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An efficient implementation of an adaptive finite element method on distributed memory systems requires an efficient linear solver. Most solver methods, which show scalability to a large number of processors make use of some geometric information of the mesh. This information has to be provided to the solver in an efficient and solver specific way. We introduce data structures and numerical algorithms which fulfill this task and allow in addition for an user-friendly implementation of a large class of linear solvers. The concepts and algorithms are demonstrated for global matrix solvers and domain decomposition methods for various problems in fluid dynamics, continuum mechanics and materials science. Weak and strong scaling is shown for up to 16.384 processors. [ABSTRACT FROM AUTHOR]

The performance of linear shaped charges depends on several different parameters. The density, the detonation velocity of the explosive, the shape of the detonation wave, the shape and wall thickness of the liner, and the distance of the shaped charge from the target are among the parameters that can be optimized by using computer simulation methods. In this paper, the jet formation process in a linear shaped charge and its action on an obstacle are simulated by using the LS-DYNA software. The results obtained are compared with experimental data. [ABSTRACT FROM AUTHOR]

Background: Alvimopan is a peripherally acting mu-opioid receptor (PAM-OR) antagonist for accelerating gastrointestinal recovery after surgery.Methods: Patients undergoing open laparotomy (bowel resection, n = 418; hysterectomy, n = 197) were randomized to receive alvimopan 6 or 12 mg or placebo orally > or = 2 h before surgery and then b.i.d. until hospital discharge (up to 7 days). The primary efficacy endpoint was time to gastrointestinal (GI) recovery (measured by toleration of solid food and passage of flatus/stool; GI-3). Secondary endpoints included time to GI-2 recovery (toleration of solid food and passage of stool) and hospital discharge order written (DCO).Results: Alvimopan did not significantly accelerate GI-3 compared with placebo [6 mg: hazard ratio (HR) = 1.20, p = 0.080; 12 mg: HR = 1.24, p = 0.038). However, after adjustment for significant covariates (sex/surgical duration), benefits were significant for both doses (6 mg: HR = 1.24, p = 0.037; 12 mg: HR = 1.26, p = 0.028). Alvimopan also significantly accelerated time to GI-2 (6 mg: HR = 1.37, p = 0.008; 12 mg: HR = 1.33, p = 0.018) and DCO (6 mg: HR = 1.31, p = 0.008; 12 mg: HR = 1.28, p = 0.015). Adverse events were similar between groups.Conclusions: Alvimopan (6 or 12 mg) accelerates GI recovery and is well tolerated in patients undergoing open laparotomy. [ABSTRACT FROM AUTHOR]