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Photoluminescence properties and local electronic structures of rare earth (Eu^3^+ and Ce^3^+) activated Sr3AlO4F have been studied. X-ray powder diffraction data indicated that the activator ions of Eu^3^+ and Ce^3^+ can be incorporated into the Sr3AlO4F lattice and formed limited solid solutions of Sr3-2xLnxNaxAlO4F (Ln=Eu, Ce) with Na^+ as a charge compensator ion. The local structure around Sr sites was initially explored using Eu-activated Sr3AlO4F as a structural probe. Sr3AlO4F:Eu^3^+ exhibits orange-red emission ranging from 520 to 740nm with a maximum peak at about 619nm mainly originating from the ^5D0->^7FJ (J=0, 1, 2, 3, 4) transitions, indicating that Eu exists mainly in the trivalent state due to a strong oxidative lattice in ...

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Absorption and emission measurements at liquid-helium temperature, liquid-nitrogen temperature and room temperature have been performed on tetragonal scheelite-type rare earth sodium double molybdates Na[sub 5]RE(MoO[sub 4])[sub 4] and on RE-doped Na[sub 5]Gd(MoO[sub 4])[sub 4] samples. The rare earth occupies one single crystallographic position with S[sub 4] as point symmetry. The spectra were analysed according to the crystal field theory. From the experimental data, nearly complete energy level schemes of the Pr[sup 3+] and Nd[sup 3+], on the 4f [sup 2] and 4f [sup 3] configurations were derived. Very good correlation was obtained between the experimental and simulated energy level schemes, first for the approximated D[sub 2d] and then for the true S[sub 4] symmetries. The crystal field parameters vary smoothly with the atomic number of the rare ...

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We have constructed a Monte Carlo generator (the corresponding FORTRAN code can be obtained from the authors upon request) for lowest-order predictions for the processes {gamma}{gamma}{yields}4f and {gamma}{gamma}{yields}4f{gamma} in the standard model and extensions thereof by an effective {gamma}{gamma}H coupling as well as anomalous triple and quartic gauge-boson couplings. Polarization is fully supported, and a realistic photon beam spectrum can be taken into account. For the processes {gamma}{gamma}{yields}4f all helicity amplitudes are explicitly given in a compact form. The presented numerical results contain, in particular, a survey of cross sections for representative final states and their comparison to results obtained with the program package Whizard/Madgraph. The impact of a realistic ...

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The optical absorption spectra of the rhombohedral DyOF were measured at selected temperatures between 9 and 300 K. The emission spectra of the Dy{sup 3+} ion in the LaOF and GdOF matrices were obtained at 77 K and room temperature. The energy level scheme of Dy{sup 3+} (4f{sup 9} electron configuration) was simulated with a Hamiltonian of 20 parameters. The diagonalization of the energy matrices including simultaneously the free ion and crystal field (c.f.) interactions was carried out for the C{sub 3{upsilon}} point symmetry of the RE{sup 3+} site. Good correlation with an rms deviation of 17 cm{sup -1} was obtained between the experimental and calculated energy level schemes of 153 Kramers doublets. The c.f. parameters show only slight distortion from O{sub h} symmetry. A comparison to Pr{sup 3+} (4f{sup 2}), Nd{sup 3+} (4f{sup 3}), Sm{sup 3+} ...

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the Samsung K4F660812 DRAM were measured by the JPL Radiation Effects. Group [1] . ... The Samsung K4F660812 is a 8 x 223 bit Fast Page CMOS DRAM. The two- ...

International Nuclear Information System (INIS)

The crystal structure of borophosphates ABPO_5 (A = alkaline earth or Pb) was resolved on a polycrystalline sample using the Rietveld method. The x-ray diffraction patterns data show that ABPO_5 crystallize in a centrosymmetric space group P3_121 and their structure is related to the borogermanates REBGeO_5 with a stillwellite-type structure. Pr"3"+ ion was used as a local structural probe to corroborate the structural resolution results. Absorption and fluorescence spectra of A_1_-_xPr_xBP_1_-_xGe_xO_5 (A alkaline earth or Pb; x = 0.05) have been investigated at different temperatures. At 9 K the 3"H_4#->#"3P_0 transition of trivalent praseodymium ion (4f"2 configuration) is observed as a single line. This indicates a unique crystallographic site for the rare earth ion in these compounds replacing the divalent cation. Energy level schemes were deduced from the low-temperature ...

British Library Electronic Table of Contents (United Kingdom)

Direct visualization of rare earths in @a- and @b-SiAlON unit-cells is performed through Z-contrast imaging technique in an aberration-corrected scanning transmission electron microscope. The preferential occupation of Yb and Ce atoms in different interstitial locations of @b-SiAlON lattice is demonstrated, yielding higher solubility for Yb than Ce. The triangular-like host sites in @a-SiAlON unit cell accommodate more Ce atoms than hexagonal sites in @b-SiAlON. We think that our results will be applicable as guidelines for many kinds of rare-earth-doped materials.

International Nuclear Information System (INIS)

In YbPd_2Si_2, the valence of Yb is very close to 3+. Ge substitution of Si induces a negative pressure effect and the valence of Yb decreases. For the low Ge concentrations studied, the spin fluctuation temperature T_s_f increases and #chi#4f, the Yb derived 4f susceptibility, obeys the scaling law #chi#4f(T)=F(T/T_s_f). (orig.).

International Nuclear Information System (INIS)

The high resolution absorption, luminescence and excitation spectra of the orthorhombic potassium lanthanum praseodymium ternary chloride, K_2La_1_-_xPr_xCl_5, (0.02 #<=# x #<=# 0.15) single crystals were recorded at 4, 77 and 293 K with different excitation sources. The experimental 4f"2 energy level scheme of the Pr"3"+ ion in K_2LaCl_5 derived from the absorption and emission spectra consisted of 86 (out of 91) Stark components. This energy level scheme was simulated by using a phenomenological crystal field (cf) model which included eight free ion and nine cf parameters according to the C_2_v symmetry. Despite the approximate C_2_v point symmetry instead of the real C_s one, the simulation yielded a very satisfactory rms deviation of 17 cm"-"1 between the experimental and calculated energy level schemes. The results, especially the weak cf strength, are discussed taking into account the bonding characteristics in ...

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Four general topics are covered in respect to the natural space radiation environment: (1) particles trapped by the earth`s magnetic field, (2) cosmic rays, (3) radiation environment inside a spacecraft, (4) laboratory radiation sources. The interaction of radiation with materials is described by ionization effects and displacement effects. Total-dose effects on MOS devices is discussed with respect to: measurement techniques, electron-hole yield, hole transport, oxide traps, interface traps, border traps, device properties, case studies and special concerns for commercial devices. Other device types considered for total-dose effects are SOI devices and nitrided oxide devices. Lastly, single event phenomena are discussed with respect to charge collection mechanisms and hard errors. (GHH)

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Laser excited luminescence and site selective excitation spectra of trivalent terbium (Tb{sup 3+}) in two rare earth oxyfluoride (ROF) matrices, LaOF and GdOF, were detected at temperatures down to liquid helium. From the analyses of spectra, the crystal field (c.f.) fine structure of the {sup 7}F{sub J} (J=0-6) ground multiplet was obtained for the 4f{sup 8} electron configuration. The energy level schemes comprising 26 c.f. sublevels out of 33 allowed for the C{sub 3v} point symmetry of the R{sup 3+} site were simulated according to a phenomenological model taking into account only the c.f. effect. The simulation including six c.f. parameters (B{sub 0}{sup 2}, B{sub 0}{sup 4}, B{sub 3}{sup 4}, B{sub 0}{sup 6}, B{sub 3}{sup 6}, and B{sub 6}{sup 6}) reproduced the experimental energy level schemes in a satisfactory manner with rms deviations of 5 and 6 cm{sup -1} for the LaOF and GdOF hosts, respectively. The c.f. parameter ...

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The photoluminescence spectra of the lanthanum and gadolinium oxynitrates doped with Eu[sup 3+], REONO[sub 3]:Eu[sup 3+] (RE=La and Gd) were measured at 77 and 300 K. The [sup 7]F[sub J] (J=0-5) energy level schemes for the 4f [sup 6] electron configuration were simulated by a C[sub 2v] phenomenological crystal field (CF). The nine non-zero CF parameters for the C[sub 2v] site symmetry reproduce the experimental energy level schemes with rms deviations of 7 and 5 cm[sup -1] for the LaONO[sub 3] and GdONO[sub 3] hosts, respectively. The CF effect is stronger in the lanthanum host although otherwise the CF parameters for the two oxynitrate hosts differ only slightly. The B[sup k][sub 2] (k=2, 4 and 6) values are low indicating only a slight deviation from a higher C[sub 4v] symmetry. The B[sup 2][sub 0], B[sup 4][sub 0] and B[sup 4][sub 4] parameters assume high values which are similar to those obtained previously for the other RE oxy compounds, ...

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f4 f5 f1 f2. (a) Overall process decompress ...... involved the shortest learning curve, was available on several platforms, and was ...

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The UV-vis-NIR absorption spectra of DyOCl were measured at selected temperatures between 9 and 300 K. The emission spectra of Dy{sup 3+} in LaOCl and GdOCl were obtained at 77 K and room temperature. The energy level scheme of Dy{sup 3+} was simulated with the aid of a phenomenological theory of simultaneously taking into account both the free ion and crystal field (c.f.) effects. The model included 14 adjustable parameters describing the electrostatic and the configuration interaction as well as the spin-orbit coupling. The c.f. effect was accounted for by the five non-zero B{sup k}{sub q} parameters according to the C{sub 4v} point symmetry of Dy{sup 3+}. Good simulation of the experimental energy level scheme was achieved with a r.m.s. deviation of 21 cm{sup -1} between the experimental and calculated energy level schemes of 179 Kramers doublets. A comparison to Pr{sup 3+}(4f{sup 2}), Nd{sup 3+} ...

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Automated Transport. Not Studied in Detail. Earth's Neighborhood. Simplified Infrastructure. Mars. Earth-. Moon L. 1. Gateway. Moon. Earth-Sun L. 2. Science ...

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Results on the oxidative dehydrogenation of ethane on rare-earth oxide (REO) based catalysts (Na-P-Sm-O, Sm-Sr(Ca)-O, La-Sr-O and Nd-Sr-O) are described. Oxygen adsorption was found to be a key factor which determines the activity of this type of catalysts. Continuous flow experiments in the presence of catalysts which reveal strong oxygen adsorption showed that the reaction mixture is ignited resulting in an enhanced heat generation at the reactor inlet. The heat produced by the oxidative reactions was sufficient under the conditions chosen for the endothermic thermal pyrolysis which takes place preferentially in the gas phase. Ignition of the reaction mixture is an important catalyst function. Contrary to non-catalytic oxidative dehydrogenation, reaction temperatures above 700 C could be achieved without significant external heat input. Ethylene yields of up to 34-45% (S=66-73%) were obtained on REO-based catalysts under non-isothermal ...

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The X-ray diffraction (XRD) and environmental scanning electron microscopy (ESEM) analyses of plasters collected from the courtyard walls of Djehuty's tomb show anhydrite, calcite, dolomite, quartz, alkali feldspars and accessorial amounts of halite and illite. The external outer bed is mainly composed by anhydrite, since the original hydrous phases of gypsum plaster were desiccated during thirty centuries in the dry land environment of the Luxor area, under low relative humidity and high temperatures. The luminescence analyses by thermoluminescence (TL) and cathodoluminescence (CL) demonstrate as one plaster sample (m8), i.e., 95% anhydrite, displays a gigantic TL emission of 33 555 a.u. and a SEM/CL emission of 2319 a.u. maxima peak. The spectra CL also exhibits a 484 nm peak attributable to the classic {sup 4}F{sub 9/2}{yields}{sup 6}H{sub 15/2} transition circa 490 nm of Dy{sup 3+} and a 573 nm emission of ...

International Nuclear Information System (INIS)

Host matrices for actinide immobilisation will undergo the formation of large helium quantities due to alpha decay. Helium diffusion rate has to be known in order to predict the long-term behaviour of the material, and particularly, the influence of helium accumulation on mechanical properties. A nuclear reaction analysis method, namely the "3He(d, p)"4He reaction, has been used to analyse the evolution of "3He profiles after ion implantations at 1 and 3 MeV in two materials, monoclinic ZrO_2 (as a test material) and Ca_9Nd(PO_4)_5(SiO_4)F_1_._5(OH)_0_._5 britholite (envisaged for Am and Pu long-term storage). Two data processing methods are used: the classical excitation curve (proton yields versus deuteron energy) and second, the proton energy spectrum for a given deuteron energy. The characteristics of the "3He profiles (depth, width) obtained by both methods are compared to SRIM estimations. Their evolution during ...

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M-shell X-ray production cross sections for the light rare-earth elements of {sup 68}Er, {sup 7}Yb and {sup 71}Lu have been measured for incident {sup 4}He{sup +} ions in the energy range from 0.75 to 6 MeV. The measured X-ray production cross sections are compared to the predictions of the First Born approximation, the ECPSSR theory and the ECUSAR theory. A comparison of the ytterbium M-shell X-ray production cross sections with these theories is made for two different sets of fluorescence yields and Coster-Kronig factors that are further modified for multiple ionization.

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For several decades most of the efforts to develop new scintillator materials have concentrated on high-light-yield inorganic single-crystals while polycrystalline ceramic scintillators, since their inception in the early 1980 s, have received relatively little attention. Nevertheless, transparent ceramics offer a promising approach to the fabrication of relatively inexpensive scintillators via a simple mechanical compaction and annealing process that eliminates single-crystal growth. Until recently, commonly accepted concepts restricted the polycrystalline ceramic approach to materials exhibiting a cubic crystal structure. Here, we report our results on the development of two novel ceramic scintillators based on the non-cubic crystalline materials: Lu SiO:Ce (LSO:Ce) and LaBr:Ce. While no evidence for texturing has been found in their ceramic microstructures, our LSO:Ce ceramics exhibit a surprisingly high level of transparency/ translucency and very good ...

International Nuclear Information System (INIS)

Knighton et al. used a pulsed high pressure mass spectrometer to examine thermal electron detachment from C_6F_6"-. This technique had been used earlier for the measurement or detachment rate coefficients for azulene anions as a function of temperature. C_6F_6"- and c-C_4F_6"- have been studied by Datskos et al. using a pulsed drift tube. In our laboratory, we have used a flowing afterglow Langmuir probe (FALP) apparatus to measure the thermal electron detachment rate coefficient for c-C_4F_8"- ions at 375 K. We have also measured the electron attachment rate coefficient for c-C_4F_8 at 303 K and 375 K. (author).

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Our goal was a process to convert methane to higher hydrocarbons oxidatively, since this circumvents thermodynamic yield limits of a strictly degydrogenative process. Keller and Bhasin converted thermodynamic yield limits of a strictly dehydrogenative process. Keller and Bhasin converted methane to higher hydrocarbons by using metal oxides as oxidants, without co-fed oxygen. They stated that selectivity is necessarily poor if gaseous oxygen is present. Jones and Sofranko have also used reducible metal oxides as oxidants in a group of their parents, but later used some of those materials with continuous O{sub 2} feed without much loss of selectivity. Baerns, Lunsford and Otsuka have shown that high selectivity could be possible with co-fed O{sub 2} at least for low O{sub 2} partial pressures, over PbO-A1{sub 2}O{sub 3}, Li-MgO and rare earths. The performance of a group of multicomponent oxide catalysts, containing lead and ...

International Nuclear Information System (INIS)

We report the results of neutron-diffraction experiments on CeM_2Si_2 (M = Ag,Au,Pd,Rh) which were performed to explore the role of valence fluctuations and 4f hybridization in the magnetic ordering of cerium compounds. All four order antiferromagnetically, the first three exhibiting structures consisting of ferromagnetic layers with moments perpendicular to the layers, which are believed to be characteristic of 4f-4f interactions mediated through hybridization with conduction electrons. CePd_2Si_2 has an anomalously small moment (0.62#mu#/sub B/) in the ordered state. CeAg_2Si_2 exhibits an incommensurate longitudinal, static magnetization wave with moment and propagation direction along the a axis. The fourth compound, CeRh_2Si_2, has the highest known transition temperature (39 K) reported for cerium ordering; it exhibits another second-order transition at 27 ...

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Thick targets of several heavy lanthanide (Ho-Lu) compounds were bombarded by protons and /sup 3/He ions of 3 MeV/amu, and M/sub ..cap alpha../ and M/sub ..beta../ X-rays were measured with a crystal spectrometer. Ionization probabilities of the N-shell for zero impact parameter were obtained from the X-ray intensity ratio for proton and /sup 3/He ion impacts. A shell dependence of the ionization probability was found in a scaling plot. X-ray spectra of lanthanide compounds were compared and no chemical effect was observed. This result is considered to be due to the fact that the main component of M/sub ..cap alpha../ and M/sub ..beta../ lines is for radiative transition after the refilling of the 4f orbit (3d/sup -1/4f/sup n+1/ -> 4f/sup n/) where n denotes the number of 4f electrons of the target atom before ...

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Eu 4f electronic structures of a temperature-induced valence transition system EuPd{sub 2}Si{sub 2} have been investigated by bulk-sensitive high-resolution photoemission spectroscopy at temperatures from 20 to 300 K. The bulk Eu{sup 2+} 4f component is definitely distinguished from two surface Eu{sup 2+} 4f components. The changes in the spectral intensity of the bulk Eu{sup 2+} and Eu{sup 3+} 4f configurations and in the energy separation between these states are observed in the temperature dependent photoemission spectra. These temperature dependences are related to the valence transition of EuPd{sub 2}Si{sub 2}. The Eu mean valence is evaluated to be 2.75{+-}0.03 at 20 K and 2.30{+-}0.05 at 300 K. These values are in good agreement with those evaluated from Moessbauer and Eu L{sub III}-edge X-ray absorption ...

Science.gov (United States)

Tb3+-activated Sr3AlO4F phosphors were synthesized by a high-temperature solid-state reaction method. The investigation of photoluminescence and cathodoluminescence indicates that these phosphors can be effectively excited by ultraviolet light and low-voltage electron beam. The phosphors exhibit a tunable-green emission. The luminescence behaviors are explained by the site occupancy of Tb3+ ions in the host crystal and the cross-relaxation of 5D3 to 5D4 state.

International Nuclear Information System (INIS)

The experimental results of the components substitution effect on crystal structure, electronic transport properties, and Eu effective valence in solid solutions based on EuCu_2Si_2 and EuPd_2Si_2 ternary compounds are presented. It is shown, that when the Eu effective valence reaches the critical value #nu#"c"r_e_f_f=2.1, corresponding to degeneration of the 4f"7 and 4f"6 configurations, the condition of the concentrated Kondo system and an essential perturbation of the band electron spectrum near the Fermi level occur. (orig.).

International Nuclear Information System (INIS)

The crystal structure, electronic structure, and photoluminescence properties of EuxSi6-zAlz-xOz+xN8-z-x (x=0-0.1, 0xMySi6-zAlz-x-yOz+x+yN8-z-x-y (M=2Li, Mg, Ca, Sr, Ba) have been studied. Single-phase EuxSi6-zAlz-xOz+xN8-z-x can be obtained in very narrow ranges of x?0.06 (z=0.15) and z2+ ions can be incorporated into nitrogen-rich Si6-zAlzOzN8-z. The Eu2+ ion is found to occupy the 2b site in a hexagonal unit cell (P63/m) and directly connected by six adjacent nitrogen/oxygen atoms ranging 2.4850-2.5089 A. The calculated host band gaps by the relativistic DV-X? method are about 5.55 and 5.45 eV (without Eu2+ 4f5d levels) for x=0 and 0.013 in EuxSi6-zAlz-xOz+xN8-z-x (z=0.15), in which the top of the 5d orbitals overlap with the Si-3s3p and N-2p orbitals within the bottom of the conduction band of the host. EuxSi6-zAlz-xOz+xN8-z-x shows a strong green emission with a broad Eu2+ band centered at about 530 nm under UV to near-UV excitation range. ...

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Jun 8, 2006 ... It also reflects the large amount of deforestation that has occurred on the Haitian side of the border. One can easily see from satellite imagery ...

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Mar 30, 2007 ... Tropical forests are home to half the Earth's species, and their trees are an immense standing reservoir of carbon. Deforestation will have ...

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Jul 26, 2011 ... The Gateway to Astronaut Photography of Earth hosts the best and most complete online collection of astronaut photographs of the Earth.

Energy Technology Data Exchange (ETDEWEB)

A process is described for the selective oxidation of ammonia to nitric oxide in about 90% or greater yield with a minimum of nitrogen or dinitrogen oxide (N/sub 2/O) as by-products, comprising: (1) contacting gaseous ammonia in an oxygen containing gas optionally with an inert gaseous diluent with a mixed metal perovskite catalyst of the general formula: ABO/sub 3/, wherein: A is selected from the alkali, alkaline earth, lanthanide, or actinide metals or a mixture of these metals having a relatively large ionic, radius, and B is selected from an element or a combination of elements selected from Groups IB, IVB, VB, VIB, VIIB, or VIII of the Periodic Table, wherein the perovskite phase of the catalyst has an equilibrium partial pressure of oxygen at 1000/sup 0/C of greater than about 10/sup -15/ bar; and (2) heating the reactants of step (1) at greater than about 500/sup 0/C under conditions of 10 to 100,000 hr/sup -1/ hourly space velocity.

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There is an increasing interest in using radioisotopes of rare earth elements for internal radiotherapy and for imaging in nuclear medicine. {sup 177}Lu is one of the promising radionuclides. This article reports on the first measurements of the excitation function for the production of {sup 177}Lu with proton-beam energies up to 17 MeV on natural hafnium targets. The experimental cross sections for the reaction {sup nat}Hf(p,x){sup 177}Lu were obtained by the activation of a stacked-foil target and subsequent gamma spectrometry. Theoretical cross sections were calculated up to 35 MeV with the EMPIRE nuclear reaction model code. The measured and calculated cross sections were used for deriving the thick-target yields and for estimating the production of other nuclides than {sup 177}Lu. Measured production cross sections of {sup 175,176,177,178}Ta on the same target are also presented.

International Nuclear Information System (INIS)

In order to effectively recover uranium, rotation speed of solid cathode was examined, and effect of uranium concentration and current density on electrodeposition were confirmed. And the potentiostatic and galvanostatic electrorefining experiments were conducted. Element used in the experiments were Zr, Nd, La chlorides. The reduction potentials of chlorides metals on liquid Cd cathode were measured by cyclic voltammetry experiments. The electrowinning experiments were performed in order to recover small amounts of uranium in salt. Experimental set-up for the batch type reductive extraction experiments were developed and installed. On the base of experimental results of batch type, multi-stage extraction equipment was set-up, and optimum number of stage and recover yield were measured. In the oxidative extraction study is examine selective separation behavior of the rare earth metals from alloy composed of actinide and lanthanide metals to ...

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Electrochemical performance and structural properties of the high-voltage cathode material Li{sub 2}CoPO{sub 4}F have been investigated. The cyclic voltammetry and coulometry under potential step mode in the voltage range 3.0-5.1 V vs. Li revealed a structural transformation at potentials above 4.8 V. This transformation occurring upon Li-extraction appears to be irreversible: the subsequent Li-insertion does not result in restoration of the initial structure, but takes place within a new ''modified'' framework. According to the structure refinement this modification involves the mutual rotations of (CoO{sub 4}F{sub 2}) octahedra and (PO{sub 4}) tetrahedra accompanied by the considerable unit cell expansion which is expected to enhance the Li-transport upon subsequent cycling. The new framework demonstrates a reversible Li-insertion/extraction in a solid-solution ...

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The optical absorption of the Tm{sup 3+} ion in the gadolinium oxychloride (GdOCl) matrix in the UV, visible, and NIR range was studied at temperatures between 9 and 300 K. The visible luminescence of GdOCl:Tm{sup 3+} under Ar{sup +} ion laser and mercury lamp excitation was recorded at 9, 77, and 300 K, too. The crystal field (CF) splitting of the {sup 3}H{sub 4-6}, {sup 3}F{sub 2-4}, {sup 1}G{sub 4}, {sup 1}D{sub 2}, and {sup 1}I{sub 6} levels of the Tm{sup 3+} ion deduced from the spectra was analysed according to the C{sub 4v} point symmetry of the RE{sup 3+} site. The resulting energy level scheme, consisting of 39 levels (i.e. 55 Stark components) out of the total of 70 (91) for the whole 4f{sup 12} configuration, was simulated with the aid of a phenomenological theory taking simultaneously into account both the free-ion and CF effects. The model included 13 adjustable parameters describing the electrostatic (the Racah parameters E{sub ...

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As a new high-voltage cathode candidate for post 4V cathodes, ordered-olivine LiCoPO{sub 4} and fluoride phosphate, Li{sub 2}CoPO{sub 4}F were synthesized by solid-state reaction. Their structures were identified by neutron diffraction. The 5V discharge profiles were demonstrated using coin-type cells. Two important issues for commercial use, metal dissolution and oxygen release at elevated temperatures, were also tested with an atomic absorption spectrophotometer and differential scanning calorimeter, respectively. (author)

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Description of how global warming could be disastrous for much of the earth's population....

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...global warming situation is more than evaporation around ...background red ? which was the global warming the ...

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27 cases including 7 outpatients, underwent intraarterial DSA using 4-F nylon catheter, by transbrachial arterial approach. Much of DSAs were performed in Fuji Computed Radiography (FCR), which has high spatial resolution. In all cases, image quality satisfied clinical demands. No major complication occured in this series. Transbrachial arterial digital subtraction angiography is excellent and safe method for screening of vascular disease. (author).

International Nuclear Information System (INIS)

We have constructed a Monte Carlo generator (the corresponding FORTRAN code can be obtained from the authors upon request) for lowest-order predictions for the processes #gamma##gamma##->#4f and #gamma##gamma##->#4f#gamma# in the standard model and extensions thereof by an effective #gamma##gamma#H coupling as well as anomalous triple and quartic gauge-boson couplings. Polarization is fully supported, and a realistic photon beam spectrum can be taken into account. For the processes #gamma##gamma##->#4f all helicity amplitudes are explicitly given in a compact form. The presented numerical results contain, in particular, a survey of cross sections for representative final states and their comparison to results obtained with the program package Whizard/Madgraph. The impact of a realistic beam spectrum on cross sections and distributions is illustrated. ...

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Al Fleig, PITA Analytic Sciences. 7th Earth Science Data Systems Working Group Meeting ..... The Reuse Industry in Brazil, CESAR, and the Reuse in Software ...

British Library Electronic Table of Contents (United Kingdom)

The estimation of numerical values of the mean distance of closest approach of ions, a, of alkaline-earth metal ion salts in aqueous solutions, determined from activity coefficients, as well as from different theoretical approaches, is presented and discussed.

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This frequently-asked-questions feature provides answers about earthquakes, faults, plate tectonics, and earth structure. Maps and diagrams are provided with some answers, and links to additional information and to related topics are included.

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We calculate the expected fluxes of cosmic ray nuclei with charge 5 ≤ Z ≤ 28 at various depths in the earth's atmosphere, taking into account the initial charge distribution,...Full Text Available

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... angular momentum cranking model even-even nuclei gadolinium 156 governor

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This paper presents an analysis of the performance of a selective emitter using small particles of rare earth compounds stable at high temperatures in a low emittance inert gas stream. An expression for the spectral emissive power excluding radiation scattering was derived to include the radiation in the emission band, produced by electronic transitions of the rare earth ion, and the continuum radiation outside the emission band produced by the rare earth host. Preliminary results suggest that a selective emitter based on suspended rare earth oxide particles will have high efficiency and merits further experimental investigation. {copyright} {ital 1996 American Institute of Physics.}

International Nuclear Information System (INIS)

The rare earth antimonates RE_3Sb_5O_1_2 constitute an isostructural series, where the rare earth site symmetry is S_4. The spectroscopic properties of pure or doped compounds of this family are studied in order to derive their energy level schemes and to simulate them through the crystal field theory, by using the approximated D_2_d potential. The paramagnetic susceptibilities are calculated with the derived wavefunctions and compared to experiment.

CERN Document Server

We calculated the matter effect, including both the Earth and supernova, on the detection of neutrinos from type II supernovae at the proposed Daya Bay reactor neutrino experiment. It is found that apart from the dependence on the flip probability P_H inside the supernova and the mass hierarchy of neutrinos, the amount of the Earth matter effect depends on the direction of the incoming supernova neutrinos, and reaches the biggest value when the incident angle of neutrinos is around 93^\\circ. In the reaction channel \\bar{\

International Nuclear Information System (INIS)

The O(#alpha#) electroweak radiative corrections to #gamma##gamma##->#WW#->#4f within the electroweak standard model are calculated in double-pole approximation (DPA). Virtual corrections are treated in DPA, leading to a classification into factorizable and non-factorizable contributions, and real-photonic corrections are based on complete lowest-order matrix elements for #gamma##gamma##->#4f+#gamma#. Soft and collinear singularities appearing in the virtual and real corrections are combined alternatively in two different ways, namely by using the dipole subtraction method or by applying phase-space slicing. The radiative corrections are implemented in a Monte Carlo generator called Coffer #gamma##gamma# - the computer code can be obtained from the authors upon request - which optionally includes anomalous triple and quartic gauge-boson couplings in addition and performs a convolution over ...

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A phenomenological simulation was carried out for 41 experimental crystal-field (CF) levels within the {sup 4}I{sub 9/2-15/2}, {sup 4}F{sub 3/2-9/2}, {sup 4}S{sub 3/2} and {sup 2}H{sub 9/2} J manifolds, including the available infrared (IR) data up to {approx}15 000 cm{sup -1} for the Nd{sup 3+} ions in the Nd{sub 2}CuO{sub 4} single crystals. The CF Hamiltonian for the tetragonal C{sub 4v} symmetry was diagonalized together with the free-ion Hamiltonian in a basis that spans the entire 4f{sup 3} configuration. A rms error of 9 cm{sup -1} between the calculated and experimental energy level schemes was obtained. A comparison of the spectra in the visible region between the insulating Nd{sub 2}CuO{sub 4} and the metallic Nd{sub 2-x}Ce{sub x}CuO{sub 4}, allowed identifying the absorption bands associated with the development of the charge-doping induced local structural distortions in the superconducting ...

British Library Electronic Table of Contents (United Kingdom)

For the reuse of a waste salt from an electrorefining process of a spent oxide fuel, a separation of rare earth elements by an oxidative precipitation in a LiCl-KCl molten salt was tested without using precipitate agents. From the results obtained from the thermochemical calculations by HSC Chemistry software, the most stable rare earth compounds in the oxygen-used rare earth chlorides system were oxychlorides (EuOCl, NdOCl, PrOCl) and oxides (CeO2, PrO2), which coincide well with results of the Gibbs free energy of the reaction. In this study, similar to the thermochemical results, regardless of the sparging time and molten salt temperature, oxychlorides and oxides were formed as a precipitant by a reaction with oxygen. The structure of the rare earth precipitates was divided into two sha...

CERN Document Server

The possible physical linkage between galactic cosmic rays intensity and the Earth's cloud cover is discussed using the analysis of the first indirect aerosol effect (Twomey effect) and its experimental representation as the dependence of average cloud droplet effective radius on aerosol index characterizing the aerosol concentration in the atmospheric air column of unit section. It is shown that the basic kinetic equation of the Earth's climate energy-balance model is described by the bifurcation equation (with respect to the temperature of the Earth's surface) in the form of fold catastrophe with two governing parameters defining the variations of insolation and Earth's magnetic field (or galactic cosmic rays intensity in the atmosphere), respectively. The principle of hierarchical climatic models construction, which consists in the structural invariance of balance equations of these models evolving ...

International Nuclear Information System (INIS)

The magnetic susceptibility of the ternary compounds, RPd_2Si_2 (where R=Gd, Tb, Dy, Ho and Er) has been measured. GdPd_2Si_2 and TbPd_2Si_2 order antiferromagnetically at 13 and 20 K respectively; the rest of the compounds do not show clear ordering down to 4.2 K. Palladium carries no moment in these compounds. The De Gennes formula is not obeyed indicating that the exchange interaction between the 4f moments via conduction electrons is not isotropic. (orig.).

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

For the reuse of a waste salt from an electrorefining process of a spent oxide fuel, a separation of rare earth elements by an oxidative precipitation in a LiCl-KCl molten salt was tested without using precipitate agents. From the results obtained from the thermochemical calculations by HSC Chemistry software, the most stable rare earth compounds in the oxygen-used rare earth chlorides system were oxychlorides (EuOCl, NdOCl, PrOCl) and oxides (CeO2, PrO2), which coincide well with results of the Gibbs free energy of the reaction. In this study, similar to the thermochemical results, regardless of the sparging time and molten salt temperature, oxychlorides and oxides were formed as a precipitant by a reaction with oxygen. The structure of the rare earth precipitates was divided into two shapes: small cubic (oxide) and large plate-like (tetragonal) structures. The conversion efficiencies of the rare ...

International Nuclear Information System (INIS)

Uranium dendrites which were deposited at a solid cathode of an electrorefiner contained a certain amount of salts. These salts should be removed for the recovery of pure metal using a cathode processor. In the uranium deposits from the electrorefining process, there are actinide chlorides and rare earth chlorides in addition to uranium chloride in the LiCl-KCl eutectic salt. The evaporation behaviors of the actinides and rare earth chlorides in the salts should be investigated for the removal of salts in the deposits. Experiments on the salt evaporation of rare earth chlorides in a LiCl-KCl eutectic salt were carried out. Though the vapor pressures of the rare earth chlorides were lower than those of the LiCl and KCl, the rare earth chlorides were co-evaporized with the LiCl-KCl eutectic salt. The Hertz-Langmuir relation was applied for this evaporation, and also the evaporation ...

Science.gov (United States)

Mesporous anatase-phase TiO(2) hollow spheres with high photocatalytic activity were prepared by hydrothermal treatment and self-transformation of amorphous TiO(2) solid spheres in an NH(4)F aqueous solution. The prepared samples were characterized by X-ray diffraction, scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, N(2) adsorption-desorption isotherms and UV-vis absorption spectroscopy. The photocatalytic activity was evaluated by photocatalytic oxidation decomposition of acetone in air under UV irradiation. It is found that F(-) plays an essential role in the formation of TiO(2) hollow spheres. F(-) not only induces the hollowing of TiO(2) solid spheres, but also promotes the crystallization of anatase TiO(2) nanocrystals. A possible formation mechanism for the TiO(2) hollow spheres by localized Ostwald ripening or chemically induced self-transformation is proposed based on the experimental observations. ...

Energy Technology Data Exchange (ETDEWEB)

The rare earth antimonates RE{sub 3}Sb{sub 5}O{sub 12} constitute an isostructural series, where the rare earth site symmetry is S{sub 4}. The spectroscopic properties of pure or doped compounds of this family are studied in order to derive their energy level schemes and to simulate them through the crystal field theory, by using the approximated D{sub 2d} potential. The paramagnetic susceptibilities are calculated with the derived wavefunctions and compared to experiment.

British Library Electronic Table of Contents (United Kingdom)

Abstract The creation of chirality on Earth and the development of chiral life have been discussed in this highlight. Convincing evidence for the introduction of chirality on Earth is still fragmentary. We believe that by a combination of chiral crystallization and formation of helical polymers with preferred chiral conformational structure is the key to this question. This concept of macromolecular asymmetry has inspired ideas and resulted in possible rules for how chiral life as we know it, could have been introduced. These investigations needed the understanding of the requirements for chiral crystallization, for the stereochemistry of the initial formation of helical polymers, the measurements of optical activity of solids and their coordination with the fundamentals of chirality. Spac...

British Library Electronic Table of Contents (United Kingdom)

The gravitational torque applied on the Earth by the other celestial bodies generates periodic variations in the orientation of the Earth's rotation axis in space which are called nutations. Observations of Earth's nutations allow for insights into the physical properties of the inner core because of the presence of a normal mode, the Free Inner Core Nutation (FICN), which is characterized by a tilt of the inner core figure and rotation axes with respect to the mantle and outer core. The frequency of the FICN is controlled by the strength of the mechanical coupling acting at the inner core boundary (ICB) and by the ability of the inner core to deform under the action of centrifugal and gravitational forces. Attenuation of the FICN reflects energy dissipated by electromagnetic (EM) and visc...

Science.gov (United States)

Nov 8, 2010 ... Ihring Mission 11, the radiation dosimetry measurement system functioned normally and provided data on the Earth's trapped radiation belts ...

Energy Technology Data Exchange (ETDEWEB)

An oxidative precipitation reaction of rare-earth chlorides in a LiCl-KCl molten salt was successfully carried out by a lab-scale apparatus. The conversion efficiency of the used rare earth chlorides into the insoluble precipitates was increased with the sparging time and temperature and was affected on oxygen sparger type. In the conditions of 700 .deg. C molten salt temperature and above 540min sparging time, the final conversion efficiencies were over 99% for all the experimented rare-earth chlorides. The hydrodynamic characteristics of an oxygen-molten salt two phase flow system are very important for a co-oxidative precipitation of rare earth elements.

Science.gov (United States)

... Astronomy & Space Biology Chemistry & Materials Computing Earth & Environment Education ... Materials Research Center at the University of Chicago, one of nearly 30 NSF-supported Materials ...

Science.gov (United States)

The rapidly growing field of remote sensing is beginning to supply massive amounts of high resolution imagery of the earth and other planets. ...

Science.gov (United States)

Feb 15, 2010 ... This astronaut photo from January 4, 2010, shows meander scars and oxbow lakes in the floodplain of the Rio Negro in South America.

Science.gov (United States)

Federal regulators were set to vote on a plan to protect deep water corals and other sensitive fish habitats that will likely include a permanent ban on ...

British Library Electronic Table of Contents (United Kingdom)

This study presents new software, called Google Earth-based Optimal HAulage RouTing System (GEOHARTS), to improve the functionality of Google Earth for optimal haulage routing of off-road dump trucks in construction and mining sites. A modified least-cost path algorithm, which is applicable to working areas with both paved and unpaved temporary roads and can consider the effects of terrain relief and curves along a route on the route planning, was proposed and utilized for the software development. GEOHARTS can determine optimal haulage routes between loaders and dumps that ensure the least travel time or fuel consumption of off-road dump trucks and can visualize the results using an embedded 3D render window of Google Earth. The application to the Pasir open-pit coal mine in Indonesia dem...

Science.gov (United States)

Satellite Observations of the Southeast Pacific Intertropical Convergence Zone During 1993-1998, Halpern, D.; Hung, C.-W., Journal of Geophysical Research ? ...

Science.gov (United States)

of Earth Science data and information management capabilities. Dale Schulz/400 . For your exceptional achievement in leading the joint LaRC/GSFC team in ...

Science.gov (United States)

The portion of the Waterpocket Fold illustrated in this image includes layered rocks formed during the Mesozoic Era (~ 250 65 million years ago) the oldest ...

Science.gov (United States)

goals for multisensor co-registration and fusion. 6 - 12.5 Km ..... Beta-Test toolkit for cyclogenesis and early evolution of cyclones ...

Science.gov (United States)

The SHARP cannon. Hydrogen is compressed in the tube on top, the gun barrel is on bottom. When Jules Verne wrote in 1865 "From Earth to the Moon" he ...

Energy Technology Data Exchange (ETDEWEB)

Extraction of rare earths (La, Ce, Pr, Eu, Gd, Er, Yb) from nitrate solutions by melts of carboxylic acids of the C/sub 17/-C/sub 20/ fraction and stearic acid with paraffin, depending on the temperature (60-90 deg), phase contact time and their volume ratio (O:B from 1:5 up to 1:100), pH of the aqueous phase (2-6), rare earth concentration (10/sup -6/-10/sup -3/ m) is studied. It is shown that in the whole concentration range investigated rare earths are extracted quantitatively into the carboxylic acid melt of C/sub 17/-C/sub 20/ fraction at the equilibrium value of pH>=3.8, while into the melt of 0.1 M stearic acid in paraffin at pH>=4.5.

Science.gov (United States)

Aug 23, 2011 ... Earthquakes, Hurricanes and Stubborn Instruments ... And if earthquakes and stubborn instruments aren't enough, there's this giant hurricane ...

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May 11, 2007 ... "Deforestation in the tropics accounts for nearly 20 per cent of carbon emissions due to human activities," Dr. Canadell says. ...

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Features: FOREST, DEFORESTATION, RIO JAMARI Geographic Region: BRAZIL .... Features: DEFORESTATION, TIERRAS BAJAS DEFORESTATION Geographic Region: BOLIVIA ...

Science.gov (United States)

Zinn, John;. Hoerlin,. Herman; and Petschek,. Albert. G.: The Motion of Bomb. Debris. Following the Starfish. Test. Radiation. Trapped in the Earth's ...

Energy Technology Data Exchange (ETDEWEB)

The magnetic susceptibility of the ternary compounds, RPd/sub 2/Si/sub 2/ (where R=Gd, Tb, Dy, Ho and Er) has been measured. GdPd/sub 2/Si/sub 2/ and TbPd/sub 2/Si/sub 2/ order antiferromagnetically at 13 and 20 K respectively; the rest of the compounds do not show clear ordering down to 4.2 K. Palladium carries no moment in these compounds. The De Gennes formula is not obeyed indicating that the exchange interaction between the 4f moments via conduction electrons is not isotropic.

CERN Document Server

We report on aging measurements of a photon detector candidate for the HERA-B RICH. The prototype, a proportional wire chamber operated with TMAE, was mounted on an argon filled test-beam RICH and was aged by UV light at rates we expect in HERA-B. We monitored gain and current continuously, and checked the chamber with Cherenkov photons at regular intervals. The number of detected photons/track (projected to 2.75 m C sub 4 F sub 1 sub 0 in HERA-B) dropped from 26 to 11 after two days of aging - well below the 20 required for pi/K separation. Based on these results, HERA-B decided to use multi-anode PMTs as photon detectors in the RICH.

Energy Technology Data Exchange (ETDEWEB)

Aimed at post-graduate and post-doctoral researchers in geochemistry, this book reflects the rapid changes in the applications of radioactive and stable isotope analysis to a range of geological and geochemical problems. Isotropic chemistry and methods used in mass spectroscopy are discussed initially. The second section deals with radiometric dating methods. The role of isotopes in climate and environmental research is also explored. The book closes with a section on extra-terrestrial matter, geothermometry and the isotopic geochemistry of the Earth`s lithosphere. (UK).

Energy Technology Data Exchange (ETDEWEB)

Clays and zeolites are among the most important of natural dusts by virtue of their occurrence through out the world on the earth`s surface and their important industrial uses. (The 1:1 layer silicates, including the serpentine and kaolin minerals, are not addressed in this chapter.) This chapter provides basic information on a variety of important aspects of each mineral, including crystal structure diagrams of each and references to more detailed discussions. 110 refs., 20 figs.

CERN Document Server

Among the billions of planetary systems that fill the Universe, we would like to know how ours fits in. Exoplanet data can already be used to address the question: How common are Jupiters? Here we discuss a simple analysis of recent exoplanet data indicating that Jupiter is a typical massive planet rather than an outlier. A more difficult question to address is: How common are Earths? However, much indirect evidence suggests that wet rocky planets are common.

Wastenet

...Observatory Edinburgh SkyView Virtual Observatory Solar System Simulator Space Telescope Science Institute Space Weather : A Research Perspective Subaru Telescope Project Two Micron All ...Universities for Research in Astronomy Subjects: space observation DeweyClass: 522 Resource type: index Space Weather : A Research Perspective Documents discussing space weather , the ...elements of near-Earth space, Earth-space meteorology and practical consequences of space weather . Glossary included. Author: National Academy of ...

Energy Technology Data Exchange (ETDEWEB)

When a bipolar HVDC transmission system is operating monopolar using the earth as a return path, it is often desired to divert the return current from the earth to the line from the unused pole. To do so requires either that the system be shut down temporarily or that a dc circuit breaker be used. This paper describes the development of such a new dc circuit breaker, and its application on the Pacific Intertie as a Metallic Return Transfer Breaker (MRTB).

International Nuclear Information System (INIS)

An electric propulsion concept suitable for delivering heavy payloads from low earth orbit (LEO) to high energy earth orbit is proposed. The system consists of a number of pulsed inductive plasma thrusters powered by a 100 kWe space nuclear power system. The pulsed plasma thruster is a relatively simple electrodeless device. It also exhibits adequate conversion to thrust power in the desired I sub sp regime of 1500 to 3000 seconds for optimal payload transfer from low earth to high earth orbit. Because of these features and the fact that the nuclear power unit will be capable of delivering sustained high power levels throughout the duration of any given mission, the system presented appears to be a very promising propulsion candidate for advanced orbital transfer vehicle (OTV) applications. An OTV, which makes use of this propulsion system and which has been designed to lift a 9000-lb payload into ...

Energy Technology Data Exchange (ETDEWEB)

Purpose: To evaluate the initial and mid-term results of a new self-expanding low strut profile nitinol stent for treatment of atherosclerotic lesions stenoses and occlusions in the superficial femoral artery (SFA). Materials and Methods: In 8 patients (4 male, 4 female, mean age 74.8 {+-} 8.8 years) with SFA lesions and non-satisfying results after PTA treatment alone, 10 self-expanding nitinol Xpert stents were deployed via a 4 F sheath. Stent characteristics and handling were graded by the interventionalist. Fontaine classification, duplex flow measurements and ankle brachial index (ABI) at rest and stress were taken prior and one day after stent placement. Patients were followed 3, 6 and 12 months after the procedure obtaining the same parameters at each appointment. Results: Initial stent treatment was successful in all patients. Stent handling and positioning were rated very good and safe. All patients improved clinically by at least one ...

International Nuclear Information System (INIS)

Thin films (1-10 ?m thickness) of nanocomposites (NC) based on organic coordinated compound (OCC) Eu(TTA)2(Ph3PO)2NO3 (where TTA is thenoyl trifluoroacetonate (C8H5F3O2S), Ph3PO - triphenylphosphine (C6H5PO) and polymer-polyvinylpyrrolidone ((C6H9NO)n) (PVP)) were obtained by chemical methods and with different molar ratios into organic polymer matrix. NC have been characterized by measurements of optical transmission, excitation spectra of photoluminescence (PL) and photoluminescence of NC at different concentrations of Eu(TTA)2(Ph3PO)2NO3 in NC. In the optical transmission of NC, the characteristic parameters of NC such as threshold absorbance, dependence on the concentration of the organic coordinated compound in NC, etc., have been determined The displacement of threshold absorption to infrared is observed with increasing of the concentration of the coordination material in NC. The excitation spectrum of photoluminescence of NC led the range from 200 to 400 nm energy at which takes ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

British Library Electronic Table of Contents (United Kingdom)

The need for alternative energy increases steadily???especially due to the climate change and the limited availability of fossil fuels. Geothermal power uses the intrinsic heat which is stored in the accessible part of the Earth???s crust. Its importance among the renewable energy resources originates from the almost unlimited energy supply of the Earth and its independence from external influences such as seasonal or even daily climatic variability. Nevertheless, there are risks which have to be assessed. From a mathematical point of view there are four building blocks of the characterization of deep geothermal systems: seismic exploration, gravimetry, modeling transport processes, and modeling the stress field. In particular, local depletion poses a significant risk during the industrial...

International Nuclear Information System (INIS)

The desire to study negative ion structure and negative ion-photon interactions has spurred the development of ion sources for use in research and industry. The many different types of negative ion sources available today differ in their characteristics and abilities to produce anions of various species. Thus the importance of choosing the correct type of negative ion source for a particular research or industrial application is clear. In this study, the results of an investigation on the production of beams composed of negatively-charged rare-earth ions from a cylindrical-cathode-geometry, cesium-sputter-type negative ion source are presented. Beams of atomic anions have been observed for most of the first-row rare-earth elements, with typical currents ranging from hundreds of picoamps to several nanoamps.

International Nuclear Information System (INIS)

A study has been made of the colour reaction involved in the interaction or rare-earth elements with the reagent orthanyl K, the optimum conditions for the reaction being: pH=4.0-4.5 and lambda=660-670 nm. The ratio of components in the complex is Me:R=1:2. Consideration of the relative optical density values of the complex solutions as a function of the serial number of the rare-earth elements made it possible to recommend orthanyl K as a selective reagent for determining La, Ce, Pr and Nb in a mixture of Tu, Yb, Lu and Y oxides. The molar extinction coefficients, the sensitivity of the reaction and the concentration limits where Beer's law applies were calculated. Lanthanum was determined in a binary mixture with thulium and yttrium. (author).

British Library Electronic Table of Contents (United Kingdom)

Spacecraft studies of the three terrestrial planets with atmospheres have made it possible to make meaningful comparisons that shed light on their common origin and divergent evolutionary paths. Early in their histories, all three apparently had oceans and extensive volcanism; Mars and Earth, at least, had magnetic fields, and Earth, at least, had life. All three currently have climates determined by energy balance relationships involving carbon dioxide, water and aerosols, regulated by solar energy deposition, atmospheric and ocean circulation, composition, and cloud physics and chemistry. This paper addresses the extent to which current knowledge allows us to explain the observed state of each planet, its planetology, climatology and biology, within a common framework. Areas of ignorance...

Science.gov (United States)

Incoming solar energy had to be assimilated to sustain it. .... Roll stability was achieved with an Earth sensor mounted on the directional antenna. .... Once more a rocket becomes the means of producing a vector change in velocity. ...

UK PubMed Central (United Kingdom)

BackgroundDinoflagellates are unicellular, often photosynthetic protists that play a major role in the dynamics of the Earth's oceans and climate. Sequencing of dinoflagellate nuclear...Full Text Available

Science.gov (United States)

Dolores Beasley Headquarters, Washington, DC July 19, 2000 (Phone: 202/358- 1753) Bill Steigerwald Goddard Space Flight Center, Greenbelt, MD (Phone: ...

UK PubMed Central (United Kingdom)

BackgroundGeographic Information Systems (GIS) can provide valuable insight into patterns of human activity. Online spatial display applications, such as Google Earth, can democratise...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Types of disorders in the earth's surface as a result of open pit mining operations are analyzed. Trends for recultivation of lands are defined. Formulas are presented for calculating the economic expediency of the selected direction of recultivation.

UK PubMed Central (United Kingdom)

More than 30 years ago, human beings looked back from the Moon to see the magnificent spectacle of Earth-rise. The technology that put us into space has since been used to assess the damage...Full Text Available

Science.gov (United States)

BAE SYSTEMS Infrared Imaging Systems. MS 209. 2 Forbes Road. Lexington, MA 02421 -7306. (781) 863-3762. (781) 863-4809 (fax) ken.overoye @lmco.com ...

Energy Technology Data Exchange (ETDEWEB)

The Earth`s troposphere and hydrosphere contain abundant naturally generated dust. The ultimate source materials from which the terrestrially produced dust is generated are the various rock types exposed at the Earth`s surface. Natural dust is a composite of (1) lithic, primary mineral grains; (2) mineral grains formed by secondary chemical reactions; (3) volcanic ash and dust; (4) salts from sea sprays; (5) extra-terrestrial dust; and (6) biologic materials. In this paper the various pathways to the natural generation of dust (via the hydrologic cycle) will be discussed, and two geologically well-known natural dust sources will be described, paying particular attention to quantitative measurements of the dusts from these areas. General dust studies that provide data on possibly global background levels will be presented as well.. A few general aspects of the mineralogical characterization of dust particles and a discussion of some of the ...

International Nuclear Information System (INIS)

Instrumental neutron activation analysis (INAA) and radionuclide X-ray fluorescence analysis (RXFA) were used for the determination of rare earth elements. For INAA, solution obtained by sample decomposition was dripped onto filter paper, enclosed and sealed into a polyethylene foil. The sample was activated in reactor WWR-S over a period of 4 to 6 hours with a neutron fluence of 10"1"3cm"-"2. Gamma radiation measurement was carried out with a planar and a coaxial HP-Ge detector in three decay periods. La, Ce, Nd, Sm, Eu, Gd, Tb, Ho, Tm, Yb and Lu were determined. The advantage of the method is its accuracy and high sensitivity, the disadvantage is the time-consuming analysis. The RXFA method was used as a rapid and operative method for the analysis of loose ore samples, aqueous and organic solutions of rare earth elements. For exciting X-ray radiation, "2"4"1Am was used and the radiation of K-lines was detected with a planar Si(Li) detector. ...

Science.gov (United States)

Apr 25, 2010... oil per day were leaking from an oil well in the Gulf of Mexico in late April, following an explosion at an offshore drilling rig on April 20, 2010. ...

UK PubMed Central (United Kingdom)

BackgroundNematoda diverged from other animals between 600–1,200 million years ago and has become one of the most diverse animal phyla on earth. Most nematodes are free-living...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundLake Tanganyika (LT) is the oldest of the African Rift Lakes and is one of the richest freshwater ecosystems on Earth, with high levels of faunal diversity and endemism....Full Text Available

Science.gov (United States)

Features: CHUQUICAMATA, LARGE OPEN PIT MINING OPERATIONS, ROADS, HILLS Center Point Latitude: -22.3 Center Point Longitude: -68.9 (Negative numbers indicate ...

UK PubMed Central (United Kingdom)

From the gross conservation laws of thermodynamics in a convecting material we derive a bound on the ratio of the rate of production of mechanical or magnetic energy to the rate of internal radioactive...Full Text Available

Science.gov (United States)

retrieve detailed aerosol and cloud particle size distribution and shape ...... but on rain types, and hydrometeor characteristics. ..... of ice streams, decreasing sea ice cover in the Arctic, poleward movement of forest cover, and ...

Science.gov (United States)

Sep 9, 2009... a French Ariane rocket successfully launched a new Earth-observing satellite ... The payload is a pair of identical sensors known as "high-resolution ... the resulting image) are activated simultaneously by incoming radiation; ...

Wastenet

... In recent years workers in this field have focused on nucleation by nano-porous materials . This was in part motivated by a theoretical study by Page and Sear (2006) who proposed a two step model for nucleation in pores which suggest that there is ...

National Aeronautics and Space Administration (NASA)

One tiny marine plant makes life on Earth possible: phytoplankton. These microscopic photosynthetic drifters form the basis of the marine food web, they regulate carbon in the atmosphere, and are responsible for half of the photosynthesis that takes place on this planet.

International Nuclear Information System (INIS)

The broad bands in the room-temperature excitation spectra of Sm"3"+-, Dy"3"+- and Tm"3"+-activated Ca-#alpha#-SiAlON phosphors are interpreted as the N"3"--to-rare earth charge transfer transition (CTT). From the energies of the charge transfer transitions and from the optical data presented for the Eu"2"+ ion, the location of the divalent rare earth ion energy levels relative to the valence and the conduction band of Ca-#alpha#-SiAlON is derived. The salient features of the energy-level diagram are shown to be practical in explaining the temperature-dependent variations of the Eu"2"+ and Yb"2"+ luminescence efficiency in Ca-#alpha#-SiAlON. A comparative study pertaining to the nature of the Yb"2"+ and Eu"2"+ ion luminescence in Ca-#alpha#-SiAlON and in SrSi_2O_2N_2 is presented. A tentative energy-level diagram of the trivalent rare earth ions in Ca-#alpha#-SiAlON is also constructed.

Science.gov (United States)

is approximately 327000 km from the Earth's center (58000 km from the Moon's ...... source (figure 7-4). NEXT developed funding requirements for those ...... Code SF 2. 2101 NASA Rd. 1. Houston, TX 77058. Phone: (281) 483-7224 ...

National Aeronautics and Space Administration (NASA)

Expedition 22 Commander Jeff Williams, aboard the International Space Station 220 miles above Earth, responds to questions posted on YouTube concerning the station's orientation, life in space and the recent butterfly experiment.

Science.gov (United States)

Aluminium is an abundant metal consisting about 8 per cent of the earth's crust. It has long been considered as essentially nontoxic and nonabsorbable from the gastrointestinal tract. More recent studies have, however, due to better analytical capabilitie...

Science.gov (United States)

blast should have passed the Earth? Like: Follow APOD on Facebook Tomorrow's picture: whirlpool dust < | Archive | Index | Search | Calendar | RSS | Education | About APOD |...

British Library Electronic Table of Contents (United Kingdom)

Rare-earth oxides are doped into ZnO varistors as grain growth inhibitors for increasing the varistors' voltage gradients. However, their leakage currents become large and their nonlinear coefficients decrease at the same time. The reasonable explanation for such a phenomenon has not yet been available. In this paper, the temperature dependences of varistor samples' leakage currents are investigated, which reveal that the increased leakage currents of ZnO varistors with Y2O3 doping are mainly due to the bypass paths through the intergranular materials at grain corners.

British Library Electronic Table of Contents (United Kingdom)

This paper summarizes the establishment and current development of space activities in the Bolivarian Republic of Venezuela. Space activities in Venezuela are focused on the areas of telecommunications, Earth observation and research on the physical properties of the Earth, and have as a primary goal the satisfaction of social needs. Current development of space activities started in 1999 when the new National Constitution recognized the value of outer space as the common heritage of mankind, and the key role of science and technology in promoting human welfare. The Bolivarian Agency for Space Activities (ABAE) was created in 2007. Its legal framework recognizes three key elements that drive its policy: the participation of society, capacity building and human training, and international c...

Energy Technology Data Exchange (ETDEWEB)

When in resonance, Raman scattering exhibits strong enhancement ranging from four to six orders of magnitude. This physical phenomenon has been applied to remote sensing of the Earth`s atmosphere. With a 16 inch Cassegrain telescope and spectrometer/ CCD-detector system, 70-150 ppm-m of SO{sub 2} in the atmosphere has been detected at a distance of 0.5 kilometer. This system can be used to detect/monitor chemical effluence in the atmosphere by their unique Raman fingerprints. Experimental result together with detailed resonance Raman and atmospheric laser propagation effects will be discussed.

Energy Technology Data Exchange (ETDEWEB)

This patent describes a process for preparing poly(aryl ether ketones) by nucleophilic displacement polymerization in the presence of at least one alkali metal base selected from potassium, rubidium or cesium, and fluoride ions, which comprises adding to the polymerization: (a) an effective amount of at least one metal salt selected from lithium, sodium, alkaline earth or lanthanide chloride, bromide, iodide, sulfate, alkyl or aryl carboxylate, cyanide, borate or phosphate to slow or stop advancement of molecular weight and (b) an end-capping agent.

International Nuclear Information System (INIS)

Protecting Earth and planets against the invasion of 'alien life forms' is not military science fiction, but it is the peaceful daily job of engineers and scientists of space agencies. 'Planetary Protection' is preventing microbial contamination of both the target planet and the Earth when sending robots on interplanetary space mission. It is important to preserve the 'natural' conditions of other planets and to not bring with robots 'earthly microbes' (forward contamination) when looking for 'spores of extra terrestrial life'. The Earth and its biosphere must be protected from potential extraterrestrial biological contamination when returning samples of other planets to the Earth (backward contamination). The NASA-Caltech Laboratory for Planetary Protection of Dr. Kasthuri Venkateswaran at the Jet Propulsion Laboratory (JPL) (California, USA) routinely monitors and characterizes ...

International Nuclear Information System (INIS)

In this work, new LaSi3N5:Ce3+ phosphors have been synthesized by solid-state reaction. Rietveld refinement of the crystal structure of La1-xCexSi3N5 reveals that Ce atoms substituted for La atoms occupy 4a crystallographic positions. Broad emission and excitation bands observed were attributed to the transitions between the doublet ground state of the 4f1 configuration and the crystal field components of the 5d1 excited state. At 77 K, the centroid and crystal field splitting ?cfs of the 5d levels of Ce3+ in LaSi3N5:Ce3+ compounds were valuated at 33.4x103 and 11.3x103 cm-1, respectively. The zero-phonon line and the Stokes shift were measured to be 26.0x103 and 5.0x103 cm-1, respectively.

International Nuclear Information System (INIS)

Optically stimulated luminescence (OSL) and thermoluminescence are observed in polycrystalline RbMgF3:Eu2+ after x-ray, ?-ray, or ? irradiation. The main electron traps are F-centers but there are other unidentified traps. The main hole traps at room temperature are probably Eu3+ and thermal or optical stimulation leads to electron-hole recombination at the Eu3+ site and Eu2+ emissions arising from 6PJ to 8S7/2 and 4f5d(Eg) to 8S7/2 transitions. We find that some of the electron traps can be emptied by infrared stimulation and all of the electron traps can be emptied by white light stimulation. The OSL dark decay is long and exceeds 5 days for traps that are emptied by white light stimulation after initial infrared bleaching. Our results show that this compound can be used as a radiation dosimeter for intermediate dose levels where the 87Rb self-dose does not significantly affect the dose reading.

International Nuclear Information System (INIS)

Laser spectroscopy measurements have been performed on neutron-deficient iridium isotopes. The hyperfine structure and isotope shift of the optical Ir I transition 5d"76s"2 "4F_9_/_2#->#5d"76s6p "6F_1_1_/_2 have been studied for the "1"8"2"-"1"8"9Ir, "1"8"0Ir"m and "1"9"1","1"9"3Ir isotopes. The nuclear magnetic and quadrupole moments were obtained from the hyperfine splitting measurements and the changes of the mean square charge radii from the isotope shift measurements. A large deformation change between "1"8"7Ir and "1"8"6Ir and between "1"8"6Ir"m and "1"8"6Ir"g has been observed.

International Nuclear Information System (INIS)

Using bremsstrahlung, the resonance fluorescence yield has been measured for the 1.836-MeV 2"+_1 level in "8"8Sr. The observed yield corresponds to a level width GAMMA = 2.94 +- 0.15 meV.

UK PubMed Central (United Kingdom)

The beneficial effect of improving yeast redox response by increasing thioredoxin levels has been shown. Decreased lipid and protein oxidation is reflected in an increased biomass yield. In addition,...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

The first measurement of the pn{yields}d{omega} total cross-section has been achieved at mean excess energies Q{approx}28 and 57 MeV by using a deuterium cluster-jet target. The momentum of the fast deuteron was measured in the ANKE spectrometer at COSY-Juelich and that of the slow ''spectator'' proton (p{sub sp}) from the pd{yields}p{sub sp}d{omega} reaction in a silicon telescope placed close to the target. The cross-sections lie above those measured for pp{yields}pp{omega} but seem to be below theoretical predictions. (orig.)

International Nuclear Information System (INIS)

Correct prediction of the fission products inventory in irradiated nuclear fuels is essential for accurate estimation of fuel burnup, establishing proper requirements for spent fuel transportation and storage, materials accountability and nuclear forensics. Such prediction is impossible without accurate knowledge of neutron induced fission yields. The uncertainty of the fission yields reported in the ENDF/B-VII.0 library is not uniform across all of the data and much of the improvement is desired for certain fissioning isotopes and fission products. We discuss our measurements of cumulative fission yields in nuclear fuels irradiated in thermal and fast reactor spectra using Inductively Coupled Plasma Mass Spectrometry. (author)

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

The wet and dry venom yields for most Australian native dangerous snakes and a number of non-Australian species are presented. Snakes from the Pseudonaja genus yielded higher than previously published amounts and suggest reconsideration be given to increasing the volume of antivenom in each vial. Higher percentage solids were obtained from venoms from the 4 cobra species (Naja) and Pseudechis genus included in this series. PMID:16937075

Energy Technology Data Exchange (ETDEWEB)

Effects of gamma irradiation on hygienic quality and extraction yields in twenty-one kinds of Korean medicinal herbs were investigated. Gamma irradiation at 5-10 kGy inactivated contaminating microorganisms. The total extraction yield in fifteen kinds of the investigated medicinal herbs increased by 5-25% by a dose of 10 kGy. (author)

Science.gov (United States)

The current methods used by the tissue analysis program at LASL for the determination of americium and plutonium in autopsy tissue are described. Problems affecting radiochemical yield are discussed. Included are problems associated with sample preparation, separation of plutonium from large amounts of bone ash, and reagent contamination. The average /sup 242/Pu tracer yield for 1800 Pu determinations is 78 +- 12%. The average /sup 242/Am tracer yield is 85 +- 7% for 40 determinations.

International Nuclear Information System (INIS)

Sputter-removal rates of overlayer and interfacial species on silicon are analyzed to determine sputtering yields for the species involved. Sputtering yields up to two orders of magnitude lower than those measured for silicon are found, and the results are interpreted in terms of a cascade mixing process which continually reburies much of the overlayer material beyond the escape depth of the sputtered atoms.

Energy Technology Data Exchange (ETDEWEB)

Earth`s history has been witness to recurrently alternating phases of catastrophic evolution and dominant tectonic deformations, contractions and extension of rifting and spreading leading to quasi-cyclic changes in sedimentary environment and various earth processes. Recent studies have shown quasi-periodicities of 32{+-}2 Million years (Myr) in various endogenic (geomagnetic reversals, magmatic events, mantle convection, various tectonic activities, climate change and biological extinctions) and exogenic (impact catering) processes indicating a remarkable kinship. A time series analysis is presented of the available CO{sub 2} record over the past 250 Myr decoded from global CaCO{sub 3} accumulation rates in sedimentary environment. The time series analysis reveals an intriguing evidence of a dominant periodicity of 33{+-}2 Myr which matches closely with a `common catastrophic periodicity` of 32 Myr identified in various terrestrial and ...

Energy Technology Data Exchange (ETDEWEB)

The renewed CDF II experiment recently re-started data taking. The data collected lately already provides insight in the heavy flavor capabilities of this p{bar p} experiment. As a benchmark of these possibilities we present two preliminary results: the measurement of the branching fractions BR(D{sup o} {yields} {pi}{sup +}{pi}{sup -}) and BR(D{sup o} {yields} K{sup +}K{sup -}) relative to BR(D{sup o} {yields} K{sup {+-}} {pi}{sup {-+}}) and the measurement of the invariant mass difference between D{sub s}{sup {+-}} {yields} {phi}{pi}{sup {+-}}, {phi} {yields} K{sup +}K{sup -} and D{sup {+-}} {yields} {phi}{pi}{sup {+-}}, {phi} {yields} K{sup +}K{sup -}. The preliminary results are BR(D{sup o} {yields} {pi}{sup +}{pi}{sup -})/BR(D{sup o} {yields} K{sup {+-}} {pi}{sup {-+}}) = 3.37 {+-} 0.20(stat) ...

Energy Technology Data Exchange (ETDEWEB)

The interpretation of soil amelioration experiments with peanuts is made difficult by the unpredictibility of the crop and by the many factors altered when ameliorating acid soils. The present study was conducted to investigate the effects of lime and gypsum applications on peanut kernel yield via the three first order yield components, pods per ha, kernels per pod, and kernel mass. On an acid medium sandy loam soil (typic Plinthustult), liming resulted in a highly significant kernel yield increase of 117% whereas gypsum applications were of no significant benefit. As indicated by path coefficient analysis, an increase in the number of pods per ha was markedly more important in increasing yield than an increase in either the number of kernels per pod or kernel mass. Furthermore, exch. Al was found to be particularly detrimental to pod number. It was postulated that poor peanut ...

International Nuclear Information System (INIS)

Silicon nitride-based ceramics behavior is strongly influenced by microstructural parameters, which, in turn are determined by chosen densification method. Highly covalent Si-N bond hind are the silicon nitride densification. Therefore, metal oxides are used in order to get high density. However, such oxides must be carefully selected, because they affect the general macroscopic properties of sintered bodies. In the present work, the viability of rare earth concentrate use to produce #beta#--Si_6_-_xAl_xO_xN_8_-_x and its effect on mechanical properties of the sintering ceramics are studied. Additive composition, heating rate, soaking time and sintering temperature were took as variables. Hardness, fracture toughness, Young's modulus and flexural strength were investigated. Lattice parameter compositional dependence and secondary phases crystallized after past-sintering heat treatment were also determined. The results show that rare earth ...

CERN Document Server

In this paper, we first calculate the realistic Earth matter effects on the detection of type II supernova neutrinos at the Daya Bay reactor neutrino experiment which is currently under construction. It is found that the Earth matter effects depend on the neutrino incident angle \\theta, the neutrino mass hierarchy \\Delta m_{31}^{2}, the crossing probability at the high resonance region inside the supernova, P_H, the neutrino temperature, T_{\\alpha}, and the pinching parameter in the neutrino spectrum, \\eta_{\\alpha}. We give the expression for the dependence of P_H on the neutrino mixing angle \\theta_{13}. With this we obtain the relations between \\theta_{13} and the event numbers for various reaction channels of supernova neutrinos. Using these relations, we propose a possible way to measure \\theta_{13} smaller than 1.5^\\circ. Such a sensitivity cannot be achieved by the Daya Bay neutrino experiment (the sensitivity of the Daya Bay ...

International Nuclear Information System (INIS)

We have begun the ExploreNEOs project in which we observe some 700 Near-Earth Objects (NEOs) at 3.6 and 4.5 ?m with the Spitzer Space Telescope in its Warm Spitzer mode. From these measurements and catalog optical photometry we derive albedos and diameters of the observed targets. The overall goal of our ExploreNEOs program is to study the history of near-Earth space by deriving the physical properties of a large number of NEOs. In this paper, we describe both the scientific and technical construction of our ExploreNEOs program. We present our observational, photometric, and thermal modeling techniques. We present results from the first 101 targets observed in this program. We find that the distribution of albedos in this first sample is quite broad, probably indicating a wide range of compositions within the NEO population. Many objects smaller than 1 km have high albedos (?>0.35), but few objects larger than 1 km have high albedos. This ...

Energy Technology Data Exchange (ETDEWEB)

A low pressure nuclear thermal rocket (LPNTR) is configured to meet the requirements of a nuclear stage for manned Mars exploration. Safety, reliability and performance are given equal consideration in selecting the stage configuration. Preliminary trade studies are conducted to size the engine thrust and determine the thrust chamber pressure. A weight breakdown and mechanical configuration for the selected LPNTR concept are defined. A seven engine stage configuration is selected which gives a two engine out capability and eliminates the need for engine gimbaling. The stage can be ground assembled and launched as a unit including tankage for trans Earth injection and Earth orbital capture. The tankage is configured to eliminate the need for an inert shield. The small engine will be cheaper to develop than a single engine providing full thrust, and will be compatible with stages for Earth orbital, Lunar and deep space ...

Science.gov (United States)

Biofuels may contribute to both rural economic development and climate change mitigation and adaptation. The Gota Verde Project in Yoro, Honduras, attempts to demonstrate the technical and economic feasibility of small-scale biofuel production for local use by implementing a distinctive approach to feedstock production that encourages small farm sizes, mixed cropping of biofuel feedstock from Jatropha and food crops, particularly corn and beans, grown side by side on the same farmland and the total involvement of small rural farmers. But is the project sustainable? Using EC-Assess, the Earth Charter ethics-based assessment tool, to assess the sustainability of this project, the author found that in some assessment categories the actions surpassed the intended objectives, showing that the project was achieving certain Earth Charter goals without specifically stating its intention to address them. (Contains 3 images, 3 figures and 2 notes.)

International Nuclear Information System (INIS)

Three new phases with compositions, LaSr_2FeTiO_7, NdSr_2FeTiO_7 and GdSr_2FeTiO_7, were prepared by the traditional ceramic method. Lazy-Pulverix analysis of the X-ray diffraction data suggests that the phases crystallize in the RP-type (n = 2) structure in the space group, I4/mmm. The cell dimensions along the c-axis decrease with decrease in size of the rare earth ions. Electrical resistivity, as a function of temperature, shows that the materials are insulators and the resistivity decreases with decrease in the size of the rare earth ion, which is attributed to increase in the three-dimensional character. (author)

British Library Electronic Table of Contents (United Kingdom)

This work aims to contribute to the understanding of the influence of the ionospheric layer height (ILH) on the thin layer ionospheric model (TLIM) used to retrieve ionospheric information from the GNSS observations. Particular attention is paid to the errors caused on the estimation of the vertical total electron content (vTEC) and the GNSS satellites and receivers inter-frequency biases (IFB), by the use of an inappropriate ILH. The work relies upon numerical simulations performed with an empirical model of the Earth?s ionosphere: the model is used to create realistic but controlled ionospheric scenarios and the errors are evaluated after recovering those scenarios with the TLIM. The error assessment is performed in the Central and the northern part of the South American continents, a re...

Energy Technology Data Exchange (ETDEWEB)

This journal contains the following articles (1) The Grand Challenge of Thermonuclear Ignition--Commentary by Edward I. Moses; (2) Orchestrating the World's Most Powerful Laser--The computer control system for the National Ignition Facility will soon have about 1.4-million lines of code running on more than 750 computers; (3) A Randon Walk through Time and Space--Albert einstein's 1905 papers on Brownian motion, random fluctuations, and statistical mechanics are fundamental to many Livermore research projects; (4) The Search for Methane in Earth's Mantle--Scientists are discovering that Earth's mantle may have untapped reserves of methane; and (5) Testing the Physics of Nuclear Isomers--Results from a tri-laboratory project contradict claims of accelerated release of energy from the nuclear isomer hafnium-178.

Energy Technology Data Exchange (ETDEWEB)

The use of selective additives such as MgO as a sintering aid and a rare earth oxide as a grain growth inhibitor, has allowed the manufacture of beryllia ceramics having close to theoretical density. The grain size and grain size distribution can be controlled by an optimum firing schedule leaving a remnant porosity which is extremely fine (0.2 {mu}m). This structure is compared with conventional BeO ceramics, densified by liquid phase sintering, which develops a glassy grain boundary and retains large pores up to 3 {mu}m. The significantly improved strength properties, extremely fine pores,the 'pinning effect' of rare earth oxide, and the superior surface finish both in the as-fired and polished state are discussed in relation to the micro-structure. (orig.).

Energy Technology Data Exchange (ETDEWEB)

This invention pertains to a light weight underground pipe or cable installing device adapted for use in a narrow and deep operating trench. More particularly this underground pipe installing device employs a pair of laterally movable gates positioned adjacent the bottom of the operating trench where the earth is more solid to securely clamp the device in the operating trench to enable it to withstand the forces exerted as the actuating rod is forced through the earth from the so-called operating trench to the target trench. To accommodate the laterally movable gates positioned adjacent the bottom of the narrow pipe installing device, a pair of top operated double-acting rod clamping jaws, operated by a hydraulic cylinder positioned above the actuating rod are employed.

Energy Technology Data Exchange (ETDEWEB)

In order to promote environmental damage monitoring and environmental impacts assessment caused by mining in China, the most significant project that uses advanced Earth Observation technology to assess environmental impacts caused by mining, namely MINEO (assessment and monitoring the environmental impact of mining activities in Europe using advanced Earth Observation technology) was introduced and its enlightenment to China were investigated. It was proposed that an integrated technical framework of monitoring environmental impacts caused by mining be designed, quantitative inversion of biological and environmental parameters from RS data be emphasised, hyperspectral Remote Sensing be applied, RS and GIS be integrated with professional models, multi-object applications of RS be implemented, and related standards and specification be drawn up based on typical case study sites. 23 refs., 1 fig.

Energy Technology Data Exchange (ETDEWEB)

Many modern military systems used for communications, command and control, navigation, and surveillance depend on reliable and relatively noise-free transmission of radiowave signals through the earth`s ionosphere. Small-scale irregularities in the ionospheric density can cause severe distortion, known as radiowave scintillation, of both the amplitude and phase of these signals. The WBMOD computer program can he used to estimate these effects on a wide range of systems. The objective of this study is to investigate improvements to the WBMOD model based on extensive data sets covering both the equatorial and high-latitude regimes. This report summarizes the work completed during the third year of this project, which includes completion of the new model for the high-latitude (auroral and polar cap) region of the WBMOD model.

British Library Electronic Table of Contents (United Kingdom)

In order to reduce the number of surface mining accidents related to low visibility conditions and blind spots of trucks and to provide 3D information for truck drivers and real time monitored truck information for the remote dispatcher, a 3D assisted driving system (3D-ADS) based on the GPS, mesh-wireless networks and the Google-Earth engine as the graphic interface and mine-mapping server, was developed at Virginia Tech. The research results indicate that this 3D-ADS system has the potential to increase reliability and reduce uncertainty in open pit mining operations by customizing the local 3D digital mining map, constructing 3D truck models, tracking vehicles in real time using a 3D interface and indicating available escape routes for driver safety.

International Nuclear Information System (INIS)

Spectrophotometry was used to study the conditions under which three-component complexes are formed of rare-earth elements (REE) with aminopolycarboxylic complexes and #beta#-diketones; the molar extinction coefficients of the above REE complexes were also found. A procedure is suggested for determining REE in chromatographic eluates with lower boundary of the contents determined being at 0.6-1.5 #mu#g/ml (Pr, Nd, Ho and Er) and 5-7 #mu#g/ml (Sm and Tm) with account for oxides. Luminescent techniques were also suggested for determining terbium in the presence of EDTA and terbium in an eluate containing EDTA and oxyethyl ethylene diamine triacetic acid, both acids being characterized by a relative standard deviation equal to 0.015-0.03.

CERN Document Server

We compare the metallicities of stars with radial velocity planets to the metallicity of a sample of field dwarfs. We confirm recent work indicating that the stars-with-planet sample as a whole is iron rich. However, the lowest mass stars tend to be iron poor, with several having [Fe/H]0.48) that contributes to but does not explain the mass-metallicity trend in the stars-with-planets sample. We use Monte Carlo models to show that adding an average of 6.5 Earth masses of iron to each star can explain both the mass-metallicity and the age-metallicity relations of the stars-with-planets sample. However, for at least one star, HD 38529, there is good evidence that the bulk metallicity is high. We conclude that the observed metallicities and metallicity trends are the result of the interaction of three effects; accretion of about 6 Earth masses of iron rich material, selection effects, and in some cases, high intrinsic metallicity.

Energy Technology Data Exchange (ETDEWEB)

This study reports the observation of the decays B{sup 0}{yields}D{sup (*)+}{sub S}{pi}{sup -} and B{sup 0}{yields}D{sup (*)-}K{sup +} in a sample of 230 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} events collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} storage ring, located at the Stanford Linear Accelerator Center. The branching fractions {beta}(B{sup 0} {yields} D{sup +}{sub S}{pi}{sup -}) = (1.3 {+-} 0.3 (stat) {+-} 0.2 (syst)) x 10{sup -5}, {beta}(B{sup 0} {yields} D{sup +}{sub S}K{sup +}) = (2.5 {+-} 0.4 (stat) {+-} 0.4 (syst)) x 10{sup -5}, {beta}(B{sup 0}{yields}D{sup (*)+}{sub S}{pi}{sup -}) = (2.8 {+-} 0.6 (stat) {+-} 0.5 (syst)) x 10{sup -5}, and {beta}(B{sup 0}{yields}D{sup (*)-}K{sup +}) = (2.0 {+-} 0.5 (stat) {+-} 0.4 (syst)) x 10{sup -5} are measured. The significance of the measurements to ...

Energy Technology Data Exchange (ETDEWEB)

Process solvent was hydrogenated in the brown coal liquefaction, to investigate the influence of it on the prethermal treatment and liquefaction. Consequently, it was found that the n-hexane soluble (HS) yield was improved. In this study, capacity of hydrogen transfer from solvent during prethermal treatment and effects of catalyst were investigated. Since prethermal treatment in oil was effective for improving the oil yield in the presence of hydrogen/catalyst or high hydrogen-donor solvent, influence of hydrogen-donor performance of solvent or addition of catalyst on the hydrogenation behavior of coal and the characteristics of products during prethermal treatment were investigated in relation to successive liquefaction results. As a result, it was found that the increase of HS yield was due to the acceleration of conversion of THF-insoluble using high hydrogen-donor solvent and/or by adding catalyst. It was also found ...

Energy Technology Data Exchange (ETDEWEB)

For developing coal liquefaction processes, it is an important problem to improve the light oil yield with increased oil yield. It was previously reported that distillate mainly containing lighter fraction can be produced with high oil yield by reducing the iron/sulfur catalyst addition in slurry, by recycling gas in the process operation, by utilizing these effects, and by using heavy oil as recycling solvent. In this study, the maximum distillate yield of Victorian brown coal was investigated through continuous liquefaction using a bench scale unit. In addition, operation conditions for obtaining sufficient oil yield were investigated under the reduced catalyst addition into one-third. Consequently, it was confirmed that the maximum content of lighter fraction in distillate product was obtained with reduced catalyst addition by using heavy oil as recycling solvent, by adopting new ...

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis of Greek fir wood samples in a fluidized bed reactor was studied. The experimental conditions selected control the yield of gaseous, liquid and solid products. The factors examined were: pyrolysis temperature, mean particle size, pressure, residence time of volatiles, lignin content of biomass and moisture content. The experiments were performed on the basis of a 12-run Plackett-Burman fractional factorial design. Statistical analysis of the data showed that the pyrolysis temperature is the main factor affecting the distribution of the yields of liquids, their phenolic fraction and gases in the range of experimental conditions tested. Empirical expressions were obtained from linear regression giving the yields of liquids, phenols and gases in terms of temperature. The maximum predicted yields were 56 and 12 wt.% on a moisture-free basis at 520 C and 545 C for liquids and phenols, respectively. ...

International Nuclear Information System (INIS)

Doubly-excited 2s-12p-13pnp autoionizing resonance series of Ne atom as well as autoionizing resonances in the 2s region of Na and Mg atoms have been studied with monochromatized synchrotron radiation. Use of charge-separated photoion-yield method allowed us to detect these weak resonances in a clarified way in the yield curves of doubly-charged ions. The observed resonance states have been interpreted with the help of MCDF calculations, and the decay processes of these resonance states are discussed briefly.

Energy Technology Data Exchange (ETDEWEB)

An improved method for the synthesis of (/sup 15/N) 16-Doxyl stearate, a fatty-acid spin label, is reported. The method requires only one mole of (/sup 15/N) 2-amino-2-methyl propanol per mole of methyl keto stearate with an overall yield of about 50%. In contrast, the previous method produced only 1-3% yield. The great improvement in yield was achieved mainly through the reduction of reaction volume which increases the reaction rate by the law of mass action.

Wastenet

... This course is jointly taught between the School of Civil Engineering and the Environment and the School of Ocean and Earth Sciences. Scholarships 2 UK/EU fees only Scholarships are available for the academic year 2010/11. Awards will be given on the basis of merit. Flexible part-time study route available Back to top Home | About Us | Prospective Students |...

Environmental Research Database

DescriptionThis new research programme activity on Urban Atmospheric Science will deliver aspects of the NERC strategy: Next Generation Science for Planet Earth. It has been developed as part of the Environment, Pollution & Human Health theme. Research in the Environment, Pollution & Human Health theme is directed at elucidating key environmental processes that form part of a causal pathway between an environmental hazard and disease outcome, and providing a predictive capability of the risk to human heal [continued...

Energy Technology Data Exchange (ETDEWEB)

The brochure reports on the construction and method of operation of heat pumps: - Efficiency and temperature difference - output figure - circuit processes - saving of primary energy - monovalent and bivalent plants - absorber, earth collectors - heat recovery. (HW) [Deutsch] Die Broschuere berichtet ueber den Aufbau und die Wirkungsweise von Waermepumpen: - Wirkungsgrad und Temperaturdifferenz - Leistungszahl - Kreisprozesse - Einsparung von Primaerenergie - monovalente und bivalente Anlagen - Absorber, Erdkollektoren - Waermerueckgewinnung. (HW)

International Nuclear Information System (INIS)

An internuclear cascade-evaporation code is used to model energy deposition in thin slabs of silicon. This model shows that protons produce a significant number of events with effective Linear Energy Transfer (LET) greater than 8 MeV cm"2/mg and demonstrates that proton testing of microelectronic components can be an effective way to screen devices for low earth orbit susceptibility to heavy ions.

Wastenet

... Rachel has also studied Geological Oceanography at the School of Ocean and Earth Sciences, University of Wales, Bangor, including a year spent at the Institute of Oceanographic Sciences Deacon Laboratory, Surrey, as a student researcher for the British Mid-Ocean Ridge Initiative (BRIDGE). Rachel has authored the following 1 Working Papers: 2002 ecm-2002-05 Towards Integrated Catchment/Coastal Management: Science, Policy ...

International Nuclear Information System (INIS)

SX Holdings Limited intends to establish a rare earths plant at Port Pirie, South Australia. The proposal involves three stages of development, Stage 3 being to develop a monazite cracking plant and associated rare earths separation facility with the capacity to process up to 8,000 t/a of monazite-type ores. The proposed initial capacity is 4,000 t/a. This Draft Environmental Impact Statement relates to Stage 3 and is based on a monazite processing capacity of 8,000 t/a. The justification of the project is given in terms of use and the market for rare earths, the economic and environmental benefits of the proposal, the site selection process, site rehabilitation, and the consequences of not proceeding. A detailed description of the project is given, including the treatment process, site development and facilities, the supply of raw materials, product and waste handling, transport and storage, plant commissioning, operation ...

Wastenet

... The National Oceanography Centre, Southampton is one of the world's leading research centres for the study of ocean and earth sciences. Southampton General Hospital One of the country's leading teaching hospitals and the base for the University's School of Medicine. Winchester School of Art Founded in 1863, Winchester School of Art is based 12 miles (20 kilometres) north of Southampton in the historic city of Winchester,...

Energy Technology Data Exchange (ETDEWEB)

The effect of small misch metal additions (0.25 to 1 wt.%) on the corrosion behaviour of aluminium was studied through electrochemical polarization in 0.1 N inorganic and organic acids at room temperature. It has been observed that rare earth addition improves the corrosion resistance of aluminium. (orig.).

Wastenet

... Electro-Osmotic Pulse (EOP) technology forces moisture to flow through concrete surfaces against the hydraulic gradient when an electric field is applied to an embedded anode system. This flow is initiated by the movement of cations (positively charged ions) present in a porous medium such as concrete toward the negative earth. Water surrounding the cations moves with them. The Corps of Engineers owns and maintains many buried ...

International Nuclear Information System (INIS)

An outline of Manitoba Hydro's Earth Power program was presented. Details of the heat pump market in Manitoba were provided, including details of residential and commercial sales. Total residential heat pump sales amounted to 577 units in 2004, equivalent to over $11.2 million in sales. Commercial installations amounted to approximately $12.7 million. An outline of industry players was presented. The goals of Manitoba Hydro were outlined in relation to geothermal energy and the Power Smart program. Their objectives included increasing awareness of geothermal energy, making heat pumps more accessible, and improving industry infrastructure. Other objectives included educating the public about life-cycle cost implications, residential loans and commercial incentives. To date, the residential power loan has provided financing to over 300 Manitoba home owners for installations, with electrical savings of over 1.34 Gwh and natural gas savings of 279,425 m"3. The program ...

Science.gov (United States)

Design constraints require that as Earth terminal attempting communications with a FLTSATCOM EHF Package (FEP) located onboard a FLTSATCOM satellite be provided with an accurate FEP package. To be precise, the terminal is provided with a coefficient element set from which the ephemeris of a satellite may be computed. This report describes the operation of a user friendly computer program that produces the above mentioned coefficient set so as to provide reference benchmarks from which the ephemeris related operations of the terminal can be judged.

British Library Electronic Table of Contents (United Kingdom)

A tobermorite/hydroxyapatite composite was prepared by hydrothermal treatment using diatomaceous earth, ?-tricalcium phosphate and slaked lime starting materials. The XRD patterns of the composite confirmed that tobermorite and hydroxyapatite were formed after the hydrothermal process. The bending strength of the composite reached a level higher than 9?MPa after the hydrothermal process. The development of the bending strength was due to the formation of tobermorite and hydroxyapatite during the hydrothermal process. The composite had a high specific surface area due to these newly formed crystals.

Energy Technology Data Exchange (ETDEWEB)

This report highlights the significance of the geological sciences to the nation and to society. Discussions include understanding plate tectonics and surface processes, exploring the continental crust, ocean basins and the deep earth, applications of geology to social problems such as mineral resources, waste disposal, siting of critical facilities, geological hazards, water resources management, and coastal zones. The state of health of geological research is also discussed. (ACR)

Wastenet

...ENSO Applications Center (PEAC) Institutional Affiliation: PEAC's core members are The National Oceanic and Atmospheric Administration - Office of Global Programs (NOAA/OGP) The NOAA National Weather Service - Pacific Region (NWS-PR), The University of Hawaii - School of Ocean and Earth Science and Technology UH/SOEST, The University of Guam - Water and Energy Research Institute (UOG/WERI), and a regional association of the USAPI Governments, the Pacific Basin ...

International Nuclear Information System (INIS)

A spectrophotometric study of the extraction with isobutanol of rare-earth elements in the form of complexes with quinoilizarin and N-benzene-N-phenylhydroxylamine has been made. The purpose of the study is to find out whether this reaction can be used in determining the concentration of elements in the presence of other rare-earth elements. In determining the relationship between the pH and light absorption the pH of the solution is measured after the extraction. The extraction of complexes begins at pH approximately 4 and reaches a maximum at pH7-8 (for La) and pH6-9 (for Er). The complexes underge decomposition when pH of the solution increased. The composition of complex compounds is determined by spectrophotometric methods for isomolar series, molar ratios and from the slope of logarithmic plots. Under optimal conditions (pH7.5) aAd at the measured ratio of the component for each ion of rare-earth elements, the molar ...

Energy Technology Data Exchange (ETDEWEB)

Research programs from the following sections and programs are summarized: aquatic ecology, environmental resources, earth sciences, terrestrial ecology, advanced fossil energy program, toxic substances program, environmental impacts program, biomass, low-level waste research and development program, US DOE low-level waste management program, and waste isolation program.

Wastenet

... 01, 2009 | Rate It Marine Technology Society https://www.mtsociety.org/home.aspx emphasizes the importance of marine technology as it applies to global issues, encourages marine technology education and facilitates the use of marine technology in managing marine resources Added: Mar. 11, 2010 |...

International Nuclear Information System (INIS)

Passive dosimeters for personal and area radiation monitor in space have been developed mainly for dosimetry in low-earth-orbit (LEO) radiation environments of Space Shuttles and the International Space Station. The responses of several dosimeters have been evaluated by heavy ions and also its variation for individual dosimeter element. (author)

Energy Technology Data Exchange (ETDEWEB)

We present a study of the crystal field in PrNiAl, NdNiAl, ErNiAl and ErCuAl intermetallic compounds based on inelastic neutron spectroscopy. These compounds crystallize in the ZrNiAl-type hexagonal structure with an orthorhombic symmetry on rare-earth sites. The results are compared with the specific-heat data, and the lower parts of the crystal-field energy-level schemes are determined. (orig.)

Energy Technology Data Exchange (ETDEWEB)

The metabolism of organic matter in the coastal regions of the ocean may significantly affect the oceanic carbon budget. This paper describes the high percentage (30%) of oceanic oxidation that occurs in coastal areas and the impact of this metabolism on the carbon cycle and climate of earth. Organic metabolism in the ocean appears to be a source of carbon dioxide release into the atmosphere. Oxidation in the coastal zone is of special interest, as it is likely influenced by anthropogenic activity. Recommendations for future research on this topic are proposed. 129 refs., 2 figs., 6 tabs.

Environmental Research Database

DescriptionCEH - Quest CCMAP see http://quest.bris.ac.uk/research/themes/CCMAP.html CCMAP (Climate-carbon modelling, assimilation and prediction) Leader: Dr. Eleanor Blyth (CEH, Wallingford) Overview and Goals CCMAP is one of QUEST's Theme 1 projects and is about to be commissioned to the Centre for Ecology and Hydrology at Wallingford. The Principal Investigator will be Dr. Eleanor Blyth, with subcontracts to the Universities of Bristol (Dr. Wolfgang Knorr, Earth Sciences and QUEST; Andy Ridgw [continued...

Wastenet

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International Science & Technology Center (ISTC)

Experimental and Theoretical Study of the Residual Nuclide Production in 40-2600 MeV Proton-Irradiated Thin Targets of ADS Basic Materials

Science.gov (United States)

Nat'l Training Center Contact Us Directory Email Us BLM > Socioeconomic Impacts > Timber Print Page Socioeconomic Impacts from Timber BLM-administered lands yielded $337...

International Nuclear Information System (INIS)

A new evaluation (UKFY2) has been prepared of the independent and cumulative yields of the products of fission induced by thermal, fast, and 14 MeV neutrons in nuclides important for reactor design and operation and for fuel and waste management. Three spontaneously fissioning nuclides were also considered. The evaluation used a database that is considered to be complete up to early 1989. Careful study was made of experimental uncertainties and discrepancies, emphasizing the need for further measurements. Gaps in the data were filled by interpolation and extrapolation, using fits to empirical models. The yields were subsequently adjusted to fit physical constraints of the fissioning process. This paper describes the evaluation, which was submitted and accepted for inclusion in the JEF2 file. The file was produced in January 1990 and a revision of cumulative yield uncertainties distributed in January 1991.

International Science & Technology Center (ISTC)

Elaboration of a Modern Technology for Operational Agrometeorological Soil Moisture Monitoring Spring Wheat, Yield and Disease Damage Forecasting and Recommendations for Plant Protection on the Kazakhstan Territory

Energy Technology Data Exchange (ETDEWEB)

We perform an optimal-observable analysis of the final charged-lepton/b-quark momentum distributions in {gamma}{gamma}{yields}t t-bar {yields}lX/bX for various beam polarizations in order to study possible anomalous t t-bar {gamma}, tbW and {gamma}{gamma}H couplings, which could be generated by SU(2) x U(1) gauge-invariant dimension-6 effective operators. We find optimal beam polarizations that will minimize the uncertainty in determination of those non-standard couplings. We also compare e e-bar and {gamma}{gamma} colliders from the viewpoint of the anomalous-top-quark-coupling determination.

Science.gov (United States)

Evolution in Space Radio Telescopes Reveal Youngest Stellar Corpse Gas Clouds in Whirlpool Galaxy Yield Important Clues Supporting Theory on Spiral Arms Starbust-driven Winds...