Potassium Rankine cycle vapor chamber (heat pipe) radiator study

A structurally integrated vapor chamber fin (heat pipe) radiator is defined and evaluated as a potential candidate for rejecting waste heat from the potassium Rankine cycle powerplant. Several vapor chamber fin geometries, using stainless steel construction, are evaluated and an optimum is selected. A comparison is made with an operationally equivalent conduction fin radiator. Both radiators employ NaK-78 in the primary coolant loop. In addition, the Vapor Chamber Fin (VCF) radiator utilizes sodium in the vapor chambers. Preliminary designs are developed for the conduction fin and VCF concepts. Performance tests on a single vapor chamber were conducted to verify the VCF design. A comparison shows the conduction fin radiator easier to fabricate, but heavier in weight, particularly as meteoroid protection requirements become more stringent. While the analysis was performed assuming the potassium Rankine cycle powerplant, the results are equally applicable to any system radiating heat to space in the 900 to 1400 F temperature range

Dynamic Capabilities: Innovation Project Portfolio Management

Innovation Project Portfolio Management (IPPM) practices are a dynamic capability that provides competitive advantage by dynamically adjusting the organisation’s portfolio of projects and resource allocation profile for the best innovation outcomes. A relatively new body of empirical research into IPPM practices is starting to generate findings related to IPPM practices and innovation outcomes. However this research is fragmented and lacks a unifying theoretical base. The resource-based view of strategy, in particular the dynamic capabilities approach, provides a theoretical framework to unify IPPM research. A ‘processes, positions and paths’ perspective on IPPM practices helps to clarify the ways that IPPM practices contribute to competitive advantage. Existing empirical research into the processes used for IPPM reveals some links to innovation outcomes, but does not try to explain causality. Improved understanding of the mechanisms responsible for competitive advantage through IPPM practices is found in research on positions (how IPPM processes draw upon and contribute to the underlying resource position) and paths (the role of past decisions and organisational paths in shaping IPPM processes as well as future options and decisions).14 page(s

Project portfolio management for product innovation

The purpose of this paper is to create a benchmark and identify best practices for Project Portfolio Management (PPM) for both tangible product-based and service product-based development project portfolios. A questionnaire was developed to gather data to compare the PPM methods used, PPM performance, PPM challenges, and resulting new product success measures in 60 Australian organisations in a diverse range of service and manufacturing industries. The paper finds that PPM practices are shown to be very similar for service product development project portfolios and tangible product development project portfolios. New product success rates show strong correlation with measures of PPM performance and the use of some PPM methods is correlated with specific PPM performance outcomes. The findings in this paper are based on a survey of a diverse sample of 60 Australian organisations. The results are strengthened by comparisons with similar North American research; however, they may not be representative of all environments. Research in other regions would further qualify the findings. As each organisation's PPM process is unique, case study methods are recommended for future studies to capture more of the complexity in the environment. The paper shows that PPM practitioners and executives who make decisions about the development of tangible products and/or service products will benefit from the findings. This paper extends the existing understanding of PPM practices to include service development project portfolios as well as tangible product development project portfolios and strengthens the links between PPM practices and outcomes

Learning investments and organizational capabilities: case studies on the development of project portfolio management capabilities

Purpose The purpose of this paper is to improve understanding and provide guidance for investments in organizational learning mechanisms for the establishment and evolution of organizational capabilities such as project portfolio management (PPM) and project management capabilities. Design/methodology/approach A multiple-case study research project investigates the development of PPM capabilities in six successful organizations across diverse industries. Findings The research indicates that PPM and organizational learning are dynamic capabilities that enhance an organization's ability to achieve and maintain competitive advantage in dynamic environments. PPM capabilities are shown to co-evolve through a combination of tacit experience accumulation, explicit knowledge articulation and explicit knowledge codification learning mechanisms. Although all three learning mechanisms are important throughout the establishment and evolution of PPM capability development, the research indicates that the development of an effective PPM capability will require particularly strong investments in enhancing tacit experience accumulation mechanisms and explicit knowledge codification mechanisms during the initial establishment or during periods of radical change to the PPM process

Long life reliability thermal control systems study

The results of a program undertaken to conceptually design and evaluate a passive, high reliability, long life thermal control system for space station application are presented. The program consisted of four steps: (1) investigate and select potential thermal system elements; (2) conceive, evaluate and select a thermal control system using these elements; (3) conduct a verification test of a prototype segment of the selected system; and (4) evaluate the utilization of waste heat from the power supply. The result of this project is a conceptual thermal control system design which employs heat pipes as primary components, both for heat transport and temperature control. The system, its evaluation, and the test results are described

A Concept for Small, Remotely Operated, Coronagraph located at Small Observatory to Obtain Frequent Low-cost Remote Observations of the Lunar Exosphere and the Mercurian Tail

The sodium in the lunar exosphere is a marker species for studying the lunar exosphere because the element possesses two strong resonance transitions from the ground state whose wavelengths fall in the visible spectrum near 590 nm. Emissions at these wavelengths are thus, observable from Earth. Observations have shown that the exosphere responds in a complex way to the external processes (impact vaporization, sputtering, and photon stimulated desorption) that weather the lunar regolith to produce the sodium. Unraveling the sodium production allows us to study the processes that weather the regolith. Obtaining the extensive time sequence of observations required to unravel the sources of sodium using conventional observatories is impractical, and too expensive. Effectively imaging the lunar sodium exosphere dose to the Moon requires an off-axis rejection of scattered light that can only be obtained with a coronagraph. A related problem. the observation of the sodium tail of Mercury, can be addressed as well only by coronagraphic observations. We present here a concept for a small, rugged coronagraph sited at an observatory dedicated to remote robotic observing (the Winer Observatory in Sonoita Arizona) that can obtain the quality and quantity of lunar sodium observations needed to answer these questions. The design uses Commercial Off the Shelf Technology (COTS). If this facility is operational by 2013. the observations will be concurrent with the Lunar Atmosphere and Dust Environment Explorer (LADEE) mission

Sodium Velocity Maps on Mercury

The objective of the current work was to measure two-dimensional maps of sodium velocities on the Mercury surface and examine the maps for evidence of sources or sinks of sodium on the surface. The McMath-Pierce Solar Telescope and the Stellar Spectrograph were used to measure Mercury spectra that were sampled at 7 milliAngstrom intervals. Observations were made each day during the period October 5-9, 2010. The dawn terminator was in view during that time. The velocity shift of the centroid of the Mercury emission line was measured relative to the solar sodium Fraunhofer line corrected for radial velocity of the Earth. The difference between the observed and calculated velocity shift was taken to be the velocity vector of the sodium relative to Earth. For each position of the spectrograph slit, a line of velocities across the planet was measured. Then, the spectrograph slit was stepped over the surface of Mercury at 1 arc second intervals. The position of Mercury was stabilized by an adaptive optics system. The collection of lines were assembled into an images of surface reflection, sodium emission intensities, and Earthward velocities over the surface of Mercury. The velocity map shows patches of higher velocity in the southern hemisphere, suggesting the existence of sodium sources there. The peak earthward velocity occurs in the equatorial region, and extends to the terminator. Since this was a dawn terminator, this might be an indication of dawn evaporation of sodium. Leblanc et al. (2008) have published a velocity map that is similar

Epidermal growth factor receptors in intracranial and breast tumours: their clinical significance.

A method to determine the binding of epidermal growth factor (EGF) to the particulate fraction of the cell has been established and evaluated using rat liver, human placenta, and tumours of human breast and brain. Little EGF receptor (EGFR) activity was detected in normal or benign tumour tissues except for meningioma (positive in 95% samples), but EGFR were present in 43% of 131 breast tumours and 75% of 55 primary cerebral tumours. Despite the strong inverse correlation between EGFR activity and oestrogen receptors in breast tumours and a tendency for high levels of EGFR activity to be associated with glioblastoma multiforme, analysis showed that EGFR was of little prognostic significance in patients with tumours of either breast or brain