WorldWideScience
1

Safe hole trapping, light soaking and secondary photocurrent transients in amorphous silicon  

International Nuclear Information System (INIS)

A new analysis is developed for long secondary photocurrent transients which gives the distribution of trapped holes in valence band tail states. Thermally assisted tunneling to dangling bonds is implicated as the rate limiting step in hole-recombination. Light-soaking causes the energetically deeper hole traps with the longer residence times to be lost first and in the same number as would be expected for the increase in dangling bonds; This result supports a model which has hole trapping in valence tail states as a precursor to light induced dangling bonds.

1988-09-26

2

K_#beta#/K_#alpha# X-Ray Intensity Ratio Studies on the Valence Electronic States of 3d-Transition Metals in some of their Compounds  

International Nuclear Information System (INIS)

Our studies on K#beta#/K#alpha# X-ray intensity ratios of some of the technologically important 3d-transition metal compounds have been reviewed. Comparison of the experimental results with single-configuration Dirac-Fock calculations provided important information on the valence states of the transition metals in various compounds, which can be helpful in understanding the nature of bonding in the compounds. (author)

2000-02-01

3

First-principles nonlocal-pseudopotential approach in the density-functional formalism. II. Application to electronic and structural properties of solids  

International Nuclear Information System (INIS)

We apply our previously developed first-principles nonlocal pseudopotentials (obtained for all atoms of rows 1--5 in the Periodic Table) to study self-consistently the electronic structure of Si and Ge and the transition metals Mo and W. For Si and Ge we find that the first-principles pseudopotentials yield valence-band states in good agreement with the empirically adjusted pseudopotential and photoemission data, whereas the low conduction-band states appear to be consistently lower in energy due apparently to incomplete cancellation of the self-interaction effects. The calculated x-ray scattering factors (obtained by core orthogonalization of the pseudo-wave-functions) are in excellent agreement with experiment. The self-consistent valence charge density shows a distinct elongation of the covalent bond along the internuclear axis, in good agreement with the experimentally synthesized density. The systematic deviations of ...

4

Magnetic and valence transitions in CePd_2_-_xMn_xSi_2:L_I_I_I edge study  

International Nuclear Information System (INIS)

We report on solid solution CePd_2_-_xMn_xSi_2 which shows an interesting transition of the Ce-ion from magnetism in a Kondo regime to an intermediate valence state coupled with a strongly magnetic 3d sublattice. ((orig.)).

5

Magnetic and valence transitions in CePd[sub 2-x]Mn[sub x]Si[sub 2]:L[sub III] edge study  

Energy Technology Data Exchange (ETDEWEB)

We report on solid solution CePd[sub 2-x]Mn[sub x]Si[sub 2] which shows an interesting transition of the Ce-ion from magnetism in a Kondo regime to an intermediate valence state coupled with a strongly magnetic 3d sublattice. ((orig.))

1994-04-01

6

Valence mixing in rare earth compounds  

International Nuclear Information System (INIS)

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

7

Concentrated Kondo systems in solid solutions on the base of europium ternary compounds  

Energy Technology Data Exchange (ETDEWEB)

The experimental results of the components substitution effect on crystal structure, electronic transport properties, and Eu effective valence in solid solutions based on EuCu{sub 2}Si{sub 2} and EuPd{sub 2}Si{sub 2} ternary compounds are presented. It is shown, that when the Eu effective valence reaches the critical value {nu}{sup cr}{sub eff}=2.1, corresponding to degeneration of the 4f{sup 7} and 4f{sup 6} configurations, the condition of the concentrated Kondo system and an essential perturbation of the band electron spectrum near the Fermi level occur. (orig.).

1990-10-01

8

Concentrated Kondo systems in solid solutions on the base of europium ternary compounds  

International Nuclear Information System (INIS)

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

9

Systematic view of optical absorption spectra in the actinide series  

International Nuclear Information System (INIS)

In recent years sufficient new spectra of actinides in their numerous valence states have been measured to encourage a broader scale analysis effort than was attempted in the past. Theoretical modelling in terms of effective operators has also undergone development. Well established electronic structure parameters for the trivalent actinides are being used as a basis for estimating parameters in other valence states and relationships to atomic spectra are being extended. Recent contributions to our understanding of the spectra of 4+ actinides have been particularly revealing and supportive of a developing general effort to progress beyond a preoccupation with modelling structure to consideration of the much broader area of structure-bonding relationships. We summarize here both the developments in modelling electronic structure and the interpretation of apparent trends in bonding. 60 refs., 9 figs., 1 ...

1985-09-01

10

Systematic view of optical absorption spectra in the actinide series  

Energy Technology Data Exchange (ETDEWEB)

In recent years sufficient new spectra of actinides in their numerous valence states have been measured to encourage a broader scale analysis effort than was attempted in the past. Theoretical modelling in terms of effective operators has also undergone development. Well established electronic structure parameters for the trivalent actinides are being used as a basis for estimating parameters in other valence states and relationships to atomic spectra are being extended. Recent contributions to our understanding of the spectra of 4+ actinides have been particularly revealing and supportive of a developing general effort to progress beyond a preoccupation with modelling structure to consideration of the much broader area of structure-bonding relationships. We summarize here both the developments in modelling electronic structure and the interpretation of apparent trends in bonding. 60 refs., 9 figs., 1 ...

1985-01-01

11

Saturated bonds and anomalous electronic transport in transition-metal aluminides  

Energy Technology Data Exchange (ETDEWEB)

This thesis deals with the special electronic properties of the transition-metal aluminides. Following quasicrystals and their approximants it is shown that even materials with small elementary cells exhibit the same surprising effects. So among the transition-metal aluminides also semi-metallic and semiconducting compounds exist, although if they consist of classic-metallic components like Fe, Al, or Cr. These properties are furthermore coupled with a deep pseusogap respectively gap in the density of states and strongly covalent bonds. Bonds are described in this thesis by two eseential properties. First by the bond charge and second by the energetic effect of the bond. It results that in the caes of semiconducting transition-metal aluminides both a saturation of certain bonds and a bond-antibond alteration in the Fermi level is present. By the analysis of the ...

2006-05-22

12

Inelastic x-ray scattering of dense solid oxygen: Evidence for intermolecular bonding  

UK PubMed Central (United Kingdom)

The detailing of the intermolecular interactions in dense solid oxygen is essential for an understanding of the rich polymorphism and remarkable properties of this element at high pressure. Synchrotron...Full Text Available

2008-08-19

13

Moessbauer study of mixed valent silicides Eu(Ir_1-_xPd_x)_2Si_2  

International Nuclear Information System (INIS)

The solid solutions Eu(Ir_1_-_xPd_x)_2Si_2, which exist for 0#<=#x#<=#0.125 and 0.75#<=#x#<=#1, cristallize with the tetragonal ThCr_2Si_2-type structure. The variation of the europium valence with composition has been thoroughly studied at temperatures 4.2#<=#T#<=#293 K by "1"5"1Eu Moessbauer resonance. For 0#<=#x#<=#0.125 the europium valence at room temperature decreases as x increases. For 0.75#<=#x#<=#1 the valence transition temperature Eu"3"+#->#Eu"2"+ increases as x increases. (orig.).

14

Electronic and spectral properties of adatoms on metals in electrostatic fields  

Energy Technology Data Exchange (ETDEWEB)

Electrostatic fields of the order of 1 V/Angst, as they occur at field emission tips, are comparable to those experienced by valence electrons in atoms and molecules. Such fields are strong enough to induce a significant redistribution of the valence charge in chemical bonds. In this work we investigate the effects on the electronic properties of a single adatom on a metal surface induced by the presence of an electrostatic field. In particular we present the results of a full ab initio DFT calculation, within the embedding method, of the CCV Auger spectra of Si and Mg atoms in and on a jellium-Ag host. Differently from impurities in bulk, Auger spectral profiles of adsorbates on metal surfaces can show notable modifications due to the applied electric field.

2002-11-15

15

Radial distribution functions of amorphous silicon  

Energy Technology Data Exchange (ETDEWEB)

Substantial changes in the radial distribution function of amorphous Si films have been observed in neutron-diffraction studies. The spectra indicate changes in short-range order associated with an approx.11% modification in the bond-angle distribution width. The results allow the first direct comparison of structural and vibrational Raman probes of variations in local order in thin-film amorphous solids. Good agreement is obtained between the measured bond-angle variation and that based on Raman estimates.

1989-03-15

16

Sealant Research for solid oxide fuel cells  

International Nuclear Information System (INIS)

The objective of this work is to develop sealing materials for solid oxide fuel cells (SOFCs). A suitable sealant must form strong, dense bonds with SOFC components, be chemically and mechanically compatible with the components, be stable at 1000 degrees C in the operating environment of the SOFC (H_2 and H_2O on the anode side, O_2 on the cathode side), and must be nonconductive.

1992-07-01

17

Heavy fermion behavior in Ce(Ni_xPd_1_-_x)_2Si_2  

International Nuclear Information System (INIS)

Measurements of the magnetic susceptibility #chi#, specific heat C, and thermoelectric power S were carried out for the solid solution Ce(Ni_xPd_1_-_x)_2Si_2 (0#<=#x#<=#1). With increasing x, the ground state changes from an antiferromagnetic Kondo state (x<0.2) to an intermediate valence state (x>0.3). The heavy fermion state was found to evolve at the crossover concentration at x=0.2, where the long-range magnetic order seems to disappear. [copyright] 2001 American Institute of Physics.

2001-06-01

18

Electronic structure and proton spin-lattice relaxation in PdH  

International Nuclear Information System (INIS)

We report a detailed augmented-plane-wave energy-band study and wave-function analysis of stoichiometric PdH which shows that, even though the Fermi surface of PdH is qualitatively similar to that of silver, the simple ''proton model'' is not valid. Instead, the screening of the proton in PdH is found to be larger than in an isolated H atom due, in part, to the formation of a H-Pd bonding band below the bottom of the d-band complex. This result, which is in qualitative agreement with Switendick's earlier calculation, is confirmed by ultraviolet photoemission experiments. A partial density-of-states (DOS) analysis in the energy range spanned by the six valence and conduction bands reveals the quantitative details of the bonding mechanism between the Pd and H constituents. At the Fermi energy, the high Pd d to H s DOS ratio approx. 10.3 is found to be far higher than expected in silver, despite the fact that the Fermi-surface ...

19

Recycling of AZ31 Mg alloy with high purity Mg deposition layer by hot working (solid recycling)  

Energy Technology Data Exchange (ETDEWEB)

Solid recycling of AZ31 Mg alloy with vapor deposition coating layer of high purity Mg was evaluated. In the open die forging experiments, two AZ31 Mg alloy specimens with the pure Mg layer were sufficiently bonded by forging at 673 K. Furthermore, the Al and Zn of the AZ31 substrate diffused up to the center of the pure Mg layer. By the theoretical analysis, it is suggested that the grain boundary diffusion enhanced by grain refinement due to hot forging contributes to the solid state bonding of the specimens. Also, the solid recycled specimen was fabricated from the AZ31 Mg substrate with pure Mg layer by hot extrusion at 673 K. The solid recycled specimen showed almost the same tensile properties as the virgin extruded specimen. This is probably related not only to the grain boundary diffusion but also severe plastic deformation by hot extrusion. (orig.)

2003-07-01

20

Enhanced diffusion from interstitial trapping during solid-phase-epitaxial growth of silicon alloys. Draft  

Energy Technology Data Exchange (ETDEWEB)

During the recrystallization by solid-phase-epitaxial (SPE) growth of supersaturated silicon alloys, a high concentration of interstitials is trapped. These are released by subsequent heating causing a transient (greatly enhanced) diffusion of the substitutional dopant by an interstitialcy mechanism. The enhancement may be as much as five orders of magnitude over tracer values, and shows an activation energy of only 1.8 +- 0.2 eV. Following the transient, the interstitials condense into loops, allowing an independent estimate to be made of their concentration. From these observations, we propose that during ion implantation, a fraction of the implanted dopants can acquire their natural valency, and retain it as the crystallization interface passes. For group V dopants this creates the trapped interstitials, giving transient enhanced diffusion when they are released by subsequent annealing.

1984-08-01

21

Enhanced diffusion from interstitial trapping during solid-phase-epitaxial growth of silicon alloys  

Energy Technology Data Exchange (ETDEWEB)

During the recrystallization by solid-phase-expitaxial (SPE) growth of supersaturated silicon alloys, a high concentration of interstitials is trapped. These are released by subsequent heating causing a transient (greatly enhanced) diffusion of the substitutional dopant by an interstitialcy mechanism. The enhancement may be as much as five orders of magnitude over tracer values, and shows an activation energy of only 1.8 +/- 0.2 eV. Following the transient, the interstitials condense into loops, allowing an independent estimate to be made of their concentration. From these observations, it is proposed that during ion implantation, a fraction of the implanted dopants can acquire their natural valency, and retain it as the crystallization interface passes. For group V dopants this creates the trapped interstitials, giving transient enhanced diffusion when they are released by subsequent annealing. 12 references, 6 figures.

1984-01-01

22

An empirical model for dielectric constant and electronic polarizability of binary (A{sup N}B{sup 8-N}) and ternary (A{sup N}B{sup 2+N}C{sub 2}{sup 7-N}) tetrahedral semiconductors  

Energy Technology Data Exchange (ETDEWEB)

An overview of the understanding of correlation between valence electron and the optical properties of binary (A{sup N}B{sup 8-N}) and ternary (A{sup N}B{sup 2+N}C{sub 2}{sup 7-N}) tetrahedral semiconductors is presented here. We have presented two expressions relating the dielectric constant and electronic polarizability for the transition metal chalcogenides and pnictides (A{sup II}B{sup VI} and A{sup III}B{sup V}) and chalcopyrites (A{sup I}B{sup III}C{sub 2}{sup VI} and A{sup II}B{sup IV}C{sub 2}{sup V}) with the product of valence electrons and nearest neighbour distance d (A). The dielectric constant and electronic polarizability of these solids exhibit a linear relationship when plotted on a log-log scale against the nearest neighbour distance d (A), but fall on different straight lines according to the valence electron product of the compounds. We have applied the proposed relation on these ...

2009-11-03

23

A simple model for explosives formulation  

Energy Technology Data Exchange (ETDEWEB)

A simple model based on surface chemistry is developed, based an simple concepts of contact angle, wetting and spreading. Results of the modeling can be stated by two simplified rules of thumb'': (1) A liquid will spread on the surface of a solid if the surface tension of the liquid is lose than the surface free energy of the solid, and (2) The liquid having the surface tension nearest that of the solid will preferentially wet the surface of the solid. These two rules can then be used to define the parameters that constitute a process for formulating a plastic bonded explosive (PBX), which is a crystalline high-explosive material coated with a small amount of plastic polymeric material (the binder). The PBX then can be pressed to a high density, and machined to a specific shape. The pressed and machined explosive material can then be used in a physics experiment to ...

1993-01-01

24

A simple model for explosives formulation  

Energy Technology Data Exchange (ETDEWEB)

A simple model based on surface chemistry is developed, based an simple concepts of contact angle, wetting and spreading. Results of the modeling can be stated by two simplified ``rules of thumb``: (1) A liquid will spread on the surface of a solid if the surface tension of the liquid is lose than the surface free energy of the solid, and (2) The liquid having the surface tension nearest that of the solid will preferentially wet the surface of the solid. These two rules can then be used to define the parameters that constitute a process for formulating a plastic bonded explosive (PBX), which is a crystalline high-explosive material coated with a small amount of plastic polymeric material (the binder). The PBX then can be pressed to a high density, and machined to a specific shape. The pressed and machined explosive material can then be used in a physics experiment to study ...

1993-04-01

25

Glass-ceramic sealants for solid oxide fuel cells: Part I. Physical properties  

International Nuclear Information System (INIS)

A family of sealant materials has been developed for use in the solid oxide fuel cell (SOFC) and in other applications in the temperature range of 800 endash 1000 degree C. These materials are based on glasses and glass-ceramics in the SrO endash La_2O_3 endash Al_2O_3 endash B_2O_3 endash SiO_2 system. The coefficients of thermal expansion (CTE) for these materials are in the range of 8 endash 13x10"-"6/degree C, a good match with those of the SOFC components. These sealant materials bond well with the ceramics of the SOFC and, more importantly, form bonds that can be thermally cycled without failure. At the fuel cell operating temperature, the sealants have viscosities in the range of 10"4-10"6 Pa-s, which allow them to tolerate a CTE mismatch of about 20% among the bonded substrates. The gas tightness of a sample seal was demonstrated in a simple zirconia-based oxygen concentration cell. copyright ...

26

Synthesis of novel high-voltage cathode material LiCoPO{sub 4} via rheological phase method  

Energy Technology Data Exchange (ETDEWEB)

For the first time, rheological phase method, a simple and effective route, is applied to synthesize novel cathode material LiCoPO{sub 4}. X-ray diffraction spectrometer (XRD), X-ray photoelectron spectrometer (XPS), transmission electron microscope (TEM) and electrochemical impedance spectroscopy (EIS) are taken to investigate this material, respectively. XRD figure shows that the rheological sample is better crystallized than the solid-state one. XPS result of the rheological sample exhibits that the valence of Co is 2+. TEM images show that better dispersed particles with smaller size can be formed by rheological method comparing to the solid-state route. Charge-discharge test is carried out in the range of 3.0-5.0 V at 0.2 mA cm{sup -2}. The initial discharge capacity for rheological phase and solid-state powder is 71.5 and 30.9 mAh g{sup -1}, respectively. The better electrochemical property should ...

2010-07-23

27

Synthesis of novel high-voltage cathode material LiCoPO4 via rheological phase method  

International Nuclear Information System (INIS)

For the first time, rheological phase method, a simple and effective route, is applied to synthesize novel cathode material LiCoPO4. X-ray diffraction spectrometer (XRD), X-ray photoelectron spectrometer (XPS), transmission electron microscope (TEM) and electrochemical impedance spectroscopy (EIS) are taken to investigate this material, respectively. XRD figure shows that the rheological sample is better crystallized than the solid-state one. XPS result of the rheological sample exhibits that the valence of Co is 2+. TEM images show that better dispersed particles with smaller size can be formed by rheological method comparing to the solid-state route. Charge-discharge test is carried out in the range of 3.0-5.0 V at 0.2 mA cm-2. The initial discharge capacity for rheological phase and solid-state powder is 71.5 and 30.9 mAh g-1, respectively. The better electrochemical property should be ascribed to ...

2010-07-23

28

Valence electronic structure of Ti, Cr, Fe and Co in some alloys from K{beta}-to-K{alpha} X-ray intensity ratio studies  

Energy Technology Data Exchange (ETDEWEB)

K{beta}-to-K{alpha} X-ray intensity ratios of Ti, Cr, Fe and Co in pure metals and in Cr{sub 0.26}Fe{sub 0.74}, Cr{sub 0.80}Co{sub 0.20} and Ti{sub 0.80}Cr{sub 0.20} alloys have been measured following excitation by 59.54 keV {gamma}-rays from a 7400 MBq (200 mCi) {sup 241}Am point-source. The valence electronic structure of Ti, Cr, Fe and Co in the samples have been evaluated by the comparison of the measured K{beta}-to-K{alpha} intensity ratios with the results of multiconfiguration Dirac-Fock calculations performed for various electronic configurations of these metals. The 3d-electron populations obtained for pure metallic Ti, Cr, Fe and Co agree well with the results of band structure calculations of Papaconstantopoulos (Handbook of band structure of elemental solids, Plenum Press, New York, 1986). Our analysis indicates significant increase of 3d-electron population of Ti, Cr and Fe in the alloys with respect to the pure metals, except for ...

2002-10-01

29

Valence electronic structure of Ti, Cr, Fe and Co in some alloys from K#beta#-to-K#alpha# X-ray intensity ratio studies  

International Nuclear Information System (INIS)

K#beta#-to-K#alpha# X-ray intensity ratios of Ti, Cr, Fe and Co in pure metals and in Cr_0_._2_6Fe_0_._7_4, Cr_0_._8_0Co_0_._2_0 and Ti_0_._8_0Cr_0_._2_0 alloys have been measured following excitation by 59.54 keV #gamma#-rays from a 7400 MBq (200 mCi) "2"4"1Am point-source. The valence electronic structure of Ti, Cr, Fe and Co in the samples have been evaluated by the comparison of the measured K#beta#-to-K#alpha# intensity ratios with the results of multiconfiguration Dirac-Fock calculations performed for various electronic configurations of these metals. The 3d-electron populations obtained for pure metallic Ti, Cr, Fe and Co agree well with the results of band structure calculations of Papaconstantopoulos (Handbook of band structure of elemental solids, Plenum Press, New York, 1986). Our analysis indicates significant increase of 3d-electron population of Ti, Cr and Fe in the alloys with respect to the pure metals, except for Cr in ...

2002-10-01

30

Study on the crystallization behaviour and thermal stability of glass-ceramics used as solid oxide fuel cell-sealing materials  

British Library Electronic Table of Contents (United Kingdom)

Glass ceramics are commonly used as sealing materials for planar solid oxide fuel cells (SOFCs). The major requirements of stack and module builders for these materials are the stability of the coefficient of thermal expansion (CTE), excellent bonding (sticking) behaviour and the absence of volatile ingredients, which can lead to changes of the material properties and the sealing ability. SCHOTT Electronic Packaging has developed special glasses and glass-ceramics for various solid oxide fuel cell designs and operating temperatures. The glass compositions are based on the system MgO-Al2O3-BaO-SiO2-B2O3. In this study the evaluation of the developed materials was done by high temperature aging tests for up to 1000h, high temperature XRD-studies and Rietveld calculations, combined with scann...

2011-01-01

31

Electrochemistry of a semiconductor chalcopyrite concentrate leaching by Thiobacillus ferrooxidans  

Energy Technology Data Exchange (ETDEWEB)

Using carbon-paste-CuFeS{sub 2} electrodes and a cyclic voltammetric technique, it was found that a large number of intermediate electrochemical oxidation reactions were associated with the dissolution of chalcopyrite in presence and absence of bacteria. The effects of concentrations of copper, ferrous and ferric ions, as well as of agitation on the peaks of cyclic voltammograms were measured. It was established that chalcopyrite oxidation was solid-state controlled as suggested by the data of chronopotentiometric and chronoamperometric measurements. The activation energy of solid state diffusion of chalcopyrite leaching was determined by the Sand's method to be {triangle}E{sub a} = 20.5 kJ. The leaching mechanism is discussed in terms of solid-state properties (energy bonding) of the n-type semiconductor chalcopyrite and energy density states of redox systems of acidic bacterial leach media. A ...

1991-01-01

32

Field-induced valence transition of Eu(Pd_1_-_xPt_x)_2Si_2  

International Nuclear Information System (INIS)

The magnetic susceptibility and high-field magnetization have been measured for the intermediate valence system Eu(Pd_1_-_xPt_x)_2Si_2 with 0#<=#x#<=#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 1997 The American Physical ...

33

Impact of Hight Velocity Cold Spray Particles  

Energy Technology Data Exchange (ETDEWEB)

This paper presents experimental data and an computational model of the cold spray solid particle impact process. Copper particles impacting onto a polished stainless steel substrate are examined. The high velocity impact causes significant plastic deformation of both the particle and the sub- strate, but no melting is observed. The plastic deformation exposes clean surfaces that, under the high impact pressures, result in significant bond strengths between the particle and substrate. Experimental measurements of the splat and crater sizes compare well with the numerical calculations. It is shown that the crater depth is significant and increases with impact velocity. However, the splat diameter is much less sensitive to the impact velocity. It is also shown that the geometric lengths of the splat and crater scale linearly with the diameter of the impacting particle. It is hoped that the results presented will allow better understanding of the ...

1998-12-01

34

Quantum frustration in organic Mott insulators: from spin liquids to unconventional superconductors  

CERN Document Server

We review the interplay of frustration and strong electronic correlations in quasi-two-dimensional organic charge transfer salts, such as k-(BEDT-TTF)_2X and Et_nMe_{4-n}Pn[Pd(dmit)2]2. These two forces drive a range of exotic phases including spin liquids, valence bond crystals, pseudogapped metals, and unconventional superconductivity. Of particular interest is that in several materials there is a direct transition as a function of pressure from a spin liquid Mott insulating state to a superconducting state. Experiments on these materials raise a number of profound questions about the quantum behaviour of frustrated systems, particularly the intimate connection between spin liquids and superconductivity. Insights into these questions have come from a wide range of theoretical techniques including first principles electronic structure, quantum many-body theory and quantum field theory. In this review we introduce the basic ideas of the field ...

2010-01-01

35

High temperature susceptibilities of actinide monopnictides and monochalcogenides  

International Nuclear Information System (INIS)

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

1998-06-12

36

Full Spin and Spatial Symmetry Adapted Technique for Correlated Electronic Hamiltonians: Application to an Icosahedral Cluster  

CERN Document Server

While dealing with molecular systems, it is highly advantageous to work with a basis set which has definite total spin and also belongs to a definite irreducible representation of its symmetry (point) group. But unfortunately, there hadn't been any general simple technique to deal with the problem, especially when molecule possesses non-Abelian point group symmetry. In a previous paper \\cite{sahoo}, we presented a general technique which is a hybrid method based on Valence Bond basis and the basis of z-component of the total spin. The technique is applicable to all types of point groups and is easy to implement on computer. We illustrated the power of the method by applying it to a molecular magnetic system. Here we extend the method to electronic systems and demonstrate this extended technique by applying it to a model icosahedral half-filled electronic system (12 sites). Reasons we took this model are, its a system with huge Hilbert space ...

2010-01-01

37

A dinuclear Ni(I) system having a diradical Ni2N2 diamond core resting state: synthetic, structural, spectroscopic elucidation, and reductive bond splitting reactions.  

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 ...

2008-10-15

38

Quasi-elastic electron scattering by GaAs surface  

International Nuclear Information System (INIS)

Using the slow electrons spectrometer one can get information on the surface structure, its element composition, chemical bonds, adsorption phenomena, electron state density and surface oscillation. We have developed the methods and created the apparatus that makes it possible to investigate the electron backscattering by solid surface. We have studied the electron scattering by the polycrystalline and monocrystalline. GaAs surface in the energy range of 0 to 9 eV. The FWHM of electron energy distribution function was 70 meV. (author).

1994-03-20

39

Structure and electronic studies of defects in amorphous silicon. Final report, March 1980-February 1981  

Science.gov (United States)

Basic research of the structure and electronic properties of a-Si:H is reported with particular emphasis on the role of defects. The main findings are as follows: (1) low defect density material can be deposited at a high rate using SiH/sub 4/ diluted in He or Ne. Using Ar or Kr results in a high defect density and columnar material; (2) an electrical bias during deposition modifies the band gap, hydrogen concentration and structure; (3) the clustering of hydrogen in the regions between the columns is confirmed; (4) hydrogen diffusion is observed by NMR; (5) the oxidation of an a-Si:H surface results in approx. 3 x 10/sup 11/ cm/sup -2/ dangling bonds at the interface; (6) auger recombination of photoexcited carriers is a significant non-radiative mechanism at low temperatures; (7) non-radiative recombination by diffusion and capture at dangling bonds is observed at temperatures above 50 to 100/sup 0/K; (8) the defect density in doped and ...

1981-08-01

40

Semiconductor-metal transition of pyrite FeS_2 under high pressure by full-potential linearized-augmented plane wave calculations  

International Nuclear Information System (INIS)

The effects of hydrostatic pressure on the electronic band structure of the semiconductor mineral iron pyrite FeS_2 have been investigated theoretically by an ab initio full-potential linearized-augmented plane wave (FPLAPW) method within a local approximation (LDA/GGA) to the density functional theory. The calculations predict that at a pressure of 94.1 GPa the indirect band gap of pyrite FeS_2 vanishes and the material becomes a metal. This is due to the presence of the S-S and Fe-S bonds, which provide novel energy band distortions in the process of attaining the metallic state. Analysis indicates that, under increasing high pressure, the conduction bands (3p_z of sulfur and 3d_x_"2_-_y_"2+3d_x_y of iron) intrude downwards into the valence bands, which are predominantly 3d in nature. At normal pressure, the lattice constant, the bulk modulus, sulfur position parameter u, S-S bond length, and the indirect band gap of ...

2006-10-11

41

Local-density-functional approach to the isostructural #gamma#-#alpha# transition in cerium using the self-consistent linearized-augmented-plane-wave method  

International Nuclear Information System (INIS)

The isostructural #gamma#-#alpha# phase transition of Ce which occurs at 8 kbar has been studied by means of fully self-consistent (non-muffin-tin potential) linearized-augmented-plane-wave energy band calculations carried out for five different values of the lattice constant. In contradiction to the 4f electron promotional model of the transition, the results yield essentially one 4f electron to be occupied in each phase but with the 4f wave function somewhat less localized, and therefore more bandlike, in the ''collapsed'' #alpha# phase. A singly occupied 4f state is shown to be consistent with the available experimental data. These results strongly support the picture of a 4f localized bold-arrow-left-right itinerant transition at the #gamma#-#alpha# transition and conflict with the promotional model in which some fraction of 4f electrons are transferred to the sd conduction bands. The weaker bonding of the 4f electrons, compared to that of the 6s-5d ...

42

Effects of sputtering pressure on the characteristics of lithium ion conductive lithium phosphorous oxynitride thin film  

British Library Electronic Table of Contents (United Kingdom)

Lithium phosphorous oxynitride(Lipon) thin films as a lithium ion conductive electrolyte were prepared by radio frequency reactive sputtering in N2 plasma. The properties of the amorphous Lipon solid electrolyte were investigated as a function of N2 pressure during reactive sputtering. The ionic conductivity and the electrochemical stability of Lipon thin films improved drastically as the N2 pressure decreased. The ionic conductivity closed to 10?6 S cm?1 and obtained a stability window of 1.0?5.0 V with an N2 pressure of 5 mTorr, where the number of nitrogen bonds between the phosphate groups were more than those formed at higher pressure. It was possible to fabricate the Li//LiCoO2 complete thin film battery using this Lipon solid electrolyte, which exhibited excellent discharge characte...

2006-01-01

43

Valence transition and magnetic ordering in Sn doped EuPd/sub 2/Si/sub 2/  

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.

1983-12-01

46

Comparison of the projector augmented-wave, pseudopotential, and linearized augmented-plane-wave formalisms for density-functional calculations of solids  

International Nuclear Information System (INIS)

The projector augmented-wave (PAW) method was developed by Bloechl as a method to accurately and efficiently calculate the electronic structure of materials within the framework of density-functional theory. It contains the numerical advantages of pseudopotential calculations while retaining the physics of all-electron calculations, including the correct nodal behavior of the valence-electron wave functions and the ability to include upper core states in addition to valence states in the self-consistent iterations. It uses many of the same ideas developed by Vanderbilt in his open-quotes soft pseudopotentialclose quotes formalism and in earlier work by Bloechl in his open-quotes generalized separable potentials,close quotes and has been successfully demonstrated for several interesting materials. We have developed a version of the PAW formalism for general use in structural and dynamical studies of materials. In the present paper, we ...

47

Ab initio calculations of the electronic structure of the silver palladium oxide Ag_2PdO_2  

International Nuclear Information System (INIS)

Ab initio calculations of the electronic structure were performed for the silver palladium oxide, Ag_2PdO_2, by the full potential mixed linearized augmented plane wave and augmented plane wave plus local orbitals method (mixed LAPW/APW+lo) within the density functional theory and using the generalized gradient approximation (GGA96, Phys. Rev. Lett. 77 (1996) 3865) for the exchange-correlation potential. The lattice parameters were calculated from the ground-state total energy versus volume curve, and are in good agreement with the available experimental results. Our calculations of band structure predicted that the compound Ag_2PdO_2 has indirect band gap, and the Pd 4d states strongly hybridize with the O 2p states all over the valence bands and conduction bands. The valence bands are composed mainly of Ag, Pd 4d states and O 2p states, while the conduction bands consist mainly of the Pd 4d states and O 2p states. In addition, focusing on the ...

2003-09-01

48

Photocatalytic activities of AgSbO3 under visible light irradiation  

British Library Electronic Table of Contents (United Kingdom)

A novel visible light sensitive photocatalyst, AgSbO3 was prepared by a conventional solid-state reaction method. This oxide belonging to a cubic-pyrochlore structure can absorb visible light with wavelength up to about 480nm. From the band structure calculation, we found that the top of the valence band consists of the hybridized Ag 4d and O 2p orbitals and the bottom of the conduction band mainly consists of the Ag 5s and the Sb 5s orbitals. Photocatalytic activities were evaluated using O2 evolution from an aqueous silver nitrate solution and decomposition of gaseous 2-propanol under visible light irradiation. We found that AgSbO3 shows a higher O2 evolution activity than WO3 and 2-propanol can be mineralized by the AgSbO3 photocatalysis under visible light irradiation.

2008-01-01

49

Linear augmented-plane-wave calculation of the structural properties of bulk Cr, Mo, and W  

International Nuclear Information System (INIS)

A scalar-relativistic procedure for calculating the valence-electron contribution to the total energy of bulk and thin-film solids has been developed and applied to the fcc and bcc phases of the group-VIB transition elements Cr, Mo, and W. This approach, which is based on the linear augmented-plane-wave method and local-density-functional theory, contains no shape approximations for either the charge density or potential. The formulation adopts a rigid-core approximation and incorporates an exact treatment of the core-charge tails that extend beyond the muffin-tin spheres. The application of this procedure to bcc Cr, Mo, and W yields calculated lattice parameters and bulk moduli that are in good (Cr) to excellent (Mo and W) agreement with experiment. The present calculated properties also agree quite well with the results of previous calculations involving a variety of band-structure methods. The calculated fcc-bcc energy difference for Cr, Mo, ...

50

Field-induced valence transition of Eu(Pd{sub 1{minus}x}Pt{sub x}){sub 2}Si{sub 2}  

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 ...

1997-05-01

51

Palladium(II) and platinum(II) saccharinate complexes containing pyridine and 3-acetylpyridine: Synthesis, crystal structures, fluorescence and thermal properties  

British Library Electronic Table of Contents (United Kingdom)

New palladium(II) and platinum(II) complexes of saccharinate (sac), trans-[Pd(py)"2(sac)"2] (1), cis-[Pt(py)"2(sac)"2] (2), trans-[Pd(3-acpy)"2(sac)"2] (3) and cis-[Pt(3-acpy)"2(sac)"2] (4) (py=pyridine and 3-acpy=3-acetylpyridine) have been synthesized. Elemental analysis, UV-Vis, IR, NMR and TG/DTA characterizations have been carried out. The structures of 1-4 were determined by X-ray diffraction. The palladium(II) and platinum(II) ions are coordinated by two N-bonded sac ligands, and two nitrogen atoms of py or 3-acpy, forming a distorted square-planar geometry. The palladium(II) complexes (1 and 3) are trans isomers, while the platinum(II) complexes (2 and 4) are cis isomers. The mononuclear species in the solid state are connected by weak intermolecular C-H...O hydrogen bonds, C-H...@...

2011-01-01

52

Overview of advanced techniques for fabrication and testing of ITER multilayer plasma facing walls  

International Nuclear Information System (INIS)

The design of the ITER primary first wall incorporates a multi-layered structure consisting of a layer of beryllium bonded to a layer of copper alloy with embedded stainless steel tubes which in turn is bonded to a stainless steel structure. In this configuration, the stainless steel provides structural support, the copper alloy improved resistance to high heat loads, and the beryllium layer a low Z metal interface with plasma. Fabrication, testing and control of this multi-layered structure, and indeed the entire blanket shield module, calls for advanced methods. Several associations in the four home teams and their industrial partners have been involved in various fabrication and joining tasks now grouped under L4 blanket project. In this paper, an overview of the work done so far for joining stainless steel to stainless steel, stainless steel to copper alloy, copper alloy to copper alloy, and copper alloy to beryllium is presented. ...

1998-09-01

53

Multiple-Bond Kinetics from Single-Molecule Pulling Experiments: Evidence for Multiple NCAM Bonds  

UK PubMed Central (United Kingdom)

The kinetic parameters of single bonds between neural cell adhesion molecules were determined from atomic force microscope measurements of the forced dissociation of the homophilic protein-protein bonds....Full Text Available

2005-11-01

54

Thermal and mechanical properties of poly(vinyl alcohol) plasticized with glycerol  

British Library Electronic Table of Contents (United Kingdom)

Abstract Thermomechanical behavior of membranes based on blends of poly(vinyl alcohol) (PVA) with different weight percentage (wt %) of glycerol has been studied. Solid-state PVA/Glycerol polymer membranes were prepared by a solution casting method. The films were studied for thermal characteristics by differential scanning calorimetry (DSC) and thermogravimetric analysis and for the mechanical properties including hardness and modulus by nanoindentation method. The dispersion of glycerol within the polymer matrix was examined using scanning electron microscopy. Fourier transform infrared spectroscopy was used to confirm the formation of hydrogen bonding between the plasticizer and PVA in their blends and also to provide information on compatibility and physical interactions between the gl...

2011-01-01

55

Porous β-SiAlON Ceramic with Closed Packed Macropore  

British Library Electronic Table of Contents (United Kingdom)

Porous ?-SiAlON ceramics are synthesized by reaction bonded method using hollow alumina spheres (HASs) as both sintering aids and pore-forming agents. Both micropores and macropores, which are constructured by SiAlON grains with different morphologies, are formed in the final SiAlON samples. The micropores are three-dimentional, and are built by equiaxial grains. While the hollow macropores, which have the similar morphology to hollow alumina sphere, are packed by elongated grains. In the sintering process, the solid dissolution process takes place, giving rise to the different alumina concentration of liquid phase, and thus resulting in the formation of two kinds of grains, the equiaxial grain and the elongated grain.

2011-01-01

56

Neutron powder diffraction and solid-state deuterium NMR studies of Ca{sub 2}RuD{sub 6} and the stability of transition metal hexahydride salts  

Energy Technology Data Exchange (ETDEWEB)

The crystal structure of Ca{sub 2}RuD{sub 6} has been determined by neutron powder diffraction: space group Fm3m, K{sub 2}PtCl{sub 6} structure, as found for other hexahydride salts of group 8 metals with alkaline earth or lanthanide counter ions. No structural phase transition was observed between 340 K and 50 K. The deuterium nuclear quadrupole coupling constant, 54.7 kHz, leads to an ionic character of the Ru-D bond of 76%. The known trends in the behaviour of A{sub 2}MH{sub 6} salts are interpreted in terms of the ionization energies of the cation and the central metal atom.

2008-07-28

57

Neutron powder diffraction and solid-state deuterium NMR studies of Ca2RuD6 and the stability of transition metal hexahydride salts  

British Library Electronic Table of Contents (United Kingdom)

The crystal structure of Ca2RuD6 has been determined by neutron powder diffraction: space group Fm3m, K2PtCl6 structure, as found for other hexahydride salts of group 8 metals with alkaline earth or lanthanide counter ions. No structural phase transition was observed between 340K and 50K. The deuterium nuclear quadrupole coupling constant, 54.7kHz, leads to an ionic character of the Ru-D bond of 76%. The known trends in the behaviour of A2MH6 salts are interpreted in terms of the ionization energies of the cation and the central metal atom.

2008-01-01

58

Magnetic pulse welding (MPW); Magnetumformen - Fuegen und Schweissen (MPW)  

Energy Technology Data Exchange (ETDEWEB)

Magnetic pulse welding, a cold solid state bonding process, is becoming a viable replacement for conventional fusion welding processes and explosive welding. The process is presented here along with its fundamental equations and applications of similar and dissimilar welds are illustrated along with typical interface microstructures. (orig.) [German] Magnetimpuls-schweissen, ein Verbindungsverfahren im kalten Festzustand, wird ein funktionsfaehiger Ersatz fuer das herkoemmliche Schmelzschweissverfahren und das Explosionsschweissverfahren. Das Verfahren wird hier mit seinen grundlegenden Gleichungen vorgestellt, und Anwendungen von aehnlichen und unaehnlichen Schweissungen werden mit typischen Schnittstellen-Mikrostrukturen veranschaulicht. (orig.)

2001-07-01

59

Interfacial ultrafine-grained structures on aluminum alloy 6061 joint and copper alloy 110 joint fabricated by magnetic pulse welding  

British Library Electronic Table of Contents (United Kingdom)

Magnetic pulse welding is a solid state impact welding process, similar to explosive welding, which produces metallurgical bond by oblique high-speed impact between two metal bodies. This violent impact removes the metal surface oxide layers and then joins the two atomic level clean metal surfaces together by the incidental compression pressure. The impact velocity is at 200?400?m/s and the being welded metal surface undergoes severe plastic deformation with strain rate in the order of 106?107?s?1. The ultrafine-grained structure was observed on the welded interface. This article studied two types of similar material lap joint interfaces and the base metals were aluminum alloy 6061 and copper alloy 110. Nano-indentation testing shows that the welded interfaces have significantly greater ha...

2010-01-01

60

Vacuum Packaging for Microelectromechanical Systems ...  

Science.gov (United States)

... more than expected in developing a unique bond strength measurement protocol that is important for a wide range of bond strength measurements. ...

2002-10-01

61

X-ray absorption spectroscopy, EELS, and full-potential augmented plane wave study of the electronic structure of Ti_2AlC, Ti_2AlN, Nb_2AlC, and (Ti_0_._5Nb_0_._5)_2AlC  

International Nuclear Information System (INIS)

The structural parameters of various Haegg phases (H or M_n_+_1AX_n phases) are studied experimentally by x-ray and electron spectroscopies, x-ray diffraction, and ab initio full potential as well as full mutiple scattering theoretical calculations. Experimentally it was found that the structure of all ternary compounds analyzed herein are relaxed. The values of the lattice parameters and relaxations obtained from ab initio calculations are in excellent agreement with those deduced from the analysis of the experimental data. The bonding scheme has been analyzed and the charge transfer between constituting atoms determined. It is demonstrated that the strength and electrical transport properties in these materials are principally governed by the metallic planes. For the solid solution (Ti_0_._5Nb_0_._5)_2AlC, the most salient result is that the basal planes are corrugated, which could explain the solid solution scattering ...

2005-01-01

62

Diffusion research between Ni3Al coating and titanium alloy produced by plasma spraying process  

British Library Electronic Table of Contents (United Kingdom)

A Ni3Al coating was prepared by plasma spraying technique on the surface of titanium alloy. Ni-Al mixed powders, coatings and reaction products were investigated by scanning electron microscope, EDS, DSC and XRD. A tight bonding between the coating and the substrate was formed. The X-ray diffraction analysis of the patterns showed that the coating not only had Ni3Al phase, but also had NiO and Al2O3 phase microcontent. Comparing Ni coated Al to Ni3Al at 900^oC, the diffusion was stronger and the diffusion layer was thicker. A minute pore structure was formed at 1200^oC in the front edge of solid-state reaction layer. So Ni3Al restrained the solid-state reaction of the coating with the substrate, and as a whole weakened the entry of oxygen atoms into the substrate and quenched the out-diffu...

2010-01-01

63

Effects of pH and phosphate on metal distribution with emphasis on As speciation and mobilization in soils from a lead smelting site  

Energy Technology Data Exchange (ETDEWEB)

Arsenic in soils from the Asarco lead smelter in East Helena, Montana was characterized by X-ray absorption spectroscopy (XAS). Arsenic oxidation state and geochemical speciation were analyzed as a function of depth (two sampling sites) and surface distribution. These results were compared with intensive desorption/dissolution experiments performed in a pH stat reactor for samples from the site with the highest degree of As heterogeneity. The objectives of the study were to investigate the solid-phase geochemical As speciation, assess the speciation of As in solutions equilibrated with the solids under controlled pH (pH=4 or 6) and Eh (using hydrogen or air) environments, observe the effects of phosphate on the release of As into solution, and examine the effects of phosphate on metal mobility in the systems. Arsenic was predominantly found in the As(V) valence state, though there was evidence that As(III) and As(0) were ...

2005-06-01

64

Oxidation and adsorption of Co(II)EDTA 2- complexes in subsurface materials with iron and manganese oxide grain coatings  

Science.gov (United States)

Batch interaction experiments were performed under aerobic conditions to characterize the adsorption behavior and valence speciation of CoEDTA complexes (equimolar at 10 -5 mol/L) in a series of Pliocene subsurface sediments containing various amounts of Fe and Mn oxides. The experiments were performed in 0.003 mol/L Ca(ClO 4 ) 2 with a solids concentration of 500 g/L at variable pH (4-9) and at the natural pH of the sediments (pH = 8.3). Three of these subaerial sediments (Ringold 1, 2, 3) contained significant quantities of extractable Fe and Mn, while the fourth (Ringold 4) was virtually devoid of sesquioxide precipitates. Microscopic and mineralogic analyses of the most heavily encrusted material (Ringold 2) showed that the oxides existed as intergrain cements and contained crystalline goethite and rancieite/todorokite. Adsorption on a synthetic analog sorbent (0.6 mass % ferrihydrite-coated sand) over a range in pH showed that, while ...

1995-11-01

65

Density functional theory and topological analysis on the hydrogen bonding interactions in cysteine-thymine complexes  

British Library Electronic Table of Contents (United Kingdom)

Abstract Hydrogen bonding interactions between amino acids and nucleic acid bases constitute the most important interactions responsible for the specificity of protein binding. In this study, complexes formed by hydrogen bonding interactions between cysteine and thymine have been studied by density functional theory. The relevant geometries, energies, and IR characteristics of hydrogen bonds (H-bonds) have been systematically investigated. The quantum theory of atoms in molecule and natural bond orbital analysis have also been applied to understand the nature of the hydrogen bonding interactions in complexes. More than 10 kinds of H-bonds including intra- and intermolecular H-bonds have been found in complexes. Most of intermolecular H-bonds involve O (or N) atom as H-acceptor, whereas the...

2011-01-01

66

Heat capacity of VT1-0 commercial titanium and VT5 and VT5-1 titanium base alloys at low temperature  

International Nuclear Information System (INIS)

The temperature dependences of the heat capacity of commercial titanium VT1-0 and alloys on its base, VT5 and VT5-1, have been derived in the temperature range of 4 to 290 K. For comparison, similar measurements have been conducted on pure titanium and specially prepared solid solutions on its base (Ti+3.7 at.% Al and Ti+0.82 at.% Sn). The measurement accuracy has been sufficient for comparing the results with calculation data. The obtained results are interpreted using the known concepts of the role of the mass of interstitial atoms and changes in the interatomic bond forces. It is shown that the phonon components of the molar heat capacities of solid solutions of Al in titanium have lower values in the entire temperature range, as compared to titanium. The corresponding differences are proportional to the Al concentrations. The lower molar heat capacity in the case of dissolution of Al is due to the low mass of the ...

1978-01-01

67

Uranium and thorium based phosphate matrix: synthesis, characterizations and lixiviation; Matrices a base de phosphate d'uranium et de thorium: syntheses, caracterisations et lixiviation  

Energy Technology Data Exchange (ETDEWEB)

In the framework of the search for a ceramic material usable in the radioactive waste storage, uranium and thorium phosphates have been investigated. Their experimental synthesis conditions have been entirely reviewed, they lead to the preparation of four new compounds: U(UO{sub 2})(PO{sub 4}){sub 2}, U{sub 2}O(PO{sub 4}){sub 2}, UCIPO{sub 4}, 4H{sub 2}O, and Th{sub 4}(PO{sub 4}){sub 4}P{sub 2}O{sub 7}. Experimental evidenced are advanced for non existent compounds such as: U{sub 3}(PO{sub 4}){sub 4}, U{sub 2}O{sub 3}P{sub 2}O{sub 7} and Th{sub 3} (PO{sub 4}){sub 4}. Characterization by several techniques (X-rays and neutron powder diffractions, UV-Visible and Infra-red spectroscopies, XPS,...) were performed. The ab initio structure determination of U(UO{sub 2})(PO{sub 4}){sub 2} has been achieved by X-rays and refined by neutron diffractions. Through its physico-chemical analysis, we found that this compound was a new mixed valence uranium phosphate in which ...

1995-03-01

68

Direct observation of intraionic and interconfigurational excitations in an intermediate-valence compound by Raman spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

Intraionic spin-orbit--split multiplet levels have been observed by electronic Raman scattering in the intermediate-valence compound EuPd/sub 2/Si/sub 2/. From the temperature dependence of the Raman peak positions and widths the interconfigurational excitation energy E/sub x/ and an upper limit of the interconfigurational mixing width T/sub f/, respectively, have been obtained. This is the first spectroscopic support for the underlying assumptions of the ionic interconfigurational fluctuation model that has been proposed to describe intermediate valence.

1985-01-21

69

Direct observation of intraionic and interconfigurational excitations in an intermediate-valence compound by Raman spectroscopy  

International Nuclear Information System (INIS)

Intraionic spin-orbit--split multiplet levels have been observed by electronic Raman scattering in the intermediate-valence compound EuPd_2Si_2. From the temperature dependence of the Raman peak positions and widths the interconfigurational excitation energy E/sub x/ and an upper limit of the interconfigurational mixing width T/sub f/, respectively, have been obtained. This is the first spectroscopic support for the underlying assumptions of the ionic interconfigurational fluctuation model that has been proposed to describe intermediate valence.

70

TmPd_2Si_2 and YbPd_2Si_2. Crystal fields and intermediate valence  

International Nuclear Information System (INIS)

... low temperature moessbauer effect palladium silicides thulium silicides thulium

72

Manufacture of PLZT Bonded Lens Assemblies.  

Science.gov (United States)

Two manufacturing processes have been developed for fabricating PLZT bonded lens assemblies (BLA's) for the USAF EEU-2/P Thermal/Flash Protective Goggle. One process utilizes thin Sylgard spacers which remain in the BLA to establish bond thickness between...

1979-01-01

73

Hydrogen bonding and perhalometallate ions: A supramolecular synthetic strategy for new inorganic materials  

UK PubMed Central (United Kingdom)

A synthetic strategy for constructing ionic hydrogen-bonded materials by combining perhalometallate anions with cations able to serve as hydrogen bond donors is presented. The approach is based on identification...Full Text Available

2002-04-16

74

43 CFR 3214.10 - Who must post a geothermal bond?  

Science.gov (United States)

...2010-10-01 false Who must post a geothermal bond? 3214.10 Section 3214...MINERALS MANAGEMENT (3000) GEOTHERMAL RESOURCE LEASING Personal and... § 3214.10 Who must post a geothermal bond? (a) The lessee...

2010-10-01

75

An evaluation of three methods of bonding resin composite to stainless steel.  

Science.gov (United States)

Three bonding agents were evaluated to determine which were most effective in enhancing the bond of resin composite to stainless steel. A light-activated resin composite was bonded to a total of 60 stainless steel specimens using Panavia, Cover-Up, or Silicoating. Tensile bond strength measurements revealed that all three agents provide a satisfactory means of increasing adherence of the esthetic veneer without decreasing bonding through thermocycling of the specimens. Panavia and Cover-Up were significantly more effective than Silicoating and appear to be easier to use. PMID:8297460

76

The diffusion bonding and theoretical model including void growth mechanism in magnesium alloys  

Energy Technology Data Exchange (ETDEWEB)

There are many factors affecting diffusion bonding in order to obtain high quality joining. Therefore, in the beginning, we constructed diffusion bonding model based on void growth mechanism to predict bonding pressures and times. In addition, in order to compare theoretical values with experimental values, diffusion bonding tests were carried out by using commercial AZ31 magnesium alloy sheets with different grain sizes, 16 and 130 {mu}m. The present AZ31 alloys were successfully diffusion bonded at several conditions, and the bonding strength was more than 0.8 of each parent materials. The experimental bonding conditions in high quality joining, times and pressures, were good agreed with prediction analysis. (orig.)

2003-07-01

77

Palladium- and Copper-Catalyzed Arylation of Carbon-Hydrogen Bonds  

UK PubMed Central (United Kingdom)

The transition-metal-catalyzed functionalization of C-H bonds is a powerful method for generating carbon-carbon...Full Text Available

2009-08-18

78

Evaluation of adhesive bonded sandwich panels for ...  

Science.gov (United States)

... content of the environment) are significant factors affecting the useful service life of adhesive bonded plastic composite sandwich panels at 650 F ...

1970-10-01

79

Oxidation and adsorption of Co(II) EDTA{sup 2-} complexes in subsurface materials with iron and manganese oxide grain coatings  

Science.gov (United States)

Batch interaction experiments were performed under aerobic conditions to characterize the adsorption behavior and valence speciation of CoEDTA complexes (equimolar at 10{sup -5} mol/L) in a series of Pliocene subsurface sediments containing various amounts of Fe and Mn oxides. The experiments were performed in 0.003 mol/L Ca(ClO{sub 4}){sub 2} with a solids concentration of 500 g/L at variable pH (4-9) and at the natural pH of the sediments (pH = 8.3). Three of these subaerial sediments (Ringold 1, 2, 3) contained significant quantities of extractable Fe and Mn, while the fourth (Ringold 4) was virtually devoid of sesquioxide precipates. Microscopic and mineralogic analyses of the most heavily encrusted material (Ringold 2) showed that the oxides existed as intergrain cements and contained crystalline goethite and rancieite/todorokite. Adsorption on a synthetic analog sorbent (0.6 mass% ferrihydrite-coated sand) over a range in pH showed that, ...

1995-11-01

80

Spin fluctuation changes in Ge doped YbPd_2Si_2  

International Nuclear Information System (INIS)

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

81

Synchrotron PES and NEXAFS studies of self-assembled aromatic thiol monolayers on Au(1 1 1)  

Energy Technology Data Exchange (ETDEWEB)

Self-assembled monolayers (SAMs) on various metal, semiconductor or insulator substrates can be easily modified with specific functional groups of interest and have promising applications in surface wetting (hydrophobic/hydrophilic modification), tribology, corrosion protection, sensor electrodes modification, molecular and biomolecular recognition, protein adsorption, cell adhesion, and molecular- or organic-electronic device fabrications. In this paper, we highlight recent progress in the development of SAMs on solid substrates as well as their practical applications, with particular emphasis on the characterization of self-assembled aromatic thiol monolayers with different functional groups on Au(1 1 1) using synchrotron-based photoemission spectroscopy and near-edge X-ray absorption fine structure measurements. The SAM-related molecular orientation, electronic structures, and chemical bonding are presented. Using copper(II) phthalocyanine ...

2009-05-15

82

Solid-state amorphization of a quenched high-pressure GaSb phase studied by real-time neutron diffraction: evolution of the crystalline phase  

Energy Technology Data Exchange (ETDEWEB)

The amorphization of a quenched sample of the GaSb-II high-pressure phase was studied at ambient pressure by real-time neutron diffraction in the course of the sample heating from 100 K to room temperature at a rate of 0.4 K min{sup -1}. The transformation to the amorphous state begins at 140 K and is completed near room temperature. The {beta}-Sn type structure was shown to represent only the mean lattice of the high-pressure GaSb-II phase. The superstructure of this phase widely varied with temperature and is caused by the ordered displacement of atoms. The temperature range of the metastable crystalline phase relaxation is divided into three intervals according to the temperature dependence of the tetragonality ratio (c/a). At the boundaries of these temperature intervals, i.e. temperatures T = 170 and 230 K, two second-order phase transitions are observed. Anomalous heat and volumetric effects were observed earlier by means of calorimetry and dilatometry in the same temperature ...

2009-01-28

83

Solid-state amorphization of a quenched high-pressure GaSb phase studied by real-time neutron diffraction: evolution of the crystalline phase  

International Nuclear Information System (INIS)

The amorphization of a quenched sample of the GaSb-II high-pressure phase was studied at ambient pressure by real-time neutron diffraction in the course of the sample heating from 100 K to room temperature at a rate of 0.4 K min-1. The transformation to the amorphous state begins at 140 K and is completed near room temperature. The ?-Sn type structure was shown to represent only the mean lattice of the high-pressure GaSb-II phase. The superstructure of this phase widely varied with temperature and is caused by the ordered displacement of atoms. The temperature range of the metastable crystalline phase relaxation is divided into three intervals according to the temperature dependence of the tetragonality ratio (c/a). At the boundaries of these temperature intervals, i.e. temperatures T = 170 and 230 K, two second-order phase transitions are observed. Anomalous heat and volumetric effects were observed earlier by means of calorimetry and dilatometry in the same temperature range. ...

2009-01-28

84

Point defect engineering in preamorphized silicon enriched with fluorine  

International Nuclear Information System (INIS)

Fluorine is known to have a beneficial role for the B diffusion reduction in preamorphized Si, and is promising for the realization of ultra-shallow junctions. Thus, we studied the F incorporation in Si during the solid phase epitaxy (SPE) process, pointing out the effects of the implanted F energy and fluence and the role played by the possible presence of dopants. The incorporation of fluorine proceeds by F segregation at the amorphous-crystalline interface, with a kinetics driven by the SPE rate. In fact, the quicker the SPE rate, the higher is the F fluence retained. Moreover, we demonstrated that F incorporated in Si layers does not appreciably affect the Is emission from spatially separated end-of-range (EOR) defects. The modification, induced by the presence of F, of the point defect density (Is and Vs) was also studied by means of B and Sb spike layers, used as local markers for Is and Vs, respectively. We showed that F is not only able to completely ...

2006-12-01

85

3. 3-Bis (azidomethyl) oxetane (BAMO)-based propellants. (1). ; Synthesis and characterizatio of BAMO-based polymers. BAMO kei suishin yaku no kenkyu. (1). ; BAMO kei jugotai no gosei to tokusei hyoka  

Energy Technology Data Exchange (ETDEWEB)

Concerning high performance composite solid propellant BAMO and BAMO-based copolymers, synthetic method and properties of them were studied. Comparison graph of theoretical specific impulse for various propellants were shown, by that, reason why highest specific impulse BAMO was selected as direction of the study. As the orientation of synthesis, those were indicated that radicals at both ends should be hydroxyl so as urethane bonding was available, that liquid at normal temperature was required for easy handling, and that glass transition temperature is required to be low enough. Synthesis was conducted by ring-opening polymerization of ring ether detail procedures of which were explained. Measurements of properties was performed for thermochemical properties, thermal decomposition, combution heat, and friction sensitivity test to confirm safety. As the result, those were understood that thermal decomposition was divided into two phases, rapid ...

1990-08-31

86

Valence-electron configuration of Ti and Ni in TixNi1-x alloys from Kbeta-to-Kalpha X-ray intensity ratio studies.  

Science.gov (United States)

Kbeta-to-Kalpha X-ray intensity ratios of Ti and Ni have been measured in pure metals and in alloys of Ti(x)Ni(1-x) (x=0.7, 0.6, 0.5, 0.4 and 0.3) following excitation by 22.69 keV X-rays from a 10 mCi (109)Cd radioactive point source. The valence-electron configurations of these metals were determined by corporation of measured Kbeta-to-Kalpha X-ray intensity ratios with the results of multiconfiguration Dirac-Fock calculation for various valence-electron configurations. Valence-electron configurations of 3d-transition metals in alloys indicate significant differences with respect to the pure metals. Our analysis indicates that these differences arise from delocalization and/or charge transfer phenomena in alloys. Namely, the observed change of the valence-electron configurations of metals in alloys can be explained with the transfer of 3d electrons from one element to the other element and/or the ...

2010-01-28

87

Valence-electron configuration of Ti and Ni in TixNi1-x alloys from K?-to-K? X-ray intensity ratio studies  

International Nuclear Information System (INIS)

K?-to-K? X-ray intensity ratios of Ti and Ni have been measured in pure metals and in alloys of TixNi1-x (x=0.7, 0.6, 0.5, 0.4 and 0.3) following excitation by 22.69 keV X-rays from a 10 mCi 109Cd radioactive point source. The valence-electron configurations of these metals were determined by corporation of measured K?-to-K? X-ray intensity ratios with the results of multiconfiguration Dirac-Fock calculation for various valence-electron configurations. Valence-electron configurations of 3d-transition metals in alloys indicate significant differences with respect to the pure metals. Our analysis indicates that these differences arise from delocalization and/or charge transfer phenomena in alloys. Namely, the observed change of the valence-electron configurations of metals in alloys can be explained with the transfer of 3d electrons from one element to the other element and/or the rearrangement of ...

2010-06-01

88

Coordination of U"4"+ in the complex U(P_2W_1_7O_6_1)"1"6"-_2 in solid state and in aqueous solution  

International Nuclear Information System (INIS)

The aim of this work is to understand the reasons for the selectivity shown in the complexation by unsaturated heteropolyanions (HPA) of actinides (An) which are oxidized to the number +IV. Different studies have been carried out, both in solution and in solid state, on P_2W_1_7O_6_1"1"0"- and its complexes with Zn"2"+, UO_2"2"+, Ce"4"+, Th"4"+ and U"4"+ to characterize the nature of the complexation site offered to the cation. Among the actinides(IV), the U"4"+ ion has been selected due to its singular spectroscopic and magnetic properties. An initial series of studies, in solution, using NMR"3"1P has thus enabled us to characterize these complexes and to compare them to those formed with the complexing agent PW_1_1O_3_9"8"-. This body of data allows to identify an identical complexation site for both ligands. An analysis of the NMR"3"1P spectrum of U(P_2W_1_7O_6_1)_2"1"6"- has shown a plane of symmetry passing through the actinide and enables us to confirm the ...

1996-09-01

90

Radial distribution of bonded fission gas in mixed carbide fuel pins  

International Nuclear Information System (INIS)

The fission gas xenon bonded in bubbles, in pore, and in the lattice of mixed carbide fuels is measured by electron-probe microanalysis. Radial xenon distribution and release curves are determined and are calibrated by gas chromatography of the bonded fission gas and by burnup analysis in the respective pin sections of the irradiation experiments FR2 6A and 6C, Mol 11/K 2, and DFR 330/1. The results are correlated to the microstructure of the fuel, bonding medium, temperature, and burnup. (Auth.).

1979-01-01

94

Joining of boron carbide using nickel interlayer  

International Nuclear Information System (INIS)

Carbide ceramics such as boron carbide due to their unique properties such as low density, high refractoriness, and high strength to weight ratio have many applications in different industries. This study focuses on direct bonding of boron carbide for high temperature applications using nickel interlayer. The process variables such as bonding time, temperature, and pressure have been investigated. The microstructure of the joint area was studied using electron scanning microscope technique. At all the bonding temperatures ranging from 1150 to 1300degC a reaction layer formed across the ceramic/metal interface. The thickness of the reaction layer increased by increasing temperature. The strength of the bonded samples was measured using shear testing method. The highest strength value obtained was about 100 MPa and belonged to the samples bonded at 1250 for 75 min ...

95

Ab initio and AIM studies on typical -type and pseudo--type halogen bonds: Comparison with hydrogen bonds  

British Library Electronic Table of Contents (United Kingdom)

Abstract Series of typical -type and pseudo--type halogen-bonded complexes BClY and BBrY and hydrogen-bonded complex BHY (B = C2H4, C2H2, and C3H6; Y = F, Cl, and Br) have been investigated using the MP2/aug-cc-pVDZ method. A striking parallelism was found in the geometries, vibrational frequencies, binding energies, and topological properties between BXY and BHY (X = Cl and Br). It has been found that the lengths of the weak bond d(X)/d(H), the frequencies of the weak bond (X)/(H), the frequency shifts (XY)/(HY), the electron densities at the bond critical point of the weak bonds c(X)/c(H), and the electron density changes c(XY)/c(HY) could be used as measures of the strengths of typical -type and pseudo--type halogen/hydrogen bonds. The typical -type and pseudo--type halogen bond and hyd...

2011-01-01

96

Diffusion bonding on superplastic-aluminum and -magnesium alloys  

Energy Technology Data Exchange (ETDEWEB)

The superplastic characteristics and diffusion bonding behaviors were investigated in commercial 7475 aluminum alloy and AZ31 magnesium alloy sheets. In this study, the presently used materials behaved in a superplastic manner at {proportional_to} 773 K (7475Al) and {proportional_to} 523 K (AZ31). Then, by the theoretical relationship between pressure and time, these materials were successfully diffusion bonded at the superplastic temperatures. The bonding strength was more than 65 MPa. The experimental bonding conditions in high quality joining, times and pressures, were good agreed with prediction analysis. (orig.)

2004-07-01

97

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

Science.gov (United States)

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

2011-08-01

98

Evidence for valence transitions in neutron capture gamma-ray spectra in /sup 88/Sr  

Energy Technology Data Exchange (ETDEWEB)

Neutron capture ..gamma..-ray spectra have been measured at 11 average neutron energies from 10 to 530 keV in /sup 88/Sr using a 20 x 15 cm NaI detector with time-of-flight discrimination of background events. The partial radiation widths and the calculated partial valence widths are compared for the strong p-wave resonances at 287 and 321 keV and found to be highly correlated. At these energies, the spectra are dominated by strong transitions to low-lying single particle states, in confirmation of the role of valence capture in the 3p region. However, the data do not support this mechanism at <508> keV.

1985-01-15

99

Evidence for valence transitions in neutron capture gamma-ray spectra in /sup 88/Sr  

International Nuclear Information System (INIS)

Neutron capture #gamma#-ray spectra have been measured at 11 average neutron energies from 10 to 530 keV in /sup 88/Sr using a 20 x 15 cm NaI detector with time-of-flight discrimination of background events. The partial radiation widths and the calculated partial valence widths are compared for the strong p-wave resonances at 287 and 321 keV and found to be highly correlated. At these energies, the spectra are dominated by strong transitions to low-lying single particle states, in confirmation of the role of valence capture in the 3p region. However, the data do not support this mechanism at <508> keV.

1984-09-10

100

Cerium moment collapse in ternary silicides CePd_2_-_xMn_xSi_2 (0#<=#x#<=#2)  

International Nuclear Information System (INIS)

Cerium L_3 XANES (x-ray-absorption near-edge-structure) spectra were analyzed to separate Ce moment contributions and mixed valence (MV) in complex magnetic silicides CePd_2_-_xMn_xSi_2 (0#<=#x#<=#2). The Ce valence mixing does not vary linearly with x, but increases rapidly for x#>=#1.5. The associated moment collapse correlates with pronounced deviations of the unit-cell volume from Vegard law and the onset of structural instability. Reorientation of [001] Mn 3d antiferromagnetic order for x<2 appears to rapidly suppress the weak Ce valence mixing coexisting with antiferromagnetic order in CeMn_2Si_2.

102

Study on the structural evolution of modified phenol-formaldehyde resin adhesive for the high-temperature bonding of graphite  

International Nuclear Information System (INIS)

A novel adhesive for carbon materials composed of phenol-formaldehyde resin, boron carbide and fumed silica, was prepared. The adhesive property of graphite joints bonded by the above adhesive treated at high-temperatures was tested. Results showed that the adhesive was found to have outstanding high-temperature bonding properties for graphite. The adhesive structure was dense and uniform even after the graphite joints were heat-treated at 1500 deg. C. Bonding strength was 17.1 MPa. The evolution of adhesive structure was investigated. The results indicated that the addition of the secondary additive, fumed silica, improved the bonding performance greatly. Borosilicate phase with better stability was formed during the heat-treatment process, and the volume shrinkage was restrained effectively, which was responsible for the satisfactory high-temperature bonding performance of ...

2006-01-01

103

Valence-band offsets at the Al{sub x}Ga{sub 0.5{minus}x}In{sub 0.5}P-ZnSe(001) lattice-matched interface  

Energy Technology Data Exchange (ETDEWEB)

The difficulty in making good Ohmic contact at the interfaces with p-doped ZnSe is an important problem hindering the realization of blue-light-emitting diode lasers based on the II-VI semiconductor technology. So far no metal or semiconductor material has been found to have a low enough barrier at the (001) interface with ZnSe. A possible solution to this problem is the insertion of a so-called {ital barrier-reduction layer} at the interface with ZnSe. We have investigated the interface formation energies and valence-band offsets at the (001) interface between Al{sub x}Ga{sub 0.5{minus}x}In{sub 0.5}P and ZnSe. The results of our calculations show the existence of a strong interdependence between the valence-band offset and the interface geometric structure. The interface is found to have structural and electronic similarities to the GaAs-ZnSe(001) system. The very low values obtained for the valence-band offset confirm the ...

1997-01-01

104

Electronic spectra of semiconductor nanocrystals  

Energy Technology Data Exchange (ETDEWEB)

Semiconductor nanocrystals smaller than the bulk exciton show substantial quantum confinement effects. Recent experiments including Stark effect, resonance Raman, valence band photoemission, and near edge X-ray adsorption will be used to put together a picture of the nanocrystal electronic states.

1993-12-31

105

Bulk-sensitive high-resolution photoemission study of a temperature-induced valence transition system EuPd{sub 2}Si{sub 2}  

Energy Technology Data Exchange (ETDEWEB)

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

2004-07-01

106

Average neutron resonance parameters and radiative capture cross sections for the isotopes of molybdenum  

International Nuclear Information System (INIS)

The neutron capture cross sections of the stable molybdenum isotopes have been measured with high energy resolution (#DELTA#E/E < approximately 0.2%), between 3 and 90 keV neutron energy, at the 40 m station of ORELA. Average resonance parameters are extracted for s- and p-wave resonances. The s-wave neutron strength function is close to 0.5x10"-"4 for all isotopes, but the p-wave strength function exhibits a well defined peak near A approximately 95. Both s- and p-wave radiative widths decrease markedly as further neutrons are added to the closed shell. The p-wave radiative widths are generally greater than the s-wave widths showing the presence of non-statistical #gamma#-decay mechanisms. Valence neutron theory fails to explain the magnitude of the p- to s-wave radiative width disparity and doorway state processes are invoked. In particular, the data for "9"8Mo appear to violate the usual valence theory, since the correlations between ...

107

Neutron resonances in /sup 100/Mo and valence neutron capture  

Science.gov (United States)

Neutron resonance interactions with /sup 100/Mo were studied at a time-of-flight facility. The transmission of two oxide samples (97.4% /sup 100/Mo) was measured at a 78.20 m flight path and the neutron capture cross section was measured at 40.12 m. Resonance analyses yielded parameters of 124 resonances. Capture ..gamma..-ray spectra from 11 resolved resonances were measured with a Ge(Li) detector at a 10.45 m flight path. In contrast to neighboring nuclei, partial radiation widths of strong p-wave resonances are not in agreement with valence model predictions.

1979-07-01

108

Measurement of AlP/GaP (001) heterojunction band offsets by x-ray photoemission spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

X-ray photoemission spectroscopy has been used to measure the valence band offset {Delta}E{sub v} for the AlP/GaP (001) heterojunction interface. The heterojunction samples were prepared by molecular-beam epitaxy. A value of {triangle}E{sub v}=0.43 eV is obtained (staggered band alignment, with AlP valence band below that of GaP). 24 refs., 8 figs., 1 tab.

1993-07-01

109

PRODUCTION ENGINEERING MEASURE RELIABILITY ...  

Science.gov (United States)

... without the problem of purple plague. The Au-Ni-In evaporated ... surface and bonding degradation (purple plague) St step-stress ...

1963-09-30

110

Cleaning Aged EPDM Rubber Roofing Membrane Material for ...  

Science.gov (United States)

... 5. The results of the bond strength measurements were compared to the surface cleanness of the aged EPDM as determined by the specified ...

1992-08-01

111

Transient sheath overvoltages in armored power cables  

Energy Technology Data Exchange (ETDEWEB)

This paper is concerned with methods of limiting the build-up of transient voltages between sheath and armor in long armored power cables. Calculations by a frequency dependent cable model demonstrate that this voltage can be efficiently limited to an acceptable level by introducing sheath-armor bondings at regular intervals, or by using a semiconductive sheath-armor interlayer. The paper investigates the required minimum length between bondings, as well as the required conductivity of the sheath-armor interlayer if the use of bondings is to be avoided.

1996-07-01

112

The influence of intramolecular H-bond on chromatographic behavior of phenylalkylamines  

British Library Electronic Table of Contents (United Kingdom)

The thermodynamic characteristics of adsorption on the surface of graphitized thermal carbon black at 300 K were determined by the molecular statistical method for three phenylalklylamines. The influence of the intramolecular H-bond on the conformation of the molecules compared with structurally related n-alkyl-benzenes was considered. It was shown that the conformations of the molecules could influence chromatographic retention. Conformational isomers stabilized by intramolecular H-bonds were found to retain their structure in adsorption on graphitized thermal carbon black.

2009-01-01

113

The influence of intramolecular H-bond on chromatographic behavior of phenylalkylamines  

Science.gov (United States)

The thermodynamic characteristics of adsorption on the surface of graphitized thermal carbon black at 300 K were determined by the molecular statistical method for three phenylalklylamines. The influence of the intramolecular H-bond on the conformation of the molecules compared with structurally related n-alkyl-benzenes was considered. It was shown that the conformations of the molecules could influence chromatographic retention. Conformational isomers stabilized by intramolecular H-bonds were found to retain their structure in adsorption on graphitized thermal carbon black.

2009-04-01

114

Modulation of the axial water hydrogen-bonding properties by chemical modification of the substrate in resting state, substrate-bound heme oxygenase from Neisseria meningitidis; Coupling to the distal H-bond network via ordered water molecules  

UK PubMed Central (United Kingdom)

The hydrogen bonding of ligated water in ferric, high-spin, resting-state substrate complexes of heme oxygenase from Neisseria meningitidis has been systematically perturbed...Full Text Available

2006-05-17

116

Dielectric studies of hydrogen bonded ternary systems: Acetonitrile+alcohols+benzene  

British Library Electronic Table of Contents (United Kingdom)

Any molecule which has a hydrogen atom attached directly to oxygen or nitrogen is capable of hydrogen bonding. The molecular complexes formed by hydrogen have particularly attracted considerable attention to understand the nature of the bond. The hydrogen bonded complexes formed by acetonitrile with certain alcohols such as tertiary butyl alcohol, isoamyl alcohol, cyclohexyl alcohol, hexyl alcohol and diethylene glycol in benzene were studied. The dipole moments of 1:1 complexes of the above said systems were determined at 308K. The dipolar increments for these systems were computed from the bond angle data available from molecular orbital studies. All these studied systems show that polarization interaction dominates in all the complexes.

2010-01-01

117

Comparison of interface evolution of ultrasonic aluminum and gold wire wedge bonds during thermal aging  

British Library Electronic Table of Contents (United Kingdom)

Ultrasonic gold and aluminum wire wedge bonding are widely used for electrical and signal interconnections of the integrated circuit chip packages. In this paper, based on the metallurgical theories and thermal aging test methods, the long-term thermal reliabilities of gold and aluminum wire wedge bonding on aluminum and Au/Ni/Cu pads, were investigated, respectively. At 200degreeC, the Au/Al bond interfaces evolved little when the storage time was less than 48h; with the aging time increasing, the interfacial intermetallic compounds (IMC) grew up from the pad (vertical growth); the primary compounds were Au5Al2 near the bond toe and heel, and Au2Al at the periphery. Then, the thickness of IMC was unchanged, and extended horizontally (lateral growth), Au5Al2 transformed into more stable Au...

2007-01-01

118

Bonding of the Inner Tracker Silicon Microstrip Modules  

CERN Document Server

Microbonding of the CMS Tracker Inner Barrel (TIB) and Tracker Inner Disks (TID) modules was shared among six different Italian Institutes. The organization devised and the infrastructure deployed to handle this task is illustrated. Microbonding specifications and procedures for the different types of TIB and TID modules are given. The tooling specially designed and developed for these types of modules is described. Experience of production is presented. Attained production rates are given. An analysis of the microbonding quality achieved is presented, based on bond strengths measured in sample bond pull tests as well as on rates of bonding failures. Italian Bonding Centers routinely performed well above minimum specifications and a very low global introduced failure rate, at the strip level, of only $\\sim$0.015 \\% is observed.

2008-01-01

119

Resin-infiltrated dentin layer formation of new bonding systems.  

Science.gov (United States)

The purpose of this study was to evaluate the resin-dentin interfacial morphology and shear bond strength of several new and experimental dentin bonding systems classified as single-bottle/total etch, multi-step/total etch, and self-etching. Class 1 and 5 cavities were prepared from freshly extracted permanent molars and restored with composite resin. Each bonded sample was cross sectioned and one-half was completely demineralized and deproteinized, while the other half was polished along the cut surface to permit measurement of the thickness of resin-infiltrated dentin layer (RIDL) within intertubular dentin (iRIDL) and around the peritubular walls (pRIDL) of resin tags by SEM. Shear bond strength was measured for all the systems 2 minutes after photocuring. SEM showed iRIDL and resin tags of different morphology depending on material and dentin location. The iRIDL was thinner in superficial dentin and ...

120

Synthesis, structure, and spectroscopic properties of ortho-metalated platinum(II) complexes  

Energy Technology Data Exchange (ETDEWEB)

The ortho-metalated Pt(II) complexes Pt(ppy)(CO)Cl (1), Pt(ptpy)(CO)Cl (2), and Pt(ppy)(Hppy)Cl (3) (where ppy and ptpy are respectively the ortho-C-deprotonated forms of 2-phenylpyridine and 2-p-tolylpyridine and Hppy is 2-phenylpyridine) have been prepared. The CO ligand is coordinated trans to the nitrogen atom of the ortho-metalated ligand and exerts a strong trans effect resulting in a relatively long Pt-N bond [2.114(19) {angstrom}]. This structure shows both the bidentate ppy ligand and the monodentate Hppy with the nitrogens of these ligands trans to each other. The UV/vis electronic absorption spectra of 1-3 have intense bands in the near-UV region ({approximately}375 nm) which have been assigned as metal to ligand charge transfer (MLCT) transitions, and higher energy bands were assigned as ligand-centered transitions. Each complex exhibits relatively long-lived structured emissions in the solid state at ambient temperature and at 77 K ...

1995-04-26

121

Syntheses and crystal structures of the compounds In_3_._7Mo_1_5S_1_9, In_1_._6Rb_2Mo_1_5S_1_9, In_2_._2CsMo_1_5S_1_9 and ScTl_2Mo_1_5S_1_9 containing Mo_6 and Mo_9 clusters  

International Nuclear Information System (INIS)

The new compounds In_3_._7Mo_1_5S_1_9, In_1_._6Rb_2Mo_1_5S_1_9, In_2_._2CsMo_1_5S_1_9, and ScTl_2Mo_1_5S_1_9 have been synthesized by solid-state reaction in sealed molybdenum crucible at about 1250 deg. C. Their crystal structures were solved and refined from X-ray single-crystal data in the hexagonal space group P63/m. Their Mo-S framework consists of an equal mixture of Mo_6S_8S_6 and Mo_9S_1_1S_6 cluster units interconnected through Mo-S bonds. In In_3_._7Mo_1_5S_1_9, the In atoms occupy crystallographically different positions depending on their formal oxidation states of +1 or +3. This was confirmed by replacing partially or totally the monovalent indium by another monovalent cation such as the rubidium, cesium or thallium and the trivalent indium by the scandium to get the new In_1_._6Rb_2Mo_1_5S_1_9, In_2_._2CsMo_1_5S_1_9, and ScTl_2Mo_1_5S_1_9 compounds, respectively.

2004-11-30

122

On the anatomy of the adsorption heat versus loading as a function of temperature and adsorbate for a graphitic surface.  

Science.gov (United States)

In this paper we review and classify the various patterns of isosteric heat versus loading for adsorption of gases on graphitised thermal carbon black at temperatures ranging from below the 3D triple point to temperatures above it, but less than the 3D critical point. We have identified the features of heat curve and highlighted the microscopic origin of these features. The patterns vary with temperature and with the relative strength of the fluid-fluid interaction and solid-fluid interaction. For simple adsorptives (by simple we meant there is no strong association between fluid particles), the heat curve is typified by fluid-fluid attraction and layering phenomena. For adsorptives showing strong association such as water, ammonia and methanol, the heat curve essentially begins below the condensation heat and then approaches it as loading is increased. This is mainly due to the strong hydrogen bonding in these fluids. A third group includes ...

2008-05-24

123

First-principles study of the micro-arrangement of hydrogen atoms and electronic properties of LaNi_5H_x (x: 0.5-7)  

International Nuclear Information System (INIS)

The micro-arrangement of hydrogen atoms and the electronic properties of hydrides LaNi_5H_x (0.5, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0) have been systematically investigated by means of the density functional theory using the full-potential linearized augmented plane wave (FLAPW) method with the generalized gradient approximation (GGA). The calculated results indicate that H atoms prefer to occupy the 12n site in the #alpha# solid solution phase. For the #beta# phase, once the first H atom locates in the basal plane (12n site), and because it is difficult for the second H atom to still locate in the 12n site, the second H atom would prefer to occupy the middle plane site (6m site). When the number of H atoms increases from 3 to 5, they would occupy the other 12n and 6m sites by turns. Furthermore, our optimized data indicate that the structures P3 and P63mc are the most favorable structures of LaNi_5H_6 and LaNi_5H_7, respectively. From the analysis of the densities ...

2008-07-01

124

Valence-electron configuration of Ti and Ni in Ti{sub x}Ni{sub 1-x} alloys from K{beta}-to-K{alpha} X-ray intensity ratio studies  

Energy Technology Data Exchange (ETDEWEB)

K{beta}-to-K{alpha} X-ray intensity ratios of Ti and Ni have been measured in pure metals and in alloys of Ti{sub x}Ni{sub 1-x} (x=0.7, 0.6, 0.5, 0.4 and 0.3) following excitation by 22.69 keV X-rays from a 10 mCi {sup 109}Cd radioactive point source. The valence-electron configurations of these metals were determined by corporation of measured K{beta}-to-K{alpha} X-ray intensity ratios with the results of multiconfiguration Dirac-Fock calculation for various valence-electron configurations. Valence-electron configurations of 3d-transition metals in alloys indicate significant differences with respect to the pure metals. Our analysis indicates that these differences arise from delocalization and/or charge transfer phenomena in alloys. Namely, the observed change of the valence-electron configurations of metals in alloys can be explained with the transfer of 3d electrons from one element to the other ...

2010-06-15

127

Solid state chemistry in catalysis  

Energy Technology Data Exchange (ETDEWEB)

Correlations between structural aspects of solid materials and their behavior as catalysts are relatively recent. This 20-chapter book focuses on understanding of solid-state mechanisms in heterogeneous catalysis and relationship between catalytic behavior and solid state structure, emphasizing catalysis with oxides, sulfides, and zeolites.

1985-01-01

130

A simple dynamic model for solid transport in rotary dryers  

Energy Technology Data Exchange (ETDEWEB)

The solid particle movement in a rotary drum plays an important role in drying processes. The solid distribution in the drum affects the amount of contact surface between the solid and the gas. The retention time of solids influences the time particles can stay in contact with the gas in order to transfer heat and mass. Any heat and mass transfer model for a solid particle dryer must be able to predict solid flowrate and solid hold-up. There have been several reports in the literature regarding the modeling aspects of solid transport in dryers. If the model is developed for model-based control, it must be simple and yet represent dynamics of the system accurately. This paper addresses solid motion modeling and the effects of different variables involved in solid transport ...

2000-05-01

131

Task Statement - NEPP - NASA  

Science.gov (United States)

Commercial introduction of new polymer materials for use as the electrolyte in solid tantalum and solid aluminum electrolytic capacitors is underway. ...

132

Control of Effluent Gases from Solid Waste Processing Using Carbon Nanotubes  

Science.gov (United States)

One of the major problems associated with solid waste processing technologies is the release of

2005-01-01

133

A Review of Test Medium Contamination Effects on Test ...  

Science.gov (United States)

... solid particle contamination. Solid particulate impact is a good mechanism for surface heat transfer augmentation. The aug ...

1998-01-01

134

Report from the third workshop on future directions of solid-state chemistry: The status of solid-state chemistry and its impact in the physical sciences  

British Library Electronic Table of Contents (United Kingdom)

Executive summaryForewordPublic awareness of solid-state chemistry, or more broadly solid-state science and technology rapidly grew along with the transistor revolution and the development of the integrated circuit. We are now at the half-way point in the solid state century [Scientific American The Solid-State Century 1997;8(1) [special issue

2008-01-01

135

Neutron scattering studies of mixed-valence semiconductors  

Energy Technology Data Exchange (ETDEWEB)

Neutron scattering experiments on the mixed-valence (MV) compounds SmB{sub 6} are reported. The inelastic magnetic response of SmB{sub 6} at T = 2 K, measured on a double-isotope single crystal,displays a strongly damped peak at 35 meV corresponding to the inter multiplet transition of Sm{sup 2+}. At lower energies ( h.{omega} {approx_equal} 14 meV), a narrow magnetic excitation is observed, with remarkable scattering-vector and temperature dependences of its intensity. This novel feature is discussed in terms of recent theoretical works describing the formation of an anisotropic local bound state in semiconducting MV materials. If the average samarium valence is decreased by substituting La for Sm, a peak is found to appear at high energies. The elastic magnetic form factor of SmB{sub 6} was determined using polarised neutrons and no significant difference is observed in its Q-dependence with respect to that of pure divalent samarium. This ...

1994-12-31

136

Including the relativistic kinetic energy in a spline-augmented plane-wave band calculation  

International Nuclear Information System (INIS)

The first-order relativistic correction to the kinetic energy of an electron, the mass-velocity term, is not bounded from below. It can, therefore, not be used within a variational framework. To overcome this deficiency we developed a method to include the entire relativistic kinetic energy #sq root#(p"2c"2+m_0"2c"4)-m_0c"2 in a spline-augmented plane-wave band calculation. The first results for silver are quite promising, especially for d and p states: The analysis of the energies of the core states as well as of the valence band structure suggests that the energies of d bands are reproduced within 1 mRy. However, the combination of the relativistic kinetic energy with the Darwin term leads to energies which are too low for s-like valence states by 10 mRy. Therefore, the s and d valence band complex is spread out and the Fermi level is lowered by the same amount as the s states. We expect to overcome these deficiencies in ...

137

Long-term durability of dentin bonds made with a self-etching primer, in vivo.  

Science.gov (United States)

The long-term durability of bonds between adhesive resins and dentin is of significant importance for the longevity of bonded restorations. We carried out an in vivo one-year study to evaluate the durability of resin-dentin bonds in the oral cavity, as well as to test the hypothesis that the adhesive interface would show morphological changes in vivo over time. Very shallow saucer-shaped dentin cavities were prepared in 12 intact teeth of one Japanese monkey (Macaca fuscata) under general anesthesia. The cavities were restored with Clearfil Liner Bond II and Clearfil Photo Posterior resin composite. The teeth were extracted at three different times: immediately, and 180 and 360 days after placement of the restorations. One day after the monkey was killed, specimens of the three time periods were subjected to the micro-tensile bond test at a crosshead speed of 1 mm/min. The surfaces ...

1999-04-01

138

Phonon spectra of A-15 compounds and ternary molybdenum chalcogenides  

International Nuclear Information System (INIS)

A survey is given on studies of the phonon spectra of several A-15 compounds by inelastic neutron scattering on polycrystalline samples. Comparison of the results for V_3Si, V_3Ge, N_3Ga, Nb_3Sn and Nb_3Al at 297 K lead to the conclusion that the interatomic forces are to a good approximation the same for all compounds with 4.75 valence electrons but are reduced by about 20% for those with 4.5 valence electrons. For all compounds investigated a softening of the phonon frequencies on cooling is observed which is most pronounced for those materials with the highest T/sub c/ values. From a comparison of the results with the experimentally determined Eliashberg function of Nb_3Sn information is derived about the energy dependence of the electron-phonon coupling function #alpha#"2.

139

Neutron resonances in "1"0"0Mo and valence neutron capture  

International Nuclear Information System (INIS)

Neutron resonance interactions with "1"0"0Mo were studied at a time-of-flight facility. The transmission of two oxide samples (97.4% "1"0"0Mo) was measured at a 78.20 m flight path and the neutron capture cross section was measured at 40.12 m. Resonance analyses yielded parameters of 124 resonances. Capture #gamma#-ray spectra from 11 resolved resonances were measured with a Ge(Li) detector at a 10.45 m flight path. In contrast to neighboring nuclei, partial radiation widths of strong p-wave resonances are not in agreement with valence model predictions.

140

Effect of pressure on the valence state of Yb in YbPd_2Si_2  

International Nuclear Information System (INIS)

The intermediate valent behaviour of YbPd_2Si_2 has been studied under pressure in the temperature range from 1.2 K to 90 K by using the 84 keV Moessbauer transition in "1"7"0Yb. At 54 kbar and 4.2 K we obtain an increase of the electric field gradient (EFG) by a factor of #approx =# 3. In addition, the EFG varies strongly with temperature, in contrast to the behaviour at ambient pressure. At 1.2 K a change of the hyperfine pattern is observed indicating a magnetic character of the Yb ion. These results provide evidence of a pressure induced change of the valence state close to 3+. (orig.).

141

Calculation of the X-ray emission spectra of VC and VN  

International Nuclear Information System (INIS)

From self-consistent band structure calculations using the 'augmented plane wave'(APW) method, the density of states can be decomposed into local partial (according to azimuthal quantum number l) components, the l-character densities. Within the APW formalism the intensity of X-ray emission spectra is determined by radial transition probabilities and l-character densities of such valence states, which reside inside the same atomic sphere as the core vacancy and whose quantum number l differs by +-1 from the one corresponding to the core state. By taking into account lifetime broadening of the core and valence states and also the instrumental broadening the computed spectra (non-metal K-, vanadium K- and Lsub(III)-spectra) agree well with experiment. (orig.).

142

Preparation and characterization of a novel polymeric based solid-solid phase change heat storage material  

International Nuclear Information System (INIS)

Here we reported a two-step procedure for preparing a novel polymeric based solid-solid phase change heat storage material. Firstly, a copolymer monomer containing a polyethylene glycol monomethyl ether (MPEG) phase change unit and a vinyl unit was synthesized via the modification of hydrogen group of MPEG. Secondly, by copolymerization of the copolymer monomer and phenyl ethylene, a novel polymeric based solid-solid phase change heat storage material was prepared. The composition, structure and properties of the novel polymeric based solid-solid phase change material were characterized by IR, "1H NMR, DSC, WAXD, and POM, respectively. The results show that the novel polymeric based solid-solid phase change material possesses of excellent crystal properties and high phase change enthalpy.

2009-06-01

143

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

Energy Technology Data Exchange (ETDEWEB)

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

1996-11-01

144

Structural origin of optical bowing in semiconductor alloys p  

Energy Technology Data Exchange (ETDEWEB)

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

1983-08-22

145

Structural origin of optical bowing in semiconductor alloys p  

International Nuclear Information System (INIS)

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

146

Ceramic Materials : Physics 130 : Properties of Matter  

Science.gov (United States)

Lecture notes (pdf) on Ceramics is part of a physics course on the properties of matter from the University of Auckland, Department of Chemical and Materials Engineering. The following topics are covered: types of chemical bonding, degree of ionic character, structure of ceramics and crystallography, interstitial sites in different crystal structures, silicate structures, glasses, glass transition temperature, glass viscosity, thermal and mechanical properties of ceramics and glasses, fracture properties of ceramics and processing of ceramic materials. Keywords: ionic bonds; covalent bonds; coordination numbers; thermal shock; grain growth; sintering; green body

2007-02-01

147

TOPIC 02 High Speed Travel - NASA's SBIR & STTR Programs  

Science.gov (United States)

Low-cost fabrication of PMC composite sandwich panels, including metallic surface preparations for bonding the PMC to titanium honeycomb. ...

148

Silicon solar cell assembly  

Science.gov (United States)

A silicon solar cell assembly comprising a large, thin silicon solar cell bonded to a metal mount for use when there exists a mismatch in the thermal expansivities of the device and the mount.

1979-01-01

149

Prediction of Chemicals Ecotoxicity  

International Science & Technology Center (ISTC)

Computer-Aided Prediction of Chemical Ecotoxicity on the basis of Quantitative Structure-Activity Relationships with the Use of Physico-Chemical Descriptors, Including H-bond Parameters

150

Indirect resin composites  

UK PubMed Central (United Kingdom)

Aesthetic dentistry continues to evolve through innovations in bonding agents, restorative materials, and conservative preparation techniques. The use of direct composite restoration in posterior teeth...Full Text Available

2010-10-01

151

Grit-Blast/Silane (GBS) Aluminum Surface Preparation for ...  

Science.gov (United States)

... GRIT-BLAST/SILANE (GBS) ... GRIT-BLAST/SILANE (GBS) ALUMINUM SURFACE PREPARATION FOR STRUCTURAL ADHESIVE BONDING 5b. ...

2003-04-30

152

Fluoride release from an orthodontic glass ionomer adhesive in vitro and enamel fluoride uptake in vivo  

British Library Electronic Table of Contents (United Kingdom)

Introduction The objective of this study was to investigate the in-vitro fluoride release from a glass ionomer orthodontic bonding system (Fuji I, GC Corporation, Tokyo, Japan) over a 2-month period and the in-vivo enamel fluoride uptake after 6 months. Methods Ten metal brackets were bonded with either glass ionomer or composite resin (Transbond XT, 3M Unitek, Monrovia, Calif; Light Cure), which served as controls, to recently extracted molars. The bonded teeth, cut at the level of their roots, were stored in distilled water that was renewed after every fluoride measurement at 1, 3, 7, 30, and 60 days. The in-vitro fluoride release was measured by using a fluoride ion-selective electrode, connected to an ion analyzer. Fifteen pairs of premolars were bonded with metal brackets with either ...

2010-01-01

153

Breakthrough Image of Atomic Bonding Will Advance the Science of New Materials  

Science.gov (United States)

... Schioler (703) 306-1836 lschiole@nsf.gov This material is available primarily for archival purposes ... of superconducting materials. Colossal magnetoresistance materials are those in which the electrical ...

154

BRAZING AND BONDING OF COLUMBIUM, MOLYBDENUM ...  

Science.gov (United States)

... Kingdom Atomic Energy Authority, .... G. .. aphit. J..int. Report No. AERE R/M 165 (April, 1958). (2) Slaughter, G. M., Metallurgy ...

1962-06-11

155

BAM: Diarrheagenic Escherichia coli  

Science.gov (United States)

... Confirm isolates that appear as typical E. coli on L-EMB and are X-gal (+), MUG (+) or (-) and ... Hill, WE, KC Jinneman, PA Trost, JL Bryant, J. Bond and MM Wekell ...

156

Valence determination in EuM_2X_2 compounds: L_I_I_I-edge versus Moessbauer isomer shift  

International Nuclear Information System (INIS)

A comparative study by Eu-L_I_I_I X-ray absorption and "1"5"1Eu-Moessbauer spectroscopy is presented for the EuPd_2_-_xAu_x Si_2 series. Possible ways to distinguish between mixed-valent behaviour and final-state effects in the L_I_I_I-edge spectra are discussed.

1986-07-07

157

Valence determination in EuM/sub 2/X/sub 2/ compounds: L/sub III/-edge versus Moessbauer isomer shift  

Energy Technology Data Exchange (ETDEWEB)

A comparative study by Eu-L/sub III/ X-ray absorption and /sup 151/Eu-Moessbauer spectroscopy is presented for the EuPd/sub 2-x/Au/sub x/ Si/sub 2/ series. Possible ways to distinguish between mixed-valent behaviour and final-state effects in the L/sub II /I-edge spectra are discussed.

1986-12-01

158

The nucleon axial charge in full lattice QCD  

Energy Technology Data Exchange (ETDEWEB)

The nucleon axial charge is calculated as a function of the pion mass in full QCD. Using domain wall valence quarks and improved staggered sea quarks, we present the first calculation with pion masses as light as 354 MeV and volumes as large as (3.5 fm)3. We show that finite volume effects are small for our volumes and that a constrained fit based on finite volume chiral perturbation theory agrees with experiment within 5% statistical errors.

2005-10-13

159

Soft X-ray spectra of amorphous hydrogenated silicon  

Energy Technology Data Exchange (ETDEWEB)

The Si-L X-ray emission spectrum of amorphous hydrogenated silicon (a-Si:H) is presented and discussed. For a qualitative interpretation of the measured spectra cluster calculations of pure Si clusters (SiSi4) and Si clusters with hydrogen (SiSi3H) have been performed using a simplified LCAO-X scheme. In general the level shifts caused by introduction of hydrogen are small compared with the valence band width.

1985-06-01

160

Production of cumulative hadrons in quark models of flucton fragmentation  

International Nuclear Information System (INIS)

Quark models of production of cumulative particles and the EMC effect are analyzed. It is shown that all these models are characterized by a universal relation between the spectrum of cumulative nucleons and the cross section for cumulative particles containing valence quarks of the nucleus. This relation is tested for the deuteron, and the role of secondary nuclear processes for heavy nuclei is discussed. It is noted that the ''sea'' cumulative particles (K"-, p-bar) are particularly important for understanding the nature of the difference between the structure functions of a nucleus and of a free nucleon.

161

Optical spectroscopy of uranium monochalcogenides and monopnictides  

International Nuclear Information System (INIS)

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

1980-12-01

162

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

Energy Technology Data Exchange (ETDEWEB)

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

1987-06-15

163

Cumulative kaon production by 10 GeV protons  

International Nuclear Information System (INIS)

The K"+- and K"-meson cumulative production cross sections are measured at 119"0 in the laboratory system on nuclei Be, Al, Cu and Ta bombarded by 10 GeV protons. Spectra of the K"-mesons consisting of only sea quarks show universal features characteristic of the spectra of cumulative particles, which contain valence quarks. Evidence is obtained for the fact that the energy density in a flucton can exceed the mean nuclear density by an order of magnitude.

164

Cumulative hadron production in quark models of flucton fragmentation  

International Nuclear Information System (INIS)

Quark models of cumulative particle production and EMS effect are analyzed. All the models are characterized by a universal relationship between the spectrum of cumulative nucleons and the cross section of cumulative particles containing valence nuclear quarks. This relationship is tested for a deuteron. The role is discussed played by secondary nuclear processes for heavy nuclei. A special role of ''sea'' cumulative particles (K"-, p-bar) is pointed out in understanding the nature of the difference between the structure functions of a nucleus and of free nucleon.

165

Chemical sensitivity of the Ksub(. beta. )/Ksub(. cap alpha. ) x-ray intensity ratio for 3d elements  

Energy Technology Data Exchange (ETDEWEB)

Chemical influences on the relative Ksub(..beta..)/Ksub(..cap alpha..) x-ray intensity ratio up to five per cent were found for different chemical constitutions of Cr, Mn, Fe and Cu by very precise PIXE measurements. In the discussion of these effects, screening of 3p electrons by a varying 3d valence charge, as well as polarizational effects are of importance.

1982-12-28

166

Chemical sensitivity of the Ksub(#nu#)/Ksub(#alpha#) x-ray intensity ratio for 3d elements  

International Nuclear Information System (INIS)

Chemical influences on the relative Ksub(#nu#)/Ksub(#alpha#) x-ray intensity ratio up to five per cent were found for different chemical constitutions of Cr, Mn, Fe and Cu by very precise PIXE measurements. In the discussion of these effects, screening of 3p electrons by a varying 3d valence charge, as well as polarisational effects are of importance. (author).

1982-12-01

167

Charmonium with three flavors of synamical quarks  

Energy Technology Data Exchange (ETDEWEB)

We present a calculation of the charmonium spectrum with three flavors of dynamical staggered quarks from gauge configurations that were generated by the MILC collaboration. We use the Fermilab action for the valence charm quarks. Our calculation of the spin-averaged 1P-1S and 2S-1S splittings yields a determination of the strong coupling, with {alpha}{sub {ovr MS}}(M{sub Z}) = 0.119(4).

2003-12-23

168

Cerium moment collapse in ternary silicides CePd[sub 2[minus][ital x  

Energy Technology Data Exchange (ETDEWEB)

Cerium [ital L][sub 3] XANES (x-ray-absorption near-edge-structure) spectra were analyzed to separate Ce moment contributions and mixed valence (MV) in complex magnetic silicides CePd[sub 2[minus][ital x

1994-05-01

169

Calculated valence electronic structure of 3d metals for use in the X-ray intensity ratio studies  

Energy Technology Data Exchange (ETDEWEB)

3d occupation numbers of the transition elements corresponding to various types of atomic configurations are calculated by means of the linear muffin-tin orbital (LMTO) method. This data is used with the multiconfiguration Dirac-Fock (MCDF) X-ray intensity ratios to estimate the electron populations of the 3d metals in alloys.

2010-09-15

170

Calculated valence electronic structure of 3d metals for use in the X-ray intensity ratio studies  

International Nuclear Information System (INIS)

3d occupation numbers of the transition elements corresponding to various types of atomic configurations are calculated by means of the linear muffin-tin orbital (LMTO) method. This data is used with the multiconfiguration Dirac-Fock (MCDF) X-ray intensity ratios to estimate the electron populations of the 3d metals in alloys.

2010-09-01

171

Behavioral Stress May Increase the Rewarding Valence of Cocaine-Associated Cues Through a Dynorphin/?-Opioid Receptor-Mediated Mechanism without Affecting Associative Learning or Memory Retrieval Mechanisms  

UK PubMed Central (United Kingdom)

Stress exposure increases the risk of addictive drug use in human and animal models of drug addiction by mechanisms that are not completely understood. Mice subjected to repeated forced swim stress...Full Text Available

2010-08-01

172

A study of the photoionisation dynamics of chloromethane and iodomethane  

International Nuclear Information System (INIS)

Angle resolved valence shell photoelectron spectra of chloromethane and iodomethane have been recorded using synchrotron radiation in the photon energy range 14-120eV. These have allowed photoelectron angular distributions and branching ratios to be determined not only for the main bands associated with the single-hole states but also for the satellite structure due to many-electron effects. The continuum multiple scattering approach has been used to calculate photoelectron asymmetry parameters and branching ratios for the valence orbitals of CH_3Cl and CH_3I, and also for the I 4d subshell. A comparison between the experimental data and the theoretical predictions has enabled the influence of Cooper minima, shape resonances and intershell coupling to be assessed. The asymmetry parameters and branching ratio for the spin-orbit split components of the CH_3I"+X-bar "2E state have been measured and exhibit a spectral behaviour almost identical to ...

2006-08-01

173

5f electron localization in metallic UPd_3  

International Nuclear Information System (INIS)

The electronic structure of UPd_3 has been determined by means of XPS and BIS experiments. The core level line shapes and the valence band spectra of occupied and empty states clearly reveal the localized character of the 5f electrons in this actinide compound. From these spectra their Coulomb correlation energy is found to be about 2 eV. (author).

174

Synthesis, crystal structure and optical properties of a novel sodium lead pentaborate, NaPbB5O9  

International Nuclear Information System (INIS)

A novel sodium lead pentaborate, NaPbB5O9, has been successfully synthesized by standard solid-state reaction. The single-crystal X-ray structural analysis showed that NaPbB5O9 crystallizes in the monoclinic space group P21/c with a=6.5324(10) A, b=13.0234(2) A, c=8.5838(10) A, ?=104.971(10)o, and Z=4. The crystal structure is composed of double ring [B5O9]3- units, [PbO7] and [NaO7] polyhedra. [B5O9]3- groups connect with each other forming two-dimensional infinite ?[B5O9]3- layers, while [PbO7] and [NaO7] polyhedra are located between the layers. [PbO7] polyhedra linked together via corner-sharing O atom forming novel infinite ?[PbO6] chains along the c axis. The thermal behavior, IR spectrum and the optical diffuse reflectance spectrum of NaPbB5O9 were reported. -- Graphical abstract: A new phase, NaPbB5O9, has been discovered in the ternary M2O-PbO-B2O3 (M=alkali-metal) system. The crystal structure consists of a novel infinite ?[PbO6] chains. Display Omitted ...

2011-04-01

175

Electronic structure of face-centred cubic MoO_2: A comparative study by the full potential linearized augmented plane wave method, X-ray emission spectroscopy and X-ray photoelectron spectroscopy  

International Nuclear Information System (INIS)

X-ray emission spectroscopy (XES) and X-ray photoelectron spectroscopy (XPS) methods were employed in the present paper to investigate the electronic structure of face-centred cubic (fcc) molybdenum dioxide, fcc-MoO_2. For the mentioned compound, the XES O K#alpha# and Mo L#beta#_2_,_1_5 bands reflecting the valence O p- and Mo s,d-like states, respectively, were derived and compared on a common energy scale with the XPS valence-band spectrum. For comparison, the similar experimental studies of the electronic structure were made for a usual orthorhombic form of molybdenum trioxide, MoO_3. Band-structure calculations of fcc-MoO_2 were made using the full potential linearized augmented plane wave (FP-LAPW) method. A rather good agreement of the experimental XES and XPS results and the theoretical FP-LAPW data for the electronic properties of fcc-MoO_2 has been achieved in the present paper. A new near-Fermi sub-band was detected on both the XES ...

2008-07-14

176

Thermal NDE method for thermal spray coatings  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a feasibility demonstration of a thermal scanning NDE system for thermal spray coatings. Non-bonds were detected between several types of coatings and their substrates. Aluminum anti-skid coatings having very rough surfaces were included. A technique for producing known non-bond areas for calibrating and demonstrating NDE methods was developed.

1982-01-01

177

The influence of an intramolecular H-bond on the adsorption of sulfur-containing amino acids on graphitized thermal carbon black  

British Library Electronic Table of Contents (United Kingdom)

The thermodynamic characteristics of adsorption of sulfur-containing amino acids and their derivatives on the surface of graphitized thermal carbon black were calculated by the molecular statistical method. The parameters of the atom-atom potential function of intermolecular interaction between the S atom in amino acids and the graphite C atom were determined. It was shown that an intramolecular H-bond influenced the adsorption of amino acids on the surface of graphitized thermal carbon black.

2009-01-01

178

The influence of an intramolecular H-bond on the adsorption of sulfur-containing amino acids on graphitized thermal carbon black  

Science.gov (United States)

The thermodynamic characteristics of adsorption of sulfur-containing amino acids and their derivatives on the surface of graphitized thermal carbon black were calculated by the molecular statistical method. The parameters of the atom-atom potential function of intermolecular interaction between the S atom in amino acids and the graphite C atom were determined. It was shown that an intramolecular H-bond influenced the adsorption of amino acids on the surface of graphitized thermal carbon black.

2009-04-01

179

Selective epoxidation of allylic alcohols with a titania-silica aerogel  

Energy Technology Data Exchange (ETDEWEB)

An amorphous mesoporous titania-silica aerogel (20 wt%TiO{sub 2} - 80 wt% SiO{sub 2}) and tert.-butylhydroperoxide (TBHP) have been used for the epoxidation of various allylic alcohols. Allylic alcohols possessing an internal double bond were more reactive than those with a terminal C=C bond. Epoxide selectivities could be improved by addition of (basic) zeolite 4 A and NaHCO{sub 3} to the reaction mixture. (orig.)

1998-12-31

180

Reactive metal brazing of aluminum nitride  

Energy Technology Data Exchange (ETDEWEB)

The addition of titanium to eutectic braze compositions causes these alloys to readily wet and bond to A1N ceramics. Electron microscopic characterizations of the metal-ceramic interfaces reveal the presence of TiN, along with other Ti- and Al-containing phases. The formation of such interfacial reaction products is an additional thermodynamic driving force for the creation of useful metal-ceramic bonds. 12 refs., 4 figs., 1 tab.

1990-01-01

181

Quantum molecular dynamics and molecular interactions studied by NMR and INS[Nuclear magnetic resonance; Proton tunnelling; Hydrogen bond  

Energy Technology Data Exchange (ETDEWEB)

The wavefunction of a particle extends into the classically forbidden barrier region of the potential energy surface. The consequence of this partial delocalisation is the phenomenon of quantum tunnelling, an effect which enables a particle to penetrate a potential barrier of magnitude greater than the energy of the particle. The tunnelling probability is an exponential function of the particle mass. The effect is therefore an important contribution to the behaviour of light atoms, in particular the proton. The hydrogen bond has long been appreciated to be an essential component of many biological and chemical systems, and the proton transfer reaction in the hydrogen bond is fundamental to many of these processes. The proton behaviour in the hydrogen bonds of benzoic acid, acetylacetone and calix-4-arene has been studied. A variety of techniques, both experimental and computational, were adopted for the study of the three ...

2002-07-01

182

Novel inorganic hydrogen-bonded crystals with nonlinear optical properties  

International Nuclear Information System (INIS)

Four inorganic hydrogen-bonded crystals with second-order nonlinear properties have been discovered: K_4LiH_3(SO_4)_4, Na_2SeO_4#centre dot#H_2SeO_3#centre dot#H_2O, Cs_1_,_5Li_1_,_5H(SO_4)_2 and NH_4HSeO_4. (author)

2000-01-01

183

Joined ceramic product  

Energy Technology Data Exchange (ETDEWEB)

According to the present invention, a joined product is at least two ceramic parts, specifically bi-element carbide parts with a bond joint therebetween, wherein the bond joint has a metal silicon phase. The bi-element carbide refers to compounds of MC, M.sub.2 C, M.sub.4 C and combinations thereof, where M is a first element and C is carbon. The metal silicon phase may be a metal silicon carbide ternary phase, or a metal silicide.

2001-01-01

184

Growth markets  

Energy Technology Data Exchange (ETDEWEB)

The results of Independent Energy's Financial Rankings survey for 1992 as well as the second half of 1992 showed increased activity in almost every category. In stronger showing was evident in all categories except corporate finance and revenue bonds. The total amount of project finance equity and debt, corporate finance and revenue bonds reported in 1992 was nearly $16 billion - up 45% from what was reported in 1991.

1993-03-01

185

Evaluation of cathodic dis-bonding of three types of coatings by DC and AC methods  

Energy Technology Data Exchange (ETDEWEB)

For the protection of buried steel pipeline, it is common practice to coat the pipelines with highly insulating coating and apply a cathodic current to insulate the pipe from the aggressive environment. Cathodic current protects holidays or damaged area of coating which required less current than would be needed for an uncoated pipe, but because of the cathodic reactions evolution will be taken H{sub 2} and OH{sup -} on holidays which exposed metal to the environment place. This effect is to cause loss bond of coating around the holidays called cathodic dis-bonding. In this paper we measured cathodic dis-bonding of three types of coatings at - 1.5 V(Cu/CuSO{sub 4}) according to ASTM G8. We studied on cathodic dis-bonding resistance of petroleum-base, coal tar-base and polyethylene plastic tape coatings. After 30 days immersion in electrolyte it was found that the cathodic disbanding resistance of ...

2004-07-01

186

A precise structure redetermination of nickel ammonium sulfate hexahydrate, Ni(H_2O)_6.2NH_4.2SO_4  

International Nuclear Information System (INIS)

The Ni(H_2O)_6 ion is located at an inversion center. Six octahedral water molecules surround the Ni"I"I ion and form hydrogen bonds with the sulfate groups. Each ammonium group binds to the sulfate groups through hydrogen bonds. (orig.).

1994-05-01

187

4.5S RNA is encoded by hundreds of tandemly linked genes, has a short half-life, and is hydrogen bonded in vivo to poly(A)-terminated RNAs in the cytoplasm of cultured mouse cells.  

UK PubMed Central (United Kingdom)

4.5S RNA is a group of RNAs 90 to 94 nucleotides long (length polymorphism due to a varying number of UMP residues at the 3' end) that form hydrogen bonds with poly(A)-terminated RNAs isolated from...Full Text Available

1986-05-01

188

2DIR spectroscopic studies on cholic acid  

Science.gov (United States)

Based on our cryogenic FT-IR spectroscopic studies of hydrogen bonds in cholic acid, the two-dimensional FT-IR spectroscopy was applied to enhance our understanding of the hydrogen bonds. Fine spectral structures were revealed by asynchronous 2D FT-IR spectra. The co-relationship among various bands was discussed according to the synchronous 2D FT-IR spectra. .

2000-03-01

189

A Spindle Cell Predominant Pancreatic Solid-pseudopapillary Tumor  

UK PubMed Central (United Kingdom)

A hitherto unrecognized variant of solid-pseudopapillary tumor (SPT) of the pancreas is reported. The tumor presented in the pancreatic tail of a 44-year-old female patient. It was a well-defined, solid...Full Text Available

2008-08-30

190

40 CFR 261.2 - Definition of solid waste.  

Science.gov (United States)

...2009-07-01 false Definition of solid waste. 261.2 Section 261.2 Protection...PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) IDENTIFICATION AND LISTING OF HAZARDOUS WASTE General § 261.2 Definition...

2009-07-01

191

Real-Time Price Discovery in Global Stock, Bond and Foreign Exchange Markets  

DEFF Research Database (Denmark)

Using a unique high-frequency futures dataset, we characterize the response of U.S., German and British stock, bond and foreign exchange markets to real-time U.S. macroeconomic news. We find that news produces conditional mean jumps; hence high-frequency stock, bond and exchange rate dynamics are linked to fundamentals. Equity markets, moreover, react differently to news depending on the stage of the business cycle, which explains the low correlation between stock and bond returns when averaged over the cycle. Hence our results qualify earlier work suggesting that bond markets react most strongly to macroeconomic news; in particular, when conditioning on the state of the economy, the equity and foreign exchange markets appear equally responsive. Finally, we also document important contemporaneous links across all markets and countries, even after controlling for the effects of macroeconomic news.

2007-01-01

192

Bond strength and ultimate tensile strength of resin composite filled into dentine cavity; effect of bulk and incremental filling technique  

British Library Electronic Table of Contents (United Kingdom)

ObjectivesThe aim of this study was to evaluate the relationship between micro-tensile bond strength (mTBS) and ultimate tensile strength (UTS) of resin composite restorations in cavities filled by a bulk or incremental technique using the micro-tensile test.MethodsClass I cavities (4mm long, 3mm wide, 3mm deep) were prepared into dentine of sixteen human molars. All cavities were bonded with Clearfil SE Bond and restored with AP-X composite with either a bulk or incremental technique. After storage in water for 24h, the teeth were vertically sectioned to yield two slabs. Each slab was sectioned into three sticks. Sticks of one slab were trimmed into an hourglass of 0.7mm2 area at resin-dentine interface for bond strength measurement while the other sticks were trimmed at the centre of the...

2008-01-01

193

Study of radiation chemistry in solids using solid hydrogen  

Energy Technology Data Exchange (ETDEWEB)

Having simple and highly symmetric structure, solid hydrogen is a useful matrix on the study of radiation-chemical processes in solid phase which have been less understood in previous studies. We have found three outstanding findings: resonance effects on the tunneling reaction H+H{sub 2} {yields} H{sub 2} + H, effects of pressure on the dissociation and recombination of H{sub 2} molecules in solid hydrogen, and high-resolution ESR spectroscopy using a solid parahydrogen matrix. (author)

2002-03-01

194

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

UK PubMed Central (United Kingdom)

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

2010-10-01

195

Solid serous microcystic adenoma of the pancreas  

UK PubMed Central (United Kingdom)

BackgroundCystic neoplasms of the pancreas are less common than solid tumors, and portend a better prognosis. They can be divided into serous and mucinous subtypes, with the former...Full Text Available

196

Solid Waste & Financial Assistance Program  

Science.gov (United States)

This program deals with solid waste disposal with topics/services covering: Reusable Building Materials and Large Household Items Exchange, Beneficial Use Determination, Biosolids, Certification, Compost Facil...

197

Gasless Combustion of Solid Fuel Mixtures  

International Science & Technology Center (ISTC)

Investigation of the Macrokinetics and Energy of Self-Oscillatory Processes of Gasless Combustion of Solid Fuel Mixtures Proposed for the Design of Short-Term Thermal and Electrical Sources

198

A Theoretical Solid Oxide Fuel Cell Model for - The NASA Glenn ...  

Science.gov (United States)

May 31, 2011 ... A Theoretical Solid Oxide Fuel Cell Model for System Controls and Stability Design AUTHOR(S): Kopasakis, George; Brinson, Thomas; Credle, ...

200

Integrated Models for Solid Waste Management in Tourism Regions: Langkawi Island, Malaysia  

Science.gov (United States)

The population growth, changing consumption patterns, and rapid urbanization contribute significantly to the growing volumes of solid waste that are generated in urban settings. As the rate of urbanization increases, demand on the services of solid waste management increases. The rapid urban growth in Langkawi Island, Malaysia, combined with the increasing rates of solid waste production has provided evidence that the traditional solid waste management practices, particularly the methods of waste collection and disposal, are inefficient and quite nonsustainable. Accordingly, municipal managers and planners in Langkawi need to look for and ...

2011-09-04

201

Estimation of hydrogen bondings in coal utilizing FTir and differential scanning calorimetry (DSC); FTir to DSC wo mochiita sekitannai suiso ketsugo no teiryoteki hyoka no kokoromi  

Energy Technology Data Exchange (ETDEWEB)

With an objective to know coal condensation structure which has influence on coal conversion reaction, an attempt was made on quantitative evaluation of hydrogen bonding in coal. Using as test samples the VDC made from Taiheiyo coal swollen by tetralin and vacuum-dried, and its pyrolyzed char, DSC measurement and Fourier transform infrared spectroscopy (FT) were performed. An FT spectrum comparison revealed that the VDC swollen at 220{degree}C has the hydrogen bonding relaxed partly from the original coal. However, since the change is in a huge coal molecular structure restraining space, it has stopped at relaxation of the bonding energy without causing separation as far as free radicals. On the other hand, the DSC curve shows that the VDC has slower endothermic velocity than the original coal. In other words, the difference in heat absorption amounts in both materials is equivalent to the difference of enthalpy ({Delta} H) ...

1996-10-28

202

Volatilization of fluorides from solid uranium(IV)fluoride  

International Nuclear Information System (INIS)

... deposition evaporation fission products fluorides iodine 134 laboratory

1971-02-01

204

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-01-15

205

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

International Nuclear Information System (INIS)

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

2010-01-01

208

Report of the Government Industrial Research Institute, Osaka, No. 388, February 1993. High lithium ion conductive solid electrolytes  

Energy Technology Data Exchange (ETDEWEB)

Research investigating applicability of lithium salts for solid electrolyte batteries was described. The studies included determinations of lithium ion conductivities in solid electrolyte systems based on Li4SiO4, LiTi2(PO4)3, and ceramic materials. Research on all solid state lithium cells utilizing TiS2 NiPS3 electrodes was also reported.

1993-01-01

210

Plasma Technologies for Fuel Processing  

International Science & Technology Center (ISTC)

Plasma Technologies of Solid Fuels Processing for Power Engineering and Metallurgy

217

Gravity settling  

Science.gov (United States)

Solids are separated from a liquid in a gravity settler provided with inclined solid intercepting surfaces to intercept the solid settling path to coalesce the solids and increase the settling rate. The intercepting surfaces are inverted V-shaped plates, each formed from first and second downwardly inclined upwardly curved intersecting conical sections having their apices at the vessel wall.

1979-01-01

220

The effects of laser etching on shear bond strength at the titanium ceramic interface  

British Library Electronic Table of Contents (United Kingdom)

Statement of problem The use of titanium has increased for metal ceramic restorations, as well as for use in titanium implants, with developments in CAD/CAM technology. Some surface treatments of titanium have been introduced to enhance the titanium bond strength to low-fusing porcelains; however, a more reliable, easily used dental laboratory method has not been established. Purpose The purpose of this study was to compare the effect of laser etching as a titanium surface treatment with 3 other surface treatments (machining, airborne-particle abrasion, and acid etching), evaluating their ability to enhance the bond strength between a titanium substrate and porcelain. Material and methods A total of 64 specimen rods of commercially pure titanium (ASTM grade 2, 20 mm in length and 5.7 mm in...

2009-01-01

221

Studies of the fundamental nature of catalytic acidity, sites, and intermediates: Progress report for period August 1, 1987-July 31, 1988  

Energy Technology Data Exchange (ETDEWEB)

Neopentane, because of its unique structural features, was found to be a useful probe for the assay of the acidity of various zeolites. The C-C bond was attacked by catalyst protons yielding CH/sub 4/ and the isobutyl carbenium ion in equal quantities. The latter either decomposed to produce isobutene or underwent secondary reactions. New avenues for reaction were opened with isobutane. The reaction of the Bronsted protons with the tertiary CH bonds produced H/sub 2/ and the same isobutyl carbenium ion. Hydride ion transfer of the same tertiary hydrogen to existing carbenium ions also occurred and the results showed that about half of the reaction was carried by this pathway. As with Neopentane, the C-C bond could also be attacked yielding the sec-propyl carbenium ion. These tools are being further developed.

1988-06-01

222

Repair of floating offshore units using bonded fibre composite materials  

British Library Electronic Table of Contents (United Kingdom)

On ships, tankers and similar vessels structural defects such as cracks and corrosion damage are typically repaired by welding. However, welding is unwanted hotwork on floating offshore units (FOUs) such as floating, production, storage and offloading (FPSO) and floating, storage and offloading (FSO) vessels because it requires shutdown of parts of the vessel thus resulting in expensive production delays. Bonded fibre composite material patch repairs can be used as an alternative to overcome the hazards of hotwork associated with welding. The patches are bonded over the defect and the integrity of the original structure is hence restored. The patch repair technology can also be utilised to provide upgrades, such as life extensions and higher design requirements. A recommended practice (RP)...

2009-01-01

223

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

International Nuclear Information System (INIS)

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

224

Materials Research Related to W-band Cavity Construction  

Energy Technology Data Exchange (ETDEWEB)

Low power rf measurements, S11, of electro-discharge machined (EDM) diffusion bonded mm-wave traveling wave rf cavities were not in satisfactory agreement with electromagnetic simulations. During subsequent mechanical inspection, the cell-to-cell iris were found to be distorted. This led to a series of systematic experiments to study the mechanical properties of oxygen free high conductivity Copper (OFHC) and Glidcop AL-15. Results of these studies which include cell-to-cell iris distortion, EDM machining accuracies, surface quality, and the results of different bonding techniques are presented. The results of our mechanical studies are used to develop a set of mechanical design constraints for a second series of constant impedance W-Band structures that also used wire EDM and high temperature bonding for their manufacture.

2000-10-18

225

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

British Library Electronic Table of Contents (United Kingdom)

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

2011-01-01

226

Electronic properties of Nb_3Ge and Nb_3Al from self-consistent pseudopotentials. II. Bonding, electronic charge distributions, and structural transformation  

International Nuclear Information System (INIS)

Electron charge distributions are presented for Nb_3Ge, Nb_3Al, and two other hypothetical A-15 structures. Results indicate that the bonding in these materials is mainly metallic in character with some covalentlike bonding between Nb-chain atoms. We find significant coupling between neighboring chains and also between chain atoms and atoms at the cubic site. Comparison is made with various theoretical models. Investigation of the charge character of states near E/sub F/ suggests further developments in current theories on the structural transformation of A-15 compounds. The effect of chain dimerization on electronic states and charge distribution of Nb_3Ge is also investigated.

227

Electronic properties of Nb3Ge and Nb3Al from self-consistent pseudopotentials. II. Bonding, electronic charge distributions, and structural transformation  

Science.gov (United States)

Electron charge distributions are presented for Nb3Ge, Nb3Al, and two hypothetical A-15 structures. Results indicate that the bonding in these materials is mainly metallic in character with some covalentlike bonding between Nb-chain atoms. We find significant coupling between neighboring chains and also between chain atoms and atoms at the cubic site. Comparison is made with various theoretical models. Investigation of the charge character of states near EF suggests further developments in current theories on the structural transformation of A-15 compounds. The effect of chain dimerization on electronic states and charge distribution of Nb3Ge is also investigated.

1979-02-01

228

Electronic properties of Nb/sub 3/Ge and Nb/sub 3/Al from self-consistent pseudopotentials. II. Bonding, electronic charge distributions, and structural transformation  

Science.gov (United States)

Electron charge distributions are presented for Nb/sub 3/Ge, Nb/sub 3/Al, and two other hypothetical A-15 structures. Results indicate that the bonding in these materials is mainly metallic in character with some covalentlike bonding between Nb-chain atoms. We find significant coupling between neighboring chains and also between chain atoms and atoms at the cubic site. Comparison is made with various theoretical models. Investigation of the charge character of states near E/sub F/ suggests further developments in current theories on the structural transformation of A-15 compounds. The effect of chain dimerization on electronic states and charge distribution of Nb/sub 3/Ge is also investigated.

1979-02-15

229

Density functional theory studies of energetic nitrogen-rich derivatives of substituted carbon-bridged diiminotetrazoles  

British Library Electronic Table of Contents (United Kingdom)

Density functional theory calculations were performed to study the effects of different substituents and bridge groups on the heats of formation (HOFs), thermal stability, and detonation properties for a series of diiminotetrazole derivatives. The isodesmic reaction method was employed to calculate the HOFs of the derivatives using total energies obtained from electronic structure calculations. The bond dissociation energies and bond orders for the weakest bonds were analyzed to investigate the thermal stability of the diiminotetrazole derivatives. The detonation velocities and pressures were evaluated by using the semiempirical Kamlet-Jacobs equations, based on the theoretical densities and HOFs. These results provide basic information for the molecular design of novel high-energy density...

2011-01-01

230

Correlations of /sup 195/Pt-/sup 31/P coupling constants with platinum-ligand and platinum-platinum bond lengths in platinum(I) dimers and in related platinum(II) complexes  

Energy Technology Data Exchange (ETDEWEB)

The availability of dimeric Pt(I) complexes with bridging bis(diphenylphosphino)methane ligands, (L--L')/sup n+/, presents an opportunity to study the physical properties and reactivity of metal-metal bonds as a function of the ligand trans to it with a minimum of competing variables. Several interesting trends of Pt-P coupling constants with the Pt-L and Pt-Pt bond lengths in Pt(I) dimers, (L--L')/sup n+/, and structurally related Pt(II) complexes are reported here. The data indicate that the Pt-P coupling constants continue to be sensitive indicators of not only the structure and stereochemistry of platinum phosphine complexes but also the electronic and steric influences of the ligand in such complexes, 23 references, 1 figure, 4 tables.

1986-03-12

231

X-ray and UV-light irradiation effects on oxide superconducting thin films  

International Nuclear Information System (INIS)

Oxide superconducting thin films were irradiated with X-rays and ultra-violet (UV) light, and induced radiation effects on electrical and chemical properties were examined by transport measurement, X-ray diffraction analysis (XRD), diamagnetization measurement and X-ray photoemission spectroscopy (XPS). After irradiation for ErBa_2Cu_3O_x films with X-rays emitted from a Rh tube for 100 hours, superconductivity was remarkably damaged, destroying the zero-resistance state. The UV-light irradiation for Bi_2Sr_2CaCu_2O_x films was performed in He gas of about 500 Pa with a low pressure mercury lamp. The superconductivity was gradually degraded with the UV irradiation time up to 70 minutes. In both cases, adequate oxygen-annealing treatments restored superconductivity. The X-ray photoemission spectra showed that the mean Cu valence of the films was decreased approximately from +2 to +1 by the irradiation. From these results we can find that irradiation with the X-ray ...

232

Spectral properties of actinide materials: Charge density self-consistent LDA+Hubbard I method in FP-LAPW basis  

International Nuclear Information System (INIS)

We provide a numerically efficient procedure to perform LDA+Hubbard I calculations including self-consistency over the charge density in the FP-LAPW basis. The method is applied to Pu, Am, and PuAm and PuCe alloys. Our results for valence photoemission spectra (PES) agree with experimental data and with previous LDA+DMFT calculations. Analysis of the J=5/2 and J=7/2 contributions to the f-occupation supports the intermediate-coupling picture of f-states in heavy actinides. The electronic specific heat coefficient is calculated for PuAm and PuCe alloys in reasonable agreement with recent experiments. We show that Pu atoms keep their mixed-valence character in these alloys. Next, we study electronic and spectral properties of Pu-based superconductor PuCoGa_5 and obtain good agreement with experimental PES. Finally, we analyze surface effects. In Pu monolayer, we find substantial modification of PES due to 5f-electron localization consistent with ...

2010-03-21

233

Potassium deposition on a thiophene-terminated alkanethiol monolayer  

International Nuclear Information System (INIS)

Potassium deposition in ultrahigh vacuum on 12-(3-thienyl)dodecanethiol monolayers assembled on gold surfaces has been investigated using X-ray and ultraviolet photoelectron spectroscopies (XPS and UPS). Angle-resolved XPS indicates that initially deposited potassium penetrates the self-assembled monolayer (SAM) and diffuses to the SAM/Au interface. Even after large metal doses, the presence of thiophene ring valence electronic states in the UPS spectra confirms that most of the thiophene rings (at the SAM/vacuum interface) are not covered by potassium. The binding energy shifts of the thiophene ring valence states and the C1s and thiophene S2p peaks, referenced to the Fermi level, are due to the work function changes of the gold substrate. This indicates that these electronic states are pinned to the vacuum level, in contrast to the thiolate S2p orbital, which is pinned to the Fermi level. For large potassium doses, the appearance of new ...

2009-05-01

234

Optoelectronic and excitonic properties of oligoacenes and one-dimensional nanostructures.  

Energy Technology Data Exchange (ETDEWEB)

The optoelectronic and excitonic properties in a series of linear acenes are investigated using range-separated methods within time-dependent density functional theory (TDDFT). In these highly-conjugated systems, we find that the range-separated formalism provides a substantially improved description of excitation energies compared to conventional hybrid functionals, which surprisingly fail for the various low-lying valence transitions. Moreover, we find that even if the percentage of Hartree-Fock exchange in conventional hybrids is re-optimized to match wavefunction-based CC2 benchmark calculations, they still yield serious errors in excitation energy trends. Based on an analysis of electron-hole transition density matrices, we also show that conventional hybrid functionals overdelocalize excitons and underestimate quasiparticle energy gaps in the acene systems. The results of the present study emphasize the importance of a range-separated and ...

2010-09-01

235

Charge redistribution in ion-beam-mixed Pd-Ag alloys  

Science.gov (United States)

Charge flow and valence/d-band behavior in ion-beam-mixed (IBM) Pd1-xAgx (x = 0.5-0.9) alloys have been studied by X-ray photoemission measurement of the valence bands and of core-level binding energy shifts and X-ray absorption near-edge structure. We correlated the observed Ag 3d5/2 core-level shifts in these IBM alloys, relative to the elemental Ag, with the White Line area changes at the Pd and Ag L3-edge to investigate the charge redistribution at the Ag site. The results indicate that there is a decrease in sp-like conduction electron and a negligible change in the number of d-electrons at the Ag site upon alloying. These results are in line with our previous results in which Pd gains d-charges and loses sp-type charges. This electron redistribution due to hybridization in the alloy leads small net charge transfer from the Ag site to the Pd site in accordance with electronegativity predictions. This result is consistent with the result of ...

1996-08-01

236

Solids distribution in tall tanks  

British Library Electronic Table of Contents (United Kingdom)

Abstract Uniformly distributing slurry solids in -tall- (-2:1 aspect ratio) process vessels is a significant challenge in the chemical industry. This work determined the performance of various multi-tier agitation systems in uniformly distributing a settling solid throughout water in a -tall- laboratory vessel. It used a 0.445-m ID Plexiglas tank, with a slurry height of 0.889-m, to determine how solids distribution changes with solids loading (wt.%), impeller speed, and impeller type. Some impeller types uniformly distributed the solids even before energy input exceeded 1.00-W/kg. Significantly higher energy improved solids distribution little because flow within the vessel eventually became choked.

2011-01-01

237

{Beta} decay and isomeric properties of neutron-rich Ca and Sc isotopes.  

Energy Technology Data Exchange (ETDEWEB)

The isomeric and {beta}-decay properties of neutron-rich {sup 53-57}Sc and {sup 53,54}Ca nuclei near neutron number N = 32 are reported, and the low-energy level schemes of {sup 53,54,56}Sc and {sup 53-57}Ti are presented. The low-energy level structures of the {sub 21}Sc isotopes are discussed in terms of the coupling of the valence 1f{sub 7/2} proton to states in the corresponding {sub 20}Ca cores. Implications with respect to the robustness of the N = 32 subshell closure are discussed, as well as the repercussions for a possible N = 34 subshell closure.

2010-07-21

238

Production of cumulative hadrons in quark models of flucton fragmentation  

Energy Technology Data Exchange (ETDEWEB)

Quark models of production of cumulative particles and the EMC effect are analyzed. It is shown that all these models are characterized by a universal relation between the spectrum of cumulative nucleons and the cross section for cumulative particles containing valence quarks of the nucleus. This relation is tested for the deuteron, and the role of secondary nuclear processes for heavy nuclei is discussed. It is noted that the ''sea'' cumulative particles (K/sup -/, p-bar) are particularly important for understanding the nature of the difference between the structure functions of a nucleus and of a free nucleon.

1988-05-01

239

Preparation of silver nanofluid by the submerged arc nanoparticle synthesis system (SANSS)  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this study is fabrication and characterization of silver nanofluid by the submerged arc nanoparticle synthesis system (SANSS). The silver metal electrodes under the electrical discharge will melt and evaporate rapidly and condense to form the nanoparticles in the lower temperature dielectric liquid and produce the suspended nanoparticle. The results showed that the spherical nanosilver particle formed in the ethylene glycol and the mean particle size is about 12.5 nm. The prepared silver nanofluid was irradiated under the 410 nm visible light, electrons could be excited from the valence band to the conduction band. The silver nanofluid more closely resembles Newtonian fluids.

2007-05-31

240

Physics with Polarized Antiprotons  

Energy Technology Data Exchange (ETDEWEB)

Polarized antiprotons produced by spin filtering with an internal polarized gas target provide access to a wealth of single- and double-spin observables, thereby opening a window to physics uniquely accessible with the HESR at FAIR. This includes a first measurement of the transversity distribution of the valence quarks in the proton, and a first measurement of the moduli and the relative phase of the time-like electric and magnetic form factors G{sub E,M} of the proton. In polarized and unpolarized pp-bar elastic scattering open questions like the contribution from the odd charge-symmetry Landshoff-mechanism at large |t| and spin-effects in the extraction of the forward scattering amplitude at low |t| can be addressed.

2006-04-15

241

Optical spectra and electronic structure of actinide ions in compounds and in solution  

International Nuclear Information System (INIS)

This report provides a summary of theoretical and experimental studies of actinide spectra in condensed phases. Much of the work was accomplished at Argonne National Laboratory, but references to related investigations by others are included. Spectroscopic studies of the trivlent actinides are emphasized, as is the use of energy level parameters, evaluated from experimental data, to investigate systematic trends in electronic structure and other properties. Some reference is made to correlations with atomic spectra, as well as with spectra of the (II), (IV), and higher valence states. 207 refs., 39 figs., 38 tabs.

1985-01-01

242

Electronic structure of one-to-one and defect scandium sulfide  

Energy Technology Data Exchange (ETDEWEB)

Self-consistent electronic structure calculations have been performed on two compositions of scandium sulfide ScS and Sc/sub 3/S/sub 4/. The results of the calculation of ScS are similar to those obtained for other transition metal chalcogenides and are in excellent agreement with heat capacity and reflectance measurements as well as UPS experiments. The calculation of the defect structure indicates the creation of sulfur p nonbonding states in metal-deficient ScS. The valency of the metal ions remains unchanged upon the creation of vacancies.

1984-03-01

243

Distribution amplitudes of {sigma} and {lambda} and their electromagnetic form factors  

Energy Technology Data Exchange (ETDEWEB)

Based on QCD conformal partial wave expansion to leading order conformal spin accuracy, we present the light-cone distribution amplitudes (DAs) of {sigma} and {lambda} baryons up to twist 6. It is concluded that fourteen independent DAs are needed to describe the valence three-quark states of the baryons at small transverse separations. The nonperturbative parameters relevant to the DAs are determined within the framework of QCD sum rule method. With the obtained DAs, a simple investigation on the electromagnetic form factors of these baryons are given. The magnetic moments of the baryons are estimated by fitting the magnetic form factor with the dipole formula.

2009-04-15

244

Chiral solitons in nuclei: Electromagnetic form factors  

Science.gov (United States)

We calculate the electromagnetic form factors of a bound proton. The chiral quark-soliton model provides the quark and antiquark substructure of the proton, which is embedded in nuclear matter. This procedure yields significant modifications of the form factors in the nuclear environment. The sea quarks are almost completely unaffected, and serve to mitigate the valence quark effect. In particular, the ratio of the isoscalar electric to the isovector magnetic form factor decreases by 20% at Q{sup 2}=1 GeV{sup 2} at nuclear density, and we do not see a strong enhancement of the magnetic moment.

2004-12-01

245

Chemical effects of L X-ray intensity ratios in niobium and molybdenum compounds  

Energy Technology Data Exchange (ETDEWEB)

Chemical effects of L X-ray intensity ratios in niobium and molybdenum compounds were studied by electron and proton bombardments. L{sub {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{sub {gamma}1}/L{sub {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.).

1990-12-20

246

Chemical effects of L X-ray intensity ratios in niobium and molybdenum compounds  

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.).

1990-12-01

247

? decay and isomeric properties of neutron-rich Ca and Sc isotopes  

International Nuclear Information System (INIS)

The isomeric and ?-decay properties of neutron-rich 53-57Sc and 53,54Ca nuclei near neutron number N=32 are reported, and the low-energy level schemes of 53,54,56Sc and 53-57Ti are presented. The low-energy level structures of the 21Sc isotopes are discussed in terms of the coupling of the valence 1f7/2 proton to states in the corresponding 20Ca cores. Implications with respect to the robustness of the N=32 subshell closure are discussed, as well as the repercussions for a possible N=34 subshell closure.

2010-07-01

248

K#beta#-to-K#alpha# x-ray intensity ratio studies of the valence electronic structure of Fe and Ni in Fe_xNi_1_-_x alloys  

International Nuclear Information System (INIS)

K#beta#-to-K#alpha# x-ray intensity ratios of Fe and Ni in pure metals and in Fe_xNi_1_-_x alloys (x=0.20, 0.50, 0.58) exhibiting similar crystalline structure have been measured following excitation by 59.54 keV #gamma# rays from a 200 mCi "2"4"1Am point source to understand why the properties of the Fe_xNi_1_-_x (x=0.2) alloy are distinct from other alloy compositions. The valence electronic structure of Fe and Ni in the samples has been evaluated by comparing the measured K#beta#-to-K#alpha# intensity ratios with the results of multiconfiguration Dirac-Fock calculations. Significant changes in the 3d electron population (with respect to the pure metal) are observed for Fe and Ni for certain alloy compositions. These changes can be explained by assuming rearrangement of electrons between 3d and (4s,4p) band states of the individual metal atoms. It has been found that the valence electronic structure of the Fe_0_._2Ni_0_._8 alloy is totally ...

2001-02-15

249

Electronic structure of KTiOAsO_4: A comparative study by the full potential linearized augmented plane wave method, X-ray emission spectroscopy and X-ray photoelectron spectroscopy  

International Nuclear Information System (INIS)

First-principles self-consistent band-structure calculations of potassium titanyl arsenate, KTiOAsO_4 (KTA), have been made using the full potential linearized augmented plane wave (FP-LAPW) method. Total and partial densities of states of the constituent atoms of KTA have been derived. The results obtained show that the valence band of KTA is dominated by contributions of the O 2p-like states, while the Ti 3d-like states are the main contributors into the conduction band of the compound. Additionally, the FP-LAPW calculations have revealed that potassium atoms are highly ionized in KTA. In the present work, the X-ray emission spectroscopy (XES) and X-ray photoelectron spectroscopy (XPS) methods were also employed to investigate experimentally the electronic structure of potassium titanyl arsenate. For the mentioned compound, the XES K Ll, Ti L#alpha#, As K#beta#_2 and O K#alpha# bands reflecting the valence K s-, Ti s,d-, As p- and O p-like ...

2009-05-27

250

Donnan dialysis with ion-exchange membranes. 3: Diffusion coefficients using ions of different valence  

Energy Technology Data Exchange (ETDEWEB)

Donnan dialysis with ion-exchange membranes was studied under various kinds of experimental conditions using ions of different valences. The diffusion coefficients (D{sub d}) of various kinds of ions in the ion-exchange membrane were obtained by curve fitting an equation derived from the mass balance to three kinds of Donnan dialytic experiments. It was found that the value of D{sub d}/D{sub s} using D{sub d} of monovalent ions in Donnan dialysis with a set of monovalent feed ions and bivalent driving ions was 1/175, where D{sub s} represents a diffusion coefficient in solution. D{sub s} was calculated from the Nernst-Einstein equation substituted by the ionic conductance of ions at infinite dilution in water. Using D{sub d} of bivalent ions in Donnan dialysis with the same set led to a D{sub d}/D{sub s} value of 1/438. Moreover, using D{sub d} in Donnan dialysis with the same set, the value of D{sub d}/D{sub e} was kept constant at 0.4 (D{sub e} expresses the ...

1999-01-01

251

Solid state alkali metal-halogen cell  

Energy Technology Data Exchange (ETDEWEB)

A solid electrolyte cell comprises an alkali metal anode, e.g. lithium, a halogen-containing organic polymer cathode and a solid elecrolyte between the anode and the cathode. The cathode comprises iodine-containing vacuum-cyclised polyacrylonitrile, and the solid electrolyte is preferably lithium iodide and halogen-free vacuum-cyclised polyacrylonitrile. This patent also discloses the use of isotactic polyacrylonitrile, a method of making a cathode comprising iodine-containing vacuum-cyclised polyacrylonitrile, and novel methods of making the solid elecrolyte cells described.

1988-04-26

252

Anaerobic digestion of municipal solid waste: Technical developments  

Energy Technology Data Exchange (ETDEWEB)

The anaerobic biogasification of organic wastes generates two useful products: a medium-Btu fuel gas and a compost-quality organic residue. Although commercial-scale digestion systems are used to treat municipal sewage wastes, the disposal of solid organic wastes, including municipal solid wastes (MSW), requires a more cost-efficient process. Modern biogasification systems employ high-rate, high-solids fermentation methods to improve process efficiency and reduce capital costs. The design criteria and development stages are discussed. These systems are also compared with conventional low-solids fermentation technology.

1996-01-01

253

The prairie vole: an emerging model organism for understanding the social brain  

UK PubMed Central (United Kingdom)

Unlike most mammalian species, the prairie vole is highly affiliative, forms enduring social bonds between mates, and displays biparental behavior. Over two decades of research in this species...Full Text Available

2010-02-01

254

The neurobiology of social attachment: A comparative approach to behavioral, neuroanatomical, and neurochemical studies*  

UK PubMed Central (United Kingdom)

The formation and maintenance of social bonds in adulthood is an essential component of human health. However studies investigating the underlying neurobiology of such behaviors have been scarce....Full Text Available

2008-11-01

255

The Effect of Recasting on Bond Strength between Porcelain and Base-Metal Alloys  

British Library Electronic Table of Contents (United Kingdom)

Abstract Purpose: Long-term success of metal ceramic restorations depends on metal ceramic bond strength. The purpose of this study was to determine whether recasting of base-metal alloys has any effect on metal ceramic bond strength. Materials and Methods: Super Cast and Verabond base-metal alloys were used to cast 260 wax patterns. The alloy specimens were equally divided into five groups and cast as: group A 0.0%, B 25%, C 50%, D 75%, and E 100% once-cast alloy. Each group was divided into two subgroups: the first group was cast with Super Cast and the second with Verabond. In each subgroup half of the cast alloys were veneered with Vita VMK 68 and the others with Ceramco 3. Results: Recasting decreased bond strength (p < 0.006) when used for 50% once-cast alloy. Group E with 100% new S...

2011-01-01

256

RADC RELIABILITY PHYSICS NOTEBOOK  

Science.gov (United States)

... 2-37 2.3.1.5.4 Imperfect Bonding of Die ..... 2-37 2.3.1.5.5 "Purple Plague" .... 2-37 2.3.1.5.6 Tool Damage ..... 2-37 ...

1965-10-01

257

Planning and interpreting cement bond logs; Implementation of an expert system  

Energy Technology Data Exchange (ETDEWEB)

The Cement Bond Log Advisor is an expert system being developed to assist users in the design, evaluation, and interpretation of cement bond logs (CBL's). CBL's are produced by sonic tools run after the casing is cemented in a well to determine how well the cement is bonded to the casing and formation and whether a cement squeeze jog should be attempted. During the development of program, two particular challenges were encountered and resolved in ways that might be of general interest to developers of expert system applications for the petroleum industry. The first challenge was to find an efficient and effective method for guiding the user in correlating and interpreting the relationships between multiple sources of continuous visual data (the various waveforms making up the log output). Second, the nomographs, which correlate log amplitudes with cement compressive strength and are used in the log ...

1991-07-01

258

Long-lived quantum coherence in photosynthetic complexes at physiological temperature  

UK PubMed Central (United Kingdom)

Photosynthetic antenna complexes capture and concentrate solar radiation by transferring the excitation to the reaction center that stores energy from the photon in chemical bonds. This process occurs...Full Text Available

2010-07-20

259

Functional properties of membrane cofactor protein of complement.  

UK PubMed Central (United Kingdom)

Membrane cofactor protein (MCP or gp45-70) of the complement system is a cofactor for factor I-mediated cleavage of fluid-phase C3b and C3b-like C3, which opens the thioester bond. In the present study...Full Text Available

1989-12-01

260

Force-dependent chemical kinetics of disulfide bond reduction observed with single-molecule techniques  

UK PubMed Central (United Kingdom)

The mechanism by which mechanical force regulates the kinetics of a chemical reaction is unknown. Here, we use single-molecule force–clamp spectroscopy and protein engineering to study the effect...Full Text Available

2006-05-09

261

Enhanced tube inner surface heat transfer device and method  

Science.gov (United States)

An inner surface substrate of metal tubes is provided with a single layer of randomly distributed metal bodies bonded to the substrate, spaced from each other, and substantially surrounded by the substrate to form body void space.

1979-05-15

262

Disulfide Bonds and the Quaternary Structure of Factor VIII/von Willebrand Factor  

UK PubMed Central (United Kingdom)

Human Factor VIII/von Willebrand factor, purified by calcium citrate-cellulose chromatography and 4% agarose gel filtration was subjected to sodium dodecyl sulfate gel electrophoresis on gels containing...Full Text Available

1978-09-01

263

CRF receptors in the nucleus accumbens modulate partner preference in prairie voles  

UK PubMed Central (United Kingdom)

Recent evidence suggests a role for corticotropin-releasing factor (CRF) in the regulation of pair bonding in prairie voles. We have previously shown that monogamous and non-monogamous vole...Full Text Available

2007-04-01

264

Adhesion of DOPA-Functionalized Model Membranes to Hard and Soft Surfaces  

UK PubMed Central (United Kingdom)

The adhesive proteins secreted by marine mussels form a natural glue that cures rapidly to form strong and durable bonds in aqueous environments. These mussel adhesive proteins contain an unusual...Full Text Available

2009-01-01

265

The behavior of bonded doubler splices for composite sandwich panels  

Science.gov (United States)

The results of an investigation into the behavior of adhesively bonded doubler splices of two composite material sandwich panels are presented. The splices are studied from three approaches: analytical; numerical (finite elements); and experimental. Several parameters that characterize the splice are developed to determine their influence upon joint strength. These parameters are: doubler overlap length; core stiffness; laminate bending stiffness; the size of the gap between the spliced sandwich panels; and room and elevated temperatures. Similarities and contrasts between these splices and the physically similar single and double lap joints are discussed. The results of this investigation suggest several possible approaches to improving the strength of the sandwich splices.

1980-07-01

266

Studies relevant to the catalytic activation of carbon monoxide. Technical progress report, September 1991  

Energy Technology Data Exchange (ETDEWEB)

Research activity during the 1991--1992 funding period has been concerned with the following topics relevant to carbon monoxide activation. (1) Exploratory studies of water gas shift catalysts heterogenized on polystyrene based polymers. (2) Mechanistic investigation of the nucleophilic activation of CO in metal carbonyl clusters. (3) Application of fast reaction techniques to prepare and to investigate reactive organometallic intermediates relevant to the activation of hydrocarbons toward carbonylation and to the formation of carbon-carbon bonds via the migratory insertion of CO into metal alkyl bonds.

1992-06-04

267

Studies relevant to the catalytic activation of carbon monoxide  

Energy Technology Data Exchange (ETDEWEB)

Research activity during the 1991--1992 funding period has been concerned with the following topics relevant to carbon monoxide activation. (1) Exploratory studies of water gas shift catalysts heterogenized on polystyrene based polymers. (2) Mechanistic investigation of the nucleophilic activation of CO in metal carbonyl clusters. (3) Application of fast reaction techniques to prepare and to investigate reactive organometallic intermediates relevant to the activation of hydrocarbons toward carbonylation and to the formation of carbon-carbon bonds via the migratory insertion of CO into metal alkyl bonds.

1992-06-04

268

Structural bonding-breakage constitutive model for natural unsaturated clayey soils  

British Library Electronic Table of Contents (United Kingdom)

The natural clayey soils are usually structural and unsaturated, which makes their mechanical properties quite different from the remolded saturated soils. A structural constitutive model is proposed to simulate the bonding-breakage micro-mechanism. In this model, the unsaturated soil element is divided into a cementation element and a friction element according to the binary medium theory, and the stress-strain coordination for these two elements is obtained. The cementation element is regarded as elastic, whereas the friction element is regarded as elastoplastic which can be described with the Gallipoli?s model. The theoretical formulation is verified with the comparative experiments of isotropic compressions on the saturated and unsaturated structural soils. Parametric analyses of the e...

2010-01-01

269

Radio-frequency and microwave load comprising a carbon-bonded carbon fiber composite  

Energy Technology Data Exchange (ETDEWEB)

A billet of low-density carbon-bonded carbon fiber (CBCF) composite is machined into a desired attenuator or load element shape (usually tapering). The CBCF composite is used as a free-standing load element or, preferably, brazed to the copper, brass or aluminum components of coaxial transmission lines or microwave waveguides. A novel braze method was developed for the brazing step. The resulting attenuator and/or load devices are robust, relatively inexpensive, more easily fabricated, and have improved performance over conventional graded-coating loads.

1998-01-01

270

On the catalytic gas phase oxidation of butadiene to furan  

Energy Technology Data Exchange (ETDEWEB)

Applying the thermochemical selectivity criterion of Hadnett et al. It is shown that the selectivity of the furan formation is not limited by a too low strength of the C-H bonds in furan when compared with the C-H bond dissociation energy in the educt molecule butadiene. In the oxidation of butadiene on a CsH{sub 2}PMo{sub 12}O{sub 40} catalyst a maximum yield of 22 mol% furan has been obtained. To improve this comparatively low furan yield oxidation activity of the catalyst must be lowered to prevent the consecutive reaction to maleic anhydride. (orig.)

1998-12-31

271

Electrocatalytic and hydridic theory for hydrogen electrode reactions and prediction of synergetic catalysts in the light of Fermi dynamics and structural bonding factors  

Energy Technology Data Exchange (ETDEWEB)

The Balandin type volcano plots have been considered for the main criterion both in catalysis and electrocatalysis to estimate their fundamental properties and optimal activity: ({alpha}) The ones, when some physical feature or catalytic activity itself is plotted usually along transition series, and ({beta}) The others, when catalytic activity arises as a function of some energetic property, the most usually of the adsorption enthalpy of intermediates bonding upon the substrate in the rate determining step (rds). 29 refs.

1998-07-01

272

Cleavable surfactants  

British Library Electronic Table of Contents (United Kingdom)

The review covers the development within the field of cleavable surfactants since 2003. Cleavable surfactants are amphiphiles in which a weak linkage has been deliberately inserted, normally, but not always, between the hydrophobic tail and the polar headgroup. Alkali labile linkages that have been used for the purpose include normal ester bonds, betaine esters, and carbonates. Ketals and ortho esters are example of bonds that are susceptible to acid hydrolysis. Several investigations deal with cationic ester-containing surfactants, both monomeric and dimeric species, the latter being gemini surfactants. Ester, amide and carbonate containing surfactants have been investigated with respect to enzyme catalyzed hydrolysis. The main incentive for the development of novel cleavable surfactants ...

2007-01-01

273

Analysis of potential self-guarantee tests for demonstrating financial assurance by non-profit colleges, universities, and hospitals and by business firms that do not issue bonds  

Energy Technology Data Exchange (ETDEWEB)

The Nuclear Regulatory Commission (NRC) on December 29, 1993, promulgated self-guarantee requirements that materials licensees may use to demonstrate financial assurance for decommissioning costs. However, nonprofit colleges and universities, nonprofit hospitals, and for-profit firms that do not issue bonds are currently precluded, by their unique accounting and financial reporting systems, or by other features of their business practices, from using the financial tests for self-guarantors adopted by the NRC. This Report evaluates several alternative financial tests that might serve as the basis for self-guarantee by these three categories of licensees.

1997-06-01

274

A new empirical potential function and its application to hydrogen bonding  

International Nuclear Information System (INIS)

A new potential function based on spectroscopic results for diatomic molecules is presented and applied to the hydrogen bonding systems. The potential energy of interaction is supposed to have electrostatic, polarization, dispersion, repulsion and effective charge-transfer contributions. Estimates of the effective charge-transfer quantity have been made based on the average charge of the proton donor and the acceptor atoms. For dimers such as water, methanol, acetic acid and formic acid, the vibrational stretching frequencies and dimerization energies are calculated and discussed in connection with Badger-Bauer rule. (author).

1981-01-01

275

The effects of a hydrogen pair in the electronic structure of the FCC iron containing a vacancy  

Energy Technology Data Exchange (ETDEWEB)

Fuel cell vehicles have been identified as the personal transportation technology of the future because of their high efficiency and very low emissions. To achieve the goal of road-ready fuel cell vehicles, great strides must be made in the development of fuel cells, hydrogen production and hydrogen storage technologies, that includes metal-H interaction studies and safety considerations. The interaction between two-hydrogen atoms and a {gamma}-Fe structure containing a vacancy has been studied using a cluster model and a theoretical method. For the study of the sequential absorption, the hydrogen atoms were positioned in their energy minima configurations, near the vacancy. The interactions mainly involve Fe 4s-H 1s atomic orbitals. The contribution of Fe 4p and Fe 3d orbitals is much less important. The Fe-Fe bond is weakened as new Fe-H-H and H-H pairs were formed. The effect of H atoms is limited to its first Fe neighbors. The Fe-Fe bond ...

2010-06-15

276

Two-Phase Stefan Problem with Interfacial Energy and Entropy.  

Science.gov (United States)

The classical Stefan theory for the melting of a solid or the freezing of a liquid is too simplistic to describe phenomena such as supercooling, in which a liquid supports temperatures below its freezing point, or superheating, the analog for solids, or d...

1985-01-01

277

Towards the solid-state rechargeable battery  

Energy Technology Data Exchange (ETDEWEB)

The Anglo-Danish programme of research on materials for advanced vehicular transport and other storage batteries is about to enter its fifth year. Here, the results of the work to date on solid electrolytes, electrode materials and cell design are reviewed and discussed as a systematic programme of cell testing gets underway.

1981-12-11

278

Solid-state 13C NMR spectroscopy of a 13C carbonyl-labeled polypeptide  

UK PubMed Central (United Kingdom)

High resolution structural elucidation of macromolecular structure by solid-state nuclear magnetic resonance requires the preparation of uniformly aligned samples that are isotopically labeled. In...Full Text Available

1992-06-01

279

Simulation of solid molecular hydrogen - a new twist to an old problem  

British Library Electronic Table of Contents (United Kingdom)

Solid molecular orthohydrogen exhibits orientational order at low temperatures. The orthohydrogen molecules, which are quadrupoles, order in the Pa3 structure. We have simulated this ordering, and explored the behaviour under dilution by spherical parahydrogen molecules.

2010-01-01

280

Quantum computing with solids  

Energy Technology Data Exchange (ETDEWEB)

Science and technology could be revolutionized by quantum computers, but building them from solid-state devices will not be easy. Robert W Keyes of IBM's research division outlines the challenges in scaling up the technology from lab experiments to practical devices. (U.K.)

2002-08-01

281

Process Waste Assessment for inorganic solid waste and empty containers <30 gallons  

Energy Technology Data Exchange (ETDEWEB)

This Process Waste Assessment was conducted to evaluate the two largest hazardous waste streams generated on-site at Sandia National Laboratory (SNL)/California -- ``Other Inorganic Solid Waste`` and ``Empty Containers <30 Gallons.``

1993-12-01

282

Prevention of guanine modification and chain cleavage during the solid phase synthesis of oligonucleotides using phosphoramidite derivatives.  

UK PubMed Central (United Kingdom)

Phosphoramidite reagents can phosphitylate guanine bases at the O6-position during solid phase synthesis and serious chain cleavage occurs if the base phosphitylation is not eliminated before the iodine/water...Full Text Available

1986-08-26

283

Pathological differential diagnosis of solid-pseudopapillary neoplasm and endocrine tumors of the pancreas  

UK PubMed Central (United Kingdom)

AIM: To investigate differential points of solid-pseudopapillary neoplasm (SPN) of the pancreas and pancreatic endocrine tumor (PET).METHODS: Ten cases of SPN and fourteen cases of PET were studied...Full Text Available

2010-02-28

284

Observations on the use of solid-phase-coupled antibodies in the radioimmunoassay of human placental lactogen  

UK PubMed Central (United Kingdom)

A detailed comparative assessment was made of the use of solid-phase-coupled antibodies in radioimmunoassay, by using an assay for human placental lactogen as a model system. The major advantages of...Full Text Available

1974-03-01

285

Membrane protein biosensing with plasmonic nanopore arrays and pore-spanning lipid membranes  

UK PubMed Central (United Kingdom)

Integration of solid-state biosensors and lipid bilayer membranes is important for membrane protein research and drug discovery. In these sensors, it is critical that the solid-state sensing...Full Text Available

2010-01-01

286

Division of Materials Research Employment Opportunities for Program Directors--Dear Colleague Letter  

Science.gov (United States)

... materials science and engineering, condensed-matter or materials physics, solid-state or materials ... include materials theory, condensed-matter and materials physics, solid-state and materials ...

287

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

UK PubMed Central (United Kingdom)

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

2010-01-01

288

Comparative Inhibitory Effects of Antigen and Antibody in the Staphylococcal Enterotoxin Solid-Phase Radioimmunoassay System  

UK PubMed Central (United Kingdom)

A solid-phase radioimmunoassay employing 125I-labeled enterotoxins and polystyrene tubes coated with specific antibody has been developed for assaying the relative concentrations of antibodies...Full Text Available

1975-06-01

289

Clinical Strategy for the Management of Solid Pseudopapillary Tumor of the Pancreas: Aggressive or Less?  

UK PubMed Central (United Kingdom)

Objective: To further delineate the clinicopathological and radiological features of solid pseudopapillary tumor (SPT) of the pancreas and summarize the surgical therapy strategy for this tumor. Methods:...Full Text Available

290

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

UK PubMed Central (United Kingdom)

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

2008-02-14

291

Transport effect on He II film under conditions of weak interaction with the substrate  

Energy Technology Data Exchange (ETDEWEB)

The properties of a helium film on the surface of solid parahydrogen are investigated. It is shown that wetting of the solid hydrogen by the liquid helium occurs. The transport velocities along the He II film on the solid parahydrogen surface are measured in broad temperature, film height, and level difference ranges. It is shown that the transport velocity in this case has the least value as compared with its value on other substrates. The thickness of the helium-saturated film is determined on the solid hydrogen surface on the basis of the data obtained, and the value is in good agreement with the results of a computation performed within the framework of the Frenkel' theory.

1980-10-01

292

Thermal performance and design of a solid particle cavity receiver  

Energy Technology Data Exchange (ETDEWEB)

A model for energy transport in a solid particle cavity receiver is developed and applied to the design and analysis of a receiver for the Central Receiver Test Facility (CRTF), Albuquerque, New Mexico. The model gives thermal performance results - including particle temperatures, cavity efficiencies, and wall temperatures - which directly affect the economic and technical feasibility of a solid particle receiver. In addition, design criteria relevant to the configuration of a solid particle cavity receiver are developed. Results for CRTF indicate that at design conditions particle temperatures will exceed 1200/sup 0/K with cavity efficiencies on the order of 75%.

1985-04-01

293

Synchrotron Probes of Emergent Electronic States of Matter in Solids  

ScienceCinema

...of this article he quotes um i am told by my english ...

294

Process for retorting oil shale and the like  

Energy Technology Data Exchange (ETDEWEB)

The production of oil by retorting shale and other hydrocarbonaceous and lignocellulosic solid materials is facilitated by retorting in the presence of steam and acetic acid.

1983-08-02

295

PowerPoint Presentation  

Wastenet

facilities, building hygienic latrines and introducing regular solid waste collection systems . These methods are constantly being developed and

296

Passivation-free solid state battery  

Energy Technology Data Exchange (ETDEWEB)

This invention pertains to passivation-free solid-state rechargeable batteries composed of Li.sub.4 Ti.sub.5 O.sub.12 anode, a solid polymer electrolyte and a high voltage cathode. The solid polymer electrolyte comprises a polymer host, such as polyacrylonitrile, poly(vinyl chloride), poly(vinyl sulfone), and poly(vinylidene fluoride), plasticized by a solution of a Li salt in an organic solvent. The high voltage cathode includes LiMn.sub.2 O.sub.4, LiCoO.sub.2, LiNiO.sub.2 and LiV.sub.2 O.sub.5 and their derivatives.

1998-01-01

297

Passivation-free solid state battery  

Energy Technology Data Exchange (ETDEWEB)

This invention pertains to passivation-free solid-state rechargeable batteries composed of Li{sub 4}Ti{sub 5}O{sub 12} anode, a solid polymer electrolyte and a high voltage cathode. The solid polymer electrolyte comprises a polymer host, such as polyacrylonitrile, poly(vinyl chloride), poly(vinyl sulfone), and poly(vinylidene fluoride), plasticized by a solution of a Li salt in an organic solvent. The high voltage cathode includes LiMn{sub 2}O{sub 4}, LiCoO{sub 2}, LiNiO{sub 2} and LiV{sub 2}O{sub 5} and their derivatives. 5 figs.

1998-06-16

298

Particle-Sizing System for Scanning Electron Microscope ...  

Science.gov (United States)

... THESIS PARTICLE-SIZING SYSTEM FOR SCANNING ELECTRON MICROSCOPE IMAGES OF SOLID-PROPELLANT COMBUSTION EXHAUST ...

1991-03-01

300

Electron Beam and Gamma Radiolysis of Solid-State Metoclopramide  

British Library Electronic Table of Contents (United Kingdom)

Purpose Study the radiolysis of solid-state metoclopramide hydrochloride at various absorbed doses. Elucidate the structure of the degradation products to gain information on the radiolysis mechanisms. Methods Solid-state metoclopramide samples were irradiated at several doses with gamma rays and high-energy electrons to evaluate the influence of the dose rate. High-performance liquid chromatography with a diode array detector was used to measure the chemical potency as a function of the absorbed dose and to quantify the degradation products. The characterization of degradation products was performed by liquid chromatography/atmospheric pressure chemical ionization/tandem mass spectrometry. Results The degradation of solid-state metoclopramide after irradiation was negligible. No qualitati...

2006-01-01

302

Autogenous electrolyte, non-pyrolytically produced solid capacitor structure  

Energy Technology Data Exchange (ETDEWEB)

A solid electrolytic capacitor having a solid electrolyte comprising manganese dioxide dispersed in an aromatic polyamide capable of further cure to form polyimide linkages, the solid electrolyte being disposed between a first electrode made of valve metal covered by an anodic oxide film and a second electrode opposite the first electrode. The electrolyte autogenously produces water, oxygen, and hydroxyl groups which act as healing substances and is not itself produced pyrolytically. Reduction of the manganese dioxide and the water molecules released by formation of imide linkages result in substantially improved self-healing of anodic dielectric layer defects.

1998-01-01

303

A NEW FORM OF SOLID STATE SOLAR GENERATOR  

Science.gov (United States)

... nent to the design and construction of metal-semiconductor solar cells, in that both the photovoltage and the efficiency of metal-semiconductor cells ...

1962-01-01

304

Spontaneous radiation emission during penetration of ions in solids  

International Nuclear Information System (INIS)

In this work, the principal continuum radiative emission processes, which occur during the penetration of ions in solids or gases, are resumed. The characteristics of the following processes are discussed: secondary electron bremsstrahlung (SEB), atomic bremsstrahlung (AB), and internuclear bremsstrahlung (INB). Recent advances of the ion channeling effects in crystal solids on the spontaneous radiative spectra are exposed. (A.C.A.S.).

1988-09-25

305

Resources | Environment Knowledge Hub  

Wastenet

... MUNICIPAL SOLID WASTES (MANAGEMENT AND HANDLING) RULES, 2000 Plastic Bag ban in Dhaka City, Bangladesh Private Sector Participation in Municipal Solid Waste Management SKAT 2000 TECHNICAL GUIDELINES ON MUNICIPAL SOLID WASTE MANAGEMENT Hazardous Waste Management Unit, Environmental Pollution Control Division, Central Environmental Authority, Sri Lanka 2004 Subregional ...

306

Pharmaceutics | Special Issue: Solid Dosage Forms  

Wastenet

...Pharmaceutics | Special Issue: Solid Dosage Forms LoginRegister mdpi.com Journals A-Z For Authors About Open Access Policy Title / Keyword Journal all Administrative Sciences Agriculture ...Establishing Differences from Adults Recent Developments and Future Perspectives in Dissolution Testing Solid Dosage Forms The 1st Electronic Conference on Pharmaceutical Science The Progress on Pharmaceutics ... 1 (2009) Special Issue \\

307

Peculiarities of #beta#-solid solution decomposition in (#alpha#+#beta#) titanium alloy at low temperature  

International Nuclear Information System (INIS)

The physical methods were used to study the decomposition of a metastable #beta#-solid solution in the VT22 two-phase titanium alloy. It is shown that the martensitic #beta# #-># #alpha#'' transformation in doped-element depleted microvolumes of the #beta#-solid solution are dominanted and the long-time multistage decomposition through a number of intermediate states in others.

308

ON THE POSSIBILITY OF ENRICHMENT AND DIFFERENTIATION IN GAS GIANTS DURING BIRTH BY DISK INSTABILITY  

International Nuclear Information System (INIS)

We investigate the coupling between rock-size solids and gas during the formation of gas giant planets by disk fragmentation in the outer regions of massive disks. In this study, we use three-dimensional radiative hydrodynamic simulations and model solids as a spatial distribution of particles. We assume that half of the total solid fraction is in small grains and half in large solids. The former are perfectly entrained with the gas and set the opacity in the disk, while the latter are allowed to respond to gas drag forces, with the back reaction on the gas taken into account. To explore the maximum effects of gas-solid interactions, we first consider 10 cm size particles. We then compare these results to a simulation with 1 km size particles, which explores the low-drag regime. We show that (1) disk instability planets have the potential to form large cores due to aerodynamic ...

2010-11-20

309

Microwave Oven for the Rapid Determination of Total Solids Content of Natural Rubber Latex  

British Library Electronic Table of Contents (United Kingdom)

The suitability of using the microwave oven for the rapid determination of total solids content (TSC) of natural rubber latex has been established over a broad range of dry rubber content (DRC). The total solids content values obtained by the microwave oven method are compared with the values obtained by heating in a conventional convection oven. Heating in a microwave oven is advantageous as the measurement time could be reduced considerably.

2008-01-01

310

Heat transfer in boiling liquified gas  

Energy Technology Data Exchange (ETDEWEB)

Means for increasing heat transfer characteristics between the surface of a solid and a boiling liquid are described in which the solid is immersed is comprised of a solid with passages which extend therethrough to the surface for the circulation of liquid through the passages for emergence from the surface to eliminate at least a portion of the unstable vapor film otherwise formed on the surface.

1980-09-23

311

GS1 - radiological protection objectives for the disposal of solid radioactive wastes  

Energy Technology Data Exchange (ETDEWEB)

A summary is given of the 1983 NRPB-GS1 Report on the 'Radiological protection objectives for the disposal of solid radioactive wastes'. The two principal difficulties in applying the ICRP system of dose limitation to some solid waste disposal methods are outlined. Despite these difficulties three radiological protection objectives for waste disposal were recommended based on the same fundamental principle as ICRP recommendations.

1984-01-01

312

Decomposition of metastable solid solution in #beta#-titanium alloy  

International Nuclear Information System (INIS)

Peculiarities of metastable #beta#-solid solution decmposition in titanium alloy VT30 in the process of isothermal ageing in the range 500-650 deg C are investigated. Using the methods of transmittion electron microscopy, X-ray diffraction analysis, etc., it is shown that in the case of alloy quenching from the temperature below the point of complete polymorphous transformation (T_t_._t_.), as well as after warm rolling the course of subsequent decomposition of solid solution can be consierably complicated.

313

Analysis of stability of semiconductor 5-component solid solutions of A"3B"5 compounds  

International Nuclear Information System (INIS)

With the use of the regular solutions model the expressions have been derived for calculation of boundaries of spinodal decomposition region as applied to five-component solid solutions of A"3B"5 compounds. The evaluation has been made of fields of stability for Al_x__1Ga_x__2In_1_-_x__1_-_x__2PyAs_1_-_y solid solution.

314

The ERICAM model: a proposal for amelioration of nuclear liability by funding on the capital markets; Das Modell ERICAM: Ein Vorschlag zur Verbesserung der Kernenergiehaftpflicht durch Einbezug von Kapitalmaerkten  

Energy Technology Data Exchange (ETDEWEB)

The ERICAM model (Environmental Risk Internalization through Capital Markets) includes the capital markets as a source contributing to the coverage of risks due to nuclear activites, thus enhancing the effectiveness and functions of the nuclear liability law. The model proposed will allow higher amounts for compensation and will increase financial security, flow of information, and efficient use of resources. The implementation of the model can be achieved on the financing side by issuing Nuke bonds, linking accident-specific options to government bonds. This will essentially increase the risk coverage compared to present means, and will be a pin-pointed addition to the existing layer system. There are three institutions proposed to act as mediators in the implementation of the model: A government authority to supervise the trade in Nuke bonds. Risk-bearing associations in oder to enhance the model`s efficiency, and to ...

1995-12-31

315

Mechanisms and controlling characteristics of the catalytic oxidation of methane. Technical progress report, June 15, 1990--December 14, 1992  

Energy Technology Data Exchange (ETDEWEB)

We have demonstrated in this work (1) that methane is readily activated at mild conditions (100{degree}C, 1 torr) over a relatively noble metal, Pd. This was observed using a stepped and kinked Pd(679) crystal (1), and other crystal faces are now being investigated to establish whether the cracking of the C-H bond of methane on Pd is structure sensitive or structure insensitive. Oxygen chemisorption is extremely structure sensitive: weakly bonded, highly reactive oxygen overlayers form on Pd(100) surface (2), while strongly bonded, moderately reactive oxygen overlayers form on Pd(111) and Pd(679). Reaction of the weakly bonded oxygen with surface carbide gives rise to CO{sub 2} over clean Pd(100) but to CO over halogen-doped Pd(100) (3--5). The effect of halogens is primarily ensemble-controlling, or oxygen-supply restricting, but long range influence of surface Cl on the strength of the Pd-O ...

1992-12-31

316

Mechanisms and controlling characteristics of the catalytic oxidation of methane  

Energy Technology Data Exchange (ETDEWEB)

We have demonstrated in this work (1) that methane is readily activated at mild conditions (100[degree]C, 1 torr) over a relatively noble metal, Pd. This was observed using a stepped and kinked Pd(679) crystal (1), and other crystal faces are now being investigated to establish whether the cracking of the C-H bond of methane on Pd is structure sensitive or structure insensitive. Oxygen chemisorption is extremely structure sensitive: weakly bonded, highly reactive oxygen overlayers form on Pd(100) surface (2), while strongly bonded, moderately reactive oxygen overlayers form on Pd(111) and Pd(679). Reaction of the weakly bonded oxygen with surface carbide gives rise to CO[sub 2] over clean Pd(100) but to CO over halogen-doped Pd(100) (3--5). The effect of halogens is primarily ensemble-controlling, or oxygen-supply restricting, but long range influence of surface Cl on the strength of the Pd-O ...

1992-01-01

317

Development of MHD generator channel walls, 1  

International Nuclear Information System (INIS)

Experimental results of compatibility tests on ceramics-metal bonded structures performed under high heat flux conditions in splash test apparatus are reported. Emphasis is placed on results of the channel wall design and its critical operating conditions under MHD environment. The module design of one cold type and three semihot type insulators have been tested. These materials were Al_2O_3, Al_2MgO_4, LaAlO_4, MgO and Sialon ceramics. The methods of cold type ceramics-metal bonding structure were studied on Al_2O_3 and Spinel spray coating technology. The refractory metallizing and ceramics-metal graded structure manufactured by HIP technologies were applied to bonding between the MgO or LaAlO_4 and metallic cooling system. The Sialon non-bonding structure was tested with mechanical supported cooling system by shrinc fitting method. The results indicated that the bonding ...

318

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

Energy Technology Data Exchange (ETDEWEB)

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

1996-04-01

319

Thermoluminescence of irradiated RbCl and RbCl:Sn crystals  

International Nuclear Information System (INIS)

The thermoluminescence (TL) and emission of coloured RbCl and RbCl:Sn crystals are studied in the temperature range 300 to 560 K. The glow peaks responsible for F centres and tin centres in different valence states are identified using optical bleaching studies. The glow peaks are analysed using total curve fitting method and the kinetic parameters are determined. In moderately #gamma#-irradiated tin-doped RbCl crystals, the TL emission bands observed at 4.0, 3.6, and 2.2 eV are attributed to Sn"0, Sn"+, and Sn"- centers, respectively. A comprehensive energy level diagram depicting the various TL processes in these undoped and tin-doped RbCl crystals is proposed. (author).

320

Superconducting-like behaviour of the layered Chalcogenides CuS and CuSe below 40 K  

British Library Electronic Table of Contents (United Kingdom)

The investigation of strongly sintered ''quasi molten'' CuS and CuSe chalcogenides shows that they exhibit a sharp diamagnetic transition and a resistivity drop around 40 K. The reminiscence of such high temperature superconductivity features, never observed to date for these phases, is strongly supported by two chemical characteristics: bidimensionality of the structure and mixed valency of copper. The absence of zero resistance suggests that the internal chemical pressure in the samples has a key role in the existence of superconductivity: the S-S or Se-Se interlayer distances are very sensitive to the pressure, so that the critical distance for the percolation can be reached in the core of the samples, but not at the vicinity of the surface, where relaxation may appear.

2011-01-01

321

Spin-dependent potentials in the linearized collective Schroedinger equation for nuclear quadrupole vibrations  

Energy Technology Data Exchange (ETDEWEB)

The linearized collective Schroedinger equation for nuclear quadrupole surface vibrations incorporates a new spin degree of freeedom with a spin value of 3/2. We use this equation to describe the low energy spectrum of certain even-odd Ir nuclei which have a spin 3/2 in their ground state. For that purpose we explicitly introduce collective spin-dependent potentials which simulate the interaction of the valence nucleon with the core. The linearized Schroedinger equation is transformed into an effective Schroedinger equation with collective spin-dependent potentials. Already collective spin-orbit couplings of SO(3) and SO(5) type are sufficient to reproduce the lowest excited states of even-odd Ir nuclei. (orig.).

1990-06-01

322

Spin-dependent potentials in the linearized collective Schroedinger equation for nuclear quadrupole vibrations  

International Nuclear Information System (INIS)

The linearized collective Schroedinger equation for nuclear quadrupole surface vibrations incorporates a new spin degree of freeedom with a spin value of 3/2. We use this equation to describe the low energy spectrum of certain even-odd Ir nuclei which have a spin 3/2 in their ground state. For that purpose we explicitly introduce collective spin-dependent potentials which simulate the interaction of the valence nucleon with the core. The linearized Schroedinger equation is transformed into an effective Schroedinger equation with collective spin-dependent potentials. Already collective spin-orbit couplings of SO(3) and SO(5) type are sufficient to reproduce the lowest excited states of even-odd Ir nuclei. (orig.).

323

Spectroscopy of neutron-rich {sup 59-63}Mn isotopes  

Science.gov (United States)

The neutron-rich Mn isotopes from A=59 to 63 have been studied through multi-nucleon transfer reactions by bombarding a {sup 238}U target with a beam of {sup 70}Zn at an energy of E{sub lab}=460 MeV. Prompt {gamma} rays measured by the CLARA array have been identified unambiguously for each nucleus, using coincidence relationships with ions detected in the high-acceptance magnetic spectrometer PRISMA. The new data extends the knowledge of the low-lying level structure of Mn isotopes, which is discussed in terms of the systematics of the region. Results are compared with large-scale shell-model calculations using different effective interactions and valence spaces.

2008-08-15

324

Spectroscopy of neutron-rich "5"9"-"6"3Mn isotopes  

International Nuclear Information System (INIS)

The neutron-rich Mn isotopes from A=59 to 63 have been studied through multi-nucleon transfer reactions by bombarding a "2"3"8U target with a beam of "7"0Zn at an energy of E_l_a_b=460 MeV. Prompt #gamma# rays measured by the CLARA array have been identified unambiguously for each nucleus, using coincidence relationships with ions detected in the high-acceptance magnetic spectrometer PRISMA. The new data extends the knowledge of the low-lying level structure of Mn isotopes, which is discussed in terms of the systematics of the region. Results are compared with large-scale shell-model calculations using different effective interactions and valence spaces.

2008-08-01

325

Simplified electrostatic model for band-gap underestimates in the local-density approximation  

Science.gov (United States)

An estimate of the undercounted electrostatic energy terms in local-density-functional total-energy calculations for nonmetallic systems with separated electron-hole pairs is used to derive a simplified correction to density-functional - theory band gaps. The correction is evaluated for Ne, Ar, Kr, LiF, NaCl, CsCl, MgO, CaS, BaS, C, AlP, and Si. The band-gap errors are reduced from 40-50% to 10-15% for most of the systems studied. Conduction-band corrections are shown to be nearly as large as valence-band corrections in free-electron-like semiconductors. 28 references, 1 figure.

1985-04-15

326

Quantum-chemical investigation of mechanism of dehydroxylation of crystalline and amorphous aluminosilicates  

Science.gov (United States)

Within the framework of the cluster approach and the semiempirical SCF MO LCAO method in the CNDO/BW valence approximation, possible pathways have been compared for the dehydroxylation of aluminosilicate systems. It has been shown that dehydroxylation as a result of splitting of a water molecule from an acidic bridge hydroxyl group and a more basic terminal group Al-OH is the most energyfavorable. Apparently, such a dehydroxylation pathway is primarily characteristic for amorphous aluminosilicates. Typical of crystalline aluminosilicates at moderate heat-treating temperature is dehydroxylation through splitting of a water molecule from an acidic bridge hydroxyl group and a neutral Si-OH group; at higher temperatures, there is a possible pathway of dehydroxylation of highsilica zeolites as a result of condensation of two acidic surface hydroxyls.

1986-07-01

327

Polarized neutron diffraction study of CePd{sub 3}  

Energy Technology Data Exchange (ETDEWEB)

We have performed polarized neutron diffraction measurements on the intermediate valence compound CePd{sub 3} using the D3 spectrometer at the ILL. The results show that at low temperatures, 1.7 K, as well as at 100 K, the field-induced magnetic amplitudes measured in a field of 4.6 T could be interpreted in terms of two contributions: a 4f-type contribution with a Ce{sup 3+} form factor, and an extra delocalized contribution (relatively narrow in q-extent). In particular, we find that the values of the 4f moment deduced from the extrapolation of the neutron data to Q=0 are systematically lower than the values deduced from bulk magnetization measurements performed on the same sample. This difference can be ascribed to a possible positive polarization of the conduction band which is similar at both temperatures.

2004-07-15

328

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

International Nuclear Information System (INIS)

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

1984-03-01

329

Lithium isotope separation by cryptand (2 sub(B), 2, 1) polymer  

Energy Technology Data Exchange (ETDEWEB)

Single stage separation factors ..cap alpha.. have been determined for /sup 6/Li and /sup 7/Li between lithium ions in methanol and complexed ions with a cryptand (2 sub(B), 2, 1) polymer. The /sup 6/Li was concentrated in the cryptand. The separation factors were compared with the values of other chemical exchange systems. The maximum enrichment factor obtained was epsilon = 0.047 +- 0.002. The figure is one of the greatest in the chemical exchange reactions without valence change and almost 10 times larger than the values of ion exchangers. The variation in ..cap alpha.. depending on the chemical species was small in the non-aqueous system. High enrichment of lithium isotopes was expected to be achievable by means of the chromatographic application of the cryptand (2 sub(B), 2, 1).

1984-02-01

330

J/Psi dissociation in parity-odd bubbles  

CERN Document Server

We calculate the quarkonium dissociation rate in the P and CP-odd domains (bubbles) that were possibly created in heavy-ion collisions. In the presence of the magnetic field produced by the valence quarks of colliding ions, parity-odd domains generate electric field. Quarkonium dissociation is the result of quantum tunneling of quark or antiquark through the potential barrier in this electric field. The strength of the electric field in the quarkonium comoving frame depends on the quarkonium velocity with respect to the background magnetic field. We investigate momentum, electric field strength and azimuthal dependence of the dissociation rate. Azimuthal distribution of quarkonia surviving in the electromagnetic field is strongly anisotropic; the form of anisotropy depends on the relation between the electric and magnetic fields and quarkonium momentum. These features can be used to explore the properties of the electromagnetic field created in heavy ion ...

2011-01-01

331

Electronic structure and superconductivity of europium  

International Nuclear Information System (INIS)

We have calculated the electronic structure of Eu for the bcc, hcp, and fcc crystal structures for volumes near equilibrium up to a calculated 90 GPa pressure using the augmented-plane-wave method in the local-density approximation. The frozen-core approximation was used with a semi-empirical shift of the f-states energies in the radial Schroedinger equation to move the occupied 4f valence states below the #GAMMA#_1 energy and into the core. This shift of the highly localized f-states yields the correct europium phase ordering with lattice parameters and bulk moduli in good agreement with experimental data. The calculated superconductivity properties under pressure for the bcc and hcp structures are also found to agree with and follow a T_c trend similar to recent measurement by Debessai et al.

2010-09-01

332

Competing Shapes And Alignments In Neutron-Rich Hf Nuclei  

International Nuclear Information System (INIS)

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

2008-05-12

333

Antiferromagnetic Kondo lattice: CePdSi_2  

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.).

1996-08-19

334

A first principles study on optical transparency mechanism in Dy doped #alpha#-SiAlON ceramics  

International Nuclear Information System (INIS)

Dy doped #alpha#-SiAlON ceramics prepared by the hot-pressing method show a high optical transmittance value, >70%, in the infrared region of 1.5-4.5 #mu#m. First principles calculations have been carried out to reveal the underlying transparency mechanism. It is found that the valence shell of doped Dy atoms interacts strongly with the doping states of #alpha#-SiAlON, resulting in the increase in the optical gap from 0.4 to 1.1 eV, which suppresses the photoabsorption in the wavelength region longer than 1.0 #mu#m and leads to the good transparency property. The calculated optical transmission spectra are in good agreement with the corresponding experiments.

2009-11-01

335

X-ray studies of solid n-H/sub 2/  

Energy Technology Data Exchange (ETDEWEB)

Results of X-ray investigations of solid normal hydrogen are presented. Temperature dependences of the lattice parameteps, molar volumes, linear and volume expansion coefficients in the 2K-Tsub(melt) temperature range are obtaiped. An essential n-H/sub 2/ expansion anisotropy in the premelting temperature region is pointed out. It is shown that the hexagonal lattice parameter ratios over the whole investigated temperature range is considerably higher than for solid parahydrogen. A considerable difference in thermal expansion of normal hydrogen and parahydrogen in the low temperature region is revealed. It is caused by contribuation of a rotational subsystem, increasing with the temperature decrease to crystal expansion. A detailed analysis of solid n-H/sub 2/ thermodynamic properties is conducted. The data testifying to the presence of isomorphous phase transformation in the solid n-H/sub 2/ in the ...

1983-08-01

336

Theory of NMR multiple echoes in solid hydrogen  

Energy Technology Data Exchange (ETDEWEB)

We have examined the theory of NMR multiple echoes developed for solid {sup 3}He to determine whether multiple echoes could be observed in solid hydrogen. We were particularly interested in the possibility of testing for low frequency quantum tunneling motions in solid hydrogen by the observation of multiple echoes. We find that for easily accessible nuclear spin polarizations, P > 12%, multiple echoes would be observed for HD impurities in solid parahydrogen if motional narrowing is effective in increasing the HD nuclear spin-spin relaxation time T{sub 2} to the order of 1 msec. These values for T{sub 2}, which have been observed for HD impurity concentrations of the order of 1%, are larger than the calculated rigid lattice values and can be attributed to quantum tunneling at frequencies of the order of 1kHz.

1995-11-01

337

Solid suspension in stirred tanks: UVP measurements and CFD simulations  

British Library Electronic Table of Contents (United Kingdom)

Abstract Suspension of solids in stirred reactor is widely used for catalytic reactions, dissolution, etc. Quality of solid suspension is an important parameter required for the reliable design, optimum performance, and scale up of the system. Quality of suspension depends on local characteristics of solid velocity and hold up profiles. The present work was focused on investigating quality of solid suspension using ultrasound velocity profiler (UVP) measurements and CFD simulations. The slip velocity measurements carried out with UVP were used to evaluate different drag correlations used in CFD simulations. Results discussed in this work would be useful for extending the applications of CFD models for simulating large stirred slurry reactors.

2011-01-01

338

Self-inhibited rate in gas-solid noncatalytic reactions. The shrinking core model  

Energy Technology Data Exchange (ETDEWEB)

The shrinking core model is examined for gas-solid noncatalytic reactions with a self-inhibited rate form and it is shown that multiple reaction pathways are possible for solid particles reacted under identical conditions. The observed reaction rate can have up to two discontinuities (jumps) during reaction for particles of spherical and cylindrical shape. The geometric instability analysis reveals that the reaction interface is stable under a very limited set of conditions only for solid particles of slab geometry. For a sphere or cylinder at large Biot numbers the reaction interface is always potentially unstable. This model provides a plausible explanation for gas-solid reactions which exhibit erratic shrinking core behavior.

1984-02-01

339

Quantification of order in the liquid at a solid-liquid interface by High-Resolution Transmission Electron Microscopy (HRTEM)  

Energy Technology Data Exchange (ETDEWEB)

A number of different theoretical approaches have been used to model to atomic structure and properties of solid-liquid interfaces. Most calculations indicate that ordering occurs in the first several layers of the liquid, adjacent to the crystal surface. In contrast to the numerous theoretical investigations, there have been no direct experimental observations of the atomic structure of a solid-liquid interface for comparison. Saka et al. examined solid-liquid interfaces in In and In-Sb at lattice-fringe resolution in the TEM, but their data do not reveal information about the atomic structure of the liquid phase. The purpose of this study is to determine the atomic structure of a solid-liquid interface using a highly viscous supercooled liquid, i.e., a crystal-amorphous interface.

1996-12-31

340

Partial wave expansion of ion-atom elastic scattering in solids  

International Nuclear Information System (INIS)

Elastic scattering cross sections of keV protons in solids (Z=3-82) are calculated using the partial wave expansion technique and the ''muffin-tin'' bound-atom potential. The differential cross sections for small scattering angles of less than 10deg are smaller than those with the Ziegler-Biersack-Littmark potential at all energies and for all solids, although, for larger angles, the two cross sections agree with each other. The mean free paths of the protons in the solids, obtained from the total cross sections, decrease very slowly with decreasing energy. Furthermore, at low energies they approach half the nearest-neighbor distance, which is taken as the radius of the augmented plane wave sphere in the muffin-tin model of crystalline solids. (orig.).

341

On the solid-fluid transition zone in welding analysis  

Energy Technology Data Exchange (ETDEWEB)

Equilibrium and energy equations have been developed in describing the solid-fluid transition zone during the melting and solidification of the binary alloys. Due to the existence of the transition region exhibited both solid and fluid phases at the same material point from continuum point of view, mixture theory was utilized to analyze the region. Unlike the Stefan problem, the latent heat due to the phase change appears as a source term in the heat equation. The molten fluid is treated as a thermoviscous and incompressible fluid, whereas the solid is thermoviscoplastic described by the Bodner-Partom/Walker type of constitutive equations. Thermal mechanical behaviors of the solid and the fluid phases are determined separately because of insignificant mechanical interactions between them. Volume fractions of the phases are obtained according to the equilibrium phase diagram. The simulation process of ...

1993-01-01

342

Infrared spectroscopy of rovibrational transitions of methyl radicals (CH3, CD3) in solid parahydrogen  

British Library Electronic Table of Contents (United Kingdom)

The n3 and n4 vibrational transitions of CH3 and CD3 isolated in solid parahydrogen were studied by high-resolution infrared spectroscopy. The radicals were produced by in situ UV photolysis of methyl iodides trapped in solid parahydrogen. The observed spectra showed clear rotational fine structures, which were subjected to further splitting due to the electrostatic field of solid parahydrogen. The molecular constants and crystal field parameters of the radicals in solid parahydrogen were determined by analyzing the spectral structures of the n3 and n4 transitions of CD3 by the crystal field theory. The rotational constants of the CD3 radical were found to be only a few percent smaller than those in the gas phase. The determined crystal field parameters indicated significant quantum effect...

2011-01-01

343

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

International Nuclear Information System (INIS)

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

2003-08-25

344

Role of the triple bond in acid corrosion inhibition  

Science.gov (United States)

It is now over 30 yr since the original discovery was made that acetylenic compounds are effective in inhibiting the corrosion of iron in acid media. Since then, the industrial practice of oil-well acidizing has become well-established, with key acetylenic compounds such as propargyl alcohol, hexynol, and ethyl octynol assuming increasingly important roles. New and more stable triple-bonded compounds properly formulated and synergized with nitrogen compounds are expected to be used more extensively as temperature, stability, and performance requirements increase. An evaluation is made of the structural features which enhance or limit the corrosion performance of a given acetylenic. New data involving mixtures of acetylenics, hydrogen-bonded complexes, and the use of new nitrogen synergists are covered also. Tabular data at 200/sup 0/F approximate the more strenuous conditions of an oil-well acidizing job using N-80 tubing. The performance of ...

1970-01-01

345

Reducing indoor air formaldehyde concentrations  

Energy Technology Data Exchange (ETDEWEB)

Urea-formaldehyde resin bonded particle board, medium density fiberboard and plywood paneling are used as flooring, wall paneling, for cabinet work and in furniture, and are present in almost every office, home and public building. If large quantities of these products are used in poorly ventilated spaces, high manufacturing quality control is necessary to avoid problems of latent formaldehyde release. Indoor air formaldehyde concentrations depend on the nature of the product, the product surface to air volume (loading) factor, temperature, humidity, age and product emission rates. Standard test methods are now available for measuring product emission rates that make it possible to predict the performance of UF-bonded pressed wood materials if use conditions and environmental parameters are known. Recent modifications in adhesive and board manufacturing parameters have made it possible to reduce formaldehyde emission significantly, and ...

1985-08-01

346

Micromechanical characterization tools for highly-filled polymers  

Energy Technology Data Exchange (ETDEWEB)

We are attempting to characterize and model the micromechanical response of highly-filled polymers. In this class of materials, the continuous plastic binder used to bond the highly-filled material dominates the observed viscoelastic response. As a result, realistic lifetime analysis of these materials will require a thorough understanding of the contribution of the plastic binder. Laboratory applications of these materials include plastic bonded explosives, propellants, a variety of specialized filled organic materials for stockpile systems, and highly filled epoxy dielectric materials for the National Ignition Facility. We have explored numerous techniques to characterize the local microstructure of plastic bonded explosives. However, insufficient funding was obtained to bring these technologies to maturity, nevertheless our present tool set is significantly better than 2 years ago. We have also made some progress in ...

2000-02-16

347

Lining of magnesium alloys with foils using shot peening  

Energy Technology Data Exchange (ETDEWEB)

To improve the surface properties of magnesium alloy, a lining process using shot peening was carried out. The lining of magnesium alloy with metals such as titanium and nickel is useful in heightening the corrosion and wear properties for the components. In the shot peening experiment, the foil set on the magnesium workpiece is pelted with many shots at a high velocity. The foil is bonded to the surface of the workpiece due to plastic deformation induced by the collision of the shots. A pure aluminum foil is inserted between the hard foil and magnesium workpiece to assist the bonding. To heighten the bondability, the foil and workpiece are heated and the flow stresses of the metals are reduced. In this experiment, a centrifugal shot peening machine with an electrical heater was employed. The workpieces were commercially magnesium alloys AZ31B and AZ91D, and the foils were commercially pure aluminum, pure titanium and pure nickel. The effects ...

2003-07-01

348

IR double-resonance spectroscopy applied to the 4-aminophenol(H{sub 2}O){sub 1} cluster  

Energy Technology Data Exchange (ETDEWEB)

The IR double-resonance techniques IR/R2PI (infrared/resonant 2-photon ionization), IR/PIRI (infrared-photo-induced Rydberg ionization) and IR-photodissociation spectroscopy are valuable tools to investigate structure, vibrations, and dynamical processes of neutral and ionic hydrogen-bonded clusters containing aromatic molecules. In this paper we report on the application of the IR double-resonance techniques to determine the NH and OH stretching vibrations of 4-aminophenol and 4-aminophenol(H{sub 2}O){sub 1}, both in the neutral (S{sub 0}) and ionic (D{sub 0}) ground state. All vibrational frequencies obtained for 4-aminophenol and the cluster are compared with the values obtained from ab initio and DFT calculations. In the S{sub 0} state, a trans-linear arrangement of 4-aminophenol(H{sub 2}O){sub 1} is obtained containing an O-H. O hydrogen bond. In the D{sub 0} state an overlay of two spectra can be observed resulting from the trans-linear ...

2001-03-01

349

Carbon-bonded carbon fiber insulation for radioisotope space power systems  

Energy Technology Data Exchange (ETDEWEB)

A carbon-bonded carbon fiber (CBCF) insulation developed for a radioisotope heat source is made from chopped rayon fiber about 10..mu..m long, which is carbonized and bonded with phenolic resin particles. The CBCF is an excellent lightweight insulating material with a nominal density of 0.2 Mg/m/sup 3/ and a thermal conductivity of 0.24 W/(m-K) in vacuum at 2000/sup 0/C. (Several attributes that make CBCF particularly suitable for the heat source application have been identified.) These include light weight, low thermal conductivity, chemical compatibility, and hightemperature capabilities. The mechanical strength of CBCF insulation is satisfactory for the application. The basic fabrication technique was refined to eliminate undesirable large pores and cracks often present in materials fabricated by earlier techniques. Also, processing was scaled up to increase the fabrication rate by a factor of 10. The specific properties of the CBCF were ...

1985-05-01

350

Carbon-bonded carbon fiber insulation for radioisotope space power systems  

Energy Technology Data Exchange (ETDEWEB)

A carbon-bonded carbon fiber (CBCF) insulation developed for a radioisotope heat source is made from chopped rayon fiber about 10 ..mu..m in diameter and 250 ..mu..m long, which is carbonized and bonded with phenolic resin particles. The CBCF is an excellent lightweight insulating material with a nominal density of 0.2 Mg/m/sup 3/ and a thermal conductivity of 0.24 W/(m-K) in vacuum at 2000/sup 0/C. Several attributes that make CBCF particularly suitable for the heat source application have been identified. These include light weight, low thermal conductivity, chemical compatibility, and high-temperature capabilities. The mechanical strength of CBCF insulation is satisfactory for the application. The basic fabrication technique was refined to eliminate undesirable large pores and cracks often present in materials fabricated by earlier techniques. Also, processing was scaled up to increase the fabrication rate by a factor of 10. The specific ...

1985-05-01

351

Calculation of the transmission capacity of long-distance EHV single-core submarine cable systems  

Energy Technology Data Exchange (ETDEWEB)

A general calculation method for the analysis of transmission capability of a long-distance single-core ac submarine cable system is presented. The method is based on modal transformation of voltages and currents in multiconductor cable systems. Using this method, numerical calculations on 500 kV submarine cable systems have been performed with particular reference to the effect of the distance between bonds connecting metallic sheath, outer conductor and armor on the transmission capacity of the system. It was clarified that the transmission capacity of the system increased with decreasing bond intervals. Examination of the current distributions between various conductors along the length showed that this increase of transmission capacity was mainly due to the dispersion of the charging current into the metallic sheath, outer conductor and armoring at the bonding points. Analytical results for the transmission capacities ...

1981-11-01

352

Bonding exterior grade structural panels with copolymer resins of biomass residue components, phenol, and formaldehyde  

Energy Technology Data Exchange (ETDEWEB)

Components of various forest and agricultural residue biomass-including the polyphenolic compounds-were converted into aqueous solution and/or suspension by extraction and digestion. Some biomass components reacted vigorously under alkaline catalysis with formaldehyde and initially showed a high degree of exothermic reaction; however, other components did not react as vigorously under these conditions, indicating that different biomass materials require different methods to obtain optimum reactivity for the copolymerization with phenol. Our primary goal is to develop adhesives capable of producing acceptable bond quality, as determined by the wood products industries` standards, under a reasonable range of gluing conditions. Copolymer resins of phenol, formaldehyde, and biomass components were synthesized and evaluated for gluability of bonding exterior grade structural replaced with chemicals derived from peanut hulls, pecan shell flour, pecan ...

1993-12-31

353

Bond cleavage reactions of the bridge structure in coal in the presence of hydrogen donating compounds; Suiso kyoyosei kagobutsu sonzaika deno sekitanchu no kakyo kozo no kairetsu hanno  

Energy Technology Data Exchange (ETDEWEB)

In this paper, bond cleavage reactions are discussed in relation to the softening and solubilization of coal. Were used 9,10-dihydroanthracene (DHA) and 9,10-dihydrophenanthrene (DHP) as models of hydrogen donating compounds in coal, and bibenzyl, 1,2-diethane, benzylphenylether, and 1,5-dibenzylnaphthalene were used as models of bridge structure compounds. They were compared mutually, as to reactivity of coal against DHA and DHP. For the homolytic cleavage of bridges, DHA with excellent radical supplement performance provided excellent hydrogen donating performance. While, for the ipso-position cleavage of bridges, it was found that DHP can act as an effective hydrogen donor. For the reaction between coal and hydrogenated aromatic compounds, cleavage of relatively weak bonds, such as ether linkage and dimethylene linkage, occurred at about 380{degree}C, and hydrogen from DHA or DHP was consumed. On the other hand, the results suggested that ...

1996-10-28

354

Applications or radiation polymerization hardening to composites  

International Nuclear Information System (INIS)

Comprehensive investigation has been made into the application of the polymerization hardening by radiation, particularly electron beam, to the composites of polymers and other materials. The report is divided into four parts, namely 1) characteristics and problems of the reaction of curing by radiation polymerization, 2) improvement of the bonding capability of high molecular weight materials, 3) bonding by radiation, and 4) composites made by the impregnation and polymerization hardening of monomers. The first part includes the effects of dose rate, temperature rise during the hardening, the peculiarity of electron beam irradiation at high dose rate, reaction environment and additive effects. Main conclusions are as follows: caution must be taken to the amount of residual double bonds because they affect the quality of hardened polymers; the polymerization hardening reaction at high dose rate cannot be analogized by that ...

1976-01-01

355

A joint computational and experimental study of a novel dioxomolybdenum(VI) complex bearing chiral N,N-dimethyllactamide ligand  

British Library Electronic Table of Contents (United Kingdom)

A new cis-dioxomolybdenum complex MoO2(DMLA)2 (DMLA=N,N-dimethyllactamide) has been synthesized and characterized by X-ray crystallography, H NMR and IR spectroscopies and electronic structure calculations at DFT/B3LYP level. This compound (chemical formula C10H20MoO6N2) crystallizes in the orthorhombic space group P212121 with Z=4, a=6.9357(2)?, b=11.8761(4)?, c=17.7251(5), V=1460.00(8)?3 and renders a slightly distorted octahedral structure with two long Mo-O bonds (2.253(3)? and 2.257(3)?) trans to each of the MoO groups and with two short Mo-O bonds of 1.942(3)4? cis to them. The MoO bond length are 1.715(3) and 1.704(3)?). Each lactamide ligand is bidentate; they are coordinated in their deprotonated form with the carbonyl oxygen occupy...

2011-01-01

356

Possible global environmental impacts of solid waste practices  

Energy Technology Data Exchange (ETDEWEB)

Pollutants resulting from the management of solid waste have been shown to affect the air, land, oceans, and waterways. In addition, solid wastes have other, more indirect impacts such as reduction in feedstocks of natural resources, because useful materials are disposed of rather than recycled. The objective of this study is to evaluate solid waste management practices that have negative implications on the global environment and develop recommendations for reducing such impacts. Recommendations identifying needed changes are identified that will reduce global impacts of solid waste practices in the future. The scope of this study includes the range of non-hazardous solid wastes produced within our society, including municipal solid waste (MSW) and industrial solid waste (ISW), as well as industry-specific wastes from activities such as ...

1994-09-01

357

Nanocrystal conversion chemistry: A unified and materials-general strategy for the template-based synthesis of nanocrystalline solids  

International Nuclear Information System (INIS)

The concept of nanocrystal conversion chemistry, which involves the use of pre-formed nanoparticles as templates for chemical transformation into derivative solids, has emerged as a powerful approach for designing the synthesis of complex nanocrystalline solids. The general strategy exploits established synthetic capabilities in simple nanocrystal systems and uses these nanocrystals as templates that help to define the composition, crystal structure, and morphology of product nanocrystals. This article highlights key examples of 'conversion chemistry' approaches to the synthesis of nanocrystalline solids using a variety of techniques, including galvanic replacement, diffusion, oxidation, and ion exchange. The discussion is organized according to classes of solids, highlighting the diverse target systems that are accessible using similar chemical concepts: metals, oxides, chalcogenides, phosphides, ...

2008-07-01

358

Carbon dioxide purification through two-stage combustion ENCAP. Final report; Koldioxidrening med tvaastegsforbranning ENCAP. Slutrapport  

Energy Technology Data Exchange (ETDEWEB)

Chemical-looping combustion (CLC), has previously been studied as a method for separating CO{sub 2} during combustion of gaseous fuels. In this project the possibility to apply this process for direct use of solid fuels has been investigated. The following has been accomplished: A 10 kW reactor system for CLC with solid fuels has been designed and built. Tests with solid fuel and metal oxid particles in a laboratory reactor show that it is possible to oxidize solid fuels with metal oxide particles in cyclic testing, thus giving proof of basic concept. They also show how the reaction rate is affected by temperature, steam concentration etc., and, most important of all, that the rates of reaction are realistic. Tests with metal oxide materials available at low costs have been successful. Chemical-looping combustion with solid fuels has a potential to achieve very low costs for ...

2006-06-15

359

Use of thin glass reflectors for solar concentrators  

Science.gov (United States)

Elastically deforming thin glass (thickness = 0.13 to 0.80 mm) provides an alternate method of forming a curved glass reflector which can eliminate some of the disadvantages of thicker glass. A concept is described where silvered thin glass is bonded to a steel backing to form a laminate with a reflectance greater than 93%. Subsequent bending of the flat reflector laminate to a concentrating profile produces compressive stresses throughout the glass if the laminate is properly designed. These compressive stresses enhance fracture resistance and the lamination provides protection for the silver. The design of the laminate is outlined for 0.25 and 0.51 mm thickness glass and fabrication procedures are discussed. Thermal/humidity cycling, hail impact, bond strength measurements and reflectance results are presented which demonstrate the performance capabilities of this reflector laminate concept.

1980-01-01

360

Thermal-mechanical behavior of the bonding wire for a power module subjected to the power cycling test  

British Library Electronic Table of Contents (United Kingdom)

Two analytical methods were proposed in this research, coupled electro-thermal finite element (FE) analysis and thermal-mechanical FE analysis, to analyze the mechanical behavior of bonding wire of power module under cyclic power loads, and the International Electrotechnical Commission standard is adopted in conducting a power cycling test. The exterior temperature distribution was measured by an infrared thermometer. Moreover, the junction temperature is calculated from the given thermal impedance of the semiconductor chip, chip power loss, and case temperature. Subsequently, the simulated temperature distribution via electro-thermal FE analysis is compared with experimental results to validate the methodology used in the aforementioned analysis. The analysis shows compressive stress at t...

2011-01-01

361

Thermal and Mechanical Characterizations of Nanomaterial-Modified Adhesive Used in Bonding CFRP to Concrete  

British Library Electronic Table of Contents (United Kingdom)

Nanomaterials are increasingly being used to modify adhesives used in aerospace and materials applications. Improvements in thermal and mechanical properties have been found by incorporation of small amounts of nanosize materials in to such adhesives. However, the introduction of nanomaterials to adhesives used in civil engineering applications is still a new approach which needs to be explored, especially in retrofitting of structures. This paper presents part of an ongoing research to address the effect of adding nanomaterials to modify a thermosetting adhesive used for bonding carbon fibre reinforced polymer (CFRP) composites to concrete members. Vapour grown carbon fiber (VGCF) was chosen to modify the adhesive. Different concentrations of carbon nanofibres PR-24 XT-LHT were adopted fo...

2011-01-01

362

Synthesis by plasma and characterization of semiconductor compounds derived of polyacetylene; Sintesis por plasma y caracterizacion de compuestos semiconductores derivados del poliacetileno  

Energy Technology Data Exchange (ETDEWEB)

In this work it is made a study of the structure and electric properties of chlorate polyethylene (PE-CI) with double and simple bonds obtained by continuous plasma with resistive coupling to 13.5 MHz. The synthesis conditions are power between 10 and 14 W and pressure of (6-7) x 10{sup -2} Torr. The synthesized PE-Cl in that way is soluble in acetone what indicates that probably is formed of short chains and not it shows the generalized inter crossing that is presented in some syntheses by plasma and that it can degrade the electric properties of these polymers. The IR and XPS analysis show the vibration of the C-C, C=C and C-CI bonds. The morphology of the polymer after being dissolved shows a compact and flat configuration. The electric conductivity has an approximately lineal behavior in an interval of 35 to 90% of relative humidity. (Author)

2003-07-01

363

Synthesis and investigation of #pi#-conjugated azomethine self-assembled multilayers by layer-by-layer growth  

International Nuclear Information System (INIS)

Layer-by-layer formation for #pi#-conjugated azomethine multilayers bonded on substrates was investigated. The multilayers were synthesized using ethanol (EtOH) and dichloromethane (DCM) as reaction solvents. The multilayer characteristics were analyzed using UV-vis absorption spectroscopy, ellipsometric thickness, and atomic force microscopy. The absorption spectra and ellipsometric thicknesses of multilayers formed using EtOH and DCM were compared. The results indicate that EtOH is more suitable than DCM for such layer-by-layer formation. In addition, bandgaps estimated from the absorption edge of multilayers were investigated. The results indicate that the bandgap decreases as the number of benzene rings contained in the molecular chain of the multilayer increases. Also, a multilayer with four benzene rings bonded on a substrate had a bandgap close to that of a polymer with a similar chemical structure.

2010-07-01

364

Study on the spatial structure of annomuricatin A, a cyclohexapeptide from the seeds of Annona muricata  

British Library Electronic Table of Contents (United Kingdom)

A cyclic hexapeptide, annomuricatin A (the molecular formula: C27H38N6O7), was isolated from the seeds of Annona muricata. The types and sequence of the amino acids were confirmed by X-ray diffraction analysis. The stereochemistry of the title cyclopeptide was clarified by X-ray crystallographic study. The backbone contains two b-turns, one is type I b-turn and the other is type II, which are stabilized by two transannular 41 backbone hydrogen bonds between Ala and Phe. There are intermolecular hydrogen bonds between the cyclopeptide and the solvent molecules which maintained the steady spatial arrangement in crystal.

2007-01-01

365

Studies of coupled chemical and catalytic coal conversion methods  

Science.gov (United States)

The objective of this research was to convert coal into a soluble substance under mild conditions. The strategy involved two steps, first to breakdown the macromolecular network of coal, and second to add hydrogen catalytically. We investigated different basic reagents that could, in priciple, break down coal's structure and alkylation strategies that might enhance its solubility. We examined O- and C-alkylation, the importance of the strength of the base, the character of the added alkyl groups and other reaction parameters. This work provided new information concerning the way in which hydrogen bonding, polarization interactions between aromatic structures and covalent bonding could be disrupted and solubility enhanced. The objective of our research was to explore new organochromium chemistry that might be feasible for the hydrogenation of coal under mild conditions.

1991-12-01

366

Spectrophotometric study of lanthanoid complexes with antipyrine and salicylic acid  

International Nuclear Information System (INIS)

The extraction-spectrophotometric method has been used to study lanthanoid ion complexing (Pr, Nd, Ho and Er) with antipyrine (Ant) and salicylic acid (Sal). The component relationship in different-ligand compounds Ln:Aut:Sal=2:3:6 and solvate number equal to 5 are determined; molar extinction coefficients of binary and different-ligand compounds are calculated. Oscillator strengths of absorption bands corresponding to supersensitive transitions of neodymium, holmium, erbium and some most intensive praseodymium bands are calculated. The study of IR spectra of investigated compounds allows to conclude on formation of coordination bonds of the central atom with the antipyrine molecule through the oxygen of the carbonyl group as well as on carboxyl group hydrogen substitution for metal and formation of coordination bond with OH group in salicylic acid molecules.

1981-01-01

367

Radial distribution of material in a bond mill determined by radiotracer-technique  

International Nuclear Information System (INIS)

A steadily increasing part of comminution is nowadays carried out by tube ball mills. Our investigations are a first step to a possible tuning of material distribution with mechanical stress characteristic of the grinding media charge, that is essential for a high efficiency of grinding. A BOND mill filled with porcelain balls as grinding media and labelled corundum (Au-198) as grinding material was used to measure the distribution of material over the cross-section. The evaluation was made by linear interpolation between all combinations of adjacent measuring points to calculate all coordinates with equal intensity for each selected level of activity. Two plottings showing the dependence of material distribution on the rotating speed are presented. (author).

1985-09-23

368

Preparation and properties of environmental friendly nonhalogen flame retardant melamine cyanurate/nylon 66 composites  

British Library Electronic Table of Contents (United Kingdom)

Abstract Melamine cyanurate (MCA) was utilized as an environmental friendly additive to prepare the nonhalogen flame retardant MCA/Nylon 66 composites by melt blending technique. Because of the strong hydrogen bond interactions and fine interfacial compatibility between MCA and Nylon 66, the resultant even dispersion of MCA filler in polymer matrix leads to the better toughness and strength of MCA/Nylon 66 composites than those of neat Nylon 66. Both Nylon 66 and MCA/Nylon 66 composites exhibit similar -crystalline structure, but the presence of MCA influences the distribution of 1 and 2 crystalline phases in Nylon 66 by inducing its hydrogen-bonded sheet separation. Moreover, the blending of MCA and Nylon 66 increases the crystallization temperature and exothermicity but decreases the the...

2011-01-01

369

Optimal design and preparation of beta-SiAlON multiphase materials from natural clay  

International Nuclear Information System (INIS)

Beta-SiAlON powders have been synthesized using natural clay containing kaolin and quartz by carbothermal reduction and nitridation (CRN), then beta-SiAlON bonded corundum multiphase materials have been sintered using the as prepared powders. The results indicated that both the holding time and sintering temperature are relatively significant in accordance with optimal analysis by orthogonal method. Reaction process can be briefly interpreted by means of X-ray Diffraction and Difference Temperature Analysis as well as phase diagram principle. Bending strength and bulk density were measured in SiAlON in situ bonded corundum materials with doped various sintering agents. Furthermore, the relevant mechanical properties and microstructure were discussed in detail.

370

Molecular structure of platinum(III) hydroxoacetates according to data from EXAFS spectra  

Energy Technology Data Exchange (ETDEWEB)

The EXAFS spectra of the platinum(III) complexes Pt/sub 4/(OAc)/sub 10/(OH)/sub 2/ (I) and Pt/sub 4/ (OAc)/sub 4/(OH)/sub 8/(H/sub 2/O)/sub 2/ (II) have been investigated. It has been found by a curve-fitting method and with the aid of Fourier transformations that the shortest Pt-Pt distances are 2.61 A in complex I and 2.36 and 2.6 A in II. The values of the bond lengths obtained are consistent with the molecular structures proposed for complexes I and II, which contain skeletons of four platinum atoms in the form of a square or a rectangle, as well as with the known literature data on the lengths of Pt-Pt bonds in Pt(III) complexes.

1986-04-01

371

Micro-patterning of chemical functionality of anthracene-bis-resorcinol film using focused ion beam  

International Nuclear Information System (INIS)

Anthracene-bis-resorcinol is an interesting molecule as it forms a hydrogen-bonded network when guest molecules with weak polarity are included. Focused ion beam (FIB) was irradiated on a part of its amorphous film with low dose, and the film was exposed to the vapor of guest molecules. From fluorescence and AFM analyses of this film, it was found that no inclusion compound was formed in FIB irradiated area, i.e. FIB irradiation suppresses the ability to form the inclusion compounds. By utilizing this phenomenon, we succeeded in a microfabrication of relief structures consisting of inclusion compounds which has different fluorescence from its surrounding. Morphology, fluorescence, and IR absorption analyses indicated that hydroxyl or resorcin groups are damaged by ion beams, and consequently a formation of hydrogen-bonded networks, which play a role of a lattice caging guest molecules, becomes impossible.

2005-12-15

372

Manufacture and first wall joining for an ITER primary wall module prototype: R and D phase with small scale mock-ups  

International Nuclear Information System (INIS)

In the frame of the Primary Wall Module prototype manufacturing for ITER, a consistent R and D phase was conducted in order to identify the industrial allowable tolerances and manufacturing problems which would occur when joining pieces by HIPping process during the PW module manufacturing. The purpose of this development was to give as industrial as possible manufacturing routes for joining together large Stainless Steel or DS-Copper pieces with Stainless Steel tubes and for bonding Beryllium tiles onto a curved component surface. The study concerned surface preparations, allowable gaps and joint geometry, Beryllium tile geometry, Titanium interlayer thickness, etc. This R and D phase also allowed the development and validation of different ultrasonic inspection tools needed for plate-plate, tube-plate, edge to edge plate bonding.

2001-10-01

373

Luminescence properties of Ca- and Yb-codoped SiAlON phosphors  

International Nuclear Information System (INIS)

Luminescence properties of SiAlON phosphors codoped with Ca and Yb were investigated by changing the host lattice composition. These modifications of the host lattice were obtained by replacing Si-N bonds by Al-N and Al-O bonds. Their photoluminescence (PL) and cathodoluminescence (CL) properties were measured and compared with each other. PL allows observing the influence of the host lattice modifications by measuring wider areas. CL can excite all luminescent centers, in particular the UV luminescence centers, even if their amount is small. Thus, two additional peaks in the ultraviolet and infrared regions were observed in CL, which is not observed by PL. This work suggests that the combination of PL and CL gives more understanding about the luminescence of SiAlON phosphors, in particular the role of the secondary phases on their properties.

2008-01-15

374

Influence of FeSO4 concentration on thermal emissivity of coatings formed on titanium alloy by micro-arc oxidation  

British Library Electronic Table of Contents (United Kingdom)

Ceramic coatings with high emission were fabricated on Ti6Al4V alloy by microarc oxidation (MAO) with additive FeSO4 into the electrolyte. The microstructure, chemical composition and chemical state of the coatings were determined by SEM, XRD, EDS and XPS, respectively. The bonding strength between the coating and substrate was studied by tensile strength test, together with the thermal shock resistance of the coating. The results showed that Fe content in the coating layer significantly affect its thermal emissivity. The relative content of Fe in the coatings surface increased at first and then decreased with increasing the concentration of FeSO4 in electrolytes, so does the emissivity of the coatings. The bonding strength became weaker with increasing the concentration of FeSO4. In addit...

2011-01-01

375

Important effects of neighbouring nucleotides on electron induced DNA single-strand breaks  

British Library Electronic Table of Contents (United Kingdom)

In this Letter, we present Quantum Mechanics/Molecular Mechanics (QM/MM) calculations on molecules containing a 2-deoxycytidine-3prime-monophosphate moiety (3prime-dCMPH). In particular, we examine the effect that including neighbouring nucleotides at the Molecular Mechanic (MM) level has on the calculated electron affinities and on the energetic barriers of the C3prime-O3prime bond cleavage. Our results demonstrate that the surrounding nucleotides relocate the excess electron from the p* orbital of the base to a diffuse phosphate-centred orbital, leading to the formation of a dipole-bound anion state. Both the electron affinities and the activation energy of C3prime-O3prime bond cleavage are strongly increased.

2009-01-01

376

Ground state energies and nuclear density distribution in the coherent flucton model  

Energy Technology Data Exchange (ETDEWEB)

The coherent flucton model is applied to the description of some basic nuclear properties, such as: ground state energies, bond energies, nucleon momentum spectra, and nuclear density distributions. It is shown that the momentum distributions of the nucleons coincide with the Fermi distribution for small momenta and exhibit a well pronounced high energy ''tail'', thus providing inclusive reactions of pi-meson generations in kinematically forbidden areas at nucleon-nucleon collisions. Analytical expressions for the bond energy and nuclear density distribution are derived. An agreement with the experimentally obtained data is achieved. The model features are discussed referring to the processes, characterized mainly by the geometric and dynamic properties of the nuclei, as well as by nuclear density distribution. In particular, ion-ion scattering processes at high energy are considered.

1980-01-01

377

Ground state energies and nuclear density distribution in the coherent flucton model  

International Nuclear Information System (INIS)

The coherent flucton model is applied to the description of some basic nuclear properties, such as: ground state energies, bond energies, nucleon momentum spectra, and nuclear density distributions. It is shown that the momentum distributions of the nucleons coincide with the Fermi distribution for small momenta and exhibit a well pronounced high energy ''tail'', thus providing inclusive reactions of pi-meson generations in kinematically forbidden areas at nucleon-nucleon collisions. Analytical expressions for the bond energy and nuclear density distribution are derived. An agreement with the experimentally obtained data is achieved. The model features are discussed referring to the processes, characterized mainly by the geometric and dynamic properties of the nuclei, as well as by nuclear density distribution. In particular, ion-ion scattering processes at high energy are considered.

378

Comparison of the Influence of Temperature on the High-Strain-Rate Mechanical Responses of PBX 9501 and EDC37  

British Library Electronic Table of Contents (United Kingdom)

Many high-strain-rate compression measurements (2000 per second) using a specially designed split Hopkinson pressure bar (SHPB) for the plastic-bonded explosive PBX9501 have been reported in the literature, but there is a sparsity of data for a United Kingdom polymer-bonded explosives (PBX) known as EDC37. Both EDC37 and PBX9501 are cyclotetramethylenetetranitramine-based (HMX-based) PBXs with high filler contents. The binder systems for the PBXs are very different: EDC37 consists of a nitroplasticized nitrocellulose and PBX9501 a nitroplasticized ESTANE. PBX9501 exhibits nearly invariant fracture strains of ?1.5?pct as a function of temperature at high strain rates, whereas EDC37 fails at ?2 to 2.5?pct. The maximum compressive strengths for both PBXs were measured at 150?Mpa at ?55??C, bu...

2008-01-01

379

Comparison of constitutive models for plastic-bonded explosives  

British Library Electronic Table of Contents (United Kingdom)

A constitutive model for an explosive consists of three parts: equation of state of reactants, equation of state of products, and reaction rate. In the absence of a good physical theory, models are empirical and based on heuristics. For the HMX based plastic-bonded explosive PBX 9501, three models have previously been calibrated and used in numerical simulations. Here, these three models are compared. They illustrate several generic difficulties with developing and validating models. The available data is insufficient to determine a constitutive model uniquely. Different models can be calibrated to fit the available data yet differ significantly in regions of phase space of importance to applications. Comparing models gives an indication of the uncertainty in model predictions outside the ...

2008-01-01

380

A computational study of aluminum phosphide nanotubes  

British Library Electronic Table of Contents (United Kingdom)

Abstract Electronic structures of two representative zigzag and armchair models of aluminum phosphide nanotube (AlPNT) were investigated by density functional theory calculations. The structures were optimized and the bond lengths, tip diameters, band gaps, and dipole moments were calculated. Moreover, the quadrupole coupling constants (CQ) were calculated for the Al-27 atoms of the optimized structures. The same values of AlP bond lengths were calculated for both models. The larger value of band gap of armchair model than the zigzag model indicated the stronger dielectric property for the former model. The values of CQ(27Al) were the largest for the Al atoms placed at the tips of both zigzag and armchair AlPNT than other Al atoms, which could reveal dominant role of the Al atoms placed at...

2011-01-01

381

Study of heavy-ion reactions with the unstable Nuclei, {sup 11}Be and {sup 13}N  

Energy Technology Data Exchange (ETDEWEB)

Heavy-ion reaction with unstable nuclei, {sup 13}N and {sup 11}Be, {sup 13}N+{sup 12}C and {sup 11}Be+{sup 12}C-{sup 10}Be+{sup 13}C were analyzed by a coupled-reaction-channel (CRC) method and formation of valence nucleon molecular orbital was studied by numerical analysing calculation. In this report, 1P1/2 (the ground state of {sup 13}N and {sup 13}C), 2s1/2 (the ground state of {sup 11}Be), 1d5/2 and 1d3/2 orbital were studied as one particle state of valance nucleon in {sup 13}N, {sup 13}C and {sup 11}Be. Moreover, d3/2 state, comparatively higher excited state, was contained into CRC calculation. The effect of this state on CRC scheme was proved very large. We developed new program code to obtain the numerical stable solution. It is necessary to about 200 MB (CRC equation) for {sup 11}Be+{sup 12}C{yields}{sup 10}Be+{sup 13}C and about 300 MB for discussion about molecular orbital. We show that the CRC calculation with the inelastic transitions and the ...

1996-06-01

382

Lithium intercalation into {alpha}-Fe{sub 2}O{sub 3} obtained by mechanical milling of {alpha}-FeOOH  

Energy Technology Data Exchange (ETDEWEB)

Crystalline {alpha}-Fe{sub 2}O{sub 3} powder was prepared by the mechanical milling of crystalline {alpha}-FeOOH at room temperature in air. This result means that crystalline {alpha}-FeOOH is dehydrated by mechanical milling at room temperature. The obtained {alpha}-Fe{sub 2}O{sub 3} powder worked as a rechargeable electrode material in lithium ion conductive organic electrolytes. The electrodes exhibited high discharge capacities of over 1000mAhg{sup -1} corresponding to 6 Li per {alpha}-Fe{sub 2}O{sub 3} at potentials ranging from the open circuit potential to 0.5V (versus Li{sup +}/Li) in the first discharging (lithium insertion) process. This suggests that the valence deviation from Fe{sup 3+} in {alpha}-Fe{sub 2}O{sub 3} to Fe{sup 0} may be caused by electrochemical reduction. In contrast, after the first discharge, the electrodes exhibited high charge capacities of more than 700mAhg{sup -1} corresponding to 4.2 Li per {alpha}-Fe{sub 2}O{sub 3} in the first ...

2005-08-26

383

Catalytic effect of niobium oxide on hydrogen storage properties of mechanically ball milled MgH{sub 2}  

Energy Technology Data Exchange (ETDEWEB)

We examined a catalytic effect of niobium oxide (Nb{sub 2}O{sub 5}) on the hydrogen storage properties of MgH{sub 2} prepared by mechanical ball milling method. The MgH{sub 2} composite doped with 1 mol% Nb{sub 2}O{sub 5} by ball milling for 20 h desorbed hydrogen up to {approx}6 mass% in the temperature range from 200 to 250 {sup o}C at the heating rate of 5 {sup o}C/min under a purified helium flow. After dehydrogenation at 200 {sup o}C, the product showed remarkable hydrogen absorption kinetics. A large amount of gaseous hydrogen up to {approx}4.5 mass% was absorbed even at room temperature under 1 MPa hydrogen pressure within 15 s and finally its capacity reached up to 5 mass%. Furthermore, the valence state of Nb{sub 2}O{sub 5} doped in MgH{sub 2} was examined by X-ray absorption near edge structure (XANES) measurement. The results indicated that additive Nb{sub 2}O{sub 5} was reduced by MgH{sub 2} during mechanical milling. This suggests that the Nb compound, ...

2006-08-15

384

Water in polymer membranes. 4. Raman scattering from cellulose acetate films  

Energy Technology Data Exchange (ETDEWEB)

Raman scattering was observed from thin film optical waveguides of cellulose acetate exposed to water vapor from 0% to 100% relative humidity (RH), and from dilute solutions of water in methyl acetate. Spectra of cellulose acetate (CA398, 39.8% acetyl) at low RH and cellulose triacetate (CTA) at low and high RH are consistent with the presence of water monomers that are weakly hydrogen bonded to acetyl C=O groups. Differences between the spectra of water in CA398 and CTA at low RH are attributed to sequential hydrogen bonding involving OH groups in CA398. At high RH, CA398 and CTA (to a lesser extent) show bands attributed to water/water interactions that are similar to those found in sequentially hydrogen-bonded hydrates. CA398 films that are annealed at high temperatures exhibit decreased water/water interactions at high RH. Exposure of CA398 films to D/sub 2/O converts > 90% of all polymer OH groups to OD groups. This ...

1985-01-17

385

Water contents of samples from the Nevada Test Site: total, free (natural state to 105/sup 0/C), and more tightly bonded (105 to 700/sup 0/C)  

Energy Technology Data Exchange (ETDEWEB)

To help confirm correct functioning of an epithermal neutron sonde, we measured tightly bonded water content of selected Nevada Test Site (NTS) drill holes. Tuff and alluvium samples were dried overnight at 105/sup 0/C. The samples were then heated for 45 min in a split tube furnace at 700/sup 0/C. The water that came off due to this heating was collected and the amount recorded. The error in this procedure is +- 0.59 wt %. Total water can be calculated for samples from analyses of free and tightly bonded water contents. The maximum error in this calculation is equivalent to the error in determining the more tightly bonded water. Average total water content values have been assigned to geologic units. These values, in weight fraction, are alluvium 0.14 +- .05 and tuff 0.19 +- .04. Further division of the tuff gives values of Rainier Mesa 0.15 +- .01, Paintbrush 0.18 +- .03, Tunnel Beds 0.20 +- .04, and Grouse Canyon 0.29 +- ...

1981-05-01

386

The chemical properties of silica particle surface in relation to silica-cell interactions  

Energy Technology Data Exchange (ETDEWEB)

Although silicosis has been studied extensively, the mechanism is still not fully understood. Experiments do provide evidence that the actions of unique properties of silica surface on the cell membrane are the starting point of silicotic processes. This paper summarizes literature on chemical properties of silica surface, and the effect of particle size on silica toxicity. This paper also discusses the ways in which silica dusts are though to interact with the cell membrane, with emphasis on freshness, hydrogen bonding, and free-radical interactions.

1989-01-01

387

The adiabatic engine:Global developments  

Energy Technology Data Exchange (ETDEWEB)

This book presents papers on internal combustion engines. Topics considered include the influence of partial suppression of heat rejection on performance and emissions, duothermic combustion, turbochargers made of sintered silicon nitrides, heat flux, low heat rejection engines, exhaust energy recovery, combustion chamber insulation, computerized simulation, heat transfer, friction, hoop stress effects, and bonding ceramics and metals.

1986-01-01

388

Ternary aluminides LnPd[sub 2]Al with YPd[sub 2]Si-type structure  

Energy Technology Data Exchange (ETDEWEB)

Attempts to synthesize YPd[sub 2]Si-type representatives LnPd[sub 2]Al were successful only with Ln triple bond Ce, Pr, Nd. This orthorhombic structure (oP16; space group Pnma) is an ordered variant of the Fe[sub 3]C type. Only NdPd[sub 2]Al undergoes magnetic ordering above 2 K. (orig.)

1993-04-13

389

Structure, physical and photophysical properties of platinum(II) complexes containing bidentate aromatic and bis(diphenylphosphino)methane as ligands  

Energy Technology Data Exchange (ETDEWEB)

This study focuses on a series of Pt{sup II}(L-L{prime})(dppm){sup n+} complexes, where dppm is bis(diphenylphosphino)methane and L-L{prime} are C(caret)C{prime} (n = 0), C(caret)N (n = 1), and N(caret)N{prime} (n = 2) aromatic ligands. Structural characteristics are reported. Structural features indicate that the Pt-C bond distance is shorter than the Pt-N bond distance in symmetrical complexes and that the Pt-P bond distance trans to N is shorter than the Pt-P bond trans to C. This is consistent with the {sup 31}P NMR spectra where the chemical shift of the P trans to C is {approximately}10 ppm less than found for P trans to N. The energy maxima of the metal-to-ligand charge-transfer band for the complexes containing various L-L{prime} ligands occur in the near-UV region of the spectrum and fall into the energy series bpy > bph > phen > 2-phpy > 2-ptpy > 2-phq ...

2000-05-01

390

Sorption of heteropoly acids by polyurethane foam  

International Nuclear Information System (INIS)

Sorption of oxidized and reduced forms of molybdosilicic, molybdophosphoric and molybdovanadophosphoric acids by polyurethane foam based on ethers and esters is studied. On the basis of sorption dependence on solution pH, polyurethane foam type and spectral characteristics of sorbates the suggestion has been made that in the polyurethane foam phase there are two main types of sorbent-sorbate interaction: electrostatic (ion-ion) and with hydrogen bond formation: and it is impossible to determine the contribution of every interaction

1997-12-01

391

Quantifying octahedral rotations in strained perovskite oxide films.  

Energy Technology Data Exchange (ETDEWEB)

We have measured the oxygen positions in LaNiO{sub 3} films to elucidate the coupling between epitaxial strain and oxygen octahedral rotations. The oxygen positions are determined by comparing the measured and calculated intensities of half-order Bragg peaks, arising from the octahedral rotations. Combining ab initio density-functional calculations with these experimental results, we show how strain systematically modifies both bond angles and lengths in this functional perovskite oxide.

2010-07-20

392

Polaron model of electron spectra and superconductivity of A-15 compounds  

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.

1983-02-01

393

Polaron model of electron spectra and superconductivity of A-15 compounds  

International Nuclear Information System (INIS)

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 tehrmal capacity.

394

Nonformity of the electron density in amorphous silicon films  

Energy Technology Data Exchange (ETDEWEB)

The authors study the nonuniformity of a-Si:H films obtained by the method of vacuum condensation, with the help of x-ray small-angle scattering (SLS) and transmission electron microscopy. Films of hydrogenated amorphous silicon are greatest interest, because the electronic properties of this material can be controlled by doping. As a result of the compensation of the ruptured bonds, and possibly, effects of melting, the properties of such films are analogous to those of singlecrystalline silicon. XLS enables a quantitative determination of the prameters of the regions of low electron density (RLD) in such objects.

1985-12-01

395

Mutations at the accommodation gate of the ribosome impair RF2-dependent translation termination  

UK PubMed Central (United Kingdom)

During protein synthesis, aminoacyl-tRNA (aa-tRNA) and release factors 1 and 2 (RF1 and RF2) have to bind at the catalytic center of the ribosome on the 50S subunit where they take part in peptide bond...Full Text Available

2010-09-01

396

Magnesium foam produced from bulk AZ31 magnesium alloy sheets  

Energy Technology Data Exchange (ETDEWEB)

Using commercial AZ31 magnesium alloy sheets, we produced a foamable preform sheet containing titanium hydride (TiH{sub 2}) powder through diffusion-bonding and hot-rolling of four cycles. Heating the preform sheets in Ar atmosphere, we obtained closed-cell magnesium alloy foams with various porosities. The foamed specimen at 883 K showed the maximum porosities of 77%. (orig.)

2005-07-01

397

Joining of technical ceramics  

International Nuclear Information System (INIS)

Large, complex, high purity ceramic shapes are required by a variety of emerging technologies for their electrical insulation and high temperature strength properties coupled with their refractoriness and purity. Ceramic sealant bonding, using crystalline and vitreous sealant materials, has recently shown significant potential for joining technical ceramics to form the required shapes. Materials and techniques for joining technical ceramics including alumina, magnesia, zirconia and thoria are discussed. (orig.).

398

Hyperfine interactions in HCOOD and DCOOH molecules  

Energy Technology Data Exchange (ETDEWEB)

The method of double microwave--radio-frequency resonance has been used to obtain spectra of the 2/sub 11/reverse arrow2/sub 12/ and 3/sub 21/reverse arrow3/sub 22/ transitions in HCOOD, DCOOH, and HCOOH molecules. The constants of the quadrupole bond of the deuterons have been determined, magnetic interactions being taken into acocunt. A comparison with results of previous studies is given.

1986-05-01

399

Evaluation of PLZT goggles. Final report June 78-April 79  

Energy Technology Data Exchange (ETDEWEB)

Air Force Prototype Thermal Flash Protective Device (TFPD) Goggles were furnished to USAFSAM by the Life Support System Program Office, Aeronautical Systems Division, for determination and evaluation of their eye-type goggles caused stressed areas. The bonding used in the production model eliminated the stressed areas, resulting in increased closed-state optical density, particularly in the upper nasal area of the lens.

1980-12-01

400

Elementary submodels in infinite combinatorics  

CERN Document Server

We show that usage of elementary submodels is a simple but powerful method to prove theorems, or to simplify proofs in infinite combinatorics. First we introduce all the necessary concepts of logic, then we prove classical theorems using elementary submodels. We also present a new proof of Nash-Williams's theorem on cycle-decomposition of graphs, and finally we obtain some new decomposition theorems by eliminating GCH from some proofs concerning bond-faithful decompositions of graphs.

2010-01-01

401

Effect of esters on lubricity of hydrotreated jet fuel  

Energy Technology Data Exchange (ETDEWEB)

The authors synthesized a number of esters of stearic acid with polyhydric alcohols and ran comparative tests on aliphatic alcohols to determine their effects on the antiwear properties of the fuel. They conclude that the differences in effectiveness in improving the lubricity by the use of aliphatic alcohols and the full and partial esters of polyhydric alcohols and stearic acid can be explained by the presence of hydroxyl and ester groups close to each other in partial esters. This is reflected in the higher polarity of the partial esters, a higher rate of adsorption, and a stronger bonding of the adsorbed layer to the metal surface.

1985-07-01

402

Calculation of henry constants for the adsorption of isomeric phenylenediamines on graphitized thermal carbon black  

British Library Electronic Table of Contents (United Kingdom)

Henry constants for the adsorption of o- and p-phenylenediamines on the surface of graphitized thermal carbon black within the temperature range 433?479 K were calculated by the molecular statistical method. The parameters of the atom-atom potential function of intermolecular interaction between the nitrogen atom in aniline and isomeric phenylenediamines and the carbon atom of the basal face of graphite were determined. It was shown that an intramolecular H bond influenced the geometry and adsorption properties of o-phenylenediamine.

2009-01-01

403

Calculation of henry constants for the adsorption of isomeric phenylenediamines on graphitized thermal carbon black  

Science.gov (United States)

Henry constants for the adsorption of o- and p-phenylenediamines on the surface of graphitized thermal carbon black within the temperature range 433-479 K were calculated by the molecular statistical method. The parameters of the atom-atom potential function of intermolecular interaction between the nitrogen atom in aniline and isomeric phenylenediamines and the carbon atom of the basal face of graphite were determined. It was shown that an intramolecular H bond influenced the geometry and adsorption properties of o-phenylenediamine.

2009-12-01

404

Acid/base and hydrogen bonding effects on the proton-coupled electron transfer of quinones and hydroquinones in acetonitrile: Mechanistic investigation by voltammetry, "1H NMR and computation  

International Nuclear Information System (INIS)

This report seeks to address the role of hydrogen bonding with Bronsted acids and bases in proton-coupled electron transfer (PCET) as it pertains to concerted or stepwise pathways of quinone (Q) and hydroquinone (QH_2) electrochemistry. This study was performed using a series of techniques that included cyclic voltammetry (CV), digital simulations, computational chemistry and "1H NMR. Hydrogen bonding was inferred by a decrease in diffusion coefficient (D) values measured using a pulsed gradient echo- (PGE-) "1H NMR technique. Changes of 40.8% and 37.9% in D values were only noted after the addition of two equivalents of acetate to 1,4-hydroquinone (1,4-QH_2) and catechol (1,2-QH_2), respectively. In contrast, the D values for the addition of selected amines (pyridine, N,N-diisopropylethylamine and triethylamine) changed only 3.2% on average. Quantum mechanical calculations were conducted to determine the pK_a of all quinoid species to serve as ...

2010-09-01

405

A nanoscale understanding of the adhesion of polybutylene terephthalate on aluminum  

British Library Electronic Table of Contents (United Kingdom)

The adhesion strength of polybutylene terephthalate (PBT) on aluminum was investigated using density functional theory-based total energy calculations. Aluminum atom was connected to a PBT monomer at different orientations and total energies were calculated in order to determine the most stable orientation. The energy differences showed that the Al oriented at 180degree with the ester group of the monomer bonded strongly. Using this orientation, the PBT monomer-adhesion on aluminum surface and the aluminum atom adhesion on PBT bulk were also investigated.

2007-01-01

406

Solid radioactive waste management in Daya Bay Nuclear Power Station  

International Nuclear Information System (INIS)

This paper introduces the solid radwaste management system, treatment methods and its continuous improvement during the past 9 years in Guangdong Daya Bay Nuclear Power Station (GNPS). GNPS has paid great attention and made a lot of efforts to implement the principle of waste minimization with source control, improvement of treatment process and strict management, so the output of solid radwastes has annually decreased since 1994. In 2002, the output of solid radwastes in GNPS was 63.5 m"3, only 50% of 1995 (127 m"3), reached the advanced level as the same type NPPs in France. During the period 1994-2002, the accumulated production of solid radwaste Packages in GNPS is 1563.51 m"3 only 18% of the design value; all the packages meet the standard and requirement for safe disposal. Besides, this paper analyzes some new technical processes and presents some proposals for further decreasing the ...

2004-05-01

407

Separation of the components of the binary mixture ethanol-water by steam flux in solid phase column; Separacao dos componentes da mistura binaria etanol-agua por passagem do vapor em coluna de fase solida  

Energy Technology Data Exchange (ETDEWEB)

This paper deals with the energy required to separate ethanol from an aqueous solution in a distillation column containing a solid phase. The solid phases evaluated consisted of either an amylatious (ground corn) or a cellulose (sugar cane bagasse) absorber whit particle sizes smaller than 4 mm. The water-retention capacity of each solid phase was measured by passing vapors or ethanol-water mixtures through the solid phase. When starting with initial concentrations bellow the azeotropic point, ethanol concentrations up to 99,5% (on corn) and 97,2% (on sugar cane) were achieved. The water content was evaluated potentiometrically (Karl`Fischer). Regarding the 2-4 mm ground corn solid phase column, the energy consumed was estimated to be reduced by 15,6% and 60% (by weight) ethanol-water mixture respectively. (author) 11 refs., 2 figs., 2 tabs

1987-12-31

408

Promising electrolyte materials for the coming lithium secondary batteries. Lithium ion conductive inorganic solid electrolytes; Jisedai lithium niji denchiyo denkaishitsu. Muki kotai denkaishitsu  

Energy Technology Data Exchange (ETDEWEB)

This paper describes inorganic solid electrolytes from a viewpoint of electrolytes for lithium batteries. Lithium ion conductive inorganic solid electrolytes are largely divided into crystalline and amorphous substances. Crystalline substances are known as LiI and Li3N, and also oxygen acid salt. However, when considering application to a battery, its large grain boundary resistance and electrochemical instability would be a problem. Lithium ion conductive amorphous solid electrolytes are divided into an oxide system and a sulfide system. Since most of them do not contain transition metal elements, they are stable against electrochemical reduction, and ions move isotropically in electrolyte. Therefore, ion conduction paths across the grain boundaries may be connected more easily, forming an electrolyte with low grain boundary resistance. As a result of the efforts of the authors in searching new additives substituting LiI, ...

1997-11-05

409

Operation of a laboratory-scale tubular digester on pigery waste  

Energy Technology Data Exchange (ETDEWEB)

Three inclined tubular digesters of 13- to 15-litre volume were operated at temperatures between 20 and 30 degrees C with hydraulic retention times of 10-15 days on pig slurry of 10%, 5% and 2.5% Total Solids content. Tube inclination of 16-20 degrees gave no scumming problems. Solids were retained, giving improved gas yields when compared with literature values for conventional stirred digesters. Solids retention is affected by the size of the digester exit and appears to be greater with slurry of low solids content. There is a link between the movement of solids and gas along, and out of, the digester which can lead to unstable oscillating gas production. Tracer studies showed soluble components of the slurry mixed throughout the whole volume of the digester in 25% of the hydraulic retention time or less. Solids moved in well dispersed plug flow. Gas ...

1986-01-01

410

Methodology to evaluate the energy associated to the industrial solid wastes: application in a metropolitan region of Campinas, Sao Paulo state, Brazil; Metodologia para avaliacao da energia associada ao residuo solido industrial: aplicacao a regiao metropolitada de Campinas  

Energy Technology Data Exchange (ETDEWEB)

The aim of this work is to the application of a methodology to evaluate the energy associated to the industrial solid wastes in the metropolitan region of Campinas. The methodological route proposed is: the characterization of the research area and the production/management of the industrial solid wastes; the energetic classification and the qualitative/quantitative research of the energy associated to the industrial solid wastes; and, the valuation of the applicability of the energetic utilization mechanisms proposed to the region. This methodology when applied at the Campinas metropolitan region proved to be valid and it resulted in a synthetically presentation of the social and environmental reality of the industrial sector and the destination of the wastes, as well as it indicated the potentialities related to the energetic utilization of the industrial solid waste in the region. With the obtained ...

2004-07-01

411

Maintenance Implementation Plan for solid waste  

Energy Technology Data Exchange (ETDEWEB)

This Maintenance Implementation Plan (MIP) has been developed for. implementation of the US Department of Energy (DOE) Order 4330.4A. Maintenance Implementation Program (DOE 1990) at the Hanford Site Solid Waste complex. It addresses maintenance functions associated with Solid Waste Management, which includes the field operational group and the facilities operational group. An assessment of the existing maintenance programs for Solid Waste was performed, and the results of this assessment were evaluated to determine corrective actions required to bring Solid Waste Maintenance into compliance with the order. The MIP assessment disclosed that most elements defined in the order are currently implemented for Solid Waste. It also identified issues which must be addressed to bring the maintenance function into full compliance with DOE Order 4330.4A. These include documentation of the ...

1992-06-01

412

Henry`s law gas-solid chromatography and correlations of virial coefficients for hydrocarbons, chlorofluorocarbons, ethers, and sulfur hexafluoride adsorbed onto carbon  

Energy Technology Data Exchange (ETDEWEB)

Gas-solid chromatography was used to determine the Henry`s law second gas-solid virial coefficients within the temperature range of 314--615 K for ethane, propane, butane, isobutane, pentane, hexane, heptane, chloromethane, dichloromethane, trichloromethane, tetrachloromethane, trichlorofluoromethane (Freon 11), chlorodifluoromethane (Freon 22), dichlorodifluoromethane (Freon 12), methyl ether, ethyl ether, and sulfur hexafluoride with Carbopack B, a microporous carbon adsorbent. The temperature dependence of the second gas-solid virial coefficients of these adsorbates was used in conjunction with analyses based on a graphical method, a single-surface numeric integration method, a single-surface analytic expression method, and a two-surface analytic expression method to determine the gas-solid interaction energies and other parameters. The interaction energies were correlated with a ratio of the ...

1995-07-01

413

Wet limestone FGD solids analysis by thermogravimetry  

Energy Technology Data Exchange (ETDEWEB)

Wet limestone scrubbing is once again becoming a popular technology for removal of sulfur dioxide (SO{sub 2}) from power plant emissions. Critical to the operation of wet limestone flue gas desulfurization (FGD) systems is accurate chemical analysis of scrubber solids. The analytical technique of thermogravimetry is ideal for this application, as the instrument can give precise readings of the principal scrubber solids components, calcium sulfite/sulfate hemihydrate, calcium sulfate dihydrate (gypsum), and unused calcium carbonate. The data provides plant chemists, engineers, and operators with information needed to fine-tune scrubber operation and detect process upsets. (orig.)

2004-07-01

414

Waste management units - Savannah River Site. Volume 1, Waste management unit worksheets  

Energy Technology Data Exchange (ETDEWEB)

This report is a compilation of worksheets from the waste management units of Savannah River Plant. Information is presented on the following: Solid Waste Management Units having received hazardous waste or hazardous constituents with a known release to the environment; Solid Waste Management Units having received hazardous waste or hazardous constituents with no known release to the environment; Solid Waste Management Units having received no hazardous waste or hazardous constituents; Waste Management Units having received source; and special nuclear, or byproduct material only.

1989-10-01

415

Solid State Photovoltaic Research Branch  

Energy Technology Data Exchange (ETDEWEB)

This report summarizes the progress of the Solid State Photovoltaic Research Branch of the Solar Energy Research Institute (SERI) from October 1, 1988, through September 30,l 1989. Six technical sections of the report cover these main areas of SERIs in-house research: Semiconductor Crystal Growth, Amorphous Silicon Research, Polycrystalline Thin Films, III-V High-Efficiency Photovoltaic Cells, Solid-State Theory, and Laser Raman and Luminescence Spectroscopy. Sections have been indexed separately for inclusion on the data base.

1990-09-01

416

Review on the status of solid radwaste management in Korean NPPs  

International Nuclear Information System (INIS)

To minimize the low and intermediate-level solid radwaste volume, the reduction efforts were persisted in Korean NPPs. As a result, annual average waste volumes were reduced to 194 drums per unit at last year. In this paper we confirmed 250 drums/unit-yr, EPRI URD management goal, and management condition for solid radwaste volume. Also, through the sample assessment of specific Korean NPP opened to the public, we could make sure that the prediction of saturation year for interim storage facility is fully suitable.

2003-10-01

417

Realization of entirely solid lithium ion batteries; Realisation d`accumulateurs a ions lithium entierement solides  

Energy Technology Data Exchange (ETDEWEB)

This paper presents a prototype of an entirely inorganic lithium ions battery cell. LiCoO{sub 2} thin film cathodes and Li{sub 4/3}Ti{sub 5/3}O{sub 4} thin film anodes have been deposited on Li{sub 3x}La{sub 2/3-x}TiO{sub 3} sintered solid electrolyte pellets and the performances of these battery cells have been tested. (J.S.) 5 refs.

1996-12-31

418

Multiple stress aging of solid-dielectric extruded dry-cured insulation systems for power transmission cables  

Energy Technology Data Exchange (ETDEWEB)

A detailed examination of the aging processes that may take place in solid-dielectric extruded-type high voltage transmission cables under dry conditions is presented. Particular emphasis is placed on the aging process as affected by the separate and simultaneous action of four main aging factors, namely the electrical, mechanical and thermal stresses, and the physical and chemical environment. A number of pertinent aging models are considered and their validity and applicability to accelerated aging tests on solid-type transmission cables are discussed.

1994-01-01

419

Heat storage composition  

Energy Technology Data Exchange (ETDEWEB)

A heat storage compostion comprises sodium sulfate decahydrate as main component, a supercooling inhibitor, and a solid-liquid separation inhibitor. The composition is characterized in that hydraulic calcium sulfate and/or calcium sulfate dihydrate is contained as the solid-liquid separation inhibitor in an amount of 2-15 wt% base on the whole weight of the composition, whereby the solid-liquid separation, i.e. the sedimentation of the anhydrous sodium sulfate during the phase transition, is effectively prevented and the long-term stability is improved. The long-term stabilty of the composition can be more improved by addition of a silcia series of thickener.

1987-05-05

420

Feasibility study on the management of the disposal of Bangkok municipal waste. Final report  

Energy Technology Data Exchange (ETDEWEB)

In January, 1985, the Government of Thailand sought assistance from the United States Trade and Development Program (USTDP) to undertake a feasibility study to review and update the solid waste management master plan, with particular emphasis to be placed on waste disposal methods. In April, 1985, the USTDP engaged the firm of Engineering and Economic Research, Inc. to carry out a definitional/prefeasibility study to assess the potential of a project for solid waste management and energy production using municipal solid waste as fuel.

1989-09-01

421

Child mortality from solid-fuel use in India: a nationally-representative case-control study - article no. 491  

Energy Technology Data Exchange (ETDEWEB)

Most households in low and middle income countries, including in India, use solid fuels (coal/coke/lignite, firewood, dung, and crop residue) for cooking and heating. Such fuels increase child mortality, chiefly from acute respiratory infection. There are, however, few direct estimates of the impact of solid fuel on child mortality in India. Methods: We compared household solid fuel use in 1998 between 6790 child deaths, from all causes, in the previous year and 609 601 living children living in 1.1 million nationally-representative homes in India. Analyses were stratified by child's gender, age (neonatal, post-neonatal, 1-4 years) and colder versus warmer states. We also examined the association of solid fuel to non-fatal pneumonias. Solid fuel use was very common (87% in households with child deaths and 77% in households with living children). After adjustment for ...

2010-08-17

422

Acetylacetone in hydrogen solids: IR signatures of the enol and keto tautomers and UV induced tautomerization  

British Library Electronic Table of Contents (United Kingdom)

Acetylacetone is isolated in hydrogen matrices and is investigated by means of infrared spectroscopy, combined with theoretical calculations. The two stable enol and keto tautomers are well characterized. The keto/enol ratio in solid parahydrogen is found to be higher than in classical matrices. While vibrational bands of the enol form are broad, with bandwidths depending on the vibrational mode, those of the keto form are narrow. A KrF laser excitation is used to induce the enol/keto tautomerization in solid parahydrogen. The kinetics of the interconversion is followed, highlighting a non-direct tautomerization process.

2011-01-01

423

Preliminary Investigations of Joining Technologies for Attaching Refractory Metals to Ni-Based Superalloys  

International Nuclear Information System (INIS)

In this study, a range of joining technologies has been investigated for creating attachments between refractory metal and Ni-based superalloys. Refractory materials of interest include Mo-47%Re, T-111, and Ta-10%W. The Ni-based superalloys include Hastelloy X and MarM 247. During joining with conventional processes, these materials have potential for a range of solidification and intermetallic formation-related defects. For this study, three non-conventional joining technologies were evaluated. These included inertia welding, electro-spark deposition (ESD) welding, and magnetic pulse welding (MPW). The developed inertia welding practice closely paralleled that typically used for the refractory metals alloys. Metallographic investigations showed that forging during inertia welding occurred predominantly on the refractory metal side. It was also noted that at least some degree of forging on the Ni-based superalloy side of the joint was necessary to achieve consistent ...

2006-01-20

426

The alkali sorption process by solid sorbents at high temperature  

Energy Technology Data Exchange (ETDEWEB)

The removal of toxic metals and alkalis from gas streams at high temperatures was investigated. This is important for the development of coal-fired combined cycle power generation systems.

2000-03-01

427

Solubility of AmOHCO{sub 3} in aqueous solution under atmospheric conditions  

Energy Technology Data Exchange (ETDEWEB)

Modeling calculations on the solubility of americium have indicated that basic americium carbonate, and not americium trihydroxide, is the solubility-controlling solid in the pH range from 6 to 10 under the influence of atmospheric CO{sub 2}. The solubility of crystalline {sup 243}AmOHCO{sup 3} has been investigated in batch experiments in near-neutral and basic solutions as a function of dissolution time in 0.1 M NaClO{sup 4} at room temperature under oxic conditions. After the solutions reached steady-state conditions, the influence of dissolved solids on the americium concentration in the supernatant solution was studied by utilizing several experimental methods to separate the solution phase from the solid. The solids were characterized by X-ray powder diffraction analysis.

1987-12-01

428

Solid-state fermentation of lignocellulotic materials for the production of enzymes by the white-rot fungus Trametes hirsuta in a modular bioreactor  

British Library Electronic Table of Contents (United Kingdom)

Abstract Trametes hirsuta, a filamentous basidiomycete, was successfully cultivated in solid-state fermentation (SSF) on a mixture of pine wood chips and orange peel in a novel bioreactor that allows mixing of the inoculated solid material during the fermentation. Copper sulfate or xylidine (2,5-dimethylaniline) were added to enhance the production of enzymes, especially laccases. For comparison, Trametes hirsuta was also cultivated in submerged conditions. The effect of additives in SSF was low, whereas the choice of the solid material and the rotation of the reactor vessel showed a significant influence on the enzyme production. The space-time yields for the fermentations were calculated and showed that SSF on low-cost substrates can effectively produce extracellular enzymes at a suffici...

2011-01-01

429

SOLID STATE RESEARCH OF THE APPLIED PHYSICS ...  

Science.gov (United States)

... 10 TIN TELLURIDE Preparation of Tin Telluride Single Crystals ..... 12 ... TIN TELLURIDE Preparation of Tin Telluride Single Crystals ...

1962-07-16

430

Radiation deamination of tetracycline. [Gamma radiation  

Energy Technology Data Exchange (ETDEWEB)

The fundamental product of tetracycline hydrochlorine gamma radiolysis was separated in its solid state. From the results of spectroscopic studies it has been established that it is des-N,N-dimethylaminotetracycline.

1980-01-01

431

Physics of laser fusion. Volume IV. The future development of high-power solid-state laser systems  

Energy Technology Data Exchange (ETDEWEB)

Solid state lasers, particularly neodymium glass systems, have undergone intensive development during the last decade. In this paper, we review solid state laser technology in the context of high-peak-power systems for inertial confinement fusion. Specifically addressed are five major factors: efficiency, wavelength flexibility, average power, system complexity, and cost; these factors today limit broader application of the technology. We conclude that each of these factors can be greatly improved within current fundamental physical limits. We further conclude that the systematic development of new solid state laser madia, both vitreous and crystalline, should ultimately permit the development of wavelength-flexible, very high average power systems with overall efficiencies in the range of 10 to 20%.

1982-11-01

432

Physicochemical investigation of the behavior of elements in chloride melts in the presence of solid phases based on phosphates of polyvalent elements. II. Behavior of strontium and barium  

Energy Technology Data Exchange (ETDEWEB)

The distribution of the alkaline earth elements strontium and barium between the solid phases of phosphates of transition elements of group 4 and chloride melts was studied. The distribution coefficients of strontium and barium were found at T = 700-800/sup 0/C. Phosphates of the type NaM/sub 2//sup (IV)/(PO/sub 4/)/sub 3/, where M/sub (IV)/ represents titanium, zirconium, and hafnium, were used as the solid phases. It was established that there is an enrichment of the precipitates with the distributed components. The distribution coefficient depends on the nature of the solid phase and the temperature. It was suggested that M/sup (II)/ x M/sub 4//sup (IV)/(PO/sub 4/)/sub 6/ is formed in processes of distribution, where M/sup (II)/ represents Sr, Ba.

1987-07-01

433

Non-Markovian dephasing in solid-state single photon sources  

CERN Document Server

Solid-state single-photon sources have many desirable features that make them attractive for applications in quantum information processing. However, the phase coherence of such devices can be severely compromised by coupling to the solid-state environment. Here, we study the effects of realistic dephasing environments on a pair of solid-state single photon sources in the context of quantum interference effects such as the Hong-Ou-Mandel dip. By means of exact solutions for the non-Markovian dynamics of the sources, we show that the resulting loss of visibility depends crucially on the timing of photon detection events. Our results demonstrate that the effective visibility can be improved via temporal post-selection, and also that time-resolved interference can be a useful probe of the interaction between the emitter and its host environment.

2008-01-01

434

NASA - Waste Not  

Science.gov (United States)

Jun 4, 2004 ... On a two-year trip to Mars, according to one estimate, a crew of six humans will generate more than six tons of solid organic waste--much of ...

435

Mucinous cystadenoma of the pancreas with predominant stroma creating a solid tumor  

UK PubMed Central (United Kingdom)

BackgroundMucinous cystic neoplasm (MCN) of the pancreas is basically cystic epithelial neoplasm, unilocular or multilocular, occurring almost exclusively in women.Case...Full Text Available

436

Molten Boron Phase-Change Thermal Energy Storage ...  

Science.gov (United States)

... Advanced thermal storage systems based on very high temperature solid materials such as boron carbide or graphite have been investigated for ...

2011-06-01

437
438

Measured Temperatures of Solid Rocket Motors Dump Stored ...  

Science.gov (United States)

... TARGET SENSOR-MK 80 SERIES BOMBS ... 5-inch-, and 2.75-inch- diameter rocket motors that ... balance when compared to incoming solar radiation ...

1989-07-01

439

Kinetic behavior of solid particle in chemical-looping combustion: suppressing carbon deposition in reduction  

Energy Technology Data Exchange (ETDEWEB)

In order to apply chemical-looping combustion to a practical power plant, carbon deposition on the solid particle is one of the key problems to be overcome. Six kinds of solid particles were examined to clarify the kinetic behavior of carbon deposition. The effects of the solid composition, feed gas composition, and reaction temperature on carbon deposition were investigated by thermogravimetrical reactor on the basis of NiO/YSZ particle. From the viewpoints of both reactivity and resistance against carbon deposition, the particle of NiO mixed with YSZ (i.e., yttria-stabilized zirconia) was found to be a good candidate for chemical-looping combustion. It has been observed that carbon deposition could be completely avoided with very low concentration of water vapor. By means of a proposed model, the condition that carbon deposition would be avoided was identified. 12 refs., 8 figs., 2 tabs.

1998-03-01

440

General Disclaimer One or more of the Following Statements may ...  

Science.gov (United States)

major radius of the toroidal containment volume. The containment time was calculated using equation (4) as derived in references 16 and 17. The solid ...

443

ELECTRIC AND GALVANOMAGNETIC PROPERTIES OF ...  

Science.gov (United States)

... Abstract : The electric resistance in weak (diluted) solid solutions of the Pd-Ag and Fe-W systems, as wellAS THE Hall effect in a Pd-Ag system ...

1961-06-27

445

Crystal Chemistry of Ceramic/Mineral Systems  

Science.gov (United States)

... 1. Reeber, RR, Kusy, RP, Yu, N. and Chu, WK " Formation of a Solid Lubricant in Boron Carbide by Nitrogen Ion Implantation and Laser Annealing ...

1992-12-08

446

Compaction of dust clumps in a protostellar cloud  

Energy Technology Data Exchange (ETDEWEB)

Necessary conditions are derived for compact aggregates of solid matter to develop from loose local clumps of dust grains in a contracting protostellar cloud.

1984-01-01

447

Bacterial body plans  

UK PubMed Central (United Kingdom)

The bacterium Serratia marcescens produces a plethora of multicellular shapes of different colorations on solid substrates, allowing immediate visual detection of varieties. Such a...Full Text Available

2008-07-01

448

Aerodynamic Static Differential Pressure  

Science.gov (United States)

aerodynamic force and moment values. Only the solid and the 25 percent porous dishes were tested for the static pressure values used primarily to determine ...

450

A novel accelerated oxidative stability screening method for pharmaceutical solids  

British Library Electronic Table of Contents (United Kingdom)

Abstract Despite the fact that oxidation is the second most frequent degradation pathway for pharmaceuticals, means of evaluating the oxidative stability of pharmaceutical solids, especially effective stress testing, are still lacking. This paper describes a novel experimental method for peroxide-mediated oxidative stress testing on pharmaceutical solids. The method utilizes urea-hydrogen peroxide, a molecular complex that undergoes solid-state decomposition and releases hydrogen peroxide vapor at elevated temperatures (e.g., 30C), as a source of peroxide. The experimental setting for this method is simple, convenient, and can be operated routinely in most laboratories. The fundamental parameter of the system, that is, hydrogen peroxide vapor pressure, was determined using a modified spect...

2011-01-01

451

A Theoretical Solid Oxide Fuel Cell Model for Systems Controls and Stability Design  

Science.gov (United States)

As the aviation industry moves toward higher efficiency electrical power generation, all electric

2008-01-01

452

Treatment for dismantled radioactive solid waste from the TRIGA Mark-2 and 3  

Energy Technology Data Exchange (ETDEWEB)

Radioactive wastes are generally classified into 3 type depending on their physical property: liquid, solid and gaseous type. State-of -the art concerning liquid waste treatment has already been published; KAERI/TR-1315/99. Solid wastes classification package and treatment method will be studied to effectively manage them during the practical decommissioning work. All of the spent fuel produced during the operation of the TRIGA Mark-2 and 3 have been transported to the US last year, 1998, according to the spent fuel management strategy set-up by the US government for the non-proliferation of nuclear energy. Solid wastes are mainly all equipment existing inside of the reactors, activated concrete among the bio-shielded concrete, pipes, pimps, resin filter and it's housings, heat-exchangers, liquid waste storage tanks, to radioactive waste storage treatment facilities and so on. Solid wastes are ...

1999-06-01

453

Target R and D at JAERI  

Energy Technology Data Exchange (ETDEWEB)

We proposed a solid and a mercury target concepts through the preliminary conceptual design. To feasible these concepts, analysis and experimental works are being carried out. This paper introduces an outline of present status of target R and D such as heat transfer augmentation experiments for the solid target, mercury flow tests with a loop of maximum flow rate of 15L/min, flow pattern measurements for a cold source moderator etc. as well as preliminary conceptual design works. (author)

1999-03-01

454

Solid state NMR, basic theory and recent progress for quadrupole nuclei with half-integer spin  

International Nuclear Information System (INIS)

This review describes the basic theory and some recently developed techniques for the study of quadrupole nuclei with half integer spins in powder materials. The latter is connected to the introduction of the double rotation (DOR) by A. Samoson et al. (1) and to the introduction of the multiple quantum magic-angle spinning (MQ MAS) technique by L. Frydman et. al. (2). For integer spins, especially the solid-state deuterium magnetic resonance, we refer to the review of G.L. Hoatson and R.L. Vold: ''"2H-NMR Spectroscopy of Solids and Liquid Crystals'' (3). For single crystals we refer to O. Kanert and M. Mehring: ''Static quadrupole effects in disordered cubic solids''(4) and we would like also to mention the ''classic'' review of M.H. Cohen and F. Reif: ''Quadrupole effects in NMR studies of solids'' (5). Some more recent reviews in the field under study are D. Freude and J. Haase ''Quadrupole effects in ...

1998-12-01

455

Satellite power systems (SPS) concept definition study (Exhibit D). Solid-state amplifier investigation. Final report  

Energy Technology Data Exchange (ETDEWEB)

Data resulting from a continuing effort to provide system/subsystem definition data to aid in the evaluation of the SPS program concept is presented. The specific data described relate to the proposed use of solid state devices as microwave power amplifiers in the satellite microwave power transmission subsystem.

1981-04-01

456

Room temperature synthesis of tri-, tetrasubstituted imidazoles and bis-analogues by mercaptopropylsilica (MPS) in aqueous methanol: application to the synthesis of the drug trifenagrel  

British Library Electronic Table of Contents (United Kingdom)

The heterogeneous solid catalyst, mercaptopropylsilica (MPS), has been prepared by a modified procedure in water and its structure confirmed by solid state carbon-13 CP-MAS NMR spectrum. This catalyst has been efficiently utilized for the synthesis of a wide variety of tri-, tetrasubstituted imidazoles and their bis-analogues at room temperature. The protocol was further explored for the synthesis of the drug trifenagrel.

2010-01-01

457

Quantum theory of light interstitial diffusion and other aspects of inert gas motion in solids  

International Nuclear Information System (INIS)

Most diffusion phenomena in solids can be understood (or sometimes misunderstood) on a purely classical model. For light interstitials (hydrogen isotopes, the positive muon, and potentially He) there may be anomalous temperature dependences, and isotope effects, and anomalous response to electric fields and temperature gradients. Some of these anomalies are quantal in origin, and will be discussed. (author).

1980-03-01

458

Process for uranium processing  

International Nuclear Information System (INIS)

To the crushed ore leaching is applied. The resulting solid-liquid mixture is fed to a hydro-cyclon grading facility; here the superfine grain is separated before the concentrated mixture can be filtered or centrifuged. The grading is done in several steps. From the liquid, ultimately ridded of the solid, uranium compounds are precipitated and the yellow cake is obtained. (DG).

1984-11-12

459

Nonlinear air-coupled emission: The signature to reveal and image microdamage in solid materials  

International Nuclear Information System (INIS)

It is shown that low-frequency elastic vibrations of near-surface planar defects cause high-frequency ultrasonic radiation in surrounding air. The frequency conversion mechanism is concerned with contact nonlinearity of the defect vibrations and provides efficient generation of air-coupled higher-order ultraharmonics, ultrasubharmonics, and combination frequencies. The nonlinear air-coupled ultrasonic emission is applied for location and high-resolution imaging of damage-induced defects in a variety of solid materials.

2007-12-17

460

Municipal solid waste management in Lebanon: the need for an integrated approach  

International Nuclear Information System (INIS)

Full text.This study focuses on the management of municipal solid waste (MSW) in Lebanon. It addresses the current status of MSW management in Lebanon in terms of collection, transport and disposal, infers the associated impacts of such practices and discusses mitigation measures and finally proposes basic guidelines for a national strategy for solid waste management in the country. The study is based on available previous investigations and on a field survey of 113 villages in four different countries. The study revealed the absence of an effective environmental policy and poor collection and disposal methods throughout the country, except for the Greater Beirut Area (G A), where better solid waste management practices are employed. Although collection of MSW outside GBA was found to be acceptable by local authorities, resources (labor and equipment) were not used efficiently. Furthermore, treatment of collected waste is ...

2000-11-23

461

Microwave Combustion and Sintering Without Isostatic Pressure  

Energy Technology Data Exchange (ETDEWEB)

This investigation involves a study of the influence of key processing parameters on the heating of materials using microwave energy. Selective and localized heating characteristics of microwaves will be utilized in the sintering of ceramics without hydrostatic pressure. In addition, combustion synthesis will be studied for the production of powders, carbides, and nitrides by combining two or more solids or a solid and a gas to form new materials. The insight gained from the interaction of microwaves with various materials will be utilized in the mobilization and subsequent redeposition of uranium.

1998-10-20

462

Measurement of the susceptibility of solid "3He along the melting curve from 20 mK down to the nuclear ordering temperature  

International Nuclear Information System (INIS)

The susceptibility of solid "3He is deduced from multiple echoes observed in pulsed NMR experiments. It follows a Curie Weiss law at high temperature, increases faster than this law below 5 mK and drops abruptly around 1 mK. (Auth.).

1977-02-01

463

Limiting-dilution analysis of T cells extracted from solid human lung tissue: comparison of precursor frequencies for proliferative responses and lymphokine production between lung and blood T cells from individual donors.  

UK PubMed Central (United Kingdom)

This study evaluates the frequency and functions of immunocompetent T cells at the clonal level in solid human lung tissue versus peripheral blood. Enzymatic digestion of slices of histologically normal...Full Text Available

1988-08-01

464

Lattice parameters and thermal expansion of solid ortho-deuterium  

Energy Technology Data Exchange (ETDEWEB)

X-ray results on the lattice parameters, molar volume and thermal expansion coefficients of solid ortho-deuterium for the region from 2 K to the melting point are reported. It is found that the thermal expansion of ortho-deuterium crystals, similarly to parahydrogen is essentially anisotropic near the melting temperature. The vacancy density at the triple point is estimated. Some thermodynamic characteristics of ortho-deuterium are calculated and temperature dependences of heat capacity at constant volume, isothermal compressibility and Gruneisen constant are analyzed.

1984-01-01

465

Kinetics of achieving equilibrity at the sorption of radionuclides  

International Nuclear Information System (INIS)

Radionuclide (R) sorption from a solution (vapor) by freshly formed crystals with production of substitution solid solutions under different types of self-disordering is studied. Changes of self-defectiveness and macrodefectiveness with time and effect of radiation defects in the presence of P macroquantities are taken into account. An analysis for monodispersed sorbents is performed. It is shown that the achievement of equilibrium within a reasonable time in impurity-solid phase system depends on defectiveness which ensures a required level of the coefficient of impurity diffusion in sorbent crystals.

466

Investigation of radiation defects in solids using the EXAFS method  

International Nuclear Information System (INIS)

The exafs method is proposed as a more informative, universal one to investigate the radiation defects in solids. The successful results as obtained by the author using the synchrotron radiation source are reported for the first time. The measurements were carried out in GaAsP crystals irradiated with 50 MeV electrons.

1978-02-15

467

Interphase mass transfer in the separation of isotopes in countercurrent columns (liquid-solid systems)  

International Nuclear Information System (INIS)

The results of calculated and experimental investigation of interphase isotopic exchange efficiency in countercurrent columns are given when separation processes of isotope mixtures are taken place with use of liquid-solid systems. Effect of liquid phase flow on transfer unit height in ion exchange separation of boron, lithium, nitrogen isotopes is considered. 40 refs.; 5 figs.

468

Intermediates to ethylene glycol: carbonylation of formaldehyde catalyzed by Nafion solid perfluorosulfonic acid resin  

Energy Technology Data Exchange (ETDEWEB)

Details of a series of reactions for the production of ethylene glycol using a catalyst of Nafion solid perfluorosulfonic acid resin was detailed. The reactions included the carbonylation of formaldehyde and esterification and then hydrogenation of the product of the carbonylation, glycolic acid. Other preparations included in the work included methyl glycolate, acetylglycolic acid, methyl acetylglycolate, and methyl methoxyacetate.

1983-01-01

469

Influence of tumour volume and cell kinetics on the response of the solid Yoshida sarcoma to hyperthermia (42 degrees C).  

UK PubMed Central (United Kingdom)

The cytokinetic response of the solid Yoshida sarcoma to hyperthermia was examined at two tumour volumes, 1.0-1.5 ml and 3.0-3.5 ml. The tumour, growing on the feet of rats, was heated at 42 degrees...Full Text Available

1980-01-01

470

Formation of nano-sized particles of a solid electrolyte by laser ablation  

Energy Technology Data Exchange (ETDEWEB)

Nano-sized particles of a lithium ion conductive solid electrolyte, LiTi{sub 2}(PO{sub 4}){sub 3}, were prepared by laser ablation. The obtained particles were ca. 10nm in diameter. X-ray powder diffraction and Raman spectroscopy showed that they were amorphous with local structure similar to the crystalline counterpart. They were crystallized by the heating at ca. 630{sup o}C. (author)

2005-08-26

471

Explicit equation for particle settling velocities in solid-liquid systems  

Energy Technology Data Exchange (ETDEWEB)

Zanker has recently presented nomographs for determining particle settling velocities in solid-liquid systems. These nomographs were based on the general correlations developed by Barnea and Mizrahi and Barnea and Mednick. This work presents an equation directly computing particle settling velocities, eliminating the uncertainty associated with nomographs.

1981-11-01

472

Efficiency of selective IR multiphoton dissociation of molecules in a pulsed gas-dynamic flow interacting with a solid surface  

International Nuclear Information System (INIS)

Isotopically selective IR multiphoton dissociation of molecules (SF_6, CF_3I) in a pulsed gas-dynamic flow interacting with a solid surface was studied for the first time. A noticeable (severalfold) increase in the yield of products (compared to excitation of molecules in an unperturbed flow) without a substantial decrease in the selectivity of the process was observed. Possible reasons for the effect are discussed. (laser applications and other topics in quantum electronics)

2000-08-31

473

Basic study of solid oxide fuel cells. Part 5: investigation of fuel cell materials  

Energy Technology Data Exchange (ETDEWEB)

Solid Oxide Fuel Cell (SOFC) is expected as a new power generation source. The development of SOFC is being conducted by CRIEPI, and so far several reports of the reults were presented. This report examines materials of SOFC. For the purpose, cells were made using some of typical materials and manufacturing processes, and cell performance tests were carried out.

1991-01-01

474

Valence electronic structure of Ni in Ni-Si alloys from relative K X-ray intensity studies  

Energy Technology Data Exchange (ETDEWEB)

The K{beta}-to-K{alpha} X-ray intensity ratio of Ni in Ni{sub 3}Si, Ni{sub 2}Si and NiSi has been determined by energy dispersive X-ray fluorescence technique. It is found that the intensity ratio of Ni decreases from pure Ni to Ni{sub 2}Si and then increases from Ni{sub 2}Si to NiSi, in good agreement with the electronic structure calculations cited in the literature. We have also performed band structure calculations for pure Ni in various atomic configurations by means of linear muffin-tin orbital method and used this data with the normalized theoretical intensity ratios cited in the literature to estimate the 3d-occupation numbers of Ni in Ni-Si alloys. It is emphasized that investigation of alloying effect in terms of X-ray intensity ratios should be carried out for the stoichiometric alloys in order to make reliable and quantitative comparisons between theory and experiment in transition metal alloys.

2007-02-15

475

Upgrading low molecular weight hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

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

1989-12-12

476

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

International Nuclear Information System (INIS)

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

477

Production of unsaturated nitriles using catalysts containing boron, gallium or indium  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a process for the preparation of acrylonitrile or methacrylonitrile by the reaction of propylene or isobutylene, molecular oxygen and ammonia at a temperature of about 200/sup 0/ to 600/sup 0/C in the presence of an oxidation catalyst. The improvement consists of using as the oxidation catalyst an antimony-free catalyst having the atomic ratios described by the formula: X/sub a/A/sub b/C/sub c/Fe/sub d/Bi/sub e/Mo/sub 12/O/sub x/ wherein X is Ga, In or mixtures thereof; A is alkali metal; C is Ni, Co or mixture thereof; and wherein a is 0.01 to about 4; b is 0 to about 4; c and d are 0.01 to about 12; e is 0.01 to about 6; and x is a number sufficient to satisfy the valence requirements of the other elements present. In a process for the preparation of acrylonitrile or methacryloniotrile by the reaction of propylene or isobutylene, molecular oxygen and ammonia at a temperature of about 200/sup 0/ to 600/sup 0/C in the presence of an oxidation ...

1988-08-23

478

Mound Facility activities in chemical and physical research: July--December 1977. [Kr-Xe and Kr-Ar diffusion; Ne-Ar thermal diffusion  

Science.gov (United States)

Isotope separation of Ar, C, /sup 3/He, Kr, Ne, O, and Xe isotopes is reported. TiFeH/sub x/, TiCoH/sub x/, TiCuH/sub x/, and VH/sub x/ were studied using NMR (proton relaxation times). VD/sub x/ and VT/sub x/ were synthesized. The problem of calculating the valence state of Pu is discussed. A series solution to the plutonium (N,H) characteristic equation is suggested. Shipments of /sup 231/Pa, /sup 230/Th, and /sup 229/Th are reported. Separation and processing of /sup 234/U are also reported. Theoretical methods were developed to calculate temperature distributions as functions of water flow rate in liquid thermal diffusion columns. Diffusion coefficients were measured from 300 to 1200/sup 0/K for Kr-Xe and Kr-Ar. New thermal diffusion factors are submitted for Ne-Ar.

1978-05-01

479

Moderately heavy, heavy-fermion compound YbPd_2Si_2 at low temperatures  

International Nuclear Information System (INIS)

The available experimental data on the specific heat, magnetic susceptibility, magnetization, valence, NMR Knight shift and relaxation rate, and the quadrupolar moment of YbPd_2Si_2 are examined within the framework of the single-ion Anderson model. Such an analysis has previously given excellent agreement between theory and experiment for numerous other light heavy-fermion compounds, where crystalline fields do not play a dominant role. For YbPd_2Si_2, substantial crystalline-field splittings make difficult a quantitative comparison with existing exact solutions of the Anderson model. Inconsistencies with the interpretation that a nearly degenerate ground quadruplet determines the low-temperature thermodynamics are pointed out. It is concluded that at least three of the four Kramers doublets participate in the low-T properties. These three doublets should have a splitting of the order of the Kondo temperature, i.e., about 100 K. A simple resonant-level model ...

480

Moderately heavy, heavy-fermion compound YbPd sub 2 Si sub 2 at low temperatures  

Energy Technology Data Exchange (ETDEWEB)

The available experimental data on the specific heat, magnetic susceptibility, magnetization, valence, NMR Knight shift and relaxation rate, and the quadrupolar moment of YbPd{sub 2}Si{sub 2} are examined within the framework of the single-ion Anderson model. Such an analysis has previously given excellent agreement between theory and experiment for numerous other light heavy-fermion compounds, where crystalline fields do not play a dominant role. For YbPd{sub 2}Si{sub 2}, substantial crystalline-field splittings make difficult a quantitative comparison with existing exact solutions of the Anderson model. Inconsistencies with the interpretation that a nearly degenerate ground quadruplet determines the low-temperature thermodynamics are pointed out. It is concluded that at least three of the four Kramers doublets participate in the low-{ital T} properties. These three doublets should have a splitting of the order of the Kondo temperature, i.e., about 100 K. A simple ...

1992-07-01

481

Metallic Langmuir and Langmuir-Blodgett films based on TTF derivatives and fatty acid  

Energy Technology Data Exchange (ETDEWEB)

Recent progress in the metallic conducting Langmuir-Blodgett (LB) films built from TTF derivative and fatty acids is reported. A simple LB method of transferring the mixed Langmuir (L) film of BEDO-TTF (BO) and stearic acid (SA) onto substrates provided metallic conducting LB films. A homogeneous L film formation on the water surface observed by Brewster angle microscope (BAM) is an essential factor for the well-ordered LB films. In the L film, the carboxylate group of fatty acid forms anion layer bringing about a spontaneous formation of mixed valence state (MVS) of BO layer. Similar spontaneous formation was also found in the molecular combination of nonoxygen-substituted donor of EDT-TTF and octadecanesulfonic acid (OS). This type of reaction would be useful for obtaining conducting LB films. For the LB films of BEDO-TTF and stearic acid, we found a negative transverse magnetoresistance at low temperature that was interpreted in the weak localization of a ...

2002-12-01

482

Magnetic ordering in CeM_2Si_2 (M = Ag,Au,Pd,Rh) compounds as studied by neutron diffraction  

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 with modulated moments. The results are discussed in terms of the ...

483

Magnetic ordering in CeM/sub 2/Si/sub 2/ (M = Ag,Au,Pd,Rh) compounds as studied by neutron diffraction  

Energy Technology Data Exchange (ETDEWEB)

We report the results of neutron-diffraction experiments on CeM/sub 2/Si/sub 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/sub 2/Si/sub 2/ has an anomalously small moment (0.62..mu../sub B/) in the ordered state. CeAg/sub 2/Si/sub 2/ exhibits an incommensurate longitudinal, static magnetization wave with moment and propagation direction along the a axis. The fourth compound, CeRh/sub 2/Si/sub 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 with modulated moments. ...

1984-03-01

484

Low-temperature phase transitions and magnetic susceptibilities of low-dimensional uranium fluorides  

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.

1987-01-01

485

Linearized Schroedinger equation for nuclear quadrupole surface vibrations  

Energy Technology Data Exchange (ETDEWEB)

The Schroedinger equation for nuclear quadruple surface vibrations is linearized with the consequence that a new spin degree of freedom appears in the wave function of the linearized equation. This spin is called collective spin and has a value of 3/2. The linearized Schroedinger equation for quadrupole vibrations is used for the description of certain collective aspects of even-odd {sup 187,189,191}Ir nuclei which have a spin 3/2 in their ground state. As a potential we use the {gamma}-soft collective potential of the neighboring even-even nuclei, which is inserted into the linearized Schroedinger equation via a scalar coupling. This leads to a collective spin-dependent fine structure splitting of the energy levels governed by a collective SO(5) spin-orbit coupling and a correction to the kinetic energy. Further, we consider explicitly spin-dependent potentials which effectively describe the interaction of the valence nucleon with the core of the even-odd Ir ...

1990-07-01

486

Linearized Schroedinger equation for nuclear quadrupole surface vibrations  

International Nuclear Information System (INIS)

The Schroedinger equation for nuclear quadruple surface vibrations is linearized with the consequence that a new spin degree of freedom appears in the wave function of the linearized equation. This spin is called collective spin and has a value of 3/2. The linearized Schroedinger equation for quadrupole vibrations is used for the description of certain collective aspects of even-odd "1"8"7","1"8"9","1"9"1Ir nuclei which have a spin 3/2 in their ground state. As a potential we use the #gamma#-soft collective potential of the neighboring even-even nuclei, which is inserted into the linearized Schroedinger equation via a scalar coupling. This leads to a collective spin-dependent fine structure splitting of the energy levels governed by a collective SO(5) spin-orbit coupling and a correction to the kinetic energy. Further, we consider explicitly spin-dependent potentials which effectively describe the interaction of the valence nucleon with the core of the even-odd Ir ...

487

K{beta}-to-K{alpha} X-ray intensity ratio studies on the changes of valence electronic structures of Ti, V, Cr, and Co in their disilicide compounds  

Energy Technology Data Exchange (ETDEWEB)

K{beta}-to-K{alpha} X-ray intensity ratios of Ti, V, Cr, and Co in pure metals and their disilicide compounds have been measured following excitation by 59.54 keV {gamma}-rays from a 200 mCi {sup 241}Am point-source. The K{beta}-to-K{alpha} intensity ratios of all these metals in the disilicide compounds are found to be less than the corresponding ratios for pure metals. Comparison of the measured K{beta}-to-K{alpha} intensity ratios for the disilicides and pure metals with the multiconfiguration Dirac-Fock calculations indicates increase of the 3d electron populations of Ti, V, Cr, and Co in the disilicides from their pure metal values suggesting the rearrangement of electrons between 3d and 4s states of the individual metal atom. This rearrangement is found to be opposite to that observed in our previously reported work on NiSi{sub 2} and CuSi{sub 2}.

1999-06-01

488

K#beta#-to-K#alpha# X-ray intensity ratio studies on the changes of valence electronic structures of Ti, V, Cr, and Co in their disilicide compounds  

International Nuclear Information System (INIS)

K#beta#-to-K#alpha# X-ray intensity ratios of Ti, V, Cr, and Co in pure metals and their disilicide compounds have been measured following excitation by 59.54 keV #gamma#-rays from a 200 mCi "2"4"1Am point-source. The K#beta#-to-K#alpha# intensity ratios of all these metals in the disilicide compounds are found to be less than the corresponding ratios for pure metals. Comparison of the measured K#beta#-to-K#alpha# intensity ratios for the disilicides and pure metals with the multiconfiguration Dirac-Fock calculations indicates increase of the 3d electron populations of Ti, V, Cr, and Co in the disilicides from their pure metal values suggesting the rearrangement of electrons between 3d and 4s states of the individual metal atom. This rearrangement is found to be opposite to that observed in our previously reported work on NiSi_2 and CuSi_2.

1999-06-01

489

Influence of valency and labelling chemistry on in vivo targeting using radioiodinated HER2-binding Affibody molecules  

British Library Electronic Table of Contents (United Kingdom)

Purpose HER2 is a transmembrane tyrosine kinase, which is overexpressed in a number of carcinomas. The Affibody molecule ZHER2:342 is a small (7?kDa) affinity protein binding to HER2 with an affinity of 22?pM. The goal of this study was to evaluate the use of ((4-hydroxyphenyl)ethyl)maleimide (HPEM) for radioiodination of ZHER2:342 and to compare the targeting properties of monomeric and dimeric forms of ZHER2:342. Methods The biodistribution of different radioiodinated derivatives of ZHER2:342 was studied in BALB/C nu/nu mice bearing HER2-expressing SKOV-3 xenografts. Biodistributions of 125I-PIB-ZHER2:342 and site-specifically labelled 125I-HPEM-ZHER2:342-C were compared. Biodistributions of monomeric 131I-HPEM-ZHER2:342-C and dimeric 125I-HPEM-(ZHER2:342)2-C were evaluated using a paire...

2009-01-01

490

InP-quantum dots in Al_0_._2_0Ga_0_._8_0InP with different barrier configurations  

International Nuclear Information System (INIS)

Systematic ensemble photoluminescence studies have been performed on type-I InP-quantum dots in Al_0_._2_0Ga_0_._8_0InP barriers, emitting at approximately 1.85 eV at 5 K. The influence of different barrier configurations as well as the incorporation of additional tunnel barriers on the optical properties has been investigated. The confinement energy between the dot barrier and the surrounding barrier layers, which is the sum of the band discontinuities for the valence and the conduction bands, was chosen to be approximately 190 meV by using Al_0_._5_0Ga_0_._5_0InP. In combination with 2 nm thick AlInP tunnel barriers, the internal quantum efficiency of these barrier configurations can be increased by up to a factor of 20 at elevated temperatures with respect to quantum dots without such layers. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

2009-04-01

491

Growth of tailored sillenite photorefractives for optical correlation  

Science.gov (United States)

Photorefractives, in general, are among the most promising materials solutions to real time optical correlation. Applications include military target recognition and civilian robotic vision. Crystals of sillenite structure photorefractives, Bi12XO20, where X equals Si, Ge, or Ti, have been grown by melt techniques and in the case of bismuth silicon oxide (BSO) and bismuth titanium oxide (BTO) by the hydrothermal method of high-temperature/high-pressure solution growth. The two growth methods are discussed and crystals grown by the two methods are compared in this paper. Optical absorption and TSC studies show that hydrothermal BSO is essentially free of the native antisite Bi defect which usually acts as a donor. These studies also show that the trap density is greatly reduced in hydrothermal material. Preliminary experiments show that hydrothermal BTO crystals have improved properties over melt grown samples. Al and P act as donors and acceptors respectively and can be used to ...

1995-06-01

492

Exclusive {rho}{sup 0} electroproduction on the proton at CLAS  

Energy Technology Data Exchange (ETDEWEB)

The ep{yields}e'p{rho}{sup 0} reaction has been measured using the 5.754 GeV electron beam of Jefferson Lab and the CLAS detector. This represents the largest ever set of data for this reaction in the valence region. Integrated and differential cross-sections are presented. The W, Q{sup 2} and t dependences of the cross-section are compared to theoretical calculations based on the t-channel meson-exchange Regge theory, on the one hand, and on quark handbag diagrams related to Generalized Parton Distributions (GPDs) on the other hand. The Regge approach can describe at the {approx}30% level most of the features of the present data while the two GPD calculations that are presented in this article which succesfully reproduce the high-energy data strongly underestimate the present data. The question is then raised whether this discrepancy originates from an incomplete or inexact way of modelling the GPDs or the associated hard scattering amplitude or whether ...

2009-01-15

493

Exclusive rho^0 electroproduction on the proton at CLAS  

Energy Technology Data Exchange (ETDEWEB)

The $e p\\to e^\\prime p \\rho^0$ reaction has been measured, using the 5.754 GeV electron beam of Jefferson Lab and the CLAS detector. This represents the largest ever set of data for this reaction in the valence region. Integrated and differential cross sections are presented. The $W$, $Q^2$ and $t$ dependences of the cross section are compared to theoretical calculations based on $t$-channel meson-exchange Regge theory on the one hand and on quark handbag diagrams related to Generalized Parton Distributions (GPDs) on the other hand. The Regge approach can describe at the $\\approx$ 30% level most of the features of the present data while the two GPD calculations that are presented in this article which succesfully reproduce the high energy data strongly underestimate the present data. The question is then raised whether this discrepancy originates from an incomplete or inexact way of modelling the GPDs or the associated hard scattering amplitude or whether the ...

2009-01-01

494

Evidence for p-f mixing in U/sub 3/P/sub 4/ and U/sub 3/As/sub 4/ from optical spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

The near normal incidence reflectivity of the ferromagnets U/sub 3/P/sub 4/ and U/sub 3/As/sub 4/ and the isostructural but diamagnetic compounds Th/sub 3/P/sub 4/ and Th/sub 3/As/sub 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/sub 3/P/sub 4/ and U/sub 3/As/sub 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.

1983-07-01

495

Evidence for p-f mixing in U"3P"4 and U"3As"4 from optical spectroscopy  

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).

1983-01-01

496

Electronic, superconducting, and optical properties of technetium from its augmented-plane-wave band structure  

International Nuclear Information System (INIS)

The detailed energy-band structure of hexagonal-close-packed technetium, corresponding to the atomic configuration 4d"55s"2 of its seven outermost valence electrons, has been obtained throughout the Brillouin zone using the composite-wave variational version of the augmented-plane-wave (APW) method in conjunction with the X#alpha# (#alpha# = 0.702 99) exchange approximation for obtaining the potentials. From the band-structure data the electronic density of states (DOS) and the angular-momentum--decomposed DOS were calculated by the accurate Gilat-Raubenheimer method. These quantities were used to calculate the electron-phonon coupling constant and the transition temperature (T/sub c/) using the theories of Gaspari and Gyorffy and of McMillan. Also studied were the Fermi surface and the optical properties of Tc via the imaginary part of the interband dielectric constant for bound electrons, the latter being the first of such a study on Tc to date. The ...

497

Contrasting Kondo behavior and resonant inverse photoemission spectra of CeTSi{sub 3} and CeTGe{sub 3} (T=Rh and Ir)  

Energy Technology Data Exchange (ETDEWEB)

We have investigated CeTSi{sub 3} and CeTGe{sub 3} (T = Rh and Ir) by measuring the magnetic susceptibility, specific heat, electrical resistivity, the resonant inverse photoemission (RIPES) and M{sub IV,V} x-ray absorption spectra (XAS). The germanides showed a very weak Kondo effect, but the silicides exhibited a negatively large Weiss temperature (approx. = -130 K) and a lnT dependence of magnetic resistivity above 100 K, suggesting that they are a Kondo-lattice compound with a high Kondo temperature T{sub K} (approx. = 100 K). The Curie-Weiss law suggests that Ce atoms in these compounds remain close to 3+ down to about 150 K in spite of their high T{sub K}. In general, both RIPES and M{sub IV,V} XAS support their apparently stable valency. (author)

1999-02-28

498

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

International Nuclear Information System (INIS)

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

2009-06-01

499

Antiferromagnetic Kondo lattice: CePdSi{sub 2}  

Energy Technology Data Exchange (ETDEWEB)

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.

1997-02-01

500

"1"5"1Eu-Moessbauer study of complex magnetism in Eu_2PdSi_3: Effect of Eu"2"+ substitution by Y"3"+ and of high pressure  

International Nuclear Information System (INIS)

With "1"5"1Eu-Moessbauer spectroscopy and other methods the complex magnetic properties of Eu_2PdSi_3, arising from the two crystallographically different lattice sites of the Eu"2"+ ions, have been already studied. Here we study the impact of magnetic dilution of the magnetic Eu"2"+ sites by non-magnetic Y"3"+ ions. A previous specific heat study has found reduced magnetic ordering temperatures with strong indication of disorder effects like in magnetic spin glasses. Here we provide from "1"5"1Eu-Moessbauer spectroscopy detailed information of the impact of Y"3"+ substitution on the magnetic properties of the two lattice sites, well distinguishable in the "1"5"1Eu-spectra. Since the substitution of the larger Eu"2"+ ions by the smaller Y"3"+ ions is connected with a lattice contraction, we also applied high pressure to the Eu_2PdSi_3 sample and observed drastic changes in the magnetic properties originating from a valence transition towards Eu"3"+ for one of the ...

2010-03-01