2,779 research outputs found

    Development of a severe local storm prediction system: A 60-day test of a mesoscale primitive equation model

    Get PDF
    The progress and problems associated with the dynamical forecast system which was developed to predict severe storms are examined. The meteorological problem of severe convective storm forecasting is reviewed. The cascade hypothesis which forms the theoretical core of the nested grid dynamical numerical modelling system is described. The dynamical and numerical structure of the model used during the 1978 test period is presented and a preliminary description of a proposed multigrid system for future experiments and tests is provided. Six cases from the spring of 1978 are discussed to illustrate the model's performance and its problems. Potential solutions to the problems are examined

    Ion implantation and low-temperature epitaxial regrowth of GaAs

    Get PDF
    Channeling and transmission electron microscopy have been used to investigate the parameters that govern the extent of damage in ion‐implanted GaAs and the crystal quality following capless furnace annealing at low temperature (∼400 °C). The implantation‐induced disorder showed a strong dependence on the implanted ion mass and on the substrate temperature during implantation. When the implantation produced a fully amorphous surface layer the main parameter governing the regrowth was the amorphous thickness. Formation of microtwins after annealing was observed when the initial amorphous layer was thicker than 400 Å. Also, the number of extended residual defects after annealing increased linearly with the initial amorphous thickness and extrapolation of that curve predicts good regrowth of very thin (<400 Å) GaAs amorphous layers produced by ion implantation. A model is presented to explain the observed features of the low‐temperature annealing of GaAs

    What is the Value of Home? NOT FOR SALE - West End Interventions

    Get PDF
    Many Australians today are image consumers. We fail to question the importance of lifestyle imagery created and promoted by Real Estate Agencies whom have no actual part in the physical creation of house, or indeed the intimate making of "home" through our experiences of place. Real Estate Markets dictate how, where, when and what we buy. Re-sale values, profit-making, and value-adding interfere with the crafting of a home over time as a tangible, individual, collaborative, and rich lived experience of dwelling. The "NOT FOR SALE" project is a response and critique of the dominance of real estate forces in West End within the context and unshakable presence of a booming inner-city property market. This proposal originated from an experimental dwelling in Avebury St., West End. This project has been fashioned over a period of several years primarily from recycled local materials, interconnected with the changing needs and spatial requirements of the occupants and project participants. The influence of property markets is of little concern in this home "making". The "NOT FOR SALE" project attempts to question and critique the purely financial value that we as a society place upon our homes. By appropriating and re-coding the Real Estate Signage typologies, we aim to provoke social commentary on the dominance of real estate forces in the West End suburb. There is a strong and rich tradition of anti-consumerist activist graffiti in West End. Activists re-code signs and property with political commentary and critique. The "NOT FOR SALE" project draws upon this tradition through our RRESign (Recodified Real Estate Signs): we aim to redress the dominant commercial forces associated with the single house/property. Collectively, at the scale of the street, these RRESigns will reflect a critique of street scale, amenity, and character. Finally, at the scale of the suburb, the network of RRESigns will reflect a critique of the idea of place making. Collectively, the aim of the "NOT FOR SALE" RRESign interventions is to highlight the idea of making and the material characteristics of dwelling that challenges the cultural value of commodified property, re-defining and prioritising the idea of "home". Conventional Real Estate signs use images and text to sell an idea of home: our proposed interventions sell nothing, and are rather celebrations of the joy of making tactile, handcrafted objects, and by extension, the making and crafting of home. The intimate and experiential understanding of home will be harnessed through the engagement of local residents. Community groups within West End such as Local Push can further disseminate the RRESign interventions. The signs will be constructed West End-specific materials (old signs purchased from inexpensive second-hand material merchant Reverse Garbage in Montague Rd.): turning post-consumer waste into objects of material beauty and social critique. Residents and community groups will be encouraged to place their RRESigns outside their properties and adjacent real estate signs, frustrating and recoding the existing For-Sale signs that currently dominate the West End street scape. The project is dependent on the support of the local residents, extending from a few signs in Avebury St. to a network of RRESigns throughout West End. A commentary on people's responses to the project will be linked to the www.apbv.com.au website. What is the value of home

    Epitaxial regrowth of thin amorphous GaAs layers

    Get PDF
    Channeling and transmission electron microscopy have been used to investigate the parameters that govern the crystal quality following capless funace annealing at low temperature (~ 400 °C) in ion-implanted GaAs. From the results obtained, we concluded that the crystal quality after annealing depends strongly on the thickness of the amorphous layer generated by ion implantation and the number of residual defects increases linearly with the thickness of the implanted layer. Single-crystal regrowth free of defects detectable by megaelectron volt He + channeling was achieved for a very thin amorphous layer (<~ 400 Å)

    The comparative evaluation of ERTS-1 imagery for resource inventory in land use planning

    Get PDF
    The author has identified the following significant results. Multidiscipline team interpretation and mapping of resources for Crook County is nearly complete on 1:250,000 scale enlargements of ERTS-1 imagery. Maps of geology, landforms, soils and vegetation-land use are being interpreted to show limitations, suitabilities and geologic hazards for land use planning. Mapping of lineaments and structures from ERTS-1 imagery has shown a number of features not previously mapped in Oregon. A timber inventory of Ochoco National Forest has been made. Inventory of forest clear-cutting practices has been successfully demonstrated with ERTS-1 color composites. Soil tonal differences in fallow fields shown on ERTS-1 correspond with major soil boundaries in loess-mantled terrain. A digital classification system used for discriminating natural vegetation and geologic materials classes has been successful in separation of most major classes around Newberry Cauldera, Mt. Washington and Big Summit Prairie. Computer routines are available for correction of scanner data variations; and for matching scales and coordinates between digital and photographic imagery. Methods of Diazo film color printing of computer classifications and elevation-slope perspective plots with computer are being developed
    corecore