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

Not Available

2011-12-01

2

Decay studies of rare-earth isotopes produced in the proton-induced fission

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

3

Physical and optical properties of rare earth cobalt magnets

No abstract prepared

1998-01-01

4

Recovery of rare earths from red mud

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

5

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

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

6

A small particle selective emitter for thermophotovoltaic energy conversion

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

7

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

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

8

Energy transfer processes in rare-earth compounds

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

9

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

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

10

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

11

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

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

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

12

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

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 ...

2009-02-28

13

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

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 ...

2009-02-28

14

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 ...

2011-01-01

15

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

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

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 ...

2011-02-01

16

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

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

17

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

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

18

Obtaining radionuclides of rare earth elements "153Sm, "166Ho and "177Lu in the nuclear reactor WWR-SM

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

19

Extraction of rare earths by carbonic acids melts

English 2008 p. 132-133 Turkey Nishonov, Sh. Khujaev, S.

2008-10-14

20

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

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

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

21

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

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

1972-05-01

22

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

23

Magnetic properties of heavy rare-earth tungstates

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

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

24

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

25

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

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

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

26

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

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

27

Radioanalytical methods of rare earth element determination

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

28

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

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 ...

1989-06-01

29

Magnetic excitations studied with time-of-flight spectroscopy

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 ...

1994-06-01

30

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

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

31

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

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 ...

2009-06-01

32

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

33

Spectroscopic study of rare earth chromates: relation to the structure

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

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

34

Occurrence of magnetism in superconductors

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

35

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

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

36

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

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 ...

37

Spectroscopic study of rare earth chromates: relation to the structure

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

38

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

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

39

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

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

40

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

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

41

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

Determination of rare earths in eluates after chromatographic separation

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

42

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

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

43

Port Pirie rare earths plant stage 3

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 ...

1992-01-01

44

Optical spectroscopy of uranium monochalcogenides and monopnictides

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 ...

45

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

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

46

High critical current superconducting tapes

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

47

Extraction-spectrophotometric determination of terbium in its mixture with lanthanum

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

48

Crystal field in RNiAl compounds studied by inelastic neutron scattering

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

49

Crystal field in RNiAl compounds studied by inelastic neutron scattering

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

50

Iron catalyzed hydrogenation of high sulphur content coals

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

51

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

Four high-sulphur low-rank coals have been treated at hydrogenation conditions with three iron-based catalyst precursors: Red Mud (Fe[sub 2]O[sub 3]), iron sulphide and iron pentacarbonyl. The obtained yields show a dependence with the sulphur content of the coals; the organic sulphur content correlates with the conversion and THF-solubles when Red Mud and iron sulphide are added. In spite of the high hydrogen sulphide partial pressure in the reaction, the addition of other sources of sulphur enhances the percentages in conversion products. 15 refs., 2 figs., 3 tabs.

1993-12-01

52

Reappraisal of solid selective emitters

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 ...

53

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

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 ...

1990-05-01

54

Radiative performance of rare earth garnet thin film selective emitters

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

55

Production of rare earth enriched isotopes and americium 242 using metallphthalocyanines

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

56

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

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 ...

57

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

58

Paramagnetic susceptibility of nonstoichiometric fluorides with the fluorite-type structure

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

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

59

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

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

60

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

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

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61

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

62

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

High temperature susceptibilities of actinide monopnictides and monochalcogenides

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 ...

2008-05-01

63

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

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 ...

1998-06-12

64

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

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

65

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

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

66

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

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 ...

2010-04-09

67

Chemical and sulphur isotope compositions of pyrite in the Jaduguda U (?Cu?Fe) deposit, Singhbhum shear zone, eastern India: Implications for sulphide mineralization

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 ...

1998-10-01

68

British Library Electronic Table of Contents (United Kingdom)

The Jaduguda U (?Cu?Fe) deposit in the Singhbhum shear zone has been the most productive uranium deposit in India. Pyrite occurs as disseminated grains or in sulphide stringers and veins in the ore zone. Veins, both concordant and discordant to the pervasive foliation, are mineralogically either simple comprising pyrite ? chalcopyrite or complex comprising pyrite + chalcopyrite + pentlandite + millerite. Nickel-sulphide minerals, though fairly common in concordant veins, are very rare in the discordant veins. Pyrite in Ni-sulphide association is commonly replaced by pentlandite at the grain boundary or along micro-cracks. Based on concentrations of Co and Ni, pyrite is classified as: type-A ? high Co (up to 30800?ppm), no/low Ni; type-B ? moderate Co (up to 16500?ppm) and moderate to high ...

2011-01-01

69

Thulium-doped vanadate crystals: Growth, spectroscopy and laser performance

British Library Electronic Table of Contents (United Kingdom)

This work is concentrated on growth, spectroscopy and laser performance of thulium-doped vanadate crystals. At the beginning the growth techniques are analyzed and then the matrix of vanadates crystal, its structure and physicochemical properties are explained together with the rare earth activators influence. Detailed spectroscopy of the thulium-doped vanadate crystals then follows. On the background of this theoretical analysis and state of the art of the subject the description of thulium vanadate lasers (especially Tm:YVO"4, Tm:GdVO"4, and Tm:LuVO"4) together with their generated output radiation characteristics are presented.

2011-01-01

70

The identification of the 1/2"+[660] proton orbitals at high spins in rare-earth nuclei

The effect of temperature on the radiative performance of Ho-YAG thin film selective emitters

Decay sequences based on the 1/2"+[660] proton orbital have been identified in "1"7"1Ta and "1"7"7Re based on spin, parity, and large alignment. This decay sequence is observed higher in energy than predicted in cranking calculations based on modified oscillator potentials. Similarly known 1/2"-[541] decay sequences in these and other neighbouring isotopes are observed lower in energy than predicted. A reduction in the strength of the spin-orbit potential for protons is suggested as a solution to these problem. (orig.).

71

SiAlON hardmetal materials

The authors present the emitter efficiency results for the thin film 25 percent Ho YAG (Yttrium Aluminum Garnet, Y3Al5O12) selective emitter from 1000 to 1700 K with a platinum substrate. Spectral emittance and emissive power measurements were made (1.2 less than lambda less than 3.2 microns) and used to calculate the radiative efficiency. The radiative efficiency and power density of rare earth doped selective emitters are strongly dependent on temperature and experimental results indicate an optimum temperature (1650 K for Ho YAG) for thermophotovoltaic (TPV) applications.

1995-01-01

72

On the validity of the pseudo-spin concept for axially symmetric deformed nuclei

Sialons are phases in the Si-Al-O-N and M-Si-Al-O-N systems where M includes Li, Mg, Ca, Sc, Y and the rare earth elements. They are comparable in variety with the mineral silicates and are built up of one-, two-, and three-dimensional arrangements of (Si,Al)(O,N)/sub 4/ tetrahedra in the same way that the structural units of the silicates are SiO/sub 4/ tetrahedra. These new materials include N-containing ceramics, glasses and glass-ceramics that are being explored for their thermal, chemical and physical properties.

73

On the magnetic behaviour of REBa_2F_7 compounds (RE=Eu, Dy, Ho, Er, Tm and Yb)

The average single-particle field shows a very small pseudo-spin-orbit splitting in the pseudo-spin representation. If this splitting is neglected, pseudo-spin becomes a good quantum number and the resulting scheme (the pseudo-Nilsson model) has a very simple interpretation. The pseudo-spin symmetry embodied in the realistic deformed average field is explored by comparing the single-particle energies and wave functions of the deformed Woods-Saxon model with the corresponding results of the pseudo-Nilsson model. The scheme is used to calculate the magnetic moments of deformed odd-A nuclei of the rare-earth region. (orig.).

74

Identification of the 1/2/sup +/(660) proton orbitals at high spins in rare-earth nuclei

The DC magnetic susceptibility of the REBa_2F_7 compounds was measured by a SQUID magnetometer in the temperature range 5-300 K. Except for Eu, the other compounds show either Curie law or Curie-Weiss law with relatively small values of paramagnetic Curie temperature, #theta#_p, with effective magnetic moments in the range expected of electronic ground state of the trivalent rare earth ion with appropriate J value. The behaviour of Eu is complex. (orig.).

75

Hybridisation and crystal field in YbPd sub 2 Si sub 2

Decay sequences based on the 1/2/sup +/(660) proton orbital have been identified in /sup 171/Ta and /sup 177/Re based on spin, parity, and large alignment. This decay sequence is observed higher in energy than predicted in cranking calculations based on modified oscillator potentials. Similarly known 1/2/sup -/(541) decay sequences in these and other neighbouring isotopes are observed lower in energy than predicted. A reduction in the strength of the spin-orbit potential for protons is suggested as a solution to these problem.

1983-12-08

76

Emittance theory for thin film selective emitter

Experimental data in the hybridised compound YbPd{sub 2}Si{sub 2} is compared with the results obtained with a recently proposed hybridisation model, based on the ''large-degeneracy expansion'' approximation, which takes into account the crystal field splittings of the rare earth ion energy levels. With a unique set of parameters, satisfactory agreement is simultaneously obtained for the thermal variation of the electronic specific heat, of the magnetic susceptibility and of the electric field gradient at the Yb site, as well as for the field variation of the low temperature magnetisation. (orig.).

1991-02-01

77

Effect of yttrium on mechanical properties of 9Cr-2WVTa low active martensite steel

Thin films of high temperature garnet materials such as yttrium aluminum garnet (YAG) doped with rare earths are currently being investigated as selective emitters. This paper presents a radiative transfer analysis of the thin film emitter. From this analysis the emitter efficiency and power density are calculated. Results based on measured extinction coefficients for erbium-YAG and holmium-YAG are presented. These results indicated that emitter efficiencies of 50 percent and power densities of several watts/sq cm are attainable at moderate temperatures (less than 1750 K).

1994-08-01

78

Effect of temperature gradient on thick film selective emitter emittance

The effect of the rare earth element, yttrium, on the mechanical properties of 9Cr-2WVTa low active martensite steel for fusion reactor was studied and the metallurgical behavior of yttrium in the steel was primarily analyzed. The results show that it is easy for yttrium to aggregate and form the blocky yttrium rich inclusions in the steel, which can dissever the continuity of the matrix and produce micro-cracks for fracture. The yttrium rich inclusions were distributed along the rolling direction, which made the fracture surface delaminated in the tensile and impact samples, and reduced the mechanical properties of the steel. (authors)

2009-03-01

79

ESR study of X-ray irradiated rare earth (Ln) ion-doped glaserite and Ln ion-doped langbeinite

A temperature gradient across a thick ({ge}.1mm) film selective emitter will produce a significant reduction in the spectral emittance from the no temperature gradient case. Thick film selective emitters of rare earth doped host materials such as yttrium-aluminum-garnet (YAG) are examples where temperature gradient effects are important. In this paper a model is developed for the spectral emittance assuming a linear temperature gradient across the film. Results of the model indicate that temperature gradients will result in reductions the order of 20{percent} or more in the spectral emittance. {copyright} {ital 1997 American Institute of Physics.}

1997-03-01

80

[Magnetic thin film research]: Progress report year 2

X-ray irradiation-induced paramagnetic radicals in rare earth (Ln) ion-doped glaserite and Ln ion-doped langbeinite were studied by means of ESR technique, aiming at developing the highly sensitive sensor for an ESR dosimetry. The samples were prepared by two kinds of procedures as follows. In one process, the glaserite (K{sub 3}Na(SO{sub 4}){sub 2}) matrix or the langbeinite (K{sub 2}Mg{sub 2}(SO{sub 4}){sub 3}) matrix were synthesized by heating the mixture of K{sub 2}SO{sub 4} and Na{sub 2}SO{sub 4} or the mixture of K{sub 2}SO{sub 4} and MgSO{sub 4} at 1023 K for 1 hour in He flow. The matrices obtained were mixed well with a fixed amount of Ln{sub 2}(SO{sub 4}){sub 3} (Ln=La, Eu, Gd, Lu) powder and heated at 1023 K for 1 hour in He flow. In the other process, the homogeneous mixture of a fixed amount of K{sub 2}SO{sub 4}, Na{sub 2}SO{sub 4} and Ln{sub 2}(SO{sub 4}){sub 3} powders or a fixed amount of K{sub 2}SO{sub 4}, MgSO{sub 4} and ...

1992-06-01

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81

Crystalline electric field of the rare-earth nickelates RniO{sub 3} (R = Pr, ND, Sm, Eu, and Pr{sub 1-x}La{sub x},0 {le} X {le} 0.7) determined by inelastic neutron scattering.

The work in the past year has primarily involved four areas of magnetic thin films: amorphous rare earth-transition metal alloys, epitaxial CoPt{sub 3} and Ni-Pt alloy thin films, amorphous rare earth doped Si (a new class of dilute magnetic semiconductor with large negative magnetoresistance which the authors have discovered), and exchange-coupled antiferromagnetic insulators. In the amorphous alloys, they made a systematic study of the effects of local anisotropy, macroscopic (perpendicular) anisotropy, and exchange constant on the fundamental (and practical) properties of these magnetic alloys, as originally described in the grant proposal. The work on the epitaxial Co-Pt (and more recently Ni-Pt) alloys was originally undertaken as a comparison study to the amorphous alloys. Crystalline Co-Pt alloys have many striking similarities to the amorphous rare ...

1996-09-01

82

Crystalline electric field of the rare-earth nickelates RNiO{sub 3} (R=Pr, Nd, Sm, Eu, and Pr{sub 1-x}La{sub x}, 0{<=}x{<=}0.7) determined by inelastic neutron scattering

The rare-earth based nickelates RNiO{sub 3} (R = Pr, Nd, Sm, Eu, and Pr{sub 1-x}La{sub x}, 0{<=}x{<=}0.7) were studied by inelastic neutron scattering. Energy splittings due to the crystalline-electric-field (CEF) interaction at the R{sup 3+} site within the electronic ground-state J multiplet (for R = Pr, Nd, and Pr{sub 1-x}La{sub x}) as well as within the two lowest-lying J multiplets (for R = Sm and Eu) were directly observed, and the corresponding CEF energy-level schemes were reconstructed. The latter were rationalized in terms of CEF parameters, which vary smoothly over the rare-earth series and give magnetic properties associated with the R sublattice in agreement with results from neutron powder diffraction experiments. Across the metal-insulator transition, a continuous change in the electronic part of the CEF parameters is observed. However, an attempt to quantify a charge transfer from the observed variation of the CEF ...

1999-12-01

83

Crystalline electric field of the rare-earth nickelates RNiO_3 (R=Pr, Nd, Sm, Eu, and Pr_1_-_xLa_x, 0#<=#x#<=#0.7) determined by inelastic neutron scattering

The rare-earth based nickelates RNiO{sub 3} (R=Pr, Nd, Sm, Eu, and Pr{sub 1-x}La{sub x}, 0{<=}x{<=}0.7) were studied by inelastic neutron scattering. Energy splittings due to the crystalline-electric-field (CEF) interaction at the R{sup 3+} site within the electronic ground-state J multiplet (for R=Pr, Nd, and Pr{sub 1-x}La{sub x}) as well as within the two lowest-lying J multiplets (for R=Sm and Eu) were directly observed, and the corresponding CEF energy-level schemes were reconstructed. The latter were rationalized in terms of CEF parameters, which vary smoothly over the rare-earth series and give magnetic properties associated with the R sublattice in agreement with results from neutron powder diffraction experiments. Across the metal-insulator transition, a continuous change in the electronic part of the CEF parameters is observed. However, an attempt to quantify a charge transfer from the observed variation of the CEF ...

1999-12-01

84

Characteristics of oxidation reaction of rare-earth chlorides for precipitation in LiCl-KCl molten salt by oxygen sparging

The rare-earth based nickelates RNiO_3 (R=Pr, Nd, Sm, Eu, and Pr_1_-_xLa_x, 0#<=#x#<=#0.7) were studied by inelastic neutron scattering. Energy splittings due to the crystalline-electric-field (CEF) interaction at the R"3"+ site within the electronic ground-state J multiplet (for R=Pr, Nd, and Pr_1_-_xLa_x) as well as within the two lowest-lying J multiplets (for R=Sm and Eu) were directly observed, and the corresponding CEF energy-level schemes were reconstructed. The latter were rationalized in terms of CEF parameters, which vary smoothly over the rare-earth series and give magnetic properties associated with the R sublattice in agreement with results from neutron powder diffraction experiments. Across the metal-insulator transition, a continuous change in the electronic part of the CEF parameters is observed. However, an attempt to quantify a charge transfer from the observed variation of the CEF parameters in an effective point charge ...

1999-12-01

85

Zinc electrode and rechargeable zinc-air battery

The precipitation reaction of some rare earth chlorides (La/Ce/Nd/GdCl3) in a LiCl-KCl molten salt has been carried out by using the oxygen sparging method. In this study, regardless of the oxygen sparging time and the molten salt temperature, oxychlorides (REOCl) for LaCl3, NdCl3 and GdCl3, and an oxide (REO2) for CeCl3 are formed as a precipitate. The conversion of rare-earth chlorides into insoluble precipitates was described by using a conversion ratio. The conversion ratio increased exponentially with the oxygen sparging time and finally showed asymptotic value at 1,023K of the molten salt temperature condition. The conversion ratios of LaCl3, NdCl3 and GdCl3 were increased with the molten salt temperature, however, even though the conversion ratio was increased from 0.660 to 0.995 with increasing molten salt temperature from 823 to 923 K at 60 min of a sparging time, the values of the conversion ratio of CeCl3 were ...

2006-10-01

86

Effect of Zinc-Enriched Yeast Supplementation on Serum Zinc and Testosterone Concentrations in Ethanol Feeding Rats

This patent describes an improved zinc electrode for a rechargeable zinc-air battery comprising an outer frame and a porous foam electrode support within the frame which is treated prior to the deposition of zinc thereon to inhibit the formation of zinc dendrites on the external surface thereof. The outer frame is provided with passageways for circulating an alkaline electrolyte through the treated zinc-coated porous foam. A novel rechargeable zinc-air battery system is also disclosed.

1989-06-27

87

Improved zinc electrode and rechargeable zinc-air battery

Full Text Available

2008-07-01

88

The influence of CeO_2 on the corrosion resistance of laser remelted alloy spray coatings on steel

The invention comprises an improved rechargeable zinc-air cell/battery having recirculating alkaline electrolyte and a zinc electrode comprising a porous foam support material which carries the active zinc electrode material. 5 figs.

1988-06-21

89

Rare earth metal rich magnesium compounds RE4NiMg (RE=Y, Pr-Nd, Sm, Gd-Tm, Lu)-Synthesis, structure, and hydrogenation behavior

The main compositions of iron-base amorphous self-fluxing alloy powders of 150 mesh, used in this work, are Fe, Cr, Ni, W, Mo, B, Si and C. The ranges of each element in at% are (65-70)Fe, (3-5)Cr, (2-4)Ni, (2-4)W, (1-2)Mo, (10-14)B, (4-7)Si and (2-3)C. The atomic ratio of metal-metalloid is about 80:20, so this alloy is abbreviated as M_8_0X_2_0. The material on which coatings were deposited is 1020 steel, austenitized for 1h at 880 C, water quenched, and tempered at 180 C for 1h. This heat treatment resulted in a low carbon martensite structure with a hardness of HRC35-45. After cleaning, shot blasting and preheating the steel to about 200 C, the authors sprayed a thin Ni-Al alloy layer of about 0.1--0.15mm in thickness onto the specimen by means of an oxygen-acetylene torch to provide better bonding of the coating with substrate. Then the M_8_0X_2_0 and M_8_0X_2_0+8%CeO_2 alloy coatings were sprayed to a thickness of about 0.6--0.8mm. The CeO_2 was added as particles of 200 mesh, ...

90

Zinc-air battery technology: Combination of mechanical and electrical recharge

The rare earth metal rich compounds RE4NiMg (RE=Y, Pr-Nd, Sm, Gd-Tm, Lu) were synthesized from the elements in sealed tantalum tubes in an induction furnace. All compounds were investigated by X-ray diffraction on powders and single crystals: Gd4RhIn type, space group F4-bar 3m, Z=16, a=1367.6(2) pm for Y4NiMg, a=1403.7(3) pm for Pr4NiMg, a=1400.7(1) pm for Nd4NiMg, a=1386.5(2) pm for Sm4NiMg, a=1376.1(2) pm for Gd4NiMg, a=1362.1(1) pm for Tb4NiMg, a=1355.1(2) pm for Dy4NiMg, a=1355.2(1) pm for Ho4NiMg, a=1354.3(2) pm for Er4NiMg, a=1342.9(3) pm for Tm4NiMg, and a=1336.7(3) pm for Lu4NiMg. The nickel atoms have trigonal prismatic rare earth coordination. These NiRE6 prisms are condensed via common edges to a three-dimensional network which leaves voids for Mg4 tetrahedra and the RE1 atoms which show only weak coordination to the nickel atoms. The single crystal data indicate two kinds of solid ...

2009-02-01

91

de Haas--van Alphen effect and Fermi surface of lutetium

No abstract prepared.

2000-07-01

92

Valence mixing in rare earth compounds

We report de Haas--van Alphen measurements of the Fermi surface of lutetium at temperatures down to 0.3 K and in fields up to 150 kG in the (1010) and (1120) planes. Lutetium, having a filled 4f shell, serves as a nonmagnetic prototype of the structurally similar (hcp), trivalent, heavy rare-earth elements from Gd to Tm. The fact that no complete frequency branches were observed indicates that there are no closed pieces of the Fermi surface. We observed all but one orbit predicted by relativistic augmented-plane-wave calculations of Keeton and Loucks and by recent spin-orbit--linearized-augmented-plane-wave calculations of Tibbetts and Harmon. The data support a geometry similar to that of yttrium, and in good qualitative agreement with energy-band theory.

93

Surface analysis by Fourier-transform infrared (FTIR) spectroscopy

The concepts of ''fast'' and ''slow'' time scale valence measurements are emphasized by a comparison of L/sub III/ absorption and Mossbauer effect measurements on the temperature induced valence change in EuPd/sub 2/Si/sub 2/. Further the authors show how synchrotron radiation based L/sub III/ measurements of the Ce-valence state can be used to demonstrate electronic structure trends under wide changes in chemical environment. The purpose of this paper is to provide an introduction to researchers in the People's Republic of China to the field of mixed valent rate earth compounds. They hope to illustrate some of the basic concepts in this field, how the field is contributing to the overall insight into the chemical physics of solids and finally how synchrotron radiation measurements in particular are playing a key role in this field.

94

Superconductivity on the threshold of magnetism in CePd{sub 2}Si{sub 2} and CeIn{sub 3}

A diffuse-reflectance capability for the Fourier transform infrared spectrometer at the Y-12 Plant Laboratory has been implemented. A sample cell with a 25 to 400/sup 0/C temperature-controlled sample stage and an ultrahigh-vacuum-to-atmospheric pressure gas-handling capability has been developed. Absorbance of light from the spectrometer beam, resulting from the beam being scattered from a powder sample, can be measured. This capability of detecting molecular species on and in powders is to be used to study chemisorption on actinide and rare-earth metals, alloys, and compounds. Cell design is described along with experiments demonstrating its performance in detecting moisture absorption on uranium oxide, moisture and carbon dioxide absorption on the lithium hydride/hydroxide system, and carbon dioxide absorption on potassium borohydride. 13 figures.

1981-08-12

95

Superconductivity on the threshold of magnetism in CePd_2Si_2 and CeIn_3

The magnetic ordering temperature of some rare-earth-based heavy-fermion compounds is strongly pressure dependent and can be completely suppressed at a critical pressure, p{sub c}, making way for novel correlated electron states close to this quantum critical point. We have studied the clean heavy-fermion antiferromagnets CePd{sub 2}Si{sub 2} and CeIn{sub 3} in a series of resistivity measurements at high pressures up to 3.2 GPa and down to temperatures in the mK region. In both materials, superconductivity appears in a small window of a few tenths of a GPa on either side of p{sub c}. We present detailed measurements of the superconducting and magnetic temperature-pressure phase diagram, which indicate that superconductivity in these materials is enhanced, rather than suppressed, by the closeness to magnetic order. (author)

2001-03-26

96

Superconductivity in the ternary rare-earth (Y, La, and Lu) compounds RPd_2Si_2 and RRh_2Si_2

The magnetic ordering temperature of some rare-earth-based heavy-fermion compounds is strongly pressure dependent and can be completely suppressed at a critical pressure, p_c, making way for novel correlated electron states close to this quantum critical point. We have studied the clean heavy-fermion antiferromagnets CePd_2Si_2 and CeIn_3 in a series of resistivity measurements at high pressures up to 3.2 GPa and down to temperatures in the mK region. In both materials, superconductivity appears in a small window of a few tenths of a GPa on either side of p_c. We present detailed measurements of the superconducting and magnetic temperature-pressure phase diagram, which indicate that superconductivity in these materials is enhanced, rather than suppressed, by the closeness to magnetic order. (author)

2001-03-26

97

Spectroscopic properties of Pr"3"+ doped LaWO_4Cl and La_3WO_6Cl_3

We have investigated the superconducting and metallurgical properties of the ternary compounds RPd_2Si_2 and RRh_2Si_2 with R = Y, La, and Lu. All RPd_2Si_2 compounds and LaRh_2Si_2 were found to be type-I superconductors below 1 K. A detailed metallurgical analysis shows that segregation of second phases can easily mask the intrinsic (stoichiometric ratio 1:2:2) intermetallic-compound properties. Two sample-preparation techniques, viz., single crystals and off-stoichiometry, were utilized to establish where bulk superconductivity occurs. The type-I behavior of these compounds is explained with an analogous model as is used for the heavy-fermion superconductors CeCu_2Si_2 and URu_2Si_2.

98

Spectroscopic properties of Pr sup 3+ doped LaWO sub 4 Cl and La sub 3 WO sub 6 Cl sub 3

The spectroscopic properties of Pr"3"+ doping two lanthanum chlorotungstate hosts: the orthorhombic LaWO4Cl (1-1) and the hexagonal La3WO4Cl6 (3-1), as well as those of PrWO4Cl and Pr3wO613 have been investigated. The simulations of the energy level schemes are carried out within the crystal field theory frame. Each simulation involves 7 free ion parameters and 14 non-zero crystal field parameters (cfps), corresponding to the C_s point symmetry of the site occupied by the rare earth, in both structures.

1992-01-01

99

Possible observation of the coexistence of superconductivity and long-range magnetic order in NdRh_4B_4

The spectroscopic properties of Pr{sup 3+} doping two lanthanum chlorotungstate hosts: the orthorhombic LaWO4Cl (1-1) and the hexagonal La3WO4Cl6 (3-1), as well as those of PrWO4Cl and Pr3wO613 have been investigated. The simulations of the energy level schemes are carried out within the crystal field theory frame. Each simulation involves 7 free ion parameters and 14 non-zero crystal field parameters (cfps), corresponding to the C{sub s} point symmetry of the site occupied by the rare earth, in both structures.

1992-01-01

100

Open-system Behavior during Pluton-Wall-rock Interaction as Constrained from a Study of Endoskarns in the Sierra Nevada Batholith, California

The ternary rare earth compound NdRh_4B_4 has been studied by means of critical field, low temperature heat capacity, and static magnetic susceptibility measurements. Features in the upper critical field and heat capacity data at 1.31 K and 0.89 K suggest the occurrence of long-range magnetic order in the superconducting state. The temperature dependence of the static magnetic susceptibility follows a Curie-Weiss law with an effective magnetic moment #mu#sub(eff) = 3.58 +- 0.05 #mu#sub(B) and a Curie-Weiss temperature thetasub(p) = -6.2 +- 1.0 K between 20 K and room temperature. However, magnetization vs. applied magnetic field isotherms suggest the development of a ferromagnetic component in the Nd"3"+ magnetization at low temperatures. (author).

1979-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

101

British Library Electronic Table of Contents (United Kingdom)

Crustal xenoliths (pyroxenites and plagioclase + quartz + pyroxene lithologies) from the Quaternary Big Pine volcanic field on the eastern flank of the Sierra Nevada Batholith in California (USA) represent the products of metasomatic reaction between the margins of a Cretaceous granodioritic pluton and Paleozoic marbles, possibly at mid-crustal depths based on the equilibration temperatures recorded by Ti-in-quartz geothermometry. This interpretation is based on the presence of plagioclase showing relict plutonic textures, pyroxenite characterized by nearly pure diopside clinopyroxene, recrystallized plagioclase with anomalously high anorthite content, textures indicating replacement of plagioclase by clinopyroxene (and vice versa), `ghost' plagioclase rare earth element signatures in some...

2011-01-01

102

Modelling Of Monazite Ore Break-Down By Alkali Process Spectrometry

Microstructure and mechanical behaviour of an elevated temperature Mg-rare earth based alloy

A computer modelling has been developed for the calculation of mass balance of monazite ore break-down by alkali process at Rare Earth Research and Development Center. The process includes the following units : ore digestion by concentrate NaOH, dissolution of digested ore by HCl, uranium and thorium precipitation and crystallization of Na3PO4 which is by-product from this process. The model named RRDCMBP was prepared in Visual Basic language. The modelling program can be run on personal computer and it is interactive and easy to use. User is able to choose any equipment in each unit process and input data to get output of mass balance results. The model could be helpful in the process analysis for the further process adjustment and development.

2005-10-18

103

Measurements and calculations of M-shell X-ray production in Er, Yb and Lu by 0.75-6 MeV He ions

AM-SC1 is a heat treatable magnesium alloy that has been specifically developed to achieve the elevated temperature strength and creep properties necessary for engine block applications. This paper describes the interrelationship between the microstructure and the mechanical properties of AM-SC1. The compressive and tensile strengths are relatively insensitive to temperature up to and including 450 K and the tensile yield behaviour deviates from a standard Hall-Petch relationship at grain sizes below 200 ?m. The microstructural features contributing to the creep resistance are both inter- and intra-granular in nature and are on length scales from nanometers to micrometers. The creep behaviour at 423 K and 450 K is diffusion controlled, with any contribution from the grain boundaries being negligible.

2009-04-15

104

Materials and processing designs for high-performance magnesium alloys

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

2005-12-15

105

Magnetic properties of some Au_3R compounds

Materials and processing designs for advanced magnesium alloys with fine microstructures and superior properties were established by the combination of the repeated plastic working and the Mg{sub 2}Si synthesis in solid-state. The grain size was less than 1 {mu}m via RPW process due to its severe plastic working on raw powder. The hot extruded magnesium alloys produced in industries showed high ultimate tensile strength, e.g. 420{proportional_to}450 MPa, when employing Mg-Zn-Al-Ca-RE (Rare Earth) alloy coarse powder, having 0.5{proportional_to}2 mm diameter, as input materials. (orig.)

2005-07-01

106

Magnetic properties of RPd_2Si ternary compounds with (R = Gd, Tb, Dy, Ho and Er)

The magnetization of a series of intermetallic compounds Au_3R, where R is Gd through Yb, was investigated at 2.5 to 300"0K in applied fields up to 26 kOe. All the compounds studied exhibited the orthorhombic TiCu_3--Do/sub a/ type structure. For high temperatures, the temperature dependence of the inverse susceptibility followed a Curie--Weiss law, yielding effective paramagnetic moments in good agreement with the values calculated for free tripositive rare earth ions. At low temperatures, deviations from Curie--Weiss behavior were observed in all cases. These deviations are ascribed to the influence of crystal-field and exchange interactions. (auth).

1974-12-03

107

Magnetic properties of RPd/sub 2/Si ternary compounds with (R = Gd, Tb, Dy, Ho and Er)

Magnetic properties of polycrystalline samples of RPd_2Si compounds (R = Gd, Tb, Dy, Ho and Er) are presented. The Gd and Tb based compounds are antiferromagnetic with Neel temperatures of 13.5 and 21 K respectively. For both compounds a metamagnetic transition is observed in low field. Moreover, in TbPd_2Si a transition between two different antiferromagnetic phases is observed at 8.5 K. The Dy, Ho and Er based compounds are ferromagnetic with Curie temperatures of 9, 3.5 ad 2.8 K respectively. The observed properties result from indirect exchange interactions and crystal field effects acting on rare earth ions which lie in a very low symmetry site. (author).

108

Luminescence and x-ray absorption measurements of persistent SrAl2O4:Eu,Dy powders: Evidence for valence state changes

Magnetic properties of polycrystalline samples of RPd/sub 2/Si compounds (R = Gd, Tb, Dy, Ho and Er) are presented. The Gd and Tb based compounds are antiferromagnetic with Neel temperatures of 13.5 and 21 K respectively. For both compounds a metamagnetic transition is observed in low field. Moreover, in TbPd/sub 2/Si a transition between two different antiferromagnetic phases is observed at 8.5 K. The Dy, Ho and Er based compounds are ferromagnetic with Curie temperatures of 9, 3.5 ad 2.8 K respectively. The observed properties result from indirect exchange interactions and crystal field effects acting on rare earth ions which lie in a very low symmetry site.

1984-01-01

109

K S Krishnan and the early experimental evidences for the Jahn-Teller Theorem

The development of new efficient afterglow phosphors is currently hampered by a limited understanding of the persistent luminescence mechanism. Radioluminescence (RL) and x-ray absorption measurements on the persistent phosphor SrAl2O4:Eu,Dy were combined to reveal possible valence state changes for the rare earth (co)dopants. Traps in the phosphor material are quickly filled when exposing thermally emptied SrAl2O4:Eu,Dy powder to x rays. On the same time scale a partial oxidation of Eu2+ to Eu3+ is observed by x-ray absorption near-edge spectroscopy (XANES), while for the trivalent dysprosium the valence state remains unchanged. The impact of these observations on the recently proposed models for persistent luminescence is discussed.

2011-08-01

110

Itinerant magnetism of Gd_xLa_1_-_xMSi (M=Fe, Co) compounds

Jahn-Teller theorem, proposed in 1937, predicts a distortional instability for a molecule that has symmetry based degenerate electronic states. In 1939 Krishnan emphasized the importance of this theorem for the arrangement of water molecules around the transition metal or rare earth ions in aqueous solutions and hydrated saltes, in a short and interesting paper published in Nature by pointing out atleast four existing experimental results in support of the theorem. This paper of Krishnan has remained essentially unknown to the practitioners of Jahn-Teller effect, eventhough it pointed to the best experimental results that were available, in the 30's and 40's, in support of Jahn-Teller theorem. Some of the modern day experiments are also in conformity with some specific suggestions of Krishnan.

1998-01-01

111

Improving the sheared edge in the blanking of commercial AZ31 sheet through texture modification

The magnetic properties of polycrystalline and single crystalline rare earth transition metal silicides Gd_xLa_1_-_xMSi (M =Fe, Co) were investigated. Magnetic measurements have been made in static magnetic fields up to 13 kOe and in pulsed magnetic fields up to 250 kOe in the temperature range from 4.2 to 350 K. The magnetic susceptibility in the paramagnetic state of all the investigated compounds obeys the Curie-Weiss law except for LaFeSi and LaCoSi. Increase of the La content in Gd_xLa_1_-_xFeSi compounds leads to a decrease of the Curie and Neel temperatures, which can be explained by a decrease of positive exchange interactions. (orig.).

1995-09-01

112

British Library Electronic Table of Contents (United Kingdom)

Commercial rolled magnesium sheets of alloys AZ31 (Mg-3 mass%Al-1 mass%Zn) and ZE10 (Mg-1 mass% Zn-<1 mass% Rare Earths) in O-temper condition were used for blanking experiments near room temperature. A serrated fracture surface can be observed in case of AZ31 but not in case of ZE10. During the shearing process of the AZ31 sheet, many micro cracks parallel to the sheet plane are generated in the shearing zone. These micro cracks lead to the formation of loose particles during the shearing operation, which interfere with further processing of the part and incur additional costs by increasing the scrap rate. It is found that the strong basal texture of this alloy is an important reason for the generation of such serrated cracks. In this paper a new method of selective texture modification i...

2011-01-01

113

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

High frequency converters for thermophotovoltaic applications

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

114

Generalised rotationally invariant core (RIC) model: a two mass-point approach

Thermophotovoltaic (TPV) converters were developed and tested at the heat source operating temperature of 1,700 K. Rare-earth-doped yttrium aluminum garnet (YAG) and lutetium yttrium aluminum garnet (Lu, YAG) selective emitters, as well as a blackbody emitter, were coupled to InGaAs/InP photovoltaic (PV) cells and bandpass/infrared (IR) reflector filters. YAG-based selective emitters were adopted with Ho, Tm, and Er. PV cells had bandgaps of 0.51, 0.57, and 0.69 eV. Converter energy conversion efficiencies approaching 30%, as well as electrical output power densities near 2 W/cm{sup 2} were demonstrated. The overall performance of the filtered blackbody-based converter was found to be superior to the selective emitter YAG-based converters. The details of the measurements performed on the above converters and their individual components are presented.

1996-12-31

115

Formation of AlN-polytypoid phases during #alpha#-SiAlON decomposition

A generalised RIC model for the rotational - vibrational spectra of deformed even-even nuclei of ellipsoidal shape in the rare-earth region has been proposed by incorporating many important features of various microscopic models proposed earlier. The two mass-point model and the governor model moments of intertia are obtained on the basis of the proposed model with appropriate limiting values of the radius of the RIC. Also, the model moment of intertia goes to zero for spherical nuclei, thus giving no rotational spectra for such nuclei. A quantum mechanical treatment of the model on the basis of the two mass-point concept, is expected to give results which are in better agreement with experiments. (author).

116

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

Phase transformations from #alpha#- to #beta#-SiAlONs (i.e., from #alpha#' to #beta#') have been recently reported in a number of rare-earth SiAlON systems during postsintering heat treatment. In the present work, this transformation process in a Sm (#alpha# + #beta#)-SiAlON material is studied by using XRD, TEM, and EDS X-ray mapping techniques. It is observed that in addition to the formation of #beta#' and M' phases, the #alpha#'-to-#beta#' transformation is accompanied by a significant increase in the amount of an AlN-polytypoid phase. The results suggest that some #alpha#' phases are thermodynamically unstable at temperatures lower than the material sintering temperature and will decompose when conditions allow. For the composition studied in this work, the #alpha#-SiAlON decomposition can be described in general as #alpha#' #-># #beta#' + M' + AlN polytypoid.

117

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

118

Effects of modification on microstructure and properties of ultrahigh carbon (1.9wt.% C) steel

British Library Electronic Table of Contents (United Kingdom)

The effects of a modifier that contains Rare Earths (RE), low melting point alloy (Al-Bi-Sb) and Ca-Si alloy on an ultrahigh carbon steel containing 1.9wt.% C were studied. Microstructure characterization was carried out with optical microscopy (OM) and scanning electronic microscopy (SEM) combined with energy-dispersive spectrometry (EDS). Upon modification, the continuous eutectic carbide network structure was broken up and changed to a partly isolated and finer blocky structure in the as-cast alloy. Differential scanning calorimetry (DSC) revealed that the eutectoid temperature increased and the eutectic temperature decreased for the modified alloy. Modification also improved the impact toughness of the tempered steel, with a significant increase from 6.5 to 12.6Jcm^-^2, despite the har...

2011-01-01

119

Effects of lanthanum(III) and EDTA on the growth and competition of Microcystis aeruginosa and Scenedesmus quadricauda

British Library Electronic Table of Contents (United Kingdom)

Rare earth elements (REEs) are widely used to increase crop production in China. However, little attention has been paid to their impacts on aquatic ecology. Batch cultivation was used here to study the effects of lanthanum (La) and EDTA on the growth and competition of the cyanobacterium Microcystis aeruginosa and the green alga Scenedesmus quadricauda. When EDTA was present at a very low concentration (0.269mmolL-1), low lanthanum concentrations (7.2mmolL-1) had little stimulative effect on the growth of M. aeruginosa and S. quadricauda, whereas a high lanthanum concentration (72mmolL-1) had significant inhibitory effect on both of them. The results of cultivation experiments suggested that the inhibitory effect on M. aeruginosa was higher than that on S. quadricauda and S. quadricauda c...

2009-01-01

120

Earliest art in the Americas: incised image of a proboscidean on a mineralized extinct animal bone from Vero Beach, Florida

British Library Electronic Table of Contents (United Kingdom)

A fragmented fossil bone incised with the figure of a proboscidean was recently found at Vero Beach, Florida near the location where Late Pleistocene fauna and human bones were recovered from 1913 to 1916. This engraving may represent the oldest and only existing example of Terminal Pleistocene art depicting a proboscidean in the Americas. Because of the uniqueness, rarity, and potential antiquity of this specimen, caution demanded that a variety of tests be used in an attempt to verify its authenticity. The mineralized bone was identified as mammoth, mastodon, or giant sloth. Rare earth element analysis was consistent with the fossil bone being ancient and originating at or near the Old Vero site (8-IR-9). Forensic analysis suggests the markings on the bone are not recent. Optical microsc...

2011-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

121

A comparison of patient doses in lumbar spine radiography from various X-ray units in Poland

Additives to neutralize hydrogen sulphide and their application

A number of diagnostic X-ray units in Poland were subjected to analysis. The air kerma on X-ray tables was measured for the X-ray parameters used routinely during lumbo-sacral spine radiography of standard adult patient. Measurements of air kerma were performed using TLD made of lithium-fluoride. The doses received by patients in different X-ray departments can differ more than two orders of magnitude (from 0.42 mGy up to 72.11 mGy), for the same X-ray examination. The dose can be significantly reduced if fluorescent screens made from components of rare earth are used. (author). 10 refs, 1 fig., 2 tabs.

1995-12-31

122

{beta}-delayed proton decays near the proton drip line

At VNIIKRneft the possibility of using natural ore magnetite as an additive to neutralize hydrogen sulphide in drilling mud is considered. Its activity is sufficiently high and is dependent on the overall iron content and its dispersion. For example, the widely available YuGOK industrial group's magnetite compound, which has an overall content of iron of 66% and specific surface PSH-2 1500 cm/sup 2//g under normal operating conditions, is able to absorb in the first 5 hours 500 l hydrogen sulphide per 1 kg/hour. The activity of the YuGOK compound, which has been ground at the Il'sk weighting material plant to the specific surface of 3000 cm/sup 2//g (PSH-2), is inferior only by 10-15% to the ''sponge''. In addition, structural-mechanical indices of solutions that had been processed with both materials are identical when added in the 10-40% range by volume. At this activation level, to ...

1981-01-01

123

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

We briefly reviewed and summarized the experimental study on {beta}-delayed proton decays published by our group over the last 8 years, namely the experimental observation of {beta}-delayed proton decays of nine new nuclides in the rare-earth region near the proton drip line and five nuclides in the mass 90 region with N{approx}Z by utilizing the p-{gamma} coincidence technique in combination with a He-jet tape transport system. In addition, important technical details of the experiments were provided. The experimental results were compared to the theoretical predictions of some nuclear models, resulting in the following conclusions. (1) The experimental half-lives for {sup 85}Mo, {sup 92}Rh, as well as the predicted 'waiting point' nuclei {sup 89}Ru and {sup 93}Pd were 5-10 times longer than the macroscopic-microscopic model predictions of Moeller et al. [At. Data Nucl. Data Tables 66,131(1997)]. These data considerably influenced the predictions ...

2005-05-01

124

Structural and optical investigations of sodium europium carbonate Na{sub 3}Eu(CO{sub 3}){sub 3}

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 ...

125

Rare-earth mixed oxide thin films as 100% lattice match buffer layers for YBa2Cu3O7-x coated conductors

The crystal structure and the luminescence properties of a new carbonate, Na{sub 3}Eu(CO{sub 3}){sub 3}, are presented. Na{sub 3}Eu(CO{sub 3}){sub 3} is orthorhombic, acentric, Ama2, Z = 4; a = 9.942(2) {angstrom}, b = 11.024(3) {angstrom}, c = 7.147(2) {angstrom}; R = 0.019, R{sub w} = 0.051, 2374 unique reflections. The anionic subnetwork is built up from the stacking of {open_quotes}standing on edge{close_quotes} and {open_quotes}flat lying{close_quotes} carbonate layers into which Na{sup +} and Eu{sup 3+} ions are inserted. The symmetry of the EuO{sub 9} polyhedra is C{sub s}. The Eu{sup 3+} ions are inserted. The symmetry of the EuO{sub 9} polyhedra is C{sub s}. The Eu{sup 3+} luminescence technique confirms the presence of a unique low symmetry site for the rare earth atom. The electrostatic crystal field (cf) effects on the {sup 7}F multiplet are evaluated on the basis of the phenomenological cf theory. The simulation using C{sub 2v} ...

1997-08-01

126

Elemental transfer from Chinese soil via the diet to the whole human body

Buffer layers with 100% lattice match with YBa2Cu3O7 - ? (YBCO) were prepared from mixed rare-earth-oxides applying a simple sol-gel process and dip-coating method. Structural analysis of the sol-gel derived powder by X-ray diffraction revealed that the mixing parameter, which eliminates the lattice mismatch with YBCO, is x = 0.2382, 0.1852, 0.1252, 0.0906, 0.0793 and 0.0395 in (Eu1 - xHox)2O3, (Eu1 - xErx)2O3, (Eu1 - xYbx)2O3, (Gd1 - xHox)2O3, (Gd1 - xYx)2O3 and (Gd1 - xYbx)2O3, respectively. Microstructural investigations were carried out for Gd1.819Ho0.181O3 films epitaxially grown on cube-textured Ni (100) substrates by sol-gel dip-coating process. X-ray diffraction of the buffer showed strong out-of-plane orientation on Ni tape. The (Gd1 - xHox)2O3 (222) pole figure indicated a single cube-on-cube textured structure. The omega and phi scans revealed good out-of-plane and in-plane alne alignments. The full-width at half-maximum values of omega and phi scan of ...

2010-04-02

127

Effect of Ho{sup 3+} substitutions on the structural and magnetic properties of BaFe{sub 12}O{sub 19} hexaferrites

Based on results from recent studies of elemental dietary intake and organ or tissue content for adult Chinese men, quoted nationwide elemental concentrations in Chinese soil and newly published national average consumption of dietary foods, values of both transfer coefficients and discrimination factor (DF) for transfer from soil via the diet to both critical organs and the whole body have been calculated for important elements in radiation protection, including alkaline earths, alkali metals, rare earths and other related elements. These calculations have used both the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) model and the DF method. In the UNSCEAR model, the basic parameters used to describe the transport of radionuclides are the transfer coefficients P_i_j, which describe the relationship of concentrations or other amounts between compartment i and the following compartment j, whereas the DF is the ...

2008-12-01

128

Crystal-field analysis of Eu"3"+ energy levels in the new rare-earth R BiY_1_-_xR_xGeO_5 oxide

Holmium doped barium based hexaferrites BaFe{sub 12-2x}Ho{sub 2x}O{sub 19} 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{sup 3+} acts as a grain growth inhibitor. The magnetic hysteresis loops show the variation in the values of magnetic parameters like saturation magnetization (M{sub s}), remanent magnetization (M{sub r}) and coercivity (H{sub c}) were observed by changing Ho{sup 3+} content in BaFe{sub 12-2x}Ho{sub 2x}O{sub 19} ferrites. Coercivity showed a maximum value of 2230 Oe for (x = 0.4) and then ...

2010-04-09

129

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

Pale colored BiY_1_-_xR_xGeO_5 (R=rare-earth from Pr to Yb) polycrystalline samples exhibit a crystalline phase isostructural with the orthorhombic Pbca (No. 61) structure-type established for BiYGeO_5 and BiYbGeO_5. R occupies a single point site in the host, with the lowest C_1 symmetry. While for Pr and Nd x must be #<=#0.35, for smaller R ions, Sm to Yb, the phase appears for any x content. Detailed crystallographic data for BiErGeO_5 have been determined from the structure refinement of its neutron diffraction profile at room temperature. Optical absorption and photoluminescence measurements at 10 K have been performed for BiEuGeO_5. An initial approach to the parametrization of crystal-field effects on this new host has been provided by results of the semi-empirical Simple Overlap Model, which considers the crystallographic positions of the nearest neighbors around R. Furthermore, the strongly reduced "7F_J_M set of levels of the 4f"6 configuration has ...

2002-07-13

130

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

The experimental study on #beta#-delayed proton decays near the proton drip line published by our group over the last 8 years were reviewed and summarized briefly, including first observation of 9 precursors in the rare-earth region and new measurements of 5 nuclei in the mass-90 region near N-Z line with the aid of the 'p-#gamma#' coincidence in combination with a He-jet tape transport system. Systematically comparing the experimental data with the current nuclear-model predictions, following points were represented. (1) the experimental half-lives for "8"5Mo and "9"2Rh as well as the predicted 'waiting point' nuclei "8"9Ru and "9"3Pd are 5-10 times longer than the macroscopic-microscopic model predictions given by Moeller et al. It considerably influences the prediction of mass abundances of the nuclides produced in rp-process. (2) The current-model predictions are not consistent with the experimental spin-parity assignments of the proton drip-line nuclei ...

2004-12-01

131

Research and development o zinc-air battery for electric vehicle in USA and Europe; EV yo aen kuki denchi (kaigai no jokyo)

We briefly reviewed and summarized the experimental study on #beta#-delayed proton decays published by our group over the last 8 years, namely the experimental observation of #beta#-delayed proton decays of nine new nuclides in the rare-earth region near the proton drip line and five nuclides in the mass 90 region with N#approx#Z by utilizing the p-#gamma# coincidence technique in combination with a He-jet tape transport system. In addition, important technical details of the experiments were provided. The experimental results were compared to the theoretical predictions of some nuclear models, resulting in the following conclusions. (1) The experimental half-lives for "8"5Mo, "9"2Rh, as well as the predicted 'waiting point' nuclei "8"9Ru and "9"3Pd were 5-10 times longer than the macroscopic-microscopic model predictions of Moeller et al. [At. Data Nucl. Data Tables 66,131(1997)]. These data considerably influenced the predictions of the mass abundances of the ...

2005-05-01

132

Galvanic primary cell with an alkaline electrolyte and an air electrode. Galvanisches Primaerelement mit alkalischem Elektrolyten und einer Luftelektrode

This paper describes zinc-air battery for electric vehicle (EV). This battery is composed of air electrode, zinc electrode, and alkali electrolyte. During the discharge, oxygen taken from the air is reduced at the air electrode, and zinc is dissolved at the zinc electrode. The whole reaction is formation of zinc oxide from oxygen and zinc. This is taken out to use as a secondary battery through exchange and regeneration, which is called mechanical charge. For Electric Fuel, discharged products in the zinc electrode from a spent EV are extracted by a vibrating crusher, and are dissolved in KOH to prepare zinc ion electrolyte. Thus, zinc is obtained through the electrolytic refining. Since the regenerated zinc is separated from the electrolytic electrode as a form of dendritic ...

1998-05-05

133

A new concept in an electrically rechargeable zinc-air alkaline battery. [Porous electrodes

According to the invention, a zinc foil is arranged between the negative electrode of a zinc/air battery (round cell) and the expansion space compensating for the reactive increase in volume of the zinc powder. This zinc foil functioning as a stop diaphragm particularly ensures, from the very onset, that the zinc filling has a density and compactness necessary for good electronic conductance.

1986-11-06

134

Rare-earth doped (#alpha#'/#beta#')-sialon ceramics

This paper describes a new idea for zinc-air battery design. The novel idea is a porous zinc electrode surrounded with a supersaturated zincate solution. 3 figs. (JDH)

1987-10-01

135

Optimized Zn-electrode for the rechargeable zinc-air battery

The objectives of this research were to investigate the possibility of controlling the #alpha#'/#beta#' phase ratio and morphology in Sialon ceramics. These objectives have been sought by the control of the starting composition, and by post sintering heat treatment. The main emphasis has been on the production of a series of #alpha#' and (#alpha#'+#beta#') Sialon ceramics with a minimum amount of the glass phase by the pressureless sintering technique and using ytterbium (Yb) as an #alpha#' stabilising element. The Yb additions were made via the oxide or the alumino- silicate presynthesised glass; the latter was found to improve the density. The XRD analysis of the as sintered materials revealed #alpha#' to be the dominant phase with minor contributions from #beta#' sialon and/ or 12H A1N polytype. Additions of SiO_2 or #beta#-Si_3N_4 were made to various materials to assess potential mechanisms for obtaining control over the microstructural development of #alpha#'/#beta#' sialon ...

136

Optimized zinc electrode for the rechargeable zinc-air battery

For the development of a long-lived electrically rechargeable zinc/air battery, the structure and wettability of pasted zinc electrodes were optimized. Pasted zinc electrodes, having the same nominal capacities but containing 1% to 10% cellulose, were prepared and tested under defined charge and discharge conditions in zinc-oxygen cells. The maximum power as well as the cycle life of these cells were measured. After different times of operation, the porosity and the pore size distribution of the pasted zinc electrodes were measured by means of mercury porosimetry. (author) 4 figs., 1 tab., 6 refs.

1996-06-01

137

Aluminum-Zinc (Al-Zn) Dust Analyses for Recycling Purposes

For the development of a long-lived, electrically rechargeable zinc-air battery the structure and wettability of pasted zinc electrodes were optimized. Pasted zinc electrodes containing 1 to 10% cellulose, but having almost the same nominal capacities, were prepared and tested in zinc/oxygen cells. The effect of discharge rate on cell voltage and delivered capacity, as well as the maximum power, were measured. Furthermore, cell charge-discharge behaviour and cycle life were examined. After different times of operation, the porosity and the pore size distribution of the pasted zinc electrodes were measured by means of mercury porosimetry. The life cycle and peak power drain capability of the Zn/oxygen battery could be substantially improved by the addition of 10 wt% cellulose to the pasted zinc electrode. (author)

1998-09-01

138

The use of low sulphide tailings as the moisture retaining layer in engineered cover systems to prevent AMD

... Accession Number : ADA547552. Title : Aluminum-Zinc (Al-Zn) Dust Analyses for Recycling Purposes. Descriptive Note : Technical rept. ...

2011-08-01

139

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

One of the main problems facing the mining sector is the production of acid mine drainage (AMD), which is caused by the oxidation of sulphide minerals in the presence of water. AMD can have a detrimental effect on the environment. One solution is to use soil covering over the materials that cause acid to limit the gas flux by diffusion. A capillary barrier effect is generated by using various layers of different types of soil. In the composite system till and clay normally form the basis of the fine material layer. The use of low sulphide tailings to replace the use of fine grained soil was studied to evaluate its effectiveness. Following both in situ and laboratory experiments spread over an eight-year period, the results indicated that an effective method to limit the oxygen flux and generation of AMD is the use of non-acid generating tailings as the moisture retaining layer. The main concepts that form the basis of the study, analysis and ...

2000-07-01

140

Superconductivity in the ternary rare-earth (Y, La, and Lu) compounds RPd/sub 2/Si/sub 2/ and RRh/sub 2/Si/sub 2/

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

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

141

Structure and magnetic properties of RE_4CoCd and RE_4RhCd (RE = Tb, Dy, Ho)

We have investigated the superconducting and metallurgical properties of the ternary compounds RPd/sub 2/Si/sub 2/ and RRh/sub 2/Si/sub 2/ with R = Y, La, and Lu. All RPd/sub 2/Si/sub 2/ compounds and LaRh/sub 2/Si/sub 2/ were found to be type-I superconductors below 1 K. A detailed metallurgical analysis shows that segregation of second phases can easily mask the intrinsic (stoichiometric ratio 1:2:2) intermetallic-compound properties. Two sample-preparation techniques, viz., single crystals and off-stoichiometry, were utilized to establish where bulk superconductivity occurs. The type-I behavior of these compounds is explained with an analogous model as is used for the heavy-fermion superconductors CeCu/sub 2/Si/sub 2/ and URu/sub 2/Si/sub 2/.

1986-10-01

142

Separation and recovery method for depleted uranium from spent fuel

New rare earth metal rich cadmium compounds RE_4CoCd and RE_4RhCd (RE = Tb, Dy, Ho) were prepared by high-frequency melting of the elements in sealed tantalum tubes. The samples were studied by x-ray powder and single-crystal diffraction. All the compounds crystallize with Gd_4RhIn-type structure, with space group F4-bar3m. The structures are built up from rigid three-dimensional networks of condensed, cobalt (rhodium) centred trigonal RE_6 prisms. The voids left by these networks are filled by Cd_4 cluster units and the coordination number 14 polyhedra of the RE1 atoms. The terbium and dysprosium compounds in both series undergo antiferromagnetic ordering, whereas the holmium compounds exhibit ferromagnetic ordering. The magnetic ordering in these compounds is characterized by broad peaks around the transition temperatures. The results of detailed crystallographic investigations and preliminary magnetic and specific heat studies are presented ...

2007-02-21

143

Separation and recovery method for depleted uranium from spent fuel

Spent oxide fuels are reduced in a molten salt of CaCl[sub 2]-CaF[sub 2] to convert them into metals, then melted in an Fe-U bath disposed in an electrolytic refining vessel and brought into contact with molten Mg, to extract transuranium elements and rare earth elements contained in the Fe-U bath as metals in the molten Mg. Then molten Mg is removed and the residue is brought into contact with KCl-LiCl molten salt and electrolyzed using the Fe-U as an anode. Then, uranium is recovered by deposition on an iron cathode disposed in chloride electrolytes of the electrolytic refining vessel. Uranium and transuranium elements can be thus separated and, for example, depleted uranium for use in blanket fuels can be recovered easily. This can greatly reduce the temporary storage amount of depleted uranium, to eliminate requirement for a large-scaled facility used exclusively for storing uranium and long time management for uranium. (T.M.).

1993-07-30

144

Selective excitation study of Yb{sup 3+} in GdCa{sub 4}O(BO{sub 3}){sub 3} and YCa{sub 4}O(BO{sub 3}){sub 3}

Spent oxide fuels are reduced in a molten salt of CaCl_2-CaF_2 to convert them into metals, then melted in an Fe-U bath disposed in an electrolytic refining vessel and brought into contact with molten Mg, to extract transuranium elements and rare earth elements contained in the Fe-U bath as metals in the molten Mg. Then molten Mg is removed and the residue is brought into contact with KCl-LiCl molten salt and electrolyzed using the Fe-U as an anode. Then, uranium is recovered by deposition on an iron cathode disposed in chloride electrolytes of the electrolytic refining vessel. Uranium and transuranium elements can be thus separated and, for example, depleted uranium for use in blanket fuels can be recovered easily. This can greatly reduce the temporary storage amount of depleted uranium, to eliminate requirement for a large-scaled facility used exclusively for storing uranium and long time management for uranium. (T.M.).

1992-01-14

145

Selective excitation study of Yb"3"+ in GdCa_4O(BO_3)_3 and YCa_4O(BO_3)_3

The Yb{sup 3+}-doped non-linear rare-earth calcium oxoborate crystals GdCa{sub 4}O (BO{sub 3}){sub 3} (GdCOB) and YCa{sub 4}O(BO{sub 3}){sub 3} (YCOB) were investigated by low-temperature absorption and selective excitation spectroscopy. The selective excitation and emission spectra revealed the spectral features of the main Yb{sup 3+} centre and the principal minority one in both crystals. The energy level schemes for these centres in both hosts, as well as structural assignments, were proposed. It was established that the minority centre, which represents about 10% of the total intensity and was assigned to Yb{sup 3+} in a Ca{sup 2+} site, is not a trap but an energy donor for the main centre. Common features of and differences between the vibronic structure of the two centres in GdCOB and YCOB are discussed. The existence of additional features in YCOB:Yb spectra is pointed out. (author)

2002-02-11

146

Photoluminescence of europium doped LiInO2 powder

The Yb"3"+-doped non-linear rare-earth calcium oxoborate crystals GdCa_4O (BO_3)_3 (GdCOB) and YCa_4O(BO_3)_3 (YCOB) were investigated by low-temperature absorption and selective excitation spectroscopy. The selective excitation and emission spectra revealed the spectral features of the main Yb"3"+ centre and the principal minority one in both crystals. The energy level schemes for these centres in both hosts, as well as structural assignments, were proposed. It was established that the minority centre, which represents about 10% of the total intensity and was assigned to Yb"3"+ in a Ca"2"+ site, is not a trap but an energy donor for the main centre. Common features of and differences between the vibronic structure of the two centres in GdCOB and YCOB are discussed. The existence of additional features in YCOB:Yb spectra is pointed out. (author)

2002-02-11

147

British Library Electronic Table of Contents (United Kingdom)

Abstract Lithium-indium oxide is one of the candidate materials as solid-state scintillators for solar neutrinos due to an inverse --decay of 115In to 115Sn. On the other hand, when doped with rare-earth ions such as Eu3+ or Sm3+, it becomes a promising phosphor material. In this report we present a simple solid-state procedure for preparation of LiInO2:Eu3+ powders. X-ray diffraction confirmed prod-uct in tetragonal structural form (space group: I41/amd) and no impurity phases were detected. Then, high resolution photoluminescence emission measurements were performed at room and low temperatures to find 5D0 - 7FJ. Emission kinetics from 5D0 level exhibited pure single exponential behavior with lifetime of about 1.5 ms. Maximum energy splitting of 7F1 manifold is recorded as a function of ...

2011-01-01

148

Phase relationships in neodymia and ytterbia containing SiAlONs

Phase and microstructural evolution of Ca #alpha#-SiAlON containing elongated grains

The Si_3N_4-rich corner of the phase diagrams for neodymia and ytterbia containing sialons has been investigated by a systematic variation of the m and n values for compositions between 0.5 and 2.0 with a step size of 0.5. Samples requiring nitrides of the rare earth elements have not been prepared. Sintering has been performed at 1800 C for one hour in a nitrogen atmosphere of 1 MPa. The sintered samples were characterized by X-ray diffraction analysis to identify the crystalline phases in equilibrium with sialon. #alpha#- and #beta#-sialon, the 21R AlN polytypoid, and N-melilite M' were found in the Nd containing system. Materials with Yb showed the formation of #alpha#- and #beta#-sialon, and the AlN polytypoids 12H and 21R. The m and n values of the #alpha#-sialon phase have been calculated via their lattice parameters that were refined by a least squares routine. The occurrence and composition of the phases were used to outline their ...

149

Oxidative dimerization of methane over lead-magnesium mixed oxide catalysts

Rare earth stabilised #alpha#-SiAlONs are commonly observed with an equiaxed grain morphology. Elongated #alpha#-SiAlON has been observed in some of these systems, however it usually results from special techniques such as pressure sintering. The formation of elongated #alpha#-SiAlON grains during pressureless sintering has been shown to commonly occur in the Ca #alpha#-SiAlON system. Examination of phase and microstructural development in three Ca #alpha#-SiAlON compositions in the temperature range 1400 deg to 1800 deg C showed that phase development and grain growth occurred at different temperatures. It was found that chemical reactions were completed by 1550 deg C, however significant grain growth did not occur at this temperature. Grain growth progressed from 1600 deg C and continued up to 1800 deg C, the maximum temperature investigated. At 1800 deg C, #alpha#-SiAlON was found to be compatible with Aluminium Nitrides and related phases. ...

1998-09-28

150

Magnetic properties of Pr_2PdSi_3 single crystals

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

1987-08-01

151

M X-ray production in Nd, Gd, Ho and Lu by 1-6 MeV lithium ions

Ternary R_2TSi_3 intermetallic compounds (R=Rare Earth, T=Transition Metal) with hexagonal AlB_2-type crystallographic structure are known because of their interesting physical properties. Pr_2PdSi_3 single crystals were grown by a vertical floating zone method. The compound exhibits congruent melting behavior at a liquidus temperature of about 1770 C. Single crystalline samples show a huge anisotropy at low temperatures due to the crystal electric field effect and order antiferromagnetically below the Neel temperature T_N=2.17 K. This value approximately obeys the linear de Gennes scaling for this class of compounds. The [001] orientation was identified as the magnetic easy axis at room temperature. At lower temperature (#approx#20 K) magnetic easy and hard axes interchange with each other. Two additional magnetic phase transitions were observed at temperatures below 1 K.

2010-03-21

152

Luminescence properties of europium and terbium activated yttrium niobium/tantalate phosphors under VUV-UV excitation

M-shell X-rays of the rare-earth elements {sub 60}Nd, {sub 64}Gd, {sub 67}Ho and {sub 71}Lu were measured for lithium ion bombardment in the energy range 1.0-6.0 MeV. The M-shell X-rays with energies of 0.978-1.631 keV were detected with a LINK analytical detector. The efficiency of the detector was determined by using the known atomic-field bremsstrahlung cross-sections from low energy electron beams and K-shell X-ray measurements with light projectiles. The measured cross-sections are compared to the predictions of the first Born approximation and the ECPSSR (energy loss and Coulomb deflection effects, perturbed stationary state approximation with relativistic correction) theories. The best theoretical description of the present data is given by the ECPSSR theory, even though the discrepancy between data and theory is increasing at higher projectile energies.

2004-06-01

153

Low-temperature properties of ternary magnetic rare-earth transition-metal germanides with the Sc sub 5 Co sub 4 Ge sub 10 -type structure

Various compositions of Y(Ta,Nb)O4:Eu3+,Tb3+ with different Nb and activator concentrations have been investigated under UV and VUV excitation. Some compounds with very strong emission under VUV excitation were found. Such phosphors could be proposed as very good emissive materials for Displays and Lightings. The growing interest in luminescence spectroscopy of rare earth ions in the vacuum ultraviolet (VUV) and the visible (VIS) spectral range is due to industrial demands for new applications. YTaO4 and YNbO4 phosphors are a perspective class of efficient materials that are generally used in X-ray intensifying screens. These phosphors exhibit satisfying luminescence whenever excited by UV light, cathode radiation or X ray. However, to our knowledge, no work has been published on the VUV-excited luminescence for Eu3+ and Tb3+ double activated yttrium niobate and yttrium tantalate based phosphors. In this paper, the VUV-UV PL and PLE spectra of ...

154

Low temperature properties of ternary magnetic rare earth transition metal germanides with the Sc/sub 5/Co/sub 4/Ge/sub 10/-type structure

DC resistivity, dc magnetization, and specific heat of eight Sc{sub 5}Co{sub 4}Ge{sub 10}-type crystal-structure compounds R{sub 5}T{sub 4}Ge{sub 10} for R = Dy, Ho, Er, Tm, and T = Rh and Ir are presented. The resistivity, single-crystal magnetization, and specific-heat results show that in all those compounds, the magnetic moments order antiferromagnetically in the c direction at low temperature. However, in the Er and Tm compounds, the magnetizations along x-y hard directions do not show any anomalies above 2.0 K. This suggests that the ordered Er and Tm ions, which have positive quadrupole coefficients, interact with a crystal field that has an electronic potential valley along the c axis. The fitting of the hard axis magnetizations to Curie-Weiss law suggests that the resulting antiferromagnetic-like {theta} reflects the strength of the crystal-field torque on the magnetic moments rather than the strength of antiferromagnetic exchange.

1988-01-01

155

Lifetimes of superdeformed nuclei in the mass region A {approx}150 with the Eurogam multidetector array; Durees de vie de noyaux superdeformes de la region de masse A {approx}150 mesurees avec le multicompteur Eurogam

DC resistivity, dc magnetization, and specific heat of eight Sc/sub 5/Co/sub 4/Ge/sub 10/-type crystal structure compounds R/sub 5/T/sub 4/Ge/sub 10/ for R = Dy, Ho, Er, Tm, and T = Rh and Ir are presented. The resistivity, single crystal magnetization, and specific heat results show that in all those compounds, the magnetic moments order antiferromagnetically in the c direction at low temperature. However, in the Er and Tm compounds, the magnetizations along x-y hard directions do not show any anomalies above 2.0 K. This suggests that the ordered Er and Tm ions, which have positive quadrupole coefficients ..cap alpha../sub j/, interact with a crystal field that has an electronic potential valley along the c axis. The fitting of the hard axis magnetizations to Curie-Weiss law suggests that the resulting antiferromagnetic-like theta reflects the strength of the crystal field torque on the magnetic moments rather than the strength of antiferromagnetic exchange. 123 refs.

1988-07-01

156

Heat resistant nickel base alloy excellent in workability and high temperature strength properties

This work concerns the study of the nuclear superdeformation phenomenon in the rare earth region (A {approx} 150). The superdeformed (SD) states in Gadolinium and Dysprosium isotopes were produced via heavy-ion induced reactions and studied with the (EUROGAM EUROpean GAmma-ray Microscope) gamma multidetector array. Precise level attenuation method (DSAM). From the derived quadrupole moments, we find large differences in deformation between the yrast bands in neighbour nuclei explained in terms of the case of nuclei corresponding to an axis ratio of 2:1, the shell gaps are not fixed at a specific particle number and deformation. Furthermore the present results indicate that the deformations associated with identical bands are different supporting the picture that mass and deformation changes tend to compensate in SB bands with the same moments of inertia. (author). 114 refs.

1996-05-13

157

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

A heat resistant nickel base alloy which is excellent in not only hot and cold workability but also high temperature strength properties and which also possesses satisfactory oxidation resistance. The nickel base alloy consists essentially of 0.001-0.15 percent carbon, 0.0005-0.05 percent calcium, 20.0-126.0 percent chromium, 4.7-9.4 percent cobalt, 5.0-16.0 percent molybdenum, 0.5-4.0 percent tungsten, with the total of molybdenum plus tungsten being from 9.0 to 16.5 percent, and the balance nickel and inevitable impurities. The alloy may further contain one selected from the group consisting of (1) 0.3-1.5 percent aluminum and 0.1-1.0 percent titanium, (2) 0.001-0.30 percent at least one of yttrium and rare earth elements, and (3) 0.001-1.0 percent at least one of niobium, vanadium and tantalum, whereby the aforementioned characteristics are further enhanced.

1984-10-02

158

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

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

159

Electronic structure and nesting-driven enhancement of the RKKY interaction at the magnetic ordering propagation vector in Gd_2PdSi_3 and Tb_2PdSi_3

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

160

Effect of Ho^3^+ substitutions on the structural and magnetic properties of BaFe12O19 hexaferrites

We present first-time measurements of the Fermi surface and low-energy electronic structure of intermetallic compounds Gd_2PdSi_3 and Tb_2PdSi_3 by means of angle-resolved photoelectron spectroscopy (ARPES). We show that the Fermi surface in both compounds consists of an electron barrel at the #GAMMA# point surrounded by spindle-shaped electron pockets originating from the same band, with the band bottom of both features lying at 0.5 eV below the Fermi level. From the experimentally measured band structure, we estimate the momentum-dependent RKKY coupling strength and demonstrate that it is peaked at the 1/2#GAMMA# K wave vector. Comparison with neutron diffraction data from the same crystals shows perfect agreement of this vector with the propagation vector of the low-temperature in-plane magnetic order, thereby demonstrating the decisive role of the Fermi surface geometry in explaining the complex magnetically ordered ground state of ternary rare ...

2009-03-22

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161

British Library Electronic Table of Contents (United Kingdom)

Holmium doped barium based hexaferrites BaFe12-2xHo2xO19 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 (Ms), remanent magnetization (Mr) and coercivity (Hc) were observed by changing Ho^3^+ content in BaFe12-2xH...

2010-01-01

162

Double umbrella structure in terbium iron garnet

Development of pyro-separation technology based on molten salt electrolysis

The umbrella magnetic structure of the terbium iron garnet (TbIG) has been studied using neutron diffraction experiments peformed in the 4.2 to 650 K temperature range which covers both the Neel temperature (Tsub(N) = 550 +- 10 K) and the compensation temperature (Tsub(comp) = 244 +- 2 K). When T > Tsub(N), the observed peak intensities originate from nuclear contribution only. When Tsub(comp) < T < Tsub(N), the results have been interpreted in the Neel theory of ferrimagnetism. Below Tsub(comp), three salient features have been observed: there appears superstructure lines forbiden by the cubic space group Ia3d, whereas the other superstructure peaks are found absent contrary to other heavy rare earth garnets; the strongest reflexion (110) vanishes near Tsub(comp). The magnetic modes associated to the rhombohedral symmetry space group R(-3)c have been calculated; the two inequivalent magnetic sites C_1 and C'_1 of the Tb"3"+ ion have ...

1984-04-10

163

Development and cytotoxicity evaluation of SiAlONs ceramics

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

164

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

SiAlONs are ceramics with high potential as biomaterials due to their chemical stability, associated with suitable mechanical properties, such as high fracture toughness and fracture resistance. The objective of this work was to investigate the mechanical properties and the cytotoxicity of these ceramic materials. Three different compositions were prepared, using silicon nitride, aluminum nitride and a rare earth oxide mixture as starting powders, yielding Si_3N_4-SiAlON composites or pure SiAlON ceramics, after hot-pressing at 1750 deg. C, for 30 min. The sintered samples were characterized by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). Furthermore, hardness and fracture toughness were determined using the Vicker's indentation method. The biological compatibility was evaluated by in vitro cytotoxicity tests. Ceramic with elevated hardness, ranging between 17 and 21 GPa, and high fracture toughness of 5 to 6 MPa ...

2007-01-01

165

Laboratory evaluation of pipeline girth weld imperfections to determine their acceptability in sour gas service

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

166

Magnetic properties and magnetic ordering in the rare earth molybdenum(IV) pyrochlores: R_2Mo_2O_7

The influence of common welding defects such as internal under-cut, incomplete penetration of the root bead, internal concavity and hollow bead have been evaluated in a sour environment. Tests were performed on samples cut from actual pipeline welds. The individual defects were subjected to slow strain rate testing. The samples were then examined by metallography, scanning electron microscopy, and hardness testing. It was established that a threshold stress intensity exists for sulphide stress cracking. The test results were compared to those obtained from samples of the weld and pipe which did not contain any defects. This comparison indicated that the metallurgical variations associated with the presence of a weld are the main factor for sulphide stress cracking rather than any specific defects or geometry. 5 tabs., 9 figs.

1992-12-31

167

Electrospun Nanocomposite Fiber Mats of Zinc-Oxide Loaded Polyacrylonitrile

The series of cubic pyrochlore structure compounds, R_2Mo_2O_7 (R = Nd-Yb, Y; R not= Eu), were prepared as single phase materials by solid state reaction between R_2O_3 and MoO_2 at 1400 "0C in a CO/CO_2 = 1 buffer gas atmosphere. Lattice constants obtained from X-ray powder data compare well with results from previous studies. Magnetic susceptibility and magnetization data were obtained for all samples between 300 K and 4.2 K (700 K for R = Gd) and a range of applied fields. For R = Nd, Sm, and Gd magnetic ordering is observed at 97 K, 93 K and 83 K respectively which is assigned to ferromagnetism on the Mo(IV) sublattice. The Mo(IV) moment in the ordered state is about 1 #mu#/sub B/. At low temperatures, the Gd(III) and Mo(IV) moments are apparently coupled feromagnetically in Gd_2Mo_2O_7 yet the high temperature susceptibility data seem to indicate a ferrimagnetic (antiparallel) Gd(III)-Mo(IV) coupling. The low-temperature magnetic properties of Nd_2Mo_2O_7 and Sm_2Mo_2O_7 are ...

1986-01-01

168

Decomposition Mechanism of Waste Hard Metals using by ZDP (Zinc Decomposition Process)

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2008-06-01

169

Corrosion resistance of zinc coatings on depleted uranium and uranium alloys

Full Text Available

2011-03-01

170

Zinc-air battery/fuel cell

Simulated atmospheric corrosion studies were performed to determine the corrosion protection provided by galvanized zinc coatings on depleted uranium, U-0.75 Ti alloy, and U-6 Nb alloys. The accelerated ASTM tests consisted of exposing the galvanized samples to aqueous and aqueous chloride environments. The test results showed that anodic protection was provided by the electronegative zinc coatings on uranium and uranium alloys. Treating zinc with chromate conversion coatings also provided more protection.

1985-01-27

171

Zinc air battery development for electric vehicles. Final report

The zinc-air battery/fuel cell is an old technology invented one hundred years ago. However, there is renewed interest in this technology in response to the growing need for clean energy technology. The zinc-air battery/fuel cell is more attractive than similar technologies because its characteristics include high power density, safe operation and storage, and low cost. Zinc-air battery/fuel cells can be made in milliwatts to mega watts to accommodate different applications. The zinc-air battery/fuel cell has four major designs, namely primary, mechanically rechargeable, continuous feed and electrically rechargeable zinc-air battery/fuel cells. Among the different designs, the most common is the air cathode. There are 3 generations of catalysts used in the air cathodes. This paper discussed the different designs of the zinc-air battery/fuel cell, and more ...

2010-07-01

172

Zinc air battery development for electric vehicles

This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for the zinc electrode, with flow of electrolyte through the foam during battery operation. In this ``soluble`` zinc electrode the zincate discharge product dissolves completely in the electrolyte stream. Cycle testing at Lawrence Berkeley Laboratory, where the electrode was invented, and at MATSI showed that this approach avoids the zinc electrode shape change phenomenon. Further, electrolyte flow has been shown to be necessary to achieve significant cycle life (> 25 cycles) in this open system. Without it, water loss through the oxygen electrode results in high-resistance failure of the cell. The Phase I program, which focused ...

1991-07-01

173

Metal Coupled Folding of Cys2His2 Zinc-Finger

This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for the zinc electrode, with flow of electrolyte through the foam during battery operation. In this soluble'' zinc electrode the zincate discharge product dissolves completely in the electrolyte stream. Cycle testing at Lawrence Berkeley Laboratory, where the electrode was invented, and at MATSI showed that this approach avoids the zinc electrode shape change phenomenon. Further, electrolyte flow has been shown to be necessary to achieve significant cycle life (> 25 cycles) in this open system. Without it, water loss through the oxygen electrode results in high-resistance failure of the cell. The Phase I program, ...

1991-07-01

174

Regenerative zinc/air and zinc/ferricyanide batteries for stationary power applications

Zinc-fingers, which widely exist in eukaryotic cell and play crucial roles in life processes, depend on the binding of zinc ion for their proper folding. To computationally study the zinc coupled folding of the zinc-fingers, charge transfer and metal induced protonation/deprotonation effects have to be considered. Here, by attempting to implicitly account for such effects in classical molecular dynamics and performing intensive simulations with explicit solvent for the peptides with and without zinc binding, we investigate the folding of the Cys2His2 type zinc-finger motif and the coupling between the peptide folding and zinc binding. We find that zinc ion not only stabilizes the native structure, but also participates in the whole folding process. It binds to the peptide at early stage of folding, and directs or ...

2008-01-01

175

Depleted zinc: Properties, application, production

The authors report a novel configuration for a zinc-particle, packed-bed anode in which an open structure of high hydraulic permeability is maintained indefinitely in a cell with closely spaced walls by the formation of particle bridges and associated gaps. The configuration minimizes electrolyte pumping costs, allows rapid refueling and partial recharge, and provides for 100% zinc consumption. This approach benefits zinc/air fuel batteries by allowing nearly continuous operation and fuel recycle without commercial infrastructure; it benefits Zn/[Fe(CN){sub 6}]{sup {minus}3} batteries by eliminating shape-change and polarization problems found with planar anodes.

1994-05-01

176

Desulphurization of hot reducing gases in the entrained bed reactor

The addition of ZnO, depleted in the Zn-64 isotope, to the water of boiling water nuclear reactors lessens the accumulation of Co-60 on the reactor interior surfaces, reduces radioactive wastes and increases the reactor service-life because of the inhibitory action of zinc on inter-granular stress corrosion cracking. To the same effect depleted zinc in the form of acetate dihydrate is used in pressurized water reactors. Gas centrifuge isotope separation method is applied for production of depleted zinc on the industrial scale. More than 20 years of depleted zinc application history demonstrates its benefits for reduction of NPP personnel radiation exposure and combating construction materials corrosion.

2009-07-15

177

Effect of Non-aqueous Solvents on the Rate of Production of Copper Powder from Copper Sulphate Solution by Cementation on Stationary Zinc Sheet and Rotating Zinc Cylinder

Using an experimental pilot plant, designed and built for the tests, the influence of the following parameters was determined: desulphurization of the test gas, temperature, residence time in the reactor tube, concentration of the hydrogen sulphide and desulphurization agent, size of the particles which comprise the agent and composition of the gas. Allowance was made for the effect of calcination and carbonisation. Desulphurization was carried out with limestone on a gaseous mixture of CO and H/sub 2/. A mathematical description of the test findings and yield is presented. 8 refs.

1986-08-01

178

Scientific Electronic Library Online (English)

Abstract in english The rate of copper II/zinc cementation from copper sulphate solutions in the absence and in the presence of methanol (CH3OH) and dimethyl sulphoxide (DMSO) has been studied and the reaction was found to follow first-order kinetics. The influence of several parameters on the course of the reaction, such as cylinder rotation speed, initial concentration of Cu2+ ions, temperature and concentration of organic solvent, was investigated. In the case of CH3OH, rotating zinc cyli (more) nder was used, while in the presence of DMSO stationary zinc sheet and rotating zinc cylinder were used. It was found that (1) the percentage inhibition caused by methanol ranged from 10.70 to 58.38 depending on the concentration of the alcohol used; (2) the rate of cementation in the presence of DMSO using rotating zinc cylinder > the rate of cementation in the presence of DMSO using ...

2004-01-01

179

Regeneration of zinc anodes for the Electric Fuel{reg_sign} zinc-air refuelable EV battery system

Development of rechargeable monopolar and bipolar zinc/air batteries

The Electric Fuel Limited (EFL) refuelable zinc-air battery system is currently being tested in a number of electric vehicle demonstration projects, the largest of which is a field test of zinc-air postal vans sponsored chiefly by Deutsche Post AG (the German Post Office). The zinc-air battery is not recharged electrically, but rather is refueled through a series of mechanical and electrochemical steps that will require a special infrastructure in commercial application. As part of the German Post Office field test program, Electric Fuel designed and constructed a pilot zinc anode regeneration plant in Bremen, Germany. This plant is capable of servicing up to 100 commercial vans per week, which is adequate for the field test vehicle fleet. This paper will describe the design and operation of each of the areas and devices within the plant.

1997-12-31

180

Transcriptional repression and developmental functions of the atypical vertebrate GATA protein TRPS1

For the development of a rechargeable zinc/air battery, La[sub 0.6]Ca[sub 0.4]CoO[sub 3]-catalyzed (perovskite) bifunctional oxygen electrodes and pasted zinc electrodes were prepared and tested in monopolar zinc/air cells. In addition, a bipolar Zn/air stack was tested using reticulated copper foam as substrate for the zinc deposit. The cells were cycled in moderately alkaline ZnO-saturated electrolyte with KF as an electrolyte additive. The maximum power as well as the cycle life of the cells was investigated. The differences in porosity of the zinc electrode before and after the long-term test were analyzed using mercury porosimetry. (author) 8 figs., 13 refs.

1995-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

181

The electric fuel zinc-air battery option

Known vertebrate GATA proteins contain two zinc fingers and are required in development, whereas invertebrates express a class of essential proteins containing one GATA-type zinc finger. We isolated...Full Text Available

2001-04-02

182

The effects of zinc deficiency on pancreatic carboxypeptidase activity and protein digestion and absorption in the rat

With specific energy of more than 200 Wh/kg, the Electric Fuel zinc-air battery delivers as much as eight times the energy of lead-acid traction battery, more than twice the energy of the nearest advanced-battery competitor, and as much energy as a tank of gasoline. (author)

1995-12-31

183

Novel structural features in two ZHX homeodomains derived from a systematic study of single and multiple domains

1. Proteolytic enzyme activities were examined in the pancreas of zinc-deficient and control rats. 2. No change was detected in trypsin-plus-chymotrypsin activity. 3. Carboxypeptidase activity was...Full Text Available

1967-03-01

184

Genome-Wide Transcriptional Response of Chemostat-Cultured Escherichia coli to Zinc

BackgroundZhx1 to 3 (zinc-fingers and homeoboxes) form a set of paralogous genes encoding multi-domain proteins. ZHX proteins consist of two zinc fingers followed...Full Text Available

185

Epigallocatechin-3-gallate affects the growth of LNCaP cells via membrane fluidity and distribution of cellular zinc^*

Zinc is an essential trace metal ion for growth, but an excess of Zn is toxic and microorganisms express diverse resistance mechanisms. To understand global bacterial responses to excess Zn, we conducted...Full Text Available

2005-02-01

186

Effectiveness of zinc protoporphyrin/heme ratio for screening iron deficiency in preschool-aged children

Objective: To evaluate effects of epigallocatechin-3-gallate (EGCG) on the viability, membrane properties, and zinc distribution, with and without the presence of Zn²⁺, in human prostate...Full Text Available

2009-06-01

187

Cerebrospinal fluid zinc concentrations in febrile convulsions.

Hemoglobin and zinc protoporphyrin (ZPP) tests are commonly used to screen for iron deficiency, but little research has been done to systematically evaluate the sensitivity and specificity of these...Full Text Available

2011-02-01

188

Analysis of illegitimate genomic integration mediated by zinc-finger nucleases: implications for specificity of targeted gene correction

Zinc modulates the activity of glutamic acid decarboxylase, the rate limiting enzyme in the synthesis of gamma-aminobutyric acid (GABA), which is a major inhibitory neurotransmitter. Low cerebrospinal...Full Text Available

1995-10-01

189

Testing of a refuelable zinc/air bus battery

BackgroundFormation of site specific genomic double strand breaks (DSBs), induced by the expression of a pair of engineered zinc-finger nucleases (ZFNs), dramatically increases the...Full Text Available

190

Functional characterization of a CCCH type zinc-finger protein gene OsZF2 by ectopic overexpression of the gene in rice

We report tests of a refuelable zinc/air battery of modular, bipolar-cell design, intended for fleet electric busses and vans. The stack consists of twelve 250-cm{sup 2} cells built of two units: (1) a copper-clad glass-reinforced epoxy board supporting anode and cathode current collectors, and (2) polymer frame providing for air- and electrolyte distribution and zinc fuel storage. The stack was refueled in 4 min. by a hydraulic transfer of zinc particles entrained in solution flow.

1995-02-22

191

Effects of Varying Dietary Zinc Levels and Environmental Temperatures on the Growth Performance, Feathering Score and Feather Mineral Concentrations of Broiler Chicks

Full Text Available

2009-03-01

192

Diffusion Zink Planting of Steels

Full Text Available

2010-07-01

193

International Science & Technology Center (ISTC)

Research on Diffusion Zinc Cladding of Structural Steels, as Well as Their Mechanical and Corrosion Properties to Replace Their Cyanic Cadmium Plating

194

Development and cycle test of zinc-oxygen cells

Analysis of 24.4 MeV #alpha# particle scattering by even-even zinc isotopes

For the development of a rechargeable zinc/air battery, La{sub 0.6}Ca{sub 0.4}CoO{sub 3}-catalyzed (perovskite) bifunctional oxygen electrodes and pasted zinc electrodes were prepared and tested in monopolar zinc/air cells. The cells were cycled in moderately alkaline electrolyte. The maximum power as well as the cycle life of the cells were investigated. Up to 450 cycles could be reached, and attractive specific energies and powers were obtained. (author) 3 figs., 4 refs.

1995-07-01

195

The recovery of zinc and cadmium following 6.1 MeV alpha particle irradiation at 4.2 K

Short note. 2 refs.; 1 tab.

1990-04-10

196

Sequential extraction of heavy metals in river sediments of an abandoned pyrite mining area: pollution detection and affinity series

The paper reports the recovery of zinc and cadmium following 6.1 MeV alpha particle irradiation at 4.2 K as studied by means of electrical reistivity measurements. Specimens of 10 #mu#m thick have been used in order to obtain a homogeneous defect distribution over the whole thickness of the specimen. The pre-irradiation resistivity ratios were 700 and 750 for cadmium and zinc, respectively. (Auth.).

197

Sequential extraction of heavy metals in river sediments of an abandoned pyrite mining area: pollution detection and affinity series

In this paper heavy metal pollution at an abandoned Italian pyrite mine has been investigated by comparing total concentrations and speciation of heavy metals (Fe, Cu, Mn, Zn, Pb and As) in a red mud sample and a river sediment. Acid digestions show that all the investigated heavy metals present larger concentrations in the sediment than in the tailing. A modified Tessier's procedure has been used to discriminate heavy metal bound to organic fraction from those originally present in the mineral sulphide matrix and to detect a possible trend of metal mobilisation from red mud to river sediment. Sequential extractions on bulk and size fractionated samples denote that sediment samples present larger percent concentrations of the investigated heavy metals in the first extractive steps (I-IV) especially in lower dimension size fractionated samples suggesting that heavy metals in the sediment are significantly bound by superficial adsorption mechanisms. - ...

2004-11-01

198

Environmental Pollution Levels of Lead and Zinc in Ishiagu and Uburu Communities of Ebonyi State, Nigeria

In this paper heavy metal pollution at an abandoned Italian pyrite mine has been investigated by comparing total concentrations and speciation of heavy metals (Fe, Cu, Mn, Zn, Pb and As) in a red mud sample and a river sediment. Acid digestions show that all the investigated heavy metals present larger concentrations in the sediment than in the tailing. A modified Tessier's procedure has been used to discriminate heavy metal bound to organic fraction from those originally present in the mineral sulphide matrix and to detect a possible trend of metal mobilisation from red mud to river sediment. Sequential extractions on bulk and size fractionated samples denote that sediment samples present larger percent concentrations of the investigated heavy metals in the first extractive steps (I-IV) especially in lower dimension size fractionated samples suggesting that heavy metals in the sediment are significantly bound by superficial adsorption mechanisms. - Capsule: A ...

2004-11-01

199

British Library Electronic Table of Contents (United Kingdom)

Water and soil samples from the area were therefore analyzed for their lead and zinc content. Computation of pollution statuses of lead and zinc revealed topsoil lead geoaccumulation indices of ?0.143 and ?0.069 and zinc geoaccumulation indices of 1.168 and 0.713 for Ishiagu and Uburu respectively. The pollution indices were determined to be 0.499 and 0.3564 for soil in Ishiagu and Uburu respectively and also 5.11 and 2.42 for water in Ishiagu and Uburu communities respectively. Water/soil concentration ratio were found to be 0.0018 and 0.0014 for lead in Ishiagu and Uburu respectively. On the other hand, the water/soil concentration ratio for zinc was computed to be 0.001 and 0.0008 for Ishiagu and Uburu respectively. These results seem to suggest that the pollution of the environment by ...

2010-01-01

200

Bond strength of electrochemically-aged arc-sprayed zinc coatings on concrete

Synthesis, crystal structures and luminescence properties of the Eu3+-doped yttrium oxotellurates(IV) Y2Te4O11 and Y2Te5O13

Research was conducted to determine the effect of electrochemical aging on large area arc-sprayed zinc anodes for cathodic protection of bridges and other reinforced concrete structures. The study focused on the influence of total charge passed and concrete surface preparation on the bonding of the zinc to the concrete. Half of the samples were preheated prior to being arc-sprayed with zinc. The preheated samples had initial bond strengths that were 80% higher than the unheated samples. This difference in bond strength became insignificant after the passage of approximately 200 kC/m{sup 2} (5.2 A-h/ft{sup 2}) and bond strengths for all samples started to decrease after approximately 600 kC/m{sup 2} (15.5 A-h/ft{sup 2}). These changes in bond strength were correlated with observed changes in the permeability of the zinc coating to water, the electrical behavior of the zinc-concrete ...

1996-11-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

201

Preparation of vanadium III oxidic compounds, and dehydrogenation of paraffins

Y2Te4O11:Eu3+ and Y2Te5O13:Eu3+ single crystals in sub-millimeter scale were synthesized from the binary oxides (Y2O3, Eu2O3 and TeO2) using CsCl as fluxing agent. Crystallographic structures of the undoped yttrium oxotellurates(IV) Y2Te4O11 and Y2Te5O13 have been determined and refined from single-crystal X-ray diffraction data. In Y2Te4O11, a layered structure is present where the reticulated sheets consisting of edge-sharing [YO8]13- polyhedra are interconnected by the oxotellurate(IV) units, whereas in Y2Te5O13 only double chains of condensed yttrium-oxygen polyhedra with coordination numbers of 7 and 8 are left, now linked in two crystallographic directions by the oxotellurate(IV) entities. The Eu3+ luminescence spectra and the decay time from different energy levels of the doped compounds were investigated and all detected emission levels were identified. Luminescence properties of the Eu3+ cations have been interpreted in consideration of the now accessible detailed ...

2008-10-01

202

Preparation of vanadium III oxidic compounds and dehydrogenation of paraffins

A process is described for making a compound selected from a crystalline spinel of the formula A/sup II/V/sub 2-x//sup III/C/sub x//sup III/O/sub 4/ formula (1) or a crystalline perovskite of the formula D/sup III/V/sub 1-y//sup III/C/sub y//sup III/O/sub 3/ formula (2) from a pentavalent vanadium compound, where A is one or more of Mg, Zn, Mn, Fe, Co, Ni, Cu and Cd; D is one ore more of Y, the rare earths and Bi; C is one or more of Al, Ga, Cr, Fe and Co, x is zero to <2, and y is zero to<1. The process comprises (1) reducing a pentavalent vanadium oxidic compound to substantially the V/sup III/ state by heating at 100/sup 0/C. or less an aqueous medium slurry or solution of the pentavalent compound containing a reducing agent selected from hydrazine and a hydrocarbylhydrazine, (2) providing in the aqueous medium either before, during or after the reducing step, A/sup II/, D/sup III/ and C/sup III/ cations in solution in the ratio called ...

1988-04-12

203

Preparation and Crystal Structure of the Equiatomic Rare Earth Palladium Silicides NdPdSi, SmPdSi, alpha-GdPdSi, and alpha-TbPdSi

This patent describes the vapor phase catalytic dehydrogenation of a C/sub 2/-C/sub 4/ paraffin by contacting the paraffin with a spinel of the formula A/sup III/V/sub 2-x//sup III/C/sub x//sup III/O/sub 4/, formula (1) or a crystalline perovskite of the formula D/sup III/V/sub 1-y//sup III/C/sub y//sup III/O/sub 3/, formula (2) where A is one or more of Mg, Zn, Mn, Fe, Co, Ni, Cu and Cd; D is oone of more of Y, the rare earths and Bi; C is one or more of Al, Ga, Cr, Fe and Co, x is zero to < 1.9, and y is zero to < 0.9, which spinel or perovskite is made by a process which comprises (1) reducing a pentavalent vanadium oxidic compound to substantially the V/sup 111/ state by heating at 100/sup 0/C or less an aqueous medium slurry of solution of the pentavalent compound containing a reducing agent selected from hydrazine and a hydrocarbylhydrazine, (2) providing in the aqueous medium ether before, during or after the reducing step, A/sup ...

1988-08-09

204

Nonstoichiometry and diffusion in ceria and ceria solid solutions

The title compounds were prepared by arc-melting of the elemental components. Whereas NdPdSi and SmPdSi are already present after the arc-melting, alpha-GdPdSi and alpha-TbPdSi are formed only during the annealing at 800 degC. The four compounds crystallize with the recently reported alpha-YbAuGe type structure, which was refined for alpha-GdPdSi: Pnma, a=2108.0(4) pm, b=433.9(1) pm, c=745.6(1) pm, Z=12, R=0.026 for 1447 structure factors and 62 variable parameters. The lanthanoid atoms are situated between two-dimensionally infinite nets of condensed, puckered hexagons formed by alternating palladium and silicon atoms, with Pd-Si distances varying between 251 and 262 pm. In the third dimension these nets are linked via weak Pd-Pd (300 pm), Pd-Si (283 pm), and Si-Si bonds (261 pm). The refinements of the occupancy parameters suggested that ca. 2% of the palladium sites are occupied by silicon atoms and vice versa. The structural relationships between the two modifications of GdPdSi and ...

1999-01-01

205

Magnetic properties of Nd_2CuO_4-type R_2CuO_4 (R=Y, Dy, Ho, Er, Tm) synthesized under high pressure: Weak ferromagnetism of Y_2CuO_4

Some of the results of property measurements of CeO{sub 2} and its solid solutions were reviewed. The deviation from stoichiometry of undoped and doped CeO{sub 2} was presented in several figures, which suggested that CeO{sub 2} fired at high temperatures in air might be nonstoichiometric in some degree. At low temperatures, the deviation from stoichiometry in doped CeO{sub 2} is higher than undoped CeO{sub 2}. As another interesting property, CeO{sub 2} shows high solubility to trivalent cations such as rare earth elements. A possible reason behind this high solubility was presented. The nonstoichiometric defect in undoped CeO{sub 2} and the trivalent cation in solid solution with CeO{sub 2} have to be compensated by other defects. The possible defect structures in this solid solution were reviewed and the most probable structure was chosen based on density measurement and impurity dependence of oxygen diffusion coefficient. Finally the oxygen ...

2003-07-01

206

Luminescence Properties of ScPO{sub 4} Single Crystals

Magnetization of R_2CuO_4 (R=Y, Dy, Ho, Er, Tm) crystallizing in the Nd_2CuO_4-type (T') structure has been measured between 4 and 300 K. In Y_2CuO_4 antiferromagnetic ordering of Cu"2"+ spins at 260 K has been detected clearly, without being interfered with by the paramagnetic contribution of rare-earth elements as in the other compositions. Weak ferromagnetic behavior with a moment of 9x10"-"4 #mu#_B/Cu accompanies the antiferromagnetic transition. Dy"3"+, Ho"3"+, Er"3"+, and Tm"3"+ ions obey the Curie-Weiss law at relatively high temperatures, and the effective moments are in good agreement with the values anticipated from their lowest multiplet levels. Various types of deviations from the law occur at low temperatures. Specifically, a sharp kink possibly suggesting antiferromagnetic ordering of the Dy"3"+ moments has been found at 7 K. Anomalies around 200 K for Ho_2CuO_4 and Er_2CuO_4 reflect the weak ferromagnetic contribution of the CuO_2 lattice.

1990-10-01

207

Investigation of selected trace elements as nuclear forensics signatures

Flux-grown ScPO{sub 4} single crystals exhibit a number of luminescence bands in their x-ray-excited luminescence spectra - including sharp lines arising from rare-earth elements plus a number of broad bands at 5.6 cV, 4.4 eV, and 3 eV. The band at 5.6 eV was attributed to a self-trapped exciton (STE) [l], and it could be excited at 7 eV and higher energies. This luminescence is strongly polarized (P = 70 %) along the optical axes of the crystal and exhibits a kinetic decay time constant that varies from several ns at room temperature to {approximately}10 {micro}s at 60 K and up to {approximately}1 ms at 10 K. It is assumed that the STE is localized on the SC ions. The band at 3 eV can be excited in the range of the ScPO{sub 4} crystal transparency (decay time = 3 to 4 {micro}s.) This band is attributed to a lead impurity that creates different luminescence centers. At high temperatures, the band at 4.4 eV is dominant in the x-ray-excited TSL and afterglow spectra. ...

1999-08-16

208

International Symposium on Nuclear Energy SIEN 2009. Nuclear Power - A New Challenge

Nuclear material is either a product of technological processing of natural source material or it is entirely of anthropogenic origin. Consequently, nuclear material carries 'tool-marks' or 'fingerprints' of the process it was subjected to. Uranium fuels are examples of the first category, while plutonium belongs to the second category. The nature of these production processes is reflected in the elemental and isotopic composition of the material as well as in its microscopic and macroscopic appearance. All of these parameters can be determined using appropriate analytical techniques and they may result in important conclusions on the history and on the origin of the material. Therefore, they provide the most essential contribution to the prevention of future diversions of nuclear material from the same source. So far, essentially metallic impurities or light elements have been investigated for their potential in providing clues either on the type of process they originate from or on ...

209

Floating zone crystal growth of selected R2PdSi3 ternary silicides

The SIEN 2009 symposium organized by Romanian Nuclear Energy Association, AREN, in co-operation with Romanian Atomic Forum, ROMATOM, was primarily targeting the expert community involved in developing new nuclear power projects and implementing the National Nuclear Program. The symposium was also open as a discussion and information forum for scientists, engineers, technicians and students interested in scientific and technologic topics of Nuclear Power. It was structured in the following 6 sections: - Nuclear new builds and developments; - Operation, inspection and maintenance; - Increasing nuclear safety features; - Fuel cycle and decommissioning; - Public perception and confidence strengthening; - Environmental management. The symposium began with three plenary lectures dealing with: - Sustainable Nuclear Energy European Technology Platform; - Nuclear new-build; - Current issues of nuclear equipment standardization in Romania. A poster session of 5 presentations and a workshop ...

2009-10-12

210

Development of Novel Polycrystalline Ceramic Scintillators

Substitution of various rare earths R within the class of R2PdSi3 single crystals with hexagonal AlB2-type crystallographic structure reveals the systematic dependence of anisotropic magnetic properties governed by the interplay of crystal-electric field effects and magnetic two-ion interactions. Here we compare the floating zone (FZ) crystal growth with radiation heating of compounds with R = Tb, Tm, Pr, and Gd. The congruent melting behavior enabled moderate growth velocities of 3 to 5 mmh-1. The preferred growth directions are close to the basal plane of the hexagonal unit cell. The composition of the crystals, except of Tb2PdSi3, is slightly Pd-depleted with respect to the nominal composition 16.7 at.% Pd. Thin precipitates of RSi secondary phases were detected in the crystal matrix. Their phase fraction can be diminished by growth from Pd-rich melt compositions and annealing treatments. The compounds exhibit antiferromagnetic order below ...

2011-06-01

211

Crystal structure of ABPO{sub 5} and optical study of Pr{sup 3+} embedded in these compounds

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

2008-06-01

212

Crystal structure of ABPO_5 and optical study of Pr"3"+ embedded in these compounds

The crystal structure of borophosphates ABPO{sub 5} (A = alkaline earth or Pb) was resolved on a polycrystalline sample using the Rietveld method. The x-ray diffraction patterns data show that ABPO{sub 5} crystallize in a centrosymmetric space group P3{sub 1}21 and their structure is related to the borogermanates REBGeO{sub 5} with a stillwellite-type structure. Pr{sup 3+} ion was used as a local structural probe to corroborate the structural resolution results. Absorption and fluorescence spectra of A{sub 1-x}Pr{sub x}BP{sub 1-x}Ge{sub x}O{sub 5} (A alkaline earth or Pb; x = 0.05) have been investigated at different temperatures. At 9 K the 3{sup H}{sub 4}{yields}{sup 3}P{sub 0} transition of trivalent praseodymium ion (4f{sup 2} configuration) is observed as a single line. This indicates a unique crystallographic site for the rare earth ion in these compounds replacing the divalent cation. Energy level schemes were deduced from the ...

2001-10-22

213

Crystal fields in ROF:Tb{sup 3+} (R = La, Gd)

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

2001-10-22

214

Crystal fields in ROF:Tb"3"+ (R = La, Gd)

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

2004-10-20

215

Comparative study of the crystal field effects in rare earth oxynitrates

Laser excited luminescence and site selective excitation spectra of trivalent terbium (Tb"3"+) in two rare earth oxyfluoride (ROF) matrices, LaOF and GdOF, were detected at temperatures down to liquid helium. From the analyses of spectra, the crystal field (c.f.) fine structure of the "7F_J (J=0-6) ground multiplet was obtained for the 4f"8 electron configuration. The energy level schemes comprising 26 c.f. sublevels out of 33 allowed for the C_3_v point symmetry of the R"3"+ site were simulated according to a phenomenological model taking into account only the c.f. effect. The simulation including six c.f. parameters (B_0"2, B_0"4, B_3"4, B_0"6, B_3"6, and B_6"6) reproduced the experimental energy level schemes in a satisfactory manner with rms deviations of 5 and 6 cm"-"1 for the LaOF and GdOF hosts, respectively. The c.f. parameter sets are characterized by B_0"2 values close to zero while the fourth and sixth rank parameters assumed rather ...

2004-10-20

216

Zinc air battery development for electric vehicles

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

1994-06-01

217

Report on commissioned business for fiscal 1997. Development of new power storage system for cells and development of technology for distributed power storage (research for a zinc/air cell system for automobiles); 1997 nendo itaku gyomu hokokusho. Shingata denchi denryoku chozo system kaihatsu bunsangata denryoku chozo gijutsu kaihatsu (denki jidoshayo aen kuki denchi system chosa)

This document reports the progress and accomplishments of a 16 month program to develop a rechargeable zinc-air battery for electric vehicle propulsion, from October 1988 through January 1990. The program was the first stage in the transition of alkaline zinc electrode technology, invented at Lawrence Berkeley Laboratory, to private industry. The LBL invention teaches the use of a copper metal foam substrate for the zinc electrode, in combination with forced convection of electrolyte through the foam during battery operation. Research at LBL showed promise that this approach would avoid shape change (densification and dendrite growth), the primary failure mode of this electrode. The program comprised five tasks; (1) cell design, (2) capacity maximization, (3) cycle testing, (4) materials qualification, and (5) a cost/design study. The cell design contemplates a plate and frame stack, with alternating ...

1990-05-01

218

Zinc determination in medicinal powders by radionuclide X-ray fluorescence analysis

Concerning the above, it is discussed whether such a system is feasible in Japan. A zinc/air cell system requires some special plants for zinc regeneration, etc. It is necessary to build a zinc refining plant and to install dozens of electrode replacing facilities in an area dozens of kilometers in diameter with the plant at the center. For such a system to be functional, there have to be several tens of thousands of automobile users in a limited area. In Japan, so large a number will not be found anywhere even if the appeal is directed to those in the postal service and electric utilities. There will be no economic success in Japan, different from in Germany. As for the economic comparison between a zinc/air cell system and natural gas system, the two will be equivalent to each other as far as the use of the quick filling stations for the natural gas automobiles remains as it is. When the number in ...

1998-03-01

219

Moessbauer spectroscopy study of iron corrosion underneath painting system

X-ray fluorescence analysis was used to determine the zinc content of the ''Perilacin'' powder and the ZnO content of the ''Epiderman-pix'' powder. The characteristic Ksub(#alpha#) line of zinc was excited using a "1"4"7Pm/Mo source (10"7 s"-"1) and the molybdenum Ksub(#alpha#) line (17.47 keV). 4 to 5% Zn and 45 to 49% ZnO were determined with a NaI(Tl) scintillation detector. The radiation intensity was found to decrease with particle size. (M.K.).

1977-01-01

220

Modeling of an electrically rechargeable alkaline zinc-air battery

The effect of pigments on the development of corrosion products between the painting system and metal surface when exposed to marine environments has been discussed. The pigments studied were: red mud zinc chromate, zinc chromate, red oxide zinc phosphate, manganese phosphate barium chromate and basic lead silico chromate. Moessbauer spectroscopy revealed that the upper rust layer in all the cases consisted of #gamma#-Fe_2O_3, #gamma#-FeOOH and #alpha#-FeOOH. The lower rust layer immediately in contact with the metal surface consisted of an asymmetrical doublet due to #gamma#-FeOOH. (Auth.).

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221

Galvanic element with suspended electrode. Galvanisches Element mit suspendierter Elektrode

A numerical model has been developed to simulate the charging and discharge behaviour of an electrically rechargeable alkaline zinc-air battery. Further a galvanostatic experiment including three charge/discharge cycles has been performed. The cell voltages, the Zn electrode potentials versus a Zn reference, and the O{sub 2} electrode potentials versus a Zn reference calculated with the model are in fairly good agreement with the corresponding experimental data. The model is expected to be useful for zinc-air battery design and for analysis of experimental data. (author)

2003-03-01

222

Zinc/air battery R and D zinc/air engineering analysis for electrical vehicles: Tasks III, Final report

A zinc/air battery is claimed whose performance is improved by omitting separating elements such as diaphragms etc. The cathode and anode spaces are separated by a collector with holes big enough to permit the electrons to pass freely while restraining the anode material. Further, the active material consists of a spherical care of inert material with a zinc coating. Under the zinc coating, the spherical particles have another thin coating of an electropositive material, e.g. nickel. The cell also contains means for circulating the anode suspension.

1984-08-09

223

New developments in the Electric Fuel Ltd. zinc/air system

This report is an examination and analysis of the zinc-air system as the motive power source for electric vehicle propulsion. Various versions of the zinc-air system and operating schemes along with their advantages and disadvantages are discussed. Baseline cost calculations are also presented in order to compare the cost effectiveness of each of the systems. The treatise is conceptual in nature and is not based on new experimental work. The information is based on published literature and investigations carried out at ERC in the past. The study also includes recommendations and suggestions in areas that require further research and development work to achieve a smooth transition from the conceptual stage to a practical, viable, and cost effective system.

1986-12-01

224

Effect of zinc and its form of supply on production and quality of coffee beans

Electric Fuel Ltd. is engaged in the design, development and commercialization of its proprietary zinc/air battery technology for electric vehicles, consumer electronic products and defence applications. To meet the challenging requirements for propelling an all-electric bus, the Vehicle Division sought a unique solution: an all electric battery-battery hybrid propulsion system. The high energy zinc/air battery is coupled with a high-power auxiliary battery. The combined system offers zero emission, high power and long range in an economically viable package. The consumer battery group has developed a high power primary zinc/air cell aimed at cellular phone users, offering extended use, convenience and low cost. (orig.)

1999-07-01

225

British Library Electronic Table of Contents (United Kingdom)

Abstract BACKGROUND: In Brazil, the usual forms of zinc (Zn) supply to coffee plants have limitations that compromise the element availability to the plant. This study proposes to test an alternative approach to supplying the nutrient to Coffea arabica L. using trunk implanted zinc tablets. Additionally, the effect of Zn on the production and quality of coffee beans was also evaluated. RESULTS: The highest total coffee bean production was recorded in plants implanted with Zn tablets (TA), while the lowest was recorded in the control treatment, without zinc supply (WZn), reaching a bianual production of 188.2 and 130.1 60-kg bags of processed beans per hectare, respectively. In the treatments where Zn were applied as tablet implantation or as foliage spraying (SZn); the bean size was larger...

2011-01-01

226

Design and fabrication of a micro zinc/air battery

Comparative effects of ten dithiocarbamate and thiuram compounds on tissue distribution and excretion of lead in rats

Micro-batteries are one of the key components that restrict the application of autonomous Microsystems. However little efforts were made to solve the problem. We have proposed a new planar zinc/air micro-battery, suitable for autonomous microsystem applications. The micro-battery has a layered structure of zinc electrode/alkaline electrolyte/air cathode. A 3D zinc electrode with a high density of posts was designed to obtain a high porosity, hence to offer a best performance. A model of the micro-battery is developed and the device performances were simulated and discussed. A four-mask process was developed to fabricate the prototype micro-batteries. The preliminary testing results showed the micro-batteries is able to deliver a maximum power up to 5 mW, and with an average power of 100 {mu}W at a steady period for up to 2hrs. Fabrication process is still under optimization for further improvement.

2006-04-01

227

Acceptability of zinc-fortified, lipid-based nutrient supplements (LNS) prepared for young children in Burkina Faso

The dithiocarbamate and thiuram compounds, including disulfiram, were compared for their efficacies in influencing tissue distribution of a trace dose of intravenously injected lead plus "2"0"3Pb in rats. The tested compounds were sodium diethyldithiocarbamate (DEDTC), sodium dimethyldithiocarbamate (DMDTC), tetraethylthiuram disulfide (disulfiram), a complex of zinc and manganese ethylenebisdithiocarbamate (mancozeb), manganese ethylenebisdithiocarbamate (maneb), sodium monomethyldithiocarbamate (metham), zinc propylene bisdithiocarbamate (propineb), tetramethylthiuram disulfide (thiram), zinc ethylenebisdithiocarbamate (zineb), and zinc dimethyldithiocarbamate (ziram). The results of this study show that interactions can occur between lead and DEDTC, DMDTC, disulfiram, metham, thiram, and ziram, resulting in increased levels of lead in brain and probably potentiation of the neurotoxic effects of lead.

228

British Library Electronic Table of Contents (United Kingdom)

Abstract Micronutrient deficiencies are a public health concern among young children in low-income countries, and novel strategies are needed to improve the nutritional status of children at risk. One promising approach is the use of lipid-based nutrient supplements (LNS), which can be added to complementary food at the time of consumption. The optimal amount of zinc to include in LNS is uncertain, and concerns have been expressed about possible adverse effects of zinc on sensory characteristics of LNS. We conducted a series of acceptability studies of LNS containing either 0 or 10-mg of zinc per daily 20-g LNS dose among Burkinabe children 9-15 months old and their mothers. These acceptability studies included observations of children's consumption, maternal and child sensory reaction to ...

2011-01-01

229

The significance of local hard zones on the outside of pipeline girth welds: Further studies

Technical-economic aspects of the utilization of geothermal waters

The NACE MR-01-75 standard imposes a restriction of 22HRC maximum for regions of a pipeline girth weld that are not in direct contact with H[sub 2]S containing environments. TWI have demonstrated in an earlier project for the Pipeline Research Committee (PRC) that it may be permissible to relax this maximum hardness requirement. Such a relaxation, which already exists in the BS4515: 1984 standard, offers potential benefits when applied to the capping pass and heat affected zone of a pipeline girth weld. This report presents additional data to supplement that obtained in a previous PRC project conducted at TWI. Further pipe materials with differing pipe wall thicknesses have been welded, exposed to an internal H[sub 2]S containing environment and examined for sulphide stress corrosion cracking.

1991-10-01

230

Removal of 106Ru traces from NH4NO3 effluent generated during recycling of sintered depleted uranium fuel pellets

A brief description is given of the physico-chemical parameters characterized a hot water geothermal reservoir and of its exploitation by means of single or coupled (doublet) wells. The technical aspects of geothermal heat to the users is then discussed, beginning with corrosion of materials caused by seven main agents: oxygen, hydrogen sulphide, carbon dioxide, ammonia, hydrogen, sulphates and chlorides. A brief mention is made of scaling due to calcium carbonate, silica and calcium sulphates. The basic components of a geothermal plant for non-electric uses are then discussed: production pumps, surface pipelines, heat exchangers, heat pumps and reinjection pumps. The advantages and disadvantages of the different equipment and materials used in the geothermal sector are also presented. A list is also given of the criteria used in the energy and economic balance of a geothermal operation. (author). 24 refs, 13 figs, 2 tabs.

231

British Library Electronic Table of Contents (United Kingdom)

Feasibility of using fixed bed column of conventional ion exchangers/sorbent and chemical precipitation based processes have been examined for the effective removal of the very low levels of 106Ru activity from NH4NO3 effluent generated during wet processing of rejected sintered depleted uranium fuel pellets. Based on the results, a simple process involving precipitation of cobalt sulphide along with ferric hydroxide was selected and further optimization of process variables was carried out. The optimized process has been found to be highly efficient in reducing 106Ru activity down to extremely low levels.

2011-01-01

232

Hydrothermal faunal assemblages and habitat characterisation at the Eiffel Tower edifice (Lucky Strike, Mid-Atlantic Ridge)

British Library Electronic Table of Contents (United Kingdom)

Abstract The Eiffel Tower edifice is situated in the Lucky Strike hydrothermal vent field at a mean depth of 1690-m on the Mid-Atlantic Ridge (MAR). At this 11-m-high hydrothermal structure, different faunal assemblages, varying in visibly dominant species (mussels and shrimp), in mussel size and in density of mussel coverage, were sampled biologically and chemically. Temperature and sulphide (-S) were measured on the different types of mussel-based assemblages and on a shrimp-dominated assemblage. Temperature was used as a proxy for calculating total concentrations of CH4. Based on the physico-chemical measurements, two microhabitats were identified, corresponding to (i) a more variable habitat featuring the greatest fluctuations in environmental variables and (ii) a second, more stable, ...

2011-01-01

233

Effect of carbon dioxide on the performance of biogas/diesel dual-fuel engine

Application of remote sensing and geophysics to the detection and monitoring of acid mine drainage

Methane and carbon dioxide are the two main constituents of biogas. Biogas also contains traces of nitrogen, hydrogen, oxygen and hydrogen sulphide. When diesel engine runs on biogas, the combustion is poor as compared to diesel fuel. One of the reasons of poor combustion is the presence of carbon dioxide in the biogas. Percentage of methane and carbon dioxide in biogas varies with maturities of feed stock, temperature, water content, loading rate of raw material and bacterial actions. This paper examines the effect of variations of carbon dioxide in biogas on the performance of the engine to simulate the performance of the engine running with biogas from different sources (varying proportion of methane and carbon dioxide). (Author)

1996-09-01

234

The Refuelable Zinc-air Battery: Alternative Techniques for Zinc and Electrolyte Regeneration

The results of a study on the application of remote sensing and geophysical methods for the detection and monitoring of acid mine drainage (AMD) are summarized, with emphasis on those that appear most suitable. The study consisted of a literature review, an information survey of users and suppliers, and discussions with various experts. Space-borne sensors, airborne sensors, airborne videography and digital frame cameras, spectroradiometers, radar, and photographic data are considered. Geophysical methods are effective for measurement of sulphides, areas of active chemical oxidation, acid mine drainage, and contaminated ground water movement. The popularity and effectiveness of various geophysical methods are rated for AMD applications. 25 refs., 1 fig., 3 tabs.

1995-06-01

235

Spectroscopic characterization and temporal dynamics of energy transfer process between Tm{sup 3+} -Ho{sup 3+} and Yb{sup 3+} -Tm{sup 3+} ions in LiYF{sub 4} and LiLuF{sub 4} crystals; Caracterizacao espectroscopica e dinamica temporal dos processos de transferencia de energia entre os ions Tm{sup 3+} -Ho{sup 3+} e Yb{sup 3+} -Tm{sup 3+} em cristais de LiYF{sub 4} and LiLuF{sub 4}

An investigation was conducted into alternative techniques for zinc and electrolyte regeneration and reuse in the refuelable zinc/air battery that was developed by LLNL and previously tested on a moving electric bus using cut wire. Mossy zinc was electrodeposited onto a bipolar array of inclined Ni plates with an energy consumption of 1.8 kWh/kg. Using a H{sub 2}-depolarized anode, zinc was deposited at 0.6 V (0.8 kA/m{sup 2}); the open circuit voltage was 0.45 V. Three types of fuel pellets were tested and compared with results for 0.75 mm cut wire: spheres produced in a spouted bed (UCB); coarse powder produced by gas-atomization (Noranda); and irregular pellets produced by chopping 1-mm plates of compacted zinc fines (Eagle-Picher, Inc.). All three types transported within the cell. The coarse powder fed continuously from hopper to cell, as did the compacted pellets (< ...

2006-01-19

236

bring scheme, buy recycled, recycled products, producer responsibility, environment, environmental, household waste, municipal waste, paper recycling

In this work, we perform spectroscopic studies to characterize the energy transfer processes occurring in rare-earth doped lithium fluoride systems, aiming the optimization of the population inversion of these media. Yb{sup 3+} ion was used in order to probe the electron-phonon coupling in LiYF{sub 4}, LiGdF{sub 4} and LiLuF{sub 4} matrices. In these systems it was obtained the average phononenergy, the vibronic transition probability and Huang-Rhys coupling constant. These parameters are dependent on the crystal host and the LiLuF{sub 4} system presents excluded correlation effects, an electronic repulsion that weakens the vibronic coupling. The Tm:Ho:LiYF{sub 4} system was studied under diode laser pumping at 796 nm, aiming the 2 {mu}m emission optimization. The ideal conditions of concentration and laser power were determined favouring the latter emission. Upconversion processes of two photons were identified besides the energy transfer among ions. The dynamic ...

2001-07-01

237

Wastenet

... Zinc-carbon/air and alkaline-manganese batteries can be reprocessed using a number of different methods, which include smelting and other thermal-metallurgical processes to ... Citron in France - thermal-metallurgical reprocessing primarily of zinc-carbon/air and alkaline-manganese (including older ones containing mercury), but also NiMH, ...

238

Zinc/air technology, December 1993 meeting report

Zinc tetraaminophthalocyanine-Fe₃O₄ nanoparticle composite for laccase immobilization

A Zinc/Air Battery Review and Strategic Planning Meeting was held in 1993. One outcome of the meeting was recognition of the need for a report on the current status of the technology. This report contains contributions from many of the attendees at the above meeting and expresses their views on where the technology is today and what could/should be done to improve its performance.

1994-10-01

239

The relationship between seminal plasma zinc levels and high molecular weight zinc binding protein and sperm motility in Iraqi infertile men

Zinc tetraaminophthalocyanine-Fe₃O₄ nanoparticle composites were prepared by organic-inorganic complex technology and characterized. It has been proved that the ZnTAPc dispersed...Full Text Available

2007-12-01

240

Energy density ten times as high; Energy engineering: Zinc/air battery systems on trial. Dichte verzehnfacht; Energietechnik: Zink-Luft-Batteriesystem im Test

To evaluate the relationship between sperm motility and total seminal plasma zinc concentration and high molecular weight zinc bound protein values in infertile Iraqi men. A case-control study was conducted at the Chemistry and Biochemistry Department, College of Medicine, Al-Nahrain University, Baghdad, Iraq between March 2005 to February 2006. The subjects for the study included 60 infertile male patients who were recruited Al-Kadhimiya Teaching Hospital, and Institute of Embryo Research and Infertility Treatment, Baghdad, Iraq. They were categorized according to their seminal parameters to oligozoospermia (n=32), azoospermia (n=22), and asthenozoospermia (n=6). Thirty nine fertile men (age range 31.87 +/- 3.76 years) were selected as controls, whose partners had conceived within the last year before participation with this study, and having normal spermiogram parameters. Seminal plasma zinc concentration and high ...

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241

Battery using a metal particle bed electrode

Prior to an industrial-scale test of zinc/air batteries at Greven, the TUeV Bayern-Sachsen carried out preliminary tests on behalf of the Deutsche Bundespost. The results were quite promising: The energy density of the new battery is ten times as high as that of conventional lead batteries, and the battery-powered test vehicle had a range of up to 300 km. (orig.)

1994-01-01

242

Battery using a metal particle bed electrode

A zinc-air battery in a case including a zinc particle bed supported adjacent the current feeder and diaphragm on a porous support plate which holds the particles but passes electrolyte solution. Electrolyte is recycled through a conduit between the support plate and top of the bed by convective forces created by a density of differential caused by a higher concentration of high density discharge products in the interstices of the bed than in the electrolyte recycle conduit.

1991-01-01

243

Alkaline rechargeable zinc-air battery; Alkalische wiederaufladbare Zink-Luft Batterie

A zinc-air battery in a case is described including a zinc particle bed supported adjacent the current feeder and diaphragm on a porous support plate which holds the particles but passes electrolyte solution. Electrolyte is recycled through a conduit between the support plate and top of the bed by convective forces created by a density of differential caused by a higher concentration of high density discharge products in the interstices of the bed than in the electrolyte recycle conduit. 7 figures.

1991-04-09

244

#alpha#-particle irradiation damage and stage I recovery in zinc

Because of its high energy density, compatibility with aqueous electrolytes and the low toxicity of its active materials, the zinc-air battery system is an interesting candidate for electric vehicle applications. The use of O{sub 2} from the air as a reactant requires a partially open cell construction and a technologically challenging air interface. This report describes the research and development program at the Paul Scherrer Institute which finally led to the demonstration of a durable, electrically rechargeable zinc-oxygen battery. In a first phase the research program was focused on the development of bifunctional oxygen diffusion electrodes and pasted zinc electrodes. The current-potential behaviour and the cycle life performance of anodes and cathodes was tested in single electrode measurements (three-electrode arrangements) as well as in complete monopolar zinc-oxygen and ...

1996-11-01

245

Novel alloys to improve the electrochemical behavior of zinc anodes for zinc/air battery

Defects are produced in zinc by 6.1 MeV #alpha#-particle irradiation at 4.2 K and the subsequent recovery between 4.2 and 22 K. No evidence is found for free migration of an interstitial in the temperature range investigated. The recovery spectra reveal a series of substages which are ascribed to recombination of close Frenkel pairs. (author).

246

Feasibility study of a new zinc-air battery concept using flowing alkaline electrolyte

In our continued efforts for improving the performance of zinc anodes for a Zn/air battery, we now report the preparation of three alloys and improved performances of anodes made up with these alloys. The alloys contained zinc, nickel, and indium with different weight percentages and were calcined at two different temperatures. Out of the six alloys, the alloy which has a composition of zinc 90%, nickel 7.5% and Indium 2.5% and fired at 500{sup o}C is found to be the best. In the case of the hydrogen evolution reaction, this alloy had its potential shifted to a more negative potential. As far as the cyclic voltammograms were concerned, the difference between the anodic and cathodic part was minimal when compared with other alloys. Surprisingly, this alloy had reversibility even after 100 cycles of the cyclic voltammogram. This is a clear indication that dendrite formation was reduced to a considerable extent. Images taken ...

2006-10-06

247

The platinum group elements and gold: analysis by radiochemical and instrumental neutron activation analysis and relevance to geological exploration and related problems

Proof-of-principle experiments are reported for a new concept in electrically rechargeable zinc-air battery. The zinc electrode is a porous flow-thru type using a copper foam metal substrate with zinc deposition onto the foam metal from concentrated zincate electrolyte (as used in zinc-slurry type batteries). The bifunctional air electrode employs low-cost materials, being fabricated entirely from carbon-based precursors and small amounts of nickel and/or cobalt oxide. Corrosion measurements on the graphite materials in the air electrode indicate sufficient corrosion resistance for 8000 h life on charge. A prototype single cell was constructed having 1.5 Ah capacity producing 1.2 V discharge -2.0 charge at the three hour rate and has produced stable voltages for more than 150 cycles. Based on the 1.5 Ah prototype characteristics, design calculations for a 32 kWh battery project an energy density of ...

1986-04-01

248

Production and characterisation of the transition metal chalcogenides MoS[sub 2], MoSe[sub 2], WS[sub 2] and WSe[sub 2] as thin films in photovoltaics. Herstellung und Charakterisierung der Uebergangsmetallchalkogenide MoS[sub 2], MoSe[sub 2], WS[sub 2] und WSe[sub 2] als Duennfilme fuer die Photovoltaik

This paper presents an overview of research conducted with the support of the Australian Institute of Nuclear Science and Engineering, at the University of Melbourne, School of Earth Sciences, Radiochemical Neutron Activation Laboratory. The primary objective of this research is to realize the high potential of the platinum group elements (PGE) and gold to the solution of petrogenetic problems, the study of magma generation and magmatic processes in mafic/ultramafic rock suites, as tracers in hydrothermal ore formation. The PGEs (Os, Ru, Ir, Pt, Pd and Rh) are among the least abundant of all elements on earth with unique properties such as high melting points, high electrical and thermal conductivity, high density, strength and toughness as alloys. They exhibit both siderophile and chalcophile characteristics and are valuable tools in providing information about magmatic processes, in particular S-saturation, as well as crystal fractionation trends. Two distinct groups of PGEs are ...

1996-12-31

249

Separation and determination of cadmium and zinc as their thenoyltrifluoroacetone complexes with dibenzo-18-crown-6 by means of synergistic extraction and atomic absorption spectrometry

The production and characterisation of thin films made from molybdenum sulphide, molybdenum selenide, tungsten sulphide and tungsten selenide are described. The electronic properties of the thin films were examined by Hall measurements and by thermal sensors. For the MoSe[sub 2] films, the majority of the samples were n-conducting and p-conduction was only found for a few examples. All the other films (MoS[sub 2], WS[sub 2], WSe[sub 2]) were p-conducting. The electrical transport properties of the thin films are comparable to those of single crystals. With these thin films as absorber materials, it was possible for the first time to produce the polycrystalline solid n-ZnO/p-MoSe[sub 2], n-ZnO/WSe[sub 2], n-ZnO/WS[sub 2]- and n-ITO/WS[sub 2] solar cells. In spite of not yet optimized diode geometry (lateral build-up), a maximum short circuit current of I[sub SC] = 18 mA/cm[sup 2] was achieved for the MoSe[sub 2] diode. (orig.)

1993-01-01

250

Paper-based, printed zinc-air battery

A new method for the separation and determination of trace amounts of cadmium and zinc in water as their thenoyltrifluoroacetone (TTA) complexes with dibenzo-18-crown-6 (DB18C6) in o-dichlorobenzene has been established by means of synergistic extraction and back-extraction combined with atomic absorption spectrometry. The effect of various factors (synergism with TTA and DB18C6, shaking time, composition of the extracted species, and mutual separation etc.) on the extraction and back-extraction of cadmium and zinc has been in- vestigated. When the mixtures were extracted for 4 min at pH 4.9, only zinc was extracted quantitatively, whereas cadmium remained in the aqueous phase. After the phases were separated, cadmium was again extracted quantitatively at pH 7.5. Then, the two phases were each shaken with 0.05-0.1 mol/l HCl in order to back-extract cadmium and zinc from the organic phases; the ions were ...

1997-01-01

251

The roles and electrochemical characterizations of activated carbon in zinc air battery cathodes

A flexible battery is printed on paper by screen-printing a zinc/carbon/polymer composite anode on one side of the sheet, polymerising a poly(3,4-ethylenedioxythiophene) (PEDOT) cathode on the other side of the sheet, and applying a lithium chloride electrolyte between the two electrodes. The PEDOT cathode is prepared by inkjet printing a pattern of iron(III)p-toluenesulfonate as a solution in butan-1-ol onto paper, followed by vapour phase polymerisation of the monomer. The electrolyte is prepared as a solution of lithium chloride and lithium hydroxide and also applied by inkjet printing on to paper, where it is absorbed into the sheet cross-section. Measurements on a zinc/carbon-PEDOT/air battery in a similar configuration on a polyethylene naphthalate substrate shows a discharge capacity of up to 1.4 mAh cm{sup -2} for an initial load of 2.5 mg zinc, equivalent to almost 70% of the zinc content of ...

2009-12-01

252

SYNERGISTIC EFFECT OF N,N-BIS(PHOSPHONOMETHYL) GLYCINE AND ZINC IONS IN CORROSION CONTROL OF CARBON STEEL IN COOLING WATER SYSTEMS

We prepared cathodes with various types of activated carbon and measured the cathodes' electrochemical performance according to the kind of activated carbon. Activated carbon supplies airflow channels and reaction sites in the cathode of zinc air batteries. When we use activated carbon with a high specific surface area as the cathode's catalyst substrate, we expect high electrochemical performance because this type of carbon provides more air flow channels and reaction sites. We focused on investigating the relationship between the cathode's pore structure and its electrochemical characterizations. We also studied the effects of the various activated carbon materials on the zinc air batteries' performance. Increasing the macropores or mesopores in the activated carbon resulted in achieving more power from the battery. (author)

2006-12-01

253

British Library Electronic Table of Contents (United Kingdom)

A protective film has been developed on the surface of carbon steel in low chloride aqueous environment using a synergistic mixture of an environmentally friendly phosphonic acid, N,N-bis(phosphonomethyl) glycine (BPMG), and zinc ions. Impedance studies of the metal/solution interface indicated that the surface film is highly protective against the corrosion of carbon steel in the chosen environment. Potentiodynamic polarization studies showed that the inhibitor is a mixed inhibitor. X-ray photoelectron spectroscopic analysis (XPS) of the film showed the presence of the elements iron, phosphorus, nitrogen, oxygen, carbon, and zinc. Deconvolution spectra of these elements in the surface film showed the presence of oxides/hydroxides of iron(III), Zn(OH)2, and [Zn(II)-BPMG] complex. This infe...

2011-01-01

254

Raney-platinum film electrodes for potentially implantable glucose fuel cells. Part 1: Nickel-free glucose oxidation anodes

British Library Electronic Table of Contents (United Kingdom)

We present a novel fabrication route yielding Raney-platinum film electrodes intended as glucose oxidation anodes for potentially implantable fuel cells. Fabrication roots on thermal alloying of an extractable metal with bulk platinum at 200^oC for 48h. In contrast to earlier works using carcinogenic nickel, we employ zinc as potentially biocompatible alloying partner. Microstructure analysis indicates that after removal of extractable zinc the porous Raney-platinum film (roughness factor ~2700) consists predominantly of the Pt3Zn phase. Release of zinc during electrode operation can be expected to have no significant effect on physiological normal levels in blood and serum, which promises good biocompatibility. In contrast to previous anodes based on hydrogel-bound catalyst particles the ...

2010-01-01

255

Lead, copper and zinc biosorption from bicomponent systems modelled by empirical Freundlich isotherm

Functional domain analysis of glass, a zinc-finger-containing transcription factor in Drosophila.

The biosorption of lead, copper and zinc ions on Rhizopus arrhizus has been studied for three single-component and two binary systems. The equilibrium data have been analysed using the Freundlich adsorption model. The characteristic parameters for the Freundlich adsorption model have been determined and the competition coefficients for the competitive biosorption of Pb(II)-Cu(II) at pH 4.0 and 5.0, and Pb(II)-Zn(II) at pH 5.0 have been calcualted. For the individual single-component isotherms, lead has the highest biosorption capacity followed by copper, then zinc. The capacity of lead in the two binary systems is always significantly greater than those of the other metal ions, in agreement with the single-component data. Only a partial selectivity for copper ions has been obtained at pH 4.0. (orig.)

2000-07-01

256

Zinc release from thapsigargin/IP3-sensitive stores in cultured cortical neurons

The glass gene is required for proper photo-receptor differentiation during development of the Drosophila eye glass codes for a DNA-binding protein containing five zinc fingers that we show is a transcriptional activator. A comparison of the sequences of the glass genes from two species of Drosophila and a detailed functional domain analysis of the Drosophila melanogaster glass gene reveal that both the DNA-binding domain and the transcriptional-activation domain are highly conserved between the two species. Analysis of the DNA-binding domain of glass indicates that the three carboxyl-terminal zinc fingers alone are necessary and sufficient for DNA binding. We also show that a deletion mutant of glass containing only the DNA-binding domain can behave in a dominant-negative manner both in vivo and in a cell culture assay that measures transcriptional activation. PMID:7604032

1995-07-01

257

The Zinc Finger SET Domain Gene Prdm14 Is Overexpressed in Lymphoblastic Lymphomas with Retroviral Insertions at Evi32

BackgroundChanges in ionic concentration have a fundamental effect on numerous physiological processes. For example, IP₃-gated thapsigargin sensitive intracellular calcium...Full Text Available

258

Targeted plasmid integration into the human genome by an engineered zinc-finger recombinase

BackgroundAKXD recombinant inbred strains of mice have proven to be very useful in the identification of potential oncogenes and tumor suppressors involved in the development of...Full Text Available

259

Silver nanoparticle-decorated carbon nanotubes as bifunctional gas-diffusion electrodes for zinc-air batteries

The development of new methods for gene addition to mammalian genomes is necessary to overcome the limitations of conventional genetic engineering strategies. Although a variety of DNA-modifying enzymes...Full Text Available

2011-09-01

260

Sequences homologous to the human x- and y-borne zinc finger protein genes (ZFX/Y) are autosomal in monotreme mannals

Thin, lightweight, and flexible gas-diffusion electrodes (GDEs) based on freestanding entangled networks of single-walled carbon nanotubes (SWNTs) decorated with Ag nanoparticles (AgNPs) are tested as the air-breathing cathode in a zinc-air battery. The SWNT networks provide a highly porous surface for active oxygen absorption and diffusion. The high conductivity of SWNTs coupled with the catalytic activity of AgNPs for oxygen reduction leads to an improvement in the performance of the zinc-air cell. By modulating the pH value and the reaction time, different sizes of AgNPs are decorated uniformly on the SWNTs, as revealed by transmission electron microscopy and powder X-ray diffraction. AgNPs with sizes of 3-5 nm double the capacity and specific energy of a zinc-air battery as compared with bare SWNTs. The simplified, lightweight architecture shows significant advantages over conventional carbon-based GDEs in terms of ...

2010-07-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

261

Radionuclide X-ray fluorescence analysis of waste water from the production of citric acid

The human zinc finger protein genes (ZFX/Y) were identified as a result of a systematic search for the testis-determining factor gene on the human Y chromosome. Although they play no direct role in sex determination, they are of particular interest because they are highly conserved among mammals, birds, and amphibians and because, in eutherian mammals at least, they have active alleles on both the X and the Y chromosomes outside the pseudoautosomal region. We used in situ hybridization to localize the homologues of the zinc finger protein gene to chromosome 1 of the Australian echidna and to an equivalent position on chromosomes 1 and 2 of the playtpus. The localization to platypus chromosome 1 was confirmed by Southern analysis of a Chinese hamster [times] platypus cell hybrid retaining most of platypus chromosome 1. This localization is consistent with the cytological homology of chromosome 1 between the two species. The ...

1993-02-01

262

Radionuclide X-ray fluorescence analysis of waste water from the production of citric acid

Radionuclide X-ray fluorescence analysis was used for the determination of iron, calcium, potassium, copper, manganese and zinc in waste water from the production process of citric acid.

1982-02-18

263

Osterix Overexpression in Mesenchymal Stem cells Stimulates Healing of Critical-Sized Defects in Murine Calvarial Bone

Radionuclide X-ray fluorescence analysis was used for the determination of iron, calcium, potassium, copper, manganese and zinc in waste water from the production process of citric acid. (author).

1982-02-01

264

Human intronic enhancers control distinct sub-domains of Gli3 expression during mouse CNS and limb development

Osterix (Osx) is a zinc-finger-containing transcription factor that is expressed in osteoblasts of all endochondral and membranous bones. In Osx null ...Full Text Available

2007-10-01

265

German connections behind EFL's Zn-air

BackgroundThe zinc-finger transcription factor GLI3 is an important mediator of Sonic hedgehog signaling and crucial for patterning of many aspects of the vertebrate body plan. In...Full Text Available

266

Economic evaluation of the solar carbothermic reduction of ZnO by using a single sensitivity analysis and a Monte-Carlo risk analysis

This paper describes a new concept in zinc-air battery technology and provides and insight into the role of the German Post Office and its former chairman in its commercial promotion. (UK)

1994-10-01

267

Corrosion and histopathological studies on anode materials for implantable power sources. [In vivo corrosion studies on anode material

The technical feasibility of the solar carbothermal reduction of ZnO has been successfully demonstrated in a pilot plant. The economics of this process is addressed by means of a single sensitivity analysis and a Monte-Carlo risk analysis. A medium-term and a long-term scenario have been investigated, each for a 5 and a 30 MW{sub th} plant. For a discount rate of 15% the zinc production costs vary between 482 and 245 $/t for the medium-term scenario and between 312 and 146 $/t for the long-term scenario, respectively. These costs do not account for the zinc oxide input material. In addition, a risk analysis was conducted for the 30 MW{sub th} long-term scenario. For each input parameter, a probability distribution was estimated and the probability distribution of the zinc production cost was calculated by means of a Monte-Carlo method. The expected mean zinc production costs vary from 95 $/t for a ...

2007-07-15

268

Contribution to the radionuclide x-ray fluorescence analysis of human blood and plasma

The biocompatibility and corrosion resistance of various materials for use as sacrificial anodes in in vivo hybrid fuel cells were studied. Aluminium, zinc, and magnesium alloy AZ31B were studied, and the results are discussed.

1974-01-01

269

Citrate Process Flue Gas Desulfurization Demonstration Plant.

A photon-induced x-ray fluorescence method allowing the simultaneous determination of iron, copper, zinc, bromine and rubidium in human blood and blood plasma samples is described. The method is reliable and has a good sensitivity for a wide range of elements. (author).

1986-04-01

270

Cadmium, Lead, and Other Metals in Relation to Semen Quality: Human Evidence for Molybdenum as a Male Reproductive Toxicant

At the St. Joe Minerals Corp.'s zinc smelter powerplant, an SO2 emission control program evolved into a cooperative program with the Bureau of Mines for installation and initial operation of a citrate process flue gas desulfurization demonstration plant. ...

1983-01-01

271

Atmospheric corrosion in Gran Canaria specifically meteorological and pollution conditions.

BackgroundEvidence on human semen quality as it relates to exposure to various metals, both essential (e.g., zinc, copper) and nonessential (e.g., cadmium, lead), is inconsistent....Full Text Available

2008-11-01

272

Assessment of battery technologies for electric vehicles

Carbon steel, copper, zinc and aluminium samples were exposed in different sizes with known ambient parameters in Gran Canaria Island and atmospheric corrosion was investigated. Weight-loss measurements used to determine corrosion damage were complemented...

1998-01-01

273

A Novel Nuclear-Localized CCCH-Type Zinc Finger Protein, OsDOS, Is Involved in Delaying Leaf Senescence in Rice1[W

This document, Part 2 of Volume 2, provides appendices to this report and includes the following technologies, zinc/air battery; lithium/molybdenum disulfide battery; sodium/sulfur battery; nickel/cadmium battery; nickel/iron battery; iron/oxygen battery and iron/air battery. (FI)

1990-02-01

274

Zn/gelled 6M KOH/O{sub 2} zinc-air battery

Leaf senescence is a developmentally programmed degeneration process, which is fine tuned by a complex regulatory network for plant fitness. However, molecular regulation of leaf senescence is poorly...Full Text Available

2006-08-01

275

Rechargeable zinc/manganese dioxide cell

The gel electrolyte for the zinc-air cell was prepared by mixing hydroponics gel with a 6M potassium hydroxide aqueous solution. The self-discharge of cells was characterized by measuring the open-circuit voltage. The effect of a discharge rate of 50mA constant current on cell voltage and plateau hour, as well as the voltage-current and current density-power density were measured and analysed. The electrode degradation after discharge cycling was characterized by structural and surface methods. The oxidation of the electrode surface further blocked the utilization of the Zn anode and was identified as a cause for the failure of the cell. (author)

2006-09-13

276

Lead oxides-lithium cells

A rechargeable cell is disclosed which is characterized in the following manner. A positive electrode is formed from a manganese oxide electrode material. This manganese oxide electrode material contains a heavy metal selected from the group comprising lead, bismuth, and mixtures of lead and bismuth. The cell also contains a negative electrode of zinc. A separator is provided between the positive electrode and the negative electrode. An alkaline electrolyte consisting essentially of an alcohol and an alkaline hydroxide is also contained in the rechargeable cell in contact with both the positive electrode and the negative electrode.

1984-05-29

277

Full potential linearized augmented plane wave calculations of structural and electronic properties of GeC, SnC and GeSn

The possibility of using lead and lead-bismuth mixed oxides as positive active materials in organic electrolyte lithium cells with a working voltage similar to those of silver zinc cells has been considered. Button cells of SR 44 size have been developed as a test vehicle and studied under various conditions of discharge rate and storage. This paper describes the performance characteristics obtained under these conditions and suggests in conclusion the possible replacement of silver zinc cells by such systems for a large range of low-rate applications on the basis of cost effectiveness.

1979-01-01

278

Evaluation of carbon substrates for bifunctional air electrodes applied in zinc-air-batteries

A theoretical study of structural and electronic properties of GeC, SnC and GeSn is presented using the full potential linearized augmented plane wave method. In this approach, the generalized gradient approximation was used for the exchange-correlation potential. Results are given for lattice constant, bulk modulus and its pressure derivative in both zinc-blende and rocksalt structures. Band structure, density of states and band gap pressure coefficients in zinc-blende structure are also given. The results are compared with previous calculations and with experimental measurements.

2003-08-01

279

Effect of Carbon Dioxide in the Air on Zinc-air Cell

The key component for improving the energy efficiency and cycle life of the electrically rechargeable zinc-air battery is the bifunctional air electrode. The air electrodes described in this paper contained different types of carbon black as the substrate for the perovskite catalyst (La{sub 0.6}Ca{sub 0.4}CoO{sub 3}). Morphological and physical properties of the carbon substrates play an important role in enhancing the activity and stability of the bifunctional air electrode. Current-potential curves and cycle-life tests were applied in order to gather information on the activity and stability of these electrodes. (authors)

2000-07-01

280

Driving-cycle testing for the PSI zinc/air battery

The electrolyte was brought into contact with air and potassium carbonate was measured with various contact time in order to check the defect of carbon dioxide in the air on zinc-air cell. The relationship between potassium carbonate concentration in electrolyte and battery capacity was also studied. The potassium carbonate concentration in the electrolyte. The rate of carbon dioxide absorption was mainly affected by the pore size of hydrophobic membrane. Our study showed that adapting the pore of hydrophobic membrane decreased the loss of cell discharge performance due to the presence of carbon dioxide or water vapor in the atmosphere. 7 refs., 12 figs., 1 tab.

1999-04-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

281

Biosorption process for removing heavy metal ions using water milfoil (Myriophyllum Spicatum) in contaminated water

This contribution describes our research and development effort towards an electrically rechargeable zinc/air battery which is capable of meeting the demands of a scaled power profile (driving-cycle tests). The power profiles DST (Dynamic Stress Test) and ECE15-L (European Driving Cycle for alkaline Batteries) were applied to our 200 and 50 cm{sup 2} electrically rechargeable Zn/O{sub 2} cells with nominal capacities of 30 and 7.5 Ah, respectively. (authors)

2000-07-01

282

Atmospheric corrosion in Gran Canaria specifically meteorological and pollution conditions

A small scale biomass metal contacting experiment was performed to screen the optimal plant species for biosorption and bioaccumulation of cadmium, zinc, nickel, lead, and copper. Experiments were also conducted to test the ability of the biomass to lower the metal concentrations below the US Environmental Protection Agency surface water discharge criteria. The minimum residual concentration was 0.1 mg/L for zinc, 0.004 mg/L for lead, and about 0.01 mg/L for cadmium, nickel, and lead. Results indicate that water milfoil can be used for bioremoval of metals.

1995-12-31

283

In situ spectroscopic and corrosion studies of ultra-thin gradient plasma polymer layers on zinc

Carbon steel, copper, zinc and aluminium samples were exposed in different sizes with known ambient parameters in Gran Canaria Island and atmospheric corrosion was investigated. Weight-loss measurements used to determine corrosion damage were complemented with metallographic and XP S determination in order to characterize the structure and morphology of surface corrosion products. The ambient aggressiveness could be well evaluated from meteorological and pollution data. All atmospheric corrosion and environmental data were statistically processed for establishing general corrosion damage functions for carbon steel, copper, aluminium and zinc in terms of Gran Canaria extreme meteorological and pollution parameters. (Author)

1998-12-31

284

Studies of the behaviour of technical chemicals introduced into the subsoil under modelled conditions

By means of an audio frequency plasma polymerisation ultra-thin gradient plasma polymer layers were deposited on zinc and zinc-coated iron. The aim was to generate an interfacial polymeric layer which bonds to an oxidised metal as well as to a subsequently applied organic coating and acts as an interfacial barrier layer for ions and water. Surface modifications were done in an in situ plasma cell with infrared reflection absorption spectroscopy (IRRAS). The zinc surface was first activated by an oxygen plasma to provide a freshly oxidised and contamination free oxide surface. The intermediate stages of the surface reactions could be revealed. Carbon dioxide molecules as oxidation products adsorbed on the growing zinc oxide and were desorbed at a later stage. An organosilicon plasma polymer was deposited directly on top of the oxide layer from a hexamethyldisilane (HMDS) plasma. Afterwards a cyclohexene ...

2003-07-15

285

Mine waste disposal and managements

Because of the environmental hazard of organic solvents such as chlorinated or aromatic hydrocarbons, water soluble and biodegradable substitutes have come into use. It should be assessed how they affect soil and aquifer when spilled in leaks or accidents. This was simulated in a model system using methanol and percolation columns, one filled with material from the unsaturated subsurface and two with different materials from aquifers. The results reveal that a spill of the substitutes can also cause problems. In homogeneous soils and at long retention times until the substance reaches the aquifer, sorption and biological degradation are most likely to prevent contamination of the groundwater. When oxygen supply in the subsurface is insufficient, reducing conditions occur and sulphide is formed. The data show that much more methanol was eliminated than reflected by the consumption of electron acceptors. This indicates that sorption and anabolic turnover of the ...

1993-04-01

286

Design, manufacturing, installation, protection of 345 kV 750 MVA submarine power cables in New York

Acid Rock Drainage (ARD) is the product formed by the atmospheric oxidation of the relatively common pyrite and pyrrhotite. Waste rock dumps and tailings containing sulfide mineral have been reported at toxic materials producing ARD. Mining in sulphide bearing rock is one of activity which may lead to generation and release of ARD. ARD has had some major detrimental affects on mining areas. The purpose of this study was carried out to develop disposal method for preventing contamination of water and soil environment by waste rocks dump and tailings, which could discharge the acid drainage with high level of metals. Scope of this study was as following: environmental impacts by mine wastes, geochemical characteristics such as metal speciation, acid potential and paste pH of mine wastes, interpretation of occurrence of ARD underneath tailings impoundment, analysis of slope stability of tailings dam etc. The following procedures were used as part of ARD evaluation and ...

1998-12-01

287

Corrosion behavior of materials at high temperature by environmental oxidants containing sulfur derivatives: effects of aggressive phase composition on experimental alloys. Final report

This paper describes the criteria used for the thermal, electrical, mechanical, hydraulical design of the submarine power cables crossing Long Island Sound to feed New York City. The cables are of the self contained fluid filled (SCFF) type. There is also a description of the special measures adopted to face the exceptionally aggressive environment, due to presence of hydrogen sulphide and of stray currents (caused by electric railways and pipes cathodic protection). The most significant example of such measures is a third sacrificial armour. Four single-core SCFF cables (one spare) were manufactured in Arco Felice (near Naples, Italy), for the New York Power Authority. The average length of the cables is 13 km, jontless. The Italian cable ship 'Giulio Verne', managed by Pirelli, was utilized for the transportation and laying. The ship is equipped with a turntable of 7000 tonnes capacity. The cables are protected all along the route with a total ...

1992-04-01

288

Characterization of atmospheric emissions produced by live gun firing : test on the M777 155 mm Howitzer

For a better understanding of sulphidation mechanisms, some alloys (alloy 600, alloy 800, Uranus S, iron-chromium-aluminium-alloy) and metals (iron, chromium, nickel, molybdenum, titanium) were tested at 773, 873, 1 073 K in gaseous sulphur dioxide. Total pressure was 760 torrs. Sulphur dioxide pressure was 760, 100 and 10 torrs. Argon, oxygen, water vapor were used, successively, as pressure complement. Oxygen supply, generally speaking cause decay of corrosion resistance in SO/sub 2/ atmospheres especially at 1 073 K with low ratio p/sub O2//P/sub SO/sub 2//. Water vapor supply act similarly. Temperature laws and pressure laws do not give monotonous rise of corrosion values. There are maximas suggesting corrosion products undertaking a volatilization process. According to test conditions, Uranus S, chromium, alloy 800 (and titanium at some extent) showed good corrosion resistance. That results are supporting those obtained by JRC Ispra team, working with ...

1981-01-01

289

Air pollutants emissions from waste treatment and disposal facilities.

This study analyzed the atmospheric emissions produced by the live firing of a 155 mm Howitzer gun. The study was conducted during a live firing training exercise at a Canadian Forces Base. Air emissions were sampled continuously for 3 hours. Particles and chemicals were accumulated on sampling media during the firing of 69 rounds. A single round was fired using 4 bags of propellants, and an additional 3 rounds were fired using 5 bags of propellant. Samples included particulate matter; hydrogen cyanide; polycyclic aromatic hydrocarbons (PAHs); dinitrotoluene compounds; benzene; toluene; ethylbenzene; xylene; metals; aldehydes; nitric acid; nitric oxide; nitrogen dioxide; hydrogen sulphide; and sulphur dioxide. Samples were collected at 8 m to the left of the gun as well as at 22 m in front of the gun muzzle in the line of fire. Results of the study showed that 60 per cent of the particles were below 10 {mu}m. Formaldehyde concentrations of 7.1 and 3.6 {mu}g/m{sup ...

2007-10-15

290

Responses of aquatic organisms to metal pollution in a lowland river in Flanders: A comparison of diatoms and macroinvertebrates

This study examined the atmospheric pollution created by some waste treatment and disposal facilities in the State of Kuwait. Air monitoring was conducted in a municipal wastewater treatment plant, an industrial wastewater treatment plant established in a petroleum refinery, and at a landfill site used for disposal of solid wastes. Such plants were selected as models for waste treatment and disposal facilities in the Arabian Gulf region and elsewhere. Air measurements were made over a period of 6 months and included levels of gaseous emissions as well as concentrations of volatile organic compounds (VOCs). Samples of gas and bioaerosols were collected from ambient air surrounding the treatment facilities. The results obtained from this study have indicated the presence of VOCs and other gaseous pollutants such as methane, ammonia, and hydrogen sulphide in air surrounding the waste treatment and disposal facilities. In some cases the levels exceeded the ...

2006-01-01

291

Preparation of ZnO-Al2O3 Particles in a Premixed Flame

The role of macroinvertebrates and diatoms as indicator for metal pollution was investigated by assessing both biota along a metal gradient in the Belgian river the Dommel. Macroinvertebrates and diatoms were sampled in summer and winter and physical-chemical characteristics of the water were measured at four different sample periods and related to sediment characteristics. Although metal concentrations, except cadmium, in the water nowhere exceeded water quality standards, high metal concentrations were measured in the sediment, indicating historical contamination of the Dommel. At the sites that were situated downstream of the pollution source, high levels of conductivity and chloride were measured in the water. Redundancy Analysis (RDA) indicated pH, phosphate and zinc as the significant environmental variables explaining each respectively 7.7%, 11.6% and 22.6% of the macroinvertebrate community composition. Two clusters could be separated, with Gammarus pulex, ...

2008-12-15

292

DEFF Research Database (Denmark)

Zinc oxide (ZnO) and alumina (Al2O3) particles are synthesized by the combustion of their volatilized acetylacetonate precursors in a premixed air-methane flame reactor. The particles are characterized by XRD, transmission electron microscopy, scanning mobility particle sizing and by measurement of the BET specific surface area. Pure (?-)alumina particles appear as dendritic aggregates with average mobile diameter 43-93 nm consisting of partly sintered, crystalline primary particles with diameter 7.1-8.8 nm and specific surface area 184-229 m2/g. Pure zinc oxide yields compact, crystalline particles with diameter 25-40 nm and specific surface area 27-43 m2/g. The crystallite size for both oxides, estimated from the XRD line broadening, is comparable to or slightly smaller than the primary particle diameter. The specific surface area increases and the primary particle size decreases with a decreasing flame temperature and a decreasing precursor ...

2000-01-01

293

Preliminary study on zinc-air battery using zinc regeneration electrolysis with propanol oxidation as a counter electrode reaction

Powering future vehicles with the refuelable zinc/air battery

A zinc-air battery using zinc regeneration electrolysis with propanol oxidation as a counter electrode reaction is reported in this paper. It possesses functions of both zincate reduction and electrochemical preparation, showing the potential for increasing the electronic energy utilization. Charge/discharge tests and scanning electron microscopy (SEM) micrographs reveal that when a nickel sheet plated with the high-H{sub 2}-overpotential metal, cadmium, was used as the negative substrate electrode, the dendritic formation and hydrogen evolution are suppressed effectively, and granular zinc deposits become larger but relatively dense with the increase of charge time. The performance of batteries is favorable even if the charge time is as long as 5 h at the current density of 20 mA cm{sup -2}. Better discharge performance is achieved using a 'cavity-opening' configuration for the discharge cell rather than ...

2009-03-01

294

Contaminant assimilation in newly created prairie wetlands

A recent road test at LLNL underscored the zinc/air battery`s capacity to give electric vehicles some of the attractive features of gas-driven cars: a 400-km range between refueling, 10-minute refueling, and highway-safe acceleration. Developed at Lawrence Livermore National Laboratory, the battery weights only one-sixth as much as standard lead/acid batteries and occupies one-third the space, yet costs less per mile to operate. What`s more, because the battery is easily refuelable, it promises trouble-free, nearly 24-hour-a-day operation for numerous kinds of electric vehicles, from forklifts to delivery vans and possibly, one day, personal automobiles. The test of a Santa Barbara Municipal Transit bus with a hybrid of zinc/air and lead/acid batteries capped a short development period for the zinc/air battery. The test run indicated the zinc/air battery`s potential savings in vehicle weight from 5.7 to ...

1995-10-01

295

Studies on the development of mossy zinc electrodeposits from flowing alkaline electrolytes

Increased use of wetlands for habitat and water quality improvement emphasize the need for further study of abiotic-biotic interactions in these systems. This research examined contaminant assimilation within the water column of two newly created Colorado prairie wetlands (RMA3 and RMA4). To examine the influence of abiotic factors (e.g., alkalinity, suspended solids), ten chronic toxicity tests were performed from December 1991 through November 1993. In the first set of tests, Ceriodaphnia dubia were exposed to water from the two wetlands which was spiked with various concentrations of zinc. These tests suggested that water from RMA4 had higher contaminant assimilative capacity than water from RMA3. Preliminary analysis suggested suspended solids, pH, conductivity, and temperature were important factors affecting neonate production by C. dubia when exposed to zinc-spiked wetland water. To test the importance of suspended solids in contaminant ...

1994-12-31

296

Solar thermal production of zinc: Program strategy

The initiation and characteristics of mossy zinc electrodeposits have been investigated. Batteries with zinc electrodes are candidates for electric vehicle applications; however, this electrode is prone to form non-compact deposits that contribute to capacity loss and battery failure. Moss is deposited when the current density is far from the limiting current. This morphology first appears only after the bulk deposit is approximately 1 {mu}m thick. In this investigation, the effects of flow rate (Re=0--4000), current density (0--50 mA/cm{sup 2}), concentration of the electroactive species (0.25 and 0.5 M), and the concentration of supporting electrolyte (3, 6, and 12 M) on the initiation of moss were examined. The rotating concentric cylinder electrode was employed for most of the experiments; and a flow channel was used to study the development of morphology. After the experiment, the deposit was characterized using microscopic, x-ray ...

1991-07-01

297

Photocatalytic self-cleaning properties of cellulosic fibers modified by nano-sized zinc oxide

The solar thermal production of zinc is considered for the conversion of solar energy into storable and transportable chemical fuels. The ultimate objective is to develop a technically and economically viable technology that can produce solar zinc. The program strategy for achieving such a goal involves research on two paths: a direct path via the solar thermal splitting of ZnO in the absence of fossil fuels, and an indirect path via the solar carbothermal/CH{sub 4}-thermal reduction of Zn O, with fossil fuels (coke or natural gas) as chemical reducing agents. Both paths make use of concentrated solar energy for high-temperature process heat. The direct path brings us to the complete substitution of fossil fuels with solar fuels for a sustainable energy supply system. The indirect path creates a link between today`s fossil-fuel-based technology and tomorrow`s solar chemical technology and builds bridges between present and future energy ...

1999-08-01

298

Noninvasive analysis of skin iron and zinc levels in beta-thalassemia major and intermedia

Nano-sized zinc oxide was synthesized and deposited onto cellulosic fibers using the sol-gel process at ambient temperature. The prepared materials were characterized using several techniques including scanning electron microscopy, transmission electron microscopy, diffuse reflectance spectroscopy, X-ray diffraction and thermogravimetric analysis. X-ray diffraction studies of the ZnO-coated fiber indicate formation of the hexagonal crystal phase which was satisfactory crystallized on the fiber surface. The electron micrographs show formation of zinc oxide nanoparticles within 10-15 nm in size which have been homogeneously dispersed on the fiber surface. The prepared materials show significant photocatalytic self-cleaning activity, which was monitored by diffuse reflectance spectroscopy. The photoactivity was studied upon measuring the photodegradation of methylene blue and eosin yellowish under UV-Vis irradiation. The photocatalytic activity of ...

2011-03-31

299

Isotope - aided studies of the bioavailability of iron and zinc from human diets consumed in Poland

Diagnostic x-ray spectrometry, a method based on x-ray fluorescence analysis, was used for noninvasive determination of iron and zinc in two distinct skin areas, representing predominantly dermal and epidermal tissues, in 56 patients with beta-thalassemia major and intermedia. The mean iron levels in the skin of patients with beta-thalassemia major and intermedia were elevated by greater than 200% and greater than 50%, respectively, compared with control values. The zinc levels of both skin areas examined were within the normal range. The data indicate that the rate and number of blood transfusions, which correlated well with serum ferritin levels (r . 0.8), are not the only factors that determine the amount of iron deposition in the skin (r less than 0.6). Other sources of iron intake contribute to the total iron load in the tissues, particularly in patients who are not given multiple transfusions. The noninvasive quantitation of skin levels ...

1985-01-01

300

Extraction of copper-, nickel-, zinc- and cadmium complexes with 4-(2-pyridilazo)-resorcin and 2-aminopyridine

The main aims of the study were: 1) the evaluation of iron and zinc status in women of Lodz aged 18-45 years, 2) adaptation of the whole body counter to in vivo measurements absorption of iron given to the gastro-intestinal tract of volunteers and 3) in rat model estimation iron bioavailability from fortified wheat flour combined with products usually consumed in Poland. During five months investigations thirty seven women were examined each one twice in two months interval. Following variables were measured: iron and zinc in blood serum, in public and scalp hair and in food, taste acuity score, serum ferritin, hemoglobin, total iron binding capacity, red blood cells, mean corpuscular concentration and corpuscular volume. Prevalence of iron deficiency and iron deficient anemia were assessed by two models in terms of the depression of serum ferritin and hemoglobin concentrations. 64 refs, 6 figs, 23 tabs.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

301

Economic evaluation of the solar thermal co-production of zinc, synthesis gas, and hydrogen

Extraction of copper-, nickel-, zinc- and cadmium complexes with 4-(2 pyridilazo)-resorcin (PAR) is studied in the presence of 2-aminopyridine (Am). Maximum optical densities of the extracts are attained at pH=7.5-8.0; 6.0-7.0; 6.5-7.0 and 7.0-8.0, respectively. The ratio of components in the complexes extractable by chloroform was defined by the method of isomolar series and equilibrium shift. It is established that nickel and copper are extracted to the organic phase as the NiAm(PAR)_2 and CuAmPAR complexes, and, in the case of zinc and cadmium, complexes of different composition are extracted, for example Zn(Am)_2PAR and ZnAm(PAR)_2. The light absorption spectra are studied and molar extinction coefficients of complex extracts are determined at lambdasub(max). It is shown that the general low of light absorption is observed within a sufficiently wide range of concentrations for all the elements.

1984-01-01

302

Coaxial nanocables of p-type zinc telluride nanowires sheathed with silicon oxide: synthesis, characterization and properties

The use of concentrated solar energy for co-producing Zn and synthesis gas from Zn O and natural gas upgrades the calorific value of the initial reactants by 39% and, when compared to the traditional carbothermic reduction of Zn O, has the potential of reducing CO{sub 2} emissions by up to 78%. An economic assessment for an industrial thermochemical plant, 30 to 51 MW solar input, indicates that the cost of solar production of zinc ranges between 89-133 $/t (excluding the cost of Zn O feed and credit for pollution abatement), and thus might be competitive with conventional fossil-fuel-based processes at current fuel prices. The cost of solar H{sub 2}, produced by splitting water with zinc, is estimated to be in the range 0.10-0.14 $/kWh, and it is a favorable long term prospect once the cost of energy will account for the environmental externalities from fossil fuel burning such as the costs for CO{sub 2} mitigation and pollution abatement. ...

1999-08-01

303

The elevation of blood levels of zinc protoporphyrin in mice following whole body irradiation

Coaxial nanocables with a single-crystalline zinc telluride (ZnTe) nanowire core and an amorphous silicon oxide (SiO_x) shell have been synthesized via a simple one-step chemical vapor deposition (CVD) method on gold-decorated silicon substrates. The single-crystal ZnTe nanowire core is in zinc-blende structure along the [111] direction, while the uniform SiO_x shell fully covers the core with no observable pin-hole or crack. Formation mechanisms of the ZnTe-SiO_x nanocables are discussed. The ZnTe nanowire core shows p-type electrical properties while the SiO_x shell acts as an effective insulating layer. The ZnTe-SiO_x nanocables may have potential applications in nanoscale devices, such as p-type FETs and nanosensors.

2009-11-11

304

Sustainable development at Canadian Electrolytic Zinc -- recent improvements

Elevation of zinc protoporphyrin (ZPP) levels in the blood has served as an indicator of lead poisoning and iron deficiency anemia for many years. We have discovered that sublethal doses of whole body irradiation with x-rays also elevates ZPP 2-3-fold over normal levels. The ZPP level does not begin to increase until days 12-14 postirradiation and peaks between days 18 and 20 before returning to normal levels between days 28 and 35. Increasing the radiation dose delays the onset of the rise in ZPP, but does not affect the magnitude of the elevation. At lethal doses, ZPP elevation is not observed. Neither of the two previously described mechanisms that cause elevations of ZPP, namely iron deficiency and inhibition of ferrochelatase, are responsible for the radiation-induced elevation of ZPP. The elevation of ZPP appears to be correlated with the recovery of the hematopoietic system from radiation injury.

1984-05-01

305

Study of interaction between 7-(6-Br-2-benzthiazolylazo)-8-oxiquinoline-5-sulfonic acid and uranium (6), zinc (2) and manganese (2)

A series of modifications which increased the capacity of Canadian Electrolytic Zinc's Valleyfield plant from 220,000 MT/year to 260,000 MT/year during the last decade is discussed, combined with an an overview of the plant's operations. The modifications included modernisation of the waste disposal methods and facilities, such as a new high-density sludge wastewater treatment process, a new process to remove selenium from weak acid solutions and the jarofix process. Roasting capacity also has been improved by recent investments in new cooling coils, rebricking, oxygen enrichment and process automation. In addition to increases in refining capacity, the improvements also enabled the company to minimize its impact on the environment and the community.

2001-07-01

306

Structural, optical, photocatalytic and antibacterial activity of zinc oxide and manganese doped zinc oxide nanoparticles

A new reagent 7-(6-Br-2-henzthiazolilazo)-8-oxyquinoline-5-sulphoacid has been studied spectrophotometrically. Dissociation constants have been determined in 50% acetone (pK_1=2.5 and pK_2=5.9) and 50% dioxane (pK_1=1.7 and pK_2=6.1) as well as molar extinction coefficients of the reagent dissociated form in the same solvents (71.1.10"3 and 72.4.10"3). The conditions have been studied of complexing the reagent with ions of uranium (6), zinc (2), and manganese (2) in 50% dioxane (pH 2.5-4.5) and the properties of the formed complexes.

1977-01-01

307

British Library Electronic Table of Contents (United Kingdom)

Polycrystalline ZnO doped with Mn (5 and 10at%) was prepared by the co-precipitation method. The effect of Mn doping on the photocatalytic, antibacterial activities and the influence of doping concentration on structural, optical properties of nanoparticles were studied. Structural and optical properties of the particles elucidated that the Mn2+ ions have substituted the Zn2+ ions without changing the Wurtzite structure of ZnO. The optical spectra showed a blue shift in the absorbance spectrum with increasing dopant concentration. The photocatalytic activities of ZnO powders were evaluated by measuring the degradation of methylene blue (MB) in water under the UV region. It was found that undoped ZnO bleaches MB much faster than manganese doped ZnO upon its exposure to the U...

2010-01-01

308

Restauration of the Clinton site; Restauration du site Clinton

Production of {sup 62}Zn, {sup 65}Zn and {sup 203}Pb radioisotopes for studying the transport of zinc and lead in plants

Mining of copper and zinc took place at the Clinton Mine located in the Estrie region of Quebec between 1973 and 1975, during which time 115,000 tons of mineral were treated at the Solbec plant. In this poster presentation, the authors provided the background information pertaining to this mine and described the state in which it was in 1994. The pit was covered with good quality water, with a pH of 7,1 and copper and zinc content ranging between 0,1 and 0,6 mg/l, and iron ranging between 0,2 and 1,8 mg/l. The tailings basin drainage was found to have a pH of between 3,6 and 6,1. A program for the characterization of the site was implemented and the concept for the restauration of the Clinton site was developed and implemented. The work carried out at the site is discussed during this presentation as well as the monitoring taking place. 27 figs.

2000-07-01

309

Production of "6"2Zn, "6"5Zn and "2"0"3Pb radioisotopes for studying the transport of zinc and lead in plants

In the Carpathian Basin, significant percentage of watershed area and floodplains of rivers are utilised agriculturally. Several potential sources of poisonous metal pollution have been identified in these areas. Because of spills from some of them a few severe accidents have happened especially in the watershed area of Tisza River during the last decades. The motivation of our present work was to produce {sup 62,65}Zn and {sup 203}Pb radioisotopes because they can be used especially as tracers for studying the kinetics of uptake, transport and accumulation of zinc and lead by plants under different circumstances. (orig.)

2004-07-01

310

Oxygen reduction reaction on electrodeposited zinc oxide electrodes in KCl solution at 70 deg. C

In the Carpathian Basin, significant percentage of watershed area and floodplains of rivers are utilised agriculturally. Several potential sources of poisonous metal pollution have been identified in these areas. Because of spills from some of them a few severe accidents have happened especially in the watershed area of Tisza River during the last decades. The motivation of our present work was to produce "6"2","6"5Zn and "2"0"3Pb radioisotopes because they can be used especially as tracers for studying the kinetics of uptake, transport and accumulation of zinc and lead by plants under different circumstances. (orig.)

311

Lipid-soluble metal compounds in a coal gasifier process stream

The reduction of oxygen was studied in 0.1 M KCl at 70 deg. C using the rotating disk electrode (RDE) technique on platinum and electrodeposited ZnO thin film electrodes deposited on platinum substrates. In the absence of Zn{sup 2+} ions in solution, a Tafel slope of 139 mV dec{sup -1} was obtained, a value close to that measured on bare platinum electrode (133 mV dec{sup -1}) and ascribed to the limitation of the reaction rate by the first electron transfer. The main difference between the noble metal and the oxide electrode was a shift of the curves towards more negative potentials. In the presence of Zn{sup 2+} ions, the current density decreased significantly and the Tafel slope was measured at 282 mV dec{sup -1} showing that the electrode was partially blocked by zinc oxide formation reaction intermediates.

2006-04-01

312

Leaching of zinc sulfide by Thiobacillus ferrooxidans: Bacterial oxidation of the sulfur product layer increases the rate of zinc sulfide dissolution at high concentrations of ferrous ions

The concentrations of iron, chromium, zinc, and aluminum were measured by atomic absorption spectroscopy in the lipid-soluble fractions of tar from the process stream of an experimental coal gasifier as part of large study on the health risks of coal gasification. Lipid solubility was inferred from octanol/water-partitioning and benzene-solubility tests. The properties of the lipid-soluble metals were compared to reference compounds by Sephadex LH-20 chromatography. The ability of the lipid-soluble metals to remain lipid soluble after treatment with acid and base was also tested. Lipid-soluble iron, chromium, zinc, and aluminum were present at 360, 12, 3, and 1 ppM, respectively, in the gasifier coal tar. The presence of these metals in lipid-soluble form may have important consequences relative to the potential toxicity of the tar if persons are exposed to it.

1982-08-01

313

Full size zinc-air battery

This paper reports the results of leaching experiments conducted with and without Thiobacillus ferroxidans at the same conditions in solution. The extent of leaching of ZnS with Bacteria is significantly higher than that without bacteria at high concentrations of ferrous ions. A porous layer of elemental sulfur is present on the surfaces of the chemically leached particles, which no sulfur is present on the surfaces of the bacterially leached particles. The analysis of the data using the shrinking-core model shows that the chemical leaching of ZnS is limited by the diffusion of ferrous ions through the sulfur product layer at high concentrations of ferrous ions. The analysis of the data shows that diffusion through the product layer does not limit the rate of dissolution when bacteria are present. This suggests that the action of T.ferroxidans in oxidizing the sulfur formed on the particle surface is to remove the barrier to diffusion by ferrous ions.

1999-12-01

314

Full potential linearized augmented plane wave calculations of positronic and electronic charge densities of zinc-blende AlN, InN and their alloy Al_0_._5In_0_._5N

The Electric Fuel zinc-air battery yielded energy densities from 6.8 to 10.2 times higher than those of the lead-acid batteries. The higher the power and the more difficult the driving cycle, the higher this ratio of energy densities grew. Not only was the Electric Fuel battery capable of extended high-power discharge, the impact of such discharge conditions on energy and driving range was show to be quite small, and was much smaller than the comparable impact on lead-acid traction batteries. At the time of writing this paper, tests are scheduled to continue with the 110-kWh battery in the Mercedes van, and preliminary plans have been made for testing of additional batteries on other vehicle types.

1993-11-01

315

Determination of some minor and trace elements in iron ores by ion exchange chromatography, spectrophotometry and atomic absorption spectrometry

A theoretical study of electron and positron band structures of zinc-blende AlN and InN and their alloy Al_0_._5In_0_._5N is presented using the first-principles full-potential linearized augmented plane-wave method. Equilibrium lattices constants are determined from the total-energy minimization method. The results are compared with previous calculations and with experimental measurement. Electron and positron charge densities are computed as function of position in the unit cell. Detailed plots of distributions are along the direction. The ionicity factors are calculated by means of three different approaches. The calculated results of the positron charge density reflect the high insight for the annihilation effect.

2005-06-01

316

Demonstration of zinc/air fuel battery to enhance the range and mission of fleet electric vehicles: Preliminary results in the refueling of a multicell module

A method is described for determination of aluminium, cadmium, cobalt, chromium, copper, calcium, magnesium, sodium, potassium, manganese, nickel, lead, strontium, zinc, titanium and vanadium in iron ore. After dissolution, a 1 gram sample of iron ore is applied to a column of AGI-X8 anion exchange resin (chloride form), in 100 ml of 7M HCl. Aluminium, chromium, calcium, magnesium, sodium, potassium, manganese, nickel, lead, strontium, titanium and vanadium are eluted with 7M HCl; iron, copper and cobalt are eluted with 0.5M HCl; cadmium and zinc are eluted with 2M HNO_3. Iron is subsequently removed from copper and cobalt by a solvent extraction with methyl isobutyl ketone. The elements are determined in the eluates by atomic absorption spectrometry, except for titanium and vanadium, which are determined spectrophotometrically.

317

Core testing of zinc/air refuelable battery modules

We report progress in an effort to develop and demonstrate a refuelable zinc/air battery for fleet electric vehicle applications. A refuelable module consisting of twelve bipolar cells with internal flow system has been refueled at rates of nearly 4 cells per minute refueling time of 10 minutes for a 15 kW, 55 kWh battery. The module is refueled by entrainment of 0.5-mm particles in rapidly flowing electrolyte, which delivers the particles into hoppers above each cell in a parallel-flow hydraulic circuit. The concept of user-recovery is presented as an alternative to centralized service infrastructure during market entry.

1994-08-08

318

Co-ordinated research programme on isotope-aided studies of the bioavailability of iron and zinc from human diets. Report of the second research co-ordination meeting, Hyderabad, India, 16-20 November 1992

We are developing a refuelable zinc/air battery (6-cells) for evaluation under the five USABC `core` test protocols. In the first half of the two year project ($1OOK, FY1997), an advanced refuelable design was developed, fabricated and tested at power levels up to 415 W. Performance matched or exceeded that of earlier multicell systems. A computer program was developed for automated data acquisition and drive cycle simulation. Small mockup cells (80 cm 2) were constructed for rapid testing of components. In the follow-on effort (FY1998, $1OOK) we will make minor advances in system design and fabrication efficiency, and seek to improve cathode performance and life, before delivery of two final units for test at DOE laboratory.

1998-08-20

319

Biosorption of Zn(II) by Thiobacillus ferrooxidans

The Co-ordinated Research Programme (CRP) on ''Isotope-Aided Studies on the Bioavailability of Iron and Zinc from Human Diets'' was initiated by the IAEA in 1990, and presently encompasses participating institutes in 11 countries. A summary of the discussions that took place during thr second Research Co-ordination Meeting held in Hyderabad, India, between 16-20 November 1992, is given in this report together with 12 working papers (progress reports) presented by individual participants. A separate abstract was prepared for each of these papers. Refs, figs and tabs.

1992-11-16

320

Ag/C nanoparticles as an cathode catalyst for a zinc-air battery with a flowing alkaline electrolyte

There have been a number of studies considering the possibility of removing and recovering heavy metals from diluted solutions. These are due, principally, because of the commercial value of some metals as well as in the environmental impact caused by them. The traditional methods for removing have several disadvantages when metals are present in concentrations lower than 100 mg/l. Biosorption, which uses biological materials as adsorbents, has been considered as an alternative method. In this work, variables like pH and biomass chemical pretreatment have been studied for its effect on the capacity for zinc biosorption by Thiobacillus ferrooxidans. Also, studies to determinate the time for zinc adsorption were carried out. Results indicate that a capacity as high as 82.61 mg of Zn(II)/g of dry biomass can be obtained at a temperature of 25 C and that the biosorption process occurs in a time of 30 min. (orig.)

2000-06-01

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321

A new zinc hydroxide nitrate heterogeneous catalyst for the esterification of free fatty acids and the transesterification of vegetable oils

The cyclic voltammetry indicated that the oxygen reduction reaction (ORR) proceeded by the four-electron pathway mechanism on larger Ag particles (174 nm), and that the ORR proceeded by the four-electron pathway and the two-electron pathway mechanisms on finer Ag particles (4.1 nm), simultaneously. The kinetics towards ORR was measured at a rotating disk electrode (RDE) with Ag/C electrode. The number of exchanged electrons for the ORR was found to be close to four on larger Ag particles (174 nm) and close to three on finer Ag particles (4.1 nm). The zinc-air battery with Ag/C catalysts (25.9 nm) was fabricated and examined. (author)

2009-09-05

322

British Library Electronic Table of Contents (United Kingdom)

A new heterogeneous catalyst for the esterification of free fatty acids and the transesterification of vegetable oils is reported. The layered compound zinc hydroxide nitrate (Zn5(OH)8(NO3)22H2O) was very effective in the alcoholysis of palm oil and the esterification of lauric acid with m(ethanol), even when hydrated ethanol was used. Over the range of 100-140degreeC, the ester yield was the highest at 140degreeC, while the catalyst concentration had a much greater effect on ester yields than the molar ratio of alcohol to acid did. Total ester contents above 95wt% were obtained in both reactions and 93.2wt% glycerin streams were recovered as a result of methanolysis.

2008-01-01

323

A ZnO nanowire array film with stable highly water-repellent properties

A 1500-year record of lead, copper, arsenic, cadmium, zinc level in Antarctic seal hairs and sediments

Highly water-repellent surfaces have been prepared from arrayed nanowires of zinc oxide (ZnO) by a treatment with stearic acid. The layers are electrochemically deposited on a nanocrystalline seed layer from an oxygenated aqueous zinc chloride solution. An advancing contact angle (CA) as high as 176{sup 0} is obtained with a very small hysteresis {approx}1{sup 0}. These results, supplemented by infrared spectroscopy, show that the stearic acid forms a very well-packed self-assembled monolayer. The CA measurements show a very good stability of the treated surface even when exposed to harsh conditions or long-term ambient illumination.

2007-09-12

324

British Library Electronic Table of Contents (United Kingdom)

To reconstruct the profiles of heavy metal levels in the South Ocean ecosystem of Antarctica, the concentrations of lead (Pb), copper (Cu), arsenic (As), cadmium (Cd), and zinc (Zn) in seal hairs and lake sediments spanning the past 1500?years from Fildes Peninsula of King George Island and in weathering lake sediments from Nelson Island of West Antarctica were determined. The lead contents in the seal hairs and the weathering sediments show a sharp increase since the late 1800s, very likely due to anthropogenic contamination from modern industries. After the 1980s, the Pb content in seal hairs dropped by one-third, apparently due to the reduced usage of leaded gasoline in the Southern Hemisphere. Copper arises mainly from the weathering process, and its level may be substantially affected...

2006-01-01

325

Zn-Al alloy as a new anode-metal of a zinc-air battery

The separation and determination of trace elements in iron ore

Low operating power and short cycle life are 2 of the main draw-backs of zinc-air batteries, despite the fact that various attempts have been made to develop improved zinc (Zn) anodes. This study investigated the performance of a Zn anode with a substantial addition of aluminium (Al). Rolled sheets of Zn-Al alloys of varying amounts of Zn and Al were used to prepare the anodes. Results of the study showed that the cells had higher open circuit voltages (OCV) values as well as a higher specific anode capacity. It was observed that specific anode capacity increased with higher current loading. The Zn{sub 59}Al{sub 41} and Zn{sub 67}Al{sub 33} sheets showed the highest performance with high OCV values of between 1540 and 1560 mV, as well as the largest specific anode capacity of 750-800 mAh per g at a discharge current of 200 mA. The 2-phase structure of the Zn-Al sheets was considered to be useful in reducing anode-passivation, and increasing ...

2006-01-15

326

The postal service wants to move away from diesel transport. Die Post will sich von ihren Dieseltransportern trennen

The separation, concentration, and determination of trace elements in iron ores are described. After the sample has been dissolved, the iron is separated by liquid-liquid extraction with a liquid cation-exchanger, di-(2-ethylhexyl) phosphoric acid. The trace elements aluminium, cadmium, calcium, chromium, cobalt, copper, lead, magnesium, manganese, mercury, potassium, sodium, vanadium, and zinc are determined in the aqueous phase by atomic-absorption spectrophotometry.

2008-05-01

327

The effect of phytic acid on the levels of blood glucose and some enzymes of carbohydrate and lipid metabolism.

By the year 2000, the Postal Service aims to reduce its diesel transport by around 15000 vehicles. The advisory service, Detecon, is reviewing alternatives for postal deliveries as part of the ''Post 2000'' initiative. One such system is an electric-powered vehicle with a zinc-air battery from the Israeli firm Electric Fluid Limited (EFL). (orig.)

1994-01-05

328

The combined transduction of copper, zinc-superoxide dismutase and catalase mediated by cell-penetrating peptide, PEP-1, to protect myocardium from ischemia-reperfusion injury

In this study, six groups of rats were fed as follows: Groups 1 and 2 were fed formulated diets supplemented with zinc or without zinc respectively. Groups 3 and 4 were fed formulated diets supplemented with zinc plus phytic acid extracted from sweet potato (Ipomea batatas) or commercial phytic acid respectively. Groups 5 and 6 were fed formulated diets supplemented with phytic acid extract from sweet potato or commercial phytic acid respectively. The animals were fed for three weeks and then sacrificed The activities of key enzymes of carbohydrate and lipid metabolism as well as transaminases in the liver were determined. Blood glucose level was also assessed. Phytic acid extract consumption from sweet potato and commercial phytic acid plus zinc supplement lowered blood glucose levels. There was no significant change in the activity of 6-phosphogluconate dehydrogenase among the groups. Similarly, ...

2005-03-01

329

Sorption of gold by activated charcoal from cyan-containing solutions of complex salt composition

BackgroundOur previous studies indicate that either PEP-1-superoxide dismutase 1 (SOD1) or PEP-1-catalase (CAT) fusion proteins protects myocardium from ischemia-reperfusion-induced...Full Text Available

330

Positive electrode for an alkaline primary air oxygen battery with thickened electrolyte. Positive Elektrode fuer ein alkalisches primaeres Luftsauerstoffelement mit eingedicktem Elektrolyten

An evaluation was made of the effectiveness of the action of reagents used for cleaning cyan-containing waste water for conditioning of the overflow of copper concentrate thickners of the Belousovskiy enrichment before sorption extraction of gold by activated charcoal. It was established that conditioning of the overflow by iron sulfates (II), copper and zinc diminshes, and by hypochlorite increases the capacitance of the activated charcoal for gold.

1982-01-01

331

Identification of Thlaspi caerulescens Genes That May Be Involved in Heavy Metal Hyperaccumulation and Tolerance. Characterization of a Novel Heavy Metal Transporting ATPase1

A cathode of improved discharge characteristics for a zinc-air battery is prepared from mixtures containing gamma-MnO/sub 2/ 33-67 wt%, C 12-40 wt% and KOH 20-28 wt%.

1981-06-19

332

Final Report: Planetary Instrument Definition and Design Program (PIDDP) Support Project

Thlaspi caerulescens is a heavy metal hyperaccumulator plant species that is able to accumulate extremely high levels of zinc (Zn) and cadmium (Cd) in its shoots (30,000 μg...Full Text Available

2004-11-01

333

Energy storage for hybrid remote power systems

The results of Sandia National Laboratories' participation in the NASA Planetary Definition and Design Program are summarized. Areas reported include the characterization of large area cadmium zinc telluride spectrometers and the application of simulation techniques to the prediction of device performance. Also investigated was the response of mercuric iodide devices in the region from 1 to 100 KeV. A literature study to determine the status or radiation damage measurements in room temperature semiconductor devices is also reported.

1999-03-01

334

Development of zirconium alloys. Part II

Energy storage can be a cost-effective component of hybrid remote power systems. Storage serves the special role of taking advantage of intermittent renewable power sources. Traditionally this role has been played by lead-acid batteries, which have high life-cycle costs and pose special disposal problems. Hydrogen or zinc-air storage technologies can reduce life-cycle costs and environmental impacts. Using projected data for advanced energy storage technologies, LLNL ran an optimization for a hypothetical Arctic community with a reasonable wind resource (average wind speed 8 m/s). These simulations showed the life-cycle annualized cost of the total energy system (electric plus space heating) might be reduced by nearly 40% simply by adding wind power to the diesel system. An additional 20 to 40% of the wind-diesel cost might be saved by adding hydrogen storage or zinc-air fuel cells to the system. Hydrogen produced by electrolysis of water using ...

1998-03-01

335

Cadmium down-regulation of kidney Sp1 binding to mouse SGLT1 and SGLT2 gene promoters: Possible reaction of cadmium with the zinc finger domain of Sp1

A number of alloys of zirconium have been investigated as part of a program aimed at improving the high-temperature tensile and creep strength of zirconium. These alloys include aluminum, beryllium, lead, magnesium, molybdenum, niobium, tantalum, tin, titanium, tungsten, vanadium, and zinc, binary and ternary alloys. The data indicate that aluminum, lead, molybdenum niobium, tin, titanium, tungsten, and vanadium can be used successfully to harden zirconium, and that aluminum, tin, titanium, and vanadium are particularly effective in maintaining the strength of zirconium at elevated temperatures.

1952-01-02

336

A novel zinc-air battery for electric vehicles

Cadmium (Cd) exposure causes glucosuria (glucose in the urine). Previously, it was shown that Cd exposure of primary cultures of mouse kidney cells (PMKC) decreased mRNA levels of the glucose...Full Text Available

2010-05-01

337

Stress corrosion cracking of 13% Cr martensitic steels in sodium chloride solutions in the presence of thiosulphate

A new type of zinc electrode is matched with new bifunctional air electrodes to produce a zinc-air battery of a novel design. The zinc electrode is a flow-thru type made from copper foam-metal. The air electrode uses corrosion resistant carbon black as a high area support for a highly dispersed spinel oxide electrocatalyst. The battery design employs flowing electrolyte, 12 M KOH saturated or supersaturated with zincate. Single cells as large as 200 cm{sup 2} (1/5 EV design scale) having a capacity of 20 AH have been tested with C/4--C/16 constant current cycling. More extensive and realistic life cycle testing was done with 2 Ah cells, including the Simplified Federal Urban Driving Schedule (SFUDS) cycle. This testing has confirmed that these cells can provide the necessary transient power response required for urban EV applications. The cells achieved an average of 72 SFUDS repetitions (7.2 hrs) per discharge cycle, more ...

1995-07-01

338

Sea-to-sky airshed ambient quality monitoring report : 1984-2001

The stress corrosion cracking (SCC) susceptibility of 13% Cr martensitic (UNS S42000) and supermartensitic (UNS S41125) steels in sodium chloride solutions in the presence of thiosulphate was evaluated by slow strain rate tests (SSRT). The tests were performed in 5% sodium chloride solutions buffered at pH 2.7, 3.5, 4.5 and 6.0 in the absence and presence of thiosulphate in a concentration range between 10{sup -6} and 10{sup -3} M, at 25 {+-} 0.1 C. The electrochemical behaviour of the two steels in the different solutions was determined by recording the anodic and cathodic polarisation curves. 13% Cr martensitic steel showed SCC in 5% sodium chloride solutions with pH {<=} 4.5 in the presence of 3 x 10{sup -6} thiosulphate. Decreasing the chloride ion concentration from 50 to 10 g/l, the critical concentration of thiosulphate to provoke SCC susceptibility increased from 3 x 10{sup -6} to 1 x 10{sup -5} M. The resistance to SCC of the supermartensitic steel was higher than that ...

2000-04-01

339

Air quality monitoring Lloydminster area : 2002, 2003 and 2004 seasonal monitoring : final report

This report provides information to government and industry to enable decision-making and management of local environmental quality conditions. The need for a summary air quality report has arisen in recent years due to growing concerns about air quality. Increased growth in population and the tourism industry is placing additional pressures on environmental quality. The report summarized meteorological and air quality data collected by the British Columbia Ministry of Water, Land and Air Protection in the Sea-to-Sky airshed from 1984 to 2001. The airshed is located in the Lower Mainland region of British Columbia. Air quality monitoring was conducted for various periods at 18 different stations and meteorological monitoring was conducted at 4 locations. A list of both provincial and national air quality objectives and standards was provided, with definitions and reference levels from the Canadian Environmental Protection Act. Meteorological data was presented on a station by station ...

2004-09-01

340

Thermal effect on superhydrophobic performance of stearic acid modified ZnO nanotowers

As part of its air quality monitoring activities, Alberta Environment conducts unannounced mobile air quality surveys each year using the Department's Mobile Air Monitoring Laboratory (MAML). This laboratory provides a snapshot of the air quality at the location monitored for a particular time and space. The MAML measures several pollutants in the air including ammonia, carbon monoxide, hydrocarbons, oxides of nitrogen, ozone, particulate matter, reduced sulphur compounds and sulphur dioxide. Alberta Environment conducted a series of ambient air quality monitoring surveys in the Lloydminster Area in 2002, 2003 and 2004. This report presents the results of the five monitored locations over eight seasons of monitoring, which were selected in consultation with stakeholders and staff from Alberta Environment's Central Region office. Canister samples were also collected during these surveys for later laboratory analyses of volatile organic compounds. Results from other ...

2005-11-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

341

Role of the presence of transition-metal atoms at the antisites in CrAs, CrSe and VAs zinc-blende compounds

The thermal desorption of stearic acid on superhydrophobic zinc oxide nanotowers has been investigated. The stearic acid passivated zinc oxide nanotowers provide a very high contact angle of {approx}173 {+-} 1.1 deg. with a very low hysteresis of {approx}1.4 {+-} 0.5 deg. due to the presence of a binary structure composed of several nanosteps on each nanotower of height {approx}700 nm that eventually reduces the area of contact between the drop and the nanotowers and trapping more air as revealed by the field emission scanning electron microscopy images. The superhydrophobic performance of these nanotowers, however, declines following annealing at elevated temperatures. Fourier transform infrared spectra show a reduction in the intensity of stearic acid -CH{sub n} peaks at elevated temperatures revealing the cause of the decrease in contact angle and confirming the occurrence of thermal desorption at 184 deg. C. The corresponding activation ...

2008-02-28

342

Release of zinc from disposable coils during hemodialysis

In a recent publication [I. Galanakis, K. Ozdog-tilde an, E. Sasiog-tilde lu, B. Aktas, Phys. Rev. B 74 (2006) 140408(R)] we have shown that in the case of CrAs and related transition-metal chalcogenides and pnictides, crystallizing in the zinc-blende structure, the excess of the transition-metal atoms leads to half-metallic ferrimagnetism. The latter property is crucial for spintronic applications with respect to ferromagnets due to the lower stray fields created by these materials. We extend this study to cover the case where the transition-metal atoms sitting at antisites are not identical to the ones in the perfect sites. In Cr-based compounds, the creation of Mn antisites keeps the half-metallic ferrimagnetic character produced also by the Cr antisites. In the case of VAs, Cr and Mn antisites keep the half-metallic character of VAs (contrary to V antisites) due to the larger exchange splitting exhibited by these atoms.

2008-02-15

343

Reduction of CO{sub 2} concentration in a zinc/air battery by absorption in a rotating packed bed

In a prior study, we demonstrated that certain disposable coils are contaminated with zinc and release substantial quantities of Zn during hemodialysis, producing high post-dialysis plasma Zn concentrations. The present investigation was designed to monitor plasma and dialysis fluid Zn and copper throughout dialysis and to estimate patient Zn and Cu uptake. Venous plasma, arterial plasma and coil chamber fluid were sampled periodically throughout dialysis; trace metal concentrations were determined by flame atomic absorption spectrophotometry. Release of considerable quantities of Zn from the coils into the dialysis fluid, with uptake into the patient's plasma, was found. Approximately one-half of the plasma Zn uptake occurred in the first 45 minutes. Coils from different lots released significantly different quantities of Zn. Patient uptake of Zn ranged from 3.2 mg-23.0 mg, with a mean of 15.0 +- 6.1 mg. Copper release and uptake was low. It is ...

1981-06-01

344

Properties of ZnO thin films prepared by radio-frequency plasma beam assisted laser ablation

The reduction of CO{sub 2} concentration in a gas stream containing 500ppm of CO{sub 2} by a technique combining chemical absorption with Higee (high gravity) was investigated in this study. Using a 2.0L aqueous amine-based solution to treat the feed gas with a flow rate which varied from 12.9 to 20.6Lmin{sup -1}, piperazine (PZ) was found to be more effective than 2-(2-aminoethylamino) ethanol (AEEA) and monoethanolamine (MEA) for reducing the CO{sub 2} concentration to a level below 20ppm. The effects of temperature, rotating speed, amine solution flow rate, and gas flow rate on the removal efficiency of CO{sub 2} were systematically examined. The results indicated that the proposed compact device could effectively reduce CO{sub 2} to a level below 20ppm, as required by a zinc/air battery, for a long period of time using PZ and its mixture with AEEA and MEA as the absorbents. (author)

2006-11-22

345

Initial stage of localized corrosion in artificial pits formed with photon rupture on Zn-5 mass% Al alloy-coated steel

Zinc oxide thin films were obtained by laser ablation of a Zn target in oxygen reactive atmosphere, the oxygen being supplied either by a standard gas inlet valve or from a radio-frequency (rf) oxygen plasma. Pt-coated silicon and MgO were used as substrates. The influence of the deposition parameters as laser wavelength (266, 355, 1064 nm), laser fluence (1.5-20 J/cm2) and oxygen pressure (1-60 Pa) was studied. The influence of the rf plasma beam addition on the morphological proprieties of zinc oxide films was particularly investigated, simultaneously with several configurations of the direction of the ablation plasma, the rf plasma beam and the substrate. The obtained films, with thicknesses in the range of 50 nm to 1 ?m have been characterized by atomic force microscopy (AFM), X-ray diffraction (XRD), transmission electron microscopy (TEM).

2005-07-15

346

Hydrogen evolution and corrosion performance of NiZn coatings

The photon rupture method, by which oxide film and metal are removed by focused pulsed Nd-YAG laser beam irradiation, was applied to form artificial micro-pits in Zn-5 mass% Al alloy-coated steel. The zinc alloy-coated layer was removed by pulsed laser irradiation treatment for about one second in a neutral buffer solution with NaCl. The rest potential transient with the laser treatment was measured. In the early stage of the laser treatment the rest potential of zinc alloy-coated steel changed to the negative direction immediately after every irradiation of a laser pulse and then returned to the previous value. However, after the steel substrate was exposed to the solution, the rest potential moved to the positive direction immediately after every irradiation of a laser pulse and then returned to the previous value. The amplitude and duration of the potential change after the laser irradiation increased with repetition of laser irradiation, ...

2007-05-01

347

Growth and characterisation of electrodeposited ZnO thin films

The hydrogen evolution reaction (HER) was studied on bare brass (B), nickel coated brass (B/Ni), nickel-zinc alloy coated brass (B/NiZn, leached Zn), nickel (under layer)/nickel-zinc alloy coated (top layer) brass electrodes (B/Ni/NiZn, leached Zn) in 1 M NaOH solution using electrolysis, cathodic polarization and electrochemical impedance spectroscopy (EIS) techniques. Long term tests were performed in order to evaluate the electrocatalytic activity and corrosion performance of the prepared electrodes with operation time. The results showed that leached electrodes, especially B/Ni/NiZn electrode, have a smaller overpotential than the others and a good electrocatalytic activity for the HER. Its electrocatalytic activity is also stable over electrolysis time. Contrary to the HER performance, B/NiZn cannot provide an adequate corrosion protection. However, when a thin Ni layer was coated under the NiZn alloy coating (B/Ni/NiZn), a greater ...

2007-02-01

348

Experimental Evaluation And Simulation Of Multi-pixel Cadmium-zinc-telluride Hard-x-ray Detectors

The electrochemical method has been used to deposit zinc oxide (ZnO) thin films from aqueous zinc nitrate solution at 80 deg. C onto fluorine doped tin oxide (FTO) coated glass substrates. ZnO thin films were grown between - 0.900 and - 1.025 V vs Ag/AgCl as established by voltammogram. Characterisation of ZnO films was carried out for both as-deposited and annealed films in order to study the effect of annealing. Structural analysis of the ZnO films was performed using X-ray diffraction, which showed polycrystalline films of hexagonal phase with (002) preferential orientation. Atomic force microscopy was used to study the surface morphology. Optical studies identified the bandgap to be {approx} 3.20 eV and refractive index to 2.35. The photoelectrochemical cell signal indicated that the films had n-type electrical conductivity and current-voltage measurements showed the glass/FTO/ZnO/Au devices exhibit rectifying properties. The thickness of ...

2008-04-30

349

Electrochemical power generation apparatus and methods

This dissertation describes the evaluation of many-pixel Cadmium-Zinc-Telluride (CdZnTe) hard-X-ray detectors for future use with the High Energy Replicated Optics (HERO) telescope being developed at Marshall Space Flight Center. The detector requirements for the HERO application are good energy resolution (sufficient to resolve cyclotron features and nuclear lines), spatial resolution of ∼200 μm, minimal charge loss of absorbed X rays, and minimal sensitivity to the background environment. This research concentrates on assessing the suitability of these detectors for the focus of HERO, and includes the development of a simulation of the physics involved in an X-ray-detector interaction, a study of the intrinsic material properties, measurements with prototype detectors such as the energy and spatial resolution, charge loss, and X-ray background reduction through 3-dimensional depth sensing. Two types of detectors were available for evaluation. The ...

2004-01-01

350

Electrochemical power generation

Apparatus and methods are described for generating heat and electricity from the consumption of a variety of aluminum products. The method consists of (A) a reaction chamber containing an aqueous electrolyte solution and adapted for introduction therein of aluminum pieces of various shapes and sizes up to a certain maximum predetermined size and for effecting a chemical reaction between said aqueous electrolyte and said aluminum pieces yielding aluminum hydroxide and an intermediate reactant; (B) means for feeding said aluminum pieces into said reaction chamber in small quantities upon demand; (C) means for removing the heat generated in said chamber as a result of said reaction; (D) means for removing said aluminum hydroxide reaction product; and (E) means for oxidizing said intermediate reactant in an electrochemical cell, thereby generating electrical energy. The intermediate reactant is preferably hydrogen or zinc. The latter may be used in a slurry type ...

1981-03-03

351

Elastic properties and structural studies on some zinc-borate glasses derived from ultrasonic, FT-IR and X-ray techniques

Apparatus and methods for generating heat and electricity from the consumption of a variety of aluminum products comprise: (A) a reaction chamber containing an aqueous electrolyte solution and adapted for introduction therein of aluminum pieces of various shapes and sizes up to a certain maximum predetermined size and for effecting a chemical reaction between said aqueous electrolyte and said aluminum pieces yielding aluminum hydroxide and an intermediate reactant; (B) means for feeding said aluminum pieces into said reaction chamber in small quantities upon demand; (C) means for removing the heat generated in said chamber as a result of said reaction; (D) means for removing said aluminum hydroxide reaction product; and (E) means for oxidizing said intermediate reactant in an electrochemical cell, thereby generating electrical energy. The intermediate reactant is preferably hydrogen or zinc. The latter may be used in a slurry type zinc/air ...

1983-01-18

352

Apparent molar volumes and apparent molar heat capacities of aqueous nickel(II) nitrate, copper(II) nitrate, and zinc(II) nitrate at temperatures from (278.15 to 393.15) K at the pressure 0.35 MPa

Glasses in the system (1 - x) [29Na2O- 4Al2O3- 67B2O3]- xZnO (0 ? x ? 35 mol%), have been prepared by the melt quenching technique. Elastic properties, X-ray and FT-IR spectroscopic studies have been employed to study the role of ZnO on the structure of the investigated glass system. Elastic properties and Debye temperature have been investigated using sound wave velocity measurements at 4 MHz at room temperature. The results showed that the density increases and the molar volume decreases while both sound velocities and the determined glass transition temperatures decrease with increase in x. X-ray and infrared spectra of the glasses reveal that the borate network consists of diborate units and is affected by the increase in the concentration of ZnO content. These results are interpreted in terms of the decrease in the N4 values (fraction of tetrahedral coordinated boron atoms), and substitution of longer bond lengths of Zn-O in place of shorter B-O bond. The results indicate that ...

2009-05-05

353

A 1500-year record of lead, copper, arsenic, cadmium, zinc level in Antarctic seal hairs and sediments

Apparent molar volumes V{sub phi} and apparent molar heat capacities C{sub p,phi} were determined for aqueous solutions of nickel(II) nitrate, copper(II) nitrate, and zinc(II) nitrate at molalities m=(0.01 to 0.5) mol {center_dot} kg{sup -1}, and at the pressure p=0.35 MPa. Solution densities obtained using a vibrating-tube densimeter at T=(278.15 to 368.15) K were used to calculate V{sub phi} values. Heat capacity measurements obtained with a twin fixed-cell, differential-output, power-compensating, temperature-scanning calorimeter at T=(278.15 to 393.15) K were used to calculate values of C{sub p,phi}. Our results were then fitted to functions of m and T and compared to literature values.

2004-05-01

354

Trace metals in tap water from Tehran, Iran

To reconstruct the profiles of heavy metal levels in the South Ocean ecosystem of Antarctica, the concentrations of lead (Pb), copper (Cu), arsenic (As), cadmium (Cd), and zinc (Zn) in seal hairs and lake sediments spanning the past 1500 years from Fildes Peninsula of King George Island and in weathering lake sediments from Nelson Island of West Antarctica were determined. The lead contents in the seal hairs and the weathering sediments show a sharp increase since the late 1800s, very likely due to anthropogenic contamination from modern industries. After the 1980s, the Pb content in seal hairs dropped by one-third, apparently due to the reduced usage of leaded gasoline in the Southern Hemisphere. Copper arises mainly from the weathering process, and its level may be substantially affected by climatic conditions. The concentrations of Cd, As, and Zn do not show any clear temporal trends.

2006-12-01

355

The secondary slurry-zinc/air battery

A total of 272 tap water samples were collected from 68 homes throughout the city of Tehran. Analysis for cadmium, zinc, lead, copper, arsenic, iron and manganese showed some accumulation of these metals in household piping overnight. However, the concentration of all metals was in the parts per billion (ug/l) range and well below international standards. Heavy metals in Tehran's drinking water therefore, do not pose a significant acute health hazard. 19 references, 2 tables.

1986-01-01

356

Synthesis and characterization of nickel(II), chromium(III), cobalt(II), copper(II), zinc(II), and cadmium(II) complexes with isatin- isonicotinoylhydrazone

The rechargeability of the slurry-Zn/air battery was demonstrated with a practical recharge cell that requires minimal hydraulic and mechanical energy for operation. A dendritic Zn was deposited on a Mg plate substrate from which it was easily, periodically and automatically scraped to regenerate dendritic Zn slurries. Excellent discharge results were obtained with the regenerated dendritic Zn slurry, comparable to those obtained with slurries made with mixtures of Zn powder. The dendritic Zn slurry allowed, however, twice the utilization of Zn. 13 refs., 24 figs., 2 tabs.

1989-07-01

357

Structural origin of optical bowing in semiconductor alloys p

A few metal complexes of isatin-isonicotinoylhydrazone with Ni(II), Cr(III), Co(II), Cu(II), Zn(II) and Cd(II) have been prepared and characterized on the basis of elemental analyses, infrared and electronic spectra as well as "1H NMR spectra, conductivity and magnetic measurements. In view of the results obtained, it has been found that two molecules of isatin-isonicotinoylhydrazone are chelated to the central metal ion as bis-uninegative ONO tridentate ligand forming non-electrolytic octahedral metal complexes. (author)

1997-03-01

358

Structural origin of optical bowing in semiconductor alloys p

The principle of conservation and transferability of chemical bonds explains the recent discovery by extended x-ray absorption fine-structure measurements of two unequal anion-cation bond lengths R/sub A/C and R/sub B/C in A/sub x/B/sub 1-x/C zinc-blende semiconductor alloys despite the close adherence of the lattice constant to the average value (Vegard rule). This bond alternation, manifested as a structural distortion to a local chalcopyrite coordination around the anions, explains also most of the observed optical bowing in semiconductor alloys.

1983-08-22

359

Relationship between copper speciation and cyanobacterial distribution in harbors and other coastal environments. Final report, 1 July 1993--1 November 1998

The principle of conservation and transferability of chemical bonds explains the recent discovery by extended x-ray absorption fine-structure measurements of two unequal anion-cation bond lengths R/sub A/C and R/sub B/C in A/sub x/B/sub 1-x/C zinc-blende semiconductor alloys despite the close adherence of the lattice constant to the average value (Vegard rule). This bond alternation, manifested as a structural distortion to a local chalcopyrite coordination around the anions, explains also most of the observed optical bowing in semiconductor alloys.

360

Progress towards a 20 Ah/12 V zinc/air battery

The long term goal is to determine the ecological importance of specific toxic metals (copper and zinc) in harbors, through an understanding of their chemistry and biological effects at the base of marine food chains. This work provides information on potential problems with Zn and Cu, which may help to foresee problems in the future. Anthropogenic inputs of both metals are increasing; they are derived from diverse sources and are a simple function of population growth in coastal regions.

1998-11-01

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361

Probable role of trace elements of some medicinal plants in cardio-vascular diseases

Electrode areas, for the bifunctional O{sub 2}-electrodes and the pasted Zn-electrodes, have been successfully scaled up from 25 cm{sup 2} up to 250 cm{sup 2}. A filter press type cell was used to measure the cycle life of larger electrodes (100 cm{sup 2}). Up to now, more than 100 charge-discharge cycles (900 hours) with these scaled up Zn/O{sub 2}-cells could be demonstrated. (author) 2 figs., 2 refs.

1997-06-01

362

A number of herbal drugs are used in the Unani (Greco-Arab) System of Medicine for cardiovascular diseases. The herbs were analyzed by flame AAS and ICP-AES to determine if their therapeutic actions can be associated with the elements present in them. Cadmium, cobalt, chromium, copper, iron, potassium, magnesium, manganese, sodium, nickel, phosphorus, lead and zinc were some of the elements which play various roles in cardiovascular affections. An effort was made to correlate the role of these elements in cardiac diseases. (Auth.). 2 tabs., 32 refs.

363

Primary explosives

The present invention provides a compound of the formula (Cat).sup.+.sub.z[M.sup.++(5-nitro-1H-tetrazolato-N2).sup.-.sub.x(H.sub.2- O).sub.y] where x is 3 or 4, y is 2 or 3, x+y is 6, z is 1 or 2, and M.sup.++ is selected from the group consisting of iron, cobalt, nickel, copper, zinc, chromium, and manganese, and (Cat).sup.+ is selected from the group consisting of ammonium, sodium, potassium, rubidium and cesium. A method of preparing the compound of that formula is also disclosed.

2009-03-03

364

Primary explosives

The present invention provides a compound of the formula (Cat).sup.+.sub.z[M.sup.++(5-nitro-1H-tetrazolato-N2).sup.-.sub.x(H.sub.2- O).sub.y] where x is 3 or 4, y is 2 or 3, x+y is 6, z is 1 or 2, and M.sup.++ is selected from the group consisting of iron, cobalt, nickel, copper, zinc, chromium, and manganese, and (Cat).sup.+ is selected from the group consisting of ammonium, sodium, potassium, rubidium and cesium. A method of preparing the compound of that formula is also disclosed.

2011-01-25

365

Phase diagrams

Non-nitro radiation sensitizers

The description is presented of binary phase diagrams of titanium alloyed with the following elements: silver, aluminium, arsenic, gold, boron, barium, beryllium, bismuth, carbon, calcium, cadmium, cobalt, chromium, copper, iron, gallium, germanium, hydrogen, hafnium, indium, iridium, potassium, lithium, magnesium, manganese, molybdenum, nitrogen, sodium, niobium, nickel, oxygen, osmium, phosphorus, lead, palladium, platinum, plutonium, rhenium, lanthanium, cerium, preseodymium, neodymium, gadolinium, erbium, terbium, thulium, lutetium, rhodium, ruthenium, scandium, silicon, tin, strontium, tantalum, technetium, thorium, uranium, vanadium, tungsten, yttrium, ytterbium, zinc and zirconium.

366

Magnetic properties of glasses from geothite industrial wastes recycling (FeOOH)

This short communication aims to update the review of non-nitro radiation sensitizers (Shenoy and Singh 1985) and correct omissions. Work is mentioned and bibliography given for studied of cis-platinum, potassium permanganate, cobalt hexammine, sodium bromide, dimethylsulphoxide, zinc and copper ions, organic nitroxyl free radicals (TAN,TMPN and NPPN + PNAP), halogenated pyrimidines, organic and inorganic iodine containing compounds, diacetyl, acetone and acetophenone, rho-hydrobenzoic acid and its esters, pentobarbitone and secobarbitone, heparin and 9-anilinoacridines, dehydropiandosterone and paraquat. (U.K.).

367

Long-term monitoring of microleakage of dental cements by radiochemical diffusion

It has been carried out the magnetic properties determination for high iron oxide content glasses series obtained from a geothite red mud waste from the zinc hydrometallurgy and dolomite and glass cullet as main raw materials. It has been determined the magnetic susceptibility and magnetization values for the glasses here investigated. The results suggest that the magnetic behaviour are depending on the glass chemical composition, so that glasses can be differently classified like ferrimagnetic, ferromagnetic, superparamagnetic and paramagnetic. (Author) 6 refs.

368

Local Heine-Abarenkov model potential for III-V and II-VI covalent compounds

Radioactive "1"4C sucrose was found to be an ideal marker for microleakage because it did not penetrate tooth tissue, dental cement, or mounting resin. The main finding is that the adhesive cements--the glass-ionomer and polycarboxylate--are significantly more effective at preventing microleakage than are the traditional phosphate cements--silicate and zinc phosphate. The differences can be as high as two orders of magnitude. The adhesive cements provide almost perfect and reliable seals. By contrast, the nonadhesive cements are erratic sealants with most of the restorations leaking.

369

Electric vehicle getting up speed soon?; Kommt E-Mobil in Fahrt?

A local Heine-Abarenkov model potential is proposed for zinc blende-type crystals. The potential parameters are determined by satisfying the zero pressure condition and the first zero of the empirical pseudopotential interpolated from band calculations. Two sets of parameters are presented for thirteen tetrahedral compounds such as AlP, AlAs, AlSb, GaP, GaAs, GaSb, InP, InAs, InSb, ZnS, ZnSe, ZnTe, and CdTe.

1983-10-01

370

Effects of iodine deficiency on metabolism of metal ions in the rat brain by nuclear analytical techniques

A novel zinc-air battery might soon enhance the mileage and applications of electric vehicles. The battery named Zoxy battery weighs 80% less than a conventional lead battery, but has an equal amount of energy in store. (orig./CB) [Deutsch] Eine neuartige Zink-Luft-Batterie koennte vor allem dem Elektroauto groessere Reichweiten und neue Einsatzmoeglichkeiten erschliessen. Die sogenannte Zoxy-Batterie ist 80% leichter als eine herkoemmliche Bleibatterie - bei gleichem Energiegehalt. (orig.)

1997-12-31

371

Dialysis kinetics of motor oil additives

Iodine deficiency disorders (IDD) are one of most common nutritional deficiencies in the world. The nuclear analytical methods (ENAA, SRXRF and XRF) were employed to study the effect of iodine deficiency on the metal ion changes during the stage of brain development, combined with biochemical methods. The results show that the distributions of iron, copper and zinc varied to different extent in different brain regions and subcellular fractions of the ID rat brains. These distributional changes of trace elements might be associated with the brain damage caused by the iodine deficiency. (author)

2006-09-01

372

Anodic oxide coatings on metals and anodic protection /2nd revised and enlarged edition/. Anodnye oksidnye pokrytiia na metallakh i anodnaia zashchita /2nd revised and enlarged edition/

Studies dialysis kinetics of zinc dialkyldithiophosphates, detergent-dispersing agents, alkyl-phenols and base oils. It was established that diffusion kinetics of oil hydrocarbons through membrane of individual compounds and narrow fractions is described by Brinzinger's formula, which is identical to the kinetic reaction formula of the 1st order. It was shown that dialysis can be utilized to determine the content of the ''active substance'' only in sulphonate and alkylsalycilate additives. Increasing temperature from 20 to 40/sup 0/ results in an increased dialysis constant for all studied products by 1.4-1.9 times.

1982-01-01

373

ASARCO to pay over $59 million for damages and cleanup costs at Denver smelting facility

The theoretical principles underlying the formation of oxide and, in particular, anodic oxide coatings on metals produced by chemical oxidation, anodizing in solutions, and anodizing in cold plasmas are reviewed. The mechanisms and conditions of anodic oxidation are described, and the structure of anodic oxide coatings on aluminum, magnesium, beryllium, zinc, cadmium, iron, cobalt, nickel, titanium, zirconium, tantalum, and chromium alloys is examined. Attention is also given to various applictins of anodized coatings. 54 references.

1985-01-01

374

A hierarchical lattice structure and formation mechanism of ZnO nano-tetrapods

Since 1901, ASARCO, Inc. has owned and operated an 89-acre cadmium-refining smelter in the Globeville neighborhood of north Denver, Colorado. According to complaints filed by EPA and local residents, operations at the smelter have allegedly contaminated the air, ground water, surface water, and soil; contamination from arsenic, cadmium, lead, and zinc has occurred both onsite and offsite. EPA proposed to add the site to the National Priorities List (NPL) in May 1993.

1993-11-01

375

Verification of zinc injection applicability to Japanese BWRs

The existence of characteristic longitudinal optical and transverse optical phonons of cubic ZnO in ZnO nano-tetrapods is determined by Raman spectroscopy and first-principles calculations. Stacking sequence change at the boundary of the core and legs is also identified by high-resolution transmission electron microscopy. Based on this experimental and theoretical evidence, we demonstrate that the lattice structure of ZnO nano-tetrapods is hierarchical with a zinc blende core connecting to four wurtzite legs. Furthermore, we establish the atomic configuration and propose a formation mechanism induced by Laplace pressure in the initial growth stage of ZnO nano-tetrapods.

2009-08-12

376

The influence of modified water chemistries on metal oxide films, activity build-up and stress corrosion cracking of structural materials in nuclear power plants

The verification test program on zinc injection applicability to Japanese BWRs was started in 1997. Laboratory tests using high temperature water loops under BWR reactor water conditions are in progress. This paper is an interim report on results obtained so far. Co-58 and Zn-65 were simultaneously used in the Co radioactivity buildup test to evaluate zinc injection suppression effects towards cobalt deposition on pre-oxidized stainless steel. The following results were obtained. The Co deposition was suppressed effectively by Zn injection, even when there was a pre-oxide film. For the test piping that had the pre-oxide film formed under the NWC (normal water chemistry) condition, when soaked under the HWC (hydrogen water chemistry) condition a large amount of Co-58 was taken into a small part of the inner layer. The distribution ratio of Co-58 in the inner layer and outer layer of the oxide film was almost the same for both the pre-oxidized ...

2002-07-01

377

New electric-vehicle batteries

The primary coolant oxidises the surfaces of construction materials in nuclear power plants. The properties of the oxide films influence significantly the extent of incorporation of actuated corrosion products into the primary circuit surfaces, which may cause additional occupational doses for the maintenance personnel. The physical and chemical properties of the oxide films play also an important role in different forms of corrosion observed in power plants. This report gives a short overview of the factors influencing activity build-up and corrosion phenomena in nuclear power plants. Furthermore, the most recent modifications in the water chemistry to decrease these risks are discussed. A special focus is put on zinc water chemistry, and a preliminary discussion on the mechanism via which zinc influences activity build-up is presented. Even though the exact mechanisms by which zinc acts are not yet known, it is assumed ...

1999-03-01

378

Corrosion behaviour of non-ferrous metals in sea water

Electric vehicles that can`t reach trolley wires need batteries. In the early 1900`s electric cars disappeared when owners found that replacing the car`s worn-out lead-acid battery costs more than a new gasoline-powered car. Most of today`s electric cars are still propelled by lead-acid batteries. General Motors` Impact, for example, uses starting-lighting-ignition batteries, which deliver lots of power for demonstrations, but have a life of less than 100 deep discharges. Now promising alternative technology has challenged the world-wide lead miners, refiners, and battery makers into forming a consortium that sponsors research into making better lead-acid batteries. Horizon`s new bipolar battery delivered 50 watt-hours per kg (Wh/kg), compared with 20 for ordinary transport-vehicle batteries. The alternatives are delivering from 80 Wh/kg (nickel-metal hydride) up to 200 Wh/kg (zinc-bromine). A Fiat Panda travelled 260 km on a single charge of its ...

1994-12-31

379

The zinc/air battery test of the Deutsche Post AG - first results from practice; Der Zink/Luft-Batterie-Test der Deutschen Post AG - erste Ergebnisse aus der Praxis

The most typical kinds of corrosion of brasses are selective corrosion (dezincification) and stress corrosion. Prevention against these kinds of corrosion lies in application of arsenic alloy addition and appropriate heat treatment removing internal stresses as well as in maintaining the arsenic and phosphorus contents on a proper level. The most typical corrosion of cupronickels is the local corrosion. Selective corrosion occurs less often and corrosion cracking caused by stress corrosion in sea water does not usually occur. Crevice corrosion is found especially in places of an heterogeneous oxidation of the surface under inorganic deposits or under bio-film. Common corrosive phenomena for brasses and cupronickels are the effects caused by sea water flow and most often the impingement attack. Alloy additions improve resistance to the action of intensive sea water flow but situation in this field requires further improvement, especially if the cheaper kinds of alloys are concerned. ...

2004-07-01

380

ZnO nanoparticles enhanced antibacterial activity of ciprofloxacin against Staphylococcus aureus and Escherichia coli

The Deutsche Post AG is a transport company that with approximately 55,000 vehicles owns one of the biggest fleets in Europe. Being aware of its responsibility in the field of environmental policy it is looking for an alternative solution of an environmentally friendly vehicle drive system that also takes into account economic efficiency. Extensive investigations have led to a new energy storage based on the zinc-air energy system that has been developed and manufactured by the Israeli Company Electric Fuel Ltd. First tests showed an extraordinarily high capacity potential, drive values and ranges, which had been considered as impossible until that point of time. After these tests the Deutsche Post AG decided together with other well-known partners at home and abroad to carry out a territorial test with the zinc-air energy system in order to obtain insight into the day-to-day capability, economic efficiency, environmental friendliness under ...

1997-07-01

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381

British Library Electronic Table of Contents (United Kingdom)

Nanoparticle metal oxides offer a wide variety of potential applications in medicine due to the unprecedented advances in nanobiotechnology research. In this work, the effect of zinc oxide (ZnO) nanoparticles prepared by mechano-chemical method on the antibacterial activity of different antibiotics was evaluated using disk diffusion method against Staphylococcus aureus and Escherichia coli. The average size of ZnO nanoparticles was between 20 nm and 45 nm. Although ZnO nanoparticles (500 mg/disk) decreased the antibacterial activity of amoxicillin, penicillin G, and nitrofurantoin in S. aureus, the antibacterial activity of ciprofloxacin increased in the presence of ZnO nanoparticles in both test strains. A total of 27% and 22% increase in inhibition zone areas was observed for ciprofloxac...

2010-01-01

382

Zirconium for superior corrosion resistance

Waste and dust utilisation in shaft furnaces

Zirconium is a transition element located along with sister elements titanium and hafnium in Group IVB of the periodic table. It is grayish white metal, with a density somewhat less than carbon steel. Zirconium is the ninth most common metallic element in the earth's crust, and is more abundant than zinc, lead, nickel, or even copper. Zirconium is exceptionally resistant to corrosion by many common acids and alkalis. It is resistant to most organic acids, such as formic, acetic, lactic, and oxalic acids. It also has a high resistance to localized forms of corrosion, such as pitting, crevice corrosion, and stress corrosion cracking. Its corrosion resistance is caused by the formation of a dense, tenaciously adherent, chemically inert oxide film on the surface. This oxide film protects the base metal from both chemical and mechanical attack at temperatures up to about 400 C (750 F). This article describes zirconium's formability, machinability, corrosion resistance, ...

383

Technology base research on the slurry-zinc/air battery system: Final report

Wastes and dusts from steel industry, non-ferrous metallurgy and other branches can be utilised e.g. in agglomeration processes (sintering, pelletising or briquetting) and by injection into shaft furnaces. This paper deals with the second way. Combustion and reduction behaviour of iron- and carbon-rich metallurgical dusts and sludges containing lead, zinc and alkali as well as other wastes with and without pulverised coal (PC) has been studied when injecting into shaft furnaces. Following shaft furnaces have been examined: blast furnace, cupola furnace, OxiCup furnace and imperial-smelting furnace. Investigations have been done at laboratory and industrial scale. Some dusts and wastes under certain conditions can be not only reused but can also improve combustion efficiency at the tuyeres as well as furnace performance and productivity.

2005-07-01

384

Synthesis and characterization of conducting polymer composite (PAn/TiO{sup 2}) for cathode material in rechargeable battery

The slurry-Zn/air battery system has received renewed R and D interest because it does not have the shape-change problems of batteries with Zn-plate electrodes and can sustain higher current densities and specific peak power than other metal-air battery systems. Additional advantages of the slurry-Zn/air battery include safety, low environmental impact, potential low cost, and separation of energy density from power density functions for design purposes. In this work we present results obtained at the individual cell level as a basis to estimate the performance of a secondary slurry-Zn/air battery system. The expected specific energy of such systems has been increased as a result of the use of capacity-extension additives, which has been one of the major thrusts of this work. 8 refs., 20 figs., 5 tabs.

1988-08-01

385

Studies on biosorption and toxicity of heavy metals in bacteria; Untersuchungen zur Biosorption und zur Toxizitaet von Schwermetallen auf Bakterien

This paper deals with the preparation and characterization of polyaniline/TiO{sub 2} composite by XRD, UV-VIS spectra, TGA/DTA and FTIR. The composite is used as a cathode material for rechargeable battery comprising of zinc container as the anode, cellulose acetate as the separator and polyvinyl sulfate and carboxy methyl cellulose as the solid polymer electrolytes (SPE). By using the PAn/TiO{sub 2} composite as the cathode material, the cylindrical AA type rechargeable battery was fabricated and the following output was observed. The open circuit voltage (OCV) is 1.4 V and current is 250 mA to 1.0 A, 50 recharge cycles, power density is 350 A h/kg and power efficiency is 70%.

2003-02-01

386

Studies of crystalline CdZnTe radiation detectors and polycrystalline thin film CdTe for X-ray imaging applications

Biosorption behaviour of and toxic effects of heavy metals in submersed and immobilised microorganisms was studied in batches and in continuous processes in an airlift-recycle reactor. Nickel, cadmium, and zinc were used as heavy metals. (orig./VHE) [Deutsch] Am Beispiel einer Naphthalin-2-sulfonsaeure-abbauenden Kultur wurde das Biosorptionsverhalten und die toxische Wirkung von Schwermetallen auf submerse und immobilisierte Mikroorganismen im Batch-Ansatz und im kontinuierlichen Betrieb in einem Airlift-Schlaufenreaktor untersucht. Als Schwermetalle wurden Nickel, Cadmium und Zink eingesetzt. (orig./VHE)

1993-09-01

387

Prospective observation of CAD/CAM titanium ceramic single crowns: A three-year follow up

The development of a replacement to the conventional film based X-ray imaging technique is required for many reasons. One possible route for this is the use of a large area film of a suitable semiconductor overlaid on an amorphous silicon readout array. A suitable semiconductor exists in cadmium telluride and its tertiary alloy cadmium zinc telluride. In this thesis the spectroscopic characteristics of commercially available CZT X- and gamma-radiation detectors are established. The electronic, optical, electro-optic, structural and compositional properties of these detectors are then investigated. The attained data is used to infer a greater understanding for the carrier transport in a CZT radiation detector following the interaction of a high energy photon. Following this a method used to fabricate large area films of CdTe on a commercial scale is described. This is cathodic electrodeposition from an aqueous electrolyte. The theory and experimental arrangement for ...

2001-01-01

388

British Library Electronic Table of Contents (United Kingdom)

Statement of problem Computer-aided design/computer-aided manufacturing (CAD/CAM) titanium ceramic restorations were developed with the potential for replacing expensive, high noble metal ceramic restorations. However, there is a lack of information about the clinical performance of CAD/CAM titanium ceramic single crowns. Purpose The purpose of this study was to evaluate CAD/CAM titanium ceramic single crowns after 3 years in function. Material and methods A total of 41 crowns were fabricated for 21 patients. The titanium copings were CAD/CAM milled (Everest CAD/CAM system) with an even thickness of 0.5 mm, and low-fusing veneering porcelain (Vita Titanium Porcelain) was added incrementally. The crowns were cemented using zinc phosphate cement after confirming that there were no mechanical...

2009-01-01

389

Properties of transition metal-doped zinc chalcogenide crystals for tunable IR laser radiation

Pilot project ''measurement of efficacy'' - biological monitoring of antimony pollution in the Munich test area using a standardized grass culture

The spectroscopic properties of Cr{sup 2+}, Co{sup 2+}, and Ni{sup 2+}-doped single crystals of ZnS, ZnSe, and ZnTe have been investigated to understand their potential application as mid-IR tunable solid-state laser media. The spectroscopy indicated divalent Cr was the most favorable candidate for efficient room temperature lasing, and accordingly, a laser-pumped laser demonstration of Cr:ZnS and Cr:ZnSe has been performed. The lasers` output were peaked at {approximately} 2.35 {mu}m and the highest measured slope efficiencies were {approximately} 20% in both cases.

1995-03-17

390

On stage III and stage IV recovery of zinc after alpha-particle irradiation

This pilot project was carried out for the purpose of testing methods for active biological monitoring. It covered a period of three years (until September 1994), including two years of exposure. The measurements served to determine pollutant levels in plants used as animal fodder and dust-borne heavy metal concentrations in different sites and, on this basis, to obtain indirect information on human exposure. Among others, the pilot project investigated the suitability of Italian rye-grass as a biological indicator for aluminium, arsenic, cadmium, cobalt, chromium, copper, iron, mercury, magnesium, manganese, nickel, lead, platinum, antimony, titanium, and zinc. (orig./GL).

391

New highly active oxygen reduction electrode for PEM fuel cell and Zn/air battery applications (NORA). Final report

Stage III and stage IV recovery have been investigated resistometrically following 6.1 MeV alpha-particle irradiation at 4.2 K. The activation energy associated with stage III shows a gradual increase from 0.35 +- 0.02 eV to 0.39 +- 0.02 eV. Stage IV (155 to 180 K) is associated with an activation energy of 0.46 +- 0.03 eV. The present results are compared with those obtained after electron and neutron irradiation. The stage III recovery kinetics are interpreted in terms of the Goesele-Seeger theory for interstitial migration in highly anisotropic hexagonal metals. Stage IV is ascribed to monovacancy migration. (author).

392

Near term and future alternative clean vehicle technologies

This illustrated final report for the Swiss Federal Office of Energy (SFOE) presents the results of a project concerning a new, highly active oxygen reduction electrode for PEM fuel cell and zinc/air battery applications. The goal of this project was, according to the authors, to increase the efficiency of the oxygen reduction reaction by lowering the activation polarisation through the right choice of catalyst and by lowering the concentration polarisation. In this work, carbon nanotubes are used as support material. The use of these nanotubes grown on perovskites is discussed. Theoretical considerations regarding activation polarisation are discussed and alternatives to the use of platinum are examined. The results of experiments carried out are presented in graphical and tabular form. The paper is completed with a comprehensive list of references.

2008-04-15

393

National technical report (Matsushita Electric Industrial Company), Vol. 40, No. 4, August 1994. Special issue on batteries

Availability of a natural gas-powered van that meets California`s ultra low emission vehicle requirements and has a 300-km range was reported. A similar van with an electric system giving a range of 240 km was also within sight. Regarding the limitations of electric batteries it was suggested that a super capacitor may allow systems to achieve higher energy densities; a refuelable zinc-air battery could be considered for vehicle use. While the prospect for emissions improvement of gasoline vehicles has clearly improved in recent years, the relative costs of infrastructure, vehicle and fuel for the the alternative fuels compared with gasoline demonstrate the difficulty the alternative fuels have in taking market share from gasoline. For the next decade, gasoline, propane and CNG are expected to be the dominant fuels for vehicles. After that, the leading fuel will be the one that has been most extensively researched and developed during the decade. 17 refs.

1994-12-31

394

Multielement analysis of air samples. Determination of iron, zinc, lead, and bromine content by the radionuclide X-ray fluorescence analysis

Contents: recent trend of battery technologies; alkaline manganese battery with no mercury addition; high capacity zinc-air battery series for hearing aids; characteristics of vanadium-niobium-lithium rechargeable battery; high-energy density lithium-ion rechargeable battery; lithium polymer rechargeable battery: polymer gel electrolyte and electrode; high-capacity ni-cd battery sm120; high-capacity nickel-metal hydride battery; sealed-type batteries for electric vehicles; high-temperature-durable calcium-type battery for automobiles; sealed lead acid batteries for upss; solar cell power unit; solid oxide fuel cell (1); battery management system.

1994-08-01

395

Modeling of batteries and fuel cells; Proceedings of the Symposium, Phoenix, AZ, Oct. 13-19, 1991

Radionuclide X-ray fluorescence analysis for nondestructive determination of Fe, Zn, Pb, and Br in air samples collected on nitrocellulose membrane filter Synpor 4 is described. A /sup 238/Pu source for the excitation and a semiconductor Si/Li detector for the detection of characteristic and L-fluorescent radiation of the above elements were used. A correction method based upon the measurements of simple or multiple Compton scattering for compensation of varying mass per unit area values in sample deposits was theoretically proposed and experimentally tested. The results obtained both with and without the correction were compared and good agreement with those given by atomic absorption spectrometry was observed.

1981-01-01

396

Mathematical modeling of a primary zinc/air battery

The present volume on modeling of batteries and fuel cells discusses the significance of the effectiveness factor for flooded porous electrodes, active pore distribution spectroscopy for characterizing porous battery electrodes, the agglomerate model for porous electrodes, and dynamic-performance measurements of battery cells for electric vehicles and other applications. Attention is given to mathematical modeling of a primary zinc/air battery, mathematical modeling of Grace Li-TiS2 cells, modeling of electrocrystallization processes in battery systems, and rotating disk electrode studies in molten Li/K carbonate eutectic. Topics addressed include the variability of nickel oxide cathode dissolution in molten carbonate fuel cells, water transport properties of fuel cell ionomers, modeling water content effects in polymer electrolyte fuel cells, and computer algebra applied in electrochemistry and fuel cell modeling.

1991-01-01

397

Long-distance transport, vacuolar sequestration, tolerance, and transcriptional responses induced by cadmium and arsenic

This paper reports on the mathematical model developed by Sunu and Bennion that has been extended to include the separator, precipitation of both solid ZnO and K{sub 2}Zn(OH){sub 4}, and the air electrode, and has been used to investigate the behavior of a primary Zn-Air battery with respect to battery design features. Predictions obtained from the model indicate that anode material utilization is predominantly limited by depletion of the concentration of hydroxide ions. The effect of electrode thickness on anode material utilization is insignificant, whereas material loading per unit volume has a great effect on anode material utilization; a higher loading lowers both the anode material utilization and delivered capacity. Use of a thick separator will increase the anode material utilization, but may reduce the cell voltage.

1992-04-01

398

British Library Electronic Table of Contents (United Kingdom)

Iron, zinc, copper and manganese are essential metals for cellular enzyme functions while cadmium, mercury and the metalloid arsenic lack any biological function. Both, essential metals, at high concentrations, and non-essential metals and metalloids are extremely reactive and toxic. Therefore, plants have acquired specialized mechanisms to sense, transport and maintain essential metals within physiological concentrations and to detoxify non-essential metals and metalloids. This review focuses on the recent identification of transporters that sequester cadmium and arsenic in vacuoles and the mechanisms mediating the partitioning of these metal(loid)s between roots and shoots. We further discuss recent models of phloem-mediated long-distance transport, seed accumulation of Cd and As and rec...

2011-01-01

399

Is Phytalgic(R) a goldmine for osteoarthritis patients or is there something fishy about this nutraceutical? A summary of findings and risk-of-bias assessment

DEFF Research Database (Denmark)

A food supplement containing fish oils, urtica dioica, zinc, and vitamin E (Phytalgic) for osteoarthritis (OA) has now been tested in a placebo-controlled trial for 3 months and according to the authors has a very large clinical effect, considerably larger than that of any other known product. Even experts endorsing nutraceuticals for OA symptoms would probably agree that a nutraceutical with an effect size above 0.5 is rarely seen. Despite our concerns about the fact that trial registration took place after the study was completed and the likelihood that patients would note the taste of fish, a circumstance that would lead to detection bias, we consider these data promising though with a high risk of bias.

2010-01-01

400

Exploiting unique germplasm resources of leguminous trees: Prosopis, leucaena and acacia. Final report, August 31, 1982-August 30, 1992

Electrically rechargeable zinc/air battery: a high specific energy system

In Haiti, and other semiarid regions of the world, the need for fuelwood and forage is critical. The report summarizes research conducted over a ten year period on developing replicable plantations of leguminous trees in semiarid lands, especially in areas near seawater salinity levels. Research included greenhouse and laboratory work followed by field trials in Haiti and focused on two species: Prosopis and Leucaena. (Acacia is mentioned in the report's title but not in the report itself.) Results were as follows. (1) Greenhouse experiments identified leaf diagnostic criteria indicating mineral nutrient deficiencies in field trees. It also established the importance of micronutrients, especially zinc, in permitting growth in high pH (9.0) soils.

1992-01-01

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401

Effects of Copper, Cadmium, and Zinc on the Hatching Success of Brine Shrimp (Artemia franciscana)

This contribution describes our research and development efforts towards the demonstration of a light-weight, low-cost 12 V/20 Ah electrically rechargeable Zn/air battery. We successfully developed electrodes having active areas of up to 200 cm{sup 2}. Deep discharge cycles at different currents as well as current-voltage curves are reported for a 10 cell Zn/air battery (serial connection) with a rated capacity of 20 Ah. Based on the discharge cycle at a power of 19 W, and the weight of the battery, a specific energy of more than 90 Wh/kg could be evaluated for the whole system. (author) 4 figs., 1 tab., 5 refs.

1999-08-01

402

British Library Electronic Table of Contents (United Kingdom)

Previous studies indicate that the hatching success of brine shrimp (Artemia franciscana) cysts is surprisingly sensitive to ambient metal concentrations. These studies estimated median effective concentrations (EC50s) of 7, 5, and 28??g l?1 for Cd, Cu, and Zn, suggesting that the hatching end point for A. franciscana is the most sensitive tested to date for Cd and Zn in saline environments and comparable in sensitivity with the most sensitive tested to date for Cu. Furthermore, these data suggest that brine shrimp are at significant risk from Cu and Zn in Great Salt Lake (GSL), UT, where ambient concentrations as high as 10 and 14??g l?1, respectively, have been measured. Given that brine shrimp appear to be successfully reproducing in GSL, we hypothesized that these toxicity values were ...

2006-01-01

403

Chemical plant factors affecting resistance in sugarcane in against Scirpophaga Nivella f

Catalytic desulfurization of organic sulfur compounds over zeolite catalysts

The study was conducted during 2000 to determine the role of various chemical plant factors viz., total minerals, nitrogen, fat contents, carbohydrate, macro an micro nutrients in the leaves of five genotypes of sugarcane i.e., BF-162, SPSG-26, L-118, CP-43/33 and CP-72/2086 by correlating the infestation of top borer, Scirpophaga Nivella F. at tillering stage. None of the genotype was found completely resistant to the pest. CP-43/33 and BF-162 proved susceptible and resistant varieties, respectively. Total mineral, manganese and copper contents did not show significant correlation with the pest infestation, whereas nitrogen, potassium, calcium, magnesium and ferrous contents played a positive and significant role. Phosphorous, carbohydrates, fats and zinc contents played a significant and negative effect on the pest infestation at tillering stage. (author)

404

Cardiac Pacing: Memories of a Bygone Era

In the dehydrodesulfurization of ethanethiol at 400/sup 0/C, the activities of sodium X, Y, and A zeolites decreased in the order given as did the activities of nickel, cobalt, zinc, cadmium, copper, silver, lead, manganese, barium, calcium, sodium, and iron Y zeolite catalysts. A volcano-shape order was observed between the catalytic activity and the electronegativity of the metal ions. The changes in the activity of hydrogen Y zeolite catalyst in ethanethiol dehydrodesulfurization and cumene dealkylation by calcination agreed with the decrease in the Broensted acidity but were independent of Lewis acidity. For hydrodesulfurization of thiophene, the activities of nickel, cobalt, copper, and silver Y zeolite catalysts decreased in the order given and were greater than for a commercial hydrodesulfurization catalyst; reduced and presulfided catalysts showed selective hydrodesulfurization activity. Addition of 5% of nickel or molybdenum oxides to cobalt or nickel Y ...

1980-01-01

405

British Library Electronic Table of Contents (United Kingdom)

The first cardiac pacemaker implants occurred in the late 1950s and involved insertion of epicardial or epimyocardial leads and abdominal pulse generators. By the mid 1960s, cardiologists were making attempts to insert transvenous leads into the right ventricle. These early unipolar leads had large, polished, high polarization electrodes, no fixation device, and no lumen in which to place a stylet for lead positioning. The lead implantation procedures were usually long and the irradiation to both patient and operator excessive. Pulse generators were powered by zinc-mercury cells, which were large, unreliable, and prone to sudden output failure. Postoperative complications such as lead dislodgement, exit block, and premature power source failure were very common with most patients requiring...

2008-01-01

406

Advanced process control technologies for continuous annealing line and galvanizing line; Hakkoban no renzoku shodon oyobi hyomen shori rain no antei tuban gijutsu to koseido hinshitsu seigyo gijutsu

A study on effects of parameters in the Lagrangian code based on F.E.M. through oblique dual-plates perforation phenomena

Kawasaki Steel has constructed many facilities for 15 years to produce cold rolled products and galvanized products in Mizushima Works and Chiba Works. To efficiently and stably produce high and uniform quality products, various new control methods have been developed and applied to these new facilities. Especially, temperature control in a continuous annealing line, zinc coating control in a continuous galvanizing line or paint coating control in a multi-purpose coating line and tension control to achieve stable processing are the most advanced technologies and are introduced in this paper. (author)

1999-12-01

407

Development of process technology for large-area thin-film solar modules based on compound semiconductors. Final report; Entwicklung der technologischen Grundlagen fuer grosse Photovoltaikmodule auf Basis von Duennschicht-Verbindungshalbleitern. Abschlussbericht

This study is concerned to the perforation phenomena of the oblique dual-plate by projectile. Experiment and simulation related to that was carried out. the variables considered in this phenomena include the electrolytic zinc coated steel sheet and carbon steel rod. In the former, the confirmation and projectile velocity possible phenomena of real phenomena is done, the latter, the effect of parameter such as time-step and grid space length is analyzed by using the three-dimensional Lagrangian explicit time-integration finite element code, HEMP. This code use the eight node hexahedral elements and in this study, Von-Mises Criteria is used as the strength model, Mie-Gruneisen is as the Equation of State. The simulation was performed by contrast with the experiment. Through the calibration of the parameter of Lagrangian code, reasonable result was approached.

2004-11-03

408

Zinc-blende--wurtzite polytypism in semiconductors

A cooperative effort of the Center for Solar Energy and Hydrogen Research (ZSW) and Phototronics Solartechnik GmbH (PST) aimed at the transfer of highly efficient solar cells developed on a laboratory scale, to large-area thin-film solar modules suitable for production. This work was based on research and development at the Institute for Physical Electronics (IPE) of Stuttgart University and ZSW on one hand, and on the know-how of PST in regard to large-area module fabrication on the other hand. The various thin-film layers of the cells and modules comprize molybdenum as rear contact, copper-indium(gallium)-diselenide (CIGS) as absorber material, the combination of cadmium sulphide (CdS) and ZnO as window layer. To produce these layers on large areas (30x30 cm{sup 2}), equipment was constructed and procedures were developed. Monolithic series connection of cells, used in other thin-film technologies, was studied and optimized by suitable patterning procedures, such ...

1998-06-01

409

Structural Insights into the Interaction of the Evolutionarily Conserved ZPR1 Domain Tandem with Eukaryotic EF1A, Receptors, and SMN Complexes

The zinc-blende (ZB) and wurtzite (W) structures are the most common crystal forms of binary octet semiconductors. In this work we have developed a simple scaling that systematizes the {ital T}=0 energy difference {Delta}{ital E}{sub W{minus}ZB} between W and ZB for all simple binary semiconductors. We have first calculated the energy difference {Delta}{ital E}{sub W{minus}ZB}{sup LDF}({ital AB}) for AlN, GaN, InN, AlP, AlAs, GaP, GaAs, ZnS, ZnSe, ZnTe, CdS, C, and Si using a numerically precise implementation of the first-principles local-density formalism (LDF), including structural relaxations. We then find a {ital linear} scaling between {Delta}{ital E}{sub W{minus}ZB}{sup LDF}({ital AB}) and an atomistic orbital-radii coordinate {ital {tilde R}}({ital A},{ital B}) that depends only on the properties of the free atoms {ital A} and {ital B} making up the binary compound {ital AB}. Unlike classical structural coordinates (electronegativity, atomic sizes, electron ...

1992-10-15

410

Remote power systems with advanced storage technologies for Alaskan villages

Eukaryotic genomes encode a zinc finger protein (ZPR1) with tandem ZPR1 domains. In response to growth stimuli, ZPR1 assembles into complexes with eukaryotic translation elongation factor 1A (eEF1A) and the survival motor neurons protein. To gain insight into the structural mechanisms underlying the essential function of ZPR1 in diverse organisms, we determined the crystal structure of a ZPR1 domain tandem and characterized the interaction with eEF1A. The ZPR1 domain consists of an elongation initiation factor 2-like zinc finger and a double-stranded {beta} helix with a helical hairpin insertion. ZPR1 binds preferentially to GDP-bound eEF1A but does not directly influence the kinetics of nucleotide exchange or GTP hydrolysis. However, ZPR1 efficiently displaces the exchange factor eEF1B from preformed nucleotide-free complexes, suggesting that it may function as a negative regulator of eEF1A activation. Structure-based mutational and ...

2007-01-01

411

Precious Metals in Municipal Solid Waste Incineration Bottom Ash

Remote Alaskan communities pay economic and environmental penalties for electricity, because they must import diesel as their primary fuel for electric power production, paying heavy transportation costs and potentially causing environmental damage with empty drums, leakage, and spills. For these reasons, remote villages offer a viable niche market where sustainable energy systems based on renewable resources and advanced energy storage technologies can compete favorably on purely economic grounds, while providing environmental benefits. These villages can also serve as a robust proving ground for systematic analysis, study, improvement, and optimization of sustainable energy systems with advanced technologies. This paper presents an analytical optimization of a remote power system for a hypothetical Alaskan village. The analysis considers the potential of generating renewable energy (e.g., wind and solar), along with the possibility of using energy storage to take full advantage of ...

1997-12-01

412

Investigation by XRF and XRD of Zn and Fe in Fe{sub x} Zn{sub 1-x} thin films

Municipal solid waste incineration (MSWI) bottom ash contains economically significant levels of silver and gold. Bottom ashes from incinerators at Amsterdam and Ludwigshafen were sampled, processed, and analyzed to determine the composition, size, and mass distribution of the precious metals. In order to establish accurate statistics of the gold particles, a sample of heavy non-ferrous metals produced from 15 tons of wet processed Amsterdam ash was analyzed by a new technology called magnetic density separation (MDS). Amsterdam's bottom ash contains approximately 10 ppm of silver and 0.4 ppm of gold, which was found in particulate form in all size fractions below 20 mm. The sample from Ludwigshafen was too small to give accurate values on the gold content, but the silver content was found to be identical to the value measured for the Amsterdam ash. Precious metal value in particles smaller than 2 mm seems to derive mainly from waste of electrical and electronic equipment ...

2009-04-15

413

Investigation by XRF and XRD of Zn and Fe in Fex Zn1-x thin films

Fe{sub x}Zn{sub 1-x} alloys were electrochemically deposited on aluminum substrates from a sulfate bath. The K{beta}/K{alpha} x-ray intensity ratios of Zn and Fe in Fe{sub x}Zn{sub 1-x} thin films have been experimentally studied. The energy dispersive x-ray fluorescence (EDXRF) technique was used to measure K x-ray photons. Samples were excited by using 59.5 keV photons emitted by a 50 mCi {sup 241}Am radioactive source. The emitted K x-rays were detected by an Ultra-LEGe detector having a resolution of 150 eV at 5.9 keV. In addition, the effect of bath composition on the phase structure was investigated by x-ray diffraction (XRD) analysis. The composition of the thin films was analyzed by atomic absorption spectrometry analysis. Iron content was shown to strongly affect the structure of Zn-Fe alloys. It was found that the K-shell x-ray intensity ratio changed in Fe{sub x}Zn{sub 1-x} thin films for different values of x. The reason for this change may be that the electronegativity of ...

2008-12-15

414

Impact of heavy metals on macro-invertebrate fauna of the thaddo stream

FexZn1-x alloys were electrochemically deposited on aluminum substrates from a sulfate bath. The K?/K? x-ray intensity ratios of Zn and Fe in FexZn1-x thin films have been experimentally studied. The energy dispersive x-ray fluorescence (EDXRF) technique was used to measure K x-ray photons. Samples were excited by using 59.5 keV photons emitted by a 50 mCi 241Am radioactive source. The emitted K x-rays were detected by an Ultra-LEGe detector having a resolution of 150 eV at 5.9 keV. In addition, the effect of bath composition on the phase structure was investigated by x-ray diffraction (XRD) analysis. The composition of the thin films was analyzed by atomic absorption spectrometry analysis. Iron content was shown to strongly affect the structure of Zn-Fe alloys. It was found that the K-shell x-ray intensity ratio changed in FexZn1-x thin films for different values of x. The reason for this change may be that the electronegativity of iron is higher than that of zinc ...

2008-12-01

415

Heavy metals in earthworms of Baden-Wuerttemberg. Part 1. Metal contents in earthworms from long-term forest observation plots; Schwermetalle in Regenwuermern Baden-Wuerttembergs. Teil 1. Metallgehalte in Regenwuermern von Wald-Dauerbeobachtungsflaechen

Impact of some heavy metals like zinc, lead, copper, chromium and cadmium were studied at four spots on the macro-invertebrate fauna of the Thaddo stream, a tributary of Malir River. This was in correlation with an earlier study on the physico-chemical aspects of water which showed a severe pollution in this stream. Present data for the qualitative and quantitative analyses of macro-invertebrates and the ranges of heavy metals (Zn 0.5-3.5, Pb 0.90-1.42, Cu 0.35-0.93, Cr 0.0-0.08 and Cd 0.003-0.01 ppm) in the water samples also indicate high level of pollution in the stream. Macro-invertebrate fauna comprises only of aquatic insects which include larvae of Chironomus spp., adults of the Notonectus sp., and nymphs of Gomphus sp. (dragon fly) belonging to the order Diptera , Hemiptera and Odonata, respectively. Quantitatively Notonectus sp. predominated and followed by Chironomus larvae. The maximum concentrations of all heavy metals were recorded at spot 3. A general ...

416

Elastic properties and structural studies on some zinc-borate glasses derived from ultrasonic, FT-IR and X-ray techniques

Since 1984 the Environmental Protection Agency (LfU) of the State of Baden-Wuerttemberg has been investigating the heavy metal burden of earthworms from representative long-term forest observation plots. These investigations are aimed at elucidating and assessing adverse effects of pollutants on the soil biocenosis. Methods: At first only lead and cadmium were measured in the worms; in repetitive measurements over the years further metals or metalloid elements such as aluminum, arsenic, chromium, cobalt, copper, manganese, mercury, nickel, thallium, vanadium, and zinc were added to the agenda. Results and conclusion: The frequency distribution of the metals in the earthworms was characterized statistically. For the first time state-wide background values, normal values and threshold values were established for all the elements measured. A comparable study with a similar range of parameters is known neither nationally nor internationally. Time trend studies have ...

2006-08-15

417

Borehole geophysics for delineating the geological structure in the Sakonishi prospect, the Hida area, Japan; Hida chiiki Sako nishi chiku ni okeru boring ko riyo butsuri tansa ni yoru chishitsu kozo kaiseki

Glasses in the system (1 - x) [29Na{sub 2}O- 4Al{sub 2}O{sub 3}- 67B{sub 2}O{sub 3}]- xZnO (0 {<=} x {<=} 35 mol%), have been prepared by the melt quenching technique. Elastic properties, X-ray and FT-IR spectroscopic studies have been employed to study the role of ZnO on the structure of the investigated glass system. Elastic properties and Debye temperature have been investigated using sound wave velocity measurements at 4 MHz at room temperature. The results showed that the density increases and the molar volume decreases while both sound velocities and the determined glass transition temperatures decrease with increase in x. X-ray and infrared spectra of the glasses reveal that the borate network consists of diborate units and is affected by the increase in the concentration of ZnO content. These results are interpreted in terms of the decrease in the N{sub 4} values (fraction of tetrahedral coordinated boron atoms), and substitution of longer bond lengths of Zn-O in ...

2009-05-05

418

A zinc-air battery and flywheel zero emission vehicle

In order to discuss effectiveness of physical exploration in the Sakonishi prospect in the Hida area, physical exploration was carried out by utilizing bored wells. This area contains the Kamioka mine, one of the major base metal mines in Japan, where electrical exploration has been attempted several times in the past. No effective results have been obtained, however, because specific resistance contrast between mine beds and base rocks is too small, and the topography is too steep making site workability inferior. As part of the investigations on geological structures over wide areas, electrical logging (specific resistance and natural potential) was performed in fiscal 1995 and 1996 by utilizing the boreholes. Induced polarization logging was also conducted on the same boreholes. A traverse line on the ground with a length of 600 m and boreholes were used to execute specific resistance tomography. Clear extraction was possible on a fault structure which is thought related with ...

1997-05-27

419

Use of genetic parameters in coal classification

In response to the 1990 Clean Air Act, the California Air Resources Board (CARB) developed a compliance plan known as the Low Emission Vehicle Program. An integral part of that program was a sales mandate to the top seven automobile manufacturers requiring the percentage of Zero Emission Vehicles (ZEVs) sold in California to be 2% in 1998, 5% in 2001 and 10% by 2003. Currently available ZEV technology will probably not meet customer demand for range and moderate cost. A potential option to meet the CARB mandate is to use two Lawrence Livermore National Laboratory (LLNL) technologies, namely, zinc-air refuelable batteries (ZARBs) and electromechanical batteries (EMBs, i. e., flywheels) to develop a ZEV with a 384 kilometer (240 mile) urban range. This vehicle uses a 40 kW, 70 kWh ZARB for energy storage combined with a 102 kW, 0.5 kWh EMB for power peaking. These technologies are sufficiently near-term and cost-effective to plausibly be in production by the ...

1995-10-03

420

Trace metal characterization of the U-Al matrix by atomic spectroscopy

The extensive reserves of mined coal types, their great variety and the complexity of the composition and properties, as well as their important role as an energy fuel and industrial feedstock, cause one to give special attention to their classification. Of course, one of the principal fields of technological processing of coal is coking. In addition to the production of blast furnace coke, in the future specialized plants will be developed for production of coke and other carbonized materials for non-blast-furnace processes (electrothermal processes, production of calcium carbide, ferroalloys, zinc, yellow phosphorus, copper, etc.). One important area is new nonfuel uses, including a number of processes for processing of coal feedstocks to obtain a wide range of carbonaceous materials (coal-graphite products, carbon black, adsorbents, etc.), liquid fuels, and chemical products. In choosing a given area of coal utilization a determining factor is the ...

1984-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

421

Recent Progress in CdTe and CdZnTe Detectors

Uranium-aluminum alloys with a significant enrichment of uranium with "2"3"3U or "2"3"5U serve as nuclear fuels in research reactors. The quality assurance of this fuel requires, among other things, precise knowledge that all trace metal constituents that affect neutron economy, fuel integrity, and fuel fabrication process parameters are well within the specification limits. Trace metal characterization of "2"3"5U-Al alloy has been carried out by atomic spectrometry. The trace metal constituents of interest are grouped into common metals (silver, boron, calcium, cadmium, cobalt, chromium, copper, iron, magnesium, manganese, molybdenum, sodium, nickel, lead, silicon, tin, titanium, vanadium, tungsten, and zinc) and lanthanides (cerium, dysprosium, europium, gadolinium, holminium, lutetium, samarium, and terbium). The elements yttrium and zirconium are grouped with the latter in view of the chemical separation procedure used. The alloy samples are dissolved in 6 M ...

422

Quinary metallic glass alloys

Cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) have been regarded as promising semiconductor materials for hard X-ray and Gamma-ray detection. The high atomic number of the materials (Z_{Cd} =48, Z_{Te} =52) gives a high quantum efficiency in comparison with Si. The large band-gap energy (Eg ~ 1.5 eV) allows us to operate the detector at room temperature. However, a considerable amount of charge loss in these detectors produces a reduced energy resolution. This problem arises due to the low mobility and short lifetime of holes. Recently, significant improvements have been achieved to improve the spectral properties based on the advances in the production of crystals and in the design of electrodes. In this overview talk, we summarize (1) advantages and disadvantages of CdTe and CdZnTe semiconductor detectors and (2) technique for improving energy resolution and photopeak efficiencies. Applications of these imaging detectors in future hard X-ray and ...

2001-01-01

423

Pulse Rise Time Characterization of a High Pressure Xenon Gamma Detector for use in Resolution Enhancement

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

424

Preparation of immission dust samples for the analysis of toxic substances in dust by atomic emission spectroscopy with inductively coupled plasma

High pressure xenon ionization chamber detectors are possible alternatives to traditional thallium doped sodium iodide (NaI(Tl)) and hyperpure germanium as gamma spectrometers in certain applications. Xenon detectors incorporating a Frisch grid exhibit energy resolutions comparable to cadmium/zinc/telluride (CZT) (e.g. 2% (at) 662keV) but with far greater sensitive volumes. The Frisch grid reduces the position dependence of the anode pulse risetimes, but it also increases the detector vibration sensitivity, anode capacitance, voltage requirements and mechanical complexity. We have been investigating the possibility of eliminating the grid electrode in high-pressure xenon detectors and preserving the high energy resolution using electronic risetime compensation methods. A two-electrode cylindrical high pressure xenon gamma detector coupled to time-to-amplitude conversion electronics was used to characterize the pulse rise time of deposited gamma photons. Time ...

2000-01-01

425

Preparation of a "6"2Zn-"6"2Cu generator and of "6"1Cu following alpha particle irradiation of a nickel target

Samples of air-dust-concentration- and air-dust-deposit measurements were digested by a standardized wet digestion procedure and the amounts of substances in the dust according to class I TA Luft by Atomic Emission Spectroscopy with Inductively Coupled Plasma (AES-ICP). The characteristic values for procedures according to VDI 2449, sheet 1, were determined for lead, vanadium, cadmium, chromium, copper, nickel and zinc. By partial automatic control of the digestion procedure the personel expenditure of work could be reduced by a factor 13. Dust filter samples were analysed without sample preparation by evaporating the material with a solid state laser. The absolute detection limit was between 1 and 100 ng/cm"2 for the elements arsenic, cadmium, cobalt, chromium, mercury, antimony, selen and thallium. For sampling by means of the Beta-Staubmeter the relative detection limits for the laser-ICP were 10-fold lower than by use of a nebulizer. (orig.).

426

Phytoavailability and fractionation of copper, manganese, and zinc in soil following application of two composts to four crops

The "6"2Zn-"6"2Cu generator system is one of the few which yield a pure positron emitting daughter. The authors have developed a method for the preparation of this generator system following 32 MeV #alpha# particle bombardment of nickel targets. The chemical processing involves two stages: first a hydrous zirconium oxide column is used at pH 4-5 to separate the zinc and copper activities produced in the target nickel, and secondly, a conventional anion exchange column is used to retain the "6"2Zn and remove all copper activities in 2M HCl. This column serves as the "6"2Cu generator which will yield pure "6"2Cu repeatedly, free from "6"2Zn and other impurities, in a mixture of HCl and NaCl. A method is outlined also to obtain a solution of "6"2Zn using the hydrous zirconium oxide (HZO) column. "6"1Cu can be prepared as a by-product in the above procedure, but a method for the preparation of "6"1Cu alone using an 18 MeV #alpha# particle beam on a nickel target and ...

427

Performance of ZnMoO4 crystal as cryogenic scintillating bolometer to search for double beta decay of molybdenum

Two experiments were conducted to evaluate the effect of compost addition to soil on fractionation and bioavailability of Cu, Mn, and Zn to four crops. Soils growing Swiss chard (Beta vulgaris var. cicla L.) and basil (Ocimum basilicum L.) were amended (by volume) with 0, 20, 40, and 60% Source-Separated Municipal Solid Waste (SS-MSW) compost, and dill (Anethum graveolens L.) and peppermint (Mentha X piperita L.) were amended with 0, 20, 40, and 60% of high-Cu manure compost (by volume). The SS-MSW compost applications increased the concentration of Cu and Zn in all fractions, increased Mn in acid extractable (ACID), iron and manganese oxides (FeMnOX), and organic matter (OM) fractions, but decreased slightly exchangeable-Mn. Addition of 60% high-Cu manure compost to the soil increased Cu EXCH, ACID, FeMnOX, and OM fractions, but decreased EXCH-Mn, and did not change EXCH-Zn. Addition of both composts to soil reduced bioavailability and transfer factors for Cu and Zn. Our results ...

2004-09-01

428

Pa0148 from Pseudomonas aeruginosa Catalyzes the Deamination of Adenine.

Zinc molybdate (ZnMoO4) single crystals were grown for the first time by the Czochralski method and their luminescence was measured under X ray excitation in the temperature range 85-400 K. Properties of ZnMoO4 crystal as cryogenic low temperature scintillator were checked for the first time. Radioactive contamination of the ZnMoO4 crystal was estimated as <0.3 mBq/kg (228-Th) and 8 mBq/kg (226-Ra). Thanks to the simultaneous measurement of the scintillation light and the phonon signal, the alpha particles can be discriminated from the gamma/beta interactions, making this compound extremely promising for the search of neutrinoless Double Beta Decay of 100-Mo. We also report on the ability to discriminate the alpha-induced background without the light measurement, thanks to a different shape of the thermal signal that characterizes gamma/beta and alpha particle interactions.

2010-01-01

429

Organic against inorganic electrodes grown onto polymer substrates for flexible organic electronics applications

Four proteins from NCBI cog1816, previously annotated as adenosine deaminases, have been subjected to structural and functional characterization. Pa0148 (Pseudomonas aeruginosa PAO1), AAur1117 (Arthrobacter aurescens TC1), Sgx9403e, and Sgx9403g have been purified and their substrate profiles determined. Adenosine is not a substrate for any of these enzymes. All of these proteins will deaminate adenine to produce hypoxanthine with k(cat)/K(m) values that exceed 10(5) M(-1) s(-1). These enzymes will also accept 6-chloropurine, 6-methoxypurine, N-6-methyladenine, and 2,6-diaminopurine as alternate substrates. X-ray structures of Pa0148 and AAur1117 have been determined and reveal nearly identical distorted (?/?)(8) barrels with a single zinc ion that is characteristic of members of the amidohydrolase superfamily. Structures of Pa0148 with adenine, 6-chloropurine, and hypoxanthine were also determined, thereby permitting identification of the residues responsible for ...

2011-07-06

430

One of the most challenging topics in the area of organic electronic devices is the growth of transparent electrodes onto flexible polymeric substrates that will be characterized by enhanced conductivity in combination with high optical transparency. An essential aspect for these materials is their synthesis and/or microstructure which define the transparency, the stability and the interfacial chemistry which in turn determine the performance and stability of the organic electronic devices, such as organic light emitting diodes, organic photovoltaics, etc. In this work, we will discuss the latest advances in the growth of organic (e.g. PEDOT:PSS) and inorganic (e.g. zinc oxide-ZnO, indium tin oxide-ITO) conductive materials and their deposition onto flexible polymeric substrates. We will compare the optical, structural, nano-mechanical and nano-topographical properties of the inorganic and organic materials and we investigate the effect of their structure on their ...

2009-12-15

431

Nitrosamines and rubber

Micronutrient nutrition of rice in flooded soils

Occupational exposure to N-nitrosamines in the rubber industry was first reported by Fajen et al. (1979). In order to study the origin and formation of nitrosamines in this industry, chemicals and industrial products, as well as the air in various working areas, were analysed. All chemicals used for rubber compounding contain nitrosamines if they are derivatives of secondary amines; e.g., tetramethylthiurame, zinc-diethyldithiocarbamate or N-oxydiethylene benzothiazolylsulfenamide. All rubber products containing these dialkyl amine derivatives exhibited considerable levels of the corresponding nitrosamines. Accordingly, variable concentrations of airborne nitrosamines could be detected at places where rubber products are manufactured or stored. The nitrosamines found correspond to the compounded chemicals. The original nitrosamine level in rubber chemicals is not high enough to explain the amounts found in rubber products and in air, so that additional nitrosation ...

1982-01-01

432

Metal leaching and acid mine drainage in British Columbia; La lixiviation des metaux et le drainage acide en Colombie-Britannique

Micronutrient deficiencies in flooded rice have been recognized with increasing frequency in recent years. Zinc deficiency is the most widespread disorder, followed by Fe, Mn, and Cu deficiencies. Boron and Mo deficiencies have not been reported in field culture. The peculiar characteristics of a flooded soil are: 1) a layer of standing water; 2) absence of oxygen; 3) a soil profile largely in a reduced chemical state; 4) the presence of large biological carbon dioxide excesses; 5) the presence of high concentrations of soluble Fe"+"+ and Mn"+"+; 6) alteration of soil pH; 7) the presence of toxic substances; 8) increased soluble Na"+, K"+, Ca"+"+, Mg"+"+, NH_4"+, HCO_3"-, H_2PO_4"-, and Si(OH)_4 in the soil solution. Micronutrient availability in flooded soils is affected by: 1) increased solubility of relatively insoluble minerals due to dilution effects; 2) pH changes in relation to solubility and plant availability; 3) changes in oxidation-reduction equilibria; ...

1974-09-23

433

Metal cation inhibitors for controlling denting corrosion in steam generators. Final report. [PWR

This poster presentation dealt with a brief overview of the practices in effect in British Columbia related to metal leaching and acid mine drainage. The metals mined in the province include coal, gold, silver, copper, molybdenum, lead, and zinc. Some mines operate under the surface, while others are strip mines, etc. under a variety of climactic conditions and a host of different mining companies, such as Cominco, Placer Dome and Noranda. The primary objective is the prevention of negative environmental impacts on land and in the water. Salmon and other fish need to be protected. A secondary objective is the minimization of impacts on the biota, which requires a detailed study of ecological risks. The solution often lies in soil covering. To illustrate, the author described the situation at Huckleberry Mines Ltd. and the remedial action that was implemented, and discussed the results on the beavers. In conclusion, the author discussed the strategies implemented by ...

2000-07-01

434

Mechanism of biosorption of Heavy metals by mucor rouxii

Metal cations of arsenic, antimony, tin, manganese, zinc, cadmium, indium, and thallium have been evaluated in a preliminary way as possible3 inhibitors for controlling denting corrision observed in steam generators used with pressurized water reactors (PWR). The rationale for this approach was based upon the well-known inhibition effects of metal cations on corrosion rates in electrolyte/metal systems. A review of corrosion inhibition by metal cations (H. Leidheiser, Jr., Corrosion 36, 339 (1982)) has identified eleven inhibition mechanisms. The major test methods used for this evaluation were: (1) Isothermal capsule tests of carbon/steel/Inconel 600 tube bulging rates at temperatures up to 288/sup 0/C in seawater/copper-nickel chloride bulge-accelerating solutions. (2) Immersion weight-loss tests of steel coupled to Inconel 600 in boiling (102/sup 0/C) 3% sodium chloride solutions. In addition, electrochemical measuremens and surface analyses were performed. The ...

1982-12-01

435

Measuring instrument for radiometric monitoring of solids and heavy metals in water

Fungi such as Aspergillus niger and Mucor rouxii are capable of removing heavy metals from aqueous solutions. The role various functional groups play in the cell wall of M. rouxii in metal biosorption of lead, cadmium, nickel and zinc was investigated in this paper. The biomass was chemically treated to modify the functional carboxyl, amino and phosphate groups. These modifications were examined by means of infrared spectroscopy. It was found that an esterification of the carboxyl groups and phosphate and a methylation of the amine groups significantly decreased the biosorption of the heavy metals studied. Thus, the carboxylate, amine and phosphate groups were recognized as important in the biosorption of metal ions by M. rouxii biomass. The role the lipids fraction play was not significant. The study showed that Na, K, Ca and Mg ions were released from the biomass after biosorption of Pb,Cd,Ni and Zn, indicating that ion exchange was a key mechanism in the ...

2008-08-15

436

Measuring characteristics on emissivity using infrared thermometer for RCCS

A combination of measuring instruments, consisting of a Beta-Sedimeter and a radionuclide X-ray fluorescence instrument, is described. With the Beta-Sedimeter the C-14-radiation is measured. Through direct irradiation with photons of a Pu238-source in an ancillary irradiation chamber and energy dispersing measurement of the K- and L-radiation resp. of the excited heavy metals with the aid of a Si(Li)-semiconductor detector and a 4-channel analyzer the heavy metal concentrations of the heavy metals Zn, Cr, Ni and Pb are determined. For the determination of cadmium the indirect excitation with Am-241 and Dy-targets is described. The system produces records and operates fully automatically in a step-by-step mode with a testing cycle of 45 minutes. In connection with the process monitoring of the wastewater from a zinc plating plant during a period of 8 months the concentration of the solid material and of the metals Cr and Zn, which were considered to be ...

1979-01-01

437

High-temperature recycling of contaminated scrap and residual materials in multipurpose oxygen cupola furnaces; Hochtemperatur-Recycling von verunreinigtem Schrott und Reststoffen im Mehrzweck-Sauerstoff-Kupolofen

In VHTGR (Very High Temperature Gas-cooled Reactor), the radiation plays an important role in heat transfer through the cavity in RCCS (Reactor Cavity Cooling System). We performed the series of experiments to measure the emissivity using the infrared thermometer with wavelength range of 8#approx#14 #mu#m. As the first step, the transmittance of Zinc Selenide (ZnSe) window was measured to estimate the emissivity that can compensate the attenuation effect of window. The kind of gas with various concentrations in the cavity will be released during postulated accidents to the coolant type, so it is essential to estimate the effects of gas on the measurement of emissivity. In this manner we measured the emissivity with the air, the helium and the steam inside chamber. The results represent that the concentration of the air and the helium do not affect the emissivity significantly while the steam decreases the measured emissivity relatively. It means that the air and ...

2004-12-01

438

Heavy metals in Semarang`s urban streams: Spatial distribution and bioindication using the guppy (Lepistes reticulatus)

The new multi-purpose oxygen cupola furnace is a coke-fired shaft furnace that is operated on pure oxygen. The top gas is recirculated, and the fumes are drawn off at temperatures ranging from 800 to 1 000 C. The furnace offers the possibility of melting down contaminated and zinc-bearing scrap without the occurrence of any environment-polluting gas emissions. The absence of nitrogen ballast permits a high energy efficiency. (orig.) [Deutsch] Der neue Mehrzweck-Sauerstoff-Kupolofen ist ein koksbeheizter Schachtofen, der mit reinem Sauerstoff betrieben wird. Das Gichtgas wird im Kreislauf gefuehrt, und das Abgas wird aus einem Bereich mit Temperaturen von 800 bis 1 000 C abgefuehrt. Der Ofen bietet die Moeglichkeit, verunreinigte und zinkhaltige Schrotte einzuschmelzen, ohne dass umweltbelastende Gasemissionen auftreten. Der fehlende Stickstoffbalast bewirkt einen hohen energetischen Wirkungsgrad. (orig.)

1996-07-17

439

Fuel processing equipment for fuel cell plant. Nenryo denchi plant no nenryo shori sochi

A field survey on cadmium, lead, copper, and zinc was performed in Semarang, the fifth largest city in Indonesia. Water, sediment, and fish samples were collected from 101 grids of 2 x 2 km. The objectives of the study were (1) to identify the spatial distribution of metals in the sediments of the greater Semarang area, (2) to estimate the background concentrations of the metals present in Semarang, (3) to provide a simple tool for deriving standards for metals in the sediment, and (4) to explore the potential use of the guppy (Lebistes reticulatus) as a bioindicator of urban metal pollution. To map the spatial distribution of the metals, concentrations of each metal in sediment were plotted against the corresponding city coordinate. On the basis of these plots, background concentrations of the metals were estimated. A combined pollution index can be derived thereafter by calculating the difference between metals concentrations from a particular grid and their ...

1996-12-31

440

Formation of ZnTe compounds by using the electrochemical ion exchange reaction in molten chloride

Activated charcoal which is the desulfurizing agent for the fuel cell plant can be used only at the normal temperature, and it must be placed upstream of the fuel gas, increasing the displacement flow of the fuel gas processed in the desulfurizer. In addition, a large quantity of activated charcoal must be filled or the frequency of its exchange must be increased because activated charcoal used at the normal temperature has little sulfur absorbing capacity. This invention is concerned with provision of a desulfurizer in the downstream of the fuel gas compressor of the fuel cell plant to remove sulfur content in the fuel gas by this desulfurizer. As a result, the displacement flow of the processing gas is decreased to increase the processing capacity of the desulfurizing agent. In addition, hydrogen recycling can be eliminated to realize compact arrangement of the equipment and economization of energy consumption. Metal oxide based desulfurizers of copper, iron, ...

1993-02-19

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

441

Expression profiles of PtrLOS2 encoding an enolase required for cold-responsive gene transcription from trifoliate orange

The formation of ZnTe films was investigated on zinc substrates at 640 K by using the following ion exchange and chemical reaction processes,2Zn{sub (substrate)}+Te{sup 4+}{sub (inmoltensalts)}->2Zn{sup 2+}+Te{sub (onsubstrate)}Zn{sub (substrate)}+Te= {sub (onsubstrate)}-> ZnTe{sub (onsubstrate)}The Te{sup 4+} species was supplied to the substrate via the gas phase, vaporized from the eutectic LiCl-KCl molten salt containing TeCl{sub 4} (0.05-0.9 mol%). The phase of the films obtained depended on the reaction time and the TeCl{sub 4} content in the molten chloride. At low TeCl{sub 4} concentrations, ZnTe alloy was not formed over the entire surface even after 3.6 ks. On the other hand, at high TeCl{sub 4} concentrations, tellurium was detected in addition to the ZnTe compound during the first 0.3 ks of the reaction. By selecting appropriate TeCl{sub 4} concentrations and reaction times, a ZnTe film with a smooth, dense surface was obtained. The ...

2005-05-01

442

British Library Electronic Table of Contents (United Kingdom)

Low expression of osmotically responsive genes 2 (LOS2) encodes an enolase (2-phospho-D-glycerate hydrolase, EC 4.2.1.11) that converts 2-phospho-D-glycerate (PGA) to phosphoenolpyruvate (PEP) in the glycolytic pathway in Arabidopsis. Meanwhile, it is a transcriptional activator of cold-responsive gene, negatively controlling the expression of STZ/ZAT10, a zinc finger transcriptional repressor of cold-responsive gene from Arabidopsis. A novel LOS2 gene, designated PtrLOS2 (GenBank accession number GQ144341), was isolated from trifoliate orange [Poncirus trifoliata (L.) Raf.]. The PtrLOS2 cDNA is 1 662 bp in length with a 1 338 bp open reading frame (ORF), encoding a deduced 445 amino acid residue protein with a predicted molecular mass of 47.79 kDa and an isoelectric point of 5.54. The ded...

2011-01-01

443

Evaluation of new corrosion-resistant superheater tubing in high-efficiency waste-to-energy plants

Electronic topological transition in zinc metal? A "6"7Zn-Moessbauer investigation

Field corrosion tests were conducted on eight single tube materials and two welded overlay materials in three typical Japanese waste incineration plants in an effort to develop new corrosion-resistant superheater tubes capable of functioning efficiently under temperature and pressure conditions of 500 C and 100 kgf/cm{sup 2}-g in high-efficiency waste-to-energy (WTE) plants. Austenitic alloys containing higher concentrations of chromium, nickel, and molybdenum [Cr + Ni + Mo] showed excellent corrosion-resistant properties, and the new alloys JHN24 and HR30M showed good corrosion resistance. Different corrosion rates found in each of the three plants were explained by differences in operating conditions, such as gas temperature, concentration of molten salts resulting from chlorine (Cl) content of deposits, heavy metal (zinc oxide [ZnO] + lead oxide [PbO]) content, etc. It was confirmed that the corrosion rate of materials positioned in the first tube row facing the ...

1998-07-01

444

Development of an electrically rechargeable zink/air demonstration module; Entwicklung eines elektrisch wiederaufladbaren Zink-Luft-Demonstrationsmoduls

The question concerning the existence of an electronic topological transition (ETT) in Zn metal under quasi-hydrostatic pressure at #approx#6.6 GPa caused a considerable controversy in the literature. We briefly review low-temperature "6"7Zn-Moessbauer data and scalar-relativistic augmented plane wave calculations and give a consistent interpretation in terms of an ETT. To highlight some important aspects of the controversy two theoretical and two experimental publications will be discussed in more detail. At present the existence of an ETT in Zn metal is disputed both from an experimental and from a theoretical point of view. The suggestion of a transition to a commensurate spin-density wave at #approx#6.6 GPa instead of an ETT may reconcile the seemingly contradictory results of "6"7Zn-Moessbauer experiments at 4.2 K and of room temperature inelastic neutron scattering measurements. However, it does not explain the anomalies found in theoretical calculations performed for Zn metal in ...

2000-11-01

445

Critical pitting potential of aluminium alloys. Aluminum gokin no koshoku den prime i

A team at the Paul Scherrer Institute (PSI) recently achieved a breakthrough in the development of an environment-friendly and rechargeable battery with novel electrodes. The energy storage density of a rechargeable 12 V/20 Ah zinc/air battery could be increased to 100 watt hours per kilogramme - three times as much as conventional lead accumulators. 20-Ah cells could be charged and discharged 55 times in 1000 hours without any loss of capacity worth mentioning. This is a remarkable cycle stability. (orig.) [German] Einem Team des Paul Scherrer Instituts (PSI) ist kuerzlich bei der Entwicklung einer umweltfreundlichen und wiederaufladbaren Batterie mit neuartigen Elektroden der Durchbruch gelungen. Dabei konnte die Energiespeicherdichte einer wiederaufladbaren 12 V/20 Ah-Zink-Luft-Batterie auf 100 Wattstunden pro Kilogramm gesteigert werden - dreimal soviel wie bei konventionellen Bleiakkumulatoren. 20-Ah-Zellen konnten in 1000 Stunden ohne nennenswerte ...

1999-10-01

446

Copper and brass aged at open circuit potential in slightly alkaline solutions

Pitting corrosion measuring method for almunum alloys sold on the market was studied. By addition of a little quantity of Cu {sup ++} ion, corrosion potential of alminum alloys rapidly approachs to pitting corrosion potential in the solution including chloride. After Cu {sup ++} ion of 5ppm is added in advance into the solution including chrolide to measure the pitting corrosion potential, alminum alloy test pieces are imersed into the solution in the atmospheric air, then the stable corrosion potential is shown after three-minite imersion, and this potential is defined to the pitting corrosion potential. The pitting corrosion potential can be easily measured by this method stated above (copper ion method). The values measured by copper ion method is comparatively agreed with that measured by the existing potentio dynamic method. The pitting corrosion potential have a straight lined relation with the logarithm of Cl {sup -} concentration. As the measured values by potentio dynamic ...

1990-02-15

447

Chemical imaging of wood-polypropylene composites.

Surface oxide films were grown on 99.99% copper and brass (copper-zinc alloy, Cu77Zn21Al2) in 0.1 mol L{sup -1} borax solution at open circuit potential and were characterized using various experimental techniques. The composition of the passive films formed in situ on the different materials was studied using differential reflectance spectroscopy. The thickness of the oxide layers on copper and brass was compared by chronopotentiometric curves and potentiodynamic reductions. The electrical properties of each oxide were analyzed by means of electrochemical impedance spectroscopy. Their influence on the oxygen reduction reaction was also investigated using voltammetry hydrodynamic tools such as the rotating disk electrode. The results show that the incorporation of Zn to Cu in brass changes the composition and the thickness of the surface film. The films grown on brass tend to be thicker but less resistive and Zn compounds incorporate to the film. This is supported ...

2009-12-01

448

Briquetting of self-reducing blendings of waste iron oxide mixtures. Final report

Recent investigations of wood plastic composites have revealed a detrimental effect of using lubricant systems in production. This includes nullifying part or all of the mechanical benefit of using a polar compatibilizer, maleic anhydride polypropylene (MAPP), in the composite formulation. This investigation utilizes lubricants labeled with deuterium in conjunction with Fourier transform infrared (FT-IR) spectroscopy to allow for the separation of individual lubricants from all other material constituents. All of the deuterium labeled lubricants, used without MAPP, revealed their expulsion from the wood interface during crystallization. MAPP coupling agent was found to exist near the wood, but it is unclear if any covalent bonding with the hydroxyl functionality on the wood surface occurred. The addition of zinc stearate lubricants appears to nullify the activity of the anhydride functionality near the wood surface as evidenced by a shift in the FT-IR spectra to ...

2006-08-01

449

Biosorption of cadmium(II), zinc(II) and lead(II) by Penicillium simplicissimum: Isotherms, kinetics and thermodynamics

The objectives of this project were to develop technologies to manufacture self-reducing briquettes out of waste iron oxides and to recycle them in an electric arc furnace or a cupola furnace. CRM has investigated and determined the optimal characteristics (binder, size, grain size, compositions and activator for the reduction reaction) for briquettes containing mixtures of mill scales, mill sludges, electric arc furnace (EAF) dust and coal as reduction agent. The goal of obtaining briquettes, in which iron oxides are totally reduced when these briquettes are loaded with the scrap into an electric arc furnace, was achieved. Trials at ProfilARBED have shown that it is possible to recycle mill and EAF by-products conditioned in self-reducing briquettes in an electric arc furnace without influence on the performance and on the environment. The iron content of the slag does not increase as the iron of the by-product is almost completely reduced. Zinc is completely ...

2002-07-01

450

Bi-functional oxygen electrodes using Pr-Mn-Fe-based perovskite-type oxides as catalysts

The isotherms, kinetics and thermodynamics of Cd(II), Zn(II) and Pb(II) biosorption by Penicillium simplicissimum were investigated in a batch system. The effects of pH, initial metal ions concentration, biomass dose, contact time, temperature and co-ions on the biosorption were studied. Adsorption data were well described by both the Redlich-Peterson and Langmuir model. Chemical ion-exchange was found to be an important process based on free energy value from Dubini-Radushkevich isotherm for all metal ions. The results of the kinetic studies of all metal ions at different temperature showed that the rate of adsorption followed the pseudo second-order kinetics well. The thermodynamics constants {delta}G{sup o}, {delta}H{sup o} and {delta}S{sup o} of the adsorption process showed that biosorption of Cd(II), Zn(II) and Pb(II) ions on Penicillium simplicissimum were endothermic and spontaneous.

2008-12-30

451

Behavior at under-film corrosion tips of Zn-Fe alloy coated steel sheets. Zn-Fe gokin mekki koban no tomakushita fushoku ni okeru fushoku sentanbu no kyodo

To develop oxygen electrodes for rechargeable metal-air batteries, the electrochemical behaviour of gas-diffusion-type carbon electrodes loaded with Pr-Mn-Fe-based perovskite-type oxides was examined for the reduction and evolution of oxygen in 8 M KOH at 60 C. Among the oxides tested, Pr{sub 0.2}Ca{sub 0.8}Mn{sub 0.1}Fe{sub 0.9}O{sub 3} gave the highest electrode performances, e.g., current densities of 275 mA/cm{sup 2} (for oxygen reduction) and 225 mA/cm{sup 2} (for oxygen evolution) at -300 and +650 mV vs. Hg/HgO, respectively. The electrode performances were found to depend on both the catalytic activity of the oxides for H{sub 2}O{sub 2} decomposition reaction and the amounts of oxygen desorbed from the oxides. Furthermore, it was confirmed that the small zinc-air battery including the gas-diffusion-type electrode loaded with Pr{sub 0.2}Ca{sub 0.8}Mn{sub 0.1}Fe{sub 0.9}O{sub 3} showed good discharge and charge characteristics. (orig.)

1999-07-01

452

Band parameters for III - V compound semiconductors and their alloys

From a macroscopic point of view, corrosion of Zn alloy coated steel sheet occurs by the coating preceding corrosion mechanism; microscopically, however, the coated layer corrosion velocity in the tip of corrosion is different. In order to find the main factors of under-film corrosion of Zn and Zn-Fe alloy coatings in the salt water spray atmospheric exposure test, the correlation between point inflation-exfoliation width and chlorine penetration behavior, point adhesion, and the difference in chlorine penetration behavior due to alloy coating components were investigated. Consequently, the following results were obtained: 1. The better correlation was observed between chlorine penetration distance and point inflation-point exfoliation width. 2. The durability of coating against chlorine penetration improved by increase in point adhesion and Zn content in the coating layer. 3. Zn-Fe (10-20%) alloy coating showed better durability against chlorine penetration than pure Zn coating. 4. ...

1990-09-01

453

BNFL Report Glass Formers Characterization

We present a comprehensive, up-to-date compilation of band parameters for the technologically important III - V zinc blende and wurtzite compound semiconductors: GaAs, GaSb, GaP, GaN, AlAs, AlSb, AlP, AlN, InAs, InSb, InP, and InN, along with their ternary and quaternary alloys. Based on a review of the existing literature, complete and consistent parameter sets are given for all materials. Emphasizing the quantities required for band structure calculations, we tabulate the direct and indirect energy gaps, spin-orbit, and crystal-field splittings, alloy bowing parameters, effective masses for electrons, heavy, light, and split-off holes, Luttinger parameters, interband momentum matrix elements, and deformation potentials, including temperature and alloy-composition dependences where available. Heterostructure band offsets are also given, on an absolute scale that allows any material to be aligned relative to any other. [copyright] 2001 American Institute of ...

2001-06-01

454

Assessment of the historical trace metal contamination of sediments in the Elizabeth River, Virginia

The objective of this task was to obtain powder property data on candidate glass former materials, sufficient to guide conceptual design and estimate the cost of glass former handling facilities as requested under Part B1 of BNFL Technical and Development Support. Twenty-nine glass forming materials were selected and obtained from vendors for the characterization of their physical properties, durability in caustic solution, and powder flow characteristics. A glass former was selected based on the characterization for each of the ten oxide classes required for Envelope A, B, and C mixtures. Three blends (A, B, and C) were prepared based on formulations provided by Vitreous State Laboratory and evaluated with the same methods employed for the glass formers. The properties obtained are presented in a series of attached Tables. It was determined that five of the ten glass formers, (kyanite, iron oxide, titania, zircon, and zinc oxide) have the potential to cause some ...

2000-07-27

455

Apoferritin Templated Synthesis of Metal Phosphate Nanoparticle Labels for Electrochemical Immunoassay

Two sediment cores (Southern Branch, PC-1, and Western Branch, WB-2) were taken from the highly industrialized Elizabeth River, Virginia. The concentrations of trace metals cadmium, cobalt, chromium, copper, nickel, lead and zinc, major elements iron, manganese and aluminum, organic carbon content and the specific surface area of the sediments were determined in each of the cores. Down-core variations in metals varied significantly in each core with maximum contamination events occurring at different times in different portions of the river. In PC-1, maximum metal concentrations were seen after the appearance of "1"3"7Cs. In contrast, the highest levels in WB-2 occurred well before the appearance of "1"3"7Cs. Although stricter environmental regulations have caused a decrease in metal concentrations since the 1980s, the concentrations in the surface sediments of many trace metals were elevated to levels 2-5 times higher than the levels at the bottom of the cores in ...

2007-04-01

456

Surface modification, organometallic and polyaryl polymer coatings, and flame spray technologies for preventing corrosion of metals. Final report

W have introduced template-synthesized metal phosphate nanoparticle labels for electrochemical immunoassay. Such use of an apoferritin template offers a simple and convenient route to prepare metallic nanoparticle labels for electrochemical immunoassays and avoid the complicated and time-consuming nanoparticle synthesis process (QD synthesis). Releasing metal ions from metal phosphate in an acetate buffer (pH 4.6) eliminates the harsh condition in the traditional metallic nanoparticle dissolution (e.g., strong acid dissolution of QDs and gold nanoparticles). This method is ultrasensitive and its DL is low to 77fM. The simultaneous detection of multiple protein targets is easily performed by using different metal phosphate nanoparticle labels (cadmium phosphate and lead phosphate). This approach can be extended to prepare multiple metal (such as zinc, lead, cadmium, copper, indium, gold, silver) phosphate nanoparticle labels or hybrid metal (bimetallic or ...

2006-08-29

457

'Zoxy' - the zinc-air high energy battery system: with decentral charging infrastructure; ''Zoxy'' - das Zink-Luft-Hochenergiebatterie-System mit dezentraler Lade-Infrastruktur

To improve adherent properties of electrogalvanized steel (EGS) to polymeric topcoats, the surfaces of EGS were modified by polyelectrolyte-modified zinc phosphating solution. The electrochemical reaction between phosphating solution and EGS led to the complete coverage with fully grown hopeite crystals after only 5 sec treatment, thereby improving adhesion to topcoating and providing protection of EGS against corrosion. To evaluate the ability of polyphenylene sulfide (PPS) polyaryl thermoplastic coatings to protect zinc phosphate (Zn{center_dot}Ph)treated steels from corrosion in a wet, harsh environment ( 1.0 wt % H{sub 2}SO{sub 4}, 3.0 wt % NaCl and 96.0 wt % water at temperatures from 25{degrees} to 200{degree}C), we exposed them in an autoclave to attempt heating-cooling cyclic fatigue tests (1 cycle = 12 hr at 200{degrees}C + 12 hr at 25{degrees}C) up to 90 times. The major chemical reaction at the interface between the PPS and Zn in the ...

1995-07-01

458

Yield-increasing additives in kraft pulping: Effect on carbohydrate retention, composition and handsheet properties

Storing electrical energy in batteries is not a viable option for sustaining a country's energy economy. The mass and volume, as well as the costs, of electrochemical components required for this would be beyond all reason. Nevertheless, in certain applications the storage of electrical energy does have significant advantages over other technologies. For example, electrically powered road vehicles emit no exhaust fumes and very little noise at their place of operation. In this way they contribute substantially to air and noise pollution control in urban areas. Photovoltaic applications permit environmentally friendly electricity applications in places remote from the public grid where conventional solutions are prohibitively expensive. More than in the past, battery systems today have to meet a wide range of technical, economic and ecological requirements in order to be marketable. This is why the ''Zoxy'' zinc-air ...

1997-02-01

459

Paul Scherrer Institut Scientific Report 2001. Volume V: General Energy

In this thesis, increased hemicellulose retention during kraft pulping has been studied. The work has been divided into three parts: i) Development of an accessible and reliable method for determination of carbohydrate composition of kraft pulps ii) Investigation of the composition and molecular mass distributions of the carbohydrates in kraft pulps with increased hemicellulose content iii) Investigation of the effect of increased hemicellulose content on the sheet properties of kraft pulps with increased hemicellulose content. A method for carbohydrate determination was developed. In this method, enzymes are used to hydrolyse the pulp into monosaccharides. A relatively mild acid hydrolysis is performed prior to detection on an HPLC with an RI-detector. The pulp is not derivatized and no pre-treatment (mechanical or chemical) is needed to determine the carbohydrate composition using the method developed here. Peak deconvolution software is used to improve the accuracy. Polysulphide and ...

2008-07-01

460

Review of Constructed Subsurface Flow vs. Surface Flow Wetlands

Major advances in 'Energy and Materials Cycles' have been achieved in the removal of heavy metals from the solid residues of municipal waste incineration. It has been conclusively shown that the oxidation/reduction conditions established during the thermal treatment of filter ash have a decisive influence on the evaporation of groups of heavy metals. With respect to biomass gasification, studies have been carried out with respect to the best way of extracting pure hydrogen from the low calorific value gas that is typically obtained from a biomass gasifier. The overarching goal of the laboratory 'High Temperature Solar Technology' is the use of solar energy for the production of solar fuels, or for the reduction of CO{sub 2} emissions in large scale industrial processes that are conventionally carried out with the use of fossil fuels. In a short-term project targeted at the solar production of lime, highly encouraging results (98% degree of ...

2002-03-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

461

Zinc/air battery R and D research and development of bifunctional oxygen electrode: Tasks I and II, Final report

The purpose of this document is to use existing documentation to review the effectiveness of subsurface flow and surface flow constructed wetlands in treating wastewater and to demonstrate the viability of treating effluent from Savannah River Site outfalls H-02 and H-04 with a subsurface flow constructed wetland to lower copper, lead and zinc concentrations to within National Pollutant Discharge Elimination System (NPDES) Permit limits. Constructed treatment wetlands are engineered systems that have been designed and constructed to use the natural functions of wetlands for wastewater treatment. Constructed wetlands have significantly lower total lifetime costs and often lower capital costs than conventional treatment systems. The two main types of constructed wetlands are surface flow and subsurface flow. In surface flow constructed wetlands, water flows above ground. Subsurface flow constructed wetlands are designed to keep the water level below the top of the ...

2004-09-01

462

Virostatic potential of micro-nano filopodia-like ZnO structures against herpes simplex virus-1.

Studies were conducted of the bifunctional oxygen electrode. The development of a rechargeable metal-oxygen (air) cell has been hampered to a great extent by the lack of a stable and cost effective oxygen electrode capable of use during both charge and discharge. The first type of bifunctional electrode consists of two distinct catalytifc layers. The oxygen reduction catalyst layer containing a supported gold catalyst is in contact with a hydrophilic nickel layer in which evolution of oxygen takes place. Loadings of gold from 0.5 to 1.0 mg/cm/sup 2/ were investigated; carbon, graphite, metal, and spinel oxides were evaluated as substrates. The second part of the research effort was centered on developing a reversible oxygen electrode containing only one catalytic layer for both reduction and evolution of oxygen. The work was directed specifically to the study of perovskite type of oxides with the composition AA/sup 1/BO/sub 3/ where A is an element of the lanthanide series, A/sup 1/ is ...

1986-12-01

463

Use of man-made impoundment in mitigating acid mine drainage in the North Branch Potomac River

Herpes simplex virus type-1 (HSV-1) entry into target cell is initiated by the ionic interactions between positively charged viral envelop glycoproteins and a negatively charged cell surface heparan sulfate (HS). This first step involves the induction of HS-rich filopodia-like structures on the cell surface that facilitate viral transport during cell entry. Targeting this initial first step in HSV-1 pathogenesis, we generated different zinc oxide (ZnO) micro-nano structures (MNSs) that were capped with multiple nanoscopic spikes mimicking cell induced filopodia. These MNSs were predicted to target the virus to compete for its binding to cellular HS through their partially negatively charged oxygen vacancies on their nanoscopic spikes, to affect viral entry and subsequent spread. Our results demonstrate that the partially negatively charged ZnO-MNSs efficiently trap the virions via a novel virostatic mechanism rendering them unable to enter into human corneal ...

2011-08-26

464

The development of emissions of heavy metals in the Federal Republic of Germany from 1985 to 1995; Die Entwicklung der Schwermetallemissionen in der Bundesrepublik Deutschland von 1985 bis 1995

The US Department of the Army, Baltimore District Corps of Engineers, oversees a long-term monitoring study to assess and evaluate effects of the Jennings-Randolph reservoir on biota in the North Branch Potomac River. The reservoir was intended, in part, to mitigate effects of acid mine drainage originating in upstream and headwater area. The present study assessed recovery of benthos and fish in this system, six years after completion of the reservoir. Higher pH and lower iron and sulfate concentrations were observed upstream of the reservoir compared to preimpoundment conditions, suggesting better overall water quality in the upper North Branch. Water quality improved slightly directly downstream of the reservoir. However, the reservoir itself was poorly colonized by macrophytes and benthic organisms, and plankton composition suggested either metal toxicity and/or nutrient limitation. One large tributary to the North Branch and the reservoir (Stony River) was shown to have high (and ...

465

The coal mining industry in the north of Colorado and Arizona; Steinkohlenbergbau im Norden Colorados und Arizonas

Emission inventories were estimated for the airborne emissions of: Arsenic, Beryllium, Cadmium, Chromium, Cobalt, Copper, Mercury, Manganese, Molybdenum, Nickel, Lead, Antimony, Selenium, Tellur, Thallium, Zinc, Platinum, Palladium, Rhodium, Tin. The inventories were made for the status of 1985 and 1990. A prognosis was given for 1995. The investigations were made for the whole area of the Federal Republic of Germany including the former German Democratic Republic. Working point was an overview about the plant-specific emissions for the various industrial branches and the production statistics. The results are given as total emissions from the existing plants and industrial branches. (orig.) [Deutsch] Es erfolgte eine Abschaetzung der luftseitigen Emissionen fuer die Elemente: Arsen, Beryllium, Cadmium, Chrom, Kobalt, Kupfer, Quecksilber, Mangan, Molybdaen, Nickel, Blei, Antimon, Selen, Tellur, Thallium, Zink, Platin, Palladium, Rhodium und Zink. Die Erhebungen ...

1995-03-01

466

Technology base research on zinc/air battery systems: Final report

A study tour in autumn 1999, which was undertaken following the award of the Helmuth Burkhardt prize of Wirtschaftsvereinigung Bergbau e.V. to the authors, comprised visits to potash, molybdenum, lead, zinc, copper ore and coal mines in the mid-west of the USA. The Black Mesa Mine and Kayenta Mine of Peabody Western Coal Company in the Navajo Reserve in the north of Arizona, the Trapper Mine Inc. near Craig and the Twentymile Coal Company near Steamboat Springs, Colorado are described in this report. In addition to a brief description of the geology the coal winning is considered in greater detail. The Twentymile Coal Company was asked to explain the reasons for the successful operation of the colliery, which produces more than 5 mill. t anthracite per year by long wall working. (orig.) [German] Eine Exkursion im Herbst 1999, die durch die Verleihung des Helmuth-Burkhard-Preises der Wirtschaftsvereinigung Bergbau e.V. an Bergassessor Andreas Tschauder zustande kam, ...

2000-10-12

467

Synthesis, crystal structure, spectroscopic and photoluminescence studies of manganese(II), cobalt(II), cadmium(II), zinc(II) and copper(II) complexes with a pyrazole derived Schiff base ligand

The capacity extension of additives was tested in a 200 cm/sup 2/bi-cell and a Zn powder moving-bed slurry. It was found that for the Type A additives in 12 M KOH, 25 g/l of silicate provided higher capacity than stannate, titanate and aluminate additives. The optimum concentration of sorbitol (a Type B additive that stabilizes polymeric chains involving ZnO) was found to be 15 g/l in 12 M KOH. A silicate and sorbitol combination added to Zn powder slurry in 12 M KOH provided a 20% increase in discharge capacity (195 Ah/l at 200 A/cm/sup 2/) compared to the maximum capacity obtained with silicate alone. A much lower capacity (74 Ah/l) was realized with silicate as Type C additive (precipitation of ZnO away from the Zn surface, for low KOH concentrations). The mechanisms of passivation and capacity extension were discussed and a model presented. The cell voltage and power densities were determined for the discharge process as a function of (a) current densities, (b) cathode depolarizer ...

1987-09-01

468

British Library Electronic Table of Contents (United Kingdom)

Varying coordination modes of the Schiff base ligand H"2L [5-methyl-1-H-pyrazole-3-carboxylic acid (1-pyridin-2-yl-ethylidene)-hydrazide] towards different metal centers are reported with the syntheses and characterization of four mononuclear Mn(II), Co(II), Cd(II) and Zn(II) complexes, [Mn(H"2L)(H"2O)"2](ClO"4)"2(MeOH) (1), [Co(H"2L)(NCS)"2] (2), [Cd(H"2L)(H"2O)"2](ClO"4)"2 (3) and [Zn(H"2L)(H"2O)"2](ClO"4)"2 (4), and a binuclear Cu(II) complex, [Cu"2(L)"2](ClO"4)"2 (5). In the complexes 1-4 the neutral ligand serves as a 3N,2O donor where the pyridine ring N, two azomethine N and two carbohydrazine oxygen atoms are coordinatively active, leaving the pyrazole-N atoms inactive. In the case of complex 5, each ligand molecule behaves as a 4N,O donor utilizing the pyridine N, one azomethine N...

2011-01-01

469

Synthesis of c-axis preferred orientation ZnO:Al transparent conductive thin films using a novel solvent method

Study of ytterbium doping effects on structural, mechanical and opto-thermal properties of sprayed ZnO thin films using the Boubaker Polynomials Expansion Scheme (BPES)

Transparent aluminum doped zinc oxide (ZnO:Al, AZO) conducting thin films with a high-preferential c-axis orientation were synthesized using a new sol-gel formula. The films were deposited using a spin-coating route onto borosilicate glass substrates. We used propylene glycol methyl ether (PGME) as the solvent in place of ethylene glycol monomethyl ether (EGME), which is commonly used because it is easier to deposit onto the substrates. PGME is also superior in terms of health and safety. PGME solvent does not need to settle for several days before use and can be spin-coated as soon as the raw material and solvent are mixed. The effects of this novel solvent on the structural, morphological, electrical and optical properties are discussed using XRD, SEM, a four-point probe and UV-VIS spectrophotometry. It was found that the films produced with PGME showed a high-preferential c-axis orientation and compact microstructure in comparison films produced using EGME. The ...

2010-09-01

470

Study of ytterbium doping effects on structural, mechanical and opto-thermal properties of sprayed ZnO thin films using the Boubaker Polynomials Expansion Scheme (BPES)

In this work, ZnO thin films have been grown on glass substrates by using a solution of propanol (C{sub 3}H{sub 8}O), water (H{sub 2}O) and zinc acetate (Z{sub n}(CH{sub 3}CO{sub 2}){sub 2}) in acidified medium (pH 5). The obtained films were n doped with ytterbium (Yb) at the rates of 100, 200 and 300 ppm. The structural features of the doped films were investigated using XRD, atomic force microscopy and scanning electronic microscopy techniques. XRD analysis shows a strong (0 0 2) X-ray diffraction line for increasing Yb-doping amounts. This c-axis preferential orientation of ZnO crystallites is naturally required to use this oxide as transparent conductor in optoelectronic applications. Atomic force microscopy (AFM) analysis shows an enhancement in the surface roughness of the doped ZnO:Yb thin films. Optical measurements were performed in 300-1800 nm domain via transmittance T(lambda) and reflectance R(lambda) spectra. Conjoint optical and thermal properties ...

2009-10-19

471

Solution and particle effects on the biosorption of heavy metals by seaweed biomass

In this work, ZnO thin films have been grown on glass substrates by using a solution of propanol (C3H8O), water (H2O) and zinc acetate (Zn(CH3CO2)2) in acidified medium (pH 5). The obtained films were n doped with ytterbium (Yb) at the rates of 100, 200 and 300 ppm. The structural features of the doped films were investigated using XRD, atomic force microscopy and scanning electronic microscopy techniques. XRD analysis shows a strong (0 0 2) X-ray diffraction line for increasing Yb-doping amounts. This c-axis preferential orientation of ZnO crystallites is naturally required to use this oxide as transparent conductor in optoelectronic applications. Atomic force microscopy (AFM) analysis shows an enhancement in the surface roughness of the doped ZnO:Yb thin films. Optical measurements were performed in 300-1800 nm domain via transmittance T(?) and reflectance R(?) spectra. Conjoint optical and thermal properties were deduced from the optical measurements in ...

2009-10-19

472

Quasiparticle band structure of thirteen semiconductors and insulators

Biosorption of cadmium (Cd), cobalt (Co), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) by six fractions of particle sizes, ranging from 0.063 to 1.4 mm of dry marine algal biomass of Sargassum fluitans and Ascophyllum nodosum, is examined. Equilibrium metal uptake by larger particles was higher than that by smaller particles in the order of Pb > Cd > Cu > Co > Zn > Ni for both biomass types, with S. fluitans sorbing slightly more than A. nodosum. Uptakes of metals ranged from the highest, q{sub max} = 369 mg Pb/g (particle size 0.84-1.00 mm), to the low Zn and Ni uptakes, q{sub max} = 77 mg/g (size 0.84-1.00 mm) for S. fluitans. A. nodosum adsorbed metals in the range from q{sub max} = 287 mg Pg/g (particle size 0.84-1.00 mm) to q{sub max} = 73 mg Zn/g (particle size 0.84-1.00mm). Harder stipe fractions of S. fluitans demonstrated generally higher metal uptakes than the softer fractions derived from its blades (leaves). The pH dependence of the ...

1996-12-01

473

Quasiparticle band structure of thirteen semiconductors and insulators

By using a model dielectric matrix in electron self-energy evaluations the computational effort of a quasiparticle band-structure calculation for a semiconductor is greatly reduced. Applications to various systems with or without inversion symmetry, having narrow or wide band gaps, and semiconductor alloys demonstrate the reliability and accuracy of the method. Calculations have been performed for thirteen semiconducting or insulating materials: Si, LiCl, AlP, AlAs, AlSb, GaP, GaAs, GaSb, InP, InAs, InSb, and the Al{sub 0.5}Ga{sub 0.5}As and In{sub 0.53}Ga{sub 0.47}As alloys. Excellent agreement with experimental results is obtained for the quasiparticle energies for these materials. The only three exceptions, {ital E}({Gamma}{sub 1{ital c}}) of AlP, {ital E}({ital L}{sub 1{ital c}}) of AlAs, and {ital E}({ital L}{sub 1{ital c}}) of AlSb are discussed and attributed to various experimental uncertainties. Several other quasiparticle-excitation-related properties are also examined in ...

1991-06-15

474

Numerical Modeling of Reactive Multiphase Flow for FCC and Hot Gas Desulfurization Circulating Fluidized Beds

By using a model dielectric matrix in electron self-energy evaluations the computational effort of a quasiparticle band-structure calculation for a semiconductor is greatly reduced. Applications to various systems with or without inversion symmetry, having narrow or wide band gaps, and semiconductor alloys demonstrate the reliability and accuracy of the method. Calculations have been performed for thirteen semiconducting or insulating materials: Si, LiCl, AlP, AlAs, AlSb, GaP, GaAs, GaSb, InP, InAs, InSb, and the Al_0_._5Ga_0_._5As and In_0_._5_3Ga_0_._4_7As alloys. Excellent agreement with experimental results is obtained for the quasiparticle energies for these materials. The only three exceptions, E(#GAMMA#_1_c) of AlP, E(L_1_c) of AlAs, and E(L_1_c) of AlSb are discussed and attributed to various experimental uncertainties. Several other quasiparticle-excitation-related properties are also examined in this work. The many-body corrections to the eigenvalues of the ...

475

Molecular mechanisms of the epithelial transport of toxic metal ions, particularly mercury, cadmium, lead, arsenic, zinc, and copper. Progress report, January 1, 1979-December 31, 1979

This work was carried out to understand the behavior of the solid and gas phases in a CFB riser. Only the riser is modeled as a straight pipe. A model with linear algebraic approximation to solids viscosity of the form, {musubs} = 5.34{epsisubs}, ({espisubs} is the solids volume fraction) with an appropriate boundary condition at the wall obtained by approximate momentum balance solution at the wall to acount for the solids recirculation is tested against experimental results. The work done was to predict the flow patterns in the CFB risers from available experimental data, including data from a 7.5-cm-ID CFB riser at the Illinois Institute of Technology and data from a 20.0-cm-ID CFB riser at the Particulate Solid Research, Inc., facility. This research aims at modeling the removal of hydrogen sulfide from hot coal gas using zinc oxide as the sorbent in a circulating fluidized bed and in the process indentifying the parameters that affect the performance of the ...

2005-07-01

476

Molecular cloning of chicken metallothionein. Deduction of the complete amino acid sequence and analysis of expression using cloned cDNA

The mechanism of lead transport is presented, and especially the particular similarities or dissimilarities between lead and calcium in this process. The absorption of these metals was determined cockerels, raised on a commercial diet or on a specified diet, using in vivo ligated loop procedure. The dose administered into the loop contained 0.5 #mu#Ci "2"0"3Pb (and/or 0.1 #mu#Ci "4"7Ca), and 0.01 mM lead acetate (and/or mM CaCl_2) in 0.5 ml 0.15 M NaCl,pH 6.5. It was shown that lead is rapidly taken up by the mucosal tissue, and slowly transferred into the body, whereas less calcium is retained by the tissue and the transfer of calcium is many times as effective as that for lead. They appear to respond in a similar manner to a low calcium intake and vitamin D treatment. Increasing luminal stable lead concentration significantly reduced the percentage of radiolead significantly reduced the percentage of radiolead absorbed, but did not affect the absorption of calcium. Also, vitamin D ...

477

Layered PrBaCo_2O_5_+_#delta# perovskite as a cathode for proton-conducting solid oxide fuel cells

A cDNA library was constructed using RNA isolated from the livers of chickens which had been treated with zinc. This library was screened with a RNA probe complementary to mouse metallothionein-I (MT), and eight chicken MT cDNA clones were obtained. All of the cDNA clones contained nucleotide sequences homologous to regions of the longest (375 bp) cDNA clone. The latter contained an open reading frame of 189 bp, and the deduced amino acid sequence indicates a protein of 63 amino acids of which 20 are cysteine residues. Amino acid composition and partial amino acid sequence analyses of purified chicken MT protein agreed with the amino acid composition and sequence deduced from the cloned cDNA. Amino acid sequence comparison establish that chicken MT shares extensive homology with mammalian MTs. Southern blot analysis of chicken DNA indicates that the chicken MT gene is not a part of a large family of related sequences, but rather is likely to be a unique gene ...

1988-01-25

478

Layered GdBa_0_._5Sr_0_._5Co_2O_5_+_#delta# as a cathode for proton-conducting solid oxide fuel cells with stable BaCe_0_._5Zr_0_._3Y_0_._1_6Zn_0_._0_4O_3_-_#delta# electrolyte

The layered PrBaCo_2O_5_+_#delta# (PBCO) perovskite oxides were synthesized by modified Pechini method and investigated as a cathode material for solid oxide fuel cells (SOFCs) based on a stable and easily sintered perovskite oxide BaCe_0_._5Zr_0_._3Y_0_._1_6Zn_0_._0_4O_3_-_#delta# (BCZYZ) as electrolyte. The fabricated single cell of NiO-BCZYZ/BCZYZ (#approx#20 #mu#m)/PBCO was operated from 550 to 700 "oC with humidified hydrogen (#approx#5% H_2O) as fuel and the static air as oxidant. The BCZYZ perovskite electrolyte was completely dense after sintered at 1250 "oC for 5 h, lower than that without zinc dopant about 150 "oC. A high open-circuit potential of 1.007 V, a peak power density of 361 mW cm"-"2, and a low polarization resistance of the electrodes of 0.12 #OMEGA# cm"2 was achieved at 700 "oC. The ratio of polarization resistance to total cell resistance decreased with the increase of operating temperature, from 54.2% at 550 "oC to 17.9% at 700 "oC, ...

2010-04-02

479

Isotope aided studies of the bioavailability of iron and zinc from human diets consumed in Venezuela

The layered GdBa_0_._5Sr_0_._5Co_2O_5_+_#delta# (GBSC) perovskite oxides are synthesized by modified Pechini method and investigated as a novel cathode material for solid oxide fuel cells (SOFCs) based on a stable perovskite oxide BaCe_0_._5Zr_0_._3Y_0_._1_6Zn_0_._0_4O_3_-_#delta# (BCZYZ) as electrolyte. The fabricated single cells of NiO-BCZYZ/BCZYZ (#approx#20 #mu#m)/GBSC (#approx#20 #mu#m) were operated from 550 to 700 "oC with humidified hydrogen (#approx#5% H_2O) as fuel. The BCZYZ perovskite electrolyte was completely dense after sintered at 1250 "oC for 5 h, lower than that without zinc dopant about 150 "oC. An open circuit voltage of 1.009 V and a maximal power density of 0.35 W cm"-"2 were achieved at 700 "oC. The interfacial polarization resistance was as low as 1.46, 0.45, 0.25 and 0.15 #OMEGA# cm"2 at 550, 600, 650 and 700 "oC, respectively. The ratio of polarization resistance to total cell resistance decreased with the increase in the operating ...

2010-04-30

480

Health-hazard evaluation report HETA 88-108-2146, Asarco New Market/Young Mines, Mascot, Tennessee

Previous studies on Venezuelan diets provided information on food consumed in each diet and their nutritional contents. It also showed the comparison of the iron absorption from these diets when given in the morning after over-night fast and when given at the customary time of the day. It was observed that the iron absorption from the lunch given at noon was slightly higher (although not significant) in Zulia and Sucre diets. There were no significant differences between the Zulia lunch given in the morning after over-night fast at noon. Similar results were observed in the Sucre diet lunch repeated twice. From these results we can state that iron absorption from meals is not affected by the time it is administered with the condition that the subjects tested have had a previous fast of three hours before the meal is administered. The significant difference in iron absorption in the first study could be due to a marked physiological daily variation in iron absorption. The results from ...

1992-11-16

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481

Fuel cell program - Overview reports 2007; Programm Brennstoffzellen inkl. Wasserstoff - Ueberblicksberichte der BFE-Programmleiter 2007

In response to a request from the International Chemical Workers Union, Akron, Ohio, an investigation was made into possible hazardous working conditions at two American Smelting and Refining Company (SIC-1031) zinc mines (New Market and Young) in Mascot, Tennessee. Specifically, exposures to asbestos (1332214), silica (14808607), and diesel emissions were determined. At both mines overexposures were found to nitrogen-dioxide (10102440) (NO2) and coal-tar pitch volatiles. Twenty-four percent of the NO2 measurements taken were above the NIOSH recommended ceiling of 1 part per million (ppm), but none exceeded the Mine Safety and Health Administration's (MSHA) ceiling of 5ppm. Exposure to diesel particulates ranged from 0.24 to 1.06mg/cu m. None of the 52 respirable dust samples collected exceeded the calculated MSHA limits for free silica exposure. A medical evaluation was offered and 83 of the 400 current employees and one retired employee participated. ...

1991-10-01

482

F-Area Seepage Basins groundwater monitoring report -- third and fourth quarters 1993. Volume 1

This report for the Swiss Federal Office of Energy (SFOE) presents the overview reports made by SFOE Heads of Program on work done in 2007. Projects reported on in the natural gas-fired fuel cell area include the EU-project REAL-SFOC, the long-term testing of anode-supported SOFC stacks, intermediate-temperature fuel cells based on proton conducting electrolytes, the interdisciplinary ONEBAT project and lifetime-enhancement of SOFC stacks for CHP applications. In the polymer-electrolyte fuel cell (PEFC) area, projects concerning proton-conducting polymer membranes, factors limiting the lifetime of fuel cell membranes, a new highly active oxygen reduction electrode for PEM fuel cell and zinc/air battery applications, the enhancement of PEFC durability and reliability, model-based investigation of PEFC performance, and local gas analysis of PE fuel cells are briefly reported on. Long-term research activities in the hydrogen technology area reported on include those ...

2008-07-01

483

Evaluation of a novel radiopacifiying agent on the physical properties of surgical spineplex.

During the second half of 1993, the groundwater at the F-Area Seepage Basins (FASB) was monitored in compliance with Module 3, Section C, of South Carolina Hazardous Waste Permit SC1-890-008-989, effective November 2, 1992. The monitoring well network is composed of 87 FSB wells screened in the three hydrostratigraphic units that make up the uppermost aquifer beneath the FASB. A detailed description of the uppermost aquifer is included in the Resource Conservation and Recovery Act Part B post-closure care permit application for the F-Area Hazardous Waste Management Facility submitted to the South Carolina Department of Health and Environmental Control (SCDHEC) in December 1990. Beginning in the first quarter of 1993, the standard for comparison became the SCDHEC Groundwater Protection Standard (GWPS) specified in the approved F-Area Seepage Basins Part B permit. Currently and historically, gross alpha, nitrate, nonvolatile beta, and tritium are among the primary constituents to exceed ...

1994-03-01

484

Element distribution in the brain sections of rats measured by synchrotron radiation X-ray fluorescence

Polymethlylmethacrylate (PMMA) is the most frequently used cement for percutaneous vertebroplasty and kyphoplasty. To aid visualisation during surgery cements are doped with radiopacifying agents such as Barium sulphate (Ba(2)SO(4)) or Zirconium Dioxide (ZiO(2)). Mounting research suggests that these agents may impair the biocompatibility of the cements. However, incorporating an alternative radiopacifier agent with excellent biocompatibility would be a significant step forward. Bioactive radiopaque glasses incorporating elements such as strontium (Sr) and zinc (Zn), known to have beneficial and therapeutic effects on bone, are of great interest in this respect. In this study, the Ba(2)SO(4) of the commercially available Spineplex was incrementally replaced with a radiopaque therapeutic glass composition. The resulting effects on cement setting time, peak isotherm, ultimate compressive strength, Young's modulus (up to 30 days cement maturation) and radiopacity were ...

2009-08-18

485

Effects of acid mine drainage on a headwater stream ecosystem in Colorado

The concentration of trace elements in brain sections was measured by synchrotron radiation X-ray fluorescence. The relative concentration was calculated by means of the normalization of Compton scattering intensity approximately 22 keV, after the normalization for collecting time of X-ray spectrum and the counting of the ion chamber, and subtracting the contribution of the polycarbonate film for supporting sample. Furthermore, the statistical evaluation of the element distribution in various regions of the brain sections of the 20-day-old rats was tested. For investigating the distribution of elements in the brain of iodine deficient rats, Wistar rats were fed with iodine deficient diet and deionized water (ID group). The rats were fed the same iodine deficient diet, but drank KIO_3 solution as control (CT group). The results showed that the contents of calcium (Ca) in thalamus (TH) and copper (Cu) and iron (Fe) in cerebral cortex (CX) of ID rats were significantly lower than that of ...

2004-02-27

486

Distribution of blood lead, blood cadmium, urinary cadmium, and urinary arsenic levels in employees of a copper smelter

The ecological effects of acid mine drainage were investigated during the summer of 1993 on St. Kevin Gulch, a headwater stream near Leadville, Colorado. The stream currently receives acidic water from an abandoned mine. The pH downstream of the mine is between 3.5 and 4.5, and several metals exceed concentrations toxic to aquatic organisms. Zinc is present at especially high concentrations (1 to 10 mg/L) Furthermore, the stream bottom is covered with a thick layer of iron hydroxide precipitates. Effects on stream biota have been dramatic. Aquatic flora in the affected reach is limited to a green filamentous alga, Ulothrix subtilissima. Macroinvertebrate densities are significantly lower in the affected reach (mean = 99 indiv/m"2; SD = 88 indiv/M"2) compared to an upstream (pristine) reference reach (mean = 1,735 indiv/m"2; SD = 652 indiv/M"2). Functional processes were also studied in the stream. Net primary production (NPP) was measured during midday with ...

487

Dispersion of Metals from Abandoned Mines and their Effect on Biota in the Methow River, Okanogan County, Washington: Final Report 2002-2003.

A cross-sectional medical examination of a copper smelter work force included determination of blood lead (Pb-B), zinc protoporphyrin (ZPP), blood cadmium (Cd-B), urinary cadmium (Cd-U), and urinary arsenic (As-U), since it was known that such metal impurities were present in the copper concentrate. A total of 776 copper smelter employees (680 active and 96 retirees and ex-employees) were examined. Another 144 men, never employed in the smelter, but who had worked in copper mines (and sometimes in gold mines) were also examined. Mean Pb-B, ZPP, Cd-B, and As-U were significantly higher in active copper smelter employees than in retirees or miners, indicating exposure and absorption in the copper smelter. Significant correlations between Pb-B and Cd-B, and Cd-U and As-U were present, confirming the common source of absorption. Although there was evidence for an increased lead absorption, this was very moderate, with practically no Pb-B levels in excess of 60 ...

1984-02-01

488

Development of a HVDC prototype breaker. Final report

A study of mine-waste contamination effects on Methow River habitat on the eastern slopes of the north Cascade Mountains in Washington state, U.S.A., revealed impacts at ecosystem, community, population, individual, tissue, and cellular levels. Ore deposits in the area were mined for gold, silver, copper and zinc until the early 1950's, but the mines are now inactive. An above-and-below-mine approach was used to compare potentially impacted to control sites. The concentrations of eleven trace elements (i.e., Al, As, B, Ba, Cd, Cr, Cu, Mn, Pb, Se, and Zn) in Methow River sediments downstream from the abandoned mine sites were higher than background levels. Exposed trout and caddisfly larvae in the Methow River showed reduced growth compared to controls. Samples of liver from juvenile trout and small intestine from exposed caddisfly larvae were examined for evidence of metal accumulation, cytopathological change, and chemical toxicity. Morphological changes ...

2003-05-15

489

Determination of trace amounts of cadmium, cobalt, chromium, iron, molybdenum, nickel, selenium, titanium, vanadium and zinc in blood and milk by neutron activation analysis

The significant design features of a high-voltage dc (HVDC) circuit breaker based on the commutation concept were developed. Tests of components indicate the breaker is capable of interrupting a fault current of 10 kA on a 400 kV system and absorbing up to 10 MJ of system energy without generating more than 1.6 per unit (P.U.) voltage of the system. Interactions of the breaker with a three-terminal network were studied, using a system simulator. An ultrafast hydraulic actuator system was developed for this program which enables the breaker to initiate the current limiting process within 5 ms after receipt of a trip signal. A new hydraulic valve, operated by a repulsion coil, minimizes the delay before motion begins. Interruption will occur in series-connected vacuum interrupters. A 400 kV circuit breaker is estimated to require eight breaks in series. Only a single break was tested as part of this program because of the scale and cost required for multibreak tests. System energy will ...

1980-06-01

490

Depth Profiling of N and C in Ion Implanted ZnO and Si Using Deuterium Induced Nuclear Reaction Analysis

The concentrations of Cd, Co, Cr, Fe, Mo, Ni, Se, Ti, V and Zn in biological fluids, human blood serum and market milk were determined by neutron activation analysis, with enrichment by coprecipitation. The pre-concentration of these trace elements was accomplished by converting the dissolved trace metal ions into their pyrrolidinedithiocarbamate (1-pyrrolidinecarbodithioate) chelates, followed by coprecipitation with a metal carrier such as Ni, Pb or Bi. The coprecipitation was carried out prior to irradiation for the short-lived nuclides (V, Ti and Se) and after irradiation for the other elements. The validity of the method was checked using certified biological reference materials; the concentrations of trace elements found by the proposed method agreed well with the published certified data. The limits of detection for Cd, Co, Cr, Fe, Mo, Ni, Se (obtained through the long-lived isotope "7"5Se) and Zn under the present experimental conditions were found to be 5, 5, 10, 520, 5, 70, ...

491

Corrosion behaviors of Zn/Al-Mn alloy composite coatings deposited on magnesium alloy AZ31B (Mg-Al-Zn)

Nuclear Reaction Analysis (NRA) with deuteron ion beams has been used to probe for ion implanted nitrogen and carbon with high sensitivity in zinc oxide and silicon single crystals. The ion implanted N was measured using 1.4 MeV deuteron ion beams and was found to be in agreement with calculated values. The limit of detection for N in ZnO is 8x1014 ions cm-2. Raman measurements of the ion implanted samples showed three additional modes at 275, 504, and 644 cm-1 compared to the un-implanted ZnO crystals. The NRA and Raman results provided information on the N concentration, depth distribution, and structural changes that occur in dependence on the nitrogen ion fluences. The deuterium induced 12C(d,p)13C reaction was used to measure the carbon impurity/dose in ion implanted silicon. It was found that the use of a large cold shield (liquid nitrogen trap) in the ion implanter chamber greatly reduces the amount of carbon impurity on the surface of ion implanted silicon. ...

2008-11-03

492

Biosorption of heavy metals

After being pre-plated a zinc layer, an amorphous Al-Mn alloy coating was applied onto the surface of AZ31B magnesium alloy with a bath of molten salts. Then the corrosion performance of the coated magnesium alloy was examined in 3.5% NaCl solution by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results showed that the single Zn layer was active in the test solution with a high corrosion rate while the Al-Mn alloy coating could effectively protect AZ31B magnesium alloy from corrosion in the solution. The high corrosion resistance of Al-Mn alloy coating was ascribed to an intact and stable passive film formed on the coating. The performances of the passive film on Al-Mn alloy were further investigated by Mott-Schottky curve and X-ray photoelectron spectroscopy (XPS) analysis. It was confirmed that the passive film exhibited n-type semiconducting behavior in 3.5% NaCl solution with a carrier density two orders of magnitude less ...

2009-12-30

493

Assimilation of cadmium, chromium, and zinc by the green mussel Perna viridis and the clam Ruditapes philippinarum

Only within the past decade has the potential of metal biosorption by biomass materials been well established. For economic reasons, of particular interest are abundant biomass types generated as a waste byproduct of large-scale industrial fermentations or certain metal-binding algae found in large quantities in the sea. These biomass types serve as a basis for newly developed metal biosorption processes foreseen particularly as a very competitive means for the detoxification of metal-bearing industrial effluents. The assessment of the metal-building capacity of some new biosorbents is discussed. Lead and cadmium, for instance, have been effectively removed from very dilute solutions by the dried biomass of some ubiquitous species of brown marine algae such as Ascophyllum and Sargassum, which accumulate more than 30% of biomass dry weight in the metal. Mycelia of the industrial steroid-transforming fungi Rhizopus and Absidia are excellent biosorbents for lead, cadmium, copper, ...

1995-05-01

494

Assessment of trace element contents of chicken products from turkey

The green mussel Perna viridis and the clam Ruditapes philippinarum have been frequently used as biomonitors of coastal contamination in subtropical and tropical waters, yet the physiological processes controlling metal uptake in these bivalves are unknown. Assimilation efficiency (AE) is an important physiological parameter quantifying metal bioavailability from ingested food. The authors determined the AEs of Cd, CR, and Zn in these bivalves feeding on five species of phytoplankton and one natural section. The influences of the cytoplasmic distribution of metals in the algal cells and the digestive physiology of bivalves on metal AEs were also examined. Among the three metals, Zn was generally assimilated at the highest efficiency, i.e., 21 to 36% in the mussels and 29 to 59% in the clams. Cr was the least assimilated metal, with AEs being 10 to 16% in the mussels and 11 to 24% in the clams. The AEs of Cd and Zn in the clams were 1.8 to 4.7 and 1.1 to 1.9 times higher, respectively, ...

2000-06-01

495

Radiation damage measurements in room temperature semiconductor radiation detectors

Due to the consumption of chicken and chicken products in Turkey at high ratio, trace metal content of chicken and chicken products from Turkey were determined by atomic absorption spectrometry after microwave digestion. The accuracy of the method was confirmed by analysis of standard reference material (NIST SRM 1577b Bovine liver). Trace element content in various parts of chicken samples and chicken products were to be in the range of 0.10-114 {mu}g/g for copper, 0.25-6.09 {mu}g/kg for cadmium, 0.01-0.40 {mu}g/g for lead, 0.10-0.91 {mu}g/g for selenium, 0.05-3.91 {mu}g/g for manganese, 0.06-0.10 {mu}g/g for arsenic, 0.01-0.72 {mu}g/g for chromium, 0.01-2.08 {mu}g/g for nickel, 0.01-0.02 {mu}g/g for cobalt, 0.10-1.90 {mu}g/g for aluminium, 1.21-24.3 {mu}g/g for zinc, 2.91-155 {mu}g/g for iron. The levels of lead in some analyzed chicken products were higher than the recommended legal limits for human consumption.

2009-04-30

496

Neutron activation analysis for determination of selected trace elements responsible for immunity in foodstuffs and water in egypt

The literature of radiation damage measurements on cadmium zinc telluride (CZT), cadmium telluride (CT), and mercuric iodide (HgI{sub 2}) is reviewed and in the case of CZT supplemented by new alpha particle data. CZT strip detectors exposed to intermediate energy (1.3 MeV) proton fluences exhibit increased interstrip leakage after 10{sup 10} p/cm{sup 2} and significant bulk leakage after 10{sup 12} p/cm{sup 2}. CZT exposed to 200 MeV protons shows a two-fold loss in energy resolution after a fluence of 5 {times} 10{sup 9} p/cm{sup 2} in thick (3 mm) planar devices but little effect in 2 mm devices. No energy resolution effects were noted from moderated fission spectrum of neutrons after fluences up to 10{sup 10} n/cm{sup 2}, although activation was evident. Exposures of CZT to 5 MeV alpha particle at fluences up to 1.5 {times} 10{sup 10} {alpha}/cm{sup 2} produced a near linear decrease in peak position with fluence and increases in FWHM beginning at about 7.5 ...

1998-12-01

497

7. Kassel symposium on energy systems technology: Renewable energy sources and efficient utilization of energy; 7. Kasseler Symposium Energie-Systemtechnik: Erneuerbare Energien und rationelle Energieverwendung

Selenium (Se), zinc (Zn), magnesium (Mg), molybdenum (Mo) and vanadium (V) in 28 types of Egyptian common foodstuffs as well as drinking and irrigation water samples were determined using neutron activation analysis (NAA) and atomic absorption spectrometry (AAS). The samples were collected from 74 sites over 13 governorates as well as the Nile river, wells and tap water in the regions of the Nile Delta, Sinai, the east and west desert, and north and south Egypt. These trace elements were chosen according to international references, which show the close relationship of their deficiencies to immunity-related diseases. Calculation values of daily uptake per capita were made with the results of analysis. The results, as calculated per 100 g dry weight, showed that some Egyptian foods are rich in Se including such fish (0.94 #mu#g), sesame (0.88 #mu#g), beef meat (0.48 #mu#g), instant tea (0.42 #mu#g), mushroom (0.34 #mu#g) and eggs (0.3 #mu#g), whereas the vegetables ...

498