Crossing of shears bands in196Pb

High-spin states in¹⁹⁶Pb have been populated using the reaction¹⁷⁰Er(³⁰Si,4n). The previously observed shears bands in this nucleus have been extended and some of their transitions have been reordered. They now form regular bands with band crossings. One of the bands splits into two pathways at high spin.     

Trace element concentrations from São Francisco River - PR analyzed with PIXE technique

Summary Kulcsszavak (angolul, ha nem azonos az elozovel)     

Packing into the smallest square: Worst-case analysis of lower bounds

We address the problem of packing a given set of rectangles into the minimum size square. We consider three versions of the problem, arising when the rectangles (i) are squares; (ii) have a fixed orientation; (iii) can be rotated by 90. For each case we study lower bounds, and analyze their worst-case performance ratio. In addition, we evaluate through computational experiments their average performance on instances from the literature.     

A remark on Serrin’s Theorem

An approximation theorem for families of weakly coercive convex functions by means of countably many smooth families of convex functions is proved. As a consequence, the classical “three-fold” lower semicontinuity theorem for integral functionals of the Calculus of Variations by James Serrin is unified in one single statement.     

Ab initio path-integral molecular dynamics

A path-integral molecular dynamics technique for strongly interacting atoms using ab initio potentials derived from density functional theory is implemented. This allows the efficient inclusion of nuclear quantum dispersion in ab initio simulations at finite temperatures. We present an application to the quantum cluster H ₅ ⁺ .     

General theorems and fundamental solutions in the dynamical theory of mixtures

This paper is concerned with the dynamic theory of a binary mixture consisting of a gas and an elastic solid. First, we derive general theorems (reciprocal theorem, uniqueness theorem, minimum principle). The, we establish a Galerkin representation and the fundamental solutions in the case of steady vibrations.Work performed under the auspices of G.N.F.M. of the Italian Research Council (C.N.R.), with the grant 60% M.U.R.S.T. (ITALY).     

Integer linear programming models for 2-staged two-dimensional Knapsack problems

 We are given a unique rectangular piece of stock material S, with height H and width W, and a list of m rectangular shapes to be cut from S. Each shape's type i (i = 1, ..., m) is characterized by a height , a width , a profit , and an upper bound ub _i indicating the maximum number of items of type i which can be cut. We refer to the Two-Dimensional Knapsack (TDK) as the problem of determining a cutting pattern of S maximizing the sum of the profits of the cut items. In particular, we consider the classical variant of TDK in which the maximum number of cuts allowed to obtain each item is fixed to 2, and we refer to this problem as 2-staged TDK (2TDK). For the 2TDK problem we present two new Integer Linear Programming models, we discuss their properties, and we compare them with other formulations in terms of the LP bound they provide. Finally, both models are computationally tested within a standard branch-and-bound framework on a large set of instances from the literature by reinforcing them with the addition of linear inequalities to eliminate symmetries. Received: October 17, 2000 / Accepted: December 19, 2001 Published online: September 27, 2002 Key words. packing – cutting – integer linear programming     

Synthesis and characterization of poly(methyl methacrylate)‐block‐poly(methylphenylsilane)‐ block‐poly(methyl methacrylate) by atom transfer radical polymerization

ABA block copolymers of methyl methacrylate and methylphenylsilane were synthesized with a methodology based on atom transfer radical polymerization (ATRP). The reaction of samples of α,ω‐dihalopoly(methylphenylsilane) with 2‐hydroxyethyl‐2‐methyl‐2‐bromoproprionate gave suitable macroinitiators for the ATRP of methyl methacrylate. The latter procedure was carried out at 95 °C in a xylene solution with CuBr and 2,2‐bipyridine as the initiating system. The rate of the polymerization was first‐order with respect to monomer conversion. The block copolymers were characterized with ¹H NMR and ¹³C NMR spectroscopy and size exclusion chromatography, and differential scanning calorimetry was used to obtain preliminary evidence of phase separation in the copolymer products. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 30–40, 2003