61 research outputs found

    Prelaunch performance evaluation of the cometary experiment MUPUS-TP

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    This paper discusses test results obtained in both laboratory and terrestrial environment conditions for the “Multipurpose Sensors for Surface and Sub-Surface Science” Thermal Probe (MUPUS-TP), which has been developed for the European Space Agency Rosetta cometary rendezvous mission. The probe is intended to provide in situ long-term observations of the thermal evolution of the comet nucleus and will measure a thermal conductivity profile with time in the top 30 cm of the comet nucleus. The basic operating principles of the probe are briefly described, including typical test results gathered in terrestrial snow and soil. The tests in snow provide verification of the probe as a useful tool for monitoring the metamorphism of snow on the Earth. The tests in soil are intended to demonstrate the probe's suitability as an alternative to other methods of energy measurement currently practiced in soil physics research. The tests of the probe in the natural environment of the Earth provide a demonstration of the behavior of the instrument in the presence of complex energy exchange processes before it is used on the comet

    Photoimageable thick-film microwave structures up to 18 GHz

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    The increasing interest in new wireless applications is creating demand for low cost, high performance microwave hybrid circuits. Offering the inherent advantages of thick-film technology such as low manufacturing costs and feasibility for mass production, recent improvements in thick film materials and processing techniques broadens the frequency range where ceramic thick-film circuits can be used and allow current thick-film technology to reach beyond its previous limitations and enter the domain reserved in the past for thin film technology. This paper discusses the advanced thick-film technique called photoimageable thick-film technology that uses photosensitive conductor and dielectric pastes and photoimaging as a method of patterning for manufacturing microwave hybrids operating in the frequency range up to 18 GHz

    Ophthalmologic micro-tools – composite iris retractors

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    Przedstawione w pracy wyniki badań dotyczą kompozytów polimerowo-włoknistych, które służyć maja jako mikronarzędzia okulistyczne – refraktory tęczówkowe. Otrzymano serię materiałów kompozytowych, w których fazą ciągłą stanowiły nanokompozytowe włókna: syntetyczne (PAN) lub naturalne (CA). W osnowę włókien na etapie wytwarzania wprowadzono Nanocząstki modyfikatora którym dla włókien PAN były nanorurki węglowe (CNT) a dla włókien biopolimerowych CA były nanocząsteczki krzemionki. Do wytworzenia elastycznych mikronarzędzi na bazie włókien nanokompozytowych zastosowano osnowę z żywicy epoksydowej (E 57). Sprawdzono ich właściwości fizykochemiczne, a także użytkowe w porównaniu z dostępnym produktem handlowym. Celem nadania kompozytom odpowiedniej gładkości i podwyższenia ich biozgodności narzędzia pokryto warstwą bioz-godnego polimeru (PCL). Przeprowadzono ocenę mikroskopową powierzchni kompozytów (mikroskop stereoskopowy, mikroskop optyczny), zbadano ich parametry fizyczne (długość, średnica, kąt zakrzywienia) a także stabilność wytworzonych materiałów (1m-sc/370C/H2O). W końcowej części eksperymentu przeprowadzono badania poręczności retraktorów zakładając je na gałki oczne świni (badania in vitro).Results of investigations presented in the work concern polymer-fibrous composites which can be used as ophthalmologic micro-tools – iris retractors. A series of composite materials was produced in which a continuous phase consisted of synthetic (PAN) or natural (CA) nanocomposite fibres. The fibres matrix was modified with filler nanoparticles such as carbon nanotubes (CNT) for PAN and silica for biopolymer fibres CA respectively. The matrix of elastic micro-tools based on the nanocomposite fibres consisted of epoxy resin (E 57). Their physicochemical properties and usability were compared with commercially available products. In order to provide proper smoothness of the composites surface and to increase their biocompatibility the micro-tools were covered with a layer of bio-compatible polymer (PCL). Surface of the micro-tools was observed and evaluated using an optical micro-scope and a stereoscope. Their physical parameters such as length, diameter and inflection angle, and stability in in vitro conditions (1 mth/37oC/H2O) were determined. The last part of experiments consisted of studies of practical application of the micro-tools in rabbit’s eye balls (in vitro studies)

    Application of GPS technology for control points position determination used for the ring road of Wyszków City

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    W pracy przedstawiono metodykę pomiaru i opracowania obserwacji GPS dla zastosowań inżynierskich przy budowie autostrad. Pomiar osnowy realizacyjnej na odcinku 13 km dla obwodnicy Wyszkowa wykonano przy użyciu 7 odbiorników GPS: Ashtech Z-XII, Z-Surveyor oraz Z-Xtreme. Punkty osnowy realizacyjnej były w większości stabilizowane na skraju lasu, co znacznie utrudnia wiarygodne wyznaczenie precyzyjnych współrzędnych. W takich przypadkach niezwykle ważne jest określenie właściwej metodyki pomiaru i opracowanie obserwacji GPS w celu uzyskania wysokiej i wiarygodnej dokładności wyznaczanych pozycji. Przedstawiona metodyka pomiaru oraz opracowania obserwacji GPS umożliwiła otrzymanie dokładności po wyrównaniu rzędu 2–3 mm przy 1.5–3 h sesjach obserwacyjnych.The paper presents methods of measurements and post-processing of GPS observations for engineering applications used for construction of highways. The measurements of geodetic control points on the distance of 13 km of the ring road of Wyszkow were done with the use of seven GPS receivers as Ashtech Z-XII, Ashtech Z-Surveyor and Ashtech Z-Xtreme. The control points of network were situated close to wooden area what makes more difficult accurate coordinates determination. In such situation it is extremely important to choose a proper methodology of GPS measurements and post-processing strategy in order to obtain high and reliable accuracy. The methodology of measurement and post-processing of GPS data presented in this paper allowed to obtain 2-3 mm accuracy after network adjustment having 1.5 – 3 hours GPS sessions

    <i>In Situ</i> Transmission Electron Microscopy Study of Electrochemical Lithiation and Delithiation Cycling of the Conversion Anode RuO<sub>2</sub>

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    Conversion-type electrodes represent a broad class of materials with a new Li<sup>+</sup> reactivity concept. Of these materials, RuO<sub>2</sub> can be considered a model material due to its metallic-like conductivity and its high theoretical capacity of 806 mAh/g. In this paper, we use <i>in situ</i> transmission electron microscopy to study the reaction between single-crystal RuO<sub>2</sub> nanowires and Li<sup>+</sup>. We show that a large volume expansion of 95% occurs after lithiation, 26% of which is irreversible after delithiation. Significant surface roughening and lithium embrittlement are also present. Furthermore, we show that the initial reaction from crystalline RuO<sub>2</sub> to the fully lithiated mixed phase of Ru/Li<sub>2</sub>O is not fully reversible, passing through an intermediate phase of Li<sub><i>x</i></sub>RuO<sub>2</sub>. In subsequent cycles, the phase transitions are between amorphous RuO<sub>2</sub> in the delithiated state and a nanostructured network of Ru/Li<sub>2</sub>O in the fully lithiated phase

    <i>In Situ</i> Transmission Electron Microscopy Study of Electrochemical Lithiation and Delithiation Cycling of the Conversion Anode RuO<sub>2</sub>

    No full text
    Conversion-type electrodes represent a broad class of materials with a new Li<sup>+</sup> reactivity concept. Of these materials, RuO<sub>2</sub> can be considered a model material due to its metallic-like conductivity and its high theoretical capacity of 806 mAh/g. In this paper, we use <i>in situ</i> transmission electron microscopy to study the reaction between single-crystal RuO<sub>2</sub> nanowires and Li<sup>+</sup>. We show that a large volume expansion of 95% occurs after lithiation, 26% of which is irreversible after delithiation. Significant surface roughening and lithium embrittlement are also present. Furthermore, we show that the initial reaction from crystalline RuO<sub>2</sub> to the fully lithiated mixed phase of Ru/Li<sub>2</sub>O is not fully reversible, passing through an intermediate phase of Li<sub><i>x</i></sub>RuO<sub>2</sub>. In subsequent cycles, the phase transitions are between amorphous RuO<sub>2</sub> in the delithiated state and a nanostructured network of Ru/Li<sub>2</sub>O in the fully lithiated phase

    <i>In Situ</i> Transmission Electron Microscopy Study of Electrochemical Lithiation and Delithiation Cycling of the Conversion Anode RuO<sub>2</sub>

    No full text
    Conversion-type electrodes represent a broad class of materials with a new Li<sup>+</sup> reactivity concept. Of these materials, RuO<sub>2</sub> can be considered a model material due to its metallic-like conductivity and its high theoretical capacity of 806 mAh/g. In this paper, we use <i>in situ</i> transmission electron microscopy to study the reaction between single-crystal RuO<sub>2</sub> nanowires and Li<sup>+</sup>. We show that a large volume expansion of 95% occurs after lithiation, 26% of which is irreversible after delithiation. Significant surface roughening and lithium embrittlement are also present. Furthermore, we show that the initial reaction from crystalline RuO<sub>2</sub> to the fully lithiated mixed phase of Ru/Li<sub>2</sub>O is not fully reversible, passing through an intermediate phase of Li<sub><i>x</i></sub>RuO<sub>2</sub>. In subsequent cycles, the phase transitions are between amorphous RuO<sub>2</sub> in the delithiated state and a nanostructured network of Ru/Li<sub>2</sub>O in the fully lithiated phase
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