3,561 research outputs found
Error analysis of a weighted least squares process to determine the lunar gravitational field
Error analysis of weighted least squares method to determine lunar gravitational fiel
Subsonic Longitudinal Performance Coefficient Extraction from Shuttle Flight Data: an Accuracy Assessment for Determination of Data Base Updates
Longitudinal performance comparisons between flight derived and predicted values are presented for the first five NASA Space Shuttle Columbia flights. Though subsonic comparisons are emphasized, comparisons during the transonic and low supersonic regions of flight are included. Computed air data information based on the remotely sensed atmospheric measurements as well as in situ Orbiter Air Data System (ADS) measurements were incorporated. Each air data source provides for comparisons versus the predicted values from the LaRC data base. Principally, L/D, C sub L, and C sub D, comparisons are presented, though some pitching moment results are included. Similarities in flight conditions and spacecraft configuration during the first five flights are discussed. Contributions from the various elements of the data base are presented and the overall differences observed between the flight and predicted values are discussed in terms of expected variations. A discussion on potential data base updates is presented based on the results from the five flights to date
Carers matter: promoting the inclusion of families within acute inpatient settings
Despite their important contributions, many carers report feeling excluded by mental health services. Admission to a psychiatric ward can be a traumatic experience for both clients and their carers. Inpatient teams play a crucial role in engaging families but they report a lack of time, skills and confidence.
This pilot study evaluated the feasibility, acceptability and potential benefits of introducing a family service across three acute wards. This comprised staff training, individual carer support and family intervention (FI). The service was found to be acceptable and feasible to implement. Family meetings on the ward increased following staff training, along with reported confidence in working with families. Following FI, significant improvements were found in carer distress, wellbeing, burden and negative illness perceptions and more carers reported having someone to confide in. The total number of ward complaints decreased following introduction of the service. Despite the difficulties implementing family work on the wards, it remains highly indicated.
This pilot has shown it is possible to implement an effective and much needed service in an acute setting
Quantitative localized proton-promoted dissolution kinetics of calcite using scanning electrochemical microscopy (SECM)
Scanning electrochemical microscopy (SECM) has been used to determine quantitatively the kinetics of proton-promoted dissolution of the calcite (101̅4) cleavage surface (from natural “Iceland Spar”) at the microscopic scale. By working under conditions where the probe size is much less than the characteristic dislocation spacing (as revealed from etching), it has been possible to measure kinetics mainly in regions of the surface which are free from dislocations, for the first time. To clearly reveal the locations of measurements, studies focused on cleaved “mirror” surfaces, where one of the two faces produced by cleavage was etched freely to reveal defects intersecting the surface, while the other (mirror) face was etched locally (and quantitatively) using SECM to generate high proton fluxes with a 25 μm diameter Pt disk ultramicroelectrode (UME) positioned at a defined (known) distance from a crystal surface. The etch pits formed at various etch times were measured using white light interferometry to ascertain pit dimensions. To determine quantitative dissolution kinetics, a moving boundary finite element model was formulated in which experimental time-dependent pit expansion data formed the input for simulations, from which solution and interfacial concentrations of key chemical species, and interfacial fluxes, could then be determined and visualized. This novel analysis allowed the rate constant for proton attack on calcite, and the order of the reaction with respect to the interfacial proton concentration, to be determined unambiguously. The process was found to be first order in terms of interfacial proton concentration with a rate constant k = 6.3 (± 1.3) × 10–4 m s–1. Significantly, this value is similar to previous macroscopic rate measurements of calcite dissolution which averaged over large areas and many dislocation sites, and where such sites provided a continuous source of steps for dissolution. Since the local measurements reported herein are mainly made in regions without dislocations, this study demonstrates that dislocations and steps that arise from such sites are not needed for fast proton-promoted calcite dissolution. Other sites, such as point defects, which are naturally abundant in calcite, are likely to be key reaction sites
Development of a Catastrophe Model for Managing the Risks of Urban Flash Flooding in Vienna
This report provides a case study examining flood risks in the city of Vienna. The purpose is to illustrate an interdisciplinary approach to flood risk analysis, combining hydrological flood risk assessment and simulation modeling with the finances of flood risk management.
Three scenarios were preliminarily identified for analysis: catastrophic flooding on a major European river (the Danube) that flows through Vienna; storm flooding due to failure of storm drainage systems; and flash flooding of a small tributary (the Vienna River) that flows into the Danube. Our initial efforts revealed that the Vienna River flash flooding scenario was a credible, significant, and tractable problem for analysis. The wealth of data available also made this scenario a useful test case for developing and illustrating interdisciplinary work, which is a significant aspect of the project activity. The focus of this report is, therefore, on the flash-flooding scenario. This report does not include discussion of the other scenarios, as they were not completed in an interdisciplinary fashion either because of lack of adequate data and models for all aspects of an interdisciplinary study, or because there were judged to be non-credible and therefore of limited use as an illustrative example.
In the course of developing an interdisciplinary approach to examining catastrophic flood risks, we found that the concept of risk used in flood management varied subtly but significantly between the disciplines contributing to the study. An important result of this study is the integration of these different disciplinary concepts of risk within a single interdisciplinary analysis. A fuller accounting for uncertainty in a way that is consistent between the component disciplines, and the appropriate distinction between various different types of uncertainty, form a second major aspect of the study. Our primary finding is that an approach that integrates perspectives on risk characteristic of the different technical disciplines contributing to this study is feasible and that it provides a useful framework for comparing the characteristics of different mitigation strategies. The results of simulations suggest alternatives for combining different mitigation measures such that the characteristics of different components of an overall strategy complement each other to lower total costs and to reduce both the likelihood and the uncertainties of catastrophic financial losses
Uncertainty and Disaster Risk Management: Modeling the Flash Flood Risk to Vienna and Its Subway System
This report describes an interdisciplinary approach to flood risk analysis and management that was developed by investigating flood risks in the city of Vienna, Austria. The purpose of the research was to analyze different policy paths (including both flood-prevention measures and risk-sharing financial provisions) in the presence of major uncertainties. A preliminary analysis resulted in the identification of two major methodological issues that needed to be resolved, namely:
-- The concept of risk used in flood management varied subtly but significantly across the disciplines contributing to the assessment.
-- Current assessment procedures did not give a full account of uncertainties and their different types.
For those reasons an approach was developed that allows the analyst: (1) to integrate the different diciplinary concepts of risk within a single interdisciplinary analysis; and (2) to take into account uncertainties in a way that not only allows their many characteristics to be distinguished but is also consistent across the component disciplines. The focus of this report is the phenomenon of flash flooing of the Vienna River. Our analysis demonstrated that, in this case, the greatest damage from flash flooding was to be expected in the Vienna city subway system. The report thus describes a detailed assessment of the flood risk to the subway and of related management measures, on which research to date has been scarce.
The results show that an approach based on catastrophe modeling and Monte Carlo simulation can not ony integrate the risk perspectives of the different technical disciplines contributing to this study but also provide a useful framework for comparing the characteristics of different mitigation strategies. The results of the simulations suggest alternatives for combining different mitigation measures to ensure complementarity among the characteristics of different components of an overall strategy, and thereby decrease total costs and reduce the likelihood and the uncertainties of catastrophic financial losses
Non-pollinator fig wasp impact on the reproductive success of an invasive fig tree: why so little?
Classical biological control agents fail to achieve an impact on their hosts for a variety of reasons and an understanding of why they fail can help shape decisions on subsequent releases. Ornamental Ficus microcarpa is a widely planted avenue fig tree that is invasive in countries where its pollinator (Eupristina verticillata) is also introduced. This tree also supports more than 20 species of non-pollinating fig wasps (NPFW) that feed in the figs and have the potential to reduce the plant’s reproduction. Odontofroggatia galili, one of the most widely introduced NPFW, has larvae that develop in galled ovules that might otherwise develop into seeds or support pollinator larvae. We examined the distribution and relative abundance of the pollinator and O. galili on F. microcarpa in China, towards the northern limit of the tree’s natural range, and in Italy where the two species have been introduced. Where they co-existed, we also recorded the impact of varying densities of O. galili on F. microcarpa seed and pollinator production. O. galili and E. verticillata displayed contrasting habitat preferences in China, with O. galili almost absent from warmer sites. O. galili abundance and sex ratios varied between the natural and introduced ranges. Figs with more O. galili contained fewer seeds and pollinator offspring, but reproduction was rarely inhibited totally. Additional species with a greater impact in the figs they occupy are needed if biocontrol of F. microcarpa is to be effective
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