733 research outputs found

    Development of a gas absorption heat pump for residential applications

    Get PDF
    Thermally Driven Heat Pumps represent an option to reduce the energy consumption for space heating and domestic hot water in hard-to-decarbonize buildings without impacting the electrical grid and utilizing the current and future gaseous energy vectors with high efficiency. Ariston Group and Politecnico di Milano developed a gas absorption heat pump for the residential market, exploiting design and manufacturing solutions to enable large-scale production and introducing technical features to assure high performance over the entire working range. In particular, the use of a variable restrictor setup coupled with a patented solution, called “booster”, can reduce the temperature of the generator at high load and high lift conditions, enabling the heat pump to provide the nominal capacity from -22 °C to +40 °C of outdoor air temperature, with supply temperature up to 70 °C. Moreover, coupled with a specifically designed combustion system, the heat pump can modulate at 1:6 ratio of its nominal capacity. This feature makes it possible to maintain high efficiency also at part load conditions, avoiding the on-off operation and making redundant the installation of inertial buffer. Additionally, an innovative strategy to perform the defrosting of the air-sourced heat exchanger without the need of acting on the thermodynamic cycle has been developed. This allows defrosting operations extremely fast, while offering an almost negligible effect on the heat pump performance and substantially no interruption to the heating service and contributing to the elimination of the need to install an inertial buffer. The thermodynamic core of the appliance was built targeting large scale production. It allows for high specific capacity (kg/kW) and a small footprint (m2/kW) with the ability to serve nominal capacities ranging from 8 to 15 kW based on the configurations. Laboratory test to assess the performances based on the European Standard EN 12309 returned a seasonal gas utilization efficiency on the net calorific of 1.50, a seasonal primary energy ratio of 1.27, and extremely low electrical consumption for the auxiliaries

    Exhumation of the Sierra de Cameros (Iberian Range, Spain): constraints from low-temperature thermochronology

    Get PDF
    We present new fission-track and (U–Th)/He data from apatite and zircon in order to reconstruct the exhumation of the Sierra de Cameros, in the northwestern part of Iberian Range, Spain. Zircon fission-track ages from samples from the depocentre of the basin were reset during the metamorphic peak at approximately 100 Ma. Detrital apatites from the uppermost sediments retain fission-track age information that is older than the sediment deposition age, indicating that these rocks have not exceeded 110 8C. Apatites from deeper in the stratigraphic sequence of the central part of the basin have fission-track ages of around 40 Ma, significantly younger than the stratigraphic age, recording the time of cooling after peak metamorphic conditions. Apatite (U–Th)/He ages in samples from these sediments are 31–40 Ma and record the last period of cooling during Alpine compression. The modelled thermal history derived from the uppermost sediments indicates that the thermal pulse associated with peak metamorphism was rapid, and that the region has cooled continuously to the present. The estimated palaeogeothermal gradient is around 86 8C km21 and supports a tectonic model with a thick sedimentary fill (c. 8 km) and explains the origin of the low-grade metamorphism observed in the oldest sediments

    CLEMSite, a software for automated phenotypic screens using light microscopy and FIB-SEM

    Get PDF
    This work was supported by EMBL funds and by by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – Project number 240245660 – SFB 1129 (project Z2).In recent years, Focused Ion Beam Scanning Electron Microscopy (FIB-SEM) has emerged as a flexible method that enables semi-automated volume ultrastructural imaging. We present a toolset for adherent cells that enables tracking and finding cells, previously identified in light microscopy (LM), in the FIB-SEM, along with the automatic acquisition of high-resolution volume datasets. We detect the underlying grid pattern in both modalities (LM and EM), to identify common reference points. A combination of computer vision techniques enables complete automation of the workflow. This includes setting the coincidence point of both ion and electron beams, automated evaluation of the image quality and constantly tracking the sample position with the microscope’s field of view reducing or even eliminating operator supervision. We show the ability to target the regions of interest in EM within 5 µm accuracy while iterating between different targets and implementing unattended data acquisition. Our results demonstrate that executing volume acquisition in multiple locations autonomously is possible in EM.Publisher PDFPeer reviewe

    Microbial characteristics in homes of asthmatic and non-asthmatic adults in the ECRHS cohort

    Get PDF
    Microbial exposures in homes of asthmatic adults have been rarely investigated; specificities and implications for respiratory health are not well understood. The objectives of this study were to investigate associations of microbial levels with asthma status, asthma symptoms, bronchial hyperresponsiveness (BHR), and atopy. Mattress dust samples of 199 asthmatics and 198 control subjects from 7 European countries participating in the European Community Respiratory Health Survey II study were analyzed for fungal and bacterial cell wall components and individual taxa. We observed trends for protective associations of higher levels of mostly bacterial markers. Increased levels of muramic acid, a cell wall component predominant in Gram-positive bacteria, tended to be inversely associated with asthma (OR's for different quartiles: II 0.71 [0.39-1.30], III 0.44 [0.23-0.82], and IV 0.60 [0.31-1.18] P for trend .07) and with asthma score (P for trend .06) and with atopy (P for trend .02). These associations were more pronounced in northern Europe. This study among adults across Europe supports a potential protective effect of Gram-positive bacteria in mattress dust and points out that this may be more pronounced in areas where microbial exposure levels are generally lower.Peer reviewe

    Soft capacitor fibers using conductive polymers for electronic textiles

    Full text link
    A novel, highly flexible, conductive polymer-based fiber with high electric capacitance is reported. In its crossection the fiber features a periodic sequence of hundreds of conductive and isolating plastic layers positioned around metallic electrodes. The fiber is fabricated using fiber drawing method, where a multi-material macroscopic preform is drawn into a sub-millimeter capacitor fiber in a single fabrication step. Several kilometres of fibers can be obtained from a single preform with fiber diameters ranging between 500um -1000um. A typical measured capacitance of our fibers is 60-100 nF/m and it is independent of the fiber diameter. For comparison, a coaxial cable of the comparable dimensions would have only ~0.06nF/m capacitance. Analysis of the fiber frequency response shows that in its simplest interrogation mode the capacitor fiber has a transverse resistance of 5 kOhm/L, which is inversely proportional to the fiber length L and is independent of the fiber diameter. Softness of the fiber materials, absence of liquid electrolyte in the fiber structure, ease of scalability to large production volumes, and high capacitance of our fibers make them interesting for various smart textile applications ranging from distributed sensing to energy storage

    Interaction of the human cytomegalovirus uracil DNA glycosylase UL114 with the viral DNA polymerase catalytic subunit UL54

    Get PDF
    Interaction between human cytomegalovirus uracil DNA glycosylase (UL114) and the viral DNA polymerase accessory subunit (UL44) has been reported; however, no such association was found in proteomic studies of UL44-interacting proteins. Utilizing virus expressing FLAG-tagged UL114, nuclease-resistant association of UL44 and the DNA polymerase catalytic subunit UL54 with UL114 was observed by co-immunoprecipitation. Contrary to a previous report, we observed that UL114 was much less abundant than UL44. Interaction of UL114 with UL54, independent of the UL54 carboxyl terminus, but not with UL44 was detected in vitro. Our data are consistent with a direct UL114–UL54 interaction, and suggest that UL114 and UL54 act in concert during base excision repair of the viral genome

    Syngeneic transplantation in aplastic anemia: pre-transplant conditioning and peripheral blood are associated with improved engraftment: an observational study on behalf of the Severe Aplastic Anemia and Pediatric Diseases Working Parties of the European Group for Blood and Marrow Transplantation

    Full text link
    Aplastic anemia is usually treated with immunosuppression or allogeneic transplant, depending on patient and disease characteristics. Syngeneic transplant offers a rare treatment opportunity with minimal transplant-related mortality, and offers an insight into disease mechanisms. We present here a retrospective analysis of all syngeneic transplants for aplastic anemia reported to the European Group for Blood and Marrow Transplantation. Between 1976 and 2009, 88 patients received 113 transplants. Most transplants (n=85) were preceded by a conditioning regimen, 22 of these including anti-thymocyte globulin. About half of transplants with data available (39 of 86) were followed by posttransplant immunosuppression. Graft source was bone marrow in the majority of cases (n=77). Transplant practice changed over time with more transplants with conditioning and anti-thymocyte globulin as well as peripheral blood stem cells performed in later years. Ten year overall survival was 93% with 5 transplant-related deaths. Graft failure occurred in 32% of transplants. Risk of graft failure was significantly increased in transplants without conditioning, and with bone marrow as graft source. Lack of posttransplant immunosuppression also showed a trend towards increased risk of graft failure, while anti-thymocyte globulin did not have an influence. In summary, syngeneic transplant is associated with a significant risk of graft failure when no conditioning is given, but has an excellent long-term outcome. Furthermore, our comparatively large series enables us to recommend the use of pre-transplant conditioning rather than not and possibly to prefer peripheral blood as a stem cell source
    • …
    corecore