WorldWideScience
1

Use of countercurrent liquid chromatography for the preconcentration and separation of inorganic compounds: group extraction of Zr, Hf, Nb, and Ta for their subsequent determination by inductively coupled plasma atomic emission spectroscopy  

International Nuclear Information System (INIS)

The possibility of the group preconcentration of Zr(4), Hf(4), Nb(5), and Ta(5) countercurrent liquid chromatography using extraction systems based on di-2-ethylhexylphosphoric acid N-benzoyl-N-phenylhydroxylamine, and tetraoctylethylenediamine (TOEDA) is studied. A method have been proposed for the group extraction of Zr(4), Hf(4), Nb(5), and Ta(5) from solution of geological samples. At the stage of the preconcentration of Zr(40, Hf(4), Nb(5) and Ta(5) with a 0.1 M solution of TOEDA in chloroform from mixture of oxalic (0.01 M) and hydrochloric (0.1 M) acids, matrix components are eluted with a flow of the mobile phase, Then, upon changing the eluent (2.0 M HCl), the four elements mentioned above are extracted to a small (7-8 mL) eluate fraction. The results of determining Zr, Hf, Nb, and Ta by inductively coupled ...

1997-11-01

2

Luminescent determination of zirconium and hafnium with myricetin  

International Nuclear Information System (INIS)

Reaction of formation of 3, 5, 7, 3', 4', 5' - hexaoxiflavone - myricetin complexes with zirconium and hafnium ions has been the basis for development of luminescent method of determining these elements. Optimum conditions for complexing have been determined. For Hf they are : 8-9 HCl concentration, maximum fluorescence wave length (lambda fl.)of 520 nm, wave length of exciting light (lambda el) of 436 nm, for Zr lambda fl = 536nm, lambda el = 436 nm. Stable fluorescence establishes after 25 min. for Zr and after 15 min for Hf in the presence of 40% ethanol. Usage of various camouflage agents has permitted to attain high selectivity of the method. Possibility for determination of Zr with myricetin in the presence of a 10-time excess of Hf, Cr, Cu, 50-time excess of Mo and Ti is shown. Sensitivity of Zr determination is 2.0x10 #mu#g"-"2/ml, ...

3

High-temperature investigations of the rare earth NZP phosphates R {sub 1/3}Zr{sub 2}(PO{sub 4}){sub 3} (R = La, Nd, Eu, Lu) by drop calorimetry  

Energy Technology Data Exchange (ETDEWEB)

The high-temperature enthalpy increments of the phosphates La{sub 1/3}Zr{sub 2}(PO{sub 4}){sub 3}, Nd{sub 1/3}Zr{sub 2}(PO{sub 4}){sub 3}, Eu{sub 1/3}Zr{sub 2}(PO{sub 4}){sub 3} and Lu{sub 1/3}Zr{sub 2}(PO{sub 4}){sub 3} have been measured by high-temperature drop calorimetry in the temperature range 484.5-1090.7 K. From these results the heat capacity of the studied compounds has been derived.

2007-07-31

4

ZZ MCB63NEA.BOLIB, MCNP Cross Section Library Based on ENDF/B-VI Release 3  

International Nuclear Information System (INIS)

1 - Description of program or function: Continuous energy cross-section data library for the Monte Carlo program MCNP based on the ENDF/B-VI Release 3 evaluated nuclear data library (ACE Format). Format: ACE; Number of groups: Continuous energy; Nuclides (107): H-1, H-2, He-4, Li-6, Li-7, Be-9, B-10, B-11, C-nat, N-14, N-15, O-16, O-17, Na-23, Mg-nat, Al-27, Si-nat, Cl-nat, Ti-nat, Cr-50, Cr-52, Cr-53, Cr-54, Mn-55, Fe-54, Fe-56, Fe-57, Fe-58, Co-59, Ni-58, Ni-60, Ni-61, Ni-62, Ni-64, Zr-90, Zr-91, Zr-92, Zr-94, Zr-96, Zr-nat, Nb-93, Mo-94, Mo-95, Mo-96, Mo-97, Mo-nat, Tc-99, Ru-101, Ru-102, Ru-104, Rh-103, Pd-105, Pd-107, Ag-109, I-129, Xe-131, Cs-133, Pr-141, Nd-143, Nd-145, Pm-147, Sm-147, Sm-149, Sm-150, Sm-151, Sm-152, Eu-153, Gd-154, Gd-155, Gd-156, Gd-157, Gd-158, Gd-160, Hf-174, Hf-176, ...

5

ZZ MCJEF22NEA.BOLIB, MCNP Cross Section Library Based on JEF-2.2  

International Nuclear Information System (INIS)

1 - Description or function: Continuous energy cross-section data library for the Monte Carlo program MCNP based on the JEF-2.2 evaluated nuclear data library (ACE Format). Format: ACE Number of groups: Continuous energy Nuclides (107): H-1, H-2, He-4, Li-6, Li-7, Be-9, B-10, B-11, C-nat, N-14, N-15, O-16, O-17, F-19, Na-23, Mg-nat, Al-27, Si-nat, Cl-nat, Ti-nat, Cr-50, Cr-52, Cr-53, Cr-54, Mn-55, Fe-54, Fe-56, Fe-57, Fe-58, Co-59, Ni-58, Ni-60, Ni-61, Ni-62, Ni-64, Zr-90, Zr-91, Zr-92, Zr-94, Zr-96, Zr-nat, Nb-93, Mo-92, Mo-94, Mo-95, Mo-96, Mo-97, Mo-98, Mo-100, Mo-nat, Tc-99, Ru-101, Ru-102, Ru-104, Rh-103, Pd-105, Pd-107, Ag-109, I-129, Xe-131, Cs-133, Pr-141, Nd-143, Nd-145, Pm-147, Sm-147, Sm-149, Sm-150, Sm-151, Sm-152, Eu-153, Gd-154, Gd-155, Gd-156, Gd-157, Gd-158, Gd-160, Hf-174, Hf-176, ...

6

Crystal field in RNiAl compounds studied by inelastic neutron scattering  

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.)

2002-07-01

7

Crystal field in RNiAl compounds studied by inelastic neutron scattering  

International Nuclear Information System (INIS)

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.)

2002-01-01

8

Trace elements in the Allende meteorite  

International Nuclear Information System (INIS)

New RNAA determinations of Ba, Sr, Zr, U, Re, Pd, Ag, Zn and Se and INAA measurements of Lu are added to published data for 21 other elements in the same suite of ten samples. On the average, 21 refractory elements are not significantly fractionated from one another. The mean of their enrichment factors relative to C1 chondrites is 17.5 +- 0.4, indicating that the high-temperature condensate inclusions represent 5.7 wt% of the total condensable matter. Os, Ir, Ru, Re and most of the W condensed in one or more refractory siderophile element alloys along with small fractions of the Pd, Co, Au and Ag. The bulk of the Eu and Sr condensed in solid solution in melilite. Sc, Zr, Hf, Ta, U and the remaining REE condensed in a phase whose abundance in the inclusions in negatively correlated with that of melilite, either diopside or one or more minor or trace phases, including perovskite. Ba condensed in a different phase, separately ...

1977-01-01

9

CHEMICAL TECHNOLOGY DIVISION. UNIT OPERATIONS SECTION MONTHLY PROGRESS REPORT, FEBRURARY 1963  

Science.gov (United States)

Development of a shear and leach complex for UO/sub 2/-SS clad fuel was continued with major emphasis on the operation of a rotary drum leacher. Flooding data for nozzle plate pulse columns at high A/O ratios are reported. Engineering tests of dissolution of Zr--6% U alloy with HF in molten salt demonstrated a dissolution rate of 0.8 to 1.5 mg/cm/sup 2//min. Subsequent fluorination with 100% F/sub 2/ proceeded at half times of 40 to 135 min. The results of a high level waste calcination (run R-72) made with formaldehyde treated simulated Purex waste are reported. (auth)

1963-10-01

10

ZZ MCB-JEF2.2, MCB Continuous-Energy Neutron Cross Section Libraries for Temperatures from 300 to 1800 K  

International Nuclear Information System (INIS)

1 - Description of program or function: MCB-JEF2.2 is a continuous-energy cross section libraries in ACE Format suitable for the MCB-1C and MCNP codes. Libraries for various materials were generated at six different Temperatures, and cover the energy range up to 20 MeV. Format: ACE. Number of groups: Continuous energy. Nuclides: H-1, H-2, H-3, He-3, He-4, Li-6, Li-7, Be-9, B-10, B-11, C-nat., N-14, N-15, O-16, O-17, Na-23, F-19, Mg-nat., Al-27, Si-nat., P-31, S-32, S-33, S-34, S-36, Cl-nat, K-nat, Ca-nat., Ti-nat, V-nat, Cr-50, Cr-52, Cr-53, Cr-54, Mn-55, Fe-54, Fe-56, Fe-57, Fe-58, Co-59, Ni-58, Ni-59, Ni-60, Ni-61, Ni-62, Ni-64, Cu-nat, Ga-nat, Ge-72, Ge-73, Ge-74, Ge-76, As-75, Se-74, Se-76, Se-77, Se-78, Se-80, Se-82, Br-79, Br-81, Kr-78, Kr-80, Kr-82, Kr-83, Kr-84, Kr-85, Kr-86, Rb-85, Rb-86, Rb-87, Sr-84, Sr-86, Sr-87, Sr-88, Sr-89, Sr-90, Y-89, Y-90, Y-91, Zr-nat, Zr-90, Zr-91, Zr-92, ...

11

WLUP3.0, 69 and 172 Group Cross Section Libraries for WIMS  

International Nuclear Information System (INIS)

Description or function: WLUP contains validated WIMS-D formatted cross section libraries in 69 and 172 energy group structures for nuclear reactor calculations. Materials from recently released evaluated nuclear data libraries are included. The NJOY nuclear data processing system was applied for generating the cross section files following the models and conventions built into the WIMS-D lattice code. The relevant features for the WIMS users are: - Energy group structures: 69 and 172 energy groups. - List of materials: WIMS ID, general information, source of data. - Cross sections: 69 and 172 group plots. - Resonance data: WIMS ID, temperature, background cross sections. - Goldstein-Cohen factors: Goldstein-Cohen lambda values. - Thermal scattering data: thermal scattering laws and P1 matrixes. - Fission spectrum: fission spectrum data. - Burnup data: burnup chains. - Fission product yields: fission yield tables. - Pseudo lumped fission product: Description of pseudo fission product. ...

12

Upgrading low molecular weight hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a process for the conversion of low molecular weight alkanes to higher molecular weight hydrocarbons. It comprises: contacting the low molecular weight alkanes, at an elevated temperature, with oxygen and a catalyst of the formula Zn{sub a}A{sub b}M{sub c}M'{sub d}O{sub x} wherein A is Li, Na, K, or mixtures thereof; M is Al, Ga, Cr, La, Y, Sc, V, Nb, Ta, Cu or mixtures thereof; M' is Cs, Rb, Mg, Ca, Sr, Ba, Sm, Pb, Mn, Sb, P, Sn, Bi, Ti, Zr, Hf, or mixtures thereof; a if from about 1 to about 20; b is from about 0.1 to about 20; c is from about 0 to about 5 d is from about 0 to about 20, and x is a number needed to fulfill the valence requirements of the other elements; provided that at least one c and d is a t least 0.1; and when M' is Sn, c must be at least 0.1.

1989-12-12

13

Recent advances and developments in refractory alloys  

Energy Technology Data Exchange (ETDEWEB)

Refractory metal alloys based on Mo, W, Re, Ta, and Nb (Cb) find applications in a wide range of aerospace applications because of their high melting points and high-temperature strength. This paper, presents recent progress in understanding and applications of these alloys. Recent studies to improve the oxidation and mechanical behavior of refractory metal alloys, and particularly Nb alloys, are also discussed. Some Re structures, for extremely high temperature applications (> 2000C), made by CVD and P/M processes, are also illustrated. Interesting work on the development of new W alloys (W-HfC-X) and the characterization of some commercial refractory metals, e.g., K-doped W, TZM, and Nb-1%Zr, continues. Finally, recent developments in high temperature composites reinforced with refractory metal filaments, and refractory metal-based intermetallics, e.g., Nb{sub 3}Al, Nb{sub 2}Be{sub 17}, and MoSi{sub 2}, are briefly described.

1993-11-01

14

Quinary metallic glass alloys  

Energy Technology Data Exchange (ETDEWEB)

At least quinary alloys form metallic glass upon cooling below the glass transition temperature at a rate less than 10.sup.3 K/s. Such alloys comprise zirconium and/or hafnium in the range of 45 to 65 atomic percent, titanium and/or niobium in the range of 4 to 7.5 atomic percent, and aluminum and/or zinc in the range of 5 to 15 atomic percent. The balance of the alloy compositions comprise copper, iron, and cobalt and/or nickel. The composition is constrained such that the atomic percentage of iron is less than 10 percent. Further, the ratio of copper to nickel and/or cobalt is in the range of from 1:2 to 2:1. The alloy composition formula is: (Zr,Hf).sub.a (Al,Zn).sub.b (Ti,Nb).sub.c (Cu.sub.x Fe.sub.y (Ni,Co).sub.z).sub.d wherein the constraints upon the formula are: a ranges from 45 to 65 atomic percent, b ranges from 5 to 15 atomic percent, c ranges from 4 to 7.5 atomic percent, d comprises the balance, d.multidot.y is less than 10 atomic percent, and x/z ...

1998-01-01

15

Amorphous metal alloy compositions for reversible hydrogen storage and electrodes made therefrom  

Energy Technology Data Exchange (ETDEWEB)

This patent describes an energy storage device. It comprises: a working electrode, a counter electrode, electrically isolated from the working electrode; an electrolyte in contact with the working electrode and the counter electrode, and means for collecting electrical current therefrom; the working electrode consisting essentially of an amorphous metal alloy of the formula: A{sub {ital a}}M{sub {ital b}}M{prime}{sub {ital c}}, wherein A is at least one metal selected from the group consisting of Ag, Hg and Pt; M is at least one metal selected from the group consisting of Pb, Cu, Cr, Mo, W, Ni, Al, Co, Fe, Zn, Ru, Cd and Mn; M{prime} is at lest one of the elements selected from the group consisting of Ca, Mg, Ti, Zr, Hf, V, Nb and Ta; and wherein a ranges from about 0.005 to about 0.80; b ranges from 0.05 to about 0.70; and c ranges from about 0.08 to about 0.95.

1990-05-08

16

ZZ KASHIL-E6, 175 N, 42 Gamma Groups Cross Sections in MATXS Format Based on ENDF/B-VI.5 for Shielding Applications  

International Nuclear Information System (INIS)

1 - Description of program or function: Format: MATXS; Number of groups: 175 neutron-, 42 photon-groups; 176 Nuclides: 1-H-1, 1-H-2, 1-H-3, 2-He-3, 2-He-4, 3-Li-6, 3-Li-7, 4-Be-9, 5-B-10, 5-B-11, 6-C- nat., 7-N-14, 7-N-15, 8-O-16, 8-O-17, 9-F-19, 11-Na-23, 12-Mg-nat., 13-Al-27, 14-Si-nat., 14-Si-28, 14-Si-29, 14-Si-30, 15-P-31, 16-S-32, 17-Cl-nat., 19-K-nat., 20-Ca-nat., 21-Sc-45, 22-Ti-nat., 23-V-nat., 24-Cr-50, 24-Cr-52, 24-Cr-53, 24-Cr-54, 25-Mn-25, 26-Fe-54, 26-Fe-56, 26-Fe-57, 26-Fe-58, 27-Co-59, 28-Ni-58, 28-Ni-60, 28-Ni-61, 28-Ni-62, 28-Ni-64, 29-Cu-63, 29-Cu-65, 31-Ga-nat., 39-Y-89, 40-Zr-nat., 40-Zr-90, 40-Zr-91, 40-Zr-92, 40-Zr-94, 40-Zr-96, 41-Nb-93, 42-Mo-nat., 46-Pd-102, 46-Pd-104, 46-Pd-105, 46-Pd-106, 46-Pd-108, 46-Pd-110, 47-Ag-107, 47-Ag-109, 48-Cd-106, 48-Cd-108, 48-Cd-110, 48-Cd-112, 48-Cd-113, 48-Cd-114, 48-Cd-116, 49-In-nat., 53-I-127, ...

17

Excitation functions for proton-induced reactions on natural hafnium: Production of {sup 177}Lu for medical use  

Energy Technology Data Exchange (ETDEWEB)

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.

2009-11-15

18

Excitation functions for proton-induced reactions on natural hafnium: Production of "1"7"7Lu for medical use  

International Nuclear Information System (INIS)

There is an increasing interest in using radioisotopes of rare earth elements for internal radiotherapy and for imaging in nuclear medicine. "1"7"7Lu is one of the promising radionuclides. This article reports on the first measurements of the excitation function for the production of "1"7"7Lu with proton-beam energies up to 17 MeV on natural hafnium targets. The experimental cross sections for the reaction "n"a"tHf(p,x)"1"7"7Lu 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 "1"7"7Lu. Measured production cross sections of "1"7"5","1"7"6","1"7"7","1"7"8Ta on the same target are also presented.

2009-11-01

20

Tribromo-chlorophosphonazo used for photospectrometric determination of total rare earth in high-level liquid waste  

International Nuclear Information System (INIS)

The Procedure determining the concentrations of total rare earth and their determination with a new reagent, tribromochlorophosphonazo (CPA-tB), that is 7-[1-(2, 4, 6-tribromo-phenyl) azo]-2-[1-(2-phosphono-4-chloro-phenyl) azo]-chromotropic acid, in high-level liquid waste and some characters of CPA-tB are studied. CPA-tB and its complexes of rare earth elements are stable in the glycol-H_2O system. Adding glycol shifts the absorption spectrum to left and increases the molar extinction coefficient. The molar extinction coefficients are respectively 7.16 x 10"4 (Y), 11.9 x 10"4 (La), 11.7 x 10"4 (Ce, Pr), 11.9 x 10"4 (Nd), 11.6 x 10"4 (Sm, Eu), 11.4 x 10"4 (Gd) and 11.4 x 10"4 (RE) in the glycol-H_2C_2O_4-H_3PO_4-H_2O system at 643 nm. Th interferes severely the determination of total rare earth, and other elements, U(<100 #mu#g), Al(<20 #mu#g), Fe(<400 #mu#g), Ni,Zr(<100 #mu#g respectively) ...

1992-01-01

21

Dismembered Archean ophiolite in the SE. Wind River Mountains, Wyoming  

Energy Technology Data Exchange (ETDEWEB)

Ophiolitic rocks occur as wall rocks of the 2.7 Ga Louis Lake batholith near Atlantic City, Wyoming. All of the Archean rocks are strongly deformed and metamorphosed to a greenschist and amphibolite facies, but relict structures and textures are commonly preserved. These include the following, from west to east: (1) metadiabase with rare coarse-grained metagabbro; (2) ultramafic rocks and metagabbro; (3) amphibolite, locally pillowed, overlain(.) by pelitic schist, banded iron formation, and quartzite; and (4) pillow lavas, massive sills or flows, and minor metasedimentary rocks. Slice 1 locally contains parallel dike margins and rare metagabbro screens; these features suggest that it may represent a sheeted dike complex. Slice 2 locally contains ultramafic rocks having relict cumulus textures and igneous layering, corresponding to the cumulus portion of an ophiolite. The pillow lavas of slice 4 and possibly slice 3 are interpreted as ...

1985-01-01

22

In situ isotopic analyses of U and Pb in zircon by remotely operated SHRIMP II, and Hf by LA-ICP-MS: an example of dating and genetic evolution of zircon by 176Hf/177Hf from the Ita Quarry in the Atuba Complex, SE, Brazil  

International Nuclear Information System (INIS)

Remotely-operated SHRIMP dating of zircon is an interesting alternative for dating of zircon crystals. Although it does not represent any technical progress of the geochronological method using the U-Pb system in zircon it is a very useful and cheap facility. The procedure was first used for mass spectrometric analyses involving two international laboratories in Sao Paulo, Brazil and Beijing, China. It was applied to samples of three gneiss-migmatitic rocks from the Ita quarry in the Atuba Complex (located between the Luis Alves and the Apiai Domain) to test previous controversial hypotheses about its evolution. The presence of important archaean and paleo proterozoic components in the complex is confirmed by analyses of zircon found in probably neo proterozoic leucosomes. Diorite intrusion also occurred during the neo proterozoic, associated with the 0.6Ga continental collisions involved in the assembly of Gondwana. The determination of Hf isotope ratios by ...

2009-10-01

23

High temperature strengthening mechanism of hafnium carbide in a tungsten-rhenium matrix  

Energy Technology Data Exchange (ETDEWEB)

The interrelationship between the testing temperature and HfC strength increment of an arc-melted W-3.6Re-0.4HfC was determined from 1950 K to 2980 K in a vacuum of better than 1.3{times}10{sup {minus}5} Pa (10{sup {minus}7} torr). The present research was focused on the characteristic temperature at which the rapid coarsening of HfC particles occurred and the effect of the second-phase particle size on the high temperature strength properties of this material. It was found that the HfC particle strengthening was effective in a W-Re matrix up to a characteristic temperature of 2450 K in the short-term tensile test. Carbon was found to be the rate-limiting solute in the HfC particle growth. The strength of HfC strengthened alloy at temperature above 0.5 T{sub m} is proportional to the square root of particle volume fraction. The yield strengths of ...

1991-01-01

24

High temperature strengthening mechanism of hafnium carbide in a tungsten-rhenium matrix  

International Nuclear Information System (INIS)

The interrelationship between the testing temperature and HfC strength increment of an arc-melted W-3.6Re-0.4HfC was determined from 1950 K to 2980 K in a vacuum of better than 1.3x10"-"5 Pa (10"-"7 torr). The present research was focused on the characteristic temperature at which the rapid coarsening of HfC particles occurred and the effect of the second-phase particle size on the high temperature strength properties of this material. It was found that the HfC particle strengthening was effective in a W-Re matrix up to a characteristic temperature of 2450 K in the short-term tensile test. Carbon was found to be the rate-limiting solute in the HfC particle growth. The strength of HfC strengthened alloy at temperature above 0.5 T_m is proportional to the square root of particle volume fraction. The yield strengths of W-3.6Re-0.26HfC ...

1991-01-06

25

Hydrogen-induced phase transformations in H-storing alloys of zirconium  

Energy Technology Data Exchange (ETDEWEB)

In this work, the ability of a number of Zr-containing intermetallic compounds with the Zr{sub 2}Me stoichiometry, including Zr{sub 2}Fe, Zr{sub 2}Ni, Zr{sub 2}Co and Zr{sub 4}Fe{sub 2}O{sub 0.6}, to participate in the Hydrogenation-Disproportionation-Desorption-Recombination process was investigated, revealing for the first time that the HDDR route can be employed successfully for all these compounds. 24 refs.

1998-07-01

26

Decay of "1"7"7Ta to levels of "1"7"7Hf  

International Nuclear Information System (INIS)

... intermediate mass nuclei isotopes leptonic decay nuclei odd-even nuclei

1973-10-01

27

Cation exchange separation of trace amounts of {sup 203}Hg and {sup 181}Hf  

Energy Technology Data Exchange (ETDEWEB)

A radiochemical method of separation of {sup 203}Hg from {sup 181}Hf is described. The method involves separation by Dowex 50W- X 8, 100-200 mesh, cation exchange resin using 1 M hydrochloric acid as the eluant. The chemical yield for the separation of mercury is > 85% and the decontamination factor is >10{sup 4}. The {sup 181}Hf can be eluted from the column by 4 M HCl.

2000-02-01

28

Delayed Hydride Cracking Mechanism in Zirconium Alloys and Technical Requirements for In-Service Evaluation of Zr-2.5Nb Tubes with Flaws  

International Nuclear Information System (INIS)

In association with periodic inspection of CANDU nuclear power plant components, Canadian Standards Association issued CSA N285.8 in 2005 as technical requirements for in-service evaluation of zirconium alloy pressure tubes in CANDU reactors. This first version, CSA N285.8 involves procedures for, firstly, the evaluation of pressure tube flaws, secondly, the evaluation of pressure tube to calandria tube contact and, thirdly, the assessment of a reactor core, and material properties and derived quantities. The evaluation of pressure tube flaws includes delayed hydride cracking evaluation the procedures of which are stipulated based on the existing delayed hydride cracking models. For example, the evaluation of flaw-tip hydride precipitation during reactor cooldown involves a procedure to calculate the equilibrium hydrogen equivalent concentration in solution at the flaw tip, Htipas follows: Htip=Hfexp[- (VH delta no.)/RT], where Hf is the total bulk hydrogen ...

2007-05-10

29

Anisotropic Nd{endash}Fe{endash}B bonded magnets made from HDDR powders (invited)  

Energy Technology Data Exchange (ETDEWEB)

Anisotropic Nd{endash}Fe{endash}B magnet powders can be produced by the hydrogenationdecomposition-desorption-recombination (HDDR) process from Nd{endash}Fe@ xnB{endash}Co{endash}M ({ital M}=Ga, Zr, Nb, Hf, and Ta) alloys. The present status of those HDDR powders and the bonded magnets made from them are reviewed with regards to the powder particle size dependence of their magnetic properties, their magnetic thermal stability, and their magnetization behavior. The results of a mechanistic study on the recombination step are also presented. The magnetic properties of the anisotropic HDDR powder depend relatively little on the powder particle size. Bonded magnets with a density of {approximately}6.20 g/cm{sup 3} and a BH{sub max} of 18.5{endash}20.5 MGOe can be produced from anisotropic HDDR powders with particle sizes of below 300 {mu}m diam. The temperature coefficient of the intrinsic coercive force {sub {ital iH}}{sub {ital c}}, of the bonded ...

1996-04-01

30

Synthesis, structure and bonding of Gd_6MTe_2 (M=Co, Ni), Er_6RuTe_2  

International Nuclear Information System (INIS)

Three new rare earth metal-rich compounds, Gd_6MTe_2 (M=Co, Ni) and Er_6RuTe_2, were synthesized in direct reactions between the R, R_3M, and R_2Te_3 (R=Gd, Er, M=Co, Ni, Ru). These materials all adopt the same Zr_6CoAl_2 structure type with space group P6-bar 2m (No. 189, Z=1). Single crystal structures of Gd_6CoTe_2 and Er_6RuTe_2 were determined and lattice parameters are a=b=8.3799(5), c=3.9801(4) A, and a=b=8.1473(5) A, c=3.9962(4) A, respectively. Gd_6NiTe_2 was characterized by X-ray powder diffraction; lattice parameters are a=b=8.412(2), c=3.9577(9) A. Metal-metal bonding correlations were analyzed using the empirical Pauling bond order concept.

2003-08-25

31

Development of pyro-separation technology based on molten salt electrolysis  

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 ...

2010-10-01

32

#beta#-delayed proton decays near the proton drip line  

International Nuclear Information System (INIS)

In order to improve the measuring efficiency, a 'proton-gamma' coincidence technique in combination with a He-jet tape transport system was proposed and employed to identify the #beta#-delayed proton precursors. The study of #beta#-delayed proton decays near the proton drip line by using the 'proton-gamma' coincidence technique over the last 5 years at the Institute of Modern Physics, Lanzhou, China, was summarized. New #beta#-delayed proton precursors "1"2"1Ce, "1"2"5Nd, "1"2"8Pm, "1"2"9Sm, "1"3"5Gd, "1"3"7Gd, "1"3"9Dy, "1"4"2Ho, and "1"4"9Yb in the rare-earth region along a speculated proton drip line were synthesized and identified for the first time. The #beta#-delayed proton decays of "8"1Zr, "8"5Mo, "8"9Ru, and "9"3Pd in T_z=1/2 series as well as "9"2Rh in T_z=1 series were observed.

2002-04-02

33

Etching characteristics of high-k dielectric HfO2 thin films in inductively coupled fluorocarbon plasmas  

Science.gov (United States)

Inductively coupled fluorocarbon (CF4/Ar and C4F8/Ar) plasmas were used to etch HfO2, which is a promising high-dielectric-constant material for the gate of complementary metal-oxide-semiconductor devices. The etch rates of HfO2 in CF4/Ar plasmas exceeded those in C4F8/Ar plasmas. The tendency for etch rates to become higher in fluorine-rich (high F/C ratio) conditions indicates that HfO2 can be chemically etched by fluorine-containing species. In C4F8/Ar plasmas with a high Ar dilution ratio, the etch rate of HfO2 increased with increasing bias power. The etch rate of Si, however, decreasd with bias power, suggesting that the deposition of carbon-containing species increased with increasing the power and inhibited the etching of Si. The HfO2/Si selectivity monotonically increased with increasing power, then became more than 5 at the highest tested bias power. The carbon-containing ...

2005-11-01

34

The crystal structure of YPdSi, the isotopic compounds LnPdSi (Ln=Gd-Lu), and their structural relation to some other equiatomic compounds of the rare earth and transition metals with main group elements  

International Nuclear Information System (INIS)

The nine title compounds were prepared from the elements by arc-melting and subsequent heat treatment in resistance and high-frequency furnaces. The crystal structure of these isotypic compounds was determined for YPdSi from single-crystal X-ray diffractometer data: Pmmn, a = 430.8(1) pm, b = 1391.2(1) pm, c = 743.1(1) pm, Z = 8, R = 0.024 for 417 structure factors and 40 variable parameters. The crystal structures of the isotypic compounds GdPdSi and ErPdSi were also refined from single-crystal data. The structure is of a new type. It consists of condensed, six-membered rings of alternating palladium and silicon atoms with Pd-Si bond distances varying between 249.6 and 258.8 pm. These two-dimensionally infinite nets are connected to each other via weak Pd-Si and Si-Si bonds with bond distances of 276.3 and 259.5 pm. The rare earth atoms are situated above and below the six-membered palladium-silicon rings in a manner as it is known for the aluminum atoms in the ...

37

Synthesizer Stability Evaluation - NASA Technical Report Server (NTRS)  

Science.gov (United States)

verified via high-resolution spectral density measurements using the Hadamard Variance. .... spectral density measurements were made with the HF5390 ...

38

Selenium and iodine labeled pH shift brain imaging agents  

International Nuclear Information System (INIS)

(Jan - Feb 1981). United Kingdom Kung, HF Tramposch, K. Blau, M. Buffalo

39

Quantum Information Processing Using Local Control of ...  

Science.gov (United States)

... The insu- lation between gate and nanowire is the high-k dielectric HfO2, deposited by atomic layer depo- sition (ALD). ...

2006-12-31

40

The study of 25 MeV alpha particle elastic scattering from a wide range of targets from "4"4Ca to "9"4Zr  

International Nuclear Information System (INIS)

The elastic scattering angular distributions of 25 MeV alpha particles scattered from "7"3Ge, "8"9Y, "9"0Zr, "9"1Zr"9"4Zr, "9"3Nb, "4"4Ca and "4"5Sc have been measured experimentally, and fitted using a conventional optical model. (author).

41

Pore size distribution in ZrO_2-Al_2O_3 composite particles prepared from Zr-Al metallo-organic compounds  

International Nuclear Information System (INIS)

Zr-Al metallo-organic compounds were thermally decomposed to prepare ZrO_2-Al_2O_3 composite powders. The specific surface area was dependent on the organofunctional groups of the starting organic compounds. The pore size distribution was dependent on the heating rate when the heating temperature was the same. 4 refs.; 4 figs.

1989-01-01

42

Pair excitation in "9"0Zr  

International Nuclear Information System (INIS)

... 3 reactions mev range 10-100 neutron spectra neutrons nuclear reaction

43

The effect of ion implantation of Ar on the aqueous corrosion resistance of Zr-4 alloy  

International Nuclear Information System (INIS)

The effect of ion implantation on the aqueous corrosion resistance of Zr-4 in deaerated 1N H_2SO_4 was studied with the potentiokinetic technique. The Zr-4 alloy was bombarded with 5x10"1"4-2x10"1"6 Ar/cm"2 of 190 keV. It was found that the passive current density of Zr-4 decreases with increasing implantation dose. Photoelectrochemical results show that the ion implantation of Ar in Zr-4 raises the flatband potential of its passive film. AES was employed to analyze the surface of the passive film of Zr-4. The decrease in passive current density may be attributed to a thickening oxide layer on Zr-4 and a decrease in concentration of oxygen vacancies in its passive film. ((orig.)).

44

Hydrogen absorption behavior of Zr-2.5Nb pressure tubes in Wolsung Unit 1  

Energy Technology Data Exchange (ETDEWEB)

The deuterium uptake behavior of Zr-2.5Nb pressure tubes in Wolsung Unit 1 was analyzed in terms of longitudinal location, operation time, and coolant temperature. The results were compared with those obtained from Canadian CANDU reactors. The amount of deuterium uptake was higher at the outlet part than at the inlet part and was also higher when subjected to a longer operation time and a higher coolant temperature. The hydrogen uptake of Zr-2.5Nb in a hydrogen gas atmosphere was dependent on the microstructure of the alloy. The aged Zr-2.5Nb consisting of {alpha}-Zr and {beta}-Zr phases. The hydrogen in the alloy decreased the rate of oxidation. This could be explained in terms of the cathodic controlled reaction of Zr-2.5Nb oxidation. (author)

1998-08-01

45

Change from polycrystalline to amorphous growth in sputtered CoZr/Cu multilayers  

International Nuclear Information System (INIS)

The authors present an investigation of structural changes occurring in bilayer stacks with crystalline columnar growth when one of the layers is substituted by layers known to grow amorphous. In Co/Cu multilayers the Co layers were substituted by CoZr layers of varying Zr content and layer thickness. Structural characterization was performed by transmission electron microscopy (TEM). They show that the amorphization of the CoZr layers leading to a destruction of the columnar growth depends both on the Zr content and on the thickness of the CoZr layers. Additionally a change to textured growth with a normal to the substrate occurs with increasing Zr content. They explain their observations by a simple picture based on the hard sphere model.

1997-04-04

46

Sulfidation-resistant alloy/cladding for internal components of coal-conversion equipment. Volume 2. Cladding development. Final report  

Energy Technology Data Exchange (ETDEWEB)

An Fe-19Cr-8Al-0.5Hf alloy has been roll bonded to Alloy 800 to form a protective clad material suitable for use in coal conversion atmospheres. The commercial producibility of both the Fe-19Cr-8Al-0.5Hf alloy and the clad composite has been demonstrated. The clad composite has been shown to exhibit resistance to sulfidation in high sulfur, coal gasification atmospheres low Btu for 2000 hrs at 1800/sup 0/F (1255K). The FeCrAlHf alloy must be preoxidized in the absence of sulfur to form fully protective alumina scales on all surfaces. Useful life of the composite at temperatures of 1400 to 2000/sup 0/F (1033 to 1366K) is governed by reactions at the FeCrAlHf clad alloy 800 interface. The rate of interdiffusion decreases with increasing Ni content and a high Ni alloy such as RA333 appears to be a better substrate than Alloy 800 for a FeCrAlHf composite. The mechanical properties of ...

1981-12-01

47

Hydrogenolysis reactions characteristics of deashed coal under low temperature; Teionka ni okeru dakkai shoritan no suisoka bunkai hanno tokusei  

Energy Technology Data Exchange (ETDEWEB)

In relation to coal liquefaction, the effect of inorganic minerals on liquefaction reactivity and the effect of hydrofluoric acid (HF) treatment on organic molecular structure of coals were studied by demineralization of low-rank coals in HCl or HF solution. In experiment, Taiheiyo coal specimen was deashed in HCl solution at 25-70{degree}C for 6 hours while agitating, and in addition, deashed in HF solution. Hydrogenolysis of the deashed coal specimen was conducted using tetralin or methylnaphthalene as solvent under initial hydrogen pressure of 1.96MPa at reaction temperature of 693K for 60min. The experimental results are as follows. The ash content of Taiheiyo coal hardly offers catalysis in hydrogenolysis reaction. Carboxyl group increases in demineralization of coal because of breakage of bridged bonds. Organic structure of coal changes by demineralization in dense HF solution. Change in organic ...

1996-10-28

48

Hybrid Density Functional Studies of ?-Pu  

Science.gov (United States)

Hybrid density functionals, which replaces a fraction of a density functional theory exchange with exact Hartree-Fock (HF) exchange, have been used to study the structural, magnetic, and electronic properties of ?-Pu. The fractions of exact Hartree-Fock exchange used were 25%, 40%, and 55%. Compared to the pure PBE functional, the lattice constants expanded with respect to the experimental value when the PBE-HF hybrid functionals were applied. For pure PBE and hybrids functionals with HF exchange amounts of 25% and 40%, the ground state structure was anti-ferromagnetic, while for 55% HF contribution the ground state was non-magnetic. The 5f electrons tend to exhibit slight delocalization or itinerancy for the pure PBE functional and well-defined localization for the hybrid functionals, with the degree of 5f electron localization increasing with the amount of HF exchange. Overall, ...

2009-03-01

49

Does hybrid density functional theory predict a non-magnetic ground state for ?-Pu?  

Science.gov (United States)

Hybrid density functionals, which replace a fraction of density functional theory (DFT) exchange with exact Hartree-Fock (HF) exchange, have been used to study the structural, magnetic, and electronic properties of ?-Pu. The fractions of exact Hartree-Fock exchange used were 25%, 40%, and 55%. Compared to the pure PBE functional, the lattice constants expanded with respect to the experimental value when the PBE-HF hybrid functionals were applied. For pure PBE and hybrid functionals with HF exchanges amounts of 25% and 40%, the ground state structure was anti-ferromagnetic, while for 55% HF contribution the ground state was non-magnetic. The 5f electrons tend to exhibit slight delocalization or itinerancy for the pure PBE functional and well-defined localization for the hybrid functionals, with the degree of 5f electron localization increasing with the amount of HF exchange. Overall, ...

2009-01-01

50

Does hybrid density functional theory predict a non-magnetic ground state for #delta#-Pu?  

International Nuclear Information System (INIS)

Hybrid density functionals, which replace a fraction of density functional theory (DFT) exchange with exact Hartree-Fock (HF) exchange, have been used to study the structural, magnetic, and electronic properties of #delta#-Pu. The fraction of exact Hartree-Fock exchange used were 25%, 40%, and 55%. Compared to the pure PBE functional, the lattice constants expanded with respect to the experimental value when the PBE-HF hybrid functionals were applied. For pure PBE and hybrid functionals with HF exchanges amounts of 25% and 40%, the ground state structure was anti-ferromagnetic, while for 55% HF contribution the ground state was non-magnetic. The 5f electrons tend to exhibit slight delocalization of itinerancy for the pure PBE functional and well-defined localization for the hybrid functionals, with the degree of 5f electron localization increasing with the amount of HF exchange. ...

2009-01-01

51

Electrochemical roles of precipitates on uniform corrosion and hydrogen pickup of zirconium alloys, 2. Roles on hydrogen pickup  

Energy Technology Data Exchange (ETDEWEB)

Substantial roles of precipitates such as Zr-Fe-Cr type intermetallic compounds on uniform corrosion and hydrogen pickup of zirconium alloys in pure water autoclave tests were investigated from an electrochemical point of view. In the previous paper, corrosion mechanism was elucidated by the anodic protection-precipitates degradation model. This paper describes the roles on hydrogen pickup. 633 K pure water autoclave test was performed on high purity zirconium, Zr-0.2Fe, Zr-0.2Cr, and Zr-0.1Fe-0.1Cr alloys. Hydrogen analysis after the corrosion test showed that hydrogen pickup ratio of Zr-0.2Fe alloy was about 80%. It was much higher than about 30% of pure Zr and about 10% of both Zr-0.2Cr and Zr-0.1Fe-0.1Cr alloys. Larger hydrogen content was introduced into Zr-0.2Fe alloy than the other ones by the ...

2000-08-01

52

Electrochemical roles of precipitates on uniform corrosion and hydrogen pickup of zirconium alloys, 2. Roles on hydrogen pickup  

International Nuclear Information System (INIS)

Substantial roles of precipitates such as Zr-Fe-Cr type intermetallic compounds on uniform corrosion and hydrogen pickup of zirconium alloys in pure water autoclave tests were investigated from an electrochemical point of view. In the previous paper, corrosion mechanism was elucidated by the anodic protection-precipitates degradation model. This paper describes the roles on hydrogen pickup. 633 K pure water autoclave test was performed on high purity zirconium, Zr-0.2Fe, Zr-0.2Cr, and Zr-0.1Fe-0.1Cr alloys. Hydrogen analysis after the corrosion test showed that hydrogen pickup ratio of Zr-0.2Fe alloy was about 80%. It was much higher than about 30% of pure Zr and about 10% of both Zr-0.2Cr and Zr-0.1Fe-0.1Cr alloys. Larger hydrogen content was introduced into Zr-0.2Fe alloy than the other ones by the ...

2000-08-01

53

Effects of sintering atmospheres and addition of ZrO_2 on mechanical properties of #alpha#-Sialon ceramics(x=0.15)  

International Nuclear Information System (INIS)

4.82 wt% AIN and 2.98 wt% Y_2O_3 were added to Si_3N_4 as sintering agents in order to have #alpha#_Sialon composition of x=0.15 and monoclinic ZrO_2 between 0 to 10 wt% was admixed with Si_3N_4 based ceramics were fabricated by hot-pressing at 1,750 deg C for 90 min under 30 MPa in argon and nitrogen atmospheres effects of sintering atmospheres and addition of ZrO_2 on mechanical properties of Si_3N_4 based ceramics were investigated. As ZrO_2 content increased, the fraction of #alpha#-Sialon tended to decrease and the amount of cubic ZrO_2 increased because Y_2O_3 acted as the stabilizer of ZrO_2. The sintering atmospheres didn't affect on the sintering behavior and the product phases in hot-pressing of Si_3N_4. Bending strength increased when ZrO_2 content. ZrO_2 didn't contribute to the increase of fracture toughness because stabilized ...

54

Giant Lipoma of Posterior Neck with Bleeding Decubitus Ulcer: A Rare Entity  

UK PubMed Central (United Kingdom)

Giant lipomas are benign soft tissue tumours. They are found relatively rarely on the posterior part of the neck. Bleeding pressure ulcer in this giant tumour is a rare presentation. Surgical interventions...Full Text Available

2010-05-01

55

Plane-wave-basis pseudopotential calculations of the surface relaxations of Ti(0001) and Zr(0001)  

International Nuclear Information System (INIS)

The relaxations of the Ti(0001) and Zr(0001) surfaces are studied using the plane-wave-basis pseudopotential method within the local-density approximation. We find that the first interlayer spacings of Ti(0001) and Zr(0001) are contracted with respect to the bulk spacings by 6.8% and 6.1%, respectively. Such large relaxations for the close-packed surfaces of Ti and Zr are in good agreement with recent linear-augmented-plane-wave calculations. In addition, we predict a weak vibrational effect on the surface relaxation of Zr(0001) by considering the free energy in the quasiharmonic approximation. This result can be attributed to a very strong bonding between the first- and second-layer Zr atoms as a consequence of the bond-order endash bond-length correlation. copyright 1997 The American Physical Society.

56

Rare Earth Doped Yttrium Aluminum Garnet (YAG ... - GLTRS - NASA  

Science.gov (United States)

films and cylinders of rare earth doped yttrium aluminum garnets. ... We knew that yttrium aluminum garnet (YAG) could be doped with ...

57

Nonchylous idiopathic pleural effusion in the newborn  

UK PubMed Central (United Kingdom)

Congenital isolated pleural effusion is a rare cause of respiratory distress in neonates. It is usually chylous. Herein, we report a rare case of nonchylous congenital idiopathic pleural effusion.

2011-01-01

58

Competing Shapes And Alignments In Neutron-Rich Hf Nuclei  

International Nuclear Information System (INIS)

The talk will focus on spin-dependent competition between oblate and prolate shape minima in the potential energy landscape of "1"8"0Hf (the most neutron-rich stable isotope), mediated via the alignment of valence nucleons. Results of a prompt spectroscopic study, using deep inelastic reactions with Gammasphere and CHICO, bombarding a thin "2"3"2Th target with a "1"8"0Hf beam #approx#25% above the Coulomb barrier, will be presented. Nucleon alignments in both prolate and oblate minima will be discussed, as well as the favoring of oblate collective rotation at high spins, observed through a mixing with gamma vibrations built on the prolate shape.

2008-05-12

59

Excitations and electromagnetic transitions for /sup 88/Sr and /sup 90/Zr  

Energy Technology Data Exchange (ETDEWEB)

In this letter we report the outcome for the microscopic approach for the semi-magic nuclei /sup 88/Sr and /sup 90/Zr. For comparison, we have also treated the semi-phenomenological version for the Migdal and SDI force.

1981-10-10

60

Excitations and electromagnetic transitions for /sup 88/Sr and /sup 90/Zr  

Energy Technology Data Exchange (ETDEWEB)

An application of the renormalized random phase approximation to nuclear structure is presented for the semi-magic nuclei /sup 88/Sr and /sup 90/Zr. It is reported the outcome for the microscopic approach in comparison with the semiphenomenological version for the particle-hole forces.

1981-10-10

61

Electrochemical behavior of zirconium in the LiCl-KCl molten salt at Mo electrode  

British Library Electronic Table of Contents (United Kingdom)

The electroreduction process of Zr(IV) was studied at molybdenum electrode in LiCl-KCl-K2ZrF6 molten salt. The transient electrochemical techniques, such as cyclic voltammetry and chronopotenimetry were used. The experimental results showed that the electrochemical reduction of Zr(II)/Zr and Zr(IV)/Zr(II) were both diffusion-controlled process. In the 773-973K range, the diffusion coefficients of Zr(ii) and Zr(IV) were determined: DZr(II)=0.15567exp{-69.65x10^3RT(K)}cm^2/s, DZr(IV)=1.09x10^-^4exp{-44.39x10^3RT(K)}cm^2/s. The activation energy values for the diffusion process were 69.65kJ/mol and 44.39kJ/mol, respectively.

2011-01-01

62
63

#beta#-delayed proton decays of "8"1Zr and "8"5Mo  

International Nuclear Information System (INIS)

... RADIATION PHYSICS beta decay delayed protons excited states experimental

64

The effect of oxygen in Ru gate electrode on effective work function of Ru/HfO2 stack structure  

British Library Electronic Table of Contents (United Kingdom)

Effective work function (m,eff) values of Ru gate electrode on SiO2 and HfO2 MOS capacitors were carefully examined and discussed from the viewpoint of an effect of oxygen incorporation in Ru gate electrode on m,eff. Annealing at 400degreeC in the reduction (3%H2) and the oxidation (1%O2) ambient resulted in similar changes in the m,eff of Ru/HfO2/SiO2 and Ru/SiO2 MOS capacitors. Furthermore, the Ru gate MOS capacitor after annealing in the oxidation condition have shown almost the same m,eff value to that of RuO2 gate MOS capacitors. The oxygen concentration in the Ru/HfO2 interface after annealing in oxidizing atmosphere is approximately one order of magnitude higher than that after annealing in reducing atmosphere as confirmed by secondary ion mass spectroscopy analysis. Furthermore, th...

2006-01-01

65

The causes, consequences, and treatment of left or right heart failure  

UK PubMed Central (United Kingdom)

Chronic heart failure (HF) is a cardiovascular disease of cardinal importance because of several factors: a) an increasing occurrence due to the aging of the population, primary and secondary prevention...Full Text Available

2011-01-01

66

Test design description; Volume 1B: Part 1, Fuel pins for the FSP-1R FFTF test assembly (HF191A): Revision 1  

Energy Technology Data Exchange (ETDEWEB)

The addition of rhenium clad pins to the FSP-1R test matrix is shown in this revision. Also attached are other updates to the TDD-IB, Part 1.

1989-12-20

67

Solubilization of lignite and behavior of oxygen containing functional groups in coal with superacid; Chokyosan wo mochiita kattan no kayoka oyobi sanso kannoki no kyodo  

Energy Technology Data Exchange (ETDEWEB)

Solubilization of lignite including a large amount of oxygen containing functional groups was attempted using HF/BF3, and the behavior of oxygen containing functional group, one of the important factors for coal liquefaction, was studied. In experiment, the cooled slurry of Yallourn coal specimen and solvent (toluene, isopentane) was filled into a vacuum autoclave together with HF/BF3. Reaction was performed under spontaneous pressure at 50, 100 or 150{degree}C for 3 hours. The distribution of oxygen containing functional groups in each coal specimen was determined by quantification of carboxyl group, hydroxyl group and carbonyl group. As the experimental result, the superacid mixture of HF and BF3 considerably improved the solubility of coal specimens into solvent as compared with individual HF and BF3. The solubility was 68wt% into benzene, 96% into THF and 99% (nearly 100%) into pyridine. It was ...

1996-10-28

68

Revision number 2 to test design description Volume IB, Part 2 (WHC-SP-0214) FSP-1R FFTF test assembly (HF191A)  

Energy Technology Data Exchange (ETDEWEB)

Based on changes to the fuel pin gas gap composition, pin location and assembly location, revisions to the TDD-IB, Part 2 are provided.

1989-07-14

69

Layered Functional Network Analysis of Gene Expression in Human Heart Failure  

UK PubMed Central (United Kingdom)

BackgroundAlthough dilated cardiomyopathy (DCM) is a leading cause of heart failure (HF), the mechanism underlying DCM is not well understood. Previously, it has been demonstrated...Full Text Available

70

Anxiety in Patients with Cardiac Disease.  

Science.gov (United States)

Anxiety may cause adverse outcomes through physiologic pathways in patients with cardiac disease. The purpose of this dissertation was to investigate anxiety and its correlates in persons with acute myocardial infarction (AMI) and heart failure (HF). The ...

2005-01-01

71

Microstructural analysis of as-processed U-10 wt.%Mo monolithic fuel plate in AA6061 matrix with Zr diffusion barrier  

International Nuclear Information System (INIS)

For higher U-loading in low-enriched U-10 wt.%Mo fuels, monolithic fuel plate clad in AA6061 is being developed as a part of Reduced Enrichment for Research and Test Reactor (RERTR) program. This paper reports the first characterization results from a monolithic U-10 wt.%Mo fuel plate with a Zr diffusion barrier that was fabricated as part of a plate fabrication campaign for irradiation testing in the Advanced Test Reactor (ATR). Both scanning and transmission electron microscopy (SEM and TEM) were employed for analysis. At the interface between the Zr barrier and U-10 wt.%Mo, going from Zr to U(Mo), UZr_2, #gamma#-UZr, Zr solid-solution and Mo_2Zr phases were observed. The interface between AA6061 cladding and Zr barrier plate consisted of four layers, going from Al to Zr, (Al, Si)_2Zr, (Al, Si)Zr_3 ...

2010-07-01

72

The identical bands in [sup 177]Ta  

Energy Technology Data Exchange (ETDEWEB)

The 4025/2 bands in [sup 177]Ta which are ''identical'' to the neighboring even-even [sup 176]Hf groundstate band have been extended to higher angular momentum. These bands in the two nuclei are seen to diverge from each other in the region of the first i[sub 13/2] neutron alignment. The lower observed crossing frequency for the 4025/2 bands indicates a lower deformation for these bands compared to [sup 176]Hf. Extensions to the h[sub 9/2] 5411/2 yrast band are also reported. (orig.)

1993-10-01

73

The identical bands in "1"7"7Ta  

International Nuclear Information System (INIS)

The [402]5/2 bands in "1"7"7Ta which are ''identical'' to the neighboring even-even "1"7"6Hf groundstate band have been extended to higher angular momentum. These bands in the two nuclei are seen to diverge from each other in the region of the first i_1_3_/_2 neutron alignment. The lower observed crossing frequency for the [402]5/2 bands indicates a lower deformation for these bands compared to "1"7"6Hf. Extensions to the h_9_/_2 [541]1/2 yrast band are also reported. (orig.).

74

Inelastic electron--dipole-molecule scattering at sub-milli-electron-volt energies: HF and NH_3  

International Nuclear Information System (INIS)

Studies of destruction of very-high-n (100HF and NH_3 are reported. Analysis of the data using the essentially-free-electron model suggests that, for ultralow electron energies (#approx#80 #mu#eV--1.4 meV), the cross section #sigma#(var-epsilon) for rotationally inelastic scattering of electrons by a polar target varies approximately as 1/var-epsilon, where var-epsilon is the electron energy.

76

Formation of double hafnium sulfates in the systems HfO"2-H"2SO"4-Me"2SO"4-H"2O (Me-Na, K, Rb, Cs and NH"4)  

International Nuclear Information System (INIS)

Influence of alkali elements on formation, composition, solubility and region of stability of complex hafnium sulfates, separated in the HfO"2-H"2SO"4-Me"2SO"4-H"2O (Me-Na, K, Rb, Cs and NH"4 group) systems is studied. In all cases hafnium forms the complex sulfates of three types differing by basicity or ratio HfO"2:SO"3 1:1, 1:1.5, 1:2. Three basic and three medium sulfates are crystallized in the systems with sodium; with rubidium, cesium and ammonium - two basic and two medium sulfates and with potassium - two basic and one medium salts. Anhydrous salts do not form in the investigated systems. Potassium salt approximately 0.3% according to HfO"2 is characterized by minimum solubility from the salts of 2HfOSO"4x(1-3)Me"2SO"4x(4-6)xH"2O while solubility of the same salts with rubidium, cesium and sodium increases from (0.25-1.0); (0.5-1.5) till (1.0-5)% according to HfO"2 ...

1982-01-01

77

Fabrication of Dense -SiAlON Ceramics with ZrO2 Additions Via a Rapid Reaction-Bonding and Postsintering Route  

British Library Electronic Table of Contents (United Kingdom)

Rapid nitridation was used to fabricate reaction-bonded and postsintered -Si6-ZAlZOZN8-Z (Z=1) ceramics with monoclinic ZrO2 added to the starting powder. Thermo-gravimetric analysis revealed that the addition of ZrO2 reduced the starting temperature of the main nitridation reaction. Using a reaction-bonding route with heating rates of 5, 10, and 20C/min, to fabricate -SiAlON ceramics without ZrO2 resulted in unreacted silicon that bled out of the specimens and the Z=1 composition samples did not maintain the original green compact morphology. On the other hand, no such bleeding of melted silicon was observed for samples with ZrO2 additions and the samples following nitridation maintained the original green morphology. The microstructure and mechanical properties of samples produced by rap...

2011-01-01

78

Constitutional examinations in the system Fe-Al-Zr; Konstitutionsuntersuchungen im System Fe-Al-Zr  

Energy Technology Data Exchange (ETDEWEB)

Two isothermal sections were prepared at 1000 and 1150 C showing the low-Zr phases of the system Fe-Al-Zr. The phase equilibria were determined by means of X-ray powder diffractometry and electron beam microanalysis. For initial characterisation of mechanical properties, hardness values are determined and added to the tabulated data. (orig./MM) [German] Es werden am Fe-Al-Zr-System zwei isotherme Schnitte durch den zirkoniumarmen Teil des Systems bei 1000 und 1150 C erstellt. Die auftretenden Phasengleichgewichte werden mit Hilfe der Roentgenpulverdiffraktometrie und Elektronenstrahlmikroanalyse aufgeklaert. Zusaetzlich werden zur ersten Charakterisierung der mechanischen Eigenschaften Haertewerte bestimmt.

1999-07-01

79

Radiochemical detector cross section sensitivity studies in the A approx. = 90 mass region  

Energy Technology Data Exchange (ETDEWEB)

The use of radiochemical detectors in the A approx. = 90 mass region to measure 14 MeV neutron fluences is investigated from the standpoint of cross section sensitivities. Specifically, /sup 90/Zr and /sup 89/Y neutron-induced cascades leading to the production of /sup 89/Zr, /sup 88/Zr, /sup 88/Y, and /sup 87/Y are studied in a one-energy-group approximation, and the sensitivities of the measured ratios R/sub Z/ = /sup 88/Zr//sup 89/Zr and R/sub Y/ = /sup 87/Y//sup 88/Y to the input cross sections are delineated. The most sensitive cross section in each cascade is the cross section that dominates the production of the final isotope in the chain. Only one of the isomeric levels in /sup 90/Zr contributes importantly to the Zr cascade. Burnback (n,..gamma..) and burnup (n,p) reactions are also considered. The (n,..gamma..) effects are small, ...

1984-04-05

80

Solid-state amorphization reaction in mechanically deformed Al_xHf_1_0_0_-_x multilayered composite powders and the effect of annealing  

International Nuclear Information System (INIS)

Single phase amorphous Al_xHf_1_0_0_-_x alloys with a wide amorphization range (33#<=#x#<=#75) were synthesized by the solid-state interdiffusion of pure polycrystalline Al and Hf powders at room temperature using a rod-milling technique. The mechanisms of metallic glass formation and competing crystallization processes in the mechanically deformed composite powders were investigated by means of X-ray diffraction, differential thermal analysis, scanning electron microscopy and transmission electron microscopy. The numerous intimate layered composite particles of the diffusion couples that formed during the first and intermediate stages of milling (0-173 ks) are intermixed to form amorphous phase(s) upon heating to about 980 K by so-called thermally assisted solid-state amorphization (TASSA). The amorphization heat formation for the binary Al_xHf_1_0_0_-_x system via TASSA, #DELTA#H"T"A"S"S"A_a, was measured directly ...

1999-03-04

81

Electrochemical roles of precipitates on uniform corrosion and hydrogen pickup of zirconium alloys, 1. Roles on corrosion  

Energy Technology Data Exchange (ETDEWEB)

Substantial roles of precipitates such as Zr-Fe-Cr type intermetallic compounds on uniform corrosion and hydrogen pickup of zirconium alloys in pure water autoclave tests were investigated from an electrochemical point of view. This paper describes the roles on corrosion. A corrosion test on precipitate-containing and precipitate-free materials made from pure zirconium and a small quantity of iron and chromium, rest potential measurements on an intermetallic compound of Zr(FeCr){sub 2} and zirconium matrix, and a galvanic coupling test of those were performed. Results showed that corrosion behavior of zirconium alloys could be attributed to the electrochemical properties of intermetallic compounds precipitated in each alloy. Namely, the cathodic and anodic polarization characteristics were associated with anodic protection provided by the precipitates on the alloys and the precipitates degradation in the oxide films, respectively. The mechanism ...

2000-07-01

82

Electrochemical roles of precipitates on uniform corrosion and hydrogen pickup of zirconium alloys, 1. Roles on corrosion  

International Nuclear Information System (INIS)

Substantial roles of precipitates such as Zr-Fe-Cr type intermetallic compounds on uniform corrosion and hydrogen pickup of zirconium alloys in pure water autoclave tests were investigated from an electrochemical point of view. This paper describes the roles on corrosion. A corrosion test on precipitate-containing and precipitate-free materials made from pure zirconium and a small quantity of iron and chromium, rest potential measurements on an intermetallic compound of Zr(FeCr)_2 and zirconium matrix, and a galvanic coupling test of those were performed. Results showed that corrosion behavior of zirconium alloys could be attributed to the electrochemical properties of intermetallic compounds precipitated in each alloy. Namely, the cathodic and anodic polarization characteristics were associated with anodic protection provided by the precipitates on the alloys and the precipitates degradation in the oxide films, respectively. The mechanism was ...

2000-07-01

83

Direct observation of radial distribution change during tensile deformation of metallic glass by high energy X-ray diffraction method  

International Nuclear Information System (INIS)

The purpose of this research is to investigate the micro-mechanism of deformation behavior of metallic glasses. We report the results of direct observations of short-range and medium-range structural change during tensile deformation of metallic glasses by high energy X-ray diffraction method. Cu50Zr50 and Ni30Zr70 metallic glass samples in the ribbon shape (1.5 mm width and 25 ?m) were made by using rapid quenching method. Tensile deformation added to the sample was made by using special equipment adopted for measuring the high energy X-ray diffraction. The peaks in pair distribution function g(r) for Cu50Zr50 and N30iZr70 metallic glasses move zigzag into front and into rear during tensile deformation. These results of direct observation on atomic distribution change for Cu50Zr50 and Ni30Zr70 metallic glass ribbons during tensile deformation suggest that the ...

2009-08-26

84

Reaction of hydrogen with ZrNiHsub(x) studying by programmed thermodesorption method  

International Nuclear Information System (INIS)

The method of programmed thermodesorption has been used to study the forms of hydrogen adsorption in ZrNiHsub(x) hydride. It is shown that high concentration of the hydrogen, which extracted from hydride in the temperature range of 240-260 deg C results in appearance of ''reverse'' peak. Charge of hydride adsorption properties during its oxidation-reduction treatment is studied. Comparison with spectra of hydrogen thermodesorption from the surface of Ni/ZrO_2 deposited catalyst and zirconium oxide is carried out.

1983-01-01

85

Half-lives of the T{sub z}=1/2 series nuclei, {sup 81}Zr and {sup 85}Mo  

Energy Technology Data Exchange (ETDEWEB)

The nuclei {sup 81}Zr and {sup 85}Mo with T{sub z}=1/2 have been reinvestigated via their {beta}-delayed proton emissions with p-{gamma} coincidence measurement. The half-life of {sup 81}Zr has been measured to be 5.3{+-}0.5 s, which agrees with one of the two previous values. For {sup 85}Mo, the measured half-life is 3.2{+-}0.2 s, which revises the previous value. (orig.) With 3 figs., 12 refs.

1997-12-01

86

Half-lives of the T_z=1/2 series nuclei, "8"1Zr and "8"5Mo  

International Nuclear Information System (INIS)

The nuclei "8"1Zr and "8"5Mo with T_z=1/2 have been reinvestigated via their #beta#-delayed proton emissions with p-#gamma# coincidence measurement. The half-life of "8"1Zr has been measured to be 5.3#+-#0.5 s, which agrees with one of the two previous values. For "8"5Mo, the measured half-life is 3.2#+-#0.2 s, which revises the previous value. (orig.).

87

Activation method for determination of Pb, La, Zr and Ti macrocomponents in lead-lanthanum zirconate-titanate materials on a neutron generator  

International Nuclear Information System (INIS)

Instrumental neutron activation analysis is used for simultaneously determination of macrocomponents in ferroelectric materials LLZT. Pb, Zr, Ti have been determined by "2"0"3Pb, "8"9Zr and "4"8Sc nuclides created by fast neutron (14.5 MeV) activation. Application of paraffine as neutron moderator and reflector allows to simultaneously determine lanthanum by "1"4"0La nuclide. It has been shown that zirconium, titanium and lanthanum can be determined with the accuracy of #+-#0.1 mas. % and lead - #+-#0.7 mas. %.

88

Physical and optical properties of rare earth cobalt magnets  

Energy Technology Data Exchange (ETDEWEB)

Rare Earth Cobalt (REC) permanent magnets have unique properties that permit solutions to some optical tasks that cannot be accomplished with conventional magnets. A review of design and of performance characteristics of these magnets includes an analytical description of the three dimensional fringe fields of REC quadrupoles.

1980-08-01

89

Metabolic Engineering of Lactobacillus plantarum for Production of l-Ribulose?  

UK PubMed Central (United Kingdom)

l-Ribulose is a rare and expensive sugar that can be used as a precursor for the production of other rare sugars of high market value such as l-ribose. In this work we describe a production...Full Text Available

2007-11-01

90

Giant vesical diverticulum: A rare cause of defecation disturbance  

UK PubMed Central (United Kingdom)

Vesical diverticula frequently result from bladder outlet obstructions. However, giant vesical diverticula which cause acute abdomen or intestinal obstruction are very rare. Our review of the English...Full Text Available

2009-08-21

91

Genetic Diversity Assessment of Rarely Cultivated Traditional Indica Rice (Oryza sativa L.) Varieties  

UK PubMed Central (United Kingdom)

Random amplified polymorphic DNA fingerprinting was performed to assess the genetic diversity among rarely cultivated traditional indica rice (Oryza sativa ...Full Text Available

92

Cecal Schwannoma: A Rare Cause of Gastrointestinal Bleeding in a Young Woman with Review of Literature  

UK PubMed Central (United Kingdom)

Schwannomas are rare mesenchymal tumors of the gastrointestinal tract. Occurrence of these tumors is more common in the stomach than in the large intestine. These tumors usually present as polypoidal...Full Text Available

2011-01-01

93

Case Reports: Fractures of Threaded Cups: Rare Complications of a Well-established Implant  

UK PubMed Central (United Kingdom)

The use of cementless threaded cups in THA is a well-established treatment. Fractures of the cups are rare complications recorded in individual cases with material defects being discussed as the primary...Full Text Available

2009-03-01

94

A rare case of neuroleptic malignant syndrome presenting with serious hyperthermia treated with a non-invasive cooling device: a case report  

UK PubMed Central (United Kingdom)

IntroductionA rare side effect of antipsychotic medication is neuroleptic malignant syndrome, mainly characterized by hyperthermia, altered mental state, haemodynamic dysregulation,...Full Text Available

95

A rare case of intracranial metastatic amelanotic melanoma with cyst  

UK PubMed Central (United Kingdom)

A rare case of intracranial metastatic amelanotic melanoma with cyst is presented. The patient was a 51 year old woman with a malignant melanoma arising on her right chest. Two years after a wide excision,...Full Text Available

2003-07-01

96

A Rare Case of Fatal Haemorrhage After Tracheostomy  

UK PubMed Central (United Kingdom)

Tracheo-arterial fistula after tracheostomy causing massive haemorrhage is fortunately rare, but can be serious and often fatal. Brachiocephalic trunk is commonly at risk of erosion because of its close...Full Text Available

2007-11-01

97

Shape isomers: Mean-field description and beyond  

Energy Technology Data Exchange (ETDEWEB)

Nuclear Hartree-Fock (HF) + BCS calculations have led to predictions of shape isomerism in isotopes of Pt, Hg and Os nuclei. These have been confirmed through the observation of superdeformed rotational bands in {sup 190,{hor ellipsis},194}Hg. Encouraged by these measurements and similar observations in {sup 194}Pb, we have extended these calculations to a wide range of contiguous nuclei. These HF results, for {sup 192,194}Pt, {sup 190,{hor ellipsis},198}Hg and {sup 194}Pb, have been employed in a Generator Coordinate Method (GCM) calculation utilizing the quadrupole deformation as the generating variable. The resulting spectra confirm the conclusions drawn from the HF results and agree with those experiments which have been performed. Adding a phenomenological assumption for the moments of inertia of our GCM states, we can construct the radiative transitions within and out of the superdeformed band. The results are in good ...

1990-11-19

98

Non-thermal atmospheric pressure HF plasma source: generation of nitric oxide and ozone for bio-medical applications  

International Nuclear Information System (INIS)

A new miniature high-frequency (HF) plasma source intended for bio-medical applications is studied using nitrogen/oxygen mixture at atmospheric pressure. This plasma source can be used as an element of a plasma source array for applications in dermatology and surgery. Nitric oxide and ozone which are produced in this plasma source are well-known agents for proliferation of the cells, inhalation therapy for newborn infants, disinfection of wounds and blood ozonation. Using optical emission spectroscopy, microphotography and numerical simulation, the gas temperature in the active plasma region and plasma parameters (electron density and electron distribution function) are determined for varied nitrogen/oxygen flows. The influence of the gas flows on the plasma conditions is studied. Ozone and nitric oxide concentrations in the effluent of the plasma source are measured using absorption spectroscopy and electro-chemical NO-detector at variable gas flows. Correlations ...

2010-01-01

99

The r-process in the early Galaxy  

CERN Document Server

We report Sr, Pd and Ag abundances for a sample of metal-poor field giants and analyze a larger sample of Y, Zr, and Ba abundances. The [Y/Zr] and [Pd/Ag] abundance ratios are similar to those measured for the r-process-rich stars CS 22892-052 and CS 31082-001. The [Pd/Ag] ratio is larger than predicted from the solar-system r-process abundances. The constant[Y/Zr] and [Sr/Y] values in the field stars places strong limits on the contributions of the weak s-process and the main s-process to the light neutron-capture elements. Stars in the globular cluster M 15 possess lower [Y/Zr] values than the field stars. There is a large dispersion in [Y/Ba]. Because the r-process is responsible for the production of the heavy elements in the early Galaxy, these dispersions require varying light-to-heavy ratios in r-process yields.

2002-01-01

100

Structure and Mechanical Properties of Boron-Doped Cubic ...  

Science.gov (United States)

... by the boron doping in most of the alloys except for Al66Mn9Zr25 + 50 ppm B alloy; permanent deformation at ultimate compressive strength is not ...

102

Self-consistent full-potential linearized-augmented-plane-wave local-density electronic-structure studies of magnetism and superconductivity in C15 compounds: ZrZn_2 and ZrV_2  

International Nuclear Information System (INIS)

The electronic structure and properties of the cubic Laves phase (C15) compounds ZrZn_2 and ZrV_2 have been determined using our all-electron full-potential linearized-augmented-plane-wave (FLAPW) method for bulk solids. The computations were performed in two stages: (i) self-consistent warped muffin tin and (ii) self-consistent full potential. Spin-orbit coupling was included after either stage. The effects of the inclusion of the nonspherical terms inside the muffin tins on the eigenvalues is found to be small (of order 1 mRy). However, due to the fact that some of the bands near the Fermi level are flat, this effect leads to a much higher value of the density of states at E/sub F/ in ZnZr_2. The most important difference between the materials ZrZn_2 and ZrV_2 is the position of the d bands derived from the Zr and V atoms. Consequently, these materials have ...

103

Self-consistent full-potential linearized-augmented-plane-wave local-density electronic-structure studies of magnetism and superconductivity in C15 compounds: ZrZn/sub 2/ and ZrV/sub 2/  

Energy Technology Data Exchange (ETDEWEB)

The electronic structure and properties of the cubic Laves phase (C15) compounds ZrZn/sub 2/ and ZrV/sub 2/ have been determined using our all-electron full-potential linearized-augmented-plane-wave (FLAPW) method for bulk solids. The computations were performed in two stages: (i) self-consistent warped muffin tin and (ii) self-consistent full potential. Spin-orbit coupling was included after either stage. The effects of the inclusion of the nonspherical terms inside the muffin tins on the eigenvalues is found to be small (of order 1 mRy). However, due to the fact that some of the bands near the Fermi level are flat, this effect leads to a much higher value of the density of states at E/sub F/ in ZnZr/sub 2/. The most important difference between the materials ZrZn/sub 2/ and ZrV/sub 2/ is the position of the d bands derived from the Zr and V atoms. ...

1988-03-01

104

Neutron time-of-flight spectroscopy and the reaction "8"8Sr("3He,n)"9"0Zr  

International Nuclear Information System (INIS)

... states helium 3 reactions ion sources mev range 10-100 neutron spectrometers

105

Microstructural characterization of ZrO_2/O'-SiAlON composites  

International Nuclear Information System (INIS)

Zirconia has demonstrated a very moderate toughening effect in nitrogen-based ceramic composites because the reaction between tetragonal zirconia (t-ZrO_2) and nitrogen results in additional zirconia stabilization to a nontransformable t' or cubic structure. In O'-SiAlON matrices, the oxygen concentration increases and the oxygen-rich intergranular glassy phase prevents zirconia from nitridation. As a result, tetragonal ZrO_2 is maintained and is transformable in the O'-SiAlON materials. The present study has provided transmission electron microscopy (TEM) evidence of the zirconia transformation and the associated toughening effect in a ZrO_2/O'-SiAlON composite. The implications and limitations of the transformation on toughening of the material are discussed.

106

Mechanical properties of Cu-Ni-Be system alloys  

International Nuclear Information System (INIS)

The effects of addition of 0.17wt%Zr, 0.1wt%Mg and 0.1wt%Co on the mechanical properties of a Cu-1.2wt%Ni-0.2wt%Be alloy have been investigated. Adding Zr, Co or Mg to the Cu-Ni-Be alloy brings about the improvement in strength and stress relaxation property. The Zr, Co or Mg addition decreases the inter-precipitate spacing of #gamma#'' precipitates, resulting in the increase in strength. The higher resistance to the stress relaxation of the Zr- or Co-added alloy is attributed to the lower density of mobile dislocations. The improvement of stress relaxation property by the Mg addition is explained by the viscous glide motion of dislocations dragging Mg atoms, in addition to the lower density of mobile dislocations.

2010-07-01

107

Isobaric analogue resonances in (e,e'p) on "9"0Zr, "8"9Y and "8"8Sr  

International Nuclear Information System (INIS)

... minutes living radioisotopes nuclear reactions nuclei nucleons odd-odd nuclei

110

Disordered bcc γ-phase to δ-phase transformation in Zr-rich U-Zr alloy  

British Library Electronic Table of Contents (United Kingdom)

The transformation mechanism of hexagonal delta phase from the disordered bcc gamma phase has not been reported before in the Zr-rich U-Zr alloy system. With the help of X-ray diffraction, transmission electron microscopy (TEM) and high-resolution TEM analyses it was shown that the gamma to delta conversion takes place by the lattice collapse mechanism of omega transformation. It was also ascertained that a higher aging temperature or time promotes the growth of all four variants of the delta phase within a parent gamma grain. In addition, ab initio electronic structure calculations showed that the bcc to hexagonal transformation, involving partial ordering of the parent bcc phase followed by (111) plane collapse, is energetically favorable.

2011-01-01

111

Concentration profiles of passive films formed on niobium metal and niobium-base alloys by Auger electron spectrometry  

International Nuclear Information System (INIS)

Concentration profiles of passive films formed on electrolytically anodized niobium and niobium-base alloys are obtained by Auger Electron Spectroscopy with simultaneous ion beam etching. The alloys investigated include 5Zr-Nb, 3Zr-10Ti-Nb, 2.5Zr-2W-Nb, and 1Zr-5Mo-5V-Nb. Experiments demonstrate that AES is among the most fascinating techniques for solving various characterization problems related to the structure and composition of the thin films formed by anodization. Data presented supports evidence that combined anodic and cathodic movements take place during film growth. 11 figures.

1976-01-01

112

Recovery of rare earths from red mud  

International Nuclear Information System (INIS)

The prospect for the recovery of rare earths from red mud, the bauxite tailings from the production of alumina is examined. The Jamaican red mud by far has the higher trace concentrations of lanthanum, cerium, neodymium, and yttrium. Scandium is also present. The dissolution of the rare earth is a major extraction problem because of the large volume of other materials. The recovery processes that have been proposed include the production of co-products such as iron, alumina, and titanium concentrates, with the rare earths going with the titanium. In this paper a critical examination of the possible processes are presented with the recommended research projects to be carried out.

1992-03-01

113

Moment of inertia calculations for some even-even rare earth nuclei  

International Nuclear Information System (INIS)

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

114

A small particle selective emitter for thermophotovoltaic energy conversion  

Energy Technology Data Exchange (ETDEWEB)

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.}

1996-02-01

115

The rare earth antimonates: spectroscopic properties, crystal field and paramagnetic susceptibility simulations  

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.

1990-09-01

116

Rayleigh Scattering in Rare Gas Liquids  

CERN Document Server

The Rayleigh scattering length has been calculated for rare-gas liquids in the ultraviolet for the frequencies at which they luminesce. The calculations are based on the measured dielectric constants in the gas phase, except in the case of xenon for which measurements are available in the liquid. The scattering length mayplace constraints on the design of some large-scale detectors, using uv luminescence, being proposed to observe solar neutrinos and dark matter. Rayleigh scattering in mixtures of rare-gas mixtures is also discussed.

2002-01-01

117

Energy transfer processes in rare-earth compounds  

International Nuclear Information System (INIS)

In this thesis the results are described of an investigation into the radiationless transfer of electronic excitation energies in various Eu"3"+ and Tb"3"+ compounds, which show structural peculiarities in the rare-earth sublattice. These peculiarities are an one-dimensional sublattice as well as two different crystallographic locations for the rare-earth ion. 154 refs.; 43 figs.; 12 tabs.

1999-01-01

118

Study on the interface of PVDF coatings and HF-treated AZ31 magnesium alloy: Determination of interfacial interactions and reactions with self-healing properties  

International Nuclear Information System (INIS)

Research highlights: ? Reports a high protection system for the alloy in corrosive environment. ? Describes an interfacial process with self-healing properties. ? Reports the influence of substrate pre-treatment in the coating performance. - Abstract: In this paper the interface of poly(vinylidene fluoride) coatings prepared by the dip coating method and HF-treated AZ31 magnesium alloy was evaluated. The best performance of this system in corrosion tests compared to ground, as-received and acetic acid cleaned substrates is related to an acid-base interaction at the interface and to interfacial reactions which resulted in a self-healing process. The protectiveness of the samples was investigated using impedance and immersion tests while the coating morphology and interface stability were investigated by scanning electron microscopy, X-ray photoelectron spectroscopy and adhesion tests.

2011-02-01

119

Novel, convenient, and nonpersistent radiotracer for environmental and energy applications  

Energy Technology Data Exchange (ETDEWEB)

A newly-available radioisotopic system, /sup 172/Hf-/sup 172/Lu, has excellent potential for tracer applications in which nuclear data acquisition must be accomplished in real time. The 6.7-day half-life of /sup 172/Lu is sufficient for a large fraction of tracer experiments, and should allow the direct incorporation of /sup 172/Lu into tests that have traditionally utilized much longer-lived radionuclides. Since /sup 172/Lu is the daughter component of a radioisotope generator, however, its effective shelf-life is determined by the half-life of its 1.9-year /sup 172/Hf parent. Consequently, the frequency of isotope procurement need not be any more extensive than investigators would normally be accustomed to. Discussion relevant to isotope production, generator operation, and nuclide acquisition is presented in this paper.

1984-03-12

120

Morphology evolution of Ir-Nb-X (X = Hf, Ta, or Ti) ternary alloys  

Energy Technology Data Exchange (ETDEWEB)

The microstructure evolution of nine samples from three Ir-base ternary systems, Ir-Nb-Hf, Ir-Nb-Ta, and Ir-Nb-Ti, was investigated by microstructure observation using scanning electron microscopy (SEM), composition map-analysis using electron probe microscopy analysis (EPMA), and phase determination using X-ray diffraction (XRD) patterns. The fcc/L1{sub 2} two-phase structure was detected in all the samples. Lattice misfits between fcc and L1{sub 2} phases were calculated. Ir-Nb-Ta and Ir-Nb-Ti alloys exhibited a microstructure quite similar to that of Ni-base superalloys, and the cuboidal L1{sub 2} precipitates in Ir-Nb-Ta and Ir-Nb-Ti alloys could maintain up to 1900 {sup o}C.

2007-01-31

121

Enhanced reflectance mirrors for space-borne HF laser applications  

Science.gov (United States)

Combined electron, photon, and intense UV irradiation tests have been carried out on three mirror designs, (Si, Al/sub 2/O/sub 3/)/sub 2/Ag, (Si, SiOx)nAg, and (ZnS, Al/sub 2/O/sub 3/)4Ag, to investigate their suitability for space-borne chemical laser applications. It is found that the (Si, oxide)nAg enhanced-reflectance design is a viable candidate for such applications, whereas ZnS, in combination with either ThF/sub 4/ or Al/sub 2/O/sub 3/, shows unacceptably high absorption increases at the 2.8-micron HF laser wavelength with irradiation. It is pointed out, however, that further experiments are needed to fully understand the effect of irradiation on the (Si, oxide)nAg enhanced-reflectance mirrors.

1981-01-01

122

Age determination of meteorites using radioactive nuclides  

Energy Technology Data Exchange (ETDEWEB)

Recently, the precise isotope ratios of some refractory elements in meteorites have been reported using inductively coupled plasma mass spectrometry. The in situ decay of {sup 182}Hf (T{sub 1/2}=9 Myr), which was produced at the latest nucleosynthesis, is recognized in many meteorites as isotopic anomalies of its daughter isotope, {sup 182}W. The degrees of relative {sup 182}W isotopic deviation in extra-terrestrial and terrestrial silicate samples vary from +0.3% to {+-}0% related to the size of their parent bodies. One ready interpretation of its correlation is the difference in timing of metal-silicate separation in the parent bodies. Between the earth and meteorite parent bodies, the difference is calculated to be about four times of the half-life of {sup 182}Hf, equivalent to 36 Myr. (author)

2002-07-01

123

Adsorption of Db and its homologues Nb and Ta, and the pseudo-homologue Pa on anion-exchange resin in HF solution  

Energy Technology Data Exchange (ETDEWEB)

Anion-exchange chromatography of element 105, dubnium (Db), produced in the {sup 248}Cm({sup 19}F, 5n){sup 262}Db reaction is investigated together with the homologues Nb and Ta, and the pseudo-homologue Pa in 13.9 M hydrofluoric acid (HF) solution. The distribution coefficient (K{sub d}) of Db on an anion-exchange resin is successfully determined by running cycles of 1702 chromatographic column separations. The result clearly indicates that the adsorption of Db on the resin is significantly different from that of the homologues and that the adsorption of anionic fluoro complexes of these elements decreases in the sequence of Ta{approx}Nb>Db{>=}Pa. (orig.)

2009-07-01

124

Adsorption of Db and its homologues Nb and Ta, and the pseudo-homologue Pa on anion-exchange resin in HF solution  

International Nuclear Information System (INIS)

Anion-exchange chromatography of element 105, dubnium (Db), produced in the "2"4"8Cm("1"9F, 5n)"2"6"2Db reaction is investigated together with the homologues Nb and Ta, and the pseudo-homologue Pa in 13.9 M hydrofluoric acid (HF) solution. The distribution coefficient (K_d) of Db on an anion-exchange resin is successfully determined by running cycles of 1702 chromatographic column separations. The result clearly indicates that the adsorption of Db on the resin is significantly different from that of the homologues and that the adsorption of anionic fluoro complexes of these elements decreases in the sequence of Ta#approx#Nb>Db#>=#Pa. (orig.)

125

Treatment of a waste salt delivered from an electrorefining process by an oxidative precipitation of the rare earth elements  

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...

2009-01-01

126

The sorption recovery of rare earth elements, yttrium and aluminium from the red mud  

International Nuclear Information System (INIS)

The extraction of rare earth elements, yttrium and aluminium from red mud resulting from alumina production with the ion-exchange resin KU-2-8n was studied. Experimental results are presented. The technology of hydrometallurgical processing of pulps obtained by sorption extraction of scandium from red mud is developed. It is shown that in the process of precipitation from sulfate sulfuric acid desorbate it became possible to obtain a high degree of rare earths deposition. The use of sodium hydroxide makes it possible to obtain a maximum deposition of rare earths and aluminium - 99.9 %. Aluminium leaching from crude composite concentrate gives a possibility to get concentrates which 15 - 20 times richer in yttrium and rare earths

2002-08-01

127

Treatment of a waste salt delivered from an electrorefining process by an oxidative precipitation of the rare earth elements  

Energy Technology Data Exchange (ETDEWEB)

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 (CeO{sub 2}, PrO{sub 2}), 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 ...

2009-02-28

128

Treatment of a waste salt delivered from an electrorefining process by an oxidative precipitation of the rare earth elements  

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 ...

2009-02-28

129

Study on a recovery of rare earth oxides from a LiCl-KCl-RECl3 system  

British Library Electronic Table of Contents (United Kingdom)

Radioactive rare earth chlorides in waste LiCl-KCl molten salts have to be separated as a stable form to minimize waste volume and to achieve stable solidification. In this work, thermal behavior of rare earth chlorides (CeCl3, GdCl3, NdCl3, PrCl3) was investigated in an oxygen condition to recover rare earth oxides from a LiCl-KCl-RECl3 system. The rare earth chlorides in the LiCl-KCl molten salts were smoothly converted to an oxychloride form at a higher temperature than 650degreeC, except for CeCl3. CeCl3 was totally converted to an oxide from at a higher temperature than 450degreeC. The rare earth oxychlorides (GdOCl, NdOCl, PrOCl) were effectively converted to oxide forms at a higher temperature than 1100degreeC. It was confirmed that rare earth oxides can be recovered from a LiCl-KCl...

2011-01-01

130

Investigation of the evaporation of rare earth chlorides in a LiCl-KCl molten salt  

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 ...

2011-02-01

131

The ternary silicide ZrPd{sub 3}Si{sub 3}, a stacking variant of the {alpha}-FeSi{sub 2} and Re{sub 3}B structure types  

Energy Technology Data Exchange (ETDEWEB)

The ternary zirconium palladium silicide ZrPd{sub 3}Si{sub 3} has been synthesized by arc-melting of the elemental components. It adopts a new structure type and crystallizes in the orthorhombic space group Cmcm with a = 3.8127(4){angstrom}, b = 15.551(1){angstrom}, c = 7.0390(5){angstrom}, and Z = 4 (Pearson symbol oC28). The structure can be regarded as being built up of Re{sub 3}B-type slabs of composition Pd{sub 3}Si alternating with {alpha}-FeSi{sub 2} slabs of composition ZrSi{sub 2}. Notable features include the presence of Si{sub 2} pairs, square pyramidal and tetrahedral coordination of Pd centers by Si atoms, an unusual distorted cubic coordination of the Zr atoms by the Si{sub 2} pairs, and an extensive network of Zr-Zr, Zr-Pd, and Pd-Pd metal-metal bonds. ZrPd{sub 3}Si{sub 3} is weakly metallic with a room-temperature resistivity of 1.7 x 10{sup ...

1999-11-01

132

The Relationship between the Microstructure and Age Hardening Response in the Metastable Beta Titanium Alloy Ti-11.5Mo-6Zr-4.5Sn (Beta III).  

Science.gov (United States)

The effect of solution treatment temperature and oxygen content on the microstructure and age hardening response of the metastable beta alloy Ti-11.5Mo-6Zr-4.5Sn have been studied. Kinetics of formation of the equilibrium alpha-phase and the metastable om...

1977-01-01

133

Shape coexistence and extreme deformations near A =80  

Energy Technology Data Exchange (ETDEWEB)

The neutron deficient Sr and Zr nuclei are studied in the relativistic mean-field approach. Large deformations and shape coexistence are predicted for these nuclei in the vicinity of the proton drip line. The charge radii are found to increase with the removal of neutrons from the semimagic {sup 88}Sr and {sup 90}Zr, in close agreement with the recent isotopic-shift measurements.

1992-10-01

134

Observation of double analog states in "8"8Zr and "9"0Mo and the neutron excess and mass systematics of pion double charge exchange  

International Nuclear Information System (INIS)

The first successful observation of double analog states in "8"8Zr and "9"0Mo has been made by means of the (#pi#"+,#pi#"-) pion double charge exchange (DCX) reaction. The systematics of the (N - Z) and the A dependence of analog DCX, made possible by these observations, is discussed. (orig.).

135

Influence of the oxygen partial pressure on the reduction of CeO{sub 2} and CeO{sub 2}-ZrO{sub 2} ceramics  

Energy Technology Data Exchange (ETDEWEB)

Based on recent thermodynamic estimations on the CeO{sub 2}-CeO{sub 1.5}, CeO{sub 2}-2ZrO{sub 2} and CeO{sub 1.5}-ZrO{sub 2} systems, isothermal sections of the ternary CeO{sub 2}-ZrO{sub 2}-CeO{sub 1.5} system are calculated in the 1300-1700 C region. Additionally, the complex relation between the nonstoichiometry, y, in CeO{sub 2-y}, the composition of the CeO{sub 2}-ZrO{sub 2} solid solution and the oxygen partial pressure (PO{sub 2}) for different ZrO{sub 2} containing solid solutions Ce{sub z}Zr{sub 1-z}O{sub 2-x} (with z=0.2, 0.5, 0.8) are evaluated from 600 to 900 C. The relation between the degree of Ce{sup +4} to Ce{sup +3} reduction under different PO{sub 2} in the fluorite CeO{sub 2-y} and Ce{sub z}Zr{sub 1-z}O{sub 2-x} solid solutions at different temperatures can be used as a guide in the development of functional ceramics or ...

2005-07-01

136

EXCITATION OF ISOBARIC ANALOG STATES IN $sup 89$Y AND $sup 90$Zr  

Science.gov (United States)

The excitation of compound-nucleus resonances in Y/sup 89/ and Zr/sup 90/ by proton bombardment at 4 to 5.5 Mev of Sr/sup 88/ and Y/sup 89/, respectively, is reported. Shell-model corfigurations were used to interpret the results. (R.E.U.)

1964-02-24

137

Anelastic strain recovery of amorphous metals. [80 Pd--20 Si; 80 Fe--13 P--7 C; 60 Cu--40 Zr  

Science.gov (United States)

This paper describes the anelastic strain recovery and the strain hardening of amorphous metals and presents the experimental result that creep deformation is represented by a viscoelastic model consisting of rheological elements. Materials studied were 80Pd--20Si, 80Fe--13P--7C, and 60 Cu--40 Zr. (DLC)

1976-08-01

138

X-ray microanalysis of Al/Zr multilayers in the transmission electron microscope  

International Nuclear Information System (INIS)

A one-nanometer scale transmission electron microscope electron probe X-ray microanalysis characterization of as-deposited and annealed aluminum--11.5 at.% zirconium multilayer samples in cross-section synthesized by magnetron sputtering is reported on here. Composition line profiles were acquired across Zr layers in as-deposited material and samples isochronally annealed in a differential scanning calorimeter to temperatures of 290 C and 485 C. A spatial resolution of approximately 1.5 to 2.0 nm was achieved in these experiments and will be improved by deconvolution of the instrumental electron probe function from the data. The as-deposited structure consisted of crystalline Al and Zr layers with thin amorphous layers at the Al/Zr interfaces. The amorphous interface layers increased in thickness upon annealing to 290 C. Additionally, at 290 C a metastable cubic alloy forms at the Zr deposited on Al ...

1997-04-04

139

Physical characterization of a new composition of oxidized zirconium-2.5wt% niobium produced using a two step process for biomedical applications  

British Library Electronic Table of Contents (United Kingdom)

Zirconium and particularly Zr-2.5wt%Nb (Zr2.5Nb) alloy are useful for engineering bearing applications because they can be oxidized in air to form a hard surface ceramic. Oxidized zirconium (OxZr) due to its abrasion resistant ceramic surface and biocompatible substrate alloy has been used as a bearing surface in total joint arthroplasty for several years. OxZr is characterized by hard zirconium oxide (oxide) formed on Zr2.5Nb using one step thermal oxidation carried out in air. Because the oxide is only at the surface, the bulk material behaves like a metal, with high toughness. The oxide, furthermore, exhibits high adhesion to the substrate because of an oxygen-rich diffusion hardened zone (DHZ) interposing between the oxide and the substrate. In this study, we demonstrate a two step pro...

2011-01-01

140

The Analysis of Turbulence and Rotation U-3M Torsatron Plasma During Transport Barriers Formation  

International Nuclear Information System (INIS)

The analysis of plasma density oscillations and ExB rotation of U-3M torsatron plasma was performed by UHR correlation reflectometry during the transport barrier formation. The connections between these characteristics and the phenomenon of inner and edge transport barrier formation were determined experimentally at the different values of HF power and plasma density.

2006-01-01

141

Removal of noxious contaminants from gas  

Science.gov (United States)

Gas contaminated with at least one noxious component, such as SO/sub 2/, HF or NOx, is scrubbed with a clear, calcium-containing, initially-basic washing liquid which also comprises the anion of a strong inorganic acid, that of a polybasic carboxylic acid and, optionally, that of a monobasic carboxylic acid. Apparatus is provided for scrubbing the gas, oxidizing produced calcium bisulfite to calcium sulfate, separating out and removing solids, and recirculating clarified liquid for scrubbing contaminated gas.

1980-09-16

143

Extraction behavior of short-lived isotopes of Mo/W using {alpha}-benzoinoxime: a model system for the study of seaborgium  

Energy Technology Data Exchange (ETDEWEB)

The liquid-liquid extraction behavior of short-lived molybdenum and tungsten isotopes from HCl and HNO{sub 3} as well as HF/HNO{sub 3} acid media was studied using the {alpha}-benzoinoxime/chloroform system. The goal of the present experiments was to find an extraction system with a high selectivity for the group 6 elements in the periodic table which is suitable for the study the solution chemistry of seaborgium (Z = 106). It was found that Mo and W are both effectively extracted using {alpha}-benzoinoxime as an extractant and the maximum extraction yield is 100% and 94% for Mo and W, respectively. Ions of MO{sub 2}{sup 2+} (M = Mo, W) exist in HCl between the concentration range of 0.1-3 M and can be extracted quantitatively into the organic phase. The decrease of extraction yields at lower or higher acid concentration is due to the formation of anionic species MO{sub 4}{sup 2-} or MO{sub 2}Cl{sub 3}{sup -}. The extraction behavior of Mo and W in HNO{sub 3} ...

2009-07-01

144

Extraction behavior of short-lived isotopes of Mo/W using #alpha#-benzoinoxime: a model system for the study of seaborgium  

International Nuclear Information System (INIS)

The liquid-liquid extraction behavior of short-lived molybdenum and tungsten isotopes from HCl and HNO_3 as well as HF/HNO_3 acid media was studied using the #alpha#-benzoinoxime/chloroform system. The goal of the present experiments was to find an extraction system with a high selectivity for the group 6 elements in the periodic table which is suitable for the study the solution chemistry of seaborgium (Z = 106). It was found that Mo and W are both effectively extracted using #alpha#-benzoinoxime as an extractant and the maximum extraction yield is 100% and 94% for Mo and W, respectively. Ions of MO_2"2"+ (M = Mo, W) exist in HCl between the concentration range of 0.1-3 M and can be extracted quantitatively into the organic phase. The decrease of extraction yields at lower or higher acid concentration is due to the formation of anionic species MO_4"2"- or MO_2Cl_3"-. The extraction behavior of Mo and W in HNO_3 solution is similar to that in HCl solution. In ...

145

Dissociation energies of HfO and ThO  

International Nuclear Information System (INIS)

The RKR potential energy curves are constructed for the ground states of diatomic hafnium oxide and thorium oxide. Using Lippincott and Hulburt-Hirschfelder potential function the dissociation energies are estimated by curve fitting method. The H-H potential function was found to give a better fit in both cases. The dissociation energies of hafnium oxide and thorium oxide are estimated as 9.04 #+-# 0.02 eV and 10.34 #+-# 0.01 eV respectively. (author).

146

Application of an on-line measurement system for HF emission control (2. part); Application d'un systeme de mesure en ligne pour le controle des emissions de fluor (2. partie)  

Energy Technology Data Exchange (ETDEWEB)

In the last issue of 'L'Industrie ceramique et verriere', we presented the first part of this study. We describe in this issue the experimental procedure, the results and the conclusions of this work. (authors)

2005-02-01

147

Detection of high-frequency radiation sources during the 2004 Parkfield earthquake by a matched filter analysis  

Science.gov (United States)

Introduction Uchide and Ide [SSA Spring Meeting, 2009] proposed a new framework for studying the scaling and overall nature of earthquake rupture growth in terms of cumulative moment functions. For better understanding of rupture growth processes, spatiotemporally local processes are also important. The nature of high-frequency (HF) radiation has been investigated for some time, but its role in the earthquake rupture process is still unclear. A wavelet analysis reveals that the HF radiation (e.g., 4 - 32 Hz) of the 2004 Parkfield earthquake is peaky, which implies that the sources of the HF radiation are isolated in space and time. We experiment with applying a matched filter analysis using small template events occurring near the target event rupture area to test whether it can reveal the HF radiation sources for a regular large earthquake. Method We design a matched filter for multiple components and ...

2009-12-01

148

Study of even-A zirconium and strontium isotopes with the (d,"6Li) reaction  

International Nuclear Information System (INIS)

All stable even-A molybdenum isotopes and sup(90,92)Zr have been investigated with the (d, "6Li) reaction at Esub(d) = 45 MeV to study proton- and neutron-pair correlations. Differential cross sections were measured for states up to Esub(x) = 3 MeV in "8"6Sr, sup(88,92,94,96)Zr and up to 6 MeV in "8"8Sr and "9"0Zr. Particular attention was paid to the comparison of #alpha#-pickup data with two-nucleon pickup data. The population of low-lying 0"+ and 5"- states for two-neutron and four-nucleon pickup reactions was calculated using simple phenomenological wave functions for the initial and final states. The results of these calculations are in satisfactory agreement with the data. (orig.).

149

Production of powder titanium alloys with Mo, Zr, Nb additions and their properties  

International Nuclear Information System (INIS)

In order to substitute expensive cast titanium alloys by powder ones the possibility of introduction of powder additions by mechanical stock mixing is studied. It is shown that microstructure of powder alloys of Ti-Zr(1-9%) system is typical for one-phase cast #alpha#-alloys. The Ti-Mo(1-9%) and Ti-Nb(1-9%) system alloys have microstructure typical for two-phase (#alpha#+#beta#)-alloys. For homogeneous structure to be obtained the high temprature annealing is advisable after hot pressing. Alloying with Mo, Zr and Nb permits to increase considerable the strength of powder titanium products (at 9% Mo more than two times).

150

Microstructure and fracture toughness of hot pressed zirconia-toughened sialon  

International Nuclear Information System (INIS)

Zirconia-toughened sialon composites have been fabricated using conventional hot-pressing techniques. The fracture toughness and microstructure were determined for CeO_2- and Y_2O_3-stabilized ZrO_2 additives and also as a function of volume percent ZrO_2. The Yttria system showed a linear increase in fracture toughness with increasing volume fraction zirconia content while the ceria-stabilized system exhibited a peak in fracture toughness at 20 vol% ZrO_2 content. The fracture toughness at 800 C was measured and correlated with the microstructure. High-temperature stability was determined and it was found that the deleterious nitride phases of zirconium could be precluded from the microstructure.

151

Hydriding properties of a mechanically milled Mg-50 wt.% ZrFe{sub 1.4}Cr{sub 0.6} composite  

Energy Technology Data Exchange (ETDEWEB)

The ball-milling method was used to produce Mg-50 wt.% ZrFe{sub 1.4}Cr{sub 0.6} composite. The thermodynamic, kinetic, and cycling properties, as well as the resistance to oxidation were examined. This composite possesses excellent kinetic properties, even at moderate temperature. Scanning electron microscopy, energy-dispersive spectrum, transmission electron microscopy and X-ray diffraction were used to characterize the composite before and after hydriding. The fine ZrFe{sub 1.4}Cr{sub 0.6} particles covering Mg particles acting as a ''catalytic film'', a significant amount of imperfections and some alloy powder in the Mg matrix introduced by ball milling all contributed to the enhanced absorption/desorption rate. (orig.)

2000-02-02

152

High temperature deformation of the Al-5Cr-2Zr alloy as a function of powder particle diameter  

International Nuclear Information System (INIS)

The powder particle size, D, influences the creep behaviour of Al-Cr-Zr alloys. The alloy studied in this work, Al-5Cr-2Zr (mass%), was prepared by argon atomization. Three size fractions of powder particles were selected: 24-50 #mu#m, 50-100#mu#m and 100-200 #mu#m in diameter. They were consolidated by extrusion. Independently of D, the flow behaviour of the alloy can be described by the power law equation. As test temperature increases, the stress exponent n decreases up to a value close to 5. A decrease of D causes an increase of n and delays the alloy degradation at high temperature. (Author) 11 refs.

1998-01-01

153

The rare earth antimonates: spectroscopic properties, crystal field and paramagnetic susceptibility simulations  

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.

1991-01-01

154

Treatment of LiCl-KCl eutectic waste salt delivered from pyroprocessing of spent oxide fuel  

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.

2008-08-15

155

Treatment of LiCl-KCl eutectic waste salt delivered from pyroprocessing of spent oxide fuel  

International Nuclear Information System (INIS)

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

2008-08-01

156

Study of cytomorphology of solid pseudopapillary tumor of pancreas and its differential diagnosis  

UK PubMed Central (United Kingdom)

Background:Solid pseudopapillary tumor is a rare pancreatic neoplasm with uncertain to low malignant potential. This is an uncommon neoplasm with many pseudonyms, occurring...Full Text Available

2010-10-01

157

Recurrent spontaneous pneumothorax during pregnancy: a case report  

UK PubMed Central (United Kingdom)

IntroductionSpontaneous recurrent pneumothorax during pregnancy is a rare condition. Few cases have been reported previously in the literature. There is no universal guideline for...Full Text Available

158

Recurrent corneal ulceration in presence of synthetic microfibrils  

UK PubMed Central (United Kingdom)

Recurrence of microbial keratitis in the presence of protozoal infection is very rare and infrequently reported unless predisposing factors are present. The association of recurrent microbial keratitis...Full Text Available

2011-01-01

159

Rare Book and Special Collections Reading Room (Library of Congress...  

Science.gov (United States)

any locality that is now in the United States. The English fleet lies at anchor, the infantry troops having disembarked and are attacking the Spanish settlement on May 28 and 29,...

2011-06-02

160

Rare B decays  

Energy Technology Data Exchange (ETDEWEB)

The current status of rare B decays is reviewed based on recent observation of the penguin-diagram decay B {yields} K{sup *}{gamma} at CLEO. Rare B decays provide valuable information on the Standard Model parameters, and also could be a source of direct CP violation. It is emphasized that new physics beyond the Standard Model can appear in rare B decays, in some cases more drastically than in the CP Asymmetry of the B system. Inclusive measurement of the radiative transition b {yields} s{gamma} is promising. Hadronic penguin modes are very close to being observed at CLEO, and a discovery might be just around the corner. (author). 48 refs., 6 figs., 4 tabs.

1994-12-31

163

Management of primary sclerosing cholangitis  

UK PubMed Central (United Kingdom)

Primary sclerosing cholangitis (PSC) is a rare cholestatic liver disease with major morbidity and mortality. Therapeutic management is difficult, due to lack of conclusive data and individual disease...Full Text Available

2011-06-27

164

Lung carcinoma with hypertrophic osteoarthropathy in a teenager  

UK PubMed Central (United Kingdom)

Hypertrophic osteoarthropathy (HOA) characterised by arthralgia, clubbing and periosteal proliferation of long bones, is rarely encountered in children and adolescents. Whereas in adults over 80% of...Full Text Available

165

Late Life-Threatening Hemorrhage after Percutaneous Tracheostomy  

UK PubMed Central (United Kingdom)

Purpose. Formation of a tracheoinnominate artery fistula (TIF) and consecutive hemorrhage is a rare and life-threatening complication with high mortality. Warning symptoms can...Full Text Available

2011-01-01

166

Is sirolimus a therapeutic option for patients with progressive pulmonary lymphangioleiomyomatosis?  

UK PubMed Central (United Kingdom)

BackgroundLymphangioleiomyomatosis (LAM) is a rare lung disease characterised by progressive airflow obstruction. No effective medical treatment is available but therapy with sirolimus...Full Text Available

2011-01-01

167

Idiopathic (primary) achalasia  

UK PubMed Central (United Kingdom)

Idiopathic achalasia is a primary esophageal motor disorder characterized by esophageal aperistalsis and abnormal lower esophageal sphincter (LES) relaxation in response to deglutition. It is a rare...Full Text Available

168

Extraction of rare earths by carbonic acids melts  

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.

1980-10-01

169

Embryonic Senescence and Laminopathies in a Progeroid Zebrafish Model  

UK PubMed Central (United Kingdom)

BackgroundMutations that disrupt the conversion of prelamin A to mature lamin A cause the rare genetic disorder Hutchinson-Gilford progeria syndrome and a group of laminopathies....Full Text Available

170

Electric and magnetic dipole transitions in odd-proton rare-earth nuclei  

International Nuclear Information System (INIS)

... gamma cascades kev range 10-100 lifetime lutetium 171 lutetium 173 lutetium

1972-05-01

171

Effects of Climatic Variability and Land Use on American Drylands...  

Science.gov (United States)

Wildlife Refuge, CA Rare and endangered endemic plants Diana Anderson Northern Arizona University Geomorphology Kathryn Thomas USGS, Flagstaff, AZ Vegetation dynamics John...

2011-09-30

172

Deep-sea mud in the Pacific Ocean as a potential resource for rare-earth elements  

British Library Electronic Table of Contents (United Kingdom)

World demand for rare-earth elements and the metal yttrium?which are crucial for novel electronic equipment and green-energy technologies?is increasing rapidly. Several types of seafloor sediment harbour high concentrations of these elements. However, seafloor sediments have not been regarded as a rare-earth element and yttrium resource, because data on the spatial distribution of these deposits are insufficient. Here, we report measurements of the elemental composition of over 2,000 seafloor sediments, sampled at depth intervals of around one metre, at 78 sites that cover a large part of the Pacific Ocean. We show that deep-sea mud contains high concentrations of rare-earth elements and yttrium at numerous sites throughout the eastern South and central North Pacific. We estimate that an a...

2011-01-01

173

Cardiac Angiosarcoma-Associated Membranoproliferative Glomerulonephropathy  

UK PubMed Central (United Kingdom)

Primary cardiac angiosarcoma is a rare cardiac tumor. The initial clinical course is often asymptomatic, and metastatic disease is present in a majority of affected patients at diagnosis. We present...Full Text Available

2011-01-01

174

Application of a New Approach for Estimating LOCA and SGTR Frequencies  

Energy Technology Data Exchange (ETDEWEB)

The needs for more reasonable estimations for rare and extremely rare initiating events (IEs) have been reported in US peer review results. The American Society of Mechanical Engineers (ASME) PRA standard also proposes guidelines and requirements about the issues. Recently, US NRC addressed problems and the conservative assumptions on loss-of-coolant accident (LOCA) analysis and attempted to establish more rigorous methodology for estimating the frequencies depending on break size. The results of peer reviews for KHNP reference plants also represented that the data used in estimating IEs were outdated and the methodology also needed to be improved. In this paper, for more appropriate estimation of rare and extremely rare initiating events (IEs), e.g., LOCAs and steam generator tube ruptures (SGTRs), a new approach considering expert elicitation process is presented and corresponding core damage ...

2010-05-15

175

A child with hyperferritinemia: Case report  

UK PubMed Central (United Kingdom)

Hereditary hyperferritinemia cataract syndrome (HHCS) is a rare condition caused by mutations in the gene coding for the light chain of ferritin; it does not lead to iron overload, but it is associated...Full Text Available

177

Polypropylene obtained through zeolite supported catalysts  

Energy Technology Data Exchange (ETDEWEB)

Propylene polymerizations were carried out with {phi}{sub 2}C(Flu)(Cp)ZrCl{sub 2} and SiMe{sub 2}(Ind)2ZrCl{sub 2} catalysts supported on silica, zeolite sodic mordenite (NaM) and acid mordenite (HM). The polymerizations were performed at different temperatures and varying aluminium/zirconium molar ratios ([Al]/[Zr]). The effect of these reaction parameters on the catalyst activity was investigated using a proposed statistical experimental planning. In the case of f{sub 2}C(Flu)(Cp)ZrCl{sub 2}, SiO{sub 2} and NaM were used as support and the catalyst performance evaluated using toluene and pentane as polymerization solvent. The molecular weight, molecular weight distribution, melting point and crystallinity of the polymers were examined. The results indicate very high activities for the syndiospecific heterogeneous system. Also, the polymers obtained had superior Mw and stereo regularity. (author)

2004-07-01

178

Polypropylene obtained through zeolite supported catalysts  

International Nuclear Information System (INIS)

Propylene polymerizations were carried out with #phi#_2C(Flu)(Cp)ZrCl_2 and SiMe_2(Ind)2ZrCl_2 catalysts supported on silica, zeolite sodic mordenite (NaM) and acid mordenite (HM). The polymerizations were performed at different temperatures and varying aluminium/zirconium molar ratios ([Al]/[Zr]). The effect of these reaction parameters on the catalyst activity was investigated using a proposed statistical experimental planning. In the case of f_2C(Flu)(Cp)ZrCl_2, SiO_2 and NaM were used as support and the catalyst performance evaluated using toluene and pentane as polymerization solvent. The molecular weight, molecular weight distribution, melting point and crystallinity of the polymers were examined. The results indicate very high activities for the syndiospecific heterogeneous system. Also, the polymers obtained had superior Mw and stereo regularity. (author)

2004-01-01

179

Laser hardening of titanium-zirconium alloy  

International Nuclear Information System (INIS)

The methods of surface modification of Ti-Zr alloy by laser treatment are considered. Characteristics of laser modification without- and with surface melting and with melting in different gaseous environments and with nickel microalloying are presented. Maximum depth, hardness and corrosion resistance are observed under nickel laser alloying.

180

LITERATURE SURVEY OF THE CORROSION BEHAVIOR OF TANTALUM, ZIRCONIUM, AND TITANIUM  

Science.gov (United States)

The corrosion behavior of Ta, Ti, and Zr in inorganic acids, bases, chlorides and miscellaneous salts, waters and gases, and organic acids and miscellaneous organic chemicals is summarized. (W.L.H)

1955-02-23

181

Enhancement of glass-forming ability and bio-corrosion resistance of Zr-Co-Al bulk metallic glasses by the addition of Ag  

International Nuclear Information System (INIS)

A novel Ni and Cu-free Zr-based bulk metallic glass (BMG) system with enhancement of glass-forming ability (GFA) and bio-corrosion resistance was prepared by copper mold casting by the addition of Ag. It was found that the addition of Ag can considerably enhance the glass-forming ability, as indicated by the increase of the critical glass dimension from 3 mm diameter of the ternary system to over 10 mm in the alloy of Zr_5_3Co_1_8_._5Al_2_3_._5Ag_5. The bio-corrosion behaviors of the Zr-based BMGs in phosphate buffered solution (PBS) were investigated by electrochemical polarization at 310 K. It was found that the addition of appropriate amount of Ag can enhance the corrosion resistance of the BMGs. The X-ray photoelectron spectroscopy (XPS) indicated that the formation of an Al_2O_3-enriched passive film is mainly responsible for the high corrosion resistance of Ag-bearing alloy in phosphate buffered solution.

2010-08-01

185

Two-proton excitations at the Z=38 and Z=40 sub-shell closures  

International Nuclear Information System (INIS)

The "8"6Kr("3He,n)"8"8Sr and "8"8Sr("3He,n)"9"0Zr reactions were studied to determine whether significant excited 0"+ strength was observed or whether these nuclei exhibited absence of excited state strength generally seen away from shell closures. Various properties of the levels are considered including angular distributions, spins, parities, interference, and enhancement. It is concluded that neither "8"8Sr nor "9"0Zr exhibit the strong proton pairing vibration expected for a closed proton shell nucleus.

1977-11-01

186

Session 6: Redox Behavior of Cerium-Zirconium-Bismuth Mixed Oxides  

Energy Technology Data Exchange (ETDEWEB)

The CeO{sub 2}-ZrO{sub 2}-Bi{sub 2}O{sub 3} samples with different bismuth content were prepared in this study. By the doping of Bi{sub 2}O{sub 3} into the lattice, TPR profiles of the CeO{sub 2}-ZrO{sub 2} shifted to lower temperatures and oxygen storage capacity increased remarkably. It is concluded that the reason for such a behavior is probably due to both the formation of oxygen vacancies which enhance the oxygen mobility and the simultaneous reduction of Ce{sup 4+} and Bi{sup 3+} in the mixed oxides. (authors)

2004-07-01

187

Nanocrystallization of the amorphous Fe_1_4Ni_4_0Zr_7B_1_2 alloys studied by the Moessbauer spectroscopy  

International Nuclear Information System (INIS)

Formation of the soft magnetic nanostructure in amorphous Fe_1_4Ni_4_0Zr_7B_1_2 alloy due to heat treatment is studied by the Moessbauer, differential scanning calorimetry, and X-ray diffraction techniques. Annealing at temperatures 520-580 "oC leads to the formation of extremely soft nanocrystalline alloy as revealed by the rf-Moessbauer measurements. The superparamagnetic behaviour was observed for the alloy annealed at 620-640 "oC. At higher annealing temperatures good soft magnetic properties deteriorate. (author)

2001-09-23

188

Heat capacity measurement of some breeder materials  

International Nuclear Information System (INIS)

Isobaric molar heat capacities of powder and microsphere form of Li2TiO3 (s) and powder form of LiAlO2 (s) and Li2ZrO3 (s) were measured using a heat flux type differential scanning calorimeter in the temperature range 320 - 870 K. Specific heat capacities of LiAlO2 (s) was found to be much larger compared to those of Li2TiO3 (s) and Li2ZrO3 (s). (author)

2009-01-07

189

Effect of deformation on corrosion behavior of Ti-23Nb-0.7Ta-2Zr-O alloy  

International Nuclear Information System (INIS)

The influence of deformation on the corrosion behavior of a newly developed multifunctional beta titanium alloy Ti-23Nb-0.7Ta-2Zr-O (mol%) in Ringer's solution at 310 K was evaluated using an electron backscatter diffraction technique and electrochemical measurements. The results showed that the effect of deformation on the corrosion resistance of the beta titanium alloy is complicated. Small levels of plastic deformation are detrimental to the corrosion resistance, whereas large deformations tend to eliminate this detrimental effect.

2009-03-01

190

E2 transition densities and proton shell structure in /sup 88/Sr, /sup 89/Y, and /sup 90/Zr  

Energy Technology Data Exchange (ETDEWEB)

Electron scattering data have been used to obtain transition charge densities for the low-lying E2 transitions in /sup 88/Sr, /sup 89/Y, and /sup 90/Zr. These charge densities show a characteristic shape indicative of their microscopic constituency, modified by core-polarization effects. A good description of transitions in the even-even nuclei is obtained by using the measured single-particle transitions in /sup 89/Y as effective densities. .ID LV2086 .PG 19 22

1983-01-03

191

Determination of the #pi#1g/sub 9/2/ orbit size in "8"8Sr, "9"0Zr, and "9"2Mo from inelastic electron scattering  

International Nuclear Information System (INIS)

A study of the #pi#1g/sub 9/2/ orbit size in "8"8Sr, "9"0Zr, and "9"2Mo is presented. The rms radius for the point-proton density is extracted by studying transitions to 8"+ states in these nuclei. The radii are consistently larger than a value determined in a magnetic electron scattering experiment on "9"3Nb. A qualitative discussion of the ground state occupation of the #pi#1g/sub 9/2/ orbit based on the transition amplitudes to the 8"+ states is given.

192

Collective and neutron-structure effects in the elastic scattering of vector polarized deuterons in the A = 90 mass region  

Energy Technology Data Exchange (ETDEWEB)

The analyzing power has been measured for elastic scattering of vector-polarized deuterons from /sup 92,94,96/Zr and /sup 92/Mo at E/sub d/ = 12 MeV. Previous measurements on /sup 88/Sr and /sup 98/Mo have been extended. The present data combined with published measurements on /sup 90,91/Zr and /sup 76,78,80,82/Se show that these angular distributions can be explained only if one considers both collective and neutron structure-dependent effects.

1981-07-01

193

Cluster-phonon model applied to the [sup 91]Zr nucleus  

Energy Technology Data Exchange (ETDEWEB)

The structure of the low-lying levels of the [sup 91]Zr nucleus is discussed in a framework of the cluster-phonon coupling model. In order to describe simultaneously positive- and negative-parity states, octupole as well as quadrupole vibrations of the [sup 88]Sr core are allowed. The cluster states include two single protons coupled to a single neutron. The residual interaction among the cluster particles is assumed to be the modified surface [delta] interaction. Energy levels and electromagnetic properties are calculated and compared with the experimental data.

1993-07-01

194

A study on the development of hypo-stoichiometric Zr-based hydrogen storage alloys with ultra-high capacity for anode material of Ni/MH secondary battery  

Energy Technology Data Exchange (ETDEWEB)

Some hypo-stoichiometric Zr-based Laves phase alloys were prepared and studied from a viewpoint of discharge capacity for electrochemical application. After careful alloy design of ZrMn{sub 2}-based hydrogen storage alloys through changing their stoichiometry while substituting or adding some alloying elements, the Zr(Mn{sub 0.2}V{sub 0.2}Ni{sub 0.6}){sub 1.8} alloy reveals relatively good properties with regard to hydrogen storage capacity, hydrogen equilibrium pressure and electrochemical discharge capacity. In order to improve the discharge capacity and rate-capability, Zr is partially replaced by Ti. The discharge capacity of Zr{sub 1-x}Ti{sub x}(Mn{sub 0.2}V{sub 0.2}Ni{sub 0.6}){sub 1.8} (x=0.0, 0.2, 0.3, 0.4, 0.6) alloy electrodes at 30 C reaches a maximum value and decreases as the Ti fraction increases. In view of electrochemical and thermodynamic characteristics, the ...

2000-08-10

195

104 MeV alpha particle scattering from /sup 90/,/sup 92/Zr  

Energy Technology Data Exchange (ETDEWEB)

Differential cross sections have been measured for the elastic and inelastic scattering of 104 MeV alpha-particles from /sup 90/,/sup 92/Zr. The experimental data are analyzed in terms of coupled channels on the basis of a flexible anharmonic vibrator model and using different parametrizations of the radial shape of the extended optical potential. The results favour the squared Saxon-Woods type for the real part. Additionally to a radial momentum analysis of the real potentials a semimicroscopic folding model has been invoked for extracting isoscalar quadrupole and hexadecapole transition rates.

1982-05-01

196

104 MeV alpha particle scattering from "9"0,"9"2Zr  

International Nuclear Information System (INIS)

Differential cross sections have been measured for the elastic and inelastic scattering of 104 MeV alpha-particles from "9"0,"9"2Zr. The experimental data are analyzed in terms of coupled channels on the basis of a flexible anharmonic vibrator model and using different parametrizations of the radial shape of the extended optical potential. The results favour the squared Saxon-Woods type for the real part. Additionally to a radial momentum analysis of the real potentials a semimicroscopic folding model has been invoked for extracting isoscalar quadrupole and hexadecapole transition rates. (orig.).

197

Self-lubricating performance and durability of ball bearings for the LE-7 liquid oxygen rocket-turbopump  

Energy Technology Data Exchange (ETDEWEB)

The durability of ball bearings, 32-mm- and 45-mm-bore, with a retainer or glass cloth-polytetrafluoroethylene (PTFE) laminate was tested under a high radial load at a speed of 20,000 rpm in LOX or LN2. The retainers were characterized as good self-lubricators because the abrasive glass-cloth fiber tips exposed on the retainer were chemicaly etched away with hydrofluoric acid (HF). During testing, the bearing-cartridge-acceleration was monitored to detect bearing damage. Testing in LOX for about 2.2 hr showed that excellent lubricating conditions were obtained for all bearings. Testing in LN2 for about 5.1 hr detected that the fatigue life of the bearing was about the same as the calculated B10 fatigue life. The HF chemical treatment resulted in a reacted fluoride-oxide material which remained in the etched part of the glass fiber. Several chemical products, particularly MgO, CaO, and CaCO3, enhanced adhesion of PTFE transfer film to the ...

1993-09-01

198

Photoelectrochemistry of disordered passive films  

Energy Technology Data Exchange (ETDEWEB)

A theoretical model, which describes subband gap photoexcitation involving localized electronic states, was developed. The escape probability of a charge carrier trapped in a localized state is considered via Poole-Frenkel, direct tunneling, or phonon-assisted tunneling processes, as competing escape mechanisms. Photoelectrochemical experiments were performed on the passive films formed on zirconium and amorphous iron-zirconium alloys and on pure HfO/sub 2/ films and HfO/sub 2/ films implanted with varying concentrations of xenon. These films were found to possess some degree of disorder depending on the substrate, the thickness of the film, and the extent of implantation. The spectral dependence of the photocurrent in all of the films studied is considerably different from what was found for crystalline passive films. The potential dependence of the photocurrent yields Poole-Frenkel behavior. Reverse tunneling processes were also observed at ...

1987-01-01

199

Nuclear Data Sheets for A = 166  

Energy Technology Data Exchange (ETDEWEB)

Nuclear structure data pertaining to all known A = 166 nuclides (Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt) have been compiled and evaluated, and incorporated into the ENSDF data file. This evaluation for A = 166 supersedes the previous publication (E.N. Shurshikov and N.V. Timofeeva, Nuclear Data Sheets 67, 45 (1992) (literature cutoff date 1 October 1990)) and the revision by C.M. Baglin of {sup 166}W (literature cutoff data 16 April 2000). It includes literature available by 1 March 2008. Subsequent to the previous evaluation, {sup 166}Gd has been observed for the first time and the first observations of excited states in {sup 166}Tb, {sup 166}Re, {sup 166}Os and {sup 166}Ir have been reported: also, knowledge of collective structure in {sup 166}Dy. {sup 166}Ho, {sup 1676}Er, {sup 166}Tm, {sup 166}Yb, {sup 166}Lu, {sup 166}Hf, and {sup 166}Ta has been considerably expanded. However, the structure suggested here for {sup ...

2008-02-06

200

Multi-quasiparticle states in the mass-180 region  

Energy Technology Data Exchange (ETDEWEB)

Nuclei in the mass-180 region have many high-{Omega} single-particle levels close to the Fermi energy and are, therefore, prime candidates for high-K isomers. Since both neutron and proton level densities are rather low, one should expect blocking and particle-number fluctuations to be rather important. We have performed good-particle-number calculations and have shown that the simpler blocked BCS theory gives a good approximation to the multi-quasiparticle spectra if the pairing strength is chosen appropriately. This has allowed us to perform a systematic theoretical study of this mass region. Residual spin-spin interactions are shown to be essential in reproducing the energies and even the correct order of known states. Good agreement has been found for {sup 175}Hf, {sup 176}Hf and {sup 177}Ta, where extensive data already exist. Predictions for new high-K states near the yrast line are made for these nuclei and for {sup 178}W. (orig.).

1995-08-14

201

Multi-quasiparticle states in the mass-180 region  

International Nuclear Information System (INIS)

Nuclei in the mass-180 region have many high-#OMEGA# single-particle levels close to the Fermi energy and are, therefore, prime candidates for high-K isomers. Since both neutron and proton level densities are rather low, one should expect blocking and particle-number fluctuations to be rather important. We have performed good-particle-number calculations and have shown that the simpler blocked BCS theory gives a good approximation to the multi-quasiparticle spectra if the pairing strength is chosen appropriately. This has allowed us to perform a systematic theoretical study of this mass region. Residual spin-spin interactions are shown to be essential in reproducing the energies and even the correct order of known states. Good agreement has been found for "1"7"5Hf, "1"7"6Hf and "1"7"7Ta, where extensive data already exist. Predictions for new high-K states near the yrast line are made for these nuclei and for "1"7"8W. (orig.).

202

Calculations of long-lived isomer production in neutron reactions  

Energy Technology Data Exchange (ETDEWEB)

We have carried out theoretical calculations for the production of the long-lived isomers {sup 93m}Nb({1/2}{sup {minus}}, 16y), {sup 121m}Sn(11/2{minus}, 55 yr), {sup 166m}Ho(7-, 1200 yr), {sup 184m}Re(8+, 165 d), {sup 186m}Re(8+, 2{times}10{sup 5} yr), {sup 178m}Hf(16+, 31 yr), {sup 179m}Hf(25/2-, 25 d), {sup 192m}Ir(9+, 241 yr), all of which pose potential radiation activation problems in nuclear fusion reactors. We consider (n, 2n), (n,n{prime}), and (n, {gamma}) production modes and compare our results both with experimental data (where available) and systematic. We also investigate the dependence of the isomeric cross section ratio on incident neutron energy for the isomers under consideration. The statistical Hauser-Feshbach plus preequilibrium code GNASH was used for the calculations. Where discrete state experimental information was lacking, rotational band members above the isomeric state, which can be justified theoretically but have ...

1991-01-01

203

Design of advanced automotive exhaust catalysts  

Energy Technology Data Exchange (ETDEWEB)

Rhodium (Rh) is a critical component of current automotive three-way catalysts (TWCs), particularly with regard to NO{sub x} and CO conversion at rich and stoichiometric air-fuel ratios (A/F). Rh supported on CeO{sub 2} was active for NO{sub x} and CO conversions but could be deactivated easily by high temperature aging. The cause of the deactivation is ascribed to the sintering of CeO{sub 2}. ZrO{sub 2} incorporation into CeO{sub 2} is reported to have high thermal durability in terms of oxygen storage capacity (OSC). There has been no report showing direct experimental evidence that Rh-loaded on CeO{sub 2}-ZrO{sub 2} mixed oxides induced effects on TWC performance improvement in the actual automotive exhaust. In the present paper, the Rh-CeO{sub 2} interaction contributing to NO{sub x} reduction and the catalytic behavior of Rh-loaded CeO{sub 2}-ZrO{sub 2} mixed oxide is addressed. Incorporating CeO{sub ...

2000-12-25

204

Anodic protection provided by precipitates in aqueous corrosion of Zircaloy  

Energy Technology Data Exchange (ETDEWEB)

Alloying elements such as Fe and Cr are generally considered to be effective even in small quantities for corrosion resistance of Zircaloy-4. The maximum total solubility of Fe + Cr in a Zr-Sn matrix has been reported to be very low. Therefore, most of these elements are observed in the form of ternary Zr-Fe-Cr-type precipitates. To clarify the effects of precipitates on corrosion property, Zr-1.3 Sn-(Fe,Cr) alloys containing Fe + Cr from 45 up to 180 ppm (the Fe to Cr ratio is about 2) were melted from pure zirconium (X-bar Zr and EB-Zr) and pure alloying elements. They were subjected to corrosion testing in 633 K water and microstructural analysis. It was found that precipitate-free materials showed much larger weight gains than precipitate-containing materials even at the same alloy compositions. Subsequently, a corrosion test on the precipitate-free material galvanically coupled ...

1996-12-31

205

Anodic protection provided by precipitates in aqueous corrosion of Zircaloy  

International Nuclear Information System (INIS)

Alloying elements such as Fe and Cr are generally considered to be effective even in small quantities for corrosion resistance of Zircaloy-4. The maximum total solubility of Fe + Cr in a Zr-Sn matrix has been reported to be very low. Therefore, most of these elements are observed in the form of ternary Zr-Fe-Cr-type precipitates. To clarify the effects of precipitates on corrosion property, Zr-1.3 Sn-(Fe,Cr) alloys containing Fe + Cr from 45 up to 180 ppm (the Fe to Cr ratio is about 2) were melted from pure zirconium (X-bar Zr and EB-Zr) and pure alloying elements. They were subjected to corrosion testing in 633 K water and microstructural analysis. It was found that precipitate-free materials showed much larger weight gains than precipitate-containing materials even at the same alloy compositions. Subsequently, a corrosion test on the precipitate-free material galvanically coupled ...

1995-09-11

206

Ten-nanometer surface intrusions in room temperature silicon  

CERN Document Server

Defects ~10 nm in size, with number densities ~10^{10} cm^{-2}, form spontaneously beneath ion-milled, etched, or HF-dipped silicon surfaces examined in our Ti-ion getter-pumped transmission electron microscope (TEM) after exposure to air. They appear as weakly-strained non-crystalline intrusions into silicon bulk, that show up best in the TEM under conditions of strong edge or bend contrast. If ambient air exposure is <10 minutes, defect nucleation and growth can be monitored {\\em in situ}. Possible mechanisms of formation are discussed.

2002-01-01

207

Simple method for high-temperature separation of thallium isotopes from a bulk lead target  

Energy Technology Data Exchange (ETDEWEB)

A method is proposed for the quantitative isolation of radiothallium in gas form from proton-bombarded lead of mass up to 20 g. The molten lead is kept at about 800 K in hydrofluoric-acid vapor (HF/H/sub 2/O approx. = 1) at a reduced pressure (less than or equal to4 Pa). We used 99.9% lead with the U-240 cyclotron at the Nuclear Research Institute, Academy of Sciences of the Ukrainian SSR, or the phasotron at the Join Nuclear Research Institute, which gave protons at 65 and 680 MeV correspondingly.

1988-03-01

208

Simple method for high-temperature separation of thallium isotopes from a bulk lead target  

International Nuclear Information System (INIS)

A method is proposed for the quantitative isolation of radiothallium in gas form from proton-bombarded lead of mass up to 20 g. The molten lead is kept at about 800 K in hydrofluoric-acid vapor (HF/H_2O #approx =# 1) at a reduced pressure (#<=#4 Pa). We used 99.9% lead with the U-240 cyclotron at the Nuclear Research Institute, Academy of Sciences of the Ukrainian SSR, or the phasotron at the Join Nuclear Research Institute, which gave protons at 65 and 680 MeV correspondingly.

209

Plasma Dynamics in the Vicinity of the Local Plasma resonance Point Excited by Pumping Electric Field or Modulated Electron Beam  

International Nuclear Information System (INIS)

Excitation of the HF electric field in the local plasma resonance region (LPRR) of inhomogeneous plasma by pumping electric field or modulated electron beam results to appearance of the ponderomotive force that presses plasma out of this region. Density cavity is formed in the LPRR due to this field. Further dynamics in this region depends on the plasma properties. For plasma with hot electrons ion-acoustic pulses run away from the cavity. at the local density maximum the new peak of electric field is excited. It results to the formation of new density cavity, etc. For isothermal plasma the density jump is formed.

2006-01-01

210

Nuclear spectroscopy, ch. 8  

International Nuclear Information System (INIS)

Energy level schemes are derived from gamma spectroscopy of several medium-mass deformed nuclei by studying the decay or proton and #alpha# nuclear spectroscopic data. Some new isomeric studies are established among which is the 31 y "1"7"8Hf isomeric state for which Isup(#pi#), K was determined to be 16"+, 16. A four quasi-particle configuration was assigned to this state at 2447.5 +- 2.5 KeV. Atomic masses have been calculated from various measurements and, on the basis of mass formulae extrapolated to neighboring mass regions.

211

Nuclear magnetic resonance on oriented XVTa and XXTa  

Energy Technology Data Exchange (ETDEWEB)

XVTa and XXTa nuclei were oriented at low temperature as dilute impurities in Fe. The magnetic hyperfine splitting frequencies = B sub(HF)/Ih of the XVTa and XXTa ground states have been measured to be 320.45(11) and 317.552(55) MHz by using the technique of NMR-ON. Taking the known hyperfine field of Y Ta in Fe, the magnetic moments have been deduced: ( XVTa, 7/2 ) =2.270(45) and ( XXTa, 7/2 ) =2.250(45) sub(N). These values of the magnetic moments are discussed in the framework of the rotational model.

1984-08-01

212

The Growth of an Extrapancreatic Solid Pseudopapillary Tumor from the Greater Omentum: A Case Report  

Energy Technology Data Exchange (ETDEWEB)

A solid pseudopapillary tumor is an uncommon tumor of the pancreas that rarely metastasizes to other organs and usually shows good prognosis. An extrapancreatic tumor arising from a solid pseudopapillary tumor is very rare. We report a case of an atypical extrapancreatic solid pseudopapillary tumor that arose from the great omentum and disseminated to the peritoneum, and discuss the radiologic findings, including the CT, US, and MRI.

2010-01-15

213

The Growth of an Extrapancreatic Solid Pseudopapillary Tumor from the Greater Omentum: A Case Report  

International Nuclear Information System (INIS)

A solid pseudopapillary tumor is an uncommon tumor of the pancreas that rarely metastasizes to other organs and usually shows good prognosis. An extrapancreatic tumor arising from a solid pseudopapillary tumor is very rare. We report a case of an atypical extrapancreatic solid pseudopapillary tumor that arose from the great omentum and disseminated to the peritoneum, and discuss the radiologic findings, including the CT, US, and MRI

2010-01-01

214

Rare & Scarce Plants of Lowland Grassland  

Environmental Research Database

DescriptionM291272: Annex A: Project specification Introduction Lowland grassland habitats host a wide range of rare, scarce and declining flowering plants, some of which are afforded protection under UK and EU legislation, as well as qualifying for Red Data lists and Biodiversity Action Plan priority lists. Other scarce species while not qualifying for the above designations are still of conservation significance and should help inform our priorities for lowland grassland habitat management. At prese [continued...

215

Potent immune responses and in vitro pro-inflammatory cytokine suppression by a novel adenovirus vaccine vector based on rare human serotype 28  

UK PubMed Central (United Kingdom)

Adenovirus vaccine vectors derived from rare human serotypes have been shown to be less potent than serotype 5 (Ad5) at inducing immune responses to encoded antigens. To identify highly immunogenic...Full Text Available

2010-08-09

216

Magnetic properties of heavy rare-earth tungstates  

International Nuclear Information System (INIS)

Measurement of the magnetic susceptibility of powder samples of heavy rare-earth (Tb, Dy, Ho, Er, Tm and Yb) tungstates have been reported in the temperature range 300 to 900 K. Curie-Weiss law behaviour has been observed for all samples. The Curie constant, paramagnetic Curie temperature and magneton number for the magnetic ions have also been evaluated for each material. (author).

1978-12-01

217

Klippel-feil syndrome with situs inversus. A rare association  

International Nuclear Information System (INIS)

Klippel-Feil Syndrome (KFS) is a congenital anomaly characterized by a defect in the formation or segmentation of the cervical vertebrae. The clinical triad consists of short neck, low posterior hairline and limited neck movement. Multiple congenital anomalies have been associated with this disease. This is a case of KFS in a young girl along with situs inversus, which is an extremely rare association. Various systemic associations occurring in this multi-system disorder are also discussed. (author)

2008-04-01

218

Wet chemical etch solutions for Al{sub x}Ga{sub 1{minus}x}P  

Science.gov (United States)

Heterostructures based on AlGaInP alloy compounds are very attractive for visible semiconductor lasers, heterojunction bipolar transistors (HBTs), and high-electron-mobility transistors (HEMTs) lattice matched to GaAs substrates. Several wet etching solutions for AlGaP of different compositions have been studied. Al{sub 0.5}Ga{sub 0.5}P is found to etch in HF, H{sub 3}PO{sub 4}, hyphosphorous acid (HOPH{sub 2}:O), HCl, KOH, and 1% Br{sub 2}-methanol (MeOH). Etching of Al{sub 0.5}Ga{sub 0.5}P in HCl is reaction limited with an activation energy of {approximately}54.4 kJ/mol. At fixed conditions, the etch rates of Al{sub x}Ga{sub 1{minus}x}P vary exponentially with x in HF and HCl, while in 1% Br{sub 2}-MeOH and mixtures of HCl and HNO{sub 3} the etch rates follow a linear dependence on AlP mole fraction. HF has been found to be a good etchant for AlGaP over InGaP or AlInP with high selectivity, while HCl is useful for the ...

1996-01-01

219

The characteristics of surface oxidation and corrosion resistance of nitrogen implanted zircaloy-4  

International Nuclear Information System (INIS)

This work is concerned with the development and application of ion implantation techniques for improving the corrosion resistance of zircaloy-4. The corrosion resistance in nitrogen implanted zircaloy-4 under a 120 keV nitrogen ion beam at an ion dose of 3 x 10"1"7 cm"-"2 depends on the implantation temperature. The characteristics of surface oxidation and corrosion resistance were analyzed with the change of implantation temperature. It is shown that as implantation temperature rises from 100 to 724 C, the colour of specimen surface changes from its original colour to light yellow at 100 C, golden at 175 C, pink at 300 C, blue at 440 C and dark blue at 550 C. As the implantation temperature goes above 640 C, the colour of surface changes to light black, and the surface becomes a little rough. The corrosion resistance of zircaloy-4 implanted with nitrogen is sensitive to the implantation temperature. The pitting potential of specimens increases from 176 to 900 mV (SCE) as the ...

220

Growth characteristics of ZrO_2 insulation coatings on Ag/AgMg sheathed Bi-2212 superconducting tapes  

International Nuclear Information System (INIS)

We have investigated the growth behaviors of high temperature compatible ZrO_2 insulation coatings on Ag and AgMg sheathed Bi_2Sr_2Ca_1Cu_2O_x superconducting tapes depending on number of dipping and thermal conditions. The coatings were fabricated on long-length superconducting tape substrates using a solution derived from Zr tetrabutoxide, solvent and chelating agent for high magnetic field magnets. The layer-on-layer growth behaviors were characterized by environmental scanning electron microscope (ESEM), energy dispersive spectroscopy (EDS), X-ray maps and X-ray diffraction (XRD). This research showed that the ZrO_2 coatings were regularly grown on Ag-based tape substrates and coating thickness increased with increasing number of dipping. It was found that ceramic oxides formed at temperature range 450 and 550 deg. C. The final coating thickness changed between 6 and 8 #mu#m after annealing process. Resistance of ...

2004-07-15

221

Coincidence study of alpha particle fragmentation at E/sub alpha/ = 140 MeV  

Energy Technology Data Exchange (ETDEWEB)

Results of an experimental study of the interaction of 140 MeV alpha particles with /sup 90/Zr nuclei resulting in fragmentation of the alpha particle are reported. The experimental observations of the study are analyzed and are found to show that alpha particle breakup reactions leading to at least 4-body final states, composed of two charged alpha particle fragments, contribute significantly to the singles yield of charged fragments observed at a fixed forward angle. The conclusions are based on coincidence measurements where one charged fragment is detected at a small forward angle which remains fixed, while the second charged fragment is detected at a series of coplanar secondary angles. The largest coincidence charged particle yield for the multiparticle final state events results from /sup 90/Zr(..cap alpha..,pp)X reactions, where both of the measured protons have energy distributions similar to the proton singles energy distributions. ...

1980-01-01

222

Coincidence study of alpha particle fragmentation at E/sub alpha/ = 140 MeV  

International Nuclear Information System (INIS)

Results of an experimental study of the interaction of 140 MeV alpha particles with _9_0Zr nuclei resulting in fragmentation of the alpha particle are reported. The experimental observations of the study are analyzed and are found to show that alpha particle breakup reactions leading to at least 4-body final states, composed of two charged alpha particle fragments, contribute significantly to the singles yield of charged fragments observed at a fixed forward angle. The conclusions are based on coincidence measurements where one charged fragment is detected at a small forward angle which remains fixed, while the second charged fragment is detected at a series of coplanar secondary angles. The largest coincidence charged particle yield for the multiparticle final state events results from _9_0Zr(#alpha#,pp)X reactions, where both of the measured protons have energy distributions similar to the proton singles energy distributions. The second ...

223

Towards atomic scale engineering of rare-earth-doped SiAlON ceramics through aberration-corrected scanning transmission electron microscopy  

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.

2011-01-01

224

Production of rare-earth atomic negative ion beams in a cesium-sputter-type negative ion source  

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.

2007-08-01

225

Paramagnetic properties of the RCo_2 compounds (R = rare earth)  

International Nuclear Information System (INIS)

The paramagnetic susceptibilities of all the RCo_2 compounds for which measurements are available are found to obey a Curie-Weiss law consistent with the modified indirect exchange model. The rare-earth ions are in a well defined tripositive valence state. Paramagnetic moments and paramagnetic Curie temperatures are obtained for these materials for the first time. The paramagnetic moments of these materials are changed from their free-ion values by the effects of itinerant electron polarisation, an effect which is particularly large for SmCo_2 whose paramagnetic moment is almost three times greater than the free-ion value. The modified indirect exchange model is found to be able to give a full description of the magnitude of the rare-earth, cobalt and diffuse moments in polarised neutron experiments. The band structures of the light RCo_2 compounds are found to be distinctly different to those of the heavy RCo_2 compounds. (author).

1984-03-01

226

Interaction of rare earths with orthanyl K and its spectrophotometric determination in binary mixtures  

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).

1975-01-01

227

Abces du muscle iliopsoas : complication rare de la sacro-iliite a pyogene chez lenfant  

British Library Electronic Table of Contents (United Kingdom)

Pyogenic sacroiliitis is a rare entity in children. Diagnosis is often delayed because of its variable clinical presentation, low suspicion by the examining physician, and rare findings on radiographs. Delayed diagnosis, however, results in complications such as iliopsoas abscess. We report the case of a 12-year-old girl hospitalized with a 21-day history of fever, pain in the left iliac fossa, and flexion contracture of the hip. On examination, she had fever (38.9 ^oC), psoitis, localized tenderness at the left sacroiliac joint, and pain elicited by lateral compression of the pelvis. The abdominal examination was normal. The erythrocyte sedimentation rate was 130mm in the first hour, C-reactive protein was 186mg/l, and the white blood cell count was 18,400/mm^3, with 79% neutrophils. Urin...

2010-01-01

228

Transesterification of palm oil and esterification of palm fatty acid in near- and super-critical methanol with SO4-ZrO2 catalysts  

British Library Electronic Table of Contents (United Kingdom)

Sulfated zirconia (SO4-ZrO2) catalysts, prepared with three different sulfur loading contents (0.75%, 1.8% and 2.5%) at two calcination temperatures (500degreeC and 700degreeC), were tested for use in the transesterification of purified palm oil (PPO) and the esterification of palm fatty acid (PFA) in near-critical and super-critical methanol. Techniques including BET, XRD, NH3- and CO2-TPD revealed that the sulfur content and calcination temperature strongly affects the catalyst base-acid site, specific surface area, average pore size, phase structure, and thus the catalytic reactivity. The most suitable sulfur loading content was found to be 1.8% and the optimum calcination temperature 500degreeC. The results show that the use of SO4-ZrO2 reduces esterification reaction times, the amount...

2010-01-01

229

Preparation of ZrO_2/O'-sialon composites using dissociation of zircon  

International Nuclear Information System (INIS)

ZrO_2/O'-sialon composites were obtained via reaction sintering of ZrSiO_4 and Si_3N_4 powders at about 1700 deg C. Y_2O_3 was effective in both stabilizing of zirconia and densifying the composites. However, it is not easy to select an optimum value of the single additive to balance these two requirements simultaneously. With low Y_2O_3 addition, some tetragonal zirconia grains in the sintered samples are transformable during mechanical grinding but the full densification of the material is then sacrificed. On the other hand, addition more Y_2O_3 to achieve complete densification results in the zirconia being stabilized into undesirable t' or cubic forms. Therefore no improved toughening effects have been achieved in the composites. Heat-treatment of the materials at 1400 deg C. results in the diffusion of yttria from the grain boundary phase to zirconia and the formation of the O'-cubic zirconia composite may still provide a useful refractory ...

230

Nanocrystallization of soft magnetic Fe-Co-Zr-Cu-B alloys  

International Nuclear Information System (INIS)

In the present study, Fe_4_1Co_4_1 B_1_0Zr_7Cu_1 alloy has been investigated in order to evaluate its thermal stability and structure after heat treatment, as well as the impact of heat treatment on magnetic properties. X-ray diffractometry, differential scanning calorimetry, chemical composition microanalysis, transmission electron microscopy, and magnetic hysteresis loop measurement techniques were employed. The crystallization temperature of the as-quenched alloy is 490"oC (continuous heating at 5 "oC/min). The melt spun ribbon having 27 #mu#m in thickness was annealed for 1 hour at temperatures from 400 to 700 "oC. The alloy after treatment at about 550"oC underwent primary crystallization, with the average size of crystals under 20 nm. This specimen shows the coercive field of 38 A/m, as compared to about 160 A/m reported for a similar alloy (Fe_4_4Co_4_4B_4Zr_7Cu_1) with a similar structure, annealed at 600"oC. (author)

2001-09-23

231

Manufacturing method of zirconium alloy structural material for reactor core having excellent corrosion resistance, especially, uniform corrosion resistance and hydrogen absorption resistance  

International Nuclear Information System (INIS)

The corrosion resistance of zircaloy is affected by conditions of heat treatment in the manufacturing steps to be formed into a final product as a structural material. In the manufacturing method of the present invention, a Zr alloy controlled to contain Sn: 0.8 to 1.2wt%, Fe: 0.17 to 0.28wt%, Cr: 0.05 to 0.15wt%, Ni: 0.04 to 0.10wt%, Nb: 0.01 to 0.09wt%, oxygen: 1,000 to 1,500ppm and Si, an Si impurity at a concentration of 120ppm or less and balance of Zr is melted into a cast piece, to which #beta# hardening is applied. Then, rolling and annealing treatment are applied so that the total heat input amount to the material: #SIGMA#Ai ranges from 1 x 10"-"1"9 to 1 x 10"-"1"7. With such procedures, a Zr alloy structural material for a reactor core having excellent homogeneous corrosion resistance and hydrogen absorption resistance for a long period of time while having a sufficient strength can be obtained even in a case ...

1997-01-17

232

Influence of the substrate coating temperature on the vacuum properties of Ti-Zr-V non-evaporable getter films  

CERN Document Server

Non-evaporable thin film getters of various compositions have been produced by sputtering. Among about 20 materials which have been studied, the lowest activation temperature (about 180 degree C) has been displayed by a Ti-Zr-V coating obtained from a cathode made of intertwisted elemental wires. In order to optimize the vacuum properties of this film various production parameters, including the substrate temperature during coating, have been varied. The films have been characterized by pumping speed measurement, secondary electron microscopy, and X-ray diffraction. It has been found that the substrate coating temperature affects significantly the activation temperature, the pumping speed and the gas surface capacity. The highest pumping speed values, obtained for substrate coating temperatures of 250 degree C and 300 degree C, are clearly correlated with the increased surface roughness and porosity of the Ti-Zr-V film.

2003-01-01

233

Application of radionuclide X-ray fluorescence analysis to the monitoring of the quality of air  

International Nuclear Information System (INIS)

An X-ray fluorometric train was set up for analyzing gravitational fallout, and tested on standard reference samples of fly ashes from conventional power plants. Analysis of thin layers proved inappropriate, and therefore pelletization of the samples, either alone or together with the X-ray MIX binder, was applied. Sample grinding in an agate mortar was found sufficient to suppress the particle size effect. The optimum pressure was 20 MPa. The optimum geometry was sought for "1"0"9Cd source, and limits of detection of 2.78-0.47 #mu#g were achieved for Cr-Zr elements. Tominaga's method was employed for matrix effect correction. Ti, Fe, Cu, Zn, As, Rb, Sr, Zr and Pb were determined in the SRM's; the relative errors ranged from units per cent (for Zn, Rb, Sr and Zr present in concentrations about 100 ppm and for Fe in concentrations of units per cent) up to 45% (for Ti present in a concentration of 0.67%). The method developed ...

1990-10-01

234

Y-type urethral duplication presented with perineal fistula in a boy  

UK PubMed Central (United Kingdom)

Urethral duplication is a rare congenital anomaly of the lower urinary system and has varied presentation. According to the Effmann classification, type IIA2-Y urethral duplication is charcterized by...Full Text Available

235

Walled-off pancreatic necrosis  

UK PubMed Central (United Kingdom)

Walled-off pancreatic necrosis (WOPN), formerly known as pancreatic abscess is a late complication of acute pancreatitis. It can be lethal, even though it is rare. This critical review provides an overview...Full Text Available

2010-04-14

236

Virilizing Adrenocortical Oncocytoma in a Child: A Case Report  

UK PubMed Central (United Kingdom)

Functioning adrenocortical oncocytomas are extremely rare and most reported patients are 40-60 yr of age. To our knowledge, only 2 cases of functioning adrenocortical oncocytomas have been reported...Full Text Available

2010-07-01

237

Treatment of early uterine sarcomas: disentangling adjuvant modalities  

UK PubMed Central (United Kingdom)

Uterine sarcomas are a rare group of neoplasms with aggressive clinical course and poor prognosis. They are classified into four main histological subtypes in order of decreasing incidence: carcinosarcomas,...Full Text Available

238

Traumatic bronchial rupture: an unusual cause of tension pneumothorax  

UK PubMed Central (United Kingdom)

Bronchial rupture is a rare and serious complication of blunt chest trauma, which can be easily overlooked on initial evaluation in the emergency room (ER) as the focus of the attending physician is...Full Text Available

239

The Role of an Online Community for People With a Rare Disease: Content Analysis of Messages Posted on a Primary Biliary Cirrhosis Mailinglist  

UK PubMed Central (United Kingdom)

BackgroundThis study focuses on the role of an Internet-based group for people who have an autoimmune liver disease, primary biliary cirrhosis. Primary biliary...Full Text Available

240

Tension pneumothorax in a newborn after Cesarean-section delivery -A case report-  

UK PubMed Central (United Kingdom)

Tension pneumothorax in newborns is a rare but life-threatening complication. We encountered a case of a full-term neonate with a breech presentation. An elective cesarean section was scheduled. Immediately...Full Text Available

2010-12-01

241

Surgical Management of Solid-Pseudopapillary Neoplasms of the Pancreas (Franz or Hamoudi Tumors): A Large Single-Institutional Series  

UK PubMed Central (United Kingdom)

BACKGROUNDSolid-pseudopapillary neoplasms (SPNs) are rare pancreatic tumors with malignant potential. Clinicopathologic characteristics and outcomes of patients with...Full Text Available

2009-05-01

242

Subtle Radiological Features of Splenic Avulsion following Abdominal Trauma  

UK PubMed Central (United Kingdom)

Splenic trauma in children following blunt abdominal injury is usually treated by nonoperative management (NOM). Splenectomy following abdominal trauma is rare in children. NOM is successful as in the...Full Text Available

2010-01-01

243

Spontaneous cervical epidural hematoma: Report of a case managed conservatively  

UK PubMed Central (United Kingdom)

Spontaneous spinal epidural hematoma is a rare cause of acute spinal cord compression. A 25-year-old male presented with a history of sudden onset of complete quadriplegia with sensory loss below the...Full Text Available

2008-07-01

244

Spindle cell carcinoma of head and neck: an immunohistochemical and molecular approach to its pathogenesis  

UK PubMed Central (United Kingdom)

BackgroundSpindle cell carcinoma (SpCC) is a rare microscopic type of cancer of the mouth and oropharynx. Although SpCC is thought to arise from squamous cell carcinoma (SCC), it...Full Text Available

2007-05-01

245

Sparganosis in the Lumbar Spine : Report of Two Cases and Review of the Literature  

UK PubMed Central (United Kingdom)

Sparganosis is a rare parasitic infection affecting various organs, including the central nervous system, especially the lumbar epidural space. This report describes the identification of disease and...Full Text Available

2011-04-01

246

Some open questions in nuclear physics  

Energy Technology Data Exchange (ETDEWEB)

A review of recent work in nuclear physics is presented. The paper gives a broad discussion of research goals in nuclear structure, quark-gluon degrees of freedom, quark-gluon plasma, symmetries, and rare decays. (DWL)

1986-10-01

247

Sexual maturity in growing dinosaurs does not fit reptilian growth models  

UK PubMed Central (United Kingdom)

Recent histological studies suggest relatively rapid growth in dinosaurs. However, the timing of reproductive maturity (RM) in dinosaurs is poorly known because unambiguous indicators of RM are rare....Full Text Available

2008-01-15

248

Serratia odorifera biogroup 1 causing an invasive human infection.  

UK PubMed Central (United Kingdom)

Serratia odorifera biogroup 1 was isolated from the blood and urine of an alcoholic male with cirrhosis and signs of septic shock. The organism is rarely reported to occur in clinical specimens. This...Full Text Available

1988-06-01

249

Scalp Angiosarcoma Remission with Bevacizumab and Radiotherapy without Surgery: A Case Report and Review of the Literature  

UK PubMed Central (United Kingdom)

Angiosarcoma (AS) is a rare and aggressive vascular neoplasm with very poor prognosis. Patients with extensive cutaneous AS who are not surgical candidates have very limited options since there is no...Full Text Available

2011-01-01

250

Role of Conserved Salt Bridges in Homeodomain Stability and DNA Binding*  

UK PubMed Central (United Kingdom)

The sequence information available for homeodomains reveals that salt bridges connecting pairs 19/30, 31/42, and 17/52 are frequent, whereas aliphatic residues at these sites are rare and mainly restricted...Full Text Available

2009-08-28

251

Rare mutations predisposing to familial adenomatous polyposis in Greek FAP patients  

UK PubMed Central (United Kingdom)

BackgroundFamilial Adenomatous Polyposis (FAP) is caused by germline mutations in the APC (Adenomatous Polyposis Coli) gene. The vast majority of APC mutations...Full Text Available

252

Rare Homologous Gene Targeting in Histoplasma capsulatum: Disruption of the URA5Hc Gene by Allelic Replacement  

UK PubMed Central (United Kingdom)

URA5 genes encode orotidine-5′-monophosphate pyrophosphorylase (OMPpase), an enzyme involved in pyrimidine biosynthesis. We cloned the Histoplasma capsulatum URA5...Full Text Available

1998-10-01

253

Radioanalytical methods of rare earth element determination  

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. ...

1989-06-01

254

Pyogenic abscess of the PSOAS - Description of cases registered in the university hospital of the valley  

International Nuclear Information System (INIS)

In this chart review the authors describe 51 cases of PSOAS abscess treated at Hospital Universitario del Valle in Cali, Colombia in the last 10 years. It is not a rare condition and require high index of suspicion. epidemiology, bacteriology, diagnosis and treatment are discussed.

2006-06-01

255

Properties of rare-gas solids. [Diffusion rate of xenon through epithelial tissue  

Science.gov (United States)

Results are reported from studies of the diffusion rate of xenon through frog abdominal skin and toad urinary bladders, typical epithelial membranes. It was concluded that intracellular water serves as the principal barrier for xenon passage through epithelial tissue.

1977-01-01

256

Problematic renal calculi presenting during pregnancy.  

UK PubMed Central (United Kingdom)

Urinary tract calculi presenting during pregnancy are rare, with less than 0.1% of pregnancies being associated with stones, the vast majority being asymptomatic and a chance finding. We outline six...Full Text Available

1996-03-01

257

Prevention and control of haemophilia: memorandum from a joint WHO/WFH meeting (World Federation of Haemophilia)  

UK PubMed Central (United Kingdom)

Haemophilia, the commonest hereditary bleeding disorder, arises because of the absence of, decrease in, or deficient functioning of plasma coagulation factor VIII or factor IX. With rare exceptions,...Full Text Available

1991-01-01

258

Predicting Airborne Particle Levels Aboard Washington State School Buses  

UK PubMed Central (United Kingdom)

School buses contribute substantially to childhood air pollution exposures yet they are rarely quantified in epidemiology studies. This paper characterizes fine particulate matter (PM2.5)...Full Text Available

2008-10-01

259

Pericardiectomy for Pleuropericardial Effusion Complicating Bacterial Pneumonia  

UK PubMed Central (United Kingdom)

Severe pericardial effusion is a rare complication of bacterial pneumonia and it usually disappears under medical treatment. Herein we report a case of a girl with a congenital immunodeficient syndrome...Full Text Available

2010-01-01

260

Percutaneous Management of a Long Saphenous Vein Graft Aneurysm: A Case Report and Review of Literature  

UK PubMed Central (United Kingdom)

Aneurysms of saphenous vein grafts are rare but can result in complications such as myocardial infarction or death. Percutaneous treatment has included a variety of approaches, including covered stents....Full Text Available

2009-01-01

261

Paleoecological Implications of Differential Biomass and Litter Production in Canopy Trees in Australian Nothofagus and ...  

Science.gov (United States)

... be rare or absent as leaves in the forest litter. The differences between the amount of leaf and ... the relative proportions of leaf species in a forest litter when compared with standing biomass has sig...

262

PAGETOID RETICULOSIS IN A 5 YEAR OLD BOY  

UK PubMed Central (United Kingdom)

We present a rare case of pagetoid reticulosis arising in a five year old white boy. He had a history of a large chronic erythematous, scaly patch on his left buttock that had shown intermittent...Full Text Available

2008-04-01

263

Osteoid osteoma near the intervertebral foramen may induce radiculopathy through tumorous inflammation  

UK PubMed Central (United Kingdom)

Osteoid osteoma of the spine is a relatively rare bone-forming tumor. Pain that is worse at night and relieved by aspirin and muscle contracture are the most characteristic symptoms of spinal osteoid...Full Text Available

264

Osteogenic sarcoma of the breast arising in a cystosarcoma phyllodes: a case report and review of the literature  

UK PubMed Central (United Kingdom)

IntroductionPrimary tumors of the breast containing bone and cartilage are extremely rare, and an osteogenic sarcoma arising from a cystosarcoma phyllodes is exceptional.Case...Full Text Available

265

Optical properties of rare earth sodium double molybdates Na[sub 5]RE(MoO[sub 4])[sub 4], RE=Pr, Nd, Eu  

Energy Technology Data Exchange (ETDEWEB)

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 earth, when compared with those determined previously for Eu[sup 3+] in the ...

1994-06-01

266

Myelomatous Pleural Effusion: A Case Series in a Single Institution and Literature Review  

UK PubMed Central (United Kingdom)

BackgroundMyelomatous pleural effusion (MPE) is rare in myeloma patients. We present a consecutive series of patients with MPE in a single institution.MethodsWe...Full Text Available

2011-10-01

267

Molecular Mapping of Movement-Associated Areas in the Avian Brain: A Motor Theory for Vocal Learning Origin  

UK PubMed Central (United Kingdom)

Vocal learning is a critical behavioral substrate for spoken human language. It is a rare trait found in three distantly related groups of birds-songbirds, hummingbirds, and parrots. These avian groups...Full Text Available

268

Massive Concha Bullosa with Secondary Maxillary Sinusitis  

UK PubMed Central (United Kingdom)

Concha bullosa is a common anatomic variation of the middle turbinate; however, sinusitis secondary to the concha bullosa is rare. A 52-yr-old woman presented with nasal obstruction and posterior nasal...Full Text Available

2008-12-01

269

Malignant pineal germ-cell tumors: An analysis of cases from three tumor registries  

UK PubMed Central (United Kingdom)

The exact incidence of pineal germ-cell tumors is largely unknown. The tumors are rare, and the number of patients with these tumors, as reported in clinical series, has been limited. The goal of this...Full Text Available

2008-04-01

270

Malfunction of a Heimlich flutter valve causing tension pneumothorax: case report of a rare complication  

UK PubMed Central (United Kingdom)

BackgroundThoracic injuries play an important role in major trauma patients due to their high incidence and critical relevance. A serious consequence of thoracic trauma is pneumothorax,...Full Text Available

271

Magnetic excitations studied with time-of-flight spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

An introduction to time-of-flight neutron spectroscopy is presented in the context of the study of magnetic materials. Examples are taken from the class of rare earth and actinide magnetic materials known as `strongly correlated electron` systems. (author) 11 figs., 24 refs.

1996-11-01

272

Latent Tricuspid Valve Rupture after Motor Vehicle Accident and Routine Echocardiography in All Chest-Wall Traumas  

UK PubMed Central (United Kingdom)

Blunt chest-wall trauma is common; however, resultant tricuspid valve rupture is rare and can be subtle in its presentation. Transthoracic echocardiography plays a key role in diagnosis.Herein,...Full Text Available

2009-01-01

273

Investigation and management of adrenal disease  

British Library Electronic Table of Contents (United Kingdom)

Disorders of the adrenal gland are rare and complex, with many potential pitfalls in their management. An understanding of embryology, anatomy, physiology and biochemistry is crucial. Surgical treatment may be required for syndromes of hormonal excess and/or suspicion of neoplasia.

2011-01-01

274

Inflammatory Bowel Disease in Children, an Evolving Problem in Kuwait  

UK PubMed Central (United Kingdom)

Background/Aims:Inflammatory bowel disease (IBD) was previously thought a rare disease among children in Kuwait since most diarrhea cases were attributed to infections....Full Text Available

2011-09-01

275

Ichthyosis follicularis, alopecia, and photophobia (IFAP) syndrome  

UK PubMed Central (United Kingdom)

The IFAP syndrome is a rare X-linked genetic disorder reported in nearly 40 patients. It is characterized by the triad of Ichthyosis Follicularis, Alopecia, and Photophobia from birth. Other features...Full Text Available

276

Iatrogenic post-intubation tracheal rupture treated conservatively without intubation: a case report  

UK PubMed Central (United Kingdom)

BackgroundTracheal rupture is a rare but life-threatening complication that most commonly occurrs after blunt trauma to the chest, but which may also complicate tracheal intubation....Full Text Available

277

Hemangiopericytomas of the spine: case report and review of the literature  

UK PubMed Central (United Kingdom)

We describe a rare case of a primary intracranial meningeal hemangiopericytoma (HPC) with late metastasis to the cervical spine. A 36-year-old woman had a left occipital lesion that was histopathologically...Full Text Available

278

Health professionals rarely record history of complementary and alternative medicines  

UK PubMed Central (United Kingdom)

AimsTo identify the completeness of documentation of Complementary And Alternative Medicine (CAM) use in hospital medical records of patients before and after an education programme.Full Text Available

2005-02-01

279

Guidelines on exchangers  

Energy Technology Data Exchange (ETDEWEB)

Experience has shown that a list of tips provides designers and engineers with an effective guide in their areas of duties and concern. This list contains new and rare information on heat exchangers and heat recovery systems. The information presented can be used effectively with personal computers and pocket calculators and also conveniently translated into computer programs and nomographs.

1985-08-01

280

Genomic Evidence for the Evolution of Streptococcus equi: Host Restriction, Increased Virulence, and Genetic Exchange with Human Pathogens  

UK PubMed Central (United Kingdom)

The continued evolution of bacterial pathogens has major implications for both human and animal disease, but the exchange of genetic material between host-restricted pathogens is rarely considered....Full Text Available

2009-03-01

281

Four Cases of a Cerebral Air Embolism Complicating a Percutaneous Transthoracic Needle Biopsy  

UK PubMed Central (United Kingdom)

A percutaneous transthoracic needle biopsy is a common procedure in the practice of pulmonology. An air embolism is a rare but potentially fatal complication of a percutaneous transthoracic needle biopsy....Full Text Available

2009-01-01

282

First Culture Isolation of Borrelia lonestari, Putative Agent of Southern Tick-Associated Rash Illness  

UK PubMed Central (United Kingdom)

Southern tick-associated rash illness (STARI) is a Lyme disease-like infection described in patients in the southeastern and south-central United States, where classic Lyme disease is relatively rare....Full Text Available

2004-03-01

283

Familial premature ovarian failure.  

UK PubMed Central (United Kingdom)

Premature menopause, ovarian failure younger than 40 years of age, is relatively rare but may preclude childbearing for some women who delay attempts at fertility. We present five kindreds in which...Full Text Available

1984-11-01

284

Evidence for modular evolution in a long-tailed pterosaur with a pterodactyloid skull  

UK PubMed Central (United Kingdom)

The fossil record is a unique source of evidence for important evolutionary phenomena such as transitions between major clades. Frustratingly, relevant fossils are still comparatively rare, most transitions...Full Text Available

2010-02-07

285

Epignathus with Fetiform Features  

UK PubMed Central (United Kingdom)

Epignathus is an extremely rare oropharyngeal teratoma that commonly arises from the palate, leading to a high mortality (80–100%) due to airway obstruction in the neonatal period. We present...Full Text Available

2011-01-01

286

Endovascular covered stenting for the management of post-percutaneous nephrolithotomy renal pseudoaneurysm: a case report  

UK PubMed Central (United Kingdom)

IntroductionIntrarenal pseudoaneurysm is a rare, yet clinically significant, complication of percutaneous nephrolithotomy. A high index of clinical suspicion is necessary in order...Full Text Available

287

Endoscopic Discectomy for the Cauda Equina Syndrome During Third Trimester of Pregnancy  

UK PubMed Central (United Kingdom)

Low back pain is common during pregnancy. However, the prevalence of symtomatic lumbar disc herniation is rare, and cauda equina syndrome due to disc herniation during pregnancy is even rarer. We report...Full Text Available

2007-11-01

288

Dobutamine stress test and beta-agonist - a potential concern for nuclear cardiology testing: a case report  

UK PubMed Central (United Kingdom)

IntroductionChest pain with ST-segment elevation is a rare clinical problem during dobutamine stress testing. Although beta-agonists treatment prior to dobutamine stress testing...Full Text Available

289

Differentiation of trophoblast stem cells into giant cells is triggered by p57/Kip2 inhibition of CDK1 activity  

UK PubMed Central (United Kingdom)

Genome endoreduplication during mammalian development is a rare event for which the mechanism is unknown. It first appears when fibroblast growth factor 4 (FGF4) deprivation induces differentiation...Full Text Available

2008-11-01

290

Diagnostic Dilemma in an Unusual Case of Common Bile Duct Obstruction  

UK PubMed Central (United Kingdom)

Biliary obstructions are rarely caused by a foreign body and have received sparse attention. We present an unusual case with pruritis and abdominal pain caused by impacted full length surgical gauze...Full Text Available

2011-06-01

291

Diagnosis of Ewing's sarcoma in the thoracic spine - problems in differential diagnosis  

International Nuclear Information System (INIS)

Spinal Ewing's sarcomas are rare and cause problems in differential diagnosis. The radiologic, nuclear medicine and CT findings in two children with histologically proven Ewing's sarcoma are presented and problems in differential diagnosis discussed. Biopsy should be done early. (orig.).

292

Dedifferentiated liposarcoma of the small bowel mesentery presenting as a submucosal mass  

UK PubMed Central (United Kingdom)

Dedifferentiated liposarcoma (DDLPS) is a variant of liposarcoma but with a more aggressive course. It occurs most commonly in the retroperitoneum and rarely in any other anatomical location. We describe...Full Text Available

2011-07-15

293

DNA methylation and gene expression differences in children conceived in vitro or in vivo  

UK PubMed Central (United Kingdom)

Epidemiological data indicate that children conceived in vitro have a greater relative risk of low birth-weight, major and minor birth defects, and rare disorders involving imprinted...Full Text Available

2009-10-15

294

Cytological diagnosis of a rare case of solid pseudopapillary neoplasm of the pancreas  

UK PubMed Central (United Kingdom)

A 23-year-old woman presented to our hospital with nonspecific pain in the abdomen. She underwent radiological investigations, which revealed a solid and cystic mass in the tail end of the pancreas....Full Text Available

2010-01-01

295

Cystic Dysplasia of the Rete Testis Accompanying an Inguinal Hernia: A 63-Year-Old Man  

UK PubMed Central (United Kingdom)

Cystic dysplasia of the rete testis (CDT) is a very rare congenital benign testicular tumor that is often associated with ipsilateral genitourinary anomalies. It is usually found in the pediatric population...Full Text Available

2011-07-01

296

Contrasting Population Structures of the Genes Encoding Ten Leading Vaccine-Candidate Antigens of the Human Malaria Parasite, Plasmodium falciparum  

UK PubMed Central (United Kingdom)

The extensive diversity of Plasmodium falciparum antigens is a major obstacle to a broadly effective malaria vaccine but population genetics has rarely been used to guide vaccine design....Full Text Available

297

Confusion after spine injury: cerebral fat embolism after traumatic rupture of a Tarlov cyst: Case report  

UK PubMed Central (United Kingdom)

BackgroundAcute low back pain is a very common symptom and reason for many medical consultations. In some unusual circumstances it could be linked to a rare aetiology.Case...Full Text Available

298

Colonoscopic perforation leading to a diagnosis of Ehlers Danlos syndrome type IV: a case report and review of the literature  

UK PubMed Central (United Kingdom)

IntroductionColonoscopic perforation is a rare but serious complication of colonoscopy. Factors known to increase the risk of perforation include colonic strictures, extensive diverticulosis,...Full Text Available

299

Colon Mucinous Adenocarcinoma in Childhood: A Case Report with Emphasis on Image Findings  

UK PubMed Central (United Kingdom)

Colorectal cancer is extremely rare in children. We report a case of a 12-year-old boy who presented with a five-month history of weight loss and anorexia, associated with vomiting episodes, dizziness,...Full Text Available

2010-01-01

300

Chylopericardium after cardiac surgery can be treated successfully by oral dietary manipulation: a case report  

UK PubMed Central (United Kingdom)

We report a case of chylopericardium after ascending aorta and aortic valve replacement, which presented as late tamponade. We discuss the various treatment options in this rare condition which can...Full Text Available

301

Charge transfer transitions and location of the rare earth ion energy levels in Ca-#alpha#-SiAlON  

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.

2009-06-01

302

Carcinoma Metastatic to Both Cerebellopontine Angles Masquerading as Acoustic Neuromas  

UK PubMed Central (United Kingdom)

Metastases to the cerebellopontine angles (CPAs) are rare. Typically, the clinical course is one of rapid onset and progression of crarial nerve deficits. The clinical presentation and course of carcinoma...Full Text Available

1995-01-01

303

Blarina toxin, a mammalian lethal venom from the short-tailed shrew Blarina brevicauda: Isolation and characterization  

UK PubMed Central (United Kingdom)

Venomous mammals are rare, and their venoms have not been characterized. We have purified and characterized the blarina toxin (BLTX), a lethal mammalian venom with a tissue kallikrein-like activity...Full Text Available

2004-05-18

304

Bilateral Pneumothorax and Subcutaneous Emphysema following Endoscopic Retrograde Cholangiopancreatography: A Rare Complication  

UK PubMed Central (United Kingdom)

Endoscopic Retrograde Cholangiopancreatography (ERCP) is a widely used diagnostic and therapeutic modality in the management of biliary and pancreatic disease. Some of the complications of the procedure,...Full Text Available

2010-01-01

305

Autoimmune pancreatitis with atypical imaging findings that mimicked an endocrine tumor  

UK PubMed Central (United Kingdom)

Autoimmune pancreatitis (AIP) is a rare cause of recurrent acute pancreatitis or chronic pancreatitis in middle-aged patients, and is characterised by a marked infiltration of lymphocytes and plasma...Full Text Available

2010-06-21

306

Association between skin diseases and severe bacterial infections in children: case-control study  

UK PubMed Central (United Kingdom)

BackgroundSepsis or bacteraemia, however rare, is a significant cause of high mortality and serious complications in children. In previous studies skin disease or skin infections...Full Text Available

307

Angiosarcoma of the of scalp with calvarium involvement in a 50-year-old African-American man.  

UK PubMed Central (United Kingdom)

BACKGROUND: Angiosarcoma of the scalp is a rare, aggressive, and deadly cancer that affects mainly elderly Caucasian men. OBJECTIVES: The insidious and masquerading presentation of angiosarcoma poses...Full Text Available

2004-11-01

308

Angiomatoid giant cellular blue nevus of vaginal wall associated with pregnancy  

UK PubMed Central (United Kingdom)

BackgroundBlue nevi that arise from the Müllerian tract are rare melanocytic lesions. Several histopathologic variants of cellular blue nevi have been described. The angiomatoid...Full Text Available

309

An unusual presentation of adenoid cystic carcinoma of the minor salivary glands with cranial nerve palsy: a case study  

UK PubMed Central (United Kingdom)

BackgroundAdenoid Cystic Carcinoma (ACC) is a rare tumor entity and comprises about 1% of all malignant tumor of the oral and maxillofacial region. It is slow growing but a highly...Full Text Available

310

An excess of rare genetic variation in ABCE1 among Yorubans and African-American individuals with HIV-1  

UK PubMed Central (United Kingdom)

Signatures of natural selection occur throughout the human genome and can be detected at the sequence level. We have re-sequenced ABCE1, a host candidate gene essential for...Full Text Available

2009-12-01

311

Aggressive behaviour of solid-pseudopapillary tumor of the pancreas in adults: A case report and review of the literature  

UK PubMed Central (United Kingdom)

Solid-pseudopapillary tumor (SPT) is a rare neoplasm of the pancreas that usually occurs in young females. It is generally considered a low-grade malignant tumor that can remain asymptomatic for several...Full Text Available

2008-02-14

312

Acute aortic thrombosis in patients receiving cisplatin-based chemotherapy  

UK PubMed Central (United Kingdom)

The increased risk of thrombosis in patients with active cancer has multiple causes. Acute thrombosis of the aorta is an exceedingly rare but potentially devastating complication in patients with cancer...Full Text Available

2011-04-01

313

A survey of community members' perceptions of medical errors in Oman  

UK PubMed Central (United Kingdom)

BackgroundErrors have been the concern of providers and consumers of health care services. However, consumers' perception of medical errors in developing countries is rarely explored....Full Text Available

314

A Wireless Health Outcomes Monitoring System (WHOMS): development and field testing with cancer patients using mobile phones  

UK PubMed Central (United Kingdom)

BackgroundHealth-Related Quality of Life assessment is widely used in clinical research, but rarely in clinical practice. Barriers including practical difficulties administering...Full Text Available

315

A Rare Null Allele Potentially Encoding a Dominant-Negative TRIM5? Protein in Baka Pygmies  

UK PubMed Central (United Kingdom)

The global acquired immunodeficiency syndrome (AIDS) pandemic is thought to have arisen by the transmission of human immunodeficiency virus (HIV-1)-like viruses from chimpanzees in southeastern...Full Text Available

2009-08-15

316

A Cytogenetic Abnormality and Rare Coding Variants Identify ABCA13 as a Candidate Gene in Schizophrenia, Bipolar Disorder, and Depression  

UK PubMed Central (United Kingdom)

Schizophrenia and bipolar disorder are leading causes of morbidity across all populations, with heritability estimates of ∼80% indicating a substantial genetic component. Population genetics...Full Text Available

2009-12-11

317

A Case of Neurocysticercosis in Entire Spinal Level  

UK PubMed Central (United Kingdom)

Cysticercosis is the most common parasitic infection affecting the central nervous system. Spinal neurocysticercosis (NCC) is very rare compared with intracranial NCC and requires more aggressive management...Full Text Available

2010-10-01

318

ZrO_2/O' sialon composites containing mixed additives  

International Nuclear Information System (INIS)

Mixed additions of Sm_2O_3 and Y_2O_3 were used in the formation of zirconia-containing O'-sialon composites, where Sm_2O_3 was used for the purpose of densification and Y_2O_3 for zirconia stabilization. Dense ZrO_2/O' -sialon composites were produced at 1500 deg C. by sintering in nitrogen for 4 hours. Tetragonal zirconia remained in the product and t#->#m transformation was observed when the sample was ground into powder. However, the improvement in fracture toughness was not significant and this was attributed to the weakened transformability of the tetragonal zirconia phase in the nitrogen-based materials. 18 refs., 4 tabs., 2 figs.

319

The activity profile and cross section of isotopes from #alpha#-induced nuclear reaction on Zr for radioanalytical applications  

International Nuclear Information System (INIS)

The cross section and activity profile of different radioisotopes produced by #alpha#-induced nuclear reaction on natural zirconium, have been obtained by stacked foil activation using 40 MeV #alpha#-particles from Variable Energy Cyclotron (VEC) machine at Calcutta. The activity profile would be used to study the surface loss of zircaloy materials of engineering components by thin layer activation (TLA) technique. Generally, isotopes with suitable #gamma#-rays and long half-lives are the most useful in TLA technique, e.g., "9"2Nb, "9"5"gNb and "9"5Zr. (author). 2 refs., 1 tab.

1995-02-01

320

Structure, morphology and hydrogen storage properties of composites prepared by ball milling Ti{sub 0.9}Zr{sub 0.2}Mn{sub 1.5}Cr{sub 0.3}V{sub 0.3} with La-Mg-based alloy  

Energy Technology Data Exchange (ETDEWEB)

Hydrogen storage alloy composites La{sub 0.7}Mg{sub 0.25}Zr{sub 0.05}(Ni{sub 0.85}Co{sub 0.15}){sub 3.5}(x=0,5,10) were prepared by ball milling method. Their structures, morphologies and the hydrogen storage characteristics were intensively studied in the present work. It was found that the bulk of composites maintained the hexagonal C14 Laves phase structure after ball milling with additional La-Mg-based alloy for two hours. Scanning electron microscopy (SEM) observations revealed that the average size of Ti{sub 0.9}Zr{sub 0.2}Mn{sub 1.5}Cr{sub 0.3}V{sub 0.3} and La{sub 0.7}Mg{sub 0.25}Zr{sub 0.05}(Ni{sub 0.85}Co{sub 0.15}){sub 3.5} particles were reduced to several hundred nanometers after ball milling process. Energy dispersive X-ray spectrometer (EDS) patterns of the composites showed that the La{sub 0.7}Mg{sub 0.25}Zr{sub 0.05}(Ni{sub 0.85}Co{sub 0.15}){sub 3.5} phase was uniformly distributed on ...

2007-10-15

321

Recovery of transplutonium elements from aqueous and water-ethanol solutions of sulfuric acid and their separation from other actinides  

Energy Technology Data Exchange (ETDEWEB)

The behavior of Am, Cm, Bk, Cf, Es, and other actinides, as well as Zr, on anion and cation exchangers in aqueous and water-ethanol solutions of sulfuric acid as a function of the various components of the solution has been investigated. It has been discovered that the presence of ethanol in sulfuric acid solutions causes an increase in the distribution coefficients both on cation exchangers and on anion exchangers. The possibility of the use of ion exchangers for the preconcentration and separation of transplutonium elements from U, Np, Pu, Zr, and other elements which form strong complexes with sulfate ions over a broad range of concentrations of sulfuric acid has been demonstrated.

1988-05-01

322

Particulate composites in the TiC-TiYTZP system  

International Nuclear Information System (INIS)

Twelve powders of TiO_2-Y_2O_3-ZrO_2 solid solution of the methodically changed composition were prepared by a coprecipitation-calcination technique. After mixing with phenol-formaldehyde resin, the powders were calcinated for 2 hours at 1200"oC in vacuum. The resultant composite powders contained TiC and non-reacted carbon. Green compacts were sintered in vacuum at 1500"oC for 2 hours. A temperature increase was stopped at 1200"oC to react remains of carbon. There were two carbides in the composites TiC and ZrC. TiC non-stoichiometry depended on carbon content in the system. Phase composition of the depended on of titania and yttria in zirconia solid solution. The majority of the samples showed two tetragonal zirconia phases differing in lattice parameter and tetragonality. (author)

2004-09-12

323

Partial width fluctuation method of determining nuclear level density  

Energy Technology Data Exchange (ETDEWEB)

A new method of determining the nuclear level density is presented. This method is based on the statistical analysis of the partial width fluctuations appearing in an excitation function of the radiative proton capture. The method was applied in the case of the /sup 88/Sr(p,..gamma..sub(..omega..))/sup 89/Y and /sup 89/Y(p,..gamma..sub(..omega..))/sup 90/Zr reactions. The density of levels with spin I/sup -/ in /sup 90/Zr and the densities of levels with spins 1/2/sup +/ and 3/2/sup +/ in /sup 89/Y at excitation energies from 10.9 to 11.6 MeV and from 9.3 to 10.8 MeV respectively, were determined with an uncertainty of about 35%.

1982-04-12

324

Lowering the activation temperature of TiZrV non-evaporable getter films [for LHC  

CERN Document Server

In order to reduce the activation temperature of the TiZrV alloy, thin films of various compositions were produced by three-cathode magnetron sputtering on stainless-steel substrates. For the characterisation of the activation behaviour the surface chemical composition has been monitored by Auger electron spectroscopy during specific in situ thermal cycles. The volume elemental composition of the film has been measured by energy dispersive X-ray spectroscopy and the morphology (crystal structure and size of the crystallites) has been investigated by X-ray diffraction. The criteria indicating the sample quality and its dependence on film structure and chemical composition are presented and discussed. (13 refs).

2001-01-01

325

High-spin-state spectroscopy with the reaction /sup 88/Sr(p/sub pol/,. pi. /sup -/)/sup 89/Zr  

Energy Technology Data Exchange (ETDEWEB)

The pronounced selectivity of near-threshold (p,..pi../sup -/) reactions for high-spin two-particle, one-hole states is exploited, in the first spectroscopic application of a (p,..pi..) reaction, to identify previously unknown 25/2/sup +/ and 21/2/sup +/ (g/sub 9/2/)/sup 3/ states in /sup 89/Zr. Relative cross sections for the two transitions are well reproduced by simple model calculations. The analyzing power for the 25/2/sup +/ state is markedly similar to previous (p/sub pol/,..pi../sup -/) results for two-particle one-hole stretched states in lighter nuclei.

1984-11-12

326

First principles investigations of formation of ordered omega phases in Zr-Al alloys  

International Nuclear Information System (INIS)

First-principles density functional theory (DFT) based calculations were performed to study the electronic and cohesive properties of all the intermediate ordered phases appearing in the transformation from bcc-based #beta# to hexagonal ordered #omega# phase in Zr_3Al alloy. Full-potential linear augmented plane wave (FPLAPW) method under the GGA was employed to establish the stability hierarchy and structure-property correlations. Further, effective pair potentials upto the fourth nearest neighbours were extracted, which, subsequently, were used for the thermodynamics analysis of the thermally-induced #beta##->##omega# transformation. The lattice collapse mechanism involving the concept of the onset of a displacement wave where the extent of collapse is viewed as an amplification of the displacement wave was employed for further analysis. (author)

2005-12-05

327

Electrochemical behaviour of multicomponent Zr-Ti-V-Mn-Cr-Ni alloys in alkaline solution  

Energy Technology Data Exchange (ETDEWEB)

The effect of the composition of multicomponent Zr-Ti-V-Mn-Cr-Ni alloys on their hydrogen-storage capacity and on the rate of electrosorption/desorption hydrogen was investigated under potentiodynamics as well as single-pulse and long-term galvanostatic conditions. The main characteristics of alloys and alloy electrodes were determined by their structural analysis by means of X-ray diffraction and scanning electron microscope, by specific surface area test and by determination of the hydrogen absorption/desorption isotherms in the gas/solid phase system. It was found that only the alloys with a manganese content below a threshold could be used as electrode materials for Ni-MH batteries, whereas the modification of the electrode material by micro-encapsulation of alloy particles should limit the dissolution of manganese from the electrode material in a strong alkaline solution. (orig.)

1996-01-01

328

Determination of the. pi. 1g/sub 9/2/ orbit size in /sup 88/Sr, /sup 90/Zr, and /sup 92/Mo from inelastic electron scattering  

Energy Technology Data Exchange (ETDEWEB)

A study of the ..pi..1g/sub 9/2/ orbit size in /sup 88/Sr, /sup 90/Zr, and /sup 92/Mo is presented. The rms radius for the point-proton density is extracted by studying transitions to 8/sup +/ states in these nuclei. The radii are consistently larger than a value determined in a magnetic electron scattering experiment on /sup 93/Nb. A qualitative discussion of the ground state occupation of the ..pi..1g/sub 9/2/ orbit based on the transition amplitudes to the 8/sup +/ states is given.

1985-09-01

329

Cavitation erosion of advanced ceramics in water  

Energy Technology Data Exchange (ETDEWEB)

The performance of advanced ceramics under cavitation loading in distilled water was studied by using a laboratory test with vibration-induced cavitation following the pattern of the ASTM standard G32-92. The hardened and tempered martensitic steel 100Cr6 was used as a reference. The aim was to identify mechanisms and the effects of important microstructural parameters on damage of polished Al{sub 2}O{sub 3}, Al{sub 2}O{sub 3}-ZrO{sub 2}, ZrO{sub 2} and SiC ceramics. Results showed that surface damage of brittle ceramics was mainly dominated by intergranular fracture, followed by detachment of single grains or fragments of them. Both incubation time and erosion rate were affected by the amount of initial surface cavities, grain sizes and secondary phases at grain boundaries. (orig.)

2006-10-15

330

Behavior of Stress-Relaxation phenomena in Zr-1.1Nb-0.05Cu  

International Nuclear Information System (INIS)

Zirconium alloys have anisotropic mechanical properties depending on their physical orientations and are widely used as nuclear materials such as cladding tube material. An operation condition of the nuclear reactor requires a high creep resistance, because it is subjected to long period operations, high temperature and high pressure. Generally, it takes a few days or months to do the creep experiment, so it is difficult to get a data in short period. However, there is a way to predict a creep property by using the stress-relaxation in the short term. These studies realized the stress-relaxation through a compressive test of HANA-6 (Zr-1.1Nb-0.05Cu) alloy that was developed by KAERI (Korea Atomic Energy Research Institute), and then predicted the creep property

2010-10-01

331

Amorphization of Zr_6_0Al_1_5Ni_2_5 surface layers by laser processing for corrosion resistance  

International Nuclear Information System (INIS)

It is generally known that a number of metallic glasses have excellent corrosion resistance in a variety of chemically hostile environments. Consequently, the use of laser cladding to coat a massive crystalline material such as aluminium with a layer of a metallic glass has obvious advantages. In this paper, the authors will show that the formation of a predominantly amorphous layer of Zr_6_0Al_1_5NI_2_5 alloy by laser processing is possible, if the obstacles to amorphization are overcome. In addition, evidence of the excellent corrosion resistance of this alloy in a NaCl solution will be given. A comparative study of the corrosion behavior of this amorphous alloy with pure aluminium and Al-Cr alloy will be done, in order to complete previous studies of laser processed coatings of aluminum substrates.

332

A study of the isomeric ratio for the (n,2n) and (#betta#,n) reactions in Mo92, Zr90, Sr86 and Se74  

International Nuclear Information System (INIS)

Measurements are made of the isomeric ratio for the (n,2n) and (#betta#,n) reactions on the neutron-deficient nuclei _9_2Mo, _9_0Zr, _8_6Sr and _7_4Se. A method is developed for calculating the isomeric ratio for a low excitation energy of the residual nucleus. The good agreement found between experimental results and calculations for the (#betta#,n) reaction confirms the choices of residual nucleus characteristics, transmission coefficients of neutrons emitted etc. used in the calculations. The results of a study of the (n,2n) reaction were used to find the spin dependences of nuclear level density in the excitation energy region approx. 14 MeV. (author).

1998-10-01

333

/sup 90,91/Zr (n,#alpha#) /sup 87,88/Sr reactions at 14.3 and 18.15 MeV incident neutron energy  

International Nuclear Information System (INIS)

Measurements of alpha spectra in the (n, #alpha#) reactions induced on /sup 90,91/Zr at 14.3 and 18.15 MeV incident neutron energy are presented. A microscopic calculation of these spectra has been made using both pick-up and knock-on theories, and in both cases only one overall normalizing factor, which is the same for the two target nuclei and incident energies and all the considered transitions, appears as a free parameter in the calculation. Pick-up calculations provide a very satisfactory reproduction of the data. Knock-on calculations reproduce many qualitative features of the measured spectra, but do not allow a fully satisfactory reproduction of them. While the results obtained do not exclude knock-on contributions to these reactions, their presence is not established.

334

Temperature Dependences of Leakage Currents of ZnO Varistors Doped with Rare-Earth Oxides  

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.

2010-01-01

335

Spectroscopic study of rare earth chromates: relation to the structure  

International Nuclear Information System (INIS)

The luminescence spectra of trivalent europium ion embedded in various rare earth chromates were analysed. The spectroscopic data in most of chromates are in agreement with the structural determination but for some others the discrepancy between two methods is underlined. Energy level schemes were deducted from the experimental emission spectra and the crystal field simulation has been performed. The maximum splitting of the "7F_1 manifold of the Eu"3"+ ion as a function of N_v, the so-called crystal field strength parameter, is given. This allows us to classify the compounds according to their crystal field extent. (author)

1996-03-24

336

Simulation of statistical {gamma}-spectra of highly excited rare earth nuclei  

Energy Technology Data Exchange (ETDEWEB)

The statistical {gamma}-spectra of highly excited even-even rare earth nuclei are simulated applying appropriate level density and strength function to a given nucleus. Hindrance effects due to K-conservation are taken into account. Simulations are compared to experimental data from the {sup 163}Dy({sup 3}He,{alpha}){sup 162}Dy and {sup 173}Yb({sup 3}He,{alpha}){sup 172}Yb reactions. The influence of the K quantum number at higher energies is discussed. 21 refs., 7 figs., 2 tabs.

1997-05-01

337

Occurrence of magnetism in superconductors  

Science.gov (United States)

We discuss how magnetic phenomena affect superconductivity in simple metals, transition metals and alloys thereof, and dilute Rare-Earth alloys. It is shown both qualitatively and quantitatively that superconductors are sensitive probes for studying itinerant spin excitations, local spin excitations associated with nearly magnetic impurities, the effect of the atomic environment on the stability of local magnetic moments, and the nature of the spin order in Rare-Earth alloys. Also, we discuss how magnetic impurities can be used to study the electronic configuration which is responsible for superconductivity in Laves-phase crystals like A-15 compounds and ..beta..-W crystals, for example.

1970-12-14

338

$B \\to X_{s} \\gamma$ and $B \\to X_{s} l^{+} l^{-}$ decays at LHCb  

CERN Document Server

\\lhcb is one of the four major experiments at the Large Hadron Collider (\\lhc) at CERN. It is custom built to look for CP violation and New Physics in rare decays of heavy flavour hadrons, like the B and D systems. Rare decays that occur via loop diagrams provide a way to probe New Physics at energy scales much higher than can be probed by direct production in experiments. In this article, the \\lhcb prospects for such measurements with exclusive decays of the type $B \\to \\Xs \\gamma$ and $B \\to X_{s} l^{+} l^{-}$ are presented.

2011-01-01

339

$B \\to X_s\\gamma$ and $B\\to X_sl^+l^-$ decays at LHCb  

CERN Document Server

LHC$b$ is one the four major experiments at the Large Hadron Collider (LHC) at CERN. It is custom built to look for CP violation and New Physics in rare decays of heavy flavor hadrons, like the B and D systems. Rare decays that occur via loop diagrams provide a way to probe New Physics at energy scales much higher than can be probed by direct production in experiment. In this article, the LHC$b$ prospects for such measurement with exclusive decays of the type $B \\to X_s\\gamma$ and $B\\to X_sl^+l^-$ are presented.

2011-01-01

340

DECAY OF Ta$sup 177$ AND Lu$sup 177$ TO LEVELS IN Hf$sup 17$$sup 7$  

Science.gov (United States)

The decays of Ta/sup 177/ and Lu/sup 177/ to levels in vestigated with beta spectrometers, NaI(Tl) gamma spectrometers, and fast coincidence and angular correlation techniques. Energy levels in Hf/sup 177/ were characterized according to their energy (kev), the Nilsson asymptotic quantum numbers (Nn/sub 2/ LAMBDA ), the total angular momentum and its component along the symmetry axis (I,K), and the parity ( pi ) as follows: 0STA5I4 7/2, 7/2-!; 112.97STA514 9/2, 7/ 2-!; 249.7STA5I4 11/2, 7/1-!; 32l.34STA624 9/2, 9/2+1; 447.9STA624 11/2, 585.8STA642 7/2, 3/2+1; 509.0STA5I2 5/2, 5/1-1; 605.5STA512 7/2, 5/2-!; 746.04STA633 7/2, 7/2+1; 848.2STA 633 9/2, 7/2+1; and 1058.38STA503 7/2, 7/2-!. The levels at 447.9, 488.8, and 585.8 kev are tentative. The spins and parities were uniquely determined by angular correlation and internal conversion data for the levels at 746.0 and 848.2 kev, asof the levels at 0, 113.0 249.7, and 321.3 kev are correct ...

1961-10-15

341

The impact of solar flares and magnetic storms on humans  

International Nuclear Information System (INIS)

Three classes of solar emanations, namely, photon radiation from solar flares, solar energetic particles, and inhomogeneities in the solar wind that drive magnetic storms, are examined, and their effects on humans and technological systems are discussed. Solar flares may disrupt radio communications in the HF and VLF ranges. Energetic particles pose a special hazard at low-earth orbit and above, where they can penetrate barriers such as spacesuits and aluminum and destroy cells and solid state electronics. Energetic solar particles also influence terrestrial radio waves propagating through polar regions. Magnetic storms may disturb the operation of navigation instruments, power lines and pipelines, and satellites; they give rise to ionospheric storms which affect radio communication at all latitudes. There is also a growing body of evidence that changes in the geomagnetic field affect biological systems. 3 refs.

342

Supercritical Fluid Immersion Deposition: A New Process for Selective Deposition of Metal Films on Silicon Substrates  

Energy Technology Data Exchange (ETDEWEB)

Supercritical CO2 is used as a new solvent for immersion deposition, a galvanic displacement process traditionally carried out in aqueous HF solutions containing metal ions, to selectively develop metal films on featured or non-featured silicon substrates. Components of supercritical fluid immersion deposition (SFID) solutions for fabricating Cu and Pd films on silicon substrates are described along with the corresponding experimental setup and procedure. Only silicon substrates exposed and reactive to SFID solutions can be coated. The highly pressurized and gas-like supercritical CO2, combined with the galvanic displacement property of immersion deposition, enables the SFID technique to selectively deposit metal films in small features. SFID may also provide a new method to fabricate palladium silicide in small features or to metallize porous silicon.

2005-01-01

343

Site occupancies in ternary C15 ordered Laves phases  

Energy Technology Data Exchange (ETDEWEB)

Site occupancies in three C15-structured AB{sub 2}(X) Laves phases have been determined by Atom Location by CHanneling Enhanced MIcroanalysis (ALCHEMI). In NbCr{sub 2}(V), the results were consistent with exclusive site occupancies of Nb for the A sublattice and Cr and V for the B sublattice. The B-site occupancy of V is not expected from atom size effects alone. In NbCr{sub 2}(Ti), the results were consistent with Ti partitioning mostly to the A sites with some anti-site defects likely. In HfV{sub 2}(Nb), the results were consistent with Nb partitioning between the A and B sites. The results of the ALCHEMI analyses of these ternary C15 Laves phase materials will be discussed with respect to previously determined phase diagrams and first-principles total energy and electronic structure calculations.

1996-12-31

344

Shifts in soil organic matter composition following treatment with sodium hypochlorite and hydrofluoric acid  

British Library Electronic Table of Contents (United Kingdom)

A renewed interest in chemical fractionation of soil organic matter (SOM) originates from the premise that it enables to isolate labile SOM from SOM protected through mineral binding and recalcitrant SOM. Both selective removal of labile non-bound SOM through oxidation or hydrolysis as well as selective removal of minerals and attached SOM are often applied. Molecular-level SOM characterization by means of temperature resolved Pyrolysis-Field Ionization Mass Spectroscopy analysis (Py-FIMS) was used here as an approach to obtain insight into the fate of SOM upon wet chemical treatment with regard to composition and thermal stability. The applied sequential chemical treatment with 6% NaOCl and 10% HF yielded similar sizes in stable SOM fractions between sandy semi-native heathland and cultiv...

2009-01-01

345

Safety testing of 18650-style Li-Ion cells  

Energy Technology Data Exchange (ETDEWEB)

To address lithium-ion cell safety issues in demanding power applications, electrical and thermal abuse tests were performed on 18650 sized cells. Video and electrically monitored abuse tests in air included short circuit, forced overcharge, forced reversal, and controlled overheating (thermal) modes. Controlled overheating tests to 200 C were performed in a sealed chamber under a helium atmosphere and the gases released from the cell during thermal runaway were analyzed at regular intervals using gas chromatography and mass spectrometry. In addition to alkane and alkene solvent breakdown fragments, significant H{sub 2} was detected and evidence that HF was evolved was also found.

2000-06-08

346

Plutonium metal dissolution in HNO_3-HCOOH solution  

International Nuclear Information System (INIS)

A great deal of studies of the Pu metal dissolution by mineral acids have been made /1-3/. Hydrochloric acid was shown to provide the most complete and fastest dissolution /1-2/. The majority of studies describes the use of HNO_3-HF or HNO_3 with reducing or oxidizing agents present for this purpose /4/. But these methods are not quite adequate because of an extreme corrosiveness of the acids and a high cost of structural materials. That is why a search for more reliable and safer process is still in progress. The HNO_3-HCOOH method of dissolving has been investigated. Some physical-chemical properties of formic acid as well as regulations on its use are presented in /5-8/. (author).

347

Plasma nitrided titanium as a bipolar plate for proton exchange membrane fuel cell  

Energy Technology Data Exchange (ETDEWEB)

Plasma nitriding was applied to improve the surface performance of titanium bipolar plate. XRD and SEM results showed a titanium nitride layer was formed after nitridation. In comparison with pure titanium, the interfacial contact resistance of plasma nitrided titanium was reduced to some extent by the nitridation treatment. However, high corrosion current was observed under electrochemical tests in 0.5 M H{sub 2}SO{sub 4} + 5 ppm HF. Both the electrical conductivity and corrosion resistance of the surface of plasma nitriding titanium did not reach the level of graphite. Some more improvements are expected in the plasma nitriding process or another surface modification on pure titanium. (author)

2009-02-15

348

Nuclear magnetic resonance on oriented "1"7"5Ta and "1"7"7Ta  

International Nuclear Information System (INIS)

"1"7"5Ta and "1"7"7Ta nuclei were oriented at low temperature as dilute impurities in Fe. The magnetic hyperfine splitting frequencies #nu#="+#mu#B sub(HF)/Ih"+ of the "1"7"5Ta and "1"7"7Ta ground states have been measured to be 320.45(11) and 317.552(55) MHz by using the technique of NMR-ON. Taking the known hyperfine field of "1"8"1Ta in Fe, the magneticmoments have been deduced: "+#mu#("1"7"5Ta, 7/2"+)"+=2.270(45) and "+#mu#("1"7"7Ta, 7/2"+)"+=2.250(45)#mu# sub(N). These values of the magnetic moments are discussed in the framework of the rotational model. (author).

349

Ionizing radiation is a potent inducer of mitotic recombination in mouse embryonic stem cells  

British Library Electronic Table of Contents (United Kingdom)

Maintenance of genomic integrity in embryonic cells is pivotal to proper embryogenesis, organogenesis and to the continuity of species. Cultured mouse embryonic stem cells (mESCs), a model for early embryonic cells, differ from cultured somatic cells in their capacity to remodel chromatin, in their repertoire of DNA repair enzymes, and in the regulation of cell cycle checkpoints. Using 129XC3HF1 mESCs heterozygous for Aprt, we characterized loss of Aprt heterozygosity after exposure to ionizing radiation. We report here that the frequency of loss of heterozygosity mutants in mESCs can be induced several hundred-fold by exposure to 5-10Gy of X-rays. This induction is 50-100-fold higher than the induction reported for mouse adult or embryonic fibroblasts. The primary mechanism underlying the...

2011-01-01

350

Extraction of hafnium by 1-phenyl-3-methyl-4-benzoyl-5-pyralozone from aqueous-alcoholic solutions  

International Nuclear Information System (INIS)

Extraction of hafnium by 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (HL) in benzene, toluene, chloroform and tetrachloromethane from aqueous-alcoholic solutions of the formal acidity of 2M-HClO_4 was studied. Methyl, ethyl, n- and isopropyl, tert-butyl and allyl alcohol as well as ethylene glycol monomethyl ether and propylene glycol were used as organic components of the mixed aqueous-organic phase. Their presence in some cases resulted in a synergic increase in the distribution ratio of hafnium. The increase is interpreted using the results of a slope analysis and measurements of the alcohol distribution and the relative permittivity of the organic phase. It is suggested that HfL_4 molecules were solvated by alcohol molecules in the organic phase. At high alcohol concentration synergism changed into antagonism. This was caused by changes in the distribution of HL and its interaction with the alcohol in the organic phase. (author).

351

Experimental study on display-control stereotype and development of human factors guidelines  

Energy Technology Data Exchange (ETDEWEB)

It is very important to develop the design guidelines which can be applicable for Korean operators for the purpose of designing the KSNP more safely. The objective of this project is to provide the standards, guidelines and bases applicable for HF-010 through the within-subject experiment for obtaining Korean operators' population stereotype for direction-of-movement of controls associated with displays on the control panels. Through the survey of researches on display compatibility and the classification of types of displays and controls in the main control room of Uljin units 3 and 4, methods for an experiment on the stereotype were established. Experimental interface prototypes for a total of 108 combinations of display and control types were implemented. Experimental data collection and analysis system was built in association with the interface prototypes. The experiment was performed with participation of 250 students as subjects. About 20 guideline ...

2003-01-01

352

Dimensioning of the cooling system of the capacitors operating in a high frequency antenna, through a finite element method; Dimensionnement du systeme de refroidissement des condensateurs d'une antenne a haute frequence, par la methode des elements finis  

Energy Technology Data Exchange (ETDEWEB)

The aim of this work is the study of the heat transfer and of thermal behaviour of the HF (high frequency) components (in fact capacitors) of the ITER-proto-2005-FCI antenna. Preliminary results carried out with the Castem software show that it is possible to cool the hottest part of the antenna efficiently. A water flow (1 bar, 25 Celsius degrees) or an helium flow (10 bars, 50 Celsius degrees) permit to limit the maximal value of the temperature to 270 Celsius degrees. A second software Ansys has allowed the author to simulate capacitors with more complicated shapes. (A.C.)

2003-07-01

353

Development of Plasma Technologies at IPP NSC KIPT  

International Nuclear Information System (INIS)

Plasma Technologies in Institute of Plasma Physics of the NSC KIPT are recently developed in the following directions. Material surfaces modification under their irradiation with pulsed plasma streams of different working gases. Besides traditional analysis of improvements of tribological characteristics and structural-phase changes of the modified layers recently we started investigations of material corrosions characteristic improvement under influence of pulsed plasma on the material surfaces. As to the surface coatings in arc discharges of Bulat type devices, new trends are related with multi-layers coatings, using Ti-AI-N coatings in cutting tools, using high frequency discharges or combined HF- and arc discharges for increasing the nomenclature of goods to be coated. Development of ozonators is respectively new area for IPP NSC KIPT. On the base of barrier high-frequency discharge there were developed a number of high efficiency ozonators with ozone ...

2001-09-19

354

A comparison of thermal maturity parameters between freely extracted hydrocarbons (Bitumen I) and a second extract (Bitumen II) from within the kerogen matrix of Permian and Triassic sedimentary rocks  

British Library Electronic Table of Contents (United Kingdom)

In this study we compared various maturity dependent aromatic, steroid and triterpenoid hydrocarbon ratios in bitumens that are freely extractable from sedimentary rocks (Bitumen I) with those in second extracts that comprised hydrocarbons closely associated with the kerogen/mineral matrix (Bitumen II). Bitumen II was released through kerogen isolation and demineralisation using HCl and HF/H3BO3. The samples studied, although of similar age, come from different localities. They represent a range of facies and two kerogen types (II and III), and all were deposited under marine conditions. The results show that the more stable b isomers of methylnaphthalene (MN) and methylphenanthrene (MP) are relatively more abundant in Bitumen II. The difference between the methylnaphthalene ratio (MNR) of...

2010-01-01

355

lue0725b.020  

Science.gov (United States)

uJ Ccna =+!F Vl,) (On# P*9p .FGww z,r` dcb= >uD/ rN3W $ gp0w# rW8- A$c= b8aU Pkfs pmRh }>Tua }zz~ EwHc D;t' =kF9 hk6d /_sU }+>IK j'$ 0=:b "OR? ,2pz{V# U}}6 ...

356

Thermodynamics of reactions of chemically stable ceramics formation  

Energy Technology Data Exchange (ETDEWEB)

Theoretical thermodynamical calculations for the ZrO/sub 2/- Al/sub 2/O/sub 3/-SiO/sub 2/ system are given to expose the regions of the most chemically stable products of crystallization. It is established that ceramics on the base of mullite with zircon addition and containing the minimum quantity of glass phase should be preferably used in chemical media containing HCl.

1981-06-01

357

Stress Corrosion Cracking Susceptibility of Beta Titanium Alloy 38-6-44: Candidate Alloy for Scout Torsion Bar.  

Science.gov (United States)

The threshold stress itensities for stress corrosion crack propagation in beta titanium alloy 38-6-44, Ti-3Al-8V-6Cr-4Mo-4Zr, has been determined in salt water and methanolic solutions. The alloy was immune to stress corrosion cracking in aqueous sodium c...

1974-01-01

358

State-of-the-art technology for production of seamless tubes in zirconium and titanium alloys  

International Nuclear Information System (INIS)

Zircaloy fabrication plant manufactures all the necessary Zr-2 components like fuel canning tubes, calandria tubes and other rod and sheet products. This plant is having a capacity of producing about 4 lakh nos. of PHWR fuel tubes per annum. These tubes are seamless, thin walled with close dimensional tolerances and stringent mechanical properties. The plant has established all the facilities required to produce these tubes with required quality.

359

SOME RECENT DETERMINATIONS OF ATOMIC MASSES IN THE STRONTIUM-ZIRCONIUM REGION  

Science.gov (United States)

A large double-focusing mass spectrometer was used to obtain new values for the masses of Sr/sup 86/, Sr/sup 88/, and Zr/sup 90/. Mass differences calculated from these values are found to be in better agreement with nuclear transmutation information than were previous mass spectroscopically derived values. (auth)

1960-06-01

360

Quenching of the 2psub(1/2)-2psub(3/2) proton spin-orbit splitting in the Sr-Zr region  

Energy Technology Data Exchange (ETDEWEB)

The constancy in excitation energy of the lowest 2/sup +/ state in the Sr isotopes across the N=56 subshell closure is shown to result from a reduction in the 2psub(1/2)-2psub(3/2) proton spin-orbit splitting as the 2dsub(5/2) neutron orbital is filled.

1984-06-14

361

Properties of Beta-C trademark (Ti-3Al-8V-6Cr-4Mo-4Zr)  

International Nuclear Information System (INIS)

Beta C trademark, a metastable beta titanium alloy developed by RMI Titanium Company, continues to be used in new applications due to its excellent mechanical properties and resistance to corrosion. New data in this paper include mechanical properties in large sections, cold drawn bar and welds. Fatigue crack growth and corrosion data are added to supplement previously published data.

1993-02-21

362

Plasma deposition of sealing coatings based on zirconium dioxide  

International Nuclear Information System (INIS)

Technology of plasma sputtering, structure and properties of zirconium dioxide coatings were studied. Necessity of void number increase to enhance coating heat-resistance is shown. Optimal powder particle size (20-60 #mu#m) providing optimal coating porosity was determined. Weight part of stabilizating oxide (Y_2O_3) in ZrO_2 for formation in coating of microcracks serving as barriers for macro-cracks propagation was determined.

1992-01-01

363

Phase transformation and mechanical properties of the Ti_5_0Zr_3_0Nb_1_0Ta_1_0 alloy with low modulus and biocompatible  

International Nuclear Information System (INIS)

The beta transformation characteristics and mechanical properties of the #beta# titanium alloy Ti_5_0Zr_3_0Nb_1_0Ta_1_0 in the temperature range between 200 and 900 deg. C have been studied by means of X-ray diffraction (XRD), Vickers hardness (HV), and tensile test techniques. In the as-rolled state, only #beta#-phase was identified by XRD. Upon heat-treating at 250 deg. C for 4 h, the #alpha#-phase was precipitated from the #beta#-phase matrix, and leading to an increase of Vickers hardness. A maximum HV value was observed at 400 deg. C, and then HV value decreased with increasing heat-treating temperature. Above 650 deg. C, HV value remained almost constant. During heat-treating at 300-650 deg. C, the decomposition of the metastable #beta#-phase has been found to proceed through a phase separation reaction leading to the formation of #beta#-Ti and #beta#-Zr b.c.c. solid solution phases rather than the formation of solute rich and solute lean ...

2005-04-19

364

Microscopic properties of passive films on Ti and Zr from optical, electrochemical and SXM-measurements  

International Nuclear Information System (INIS)

A combined application of several microtechniques is presented and discussed with the Ti/TiO_2 and Zr/ZrO_2-systems as an example. All measurements were carried out on single grains of technical materials in order to detect and quantify the effect of substrate microstructure on the properties of anodic passive films formed potentiodynamically in 0.5 M H_2SO_4 (dU/dt = 20 mVs"-"1). Anisotropy-micro-ellipsometry (AME) was employed to determine the crystallographic orientation of the substrate grains along with passive film thickness and crystallinity in dependence on the anodization potential. Both the isotropic (amorphous) TiO_2- and the anisotropic (crystalline) ZrO_2-films exhibit a systematic dependence of film thickness on the grain orientation. Local LASER-scanning photocurrent measurements (#lambda#=257 nm) on the same grains likewise show a heterogeneity of the photoelectrochemical reactivity in all cases. This is quantitatively explained ...

1998-03-01

365

Investigation of the hydrogen desorption properties of Mg + 10 wt.%X (X V, Y, Zr) submicrocrystalline composites  

International Nuclear Information System (INIS)

The effects of catalytic metal additives on the hydrogen desorption properties of the submicrocrystalline magnesium hydride (#beta#-MgH_2) formed after hydrogenation of the Mg + 10 wt.%X (X = V, Y, Zr) mechanically (ball) milled composites were studied. The composites with catalytic metals were processed by controlled mechanical milling (CMM) in the magneto-mill Uni Ball Mill 5 under protective Ar atmosphere. X-ray diffraction of the milled powders revealed the formation of Mg nanograins (50-60 nm range) interdispersed with the nanograined metal additives within the powder particles. Scanning electron microscopy showed particle size reduction after milling. After activation and hydrogenation in a Sieverts-type apparatus under about 2 MPa pressure of hydrogen, the tetragonal #beta#-MgH_2 hydride co-exists with the small amount of retained unreacted Mg phase and the small amount of MgO in all three composites. The #beta#-MgH_2 phase after hydrogenation is ...

2006-04-13

366

Investigation of (CeO_2)_x(Sc_2O_3)_(_0_._1_1_-_x_)(ZrO_2)_0_._8_9 (x = 0.01-0.10) electrolyte materials for intermediate-temperature solid oxide fuel cell  

International Nuclear Information System (INIS)

Oxide ionic conductivities of (CeO_2)_x(Sc_2O_3)_(_0_._1_1_-_x_)(ZrO_2)_0_._8_9 (x = 0.01-0.10) electrolytes were optimized for the application in intermediate-temperature solid oxide fuel cell (IT-SOFC). Powders with different contents of CeO_2 and Sc_2O_3 were prepared via a co-precipitation method. The obtained powders and pellets were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and impedance spectroscopy. Among all the compositions, (CeO_2)_0_._0_4(Sc_2O_3)_0_._0_7(ZrO_2)_0_._8_9(4Ce7ScZr) gives the highest ionic conductivity of 0.065 S cm"-"1 at 800 "oC. The effects on densification and electrical properties of different sintering additives, such as SiO_2, MgO, Co_3O_4, MoO_3 and Bi_2O_3, were studied and different conducting behavior with these additives were observed. The densification temperatures of CeO_2 and Sc_2O_3 co-doped electrolytes can be ...

2010-07-23

367

Integral testing of the evaluated data files for silicon, zirconium, niobium and iron  

Energy Technology Data Exchange (ETDEWEB)

The evaluated data testing for Si, Zr, Nb and Fe materials has been performed through the analyses of the neutron leakage spectrum from spherical assemblies measured in integral benchmark experiments with (d,t) and Cf fission neutron sources. Intercomparisons of the calculated from BROND-2, ENDF/B-6 and JENDL-3 data files with experimental results are presented.

1994-12-31

368

Enhanced corrosion resistance by sol-gel-based ZrO_2-CeO_2 coatings on magnesium alloys  

International Nuclear Information System (INIS)

The physical, chemical and mechanical properties of magnesium alloys make them attractive materials for automotive and aerospace applications. However, these materials are susceptible to corrosion and wear. This work discusses the potential of using sol-gel based coatings consisting of ZrO_2 and 15 wt.% of CeO_2. The CeO_2 component provides enhanced corrosion protection, while ZrO_2 impart corrosion as well as wear resistance. Coating deposition was performed by the dip coating technique on two magnesium alloy substrates with different surface finishes: AZ91D (as-casted, sand-blasted, and machined) and AZ31 (rolled and machined). All as-deposited coatings (xerogel coatings) were then subjected to 10 h annealing: a temperature of 180 C was applied to the AZ91D alloy and 140 C to the AZ31 alloy. Morphological and structural properties of the annealed coatings were investigated by scanning electron microscopy, atomic force microscopy and ...

2005-02-01

369

Effect of heat treatment on the properties of Metglas foils, and laminated magnetoelectric composites made thereof  

British Library Electronic Table of Contents (United Kingdom)

Annealing of magnetostrictive Metglas foils, subsequently incorporated into laminated Metglas/Pb(Zr, Ti)O3 magnetoelectric (ME) composites, is shown to result in improved magnetic properties, as well as ME coefficients. Annealing of the foils at 350 ?C resulted in partial crystallization, without oxidation or magnetic cluster formation that would reduce the magnetization. Laminate composites made with these annealed Metglas foils had improved ME coefficients.

2011-01-01

370

Change of crystal field in the Er(Ni,Cu)Al system  

Energy Technology Data Exchange (ETDEWEB)

The ErNi{sub 1-} {sub x} Cu {sub x} Al compounds crystallize all in the hexagonal ZrNiAl-type structure. The concentration dependence of lattice constants shows a discontinuity between x=0.5 and 0.6. This structural change has no primary impact on the magnetic order in this series, but influences the crystal field. The lower part of the crystal-field energy-level schemes has been estimated from the specific-heat data.

2007-09-15

371

Change of crystal field in the Er(Ni,Cu)Al system  

International Nuclear Information System (INIS)

The ErNi_1_- _x Cu _x Al compounds crystallize all in the hexagonal ZrNiAl-type structure. The concentration dependence of lattice constants shows a discontinuity between x=0.5 and 0.6. This structural change has no primary impact on the magnetic order in this series, but influences the crystal field. The lower part of the crystal-field energy-level schemes has been estimated from the specific-heat data.

2007-09-01

372

Carbon effect on the structure and plasticity characteristics of titanium #beta#-alloys  

International Nuclear Information System (INIS)

In this paper a study is made of the structure and mechanical properties of the #beta# alloy system Ti-Mo-Zr-Sn (the composition of which is equivalent to the #beta# III alloy used abroad) containing different amounts of carbon. Study of the #beta#-titanium alloy containing 0.1% C revealed the presence of particles of titanium carbide. Separation of the titanium carbide promotes a reduction in impact strength, an increased tendency toward cold shortness, and poorer workability. (author).

373

Beryllium armored mockups for fusion high flux application  

Energy Technology Data Exchange (ETDEWEB)

One of the main requirements to use Be as a candidate for plasma facing component in ITER is providing a reliable joint between Be and Cu-alloy heat sink structure. In this work authors present the results of recent activity on this way. To create Be/CuCrZr joints the unique fast e-beam brazing technology was developed in Russia. The numbers of Be/CuCrZr mock-ups were manufactured in Efremov Institute by fast e-beam brazing using Cu-Sn-In-Ni brazing alloy. These mock-ups were tested by Sandia Laboratory at the EBTS electron beam facility. The goals of the tests were to define the allowable dimensions of the armour tiles for the heat loads of more than 10 MW/m{sup 2}, to find the limit of bond strength for the Be/CuCrZr joint and response to heat loads and to estimate the life time of the brazed tiles by thermo-cyclic testing. The screening and thermal fatigue results are presented. With the aim to check the applicability of ...

1998-07-01

374

Analysis of titanium and zirconium in red mud with energy dispersive x-ray spectrometry  

Energy Technology Data Exchange (ETDEWEB)

An energy dispersive x-ray fluorescence technique was used for the determination of Titanium (Ti) and Zirconium (Zr) in red mud by using a standard addition method. An annular {sup 241}Am source is employed for excitation of K shells of elements. 13 refs., 2 figs., 1 tab.

1996-11-01

375

Analysis of load-penetration depth data using Oliver-Pharr and Cheng-Cheng methods of SiAlON-ZrO_2 ceramics  

International Nuclear Information System (INIS)

Depth sensing indentation tests were carried out to obtain load-penetration depth curves of SiAlON-ZrO_2 ceramics under different peak loads ranging from 200 to 1800 mN. The values of indentation hardness (H_O_P, H_C_C) and reduced elastic modulus (E_O_P, E_C_C) were calculated by using Oliver-Pharr (OP) and Cheng-Cheng (CC) methods. The experimental results revealed that the indentation hardness and reduced elastic modulus exhibit peak-load dependence, i.e. indentation size effect. Both indentation hardness and reduced elastic modulus values were obtained by considering indenter tip roundness and machine compliance. These values obtained from the OP method are higher than from the CC method. On the other hand, h_f/h_m ratios were used to clarify the indentation deformation behaviour of the SiAlON-ZrO_2 ceramic. The experimental h_f/h_m values were lower than the reported critical value (0.7) for all applied test loads, which is attributed to ...

2008-02-07

376

Observations of plasma wave turbulence generated around large ionospheric spacecraft: Effects of motionally induced EMF and of electron beam emission  

International Nuclear Information System (INIS)

The authors report on observations of plasma wave turbulence generated during electron beam injections, spacecraft potential variations, and neutral gas emissions of the CHARGE 2 sounding rocket experiment. The payload was flown in a mother/daughter configuration, with the two sub-payloads electrically connected by an insulated, conducting tether. While tethered, the two platforms were separated, drifting apart in a direction perpendicular to both the magnetic field and to the spacecraft velocity, reaching a maximum distance of 426 m at the end of the flight. The mother carried a high-voltage (HV) system (0-460 V), biasing the mother negative relative to the daughter. The operation of the HV bias system simulated the motional emf induced in larger orbiting space structures like the Tethered Satellite System 1 (TSS 1) space shuttle mission scheduled for the spring of 1992. In addition, the mother carried an electron beam accelerator (1 keV, 0-46 mA). The daughter diagnostics included ...

377

M-shell x-ray production by 0.6--4.0-MeV protons in ten elements from hafnium to thorium  

International Nuclear Information System (INIS)

M-shell x-ray production cross sections for selected heavy elements, namely, _7_2Hf, _7_3Ta, _7_4W, _7_5Re, _7_6Os, _7_7Ir, _7_8Pt, _7_9Au, _8_3Bi, and _9_0Th, were measured for protons of energy 0.6--4.0 MeV. The experimental results are compared with the predictions of the first Born and semiclassical approximations for M-shell ionization; these data are also compared with the theory that accounts for the projectile's energy loss and Coulomb deflection as well as for the target's M-shell electron perturbed stationary state and relativistic nature (ECPSSR). Generally, fair agreement between the data and the ECPSSR theory is found. Some systematical discrepancies observed for the lightest elements (Hf, Ta, and W) are explained as possible ambiguities in the M-shell Coster-Kronig factors and fluorescence yields, which were used to convert theoretical M-subshell ionization cross sections to the total M-x-ray production cross sections. The ...

378

Calculations of long-lived isomer production in neutron reactions  

Energy Technology Data Exchange (ETDEWEB)

We present theoretical calculations for the production of the long-lived isomers: {sup 121m}Sn (11/2-, 55 yr), {sup 166m}Ho(7-, 1200 yr), {sup 184m}Re(8+, 165 d), {sup 186m}Re(8+, 2{times}10{sup 5} yr), {sup 178m}Hf(16+, 31 yr), {sup 179m}Hf(25/2-, 25 d), {sup 192m}Ir(9+, 241 yr), all which pose potential radiation activation problems in nuclear fusion reactors if produced in 14-MeV neutron-induced reactions. We consider mainly (n,2n) production modes, but also (n,n{sup {prime}}) and (n,{gamma}) where necessary, and compare our results both with experimental data (where available) and systematics. We also investigate the dependence of the isomeric cross section ratio on incident neutron energy for the isomers under consideration. The statistical Hauser-Feshbach plus preequilibrium code GNASH was used for the calculations. Where discrete state experimental information was lacking, rotational band members above the isomeric state, which can be ...

1991-01-01

379

Measurement of. beta. decay energies of short-lived neutron-rich atomic nuclei in the mass range 101 less than or equal toA less than or equal to106 and A=109. Messung von Beta-Zellverfallsenergien kurzlebiger, neutronenreicher Atomkerne im Massenbereich 101 less than or equal toA less than or equal to106 und A=109  

Energy Technology Data Exchange (ETDEWEB)

Q/sub ..beta..-values are determined for 18 nuclei (Zr-, Nb-, Mo-, Tc-, Ru- and Rh-nuclides) with mass numbers 101 less than or equal toA less than or equal to106 and A=109 from measurements of beta decay energies which were carried out at the LOHENGRIN mass separator at the Institut Laue-Langevin in Grenoble (France). The given Q/sub ..beta..-values between 2 and 8 MeV show errors of about 1.5% (with the exception of /sup 103/Zr and /sup 105/Nb resp. and /sup 103/Tc for which larger errors result due to statistical resp. systematic reasons): /sup 101/Zr 5500+-70, /sup 101/Nb 4580+-45, /sup 102/Zr 4670+-40, /sup 102/Nb 7230+-70, /sup 103/Zr 6790+-240, /sup 103/ 5740+-70, /sup 103/Mo 3575+-80, /sup 103/Tc 2585+-70, /sup 104/Nb 8250+-130, /sup 104/Mo 2180+-40, /sup 104/Tc 5520+-100, /sup 105/Nb 6570+-150, /sup 105/Mo 4885+-80, /sup 105/Tc 3750+-60, /sup 106/Mo 3515+-45, /sup 106/Tc ...

1986-10-31

380

Measurement of #beta# decay energies of short-lived neutron-rich atomic nuclei in the mass range 101 #<=# A #<=# 106 and A=109  

International Nuclear Information System (INIS)

Q_#beta#-values are determined for 18 nuclei (Zr-, Nb-, Mo-, Tc-, Ru- and Rh-nuclides) with mass numbers 101 #<=# A #<=# 106 and A=109 from measurements of beta decay energies which were carried out at the LOHENGRIN mass separator at the Institut Laue-Langevin in Grenoble (France). The given Q_#beta#-values between 2 and 8 MeV show errors of about 1.5% (with the exception of "1"0"3Zr and "1"0"5Nb resp. and "1"0"3Tc for which larger errors result due to statistical resp. systematic reasons): "1"0"1Zr 5500#+-#70, "1"0"1Nb 4580#+-#45, "1"0"2Zr 4670#+-#40, "1"0"2Nb 7230#+-#70, "1"0"3Zr 6790#+-#240, "1"0"3 5740#+-#70, "1"0"3Mo 3575#+-#80, "1"0"3Tc 2585#+-#70, "1"0"4Nb 8250#+-#130, "1"0"4Mo 2180#+-#40, "1"0"4Tc 5520#+-#100, "1"0"5Nb 6570#+-#150, "1"0"5Mo 4885#+-#80, "1"0"5Tc 3750#+-#60, "1"0"6Mo 3515#+-#45, "1"0"6Tc 6540#+-#70, "1"0"9Ru 4150#+-#80, "1"0"9Rh 2550#+-#50 (all values in ...

381

Synthesis and characterization of #beta#-SiAlON with a rare earth concentrate as sintering aid  

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 ...

382

Planar excilamp on rare gas chlorides pumped by a transverse self-sustained discharge  

Science.gov (United States)

The design and parameters of a UV-VUV spontaneous radiation source - an excilamp operating on chlorides of rare gases ArCl{sup *}, KrCl{sup *} and XeCl{sup *} in the wavelength range 175-308 nm are presented. The Ne-Xe(Kr, Ar)-HCl mixtures were excited by a high-pressure self-sustained discharge with spark preionisation. It is shown that upon pumping mixtures of rare gases and halogens by a transverse discharge, the intensities of the B-X emission band of molecules ArCl{sup *}, KrCl{sup *} and XeCl{sup *} are comparable and up to 90% of the emission energy of excilamps can be concentrated in the UV region. The peak UV power density at 222 and 308 nm on the output window of the excilamp was {approx}2 kW cm{sup -2} for the pulse energy up to {approx} 3 mJ. The output emission energy of the excilamp at 175 nm achieved {approx}0.6 mJ and the peak power density was {approx}0.4 kW cm{sup -2}. (laser applications and other topics in quantum ...

2006-02-28

383

Top quark rare three-body decays in the littlest Higgs model with T-parity  

CERN Document Server

In the littlest Higgs model with T-parity (LHT), the mirror quarks have flavor structures and will contribute to the top quark flavor changing neutral current. In this work, we perform an extensive investigation of the top quark rare three-body decays $t\\rightarrow cVV (V=\\gamma,Z,g)$ and $t\\rightarrow cf\\bar{f} (f=b,\\tau,\\mu,e)$ at one-loop level. Our results show that the branching ratios of $t\\rightarrow cgg$ and $t\\rightarrow cb\\bar{b}$ could reach $\\mathcal {O}(10^{-3})$ in the favorite parameter space of the littlest Higgs model with T-parity, which implies that these decays may be detectable at the LHC or ILC, while for the other decays, their rates are too small to be observable at the present or future colliders.

2011-01-01

384

Structure and electric transport properties of LnSr_2FeTiO_7 (Ln = La, Nd and Gd)  

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)

2011-02-01

385

Spectroscopic study of rare earth chromates: relation to the structure  

Energy Technology Data Exchange (ETDEWEB)

The luminescence spectra of trivalent europium ion embedded in various rare earth chromates were analysed. The spectroscopic data in most of chromates are in agreement with the structural determination but for some others the discrepancy between two methods is underlined. Energy level schemes were deducted from the experimental emission spectra and the crystal field simulation has been performed. The maximum splitting of the {sup 7}F{sub 1} manifold of the Eu{sup 3+} ion as a function of N{sub v}, the so-called crystal field strength parameter, is given. This allows us to classify the compounds according to their crystal field extent. (author) 11 refs, 8 figs, 2 tabs

1996-12-31

386

Microstructure-property relationships in beryllia-ceramics sintered to near theoretical density  

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.).

1989-01-01

387

Methodology for Rare Earth Element Determinations of Uranium Oxides by Ion Microprobe  

British Library Electronic Table of Contents (United Kingdom)

A methodology for the determination of the rare earth elements in uranium oxides by ion microprobe has been set up on a Cameca ims-3f instrument. An uranium oxide reference material from a syn-metamorphic uranium deposit related to albitisation has also been developed for this type of analysis. Applications of the methodology are presented for a series of uranium oxides selected from some major uranium deposit types: from the world's highest grade unconformity-related uranium deposit from the Athabasca Basin (Saskatchewan, Canada; the Shea Creek and the McArthur River examples), a perigranitic vein-type deposit (Pen Ar Ran, Vendee, France) and a volcanic caldera-related deposit (Streltsovkoye, Transbaikalia, Russia). Each type of uranium deposit appears to have a specific REE signature. Al...

2007-01-01

388

Investigation and analytical use of rare earth ionic associates with benzilic acid and rhodamine B  

International Nuclear Information System (INIS)

Ions of rare earth elements (r.e.e.) have been found to form with benzilic acid and rhodamine B precipitates hardly soluble in water and extractable by toluene. The conditions of La and Pr determination by extraction-spectrophotometry method are studied. Relative square deviation does not exceed 0.027 and 0.034 respectively. The method can be used for determination of other cerium sub-group r.e.e. in their salts and cannot be employed for determination of lighter r.e.e. in the presence of heavier r.e.e., because the latter form low soluble precipitates capturing the r.e.e. situated in the beginninq of the r.e.e. series.

1977-01-01

389

Intracranial Dural Metastasis of Ewing's Sarcoma: a Case Report  

International Nuclear Information System (INIS)

Ewing's sarcoma is a malignant bone tumor that can occur anywhere in the body, but it is most commonly observed in the long bones of the arms and legs, the pelvis and in the chest. The predominant sites of metastasis include the lung (38%), bone (including the spine; 31%), and the bone marrow (11%). Metastasis of Ewing's sarcoma to the central nervous system (CNS) is relatively rare, and most of the previous reports have demonstrated involvement of the bony calvarium or brain parenchyma. We describe here the imaging findings of dural metastasis of Ewing's sarcoma, and these imaging findings have not been previously reported on in the medical literature. In conclusion, dural metastasis of Ewing's sarcoma is very rare and its imaging characteristics are similar to those of a primary tumor, which mimic the findings of a schwannoma or meningioma. Despite its rarity, secondary Ewing's sarcoma may be included in the differential diagnosis of ...

2008-02-01

390

Hepatosplenic T-cell lymphoma is a distinct rare entity: Diagnosis by fine-needle aspiration cytology  

British Library Electronic Table of Contents (United Kingdom)

Abstract In this brief report, we have described the fine-needle aspiration cytology (FNAC) of a hepatosplenic T-cell lymphoma (HSTCL) in a 60-year-old female patient. The patient complained of fever and heaviness of left upper abdomen. Ultrasound-guided FNAC of the spleen showed immature lymphoid cells, and a diagnosis of primary non-Hodgkin lymphoma of spleen was offered. Subsequently, the patient underwent splenectomy and wedge biopsy of liver that confirmed the cytological diagnosis. The lymphoma cells were positive for CD3 immunostain. Primary hepatosplenic T-cell lymphoma is a rare entity and may often pose diagnostic problems on FNAC. Diagn. Cytopathol. 2010. 2010 Wiley-Liss, Inc.

2011-01-01

391

Hemidiaphragmatic paralysis in preterm neonates: a rare complication of peripherally inserted central catheter extravasation  

British Library Electronic Table of Contents (United Kingdom)

Unilateral diaphragmatic paralysis was diagnosed in 2 preterm neonates born at 29 and 25 weeks of gestation, respectively. In both instances, the pathophysiology was phrenic nerve injury after extravasation of parenteral nutrition fluid. Misplacement and infection were predisposing factors. Diaphragmatic movement analysis by time-motion-mode ultrasonography was helpful in achieving a diagnosis. The first neonate required a diaphragmatic placation, whereas the other infant was managed nonoperatively. These cases confirm a rare etiology of diaphragmatic paralysis and possible spontaneous recovery. In neonates with very low birth weight, general anesthesia and thoracic surgery may be associated with a high morbidity, suggesting that nonoperative medical treatment, when possible, is preferable...

2011-01-01

392

Enhanced catalytic activity of Fe bimetallic modified PAN fiber complexes prepared with different assisted metal ions for degradation of organic dye  

British Library Electronic Table of Contents (United Kingdom)

Two transition metal ions (Cu^2^+ and Co^2^+) and two rare earth metal ions (Ce^3^+ and La^3^+) were used as the assisted metal ions, respectively to prepare the transition metal and rare metal assisted Fe bimetallic amidoximated polyacrylonitrile (AO-PAN) fiber complexes. And their coordination configuration and visible light adsorption properties were examined by coordination number determination and UV-vis-DRS. Then the catalytic performance of these complexes was evaluated as the heterogeneous Fenton catalysts in Rhodamine B degradation by changing the nature and dosage of the assisted ions added. The results indicated that the incorporation of the assisted metal ions led to Fe bimetallic AO-PAN complexes with the more unsaturated configurations than Fe monometallic AO-PAN complex due ...

2011-01-01

393

Determination of rare earths in eluates after chromatographic separation  

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.

1977-01-01

394

Concurrent immune thrombocytopenic purpura and Guillain-Barre syndrome in a patient with Hashimotos thyroiditis  

British Library Electronic Table of Contents (United Kingdom)

Immune thrombocytopenic purpura (ITP), Guillain-Barre syndrome (GBS), and Hashimotos thyroiditis (HT) are autoimmune disorders caused by impaired self-tolerance mechanisms triggered by interaction between genetic and environmental factors. ITP is an immune-mediated destruction of platelets resulting in mucocutaneous bleeding, GBS is an ascending motor paralysis caused by an inflammatory demyelination of peripheral nerves, and HT is characterized by autoimmune-mediated destruction of the thyroid gland. The concurrent development of ITP and GBS has only rarely been reported in the literature, and GBS itself rarely occurs with other autoimmune disorders. We present a 21 year-old patient with known Hashimotos hypothyroidism that simultaneously developed GBS and ITP after an upper respiratory t...

2007-01-01

395

V{sub 2}O{sub 5}-ZrO{sub 2} catalysts for the oxidative dehydrogenation of propane - influence of the niobium oxide doping  

Energy Technology Data Exchange (ETDEWEB)

The oxidative dehydrogenation (ODH) of light alkanes is an alternative way for the production of olefins. A wide variety of catalytic systems has been investigated. Vanadium oxide based catalysts were described in the literature as effective catalysts for the ODH of propane. The catalytic activity and selectivity depend on the kind of support material, the kind of dopants and the formation of complex metal oxide phases. In recent papers it was claimed that both orthovanadate and/or pyrovanadate species are selective for the ODH of propane. Niobia based materials were investigated as catalysts for acidic and selective oxidation type reactions. In the ODH of propane niobia exhibited a high selectivity to propene but the conversion of propane was low. V{sub 2}O{sub 5}-Nb{sub 2}O{sub 5} catalysts proved to be catalytically active and selective and showed no formation of oxygenates. In the present study the influence of the niobia dopant of the catalytic properties of V{sub 2}O{sub ...

1998-12-31

396

The effect of annealing parameter on corrosion resistance of Zircaloy-2  

International Nuclear Information System (INIS)

The effects of equal #SIGMA#Ai for different combinations of the annealing temperature and annealing time on corrosion resistance and evolution of precipitates of Zircaloy-2 were investigated. Nodular corrosion resistance in the out-of-pile corrosion test was degraded with increasing #SIGMA#Ai only when it was increased by extending the annealing time at 894 K but did not depend on #SIGMA#Ai which was increased by raising the annealing temperature for a constant annealing time of 2.5 h. Extensive observation and micro-analysis of precipitates by analytical electron microscope (AEM) suggested the cause of degradation of nodular corrosion resistance to be the remarkable increase in volume fraction of Si-containing precipitates such as Zr_3Si and Zr_2Si, which were observed more frequently in large #SIGMA#Ai only when it was increased by extending the annealing time at 894 K. On the other hand, uniform corrosion resistance was improved with ...

397

Synthesis of nanocrystalline YSZ (ZrO_2-8Y_2O_3) powder by polymerized complex method  

International Nuclear Information System (INIS)

In this study nanocrystalline powders of yttria-stabilized zirconia (ZrO_2-8Y_2O_3) have been synthesized through 'polymerized complex method'. Zirconium chloride, yttrium nitrate, citric acid and ethylene glycol were polymerized at 80 "oC to produce a gel-like mass in which metallic ions were uniformly distributed. During the thermal treatment of dried gel, nanocrystalline powder was formed at 450 "oC and 650 "oC for 2 h. Thermal reactions and crystalline phase formation of the dried gel were investigated through thermal analysis and X-ray diffraction analysis, respectively. The results of thermal analysis and XRD showed the formation of nanocrystalline powder at less than 600 "oC. Chemical bonding of the dried gel was investigated by Fourier transform infrared spectroscopy analysis. Morphology of powder calcined at 650 "oC was analyzed by scanning electron microscope. Yttria-stabilized zirconia powders with the mean crystallite size of 6 nm were prepared ...

2010-02-18

398

Synthesis and characterization of Al{sub 2}O{sub 3}/ZrO{sub 2}, Al{sub 2}O{sub 3}/TiO{sub 2} and Al{sub 2}O{sub 3}/ZrO{sub 2}/TiO{sub 2} ceramic composite particles prepared by ultrasonic spray pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Fine ceramic particles of zirconia toughened alumina (ZTA), titania toughened alumina (TTA), and zirconia-titania toughened alumina (ZTTA) have been synthesized by ultrasonic spray pyrolysis (USP) at various temperatures from starting salt solutions of various compositions aiming for the development of catalytic material. These particles were characterized for properties such as shape, size and size distribution, diffraction pattern, and chemical and phase composition of elements by scanning electron microscopy (SEM), particle size analyzer (PSA), x-ray diffraction (XRD), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Chemical compositions and sizes of ceramic composites have been controlled by the stoichiometry of salt solutions and the flow rate of spraying solutions. The optimum experimental conditions for the various composite particle synthesis have been proposed.

2002-08-01

399

Synthesis and characterization of Al_2O_3/ZrO_2, Al_2O_3/TiO_2 and Al_2O_3/ZrO_2/TiO_2 ceramic composite particles prepared by ultrasonic spray pyrolysis  

International Nuclear Information System (INIS)

Fine ceramic particles of zirconia toughened alumina (ZTA), titania toughened alumina (TTA), and zirconia-titania toughened alumina (ZTTA) have been synthesized by ultrasonic spray pyrolysis (USP) at various temperatures from starting salt solutions of various compositions aiming for the development of catalytic material. These particles were characterized for properties such as shape, size and size distribution, diffraction pattern, and chemical and phase composition of elements by scanning electron microscopy (SEM), particle size analyzer (PSA), x-ray diffraction (XRD), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Chemical compositions and sizes of ceramic composites have been controlled by the stoichiometry of salt solutions and the flow rate of spraying solutions. The optimum experimental conditions for the various composite particle synthesis have been proposed.

2002-08-01

400

Superconducting and optical properties of #alpha#-zirconium from its augmented-plane-wave band structure  

International Nuclear Information System (INIS)

The detailed electronic energy band structure of hexagonal close-packed #alpha#-zirconium, corresponding to the atomic configuration of 4d"25s"2 of its four outermost valence electrons, has been computed by the composite-wave variational version of the augmented-plane-wave(APW) method in conjunction with the X#alpha#(#alpha# = 0.70424) exchange approximation for obtaining the potentials. From these data the electronic density of states and its angular-momentum-decomposed components have been obtained by the Raubenheimer-Gilat method. These quantities are required in order to calculate the electron-phonon interaction parameter (lambda) and the superconducting transition temperature (Tsub(c)) within the framework of the theories of Gaspari and Gyorffy and McMillan. A study of the variation of Tsub(c) with the Coulomb pseudopotential (#mu#*) revealed that #mu#* = 0.1 yields the best agreement between theory and experiment for #alpha#-Zr. Also studied from the energy ...

401

Spectral dependence of ultrasonic attenuation for hydrided Zr-2.5%Nb Alloy  

International Nuclear Information System (INIS)

The cold-worked Zr-2.5%Nb alloy is used as material for the pressure tubes in CANDU nuclear reactors. During the service life in reactor, diffusion of hydrogen and/or deuterium in the pressure tubes wall occur. Below a certain temperature, a stable hydride of zirconium is formed, as a brittle phase which can lead to catastrophic failures. For this reason, it is very important to be able to investigate the hydrogen effect on the micro structural properties of zirconium alloys. In the present paper a non-destructive testing technique is used, known as ultrasonic spectral analysis. When an ultrasonic signal traverses a medium, the frequency components associated with the input signal are altered. By frequency analysing the reflected signals, it is possible to study and compare the material properties. The two major parameters measured in ultrasonic spectroscopy are the attenuation and the velocity of the waves. Attenuation is determined by the energy losses in ...

2009-10-12

402

Removal of phosphate by mesoporous ZrO{sub 2}  

Energy Technology Data Exchange (ETDEWEB)

A type of mesoporous ZrO{sub 2} was synthesized and its phosphate removal potential was investigated in this study. The adsorption isotherm, pH effect, ionic strength effect and desorption were examined in batch experiments. The adsorption data fitted well to the Langmuir model with which the maximum P adsorption capacity was estimated to be 29.71 mg P/g. The amount of phosphate adsorbed increased rapidly in the first 5 h and slowly towards the end of the run, suggesting the possible monolayer coverage of phosphate ions on the surface of the adsorbent. The phosphate adsorption tended to increase with a decrease of pH and an increase of ionic strength. A phosphate desorbability of approximately 60% was observed with 0.5 M NaOH, which indicated a relatively strong bonding between the adsorbed PO{sub 4}{sup 3-} and the sorptive sites on the surface of the adsorbent. The immobilization of phosphate probably occurs by the mechanisms of ion exchange and physicochemical ...

2008-03-01

403

Observation of high permittivity in Ho substituted BaZr_0_._1Ti_0_._9O_3 ceramics  

International Nuclear Information System (INIS)

The authors observed an extremely high permittivity (#approx#35 000 at T_C) in barium zirconate titanate (BaZr_0_._1Ti_0_._9O_3) ceramics with holmium substitution (1-5 mol %) in Ba site. Careful microstructural investigation and energy dispersive spectroscopy analysis of the 1-2 mol % of Ho substituted ceramics showed the enrichment of a Ho-phase along the grain boundaries with a composition close to the Ho_2Ti_2O_7 pyrochlore. The formation of Ho rich phase resulted in the Maxwell-Wagner polarization mechanism, which leads to this unusually high permittivity. Ceramics with 3 mol % or higher Ho content showed lesser permittivity values compared to 1-2 mol %, probably due to the increase in pyrochlore phase. These high dielectric constant ceramics are useful in nanoscale devices.

2007-07-09

404

Near infrared to red and yellow to blue upconversion emissions from Pr"3"+: ZrF_4-BaF_2-LaF_3-YF_3-AlF_3-NaF glasses  

International Nuclear Information System (INIS)

This paper describes the development and a detailed analysis carried out on the luminescence characteristics of Pr"3"+ doped ZrF_4-BaF_2-LaF_3-YF_3-AlF_3-NaF glasses. In the present work our objectives are to elucidate the possible mechanisms that are responsible for NIR to red upconversion process and yellow to blue upconversion emission in terms of energy level schemes from the praseodymium containing fibre optical glass composition. We have studied their different physical and optical properties. Besides our investigation on the upconversion emission of these glasses, normal fluorescence studies have also been undertaken in explaining the mechanisms in demonstrating bright red and blue emissions upon excitations at visible and UV wavelengths. Besides these measurements works, a bright blue colour emission was observed under an UV source (202 nm) and upconverted prominent red emissions were observed with a laser diode (LD of 980 nm). Similarly under a yellow ...

2004-04-15

405

Microstructure modifications and modulated piezoelectric responses in PLZT/Al{sub 2}O{sub 3} composites  

Energy Technology Data Exchange (ETDEWEB)

Piezoelectric ceramics for acoustic applications have been prepared by mixing the piezoelectric phase Pb{sub 1-1.5x}La{sub x}{open_square}{sub x/2}(Ti{sub 1-y}Zr{sub y})O{sub 3} (PLZT) with variable fractions of Al{sub 2}O{sub 3}. The samples are in form of pellets and polarized at high temperature. After thermal treatment, X-ray diffraction and scanning electron microscopy have been used to determine the phase and morphological modifications. The morphotropic PLZT initial phase disproportionates into modified PLZT and ZrO{sub 2} phases. Using electrical impedance spectroscopy, the resonance frequencies of the composite system have been determined and analyzed. As the Al{sub 2}O{sub 3} volume fractions increase, the resonance frequency and the amplitude of the electrical response both decrease. An interpretation of the role of Al{sub 2}O{sub 3} additions is proposed in terms of phase and microstructure modifications. Using LRC electrical ...

2003-01-15

406

Microstructure and crack propagation in Ti-3Al-8V-6Cr-4Mo-4Zr  

International Nuclear Information System (INIS)

Fatigue-crack growth in air and in aqueous 3.5-percent NaCl as well as fracture toughness are evaluated for the metastable beta-titanium alloy Ti-3Al-8V-6Cr-4Mo-4Zr in various microstructural conditions. Two solution heat treatments (SHT), 800 C and 927 C, were chosen to produce two different grain sizes. Approximately 20 vol pct unrecrystallized beta grains remained after SHT at the lower temperature. Yield stresses were 895 and 850 MPa, respectively. Both simplex and duplex aging treatments were performed for both grain sizes to vary the distribution of alpha precipitates while keeping the yield stress in the range of 1075-1220 MPa for all aged conditions. Unaged material exhibits significantly higher fracture toughness levels than aged material. The unrecrystallized regions were associated with a loss in ductility and toughness. 21 refs.

1990-10-07

407

Interaction of tetravalent plutonium and zirconium with citric acid in nitric acid solutions  

Science.gov (United States)

The interaction of Pu(IV) and Zr(IV) with citric acid in nitric acid solutions (C/sub HNO/sub 3// greater than 0.1 M) of lithium nitrate was studied by the distribution method in the interval of nitrate ion concentrations from 1 to 6 g-eq/liter. A 40 percent solution of TBP in decane was used as the extraction reagent. It was established that within the range of concentrations studied, complex compounds of plutonium and zirconium are formed: PuHCit/sup 2 +/ and ZrH/sub 2/Cit/sup 3 +/. The concentration equilibrium constants of the reactions of formation of these compounds retain a constant value at constant ionic strength and undergo substantial variation when the total concentration of the nitrate ion in solution is varied. The values of the effective equilibrium constants, calculated considering the change in the activity coefficient of the hydrogen ion, retain a constant value within a wide range of nitrate ion concentrations. It was shown ...

1975-01-01

408

Hydrothermal synthesis of semiconductive PZT solid solutions and electromechancal properties of sintered bodies. Suinetsuho ni yoru handosei PZT koyotai no gosei to shoketsutai no denki kikaiteki seishitsu  

Energy Technology Data Exchange (ETDEWEB)

Semiconductive crystalline PZT powders doped with Bi and K were synthesized by hydrothermal reaction at 200{degree}C for 48 hours. The synthesis of the crystalline powders became difficult with an increase in doped amount of Bi and K, and in Zr/(Ti+Zr) ratio. Since substantial amounts of Pb remained in solution after hydrothermal reaction, the addition of Pb in excess of 25% was necessary to obtain the stoichiometric composition of the PZT solid solution. Bi contents in the powders were identical to those in starting materials, while K contents were less than expected ones. The electromechanical properties of the sintered bodies could be precisely measured by an admittance-curve-fitting method. The electromechanical coupling factor and piezoelectric coefficient of the sintered bodies varied with the Bi content like those of specimens prepared by solid state reaction, and showed the maximum values at a given Bi content. However, the change in conductivity with the ...

1989-10-01

409

Ground-state properties of exotic nuclei near Z=40 in the relativistic mean-field theory  

International Nuclear Information System (INIS)

Study of the ground-state properties of Kr, Sr and Zr isotopes has been performed in the framework of the relativistic mean-field (RMF) theory using the recently proposed relativistic parameter set NL-SH. It is shown that the RMF theory provides an unified and excellent description of the binding energies, isotope shifts and deformation properties of nuclei over a large range of isospin in the Z=40 region. It is observed that the RMF theory with the force NL-SH is able to describe the anomalous kinks in isotope shifts in Kr and Sr nuclei, the problem which has hitherto remained unresolved. This is in contrast with the density-dependent Skyrme-Hartree-Fock approach which does not reproduce the behaviour of the isotope shifts about shell closure. On the Zr chain we predict that the isotope shifts exhibit a trend similar to that of the Kr and Sr nuclei. The RMF theory also predicts shape coexistence in heavy Sr isotopes. Several dramatic shape ...

410

Grain boundary mobility in Y{sub 2}O{sub 3}: defect mechanism and dopant effects  

Energy Technology Data Exchange (ETDEWEB)

The effects of the dopants, Mg{sup 2+}, Sr{sup 2+}, Sc{sup 3+}, Yb{sup 3+}, Gd{sup 3+}, La{sup 3+}, Ti{sup 4+}, Zr{sup 4+}, Ce{sup 4+}, and Nb{sup 5+}, on the grain boundary mobility of dense Y{sub 2}O{sub 3} have been investigated from 1,500 to 1,650 C. Parabolic grain growth has been observed in all cases over a grain size from 0.31 to 12.5 {micro}m. Together with atmospheric effects, the results suggest that interstitial transport is the rate-limiting step for diffusive processes in Y{sub 2}O{sub 3}, which is also the case in CeO{sub 2}. The effect of solute drag cannot be ascertained but the anomalous effect of undersized dopants (Ti and Nb) on diffusion enhancement, previously reported in CeO{sub 2}, is again confirmed. Indications of very large binding energies between aliovalent dopants and oxygen defects are also observed. Overall, the most effective grain growth inhibitor is Zr{sup 4+}, while the most potent grain growth promoter is ...

1996-07-01

411

Grain boundary mobility in Y_2O_3: defect mechanism and dopant effects  

International Nuclear Information System (INIS)

The effects of the dopants, Mg"2"+, Sr"2"+, Sc"3"+, Yb"3"+, Gd"3"+, La"3"+, Ti"4"+, Zr"4"+, Ce"4"+, and Nb"5"+, on the grain boundary mobility of dense Y_2O_3 have been investigated from 1,500 to 1,650 C. Parabolic grain growth has been observed in all cases over a grain size from 0.31 to 12.5 microm. Together with atmospheric effects, the results suggest that interstitial transport is the rate-limiting step for diffusive processes in Y_2O_3, which is also the case in CeO_2. The effect of solute drag cannot be ascertained but the anomalous effect of undersized dopants (Ti and Nb) on diffusion enhancement, previously reported in CeO_2, is again confirmed. Indications of very large binding energies between aliovalent dopants and oxygen defects are also observed. Overall, the most effective grain growth inhibitor is Zr"4"+, while the most potent grain growth promoter is Sr"2"+, both at 1.0% concentration.

412

Effect of Sintering Atmosphere on the Microwave Dielectric Properties and Far-Infrared Reflectivity Spectra of the (Zr{sub 0.8}Sn{sub 0.2})TiO{sub 4} Ceramics  

Energy Technology Data Exchange (ETDEWEB)

Microwave dielectric properties and far-infrared reflectivity spectra of (Zr{sub 0.8}Sn{sub 0.2})TiO{sub 4} ceramics with 1.0mol.% Sb{sub 2}O{sub 5} or WO{sub 3} were investigated in the various sintering atmospheres. The Q{center_dot}f value of the specimens sintered in oxygen atmosphere was enhanced due to the decrease of lattice anharmonic interaction resulting from the decrease of oxygen vacancies, whereas the dielectric constants remained constant regardless of sintering atmosphere. The effects of the sintering atmosphere on the changes of ionic and electronic polarization and the intrinsic microwave losses of the specimens were investigated by using the infrared reflectivity spectra from 50 to 4000cm{sup -1}, which were evaluated using Kramers-Kronig analysis and classical oscillator model. The relative tendency of microwave dielectric properties of the specimens calculated from the reflectivity data was in good agreement with the results by the post-resonant ...

2000-02-01

413

Dielectric properties of fluxed barium titanate ceramics with zirconia additions  

Energy Technology Data Exchange (ETDEWEB)

BaTiO{sub 3} compacts, when fluxed with {lt} 2 vol% of a complex borate glass phase, were sintered to near theoretical density at temperatures {lt} 1175{degrees}C in 2 h. Microstructural analysis showed a uniform grain size {lt} 1.0 {mu}m with 0.75 wt% ZrO{sub 2} added to the flux phase as a grain growth inhibitor. TEM analysis revealed a microcrystalline grain-boundary phase with the ZrO{sub 2} resident along the grain boundaries. These samples displayed an essentially flat dielectric profile, low dissipation factors ({lt} 2%) over the range 25{degrees} to 125{degrees}C, a near linear dependence ({approx} {+-} 15%) between 25{degrees} and {minus} 55{degrees}C, and significantly increased voltage stability. X-ray diffraction analysis of these small-grained materials indicates a suppression of the tetragonal structure toward a more cubic modification.

1990-03-01

414

Dielectric properties of fluxed barium titanate ceramics with zirconia additions  

International Nuclear Information System (INIS)

BaTiO_3 compacts, when fluxed with < 2 vol% of a complex borate glass phase, were sintered to near theoretical density at temperatures < 1175 degrees C in 2 h. Microstructural analysis showed a uniform grain size < 1.0 #mu#m with 0.75 wt% ZrO_2 added to the flux phase as a grain growth inhibitor. TEM analysis revealed a microcrystalline grain-boundary phase with the ZrO_2 resident along the grain boundaries. These samples displayed an essentially flat dielectric profile, low dissipation factors (< 2%) over the range 25 degrees to 125 degrees C, a near linear dependence (#approx# #+-# 15%) between 25 degrees and - 55 degrees C, and significantly increased voltage stability. X-ray diffraction analysis of these small-grained materials indicates a suppression of the tetragonal structure toward a more cubic modification.

415

Cross-section measurements for (n, 2a) (n, p) and (n, #alpha#) reactions on strontium isotopes at the neutron energy about 14 MeV  

International Nuclear Information System (INIS)

Cross-sections for "8"4Sr(n, 2n)"8"3Sr, "8"6Sr(n, 2n)"8"5"mSr, "8"6Sr(n, 2n)"8"5Sr, "8"8Sr(n, 2n)"8"7"mSr, "8"4Sr(n, p)"8"4Rb, "8"6Sr(n, p)"8"6Rb, "8"8Sr(n, p)"8"8Rb and "8"8Sr(n, #alpha#)"8"5"mKr reactions have been measured at neutron energies from 13.5 to 14.6 MeV using activation technique and by means of #gamma#-ray spectrometry. The neutron flux was determined using the monitor reaction "9"3Nb(n, 2n)"9"2"mNb and the neutron energies were measured by the method of cross-section ratios for "9Zr(n, 2n)"8"9Zr to "9"3Nb (n, 2n)"9"2"mNb reactions. The results of present work are compared with data published previously.

2006-01-01

416

Cross section measurement for "2"0"4Pb(n,2n)"2"0"3Pb and "2"0"6Pb(n, #alpha#)"2"0"3Hg reactions  

International Nuclear Information System (INIS)

The cross sections of "2"0"4Pb(n,2n)"2"0"3Pb and "2"0"6Pb(n, #alpha#)"2"0"3Hg reactions have been measured by using the activation method in the neutron energy range of 13.50-14.81 MeV. Neutron fluence dose was calibrated with the cross sections of "2"7Al(n, #alpha#)"2"4Na reaction and neutron energies were determined by using the cross section ratios of "9"0Zr(n,2n)"8"9"m"+"gZr to "9"3Nb(n,2n)"9"2"mNb reactions. The results obtained are compared with the published data.

417

Composites in the TiC-TiYTZP system  

International Nuclear Information System (INIS)

Ceramic matrix composites in the TiC-Ti, Y-TZP system can be synthesized by the reaction between carbon and the TiO_2-Y_2O_3-ZrO_2 solid solution nanopowder. This method results in the more homogeneous powders than those prepared by the physical mixing of TiC and zirconia s.s. powders. Twelve TiO_2-Y_2O_3-ZrO_2 solid solution nanopowders differing in the proportions of the constituent oxides were prepared by the coprecipitation- calcination route. They were reacted with the pyrolytic carbon evenly distributed within the system. Carbon was introduced by the thermal decomposition of the phenol-formaldehyde resin dissolved in ethyl alcohol and mixed with the zirconia s.s. nanopowder. Reaction was performed in vacuum. Compacts of the composite powders sintered in vacuum give dense materials of evenly distributed TiC inclusions of sizes not surpassing 400 nm. Hardness of such materials was dependent on their chemical and phase composition but was ...

2003-09-25

418

Workshop on NN Bremsstrahlung and Polarization Observables  

Science.gov (United States)

The traveler participated in the discussions about the physics that can be learned in the experiments being planned, those presently running, or those recently completed by a growing number of major laboratories in Europe and the USA at the 'Workshop on NN Bremsstrahlung and Polarization Observables', where many representatives of these experimental programs were present. The traveler's research in this field is supported by a DOE Grant, and she has pioneered the early theoretical NN(lambda) treatments. In addition, she visited the Vrije University to collaborate with Professor Henk Blok on proton scattering from Zr-90 and neighboring nuclei. The traveler also visited NIKEF and discussed possible future experiments of mutual interest to be done at that laboratory.

1993-01-01

419

Structural transformations of metastable #alpha#''-phase during cold deformation  

International Nuclear Information System (INIS)

Phase transformations occuring during cold deformation in hardened #alpha#+#beta# titanium alloy of the Ti-Al-Mo-Zr-Sn-Si system with 10% summary content of alloying elements are studied by X-ray diffraction analysis. Two stages of trapsformation of metastable #alpha#''-phase are found. A conclusiop is made that ability of the alloy containing #alpha#''-phase to cold deformation is determined by the presence of favourable texture, by high degree of metastability and by volume portion of #alpha#''-phase in the alloy structure.

420

Stress corrosion cracking susceptibility of #beta# titanium alloy 38-6-44  

International Nuclear Information System (INIS)

The threshold stress intensities for stress corrosion crack propagation in beta titanium alloy 38-6-44, Ti3Al-8V-6Cr-4Mo-4Zr, has been determined in salt water and methanolic solutions. The alloy was immune to stress corrosion cracking (SCC) in aqueous sodium chloride solutions (marine atmosphere). However, in methanolic solutions, the alloy was very susceptible to SCC. This marked susceptibility in methanolic solutions can be mitigated by the addition of an inhibitor: sodium nitrate. Crack extension in the alloy was transgranular and failure occurred by brittle quasi-cleavage in methanolic solutions.

421

Particle-hole excitations in N=50 nuclei  

Energy Technology Data Exchange (ETDEWEB)

Energy levels in N=50 nuclei are calculated allowing single-particle excitations from the p{sub 1/2} and g{sub 9/2} shells into the d{sub 5/2}, s{sub 1/2}, d{sub 3/2}, and g{sub 7/2} shells. Important parts of the interaction are determined by least-squares fits to known levels. Agreement with experiment is very good. The high-spin particle-hole states appear to be mainly yrast levels in mass 93 and higher, but are not in {sup 90}Zr. {copyright} {ital 1997} {ital The American Physical Society}

1997-03-01

422

Neutron cross section measurements using the Oak Ridge electron linear accelerator  

Energy Technology Data Exchange (ETDEWEB)

During this reporting period, the work supported under DOE Grant No. FG02-87ER40326.A003 has resulted in one publication, two papers submitted to Phys. Rev. C for publication, and one paper presented at a professional meeting. During this period, modifications were made to the interactive R-Matrix fitting computer program DSIG to include the total radiation widths in the R-Matrix calculation of the cross section. The R-Matrix analyses of n+{sup 90}Zr and n+{sup 208}Pn have already begun.

1990-08-01

423

Neutron cross section measurements using the Oak Ridge Electron Linear Accelerator  

Energy Technology Data Exchange (ETDEWEB)

During this reporting period the work supported by the US Department of Energy Grant No. DE-FG02-87ER40326.A005 has resulted in two publications and two papers presented at professional meetings. The neutron scattering measurement for this budget period has been completed along with scattering measurements for carbon {sup 88}Sr, {sup 40}Ar, {sup 90}Zr, {sup 208}Pb, {sup 40}Ca and {sup 28}Si. The carbon scattering yield serves to define the detector efficiencies. The silicon sample was available and is of importance in both nuclear physics and reactor physics.

1992-06-01

424

Nanocrystalline and policrystalline phases present in the protective metalloceramic coatings  

International Nuclear Information System (INIS)

New data about the structure of high-temperature resistant metalloceramic plasma sprayed coatings in micro and nano areas are presented. Application of the new instrumental methods: transmission electron microscopy combined with selected area electron diffraction mode is possible to obtain these data. The first layer in Ni based metallic bond coat shows nanocrystalline structure. External ceramic layer based on stabilised ZrO_2 is polycrystalline and contains both cubic and tetragonal crystalline phases. Local inhomogeneities in coatings phase composition are determined. (author)

2001-09-23

425

Microstructure/Mechanical property relationships in bar products of Beta-C trademark (Ti-3Al-8V-6Cr-4Mo-4Zr)  

International Nuclear Information System (INIS)

Beta-C trademark is a metastable beta titanium alloy which can be heat treated to achieve a good combination of properties such as tensile strength, fatigue strength, ductility and toughness, such as needed in aircraft fasteners. Variations in hot and cold processing parameters and solution heat treatment can affect the resultant grain structure which in turn affects subsequent aging response and mechanical properties. Several processing/heat treating routes on round bar are explored in this study to determine the effects on microstructure and various mechanical properties.

1993-02-21

426

Measurement of level lifetimes in the ps range and model interpretations for neutron-rich A {approx_equal} 100 nuclei  

Energy Technology Data Exchange (ETDEWEB)

The nuclear structure of A {proportional_to} 100 nuclei has been studied in the frame of this thesis with a recently developed {beta} - {gamma} - {gamma} triple coincidence fast timing technique and different models such as shell model, hydrodynamic model, Nilsson and particle-rotor models. This technique which allows the measurement of the level lifetimes in the ps range has been applied at JOSEF at the research reactor DIDO of KFA Juelich in studes of the short-lived neutron-rich nuclei in the A {approx_equal} 100 region. Lifetimes of level in {sup 96},{sup 98},{sup 100} ZR, {sup 99},{sup 101}-{sup 104} Nb, {sup 100}-{sup 105} Mo have been measured, which are in many cases completely new, and otherwise more precise than previously published data. From the lifetimes of the members of rotational bands, the size of the nuclear deformations has been deduced. (orig./HSI). [Deutsch] Im Rahmen dieser Doktorarbeit wurde die Kernstruktur der A {proportional_to} 100 Kerne ...

1992-08-01

427

Isospin mixing in the decay of the T/sub greater-than/ giant dipole state  

Energy Technology Data Exchange (ETDEWEB)

The magnitude of the isospin mixing in the decay of the T/sub greater-than/ giant dipole resonance has been estimated, using the (..gamma.., n) and (..gamma..,p) cross sections available for the medium-weight nuclei /sup 60/Ni, /sup 88/Sr, /sup 89/Y, /sup 90/Zr, and /sup 92/Mo. The deduced values show a fair correspondence with the existing data for mixing between compound states. From these results the mean mixing Coulomb matrix elements between compound states could also be derived.

1984-10-01

428

Interpretation of neutron activation cross-sections with pre-equilibrium consideration  

International Nuclear Information System (INIS)

The aim of the present is to consider the influence of pr equilibrium processes on the activation cross-sections of "2"7 Al(n,p) "2"7 Mg, "5"1 V(n,p) "5"1"m Ti, "8"8 Sr(n,p) "8"8"m Rb, "9"4 Zr(n,p) "9"4"m Y and "9"7"Mo(n,p) "9"7"m Nb in the neutron energy range 13 to 15 MeV. Comparison with recent measurements is given for all considered isotopes. 2 figs., 1 tab.

429

Influence of the massicot Pb O in PLZT ceramics  

International Nuclear Information System (INIS)

(Pb_1_-_x La_x) (Zr_0_._6_5 Ti_0_._3_5) ceramics, with x = 0.09 (PLZT 9/65/35) were prepared using lead monoxide (Pb O) with different amount of litharge (tetragonal) and massicot (orthorhombic) phases. Results, based on x-ray diffraction patterns, remanent polarization and dielectric measurements, show that the Pb O polymorphic phase does not change the final structure of the PLZT but causes changes on the remanent polarization and dielectric permittivity temperature dependence. (author). 11 refs, 2 figs, 2 tabs.

1994-06-18

430

High octane ethers from synthesis gas-derived alcohols  

Science.gov (United States)

Catalytic testing of inorganic catalysts was continued with the highly active sulfate-modified zirconia catalyst prepared here. Using isobutanol as the only reactant over this catalyst, it was demonstrated that high conversion and selectivity to isobutene was achieved at 175[degrees]C. In addition, the high selectivity to isobutene, i.e. 79--86 mol%, was maintained at higher space velocities and higher temperatures. A high productivity of 11.35 mol isobutene was achieved at 225[degrees]C. Utilizing a methanol/isobutanol = 2/1 molar ratio reactant mixture over the ZrO[sub 2]/SO[sub 4][sup 2[minus

1992-10-01

431

Electron microscopy analysis of grain boundary structure and composition in superplastically deformed Al-Mg alloys  

Energy Technology Data Exchange (ETDEWEB)

Evaluation of grain boundary composition and structure in superplastically deformed AA5083-based alloys (Al-4.5Mg-1.6Mn-0.2Zr) was carried out in a field-emission gun transmission electron microscope (FEG-TEM). During superplastic deformation at high homologous temperatures materials undergo extensive grain boundary sliding (GBS) which creates a flow of defects in the near-boundary region. Recent literature has shown that the grain-boundary composition in Al-Mg alloys is not necessarily the same as the matrix, and that these differences can have an effect on GBS.

1996-12-31

432

Electron combinational light scattering in disordered Ti_x_-_1Fe_x alloys: theory and experiment  

International Nuclear Information System (INIS)

Theoretical description of Raman scattering in disordered alloys of Ti and Zr with transition metals of groups 5-8 of the Mendeleev Periodic System in critical range of concentrations (CRC) is given. Results of Raman scattering experiment in the system Ti_1_-_xF_x at 0.0005

433

Effect of intense plastic straining on microstructure and mechanical properties of an Al-Mg-Sc alloy  

International Nuclear Information System (INIS)

An Al-5%Mg-0.18%Mn-0.2%Sc-0.08%Zr-0.002%Be was subjected to equal-channel angular extrusion up to true strains of #approx#3 and #approx#8, that resulted in the formation of partially recrystallized and fully recrystallized structure, respectively. It was shown that the alloy with partially recrystallized structure exhibits highest strength and ductility. The material with fully recrystallized structure showed lowest fatigue crack growth rate and highest value of fracture toughness. Reasons of this unusual effect of microstructure on crack propagation resistance under fatigue are discussed.

2010-07-01

434

Distribution of 6 q functions in nuclei and quark enhancement of hard processes with deuteron emission  

International Nuclear Information System (INIS)

"2H, "4He, "1"6O, "4"0Ca, "8"0Zr, "1"4"0Yb, "2"2"4112, "3"3"6168 nuclei are invesigated in terms of flucton model. Effective numbers of nuclear fluctons and deuterons are calculated. Values of complete effective numbers of low-radius deuterons and fluctons with S=1 spin and T=0 isospin are presented. Investigation results of inclusive reactions of quasi-elastic knock-out of deuterons by fast protons are discussed. 9 refs.; 1 fig.; 1 tab.

1988-06-14

435

Charge distribution in alpha particle induced fission of "2"0"9Bi (Preprint No. NC-06)  

International Nuclear Information System (INIS)

The charge distribution in the alpha particle induced fission of "2"0"9Bi has been studied at alpha particle energy of 55.7 MeV and 58.6 MeV. The fractional cumulative yields of "9"7Zr, "9"9Mo, "1"0"1Mo and "1"1"2Pd have been determined using gamma ray spectrometry. The charge distribution have been found to be broad. (author). 4 refs., 1 ta b.

1991-02-04

436

Use of neutron activation analysis for the control of air pollution of Algiers; Utilisation de l'analyse par activation neutronique pour le controle de la pollution de l'air d'Alger  

Energy Technology Data Exchange (ETDEWEB)

The urban zone needs clean air to assure public health. To achieve this goal several filter samples were collected in different sites in Algiers city. Toxic elements such as: Na, Mg, Cl, Sc, Cr, Ti, V, Fe, Co, Cu, Zn, Se, Br, Ag, Sb, Ce, La, Hf, Ta and Hg have been measured in the filters using neutron activation analysis technique. Irradiation of filter samples and standards were carried out in Es-Salem reactor. The experimental procedure and the results are discussed. We noted during this work that the upper limit values for suspended dusts and the high concentrations for some toxic elements found are due to the weather conditions and intense road traffic around collecting sites. (authors)

2010-07-15

437

Ternary oxide nanostructures and methods of making same  

Energy Technology Data Exchange (ETDEWEB)

A single crystalline ternary nanostructure having the formula A.sub.xB.sub.yO.sub.z, wherein x ranges from 0.25 to 24, and y ranges from 1.5 to 40, and wherein A and B are independently selected from the group consisting of Ag, Al, As, Au, B, Ba, Br, Ca, Cd, Ce, Cl, Cm, Co, Cr, Cs, Cu, Dy, Er, Eu, F, Fe, Ga, Gd, Ge, Hf, Ho, I, In, Ir, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Nd, Ni, Os, P, Pb, Pd, Pr, Pt, Rb, Re, Rh, Ru, S, Sb, Sc, Se, Si, Sm, Sn, Sr, Ta, Tb, Tc, Te, Ti, Tl, Tm, U, V, W, Y, Yb, and Zn, wherein the nanostructure is at least 95% free of defects and/or dislocations.

2009-09-08

438

Synthesis of nanoporous carbon as a gas adsorbent by reverse replication process of silica template  

Energy Technology Data Exchange (ETDEWEB)

Porous carbon with high surface area and pore volume was prepared by a reverse replication process and its toluene equilibrium adsorption behavior was investigated. The preparation process of the porous carbon was composed of following sub-processes in series: synthesis and template preparation of silica gel, impregnation and polymerization of DVB monomer in silica template, carbonization of DVB polymer in a silica-polymer composite, and HF-assisted selective etching of silica in carbon-silica composite, The prepared porous carbon was nano porous and had ultrahigh specific surface area (2007 m{sup 2}/g) and large pore volume (3.07cm{sup 3}/g). The nanoporous carbon showed rapid toluene adsorption rate and good toluene adsorption capacity, compared with a commercial Y-type zeolite, In the present study, a reverse replication process to prepare nanoporous carbons will be introduced and its application potential as a gas adsorbent will be discussed. (author). 17 ...

2003-06-01

439

Studies of ultra-low energy electron-molecule collisions using very-high-n Rydberg atoms  

International Nuclear Information System (INIS)

Potassium atoms in selected high-lying np Rydberg states (80 #<=# n #<=# 400) are being used as a tool to examine electron-polar molecule collisions at ultra-low energies (#approx#80 #mu#eV - 1 meV). This energy regime has not been investigated previously and is of interest because the corresponding electron de Broglie wavelength is large, #approx#1300 - 330 Angstrom, and because the collision time is comparable to the period of molecular rotation. A variety of target molecules has been studied, including simple rotors such as HF, and more complex species such as NH_3, CH_3I, CH_2Br_2 and C_6H_5NO_2. These targets encompass a range of dipole moments and rotational behavior, but analysis of the data shows that in each case the cross section #sigma#(#epsilon#) for rotationally-inelastic electron-polar molecule scattering varies approximately as 1/#epsilon# where #epsilon# is the electron energy. Such threshold behavior is not predicted by the Born approximation ...

1993-05-16

440

Optical and mechanical properties of thermally evaporated fluoride thin films  

Energy Technology Data Exchange (ETDEWEB)

As a result of health and safety issues surrounding the use of radioactive materials on coated optical components, there has been renewed interest in coating materials whose optical and mechanical properties approach those offered by their radioactive counterparts. Due to the radioactive nature of ThF{sub 4} and its widespread use in optical coatings, the coating industry is examining other low index and non-radioactive fluorides as possible alternatives. In this paper, the authors present the results of an experimental study on the optical and mechanical properties of thermally evaporated ThF{sub 4}, DyF{sub 3}, CeF{sub 3}, LiF, HfF{sub 4}, IRX, and IRB thin films, where the materials were deposited at different substrate temperatures. The objective is to examine this series of fluorides under comparable deposition conditions and with respect to such material properties as: n and k, film stress, and environmental stability. The optical constants of these fluorides ...

1998-06-08

441

High-energy neutron irradiation of superconducting compounds  

International Nuclear Information System (INIS)

The effect of high-energy neutron irradiation (E greater than 1 MeV) at ambient reactor temperatures on the superconducting properties of a variety of superconducting compounds is reported. The materials studied include the A-15 compounds Nb_3Sn, Nb_3Al, Nb_3Ga, Nb_3Ge and V_3Si, the C-15 Laves phase HfV_2, the ternary molybdenum sulfide Mo_3Pb/sub 0.5/S_4 and the layered dichalcogenide NbSe_2. The superconducting transition temperature has been measured for all of the above materials for neutron fluences up to 5 x 10"1"9 n/cm"2. The critical current for multifilamentary Nb_3Sn has also been determined for fields up to 16 T and fluences between 3 x 10"1"7 n/cm"2 and 1.1 x 10"1"9 n/cm"2.

1976-03-01

442

A one-pot synthetic approach to prepare palladium nanoparticles embedded hierarchically porous TiO2 hollow spheres for hydrogen peroxide sensing  

Science.gov (United States)

A simple one-step method to fabricate hierarchically porous TiO2/Pd composite hollow spheres without any template was developed by using solvothermal treatment. Pd nanoparticles (2-5 nm) were well dispersed in the mesopores of the TiO2 hollow spheres via in-situ reduction. In our experiment, polyvinylpyrrolidone played an important role in the synthetic process as the reducing agent and the connective material between TiO2 and Pd nanoparticles. HF species generated from solvothermal reaction leaded to the formation of TiO2 hollow spheres and Ostwald ripening was another main factor that affected the size and structure of the hollow spheres. The as-prepared TiO2/Pd composite hollow spheres exhibited high electrocatalytic activity towards the reduction of H2O2. The sensitivity was about 226.72 ?A mM-1 cm-2 with a detection limit of 3.81 ?M at a signal-to-noise ratio of 3. These results made the hierarchically porous TiO2/Pd composite a promising platform for ...

2010-10-01

443

Surface modification of LiNi{sub 1/2}Mn{sub 3/2}O{sub 4} thin-films by zirconium alkoxide/PMMA composites and their effects on electrochemical properties  

Energy Technology Data Exchange (ETDEWEB)

Three kinds of surface modifications were carried out on LiNi{sub 1/2}Mn{sub 3/2}O{sub 4} thin-films to improve the charge and discharge characteristics of LiNi{sub 1/2}Mn{sub 3/2}O{sub 4} positive electrodes. Among them, Zr(OBu){sub 4}/poly(methyl methacrylate) (PMMA)-treated LiNi{sub 1/2}Mn{sub 3/2}O{sub 4} thin-film electrodes showed charge and discharge efficiency of 80-84% in the first cycle, which was much higher than that for an untreated LiNi{sub 1/2}Mn{sub 3/2}O{sub 4} thin-film electrode (73%). The values of the charge and discharge efficiency were still higher than that for an untreated electrode after the 30th cycle. The charge and discharge curves gave two plateaus at around 4.72 and 4.76 V, which were very similar to those for the untreated electrode. Ac impedance spectroscopy revealed that the surface film resistance should not increase by Zr(OBu){sub 4}/PMMA treatment. XPS measurements suggest that a composite layer should be ...

2008-10-15

444

PbZrO sub 3 -doped (Ba,Sr)TiO sub 3 -based dielectrics for high-voltage capacitor applications  

Energy Technology Data Exchange (ETDEWEB)

This paper reports that high-dielectric ceramics with the composition (94.7% {minus} x) (Ba,Sr)TiO{sub 3} + PbZrO{sub 3} + 5Bi{sub 2}Ti{sub 3}O{sub 9} + 0.3MnO{sub 2}, where the ration (Ba)/(Sr) = 1.25 and x {le} 15 mol%, have been developed for high-voltage capacitors. The dielectric constant of the ceramics is in the range 1200 to 1900 at room temperature, and the room-temperature dielectric loss, tan{delta}, is less than 0.3%, except when 15 mol% PbZrO{sub 3} is added with sintering at 1180{degrees}C to 1240{degrees}C for 2 h. Ceramics with more than 8 mol% zirconate show the Y5S characteristic of capacitance, and those with less than 8 mol% additive exhibit the Z5S characteristic. The dielectric constant gradually increases with increment in the ac signal voltage at 60 Hz, but decreases beyond a threshold value that varies with zirconate content and sintering conditions. The variation of the dielectric constant at 2 kVrms/mm (with respect ...

1991-11-01

445

Isoscalar giant dipole resonance in {sup 90}Zr, {sup 116}Sn, {sup 144}Sm and {sup 208}Pb excited by 240 MeV {alpha} particle scattering  

Energy Technology Data Exchange (ETDEWEB)

The giant resonance regions of {sup 90}Zr, {sup 116}Sn, {sup 144}Sm and {sup 208}Pb were investigated using 240 MeV {alpha} particle scattering at small angles including 0 deg. E1 strengths corresponding to 91{+-}11%, 89{+-}10%, 105{+-}12% and 95{+-}13% of the isoscalar E1 energy-weighted sum rule were identified between 18{<=}E{sub x}{<=}31 MeV, 16{<=}E{sub x}{<=}30 MeV, 15{<=}E{sub x}{<=}27 MeV and 15{<=}E{sub x}{<=}25 MeV with centroid energies of 24.8{+-}0.4 MeV, 22.5{+-}0.3 MeV, 21.6{+-}0.3 MeV and 19.3{+-}0.3 MeV and rms widths of 3.2{+-}0.2 MeV, 3.5{+-}0.2 MeV, 3.2{+-}0.2 MeV and 2.5{+-}0.2 MeV for {sup 90}Zr, {sup 116}Sn, {sup 144}Sm and {sup 208}Pb, respectively. Parameters obtained for the isoscalar giant monopole resonance, isoscalar giant quadrupole resonance and high energy octupole resonance are in agreement with accepted values.

1999-03-29

446

Isoscalar giant dipole resonance in "9"0Zr, "1"1"6Sn, "1"4"4Sm and "2"0"8Pb excited by 240 MeV #alpha# particle scattering  

International Nuclear Information System (INIS)

The giant resonance regions of "9"0Zr, "1"1"6Sn, "1"4"4Sm and "2"0"8Pb were investigated using 240 MeV #alpha# particle scattering at small angles including 0 deg. E1 strengths corresponding to 91#+-#11%, 89#+-#10%, 105#+-#12% and 95#+-#13% of the isoscalar E1 energy-weighted sum rule were identified between 18#<=#E_x#<=#31 MeV, 16#<=#E_x#<=#30 MeV, 15#<=#E_x#<=#27 MeV and 15#<=#E_x#<=#25 MeV with centroid energies of 24.8#+-#0.4 MeV, 22.5#+-#0.3 MeV, 21.6#+-#0.3 MeV and 19.3#+-#0.3 MeV and rms widths of 3.2#+-#0.2 MeV, 3.5#+-#0.2 MeV, 3.2#+-#0.2 MeV and 2.5#+-#0.2 MeV for "9"0Zr, "1"1"6Sn, "1"4"4Sm and "2"0"8Pb, respectively. Parameters obtained for the isoscalar giant monopole resonance, isoscalar giant quadrupole resonance and high energy octupole resonance are in agreement with accepted values.

1999-03-29

447

Fabrication of zircon for disposition of weapons plutonium  

International Nuclear Information System (INIS)

This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). In an effort to address the problems of long term storage and nuclear waste minimization, zircon has been proposed as a host medium for plutonium and other actinides recovered from dismantled nuclear weapons. The objective of this work is to investigate the feasibility of large scale fabrication of Pu-bearing zircon. Since PuO_2 is thermodynamically less stable than ZrO_2, it is expected that the process parameters determined for synthesizing ZrSiO_4 (zircon) would be applicable to those for PuSiO_4 (Pu-zircon). Furthermore, since the foremost concern in plutonium processing is the potential for contamination release, this work emphasizes the development of process parameters, using zircon first, to anticipate potential material problems in the containment system for reaction mixtures during ...

448

Effective thickness of CeO{sub 2} buffer layer for YBCO coated conductor by advanced TFA-MOD process  

Energy Technology Data Exchange (ETDEWEB)

YBCO films were fabricated on PLD-CeO{sub 2}/IBAD-Gd{sub 2}Zr{sub 2}O{sub 7}/Hastelloy substrates using the advanced TFA-MOD process. The effective thickness of the CeO{sub 2} buffer layer for obtaining high I{sub c} was investigated in short samples of YBCO films. The CeO{sub 2} buffer layer was epitaxially grown on an IBAD-Gd{sub 2}Zr{sub 2}O{sub 7} template tape with 18 deg. of {delta}{phi} by a reel-to-reel PLD system. The in-plane grain alignment of PLD-CeO{sub 2} buffer layers rapidly improved with the thickness and saturated at a critical thickness of 0.8 {mu}m. The size of CeO{sub 2} grains was about 1 {mu}m at the saturated thickness of {delta}{phi}. YBCO films with the thickness of 1 {mu}m were deposited by the TFA-MOD on the CeO{sub 2} buffer layer with different thickness films. Improvement of the CeO{sub 2} in-plane grain alignment resulted in increase of I{sub c}. The I{sub c} values of 250-290 A were obtained with the CeO{sub 2} ...

2007-10-01

449

Charged particle spectra: 140 MeV #alpha# particle bombardment of "2"7Al, "5"8Ni, "9"0Zr, "2"0"9Bi, and "2"3"2Th  

International Nuclear Information System (INIS)

Complete energy spectra and angular distributions of the light charged particles (A < or = 4) were measured for the bombardment of "2"7Al, "5"8Ni, "9"0Zr, "2"0"9Bi, and "2"3"2Th with 140 MeV #alpha# particles. The spectral shapes of a given emitted particle are very similar for all target nuclei except in the region of the evaporation peak. The slopes of the energy spectra in the forward direction become steeper as the mass of the observed particle decreases and vary very rapidly with angles. The experimental data can be characterized by compound nuclear evaporation processes at low energies, or at backward angles, and by direct reactions, nonequilibrium components and projectile breakup processes at high energies and forward angles. The breakup cross section for #alpha# particles is found to be appreciable. The total yield of light charged particles is approximately a factor approx. 2 to 3 larger than the total reaction cross section for "2"7Al, "5"8Ni, and ...

450

Beta-delayed proton emission: a new series of precursors, and the measurement of 10"-"1"6 s nuclear lifetimes  

International Nuclear Information System (INIS)

The results of investigation into a new series of Z-even nuclei - precursors of delayed protons (PDP) -"6"5Ge, "8"9Se, "9"3Kr, "8"1Zr, and "8"5Mo are presented. PDP were obtained by irradiation of targets in the following reactions: Zn(He, 2n) "6"5Ge, 22 MeV; "4"0Ca("3"2S, 2 pn) "1"9Se, 100 MeV; "6"0Ni ("1"60, 3 n), "7"3Kr, 75 MeV; "5"2Cr ("3"2S, 3n)"8"1Zr, 110 MeV; "5"6Fe("3"2S, 3n)"8"5Mo, 120 MeV. The targets (self-sustaining foils of thickness approximately 1.2 mg/cm"2) were placed at an angle of 15 deg to the direction of the ion beam. Upon irradiation targets were moved downwards into a measuring position. The spectra of protons, X and gamma-rays, and also the spectra of p - x, p-#gamma#, x - #gamma# coincidences accompanying the decay of "6"5Ge, "6"9Se,"7"3Kr and "8"1Zr, and "8"5Mo were measured. The measured half-lives are equal, to 31.5+-1.9, 27.3+-0.5, 28.5+-1.1, 6.3+-0.5, and 5.6 +-0.9 s respectively. The ...

451

True aneurysm originating from the costocervical trunk: surgical excision for recurrence after successful proximal coil embolization.  

Science.gov (United States)

A rare, true aneurysm of a branch of the right subclavian artery is described. Transcatheter coil embolization of the feeder artery was successful in obliterating blood flow into the aneurysm and the mass reduced in size. However, the aneurysm reenlarged over the next week of follow-up due to development and enlargement of the collateral vascular network. Extirpation of the aneurysm was performed. Histopathological examination revealed a true aneurysm. PMID:11833847

2002-01-01

452

The Werner syndrome helicase protein is required for cell proliferation, immortalization, and tumorigenesis in Scaffold Attachment Factor B1 deficient mice  

UK PubMed Central (United Kingdom)

Werner syndrome (WS) is a rare disorder characterized by the premature onset of several pathologies associated with aging. The gene responsible for WS codes for a RecQ-type DNA helicase and is believed...Full Text Available

453

Port Pirie rare earths plant stage 3  

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 ...

454

Optical spectroscopy of uranium monochalcogenides and monopnictides  

International Nuclear Information System (INIS)

The optical properties of uranium monochalcogenides and monopnictides are discussed in terms of their electronic structure. A comparison is made with corresponding rare earth compounds. It is shown that there are close similarities to mixed valence CeN. the results support the occurrence of a dip in the density of d states near Esub(F), where the f density of states has its maximum. Empirical energy level schemes are derived which are found to agree with the existing information from XPS measurements and recent theories. (orig.).

1980-12-01

455

On the effect of misch metal addition on corrosion behaviour of aluminium in inorganic and organic acids  

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.).

1992-10-01

456

Nuclear power plants and the ''dying forests''  

International Nuclear Information System (INIS)

Possible causes of forest damage are discussed. Mapping of affected areas by various workers resulted in dissimilar pictures. Release of radioactive rare gases, aerosols, tritium and carbon-14 seems unlikely to have a significant influence on forest damage. Influence of radioactive fallout, ozone formation by high-voltage transmission lines and synergistic effects is also found to be negligible.

1985-01-01

457

Nonsyndromic bilateral and unilateral optic nerve aplasia: first familial occurrence and potential implication of CYP26A1 and CYP26C1 genes  

UK PubMed Central (United Kingdom)

PurposeOptic nerve aplasia (ONA, OMIM 165550) is a very rare unilateral or bilateral condition that leads to blindness in the affected eye, and is usually associated with other ocular...Full Text Available

458

Neglected simultaneous bilateral femoral neck fractures secondary to narcotic drug abuse treated by bilateral one-staged hemiarthroplasty: a case report  

UK PubMed Central (United Kingdom)

Simultaneous bilateral femoral neck fractures are extremely rare and associated with various conditions. Up to now Most cases had correlations with major trauma, repetitive minor trauma, seizure, parathyroid...Full Text Available

459

MR findings of primary Ewing's sarcoma of greater wing of sphenoid  

International Nuclear Information System (INIS)

Primary Ewing's sarcoma of the skull is a very rare entity. We report MRI findings in a case of Ewing's sarcoma of the greater wing of sphenoid in a 4-year-old patient. Magnetic resonance imaging showed markedly heterogenous signal intensity with areas of haemorrhage and necrosis. It also demonstrated the exact extent of tumour due to its multiplanar capabilities and was, therefore, helpful in planning surgery. Copyright (2002) Blackwell Science Pty Ltd

2002-12-01

460

Liver involvement of multiple myeloma mimicking intrahepatic cholangiocarcinoma: a case report  

International Nuclear Information System (INIS)

Nodular hepatic involvement of multiple myeloma is very rare. We report here on a case of nodular hepatic involvement of multiple myeloma that mimicked intrahepatic cholangiocarcinoma. In patients with multiple myeloma, hepatic involvement of the multiple myeloma might be included in the differential diagnosis of hepatic mass.

2006-09-01

461

Isolated dextrogastria: report of two cases  

International Nuclear Information System (INIS)

Isolated situs inversus of the stomach with otherwise normal position of the thoracic and abdominal viscera is an extremely rare anomaly occurring in two distinct forms. Because of its close relationship to the liver, the right-sided stomach may produce interesting and confusing changes in the liver scan. Two cases illustrate the radiologic features of the two principal types of isolated congenital dextrogastria and the effect of one type on the liver scan.

462

Imaging findings of central nervous system neuroepithelial cysts  

Energy Technology Data Exchange (ETDEWEB)

Neuroepithelial cysts are rare and mostly asymptomatic cerebrospinal fluid (CSF)-like cysts. We describe herein the imaging findings in five patients with neuroepithelial cysts. Two cases of proven and three of presumed neuroepithelial cysts are presented. Three of five are located in the thalamus, a location which is not characteristic for neuroepithelial cysts. In the case of incidental finding of asymptomatic neuroepithelial cyst, clinical and radiological follow-up is indicated and surgical intervention is not necessarily warranted. (orig.) With 5 figs., 6 refs.

1998-05-01

463

High critical current superconducting tapes  

Energy Technology Data Exchange (ETDEWEB)

Improvements in critical current capacity for superconducting film structures are disclosed and include the use of a superconducting RE-BCO layer including a mixture of rare earth metals, e.g., yttrium and europium, where the ratio of yttrium to europium in the RE-BCO layer ranges from about 3 to 1 to from about 1.5 to 1.

2003-09-23

464

Extraction-spectrophotometric determination of terbium in its mixture with lanthanum  

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 ...

1975-01-01

465

Extensive peritoneal calcifications associated with continuous ambulatory peritoneal dialysis  

Energy Technology Data Exchange (ETDEWEB)

Peritoneal calcification, which can lead to intestinal obstruction and potentially lethal hemoperitoneum, is a rare complication of continuous ambulatory peritoneal dialysis. We describe a case in which extensive peritoneal calcification had arisen for this reason. Although the patient was asymptomatic, extensive calcification was present on the parietal and visceral peritoneum, including the hepatic and splenic surface. (author)

2000-07-01

466

Double-electron-capture cross section for I/sup +/ in a magnesium-vapor target  

Energy Technology Data Exchange (ETDEWEB)

Measurements of the double-electron-capture process in which a positive ion of iodine becomes a negative ion in a single collision with a magnesium atom are reported between 20 and 90 keV. The cross section is comparable to that for the rare gases and not as large as might be expected from a two-valence-electron atom. This process is probably insignificant in the production of negative ion beams using a magnesium-vapor target.

1987-06-15

467

Disruption of the ATP-binding Cassette B7 (ABTM-1/ABCB7) Induces Oxidative Stress and Premature Cell Death in Caenorhabditis elegans*  

UK PubMed Central (United Kingdom)

X-linked sideroblastic anemia with ataxia (XLSA/A) is a rare inherited disorder characterized by mild anemia and ataxia. XLSA/A is caused by mutations in the ABCB7 gene, which encodes...Full Text Available

2011-06-17

468

Design, development and testing of A31M wood composite stall regulated blade for serial production  

Energy Technology Data Exchange (ETDEWEB)

Despite the long track record of the technology, wood composite has rarely been applied to blades of this scale or for tip braked stall-regulated rotors. This paper describes how the design has been taken successfully from the concept to design through structural testing, certification and operational testing of the prototype set. (orig.)

1999-07-01

469

Cytology of a giant adult-type rhabdomyoma of the tongue  

British Library Electronic Table of Contents (United Kingdom)

Abstract Adult rhabdomyoma is a rare primary benign tumour of striated muscle origin that almost exclusively presents in the head and neck region with predilection for male. We herein report a case of an adult rhabdomyoma in a 67-year-old male with cytologic features. The lesions was located in the tongue extended to the left parapharyngeal region. We discuss the cytological findings with a brief review of the literature on this entity. Diagn. Cytopathol. 2010. 2010 Wiley-Liss, Inc.

2011-01-01

470

Chorea-ballism associated with nonketotic hyperglycaemia or diabetic ketoacidosis: Characteristics of 25 patients in Korea  

British Library Electronic Table of Contents (United Kingdom)

Chorea-ballism is a rare form of movement disorder complicated by severe hyperglycaemia and in association with a contralateral basal ganglia lesion. We analysed the clinical characteristics of 25 Korean patients with chorea-ballism associated with nonketotic hyperglycaemia or diabetic ketoacidosis. Possible mechanisms of disease are also discussed.

2011-01-01

471

Chemical detection of leukocytes in urine by means of a new multiple test strip.  

Science.gov (United States)

The performance of the leukocyte test area of the new multiple urine test strip, Multistix-10-SG, was evaluated in both field trials and model experiments. The detection limit was found to be adequate for routine purposes. Unspecific reactions are rare and generally indicated by the results of the other test areas. PMID:3572312

1987-02-01

472

Cerebral sparganosis. Case report.  

Science.gov (United States)

The tapeworm Spirometra mansonoides infects man worldwide, particularly in Asian countries. Rarely, the central nervous system is involved; such a case is presented here. In the total of 12 reported cases, including the case described, the worm presented clinically as a mass suspicious for neoplasm or chronic abscess cavity. Surgical removal was invariably curative in each case. Although infrequent, the possibility of tapeworm infection should be entertained in the evaluation of intracranial masses in patients who have visited exotic locales. PMID:2191089

1990-07-01

473

CT imaging of a primary malignant mixed mullerian tumor arising from the peritoneum  

British Library Electronic Table of Contents (United Kingdom)

Primary peritoneal malignant mixed mullerian tumors are very rare. We report the case of a patient presenting with pain in the right upper quadrant of the abdomen and in whom the physical examination demonstrated a peritoneal mass. Computed tomography (CT) confirmed the presence of a mass, with invasion of adjacent organs.

2008-01-01

474

Assessing predictive skill of models to optimise crop management and design  

Environmental Research Database

DescriptionAn ability to foresee impacts on output is invaluable to any industry; good prediction is the basis of good management. Many research models can predict crop performance, but the skill (used here to include accuracy, precision, facility and credibility) of these predictions is rarely assessed, so is not well known. The only research model successfully adopted for practical purposes in the UK is the Broom's Barn Beet Model. Thus we propose here, research to assess and publish the skill of the [continued...

2004-01-30

475

Acute myelomonocytic leukemia after irradiation and chemotherapy for Ewing's sarcoma  

International Nuclear Information System (INIS)

A case is presented in which the diagnosis of acute myelomonocytic leukemia was made 16 months after the start of irradation and chemotherapy for Ewing's sarcoma. The association of these two diseases is rare. The etiologic role of therapy in the development of leukemia is speculative in this case. However, there is need for surveillance for secondary neoplasms of all types so that the benefits of therapy may be properly weighed against the risks.

476

A nuclear engine design with {sup 242m}Am as a nuclear fuel  

Energy Technology Data Exchange (ETDEWEB)

A preliminary design for a nuclear engine is presented. The engine is based on the nuclear heating of a gas composed of H{sub 2} and {sup 242m}Am as a nuclear fuel. This engine has an initial volume of 0.135 m{sup 3} and at 64 MPa the critical mass is 0.228 kg. The simplicity {sup 242m}Am of the engine design might compensate for the use of rare nuclear fuel, such as {sup 242m}Am.

2000-01-01

477

Predicted versus observed cosmic-ray-produced noble gases in lunar samples: improved Kr production ratios. [From excitation functions for proton spallation of Rb, Sr, Y, Zr at 10 MeV to 10 GeV  

Science.gov (United States)

New sets of cross sections for the production of krypton isotopes from targets of Rb, Sr, Y, and Zr were constructed primarily on the bases of experimental excitation functions for Kr production from Y. These cross sections were used to calculate galactic-cosmic-ray and solar-proton production rates for Kr isotopes in the moon. Spallation Kr data obtained from ilmenite separates of rocks 10017 and 10047 are reported. Production rates and isotopic ratios for cosmogenic Kr observed in ten well-documented lunar samples and in ilmenite separates and bulk samples from several lunar rocks with long but unknown irradiation histories were compared with predicted rates and ratios. The agreements were generally quite good. Erosion of rock surfaces affected rates or ratios for only near-surface samples, where solar-proton production is important. There were considerable spreads in predicted-to-observed production rates of /sup 83/Kr, due at least in part to uncertainties in ...

1979-01-01

478

A practical {sup 99m}Tc generator using (n, {gamma}) {sup 99}Mo  

Energy Technology Data Exchange (ETDEWEB)

For a new and practical {sup 99m}Tc generator using not (n, f){sup 99}Mo, but (n, {gamma}){sup 99}Mo, an inorganic polymer adsorbent framed with oxygen-zirconium-chlorine bonds with a high adsorption performance of Mo has been developed; the polymer adsorbent was named PZC. The amounts of {sup 99}Mo (Mo) adsorbed are stably more than 250 mg/g(PZC). But, the current experiments with 0.5 MBq to 1.85 GBq of {sup 99}Mo gave a subject that the breakthrough of {sup 99}Mo in the elution of {sup 99m}Tc from the adsorbent was 0.05-0.5 %, although the breakthrough of Zr was less than the detection limit of 5 x 10{sup -2} mg(Zr) to 1 g of PZC, and {sup 99m}Tc was eluted constantly with 78{+-}4%. To apply the adsorbent as a generator commercially in Japan, the {sup 99}Mo breakthroughed from the generator must be suppressed to less than 0.15 kBp({sup 99}Mo)/MBq({sup 99m}Tc) by law which is equivalent to 0.015 %, and the {sup 99}Mo breakthrough is controlled ...

2000-10-01

479

Thermodynamic prediction of distribution coefficients for the solvent extraction of the rare earth metals  

International Nuclear Information System (INIS)

A thermodynamic model for predicting the distribution coefficients has been developed by taking into account the extraction mechanism and the chloride complexation when Sm, Eu, Gd, Tb, Dy and Ho for single component systems are extracted from acidic chloride solutions by di-2-ethylhexyl ester in kerosene, respectively. The model equation includes two constants, of which one corresponds to the apparent extraction equilibrium constant and the other is due to the variation of the activity coefficients of organic species. These values are determined from a few experimental data by the curve fitting method. Then, the distribution coefficients under untried calculations, Bromley's formulation is used to estimate the activity coefficients of aqueous species and the interaction parameters for some rare earth chlorides are reported in terms of morality and molarity using data from Spedding et al. According to the authors the validity of this method has been confirmed by ...

480

Reappraisal of solid selective emitters  

Energy Technology Data Exchange (ETDEWEB)

New rare earth oxide emitters show greater efficiency than previous emitters. As a result, based on a simple model the efficiency of these emitters was calculated. Results indicate that the emission band of the selective emitter must be at relatively low energy (less than or equal to .52 eV) to obtain maximum efficiency at moderate emitter temperatures (less than or equal to 1500 K). Thus low bandgap energy PV materials are required to obtain an efficient thermophotovoltaic (TPV) system. Of the 4 specific rare earths (Nd, Ho, Er, Yb) studied Ho has the largest efficiency at moderate temperatures (72 percent at 1500 K). A comparison was made between a selective emitter TPV system and a TPV system that uses a thermal emitter plus a band pass filter to make the thermal emitter behave like a selective emitter. Results of the comparison indicate that only for very optimistic filter and thermal emitter properties will the filter TPV system have a ...

1990-05-01

481

Rare-earth-rich tellurides: Gd_4NiTe_2 and Er_5M_2Te_2 (M=Co, Ni)  

International Nuclear Information System (INIS)

Three new rare earth metal-rich compounds, Gd_4NiTe_2, and Er_5M_2Te_2 (M=Ni, Co), were synthesized in direct reactions using R, R_3M, and R_2Te_3 (R=Gd, Er; M=Co, Ni) and single-crystal structures were determined. Gd_4NiTe_2 is orthorhombic and crystallizes in space group Pnma with four formula units per cell. Lattice parameters at 110(2)K are a=15.548(9), b=4.113(2), c=11.7521(15)A. Er_5Ni_2Te_2 and Er_5Co_2Te_2 are isostructural and crystallize in the orthorhombic space group Cmcm with two formula units per cell. Lattice parameters at 110(2)K are a=3.934(1), b=14.811(4), c=14.709(4)A, and a=3.898(1), b=14.920(3), c=14.889(3)A, respectively. Metal-metal bonding correlations were analyzed using the empirical Pauling bond order concept.

2004-11-01

482

Radiative performance of rare earth garnet thin film selective emitters  

Energy Technology Data Exchange (ETDEWEB)

In this paper the authors present the first emitter efficiency results for the thin film 40 percent Er-1.5 percent Ho YAG (Yttrium Aluminum Garnet, Y3Al5O12) and 25 percent Ho YAG selective emitter at 1500 K with a platinum substrate. Spectral emittance and emissive power measurements were made (1.2 less than lambda less than 3.2 microns). Emitter efficiency and power density are significantly improved with the addition of multiple rare earth dopants. Predicted efficiency results are presented for an optimized (equal power density in the Er, (4)I[sub 15/2]-(4)I[sub 13/2] at 1.5 microns, and Ho, (5)I[sub 7]-(5)I[sub 8] at 2.0 micron emission bands) Er-Ho YAG thin film selective emitter.

1994-08-01

483

Production of rare earth enriched isotopes and americium 242 using metallphthalocyanines  

International Nuclear Information System (INIS)

A technique of producing radioactive isotopes of rare earth elements (r.e.e.) and carrier free "2"4"2Am is suggested. The technique makes use of ''sandwich'' phthalocya=- nine complexes of r.e.e. and americium placed on sorbent. This is a new type of r.e.e. compounds and actinides (C_3_2H_1_6N_8)_2M (M is a metal ion) which are thermally, radiationally and chemically stable, dissolve well in some organic solvents and do not dissolve in water. Radiation and chemically stable activated carbon is used as a sorbent carrier. After irradiation the target is treated by a weakly acid solution or complex-former solution. Radioactive atoms formed due to (n, #gamma#)-reaction and desoleting the complex because of recoil transfer into the solution. When irradiating in the flux of 10"1"3 neutr./cm"2 x s for 1 hour it is possible to produce radioactive isotopes with the yield from 20 to 90%, for example "1"6"0Tb, "1"6"6Ho with enrichment factor > 100 and "2"4"2Am with ...

484

Pollen flora of Pakistan--LXVII: acanthaceae  

International Nuclear Information System (INIS)

Pollen morphology of 30 species of the family Acanthaceae belonging to 11 genera has been investigated using light and scanning electron microscope. Acanthaceae is a eurypalynous family. Pollen are usually radially symmetrical, isopolar, sub-prolate to prolate rarely prolate-spheroidal or sub-oblate to oblate-spheroidal, generally tricolporate or heterocolporate rarely colpate or porate. Exine ornamentation varies from medium to coarse reticulate, or often lopho-reticulate with luminae perforated to baculate or scabrate. On the basis of apertural type, exine ornamentation and colpal membrane eight distinct pollen types have been recognized viz., Pollen type-I: Barleria cristata-type, Pollen type-II: Blepharis ciliaris-type, Pollen type-III: Hygrophila polysperma - type, Pollen type-IV: Justicia adhatoda-type, Pollen type-V:Lepidagathis incurva-type, Pollen type- VI: Peristrophe paniculata-type, Pollen type-VII: Ruellia patula-type and Pollen ...

2010-12-01

485

Photoluminescence properties and local electronic structures of rare earth-activated Sr3AlO4F  

British Library Electronic Table of Contents (United Kingdom)

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 Sr3AlO4F. Sr3AlO4F:Ce^3^+ shows an unusual long-wa...

2010-01-01

486

Paramagnetic susceptibility of nonstoichiometric fluorides with the fluorite-type structure  

Energy Technology Data Exchange (ETDEWEB)

Magnetic properties of single crystals of nonstoichiometric fluorides M[sub 1-x]R[sub x]F[sub 2+x] (M = Ca, Sr, Ba; R = Ce, Pr, Nd, Gd, Ho, Er, Tm, Yb; with 0.05 [le] x [le] 0.28) with the fluorite-type structure have been studied for the first time. The magnetic susceptibility was measured using a Faraday balance in the 15-300 K temperature range. The samples are paramagnetic following the Curie-Weiss law. The values of paramagnetic Curie temperatures and effective magnetic moments of rare-earth ions have been found. Deviations of the temperature dependence of magnetic susceptibility from the Curie-Weiss law are observed for some nonstoichiometric fluorides at temperatures ranging from 60 to 85 K. Possible reaons for these deviations are discussed. Measurements of magnetic susceptibility provide an effective technique for a rapid and accurate determination of the concentration of rare-earth ions in nonstoichiometric fluorides.

1993-01-01

487

Oxide acid-base reaction relating to the inhibition of vandium attack on REY zeolite catalysts. [Rare earth-exchanged yttrium  

Science.gov (United States)

Certain materials, especially Sn, passivate the rare earth-exchanged Y zeolite (REY) used in petrochemical fluid-cracking catalysts against vanadium degradation caused by V impurities in the feed oil. The mechanism of passivation was investigated here from the standpoint of high-temperature oxide acid-base reaction; i.e., where the controlling factors were considered to be Lewis acid-base reactions between V{sub 2}O{sub 5}, the RE oxides, SnO{sub 2}, etc. Molten salt tests at 680{degree}C showed SnO{sub 2}, presumably because of its acidic nature, to be essentially nonreactive with V{sub 2}O{sub 5} or Na{sub 2}O-V{sub 2}O{sub 5} compounds. A hypothesis was developed to explain how the passivation effect by Sn might result from the unique resistivity of SnO{sub 2} to reaction with V{sub 2}O{sub 5}.

1991-05-01

488

Oxidative dehydrogenation of ethane on rare-earth oxide-based catalysts  

Energy Technology Data Exchange (ETDEWEB)

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 conditions (T{sub ...

1998-12-31

489

Origin and spread of a common deletion causing mucolipidosis type II: insights from patterns of haplotypic diversity  

British Library Electronic Table of Contents (United Kingdom)

Coutinho MF, Encarnao M, Gomes R, da Silva Santos L, Martins S, Sirois-Gagnon D, Bargal R, Filocamo M, Raas-Rothschild A, Tappino B, Laprise C, Cury GK, Schwartz IV, Artigals O, Prata MJ, Alves S. Origin and spread of a common deletion causing mucolipidosis type II: insights from patterns of haplotypic diversity. Mucolipidosis II (ML II alpha/beta), or I-cell disease, is a rare genetic disease in which activity of the uridine diphosphate (UDP)-N-acetylglucosamine:lysosomal enzyme N-acetylglucosamine-1-phosphotransferase (GlcNAc-phosphotransferase) is absent. GlcNAc-phosphotransferase is a multimeric enzyme encoded by two genes, GNPTAB and GNPTG. A spectrum of mutations in GNPTAB has been recently reported to cause ML II alpha/beta. Most of these mutations were found to be private or rare. ...

2011-01-01

490

Magnetic moment measurements of gadolinium, holmium and ytterbium tartrate trihydrate crystals  

British Library Electronic Table of Contents (United Kingdom)

Magnetic moment and susceptibility of single crystals of rare earth tartrates of the type R(C4H4O6)(C4H5O6)3H2O (where R = Gd, Ho, and Yb), using a vibration sample magnetometer are reported. The experimental values of molar susceptibilities for Gd(C4H4O6)(C4H5O6)3H2O, Ho(C4H4O6)(C4H5O6)3H2O, and Yb(C4H4O6)(C4H5O6)3H2O are 2.58x10-2, 4.66x10-2, and 8.03x10-3 (in cgs em units), respectively. The calculated effective magnetic moments are in good agreement with the theoretical predictions on rare earth ions.

2008-01-01

491

In situ ellipsometric studies of formation kinetics of rare earth metal conversion coatings on magnesium alloy  

International Nuclear Information System (INIS)

In situ spectroscopic ellipsometry was employed to investigate the initial regime of rare earth metal (REM) conversion coatings formation on AZ31 magnesium alloy. Three REM salts solutions, 0.05 mol.dm"-"3 Ce(NO_3)_3, La(NO)_3 and Sm(NO)_3 solutions, were used for REM conversion coatings preparation. By deconvoluting the ellipsometric data, the surface of the fresh well-polished AZ31 magnesium alloy was found to be covered with 15.80 nm thick native (hydr)oxide film; the refractive indices and the thickness of Ce, La and Sm conversion coatings were obtained. The formation kinetics of three REM coatings follows different exponential functions and the coatings exhibit different optical properties. La conversion coating has the largest n values and the lowest k values while Sm conversion coating is just opposite. Moreover, the pH variation of the bulk conversion solutions upon the coatings formation was recorded. It is confirmed that the reduction of protons leads to ...

2008-05-01

492

High temperature susceptibilities of actinide monopnictides and monochalcogenides  

International Nuclear Information System (INIS)

The inverse susceptibilities of the monopnictides and monochalcogenides of the light rare earths plotted vs. temperature flatten off at high temperatures. This behaviour is well explained by van Vleck paramagnetism of the excited states of the multiplet. For almost all actinide pnictides and chalcogenides a similar flattening-off is observed. Since spin orbit coupling is much stronger than in the light rare earth compounds an analogous interpretation is not possible. Susceptibility curves for uranium compounds can be fitted by adding a temperature dependent enhanced Pauli paramagnetism to the Curie-Weiss term (modified Curie-Weiss law). The high temperature susceptibility behaviour of neptunium compounds is very similar to uranium compounds i.e. an appreciable deviation from the Curie-Weiss law is only visible for the chalcogenides. The plutonium chalcogenides show a temperature independent paramagnetism, which can be explained either by a ...

1998-06-12

493

High efficiency direct thermal to electric energy conversion from radioisotope decay using selective emitters and spectrally tuned solar cells  

International Nuclear Information System (INIS)

Thermophotovoltaic (TPV) systems are attractive possibilities for direct thermal-to-electric energy conversion, but have typically required the use of black body radiators operating at high temperatures. Recent advances in both the understanding and performance of solid rare-earth oxide selective emitters make possible the use of TPV at temperatures as low as 1200K. Both selective emitter and filter system TPV systems are feasible. However, requirements on the filter system are severe in order to attain high efficiency. A thin-film of a rare-earth oxide is one method for producing an efficient, rugged selective emitter. An efficiency of 0.14 and power density of 9.2 W/KG at 1200K is calculated for a hypothetical thin-film neodymia (Nd2O3) selective emitter TPV system that uses radioisotope decay as the thermal energy source.

1993-08-23

494

Herlyn-Werner-Wunderlich syndrome: uterus didelphys, blind hemivagina and ipsilateral renal agenesis. Sonographic and MR findings in 11 cases  

Energy Technology Data Exchange (ETDEWEB)

Uterus didelphys with obstructed hemivagina and ipsilateral renal agenesis is a rare entity, sometimes referred to as Herlyn-Werner-Wunderlich syndrome (HWW). It usually presents after menarche with progressive pelvic pain, sometimes with regular menses, and a palpable mass due to hemihaematocolpos. The diagnosis is generally made only if the suspicion of this genitourinary syndrome is raised. To highlight the imaging diagnostic clues in this rare condition. We report on 11 adolescents with this condition. Sonography mostly allowed the correct diagnosis by showing uterovaginal duplication, haematocolpos or haematometrocolpos, and the absence of the ipsilateral kidney. MRI provided more detailed information regarding uterine morphology, the continuity with each vaginal channel (obstructed and nonobstructed), and the bloody nature of the contents. Early and accurate diagnosis of this syndrome is important so that adequate and prompt surgical ...

2007-07-15

495

Effect of microalloying and thermomechanical processing on the structure and mechanical properties of constructional steel  

Energy Technology Data Exchange (ETDEWEB)

The effect of microalloying with carbide-forming (V,Ti,Nb) and rare-earth elements and of high-temperature thermomechanical processing (HTMP) on the structure, mechanical properties and low temperature behaviour of 38CrSi steel has been investigated. It has been shown that in the case of dissolution of carbides during heating for quench hardening, the tempering resistance of the steel increases. It has also been found that - as a result of HTMP - the susceptibility of the steel irreversible temper brittleness decreases, irrespective of the steel having been microalloyed or not. The data, originating from tensile testing and impact testing (with the help of laser interferometry) in the temperature range from +20 to -196 degC, has been explained in terms of fractographic analysis. It has been shown that microalloying and HTMP favour the occurrence of ductile microvoids in the fracture. On the other hand, HTMP and rare-earth elements changes the ...

1998-10-01

496

Effect of Ho"3"+ substitutions on the structural and magnetic properties of BaFe_1_2O_1_9 hexaferrites  

International Nuclear Information System (INIS)

Holmium doped barium based hexaferrites BaFe_1_2_-_2_xHo_2_xO_1_9 with (x = 0.0-1.0) were synthesized by solid state reaction method. Structural and magnetic characterization of these ferrites provide significant information about their reactive physical properties. X-ray analysis reveals that in all samples M-type structure exist with few secondary phases. Scanning electron microscope revealed the grain size of the specimen. The results show that grain size decreases with the substitution degree of Holmium. Thus rare earth element Holmium Ho"3"+ acts as a grain growth inhibitor. The magnetic hysteresis loops show the variation in the values of magnetic parameters like saturation magnetization (M_s), remanent magnetization (M_r) and coercivity (H_c) were observed by changing Ho"3"+ content in BaFe_1_2_-_2_xHo_2_xO_1_9 ferrites. Coercivity showed a maximum value of 2230 Oe for (x = 0.4) and then decreasing trend were observed in the values of H_c, M_r and M_s with ...

2010-04-09

497

Development of pyrometallurgical partitioning of transuranium elements from high-level liquid waste. Improvement to pyrometallurgical partitioning process and process demonstration  

Energy Technology Data Exchange (ETDEWEB)

The partitioning of transuranium elements (TRUs) from high-level liquid waste (HLLW) through the use of pyrometallurgical technology has been underway since 1986, for the purpose of the improving the safety and public acceptance of the disposal of high-level vitrified waste. Prior to the pyrometallurgical partitioning process, the alkali metals can be separated at the denitration process for oxide conversion of HLLW, chlorination in a chloride salt bath can be used to effectively convert oxides to chlorides, and evaporated chlorides can be captured with high efficiency in another adopted chloride salt bath. The higher separation factors between actinides and rare earths are obtained in a LiCl-KCl/Bi system than in a LiCl-KCl/Cd system. Based on the results, we propose a practical process flow for partitioning TRUs from HLLW by pyrometallurgical technology. This process was demonstrated successfully using simulated purex waste. Each element of the TRUs was separated ...

1998-10-01

498

Specific features of radiation damage in titanium alpha-alloys  

International Nuclear Information System (INIS)

Titanium base 'alpha'-alloys (Pt-7M, RK-20 and Ti-5Al-2Zr-1.5V) are considered for their behaviour under neutron irradiation. The role of alloying elements in radiation hardening is discussed depending of neutron fluence and irradiation temperature. For PK-20 alloy three stages of change in mechanical properties are revealed which are following: incubation period and weak hardening, intense radiation hardening, radiation hardening attenuation. Irradiation temperature rise results in an increase of incubation period and threshold neutron fluence. A special attention is paid to hydrogen absorption in #alpha#-titanium alloys under irradiation. It is concluded that titanium base 'alpha'-alloys are serviceable as structural materials in nuclear plants with allowance made for peculiar features of their radiation behaviour. 4 refs.; 7 figs.; 1 tab.

499

Electrical properties of antimony doped PLZT ceramics prepared by mixed-oxide route  

International Nuclear Information System (INIS)

Ferroelectric [Pb_0_._9_2(La_1_-_zSb _z)_0_._0_8][Zr_0_._6_0Ti_0_._4_0]O_3 for z = 0.0, 0.3, 0.6, 0.9 and 1 were prepared from their constituent oxides by a solid state reaction technique. The powders were calcined in the temperature range of 1000 deg. C for 6 h. Phase formation, crystal structure and lattice parameter were investigated by X-ray diffraction (XRD) technique. The compacts were sintered at 1250 deg. C for 2 h and their dielectric, ferroelectric and conductive properties were measured. The ferroelectric behavior of the doped samples was studied from their hysteresis loop.

2006-12-21

500

Comparison of sodium zirconium phosphate and Synroc matrices for immobilization of high-level waste  

Energy Technology Data Exchange (ETDEWEB)

The aims of the present work were to investigate possible compatibility between sodium zirconium phosphate (NZP) and Synroc titanate phases, to prepare NZP-based waste forms by hot-pressing rather than sintering, and to investigate the incorporation in NZP of (a) Cs/Sr as simulated heat-generating nuclides; (b) simulated actinides; and (c) simulated Purex waste. The NZP samples were prepared by methods similar to those used for Synroc. The precursor NZP phase was formed from tetrabutyl zirconate Zr(OC{sub 4}H{sub 9}){sub 4}, sodium nitrate, and 85% orthophosphoric acid. Simulated waste nitrate solutions were then mixed with the liquid precursor. After stir drying of the precursor, calcination was carried out at 700{degree}C to remove nitrates and organics.

1996-12-31