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This article is a description of how GIS functionality is used within a Ship Information System (SIS), as carried out by the Danish Institute for Fisheries Research (DIFRES). This particular [...]

Byline: Brian Cowan I remember discussing Twitter with a colleague at an academic conference back in 2009. 'We have to start using it,' he told me. I asked why. His [...]

Superfluidity is a manifestation of the operation of the laws of quantum mechanics on a macroscopic scale. The conditions under which superfluidity becomes manifest have been extensively explored experimentally in both quantum liquids (liquid 4He being the canonical example) and ultracold atomic gases, including as a function of dimensionality. Of particular interest is the hitherto unresolved question of whether a solid can be superfluid. Here we report the identification of a new state of quantum matter with intertwined superfluid and density wave order in a system of two-dimensional bosons subject to a triangular lattice potential. Using a torsional oscillator we have measured the superfluid response of the second atomic layer of 4He adsorbed on the surface of graphite, over a wide temperature range down to 2 mK. Superfluidity is observed over a narrow range of film densities, emerging suddenly and subsequently collapsing towards a quantum critical point. The unusual temperature dependence of the superfluid density in the limit of zero temperature and the absence of a clear superfluid onset temperature are explained, self-consistently, by an ansatz for the excitation spectrum, reflecting density wave order, and a quasi-condensate wavefunction breaking both gauge and translational symmetry.

Uterine fibroids affect approximately 65% of women over age 45. They are a large source of morbidity in the United States and throughout the world. The predominant treatment is hysterectomy. [...]

In the ever evolving NHS change is the one consistent factor. For some change is exciting, for others it’s threatening. No community likes to ‘lose’ its hospital, but what if change could bring a better local service? Brian Cowan reflects on the development of ACADs as a complimentary alternative to the traditional hospital site: a service and buildings redesigned around the patients. Chris Levison reflects on the practical implications the change could have on chaplaincy including: multidisciplinary team-working, spiritual needs, and closer community contacts. These papers were presented at the Chaplaincy Conference at Crieff in May 2000.

Seventeenth-century English virtuoso attitudes to the visual arts have often been contrasted with a putative eighteenth-century culture of connoisseurship, most notably in a still influential 1942 article by Walter Houghton. This essay revisits Houghton's thesis and argues that English virtuoso culture did indeed allow for an incipient notion of artistic connoisseurship but that it did so in a manner different from the French model. The first section details a virtuoso aesthetic in which a modern approach to the cultural heritage of antiquity was central. The instructive ethical and historical attributes of an art work were deemed more important than attribution to a master artist, although one can discern an incipient notion of a virtuoso canon of great artists. The second section examines the social and institutional position of the English virtuosi and argues that the lack of a Royal Academy of Arts in the French manner made virtuoso attitudes to the arts unusually receptive to outside influences such as the Royal Society and other private clubs and academies. It concludes by considering the ways in which some eighteenth-century concepts of taste and connoisseurship defined themselves in contrast to an earlier and wider-ranging virtuosity even if they failed to fully supplant it.

Anthony Ashley Cooper, the third earl of Shaftesbury (1671–1713), would have recoiled at any implication that he was a libertine. His antipathy to libertinism is obvious, and examples are plentiful in his writings. His major work, the Characteristics of Men, Manners, Opinions, Times(1711), consistently uses the words “libertine” and “rake” as insults; in all of his writings sensual pleasures are disparaged as base and animalistic threats to human virtue. And despite the third earl's widespread reputation as a freethinker in matters religious, he always insisted that liberty of thought did not imply a freedom from moral restraint.Certainly Shaftesbury's early reputation was more that of a shy and unsociable recluse rather than that of a rakish mondain. In 1721, John Toland thought it necessary to defend his late friend from accusations of unsociability, not of licentiousness. He claimed that Shaftesbury's enemies “gave out that he was too bookish, because not given to play, nor assiduous at court; that he was no good companion, because not a rake nor a hard drinker, and that he was no man of the world, because not selfish nor open to bribes.” Toland also remarked how Shaftesbury frowned upon the “extravagant liberties” taken by “both sexes” even without having lived “to see masquerades, or the ancient Bacchanals revived, nor to hear of promiscuous clubs.” Indeed, Lord Ashley's own private papers reveal that he was quite uncomfortable in the polite world of England's social elite; he much preferred the pastoral tranquillity of his Dorset estate and the relaxed company of his most trusted friends.

The mechanical dissipation of a submonolayer helium film adsorbed on the surface of graphite has been studied as a function of coverage and temperature through the two dimensional melting transition. The measurements were made with a high Q torsional oscillator over the temperature range 1.5 to 5K on both4He and3He films. The largest dissipation was observed in the incommensurate solid phase and increased with decreasing temperature and increasing surface density. Plots of dissipation vs. temperature break away from a common curve at the “melting temperature” defined by the observed maxima in the film heat capacity. This may provide evidence for continuous melting of the two dimensional solid. It is believed that the dissipation arises not from interfacial friction between the adsorbate and substrate but rather from internal friction in the solid crystallites. The effect of surface morphology has been investigated by using Grafoil and UCAR ZYX as substrates.

Pulsed NMR measurements on helium-3 adsorbed on Mylar film have been made at a Larmor frequency of 5 MHz for fractional monolayer coverages between 0.3 and 1. Relaxation times were measured at temperatures between 1.2 and 4 K for different orientations of the substrate plane with respect to the static magnetic field. Our results are consistent with a “patchy solid” model where approximately 0.1 of a monolayer remains relatively immobile, providing the relaxation mechanism, while the rest of the adsorbate remains fluid. We have no evidence for an abrupt transition of this fluid to a solid phase.

Within the framework of a general theory of two-dimensional NMR we are able to elucidate certain anomalous features of spin relaxation in adsorbed and porous systems. We explain the linear dependence of relaxation time on applied magnetic field, and this is demonstrated to be related to the relative insensitivity ofT1to temperature. We also show thatT1remains field dependent on the “fast” side of theT1minimum.

The National Earthquake Hazards Reduction Reauthorization Act of November 16, 1990 required the NEHRP agencies to organize a program of postearthquake investigations that would take advantage of the opportunity to use worldwide damaging earthquakes as a scientific laboratory.

Abstract: The properties of two dimensional frustrated magnets have been studied in an investigation of the nuclear magnetism of two dimensional solid3He. The results of recent heat capacity and NMR measurements on3He films adsorbed on graphite are reported. The coverage dependence reveals both antiferromagnetic and ferromagnetic rgimes and their description in terms of Heisenberg series expansions is discussed. There is clear evidence of frustration by multiple spin exchange, with no magnetic phase transition. 2D3He currently provides the best model system for the study of S=1/2 quantum antiferromagnetism on a triangular lattice. There is evidence that the frustration can be tuned, and hence the ground state order.

The second layer of solid3He adsorbed on graphite exhibits a pronounced exchange anomaly which is peaked sharply at a surface density of 0.075Å-2. The much weaker exchange anomaly in the submonolayer solid film, first detected in heat capacity studies, has been investigated by measurements of the nuclear magnetic susceptibility to temperatures below 1mK and found to be ferromagnetic. We report the dependence of the effective exchange constant on surface density and propose a model in which both anomalies arise from similar two dimensional commensurate structures.

An excerpt from the article "Mr. Spectator and the Coffeehouse Public Sphere," by Brian Cowan is presented.

The heat capacity and the magnetization of the second solid layer of3He adsorbed on graphite have been measured to temperatures below 1mK. Prior to the formation of a fluid overlayer the temperature dependence of both sets of data is well described by high temperature series expansions for a 2D Heisenberg antiferromagnet on a triangular lattice. Differing exchange constants from the two quantities provide a measure of frustration due to multiple spin exchange. The subsequent evolution to ferromagnetic exchange suggests that this arises from variations in the coverage dependence of the frustration. After promotion it is found that an antiferromagnetic heat capacity coexists with a ferromagnetic susceptibility. At the ferromagnetic anomaly, the heat capacity is well described by series expansions for a 2D Heisenberg ferromagnet with effective exchange constant close to that determined from the magnetisation, indicating weak frustration.

Focuses on the program of the motorist writers and motoring enthusiasts all over the world to search for the Car of the Century. Background information on the program; Information on how the program will be implemented; Countries with the most number of nominations for the search.

Nuclear magnetic resonance has been used to study the registered phase of helium-3 adsorbed on grafoil. Spin-lattice and spin-spin relaxation times have been measured over a range of Larmor frequencies from 1 MHz to 10 MHz. There are two contributions to the relaxation: the internuclear dipolar interaction and the internal demagnetising field of the graphite. We are able to distinguish these effects. Dipole-dipole relaxation is well understood for two dimensional systems and the atomic motion has been analysed on this basis. At registry there is a reduction in the mobility of the adsorbate by approximately one order of magnitude. However, there still remains considerable temperature independent motion which we interpret as quantum exchange.

We present spin-spin relaxation time measurements for helium-3 adsorbed on grafoil in the solid phase. Spin-lattice relaxation measurements have already been analysed and the quantum exchange frequency estimated. Whereas it is only the internuclear dipolar interaction that mediates spin-lattice relaxation, for spin-spin relaxation both dipole dipole and the internal demagnetising fields of the graphite make a contribution. By analysing the frequency dependence of the relaxation time we have distinguished the dipole-dipole part: the frequency independent contribution. This has been analysed to give a measure of the exchange frequency in substantial agreement with that from T1measurements.