Elastic and fracture properties of free-standing amorphous ALD Al2O3 thin films measured with bulge test

We have investigated elastic and fracture properties of amorphous Al2O3 thin films deposited by atomic layer deposition (ALD) with bulge test technique using a free-standing thin film membrane and extended applicability of bulge test technique. Elastic modulus was determined to be 115 GPa for a 50 nm thick film and 170 GPa for a 15 nm thick film. Residual stress was 142 MPa in the 50 nm Al2O3 film while it was 116 MPa in the 15 nm Al2O3 film. Density was 3.11 g cm(-3) for the 50 nm film and 3.28 g cm(-3) for the 15 nm film. Fracture strength at 100 hPa s(-1) pressure ramp rate was 1.72 GPa for the 50 nm film while for the 15 nm film it was 4.21 GPa, almost 2.5-fold. Fracture strength was observed to be positively strain-rate dependent. Weibull moduli of these films were very high being around 50. The effective volume of a circular film in bulge test was determined from a FEM model enabling future comparison of fracture strength data between different techniques.Peer reviewe

Optical sensor for journal bearing oil film pressure measurements

The oil film pressure is one of the fundamental parameters influencing the operation of journal bearings. The oil film pressure is estimated by theoretical calculations, since the measurement of oil film pressure has been a demanding task in journal bearings, especially in bearings carrying dynamic loads. In this study a new approach to experimentally measure the oil film pressure has been developed and tested. The sensor design utilizes the optical fibre technique and the sensor is integrated in the sliding surface of the bearing thus providing the possibility to measure the actual oil film pressure under load without disturbing the contact conditions. The finite element method (FEM) calculations have been used for optimizing the design of the sensor and for ensuring the appropriate mechanical performance of the sensor design. The optical sensor was integrated into a hydrodynamic journal bearing made of bronze and a versatile bearing test rig was used for testing the operation of the optical sensor. The tests were carried out using both static and dynamic loading conditions with different loads and speeds. The experimental data was compared with the simulated one. The results showed that the optical sensor was capable to measure the oil film pressure in journal bearing at real operating conditions and the sensitivity of the sensor was good enough to verify the speed and load effects on the oil film pressure. According to this work, it is possible to increase the knowledge of true operating conditions of journal bearings by using the optical sensor for oil film pressure measurement. The knowledge can be utilized in the development work of safer and more efficient machines and engines with journal bearing carrying high and dynamic loads. This optical sensor configuration can be used also in other applications for measurement and control of pressure

Alueelliset resurssivirrat Jyväskylän seudulla

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Polttoaineen hinnannousun yritysvaikutukset

Suomen tulee nykyisen EU-lainsäädännön mukaan vähentää kasvihuonekaasupäästöjään taakanjakosektorilla 39 % vuoteen 2030 mennessä verrattuna vuoteen 2005. Kansallisella tasolla Suomi on sitoutunut vähentämään taakanjakosektorille kuuluvan kotimaan liikenteen päästöjä vähintään 50 % vuoteen 2030 mennessä vuoteen 2005 verrattuna. EU:n yhteistä päästötavoitetta tiukennettiin vuoden 2020 lopulla 40 %:sta 55 %:iin, ja Euroopan komissio esittää heinäkuussa 2021 esitetyssä paketissa Suomelle 50% päästövähennystavoitetta taakanjakosektorilla. Toukokuussa 2021 valmistui liikenne- ja viestintäministeriön (jäljempänä LVM) johdolla valmisteltu valtioneuvoston periaatepäätös Fossiilittoman liikenteen tiekartasta. Päätöksessä osoitetaan keinot kotimaan tieliikenteen kasvihuonekaasupäästöjen puolittamiseksi vuoteen 2030 mennessä (verrattuna vuoden 2005 tasoon) sekä päästöjen poistamiseksi vuoteen 2045 mennessä. Tiekartan valmistelun tueksi on aiemmin tutkittu tieliikenteen polttoaineiden mahdollisen hinnannousun vaikutuksia kotitalouksiin sekä dieselin verotuen mahdollisen poistamisen kokonaistaloudellisia vaikutuksia. Tämän työn tavoitteena on ollut selvittää tieliikenteen polttoaineiden mahdollisen hinnannousun vaikutuksia Suomessa eri toimialoilla toimivien yritysten kustannuksiin ja kustannuskilpailukykyyn

IN VITRO INHIBITORY ACTIVITIES OF THE EXTRACT OF HIBISCUS SABDARIFFA L. (FAMILY MALVACEAE) ON SELECTED CYTOCHROME P450 ISOFORMS.

Literature is scanty on the interaction potential of Hibiscus sabdariffa L., plant extract with other drugs and the affected targets. This study was conducted to investigate the cytochrome P450 (CYP) isoforms that are inhibited by the extract of Hibiscus sabdariffa L. in vitro. The inhibition towards the major drug metabolizing CYP isoforms by the plant extract were estimated in human liver microsomal incubations, by monitoring the CYP-specific model reactions through previously validated N-in-one assay method. The ethanolic extract of Hibiscus sabdariffa showed inhibitory activities against nine selected CYP isoforms: CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1 and CYP3A4. The concentrations of the extract which produced 50% inhibition of the CYP isoforms ranged from 306 µg/ml to 1660 µg/ml, and the degree of inhibition based on the IC50 values for each CYP isoform was in the following order: CYP1A2 > CYP2C8 > CYP2D6 > CYP2B6 > CYP2E1 > CYP2C19 > CYP3A4 >> CYP2C9 >> CYP2A6. Ethanolic extract of Hibiscus sabdariffa caused inhibition of CYP isoforms in vitro. These observed inhibitions may not cause clinically significant herb-drug interactions; however, caution may need to be taken in co-administering the water extract of Hibiscus sabdariffa with other drugs until clinical studies are available to further clarify these findings

Carboxymethyl Cellulose (CMC) Optical Fibers for Environment Sensing and Short-Range Optical Signal Transmission

Optical fibers are a key component in modern photonics, where conventionally used polymer materials are derived from fossil-based resources, causing heavy greenhouse emissions and raising sustainability concerns. As a potential alternative, fibers derived from cellulose-based materials offer renewability, biocompatibility, and biodegradability. In the present work, we studied the potential of carboxymethyl cellulose (CMC) to prepare optical fibers with a core-only architecture. Wet-spun CMC hydrogel filaments were cross-linked using aluminum ions to fabricate optical fibers. The transmission spectra of fibers suggest that the light transmission window for cladding-free CMC fibers was in the range of 550–1350 nm, wherein the attenuation coefficient for CMC fibers was measured to be 1.6 dB·cm–1 at 637 nm. CMC optical fibers were successfully applied in touch sensing and respiratory rate monitoring. Finally, as a proof-of-concept, we demonstrate high-speed (150 Mbit/s) short-distance signal transmission using CMC fibers (at 1310 nm) in both air and water media. Our results establish the potential of carboxymethyl cellulose-based biocompatible optical fibers for highly demanding advanced sensor applications, such as in the biomedical domain.publishedVersionPeer reviewe

Accelerated Engineering of ELP-based Materials through Hybrid Biomimetic-De Novo Predictive Molecular Design

Efforts to engineer high-performance protein-based materials inspired by nature have mostly focused on altering naturally occurring sequences to confer the desired functionalities, whereas de novo design lags significantly behind and calls for unconventional innovative approaches. Here, using partially disordered elastin-like polypeptides (ELPs) as initial building blocks this work shows that de novo engineering of protein materials can be accelerated through hybrid biomimetic design, which this work achieves by integrating computational modeling, deep neural network, and recombinant DNA technology. This generalizable approach involves incorporating a series of de novo-designed sequences with α-helical conformation and genetically encoding them into biologically inspired intrinsically disordered repeating motifs. The new ELP variants maintain structural conformation and showed tunable supramolecular self-assembly out of thermal equilibrium with phase behavior in vitro. This work illustrates the effective translation of the predicted molecular designs in structural and functional materials. The proposed methodology can be applied to a broad range of partially disordered biomacromolecules and potentially pave the way toward the discovery of novel structural proteins.</p

Cellulose optical fiber for sensing applications

Cellulose materials offer new biodegradable alternatives for fabricating optical fibers for sensing applications. Unlike glass and polymer optical fibers, these environmentally friendly materials have intrinsic properties making them attractive candidates for functional optical fibers. Cellulose fibers are hygroscopic and thus can rapidly take water vapors from the surroundings and dry quickly. Cellulose-based optical fibers can be manufactured from regenerated cellulose or cellulose derivatives which offer a large property space. They can be resistant or soluble in water, and the refracting index of the material can be tuned as needed. In this work, feasibility for sensor applications of three different cellulose optical fibers have been tested: regenerated cellulose for water and humidity sensing, carboxymethyl cellulose for respiratory rate monitoring, and methylcellulose for short-range 150 Mbit/s signal transmission at 1310 nm. Therefore, fast signal transmission can be achieved with short cellulose-based sensor fibers. The work shows the scientific and technical potential of a novel optical material for photonics.acceptedVersionPeer reviewe

Selvitys akkuklusterin tutkimusinfrastruktuureista

Kansallisessa akkustrategiassa 2025 todetaan, että alan julkiset ja yksityiset tutkimus­infrastruktuurit tulisi verkottaa ja tunnistaa näissä olevat puutteet. Kehittämistyön pohjaksi työ- ja elinkeinoministeriö on tilannut teknologian tutkimuskeskus VTT:ltä selvityksen nykyisistä akkuklusterin julkisista ja yksityisistä tutkimusinfrastruktuureista. Selvityksessä kartoitettiin akkuklusterin nykyiset tutkimusinfrastruktuurit. Infrastruktuurit on koottu raportin liitteeksi sisältäen yleisluontoiset ja teknisemmät kuvaukset. Raportti sisältää kuvauksen nykytilasta. Lisäksi tunnistettiin aukkoja ja kehityskohteita. Selvityksen pohjalta esitetään useita toimenpiteitä, joiden avulla varmistetaan hyvät tutkimuksen perusedellytykset akkuklusterilla. Toimenpiteet sisältävät ehdotuksia laitteistoihin, kuten akkujen turvallisuustestaukseen, akkujen mekaaniseen kierrätykseen ja materiaalitutkimuksen analytiikkaan. Lisäksi toimenpiteinä ehdotetaan datan hyödyntämisen parantamista laatimalla pelisäännöt ja toteuttamalla akkuklusterin data-alusta. Lisäksi erilaiset testiympäristöt, kuten laajat sähköajoneuvojen latauksen testiympäristöt tulisi toteuttaa. Kansallisesti on tärkeää yhteistyön lisääminen ja osaamisen kehittäminen. Tutkimusinfrastruktuureja on mahdollista hyödyntää houkuttelemaan kansainvälisiä hankkeita ja invest-in -toimintaa, siksi ehdotetaan akkuklusterin infrastruktuurien verkottamista ja esittelyä kansainvälisille toimijoille