Research on the mechanism and kinetics of oxidation of silicon in air Semiannual report, 1 Dec. 1966 - 31 May 1967

Mechanism and kinetics of silicon oxidation in air-instrumentation for ellipsometry and use in determining refractive index and thickness of thin oxide films on silico

Research on the Mechanism and Kinetics of Oxidation of Silicon in Air Semiannual Report, 1 Jun. - 30 Nov. 1966

Ellipsometric studies on mechanism and kinetics of thin oxide films on silicon in ai

Research and study in system optimization techniques Second quarterly progress report, Feb. 14 - May 14, 1965

Systems optimization for motion stability matrix problem - predictive guidance for Thor vehicle trajector

Understanding contextualised rational action - author's response

Understanding contextualised rational action - author's respons

Interfacial Thermal Resistance Between Carbon Nanotubes: Molecular Dynamics Simulations and Analytical Thermal Modeling

Interfacial thermal transport between offset parallel (10,10) single-wall carbon nanotubes is investigated by molecular dynamics simulation and analytical thermal modeling as a function of nanotube spacing, overlap, and length. A four order of magnitude reduction in interfacial thermal resistance is found as the nanotubes are brought into intimate contact. A reduction is also found for longer nanotubes and for nanotubes with increased overlap area. Thermal resistance between a nanotube and a reservoir at its boundary increases with decreasing reservoir temperature. Additionally, length-dependent Young\u27s moduli and damping coefficients are calculated based on observed nanotube deflections

Velocity and Stress Autocorrelation Decay in Isothermal Dissipative Particle Dynamics

The velocity and stress autocorrelation decay in a dissipative particle dynamics ideal fluid model is analyzed in this paper. The autocorrelation functions are calculated at three different friction parameters and three different time steps using the well-known Groot/Warren algorithm and newer algorithms including selfconsistent leap-frog, self-consistent velocity Verlet and Shardlow first and second order integrators. At low friction values, the velocity autocorrelation function decays exponentially at short times, shows slower-than exponential decay at intermediate times, and approaches zero at long times for all five integrators. As friction value increases, the deviation from exponential behavior occurs earlier and is more pronounced. At small time steps, all the integrators give identical decay profiles. As time step increases, there are qualitative and quantitative differences between the integrators. The stress correlation behavior is markedly different for the algorithms. The self-consistent velocity Verlet and the Shardlow algorithms show very similar stress autocorrelation decay with change in friction parameter, whereas the Groot/Warren and leap-frog schemes show variations at higher friction factors. Diffusion coefficients and shear viscosities are calculated using Green-Kubo integration of the velocity and stress autocorrelation functions. The diffusion coefficients match well-known theoretical results at low friction limits. Although the stress autocorrelation function is different for each integrator, fluctuates rapidly, and gives poor statistics for most of the cases, the calculated shear viscosities still fall within range of theoretical predictions and nonequilibrium studies

Acoustic phonon scattering from particles embedded in an anisotropic medium: A molecular dynamics study

Acoustic phonon scattering from isolated nanometer-scale impurity particles embedded in anisotropic media is investigated using molecular dynamics simulation. The spectral-directional dependence of the scattering, for both longitudinal and transverse modes, is found through calculation of scattering cross sections and three dimensional scattering phase functions for inclusions of varying sizes, shapes, and stiffnesses and for waves of different wave numbers. The technique enables direct observation of the effects of mode conversion, lattice mismatch strain, elastic anisotropy, and atomistic granularity on acoustic phonon scattering from nanoparticles. The results will be useful for the design of nanoparticle-based thermal insulating materials, for example, quantum dot superlattices for thermoelectric energy conversion

Modeling flows in periodically heterogeneous porous media with deformation-dependent permeability

The paper proposes a non-linear model of the Biot continuum. The nonlienarity is introduced in terms of the material coefficients which are expressed as linear functions of the macroscopic response. These functions are obtained by the sensitivity analysis of the homogenized coefficients computed for a given geometry of the porous structure which transforms due to the local deformation. Linear kinematics is assumed, however, the approach can be extended to large deforming porous materials

Molecular Dynamics Simulation of Thermal Conduction in Nanoporous Thin Films

Molecular dynamics simulations of thermal conduction in nanoporous thin films are performed. Thermal conductivity displays an inverse temperature dependence for films with small pores and a much less pronounced dependence for larger pores. Increasing porosity reduces thermal conductivity, while pore shape has little effect except in the most anisotropic cases. The pores separate the film into local regions with distinctly different temperature profiles and thermal conductivities, and the effective film thermal conductivity is lowest when the pores are positioned in the center of the film. Such tunability by pore placement highlights new possibilities for engineering nanoscale thermal transport

Development of a high-performance transtibial cycling-specific prosthesis for the London 2012 Paralympic Games

Background and Aim It has been reported that cycling-specific research relating to participants with an amputation is extremely limited in both volume and frequency. However, practitioners might participate in the development of cycling-specific prosthetic limbs. This technical note presents the development of a successful design of a prosthetic limb developed specifically for competitive cycling. Technique This project resulted in a hollow composite construction which was low in weight and shaped to reduce a rider’s aerodynamic drag. Discussion The new prosthesis reduces the overall mass of more traditional designs by a significant amount yet provides a more aerodynamic shape over traditional approaches. These decisions have yielded a measurable increase in cycling performance. Whilst further refinement is needed to reduce the aerodynamic drag as much as possible, this project highlights the benefits that can exist by optimising the design of sports-specific prosthetic limbs