Advanced photovoltaic power system technology for lunar base applications

Advanced photovoltaic/electrochemical (batteries or regenerative fuel cells for storage) power system options for a lunar base are discussed and compared. Estimated system masses are compared with those projected for the SP-100 nuclear system. The results of the comparison are quantified in terms of the mass saved in a scenario which assembles the initial base elements in Low Earth Orbit (LEO) and launches from there to the lunar surface. A brief summary is given of advances in photovoltaic/electrochemical power system technologies currently under development in the NASA/OAST program. A description of the planned focussed technology program for surface power in the new Pathfinder initiative is also provided

Advanced photovoltaic power system technology for lunar base applications

The development of an advanced photovoltaic power system that would have application for a manned lunar base is currently planned under the Surface Power element of Pathfinder. Significant mass savings over state-of-the-art photovoltaic/battery systems are possible with the use of advanced lightweight solar arrays coupled with regenerative fuel cell storage. The solar blanket, using either ultrathin GaAs or amorphous silicon solar cells, would be integrated with a reduced-g structure. Regenerative fuel cells with high-pressure gas storage in filament-wound tanks are planned for energy storage. An advanced PV/RFC power system is a leading candidate for a manned lunar base as it offers a tremendous weight advantage over state-of-the-art photovoltaic/battery systems and is comparable in mass to other advanced power generation technologies

Dual-purpose self-deliverable lunar surface PV electrical power system

A safe haven and work supported PV power systems on the lunar surface will likely be required by NASA in support of the manned outpost scheduled for the post-2000 lunar/Mars exploration and colonization initiative. Initial system modeling and computer analysis shows that the concept is workable and contains no major high risk technology issues which cannot be resolved in the circa 2000 to 2025 timeframe. A specific selection of the best suited type of electric thruster has not been done; the initial modeling was done using an ion thruster, but Rocketdyne must also evaluate arc and resisto-jets before a final design can be formulated. As a general observation, it appears that such a system can deliver itself to the Moon using many system elements that must be transported as dead payload mass in more conventional delivery modes. It further appears that a larger power system providing a much higher safe haven power level is feasible if this delivery system is implemented, perhaps even sufficient to permit resource prospecting and/or lab experimentation. The concept permits growth and can be expanded to include cargo transport such as habitat and working modules. In short, the combined payload could be manned soon after landing and checkout. NASA has expended substantial resources in the development of electric propulsion concepts and hardware that can be applied to a lunar transport system such as described herein. In short, the paper may represent a viable mission on which previous investments play an invaluable role. A more comprehensive technical paper which embodies second generation analysis and system size will be prepared for near-term presentation

Non-perturbative aspects of particle acceleration in non-linear electrodynamics

We undertake an investigation of particle acceleration in the context of non-linear electrodynamics. We deduce the maximum energy that an electron can gain in a non-linear density wave in a magnetised plasma, and we show that an electron can 'surf' a sufficiently intense Born-Infeld electromagnetic plane wave and be strongly accelerated by the wave. The first result is valid for a large class of physically reasonable modifications of the linear Maxwell equations, whilst the second result exploits the special mathematical structure of Born-Infeld theory

Macroscopic transport by synthetic molecular machines

Nature uses molecular motors and machines in virtually every significant biological process, but demonstrating that simpler artificial structures operating through the same gross mechanisms can be interfaced with—and perform physical tasks in—the macroscopic world represents a significant hurdle for molecular nanotechnology. Here we describe a wholly synthetic molecular system that converts an external energy source (light) into biased brownian motion to transport a macroscopic cargo and do measurable work. The millimetre-scale directional transport of a liquid on a surface is achieved by using the biased brownian motion of stimuli-responsive rotaxanes (‘molecular shuttles’) to expose or conceal fluoroalkane residues and thereby modify surface tension. The collective operation of a monolayer of the molecular shuttles is sufficient to power the movement of a microlitre droplet of diiodomethane up a twelve-degree incline.

Influence of Maternal Abandonment, High-Crime Neighborhoods, and Experienced Abuse on Aggressive Assaultive Behavior

Assault crimes committed by men in the United States need to be studied empirically if a significant reduction in their occurrence is to take place. The purpose of this nonexperimental quantitative study was to examine the relationship between the reported experience of abuse, growing up in a high-crime neighborhood (HCN), and maternal abandonment with regards to individuals incarcerated for crimes that were operationally classified in this study as aggressive assaultive behavior (AAB). The framework that grounded this study was Bronfenbrenner’s ecology of human development and Beck’s perspective on framing, which guided the focus on how an individual frames an experience that results in a thought or behavioral response (i.e., AAB). Data were mined from a classification center within the northeastern region of the United States. Using a binary logistic regression, coupled with a step-wise regression, the null hypothesis was rejected; there was a significant difference when combining the experience of abuse with living in an HCN (p = .009). The results reflected an agreement with the grounded theory, but not with a representation of the original hypothesis. The recommendation was to investigate AAB as a phenological study to better understand those affected as individuals rather than as statistics. This study may be used to facilitate positive social change through a new therapeutic model aimed at conceptualizing AAB in an effort to reduce recidivism rates among men convicted of violent crimes

Sustainability Transitions in Tourism in the Margaret River Region (Western Australia, Australia)

Sustainability Transitions Research (STR) investigates shifts in sociotechnical systems towards sustainability. Despite tourism's socioenvironmental impact, it has been neglected in STR. This thesis addresses this gap by applying multi-level perspective and path-dependence theory to analyse the move towards sustainable tourism in the Margaret River region (WA). This thesis identifies a historical transition (1950s-1990s) followed by a sustainability transition (early 2000s-present) as well as complex factors influencing the ongoing sustainability transition in this wine-tourism destination