Data management study, volume 5. Appendix A - Contractor data package technical description and system engineering /SE/ Final report

Technical description and systems engineering contractor data package for Voyager spacecraf

{2,6-Bis[(2,6-diphenyl­phosphan­yl)­oxy]-4-fluoro­phenyl-κ3 P,C 1,P′}(6-methyl-2,2,4-trioxo-3,4-dihydro-1,2,3-oxathia­zin-3-ido-κN)palladium(II)

The title acesulfamate complex, [Pd(C30H22FO2P2)(C4H4NO4S)], contains a four-coordinate Pd(II) ion with the expected, although relatively distorted, square-planar geometry where the four L—Pd—L angles range from 79.58 (8) to 102.47 (7)°. The acesulfamate ligand is N-bound to Pd [Pd—N = 2.127 (2) Å] with a dihedral angle of 76.35 (6)° relative to the square plane. Relatively long phen­yl–acesulfamate C—H⋯O and phen­yl–fluorine C—H⋯F inter­actions consolidate the crystal packing

Order and nFl Behavior in UCu4Pd

We have studied the role of disorder in the non-Fermi liquid system UCu4Pd using annealing as a control parameter. Measurement of the lattice parameter indicates that this procedure increases the crystallographic order by rearranging the Pd atoms from the 16e to the 4c sites. We find that the low temperature properties depend strongly on annealing. Whereas the non-Fermi liquid behavior in the specific heat can be observed over a larger temperature range after annealing, the clear non-Fermi liquid behavior of the resistivity of the unannealed sample below 10 K disappears. We come to the conclusion that this argues against the Kondo disorder model as an explanation for the non-Fermi liquid properties of both as-prepared and annealed UCu4Pd

A Bayesian approach to correct for unmeasured or semi-unmeasured confounding in survival data using multiple validation data sets

Purpose: The existence of unmeasured confounding can clearly undermine the validity of an observational study. Methods of conducting sensitivity analyses to evaluate the impact of unmeasured confounding are well established. However, application of such methods to survival data (“time-to-event” outcomes) have received little attention in the literature. The purpose of this study is to propose a novel Bayesian method to account for unmeasured confounding for survival data.   Methods: The Bayesian method is proposed under an assumption that the supplementary information on unmeasured confounding in the form of internal validation data, external validation data or expert elicited prior distributions is available. The method for incorporating such information to Cox proportional hazard model is described.  Simulation studies are performed based on the recently published instrumental variable method to assess the impact of unmeasured confounding and to illustrate the improvement of the proposed method over the naïve model which ignores unmeasured confounding.   Results: Simulation studies illustrate the impact of ignoring the unmeasured confounding and the effectiveness of our Bayesian approach. The corrected model had significantly less bias and coverage of 95% intervals much closer to nominal.   Conclusion: The proposed Bayesian method provides a useful and flexible tool in incorporating different types of supplemental information on unmeasured confounding to adjust the treatment estimates when the outcome is survival data.  It out-performed the naïve model in simulation studies based on a real world study. &nbsp

Knight Shift Anomalies in Heavy Electron Materials

We calculate non-linear Knight Shift $K$ vs. susceptibility $\chi$ anomalies for Ce ions possessing local moments in metals. The ions are modeled with the Anderson Hamiltonian and studied within the non-crossing approximation (NCA). The $K-vs.- \chi$ non-linearity diminishes with decreasing Kondo temperature $T_0$ and nuclear spin- local moment separation. Treating the Ce ions as an incoherent array in CeSn$_3$, we find excellent agreement with the observed Sn $K(T)$ data.Comment: 4 pages, Revtex, 3 figures available upon request from [email protected]

Calculations of the Knight Shift Anomalies in Heavy Electron Materials

We have studied the Knight shift $K(\vec r, T)$ and magnetic susceptibility $\chi(T)$ of heavy electron materials, modeled by the infinite U Anderson model with the NCA method. A systematic study of $K(\vec r, T)$ and $\chi(T)$ for different Kondo temperatures $T_0$ (which depends on the hybridization width $\Gamma$) shows a low temperature anomaly (nonlinear relation between $K$ and $\chi$) which increases as the Kondo temperature $T_0$ and distance $r$ increase. We carried out an incoherent lattice sum by adding the $K(\vec r)$ of a few hundred shells of rare earth atoms around a nucleus and compare the numerically calculated results with the experimental results. For CeSn_3, which is a concentrated heavy electron material, both the ^{119}Sn NMR Knight shift and positive muon Knight shift are studied. Also, lattice coherence effects by conduction electron scattering at every rare earth site are included using the average-T matrix approximation. Also NMR Knight shifts for YbCuAl and the proposed quadrupolar Kondo alloy Y_{0.8}U_{0.2}Pd_{3} are studied.Comment: 31 pages of RevTex, 22 Postscript figures, submmitted to PRB, some figures are delete

Theory of One-Channel vs. Multi-Channel Kondo Effects for Ce3+^{3+} Impurities

We introduce a model for Ce$^{3+}$ impurities in cubic metals which exhibits competition between the Fermi-liquid fixed point of the single channel Kondo model and the non-Fermi-liquid fixed point of the two- and three-channel Kondo models. Using the non-crossing approximation and scaling theory, we find: (i) A possible three-channel Kondo effect between the one- and two-channel regimes in parameter space. (ii) The sign of the thermopower is a fixed point diagnostic. (iii) Our results will likely survive the introduction of additional $f^2$ and conduction states. We apply this model to interpret the non-Fermi liquid alloy La$_{1-x}$Ce$_x$Cu$_{2.2}$Si$_2$.Comment: 13 pages, Revtex, To appear in Phys. Rev. Let

Non-Fermi Liquid Behavior in Dilute Quadrupolar System Prx_{x}La1−x_{1-x}Pb3_3 with xx≤\le0.05

We have studied the low-temperature properties of Pr$_{x}$La$_{1-x}$Pb$_{3}$ with non-Kramers $\Gamma_{3}$ quadrupolar moments of the crystal-electric-field ground state, for a wide concentration range of Pr ions. For $x$$\le$0.05, the specific heat $C/T$ increases monotonically below $T$=1.5 K, which can be scaled with a characteristic temperature $T^{*}$ defined at each concentration $x$. The electrical resistivity $\rho$$(T)$ in the corresponding temperature region shows a marked decrease deviating from a Fermi-liquid behavior $\rho$$(T)$$\propto$$T^{2}$. The Kondo effect arising from the correlation between the dilute $\Gamma_{3}$ moments and the conduction electrons may give rise to such anomalous behavior

Spinless Two-Band Model in Infinite Dimensions

A spinless two-band model is studied in infinite dimension limit. Starting from the atomic limit, the formal exact solution of the model is obtained by means a perturbative treatment of the hopping and hybridisation terms. The model is solved in closed form in high dimensions assuming no local spin fluctuations. The non-Fermi liquid properties appearing in the metallic phase are analysed through the behaviour of the density of states and the self-energy near the Fermi level.Comment: 4 pages, 3 figures, to appear in PRB-Breif Repor