Cavity reactor critical experiment, volume 3

Cavity reactor critical experiment - volume

Gas cavity reactor simulation experiment final report

Gaseous cavitation reactor simulation experiment using uranium fluoride fue

Cavity reactor critical experiment, volume 4 (waves and control methods)

Fuel wave formation and control in coaxial flowing gas cavity reactor for space nuclear propulsio

Flowing gas, non-nuclear experiments on the gas core reactor

Flow tests were conducted on models of the gas core (cavity) reactor. Variations in cavity wall and injection configurations were aimed at establishing flow patterns that give a maximum of the nuclear criticality eigenvalue. Correlation with the nuclear effect was made using multigroup diffusion theory normalized by previous benchmark critical experiments. Air was used to simulate the hydrogen propellant in the flow tests, and smoked air, argon, or freon to simulate the central nuclear fuel gas. All tests were run in the down-firing direction so that gravitational effects simulated the acceleration effect of a rocket. Results show that acceptable flow patterns with high volume fraction for the simulated nuclear fuel gas and high flow rate ratios of propellant to fuel can be obtained. Using a point injector for the fuel, good flow patterns are obtained by directing the outer gas at high velocity along the cavity wall, using louvered or oblique-angle-honeycomb injection schemes

Electronic transport properties through thiophenes on switchable domains

The electronic transport of electrons and holes through stacks of $\alpha$,\ome ga-dicyano-$\beta$,$\beta$'-dibutyl- quaterthiophene (DCNDBQT) as part of a nov el organic ferroic field-effect transistor (OFFET) is investigated. The novel ap plication of a ferroelectric instead of a dielectric substrate provides the poss ibility to switch bit-wise the ferroelectric domains and to employ the polarizat ion of these domains as a gate field in an organic semiconductor. A device conta ining very thin DCNDBQT films of around 20 nm thickness is intended to be suitab le for logical as well as optical applications. We investigate the device proper ties with the help of a phenomenological model called multilayer organic light-e mitting diodes (MOLED), which was extended to transverse fields. The results sho wed, that space charge and image charge effects play a crucial role in these org anic devices

Cavity Reactor Engineering Mockup Critical Experiment

Critical mass of uranium 235 for stainless steel lined cavities in nuclear research and test reactors with heavy water reflecto

Best Practices for Urban Densification: A decision-making support process using microclimate analysis methods and parametric models for optimizing urban climate comfort

This paper presents an approach for microclimate aware densification of urban areas by creating best practices for an in situ application for block-size urban developments. The discussed procedure generates and evaluates urban block types according to microclimate criteria by integrating climate and comfort parameters in the design process of existing urban areas. It supports urban designers by generating design strategies that aim for climate, comfort and spatial as well as for urban design qualities. To achieve this, a multi-step method with different analysis and research processes has been set up. At the end, a parametric envelope tool was created for a local case study area by incorporating pre-defined design strategies built on previous investigations as urban design strategies. It is expected that this envelope tool can be transferred to similar urban development activities and guide microclimatic versus densification trade-offs. The presented approach can be applied from street canyon to block size urban situations

Compactness and asymptotic behavior in nonautonomous linear parabolic equations with unbounded coefficients in Rd\R^d

We consider a class of second order linear nonautonomous parabolic equations in R^d with time periodic unbounded coefficients. We give sufficient conditions for the evolution operator G(t,s) be compact in C_b(R^d) for t>s, and describe the asymptotic behavior of G(t,s)f as t-s goes to infinity in terms of a family of measures mu_s, s in R, solution of the associated Fokker-Planck equation