bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Early Review of the Performance Assessment in the Draft Compliance Certification Application for the Waste Isolation Pilot Plant
Authors: Lee William W.-L. 
Published: April 2011

AbstractOn March 31, 1995, tlhe IT. S. Department of Energy filed a draft application for certification of compliance with I the U. S. Environmental Protection Agency (USEPA) to show the Waste Isolation Pilot Plant's compliance with the USEPA's environmental standards, making the application the first of its kind. Demonstration of compliance is by performance assessment. This paper is an early review of the performance assessment in the draft application, by the Environmental Evaluation Group, an oversight group. The performance assessment in the draft application is incomplete. Not all relevant scenarios have been analyzed. The calculation of potential consequences often does not use experimental data but rather estimates by workers developing additional data. The final compliance application, scheduled for October 1996. needs to consider additional scenarios, and be fully based on experimental data.
Uncertainties in Nuclide Releases for a High-Level Waste Repository Backfill With Smectite Illitization
Authors: Hatano Y. , Hatano N. , Suzuki A. 
Published: April 2011

AbstractUncertainties in nuclide release calculations, based on the uncertainty in illitization rate for smectite backfill have been studied. This paper has three new features: (i) an analytical solution with temporal parameter changes, (ii) uncertainty study with respect to the rate of temporal changes, and (iii) using various data of illitization.We show the following in this paper: (1) The uncertainty in nuclide releases is enhanced greatly in the case where the illitization period coincides with the transition time from solubility-limit source to exponentially decaying source; (2) The uncertainty in the retardation factor may have been overestimated in previous static analyses, leading to conclusions that the illitization problem is more vexing than it really is.
Scientific Basis for Storage Criteria for Interim Dry Storage of Aluminum-clad Fuels
Authors: Sindelar R. L. , Peacock H. B. , Lam P. S. , Iyer N. C. , Louthan M. R. , Murphy J. R. 
Published: April 2011

AbstractAn engineered system for dry storage of aluminum-clad foreign and domestic research reactor spent fuel owned by the United States Department of Energy is being considered to store the fuel up to a nominal period of 40 years prior to ultimate disposition. Scientifically-based criteria for environmental limits to drying and storing the fuels for this system are being developed to avoid excessive degradation in sealed and non-sealed (open to air) dry storage systems. These limits are based on consideration of degradation modes that can cause loss of net section of the cladding, embrittlement of the cladding, distortion of the fuel, or release of fuel and fission products from the fuel/clad system. Potential degradation mechanisms include corrosion mechanisms from exposure to air and/or sources of humidity, hydrogen blistering of the aluminum cladding, distortion of the fuel due to creep, and interdiffusion of the fuel and fission products with the cladding.The aluminum-clad research reactor fuels are predominantly highly-enriched aluminumuranium alloy fuel which is clad with aluminum alloys similar to 1100, 5052, and 6061 aluminum. In the absence of corrodant species, degradation due to creep and diffusion mechanisms limit the maximum fuel storage temperature to 200°C. The results of laboratoryscale corrosion tests indicate that this fuel could be stored under air up to 200°C at low relative humidity levels (< 20%) to limit corrosion of the cladding and fuel (exposed to the storage environment through assumed pre-existing pits in the cladding). Excessive degradation of fuels with uranium metal up to 200°C can be avoided if the fuel is sufficiently dried and contained in a sealed system; open storage can be achieved if the temperature is controlled to avoid excessive corrosion even in dry air.
Design and Synthesis of Novel Side-Chain Polyquinolines and Polyimides for Second-Order Nonlinear Optics
Authors: Jen A. K-Y. , Chen T.-A. , Cai Y.-M. 
Published: April 2011

ABSTRACTNovel approaches to second-order nonlinear optical (NLO) side-chain polyquinolines and polyimides are described. The syntheses and the characterization of the polymers are detailed. The electro-optical coefficients (r33), temporal stability of dipole alignment, and other physical properties of the NLO polymers are presented.
Thermally Stable Polyimides for Second-Order Nonlinear Optics
Authors: Chen J. I. , Li L. , Marturunkakul S. , Kumar J. , Tripathy S. K. , Lindsay G. A. , Miller R. D. 
Published: April 2011

ABSTRACTA new class of nonlinear optical (NLO) polyimides incorporating a thermally stable chromophore has been synthesized and characterized. These polymers exhibit large and extremely
Contributions of Low-Lying Excited States to Optical Nonlinearities in Squaraines
Authors: Singer K. D. , Andrews J. H. , Khaydarov J. D. V. , Hull D. L. , Chuang K. C. 
Published: April 2011

ABSTRACTWe measured the third-harmonic spectrum for a series of both centrosymmetric and noncentrosymmetric squaraine dyes in chloroform. By fitting the experimental dispersion of the third order susceptibility, γ, to a four-level sum-over-states model, we determined the strength and location of the lowest lying two-photon-like transition. In each case, we find that the lowest two-photon-like state appears just above the dominant linear absorption peak in energy and that the transition moment to that state makes a significant contribution to the nonlinearity, as do transition moments to one or more higher-lying two-photon-like states in the ultraviolet. The spectra of one centrosymmetric dye contains an additional feature evidencing a nonzero dipole moment difference between the ground and first excited state dipole moments (δμ) that we attribute to a conformational asymmetry. A noncentrosymmetric squaraine dye shows a similar feature, which, as expected, arises from its δμ. Effects of symmetry breaking are described.
Polymer Integrated Optic Zero-Gap Directional Coupler
Authors: Grote J. G. 
Published: April 2011

ABSTRACTIntegrated optic zero-gap directional couplers (ZGDC‘s) offer orders of magnitude shorter device lengths than conventional directional couplers. Researchers are currently striving to simultaneously optimize several properties of nonlinear optical (NLO) polymers that are viewed essential for the fabrication of commercially viable polymer electro-optic devices, including high electro-optic activity, low propagation loss and high temperature poling retention. Fabrication of zero-gap directional couplers using NLO polymers show the potential to realize devices with interaction lengths as short as 100 μm, operating at TFL level switching voltages. Hence, NLO polymer ZGDC‘s will possess the ability to tolerate large propagation losses. This can allow the low propagation loss constraint for NLO materials to be relaxed significantly. Polymers with high electro-optic activity that might be rejected because of high propagation loss, could potentially be utilized for ZGDC switches. In addition, by using these devices as stand alone switches for the present (i.e., not integrating them with electronic circuits) the de-poling temperature constraint can also be significantly relaxed since neither solder baths nor high density interconnect (HDI) processes will be needed. These relaxed constraints should improve the chances for introduction of viable NLO polymer devices that can compete in the market place today, without being forced to wait for a material in which all properties have been optimized.
A Molecular Architectural Approach to Self-Assembled Monolayers as NLO Materials
Authors: Yang Xiaoguang , Smilowitz Laura , Buscher C. Thomas , McBranch Duncan , Robinson Jeanne , Li DeQuan 
Published: April 2011

ABSTRACTSelf-assembled molecular architechtures of nonlinear optical (NLO) chromophores and their super-chromophores are discussed. The chromophores are derivatives of azobenzene sulfonates and the super chromophores are derivatives of calix[4]stilbazole and calix[4]stilbazolium. The studies of azobenzene sulfonates are aimed at understanding the surface coverage and molecular orientation in polar self-assembled monolayers (SAMs). The optimized molecular orientation was found to be 32±3 degree and the maximum surface coverage is approximately 2–4 molecules per nm2 depending on the molecular cross-section. The calixarene chromophores are macrocyclic compounds consisting of four simple D-π-A units bridged by methylene groups. These molecules were synthesized such that four D-π-A units of the calix[4]arene were aligned along the same direction with the calixarene in a cone conformation. Both simple and super-chromophores were subsequently fabricated into covalently bound selfassembled monolayers on the surfaces of fused silica and silicon. Spectroscopic second harmonic generation (SHG) measurements were carried out to determine the absolute value of the dominant element of the second-order nonlinear susceptibility, d33 = 60 pm/V at a fundamental wavelength of 890 nm. Furthermore, SHG imaging was employed to investigate the pattemed SAMs of NLO super chromophores.
Novel Piezoelectric Polyimides
Authors: Simpson Joycelyn O. , Welch Sharon S. , St.Clair Terry L. 
Published: April 2011

ABSTRACTThis research focuses on the synthesis, processing, and characterization of novel high performance piezoelectric polymers. A series of polyimides containing pendant, polar trifluoro (-CF 3) and nitrile (-CN) groups have been synthesized, electroded and poled. Measurements of the piezoelectric sensor response are presented to demonstrate the relationship between dipole concentration and the level of piezoelectricity for these materials. An understanding of the effect of dipole concentration on piezoelectric properties will enable the molecular design of polymers possessing distinct improvements over state of the art piezoelectric polymers including enhanced polarizability, polarization stability at elevated temperatures, and increased mechanical integrity.
Electrical Communication Between Glucose Oxidase and Different Ferrocenylalkanethiol Chain Lengths
Authors: Rubin Shai , Bar Georg , Cutts Russell W. , Chow Jimmy T. , Ferraris John P. , Zawodzinski Thomas A. 
Published: April 2011

ABSTRACTWe describe the factors affecting the electron transfer process between the different components of a self-assembled mixed monolayer. The system is comprised of mixed monolayers containing aminoalkanethiols (AMATs) and ferrocenylalkanethiols (FATs) of variable chain lengths. We study the effects of different ratio of the two mixed monolayer components on the permeability of the monolayer towards a Ru(NH3)6C13 redox probe. In order to study the electrical communication between the enzyme and the mediator molecules, the enzyme glucose oxidase (GOx) was attached to the AMAT sites to create a biosensor device. The relative efficiency of a biosensor of each chain-length combination of FAT and AMAT was examined. In light of this comparison, we consider the critical factors for efficient electron transfer between the ferrocene mediator and the GOx redox active site immobilized as part of the surface-confined system. We find that the biosensor response is greatest when the enzyme and the FATs are attached to the surface with different alkane chain lengths. We also find strong evidence for the existence of domains of FAT and AMAT in the mixed monolayer system.
Photoluminescence and Electroluminescence Quenching in 8-Hydroxyquinoline Aluminum Chelates
Authors: Zhang Xian-man , Higginson Keith A. , Papadimitrakopoulos Fotios 
Published: April 2011

ABSTRACTThe present communication proposes a mechanism for photoluminescence (PL) and electroluminescence (EL) quenching in aluminum(III) 8-hydroxyquinoline (Alq3) chelates. Our experiments indicate that in the presence of moisture, ligand exchange of 8-hydroxyquinoline with water can occur. At elevated temperatures, the liberated 8-hydroxyquinoline undergoes a condensation reaction in the presence of traces of oxygen, generating a dark, non-emissive polymeric compound. Spectroscopic and electrochemical methods were used to determine the band gap and energy levels (highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO)) of this byproduct. Steady state PL experiments indicate that (0.5 to 1%) concentration of this byproduct, evenly dispersed in Alq3 films, results in dramatic PL quenching. Deliberate insertion of an approximately 50 Å thick film of this byproduct into the interface of a poly(p-phenylenevinylene)/Alq3 light emitting diode (LED) completely quenches the EL as well. Initial data suggest an energy transfer quenching mechanism.
Poly(3-Alkyl-Co-3,4-Dialkyltfiophfene) Copolymers: A Series of Conjugated Materials with Tunable Energy-Gap
Authors: Catellani M. , Luzzati S. , Botta C. , Stein P. C. 
Published: April 2011

ABSTRACTThe copolymerization of 3-alkylthiophene and 3,4-dialkylthiophene units in well defined ratios leads to materials in which it is possible to modulate continuously the electronic properties such as the conjugation length and the energy-gap. The soluble materials have optical properties depending on the chemical composition of the chain. A macromolecular and optical characterisation has been performed on two copolymer series.
2,2'-Spaced-Dipyrroles: Electronic and Steric Effects of the Spacers on Bandgaps and Conductivities of the Corresponding Polymers
Authors: Berlin A. , Canavesi A. , Pagani G. , Schiavon G. , Zecchin S. , Zotti G. 
Published: April 2011

ABSTRACTConjugated, conducting pyrrole-based polymers were obtained by electropolymerization of 2,2′-spaced-dipyrroles in which the spacer was a vinylene, or a cyanovinylene, or an azo group. In every case, the bandgap of the polymers is considerably narrower than that of polypyrrole.
Solvent, LICL, and Temperature Effects on the Morphological Structure and Electronic Properties of Polyaniline
Authors: Angelopoulos Marie , Liao Yun-Hsin , Furman Bruce , Graham Teresita 
Published: April 2011

ABSTRACTExtensive gel permeation chromatography coupled with surface structure measurements clearly indicate that polyaniline (pani) base has a tendency to aggregate as a result of interchain hydrogen-bonding. The aggregation is present in the solid state powder; the extent of aggregation is found to be significantly dependent on the synthetic conditions. Pani base powders having a high degree of aggregation have significantly reduced solubility. The degree of aggregation of pani base in solution is found to be dependent on the solvent, concentration, and temperature. As the solvent becomes a better solvent for the base material, the less aggregated is the structure. Solvents which can strongly interact with the polymer disrupt the aggregation. In addition, salts such as LiCl which complex the polymer via a “pseudo-doping” process, also disrupt the internal pani hydrogen-bonding and deaggregate the polymer. As the polymer is deaggregated to different levels by a solvent or by LiCl, the individual chains can better be solvated and thus a conformational change also occurs. The chains adapt a more expanded coil type of conformation. The degree of expansion depends on the solvation power of the solvent. As the level of deaggregation and subsequent chain expansion increases, a significant red shift is observed in the λmaximum of the exciton absorbance and the surface structure of the polymer becomes smoother. It is found that the LiCl induced morphological changes results in increased conductivity upon doping pani base with a protonic acid.
Superconductivity and Magnetism in C60 “Polymer”
Authors: Grigoryan L. S. , Tokumoto M. 
Published: April 2011

ABSTRACTA new aggregated form of C60, believed to be “polymer”, was prepared through the reaction of C60 with iodine. First, C60 was reacted with iodine to give iodine-doped C60 with magnetic transition around 60 K. After removal of the doped iodine, the sample showed some of the characteristic properties common to the other “polymer” forms of C60. Finally, this “polymer” sample was found to show superconductivity after doping with various alkali-metals (K, Rb, Rb/Cs). Magnetic and/or superconducting properties of these C60 “polymer” are compared with monomer C60
An Investigation into the Role of Incorporated Solvent (EtOH/H2O) Molecules on the Structure of Group 2 Metal bis(β- Diketonate) Complexes: Ramifications for CVD Precursors of Electronic Materials.
Authors: Otway David J. , Luten Henry A. , Malik K. M. Abdul , Hursthouse Michael B. , Rees William S. 
Published: April 2011

ABSTRACTThe synthesis and characterization of thermally stable, volatile, group 2 element-containing complexes is an important prerequisite for the subsequent use of these compounds in chemical vapor deposition (CVD) of superconducting metal oxides (SMO) and other electronic materials, e.g., YBa2Cu3O7-δ. and CaGa2S4:Ce. The utilization of group 2 metal ethoxide compounds {[M(OEt)2(EtOH)4]n (where M = Ca, Sr or Ba)) as precursors to additional complexes is discussed. For example, the compounds [M(tmhd)(OEt)(EtOH)]n (Htmhd = 2,2,6,6- tetramethylheptane-3,5-dione) may be obtained by reacting one equivalent of Htmhd with the metal bis(ethoxide), and these also may be reacted further with functionalized alcohols, or a second β–diketone, to form heteroleptic compounds. Additionally, the preparation and characterization of some Lewis base adducted complexes have been examined with an emphasis on the role that water plays in their isolation.
Zinc Bis(Amide) Compounds Evaluated as Designed Precursors for Site-Selective P-type Doping of ZnSe
Authors: Gaul David A. , Just Oliver , Rees William S. 
Published: April 2011

ABSTRACTZinc selenide doped with nitrogen deposited by organometallic vapor phase epitaxy (OMVPE) is one example which leads to a material that produces a blue emission. However, the effective incorporation of the nitrogen dopant into the zinc selenide lattice has not yet resulted in the demanded efficiency. One potential solution involves the design of a precursor introducing the nitrogen dopant bonded to zinc that survives the thermal decomposition process. Several new zinc bis(amide) compounds with the general formula Zn[N(R)(R′)]2 have been synthesized. Investigations into the thermal decomposition mechanisms of these compounds have provided insight into the potential usefulness of the designed precursor in the preparation of ZnSe:N.
MOCVD HTSC Precursor Delivery Monitored By UV Spectroscopy
Authors: Rappoli Brian J. , DeSisto William J. 
Published: April 2011

ABSTRACTUV spectroscopy has been used as an in situ diagnostic to measure the gas phase concentration of 2,2,6,6-tetramethyl-3,5-heptanedionate (thd) complexes of Ba, Cu and Y in metalorganic chemical vapor deposition (MOCVD) bubbler effluent. These precursors for MOCVD synthesis of YBa2Cu37−δ (YBCO) show marked instability in gas phase concentration as a function of time during bubbler purge. The UV diagnostic technique has been applied to both a small scale test system and a commercial scale MOCVD reactor.
Boundary Layer Temperature Profile in Diamond CVD System Using Laser-Induced Fluorescence
Authors: Wang Qingyu , Lindsay Jon L. , Hofeldt David L. 
Published: April 2011

ABSTRACTThe gas temperature of a radio-frequency thermal plasma has been measured by laser-induced fluorescence along the axis of the plasma jet near the substrate surface. The temperature was determined from the rotational population distribution of OH radicals. From the measured temperature profile, the freestream temperature was found to be about 3400 K and the boundary layer thickness was determined to be about 1 mm. A numerical model including carbonhydrogen- argon kinetics was used to predict species concentrations near the surface of the substrate. The results indicate that all CHa radical concentrations increase with freestream temperature for temperatures between 2500-4000 K. Of the C1 radicals, methyl has the highest concentration in this range in our system, which is consistent with other reports that methyl is an important diamond growth species.
A Grain Boundary Defect in Polycrystalline Films
Authors: Rutledge K. M. McNamara , Watkins G. D. , Zhou X. 
Published: April 2011

ABSTRACTOur studies primarily concern an S=1/2 electron paramagnetic resonance (EPR) at g=2.0028 with a pair of weaker partially resolved satellites that has been observed in polycrystalline diamond grown by chemical vapor deposition (CVD). These satellites can be shown to result from the forbidden Δm=±l nuclear spin flips of hydrogen during the EPR ΔM∼ 2Å away from the unpaired electron spin. It is suggested that hydrogen enters a vacancy-like stretched bond at a grain boundary, allowing the carbons to relax backward, one bonding to the hydrogen, the other with an unpaired electron in its dangling bond.
Influence Of Surface Terminating Species On Electron Emission From Diamond Surfaces
Authors: Thomas R. E. , Humphreys T. P. , Pettenkofer C. , Malta D. P. , Posthill J. B. , Mantini M. J. , Rudder R. A. , Hudson G. C. , Markunas R. J. 
Published: April 2011

ABSTRACTChanges in electron affinity on the C(001) surface of type Ifb diamonds have been studied using a variety of surface analytical techniques, including ultraviolet photoemission spectroscopy, secondary electron emission spectroscopy and constant initial states photoemission. Following H-plasma exposure, an intense low-energy emission peak was observed with all spectroscopies. The emission intensity associated with the chemisorbed hydrogen was found to be a linear function of surface hydrogen coverage. The proposed mechanism for the hydrogen induced changes in electron affinity is the creation of a dipole on the surface by the addition of hydrogen which opposes the surface potential of the bare surface. A total change in electron affinity of 2.2 eV was measured upon hydrogen termination of the clean 2x1 surface. Constant initial states photoemission demonstrates that the intense low-energy electron emission observed arises from electrons emitted from bulk states at the conduction band edge. Oxygen, as an electronegative species, was found to have the opposite effect and the electron affinity was increased by ∼3.7 eV upon oxygen termination relative to the clean 2x I surface.
Atomic and Electronic Structures of Grain Boundary in Chemical Vapor Deposited Diamond Thin Film
Authors: Zhang Y. , Ichinose H. , Ishida Y. , Ito K. , Nakanose M. 
Published: April 2011

ABSTRACTHigh resolution electron microscopy and electron energy-loss spectrometry were used to investigate both atomic and electronic structures of grain boundaries in diamond thin films grown by chemical vapor deposition. The atomic structures of {112}σ3 and {114}σ9 <110= tilt boundaries in diamond show different features from those in other diamond structure semiconductors. The electron energy-loss spectra recorded from the grain boundary regions show extra intensity near the energy-loss corresponding to carbon 1s-to-π*; transition, as compared to the spectra recorded from neighboring crystalline regions. This gives the evidence that the dangling bonds are not fully reconstructed along <110= direction in the boundary structure. Atomic models are constructed for these boundaries with the presence of non-tetracoordinated atoms. The stability of the boundary structure is explained by the π-like bonding between the nontetracoordinated atoms.