Coulomb-U and magnetic moment collapse in δ\delta-Pu

The around-the-mean-field version of the LDA+U method is applied to investigate electron correlation effects in $\delta$-Pu. It yields a non-magnetic ground state of $\delta-$Pu, and provides a good agreement with experimental equilibrium volume, bulk modulus and explains important features of the photoelectron spectra

Pengaruh Pemberian Kombinasi Minyak Atsiri Rimpang Temulawak (Curcuma Xanthorriza Roxb.) Dan Kurkuminoidnya Terhadap Efek Analgetik Pada Mencit

Penelitian dilakukan untuk mengetahui efek analgetik dari minyak atsiri rimpang temulawak (Curcuma xanthorriza Roxb.), kurkuminoid, dan kombinasi keduanya. Penyarian kurkuminoid dilakukan dengan pelarut etil asetat dan heksan. Minyak atsiri diperoleh dari hasil destilasi air-uap. Uji analgetik dilakukan dengan metode formalin tes (20µL formalin 1%, intraplantar) terhadap mencit jantan galur Swiss (30±5g), umur 2 bulan. Kelompok uji meliputi CMC-Na 0,5 % p.o. (kontrol negatif), indometasin 4 mg/kgBB p.o. dan i.p. (kontrol positif), kurkuminoid 48 mg/kgBB p.o., minyak atsiri 24mg/kgBB p.o, serta kombinasinya p.o. Injeksi formalin dilakukan 1 jam setelah pemejanan sampel. Data licking time diambil pada fase I (menit 0-5) dan fase II (10-30menit) setelah injeksi formalin. Fase I mengindikasikan nyeri yang terjadi pada daerah susunan saraf pusat (SSP) sedangkan fase II pada daerah perifer. Hasil uji terhadap fase I menunjukkan daya analgetik indometasin p.o sebesar (4,96±3,26 %) dan i.p. (4,54±1,65%). Kurkuminoid dan minyak atsiri masing-masing (1,22±0,89%) dan (28,8±8,48%), sedangkan campuran (42,14±5,6%). Kurniawan (2007) melaporkan bahwa besarnya daya analgetik fase I pada morfin 5 mg/kgBB p.o. adalah (69,68±2,17%). Pada fase II minyak atsiri memiliki daya analgetik sebesar (74,63±1,97%), campuran minyak atsiri (24mg/kgBB) dan kurkuminoid (48 mg/kgBB) memiliki daya analgetik sebesar (67,56±0,59%), indometasin i.p. (49,46±1,08%) dan p.o (49,82±0,91%), serta kurkuminoid (44,80±1,46%)

Exact Ground States of the Periodic Anderson Model in D=3 Dimensions

We construct a class of exact ground states of three-dimensional periodic Anderson models (PAMs) -- including the conventional PAM -- on regular Bravais lattices at and above 3/4 filling, and discuss their physical properties. In general, the f electrons can have a (weak) dispersion, and the hopping and the non-local hybridization of the d and f electrons extend over the unit cell. The construction is performed in two steps. First the Hamiltonian is cast into positive semi-definite form using composite operators in combination with coupled non-linear matching conditions. This may be achieved in several ways, thus leading to solutions in different regions of the phase diagram. In a second step, a non-local product wave function in position space is constructed which allows one to identify various stability regions corresponding to insulating and conducting states. The compressibility of the insulating state is shown to diverge at the boundary of its stability regime. The metallic phase is a non-Fermi liquid with one dispersing and one flat band. This state is also an exact ground state of the conventional PAM and has the following properties: (i) it is non-magnetic with spin-spin correlations disappearing in the thermodynamic limit, (ii) density-density correlations are short-ranged, and (iii) the momentum distributions of the interacting electrons are analytic functions, i.e., have no discontinuities even in their derivatives. The stability regions of the ground states extend through a large region of parameter space, e.g., from weak to strong on-site interaction U. Exact itinerant, ferromagnetic ground states are found at and below 1/4 filling.Comment: 47 pages, 10 eps figure

Exotic ground states and impurities in multiband superconductors

We consider the effect of isotropic impurity scattering on the exotic superconducting states that arise from the usual BCS mechanism in substances of cubic and hexagonal symmetry where the Fermi surface contains inequivalent but degenerate pockets (e.g. around several points of high symmetry). As examples we look at CeCo$_2$, CeRu$_2$, and LaB$_6$; all of which have such Fermi surface topologies and the former exhibits unconventional superconducting behavior. We find that while these non s-wave states are suppressed by non-magnetic impurities, the suppression is much weaker than would be expected for unconventional superconductors with isotropic non-magnetic impurity scattering.Comment: 4 pages, no figure

Direct experimental verification of applicability of single-site model for angle integrated photoemission of small TKT_{K} concentrated Ce compounds

Bulk-sensitive high-resolution Ce 4f spectra have been obtained from 3d $\to$ 4f resonance photoemission measurements on La$_{1-x}$Ce$_x$Al$_2$ and La$_{1-x}$Ce$_x$Ru$_2$ for $x = 0.0, 0.04, 1.0$. The 4f spectra of low-Kondo-temperature ($T_{K}$) (La,Ce)Al$_2$ are essentially identical except for a slight increase of the Kondo peak with $x$, which is consistent with a known increase of $T_{K}$ with $x$. In contrast, the 4f spectra of high-$T_{K}$ (La,Ce)Ru$_2$ show a Kondo-like peak and also a 0.5 eV structure which increases strongly with $x$. The resonance photon-energy dependences of the two contributions are different and the origin of the 0.5 eV structure is still uncertain.Comment: submitted to SCES 2001, two-columnn format, modified tex

Data Services for Long Tail Science at the Integrated Earth Data Applications (IEDA) Data Facility

IEDA (Integrated Earth Data Applications) is a US-based data facility funded through a contract with the US National Science Foundation to operate data systems and data services for solid earth geoscience data. IEDA has developed a comprehensive suite of data services that are designed to address the concerns and needs of investigators, especially researchers working in the 'Long Tail of Science' (Heidorn 2008). IEDA provides a data publication service, registering datasets with DOI to ensure their proper citation and attribution. IEDA works with publishers on advanced linkages between datasets in the IEDA repository and scientific online articles to facilitate access to the data, enhance their visibility, and augment their use and citation. IEDA also developed a comprehensive investigator support that includes tools, tutorials, and virtual or face-to-face workshops that guide and assist investigators with data management planning, data submission, and data documentation. A critical aspect of IEDA's concept has been the disciplinary expertise within the team and its strong liaison with the science community, as well as a community-based governance. These have been fundamental to gain the trust and support of the scientists and have lead to significantly improved data preservation and access in the communities served by IEDA