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Towards Sustainable Weed Management Using Lightweight Deep Learning Model
No full textThe exponential growth of population has resulted in food safety becoming a major concern in global context. To provide food for people and livestock worldwide, it is crucial to implement intelligent solutions that cater to the specific needs of crop cultivation, while maintaining soil quality. Maize holds higher potential than other major crops as it is widely used as industrial raw material, bio-ethanol production, feed and fodder for cattle, besides its primary use as food. Weed management plays a crucial role in maize agricultural practices as it helps ensure optimal crop growth and yield. Conventional weed control methods have limitations that hinder their effectiveness for future weed management. Also, Weed management has become increasingly challenging due to the over-reliance on herbicides that has accelerated the evolution of herbicide-resistant weeds among increasing concerns about effect of pesticides on environment and human health. As a result, there is a growing need for an integrated approach that combines different strategies and utilizes new technologies towards precise and efficient weed management. The work in the following paper utilizes the YOLOv5 object detection algorithm to detect and classify weeds in images. The trained model can then be used for inference on new images to identify and classify weeds.</p
Investigating tritium retention in tungsten coated plasma facing components from the divertor region of the Joint European Torus (JET) after ITER like-wall campaigns
No full textTritium retention is a critical aspect of plasma-facing wall component performance in fusion reactors as well as reactor safety due to radiological risks it may pose. It is also of importance in the case of tungsten, including tungsten composites, which are selected as first wall and divertor material at devices such as ITER due to its high melting point and mechanical strength. This study aims to investigate surface characteristics, tritium retention behaviour and effect of baking on tungsten composite plasma-facing wall components from Joint European Torus (JET) divertor region and contribute to the understanding of tritium trapping within them. Three ITER-like wall (ILW) experimental campaigns involved exposing tungsten-molybdenum coated carbon fibre composite (CFC) samples to deuterium-deuterium (D-D) plasma discharges at various operating conditions, including different plasma densities, temperatures, and exposure times. The plasma-facing surfaces were characterized using scanning electron microscopy (SEM) in combination with energy-dispersive x-ray spectroscopy (EDX) and tritium retention was assessed using thermal desorption spectroscopy (TDS) and full combustion. Baking cycle was simulated by keeping the sample at 350℃ for 100 h, followed by TDS and full combustion. Results indicate tritium retention varying from 2 to 120∙1012 T atoms/plasma facing surface cm2. A deposition layer was found to be present for most samples analysed in this study ranging from 0 to 58 µm in thickness. For Tile 0 an increase in tritium retention was observed by the increase in the thickness of the deposition layer, whilst for Tile 1 deposition was not found to be the main source of retention. Tritium desorption temperatures were found to be higher than that proposed for baking at ITER − for Tile 0 tritium desorption peaks at about 540-640℃, while for tile 1 it is generally lower, but with a larger deviation ranging from 350 up to 570℃.</p
Collaborative Digitalisation and the Future of Networked Production:Exploring Decentralised Technical Intelligence in Supply Chains
No full textNetworked production, supported by advanced logistics and supply chain processes, is crucial for companies to stay competitive and foster cooperation and integration of production resources. It replaces sequential processes with dynamic arrangements, presenting challenges like managing product variants, short life cycles, and process optimisation. Agility is vital for adapting to changes and natural disasters. Decentralised Technical Intelligence (DTI) is an approach that manages complexity and incentivises integrating new technologies in planning and manufacturing. DTI involves distributed and autonomous intelligence embedded in interconnected systems, where humans and machines collaborate to achieve common goals. Humans bring unique skills like creativity and intuition, complementing AI’s capabilities. DTI relies on a multi-agent architecture, enabling trust, interoperability, and data sharing for better decision-making and efficiency. The EU knowlEdge project exemplifies this by providing AI solutions that are distributed, secure, standardised, and collaborative, integrating cognitive technologies, data analytics, IoT and more. DTI’s human-centric design fosters a different quality of intelligence, leading to greater autonomy within multi-agent systems. To realise advanced networked production, a roadmap must be implemented, focusing on a vision, value promise, and development pathway. Europe can maintain its leadership in future networked production through this approach.</p
Deep Life Under Pressure: Hydrogen Formation and Microbial Signatures in Precambrian Crystalline Bedrock
No full textPhotonic contact thermometry based on 3 µm thick silicon cascaded ring resonators
No full textWe demonstrate a photonic temperature sensor based on three silicon cascaded ring resonators (CRRs) integrated on a 3 µm thick silicon-on-insulator (SOI) platform for contact thermometry. A CRR-based sensor achieves an expanded free spectral range (FSR) of 23 nm, enabling a broader operational temperature range compared with the FSR of 1 nm for the single ring resonator. The thick SOI platform offers several advantages, including low propagation loss (less than 0.1 dB cm-1), negligible polarization dependence (approaching zero birefringence) and high-power handling capability (greater than 10 mW) without any resonance shape deformation from two-photon absorption (TPA). Optical coupling was achieved through edge-coupled fibre packaging to the photonic chip. The sensor exhibits a temperature sensitivity of 85 pm K-1 with an uncertainty of 16.1 mK, measured over a temperature range from -20 to 90°C. This article is part of the Theo Murphy meeting issue 'The redefined kelvin: progress and prospects'.</p
Production of high-concentration CO2 from electrified limestone calcination for carbon capture applications
Get PDFOperating electrically heated kilns under high-CO2 atmospheres can increase CO2 capture efficiency but creates reducing conditions that drive CO formation. In this work, CO generation during limestone calcination in a 280 kW electrically heated rotary kiln at 75 vol-% CO2 and low O2 concentration is investigated. Equilibrium calculations indicate that sulphide and sulphite phases in limestone decompose, releasing SO2 and promoting CO formation. Complementary packed-bed experiments confirm that sulphur species are a major CO promoter and reveal a synergistic interaction between sulphur compounds and elevated CO2 levels. Using low-sulphur limestone could suppress CO emissions. Where low-sulphur feedstocks are unavailable, targeted electrolytic O2 or air injection coupled with indirect limestone preheating is proposed to strip sulphur and preserve the high-purity CO2 stream which will improve the efficiency of electrified kilns integrated with a carbon capture process
Finite-time Convergence Neural Network based Force-Motion Control for Unknown Surface with Orientation Compliance
No full textIn this paper, an adaptive force-motion control framework with orientation compliance is present for redundant manipulators in physical interaction with unknown surfaces. The proposed framework includes control task space definition and double-closed-loop control based on external force loop approach. Firstly, a specification matrix is designed merely through force feedback to ensure the control task space defined in orthogonal spaces. Then, an orientation compliance controller and a force-motion close-loop controller are constructed in the outer-loop control of external force feedback loop approach. Secondly, the output of outer-loop control task, along with boundary constraints and optimization indexes is formulated as a nolinear dynamic programming problem. Next a finite-time convergence neural network based inner-loop controller is proposed for this category of dynamic programming problem and its stability and convergence analysis are given. Simulations verify the convergence and effectiveness of the proposed framework. The real-world experiments show that the Mean Integral of the Absolute Error of the proposed control framework is reduced by 77.26% compared with constant impedance control.</p
Effect of spatially non-uniform boronization on plasma restart in WEST
No full textThe recent ITER re-baseline with the adoption of a full-W wall calls for mandatory boronization studies. ITER pulses will be inboard limited on the W tiles of the central column for several seconds during the current ramp up phase. Our first question of this study is: will it be possible to efficiently start plasma operations in a full-W ITER without any boronization? In particular, throughout the start of research operations (SRO), ITER will be equipped with an asymmetric boronization system as glow anodes in the equatorial plane will not be uniformly distributed in the toroidal direction due to the limited availability of ports. According to recent simulations, such arrangement of the glow anodes could lead to a strongly non-uniform B layer with depleted regions. Our second question hence is: should a boronization be needed to start plasma operations in ITER, would a non-uniform B layer be enough? In November 2024, we attempted to restart WEST plasma operations without boronization after a vent and after installing new bulk W limiter tiles. In about 4 days of operation corresponding to 74 pulse attempts, we reached a maximum pulse duration of 1.55 s and a maximum plasma current of 600 kA. Plasmas were cold and dense, mostly detached from the inboard limiter and dominated by light impurities with radiated power fractions close to unity. No runaway electron beams were observed but the restart without boronization was not timely. We then carried out the first WEST boronization utilizing only 3 out of 6 diborane (B2D6) inlets (half torus), to deposit a non-uniform B layer. Repeatable, 10 s long, ohmic limiter pulses were immediately achieved with radiated power fractions between 50 % and 70 %. Through a separate experiment in February 2025, we achieved matching pulses before and after a second non-uniform boronization to better characterize its effects: the radiated fraction initially dropped by 22 % with the reduction mainly occurring in the central plasma and well correlating with lower UV signals for O, N and W. These effects almost vanished by the end of the first day after the non-uniform boronization corresponding to a cumulated injected energy of 0.7 GJ.</p
Biosynthetic optical waveguide interface integration using biomimetic - <i>de novo</i> design ELP for optoelectronic applications
Get PDFThe integration of biologically inspired materials into photonic device fabrication offers a promising route toward sustainable and biocompatible alternative to conventional in inorganic or petroleum based synthetic materials used in optoelectronic systems. In this work, we present a biosynthetic approach for waveguide fabrication utilizing a biomimetic - de novo designed elastin-like polypeptide (ELP) formulated into an all-water-based photoresist compatible with two-photon polymerization (2PP). The ELP was genetically engineered and recombinantly produced in microbes for enhanced molecular stability, a critical feature for withstanding both localized and bulk temperature increases that occur during high-intensity laser exposure during printing. The resulting ELP formulation supported direct writing of waveguide architecture without the need for organic solvents, harsh processing steps, or post-functionalization. This aqueous resist formulation exhibits high stability during printing and retains its structural integrity upon curing, making it a promising candidate for environmentally friendly, soft-material photonics. This work establishes a foundation for using biosynthetic polypeptides in the fabrication of functional photonic elements and demonstrates a step toward greener, protein-based optoelectronic manufacturing technologies
Unexpected low temperature crack propagation in nuclear post-shutdown water chemistry of Alloy 52 with potential effects of hydrogen
No full textConstant-displacement bolt-loaded compact tension specimens of Nickel-based Alloy 52 were exposed to boiling water reactor environment for 12 years, followed by an additional 3 years in post-shutdown cold water conditions in a Swedish nuclear power plant test loop, under a stress intensity factor of 20 MPa√m. After outer surface decontamination and specimen opening, unexpected crack extensions of 3–4.5 mm were observed. The fracture surface and the cross-sectional deformation microstructure were examined by electron microscopies techniques down to the nanoscale. The oxide layer in the region exhibiting unexpected crack growth was notably thin, suggesting that it formed after exposure to elevated operating temperatures. The dominant fracture mode is transgranular, propagating along close-packed {111} planes. The grains contained heterogeneous microstructures with regions enriched in nanometer-sized Ti(N,C) and the zigzag crack paths did not traverse these regions strengthened areas. Extensive shear bands were present near the crack tips, indicating pronounced localized plasticity. Hydrogen reduces stacking fault energy, results in localized plasticity and enhances shear bands formation. Low temperature crack propagation with evident effects of hydrogen was considered as the potential cause of crack propagation in Alloy 52 in the absence of external dynamic loading under post-shutdown cold water chemistry