13 research outputs found
A Search for Coincident Neutrino Emission from Fast Radio Bursts with Seven Years of IceCube Cascade Events
This paper presents the results of a search for neutrinos that are spatially and temporally coincident with 22 unique, nonrepeating fast radio bursts (FRBs) and one repeating FRB (FRB 121102). FRBs are a rapidly growing class of Galactic and extragalactic astrophysical objects that are considered a potential source of high-energy neutrinos. The IceCube Neutrino Observatory\u27s previous FRB analyses have solely used track events. This search utilizes seven years of IceCube cascade events which are statistically independent of track events. This event selection allows probing of a longer range of extended timescales due to the low background rate. No statistically significant clustering of neutrinos was observed. Upper limits are set on the time-integrated neutrino flux emitted by FRBs for a range of extended time windows
Preparation and characterization of thin CsAu films
The formation of CsAu films by successive evaporation of gold and caesium atoms onto a clean Ru(001) substrate surface was followed by UV photoelectron spectroscopy and (subsequent) thermal desorption spectroscopy. No compound but only a chemisorbed layer (and eventually bulk caesium) is formed if caesium is deposited onto a gold layer, if the quantity of the latter itself does not exceed the monolayer capacity. With thicker gold layers, on the contrary, semiconducting CsAu (with a band gap of 2.6 eV and the Fermi level close to the conduction band edge) is formed by interdiffusion at T > 250 K, but the outer surface consists always of a layer of chemisorbed caesium. This even holds for a \u201csandwich\u201d system for which a thick gold film was evaporated onto a CsAu layer. The surface region of CsAu is highly reactive towards oxygen
Heat transfer to liquid metals in a hexagonal rod bundle with grid spacers: Experimental and simulation results
Thermal-hydraulics is a key scientific subject to be investigated for the development of innovative reactor systems. For applications using liquid metals as coolants this task is particularly challenging due to their very low Prandtl number (Pr), preventing the application of common analogies between the turbulent transport of momentum and heat. Thus specific models and validation data with low-Pr fluids are required for representing safety-related thermal-hydraulic scenarios, such as heat transfer in fuel assemblies. Aiming to achieve a better understanding of these flow scenarios, in the European FP7 cooperation project THINS (2010-2014) this subject is investigated at three complementary levels. An experimental campaign consisting of an electrically heated 19-pin hexagonal rod bundle cooled by lead-bismuth eutectic (LBE) is carried out at typical reactor conditions in terms of operating temperature, power density and velocity. Both pre- and post-test analyses using existing numerical tools are performed for evaluating the differential pressure and heat transfer characteristics of the test section. Moreover, advanced turbulence models and numerical techniques are developed and applied to this geometry. Overall, the goals of this project are achieved. The experiments show good degree of repeatability and provide reliable validation data. For intermediate flow rates a good agreement is observed with the results of the heat transfer simulations, based on a constant turbulent Prandtl number. Two advanced approaches for representing the turbulent heat transport considering look-up tables and a four-equation model are successfully tested and overcome the limitations of using a constant turbulent Prandtl number. Using a coarse-grid CFD approach the turbulent momentum transport along two bundles is studied, yielding a good accuracy with a 1000-fold mesh reduction
Status and Future of Biomass Assessment for Energetic Use in Europe
Results from biomass potential assessments vary considerably, both on global and European level. On the other hand reliable figures on biomass potentials are an important basis for energy policy and for strategies that aim at an increase of use of biomass for energy both on EU-Level as well as e. g. on national level in the National Renewable Energy Action Plans (NREAPs) by the 27 member states. This paper is based on the findings of two projects, BEE and CEUBIOM. It presents an overview of the findings of these projects and includes an analysis of biomass potential aspects within the NREAPs. It presents how, based on an analysis of the status quo of potential studies, the projects developed proposals for a harmonisation of the methodologies and it presents the key areas they identified for future work in the field
Status and Future of Biomass Assessment for Energetic Use in Europe
Results from biomass potential assessments vary considerably, both on global and European level. On the other hand reliable figures on biomass potentials are an important basis for energy policy and for strategies that aim at an increase of use of biomass for energy both on EU-Level as well as e. g. on national level in the National Renewable Energy Action Plans (NREAPs) by the 27 member states. This paper is based on the findings of two projects, BEE and CEUBIOM. It presents an overview of the findings of these projects and includes an analysis of biomass potential aspects within the NREAPs. It presents how, based on an analysis of the status quo of potential studies, the projects developed proposals for a harmonisation of the methodologies and it presents the key areas they identified for future work in the field
Plato argénteo nº 38.215 . Reverso - ABE0155_AR
Proyectos del Plan Nacional I+D+I con referencias PB94-0129, PB97-1132, BHA 2002-00138, HUM 2006-06250/HISTProyectos de la CAM con referencias 06/0020/1997, 06/0094/1998, 06/0090/2000, 06/0043/2001Programa Consolider-Ingenio 2010 con sigla CSD2007-00058NoMuseo Arqueológico Nacional (Madrid)AbengibrePlato argénteo nº 38.215 . Revers
Limited clinical relevance of imaging techniques in the follow-up of patients with advanced chronic lymphocytic leukemia: results of a meta-analysis
The clinical value of imaging is well established for the follow-up of many lymphoid malignancies but not for chronic lymphocytic leukemia (CLL). A meta-analysis was performed with the dataset of 3 German CLL Study Group phase 3 trials (CLL4, CLL5, and CLL8) that included 1372 patients receiving first-line therapy for CLL. Response as well as progression during follow-up was reassessed according to the National Cancer Institute Working Group1996 criteria. A total of 481 events were counted as progressive disease during treatment or follow-up. Of these, 372 progressions (77%) were detected by clinical symptoms or blood counts. Computed tomography (CT) scans or ultrasound were relevant in 44 and 29 cases (9% and 6%), respectively. The decision for relapse treatment was determined by CT scan or ultrasound results in only 2 of 176 patients (1%). CT scan results had an impact on the prognosis of patients in complete remission only after the administration of conventional chemotherapy but not after chemoimmunotherapy. In conclusion, physical examination and blood count remain the methods of choice for staging and clinical follow-up of patients with CLL as recommended by the International Workshop on Chronic Lymphocytic Leukemia 2008 guidelines. These trials are registered at http://www.isrctn.org as ISRCTN 75653261 and ISRCTN 36294212 and at http://www.clinicaltrials.gov as NCT00281918