91 research outputs found

    An EBIS for charge state breeding in the SPES project

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    The 'charge state breeder', BRIC (breeding ion charge) is in construction at the INFN section of Bari (Italy). It is based on EBIS scheme and it is designed to accept radioactive ion beam (RIB) with charge state +1 in a slow injection mode. This experiment can be considered as a first step towards the design and construction of a charge breeder for the SPES project. The new feature of BRIC, with respect to the classical EBIS, is given by the insertion, in the ion chamber, of a rf-quadrupole aiming at filtering the unwanted masses and then making a more efficient containment of the wanted ions. In this paper, the breeder design, the simulation results of the electron and ion beam propagation and the construction problems of the device will be reported

    Экспериментальное исследование теплогидравлических характеристик оребренных плоских труб аппарата воздушного охлаждения масла

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    Air cooling devices are heat exchange units that are widely used in practice. However, they have a number of disadvantages due to the low value of the heat transfer coefficient from the air and the high resistance of finned tube bundles, which leads to large dimensions and the metal content of the device itself, to the need to develop a high power ventilator drive, but also to the need to demonstrate reduced energy efficiency. The objective of the present work is to determine optimal geometric sizes of finned flat heat exchange tubes manufactured by the techniques of extrusion and deforming cutting that reduce the weight and size characteristics of the heat exchange section of air cooling devices. The experimental studies of seven various samples of heat exchange sections, being different in fin pitch and height, tube section width, flat tube height and a number of inner channels, have determined the performance of each section with the use of the following criteria: thermal power, thermal efficiency, specific thermal heat transfer resistance, M. V. Kirpichev and V. M. Antuf’ev’s criteria. The obtained experimental data and the analysis of the passive method of enhancement in the near-wall area of the heat transfer surface finned by deforming cutting has shown that sample No 5 has maximum value of the performance criteria when the maximum height of a fin is 0.008 m and the minimum pitch of a fin is 0.0025 m over the investigated sample range. Thus, when the sizes of an oil air cooling device are maintained by using the amended heat transfer section of sample No 5, the amount of removed heat can be increased or the mass and dimensions of the device can be decreased while maintaining thermal power and, as a result, the power consumption for pumping can be decreased and the thermal-hydraulic performance of the device as a whole can be increased.Аппараты воздушного охлаждения представляют собой класс теплообменных агрегатов, широко применяемых на практике. Однако они обладают рядом недостатков, обусловленных малым значением коэффициента теплоотдачи со стороны воздуха и большим сопротивлением оребренных трубных пучков. Это приводит к большим габаритам и металлоемкости самого устройства, к необходимости развивать высокую мощность привода вентилятора, что снижает энергетическую эффективность. Цель исследований – определение оптимальных геометрических размеров оребренных плоских теплообменных труб, получаемых методами экструзии и деформирующего резания, обеспечивающих снижение массогабаритных характеристик теплообменной секции аппаратов воздушного охлаждения. На основании проведенных экспериментов с семью различными образцами теплообменных секций, отличающихся шагом и высотой ребер, шириной секции трубы, высотой плоской трубы и количеством внутренних каналов, установлена эффективность каждой секции по таким показателям, как: тепловая мощность, тепловая эффективность, удельное термическое сопротивление теплопередаче, критерии М. В. Кирпичева и В. М. Антуфьева. Полученные экспериментальные данные и анализ пассивного метода воздействия на пристенную область теплопередающей поверхности за счет оребрения методом деформирующего резания показывают, что максимальное значение критериев эффективности наблюдается у образца № 5 с наибольшей высотой (0,008 м) и минимальным шагом ребер (0,0025 м) в исследованном диапазоне. Таким образом, при сохранении геометрических размеров аппарата воздушного охлаждения масла за счет использования улучшенной секции теплообменного аппарата (образец № 5) возможно увеличение количества отводимой теплоты или уменьшение массогабаритных характеристик при сохранении тепловой мощности и, как следствие, снижение затрат мощности на прокачку и повышение теплогидравлической эффективности аппарата в целом

    Global monitoring of soil animal communities using a common methodology.

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    Here we introduce the Soil BON Foodweb Team, a cross-continental collaborative network that aims to monitor soil animal communities and food webs using consistent methodology at a global scale. Soil animals support vital soil processes via soil structure modification, consumption of dead organic matter, and interactions with microbial and plant communities. Soil animal effects on ecosystem functions have been demonstrated by correlative analyses as well as in laboratory and field experiments, but these studies typically focus on selected animal groups or species at one or few sites with limited variation in environmental conditions. The lack of comprehensive harmonised large-scale soil animal community data including microfauna, mesofauna, and macrofauna, in conjunction with related soil functions, microbial communities, and vegetation, limits our understanding of biological interactions in soil systems and how these interactions affect ecosystem functioning. To provide such data, the Soil BON Foodweb Team invites researchers worldwide to use a common methodology to address six long-term goals: (1) to collect globally representative harmonised data on soil micro-, meso-, and macrofauna communities, (2) to describe key environmental drivers of soil animal communities and food webs, (3) to assess the efficiency of conservation approaches for the protection of soil animal communities, (4) to describe soil food webs and their association with soil functioning globally, (5) to establish a global research network for soil biodiversity monitoring and collaborative projects in related topics, (6) to reinforce local collaboration networks and expertise and support capacity building for soil animal research around the world. In this paper, we describe the vision of the global research network and the common sampling protocol to assess soil animal communities and advocate for the use of standard methodologies across observational and experimental soil animal studies. We will use this protocol to conduct soil animal assessments and reconstruct soil food webs at sites associated with the global soil biodiversity monitoring network, Soil BON, allowing us to assess linkages among soil biodiversity, vegetation, soil physico-chemical properties, climate, and ecosystem functions. In the present paper, we call for researchers especially from countries and ecoregions that remain underrepresented in the majority of soil biodiversity assessments to join us. Together we will be able to provide science-based evidence to support soil biodiversity conservation and functioning of terrestrial ecosystems

    Regional variability in peatland burning at mid- to high-latitudes during the Holocene

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    Acknowledgements This work developed from the PAGES (Past Global Changes) C-PEAT (Carbon in Peat on EArth through Time) working group. PAGES has been supported by the US National Science Foundation, Swiss National Science Foundation, Swiss Academy of Sciences and Chinese Academy of Sciences. We acknowledge the following financial support: UK Natural Environment Research Council Training Grants NE/L002574/1 (T.G.S.) and NE/S007458/1 (R.E.F.); Dutch Foundation for the Conservation of Irish Bogs, Quaternary Research Association and Leverhulme Trust RPG-2021-354 (G.T.S); the Academy of Finland (M.V); PAI/SIA 80002 and FONDECYT Iniciación 11220705 - ANID, Chile (C.A.M.); R20F0002 (PATSER) ANID Chile (R.D.M.); Swedish Strategic Research Area (SRA) MERGE (ModElling the Regional and Global Earth system) (M.J.G.); Polish National Science Centre Grant number NCN 2018/29/B/ST10/00120 (K.A.); Russian Science Foundation Grant No. 19-14-00102 (Y.A.M.); University of Latvia Grant No. AAp2016/B041/Zd2016/AZ03 and the Estonian Science Council grant PRG323 (TrackLag) (N.S. and A.M.); U.S. Geological Survey Land Change Science/Climate Research & Development Program (M.J., L.A., and D.W.); German Research Foundation (DFG), grant MA 8083/2-1 (P.M.) and grant BL 563/19-1 (K.H.K.); German Academic Exchange Service (DAAD), grant no. 57044554, Faculty of Geosciences, University of Münster, and Bavarian University Centre for Latin America (BAYLAT) (K.H.K). Records from the Global Charcoal Database supplemented this work and therefore we would like to thank the contributors and managers of this open-source resource. We also thank Annica Greisman, Jennifer Shiller, Fredrik Olsson and Simon van Bellen for contributing charcoal data to our analyses. Any use of trade, firm, or product name is for descriptive purposes only and does not imply endorsement by the U.S. Government.Peer reviewedPostprin
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