Tieto (Finland)

In Phys. Rev. A 108, L060402 (2023), we introduced a Bayesian measurement error mitigation algorithm, which leveraged complete information from the readout signal, and validated the protocol on a quantum device with five superconducting qubits. Here, we present an improved algorithm's implementation, tailored for multiqubit experiments on near-term superconducting qubit quantum devices. In particular, we provide a detailed algorithm workflow, from calibrating the detector response functions to the postprocessing of measurement outcomes, offering a computationally efficient solution for the output size typical of current quantum computing devices. We show how the numerical representation of the noise function affects the performance of the error mitigation algorithm and test the convergence criteria. We benchmark our protocol on actual quantum computers with superconducting qubits, where the readout signal encodes the measurement information as unprocessed analog data before qubit state assignment. Finally, we compare the performance of our algorithm against other measurement error mitigation methods, such as iterative Bayesian unfolding and the Mthree method, and show how our method can be integrated on top of other readout error mitigation protocols.

ObjectivesFinnsheep, a highly prolific breed of sheep, has been globally exported for improving fertility traits of many sheep breeds. Published genomic studies of Finnsheep have been based on Texel and Rambouillet reference genomes, which may not capture its unique genetic features. Our main objective was to generate a high-quality Finnsheep genome assembly and its annotation that could serve as a breed-specific reference for studying fertility and adaptation in Finnsheep and other short-tailed northern European sheep breeds. Data descriptionWe generated a 2.53 Gb assembly using PacBio HiFi long-reads and Hi-C sequencing from a highly fertile Finnsheep ewe. The assembly, scaffolded with Hi-C data has a contig N50 of 35.5 Mb and scaffold N50 of 100.6 Mb. Gene annotation identified 42,533 genes spanning 46.5 Mb of coding region. BUSCO completeness for the assembly and annotation was 94.9% and 84.3%, respectively. This data, including raw reads, assembly, and annotations supports genomic studies of Finnsheep and other prolific breeds of sheep that are particularly adapted to northern European environments.

Abstract Biochar (BC) and hydrochar (HC) have gained attention as multipurpose materials for soil improvement, plant growth promotion, carbon removal and waste reduction – key components of the circular economy. Heterogeneous side-stream and waste biomasses together with thermochemical processes produce variable char products whose effects on soil properties and plants may be divergent and dependent on the environmental context. We produced BC and HC from demolition wood, tomato leaves and biogas digestate and characterized chemical and physical properties of feedstock materials and char products. Growth chamber experiments were established to evaluate the phytotoxicity of the char products and their effects on seedling emergence, biomass and nutrient concentrations in three crop indicator species (barley, radish and rape) grown in a boreal soil. We found that both slow pyrolysis and hydrothermal carbonization (HTC) produce mostly good-quality char products within the limits of the EU Fertilising Products Regulation (FPR) 2019/1009. The effects of BC and HC applications on soil properties reflected the characteristics of the char products and application rates. In general, all char treatments increased soil pH, carbon content and organic matter. Effects of char products on emergence and growth depended on the plant species, sowing time, char treatment and application rate, with many interactive effects of treatments. Immediate phytotoxicity was shown by the highest application rate (50 t ha−1) of tomato BC which reduced emergence in all species. Overall, char application had explicit positive effects on biomass in barley only. Our results suggest that pyrolysis and HTC are valuable methods in processing different side-stream and waste materials into char products that are potential soil amendments. Harmful effects of char application are rare with high-quality products, but the observed patterns of short-term plant responses emphasize the need for environment- and species-specific testing of soil amendments. Graphical Abstract

We design a novel grating out-coupler while maintaining a Gaussian-shaped far-field output. The approach is based on the patterning of a grating in a SiGe layeron the top surface of a 3-µm-thick Si waveguide. The grating aims at coupling the guided signal into a beam vertically out from the surface of the chip, i.e., out-coupling. The use of a high refractive index alloy, i.e., silicon-germanium, allows a tunability of the effective index of the guided mode and to modify the field distribution enabling a higher efficiency of the grating. It yields a theoretical efficiency of 75% at the central wavelength of 1583 nm. The overall length of this grating coupler is 500 µm, and the output light is detected at 1 m above the grating. This type of long grating coupler is intended to be eventually used as sensor in LiDAR (Light detection and ranging) applications.

Recently, cellulose nanofibers (CNFs) have attracted attention because of their potential as building blocks in materials science. Their production, however, is often seen as inefficient and the tuning of their properties is not straightforward. Contrary to exploiting costly and environmentally taxing delignified wood pulp as a raw material, this study demonstrates CNF production using agricultural waste: potato fibers. The process for obtaining typical long (μm scale) CNFs involved alkali treatment, NaClO2 addition, and gaseous HCl hydrolysis, while TEMPO-mediated oxidation enabled tuning of the CNF length to much shorter (∼500nm) nanofibres with substantial carboxylate content (1.0mmol/g). Subsequent film preparation demonstrated that even short CNFs could form strong transparent films (nanopapers). These findings provide a foundational understanding of the practical implementation of cellulose gaseous HCl hydrolysis and TEMPO-mediated oxidation techniques, extending from the potato fiber industry to nanocellulose applications.

Promising intrinsic electronic properties, such as narrow bandgap and high charge carrier mobilities, make germanium (Ge) a good replacement for silicon in optoelectronic applications (e.g., photodetectors). However, successful fabrication of efficient Ge devices requires minimization of both reflectance and surface recombination losses. This work begins with an observation that metal‐assisted chemical etching (MACE) of Ge surfaces, used for optics improvement, reduces surface recombination without application of any intentional passivation. We proceed with investigation of the effect of MACE solution components and their mixtures on Ge surface passivation. The results demonstrate that HF:H2O2 aqueous solution leads to efficient and stable passivation. The film formed in this solution secures surface recombination velocity (Seff) of 14 cm s−1. Morphological and chemical characterization of the structure reveals porous germanium (PGe) layer with some GeOx included. Finally, we propose several hypotheses on a mechanism behind this passivation, among which are the presence of GeO2 at the film‐bulk Ge interface and appearance of a potential barrier due to the heterojunction formation. The presented Ge passivation with PGe layer provides a simple and cost‐efficient alternative to existing state‐of‐the‐art passivation schemes.

As a source of exogenous organic matter, pulp and/or paper mill sludges (PPMS) may have beneficial effects on crop productivity and soil chemical and physical properties. This study's aim was to assess the impacts of two different PPMS materials on crop yields, the quality of percolation water, and soil chemical and hydraulic properties in a three-year field experiment on a silt loam soil in East Central Finland. Fresh (FPMS) and lime-stabilized (LPMS) sludges were applied once at rates of 21–28 fresh-Mg ha−1 in the spring prior to the sowing of grass ley under barley as a cover crop and incorporated into the upper 7 cm soil layer. Supplemental nitrogen (N) was applied at levels of 40 and 80 kg ha−1. A decrease of barley grain yield due to N immobilization was observed at the N level 40 kg ha−1, but the standard N application rate (80 kg ha−1) connected with a moderate C:N ratio (FPMS 27:1, LPMS 24:1) was adequate to avoid significant yield losses. In the second and third year following the PPMS applications, there was a tendency for positive residual effects on the total dry matter yield of grass ley, which could be attributed to slow mineralization of sludge-N. The application of LPMS increased the pH in surface soil by 0.5–0.7-units and Ca concentration by 240–660 mg L−1 of soil relative to the non-amended control over the study period. In the year of PPMS applications, the amendments produced a significant increase (about 2.0 g kg−1) in the total carbon (C) concentrations in the uppermost 10 cm soil layer relative to the non-amended soil. During the following years, the change in soil C was no longer measurable, indicating relatively fast decomposition of sludge-C. Saturated hydraulic conductivity tended to be 1.4 to 2.3 times higher in the PPMS-treated soils than in the non-amended soil. Except for the decline in readily plant-available water, the other common water retention parameters were not significantly affected by the PPMS amendments. There were significant positive treatment effects on the amount of water retained between −13 and − 316 kPa matric potentials, suggesting an increase in medium-sized pores contributing to water storage in the soil. To maintain or enhance the beneficial direct and indirect effects of PPMS on crop yields and soil physico-chemical properties, repeated applications of PPMS are required, possibly combined with the use of organic fertilizers, especially during grass ley years.

Abstract Modern batteries are highly complex devices. The cells contain many components—which in turn all have many variations, both in terms of chemistry and physical properties. A few examples: the active materials making the electrodes are coated on current collectors using solvents, binders and additives; the multicomponent electrolyte, contains salts, solvents, and additives; the electrolyte can also be a solid ceramic, polymer or a glass material; batteries also contain a separator, which can be made of glass fibres, polymeric, ceramic, composite, etc. Moving up in scale all these components are assembled in cells of different formats and geometries, coin cells and Swagelok cells for funamental testing and understanding, and pouch, prismatic and cylindrical cells for application. Given this complexity dictated by so many components and variations, there is no wonder that addressing the crucial issue of true sustainability is an extremely challenging task. How can we make sure that each component is sustainable? How can the performance can be delivered using more sustainable battery components? What actions do we need to take to address battery sustainability properly? How do we actually qualify and quantify the sustainability in the best way possible? And perhaps most importantly; how can we all work—academia and battery industry together—to enable the latter to manufacture more sustainable batteries for a truly cleaner future? This Roadmap assembles views from experts from academia, industry, research institutes, and other organisations on how we could and should achieve a more sustainable battery future. The palette has many colours: it discusses the very definition of a sustainable battery, the need for diversification beyond lithium-ion batteries (LIBs), the importance of sustainability assessments, the threat of scarcity of raw materials and the possible impact on future manufacturing of LIBs, the possibility of more sustainable cells by electrode and electrolyte chemistries as well as manufacturing, the important role of new battery chemistries, the crucial role of AI and automation in the discovery of the truly sustainable batteries of the future and the importance of developimg a circular battery economy.

The Covid-19 pandemic increased enormously the manufacturing and usage of face masks and other personal protective equipment (PPE), resulting in accumulation of plastic waste and, thus, causing universal environmental concerns. In addressing the issue of waste reduction and finding alternatives for fossil-based products, investigation of different biobased and biodegradable polymers plays a crucial role. This study examines the processability characteristics of three commonly used biobased polymers available in the market: biobased poly(lactic acid) (PLA), partly biobased and biodegradable poly(butylene succinate) (PBS), and biobased high-density poly(ethylene) (BioHDPE). The investigation combines substantial polymer analysis with subsequent processability trials in two different spunmelt processes, namely, meltblow (MB) and the Nanoval technology, aiming to reveal the differences and difficulties in the processing behavior and pointing out advantages and/or disadvantages of the respective polymer/technology combination. In general, the observed processability behavior and outcomes indicate that within the used processes PLA exhibits superior processability compared to PBS and BioHDPE. Both the meltblow and Nanoval processing of PLA demonstrated a consistent production of fibers and efficient uptake without any compromise on the throughput. In contrast, the processing of PBS using Nanoval required the utilization of significantly elevated temperatures, as indicated by a rheological study. Furthermore, the rheological evaluation revealed that the viscosity of BioHDPE was excessively elevated, rendering it unsuitable for effective processing by the Nanoval method. The microfibers in the PLA-based meltblown fabric had a higher surface area, explaining why the PLA fibers were able to function as a barrier and, thus, contribute to the mitigation of air permeability adjustable between 500 and 1000 l·s-1·m-2 and thus competitive or even superior to PP nonwovens of the same fiber diameter and base weight (1480 l·s-1·m-2). Overall, these results showed that PLA can be an alternative raw material for fossil-based nonwovens of PPE applying, especially, the meltblown technique.