1,318 research outputs found
Integrated engineering environments for large complex products
An introduction is given to the Engineering Design Centre at the University of Newcastle upon Tyne, along with a brief explanation of the main focus towards large made-to-order products. Three key areas of research at the Centre, which have evolved as a result of collaboration with industrial partners from various sectors of industry, are identified as (1) decision support and optimisation, (2) design for lifecycle, and (3) design integration and co-ordination. A summary of the unique features of large made-to-order products is then presented, which includes the need for integration and co-ordination technologies. Thus, an overview of the existing integration and co-ordination technologies is presented followed by a brief explanation of research in these areas at the Engineering Design Centre. A more detailed description is then presented regarding the co-ordination aspect of research being conducted at the Engineering Design Centre, in collaboration with the CAD Centre at the University of Strathclyde. Concurrent Engineering is acknowledged as a strategy for improving the design process, however design coordination is viewed as a principal requirement for its successful implementation. That is, design co-ordination is proposed as being the key to a mechanism that is able to maximise and realise any potential opportunity of concurrency. Thus, an agentoriented approach to co-ordination is presented, which incorporates various types of agents responsible for managing their respective activities. The co-ordinated approach, which is implemented within the Design Co-ordination System, includes features such as resource management and monitoring, dynamic scheduling, activity direction, task enactment, and information management. An application of the Design Co-ordination System, in conjunction with a robust concept exploration tool, shows that the computational design analysis involved in evaluating many design concepts can be performed more efficiently through a co-ordinated approach
Negative Thermal Expansion Coefficient of Graphene Measured by Raman Spectroscopy
The thermal expansion coefficient (TEC) of single-layer graphene is estimated
with temperature-dependent Raman spectroscopy in the temperature range between
200 and 400 K. It is found to be strongly dependent on temperature but remains
negative in the whole temperature range, with a room temperature value of
-8.0x10^{-6} K^{-1}. The strain caused by the TEC mismatch between graphene and
the substrate plays a crucial role in determining the physical properties of
graphene, and hence its effect must be accounted for in the interpretation of
experimental data taken at cryogenic or elevated temperatures.Comment: 17 pagese, 3 figures, and supporting information (4 pages, 3
figures); Nano Letters, 201
Dynamical Instabilities of the Randall-Sundrum Model
We derive dynamical equations to describe a single 3-brane containing fluid
matter and a scalar field coupling to the dilaton and the gravitational field
in a five dimensional bulk. First, we show that a scalar field or an arbitrary
fluid on the brane cannot evolve to cancel the cosmological constant in the
bulk. Then we show that the Randall-Sundrum model is unstable under small
deviations from the fine-tuning between the brane tension and the bulk
cosmological constant and even under homogeneous gravitational perturbations.
Implications for brane world cosmologies are discussed.Comment: 12 pages, 2 figure
Exact Solutions of Regge-Wheeler Equation and Quasi-Normal Modes of Compact Objects
The well-known Regge-Wheeler equation describes the axial perturbations of
Schwarzschild metric in the linear approximation. From a mathematical point of
view it presents a particular case of the confluent Heun equation and can be
solved exactly, due to recent mathematical developments. We present the basic
properties of its general solution. A novel analytical approach and numerical
techniques for study the boundary problems which correspond to quasi-normal
modes of black holes and other simple models of compact objects are developed.Comment: latex file, 25 pages, 4 figures, new references, new results and new
Appendix added, some comments and corrections in the text made. Accepted for
publication in Classical and Quantum Gravity, 2006, simplification of
notations, changes in the norm in some formulas, corrections in reference
Assesment of resolution and intercenter reproducibility of results of genotyping staphyloccoccus aureus by pulsed-field gel electrophoresis of SMA1 macrorestriction fragments: a multicenter study
Discrete Roles for Impulsivity and Compulsivity in Gambling Disorder
Background and Objective: Complex associations between gambling disorder (GD) and impulsivity have been identified. However, little is known regarding how compulsivity associates with different impulsivity domains in GD. In this study, we examined associations between self-reported and behavioral measures of impulsivity-assessed through the Barratt Impulsiveness Scale (BIS-11) and the Experiential Discounting Task (EDT), respectively- and compulsivity-measured using the Padua Inventory and the Wisconsin Card Sorting Test (WCST), respectively-, in an adult sample with GD (N = 132, 94 men and 38 women, ages ranging from 18 to 69 years). GD severity was assessed using the South Oaks Gambling Screen. Methods: Structural Equation Modeling was used to examine relationships between impulsivity and compulsivity measures, age, and GD severity. Results: BIS-11 non-planning and BIS-11 total scores positively correlated with GD severity. The standardized coefficients for the SEM showed direct positive contributions of BIS-11 non-planning, Padua and EDT scores to GD severity. Only participants' ages directly contributed to WCST perseverative errors, and no direct or indirect effects were found with respect to GD severity. Conclusion: The findings suggest that specific aspects of impulsivity and compulsivity contribute to GD severity. Interventions specifically targeting domains that are most relevant to GD severity may improve treatment outcomes
Assesment of resolution and intercenter reproducibility of results of genotyping staphyloccoccus aureus by pulsed-field gel electrophoresis of SMA1 macrorestriction fragments: a multicenter study
Assessment of resolution and intercenter reproducibility of results of genotyping Staphylococcus aureus by pulsed-field gel electrophoresis of SmaI macrorestriction fragments: a multicenter study
Twenty well-characterized isolates of methicillin-resistant Staphylococcus
aureus were used to study the optimal resolution and interlaboratory
reproducibility of pulsed-field gel electrophoresis (PFGE) of DNA
macrorestriction fragments. Five identical isolates (one PFGE type), 5
isolates that produced related PFGE subtypes, and 10 isolates with unique
PFGE patterns were analyzed blindly in 12 different laboratories by
in-house protocols. In several laboratories a standardized PFGE protocol
with a commercial kit was applied successfully as well. Eight of the
centers correctly identified the genetic homogeneity of the identical
isolates by both the in-house and standard protocols. Four of 12
laboratories failed to produce interpretable data by the standardized
protocol, due to technical problems (primarily plug preparation). With the
five rel
The roles and values of wild foods in agricultural systems
Almost every ecosystem has been amended so that plants and animals can be used as food, fibre, fodder, medicines, traps and weapons. Historically, wild plants and animals were sole dietary components for hunter–gatherer and forager cultures. Today, they remain key to many agricultural communities. The mean use of wild foods by agricultural and forager communities in 22 countries of Asia and Africa (36 studies) is 90–100 species per location. Aggregate country estimates can reach 300–800 species (e.g. India, Ethiopia, Kenya). The mean use of wild species is 120 per community for indigenous communities in both industrialized and developing countries. Many of these wild foods are actively managed, suggesting there is a false dichotomy around ideas of the agricultural and the wild: hunter–gatherers and foragers farm and manage their environments, and cultivators use many wild plants and animals. Yet, provision of and access to these sources of food may be declining as natural habitats come under increasing pressure from development, conservation-exclusions and agricultural expansion. Despite their value, wild foods are excluded from official statistics on economic values of natural resources. It is clear that wild plants and animals continue to form a significant proportion of the global food basket, and while a variety of social and ecological drivers are acting to reduce wild food use, their importance may be set to grow as pressures on agricultural productivity increase.</jats:p
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