WorldWideScience

Sample records for barn reactor

  1. Dismantling of Biological Agricultural Reactor Netherlands (BARN)

    International Nuclear Information System (INIS)

    The Biological Agricultural Reactor (BARN) was built in 1962 by government order through the Institute for Atomic Science in Agriculture (ITAL) in the Netherlands. The idea to build this nuclear reactor especially for biological research purposes was grown out of the first international conference about peaceful application of atomic energy hold in 1955. The construction composed of a basin reactor with light water as moderator and cooling medium. Up to 90% enriched Uranium was used as fuel. The maximal power was 100 kW. The reactor was used for research in the field of plant reproduction and other biological research. Mainly because of disappointing scientific results in 1978, 15 years after the start, the decision was made to terminate the reactor process following by dismantling. Alternative techniques proved to give comparative results at lower costs. In the decision making process political considerations played an important role. Prior to dismantling the reactor the 26 fuel elements were removed. Beside the uranium-235 each element contains about 1.3 TBq of fission and activation products. In 1982 the elements were shipped tot the Savannah River Plant in United States. An extensive analyze was carried out to map out the activation products on basis of neutron flux data, radiation history and composition of the materials. Results of this study was used to predict the dose rate of the different activated items and consequently to reduce risks of handling the items. For several reasons (e.g. control of building, knowledge of the plant) in 1996 a project has been initiated to remove all the active materials form the building and to recover the place to the original state, i.e. forest. High radioactive items with large dimensions were transferred to the so-called 'hot cells' of the ECN and were cut into small pieces. Finally all the activated material was brought to the COVRA for end storage. Parts of the basin construction were highly activated and were removed

  2. Det postmoderne barn

    DEFF Research Database (Denmark)

    Hansen, Ole Henrik

    2010-01-01

    Den nye psykologi fokuserer på dynamik og intersubjektivitet, mens den gamle var optaget af faser og udviklingstrin. Den postmoderne forståelse af det lille barn opfatter ikke faserne som aflåste, historiske sandheder, men som levende narrativer. Og så får det nye børnesyn indflydelse på Frode og...

  3. Greenhouse gas emissions from barn animals

    International Nuclear Information System (INIS)

    Ninety six per cent of the carbon dioxide produced by barn animals is generated through the act of breathing, with the remainder generated through their droppings. The author examined various sources of carbon dioxide emissions associated with barn animals, including the animals themselves, their droppings and heating systems for barns. A similar review was conducted for emissions of methane and nitrous oxide. The author proposed ways to reduce the production of carbon dioxide and methane by barn animals. 8 refs., 1 tab

  4. Barn i den fortettede byen

    OpenAIRE

    Cederkvist, Kjersti Prytz

    2010-01-01

    Problemstillingen i denne masteroppgaven er en liten del av det store problemkomplekset omkring bokvalitet og fortetting. Jeg har ønsket å undersøke sammenhengen mellom fortetting og oppvekstvilkår for barn i Oslo, og tatt for meg uterom i tilknytning til nye boligprosjekter. Utgangspunktet for oppgaven er en antagelse (hypotese) om at barn ofte blir den tapende part ved de prioriteringer som blir foretatt når nye boligprosjekter realiseres i en by under fortetting. Plan- og bygningsetaten(PB...

  5. Til forsvar for barns spontane lek

    Directory of Open Access Journals (Sweden)

    Einar Sundsdal

    2015-04-01

    Full Text Available Barndommens far, Jean-Jacques Rousseau (1712-1778, og senere, barnehagens grunnlegger, Friedrich Frøbel (1782-1852, var begge opptatt av barndom og barns mulighet til å tape tid. Dette ble betegnet som negativ pedagogikk og innebar blant annet at barn skulle fordrive tiden med det som passet for barn: lek. Barna skulle få holde på for seg selv, voksne skulle ikke bedrive undervisning, men la barn oppdage verden selv. Disse tankene har vært sentrale for vår moderne forestilling om barndom, og de har vært premissgivende for Barnekonvensjonen som slår fast at alle barn har rett til å leke. Også i dag har leken en sentral posisjon når vi snakker om barndom, men nå knyttes den til en forestilling om å vinne tid. Barn blir nå skjøvet fremover slik at de ikke skal kaste bort tiden - tape tiden - men utnytte den mest mulig effektivt med tanke på et fremtidig resultat. Denne logikken har bidratt til at FN i 2013 gikk ut og advarte om at barns rett til lek er truet. I denne artikkelen vil vi forfølge FNs forsvar for barns spontane lek. Vi vil gjøre dette blant annet ved å vise at lekens egenverdi står stadig sterkere innen en rekke forskningstradisjoner.

  6. Rodenticides in British barn owls.

    Science.gov (United States)

    Newton, I; Wyllie, I; Freestone, P

    1990-01-01

    Out of 145 Barn Owls found dead through accidents (66%), starvation (32%), shooting (2%) and poisoning (difenacoum or brodifacoum, in their livers. Difenacoum was in the range 0.005-0.106 microg g(-1) fresh weight, and brodifacoum was in the range 0.019-0.515 microg g(-1). Minimum levels of detection were about 0.005 microg g(-1) for both chemicals. Mice fed for 1 day on food containing difenacoum and brodifacoum died after 2-11 days. Within these mice residues were present at greater concentration in the liver than in the rest of the carcass. The mean mass of residue in a whole 35g mouse was estimated at 10.17 microg (range 4.73-20.65 microg) for difenacoum and 15.36 microg (range 8.07-26.55) for brodifacoum. Such poisoned mice were fed to Barn Owls for successive periods of 1, 3 and 6 days. All six owls fed on difenacoum-dosed mice survived all three treatments, in which up to an estimated 101.7 microg of difenacoum was consumed, and the coagulation times of their blood returned to near normal in less than 5-23 days. Four of the six owls fed on brodifacoum-dosed mice died 6-17 days after the 1-day treatment, but the survivors also survived the 3-day and 6-day treatments. Those that died had each eaten 3 mice, with a combined weight of about 105g and a total brodifacoum content of about 46.07 microg, which was equivalent to a dose of 0.150-0.182 mg kg(-1) of owl body weight. After death these owls had 0.63-1.25 micro g(-1) of brodifacoum in their livers. Blood from the survivors would not coagulate at 9 days post-treatment, but did so at 16 days in one bird and between 38 and 78 days in the other. It is concluded that: (1) Barn Owls in Britain are now widely exposed to second-generation rodenticides; (2) not all owls exposed to these chemicals are likely to receive a lethal dose; (3) brodifacoum is more toxic to owls than difenacoum; and (4) while there is yet no evidence that rodenticides have had any appreciable effect on Barn Owl populations in Britain, further

  7. Ernæring til premature barn

    OpenAIRE

    Von Køppen, Karin Helene

    2013-01-01

    Studien konkluderer med at ernæring er et område som er av stor betydning for premature barn. Metoder som NIDCAP har en positiv innvirkning på ernæringsstatusen til premature barn fordi overgangen fra sondeernæring til oral ernæring går lettere. Behovet for norske anbefalinger er nødvendig for å kunne tilby premature barn den optimale omsorgen som gjør at de har det beste utgangspunktet for å overleve utenfor mors liv.

  8. Kvinnors reflektioner kring beslutet att skaffa barn

    OpenAIRE

    Sandell, Annie

    2007-01-01

    Att bli mamma har alltid setts som ett självklart val för majoriteten av kvinnor. Det tillhör normen att en dag föda barn. Syftet med denna studie var att studera kvinnors reflektioner kring deras beslut att skaffa barn. Resultatet baserades på fem halvstrukturerade intervjuer som tolkades med induktiv tematisk analysmetod. Ett bekvämlighetsurval användes och de informanter som deltog var kvinnor som hade ett seriöst förhållande med en man. De hade ännu inte några barn men hade bestämt sig fö...

  9. Respiratory symptoms and functions in barn workers

    OpenAIRE

    Ege Gulec Balbay; Emine Banu Cakiroglu; Peri Arbak; Öner Balbay; Fatma Avcıoğlu; Abdullah Belada

    2014-01-01

    Introduction and aim. The presented study was undertaken to investigate the respiratory health problems in family barns with one or more cows and at least one family member working in the barn. Methods. 150 workers (128 female, 22 male) from 4 villages of Yığılca district near the city of Düzce in north-west Turkey were enrolled in this study between October – December 2011. An Occupational and Environmental Chest Diseases questionnaire developed by the American Thoracic Society, pulmonary...

  10. SETTINGS IN THE NOVELS OF JULIAN BARNES

    OpenAIRE

    Gajanan N. Katkar

    2013-01-01

    Julian Barnes was born in Leicester, England's East midland, on January 19,1946 in the family of a teacher. His father, Albert taught French at st. Clement Danesfrom 1937 onwards till his retirement in 1971. His mother, Keye, also taught French. Hiselder brother, Jonathan is now a Professor of Philosophy in Geneva. He married PatKavanagh in 1979, and now lives with her in North London.

  11. Julian Barnes: A Significant Contmporary Novelist

    OpenAIRE

    Gajanan N. Katkar

    2012-01-01

    Julian Barnes was born in Leicester, England's East midland, on January 19, 1946 in the family of a teacher. His father, Albert taught French at st. Clement Danes from 1937 onwards till his retirement in 1971. His mother, Keye, also taught French. His elder brother, Jonathan is now a Professor of Philosophy in Geneva.He married Pat Kavanagh in 1979, and now lives with her in North London.

  12. Det sunde, overvægtige barn

    DEFF Research Database (Denmark)

    From, Ditte-Marie

    kommunale sundhedskurser. Men hvad sker der, når en biomedicinsk sundhedsopfattelse møder det overvægtige barn i en hverdagslivssammenhæng? Hvor meget handler sundhed f.eks. om at besidde tilstrækkelige mængder af viden om mad og motion? Og hvad er mulighederne for at være en god borger, selvom man er et...

  13. Barnkonventionen och ansvarsfördelningen mellan barn och vuxna

    DEFF Research Database (Denmark)

    Stolz, Pauline

    2011-01-01

    Barn- och utbildningspolitik är, precis som andra former av politik, redskap som politiker använder sig av för att uppnå social förändring. Barn används därmed av politiker och andra vuxna i utbildningspolitiska sammanhang för att förändra samhället i en viss riktning. Barn kan i politiska diskus...

  14. A Second Look at Douglas Barnes's "From Communication to Curriculum"

    Science.gov (United States)

    Yarker, Patrick

    2016-01-01

    This article revisits Douglas Barnes's book-length exploration of the implications for teachers of a constructivist epistemology, notably in relation to the importance of small-group talk in classrooms. Empirically based consideration of small-group exploratory pupil-pupil talk enabled Barnes to reveal the learning strategies such a context…

  15. A survey of Italian compost dairy barns

    Directory of Open Access Journals (Sweden)

    Lorenzo Leso

    2013-12-01

    Full Text Available Compost-bedded pack barns (CBPB, generally known as compost dairy barns, are alternative housing systems for dairy cows. In these barns, the whole surface of the resting area is covered with a deepbedded pack that is frequently stirred in order to incorporate fresh manure into the pack and to enhance the evaporation of water. Experiences with CBPB for dairy cows are reported in literature from the US, Israel, the Netherlands and Austria. Potential advantages of these housing systems regard animal welfare and manure management. Since 2006, this housing system has been widely applied in Italy. However, there is still little scientific knowledge available about Italian CBPB. This study aims to describe the housing system, assess producers’ satisfaction and measure performance of dairy cows housed in CBPB. Ten commercial dairy farms in northern Italy were involved in the study. All pens in each farm were surveyed to determine the total available surface area, bedded area and pack depth. A questionnaire was submitted to each farm manager in order to investigate management practices, labour requirement, amount of bedding materials used and producers’ satisfaction. The temperature of the bedded pack was measured in summer and in winter. Data from the Italian Dairy Association were collected for each herd over a period of one year (from September 2011 to September 2012. In the barns involved in the study, the average total available area was 10.9 m2/cow and the average pack area was 6.7 m2/cow. The bedded pack was aerated 1.4 times per day.The most commonly used bedding material in these farms was dry sawdust. The consumption of bedding materials was 8.1 m3/cow per year. A tendency towards inverse correlation was found between the space per cow and the amount of bedding needed per cow (R2=0.395; P=0.051. Operations related to pack management required 4.1 hours of labour per cow per year. A direct relationship was found between the bedded area space

  16. Midwest cousins of Barnes-Wall lattices

    OpenAIRE

    Griess Jr., Robert L.

    2009-01-01

    Given a rational lattice and suitable set of linear transformations, we construct a cousin lattice. Sufficient conditions are given for integrality, evenness and unimodularity. When the input is a Barnes-Wall lattice, we get multi-parameter series of cousins. There is a subseries consisting of unimodular lattices which have ranks $2^{d-1}\\pm 2^{d-k-1}$, for odd integers $d\\ge 3$ and integers $k=1,2, ..., \\frac {d-1}2$. Their minimum norms are moderately high: $2^{\\lfloor \\frac d2 \\rfloor -1}$.

  17. Visual search in barn owls: from feature to conjunction search

    OpenAIRE

    Orlowski, Julius

    2015-01-01

    Visual search is the process of searching for something interesting in a cluttered environment. It is well studied in humans, but not in non-primate species. This study provides a comprehensive overview of visual search in barn owls using a novel methodology: the OwlCam. The OwlCam is a tiny, lightweight camera that can be mounted onto the head of barn owls to record first person videos from these birds. Due to the very limited eye movements of barn owls this provides an easy method of gaze t...

  18. 22 Matt Barnes 再出发

    Institute of Scientific and Technical Information of China (English)

    Husky

    2008-01-01

    太阳队·前锋·201厘米·28岁上季成绩·6.7分·42.3%投篮·4.4篮板如果你是我们的忠实读者,就会发现巴恩斯(Matt Barnes)在过去13个月内已经第三度登上这个单元了。究竟,这位生涯单季平均得分从没超过10分的球员,有何值得我们一再报导的地方呢?

  19. Marknadsföring till barn : Etik och ansvar

    OpenAIRE

    Haire, Miranda

    2013-01-01

    Detta examensarbete handlar om marknadsföring till barn, samt etiken och ansvaret kring ämnet. Ansvaret ligger mestadels hos marknadsförarna och föräldrarna. Marknadsföring till barn bedöms strängare av juridiska bestämmelser än vanlig marknadsföring, eftersom att barn är mera mottagliga och inte har samma erfarenhet som vuxna. Syftet med detta examensarbete är att få fram allmänt om marknadsföring till barn, etiska frågeställningar, samhällsansvaret samt ansvaret hos marknadsförare, föräldra...

  20. Carol A. Barnes: Award for Distinguished Scientific Contributions.

    Science.gov (United States)

    2014-11-01

    The APA Awards for Distinguished Scientific Contributions are presented to persons who, in the opinion of the Committee on Scientific Awards, have made distinguished theoretical or empirical contributions to basic research in psychology. One of the 2014 award winners is Carol A. Barnes, who received this award for her "groundbreaking work on the neurobiological mechanisms underlying memory changes in normal aging." Barnes' award citation, biography, and a selected bibliography are presented here. PMID:25486138

  1. A Dominance Hierarchy of Auditory Spatial Cues in Barn Owls

    OpenAIRE

    Witten, Ilana B.; Phyllis F Knudsen; Knudsen, Eric I.

    2010-01-01

    BACKGROUND: Barn owls integrate spatial information across frequency channels to localize sounds in space. METHODOLOGY/PRINCIPAL FINDINGS: We presented barn owls with synchronous sounds that contained different bands of frequencies (3-5 kHz and 7-9 kHz) from different locations in space. When the owls were confronted with the conflicting localization cues from two synchronous sounds of equal level, their orienting responses were dominated by one of the sounds: they oriented toward the locatio...

  2. Optimal models of sound localization by barn owls

    OpenAIRE

    Fischer, Brian J

    2009-01-01

    Sound localization by barn owls is commonly modeled as a matching procedure where localization cues derived from auditory inputs are compared to stored templates. While the matching models can explain properties of neural responses, no model explains how the owl resolves spatial ambiguity in the localization cues to produce accurate localization for sources near the center of gaze. Here, I examine two models for the barn owl’s sound localization behavior. First, I consider a maximum likeli...

  3. Hva kan barnehagen bidra med til barn som har opplevd samlivsbrudd?

    OpenAIRE

    Størksen, Ingunn

    2008-01-01

    Hvert år opplever mange norske barn samlivsbrudd. Internasjonale og norske studier viser at barn som har opplevd samlivsbrudd er i større risiko for ulike psykososiale problemer enn andre barn. Tidligere norske studier og tiltak omkring barn og samlivsbrudd har i hovedsak vært rettet mot barn og ungdom i skolen. På bakgrunn av forskning fra andre land vil jeg i denne artikkelen presentere mulige konsekvenser blant yngre barn som har opplevd samlivsbrudd. Videre vil jeg gå igjennom noen mulige...

  4. Barn swallows nesting near radioactive leaching ponds in southeastern Idaho

    International Nuclear Information System (INIS)

    Seasonally occurring populations of barn swallows nest near the Test Reactor Area (TRA) radioactive leaching ponds on the Idaho National Engineering Laboratory (INEL) Site. These birds utilize leaching pond arthropods and are therefore capable of accumulating radioactive materials and exporting them from the INEL Site during migration. The breeding biology is discussed for these swallows and a control group located 100 km away. Total nestling mortality for the controls and a 1977 TRA population was found to be statistically identical. Over 20 fission and activation products have been detected in immature and adult TRA birds. Mean concentrations of detectable radionuclides were used to calculate internal dose rates, and results showed that Na-24 contributed about 72% of the total average of 21.9 mrad/d for adult birds. Concentration factors were also calculated for predominant radionuclides in swallows relative to filtered pond water. Data from LiF dosimeters in swallow nests constructed with contaminated mud indicated average dose rates were 84 mrad/d for eggs and 220 mrad/d for nestlings. Growth curves were constructed for the immature TRA birds and controls. The first clutch of TRA swallows was found to have a significantly lower mean growth rate constant than the first clutch of controls. The statistical difference in growth rate between the control and TRA first clutch populations may have resulted from differences in climate, nesting site habitat, or available food sources, and cannot be solely attributed to radiation exposure as a causative factor. Growth rate parameters for TRA birds were within the range of values reported in the literature

  5. Otoacoustic interrelationships of the barn owl

    Science.gov (United States)

    Bergevin, Christopher; Manley, Geoffrey A.; Köppl, Christine

    2015-12-01

    Significant debate still exists about the biophysical mechanisms at work in otoacoustic emission (OAE) generation and how such may differ between mammals and non-mammals given gross morphological differences (e.g., existence of basilar membrane traveling waves, degree of tectorial membrane coupling). To further elucidate general principles at work, we examined the barn owl for interrelationships between spontaneous emissions (SOAEs) and those evoked using a single tone (SFOAEs). First, most ears exhibited SOAEs as a stable periodic `rippling' whose peak-to-peak spacing was relatively constant (˜0.4 kHz). Some ears showed substantially larger narrowband peaks, although their statistical distributions were highly noisy. Second, significant interactions between a low-level tone and SOAE activity were observed via an interference pattern as the tone frequency was swept. Using a suppression paradigm to extract SFOAEs as the residual, the magnitude exhibited a stable pattern of peaks and valleys unique to each ear. Third, SFOAE phase exhibited significant accumulation as frequency was swept, with a phase-gradient delay of approximately 2 ms that was constant across frequency. The amount of SFOAE phase accumulation between adjacent SOAE peaks tended to cluster about an integral number of cycles, as previously observed for humans. Taken together, our data suggest that the principles underlying how active hair cells work together (e.g., entrainment, phase coherence) are shared between widely different inner ear morphologies, leading to the generation of OAEs with similar properties.

  6. Adaptation potential of naturally ventilated barns to high temperature extremes: The OptiBarn project

    Science.gov (United States)

    Menz, Christoph

    2016-04-01

    Climate change interferes with various aspects of the socio-economic system. One important aspect is its influence on animal husbandry, especially dairy faming. Dairy cows are usually kept in naturally ventilated barns (NVBs) which are particular vulnerable to extreme events due to their low adaptation capabilities. An effective adaptation to high outdoor temperatures for example, is only possible under certain wind and humidity conditions. High temperature extremes are expected to increase in number and strength under climate change. To assess the impact of this change on NVBs and dairy cows also the changes in wind and humidity needs to be considered. Hence we need to consider the multivariate structure of future temperature extremes. The OptiBarn project aims to develop sustainable adaptation strategies for dairy housings under climate change for Europe, by considering the multivariate structure of high temperature extremes. In a first step we identify various multivariate high temperature extremes for three core regions in Europe. With respect to dairy cows in NVBs we will focus on the wind and humidity field during high temperature events. In a second step we will use the CORDEX-EUR-11 ensemble to evaluate the capability of the RCMs to model such events and assess their future change potential. By transferring the outdoor conditions to indoor climate and animal wellbeing the results of this assessment can be used to develop technical, architectural and animal specific adaptation strategies for high temperature extremes.

  7. Greenhouse gas emissions from naturally ventilated freestall dairy barns

    Science.gov (United States)

    Joo, H. S.; Ndegwa, P. M.; Heber, A. J.; Ni, J.-Q.; Bogan, B. W.; Ramirez-Dorronsoro, J. C.; Cortus, E.

    2015-02-01

    Greenhouse gas (GHG) emissions from two naturally-ventilated dairy freestall barns measured for a total of 21 d, one week each in May, July, and September 2009, are presented in this article. The holding capacity of Barn 1 (B1) was 400 Holstein cows, while that for Barn 2 (B2) was 850 cows. Air samples were taken from inlets and outlets of the barns via a custom made multiplexer gas sampling system for measurement of gas concentrations using a photoacoustic infrared multigas analyzer. Barn ventilation rates were based on air velocity measured with arrays of 3-D ultrasonic anemometers at inlets and outlets. Gas concentrations (10 min means) in the barns ranged from: 443-789 ppm for CO2, 0.0-39.4 ppm for CH4, and 0.25-0.39 ppm for N2O; with mean concentrations ranging from 6 to 20%, 0 to 4%, and 26 to 180% above the average background concentrations for CO2, N2O, and CH4, respectively. The correlations between CO2 and CH4 enhanced concentrations were relatively stronger (R of 0.67-0.74) than between CO2 and N2O enhanced concentrations (R of 0.10-0.20). Environmental conditions did not significantly (p = 0.46) impact the enhanced concentrations of N2O in the barns. All three parameters (T, RH, and v) had significant (p CO2 enhanced concentrations; while only T (p CO2 and CH4 correlated negatively with all three parameters. The influence of the temperature-humidity index (THI) on CO2 enhanced concentrations was higher than that of v; while the effect v had on CH4 enhanced concentrations was slightly higher than that of the temperature-humidity index. The average emissions, based on hourly means, ranged from 5.3 to 10.7 kg d-1 AU-1 for CO2; 0.3 to 2.5 g d-1 AU-1 for N2O; and between 67 and 252 g d-1 AU-1 for CH4. Nitrous oxide emissions from the smaller barn, B1 (0.4-2.5 g d-1 AU-1), were significantly higher than from the larger barn, B2 (0.3-0.5 g d-1 AU-1) most probably because 50% of B1 was open (no stalls) loose dirt floor.

  8. MBsums. A Mathematica package for the representation of Mellin-Barnes integrals by multiple sums

    Energy Technology Data Exchange (ETDEWEB)

    Ochman, Michal; Riemann, Tord

    2015-11-15

    Feynman integrals may be represented by the Mathematica package AMBRE and MB as multiple Mellin-Barnes integrals. With the Mathematica package MBsums we transform these Mellin-Barnes integrals into multiple sums.

  9. MBsums - a Mathematica package for the representation of Mellin-Barnes integrals by multiple sums

    CERN Document Server

    Ochman, Michal

    2015-01-01

    Feynman integrals may be represented by the Mathematica packages AMBRE and MB as multiple Mellin-Barnes integrals. With the Mathematica package MBsums these Mellin-Barnes integrals are transformed into multiple sums.

  10. REDESIGN OF COMMONLY USED TOBACCO CURING BARNS IN ZIMBABWE FOR INCREASED ENERGY EFFICIENCY

    Directory of Open Access Journals (Sweden)

    SPECIAL MUSONI

    2013-03-01

    Full Text Available In Zimbabwe two types of barns are commonly used for tobacco curing, namely the traditional and Rocket barns. The traditional barn and the Rocket Barn loose 98.5% and 55.6% of the energy supplied respectively. The latter is 43.6% more thermally efficient than the traditional barn. There is, however, potential of increasing the energy efficiency of both barns. In this study, a design that incorporates structural changes to reduce heat loss as well as recovery of heat was developed. The design is a combination of commercially available components, and allows for ventilation heat re-use and increased heat transfer from furnace ducts to the drying chamber. The structure was found to be 54.7% more thermally efficient than the Rocket barn and 74.2% more efficient than the traditional barn. The new design needs to be field-tested so that it can be adopted by tobacco farmers.

  11. Lung responses to secondary endotoxin challenge in rats exposed to pig barn air

    OpenAIRE

    Townsend Hugh GG; Aulakh Gurpreet K; Keet Taryn; Charavaryamath Chandrashekhar; Singh Baljit

    2008-01-01

    Abstract Background Swine barn air contains endotoxin and many other noxious agents. Single or multiple exposures to pig barn air induces lung inflammation and loss of lung function. However, we do not know the effect of exposure to pig barn air on inflammatory response in the lungs following a secondary infection. Therefore, we tested a hypothesis that single or multiple exposures to barn air will result in exaggerated lung inflammation in response to a secondary insult with Escherichia coli...

  12. Economic evaluation of biological rodent control using barn owls Tyto alba in alfalfa

    OpenAIRE

    Motro, Y.

    2011-01-01

    Rodents are common pests in various agricultural cultivations. Utilization of barn owls for rodent pest control has long been used. In Israel, the indirect effect of barn owl predation pressure on alfalfa crop yield has been examined. Using radio-telemetry, barn owls were tracked to form a density-distance function, which was later used to estimate predation pressure on whole fields. This function was utilized on all barn owls nesting in the vicinity to assess accumulated predation pressure o...

  13. Design methodology for the robotic milking barn : modelling, simulation, validation and optimization

    NARCIS (Netherlands)

    Halachmi, I.

    1999-01-01

    The traditional barn design is a milking parlour oriented. To integrate a milking robot the barn should be redesigned according to the robotic milking concept. The entire system (barn design, feeding and cow-traffic routines, management practices) should encourage 'voluntary milking', i.e., it shoul

  14. Pragmatiske ferdigheter hos barn med cochleaimplantat : - belyst ved et kasusstudie

    OpenAIRE

    2008-01-01

    Pragmatiske ferdigheter hos barn med cochleaimplantat - belyst ved et kasusstudie. Bakgrunn: Cochleaimplantat (CI) er et høreapparat som gir sterkt hørselshemmede muligheten til å oppfatte lyd. Elektroder implanteres i sneglehuset (cochlea) og stimulerer hørselsnerven direkte (MED-EL 2006, Waltzman 2005). Forskning rundt barn med CI og deres språkutvikling har hovedsakelig vært konsentrert rundt de lingvistiske sidene ved språket (Thoutenhoofd m. fl. 2005). Like viktig vil det være å se p...

  15. Reactors

    International Nuclear Information System (INIS)

    Purpose: To provide a spray cooling structure wherein the steam phase in a bwr reactor vessel can sufficiently be cooled and the upper cap and flanges in the vessel can be cooled rapidly which kept from direct contaction with cold water. Constitution: An apertured shielding is provided in parallel spaced apart from the inner wall surface at the upper portion of a reactor vessel equipped with a spray nozzle, and the lower end of the shielding and the inner wall of the vessel are closed to each other so as to store the cooling water. Upon spray cooling, cooling water jetting out from the nozzle cools the vapor phase in the vessel and then hits against the shielding. Then the cooling water mostly falls as it is, while partially enters through the apertures to the back of the shielding plate, abuts against stoppers and falls down. The stoppers are formed in an inverted L shape so that the spray water may not in direct contaction with the inner wall of the vessel. (Horiuchi, T.)

  16. John Dewey's Socially Instrumental Practice at the Barnes Foundation and the Role of "Transferred Values" in Aesthetic Experience

    Science.gov (United States)

    Johnson, Margaret Hess

    2012-01-01

    When Albert Barnes established an art education program at the Barnes Foundation in 1924, he asked John Dewey to become the first president and director of education. Barnes and Dewey enjoyed a sustained and fruitful relationship with regard to aesthetic experience and scientific theory as applied to education. Barnes and Dewey shared a serious…

  17. Barn owl productivity responses to fluctuating vole populations

    Czech Academy of Sciences Publication Activity Database

    Pavluvčík, P.; Poprach, K.; Machar, I.; Losík, J.; Gouveia, A.; Tkadlec, Emil

    Brno: Ústav biologie obratlovců AV ČR, 2015 - (Bryja, J.; Řehák, Z.; Zukal, J.). s. 187 ISBN 978-80-87189-18-4. [Zoologické dny. 12.02.2015-13.02.2015, Brno] Institutional support: RVO:68081766 Keywords : barn owl * common vole Subject RIV: EG - Zoology

  18. Barn music at St Donat's castle / Philip Gross

    Index Scriptorium Estoniae

    Gross, Philip, 1952-

    2011-01-01

    Muusikafestivalist "Vale of Glamorgan", mis oli 2010. a. pühendatud Arvo Pärdile. Eesti kammermuusikaansambli Resonabilis kavas oli ka festivali tellimusel valminud uelsi helilooja Gareth Peredur Churchilli "Vocable", mille teksti kirjutas Philip Gross. Festivalikontsertide muljeid leiab Grossi luuletsüklis "Barn music" (avaldatud samas ajakirjanumbris, lk. 42-43)

  19. Aeroallergens in dairy barns near Cooperstown, New York and Rochester, Minnesota

    International Nuclear Information System (INIS)

    We sampled atmospheric barn air using a volumetric air sampler in ten barns near Cooperstown, NY and six barns near Rochester, MN, and, with radioimmunoassays, measured allergens of Aspergillus fumigatus, Thermoactinomyces vulgaris, Micropolyspori faeni, short ragweed, rye grass group I pollen, Alternaria (Alt-1), Dermatophagoides sp. Lepidoglyphus destructor, common insect allergen, mouse urine, rat urine, and cattle epithelium. The most abundant allergen present was A. fumigatus followed by L. destructor. This study provides initial data on barn aerobiology and demonstrates for the first time the abundance of L. destructor allergens in North American dairy barns. More comprehensive study of barns, poultry houses, confinement houses for swine, and other agricultural environments from various geographic locations is needed to define the allergen levels to which millions of farm workers are exposed each day. While most of the allergens were expected, the presence of airborne allergens reactive with antisera to Dermatophagoides suggests indirectly that substantial amounts of pyroglyphid mites are present in some barns

  20. Drinking and Cleaning Water Use in a Dairy Cow Barn

    Directory of Open Access Journals (Sweden)

    Michael Krauß

    2016-07-01

    Full Text Available Water is used in dairy farming for producing feed, watering the animals, and cleaning and disinfecting barns and equipment. The objective of this study was to investigate the drinking and cleaning water use in a dairy cow barn. The water use was measured on a well-managed commercial dairy farm in North-East Germany. Thirty-eight water meters were installed in a barn with 176 cows and two milking systems (an automatic milking system and a herringbone parlour. Their counts were logged hourly over 806 days. On average, the cows in the automatic milking system used 91.1 (SD 14.3 L drinking water per cow per day, while those in the herringbone parlour used 54.4 (SD 5.3 L per cow per day. The cows drink most of the water during the hours of (natural and artificial light in the barn. Previously published regression functions of drinking water intake of the cows were reviewed and a new regression function based on the ambient temperature and the milk yield was developed (drinking water intake (L per cow per day = −27.937 + 0.49 × mean temperature + 3.15 × milk yield (R2 = 0.67. The cleaning water demand had a mean of 28.6 (SD 14.8 L per cow per day in the automatic milking system, and a mean of 33.8 (SD 14.1 L per cow per day in the herringbone parlour. These findings show that the total technical water use in the barn makes only a minor contribution to water use in dairy farming compared with the water use for feed production.

  1. Practical considerations for ventilating calf barns in winter.

    Science.gov (United States)

    Nordlund, Kenneth V

    2008-03-01

    The use of air sampling devices to measure the concentrations of airborne bacteria in clinical investigations and research trials in calf barns has indicated that traditional systems of ventilation are problematic in cold weather. Individual pen designs should have two solid sides, but the front and rear should be as open as possible. Thermal stress should be managed by providing deep bedding and not by enclosing the pen. Air hygiene can be improved by reducing stocking density and using supplemental positive-pressure ventilation systems to deliver small amounts of air to each pen. Implementation of these recommendations can produce calf barns that seem to equal calf hutches in minimizing disease and provide better working conditions for the caregivers. PMID:18299031

  2. Barns bilder av staden : Minecraft, preferenser och lek

    OpenAIRE

    Karlsson, Eva

    2015-01-01

    Barnperspektivet inom fysisk planering har fått större uppmärksamhet de senaste decennierna, och då barns åsikter om miljöer har visat sig vara viktiga men svåra för planerare att tolka testas ständigt nya dialogmetoder för att kommunicera med barn. De senaste åren har datorspelet Minecraft börjat användas för detta, där barnen själva får visualisera och gestalta sina stadsbilder. Detta innebär att tolkningen av dessa bilder sker senare i skaparprocessen än vid annan dialog, varvid frågor om ...

  3. Barn owl (Tyto alba) siblings vocally negotiate resources.

    OpenAIRE

    Roulin, A; Kölliker, M; Richner, H.

    2000-01-01

    Current theory proposes that nestlings beg to signal hunger level to parents honestly, or that siblings compete by escalating begging to attract the attention of parents. Although begging is assumed to be directed at parents, barn owl (Tyto alba) nestlings vocalize in the presence but also in the absence of the parents. Applying the theory of asymmetrical contests we experimentally tested three predictions of the novel hypothesis that in the absence of the parents siblings vocally settle cont...

  4. The occurrence of reptiles in Barn Owl diet in Europe

    OpenAIRE

    Roulin A.; Dubey S

    2012-01-01

    Capsule We present a review of the propensity to eat reptiles in the Barn Owl Tyto alba in Europe. Based on the analysis of 591 published studies reporting 3.07 million prey items identified in pellets, only 2402 reptiles (0.08%) were found. Reptiles were most often captured in southern parts of the European continent and on islands. A large proportion of the 1304 identified reptiles to the species level were nocturnal Gekkonidae (77.1%).

  5. Visual-auditory integration for visual search: a behavioral study in barn owls

    OpenAIRE

    Yael eHazan; Inna eYarin; Yonatan eKra; Hermann eWagner; Yoram eGutfreund

    2015-01-01

    Barn owls are nocturnal predators that rely on both vision and hearing for survival. The optic tectum of barn owls, a midbrain structure involved in selective attention, has been used as a model for studying visual- auditory integration at the neuronal level. However, behavioral data on visual- auditory integration in barn owls are lacking. The goal of this study was to examine if the integration of visual and auditory signals contributes to the process of guiding attention towards salient st...

  6. Design methodology for the robotic milking barn : modelling, simulation, validation and optimization

    OpenAIRE

    Halachmi, I.

    1999-01-01

    The traditional barn design is a milking parlour oriented. To integrate a milking robot the barn should be redesigned according to the robotic milking concept. The entire system (barn design, feeding and cow-traffic routines, management practices) should encourage 'voluntary milking', i.e., it should ensure sufficiently frequent visits of the cow to the robot.An optimal layout should balance animal welfare, on the one hand, and the economic need for high facility utilisation, on the other han...

  7. EMDR-behandling  : Barns och ungdomars upplevelser en kvalitetssäkringsstudie 

    OpenAIRE

    Fredin, Ingela

    2005-01-01

    Föreliggande studie är dels ett led i att kvalitetssäkra EMDR (Eye Movement Desensitization and Reprocessing) som behandlingsmetod för barn och ungdomar och dels att utröna om behandlingen bidragit till ett förbättrat mående. EMDR som behandlingsmetod för barn och ungdomar har stöd i kontrollerade studier, men ytterligare forskning behövs. I den här studien deltog åtta barn och ungdomar med varierande diagnoser, vilka fått EMDR-behandling i barn- och ungdomspsykiatrisk öppenvård. Behandlingen...

  8. Taleteknologi for barn. En kvalitativ studie av fagpersoners erfaringer med kommunikasjonsmateriellet Pegasus.

    OpenAIRE

    Stølen, Mari

    2015-01-01

    Denne studien handler om alternativ og supplerende kommunikasjon, og har sett nærmere på taleteknologi for barn og kommunikasjonsmateriellet Pegasus. Barn med kommunikasjonsvansker har ikke samme forutsetninger som barn med typisk utvikling til å delta i sosialt samspill. Pegasus er utviklet for å hjelpe disse barna til å bli mer aktive i kommunikasjon, lek og samspill med andre. Formålet med studien var å undersøke erfaringer med å bruke Pegasus i samspill med barn med kommunikasjonsvansker....

  9. Air quality in barns for milk-fed calves

    International Nuclear Information System (INIS)

    Seventy per cent of the veal produced in Canada comes from Quebec. This paper reported on the air quality in barns used for milk-fed calves. It is known that air quality inside livestock buildings has an impact on both workers and animals, particularly in winter when air circulation is reduced. In this study, air quality inside barns was studied during the winter, spring and summer. Three types of barns with 3 different types of ventilation typically found in Quebec were evaluated. These included those with preheated corridors, lateral air entries, and central chimneys. Gases were measured in order to determine concentrations and emissions of: ammonia (NH3) which is toxic, colourless and flammable; hydrogen sulfide (H2S) which is very toxic, flammable; carbon dioxide (CO2) which is colourless and odourless; nitrous oxide (N2O) which is colourless and flammable, but harmless to health in the short-term; carbon monoxide (CO) which is colourless, odourless and flammable; and methane (CH4) which is the principal constituent released by animals, and is also colourless, odourless and extremely flammable. When exposed to air, both methane and carbon monoxide can produce an explosive mix especially in an enclosed area. Bacteria, mold, endotoxins, and dust are also present in barns. Samples of gases were analyzed with the help of different portable apparatuses. Results revealed that there are no significant problems with air quality in barns used for milk-fed calves in Quebec. It was determined that the inside temperature was appropriate even during summer periods, and although the relative humidity was higher than the recommended values for the care and handling of farm animals, it was still acceptable. In winter, ammonia was the only gas present in concentrations that reached values of weighted average exposure. Also, concentrations of bacteria were higher during winter. It was suggested that better air ventilation during the winter period would lower ammonia and bacteria

  10. BARNS DELAKTIGHET I FÖRSKOLAN – PÅ DE VUXNAS VILLKOR? : Förskollärares uppfattningar om barns delaktighet i förskolans vardag.

    OpenAIRE

    Eriksson, Anette

    2007-01-01

    SAMMANFATTNING Anette Eriksson Barns delaktighet i förskolan – är den villkorad av de vuxna? - Förskollärares uppfattningar om barns delaktighet i förskolans vardag. Vårterminen 2007 Antal sidor 59 Syftet med denna studie var att undersöka, analysera och beskriva hur förskollärare uppfattar delaktighet i förskolans vardag. En litteratursökning visade att det fanns få studier avseende förskollärares uppfattningar om barns delaktighet i förskolan. Studien är kvalitativ med en innehållsanalys oc...

  11. Barnes Ice Cap South Dome Trilateration Net Survey Data 1970-1984

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Barnes Ice Cap data set contains survey measurements of a network of 43 stakes along a 10 km flow line on the northeast flank of the south dome of the Barnes...

  12. The Stokes Phenomenon, Borel Summation and Mellin-Barnes Regularisation

    CERN Document Server

    Kowalenko, Victor

    2009-01-01

    The Stokes phenomenon refers to the emergence of jump discontinuities in asymptotic expansions at specific rays in the complex plane. This book presents a radical theory for the phenomenon by introducing the concept of regularization. Two methods of regularization, Borel summation and Mellin-Barnes regularization, are used to derive general expressions for the regularized values of asymptotic expansions throughout the complex plane. Though different, both yield identical values, which, where possible, agree with the original functions. Consequently, asymptotics has been elevated to a true disc

  13. Tannin extracts abate ammonia emissions from simulated dairy barn floors.

    Science.gov (United States)

    Powell, J M; Aguerre, M J; Wattiaux, M A

    2011-01-01

    Feeding more tannin and less crude protein (CP) to dairy cows may have synergistic impacts on reducing NH emissions from dairy barns. Three trials using lab-scale ventilated chambers with concrete floors were conducted to determine the impacts on NH emission of tannin and CP feeding, tannin feeding on urease activity in feces, and tannin application directly to the barn floor. For Trial 1, mixtures of feces and urine from lactating Holstein dairy cows () fed four levels (g kg) of dietary tannin extract [a mixture from red quebracho () and chestnut () trees]: 0 tannin (0T), 4.5 (low tannin [LT]), 9.0 (medium tannin [MT]), and 18.0 (high tannin [HT]); each fed at two levels (g kg) of dietary CP: 155 low CP (LCP) and 168 high CP (HCP) were applied to chambers. For Trial 2, urea solution was added to feces obtained from cows fed 0T, MT, and HT at HCP. For Trial 3, tannin amounts equivalent to those fed at 0T, MT, and HT were applied directly to feces-urine mixtures from 0T-HCP. For all trials, NH emissions were measured 1, 3, 6, 12, 24, 36, and 48 h after treatment application. For Trial 1, reductions in NH emission due to tannin feeding were greatest when fed at LCP: The LCP-LT and LCP-HT treatments emitted 30.6% less NH than LCP-0T, and the HCP-LT and HCP-HT treatments emitted 16.3% less NH than HCP-0T. For Trial 2, feeding tannin decreased urease activity in feces, resulting in an 11.5% reduction in cumulative NH loss. For Trial 3, the application of tannin directly to simulated barn floors also apparently decreased urease activity, resulting in an average reduction in cumulative NH emissions of 19.0%. Larger-scale trails are required to ascertain the effectiveness of tannin extracts in abating NH loss from dairy barn floors. PMID:21546676

  14. Oppdragelse etter intensivbehandling av barn : kan eksistensielle kriser endre oppdragelsen?

    OpenAIRE

    2005-01-01

    SAMMENDRAG Problemområdet: Når et barn blir akutt/kritisk syk og må intensivbehandles, er det godt mulig at foreldrene ved siden av sterke emosjoner, opplever en krise av eksistensiell art der spørsmål om livsverdier kan oppstå. Det kan være mulig at samspillet innad i familien og foreldrenes oppdragelsespraksis endres når familien kommer hjem. Min erfaring fra klinisk praksis, fra teori og forskningsartikler kan tyde på det. Målet er å få fram mulige utfordringer for familien etter at et ...

  15. Few-cosine spherical codes and Barnes-Wall lattices

    OpenAIRE

    Griess, Jr., Robert L.

    2006-01-01

    Using Barnes-Wall lattices and 1-cocycles on finite groups of monomial matrices, we give a procedure to construct tricosine spherical codes. This was inspired by a 14-dimensional code which Ballinger, Cohn, Giansiracusa and Morris discovered in studies of the universally optimal property. It has 64 vectors and cosines $-3/7, -1/7, 1/7$. We construct the {\\it Optimism Code}, a 4-cosine spherical code with 256 unit vectors in 16-dimensions. The cosines are $0, 1/4, -1/4, -1$. Its automorphism g...

  16. Lung responses to secondary endotoxin challenge in rats exposed to pig barn air

    Directory of Open Access Journals (Sweden)

    Townsend Hugh GG

    2008-10-01

    Full Text Available Abstract Background Swine barn air contains endotoxin and many other noxious agents. Single or multiple exposures to pig barn air induces lung inflammation and loss of lung function. However, we do not know the effect of exposure to pig barn air on inflammatory response in the lungs following a secondary infection. Therefore, we tested a hypothesis that single or multiple exposures to barn air will result in exaggerated lung inflammation in response to a secondary insult with Escherichia coli LPS (E. coli LPS. Methods We exposed Sprague-Dawley rats to ambient (N = 12 or swine barn air (N = 24 for one or five days and then half (N = 6/group of these rats received intravenous E. coli LPS challenge, observed for six hours and then euthanized to collect lung tissues for histology, immunohistochemistry and ELISA to assess lung inflammation. Results Compared to controls, histological signs of lung inflammation were evident in barn exposed rat lungs. Rats exposed to barn air for one or five days and challenged with E. coli LPS showed increased recruitment of granulocytes compared to those exposed only to the barn. Control, one and five day barn exposed rats that were challenged with E. coli LPS showed higher levels of IL-1β in the lungs compared to respective groups not challenged with E. coli LPS. The levels of TNF-α in the lungs did not differ among any of the groups. Control rats without E. coli LPS challenge showed higher levels of TGF-β2 compared to controls challenged with E. coli LPS. Conclusion These results show that lungs of rats exposed to pig barn air retain the ability to respond to E. coli LPS challenge.

  17. Moving Objects in the Barn Owl's Auditory World.

    Science.gov (United States)

    Langemann, Ulrike; Krumm, Bianca; Liebner, Katharina; Beutelmann, Rainer; Klump, Georg M

    2016-01-01

    Barn owls are keen hunters of moving prey. They have evolved an auditory system with impressive anatomical and physiological specializations for localizing their prey. Here we present behavioural data on the owl's sensitivity for discriminating acoustic motion direction in azimuth that, for the first time, allow a direct comparison of neuronal and perceptual sensitivity for acoustic motion in the same model species. We trained two birds to report a change in motion direction within a series of repeating wideband noise stimuli. For any trial the starting point, motion direction, velocity (53-2400°/s), duration (30-225 ms) and angular range (12-72°) of the noise sweeps were randomized. Each test stimulus had a motion direction being opposite to that of the reference stimuli. Stimuli were presented in the frontal or the lateral auditory space. The angular extent of the motion had a large effect on the owl's discrimination sensitivity allowing a better discrimination for a larger angular range of the motion. In contrast, stimulus velocity or stimulus duration had a smaller, although significant effect. Overall there was no difference in the owls' behavioural performance between "inward" noise sweeps (moving from lateral to frontal) compared to "outward" noise sweeps (moving from frontal to lateral). The owls did, however, respond more often to stimuli with changing motion direction in the frontal compared to the lateral space. The results of the behavioural experiments are discussed in relation to the neuronal representation of motion cues in the barn owl auditory midbrain. PMID:27080662

  18. Befrämjande av delaktighet hos barn - finns det en genusskillnad?

    OpenAIRE

    Aalto-Setälä, Kira

    2012-01-01

    Syftet med detta examensarbete är att ur ett genusperspektiv observera på vilka sätt barn bereds möjlighet till delaktighet vid fysisk aktivitet. Den teoretiska referensramen består av teorier om: könsmedvetenhet i verksamhet med barn, genus och könsroller, socialpedagogisk grundsyn, socialpedagogiskt förhållningssätt, bemötande och kommunikation samt ledarrollen och växelverkan. Frågeställningarna är: 1) På vilka sätt befrämjar ledarna barns delaktighet i fysisk aktivitet? och 2) Finns det e...

  19. Överviktiga barns upplevelser av hälsa och lidande

    OpenAIRE

    Ekstrand, Magnus; Ekstrand, Irina

    2010-01-01

    Bakgrund: I bakgrunden beskrivs viktiga begrepp som hälsa, lidande, övervikt, konsekvenser av övervikt, behandling, utsatthet och betydelse av aktivitet. Detta för att läsaren ska kunna förstå vidden av problemet. Studien kommer att inrikta sig på överviktiga barn och ungdomar.Problem: Övervikt hos barn och ungdomar är ett växande problem som leder till flera negativa konsekvenser, många fysiska men även psykiska, andliga och sociala.Syfte: Att beskriva överviktiga barn och ungdomars upplevel...

  20. The open-quotes Barn Bookclose quotes on-line

    International Nuclear Information System (INIS)

    Experimental nuclear reaction cross-section data are available free of charge through the National Nuclear Data Center (NNDC) On-line Service CSISRS database and may be written onto an Output file or viewed on the user's terminal either in the form of plots or as tabulated data. Evaluated data from the ENDF database may be included on the plots. A recent upgrade allows the user to plot the data in open-quotes Barn Bookclose quotes format. The NNDC on-line system may be accessed via telnet to BNLND2.DNE.BNL.GOV, password NNDC, or through the World Wide Web: http://www.nndc.bnl.gov. First-time users may browse the system using the authorization code GUEST

  1. Improvement of directionality and sound-localization by internal ear coupling in barn owls

    DEFF Research Database (Denmark)

    Wagner, Hermann; Christensen-Dalsgaard, Jakob; Kettler, Lutz;

    Mark Konishi was one of the first to quantify sound-localization capabilities in barn owls. He showed that frequencies between 3 and 10 kHz underlie precise sound localization in these birds, and that they derive spatial information from processing interaural time and interaural level differences....... However, despite intensive research during the last 40 years it is still unclear whether and how internal ear coupling contributes to sound localization in the barn owl. Here we investigated ear directionality in anesthetized birds with the help of laser vibrometry. Care was taken that anesthesia and the...... time difference in the low-frequency range, barn owls hesitate to approach prey or turn their heads when only low-frequency auditory information is present in a stimulus they receive. Thus, the barn-owl's sound localization system seems to be adapted to work best in frequency ranges where interaural...

  2. Barn i familjer med missbruksproblem : En kvalitativ studie om daghemmets roll när ett barn kommer från en familj med missbruksproblem

    OpenAIRE

    Ålgars, Emma

    2010-01-01

    Ämnesområdet och temat för mitt arbete är barn i familjer med missbruksproblem. Syftet med min studie är att förstå vad det som barn innebär att leva i en familj med missbruksproblem och att se vilka konsekvenser det har för barnet. Jag vill även få reda på vad man på daghem kan göra för att stöda barn samt deras föräldrar i familjer med missbruksproblem. Mina tre frågeställningar för arbetet är; Hur ser barnets situation ut i en familj med missbruksproblem? Hur kan man på daghem identifiera ...

  3. Is a new version of philosophical pragmatism necessary? A reply to Barnes-Holmes

    OpenAIRE

    Leigland, Sam

    2003-01-01

    Barnes-Holmes (2000) discussed certain issues regarding philosophy, pragmatism, and behavior analysis, and offered a “behavioral pragmatism” based on or derived from behavior-analytic perspectives. In a comparison of certain philosophical views, Quine's concept of observation sentences was employed for representing pragmatism, but this concept is not sufficiently representative of the literature of philosophical pragmatism to warrant the broad conclusions drawn by Barnes-Holmes. Further, alth...

  4. Developmental Changes Underlying the Formation of the Specialized Time Coding Circuits in Barn Owls (Tyto alba)

    OpenAIRE

    Kubke, M. Fabiana; Massoglia, Dino P.; Carr, Catherine E.

    2002-01-01

    Barn owls are capable of great accuracy in detecting the interaural time differences (ITDs) that underlie azimuthal sound localization. They compute ITDs in a circuit in nucleus laminaris (NL) that is reorganized with respect to birds like the chicken. The events that lead to the reorganization of the barn owl NL take place during embryonic development, shortly after the cochlear and laminaris nuclei have differentiated morphologically. At first the developing owl’s auditory brainstem exhibit...

  5. Designing the optimal robotic milking barn: applying a queuing network approach

    OpenAIRE

    Halachmi, I.; Adan, I. J. B. F.; Wal, J. van der; van Beek, P.; Heesterbeek, J.A.P.

    2003-01-01

    The design of various conventional dairy barns is based on centuries of experience, but there is hardly any experience with robotic milking barns (RMB). Furthermore, as each farmer has his own management practices, the optimal layout is 'site dependent'. A new universally applicable design methodology has been developed, to overcome this lack of experience with RMBs and to facilitate the designing of their optimal layout. This model for optimizing facility allocation, based on cow behaviour, ...

  6. The Air Quality in Transylvanian Dairy Barns with Tie-Stalls

    Directory of Open Access Journals (Sweden)

    POPESCU Silvana

    2010-12-01

    Full Text Available The aim of this work was to assess the quality of the air in dairy barns with tie-stalls, based on the total numberof mesophilic bacteria and on the concentrations of noxious gases (ammonia, carbon dioxide and hydrogen sulphide.We also studied the correlations between the main indicators of the air quality and the parameters of the microclimate(temperature, relative humidity and air flow velocity. Forty dairy cow barns were investigated in Transylvania in thecold season. The parameters were tested using specific methods. The numbers of the total mesophilic bacteria in the airvaried between 2.50 x 104 cfu/m3 and 3.36 x 105 cfu/m3, with a main value of 1.52 x 105 cfu/m3. The ammonia waspresent in all of the barns, having concentrations from 3.00 ppm to 37.00 ppm, with a mean value of 22.47 ppm.Ammonia exceeded the threshold limit in 57.5% of the investigated barns. The carbon dioxide was below the thresholdlimit in all of the barns and no hydrogen sulphide was found. Positive correlations were demonstrated between theammonia concentration and the air temperature (Spearman r = 0.451, p <0.05 and between the ammonia and therelative humidity of the air (Spearman r = 0.634, p <0.05. The air quality was low in more than a half of theinvestigated barns due the high concentration of the ammonia.

  7. En sammenligning av effekten av Ritalin, Dexedrine og placebo hos et utvalg barn og unge med diagnosen ADHD

    OpenAIRE

    2007-01-01

    Hensikten med denne studien var å sammenligne effekten av Ritalin og Dexedrine hos et utvalg barn med attention deficit/hyperactivity disorder (ADHD). Tidligere studier har funnet at ved å la hvert barn prøve begge medikamentene økes sannsynligheten for positiv effekt og reduserer sannsynligheten for bivirkninger. Noen barn responderer bra på Ritalin men ikke på Dexedrine, og omvendt. Denne studien har et randomisert dobbel-blind kryssover design der vi sammenligner Dexedrine, Ritalin og...

  8. Barnes maze performance of Octodon degus is gender dependent.

    Science.gov (United States)

    Popović, Natalija; Madrid, Juan Antonio; Rol, María Angeles; Caballero-Bleda, María; Popović, Miroljub

    2010-10-15

    Gender differences in spatial navigation have been widely reported in nocturnal rodent species. Here, for the first time we report gender differences in spatial learning and memory of Octodon degus, a long-lived diurnal hystricomorph rodent. In the present study, 16 months old male and female O. degus were tested in the 18-holes Barnes circular maze. The acquisition session consisted of four daily 4 min trials, during 10 days. Seven days later, the retention test was performed. To avoid the effect of hormonal fluctuation on spatial navigation, both the acquisition and the retention tests, were performed in 21-day regular cycling females in a period that corresponds to the diestrus phase of the estrus cycle. At the beginning of the acquisition, female degus were significantly slower than males to find the escape hole, but the situation reversed afterwards. Moreover, during the course of acquisition, females made significantly less reference memory errors, working memory errors as well as omission errors, than males. In both sexes, motivation and learning ceiling effects were reached at days 5-6 of the training. During the acquisition, females used more frequently a spatial strategy, while males preferably applied either serial, random or opposite strategies. The observed cognitive differences between male and female O. degus existed only during the acquisition period but not during the retention, indicating that acquisition and consolidation are differently influenced by gender. PMID:20385170

  9. Sleep and vigilance linked to melanism in wild barn owls.

    Science.gov (United States)

    Scriba, M F; Rattenborg, N C; Dreiss, A N; Vyssotski, A L; Roulin, A

    2014-10-01

    Understanding the function of variation in sleep requires studies in the natural ecological conditions in which sleep evolved. Sleep has an impact on individual performance and hence may integrate the costs and benefits of investing in processes that are sensitive to sleep, such as immunity or coping with stress. Because dark and pale melanic animals differentially regulate energy homeostasis, immunity and stress hormone levels, the amount and/or organization of sleep may covary with melanin-based colour. We show here that wild, cross-fostered nestling barn owls (Tyto alba) born from mothers displaying more black spots had shorter non-REM (rapid eye movement) sleep bouts, a shorter latency until the occurrence of REM sleep after a bout of wakefulness and more wakefulness bouts. In male nestlings, the same sleep traits also correlated with their own level of spotting. Because heavily spotted male nestlings and the offspring of heavily spotted biological mothers switched sleep-wakefulness states more frequently, we propose the hypothesis that they could be also behaviourally more vigilant. Accordingly, nestlings from mothers displaying many black spots looked more often towards the nest entrance where their parents bring food and towards their sibling against whom they compete. Owlets from heavily spotted mothers might invest more in vigilance, thereby possibly increasing associated costs due to sleep fragmentation. We conclude that different strategies of the regulation of brain activity have evolved and are correlated with melanin-based coloration. PMID:25056556

  10. Memory Revisited in Julian Barnes's "The Sense of an Ending"

    Directory of Open Access Journals (Sweden)

    Maricel Oró Piqueras

    2014-01-01

    Full Text Available An accumulation of years brings with it an accumulation of experiences. The revision of such experiences usually becomes more recurrent after retiremen t, a transition time from one period of life to another and, as such, a time in which we, human being s, have a tendency to take stock of our lives. This is actually one of the main issues present in Julian Barnes's last novel The Sense of an Ending (2011 . When the main protagonist, a retired man quite comfortable and contented with his present life, receives an unexpected inheritance from the mother of a girlfriend from his university years, he is forced to track down a part of his life that he had left a t the back of his mind a long time ago. As he explains his story, the protagonist and narrator of the novel raises a number of questions related to the quality and func tion of memory as one gets into old age . He experiments the unreliability of memory and questions to what extent me mory is constructed through the remembered emotions that invaded him over that episode of his life rather than through the events as they actually took place. On the other hand, the act of revisiting and revising that specific ep isode, brings with it feelings of guilt and remorse as the protagonist realises that his past acts were not as noble as he remembered them to be. However, these acts are part of the past and they cannot be changed; thus, another question that the novel rai ses is how to account for those actions of which one does not feel proud and, more importantly, how to manage those bad memories as one gets older.

  11. Memory Revisited in Julian Barnes's The Sense of an Ending

    Directory of Open Access Journals (Sweden)

    Maricel Oró Piqueras

    2014-02-01

    Full Text Available An accumulation of years brings with it an accumulation of experiences. The revision of such experiences usually becomes more recurrent after retirement, a transition time from one period of life to another and, as such, a time in which we, human beings, have a tendency to take stock of our lives. This is actually one of the main issues present in Julian Barnes's last novel The Sense of an Ending (2011. When the main protagonist, a retired man quite comfortable and contented with his present life, receives an unexpected inheritance from the mother of a girlfriend from his university years, he is forced to track down a part of his life that he had left at the back of his mind a long time ago. As he explains his story, the protagonist and narrator of the novel raises a number of questions related to the quality and function of memory as one gets into old age. He experiments the unreliability of memory and questions to what extent memory is constructed through the remembered emotions that invaded him over that episode of his life rather than through the events as they actually took place. On the other hand, the act of revisiting and revising that specific episode, brings with it feelings of guilt and remorse as the protagonist realises that his past acts were not as noble as he remembered them to be. However, these acts are part of the past and they cannot be changed; thus, another question that the novel raises is how to account for those actions of which one does not feel proud and, more importantly, how to manage those bad memories as one gets older

  12. An example of a method to wirelessly transfer measurement data from cows in a free stall barn

    OpenAIRE

    Järvinen, M.; Sutinen, V.; Martiskainen, P.; Rehu, J.; Korkalainen, M.; Känsälä, K.; Mononen, J.

    2010-01-01

    Here we describe a wireless data measurement and transfer system that operates within a free stall barn. We report also the reliability of the system. This system was designed and built in Very Intelligent Cow Barn project in 2006-2007.

  13. Matvägran hos barn : En medicinsk översikt och kritisk analys samt fallstudier

    OpenAIRE

    Leander, Kajsa

    2012-01-01

    Ätproblem hos barn är relativt vanliga och existerar både hos i övrigt friska barn och hos barn med andra sjukdomar och diagnoser. I vissa fall är ätproblemen så allvarliga att de leder till malnutrition. Ofta delas ätproblem in i kategorier beroende på om man tycker sig se en medicinsk orsak eller inte, man skiljer därmed på organiska och icke-organiska problem. Detta arbete fokuserar främst på det som i litteraturen brukar kallas matvägran. Syftet var att belysa området i stort genom att pr...

  14. Djurlåda med rollkort : - Rollbyte som resiliensstärkande metod bland barn

    OpenAIRE

    Lundberg, Maria

    2010-01-01

    Syftet med examensarbetet är att beskriva hur rollbyte kan användas som en resiliensstärkande metod bland barn. Frågeställningar i arbetet är: vad är resiliens, vad är rollbyte och på vilket sätt kan rollbyte fungera som resiliensstärkande metod. Teoridelen i arbetet behandlar resiliens, social kompetens, empati och rollbyte. Den tillhörande produkten, Djurlådan, består av en låda med rollkort. Produkten är avsedd för barn i 5 års ålder på daghem. Resiliens handlar om att vissa barn k...

  15. Prey composition modulates exposure risk to anticoagulant rodenticides in a sentinel predator, the barn owl.

    Science.gov (United States)

    Geduhn, Anke; Esther, Alexandra; Schenke, Detlef; Gabriel, Doreen; Jacob, Jens

    2016-02-15

    Worldwide, small rodents are main prey items for many mammalian and avian predators. Some rodent species have pest potential and are managed with anticoagulant rodenticides (ARs). ARs are consumed by target and non-target small mammals and can lead to secondary exposure of predators. The development of appropriate risk mitigation strategies is important and requires detailed knowledge of AR residue pathways. From July 2011 to October 2013 we collected 2397 regurgitated barn owl (Tyto alba) pellets to analyze diet composition of owls on livestock farms in western Germany. 256 of them were fresh pellets that were collected during brodifacoum baiting. Fresh pellets and 742 liver samples of small mammals that were trapped during baiting in the same area were analyzed for residues of ARs. We calculated exposure risk of barn owls to ARs by comparing seasonal diet composition of owls with AR residue patterns in prey species. Risk was highest in autumn, when barn owls increasingly preyed on Apodemus that regularly showed AR residues, sometimes at high concentrations. The major prey species (Microtus spp.) that was consumed most frequently in summer had less potential to contribute to secondary poisoning of owls. There was no effect of AR application on prey composition. We rarely detected ARs in pellets (2 of 256 samples) but 13% of 38 prey individuals in barn owl nests were AR positive and substantiated the expected pathway. AR residues were present in 55% of 11 barn owl carcasses. Fluctuation in non-target small mammal abundance and differences in AR residue exposure patterns in prey species drives exposure risk for barn owls and probably other predators of small mammals. Exposure risk could be minimized through spatial and temporal adaption of AR applications (avoiding long baiting and non-target hot spots at farms) and through selective bait access for target animals. PMID:26657360

  16. Vi trenger longitudinelle epidemiologiske undersøkelser av psykiske lidelser og utviklingsforstyrrelser hos barn

    OpenAIRE

    Bente Gjærum; Torunn S. Nøvik

    2009-01-01

     sAMMENDRAGArtikkelen gjennomgår nyere forekomststudier for utviklings- og atferdsforstyrrelser, nevrologiske og psykiskelidelser hos barn og ungdom. Forfatterne peker på den betydelige komorbiditet som sees for disse grupperav tilstander, og den tverrfaglige bredde som synes nødvendig for å forstå hvilke faktorer og mekanismer sompåvirker barns utvikling og psykiske helse. I tillegg refereres nyere forskning på forløp og varighet vedavvikende utvikling i oppveksten, samt eksempler på undersø...

  17. Endogenous anxiety and stress responses in water maze and Barnes maze spatial memory tasks

    OpenAIRE

    Harrison, F. E.; Hosseini, A.H.; McDonald, M.P.

    2008-01-01

    The effects of abnormally high or low stress on learning are well established. The Barnes maze and Morris water maze are two commonly-used tests of spatial memory, of which the water maze is considered more stressful; however, until now this has not been demonstrated empirically. In the present study, mice matched for performance on commonly-used anxiety tasks were trained on either the Barnes maze or water maze or received no cognitive testing. Water-maze training induced greater increases i...

  18. Food habits of common barn-owls along an elevational gradient in Andean Argentine Patagonia

    OpenAIRE

    Travaini, Alejandro; Donázar, José A.; Ceballos, Olga; Rodríguez, Alejandro; Hiraldo, F.; Delibes, M.

    1997-01-01

    We evaluated the diet of Common Barn-owls (Tyto alba) along an elevational gradient in Argentine Patagonia. Small mammals (mainly rodents) were the main prey accounting for 93.2% of total prey items. Consumption of rodents appeared to be dependent on their availability. Sizes of mam­ malian prey were variable but most ranged from 10—100 g in body mass. We concluded that the diet of these barn owls could be used as an index of cricetid rodent populations along ...

  19. Parent Management Training - en foreldreveiledningsmetodefor behandling av barn med atferdsproblemer. Teori, behandlingsprogram og implementering i Norge

    OpenAIRE

    Apelseth, Eva Fohlin; Amlie, Christine

    2001-01-01

    Antisosial atferd blant barn og ungdom er et stort og økende helsemessig og økonomisk problem. Parent Management Training – Oregon (PMT-O), et behandlings- og forebyggingsprogram for familier med barn som fremviser antisosial adferd, blir for tiden implementert i Norge som ledd i satsingen på psykisk helsevern. PMT-O er basert på ”social learning interaction theory”, utviklet av Patterson og medarbeidere ved Oregon Social Learning Center. PMT-O er et detaljert program for styrking av foreldre...

  20. Variation in sperm morphometry and sperm competition among barn swallow (Hirundo rustica) populations

    Czech Academy of Sciences Publication Activity Database

    Laskemoen, T.; Albrecht, Tomáš; Bonisoli-Alquati, A.; Cepák, J.; De Lope, F.; Hermosell, I. G.; Johannessen, L. E.; Kleven, O.; Marzal, A.; Mousseau, T. A.; Moller, A. P.; Robertson, R. J.; Rudolfsen, G.; Saino, N.; Vortman, Y.; Lifjeld, J. T.

    2013-01-01

    Roč. 67, č. 2 (2013), s. 301-309. ISSN 0340-5443 R&D Projects: GA ČR(CZ) GAP506/12/2472 Institutional support: RVO:68081766 Keywords : Barn swallow * Extrapair paternity * Hirundo rustica * Sperm competition * Sperm size Subject RIV: EG - Zoology Impact factor: 3.049, year: 2013

  1. Michael E. Barnes: Award for Distinguished Professional Contributions to Institutional Practice

    Science.gov (United States)

    American Psychologist, 2012

    2012-01-01

    Presents a short biography on the winner of the American Psychological Association's Award for Distinguished Professional Contributions to Institutional Practice. The 2012 winner is Michael E. Barnes for his pioneering leadership, dedication, and distinguished contributions to juvenile justice. As chief psychologist of the Superior Court of the…

  2. Low frequency eardrum directionality in the barn owl induced by sound transmission through the interaural canal

    DEFF Research Database (Denmark)

    Kettler, Lutz; Christensen-Dalsgaard, Jakob; Larsen, Ole Næsbye;

    2016-01-01

    The middle ears of birds are typically connected by interaural cavities that form a cranial canal. Eardrums coupled in this manner may function as pressure difference receivers rather than pressure receivers. Hereby, the eardrum vibrations become inherently directional. The barn owl also has a la...

  3. Non-planar Feynman diagrams and Mellin-Barnes representations with AMBRE 3.0

    Energy Technology Data Exchange (ETDEWEB)

    Dubovyk, Ievgen [Institute of Electrophysics and Radiation Technologies, Kharkiv (Ukraine); Gluza, Janusz [Univ. of Silesia, Katowice (Poland). Inst. of Physics; Riemann, Tord

    2016-04-15

    We introduce the Mellin-Barnes representation of general Feynman integrals and discuss their evaluation. The Mathematica package AMBRE has been recently extended in order to cover consistently non-planar Feynman integrals with two loops. Prospects for the near future are outlined. This write-up is an introduction to new results which have also been presented elsewhere.

  4. Systematics and distribution of the giant fossil barn owls of the West Indies (Aves: Strigiformes: Tytonidae).

    Science.gov (United States)

    Suárez, William; Olson, Storrs L

    2015-01-01

    After reviewing the systematics and distribution of the extinct West Indian taxa of Tytonidae (Tyto) larger than the living barn owl Tyto alba (Scopoli), we reached the following conclusions: (1) the species T. ostologa Wetmore (1922) is the only giant barn owl known so far from Hispaniola; (2) T. pollens Wetmore (1937) was a somewhat larger and even more robust representative of T. ostologa known from the Great Bahama Bank and Cuba; (3) the very rare species T. riveroi Arredondo (1972b) is here synonymized with T. pollens; (4) the smallest taxon of these giant barn owls is T. noeli Arredondo (1972a), which is widespread and abundant in Quaternary deposits of Cuba and is here reported for the first time from two cave deposits in Jamaica; (5) the only large barn owl named so far from the Lesser Antilles is T. neddi Steadman & Hilgartner (1999), which is here synonymized with T. noeli; (6) a new taxon from Cuba, T. cravesae new species, which in size approached the linear dimensions of T. ostologa, is named and described herein. PMID:26624114

  5. First observation of African tigerfish Hydrocynus vittatus predating on barn swallows Hirundo rustica in flight.

    Science.gov (United States)

    O'Brien, G C; Jacobs, F; Evans, S W; Smit, N J

    2014-01-01

    A population of African tigerfish Hydrocynus vittatus from the Schroda Dam, actively prey on barn swallows Hirundo rustica in flight. This behaviour was discovered during a radio telemetry study and documented using a motion picture video camera. These results show that an avivorous diet is a part of the feeding biology of H. vittatus, and may occur in other populations. PMID:24354922

  6. Personcentrerad omvårdnad för familjer där barn har ADHD En litteraturstudie

    OpenAIRE

    Malmberg, Claes

    2016-01-01

    Bakgrund: Attention deficit hyperactivity disorder (ADHD) är den vanligaste neuropsykiatriska diagnosen bland barn, prevalens ca 5%. ADHD kan skapa en myriad svårigheter som ibland är svåra att koppla till kärnsymtomen. Miljö och bemötande är viktiga faktorer. Syfte: Syftet med följande studie har varit att beskriva hur specialistsjuksköterskan i psykiatrisk vård kan anpassa den personcentrerade omvårdnaden för barn och familjer där barn har ADHD. Metod: Litteraturstudie av tolv kvalitativa a...

  7. Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hogerton, John

    1964-01-01

    This pamphlet describes how reactors work; discusses reactor design; describes research, teaching, and materials testing reactors; production reactors; reactors for electric power generation; reactors for supply heat; reactors for propulsion; reactors for space; reactor safety; and reactors of tomorrow. The appendix discusses characteristics of U.S. civilian power reactor concepts and lists some of the U.S. reactor power projects, with location, type, capacity, owner, and startup date.

  8. Sex steroid hormones in barn swallow (Hirundo rustica) populations at a dioxin contaminated site in northeast Louisiana

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This study compares the gonadal sex steroid hormone levels (i.e., estradiol, total estrogen, and testosterone) in Louisiana barn swallows (Hirundo rustica) that...

  9. Socionomens fostringsstöd till föräldrar med överviktiga barn-en litteraturstudie

    OpenAIRE

    Johanson, Emma

    2012-01-01

    Syftet med denna studie är att belysa vad föräldrarna kan göra annorlunda i sin fostran för att förebygga att deras barn blir överviktiga eller stöda deras barn om de redan är överviktiga. Mina frågeställningar är; Hur kan föräldrar i fostran förebygga barns övervikt? Hur kan en socionom stöda föräldrar i denna typ av fostran? Den teoretiska referensramen är fostran, bemötande av överviktiga barn och föräldrar och empowerment. Detta arbete är en litteraturstudie och analysmetoden är innehålls...

  10. Mass depopulation of laying hens in whole barns with liquid carbon dioxide: evaluation of welfare impact.

    Science.gov (United States)

    Turner, P V; Kloeze, H; Dam, A; Ward, D; Leung, N; Brown, E E L; Whiteman, A; Chiappetta, M E; Hunter, D B

    2012-07-01

    Appropriate emergency disaster preparedness is a key priority for agricultural agencies to allow effective response to serious avian disease outbreaks. There is a need to develop rapid, humane, and safe depopulation techniques for poultry that are widely applicable across a range of farm settings. Whole barn depopulation with carbon dioxide (CO(2)) has been investigated as a humane and efficient means of killing large numbers of birds in the event of a reportable disease outbreak. It has also been considered as a method for depopulating barns containing end-of-lay hens, particularly when there is limited local slaughter and rendering capacity. Determining the best method of humanely killing large flocks of birds remains problematic and is being investigated by a coordinated international effort. While whole barn depopulation using CO(2) inhalation has been explored, physiologic responses of chickens have not been characterized in field settings and assessment of animal welfare is hampered without this information. In this study, 12 cull laying hens were surgically instrumented with telemetry transmitters to record electroencephalographs, electrocardiographs, body temperature, and activity during 2 large-scale field CO(2) euthanasia trials of end-of-lay hens. The day following surgery, instrumented hens were placed in barns with other birds, barns were sealed, and animals were killed by CO(2) inhalation delivered via a specially designed liquid CO(2) manifold. Instrumented birds were monitored by infrared thermography, and ambient temperature, CO(2), and O(2) concentrations were recorded. Results from these studies indicate that instrumented hens lost consciousness within 2 min of CO(2) levels reaching 18 to 20%. Mild to moderate head shaking, gasping, and 1 to 2 clonic muscle contractions were noted in hens before unconsciousness; however, brain death followed rapidly (benefits suggest clear advantages over catching and transporting cull hens for slaughter. The

  11. ”Mitt barns medicin” : En kvalitativ studie om föräldrars upplevelser av deras barns behandling med Modifierad Atkins Diet och ketogenkost.

    OpenAIRE

    Holmström, Annika; Mårtensson, Lotta

    2012-01-01

    BAKGRUND Modifierad Atkins Diet (MAD) och ketogenkost är kostbehandlingar som ordineras till barn med svårbehandlad epilepsi. Andra patientgrupper som behandlas med dessa dieter är patienter med glukostransportprotein typ 1-brist. Kostbehandlingarna är kolhydratfattiga och fettrika. I Sverige finns fyra sjukhus som arbetar med MAD och ketogenkost. I dagsläget saknas studier som beskriver hur behandlingarna upplevs av berörda familjer. SYFTE Syftet med studien var att utforska hur föräldrar ti...

  12. Remaining Sites Verification Package for the 141-C Large Animal Barn and Biology Laboratory (Hog Barn). Attachment to Waste Site Reclassification Form 2006-027

    International Nuclear Information System (INIS)

    The 141-C waste site is a former large animal barn and biology laboratory within the 100-F Area experimental animal farm. Strontium-90, arsenic, and multiple polycyclic aromatic hydrocarbons were detected within residual demolition debris at concentrations exceeding cleanup criteria. The site has been remediated by removing approximately 900 bank cubic meters of soil and debris within the former building footprint to the Environmental Restoration Disposal Facility. The results of verification sampling demonstrated that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also showed that residual contaminant concentrations are protective of groundwater and the Columbia River

  13. Scalable Parallel Formulations of the Barnes-Hut Method for n-Body Simulations

    Science.gov (United States)

    Grama, Ananth Y.; Kumar, Vipin; Sameh, Ahmed

    In this paper, we present two new parallel formulations of the Barnes-Hut method. These parallel formulations are especially suited for simulations with irregular particle densities. We first present a parallel formulation that uses a static partioning of the domain and assignment of subdomains to processors. We demonstrate that this scheme delivers acceptable load balance, and coupled with two collective communication operations, it yields good performance. We present a second parallel formulation which combines static decomposition of the domain with an assignment of subdomains to processors based on Morton ordering. This alleviates the load imbalance inherent in the first scheme. The second parallel formulation is inspired by two currently best known parallel algorithms for the Barnes-Hut method. We present an experimental evaluation of these schemes on a 256 processor nCUBE2 parallel computer for an astrophysical simulation.

  14. Scalable parallel formulations of the Barnes-Hut method for n-body simulations

    Energy Technology Data Exchange (ETDEWEB)

    Grama, A.Y.; Kumar, V.; Sameh, A. [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Computer Science

    1994-12-31

    In this paper, the authors present two new parallel formulations of the Barnes-Hut method. These parallel formulations are especially suited for simulations with irregular particle densities. They first present a parallel formulation that uses a static partitioning of the domain and assignment of subdomains to processors. They demonstrate that this scheme delivers acceptable load balance, and coupled with two collective communication operations, it yields good performance. They present a second parallel formulation which combines static decomposition of the domain with an assignment of subdomains to processors based on Morton ordering. This alleviates the load imbalance inherent in the first scheme. The second parallel formulation is inspired by two currently best known parallel algorithms for the Barnes-Hut method.

  15. Multimodal signalling in the North American barn swallow: a phenotype network approach.

    Science.gov (United States)

    Wilkins, Matthew R; Shizuka, Daizaburo; Joseph, Maxwell B; Hubbard, Joanna K; Safran, Rebecca J

    2015-10-01

    Complex signals, involving multiple components within and across modalities, are common in animal communication. However, decomposing complex signals into traits and their interactions remains a fundamental challenge for studies of phenotype evolution. We apply a novel phenotype network approach for studying complex signal evolution in the North American barn swallow (Hirundo rustica erythrogaster). We integrate model testing with correlation-based phenotype networks to infer the contributions of female mate choice and male-male competition to the evolution of barn swallow communication. Overall, the best predictors of mate choice were distinct from those for competition, while moderate functional overlap suggests males and females use some of the same traits to assess potential mates and rivals. We interpret model results in the context of a network of traits, and suggest this approach allows researchers a more nuanced view of trait clustering patterns that informs new hypotheses about the evolution of communication systems. PMID:26423842

  16. Avian pox virus infection in a common barn owl (Tyto alba in southern Brazil

    Directory of Open Access Journals (Sweden)

    Gilberto D. Vargas

    2011-07-01

    Full Text Available A young common barn owl (Tyto alba was referred to the Núcleo de Reabilitação da Fauna Silvestre (Nurfs, Federal University of Pelotas (UFPel, after been found in a barn of a brick factory in the urban area of Pelotas, Rio Grande do Sul, Brazil. The bird was apathic, weak and with crusty lesions in the featherless areas (eyes, beak, legs, and died soon after arrival at Nurfs. Necropsy and histopathological examination of the lesions were carried out. The hyperplasia and hypertrophy of the cutaneous lesions, several eosinophilic intracyto-plasmic inclusion bodies in epithelial cells (Bollinger bodies, as well as particles characteristic of poxvirus, observed by electronic microscopy, confirmed the infection by avian poxvirus, what highlights the importance of Tyto alba as carrier of the virus in the wild.

  17. Geographic variation in sexual selection and implications for speciation in the Barn Swallow

    Institute of Scientific and Technical Information of China (English)

    Elizabeth SC Scordato; Rebecca J Safran

    2015-01-01

    Barn Swal ows (Hirundo rustica), a group of passerine birds comprised of six closely related subspecies, are well known throughout their nearly worldwide distribution, in part because of their close association with human settlements. A tractable species for both individual-based and population-level studies, Barn Swallows are a prominent model system in evolutionary, ecological, and behavioral research. Here we review work on sexual selection and population divergence in this species complex, focusing on comparative studies among populations and subspecies. We summarize variation in the targets of mate choice and in the information conveyed by sexually selected traits, and conclude that the benefits advertised by different traits may vary geographical y. Finally, we consider the role of sexual selection as a driver of population divergence in this widespread and phenotypically variable species complex.

  18. Geographic variation in sexual selection and implications for speciation in the Barn Swallow

    Institute of Scientific and Technical Information of China (English)

    Elizabeth; SC; Scordato; Rebecca; J; Safran

    2015-01-01

    Barn Swallows(Hirundo rustica), a group of passerine birds comprised of six closely related subspecies, are well known throughout their nearly worldwide distribution, in part because of their close association with human settlements.A tractable species for both individual-based and population-level studies, Barn Swallows are a prominent model system in evolutionary, ecological, and behavioral research. Here we review work on sexual selection and population divergence in this species complex, focusing on comparative studies among populations and subspecies.We summarize variation in the targets of mate choice and in the information conveyed by sexually selected traits, and conclude that the benefits advertised by different traits may vary geographically. Finally, we consider the role of sexual selection as a driver of population divergence in this widespread and phenotypically variable species complex.

  19. Trends in North American small mammals found in common barn-owl (Tyto alba) dietary studies

    Science.gov (United States)

    Clark, D.R., Jr.; Bunck, C.M.

    1991-01-01

    Data on mammals were compiled from published studies of common barn-owl (Tyto alba) pellets. Mammalian composition of pellet samples was analyzed within geographic regions in regard to year, mean annual precipitation, latitude, and number of individual mammals in the sample. Percentages of individuals in pellets that were shrews increased whereas the percentages of rodents decreased with greater mean annual precipitation, especially in northern and western areas of North America. From the 1920s through 1980s, in northern and eastern areas the percentage of species that was shrews decreased, and in northern and central areas the percentage of individuals that was murid rats and mice increased. Human alterations of habitats during these seven decades are postulated to have caused changes in available small mammals, leading to changes in the barn-owl diet.

  20. Non-planar Feynman integrals, Mellin-Barnes representations, multiple sums

    International Nuclear Information System (INIS)

    The construction of Mellin-Barnes (MB) representations for non-planar Feynman diagrams and the summation of multiple series derived from general MB representations are discussed. A basic version of a new package AMBREv.3.0 is supplemented. The ultimate goal of this project is the automatic evaluation of MB representations for multiloop scalar and tensor Feynman integrals through infinite sums, preferably with analytic solutions. We shortly describe a strategy of further algebraic summation.

  1. Computational Diversity in the Cochlear Nucleus Angularis of the Barn Owl

    OpenAIRE

    Köppl, Christine; Carr, Catherine E.

    2002-01-01

    The cochlear nucleus angularis (NA) is widely assumed to form the starting point of a brain stem pathway for processing sound intensity in birds. Details of its function are unclear, however, and its evolutionary origin and relationship to the mammalian cochlear-nucleus complex are obscure. We have carried out extracellular single-unit recordings in the NA of ketamine-anesthetized barn owls. The aim was to re-evaluate the extent of heterogeneity in NA physiology because recent studies of cell...

  2. Performance and Health of Group-Housed Calves Kept in Igloo Calf Hutches and Calf Barn

    Directory of Open Access Journals (Sweden)

    Jerzy Wójcik*, Renata Pilarczyk, Anna Bilska, Ottfried Weiher1 and Peter Sanftleben1

    2013-04-01

    Full Text Available Group-reared calves are usually housed in common buildings, such as calf barns of all sorts; however, there are concerns about this practice due to problems such as an increased incidence of diseases and poor performance of the calves. Group calf rearing using igloo hutches may be a solution combining the benefits of individual and group housing systems. The aim of this study was to evaluate group-reared calves housed in Igloo-type hutches compared with those housed in common calf barns. The experiment was carried out on a large private dairy farm located in Vorpommern, Germany. A total of 90 Deutsche-Holstein bull calves were assigned to 2 treatment groups: the calf-barn group, with calves grouped in pens in a building, and the Igloo-hutch group, with calves housed in outdoor enclosures with an access to group igloo-style hutches. Calves entering the 84-day experiment were at an average age of about three weeks, with the mean initial body weight of about 50 kg. The calves housed in the group Igloo hutches attained higher daily weight gains compared to those housed in the calf barn (973 vs 721 g/day, consumed more solid feeds (concentrate, corn grain and maize silage: (1.79 vs 1.59 kg/day, and less milk replacer (5.51 vs 6.19 kg/day, had also a lower incidence of respiratory diseases (1.24 vs 3.57% with a shorter persistence of the illness.

  3. Fortellinger om annerledeshet : et studie av barn med funksjonshemninger i Sør-Afrika

    OpenAIRE

    2001-01-01

    I denne oppgaven undersøkes forskjellige lokale oppfatninger, forestillinger og forståelser av "funksjonshemninger". Utgangspunktet er hvordan kvinner og menn konstruerer forestillinger om annerledeshet i lys av oppfatninger om sykdom og lidelser. De sentrale aktørene i fortellingene er familier som har barn med funksjonshemninger i "semi-rurale" landsbyer utenfor byen Pietersburg i den Nordlige Provinsen i Sør-Afrika. Gjennom å følge personene i hverdagsaktiviteter belyses ulike intersubjekt...

  4. A Continent-Wide Migratory Divide in North American Breeding Barn Swallows (Hirundo rustica)

    OpenAIRE

    Keith A. Hobson; Kevin J. Kardynal; Steven L Van Wilgenburg; Gretchen Albrecht; Antonio Salvadori; Cadman, Michael D.; Felix Liechti; Fox, James W.

    2015-01-01

    Populations of most North American aerial insectivores have undergone steep population declines over the past 40 years but the relative importance of factors operating on breeding, wintering, or stopover sites remains unknown. We used archival light-level geolocators to track the phenology, movements and winter locations of barn swallows (Hirdundo rustica; n = 27) from populations across North America to determine their migratory connectivity. We identified an east-west continental migratory ...

  5. Non-planar Feynman integrals, Mellin-Barnes representations, multiple sums

    Energy Technology Data Exchange (ETDEWEB)

    Bluemlein, Johannes; Dubovyk, Ievgen; Ochman, Michal; Raab, Clemens G.; Riemann, Tord [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Gluza, Janusz [Uniwersytet Slaski, Katowice (Poland). Inst. of Physics and Chemistry; Schneider, Carsten [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation

    2014-07-15

    The construction of Mellin-Barnes (MB) representations for non-planar Feynman diagrams and the summation of multiple series derived from general MB representations are discussed. A basic version of a new package AMBREv.3.0 is supplemented. The ultimate goal of this project is the automatic evaluation of MB representations for multiloop scalar and tensor Feynman integrals through infinite sums, preferably with analytic solutions. We shortly describe a strategy of further algebraic summation.

  6. Elever och stress.En undersökning om stress i barns vardag

    OpenAIRE

    Nilsson, Elin

    2003-01-01

    Mitt syfte med det här arbetet är att fokusera på barn och stressen i deras vardag. Jag ville ta reda på vad som orsakar den eventuella stressen och om de har någon metod för att stressa av. Därför har jag intervjuat elever samt gjort en litteraturstudie för att kunna dra paralleller ifrån tidigare forskning.

  7. Mellin-Barnes representations of Feynman diagrams, linear systems of differential equations, and polynomial solutions

    Energy Technology Data Exchange (ETDEWEB)

    Kalmykov, Mikhail Yu.; Kniehl, Bernd A. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2012-05-15

    We argue that the Mellin-Barnes representations of Feynman diagrams can be used for obtaining linear systems of homogeneous differential equations for the original Feynman diagrams with arbitrary powers of propagators without recourse to the integration-by-parts technique. These systems of differential equation can be used (i) for the differential reductions to sets of basic functions and (ii) for counting the numbers of master-integrals.

  8. Photoperiod interacts with food restriction on performance in the Barnes maze in female California mice

    OpenAIRE

    Steinman, Michael Q.; Crean, Katie K.; Trainor, Brian C.

    2010-01-01

    Food restriction has been reported to have positive effects on cognition. This study examines how another environmental factor, daylength, can alter the impact of food restriction on the brain and behavior. Female California mice (Peromyscus californicus), housed on either long days (16L:8D) or short days (8L:16D) were restricted to 80% of their normal baseline food intake or provided food ad libitum. Testing in a Barnes maze revealed that the effects of food restriction depend on photoperiod...

  9. Overt attention toward oriented objects in free-viewing barn owls

    OpenAIRE

    Harmening, Wolf Maximilian; Orlowski, Julius; Ben-Shahar, Ohad; Wagner, Hermann

    2011-01-01

    Visual saliency based on orientation contrast is a perceptual product attributed to the functional organization of the mammalian brain. We examined this visual phenomenon in barn owls by mounting a wireless video microcamera on the owls’ heads and confronting them with visual scenes that contained one differently oriented target among similarly oriented distracters. Without being confined by any particular task, the owls looked significantly longer, more often, and earlier at the target, thus...

  10. Hunting Increases Phosphorylation of Calcium/Calmodulin-Dependent Protein Kinase Type II in Adult Barn Owls

    OpenAIRE

    Nichols, Grant S.; DeBello, William M.

    2015-01-01

    Juvenile barn owls readily adapt to prismatic spectacles, whereas adult owls living under standard aviary conditions do not. We previously demonstrated that phosphorylation of the cyclic-AMP response element-binding protein (CREB) provides a readout of the instructive signals that guide plasticity in juveniles. Here we investigated phosphorylation of calcium/calmodulin-dependent protein kinase II (pCaMKII) in both juveniles and adults. In contrast to CREB, we found no differences in pCaMKII e...

  11. Ring recoveries of dead birds confirm that darker pheomelanic Barn Owls disperse longer distances

    OpenAIRE

    Roulin A.

    2013-01-01

    Variation in melanin coloration is widespread and often associated with other phenotypic traits. A recent study showed that darker-reddish pheomelanic Barn Owls (Tyto alba) move longer distances between birth and breeding sites. Because this study considered only individuals recovered within a limited study area, it remains unclear whether the association between melanism and dispersal applies to a larger geographic scale. I analysed an independent dataset of birds ringed in the same study ar...

  12. Social huddling and physiological thermoregulation are related to melanism in the nocturnal barn owl.

    Science.gov (United States)

    Dreiss, Amélie N; Séchaud, Robin; Béziers, Paul; Villain, Nicolas; Genoud, Michel; Almasi, Bettina; Jenni, Lukas; Roulin, Alexandre

    2016-02-01

    Endothermic animals vary in their physiological ability to maintain a constant body temperature. Since melanin-based coloration is related to thermoregulation and energy homeostasis, we predict that dark and pale melanic individuals adopt different behaviours to regulate their body temperature. Young animals are particularly sensitive to a decrease in ambient temperature because their physiological system is not yet mature and growth may be traded-off against thermoregulation. To reduce energy loss, offspring huddle during periods of cold weather. We investigated in nestling barn owls (Tyto alba) whether body temperature, oxygen consumption and huddling were associated with melanin-based coloration. Isolated owlets displaying more black feather spots had a lower body temperature and consumed more oxygen than those with fewer black spots. This suggests that highly melanic individuals display a different thermoregulation strategy. This interpretation is also supported by the finding that, at relatively low ambient temperature, owlets displaying more black spots huddled more rapidly and more often than those displaying fewer spots. Assuming that spot number is associated with the ability to thermoregulate not only in Swiss barn owls but also in other Tytonidae, our results could explain geographic variation in the degree of melanism. Indeed, in the northern hemisphere, barn owls and allies are less spotted polewards than close to the equator, and in the northern American continent, barn owls are also less spotted in colder regions. If melanic spots themselves helped thermoregulation, we would have expected the opposite results. We therefore suggest that some melanogenic genes pleiotropically regulate thermoregulatory processes. PMID:26552377

  13. Age before beauty? Relationships between fertilization success and age-dependent ornaments in barn swallows

    OpenAIRE

    Lifjeld, Jan T; Kleven, Oddmund; Jacobsen, Frode; McGraw, Kevin J.; Safran, Rebecca J.; Robertson, Raleigh J.

    2011-01-01

    When males become more ornamented and reproduce more successfully as they grow older, phenotypic correlations between ornament exaggeration and reproductive success can be confounded with age effects in cross-sectional studies, and thus say relatively little about sexual selection on these traits. This is exemplified here in a correlative study of male fertilization success in a large colony of American barn swallows (Hirundo rustica erythrogaster). Previous studies of this species have indic...

  14. Darker eumelanic barn owls better withstand food depletion through resistance to food deprivation and lower appetite.

    OpenAIRE

    Dreiss A.; Henry I.; Ruppli C.; Almasi B.; Roulin A.

    2010-01-01

    The intensity of selection exerted on ornaments typically varies between environments. Reaction norms may help to identify the conditions under which ornamented individuals have a selective advantage over drab conspecifics. It has been recently hypothesized that in vertebrates eumelanin-based coloration reflects the ability to regulate the balance between energy intake and expenditure. We tested two predictions of this hypothesis in barn owl nestlings, namely that darker eumelanic individuals...

  15. Numerical integration of massive two-loop Mellin-Barnes integrals in Minkowskian regions

    CERN Document Server

    Dubovyk, Ievgen; Riemann, Tord; Usovitsch, Johann

    2016-01-01

    Mellin-Barnes (MB) techniques applied to integrals emerging in particle physics perturbative calculations are summarized. New versions of AMBRE packages which construct planar and nonplanar MB representations are shortly discussed. The numerical package MBnumerics.m is presented for the first time which is able to calculate with a high precision multidimensional MB integrals in Minkowskian regions. Examples are given for massive vertex integrals which include threshold effects and several scale parameters.

  16. Om å leve med et barn som ikke lenger er i live. En fenomenologisk deskriptiv studie

    Directory of Open Access Journals (Sweden)

    Marte A. Jystad

    2010-08-01

    Full Text Available Artikkelen fokuserer på kunnskap om foreldres opplevelse ved tap av barn og livet etter det. Materialet bygger på intervjuer med foreldre som har mistet barn. Deres beskrivelser ble utgangspunktet for fenomenologisk analyse.Tapet av et barn påvirker alle dimensjoner i livet. Man blir ikke bare konfrontert med selve fraværet av barnet. Man taper også håp og forventninger knyttet til både barnets og ens egen framtid. De eksistensielle spørsmål om måten man forvalter sitt liv på blir nærværende, og søken etter ny mening blir en vedvarende prosess.De ulike foreldre fulgte sin egen veg gjennom sorgprosessen. Likevel er det fellestrekk i opplevelse av vedvarende bånd med barnet, kropp, relasjon til andre, følelse av skyld og mening. Profesjonell hjelp fra helsearbeidere beskrives som avgjørende, spesielt i den første akutte sorgen.

  17. A Continent-Wide Migratory Divide in North American Breeding Barn Swallows (Hirundo rustica.

    Directory of Open Access Journals (Sweden)

    Keith A Hobson

    Full Text Available Populations of most North American aerial insectivores have undergone steep population declines over the past 40 years but the relative importance of factors operating on breeding, wintering, or stopover sites remains unknown. We used archival light-level geolocators to track the phenology, movements and winter locations of barn swallows (Hirdundo rustica; n = 27 from populations across North America to determine their migratory connectivity. We identified an east-west continental migratory divide for barn swallows with birds from western regions (Washington State, USA (n = 8 and Saskatchewan, Canada (n = 5 traveling shorter distances to wintering areas ranging from Oregon to northern Colombia than eastern populations (Ontario (n = 3 and New Brunswick (n = 10, Canada which wintered in South America south of the Amazon basin. A single swallow from a stable population in Alabama shared a similar migration route to eastern barn swallows but wintered farther north in northeast Brazil indicating a potential leap frog pattern migratory among eastern birds. Six of 9 (67% birds from the two eastern populations and Alabama underwent a loop migration west of fall migration routes including around the Gulf of Mexico travelling a mean of 2,224 km and 722 km longer on spring migration, respectively. Longer migration distances, including the requirement to cross the Caribbean Sea and Gulf of Mexico and subsequent shorter sedentary wintering periods, may exacerbate declines for populations breeding in northeastern North America.

  18. Odor characterization from barns and slurry treatment facilities at a commercial swine facility in South Korea

    Science.gov (United States)

    Jo, Sang-Hee; Kim, Ki-Hyun; Jeon, Byong-Hun; Lee, Min-Hee; Kim, Yong-Hyun; Kim, Bo-Won; Cho, Sung-Back; Hwang, Ok-Hwa; Bhattacharya, Satya Sundar

    2015-10-01

    In this study, emission characteristics of major odorants in pig confinement facilities were investigated through comparative analysis between odorant composition and odor intensity. Odorant samples in ambient air were collected from five different paired sampling sites: (1) in- and outside of windowless pig barn, (2) in- and outside of open pig barn, (3) before/after slurry treatment (via liquid fertilization), (4) before/after composting, and (5) two reference background sites on a pig confinement facility. A total of 47 compounds consisting of key offensive odorants (such as reduced sulfur and volatile organic compounds) were measured from each selected site. When the results are compared in terms of odor intensity, a list of odorants (sulfur compounds, volatile fatty acids, phenols, and indoles) were generally seen at enhanced levels on most sites. In two types of pig barn facilities (windowless ('W') and open ('O')), butyric and valeric acid were the predominant species. The removal efficiency of odorants was quite different between the two slurry treatment approaches of composting and liquid fertilization. Although the efficiencies of odor removal in the former were not sufficient, that of the latter was fairly significant in terms of odor intensity. However, some odorants like hydrogen sulfide, methanethiol, p-cresol, and butyric acid were still retained above the odor threshold level. Accordingly, odorant emissions from animal housing facilities can be characterized most effectively by key odorants such as volatile fatty acids and reduced sulfur species.

  19. Calculations on neutron irradiation damage in reactor materials

    International Nuclear Information System (INIS)

    Neutron irradiation damage calculations were made for Mo, Nb, V, Fe, Ni and Cr. Firstly, damage functions were calculated as a function of neutron energy with neutron cross sections of elastic and inelastic scatterings, and (n,2n) and (n,γ) reactions filed in ENDF/B-III. Secondly, displacement damage expressed in displacements per atom (DPA) was estimated for neutron environments such as fission spectrum, thermal neutron reactor (JMTR), fast breeder reactor (MONJU) and two fusion reactors (The Conceptual Design of Fusion Reactor in JAERI and ORNL-Benchmark). then, damage cross section in units of dpa. barn was defined as a factor to convert a given neutron fluence to the DPA value, and was calculated for the materials in the above neutron environments. Finally, production rates of helium and hydrogen atoms were calculated with (n,α) and (n,p) cross sections in ENDF/B-III for the materials irradiated in the above reactors. (auth.)

  20. Visual-auditory integration for visual search: a behavioral study in barn owls

    Directory of Open Access Journals (Sweden)

    Yael eHazan

    2015-02-01

    Full Text Available Barn owls are nocturnal predators that rely on both vision and hearing for survival. The optic tectum of barn owls, a midbrain structure involved in selective attention, has been used as a model for studying visual- auditory integration at the neuronal level. However, behavioral data on visual- auditory integration in barn owls are lacking. The goal of this study was to examine if the integration of visual and auditory signals contributes to the process of guiding attention towards salient stimuli. We attached miniature wireless video cameras on barn owls' heads (OwlCam to track their target of gaze. We first provide evidence that the area centralis (a retinal area with a maximal density of photoreceptors is used as a functional fovea in barn owls. Thus, by mapping the projection of the area centralis on the OwlCam's video frame, it is possible to extract the target of gaze. For the experiment, owls were positioned on a high perch and four food items were scattered in a large arena on the floor. In addition, a hidden loudspeaker was positioned in the arena. The positions of the food items and speaker were changed every session. Video sequences from the OwlCam were saved for offline analysis while the owls spontaneously scanned the room and the food items with abrupt gaze shifts (head saccades. From time to time during the experiment, a brief sound was emitted from the speaker. The fixation points immediately following the sounds were extracted and the distances between the gaze position and the nearest items and loudspeaker were measured. The head saccades were rarely towards the location of the sound source but to salient visual features in the room, such as the door knob or the food items. However, among the food items, the one closest to the loudspeaker had the highest probability of attracting a gaze shift. This result supports the notion that auditory signals are integrated with visual information for the selection of the next visual search

  1. Airborne Microorganisms in Tie-stall Dairy Barns from Brasov County

    Directory of Open Access Journals (Sweden)

    Silvana Popescu

    2011-05-01

    Full Text Available The aim of this study was the assessment of the airborne microorganisms in tie-stall dairy cattle barns, through determination of the total number of bacteria (mesophilic bacteria, staphylococci, streptococci and gram-negative bacteria and fungi. We investigated 8 dairy cattle barns with tie-stalls in Brasov County during the winter of 2009. The mean numbers of bacteria and fungi in the morning and in the evening were: 1.02 °— 105 - 1.26 °— 105 CFU/m3 for mesophilic bacteria, 5.34 °— 104 - 5.91 °— 104 CFU/m3 for staphylococci, 2.93 °— 104 - 3.60 °— 104 CFU/m3 for streptococci, 2.17 °— 103 - 3.48 °— 103 CFU/m3 for gram-negative bacteria and 1.54 °— 104 - 2.75 °— 104 CFU/m3 for fungi. In the investigated cattle houses staphylococci represented 52.35 – 46.90%, streptococci were 28.73 – 28.57%, and the gram-negative bacteria were 2.13 – 2.76% within the overall number of mesophilic bacteria. The numbers of bacteria and fungi were slightly elevated in the evening comparative to the morning, but the differences were statistically insignificant (p>0.05. The great numbers of bacteria and fungi in the air of dairy cattle tie-stall barns indicate an elevated risk of disease for animals and human workers.

  2. Optimization of Apparatus Design and Behavioral Measures for the Assessment of Visuo-Spatial Learning and Memory of Mice on the Barnes Maze

    Science.gov (United States)

    O'Leary, Timothy P.; Brown, Richard E.

    2013-01-01

    We have previously shown that apparatus design can affect visual-spatial cue use and memory performance of mice on the Barnes maze. The present experiment extends these findings by determining the optimal behavioral measures and test procedure for analyzing visuo-spatial learning and memory in three different Barnes maze designs. Male and female…

  3. Barn och ungas önskemål angående den fysiska sjukhusomgivningen : En forskningsöversikt

    OpenAIRE

    Nyberg, Linda

    2016-01-01

    barn och unga blir intagna på sjukhus kan förändringen från den vanliga omgivningen till sjukhusomgivningen bära med sig stor obekantskap och osäkerhet. Det är viktigt att lyssna till barn och ungas egna åsikter om sjukhusomgivningen, eftersom den fysiska omgivningen där man befinner sig påverkar både hälsa och välbefinnande, och borde därmed vara åldersenlig. Samarbetspartnern för examensarbetet är Project LIV, som är en förening som värnar för långtidssjuka barn. Huvudprojektägare Lek, l...

  4. Kan barns empati relateras till hur de tittar när de bedömer ansiktsuttryck?

    OpenAIRE

    Ekstrand, Camilla

    2008-01-01

    Forskning har visat att barn som uppvisar ett normbrytande beteende i kombination med brister i empati och förståelse för ömsesidighet med andra har svårare för att bedöma rädda ansikten än andra barn med normbrytande beteenden. I en studie kopplades detta till att de inte läser av ögonen utan fokuserar mer på munnen. Föreliggande studies huvudsyfte var dels att validera ett instrument för mätning av barns ögonrörelser och relatera ögonrörelser till tolkning av känslor i ansiktsuttryck, dels ...

  5. Yoga i förskolan : En studie om förskolepedagogers upplevelser av yoga bland barn

    OpenAIRE

    Berg, Therese

    2014-01-01

    Barn mår bra av att leka och röra på sig men i dagens samhälle använder man teknisk utrustning i allt större omfattning både inom hemmet och i skolan. Detta medför olika negativa effekter så som koncentrationssvårigheter och övervikt. Undersökningar och studier visar också att barn och unga upplever stress i vardagen på grund av krav från skolan, hemmet och sig själva.   Syftet med denna studie är att undersöka förskolepedagogers upplevelser av yoga bland barn. De som valts ut att delta i stu...

  6. Vad kommer en treåring ihåg? : En studie om svenska barns arbetsminne och fonologi

    OpenAIRE

    Eriksson, Cecilia; Rex, Kristina

    2014-01-01

    Få studier finns om små barns fonologiska förmåga relaterat till arbetsminne. Det råder också en brist på test av arbetsminne för små barn. Föreliggande studie syftade därför till att studera relationen mellan visuellt arbetsminne, fonologiskt arbetsminne och förmåga att hantera fonologiska representationer hos treåringar. Detta har gjorts genom att samla in jämförelsedata för treåringars resultat på det nyutvecklade surfplatte-testet KUBEN (Kognitiv utveckling hos små barn), som testar förmå...

  7. Aktuella teman gällande barn med ADHD och ergoterapeutiska interventioner

    OpenAIRE

    Puotila, Nathalie

    2014-01-01

    Syftet med denna studie var att kartlägga vad aktuell ergoterapeutisk forskning har fo-kuserat på gällande barn med ADHD och ergoterapeutiska åtgärder mellan åren 2008-2013. Forskningsfrågorna delade upp studiens fokus i personrelaterade, miljörelaterade och aktivitetsrelaterade faktorer som ergoterapeuter bör fokusera på enligt forskning. Metoden för arbetet var en systematisk litteraturstudie i form av en forskningsöversikt. Som analysmetod användes en innehållsanalys och som teoretisk refe...

  8. Closely spaced SiGe barns as stressor structures for strain-enhancement in silicon

    Energy Technology Data Exchange (ETDEWEB)

    Hrauda, N.; Zhang, J. J.; Groiss, H.; Etzelstorfer, T.; Stangl, J.; Bauer, G. [Institute of Semiconductor Physics, Johannes Kepler University Linz, Altenbergerstrasse 69, A-4040 Linz (Austria); Gerharz, J. C. [Peter Gruenberg Institut 9 (PGI-9), Forschungszentrum Juelich, D-52425 Juelich (Germany) and JARA-Fundamentals of Future Information Technology, Forschungszentrum Juelich, D-52425 Juelich (Germany); Holy, V. [Faculty of Mathematics and Physics, Charles University Prague, Ke Karlovu 5, 12116 Praha (Czech Republic); Deiter, C.; Seeck, O. H. [Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, D-22607 Hamburg (Germany)

    2013-01-21

    We present tensile and compressive strains realized within the same Si capping layer on an array of SiGe islands grown on pit-patterned (001) Si substrates. The strain distributions are obtained from synchrotron X-ray diffraction studies in combination with three-dimensional finite element calculations and simulations of the diffracted intensities. For barn-shaped islands grown at 720 Degree-Sign C with average Ge contents of 30%, the Si cap layer is misfit- and threading-dislocation free and exhibits compressive strains as high as 0.8% in positions between the islands and tensile strains of up to 1% on top of the islands.

  9. AMBRE - a mathematica package for the construction of Mellin-Barnes representations for Feynman integrals

    Energy Technology Data Exchange (ETDEWEB)

    Gluza, J.; Kajda, K. [Silesia Univ, Katowice (Poland). Dept. of Field Theory and Particle Physics, Inst. of Phsyics; Riemann, T. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2007-05-15

    The Mathematica toolkit AMBRE derives Mellin-Barnes (MB) representations for Feynman integrals in d=4-2{epsilon} dimensions. It may be applied for tadpoles as well as for multi-leg multi-loop scalar and tensor integrals. AMBRE uses a loop-by-loop approach and aims at lowest dimensions of the final MB representations. The present version of AMBRE works fine for planar Feynman diagrams. The output may be further processed by the package MB for the determination of its singularity structure in {epsilon}. The AMBRE package contains various sample applications for Feynman integrals with up to six external particles and up to four loops. (orig.)

  10. Effect of summer grazing on welfare of dairy cows reared in mountain tie-stall barns

    OpenAIRE

    Simonetta Dovier; Edi Piasentier; Mirco Corazzin; Stefano Bovolenta

    2010-01-01

    Traditional mountain farms have an important economic, social and environmental role. The Alps management system for dairy cows consists of animals kept indoors from autumn to spring, mostly in tie-stalls, and moved to mountain pasture in summer. The aim of our study was to assess the effect of mountain summer grazing on the welfare of dairy cows housed in tie-stall barns. Twenty-four farms were considered. In twelve of them, animals were reared in tie-stalls and moved to mountain pasture for...

  11. Problemer med å måle eksponering for passiv røyking blant barn

    Directory of Open Access Journals (Sweden)

    Per Nafstad m.fl.

    2009-10-01

    Full Text Available  SAMMENDRAGVanligvis måles eksponering for passiv røyking blant barn ved spørreskjemaopplysninger omforeldres røykevaner. Etter hvert som det blir mer oppmerksomhet om helseeffekter av passivrøyking, vil det kunne påvirke hvordan foreldre røyker og dermed også barns eksponering. Medhenvisning til innsamlede data om røykeeksponering i en kohort av Oslo-barn og fra en studie avbarn ved to helsestasjoner, diskuteres noen av de metodeproblemene en står overfor når en skal måleeksponering for passiv røyking i epidemiologiske studier. I disse studiene er barns eksponering forpassiv røyking målt ved spørreskjemaopplysninger og ved måling av hårnikotin og kotinin i urin.Det konkluderes med at det er usikkerhet om nøyaktigheten av eksisterende metoder for måling avpassiv røyking. Dette og manglende kunnskap om faktisk eksponeringsnivå kan føre til feilaktigestimering av helseeffekter av passiv røyking i en barnebefolkning.Nafstad P, Botten G, Magnus P. Problems in measuring environmental tobacco smoke exposurein children. Nor J Epidemiol 1995; 5 (2: 141-144.ENGLISH SUMMARYUsually environmental tobacco smoke exposure among children is measuered by questionnaires,recording parental smoking. As the adverse health effects of environmental tobacco smoke exposureare getting more known among the public, this is likely to influence the parents' way of smoking andby that their children's actual exposure. With references to findings in a cohort study of Oslochildren and a study of children attending two of Oslo’s health centers, some methodologicalproblems when measuring environmental tobacco smoke exposure in epidemiological studies arediscussed. The exposure in these studies is measured in questionnaires to the parents and aschildren's hair nicotine concentration and urine cotinine concentration. Furthermore, the paperdiscusses how the uncertainty in actual levels of exposure may lead to false estimates for the totalhealth impact of

  12. Contingency interim measure for the public water supply at Barnes, Kansas.

    Energy Technology Data Exchange (ETDEWEB)

    LaFreniere, L. M.; Environmental Science Division

    2009-07-09

    This document presents a conceptual design for a contingency interim measure (IM) for treatment of the public water supply system at Barnes, Kansas, should this become necessary. The aquifer that serves the public water supply system at Barnes has been affected by trace to low concentrations of carbon tetrachloride and its degradation product, chloroform. Investigations conducted on behalf of the CCC/USDA by Argonne National Laboratory (Argonne 2008a) have demonstrated that groundwater at the Barnes site is contaminated with carbon tetrachloride at concentrations exceeding the Kansas Tier 2 risk-based screening level (RBSL) and the EPA maximum contaminant level (MCL) of 5.0 {micro}g/L for this compound. The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) formerly operated a grain storage facility in Barnes, approximately 800 ft east-southeast of the public water supply wells. Carbon tetrachloride was used in the treatment of grain. Another potential source identified in an investigation conducted for the KDHE (PRC 1996) is the site of a former agriculture building owned by the local school district (USD 223). This building is located immediately east of well PWS3. The potential contingency IM options evaluated in this report include the treatment of groundwater at the public water supply wellheads and the provision of an alternate water supply via Washington County Rural Water District No.2 (RWD 2). This document was developed in accordance with KDHE Bureau of Environmental Remediation (BER) Policy No.BER-RS-029 (Revised) (KDHE 2006a), supplemented by guidance from the KDHE project manager. Upon the approval of this contingency IM conceptual design by the KDHE, the CCC/USDA will prepare a treatment system design document that will contain the following elements: (1) Description of the approved contingency IM treatment method; (2) Drawings and/or schematics provided by the contractor and/or manufacturer of the approved technology; (3) A

  13. Compounding effects on nest-site dispersal of Barn Owls Tyto alba

    DEFF Research Database (Denmark)

    Huffeldt, Nicholas Per; Aggerholm, Iben Næs; Brandtberg, Nathia Hass;

    2012-01-01

    Capsule Recovery distances of Barn Owls ringed as pulli are conditional on ringing date but not on population density. Aims To test whether ring recovery distances (proxy for natal dispersal distances) were conditional on population density and reproductive timing. Methods We used ringing data of...... from 0 to 100 days after ringing, being stable thereafter, and was also impacted by brood size. Owls ringed very early or late in the breeding season were more likely to be recovered < 1 km from the nest-site at a recovery time where dispersal seemed to be completed....

  14. Involutions on the the Barnes-Wall lattices and their fixed point sublattices, I

    OpenAIRE

    Griess Jr., Robert L.

    2005-01-01

    We study the sublattices of the rank $2^d$ Barnes-Wall lattices $\\bw d$ which occur as fixed points of involutions. They have ranks $2^{d-1}$ (for dirty involutions) or $2^{d-1}\\pm 2^{k-1}$ (for clean involutions), where $k$, the defect, is an integer at most $\\frac d 2$. We discuss the involutions on $\\bw d$ and determine the isometry groups of the fixed point sublattices for all involutions of defect 1. Transitivity results for the Bolt-Room-Wall group on isometry types of sublattices exten...

  15. Characterization of Bioaerosols from Dairy Barns: Reconstructing the Puzzle of Occupational Respiratory Diseases by Using Molecular Approaches

    OpenAIRE

    Blais Lecours, Pascale; Veillette, Marc; Marsolais, David; Duchaine, Caroline

    2012-01-01

    To understand the etiology of exposure-related diseases and to establish standards for reducing the risks associated with working in contaminated environments, the exact nature of the bioaerosol components must be defined. Molecular biology tools were used to evaluate airborne bacterial and, for the first time, archaeal content of dairy barns. Three air samplers were tested in each of the 13 barns sampled. Up to 106 archaeal and 108 bacterial 16S rRNA genes per m3 of air were detected. Archae...

  16. Sammenheng mellom drikkevannskvalitet og risiko for Type 1 diabetes blant barn under 16 år i Norge

    OpenAIRE

    Wold, Randi

    2011-01-01

    SAMMENDRAG Mål med studien: Formålet med denne studien er å undersøke assosiasjoner mellom utvalgte vann- kvalitetsvariable i norsk drikkevann og risiko for type 1 diabetes blant barn. Materiale og metode: Dette er en økologisk studie der antall barn under 16 år som har fått diagnosen type 1 diabetes per kommune er responsvariabel, og vannkvalitetsvariabler benyttes som eksponeringsvariable. Insidente tilfeller hentes fra Barnediabetesregisteret, mens de 16 undersøkte variable i ...

  17. Instrumentation strategies for energy conservation in broiler barns with ventilation air solar pre-heaters

    Energy Technology Data Exchange (ETDEWEB)

    Cordeau, Sebastien; Barrington, Suzelle [Department of Bioresource Engineering, Macdonald Campus of McGill University, 21 111 Lakeshore, Ste Anne de Bellevue, Quebec H9X 3V9 (Canada)

    2010-08-15

    At the present consumption rate, world fossil-fuel reserves are expected to be depleted by 2050 unless their consumption is optimized and supplemented with renewable energy sources. The objective of this project was to evaluate the performance of a simple data acquisition system installed to conduct an energy balance and identify energy saving strategies in two commercial broilers barns with ventilation air solar pre-heaters. Located near Montreal, Canada, the two identical barns were instrumented for inside and outside air conditions, ventilation rate and energy recovery by the solar air pre-heaters. Whereas the temperature, relative humidity and radiation sensors were reliable, inside air temperature stratification complicated energy balance analyses and broiler heat production rate calculations. Lack of room air mixing resulted in the loss of 25 and 15% of the generated heater load and recovered solar energy. The proper monitoring of all environmental conditions required their measurement every 5 rather than 20 min. Instead of using a data transmission service found to be unreliable in rural areas, all data loggers were downloaded onto a portable computer every 45 days during regular instrument maintenance. Accordingly, room air mixing is recommended to facilitate energy balance studies and improve the efficient use of heating energies. (author)

  18. Better-surviving barn swallow mothers produce more and better-surviving sons.

    Science.gov (United States)

    Romano, Andrea; Costanzo, Alessandra; Caprioli, Manuela; Parolini, Marco; Ambrosini, Roberto; Rubolini, Diego; Saino, Nicola

    2016-05-01

    Sex allocation theory predicts that parents are selected to bias their progeny sex ratio (SR) toward the sex that will benefit the most from parental quality. Because parental quality may differentially affect survival of sons and daughters, a pivotal test of the adaptive value of SR adjustment is whether parents overproduce offspring of the sex that accrues larger fitness advantages from high parental quality. However, this crucial test of the long-term fitness consequences of sex allocation decisions has seldom been performed. In this study of the barn swallow (Hirundo rustica), we showed a positive correlation between the proportion of sons and maternal annual survival. We then experimentally demonstrated that this association did not depend on the differential costs of rearing offspring of either sex. Finally, we showed that maternal lifespan positively predicted lifespan of sons but not of daughters. Because in barn swallows lifespan is a strong determinant of lifetime reproductive success, the results suggest that mothers overproduce offspring of the sex that benefits the most from maternal quality. Hence, irrespective of mechanisms causing the SR bias and mother-son covariation in lifespan, we provide strong evidence that sex allocation decisions of mothers can highly impact on their lifetime fitness. PMID:26990898

  19. Clock gene polymorphism and scheduling of migration: a geolocator study of the barn swallow Hirundo rustica.

    Science.gov (United States)

    Bazzi, Gaia; Ambrosini, Roberto; Caprioli, Manuela; Costanzo, Alessandra; Liechti, Felix; Gatti, Emanuele; Gianfranceschi, Luca; Podofillini, Stefano; Romano, Andrea; Romano, Maria; Scandolara, Chiara; Saino, Nicola; Rubolini, Diego

    2015-01-01

    Circannual rhythms often rely on endogenous seasonal photoperiodic timers involving 'clock' genes, and Clock gene polymorphism has been associated to variation in phenology in some bird species. In the long-distance migratory barn swallow Hirundo rustica, individuals bearing the rare Clock allele with the largest number of C-terminal polyglutamine repeats found in this species (Q8) show a delayed reproduction and moult later. We explored the association between Clock polymorphism and migration scheduling, as gauged by light-level geolocators, in two barn swallow populations (Switzerland; Po Plain, Italy). Genetic polymorphism was low: 91% of the 64 individuals tracked year-round were Q7/Q7 homozygotes. We compared the phenology of the rare genotypes with the phenotypic distribution of Q7/Q7 homozygotes within each population. In Switzerland, compared to Q7/Q7, two Q6/Q7 males departed earlier from the wintering grounds and arrived earlier to their colony in spring, while a single Q7/Q8 female was delayed for both phenophases. On the other hand, in the Po Plain, three Q6/Q7 individuals had a similar phenology compared to Q7/Q7. The Swiss data are suggestive for a role of genetic polymorphism at a candidate phenological gene in shaping migration traits, and support the idea that Clock polymorphism underlies phenological variation in birds. PMID:26197782

  20. Fitness loss and germline mutations in barn swallows breeding in Chernobyl

    International Nuclear Information System (INIS)

    The severe nuclear accident at Chernobyl in 1986 resulted in the worst reported accidental exposure of radioactive material to free-living organisms. Short-term effects on human populations inhabiting polluted areas include increased incidence of thyroid cancer, infant leukaemia, and congenital malformations in newborns. Two recent studies have reported, although with some controversy, that germline mutation rates were increased in humans and voles living close to Chernobyl, but little is known about the viability of the organisms affected. Here we report an increased frequency of partial albinism, a morphological aberration associated with a loss of fitness, among barn swallows, Hirundo rustica, breeding close to Chernobyl. Heretability estimates indicate that mutations causing albinism were at least partly of germline origin. Furthermore, evidence for an increased germline mutation rate was obtained from segregation analysis at two hypervariable microsatellite loci, indicating that mutation events in barn swallows from Chernobyl were two- to tenfold higher than in birds from control areas in Ukraine and Italy. (author)

  1. Fitness loss and germline mutations in barn swallows breeding in Chernobyl

    Energy Technology Data Exchange (ETDEWEB)

    Ellegren, Hans; Lindgren, Gabriella; Primmer, C.R. [Swedish Univ. of Agricultural Sciences, Animal Breeding and Genetics Dept., Uppsala (Sweden); Moeller, A.P. [Universite Pierre et Marie Curie. Lab. d`Ecologie, Paris, 75 (France)

    1997-10-09

    The severe nuclear accident at Chernobyl in 1986 resulted in the worst reported accidental exposure of radioactive material to free-living organisms. Short-term effects on human populations inhabiting polluted areas include increased incidence of thyroid cancer, infant leukaemia, and congenital malformations in newborns. Two recent studies have reported, although with some controversy, that germline mutation rates were increased in humans and voles living close to Chernobyl, but little is known about the viability of the organisms affected. Here we report an increased frequency of partial albinism, a morphological aberration associated with a loss of fitness, among barn swallows, Hirundo rustica, breeding close to Chernobyl. Heretability estimates indicate that mutations causing albinism were at least partly of germline origin. Furthermore, evidence for an increased germline mutation rate was obtained from segregation analysis at two hypervariable microsatellite loci, indicating that mutation events in barn swallows from Chernobyl were two- to tenfold higher than in birds from control areas in Ukraine and Italy. (author).

  2. POPULATION ECOLOGY AND CONSERVATION OF THE BARN OWL TYTO-ALBA IN FARMLAND HABITATS IN LIEMERS AND ACHTERHOEK (THE NETHERLANDS)

    NARCIS (Netherlands)

    DEBRUIJN, O

    1994-01-01

    Over the last decades, the Barn Owl population has markedly decreased in range and breeding numbers in The Netherlands as in most western European countries. For effective conservation and population management, it is essential to know which factors are responsible for this decline. The present stud

  3. Methane and nitrous oxide analyzer comparison and emissions from dairy freestall barns with manure flushing and scraping

    Science.gov (United States)

    Cortus, Erin L.; Jacobson, Larry D.; Hetchler, Brian P.; Heber, Albert J.; Bogan, Bill W.

    2015-01-01

    Continuous methane (CH4) and nitrous oxide (N2O) emission measurements were conducted at two crossflow-ventilated dairy freestall barns located in the state of Wisconsin, USA during a 19-month period from 2008 to 2010. The two cross-flow mechanically ventilated buildings (275 and 375 cow capacities) were evaluated in the National Air Emissions Monitoring Study. In September of 2008, the barns' manure collection systems were changed from flushing open gutter using manure basin effluent to a tractor scrape. A photoacoustic multi-gas analyzer (PAMGA) and a direct methane/non-methane hydrocarbon analyzer (GC-FID) provided side-by-side measurements of methane (CH4) for 13 months. The PAMGA also measured nitrous oxide (N2O), and a side-by-side comparison was performed with a gas-filter correlation analyzer (GFC) for six months. Barn ventilation rates were measured by recording run times of the 127-cm diameter exhaust fans. All 125 belt-driven exhaust fans were identical, and in situ airflow measurements using the Fan Assessment Numeration System (FANS) were conducted once at the beginning and twice during the test. Daily CH4 and N2O emission rates were calculated over approximately 19 and 6 month periods respectively, on per barn, head, animal unit, floor area space and barn capacity bases. The differences between the analyzers' concentration measurements were compared in conjunction with water vapor and other gases. The analyzer type had a significant impact on the average CH4 emission rate (p GFC were very low, with an approximate rate of only 690 mg AU-1 d-1 (970 mg cow-1 d-1). The change in manure collection had no apparent effect on N2O emission.

  4. N Reactor

    Data.gov (United States)

    Federal Laboratory Consortium — The last of Hanfordqaodmasdkwaspemas7ajkqlsmdqpakldnzsdflss nine plutonium production reactors to be built was the N Reactor.This reactor was called a dual purpose...

  5. Föräldrars erfarenheter av onlinespelande barn : En kvalitativ studie kring problemformuleringar och orsakssamband

    OpenAIRE

    Lundgren, Annelie

    2012-01-01

    Bakgrund: Barn har alltid haft andra förutsättningar än deras föräldrar. En skillnad idag jämfört med tidigare generationer är bland annat tillgång till nya medier för nöje, interaktion och informationssökande. Ett sätt att umgås på, är genom interaktiva onlinespel i en virtuell värld som aldrig tidigare varit möjligt. Detta har i vissa avseenden inneburit att frågor ställts över dess nackdelar i kontrast till den tjusning som onlinespelandet innebär. Syfte: Att beskriva och analysera hur för...

  6. Avian wing geometry and kinematics of a free-flying barn owl in flapping flight

    Science.gov (United States)

    Wolf, Thomas; Konrath, Robert

    2015-02-01

    This paper presents results of high-resolution three-dimensional wing shape measurements performed on free-flying barn owls in flapping flight. The applied measurement technique is introduced together with a moving camera set-up, allowing for an investigation of the free flapping flight of birds with high spatial and temporal resolution. Based on the three-dimensional surface data, a methodology for parameterizing the wing profile along with wing kinematics during flapping flight has been developed. This allowed a description of the spanwise varying kinematics and aerodynamic parameters (e.g. effective angles of attack, camber, thickness) of the wing in dependence on the flapping phase. The results are discussed in detail using the data of a single flight, whereas a comparison of some kinematic parameters obtained from different flights is given too.

  7. Investigation into levels of dioxins, furans and PCBs in battery, free range, barn and organic eggs

    Energy Technology Data Exchange (ETDEWEB)

    Tlustos, C.; Pratt, I. [Food Safety Authority of Ireland, Dublin (Ireland); Moylan, R.; Neilan, R. [Dept. of Agriculture and Food, Maynooth (Ireland); White, S.; Fernandes, A.; Rose, M. [Central Science Lab., York (United Kingdom)

    2004-09-15

    The Food Safety Authority of Ireland (FSAI) has a statutory responsibility to assure the safety of food consumed, distributed, produced and sold on the Irish market. The results of a targeted surveillance study on levels of dioxins, furans and polychlorinated biphenyls (PCBs) in battery, free-range, barn and organic eggs are presented here. The study was undertaken against the background of increased awareness in the European Union of the possible health risks posed by dioxins, furans and polychlorinated biphenyls (PCBs) in the food chain, and builds on previous studies undertaken by FSAI into levels of these contaminants in milk, fish and fish oils. The opportunity was taken at the same time to investigate the levels of a number of metals in these eggs, and results of the full study are available on the FSAI website.

  8. Ferrofluid Simulations with the Barnes-Hut Algorithm on Graphics Processing Units

    CERN Document Server

    Polyakov, A Yu; Denisov, S; Reva, V V; Hanggi, P

    2012-01-01

    We present an approach to molecular-dynamics simulations of dilute ferrofluids on graphics processing units (GPUs). Our numerical scheme is based on a GPU-oriented modification of the Barnes-Hut (BH) algorithm designed to increase the parallelism of computations. For an ensemble consisting of one million of ferromagnetic particles, the performance of the proposed algorithm on a Tesla M2050 GPU demonstrated a computational-time speed-up of four order of magnitude compared to the performance of the sequential All-Pairs (AP) algorithm on a single-core CPU, and two order of magnitude compared to the performance of the optimized AP algorithm on the GPU. The accuracy of the scheme is corroborated by comparing theoretical predictions with the results of numerical simulations.

  9. Prey selection by the Barn Owl Tyto alba (Scopoli, 1769 in captivity

    Directory of Open Access Journals (Sweden)

    V. Vanitha

    2009-07-01

    Full Text Available We investigated prey selection of the Barn Owl Tyto alba under captive conditions where birds were allowed to choose among individuals of varying size from four field rodent species: Bandicota bengalensis, Millardia meltada, Tatera indica and Mus booduga. Owls showed little species preference and a tendency to favour the medium weight class in all prey species except M. booduga. Preference for body parts consumed varied according to prey size, ranging from the head alone in the large weight class to the entire body in the small weight class. Biochemical measurements showed that protein, carbohydrate and lipid levels were higher respectively in the brain, liver and muscles of all three species and weight classes studied. The preference for medium weight prey despite a lower nutrient content compared to large weight prey is attributed to a greater ease of capture.

  10. Independence of echo-threshold and echo-delay in the barn owl.

    Directory of Open Access Journals (Sweden)

    Brian S Nelson

    Full Text Available Despite their prevalence in nature, echoes are not perceived as events separate from the sounds arriving directly from an active source, until the echo's delay is long. We measured the head-saccades of barn owls and the responses of neurons in their auditory space-maps while presenting a long duration noise-burst and a simulated echo. Under this paradigm, there were two possible stimulus segments that could potentially signal the location of the echo. One was at the onset of the echo; the other, after the offset of the direct (leading sound, when only the echo was present. By lengthening the echo's duration, independently of its delay, spikes and saccades were evoked by the source of the echo even at delays that normally evoked saccades to only the direct source. An echo's location thus appears to be signaled by the neural response evoked after the offset of the direct sound.

  11. Characterization of Prototheca zopfii Genotypes Isolated from Cases of Bovine Mastitis and Cow Barns in China.

    Science.gov (United States)

    Shahid, Muhammad; Ali, Tariq; Zhang, Limei; Hou, Rongguang; Zhang, Shiyao; Ding, Laidi; Han, Dandan; Deng, Zhaoju; Rahman, Abdur; Han, Bo

    2016-04-01

    Protothecal mastitis, caused mostly by Prototheca zopfii (P. zopfii), is increasing in dairy herds and is being reported globally. The present study was aimed at studying the epidemiology of mastitis and at molecular characterization of P. zopfii isolates from dairy herds and their surroundings in three provinces of China using microbiological, biochemical and molecular methods, and antibiotic susceptibility tests. Samples from milk (n = 620) of mastitic cows and their barns sources (n = 410) including feces, feed, bedding materials and drinking water were analyzed. Among other pathogens recovered from mastitic milk, 84 (13.5 %) of the isolates were identified as P. zopfii. All of the P. zopfii isolates recovered from milk were recognized as genotype 2, whereas 58 (73.4 %) and 21 (26.6 %) isolates from environmental sources were found to be P. zopfii genotypes 1 and 2, respectively. The isolates were susceptible to some antibiotics and antifungal agents, including amikacin (78.1 %), streptomycin (58.5 %), gentamicin (17.8 %), amphotericin B (68.6 %) and nystatin (64.4 %). Additionally, the two genotypes displayed versatile patterns of susceptibility to different antimicrobials agents. Phylogeny of the genotypes on the basis of 18S SSU rDNA and 28S SSU rDNA was also investigated. The isolates of the two genotypes separated into different clades, and no interrelationship was observed among these as shown by phylogenetic analysis. The genotype 1 isolates from cow barn sources were non-pathogenic and may not present any risk of mastitis. We conclude that P. zopfii genotype 2 might play an important role in bovine mastitis in China. PMID:26450620

  12. Hematologic and plasma biochemistry reference intervals of healthy adult barn owls (Tyto alba).

    Science.gov (United States)

    Szabo, Zoltan; Klein, Akos; Jakab, Csaba

    2014-06-01

    Hematologic and plasma biochemistry parameters of barn owls (Tyto alba) were studied in collaboration by the Exotic Division of the Faculty of Veterinary Science of the Szent Istvan University and the Eötvös Loránd University, both in Budapest, Hungary. Blood samples were taken from a total of 42 adult barn owls kept in zoos and bird repatriation stations. The following quantitative and qualitative hematologic values were determined: packed cell volume, 46.2 +/- 4%; hemoglobin concentration, 107 +/- 15 g/L; red blood cell count, 3.2 +/- 0.4 x 10(12)/L; white blood cell count, 13.7 +/- 2.7 x 10(9)/L; heterophils, 56.5 +/- 11.5% (7.8 +/- 2 x 10(9)/L); lymphocytes, 40.3 +/- 10.9% (5.5 +/- 1.9 x 10(9)/L); monocytes, 1.8 +/- 2.1% (0.3 +/- 0.3 x 10(9)/ L); eosinophils, 1 +/- 1% (0.1 +/- 0.1 x 10(9)/L); and basophils, 0.6 +/- 0.5% (0.1 +/- 0.1 x 10(9)/L). The following plasma biochemistry values also were determined: aspartate aminotransferase, 272 +/- 43 U/L; L-gamma-glutamyltransferase, 9.5 +/- 4.7 U/L; lipase, 31.7 +/- 11.1 U/L; creatine kinase, 2228 +/- 578 U/L; lactate dehydrogenase, 1702 +/- 475 U/L; alkaline phosphatase, 358 +/- 197 U/L; amylase, 563 +/- 114 U/L; glutamate dehydrogenase, 7.5 +/- 2.5 U/L; total protein, 30.6 +/- 5.3 g/L; uric acid, 428 +/- 102 micromol/L; and bile acids, 43 +/- 18 micromol/L. These results provide reliable reference values for the clinical interpretation of hematologic and plasma biochemistry results for the species. PMID:25055626

  13. Vi trenger longitudinelle epidemiologiske undersøkelser av psykiske lidelser og utviklingsforstyrrelser hos barn

    Directory of Open Access Journals (Sweden)

    Bente Gjærum

    2009-10-01

    Full Text Available  sAMMENDRAGArtikkelen gjennomgår nyere forekomststudier for utviklings- og atferdsforstyrrelser, nevrologiske og psykiskelidelser hos barn og ungdom. Forfatterne peker på den betydelige komorbiditet som sees for disse grupperav tilstander, og den tverrfaglige bredde som synes nødvendig for å forstå hvilke faktorer og mekanismer sompåvirker barns utvikling og psykiske helse. I tillegg refereres nyere forskning på forløp og varighet vedavvikende utvikling i oppveksten, samt eksempler på undersøkelser av beskyttelsesfaktorer såvel som genetiskefaktorer av betydning for å forstå de typer tilstander som her er fokusert. Til slutt nevnes de muligheteneulike typer prospektiv, epidemiologisk forskning i et utviklingsperspektiv vil gi til en bedret forståelse avårsaks- og utviklingsforhold, samt forløp og prognose for disse tilstandene. Slik kunnskap antas å ville gibedre muligheter til samfunnsmessig planlegging av forebyggende arbeid og individuell behandling.Gjærum B, Nøvik TS. There is a need for longitudinal studies of psychiatric and developmentaldisorders in children.   ENGLISH SUMMARYThis article reviews recent prevalence studies of developmental and behavioural disorders, and neurologicaland psychiatric disorders in children and adolescents. The authors highlight the degree of comorbidity amongthese conditions and emphasize the complexity of models that should be used in order to understand howdifferent factors and mechanisms affect children's development and mental health. Further, studies of courseand duration of deviant development in childhood, studies of protective factors and contributions frombehavioural genetic studies to the understanding of these conditions, are addressed. Finally, the authorsdiscuss the possibility of using prospective, epidemiological studies in a developmental perspective in order tounderstand etiological and developmental factors, course and prognosis. Such knowledge would lay thefoundations

  14. Population and colony-level determinants of tertiary sex ratio in the declining barn swallow.

    Directory of Open Access Journals (Sweden)

    Nicola Saino

    Full Text Available Sex ratio of adults (tertiary sex ratio, TSR is a major feature of animal populations with consequences for their behaviour, genetic structure and viability. Spatial and temporal variation in TSR occurs within species but the mechanisms behind it are poorly understood. In this long-term study of a declining population of a socially monogamous, colonial, migratory bird, the barn swallow (Hirundo rustica, we first analyzed population-level variation in TSR ( =  proportion of males of yearlings at sexual maturation in relation to ecological conditions as gauged by annual survival rate of adults. TSR was male-biased both among yearlings and older individuals, but male bias of yearlings was more pronounced after years with larger decline in adult survival. Thus, male offspring were less susceptible to the adverse ecological conditions that cause increased mortality. Dispersal and settling site decisions can have major consequences on fitness via the effects of local TSR on mating and sperm competition. Breeding barn swallows are highly philopatric while natal dispersal is high and, together with mortality, is the main determinant of colony TSR. We thus also investigated the mechanisms of breeding colony choice by yearlings and found that TSR of new-settlers in a given colony and year was negatively predicted by TSR of returning, early arriving older individuals in that year, but not by overall TSR at the colony in the previous year. This suggests that in our male-biased population new-settler males respond to local TSR upon arrival to choose the sites with larger breeding opportunities. Hence, variation in ecological conditions as reflected by adult survival can shift the TSR of individuals recruiting into a local population, with potentially various demographic consequences. However, breeding site choice based on TSR tends to homogenize TSR at a population level likely by facilitating settling of dispersing males in colonies with less male

  15. Viability is associated with melanin-based coloration in the barn swallow (Hirundo rustica.

    Directory of Open Access Journals (Sweden)

    Nicola Saino

    Full Text Available Pigmentation of body surface in animals can have multiple determinants and accomplish diverse functions. Eumelanin and pheomelanin are the main animal pigments, being responsible of yellow, brownish-red and black hues, and have partly common biosynthetic pathways. Many populations of vertebrates show individual variation in melanism, putatively with large heritable component. Genes responsible for eu- or pheomelanogenesis have pleiotropic but contrasting effects on life-history traits, explaining the patterns of covariation observed between melanization and physiology (e.g. immunity and stress response, sexual behavior and other characters in diverse taxa. Yet, very few studies in the wild have investigated if eu- and pheomelanization predict major fitness traits like viability or fecundity. In this correlative study, by contrasting adult barn swallows (Hirundo rustica matched for age, sex, breeding site, and year and date of sampling, we show that males but not females that survived until the next year had paler, relatively more eu- than pheomelanic pigmentation of ventral body feathers. Better performance of individuals that allocate relatively more to eumelanogenesis was expected based on previous evidence on covariation between eumelanic pigmentation and specific traits related to immunity and susceptibility to stress. However, together with the evidence of no covariation between viability and melanization among females, this finding raises the question of the mechanisms that maintain variation in genes for melanogenesis. We discuss the possibility that eu- and pheomelanization are under contrasting viability and sexual selection, as suggested by larger breeding and sperm competition success of darker males from other barn swallow subspecies.

  16. Distriktssköterskornas upplevelser av möten med våldutsatta kvinnor och deras barn : En deskriptiv kvalitativ intervjustudie

    OpenAIRE

    Lobanova, Olga

    2012-01-01

    Bakgrund: Distriktssköterskor på BVC möter ibland våldutsatta kvinnor och deras barn i sitt arbete. Följder av våld i nära relationer kan vara försämrad psykosocial hälsa både hos kvinnor och barn. Att tidigt upptäcka och hjälpa en sådan kvinna och hennes barn är ett viktigt uppdrag som distriktssköterskan har på BVC. Syftet med studien var att undersöka distriktssköterskornas upplevelser av möten med våldutsatta kvinnor och deras barn på BVC samt ta reda på vad som saknas kunskaps- och metod...

  17. Starch gel and cellulose acetate electrophoretic analysis of allozyme frequencies in barn swallow (Hirundo rustica) populations at a dioxin contaminated site in northern Louisiana

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This study compared the genetic variability of Louisiana barn swallows at a dioxin-contaminated wetland to two reference populations. Allozyme frequencies,...

  18. Tillfälliga föräldrar : - En studie om familjehemsföräldrars resonemang kring placerade barns anknytning

    OpenAIRE

    Hart, Sara; Crnoja, Monika

    2014-01-01

    Studien har syftat till att få en förståelse för familjehemsföräldrars perspektiv på anknytning och vad de menar att det finns för svårigheter och möjligheter gällande anknytning för barn som placeras i familjehem. Studien berör även hur relationen mellan barn och familjehemsförälder förändras över tid och hur samspel mellan barn och familjehemsföräldrar, barn och de biologiska föräldrarna och barnets tidigare erfarenheter kan påverka anknytningen. Studien är kvalitativ och bygger på intervju...

  19. Miljöutbildande spel : förslag till nytt spel för barn 6-8 år Gro Play AB

    OpenAIRE

    Mirzaei Langroodi, Negar

    2011-01-01

    Kan barn leka sig till en miljövänligare livsstil? Svaret är ja, om du frågar Patricia Rawecka, vd på företaget Gro Play AB. Hon har själv designat och utvecklat tre pussel för barn i åldrarna 3-5 år som både är miljövänliga och miljöutbildande. Med tanke på dagens extrema konsumtionskultur ville hon med god design, pedagogik och via barns lek motivera nästkommande generation till en mer hållbar livsstil. Visionen för hennes företag och även för detta examensarbete har varit att ge barn en ch...

  20. Morphometric characterisation of wing feathers of the barn owl Tyto alba pratincola and the pigeon Columba livia

    Directory of Open Access Journals (Sweden)

    Klaas Michael

    2007-11-01

    Full Text Available Abstract Background Owls are known for their silent flight. Even though there is some information available on the mechanisms that lead to a reduction of noise emission, neither the morphological basis, nor the biological mechanisms of the owl's silent flight are known. Therefore, we have initiated a systematic analysis of wing morphology in both a specialist, the barn owl, and a generalist, the pigeon. This report presents a comparison between the feathers of the barn owl and the pigeon and emphasise the specific characteristics of the owl's feathers on macroscopic and microscopic level. An understanding of the features and mechanisms underlying this silent flight might eventually be employed for aerodynamic purposes and lead to a new wing design in modern aircrafts. Results A variety of different feathers (six remiges and six coverts, taken from several specimen in either species, were investigated. Quantitative analysis of digital images and scanning electron microscopy were used for a morphometric characterisation. Although both species have comparable body weights, barn owl feathers were in general larger than pigeon feathers. For both species, the depth and the area of the outer vanes of the remiges were typically smaller than those of the inner vanes. This difference was more pronounced in the barn owl than in the pigeon. Owl feathers also had lesser radiates, longer pennula, and were more translucent than pigeon feathers. The two species achieved smooth edges and regular surfaces of the vanes by different construction principles: while the angles of attachment to the rachis and the length of the barbs was nearly constant for the barn owl, these parameters varied in the pigeon. We also present a quantitative description of several characteristic features of barn owl feathers, e.g., the serrations at the leading edge of the wing, the fringes at the edges of each feather, and the velvet-like dorsal surface. Conclusion The quantitative

  1. Specialpedagogiska metoder som främjar utvecklingen hos barn med autism samt hur dessa påverkar barn och föräldra-/vårdarrelation-en litteraturstudie

    OpenAIRE

    Solvarm, Rosemary

    2008-01-01

    Autism är ett livslångt handikapp som ställer stora krav på familj, skola, sjukvård samt övriga personer som på olika sätt kommer i kontakt med dessa barn. Pedagoger och vårdare behöver medvetandegöras om sina föreställningar eftersom dessa styr bemötandet. Målet för behandlingen är målmedveten träning eftersom förmåga till social inlevelseförmåga mer eller mindre saknas hos såväl barn som vuxna med autism. Syftet med litteraturstudien var att belysa metoder som fanns för att främja utvecklin...

  2. Sambandet mellan övervikt/fetma och orala sjukdomar hos barn och ungdomar : En litteraturöversikt

    OpenAIRE

    Khanbhai, Rashida; Hanna, Nareeman

    2015-01-01

    Bakgrund: Övervikt/fetma är ett hälsoproblem som snabbt ökar i Sverige och hela världen. Övervikt/fetma, karies och parodontit är alla kroniska och multifaktoriella sjukdomar. Dessa sjukdomar är vanligt förekommande hos både barn och ungdomar. De orala sjukdomarna är förknippade med ohälsosamma kostvanor som påverkar både orala- och allmänna hälsan och som i sin tur kan påverka vikten hos barn och ungdomar. Syfte: Att studera om det finns ett eventuellt samband mellan övervikt/fetma och orala...

  3. Ambulanssjuksköterskors upplevelser av smärtlindring av barn i en prehospital kontext - en kvalitativ intervjustudie

    OpenAIRE

    Ekstrand, Magnus; Hed, Kristina

    2014-01-01

    Syftet med denna studie är att studera ambulanssjuksköterskors upplevelser av att bedöma och vårda barn under tio års ålder med akut smärta i en prehospital kontext.   Metod: Studien utfördes som en kvalitativ empirisk intervjustudie baserad på fem öppna frågor. Tio ambulanssjuksköterskor intervjuades och fick beskriva positiva och negativa upplevelser av att omhänderta barn 0-10 år med akut smärta i prehospital kontext. Materialet analyserades genom en kvalitativ innehållsanalys med en manif...

  4. Att hjälpa barn i kris : En litteraturöversikt om krisarbete på daghem

    OpenAIRE

    Backman, Sofia

    2011-01-01

    Detta examensarbete handlar om barn i kris och krisberedskap på daghem. Syftet är att utgående från litteratur och forskningar ta reda på hur personal på daghem kan stöda barn som utsatts för en krissituation, samt hur en bra beredskapsplan kan se ut för att personalen på daghemmen ska få en bra grund att utgå från. Utgående från arbetets syfte har två forskningsfrågor formulerats: vad ska en bra beredskapsplan innehålla och hur kan man förbereda sig inför en eventuell krissituation? Hur stöd...

  5. Reactor Physics

    International Nuclear Information System (INIS)

    The Reactor Physics and MYRRHA Department of SCK-CEN offers expertise in various areas of reactor physics, in particular in neutronics calculations, reactor dosimetry, reactor operation, reactor safety and control and non-destructive analysis of reactor fuel. This expertise is applied in the Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 reactor dosimetry, and the preparation and interpretation of irradiation experiments by means of neutron and gamma calculations. The activities of the Fuzzy Logic and Intelligent Technologies in Nuclear Science programme cover several domains outside the department. Progress and achievements in these topical areas in 2000 are summarised

  6. Reactor Physics

    International Nuclear Information System (INIS)

    SCK-CEN's Reactor Physics and MYRRHA Department offers expertise in various areas of reactor physics, in particular in neutron and gamma calculations, reactor dosimetry, reactor operation and control, reactor code benchmarking and reactor safety calculations. This expertise is applied in the Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 materials testing reactor dosimetry, and the preparation and interpretation of irradiation experiments by means of neutron and gamma calculations. The activities of the Fuzzy Logic and Intelligent Technologies in Nuclear Science programme cover several domains outside the department. Progress and achievements in these topical areas in 2001 are summarised

  7. Reactor Physics

    Energy Technology Data Exchange (ETDEWEB)

    Ait Abderrahim, A

    2001-04-01

    The Reactor Physics and MYRRHA Department of SCK-CEN offers expertise in various areas of reactor physics, in particular in neutronics calculations, reactor dosimetry, reactor operation, reactor safety and control and non-destructive analysis of reactor fuel. This expertise is applied in the Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 reactor dosimetry, and the preparation and interpretation of irradiation experiments by means of neutron and gamma calculations. The activities of the Fuzzy Logic and Intelligent Technologies in Nuclear Science programme cover several domains outside the department. Progress and achievements in these topical areas in 2000 are summarised.

  8. Sex-related effects of an immune challenge on growth and begging behavior of barn swallow nestlings

    OpenAIRE

    Andrea Romano; Diego Rubolini; Manuela Caprioli; Giuseppe Boncoraglio; Roberto Ambrosini; Nicola Saino

    2011-01-01

    Parent-offspring conflicts lead the offspring to evolve reliable signals of individual quality, including parasite burden, which may allow parents to adaptively modulate investment in the progeny. Sex-related variation in offspring reproductive value, however, may entail differential investment in sons and daughters. Here, we experimentally manipulated offspring condition in the barn swallow (Hirundo rustica) by subjecting nestlings to an immune challenge (injection with bacterial lipopolysac...

  9. Individual vocal signatures in barn owl nestlings: does individual recognition have an adaptive role in sibling vocal competition?

    OpenAIRE

    Dreiss A.N.; Ruppli C.A.; Roulin A.

    2014-01-01

    To compete over limited parental resources, young animals communicate with their parents and siblings by producing honest vocal signals of need. Components of begging calls that are sensitive to food deprivation may honestly signal need, whereas other components may be associated with individual-specific attributes that do not change with time such as identity, sex, absolute age and hierarchy. In a sib-sib communication system where barn owl (Tyto alba) nestlings vocally negotiate priority ac...

  10. Pegasta sova Tyto alba v JV delu Prekmurja: Barn owl Tyto alba in the SE part of Prekmurje (NE Slovenia):

    OpenAIRE

    Katalinič, Dane

    2000-01-01

    During 1995-1999, three localities where regular presence of Barn Owls was established were discovered in the SE part of Prekmurje covering some 225 km2.The owls inhabit the abandoned state cowsheds. V JV delu Prekmurja so bile na območju, velikem 225 km2, med letoma 1995 in 1999 najdene tri lokalitete, kjer je bilo ugotovljeno redno pojavljanj pegastih sov. Sove naseljujejo zapuščene družbene hleve.

  11. Early blindness results in a degraded auditory map of space in the optic tectum of the barn owl.

    OpenAIRE

    Knudsen, E I

    1988-01-01

    The optic tectum of the barn owl (Tyto alba) contains a neural map of auditory space consisting of neurons that are sharply tuned for sound source location and organized precisely according to their spatial tuning. The importance of vision for the development of this auditory map was investigated by comparing space maps measured in normal owls with those measured in owls raised with both eyelids sutured closed. The results demonstrate that owls raised without sight, but with normal hearing, d...

  12. Reactor operation

    CERN Document Server

    Shaw, J

    2013-01-01

    Reactor Operation covers the theoretical aspects and design information of nuclear reactors. This book is composed of nine chapters that also consider their control, calibration, and experimentation.The opening chapters present the general problems of reactor operation and the principles of reactor control and operation. The succeeding chapters deal with the instrumentation, start-up, pre-commissioning, and physical experiments of nuclear reactors. The remaining chapters are devoted to the control rod calibrations and temperature coefficient measurements in the reactor. These chapters also exp

  13. Reactor safeguards

    CERN Document Server

    Russell, Charles R

    2013-01-01

    Reactor Safeguards provides information for all who are interested in the subject of reactor safeguards. Much of the material is descriptive although some sections are written for the engineer or physicist directly concerned with hazards analysis or site selection problems. The book opens with an introductory chapter on radiation hazards, the construction of nuclear reactors, safety issues, and the operation of nuclear reactors. This is followed by separate chapters that discuss radioactive materials, reactor kinetics, control and safety systems, containment, safety features for water reactor

  14. Evolutionary divergence in sexual signals: Insights from within and among barn swallow populations

    Science.gov (United States)

    Wilkins, Matthew Reed

    A wealth of studies across diverse animal groups indicate the importance of sexual selection in shaping phenotypes within and across breeding populations. In recent decades, much research has focused on how divergent sexual selection pressures among populations may lead to speciation. For my first dissertation chapter, I performed a literature review on the causes and consequences of evolutionary divergence in acoustic signals and developed the acoustic window conceptual framework for understanding the contributions of selection, genetic drift, and evolutionary constraint to signal divergence. Further, I found that sexual selection explains acoustic differences between recently diverged populations of the best-studied taxa. However, the relative contributions of ecological selection, sexual selection, and drift to acoustic divergence have not typically been considered within the same study systems. The remainder of my dissertation used the Northern Hemisphere-distributed barn swallow ( Hirundo rustica) species complex as a model system to study sender-receiver dynamics, intra- and intersexual selection pressures, and visual and acoustic signal interactions at the local scale, and signal divergence across populations at the global scale. From song recordings taken across 19 sampling sites, spanning five of six described subspecies, I demonstrated considerable conservation in song structure. However, temporal traits were highly divergent across subspecies, and in particular, the speed of the terminal trill of songs. In a detailed study of the multimodal communication system of the barn swallow (including visual and acoustic traits), I demonstrated that males and females use different types of signals to mediate competition and mate choice. One of the only exceptions to this rule was trill rate, which was also implicated in song divergence across populations. In order to test the function of trill rate in communication, I performed a two-year playback study within the

  15. Research Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Martens, Frederick H. [Argonne National Laboratory; Jacobson, Norman H.

    1968-09-01

    This booklet discusses research reactors - reactors designed to provide a source of neutrons and/or gamma radiation for research, or to aid in the investigation of the effects of radiation on any type of material.

  16. Solution to Bethe-Salpeter equation via Mellin-Barnes transform

    Energy Technology Data Exchange (ETDEWEB)

    Allendes, Pedro [Concepcion Univ. (Chile). Dept. de Fisica; Kniehl, Bernd [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Kondrashuk, Igor; Rojas Medar, Marko [Univ. del Bio-Bio, Chillan (Chile). Dept. de Ciencias Basicas; Notte Cuello, Eduardo A. [Univ. de La Serena (Chile). Facultad de Ciencias

    2012-06-15

    We consider Mellin-Barnes transform of triangle ladder-like scalar diagram in d=4 dimensions. It is shown how multi-fold MB transform of the momentum integral corresponding to any number of rungs is reduced to two-fold MB transform. For this purpose we use Belokurov-Usyukina reduction method for four-dimensional scalar integrals in the position space. The result is represented in terms of Euler {psi}-function and its derivatives. We derive new formulas for MB two-fold integration in the complex planes of two complex variables. We demonstrate that these formulas solve Bethe-Salpeter equation. We comment on further applications of solution to Bethe-Salpeter equation for vertices in N=4 supersymmetric Yang-Mills theory. We show that the recursive property of MB transforms observed in the present work for that kind of diagrams has nothing to do with quantum field theory, theory of integral transforms, or with theory of polylogarithms in general, but has an origin in a simple recursive property for smooth functions which can be shown by using basic methods of mathematical analysis.

  17. Two-fold Mellin-Barnes transforms of Usyukina-Davydychev functions

    Energy Technology Data Exchange (ETDEWEB)

    Kniehl, Bernd [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Kondrashuk, Igor [Univ. del Bio Bio, Chillan (Chile). Dept. de Ciencias Basicas; Bielefeld Univ. (Germany). Fakultaet fuer Physik; Notte-Cuello, Eduardo A. [Univ. de La Serena (Chile). Dept. de Matematicas; Parra-Ferrada, Ivan [Univ. del Bio Bio, Chillan (Chile). Facultad de Educacion y Humanidades; Rojas-Medar, Marko [Univ. del Bio Bio, Chillan (Chile). Dept. de Ciencias Basicas

    2013-04-15

    In our previous paper (Nucl.Phys.B 870 (2013) 243) we showed that multi-fold Mellin-Barnes (MB) transforms of the Usyukina-Davydychev (UD) functions may be reduced to two-fold MB transforms. The MB transforms were written there as polynomials of logarithms of ratios of squares of the external momenta with certain coefficients. We also showed that these coefficients have a combinatoric origin. In this paper we present an explicit formula for these coefficients. The procedure of recovering the coefficients is based on taking the double uni-form limit in certain series of smooth functions of two variables which is constructed according to a pre-determined iterative way. The result is obtained by using basic methods of mathematical analysis. We observe that the finiteness of the limit of this iterative chain of smooth functions should reflect itself in other mathematical constructions, too, since it is not related in any way to the explicit form of the MB transforms.

  18. Two-fold Mellin–Barnes transforms of Usyukina–Davydychev functions

    International Nuclear Information System (INIS)

    In our previous paper (Allendes et al., 2013 [10]), we showed that multi-fold Mellin–Barnes (MB) transforms of Usyukina–Davydychev (UD) functions may be reduced to two-fold MB transforms. The MB transforms were written there as polynomials of logarithms of ratios of squares of the external momenta with certain coefficients. We also showed that these coefficients have a combinatoric origin. In this paper, we present an explicit formula for these coefficients. The procedure of recovering the coefficients is based on taking the double-uniform limit in certain series of smooth functions of two variables which is constructed according to a pre-determined iterative way. The result is obtained by using basic methods of mathematical analysis. We observe that the finiteness of the limit of this iterative chain of smooth functions should reflect itself in other mathematical constructions, too, since it is not related in any way to the explicit form of the MB transforms. This finite double-uniform limit is represented in terms of a differential operator with respect to an auxiliary parameter which acts on the integrand of a certain two-fold MB integral. To demonstrate that our result is compatible with original representations of UD functions, we reproduce the integrands of these original integral representations by applying this differential operator to the integrand of the simple integral representation of the scalar triangle four-dimensional integral J(1,1,1−ε)

  19. Two-fold Mellin–Barnes transforms of Usyukina–Davydychev functions

    Energy Technology Data Exchange (ETDEWEB)

    Kniehl, Bernd A., E-mail: kniehl@desy.de [II. Institut für Theoretische Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); Kondrashuk, Igor [Grupo de Matemática Aplicada, Departamento de Ciencias Básicas, Universidad del Bío-Bío, Campus Fernando May, Casilla 447, Chillán (Chile); Fakultät für Physik, Universität Bielefeld, Universitätsstraße 25, 33615 Bielefeld (Germany); Notte-Cuello, Eduardo A. [Departamento de Matemáticas, Facultad de Ciencias, Universidad de La Serena, Av. Cisternas 1200, La Serena (Chile); Parra-Ferrada, Ivan [Carrera de Pedagogia en Matemática, Facultad de Educación y Humanidades, Universidad del Bío-Bío, Campus Castilla, Casilla 447, Chillán (Chile); Rojas-Medar, Marko [Grupo de Matemática Aplicada, Departamento de Ciencias Básicas, Universidad del Bío-Bío, Campus Fernando May, Casilla 447, Chillán (Chile)

    2013-11-01

    In our previous paper (Allendes et al., 2013 [10]), we showed that multi-fold Mellin–Barnes (MB) transforms of Usyukina–Davydychev (UD) functions may be reduced to two-fold MB transforms. The MB transforms were written there as polynomials of logarithms of ratios of squares of the external momenta with certain coefficients. We also showed that these coefficients have a combinatoric origin. In this paper, we present an explicit formula for these coefficients. The procedure of recovering the coefficients is based on taking the double-uniform limit in certain series of smooth functions of two variables which is constructed according to a pre-determined iterative way. The result is obtained by using basic methods of mathematical analysis. We observe that the finiteness of the limit of this iterative chain of smooth functions should reflect itself in other mathematical constructions, too, since it is not related in any way to the explicit form of the MB transforms. This finite double-uniform limit is represented in terms of a differential operator with respect to an auxiliary parameter which acts on the integrand of a certain two-fold MB integral. To demonstrate that our result is compatible with original representations of UD functions, we reproduce the integrands of these original integral representations by applying this differential operator to the integrand of the simple integral representation of the scalar triangle four-dimensional integral J(1,1,1−ε)

  20. Nestling rearing is antioxidant demanding in female barn swallows ( Hirundo rustica)

    Science.gov (United States)

    Costantini, David; Bonisoli-Alquati, Andrea; Rubolini, Diego; Caprioli, Manuela; Ambrosini, Roberto; Romano, Maria; Saino, Nicola

    2014-07-01

    Reproduction is a demanding activity, since organisms must produce and, in some cases, protect and provision their progeny. Hence, a central tenet of life-history theory predicts that parents have to trade parental care against body maintenance. One physiological cost thought to be particularly important as a modulator of such trade-offs is oxidative stress. However, evidence in favour of the hypothesis of an oxidative cost of reproduction is contradictory. In this study, we manipulated the brood size of wild barn swallows Hirundo rustica soon after hatching of their nestlings to test whether an increase in nestling rearing effort translates into an increased oxidative damage and a decreased antioxidant protection at the end of the nestling rearing period. We found that, while plasma oxidative damage was unaffected by brood size enlargement, females rearing enlarged broods showed a decrease in plasma non-enzymatic antioxidants during the nestling rearing period. This was not the case among females rearing reduced broods and among males assigned to either treatment. Moreover, individuals with higher plasma oxidative damage soon after the brood size manipulation had lower plasma non-enzymatic antioxidants at the end of the nestling rearing period, suggesting that non-enzymatic antioxidants were depleted to buffer the negative effects of high oxidative damage. Our findings point to antioxidant depletion as a potential mechanism mediating the cost of reproduction among female birds.

  1. Input clustering in the normal and learned circuits of adult barn owls.

    Science.gov (United States)

    McBride, Thomas J; DeBello, William M

    2015-05-01

    Experience-dependent formation of synaptic input clusters can occur in juvenile brains. Whether this also occurs in adults is largely unknown. We previously reconstructed the normal and learned circuits of prism-adapted barn owls and found that changes in clustering of axo-dendritic contacts (putative synapses) predicted functional circuit strength. Here we asked whether comparable changes occurred in normal and prism-removed adults. Across all anatomical zones, no systematic differences in the primary metrics for within-branch or between-branch clustering were observed: 95-99% of contacts resided within clusters (<10-20 μm from nearest neighbor) regardless of circuit strength. Bouton volumes, a proxy measure of synaptic strength, were on average larger in the functionally strong zones, indicating that changes in synaptic efficacy contributed to the differences in circuit strength. Bootstrap analysis showed that the distribution of inter-contact distances strongly deviated from random not in the functionally strong zones but in those that had been strong during the sensitive period (60-250 d), indicating that clusters formed early in life were preserved regardless of current value. While cluster formation in juveniles appeared to require the production of new synapses, cluster formation in adults did not. In total, these results support a model in which high cluster dynamics in juveniles sculpt a potential connectivity map that is refined in adulthood. We propose that preservation of clusters in functionally weak adult circuits provides a storage mechanism for disused but potentially useful pathways. PMID:25701706

  2. Hunting Increases Phosphorylation of Calcium/Calmodulin-Dependent Protein Kinase Type II in Adult Barn Owls

    Directory of Open Access Journals (Sweden)

    Grant S. Nichols

    2015-01-01

    Full Text Available Juvenile barn owls readily adapt to prismatic spectacles, whereas adult owls living under standard aviary conditions do not. We previously demonstrated that phosphorylation of the cyclic-AMP response element-binding protein (CREB provides a readout of the instructive signals that guide plasticity in juveniles. Here we investigated phosphorylation of calcium/calmodulin-dependent protein kinase II (pCaMKII in both juveniles and adults. In contrast to CREB, we found no differences in pCaMKII expression between prism-wearing and control juveniles within the external nucleus of the inferior colliculus (ICX, the major site of plasticity. For prism-wearing adults that hunted live mice and are capable of adaptation, expression of pCaMKII was increased relative to prism-wearing adults that fed passively on dead mice and are not capable of adaptation. This effect did not bear the hallmarks of instructive information: it was not localized to rostral ICX and did not exhibit a patchy distribution reflecting discrete bimodal stimuli. These data are consistent with a role for CaMKII as a permissive rather than an instructive factor. In addition, the paucity of pCaMKII expression in passively fed adults suggests that the permissive default setting is “off” in adults.

  3. Reciprocal preening and food sharing in colour-polymorphic nestling barn owls.

    Science.gov (United States)

    Roulin, A; Des Monstiers, B; Ifrid, E; Da Silva, A; Genzoni, E; Dreiss, A N

    2016-02-01

    Barn owl (Tyto alba) siblings preen and offer food items to one another, behaviours that can be considered prosocial because they benefit a conspecific by relieving distress or need. In experimental broods, we analysed whether such behaviours were reciprocated, preferentially exchanged between specific phenotypes, performed to avoid harassment and food theft or signals of hierarchy status. Three of the results are consistent with the hypothesis of direct reciprocity. First, food sharing was reciprocated in three-chick broods but not in pairs of siblings, that is when nestlings could choose a partner with whom to develop a reciprocating interaction. Second, a nestling was more likely to give a prey item to its sibling if the latter individual had preened the former. Third, siblings matched their investment in preening each other. Manipulation of age hierarchy showed that food stealing was directed towards older siblings but was not performed to compensate for a low level of cooperation received. Social behaviours were related to melanin-based coloration, suggesting that animals may signal their propensity to interact socially. The most prosocial phenotype (darker reddish) was also the phenotype that stole more food, and the effect of coloration on prosocial behaviour depended upon rank and sex, suggesting that colour-related prosociality is state dependent. PMID:26563617

  4. A GPU accelerated Barnes-Hut tree code for FLASH4

    Science.gov (United States)

    Lukat, Gunther; Banerjee, Robi

    2016-05-01

    We present a GPU accelerated CUDA-C implementation of the Barnes Hut (BH) tree code for calculating the gravitational potential on octree adaptive meshes. The tree code algorithm is implemented within the FLASH4 adaptive mesh refinement (AMR) code framework and therefore fully MPI parallel. We describe the algorithm and present test results that demonstrate its accuracy and performance in comparison to the algorithms available in the current FLASH4 version. We use a MacLaurin spheroid to test the accuracy of our new implementation and use spherical, collapsing cloud cores with effective AMR to carry out performance tests also in comparison with previous gravity solvers. Depending on the setup and the GPU/CPU ratio, we find a speedup for the gravity unit of at least a factor of 3 and up to 60 in comparison to the gravity solvers implemented in the FLASH4 code. We find an overall speedup factor for full simulations of at least factor 1.6 up to a factor of 10.

  5. A GPU accelerated Barnes-Hut Tree Code for FLASH4

    CERN Document Server

    Lukat, Gunther

    2016-01-01

    We present a GPU accelerated CUDA-C implementation of the Barnes Hut (BH) tree code for calculating the gravita- tional potential on octree adaptive meshes. The tree code algorithm is implemented within the FLASH4 adaptive mesh refinement (AMR) code framework and therefore fully MPI parallel. We describe the algorithm and present test results that demonstrate its accuracy and performance in comparison to the algorithms available in the current FLASH4 version. We use a MacLaurin spheroid to test the accuracy of our new implementation and use spherical, collapsing cloud cores with effective AMR to carry out performance tests also in comparison with previous gravity solvers. Depending on the setup and the GPU/CPU ratio, we find a speedup for the gravity unit of at least a factor of 3 and up to 60 in comparison to the gravity solvers implemented in the FLASH4 code. We find an overall speedup factor for full simulations of at least factor 1.6 up to a factor of 10

  6. “And all the windows, great and small”. Finestre in Nightwood di Djuna Barnes

    Directory of Open Access Journals (Sweden)

    Francesca Chiappini

    2015-01-01

    Full Text Available As a recurring subject and powerful symbol, the window dominates the female literary and artistic imagery of the twentieth century. It has been developed into mirror, photograph or painting, according to the writer’s needs, yet the basic shape of the frame is always retraceable. Among late modernist and postmodernist women writers, Djuna Barnes explores in detail the structural resources of this literary device. Although she already understands the potential of the frame in her early career as a journalist, she mostly challenges its extents of versatility in Nightwood (1936. Its crucial moments – either flashing epiphanies or missed catharsis – involve the physical presence of a window, which embodies a powerful narrative agent; more than mere symbol, it is active at several levels. Thematically, doors and windows, pictures and mirrors, play an important cohesive role. At a deeper stage of analysis, the structure of the novel itself is shored up by doors and windows, since the setting is essentially organized into indoors and outdoors scenes; windows and doors allow the characters to move between these two dimensions. On the metaphorical level, windows and doors represent a communicative channel; a room-door opening suggests the access to one’s inner life, whereas a shut window denies any chance of dialogue. However, all the characters seem to be too absorbed by their obsessions to realize such communicative potential, and rather meander uselessly in their mental frames.

  7. Research reactors

    International Nuclear Information System (INIS)

    This article proposes an overview of research reactors, i.e. nuclear reactors of less than 100 MW. Generally, these reactors are used as neutron generators for basic research in matter sciences and for technological research as a support to power reactors. The author proposes an overview of the general design of research reactors in terms of core size, of number of fissions, of neutron flow, of neutron space distribution. He outlines that this design is a compromise between a compact enough core, a sufficient experiment volume, and high enough power densities without affecting neutron performance or its experimental use. The author evokes the safety framework (same regulations as for power reactors, more constraining measures after Fukushima, international bodies). He presents the main characteristics and operation of the two families which represent almost all research reactors; firstly, heavy water reactors (photos, drawings and figures illustrate different examples); and secondly light water moderated and cooled reactors with a distinction between open core pool reactors like Melusine and Triton, pool reactors with containment, experimental fast breeder reactors (Rapsodie, the Russian BOR 60, the Chinese CEFR). The author describes the main uses of research reactors: basic research, applied and technological research, safety tests, production of radio-isotopes for medicine and industry, analysis of elements present under the form of traces at very low concentrations, non destructive testing, doping of silicon mono-crystalline ingots. The author then discusses the relationship between research reactors and non proliferation, and finally evokes perspectives (decrease of the number of research reactors in the world, the Jules Horowitz project)

  8. Reactor physics and reactor computations

    International Nuclear Information System (INIS)

    Mathematical methods and computer calculations for nuclear and thermonuclear reactor kinetics, reactor physics, neutron transport theory, core lattice parameters, waste treatment by transmutation, breeding, nuclear and thermonuclear fuels are the main interests of the conference

  9. Research reactors

    International Nuclear Information System (INIS)

    There are currently 284 research reactors in operation, and 12 under construction around the world. Of the operating reactors, nearly two-thirds are used exclusively for research, and the rest for a variety of purposes, including training, testing, and critical assembly. For more than 50 years, research reactor programs have contributed greatly to the scientific and educational communities. Today, six of the world's research reactors are being shut down, three of which are in the USA. With government budget constraints and the growing proliferation concerns surrounding the use of highly enriched uranium in some of these reactors, the future of nuclear research could be impacted

  10. Reactor container

    International Nuclear Information System (INIS)

    Object: To provide a jet and missile protective wall of a configuration being inflated toward the center of a reactor container on the inside of a body of the reactor container disposed within a biological shield wall to thereby increase safety of the reactor container. Structure: A jet and missile protective wall comprised of curved surfaces internally formed with a plurality of arch inflations filled with concrete between inner and outer iron plates and shape steel beam is provided between a reactor container surrounded by a biological shield wall and a thermal shield wall surrounding the reactor pressure vessel, and an adiabatic heat insulating material is filled in space therebetween. (Yoshino, Y.)

  11. Klatring i trær og hyttebygging: - om barns lek og lekesteder ute

    Directory of Open Access Journals (Sweden)

    Merete Lund Fasting

    2015-07-01

    Full Text Available Abstract: This article describes 10 year old children`s play in nature during school hours. However, my result does equally reflect on children in kindergarden as well. Observation and conversation was used as methods as well as pictures. The children’s play in the trees and building huts was conducted in groups, and their communication was nonverbal with each other and with the nature. However; the girls reveal that they enjoy their conversations while being in the tree. The children often play at the same place over and over. This is significant to the evolution of the play and the children’s communication with their places in nature.Sammendrag: Denne artikkelen omhandler 10 år gamle barns lek på natursteder i skoletida. Selv om studien omhandler 10 åringer så kan kunnskapen den frembringer også være viktig for å forstå barnehagebarns lek og tilknytning til sine lekesteder i barnehagen. Metodene som ble brukt for å undersøke barnas lek var observasjoner og samtaler med barna, i tillegg til fotografier. Barnas lek i trærne og i hyttebyggingen karakteriseres ved at de er flere sammen, og barna har en kroppslig dialog med hverandre og omgivelsene i leken. Barna snakker i liten grad sammen om leken og hvordan de skal leke; deres kommunikasjon er hovedsakelig nonverbal. Men når jentene sitter i treet forteller de meg at de liker å sitte og snakke. Barna leker på steder hvor de har vært mye før, og dette har en betydning for barnas lek og barnas kommunikasjon med deres steder.

  12. Sexual dimorphism in melanin pigmentation, feather coloration and its heritability in the barn swallow (Hirundo rustica.

    Directory of Open Access Journals (Sweden)

    Nicola Saino

    Full Text Available Melanin is the main pigment in animal coloration and considerable variation in the concentrations of the two melanin forms (pheo- and eumlanin in pigmented tissues exists among populations and individuals. Melanin-based coloration is receiving increasing attention particularly in socio-sexual communication contexts because the melanocortin system has been hypothesized to provide a mechanistic basis for covariation between coloration and fitness traits. However, with few notable exceptions, little detailed information is available on inter-individual and inter-population variation in melanin pigmentation and on its environmental, genetic and ontogenetic components. Here, we investigate melanin-based coloration in an Italian population of a passerine bird, the barn swallow (Hirundo rustica rustica, its sex- and age-related variation, and heritability. The concentrations of eu- and pheomelanin in the throat (brown and belly (white-to-brownish feathers differed between sexes but not according to age. The relative concentration of either melanin (Pheo:Eu differed between sexes in throat but not in belly feathers, and the concentrations in males compared to females were larger in belly than in throat feathers. There were weak correlations between the concentrations of melanins within as well as among plumage regions. Coloration of belly feathers was predicted by the concentration of both melanins whereas coloration of throat feathers was only predicted by pheomelanin in females. In addition, Pheo:Eu predicted coloration of throat feathers in females and that of belly feathers in males. Finally, we found high heritability of color of throat feathers. Melanization was found to differ from that recorded in Hirundo rustica rustica from Scotland or from H. r. erythrogaster from North America. Hence, present results show that pigmentation strategies vary in a complex manner according to sex and plumage region, and also among geographical populations

  13. Barn owl feathers as biomonitors of mercury: sources of variation in sampling procedures.

    Science.gov (United States)

    Roque, Inês; Lourenço, Rui; Marques, Ana; Coelho, João Pedro; Coelho, Cláudia; Pereira, Eduarda; Rabaça, João E; Roulin, Alexandre

    2016-04-01

    Given their central role in mercury (Hg) excretion and suitability as reservoirs, bird feathers are useful Hg biomonitors. Nevertheless, the interpretation of Hg concentrations is still questioned as a result of a poor knowledge of feather physiology and mechanisms affecting Hg deposition. Given the constraints of feather availability to ecotoxicological studies, we tested the effect of intra-individual differences in Hg concentrations according to feather type (body vs. flight feathers), position in the wing and size (mass and length) in order to understand how these factors could affect Hg estimates. We measured Hg concentration of 154 feathers from 28 un-moulted barn owls (Tyto alba), collected dead on roadsides. Median Hg concentration was 0.45 (0.076-4.5) mg kg(-1) in body feathers, 0.44 (0.040-4.9) mg kg(-1) in primary and 0.60 (0.042-4.7) mg kg(-1) in secondary feathers, and we found a poor effect of feather type on intra-individual Hg levels. We also found a negative effect of wing feather mass on Hg concentration but not of feather length and of its position in the wing. We hypothesize that differences in feather growth rate may be the main driver of between-feather differences in Hg concentrations, which can have implications in the interpretation of Hg concentrations in feathers. Finally, we recommend that, whenever possible, several feathers from the same individual should be analysed. The five innermost primaries have lowest mean deviations to both between-feather and intra-individual mean Hg concentration and thus should be selected under restrictive sampling scenarios. PMID:26718850

  14. A trade-off between reproduction and feather growth in the barn swallow (Hirundo rustica.

    Directory of Open Access Journals (Sweden)

    Nicola Saino

    Full Text Available Physiological trade-offs mediated by limiting energy, resources or time constrain the simultaneous expression of major functions and can lead to the evolution of temporal separation between demanding activities. In birds, plumage renewal is a demanding activity, which accomplishes fundamental functions, such as allowing thermal insulation, aerodynamics and socio-sexual signaling. Feather renewal is a very expensive and disabling process, and molt is often partitioned from breeding and migration. However, trade-offs between feather renewal and breeding have been only sparsely studied. In barn swallows (Hirundo rustica breeding in Italy and undergoing molt during wintering in sub-Saharan Africa, we studied this trade-off by removing a tail feather from a large sample of individuals and analyzing growth bar width, reflecting feather growth rate, and length of the growing replacement feather in relation to the stage in the breeding cycle at removal and clutch size. Growth bar width of females and length of the growing replacement feather of both sexes were smaller when the original feather had been removed after clutch initiation. Importantly, in females both growth bar width and replacement feather length were negatively predicted by clutch size, and more strongly so for large clutches and when feather removal occurred immediately after clutch completion. Hence, we found strong, coherent evidence for a trade-off between reproduction, and laying effort in particular, and the ability to generate new feathers. These results support the hypothesis that the derived condition of molting during wintering in long-distance migrants is maintained by the costs of overlapping breeding and molt.

  15. Effect of summer grazing on welfare of dairy cows reared in mountain tie-stall barns

    Directory of Open Access Journals (Sweden)

    Simonetta Dovier

    2010-09-01

    Full Text Available Traditional mountain farms have an important economic, social and environmental role. The Alps management system for dairy cows consists of animals kept indoors from autumn to spring, mostly in tie-stalls, and moved to mountain pasture in summer. The aim of our study was to assess the effect of mountain summer grazing on the welfare of dairy cows housed in tie-stall barns. Twenty-four farms were considered. In twelve of them, animals were reared in tie-stalls and moved to mountain pasture for three months in summer; they were visited three times: (i four weeks before grazing during the indoor period in the stall; (ii about three weeks after the start of grazing; and (iii in the stall, in autumn, at least three weeks after returning from grazing. The other twelve farms kept the animals in tie-stalls all year; they were visited once in autumn. Data were collected following a protocol that considers animal-based measures and structure information on the basis of Quality Welfare Consortium® indications. Data allowed the calculation of both the Animal Needs Index score (ANI 35L and an overall assessment of the cows’ welfare obtained from three general aspects: housing, animal’s physical condition, and animal’s behaviour. Summer grazing had a significant positive effect on injuries, lameness and animal’s rising duration but a negative effect on faeces consistency. Moreover, a reduction of tongue playing was observed. The ANI 35L and the overall assessment did not show significant differences linked to summer grazing, which tended to have a positive but temporary effect on animal behaviour.

  16. Cooling systems of the resting area in free stall dairy barn

    Science.gov (United States)

    Calegari, F.; Calamari, L.; Frazzi, E.

    2016-04-01

    A study during the summer season evaluated the effect of different cooling systems on behavioral and productive responses of Italian Friesian dairy cows kept in an experimental-free stall barn located in the Po Valley in Italy. The study involved 30 lactating dairy cows subdivided into two groups kept in two pens with external hard court paddock in each free stall. The same cooling system was applied in the feeding area in both pens. A different cooling system in the resting area was applied to the two pens: in the pen SW, the resting area was equipped with fans and misters; in the other, there was simple ventilation (SV). Breathing rate, rectal temperature, milk yield, and milk characteristics (fat, protein, and somatic cell count) were measured. Behavioral activities (standing and lying cows in the different areas, as well as the animals in the feed bunk) were recorded. Mild to moderate heat waves during the trial were observed. On average, the breathing rate was numerically greater in SV compared with SW cows (60.2 and 55.8 breath/min, respectively), and mean rectal temperature remained below 39 °C in both groups during the trial (on average 38.7 and 38.8 °C in SV and SW, respectively. During the hotter periods of the trial, the time spent lying indoor in the free stall was greater in SW (11.8 h/day) than SV (10.7 h/day). Conversely, the time spent standing indoor without feeding was greater in SV (4.3 h/day) than SW (3.8 h/day). Milk yield was slightly better maintained during hotter period in SW compared with SV and somatic cell count was also slightly greater in the former. In conclusion, the adoption of the cooling system by means of evaporative cooling also in the resting area reduces the alteration of time budget caused by heat stress.

  17. Clock gene variation is associated with breeding phenology and maybe under directional selection in the migratory barn swallow.

    Directory of Open Access Journals (Sweden)

    Manuela Caprioli

    Full Text Available BACKGROUND: In diverse taxa, photoperiodic responses that cause seasonal physiological and behavioural shifts are controlled by genes, including the vertebrate Clock orthologues, that encode for circadian oscillator mechanisms. While the genetic network behind circadian rhythms is well described, relatively few reports exist of the phenological consequences of and selection on Clock genes in the wild. Here, we investigated variation in breeding phenology in relation to Clock genetic diversity in a long-distance migratory bird, the barn swallow (Hirundo rustica. METHODOLOGY/PRINCIPAL FINDINGS: In a sample of 922 adult barn swallows from a single population breeding in Italy we found one very common (Q(7 and three rare (Q(5, Q(6, Q(8 length variants of a functionally significant polyglutamine repeat. Rare (2.9% Q(7/Q(8 heterozygous females, but not males, bred significantly later than common (91.5% Q(7/Q(7 females, consistent with the expectation that 'long' alleles cause late breeding, as observed in a resident population of another bird species. Because breeding date depends on arrival date from migration, present results suggest that the association between breeding date and Clock might be mediated by migration phenology. In addition, fecundity selection appears to be operating against Q(7/Q(8 because late migrating/breeding swallows have fewer clutches per season, and late breeding has additional negative selection effects via reduced offspring longevity. Genotype frequencies varied marginally non-significantly with age, as Q(7/Q(8 frequency showed a 4-fold reduction in old individuals. This result suggests negative viability selection against Q(7/Q(8, possibly mediated by costs of late breeding. CONCLUSIONS/SIGNIFICANCE: This is the first study of migratory birds showing an association between breeding phenology and Clock genotype and suggesting that negative selection occurs on a phenologically deviant genotype. Low polymorphism at Clock may

  18. Low degradable protein supply to increase nitrogen efficiency in lactating dairy cows and reduce environmental impacts at barn level.

    Science.gov (United States)

    Edouard, N; Hassouna, M; Robin, P; Faverdin, P

    2016-02-01

    Generally, effect of lowering dietary degradable nitrogen supplies--while maintaining metabolisable protein--on dairy cows' performance, nitrogen use efficiency and gas emissions (NH3, N2O, CH4) at barn level with tied animals. Two dietary N concentrations (CP: 12% DM for LowN; 18% DM for HighN) were offered to two groups of three lactating dairy cows in a split-plot design over four periods of 2 weeks. Diets were formulated to provide similar metabolisable protein supply, with degradable N either in deficit or in excess (PDIN of 84 and 114 g/kg DM for LowN and HighN, respectively). Cows ingested 0.8 kg DM/day less on the LowN diet, which was also 2.5% less digestible. Milk yield and composition were not significantly affected. N exported in milk was 5% lower (LowN: 129 g N/day; HighN: 136 g N/day; Pprotein yield was not significantly affected (LowN: 801 g/day; HighN: 823 g/day; P=0.10). Cows logically ingested less nitrogen on the LowN diet (LowN: 415 g N/day; HighN: 626 g N/day; Pdiet (LowN: 65 g N/day; HighN: 243 g N/day; Pdiet (LowN: 1.03 g/h per cow; HighN: 1.25 g/h per cow; Pprotein with suitable metabolisable protein amounts to cattle improved nitrogen use efficiency and lowered ammonia emissions at barn level. This strategy would, however, need to be validated for longer periods, other housing systems (free stall barns) and at farm level including all stages of manure management. PMID:26412234

  19. Final work plan : targeted groundwater sampling and monitoring well installation for potential site reclassification at Barnes, Kansas.

    Energy Technology Data Exchange (ETDEWEB)

    LaFreniere, L. M.

    2006-07-11

    This ''Work Plan'' outlines the scope of work for a targeted groundwater sampling investigation and monitoring well installation at Barnes, Kansas. This activity is being conducted at the request of the Kansas Department of Health and Environment (KDHE), in accordance with the intergovernmental agreement between the KDHE and the Commodity Credit Corporation (CCC), an agency of the U.S. Department of Agriculture (USDA). Data resulting from the proposed work will be used to determine the hydraulic gradient near the former CCC/USDA facility, delineate the downgradient carbon tetrachloride plume, and determine additional monitoring requirements at Barnes. The overall goal is to establish criteria for monitoring leading to potential site reclassification. The proposed work will be performed on behalf of the CCC/USDA by the Environmental Science Division of Argonne National Laboratory. Argonne is a nonprofit, multidisciplinary research center operated by the University of Chicago for the U.S. Department of Energy (DOE). The Farm Service Agency of the USDA has entered into an interagency agreement with DOE, under which Argonne provides technical assistance with environmental site characterization and remediation at former CCC/USDA grain storage facilities. Argonne issued a ''Master Work Plan'' (Argonne 2002) to provide general guidance for all investigations at former CCC/USDA facilities in Kansas. The ''Master Work Plan'', approved by the KDHE, contains the materials common to investigations at all locations in Kansas. This document must be consulted for the complete details of plans for this work associated with the former CCC/USDA facility at Barnes.

  20. Sexual Dimorphism and Population Differences in Structural Properties of Barn Swallow (Hirundo rustica Wing and Tail Feathers.

    Directory of Open Access Journals (Sweden)

    Péter L Pap

    Full Text Available Sexual selection and aerodynamic forces affecting structural properties of the flight feathers of birds are poorly understood. Here, we compared the structural features of the innermost primary wing feather (P1 and the sexually dimorphic outermost (Ta6 and monomorphic second outermost (Ta5 tail feathers of barn swallows (Hirundo rustica from a Romanian population to investigate how sexual selection and resistance to aerodynamic forces affect structural differences among these feathers. Furthermore, we compared structural properties of Ta6 of barn swallows from six European populations. Finally, we determined the relationship between feather growth bars width (GBW and the structural properties of tail feathers. The structure of P1 indicates strong resistance against aerodynamic forces, while the narrow rachis, low vane density and low bending stiffness of tail feathers suggest reduced resistance against airflow. The highly elongated Ta6 is characterized by structural modifications such as large rachis width and increased barbule density in relation to the less elongated Ta5, which can be explained by increased length and/or high aerodynamic forces acting at the leading tail edge. However, these changes in Ta6 structure do not allow for full compensation of elongation, as reflected by the reduced bending stiffness of Ta6. Ta6 elongation in males resulted in feathers with reduced resistance, as shown by the low barb density and reduced bending stiffness compared to females. The inconsistency in sexual dimorphism and in change in quality traits of Ta6 among six European populations shows that multiple factors may contribute to shaping population differences. In general, the difference in quality traits between tail feathers cannot be explained by the GBW of feathers. Our results show that the material and structural properties of wing and tail feathers of barn swallows change as a result of aerodynamic forces and sexual selection, although the

  1. Natural selection in a postglacial range expansion: the case of the colour cline in the European barn owl.

    Science.gov (United States)

    Antoniazza, Sylvain; Kanitz, Ricardo; Neuenschwander, Samuel; Burri, Reto; Gaigher, Arnaud; Roulin, Alexandre; Goudet, Jérôme

    2014-11-01

    Gradients of variation--or clines--have always intrigued biologists. Classically, they have been interpreted as the outcomes of antagonistic interactions between selection and gene flow. Alternatively, clines may also establish neutrally with isolation by distance (IBD) or secondary contact between previously isolated populations. The relative importance of natural selection and these two neutral processes in the establishment of clinal variation can be tested by comparing genetic differentiation at neutral genetic markers and at the studied trait. A third neutral process, surfing of a newly arisen mutation during the colonization of a new habitat, is more difficult to test. Here, we designed a spatially explicit approximate Bayesian computation (ABC) simulation framework to evaluate whether the strong cline in the genetically based reddish coloration observed in the European barn owl (Tyto alba) arose as a by-product of a range expansion or whether selection has to be invoked to explain this colour cline, for which we have previously ruled out the actions of IBD or secondary contact. Using ABC simulations and genetic data on 390 individuals from 20 locations genotyped at 22 microsatellites loci, we first determined how barn owls colonized Europe after the last glaciation. Using these results in new simulations on the evolution of the colour phenotype, and assuming various genetic architectures for the colour trait, we demonstrate that the observed colour cline cannot be due to the surfing of a neutral mutation. Taking advantage of spatially explicit ABC, which proved to be a powerful method to disentangle the respective roles of selection and drift in range expansions, we conclude that the formation of the colour cline observed in the barn owl must be due to natural selection. PMID:25294501

  2. Stödjande av barns sociala färdigheter och delaktighet i vardagen : Om möjligheter och utmaningar i arbetet på mottagningshem

    OpenAIRE

    Larinkoski, Miriam

    2014-01-01

    Syftet med detta examensarbete är att ge ökad kunskap om hur de professionella på ett mottagningshem kan stöda barns sociala färdigheter och delaktighet i vardagen. Detta examensarbete är ett beställningsarbete av ett mottagningshem i södra Finland. Frågeställningarna är: Hur kan professionella med hjälp av en miljöterapeutisk arbetsmetod på mottagningshem främja barns sociala färdigheter samt stöda barns delaktighet i var-dagen? Vilka är utmaningarna för de professionella i att förverkliga ...

  3. "Jag vill nog bara lära mig" : Barns upplevelser av och ambitioner med sitt musicerande inom och utom ramen för frivillig musikundervisning

    OpenAIRE

    Lidén, Ellinor

    2007-01-01

    Syftet med denna uppsats är att genom intervjusamtal och enkäter få ökad insikt i samt beskriva hur musicerande barn uttrycker sina upplevelser av och ambitioner med sitt musicerande, såväl inom som utom ramen för frivillig musikundervisning. Det empiriska materialet består av 95 enkätsvar samt information från intervjusamtal med nio barn. Samtliga barn var mellan åtta och tretton år. Studien vilar på en kulturteoretisk ram, vilken utgör fonden för studiens övriga teoretiska utgångspunkter. S...

  4. Förälder till barn/ungdom med ätstörning – upplevelser och erfarenheter : En litteraturstudie

    OpenAIRE

    Kramer, Helena

    2015-01-01

    SAMMANFATTNING Bakgrund: Vid behandling av ätstörningar hos barn och ungdomar konstateras att föräldrars delaktighet har en betydande roll. Sjuksköterskan kan möta föräldrar till barn och ungdomar med ätstörning inom olika vårdinstanser och vårdformer och för att kunna ge stöd och god omvårdnad med familjen i fokus, är det av intresse att belysa upplevelser och erfarenheter hos föräldrar, av att leva med och/eller vårda barn/ungdom med ätstörning. Syfte: Att beskriva föräldrars upplevelser o...

  5. Stimulera intresse för naturkunskap : En studie av hur förskollärare stimulerar barns intresse för naturkunskap

    OpenAIRE

    Jonsson, Linda

    2014-01-01

    Små barn visar tidigt intresse för naturkunskap och det är förskolans uppdrag att fånga upp och ta tillvara detta intresse. Examensarbetet syftar till att undersöka hur förskollärare arbetar för att stimulera barns intresse för naturkunskap. Studien baseras på sex kvalitativa intervjuer med förskollärare från tre olika förskolor i en medelstor svensk stad. Studien behandlar hur förskollärare ser på innebörden av ett utforskande arbetssätt samt hur de tar barns intresse för naturkunskap vidare...

  6. Lek och Skoj! : Ett motionsprogram för barn i 5-6 års ålder med övervikt

    OpenAIRE

    Erlund, Cecilia; Erlund, Alexandra; Johansson, Pamela; Lahti, Annika; Ljungberg, Caroline

    2014-01-01

    Examensarbetet är ett delprojekt inom projektet ”Det resilienta barnet”. Syftet med arbetet är att skapa ett motionsprogram för barn i 5-6 års ålder med övervikt oberoende av föräldrars engagemang. Frågeställningar som besvaras är ”Hur kan de professionella stärka motivation till motion hos barn med övervikt?” och ”Hur bygga upp ett motionsprogram?” Barn i dagens samhälle ägnar sig åt en allt mer passiv livsstil eftersom en stor del av fritiden går åt till stillasittande aktiviteter så s...

  7. Konduktiv pedagogik som fysioterapimetod för barn och unga med funktionsnedsättningar : En systematisk litteraturstudie

    OpenAIRE

    Norrvik, Jessica

    2013-01-01

    Konduktiv pedagogik (KP) är en holistiskt specialpedagogisk undervisningsmetod som främst riktar sig till barn och unga med funktionsnedsättningar. Genom metoden vill man utveckla barnets hela personlighet och på så vis uppnå en förbättrad funktionsförmåga. Träningen riktar sig därför till barnets fysiska, sociala, kognitiva och emotionella utveckling. Programmet leds av en så kallad conductor som kan sägas vara en sammanslagning av fysioterapeut, ergoterapeut, psykolog och lärare. Syftet...

  8. Interaktion mellan små barn med Cerebral Pares och deras vardagliga samtalspartners på förskolan

    OpenAIRE

    Brolin, Lina; Karlsson, Lina

    2014-01-01

    Det övergripande syftet med denna studie var att öka kunskapen om hur små barn med Cerebral Pares (CP) deltar, kommunicerar och interagerar med sina vardagliga samtalspartners på förskolan. I studien deltog två små pojkar (2;4 och 4;3 år) med grav CP (GMFCS 5) med lite/inget talat språk. De filmades på förskolan i olika vardagliga aktiviteter tillsammans med de andra barnen och personalen. Vid analysen studerades pojkarnas samlade kommunikativa resurser och återkommande mönster i samtalen på ...

  9. Sambandet mellan skärmtid och hälsa bland barn och unga - En systematisk litteraturgranskning

    OpenAIRE

    Isotalo, Katarina

    2013-01-01

    Den tidigare forskningen visar att media samt mediefostran är en ny utmaning för föräldrar, vårdnadshavare och andra aktiva aktörer i barn och ungas liv. Människans ständiga utveckling, styrs av inre värden och principer, som bildas genom möjligheter, regler och exempel som omgivningen erbjuder. (Parse 1997:23) Detta är en systematisk litteraturstudie där 12 stycken forskningar analyserats och samlats in från tre olika databaser. I analysen granskades kvaliteten på artiklarna. Studien är ett ...

  10. Kirkens diakonale arbeid i møte med barn som sørger etter tap av forelder

    OpenAIRE

    Jørgensen, Benedicte

    2012-01-01

    I denne oppgaven vil jeg sette fokus på et viktig og, etter min opplevelse, lite prioritert område innenfor kirken/diakonien. Diakonens rolle og menighetens diakonale ansvar og muligheter vil gå som en rød tråd gjennom hele oppgaven. Noen kan mene at det er unødvendig å skrive en masteroppgave om barn og sorg og hvordan kirken kan drive sorgarbeid, når det offentlige allerede har noen tilbud. Som tidligere referert kan det virke som om det offentliges tilbud ikke er tilstrekkel...

  11. EVALUATION OF PERCEIVED QUALITY OF THE WEBSITE OF AN ONLINE BOOKSTORE: AN EMPIRICAL APPLICATION OF THE BARNES AND VIDGEN MODEL

    Directory of Open Access Journals (Sweden)

    Ueliton da Costa Leonidio

    2011-05-01

    Full Text Available This paper’s objective is to evaluate the perceived quality of the Website of an online bookstore using the Barnes and Vidgen Model. Implemented over the Internet, this empirical research collected data on the perceived quality of the Website, used to sell products and online services. The questionnaire used to gather the data was answered by a convenience sample of 213 respondents. The importance of quality attributes and the dimension of perceived quality were investigated. The results indicate that the three dimensions named Reliability, Usability and Information were the most noticeable.

  12. Reactor building

    International Nuclear Information System (INIS)

    The whole reactor building is accommodated in a shaft and is sealed level with the earth's surface by a building ceiling, which provides protection against penetration due to external effects. The building ceiling is supported on walls of the reactor building, which line the shaft and transfer the vertical components of forces to the foundations. The thickness of the walls is designed to withstand horizontal pressure waves in the floor. The building ceiling has an opening above the reactor, which must be closed by cover plates. Operating equipment for the reactor can be situated above the building ceiling. (orig./HP)

  13. Heterogeneous reactors

    International Nuclear Information System (INIS)

    The microscopic study of a cell is meant for the determination of the infinite multiplication factor of the cell, which is given by the four factor formula: K(infinite) = n(epsilon)pf. The analysis of an homogeneous reactor is similar to that of an heterogeneous reactor, but each factor of the four factor formula can not be calculated by the formulas developed in the case of an homogeneous reactor. A great number of methods was developed for the calculation of heterogeneous reactors and some of them are discussed. (Author)

  14. Final report : results of the 2006-2007 investigation of potential contamination at the former CCC/USDA facility in Barnes, Kansas.

    Energy Technology Data Exchange (ETDEWEB)

    LaFreniere, L. M.; Environmental Science Division

    2008-08-28

    The 2006-2007 investigation of carbon tetrachloride and chloroform contamination at Barnes, Kansas, was conducted at the request of the Kansas Department of Health and Environment (KDHE). The Environmental Science Division of Argonne National Laboratory implemented the investigation on behalf of the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA). The overall goal of the investigation was to establish criteria for monitoring leading to potential site reclassification. The investigation objectives were to (1) determine the hydraulic gradient near the former CCC/USDA facility, (2) delineate the downgradient carbon tetrachloride plume, and (3) design and implement an expanded monitoring network at Barnes (Argonne 2006a).

  15. Plasma reactor

    OpenAIRE

    Molina Mansilla, Ricardo; Erra Serrabasa, Pilar; Bertrán Serra, Enric

    2008-01-01

    [EN] A plasma reactor that can operate in a wide pressure range, from vacuum and low pressures to atmospheric pressure and higher pressures. The plasma reactor is also able to regulate other important settings and can be used for processing a wide range of different samples, such as relatively large samples or samples with rough surfaces.

  16. Reactor physics

    International Nuclear Information System (INIS)

    Progress in research on reactor physics in 1997 at the Belgian Nuclear Research Centre SCK/CEN is described. Activities in the following four domains are discussed: core physics, ex-core neutron transport, experiments in Materials Testing Reactors, international benchmarks

  17. Study of heat-stress levels in naturally ventilated sheep barns during heat waves: development and assessment of regression models

    Science.gov (United States)

    Papanastasiou, D. K.; Bartzanas, T.; Panagakis, P.; Zhang, G.; Kittas, C.

    2016-03-01

    It is well documented that heat-stress burdens sheep welfare and productivity. Peak heat-stress levels are observed when high temperatures prevail, i.e. during heat waves; however, continuous measurements inside livestock buildings are not usually available for long periods so as to study the variation of summer heat-stress levels for several years, especially during extreme hot weather. Α methodology to develop a long time series of summer temperature and relative humidity inside naturally ventilated sheep barns is proposed. The accuracy and the transferability of the developed linear regression models were verified. Temperature Humidity Index (THI) was used to assess sheep's potential heat-stress. Τhe variation of THI inside a barn during heat wave and non-heat wave days was examined, and the results were comparatively assessed. The analysis showed that sheep were exposed to moderate, severe, and extreme severe heat-stress in 10, 21 and 66 % of hours, respectively, during heat wave days, while the corresponding values during non-heat wave days were 14, 33 and 43 %, respectively. The heat load on sheep was much higher during heat wave events than during non-heat wave periods. Additionally, based on the averaged diurnal variation of THI, it was concluded that extreme severe heat-stress conditions were prevailing between 1000 and 2400 hours local time during heat wave days. Cool off night periods were never and extremely rarely detected during heat wave and non-heat wave days, respectively.

  18. a Comparison of Laser Scanning and Structure from Motion as Applied to the Great Barn at Harmondsworth, UK

    Science.gov (United States)

    Andrews, D. P.; Bedford, J.; Bryan, P. G.

    2013-07-01

    The great barn at Harmondsworth near London Heathrow airport, United Kingdom (UK), was built in 1426-7 for the Bishop of Winchester. At 58 metres long and 11.4 metres wide, it is one of the largest ever known to have been built in the UK, and the largest intact medieval timber-framed barn in England. The barn is built almost entirely of oak, although the walls rest on a low masonry sill-wall. Internally the space is divided into a central "nave" with a lower aisle to each side, and is divided along its length into 12 bays. There are three doorways on the east side. For an entirely timber-framed barn, the fabric is exceptionally well preserved. Even the external weatherboarding may be partly original. Following years of neglect, however, there are a number of on-going structural and conservation problems, so in 2011 the barn was bought by English Heritage in order to allow these needs to be addressed. English Heritage is the government agency responsible for the historic sites and buildings in the care of the state of England and is also the UK government's lead advisor on the built heritage. As one of the first steps in the conservation process the English Heritage Geospatial Imaging and Imaging & Visualisation teams undertook a four-day campaign of survey data collection. This took the form of laser scanning of the interior and exterior of the barn plus the acquisition of photography of the exterior elevations to be used with structure from motion (SFM) software. A comparison of the results of these complimentary yet potentially competing technologies will be given, as well as an evaluation of when they can be successfully used together. This paper will describe the procedures and problems involved with collecting the survey data and its subsequent analysis. The laser scanning was undertaken using a FARO Focus 3D phase based instrument. Approximately 60 scans were acquired in order to provide as comprehensive as possible coverage given the site circumstances. A

  19. Muscular Arrangement and Muscle Attachment Sites in the Cervical Region of the American Barn Owl (Tyto furcata pratincola.

    Directory of Open Access Journals (Sweden)

    Mark L L M Boumans

    Full Text Available Owls have the largest head rotation capability amongst vertebrates. Anatomical knowledge of the cervical region is needed to understand the mechanics of these extreme head movements. While data on the morphology of the cervical vertebrae of the barn owl have been provided, this study is aimed to provide an extensive description of the muscle arrangement and the attachment sites of the muscles on the owl's head-neck region. The major cervical muscles were identified by gross dissection of cadavers of the American barn owl (Tyto furcata pratincola, and their origin, courses, and insertion were traced. In the head-neck region nine superficial larger cervical muscles of the craniocervical, dorsal and ventral subsystems were selected for analysis, and the muscle attachment sites were illustrated in digital models of the skull and cervical vertebrae of the same species as well as visualised in a two-dimensional sketch. In addition, fibre orientation and lengths of the muscles and the nature (fleshy or tendinous of the attachment sites were determined. Myological data from this study were combined with osteological data of the same species. This improved the anatomical description of the cervical region of this species. The myological description provided in this study is to our best knowledge the most detailed documentation of the cervical muscles in a strigiform species presented so far. Our results show useful information for researchers in the field of functional anatomy, biomechanical modelling and for evolutionary and comparative studies.

  20. Comparison of aviary, barn and conventional cage raising of chickens on laying performance and egg quality.

    Science.gov (United States)

    Ahammed, M; Chae, B J; Lohakare, J; Keohavong, B; Lee, M H; Lee, S J; Kim, D M; Lee, J Y; Ohh, S J

    2014-08-01

    This study intended to compare the productive performance of three different layer raising systems; conventional cage (CC), barn (BR) and aviary (AV). The AV is welfare bestowed housing that allows free locomotion for birds within the BR. The BR allows bird's free locomotion inside BR but without multilevel structures. Both pullets and cockerels were housed together in both AV and BR, but only pullets in CC. Seventeen weeks old Lohmann Brown Lite (n = 800) pullets were housed in AV during this study. The same age layer pullets were simultaneously assigned to either at CC or BR to compare egg production performance with AV. The duration of experiment was 40 weeks (from 21st to 60th week). There were no remarkable differences in egg production, hen day egg production (HDEP) and average egg weight among three rearing systems. First 20 weeks (phase-1) average HDEP (%) of AV, CC, and BR were 85.9, 88.8, 87.1 and average egg weights (g) were 57.5, 59.9, and 56.9 respectively. Those of the remaining 20 weeks (phase-2) were 87.1, 87.9, 85.5 and 64.2, 63.0 62.1, respectively. Daily feed intakes (122 g, 110 g, 125 g); feed conversion ratio (2.4, 2.1, 2.5) and daily egg mass (53.9 g, 54.4 g, 52.8 g) data from AV, CC, and BR were not influenced significantly by the respective raising systems. Daily feed intake of layers in both AV (124 g) and BR (127 g) tended to be higher than that in CC (113 g) during phase-2. Overall, exterior egg quality (dirty and cracked eggs) in both phases was superior in BR compared with AV and CC, whereas CC generated intermediate results. This study indicated that the HDEP per se in AV and BR were not significantly different from that in CC. The study implied that the facility depreciation cost for AV and cost for increased feed intake in AV compared to CC are believed to be critical to evaluate the cost effectiveness of egg production in AV. PMID:25083115

  1. Mouse lung inflammation after instillation of particulate matter collected from a working dairy barn

    International Nuclear Information System (INIS)

    Coarse and fine particulate matter (PM2.5-10 and PM2.5, respectively) are regulated ambient air pollutants thought to have major adverse health effects in exposed humans. The role of endotoxin and other bioaerosol components in the toxicity of PM from ambient air is controversial. This study evaluated the inflammatory lung response in mice instilled intratracheally with PM2.5-10 and PM2.5 emitted from a working dairy barn, a source presumed to have elevated concentrations of endotoxin. PM2.5-10 was more pro-inflammatory on an equal weight basis than was PM2.5; both fractions elicited a predominantly neutrophilic response. The inflammatory response was reversible, with a peak response to PM2.5-10 observed at 24 h after instillation, and a return to control values by 72 h after instillation. The major active pro-inflammatory component in whole PM2.5-10, but not in whole PM2.5, is heat-labile, consistent with it being endotoxin. A heat treatment protocol for the gradual inactivation of biological materials in the PM fractions over a measurable time course was developed and optimized in this study using pure lipopolysaccharide (LPS) as a model system. The time course of heat inactivation of pure LPS and of endotoxin activity in PM2.5-10 as measured by Limulus bioassay is identical. The active material in both PM2.5-10 and PM2.5 remained in the insoluble fraction when the whole PM samples were extracted with physiological saline solution. Histological analysis of lung sections from mice instilled with PM2.5-10 or PM2.5 showed evidence of inflammation consistent with the cellular responses observed in lung lavage fluid. The major pro-inflammatory components present in endotoxin-rich PM were found in the insoluble fraction of PM2.5-10; however, in contrast with PM2.5-10 isolated from ambient air in the Central Valley of California, the active components in the insoluble fraction were heat-labile.

  2. Cooling systems of the resting area in free stall dairy barn.

    Science.gov (United States)

    Calegari, F; Calamari, L; Frazzi, E

    2016-04-01

    A study during the summer season evaluated the effect of different cooling systems on behavioral and productive responses of Italian Friesian dairy cows kept in an experimental-free stall barn located in the Po Valley in Italy. The study involved 30 lactating dairy cows subdivided into two groups kept in two pens with external hard court paddock in each free stall. The same cooling system was applied in the feeding area in both pens. A different cooling system in the resting area was applied to the two pens: in the pen SW, the resting area was equipped with fans and misters; in the other, there was simple ventilation (SV). Breathing rate, rectal temperature, milk yield, and milk characteristics (fat, protein, and somatic cell count) were measured. Behavioral activities (standing and lying cows in the different areas, as well as the animals in the feed bunk) were recorded. Mild to moderate heat waves during the trial were observed. On average, the breathing rate was numerically greater in SV compared with SW cows (60.2 and 55.8 breath/min, respectively), and mean rectal temperature remained below 39 °C in both groups during the trial (on average 38.7 and 38.8 °C in SV and SW, respectively. During the hotter periods of the trial, the time spent lying indoor in the free stall was greater in SW (11.8 h/day) than SV (10.7 h/day). Conversely, the time spent standing indoor without feeding was greater in SV (4.3 h/day) than SW (3.8 h/day). Milk yield was slightly better maintained during hotter period in SW compared with SV and somatic cell count was also slightly greater in the former. In conclusion, the adoption of the cooling system by means of evaporative cooling also in the resting area reduces the alteration of time budget caused by heat stress. PMID:26335294

  3. Compact Reactor

    International Nuclear Information System (INIS)

    Weyl's Gauge Principle of 1929 has been used to establish Weyl's Quantum Principle (WQP) that requires that the Weyl scale factor should be unity. It has been shown that the WQP requires the following: quantum mechanics must be used to determine system states; the electrostatic potential must be non-singular and quantified; interactions between particles with different electric charges (i.e. electron and proton) do not obey Newton's Third Law at sub-nuclear separations, and nuclear particles may be much different than expected using the standard model. The above WQP requirements lead to a potential fusion reactor wherein deuterium nuclei are preferentially fused into helium nuclei. Because the deuterium nuclei are preferentially fused into helium nuclei at temperatures and energies lower than specified by the standard model there is no harmful radiation as a byproduct of this fusion process. Therefore, a reactor using this reaction does not need any shielding to contain such radiation. The energy released from each reaction and the absence of shielding makes the deuterium-plus-deuterium-to-helium (DDH) reactor very compact when compared to other reactors, both fission and fusion types. Moreover, the potential energy output per reactor weight and the absence of harmful radiation makes the DDH reactor an ideal candidate for space power. The logic is summarized by which the WQP requires the above conditions that make the prediction of DDH possible. The details of the DDH reaction will be presented along with the specifics of why the DDH reactor may be made to cause two deuterium nuclei to preferentially fuse to a helium nucleus. The presentation will also indicate the calculations needed to predict the reactor temperature as a function of fuel loading, reactor size, and desired output and will include the progress achieved to date

  4. Study of $ \\bar{p} $ and $ \\bar{n} $ annihilations at LEAR with OBELIX, a large acceptance and high resolution detector based on the Open Axial Field Spectrometer

    CERN Multimedia

    2002-01-01

    % PS201 Study of $\\bar{p}$ and $\\bar{n}$ annihilations at LEAR with OBELIX, a large acceptance and high resolution detector based on the Open Axial Field Spectrometer \\\\ \\\\OBELIX is designed to study exclusive final states of antiproton and antineutron annihilations at low energies with protons and nuclei. \\\\ \\\\The physics motivations of the experiment are:\\\\ \\\\\\begin{itemize} \\item (gg, ggg), hybrids ($ q \\bar{q} g $), multiquarks ($ q q \\bar{q} \\bar{q} $) and light mesons ($ q \\bar{q} $) produced in $ N \\bar{N} $ annihilations and study of their spectroscopy and decays. Also broad structures will be searched for by comparing identical decay modes in exclusive final states of the same type occuring from initial states with different angular momentum or isospin. \\item Study of the dynamics of $ N \\bar{N} $ interactions and of the dependence of the final and intermediate resonant states of annihilation upon the quantum numbers of the initial $ N \\bar{N} $ state (angular momentum: S and P-wave in $\\bar{p}p $ at...

  5. Tests of the Aversive Summation Hypothesis in Rats: Effects of Restraint Stress on Consummatory Successive Negative Contrast and Extinction in the Barnes Maze

    Science.gov (United States)

    Ortega, Leonardo A.; Prado-Rivera, Mayerli A.; Cardenas-Poveda, D. Carolina; McLinden, Kristina A.; Glueck, Amanda C.; Gutierrez, German; Lamprea, Marisol R.; Papini, Mauricio R.

    2013-01-01

    The present research explored the effects of restraint stress on two situations involving incentive downshift: consummatory successive negative contrast (cSNC) and extinction of escape behavior in the Barnes maze. First, Experiment 1 confirmed that the restraint stress procedure used in these experiments increased levels of circulating…

  6. A study of KK-bar system produced in the reaction Π-p#-> #KK-barn at 63 GeV

    International Nuclear Information System (INIS)

    An analysis of KK-bar system produced in the reaction Π-p#-> #KK-barn at 63 GeV and measured by ACCMOR (Amsterdam-CERN-Cracow-Munich-Oxford-Rutherford) collaboration at the CERN SPS accelelator is presented. (author)

  7. NEUTRONIC REACTOR

    Science.gov (United States)

    Anderson, H.L.

    1960-09-20

    A nuclear reactor is described comprising fissionable material dispersed in graphite blocks, helium filling the voids of the blocks and the spaces therebetween, and means other than the helium in thermal conductive contact with the graphite for removing heat.

  8. NUCLEAR REACTOR

    Science.gov (United States)

    Miller, H.I.; Smith, R.C.

    1958-01-21

    This patent relates to nuclear reactors of the type which use a liquid fuel, such as a solution of uranyl sulfate in ordinary water which acts as the moderator. The reactor is comprised of a spherical vessel having a diameter of about 12 inches substantially surrounded by a reflector of beryllium oxide. Conventionnl control rods and safety rods are operated in slots in the reflector outside the vessel to control the operation of the reactor. An additional means for increasing the safety factor of the reactor by raising the ratio of delayed neutrons to prompt neutrons, is provided and consists of a soluble sulfate salt of beryllium dissolved in the liquid fuel in the proper proportion to obtain the result desired.

  9. Nuclear reactors

    International Nuclear Information System (INIS)

    This draft chart contains graphical symbols from which the type of (nuclear) reactor can be seen. They will serve as illustrations for graphical sketches. Important features of the individual reactor types are marked out graphically. The user can combine these symbols to characterize a specific reactor type. The basic graphical symbol is a square with a point in the centre. Functional groups can be depicted for closer specification. If two functional groups are not clearly separated, this is symbolized by a dotted line or a channel. Supply and discharge lines for coolant, moderator and fuel are specified in accordance with DIN 2481 and can be further specified by additional symbols if necessary. The examples in the paper show several different reactor types. (orig./AK)

  10. Multifunctional reactors

    OpenAIRE

    Westerterp, K.R.

    1992-01-01

    Multifunctional reactors are single pieces of equipment in which, besides the reaction, other functions are carried out simultaneously. The other functions can be a heat, mass or momentum transfer operation and even another reaction. Multifunctional reactors are not new, but they have received much emphasis in research in the last decade. A survey is given of modern developments and the first successful applications on a large scale. It is explained why their application in many instances is ...

  11. NUCLEAR REACTOR

    Science.gov (United States)

    Anderson, C.R.

    1962-07-24

    A fluidized bed nuclear reactor and a method of operating such a reactor are described. In the design means are provided for flowing a liquid moderator upwardly through the center of a bed of pellets of a nentron-fissionable material at such a rate as to obtain particulate fluidization while constraining the lower pontion of the bed into a conical shape. A smooth circulation of particles rising in the center and falling at the outside of the bed is thereby established. (AEC)

  12. Nuclear reactor

    International Nuclear Information System (INIS)

    In order to reduce neutron embrittlement of the pressue vessel of an LWR, blanked off elements are fitted at the edge of the reactor core, with the same dimensions as the fuel elements. They are parallel to each other, and to the edge of the reactor taking the place of fuel rods, and are plates of neutron-absorbing material (stainless steel, boron steel, borated Al). (HP)

  13. Breeder reactors

    International Nuclear Information System (INIS)

    The reasons for the development of fast reactors are briefly reviewed (a propitious neutron balance oriented towards a maximum uranium burnup) and its special requirements (cooling, fissile material density and reprocessing) discussed. The three stages in the French program of fast reactor development are outlined with Rapsodie at Cadarache, Phenix at Marcoule, and Super Phenix at Creys-Malville. The more specific features of the program of research and development are emphasized: kinetics and the core, the fuel and the components

  14. Research reactors - an overview

    Energy Technology Data Exchange (ETDEWEB)

    West, C.D.

    1997-03-01

    A broad overview of different types of research and type reactors is provided in this paper. Reactor designs and operating conditions are briefly described for four reactors. The reactor types described include swimming pool reactors, the High Flux Isotope Reactor, the Mark I TRIGA reactor, and the Advanced Neutron Source reactor. Emphasis in the descriptions is placed on safety-related features of the reactors. 7 refs., 7 figs., 2 tabs.

  15. Sex-related effects of an immune challenge on growth and begging behavior of barn swallow nestlings.

    Directory of Open Access Journals (Sweden)

    Andrea Romano

    Full Text Available Parent-offspring conflicts lead the offspring to evolve reliable signals of individual quality, including parasite burden, which may allow parents to adaptively modulate investment in the progeny. Sex-related variation in offspring reproductive value, however, may entail differential investment in sons and daughters. Here, we experimentally manipulated offspring condition in the barn swallow (Hirundo rustica by subjecting nestlings to an immune challenge (injection with bacterial lipopolysaccharide, LPS that simulates a bacterial infection, and assessed the effects on growth, feather quality, expression of morphological (gape coloration and behavioral (posture begging displays involved in parent-offspring communication, as well as on food allocation by parents. Compared to sham-injected controls, LPS-treated chicks suffered a depression of body mass and a reduction of palate color saturation. In addition, LPS treatment resulted in lower feather quality, with an increase in the occurrence of fault bars on wing feathers. The color of beak flanges, feather growth and the intensity of postural begging were affected by LPS treatment only in females, suggesting that chicks of either sex are differently susceptible to the immune challenge. However, irrespective of the effects of LPS, parents equally allocated food among control and challenged offspring both under normal food provisioning and after a short period of food deprivation of the chicks. These results indicate that bacterial infection and the associated immune response entail different costs to offspring of either sex, but a decrease in nestling conditions does not affect parental care allocation, possibly because the barn swallow adopts a brood-survival strategy. Finally, we showed that physiological stress induced by pathogens impairs plumage quality, a previously neglected major negative impact of bacterial infection which could severely affect fitness, particularly among long

  16. Reactor utilization

    International Nuclear Information System (INIS)

    In 1962, the RA reactor was operated almost three times more than in 1961, producing total of 25 555 MWh. Diagram containing comparative data about reactor operation for 1960, 1961, and 1962, percent of fuel used and U-235 burnup shows increase in reactor operation. Number of samples irradiated was 659, number of experiments done was 16. mean powered level was 5.93 MW. Fuel was added into the core twice during the reporting year. In fact the core was increased from 56 to 68 fuel channels and later to 84 fuel channels. Fuel was added to the core when the reactivity worth decreased to the minimum operation level due to burnup. In addition to this 5 central fuel channels were exchanged with fresh fuel in february for the purpose of irradiation in the VISA-2 channel

  17. Reactor Neutrinos

    CERN Document Server

    Lasserre, T; Lasserre, Thierry; Sobel, Henry W.

    2005-01-01

    We review the status and the results of reactor neutrino experiments, that toe the cutting edge of neutrino research. Short baseline experiments have provided the measurement of the reactor neutrino spectrum, and are still searching for important phenomena such as the neutrino magnetic moment. They could open the door to the measurement of coherent neutrino scattering in a near future. Middle and long baseline oscillation experiments at Chooz and KamLAND have played a relevant role in neutrino oscillation physics in the last years. It is now widely accepted that a new middle baseline disappearance reactor neutrino experiment with multiple detectors could provide a clean measurement of the last undetermined neutrino mixing angle theta13. We conclude by opening on possible use of neutrinos for Society: NonProliferation of Nuclear materials and Geophysics.

  18. Nuclear reactors

    International Nuclear Information System (INIS)

    A nuclear reactor has a large prompt negative temperature coefficient of reactivity. A reactor core assembly of a plurality of fluid-tight fuel elements is located within a water-filled tank. Each fuel element contains a solid homogeneous mixture of 50-79 w/o zirconium hydride, 20-50 w/o uranium and 0.5-1.5 W erbium. The uranium is not more than 20 percent enriched, and the ratio of hydrogen atoms to zirconium atoms is between 1.5:1 and 7:1. The core has a long lifetime, E.G., at least about 1200 days

  19. Nuclear reactors

    International Nuclear Information System (INIS)

    In a liquid cooled nuclear reactor, the combination is described for a single-walled vessel containing liquid coolant in which the reactor core is submerged, and a containment structure, primarily of material for shielding against radioactivity, surrounding at least the liquid-containing part of the vessel with clearance therebetween and having that surface thereof which faces the vessel make compatible with the liquid, thereby providing a leak jacket for the vessel. The structure is preferably a metal-lined concrete vault, and cooling means are provided for protecting the concrete against reaching a temperature at which damage would occur. (U.S.)

  20. Nuclear reactor

    International Nuclear Information System (INIS)

    In an improved reactor core for a high conversion BWR reactor, Pu-breeding type BWR type reactor, Pu-breeding type BWR type rector, FEBR type reactor, etc., two types of fuel assemblies are loaded such that fuel assemblies using a channel box of a smaller irradiation deformation ratio are loaded in a high conversion region, while other fuel assemblies are loaded in a burner region. This enables to suppress the irradiation deformation within an allowable limit in the high conversion region where the fast neutron flux is high and the load weight from the inside of the channel box due to the pressure loss is large. At the same time, the irradiation deformation can be restricted within an allowable limit without deteriorating the neutron economy in the burner region in which fast neutron flux is low and the load weight from the inside of the channel box is small since a channel box with smaller neutron absorption cross section or reduced wall thickness is charged. As a result, it is possible to prevent structural deformations such as swelling of the channel box, bending of the entire assemblies, bending of fuel rods, etc. (K.M.)

  1. The effect of production system (barn and free-range), slaughtering age and gender on carcass traits and meat quality of partridges (Alectoris chukar).

    Science.gov (United States)

    Yamak, U S; Sarica, M; Boz, M A; Ucar, A

    2016-04-01

    1. A total of 400 Alectoris chukar partridges were reared in either barn or free-range production systems and slaughtered at 14, 16 or 18 weeks of age in order to determine the effects of production system, age and gender on carcass traits (live weight, carcass weight, carcass yield, carcass part and edible inner organ percentages at slaughtering) and meat quality (L*, a* and b* meat colour and pH). 2. Production system had a significant effect on both slaughter traits and meat quality. 3. Partridges raised in barn conditions had higher live weights and carcass weights whereas meat quality was better in birds raised in the free-range system. PMID:26813778

  2. Phylogenetic systematics of Barn Owl (Tyto alba (Scopoli, 1769 complex inferred from mitochondrial rDNA (16S rRNA taxonomic implication

    Directory of Open Access Journals (Sweden)

    Mansour Aliabadian

    2012-09-01

    Full Text Available The Barn owl, Tyto alba (Scopoli, 1769, occurs worldwide and shows a considerable amount of morphological and geographical variations, leading to the recognition of many subspecies throughout the world. Yet, no comprehensive study has not been done on this species. Data from mitochondrial gene (16S Ribosomal RNA (16S with 569 bp length were analyzed for 41 individuals around the world. Maximum likelihood (ML, maximum parsimony (MP and Bayesian analysis showed two distinct clades including alba clad (old world and furcata clad (new world. The amount of genetic variation within each of these clades ranged from 0.5-1.7 but variation between clades was 3.7. This data may suggest that Barn owls of the Old World may be a separate species from those of the New World.

  3. Barns Uppfattningar om Stjärnorna och Solen : En undersökning med 4-5-åringar

    OpenAIRE

    Böröy, Marie

    2013-01-01

    Denna studie visar vad 4-5-åringar har för uppfattningar om stjärnorna och solen, vad de tror att stjärnorna och solen är för något och vad de har för tankar om fenomen kring dem. Genomförandet av studien bygger på kvalitativa intervjuer i samband med att barnen målar. Metoden har gjort det möjligt för barnen att uttrycka sina egna tankar. Resultatet visar att det finns många uppfattningar inom området hos barn 4-5 år. En del uppfattningar är realistiska, en del fiktiva. Ett barn förklarar at...

  4. "Låt barnens språk mogna" : - En kvalitativ undersökning om daghems arbetssätt med barns språk

    OpenAIRE

    Nyman, Petra; Byman, Maria

    2010-01-01

    Detta examensarbete undersöker barnträdgårdslärares arbetssätt angående barns språk. Syftet med arbetet är att ta reda på hur daghemspersonalen (barnträdgårdslärare) jobbar för att stöda och stimulera barns språkliga utveckling samt vilka arbetsmetoder används för detta ändamål. Syftet har även varit att ta reda på om kommunens läroplan för daghemmen angående språk och kommunikation används på det sätt som avsetts. Teorin som vi använt oss av behandlar språkstimulans, uppväxtmiljöns betydelse...

  5. Effects of hatching asynchrony on sibling negotiation, begging, jostling for position and within-brood food allocation in the barn owl Tyto alba

    OpenAIRE

    Roulin A.

    2004-01-01

    When siblings differ markedly in their need for food, they may benefit from signalling to each other their willingness to contest the next indivisible food item delivered by the parents. This sib-sib communication system, referred to as 'sibling negotiation', may allow them to adjust optimally to investment in begging. Using barn owl (Two alba) broods. I assessed the role of within-brood age hierarchy on sibling negotiation, and in turn on jostling for position where parents predictably deliv...

  6. SETTINGS IN THE NOVELS OF JULIAN BARNES (With Reference to Talking It Over, The Porcupine, England, England, Love, etc., Arthur & George)

    OpenAIRE

    Gajanan N. Katkar

    2013-01-01

    Julian Barnes was born in Leicester, England's East midland, on January 19, 1946 in the family of a teacher. His father, Albert taught French at st. Clement Danes from 1937 onwards till his retirement in 1971. His mother, Keye, also taught French. His elder brother, Jonathan is now a Professor of Philosophy in Geneva. He married Pat Kavanagh in 1979, and now lives with her in North London.

  7. Impact of in-barn manure separation on biological air quality in an experimental setup identical to that in swine buildings.

    Science.gov (United States)

    Lavoie, J; Godbout, S; Lemay, S P; Belzile, M

    2009-07-01

    In-barn manure separation systems are becoming popular due to various environmental pressures on the swine industry. According to the literature, separation of feces and urine directly underneath the slats should have a positive impact on barn air quality. Removal and rapid separation of the two phases (solid/liquid) would reduce the dust and bioaerosol emissions, which would significantly improve the air quality in pig-housing facilities. From an occupational health and safety perspective, the maximum endotoxin and total bacteria concentrations to ensure workers' safety should not exceed 450 endotoxin units per cubic meter of air (EU m(-3)) and 10(4) colony-forming units per cubic meter of air (CFU m(-3)), respectively. In the current study, the effect on air quality of six in-barn manure handling systems was measured. A flat scraper system and four separation systems installed under the slats (a conveyor belt system, a conveyor net system, and a V-shaped scraper operated at two operation frequencies) were evaluated and compared to a conventional pull-plug system (control). The experiment took place in twelve independent and identical rooms housing four grower-finisher pigs each, and air samples were collected and analyzed for total dust, endotoxins, bacteria, and mold counts. The results obtained from this experimental setup show that the separation of feces and urine under the slats would concentrate at least 80% of the phosphorus in the solid phase. The total bacteria and endotoxin concentrations are lower than those found in commercial hog barns but remain higher than the recommended levels. Only the total dust concentrations are approximately 10% of their regulated value. This separation has no impact on dust and bioaerosol concentrations compared to the control. PMID:19728546

  8. Divorce in the barn owl: securing a compatible or better mate entails the cost of re-pairing with a less ornamented female mate.

    OpenAIRE

    Dreiss A.N.; Roulin A.

    2014-01-01

    Two nonmutually exclusive hypotheses can explain why divorce is an adaptive strategy to improve reproductive success. Under the 'better option hypothesis', only one of the two partners initiates divorce to secure a higher-quality partner and increases reproductive success after divorce. Under the 'incompatibility hypothesis', partners are incompatible and hence they may both increase reproductive success after divorce. In a long-term study of the barn owl (Tyto alba), we address the question ...

  9. Increased rodenticide exposure rate and risk of toxicosis in barn owls (Tyto alba) from southwestern Canada and linkage with demographic but not genetic factors.

    Science.gov (United States)

    Huang, Andrew C; Elliott, John E; Hindmarch, Sofi; Lee, Sandi L; Maisonneuve, France; Bowes, Victoria; Cheng, Kimberly M; Martin, Kathy

    2016-08-01

    Among many anthropogenic drivers of population decline, continual rapid urbanization and industrialization pose major challenges for the survival of wildlife species. Barn owls (Tyto alba) in southwestern British Columbia (BC) face a multitude of threats ranging from habitat fragmentation to vehicle strikes. They are also at risk from secondary poisoning of second-generation anticoagulant rodenticides (SGARs), a suite of toxic compounds which at high doses results in a depletion of blood clotting factors leading to internal bleeding and death. Here, using long-term data (N = 119) for the hepatic residue levels of SGAR, we assessed the risk of toxicosis from SGAR for the BC barn owl population over the past two decades. We also investigated whether sensitivity to SGAR is associated with genetic factors, namely Single Nucleotide Polymorphisms (SNPs) found in the CYP2C45 gene of barn owls. We found that residue concentration for total SGAR was significantly higher in 2006-2013 (141 ng/g) relative to 1992-2003 (57 ng/g). The proportion of owls exposed to multiple SGAR types was also significantly higher in 2006-2013. Those measures accordingly translate directly into an increase in toxicosis risk level. We also detected demographic differences, where adult females showed on average lower concentration of total SGAR (64 ng/g) when compared to adult males (106 ng/g). Juveniles were overall more likely to show signs of toxicosis than adults (33.3 and 6.9 %, respectively), and those symptoms were positively predicted by SGAR concentrations. We found no evidence that SNPs in the CYP2C45 gene of barn owls were associated with intraspecific variation in SGAR sensitivity. We recommend several preventative measures be taken to minimize wildlife exposure to SGAR. PMID:27151403

  10. Behavioral responses to frequency specific head related transfer functions as filtered by the facial ruff in the Barn owl (Tyto alba)

    OpenAIRE

    Hausmann, Elena Laura

    2010-01-01

    The barn owl is, due to its numerous morphological and neuronal adaptations to sound localization, a long-established model animal for the auditory system. Besides extensive research on the topic within the last decades, it is still unclear how direction- and frequency-dependent physical cues (interaural time differences (ITDs), level differences (ILDs) and monaural spectra) contribute to sound localization especially in the elevational plane. A further open question is to what extent frequen...

  11. The automorphism group of the Z_2-orbifold of the Barnes-Wall lattice vertex operator algebra of central charge 32

    OpenAIRE

    Shimakura, Hiroki

    2013-01-01

    In this article, we prove that the full automorphism group of the Z_2-orbifold of the Barnes-Wall lattice vertex operator algebra of central charge 32 has the shape $2^{27}.E_6(2)$. In order to identify the group structure, we introduce a graph structure on the Griess algebra and show that it is a rank 3 graph associated to $E_6(2)$.

  12. Reactor container

    International Nuclear Information System (INIS)

    A reactor container has a suppression chamber partitioned by concrete side walls, a reactor pedestal and a diaphragm floor. A plurality of partitioning walls are disposed in circumferential direction each at an interval inside the suppression chamber, so that independent chambers in a state being divided into plurality are formed inside the suppression chamber. The partition walls are formed from the bottom portion of the suppression chamber up to the diaphragm floor to isolate pool water in a divided state. Operation platforms are formed above the suppression chamber and connected to an access port. Upon conducting maintenance, inspection or repairing, a pump is disposed in the independent chamber to transfer pool water therein to one or a plurality of other independent chambers to make it vacant. (I.N.)

  13. Reactor building

    International Nuclear Information System (INIS)

    The present invention concerns a structure of ABWR-type reactor buildings, which can increase the capacity of a spent fuel storage area at a low cost and improved earthquake proofness. In the reactor building, the floor of a spent fuel pool is made flat, and a depth of the pool water satisfying requirement for shielding is ensured. In addition, a depth of pool water is also maintained for a equipment provisionally storing pool for storing spent fuels, and a capacity for a spent fuel storage area is increased by utilizing surplus space of the equipment provisionally storing pool. Since the flattened floor of the spent fuel pool is flushed with the floor of the equipment provisionally storing pool, transfer of horizontal loads applied to the building upon occurrence of earthquakes is made smooth, to improve earthquake proofness of the building. (T.M.)

  14. Nuclear reactors

    International Nuclear Information System (INIS)

    Disclosed is a nuclear reactor cooled by a freezable liquid has a vessel for containing said liquid and comprising a structure shaped as a container, and cooling means in the region of the surface of said structure for effecting freezing of said liquid coolant at and for a finite distance from said surface for providing a layer of frozen coolant on and supported by said surface for containing said liquid coolant. In a specific example, where the reactor is sodium-cooled, the said structure is a metal-lined concrete vault, cooling is effected by closed cooling loops containing NaK, the loops extending over the lined surface of the concrete vault with outward and reverse pipe runs of each loop separated by thermal insulation, and air is flowed through cooling pipes embedded in the concrete behind the metal lining. 7 claims, 3 figures

  15. Genetic divergence analysis of the Common Barn Owl Tyto alba (Scopoli, 1769) and the Short-eared Owl Asio flammeus (Pontoppidan, 1763) from southern Chile using COI sequence

    Science.gov (United States)

    Colihueque, Nelson; Gantz, Alberto; Rau, Jaime Ricardo; Parraguez, Margarita

    2015-01-01

    Abstract In this paper new mitochondrial COI sequences of Common Barn Owl Tyto alba (Scopoli, 1769) and Short-eared Owl Asio flammeus (Pontoppidan, 1763) from southern Chile are reported and compared with sequences from other parts of the World. The intraspecific genetic divergence (mean p-distance) was 4.6 to 5.5% for the Common Barn Owl in comparison with specimens from northern Europe and Australasia and 3.1% for the Short-eared Owl with respect to samples from north America, northern Europe and northern Asia. Phylogenetic analyses revealed three distinctive groups for the Common Barn Owl: (i) South America (Chile and Argentina) plus Central and North America, (ii) northern Europe and (iii) Australasia, and two distinctive groups for the Short-eared Owl: (i) South America (Chile and Argentina) and (ii) north America plus northern Europe and northern Asia. The level of genetic divergence observed in both species exceeds the upper limit of intraspecific comparisons reported previously for Strigiformes. Therefore, this suggests that further research is needed to assess the taxonomic status, particularly for the Chilean populations that, to date, have been identified as belonging to these species through traditional taxonomy. PMID:26668551

  16. Low variation in the polymorphic Clock gene poly-Q region despite population genetic structure across barn swallow (Hirundo rustica populations.

    Directory of Open Access Journals (Sweden)

    Roi Dor

    Full Text Available Recent studies of several species have reported a latitudinal cline in the circadian clock gene, Clock, which influences rhythms in both physiology and behavior. Latitudinal variation in this gene may hence reflect local adaptation to seasonal variation. In some bird populations, there is also an among-individual association between Clock poly-Q genotype and clutch initiation date and incubation period. We examined Clock poly-Q allele variation in the Barn Swallow (Hirundo rustica, a species with a cosmopolitan geographic distribution and considerable variation in life-history traits that may be influenced by the circadian clock. We genotyped Barn Swallows from five populations (from three subspecies and compared variation at the Clock locus to that at microsatellite loci and mitochondrial DNA (mtDNA. We found very low variation in the Clock poly-Q region, as >96% of individuals were homozygous, and the two other alleles at this locus were globally rare. Genetic differentiation based on the Clock poly-Q locus was not correlated with genetic differentiation based on either microsatellite loci or mtDNA sequences. Our results show that high diversity in Clock poly-Q is not general across avian species. The low Clock variation in the background of heterogeneity in microsatellite and mtDNA loci in Barn Swallows may be an outcome of stabilizing selection on the Clock locus.

  17. Low Variation in the Polymorphic Clock Gene Poly-Q Region Despite Population Genetic Structure across Barn Swallow (Hirundo rustica) Populations

    Science.gov (United States)

    Dor, Roi; Lovette, Irby J.; Safran, Rebecca J.; Billerman, Shawn M.; Huber, Gernot H.; Vortman, Yoni; Lotem, Arnon; McGowan, Andrew; Evans, Matthew R.; Cooper, Caren B.; Winkler, David W.

    2011-01-01

    Recent studies of several species have reported a latitudinal cline in the circadian clock gene, Clock, which influences rhythms in both physiology and behavior. Latitudinal variation in this gene may hence reflect local adaptation to seasonal variation. In some bird populations, there is also an among-individual association between Clock poly-Q genotype and clutch initiation date and incubation period. We examined Clock poly-Q allele variation in the Barn Swallow (Hirundo rustica), a species with a cosmopolitan geographic distribution and considerable variation in life-history traits that may be influenced by the circadian clock. We genotyped Barn Swallows from five populations (from three subspecies) and compared variation at the Clock locus to that at microsatellite loci and mitochondrial DNA (mtDNA). We found very low variation in the Clock poly-Q region, as >96% of individuals were homozygous, and the two other alleles at this locus were globally rare. Genetic differentiation based on the Clock poly-Q locus was not correlated with genetic differentiation based on either microsatellite loci or mtDNA sequences. Our results show that high diversity in Clock poly-Q is not general across avian species. The low Clock variation in the background of heterogeneity in microsatellite and mtDNA loci in Barn Swallows may be an outcome of stabilizing selection on the Clock locus. PMID:22216124

  18. NEUTRONIC REACTORS

    Science.gov (United States)

    Anderson, J.B.

    1960-01-01

    A reactor is described which comprises a tank, a plurality of coaxial steel sleeves in the tank, a mass of water in the tank, and wire grids in abutting relationship within a plurality of elongated parallel channels within the steel sleeves, the wire being provided with a plurality of bends in the same plane forming adjacent parallel sections between bends, and the sections of adjacent grids being normally disposed relative to each other.

  19. Nuclear reactor

    International Nuclear Information System (INIS)

    The liquid metal (sodium) cooled fast breeder reactor has got fuel subassemblies which are bundled and enclosed by a common can. In order to reduce bending of the sides of the can because of the load caused by the coolant pressure the can has got a dodecagon-shaped crosssection. The surfaces of the can may be of equal width. One out of two surfaces may also be convex towards the center. (RW)

  20. Nuclear reactor

    International Nuclear Information System (INIS)

    A detector having high sensitivity to fast neutrons and having low sensitivity to thermal neutrons is disposed for reducing influences of neutron detector signals on detection values of neutron fluxes when the upper end of control rod pass in the vicinity of the neutron flux detector. Namely, the change of the neutron fluxes is greater in the thermal neutron energy region while it is smaller in the fast neutron energy region. This is because the neutron absorbing cross section of B-10 used as neutron absorbers of control rods is greater in the thermal neutron region and it is smaller in the fast neutron region. As a result, increase of the neutron detection signals along with the local neutron flux change can be reduced, and detection signals corresponding to the reactor power can be obtained. Even when gang withdrawal of operating a plurality of control rods at the same time is performed, the reactor operation cycle can be measured accurately, thereby enabling to shorten the reactor startup time. (N.H.)

  1. Sex-related effects of reproduction on biomarkers of oxidative damage in free-living barn swallows (Hirundo rustica.

    Directory of Open Access Journals (Sweden)

    Diego Rubolini

    Full Text Available According to life-history theory, the allocation of limiting resources to one trait has negative consequences for other traits requiring the same resource, resulting in trade-offs among life-history traits, such as reproduction and survival. In vertebrates, oxidative stress is increasingly being considered among the physiological mechanisms forming the currency of life-history trade-offs. In this study of the barn swallow (Hirundo rustica, we focus on the oxidative costs of reproduction, especially egg laying, by investigating the effects of breeding stage (pre- vs. post-laying and progression of the season on three biomarkers of oxidative damage (OD to plasma proteins, namely the concentration of malondialdehyde (MDA-protein adducts and of protein thiol groups (PSH, and the protein carbonyl (PCO content. Moreover, we investigated whether males and females differed in plasma OD levels, because the inherent sex differences in reproductive roles and physiology may originate sex-specific patterns of OD during breeding. We found that MDA-protein adduct levels were higher in the pre-laying than in the post-laying phase, that males had lower levels of MDA-modified proteins than females, and that the decline of MDA-protein adduct concentration between the pre- and the post-laying phase was more marked for females than males. In addition, MDA-protein adduct levels declined with sampling date, but only during the pre-laying phase. On the other hand, plasma PCO levels increased from the pre- to the post-laying phase in both sexes, and females had higher levels of PCO than males. PSH concentration was unaffected by breeding stage, sex or sampling date. On the whole, our findings indicate that biomarkers of protein oxidation closely track the short-term variation in breeding stage of both male and female barn swallows. Moreover, the higher protein OD levels observed among females compared to males suggest that egg laying entails oxidative costs, which might

  2. 天然气水暖集中供热密集烤房设备的研究%Study on the bulk curing barn with central water heating by natural gas

    Institute of Scientific and Technical Information of China (English)

    任杰; 孙福山; 刘治清; 徐世峰; 许建设; 沈始权

    2013-01-01

      针对我国烟叶烘烤设备对煤炭依赖度高、环境污染重、烘烤用工量大的问题,利用液化天然气(LNG)为气源,集成LNG 气化技术、水暖集中供热技术,设计建造了天然气水暖集中供热密集烤房,并进行了烘烤试验。结果表明:天然气水暖集中供热密集烤房升温准,控温稳,能够满足烤烟密集烘烤对温湿度的要求。虽然较燃煤密集烤房能耗成本有所增加,但改善了烤后烟叶的外观质量,提高了上等烟比例,减少了烘烤用工和大气污染物排放量。%In order to resolve the problems of the bulk curing barn which depended on coal, contaminated environment and needed much labor, the bulk curing barn with central water heating by natural gas (gas fired bulk curing barn) utilizing liquefied natural gas as gas source was designed and built using liquefied natural gas gasification technique and central water heating supply technique. Effects of the bulk curing barn with central water heating by natural gas were investigated. The results indicated that heating-up of the gas fired bulk curing barn was very quick and sensitive to meet the temperature and humidity requirements of tobacco flue-curing. The gas fired bulk curing barn improved the surface quality of cured tobacco leaves and increased the proportion of classy cured tobacco leaves. Employment and emission amount of atmospheric pollutant of the gas fired bulk curing barn were less than that of the coal fired bulk curing barn, but the final cost of the gas fired bulk curing barn was more than that of the coal fired bulk curing barn.

  3. Reactor core of nuclear reactor

    International Nuclear Information System (INIS)

    In a BWR type nuclear reactor, the number of first fuel assemblies (uranium) loaded in a reactor core is smaller than that of second fuel assemblies (mixed oxide), the average burnup degree upon take-out of the first fuel assemblies is reduced to less than that of the second fuel assemblies, and the number of the kinds of the fuel rods constituting the first fuel assemblies is made smaller than that of the fuel rods constituting the second fuel assemblies. As a result, the variety of the plutonium enrichment degree is reduced to make the distribution of the axial enrichment degree uniform, thereby enabling to simplify the distribution of the enrichment degree. Then the number of molding fabrication steps for MOX fuel assemblies can be reduced, thereby enabling to reduce the cost for molding and fabrication. (N.H.)

  4. Continuous measurement of reticuloruminal pH values in dairy cows during the transition period from barn to pasture feeding using an indwelling wireless data transmitting unit.

    Science.gov (United States)

    Gasteiner, J; Horn, M; Steinwidder, A

    2015-04-01

    This study was performed to investigate the effect of the transition from barn feeding to pasture on the pattern of reticuloruminal pH values in 8 multiparous dairy cows. A indwelling wireless data transmitting system for pH measurement was given to 8 multiparous cows orally. Reticuloruminal pH values were measured every 600 s over a period of 42 days. After 7 days of barn feeding (period 1), all of the animals were pastured with increasing grazing times from 2 to 7 h/day over 7 days (period 2). From day 15 to day 21 (period 3), the cows spent 7 h/day on pasture. Beginning on day 22, the animals had 20 h/day access to pasture (day and night grazing). To study reticuloruminal adaptation to pasture feeding, the phase of day and night grazing was subdivided into another 3 weekly periods (periods 4-6). Despite a mild transition period from barn feeding to pasture, significant effects on reticuloruminal pH values were observed. During barn feeding, the mean reticuloruminal pH value for all of the cows was 6.44 ± 0.14, and the pH values decreased significantly (p period 2 and 3 to 6.24 ± 0.17 and 6.21 ± 0.19 respectively. During periods 4, 5 and 6, the reticuloruminal pH values increased again (pH 6.25 ± 0.22; pH 6.31 ± 0.17; pH 6.37 ± 0.16). Our results showed that the animals had significantly lowered reticuloruminal pH during the periods of feed transition from barn to pasture feeding. Despite these significant changes, the decrease was not harmful, as indicated by data of feed intake and milk production. PMID:25266568

  5. ONE YEAR STUDY OF LYING AND STANDING BEHAVIOUR OF DAIRY COWS IN A FRESTALL BARN IN ITALY

    Directory of Open Access Journals (Sweden)

    Giorgio Provolo

    2009-06-01

    Full Text Available Dairy farm buildings can have, as it is well known, a big influence on the microclimatic conditions in the cowshed. In order to examine the influence of environmental parameters on the conditions affecting animal welfare, an experimental programme was set up at a farm where anomalous behaviour of cows had been previously noted. The research was carried out in a freestall barn from June 2004 till June 2005. Part of the research involved a detailed monitoring of animal movements and a simultaneous measurement of temperature and humidity within the cowshed. The behaviour of cows has been obtained by the analysis of a recorded video and expressed through indices. A strict relationship between environmental parameters and animal movement has been confirmed by the results obtained. The proportion of animals resting in stalls during the daytime, not affected by milking or feeding, rised from 30% in hot periods to 75% in winter time. The highly significant (P<0.01 correlation obtained between environmental parameters and cow behaviour confirmed the strong influence of THI on total proportion of lying cows. However, the variation in cow behaviour when temperature values were inside the range considered optimal for cows, suggests the influence of other parameters, like direct radiation.

  6. Barnes-Evans relations for dwarfs with an application to the determination of distances to cataclysmic variables

    CERN Document Server

    Beuermann, K

    2006-01-01

    Barnes-Evans type relations provide an empirical relationship between the surface brightness of stars and their color. They are widely used for measuring the distances to stars of known radii, as the Roche-lobe filling secondaries in cataclysmic variables (CVs). The calibration of the surface brightness of field dwarfs of near-solar metalicity with spectral types A0 to L8 covers all secondary spectral types detectable in CVs and related objects and will aid in the measurement of their distances. The calibrations are based on the radii of field dwarfs measured by the Infrared Flux Method and by interferometry. Published photometry is used and homogenized to the Cousins Rc and Ic and the CIT JHK photometric systems. The narrow band surface brightness at 7500A is based on our own and published spectrophotometry. Care is taken to select the dwarfs for near-solar metalicity, appropriate to CVs, and to avoid errors caused by unrecognized binarity. Relations are provided for the surface brightness in V, Rc, Ic, J, H...

  7. Expression of Multiple Sexual Signals by Fathers and Sons in the East-Mediterranean Barn Swallow: Are Advertising Strategies Heritable?

    Science.gov (United States)

    Vortman, Yoni; Safran, Rebecca J.; Reiner Brodetzki, Tali; Dor, Roi; Lotem, Arnon

    2015-01-01

    The level of expression of sexually selected traits is generally determined by genes, environment and their interaction. In species that use multiple sexual signals which may be costly to produce, investing in the expression of one sexual signal may limit the expression of the other, favoring the evolution of a strategy for resource allocation among signals. As a result, even when the expression of sexual signals is condition dependent, the relative level of expression of each signal may be heritable. We tested this hypothesis in the East-Mediterranean barn swallow (Hirundo rustica transitiva), in which males have been shown to express two uncorrelated sexual signals: red-brown ventral coloration, and long tail streamers. We show that variation in both signals may partially be explained by age, as well as by paternal origin (genetic father-son regressions), but that the strongest similarity between fathers and sons is the relative allocation towards one trait or the other (relative expression index), rather than the expression of the traits themselves. These results suggest that the expression of one signal is not independent of the other, and that genetic strategies for resource allocation among sexual signals may be selected for during the evolution of multiple sexual signals. PMID:25679206

  8. Expression of multiple sexual signals by fathers and sons in the East-Mediterranean barn swallow: are advertising strategies heritable?

    Directory of Open Access Journals (Sweden)

    Yoni Vortman

    Full Text Available The level of expression of sexually selected traits is generally determined by genes, environment and their interaction. In species that use multiple sexual signals which may be costly to produce, investing in the expression of one sexual signal may limit the expression of the other, favoring the evolution of a strategy for resource allocation among signals. As a result, even when the expression of sexual signals is condition dependent, the relative level of expression of each signal may be heritable. We tested this hypothesis in the East-Mediterranean barn swallow (Hirundo rustica transitiva, in which males have been shown to express two uncorrelated sexual signals: red-brown ventral coloration, and long tail streamers. We show that variation in both signals may partially be explained by age, as well as by paternal origin (genetic father-son regressions, but that the strongest similarity between fathers and sons is the relative allocation towards one trait or the other (relative expression index, rather than the expression of the traits themselves. These results suggest that the expression of one signal is not independent of the other, and that genetic strategies for resource allocation among sexual signals may be selected for during the evolution of multiple sexual signals.

  9. Eco-geographical variation in the diet of the Barn Owl (Tyto alba in mountainous areas of France

    Directory of Open Access Journals (Sweden)

    Halliez Guillaume

    2015-12-01

    Full Text Available Because of the worldwide distribution of the Barn Owl (Tyto alba and the easily way to find its pellets, it is often used to diet studies. To investigate the eco-geographical impact of mountainous areas on its diet, we conducted studies in the Jura, Alpes, Central and Pyrénées mountains and we also did pellet analysis from 8 sites in the Jura mountains. Analysis of the tooth and skull content of pellets allowed us to draw up two types of change in the diet of Tyto alba in correlation with mountain elevation. The first one concerns the Jura, Alpes and Central mountains, where the diversity of the diet declines with the increase in elevation. The second one concerns the Pyrénées mountains, where there is no change in the diversity of the diet, perhaps because of the higher diversity of small mammals caused by mediterranean influence. Thus, it seems that elevation cau ses a decrease in diet diversity of Tyto alba in continental mountains (Jura, Alpes and Central mountains probably because of more homogeneous landscapes dedicated to grass production. However, in Mediterranean mountains (Pyrénées, a more diversified small mammal guild provides a constant level of diet diversity.

  10. Types of Nuclear Reactors

    International Nuclear Information System (INIS)

    The presentation is based on the following areas: Types of Nuclear Reactors, coolant, moderator, neutron spectrum, fuel type, pressurized water reactor (PWR), boiling water reactor (BWR) reactor pressurized heavy water (PHWR), gas-cooled reactor, RBMK , Nuclear Electricity Generation,Challenges in Nuclear Technology Deployment,EPR, APR1400, A P 1000, A PWR, ATMEA 1, VVER-1000, A PWR, VVER 1200, Boiling Water Reactor, A BWR, A BWR -II, ESBUR, Ke ren, AREVA, Heavy Water Reactor, Candu 6, Acr-1000, HWR, Bw, Iris, CAREM NuCcale, Smart, KLT-HOS, Westinghouse small modular Reactor, Gas Cooled Reactors, PBMR.

  11. Nuclear reactor

    International Nuclear Information System (INIS)

    A nuclear reactor is described in which the core components, including fuel-rod assemblies, control-rod assemblies, fertile rod-assemblies, and removable shielding assemblies, are supported by a plurality of separate inlet modular units. These units are referred to as inlet module units to distinguish them from the modules of the upper internals of the reactor. The modular units are supported, each removable independently of the others, in liners in the supporting structure for the lower internals of the reactor. The core assemblies are removably supported in integral receptacles or sockets of the modular units. The liners, units, sockets and assemblies have inlet openings for entry of the fluid. The modular units are each removably mounted in the liners with fluid seals interposed between the opening in the liner and inlet module into which the fluid enters in the upper and lower portion of the liner. Each assembly is similarly mounted in a corresponding receptacle with fluid seals interposed between the openings where the fluid enters in the lower portion of the receptacle or fitting closely in these regions. As fluid flows along each core assembly a pressure drop is produced along the fluid so that the fluid which emerges from each core assembly is at a lower pressure than the fluid which enters the core assembly. However because of the seals interposed in the mountings of the units and assemblies the pressures above and below the units and assemblies are balanced and the units are held in the liners and the assemblies are held in the receptacles by their weights as they have a higher specific gravity than the fluid. The low-pressure spaces between each module and its liner and between each core assembly and its module is vented to the low-pressure regions of the vessel to assure that fluid which leaks through the seals does not accumulate and destroy the hydraulic balance

  12. Nuclear research reactors

    International Nuclear Information System (INIS)

    It's presented data about nuclear research reactors in the world, retrieved from the Sien (Nuclear and Energetic Information System) data bank. The information are organized in table forms as follows: research reactors by countries; research reactors by type; research reactors by fuel and research reactors by purpose. (E.G.)

  13. Nuclear reactor physics course for reactor operators

    International Nuclear Information System (INIS)

    The education and training of nuclear reactor operators is important to guarantee the safe operation of present and future nuclear reactors. Therefore, a course on basic 'Nuclear reactor physics' in the initial and continuous training of reactor operators has proven to be indispensable. In most countries, such training also results from the direct request from the safety authorities to assure the high level of competence of the staff in nuclear reactors. The aim of the basic course on 'Nuclear Reactor Physics for reactor operators' is to provide the reactor operators with a basic understanding of the main concepts relevant to nuclear reactors. Seen the education level of the participants, mathematical derivations are simplified and reduced to a minimum, but not completely eliminated

  14. Nuclear reactor

    International Nuclear Information System (INIS)

    Cover gas spaces for primary coolant vessel, such as a reactor container, a pump vessel and an intermediate heat exchanger vessel are in communication with each other by an inverted U-shaped pressure conduit. A transmitter and a receiver are disposed to the pressure conduit at appropriate positions. If vibration frequencies (pressure vibration) from low frequency to high frequency are generated continuously from the transmitter to the inside of the communication pipe, a resonance phenomenon (air-column resonance oscillation) is caused by the inherent frequency or the like of the communication pipe. The frequency of the air-column resonance oscillation is changed by the inner diameter and the clogged state of the pipelines. Accordingly, by detecting the change of the air-column oscillation characteristics by the receiver, the clogged state of the flow channels in the pipelines can be detected even during the reactor operation. With such procedures, steams of coolants flowing entrained by the cover gases can be prevented from condensation and coagulation at a low temperature portion of the pipelines, otherwise it would lead clogging in the pipelines. (I.N.)

  15. A molten Salt Am242M Production Reactor for Space Applications

    Science.gov (United States)

    Emrich, William

    2005-01-01

    The use of Am242m holds great promise for increasing the efficiency nuclear thermal rocket engines. Because Am242m has the highest fission cross section of any known isotope (1000's of barns), its extremely high reactivity may be used to directly heat a propellant gas with fission fragments. Since this isotope does not occur naturally, it must be bred in special production reactors designed for that purpose. The primary advantage to using molten salt reactors for breeding Am242m is that the reactors can be reprocessed continually yielding a constant rate of production of the isotope. Once built and initially fueled, the reactor will continually breed the additional fuel it needs to remain critical. The only feedstock required is a salt of U238. No enriched fuel is required during normal operation and all fissile material, except the Am242m, is maintained in a closed loop. For a reactor operating at 200 MW several kilograms of Am242m may be bred each year.

  16. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T. (Inventor); Sahimi, Muhammad (Inventor); Fayyaz-Najafi, Babak (Inventor); Harale, Aadesh (Inventor); Park, Byoung-Gi (Inventor); Liu, Paul K. T. (Inventor)

    2011-01-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  17. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T.; Sahimi, Muhammad; Fayyaz-Najafi, Babak; Harale, Aadesh; Park, Byoung-Gi; Liu, Paul K. T.

    2011-03-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  18. Interaktionens betydelse för barns lärande - en studie av barns möte med slöjd i förskolan

    Directory of Open Access Journals (Sweden)

    Eva Ahlskog-Björkman

    2014-06-01

    Full Text Available Syftet med den här artikeln är att diskutera på vilket sätt interaktion och socialt samspel har betydelse för hur barn i förskolan kan engageras i en lärandeprocess. Den empiriska studien utgörs av en  videofilmad episod över en vävaktivitet i förskola. Genom att använda videografisk observation kan mänsklig aktivitet beskrivas och av den anledningen används  videografi som metodologisk ansats. I studien analyseras på vilket sätt interaktionen mellan de som är närvarande, oberoende av barnens ålder, kan bidra till att stimulera den lärande aktiviteten. Barnens slöjdaktivitet beaktas ur ett sociokulturellt lärandeperspektiv. Ett centralt tema inom detta perspektiv är kommunikation där språket och redskapen står för de medierande faktorerna. Barnens kontakt med redskapen och deras upplevelser och erfarande av slöjdaktiviteten diskuteras i relation till den närmaste utvecklingszonen. Ytterligare beaktas den videofilmade sekvensen ur ett socialt perspektiv där barnpedagogens agerande gentemot barnen lyfts fram och diskuteras. Analys och tolkning av datamaterialet strävar efter att synliggöra mänsklig interaktion och dess betydelse för att motivera och engagera barnen i deras slöjdaktivitet.  

  19. Reactor container

    International Nuclear Information System (INIS)

    Purpose: To prevent shocks exerted on a vent head due to pool-swell caused within a pressure suppression chamber (disposed in a torus configuration around the dry well) upon loss of coolant accident in BWR type reactors. Constitution: The following relationship is established between the volume V (m3) of a dry well and the ruptured opening area A (m2) at the boundary expected upon loss of coolant accident: V >= 30340 (m) x A Then, the volume of the dry well is made larger than the ruptured open area, that is, the steam flow rate of leaking coolants upon loss of coolant accident to decrease the pressure rise in the dry well at the initial state where loss of coolant accident is resulted. Accordingly, the pressure of non-compressive gases jetted out from the lower end of the downcomer to the pool water is decreased to suppress the pool-swell. (Ikeda, J.)

  20. Förskolegruppens påverkan på barn i behov av särskilt stöd : En intervjustudie av förskollärares erfarenheter av att tillgodose barns behov i relation till barngruppens storlek

    OpenAIRE

    Jansson, Susanna; Yousif, Emilia

    2016-01-01

    Denna studie har haft som syfte att genom en kvalitativ metod undersöka vilka möjligheter förskollärare anser sig ha i att möta barn i behov av särskilt stöd i relation till barngruppens storlek. Studiens resultat utgår från semistrukturerade intervjuer med tio förskollärare. Resultatet visar att förskollärare upplever det negativt med stora barngrupper då det försvårar arbetet att tillgodose barn i behov av särskilt stöd. Nio av tio förskollärare menar att större barngrupper leder till att f...

  1. Empirical model of odor emission from deep-pit swine finishing barns to derive a standardized odor emission factor

    Science.gov (United States)

    Schauberger, Günther; Lim, Teng-Teeh; Ni, Ji-Qin; Bundy, Dwaine S.; Haymore, Barry L.; Diehl, Claude A.; Duggirala, Ravi K.; Heber, Albert J.

    2013-02-01

    Odor emission from swine housing is influenced by the herd characteristics and building environment. The following three specific factors were identified as inputs to a swine house odor emission model: indoor temperature, barn ventilation rate, and pig activity. Model input parameters were determined based on tests of four, identical, 1000-head, mechanically-ventilated swine finishing houses. Each building had two sidewall curtains, a curtain on the west end wall, five exhaust fans on the east end wall, four pit ventilation fans, and long-term manure storage beneath a fully slatted floor. Odor concentrations of 112 odor samples were determined using dynamic forced-choice olfactometry with four to six trained panelists. The emission model showed that the standard live mass specific odor emission factor was 48 OU s-1 per 500 kg live mass or animal unit (AU), and it corresponded to an indoor temperature of T0 = 20 °C, a ventilation rate of V0 = 200 m3 h-1 (55.6 × 10-3 m3 s-1) per pig (maximum capacity for summer time), and the daily mean animal activity. The rate of odor emission from a swine finishing house can be calculated based on these parameters coupled with the number of animals, the mean live mass, and the standard live mass specific odor emission factor. Using this process-based odor emission model, the odor emission estimation and therefore the input for odor dispersion models can be improved to obtain more reliable estimates of separation distance for siting future pig farms.

  2. Measured and modelled tritium concentrations in freshwater Barnes mussels (Elliptio complanata) exposed to an abrupt increase in ambient tritium levels

    International Nuclear Information System (INIS)

    To improve understanding of environmental tritium behaviour, the International Atomic Energy Agency (IAEA) included a Tritium and C-14 Working Group (WG) in its EMRAS (Environmental Modelling for Radiation Safety) program. One scenario considered by the WG involved the prediction of time-dependent tritium concentrations in freshwater mussels that were subjected to an abrupt increase in ambient tritium levels. The experimental data used in the scenario were obtained from a study in which freshwater Barnes mussels (Elliptio complanata) were transplanted from an area with background tritium concentrations to a small Canadian Shield lake that contains elevated tritium. The mussels were then sampled over 88 days, and concentrations of free-water tritium (HTO) and organically-bound tritium (OBT) were measured in the soft tissues to follow the build-up of tritium in the mussels over time. The HTO concentration in the mussels reached steady state with the concentration in lake water within one or two hours. Most models predicted a longer time (up to a few days) to equilibrium. All models under-predicted the OBT concentration in the mussels one hour after transplantation, but over-predicted the rate of OBT formation over the next 24 h. Subsequent dynamics were not well modelled, although all participants predicted OBT concentrations that were within a factor of three of the observation at the end of the study period. The concentration at the final time point was over-predicted by all but one of the models. The relatively low observed concentration at this time was likely due to the loss of OBT by mussels during reproduction.

  3. Individual vocal signatures in barn owl nestlings: does individual recognition have an adaptive role in sibling vocal competition?

    Science.gov (United States)

    Dreiss, A N; Ruppli, C A; Roulin, A

    2014-01-01

    To compete over limited parental resources, young animals communicate with their parents and siblings by producing honest vocal signals of need. Components of begging calls that are sensitive to food deprivation may honestly signal need, whereas other components may be associated with individual-specific attributes that do not change with time such as identity, sex, absolute age and hierarchy. In a sib-sib communication system where barn owl (Tyto alba) nestlings vocally negotiate priority access to food resources, we show that calls have individual signatures that are used by nestlings to recognize which siblings are motivated to compete, even if most vocalization features vary with hunger level. Nestlings were more identifiable when food-deprived than food-satiated, suggesting that vocal identity is emphasized when the benefit of winning a vocal contest is higher. In broods where siblings interact iteratively, we speculate that individual-specific signature permits siblings to verify that the most vocal individual in the absence of parents is the one that indeed perceived the food brought by parents. Individual recognition may also allow nestlings to associate identity with individual-specific characteristics such as position in the within-brood dominance hierarchy. Calls indeed revealed age hierarchy and to a lower extent sex and absolute age. Using a cross-fostering experimental design, we show that most acoustic features were related to the nest of origin (but not the nest of rearing), suggesting a genetic or an early developmental effect on the ontogeny of vocal signatures. To conclude, our study suggests that sibling competition has promoted the evolution of vocal behaviours that signal not only hunger level but also intrinsic individual characteristics such as identity, family, sex and age. PMID:24266879

  4. Vi har sett och hört den, men var då? : En enkätundersökning om barns och vuxnas relation till instrumentet trumpet

    OpenAIRE

    Aasen, Andreas

    2014-01-01

    Studiens syfte är att undersöka om barn och föräldrar känner till instrumentet trumpet och vilka föreställningar de har om detta instrument.   Mina frågeställningar är:   Vad vet 6-7 åringar och deras föräldrar om instrumentet trumpet? Vilka föreställningar har de om instrumentet trumpet?   För att ta reda på dessa frågor har jag genomförd en enkätstudie i Arvika med barn i första klass och deras föräldrar. 33 vuxna och 34 barn från sammanlagt tre skolor deltog i undersökningen.   Resultaten...

  5. "Interrupted" eller "Imaginal Exposure"? : EMDR og de Kreative Art -Terapiene i Traumebehandling av Barn og Ungdom. Er metodene så forskjellige?

    OpenAIRE

    2012-01-01

    Sammendrag Problemområde: Det er gjort begrenset forskning på bruken av de kreative art-terapiene, når det gjelder barn med PTSD (Goodman, Chapman & Gant (2009). Foreløpig finnes det kun en randomisert kontrollert studie (Chapman, Morabito, Ladkas, Schreiner & Knudson, 2001). Det er også mangel på eksperimentell forskning, når det gjelder nytten av slike metoder i forhold til voksne med samme diagnose. Beskrivelser av effekt av tilnærmingen overfor voksne er ofte hentet fra kliniske ra...

  6. Normal xeroradiographic and radiographic anatomy of the great horned owl (Bubo virginianus), with special reference to the barn owl (Tyto alba)

    International Nuclear Information System (INIS)

    The purpose of this study was to provide a reference for xeroradiographic and conventional radiographic anatomy of the great horned owl (Bubo virginianus) as a representative of the avian Order Strigiformes. The head, body, wing, and pelvic limb of three adult birds were radiographed using xeroradiographic and conventional radiographic techniques. Twelve xeroradiographs and their corresponding conventional radiographs were selected, and the xeroradiographs labeled to illustrate normal anatomy. Selected views of the barn owl (Tyto alba) were included to illustrate significant differences between this and other species of owls

  7. Kan det være noe i tillegg? : en kartleggingsundersøkelse av hyperaktivitet og konsentrasjonsvansker hos barn med stoffskiftesykdommen PKU

    OpenAIRE

    2007-01-01

    Denne studien er en kartleggingsundersøkelse for å se på sammenhengen mellom hyperaktivitet og konsentrasjonsvansker hos barn med Fenylketonuri (PKU), som er en medfødt arvelig stoffskiftesykdom. Sykdommen kalles heretter PKU. Tidligere studier og uttalelser fra foreldre og fagfolk har antydet en slik sammenheng. Jeg ønsket videre å se på betydningen av vanskene i elevenes skolehverdag. For å få økt kunnskap om sammenhengen ble følgende problemstilling valgt; ”I hvilken grad eksist...

  8. Finnes det lesere til avisen om 30 år? : en undersøkelse om barn og unges avislesing og deres refleksjoner over avisen som medium

    OpenAIRE

    2003-01-01

    Det vil fortsatt finnes avislesere om 30 år, men hva slags aviser avhenger av avisene selv, og om de tar dagens barn og unge på alvor. De fleste av de 24 skoleelevene, som i fire måneder gjennom spørreskjemaer, gruppediskusjoner og skriftlige oppgaver reflekterte over sin avislesing, ønsker å kunne lese avis også i framtiden, enten på papir eller på nett. De oppfatter papiraviser som mer seriøse enn nettaviser. De er opptatt av sladrestoff, men for dem betyr sladder også å bry seg om hva som ...

  9. Survey of research reactors

    International Nuclear Information System (INIS)

    A survey of reasearch reactors based on the IAEA Nuclear Research Reactor Data Base (RRDB) was done. This database includes information on 273 operating research reactors ranging in power from zero to several hundred MW. From these 273 operating research reactors 205 reactors have a power level below 5 MW, the remaining 68 reactors range from 5 MW up to several 100 MW thermal power. The major reactor types with common design are: Siemens Unterrichtsreaktors, 1.2 Argonaut reactors, Slowpoke reactors, the miniature neutron source reactors, TRIGA reactors, material testing reactors and high flux reactors. Technical data such as: power, fuel material, fuel type, enrichment, maximum neutron flux density and experimental facilities for each reactor type as well as a description of their utilization in physics and chemistry, medicine and biology, academic research and teaching, training purposes (students and physicists, operating personnel), industrial application (neutron radiography, silicon neutron transmutation doping facilities) are provided. The geographically distribution of these reactors is also shown. As conclusions the author discussed the advantages (low capital cost, low operating cost, low burn up, simple to operate, safe, less restrictive containment and sitting requirements, versatility) and disadvantages (lower sensitivity for NAA, limited radioisotope production, limited use of neutron beams, limited access to the core, licensing) of low power research reactors. 24 figs., refs. 15, Tab. 1 (nevyjel)

  10. Department of reactor technology

    International Nuclear Information System (INIS)

    The activities of the Department of Reactor Technology at Risoe during 1979 are described. The work is presented in five chapters: Reactor Engineering, Reactor Physics and Dynamics, Heat Transfer and Hydraulics, The DR 1 Reactor, and Non-Nuclear Activities. A list of the staff and of publications is included. (author)

  11. RB reactor noise analysis

    International Nuclear Information System (INIS)

    Statistical fluctuations of reactivity represent reactor noise. Analysis of reactor noise enables determining a series of reactor kinetic parameters. Fluctuations of power was measured by ionization chamber placed next to the tank of the RB reactor. The signal was digitized by an analog-digital converter. After calculation of the mean power, 3000 data obtained by sampling were analysed

  12. Research Nuclear Reactors

    International Nuclear Information System (INIS)

    Published in English and in French, this large report first proposes an overview of the use and history of research nuclear reactors. It discusses their definition, and presents the various types of research reactors which can be either related to nuclear power (critical mock-ups, material test reactors, safety test reactors, training reactors, prototypes), or to research (basic research, industry, health), or to specific particle physics phenomena (neutron diffraction, isotope production, neutron activation, neutron radiography, semiconductor doping). It reports the history of the French research reactors by distinguishing the first atomic pile (ZOE), and the activities and achievements during the fifties, the sixties and the seventies. It also addresses the development of instrumentation for research reactors (neutron, thermal, mechanical and fission gas release measurements). The other parts of the report concern the validation of neutronics calculations for different reactors (the EOLE water critical mock-up, the MASURCA air critical mock-up dedicated to fast neutron reactor study, the MINERVE water critical mock-up, the CALIBAN pulsed research reactor), the testing of materials under irradiation (OSIRIS reactor, laboratories associated with research reactors, the Jules Horowitz reactor and its experimental programs and related devices, irradiation of materials with ion beams), the investigation of accident situations (on the CABRI, Phebus, Silene and Jules Horowitz reactors). The last part proposes a worldwide overview of research reactors

  13. Evidence for Critical Energy for Ion Confinement in Magnetic Fusion Reactors

    Science.gov (United States)

    Maglich, Bogdan; Hester, Tim; Scott, Dan; Calsec Collaboration

    2015-03-01

    It is shown here that fusion test reactors could not ignite for half-a-century because trials were conducted at thermonuclear ion energies 10-30 KeV, an order of magnitude lower than critical energy, Ec ~ 200 KeV. At subcritical energies, plasma is destroyed by neutralization of ions via overlooked atomic (non-nuclear) charge transfer collisions with giant cross-section, 109 barns, 100 times greater than that for ionization collisions that counters neutralization. Neutral injection sets limit on ion magnetic confinement time 1 s required for ignition. In contrast, at energies above Ec, ionization prevails; near ~ 1 MeV, stable confinement of 20 s was routinely observed with charged injection. - To render ITER viable, ion energy must be increased to >/ = 1 MeV; neutral radioactive DT fuel replaced with charged, nonradioactive deuterium, giving rise to compact aneutronicreactor with direct conversion into RF power.

  14. Reactor Physics Training

    International Nuclear Information System (INIS)

    University courses in nuclear reactor physics at the universities consist of a theoretical description of the physics and technology of nuclear reactors. In order to demonstrate the basic concepts in reactor physics, training exercises in nuclear reactor installations are also desirable. Since the number of reactor facilities is however strongly decreasing in Europe, it becomes difficult to offer to students a means for demonstrating the basic concepts in reactor physics by performing training exercises in nuclear installations. Universities do not generally possess the capabilities for performing training exercises. Therefore, SCK-CEN offers universities the possibility to perform (on a commercial basis) training exercises at its infrastructure consisting of two research reactors (BR1 and VENUS). Besides the organisation of training exercises in the framework of university courses, SCK-CEN also organizes theoretical courses in reactor physics for the education and training of nuclear reactor operators. It is indeed a very important subject to guarantee the safe operation of present and future nuclear reactors. In this framework, an understanding of the fundamental principles of nuclear reactor physics is also necessary for reactor operators. Therefore, the organisation of a basic Nuclear reactor physics course at the level of reactor operators in the initial and continuous training of reactor operators has proven to be indispensable. In most countries, such training also results from the direct request from the safety authorities to assure the high level of competence of the staff in nuclear reactors. The objectives this activity are: (1) to provide training and education activities in reactor physics for university students and (2) to organise courses in nuclear reactor physics for reactor operators

  15. Introduction of Nuclear Reactor Engineering

    International Nuclear Information System (INIS)

    This book introduces development, status, supply and demand and resource of nuclear reactor. It deals with basic knowledge of nuclear reactor, which are reactor system, heat recovery in reactor core, structural feature in reactor, materials of structure in reactor, shielding of gamma ray, shielding of reactor, safety and environmental problem of nuclear power plant, nuclear fuel and economical efficiency of nuclear energy.

  16. Improvement of Drying Temperature Control Method in Tobacco-Flue-Cured Barn%烤烟烘烤房干温度控制方法的改进

    Institute of Scientific and Technical Information of China (English)

    李英俊; 金珖龙

    2011-01-01

    为了提高烤烟烘烤房的干温度精度和烤烟的烘烤质量,降低耗煤量,对往复推动式烟叶烘烤仪的干温度的控制方法进行了改进.通过利用模糊控制技术控制推煤电动机工作时间和停止工作时间,实现了根据烘烤工艺的要求对烤烟烘烤房的干温度进行实时监测的精确控制目标.%To improve the precision of drying temperature control of tobacco-flue-cured barn and the quality of flue-cured tobacco,and to reduce coal consumption for flue-cured tobacco,the drying temperature control method for the flue-cured tobacco apparatus with reciprocating transport function was improved.The working time and halting time of a coal-transport electric motor were controlled by fuzzy control technology,with the technology above the real-time of the accuracy control of the drying temperature of tobacco flue-cured barn was realized.

  17. A percepção de valor dos ativos entre o mundo real e o virtual: o caso Barnes and Noble

    Directory of Open Access Journals (Sweden)

    Dalton Schmitt Jr

    2002-01-01

    Full Text Available Uma das questões de grande debate no mercado de investimentos gira em torno da diferença entre a valorização e a volatilidade de ativos relacionados a empresas do mundo real e empresas do mundo virtual (nova economia. O maior fluxo as informações, a incerteza e a inexistência de um modelo de negócio vencedor na nova economia têm ampliado essa discussão ao longo dos anos. O presente artigo tem como objetivo analisar a valorização de ativos de empresas desses dois mundos (real e virtual de mesmo foco de negócio e voltadas ao mesmo mercado em relação aos seus principais índices financeiros e performance. Estar-se-ão analisando dois negócios com mesmo fim de mercado mas que, por estarem com posicionamentos diferentes, apresentam características diferenciadas no que se refere a valorização de mercado e performance financeira. Visando desenvolver tal objetivo, o artigo analisará as empresa Barnes & Noble, tradicional varejista do segmento de livros no mercado norte-americano, e a sua subsidiária Barnes & Noble.com.

  18. Safeguarding research reactors

    International Nuclear Information System (INIS)

    The report is organized in four sections, including the introduction. The second section contains a discussion of the characteristics and attributes of research reactors important to safeguards. In this section, research reactors are described according to their power level, if greater than 25 thermal megawatts, or according to each fuel type. This descriptive discussion includes both reactor and reactor fuel information of a generic nature, according to the following categories. 1. Research reactors with more than 25 megawatts thermal power, 2. Plate fuelled reactors, 3. Assembly fuelled reactors. 4. Research reactors fuelled with individual rods. 5. Disk fuelled reactors, and 6. Research reactors fuelled with aqueous homogeneous fuel. The third section consists of a brief discussion of general IAEA safeguards as they apply to research reactors. This section is based on IAEA safeguards implementation documents and technical reports that are used to establish Agency-State agreements and facility attachments. The fourth and last section describes inspection activities at research reactors necessary to meet Agency objectives. The scope of the activities extends to both pre and post inspection as well as the on-site inspection and includes the examination of records and reports relative to reactor operation and to receipts, shipments and certain internal transfers, periodic verification of fresh fuel, spent fuel and core fuel, activities related to containment and surveillance, and other selected activities, depending on the reactor

  19. Research nuclear reactors

    International Nuclear Information System (INIS)

    Since the divergence of the first nuclear reactor in 1942, about 600 research or test reactors have been built throughout the world. Today 255 research reactors are operating in 57 countries and about 70% are over 25 years old. Whereas there are very few reactor types for power plants because of rationalization and standardisation, there is a great diversity of research reactors. We can divide them into 2 groups: heavy water cooled reactors and light water moderated reactors. Heavy water cooled reactors are dedicated to the production of high flux of thermal neutrons which are extracted from the core by means of neutronic channels. Light water moderated reactors involved pool reactors and slightly pressurized closed reactors, they are polyvalent but their main purposes are material testing, technological irradiations, radionuclide production and neutron radiography. At the moment 8 research reactors are being built in Canada, Germany, Iran, Japan, Kazakhstan, Morocco, Russia and Slovakia and 8 others are planned in 7 countries (France, Indonesia, Nigeria, Russia, Slovakia, Thailand and Tunisia. Different research reactors are described: Phebus, Masurca, Phenix and Petten HFR. The general principles of nuclear safety applied to test reactors are presented. (A.C.)

  20. Nuclear reactor building

    International Nuclear Information System (INIS)

    Purpose: To prevent seismic vibrations of external buildings from transmitting to the side walls of a reactor container in a tank type FBR reactor building. Constitution: The reactor building is structured such that the base mat for a reactor container chamber and a reactor container is separated from the base mat for the walls of building, and gas-tight material such as silicon rubber is filled in the gap therebetween. With such a constitution, even if the crane-supporting wall vibrates violently upon occurrence of earthqualkes, the seismic vibrations do not transmit toward the reactor container chamber. (Horiuchi, T.)

  1. Reactor Physics Programme

    International Nuclear Information System (INIS)

    The Reactor Physics and Department of SCK-CEN offers expertise in various areas of reactor physics, in particular in neutronics calculations, reactor dosimetry, reactor operation, reactor safety and control and non-destructive analysis on reactor fuel. This expertise is applied within the Reactor Physics and MYRRHA Research Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 reactor dosimetry, and the preparation and interpretation of irradiation experiments. Progress and achievements in 1999 in the following areas are reported on: (1) investigations on the use of military plutonium in commercial power reactors; (2) neutron and gamma calculations performed for BR-2 and for other reactors; (3) the updating of neutron and gamma cross-section libraries; (4) the implementation of reactor codes; (6) the management of the UNIX workstations; and (6) fuel cycle studies

  2. Ship propulsion reactors technology

    International Nuclear Information System (INIS)

    This paper takes the state of the art on ship propulsion reactors technology. The french research programs with the corresponding technological stakes, the reactors specifications and advantages are detailed. (A.L.B.)

  3. Undergraduate reactor control experiment

    International Nuclear Information System (INIS)

    A sequence of reactor and related experiments has been a central element of a senior-level laboratory course at Pennsylvania State University (Penn State) for more than 20 yr. A new experiment has been developed where the students program and operate a computer controller that manipulates the speed of a secondary control rod to regulate TRIGA reactor power. Elementary feedback control theory is introduced to explain the experiment, which emphasizes the nonlinear aspect of reactor control where power level changes are equivalent to a change in control loop gain. Digital control of nuclear reactors has become more visible at Penn State with the replacement of the original analog-based TRIGA reactor control console with a modern computer-based digital control console. Several TRIGA reactor dynamics experiments, which comprise half of the three-credit laboratory course, lead to the control experiment finale: (a) digital simulation, (b) control rod calibration, (c) reactor pulsing, (d) reactivity oscillator, and (e) reactor noise

  4. Process heat reactors

    International Nuclear Information System (INIS)

    The consumption of heat, for industrial and domestic needs, takes up half of the national energy supply; direct utilization of the heat produced by nuclear reactors could therefore contribute to reduce the deficit in the energetic results. The restraints proper to heat consumption (dispersal and variety of consumers, irregular demand) involve the development of the heat transport system structures and adequate nuclear reactors. With this in view, the Commissariat a l'Energie Atomique and Technicatome are developing the CAS reactor series, pressurized water reactors (PWR), (CAS 3G reactor with a power of 420 MW.th.), and the Thermos reactor (100 MW.th.), directly conceived to produce heat at 1200C and whose technology derives from the experimental pool reactors type. In order to prove the value of the Thermos design, an experimental reactor should soon be constructed in the Saclay nuclear research centre

  5. Reactor System Design

    International Nuclear Information System (INIS)

    SMART NPP(Nuclear Power Plant) has been developed for duel purpose, electricity generation and energy supply for seawater desalination. The objective of this project IS to design the reactor system of SMART pilot plant(SMART-P) which will be built and operated for the integrated technology verification of SMART. SMART-P is an integral reactor in which primary components of reactor coolant system are enclosed in single pressure vessel without connecting pipes. The major components installed within a vessel includes a core, twelve steam generator cassettes, a low-temperature self pressurizer, twelve control rod drives, and two main coolant pumps. SMART-P reactor system design was categorized to the reactor coe design, fluid system design, reactor mechanical design, major component design and MMIS design. Reactor safety -analysis and performance analysis were performed for developed SMART=P reactor system. Also, the preparation of safety analysis report, and the technical support for licensing acquisition are performed

  6. Nuclear Reactor RA Safety Report, Vol. 11, Reactor operation

    International Nuclear Information System (INIS)

    This volume includes the following chapters describing: Organisation of reactor operation (including operational safety, fuel management, and regulatory rules for RA reactor operation); Control and maintenance of reactor components (reactor core, nuclear fuel, heavy water and cover gas systems, mechanical structures, electric power supply system, reactor instrumentation); Quality assurance and Training of the reactor personnel

  7. The Chernobylsk reactor accident

    International Nuclear Information System (INIS)

    The construction, the safety philosophy, the major reactor physical parameters of RBMK-1000 type reactor units and the detailed description of the Chernobylsk-4 reactor accident, its causes and conclusions, the efforts to reduce the consequences on the reactor site and in the surroundings are discussed based on different types of Soviet documents including the report presented to the IAEA by the Soviet Atomic Energy Agency in August 1986. (V.N.)

  8. Zero energy reactor 'RB'

    International Nuclear Information System (INIS)

    In 1958 the zero energy reactor RB was built with the purpose of enabling critical experiments with various reactor systems to be carried out. The first core assembly built in this reactor consists of heavy water as moderator and natural uranium metal as fuel. In order to be able to obtain very accurate results when measuring the main characteristics of the assembly the reactor was built as a completely bare system. (author)

  9. High solids fermentation reactor

    Science.gov (United States)

    Wyman, Charles E.; Grohmann, Karel; Himmel, Michael E.; Richard, Christopher J.

    1993-01-01

    A fermentation reactor and method for fermentation of materials having greater than about 10% solids. The reactor includes a rotatable shaft along the central axis, the shaft including rods extending outwardly to mix the materials. The reactor and method are useful for anaerobic digestion of municipal solid wastes to produce methane, for production of commodity chemicals from organic materials, and for microbial fermentation processes.

  10. Fossil nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Maurette, M.

    1976-01-01

    The discussion of fossil nuclear reactors (the Oklo phenomenon) covers the earth science background, neutron-induced isotopes and reactor operating conditions, radiation-damage studies, and reactor modeling. In conclusion possible future studies are suggested and the significance of the data obtained in past studies is summarized. (JSR)

  11. Fusion reactor studies

    International Nuclear Information System (INIS)

    A review is given of fusion reactor systems studies, the objectives of these studies are outlined and some recent conceptual reactor designs are described. The need for further studies in greater depth is indicated so that progress towards a commercial fusion reactor may be consolidated. (U.K.)

  12. Reactor power measuring device

    International Nuclear Information System (INIS)

    The present invention provides a self-powered long detector having a sensitivity over the entire length of a reactor core as an entire control rod withdrawal range of a BWR type reactor, and a reactor power measuring device using a gamma ray thermometer which scarcely causes sensitivity degradation. That is, a hollow protection pipe is disposed passing through the reactor core from the outside of a reactor pressure vessel. The self-powered long detectors and the gamma ray thermometers are inserted and installed in the protection pipe. An average reactor power in an axial direction of the reactor relative to a certain position in the horizontal cross section of the reactor core is determined based on the power of the self-powered long detector over the entire length of the reactor core. Since the response of the self-powered detector relative to a local power change is rapid, the output is used as an input signal to a safety protection device of the reactor core. Further, a gamma ray thermometer secured in the reactor and having scarce sensitivity degradation is used instead of an incore travelling neutron monitor used for relative calibration of an existent neutron monitor secured in the reactor. (I.S.)

  13. Effect of Lean Controlled Curing Barn on Tobacco Curing%精益控制烤房对烟叶烘烤的影响研究

    Institute of Scientific and Technical Information of China (English)

    黄国强; 陈道颖; 陈娟; 贾健; 谢扬军; 郭松

    2016-01-01

    为进一步提高烟叶的烘烤质量和烤房的自动化烘烤水平,通过安装自动变频控制仪、自动烟囱闸火门和助燃风机保护器来提高密集烤房精益控制程度,改善烘烤质量。结果表明:使用精益控制烤房烘烤烟叶能显著提高烤房对装烟内温湿度的控制精度和烤后烟叶的外观质量,烘烤的能耗成本降低了13.40%,每千克干烟的烘烤收益增加了27.11%;助燃风机保护器能够显著降低助燃风机停机状态下机壳表面的温度,并大大减少风机的损耗率。%In order to improve the curing quality of tobacco leaves and automatic curing level of curing barn, installed auto-matic frequency control instrument, automatic chimney gate door and combustion supporting wind machine protector to improve the degree of bulk curing barn lean control and improve the baking quality.The results showed that cured by lean controlled curing barn significantly improved the control precision of temperature and humidity inside the loading room, significantly improved the appearance quality of the flue-cured tobacco leaves, and the cost of energy consumption was reduced by 13.40%, and the earn-ings of per kg tobacco leaves after curing increased by 27.11%.Combustion fan protector significantly lowered the temperature of the surface casing when combustion fan stopped, and greatly reduced the attrition rate of the fan.

  14. Upper limit on the cross section for reactor antineutrinos changing 22Na decay rates

    CERN Document Server

    de Meijer, R J

    2014-01-01

    In this paper we present results of a long-term observation of the decay of 22Na in the presence of a nuclear fission reactor. The measurements were made outside the containment wall of and underneath the Koeberg nuclear power plant near Cape Town, South Africa. Antineutrino fluxes ranged from ~5*10^11 to 1.6*10^13 cm^-2 s^-1 during this period. We show that the coincidence summing technique provides a sensitive tool to measure a change in the total decay constant as well as the branching ratio between EC and beta+ decay of 22Na to the first excited state in 22Ne. We observe a relative change in count rate between reactor-ON and reactor-OFF equal to (-0.51+/-0.11)*10^-4. After evaluating possible systematic uncertainties we conclude that the effect is either due to a hidden instrumental cause or due to an interaction between antineutrinos and the 22Na nucleus. An upper limit of ~0.03 barn has been deduced for observing any change in the decay rate of 22Na due to antineutrino interactions.

  15. Light water reactor safety

    CERN Document Server

    Pershagen, B

    2013-01-01

    This book describes the principles and practices of reactor safety as applied to the design, regulation and operation of light water reactors, combining a historical approach with an up-to-date account of the safety, technology and operating experience of both pressurized water reactors and boiling water reactors. The introductory chapters set out the basic facts upon which the safety of light water reactors depend. The central section is devoted to the methods and results of safety analysis. The accidents at Three Mile Island and Chernobyl are reviewed and their implications for light wate

  16. Nuclear reactor repairing device

    International Nuclear Information System (INIS)

    Purpose: To enable free repairing of an arbitrary position in an LMFBR reactor. Constitution: A laser light emitted from a laser oscillator installed out of a nuclear reactor is guided into a portion to be repaired in the reactor by using a reflecting mirror, thereby welding or cutting it. The guidance of the laser out of the reactor into the reactor is performed by an extension tube depending into a through hole of a rotary plug, and the guidance of the laser light into a portion to be repaired is performed by the transmitting and condensing action of the reflecting mirror. (Kamimura, M.)

  17. Fundamentals of reactor chemistry

    International Nuclear Information System (INIS)

    In the Nuclear Engineering School of JAERI, many courses are presented for the people working in and around the nuclear reactors. The curricula of the courses contain also the subject material of chemistry. With reference to the foreign curricula, a plan of educational subject material of chemistry in the Nuclear Engineering School of JAERI was considered, and the fundamental part of reactor chemistry was reviewed in this report. Since the students of the Nuclear Engineering School are not chemists, the knowledge necessary in and around the nuclear reactors was emphasized in order to familiarize the students with the reactor chemistry. The teaching experience of the fundamentals of reactor chemistry is also given. (author)

  18. Nuclear reactor physics

    CERN Document Server

    Stacey, Weston M

    2010-01-01

    Nuclear reactor physics is the core discipline of nuclear engineering. Nuclear reactors now account for a significant portion of the electrical power generated worldwide, and new power reactors with improved fuel cycles are being developed. At the same time, the past few decades have seen an ever-increasing number of industrial, medical, military, and research applications for nuclear reactors. The second edition of this successful comprehensive textbook and reference on basic and advanced nuclear reactor physics has been completely updated, revised and enlarged to include the latest developme

  19. Barns tankar och idéer om himlakropparnas rörelse : Vanliga astronomiska missförstånd

    OpenAIRE

    Johansson, Elin

    2014-01-01

    Sammanfattning De flesta barn fängslas och visar intresse för temat rymden och finner vanligtvis att det är ett mycket intressant ämne. Fokusgruppen har varit elever i årskurs 4-6 och efter några större bortfall var det slutligen elever ifrån 8 klasser som deltog, totalt 94 elever. Eleverna fick svara på en enkät där eleverna i både text och bild bland annat fick förklara hur de trodde att objekten i sol–jord–månsystemet samverkade och rörde sig i förhållande till varandra, vad de placerade i...

  20. Stress och välbefinnande hos föräldrar till barn i övre tonåren

    OpenAIRE

    Alm Sönnergren, Susanne

    2008-01-01

    I denna enkätstudie undersöktes stress och välbefinnande hos 224 slumpmässigt utvalda föräldrar i Stockholmsområdet, med hemmavarande barn i övre tonåren. Ryff Well-Being Scale plus en nykonstruerad föräldrastresskala användes; den sistnämnda visade sig ha god intern konsistens och i övrigt godtagbara psykometriska kvaliteter. Tonårsföräldrarna rapporterade något högre välbefinnande än en tidigare normgrupp. Grad av välbefinnande, specifikt dimensionerna självacceptans (self acceptance) och k...

  1. Småbarnsfamiljers kostvanor : En studie om kostkvalitet och föräldrars inverkan på barns ätvanor

    OpenAIRE

    Qvarnström, Eva

    2007-01-01

    Många människor har svårt att etablera goda matvanor trots ett ständigt informationsflöde om hur ohälsosam kost påverkar hälsan negativt. Små barn befinner sig i en beroendeställning till de vuxna som finns runt dem. Det innebär att föräldrarnas kostvanor även blir barnens. De vuxna bestämmer vad som finns hemma och vad som serveras. Denna kvantitativa studie har undersökt småbarnsfamiljers kostvanor med utgångspunkt i Livsmedelsverkets rekommendationer om mindre mättat fett, mindre socker, m...

  2. Föräldrarnas upplevelser av att vara förälder till ett barn med Anorexia Nervosa : En litteraturstudie

    OpenAIRE

    Karat, Azra; Modin, Jens

    2013-01-01

    Bakgrund: Anorexia Nervosa påverkar inte enbart det sjuka barnet utan kan även vara påfrestande för föräldrarna. Föräldrarna kan behöva göra stora förändringar för att det vardagliga livet skall fungera. Syfte: Syftet med studien var att beskriva föräldrarnas upplevelser av att vara förälder till ett barn med Anorexia Nervosa. Metod: Metoden som användes var en kvalitativ litteraturstudie som baserades på tre självbiografiska böcker. Graneheim och Lundmans beskrivning av innehållsanalys med m...

  3. Dialektal medvetenhet hos barn : En jämförande studie mellan åldrarna 5, 8 och 11 år

    OpenAIRE

    Beckman, Elsa; Domeij, Erica

    2014-01-01

    Dialektal medvetenhet är en förmåga som grundas i en metaspråklig förmåga, det vill säga att kunna resonera kring språk och hantera språkliga enheter. Exempel på detta är att med hjälp av prosodi kunna utläsa information i tal såsom känslor och dialekter. Det finns relativt lite forskning angående barns dialektala medvetenhet. Däremot finns mer forskning inom metaspråklig utveckling. En god metaspråklig förmåga hör samman med god generell språkutveckling och en metaspråklig kompetens innebär ...

  4. Generation III+ Reactor Portfolio

    International Nuclear Information System (INIS)

    While the power generation needs of utilities are unique and diverse, they are all faced with the double challenge of meeting growing electricity needs while curbing CO2 emissions. To answer these diverse needs and help tackle this challenge, AREVA has developed several reactor models which are briefly described in this document: The EPRTM Reactor: designed on the basis of the Konvoi (Germany) and N4 (France) reactors, the EPRTM reactor is an evolutionary model designed to achieve best-in-class safety and operational performance levels. The ATMEA1TM reactor: jointly designed by Mitsubishi Heavy Industries and AREVA through ATMEA, their common company. This reactor design benefits from the competencies and expertise of the two mother companies, which have commissioned close to 130 reactor units. The KERENATM reactor: Designed on the basis of the most recent German BWR reactors (Gundremmingen) the KERENATM reactor relies on proven technology while also including innovative, yet thoroughly tested, features. The optimal combination of active and passive safety systems for a boiling water reactor achieves a very low probability of severe accident

  5. The Maple reactor project

    International Nuclear Information System (INIS)

    MDS Nordion supplies the majority of the world's reactor-produced medical isotopes. These isotopes are currently produced in the NRU reactor at AECL's Chalk River Laboratories (CRL). Medical isotopes and related technology are relied upon around the world to prevent, diagnose and treat disease. The NRU reactor, which has played a key role in supplying medical isotopes to date, has been in operation for over 40 years. Replacing this aging reactor has been a priority for MDS Nordion to assure the global nuclear medicine community that Canada will continue to be a dependable supplier of medical isotopes. MDS Nordion contracted AECL to construct two MAPLE reactors dedicated to the production of medical isotopes. The MDS Nordion Medical Isotope Reactor (MMIR) project started in September 1996. This paper describes the MAPLE reactors that AECL has built at its CRL site, and will operate for MDS Nordion. (author)

  6. High temperature reactors

    International Nuclear Information System (INIS)

    With the advent of high temperature reactors, nuclear energy, in addition to producing electricity, has shown enormous potential for the production of alternate transport energy carrier such as hydrogen. High efficiency hydrogen production processes need process heat at temperatures around 1173-1223 K. Bhabha Atomic Research Centre (BARC), is currently developing concepts of high temperature reactors capable of supplying process heat around 1273 K. These reactors would provide energy to facilitate combined production of hydrogen, electricity, and drinking water. Compact high temperature reactor is being developed as a technology demonstrator for associated technologies. Design has been also initiated for a 600 MWth innovative high temperature reactor. High temperature reactor development programme has opened new avenues for research in areas like advanced nuclear fuels, high temperature and corrosion resistant materials and protective coatings, heavy liquid metal coolant technologies, etc. The paper highlights design of these reactors and their material related requirements

  7. Spinning fluids reactor

    Science.gov (United States)

    Miller, Jan D; Hupka, Jan; Aranowski, Robert

    2012-11-20

    A spinning fluids reactor, includes a reactor body (24) having a circular cross-section and a fluid contactor screen (26) within the reactor body (24). The fluid contactor screen (26) having a plurality of apertures and a circular cross-section concentric with the reactor body (24) for a length thus forming an inner volume (28) bound by the fluid contactor screen (26) and an outer volume (30) bound by the reactor body (24) and the fluid contactor screen (26). A primary inlet (20) can be operatively connected to the reactor body (24) and can be configured to produce flow-through first spinning flow of a first fluid within the inner volume (28). A secondary inlet (22) can similarly be operatively connected to the reactor body (24) and can be configured to produce a second flow of a second fluid within the outer volume (30) which is optionally spinning.

  8. Reactor Safety: Introduction

    International Nuclear Information System (INIS)

    The programme of the Reactor Safety Division focuses on the development of expertise on materials behaviour under irradiation for fission and fusion oriented applications. Furthermore, as nuclear energy needs international public acceptance with respect to safety and efficient management of natural resources and wants to reduce the burden of nuclear waste, the Reactor Safety Division enhanced its efforts to develop the MYRRHA project. MYRRHA, an accelerator driven sub-critical system, might have the potential to cope in Europe with the above mentioned constraints on acceptability and might serve as a technological platform for GEN IV reactor development, in particular the Liquid Metal Fast Reactor.The Reactor Safety Division gathers three research entities that are internationally recognised: the Reactor Materials Research department, the Reactor Physics and MYRRHA department and the Instrumentation department.The objectives of Reactor Materials Research are: to evaluate the integrity and behaviour of structural materials and nuclear fuels used in present and future nuclear power industry; to perform research to unravel and understand the parameters that determine the material and fuel behaviour under or after irradiation; to contribute to the interpretation and modelling of the materials and fuels behaviour in order to develop and assess strategies for optimum life management of nuclear power plant components. The programmes within the Reactor Materials Research department concentrate on four distinct disciplines: Reactor Pressure Vessel Steel embrittlement Stress corrosion cracking in reactor coolant environment, including Irradiation Assisted Stress Corrosion Cracking; Nuclear Fuel characterisation and development of new fuel types for commercial and test reactors. Development of materials for Fusion and advanced nuclear fission reactors. The safe operation of present nuclear power plants relies primarily on the integrity of the reactor pressure vessel

  9. Research reactors in Argentina

    International Nuclear Information System (INIS)

    Argentine Nuclear Development started in early fifties. In 1957, it was decided to built the first a research reactor. RA-1 reactor (120 kw, today licensed to work at 40 kW) started operation in January 1958. Originally RA-1 was an Argonaut (American design) reactor. In early sixties, the RA-1 core was changed. Fuel rods (20% enrichment) was introduced instead the old Argonaut core design. For that reason, a critical facility named RA-0 was built. After that, the RA-3 project started, to build a multipurpose 5 MW nuclear reactor MTR pool type, to produce radioisotopes and research. For that reason and to define the characteristics of the RA-3 core, another critical facility was built, RA-2. Initially RA-3 was a 90 % enriched fuel reactor, and started operation in 1967. When Atucha I NPP project started, a German design Power Reactor, a small homogeneous reactor was donated by the German Government to Argentina (1969). This was RA-4 reactor (20% enrichment, 1W). In 1982, RA-6 pool reactor achieved criticality. This is a 500 kW reactor with 90% enriched MTR fuel elements. In 1990, RA-3 started to operate fueled by 20% enriched fuel. In 1997, the RA-8 (multipurpose critical facility located at Pilcaniyeu) started to operate. RA-3 reactor is the most important CNEA reactor for Argentine Research Reactors development. It is the first in a succession of Argentine MTR reactors built by CNEA (and INVAP SE ) in Argentina and other countries: RA-6 (500 kW, Bariloche-Argentina), RP-10 (10MW, Peru), NUR (500 kW, Algeria), MPR (22 MW, Egypt). The experience of Argentinian industry permits to compete with foreign developed countries as supplier of research reactors. Today, CNEA has six research reactors whose activities have a range from education and promotion of nuclear activity, to radioisotope production. For more than forty years, Argentine Research Reactors are working. The experience of Argentine is important, and argentine firms are able to compete in the design and

  10. Thai research reactor

    International Nuclear Information System (INIS)

    The Office of Atomic Energy for Peace (OAEP) was established in 1962, as a reactor center, by the virtue of the Atomic Energy for Peace Act, under operational policy and authority of the Thai Atomic Energy for Peace Commission (TAEPC); and under administration of Ministry of Science, Technology and Energy. It owns and operates the only Thai Research Reactor (TRR-1/M1). The TRR-1/M1 is a mixed reactor system constituting of the old MTR type swimming pool, irradiation facilities and cooling system; and TRIGA Mark III core and control instrumentation. The general performance of TRR-1/M1 is summarized in Table I. The safe operation of TRR-1/M1 is regulated by Reactor Safety Committee (RSC), established under TAEPC, and Health Physics Group of OAEP. The RCS has responsibility and duty to review of and make recommendations on Reactor Standing Orders, Reactor Operation Procedures, Reactor Core Loading and Requests for Reactor Experiments. In addition,there also exist of Emergency Procedures which is administered by OAEP. The Reactor Operation Procedures constitute of reactor operating procedures, system operating procedures and reactor maintenance procedures. At the level of reactor routine operating procedures, there is a set of Specifications on Safety and Operation Limits and Code of Practice from which reactor shift supervisor and operators must follow in order to assure the safe operation of TRR-1/M1. Table II is the summary of such specifications. The OAEP is now upgrading certain major components of the TRR-1/M1 such as the cooling system, the ventilation system and monitoring equipment to ensure their adequately safe and reliable performance under normal and emergency conditions. Furthermore, the International Atomic Energy Agency has been providing assistance in areas of operation and maintenance and safety analysis. (author)

  11. Nuclear Reactor Physics

    Science.gov (United States)

    Stacey, Weston M.

    2001-02-01

    An authoritative textbook and up-to-date professional's guide to basic and advanced principles and practices Nuclear reactors now account for a significant portion of the electrical power generated worldwide. At the same time, the past few decades have seen an ever-increasing number of industrial, medical, military, and research applications for nuclear reactors. Nuclear reactor physics is the core discipline of nuclear engineering, and as the first comprehensive textbook and reference on basic and advanced nuclear reactor physics to appear in a quarter century, this book fills a large gap in the professional literature. Nuclear Reactor Physics is a textbook for students new to the subject, for others who need a basic understanding of how nuclear reactors work, as well as for those who are, or wish to become, specialists in nuclear reactor physics and reactor physics computations. It is also a valuable resource for engineers responsible for the operation of nuclear reactors. Dr. Weston Stacey begins with clear presentations of the basic physical principles, nuclear data, and computational methodology needed to understand both the static and dynamic behaviors of nuclear reactors. This is followed by in-depth discussions of advanced concepts, including extensive treatment of neutron transport computational methods. As an aid to comprehension and quick mastery of computational skills, he provides numerous examples illustrating step-by-step procedures for performing the calculations described and chapter-end problems. Nuclear Reactor Physics is a useful textbook and working reference. It is an excellent self-teaching guide for research scientists, engineers, and technicians involved in industrial, research, and military applications of nuclear reactors, as well as government regulators who wish to increase their understanding of nuclear reactors.

  12. Reactor containment and reactor safety in the United States

    International Nuclear Information System (INIS)

    The reactor safety systems of two reactors are studied aiming at the reactor containment integrity. The first is a BWR type reactor and is called Peachbottom 2, and the second is a PWR type reactor, and is called surry. (E.G.)

  13. TRIGA reactor main systems

    International Nuclear Information System (INIS)

    This module describes the main systems of low power (<2 MW) and higher power (≥2 MW) TRIGA reactors. The most significant difference between the two is that forced reactor cooling and an emergency core cooling system are generally required for the higher power TRIGA reactors. However, those TRIGA reactors that are designed to be operated above 3 MW also use a TRIGA fuel that is specifically designed for those higher power outputs (3 to 14 MW). Typical values are given for the respective systems although each TRIGA facility will have unique characteristics that may only be determined by the experienced facility operators. Due to the inherent wide scope of these research reactor facilities construction and missions, this training module covers those systems found at most operating TRIGA reactor facilities but may also discuss non-standard equipment that was found to be operationally useful although not necessarily required. (author)

  14. Evaluation of research reactors

    International Nuclear Information System (INIS)

    The present status of research reactors with highly enriched (93%) uranium fuel at JAERI, JRR-2 and JMTR is described. JRR-2 is a heterogeneous type of reactor, using heavy water as moderator and coolant. It uses both MTR type and cylindrical type of fuel elements. The maximum thermal power and the thermal neutron flux are 10 MW and 2x1014 n/cm2 see respectively. The reactor has been used for various experiments such as solid state physics, material irradiation, reactor fuel irradiation and radioisotope production. The JMTR is a multi-purpose tank type material testing reactor, and light water moderator and coolant, operated at 50 MW. The evaluation of lower enriched fuel and its consequences for both reactors is considered more especially

  15. Multipurpose research reactors

    International Nuclear Information System (INIS)

    The international symposium on the utilization of multipurpose research reactors and related international co-operation was organized by the IAEA to provide for information exchange on current uses of research reactors and international co-operative projects. The symposium was attended by about 140 participants from 36 countries and two international organizations. There were 49 oral presentations of papers and 24 poster presentations. The presentations were divided into 7 sessions devoted to the following topics: neutron beam research and applications of neutron scattering (6 papers and 1 poster), reactor engineering (6 papers and 5 posters), irradiation testing of fuel and material for fission and fusion reactors (6 papers and 10 posters), research reactor utilization programmes (13 papers and 4 posters), neutron capture therapy (4 papers), neutron activation analysis (3 papers and 4 posters), application of small reactors in research and training (11 papers). A separate abstract was prepared for each of these papers. Refs, figs and tabs

  16. The nuclear soliton reactor

    International Nuclear Information System (INIS)

    The basic reactor physics of a completely novel nuclear fission reactor design - the soliton-reactor - is presented on the basis of a simple model. In such a reactor, the neutrons in the critical region convert either fertile material in the adjacent layers into fissile material or reduce the poisoning of fissile material in such a manner that successively new critical regions emerge. The result is an autocatalytically driven burn-up wave which propagates throughout the reactor. Thereby, the relevant characteristic spatial distributions (neutron flux, specific power density and the associated particle densities) are solitons - wave phenomena resulting from non-linear partial differential equations which do not change their shape during propagation. A qualitativley new kind of harnessing nuclear fission energy may become possible with fuel residence times comparable with the useful lifetime of the reactor system. In the long run, fast breeder systems which exploit the natural uranium and thorium resources, without any reprocessing capacity are imaginable. (orig.)

  17. Fast Spectrum Reactors

    CERN Document Server

    Todd, Donald; Tsvetkov, Pavel

    2012-01-01

    Fast Spectrum Reactors presents a detailed overview of world-wide technology contributing to the development of fast spectrum reactors. With a unique focus on the capabilities of fast spectrum reactors to address nuclear waste transmutation issues, in addition to the well-known capabilities of breeding new fuel, this volume describes how fast spectrum reactors contribute to the wide application of nuclear power systems to serve the global nuclear renaissance while minimizing nuclear proliferation concerns. Readers will find an introduction to the sustainable development of nuclear energy and the role of fast reactors, in addition to an economic analysis of nuclear reactors. A section devoted to neutronics offers the current trends in nuclear design, such as performance parameters and the optimization of advanced power systems. The latest findings on fuel management, partitioning and transmutation include the physics, efficiency and strategies of transmutation, homogeneous and heterogeneous recycling, in addit...

  18. Fusion reactor research

    International Nuclear Information System (INIS)

    This work covers four separate areas: (1) development of technology for processing liquid lithium from blankets, (2) investigation of hydrogen isotope permeation in candidate structural metals and alloys for near-term fusion reactors, (3) analytical studies encompassing fusion reactor thermal hydraulics, tritium facility design, and fusion reactor safety, and (4) studies involving dosimetry and damage analysis. Recent accomplishments in each of these areas are summarized

  19. The Integral Fast Reactor

    International Nuclear Information System (INIS)

    The Integral Fast Reactor (IFR) is an innovative liquid metal reactor concept being developed at Argonne National Laboratory. It seeks to specifically exploit the inherent properties of liquid metal cooling and metallic fuel in a way that leads to substantial improvements in the characteristics of the complete reactor system. This paper describes the key features and potential advantages of the IFR concept, with emphasis on its safety characteristics. 3 refs., 4 figs., 1 tab

  20. The replacement research reactor

    International Nuclear Information System (INIS)

    As a consequences of the government decision in September 1997. ANSTO established a replacement research reactor project to manage the procurement of the replacement reactor through the necessary approval, tendering and contract management stages This paper provides an update of the status of the project including the completion of the Environmental Impact Statement. Prequalification and Public Works Committee processes. The aims of the project, management organisation, reactor type and expected capabilities are also described

  1. PFBR reactor protection

    International Nuclear Information System (INIS)

    Design philosophy adopted for Prototype Fast breeder Reactor (PFBR) is a classical one and has the following features: triplicated sensors for measuring important safety parameters; two independent reactor protection Logic Systems based on solid state devices; reactivity control achieved by control rods; gas equipped modules at the core blanket interface providing negative reactivity. Design verification of these features showed that safety of the reactor can be achieved by a traditional approach since the inherent features of LMFBR make this easy

  2. Reactor BR2

    International Nuclear Information System (INIS)

    The BR2 reactor is still SCK-CEN's most important nuclear facility. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. Various aspects concerning the operation of the BR2 Reactor, the utilisation of the CALLISTO loop and the irradiation programme, the BR2 R and D programme and the production of isotopes and of NTD-silicon are discussed. Progress and achievements in 1999 are reported

  3. TRIGA reactor characteristics

    International Nuclear Information System (INIS)

    This module describes the general design, characteristics and parameters of TRIGA reactors and fuels. It is recommended that most of this information should be incorporated into any reactor operator training program and, in many cases, the facility Safety Analysis Report. It is oriented to teach the basics of the physics and mechanical design of the TRIGA fuel as well as its unique operational characteristics and the differences between TRIGA fuels and others more traditional reactor fuels. (nevyjel)

  4. Reactor Safety Analysis

    International Nuclear Information System (INIS)

    The objective of SCK-CEN's programme on reactor safety is to develop expertise in probabilistic and deterministic reactor safety analysis. The research programme consists of four main activities, in particular the development of software for reliability analysis of large systems and participation in the international PHEBUS-FP programme for severe accidents, the development of an expert system for the aid to diagnosis; the development and application of a probabilistic reactor dynamics method. Main achievements in 1999 are reported

  5. Reactor Engineering Department annual report

    International Nuclear Information System (INIS)

    Research and development activities in the Department of Reactor Engineering in fiscal 1984 are described. The work of the Department is closely related to development of multipurpose Very High Temperature Gas Cooled Reactor and Fusion Reactor, and development of Liquid Metal Fast Breeder Reactor carried out by Power Reactor and Nuclear Fuel Development Corporation. Contents of the report are achievements in fields such as nuclear data and group constants, theoretical method and code development, reactor physics experiment and analysis, fusion neutronics, shielding, reactor and nuclear instrumentation, reactor control and diagnosis, safeguards technology, and activities of the Committee on Reactor Physics. (author)

  6. Reactor Engineering Division annual report

    International Nuclear Information System (INIS)

    Research and development activities in the Division of Reactor Engineering in fiscal 1981 are described. The work of the Division is closely related to development of multipurpose Very High Temperature Gas Cooled Reactor and fusion reactor, and development of Liquid Metal Fast Breeder Reactor carried out by Power Reactor and Nuclear Fuel Development Corporation. Contents of the report are achievements in fields such as nuclear data and group constants, theoretical method and code development, integral experiment and analysis, shielding, reactor and nuclear instrumentation, reactor control and diagnosis, and fusion reactor technology, and activities of the Committee on Reactor Physics. (author)

  7. Reactor Engineering Division annual report

    International Nuclear Information System (INIS)

    Research activities in the Division of Reactor Engineering in fiscal 1979 are described. The work of the Division is closely related to development of multi-purpose Very High Temperature Gas Cooled Reactor and fusion reactor, and development of Liquid Metal Fast Breeder Reactor carried out by Power Reactor and Nuclear Fuel Development Corporation. Contents of the report are achievements in fields such as nuclear data and group constants, theoretical method and code development, integral experiment and analysis, shielding, reactor and nuclear instrumentation, reactor control and diagnosis, and fusion reactor technology, and activities of the Committees on Reactor Physics and on Decomissioning of Nuclear Facilities. (author)

  8. New reactor concepts

    International Nuclear Information System (INIS)

    The document gives a summary of new nuclear reactor concepts from a technological point of view. Belgium supports the development of the European Pressurized-Water Reactor, which is an evolutionary concept based on the European experience in Pressurized-Water Reactors. A reorientation of the Belgian choice for this evolutionary concept may be required in case that a decision is taken to burn plutonium, when the need for flexible nuclear power plants arises or when new reactor concepts can demonstrate proved benefits in terms of safety and cost

  9. Reactor construction steels

    International Nuclear Information System (INIS)

    The basic functions of light water reactor components are shown on the example of a pressurized water reactor and the requirements resulting therefrom for steel, the basic structural material, are derived. A detailed analysis of three main groups of reactor steels is presented and the applications are indicated of low-alloyed steels, high-alloyed austenitic steels, and steels with a high content of Ni and of alloying additions for steam generator pipes. An outline is given of prospective fast breeder reactor steels. (J.K.)

  10. Commercialization of fast reactors

    International Nuclear Information System (INIS)

    Comparative analysis has been performed of capital and fuel cycle costs for fast BN-type and pressurized light water VVER-type reactors. As a result of materials demand and components costs comparison of NPPs with VVER-1000 and BN-600 reactors, respectively, conclusion was made, that under equal conditions of the comparison, NPP with fast reactor had surpassed the specific capital cost of NPP with VVER by about 30 - 40 %. Ways were determined for further decrease of this difference, as well as for the fuel cycle cost reduction, because at present it is higher than that of VVER-type reactors. (author)

  11. Mirror fusion reactors

    International Nuclear Information System (INIS)

    Conceptual design studies were made of fusion reactors based on the three current mirror-confinement concepts: the standard mirror, the tandem mirror, and the field-reversed mirror. Recent studies of the standard mirror have emphasized its potential as a fusion-fission hybrid reactor, designed to produce fuel for fission reactors. We have designed a large commercial hybrid and a small pilot-plant hybrid based on standard mirror confinement. Tandem mirror designs include a commercial 1000-MWe fusion power plant and a nearer term tandem mirror hybrid. Field-reversed mirror designs include a multicell commercial reactor producing 75 MWe and a single-cell pilot plant

  12. Natural convection type reactor

    International Nuclear Information System (INIS)

    In a natural convection type nuclear reactor, a reactor core is disposed such that the top of the reactor core is always situated in a flooded position even if pipelines connected to the pressure vessel are ruptured and the level at the inside of the reactor vessel is reduced due to flashing. Further, a lower dry well situated below the pressure vessel is disposed such that it is in communication with a through hole to a pressure suppression chamber situated therearound and the reactor core is situated at the level lower than that of the through hole. If pipelines connected to the pressure vessel are ruptured to cause loss of water, although the water level is lowered after the end of the flashing, the reactor core is always flooded till the operation of a pressure accummulation water injection system to prevent the top of the reactor core even from temporary exposure. Further, injected water is discharged to the outside of the pressure vessel, transferred to the lower dry well, and flows through the through hole to the pressure control chamber and cools the surface of the reactor pressure vessel from the outside. Accordingly, the reactor core is cooled to surely and efficiently remove the after-heat. (N.H.)

  13. INVAP's Research Reactor Designs

    International Nuclear Information System (INIS)

    INVAP, an Argentine company founded more than three decades ago, is today recognized as one of the leaders within the research reactor industry. INVAP has participated in several projects covering a wide range of facilities, designed in accordance with the requirements of our different clients. For complying with these requirements, INVAP developed special skills and capabilities to deal with different fuel assemblies, different core cooling systems, and different reactor layouts. This paper summarizes the general features and utilization of several INVAP research reactor designs, from subcritical and critical assemblies to high-power reactors IAEA safety

  14. Reactor power control device

    International Nuclear Information System (INIS)

    The present invention provides a control device which can conduct scram and avoid lowering of the power of a nuclear power plant upon occurrence of earthquakes. Namely, the device of the present invention comprises, in addition to an existent power control device, (1) an earthquake detector for detecting occurrence and annihilation of earthquakes and (2) a reactor control device for outputting control rod operation signals and reactor core flow rate control signals depending on the earthquake detection signals from the detector, and reactor and plant information. With such a constitution, although the reactor is vibrated by earthquakes, the detector detects slight oscillations of the reactor by initial fine vibration waves as premonitory symptoms of serious earthquakes. The earthquake occurrence signals are outputted to the reactor control device. The reactor control device, receiving the signals, changes the position of control rods by way of control rod driving mechanisms to make the axial power distribution in the reactor core to a top peak type. As a result, even if the void amount in the reactor core is reduced by the subsequent actual earthquakes, since the void amount is moved, effects on the increase of neutron fluxes by the actual earthquakes is small. (I.S.)

  15. Nuclear reactor internals arrangement

    International Nuclear Information System (INIS)

    A nuclear reactor internals arrangement is disclosed which facilitates reactor refueling. A reactor vessel and a nuclear core is utilized in conjunction with an upper core support arrangement having means for storing withdrawn control rods therein. The upper core support is mounted to the underside of the reactor vessel closure head so that upon withdrawal of the control rods into the upper core support, the closure head, the upper core support and the control rods are removed as a single unit thereby directly exposing the core for purposes of refueling

  16. Fusion Reactor Materials

    International Nuclear Information System (INIS)

    The objective of SCK-CEN's programme on fusion reactor materials is to contribute to the knowledge on the radiation-induced behaviour of fusion reactor materials and components as well as to help the international community in building the scientific and technical basis needed for the construction of the future reactor. Ongoing projects include: the study of the mechanical and chemical (corrosion) behaviour of structural materials under neutron irradiation and water coolant environment; the investigation of the characteristics of irradiated first wall material such as beryllium; investigations on the management of materials resulting from the dismantling of fusion reactors including waste disposal. Progress and achievements in these areas in 2001 are discussed

  17. "Barn lär sig så mycket för dem är som små svampar" : Förskollärares uppfattningar om matematik i förskolan

    OpenAIRE

    Södergren, Anna-Carin

    2015-01-01

    Studiens övergripande syfte är att undersöka vika uppfattningar förskollärare har om barns möte med matematik i förskolan och hur det kommer till utryck i deras arbete samt undersöka hur förskolans läroplan Lpfö 98 reviderad 2010 finns med i deras arbete. Studien är gjord med utgångspunkt ur ett fenomenografiskt perspektiv och studien bygger på kvalitativa intervjuer från fem förskollärare från fem olika förskolor. Sammanfattningsvis visar resultatet på att förskollärare uppfattar att barn i ...

  18. Och vad är lustfyllt lärande? : En fenomenologiskt inspirerad studie om barn och elevers uppfattningar av lustfyllt lärande i förskola och skola.

    OpenAIRE

    Lilja, Lina; Thilén, Johanna

    2013-01-01

    I denna studie undersöktes förskolebarn och skolbarns uppfattningar av lustfyllt lärande. Fokus i tidigare forskning kring ämnet har främst legat på att utgå från lärares uppfattningar, men denna studie har riktat in sig på barns perspektiv av lustfyllt lärande. En fenomenologiskt inspirerad metod har tillämpats för att nå syftet, som är att utforska och beskriva det essentiella i barn och elevers uppfattningar av att känna motivation och lust till lärande. Vi ville också försöka förstå hur t...

  19. Vad påverkar föräldrars sätt att tillgodose barns behov av regelbundet umgänge? : En applikation på Theory of Planned Behaviour

    OpenAIRE

    Herbertsson, Carina

    2007-01-01

    Föreliggande undersökning var en attitydundersökning baserad på Theory of Planned Behaviour där attityd, subjektiv norm, upplevd kontroll samt intention anses kunna predicera beteende. Syftet med undersökningen är försöka ta reda på vilka faktorer som påverkar hur mycket tid man som förälder umgås med sina barn efter en separation eller skilsmässa eftersom många barn i den situationen förlorar kontakten med den ena föräldern. 36 försöksdeltagare besvarade ett frågeformulär bestående av 31 frå...

  20. "Kan vi köpa den bilen, mamma?" : En studie om hur föräldrar upplever att deras barn påverkas av tevereklam

    OpenAIRE

    Ulvenfalk, Daniel; Larsson, Anton

    2014-01-01

    I dagens konsumtionssamhälle bombarderas tevepubliken ständigt med reklamfilmer om olika produkter och tjänster. Trots ett konvergerande medielandskap med en uppsjö nya teknologiska innovationer har televisionen bevarat sin starka ställning i de svenska folkhemmen och är fortfarande det mest frekvent använda mediet bland barn.  Med gemensamt intresse för reklam och dess påverkan som utgångsläge förde Piagets teori om barnets kognitiva utveckling oss in på att närmare undersöka hur barn påverk...

  1. The research reactors their contribution to the reactors physics

    International Nuclear Information System (INIS)

    The 19 october 2000, the french society of nuclear energy organized a day on the research reactors. This associated report of the technical session, reactors physics, is presented in two parts. The first part deals with the annual meeting and groups general papers on the pressurized water reactors, the fast neutrons reactors and the fusion reactors industry. The second part presents more technical papers about the research programs, critical models, irradiation reactors (OSIRIS and Jules Horowitz) and computing tools. (A.L.B.)

  2. Comparison between barn owl pellet and fox scat analysis in small mammal survey / Analisi di borre di barbagianni e di feci di volpe: confronto tra due metodologie per il rilevamento di piccoli mammiferi

    OpenAIRE

    Paolo Agnelli; Anna De Marinis

    1993-01-01

    Abstract In the course of a small mammal survey 100 barn owl (Tyto alba Scop.) pellets and 50 fox (Vulpes vulpes L.) scats were collected at "Villa Demidoff Park" (Florence, Italy) during six weekly samp1ings in the spring. Scat and pellet analyses were compared in order to point out advantages and disadvantages of these techniques as a tool in small mammal surveys. Riassunto In uno studio s...

  3. One piece reactor removal

    International Nuclear Information System (INIS)

    Japan Research Reactor No.3 (JRR-3) was the first reactor consisting of 'Japanese-made' components alone except for fuel and heavy water. After reaching its initial critical state in September 1962, JRR-3 had been in operation for 21 years until March 1983. It was decided that the reactor be removed en-bloc in view of the work schedule, cost and management of the reactor following the removal. In the special method developed jointly by the Japanese Atomic Energy Research Institute and Shimizu Construction Co., Ltd., the reactor main unit was cut off from the building by continuous core boring, with its major components bound in the block with biological shield material (heavy concrete), and then conveyed and stored in a large waste store building constructed near the reactor building. Major work processes described in this report include the cutting off, lifting, horizontal conveyance and lowering of the reactor main unit. The removal of the JRR-3 reactor main unit was successfully carried out safely and quickly by the en-block removal method with radiation exposure dose of the workers being kept at a minimum. Thus the high performance of the en-bloc removal method was demonstrated and, in addition, valuable knowhow and other data were obtained from the work. (Nogami, K.)

  4. Reactor Materials Research

    International Nuclear Information System (INIS)

    The activities of the Reactor Materials Research Department of the Belgian Nuclear Research Centre SCK-CEN in 2000 are summarised. The programmes within the department are focussed on studies concerning (1) fusion, in particular mechanical testing; (2) Irradiation Assisted Stress Corrosion Cracking (IASCC); (3) nuclear fuel; and (4) Reactor Pressure Vessel Steel (RPVS)

  5. The fusion reactor

    International Nuclear Information System (INIS)

    Basic principles of the fusion reactor are outlined. Plasma heating and confinement schemes are described. These confinement systems include the linear Z pinch, magnetic mirrors and Tokamaks. A fusion reactor is described and a discussion is given of its environmental impact and its fuel situation. (R.L.)

  6. Polymerization Reactor Engineering.

    Science.gov (United States)

    Skaates, J. Michael

    1987-01-01

    Describes a polymerization reactor engineering course offered at Michigan Technological University which focuses on the design and operation of industrial polymerization reactors to achieve a desired degree of polymerization and molecular weight distribution. Provides a list of the course topics and assigned readings. (TW)

  7. Reactor Materials Research

    Energy Technology Data Exchange (ETDEWEB)

    Van Walle, E

    2001-04-01

    The activities of the Reactor Materials Research Department of the Belgian Nuclear Research Centre SCK-CEN in 2000 are summarised. The programmes within the department are focussed on studies concerning (1) fusion, in particular mechanical testing; (2) Irradiation Assisted Stress Corrosion Cracking (IASCC); (3) nuclear fuel; and (4) Reactor Pressure Vessel Steel (RPVS)

  8. Gas-cooled reactors

    International Nuclear Information System (INIS)

    The present study is the second part of a general survey of Gas Cooled Reactors (GCRs). In this part, the course of development, overall performance and present development status of High Temperature Gas Cooled Reactors (HTCRs) and advances of HTGR systems are reviewed. (author)

  9. Light water reactor program

    Energy Technology Data Exchange (ETDEWEB)

    Franks, S.M.

    1994-12-31

    The US Department of Energy`s Light Water Reactor Program is outlined. The scope of the program consists of: design certification of evolutionary plants; design, development, and design certification of simplified passive plants; first-of-a-kind engineering to achieve commercial standardization; plant lifetime improvement; and advanced reactor severe accident program. These program activities of the Office of Nuclear Energy are discussed.

  10. Reactor Safety Analysis

    International Nuclear Information System (INIS)

    The objective of SCK-CEN's programme on reactor safety is to develop expertise in probabilistic and deterministic reactor safety analysis. The research programme consists of two main activities, in particular the development of software for reliability analysis of large systems and participation in the international PHEBUS-FP programme for severe accidents. Main achievements in 1999 are reported

  11. Light water type reactor

    International Nuclear Information System (INIS)

    The nuclear reactor of the present invention prevents disruption of a reactor core even in a case of occurrence of entire AC power loss event, and even if a reactor core disruption should occur, it prevents a rupture of the reactor container due to excess heating. That is, a high pressure water injection system and a low pressure water injection system operated by a diesel engine are disposed in the reactor building in addition to an emergency core cooling system. With such a constitution, even if an entire AC power loss event should occur, water can surely be injected to the reactor thereby enabling to prevent the rupture of the reactor core. Even if it should be ruptured, water can be sprayed to the reactor container by the low pressure water injection system. Further, if each of water injection pumps of the high pressure water injection system and the low pressure water injection system can be driven also by motors in addition to the diesel engine, the pump operation can be conducted more certainly and integrally. (I.S.)

  12. Naval propulsion reactors

    International Nuclear Information System (INIS)

    This article deals with the design and exploitation of naval propulsion reactors, mainly of PWR-type. The other existing or conceivable types of reactors are also presented: 1 - specificities of nuclear propulsion (integration in the ship, marine environment, maneuverability, instantaneous availability, conditions of exploitation-isolation, nuclear safety, safety authority); 2 - PWR-type reactor (stable operation, mastered technology, general design, radiation protection); 3 - other reactor types; 4 - compact or integrated loops architecture; 5 - radiation protection; 6 - reactor core; 7 - reactivity control (core lifetime, control means and mechanisms); 8 - core cooling (natural circulation, forced circulation, primary flow-rate program); 9 - primary loop; 10 - pressurizer; 11 - steam generators and water-steam secondary loop; 12 - auxiliary and safety loops; 13 - control instrumentation; 14 - operation; 15 - nuclear wastes and dismantling. (J.S.)

  13. Iris reactor conceptual design

    International Nuclear Information System (INIS)

    IRIS (International Reactor Innovative and Secure) is a modular, integral, light water cooled, low-to-medium power (100-350 MWe) reactor which addresses the requirements defined by the US DOE for Generation IV reactors, i.e., proliferation resistance, enhanced safety, improved economics and fuel cycle sustainability. It relies on the proven technology of light water reactors and features innovative engineering, but it does not require new technology development. This paper discusses the current reference IRIS design, which features a 1000 MWt thermal core with proven 5%-enriched uranium oxide fuel and five-year long straight burn fuel cycle, integral reactor vessel housing helical tube steam generators and immersed spool pumps. Other major contributors to the high level of safety and economic attractiveness are the safety by design and optimized maintenance approaches, which allow elimination of some classes of accidents, lower capital cost, long operating cycle, and high capacity factors. (author)

  14. Research reactor DHRUVA

    International Nuclear Information System (INIS)

    DHRUVA, a 100 MWt research reactor located at the Bhabha Atomic Research Centre, Bombay, attained first criticality during August, 1985. The reactor is fuelled with natural uranium and is cooled, moderated and reflected by heavy water. Maximum thermal neutron flux obtained in the reactor is 1.8 X 1014 n/cm2/sec. Some of the salient design features of the reactor are discussed in this paper. Some important features of the reactor coolant system, regulation and protection systems and experimental facilities are presented. A short account of the engineered safety features is provided. Some of the problems that were faced during commissioning and the initial phase of power operation are also dealt upon

  15. Reactor core monitoring method

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Michitsugu [Tokyo Electric Power Co., Inc. (Japan); Kanemoto, Shigeru; Enomoto, Mitsuhiro; Ebata, Shigeo

    1998-05-06

    The present invention provides a method of monitoring the state of coolant flow in a reactor of a BWR power plant. Namely, a plurality of local power region monitors (LPRM) are disposed to the inside of the reactor core for monitoring a power distribution. Signals of at least two optional LPRM detectors situated at positions different in axial or radial positions of the reactor core are obtained. General fluctuation components which nuclear hydrothermally fluctuate in overall reactor core are removed from the components of the signals. Then, correlational functions between these signals are determined. The state of coolant flow in the reactor is monitored based on the correlational function. When the axial flowing rate and radial flow interference are monitored, the accuracy upon monitoring axial and radial local behaviors of coolants can be improved by thus previously removing the general fluctuation components from signals of LPRM detectors and extracting local void information near to LPRM detectors at high accuracy. (I.S.)

  16. Physics of nuclear reactors

    International Nuclear Information System (INIS)

    This manual covers all the aspects of the science of neutron transport in nuclear reactors and can be used with great advantage by students, engineers or even reactor experts. It is composed of 18 chapters: 1) basis of nuclear physics, 2) the interactions of neutrons with matter, 3) the interactions of electromagnetic radiations and charged-particles with matter, 4) neutron slowing-down, 5) resonant absorption, 6) Doppler effect, 7) neutron thermalization, 8) Boltzmann equation, 9) calculation methods in neutron transport theory, 10) neutron scattering, 11) reactor reactivity, 12) theory of the critical homogenous pile, 13) the neutron reflector, 14) the heterogeneous reactor, 15) the equations of the fuel cycle, 16) neutron counter-reactions, 17) reactor kinetics, and 18) calculation methods in neutron scattering

  17. Mirror reactor surface study

    International Nuclear Information System (INIS)

    A general survey is presented of surface-related phenomena associated with the following mirror reactor elements: plasma first wall, ion sources, neutral beams, director converters, vacuum systems, and plasma diagnostics. A discussion of surface phenomena in possible abnormal reactor operation is included. Several studies which appear to merit immediate attention and which are essential to the development of mirror reactors are abstracted from the list of recommended areas for surface work. The appendix contains a discussion of the fundamentals of particle/surface interactions. The interactions surveyed are backscattering, thermal desorption, sputtering, diffusion, particle ranges in solids, and surface spectroscopic methods. A bibliography lists references in a number of categories pertinent to mirror reactors. Several complete published and unpublished reports on surface aspects of current mirror plasma experiments and reactor developments are also included

  18. FBR type reactor

    International Nuclear Information System (INIS)

    A circular neutron reflector is disposed vertically movably so as to surround the outer circumference of a reactor core barrel. A reflector driving device comprises a driving device main body attracted to the outer wall surface of the reactor barrel by electromagnetic attraction force and an inertia body disposed above the driving device main body vertically movably. A reflector is connected below the reactor driving device. At the initial stage, a spontaneous large current is supplied to upper electromagnetic repulsion coils of the reflector driving device, impact electromagnetic repulsion force is caused between the inertia body and the reflector driving device, so that the driving device main body moves downwardly by a predetermined distance and stopped. The reflector driving device can be lowered in a step-like manner to an appropriate position suitable to restart the reactor during stoppage of the reactor core by conducting spontaneous supply of current repeatedly to the upper electromagnetic repulsion coils. (I.N.)

  19. TRIGA research reactors

    International Nuclear Information System (INIS)

    TRIGA (Training, Research, Isotope production, General-Atomic) has become the most used research reactor in the world with 65 units operating in 24 countries. The original patent for TRIGA reactors was registered in 1958. The success of this reactor is due to its inherent level of safety that results from a prompt negative temperature coefficient. Most of the neutron moderation occurs in the nuclear fuel (UZrH) because of the presence of hydrogen atoms, so in case of an increase of fuel temperature, the neutron spectrum becomes harder and neutrons are less likely to fission uranium nuclei and as a consequence the power released decreases. This inherent level of safety has made this reactor fit for training tool in university laboratories. Some recent versions of TRIGA reactors have been designed for medicine and industrial isotope production, for neutron therapy of cancers and for providing a neutron source. (A.C.)

  20. Status of French reactors

    Energy Technology Data Exchange (ETDEWEB)

    Ballagny, A. [Commissariat a l`Energie Atomique, Saclay (France)

    1997-08-01

    The status of French reactors is reviewed. The ORPHEE and RHF reactors can not be operated with a LEU fuel which would be limited to 4.8 g U/cm{sup 3}. The OSIRIS reactor has already been converted to LEU. It will use U{sub 3}Si{sub 2} as soon as its present stock of UO{sub 2} fuel is used up, at the end of 1994. The decision to close down the SILOE reactor in the near future is not propitious for the start of a conversion process. The REX 2000 reactor, which is expected to be commissioned in 2005, will use LEU (except if the fast neutrons core option is selected). Concerning the end of the HEU fuel cycle, the best option is reprocessing followed by conversion of the reprocessed uranium to LEU.

  1. Nuclear reactor design

    CERN Document Server

    2014-01-01

    This book focuses on core design and methods for design and analysis. It is based on advances made in nuclear power utilization and computational methods over the past 40 years, covering core design of boiling water reactors and pressurized water reactors, as well as fast reactors and high-temperature gas-cooled reactors. The objectives of this book are to help graduate and advanced undergraduate students to understand core design and analysis, and to serve as a background reference for engineers actively working in light water reactors. Methodologies for core design and analysis, together with physical descriptions, are emphasized. The book also covers coupled thermal hydraulic core calculations, plant dynamics, and safety analysis, allowing readers to understand core design in relation to plant control and safety.

  2. Compact torsatron reactors

    International Nuclear Information System (INIS)

    Low-aspect-ratio torsatron configurations could lead to compact stellarator reactors with R0 = 8--11m, roughly one-half to one-third the size of more conventional stellarator reactor designs. Minimum-size torsatron reactors are found using various assumptions. Their size is relatively insensitive to the choice of the conductor parameters and depends mostly on geometrical constraints. The smallest size is obtained by eliminating the tritium breeding blanket under the helical winding on the inboard side and by reducing the radial depth of the superconducting coil. Engineering design issues and reactor performance are examined for three examples to illustrate the feasibility of this approach for compact reactors and for a medium-size (R0 ≅ 4 m,/bar a/ /approx lt/ 1 m) copper-coil ignition experiment. 26 refs., 11 figs., 7 tabs

  3. Multi-purpose reactor

    International Nuclear Information System (INIS)

    The Multi-Purpose-Reactor (MPR), is a pool-type reactor with an open water surface and variable core arrangement. Its main feature is plant safety and reliability. Its power is 22MWth, cooled by light water and moderated by beryllium. It has platetype fuel elements (MTR type, approx. 20%. enriched uranium) clad in aluminium. Its cobalt (Co60) production capacity is 50000 Ci/yr, 200Ci/gr. The distribution of the reactor core and associated control and safety systems is essentially based on the following design criteria: - upwards cooling flow, to waive the need for cooling flow inversion in case the reactor is cooled by natural convection if confronted with a loss of pumping power, and in order to establish a superior heat transfer potential (a higher coolant saturation temperature); - easy access to the reactor core from top of pool level with the reactor operating at full power, in order to facilitate actual implementation of experiments. Consequently, mechanisms associated to control and safety rods s,re located underneath the reactor tank; - free access of reactor personnel to top of pool level with the reactor operating at full power. This aids in the training of personnel and the actual carrying out of experiments, hence: - a vast water column was placed over the core to act as radiation shielding; - the core's external area is cooled by a downwards flow which leads to a decay tank beyond the pool (for N16 to decay); - a small downwards flow was directed to stream downwards from above the reactor core in order to drag along any possibly active element; and - a stagnant hot layer system was placed at top of pool level so as to minimize the upwards coolant flow rising towards pool level

  4. The CAREM reactor and present currents in reactor design

    International Nuclear Information System (INIS)

    INVAP has been working on the CAREM project since 1983. It concerns a very low power reactor for electrical energy generation. The design of the reactor and the basic criteria used were described in 1984. Since then, a series of designs have been presented for reactors which are similar to CAREM regarding the solutions presented to reduce the chance of major nuclear accidents. These designs have been grouped under different names: Advanced Reactors, Second Generation Reactors, Inherently Safe Reactors, or even, Revolutionary Reactors. Every reactor fabrication firm has, at least, one project which can be placed in this category. Presently, there are two main currents of Reactor Design; Evolutionary and Revolutionary. The present work discusses characteristics of these two types of reactors, some revolutionary designs and common criteria to both types. After, these criteria are compared with CAREM reactor design. (Author)

  5. Den komplexa väven Att organisera för barns övergångar till och från förskoleklass

    Directory of Open Access Journals (Sweden)

    Helena Ackesjö

    2015-09-01

    Full Text Available This study focuses on how children's transitions to and from preschool classes are organized in different schools. Principal’s arguments for this organization were sought via a web-based survey and analyzed using the frame factor theory in addition to theories of practical sense and the concept of continuity. The results show that children tend to make more transitions between social communities the younger they are. The distribution of the principal’s answers show that the majority of them, because of external conditions, split the preschool groups to new classes in the transition to preschool class. However, the same movements are not indicated in the transition to first grade. The results show how the work of organizing chidren’s transitions represent a complex web of external actual conditions as the number of children and the recruitment area of the school, the internal logics and ideas about what is best for children and best for continued learning as well as the school's own traditions of working with transitions. Föreliggande studie fokuserar på hur barns övergångar till och från förskoleklass organiseras på olika skolor. Via en webbaserad enkät söks skolledares argument för denna organisering. I analysen nyttjas ett ramfaktorteoretiskt tänkande som kompletteras med teorier om praktiskt förnuft samt kontinuitetsbegreppet. Resultaten visar att barn tenderar att göra fler övergångar mellan barngrupper och sociala gemenskaper ju yngre de är. Fördelningen av skolledarnas svar visar att majoriteten, på grund av yttre villkor, delar förskolegrupperna till nya klasser i övergången till förskoleklass. Däremot indikeras inte samma rörlighet i övergången till årskurs 1. Resultaten visar hur arbetet med att organisera övergångarna utgör en komplex väv av yttre faktiska villkor som barnantal och upptagningsområdets storlek, av inre logiker och föreställningar om vad som är det bästa för barnen och det b

  6. Improvements of sound localization abilities by the facial ruff of the barn owl (Tyto alba as demonstrated by virtual ruff removal.

    Directory of Open Access Journals (Sweden)

    Laura Hausmann

    Full Text Available BACKGROUND: When sound arrives at the eardrum it has already been filtered by the body, head, and outer ear. This process is mathematically described by the head-related transfer functions (HRTFs, which are characteristic for the spatial position of a sound source and for the individual ear. HRTFs in the barn owl (Tyto alba are also shaped by the facial ruff, a specialization that alters interaural time differences (ITD, interaural intensity differences (ILD, and the frequency spectrum of the incoming sound to improve sound localization. Here we created novel stimuli to simulate the removal of the barn owl's ruff in a virtual acoustic environment, thus creating a situation similar to passive listening in other animals, and used these stimuli in behavioral tests. METHODOLOGY/PRINCIPAL FINDINGS: HRTFs were recorded from an owl before and after removal of the ruff feathers. Normal and ruff-removed conditions were created by filtering broadband noise with the HRTFs. Under normal virtual conditions, no differences in azimuthal head-turning behavior between individualized and non-individualized HRTFs were observed. The owls were able to respond differently to stimuli from the back than to stimuli from the front having the same ITD. By contrast, such a discrimination was not possible after the virtual removal of the ruff. Elevational head-turn angles were (slightly smaller with non-individualized than with individualized HRTFs. The removal of the ruff resulted in a large decrease in elevational head-turning amplitudes. CONCLUSIONS/SIGNIFICANCE: The facial ruff a improves azimuthal sound localization by increasing the ITD range and b improves elevational sound localization in the frontal field by introducing a shift of iso-ILD lines out of the midsagittal plane, which causes ILDs to increase with increasing stimulus elevation. The changes at the behavioral level could be related to the changes in the binaural physical parameters that occurred after the

  7. Reactor Engineering Division annual report

    International Nuclear Information System (INIS)

    Research activities in the Division of Reactor Engineering in fiscal 1977 are described. Works of the Division are development of multi-purpose Very High Temperature Gas Cooled Reactor, fusion reactor engineering, and development of Liquid Metal Fast Breeder Reactor for Power Reactor and Nuclear Fuel Development Corporation. Contents of the report are nuclear data and group constants, theoretical method and code development, integral experiment and analysis, shielding, heat transfer and fluid dynamics, reactor and nuclear instrumentation, dynamics analysis and control method development, fusion reactor technology, and Committee on Reactor Physics. (Author)

  8. Reactor Engineering Department annual report

    International Nuclear Information System (INIS)

    Research and development activities in the Department of Reactor Engineering in fiscal 1983 are described. The work of the Department is closely related to development of multipurpose Very High Temperature Gas Cooled Reactor and Fusion Reactor, and development of Liquid Metal Fast Breeder Reactor carried out by Power Reactor and Nuclear Fuel Development Corporation. Contents of the report are achievements in fields such as nuclear data and group constants, theoretical method and code development, integral experiment and analysis, fusion neutronics, shielding, reactor and nuclear instrumentation, reactor control and diagnosis, and safeguards technology, and activities of the Committee on Reactor Physics. (author)

  9. Reactor Engineering Division annual report

    International Nuclear Information System (INIS)

    Research activities conducted in Reactor Engineering Division in fiscal 1975 are summarized in this report. Works in the division are closely related to the development of multi-purpose High-temperature Gas Cooled Reactor, the development of Liquid Metal Fast Breeder Reactor by Power Reactor and Nuclear Fuel Development Corporation, and engineering research of thermonuclear fusion reactor. Many achievements are described concerning nuclear data and group constants, theoretical method and code development, integral experiment and analysis, shielding, heat transfer and fluid dynamics, reactor and nuclear instrumentation, dynamics analysis and control method development, fusion reactor technology and activities of the Committee on Reactor Physics. (auth.)

  10. Cross sections for fuel depletion and radioisotope production calculations in TRIGA reactors

    International Nuclear Information System (INIS)

    For TRIGA Reactors, the fuel depletion and isotopic inventory calculations, depends on the computer code and in the cross sections of some important actinides used. Among these we have U-235, U-238, Pu-239, Pu-240 and Pu-241. We choose ORIGEN2, a code with a good reputation in this kind of calculations, we observed the cross sections for these actinides in the libraries that we have (PWR's and BWR), the fission cross section for U-235 was about 50 barns. We used a PWR library and our results were not satisfactory, specially for standard elements. We decided to calculate cross sections more suitable for our reactor, for that purpose we simulate the standard and FLIP TRIGA cells with the transport code WIMS. We used the fuel average flux and COLAPS (a home made program), to generate suitable cross sections for ORIGEN2, by collapsing the WIMS library cross sections of these nuclides. For the radioisotope production studies using the Central Thimble, we simulate the A and B rings and used the A average flux to collapse cross sections. For these studies, the required nuclides sometimes are not present in WIMS library, for them we are planning to process the ENDF/B data, with NJOY system, and include the cross sections to WIMS library or to collapse them using the appropriate average-flux and the program COLAPS. (author)

  11. Reactor performance calculations for water reactors

    International Nuclear Information System (INIS)

    The principles of nuclear, thermal and hydraulic performance calculations for water cooled reactors are discussed. The principles are illustrated by describing their implementation in the UKAEA PATRIARCH scheme of computer codes. This material was originally delivered as a course of lectures at the Technical University of Helsinki in Summer of 1969.

  12. Fourth Generation Reactor Concepts

    International Nuclear Information System (INIS)

    Concerns over energy resources availability, climate changes and energy supply security suggest an important role for nuclear energy in future energy supplies. So far nuclear energy evolved through three generations and is still evolving into new generation that is now being extensively studied. Nuclear Power Plants are producing 16% of the world's electricity. Today the world is moving towards hydrogen economy. Nuclear technologies can provide energy to dissociate water into oxygen and hydrogen and to production of synthetic fuel from coal gasification. The introduction of breeder reactors would turn nuclear energy from depletable energy supply into an unlimited supply. From the early beginnings of nuclear energy in the 1940s to the present, three generations of nuclear power reactors have been developed: First generation reactors: introduced during the period 1950-1970. Second generation: includes commercial power reactors built during 1970-1990 (PWR, BWR, Candu, Russian RBMK and VVER). Third generation: started being deployed in the 1990s and is composed of Advanced LWR (ALWR), Advanced BWR (ABWR) and Passive AP600 to be deployed in 2010-2030. Future advances of the nuclear technology designs can broaden opportunities for use of nuclear energy. The fourth generation reactors are expected to be deployed by 2030 in time to replace ageing reactors built in the 1970s and 1980s. The new reactors are to be designed with a view of the following objectives: economic competitiveness, enhanced safety, minimal radioactive waste production, proliferation resistance. The Generation IV International Forum (GIF) was established in January 2000 to investigate innovative nuclear energy system concepts. GIF members include Argentina, Brazil, Canada, Euratom, France Japan, South Africa, South Korea, Switzerland, United Kingdom and United States with the IAEA and OECD's NEA as permanent observers. China and Russia are expected to join the GIF initiative. The following six systems

  13. Safety of research reactors

    International Nuclear Information System (INIS)

    The number of research reactors that have been constructed worldwide for civilian applications is about 651. Of the reactors constructed, 284 are currently in operation, 258 are shut down and 109 have been decommissioned. More than half of all operating research reactors worldwide are over thirty years old. During this long period of time national priorities have changed. Facility ageing, if not properly managed, has a natural degrading effect. Many research reactors face concerns with the obsolescence of equipment, lack of experimental programmes, lack of funding for operation and maintenance and loss of expertise through ageing and retirement of the staff. Other reactors of the same vintage maintain effective ageing management programmes, conduct active research programmes, develop and retain high calibre personnel and make important contributions to society. Many countries that operate research reactors neither operate nor plan to operate power reactors. In most of these countries there is a tendency not to create a formal regulatory body. A safety committee, not always independent of the operating organization, may be responsible for regulatory oversight. Even in countries with nuclear power plants, a regulatory regime differing from the one used for the power plants may exist. Concern is therefore focused on one tail of a continuous spectrum of operational performance. The IAEA has been sending missions to review the safety of research reactors in Member States since 1972. Some of the reviews have been conducted pursuant to the IAEA' functions and responsibilities regarding research reactors that are operated within the framework of Project and Supply Agreements between Member States and the IAEA. Other reviews have been conducted upon request. All these reviews are conducted following procedures for Integrated Safety Assessment of Research Reactors (INSARR) missions. The prime objective of these missions has been to conduct a comprehensive operational safety

  14. Reactor Engineering Department annual report

    International Nuclear Information System (INIS)

    This report summarizes the research and development activities in the Department of Reactor Engineering during the fiscal year of 1992 (April 1, 1992-March 31, 1993). The major Department's programs promoted in the year are the assessment of the high conversion light water reactor, the design activities of advanced reactor system and development of a high energy proton linear accelerator for the engineering applications including TRU incineration. Other major tasks of the Department are various basic researches on the nuclear data and group constants, the developments of theoretical methods and codes, the reactor physics experiments and their analyses, fusion neutronics, radiation shielding, reactor instrumentation, reactor control/diagnosis, thermohydraulics and technology developments related to the reactor physics facilities. The cooperative works to JAERI's major projects such as the high temperature gas cooled reactor or the fusion reactor and to PNC's fast reactor project were also progressed. The activities of the Research Committee on Reactor Physics are also summarized. (author)

  15. Reactor engineering department annual report

    International Nuclear Information System (INIS)

    This report summarizes the research and development activities in the Department of Reactor Engineering during the fiscal year of 1989 (April 1, 1989 - March 31, 1990). One of major Department's programs is the assessment of the high conversion light water reactor and the design activities of advanced reactor system. Development of a high energy proton linear accelerator for the nuclear engineering including is also TRU incineration promoted. Other major tasks of the Department are various basic researches on nuclear data and group constants, theoretical methods and code development, on reactor physics experiments and analyses, fusion neutronics, radiation shielding, reactor instrumentation, reactor control/diagnosis, thermohydraulics, technology assessment of nuclear energy and technology developments related to the reactor physics facilities. The cooperative works to JAERI's major projects such as the high temperature gas cooled reactor or the fusion reactor and to PNC's fast reactor project also progressed. The activities of the Research Committee on Reactor Physics are also summarized. (author)

  16. Slurry reactor design studies

    Energy Technology Data Exchange (ETDEWEB)

    Fox, J.M.; Degen, B.D.; Cady, G.; Deslate, F.D.; Summers, R.L. (Bechtel Group, Inc., San Francisco, CA (USA)); Akgerman, A. (Texas A and M Univ., College Station, TX (USA)); Smith, J.M. (California Univ., Davis, CA (USA))

    1990-06-01

    The objective of these studies was to perform a realistic evaluation of the relative costs of tublar-fixed-bed and slurry reactors for methanol, mixed alcohols and Fischer-Tropsch syntheses under conditions where they would realistically be expected to operate. The slurry Fischer-Tropsch reactor was, therefore, operated at low H{sub 2}/CO ratio on gas directly from a Shell gasifier. The fixed-bed reactor was operated on 2.0 H{sub 2}/CO ratio gas after adjustment by shift and CO{sub 2} removal. Every attempt was made to give each reactor the benefit of its optimum design condition and correlations were developed to extend the models beyond the range of the experimental pilot plant data. For the methanol design, comparisons were made for a recycle plant with high methanol yield, this being the standard design condition. It is recognized that this is not necessarily the optimum application for the slurry reactor, which is being proposed for a once-through operation, coproducing methanol and power. Consideration is also given to the applicability of the slurry reactor to mixed alcohols, based on conditions provided by Lurgi for an Octamix{trademark} plant using their standard tubular-fixed reactor technology. 7 figs., 26 tabs.

  17. FBR type reactor

    International Nuclear Information System (INIS)

    The present invention provides an FBR type reactor in which the combustion of reactor core fuels is controlled by reflectors, and the position of a reflector driving device can be controlled even during shut down of the reactor. Namely, the reflector driving device is attracted to the outer wall surface of a reactor core barrel by electromagnetic attraction force. An inertia body is disposed vertically movably to the upper portion of the reflector driving device. Magnetic repulsive coils generate instantaneous magnetic repulsive force between the inertia body and the reflector driving device. With such a constitution, the reflector driving device can be driven by using magnetic repulsion of the electromagnetic repulsive coils and inertia of the inertia body. As a result, not only the reflectors can be elevated at an ultraslow speed during normal reactor operation, but also fine position adjustment for the reflector driving device, as well as fine position adjustment of the reflectors required upon restart of the reactor can be conducted by lowering the reflector driving device during shut down of the reactor. (I.S.)

  18. Reactor water sampling device

    International Nuclear Information System (INIS)

    The present invention concerns a reactor water sampling device for sampling reactor water in an in-core monitor (neutron measuring tube) housing in a BWR type reactor. The upper end portion of a drain pipe of the reactor water sampling device is attached detachably to an in-core monitor flange. A push-up rod is inserted in the drain pipe vertically movably. A sampling vessel and a vacuum pump are connected to the lower end of the drain pipe. A vacuum pump is operated to depressurize the inside of the device and move the push-up rod upwardly. Reactor water in the in-core monitor housing flows between the drain pipe and the push-up rod and flows into the sampling vessel. With such a constitution, reactor water in the in-core monitor housing can be sampled rapidly with neither opening the lid of the reactor pressure vessel nor being in contact with air. Accordingly, operator's exposure dose can be reduced. (I.N.)

  19. Test reactor technology

    International Nuclear Information System (INIS)

    The Reactor Development Program created a need for engineering testing of fuels and materials. The Engineering Test Reactors were developed around the world in response to this demand. The design of the test reactors proved to be different from that of power reactors, carrying the fuel elements closer to the threshold of failure, requiring more responsive instrumentation, more rapid control element action, and inherent self-limiting behavior under accident conditions. The design of the experimental facilities to exploit these reactors evolved a new, specialized, branch of engineering, requiring a very high-lvel scientific and engineering team, established a meticulous concern with reliability, the provision for recovery from their own failures, and detailed attention to possible interactions with the test reactors. This paper presents this technology commencing with the Materials Testing Reactor (MTR) through the Fast Flux Test Facility, some of the unique experimental facilities developed to exploit them, but discusses only cursorily the experiments performed, since sample preparation and sample analyses were, and to some extent still are, either classified or proprietary. The Nuclear Engineering literature is filled with this information

  20. Advanced reactor licensing issues

    International Nuclear Information System (INIS)

    In July 1986 the US Nuclear Regulatory Commission issued a Policy Statement on the Regulation of Advanced Nuclear Power Plants. As part of this policy advanced reactor designers were encouraged to interact with NRC early in the design process to obtain feedback regarding licensing requirements for advanced reactors. Accordingly, the staff has been interacting with the Department of Energy (DOE) and its contractors on the review of three advanced reactor conceptual designs: one modular High Temperature Gas-Cooled Reactor (MHTGR) and two Liquid Metal Reactors (LMRs). As a result of these interactions certain safety issues associated with these advanced reactor designs have been identified as key to the licensability of the designs as proposed by DOE. The major issues in this regard are: (1) selection and treatment of accident scenarios; (2) selection of siting source term; (3) performance and reliability of reactor shutdown and decay heat removal systems; (4) need for conventional containment; (5) need for conventional emergency evacuation; (6) role of the operator; (7) treatment of balance of plant; and (8) modular approach. This paper provides a status of the NRC review effort, describes the above issues in more detail and provides the current status and approach to the development of licensing guidance on each

  1. Nuclear reactor power monitor

    International Nuclear Information System (INIS)

    The device of the present invention monitors phenomena occurred in a nuclear reactor more accurately than usual case. that is, the device monitors a reactor power by signals sent from a great number of neutron monitors disposed in the reactor. The device has a means for estimating a phenomenon occurred in the reactor based on the relationship of a difference of signals between each of the great number of neutron monitors to the positions of the neutron monitors disposed in the reactor. The estimation of the phenomena is conducted by, for example, conversion of signals sent from the neutron monitors to a code train. Then, a phenomenon is estimated rapidly by matching the code train described above with a code train contained in a data base. Further. signals sent from the neutron monitors are processed statistically to estimate long term and periodical phenomena. As a result, phenomena occurred in the reactor are monitored more accurately than usual case, thereby enabling to improve reactor safety and operationability. (I.S.)

  2. Reactor Sharing Program

    International Nuclear Information System (INIS)

    Support utilization of the RINSC reactor for student and faculty instructions and research. The Department of Energy award has provided financial assistance during the period 9/29/1995 to 5/31/2001 to support the utilization of the Rhode Island Nuclear Science Center (RINSC) reactor for student and faculty instruction and research by non-reactor owning educational institutions within approximately 300 miles of Narragansett, Rhode Island. Through the reactor sharing program, the RINSC (including the reactor and analytical laboratories) provided reactor services and laboratory space that were not available to the other universities and colleges in the region. As an example of services provided to the users: Counting equipment, laboratory space, pneumatic and in-pool irradiations, demonstrations of sample counting and analysis, reactor tours and lectures. Funding from the Reactor Sharing Program has provided the RINSC to expand student tours and demonstration programs that emphasized our long history of providing these types of services to the universities and colleges in the area. The funding have also helped defray the cost of the technical assistance that the staff has routinely provided to schools, individuals and researchers who have called on the RINSC for resolution of problems relating to nuclear science. The reactor has been featured in a Public Broadcasting System documentary on Pollution in the Arctic and how a University of Rhode Island Professor used Neutron Activation Analysis conducted at the RINSC to discover the sources of the ''Arctic Haze''. The RINSC was also featured by local television on Earth Day for its role in environmental monitoring

  3. Determination of research reactor safety parameters by reactor calculations

    International Nuclear Information System (INIS)

    Main research reactor safety parameters such as power density peaking factors, shutdown margin and temperature reactivity coefficients are treated. Reactor physics explanation of the parameters is given together with their application in safety evaluation performed as part of research reactor operation. Reactor calculations are presented as a method for their determination assuming use of widely available computer codes. (author)

  4. Reactor de plasma

    OpenAIRE

    Erra Serrabasa, Pilar; Molina Mansilla, Ricardo; Beltrán Serra, Eric

    2008-01-01

    Reactor de plasma. Se trata de un reactor de plasma que puede trabajar en un amplio rango de presión, desde el vacío y presiones reducidas hasta la presión atmosférica y presiones superiores. Adicionalmente el reactor de plasma tiene la capacidad de regular otros parámetros importantes y permite su uso para el tratamiento de muestras de tipología muy diversa, como por ejemplo las de tamaño relativamente grande o de superficie rugosa.

  5. Integral nuclear reactor

    International Nuclear Information System (INIS)

    The invention deals with an inprovement of the design of an integral pressurized water nuclear reactor. A typical embodyment of the invention includes a generally cylindrical pressure vessel that is assembled from three segments which are bolted together at transverse joints to form a pressure tight unit that encloses the steam generator and the reactor. The new construction permits primary to secondary coolant heat exchange and improved control rod drive mecanisms which can be exposed for full service access during reactor core refueling, maintenance and inspection

  6. Microfluidic electrochemical reactors

    Science.gov (United States)

    Nuzzo, Ralph G.; Mitrovski, Svetlana M.

    2011-03-22

    A microfluidic electrochemical reactor includes an electrode and one or more microfluidic channels on the electrode, where the microfluidic channels are covered with a membrane containing a gas permeable polymer. The distance between the electrode and the membrane is less than 500 micrometers. The microfluidic electrochemical reactor can provide for increased reaction rates in electrochemical reactions using a gaseous reactant, as compared to conventional electrochemical cells. Microfluidic electrochemical reactors can be incorporated into devices for applications such as fuel cells, electrochemical analysis, microfluidic actuation, pH gradient formation.

  7. Licensed operating reactors

    International Nuclear Information System (INIS)

    The Operating Units Status Report --- Licensed Operating Reactors provides data on the operation of nuclear units as timely and accurately as possible. This information is collected by the Office of Information Resources Management from the Headquarters staff on NRC's Office of Enforcement (OE), from NRC's Regional Offices, and from utilities. The three sections of the report are: monthly highlights and statistics for commercial operating units, and errata from previously reported data; a compilation of detailed information on each unit, provided by NRC's Regional Offices, OE Headquarters and the utilities; and an appendix for miscellaneous information such as spent fuel storage capability, reactor-years of experience and non- power reactors in the US

  8. First Algerian research reactor

    International Nuclear Information System (INIS)

    In 1985, both the Algerian Commissariat of New Energies and the Argentine National Atomic Energy Commission plus the firm INVAP S.E., started a series of mutual visits aimed at defining the mechanisms for cooperation in the nuclear field. Within this framework, a commercial contract was undersigned covering the supply of a low-power reactor (RUN), designed for basic and applied research in the fields of reactor physics and nuclear engineering. The reactor may also be used for performing experiences with neutron beams, for the irradiation of several materials and for the training of technicians, scientists and operators

  9. Course on reactor physics

    International Nuclear Information System (INIS)

    In Germany only few students graduate in nuclear technology, therefore the NPP operating companies are forced to develop their own education and training concepts. AREVA NP has started together with the Technical University of Dresden a one-week course ''reactor physics'' that includes the know-how of the nuclear power plant construction company. The Technical University of Dresden has the training reactor AKR-2 that is retrofitted by modern digital instrumentation and control technology that allows the practical training of reactor control.

  10. Fast Breeder Reactor studies

    International Nuclear Information System (INIS)

    This report is a compilation of Fast Breeder Reactor (FBR) resource documents prepared to provide the technical basis for the US contribution to the International Nuclear Fuel Cycle Evaluation. The eight separate parts deal with the alternative fast breeder reactor fuel cycles in terms of energy demand, resource base, technical potential and current status, safety, proliferation resistance, deployment, and nuclear safeguards. An Annex compares the cost of decommissioning light-water and fast breeder reactors. Separate abstracts are included for each of the parts

  11. Nuclear reactor theory

    International Nuclear Information System (INIS)

    This textbook is composed of two parts. Part 1 'Elements of Nuclear Reactor Theory' is composed of only elements but the main resource for the lecture of nuclear reactor theory, and should be studied as common knowledge. Much space is therefore devoted to the history of nuclear energy production and to nuclear physics, and the material focuses on the principles of energy production in nuclear reactors. However, considering the heavy workload of students, these subjects are presented concisely, allowing students to read quickly through this textbook. (J.P.N.)

  12. PWR type reactor

    International Nuclear Information System (INIS)

    From a PWR with a primary circuit, consisting of a reactor pressure vessel, a steam generator and a reactor coolant pump, hot coolant is removed by means of an auxiliary system containing h.p. pumps for feeding water into the primary circuit and being connected with a pipe, originating at the upper part, which has got at least one isolating value. This is done by opening an outlet in a part of the auxiliary system that has got a lower pressure than the reactor vessel. Preferably a water jet pump is used for mixing with the water of the auxiliary system. (orig.)

  13. Fusion Reactor Materials

    International Nuclear Information System (INIS)

    The objective of SCK-CEN's programme on fusion reactor materials is to contribute to the knowledge on the behaviour of fusion reactor materials and components during and after irradiation. Ongoing projects include: the study of the mechanical behaviour of structural materials under neutron irradiation; the investigation of the characteristics of irradiated first wall material such as beryllium; the detection of abrupt electrical degradation of insulating ceramics under high temperature and neutron irradiation; and the study of dismantling and waste disposal strategy for fusion reactors. Progress and achievements in these areas in 2000 are discussed

  14. International tokamak reactor

    International Nuclear Information System (INIS)

    Since 1978, the US, the European Communities, Japan, and the Soviet Union have collaborated on the definition, conceptual design, data base assessment, and analysis of critical technical issues for a tokamak engineering test reactor, called the International Tokamak Reactor (INTOR). During 1985-1986, this activity has been expanded in scope to include evaluation of concept innovations that could significantly improve the tokamak as a commercial reactor. The purposes of this paper are to summarize the present INTOR design concept and to summarize the work on concept innovations

  15. Joyo experimental reactor tour

    International Nuclear Information System (INIS)

    JAEA cooperation in remote monitoring focuses on the Joyo Experimental Reactor at the O'arai Research and Development Center. Joyo performs irradiation of test fuels to support development of the fast reactor cycle in Japan, both in international cooperation and in support of the Monju fast reactor, which is now undergoing reconstruction. The tour included an introduction at the model, a visit to the control room, entry into the containment vessel, and viewing of remote monitoring equipment in the Fresh Fuel Storage and at one of the Spent Fuel Ponds. (author)

  16. Fast Breeder Reactor studies

    Energy Technology Data Exchange (ETDEWEB)

    Till, C.E.; Chang, Y.I.; Kittel, J.H.; Fauske, H.K.; Lineberry, M.J.; Stevenson, M.G.; Amundson, P.I.; Dance, K.D.

    1980-07-01

    This report is a compilation of Fast Breeder Reactor (FBR) resource documents prepared to provide the technical basis for the US contribution to the International Nuclear Fuel Cycle Evaluation. The eight separate parts deal with the alternative fast breeder reactor fuel cycles in terms of energy demand, resource base, technical potential and current status, safety, proliferation resistance, deployment, and nuclear safeguards. An Annex compares the cost of decommissioning light-water and fast breeder reactors. Separate abstracts are included for each of the parts.

  17. nuclear reactor design calculations

    International Nuclear Information System (INIS)

    In this work , the sensitivity of different reactor calculation methods, and the effect of different assumptions and/or approximation are evaluated . A new concept named error map is developed to determine the relative importance of different factors affecting the accuracy of calculations. To achieve this goal a generalized, multigroup, multi dimension code UAR-DEPLETION is developed to calculate the spatial distribution of neutron flux, effective multiplication factor and the spatial composition of a reactor core for a period of time and for specified reactor operating conditions. The code also investigates the fuel management strategies and policies for the entire fuel cycle to meet the constraints of material and operating limitations

  18. Nuclear reactor internal structures

    International Nuclear Information System (INIS)

    The upper internal structures of the reactor are connected to the closing head so as to be readily removed with the latter and a skirt connected to the lower portion of said upper structures so as to surround the latter, extends under the control rods when they are removed from the reactor core. Through such an arrangement the skirt protects the control rods and supports the vessel closing-head and the core upper structures, whenever the head is severed from the vessel and put beside the latter in order to discharge the reactor

  19. Reactor monitoring system

    International Nuclear Information System (INIS)

    The present invention concerns a device for monitoring the inside of an FBR type reactor which can not be monitored by a usual optical camera. An ultrasonic camera having an excellent propagating property in a liquid metal sodium is scanned, and reflected waves of the ultrasonic waves are received as signals. The signals are processed by using a virtual realistic feeling (VR) technique such as a head mounting type image display (HMD) and a three dimensional pointing device. With such procedures, the inside of the FBR type reactor can be observed with such a realistic feeling that the inside of the FBR type reactor were seen directly. (I.S.)

  20. Research reactor support

    International Nuclear Information System (INIS)

    Research reactors (RRs) have been used in a wide range of applications including nuclear power development, basic physics research, education and training, medical isotope production, geology, industry and other fields. However, many research reactors are fuelled with High Enriched Uranium (HEU), are underutilized and aging, and have significant quantities of spent fuel. HEU inventories (fresh and spent) pose security risks Unavailability of a high-density-reprocessable fuel hinders conversion and limits back-end options and represents a survival dilemma for many RRs. Improvement of interim spent fuel storage is required at some RRs. Many RRs are under-utilized and/or inadequately funded and need to find users for their services, or permanently shut down and eventually decommission. Reluctance to decommission affect both cost and safety (loss of experienced staff ) and many shut down but not decommissioned RR with fresh and/or spent fuel at the sites invoke serious concern. The IAEA's research reactor support helps to ensure that research reactors can be operated efficiently with fuels and targets of lower proliferation and security concern and that operators have appropriate technology and options to manage RR fuel cycle issues, especially on long term interim storage of spent research reactor fuel. Availability of a high-density-reprocessable fuel would expand and improve back end options. The International Atomic Energy Agency provides assistance to Member States to convert research reactors from High Enriched Uranium fuel and targets (for medical isotope production) to qualified Low Enriched Uranium fuel and targets while maintaining reactor performance levels. The assistance includes provision of handbooks and training in the performance of core conversion studies, advice for the procurement of LEU fuel, and expert services for LEU fuel acceptance. The IAEA further provides technical and administrative support for countries considering repatriation of its

  1. [Importance of Shaw's Jird Meriones shawii within the trophic components of the Barn Owl Tyto alba in steppic areas of Algeria].

    Science.gov (United States)

    Sekour, Makhlouf; Souttou, Karim; Guerzou, Ahlem; Benbouzid, Noureddine; Guezoul, Omar; Ababsa, Labed; Denys, Christiane; Doumandji, Salaheddine

    2014-06-01

    The study of the diet of the Barn Owl in two steppic regions (M'Sila and Djelfa) located in the Algerian highlands is based on the analysis of the pellets of rejections collected in six stations. The analysis of 706 pellets resulting from the various stations made it possible to count 1380 individuals, represented by seven classes, 12 orders, 32 families, and 76 species of preys. The mammals are consumed with variable abundance rates between 59.1 % and 90.0 % whose predominance is assigned to the rodents (relative abundance: AR > 58 %). The latter constitute the most advantageous preys in biomass (61.4 ≤ B % ≤ 99.2). The most consumed prey is Meriones shawii, with variable rates between 31.9 % and 76.6 %. Generally, Tyto alba presents a diversified diet in the majority of the stations (0.69 ≤ E ≤ 0.76), except the station of Ain El-Hadjel (E = 0.35), with a low diversity and dominance of M. shawii (AR = 76.6 %). PMID:24961561

  2. Agricultural land use and human presence around breeding sites increase stress-hormone levels and decrease body mass in barn owl nestlings.

    Science.gov (United States)

    Almasi, Bettina; Béziers, Paul; Roulin, Alexandre; Jenni, Lukas

    2015-09-01

    Human activities can have a suite of positive and negative effects on animals and thus can affect various life history parameters. Human presence and agricultural practice can be perceived as stressors to which animals react with the secretion of glucocorticoids. The acute short-term secretion of glucocorticoids is considered beneficial and helps an animal to redirect energy and behaviour to cope with a critical situation. However, a long-term increase of glucocorticoids can impair e.g. growth and immune functions. We investigated how nestling barn owls (Tyto alba) are affected by the surrounding landscape and by human activities around their nest sites. We studied these effects on two response levels: (a) the physiological level of the hypothalamus-pituitary-adrenal axis, represented by baseline concentrations of corticosterone and the concentration attained by a standardized stressor; (b) fitness parameters: growth of the nestlings and breeding performance. Nestlings growing up in intensively cultivated areas showed increased baseline corticosterone levels late in the season and had an increased corticosterone release after a stressful event, while their body mass was decreased. Nestlings experiencing frequent anthropogenic disturbance had elevated baseline corticosterone levels, an increased corticosterone stress response and a lower body mass. Finally, breeding performance was better in structurally more diverse landscapes. In conclusion, anthropogenic disturbance affects offspring quality rather than quantity, whereas agricultural practices affect both life history traits. PMID:25903390

  3. Small mammals in the diet of barn owls, Tyto alba (Aves: Strigiformes along the mid-Araguaia river in central Brazil

    Directory of Open Access Journals (Sweden)

    Rita G. Rocha

    2011-12-01

    Full Text Available We collected and analyzed 286 Barn owl, Tyto alba (Scopoli, 1769, pellets from two nests in different environments along the mid-Araguaia River in central Brazil. Our analyses revealed that these owls feed mainly on small mammals, especially rodents. Owls from the riverbanks at Fazenda Santa Fé had a more diverse diet, preying mainly on rodents that typically inhabit riparian grasslands - Holochilus sciureus Wagner, 1842 - and forests - Hylaeamys megacephalus (Fischer, 1814 and Oecomys spp., which probably also occur in forest borders or clearings. On the other hand, owls from an agroecosystem at Fazenda Lago Verde preyed mostly on rodent species common in these agrarian fields, Calomys tocantinsi Bonvicino, Lima & Almeida, 2003. Additionally, we compared small mammal richness estimates based on the analysis of owl pellets with estimates from live-trapping in the same areas. Owl pellets revealed two rodent species undetected by live traps - Euryoryzomys sp. and Rattus rattus (Linnaeus, 1758 - and four rodent species were trapped, but not found in owl pellets - Oecomys roberti Thomas, 1904, Pseudoryzomys simplex (Winge, 1887, Rhipidomys ipukensis Rocha, B.M.A. Costa & L.P. Costa, 2011, and Makalata didelphoides (Desmarest, 1817. Traps yielded higher species richness, but these two methods complement each other for surveying small rodents.

  4. Study of power reactor dynamics by stochastic reactor oscillator method

    International Nuclear Information System (INIS)

    Stochastic reactor oscillator and cross correlation method were used for determining reactor dynamics characteristics. Experimental equipment, fast reactor oscillator (BOR-1) was activated by random pulses from the GBS-16 generator. Tape recorder AMPEX-SF-300 and data acquisition tool registered reactor response to perturbations having different frequencies. Reactor response and activation signals were cross correlated by digital computer for different positions of stochastic oscillator and ionization chamber

  5. Nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    An improved nuclear power reactor fuel element is described which consists of fuel rods, rod guide tubes and an end plate. The system allows direct access to an end of each fuel rod for inspection purposes. (U.K.)

  6. Reactor power control device

    International Nuclear Information System (INIS)

    The present invention concerns a method of controlling reactor power to shift it into a partial power operation upon occurrence of recycling pump tripping or loss of generator load. Operation state of a reactor is classified into a plurality of operation states based on values of the reactor core flow rate and the reactor power. Different insertion patterns for selected control rods are determined on every classified operation states. Then, an insertion pattern corresponding to the operation state upon occurrence of recycling pump tripping or loss of power generator load is carried out to shift into partial power operation. The operation is shifted to a load operation solely in the station while avoiding risks such as TPM scram. Then neutron fluxes are suppressed upon transient to increase margin of fuel integrity. Selected control rod pattern of the optimum reactivity is set to each of operation regions, thereby enabling to conduct flexible countermeasure so as to attain optimum operationability. (N.H.)

  7. Reactor pressure boundary materials

    International Nuclear Information System (INIS)

    With a long-term operation of nuclear power plants, the component materials are degraded under severe reactor conditions such as neutron irradiation, high temperature, high pressure and corrosive environment. It is necessary to establish the reliable and practical technologies for improving and developing the component materials and for evaluating the mechanical properties. Especially, it is very important to investigate the technologies for reactor pressure boundary materials such as reactor vessel and pipings in accordance with their critical roles. Therefore, this study was focused on developing and advancing the microstructural/micro-mechanical evaluation technologies, and on evaluating the neutron irradiation characteristics and radiation effects analysis technology of the reactor pressure boundary materials, and also on establishing a basis of nuclear material property database

  8. Reactor BR2. Introduction

    Energy Technology Data Exchange (ETDEWEB)

    Gubel, P

    2001-04-01

    The BR2 is a materials testing reactor and is still one of SCK-CEN's important nuclear facilities. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. During the last three years, the availability of the installation was maintained at an average level of 97.6 percent. In the year 2000, the reactor was operated for a total of 104 days at a mean power of 56 MW. In 2000, most irradiation experiments were performed in the CALLISTO PWR loop. The report describes irradiations achieved or under preparation in 2000, including the development of advanced facilities and concept studies for new programmes. An overview of the scientific irradiation programmes as well as of the R and D programme of the BR2 reactor in 2000 is given.

  9. Reactor BR2. Introduction

    Energy Technology Data Exchange (ETDEWEB)

    Gubel, P

    2002-04-01

    The BR2 materials testing reactor is one of SCK-CEN's most important nuclear facilities. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. In 2001, the reactor was operated for a total of 123 days at a mean power of 59 MW in order to satisfy the irradiation conditions of the internal and external programmes using mainly the CALLISTO PWR loop. The mean consumption of fresh fuel elements was 5.26 per 1000 MWd. Main achievements in 2001 included the development of a three-dimensional full-scale model of the BR2 reactor for simulation and prediction of irradiation conditions for various experiments; the construction of the FUTURE-MT device designed for the irradiation of fuel plates under representative conditions of geometry, neutron spectrum, heat flux and thermal-hydraulic conditions and the development of in-pile instrumentation and a data acquisition system.

  10. Reactor parameter simulation system

    International Nuclear Information System (INIS)

    A reactor parameter simulation system (RPSS) has been built with the capability of analyzing any reactor signals, decomposing those signals into their deterministic and stochastic components, then reconstructing new, simulated signals that possess the same statistical and correlation structure as the original plant variables. Important uses of the RPSS are for integration with reactor simulation software to provide tools for plant control strategy development, and for safety-study investigations of scenarios that can arise involving signal faults generated from degraded sensors. A third use of the RPSS is for frequency-domain filtering of reactor process variables contaminated with serially correlated noise, which is important for our ongoing development of expert systems for sensor-operability surveillance. 5 refs., 4 figs., 3 tabs

  11. Fusion Reactor Materials

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2002-04-01

    The objective of SCK-CEN's programme on fusion reactor materials is to contribute to the knowledge on the radiation-induced behaviour of fusion reactor materials and components as well as to help the international community in building the scientific and technical basis needed for the construction of the future reactor. Ongoing projects include: the study of the mechanical and chemical (corrosion) behaviour of structural materials under neutron irradiation and water coolant environment; the investigation of the characteristics of irradiated first wall material such as beryllium; investigations on the management of materials resulting from the dismantling of fusion reactors including waste disposal. Progress and achievements in these areas in 2001 are discussed.

  12. New reactor type proposed

    CERN Multimedia

    2003-01-01

    "Russian scientists at the Research Institute of Nuclear Power Engineering in Moscow are hoping to develop a new reactor that will use lead and bismuth as fuel instead of uranium and plutonium" (1/2 page).

  13. Nuclear reactor fuel assembly

    International Nuclear Information System (INIS)

    A fuel assembly construction for liquid metal cooled fast breeder reactors is described in which the sub-assemblies carry a smaller proportion of parasitic material than do conventional sub-assemblies. (U.K.)

  14. Ageing of research reactors

    International Nuclear Information System (INIS)

    Historically, many of the research institutions were centred on a research reactor facility as main technological asset and major source of neutrons for research. Important achievements were made in time in these research institutions for development of nuclear materials technology and nuclear safety for nuclear energy. At present, ageing of nuclear research facilities among these research reactors and ageing of staff are considerable factors of reduction of competence in research centres. The safe way of mitigation of this trend deals with ageing management by so called, for power reactors, Plant Life Management and new investments in staff as investments in research, or in future resources of competence. A programmatic approach of ageing of research reactors in correlation with their actual and future utilisation, will be used as a basis for safety evaluation and future spending. (author)

  15. Experience with Kamini reactor

    International Nuclear Information System (INIS)

    Kamini is a 233U fuelled, 30 kW(th) research reactor. It is one of the best neutron source facility with a core average flux of 1012 n/cm2/s in IGCAR used for neutron radiography of active and nonradioactive objects, activation analysis and radiation physics research. The core consists of nine plate type fuel elements with a total fuel inventory of 590 g of 233U. Two safety control plates made of cadmium are used for start up and shutdown of the reactor. Three beam tubes, two-thimble irradiation site outside reflector and one irradiation site nearer to the core constitute the testing facilities of Kamini. Kamini attained first criticality on 29th October 96 and nominal power of 30 kW in September 1997. This paper covers the design features of the reactor, irradiation facilities and their utilities and operating experience of the reactor. (author)

  16. Dossier: research reactors

    International Nuclear Information System (INIS)

    Research reactors are used at the CEA (the French atomic energy commission) since many years. Their number has been reduced but they remain unique tools that CEA valorize continuously. The results of the programs involving such reactors are of prime importance for the operation of Electricite de France (EdF) park of existing power plants but also for the design of future nuclear power plants and future research reactors. This dossier presents three examples of research reactors in use at the CEA: Osiris and Orphee (CEA-Saclay), devoted to nuclear energy and fundamental research, respectively, and the critical mockups Eole, Minerve and Masurca (CEA-Cadarache) devoted to nuclear data libraries and neutronic calculation. (J.S.)

  17. Reactor vessel sealing plug

    International Nuclear Information System (INIS)

    This invention relates to an apparatus and method for sealing the cold leg nozzles of a nuclear reactor pressure vessel from a remote location during maintenance and inspection of associated steam generators and pumps while the pressure vessel and refueling canal are filled with water. The apparatus includes a sealing plug for mechanically sealing the cold leg nozzle from the inside of a reactor pressure vessel. The sealing plugs include a primary and a secondary O-ring. An installation tool is suspended within the reactor vessel and carries the sealing plug. The tool telescopes to insert the sealing plug within the cold leg nozzle, and to subsequently remove the plug. Hydraulic means are used to activate the sealing plug, and support means serve to suspend the installation tool within the reactor vessel during installation and removal of the sealing plug

  18. Future Reactor Experiments

    CERN Document Server

    He, Miao

    2013-01-01

    The measurement of the neutrino mixing angle $\\theta_{13}$ opens a gateway for the next generation experiments to measure the neutrino mass hierarchy and the leptonic CP-violating phase. Future reactor experiments will focus on mass hierarchy determination and the precision measurement of mixing parameters. Mass hierarchy can be determined from the disappearance of reactor electron antineutrinos based on the interference effect of two separated oscillation modes. Relative and absolute measurement techniques have been explored. A proposed experiment JUNO, with a 20 kton liquid scintillator detector of $3%/$$\\sqrt{E(MeV)}$ energy resolution, $\\sim$ 53 km far from reactors of $\\sim$ 36 GW total thermal power, can reach to a sensitivity of $\\Delta\\chi^{2}>16$ considering the spread of reactor cores and uncertainties of the detector response. Three of mixing parameters are expected to be measured to better than 1% precision. There are multiple detector options for JUNO under investigation. The technical challenges...

  19. Reactor hot spot analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vilim, R.B.

    1985-08-01

    The principle methods for performing reactor hot spot analysis are reviewed and examined for potential use in the Applied Physics Division. The semistatistical horizontal method is recommended for future work and is now available as an option in the SE2-ANL core thermal hydraulic code. The semistatistical horizontal method is applied to a small LMR to illustrate the calculation of cladding midwall and fuel centerline hot spot temperatures. The example includes a listing of uncertainties, estimates for their magnitudes, computation of hot spot subfactor values and calculation of two sigma temperatures. A review of the uncertainties that affect liquid metal fast reactors is also presented. It was found that hot spot subfactor magnitudes are strongly dependent on the reactor design and therefore reactor specific details must be carefully studied. 13 refs., 1 fig., 5 tabs.

  20. Reactor BR2. Introduction

    International Nuclear Information System (INIS)

    The BR2 is a materials testing reactor and is still one of SCK-CEN's important nuclear facilities. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. During the last three years, the availability of the installation was maintained at an average level of 97.6 percent. In the year 2000, the reactor was operated for a total of 104 days at a mean power of 56 MW. In 2000, most irradiation experiments were performed in the CALLISTO PWR loop. The report describes irradiations achieved or under preparation in 2000, including the development of advanced facilities and concept studies for new programmes. An overview of the scientific irradiation programmes as well as of the R and D programme of the BR2 reactor in 2000 is given

  1. Research Reactor Benchmarks

    International Nuclear Information System (INIS)

    A criticality benchmark experiment performed at the Jozef Stefan Institute TRIGA Mark II research reactor is described. This experiment and its evaluation are given as examples of benchmark experiments at research reactors. For this reason the differences and possible problems compared to other benchmark experiments are particularly emphasized. General guidelines for performing criticality benchmarks in research reactors are given. The criticality benchmark experiment was performed in a normal operating reactor core using commercially available fresh 20% enriched fuel elements containing 12 wt% uranium in uranium-zirconium hydride fuel material. Experimental conditions to minimize experimental errors and to enhance computer modeling accuracy are described. Uncertainties in multiplication factor due to fuel composition and geometry data are analyzed by sensitivity analysis. The simplifications in the benchmark model compared to the actual geometry are evaluated. Sample benchmark calculations with the MCNP and KENO Monte Carlo codes are given

  2. Nuclear reactor (1960)

    International Nuclear Information System (INIS)

    The first French plutonium-making reactors G1, G2 and G3 built at Marcoule research center are linked to a power plant. The G1 electrical output does not offset the energy needed for operating this reactor. On the contrary, reactors G2 and G3 will each generate a net power of 25 to 30 MW, which will go into the EDF grid. This power is relatively small, but the information obtained from operation is great and will be helpful for starting up the power reactor EDF1, EDF2 and EDF3. The paper describes how, previous to any starting-up operation, the tests performed, especially those concerned with the power plant and the pressure vessel, have helped to bring the commissioning date closer. (author)

  3. Reactor Neutrino Spectra

    CERN Document Server

    Hayes, A C

    2016-01-01

    We present a review of the antineutrino spectra emitted from reactors. Knowledge of these and their associated uncertainties are crucial for neutrino oscillation studies. The spectra used to-date have been determined by either conversion of measured electron spectra to antineutrino spectra or by summing over all of the thousands of transitions that makeup the spectra using modern databases as input. The uncertainties in the subdominant corrections to beta-decay plague both methods, and we provide estimates of these uncertainties. Improving on current knowledge of the antineutrino spectra from reactors will require new experiments. Such experiments would also address the so-called reactor neutrino anomaly and the possible origin of the shoulder observed in the antineutrino spectra measured in recent high-statistics reactor neutrino experiments.

  4. Pulsed fusion reactors

    International Nuclear Information System (INIS)

    This summer school specialized in examining specific fusion center systems. Papers on scientific feasibility are first presented: confinement of high-beta plasma, liners, plasma focus, compression and heating and the use of high power electron beams for thermonuclear reactors. As for technological feasibility, lectures were on the theta-pinch toroidal reactors, toroidal diffuse pinch, electrical engineering problems in pulsed magnetically confined reactors, neutral gas layer for heat removal, the conceptual design of a series of laser fusion power plants with ''Saturn'', implosion experiments and the problem of the targets, the high brightness lasers for plasma generation, and topping and bottoming cycles. Some problems common to pulsed reactors were examined: energy storage and transfer, thermomechanical and erosion effects in the first wall and blanket, the problems of tritium production, radiation damage and neutron activation in blankets, and the magnetic and inertial confinement

  5. Reactor fueling of BWR type reactors

    International Nuclear Information System (INIS)

    Purpose: To enable the pattern exchange for control rods during burning in Control Cell Core type BWR reactors. Constitution: A plurality of control cells are divided into a plurality of groups such that the control cells is aparted from each other by way of at least two fuel assemblies other than the control cells with respect to the vertical and lateral directions of the reactor core cross section, as well as they are in adjacent with control cells of other groups with respect to the orthogonal direction. This enables to perform the pattern exchange for the control rods during burning in the control cell core with ease, and the control blade and the story effect harmful to the mechanical soundness of fuels can thus be suppressed. (Moriyama, K.)

  6. Reactor Engineering Division annual report

    International Nuclear Information System (INIS)

    Research activities in fiscal 1974 in Reactor Engineering Division of eight laboratories and computing center are described. Works in the division are closely related with the development of a multi-purpose High-temperature Gas Cooled Reactor, the development of a Liquid Metal Fast Breeder Reactor in Power Reactor and Nuclear Fuel Development Corporation, and engineering of thermonuclear fusion reactors. They cover nuclear data and group constants, theoretical method and code development, integral experiment and analysis, shielding, heat transfer and fluid dynamics, reactor and nuclear instrumentation, dynamics analysis and control method development, fusion reactor technology and aspects of the computing center. (auth.)

  7. Special lecture on nuclear reactor

    International Nuclear Information System (INIS)

    This book gives a special lecture on nuclear reactor, which is divided into two parts. The first part has explanation on nuclear design of nuclear reactor and analysis of core with theories of integral transports, diffusion Nodal, transports Nodal and Monte Carlo skill parallel computer and nuclear calculation and speciality of transmutation reactor. The second part deals with speciality of nuclear reactor and control with nonlinear stabilization of nuclear reactor, nonlinear control of nuclear reactor, neural network and control of nuclear reactor, control theory of observer and analysis method of Adomian.

  8. The replacement research reactor

    International Nuclear Information System (INIS)

    The contract for the design, construction and commissioning of the Replacement Research Reactor was signed in July 2000. This was followed by the completion of the detailed design and an application for a construction licence was made in May 2001. This paper will describe the main elements of the design and their relation to the proposed applications of the reactor. The future stages in the project leading to full operation are also described

  9. OECD Halden reactor project

    International Nuclear Information System (INIS)

    This report summarizes the activities of the OECD Halden Reactor Project for the year 1976. The main items reported on are: a) the process supervision and control which have focused on core monitoring and control, and operator-process communication; b) the fuel performance and safety behavior which have provided data and analytical descriptions of the thermal, mechanical and chemical behavior of fuel under various operating conditions; c) the reactor operations and d) the administration and finance

  10. Nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    A nuclear reactor fuel element comprising a column of vibration compacted fuel which is retained in consolidated condition by a thimble shaped plug. The plug is wedged into gripping engagement with the wall of the sheath by a wedge. The wedge material has a lower coefficient of expansion than the sheath material so that at reactor operating temperature the retainer can relax sufficient to accommodate thermal expansion of the column of fuel. (author)

  11. Small reactor return

    International Nuclear Information System (INIS)

    Current state of the development of present-day small reactors in different countries is performed. Various designs of low and middle power reactors, among which are CAREM (25 MW, PWR), KLT-40 (40 MW, PWR), MRX (30 MW, PWR), IRIS (50 MW, PWR), SMART (1000 MW, PWR), Modular SBWR (50 MW, BWR), PBMR (120 MW, HTGR), GT-HMR (285 MW, HTGR), are discussed

  12. Reactor lattice transport calculations

    International Nuclear Information System (INIS)

    The present lecture is a continuation of the lecture on Introduction to the Neutron Transport Phenomena. It comprises three aspects of lattice calculations. First the idea of a reactor lattice is introduced. Then the main definitions used in reactor lattice analysis are given, and finally two basic methods applied for solution of the transport equations are defined. Several remarks on secondary results from lattice transport calculations are added. (author)

  13. Thermal or epithermal reactor

    International Nuclear Information System (INIS)

    In a thermal or epithermal heavy-water reactor of the pressure tube design the reactivity is to be increased by different means: replacement of the moderator by additional rods with heavy metal in the core or in the reflector; separation of the moderator (heavy water) from the coolant (light water) by means of shroud tubes. In light-water reactor types neutron losses are to be influenced by using the heavy elements in different configurations. (orig./PW)

  14. Future reactor experiments

    International Nuclear Information System (INIS)

    The non-zero neutrino mixing angle θ13 has been discovered and precisely measured by the current generation short-baseline reactor neutrino experiments. It opens the gate of measuring the leptonic CP-violating phase and enables the neutrino mass ordering. The JUNO and RENO-50 proposals aim at resolving the neutrino mass ordering using reactors. The experiment design, physics sensitivity, technical challenges as well as the progresses of those two proposed experiments are reviewed in this paper

  15. Water cooled nuclear reactor

    International Nuclear Information System (INIS)

    The description is given of a water cooled nuclear reactor comprising a core, cooling water that rises through the core, vertical guide tubes located inside the core and control rods vertically mobile in the guide tubes. In this reactor the cooling water is divided into a first part introduced at the bottom end of the core and rising through it and a second part introduced at the top end of the guide tubes so as to drop in them

  16. Jet-Stirred Reactors

    OpenAIRE

    Herbinet, Olivier; Guillaume, Dayma

    2013-01-01

    The jet-stirred reactor is a type of ideal continuously stirred-tank reactor which is well suited for gas phase kinetic studies. It is mainly used to study the oxidation and the pyrolysis of hydrocarbon and oxygenated fuels. These studies consist in recording the evolution of the conversion of the reactants and of the mole fractions of reaction products as a function of different parameters such as reaction temperature, residence time, pressure and composition of the inlet gas. Gas chromatogr...

  17. Generation IV reactors: economics

    International Nuclear Information System (INIS)

    The operating nuclear reactors were built over a short period: no more than 10 years and today their average age rounds 18 years. EDF (French electricity company) plans to renew its reactor park over a far longer period : 30 years from 2020 to 2050. According to EDF this objective implies 3 constraints: 1) a service life of 50 to 60 years for a significant part of the present operating reactors, 2) to be ready to built a generation 3+ unit in 2020 which infers the third constraint: 3) to launch the construction of an EPR (European pressurized reactor) prototype as soon as possible in order to have it operating in 2010. In this scheme, generation 4 reactor will benefit the feedback experience of generation 3 and will take over in 2030. Economic analysis is an important tool that has been used by the generation 4 international forum to select the likely future reactor systems. This analysis is based on 4 independent criteria: the basic construction cost, the construction time, the operation and maintenance costs and the fuel cycle cost. This analysis leads to the evaluation of the global cost of electricity generation and of the total investment required for each of the reactor system. The former defines the economic competitiveness in a de-regulated energy market while the latter is linked to the financial risk taken by the investor. It appears, within the limits of the assumptions and models used, that generation 4 reactors will be characterized by a better competitiveness and an equivalent financial risk when compared with the previous generation. (A.C.)

  18. Future reactor experiments

    Science.gov (United States)

    Wen, Liangjian

    2015-07-01

    The non-zero neutrino mixing angle θ13 has been discovered and precisely measured by the current generation short-baseline reactor neutrino experiments. It opens the gate of measuring the leptonic CP-violating phase and enables the neutrino mass ordering. The JUNO and RENO-50 proposals aim at resolving the neutrino mass ordering using reactors. The experiment design, physics sensitivity, technical challenges as well as the progresses of those two proposed experiments are reviewed in this paper.

  19. Department of Reactor Technology

    DEFF Research Database (Denmark)

    Risø National Laboratory, Roskilde

    The general development of the Department of Reactor Technology at Risø during 1981 is presented, and the activities within the major subject fields are described in some detail. Lists of staff, publications, and computer programs are included.......The general development of the Department of Reactor Technology at Risø during 1981 is presented, and the activities within the major subject fields are described in some detail. Lists of staff, publications, and computer programs are included....

  20. AVR reactor physics

    International Nuclear Information System (INIS)

    A process for reactivity control was developed and used for fuelling the AVR reactor core, which is largely based on experimentally determined values. By adding fuel elements with different quantities of heavy metals paired with various experimental requirements, great demands were made of reactivity control. Although only a small range of control was available, this was sufficient to operate the reactor and to shut it down safely in the required power and temperature range. (orig.)

  1. Moon base reactor system

    Science.gov (United States)

    Chavez, H.; Flores, J.; Nguyen, M.; Carsen, K.

    1989-01-01

    The objective of our reactor design is to supply a lunar-based research facility with 20 MW(e). The fundamental layout of this lunar-based system includes the reactor, power conversion devices, and a radiator. The additional aim of this reactor is a longevity of 12 to 15 years. The reactor is a liquid metal fast breeder that has a breeding ratio very close to 1.0. The geometry of the core is cylindrical. The metallic fuel rods are of beryllium oxide enriched with varying degrees of uranium, with a beryllium core reflector. The liquid metal coolant chosen was natural lithium. After the liquid metal coolant leaves the reactor, it goes directly into the power conversion devices. The power conversion devices are Stirling engines. The heated coolant acts as a hot reservoir to the device. It then enters the radiator to be cooled and reenters the Stirling engine acting as a cold reservoir. The engines' operating fluid is helium, a highly conductive gas. These Stirling engines are hermetically sealed. Although natural lithium produces a lower breeding ratio, it does have a larger temperature range than sodium. It is also corrosive to steel. This is why the container material must be carefully chosen. One option is to use an expensive alloy of cerbium and zirconium. The radiator must be made of a highly conductive material whose melting point temperature is not exceeded in the reactor and whose structural strength can withstand meteor showers.

  2. BWR type nuclear reactor

    International Nuclear Information System (INIS)

    Purpose: To simplify the structure of an emergency core cooling system while suppressing the flow out of coolants upon rapture accidents in a coolant recycling device of BWR type reactors. Constitution: Recirculation pumps are located at a position higher than the reactor core in a pressure vessel, and the lower plenum is bisected vertically by a partition plate. Further, a gas-liquid separator is surrounded with a wall and the water level at the outer side of the wall is made higher than the water level in the inside of the wall. In this structure, coolants are introduced from the upper chamber in the lower plenum into the reactor core, and the steams generated in the reactor core are separated in the gas-liquid separator, whereby the separated liquid is introduced as coolants by way of the inner chamber into the lower chamber of the lower plenum and further sent by way of the outer chamber into the reactor core. Consequently, idle rotation of the recycling pumps due to the flow-in of saturated water is prevented and loss of coolants in the reactor core can also be prevented upon raptures in the pipeway and the driving section of the pump connected to the pressure vessel and in the bottom of the pressure vessel. (Horiuchi, T.)

  3. Emergency reactor scram system

    International Nuclear Information System (INIS)

    The present invention provides an emergency reactor scram system capable of shut down a reactor safely upon occurrence of pump trip by improving a passive scram performance for an FBR-type reactor. Namely, a driving motor and an electric generator are connected to a main pump of a primary system. An AC/DC convertor is connected to the electric generator. A shielding plug is disposed to the upper end opening of a reactor container, a control rod drive mechanism is erected on the shielding plug, and an extension pipe is attached to scram magnets of the control rod drive mechanism. The extension pipe is connected to a control rod. The rotation of the shaft of the pump is used as a direct rotator to provide an integrated-type electric generator. The electric generator is electrically connected with the power source of a scram magnet of the emergency scram system. Accordingly, the control rod of the emergency scram system is automatically and rapidly inserted to the reactor core using the power source of the electric generator upon trip of the main pump thereby enabling to scram the reactor safely. (I.S.)

  4. A modular reactor plant

    International Nuclear Information System (INIS)

    This paper describes a new concept in liquid metal reactors that is being developed by General Electric under contract to the Department of Energy. This concept is called the Modular Reactor Plant. While this effort is not expected to have a near-term impact, it is directed toward three principal issues currently affecting nuclear power in the United States. First, plant costs have escalated to the point where the startup of new plants require large electric rate increases. Second, the cost of new plants coming on-line today vary by as much as a factor of three. And, third, nuclear construction times often exceed the utilities prudent planning cycle. This paper describes how General Electric's Modular Reactor Plant addreses these issues through shop fabrication and assembly, rail shipment to the site for rapid installation of nuclear components and inherent reactor protection. In addition, it is expected the modular reactor plant will reduce the current cost of development and demonstration of liquid metal reactors to an affordable level

  5. New fission reactor designs

    International Nuclear Information System (INIS)

    A number of critical challenges to the expanded or continued use of nuclear power have developed. These can be categorized as: regulatory restrictions and complications; negative public attitudes; plant complexity; plant life, operations, and maintenance; uncertain load growth, financing; waste management. Solutions to these challenges through advanced reactor design centre around four key technical responses. Passive safety systems are being introduced which use the laws of physics to provide emergency reactor coding, control and shutdown thus eliminating the possibility of human error. Modular construction promises cuts in costs and construction time by shifting the major part of component manufacture from the site to the factory. Standardization also cuts capital costs and in addition operations and repair costs and expedites reactor licensing. Improvements to the fuel cycle include improved fuel types, designs and fabrication, and the reprocessing of and recycling spent fuel back into energy production, thus extending uranium resources and offering a partial solution to the problem of waste disposal. Examples of evolutionary and advanced water-cooled reactors, modular high temperature gas-cooled reactors, and advanced liquid metal cooled fast breeder reactors which are being developed round the world are presented. (author)

  6. OECD Halden reactor project

    International Nuclear Information System (INIS)

    This is the nineteenth annual Report on the OECD Halden Reactor Project, describing activities at the Project during 1978, the last year of the 1976-1978 Halden Agreement. Work continued in two main fields: test fuel irradiation and fuel research, and computer-based process supervision and control. Project research on water reactor fuel focusses on various aspects of fuel behavior under normal, and off-normal transient conditions. In 1978, participating organisations continued to submit test fuel for irradiation in the Halden boiling heavy-water reactor, in instrumented test assemblies designed and manufactured by the Project. Work included analysis of the impact of fuel design and reactor operating conditions on fuel cladding behavior. Fuel performance modelling included characterization of thermal and mechanical behavior at high burn-up, of fuel failure modes, and improvement of data qualification procedures to reduce and quantify error bands on in-reactor measurements. Instrument development yielded new or improved designs for measuring rod temperature, internal pressure, axial neutron flux shape determination, and for detecting cladding defects. Work on computer-based methods of reactor supervision and control included continued development of a system for predictive core surveillance, and of special mathematical methods for core power distribution control

  7. Reactor power measuring device

    International Nuclear Information System (INIS)

    The device of the present invention efficiently calibrates a fixed type gamma ray thermometer of a reactor power measuring device of a BWR type reactor. Namely, the device of the present invention calculates peripheral fuel rod power distribution by calibrating the reactor power distribution by heat generation amount, the reactor power distribution being obtained by a calculation based on a reactor model for converting the signals of a plurality of the gamma ray thermometers in the reactor core based on a conversion formula. In this case, the conversion formula is a relational formula between the power of a thermocouple of the gamma ray thermometer, gamma ray heat generation amount, thermocouple zero power sensitivity relative to a temperature coefficient. A conversion efficient calculation means makes a calibration heater to generate heat at a predetermined power, and the thermocouple zero power sensitivity and the temperature coefficient are obtained based on the output of the gamma ray thermometer in this case. The calibration means updates to conversion type thermocouple zero power sensitivity and temperature coefficient. A calibration execution means executes the operations described above successively, and when the thermocouple zero power sensitivity and the temperature coefficient are out of an allowable range, the means informs it and eliminates the corresponding gamma ray thermometer from the measuring meters. (I.S.)

  8. Reactor safety engineering

    International Nuclear Information System (INIS)

    The concept of the work is such that the basic safety philosophy for nuclear power plants as well as the safety features of both types of light water reactors, pressurized and boiling water reactors, and of the fast breeder reactor are dealt with. With the pressurized and boiling water reactors also variations, due to different supplies are mentioned. The state of development considered is characterized by the results of the American reactor safety study having very much influenced the way of presentation and the validity of the information contained. In the introduction the attentive reader is made familiar with the basic traits of safety engineering, the traditional deterministic way of proceeding being supplemented by a detailed illustration of probabilistic means used in the safety analysis. Added to this are comparative descriptions of the individual safety features, their design and mode of operation. There are, e.g., detailed discussion of the emergency core cooling systems, the power supply systems, the reactor protection system, and the containment. Special chapters are attributed to transients with and without the fast shutdown system working and to loss of coolant. The so-called external events are treated somewhat shortly whereas much space is given to core melting problems. The treatment of important events from the safety point of view, including the section on Harrisburg added for reasons of immediate interest, is limited to phenomenological description. (orig.)

  9. Regulations for RA reactor operation

    International Nuclear Information System (INIS)

    Regulations for RA reactor operation are written in accordance with the legal regulations defined by the Law about radiation protection and related legal acts, as well as technical standards according to the IAEA recommendations. The contents of this book include: fundamental data about the reactor; legal regulations for reactor operation; organizational scheme for reactor operation; general and detailed instructions for operation, behaviour in the reactor building, performing experiments; operating rules for operation under steady state and accidental conditions

  10. The reactor Cabri

    International Nuclear Information System (INIS)

    It has become necessary to construct in France a reactor which would permit the investigation of the conditions of functioning of future installations, the choice, the testing and the development of safety devices to be adopted. A water reactor of a type corresponding to the latest CEA constructions in the field of laboratory or university reactors was decided upon: it appeared important to be able to evaluate the risks entailed and to study the possibilities of increasing the power, always demanded by the users; on the other hand, it is particularly interesting to clarify the phenomena of power oscillation and the risks of burn out. The work programme for CABRI will be associated with the work carried out on the American Sperts of the same type, during its construction, very useful contacts were made with the American specialists who designed the se reactors. A brief description of the reactor is given in the communication as well as the work programme for the first years with respect to the objectives up to now envisaged. Rough description of the reactor. CABRI is an open core swimming-pool reactor without any lateral protection, housed in a reinforced building with controlled leakage, in the Centre d'Etudes Nucleaires de Cadarache. It lies alone in the middle of an area whose radius is 300 meters long. Control and measurements equipment stand out on the edge of that zone. It consumes MTR fuel elements. The control-safety rods are propelled by compressed air. The maximum flow rate of cooling circuit is 1500 m3/h. Transient measurements are recorded in a RW330 unit. Aims and work programme. CABRI is meant for: - studies on the safety of water reactors - for the definition of the safety margins under working conditions: research of maximum power at which a swimming-pool reactor may operate with respect to a cooling accident, of local boiling effect on the nuclear behaviour of the reactor, performances of the control and safety instruments under exceptional

  11. REACTOR GROUT THERMAL PROPERTIES

    Energy Technology Data Exchange (ETDEWEB)

    Steimke, J.; Qureshi, Z.; Restivo, M.; Guerrero, H.

    2011-01-28

    Savannah River Site has five dormant nuclear production reactors. Long term disposition will require filling some reactor buildings with grout up to ground level. Portland cement based grout will be used to fill the buildings with the exception of some reactor tanks. Some reactor tanks contain significant quantities of aluminum which could react with Portland cement based grout to form hydrogen. Hydrogen production is a safety concern and gas generation could also compromise the structural integrity of the grout pour. Therefore, it was necessary to develop a non-Portland cement grout to fill reactors that contain significant quantities of aluminum. Grouts generate heat when they set, so the potential exists for large temperature increases in a large pour, which could compromise the integrity of the pour. The primary purpose of the testing reported here was to measure heat of hydration, specific heat, thermal conductivity and density of various reactor grouts under consideration so that these properties could be used to model transient heat transfer for different pouring strategies. A secondary purpose was to make qualitative judgments of grout pourability and hardened strength. Some reactor grout formulations were unacceptable because they generated too much heat, or started setting too fast, or required too long to harden or were too weak. The formulation called 102H had the best combination of characteristics. It is a Calcium Alumino-Sulfate grout that contains Ciment Fondu (calcium aluminate cement), Plaster of Paris (calcium sulfate hemihydrate), sand, Class F fly ash, boric acid and small quantities of additives. This composition afforded about ten hours of working time. Heat release began at 12 hours and was complete by 24 hours. The adiabatic temperature rise was 54 C which was within specification. The final product was hard and displayed no visible segregation. The density and maximum particle size were within specification.

  12. Materials for nuclear reactors

    International Nuclear Information System (INIS)

    The improved performance of present generation nuclear reactors and the realization of advanced reactor concepts, both, require development of better materials. Physical metallurgy/materials science principles which have been exploited in meeting the exacting requirements of nuclear reactor materials (fuels and structural materials), are outlined citing a few specific examples. While the incentive for improvement of traditional fuels (e.g., UO2 fuel) is primarily for increasing the average core burn up, the development of advanced fuels (e.g., MOX, mixed carbide, nitride, silicide and dispersion fuels) are directed towards better utilization of fissile and fertile inventories through adaptation of innovative fuel cycles. As the burn up of UO2 fuel reaches higher levels, a more detailed and quantitative understanding of the phenomena such as fission gas release, fuel restructuring induced by radiation and thermal gradients and pellet-clad interaction is being achieved. Development of zirconium based alloys for both cladding and pressure tube applications is discussed with reference to their physical metallurgy, fabrication techniques and in-reactor degradation mechanisms. The issue of radiation embrittlement of reactor pressure vessels (RPVs) is covered drawing a comparison between the western and eastern specifications of RPV steels. The search for new materials which can stand higher rates of atomic displacement due to radiation has led to the development of swelling resistant austenitic and ferritic stainless steels for fast reactor applications as exemplified by the development of the D-9 steel for Indian fast breeder reactor. The presentation will conclude by listing various materials related phenomena, which have a strong bearing on the successful development of future nuclear energy systems. (author)

  13. Reactor physics and economic aspects of the CANDU reactor system

    International Nuclear Information System (INIS)

    A history of the development of the CANDU system is given along with a fairly detailed description of the 600 MW(e) CANDU reactor. Reactor physics calculation methods are described, as well as comparisons between calculated reactor physics parameters and those measured in research and power reactors. An examination of the economics of CANDU in the Ontario Hydro system and a comparison between fossil fuelled and light water reactors is presented. Some physics, economics and resources aspects are given for both low enriched uranium and thorium-fuelled CANDU reactors. Finally the RβD program in Advanced Fuel Cycles is briefly described

  14. Reactor Safety Planning for Prometheus Project, for Naval Reactors Information

    Energy Technology Data Exchange (ETDEWEB)

    P. Delmolino

    2005-05-06

    The purpose of this letter is to submit to Naval Reactors the initial plan for the Prometheus project Reactor Safety work. The Prometheus project is currently developing plans for cold physics experiments and reactor prototype tests. These tests and facilities may require safety analysis and siting support. In addition to the ground facilities, the flight reactor units will require unique analyses to evaluate the risk to the public from normal operations and credible accident conditions. This letter outlines major safety documents that will be submitted with estimated deliverable dates. Included in this planning is the reactor servicing documentation and shipping analysis that will be submitted to Naval Reactors.

  15. Fast breeder reactor research

    International Nuclear Information System (INIS)

    Full text: The meeting was attended by 15 participants from seven countries and two international organizations. The Eighth Annual Meeting of the International Working Group on Fast Reactors (IWGFR) was attended by representatives from France, Fed. Rep. Germany, Italy, Japan, United Kingdom, Union of Soviet Socialist Republics and the United States of America - countries that have made significant progress in developing the technology and physics of sodium cooled fast reactors and have extensive national programmes in this field - as well as by representatives of the Commission of the European Communities and the IAEA. The design of fast-reactor power plants is a more difficult task than developing facilities with thermal reactors. Different reactor kinetics and dynamics, a hard neutron spectrum, larger integral doses of fuel and structural material irradiation, higher core temperatures, the use of an essentially novel coolant, and, as a result of all these factors, the additional reliability and safety requirements that are imposed on the planning and operation of sodium cooled fast reactors - all these factors pose problems that can be solved comprehensively only by countries with a high level of scientific and technical development. The exchange of experience between these countries and their combined efforts in solving the fundamental problems that arise in planning, constructing and operating fast reactors are promoting technical progress and reducing the relative expenditure required for various studies on developing and introducing commercial fast reactors. For this reason, the meeting concentrated on reviewing and discussing national fast reactor programmes. The situation with regard to planning, constructing and operating fast experimental and demonstration reactors in the countries concerned, the experience accumulated in operating them, the difficulties arising during operation and ways of over-coming them, the search for optimal designs for the power

  16. BR2 Reactor: Introduction

    International Nuclear Information System (INIS)

    The irradiations in the BR2 reactor are in collaboration with or at the request of third parties such as the European Commission, the IAEA, research centres and utilities, reactor vendors or fuel manufacturers. The reactor also contributes significantly to the production of radioisotopes for medical and industrial applications, to neutron silicon doping for the semiconductor industry and to scientific irradiations for universities. Along the ongoing programmes on fuel and materials development, several new irradiation devices are in use or in design. Amongst others a loop providing enhanced cooling for novel materials testing reactor fuel, a device for high temperature gas cooled fuel as well as a rig for the irradiation of metallurgical samples in a Pb-Bi environment. A full scale 3-D heterogeneous model of BR2 is available. The model describes the real hyperbolic arrangement of the reactor and includes the detailed 3-D space dependent distribution of the isotopic fuel depletion in the fuel elements. The model is validated on the reactivity measurements of several tens of BR2 operation cycles. The accurate calculations of the axial and radial distributions of the poisoning of the beryllium matrix by 3He, 6Li and 3T are verified on the measured reactivity losses used to predict the reactivity behavior for the coming decades. The model calculates the main functionals in reactor physics like: conventional thermal and equivalent fission neutron fluxes, number of displacements per atom, fission rate, thermal power characteristics as heat flux and linear power density, neutron/gamma heating, determination of the fission energy deposited in fuel plates/rods, neutron multiplication factor and fuel burn-up. For each reactor irradiation project, a detailed geometry model of the experimental device and of its neighborhood is developed. Neutron fluxes are predicted within approximately 10 percent in comparison with the dosimetry measurements. Fission rate, heat flux and

  17. Reactor coolant cleanup facility

    International Nuclear Information System (INIS)

    A depressurization device is disposed in pipelines upstream of recycling pumps of a reactor coolant cleanup facility to reduce a pressure between the pressurization device and the recycling pump at the downstream, thereby enabling high pressure coolant injection from other systems by way of the recycling pumps. Upon emergency, the recycling pumps of the coolant cleanup facility can be used in common to an emergency reactor core cooling facility and a reactor shutdown facility. Since existent pumps of the emergency reactor core cooling facility and the reactor shutdown facility which are usually in a stand-by state can be removed, operation confirmation test and maintenance for equipments in both of facilities can be saved, so that maintenance and reliability of the plant are improved and burdens on operators can also be mitigated. Moreover, low pressure design can be adopted for a non-regenerative heat exchanger and recycling coolant pumps, which enables to improve the reliability and economical property due to reduction of possibility of leakage. (N.H.)

  18. HTGR type reactor

    International Nuclear Information System (INIS)

    A reactor core is disposed at the center of a reactor container, a reflector is disposed on the outer side thereof, a steam generator is disposed further outer side thereof coaxially, and they are constituted as an integrated one container. A gas circulator and control rod drives are protruded at the outer side of the lower portion of the integrated container. Heat insulators are disposed on the inner side of the container wall in the upper portion of the reactor container. Helium gas risen in the reactor core and heated to a high temperature descends in a circular steam generator and undergoes heat exchange with water, and is then pressurized in the gas circulator after the lowering of the temperature, and returned to the inlet of the reactor core from the lower central portion of the container. With such procedures, the helium gas as primary coolants circulates only in the container to improve confinement. The device can be reduced in the size and the cost. (I.N.)

  19. Reactor container spray device

    International Nuclear Information System (INIS)

    Purpose: To enable decrease in the heat and the concentration of radioactive iodine released from the reactor vessel into the reactor container in the spray device of BWR type reactors. Constitution: A plurality of water receiving trays are disposed below the spray nozzle in the dry well and communicated to a pressure suppression chamber by way of drain pipeways passing through a diaphragm floor. When the recycling system is ruptured and coolants in the reactor vessel and radioactive iodine in the reactor core are released into the dry well, spray water is discharged from the spray nozzle to eliminate the heat and the radioactive iodine in the dry well. In this case, the receiving trays collect the portions of spray water whose absorption power for the heat and radioactive iodine is nearly saturated and falls them into the pool water of the pressure suppression chamber. Consequently, other portions of the spray water that still possess absorption power can be jetted with no hindrance, to increase the efficiency for the removal of the heat and iodine of the spray droplets. (Horiuchi, T.)

  20. PROTEUS research reactor

    International Nuclear Information System (INIS)

    The PROTEUS zero power reactor at the Paul Scherrer Institute (PSI) in Switzerland achieved first criticality in 1968 and since then has been operated as an experimental tool for reactor physics research on test lattices representative of a wide range of reactor concepts. Reactor design codes and their associated data libraries are validated on the basis of the experimental results obtained. PROTEUS is normally configured as a driven system, in which a subcritical test zone is made critical by the surrounding driver zones. The advantages of driven systems can be summarized as follows: - Smaller amount of test fuel is required; - Large range of test zone conditions (including k∞ < 1 states) can be investigated by changes in the driver loading alone, thus avoiding undesirable perturbations to the test zone which would influence the measurement conditions and thus affect the interpretability of the results; - Necessary reactor control and instrumentation equipment (usually perturbing from the experimental viewpoint) can be located in the outer driver regions, thereby avoiding disturbance of the test lattice

  1. Generalities about nuclear reactors

    International Nuclear Information System (INIS)

    From Zoe, the first nuclear reactor, till the current EPR, the French nuclear industry has always advanced by profiting from the feedback from dozens of years of experience and operations, in particular by drawing lessons from the most significant events in its history, such as the Fukushima accident. The new generations of reactors must improve safety and economic performance so that the industry maintain its legitimacy and its share in the production of electricity. This article draws the history of nuclear power in France, gives a brief description of the pressurized water reactor design, lists the technical features of the different versions of PWR that operate in France and compares them with other types of reactors. The feedback experience concerning safety, learnt from the major nuclear accidents Three Miles Island (1979), Chernobyl (1986) and Fukushima (2011) is also detailed. Today there are 26 third generation reactors being built in the world: 4 EPR (1 in Finland, 1 in France and 2 in China); 2 VVER-1200 in Russia, 8 AP-1000 (4 in China and 4 in the Usa), 8 APR-1400 (4 in Korea and 4 in UAE), and 4 ABWR (2 in Japan and 2 in Taiwan)

  2. China experimental fast reactor

    International Nuclear Information System (INIS)

    The Chinese experimental fast reactor (CEFR) is a pool-type sodium-cooled fast reactor whose short term purposes are: -) the validation of computer codes, -) the check of the relevance of standards, and -) the gathering of experimental data on fast reactors. On the long term the expectations will focus on: -) gaining experience in fast reactor operations, -) the testing of nuclear fuels and materials, and -) the study of sodium compounds. The main technical features of CEFR are: -) thermal power output: 65 MW (electrical power output: 20 MW), -) size of the core: height: 45 cm, diameter: 60 cm, -) maximal linear output: 430 W/cm, -) neutron flux: 3.7*1015 n/cm2/s, -) input/output sodium temperature: 360 / 530 Celsius degrees, -) 2 loops for the primary system and 2 loops for the secondary system. The temperature coefficient and the power coefficient are settled to stay negative for any change in the values of the core parameters. The installation of the reactor vessel will be completed by mid 2007. The first criticality of CEFR is expected during the first semester of 2010. (A.C.)

  3. EBT reactor analysis

    International Nuclear Information System (INIS)

    This report summarizes the results of a recent ELMO Bumpy Torus (EBT) reactor study that includes ring and core plasma properties with consistent treatment of coupled ring-core stability criteria and power balance requirements. The principal finding is that constraints imposed by these coupling and other physics and technology considerations permit a broad operating window for reactor design optimization. Within this operating window, physics and engineering systems analysis and cost sensitivity studies indicate that reactors with approx. 6 to 10%, P approx. 1200 to 1700 MW(e), wall loading approx. 1.0 to 2.5 MW/m2, and recirculating power fraction (including ring-sustaining power and all other reactors auxiliaries) approx. 10 to 15% are possible. A number of concept improvements are also proposed that are found to offer the potential for further improvement of the reactor size and parameters. These include, but are not limited to, the use of: (1) supplementary coils or noncircular mirror coils to improve magnetic geometry and reduce size, (2) energetic ion rings to improve ring power requirements, (3) positive potential to enhance confinement and reduce size, and (4) profile control to improve stability and overall fusion power density

  4. Modern research reactors in the world and RA research reactor

    International Nuclear Information System (INIS)

    This paper covers the following topics: fundamentals of research reactors, thermal neutron flux density, classification of research reactors in the world, properties of research reactors of higher power in the world according to IAEA data for 1995, their application, and trend of development, experimental feasibility and status of RA reactor. Trend of research reactors development in the world (after 1980) is directed towards increasing the neutron production quality factor, i.e. ratio between thermal neutron flux density and reactor power, which is achieved by designing compact reactor cores. With the aim of renewal of RA reactor (without analysis of reactor components and staff aging, possibility of restart and commercialization), according to the analysis in this paper, it can be concluded: there is very few reactors under construction in the world, all the important countries in Europe have research reactors; RA reactor is not very interesting for development of reactor physics; nowadays RA reactor is in the group of reactors which are 30-40 years old; its inventories of fuel and heavy water are enough for about 20 years of operation; it has achieved high quality factor of neutron production with low and highly enriched fuel; core transfer from low highly enriched to low enriched fuel should be carefully studies from operation, experimental and economical point of view; it is necessary to use the advantages of RA reactor (minimum investment): volume of the core and reflector which enables availability of neutron flux for the users (numerous experimental loops), fuel in shape of slugs enabling efficient fuel management and flexible neutron flux distribution in the core in the reflector, reactor operation should be directed towards commercial applications. Bibliography of more than 140 relevant papers used is included in this paper

  5. Sodium-cooled nuclear reactors

    International Nuclear Information System (INIS)

    This book first explains the choice of sodium-cooled reactors by outlining the reasons of the choice of fast neutron reactors (fast neutrons instead of thermal neutrons, recycling opportunity for plutonium, full use of natural uranium, nuclear waste optimization, flexibility of fast neutron reactors in nuclear material management, fast neutron reactors as complements of water-cooled reactors), and by outlining the reasons for the choice of sodium as heat-transfer material. Physical, chemical, and neutron properties of sodium are presented. The second part of the book first presents the main design principles for sodium-cooled fast neutron reactors and their core. The third part proposes an historical overview and an assessment of previously operated sodium-cooled fast neutron reactors (French reactors from Rapsodie to Superphenix, other reactors in the world), and an assessment of the main incidents which occurred in these reactors. It also reports the experience and lessons learned from the dismantling of various sodium-cooled fast breeder reactors in the world. The next chapter addresses safety issues (technical and safety aspects related to the use of sodium) and environmental issues (dosimetry, gaseous and liquid releases, solid wastes, and cooling water). Then, various technological aspects of these reactors are addressed: the energy conversion system, main components, sodium chemistry, sodium-related technology, advances in in-service inspection, materials used in reactors and their behaviour, and fuel system. The next chapter addresses the fuel cycle in these reactors: its integrated specific character, report of the French experience in fast neutron reactor fuel processing, description of the transmutation of minor actinides in these reactors. The last chapter proposes an overview of reactors currently projected or under construction in the world, presents the Astrid project, and gives an assessment of the economy of these reactors. A glossary and an index

  6. Scaleable, High Efficiency Microchannel Sabatier Reactor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A Microchannel Sabatier Reactor System (MSRS) consisting of cross connected arrays of isothermal or graded temperature reactors is proposed. The reactor array...

  7. 密集烤房不同装烟方式比较研究%Comparison of Tobacco Leaf Loading Methods in Bulk Curing Barn

    Institute of Scientific and Technical Information of China (English)

    孙曙光; 周童; 顾会战; 彭毅; 汪健; 王鹏; 陈利平

    2012-01-01

    [目的]探索密集烤房的最佳装烟方式.[方法]以密集烤房挂杆方式为对照,比较研究了托架式烟夹、框架散叶、散叶插签装烟方式的配套设备成本、装烟量、用工量、烤后烟叶经济性状、能耗成本等状况.[结果]托架式烟夹、框架散叶、散叶插签装烟方式节能省工效果明显,3种装烟方式装烟量最大可提高71.43%,初烤烟经济性状均有所提高,符合现代烟草农业集约化和可持续发展要求.[结论]研究可为密集烤房不同装烟方式的优化提供参考依据.%[Objective] To explore the best tobacco leaf loading method. [Method] With hang poles as control group, bracket type smoke clamp, framework loose leaf and loose leaf cutting sign loading tobacco patterns were tested in bulk curing barn about corollary equipment cost, pack smoke volume, the employment quantity, roast tobacco leaf after economic characters, energy consumption cost. [Result] The results showed that bracket type smoke clamp, framework loose leaf and loose leaf cutting sign were much better than hang poles in energy and worker saving. Because largest amount of the three tobacco leaf loading method can be increased by 71. 43 % and initial flue-cured tobacco economic characters are improved so they accord with the modern tobacco agriculture. [Conclusion] The study provides reference basis for optimization of different tobacco loading method.

  8. Analysis of Odor-Causing VOCs and Semi-VOCs Associated with Particulate Matter in Swine Barns Using SPME-GC-MS-Olfactometry

    Science.gov (United States)

    Cai, Lingshuang; Koziel, Jacek A.; Lo, Yin-Cheung; Hoff, Steven J.

    2009-05-01

    Swine operations can affect air quality by emissions of odor, volatile organic compounds (VOCs) and other gases, and particulate matter (PM). Particulate matter has been proposed to be an important pathway for carrying odor. However, little is known about the odor-VOCs-PM interactions. In this research, continuous PM sampling was conducted simultaneously with three collocated TEOM analyzers inside a 1000-head swine finish barn located in central Iowa. Each TEOM (tapered element oscillating microbalance) was fitted with total suspended particulate (TSP), PM-10, PM-2.5 and PM-1 preseparators. Used filters were stored in 40 mL vials and transported to the laboratory. VOCs adsorbed/absorbed to dust were allowed to equilibrate with vial headspace. Solid-phase microextraction (SPME) Carboxen/polydimethylsiloxane(PDMS) 85 μm fibers were used to extract VOCs. Simultaneous chemical and olfactometry analyses of VOCs and odor associated with swine PM were completed using a gas chromatography-mass-olfactometry (GC-MS-O) system. Fifty VOCs categorized into nine chemical function groups were identified and confirmed with standards. Five of them are classified as hazardous air pollutants. VOCs were characterized with a wide range of molecular weight, boiling points, vapor pressures, water solubilities, odor detection thresholds, and atmospheric reactivities. All characteristic swine VOCs and odorants were present in PM and their abundance was proportional to PM size. However, the majority of VOCs and characteristic swine odorants were preferentially bound to smaller-size PM. The findings indicate that a significant fraction of swine odor can be carried by PM. Research of the effects of PM control on swine odor mitigation is warranted.

  9. Paenochrobactrum gallinarii gen. nov., sp. nov., isolated from air of a duck barn, and reclassification of Pseudochrobactrum glaciei as Paenochrobactrum glaciei comb. nov.

    Science.gov (United States)

    Kämpfer, Peter; Martin, Elena; Lodders, Nicole; Jäckel, Udo; Huber, Birgit E; Schumann, Peter; Langer, Stefan; Busse, Hans-Jürgen; Scholz, Holger

    2010-07-01

    A Gram-negative, rod-shaped, oxidase-positive, non-spore-forming, non-motile bacterium (Sa25(T)) was isolated from air of a duck barn. 16S rRNA gene and recA sequence analyses clearly placed the isolate in the vicinity of the Brucella-Ochrobactrum-Pseudochrobactrum group, with the closest relative being Pseudochrobactrum glaciei KMM 3858(T). This allocation was confirmed by analyses of the quinone system (ubiquinone Q-10), fatty acid data (major fatty acids C(18 : 1)omega7c and C(19 : 0) cyclo omega8c) and polar lipid profile (major components diphosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and unknown aminolipid AL1; moderate amounts of three unknown polar lipids, L1-L3, an unknown aminolipid and an unknown aminophospholipid APL2). The polyamine pattern of Sa25(T) exhibited the major compound putrescine and moderate amounts of spermidine; a similar polyamine pattern with the major compound putrescine was also detected in Pseudochrobactrum glaciei KMM 3858(T). DNA-DNA hybridization of strain Sa25(T) with Pseudochrobactrum glaciei KMM 3858(T) and the type strains of the other Pseudochrobactrum species showed values ranging from 50.3 to 24.8 %, and physiological and biochemical data clearly differentiated this isolate from the described Pseudochrobactrum species. Since Sa25(T) and Pseudochrobactrum glaciei KMM 3858(T) form a distinct lineage in the 16S rRNA gene sequence-based phylogenetic tree, and this separate position is supported by unique characteristics of their polyamine patterns and polar lipid profiles, we propose the novel genus Paenochrobactrum gen. nov., with the type species Paenochrobactrum gallinarii sp. nov. (type strain Sa25(T) =CCUG 57736(T) =CCM 7656(T)) and the reclassification of Pseudochrobactrum glaciei as Paenochrobactrum glaciei comb. nov. (type strain Pi26(T) =KMM 3858(T) =NRIC 0733(T) =JCM 15115(T)). PMID:19684318

  10. Divorce in the barn owl: securing a compatible or better mate entails the cost of re-pairing with a less ornamented female mate.

    Science.gov (United States)

    Dreiss, A N; Roulin, A

    2014-06-01

    Two nonmutually exclusive hypotheses can explain why divorce is an adaptive strategy to improve reproductive success. Under the 'better option hypothesis', only one of the two partners initiates divorce to secure a higher-quality partner and increases reproductive success after divorce. Under the 'incompatibility hypothesis', partners are incompatible and hence they may both increase reproductive success after divorce. In a long-term study of the barn owl (Tyto alba), we address the question of whether one or the two partners derive fitness benefits by divorcing. Our results support the hypothesis that divorce is adaptive: after a poor reproductive season, at least one of the two divorcees increase breeding success up to the level of faithful pairs. By breeding more often together, faithful pairs improve coordination and thereby gain in their efficiency to produce successful fledglings. Males would divorce to obtain a compatible mate rather than a mate of higher quality: a heritable melanin-based signal of female quality did not predict divorce (indicating that female absolute quality may not be the cause of divorce), but the new mate of divorced males was less melanic than their previous mate. This suggests that, at least for males, a cost of divorce may be to secure a lower-quality but compatible mate. The better option hypothesis could not be formally rejected, as only one of the two divorcing partners commonly succeeded in obtaining a higher reproductive success after divorce. In conclusion, incompatible partners divorce to restore reproductive success, and by breeding more often together, faithful partners improve coordination. PMID:24773174

  11. Methanation assembly using multiple reactors

    Science.gov (United States)

    Jahnke, Fred C.; Parab, Sanjay C.

    2007-07-24

    A methanation assembly for use with a water supply and a gas supply containing gas to be methanated in which a reactor assembly has a plurality of methanation reactors each for methanating gas input to the assembly and a gas delivery and cooling assembly adapted to deliver gas from the gas supply to each of said methanation reactors and to combine water from the water supply with the output of each methanation reactor being conveyed to a next methanation reactor and carry the mixture to such next methanation reactor.

  12. Mimic of OSU research reactor

    International Nuclear Information System (INIS)

    The Ohio State University research reactor (OSURR) is undergoing improvements in its research and educational capabilities. A computer-based digital data acquisition system, including a reactor system mimic, will be installed as part of these improvements. The system will monitor the reactor system parameters available to the reactor operator either in digital parameters available to the reactor operator either in digital or analog form. The system includes two computers. All the signals are sent to computer 1, which processes the data and sends the data through a serial port to computer 2 with a video graphics array VGA monitor, which is utilized to display the mimic system of the reactor

  13. MINT research reactor safety program

    Energy Technology Data Exchange (ETDEWEB)

    Mohamad Idris bin Taib [Division of Special Project, Malaysian Institute for Nuclear Technology Research (MINT), Bangi (Malaysia)

    2000-11-01

    Malaysian Institute for Nuclear Technology Research (MINT) Research Reactor Safety Program has been done along with Reactor Power Upgrading Project, Reactor Safety Upgrading Project and Development of Expert System for On-Line Nuclear Process Control Project. From 1993 up to date, Neutronic and Thermal-hydraulics analysis, Probabilistic Safety Assessment as well as installation of New 2 MW Secondary Cooling System were done. Installations of New Reactor Building Ventilation System, Reactor Monitoring System, Updating of Safety Analysis Report and Upgrading Primary Cooling System are in progress. For future activities, Reactor Modeling will be included to add present activities. (author)

  14. RB research reactor Safety Report

    International Nuclear Information System (INIS)

    This RB reactor safety report is a revised and improved version of the Safety report written in 1962. It contains descriptions of: reactor building, reactor hall, control room, laboratories, reactor components, reactor control system, heavy water loop, neutron source, safety system, dosimetry system, alarm system, neutron converter, experimental channels. Safety aspects of the reactor operation include analyses of accident causes, errors during operation, measures for preventing uncontrolled activity changes, analysis of the maximum possible accident in case of different core configurations with natural uranium, slightly and highly enriched fuel; influence of possible seismic events

  15. 巴基斯坦旁遮普中部仓鸮食性的季节性变化%Seasonal variation in the diet of the barn owl Tyto alba stertens in central Punjab, Pakistan

    Institute of Scientific and Technical Information of China (English)

    Muhammad MAHMOOD-UL-HASSAN; Mirza Azhar BEG; Habib ALI

    2007-01-01

    在巴基斯坦对仓鸮食性的季节变化进行了研究.通过分析连续3年在6个地区搜集的2 360个仓鸮回吐食物团,发现其食物主要是小型哺乳动物(95.6%).其中,家鼩(Suncus murinus)有最高的比例,达65.6%(冬季最多78%,夏季最少27%).就生物量而言,小型哺乳动物占仓鸮食物总生物量的99%[动物学报 53(3):431-436,2007].%Seasonal and climatic changes influence the diet of the barn owl Tyto alba throughout its range. We conducted the first long-term study in Pakistan to understand seasonal changes in the diet of this raptor. Regurgitated pellets (n=2 360) were collected for three years from six districts of central Punjab. An analysis of these pellets revealed that the barn owl depended mainly on small mammals (95.6%) for its food. The house shrew Suncus murinus was the main food item (65.6%) in its diet. It was the most common prey item in winter (78%) and was consumed the least during summer (27%). This seasonal rise and fall in the frequency of shrews in the diet was related to an inverse pattern of rise and fall in the frequency of rodents, birds and bats. Small mammals contributed 99% of the biomass consumed by the barn owl[Acta Zoologica Sinica 53(3):431-436,2007].

  16. Fusion reactor materials

    International Nuclear Information System (INIS)

    This is the fifteenth in a series of semiannual technical progress reports on fusion reactor materials. This report combines research and development activities which were previously reported separately in the following progress reports: Alloy Development for Irradiation Performance; Damage Analysis and Fundamental Studies; Special purpose Materials. These activities are concerned principally with the effects of the neutronic and chemical environment on the properties and performance of reactor materials; together they form one element of the overall materials programs being conducted in support of the Magnetic Fusion Energy Program of the U.S. Department of Energy. The Fusion Reactor Materials Program is a national effort involving several national laboratories, universities, and industries. The purpose of this series of reports is to provide a working technical record for the use of the program participants, and to provide a means of communicating the efforts of materials scientists to the rest of the fusion community, both nationally and worldwide

  17. Chernobyl reactor accident

    International Nuclear Information System (INIS)

    On April 26, 1986, an explosion occurred at the newest of four operating nuclear reactors at the Chernobyl site in the USSR. The accident initiated an international technical exchange of almost unprecedented magnitude; this exchange was climaxed with a meeting at the International Atomic Energy Agency in Vienna during the week of August 25, 1986. The meeting was attended by more than 540 official representatives from 51 countries and 20 international organizations. Information gleaned from that technical exchange is presented in this report. A description of the Chernobyl reactor, which differs significantly from commercial US reactors, is presented, the accident scenario advanced by the Russian delegation is discussed, and observations that have been made concerning fission product release are described

  18. International Thermonuclear Experimental Reactor

    International Nuclear Information System (INIS)

    An international design team comprised of members from Canada, Europe, Japan, the Soviet Union, and the United States of America, are designing an experimental fusion test reactor. The engineering and testing objectives of this International Thermonuclear Experimental Reactor (ITER) are to validate the design and to demonstrate controlled ignition, extended burn of a deuterium and tritium plasma, and achieve steady state using technology expected to be available by 1990. The concept maximizes flexibility while allowing for a variety of plasma configurations and operating scenarios. During physics phase operation, the machine produces a 22 MA plasma current. In the technology phase, the machine can be reconfigured with a thicker shield and a breeding blanket to operate with an 18 MA plasma current at a major radius of 5.5 meters. Canada's involvement in the areas of safety, facility design, reactor configuration and maintenance builds on our internationally recognized design and operational expertise in developing tritium processes and CANDU related technologies

  19. Licensed operating reactors

    International Nuclear Information System (INIS)

    The US Nuclear Regulatory Commission's monthly Licensed Operating Reactors Status Summary Report provides data on the operation of nuclear units as timely and accurately as possible. This information is collected by the Office of Information Resources Management, from the Headquarters Staff of NRC's Office of Inspection and Enforcement, from NRC's Regional Offices, and from utilities. This report is divided into three sections: the first contains monthly highlights and statistics for commercial operating units, and errata from previously reported data; the second is a compilation of detailed information on each unit, provided by NRC Regional Offices, IE Headquarters and the Utilities; and the third section is an appendix for miscellaneous information such as spent fuel storage capability, reactor years of experience and non-power reactors in the United States

  20. Licensed operating reactors

    International Nuclear Information System (INIS)

    THE OPERATING UNITS STATUS REPORT - LICENSED OPERATING REACTORS provides data on the operation of nuclear units as timely and accurately as possible. This information is collected by the Office of Information Resources Management from the Headquarters staff of NRC's Office of Enforcement (OE), from NRC's Regional Offices, and from utilities. The three sections of the report are: monthly highlights and statistics for commercial operating units, and errata from previously reported data; a compilation of detailed information on each unit, provided by NRC's Regional Offices, OE Headquarters and the utilities; and an appendix for miscellaneous information such as spent fuel storage capability, reactor-years of experience and non-power reactors in the US