Recent results from zero g cargo handling studies

Cargo handling, transfer, and stowage under weightlessness conditions of space shuttl

Macroinvertebrates, Heavy Metals and PAHs in Urban Watercourses

Good quality stream water and sediments are crucial for the support of healthy stream flora and fauna but urban runoff degrades watercourses leaving a legacy of pollution in the stream sediments. The sediment pollution load influences the development of macroinvertebrates which, as the lowest member of the food chain, influences the whole ecological structure. This review focuses on defining the sources and impacts of zinc, nickel, copper and oil derivative polycyclic aromatic hydrocarbon (PAH) contaminants in urban runoff. The impact of pollutants as measured by laboratory, field and modelling procedures are considered. Land use, position and connectivity of the runoff and sediment are seen to have an effect on the ecological integrity of the watercourse but case examples are sparse. The literature indicates that while reduced species diversity has been identified at a number of sites the dynamics are not well understood nor well modelled. These results are compared with field evidence from a study of 62 headwater streams with urban industrial and motorway land uses. From the review and field results it is evident that there is still an important need for process-based field measurements of urban water quality parameters. Forecasting the ecological status of watercourses would seem to benefit from data on sediment chemistry that considers the interaction effects of metals and PAHs

Analysis of combinations of altitude and descent rate for safe abort during terminal phase of lunar landing

Boundary curve for combinations of altitude and descent rate for safe abort during terminal phase of lunar landin

NASA Aircraft Controls Research, 1983

The workshop consisted of 24 technical presentations on various aspects of aircraft controls, ranging from the theoretical development of control laws to the evaluation of new controls technology in flight test vehicles. A special report on the status of foreign aircraft technology and a panel session with seven representatives from organizations which use aircraft controls technology were also included. The controls research needs and opportunities for the future as well as the role envisioned for NASA in that research were addressed. Input from the panel and response to the workshop presentations will be used by NASA in developing future programs

Investigating the influence of heavy metals on macro-invertebrate assemblages using Partial Cononical Correspondence Analysis (pCCA)

International audienceThis paper defines the spectrum of impairment to stream macroinvertebrates arising from urban runoff. Field sampling of stream sediments at 62 sites across Yorkshire, UK was used to investigate the influence of heavy metals and habitat on macroinvertebrate family distribution using partial Canonical Correspondence Analysis (pCCA). Increasing urbanization and trafficking was associated with increasing levels of metal pollution but, even when traffic is light, family numbers can be reduced by 50%. Industrial areas and motorway runoff depress macroinvertebrate numbers but drainage from streets with no off-road parking in residential areas can have similar impacts. The heavy metals in the sediment accounted for approximately 24% of the variation in macroinvertebrate community composition while the physical habitat variables used in RIVPACS (River InVertebrate Prediction And Classification System) (Wright, 2000) accounted for an additional 30%. Zinc and nickel were the main metal influences regardless of the time of sampling; at these sites copper is less than critical. Results agree with those reported in other studies in which families mainly from the orders Ephemeroptera (mayfly), Plecoptera (stonefly) and Tricoptera (caddisfly) displayed metal sensitivity in that they were absent from metal polluted streams. However, within each of these orders, a continuum of sensitivity is evident: this highlights the risks of generalising on orders rather than using family or indeed species data. Keywords: macroinvertebrates, heavy metals, urban streams, tolerance, sensitivit

Causes, Consequences and Prevention of Refrigeration Fires in Residential Dwellings

There are around 300 residential dwelling fires in Great Britain each year where a fridge or freezer is cited as the cause. A number of these incidents have resulted in injuries/fatalities and produced significant levels of property damage. This paper examines the causes and consequences of refrigeration fires in residential dwelling fires in Great Britain (London and England) and the evidence collected via fire investigation of residential dwelling fires involving fridges or freezers. Analysis of the data collected from these fires suggests that, once ignition occurs, fires started by faults in fridge/freezers are more likely to spread beyond both the appliance and the room of origin, and tend to cause more damage than fires started by the other types of white goods appliance (washing machine, dishwasher or tumble dryer). A number of common failure modes leading to ignition in domestic refrigeration fires, along with specific fire escalation and spread mechanism are identified. Based upon the information obtained from fire investigations and a comparison between the design and construction of refrigeration appliances used in Great Britain and USA, a number of recommendations are suggested which could be used to help reduce the risk of domestic refrigeration fires

Orbital Cargo Transfer Simulation

Future space operations will require transfers of a large variety of cargo under both intravehicular and extravehicular conditions. In order to determine the techniques, human factor considerations, assistive devices, package limitations, training procedures, and so forth related to the cargo transfer problem, extensive ground-based simulation is required. To date, several zero- and reduced-gravity simulation techniques have been developed and utilized. All of these techniques have both limitations and definite areas of application. Two of these techniques, water-immersion and zero-g aircraft, are considered usable for cargo transfer simulation. However, the results being obtained using the techniques differ substantially. The reasons for disagreement are to be found in the limitations of the techniques and how they are considered. The purpose of this paper is to provide a comparison of zero-g aircraft .and water-immersion simulation, and to discuss various techniques which can be used to minimize the limitations associated with water immersion

Effect of erosion on water infiltration rates

The information in this bulletin is condensed from a thesis submitted by the senior author to the Graduate School of the University of Missouri in partial fulfillment of the requirements for the degree of Master of Science--P. [2].Digitized 2007 AES.Includes bibliographical references (pages 35-36)

The effect of bedrest on various parameters of physiological function. part xii- the effect of bedrest on bone mass and calcium balance

Bed rest effect on various parameters of physiological functions - bone mass and calcium balanc

Gauge Threshold Corrections for Local String Models

We study gauge threshold corrections for local brane models embedded in a large compact space. A large bulk volume gives important contributions to the Konishi and super-Weyl anomalies and the effective field theory analysis implies the unification scale should be enhanced in a model-independent way from M_s to R M_s. For local D3/D3 models this result is supported by the explicit string computations. In this case the scale R M_s comes from the necessity of global cancellation of RR tadpoles sourced by the local model. We also study D3/D7 models and discuss discrepancies with the effective field theory analysis. We comment on phenomenological implications for gauge coupling unification and for the GUT scale.Comment: 30 pages; v2: references added, minor typos correcte