Optical analysis of parabolic dish concentrators for solar dynamic power systems in space

An optical analysis of a parabolic solar collection system operating in Earth orbit was performed using ray tracing techniques. The analysis included the effects of: (1) solar limb darkening, (2) parametric variation of mirror surface error, (3) parametric variation of mirror rim angle, and (4) parametric variation of alignment and pointing error. This ray tracing technique used numerical integration to combine the effects of rays emanating from different parts of the sun at different intensities with the effects of normally distributed mirror-surface errors to compute the angular intensity distribution of rays leaving the mirror surface. A second numerical integration was then performed over the surface of the parabolic mirror to compute the radial distribution of brightness at the mirror focus. Major results of the analysis included: (1) solar energy can be collected at high temperatures with high efficiency, (2) higher absorber temperatures can be achieved at lower efficiencies, or higher efficiencies can be achieved at lower temperatures, and (3) collection efficiency is near its maximum level across a broad plateau of rim angles from 40 deg to 70 deg

Experimental investigation of reactor-loop transients during SNAP-8 power conversion system startup

Experimental investigation of reactor loop transients during SNAP 8 power conversion system startu

Digital computer study of nuclear reactor thermal transients during startup of 60-kWe Brayton power conversion system

A digital computer study was made of reactor thermal transients during startup of the Brayton power conversion loop of a 60-kWe reactor Brayton power system. A startup procedure requiring the least Brayton system complication was tried first; this procedure caused violations of design limits on key reactor variables. Several modifications of this procedure were then found which caused no design limit violations. These modifications involved: (1) using a slower rate of increase in gas flow; (2) increasing the initial reactor power level to make the reactor respond faster; and (3) appropriate reactor control drum manipulation during the startup transient

Session:management of drainage near source – disconnection/minimise surface water entering public drainage

Many combined sewer networks are currently constrained due to lack of capacity. Surface water entering the network may have an impact on the local environment by causing additional spills from Combined Sewer Overflows (CSOs) and flooding events. With the increasing number of developments taking place in Scotland, more and more demands are being placed upon the existing wastewater assets and infrastructure of the drainage utility, Scottish Water. The principal way of preventing these CSO spills/flooding event s is to reduce the number of surface water connections to the combined sewer network and promote more surface water discharges to nearby watercourses.The problem is being addressed by examining all development applications as they are considered by a drainage planning officer in the water authority. The research reported in this paper is investigating the conditions under which it is reasonable and practical for Scottish Water to accept surface water flows into its combined sewer network . This paper presents a summary of the initial findings of the research to date by examining a sample of the sites examined. The objective of the work is to develop a methodology to support a rigorous stance on the acceptance of surface water flows into the combined sewer network. The results have not as yet been obtained

Narrative: Textiles Transmission and Translations

Textile Transmissions and Translations is a research project that will take advantage of the ability of fabric to impart meaning through material and electronic languages, by combining a creative approach to the textile arts with technical innovations in circuitry and wireless transmissions; exploring ubiquitous computing, mobility and interactivity through the introduction of electronic devices into fabric structures; creating animated displays on the surface of cloth, in order to extend the dynamic, narrative abilities of cloth and developing a transitional space in which meanings are altered and textiles are invigorated into new patterns of discovery

Experimental investigation of reactor-loop transients during startup of a simulated SNAP-8 system

Primary loop transients during startup of Rankine cycle space power system in SNAP 8 simulato

A Methodology for Evaluating Liquefaction Susceptibility in Shallow Sandy Slopes

This paper illustrates a modeling approach for evaluating the liquefaction susceptibility of shallow sandy slopes. The methodology is based on a theoretical framework for capturing undrained bifurcation in saturated granular media. In order to provide predictive capabilities, the theory is combined with the MIT-S1 constitutive model. The role of a non-homogeneous density profile is investigated, distinguishing among the different forms of undrained response that can be induced by rapid shearing. The first part of the paper describes the general methodology and illustrates the use of a stability index for static liquefaction. In the second part, the practical significance of the approach is discussed by back-analyzing the well-known series of flow failures in an underwater berm at the Nerlerk site. The analyses predict that prior to failure the Nerlerk slopes were not yet beyond the limits of stability for incipient liquefaction. Model simulations, however, also indicate that very small shear perturbations could have activated an undrained instability. These results suggest that static liquefaction was a mechanically plausible failure mechanism and provide the first interpretation of the classical Nerlerk collapse based on the combined use of the theory of material stability and an advanced constitutive model for sands

Discussion: Non-uniqueness of flow liquefaction line for loose sand

published_or_final_versio

Evidence of traffic-related pollutant control in soil-based Sustainable Urban Drainage Systems (SUDS)

SUDS are being increasingly employed to control highway runoff and have the potential to protect groundwater and surface water quality by minimising the risks of both point and diffuse sources of pollution. While these systems are effective at retaining polluted solids by filtration and sedimentation processes, less is known of the detail of pollutant behaviour within SUDS structures. This paper reports on investigations carried out as part of a co-ordinated programme of controlled studies and field measurements at soft-engineered SUDS undertaken in the UK, observing the accumulation and behaviour of traffic-related heavy metals, oil and PAHs. The field data presented were collected from two extended detention basins serving the M74 motorway in the south-west of Scotland. Additional data were supplied from an experimental lysimeter soil core leaching study. Results show that basin design influences pollutant accumulation and behaviour in the basins. Management and/or control strategies are discussed for reducing the impact of traffic-related pollutants on the aqueous environment