015-03-01

Atmospheric Adsorbents ...............61 4.2.3 Heating Changes the Quantity of Charge on the ThO2 Surface ..................63 4.2.4 Humidity ...The Th peaks at 675 K during the heating phase of the 2nd sequence.. .................... 68 29. Adhesion force as a function of relative humidity ...The crystal used in this experiment was grown by hydrothermal growth techniques via spontaneous nucleation . The experiment was conducted on crystal

The spider fauna of Scragh Bog in Co Westmeath, Ireland (Arachnida: Araneae)

OpenAIRE

Helsdingen, van, P.J.

1998-01-01

The spider fauna of Scragh Bog, a quacking bog in Co Westmeath, Ireland, was investigated for the first time. The presence of 53 species could be established, two of which are new to Ireland (Carorita limnaea (Crosby & Bishop), Porrhomma oblitum (O.P.-Cambridge)), while 30 represent new county records [Philodromus aureolus (Clerck), Tibellus maritimus (Meigen), Misumena vatia (Clerck), Oxyptila trux (Blackwall), Neon reticulatus (Blackwall), Sitticus caricis (Westring), Pirata hygrophilus Tho...

Exclusion and election in Udaipur urban space: implications on tourism.

OpenAIRE

Bautès , Nicolas

2007-01-01

This chapter analyzes various spatial aspects of tourism growth in the city of Udaipur in southern Rajasthan (India). It examines the political, social and economic relationship between tourism and territory, in particular the impact of tourism on the city's urban layout, the resulting uneven economic development and its political consequences. It discusses tourism as a social phenomenon encouraging the economic specialization of particular areas and modifying social relationships between tho...

Ionitriding of Weapon Components

Science.gov (United States)

1974-01-01

and documented tho production sequences required for the case- hardening of AISI 4140 and Nitralloy 13514 steels. Determination of processina...depths were established experimentally for Nitralloy 135M and for AISI 4140 steels. These steels are commonly used for the manufacture of nitrlded...weapons components. A temperature of 050F, upper limit for lonitrlding, was selected for the Nitralloy 135M to keep treatment times short. Since AISI 4140

The Programs of Japan in the Philippines

Science.gov (United States)

1944-07-29

functions of theI U cii’?rsi:rity in tho follo,:ing way: : ’"The purposo an’d - fanc - tion of th Unive-rsiy o.f ti.e Phil) ippines shall be to provide for...to .. ;i :if Japan co to the P’hilippines very soon tor a, series of genes wv-h.:i t - local- players. The ( loa.ding) teoia is (T" ..:yo. Six - .3

Anticommunism Versus Nonintervention in Latin America

Science.gov (United States)

1966-04-08

insistence of the Latin governments, another conference of American states was called at Chapultepec , near Mexico City, in 1945. There, the principles...overthrown in 195^ by an anti-Communist liberation army led by Colonel Carlos Castillo Armas. Castillo Armas became Provisional President in...contributed to the success of Castillo Armas’ liberation army in bringing about the downfall of tho Arbenz regime. The United States, as the leader

Heats of immersion in the thorium oxide-water system at elevated temperatures

International Nuclear Information System (INIS)

Holmes, H.F.

1976-01-01

The surface properties of ThO 2 were studied by heat of immersion calorimetry at 25 to 200 0 C. Results show that the integral heat of immersion of thorium oxide contains contributions which reflect considerable interaction with several layers of water adjacent to the oxide surface. It would be desirable to know the heat capacity changes which occur in the multilayer adsorption of water on an oxide surface. However, such data are not available and their acquisition would be an extremely difficult task. Structuring (a negative ΔCp) of several layers of water (by increased hydrogen bonding) adjacent to an oxide surface could explain an increase in the heat of immersion as the immersion temperature is increased. The more energetic, heterogeneous, high-surface-area samples are expected to induce more order in the adjacent water layers than the less energetic samples. This interpretation is similar to that offered for the temperature dependence of the heat of solution of the alkali halides

Phase relations and linear thermal expansion of cubic solid solutions in the Th1-xMxO2-x/2 (M=Eu, Gd, Dy) systems

International Nuclear Information System (INIS)

Mathews, M.D.; Ambekar, B.R.; Tyagi, A.K.

2005-01-01

Cell parameters and linear thermal expansion studies of the Th-M oxide systems with general compositions Th 1-x M x O 2-x/2 (M=Eu 3+ , Gd 3+ and Dy 3+ , 0.0= 1.5 in the ThO 2 lattice. The upper solid solubility limits of EuO 1.5 , GdO 1.5 and DyO 1.5 in the ThO 2 lattice under conditions of slow cooling from 1673K are represented as Th 0.50 Eu 0.50 O 1.75 , Th 0.60 Gd 0.40 O 1.80 and Th 0.85 Dy 0.15 O 1.925 , respectively. The linear thermal expansion (293-1123K) of MO 1.5 and their single-phase solid solutions with thoria were investigated by dilatometery. The average linear thermal expansion coefficients (α-bar ) of the compounds decrease on going from EuO 1.5 to DyO 1.5 . The values of α-bar for EuO 1.5 , GdO 1.5 and DyO 1.5 containing solid solutions showed a downward trend as a function of the dopant concentration. The linear thermal expansion (293-1473K) of the solid solutions investigated by high-temperature XRD also showed a similar trend

Study of Pd-Sn/Al{sub 2}O{sub 3} catalysts prepared by an oxide colloidal route; Etude de catalyseurs Pd-Sn/Al{sub 2}O{sub 3} prepares par voie colloidale oxyde

Energy Technology Data Exchange (ETDEWEB)

Verdier, St.

2001-09-01

The oxide colloidal route, developed in the laboratory for mono-metallic catalysts, consists in preparing a metallic oxide hydro-sol which leads to the supported catalyst after deposition onto a support and an activation stage. In this work, this method has been adapted to the preparation of alumina supported bimetallic Pd-Sn catalysts to determine its interest for the control of the properties of the bimetallic phase (size, composition and structure). In the preliminary study concerning tin oxide sols, SnO{sub 2} (size=2,3 nm) and Sn{sub 6}O{sub 4}(OH){sub 4} (size = 25 nm) nano-particles were synthesized by neutralization respectively for tin(IV) and tin(H). The control through the pH of the aggregation of the PdO and SnO{sub 2} particles revealed that increasing oxide solubility promotes integral re-dispersion of the oxide particles. To synthesize oxide bimetallic sols, three strategies were defined. Copolymerization (formation of a mixed oxide nano-sol by cross condensation of both metals) does not lead to a mixed oxide Pd-Sn phase. Surface precipitation (neutralization of the second metal in the presence of the first oxide sol) yields nano-particles of both oxides in close interaction. Adsorption (adsorption of the second metal onto the first oxide sol) significantly occurs when contacting tin with a basic PdO sol (hydrolytic adsorption). The characterization and the assessment of the catalytic properties (selective hydrogenation of buta-1,3-diene) of the catalysts prepared by deposition of oxide bimetallic sols showed that the oxide colloidal route allows the control of the properties of the supported bimetallic phase. Moreover, our results display that both Pd-Sn alloy formation and,aggregation of the metallic particles contribute to increase the selectivity for this reaction. (author)

ANALISIS EFEK KECELAKAAN WATER INGRESS TERHADAP REAKTIVITAS DOPPLER TERAS RGTT200K

Directory of Open Access Journals (Sweden)

Zuhair Zuhair

2015-03-01

melekat dengan cara pasif. Kata kunci: Water ingress, reaktivitas Doppler, RGTT200K   In high temperature reactor, the negative temperature reactivity coefficient guarantees fission reaction in the core remain under the control and decay heat will not melt the fuel which cause the release of radioactive substances into the environment. But the entry of water (water ingress into the reactor core due to rupture of a steam generator tube heat exchanger, which is known as one of the design basis accidents, can introduce positive reactivity with other potential hazards such as graphite corrosion and damage of the reflector structure material. This paper will investigate the effect of water ingress accident on Doppler reactivity coefficient of RGTT200K core. The capability of the Doppler reactivity coefficient to compensate positive reactivity incurred during water ingress accident will be examined through a series of calculations with MCNPX code and ENDF/B-VII library for fuel temperature changes from 800K to 1800K. Three options of UO2, ThO2/UO2 and PuO2 fuel kernels with three lattice models of fuel pebble in the reactor core was applied for condition of water ingress with water density from 0 to 1000 kg/m3. The results of the calculations show that Doppler reactivity coefficient is negative for the entire fuel options being considered even for a large possibility of water ingress. The effects of water ingress becomes stronger in lattice model with lower packing fraction because more volume available for water entering the reactor core. The effect of water ingress is also stronger in the uranium core compared to thorium and plutonium cores as a consequence of the Doppler phenomenon where the neutron absorption in resonance region of 238U is greater than 232Th and 240Pu. It can be concluded overall that Doppler coefficient of RGTT200K core has capability to compensate the reactivity insertion introduced by water ingress accident. RGTT200K core with UO2, ThO2/UO2 and PuO2

Libraries: A Vision for the 90’s and Beyond. Proceedings of the Military Librarians Workshop (34th Annual), October 9-12, 1990

Science.gov (United States)

1991-01-08

University, is such a system. MDX diagnoses tho existence and cause of the liver syndrome known as "cholestasis." It banieo Its diagnosis on patient history...and Gretchen Cheung. Nonvoting members present were: Marcia Hanna and Paul Klinefelter . Also present were: Gary Walter, Kathryn Marshall, James Byrn... Klinefelter who is optimistic that the project can be renlized. All past Hosts of MLW should be contacted for their memoirs. It was hoped to publish

Separation of Protactinium from Neutron Irradiated Thorium Oxide

International Nuclear Information System (INIS)

Dominguez, G.; Gutierrez, L.; Ropero, M.

1983-01-01

The chemical separation of thorium and protactinium can be carried out by leaching most of the last one, about 95%, with aqueous HF from neutron irradiated thorium oxide. This leaching reaction la highly favored by the transformation reaction of the ThO 2 material into ThF 4 . For both reactions, leaching and transformation, the reagents concentration, agitation speed and temperature influences were studied and the activation energies were found. (Author) 18 refs

Electronic Transfer of Information and Its Impact on Aerospace and Defence Research and Development Held in the Technical Information Panel Specialists’ Meeting, Brussels, Belgium on 17-19 October 1989

Science.gov (United States)

1990-03-01

with 33,0(100 emiployees, at turnover of 28 billion French Francs, atid involvcd in the production of Concorde, Airbus and Ariane. A number of...nco or orntia~blo magnoto-opticai disco has boen announced by market obsevrvers as an areai of conaiderable growth over tho -4oxt five yearti. Among...frangaise. Ses produits et sos Etudes sont parfaitement connus. On pout citer pour e~n~oire Concorde, Airbus pour les avions, Gazelle, Dauphin pour

Direct determination of beryllium, cadmium, lithium, lead and silver in thorium nitrate solution by electrothermal atomization atomic absorption spectrometry

International Nuclear Information System (INIS)

Thulasidas, S.K.; Kulkarni, M.J.; Porwal, N.K.; Page, A.G.; Sastry, M.D.

1988-01-01

An electrothermal atomization atomic absorption spectrometric (ET-AAS) method is developed for the direct determination of Ag, Be, Cd, Li and Pb in thorium nitrate solution. The method offers detection of sub-nanogram amounts of these analytes in 100-microgram thorium samples with a precision of around 10%. A number of spiked samples and pre-analyzed ThO 2 samples have been analyzed to evaluate the performance of the analytical methods developed here

An evaluation of fast reactor blankets

International Nuclear Information System (INIS)

Oosterkamp, W.J.

1974-01-01

A comparative study of different types of fast reactor radial blankets is presented. Included are blankets of fertile material UO 2 , THO 2 and Th-metal blankets of pure reflectors C, BeO, Ni and combinations of reflecting and fertile blankets. The results for 1000MWe cores indicate that there is no incentive to use other than fertile blankets. The most favorable fertile material is thorium due to the prospective higher price of U-233

A Study of Strategic Lessons Learned in Vietnam. Volume 8. Results of the War

Science.gov (United States)

1980-05-09

BDNI CORPORATION Political Bureau Membeirs (Fourth Party Congress ranking order) Le Duan fruong Chinh Phamn Van Dong Phamn Huna Le Duc Tho Vo Nguyen...the Laotian monarchy was abolished and the Democratic People’s Republic of Laos established. In a political trans - formation which passed with little...Strategic Studies, thus observed, " in the particular case of Vietnam, the general effect was to inaugurate a tran - sitional phase of Americao policy which

Afghanistan: A War That Can Only Be Won via the Concentration of United States Elements of National Power

Science.gov (United States)

2008-04-04

Genocidal Murder 30 - if the enemy has an agreement with Muslims, and the enemy violates that agreement, non-combatants may be killed to make an...this problem “that would fit inside the diplomatic framework of nominal Laotian and Cambodian neutrality, however one-sided that neutrality may be...Better War, 200-214; Shaw, Cambodian Campaign, 153-170; Tho, Cambodian Incursion, 171- 175; Clarke, Final Years, 418-425. 12 Thomas A. Bruscino, Jr, “Out

Effects of Single Dose Energy Drink on QT and P-Wave Dispersion

OpenAIRE

Arınç, Hüseyin; Sarli, Bahadir; Baktir, Ahmet Oguz; Yolcu, Mustafa; Ozyildirim, Serhan; Kayardi, Mahmut; Cosgun, Mehmet; Erguzel, Nuri; Gunduz, Huseyin; Uyan, Cihangir

2013-01-01

Objective: Aim of this study is to evaluate the cardiac electrophysiological effects of energy drink (Red Bull) on QT and P duration and dispersion on surface electrocardiogram.Methods: Twenty healthy volunteers older than 17 years of age were included the study. Subjects with a cardiac rhythm except sinus rhythm, history of atrial or ventricular arrhythmia, family history of premature sudden cardiac death, palpitations, T-wave abnormalities, QTc interval greater than 440 milliseconds, or tho...

The Thoc1 Ribonucleoprotein as a Novel Biomarker for Prostate Cancer Treatment Assignment

Science.gov (United States)

2017-10-01

for prostate cancer , the work may impact development of diagnostic /prognostic products based on pThoc1. The presence of the THO ribonucleoprotin...AWARD NUMBER: W81XWH-14-1-0475 TITLE: The Thoc1 Ribonucleoprotein as a Novel Biomarker for Prostate Cancer Treatment Assignment PRINCIPAL...15Sept 2016 - 14Sep2017 4. TITLE AND SUBTITLE The Thoc1 Ribonucleoprotein as a Novel Biomarker for Prostate 5a. CONTRACT NUMBER Cancer Treatment

Inheritance and the Dynamics of Party Identification

OpenAIRE

Kroh, Martin; Selb, Peter

2009-01-01

Extensive research efforts notwithstanding, scholars continue to disagree on the nature and meaning of party identification. Traditionalists conceive of partisanship as a largely affective attachment to a political party that emerges in childhood through parental influences and tends to persist throughout life. The revisionist conception of partisanship is that of a running tally of party utilities that is updated based on current party performance. We attempt to reconcile both schools of tho...

A big measurement of a small moment

Science.gov (United States)

E Sauer, B.; Devlin, J. A.; Rabey, I. M.

2017-07-01

A beam of ThO molecules has been used to make the most precise measurement of the electron’s electric dipole moment (EDM) to date. In their recent paper, the ACME collaboration set out in detail their experimental and data analysis techniques. In a tour-de-force, they explain the many ways in which their apparatus can produce a signal which mimics the EDM and show how these systematic effects are measured and controlled.

Description of the MHS Health Level 7 Microbiology Laboratory for Public Health Surveillance

Science.gov (United States)

2012-10-01

co:IV..ct\\or of i1lom:tioo is e~t n:~I:M tv £1\\’?ft:)? 1 t"vJrr.err~>~f. )’" ISo ? , irck.K’ r:, tho? tir? for r.,.,\\1"’~’· 1:) instr J-:1 :11s, so?er...activities at the request of the DODGEIS. The HL7 data source includes records from anatomic pathology, chemistry, microbiology, pharmacy , and radiology

AHP 2A: China's na53 mʑi 53 Tibetans: Life, Language and Folklore

Directory of Open Access Journals (Sweden)

Libu Lakhi (Li Jianfu 李建富, Dawa Tenzin ཟླ་བ་བསྟན་འཛིན།

2009-06-01

Full Text Available This remarkable book is the product of a fruitful collaboration among a native speaker of na53 mʑi53 kha11 tho11, Tibetan and Chinese consultants, and a dedicated group of Westerners resident in China. It affords the reader an intimate glimpse into traditional na53 mʑi53 life, now well on its way to disappearing along with hundreds of similar minority cultures in the world.

AHP 2B: China's na53 mʑi 53 Tibetans: Life, Language and Folklore

Directory of Open Access Journals (Sweden)

Libu Lakhi (Li Jianfu 李建富, Dawa Tenzin ཟླ་བ་བསྟན་འཛིན།

2009-06-01

Full Text Available This remarkable book is the product of a fruitful collaboration among a native speaker of na53 mʑi53 kha11 tho11, Tibetan and Chinese consultants, and a dedicated group of Westerners resident in China. It affords the reader an intimate glimpse into traditional na53 mʑi53 life, now well on its way to disappearing along with hundreds of similar minority cultures in the world.

Final Environmental Impact Statement. Permit Application by United States Steel Corp., Proposed Lake Front Steel Mill, Conneaut, OH. Volume 4

Science.gov (United States)

1979-01-01

aditin t fis an g.alim" sbl Case n limitatiom he the kind of air that is %bon all talks began regarding building of a mill in Comact, it was my peesaomly...all.. determination of relative bpp -PlC 12 w eies thO f feSW~ d U Ifom a t peroje c am~r . Luh e r r s i a e a o as- itioc. levels for *an bird species

The resonance absorption controlled reactor

Energy Technology Data Exchange (ETDEWEB)

Caro, R

1977-07-01

In this report a new method of reactor control based on tho isotopic moderator composition variation is studied, taking as a reference a D{sub 2}O/H{sub 2}O system. With this method an spectacular increment in the burn-up degree and a sensible reduction of the conventional control system is obtained. An important part of this work has been the detailed analysis of the parameters affecting the neutron spectrum in a heterogeneous reactor. (Author) 50 refs.

Supersonic flow with shock waves. Monte-Carlo calculations for low density plasma. I

International Nuclear Information System (INIS)

Almenara, E.; Hidalgo, M.; Saviron, J. M.

1980-01-01

This Report gives preliminary information about a Monte Carlo procedure to simulate supersonic flow past a body of a low density plasma in the transition regime. A computer program has been written for a UNIVAC 1108 machine to account for a plasma composed by neutral molecules and positive and negative ions. Different and rather general body geometries can be analyzed. Special attention is played to tho detached shock waves growth In front of the body. (Author) 30 refs

Rapid non-destructive quantitative estimation of urania/ thoria in mixed thorium uranium di-oxide pellets by high-resolution gamma-ray spectrometry

International Nuclear Information System (INIS)

Shriwastwa, B.B.; Kumar, Anil; Raghunath, B.; Nair, M.R.; Abani, M.C.; Ramachandran, R.; Majumdar, S.; Ghosh, J.K.

2001-01-01

A non-destructive technique using high-resolution gamma-ray spectrometry has been standardised for quantitative estimation of uranium/thorium in mixed (ThO 2 -UO 2 ) fuel pellets of varying composition. Four gamma energies were selected; two each from the uranium and thorium series and the time of counting has been optimised. This technique can be used for rapid estimation of U/Th percentage in a large number of mixed fuel pellets from a production campaign

Quantifying Risk in Epidemiological and Ecological Contexts

OpenAIRE

Sellman, Stefan

2018-01-01

The rates of globalization and growth of the human population puts ever increasing pressure on the agricultural sector to intensify and grow more complex, and with this intensification comes an increased risk of outbreaks of infectious livestock diseases. At the same time, and for the same reasons, the detrimental effect that humans have on other species with which we share the environment has never been more apparent, as the current rates of species loss from ecological communities rival tho...

The resonance absorption controlled reactor

International Nuclear Information System (INIS)

Caro, R.

1977-01-01

In this report a new method of reactor control based on tho isotopic moderator composition variation is studied, taking as a reference a D 2 O/H 2 O system. With this method an spectacular increment in the burn-up degree and a sensible reduction of the conventional control system is obtained. An important part of this work has been the detailed analysis of the parameters affecting the neutron spectrum in a heterogeneous reactor. (Author) 50 refs

Determination of low concentrations of thorium in geological materials by X-ray fluorescence

International Nuclear Information System (INIS)

Roca, M.; Bayon, A.

1981-01-01

An X-ray fluorescence method for the determination of thorium in geological samples down to 2 ppm ThO 2 has been developed. To achieve this determination limit an exposed area of the sample 42.5 mm in diameter is used, working with a molybdenum target tube operated at 90 kV and 30 m A. Corrections for background and line interference of the Rb Kα radiation have been carefully considered and empirical correction coefficients calculated. (Author) 3 refs

The Asia-Pacific: A Region in Transition

Science.gov (United States)

2004-01-01

after drawn-out discussions to do with the positions of such eminences as Le Duc Tho and Truong Chinh following the death of old-guard leader Le Duan in...in regional social capital as shown in interstate and trans -state relationships. The Indo-Pakistani rivalry has been at the center of the depletion...dialogues will mean for the region’s existing ‘alphabet soup’ of trans -Pacific institutions. This means not only APEC and the ARF but also ASEAN

Air filled porosity in composting processes

Energy Technology Data Exchange (ETDEWEB)

Ruggieri, L.; Gea, T.; Artola, A.; Sanchez, A.

2009-07-01

As it is widely known, the composting process consists in the aerobic decomposition of the biodegradable organic matter present in different types of solid wastes. Water and oxygen are necessary for the biological activity of microorganisms involved in the composting process and their availability is directly related to the total and the air filled porosity (AFP). Maintaining adequate AFP level satisfies the oxygen content requirement to achieve the desired composting conditions and thus, tho enhance biological activity. (Author)

The Play’s the Thing: Practicing Play as Community Foundation and Design Technique

OpenAIRE

Fullerton, Tracy

2005-01-01

THEME: Interdisciplinary: Changing Views It is generally understood that game development is a collaborative art – requiring and benefiting from the talents of individuals from disperse disciplines and backgrounds. In a professional setting, these individuals may or may not find ways to communicate effectively, depending on the size of the team and the strength of its leadership. But in the end, they are generally employed under the assumption that they can and will find their way amongst tho...

Designing a Secure E-commerce with Credential Purpose-based Access Control

OpenAIRE

Norjihan Abdul Ghani; Harihodin Selamat; Zailani Mohamed Sidek

2014-01-01

The rapid growth of e-commerce has created a great opportunities for both businesses and end users. The essential e-commerce process is required for the successful operation and management of e-commerce activities. One of the processes is access control and security. E-commerce must establish a secure access between the parties in an e-commerce transaction by authenticating users, authorizing access, and enforcing security features. The e-commerce application must authorize access to only tho...

Air filled porosity in composting processes

International Nuclear Information System (INIS)

Ruggieri, L.; Gea, T.; Artola, A.; Sanchez, A.

2009-01-01

As it is widely known, the composting process consists in the aerobic decomposition of the biodegradable organic matter present in different types of solid wastes. Water and oxygen are necessary for the biological activity of microorganisms involved in the composting process and their availability is directly related to the total and the air filled porosity (AFP). Maintaining adequate AFP level satisfies the oxygen content requirement to achieve the desired composting conditions and thus, tho enhance biological activity. (Author)

1 CRYSTALLOCHEMICAL STUDIES ON DAVIDITE FROM BICHUN ...

Indian Academy of Sciences (India)

28

0.9 - 1.4% Al2O3, and 0.8 - 1.2% SiO2. Further, contents of ThO2 (0.13 - 0.14%), MgO (0.2 - 0.3%), MnO. (0.2%), CaO (0.6), Na2O (0.02%), and water of hydration (0.07 - 0.27%, LOI) are low (Table 2). It is highly radioactive due to high U and subordinate amount of Th contents. Among various trace elements,. Zr (1403 ...

Challenges to United States Tactical Air Force Aircraft Maintenance Personnel: Past, Present and Future

Science.gov (United States)

1991-09-01

study f-ocuses on the most 3 recent changes faced by the TAF rraintenance organization. The last chapter comprares and contrasts the development of... forma - tions. But during the interwar years, both of these missions went into eclipse as doctrinal thinkers established the primacy of bombardment as...i.sninent" (15:4). In response to tho! USAF taskin:g, TAC activated Headquarters Nine- teenth Air force and mr- de it solely reaponsible for planning "for

Supersonic flow with shock waves. Monte-Carlo calculations for low density plasma. I; Flujo supersonico de un plasma con ondas de choque, un metodo de montecarlo para plasmas de baja densidad, I.

Energy Technology Data Exchange (ETDEWEB)

Almenara, E; Hidalgo, M; Saviron, J M

1980-07-01

This Report gives preliminary information about a Monte Carlo procedure to simulate supersonic flow past a body of a low density plasma in the transition regime. A computer program has been written for a UNIVAC 1108 machine to account for a plasma composed by neutral molecules and positive and negative ions. Different and rather general body geometries can be analyzed. Special attention is played to tho detached shock waves growth In front of the body. (Author) 30 refs.

"A Time of Great Tension": Memory and the Malaysian Chinese Construction of the May 13 Race Riots

OpenAIRE

Jones, Kelly

2014-01-01

On May 13th 1969, decades of political and ethnic pressures exploded after a contentious general election, changing Malaysia's capital city of Kuala Lumpur from a bustling cityscape into a racialized battleground. Majority Malay and minority Chinese would clash for weeks afterward, leaving behind an estimated two hundred dead and a further five hundred wounded. This paper examines a variety of Malaysian Chinese constructions of the race riots in the decades afterward, piecing together the tho...

COMPARATIVE STUDY OF THE THERAPEUTIC EFFICIENCY OF OXITETRACICLINE, IMIDOCARB AND DIMINAzENE, USED IN THE TREATMENT OF EQUINE THOROUGBREED HEMOPARASITES

OpenAIRE

Comerma Steffensen, Simon Gabriel; Arrieta-Mendoza, D.; Morales, A; Viloria, D; Romero, N.; Morales, G.; Kassar, M.

2012-01-01

It presents a comparative study of the therapeutic efficacy of oxytetracycline, imidocarb and diminaze- ne, used in the treatment of equine hemoparasitosis Thoroughbreds. We studied a total of 105 horses, Tho- roughbreds, all under 2 years old, during the quarantine period November to December 2011. They practice a clinical examination, blood samples were taken for a complete blood count and blood smear for disposal of taxon. They were then medicated with single dose intramuscular (IM) as fol...

Application of the neutron gamma method to a study of water seepage under a rice plantation

International Nuclear Information System (INIS)

Puard, M.; Couchat, P.; Moutonnet, P.

1980-01-01

In order to determine the share of percolation in the pollution by pesticides (particularly Lindane) being carried down in the drainage water of rice plantations, an application of the neutron gamma method under rice cultivation in the Camargue is suggested. A preliminary laboratory study enabled a comparison to be made between deuteriated water (DHO) and tritiated water (THO) used as water tracers in the determination of the dispersive phenomena and retention in a column of saturated soil [fr

Recruitment of TREX to the transcription machinery by its direct binding to the phospho-CTD of RNA polymerase II.

Directory of Open Access Journals (Sweden)

Dominik M Meinel

2013-11-01

Full Text Available Messenger RNA (mRNA synthesis and export are tightly linked, but the molecular mechanisms of this coupling are largely unknown. In Saccharomyces cerevisiae, the conserved TREX complex couples transcription to mRNA export and mediates mRNP formation. Here, we show that TREX is recruited to the transcription machinery by direct interaction of its subcomplex THO with the serine 2-serine 5 (S2/S5 diphosphorylated CTD of RNA polymerase II. S2 and/or tyrosine 1 (Y1 phosphorylation of the CTD is required for TREX occupancy in vivo, establishing a second interaction platform necessary for TREX recruitment in addition to RNA. Genome-wide analyses show that the occupancy of THO and the TREX components Sub2 and Yra1 increases from the 5' to the 3' end of the gene in accordance with the CTD S2 phosphorylation pattern. Importantly, in a mutant strain, in which TREX is recruited to genes but does not increase towards the 3' end, the expression of long transcripts is specifically impaired. Thus, we show for the first time that a 5'-3' increase of a protein complex is essential for correct expression of the genome. In summary, we provide insight into how the phospho-code of the CTD directs mRNP formation and export through TREX recruitment.

Recruitment of TREX to the transcription machinery by its direct binding to the phospho-CTD of RNA polymerase II.

Science.gov (United States)

Meinel, Dominik M; Burkert-Kautzsch, Cornelia; Kieser, Anja; O'Duibhir, Eoghan; Siebert, Matthias; Mayer, Andreas; Cramer, Patrick; Söding, Johannes; Holstege, Frank C P; Sträßer, Katja

2013-11-01

Messenger RNA (mRNA) synthesis and export are tightly linked, but the molecular mechanisms of this coupling are largely unknown. In Saccharomyces cerevisiae, the conserved TREX complex couples transcription to mRNA export and mediates mRNP formation. Here, we show that TREX is recruited to the transcription machinery by direct interaction of its subcomplex THO with the serine 2-serine 5 (S2/S5) diphosphorylated CTD of RNA polymerase II. S2 and/or tyrosine 1 (Y1) phosphorylation of the CTD is required for TREX occupancy in vivo, establishing a second interaction platform necessary for TREX recruitment in addition to RNA. Genome-wide analyses show that the occupancy of THO and the TREX components Sub2 and Yra1 increases from the 5' to the 3' end of the gene in accordance with the CTD S2 phosphorylation pattern. Importantly, in a mutant strain, in which TREX is recruited to genes but does not increase towards the 3' end, the expression of long transcripts is specifically impaired. Thus, we show for the first time that a 5'-3' increase of a protein complex is essential for correct expression of the genome. In summary, we provide insight into how the phospho-code of the CTD directs mRNP formation and export through TREX recruitment.

Remedial action plan and site design for stabilization of the inactive uranium mill tailings sites at Rifle, Colorado: Final report

International Nuclear Information System (INIS)

1990-02-01

This radiologic characterization of tho two inactive uranium millsites at Rifle, Colorado, was conducted by Bendix Field Engineering Corporation (Bendix) for the US Department of Energy (DOE), Grand Junction Projects Office, in accord with a Statement of Work prepared by the DOE Uranium Mill Tailings Remedial Action (UMTRA) Project Technical Assistance Contractor, Jacobs Engineering Group, Inc. (Jacobs). The purpose of this project is to define the extent of radioactive contamination at the Rifle sites that exceeds US Environmental Protection Agency, (EPA) standards for UMTRA sites. The data presented in this report are required for characterization of the areas adjacent to the tailings piles and for the subsequent design of cleanup activities. An orientation visit to the study area was conducted on 31 July--1 August 1984, in conjunction with Jacobs, to determine the approximate extent of contaminated area surrounding tho piles. During that visit, survey control points were located and baselines were defined from which survey grids would later be established; drilling requirements were assessed; and radiologic and geochemical data were collected for use in planning the radiologic fieldwork. The information gained from this visit was used by Jacobs, with cooperation by Bendix, to determine the scope of work required for the radiologic characterization of the Rifle sites. Fieldwork at Rifle was conducted from 1 October through 16 November 1984

Alaska Dental Health Aide Program.

Science.gov (United States)

Shoffstall-Cone, Sarah; Williard, Mary

2013-01-01

In 1999, An Oral Health Survey of American Indian and Alaska Native (AI/AN) Dental Patients found that 79% of 2- to 5-year-olds had a history of tooth decay. The Alaska Native Tribal Health Consortium in collaboration with Alaska's Tribal Health Organizations (THO) developed a new and diverse dental workforce model to address AI/AN oral health disparities. This paper describes the workforce model and some experience to date of the Dental Health Aide (DHA) Initiative that was introduced under the federally sanctioned Community Health Aide Program in Alaska. These new dental team members work with THO dentists and hygienists to provide education, prevention and basic restorative services in a culturally appropriate manner. The DHA Initiative introduced 4 new dental provider types to Alaska: the Primary Dental Health Aide, the Expanded Function Dental Health Aide, the Dental Health Aide Hygienist and the Dental Health Aide Therapist. The scope of practice between the 4 different DHA providers varies vastly along with the required training and education requirements. DHAs are certified, not licensed, providers. Recertification occurs every 2 years and requires the completion of 24 hours of continuing education and continual competency evaluation. Dental Health Aides provide evidence-based prevention programs and dental care that improve access to oral health care and help address well-documented oral health disparities.

Alaska Dental Health Aide Program

Directory of Open Access Journals (Sweden)

Sarah Shoffstall-Cone

2013-08-01

Full Text Available Background. In 1999, An Oral Health Survey of American Indian and Alaska Native (AI/AN Dental Patients found that 79% of 2- to 5-year-olds had a history of tooth decay. The Alaska Native Tribal Health Consortium in collaboration with Alaska’s Tribal Health Organizations (THO developed a new and diverse dental workforce model to address AI/AN oral health disparities. Objectives. This paper describes the workforce model and some experience to date of the Dental Health Aide (DHA Initiative that was introduced under the federally sanctioned Community Health Aide Program in Alaska. These new dental team members work with THO dentists and hygienists to provide education, prevention and basic restorative services in a culturally appropriate manner. Results. The DHA Initiative introduced 4 new dental provider types to Alaska: the Primary Dental Health Aide, the Expanded Function Dental Health Aide, the Dental Health Aide Hygienist and the Dental Health Aide Therapist. The scope of practice between the 4 different DHA providers varies vastly along with the required training and education requirements. DHAs are certified, not licensed, providers. Recertification occurs every 2 years and requires the completion of 24 hours of continuing education and continual competency evaluation. Conclusions. Dental Health Aides provide evidence-based prevention programs and dental care that improve access to oral health care and help address well-documented oral health disparities.

Dynamic Analysis of the Thorium Fuel Cycle in CANDU Reactors

International Nuclear Information System (INIS)

Jeong, Chang Joon; Park, Chang Je

2006-02-01

The thorium fuel recycle scenarios through the Canada deuterium uranium (CANDU) reactor have been analyzed for two types of thorium fuel: homogeneous ThO 2 UO 2 and ThO 2 UO 2 -DUPIC fuels. The recycling is performed through the dry process fuel technology which has a proliferation resistance. For the once-through fuel cycle model, the existing nuclear power plant construction plan was considered up to 2016, while the nuclear demand growth rate from the year 2016 was assumed to be 0%. After setting up the once-through fuel cycle model, the thorium fuel CANDU reactor was modeled to investigate the fuel cycle parameters. In this analysis, the spent fuel inventory as well as the amount of plutonium, minor actinides and fission products of the multiple recycling fuel cycle were estimated and compared to those of the once-through fuel cycle. From the analysis results, it was found that the closed or partially closed thorium fuel cycle can be constructed through the dry process technology. Also, it is known that both the homogeneous and heterogeneous thorium fuel cycles can reduce the SF accumulation and save the natural uranium resource compared with the once-through cycle. From the material balance view point, the heterogeneous thorium fuel cycle seems to be more feasible. It is recommended, however, the economic analysis should be performed in future

Fluid inclusion study of radioactive granite and cherty cataclasite in the Southeastern part of Nanded district, Maharashtra: implications for the uranium mineralisation

International Nuclear Information System (INIS)

Banerjee, Rahul; Shivkumar, K.; Thomas, Tresa; Thomas, Jugina; Pandian, M.S.

2013-01-01

Southeastern part of Nanded district, Maharashtra exposes Palaeoproterozoic granitoids, representing the younger phase of Peninsular Gneissic Complex (PGC), mark the northeastern extension of Eastern Dharwar Craton. These granitoids are predominantly pink/grey granites, which are traversed by younger phosphatic cherty cataclasites close to the Deccan Trap capping. They are also affected by profuse pegmatitic/quartzo-feldspathic, quartz and epidote venations, especially close to fault/shear zones. A number of N-S to NNE-SSW, NE-SW, NW-SE and E-W trending lineaments marked by faults/fractures/shear zones and dykes are delineated in this granitic terrain. Among these, NE-SW and NNE-SSW faults/shear zones affecting granitoids and cherty cataclasites in Shahpur-Sujayatpur and Thadisaoli area have recorded significant uranium anomalies (Granitoids: upto 1% U 3 O 8 and 0.20% ThO 2 ; Cherty cataclasites upto 0.11% U 3 O 8 and <0.005% ThO 2 ) and enrichment in rare metal and rare earth element content (Nb-77ppm, Y-111 ppm, Zr-432ppm; n=9 and total REE-1167ppm; n=3). Presence of discrete uranium/thorium minerals (uraninite, b-uranophane and thorite) and high content of resistates viz., apatite, zircon, allanite, sphene, cerianite, monazite and ilmenite are responsible for radioactivity in granitoids while phosphatic material accounts for radioactivity in cherty cataclasites

Hybrid pellets: an improved concept for fabrication of nuclear fuel

International Nuclear Information System (INIS)

Matthews, R.B.; Hart, P.E.

1979-09-01

The feasibility of fabricating fuel pellets using gel-derived microspheres as press feed was evaluated. By using gel-derived microspheres as press feed, the potential exists for eliminating dusty operations like milling, slugging, and granulation, from the pelleting process. The free-flowing character of the spheres should also result in limited dust generation during powder transport and pressing operations. The results of this study clearly demonstrate that fuel pellets can be successfully fabricated on a laboratory scale using UO 2 gel microspheres as press feed. Under moderate sintering conditions, 1,500 0 C for 4 h in Ar-4% H 2 , UO 2 pellets with densities up to 96% TD were fabricated. A range of pellet microstructures and densities were achieved depending on sphere forming and calcining conditions. Based on these results, a set of necessary sphere properties are suggested: O/U less than 2.20, crystallite size less than 500 A, specific surface area greater than 8 m 2 /g, and sphere size 200 and 400 μm. Preliminary attempts to fabricate ThO 2 and ThO 2 -UO 2 pellets using microspheres were unsuccessful because the requisite sphere properties were not achieved. Areas requiring additional development include: demonstration of the process on scaled-up equipment suitable for use in a remote fuel fabrication facility and evaluation of the irradiation performance of pellet fuels from gel-spheres

Thermophysical and anion diffusion properties of (U x ,Th1-x )O2.

Science.gov (United States)

Cooper, Michael W D; Murphy, Samuel T; Fossati, Paul C M; Rushton, Michael J D; Grimes, Robin W

2014-11-08

Using molecular dynamics, the thermophysical properties of the (U x ,Th 1- x )O 2 system have been investigated between 300 and 3600 K. The thermal dependence of lattice parameter, linear thermal expansion coefficient, enthalpy and specific heat at constant pressure is explained in terms of defect formation and diffusivity on the oxygen sublattice. Vegard's law is approximately observed for solid solution thermal expansion below 2000 K. Different deviations from Vegard's law above this temperature occur owing to the different temperatures at which the solid solutions undergo the superionic transition (2500-3300 K). Similarly, a spike in the specific heat, associated with the superionic transition, occurs at lower temperatures in solid solutions that have a high U content. Correspondingly, oxygen diffusivity is higher in pure UO 2 than in pure ThO 2 . Furthermore, at temperatures below the superionic transition, oxygen mobility is notably higher in solid solutions than in the end members. Enhanced diffusivity is promoted by lower oxygen-defect enthalpies in (U x ,Th 1- x )O 2 solid solutions. Unlike in UO 2 and ThO 2 , there is considerable variety of oxygen vacancy and oxygen interstitial sites in solid solutions generating a wide range of property values. Trends in the defect enthalpies are discussed in terms of composition and the lattice parameter of (U x ,Th 1- x )O 2 .

Thermophysical and anion diffusion properties of (Ux,Th1−x)O2

Science.gov (United States)

Cooper, Michael W. D.; Murphy, Samuel T.; Fossati, Paul C. M.; Rushton, Michael J. D.; Grimes, Robin W.

2014-01-01

Using molecular dynamics, the thermophysical properties of the (Ux,Th1−x)O2 system have been investigated between 300 and 3600 K. The thermal dependence of lattice parameter, linear thermal expansion coefficient, enthalpy and specific heat at constant pressure is explained in terms of defect formation and diffusivity on the oxygen sublattice. Vegard's law is approximately observed for solid solution thermal expansion below 2000 K. Different deviations from Vegard's law above this temperature occur owing to the different temperatures at which the solid solutions undergo the superionic transition (2500–3300 K). Similarly, a spike in the specific heat, associated with the superionic transition, occurs at lower temperatures in solid solutions that have a high U content. Correspondingly, oxygen diffusivity is higher in pure UO2 than in pure ThO2. Furthermore, at temperatures below the superionic transition, oxygen mobility is notably higher in solid solutions than in the end members. Enhanced diffusivity is promoted by lower oxygen-defect enthalpies in (Ux,Th1−x)O2 solid solutions. Unlike in UO2 and ThO2, there is considerable variety of oxygen vacancy and oxygen interstitial sites in solid solutions generating a wide range of property values. Trends in the defect enthalpies are discussed in terms of composition and the lattice parameter of (Ux,Th1−x)O2. PMID:25383028

Dengvaxia®: Prayers Answered or NOT?

OpenAIRE

Deepak Gupta

2016-01-01

Dengvaxia is the first vaccine against dengue that has been developed after decades of toiling to tame the four-strain dengue virus. The questions have already been raised regarding its non-utility for the younger ones and the seronegative population due to ethical concern of non-maleficence (do-no-harm). It is not clear where this leaves the endemic populations suffering for decades from un-resolving morbidity and mortality burdens of dengue fever, and whether this worsens the dilemma of tho...

A tetrapositive metal ion in the gas phase: Thorium(IV) coordinated by neutral tridentate ligands

International Nuclear Information System (INIS)

Gong, Yu; Tian, Guoxin; Rao, Linfeng; Gibson, John K.; Hu, Han-Shi; Li, Jun

2013-01-01

Sheltering thorium ions: A Th 4+ ion supported by three neutral tetramethyl-3-oxaglutaramide ligands (L=TMOGA) is produced in the gas phase by electrospray ionization. The thorium in chiral Th(L) 3 4+ is coordinated by nine oxygen atoms. Quantum chemical studies revealed a decrease in Th-O binding energies and bond orders and an increase in bond lengths, as the number of coordinating ligands increases. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

A tetrapositive metal ion in the gas phase: Thorium(IV) coordinated by neutral tridentate ligands

Energy Technology Data Exchange (ETDEWEB)

Gong, Yu; Tian, Guoxin; Rao, Linfeng; Gibson, John K. [Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Hu, Han-Shi [Department of Chemistry and Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Tsinghua University (China); Li, Jun [Department of Chemistry and Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Tsinghua University (China); William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory (United States)

2013-07-01

Sheltering thorium ions: A Th{sup 4+} ion supported by three neutral tetramethyl-3-oxaglutaramide ligands (L=TMOGA) is produced in the gas phase by electrospray ionization. The thorium in chiral Th(L){sub 3}{sup 4+} is coordinated by nine oxygen atoms. Quantum chemical studies revealed a decrease in Th-O binding energies and bond orders and an increase in bond lengths, as the number of coordinating ligands increases. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Command History. 1967. Volume 1. Sanitized

Science.gov (United States)

1967-01-01

the Politburo of the Lao Dong Party. This top political control center included Le Duan, General Vo Nguyen Glap, Truong Chinh , Le Duc Tho, and until...the support area Naval Support Activity (NSA) Da Nang’s vital intra- coastal trans -shipment route from the deep water port at Da Nang northward to...under the energetic guidance of MG Nguyen Duc Thang, reviewed PAGE 6 OF 1340 PAGES I% the entire process of RD and set to the task of revitalizing the

Essays on Strategy. 5

Science.gov (United States)

1988-01-01

Van Dong, Truong Chinh , To Huu, and Le Duc Tho, but retained and pro- moted to the number two position Pham Hung, the Min- ister of Interior and one...explained that a basic concern of the United States was that the Pacific region Should not be trans - formed "into yet another area of superpower confronta... tran - ,sition to mutual 13Mll) t’apkailities would be frought with uncertainty, instabilitY, and po-,ible peril. ("On.juentlvt. alternative tour vields

Prevalence and Determinants of Falls among Older Adults in Ecuador: An Analysis of the SABE I Survey

OpenAIRE

Orces, Carlos H.

2013-01-01

The present study based on a nationally representative sample of older adults living in the Andes mountains and coastal region of the country indicates that 34.7% of older adults had fallen in the previous year in Ecuador. Among fallers, 30.6% reported a fall-related injury. The prevalence of falls was higher in women and among older adults residing in the rural Andes mountains. In the multivariate model, women, subjects with cognitive impairment, those reporting urinary incontinence, and tho...

Boron Hydrides

Science.gov (United States)

1946-07-01

Insert Class Insert Class 15 SEPT. 1955LSTJ4 ON _ _ By authority of IST #46 1. Month Day Year Specify Authority Being Used This act’.on was...Tio, therefore, suggest that the Naval.Research laboratory furnish us vih such informati,-gn in its possession ,as to vftothn’r octane or cetano num...upn to 33 :,.tmosphoros), hznd a dotrIn.Cntnl effoct on the yield. The hiph Zroesuros incronsod the converaiona but deocrasedl tho yielOd rc1: ist tc

Conventional Prompt Global Strike: Capabilities Today While Planning for Tomorrow

Science.gov (United States)

2012-03-19

I hOu< pet tesponse, ll’ldud;ng tho trno lOt tevio-•,ng instructions, s<>arc/1Jng oxi•tong data sources, gathenng and mai"tain•ng the data needeo...are politically sensitive. 3. The ability to destroy both a traditionally constructed brick and mortar building, and a deeply buried underground...seconds. This technology is setting the foundation for hypersonic application ”17 and could power a hypersonic CPGS delivery vehicle. NASA describes a

A Novel Technique for Split-Thickness Skin Donor Site Pain Control: Subcutaneous Catheters for Continuous Local Anesthetic Infusion

Science.gov (United States)

2012-01-01

the new: a novel approach to treating pain associated with rib fractures . World J Surg 2010;34:2359–62. 3. Wheatley GH III, Rosenbaum DH, Paul MC, et...has been described after laparotomy, tho- racotomy, inguinal hernia repair, and rib fractures .2–4 We describe our experience at the U.S. Army Insti...JAN 2012 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE A novel technique for split-thickness skin donor site pain control

The cloud security ecosystem technical, legal, business and management issues

CERN Document Server

Ko, Ryan

2015-01-01

Drawing upon the expertise of world-renowned researchers and experts, The Cloud Security Ecosystem comprehensively discusses a range of cloud security topics from multi-disciplinary and international perspectives, aligning technical security implementations with the most recent developments in business, legal, and international environments. The book holistically discusses key research and policy advances in cloud security - putting technical and management issues together with an in-depth treaties on a multi-disciplinary and international subject. The book features contributions from key tho

Impacts of dyke development in flood prone areas in the Vietnamese Mekong Delta to downstream flood hazard

Science.gov (United States)

Khanh Triet Nguyen, Van; Dung Nguyen, Viet; Fujii, Hideto; Kummu, Matti; Merz, Bruno; Apel, Heiko

2016-04-01

The Vietnamese Mekong Delta (VMD) plays an important role in food security and socio-economic development of the country. Being a low-lying coastal region, the VMD is particularly susceptible to both riverine and tidal floods, which provide, on (the) one hand, the basis for the rich agricultural production and the livelihood of the people, but on the other hand pose a considerable hazard depending on the severity of the floods. But despite of potentially hazardous flood, the area remain active as a rice granary due to its nutrient-rich soils and sediment input, and dense waterways, canals and the long standing experience of the population living with floods. In response to both farmers' requests and governmental plans, the construction of flood protection infrastructure in the delta progressed rapidly in the last twenty years, notably at areas prone to deep flooding, i.e. the Plain of Reeds (PoR) and Long Xuyen Quadrangle (LXQ). Triple rice cropping becomes possible in farmlands enclosed by "full-dykes", i.e. dykes strong and high enough to prevent flooding of the flood plains for most of the floods. In these protected flood plains rice can be grown even during the peak flood period (September to November). However, little is known about the possibly (and already alleged) negative impacts of this fully flood protection measure to downstream areas. This study aims at quantifying how the flood regime in the lower part of the VMD (e.g. Can Tho, My Thuan, …) has been changed in the last 2 recent "big flood" events of 2000 and 2011 due to the construction of the full-dyke system in the upper part. First, an evaluation of 35 years of daily water level data was performed in order to detect trends at key gauging stations: Kratie: upper boundary of the Delta, Tan Chau and Chau Doc: areas with full-dyke construction, Can Tho and My Thuan: downstream. Results from the Mann-Kendall (MK) test show a decreasing trend of the annual maximum water level at 3 stations Kratie, Tan

Li tho bio chemistratrigraphy in Mina Verdum group Nico Perez terrain-Uruguay

International Nuclear Information System (INIS)

Gaucher, C.; Martinez, G.; Cernuschi, F.; Chiglino, L.; Sial, A.; Poire, D.

2007-01-01

The occurrence of volcanic and pyroclastic rocks in the Mina Verdun Group is reported here. The unit represents a marine volcanosedimentary succession, made up from base to top of the following formations: Cerro de las Viboras Formation (metarhyolites), Don Mario Formation (pelites, sandstones), La Toma Formation (marls), El Calabozo Formation (stromatolitic limestones with Conophyton), Gibraltar Formation (mainly dolostones, subordinate marls and limestones) and Nueva Carrara Formation (acid lapilli-tuffs acidos and dolomitic metamarls). Three outcrop areas are known, located between Minas and Pan de Azucar, namely: Mina Verdun (stratotype), Burgueno Quarry and Paso del Molino (Arroyo Pan de Azucar). Diamictites and orthoconglomerates of the Las Ventanas Formation overly with erosional and angular unconformity the Mina Verdun Group. The age of the succession is pre-Ediacaran, and bracketed between the late Mesoproterozoic and Tonian (1300-850 Ma) according to the chemostratigraphic data and the stromatolite assemblages. Carbonates of the Mina Verdun Group show a ?13C curve at its stratotype, which is characterized by a basal negative excursion to -3.3 PDB, followed by moderately positive values in the rest of the section, representing a plateau around +2 ? PDB. In the southern part of its outcrop area, limestones of the Mina Verdun Group show more negative de ?13C and ?18O values, as well as a maniphest decoloration. These characteristics are the result of contact-metamorphism of nearby granitic plutons in that area. (author)

Electronic and Physical Characterization of Hydrothermally Grown Single Crystal ThO2

Science.gov (United States)

2013-12-26

uses ultra- violet photons as the excitation source. The tentative photon range for a UV source is 0.01 to 1.0 keV. Referring to Figure 7, the mean...the reverse process; the initial and final states are reversed. The initial state for this spectro - scopic technique is a low energy electron. The...photoemission. The improved energy resolution is a result of the narrow excitation line shape for the UPS source. In many cases, the FWHM of a UV source may

The Complex Sol-Gel Process for producing small ThO2 microspheres

Science.gov (United States)

Brykala, Marcin; Rogowski, Marcin

2016-05-01

Thorium based fuels offer several benefits compared to uranium based fuels thus they might be an attractive alternative to conventional fuel types. This study is devoted to the synthesis and the characterization of small thorium dioxide microspheres (Ø solution the solid thorium nitrate was dissolved and partially neutralized by aqueous ammonia under pH control. The microspheres of thorium-ascorbate gel were obtained using the ICHTJ Process (INCT in English). Studies allowed to determine an optimal heat treatment with calcination temperature of 700 °C and temperature rate not higher than 2 °C/min which enabled us to obtain a crack-free surface of microspheres. The main parameters which have a strong influence on the synthesis method and features of the spherical particles of thorium dioxide are described in this article.

Crystal chemistry and thermal behavior of La doped (U, Th)O2

Science.gov (United States)

Keskar, Meera; Shelke, Geeta P.; Shafeeq, Muhammed; Krishnan, K.; Sali, S. K.; Kannan, S.

2017-12-01

X-ray diffraction, chemical and thermal studies of [(U0.2Th0.8)1-yLay]O2+x (LUTL) and [(U0.3Th0.7)1-yLay]O2+x (UTL); compounds (where y ≤ 0.4) were carried out. These compounds were synthesized by gel combustion method followed by heating in reduced atmospheres at 1673 K. To co-relate lattice parameters with metal and oxygen concentrations, reduced oxides were heated in Ar, CO2 and air atmospheres. Retention of FCC phase was confirmed in all mixed oxides with y ≤ 0.4. The cubic lattice parameters could be expressed in a linear equation of x and y as: a (Ǻ) = 5.5709 - 0.187 x + 0.032 y; [x Oxidation studies and simple ionic model calculations suggested that uranium is predominantly present as a mixture of +5 and + 6 states when La/U ratio ∼2. Oxidation kinetics of mixed oxides was studied by non-isothermal method using thermogravimetry and was found to be a diffusion controlled reaction. High temperature X-ray diffraction studies of LUTL and UTL mixed oxides showed positive thermal expansion in the temperature range of 298-1273 K and % expansion increases with La concentration.

Vacuum tight sodium resistant compound between ThO2 ceramic and metal

International Nuclear Information System (INIS)

Reetz, T.

A method for evaluating the mechanical tensions for metal/ ceramic joinings was applied to the selection of metal components for a highly vacuum tight, sodium-resistant metal/ThO 2 ceramic solder joining. The metal component selected was the iron--nickel alloy Dilasil which is joined to the ceramic using a nickel-based solder. The wetting of the cearamic could be carried out using the titanium hydride technique or after the formation of a W-cerium layer on the surface of this ceramic. (U.S.)

Characteristics of Tacca leontopetaloides L. Kuntze collected from An Giang in Vietnam

Science.gov (United States)

Vu, Quan Thi Hong; Le, Phung Thi Kim; Vo, Huy Pham Hoang; Nguyen, Triet Thanh; Nguyen, Tam Kim Minh

2017-09-01

Tacca leontopetaloides L. Kuntze has been known as a remedy in folk medicine and also a staple food source in many tropical countries. Nonetheless, there are currently few literature and research on the potential pharmaceutical benefits of this herbal plant. In this study, the constituents of leaves, peels and peeled tubers as well as its antioxidant and antimicrobial activities of Tacca cultivated from mountainous regions in Tinh Bien, An Giang Province, Vietnam were investigated. The results indicated that the highest of total phenolic content (TPC) and total flavonoid content (TFC) were presented in leaves of Tacca which were 16.69 mg GAE (gallic acid equivalent)/g dried weight, 57.24 mg QE (quercetin equivalent)/g dried weight, respectively. Besides, the yield of flour recovery process from Tacca tuber estimated from 18%-20%. The chemical compositions of Tacca flour were 0.66 % total of nitrogen, 0.91% lipid, 0.05% ash and 85.7% starch content on dried weight. Furthermore, the extract of peels possessed potential antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis whilst the extract of others did not show any significant inhibition at the same concentration. As a results, with high starch content (nearly 20% in tuber) is a highly promising new starch for food and pharmaceutical excipient industry, while the usefullness of peel in treatment need further investigation.

Unidentified Aerial and Celestial Objects. Appendix B

Science.gov (United States)

1949-04-30

i:Aterial submitted relative to i..aidant jflQl) that the observation was made at 3«o0 ?« .:. allows for no ^ossi’jle astrono .-ical ex...3 aepteniber iy47 ?hie Lnoid*nt doe» not have an astrono .’ioal explanation. ~.e« re orl or. inoidtmt f61« ! r —\\ •T-j.-i...the faot that no s...o:-:e trail was indicated, tactics of the object preclude tho possibility o£ its having been astrono ::.ical; ::ietsors do not

Tris(tetrabutylammonium) tris(nitrato-κ2 O,O ')tetrakis(thiocyanato-κN)thorium(IV)

International Nuclear Information System (INIS)

Janeth Lozano-Rodriguez, M.; Petit, S.; Copping, R.; Den Auwer, Ch.; Janeth Lozano-Rodriguez, M.; Mustre de Leon, J.; Thuery, P.

2011-01-01

The title compound, (C 16 H 36 N) 3 [Th(NCS) 4 (NO 3 ) 3 ], was obtained from the reaction of Th(NO 3 ) 4 .5H 2 O with (Bu 4 N)(NCS). The Th(IV) atom is in a ten-coordinate environment of irregular geometry, being bound to the N atoms of the four thiocyanate ions and to three bidentate nitrate ions. The average Th-N and Th-O bond lengths are 2.481 (10) and 2.57 (3) Angstroms, respectively. (authors)

Determination of low concentrations of pyridine in piperidine by gas chromatography and infrared spectroscopy; Determinacion de bajas concentraciones de piperidina en piridina por cromatografia de gases y espectroscopia infrarroja

Energy Technology Data Exchange (ETDEWEB)

Perez Garcia, M. M.; Parellada Bellod, R.

1979-07-01

This paper describes the determination of low amounts of piperidine in pyridine in the concentration range of 0-5%. After an exhausting review of the bibliography on the column selection, the chromatographic separation and determination are made on the following column: 27% Pennwalt- 223; 4% KOH on Gas-Chrom R; 80-100 mesh with flame ionization detector. The retention indexes of both compounds and tho Rohrschneider constants of the phase used are calculated. The minimum detection limit achieved for piperidine is 0,25%. (Author) 25 refs.

Determination of low concentrations of pyridine in piperidine by gas chromatography and infrared spectroscopy

International Nuclear Information System (INIS)

Perez Garcia, M. M.; Parellada Bellod, R.

1979-01-01

This paper describes the determination of low amounts of piperidine in pyridine in the concentration range of 0-5%. After an exhausting review of the bibliography on the column selection, the chromatographic separation and determination are made on the following column: 27% Pennwalt- 223; 4% KOH on Gas-Chrom R; 80-100 mesh with flame ionization detector. The retention indexes of both compounds and tho Rohrschneider constants of the phase used are calculated. The minimum detection limit achieved for piperidine is 0,25%. (Author) 25 refs

Proceedings of the Conference on the Design of Experiments in Army Research Development and Testing (20th). Held at Army Operational Test and Evaluation Agency and Army Engineer Center at Fort Belvoir, VA., on 23-25 October 1974. Part 1

Science.gov (United States)

1975-06-01

more about t h i s i n a few moments. "Jack" Youden had r ece ived h i s Ph.D. i n Chemistry from Columbia i n 1924, was a Phys i ca l...xx xx (, Final, &port on tho Evaluation of a Semiautomatic Flight Operations Center Army Tactical A i r Space Regulation Systcm ( ATARS ) a...consultant the the Office of Air Pollution. He was Chairman of the Gordon Conference on Statietics in Chemistry and Chemical Engineering in 1954, and

Radiogenic heavy minerals in Brazilian beach sand

International Nuclear Information System (INIS)

Malanca, A.

1998-01-01

Sand samples collected on the beaches of the 'radioactive' Brazilian town of Guarapari were first separated by flotation in bromoform and successively divided into various magnetic fractions with a Franz isodynamic separator. concentrations of background radionuclides in samples of monazite, ilmenite, and zircon were determined by a γ-ray spectrometer. Chemical composition of monazite, ilmenite and magnetite were assessed by means of an electron microprobe. Monazite resulted to be relatively rich in ThO 2 whose abundance ranged from 5.3 to 7.7 (wt%). (author)

Interactions between mRNA export commitment, 3'-end quality control, and nuclear degradation

DEFF Research Database (Denmark)

Libri, Domenico; Dower, Ken; Boulay, Jocelyne

2002-01-01

Several aspects of eukaryotic mRNA processing are linked to transcription. In Saccharomyces cerevisiae, overexpression of the mRNA export factor Sub2p suppresses the growth defect of hpr1 null cells, yet the protein Hpr1p and the associated THO protein complex are implicated in transcriptional el...... results show that several classes of defective RNPs are subject to a quality control step that impedes release from transcription site foci and suggest that suboptimal messenger ribonucleoprotein assembly leads to RNA degradation by Rrp6p....

Development of new VNTR markers for pike and assessment of variability at di- and tetranucleotide repeat microsatellite loci

DEFF Research Database (Denmark)

Hansen, Michael Møller; Taggart, J.B.; Meldrup, Dorte

1999-01-01

Levels of variation at six VNTR (variable number of tandem repeats) loci, one minisatellite and five microsatellite loci, isolated from tri- and tetranucleotide enriched DNA libraries for northern pike were generally low in two Danish populations (1-4 alleles; expected heterozygosity 0-0.57), tho......Levels of variation at six VNTR (variable number of tandem repeats) loci, one minisatellite and five microsatellite loci, isolated from tri- and tetranucleotide enriched DNA libraries for northern pike were generally low in two Danish populations (1-4 alleles; expected heterozygosity 0...

Autoionic microscopy of damage regions of single atom displacement cascades in metals

International Nuclear Information System (INIS)

Suvorov, A.L.

1981-01-01

The defect region formation characterized by zones of depletion with atoms and interstitial halos arizing during displacement cascade development in an irradiated metal is considered. in experimental autoionmicroscopic analysis technique is used. The analysis procedure is briefly discussed: the experiment, the defect identification on autoionic image microphotos, computer data processing. The technique was applied for pure tungsten irradiated with 12 and 5.8 MeV deuterons and fission neutrons, and for tungsten-1.5% ThO 2 alloy irradiated with fast neutrons from fission fragments

Development of a demonstration reactor using thoria as a Fischer-Tropsch catalyst

International Nuclear Information System (INIS)

Colmenares, C.A.; McLean, W.

1981-12-01

We have demonstrated experimentally that thorium oxide may be used as a catalyst with CO + H 2 mixtures to produce either methanol or a mixture of hydrocarbons from C 1 to C 5 (saturated and unsaturated). The immunity of ThO 2 to poisoning by sulfur compounds makes its use very attractive for industrial applications. We are proposing to optimize the experimental conditions of the catalytic process using a one-inch reactor and to scope and define the experimental conditions for a pilot plant demonstration

Instrumentation for thermal diffusivity determination of sintered materials

International Nuclear Information System (INIS)

Turquetti Filho, R.

1990-01-01

A new procedure to measure the sinterized materials thermal diffusivity, using the heat pulse method was developed in this work. The experimental data were performed at room temperature with UO sub(2), ThO sub(2), and Al sub(2)O sub(3) samples with 94%, 95%, and 96% of theoretical densities, respectively. Nondimensional root mean square deviation for theoretical function fitting was found to be on the order, of 10 sup(-3). The total error associated with the measurements for thermal diffusivity was ± 5%. (author)

Proceedings of the 1976 Army Numerical and Computer Analysis Conference Held at US Army Research Office, Research Triangle Park, North Carolina, 11-12 February 1976

Science.gov (United States)

1976-09-01

3 PI TERMS LTV * FlrRCF,**f 1 + R)*LENfiTH**f2*A l TIrlF**17*i? - C) s smn flF EXPH~QSInN soL ~lT!nN FOR Pf TFRn FORCFn l * . innnnnanL 01 AREA... Sol vc tho governing equations implicitly, the same sp:tcr:-staggcrcd schcmc is used. The implicit code employs an alternating-direction tcchniquc...Hansen, W. "Hydrodynamical Methods Applied to Oceano - graphic Problems", Proceedings of the Symposium on Mathematical-Hydrodynamical Methods of

Observation of heavy cluster emission from radioactive 230U nuclei

International Nuclear Information System (INIS)

Pan Qiangyan; Yuan Shuanggui; Yang Weifan; Li Zongwei; Ma Taotao; Guo Junsheng; Liu Mingyi; Liu Hongye; Xu Shuwei; Gan Zaiguo; Kong Dengming; Qiao Jimin; Luo Zihua; Zhang Mutian; Wang Shuhong

1999-01-01

230 Pa was produced with the reaction 232 Th (p, 3n) 230 Pa in the irradiation powder targets of ThO 2 with 35 MeV proton beam. Sources of 230 Pa→ 230 U + β - were prepared by radiochemical method. Using solid-state track registration detectors, two events of 230 U decay with heavy cluster emission have been observed. The preliminary branching ratio to α-decay comes out to be B = λ Ne /λ α = (1.3 ± 0.8) x 10 -14

Colorectal cancer screening

OpenAIRE

McLoughlin, Monica Ramona

2008-01-01

Colorectal cancer is a major public health burden and is the most common cause of mortality from cancer in Europe. Over the last two decades robust evidence from randomised clinical trials and case-control series have confirmed that the mortality from colorectal cancer can be reduced by screening. The challenge over the next decade is how to implement this in clinical practice. This is what we set out to answer with this thesis. Not all individuals are equal when it comes to screening and tho...

Reference: 663 [Arabidopsis Phenome Database[Archive

Lifescience Database Archive (English)

Full Text Available opsis thaliana) is dominated by alkanes, secondary alcohols, and ketones, all tho...nt alleles was found to be devoid of secondary alcohols and ketones (mah1-1) or to contain much lower levels...topic accumulation of secondary alcohols and ketones in Arabidopsis leaf wax, where only traces of these com...pounds are found in the wild type. The newly formed leaf alcohols and ketones had midchain functional groups... catalyze the hydroxylation reaction leading from alkanes to secondary alcohols and possibly also a second h

Antibody-Mediated Targeting of Alpha PDGF Receptor to Inhibit the Progression of Skeletal Micro-Metastases

Science.gov (United States)

2012-10-01

determinants of metastasis. Semin Cancer Biol 2002; 12:89–96. 4. Fidler I. The pathogenesis of cancer metastasis: the “seed and soil ” hypothesis...degrad enviro on os shown shortl either teracti lesion pound as tho in can The (PDG related associ us (17 cer ce cell su used (ImC the tr curren IMC-3...specific soil . In support of this idea we have to  date considerable evidence indicating that migration of  cancer cells into a foreign tissue needs

Depth-Resolved Cathodoluminescence of Thorium Dioxide

Science.gov (United States)

2013-03-01

plutonium-239 (239Pu)-based nuclear weapons. Thorium also results in less highly radioactive waste in comparison to the uranium fuels. Thorium is four...diameters (1/4 – 3/8”) (Mann & Thompson, 2010). The 99.99% ThO2 powder was placed into the ampoule with a basic mineralizer such as cesium fluoride...conversion ranging from 1 pA/V to 1 mA/V. The electrical noise is further reduced by cooling the PMT housing unit with liquid nitrogen as seen in

Monte Carlo analyses of simple U233 O2-ThO2 and U235 O2-ThO2 lattices with ENDF/B-IV data (AWBA development program)

International Nuclear Information System (INIS)

Hardy, J. Jr.; Ullo, J.J.

1980-09-01

A number of water-moderated Th-U235 and Th-U233 lattice integral experiments were analyzed in a consistent manner, with ENDF/B-IV data and detailed Monte Carlo methods. These experiments provide a consistent test of the nuclear data. The ENDF/B-IV data are found to perform reasonably well. Adequate agreement is found with integral measurements of thorium capture. Calculated K/sub eff/ values show a generally coherent pattern which is consistent with K/sub eff/ results obtained for homogeneous aqueous critical assemblies. Harder prompt fission spectra for U233 and U235 can correct the principal discrepancy observed with ENDF/B-IV, a bias trend in K/sub eff/ attributed to an underprediction of leakage

Study of the sintering process and the formation of a (Th, U) O2 solid solution

International Nuclear Information System (INIS)

Tomasi, Roberto

1979-01-01

The effect of some variables in the (Th, U) O 2 sintering process and solid solution formation was studied. ThO 2 , U 3 O 8 and UO 2 powder were prepared. The ThO 2 powders were obtained by calcination of thorium at 500 and 750 deg C; the U 3 O 8 powders were derived from the calcination of ADU at 660 and 750 deg C; the UO 2 powder were prepared from ADU and from ATCU. The different characteristics of these materials were determined by measurements of surface area, by scanning electron microscopy, tap density tests, X-ray diffractometry and by measurements of the O/U ratios. The oxide mixtures were chosen in order to produce a final composition with 10 w/o of UO 2 . A mixture of thorium oxalate and ADU was also prepared by calcining these salts in air at 700 deg C, in order to obtain certain amount of solid solution prior to sintering. The sintering operations were developed in an argon atmosphere at temperatures between 1400 and 1700 deg C, during interval varying from 1 to 4 hours. The effect of the mixture characteristics on the sintering process and solid solution formation were studied considering the results of densification, microstructure development and X-ray diffractometry. The ThO 2 powder characteristics have a main effect on the mixtures compactability and sinterability, the higher calcining temperatures increasing the green density, but decreasing the final density of the sintered pellets. In the sintering of mixtures containing U 3 O 3 , this oxide is reduced to UO 2 and it is possible to obtain pellets with density and microstructures similar to those produced from mixtures containing UO 2 . But if oxygen in excess is present during sintering, the process is affected, occurring exaggerated grain growth. The densification results were related to the Coble's kinetics equation for second stage of sintering, valid for bulk diffusion, grain boundary acting as vacancy sinks. The sintering activation energy is independent from the powder starting

Some new and rare diatoms from South Africa 2. Diatoms from lake Sibayi and lake Nhlange in Tongaland (Natal)

CSIR Research Space (South Africa)

Archibald, REM

1966-01-01

Full Text Available 40.? (510.?) Heft 7: 3. W. THoMsoN, The Lichen Genus Physcia in North America. 1963. VIII. 212 pages, 1 figure, 25 plates, 36 maps. DM 60.? (:15.?) Heft 8: R. HAVES, A Taxonomic Monograph of the Genus Equisetum Subgenus Hippoehaete. 1963. IV, 124....?) Heft 12: C. W. DODGE, Some Lichens of Tropical Africa IV: Dermatocarpaceae to Pertusariacese. 1964. IV, 282 pages. 1DM 80.? (S 20.?) VERLAG VON J. CRAMER- 3301 LEHRE Heft 13: B. Y. DAwsoN, C. ACLETO and N. FOLDVIK, The Seaweed; of Peru. 1964. ?Rn...

Resilience and reworking practices

DEFF Research Database (Denmark)

Hauge, Mads Martinus; Fold, Niels

2016-01-01

of this article is to shed light on the agency of individual workers involved in rapid industrialization processes. In this endeavor we draw inspiration from recent contributions that have integrated Cindi Katz's threefold categorization of agency as reworking, resilience and resistance. In combination...... the labor market. The empirical part of the article draws on interviews with local and migrant first-generation workers in two settlements located next to an industrial zone in Can Tho Province in the Mekong River Delta Region of Vietnam. It is suggested that the alternating practices of reworking...

Marxist-Leninist Doctrine and Humanitarianism - Communist China

Science.gov (United States)

1960-11-20

wrote in his " Diary " - III56, f!convyciot.Iraesc iz tho"ý grc.-. ten’t ev’l, a.:’ it ca)n be mAid to be theý gRe-test evil a&ttainOaý’lc; by man." Latl...34dialecticralliy enters each, othezr." I n a word, acc,,ordin--g toPa Jen., on’ly by revealina’ the so-c.al’led "comrn-on basýý-Ic nn~tnre of mankind" aya

Compositional characterization of sintered (U,Th)O2 pellets by EDXRF using fused bead specimens

International Nuclear Information System (INIS)

Sanjay Kumar, S.; Dhara, Sangita; Misra, N.L.; Aggarwal, S.K.

2015-01-01

Fused bead specimens were used for analyzing sintered (U,Th)O 2 pellets by Energy Dispersive X-Ray Fluorescence (EDXRF) spectrometry. The bead specimens of calibration mixtures U 3 O 8 and ThO 2 were made by fusing them in Lithium Tetraborate/Metaborate fusion mixtures using a fusion bead machine. The EDXRF spectra of these beads were used for making calibration plot for U% determination in (U+Th) amounts. Using these calibration plots and EDXRF spectra of bead of sintered (U,Th)O 2 pellets, U% in these pellets was successfully determined. (author)

Importance of the single-particle continuum in BCS pairing with a pseudostate basis

Directory of Open Access Journals (Sweden)

Lay J. A.

2016-01-01

Full Text Available In a recent work [arXiv:1510.03185] the use of the Transformed Harmonic Oscillator (THO basis for the discretization of the singleparticle continuum into a Generalized Bardeen-Cooper-Schrieffer (BCS formalism was proposed for the description of weakly bound nuclei. We make use of the flexibility of this formalism to study the evolution of the pairing when the nucleus becomes more and more weakly bound. Specifically we focus on the evolution of the occupation of the different partial waves in 22O when the Fermi level approaches zero.

Tank Tests on Water Rudders for Float Seaplanes

Science.gov (United States)

1939-11-01

a Jr.l;.’ to inveeti -atj the technique of the method . Cone luol one At a speod oi 10 knots In the flrat set o. tout a the yawing moments...required for maintaining a atrni ht aourse in a slduulnd. The whirling arm method can lvo iwauuremunta ol tho turning sireles obtainable with dl.ferent...ore« aa« paala« aaaaata.1,1’ It »aa aaaiawd that taa air an« « atar roadero aora« thron-h -h» aaao angle. .1« balance of too lorceo aa

Solar air-conditioning in buildings of houses; Climatizacion solar en edificios de viviendas

Energy Technology Data Exchange (ETDEWEB)

Rey, F. J.; Velasco, E.; Flores, F.; Gonzalez, A. B.

2008-07-01

In this work we analyze the behavior of the components of a thermal solar energy captation system that provides support to a climatization system with low energy consumption composed by radiating-refreshing ground in a single family dwelling. The combination of both system allows to increase the efficiency of the climatization and to reduce the energy domestic consumption. These aspects are included in regional an national strategies of saving and efficiency energy. tho this end, we shall use the software TRNSYS 16 for the energy systems simulation. (Author)

Molecular cluster theory of chemical bonding in actinide oxide

International Nuclear Information System (INIS)

Ellis, D.E.; Gubanov, V.A.; Rosen, A.

1978-01-01

The electronic structure of actinide monoxides AcO and dioxides AcO 2 , where Ac = Th, U, Np, Pu, Am, Cm and Bk has been studied by molecular cluster methods based on the first-principles one-electron local density theory. Molecular orbitals for nearest neighbor clusters AcO 10- 6 and AcO 12- 8 representative of monoxide and dioxide lattices were obtained using non-relativistic spin-restricted and spin-polarized Hartree-Fock-Slater models for the entire series. Fully relativistic Dirac-Slater calculations were performed for ThO, UO and NpO in order to explore magnitude of spin-orbit splittings and level shifts in valence structure. Self-consistent iterations were carried out for NpO, in which the NpO 6 cluster was embedded in the molecular field of the solid. Finally, a ''moment polarized'' model which combines both spin-polarization and relativistic effects in a consistent fashion was applied to the NpO system. Covalent mixing of oxygen 2p and Ac 5f orbitals was found to increase rapidly across the actinide series; metal s,p,d covalency was found to be nearly constant. Mulliken atomic population analysis of cluster eigenvectors shows that free-ion crystal field models are unreliable, except for the light actinides. X-ray photoelectron line shapes have been calculated and are found to compare rather well with experimental data on the dioxides

Evolution of actinides in ThO2 blanket of prototype fast breeder reactor

International Nuclear Information System (INIS)

Bachchan, Abhitab; Riyas, A.; Devan, K.; Puthiyavinayagam, P.

2015-01-01

The third stage of India's nuclear program focuses on fissile fuel production through Th- 233 U cycle in view of the better abundance and relative merits of thorium. For early introduction of Thorium into the nuclear energy system, several R and D program has started to find the best possible route of thorium utilization. Towards this, efforts were made to assess the feasibility of Th-U cycle in a fast spectrum reactor like Prototype Fast Breeder Reactor (PFBR). The effect on core neutronic parameters and actinide evolution with the replacement of depleted UO 2 in the PFBR blanket SA with thorium oxide has been studied using 3-D diffusion code FARCOB. Study shows that by the introduction of thorium blanket, core excess reactivity is coming down by ∼ 535 pcm and core breeding ratio is slightly lower than conventional oxide blanket. The distribution of region wise power production is slightly changed. Power from radial blanket is reduced from 3% to 2% while the core-1 power is increased from 49 % to 50 %. The estimated 233 U production is 7.6, 11.5 and 14.1 kg/t with 180, 360 and 540 days of irradiation respectively. (author)

Dissecting mechanisms of nuclear mRNA surveillance in THO/sub2 complex mutants

DEFF Research Database (Denmark)

Rougemaille, Mathieu; Gudipati, Rajani K; Olesen, Jens Raabjerg

2007-01-01

The nuclear exosome is involved in numerous RNA metabolic processes. Exosome degradation of rRNA, snoRNA, snRNA and tRNA in Saccharomyces cerevisiae is activated by TRAMP complexes, containing either the Trf4p or Trf5p poly(A) polymerase. These enzymes are presumed to facilitate exosome access...... is required for both retention and degradation of nuclear restricted mRNAs. We show here that Trf4p, in the context of TRAMP, is an mRNA surveillance factor. However, unlike Rrp6p, Trf4p only partakes in RNA degradation and not in transcript retention. Surprisingly, a polyadenylation-defective Trf4p protein...

Service life prediction. Development of models for predicting the service life of power plant components subject to thermomechanical creep fatigue; Lebensdauervorhersage. Entwicklung von Modellen zur Lebensdauervorhersage von Kraftwerksbauteilen unter thermisch-mechanischer Kriechermuedungsbeanspruchung. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Cui, L.; Scholz, A. [Technische Univ. Darmstadt (Germany). Institut fuer Werkstoffkunde; Hartrott, P. von; Schlesinger, M. [Fraunhofer-Institut fuer Werkstoffmechanik (IWM), Freiburg im Breisgau (Germany)

2009-07-01

Extensive use is made of massive components of heat resistant and highly heat resistant materials in installations of the power and heating industry. These components are exposed to varying thermomechanical stress as a result of ramping-up and down processes. In this research project two computer-assisted methods of predicting service life until crack initiation were extended to include cases of thermomechanical multi-axis stress conducive to creep fatigue and of superposition of high-cycle stress on power plant components. Investigations were limited to rotor steel of type X12CrMoWVNbN10-1-1. Complex thermomechanical multi-axis experiments were performed on round, notched and cruciform test specimens of close-to-life dimensions in order to demonstrate by experiment the validity of these models. The results of these calculations showed an acceptable degree of agreement between experiment and simulation for both models. Calculations on earlier TMF experiments performed at IfW on hollow specimens of 1%CrMoNiV showed good predictability for both the SARA and the ThoMat programme. Calculations on experiments performed at MPA Stuttgart on model bodies consisting of the same 1%CrMoNiV showed a predictability of acceptable variability considering the complexity of the stresses involved. A further outcome of this project is that the use of SARA appears universally suitable for the construction of new plants and in the service area, while the use of ThoMat appears suited for detail optimisation in the development process.

The metabolism of tritium and water in the lactating dairy cow

Energy Technology Data Exchange (ETDEWEB)

van den Hoek, J; ten Have, M H.J.

1983-02-01

Two lactating Friesian cows received tritiated water (19 nCi of tritium per ml) to drink for 25 days. Urine and milk samples were collected and analyzed for tritium content. Plateau levels in milk water, and in milk fat, lactose and casein were reached in about 18 days. Tritium concentration in milk water and urine water was about 82% that in drinking water, indicating dilution with water from food and metabolic processes, and as a result of exchange through lungs and skin. At steady state, tritium activity in milk fat, lactose and casein was about 30, 28 and 15% of that in drinking water on a weight basis; at this time, about 1.5% of the daily ingested tritium appeared in one litre of milk in both animals. Comparison of the specific activity of the various milk constituents with the specific activity of the body water showed that the highest tritium incorporation occurred in lactose (0.58), followed by milk fat (0.36) and casein (0.27). Tritium incorporation in milk dry matter (0.45) is considerably higher than in most tissue components of several mammalian species after continuous ingestion of THO as reported in the literature. Tritium levels fell rapidly in milk and urine after the administration of THO was stopped, with half-times of around 4 days for the rapid components in all milk constituents. A slow component of 44 days, 225 days and 24 days half-time was found in milk water, milk fat and casein respectively.

Perception of Climate Risk among Rural Farmers in Vietnam: Consistency within Households and with the Empirical Record.

Science.gov (United States)

Cullen, Alison C; Anderson, C Leigh

2017-03-01

Rural farmers in Vietnamese communes perceive climate risk and potential impacts on livelihood within a complex context that may influence individual and household decisions. In a primary survey of 1,145 residents of the Thach Ha district of Ha Tinh province, we gathered data regarding perception about stability in climate, potential risks to livelihood, demographic characteristics, orientation toward risk, and interest in expanding economic activity. Temporal analysis of meteorological and economic indicator data forms an empirical basis for comparison with human perception. We ask the basic question: Are rural farmers' perceptions of climate consistent with the historical record and reproducible within households? We find that respondents do perceive climate anomalies, with some anchoring on recent extreme events as revealed by climate observational data, and further that spouses disproportionately share perceptions relative to randomly simulated pairings. To put climate-related risk perception in a larger context, we examine patterns across a range of risks to livelihood faced by farmers (livestock disease, pests, markets, health), using dimension reduction techniques. We find that our respondents distinguish among potential causes of low economic productivity, with substantial emphasis on climate-related impacts. They do not express uniform concern across risks, but rather average patterns reveal common modes and distinguish climate concern. Still, among those expressing concern about climate-related risks to livelihood we do not find an association with expressed intention to pursue changes in economic activity as a risk management response. © 2016 Society for Risk Analysis.

Elaboration and characterization of solid electrolytes for electrochemical oxygen sensors in liquid sodium

International Nuclear Information System (INIS)

Gabard, M.

2013-01-01

This PhD thesis was prepared within the framework of the research program on 'Generation IV' nuclear reactors with sodium as coolant. One of the main technological problem concerns the control of the corrosion processes of the materials (structural materials, fuel claddings, etc.) by liquid sodium. A key parameter is the dissolved oxygen content in the coolant. This thesis focuses on the development and characterization of ceramic materials based on ThO 2 doped with Y 2 O 3 for making potentiometric oxygen sensor used in liquid sodium. Work has been carried out and probes were tested in the past, however, the probes had at the time, a lack of reliability. The objective of this thesis is to develop and characterize electrolytes based on thorium oxide doped with yttrium oxide using specific synthesis techniques to control purity, grain size, compactness, etc. To develop experimental protocols a ceramic model has been chosen, i.e., yttria-doped ceria. Transport processes were studied using the impedance spectroscopy technique. An interpretation of the blocking phenomena of the ionic conduction in both ceramics as a function of the oxygen partial pressure has been given. (author) [fr

Potential of duplex fuel in prebreeder, breeder, and power reactor designs: tests and analyses (AWBA Development Program)

International Nuclear Information System (INIS)

Chao, T.L.; Brennan, J.J.; Duncombe, E.; Schneider, M.J.; Johnson, R.G.R.

1982-09-01

Dual region fuel pellets, called duplex pellets, are comprised of an outer annular region of relatively high uranium fuel enrichment and a center pellet of fertile material with no enrichment. UO 2 and ThO 2 are the fissile and fertile materials of interest. Both prebreeders and breeders are discussed as are the performance advantages of duplex pellets over solid pellets in these two pressurized water reactor types. Advantages of duplex pellets for commercial reactor fuel rods are also discussed. Both irradiation test data and analytical results are used in comparisons. Manufacturing of duplex fuel is discussed

A Conceptual and Analytical Study of the Utility of Speed in Naval Operations. Volume 2. Appendix

Science.gov (United States)

1976-07-01

thcocsiatii The portion of thon tot~al t~rii-nnnncr ~t~atioi cotnt wh 1.c~h irn afi:3iqcdf~c to thto carga i tself is the cargo value times the...the propulsion syn- tom and the mode of transport . The transportation cost im given by tho expronsiont Transportat~ion Cost CQI’T’ 4 C QT -i kVc’DQ...to the convoy speed of advance. Then, since S C we get P~ o or, D- de VvV V V V19 where TD if wo incrca;n the numbur of (,ijuortii to n, thon th. iprilt

China Macroeconomic: Documentation Data Banks. Volume 3. Foreign Trade.

Science.gov (United States)

1984-11-15

1983 data from Chlnese "Cmtan, Statistics," Econmic Infomation and Agency, THoE ong Pr ious years from CIA "International Trade Statistics" Load fram...204,097 145,564 515,062 1984 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 6 Sources, see below 19F, 1983 data from Chinese "Customs Statistics," Econmic ...Statistics," EconmIc Information and Agency, F org Previous years fran CIA "Internationl Trade Statistics" Load from rw 12 to row 54 -.96 - A B C D E F G H

Evidence for heavy ion emission of 230U

International Nuclear Information System (INIS)

Pan Qiangyan; Yang Weifan; Yuan Shuanggui; Li Zongwei; Ma Taotao; Guo Junsheng; Liu Mingyi; Liu Hongye; Xu Shuwei; Gan Zaiguo; Kong Dengming; Qiao Jimin; Luo Zihua; Zhang Mutian; Wang Shuhong

1999-01-01

Radioisotope of 230 Pa was synthesized by proton irradiation of ThO 2 powder targets with thickness of about 2g/cm 2 . Pure 230 Pa was extracted and deep purified from thorium and fission products by the radiochemical method. Thin 230 Pa→ 230 U sources were prepared for measuring the cluster decay of 230 U. Two cases of decay via heavy ion emission, which were most probably for the neon decays of 230 U, were detected by using solid-state track registration detectors. The preliminary branching ratio relative to α-decay comes out to be (1.3 +- 0.8) x 10 -14

Radiation damage of uranium-thorium oxide, irradiated in water

International Nuclear Information System (INIS)

Bloem, P.J.C.; Nagel, W.; Plas, T. van der; Kema, N.V.

1977-01-01

A suspension in water of spherical particles of UO 2 -ThO 2 with diameter 5μm has been considered as the working fluid in an aqueous, homogeneous, thermal nuclear reactor. Irradiation experiments have shown that these particles suffer a gradual breakdown when irradiated in water. This behaviour is markedly different from that shown on irradiation in absence of water. As damage was defined the amount of solid dissolved by an etching liquid. Electron microscopic pictures showed that at higher irradiation temperatures in water the actual damage was larger than the etching values indicated. (orig.) [de

Selection of LEU/Th reference fuel for the HTGR-SC/C lead plant

International Nuclear Information System (INIS)

Turner, R.F.; Neylan, A.J.; Baxter, A.M.; McEachern, D.W.; Stansfield, O.M.

1983-05-01

This paper describes the reference fuel materials for the high-temperature gas-cooled reactor (HTGR) plant for steam cycle/cogeneration (SC/C). A development and testing program carried out in 1978 through 1982 led to the selection of coated fuel particles of uranium-oxycarbide (UCO) for fissile materials and thorium oxide (ThO 2 ) for fertiel materials. Low-enriched uranium (LEU) is the enrichment basis for the HTGR-SC/C application. While UC 2 and UO 2 would also meet the essential criteria for fissile fuel, the UCO, alternative was selected on the basis of improved performance, economics, and process conditions

The use of thermally stimulated depolarization currents to study grain growth in ceramic thorium dioxide

International Nuclear Information System (INIS)

Muccillo, R.; Campos, L.L.

1979-01-01

Depolarization Current Spectra resulting from the destruction of the thermoelectret state in polycrystalline ThO 2 samples have been detected in the temperature range 100K-350K. The induced polarization is found to be due to migration of charge carriers over microscopic distances in the bulk of the specimens with trapping at grain boundaries. Moreover the density of charge carriers released from trapping sites, upon heating the cooled previously dc biased specimen decreases for increasing sintering temperature, suggesting the use of the technique to the study of grain growth in the bulk of ceramic oxides. (Author) [pt

A Study of Strategic Lessons Learned in Vietnam. Volume 5. Planning the War

Science.gov (United States)

1980-04-04

VLCCL 9I) 1 0. 0 Iii N 2 -- 3 !Q MR’ THE BDM CORPORATION cni -J u uw wi LU w.. 4 p𔃼 CL 0.C WV U. 4-) ww jW U lm. C-.) 𔃾- ZEC 00 - L ccn U) 0zz up...78. 61, Duncanson, p. 321 and Lewy, p. 25. 62. Tran Dinh Tho, p. 15. 63. William Colby and Peter Forbath, Honourable Men: My Life in the CIA (London...American peace advocate Peter Weiss, Harvard professor Henry Kissinger; and several pacifist clerics 7-25 THE BDM CORPORATION * elicit the assistance of

The Early Operations of the Eighth Air Force and the Origins of the Combined Bomber Offensive, 17 August 1942 to 10 June 1943

Science.gov (United States)

1946-10-01

CBO Plant , approved late in Hay 1943, outlined four phases for , the combined operation, the first beginning with April of that year. 3oao reports...traitsportatioa nystew, oil aad potroloua plants , sdroraft faotorios, alvaaiaua aad sMkgaoslitti plants , submarine installation*, and naval basoo...fr?>» tli« cww*.1 lalti»Hy It a*d b*«i reported thai tho bo«b«m tm thli alMlon had d*»tray«<i 94. probably d**troy«d 2S, and dat»a£«4 20. J.« cordia

Water Supply or ‘Beautiful Latrines’? Microcredit for Rural Water Supply and Sanitation in the Mekong Delta, Vietnam

Directory of Open Access Journals (Sweden)

Nadine Reis

2012-01-01

Full Text Available Around half of the Mekong Delta’s rural population lacks year-round access to clean water. In combination with inadequate hygiene and poor sanitation this creates a high risk of diseases. Microcredit schemes are a popular element in addressing such problems on the global policy level. The present paper analyses the contradictory results of such a microcredit programme for rural water supply and sanitation in the context of the Mekong Delta, Vietnam, through a qualitative study primarily based on semi-structured interviews in rural communes of Can Tho City. We come to the conclusion that the programme has a positive effect regarding the safer disposal of human excreta as well as surface water quality, but a marginal impact on poverty reduction as it only reaches better-off households already having access to clean water. The paper shows how the outcome of rural water supply and sanitation policies are strongly influenced by the local ecological, technological, and social settings, in particular by stakeholders’ interests. The authors challenge the assumption that water supply and sanitation should be integrated into the same policy in all circumstances. ----- Etwa die Hälfte der ländlichen Bevölkerung des Mekong-Deltas hat nicht das ganze Jahr über Zugang zu sauberem Wasser. Zusammen mit unzureichender Hygiene und mangelnder sanitärer Grundversorgung erhöht diese Situation das Krankheitsrisiko. Auf globaler Ebene sind Mikrokreditprogramme eine gefragte Strategie, um diese Probleme zu behandeln. Der vorliegende Artikel analysiert die widersprüchlichen Ergebnisse eines solchen Mikrokreditprogramms für ländliche Wasser- und sanitäre Grundversorgung im Mekong-Delta in Vietnam im Rahmen einer qualitativen Studie, die auf halbstrukturierten Interviews im Raum Can Tho City basiert. Die Studie kommt zu dem Schluss, dass das Programm eine positive Wirkung in Bezug auf die sichere Entsorgung von Fäkalien und die Qualität des Regenwassers

Structure-soil-structure interaction of nuclear structures

International Nuclear Information System (INIS)

Snyder, M.D.; Shaw, D.E.; Hall, J.R. Jr.

1975-01-01

Structure-to-structure interaction resulting from coupling of the foundations through the soil has traditionally been neglected in the seismic analysis of nuclear power plants. This paper examines the phenomenon and available methods of analytical treatment, including finite element and lumped parameter methods. Finite element techniques have lead to the treatment of through soil coupling of structural foundations using two dimensional plane strain models owing to the difficulty of considering three dimensional finite element models. The coupling problem is treated by means of a lumped parameter model derived from elastic half-space considerations. Consequently, the method is applicable to the interaction of any number of foundations and allows the simultaneous application of tri-directional excitation. The method entails the idealization of interacting structures as lumped mass/shear beams with lumped soil springs and dampers beneath each foundation plus a coupling matrix between the interacting foundations. Utilizing classical elastic half-space methods, the individual foundation soil springs and dampers may be derived, accounting for the effects of embedment and soil layering, analogous to the methods used for single soil-structure, interaction problems. The coupling matrix is derived by generating influence coefficients based on the geometric relationship of the structures using classical half-space solutions. The influence coefficients form the coupling flexibility matrix which is inverted to yield the coupling matrix for the lumped parameter model

Fluid-structure interaction of submerged structures

International Nuclear Information System (INIS)

Tang, H.T.; Becker, E.B.; Taylor, L.M.

1979-01-01

The purpose of the paper is to investigate fluid-structure interaction (FSI) of submerged structures in a confined fluid-structure system. Our particular interest is the load experienced by a rigid submerged structure subject to a pressure excitation in a fluid domain bounded by a structure which is either flexible or rigid. The objective is to see whether the load experienced by the submerged structure will be influenced by its confinement conditions. This investigation is intended to provide insight into the characteristics of FSI and answer the question as to whether one can obtain FSI independent data by constructing a small scale rigid submerged structure inside a flexible fluid-structure system. (orig.)

Contribution to characteristics of uranium oxides

International Nuclear Information System (INIS)

Fritsche, R.; Dahlkamp, F.J.

2001-01-01

Uranium oxides from pegmatitic, metamorphic and metasomatic uranium occurrences were investigated with the objective to check for differences in their physico-chemical properties and, whether such properties are sufficiently distinct to be applied as an exploration tool. Research methods included microscopy, electron microprobe and X-ray diffractometry amended by determinations of reflectance, Vickers hardness, unit-cell dimension and oxidation grade. Tentative research results are as follows: (a) U-oxides (uraninites) of pegmatites always contain significant amounts of Th (1,5-10 wt.% ThO2). (b) U-oxides from metasomatic environments have high, but variable contents of Fe, Ca, Ti, Si and Th (around 10 wt.%), Th being low. (c) U-oxides crystallised during metamorphism contain minor impurities of the above listed elements (total of oxides < 2 wt.%). (d) Redistributed U-oxides have elevated amounts of these elements. (e) Unit-cell dimensions of U-oxides tend to reflect a complex function of formation temperature, oxidation grade and the influence of incorporated elements caused by their radius and electro-negativity. (f) A global negative correlation of unit-cell dimension and oxidation grade of uranium oxides is indicated but based on widely varying ratios of the two parameters. (g) Colloform U-oxide (pitchblende) is characterised by elevated Ca-contents (1-5 wt.% CaO) and an almost complete lack of Th (< 1 wt.% ThO2). (h) Idiomorphic U-oxide (uraninite) is commonly low in Ca (< 1.5 wt.% CaO) but contains relatively high Th values. (i) The reflectance of U-oxides generally correlates positively with Vickers hardness and unit-cell dimension, but the incorporation of other elements in the lattice of U-oxides may cause strong interference. (author)

Computational structural mechanics for engine structures

Science.gov (United States)

Chamis, C. C.

1989-01-01

The computational structural mechanics (CSM) program at Lewis encompasses: (1) fundamental aspects for formulating and solving structural mechanics problems, and (2) development of integrated software systems to computationally simulate the performance/durability/life of engine structures. It is structured to mainly supplement, complement, and whenever possible replace, costly experimental efforts which are unavoidable during engineering research and development programs. Specific objectives include: investigate unique advantages of parallel and multiprocesses for: reformulating/solving structural mechanics and formulating/solving multidisciplinary mechanics and develop integrated structural system computational simulators for: predicting structural performances, evaluating newly developed methods, and for identifying and prioritizing improved/missing methods needed. Herein the CSM program is summarized with emphasis on the Engine Structures Computational Simulator (ESCS). Typical results obtained using ESCS are described to illustrate its versatility.

Enhancing proliferation resistance in advanced light water reactor fuel cycles

International Nuclear Information System (INIS)

Kazimi, M.S.; Pilat, E.E.; Driscoll, M.J.; Xu, Z.; Wang, D.; Zhao, X.

2001-01-01

Alternative once-through, light water reactor fuel designs are evaluated for capability to reduce the amount and quality of plutonium produced. Doubling the discharge burnup is quite effective, producing modest reductions in total plutonium and significant increases in 238 Pu whose heat generation and spontaneous neutrons complicate weapon usability. Reductions in the hydrogen to heavy metal ratio are counterproductive. Increases are helpful, but only small changes can be accommodated. Use of ThO 2 in a homogeneous mixture with UO 2 can reduce plutonium production to about 50% of that in a typical present day PWR, and in heterogeneous seed-blanket designs can reduce it to 30 to 45%. (author)

Health effects following long-term exposure to Thorium dusts. A fourteen-year follow-up study in China

International Nuclear Information System (INIS)

Chen Xingan; Cheng Yonge; Zhen Rong

2002-01-01

The long-term monitoring of thorium inhaled by workers and assessment of their thorium lung burden has been carried out in China since 1960. Various monitoring methods have been adopted, such as chemical analysis of thorium concentration in urine samples: assessing thorium lung burden by measurement of 212 Pb etc. using a whole-body counter: measurement of exhaled thoron using a ZnS detector; or exhaled thoron decay products using an electrostatic collection system. Our experience over more than 20 years has shown that the last named measurement system is the best method for monitoring and assessing the lung burden of thorium (ThO 2 ) inhaled by miners and workers. (author)

Gibbs energies of formation of zircon (ZrSiO4), thorite (ThSiO4), and phenacite (Be2SiO4)

International Nuclear Information System (INIS)

Schuiling, R.D.; Vergouwen, L.; Rijst, H. van der

1976-01-01

Zircon, thorite, and phenacite are very refractory compounds which do not yield to solution calorimetry. In In order to obtain approximate Gibbs energies of formation for these minerals, their reactions with a number of silica-undersaturated compounds (silicates or oxides) were studied. Conversely baddeleyite (ZrO 2 ), thorianite (ThO 2 ), and bromellite (BeO) were reacted with the appropriate silicates. As the Gibbs energies of reaction of the undersaturated compounds with SiO 2 are known, the experiments yield the following data: Δ G 298 , 1 /sub bar/ 0 = -459.02 +- 1.04 kcal for zircon, -489.67 +- 1.04 for thorite, and -480.20 +- 1.01 for phenacite

In-pile intragranular densification of oxide fuels (AWBA Development Program)

International Nuclear Information System (INIS)

Dollins, C.C.; Nichols, F.A.

1977-10-01

This report proposes a model to describe in-pile densification of oxide fuels, by both vacancy boil-off due to thermal excitation and vacancy knockout by the passage of fission fragments through the pores. The model includes the migration rates of both vacancies and interstitials to pores and the production of vacancy-rich damage cascades by fission fragments. It has been coupled with a previously reported swelling and gas release model so that it can predict the total dimensional changes of the fuel as well as predicting intragranular densification for both ThO 2 and UO 2 fuels for advanced water breeder reactor applications development effort

Wave power potential along the Indian coasts

Digital Repository Service at National Institute of Oceanography (India)

Das, V.K.; Ramesh, B A.; Varkey, M.J.

monlh a. lhe v;Ruolly ob.ervell wnve heighl. have been con.idered at equivalent to llle RigniliclUlt wave heigh!. Average of .11 period. repolted in thai DJ'Ca ia laken IIR T. The tho e.!imale. have to be con.idellld with caution The environmental aSpe<:ta 10 be mainly...

Cobalt-Free Permanent Magnet Alloys.

Science.gov (United States)

1984-10-01

ThC Ferrites (Zn, Mn. Cu, Fe)O A12O. Al TiC Kaolin Al203.Si02-Fe2O3 Fe2O3 Li B4C Spodumene LiAI (SiOs) 2 ThO2 Ni UC Rhodonite NtnO. SiO2 MnOs Fe TaC...minutes. X-ray diffraction pattern indicated the presence of magnetic T phase. Hysteresis loop was measured on the heat treated powder dispersed in wax...fmgei * T phse Hysersi loo was mesue on the. heat - treated ,--". " powder dispersed in wax... The’ result wer as"- follows: • , " • "• . I TABLE 6

Analysis of uranium and thorium thin targets irradiated at the PSI accelerator

International Nuclear Information System (INIS)

Wenger, H.U.; Botta, F.; Chawla, R.; Daum, M.; Gavillet, D.; Hegedues, F.; Ingold, F.; Kopajtic, Z.; Ledergerber, G.; Linder, H.P.; Roellin, S.; Wichser, J.; Wyss, F.

1997-01-01

The aim of the ATHENA programme at PSI is to provide experimental data for the validation of theoretical models in nucleon-meson transport codes used for accelerator-based transmutation studies. Emphasis is placed on the mass yield distribution of spallation and fission products for irradiated thin actinide targets. This paper presents results of an irradiation experiment carried out with 238 UO 2 and 232 ThO 2 . Isobaric production cross-sections of fission and spallation products based on mass spectrometric measurements and γ-spectroscopy are compared with calculations carried out using the HETC code and the RAL high-energy fission model. (author) 6 figs., 8 refs

Effect of ThO2 concentration on thermo-physical properties of barium borosilicate glass

International Nuclear Information System (INIS)

Mishra, R.K.; Munshi, A.K.; Kaushik, C.P.; Raj, Kanwar; Shobha, M.; Srikhande, V.K.; Kothiyal, G.P.; Tyagi, A.K.

2006-01-01

An advanced heavy water reactor is being developed at Bhabha Atomic Research Centre (BARC) India with an aim of utilizing thorium for power generation. The high level radioactive liquid waste (HLW) generated from reprocessing of Th-based spent fuel is expected to contain Th as one of the main constituents other than fission products, corrosion products, actinides and added chemicals. Barium borosilicate (BBS) glass is being used for vitrification of the HLW generated at the reprocessing plant at BARC, Trombay, Mumbai

UV induced photoluminescence and thermally stimulated luminescence of ThO2:Tb3+ phosphor

International Nuclear Information System (INIS)

Godbole, S.V.; Nagpal, J.S.; Page, A.G.

2000-01-01

Thorium oxide doped with trivalent terbium ions offers itself as a novel phosphor with its photo- and thermally-stimulated luminescence (PL and TSL) characteristics showing a marked change on sustained exposure to 254 and 365 nm ultraviolet (UV) radiation. The reduction in luminescence intensity of Tb 3+ ions, on irradiation with 254 nm photons and subsequent restoration on exposure to 365 nm, has been correlated with the complimentary behaviour in UV-induced TSL. These changes are, in turn, ascribed to inter-configurational (f-d) transitions and e-h formation and recombination processes. UV radiation induced TSL output increases linearly with incident UV radiant energy at a constant radiation flux; however, for a fixed exposure, TSL output increases with increase in radiant flux

Crystal Growth and Characterization of THO2 and UxTh1-xO2

Science.gov (United States)

2013-03-01

the opaqueness is a result of crystalline defects or a result of the Beer -Lambert law is difficult to say, though both factors are likely...Alloys and Compounds, vol. 451, no. 1–2, pp. 248–250, Feb. 2008. [5] S. L. Chaplot, R. Mittal, and N. Choudhury, Eds., Thermodynamic Properties of...Defective UO 2 (100),” The Journal of Physical Chemistry B, vol. 108, no. 7, pp. 2362–2364, Feb. 2004. [9] J. M. Haschke, “ Thermodynamics of water

REDUPP. Second annual report

International Nuclear Information System (INIS)

Zetterstroem Evins, L.; Vaehaenen, M.

2013-05-01

Understanding the interactions between solid surface and fluid during the dissolution process is essential for developing a model for spent fuel dissolution. This project aims to enhance the understanding of the dissolution process of fluorite-type materials; these have the same crystal structure as nuclear fuel. CaF 2 , CeO 2 , ThO 2 and UO 2 are here used in dissolution studies during which the evolution of the solution and surface is monitored as the dissolution proceeds. For the UO 2 -experiments, the effect of natural groundwater on the dissolution of a surface emitting alpha radiation is investigated. The goal is to use the experimental results in combination with first-principles modelling to formulate a model describing the surfaces of dissolving fluorite-type materials. The project is on-going and this report presents the progress after two years. The experimental results reported here point towards effects of surface area and surface area to volume ratios, exposed grain boundaries, and bulk vs. 'local' solubility. The importance of well-controlled analytical conditions and high-resolution measurements are emphasized, in order to distinguish differences between effects of remnant fines, amorphous precipitates, grain boundaries, surface defects and crystallographic orientation of the exposed surfaces. The progress with regards to modelling shows that a surface model is formulated which can predict the surface formation energies of all crystal planes of the fluorite structure. It has been shown that this quantity can be related with the experimental surface stability during dissolution, and that for any material with the fluorite structure the same relation between computed surface stability and experimental stability (dissolution rate) will hold. The work on setting up a model of the dissolution process is ongoing; this kind of modelling is computationally very demanding as it requires a combination of molecular dynamics simulations and ab initio electronic

Na-metasomatism in the uranium fields of Singhbhum Shear zone, India

International Nuclear Information System (INIS)

Chaki, Anjan

2013-01-01

Singhbhum Shear Zone (SSZ) of eastern India hosts uranium, copper and apatite-magnetite mineralization, which occurs either independently or overlaps in space. SSZ is a nearly 200 km long, 1-5 km wide, intensely techtonized, northward-convex, arcuate mobile belt that separates the Archaean cratonic nucleus to its south from the Proterozoic North Singhbhum Fold Belt on the north. Except Bagjata mines in the eastern sector, majority of the known uranium deposits and mines (e.g. Jaduguda, Bhatin, Narwapahar, Banduhurang and Mohuldih) are situated in the central sector of the shear zone. All the deposits are of low grade (0.05% U 3 O 8 ) and low to medium tonnage. The common rock types of the SSZ are quartz-chlorite schists, quartzsericite schists, quartzite, metaconglomerate, soda granite, quartz-albite bearing schists/gneisses, granophyres and tourmalinite. The mineralization occur as lenticular to tabular bodies, which are (pene-) concordant with dominant planer structures, i.e. foliation parallel with the lithological layering (S 3 II S 0 ). Principal uranium mineral is uraninite with low thorium (UO 2 /ThO 2 =70-150), high lead (PbO =14-15%) and moderate REE contents with minor pitchblende and some secondary minerals near the surface. Many ore minerals, particularly the sulfide phases of Ni, Co, Mo, Cu and Fe are common

Retardation of uranium and thorium by a cementitious backfill developed for radioactive waste disposal.

Science.gov (United States)

Felipe-Sotelo, M; Hinchliff, J; Field, L P; Milodowski, A E; Preedy, O; Read, D

2017-07-01

The solubility of uranium and thorium has been measured under the conditions anticipated in a cementitious, geological disposal facility for low and intermediate level radioactive waste. Similar solubilities were obtained for thorium in all media, comprising NaOH, Ca(OH) 2 and water equilibrated with a cement designed as repository backfill (NRVB, Nirex Reference Vault Backfill). In contrast, the solubility of U(VI) was one order of magnitude higher in NaOH than in the remaining solutions. The presence of cellulose degradation products (CDP) results in a comparable solubility increase for both elements. Extended X-ray Absorption Fine Structure (EXAFS) data suggest that the solubility-limiting phase for uranium corresponds to a becquerelite-type solid whereas thermodynamic modelling predicts a poorly crystalline, hydrated calcium uranate phase. The solubility-limiting phase for thorium was ThO 2 of intermediate crystallinity. No breakthrough of either uranium or thorium was observed in diffusion experiments involving NRVB after three years. Nevertheless, backscattering electron microscopy and microfocus X-ray fluorescence confirmed that uranium had penetrated about 40 μm into the cement, implying active diffusion governed by slow dissolution-precipitation kinetics. Precise identification of the uranium solid proved difficult, displaying characteristics of both calcium uranate and becquerelite. Copyright © 2017 Elsevier Ltd. All rights reserved.

Organisational Structure – Structures for Growth

OpenAIRE

Ramskill, Jason

2011-01-01

Summary Rexam Plc has articulated that part of the company’s strategy is to make a carefully managed expansion into the emerging markets. In this report I suggest an alternative structure for Rexam to enable implementation of such a strategy and propose a business process for designing effective organisational structures. The work of Chandler (1962) charts the evolution of company organisational structures from the early centralised structures of the 1920s to the multidivisional str...

Structural optimization of free-form reciprocal structures

DEFF Research Database (Denmark)

Parigi, Dario

2014-01-01

This paper presents an optimization algorithm for the design of structurally efficient free-form reciprocal structures. Because of the geometric complexity of reciprocal structures, only a few structural studies have been carried out so far, and we have a limited knowledge of the relation between...

Structural cladding /clad structures

DEFF Research Database (Denmark)

Beim, Anne

2012-01-01

Structural Cladding /Clad Structures: Studies in Tectonic Building Practice A. Beim CINARK – Centre for Industrialized Architecture, Institute of Architectural Technology, The Royal Danish Academy of Fine Arts School of Architecture, Copenhagen, Denmark ABSTRACT: With point of departure in the pr......Structural Cladding /Clad Structures: Studies in Tectonic Building Practice A. Beim CINARK – Centre for Industrialized Architecture, Institute of Architectural Technology, The Royal Danish Academy of Fine Arts School of Architecture, Copenhagen, Denmark ABSTRACT: With point of departure...... to analyze, compare, and discuss how these various construction solutions point out strategies for development based on fundamentally different mindsets. The research questions address the following issues: How to learn from traditional construction principles: When do we see limitations of tectonic maneuver......, to ask for more restrictive building codes. As an example, in Denmark there are series of increasing demands in the current building legislations that are focused at enhancing the energy performance of buildings, which consequently foster rigid insulation standards and ask for improvement of air...

Study on structural integrity in box structures

International Nuclear Information System (INIS)

Asano, Masayuki; Ueta, Masahiro; Kanaoka, Tadashi; Ikeuchi, Toshiaki; Kodama, Tetsuhiro.

1991-01-01

This study was carried out to give an experimental foundation to the structural integrity of a box structure. Crack growth tests were performed on the reduced scale models, simulating typical portions of the box structure, in air at room temperature. The results show that the amount of crack growth is too small to injure the structural integrity of the models for the postulated loading cycle, and make clear the effective structure against crack growth. (author)

Prosodic structure as a parallel to musical structure

Directory of Open Access Journals (Sweden)

Christopher Cullen Heffner

2015-12-01

Full Text Available What structural properties do language and music share? Although early speculation identified a wide variety of possibilities, the literature has largely focused on the parallels between musical structure and syntactic structure. Here, we argue that parallels between musical structure and prosodic structure deserve more attention. We review the evidence for a link between musical and prosodic structure and find it to be strong. In fact, certain elements of prosodic structure may provide a parsimonious comparison with musical structure without sacrificing empirical findings related to the parallels between language and music. We then develop several predictions related to such a hypothesis.

Irradiation performance of HTGR Biso fertile particles in HFIR experiments HT-17, -18, and -19

International Nuclear Information System (INIS)

Long, E.L. Jr.; Beatty, R.L.; Robbins, J.M.; Kania, M.J.; Eatherly, W.P.

1978-11-01

A series of Biso-coated fertile particles was irradiated in the target facility of the High-Flux Isotope Reactor. The primary objectives of this experiment were to relate the fast-neutron stability of dense propylene-derived pyrocarbons to preferred orientation and to relate irradiation performance to preirradiation characterization values. Coating characterization included x-ray BAF, optical anisotropy, gaseous permeability, small-angle x-ray scattering, and thickness and density determinations. Other objectives were to test Biso-coated large-diameter ThO 2 kernels and coatings derived from propylene diluted with CO 2 rather than argon. Visual examination of the irradiated particles showed that the majority had failed as a result of fast-neutron damage

Beta dose due to monazite sands of Kerala

International Nuclear Information System (INIS)

Massand, O.P.; Venkataraman, G.; Dhairyawan, M.P.

1977-01-01

The heavy black mineral sands of the sea coast of Kerala in India contain patches of monazite in concentrations varying between 0.5 to 5%. Monazite contains about 9.5% of thorium oxide (ThO 2 ) and 0.35% of uranium oxide (U 3 O 8 ). The high natural background radiation of this area had been a matter of concern and reports on the measured gamma radiation levels have appeared. The dose contribution due to beta rays emitted by the materials in the sand has been calculated using Loevinger's formula. The annual beta dose is of the order of 4200 mrad and 740 mrad at a height of 5 and 200 cm respectively from ground level. (author)

Gas lantern mantle: a low activity alpha particle source

International Nuclear Information System (INIS)

Mukherjee, B.; Manzoor, S.

1991-01-01

Commercially available gas lantern mantles contain a substantial amount of radioactive ThO 2 . Gas lantern mantles purchased from a Sydney camping shop were incinerated, deposited as a thin layer on a aluminium planchette, and the emitted alpha spectrum was measured with a silicon surfacer barrier detector. The specific activity of the samples was estimated by high resolution gamma spectroscopy using a high purity germanium detector as well as CR-39 solid state nuclear track detectors. The micro-morphology of the incinerated powder was analysed by scanning electron microscopy. The depth dose and LET distribution of alpha particles in soft tissue were calculated from the energy spectrum. 12 refs., 2 tabs., 5 figs

Nuclear performance of target-blanket assemblies for electronuclear fuel production

International Nuclear Information System (INIS)

Alsmiller, R.G. Jr.; Gabriel, T.A.; Barish, J.

1978-01-01

The results of calculations of high energy transport carried out to evaluate the nuclear performance of several of the designs that have been proposed for electronuclear fuel production are presented. Topics covered include: results for 1-GeV protons and 1-GeV deuterons incident on a lithium target surrounded by a 238 U blanket; results for 1 GeV protons and 1-GeV deuterons incident on a thorium salt; results for 1-GeV protons, incident on a gas-cooled system fueled by either 238 UO 2 or 232 ThO 2 ; and results for protons in the energy range 0.5 to 10 GeV incident on a very large natural uranium target

Vibration-based structural health monitoring of harbor caisson structure

Science.gov (United States)

Lee, So-Young; Lee, So-Ra; Kim, Jeong-Tae

2011-04-01

This study presents vibration-based structural health monitoring method in foundation-structure interface of harbor caisson structure. In order to achieve the objective, the following approaches are implemented. Firstly, vibration-based response analysis method is selected and structural health monitoring (SHM) technique is designed for harbor caisson structure. Secondly, the performance of designed SHM technique for harbor structure is examined by FE analysis. Finally, the applicability of designed SHM technique for harbor structure is evaluated by dynamic tests on a lab-scaled caisson structure.

Structural Behaviour of Reciprocal Structures

DEFF Research Database (Denmark)

Parigi, Dario; Kirkegaard, Poul Henning

2013-01-01

The present paper focuses on the comparison of several two-dimensional and three-dimensional reciprocal configurations. The goal of such comparison is to analyse the structural behaviour when changing the geometric parameters used to describe the geometry of reciprocal structures....

Correlating Structural Order with Structural Rearrangement in Dusty Plasma Liquids: Can Structural Rearrangement be Predicted by Static Structural Information?

Science.gov (United States)

Su, Yen-Shuo; Liu, Yu-Hsuan; I, Lin

2012-11-01

Whether the static microstructural order information is strongly correlated with the subsequent structural rearrangement (SR) and their predicting power for SR are investigated experimentally in the quenched dusty plasma liquid with microheterogeneities. The poor local structural order is found to be a good alarm to identify the soft spot and predict the short term SR. For the site with good structural order, the persistent time for sustaining the structural memory until SR has a large mean value but a broad distribution. The deviation of the local structural order from that averaged over nearest neighbors serves as a good second alarm to further sort out the short time SR sites. It has the similar sorting power to that using the temporal fluctuation of the local structural order over a small time interval.

Significance of structure–soil–structure interaction for closely spaced structures

International Nuclear Information System (INIS)

Roy, Christine; Bolourchi, Said; Eggers, Daniel

2015-01-01

Nuclear facilities typically consist of many closely spaced structures with different sizes and depths of embedment. Seismic response of each structure could be influenced by dynamic structure–soil–structure interaction (SSSI) behavior of adjacent closely spaced structures. This paper examines the impact of SSSI on the in-structure response spectra (ISRS) and peak accelerations of a light structure adjacent to a heavy structure and of a heavy structure adjacent to a similar heavy structure for several soil cases, foundation embedment depths, and separation distances. The impacts of a heavy surface or embedded structure on adjacent ground motions were studied. The analyses demonstrated the adjacent ground motions are sensitive to foundation embedment, soil profile, response frequency, and distance from the structure. Seismic responses of a light structure located near a heavy structure are calculated either by modeling both structures subjected to free field motions, or performing a cascade analysis by considering the light structure model subjected to modified ground motions due to the heavy structure. Cascade SSSI analyses are shown to adequately account for the effect of the heavy structure on the light structure without explicitly modeling both structures together in a single analysis. To further study the influence of SSSI behavior, this paper examines dynamic response of two adjacent heavy structures and compares this response to response of a single heavy structure neglecting adjacent structures. The SSSI responses of the two heavy structures are evaluated for varying soil conditions and structure separation distances using three-dimensional linear SSI analyses and considering anti-symmetry boundary conditions. The analyses demonstrate that the SSSI response of a light or a heavy structure can be influenced by the presence of a nearby heavy structure. Although this study considers linear analysis methodology, the conclusion of SSSI influences on dynamic

Selective alpha autoradiography for monitoring thorium distribution in UO2-ThO2 fuel pellets

International Nuclear Information System (INIS)

Shriwastwa, B.B.; Raghunath, B.; Ghosh, J.K.

1992-01-01

Although natural uranium and thorium decay with similar alpha energies (4.20 and 3.98 MeV), their daughter products have different alpha characteristics. This has been exploited for selective alpha autoradiography for thoria in urania-thoria mixed nuclear fuel pellets. Difficulties in getting sufficient track density in alpha sensitive films due to the very low specific activity of natural uranium and thorium material were overcome by using a special film with annealing and pre-etching treatment. (orig./HP) [de

Structural health monitoring for ship structures

Energy Technology Data Exchange (ETDEWEB)

Farrar, Charles [Los Alamos National Laboratory; Park, Gyuhae [Los Alamos National Laboratory; Angel, Marian [Los Alamos National Laboratory; Bement, Matthew [Los Alamos National Laboratory; Salvino, Liming [NSWC, CADEROCK

2009-01-01

Currently the Office of Naval Research is supporting the development of structural health monitoring (SHM) technology for U.S. Navy ship structures. This application is particularly challenging because of the physical size of these structures, the widely varying and often extreme operational and environmental conditions associated with these ships missions, lack of data from known damage conditions, limited sensing that was not designed specifically for SHM, and the management of the vast amounts of data that can be collected during a mission. This paper will first define a statistical pattern recognition paradigm for SHM by describing the four steps of (1) Operational Evaluation, (2) Data Acquisition, (3) Feature Extraction, and (4) Statistical Classification of Features as they apply to ship structures. Note that inherent in the last three steps of this process are additional tasks of data cleansing, compression, normalization and fusion. The presentation will discuss ship structure SHM challenges in the context of applying various SHM approaches to sea trials data measured on an aluminum multi-hull high-speed ship, the HSV-2 Swift. To conclude, the paper will discuss several outstanding issues that need to be addressed before SHM can make the transition from a research topic to actual field applications on ship structures and suggest approaches for addressing these issues.

Structural priority approach to fluid-structure interaction problems

International Nuclear Information System (INIS)

Au-Yang, M.K.; Galford, J.E.

1981-01-01

In a large class of dynamic problems occurring in nuclear reactor safety analysis, the forcing function is derived from the fluid enclosed within the structure itself. Since the structural displacement depends on the fluid pressure, which in turn depends on the structural boundaries, a rigorous approach to this class of problems involves simultaneous solution of the coupled fluid mechanics and structural dynamics equations with the structural response and the fluid pressure as unknowns. This paper offers an alternate approach to the foregoing problems. 8 refs

Structure soil structure interaction effects: Seismic analysis of safety related collocated concrete structures

International Nuclear Information System (INIS)

Joshi, J.R.

2000-01-01

The Process, Purification and Stack Buildings are collocated safety related concrete shear wall structures with plan dimensions in excess of 100 feet. An important aspect of their seismic analysis was the determination of structure soil structure interaction (SSSI) effects, if any. The SSSI analysis of the Process Building, with one other building at a time, was performed with the SASSI computer code for up to 50 frequencies. Each combined model had about 1500 interaction nodes. Results of the SSSI analysis were compared with those from soil structure interaction (SSI) analysis of the individual buildings, done with ABAQUS and SASSI codes, for three parameters: peak accelerations, seismic forces and the in-structure floor response spectra (FRS). The results may be of wider interest due to the model size and the potential applicability to other deep soil layered sites. Results obtained from the ABAQUS analysis were consistently higher, as expected, than those from the SSI and SSSI analyses using the SASSI. The SSSI effect between the Process and Purification Buildings was not significant. The Process and Stack Building results demonstrated that under certain conditions a massive structure can have an observable effect on the seismic response of a smaller and less stiff structure

An impedance function approach for soil-structure interaction analyses including structure-to-structure interaction effects

International Nuclear Information System (INIS)

Gantayat, A.; Kamil, H.

1981-01-01

The dynamic soil-structure and structure-to-structure interaction effects may be determined in one of the two ways: by modeling the entire soil-structure system by a finite-element model, or by using a frequency-dependent (or frequency-independent) impedance function approach. In seismic design of nuclear power plant structures, the normal practice is to use the first approach because of its simplicity and easy availability of computer codes to perform such analyses. However, in the finite-element approach, because of the size and cost restrictions, the three-dimensional behavior of the entire soil-structure system and the radiation damping in soil are only approximately included by using a two-dimensional finite-element mesh. In using the impedance function approach, the soil-structure analyses can be performed in four steps: (a) determination of the dynamic properties of the fixed base superstructure, (b) determination of foundation and structure impedance matrices and input motions, (c) evaluation of foundation motion, (d) analysis of the fixed base superstructure using computed foundation motion. (orig./RW)

Cooling pipeline disposing structure for large-scaled cryogenic structure

International Nuclear Information System (INIS)

Takahashi, Hiroyuki.

1996-01-01

The present invention concerns an electromagnetic force supporting structure for superconductive coils. As the size of a cryogenic structure is increased, since it takes much cooling time, temperature difference between cooling pipelines and the cryogenic structure is increased over a wide range, and difference of heat shrinkage is increased to increase thermal stresses. Then, in the cooling pipelines for a large scaled cryogenic structure, the cooling pipelines and the structure are connected by way of a thin metal plate made of a material having a heat conductivity higher than that of the material of the structure by one digit or more, and the thin metal plate is bent. The displacement between the cryogenic structure and the cooling pipelines caused by heat shrinkage is absorbed by the elongation/shrinkage of the bent structure of the thin metal plate, and the thermal stresses due to the displacement is reduced. In addition, the heat of the cryogenic structures is transferred by way of the thin metal plate. Then, the cooling pipelines can be secured to the cryogenic structure such that cooling by heat transfer is enabled by absorbing a great deviation or three dimensional displacement due to the difference of the temperature distribution between the cryogenic structure enlarged in the scale and put into the three dimensional shape, and the cooling pipelines. (N.H.)

Soil Retaining Structures : Development of models for structural analysis

NARCIS (Netherlands)

Bakker, K.J.

2000-01-01

The topic of this thesis is the development of models for the structural analysis of soil retaining structures. The soil retaining structures being looked at are; block revetments, flexible retaining walls and bored tunnels in soft soil. Within this context typical structural behavior of these

Structural biology at York Structural Biology Laboratory; laboratory information management systems for structural genomics

Czech Academy of Sciences Publication Activity Database

Dohnálek, Jan

2005-01-01

Roč. 12, č. 1 (2005), s. 3 ISSN 1211-5894. [Meeting of Structural Biologists /4./. 10.03.2005-12.03.2005, Nové Hrady] R&D Projects: GA MŠk(CZ) 1K05008 Keywords : structural biology * LIMS * structural genomics Subject RIV: CD - Macromolecular Chemistry

Structuralism, Post-Structuralism, and Neo-Liberalism: Assessing Foucault's Legacy.

Science.gov (United States)

Olssen, Mark

2003-01-01

Traces Foucault's distinctive commitment to "post-structuralism." Argues that under the influence of Nietzsche, Foucault's approach marks a distinct break with structuralism in several crucial aspects. What results is a materialist post-structuralism that is also distinctively different from the post-structuralism of Derrida, Lyotard,…

Analysis of Pumphouse RCC Frame Structure for Soil Structure Interaction

OpenAIRE

Mr A.S. Thombare; Prof. V.P. Kumbhar; Prof. A.H. Kumbhar

2016-01-01

When structure is built on ground some elements of structure are direct contact with soil. When loads are applied on structure internal forces are developed in both the structure as well as in soil. It results in deformation of both the components which are independent to each other. This are called soil structure interaction. The analysis is done by using (Bentley STAAD.Pro V8i Version 2007) software. The analysis carried out been pump house structure R.C.C. frame structure find ...

Structural behaviour of super-light structures

DEFF Research Database (Denmark)

Bagger, Anne; Hertz, Kristian Dahl

2010-01-01

structural functions: it leads load to the skeleton, it stabilizes the compression members of the skeleton, and it redistributes loads that are not optimal for the skeleton shape. In this paper, FE analysis is used to investigated the behaviour of a series of SLS beams of concrete, under varying stiffness......A new structural concept, called Super-light Structures (SLS), has recently been invented and patented at the Technical University of Denmark. The basic concept of SLS is to construct a skeleton of a stiff and strong material, such as ordinary or high strength concrete, and stabilize this skeleton...... with a lighter and softer material, such as lightweight concrete. The combined use of stiff and light material in SLS results in structures of high stiffness and low weight. The applied technology and the advantages of SLS are elaborated upon in [1] in these proceedings. The present paper focuses...

Effects of non-structural components and soil-structure interaction on the seismic response of framed structures

Science.gov (United States)

Ditommaso, Rocco; Auletta, Gianluca; Iacovino, Chiara; Nigro, Antonella; Carlo Ponzo, Felice

2017-04-01

In this paper, several nonlinear numerical models of reinforced concrete framed structures have been defined in order to evaluate the effects of non-structural elements and soil-structure interaction on the elastic dynamic behaviour of buildings. In the last few years, many and various studies have highlighted the significant effects derived from the interaction between structural and non-structural components on the main dynamic characteristics of a building. Usually, structural and non-structural elements act together, adding both masses and stiffness. The presence of infill panels is generally neglected in the design process of structural elements, although these elements can significantly increase the lateral stiffness of a structure leading to a modification in the dynamic properties. Particularly, at the Damage Limit State (where an elastic behaviour is expected), soil-structure interaction effects and non-structural elements may further affect the elastic natural period of buildings, changing the spectral accelerations compared with those provided by seismic codes in case of static analyses. In this work, a parametric study has been performed in order to evaluate the elastic fundamental period of vibration of buildings as a function of structural morphology (height, plan area, ratio between plan dimensions), infills presence and distribution and soil characteristics. Acknowledgements This study was partially funded by the Italian Department of Civil Protection within the project DPC-RELUIS 2016 - RS4 ''Seismic observatory of structures and health monitoring'' and by the "Centre of Integrated Geomorphology for the Mediterranean Area - CGIAM" within the Framework Agreement with the University of Basilicata "Study, Research and Experimentation in the Field of Analysis and Monitoring of Seismic Vulnerability of Strategic and Relevant Buildings for the purposes of Civil Protection and Development of Innovative Strategies of Seismic Reinforcement".

Effect of gamma radiation on chlorophylls content, net photosynthesis and respiration of Chlorella pyrenoidosa

International Nuclear Information System (INIS)

Martin Moreno, C.; Fernandez Gonzalez, J.

1983-01-01

The effect of five doses of gamma radiation: 10, 100, 500, 1000 and 5000 Gy on chlorophylls content, net photosynthesis and respiration of Chlorella pyrenoidosa has been studied. A decrease in chlorophylls levels is produced after irradiation at 500, 1000 and 5000 Gy, being, at first b chlorophyll affected to a greater extent than a chlorophyll. Net photosynthesis and respiration decline throughout the time of the observation after irradiation, this depressing effect being much more remarkable for the first one. Met photosynthesis inhibition levels of about 30% are got only five hours post irradiation at a dose of 5000 Gy. Radio estimation by low doses, although obtained in some cases for tho 10 Gy dose, has not been statistically confirmed. (Author) 23 refs

Environmental Impact Statement. Space Nuclear Thermal Propulsion Program. Particle Bed reactor Propulsion Technology Development and Validation

Science.gov (United States)

1993-05-01

EcoripoS 20 Reported byt Neretd St. ThOnsac. CSS No. ISO 25 Ftetd Offiace to Lao Vegas. solvels. hoe. ThO Department of ACCAE PCTMC SAA- S/S-?SASSOCIATED...PropulblonProgram LO =01 a a ulib bso "M "Om IS so ffm 0" Idamman wown Swom 0"u "ommi a Say OM "Wame OW Minh itWahm I am a thlvtr- yaw residet ot atd Sawa. I...bW %"-~A, ...Wm pý%JWWd..akopik ~ l~ha.18.711 alae. mn~e OW ~ ffm fM V mW Oft ~ WA&I Alls ..I IMd fW q 1.d 4J 1.20 .dinrapinh- *t.- Php* PW I el.JI*ý

Effect of gamma radiation on chlorophylls content, net photosynthesis and respiration of Chlorella pyrenoidosa; Efecto de la radiacion gamma sobre la fotosintesis neta y la respiracion de Chlorella pyrenoidosa

Energy Technology Data Exchange (ETDEWEB)

Martin, C; Fernandez, J

1983-07-01

The effect of five doses of gamma radiation: 10, 100, 500, 1000 and 5000 Gy on chlorophylls content, net photosynthesis and respiration of Chlorella pyrenoidosa has been studied. A decrease in chlorophylls levels is produced after irradiation at 500, 1000 and 5000 Gy, being, at first b chlorophyll affected to a greater extent than a chlorophyll. Net photosynthesis and respiration decline throughout the time of the observation after irradiation, this depressing effect being much more remarkable for the first one. Met photosynthesis inhibition levels of about 30% are got only five hours post irradiation at a dose of 5000 Gy. Radio estimation by low doses, although obtained in some cases for tho 10 Gy dose, has not been statistically confirmed. (Author) 23 refs.

Origin of blue emission in thorium oxide nanorods

International Nuclear Information System (INIS)

Gupta, Santosh K.; Natarajan, V.; Ghosh, P.S.; Arya, A.

2014-01-01

Thorium oxide, ThO 2 , has long been an important material in the nuclear industry and has more recently found utility in the design of a variety of new materials, including catalysts, electrodes, fuel cell, electrolytes and sensors. Thorium dioxide is an interesting host matrix for a variety of reasons like its low phonon energy (∼450 cm -1 ), which reduces the non-radiative losses. Among all the chemical processes, the micro emulsion processing (reverse micelles synthesis) has been demonstrated as a very versatile and reproducible method. Luminescence of pure metal oxides is usually assigned to crystal lattice defects formed by oxygen vacancies but the obvious experimental evidences for this assumption are absent. Optical properties of stoichiometric and oxygen-deficient thoria have never been investigated previously

Fuel utilization improvement in PWRs using the denatured 233U-Th cycle

International Nuclear Information System (INIS)

Jones, H.M.; Schwenk, G.A.; Toops, E.C.; Yotinen, V.O.

1980-06-01

A number of changes in PWR core design and/or operating strategy were evaluated to assess the fuel utilization improvement achievable by their implementation in a PWR using thorium-based fuel and operating in a recycle mode. The reference PWR for this study was identical to the B and W Standard Plant except that the fuel pellets were of denatured ( 233 U/ 238 U-Th)O 2 . An initial scoping study identified the three most promising improvement concepts as (1) a very tight lattice, (2) thorium blankets, and (3) ThO 2 rods placed in available guide tubes. A conceptual core design incorporating these changes was then developed, and the fuel utilization of this modified design was compared with that of the reference case

Development of numerical models for Monte Carlo simulations of Th-Pb fuel assembly

Directory of Open Access Journals (Sweden)

Oettingen Mikołaj

2017-01-01

Full Text Available The thorium-uranium fuel cycle is a promising alternative against uranium-plutonium fuel cycle, but it demands many advanced research before starting its industrial application in commercial nuclear reactors. The paper presents the development of the thorium-lead (Th-Pb fuel assembly numerical models for the integral irradiation experiments. The Th-Pb assembly consists of a hexagonal array of ThO2 fuel rods and metallic Pb rods. The design of the assembly allows different combinations of rods for various types of irradiations and experimental measurements. The numerical model of the Th-Pb assembly was designed for the numerical simulations with the continuous energy Monte Carlo Burnup code (MCB implemented on the supercomputer Prometheus of the Academic Computer Centre Cyfronet AGH.

Evaluation of potential blanket concepts for a Demonstration Tokamak Hybrid Reactor

International Nuclear Information System (INIS)

Chapin, D.L.; Chi, J.W.H.; Kelly, J.L.

1978-01-01

An evaluation has been made of several different blanket concepts for use in a near-term Demonstration Tokamak Hybrid Reactor (DTHR), whose main objective would be to produce a significant amount of fissile fuel while demonstrating the feasibility of the tokamak hybrid reactor concept. The desirability of a simple design using proven technology plus a proliferation resistant fuel cycle led to the selection of a low temperature and pressure water-cooled, zircaloy clad ThO 2 blanket concept to breed 233 U. The nuclear performance and thermal-hydraulics characteristics of the blanket were evaluated to arrive at a consistent design. The blanket was found to be feasible for producing a significant amount of fissile fuel even with the limited operating conditions and blanket coverage in the DTHR

Perturbative calculations of flow patterns in free convection between coaxial cylinders. Non-linear temperature dependences of the fluid properties

International Nuclear Information System (INIS)

Navarro, J. A.; Madariaga, J. A.; Santamaria, C. M.; Saviron, J. M.

1980-01-01

10 refs. Flow pattern calculations in natural convection between two vertical coaxial cylinders are reported. It is assumed trough the paper. that fluid properties, viscosity, thermal conductivity and density, depend no-linearly on temperature and that the aspects (height/radius) ratio of the cylinders is high. Velocity profiles are calculated trough a perturbative scheme and analytic results for the three first perturbation orders are presented. We outline also an iterative method to estimate the perturbations on the flow patterns which arise when a radial composition gradient is established by external forces in a two-component fluid. This procedure, based on semiempirical basis, is applied to gaseous convection. The influence of the molecules gas properties on tho flow is also discussed. (Author) 10 refs

Perturbative calculations of flow patterns in free convection between coaxial cylinders. Non-linear temperature dependences of the fluid properties; Un metodo de perturbaciones para la obtencion de perfiles de velocidad en conveccion natural entre cilindros coaxiales, dependencias de la temperatura no-lineales de las propiedades del fluido

Energy Technology Data Exchange (ETDEWEB)

Navarro, J A; Madariaga, J A; Santamaria, C M; Saviron, J M

1980-07-01

10 refs. Flow pattern calculations in natural convection between two vertical coaxial cylinders are reported. It is assumed trough the paper. that fluid properties, viscosity, thermal conductivity and density, depend no-linearly on temperature and that the aspects (height/radius) ratio of the cylinders is high. Velocity profiles are calculated trough a perturbative scheme and analytic results for the three first perturbation orders are presented. We outline also an iterative method to estimate the perturbations on the flow patterns which arise when a radial composition gradient is established by external forces in a two-component fluid. This procedure, based on semiempirical basis, is applied to gaseous convection. The influence of the molecules gas properties on tho flow is also discussed. (Author) 10 refs.

The Air Force National Guard and the Air Force Reserve: Points to Ponder for the Future.

Science.gov (United States)

1987-05-01

W Isc, e, trnd-. t.., tho oreassignment of units And indi’.iCiuI’ - , IFI’’.P for’ ’JalnIng commAnds or- functional 1-reas with vih cb h : L’:’ ’ I...8217 omponenlt ~outepat3riiht have. It is unreal ist ic-. to e.pect LhF-: AF"!- F -4 :sqt..ad rur -f lvi g -- : y (11old a 11p1 ai te o b e M t tn j-r,-o-rm a...8217., thio aver’::e res:er’ ist , part cularly the i 1rcrr.w ,nember, has ji-,l- about 1-1sed up -A11 o+ the available S-pac time awa. ft-cm his or her

Special Analysis for the Disposal of the Idaho National Laboratory Unirradiated Light Water Breeder Reactor Rods and Pellets Waste Stream at the Area 5 Radioactive Waste Management Site, Nevada National Security Site, Nye County, Nevada

Energy Technology Data Exchange (ETDEWEB)

None

2014-08-31

The purpose of this special analysis (SA) is to determine if the Idaho National Laboratory (INL) Unirradiated Light Water Breeder Reactor (LWBR) Rods and Pellets waste stream (INEL103597TR2, Revision 2) is suitable for disposal by shallow land burial (SLB) at the Area 5 Radioactive Waste Management Site (RWMS). The INL Unirradiated LWBR Rods and Pellets waste stream consists of 24 containers with unirradiated fabricated rods and pellets composed of uranium oxide (UO2) and thorium oxide (ThO2) fuel in zirconium cladding. The INL Unirradiated LWBR Rods and Pellets waste stream requires an SA because the 229Th, 230Th, 232U, 233U, and 234U activity concentrations exceed the Nevada National Security Site (NNSS) Waste Acceptance Criteria (WAC) Action Levels.

Thermophysical properties of thorium and uranium systems for use in reactor safety analysis

International Nuclear Information System (INIS)

Fink, J.K.; Chasanov, M.G.; Leibowitz, L.

1977-06-01

The data compilation is intended to serve as a preliminary set of thermophysical property values for use in reactor safety analyses of the Th-- 233 U reactor concept. The properties covered include mp, bp, enthalpy, heats of vaporization and fusion, heat capacity, thermal conductivity, density, thermal expansion, emissivity, viscosity, etc. The systems covered are Th, Th 0 . 9 U 0 . 1 , U, ThO 2 , Th 0 . 9 U 0 . 1 O 2 , UO 2 , U 0 . 8 Pu 0 . 2 O 2 , ThC, Th 0 . 9 U 0 . 1 C, UC, U 0 . 8 Pu 0 . 2 C, ThC 2 , Th 0 . 9 U 0 . 1 C 2 , and UC 2 . 5 figures, 10 tables, 150 references

The construction of a radiometric calibration facility at Lanseria Airport, Republic of South Africa

International Nuclear Information System (INIS)

Corner, B.; Smit, C.J.B.

1982-10-01

The construction of standard sources suitable for the calibration of airborne and truck-mounted gamma-spectrometer systems is described. Four sources were built, three of which were doped with preselected quantities of uranium, thorium or potassium. A fourth source was left barren so as to provide a measure of the background radiation in the area. The sources are 8 m in diameter, 0,35 m thick and are recessed into the disused northern portion of runway 17 at Lanseria Airport, north of Johannesburg. Adopted concentrations of the major radioelements in the sources are: 6,24 % K 2 O in the potassium source, 65,0 ppm U 3 O 8 in the uranium source and 150 ppm ThO 2 in the thorium source

The construction of a radiometric calibration facility at Lanseria Airport, Republic of South Africa

International Nuclear Information System (INIS)

Corner, B.; Smit, C.J.B.

1983-08-01

The construction of standard sources suitable for the calibration of airborne and truck-mounted gamma-spectrometer systems is described. Four sources were built, three of which were doped with preselected quantities of uranium, thorium or potassium. A fourth source was left barren so as to provide a measure of the background radiation in the area. The sources are 8 m in diameter, 0,35 m thick and are recessed into the disused northern portion of runway 17 at Lanseria Airport, north of Johannesburg. Adopted concentrations of the major radioelements in the sources are: 6,10 % k 2 O in the potasssium source, 67,0 ppm U 3 O 8 in the uranium source (radiometric), 158 ppm ThO 2 in the thorium source

Analysis of crack propagation in concrete structures with structural information entropy

Institute of Scientific and Technical Information of China (English)

无

2010-01-01

The propagation of cracks in concrete structures causes energy dissipation and release, and also causes energy redistribution in the structures. Entropy can characterize the energy redistribution. To investigate the relation between the propagation of cracks and the entropy in concrete structures, cracked concrete structures are treated as dissipative structures. Structural information entropy is defined for concrete structures. A compact tension test is conducted. Meanwhile, numerical simulations are also carried out. Both the test and numerical simulation results show that the structural information entropy in the structures can characterize the propagation of cracks in concrete structures.

Spatial-structural interaction and strain energy structural optimisation

NARCIS (Netherlands)

Hofmeyer, H.; Davila Delgado, J.M.; Borrmann, A.; Geyer, P.; Rafiq, Y.; Wilde, de P.

2012-01-01

A research engine iteratively transforms spatial designs into structural designs and vice versa. Furthermore, spatial and structural designs are optimised. It is suggested to optimise a structural design by evaluating the strain energy of its elements and by then removing, adding, or changing the

Structural cladding /clad structures:

DEFF Research Database (Denmark)

Beim, Anne

2013-01-01

tendencies, which can be traced in the use of materials, the structural features and the construction details of building systems in selected architectural works. With a particular focus at heavy constructions made of solid wood and masonry, and light weight constructions made of wooden frame structures...... and steel profiles, it is the intention to analyze, compare, and discuss how these various construction solutions point out strategies for development based on fundamentally different mindsets. The research questions address the following issues: How to learn from traditional construction principles: When...

Structural system identification: Structural dynamics model validation

Energy Technology Data Exchange (ETDEWEB)

Red-Horse, J.R.

1997-04-01

Structural system identification is concerned with the development of systematic procedures and tools for developing predictive analytical models based on a physical structure`s dynamic response characteristics. It is a multidisciplinary process that involves the ability (1) to define high fidelity physics-based analysis models, (2) to acquire accurate test-derived information for physical specimens using diagnostic experiments, (3) to validate the numerical simulation model by reconciling differences that inevitably exist between the analysis model and the experimental data, and (4) to quantify uncertainties in the final system models and subsequent numerical simulations. The goal of this project was to develop structural system identification techniques and software suitable for both research and production applications in code and model validation.

A Review of Structure Construction of Silk Fibroin Biomaterials from Single Structures to Multi-Level Structures

Directory of Open Access Journals (Sweden)

Yu Qi

2017-03-01

Full Text Available The biological performance of artificial biomaterials is closely related to their structure characteristics. Cell adhesion, migration, proliferation, and differentiation are all strongly affected by the different scale structures of biomaterials. Silk fibroin (SF, extracted mainly from silkworms, has become a popular biomaterial due to its excellent biocompatibility, exceptional mechanical properties, tunable degradation, ease of processing, and sufficient supply. As a material with excellent processability, SF can be processed into various forms with different structures, including particulate, fiber, film, and three-dimensional (3D porous scaffolds. This review discusses and summarizes the various constructions of SF-based materials, from single structures to multi-level structures, and their applications. In combination with single structures, new techniques for creating special multi-level structures of SF-based materials, such as micropatterning and 3D-printing, are also briefly addressed.

Theoretical model of the probability of fusion between deuterons within deformed lattices with microcracks at room temperature

International Nuclear Information System (INIS)

Frisone, Fulvio

2006-01-01

In this work we wish to demonstrate that a reaction path as the following dislocations, deformations due to thermodynamic stress and, finally, microcrack occurrence, can enhance the process of fusion of the deuterons introduced into the lattice by deuterium loading (F. Frisone, Can variations in temperature influence deuteron interaction within crystalline lattices?, Nuovo Cimento D, 18, 1279 (1996)). In fact, calculating the rate of deuteron-plasmon-deuteron fusion within a microcrack, showed, together with an enhancement of the tunneling effect, an increase of at least 2 - 3 orders of magnitude compared to the probability of fusion on the no deformed lattice. In fact, strong electric fields can take place in the microcrack and the deuterons are accelerated to the energy which is enough for the D-D tunnelling (M. Rabinowitz, High temperature superconductivity and cold fusion, Mod. Phys, Lett. B, 4, 233 (1990); J. Price Hirt and J. Lothe, Theory of Dislocation (McGraw Hill); Z. Phys., 457, 156 (1960)). These phenomena open the way to the theoretical hypothesis that a kind of chain reaction, catalyzed by the microcracks produced in the structure as a result of deuterium loading, can favour tho process of deuteron-plasmon fusion (N. W. Ashcroft and N. D. Mermin (Eds.), Solid State Physics, Chapter 25 (Saunders College, Philadelphia, 1972, pp. 492-509)

Medial structure generation for registration of anatomical structures

DEFF Research Database (Denmark)

Vera, Sergio; Gil, Debora; Kjer, Hans Martin

2017-01-01

structures. Methods for generation of medial structures, however, are prone to the generation of medial artifacts (spurious branches) that traditionally need to be pruned before the medial structure can be used for further computations. The act of pruning can affect main sections of the medial surface......Medial structures (skeletons and medial manifolds) have shown capacity to describe shape in a compact way. In the field of medical imaging, they have been employed to enrich the description of organ anatomy, to improve segmentation, or to describe the organ position in relation to surrounding...

Magnetic multilayer structure

Science.gov (United States)

Herget, Philipp; O'Sullivan, Eugene J.; Romankiw, Lubomyr T.; Wang, Naigang; Webb, Bucknell C.

2016-07-05

A mechanism is provided for an integrated laminated magnetic device. A substrate and a multilayer stack structure form the device. The multilayer stack structure includes alternating magnetic layers and diode structures formed on the substrate. Each magnetic layer in the multilayer stack structure is separated from another magnetic layer in the multilayer stack structure by a diode structure.

Scintillator structures

International Nuclear Information System (INIS)

Cusano, D.A.; Prener, J.S.

1978-01-01

Distributed phosphor scintillator structures providing superior optical coupling to photoelectrically responsive devices together with methods for fabricating said scintillator structures are disclosed. In accordance with one embodiment of the invention relating to scintillator structures, the phosphor is distributed in a 'layered' fashion with certain layers being optically transparent so that the visible wavelength output of the scintillator is better directed to detecting devices. In accordance with another embodiment of the invention relating to scintillator structures, the phosphor is distributed throughout a transparent matrix in a continuous fashion whereby emitted light is more readily transmitted to a photodetector. Methods for fabricating said distributed phosphor scintillator structures are also disclosed. (Auth.)

Seismic characteristics and identification of negative flower structures, positive flower structures, and positive structural inversion

Energy Technology Data Exchange (ETDEWEB)

Harding, T.P.

1985-04-01

Negative and positive flower structures and positive inverted structures imply specific modes of formation, and their distinctive characteristics make them important criteria for the identification of certain structural styles. A negative flower structure from the Andaman Sea consists of a shallow synform bounded by upward-spreading strands of a wrench fault that have mostly normal separations. Paralleling monoclines and oblique, en echelon normal faults flank the divergent wrench fault. A positive flower structure from the Ardmore basin, Oklahoma, consists of a shallow antiform displaced by the upward diverging strands of a wrench fault that have mostly reverse separations. En echelon folds are present on either side of this convergent wrench fault. Positive structural inversion at the Rambutan oil field, South Sumatra basin, has formed a shallow anticlinorium and has partly uplifted the underlying graben. Deeper fault segments bounding the graben have retained their normal fault profiles, but at shallow levels some of these faults have reverse separations.

Structure to self-structuring: infrastructures and processes in neurobehavioural rehabilitation.

Science.gov (United States)

Jackson, Howard F; Hague, Gemma; Daniels, Leanne; Aguilar, Ralph; Carr, Darren; Kenyon, William

2014-01-01

The importance of structure in post-acute brain injury rehabilitation is repeatedly mentioned in clinical practice. However, there has been little exploration of the key elements of structure that promote greater levels of functioning and emotional/behavioural stability and how these elements are optimally integrated within the infrastructure of a rehabilitation service. The nature of structure and why it is helpful is explored initially. Thereafter, the processes involved in transition from externally supported structure to the client 'self-structuring' are described. The infrastructure for facilitating these transitional processes are considered in terms of the design of services for systemic neurorehabilitation encompassing environmental factors (e.g. living environments, vocational and recreational options, step-up services and social milieus), therapeutic alliances (rehabilitation professionals, family, friends), organisational structures (service delivery, rehabilitation coaching, transdisciplinary teams) and rehabilitation philosophies and practice. It is concluded that the process of supporting individuals to transition from the 'structure' of the environment and other people towards self-structuring skills is a critical process in rehabilitation. This is reliant upon a comprehensive and robust organisational infrastructure that can successfully and flexibly integrate the core elements of structure across a transitional pathway towards increased independence and self-structuring.

Lightweight Materials and Structures (LMS): Inflatable Structures

Data.gov (United States)

National Aeronautics and Space Administration —  Current inflatable structures are designed on the restraint layer’s short term properties with a Factor of Safety of 4 due to lack of long-term data on structural...

Structural deformation upon protein-protein interaction: a structural alphabet approach.

Science.gov (United States)

Martin, Juliette; Regad, Leslie; Lecornet, Hélène; Camproux, Anne-Claude

2008-02-28

In a number of protein-protein complexes, the 3D structures of bound and unbound partners significantly differ, supporting the induced fit hypothesis for protein-protein binding. In this study, we explore the induced fit modifications on a set of 124 proteins available in both bound and unbound forms, in terms of local structure. The local structure is described thanks to a structural alphabet of 27 structural letters that allows a detailed description of the backbone. Using a control set to distinguish induced fit from experimental error and natural protein flexibility, we show that the fraction of structural letters modified upon binding is significantly greater than in the control set (36% versus 28%). This proportion is even greater in the interface regions (41%). Interface regions preferentially involve coils. Our analysis further reveals that some structural letters in coil are not favored in the interface. We show that certain structural letters in coil are particularly subject to modifications at the interface, and that the severity of structural change also varies. These information are used to derive a structural letter substitution matrix that summarizes the local structural changes observed in our data set. We also illustrate the usefulness of our approach to identify common binding motifs in unrelated proteins. Our study provides qualitative information about induced fit. These results could be of help for flexible docking.

Structural deformation upon protein-protein interaction: A structural alphabet approach

Directory of Open Access Journals (Sweden)

Lecornet Hélène

2008-02-01

Full Text Available Abstract Background In a number of protein-protein complexes, the 3D structures of bound and unbound partners significantly differ, supporting the induced fit hypothesis for protein-protein binding. Results In this study, we explore the induced fit modifications on a set of 124 proteins available in both bound and unbound forms, in terms of local structure. The local structure is described thanks to a structural alphabet of 27 structural letters that allows a detailed description of the backbone. Using a control set to distinguish induced fit from experimental error and natural protein flexibility, we show that the fraction of structural letters modified upon binding is significantly greater than in the control set (36% versus 28%. This proportion is even greater in the interface regions (41%. Interface regions preferentially involve coils. Our analysis further reveals that some structural letters in coil are not favored in the interface. We show that certain structural letters in coil are particularly subject to modifications at the interface, and that the severity of structural change also varies. These information are used to derive a structural letter substitution matrix that summarizes the local structural changes observed in our data set. We also illustrate the usefulness of our approach to identify common binding motifs in unrelated proteins. Conclusion Our study provides qualitative information about induced fit. These results could be of help for flexible docking.

DNA secondary structures: stability and function of G-quadruplex structures

Science.gov (United States)

Bochman, Matthew L.; Paeschke, Katrin; Zakian, Virginia A.

2013-01-01

In addition to the canonical double helix, DNA can fold into various other inter- and intramolecular secondary structures. Although many such structures were long thought to be in vitro artefacts, bioinformatics demonstrates that DNA sequences capable of forming these structures are conserved throughout evolution, suggesting the existence of non-B-form DNA in vivo. In addition, genes whose products promote formation or resolution of these structures are found in diverse organisms, and a growing body of work suggests that the resolution of DNA secondary structures is critical for genome integrity. This Review focuses on emerging evidence relating to the characteristics of G-quadruplex structures and the possible influence of such structures on genomic stability and cellular processes, such as transcription. PMID:23032257

Hybrid modelling of soil-structure interaction for embedded structures

International Nuclear Information System (INIS)

Gupta, S.; Penzien, J.

1981-01-01

The basic methods currently being used for the analysis of soil-structure interaction fail to properly model three-dimensional embedded structures with flexible foundations. A hybrid model for the analysis of soil-structure interaction is developed in this investigation which takes advantage of the desirable features of both the finite element and substructure methods and which minimizes their undesirable features. The hybrid model is obtained by partitioning the total soil-structure system into a nearfield and a far-field with a smooth hemispherical interface. The near-field consists of the structure and a finite region of soil immediately surrounding its base. The entire near-field may be modelled in three-dimensional form using the finite element method; thus, taking advantage of its ability to model irregular geometries, and the non-linear soil behavior in the immediate vicinity of the structure. (orig./WL)

SSI [soil-structure interactions] and structural benchmarks

International Nuclear Information System (INIS)

Philippacopoulos, A.J.; Miller, C.A.; Costantino, C.J.; Graves, H.

1986-01-01

This paper presents the latest results of the ongoing program entitled, ''Standard Problems for Structural Computer Codes'', currently being worked on at BNL for the USNRC, Office of Nuclear Regulatory Research. During FY 1986, efforts were focussed on three tasks, namely, (1) an investigation of ground water effects on the response of Category I structures, (2) the Soil-Structure Interaction Workshop and (3) studies on structural benchmarks associated with Category I structures. The objective of the studies on ground water effects is to verify the applicability and the limitations of the SSI methods currently used by the industry in performing seismic evaluations of nuclear plants which are located at sites with high water tables. In a previous study by BNL (NUREG/CR-4588), it has been concluded that the pore water can influence significantly the soil-structure interaction process. This result, however, is based on the assumption of fully saturated soil profiles. Consequently, the work was further extended to include cases associated with variable water table depths. In this paper, results related to ''cut-off'' depths beyond which the pore water effects can be ignored in seismic calculations, are addressed. Comprehensive numerical data are given for soil configurations typical to those encountered in nuclear plant sites. These data were generated by using a modified version of the SLAM code which is capable of handling problems related to the dynamic response of saturated soils

Concrete structures. Contribution to the safety assessment of existing structures

Directory of Open Access Journals (Sweden)

D. COUTO

Full Text Available The safety evaluation of an existing concrete structure differs from the design of new structures. The partial safety factors for actions and resistances adopted in the design phase consider uncertainties and inaccuracies related to the building processes of structures, variability of materials strength and numerical approximations of the calculation and design processes. However, when analyzing a finished structure, a large number of unknown factors during the design stage are already defined and can be measured, which justifies a change in the increasing factors of the actions or reduction factors of resistances. Therefore, it is understood that safety assessment in existing structures is more complex than introducing security when designing a new structure, because it requires inspection, testing, analysis and careful diagnose. Strong knowledge and security concepts in structural engineering are needed, as well as knowledge about the materials of construction employed, in order to identify, control and properly consider the variability of actions and resistances in the structure. With the intention of discussing this topic considered complex and diffuse, this paper presents an introduction to the safety of concrete structures, a synthesis of the recommended procedures by Brazilian standards and another codes, associated with the topic, as well a realistic example of the safety assessment of an existing structure.

Space Structure Development

Science.gov (United States)

Smith, Thomas

2015-01-01

The duration of my Summer 2015 Internship Tour at NASA's Johnson Space Center was spent working in the Structural Engineering Division's Structures Branch. One of the two main roles of the Structures Branch, ES2, is to ensure the structural integrity of spacecraft vehicles and the structural subsystems needed to support those vehicles. The other main objective of this branch is to develop the lightweight structures that are necessary to take humans beyond Low-Earth Orbit. Within ES2, my four projects involved inflatable space structure air bladder material testing; thermal and impact material testing for spacecraft windows; structural analysis on a joint used in the Boeing CST-100 airbag system; and an additive manufacturing design project.

Structural Health Monitoring Based on Combined Structural Global and Local Frequencies

Directory of Open Access Journals (Sweden)

Jilin Hou

2014-01-01

Full Text Available This paper presents a parameter estimation method for Structural Health Monitoring based on the combined measured structural global frequencies and structural local frequencies. First, the global test is experimented to obtain the low order modes which can reflect the global information of the structure. Secondly, the mass is added on the member of structure to increase the local dynamic characteristic and to make the member have local primary frequency, which belongs to structural local frequency and is sensitive to local parameters. Then the parameters of the structure can be optimized accurately using the combined structural global frequencies and structural local frequencies. The effectiveness and accuracy of the proposed method are verified by the experiment of a space truss.

Nonlinear seismic soil-structure interaction analysis of nuclear power plant structures

International Nuclear Information System (INIS)

Khanna, J.K.; Setlur, A.V.; Pathak, D.V.

1977-01-01

The heterogeneous and nonlinear soil medium and the detailed three-dimensional structure are synthesized to determine the seismic response to soil-structure systems. The approach is particularly attractive in a design office environment since it: a) leads to interactive motion at the soil-structure interface; b) uses existing public domain programs such as SAPIV, LUSH and FLUSH with marginal modifications; and c) meets current regulatory requirements for soil-structure interaction analysis. Past methods differ from each other depending on the approach adopted for soil and structure representations and procedures for solving the governing differential equations. Advantages and limitations of these methods are reviewed. In the current approach, the three-dimensional structure is represented by the dynamic characteristics of its fixed base condition. This representation is ideal when structures are designed to be within elastic range. An important criterion is the design of the nuclear power plant structures. Model damping coefficients are varied to reflect the damping properties of different structural component materials. The detailed structural model is systematically reduced to reflect important dynamic behavior with simultaneous storing of intermediate information for retrieval of detailed structural response. Validity of the approach has been established with simple numerical experiments. (Auth.)

Structural Evaluation Procedures for Heavy Wood Truss Structures

National Research Council Canada - National Science Library

Issa, Mohsen

1998-01-01

.... An evaluation procedure for wood structures differs from conventional methods used in steel, concrete, and masonry structures because, in wood construction, the allowable stresses used in design...

Scintillator structure

International Nuclear Information System (INIS)

Cusano, D.A.; Prener, J.S.

1979-01-01

A scintillator structure comprises at least one layer of transparent fused quartz with a phosphor coating on one or both sides adjacent to at least one transparent layer of epoxy resin which directs light from the phosphor to a detector. The phosphor layer may be formed from a powder optionally with a binder, a single crystal or a melt, or by evaporation or sintering. A plurality of multiple layers may be used or the structure tilted for greater absorption. The structure may be surrounded by another such structure optionally operating in cascade with the first. Many phosphors are specified. A scintillator structure comprises phosphor particles dispersed in epoxy resin or copoly imide-silicone and cast in a multi-compartment box with long sides transparent to X-rays and dividers opaque to X-rays. (UK)

Design optimisation of the ATLAS Barrel Toroid structure - the warm structure

International Nuclear Information System (INIS)

Daeel, A.; Desvard, J-P.; Pabot, Y.; Sun, Z.; Hille, H. van; Vedrine, P.

2001-01-01

The magnetic bending of muon tracks for the ATLAS Muon Spectrometer is provided by the large air-core toroid magnets. The Barrel Toroid structure, named the warm structure, is an open structure inside which the muon chambers are installed. The physics performance of the muon spectrometer imposes stringent requirements on the design of the warm structure. It should support the muon chambers with required precision and stability, the deformation of the structure must be minimised. At the same time, the quantities of the materials used in the structure must also be minimised. Through extensive structural analyses, the design optimisation has been achieved to fit with the physics requirements. This paper gives an overview on the design considerations of the warm structure

Spectra of Th/Ar and U/Ne hollow cathode lamps for spectrograph calibration

Science.gov (United States)

Nave, Gillian; Shlosberg, Ariel; Kerber, Florian; Den Hartog, Elizabeth; Neureiter, Bianca

2018-01-01

Low-current Th/Ar hollow cathode lamps have long been used for calibration of astronomical spectrographs on ground-based telescopes. Thorium is an attractive element for calibration as it has a single isotope, has narrow spectral lines, and has a dense spectrum covering the whole of the visible region. However, the high density of the spectrum that makes it attractive for calibrating high-resolution spectrographs is a detriment for lower resolution spectrographs and this is not obvious by examination of existing linelists. In addition, recent changes in regulations regarding the handling of thorium have led to a degradation in the quality of Th/Ar calibration lamps, with contamination by molecular ThO lines that are strong enough to obscure the calibration lines of interest.We are pursuing two approaches to these problems. First, we have expanded and improved the NIST Standard Reference Database 161, "Spectrum of Th-Ar Hollow Cathode Lamps" to cover the region 272 nm to 5500 nm. Spectra of hollow cathode lamps at up to 3 different currents can now be displayed simultaneously. Interactive zooming and the ability to convolve any of the spectra with a Gaussian or uploaded instrument profile enable the user to see immediately what the spectrum would look like at the particular resolution of their spectrograph. Second, we have measured the spectrum of a recent, contaminated Th/Ar hollow cathode lamp using a high-resolution Echelle spectrograph (Madison Wisconsin) at a resolving power (R~ 250,000). This significantly exceeds the resolving power of most astronomical spectrographs and resolves many of the molecular lines of ThO. With these spectra we are measuring and calibrating the positions of these molecular lines in order to make them suitable for spectrograph calibration.In the near infrared region, U/Ne hollow cathode lamps give a higher density of calibration lines than Th/Ar lamps and will be implemented on the upgraded CRIRES+ spectrograph on ESO’s Very Large

Experimental studies of thorium ion implantation from pulse laser plasma into thin silicon oxide layers

Science.gov (United States)

Borisyuk, P. V.; Chubunova, E. V.; Lebedinskii, Yu Yu; Tkalya, E. V.; Vasilyev, O. S.; Yakovlev, V. P.; Strugovshchikov, E.; Mamedov, D.; Pishtshev, A.; Karazhanov, S. Zh

2018-05-01

We report the results of experimental studies related to implantation of thorium ions into thin silicon dioxide by pulsed plasma flux expansion. Thorium ions were generated by laser ablation from a metal target, and the ionic component of the laser plasma was accelerated in an electric field created by the potential difference (5, 10 and 15 kV) between the ablated target and a SiO2/Si (0 0 1) sample. The laser ablation system installed inside the vacuum chamber of the electron spectrometer was equipped with a YAG:Nd3  +  laser having a pulse energy of 100 mJ and time duration of 15 ns in the Q-switched regime. The depth profile of thorium atoms implanted into the 10 nm thick subsurface areas together with their chemical state as well as the band gap of the modified silicon oxide at different conditions of implantation processes were studied by means of x-ray photoelectron spectroscopy and reflected electron energy loss spectroscopy methods. Analysis of the chemical composition showed that the modified silicon oxide film contains complex thorium silicates. Depending on the local concentration of thorium atoms, the experimentally established band gaps were located in the range 6.0–9.0 eV. Theoretical studies of the optical properties of the SiO2 and ThO2 crystalline systems were performed by ab initio calculations within hybrid functional. The optical properties of the SiO2/ThO2 composite were interpreted on the basis of the Bruggeman effective medium approximation. A quantitative assessment of the yield of isomeric nuclei in ‘hot’ laser plasma at the early stages of expansion was performed. The estimates made with experimental results demonstrated that the laser implantation of thorium ions into the SiO2 matrix can be useful for further research of low-lying isomeric transitions in a 229Th isotope with energy of 7.8 +/- 0.5 eV.

The key design features of the Indian advanced heavy water reactor

International Nuclear Information System (INIS)

Sinha, R.K.; Kakodkar, A.; Anand, A.K.; Venkat Raj, V.; Balakrishnan, K.

1999-01-01

The 235 MWe Indian Advanced Heavy Water Reactor (AHWR) is a vertical, pressure tube type, boiling light water cooled reactor. The three key specific features of design of the AHWR, having a large impact on its viability, safety and economics, relate to its reactor physics, coolant channel, and passive safety features. The reactor physics design is tuned for maximising use of thorium based fuel, and achieving a slightly negative void coefficient of reactivity. The fulfilment of these requirements has been possible through use of PuO 2 -ThO 2 MOX, and ThO 2 -U 233 O 2 MOX in different pins of the same fuel cluster, and use of a heterogeneous moderator consisting of pyrolytic carbon and heavy water in 80%-20% volume ratio. The coolant channels of AHWR are designed for easy replaceability of pressure tubes, during normal maintenance shutdowns. The removal of pressure tube along with bottom end-fitting, using rolled joint detachment technology, can be done in AHWR coolant channels without disturbing the top end-fitting, tail pipe and feeder connections, and all other appendages of the coolant channel. The AHWR incorporates several passive safety features. These include core heat removal through natural circulation, direct injection of Emergency Core Coolant System (ECCS) water in fuel, passive systems for containment cooling and isolation, and availability of a large inventory of borated water in overhead Gravity Driven Water Pool (GDWP) to facilitate sustenance of core decay heat removal, ECCS injection, and containment cooling for three days without invoking any active systems or operator action. Incorporation of these features has been done together with considerable design simplifications, and elimination of several reactor grade equipment. A rigorous evaluation of feasibility of AHWR design concept has been completed. The economy enhancing aspects of its key design features are expected to compensate for relative complexity of the thorium fuel cycle activities

A Comparative Study of Potential Evapotranspiration Estimation by Eight Methods with FAO Penman–Monteith Method in Southwestern China

Directory of Open Access Journals (Sweden)

Dengxiao Lang

2017-09-01

Full Text Available Potential evapotranspiration (PET is crucial for water resources assessment. In this regard, the FAO (Food and Agriculture Organization–Penman–Monteith method (PM is commonly recognized as a standard method for PET estimation. However, due to requirement of detailed meteorological data, the application of PM is often constrained in many regions. Under such circumstances, an alternative method with similar efficiency to that of PM needs to be identified. In this study, three radiation-based methods, Makkink (Mak, Abtew (Abt, and Priestley–Taylor (PT, and five temperature-based methods, Hargreaves–Samani (HS, Thornthwaite (Tho, Hamon (Ham, Linacre (Lin, and Blaney–Criddle (BC, were compared with PM at yearly and seasonal scale, using long-term (50 years data from 90 meteorology stations in southwest China. Indicators, viz. (videlicet Nash–Sutcliffe efficiency (NSE, relative error (Re, normalized root mean squared error (NRMSE, and coefficient of determination (R2 were used to evaluate the performance of PET estimations by the above-mentioned eight methods. The results showed that the performance of the methods in PET estimation varied among regions; HS, PT, and Abt overestimated PET, while others underestimated. In Sichuan basin, Mak, Abt and HS yielded similar estimations to that of PM, while, in Yun-Gui plateau, Abt, Mak, HS, and PT showed better performances. Mak performed the best in the east Tibetan Plateau at yearly and seasonal scale, while HS showed a good performance in summer and autumn. In the arid river valley, HS, Mak, and Abt performed better than the others. On the other hand, Tho, Ham, Lin, and BC could not be used to estimate PET in some regions. In general, radiation-based methods for PET estimation performed better than temperature-based methods among the selected methods in the study area. Among the radiation-based methods, Mak performed the best, while HS showed the best performance among the temperature

Aerospace structural design process improvement using systematic evolutionary structural modeling

Science.gov (United States)

Taylor, Robert Michael

2000-10-01

A multidisciplinary team tasked with an aircraft design problem must understand the problem requirements and metrics to produce a successful design. This understanding entails not only knowledge of what these requirements and metrics are, but also how they interact, which are most important (to the customer as well as to aircraft performance), and who in the organization can provide pertinent knowledge for each. In recent years, product development researchers and organizations have developed and successfully applied a variety of tools such as Quality Function Deployment (QFD) to coordinate multidisciplinary team members. The effectiveness of these methods, however, depends on the quality and fidelity of the information that team members can input. In conceptual aircraft design, structural information is of lower quality compared to aerodynamics or performance because it is based on experience rather than theory. This dissertation shows how advanced structural design tools can be used in a multidisciplinary team setting to improve structural information generation and communication through a systematic evolution of structural detail. When applied to conceptual design, finite element-based structural design tools elevate structural information to the same level as other computationally supported disciplines. This improved ability to generate and communicate structural information enables a design team to better identify and meet structural design requirements, consider producibility issues earlier, and evaluate structural concepts. A design process experiment of a wing structural layout in collaboration with an industrial partner illustrates and validates the approach.

Discrete Optimization of Internal Part Structure via SLM Unit Structure-Performance Database

Directory of Open Access Journals (Sweden)

Li Tang

2018-01-01

Full Text Available The structural optimization of the internal structure of parts based on three-dimensional (3D printing has been recognized as being important in the field of mechanical design. The purpose of this paper is to present a creation of a unit structure-performance database based on the selective laser melting (SLM, which contains various structural units with different functions and records their structure and performance characteristics so that we can optimize the internal structure of parts directly, according to the database. The method of creating the unit structure-performance database was introduced in this paper and several structural units of the unit structure-performance database were introduced. The bow structure unit was used to show how to create the structure-performance database of the unit as an example. Some samples of the bow structure unit were designed and manufactured by SLM. These samples were tested in the WDW-100 compression testing machine to obtain their performance characteristics. After this, the paper collected all data regarding unit structure parameters, weight, performance characteristics, and other data; and, established a complete set of data from the bow structure unit for the unit structure-performance database. Furthermore, an aircraft part was reconstructed conveniently to be more lightweight according to the unit structure-performance database. Its weight was reduced by 36.8% when compared with the original structure, while the strength far exceeded the requirements.

Structure of simple liquids; Structure des liquides simples

Energy Technology Data Exchange (ETDEWEB)

Blain, J F [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-07-01

The results obtained by application to argon and sodium of the two important methods of studying the structure of liquids: scattering of X-rays and neutrons, are presented on one hand. On the other hand the principal models employed for reconstituting the structure of simple liquids are exposed: mathematical models, lattice models and their derived models, experimental models. (author) [French] On presente d'une part les resultats obtenus par application a l'argon et au sodium des deux principales methodes d'etude de la structure des liquides: la diffusion des rayons X et la diffusion des neutrons; d'autre part, les principaux modeles employes pour reconstituer la structure des liquides simples sont exposes: modeles mathematiques, modeles des reseaux et modeles derives, modeles experimentaux. (auteur)

Structural biology by NMR: structure, dynamics, and interactions.

Directory of Open Access Journals (Sweden)

Phineus R L Markwick

2008-09-01

Full Text Available The function of bio-macromolecules is determined by both their 3D structure and conformational dynamics. These molecules are inherently flexible systems displaying a broad range of dynamics on time-scales from picoseconds to seconds. Nuclear Magnetic Resonance (NMR spectroscopy has emerged as the method of choice for studying both protein structure and dynamics in solution. Typically, NMR experiments are sensitive both to structural features and to dynamics, and hence the measured data contain information on both. Despite major progress in both experimental approaches and computational methods, obtaining a consistent view of structure and dynamics from experimental NMR data remains a challenge. Molecular dynamics simulations have emerged as an indispensable tool in the analysis of NMR data.

Task structure, need for structure, and creativity

NARCIS (Netherlands)

Rietzschel, Eric; Slijkhuis, Marjette; Van Yperen, Nico W.

2014-01-01

Although creativity is often seen as requiring spontaneity and flexibility, recent work suggests that there is creative potential in a structured and systematic approach as well. In a series of four experiments, we show that when Personal Need for Structure (PNS) is high, either chronic (Study 1) or

Structural design of nuclear power plant using stiffened steel plate concrete structure

International Nuclear Information System (INIS)

Moon, Ilhwan; Kim, Sungmin; Mun, Taeyoup; Kim, Keunkyeong; Sun, Wonsang

2009-01-01

Nuclear power is an alternative energy source that is conducive to mitigate the environmental strains. The countries having nuclear power plants are encouraging research and development sector to find ways to construct safer and more economically feasible nuclear power plants. Modularization using Steel Plate Concrete(SC) structure has been proposed as a solution to these efforts. A study of structural modules using SC structure has been performed for shortening of construction period and enhancement of structural safety of NPP structures in Korea. As a result of the research, the design code and design techniques based on limit state design method has been developed. The design code has been developed through various structural tests and theoretical studies, and it has been modified by application design of SC structure for NPP buildings. The code consists of unstiffened SC wall design, stiffened SC wall design, Half-SC slab design, stud design, connection design and so on. The stiffened steel plate concrete(SSC) wall is SC structure whose steel plates with ribs are composed on both sides of the concrete wall, and this structure was developed for improved constructability and safety of SC structure. This paper explains a design application of SC structure for a sample building specially devised to reflect all of major structural properties of main buildings of APR1400. In addition, Stiffening effect of SSC structure is evaluated and structural efficiency of SSC structure is verified in comparison with that of unstiffened SC structure. (author)

Strategy implemented through structuring and new structures

DEFF Research Database (Denmark)

Nielsen, Renate

Research objective: With the purpose of generating a new understanding of how development in organisations take place, an interpretive perspective at continuous processes in organisations will be applied: more specifically at how organisational interpretation forms an organisation's strategy...... and how the strategy is implemented through structuring, new structures and routines....

Atomic-level structure and structure-property relationship in metallic glass

Science.gov (United States)

Cheng, Yongqiang

One of the key tasks in material science is to understand the structure and structure-property relationship. The recently emerging bulk metallic glasses (BMGs) have demonstrated unique properties, especially intriguing mechanical properties such as their high strength and high propensity to localize deformation in shear bands. However, a comprehensive understanding of the structure of BMGs has been hindered by the complexity of these amorphous materials. Even more challenging is the structure-property correlation, which has been well established in crystals but has been seriously lacking for BMGs. This thesis presents a systematic study of the atomic-level structures of two representative BMGs, Cu-Zr and Cu-Zr-Al. The interpenetrating Cu-centered icosahedral clusters have been identified to be the primary structural feature. The fraction of icosahedra increases with increasing Cu or Al contents, and with decreasing cooling rate. The effect of Al in improving the icosahedral order is two-fold: the geometric effect due to the atomic-size mismatch and the chemical effect originated from the Cu-Al bond shortening. The resolved structure is used to study the structure-property relationship. The full icosahedra are found to be responsible for the dynamical slowdown of the supercooled liquid, which underlies the non-Arrhenius behavior, and explains the composition dependence of glass transition temperature, glass forming ability, and the room temperature strength. By simulated deformation, the initiation of plasticity and tendency for strain localization are also investigated. The full icosahedra are found to be the most rigid and resistant cluster with solid-like character, while the unstable clusters with liquid-like character serve as the fertile sites for initiating shear transformations. In addition, the elastic moduli are calculated and analyzed, and the origins of the different configurational dependence of shear modulus (G) and bulk modulus ( B) are explained. The

Structuralism.

Science.gov (United States)

Piaget, Jean

Provided is an overview of the analytical method known as structuralism. The first chapter discusses the three key components of the concept of a structure: the view of a system as a whole instead of so many parts; the study of the transformations in the system; and the fact that these transformations never lead beyond the system but always…

Setting up a glove box adoptable high temperature furnace for actinide chemistry research

International Nuclear Information System (INIS)

Sali, S.K.; Keskar, Meera; Kannan, S.

2017-01-01

Thermophysical and thermochemical properties of fuel materials and the compounds formed by the interaction of fuel with fission products and cladding materials are very important for the understanding of fuel behaviour under reactor operation condition. In order to find out various compounds formed during reactor operating condition, number of phase mixtures containing UO_2, ThO_2, PuO_2 and (U, Pu)O_2 with fission products and cladding materials have to be prepared and characterized using XRD, HTXRD, DSC, TG/DTA techniques. For carrying out solid-state reactions, the reaction mixtures have to be heated in different atmospheres between 1000 to 1600°C.Since, actinides are used in these studies, a control atmosphere high temperature furnace inside a glove box with appropriate safety features is indispensable

Rapid chemical analysis of allanite

International Nuclear Information System (INIS)

Nishiyama, Goro; Hayashi, Hiroshi

1981-01-01

Rapid chemical analysis of allanite was studied by atomic absorption spectrophotometry. Powdered sample was fused with mixture of sodium carbonate anhydrous and borax (4 : 1 weight) in platinum crucible and sample solution was prepared. SiO 2 , Fe 2 O 3 , Al 2 O 3 , MnO and rare earth metals were determined by atomic absorption spectrophotometry, CaO, MgO and Ce 2 O 3 by titration, ThO 2 by colorimetry, and La 2 O 3 by flame photometry respectively. For sample solution treated with hydrofluoric acid and sulfuric acid. Na 2 O and K 2 O were determined by atomic absorption spectrophotometry, TiO 2 and P 2 O 5 by colorimetry. Chemical analyses for four samples were carried out and gave consistent results. (author)

OCCURRENCE OF MORDENITE NEAR BYŠTA: THE BASIC CHARAKTERISTICS AND TECHNOLOGICAL PARAMETERS

Directory of Open Access Journals (Sweden)

Bačo Pavel

1997-10-01

Full Text Available In eastern Slovakia, NE from Byšta village, mordenit has been found in a perlitized glassy margin of the rhyolite rock body. The mordenite which makes up to 40 - 60 % of tho rock, is charakteristically needle - like and fibrous, and forms bundles of fibres and needles inside the geodes with outershells of devitrified volca-nic glass. The mordenite itself exhibits a high chemical and thermal stability. The zeolitized rock after proper mechani- cal and thermal treatment has been succesfully studied in the laboratory as adsorbent of water vapor and other gases from air. Using the ion - exchange properties, the treated rock was used in the experiments for the removal of some cations from low-lever waste waters ( Cs+, Pb2+, Fe3+, Hg2+ .

Conversion of fuel hulls to zirconate ion exchangers for stabilization of wastes from the thorium fuel cycle

International Nuclear Information System (INIS)

Levine, H.S.

1978-01-01

A conceptual reprocessing and waste management scheme for Zircaloy clad ThO 2 fuel was formulated to eliminate problems associated with concurrent dissolution of fuel and cladding in the conventional chop-leach headend step. These problems are avoided by use of a modified headend step to form oxide fuel and cladding process streams. A chlorinating agent then converts the cladding hulls and adhering fuel into volatile and nonvolatile chloride fractions. The former product is processed, by use of the Zircaloy conversion process, to form an inorganic ion exchange material and combined with HLLW from subsequent fuel reprocessing to form a stable and refractory waste form. The nonvolatile chloride fraction would be recovered, processed to remove chloride ions, and recombined with the main oxide fuel process stream for further treatment by use of the Thorex process

Postirradiation examination of recycle test elements from the Peach Bottom Reactor

International Nuclear Information System (INIS)

Tiegs, T.N.; Long, E.L. Jr.

1978-12-01

The Recycle Test Elements were a series of tests of High-Temperature Gas-Cooled Reactor fuels irradiated in Core 2 of the Peach Bottom Unit 1 Reactor. They tested a wide variety of fissile and fertile fuel types of prime interest when the tests were designed. The fuel types included UO 2 , UC 2 , (2Th,U)O 2 , (4Th,U)O 2 , ThC 2 , and ThO 2 . The mixed thorium--uranium oxides and the pure thorium oxide were tested as Biso-coated particles only, while the others were tested as both Biso- and Triso-coated particles. The Biso coatings on the fissile kernels contained the fission products inadequately but on the fertile kernels they did so acceptably. The results from accelerated and real-time tests on the particle types agreed well

Production and release of the fission gas in (Th U)O2 fuel rods

International Nuclear Information System (INIS)

Dias, Marcio S.

1982-06-01

The volume, composition and release of the fission gas products were caculated for (Th, U)O 2 fuel rods. The theorectical calculations were compared with experimental results available on the literature. In ThO 2 + 5% UO 2 fuel rods it will be produced approximated 5% more fission gas as compared to UO 2 fuel rods. The fission gas composition or Xe to Kr ratio has showed a decreasing fuel brunup dependence, in opposition to that of UO 2 . Under the same fuel rod operational conditions, the (Th, U)O 2 fission gas release will be smaller as compared to UO 2 . This behaviour of (Th, U)O 2 fuel comes from smallest gas atom difusivity and higher activation energies of the processes that increase the fission gas release. (Author) [pt

Escape tectonism in the Gulf of Thailand: Paleogene left-lateral pull-apart rifting in the Vietnamese part of the Malay Basin

DEFF Research Database (Denmark)

Fyhn, Michael B.W.; Boldreel, Lars Ole; Nielsen, Lars H

2010-01-01

The Malay Basin represents one of the largest rift basins of SE Asia. Based on a comprehensive 2-D seismic database tied to wells covering mainly Vietnamese acreage, the evolution of the Vietnamese part of the basin is outlined and a new tectonic model is proposed for the development of the basin....... The Vietnamese part of the Malay Basin comprises a large and deep Paleogene pull-apart basin formed through Middle or Late Eocene to Oligocene left-lateral strike-slip along NNW-trending fault zones. The Tho Chu Fault Zone constitutes a significant Paleogene left-lateral strike-slip zone most likely associated......–Strending faults in the central part of the basin. However, the lack of inversion in Vietnamese territory only seems to merit a few kilometers of dextral inversion....

[The low consumption of outpatient medical care in the department of Ardennes (France) (author's transl)].

Science.gov (United States)

Lebrun, T; Sailly, J C

1982-01-01

The purpose of the research explained in this article was to build up a methodology which allows to set up a map of low consumption of outpatient medical care and to find out to which extent the low recorded demand is attributable tho the medical aids supply. French National Health Service files were the basic data for this research which was led into the department of Ardennes. First and foremost the investigation was to identify on a district level with low consumer families after having eliminated demands' factors. Thus one could set up maps of low consumption in comparison with maps of low prescription. The investigation showed that low consumer families live generally in the cantons of low medical care consumption concerned mainly with low medical aids suppliers.

Building structures

CERN Document Server

Ambrose, James

2011-01-01

James Ambrose is Editor of the Parker/Ambrose Series of Simplified Design Guides. He practiced as an architect in California and Illinois and as a structural engineer in Illinois. He was a professor of architecture at the University of Southern California. Patrick Tripeny is an Associate Professor, former director of the School of Architecture, and the current Director of the Center for Teaching and Learning Excellence at the University of Utah. He is a licensed architect in California. He has been the recipient of a number of teaching awards at the local and national level for his work in teaching structures and design. With James Ambrose, he is the coauthor of Simplified Engineering for Architects and Builders, Eleventh Edition; Simplified Design of Steel Structures, Eighth Edition; Simplified Design of Concrete Structures, Eighth Edition; and Simplified Design of Wood Structures, Sixth Edition, all published by Wiley.

Robustness of Structures

DEFF Research Database (Denmark)

Faber, Michael Havbro; Vrouwenvelder, A.C.W.M.; Sørensen, John Dalsgaard

2011-01-01

In 2005, the Joint Committee on Structural Safety (JCSS) together with Working Commission (WC) 1 of the International Association of Bridge and Structural Engineering (IABSE) organized a workshop on robustness of structures. Two important decisions resulted from this workshop, namely...... ‘COST TU0601: Robustness of Structures’ was initiated in February 2007, aiming to provide a platform for exchanging and promoting research in the area of structural robustness and to provide a basic framework, together with methods, strategies and guidelines enhancing robustness of structures...... the development of a joint European project on structural robustness under the COST (European Cooperation in Science and Technology) programme and the decision to develop a more elaborate document on structural robustness in collaboration between experts from the JCSS and the IABSE. Accordingly, a project titled...

Improving the accuracy of protein secondary structure prediction using structural alignment

Directory of Open Access Journals (Sweden)

Gallin Warren J

2006-06-01

Full Text Available Abstract Background The accuracy of protein secondary structure prediction has steadily improved over the past 30 years. Now many secondary structure prediction methods routinely achieve an accuracy (Q3 of about 75%. We believe this accuracy could be further improved by including structure (as opposed to sequence database comparisons as part of the prediction process. Indeed, given the large size of the Protein Data Bank (>35,000 sequences, the probability of a newly identified sequence having a structural homologue is actually quite high. Results We have developed a method that performs structure-based sequence alignments as part of the secondary structure prediction process. By mapping the structure of a known homologue (sequence ID >25% onto the query protein's sequence, it is possible to predict at least a portion of that query protein's secondary structure. By integrating this structural alignment approach with conventional (sequence-based secondary structure methods and then combining it with a "jury-of-experts" system to generate a consensus result, it is possible to attain very high prediction accuracy. Using a sequence-unique test set of 1644 proteins from EVA, this new method achieves an average Q3 score of 81.3%. Extensive testing indicates this is approximately 4–5% better than any other method currently available. Assessments using non sequence-unique test sets (typical of those used in proteome annotation or structural genomics indicate that this new method can achieve a Q3 score approaching 88%. Conclusion By using both sequence and structure databases and by exploiting the latest techniques in machine learning it is possible to routinely predict protein secondary structure with an accuracy well above 80%. A program and web server, called PROTEUS, that performs these secondary structure predictions is accessible at http://wishart.biology.ualberta.ca/proteus. For high throughput or batch sequence analyses, the PROTEUS programs

Shell-like structures

CERN Document Server

Altenbach, Holm

2011-01-01

In this volume, scientists and researchers from industry discuss the new trends in simulation and computing shell-like structures. The focus is put on the following problems: new theories (based on two-dimensional field equations but describing non-classical effects), new constitutive equations (for materials like sandwiches, foams, etc. and which can be combined with the two-dimensional shell equations), complex structures (folded, branching and/or self intersecting shell structures, etc.) and shell-like structures on different scales (for example: nano-tubes) or very thin structures (similar

Basic structural dynamics

CERN Document Server

Anderson, James C

2012-01-01

A concise introduction to structural dynamics and earthquake engineering Basic Structural Dynamics serves as a fundamental introduction to the topic of structural dynamics. Covering single and multiple-degree-of-freedom systems while providing an introduction to earthquake engineering, the book keeps the coverage succinct and on topic at a level that is appropriate for undergraduate and graduate students. Through dozens of worked examples based on actual structures, it also introduces readers to MATLAB, a powerful software for solving both simple and complex structural d

Some considerations on the dynamic structure-soil-structure interactions analysis

International Nuclear Information System (INIS)

Matthees, W.

1979-01-01

A mixed method has been developed for the approximate analysis of soil-structure or structure-soil-structure interaction problems due to earthquakes. In order to produce comparable results of interaction problems as well as for shallow and for deep soils due to the same earthquake excitation (accelerogram) situated always at the lower bedrock boundary, the analysis is performed in two steps: 1) Calculation of the complex transfer function and the response of the upper interior boundary of a layered soil-system which is connected at its top to a soil-structure-system, using the one-dimensional deconvolution. 2) By making a complete interaction analysis of the surface soil-structure-system using the interior boundary excitation of the calculated response from step 1. The depth of the soil-structure-system must be chosen large enough to exclude interaction effects down to the layered soil-system's interior boundary. (orig.)

Structures in sculptures

DEFF Research Database (Denmark)

Vanggaard, Ole

Conceptual design of structures in architecture involves a dialog between a structural and an architectural concept. The architecture is very often changed in this process. The dialog between the parties are described and well known. It is often very difficult to bridge the gab between...... the different concepts and find a final synthesis, but the problem is known. Large sculptures represent structural challenges. The design of the supports inside the structures reveals often a very different world from the outside view of the sculpture. The piece of art and its structure may have two very...... different lives. A sculpture of today may be very dissimilar from what we have seen earlier. The structure becomes sometimes a visual part of the art. Ultimately, there may not be any distinction between structure and art. The technical demand, the durability and the safety are just as important for a large...

Electromagnetic and structural interaction analysis of curved shell structures

International Nuclear Information System (INIS)

Horie, T.; Niho, T.

1993-01-01

This paper describes a finite element formulation of the eddy current and structure coupled problem for curved shell structures. Coupling terms produced by curved geometry as well as flat plate geometry were obtained. Both matrix equations for eddy current and structure were solved simultaneously using coupling sub-matrices. TEAM Workshop bench mark problem 16 was solved to verify the formulation and the computer code. Agreement with experimental results was very good for such plate problem. A coupled problem for cylindrical shell structure was also analyzed. Influence of each coupling term was examined. The next topic is the eigenvalues of the coupled equations. Although the coupled matrix equations are not symmetric, symmetry was obtained by introducing a symmetrizing variable. The eigenvalues of the coupled matrix equations are different from those obtained from the uncoupled equations because of the influence of the coupling sub-matrix components. Some parameters obtained by the eigenvalue analysis have characteristics of parameters which indicate the intensity of electromagnetic structural coupling effect. (author)

Structure of polysaccharide and structural analysis by x-ray

International Nuclear Information System (INIS)

Yuguchi, Yoshiaki

2010-01-01

Polysaccharides occur in plants and the living body in the solid, gel, or liquid. They have a highly structural diversity and possess the potential to be used for development of new materials and energy sources. So it is very important to understand their molecular structure under various conditions. This review introduces the structural characteristics of polysaccharides and the examples of their analysis by the X-ray scattering method. (author)

Combustible structural composites and methods of forming combustible structural composites

Science.gov (United States)

Daniels, Michael A.; Heaps, Ronald J.; Steffler, Eric D.; Swank, W. David

2013-04-02

Combustible structural composites and methods of forming same are disclosed. In an embodiment, a combustible structural composite includes combustible material comprising a fuel metal and a metal oxide. The fuel metal is present in the combustible material at a weight ratio from 1:9 to 1:1 of the fuel metal to the metal oxide. The fuel metal and the metal oxide are capable of exothermically reacting upon application of energy at or above a threshold value to support self-sustaining combustion of the combustible material within the combustible structural composite. Structural-reinforcing fibers are present in the composite at a weight ratio from 1:20 to 10:1 of the structural-reinforcing fibers to the combustible material. Other embodiments and aspects are disclosed.

Study of structural reliability of existing concrete structures

Science.gov (United States)

Druķis, P.; Gaile, L.; Valtere, K.; Pakrastiņš, L.; Goremikins, V.

2017-10-01

Structural reliability of buildings has become an important issue after the collapse of a shopping center in Riga 21.11.2013, caused the death of 54 people. The reliability of a building is the practice of designing, constructing, operating, maintaining and removing buildings in ways that ensure maintained health, ward suffered injuries or death due to use of the building. Evaluation and improvement of existing buildings is becoming more and more important. For a large part of existing buildings, the design life has been reached or will be reached in the near future. The structures of these buildings need to be reassessed in order to find out whether the safety requirements are met. The safety requirements provided by the Eurocodes are a starting point for the assessment of safety. However, it would be uneconomical to require all existing buildings and structures to comply fully with these new codes and corresponding safety levels, therefore the assessment of existing buildings differs with each design situation. This case study describes the simple and practical procedure of determination of minimal reliability index β of existing concrete structures designed by different codes than Eurocodes and allows to reassess the actual reliability level of different structural elements of existing buildings under design load.

Structure-borne sound structural vibrations and sound radiation at audio frequencies

CERN Document Server

Cremer, L; Petersson, Björn AT

2005-01-01

Structure-Borne Sound"" is a thorough introduction to structural vibrations with emphasis on audio frequencies and the associated radiation of sound. The book presents in-depth discussions of fundamental principles and basic problems, in order to enable the reader to understand and solve his own problems. It includes chapters dealing with measurement and generation of vibrations and sound, various types of structural wave motion, structural damping and its effects, impedances and vibration responses of the important types of structures, as well as with attenuation of vibrations, and sound radi

Structural Health Monitoring: Numerical Damage Predictor for Composite Structures

National Research Council Canada - National Science Library

Lannamann, Daniel

2001-01-01

.... Wide use of composites is found in aircraft, armored vehicles, ships and civil structures This present research demonstrates the ability to numerically detect damage in a composite sandwich structure...

Structural stability and electronic structure of YCu ductile ...

African Journals Online (AJOL)

We investigate the structural, elastic and electronic properties of cubic YCu intermetallic compound. Which crystallize in the CsCl- B2 type structure, the investigated using the first principle full potential linearized augmented plane wave method (FP-LAPW) within density functional Theory (DFT). We used generalized ...

Accurate protein structure modeling using sparse NMR data and homologous structure information.

Science.gov (United States)

Thompson, James M; Sgourakis, Nikolaos G; Liu, Gaohua; Rossi, Paolo; Tang, Yuefeng; Mills, Jeffrey L; Szyperski, Thomas; Montelione, Gaetano T; Baker, David

2012-06-19

While information from homologous structures plays a central role in X-ray structure determination by molecular replacement, such information is rarely used in NMR structure determination because it can be incorrect, both locally and globally, when evolutionary relationships are inferred incorrectly or there has been considerable evolutionary structural divergence. Here we describe a method that allows robust modeling of protein structures of up to 225 residues by combining (1)H(N), (13)C, and (15)N backbone and (13)Cβ chemical shift data, distance restraints derived from homologous structures, and a physically realistic all-atom energy function. Accurate models are distinguished from inaccurate models generated using incorrect sequence alignments by requiring that (i) the all-atom energies of models generated using the restraints are lower than models generated in unrestrained calculations and (ii) the low-energy structures converge to within 2.0 Å backbone rmsd over 75% of the protein. Benchmark calculations on known structures and blind targets show that the method can accurately model protein structures, even with very remote homology information, to a backbone rmsd of 1.2-1.9 Å relative to the conventional determined NMR ensembles and of 0.9-1.6 Å relative to X-ray structures for well-defined regions of the protein structures. This approach facilitates the accurate modeling of protein structures using backbone chemical shift data without need for side-chain resonance assignments and extensive analysis of NOESY cross-peak assignments.

Antibody structural modeling with prediction of immunoglobulin structure (PIGS)

DEFF Research Database (Denmark)

Marcatili, Paolo; Olimpieri, Pier Paolo; Chailyan, Anna

2014-01-01

Antibodies (or immunoglobulins) are crucial for defending organisms from pathogens, but they are also key players in many medical, diagnostic and biotechnological applications. The ability to predict their structure and the specific residues involved in antigen recognition has several useful...... applications in all of these areas. Over the years, we have developed or collaborated in developing a strategy that enables researchers to predict the 3D structure of antibodies with a very satisfactory accuracy. The strategy is completely automated and extremely fast, requiring only a few minutes (∼10 min...... on average) to build a structural model of an antibody. It is based on the concept of canonical structures of antibody loops and on our understanding of the way light and heavy chains pack together....

Kinematics, structural mechanics, and design of origami structures with smooth folds

Science.gov (United States)

Peraza Hernandez, Edwin Alexander

Origami provides novel approaches to the fabrication, assembly, and functionality of engineering structures in various fields such as aerospace, robotics, etc. With the increase in complexity of the geometry and materials for origami structures that provide engineering utility, computational models and design methods for such structures have become essential. Currently available models and design methods for origami structures are generally limited to the idealization of the folds as creases of zeroth-order geometric continuity. Such an idealization is not proper for origami structures having non-negligible thickness or maximum curvature at the folds restricted by material limitations. Thus, for general structures, creased folds of merely zeroth-order geometric continuity are not appropriate representations of structural response and a new approach is needed. The first contribution of this dissertation is a model for the kinematics of origami structures having realistic folds of non-zero surface area and exhibiting higher-order geometric continuity, here termed smooth folds. The geometry of the smooth folds and the constraints on their associated kinematic variables are presented. A numerical implementation of the model allowing for kinematic simulation of structures having arbitrary fold patterns is also described. Examples illustrating the capability of the model to capture realistic structural folding response are provided. Subsequently, a method for solving the origami design problem of determining the geometry of a single planar sheet and its pattern of smooth folds that morphs into a given three-dimensional goal shape, discretized as a polygonal mesh, is presented. The design parameterization of the planar sheet and the constraints that allow for a valid pattern of smooth folds and approximation of the goal shape in a known folded configuration are presented. Various testing examples considering goal shapes of diverse geometries are provided. Afterwards, a

Optimal Priority Structure, Capital Structure, and Investment

OpenAIRE

Dirk Hackbarth; David C. Mauer

2012-01-01

We study the interaction between financing and investment decisions in a dynamic model, where the firm has multiple debt issues and equityholders choose the timing of investment. Jointly optimal capital and priority structures can virtually eliminate investment distortions because debt priority serves as a dynamically optimal contract. Examining the relative efficiency of priority rules observed in practice, we develop several predictions about how firms adjust their priority structure in res...

Diverter structure

Energy Technology Data Exchange (ETDEWEB)

Nayama, Risuke; Toyota, Masahiko; Tsujimura, Seiichi

1995-11-21

The present invention concerns a vacuum vessel for a tokamak-type nuclear fusion plasma experimental device, and provides a divertor structure capable of reducing a distance of a plasma facing surface of a divertor structure and an inner wall of the vacuum vessel while maintaining cooling and heat removing performance. Namely, in the divertor structure of the present invention, a compulsory cooling channel on the side receiving high temperature load is made of a highly heat conductive material such as copper. The compulsory cooling channel on the side secured to a substrate is made of a material having high mechanical strength, for example, stainless steel. With such a constitution, the compulsory cooling channel on the side receiving high temperature load transfers the heat received by an armour material from plasmas efficiently to coolants. The opposite side can be secured to the inner wall of the vacuum vessel with satisfactory mechanical strength without interposing other additional materials. As a result, the structure of the present invention can reduce the distance of the plasma facing surface of the divertor structure and the inner wall of the vacuum vessel while maintaining the cooling and heat removing performance. (I.S.).

Diverter structure

International Nuclear Information System (INIS)

Nayama, Risuke; Toyota, Masahiko; Tsujimura, Seiichi.

1995-01-01

The present invention concerns a vacuum vessel for a tokamak-type nuclear fusion plasma experimental device, and provides a divertor structure capable of reducing a distance of a plasma facing surface of a divertor structure and an inner wall of the vacuum vessel while maintaining cooling and heat removing performance. Namely, in the divertor structure of the present invention, a compulsory cooling channel on the side receiving high temperature load is made of a highly heat conductive material such as copper. The compulsory cooling channel on the side secured to a substrate is made of a material having high mechanical strength, for example, stainless steel. With such a constitution, the compulsory cooling channel on the side receiving high temperature load transfers the heat received by an armour material from plasmas efficiently to coolants. The opposite side can be secured to the inner wall of the vacuum vessel with satisfactory mechanical strength without interposing other additional materials. As a result, the structure of the present invention can reduce the distance of the plasma facing surface of the divertor structure and the inner wall of the vacuum vessel while maintaining the cooling and heat removing performance. (I.S.)

Development of the tube bundle structure for fluid-structure interaction analysis model

International Nuclear Information System (INIS)

Yoon, Kyung Ho; Kim, Jae Yong

2010-02-01

Tube bundle structures within a Boiler or heat exchanger are laid the fluid-structure, thermal-structure and fluid-thermal-structure coupled boundary condition. In these complicated boundary conditions, Fluid-structure interaction (FSI) occurs when fluid flow causes deformation of the structure. This deformation, in turn, changes the boundary conditions for the fluid flow. The structural analysis discipline, and then independently analyzed each other. However, the fluid dynamic force effect the behavior of the structure, and the vibration amplitude of the structure to fluid. FSI analysis model was separately created fluid and structure model, and then defined the fsi boundary condition, and simultaneously analyzed in one domain. The analysis results were compared with those of the experimental method for validating the analysis model. Flow-induced vibration test was executed with single rod configuration. The vibration amplitudes of a fuel rod were measured by the laser vibro-meter system in x and y-direction. The analyses results were not closely with the test data, but the trend was very similar with the test result. In fsi coupled analysis case, the turbulent model was very important with the reliability of the accuracy of the analysis model. Therefore, the analysis model will be needed to further study

Hydraulic structures

CERN Document Server

Chen, Sheng-Hong

2015-01-01

This book discusses in detail the planning, design, construction and management of hydraulic structures, covering dams, spillways, tunnels, cut slopes, sluices, water intake and measuring works, ship locks and lifts, as well as fish ways. Particular attention is paid to considerations concerning the environment, hydrology, geology and materials etc. in the planning and design of hydraulic projects. It also considers the type selection, profile configuration, stress/stability calibration and engineering countermeasures, flood releasing arrangements and scouring protection, operation and maintenance etc. for a variety of specific hydraulic structures. The book is primarily intended for engineers, undergraduate and graduate students in the field of civil and hydraulic engineering who are faced with the challenges of extending our understanding of hydraulic structures ranging from traditional to groundbreaking, as well as designing, constructing and managing safe, durable hydraulic structures that are economical ...

Antibody structural modeling with prediction of immunoglobulin structure (PIGS)

KAUST Repository

Marcatili, Paolo

2014-11-06

© 2014 Nature America, Inc. All rights reserved. Antibodies (or immunoglobulins) are crucial for defending organisms from pathogens, but they are also key players in many medical, diagnostic and biotechnological applications. The ability to predict their structure and the specific residues involved in antigen recognition has several useful applications in all of these areas. Over the years, we have developed or collaborated in developing a strategy that enables researchers to predict the 3D structure of antibodies with a very satisfactory accuracy. The strategy is completely automated and extremely fast, requiring only a few minutes (~10 min on average) to build a structural model of an antibody. It is based on the concept of canonical structures of antibody loops and on our understanding of the way light and heavy chains pack together.

The structure of liquid water; La structure de l'eau liquide

Energy Technology Data Exchange (ETDEWEB)

Marin, B [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-07-01

We have tried to expose a bibliography so complete as possible on structure of liquid water. One synthesis of the different models of water structure is presently impossible, so, we have exposed the main properties of water. We have pointed out the new hypotheses on the electronic structure of water molecule and on the theory of hydrogen bond. After that, we have put together the studies of structure by spectroscopy and given the main deductions of some workers on this subject. We have also exposed the characteristics of processes: relaxation and dielectric constant, influence of temperature on structure. At last, we have considered briefly the partition and thermodynamic functions established from the various models proposed. (author) [French] Nous nous sommes proposes d'ecrire une bibliographie aussi complete que possible sur la structure de l'eau liquide. Apres avoir rappele les differentes tentatives d'etablissement de modele de structure, et s'etre rendu compte qu'une synthese s'averait impossible, il nous est apparu souhaitable d'exposer les principales proprietes de l'eau. C'est ainsi que nous avons donne les hypotheses les plus recentes sur la structure electronique de la molecule d'eau ainsi que celles concernant la theorie de la liaison hydrogene. Puis nous avons rassemble les etudes de structure par spectroscopie et fourni les deductions auxquelles les divers auteurs sont arrives. Nous avons egalement expose les caracteristiques des processus tels que: relaxation et constante dielectrique, l'influence de la temperature sur la structure et enfin nous avons donne brievement les fonctions de partition et les grandeurs thermodynamiques etablies a partir des divers modeles proposes. (auteur)

Cell packing structures

KAUST Repository

Pottmann, Helmut

2015-03-03

This paper is an overview of architectural structures which are either composed of polyhedral cells or closely related to them. We introduce the concept of a support structure of such a polyhedral cell packing. It is formed by planar quads and obtained by connecting corresponding vertices in two combinatorially equivalent meshes whose corresponding edges are coplanar and thus determine planar quads. Since corresponding triangle meshes only yield trivial structures, we focus on support structures associated with quad meshes or hex-dominant meshes. For the quadrilateral case, we provide a short survey of recent research which reveals beautiful relations to discrete differential geometry. Those are essential for successfully initializing numerical optimization schemes for the computation of quad-based support structures. Hex-dominant structures may be designed via Voronoi tessellations, power diagrams, sphere packings and various extensions of these concepts. Apart from the obvious application as load-bearing structures, we illustrate here a new application to shading and indirect lighting. On a higher level, our work emphasizes the interplay between geometry, optimization, statics, and manufacturing, with the overall aim of combining form, function and fabrication into novel integrated design tools.

Extended icosahedral structures

CERN Document Server

Jaric, Marko V

1989-01-01

Extended Icosahedral Structures discusses the concepts about crystal structures with extended icosahedral symmetry. This book is organized into six chapters that focus on actual modeling of extended icosahedral crystal structures. This text first presents a tiling approach to the modeling of icosahedral quasiperiodic crystals. It then describes the models for icosahedral alloys based on random connections between icosahedral units, with particular emphasis on diffraction properties. Other chapters examine the glassy structures with only icosahedral orientational order and the extent of tra

Glass-ceramic nuclear waste forms obtained by crystallization of SiO 2-Al 2O 3-CaO-ZrO 2-TiO 2 glasses containing lanthanides (Ce, Nd, Eu, Gd, Yb) and actinides (Th): Study of the crystallization from the surface

Science.gov (United States)

Loiseau, P.; Caurant, D.

2010-07-01

Glass-ceramic materials containing zirconolite (nominally CaZrTi 2O 7) crystals in their bulk can be envisaged as potential waste forms for minor actinides (Np, Am, Cm) and Pu immobilization. In this study such matrices are synthesized by crystallization of SiO 2-Al 2O 3-CaO-ZrO 2-TiO 2 glasses containing lanthanides (Ce, Nd, Eu, Gd, Yb) and actinides (Th) as surrogates. A thin partially crystallized layer containing titanite and anorthite (nominally CaTiSiO 5 and CaAl 2Si 2O 8, respectively) growing from glass surface is also observed. The effect of the nature and concentration of surrogates on the structure, the microstructure and the composition of the crystals formed in the surface layer is presented in this paper. Titanite is the only crystalline phase able to significantly incorporate trivalent lanthanides whereas ThO 2 precipitates in the layer. The crystal growth thermal treatment duration (2-300 h) at high temperature (1050-1200 °C) is shown to strongly affect glass-ceramics microstructure. For the system studied in this paper, it appears that zirconolite is not thermodynamically stable in comparison with titanite growing form glass surface. Nevertheless, for kinetic reasons, such transformation (i.e. zirconolite disappearance to the benefit of titanite) is not expected to occur during interim storage and disposal of the glass-ceramic waste forms because their temperature will never exceed a few hundred degrees.

Synthesis and characterization of arsenic-doped cysteine-capped thoria-based nanoparticles

International Nuclear Information System (INIS)

Pereira, F. J.; Díez, M. T.; Aller, A. J.

2013-01-01

Thoria materials have been largely used in the nuclear industry. Nonetheless, fluorescent thoria-based nanoparticles provide additional properties to be applied in other fields. Thoria-based nanoparticles, with and without arsenic and cysteine, were prepared in 1,2-ethanediol aqueous solutions by a simple precipitation procedure. The synthesized thoria-based nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (ED-XRS), Raman spectroscopy, Fourier transform infrared (FT-IR) spectroscopy and fluorescence microscopy. The presence of arsenic and cysteine, as well as the use of a thermal treatment facilitated fluorescence emission of the thoria-based nanoparticles. Arsenic-doped and cysteine-capped thoria-based nanoparticles prepared in 2.5 M 1,2-ethanediol solutions and treated at 348 K showed small crystallite sizes and strong fluorescence. However, thoria nanoparticles subjected to a thermal treatment at 873 K also produced strong fluorescence with a very narrow size distribution and much smaller crystallite sizes, 5 nm being the average size as shown by XRD and TEM. The XRD data indicated that, even after doping of arsenic in the crystal lattice of ThO 2 , the samples treated at 873 K were phase pure with the fluorite cubic structure. The Raman and FT-IR spectra shown the most characteristics vibrational peaks of cysteine together with other peaks related to the bonds of this molecule to thoria and arsenic when present

X chromosome and suicide.

Science.gov (United States)

Fiori, L M; Zouk, H; Himmelman, C; Turecki, G

2011-02-01

Suicide completion rates are significantly higher in males than females in most societies. Although gender differences in suicide rates have been partially explained by environmental and behavioral factors, it is possible that genetic factors, through differential expression between genders, may also help explain gender moderation of suicide risk. This study investigated X-linked genes in suicide completers using a two-step strategy. We first took advantage of the genetic structure of the French-Canadian population and genotyped 722 unrelated French-Canadian male subjects, of whom 333 were suicide completers and 389 were non-suicide controls, using a panel of 37 microsatellite markers spanning the entire X chromosome. Nine haplotype windows and several individual markers were associated with suicide. Significant results aggregated primarily in two regions, one in the long arm and another in the short arm of chromosome X, limited by markers DXS8051 and DXS8102, and DXS1001 and DXS8106, respectively. The second stage of the study investigated differential brain expression of genes mapping to associated regions in Brodmann areas 8/9, 11, 44 and 46, in an independent sample of suicide completers and controls. Six genes within these regions, Rho GTPase-activating protein 6, adaptor-related protein complex 1 sigma 2 subunit, glycoprotein M6B, ribosomal protein S6 kinase 90  kDa polypeptide 3, spermidine/spermine N(1)-acetyltransferase 1 and THO complex 2, were found to be differentially expressed in suicide completers.

Protein structure recognition: From eigenvector analysis to structural threading method

Science.gov (United States)

Cao, Haibo

In this work, we try to understand the protein folding problem using pair-wise hydrophobic interaction as the dominant interaction for the protein folding process. We found a strong correlation between amino acid sequence and the corresponding native structure of the protein. Some applications of this correlation were discussed in this dissertation include the domain partition and a new structural threading method as well as the performance of this method in the CASP5 competition. In the first part, we give a brief introduction to the protein folding problem. Some essential knowledge and progress from other research groups was discussed. This part include discussions of interactions among amino acids residues, lattice HP model, and the designablity principle. In the second part, we try to establish the correlation between amino acid sequence and the corresponding native structure of the protein. This correlation was observed in our eigenvector study of protein contact matrix. We believe the correlation is universal, thus it can be used in automatic partition of protein structures into folding domains. In the third part, we discuss a threading method based on the correlation between amino acid sequence and ominant eigenvector of the structure contact-matrix. A mathematically straightforward iteration scheme provides a self-consistent optimum global sequence-structure alignment. The computational efficiency of this method makes it possible to search whole protein structure databases for structural homology without relying on sequence similarity. The sensitivity and specificity of this method is discussed, along with a case of blind test prediction. In the appendix, we list the overall performance of this threading method in CASP5 blind test in comparison with other existing approaches.