Margins within margins?: voices Speaking through a study of the provision of an educational program for the children of one Australian show circuit

This paper examines the tactics used by the Showmen's Guild of Australasia in successfully lobbying for the development of a distance education program for their children. The Guild is considered to be a 'marginalized' group, meaning members have less access to wealth, power, and status. Since 1930, members of the Showmen's Guild and their families have traveled from town to town providing agricultural and equestrian shows. Despite the diversity of backgrounds and experiences among people connected with the show circuit, the Guild is highly organized and has been politically active. Informal sanctions have been effective in enforcing group discipline and in presenting the image of a single body of opinion. In addition, investment in sophisticated machinery and technology has resulted in show people having the financial resources to buy homes and have a political voice via more 'normalized channels'. Although members learn early that they are a marginalized group and are perceived as different from the mainstream, the group maintains close ties and often celebrates its difference. Implications for educational program development center on the goals of educational programs designed for disadvantaged groups, and the status of other marginalized groups and their efforts to contest their marginalized status. (LP

Topology of Cell-Aggregated Planar Graphs

We present new algorithm for growth of non-clustered planar graphs by aggregation of cells with given distribution of size and constraint of connectivity k=3 per node. The emergent graph structures are controlled by two parameters--chemical potential of the cell aggregation and the width of the cell size distribution. We compute several statistical properties of these graphs--fractal dimension of the perimeter, distribution of shortest paths between pairs of nodes and topological betweenness of nodes and links. We show how these topological properties depend on the control parameters of the aggregation process and discuss their relevance for the conduction of current in self-assembled nanopatterns.Comment: 8 pages, 5 figure

Towards Development Of A Decision Support System For Water Resource Development In Semi-Arid Micro-Catchments

IES Working Paper.The objective of the paper is to bring together, within a single holistic framework, the principle findings of the research into the physical and human aspects a study in Romwe micro-catchment in southern Zimbabwe. The framework is developed using Bayesian Belief Networks (BBNs) to identify and model the central aspects of both physical and human environment (at both the micro and macro scale), and their impacts on each other. In particular I look at the likely impact of effective catchment management (here taken to be physical and technical interventions) on the probability of livelihoods improving. BBNs offer an exciting new way of bringing together very disparate data sources within useful frameworks, which could then be used not only for decision making about development needs, but also to target better the next generation of research. For groundwater, a sizeable improvement in supply can be achieved by moving from poor to good catchment management under medium rainfall conditions, but not under poor or good rainfall. For improved surface water and improved soil moisture, it is particularly under low rainfall conditions that it is worth moving from poor to good catchment management. It is clear from the results that physical catchment management on its own is incapable of having a major impact on peoples’ livelihoods other than within a very narrow range of parameters. The suggestion is that outside this range, the decision as to whether or not to lake a physical catchment management approach has a negligible impact on water resources and even less on livelihoods. In relative terms a number of factors both extraneous (wider economy, underlying geology), and internal (community cohesion, skills levels) to the community rank equally or more highly in terms of general impact on well being.Funding for the study was provided by the Department for International Development Micro-Catchment Management Project. DFID Project No: R730

Transition-metal interactions in aluminum-rich intermetallics

The extension of the first-principles generalized pseudopotential theory (GPT) to transition-metal (TM) aluminides produces pair and many-body interactions that allow efficient calculations of total energies. In aluminum-rich systems treated at the pair-potential level, one practical limitation is a transition-metal over-binding that creates an unrealistic TM-TM attraction at short separations in the absence of balancing many-body contributions. Even with this limitation, the GPT pair potentials have been used effectively in total-energy calculations for Al-TM systems with TM atoms at separations greater than 4 AA. An additional potential term may be added for systems with shorter TM atom separations, formally folding repulsive contributions of the three- and higher-body interactions into the pair potentials, resulting in structure-dependent TM-TM potentials. Towards this end, we have performed numerical ab-initio total-energy calculations using VASP (Vienna Ab Initio Simulation Package) for an Al-Co-Ni compound in a particular quasicrystalline approximant structure. The results allow us to fit a short-ranged, many-body correction of the form a(r_0/r)^{b} to the GPT pair potentials for Co-Co, Co-Ni, and Ni-Ni interactions.Comment: 18 pages, 5 figures, submitted to PR

Heat pipe cooled heat rejection subsystem modelling for nuclear electric propulsion

NASA LeRC is currently developing a FORTRAN based computer model of a complete nuclear electric propulsion (NEP) vehicle that can be used for piloted and cargo missions to the Moon or Mars. Proposed designs feature either a Brayton or a K-Rankine power conversion cycle to drive a turbine coupled with rotary alternators. Both ion and magnetoplasmodynamic (MPD) thrusters will be considered in the model. In support of the NEP model, Rocketdyne is developing power conversion, heat rejection, and power management and distribution (PMAD) subroutines. The subroutines will be incorporated into the NEP vehicle model which will be written by NASA LeRC. The purpose is to document the heat pipe cooled heat rejection subsystem model and its supporting subroutines. The heat pipe cooled heat rejection subsystem model is designed to provide estimate of the mass and performance of the equipment used to reject heat from Brayton and Rankine cycle power conversion systems. The subroutine models the ductwork and heat pipe cooled manifold for a gas cooled Brayton; the heat sink heat exchanger, liquid loop piping, expansion compensator, pump and manifold for a liquid loop cooled Brayton; and a shear flow condenser for a K-Rankine system. In each case, the final heat rejection is made by way of a heat pipe radiator. The radiator is sized to reject the amount of heat necessary

Anisotropic Assembly of Colloidal Nanoparticles: Exploiting Substrate Crystallinity

We show that the crystal structure of a substrate can be exploited to drive the anisotropic assembly of colloidal nanoparticles. Pentanethiol-passivated Au particles of approximately 2 nm diameter deposited from toluene onto hydrogen-passivated Si(111) surfaces form linear assemblies (rods) with a narrow width distribution. The rod orientations mirror the substrate symmetry, with a high degree of alignment along principal crystallographic axes of the Si(111) surface. There is a strong preference for anisotropic growth with rod widths substantially more tightly distributed than lengths. Entropic trapping of nanoparticles provides a plausible explanation for the formation of the anisotropic assemblies we observe

Compartir l'esforç per millorar els serveis d'aigua i sanejament

La gestión comunitaria de los sistemas de suministro de agua será el enfoque primordial para conseguir los principales Objetivos de Desarrollo del Milenio en las zonas rurales. Discutimos tres aspectos específicos: el concepto de gestión comunitaria, los distintos papeles que pueden jugar los principales actores implicados en el desarrollo y la implementación de los servicios de agua y saneamiento; y la crucial necesidad de proveer capacitación utilizando técnicas participativas, de las cuales se describen algunas, apuntando a una toma de decisiones informada. Señalamos también que capacitar y estimular a los miembros de la comunidad es importante, pero aun lo es más, capacitar a los actores del nivel intermedio (gobierno local, ONG, sector privado, etc.) que son quienes respaldan y facilitan la implementación del proceso inicialmente, y luego el apoyo para asegurar la sostenibilidad del servicio proporcionado.La gestió comunitària dels sistemes de subministrament d'aigua serà l'enfocament primordial per a aconseguir els principals Objectius de Desenvolupament del Mil·lenni a les zones rurals. Discutim tres aspectes específics: el concepte de gestió comunitària, els distints papers que poden jugar els principals actors implicats en el desenvolupament i la implementació dels serveis d'aigua i sanejament; i la crucial necessitat de proveir capacitació utilitzant tècniques participatives, de les quals es descriuen algunes, apuntant a una presa de decisions informada. Assenyalem també que capacitar i estimular els membres de la comunitat és important, però fins i tot ho és més, capacitar als actors del nivell intermedi (govern local, ONG, sector privat, etc.) que són els qui donen suport i faciliten la implementació del procés inicialment, i després el suport per a assegurar la sostenibilitat del servei proporcionat.Peer Reviewe