Energy Technology Data Exchange (ETDEWEB)

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 ...

International Nuclear Information System (INIS)

The effect of high energy neutron irradiation (E > 1 MeV) on the superconducting transition temperature, Tsub(c), of the A-15 compound Mo_3Os is reported. Tsub(c) was found to decrease with increasing neutron dose, but at a rate considerably less than observed in other A-15 compounds composed of non-transition metals. The results lend support to the idea that the effect of ordering on Tsub(c) is smaller for A-15 compounds composed only of transition metals than those composed of transition and non-transition metals. (author).

Energy Technology Data Exchange (ETDEWEB)

Discusses results of investigations into catalytic properties of various minerals during hydrogenation of Kansk-Achinsk brown coal with a view to replacing synthetic compositions based on molybdenum. Describes tests and equipment used in hydrogenation of grade B-2 Borodinsk deposit coal in tetralin (hydrogen donor). Various by-products of metallurgical processes and compounds separated from tailings containing mainly iron and sulfur and other metals were used as catalysts. States that: minerals containing iron compounds in the form of pyrites, hematites and magnetites exhibit catalytic properties when used in the hydrogenation of brown coal; pyritic catalysts enrich liquid products with hydrogen while sulfur and nitrogen content remains the same; the yield of malthenes with pyritic catalysts is no lower than with alumocobaltmolybdenum catalysts. 18 refs.

International Nuclear Information System (INIS)

The variation in the superconducting properties of various binary alloys of transition metal-germanium systems was surveyed by studying sputter deposited samples prepared under various conditions. The primary interest has been to study the formation of the stoichiometric A-15 compounds T_3Ge.

International Nuclear Information System (INIS)

A simple model is used to explain the decrease in superconducting critical temperature with damage observed for irradiated A-15 compounds. A truncated t-matrix approximation is used to describe the disorder along the one-dimensional transition metal chains. Three dimensionality is introduced by the inclusion of interaction between transition metal atoms on different chains. Numerical fits to experiment are discussed in the conclusion. (author).

Energy Technology Data Exchange (ETDEWEB)

The compound GdPd{sub 2}Si, which is reported to order antiferromagnetically at 13 K, has been investigated by heat capacity and electrical resistivity measurement in the presence of external magnetic fields. In contrast to an earlier report, the zero-field heat capacity and resistivity data indicate two magnetic transitions at 13 and 17 K. The external magnetic field substantially influences the resistivity and heat capacity of the compound around the magnetic ordering temperature. The magnetocaloric effect, which is calculated from in-field heat capacity data, is quite large around the magnetic transition temperature. The magnetoresistance is also large near the magnetic ordering temperature. The metamagnetic transition is observed for 10 kOe magnetic field both in magnetocaloric and in magnetoresistance data. The metamagnetic transition strongly influences ...

Energy Technology Data Exchange (ETDEWEB)

In this work, a mixed cationic--anionic [i.e. cetyltrimethylammonium bromide-sodium octyl sulphate] surfactant system was used to synthesize the magnetite particles. The loading content of iron ions (Fe{sup 3+} and Fe{sup 2+}) into the surfactant system was varied to study its effect on the formation of magnetite, magnetic and morphological properties of the magnetite particles encapsulated by the surfactant vesicles. It has been verified that the vesicle-encapsulated magnetite particles with sizes from 100 to 200 nm were formed, which were almost independent of the loading content of iron ions. However, the morphological structure of the magnetite particles was dependent on the loading content of iron ions and there existed an optimal loading content for a full packing of the surfactant vesicles with the magnetite particles.

Energy Technology Data Exchange (ETDEWEB)

In vitro cytocompatibility and cellular interactions of lauric acid and dextran-coated magnetite nanoparticles were evaluated with two different cell lines (mouse fibroblast and human cervical carcinoma). Lauric acid-coated magnetite nanoparticles were less cytocompatible than dextran-coated magnetite nanoparticles and cellular uptake of lauric acid-coated magnetic nanoparticles was more than that of dextran-coated magnetite nanoparticles. Lesser cytocompatibility and higher uptake of lauric acid-coated magnetite nanoparticles as compared to dextran-coated magnetic nanoparticles may be due to different cellular interactions by coating material. Thus, coating plays an important role in modulation of biocompatibility and cellular interaction of magnetic nanoparticles.

Energy Technology Data Exchange (ETDEWEB)

To study the plasma evolution and spatial structure at the L/H transition, the double hysteresis is examined by use of the 1-dimensional transport model equations. Three mechanisms for the bipolar losses, i.e., the loss cone loss, collisional bulk viscosity loss of ions and the anomalous loss are simultaneously retained. Five-fold multiple bifurcations are found to exist at the plasma edge, similar to the previous 0-dimensional study. Double hysteresis causes a self-generated oscillation, which is attributed to the compound dither, a kind of ELMs. Spatio-temporal evolution of the compound dither is analyzed. (author)

Energy Technology Data Exchange (ETDEWEB)

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.

International Nuclear Information System (INIS)

Observed 7-eV satellites in the XPS spectra of UGa_2 and other B-group compounds are shown to be due to two-hole final states as confirmed by existing Auger data. The presence of these satellites is an indication for a weak fd hybridization and, when compared to uranium--transition-metal compounds, increased 5f localization.

International Nuclear Information System (INIS)

The influence of 3d-transition metal impurities on the superconducting properties of the A-15 compounds V_3Si and V_3Ga have been investigated. In the case of V_3Si, the Fe impurities replacing V were found to have a local moment. A compensation effect was found in this case, resulting in a 20KOe increase in the upper critical field at dilute concentrations of Fe. It was demonstrated that long range order V_3Ga possessed higher transition temperature and upper critical field than found hitherto. Investigations on Nb_3Ge/sub 1-x/Ga/sub x/ films obtained by chemical vapor deposition has clearly shown the relation between the transition temperature and structural characteristics. The influence of generalized defects on the superconducting properties in A-15 type Nb_3X compounds has been discussed.

International Nuclear Information System (INIS)

Chemical effects of L X-ray intensity ratios in niobium and molybdenum compounds were studied by electron and proton bombardments. L_#gamma#_1 X-rays which involve transition of 4d electrons of the valence shell were found to be sensitive to the chemical environment. The L_#gamma#_1/L_#beta#_1 X-ray intensity ratio increased with an increase of the 4d electron occupation of niobium or molybdenum in niobium or molybdenum compounds, showing that the chemical effects can be ascribed to the 4d electron behavior of the metallic atom in its compounds. (orig.).

International Nuclear Information System (INIS)

The deposit of radioactive corrosion products in the cooling systems of nuclear reactors becomes a serious problem for the personnel of facilities. Crud has an important role in the process of depositing radioactive corrosion products. The main components of crud are hematite, magnetite, nickel ferrite and so on, and the particles of these oxide compounds are distributed in water. Most of the behavior of crud are still not known. As for the mechanism of the production of crud, the Potter-Mann model has been proposed. However, the precipitation process of iron ions in water is unknown. The crud is defined as the particles filtered by 0.45 micrometer millipore filters. However, it is not known whether there are crud particles smaller than this size. The crud particles can be adsorbed on the filters by the surface electrochemical interaction. The adsorption of cations to crud particles was studied. The adhesion of crud particles was investigated ...

International Nuclear Information System (INIS)

The federating theme of superconductivity has given rise to a number of experimental studies of point defects in solids as different as transition metals (V, Nb, ...), A-15 compounds (V_3Si, Nb_3Ge, ...), or perovskite-like copper oxides. Some of these experiments are presented here. (orig.).

Science.gov (United States)

We studied a novel universal spectrochemical series of six-coordinated octahedral 3d transition metal complexes, which can be used for any combination of central metal atom and ligand molecules. A two dimensional spectrochemical series could be used to estimate the ligand field splitting energy of not only known compounds but also the unknown compounds. Therefore, it should be possible to control the physical properties, such as the electronic and magnetic properties and the optical phenomena of octahedral transition metal complexes by modifying the ligand field splitting. PMID:19378561

Science.gov (United States)

It is shown that the extended softening in k space of the [111] transverse acoustic phonon in Nb3Sn seen recently by neutron measurements is in agreement with the predictions of a phenomenological Landau description of the structural phase transition in the A-15 compounds. This indicates the feasibility of a calculation of the partial phonon density of states of modes directly coupled to the order parameter driving the structural transition, as a function of temperature.

Energy Technology Data Exchange (ETDEWEB)

Progress in calculating the electron-phonon parameters of transition metals has been based on either the rigid muffin-tin approximation (RMTA) or the fitted modified tight-binding approximation (FMTBA). The RMTA has been shown to be remarkably accurate for average electron-phonon properties, but there are indications that RMTA matrix elements may be too small at low momentum transfer. An attempt is made to demonstrate these assertions concerning the accuracy of RMTA and the numerous electron-phonon calculations are placed in a broader perspective by a demonstration of how they can be used to explain the trends in the strength of the electron-phonon coupling among the transition metals and the A-15 compounds. (GHT)

International Nuclear Information System (INIS)

The structural instability in high temperature A-15 superconductors is examined from a phenomenological, Landau theoretic point of view, based on the picture of an electronically driven lattice instability. emphasis is given to lattice properties--in particular, the extended softening of phonons in k-pace and phonon linewidth. Implications of the extended softening on the microscopic picture of the transition, and the interplay between structural and superconducting instabilities in the A-15 compounds are discussed.

International Nuclear Information System (INIS)

Within the tight binding framework, a study is made of how the disorder affects the electronic properties of A-15 compounds. In particular it is shown that for compounds of two transition metals in the A-15 structure, the vacancy formation affects the density of states only in the low energy region or in the high energy region, in opposition with the isolated chain model of Labbe and Friedel. It is concluded that interchain interactions are important. (U.K.).

International Nuclear Information System (INIS)

It has recently been shown that the superconducting properties of Nb-base A-15 compounds, A_3B, are severely degraded when exposed to high-energy (E>1 MeV) neutron irradiation at ambient reactor temperatures. In each case, superconducting transition temperatures, Tsub(c), and the Bragg Williams order parameters, S, were observed to decrease steadily with irradiations in excess of 10"1"8 nvt. During irradiation the A-15 structure is retained and subsequent isothermal annealing restores almost completely the compound's original Tsub(c) value. In this letter a correlation between B atom diameter and the recovery rates of Tsub(c) for the irradiated materials Nb_3Ge, Nb_3Ga, Nb_3Al and Nb_3Sn is reported. (Auth.).

International Nuclear Information System (INIS)

The adherent magnetite film thickness, corrosion rate and the loose crud on the surface of carbon steel and other structural materials were evaluated by inserting the coupons in the two autoclaves connected to the two ends of the PHT systems of Indian PHWRs. This paper includes an analysis of the results obtained during the hot conditioning of TAPP-3 and 4, Kaiga-3 and 4, and RAPP-5. The system temperatures of 230 deg C to 260 deg C and the adherent magnetic thickness of 0.30 ?m to 0.75 ?m on the internal surface of carbon steel were achieved during the hot conditioning of these reactors. The time duration of termination of the hot conditioning ranged from 48 to 71 hours. The maximum magnetite film thickness of 0.75 ?m in 71 hours and temperature 260 deg C and a minimum thickness of 0.30 nm in 48 hours at 230 deg C were achieved during hot conditionings. The XRD analyses of hot conditioned carbon steel coupons showed that oxide film constitutes ...

Energy Technology Data Exchange (ETDEWEB)

The magnetic susceptibility and high-field magnetization have been measured for the intermediate valence system Eu(Pd{sub 1{minus}x}Pt{sub x}){sub 2}Si{sub 2} with 0{le}x{le}0.15. A first-order valence transition is observed for all the compounds under high field of 100 T at low temperatures. This valence transition is of first order accompanied with a large hysteresis, which is in contrast to a continuous valence change against temperature. Based on the interconfigurational fluctuation (ICF) model, the temperature- and field-induced valence transitions are discussed. It is found that a first-order valence transition can be induced by magnetic field, even if the system shows a continuous valence transition against temperature. Metamagnetic behavior at finite temperatures is also understood qualitatively by the ICF model. {copyright} {ital 1997} {ital The ...

Energy Technology Data Exchange (ETDEWEB)

This report measured the rate of isothermal deposition of sub-micron particles of magnetite onto the surface of Alloy 800 at pH of 4.2-9.3 at Re=10,000 and a fluid temperature of 25C. Deposition is modelled as a two-step process, the transport of particles to the surface region followed by attachment to the surface.

Energy Technology Data Exchange (ETDEWEB)

The study is concerned with the combined effect of high pressure and shear strain on the properties of the A-15 intermetallics Nb3Sn and Nb3Al0.75Ge0.25. The properties discussed are the superconducting transition temperature, the width and intensity of the X-ray diffraction lines, and the width and shape of the Mossbauer absorption lines. It is shown that the combined effect of high pressure and shear strain leads to an intense generation of defects in polycrystalline specimens; the size of the ordered regions does not exceed 300 A even under the least severe conditions. 5 references.

Energy Technology Data Exchange (ETDEWEB)

A transition from petroleum~derived jet fuels to blends with Fischer-Tropsch (F~T) fuels, and ultimately fully synthetic hydro-isomerized F-T fuels has raised concern about the fate of plasticizers in nitrile-butadiene rubber a-rings that are contacted by the fuels as this transition occurs. The partitioning of plasticizers and fuel molecules between nitrile a-rings and petroleum-derived, synthetic, and additized-synthetic jet fuels has been measured. Thermal desorption of o-rings soaked in the various jet fuels followed by gas chromatographic analysis with a mass spectrometric detector showed many of the plasticizer and stabilizer compounds were removed from the o-rings regardless of the contact fuel. Fuel molecules were observed to migrate into the o-rings for the petroleum-derived fuel as did both the fuel and additive for a synthetic F-T jet fuel additized with benzyl alcohol, but less for the unadditized synthetic ...

International Nuclear Information System (INIS)

The cubic-tetragonal lattice transformation in A-15 compounds is described by an empirical model in which the density of states function near the Fermi energy is characterized by a two-parametric peak in addition to the constant part. Two types of peak splitting under tetragonal deformation are considered, leading to qualitatively different results about the phase transition. Results are given for the order parameter, the phase stability, the soft elastic modulus, and the paramagnetic spin susceptibility. Comparing with measurements of the magnetic susceptibility of V_3Si single crystals near the phase transition a better agreement is obtained for a twofold degenerate density of states peak than for a threefold degenerate one. (author).

International Nuclear Information System (INIS)

The behavior of the superconducting transition temperature T/sub c/ of single-crystal and polycrystalline V_3Si was investigated as a function of low-fluence neutron irradiation. It is found that the initial degradation of T/sub c/ is sample-dependent, some specimens showing no degradation in T/sub c/ up to a fluence of 2 x 10"1"8 n/cm"2. This and many other earlier observations on low-fluence behavior are explained in terms of a recently proposed model of radiation damage in A-15 compounds.

International Nuclear Information System (INIS)

The structural transition and anomalous properties of the high temperature A-15 superconductors have been investigated from two different standpoints. The first is a Landau theory based on Gorkov's physical model of a Peierls-like charge density wave (CDW) transition involving electronic CDW order parameters coupled to phonon coordinates. Pretransition elastic anomalies, softening of the [1 anti 10] transverse ([1 anti 10] polarized) phonon, sublattice distortions, variation of transition temperature with stress and alloying and other effects have been accurately predicted, and a detailed comparison is made with experimental results. Central peaks in neutron scattering are shown to be non-dynamic in nature and no pretransition forbidden (300) reflection is predicted. The GAMMA_1_2 optic mode does not go soft at the transition, though its frequency is expected to be temperature dependent right up to room ...

International Nuclear Information System (INIS)

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.).

International Nuclear Information System (INIS)

The following methods of quartz ceramics alloying were considered: alloying of initial quartz glass; introduction of alloying additive into water slip of quartz glass; porous materials impregnation with salt aqueous solutions and subsequent salt thermal decomposition with formation of stable oxides in pores of ceramics. Oxygen free compounds BN, SiB_4, SiC, Si_3N_4, REM oxides and transition metal oxides were used as alloying additives. Main properties of the materials and compositions obtained are presented.

Energy Technology Data Exchange (ETDEWEB)

The existence of a narrow peak of electron state density in A-15 is explained by a strong electron-phonon interaction that brings about the polaron narrowing of zone. In the supposition of weak and intermediate bond, the analytical expression for the critical transition temperature is found that corre lates Tsub(c) with phonon spectrum. The model permits to explain Tsub(c) correlation with the number of electrons per atom, temperature direction of resistance, value and temperature dependence of magnetic susceptibility and electron thermal capacity.

Energy Technology Data Exchange (ETDEWEB)

Certain transition metal chalcogenides are promising materials for use as cathodes in nonaqueous lithium batteries involving the intercalation into these layered compounds. The electrochemical behavior of the chalcogenides depends on various properties such as structure, stoichiometry, electrical conductivity, crystal morphology, etc. The influence of these properties and of the ultimate practical application of the battery on the selection of cathode material is discussed. Battery performance of selected cathode materials is discussed and life limitations due to the limited cycle life of lithium anodes are outlined. 15 refs.

Energy Technology Data Exchange (ETDEWEB)

Properties of highly correlated electrons, such as heavy fermion compounds, metal-insulator transitions, one-dimensional conductors and systems of restricted dimensionality are studied theoretically. The main focus is on Kondo insulators and impurity bands due to Kondo holes, the low-temperature magnetoresistivity of heavy fermion alloys, the n-channel Kondo problem, mesoscopic systems and one-dimensional conductors.

International Nuclear Information System (INIS)

The thermodynamics of the Sr-Si system is of fundamental importance for the understanding of eutectic modification of Al-Si alloys. At the same time, strontium silicides have recently been found to have potential applications in electronic devices. Renewed research efforts have led to a re-evaluation of the phase equilibria in this system, resulting in the discovery of previously undetected stable intermetallic compounds. In this work, we investigate the finite temperature thermodynamic properties of the stable (and metastable) Sr-Si intermetallics. The vibrational properties of the intermetallic compounds are calculated within harmonic theory, with quasi-harmonic corrections to account for the effects of thermal expansion. The total free energies of the compounds are computed considering vibrational and electronic contributions, as well as weak anharmonic corrections. The ground state of the system is predicted and ...

International Nuclear Information System (INIS)

In this work we study the structural and electronic properties of Be chalcogenides (BeS, BeSe and BeTe) using two different methods: the full-potential linear augmented-plane wave (FP-LAPW) and the plane-wave pseudopotential (PPsPW). The exchange-correlation effects are treated in the local-density approximation (LDA) and the generalized-gradient approximation (GGA). We have evaluated the ground-state quantities such as equilibrium volume, bulk modulus and its pressure derivative as well as the elastic constants. Various structural phase transitions were considered here in order to confirm the most stable structure and to predict the phase transition under hydrostatic pressure. In addition we have studied the band structure and the density of states, which show a wide indirect band gap for these compounds. These results were in favourable agreement with previous theoretical works and the existing experimental data. To ...

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

A numerical model was developed to simulate the combined effects of heat transfer, magnetite oxidation, and NO{sub x} formation in a grate-kiln furnace for taconite pellet induration. Heat transfer from the flame in the kiln was described by the net radiation method. The shrinking core model was used to account for magnetite oxidation on the grate. A novel approach to oxidation of tumbling pellets in a kiln was derived. The Zeldovich mechanism was used to predict thermal NO generation. Temperature fluctuations in the gas streams were estimated with a clipped Gaussian probability density function. The thermal energy balances and mass balances resulted in coupled systems of first-order differential equations, which were solved numerically. The model is capable of predicting NO production and magnetite oxidation in agreement with observation of plant performance. Although the design of the grate-kiln system is for efficient ...

UK PubMed Central (United Kingdom)

Magnetotactic bacteria contain chains of magnetically interacting crystals (magnetosome crystals), which they use for navigation (magnetotaxis). To improve magnetotaxis efficiency, the magnetosome crystals...Full Text Available

International Nuclear Information System (INIS)

The paper is concerned with the simulation of practical testing situations which are too difficult and/or expensive to replicate in a laboratory environment. Numerical experiments are described which simulate the differential eddy current probe response to the build-up and chemical flushing of magnetite in the crevice gap of a PWR steam generator unit. The simulation results agree well with the only experimental data available to the authors and lead to the conclusion that conventional differential eddy current probes should be capable of characterizing crevice gap conditions with respect to the presence of magnetite. (author).

International Nuclear Information System (INIS)

The A-15 compounds are known to favor the occurrence of high temperature superconductivity (transition temperature T/sub c/ > 15K). The origin of superconductivity in these metals is a subject of much controversy and importance. A useful approach to this problem is to study comparatively the superconducting and normal-state properties of the A-15 superconductors and their amorphous counterparts. Efforts along these lines have yielded some insight into the mechanisms responsible for high temperature superconductivity. It is interesting to note that most high-T/sub c/ A-15 compounds contain one glass-forming element such as Ge, Si or Al and are thus conducive to the formation of a non-crystalline phase. The amorphous (or higher disordered) state of the A-15 compounds can be achieved, for example, by one of the following techniques: (1) sputtering or co-evaporation onto substrates held at relatively low ...

International Nuclear Information System (INIS)

The effect of lattice damage caused by room temperature irradiations with products of "1"0B(n,#alpha#)"7Li reactions and "2"3"5U fissions and with fast neutrons on transition curves, quenching curves, and lattice constants of Nb_3Sn, Nb_3Al, Nb_3(Al,Ge), and V_3Si have been investigated. The critical currents in transverse magnetic fields could be increased up to more than one order of magnitude. For heavily irradiated samples drastically reduced values for the critical currents, the upper critical fields, and the transition temperatures were observed. The lattice constants were increased up to 0.5 percent by irradiation. (U.S.).

International Nuclear Information System (INIS)

The universal depression of the superconducting transition temperature T/sub c/ in disordered A-15 compounds is examined. It is found that their anomalous behavior can be explained by a simple model for the density of states, which is enhanced by disorder in some cases. The dramatic drop in T/sub c/ in constant density-of-states A-15 compounds like Nb_3Ge or Nb_3Al at a critical value of the resistivity can be attributed to overdamping of acoustic plasmons, which decreases the electron pairing interaction despite relatively small changes in the density of states. Agreement for T/sub c/ and susceptibility chi with previous calculations is found of the position of the Fermi energy is near a peak. Possible experiments are proposed to check the above models.

International Nuclear Information System (INIS)

The compounds CePdSi_2, CeIrSi_2 and CeRhSn_2 have been synthesized and studied by X-ray diffraction, electrical resistivity and magnetic susceptibility. The magnetic susceptibility of CePdSi_2 exhibits two peaks at 6.8 K and 2.5 K, respectively, indicating two antiferromagnetic phase transitions, while that of CeIrSi_2 shows a broad maximum at 150 K, characteristic of valence fluctuating Ce-compounds. CeRhSn_2 remains paramagnetic down to 5 K. The resistivity of CeIrSi_2 exhibits a T"2 dependence at low temperatures, indicating a Fermi-liquid ground state, while those of CePdSi_2 and CeRhSn_2 shows the presence of Kondo and crystal field effects. (orig.).

Science.gov (United States)

Page 1. TRANSITIONING DARPA TECHNOLOGY ... Transitioning DARPA Technology JAMESJ.RJCHARDSON DIANE L. LARRNA ...

International Nuclear Information System (INIS)

In general there are actually two different types of A-15 compounds (A_3B) whose superconducting properties depend on whether the B atoms are transition elements (s-d type) or nontransition elements (s-p type). The properties in which the s-d type superconductors show marked differences in behavior from the s-p type include: (1) stoichiometry and range of composition, (2) the strong influence of N(O) on the stability and T/sub c/ of the phase, and (3), the effect of composition and atomic ordering on the T/sub c/ of the phase. These differences are discussed and a conclusion presented.

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

The characteristics of the temperature dependence of the upper critical magnetic field, Hc2(T), of structurally inhomogeneous superconductors (e.g., ternary molybdenum chalcogenides, A-15 compounds, transition metal alloys, and amorphous films) are investigated analytically. The MWGH equation for Hc2(T) is generalized to the case of weakly inhomogeneous systems with a characteristic inhomogeneity scale much smaller than the effective coherence length. It is shown that an increase in the dispersion of the diffusion coefficient leads to an increase in the slope and width of the linear section of the Hc2(T) curve. 11 references.

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

Measurements have been made on the magnetic susceptibilities of the quasi-one-dimensional magnetic #approx#-UF_5 and the cluster magnetic U_2F_9 (a four-nuclear type) over the range 4.2-300 K. The Curie-Weiss law applies for #approx#-UF_5 above 200 K, with #mu#ef = 2.37#mu#B, theta = -148 K; that law also applies to U_2F_9 above 150 K, with #mu#ef = 2.9#mu#B and theta = 118 K. The antiferromagnetic ordering is discussed for the one-dimensional chains in #approx#-UF_5 together with the phase transition observed in U_2F_9 at 6 K. It is assumed that the U"4"+ and U"5"+ valency states are stabilized below the phase-transition point, and only then can U_2F_9 be considered as the compound UF_4 x UF_5.

International Nuclear Information System (INIS)

Magnetic properties of layer ferromagnets against the thickness are investigated. Two new compounds served for studies: Bisub(6)Tisub(2)Nbsub(0,5)Fesub(2,5)Osub(18) and Bi_7Ti_3Fe_3O_2_1. The Moessbauer effect and the magnetic susceptibility measurements were applied in the experiment. The Faraday method was used in magnetic measurements in fields from 1 to 9,5 kOe. The results of Moessbauer measurements show that temperature dependence of the spectra is typical for compounds with superparamagnetic properties. The magnetic fields Hsub(n) on Fe"5"7 nuclei in Bisub(6)Tisub(2)Nbsub(0,5)Fesub(2,5)Osub(18) and Bi_7Ti_3Fe_3O_2_1 are similar and equal to 520+-10 kOe. Therefore it may be concluded that relaxation times of nuclear spins in these compounds are equal or close to each other. The lines of quadrupole splitting appear in spectra together at 20 K. The results of magnetic measurements show that the Curie-Weiss law is ...

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

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 ...

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

The near normal incidence reflectivity of the ferromagnets U"3P"4 and U"3As"4 and the isostructural but diamagnetic compounds Th"3P"4 and Th"3As"4 has been measured from 0.03 to 12 eV. Trithorium tetraphosphide and tetraarsenide are shown to be indirect gap semiconductors with gap energies of 0.43 and 0.39 eV, respectively. U"3P"4 and U"3As"4 display similar sets of p#->#d transitions than the corresponding thorium compounds, however, they are shifted by 0.85 eV to lower photon energies. It is concluded that the uranium compounds are metals due to a merging of the valence p band into the 6d conduction band giving direct experimental evidence for a p-f mixing effect of the same size. Energy level schemes are derived. (author).

Science.gov (United States)

Hamiltonians of Landau-Ginzburg-Wilson type are constructed for order parameters which are bases for certain high-dimensional irreducible or physically irreducible representations in A-15 structure. These are all the representations with wave vectors ?, X, and R and encompass cases of dimension 1, 2, 3, 4, and 6. A renormalization-group analysis was performed on each new distinct Hamiltonian using the Wilson-Fisher "? expansion" method to order ?, in order to determine fixed points and stability, and critical exponents. For representations of R wave-vector symmetry, only the two-dimensional R(1) has a stable fixed point and may produce a second-order phase transition; for all other R wave vector representations, fluctuations prevent second-order transition. No X point representation gives a second-order transition. Representations at ? which are permitted to be second order by "Landau theory" remain so in this analysis. ...

Energy Technology Data Exchange (ETDEWEB)

V{sub 2}O{sub 5} based compounds are interesting low potential materials for rechargeable cathodes of lithium electrochemical generators. However, the ionic conductivity and the reversibility of electrochemical cycling of V{sub 2}O{sub 5} are limited by the possibilities of lithium insertion. This work shows that the doping of vanadium pentoxide by a M{sup 3+} trivalent transition element (M Fe, Al, Cr or La) allows to intercalate a more important amount of lithium and to improve the behaviour of the material during cycling. These materials of M{sub 0.11}V{sub 2}O{sub 5.16} formula are obtained by sol-gel synthesis. the electrochemical study of the Fe compound has shown that it is a mixed oxide with a behaviour similar to V{sub 2}O{sub 5}. The maximum capacity is of about 2 F/mole in the case of Fe, Al and Cr compounds and of about 1.7 F/mole in the case of La. The structural evolution of the Fe ...

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

Some of the origins of corrosion encountered in the secondary side of pressurized water reactor steam generators are:-sludge accumulation (a mixture of metal oxides, primarily magnetite and copper) on tube sheet and attack of tube support plates by aggressive impurities leading to denting. Although Electricite de France has not suffered from these problems, it has developed a chemical cleaning process to dissolve corrosion products at both locations. (author).

Energy Technology Data Exchange (ETDEWEB)

Theoretical work supported by this grant has lead to the concept of the specific pinning force Q and the development of new methods to sum elementary interaction forces to find Q. Pinning due to changes in transition temperature or thermodynamic critical field in thin layers (e.g., a grain boundary), is greatly reduced due to the proximity effect and the stress field interaction due to the dislocations in the grain boundary has been shown to be negligible. The crystalline anisotropy (CA) and electron scattering (ES) interactions have been computed for the first time for an arbitrary boundary. Experiments on niobium bicrystals, polycrystalline niobium thin foils doped with oxygen, lead-bismuth alloy thin films and lead-bismuth alloy films in which either lead or thallium has been allowed to diffuse down the grain boundaries and out into the grains provide evidence that confirms the predictions of the theory. These results suggest that further improvements in grain ...

Energy Technology Data Exchange (ETDEWEB)

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

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The compounds CePdSi{sub 2}, CeIrSi{sub 2} and CeRhSn{sub 2} have been synthesized and studied by X-ray diffraction, electrical resistivity and magnetic susceptibility. The magnetic susceptibility of CePdSi{sub 2} exhibits two peaks at 6.8 K and 2.5 K, respectively, indicating two antiferromagnetic phase transitions, while that of CeIrSi{sub 2} shows a broad maximum at 150 K, characteristic of valence fluctuating Ce-compounds. CeRhSn{sub 2} remains paramagnetic down to 5 K. The resistivity of CeIrSi{sub 2} exhibits a T{sup 2} dependence at low temperatures, indicating a Fermi-liquid ground state, while those of CePdSi{sub 2} and CeRhSn{sub 2} shows the presence of Kondo and crystal field effects. (orig.). 5 refs.

Energy Technology Data Exchange (ETDEWEB)

In this systematic examination of some of the spectroscopic properties of the f-elements we deal with both the trivalent lanthanides and actinides. We summarize the present status of our energy level calculations in single crystal matrices and in aqueous solution, and compare the predicted crystal-field structure in certain low-symmetry sites with that observed. Some interesting new structural insights are thereby gained. The state eigenvectors from these calculations are then used in part in reassessing and interpreting the intensities of transitions in aqueous solution via the Judd-Ofelt theory. The parameters of this theory derived from fitting experimental data are compared with those computed from model considerations. Finally, we discuss some recent contributions to the interpretation of excited state relaxation processes in aqueous solution. 79 references, 23 figures, 17 tables.

Energy Technology Data Exchange (ETDEWEB)

High-field magnetization properties of single crystalline CeRh{sub 2}Si{sub 2} and CePd{sub 2}Si{sub 2} were investigated. Two-step metamagnetic transition (H{sub c1}=25.4 T and H{sub c2}=26.0 T) was observed in the case of CeRh{sub 2}Si{sub 2}, whereas no anomaly was found in the magnetization process of CePd{sub 2}Si{sub 2} up to 28 T. The mean field analysis has shown that CeRh{sub 2}Si{sub 2} is quite anisotropic compared to CePd{sub 2}Si{sub 2}, which results in the sharp contrast between the magnetization processes of the two compounds.

CERN Document Server

In these lecture notes we derive a generic holographic string theory realization of a p-wave superconductor and superfluid. For this purpose we also review basic D-brane physics, gauge/gravity methods at finite temperature, key concepts of superconductivity and recent progress in distinct realizations of holographic superconductors and superfluids. Then we focus on a D3/D7-brane construction yielding a superconducting or superfluid vector-condensate. The corresponding gauge theory is 3+1-dimensional N=2 supersymmetric Yang-Mills theory with SU(N) color and SU(2) flavor symmetry. It shows a second order phase transition to a phase in which a U(1) subgroup of the SU(2) symmetry is spontaneously broken and typical superconductivity signatures emerge, such as a conductivity (pseudo-)gap and the Meissner-Ochsenfeld effect. Condensates of this nature are comparable to those recently found experimentally in p-wave superconductors such as a ruthenate ...

International Nuclear Information System (INIS)

Coir pith (CP), an abundantly available lignocellulosic agricultural waste from the local coir industry has been found to be an effective biosorbent for removal of metal ions from aqueous solutions. Transition metal hexacyanoferrates, in particular nickel hexacyano ferrate (NiHCF) also referred to as Prussian blue analogue (PBA), is known to be highly selective for removal of cesium from aqueous solutions. A novel method for the synthesis of PBA inside the porous matrix of coir pith and use of this composite material for the sorption of cesium is described in this paper. Equilibrium experiments showed that the sorption capacity of coir pith nearly doubled due to the modification. Owing to its low cost and rapid sorption kinetics, this hybrid material seems to be one of the most promising compounds for the recovery of cesium from liquid nuclear wastes. (author)

International Nuclear Information System (INIS)

We have performed self-consistent (SC) band structure calculations for the A15 compounds V_3X and Nb_3X, X = Al, Ga, Si, Ge, and Sn, using the augmented-plane-wave (APW) method. Relativistic effects (except the spin-orbit interaction) have been included in each SC cycle, along with corrections to the usual muffin-tin approximation. The latter apply the APW wave functions outside of the muffin-tin spheres to compute the interstitial charge densities and potentials. The resulting interstitial potential has full cubic symmetry (no spherical averaging), although a spherically averaged muffin-tin form is retained inside the spheres. The final SC potentials were used to generate energies and wave functions on a cubic mesh of 35 k points in 1/48th of the Brillouin zone. These results were interpolated onto a finer mesh of 969 k points using a symmetrized Fourier method; the densities of states (DOS), N (E), were determined using tetrahedral integration. These accurate ...

International Nuclear Information System (INIS)

R_2PdSi_3 compounds have been found to exhibit rich magnetic phenomena arising from the interplay between RKKY interaction, crystal electric field effects and geometric frustration due to the derived hexagonal AlB_2 structure. The observed crystallographic superstructure further complicates the CEF level scheme. Inelastic neutron scattering measurements on single crystals of Tm_2PdSi_3 and Er_2PdSi_3 have been performed at the cold triple axis spectrometer PANDA in FRM-II. Both compounds order antiferromagnetically at T_N=7 K and 2.1 K respectively; Er_2PdSi_3 undergoes a second phase transition at T_2=2 K. Several low lying CEF excitations (below 10 meV) were observed. The intensity of the lowest excitation show strong directional dependence (in HK0 plane for Er_2PdSi_3 and in HHL plane for Tm_2PdSi_3), from which the details of the transitional matrix could be deduced. Measurements in magnetic fields ...

International Nuclear Information System (INIS)

The effect that different chemical and physical atomic environments can have on the relative intensities of radiative electron transitions from the filling of K shell vacancies was investigated. The method used involved the detection of photoionization induced X-ray fluorescence. An experimental system based on a hyper pure germanium detector (HPGE) was used to measure the relative K-L and K-M X-ray yields from the photofluorescence of a series of lanthanide elements and compounds. A background subtraction and peak integration strategy was employed which accounted for scattering in the samples and scattering of the flux from the radioisotope photoionization sources. Analysis of the data resulted in a tabulation of relative K/sub #beta#//K/sub #alpha#/ X-ray intensity ratios. The measured relative K/sub #beta#//K/sub #alpha#/ X-ray intensity ratios were compared to the calculated values predicted by the theoretical development of Scofield and ...

International Nuclear Information System (INIS)

Over the recent years the nuclear structure around the N = 50 shell closure, which is very pronounced in the strontium and zirconium isotopes, has been the subject of extensive experimental and theoretical work. On the proton side Z = 38 and Z = 40 provide fairly closed sub-shells. In the strontium isotopes the lg/sub 9/2/ neutron shell is closed at "8"8Sr, supplying relatively pure neutron-hole and neutron-particle states with large spectroscopic factors in "8"7Sr and "8"9Sr, as well as core-coupled states. The mass region is thus ideally suited to examine the transition from a correlated to an uncorrelated (chaotic?) excitational behavior. These two types are characterized e.g. by the density of excited states, the transition strengths, and the spectroscopic factors observed in transfer reactions. We conducted (n,#gamma#) and (d,p) reactions leading to /sup 87,88,89/Sr in addition to "8"8Sr(d,t)"8"7Sr and 24 keV neutron capture in "8"8Sr. The ...

Science.gov (United States)

... PADS(CUSHIONS), OBTURATION(BALLISTICS), BUTYL RUBBER, COMBUSTIBLE CARTRIDGE CASES, PHOSPHORUS COMPOUNDS. ...

Energy Technology Data Exchange (ETDEWEB)

The purpose of this work was to investigate the optical properties of several high T/sub c/ compounds in the form of sputtered films. The measurements are used toward this end: optical absorptance (using a calorimetric technique near 4.2K), which yields (after Kramers-Kronig analysis) the complex dielectric function, and thermoreflectance (which measures the change in reflectance in the optical range when a 1 to 10/sup 0/K temperature wave is applied), performed at two ambient temperatures (80 and 300/sup 0/K), yielding the differential dielectric function. The sputtered films included Nb/sub 3/Ge, Nb/sub 3/Al, V/sub 3/Ga and Nb/sub 3/Ir. It is noted that Nb/sub 3/Ir is not a high T/sub c/ superconductor. The thermoreflectance on the bulk samples V/sub 3/Si, V/sub 3/Ge and single crystal Cr/sub 3/Si were not performed because the samples were not in the form of thin films. The thermomodulation studies are correlated with the absorptance measurements in comparison ...

International Nuclear Information System (INIS)

The crystal structure, lattice strain due to the antiferromagnetic ordering, and magnetic form factor in the itinerant 5f compounds UTGa_5 (T=Ni, Pd, Pt) have been studied by neutron scattering. High-resolution powder diffraction revealed that the tetragonality of the U-Ga layers increases down to the series of the transition metal element T. The integrated intensities of the antiferromagnetic reflections can be well explained with the Neel-type structure for UNiGa_5, whereas UPtGa_5 has the antiferromagnetic stacking of the ferromagnetically ordered uranium moments in the c plane. In both compounds the uranium moments orient along the c axis with moments of 0.75(5) and 0.32(5) #mu#_B for UNiGa_5 and UPtGa_5, respectively. No magnetic peak could be observed in the powder diffraction pattern of UPdGa_5 due to the small magnetic moment less than the experimental sensitivity. The orbital contributions in the magnetic form ...

International Nuclear Information System (INIS)

Nanodimensional powders of cubic copper ferrite are synthesized by two-steps procedure of co-precipitation of copper and iron hydroxide carbonates, followed by mechanochemical treatment. X-ray powder diffraction, Moessbauer spectroscopy and temperature-programmed reduction are used for the characterization of the obtained materials. Their catalytic behavior is tested in methanol decomposition to hydrogen and CO and total oxidation of toluene. Formation of nanosized ferrite material is registered even after one hour of milling time. It is established that the prolonging of treatment procedure decreases the dispersion of the obtained product with the appearance of Fe2O3. It is demonstrated that the catalytic behavior of the samples depends not only on their initial phase composition, but on the concomitant ferrite phase transformations by the influence of the reaction medium. -- Graphical abstract: It is demonstrated that the catalytic behavior of the obtained copper ferrites depends not ...

International Nuclear Information System (INIS)

Denting studies have been undertaken in order to assess the influence of the most important parameters which could initiate corrosion of the carbon steel occurring in the tube-tube support plate crevices of some PWR steam generators. Tests have been carried out in model boilers where feedwater was polluted with sea or river water. Specific effects of chloride or sulfate and influence of oxygen content, magnetite addition and pH value were investigated. In magnetite prepacked crevices, denting is obtained within 1000 hrs for seawater pollution of 0.3 ppm chloride at the blowdown. In neutral chloride or in river water, denting is observed only with oxygen addition. Denting prevention is effective in the case of an on-line addition of phosphate, boric acid, or calcium hydroxide. For denting stopping, boric acid or calcium hydroxide is efficient even with a high seawater pollution. Soaks cannot stop denting if they are not followed by an on-line ...

Energy Technology Data Exchange (ETDEWEB)

Magnetic separation of several classes of antibiotics was investigated using electrochemical magnetic seeding. Electrocoagulation with a sacrificial anode followed by addition of magnetite particles was applied for the magnetic seeding of antibiotics. With electrochemical magnetic seeding using an iron anode, tetracycline antibiotics (oxytetracycline, chlortetracycline, doxycycline and tetracycline) and cephalosporin antibiotic (cefdinir) were rapidly removed from synthetic wastewater by magnetic separation using a neodymium magnet. Iron and aluminium anodes were suitable for magnetic seeding of the antibiotics. The results indicated that the ability of antibiotics to form strong complex with iron and aluminium allowed the higher removal by magnetic separation. This method would be appropriate for rapid treatment of antibiotics in wastewater.

KoreaScience (Korea)

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International Nuclear Information System (INIS)

Anticancer drug thyotepa (10 mg/ kg) hormonal compound thyroxine (40 mg / kg) and D3 vitamin (30,000 IU / kg) have been administrated simply or associated to Wistar rats bearing Walker carcinosarcoma. The chromatin (the complex of DNA and proteins from nuclei) has been extracted from Walker tumor and submitted to fast neutron beams produced by deuterons (13 MeV) on thick Be target at an IPNE U-120 Cyclotron, in doses of 5-100 Gy. Thermal transition of chromatin fluorescence intensity of chromatin-ethidium bromide complexes and intrinsic fluorescence of chromatin have been analysed. Association of thiotepa with thyroxine and D3 vitamin produced a diminution of chromatin lesions induced by the cytostatic. Thus in the effects of fast neutrons radiolysis in chromatin significant differences occurred. These results could help to improve the methodology of associated chemotherapy-radiotherapy in clinical applications. (author).

International Nuclear Information System (INIS)

Luminescence and reflection spectra as well as luminescence kinetics of the 1 mol% Sm3+-doped crystalline lanthanum magnesium meta borate (LaMgB5O10) and gadolinium magnesium meta borate (GdMgB5O10) were analyzed. Materials were synthesized by conventional solid state route and showed bright orange-red emission under UV excitation. Emission spectra contain sharp and well resolved Sm3+4G5/2#->#6HJ transitions indicating a strong crystal-field effect. In case of gadolinium compound energy transfer between Gd3+ and Sm3+ was detected. The luminescent kinetics of the Sm3+ in analyzed powders is characterized by single exponential decay and experimental values vary in the range 2.2-2.4 ms. - Research highlights: ? Phosphorescence of samarium-doped lanthanide magnesium meta borates. ? Bright and well resolved orange-red emission of Sm3+ under UV excitation. ? Energy transfer from Gd3+ to Sm3+ in gadolinium magnesium meta borate is observed. ? The ...

International Nuclear Information System (INIS)

Superconducting Cu-rich composites containing the A-15 compounds V_3Si or V_3Ga were made by the ''Tsuei'' process (melting into ingots followed by cold working and heat treatment). Superconducting transition temperatures of the composites were measured. X-ray diffraction analyses were performed. Microstructures were studied using both the optical metallograph and the scanning electron microscope. For some composites containing V_3Ga, the critical current densities as functions of transverse magnetic field up to 60 kG, and as functions of temperature from 4.2 to 12"0K were measured. It was found that the Tsuei process does not work for the composites containing V_3Si, but works satisfactorily for V_3Ga; reasons are discussed. Relations between measured properties and various metallurgical factors such as alloy compositions, cross-section reduction ratios, and heat treatment are discussed. The mechanism for the observed superconductivity in the ...

International Nuclear Information System (INIS)

Several dioxomolybdenum(VI) complexes of the schiff bases derived from salicylaldehyde, 2-hydroxy-1-naphthaldehyde, o-hydroxyacetophenone or pyridoxal and o-aminobenzylalcohol, o-aminophenol, o-hydroxybenzylamine, o-hydroxy(methylbenzyl)amine or 3-amino-2-naphthoic acid have been synthesized and characterized by elemental analysis, electrical conductance, molecular weight, IR and electronic spectral and magnetic susceptibility measurements. The schiff bases behave as dibasic, tridentate ligands and coordinate through ONO donor system forming complexes of the type MoO_2L.X (where LH_2=schiff base, X=H_2O or Ch_3OH). The compounds MoO_2L.Ch_3OH react with 2,2'-dipyridyl to form heterochelates of the type MoO_2L.dipyridyl. The complexes are non-electrolytes, monomers, diamagnetic and possess a cis-MoO_2 structure. The complexes exhibit a ligand-to-metal charge-transfer transition around 25000 cm"-"1. The complexes MoO_2L.X and MoO_2L.dipyridyl are ...

International Nuclear Information System (INIS)

The results of x-ray diffraction, dc magnetization, and 61Ni Moessbauer spectroscopy studies of the ternary arsenide CrNiAs are reported. This compound crystallizes in the orthorhombic Fe2P-type structure (space group P6-bar2m) with the lattice parameters a 6.1128(2) A and c = 3.6585(1) A. CrNiAs is a mean-field ferromagnet with Curie temperature TC = 171.9(1) K and the critical exponents ? 0.514(18), ? = 1.010(16), and ? = 2.922(10). The temperature dependence of the magnetic susceptibility above TC follows the modified Curie-Weiss law with a paramagnetic Curie temperature of 176.0(3) K and effective magnetic moment per transition metal atom of 2.42(1) ?B. The magnetic moment per formula unit at 4.2 K is found to be 1.114(33) ?B. The hyperfine magnetic field at 61Ni nuclei at 4.2 K of 41.5(1.0) kOe implies that the Ni atoms carry a magnetic moment of 0.15(3) ?B, and that the moment carried by the Cr atoms is 0.95(6) ?B. The Debye temperature ...

Science.gov (United States)

We present an x-ray magnetic circular dichroism (XMCD) study performed on both Ho{sub 6}Fe{sub 23} and Y{sub 6}Fe{sub 23} compounds as a function of the temperature. The combined analysis of both Fe K-edge and Ho L{sub 2,3}-edge XMCD spectra recorded through the magnetic compensation transition allows us to disentangle the thermal dependence of both Fe and Ho magnetic moments in Ho{sub 6}Fe{sub 23}. In addition, contributions from Ho ions to the Fe K-edge XMCD signals and, conversely, from Fe ions to the Ho L{sub 2,3}-edge XMCD spectra have been clearly identified. These extra contributions, arising from the strong Fe(3d)-Ho(5d) hybridization, have been isolated from the spectra and correlated with the magnetic state of both Ho and Fe ions surrounding the absorbing site. The influence of these contributions to the values of the orbital and spin moments derived by using sum rule analysis is also shown.

Energy Technology Data Exchange (ETDEWEB)

Mining lakes are of a world-wide challenging problem caused by the well known acid mine drainage (AMD) and the dynamics of it. In the past, there was no possibility to monitor these mining lakes for an investigation of chemical and biological parameters. But, in general, remote sensing methods are suitable for a monitoring of natural lakes, and now, at the first time, those can be used for a distinction of acid mining lakes in central Germany into different types. In acid mining lakes unusual absorption and scattering properties exist due to the water constituents which are quite different in their optical properties to those of natural lakes. The artificial lakes show high concentrations of metal ions and compounds. This fact was used to discriminate the mining lakes into initial stage, early stage, transitional state and late state. The result is a map of the area where the mining lakes are presented at their current stage. The present method ...

Energy Technology Data Exchange (ETDEWEB)

Lithium, with its strong reducing property and very low potential (-3.045 V/ENH), is one of the best material for electrodes. By combining lithium with an oxidizer, one can obtain an energy and electromotive force higher than with any other electrochemical couple. The density of lithium is low (0.534 g/cm{sup 3}) and thus, its specific capacity is higher than other classical anode materials. This article presents the technology of lithium batteries: 1 - presentation; 2 - negative electrodes: metallic lithium based, lithiated carbon based, transition metal compounds based negative electrodes; 3 - positive electrodes: 'low' voltage and 'high' voltage cathode materials; 4 - electrolytes: introduction, organic solvents and lithium salts-based electrolytes (case of the lithium anode battery, case of the lithium-ion battery), polymer electrolytes; 5 - metallic lithium anode and liquid electrolyte batteries: first ...

International Nuclear Information System (INIS)

The "2"0 "2"1 "2"2Ne("6Li, d)"2"4 "2"5 "2"6Mg reactions have been studied at a bombarding energy of 32 MeV. Alpha particle spectroscopic strengths have been extracted for several low-lying levels by a finite-range distorted wave analysis. These are compared with theoretical predictions. The agreement is good both for relative strengths to different levels within a nucleus and for ground-state strengths relative to the "1"6O("6Li, d) result. Strengths calculated using eigenfunctions determined in large shell-model computations agree well with pure symmetry SU(3) predictions. The "2"1Ne("6Li, d) angular distributions for transitions to the ground-state band of "2"5Mg are characterized by the lower of the two L-transfers allowed for populating each level. For the 3"+(5.24 MeV) unnatural parity level in "2"4Mg, a two-step calculation gives a better account of the data than does a compound nuclear calculation. (Auth.).

Science.gov (United States)

The utility of recording Raman spectroscopy under liquid nitrogen, a technique we call Raman Under Nitrogen (RUN), is demonstrated for ferrocene, uranocene and thorocene. Using RUN, low temperature (liquid nitrogen cooled) Raman spectra for these compounds exhibit higher resolution than previous studies and new vibrational features are reported. The first Raman spectra of crystalline uranocene at 77 K are reported using excitation from argon (5145 ) and krypton (6764 ) ion lasers. The spectra obtained showed bands corresponding to vibrational transitions at 212, 236, 259, 379, 753, 897, 1500, and 3042 cm-1 , assigned to ring-metal-ring stretching, ring-metal tilting, out-of-plane CCC bending, in-plane CCC bending, ring-breathing, C-H bending, CC stretching and CH stretching, respectively. The assigned vibrational bands are compared to those of uranocene in THF and thorocene. All vibrational frequencies of the ligands, except the 259 cm-1 ...

Energy Technology Data Exchange (ETDEWEB)

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 parameters in an ...

International Nuclear Information System (INIS)

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 model failed, ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared

Science.gov (United States)

Not Available

Energy Technology Data Exchange (ETDEWEB)

Short communication. 6 refs., 2 figs.

Science.gov (United States)

Polycrystalline powders of Na{sub 2x}Mn{sub 1-x}PS{sub 3} have been synthesized from layered MnPS{sub 3} material by successive ion-exchange intercalation of potassium and sodium ions. Their x-ray photoelectron spectroscopy (XPS) and x-ray excited Auger spectroscopy spectra have been measured at room temperature using Mg K{alpha} (1253.6 eV) x-ray source. In particular, the Mn, P, and S 2p and Na 1s and 2p core-level regions and the Na Auger KL{sub 23}L{sub 23} transition have been investigated. All the analyzed XPS core-level spectra display a single-peak structure, suggesting the absence of nonequivalent atoms of Na, Mn, P, and S. The manganese XPS spectrum shows, as observed in MnPS{sub 3} and in its cesium and potassium intercalation compounds, typical shake-up satellites, suggesting that the Mn-S bond is yet mainly ionic in nature. The comparison with the XPS spectra relative to MnPS{sub 3} and its potassium intercalation ...

International Nuclear Information System (INIS)

Monoclinic and trigonal Cr_5Te_8 show a transition into the ferromagnetic state with a Curie temperature T_c, which sensitively depends on the actual composition. Monoclinic samples exhibit a lower T_c despite their higher Cr content. This observation is explained on the basis of less effective ferromagnetic superexchange in the monoclinic compounds and the larger number of Cr atoms being antiferromagnetically coupled. Magnetization experiments performed at 5 K demonstrate that the compounds saturate already at rather low magnetic fields. In addition, small values are estimated for the coercitive field H_c as well as for the remanence magnetization both being typical for weak ferromagnetic materials. The values for the saturation magnetization amount to about 72% and 65% for monoclinic and trigonal Cr_5Te_8, respectively. These low values can partially be explained on the basis of antiferromagnetically coupled Cr(III) d"3 ...

Science.gov (United States)

This study examined the effect of sulfur-containing compounds on the storage stability of Jet A

International Nuclear Information System (INIS)

Moss-Schottky plots and photoelectrochemical measurements were made on films formed at different potentials on AISI 304 stainless steel in a borate/boric acid solution, pH 9.2. The results allowed the determination of the semiconductive properties and band structure of the films, which account for the existence of two kinds of films depending on the formation potential. For potentials below 0 V (SCE), the results point out for a film with an inverse spinel structure constituted by Cr-substituted magnetite with two donor levels. Above 0 V only one donor level is detected, which should be Fe"2 "+ on tetrahedral sites.

Energy Technology Data Exchange (ETDEWEB)

Red mud suspensions are studied as passivating agents for iron in alkaline chloride media. Red mud particles in alkaline media are negatively charged, and can absorb considerable amounts of protons without significant changes in pH. These particles adhere easily to an iron surface forming aggregates of heterogeneous shape, smaller than 10 {mu}mx10 {mu}m. These adhered particles recrystallise on potential cycling, and hinder metal dissolution and magnetite formation. Carbon steel samples passivated in red mud suspensions become resistant to corrosion in alkaline chloride media. Corrosion potential versus time records and impedance spectroscopy measurements allow formulating some hypotheses about the inhibiting mechanism.

International Nuclear Information System (INIS)

This report discusses the work done on EPRI program S149-1. In this program the feasibility of cleaning steam generators off line with organic chelants as a means of arresting denting corrosion was investigated. The rationale behind this program is to make use of those periods during which nuclear steam generators are in cold shutdown or wet layup to carry out a low-temperature soak with a combined chelant-inhibitor solution in order to dissolve some of the magnetite which has built up in crevices and to concomitantly remove entrained corrodents such as chloride ion. It was hoped that these soaks would be effective in reducing carbon steel support plate corrosion which produces tube denting.

UK PubMed Central (United Kingdom)

In the American educational system, school transitions are frequent and predictable, but they can disrupt student functioning across developmental domains. How students experience school transitions...Full Text Available

CERN Document Server

The phase transition is a performance measure of the sparsity-undersampling tradeoff in compressed sensing (CS). This letter reports, for the first time, the existence of an exact phase transition for the $\\ell_1$ minimization approach to the complex valued CS problem. This discovery is not only a complementary result to the known phase transition of the real valued CS but also shows considerable superiority of the phase transition of complex valued CS over that of the real valued CS. The results are obtained by extending the recently developed ONE-L1 algorithms to complex valued CS and applying their optimal and iterative solutions to empirically evaluate the phase transition.

UK PubMed Central (United Kingdom)

This paper examines theoretically the effects that restraints on the tertiary structure of a superhelical DNA domain exert on the energetics of linking and the onset of conformational transitions. The...Full Text Available

International Nuclear Information System (INIS)

Apart from conventional phase transitions driven by the thermal effects, quantum phase transitions generated by quantum fluctuations have their own mechanisms that are reflected in critical phenomena. Quantum phase transitions have an origin from spontaneous symmetry breaking commonly to thermal phase transitions. Even in this case, inherent quantum fluctuations substantially modify and yield new aspects. Quantum phase transitions have, however, another mechanism caused by topology changes, which gives completely new characters. Recently, a mechanism which connects these two has been found. Proimities from first-order transitions and phase separatins as well as from multiphase coexistence also generate characteristic and unconventional quantum criticalities. Understanding novel quantum criticalities offers a firm basis of recent active researches on fields such ...

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This report describes the evaluation results for new Orion VII buses at NYCT with CNG propulsion and new hybrid propulsion.

UK PubMed Central (United Kingdom)

ObjectiveThis study investigated transitions between drinking and nondrinking during the first 12 months following treatment and whether transitions in posttreatment...Full Text Available

Science.gov (United States)

Excitonic transitions in metalorganic vapor phase epitaxially grown In[sub [ital x

Energy Technology Data Exchange (ETDEWEB)

Conventional eddy current bobbin probes are known to be ineffectual in detecting circumferential cracks in tubing. Multi-pancake and/or rotating pancake probes are required to detect circumferential cracks. It has recently been demonstrated in CANDU steam generator tubes, with deformation, ferromagnetic deposits, and copper deposits, that multi-channel probes with transmit-receive (T/R) coils are superior to those using surface impedance coils. Unlike rotating probes, the design of a new probe denoted as C3 permits fast, single-scan inspection of a full-length tube at inspection speeds comparable to conventional bobbin probes. Since 1992, the probe has been used routinely for steam generator in-service inspection at 4 CANDU plants. Defective tubes have been plugged and the units returned to service, and they continue to operate without leaks. This paper describes the basic features of T/R surface probes. Two-dimensional voltage diagrams showing computer-derived probe response to ...

International Nuclear Information System (INIS)

Computer programs have been written to allow the analysis of different types of eddy-current probes and their performance under different steam generators test conditions. The probe types include the differential bobbin probe, the absolute bobbin probe, the pancake probe and the reflection probe. The generator test conditions include tube supports, copper deposits, magnetite deposits, denting, wastage, pitting, cracking, and intergranular attack. These studies are based mostly on computed values, with the limited number of test specimens available used to verify the computed results. The instrument readings were computed for a complete matrix of the different test conditions, and then the test conditions determined as a function of the readings by a least-squares technique. A comparison was made of the errors in fit and instrument drift for the different probe types. The computations of the change in instrument reading due to the defects have led to an inversion ...

Science.gov (United States)

The study of the intrinsic behavior of high transition temperature copper-oxide superconductors (HTSC) has proven to be challenging because of the extreme sensitivity of their transport properties on material quality. These compounds are characterized by a high degree of structural and electrical anisotropy, and a very short superconductive coherence length of the same order as the size of the crystalline unit cell (~5-30 A). As a result, microscopic defects such as oxygen vacancies, cationic disorder, and the presence of minute impurities have a significant effect on electrical transport in these materials. Therefore, much effort has been expended in synthesizing sizable samples that are homogeneous, well characterized, and emenable to the study of the anisotropic properties of the HTSC. We have demonstrated that thin films of HTSC compounds such as rm YBa_2Cu_3O_{7 -delta}, which is a 92 K superconductor, can be ...

Science.gov (United States)

No Abstract Available

International Nuclear Information System (INIS)

... beta spectrometers decay energy-level transitions k conversion l conversion

KoreaScience (Korea)

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International Nuclear Information System (INIS)

... fields magnetic moments neel temperature neutron diffraction order-disorder

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

Data on the reactions of thiocyanogen and thiocyanogen halides with unsaturated compounds are systematised. The kinetic and stereo- and regiochemical regularities of these reactions are analysed. The bibliography includes 81 references.

Energy Technology Data Exchange (ETDEWEB)

The invention relates to a method for purifying a gas mixture containing at least one undesirable gas compound utilizing certain sulfonamide or sulfamide solvents.

UK PubMed Central (United Kingdom)

The antibacterial activities of different nitroheterocyclic compounds were assessed by an agar dilution method against aerobic, microaerophilic, and anaerobic bacteria. Nitronaphthofurans inhibited...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The sharp, temperature induced, continuous valence transition in EuPd/sub 2/Si/sub 2/ is drastically changed by doping with Sn at the Si site up to 5 at.%. Only a first order valence transition occurs for a 3% Sn doped sample and the 2/sup +/ component which survives the valence transition orders magnetically at 4.2 K. No valence transition at all occurs for a 5% Sn doped sample right up to 1.9 K and magnetic ordering sets in around 30 K.

Energy Technology Data Exchange (ETDEWEB)

The 8 papers in the report deal with the following areas: Introduction to diesel particulate emissions, alternative fuels, and the transit industry; Technical problems and policy issues associated with the 1991 bus emissions standards; Reducing transit bus emissions: comparative costs and benefits of methanol, particulate traps, and fuel modification; Effects of applying emissions averaging, trading, and banking to transit buses; Strategic review of heavy-duty engine emission regulations and alternate fuels; Meeting bus emissions standards--a perspective; Economic evaluation of bus maintenance contracting; Objectives for a transit-bus-fleet management data, information, and knowledge exchange.

International Nuclear Information System (INIS)

Magnetic excitation in coupled multispin system is studied theoretically focusing on Cu_2Fe_2Ge_4O_1_3 and Cu_2CdB_2O_6 as typical examples of such system. These compounds consist of spin dimer and spin monomer parts and show an antiferromagnetic phase transition at low temperatures due to the spin monomer part. A multispin containing a spin dimer and spin monomers is treated as a basis unit. The multispin forms a spin multiplet and its energy levels are separated into high and low regions reflecting the characteristic energies of the dimer and monomer parts. We regard the system as interacting multispins and apply an extended Holstein-Primakoff theory by introducing bosons for each energy level of a spin multiplet. In the low-energy region, the obtained magnon dispersion and dynamical spin correlation function agree quantitatively with experimental results of inelastic neutron scattering performed in Cu_2Fe_2Ge_4O_1_3. Analyzing dynamical spin ...

Energy Technology Data Exchange (ETDEWEB)

The ternary transition metal chalcogenides A[sub x]M[sub 6]X[sub 8] (A = Tl, K; M = V, Ti; X = S, Se) build up a three dimensional framework with large hexagonal channels running parallel to the crystallographic c-axis. The electropositive elements thallium or potassium are confined within these channels. It is possible to remove the Tl or K atoms via a chemical redox reaction with an I[sub 2]/CH[sub 3]CN solution or with H[sub 2]O. Using SEM it is demonstrated that the host matrix V[sub 6]S[sub 8]'' is only slightly affected by the redox agent. In contrast the host matrix Ti[sub 6]Se[sub 8]'' of Tl[sub x]Ti[sub 6]Se[sub 8] reacts with the I[sub 2]/CH[sub 3]CN solution. The results of the EDXS analyses clearly show that the removal of the electropositive elements proceeds only along the large channels and not through the host matrix. (orig.)

International Nuclear Information System (INIS)

A study of the magnetic properties and the heat capacity as functions of temperature and magnetic field of two ternary carbides RNiC_2, where R=La and Ce, confirms that LaNiC_2 becomes superconducting at T_c=2.7thinspK, and that CeNiC_2 orders antiferromagnetically below 18thinspK. LaNiC_2 is a conventional superconductor with a critical field of 900 Oe at T=2thinspK. CeNiC_2 obeys the Curie-Weiss law between 50 and 300thinspK showing the nearly full Ce"3"+ magnetic moment, p_e_f_f=2.47(1)#mu#_B, and has a negative paramagnetic Weiss temperature #THETA#_p=-18.3(8)thinspK. A low net magnetic moment in the ordered state, which is far from saturation in a magnetic field of 5thinspT, is consistent with an antiferromagnetic ground state. Below 20thinspK CeNiC_2 shows multiple-step magnetic transitions at 18, 10, and 2.4thinspK. Both LaNiC_2 (in the normal state) and CeNiC_2 have the same electronic heat capacity, #gamma#=6.5(2)thinspmJ/molthinspK"2, which is typical for ...

Energy Technology Data Exchange (ETDEWEB)

Anionic complexes of transition metals were stabilized in aqueous solutions containing high concentrations of various short-chain quaternary ammonium salts. Compounds with longer paraffin chains were effective in much less concentrated solution. Complex ions were detected spectrophotometrically. FeCl/sub 4//sup -/, which is usually formed in concentrated HCl, was the predominant Fe(III) complex in 30 m choline chloride containing only 0.12 M HCl. A yellow transitory Tc(VII) chloro-addition intermediate, formed in the reduction of TcO/sub 4//sup -/ by concentrated HCl, was stabilized when the solution also contained 25 m choline chloride. Its spectrum, as well as the isolation of an already known Tc(VII) bipyridyl complex, is reported. Concentrated organic electrolytes also stabilized Tc(V) oxide halides against disproportionation and Tc(IV) hexahalides against hydrolysis. Halochromates of Cr(VI) were formed and stabilized in dilute acid ...

International Nuclear Information System (INIS)

We review the current status of Andreev reflection spectroscopy on the heavy fermions, mostly focusing on the case of CeCoIn5, a heavy-fermion superconductor with a critical temperature of 2.3 K. This is a well-established technique to investigate superconducting order parameters via measurements of the differential conductance from nanoscale metallic junctions. Andreev reflection is clearly observed in CeCoIn5 as in other heavy-fermion superconductors. Considering the large mismatch in Fermi velocities, this observation seemingly appears to disagree with the Blonder-Tinkham-Klapwijk (BTK) theory. The measured Andreev signal is highly reduced to the order of maximum ?13% compared to the theoretically predicted value (100%). The background conductance exhibits a systematic evolution in its asymmetry over a wide temperature range from above the heavy-fermion coherence temperature down to well below the superconducting transition temperature. Analysis of the ...

Energy Technology Data Exchange (ETDEWEB)

The performance of four different organic coating systems applied to carbon and weathering steel coupons has been assessed in this investigation. applied on the surface of carbon steel and weathering steel coupons. The coupons have been evaluated using five different tests, three field tests and two accelerated tests. The field tests were carried out at three atmospheric stations, located at COSIPA in Cubatao-SP, at Alto da Serra in Cubatao-SP and at Paula Souza in Sao Paulo city. The accelerated tests consisted of (a) exposure to alternate cycles of ultraviolet radiation/condensation combined with salt spray cycles (UVCON combined with Salt Spray) and of (b) exposure to alternate cycles of ultraviolet radiation/condensation combined with the Prohesion test. The performance of the coatings was assessed by visual observation and photographs, using a method based on ASTM D-610, ASTM D-714 and ASTM-1654 standards to rank them. The oxide phases formed on the surfaces of the non-coated ...

KoreaScience (Korea)

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Science.gov (United States)

... biologically important compounds is sharply lowered with passage of the solutions to the cell an organ, where their sensitivity ...

CERN Document Server

A Multi-Channel Algebraic Scattering (MCAS) theory is presented with which the properties of a compound nucleus are found from a coupled-channel problem. The method defines both the bound states and resonances of the compound nucleus, even if the compound nucleus is particle unstable. All resonances of the system are found no matter how weak and/or narrow. Spectra of mass-7 nuclei and of {}^{15}F, and MCAS results for a radiative capture cross section are presented.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

... biological variability body distribution kidneys labelled compounds lead 203

KoreaScience (Korea)

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KoreaScience (Korea)

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International Nuclear Information System (INIS)

... odd nuclei organic compounds radiation effects radioisotopes synthesis

International Nuclear Information System (INIS)

... compounds plants radiation effects radioisotopes reaction kinetics trees

Wastenet

...contributions from the following fields: Catalytic elimination of environmental pollutants, such as nitrogen oxides, carbon monoxide, sulfur compounds, chlorinated and other organic compounds, ...contributions from the following fields: Catalytic elimination of environmental pollutants, such as nitrogen oxides, carbon monoxide, sulfur compounds, chlorinated and other organic compounds, ...

International Nuclear Information System (INIS)

The magnetic scattering spectra of RAgSb_2 (R = Ho, Er, Tm) intermetallic compounds are measured and their crystal electric field parameters are determined using inelastic neutron scattering. It is revealed that the ground state is a nonmagnetic singlet for the HoAgSb_2 compound, a Kramers doublet with a strongly anisotropic g factor for the ErAgSb_2 compound, and a quasi-doublet (random doublet) characterized by an extremely anisotropic g factor for the TmAgSb_2 compound. The exchange interaction is estimated in the molecular field approximation. The magnetic properties of the RAgSb_2 compounds are analyzed in terms of the energy level schemes and eigenfunctions determined in this study. The calculated anisotropic magnetic susceptibilities for all compounds are in good agreement with the experimental data obtained for single crystals.

International Nuclear Information System (INIS)

We demonstrate detection of a single core-shell magnetite-silica nanoparticle (outer diameter #approx#120 nm, moment #approx#10"4#mu#_B) using an Nb dc superconducting quantum interference device (SQUID) with the loop size of 350 nm operational at T < 10 K. The system noise was minimized down to 0.2 #mu##PHI#_0 Hz"-"1"/"2 using a cryogenic SQUID series array pre-amplifier. Initial measurements of an individual magnetic nanoparticle were performed and a clear change of the noise spectra of the nano-SQUID was detected at low frequencies in the presence of the nanoparticle. Similar behaviour was confirmed with an FePt nanoparticle with a larger magnetic moment (diameter #approx#150 nm, moment #approx#10"6#mu#_B). Thus, we demonstrate a magnetic sensor based on a dc nano-SQUID and enabling detection of small moments (potentially down to a few electron spins). Such a sensor is of considerable significance for nanomagnetic metrology and quantum information processing ...

Energy Technology Data Exchange (ETDEWEB)

Computer programs have been written to allow the analysis of different types of eddy-current probes and their performance under different steam generator test conditions. The probe types include the differential bobbin probe, the absolute bobbin probe, the pancake probe and the reflection probe. The generator test conditions include tube supports, copper deposits, magnetite deposits, denting, wastage, pitting, cracking and IGA. These studies are based mostly on computed values, with the limited number of test specimens available used to verify the computed results. The instrument readings were computed for a complete matrix of the different test conditions, and then the test conditions determined as a function of the readings by a least-squares technique. A comparison was made of the errors in fit and instrument drift for the different probe types. The computations of the change in instrument reading due to the defects have led to an inversion'' ...

Energy Technology Data Exchange (ETDEWEB)

This project evaluated the feasibility of using a low-concentration (approx. 0.5 wt %) chemical cleaning process to remove corrosion product deposits from steam generator surfaces and magnetite from tube-to-support plate crevices of PWR steam generators. The primary objective was to develop a dilute process that could be safely applied at scheduled intervals, such as during normal refueling outages, to maintain a clean operating condition in the steam generator. The dilute chemical cleaning process developed in this project was demonstrated successfully on two model generators which were operated on faulted chemistry by DOE/CRC at Commonwealth's State Line Facility. Unit 5 was cleaned after 48 days of operation with 1% seawater fouling, and Unit 6 was cleaned after 112 days of operations with Lake Michigan water. This report describes work leading to the model generator cleaning demonstrations and provides details of the cleaning operation for each model ...

Energy Technology Data Exchange (ETDEWEB)

The magnetic fluid is a colloidal suspension of magnetite in kerosene, prepared by a low-cost process. Separation is accomplished in an open trough filled with magnetic fluid. A magnetic field is established in the fluid, by energizing an electromagnet having poles on each side of the trough. Due to the design of the magnet poles and air gaps, the magnetic field is strongest at the bottom, about 10,000 oersteds, and uniformly decreases in strength to about 2000 oersteds at the top of the fluid. Therefore, the magnetic field gradient increases with depth. The magnetic force attracts the entire separation medium (magnetic fluid) creating a reaction force of equal magnitude and acting in the opposite direction. This reaction created within a magnetic fluid/magnetic field combination is called a magnetic levitation force. It increases with the field strength. In this case because the magnetic field is strongest at the bottom of the trough, the magnetic levitation force ...

CERN Document Server

A phase transition of gas-liquid type with an upper critical point is examined which arises in a model of charges of one sign on compensating background (OCP). The phase transition parameters are dependent on the detailed assumptions about the compressibility of the background, but the occurrence of this transition is independent on the background equation of state. In the electron-gas model ('jellium'), this transition appears to rule out Wigner crystallization. A variational principle in statistical mechanics is used to derive so-called Double-OCP model for a superposition of two one-component plasma models for charges of opposite sign. The free energy of this model sets an upper bound to that of a real plasma. Situations are discussed where this transition should manifest itself in anomalies in the approximate description of a non-ideal plasma.

International Nuclear Information System (INIS)

A reaction of aqueous-methanol solutions of thiocarbazide and salycilic aldehyde, taken in a molal ratio of 1:2 on the matrix of oxovanadium(VO) in the presence of aqueous ammonium results in a coordination compound of the VC_1_5H_1_2N_4O_3S composition. Similar compounds are obtained with salts of nickel(2) and copper(2). Complexes of oxovanadium(4) and copper(2) have effective magnetic moments normal for systems with a spin of 1/2. The compound with nickel is diamagnetic. These data agree with the configuration of the coordination compounds obtained.

Energy Technology Data Exchange (ETDEWEB)

Magnetite nanoparticles with high self-heating capacity and low toxicity characteristics are a promising candidate for cancer hyperthermia treatment. In order to achieve minimum dosage to a patient, magnetic nanoparticles with high heating capacity are needed. In addition, the influence of physiological factors on the heat capacity of a material should be investigated in order to determine the feasibility. In this study, magnetite nanoparticles coated with lauric acid were prepared by co-precipitation of Fe{sup 3+}:Fe{sup 2+} in a ratio of 2:1, 5:3, 3:2, and 4:3, and the pH was controlled using NaOH. Structural and magnetization characterization by means of X-ray diffractometry (XRD) and a superconducting quantum interference device (SQUID) revealed that the main species was Fe{sub 3}O{sub 4} and further showed that most of the nanoparticles exhibited superparamagnetic properties. All of the magnetic nanoparticles showed a specific absorption ...

International Nuclear Information System (INIS)

The two-phase flow regime transition in a large diameter (I.D.=200mm) vertical pipe was experimentally investigated using a dual-sensor optical probe. The flow transitions from bubbly to chum without an intermediate slug flow regime as the air flow rate is increased. The transition boundaries developed for bubbly to slug flow in small diameter pipes are compared to the bubbly to chum flow transition of the present experiment. The bubbly to chum transition occurs at a void fraction of about 0.15 compared to 0.25 for bubbly to slug transition in small diameter pipes. The radial distribution of bubble diameter, bubble frequency, bubble velocity and local void fraction were obtained using a dual-sensor optical probe at different flow conditions. The Probability Density Function (PDF) and Cumulative Distribution Function (CDF) of the bubble velocity and size are used ...

UK PubMed Central (United Kingdom)

Epithelial-mesenchymal transition (EMT) has emerged in recent years as an important process in the development of organ fibrosis in many human diseases. Our previous experience in a nonhuman primate...Full Text Available

UK PubMed Central (United Kingdom)

Agriculture is a specialized form of symbiosis that is known to have evolved in only four animal groups: humans, bark beetles, termites, and ants. Here, we reconstruct the major evolutionary transitions...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The hyperfine splitting in the rotational levels of the C/sub 2/H molecule is calculated as far as N = 10. Line strengths and transition probabilities are determined for permitted transitions with DN = 1, DF = 0, +- 1.

UK PubMed Central (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

This work concerns the development of a methodology the objective of which is to characterize and diagnose two-phase flow regime transitions. The approach is based on the fundamental assumption that a transition flow is less stationary than a flow with an established regime. During the first time, the efforts focused on: (1) the design and construction of an experimental loop, allowing to reproduce the main horizontal two-phase flow patterns, in a stable and controlled way; (2) the design and construction of an electrical impedance probe, providing an imaged information of the spatial phase distribution in the pipe; and (3) the systematic study of the joint time-frequency and time-scale analysis methods, which permitted to define an adequate parameter quantifying the unstationarity degree. During the second time, in order to verify the fundamental assumption, a series of experiments were conducted, the objective of which was to demonstrate the ...

Energy Technology Data Exchange (ETDEWEB)

A single-crystal x-ray study under pressure reveals a phase transition from an in-plane 2x2 commensurate potassium superstructure to a new ..sqrt..3x..sqrt..3 commensurate superstructure. This is the first such transition to be observed; it is related to the recently discovered staging transition of KC/sub 8/ under pressure. In addition this staging transition was observed to occur more slowly and at much lower pressures than in the reported neutron-scattering experiment on highly oriented pyrolytic graphite samples. 13 references, 2 figures.

International Nuclear Information System (INIS)

... transitions lutetium 175 target mev range 10-100 multipolarity neutrons parity

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

The wide-angle neutron diffractometer recently installed at the HFIR has the capability of performing time-resolved or time-slicing measurements. One of the interesting problem areas the authors have explored using this time-slicing function of the diffractometer is the kinetics of structural changes occurring after a temperature jump across a value at which a first-order phase transition occurs. Two measurements of this sort have been carried out: the phase III to II transition in RbNO_3 and the transition between the alpha and beta phases in Sn.

International Nuclear Information System (INIS)

... alpha reactions angular distribution energy-level transitions iridium 185 iridium

Energy Technology Data Exchange (ETDEWEB)

The normal-incommensurate phase transition in K2ZnCl4 was studied by neutron scattering measurements. A well-defined soft phonon behavior was not observed above the normal-incommensurate transition temperature of Tsub(i)=288C. Diffuse scattering develops around(h,0,1 +- 0.3) as temperature approaches Tsub(i) from above, and the peak intensity obeys a Curie-Weiss law above Tsub(i). The results indicate that the normal-incommensurate phase transition in K2ZnCl4 can be interpreted as an order-disorder process.

International Nuclear Information System (INIS)

... comparative evaluations energy-level transitions half-life internal conversion

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

... collective model hamiltonians iridium 187 matrix elements nuclear cores

International Nuclear Information System (INIS)

Transition rates for electrons in the superheavy elements Z = 114, 126, 134, 145, 164 and 173 are calculated. K, L and M-shells are considerd as final states. The 2s - 1s stransition of multipolarity M1 is dominant for Z = 173 with a transition time of 10"-"1"8s. The radial expectation values and #sq root# are given. (orig.).

International Nuclear Information System (INIS)

A Bianchi type-IX cosmological model has been found as a solution of Einstien's vacuum field equations with a cosmological constant. The solution represents a rotating generalziation fo the de Sitter universe. This universe shows a transition to exponential expansion and the vorticity begins to decay exponentially at the grand-unified-theory time. The point of time for this transition is independent of the magnitude of the vorticity. During the Guth inflationary era the vorticity decays by a factor of the order 10"-"1"4"2.

Energy Technology Data Exchange (ETDEWEB)

The transition radiation detector (TRD) for the D{Phi} experiment is currently in operation at Fermilab. Transition radiation production, which has been clearly observed in the collider data, makes the TRD a valuable tool to discriminate electrons and hadrons. We describe an algorithm based on the truncated energy, and illustrate its use for top signal and background. (authors). 7 refs., 6 figs., 2 tabs.

CERN Document Server

We report an uncertainty evaluation of an optical lattice clock based on the $^1S_0\\leftrightarrow^3P_0$ transition in the bosonic isotope $^{174}$Yb by use of magnetically induced spectroscopy. The absolute frequency of the $^1S_0\\leftrightarrow^3P_0$ transition has been determined through comparisons with optical and microwave standards at NIST. The weighted mean of the evaluations is $\

Energy Technology Data Exchange (ETDEWEB)

The partial oxidation of 1,3-butadiene has been investigated over VMoO catalysts synthesized by sol-gel techniques. Surface areas were 9-14 m{sup 2}/g, and compositions were within the solid solution regime, i.e. below 15.0 mol % MoO{sub 3}/(MoO{sub 3} + V{sub 2}O{sub 5}). Laser Raman Spectroscopy and XRD data indicated that solid solutions were formed, and pre- and post-reaction XPS data indicated that catalyst surfaces contained some V{sup +4} and were further reduced in 1,3-butadiene oxidation. A reaction pathway for 1,3-butadiene partial oxidation to maleic anhydride was shown to involve intermediates such as 3,4-epoxy-1-butene, crotonaldehyde, furan, and 2-butene-1,4-dial. The addition of water to the reaction stream substantially increased catalyst activity and improved selectivity to crotonaldehyde and furan at specific reaction temperatures. At higher water addition concentrations, furan selectivity increased from 12% to over 25%. The catalytic effects of water addition were ...

Science.gov (United States)

One-electron reduction of the square-planar nickel precursor (PNP)NiCl ( 1) (PNP (-) = N[2-P(CHMe 2) 2-4-methylphenyl] 2) with KC 8 effects ligand reorganization of the pincer ligand to assemble a Ni(I) dimer, [Ni(mu 2-PNP)] 2 ( 2), containing a Ni 2N 2 core structure, as inferred by its solid-state X-ray structure. Solution magnetization measurements are consistent with a paramagnetic Ni(I) system likely undergoing a monomer dimer equilibrium. The room-temperature and 4 K solid-state X-band electron paramagnetic resonance (EPR) spectra display anisotropic signals. Low-temperature solid-state X-band EPR data at 4 K reveal rhombic values g z = 1.980(4), g x = 2. 380(4), and g y = 2.225(4), as well as a forbidden signal at g = 4.24 for the Delta M S = 2 half field transition, in accord with 2 having two weakly interacting metal centers. Utilizing an S = 1 model, full spin Hamiltonian simulation of the low-temperature EPR spectrum on the solid sample was achieved by ...

CERN Document Server

Classic and recent results for gauge effects on the properties of the normal-to-superconducting phase transition in bulk and thin film superconductors are reviewed. Similar problems in the description of other natural systems (liquid crystals, quantum field theory, early universe) are also discussed. The relatively strong gauge effects on the fluctuations of the ordering field at low spatial dimensionality D and, in particular, in thin (quasi-2D) films are considered in details. A special attention is paid to the fluctuations of the gauge field. It is shown that the mechanism in which these gauge fluctuations affect on the order of the phase transition and other phase transition properties varies with the variation of the spatial dimensionality D. The problem for the experimental confirmation of the theoretical predictions about the order of the phase transitions in gauge systems is discussed.

British Library Electronic Table of Contents (United Kingdom)

The atomic mechanism of a glass-to-liquid transition in a monatomic Lennard-Jones (LJ) glass was studied using the molecular dynamics (MD) method. Glassy models were heated up from low temperature at two different heating rates and a glass-to-liquid transition found to occur at the higher heating rate. The temperature dependence of the potential energy, mean-squared-displacements (MSD) of the atoms and the self-intermediate scattering function indicate clearly that a glass transition occurs in the system. The atomic mechanism of the glass-to-liquid transition was investigated by analyzing the spatio-temporal arrangement of liquid-like atoms in the system upon heating. Liquid-like atoms were detected using the Lindemann-melting-like criterion. Upon heating, liquid-like atoms occur at temper...

Energy Technology Data Exchange (ETDEWEB)

This report will be revised upon completion of current testing investigating the radiolytic stability of additional energetic materials and the analysis of tank farm samples for volatile and semi-volatile organic compounds.

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The present invention relates to a method of acidizing a subterranean formation or well bore employing an acidic solution containing a corrosion inhibitor composition comprising an inhibiting effective amount of an acetylenic alcohol, a quaternary ammonium compound, an aromatic hydrocarbon and an antimony compound.

UK PubMed Central (United Kingdom)

Iron is a central element in the metabolism of normal and malignant cells. Abnormalities in iron and ferritin expression have been observed in many types of cancer. Interest in characterizing iron compounds...Full Text Available

International Nuclear Information System (INIS)

A brief review is given of the nature of lattice instabilities in high-T/sub c/ superconductors. The Frohlich instability in A-15 compounds is indicated to be a microdomain which acts as an embryo for the Martensitic transformations in these compounds.

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The inhibiting effects of two mineral compounds on corrosion of nickel in phosphoric acid (H[sub 3]PO[sub 4]) polluted by sulfide ions (S[sup 2[minus

UK PubMed Central (United Kingdom)

GR99060 and GR99062 are representatives of a series of 1,2,4-triazino[5,6-b]indole compounds. This series possessed broad-spectrum antifungal activity in vitro. The MIC ranges of the two compounds were...Full Text Available

UK PubMed Central (United Kingdom)

From Toki-shakuyaku-san, an herbal formulation for “cleansing stagnated blood,” a key gene regulatory compound was purified and identified through a screening based on DNA microarray...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared

Energy Technology Data Exchange (ETDEWEB)

The objectives of this project were to develop feasible synthetic routes to produce (1) 4(4{prime}-hydroxy-5{prime}6{prime},7{prime}8{prime}-tetrahydro-1{prime}-naphthylmethyl)-6-methyldibenzothiophene, and (2) a 1-hydroxynaphthalene-dibenzothiophene polymer. These compounds are thought to be representative of sulfur containing molecules in coal. The program was divided into two technical tasks. Unfortunately, the attempted syntheses of these compounds was unsuccessful due to their unusual reactivities. Attempted synthetic routes and possible future routes are described, and Appendix A lists the compounds that were synthesized during this program.

DEFF Research Database (Denmark)

Udgivelsesdato: 2002-Aug

International Nuclear Information System (INIS)

... atp-ase azido compounds biochemical reaction kinetics endoplasmic reticulum

International Nuclear Information System (INIS)

Portuguese 2004 [1 p.] Brazil Souza Filho, Paulo Artur Coelho de

British Library Electronic Table of Contents (United Kingdom)

Abstract Silicates are one of the most important classes of compounds on this planet, and more than 1000 silicates have been identified in the mineral kingdom. Additionally, several hundreds of artificial silicates have been synthesized. The substitution of oxygen by nitrogen leads to the structurally diverse and manifold class of nitridosilicates. Silicon nitride, one of the most important non-oxidic ceramic materials, is the binary parent compound of nitridosilicates, and it symbolizes the inherent material properties of these refractory compounds. However, prior to the last decades, a broad systematic investigation of nitridosilicates had not been accomplished. In the meantime, these and related compounds have reached a remarkable level of industrial application. This review illustrates...

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

... carrier-free isotopes hafnium compounds irradiation protons solvent extraction

British Library Electronic Table of Contents (United Kingdom)

Pilot industrial-scale testing of TSK-25 and TSK-10 compounds produced by NPP Tekhmet has been performed at Ruspolimet for siphon casting of 0.7?1.5-metric-ton ingots which are broader on the top (?flowers??) used for production of all-rolled rings; this is as an alternative to the existing process of pouring the steel into molds lubricated with petrolatum. The evaluation tests led to recommendation of the TSK-10 compound for industrial-scale testing; use of this compound enabled the petrolatum-lubricated steel casting process to be abandoned, thereby improving working conditions, and reducing rejects of the all-rolled ring products.

International Nuclear Information System (INIS)

Certain radioiodine containing esters useful as brain imaging agents are disclosed. The formula of these compounds are presented.

Science.gov (United States)

... Descriptors : *Combustible cartridge cases, *Water repellents, *Protective coatings, *Patents, Silica gel, Aluminum compounds, Binders ...

Energy Technology Data Exchange (ETDEWEB)

Certain radioiodine containing amides useful as brain imaging agents are disclosed. The compounds of the subject invention are represented by the formula

Science.gov (United States)

Nitrogens, Sulfurs, Isotopes, and Hydrocarbons Gases Elements Ions and Inorganic Acids Organic Compounds Co-eluting Organics Hopanes, Cholestanes, and Sterols Pesticides,...

Energy Technology Data Exchange (ETDEWEB)

Based on the activation theory of alkali and sulfate, the influence of compound admixtures on the properties of high-content slag cement was studied by testing the strength, pore structure, hydrates, and microstructure, Test results show that compound admixtures can obviously improve the properties of high-content slag cement. The emphasis of the present research is two-fold: substituting gypsum with anhydrite and calcining gypsum. These both can improve early and later performance.

Energy Technology Data Exchange (ETDEWEB)

The bibliography contains citations concerning the properties of tantalum and tantalum compound films formed by sputtering techniques. Topics include processes, and electrical, magnetic, and dielectric properties of the sputtered films. Tantalum compounds studied include nitrates, oxides, and aluminides. The structural properties of sputtered films are also discussed. (Contains a minimum of 105 citations and includes a subject term index and title list.)