The MCNP5 Monte Carlo code has been frequently used to model HTGRs with explicit geometric representation of fuel compacts or pebbles, including the microscopic fuel kernels within them. The random locations of fuel kernels within each fuel compact or pebble, and of pebbles within the core, however, present difficulties. A new, on-the-fly, stochastic geometry model for MCNP5 has been developed ...

Modeling of shape-memory alloys represents a multiscale problem due to occurrence of martensite/austenite phase transformation and a microstructure in the deformation gradient typical for martensitic phase. Inspired by relaxation in static situation, a limit passage between two modeling scales, called microand meso-scales, is performed for the corresponding evolution variants with considering a...

This paper focuses on the mathematical modeling for 5-axis milling with a filleted end mill. Several coordinate systems are introduced to describe the relationship between a cutter orientation and a machined surface. Then, a cutting point on a cutting edge is geometrically formulated as an integrated form of some expressions. The fundamental simulations based on the modeling were implemented to...

An overview is given of the modeling of the hydrodynamics, transport phenomena and chemical reactions in single-wafer LPCVD reactors, both at the macroscopic (reactor-scale) and a t the microscopic (feature-scale) level. Examples of modeling results f o r single-wafer silicon LPCVD from silane and tungsten LPCVD from tungsten hexafluoride and hydrogen a r e presented and comparisons a r e made ...

Ethology is the study of behavior that allows animals to survive and reproduce in natural environments (i.e., adaptive behavior). Neuroethology is the study of the neural basis of adaptive behavior. Computational neuroethology is the use of modeling and simulation to study the neural control of adaptive behavior. In contrast, the broad area of computational neuroscience generally focuses on mod...

We review the challenges for atomic scale modeling of alternative gate dielectric stacks. We begin by highlighting recent achievements of state-of-the-art atomistic simulations of the Si/SiO2 system, showing how such calculations have elucidated the microscopic origins of several important experimental phenomena. For the benefit of readers who may be unfamiliar with the simulation tools, we ove...

Modeling techniques evolved a lot during the last half century. Acceleration models used for microscopic traffic simulation are heterogeneous. For instance, differential equation based models are different from agent based ones. Comparison of those models is a difficult task because studies are often conducted based on a suitable and particular theory, usually not applicable to all models. So w...

In this paper, we rigorously derive a diffusion model for semiconductor superlattices, starting from a kinetic description of electron transport at the microscopic scale. Electron transport in the superlattice is modelled by a collisionless Boltzmann equation subject to a periodic array of localized scatters modeling the periodic heterogeneities of the material. The limit of a large number of p...

The infrared behaviour of the φ 3-theory is discussed stressing analogies with the Witten-Seiberg story about N = 2 QCD. Though the microscopic theory is apparently not integrable, the effective theory is shown to be integrable at classical level, and a general solution of it in terms of hypergeometric functions is obtained. An effective theory for the multiparticle soft scattering is sketched.