44 research outputs found

    Comparing active and passive Bonner Sphere Spectrometers in the 2.5 MeV quasi mono-energetic neutron field of the ENEA Frascati Neutron Generator (FNG)

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    Bonner Sphere Spectrometer (BSS) equipped with passive detectors are used to replace active BSS in radiation environment characterized by high fluence rate, large photon background and pulsed time structure as those encountered near particle accelerators. In this work a newly developed passive Bonner Sphere Spectrometer, using Dysprosium activation foils as central detectors (Dy-BSS), was tested through comparison with a well-established active BSS. As a suitable neutron field, where both systems can correctly operate, the 2.5 MeV quasi mono-energetic beam of the ENEA Frascati Neutron Generator (FNG) was chosen. The two spectrometers are based on substantially different operation principles, therefore their response matrix are very different. In addition, the BSS are independently calibrated in different reference neutron fields. The exercise took place at 90 � and at a fixed distance from the neutron emitting deuterated target. As reference data, the results obtained by unfolding the active BSS data were used. The FRUIT unfolding code, ver. 5 was used. The results of the Dy-BSS are fully comparable with those of the active BSS, in terms of both total fluence and shape of the neutron spectra. For the energy range studied in this exercise, the expected level of accuracy of the Dy-BSS and its suitability for operational neutron monitoring are fully confirmed

    Design and validation of a photon insensitive multidetector neutron spectrometer based on Dysprosium activation foils

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    Abstract This communication describes a photon insensitive passive neutron spectrometer consisting of Dysprosium (Dy) activation foils located along three perpendicular axes within a single moderating polyethylene sphere. The Monte Carlo code MCNPX 2.6 was used to optimize the spatial arrangement of the detectors and to derive the spectrometer response matrix. Nearly isotropic response in terms of neutron fluence for energies up to 20 MeV was obtained by combining the readings of the detectors located at the same radius value. The spectrometer was calibrated using a previously characterized 14 MeV neutron beam produced in the ENEA Frascati Neutron Generator (FNG). The overall uncertainty of the spectrometer response matrix at 14 MeV, assessed on the basis of this experiment, was ±3%

    Mixed n–γ fields dosimetry at low doses by means of different solid state dosimeters

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    Abstract A Mock-up of the inboard shield of the ITER International nuclear fusion reactor was realized at the Frascati Neutron Generator (FNG) at ENEA Frascati with the scope to measure the nuclear heating (total dose) in the superconducting coils. High sensitivity MCP-6 and MCP-7 dosimeters were used to measure the low

    Effect of inclusion of sodium butyrate, calcium propionate or sodium monensin in the starter feed on ruminal parameters and forestomach development in dairy calves

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    O objetivo neste trabalho foi avaliar o efeito da inclusão de butirato de sódio, monensina sódica ou propionato de cálcio no concentrado inicial sobre parâmetros ruminais e de desenvolvimento do trato digestório superior de bezerros leiteiros. Quinze bezerros holandeses recém-nascidos foram fistulados no rúmen e alojados em baias individuais até a décima semana de vida, com livre acesso a água, alimentados com leite (4 L/dia), em duas refeições, e concentrado à vontade contendo butirato de sódio (0,15%), monensina sódica (30 ppm) ou propionato de cálcio (0,15%). A partir da quarta semana de vida dos animais, antes e 2 horas após a alimentação da manhã, foram realizadas colheitas semanais de fluido ruminal para determinação do pH, da concentração de ácidos graxos de cadeia curta (AGCC) e N-amoniacal. Ao completar 10 semanas, os animais foram abatidos para avaliação do crescimento do trato digestório superior. O pH ruminal apresentou diferenças, tanto entre horários quanto entre os aditivos utilizados no concentrado inicial. As concentrações de AGCC totais, bem como de cada ácido graxo, não foram afetadas pelos aditivos. Entretanto, o horário de colheita teve efeito sobre todos os parâmetros, exceto a concentração molar de ácido acético. O peso total do trato digestório superior, assim como o peso médio de cada compartimento e a capacidade máxima do retículo-rúmen, não foram afetados pelos aditivos fornecidos no concentrado. Também não foram observados efeitos dos aditivos sobre a altura, a largura e o número de papilas do epitélio ruminal. A inclusão desses aditivos no concentrado inicial não afeta os parâmetros ruminais ou de desenvolvimento do trato digestório de bezerros em aleitamento.The objective of this study was the evaluation of the inclusion of calcium propionate, sodium butyrate and sodium monensin in the starter concentrate on ruminal parameters and forestomach development in dairy calves. Fifteen newborn Holstein calves were rumen cannulated and housed in individual stalls until ten weeks old, with free access to water, fed 4 liters of milk per day, split in two meals, and starter concentrate ad libitum containing sodium butyrate (0.15%), sodium monensin (30 ppm) or calcium propionate (0.15%). Starting at the fourth week of life, before and 2 hours after the morning feeding, ruminal fluid samples were taken weekly to determine the pH, short-chain fatty acids and ammonia-N. After 10 weeks, the animals were slaughtered to assess the forestomach growth. The rumen pH was affected by sampling time and the additives used in the starter concentrate. The total short-chain fatty acids concentration and each fatty acid concentration, were was not affected by the additives. However, except for molar concentration of acetic acid, all rumen fermentation parameters were affected by sampling time. The total forestomach weight and the average weight of each compartment and the maximum reticulum-rumen capacity were not affected by additives supplied in the starter concentrate. No significant effects of the additives were observed on the height, width and number of papillae of the ruminal epithelium. The inclusion of these additives in starter concentrate had no effect on most of the ruminal parameters and forestomach development in suckling calves.FAPES

    Campanha preventiva do uso de álcool entre motoristas na estrada

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    O uso abusivo de álcool entre motoristas é um tema preocupante devido às graves consequências e aos altos índices de acidentes de trânsito que tem gerado. O estudo tem como objetivo identifi car os níveis de risco do uso de álcool entre motoristas de caminhão participantes de uma campanha de saúde na estrada em Ribeirão Preto–SP. O desenho metodológico é do tipo descritivo, foi realizado nos meses de agosto e novembro de 2007, e maio de 2008. A amostra contou com 826 (100%) motoristas de caminhão, caracterizados predominantemente pelo sexo masculino, casados ou em união consensual, com baixo nível de escolaridade, católicos, procedentes da região Sudeste. Quanto ao uso de álcool, 73,3% consumiram nos últimos doze meses, sendo que o padrão de consumo ocorreu em um terço da amostra em níveis de uso de risco, ou seja, consomem três a quatro doses, numa frequência de duas a quatro vezes por mês. Considerados índices preocupantes, pois se trata de motoristas que permanecem muitas horas nas estradas. Esses dados fornecem subsídios para o desenvolvimento e manutenção de campanhas preventivas sobre o beber e dirigir.The abusive use of alcohol among drivers is a worrying theme because the serious consequences and the high level of traffi c accidents that produced. This study aimed to identify the levels of risk use of alcohol among truck drivers participats of a health campaign on the roads in Ribeirão Preto–SP. The methodological design is a descriptive study was carried out in August and November of 2007 and also May of 2008. The sample was composed of 826 (100%) of truck drivers, predominantly male, married or in consensual union with low schooling level, catholic, precedents of Southeast of Brazil. Regarding the alcohol use, 73% drunk in the last twelve month, than, that pattern of consumption happened in one third of the sample in level of risk use that is three and four drinks used in a frequency of two and four times per month. These fi gures are remarkably high, considering that drivers stay many hours driving. Those data provide support to development and maintenance of preventive campaign on drinking and driving

    Neutron Detectors Based Upon Artificial Single Crystal Diamond

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    This paper reports about state-of-the-art artificial Single Crystal Diamond (SCD) neutron detectors based on a multilayered structure and grown by chemical vapour deposition (CVD) technique. Multilayered SCD detectors covered with a thin layer of 6LiF allow the simultaneous detection of both slow and fast neutrons and can operate in pulse and current mode. These detectors can also be produced with a thin layer of Boron. Application of SCD detectors to neutron detection around fusion tokamak is reported. Some problems related to the processing of the very fast electrical pulse produced by diamond are addressed and the achieved and foreseen development of the processing electronics is reported as well

    Management of Pediatric Urinary Tract Infections: A Delphi Study

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    Urinary tract infection (UTI) is one of the most common infectious diseases in the pediatric population and represents a major cause of antibiotic consumption and hospitalization in children. Considering the ongoing controversies on the management of pediatric UTI and the challenges due to increasing antimicrobial resistance, the aim of the present study was to evaluate the level of agreement on UTI management in pediatric age in Emilia-Romagna Region, Italy, and to assess on the basis of recent studies whether there is the need to change current recommendations used by primary care pediatricians, hospital pediatricians, and pediatric surgeons in everyday clinical practice to possibly improve outcomes. This consensus provides clear and shared indications on UTI management in pediatric age, based on the most updated literature. This work represents, in our opinion, the most complete and up-to-date collection of statements on procedures to follow for pediatric UTI, in order to guide physicians in the management of the patient, standardize approaches, and avoid abuse and misuse of antibiotics. Undoubtedly, more randomized and controlled trials are needed in the pediatric population to better define the best therapeutic management in cases with antimicrobial resistance and real usefulness of long-term antibiotic prophylaxis

    New Mediterranean Biodiversity Records (December 2019)

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    This paper is a collection of novel distributional records of 20 species belonging to 8 phyla (Chlorophyta, Rhodophyta, Cnidaria, Ctenophora, Annelida, Mollusca, Arthropoda and Chordata) from 11 Mediterranean countries, namely, Spain: an additional record of the Canary dentex Dentex canariensis is reported from Spain (Valencia), this is the northernmost record of this species in the Mediterranean; Algeria: the first documented record of Caulerpa chemnitzia is reported from the Algerian coast; France: the first record of the Spotted sea hare Aplysia dactylomela is reported from the eastern coast of Corsica; Italy: the first records of the Lessepsian polychaete Dorvillea similis and the alien bivalve Isognomon legumen are reported from Italian waters while additional records of Mnemiopsis leidyi in the south Adriatic are provided;  Libya: the first record of an alien mollusc Crepidula fornicata is reported from Libyan waters; Malta: multiple sightings of gelatinous species Apolemia uvaria, Phacellophora camtschatica and Physophora hydrostatica are reported for the first time from Maltese waters, as well as the first tentative record of the Orange-spotted grouper Epinephelus cfr. coioides; Greece: an occurrence of a rare Bigeye thresher shark Alopias superciliosus is reported from Hellenic Ionian waters, while the first records of the alien Mertens’ prawn-goby Vanderhorstia mertensi, the recently described cyclopoid copepod Oithona davisae and the alien red seaweed Asparagopsis armata are reported from the Aegean Sea. The presence of the micromollusc Euthymella colzumensis is confirmed for Greece; Cyprus: the first record of the red cornetfish Fistularia petimba is reported from Cyprus; Turkey: the first record of the alien jellyfish Marivagia stellata is reported from south-eastern Turkey; Israel: the first records of the sea nettle Chrysaora sp. in the Levant are reported
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