Drives and benefits overview

The major technology issues for an advanced orbital transfer vehicles (OTV) engine to be used in conjunction with a space based, reusable orbit transfer vehicle are discussed. The results of the space station studies as they relate to the OTV and the ground rules and guidelines for a reusable OTV vehicle study are reviewed. The technology drives and benefit categories such as mission versatility, increased reliability or reduced cost are presented. The technology drivers and the associated benefits are covered with regard to relative significance and impact on the ongoing OTV engine technology program. It is recommended that because of the broad range of mission requirements and the long term potential cost benefits a new engine is needed for the space based reusable OTV

Dental erosion: In vitro model of wine assessor's erosion

The document attached has been archived with permission from the Australian Dental Association. An external link to the publisher’s copy is included.Background: Wine makers and assessors frequently experience severe dental erosion. The objectives of this study were to develop an in vitro model of dental erosion caused by frequent wine contact with teeth, and to use this model to assess the effectiveness of a variety of methods which might protect against this form of erosion. Methods: An initial pilot study found that riesling style wine was more erosive than champagne style, and both more than claret. Wine tasting was simulated by subjecting exposed windows of enamel and root surfaces on 50 intact, extracted human teeth to 1400 one minute exposures to white wine (pH 3.2). A variety of dental materials were applied to the exposed windows on groups of teeth prior to erosive challenge, to assess their protective ability. Results: Protective resin coatings and fluoride varnishes protected both enamel and roots against wine induced erosion. A high degree of protection was provided by APF gel, with less by NaF gel. Conclusions: It was concluded that dentists may be able to help minimise erosion resulting from frequent wine-tasting in their patients by the clinical application of one or a combination of these agents at times prior to prolonged assessment periods.Tong Bee Mok, J McIntyre and D Hun

The NASA cryogenic fluid management technology program plan

During the past three decades, NASA has been designing and using large quantities of cryogenic fluids for propulsion system propellants, coolants for experiments, and for environmental control systems. As a consequence, an erroneous conclusion has been drawn that the technology exists for using large quantities of cryogens in space for long periods of time. The attempt here is to dispel that myth and to present the technology needs that require development in order to support the NASA programs of the future. A NASA program, developed through the impetus of the Marshall Space Flight Center and the Lewis Research Center and supported by all NASA centers is outlined. The current state of the art is discussed along with specific needs for near future missions. Then, using the Space Exploration Initiative mission set, cost/benefit projections are made for the development of advanced cryogenic fluid management techniques. Earth based and space based test programs are discussed relative to the technology requirements for liquid storage, supply, and transfer for fluid transfer and advanced instrumentation

The Evolution of Clinical Practice and Supervision in the United States

Clinical practice in teacher education has evolved from an apprenticeship model to one that finds it more intertwined with collaborative arrangements with partnering public schools. We look at how this evolution has had a major impact on the effectiveness of how teachers are prepared in an ever more complex society. We also describe how instructional supervision has been intertwined with clinical practice throughout the decades

Restoration of eucalypt grassy woodland: effects of experimental interventions on ground-layer vegetation

We report on the effects of broad-scale restoration treatments on the ground layer of eucalypt grassy woodland in south-eastern Australia. The experiment was conducted in two conservation reserves from which livestock grazing had previously been removed. Changes in biomass, species diversity, ground-cover attributes and life-form were analysed over a 4-year period in relation to the following experimental interventions: (1) reduced kangaroo density, (2) addition of coarse woody debris and (3) fire (a single burn). Reducing kangaroo density doubled total biomass in one reserve, but no effects on exotic biomass, species counts or ground cover attributes were observed. Coarse woody debris also promoted biomass, particularly exotic annual forbs, as well as plant diversity in one of the reserves. The single burn reduced biomass, but changed little else. Overall, we found the main driver of change to be the favourable growth seasons that had followed a period of drought. This resulted in biomass increasing by 67%, (mostly owing to the growth of perennial native grasses), whereas overall native species counts increased by 18%, and exotic species declined by 20% over the 4-year observation period. Strategic management of grazing pressure, use of fire where biomass has accumulated and placement of coarse woody debris in areas of persistent erosion will contribute to improvements in soil and vegetation condition, and gains in biodiversity, in the future.Funding and in-kind logistic support for this project was provided by the ACT Government as part of an Australian Research Council Linkage Grant (LP0561817; LP110100126). Drafts of the manuscript were read by Saul Cunningham and Ben Macdonald

Soft-Op User Manual for Microcomputer Aided Process Control of the Oxidation Ditch Facility

This manual is intended to be used in conjunction with the program SOFT-OP. SOFT-OP was developed at the Division of Environmental Engineering, Utah State University, Logan, Utah. Funding for the program development was supplied by Tremonton City Corporation, Tremonton, Utah. Foreword: SOFT-OP has been developed for use by operators of oxidation ditch wastewater treatment plants (extended aeration activated sludge). The program serves as a useful took in daily plant operation by assisting the operator in various tasks related to process control. These tasks are grouped within the following three classifications: 1. Implementation of control parameters 2. Analysis of process characteristics 3. Data management The program is designed to run on a Radio Shack Model III microcomputer with two disk drives. Previous computer experience is not a prerequisite since the program is user-friendly and should not intimidate those operators using a computer for the first time

Responsibility for regional waste generation: A single region extended input-output analysis with uni-directional trade flows

The paper uses a regional input-output (IO) framework and data derived on waste generation by industry to examine regional accountability for waste generation. In addition to estimating a series of industry output-waste coefficients, the paper considers two methods for waste attribution but focuses first on one (trade endogenised linear attribution system (TELAS)) that permits a greater focus on private and public final consumption as the main exogenous driver of waste generation. Second, the paper uses a domestic technology assumption (DTA) to consider a regional ‘waste footprint’ where local consumption requirements are assumed to be met through domestic production.waste attribution; regional economy; input-output analysis; Wales

Teaching Physics Using Virtual Reality

We present an investigation of game-like simulations for physics teaching. We report on the effectiveness of the interactive simulation "Real Time Relativity" for learning special relativity. We argue that the simulation not only enhances traditional learning, but also enables new types of learning that challenge the traditional curriculum. The lessons drawn from this work are being applied to the development of a simulation for enhancing the learning of quantum mechanics