Extreme performance of heat exchangers of various hydrodynamic models of flows

The problem of minimization of entropy production is considered for one-pass heat exchangers of various types of description of hydrodynamic characteristics of the flows. Two models of the flows are considered, namely models of ideal mixing and ideal exclusion. The solution of the problem at issue allows one to construct a measure of thermodynamic perfectness of the heat exchanger taking into account the irreversibility of the heat exchange process

Nachhaltige Energieversorgung von Niedrigstenergiehäusern auf Basis der Kraft-Wärme- Kopplung im Kleinstleistungsbereich und der Solarthermie.

Description and assessment of technology-related concepts aiming at improving the energy conservation in residential buildings. Explanation of the method and discussion of the whole-year simulation results for SOFC micro-CHP systems and Stirling engines in relation with single-family houses of different thermal insulation standards. Benchmark with conventional energy supply systems. Computation of allowable investment costsBeschreibung und Beurteilung unter technischen, ökonomischen und ökologischen Gesichtspunkten zweier technologiebasierter Maßnahmen zur Effizienzsteigerung der Energiebereitstellung im Gebäudesektor. Darstellung der verwendeten Methodik und der Simulationsergebnisse am Beispiel von SOFC-Brennstoffzellen-Heizgeräten und Stirling-Motoren in Relation mit Einfamilienhäusern verschiedener Dämmstandards. Vergleich mit herkömmlichen und etablierten Versorgungstechnologien Berechnung von anlegbaren Investitionskosten

The Generation of Domestic Hot Water Load Profiles in Swiss Residential Buildings through Statistical Predictions

A long-term field study recording domestic hot water (DHW) consumption in households was used to tune a load profile generator. The methodology used in this load profile generator is also applicable to electric loads in distribution grids. Accurate DHW load profiles are essential to estimate the performance of renewable energy systems. One day and long-term randomly generated DHW profiles are useful for simulation, sizing and optimization of components in solar hot water installations such as storage tank, heat exchanger, collector area and additional heater. This work is also relevant to create standards for product testing and certification. DHW usage and draw off patterns are geographically dependent, so recent and local measurements are required to tune models and create accurate load profiles. Measurements show that DHW consumption is very volatile. The daily average value varies from 20 to 40 l per person (60 °C outlet temperature). The profiles underlie some trends (predominantly consumption in the morning or in the evening or spread over the day). The DHW consumption in Switzerland follows similar patterns observed in other countries, such as no significant decrease in consumption during weekends, and no strong correlation with weather conditions neither outdoor temperature nor rain

Warmwasser-Kurzentnahmen : Auswirkung und Vermeidung

SchlussberichtDiese Feldstudie untersuchte, wie gross die tatsächliche Wirkung von der Funktion «Mittelstellung kalt» auf den Energieverbrauch in Gebäuden ist und wie die Akzeptanz der Nutzer ist. Dafür wurden zwei verschiedene methodische Ansätze verwendet: Einerseits wurde bei 16 Wohnungen eine Messkampagne durchgeführt, wobei jeweils Eco-Armaturen am Waschtisch im Bad und am Spültisch in der Küche installiert und der Wasserverbrauch sowie die Wassertemperaturen während eines Jahres gemessen wurden. Andererseits wurden die 16 Haushalte zu den Themen Zufriedenheit, Nutzung und Komfort befragt

Warmwasser-Kurzentnahmen : Auswirkung und Vermeidung

SchlussberichtDiese Feldstudie untersuchte, wie gross die tatsächliche Wirkung von der Funktion «Mittelstellung kalt» auf den Energieverbrauch in Gebäuden ist und wie die Akzeptanz der Nutzer ist. Dafür wurden zwei verschiedene methodische Ansätze verwendet: Einerseits wurde bei 16 Wohnungen eine Messkampagne durchgeführt, wobei jeweils Eco-Armaturen am Waschtisch im Bad und am Spültisch in der Küche installiert und der Wasserverbrauch sowie die Wassertemperaturen während eines Jahres gemessen wurden. Andererseits wurden die 16 Haushalte zu den Themen Zufriedenheit, Nutzung und Komfort befragt

Sun/Shade Separation in Optical and Thermal UAV Images for Assessing the Impact of Agricultural Practices

International audienceUnmanned aerial vehicles (UAVs) provide images at decametric spatial resolutions. Theirflexibility, efficiency, and low cost make it possible to apply UAV remote sensing to multisensordata acquisition. In this frame, the present study aims at employing RGB UAV images (at a 3 cmresolution) and multispectral images (at a 16 cm resolution) with related vegetation indices (VIs) for mapping surfaces according to their illumination. The aim is to map land cover in order to access temperature distribution and compare NDVI and MTVI2 dynamics as a function of their illuminance. The method, which is based on a linear discriminant analysis, is validated at different periods during the phenological cycle of the crops in place. A model based on a given date is evaluated, as well as the use of a generic model. The method provides a good capacity of separation between four classes:vegetation, no-vegetation, shade, and sun (average kappa of 0.93). The effects of agricultural practices on two adjacent plots of maize respectively submitted to conventional and conservation farming are assessed. The transition from shade to sun increases the brightness temperature by 2.4 ◦C and reduces the NDVI by 26% for non-vegetated surfaces. The conservation farming plot is found to be 1.9 ◦C warmer on the 11th of July 2019, with no significant difference between vegetation in the sun or shade. The results also indicate that the NDVI of non-vegetated areas is increased by the presence of crop residues on the conservation agriculture plot and by the effect of shade on the conventional plot which is different for MTVI2

Scedosporiosis/lomentosporiosis observational study (SOS): Clinical significance of Scedosporium species identification

International audienceScedosporiosis/lomentosporiosis is a devastating emerging fungal infection. Our objective was to describe the clinical pattern and to analyze whether taxonomic grouping of the species involved was supported by differences in terms of clinical presentations or outcomes. We retrospectively studied cases of invasive scedosporiosis in France from 2005 through 2017 based on isolates characterized by polyphasic approach. We recorded 90 cases, mainly related to Scedosporium apiospermum (n = 48), S. boydii/S. ellipsoideum (n = 20), and Lomentospora prolificans (n = 14). One-third of infections were disseminated, with unexpectedly high rates of cerebral (41%) and cardiovascular (31%) involvement. In light of recent Scedosporium taxonomic revisions, we aimed to study the clinical significance of Scedosporium species identification and report for the first time contrasting clinical presentations between infections caused S. apiospermum, which were associated with malignancies and cutaneous involvement in disseminated infections, and infections caused by S. boydii, which were associated with solid organ transplantation, cerebral infections, fungemia, and early death. The clinical presentation of L. prolificans also differed from that of other species, involving more neutropenic patients, breakthrough infections, fungemia, and disseminated infections. Neutropenia, dissemination, and lack of antifungal prescription were all associated with 3-month mortality. Our data support the distinction between S. apiospermum and S. boydii and between L. prolificans and Scedosporium sp. Our results also underline the importance of the workup to assess dissemination, including cardiovascular system and brain. Lay Summary Scedosporiosis/lomentosporiosis is a devastating emerging fungal infection. Our objective was to describe the clinical pattern and to analyze whether taxonomic grouping of the species involved was supported by differences in terms of clinical presentations or outcomes

SEIS: Insight’s Seismic Experiment for Internal Structure of Mars

By the end of 2018, 42 years after the landing of the two Viking seismometers on Mars, InSight will deploy onto Mars’ surface the SEIS (Seismic Experiment for Internal Structure) instrument; a six-axes seismometer equipped with both a long-period three-axes Very Broad Band (VBB) instrument and a three-axes short-period (SP) instrument. These six sensors will cover a broad range of the seismic bandwidth, from 0.01 Hz to 50 Hz, with possible extension to longer periods. Data will be transmitted in the form of three continuous VBB components at 2 sample per second (sps), an estimation of the short period energy content from the SP at 1 sps and a continuous compound VBB/SP vertical axis at 10 sps. The continuous streams will be augmented by requested event data with sample rates from 20 to 100 sps. SEIS will improve upon the existing resolution of Viking’s Mars seismic monitoring by a factor of ∼2500 at 1 Hz and ∼200000 at 0.1 Hz. An additional major improvement is that, contrary to Viking, the seismometers will be deployed via a robotic arm directly onto Mars’ surface and will be protected against temperature and wind by highly efficient thermal and wind shielding. Based on existing knowledge of Mars, it is reasonable to infer a moment magnitude detection threshold of ∼3 at 40∘ epicentral distance and a potential to detect several tens of quakes and about five impacts per year. In this paper, we first describe the science goals of the experiment and the rationale used to define its requirements. We then provide a detailed description of the hardware, from the sensors to the deployment system and associated performance, including transfer functions of the seismic sensors and temperature sensors. We conclude by describing the experiment ground segment, including data processing services, outreach and education networks and provide a description of the format to be used for future data distribution