Multi-Architecture Monte-Carlo (MC) Simulation of Soft Coarse-Grained Polymeric Materials: SOft coarse grained Monte-carlo Acceleration (SOMA)

Multi-component polymer systems are important for the development of new materials because of their ability to phase-separate or self-assemble into nano-structures. The Single-Chain-in-Mean-Field (SCMF) algorithm in conjunction with a soft, coarse-grained polymer model is an established technique to investigate these soft-matter systems. Here we present an im- plementation of this method: SOft coarse grained Monte-carlo Accelera- tion (SOMA). It is suitable to simulate large system sizes with up to billions of particles, yet versatile enough to study properties of different kinds of molecular architectures and interactions. We achieve efficiency of the simulations commissioning accelerators like GPUs on both workstations as well as supercomputers. The implementa- tion remains flexible and maintainable because of the implementation of the scientific programming language enhanced by OpenACC pragmas for the accelerators. We present implementation details and features of the program package, investigate the scalability of our implementation SOMA, and discuss two applications, which cover system sizes that are difficult to reach with other, common particle-based simulation methods

Quantum Populations in Zeno Regions inside Black Holes

Schwarzschild black-hole interiors border on space-like singularities representing classical information leaks. We show that local quantum physics is decoupled from these leaks due to dynamically generated boundaries, called Zeno borders. Beyond Zeno borders black-hole interiors become asymptotically silent, and quantum fields evolve freely towards the geodesic singularity with vanishing probability measure for populating the geodesic boundary. Thus Zeno borders represent a probabilistic completion of Schwarzschild black holes within the semiclassical framework.Comment: 5 pages, 2 figures, more pedagogical presentation of our unchanged results including an introduction to Zeno region

Module extraction via query inseparability in OWL 2 QL

We show that deciding conjunctive query inseparability for OWL 2 QL ontologies is PSpace-hard and in ExpTime. We give polynomial-time (incomplete) algorithms and demonstrate by experiments that they can be used for practical module extraction

Improvement of Groin Pain in a Football Player with Femoroacetabular Impingement via a Correction of the Pelvic Position—A Case Report

Background: Femoroacetabular impingement is one possible cause for groin pain and can lead to long periods of absence for football players. In cam impingement, the end-grade position of the leg at kicking makes the hip particularly prone to faulty contact between the acetabulum and the femoral head. Studies suggest that the resting position of the pelvis in the sagittal plane may have an important role in the biomechanics of movement in the presence of cam impingement. Methods: A 19-year-old male competitive footballer complained of sudden groin pain during a period of low athletic load. Biomechanical tests (3D posture and isometric strength analyses) showed that unbalanced individual strength training had resulted in an increased forward tilt of the pelvis. At the same time, cam impingement was confirmed radiologically, which obviously contributed to the sudden onset of the symptoms. The kicking technique of the athlete showed increased hip and trunk flexion, which also indicated a muscular imbalance. Targeted strength and stretching exercises three times a week improved the pelvic position in terms of reduced anteversion. At the same time, the patient performed strength exercises to improve his kicking technique. Results: After 8 weeks, improvements in his pelvic position and global posture and increased muscle strength could be verified. At the same time, the athlete was free of complaints again. Conclusions: When groin pain occurs in football players with cam impingement, special attention should be paid to the resting position of the pelvis in the sagittal plane. Correcting increased pelvic anteversion can prevent unfavourable end-grade collisions of the acetabulum and femoral head during kicking with strong hip flexion and adduction. Possible changes in the pelvic position due to adverse individual strength training performed by young athletes should always be kept in mind

Magnetic properties of single nanomagnets: EMCD on FePt nanoparticles

Energy-loss magnetic chiral dichroism (EMCD) allows for the quantification of magnetic properties of materials at the nanometer scale. It is shown that with the support of simulations that help to identify the optimal conditions for a successful experiment and upon implementing measurement routines that effectively reduce the noise floor, EMCD measurements can be pushed towards quantitative magnetic measurements even on individual nanoparticles. With this approach, the ratio of orbital to spin magnetic moments for the Fe atoms in a single L$1_0$ ordered FePt nanoparticle is determined to be ${m_l}/{m_s} = 0.08 \pm 0.02$. This finding is in good quantitative agreement with the results of XMCD ensemble measurements.Comment: 35 pages, 10 figure