2,629 research outputs found
Pilot Survey – Queue Management Strategies for Urban Traffic Control Systems
BACKGROUND
1.1 Advances in traffic signal optimization have produced increases in the capacity of urban road networks, but recent growth in demand has meant that many junctions operate at or above saturation levels. Delay costs increase dramatically when queues extend to block upstream junctions and queue management strategies are now required to ensure that local traffic signals operate effectively when oversaturated conditions occur.
1.2 The aims of this SERC-funded "Queue Management Strategies" project are as follows:
(a) To generalise the strategies for queue management that were developed and tested empirically in Bangkok (See ITS WP 249 and WP 251);
(b) To develop a computer graphics model to represent queue propagation;
(c) To test the strategies' applicability and performance in UK networks;
(d) To investigate their incorporation into standard signal optimization programs
Implementation of a Virtual Journal Club in a Clinical Nursing Setting
Healthcare practice is increasingly focused on delivering care that is based on published research evidence. Staff development nurses can institute journal clubs to teach nursing staff critical appraisal of research articles and ways to translate research findings into clinical practice. Unfortunately, attending meetings regularly is often a challenge for nurses, and relatively few have the knowledge and expertise to adequately critique research articles. One way to bridge the limitations of accessibility and limited research expertise of journal club members is to establish a virtual journal club. This article describes one hospital\u27s experience with developing a virtual journal club
Modelling Organic Dairy Production Systems
In this study, a large number of organic dairy production strategies were compared in terms of physical and financial performance through the integrated use of computer simulation models and organic case study farm data. Production and financial data from three organic case study farms were used as a basis for the modelling process to ensure that the modelled systems were based on real sets of resources that might be available to a farmer. The case study farms were selected to represent a range of farming systems in terms of farm size, concentrate use and location. This paper describes the process used to model the farm systems: the integration of the three models used and the use of indicators to assess the modelled farm systems in terms of physical sustainability and financial performance
Anisotropic glass-like properties in tetragonal disordered crystals
The low temperature acoustic and thermal properties of amorphous, glassy
materials are remarkably similar. All these properties are described
theoretically with reasonable quantitative accuracy by assuming that the
amorphous solid contains dynamical defects that can be described at low
temperatures as an ensemble of two-level systems (TLS), but the deep nature of
these TLSs is not clarified yet. Moreover, glassy properties were found also in
disordered crystals, quasicrystals, and even perfect crystals with a large
number of atoms in the unit cell. In crystals, the glassy properties are not
universal, like in amorphous materials, and also exhibit anisotropy. Recently
it was proposed a model for the interaction of two-level systems with arbitrary
strain fields (Phys. Rev. B 75, 64202, 2007), which was used to calculate the
thermal properties of nanoscopic membranes at low temperatures. The model is
also suitable for the description of anisotropic crystals. We describe here the
results of the calculation of anisotropic glass-like properties in crystals of
various lattice symmetries, emphasizing the tetragonal symmetry.Comment: 5 pages, no figure
Elastic response of [111]-tunneling impurities
We study the dynamic response of a [111] quantum impurity, such as lithium or
cyanide in alkali halides, with respect to an external field coupling to the
elastic quadrupole moment. Because of the particular level structure of a
eight-state system on a cubic site, the elastic response function shows a
biexponential relaxation feature and a van Vleck type contribution with a
resonance frequency that is twice the tunnel frequency . This
basically differs from the dielectric response that does not show relaxation.
Moreover, we show that the elastic response of a [111] impurity cannot be
reduced to that of a two-level system. In the experimental part, we report on
recent sound velocity and internal friction measurements on KCl doped with
cyanide at various concentrations. At low doping (45 ppm) we find the dynamics
of a single [111] impurity, whereas at higher concentrations (4700 ppm) the
elastic response rather indicates strongly correlated defects. Our theoretical
model provides a good description of the temperature dependence of
and at low doping, in particular the relaxation peaks, the absolute
values of the amplitude, and the resonant contributions. From our fits we
obtain the value of the elastic deformation potential eV.Comment: 19 pages, 5 figure
Scattering of phonons on two-level systems in disordered crystals
We calculate the scattering rates of phonons on two-level systems in
disordered trigonal and hexagonal crystals. We apply a model in which the
two-level system, characterized by a direction in space, is coupled to the
strain field of the phonon via a tensor of coupling constants. The structure of
the tensor of coupling constants is similar to the structure of the tensor of
elastic stiffness constants, in the sense that they are determined by the same
symmetry transformations. In this way, we emphasize the anisotropy of the
interaction of elastic waves with the ensemble of two-level systems in
disordered crystals. We also point to the fact that the ratio
has a much broader range of allowed values in disordered
crystals than in isotropic solids.Comment: 5 pages, no figure
INTERACT: FAIR Data from Cold Region Research Stations
The International Network for Terrestrial Research and Monitoring in the Arctic (INTERACT) is a EU Horizon 2020 funded infrastructure project seeking to provide a geographically comprehensive infrastructure for arctic and high altitude research stations. The overall objective of the project is to facilitate the identification of environmental and ecological change, the understanding of change and prediction of future changes. The second phase of the project commenced October 2016. One of the major tasks in the project is to create a coordinated and unified data management approach that would optimize potential future reuse, sharing, and guarantee data and metadata stewardship and preservation. Herein we present the preliminary plan to carry out this objective by focusing on four principles: Findability, Accessibility, Interoperability, and Reusability (FAIR).
Currently, 79 sites in arctic and northern alpine areas are part of the INTERACT network. Data collected at these stations are from different scientific disciplines, e.g. geo-sciences (including the atmosphere and cryosphere), hydrology, biology, ecology, and to some extent anthropology. These data are generated as a result of monitoring activities or short term projects. A survey of data management practices in INTERACT was conducted at the beginning of the project. The main finding is that data management at INTERACT stations is highly heterogeneous. In order to establish a unified view on all the data collected by INTERACT stations and through this show the benefit of INTERACT, interoperability at the discovery metadata and data levels is required. The first step towards this is taken through a Data Management Plan (DMP) which is identifying the general principles, common standards to apply and data dissemination principles.
The DMP for INTERACT is a living document oriented towards international data management frameworks like World Meteorological Organization Information System (utilized by e.g. Global Cryosphere Watch, Global Atmosphere Watch), and aligned with the activities of the International Arctic Science Committee (IASC) and Sustaining Arctic Observing Network (SAON) Arctic Arctic Data Committee (ADC). INTERACT emphasizes long term data preservation (as promoted by ICSU-WDS), community driven best practices (e.g. RDA), and the principles outlined by the ADC, that promote free, ethically open, sustained, and timely access to Arctic data. This approach should provide easy integration with the H2020 Open Research Data Pilot, and ensure data access to a variety of stakeholders (e.g. ESA DUE, GlobPermafrost, etc.).
The initial data management effort focuses on discovery metadata, utilizing internationally accepted standards, protocols and vocabularies, ensuring the interoperability with international systems and frameworks, and the preservation of scientific legacy. Datasets will be documented using the Global Change Master Directory/Directory Interchange Format or ISO19115 standards. To provide interoperability at the data level, long term archival of data across different national repositories with long term mandates in self-explaining file formats (e.g. NetCDF, HDF/HDF5) is envisioned eventually.
Therefore, our goal is to establish a unified approach to metadata and data generated by stations in the INTERACT network. This will be beneficial for scientific purposes, but also for monitoring activities. The latter is particularly important as Arctic monitoring to a large degree rely on the effort of the scientific community
The challenge of modelling nitrogen management at the field scale : simulation and sensitivity analysis of N2O fluxes across nine experimental sites using DailyDayCent
Peer reviewedPublisher PD
Production of compact plants by overexpression of AtSHI in the ornamental Kalanchoe
Growth retardation is an important breeding aim and an essential part of horticultural plant production Here, the potential of transferring the Arabidopsis short internode (shi) mutant phenotype was explored by expressing the AtSHI gene in the popular ornamental plant Kalanchoe A 35S-AtSHI construct was produced and transferred into eight genetically different cultivars of Kalanchoe by Agrobacterium tumefaciens The resulting transgenic plants showed dwarfing phenotypes like reduced plant height and diameter, and also more compact inflorescences, as a result of increased vegetative height The shi phenotype was stable over more than five vegetative subcultivations Compared with Arabidopsls, the ectopic expression of AtSHI in Kalanchoe showed several differences None of the Kalanchoe SHI-lines exhibited alterations in leaf colour or morphology, and most lines were not delayed in flowering Moreover, continuous treatment of lines delayed in flowering with low concentrations of gibberellins completely restored the time of flowering These features are very Important as a delay in flowering would increase plant production costs significantly. The effect of expression controlled by the native Arabidopsls SHI promoter was also investigated in transgenic Kalanchoe and resulted in plants with a longer flowering period Two AtSHI like genes were identified in Kalanchoe indicating a widespread presence of this transcription factor These findings are important because they suggest that transformation with the AtSHI gene could be applied to several species as a tool for growth retardation, and that this approach could substitute the use of conventional chemical growth regulation in plant productio
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