28 research outputs found
Isotope Shift in the Dielectronic Recombination of Three-electron \u3csup\u3eA\u3c/sup\u3eNdâ”â·âș
Isotope shifts in dielectronic recombination spectra were studied for Li-like ANd57+ ions with A = 142 and A = 150. From the displacement of resonance positions energy shifts ÎŽE142 150(2s-2p1/2) = 40.2(3)(6) meV [(stat)(sys)] and ÎŽE142 150(2s - 2p3/2) = 42.3(12)(20)meV of 2s - 2pj transitions were deduced. An evaluation of these values within a full QED treatment yields a change in the mean-square charge radius of 142 150ÎŽâš r2â© = -1.36(1)(3) fm2. The approach is conceptually new and combines the advantage of a simple atomic structure with high sensitivity to nuclear size
Parallel Tree Search in Volunteer Computing: a Case Study
International audienc
Translating the Object Constraint Language into First-order Predicate Logic
Abstract. In this paper, we define a translation of UML class diagrams with OCL constraints into first-order predicate logic. The goal is logical reasoning about UML models, realized by an interactive theorem prover. We put an emphasis on usability of the formulas resulting from the translation, and we have developed optimisations and heuristics to enhance the efficiency of the theorem proving process. The translation has been implemented as part of the KeY system, but our implementation can also be used stand-alone.
Alternative Process Routes to Manufacture Porous CeramicsâOpportunities and Challenges
Porous ceramics can be realized by different methods and are used for various applications such as cross-flow membranes or wall-flow filters, porous burners, solar receivers, structural design elements, or catalytic supports. Within this paper, three different alternative process routes are presented, which can be used to manufacture porous ceramic components with different properties or even graded porosity. The first process route is based on additive manufacturing (AM) of macro porous ceramic components. The second route is based on AM of a polymeric template, which is used to realize porous ceramic components via replica technique. The third process route is based on an AM technology, which allows the manufacturing of multimaterial or multiproperty ceramic components, like components with dense and porous volumes in one complex-shaped component