135 research outputs found

    Voltage dip immunity aspects of power-electronic equipment : recommendations from CIGRE/CIRED/UIE JWG C4.110

    Get PDF
    This paper presents some of the results from an international working group on voltage-dip immunity. The working group has made a number of recommendations to reduce the adverse impact of voltage dips. Specific recommendations to researchers and manufacturers of powerelectronic equipment are considering all voltage dip characteristics early in the design of equipment; characterize performance of equipment by means of voltage-dip immunity curves; and made equipment with different immunity available

    Anodic dissolution of metals in oxide-free cryolite melts

    Get PDF
    The anodic behavior of metals in molten cryolite-alumina melts has been investigated mostly for use as inert anodes for the Hall-HĂ©roult process. In the present work, gold, platinum, palladium, copper, tungsten, nickel, cobalt and iron metal electrodes were anodically polarized in an oxide-free cryolite melt (11%wt. excess AlF3 ; 5%wt. CaF2) at 1273 K. The aim of the experiments was to characterize the oxidation reactions of the metals occurring without the effect of oxygen-containing dissolved species. The anodic dissolution of each metal was demonstrated, and electrochemical reactions were assigned using reversible potential calculation. The relative stability of metals as well as the possibility of generating pure fluorine is discussed

    Influence of antiferromagnetic spin ordering on the far-infrared active optical phonon modes of alpha-MnSe

    Get PDF
    The effects of spin-phonon interaction and magnetic anisotropy on the temperature dependence of the infrared optical phonon modes in the antiferromagnetic alpha-MnSe are investigated by use of Green’s function formalism within 1/z perturbation framework. The renormalization effects are calculated explicitly as a function of temperature, phonon-phonon, and spin-phonon interaction constants. Temperature dependence of the renormalized LO phonon frequencies of the F1u infrared active and combinational phonon modes are calculated and compared with experimental data. We have shown that the inclusion of anisotropy is necessary in order to get a good quantitative agreement with the experiment

    Voltage-dip immunity: statistics and need for further work

    Get PDF
    Abstract. This paper presents the main results from CIGRE/CIRED/UIE working group JWG C4.110 and an overview of the need for further work identified by this working group. The paper goes into more details of the voltage-dip statistics collected by the working group and on methods to present the results from voltage-dip surveys

    Factors associated with Toxoplasma gondii infection in confined farrow-to-finish pig herds in western France: an exploratory study in 60 herds

    Get PDF
    Background: Infection by Toxoplasma gondii postnatally can occur after ingestion of contaminated meat or water (tissue cysts/oocysts). In Europe, percentage of meat borne infections is estimated between 30 and 63 %, out of which pork makes the most important source. The aim of this study was to (i) investigate the seroprevalence of T. gondii in intensive pig farms from western France; and (ii) identify the risk factors associated with seropositivity. Methods: Data were collected between November 2006 and February 2008 in 60 intensive farrow-to-finish farms, where sera were taken from 3595 fattening pigs, weaned and suckling piglets. Information about three classes of potential seropositivity risk factors were obtained through a questionnaire concerning: (i) breeding characteristics; (ii) farm management; and (iii) husbandry and hygiene. The modified agglutination test (MAT) was used for detection of specific anti T. gondii antibodies in pig sera, starting from 1/6 dilution. Results: The overall proportion of seropositive animals was 6.9 %, but the proportion of herds with at least one positive pig was 100 %. Multivariate logistic mixed model showed an increased seropositivity risk in weaned compared to suckling piglets, and a decreasing risk for mid-sized and large farms. The presence of a Danish entry facility, that clearly separates clean and dirty areas, had a protective effect on T. gondii seropositivity as well. Conclusions: The observed proportion of herds with at least one T. gondii seropositive animal provides further evidence that even in confined conditions of pig breeding, infection occurs, and is common. The highest risk for acquiring T. gondii is at the end of weaning period. Smaller confined pig farms demonstrate higher T. gondii seropositivity levels. This study also showed that Danish entry on farm buildings provides effective protection against T. gondii

    Calcium electroporation and electrochemotherapy for cancer treatment:Importance of cell membrane composition investigated by lipidomics, calorimetry and in vitro efficacy

    Get PDF
    Abstract Calcium electroporation is a novel anti-cancer treatment investigated in clinical trials. We explored cell sensitivity to calcium electroporation and electroporation with bleomycin, using viability assays at different time and temperature points, as well as heat calorimetry, lipidomics, and flow cytometry. Three cell lines: HT29 (colon cancer), MDA-MB231 (breast cancer), and HDF-n (normal fibroblasts) were investigated for; (a) cell survival dependent on time of addition of drug relative to electroporation (1.2 kV/cm, 8 pulses, 99 ”s, 1 Hz), at different temperatures (37 °C, 27 °C, 17 °C); (b) heat capacity profiles obtained by differential scanning calorimetry without added calcium; (c) lipid composition by mass spectrometry; (d) phosphatidylserine in the plasma membrane outer leaflet using flow cytometry. Temperature as well as time of drug administration affected treatment efficacy in HT29 and HDF-n cells, but not MDA-MB231 cells. Interestingly the HT29 cell line displayed a higher phase transition temperature (approximately 20 °C) versus 14 °C (HDF-n) and 15 °C (MDA-MB231). Furthermore the HT29 cell membranes had a higher ratio of ethers to esters, and a higher expression of phosphatidylserine in the outer leaflet. In conclusion, lipid composition and heat capacity of the membrane might influence permeabilisation of cells and thereby the effect of calcium electroporation and electrochemotherapy

    Sperm whale long-range echolocation sounds revealed by ANTARES, a deep-sea neutrino telescope

    Get PDF
    [EN] Despite dedicated research has been carried out to adequately map the distribution of the sperm whale in the Mediterranean Sea, unlike other regions of the world, the species population status is still presently uncertain. The analysis of two years of continuous acoustic data provided by the ANTARES neutrino telescope revealed the year-round presence of sperm whales in the Ligurian Sea, probably associated with the availability of cephalopods in the region. The presence of the Ligurian Sea sperm whales was demonstrated through the real-time analysis of audio data streamed from a cabled-to- shore deep-sea observatory that allowed the hourly tracking of their long-range echolocation behaviour on the Internet. Interestingly, the same acoustic analysis indicated that the occurrence of surface shipping noise would apparently not condition the foraging behaviour of the sperm whale in the area, since shipping noise was almost always present when sperm whales were acoustically detected. The continuous presence of the sperm whale in the region confirms the ecological value of the Ligurian sea and the importance of ANTARES to help monitoring its ecosystemsThe authors acknowledge the financial support of the funding agencies: Centre National de la Recherche Scientifique (CNRS), Commissariat a lenergie atomique et aux energies alternatives (CEA), la Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), IdEx program and UnivEarthS Labex program at Sorbonne Paris Cite (ANR-10-LABX-0023 and ANR-11-IDEX-0005-02), Region Ile-de-France (DIM-ACAV), Region Alsace (contrat CPER), Region Provence-Alpes-Cote d'Azur, Departement du Var and Ville de La Seyne-sur-Mer, France; Bundesministerium fur Bildung und Forschung (BMBF), Germany; Istituto Nazionale di Fisica Nucleare (INFN), Italy; Stichting voor Fundamenteel Onderzoek der Materie (FOM), Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; Council of the President of the Russian Federation for young scientists and leading scientific schools supporting grants, Russia; National Authority for Scientific Research (ANCS), Romania; Ministerio de Economia y Competitividad (MINECO), Prometeo and Grisolia programs of Generalitat Valenciana and MultiDark, Spain; Agence de l'Oriental and CNRST, Morocco. We also acknowledge the technical support of Ifremer, AIM and Foselev Marine for the sea operation and the CC-IN2P3 for the computing facilitiesAndre, M.; CaballĂ©, A.; Van Der Schaar, M.; Solsona, A.; HouĂ©gnigan, L.; Zaugg, S.; Sanchez, AM.... (2017). Sperm whale long-range echolocation sounds revealed by ANTARES, a deep-sea neutrino telescope. Scientific Reports. 7:1-12. https://doi.org/10.1038/srep45517S1127Aguilar, J. A. et al. ANTARES: the first undersea neutrino telescope. Nucl Inst and Met Phys Res A. 656, 11–38 (2011a).Aguilar, J. A. et al. AMADEUS - The Acoustic Neutrino Detection Test System of the ANTARES Deep-Sea Neutrino Telescope -. Nucl Inst and Met Phys Res A. 626–627, 128–143 (2011b).Ruhl, H. et al. Societal need for improved understanding of climate change, anthropogenic impacts, and geo-hazard warning drive development of ocean observatories in European Seas. Prog Oceanog. 91, 1–33 (2011).Tamburini, C. et al. Deep-sea bioluminescence blooms after dense water formation at the ocean surface. PLoS One. 8(7), e67523. doi: 10.1371/journal.pone.0067523 (2013).Van Haren, H. et al. Acoustic and optical variations during rapid downward motion episodes in the deep North Western Mediterranean. Deep Sea Res I. 58, 875–884 (2011).Van der Graaf, A. J. et al. European Marine Strategy Framework Directive - Good Environmental Status (MSFD GES): Report of the Technical Subgroup on Underwater noise and other forms of energy (2012).Hatch, L. T., Clark, C. W., Van Parijs, S. M., Frankel, A. S. & Ponirakis, D. W. Quantifying Loss of Acoustic Communication Space for Right Whales in and around a U.S. National Marine Sanctuary. Conserv Biol. 26, 983–994 (2012).AndrĂ©, M. et al. Low-frequency sounds induce acoustic trauma in cephalopods. Front. Ecol. Environ. 9, 489–493 (2011).SolĂ©, M. et al. Does exposure to noise from human activities compromise sensory information from cephalopod statocysts? Deep Sea Res. II. 95, 160–181 (2013).SolĂ©, M. et al. Ultrastructural damage of Loligo vulgaris and Illex coindetii statocysts after low frequency sound exposure. PLoS One 8(10), e78825. doi: 10.1371/journal.pone.0078825 (2013).AndrĂ©, M. et al. Listening to the Deep: Live monitoring of ocean noise and cetacean acoustic signals. Mar Pollut Bull. 63, 18–26 (2011).Whitehead, H. Sperm whales: social evolution in the ocean(The University of Chicago Press, Chicaho, 2003).Mohl, B., Wahlberg, M., Madsen, P. T., Heerfordt, A. & Lund, A. The monopulsed nature of sperm whale clicks. J Acous Soc Am. 114, 1143–1154 (2003).AndrĂ©, M., Johansson, T., Delory, E. & van der Schaar, M. Foraging on squid: the sperm whale mid-range sonar. Jour Mar Biol Assoc. 87, 59–67 (2007).Madsen, P., Wahlberg, M. & MĂžhl, B. Male sperm whale (Physeter macrocephalus) acoustics in a high-latitude habitat: implications for echolocation and communication. Behav Ecol Sociobiol. 53, 31, doi: 10.1007/s00265-002-0548-1 (2002).Gannier, A., Drouot, V. & Goold, J. C. Distribution and relative abundance of sperm whales in the Mediterranean Sea . Mar Ecol Prog Ser. 243, 281–293 (2000).Drouot, V., Gannier, A. & Gould, J. C. Summer social distribution of sperm whales in the Mediterranean Sea. J Mar Biol Ass. 84, 675–680 (2004).Pavan, G. et al. G. Short Term and Long Term Bioacoustic Monitoring of the Marine Environment. Results from NEMO ONDE Experiment and Way Ahead in Computational bioacoustics for assessing biodiversity . Proceedings of the International Expert meeting on IT-based detection of bioacoustical patterns(ed. Frommolt, K. H., Rolf Bardeli, R. & Clausen, M. ) 7–14 (Federal Agency for Nature Conservation, Bonn, 2008).Frantzis, A. et al. Sperm whale presence off South-West Crete, Eastern Mediterranean Sea in Proc. 13th Ann. Conf. ECS. 214–217 (Eur Res Cet, Valencia, 1999).Notarbartolo-Di-Sciara, G. Sperm whales, Physeter macrocephalus, in the Mediterranean Sea: a summary of status, threats, and conservation recommendations. Aquatic Conserv. Mar. Freshw. Ecosyst. 24, 4–10. doi: 10.1002/aqc.2409 (2014).Pace, D. S., Mussi, B., Gordon, J. C. D. & WĂŒrtz, M. Ecology, Behaviour and Conservation of Sperm Whale in the Mediterranean Sea in Aquatic Conserv . Mar. Freshw. Ecosyst. 24 (ed. Wiley, J. ) 1–118 (Wiley Online library, 2014).Rendell, L. E. & Frantzis, A. Mediterranean sperm whales, Physeter macrocephalus: the precarious state of a lost tribe In Medit. Mar. Mam. Ecol. Cons. 75 (ed. Notarbartolo di Sciara, G., PodestĂ , M. P. & Curry, B. E. ) 37–74, doi: 10.1016/bs.amb.2016.08.001 (Advances in Marine Biology, Academic Press/Elsevier, 2016).Di Natale, A. & Notarbartolo di Sciara, G. A review of the passive fishing nets and trap fisheries in the Mediterranean Sea and of the cetacean bycatch In Gillnets and cetaceans(ed. Perrin, W. F., Donovan, G. P. & Barlow, J. ) 189–202 (Rep Int Whal Comm, 1994).Jaquet, N., Whitehead, H. & Lewis, M. Relationship between sperm whale distribution and primary productivity over large spatial scale in the Pacific ocean. Eur Res Cet. 9, 188–192 (1995).Millot, C. Circulation in the Western Mediterranean Sea. Oceanol Acta. 10, 143–150 (1987).Morel, A. & AndrĂ©, J. M. Pigment distribution and primary production in the Western Mediterranean as derived from coastal zone color scanner observations. J Geophy Res. 96, 2685–12698 (1991).CrĂ©pon, M., Wald, L. & Monget, J. M. Low-frequency waves in the Ligurian Sea during December 1977. J Geophys Res. 87, 595–600 (1982).Prieur, L. & Sathyendranath, S. An optical classification of coastal and oceanic waters based on the specific spectral absorption curves of phytoplankton pigments, dissolved organic matter, and other particulate materials. Limnol Oceanogr. 26, 671–89 (1981).Kawakami, T. A review of sperm whale food. Sci Rep Whales Res Inst. 32, 199–218 (1980).Roper, C. F. E. & Young, R. E. Vertical distribution of pelagic cephalopods. Smithson Contrib Zool. 209, 1–51 (1975).Matsushita, T. Daily rhythmic activity of the sperm whales in the Antarctic. Bull Jpn Soc Sci Fish. 20, 770–73 (1955).Zaugg, S. et al. Real-time acoustic classification of sperm whale clicks and shipping impulses from deep-sea observatories. Appl Acoust. 71(11), 1011–1019 (2010).Nelder, J. & Wedderburn, R. Generalized linear models. J R Stat Soc. 135, 370–384 (1972)
    • 

    corecore