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1.
Sci Total Environ ; 946: 174314, 2024 Jun 27.
Article in English | MEDLINE | ID: mdl-38944305

ABSTRACT

Shipping activity can be a substantial source of pollution and impact on the environment, including air, water and ecosystems, as well as adverse health and climatic effects. Due to the distribution of maritime transport activity routes in the EU, a large portion of the population is exposed to shipping pollution throughout Europe. The ongoing European project EMERGE aims to investigate and quantify these impacts over Europe, and in more detail, in specific case studies regions. The Aveiro lagoon region in Portugal is one of these case studies. This region is a Natura 2000 area, and also includes a medium-sized port. Both air quality and water modelling tools were applied to assess the impact of the emissions and discharges from shipping (to air and water) in the region in 2018. Additionally, ecotoxicological impacts were determined by bioassays to evaluate the impact of scrubber-water discharges on the most sensitive stages of marine invertebrates, and on the post-exposure feeding inhibition of crustacean and bivalve species. The results show that there was a substantial increase in atmospheric pollutant concentrations due to emissions attributed to shipping, which was most relevant for NOx and SO2 (up to a 30 % shipping contribution). There was no significant degradation of the water quality, mainly as the ships operating in this area did not have scrubber equipment. The ecotoxicological tests were performed with three samples of scrubber water, including one artificial sample and two samples collected on-board ships. If scrubber water would have been discharged in this area, the results indicated that the majority of the tested species would be exposed to lowest observed effect concentration (LOEC) for the different scrubber-water samples, as well as to substantial concentrations of metals, PAHs, and alkylated PAHs.

2.
Sci Rep ; 6: 37571, 2016 11 24.
Article in English | MEDLINE | ID: mdl-27883029

ABSTRACT

Kinetic helicity is one of the invariants of the Euler equations that is associated with the topology of vortex lines within the fluid. In superfluids, the vorticity is concentrated along vortex filaments. In this setting, helicity would be expected to acquire its simplest form. However, the lack of a core structure for vortex filaments appears to result in a helicity that does not retain its key attribute as a quadratic invariant. By defining a spanwise vector to the vortex through the use of a Seifert framing, we are able to introduce twist and henceforth recover the key properties of helicity. We present several examples for calculating internal twist to illustrate why the centreline helicity alone will lead to ambiguous results if a twist contribution is not introduced. Our choice of the spanwise vector can be expressed in terms of the tangential component of velocity along the filament. Since the tangential velocity does not alter the configuration of the vortex at later times, we are able to recover a similar equation for the internal twist angle to that of classical vortex tubes. Our results allow us to explain how a quasi-classical limit of helicity emerges from helicity considerations for individual superfluid vortex filaments.

3.
Nat Commun ; 4: 1614, 2013.
Article in English | MEDLINE | ID: mdl-23511478

ABSTRACT

A superfluid in the absence of a viscous normal component should be the best realization of an ideal inviscid Euler fluid. As expressed by d'Alembert's famous paradox, an ideal fluid does not drag on bodies past which it flows, or in other words it does not exchange momentum with them. In addition, the flow of an ideal fluid does not dissipate kinetic energy. Here we study experimentally whether these properties apply to the flow of superfluid (3)He-B in a rotating cylinder at low temperatures. It is found that ideal behaviour is broken by quantum turbulence, which leads to substantial energy dissipation, as was also observed earlier. Remarkably, the angular momentum exchange between the superfluid and its container approaches nearly ideal behaviour, as the drag almost disappears in the zero-temperature limit. Here the mismatch between energy and angular momentum transfer results in a new physical situation, with severe implications on the flow dynamics.

4.
Phys Rev Lett ; 107(13): 135302, 2011 Sep 23.
Article in English | MEDLINE | ID: mdl-22026868

ABSTRACT

Steady-state turbulent motion is created in superfluid (3)He-B at low temperatures in the form of a turbulent vortex front, which moves axially along a rotating cylindrical container of (3)He-B and replaces vortex-free flow with vortex lines at constant density. We present the first measurements on the thermal signal from dissipation as a function of time, recorded at 0.2T(c) during the front motion, which is monitored using NMR techniques. Both the measurements and the numerical calculations of the vortex dynamics show that at low temperatures the density of the propagating vortices falls well below the equilibrium value, i.e., the superfluid rotates at a smaller angular velocity than the container. This is the first evidence for the decoupling of the superfluid from the container reference frame in the zero-temperature limit.

5.
J Small Anim Pract ; 52(8): 402-10, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21797871

ABSTRACT

OBJECTIVES: To describe bilateral lens instability in 10 related domestic shorthair cats over three generations. METHODS: Complete ophthalmic examinations were performed. Lentectomies were carried out. Sections of affected lenses focused on the equatorial area were examined by transmission electron microscopy. The potential involvement of several candidate genes (ADAMTS17, ADAMTSL4, ADAMTS10 and FBN1) known to be associated with lens luxation in other species was investigated. RESULTS: The group of animals included 10 related cats, nine of them being affected by lens instability over three generations. Transmission electron microscopy showed the presence of zonular material at the lens equator. Signs of lens instability were not associated with other ocular disease. Analysis of the pedigree suggests a dominantly inherited condition. A mutation in ADAMTS17 was excluded, but a possible association between the condition and a microsatellite flanking FBN1 indicates this gene should be considered a strong candidate responsible for primary lens luxation in this pedigree. CLINICAL SIGNIFICANCE: These observations suggest an inherent zonular defect unrelated to extraneous factors. The family relationship is compatible with a possible genetic basis, and the pedigree suggests that the condition could be dominant. Data also suggest the mutation in the FBN1 gene could be responsible for primary lens luxation in this pedigree of cats.


Subject(s)
ADAM Proteins/genetics , Cat Diseases/genetics , Lens Subluxation/veterinary , Lens, Crystalline/pathology , Pedigree , Animals , Base Sequence , Cat Diseases/pathology , Cat Diseases/surgery , Cats , Exons , Female , Lens Subluxation/genetics , Lens Subluxation/pathology , Lens Subluxation/surgery , Lens, Crystalline/ultrastructure , Male , Microscopy, Electron, Transmission/veterinary , Mutation , Prospective Studies , Sequence Alignment
6.
Phys Rev Lett ; 105(12): 125301, 2010 Sep 17.
Article in English | MEDLINE | ID: mdl-20867649

ABSTRACT

A central question in the dynamics of vortex lines in superfluids is dissipation on approaching the zero temperature limit T→0. From both NMR measurements and vortex filament calculations, we find that vortex flow remains laminar up to large Reynolds numbers Re{α}∼10(3) in a cylinder filled with 3He-B. This is different from viscous fluids and superfluid 4He, where the corresponding responses are turbulent. In 3He-B, laminar vortex flow is possible in the bulk volume even in the presence of sizable perturbations from axial symmetry to below 0.2Tc. The laminar flow displays no excess dissipation beyond mutual friction, which vanishes in the T→0 limit, in contrast with turbulent vortex motion where dissipation has been earlier measured to approach a large T-independent value at T≲0.2Tc.

7.
Phys Rev Lett ; 99(26): 265301, 2007 Dec 31.
Article in English | MEDLINE | ID: mdl-18233586

ABSTRACT

We present experimental, numerical, and theoretical studies of a vortex front propagating into a region of vortex-free flow of rotating superfluid 3He-B. We show that the nature of the front changes from laminar through quasiclassical turbulent to quantum turbulent with decreasing temperature. Our experiment provides the first direct measurement of the dissipation rate in turbulent vortex dynamics of 3He-B and demonstrates that the dissipation becomes mutual-friction independent with decreasing temperature, and it is strongly suppressed when the Kelvin-wave cascade on vortex lines is predicted to be involved in the turbulent energy transfer to smaller length scales.

8.
Phys Rev E Stat Nonlin Soft Matter Phys ; 74(4 Pt 2): 046303, 2006 Oct.
Article in English | MEDLINE | ID: mdl-17155169

ABSTRACT

We consider finite-amplitude Kelvin waves on an inviscid vortex assuming that the vortex core has infinitesimal thickness. By numerically solving the governing Biot-Savart equation of motion, we study how the frequency of the Kelvin waves and the velocity of the perturbed ring depend on the Kelvin wave amplitude. In particular, we show that, if the amplitude of the Kelvin waves is sufficiently large, the perturbed vortex ring moves backwards.

9.
Phys Rev Lett ; 96(21): 215302, 2006 Jun 02.
Article in English | MEDLINE | ID: mdl-16803244

ABSTRACT

We study a twisted vortex bundle where quantized vortices form helices circling around the axis of the bundle in a "force-free" configuration. Such a state is created by injecting vortices into a rotating vortex-free superfluid. Using continuum theory we determine the structure and the relaxation of the twisted state. This is confirmed by numerical calculations. We also present experimental evidence of the twisted vortex state in superfluid 3He-B.

10.
Phys Rev Lett ; 96(8): 085301, 2006 Mar 03.
Article in English | MEDLINE | ID: mdl-16606194

ABSTRACT

A surface-mediated process is identified in 3He-B which generates vortices at a roughly constant rate. It precedes a faster form of turbulence where intervortex interactions dominate. This precursor becomes observable when vortex loops are introduced in low-velocity rotating flow at sufficiently low mutual friction dissipation at temperatures below 0.5Tc. Our measurements indicate that the formation of new loops is associated with a single vortex interacting in the applied flow with the sample boundary. Numerical calculations show that the single-vortex instability arises when a helical Kelvin wave expands from a reconnection kink at the wall and then intersects again with the wall.

11.
J Environ Radioact ; 83(3): 371-81, 2005.
Article in English | MEDLINE | ID: mdl-15951071

ABSTRACT

A compendium of agricultural countermeasures and rural waste disposal options has been compiled as part of the EC STRATEGY (Sustainable Restoration and Long-Term Management of Contaminated Rural, Urban and Industrial Ecosystems) project. The compendium was discussed by the FARMING (Food and Agriculture Restoration Management Involving Networked Groups) network of stakeholders during meetings of national panels in the UK, Finland, Belgium, Greece and France in 2002. Their preliminary feedback has been summarised in terms of whether an option is generally acceptable, unacceptable or only acceptable under specific circumstances. A considerable divergence of opinion between national panels was apparent for many of the options considered. This could be attributed to differences in geomorphology, climate, land management, infrastructure, consumer confidence, sociopolitical context and culture. Where consensus was reached between stakeholders it was generally for those countermeasures that provide public reassurance, sustain farming practices and minimise environmental impact. Furthermore, whilst there was general agreement that contaminated food should not enter the food chain, many of the options proposed for its subsequent management were not generally acceptable to stakeholders.


Subject(s)
Decision Support Systems, Management/organization & administration , Decontamination/methods , Disaster Planning , Ecosystem , Food Contamination, Radioactive/prevention & control , Agriculture , Animals , Cities , Decision Support Systems, Management/trends , Europe , Food Supply , Humans , Industry , Information Services , Policy Making , Refuse Disposal/methods , Rural Population
12.
J Environ Radioact ; 83(3): 263-74, 2005.
Article in English | MEDLINE | ID: mdl-15951072

ABSTRACT

The EC FARMING network (Food and Agriculture Restoration Management Involving Networked Groups) was set up to bring together the many and diverse stakeholders who would be involved in intervention following wide scale radioactive contamination of the food chain, so that acceptable strategies can be developed for maintaining agricultural production and safe food supply. The network comprises stakeholder panels in the UK, Finland, Belgium, France and Greece that have met regularly since 2001 to debate, discuss and exchange opinion on the acceptability, constraints and impact of various countermeasure options and strategies. The objectives of this paper are to consolidate the main achievements of the FARMING project over the period 2000-2004, to highlight the various difficulties that were encountered and to discuss the challenges for engaging stakeholders in off-site emergency management and long-term rehabilitation in the future.


Subject(s)
Decision Support Systems, Management/organization & administration , Environmental Health , Food Contamination, Radioactive/prevention & control , Safety Management/organization & administration , Agriculture , Animals , Consumer Product Safety , Databases, Factual , Decision Support Systems, Management/trends , Decontamination/methods , Emergencies , European Union , Humans , Neural Networks, Computer , Radiation Protection/methods , Safety Management/methods , Safety Management/trends
13.
Radiat Prot Dosimetry ; 109(1-2): 127-32, 2004.
Article in English | MEDLINE | ID: mdl-15238670

ABSTRACT

A widely used method in the planning of protective actions is to establish a stakeholder network to generate a comprehensive set of generic protective actions. The aim is to increase competence and build links for communication and coordination. The approach of this work was to systematically evaluate protective action strategies in the case of a nuclear accident. This was done in a way that the concerns and issues of all key players could be transparently and equally included in the decision taken. An approach called Facilitated Decision Analysis Workshop has been developed and tested. The work builds on case studies in which it was assumed that a hypothetical accident had led to a release of considerable amounts of radionuclides and, therefore, various types of countermeasures had to be considered. Six workshops were organised in the Nordic countries where the key players were represented, i.e. authorities, expert organisations, industry and agricultural producers.


Subject(s)
Decision Support Systems, Management/organization & administration , Disaster Planning/methods , Disaster Planning/organization & administration , Radiation Protection/methods , Radioactive Hazard Release , Risk Assessment/methods , Safety Management/organization & administration , Emergencies , European Union , Information Dissemination/methods , Interinstitutional Relations , Leadership , Power Plants , Risk Factors , Safety Management/methods , Teaching/methods
14.
Phys Rev Lett ; 90(22): 225301, 2003 Jun 06.
Article in English | MEDLINE | ID: mdl-12857317

ABSTRACT

We study a two-phase sample of superfluid 3He where vorticity exists in one phase (3He-A) but cannot penetrate across the interfacial boundary to a second coherent phase (3He-B). We calculate the bending of the vorticity into a surface vortex sheet on the interface and solve the internal structure of this new type of vortex sheet. The compression of the vorticity from three to two dimensions enforces a structure which is made up of 1 / 2-quantum units, independently of the structure of the source vorticity in the bulk. These results are consistent with our NMR measurements.

15.
Brain ; 125(Pt 6): 1265-74, 2002 Jun.
Article in English | MEDLINE | ID: mdl-12023315

ABSTRACT

Under normal circumstances, information from a number of sources is combined to compute a unitary percept of the body. However, after pathology these influences may be perceived simultaneously, resulting in multiple dissociated conscious representations. In a recent paper, we described subject E.P., a right-handed female stroke patient with a right frontomesial lesion who sporadically experiences a supernumerary 'ghost' left arm that occupies the previous position of the real left arm after a delay of 60-90 s. We used a delayed response paradigm with functional MRI to examine the haemodynamic correlates of E.P.'s illusion. Comparison of periods of time during scanning when the ghost arm was present against when it was not revealed a single cluster (9 voxels, t = 5.11, P < 0.012 corrected for multiple comparisons) located on the right medial wall in the supplementary motor area ('SMA proper'). Our results suggest that areas traditionally classified as part of the motor system can influence the conscious perception of the body. We propose that, as a consequence of her injury, E.P. is aware of the position of the phantom limb in this 'action space' while also continuing to be aware of the true position of her real limb on the basis of afferent somatosensory information.


Subject(s)
Arm/physiology , Magnetic Resonance Imaging/methods , Phantom Limb/diagnosis , Phantom Limb/psychology , Adult , Female , Humans , Motor Cortex/physiology , Phantom Limb/physiopathology
16.
Neurosci Lett ; 240(3): 131-4, 1998 Jan 16.
Article in English | MEDLINE | ID: mdl-9502221

ABSTRACT

We describe patient E.P. who occasionally perceives a 'ghost' hand which copies the previous positions of the left hand with a 0.5-1 min time lag, but follows the movement patterns of the right hand. The symptoms started after an operation of a ruptured aneurysm, followed by an infarction of the right frontal lobe; E.P. also has a previously lesioned corpus callosum. Neuromagnetic recordings revealed that activity of the left secondary somatosensory cortex was strongly suppressed during the ghost arm percept, thereby providing an objective correlate for E.P.'s sensations. We conclude that simultaneous mental contents about body scheme may be based on neural information extracted at considerably different times, resulting in fragmentation of bodily awareness.


Subject(s)
Awareness/physiology , Body Image , Hand/innervation , Hand/physiopathology , Adult , Cerebral Infarction/physiopathology , Cerebral Infarction/psychology , Female , Functional Laterality , Humans , Intracranial Aneurysm/physiopathology , Intracranial Aneurysm/psychology , Proprioception/physiology , Syndrome
17.
Arch Clin Neuropsychol ; 3(1): 9-32, 1988.
Article in English | MEDLINE | ID: mdl-14589561

ABSTRACT

The relationship between simultaneous and successive processing and their assumed underlying neuro-anatomical structures was examined. According to the model of Das, Kirby, and Jarman (1975, 1979) simultaneous processing, occurs mainly in the posterior parts of the brain (parieto-occipital areas) and successive processing in anterior regions of the brain (fronto-temporal areas). The theory of lateralized hemispheric specialization suggests differences in processing due to right-left hemispheric differences. A battery of measures was factor-analyzed and simultaneous and successive factors identified in 106 brain-damaged adults and a control group. The brain damaged group was divided into four subgroups, left and right anterior and left and right posterior groups. The two-way ANOVA revealed no interactions (laterality x anterior/posterior), but instead two main effects for laterality on simultaneous verbal (p<.01) and successive (p<.05) processing and one weak (p<. 10) main effect for anterior/posterior divisions of simultaneous nonverbal processing. It was concluded that the results partially supported both assumed neuropsychological models of processing.

18.
In. International Atomic Energy Agency (IAEA). Emergency planning and preparedness for nuclear facilities. Vienna, International Atomic Energy Agency (IAEA), Apr. 1986. p.13-26, ilus, tab. (Proceedings Series).
Monography in En | Desastres -Disasters- | ID: des-13731

ABSTRACT

The Finnish concept of off-site nuclear emergency response has reamined vitually constant since 1976, when the first public authoritie's emergency plan was prepared. The first principle is that of remote siting, meaning restrictions on land use within about 5 km from the power plant. In off-sitte emergency planning two zone are applied: (1) for an area within a radius of about 20 km (zone I), a detailed off-site plan is required, including rapid alerting of the population and evacuations if necessary; (2) for the surrounding area, within a radius of about 100 km (zone II), the special requirements imposed by a potential nuclear accident have to be taken into account in the general emergency preparedness planning. The emphasis on contemplated protective measures for the public has shifted somewhat over the years. Earlier, evacuation was seen as the principal course of action and sheltering was considered mainly as precaution while awaiting a decision on evacuation. However, a commissioned study on the significance of evacuation and local sheltering pointed out that the level of sheltering afforded by large stone buildings and cellars is sufficient to reduce significantly the doses received. Consequently, the evacuation capacity could be to those areas where the buildings provide the poorest protection, i.e. summer cottages and wooden houses with no basements. Subsequently the Finnish Centre for Radiation and Nuclear Safety undertook a survey of the types of houses and building materials in the environs of the nuclear power plants. Rough estimates of the average protection factors of small houses, small houses cellars and the ground floor of typical apartment houses were made. (AU)


Subject(s)
Nuclear Power Plants , Radioactive Hazard Release , Nuclear Reactors , Disaster Planning , 50207 , Finland , Nuclear Energy , National Health Strategies
19.
Phys Med Biol ; 30(9): 921-8, 1985 Sep.
Article in English | MEDLINE | ID: mdl-3901049

ABSTRACT

The total nitrogen concentrations in dried serum from 54 pregnant women and 17 newborn babies were determined by a new application of the 14N(p,p' gamma)14N reaction resonance at 3.9 MeV. The samples were bombarded in a He atmosphere by 4.1 MeV protons from a tandem Van de Graaff accelerator. The mean dry-weight nitrogen concentration in serum sampled during early pregnancy (6-12 weeks; 13.9 g per 100 g +/- 5.4%) was significantly higher than that in serum sampled during late pregnancy (38-42 weeks: 13.0 g per 100 g +/- 3.9%, p less than 0.001) and than that in serum taken from the umbilical cord (13.3 g per 100 g +/- 4.6%, p less than 0.01). The nitrogen levels measured using this rapid nuclear technique, applied for the first time to human serum analysis, agree well with parallel Kjeldahl analyses.


Subject(s)
Nitrogen Radioisotopes , Nitrogen/blood , Pregnancy , Female , Fetal Blood/analysis , Humans , Infant, Newborn , Pregnancy Trimester, First , Pregnancy Trimester, Third , Radioisotope Dilution Technique/instrumentation
20.
Brain Lang ; 26(1): 28-48, 1985 Sep.
Article in English | MEDLINE | ID: mdl-4052746

ABSTRACT

The phonemic errors of three Finnish Broca's aphasics were analyzed according to various phonological features, frequency of segments, syllable, word, and stress positions, as well as for the phonotactic structure of the uncanonical products. It was found, e.g., that the distance between the syntagmatic error and its source could not be satisfactorily counted by phonemes, since the syllable had to be taken into account also in pathological Finnish. As regards the paradigmatic dimension of the errors, the number of incorrect features is even here in reverse relation to the frequency of the erroneous phonemes. Moreover, it was found that pure quantity errors and vowel harmony deviations are infrequent in the speech of Finnish Broca's aphasics.


Subject(s)
Aphasia, Broca/psychology , Aphasia/psychology , Adult , Female , Humans , Language , Linguistics , Male , Phonetics
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