1,563 research outputs found
The solar simulation test of the ITALSAT thermal structural model
The ITALSAT structural/thermal model (STM) was submitted to a solar simulation test in order to verify the spacecraft thermal design and the thermal mathematical model which will be used to predict the on orbit temperatures. The STM was representative of the flight model in terms of configuration, structures, appendages and thermal hardware; dissipating dummy units were used to simulate the electronic units. The test consisted of the main phases: on station (beginning of life), on station (end of life), and transfer orbit. Preliminary results indicate that the test performances were satisfactory. The spacecraft measured temperatures were up to 15 degrees higher than the predicted ones. This imposes a careful correlation analysis in order to have reliable flight temperature predictions
Feasibility limits of using low-grade industrial waste heat in symbiotic district heating and cooling networks
Abstract: Low-grade waste heat is an underutilized resource in process industries, which may consider investing in urban symbiosis projects that provide heating and cooling to proximal urban areas through district energy networks. A long distance between industrial areas and residential users is a barrier to the feasibility of such projects, given the high capital intensity of infrastructure, and alternative uses of waste heat, such as power generation, may be more profitable, in spite of limited efficiency. This paper introduces a parametric approach to explore the economic feasibility limits of waste heat-based district heating and cooling (DHC) of remote residential buildings depending on network extension. A parametric model for the comparative water\u2013energy\u2013carbon nexus analysis of waste heat-based DHC and Organic Rankine Cycles is also introduced, and applied to an Italian and to an Austrian setting. The results show that, for a generic 4\ua0MW industrial waste heat flow steadily available at 95\ua0\ub0C, district heating and cooling is the best option from an energy\u2013carbon perspective in both countries. Power generation is the best option in terms of water footprint in most scenarios, and is economically preferable to DHC in Italy. Maximum DHC feasibility threshold distances are in line with literature, and may reach up to 30\ua0km for waste heat flows of 30\ua0MW in Austria. However, preferability threshold distances, above which waste heat-to-power outperforms DHC from an economic viewpoint, are shorter, in the order of 20\ua0km in Austria and 10\ua0km in Italy for 30\ua0MW waste heat flows. Graphic abstract: [Figure not available: see fulltext.]
Development of scaffold-free vascularized pancreatic beta-islets in vitro models by the anchoring of cell lines to a bioligand-functionalized gelatine substrate
Bioengineered pancreatic β-islets have been widely advocated for the research and treatment of diabetes by offering both suitable cell culture models for the study of the pathology and the testing of new drugs and a therapy in those patients no longer responding to insulin administration and as an alternative to the shortage of donors for organ and islet transplantation. Unlike most of the studies published so far where pancreatic islets of pancreatic β-cells are encapsulated in hydrogels, this study demonstrate the formation of bioengineered pancreatic islets through cell anchoring to a gelatine-based biomaterial, PhenoDrive-Y, able to mimic the basement membrane of tissues. Through simple culture conditions, PhenoDrive-Y led human pancreatic β-cell lines and human umbilical endothelial cell lines to form organized structures closely resembling the natural vascularized pancreatic islets. When compared to gelatine, the cultures in presence of PhenoDrive-Y show higher degree of organization in tissue-like structures, a more pronounced endothelial sprouting and higher expression of typical cell markers. Noticeably, when challenged by hyperglycaemic conditions, the cells embedded in the PhenoDrive-Y assembled spheroids responded with higher levels of insulin production. In conclusion, the present work demonstrates the potential of PhenoDrive-Y as substrate for the development of bioengineered vascularized pancreatic islets and to be particularly suitable as a model for in vitro studies and testing of new therapeutics. [Figure: see text
Where does a glacier end? Integrated geophysical, geomorphological and photogrammetric measurements to image geometry and ice facies distribution
In this study we integrated different techniques, spanning from Ground Penetrating Radar to geomorphological and photogrammetric data, to characterize the glacial and proglacial environments of the Sforzellina Glacier (Central Alps, Italy). Direct data highlighted the presence of debris-covered ice and even of dead ice patches in front of the actual glacier terminus. Such an information was further proved by geophysical data. We try to correlate the dead ice patches occurrence with several parameters such as debris cover thickness, ground tem- perature, solar radiation, elevation, velocity of glacier retreat, and dip of the topographic surface without finding relevant correlations, except for the local bedrock morphology. In fact, the latter factor seems to be crucial to make the favourable conditions to dead ice patches formation and preservation with time. Since ice is not always outcropping, while dead ice patches never outcrop because they are hidden by continuous debris cover, classical glaciological monitoring techniques are not always successfully applicable. On the basis of the obtained results, we argue that estimates of glacier extension just related to surficial in- formation, like in the case of exclusive use of remote sensing data and outcropping ice monitoring, can produce relevant underestimations. The presence of hidden ice patches, even not strictly part of the glacier body, is further important to quantify the total water equivalent, as well as to make affordable forecasts of the future glaciers evolution
Investigations of polygonal patterned ground in continuous Antarctic permafrost by means of ground penetrating radar and electrical resistivity tomography: Some unexpected correlations
The results of a combined geophysical and geomorphological investigation of thermal-contraction-crack polygons near Gondwana station (Germany) in northern Victoria Land (Antarctica) are reported. An area of about 20,000 m2 characterized by random orthogonal polygons was investigated using integrated ground penetrating radar, electrical resistivity tomography, geomorphological surveys, and two trench excavations. The polygons are well developed only at elevations higher than 6–7 m above current sea level on Holocene-age raised beaches. It is concluded that the polygons are composite in nature because the shallow linear depressions that outline the polygons are underlain by fissures that can contain both sandy gravel and foliated ice (i.e., ice wedges) even in the same polygon network and at distances of just a few meters. Unexpectedly, most of the polygons follow the border of the raised beaches and develop in correspondence with stratigraphic layers dipping toward the sea, imaged by ground penetrating radar (GPR) profiles and interpreted as prograding layers toward the present-day shoreline
Event-based control of basic wastewater treatment plant control loops
[Abstract] This paper addresses the problem of basic control loops in wastewater treatment plants. By basic control loops we are referring to the traditional dissolved oxygen and nitrates. They are the basic controls more sophisticated control solutions can be based upon. Therefore it is important that these loops perform in an efficient way. The problem is addressed here within the framework provided by the Benchmark Simulation Model Number 1 (BSM1) and by the use of an event-based solution. It will be verified that the solution can slightly improve the performance of the already exiting controllers both at loop level as well as at plant operation level.[Resumen] Este documento aborda el problema de los bucles de control básicos en las plantas de tratamiento de aguas residuales. Por bucles de control básicos nos referimos a los tradicionales disueltos de oxígeno y nitratos. Son los controles básicos en los que se pueden basar las soluciones de control más sofisticadas. Por lo tanto, es importante que estos bucles funcionen de manera eficiente. El problema se aborda aquí dentro del marco provisto por el Número de modelo de simulación de referencia (BSM1) y por el uso de una solución basada en eventos. Se verificará que la solución puede mejorar ligeramente el rendimiento de los controladores que ya existen, tanto a nivel de bucle como a nivel de operación de la planta
A Josephson relation for fractionally charged anyons.
Anyons occur in two-dimensional electron systems as excitations with fractional charge in the topologically ordered states of the fractional quantum Hall effect (FQHE). Their dynamics are of utmost importance for topological quantum phases and possible decoherence-free quantum information approaches, but observing these dynamics experimentally is challenging. Here, we report on a dynamical property of anyons: the long-predicted Josephson relation f J = e*V/h for charges e* = e/3 and e/5, where e is the charge of the electron and h is Planck's constant. The relation manifests itself as marked signatures in the dependence of photo-assisted shot noise (PASN) on voltage V when irradiating contacts at microwaves frequency f J The validation of FQHE PASN models indicates a path toward realizing time-resolved anyon sources based on levitons
Low knowledge and awareness of monoclonal gammopathy of undetermined significance (MGUS) among general practitioners
Acknowledgements The authors would like to take this opportunity to thank the organisers of the WONCA Europe 2017 conference and the General Practitioners/Trainee’s for participating in this study. Funding At the time of writing, Dr Charlene McShane was in receipt of a Cancer Research UK Population Science Postdoctoral Research Fellowship (C51094/A18267)Peer reviewedPublisher PD
Carbon and water footprint of energy saving options for the air conditioning of electric cabins at industrial sites
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