High Alpha - Termisesti ruiskutetut kromioksidi- ja piikarbidiseosteiset alumiinioksidipinnoitteet. Loppuraportti

Tässä raportissa on esitetty yhteenveto termisesti ruiskutettujen alumiinioksidipohjaisten pinnoitejauheiden ja niistä eri termisillä ruiskutusmenetelmillä valmistettujen pinnoitteiden ominaisuuksista. Työ liittyy osana TTY:n Materiaaliopin laitoksella toteutettuun Tekes ‐rahoitteiseen High‐ALPHA ‐projektiin, jossa alumiinioksidipinnoitteiden korroosio‐ ja kulumisominaisuuksia pyrittiin parantamaan faasistabiloinnin avulla

A spatial enhancement approach for binaural rendering of head-worn microphone arrays

This paper builds upon a recently proposed spatial enhancement approach, which has demonstrated im- provements in the perceived spatial accuracy of binaurally rendered signals using head-worn microphone arrays. The foundation of the approach is a parametric sound-field model, which assumes the existence of a single source and an isotropic diffuse component for each time-frequency index. The enhancement approach involves the post-processing of an initial estimate of the binaural signals, in order to obtain a refined esti- mate of binaural signals which more closely represent the inter-aural cues corresponding to the sound-field model. In this contribution, the enhancement approach has been implemented as an open-source framework, written in both the MATLAB and C programming languages, and as a real-time audio plug-in. The frame- work was also extended to offer direction-dependent gain control of sound sources relative to the listener, and a frequency-dependent control of the direct-to-diffuse balance, which are modifications that may find application within future augmented reality headsets and assistive hearing devices.publishedVersionNon peer reviewe

Microbes Bind Complement Inhibitor Factor H via a Common Site

To cause infections microbes need to evade host defense systems, one of these being the evolutionarily old and important arm of innate immunity, the alternative pathway of complement. It can attack all kinds of targets and is tightly controlled in plasma and on host cells by plasma complement regulator factor H (FH). FH binds simultaneously to host cell surface structures such as heparin or glycosaminoglycans via domain 20 and to the main complement opsonin C3b via domain 19. Many pathogenic microbes protect themselves from complement by recruiting host FH. We analyzed how and why different microbes bind FH via domains 19–20 (FH19-20). We used a selection of FH19-20 point mutants to reveal the binding sites of several microbial proteins and whole microbes (Haemophilus influenzae, Bordetella pertussis, Pseudomonas aeruginosa, Streptococcus pneumonia, Candida albicans, Borrelia burgdorferi, and Borrelia hermsii). We show that all studied microbes use the same binding region located on one side of domain 20. Binding of FH to the microbial proteins was inhibited with heparin showing that the common microbial binding site overlaps with the heparin site needed for efficient binding of FH to host cells. Surprisingly, the microbial proteins enhanced binding of FH19-20 to C3b and down-regulation of complement activation. We show that this is caused by formation of a tripartite complex between the microbial protein, FH, and C3b. In this study we reveal that seven microbes representing different phyla utilize a common binding site on the domain 20 of FH for complement evasion. Binding via this site not only mimics the glycosaminoglycans of the host cells, but also enhances function of FH on the microbial surfaces via the novel mechanism of tripartite complex formation. This is a unique example of convergent evolution resulting in enhanced immune evasion of important pathogens viautilization of a “superevasion site.

Eddy-Current Loss Model for Soft Magnetic Composite Materials Considering Particle Size Distribution

Dynamic magnetization curves of soft magnetic materials are often written in terms of magnetic flux density b and magnetic field strength h as h = H(b) + c db/dt , where H is a static magnetization model and c is a real number describing eddy-current effects. In this article, an analytical derivation for c is presented for soft magnetic composite materials. The parameter c will depend explicitly on the conductivity of the material particles as well as the geometry of the particles, described by mean particle volume, variance of the particle volumes, volume fraction of the material and insulation thicknesses. No experimental or empirical parameters appear in c in our treatment.publishedVersionPeer reviewe

High Alpha - Termisesti ruiskutetut kromioksidi- ja piikarbidiseosteiset alumiinioksidipinnoitteet. Loppuraportti

Tässä raportissa on esitetty yhteenveto termisesti ruiskutettujen alumiinioksidipohjaisten pinnoitejauheiden ja niistä eri termisillä ruiskutusmenetelmillä valmistettujen pinnoitteiden ominaisuuksista. Työ liittyy osana TTY:n Materiaaliopin laitoksella toteutettuun Tekes ‐rahoitteiseen High‐ALPHA ‐projektiin, jossa alumiinioksidipinnoitteiden korroosio‐ ja kulumisominaisuuksia pyrittiin parantamaan faasistabiloinnin avulla.publishedVersio

High Alpha - Termisesti ruiskutetut kromioksidi- ja piikarbidiseosteiset alumiinioksidipinnoitteet. Loppuraportti

Tässä raportissa on esitetty yhteenveto termisesti ruiskutettujen alumiinioksidipohjaisten pinnoitejauheiden ja niistä eri termisillä ruiskutusmenetelmillä valmistettujen pinnoitteiden ominaisuuksista. Työ liittyy osana TTY:n Materiaaliopin laitoksella toteutettuun Tekes ‐rahoitteiseen High‐ALPHA ‐projektiin, jossa alumiinioksidipinnoitteiden korroosio‐ ja kulumisominaisuuksia pyrittiin parantamaan faasistabiloinnin avulla.publishedVersio

Enhancing binaural rendering of head-worn microphone arrays through the use of adaptive spatial covariance matching

Publisher Copyright: © 2022 Author(s).In this article, the application of spatial covariance matching is investigated for the task of producing spatially enhanced binaural signals using head-worn microphone arrays. A two-step processing paradigm is followed, whereby an initial estimate of the binaural signals is first produced using one of three suggested binaural rendering approaches. The proposed spatial covariance matching enhancement is then applied to these estimated binaural signals with the intention of producing refined binaural signals that more closely exhibit the correct spatial cues as dictated by the employed sound-field model and associated spatial parameters. It is demonstrated, through objective and subjective evaluations, that the proposed enhancements in the majority of cases produce binaural signals that more closely resemble the spatial characteristics of simulated reference signals when the enhancement is applied to and compared against the three suggested starting binaural rendering approaches. Furthermore, it is shown that the enhancement produces spatially similar output binaural signals when using these three different approaches, thus indicating that the enhancement is general in nature and could, therefore, be employed to enhance the outputs of other similar binaural rendering algorithms.Peer reviewe

Multiphase TixOy nanoparticles by pulsed laser ablation of titanium in supercritical CO2

In this paper, we demonstrate pulsed laser ablation (PLA) in supercritical CO2 (scCO2) as a promising method to synthesize multiphase TixOy nanoparticles from a titanium target. These results are compared against PLA of titanium in H2O. By means of transmission electron microscopy, we observed spherical-shaped, well-dispersed non-agglomerate crystalline nanoparticles by PLA in scCO2 while PLA in H2O produced spherical-shaped as well as randomly shaped nanoparticles that joined to form web-like networks. Raman spectroscopy and x-ray diffraction showed nanoparticles synthesized in scCO2 consisted of anatase-TiO2, Ti2O3 and TiO0.89 while nanoparticles synthesized in H2O were mainly rutile-TiO2, with possibility of presence of brookite-TiO2. This indicates PLA in scCO2 favours formation of metastable phases (anatase-TiO2, Ti2O3 and TiO0.89) while PLA in H2O results in mostly stable phase (rutile-TiO2).acceptedVersionPeer reviewe

Pulsed Laser Ablation-Induced Green Synthesis of TiO2 Nanoparticles and Application of Novel Small Angle X-Ray Scattering Technique for Nanoparticle Size and Size Distribution Analysis

This paper aims to introduce small angle X-ray scattering (SAXS) as a promising technique for measuring size and size distribution of TiO2 nanoparticles. In this manuscript, pulsed laser ablation in liquids (PLAL) has been demonstrated as a quick and simple technique for synthesizing TiO2 nanoparticles directly into deionized water as a suspension from titanium targets. Spherical TiO2 nanoparticles with diameters in the range 4–35 nm were observed with transmission electron microscopy (TEM). X-ray diffraction (XRD) showed highly crystalline nanoparticles that comprised of two main photoactive phases of TiO2: anatase and rutile. However, presence of minor amounts of brookite was also reported. The traditional methods for nanoparticle size and size distribution analysis such as electron microscopy-based methods are time-consuming. In this study, we have proposed and validated SAXS as a promising method for characterization of laser-ablated TiO2 nanoparticles for their size and size distribution by comparing SAXS- and TEM-measured nanoparticle size and size distribution. SAXS- and TEM-measured size distributions closely followed each other for each sample, and size distributions in both showed maxima at the same nanoparticle size. The SAXS-measured nanoparticle diameters were slightly larger than the respective diameters measured by TEM. This was because SAXS measures an agglomerate consisting of several particles as one big particle which slightly increased the mean diameter. TEM- and SAXS-measured mean diameters when plotted together showed similar trend in the variation in the size as the laser power was changed which along with extremely similar size distributions for TEM and SAXS validated the application of SAXS for size distribution measurement of the synthesized TiO2 nanoparticles.publishedVersionPeer reviewe

Manganese-cobalt spinel coatings for SOFC metallic interconnects manufactured by conventional plasma spraying (PS) and suspension plasma spraying (SPS)

Protective coatings are used on ferritic stainless steel interconnects of solid oxide fuel cells (SOFCs) to prevent the oxidation and evaporation of volatile chromium compounds. Oxide scale is formed of chromium oxide (Cr 2O3) which tends to react with the oxygen and water, forming chromium trioxide (C2O3) and chromium hydroxides (Cr2(OH)2). These compounds will migrate to the triple phase barrier (TPB) of a cathode and reduce back to Cr2O3. This reaction pathway is a notable reason for the degradation phenomena of the cell. Plasma spraying (PS) and suspension plasma spraying (SPS) were studied as possible manufacturing processes for thin Mn-Co-(Fe) spinel coatings. Powder for PS was manufactured by using a solid state reaction method from carbonates and oxide to form a MnCo1.8Fe0.2O4 and powder for SPS by co-precipitation process from nitrates to form a MnCo2O 4 spinel structure Using PS, coatings with thin and relatively dense structures were obtained. The composition of the coatings was homogeneous although, the decomposition of the spinel structure was noticed. The crystal structures of the PS coatings were partially restored by a separate annealing process. The spray parameters had a strong influence on the coating structure and the composition when SPS was used. The most homogenous coating structure was formed when low energy spraying parameters were used, whereas high energy parameters formed a columnar structure with larger cobalt rich areas. The decomposed spinel structure of the SPS coatings were fully restored by the annealing treatment. In SPS, more process optimization is needed to improve the coating quality and especially denseness.</p