198 research outputs found
A hybrid parametrical wave prediction model
The development of a numerical wave prediction model incorporating a parametrical wind-sea model and a characteristic swell model is described. The parametrical model is an extension of an earlier two-parameter model to the full five Jonswap spectral parameters. An application is presented in which the model is used to hindcast severe wave conditions in the North Sea as part of an engineering study to define long-term extreme wave statistics for the area. The limitations of the model and the needs for future research are discussed
Inversion of Randomly Corrugated Surfaces Structure from Atom Scattering Data
The Sudden Approximation is applied to invert structural data on randomly
corrugated surfaces from inert atom scattering intensities. Several expressions
relating experimental observables to surface statistical features are derived.
The results suggest that atom (and in particular He) scattering can be used
profitably to study hitherto unexplored forms of complex surface disorder.Comment: 10 pages, no figures. Related papers available at
http://neon.cchem.berkeley.edu/~dan
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Computational Studies in Molecular Geochemistry and Biogeochemistry
The ability to predict the transport and transformations of contaminants within the subsurface is critical for decisions on virtually every waste disposal option facing the Department of Energy (DOE), from remediation technologies such as in situ bioremediation to evaluations of the safety of nuclear waste repositories. With this fact in mind, the DOE has recently sponsored a series of workshops on the development of a Strategic Simulation Plan on applications of high perform-ance computing to national problems of significance to the DOE. One of the areas selected for application was in the area of subsurface transport and environmental chemistry. Within the SSP on subsurface transport and environmental chemistry several areas were identified where applications of high performance computing could potentially significantly advance our knowledge of contaminant fate and transport. Within each of these areas molecular level simulations were specifically identified as a key capability necessary for the development of a fundamental mechanistic understanding of complex biogeochemical processes. This effort consists of a series of specific molecular level simulations and program development in four key areas of geochemistry/biogeochemistry (i.e., aqueous hydrolysis, redox chemistry, mineral surface interactions, and microbial surface properties). By addressing these four differ-ent, but computationally related, areas it becomes possible to assemble a team of investigators with the necessary expertise in high performance computing, molecular simulation, and geochemistry/biogeochemistry to make significant progress in each area. The specific targeted geochemical/biogeochemical issues include: Microbial surface mediated processes: the effects of lipopolysacchardies present on gram-negative bacteria. Environmental redox chemistry: Dechlorination pathways of carbon tetrachloride and other polychlorinated compounds in the subsurface. Mineral surface interactions: Describing surfaces at multiple scales with realistic surface functional groups Aqueous Hydrolysis Reactions and Solvation of Highly Charged Species: Understanding the formation of polymerized species and ore formation under extreme (Hanford Vadose Zone and geothermo) conditions. By understanding on a fundamental basis these key issues, it is anticipated that the impacts of this research will be extendable to a wide range of biogeochemical issues. Taken in total such an effort truly represents a “Grand Challenge” in molecular geochemistry and biogeochemistry
Evaluating a team-based approach to research capacity building using a matched-pairs study design
Background: There is a continuing need for research capacity building initiatives for primary health care professionals. Historically strategies have focused on interventions aimed at individuals but more recently theoretical frameworks have proposed team-based approaches. Few studies have evaluated these new approaches. This study aims to evaluate a team-based approach to research capacity building (RCB) in primary health using a validated quantitative measure of research capacity in individual, team and organisation domains
Whose responsibility is adolescent's mental health in the UK? The perspectives of key stakeholders
The mental health of adolescents is a salient contemporary issue attracting the attention of policy makers in the UK and other
countries. It is important that the roles and responsibilities of agencies are clearly established, particularly those positioned
at the forefront of implementing change. Arguably, this will be more efective if those agencies are actively engaged in the
development of relevant policy. An exploratory study was conducted with 10 focus groups including 54 adolescents, 8 mental
health practitioners and 16 educational professionals. Thematic analysis revealed four themes: (1) mental health promotion
and prevention is not perceived to be a primary role of a teacher; (2) teachers have limited skills to manage complex
mental health difculties; (3) adolescents rely on teachers for mental health support and education about mental health; and
(4) the responsibility of parents for their children’s mental health. The research endorses the perspective that teachers can
support and begin to tackle mental well-being in adolescents. However, it also recognises that mental health difculties can
be complex, requiring adequate funding and support beyond school. Without this support in place, teachers are vulnerable
and can feel unsupported, lacking in skills and resources which in turn may present a threat to their own mental well-being
Mononuclear and Mixed-Metal Dimethyltin Pacman Complexes of a Schiff-Base Pyrrole Macrocycle
The synthesis of the dialkyltin complex [SnMe2-(H2L)] of an octadentate Schiff-base pyrrol macrocycle is described in which the gross Pacman geometry enforces structural discrimination between the two methyl groups. The presence of the metal-free compertment engenders the formation of mixed-metal Sn-Fe and Sn-Zn complexes in which the macrocyclic cleft has distorted considerably upon the introduction of the transition metal cation.</p
The impact of ENSO on Southern African rainfall in CMIP5 ocean atmosphere coupled climate models
We study the ability of 24 ocean atmosphere global coupled models from the Coupled Model Intercomparison Project 5 (CMIP5) to reproduce the teleconnections between El Niño Southern Oscillation (ENSO) and Southern African rainfall in austral summer using historical forced simulations, with a focus on the atmospheric dynamic associated with El Niño. Overestimations of summer rainfall occur over Southern Africa in all CMIP5 models. Abnormal westward extensions of ENSO patterns are a common feature of all CMIP5 models, while the warming of the Indian Ocean that happens during El Niño is not correctly reproduced. This could impact the teleconnection between ENSO and Southern African rainfall which is represented with mixed success in CMIP5 models. Large-scale anomalies of suppressed deep-convection over the tropical maritime continent and enhanced convection from the central to eastern Pacific are correctly simulated. However, regional biases occur above Africa and the Indian Ocean, particularly in the position of the deep convection anomalies associated with El Niño, which can lead to the wrong sign in rainfall anomalies in the northwest part of South Africa. From the near-surface to mid-troposphere, CMIP5 models underestimate the observed anomalous pattern of pressure occurring over Southern Africa that leads to dry conditions during El Niño years
Web Content Analysis: Expanding the Paradigm
Are established methods of content analysis (CA) adequate to analyze web content, or should new methods be devised to address new technological developments? This chapter addresses this question by contrasting narrow and broad interpretations of the concept of web content analysis. The utility of a broad interpretation that subsumes the narrow one is then illustrated with reference to research on weblogs (blogs), a popular web format in which features of HTML documents and interactive computer-mediated communication converge. The chapter concludes by proposing an expanded Web Content Analysis (WebCA) paradigm in which insights from paradigms such as discourse analysis and social network analysis are operationalized and implemented within a general content analytic framework
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