Comparison of techniques for computing shell-model effective operators

Different techniques for calculating effective operators within the framework of the shell model using the same effective interaction and the same excitation spaces are presented. Starting with the large-basis no-core approach, we compare the time-honored perturbation-expansion approach and a model-space truncation approach. Results for the electric quadrupole and magnetic dipole operators are presented for $^6$Li. The convergence trends and dependence of the effective operators on differing excitation spaces and Pauli Q-operators is studied. In addition, the dependence of the electric-quadrupole effective charge on the harmonic-oscillator frequency and the mass number, for A=5,6, is investigated in the model-space truncation approach.Comment: 18 pages. REVTEX. 4 PostScript figure

Transition Rates between Mixed Symmetry States: First Measurement in 94Mo

The nucleus 94Mo was investigated using a powerful combination of gamma-singles photon scattering experiments and gamma-gamma-coincidence studies following the beta-decay of 94mTc. The data survey short-lived J^pi=1+,2+ states and include branching ratios, E2/M1 mixing ratios, lifetimes, and transition strengths. The mixed-symmetry (MS) 1+ scissors mode and the 2+ MS state are identified from M1 strengths. A gamma transition between MS states was observed and its rate was measured. Nine M1 and E2 strengths involving MS states agree with the O(6) limit of the interacting boson model-2 using the proton boson E2 charge as the only free parameter.Comment: 9 pages, 3 PostScript figures included, ReVTeX, accepted for publication in Physical Review Letters, tentatively scheduled for August 9, 199

Crystallinity Effects in Sequentially Processed and Blend-Cast Bulk-Heterojunction Polymer/Fullerene Photovoltaics

Although most polymer/fullerene-based solar cells are cast from a blend of the components in solution, it is also possible to sequentially process the polymer and fullerene layers from quasi-orthogonal solvents. Sequential processing (SqP) not only produces photovoltaic devices with efficiencies comparable to the more traditional bulk heterojunction (BHJ) solar cells produced by blend casting (BC) but also offers the advantage that the polymer and fullerene layers can be optimized separately. In this paper, we explore the morphology produced when sequentially processing polymer/fullerene solar cells and compare it to the BC morphology. We find that increasing polymer regioregularity leads to the opposite effect in SqP and BC BHJ solar cells. We start by constructing a series of SqP and BC solar cells using different types of poly(3-hexylthiophene) (P3HT) that vary in regioregulary and polydispersity combined with [6,6]-phenyl-C61-butyric-acid-methyl-ester (PCBM). We use grazing incidence wide-angle X-ray scattering to demonstrate how strongly changes in the P3HT and PCBM crystallinity upon thermal annealing of SqP and BC BHJ films depend on polymer regioregularity. For SqP devices, low regioregularity P3HT films that possess more amorphous regions allow for more PCBM crystallite growth and thus show better photovoltaic device efficiency. On the other hand, highly regioregular P3HT leads to a more favorable morphology and better device efficiency for BC BHJ films. Comparing the photovoltaic performance and structural characterization indicates that the mechanisms controlling morphology in the active layers are fundamentally different for BHJs formed via SqP and BC. Most importantly, we find that nanoscale morphology in both SqP and BC BHJs can be systematically controlled by tuning the amorphous fraction of polymer in the active layer. © 2014 American Chemical Society

Synchronous Occurrence of Collagenous and Pseudomembranous Colitis

Synchronous collagenous and pseudomembranous colitis has not been previously reported. A 73-year-old woman presented with chronic watery diarrhea and abdominal cramping of six weeks’ duration. Biopsies of the colon revealed findings of collagenous colitis involving the endoscopically normal right colon, and superimposed collagenous and pseudomembranous colitis involving the rectosigmoid colon. Endoscopically, the left colon revealed discrete ulcerative plaques, and Clostridium difficile toxin A assay was positive. The patient partially responded to a three-week regimen of metronidazole, and symptoms resolved completely with subsequent steroid therapy. At follow-up endoscopy four months later, colon biopsies demonstrated persistence of subepithelial collagen but no pseudomembranes. The patient remained asymptomatic during this interval. Collagenous colitis has been reported in association with other inflammatory bowel diseases, including lymphocytic colitis, sprue and idiopathic inflammatory bowel disease. This unique association of collagenous colitis with an endotoxigenic inflammatory bowel disease is presented with a review of related disease features

Managerial training as an instrument of change in health. The educational objectives and their verification in managerial training courses for the health administrators in the G. Sanelli Institute of Hygiene, 1988-1998

Gli autori descrivono i risultati in termini di formazione degli studenti di corsi di perfezionamento in formazione manageriale per operatori sanitari svolti nel periodo 1988-1998. L'analisi si basa sia su valutazioni quantitative che qualitative

Understanding the Formation Mechanism of Metal Nanocrystal@MOF-74 Hybrids

We report a one-step synthetic strategy to encapsulate copper nanocrystals (Cu NCs) in a carboxylate-based metal organic framework (MOF-74) to construct Cu@Cu-MOF-74 hybrids. One of the hurdles to realizing metal NC@MOF hybrids with uniform morphology and with a homogeneous NC spatial distribution by chemical transformation is to precisely match the metal dissolution rate and the MOF crystallization rate. Our study defines the parameter space which controls this kinetic balance. Such an understanding and the generality of our approach is crucial to develop rules of design for NC@MOF hybrids, which represent an attractive class of materials for several applications

La formazione manageriale degli operatori sanitari: Un approccio multidisciplinare per valutarne qualità ed efficacia

Objectives: to evaluate the effectiveness and the quality of a training course for health managers, using qualitative and quantitative instruments. Materials and methods: the achievements and the satisfaction of the participants have been evaluated by (a) an open-answers questionnaire, administered both as entrance and exit test, aimed at evaluating the changes in knowledge regarding six key-concepts of the management: quality, resources, needs, projects, communication, responsibility; (b) a questionnaire administered on the occasion of the end of each module, aimed at evaluating the satisfaction about the level of teachers and the contents of the course; (c) a form to be filled by each component atfter the presentation of the projects prepared by the different groups of participants as a core achievement of the course, aimed at obtaining individual judgements about each project

Reply to Trabeculectomy Versus EX-PRESS Shunt Versus Ahmed Valve Implant: Short-term Effects on Corneal Endothelial Cells

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