2,651 research outputs found
Spatial Social Networks
social networks;implementation;spatial cost topologies
Modelling and water yield assessment of Lake Sibhayi
This study has been undertaken to establish the probable causes of the almost 4 m drop in the level of Lake Sibhayi between 2001 and 2014, to assess the impact of abstractions for domestic water consumption and by commercial plantations on lake levels, and to determine what sustainable yield can be abstracted from Lake Sibhayi. From the analysis and simulations undertaken, it is concluded that the major cause of the drop in the level of Lake Sibhayi was the below-average rainfall over the period 2001 to 2011. However, while the simulation results show that the effect on lake levels of abstractions for domestic usage over this period has been negligible, they do indicate that nearly 1.4 m of the drop in lake level can be attributed to the impact of the afforestation which began in the catchment in the 1990s. A yield analysis of simulated results with historical developments in the catchment for the 65-year period of observed climate record was undertaken using both a fixed minimum allowable lake level or a maximum drop from a reference lake level as criteria for system failure. Results from simulating lake levels using the historical climate record with the area afforested and abstractions levels fixed at 2014 values indicate that no sustainable additional yield is possible because of the sustained decline in both the simulated lake levels and conceptual groundwater store, which would be environmentally, socially and ecologically unacceptable. Preliminary simulated results indicate that the removal of approximately 5 km2 of forestry is required to release 1 MCM/yr for domestic abstractions. However, these preliminary results require improved verification of input data and a review of the modelling for increased confidence in the results.Keywords: hydrology of Lake Sibhayi, lake level, abstractions, afforestation and yiel
The experimental program for high pressure gas filled radio frequency cavities for muon cooling channels
An intense beam of muons is needed to provide a luminosity on the order of 10(34) cm(-2)s(-1) for a multi-TeV collider. Because muons produced by colliding a multi-MW proton beam with a target made of carbon or mercury have a large phase space, significant six dimensional cooling is required. Through ionization cooling - the only cooling method that works within the lifetime of the muon - and emittance exchange, the desired emittances for a Higgs Factory or higher energy collider are attainable. A cooling channel utilizing gas filled radio frequency cavities has been designed to deliver the requisite cool muon beam. Technology development of these RF cavities has progressed from breakdown studies, through beam tests, to dielectric loaded and reentrant cavity designs. The results of these experiments are summarized
Networks and landscapes: a framework for setting goals and evaluating performance at the large landscape scale
The objective of large landscape conservation is to mitigate complex ecological problems through interventions at multiple and overlapping scales. Implementation requires coordination among a diverse network of individuals and organizations to integrate local‐scale conservation activities with broad‐scale goals. This requires an understanding of the governance options and how governance regimes achieve objectives or provide performance evaluation across both space and time. However, empirical assessments measuring network‐governance performance in large landscape conservation are limited. We describe a well‐established large landscape conservation network in North America, the Roundtable on the Crown of the Continent, to explore the application of a social–ecological performance evaluation framework. Systematic approaches to setting goals, tracking progress, and collecting data for feedback can help guide adaptation. Applying the established framework to our case study provides a means of evaluating the effectiveness of network governance in large landscape conservation
Resonant inelastic x-ray scattering (RIXS) spectra of magnesium diboride
Using the tight-binding linear muffin-tin orbitals method, the soft x-ray
fluorescence K-emission spectra of boron in MgB_2, excited close to the
absorption edge, are estimated. In the calculations the angle of incidence
between the direction of the incoming photon and the hexagonal axis of the
specimen is 60 degrees and 75 degrees. Comparison with experiment is possible
in the former case where good agreement is found. Furthermore, another resonant
feature below the Fermi energy is predicted for the larger angle. This feature
can be related to the excitations to the antibonding B pi-band in the
neighbourhood of the L-H line in the Brillouin zone.Comment: 4 pages with 4 figure
Kirchhoff's Loop Law and the maximum entropy production principle
In contrast to the standard derivation of Kirchhoff's loop law, which invokes
electric potential, we show, for the linear planar electric network in a
stationary state at the fixed temperature,that loop law can be derived from the
maximum entropy production principle. This means that the currents in network
branches are distributed in such a way as to achieve the state of maximum
entropy production.Comment: revtex4, 5 pages, 2 figure
Boundary Conformal Field Theory and Ribbon Graphs: a tool for open/closed string dualities
We construct and fully characterize a scalar boundary conformal field theory
on a triangulated Riemann surface. The results are analyzed from a string
theory perspective as tools to deal with open/closed string dualities.Comment: 40 pages, 7 figures; typos correcte
Engaging Long-Term Care Workers in Research: Recruitment Approaches and Participant Characteristics From a Randomized Controlled Trial to Improve COVID-19 Vaccine Confidence.
To describe and compare the recruitment methods employed in a randomized controlled trial targeting long-term care workers, and resulting participant baseline characteristics.
We used a multifaceted recruitment process to enroll long-term care workers in our 3-arm randomized controlled trial comparing 2 interventions to enhanced usual practice, for improving COVID-19 vaccine confidence and other outcomes.
Adult long-term care workers living in the United States employed within the last 2 years were invited to join the study. Participants also had to meet specific screening criteria related to their degree of worry about the vaccine and/or their vaccination status.
We used a participatory approach to engage our long-term care stakeholders in codesigning and executing a combination of recruitment methods, including targeted e-recruitment, paid e-recruitment, and in-person recruitment. Participants were screened, consented, and enrolled online. We implemented a participant verification process to ensure the integrity of our study data, and used a tailored participant management platform to manage enrollment.
We enrolled 1930 long-term care workers between May 2022 and January 2023. We met our enrollment target, despite each recruitment method having limitations. Total variable costs of approximately 25.73 for targeted e-recruitment, 64.92 for in-person methods. Our sample differed from the national population in age, gender, race/ethnicity, education, and role in long-term care. Differences were also observed between online and in-person recruitment methods.
Our results support the feasibility of enrolling a large number of long-term care workers in a randomized controlled trial to increase COVID-19 vaccine confidence. Findings build upon the evidence base for engaging this important population in research, a critical step to improving long-term care resident health and well-being. Results from our trial are anticipated in 2024
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