The development of a highperformance perfluorinated polymer electret and its application to micro power generation

Abstract Recently, micro power generation using electrets has attracted much attention due to its large power output at a low frequency range. Since the theoretical power output is proportional to the square of the surface charge density of the electret, the development of a high-performance electret is required. In the present study, it is shown that the surface charge density of a CYTOP electret is significantly improved by the addition of terminal groups. Based on this fact, a novel high-performance polymer electret has been developed by doping a silane-coupling reagent into the polymer. A series of measurements of surface potential and TSD (thermally stimulated discharge) spectra was made for various CYTOP films prepared with different silane-coupling reagent concentrations. It is found that the surface charge density, charge stability and thermal resistibility of electric charges are markedly improved by the doping. A surface charge density of 1.5 mC cm −2 , which is three times larger than that of Teflon AF, has been obtained on a 15 μm thick film. In addition, the thermal stability of the CYTOP electret is superior to that of Teflon AF. Power generation experiment is also performed using the patterned CYTOP electret of 20 × 20 mm 2 . At a low seismic frequency of 20 Hz, 0.7 mW power generation has been accomplished, which is about 2.5 times higher than our previous result

FUELCELL2008-65079 EFFECTS OF ELECTRODE MICROSTRUCTURE ON POLARIZATION CHARACTERISTICS OF SOFC ANODES

ABSTRACT Anode microstructure parameters were quantified by SEM-EDX measurements and the dependence of polarization characteristics on the anode microstructure parameters is investigated experimentally. Nickel yttria-stabilized zirconia (Ni-YSZ) anode supported cells with a thin YSZ electrolyte, lanthanum-strontium-manganite(LSM)-YSZ composite cathode, and LSM cathode current collector layers were fabricated by dip coating method. Anode microstructure was successfully imaged and quantified by ultra low voltage SEM and by means of stereology. Cell voltage measurements and impedance spectroscopy were performed at 650 and 750˚C with hydrogen diluted by nitrogen as a fuel. A quantitative relationship between measured polarization and microstructure parameters, e.g., three phase boundary length, contiguity, etc., was discussed. Finally, a cell with an anode functional layer (AFL) was fabricated to investigate the possibility of improving both activation and concentration polarization characteristics

Taloyhtiön pihasaneeraus : Esimerkkikohteena As Oy Kananlaulu

Työn taustana käytettiin lähiöiden suurimman aikakauden, 1960- ja 1970-lukujen kerrostalojen ajankohtaista peruskorjaustarvetta. Peruskorjaustarve koskee niin kiinteistön piha-aluetta kuin kiinteistön muitakin osia. Pihojen suurin korjaustarve perustuu kuluneiden kalusteiden, varusteiden, kasvillisuuden ja muiden osien huonokuntoisuuteen. Lisäksi muuttuneet turvallisuusvaatimukset sekä esteettömyyden haasteet tuovat lisätarvetta pihojen saneerauksille. Työni tavoitteena oli lisätä viihtyisyyttä ja parantaa Asunto Oy Kananlaulun piha-aluetta sen saneerauksella. Saneerauksessa huomioidaan metsälähiön tyypilliset pihasuunnittelun erityispiirteet. Piha-alueen analyysin avulla arvioitiin sen nykytilaa paikan päällä kohteessa. Samalla tutustuttiin myös suunnitelma- ja urakka-asiakirjoihin. Työn pohjana tutkittiin kerrostalorakentamisen ja niiden piha-aluerakentamisen kehitystä Suomessa. Tietopohjaksi haettiin tietoa myös kerrostalopihojen kunnostuksesta ja kunnostusprosessista. Tuloksena oli kirjallinen selostus piharakentamisen vaiheista. Työni toimeksiantajana oli VRJ Pohjois-Suomi Oy. Työn tulokset ovat hyödynnettävissä kerrostalopihojen peruskorjaushankkeissa. Asunto Oy Kananlaulun piha-analyysi ja pihasaneeraus voidaan liittää osaksi Kaukovainion kehittämistä. Työn tulokset antavat myös minulle itselleni mahdollisuuden kehittää omaa osaamistani viherrakentamisen työnjohdossa.As a background for the work was used the topical need of renovation in the block of flats in the suburbs built in the 1960- and 1970´s. The renovation need applies both to the yard and the other parts of the property. The biggest need of renovation is based on the poor condition of the worn out equipment, vegetation and other parts of the yard. Furthermore the changed requirements of safety and accessibility increase the renovation need. The goal on my work was to add the comfort and attractiveness of the yard of Asunto Oy Kananlaulu. During the renovation the typical characteristics of a wooden suburb were taken into account. The present situation of the yard was estimated on site. At the same time I familiarized myself the documents of planning and subcontracting. For the background of the work the development of the building of the block of flats and their yards was investigated. Also the renovation of yards and the process of renovation was studied. The result of the work is a written report of the stages of the yard construction. The principal of the work was VRJ Pohjois-Suomi Oy. The results of the work can be utilized in high-rise yards’ renovation projects. The analyses and renovation of the yard can be linked to the development of Kaukovainio area. The results of the work gave me the possibility to develop my own skills on supervision of work at green construction

MICRO MAGNETIC CELL SORTING SYSTEM WITH A FUNCTION OF CONTINUOUS LABELING AND SEPARATION

ABSTRACT We report development of a novel micro magnetic cell sorting system for the precise extraction of stem cells from a small amount of concentrated sample. The system consists of a lamination mixer for labeling target cells with magnetic beads, and a magnetic separator with an embedded coil, where continuous cell separation is accomplished. We fabricated a prototype device using soft lithography, and evaluated the separation performance. We successfully achieved the continuous labeling and separation of target cells. The results show that the number of binding magnetic bead for each cell ranges widely from several to dozens

Effects of spatially varying slip length on friction drag reduction in wall turbulence

A series of direct numerical simulation has been made of turbulent flow over hydrophobic surfaces, which are characterized by streamwise periodic micro-grooves. By assuming that the size of micro-grooves is much smaller than the typical length-scale of nearwall turbulent structures, the dynamical boundary condition is expressed by a mobility tensor, which relates the slip velocity and the surface shear stress. Based on the derived mathematical relationship between the friction drag and different dynamical contributions, it is shown how the turbulence contribution can be extracted and analyzed