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Comprehensive lignin balance and new insights into softwood lignosulphonates from neutral sulphite pulping
No full textAccurate material balance of lignosulphonates in sulphite pulping and biorefinery processes is essential for their efficient recovery and utilization. By measuring the absorbances of dissolved lignosulphonates from pulp and spent liquor as lignin phenylpropane units at 280 nm by UV spectroscopy, the challenges caused by varying sulphonic acid group content in the dissolved fractions can be mitigated, ensuring a more accurate balance. This method was validated by compiling comprehensive lignin balances for six softwood neutral sulphite pulps, with yield levels ranging from 84.0 % to 57.7 %. The total lignin balances included lignosulphonates from the spent liquors and those isolated from the pulps by alkaline extraction and enzymatic hydrolysis, representing the distribution of wood lignin across the isolated fractions based on the degree of delignification and lignin alteration. Analyses of dissolved fractions, accounting for 74–95 % of the wood lignin, provided insight into softwood lignin sulphonation and fragmentation during neutral sulphite pulping. The spent liquor lignosulphonates had sulphonic acid group contents of 1.02–1.29 mmol/g and the average molecular weights between 5 200 and 13 400 g/mol, consistent with values reported in literature for hardwood lignosulphonates from NSSC pulping. Lignosulphonates isolated by alkaline extraction exhibited characteristics similar to those of spent liquor lignosulphonates, whereas those isolated by enzymatic hydrolysis were less sulphonated, had a higher average molecular weight, and appeared to be closer to the native type of lignin.</p
Moulding prepreg platelets into high fibre loading fraction carbon fibre-reinforced syntactic epoxy foams
No full textThis study presents a novel method for manufacturing high fibre content carbon fibre-reinforced syntactic epoxy foams by moulding prepreg platelets with hollow glass microspheres. The prepreg platelets were either (i) dry-mixed at room temperature or (ii) mixed at cryogenic temperature in liquid nitrogen with hollow glass microspheres prior to compression moulding. This approach achieves a carbon fibre volume fraction of up to 49 %, addressing the limitations of low fibre content in conventional syntactic foams. The resulting materials exhibit enhanced mechanical properties, including a compressive modulus of ∼6 GPa and ∼3.5 GPa in the in-plane and through-thickness directions, respectively. The anisotropy in mechanical properties is attributed to the anisotropic packing of the prepreg platelets. Packing simulations using PyBullet confirmed that microspheres did not disrupt platelet arrangement, maintaining a packing efficiency of ∼63 % while filling inter-platelet gaps. Although cryogenic processing improved the mixing process, its impact on mechanical performance was minimal. This study demonstrates a simple manufacturing approach to produce high performance carbon fibre reinforced porous polymer composites suitable for lightweighting applications.</p
Oral microbiome dysbiosis in cryptogenic ischemic stroke patients with high-risk patent foramen ovale
No full textPatent foramen ovale (PFO) is the most common congenital heart abnormality of foetal origin and has been associated with cryptogenic ischemic stroke (CIS) through several mechanisms, with most theories supporting paradoxical embolism. Other possible but unknown contributing factors, such as the role of the microbiome in PFO-associated strokes, remain unclear. We analysed saliva metagenomes to study the differences in the oral microbiome between young-onset CIS patients with clinically relevant high-risk PFO (n = 52) and those without PFO (n = 52). Age- and sex-matched stroke-free controls (n = 16) with high-risk PFO were included for the comparison. Beta diversity was significantly different between patients and controls with high-risk PFO, but not between patients with and without high-risk PFO. The phylum Ascomycota and class Saccharomycetes were significantly more abundant in patients with high-risk PFO than in those without high-risk PFO. Additionally, the abundance of Lactococcus, including Lactococcus raffinolactis and L. cremoris, was higher in controls with high-risk PFO than in patients with high-risk PFO. These findings highlight that oral dysbiosis and high-risk PFO may form a critical but under-recognized combination in the aetiology of CIS. Future research should focus on elucidating the precise mechanisms of these interactions and developing targeted interventions.</p
What drives change? Dynamic institutionalizations of responsible research and innovation in organizations:reflections on the role of institutional entrepreneurship
No full textWhile most innovations are developed in organizations, there is a wide-spread consensus that the organizational institutionalization of Responsible (Research and) Innovation is limited. This may partly be the case because we lack an understanding of what factors drive or impede the institutionalization of such responsibility-related changes and how they interact. In this paper, we draw from various institutional entrepreneurs’ experiences, who worked within eight organizational change labs, to explore the dynamic institutionalization of Responsible (Research and) Innovation. Our study identifies 29 factors highlighting some of the intricate, dynamic, and ‘messy’ complexities found in organizations. We conclude by offering some reflections on the role of institutional entrepreneurship for Responsible (Research and) Innovation.</p
Fracture toughness behavior of high-Ni/high-Mn Barsebäck 2 reactor pressure vessel welds after 28 years of operation
Get PDFThe safety assessment of reactor pressure vessels (RPV) is based on knowledge obtained from surveillance programs. In this study, the fracture toughness characteristics in the ductile-to-brittle transition region were determined for samples extracted from Barsebäck 2 RPV’s beltline and head high Ni/Mn welds, and the results were compared to the surveillance welds. The fracture toughness results from the surveillance program describe the RPV core welds after 28 years of operation associated to a fluence of 0.1·1019n/cm2 in the beltline region. The results show that the microstructural features of the multilayer weld increase the uncertainty in the reference temperature T0 to 34 °C. The inhomogeneity of the weld affects more the fracture toughness properties in comparison to impact toughness. The T0 based embrittlement trend curve obtained for Barsebäck 2 weld subjected to a maximum fluence of 5.9·1019n/cm2 is compared to similar welds. The results contribute to improvements in reliability of aging management programs of nuclear power plants important for availability of carbon free energy
How do IoT solutions enable circular economy business models?
Get PDFThe transition from linear economy to circular economy (CE) business models represents a paradigm shift towards sustainability, including resource and material efficiency, reduced negative environmental impacts and minimised leakages from a circular system. The current twin transition refers to green transition (sustainability) and digital transition (digitalisation). In the manufacturing industry, the Internet of Things (IoT) emerges as a catalyst in this transformation, offering connectivity and real-time data and enabling improved monitoring, optimisation and management of operations. Utilisation of IoT promotes implementation of circularity actions, that is, optimises resource use, extends product lifecycles and facilitates recovery and reuse of materials. This paper explores the relation between IoT and CE business models and addresses IoT’s role in enabling them. The topic is limited to the manufacturing context, excluding the business models associated with the use phase but including the earlier lifecycle phases of a product, as well as possible remanufacturing steps. The area of study is tackled by reviewing the relevant literature and mapping the connections and possibilities compatible with IoT solutions and CE business models. This research also considers practical benefits from a circularity and sustainability perspective. Based on the findings, the paper concludes that IoT technologies support different CE actions and help implement them in a smart manufacturing ecosystem. IoT solutions enable certain CE business models, especially related to material control and efficiency, while improving the overall transparency and sustainability of the value chain processes
LPMO-Catalyzed Oxidation of Cellulosic Fibers with Controlled Addition of a Reductant and H<sub>2</sub>O<sub>2</sub>
No full textCellulose-derived biomaterials offer a sustainable and versatile platform for various applications. Enzymatic engineering of these fibers, particularly using lytic polysaccharide monooxygenases (LPMOs), shows promise due to the ability to introduce functional groups onto cellulose surfaces, potentially enabling further functionalization. However, harnessing LPMOs for fiber engineering remains challenging, partly because controlling the enzymatic reaction is difficult and partly because limited information is available about how LPMOs modify the fibers. In this study, we explored controlling LPMO-mediated fiber oxidation by sequentially adding a reductant (gallic acid, GA) and H2O2, using three different carbohydrate-binding module (CBM)-containing LPMOs. An in-depth analysis of the soluble products and the Mn, Mw, and carbonyl content in the fiber fraction indicates that fiber oxidation can indeed be controlled by adjusting the amount of GA and H2O2 added to the reaction. In particular, at lower overall dosages of GA and H2O2, corresponding to low oxidation levels, fiber oxidation occurs rapidly with almost no release of soluble oxidized products. Conversely, at higher dosages, fiber oxidation levels off, while oxidized oligosaccharides continue to be released and the fibers are eroded. Importantly, next to demonstrating controlled fiber oxidation, this study shows that different cellulose-active LPMOs modify the fibers in different manners.</p
Effect of energetic ions on edge-localized modes in tokamak plasmas
No full textThe most efficient and promising operational regime for the International Thermonuclear Experimental Reactor tokamak is the high-confinement mode. In this regime, however, periodic relaxations of the plasma edge can occur. These edge-localized modes pose a threat to the integrity of the fusion device. Here we reveal the strong impact of energetic ions on the spatio-temporal structure of edge-localized modes in tokamaks using nonlinear hybrid kinetic–magnetohydrodynamic simulations. A resonant interaction between the fast ions at the plasma edge and the electromagnetic perturbations from the edge-localized mode leads to an energy and momentum exchange. Energetic ions modify, for example, the amplitude, frequency spectrum and crash timing of edge-localized modes. The simulations reproduce some observations that feature abrupt and large edge-localized mode crashes. The results indicate that, in the International Thermonuclear Experimental Reactor, a strong interaction between the fusion-born alpha particles and ions from neutral beam injection, a main heating and fast particle source, is expected with predicted edge-localized mode perturbations. This work advances the understanding of the physics underlying edge-localized mode crashes in the presence of energetic particles and highlights the importance of including energetic ion kinetic effects in the optimization of edge-localized mode control techniques and regimes that are free of such modes.</p
Nonlinear excitation of energetic particle driven geodesic acoustic mode by resonance overlap with Alfvén instability in ASDEX Upgrade
No full textThe Alfvén instability nonlinearly excited the energetic-particle-driven geodesic acoustic mode on the ASDEX-Upgrade tokamak, as demonstrated experimentally. The mechanism of the energetic-particle-driven geodesic acoustic mode excitation and the mode nonlinear evolution is not yet fully understood. In the present work, a first-principles simulation using the MEGA code investigated the mode properties in both the linear growth and nonlinear saturated phases. Here we show that the simulation successfully reproduced the excitation and coexistence of these two modes, and agreed with the experimental results well. Conclusive evidence showed that the resonance overlap is the excitation mechanism of the energetic-particle-driven geodesic acoustic mode. In the linear growth phase, energetic particles that satisfied different resonance conditions excited the Alfvén instability, which then caused energetic particle redistribution in phase space. These redistributed energetic particles caused resonance overlap, exciting the energetic-particle-driven geodesic acoustic mode in the nonlinear phase.</p
Kvanttilaskenta: Käytännön matkaopas tulevaisuuteen
No full textOppaan tarkoitus on saada sinut pohtimaan, mikä merkitys kvanttilaskennalla voisi olla yrityksellesi ja miten organisaatiosi kannattaisi valmistautua kvanttiaikaan. Se tarjoaa käytännönläheisen katsauksen kvanttilaskennan mahdollisuuksiin ja haasteisiin liiketoiminnan näkökulmasta. Kvanttifysiikan teorioiden selittämisen sijasta oppaassa keskitytään siihen, miten voit valmistella yritystäsi tulevaisuuteen, jossa kvanttilaskenta on arkipäivää.Lukemalla tämän oppaan saat tietoa siitä, mitkä toimialat kvanttilaskenta todennäköisimmin mullistaa ja mitä kilpailuetuja se voi tarjota. Opas tarjoaa käytännön työkaluja oman toimialasi analysointiin ja strategian suunnitteluun sekä auttaa ymmärtämään kehittyvää teknologiaa. Lisäksi opas auttaa tulkitsemaan kvanttiteknologian kehitystä käsitteleviä media-artikkeleita ja uutisia, joita julkaistaan kiihtyvällä tahdilla. Kirja voi toimia myös kvanttilaskennan sanansaattajana organisaatiossasi.Tämän oppaan pyrkimyksenä on auttaa sinua ymmärtämään kvanttilaskennan narratiivia – toisaalta näkemään liiallisen hehkutuksen läpi ja toisaalta välttämään pessimismin, jota kvanttitietokoneisiin liittyvät haasteet voivat ruokkia. Lukemisen jälkeen pystyt muodostamaan tasapainoisen ja jäsennellyn käsityksen kvanttilaskennan mahdollisuuksista ja haasteista. Se antaa sinulle valmiudet tehdä tietoon perustuvia strategisia päätöksiä nopeasti kehittyvällä alalla