Optioneering analysis for connecting Dogger Bank offshore wind farms to the GB electricity network

This paper outlines possibilities for connecting 2.4 GW of power from two separate wind farms at Dogger Bank in the North Sea to the GB transmission system in Great Britain. Three options based on HVDC with Voltage Source Converters (VSC HVDC) are investigated: two separate point-to-point connections, a four-terminal multi-terminal network and a four-terminal network with the addition of an AC auxiliary cable between the two wind farms. Each option is investigated in terms of investment cost, controllability and reliability against expected fault scenarios. The paper concludes that a VSC-HVDC point-to-point connection is the cheapest option in terms of capital cost and has the additional advantage that it uses technology that is commercially available. However, while multi-terminal connections are more expensive to build it is found that they can offer significant advantages over point to point systems in terms of security of supply and so could offer better value for money overall. A multi-terminal option with an auxiliary AC connection between wind farms is found to be lower cost than a full multi-terminal DC grid option although the latter network would offer ability to operate at greater connection distances between substations

The evolution of galaxy groups and of galaxies therein

Properties of groups of galaxies depend sensitively on the algorithm for group selection, and even the most recent catalogs of groups built from redshift-space selection should suffer from projections and infalling galaxies. The cosmo-dynamical evolution of groups from initial Hubble expansion to collapse and virialization leads to a fundamental track (FT) in virial-theorem-M/L vs crossing time. The increased rates of mergers, both direct and after dynamical friction, in groups relative to clusters, explain the higher fraction of elliptical galaxies at given local number density in X-ray selected groups, relative to clusters, even when the hierarchical evolution of groups is considered. Galaxies falling into groups and clusters should later travel outwards to typically 2 virial radii, which is somewhat less than the outermost radius where observed galaxy star formation efficiencies are enhanced relative to field galaxies of same morphological type. An ongoing analysis of the internal kinematics of X-ray selected groups suggests that the radial profiles of line of sight velocity dispersion are consistent with isotropic NFW distributions for the total mass density, with higher (lower) concentrations than LambdaCDM predictions in groups of high (low) mass. The critical mass, at M200 ~ 10^13 M_sun is consistent with possible breaks in the X-ray luminosity-temperature and Fundamental Plane relations. The internal kinematics of groups indicate that the M-T relation of groups should agree with that extrapolated from clusters with no break at the group scale. The analyses of observed velocity dispersion profiles and of the FT both suggest that low velocity dispersion groups (compact and loose, X-ray emitting or undetected) are quite contaminated by chance projections.Comment: Invited review, ESO workshop "Groups of Galaxies in the Nearby Universe", held in Santiago, Chile, 5-9 December 2005, ed. I. Saviane, V. Ivanov & J. Borissova, 16 page

Evaluating Microcounseling Training

An evaluation research design was developed as an attempt to provide a more satisfactory approach to microcounseling training program evaluation. Trainee performance was measured three times during a counseling practicum, with microcounseling training occurring between the second and third observations. Trainee performance was compared to a predetermined standard for counselor behavior. Results were analyzed for both the differences between observations, and the degree of similarity to the model. Counseling behavior of trainees after microcounseling training was significantly different from their behavior prior to the training. After training they were more like the standard. The trainees performed less like the standard after some counseling experience, but before receiving microcounseling training.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66901/2/10.1177_0193841X8300700206.pd

Extrapolating SMBH correlations down the mass scale: the case for IMBHs in globular clusters

Empirical evidence for both stellar mass black holes M_bh<10^2 M_sun) and supermassive black holes (SMBHs, M_bh>10^5 M_sun) is well established. Moreover, every galaxy with a bulge appears to host a SMBH, whose mass is correlated with the bulge mass, and even more strongly with the central stellar velocity dispersion sigma_c, the `M-sigma' relation. On the other hand, evidence for "intermediate-mass" black holes (IMBHs, with masses in the range 1^2 - 10^5 M_sun) is relatively sparse, with only a few mass measurements reported in globular clusters (GCs), dwarf galaxies and low-mass AGNs. We explore the question of whether globular clusters extend the M-sigma relationship for galaxies to lower black hole masses and find that available data for globular clusters are consistent with the extrapolation of this relationship. We use this extrapolated M-sigma relationship to predict the putative black hole masses of those globular clusters where existence of central IMBH was proposed. We discuss how globular clusters can be used as a constraint on theories making specific predictions for the low-mass end of the M-sigma relation.Comment: 14 pages, 3 figures, accepted for publication in Astrophysics and Space Science; fixed typos and a quote in Sec.

Search for Spontaneous Nucleation of Magnetic Flux During Rapid Cooling of YBCO films Through Tc

We describe an experimental search for spontaneous formation of flux lines during a rapid quench of thin YBaCuO films through Tc. This effect is expected according to the Kibble-Zurek mechanism of a creation of topological defects of the order parameter during a symmetry breaking phase transition. Spontaneously formed vortices were previously observed in superfluid 3He, while a similar experiment in superfluid 4He gave negative results. Using a high Tc SQUID, we measured both the magnetic flux in the sample during a quench with a sensitivity of 20 phi-0/cm^2, and the field noise which one would expect from flux lines pinned in the film. The sensitivity was sufficient to detect spontaneous flux at a level corresponding to 10^(-3) of the prediction. Within our resolution, we saw no evidence for this effect.Comment: Manuscript and 4 figure

A weakly stable algorithm for general Toeplitz systems

We show that a fast algorithm for the QR factorization of a Toeplitz or Hankel matrix A is weakly stable in the sense that R^T.R is close to A^T.A. Thus, when the algorithm is used to solve the semi-normal equations R^T.Rx = A^Tb, we obtain a weakly stable method for the solution of a nonsingular Toeplitz or Hankel linear system Ax = b. The algorithm also applies to the solution of the full-rank Toeplitz or Hankel least squares problem.Comment: 17 pages. An old Technical Report with postscript added. For further details, see http://wwwmaths.anu.edu.au/~brent/pub/pub143.htm

Mercury concentrations in two “great waters”

Although many sources of Hg to surface waters have been identified including atmospheric deposition, resuspension of contaminated sediments, and direct discharges, there are very few recent data on ambient concentrations in the large lakes. Thus, an investigation of Hg concentrations in Lake Champlain and Lake Michigan was completed in the summer of 1993. Three depths of water including the microlayer, 30 cm below the surface, and 1 m below the thermocline were collected for each sampling event using ultra-clean techniques. All samples were processed in the field for dissolved and particulate fractions in a portable plastic enclosure equipped with a HEPA filter, and then analyzed by dual amalgamation and cold vapor atomic fluorescence spectroscopy in a Class 100 clean room at the University of Michigan. In addition, samples were analyzed for other trace metals by ICP-MS. Results from the two field investigations include the following: (1) On average, Lake Michigan water samples had higher concentrations of Hg than Lake Champlain; (2) There was no consistent pattern of Hg concentrations in the water column; (3) There was variability in the concentrations of Hg from the same depths over consecutive sampling periods. This paper discusses these results, and examines the relationship between the patterns in mercury concentrations and other physical and chemical data collected during the investigation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43914/1/11270_2005_Article_BF01189709.pd

Imagination, Hope and the Migrant Journey : Iraqi Asylum Seekers Looking for a Future in Europe

Europe received an unprecedented number of asylum seekers in 2015. This article examines Iraqi asylum seekers who journeyed through Europe in search of an idealized version of Finland, which they had imagined based on word-of-mouth and social media information. Through cognitive migration, the act of pre-experiencing futures in different locations, Finland was seen to offer both subjective hope of personal growth and advancement and objective hope of safety and physical security. This hope motivated them to embark on a journey of 6,000 kilometers to the European North. Based on interview data and relevant studies, the article concludes that hope of a better, imagined future abroad acts as a powerful magnet for persons with poor prospects in their countries of origin. Hope is a kind of critical emotion strongly shaped by beliefs and real-time opportunities; and as such, beliefs are notoriously difficult to change. Imagination, therefore, should not be overlooked when planning and implementing migration policies.Europe received an unprecedented number of asylum seekers in 2015. This article examines Iraqi asylum seekers who journeyed through Europe in search of an idealized version of Finland, which they had imagined based on word-of-mouth and social media information. Through cognitive migration, the act of pre-experiencing futures in different locations, Finland was seen to offer both subjective hope of personal growth and advancement and objective hope of safety and physical security. This hope motivated them to embark on a journey of 6,000 kilometers to the European North. Based on interview data and relevant studies, the article concludes that hope of a better, imagined future abroad acts as a powerful magnet for persons with poor prospects in their countries of origin. Hope is a kind of critical emotion strongly shaped by beliefs and real-time opportunities; and as such, beliefs are notoriously difficult to change. Imagination, therefore, should not be overlooked when planning and implementing migration policies.Peer reviewe

Field Measurements of Terrestrial and Martian Dust Devils

Surface-based measurements of terrestrial and martian dust devils/convective vortices provided from mobile and stationary platforms are discussed. Imaging of terrestrial dust devils has quantified their rotational and vertical wind speeds, translation speeds, dimensions, dust load, and frequency of occurrence. Imaging of martian dust devils has provided translation speeds and constraints on dimensions, but only limited constraints on vertical motion within a vortex. The longer mission durations on Mars afforded by long operating robotic landers and rovers have provided statistical quantification of vortex occurrence (time-of-sol, and recently seasonal) that has until recently not been a primary outcome of more temporally limited terrestrial dust devil measurement campaigns. Terrestrial measurement campaigns have included a more extensive range of measured vortex parameters (pressure, wind, morphology, etc.) than have martian opportunities, with electric field and direct measure of dust abundance not yet obtained on Mars. No martian robotic mission has yet provided contemporaneous high frequency wind and pressure measurements. Comparison of measured terrestrial and martian dust devil characteristics suggests that martian dust devils are larger and possess faster maximum rotational wind speeds, that the absolute magnitude of the pressure deficit within a terrestrial dust devil is an order of magnitude greater than a martian dust devil, and that the time-of-day variation in vortex frequency is similar. Recent terrestrial investigations have demonstrated the presence of diagnostic dust devil signals within seismic and infrasound measurements; an upcoming Mars robotic mission will obtain similar measurement types

Ambient levels and dry deposition fluxes of mercury to Lakes Huron, Erie and St. Clair

Ambient concentrations and dry deposition fluxes of Hg in the gas and particle phase to Lakes St. Clair, Erie and Huron were estimated with a hybrid receptor-deposition model (HRD). The ambient gas and particulate phase Hg concentrations were predicted to vary by a factor of 12 to 18 during the transport of air masses traversing the lakes. The ensemble average deposition fluxes of fine particle Hg ranged from 7 pg/m 2 -h to 15.3 pg/m 2 -h over Lake St. Clair, 0.5 to 4.2 pg/m 2 -h over Lake Huron and 5.1 to 20.6 pg/m 2 -h over Lake Erie. The deposition flux of coarse particle Hg was in the range of 50 to 84 pg/m 2 -h over Lake St. Clair, 4.7 to 24.2 pg/m 2 -h over Lake Huron and 5.1 to 20.6 pg/m 2 -h over Lake Erie. Gaseous Hg volatilized at a rate of 0.21 to 0.52 ng/m 2 -h from Lake Huron and 0.13 to 0.36 from Lake Erie. Gas phase Hg was deposited at a rate of 5.9 ng/m 2 -h and/or volatilized at a rate of 0.5 ng/m 2 -h from Lake St. Clair depending upon the location of the sampling site used in the HRD model. The effect of meteorological conditions, particle size distributions and type and location of the sampling sites played an important role in the transfer of atmospheric Hg to and/or from the lakes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43911/1/11270_2005_Article_BF01189666.pd