Phase structure and phase transitions in a three dimensional SU(2) superconductor

We study the three dimensional SU(2)-symmetric noncompact CP1 model, with two charged matter fields coupled minimally to a noncompact Abelian gauge-field. The phase diagram and the nature of the phase transitions in this model have attracted much interest after it was proposed to describe an unusual continuous transition associated with deconfinement of spinons. Previously, it has been demonstrated for various two-component gauge theories that weakly first-order transitions may appear as continuous ones of a new universality class in simulations of relatively large, but finite systems. We have performed Monte-Carlo calculations on substantially larger systems sizes than those in previous works. We find that in some area of the phase diagram where at finite sizes one gets signatures consistent with a single first-order transition, in fact there is a sequence of two phase transitions with an O(3) paired phase sandwiched in between. We report (i) a new estimate for the location of a bicritical point and (ii) the first resolution of bimodal distributions in energy histograms at relatively low coupling strengths. We perform a flowgram analysis of the direct transition line with rescaling of the linear system size in order to obtain a data collapse. The data collapses up to coupling constants where we find bimodal distributions in energy histograms.Comment: 16 pages, 11 figures. Submitted to Physical Review

Petroleum geochemistry of the deepened Lopra-1/1A re-entry well, Faroe Islands

The Lopra-1/1A re-entry well was drilled as a stratigraphic test with no immediate exploration objectives. Hence, petroleum geochemical studies were of limited extent, and restricted to non-destructive analyses. The presence of natural petroleum hydrocarbons could not be confirmed with certainty, but hydrocarbons extracted from the hydrochloric acid solute of a calcite vug present in RSWC #1 (3543 m), may represent indigenous petroleum since hydrocarbon-bearing fluid inclusions have been reported from the same sample. These hydrocarbons show some similarities to petroleum generated from the Upper Jurassic – Lower Cretaceous Kimmeridge Clay type source rocks present in surrounding areas. Except for this sample, the results generally show the presence of a variety of contaminants of different origins such as ‘naturally greasy fingers’ (squalene and cholesterol), cosmetics such as chap stick or hand lotion (e.g. esters such as butyl-stearate, stearyl-palmitate, vitamin A), plasticisers (phthalates), diesel oil and ‘pipe dope’

Six years of petroleum geological activities in North-East Greenland (2008–2013): projects and a view of the future

The deadline for applications to the first licence round for petroleum exploration offshore North-East Greenland was 15 December 2012. The round was restricted, allowing only members of the KANUMAS consortium to be operators (BP, Chevron, Exxon, JOGMEG, Shell and Statoil). Nunaoil is also part of KANUMAS, but it is a carried, non-operator partner. An ordinary licensing round followed shortly after with a deadline on 15 October 2013

Age of oils in West Greenland: was there a Mesozoic seaway between Greenland and Canada?

For many years the existence of an oil-prone source rock off West Greenland was challenged by industry. But since 1992 when active oil seeps were found onshore West Greenland on the Nuussuaq peninsula (Fig. 1; Christiansen et al. 1996; Bojesen-Koefoed et al. 1999), the question has changed focus to the age, distribution and potential of the source rock. Five different oils – each with their own characteristics – have been reported by the Geological Survey of Denmark and Greenland (GEUS). One of these, a typical marine shalederived oil with a possible regional distribution, is known as the Itilli oil. Geochemical analysis suggests that it may have been generated from Cenomanian–Turonian age marine shales, equivalent to prolific source rocks known from Ellesmere Island, Nunavut, Canada. Three of the other oils were generated from deltaic source rocks of Albian, Campanian and Paleocene ages, while one is of unknown origin (Bojesen-Koefoed et al. 1999). The presence of a regional marine source rock is important to petroleum exploration; GEUS has therefore investigated the possible existence of Mesozoic, in particular Cenomanian–Turonian, petroleum source rocks in West Greenland offshore areas. Since sediments older than the Santonian are not known from any of the six wells drilled offshore West Greenland (Fig. 1), assessment of oil-prone source rocks in older sedimentary successions must rely on circumstantial evidence offered by oil chemistry data and analogy studies. Petroleum in quantities amenable to chemical analysis has so far not been recovered from offshore. However, oilbearing fluid inclusions are known from the Ikermiut-1 well (unpublished data 2001, Phillips Petroleum and GEUS), a gas-kick was recorded during drilling of the Kangâmiut-1 well (Bate 1997), and seismic data indicate hydrocarbons in many areas (cross-cutting reflectors, bright spots, smearing of seismic). Petroleum exploration offshore West Greenland suffered for many years under the misconception that oceanic crust covered vast areas, rendering the region unattractive. However, the presence of thick sedimentary successions and rotated fault blocks in Cretaceous basins have been demonstrated to be present in areas previously believed to be underlain by Cretaceous–Tertiary oceanic crust (cf. Chalmers & Pulvertaft 2001). New high-quality seismic data, acquired by the seismic company TGS-NOPEC over recent years, combined with gravimetric data, have further demonstrated the presence of deep basins containing thick sedimentary successions in other areas (e.g. Christiansen et al. 2002). Despite the progress made over the past few years, the geological evolution of the Davis Strait region in general remains poorly understood, but new data on oil chemistry may shed some light on the history of this region

Sygdomme og velfærd

Siden anden verdenskrig er der sket store ændringer i fjerkræproduktionen. Indførslen af nye produktionssystemer, robuste og højtydende dyr, forbedret management og indførslen af biosecurity har medført en stor produktionsfremgang med lav mortalitet. I de senere år har forbrugerønsker medført at udvikling af udendørs produktionssystemer, hvor de klassiske fjerkræsygdomme nu er på fremmarch med en forhøjet mortalitet til følge. Forfatterne diskuterer, om de udendørs produktionssystemer reelt har betydet en forbedret velfærd for hønerne