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Zeaxanthin epoxidase 3 Knockout Mutants of the Model Diatom Phaeodactylum tricornutum Enable Commercial Production of the Bioactive Carotenoid Diatoxanthin
Get PDFCarotenoids are pigments that have a range of functions in human health. The carotenoid diatoxanthin is suggested to have antioxidant, anti-inflammatory and chemo-preventive properties. Diatoxanthin is only produced by a few groups of microalgae, where it functions in photoprotection. Its large-scale production in microalgae is currently not feasible. In fact, rapid conversion into the inactive pigment diadinoxanthin is triggered when cells are removed from a high-intensity light source, which is the case during large-scale harvesting of microalgae biomass. Zeaxanthin epoxidase (ZEP) 2 and/or ZEP3 have been suggested to be responsible for the back-conversion of high-light accumulated diatoxanthin to diadinoxanthin in low-light in diatoms. Using CRISPR/Cas9 gene editing technology, we knocked out the ZEP2 and ZEP3 genes in the marine diatom Phaeodactylum tricornutum to investigate their role in the diadinoxanthin–diatoxanthin cycle and determine if one of the mutant strains could function as a diatoxanthin production line. Light-shift experiments proved that ZEP3 encodes the enzyme converting diatoxanthin to diadinoxanthin in low light. Loss of ZEP3 caused the high-light-accumulated diatoxanthin to be stable for several hours after the cultures had been returned to low light, suggesting that zep3 mutant strains could be suitable as commercial production lines of diatoxanthin.publishedVersio
Testing Two Methods for Earth Fault Location in Closed-Ring Operated Distribution Networks: Lessons Learned From Field Tests
Get PDFTo test two newly developed methods for location of earth faults in closed-ring distribution networks, field tests have been carried out in a ring-operated 22 kV resonant grounded network. The results demonstrate poorer accuracy than expected, so this paper presents analyses of some likely sources of error. First, the impact of inaccurate line data, measurement inaccuracies and phasor estimation issues are described and studied analytically. Examples from the field tests demonstrate that all of these are likely contributors to the results, although some more than others. For one of the methods based on negative sequence currents, the inaccurate measurement of the three phase currents appears to be the most likely single reason for the low accuracy observed. For the method based on zero-sequence quantities, inaccurate line data is assumed to be another key factor. From the analyses, it is concluded that dedicated sensors are needed for accurate negative sequence current acquisition, and this is currently not available in the test network's substations. For line parameter acquisition it is argued that manufacturer data and analytically obtainTesting Two Methods for Earth Fault Location in Closed-Ring Operated Distribution Networks: Lessons Learned From Field TestsacceptedVersio
SMARAGD: Data Interoperability for Decision Support in the Norwegian Agrifood Sector
Get PDFNorwegian land-based food production faces significant challenges driven by evolving weather patterns, rising operational costs, and labour scarcity. In response, there is a pressing need for enhanced strategies rooted in real time field insights. This necessitates the adoption of smart sensor-driven agritech technologies and data-driven precision farming solutions. While these technologies generate vast datasets, their transformative potential is hindered by interoperability gaps at data and API levels, constraining their adoption and utility. To address these limitations, the SMARAGD project focuses on enhancing data interoperability to integrate diverse datasets and leverage the synergistic effects of combined data, while also fostering opportunities for data providers to monetise their contributions. Through a plug-in architecture adhering to industry standards, SMARAGD aims to integrate diverse agritech data sources and services, presenting tailored insights to end users for informed decision-making. By enabling seamless data exchange and reducing manual efforts, this initiative promises to enhance productivity and profitability for farmers while enabling data providers to unlock the value of their interoperable data assets.publishedVersio
A novel framework for assessing the fracture toughness through the wall thickness of hydrogen pipelines
Get PDFThis article presents a novel model for assessing the fracture toughness in hydrogen pipelines. By combining experimental fracture toughness data with recognized hydrogen uptake and diffusion models, the local hydrogen-affected fracture toughness across the wall thickness of a hydrogen pipeline can be determined. The model specifically accounts for hydrogen concentration gradients across the pipe wall thickness and the existence of surface barriers. Presented results demonstrate that embedded defects may possess higher fracture toughness values compared to inner surface flaws for the same operating pressure, reducing their criticality compared to that of inner surface defects. The model has thus the potential to reduce conservative selection of hydrogen-affected fracture toughness, yielding less restrictive flaw-acceptance criteria in pipeline integrity assessments. The approach can efficiently be applied in combination with various integrity assessment methods as a readily accessible and easy to use engineering tool for fracture analysis of hydrogen pipelines and pressure vessels.publishedVersio
Knowledge sharing and learning in projects - Focusing on time restriction
Get PDFProjects can be seen as a learning arena. New knowledge can be developed, and existing knowledge can be shared in projects. Several projectbased organizations (PBOs) could see the importance of knowledge sharing and learning in projects – for instance to deal effectively with changes and uncertainty, and to increase productivity. However, they find it difficult to unleash a greater extent of potential benefits of learning and knowledge sharing. One of the difficulties that has been widely mentioned by practitioners and researchers is time restriction. This paper aims to look closer at how time restriction could play out its role in knowledge sharing and learning in PBOs. In addition, this paper addresses how to deal effectively with this barrier and provides suggestions for making improvement in organizational practices that can enhance knowledge sharing and learning. In order to address the topic of this paper, relevant data is collected through conducting interviews in PBOs in Norway. The interviews are of semi-structured nature. As a possible impact, the results can lead to further research by testing the suggestions in case projects or focusing on certain aspects of the results as an in-depth study.publishedVersio
Prosessveileder for ZEN
Get PDFDet overordnede målet med denne rapporten er å veilede partene i ZEN (som for eksempel ledende organisasjon(er), prosjekteiere, utviklere, prosjektleveranseteam osv.) som vil ha mandat til å gjennomføre prosjekter innenfor et nullutslippsområde (ZEN) og rollene til lokale myndigheter i å forme ZEN-ambisjoner gjennom strategisk planlegging. Rapporten viser på et overordnet nivå hvilke temaer som bør tas hensyn til i ulike faser ved planlegging, tilrettelegging, og evaluering av et ZEN, med et hovedfokus på fasene som dekker strategisk planlegging og reguleringsplanarbeid i et prosjekt.
I arbeidet med rapporten har vi hatt tre metodiske tilnærminger – litteraturgjennomgang, en kartlegging av eksisterende prosesser og lovverk, og vurderingskriterier og nøkkelindikatorer i ZEN, samt workshops for å supplere de førstnevnte tilnærmingene.
Rapportens hoveddel (kapittel 3) er organisert i fire deler. I delkapittel 3.1 dekkes planlegging etter Plan- og bygningsloven og rammene for hva som kan bestemmes med hjemmel i lovverket. Delkapittel 3.2 omhandler energiloven, som per i dag i stor grad er tilpasset enkeltbygg, noe som gjør at balansering på nabolagsnivå ikke insentiveres med dagens avregningspraksis når bygningene har ulike eiere. I delkapittel 3.3 introduseres et tabell-lignende verktøy som er ment å være et kunnskapsgrunnlag for å implementere prosjekter med ZEN-ambisjoner ved å ta hensyn til relevante ZEN-vurderingskriterier og nøkkelindikatorer på relevante skalaer (bygningsnivå, nabolagsnivå). I delkapittel 3.4 beskrives temaer som er av spesiell betydning i planleggingen av områder med ZEN-ambisjoner og som bør adresseres tidlig i planleggingen av prosjekter; lokalisering, definisjon av ambisjoner og mål, prosjektplan, kartlegging av regulatoriske barrierer og avhengigheter, politisk forankring, eierstruktur og kontrakt-strategier, utnevnelse av ZEN-ansvarlige, og interessentanalyser og strategier for brukerinvolvering.publishedVersio
Silicon kerf loss as a potential anode material for lithium-ion batteries
Get PDFIn this work, industrially processed silicon kerf loss (abbreviated to silicon kerf) from the photovoltaic industry is assessed as an anode material for the lithium-ion battery (LIB). The study includes both a characterization of processed silicon kerf from different sources and a comparison with commercially available nano-sized silicon (40 and 100 nm) in electrochemical testing. Such a direct comparison between these two silicon types in electrochemical testing provides a new insight into silicon kerf as an anode material. The silicon kerf particles are flake-like with varying lengths, with a mean particle size (d50) measured to ∼700 nm and a dimension of thickness of a few tens of nanometers. However, the specific surface area ranging from 20 to 26 m2/g is comparable to that of a silicon material of size ∼100 nm. The silicon oxide layer surrounding the particles was measured to 1–2 nm in thickness and, therefore, is in a suitable range for the LIB. In terms of electrochemical performance, the silicon kerf is on par with the commercial nano-sized silicon, further supporting the size evaluation based on the specific surface area considerations. Initial discharge capacities in the range 700–750 mAh/g (close to the theoretical value for the 12 wt% Si mixture with graphite) and first cycle efficiencies of 86%–92% are obtained. The cycling stability is comparable between the two materials, although the differential voltage analysis (DVA) of the galvanostatic data reveals that only the silicon kerf samples maintain silicon activity beyond 120 cycles. This study shows that industrially processed silicon kerf has characteristics similar to nano-sized silicon without reducing the size of the silicon kerf particles themselves. Considering its low carbon footprint and potentially lower cost, it can thus be an attractive alternative to nano-sized silicon as an anode material for the LIB industry.publishedVersio
Into the deep: Exploring the molecular mechanisms of hyperactive behaviour induced by three rare earth elements in early life-stages of the deep-sea scavenging amphipod Tmetonyx cicada (Lysianassidae)
Get PDFWith increasing socio-economic importance of the rare earth elements and yttrium (REY), Norway has laid out plans for REY mining, from land-based to deep-sea mining, thereby enhancing REY mobility in the marine ecosystem. Little is known about associated environmental consequences, especially in the deep ocean. We explored the toxicity and modes of action of a light (Nd), medium (Gd) and heavy (Yb) REY-Cl3 at four concentrations (3, 30, 300, and 3000 μg L−1) in the Arcto-boreal deep-sea amphipod Tmetonyx cicada. At the highest concentration, REY solubility was limited and increased with atomic weight (Nd < Gd < Yb). Lethal effects were practically restricted to this treatment, with the lighter elements being more acutely toxic than Yb (from ∼50 % mortality in the Gd-group at dissolved 689–504 μg L−1 to <20 % in the Yb-group at ca. 2000 μg L−1), which could be a function of bioavailability. All three REY induced hyperactivity at the low-medium concentrations. Delving into the transcriptome of T. cicada allowed us to determine a whole array of potential (neurotoxic) mechanisms underlying this behaviour. Gd induced the vastest response, affecting serotonin-synthesis; sphingolipid-synthesis; the renin-angiotensin system; mitochondrial and endoplasmic reticulum functioning (Gd, Nd); and lysosome integrity (Gd, Yb); as well as the expression of hemocyanin, potentially governing REY-uptake (Gd, Yb). While Nd and Yb shared only few pathways, suggesting a link between mode of action and atomic weight/radius, almost all discussed mechanisms imply the disruption of organismal Ca-homeostasis. Despite only fragmental genomic information available for crustaceans to date, our results provide novel insight into the toxicophysiology of REY in marine biota. The neurotoxic/behavioural effects in T. cicada at concentrations with potential environmental relevance warn about the possibility of bottom-up ecological consequences in mining exposed fjords and deep-sea ecosystems, calling for follow-up studies and regulatory measures prior to the onset of REY mining in Norway.publishedVersio
Greenhouse gas emission reduction opportunities for the Norwegian salmon farming sector - can they outweigh growth?
Get PDFNorwegian farmed Atlantic salmon is a nutritious type of food in increasing demand and although production has stagnated and is faced by various challenges, it is likely to continue to expand in the future. We present results from a detailed greenhouse gas emission assessment of the most important Norwegian farmed salmon export products along with improvement measures. By scaling up both baseline results and reduction opportunities, based on growth projections, we estimate current and future emissions of the sector as a whole. We show that export of gutted salmon to Europe by truck dominates Norwegian salmon exports, not only in volume and value, but also in emissions, followed by export of fresh gutted salmon and fillets to Asia and fillets to the US by air. The cumulative greenhouse gas emissions are dominated by feed production followed by emissions from overseas airfreighting of fresh products. The five most important emission reduction measures, based only on existing technology and without particular order were 1) slightly increased feed efficiency, 2) increased utilization of side streams occurring in secondary processing after export, 3) seafreight to market instead of road and air, 4) higher energy efficiency and cleaner energy sources, and 5) changed feed composition. Collectively, they have the potential to reduce greenhouse gas emissions of current production by 60%, from 5.2 to 2.1 million tonnes of CO2e, assuming the same relative importance of each supply chain. This implies that a medium growth-scenario, representing more than a doubling of the volume of salmon farmed to 3.3 million tonnes, would be possible while reducing total sector emissions by 16% if the improvement measures were fully implemented. For larger reductions, either lower growth or more ambitious implementation of improvement measures is needed. Although greenhouse gas emissions are often linked to resource efficiency and wider sustainability, this is not always the case, and it is important to avoid shifting burdens from climate to e.g. eutrophication or biodiversity impacts. However, many environmental impacts of salmon farming are centered around feed efficiency, and even problems with welfare, escapees, and in part eutrophication are reflected in lower feed efficiency resulting in higher greenhouse gas emissions. In addition to the systematic collection of robust data for more continuous monitoring of greenhouse gas emission performance over time, we therefore recommend identifying additional indicators to monitor to ensure the sector develops not only towards climate neutrality but also towards broader sustainability.publishedVersio
Automated monitoring of early life-stage development in Atlantic cod (Gadus morhua) embryos exposed to a reference toxicant
Get PDFEarly life stages of fish are widely used for regulatory toxicity testing, and marine fish display high sensitivity to pollutant exposure. Exposure to pollutants during embryogenesis causes acute effects on embryonic development and survival, but also sub-lethal impacts manifested as maldeveloped larvae. Acquiring time- and exposure-dependent responses to pollutant exposure and other stressors in small organisms is labor intensive and often subjective. This leads to studies obtaining small sample sizes, with measurements often made infrequently during development. Automated monitoring methods can maintain consistency between measurements and allow many more measurements to be made, improving the quantity and quality of such data. We exposed Atlantic cod embryos to 3,4-dichloroaniline, a reference chemical widely used as a positive control agent in regulatory fish embryo toxicity testing. We monitored their growth through daily imaging with an automated flow-through imaging system. Biologically relevant sublethal endpoints were estimated from these images with a neural network and traditional machine vision methods. We demonstrate the automated capture and analysis of tens of thousands of images, producing detailed morphometric data from hundreds of fish over a 10-d study period, and assess the effectiveness of the automated system. The automated method presented allows measurements to be made frequently without sacrificing the sampled organisms, making detailed time series of development obtainable. We show dose-dependent effects of the toxicant on development and capture nonlinear responses that would not be attainable under a conventional manual sampling regime.publishedVersio