777 research outputs found

    Seasonal variation of cesium 134 and cesium 137 in semidomestic reindeer in Norway after the Chernobyl accident

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    The Chernobyl accident had a great impact on the semidomestic reindeer husbandry in central Norway. Seasonal differences in habitat and diet resulted in large variations in observed radiocesium concentrations in reindeer after the Chernobyl accident. In three areas with high values of cesium-134 and cesium-137 in lichens, the main feed for reindeer in winter, reindeer were sampled every second month to monitor the seasonal variation and the decrease rate of the radioactivity. The results are based on measurements of cesium-134 and cesium-137 content in meat and blood and by whole-body monitoring of live animals. In 1987 the increase of radiocesium content in reindeer in Vågå were 4x from August to January. The mean reductions in radiocesium content from the winter 1986/87 to the winter 1987/88 were 32%, 50% and 43% in the areas of Vågå, Østre-Namdal and Lom respectively

    Induction skull melt spinning of reactive metal alloys

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    An apparatus for melting and rapid solidification casting of metal alloys has a crucible for molding a metal charge. The crucible has side walls, a top and a bottom having an orifice therein. Collectively, the side walls, top and bottom define an interior of the crucible. A portion of the dimensions of the side walls of the side walls and bottom is divided by longitudinal slits into at least two segments. A nozzle is disposed partially within the crucible and extends through the orifice. The nozzle has a first end in communication with the interior of tune crucible. A second end of the nozzle has a nozzle orifice therein for defining a stream of molten metal alloy. A cooling mechanism cools the top, side walls and bottom of the crucible. The apparatus has mechanisms for inducing alternating electrical currents within the metal charge and within the nozzle, and for establishing and maintaining pressure within the interior of the crucible. A positioning mechanism positions the crucible and nozzle means relative to a quenching mechanisms that includes a rapidly moving chill substrate. The crucible, nozzle and quenching mechanism are housed within an enclosure that provides there within a controlled atmosphere having positive or negative pressure

    Heat treatment of rapidly quenched Fe-6.5 wt % Si ribbon

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    A rapidly quenched Fe-Si Alloy containing 6 to 7 wt % is heat treated to promote and control an order-disorder reaction, thereby improving its ac core loss and exciting power at induction levels about B=1.2 T. The alloy has a substantially texture, a grain size of about 1 to 2 mm, a R2 domain size of 100 to 850 nm, a DO3 domain size of about 5 to 25 nm, an ac core loss of about 1.2 to 1.6 W/kg and an exciting power of about 15 to 46 VA/kg, the core loss and exciting power being measured at an induction level of B=1.4 T and a frequency of f=60 Hz

    A content analysis of SOLO-levels in different computer programming courses in higher education

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    The dynamic development of technology and the labour market changes the requirements of today's education and the dissemination of knowledge. Information technologies (IT) and digital competencies (DC) are no longer knowledge just for the few that study Computer Science (CS), but it has become a part of common knowledge for every citizen. By using content analysis, this article will examine the developed content of two different ā€œintroduction to programmingā€ courses from two different higher education institutions. Both institutions introduce programming to students outside of CS. This study aims to describe how the developed content of these courses aims to reach the different levels of learning outcomes, by using the framework Structure of the Observed Learning Outcome taxonomy (SOLO-taxonomy) developed by Biggs and Collis (1982). The results of the study show that introduction to programming courses in different professions have a different understanding of what programming is, or what it consists of. The courses about ā€œintroduction to programmingā€ are planned and executed within its fields, which gives the students a different perspective on what programming is, compared to the average IT or CS course. This means that the term ā€œgood programming skillsā€ is different for a teacher, engineer, or computer scientist because of their unique goals and motivations for why they learned to program in the first place

    Barrierer mot kollisjoner mellom fartĆøy og innretninger. Identifisering, vurderinger og mulige forbedringstiltak

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    -Denne rapporten omhandler Statoil Marine Operasjoner sin logistikk-kjede og er en evaluering av eksisterende barrierer mot kollisjon mellom forsyningsfartĆøy og innretning. Rapporten er et resultat av en studie gjennomfĆørt pĆ„ oppdrag fra Statoil Marine Operasjoner. HovedmĆ„lsettingen for studien var tredelt. Vi Ćønsket Ć„ kartlegge hvordan kollisjoner mellom fartĆøy og innretning kan oppstĆ„, hvilke barrierer som eksisterer og hvor gode disse barrierene er. Totalt 47 personer fra logistikk-kjeden er blitt intervjuet. I tillegg er det blitt gjennomfĆørt en fareidentifikasjon (HAZID) med en hĆ„ndplukket ekspertgruppe som representerte de sentrale leddene i logistikk-kjeden. Dette materialet dannet bakgrunnen for en oversikt og godhetsvurdering av 32 sentrale primƦr- og sekundƦrbarrierer som er identifisert, da knyttet til fĆølgende aktiviteter: fartĆøyanskaffelser, baseaktiviteter, seiling, entring av sikkerhetssonen, lossing/lasting, og avgang fra innretning. Hovedinntrykket er at det er mange, godt fungerende barrierer som reduserer sannsynligheten for sammenstĆøt mellom fartĆøy og innretning. Likevel peker denne rapporten pĆ„ noen omrĆ„der der barrierene kan styrkes ytterligere. I prioritert rekkefĆølge vi vil spesielt fremheve fire slike omrĆ„der: 1.FartĆøymannskapet bĆør tilbys mer trening pĆ„ manuell manĆøvrering av fartĆøy for Ć„ styrke hĆ„ndteringen av eventuelt bortfall av Dynamisk posisjonering (DP), framdriftsproblemer og nĆødsituasjoner under losse- og lasteoperasjoner. 2.Vi viser til mangler ved DP-referansesystemer (Radius, Fanbeam) ved en rekke innretninger som svekker redundansen. Her er vĆ„r anbefaling at redundansen styrkes ved Ć„ sĆørge for at referansesystemer blir montert pĆ„ samtlige installasjoner. 3.Det bĆør legges til rette for en stĆørre involvering av personell fra innretningene i utarbeidelsen av laste- og seilingsplaner. Dette vil redusere risikoen for sammenstĆøt mellom fartĆøy og innretning ved at liggetid ved innretninger reduseres. 4.En bedre logistikkplanlegging knyttet til rigger kan ogsĆ„ redusere liggetiden

    A Transiting Planet of a Sun-like Star

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    A planet transits an 11th magnitude, G1V star in the constellation Corona Borealis. We designate the planet XO-1b, and the star, XO-1, also known as GSC 02041-01657. XO-1 lacks a trigonometric distance; we estimate it to be 200+-20 pc. Of the ten stars currently known to host extrasolar transiting planets, the star XO-1 is the most similar to the Sun in its physical characteristics: its radius is 1.0+-0.08 R_Sun, its mass is 1.0+-0.03 M_Sun, V sini < 3 km/s, and its metallicity [Fe/H] is 0.015+-0.04. The orbital period of the planet XO-1b is 3.941534+-0.000027 days, one of the longer ones known. The planetary mass is 0.90+-0.07 M_Jupiter, which is marginally larger than that of other transiting planets with periods between 3 and 4 days. Both the planetary radius and the inclination are functions of the spectroscopically determined stellar radius. If the stellar radius is 1.0+-0.08 R_Sun, then the planetary radius is 1.30+-0.11 R_Jupiter and the inclination of the orbit is 87.7+-1.2 degrees. We have demonstrated a productive international collaboration between professional and amateur astronomers that was important to distinguishing this planet from many other similar candidates.Comment: 31 pages, 9 figures, accepted for part 1 of Ap

    Changes in Alcoholic Beverage Choice and Risky Drinking among Adolescents in Europe 1999ā€“2019

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    This paper explores trends in beverage preference in adolescents, identifies related regional differences, and examines cluster differences in key drinking measures. Data were obtained from the European School Survey Project on Alcohol and Other Drugs (ESPAD), covering 24 European countries between 1999 and 2019. Trends in the distribution of alcoholic beverages on the participantsā€™ most recent drinking occasion were analysed by sex and country using fractional multinomial logit regression. Clusters of countries based on trends and predicted beverage proportions were compared regarding the prevalence of drinkers, mean alcohol volume and prevalence of heavy drinking. Four distinct clusters each among girls and boys emerged. Among girls, there was not one type of beverage that was preferred across clusters, but the proportion of cider/alcopops strongly increased over time in most clusters. Among boys, the proportion of beer decreased, but was dominant across time in all clusters. Only northern European countries formed a geographically defined region with the highest prevalence of heavy drinking and average alcohol volume in both genders. Adolescent beverage preferences are associated with mean alcohol volume and heavy drinking at a country-level. Future approaches to drinking cultures need to take subpopulations such as adolescents into account

    Deep brain stimulation can suppress pathological synchronisation in parkinsonian patients

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    Background Although deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a highly effective therapeutic intervention in severe Parkinson's disease, its mechanism of action remains unclear. One possibility is that DBS suppresses local pathologically synchronised oscillatory activity.Methods To explore this, the authors recorded from DBS electrodes implanted in the STN of 16 patients with Parkinson's disease during simultaneous stimulation (pulse width 60 mu s; frequency 130 Hz) of the same target using a specially designed amplifier. The authors analysed data from 25 sides.Results The authors found that DBS progressively suppressed peaks in local field potential activity at frequencies between 11 and 30 Hz as voltage was increased beyond a stimulation threshold of 1.5 V. Median peak power had fallen to 54% of baseline values by a stimulation intensity of 3.0 V.Conclusion The findings suggest that DBS can suppress pathological 11-30 Hz activity in the vicinity of stimulation in patients with Parkinson's disease. This suppression occurs at stimulation voltages that are clinically effective
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