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Flexible Cu2AgBiI6-based perovskite-inspired solar cells using large-scale processing methods
No full textIn this work, emerging perovskite-inspired Cu2AgBiI6 (CABI) solar cells were successfully fabricated on flexible substrates, demonstrating that the transition from rigid to flexible materials does not compromise device performance. This underscores the versatility of CABI on two different kinds of substrates. Additionally, to optimize charge extraction, we selected a polymeric hole-transport material (HTM), PPDT2FBT, whose energy levels align with CABI. The PPDT2FBT-based devices outperformed those using the well-known poly(3-hexylthiophene) (P3HT), leading to power conversion efficiencies as high as approximately 0.8%. These results suggest that PPDT2FBT may hold promise as a HTM for use in low-toxicity, perovskite-inspired photovoltaic systems, such as those based on CABI. Furthermore, roll-to-roll processing techniques, crucial for scalable production, were tested. However, controlling the morphology of the active layer remains a significant challenge. These findings represent critical steps toward the large-scale manufacturing and commercialization of flexible, PIM-based solar cells
Modeling Thermal Effects in Atomic Layer Deposition for Trench-Shaped Structures
No full textAn atomic layer deposition (ALD) simulation approach is presented for transient diffusion of heat and mass at low Knudsen numbers (Kn < 0.1), focusing on thermal effects in trench-shaped structures. Two boundary conditions (BCs) are analyzed: the ‘thin wall’ BC incorporates exothermic reactions with a derived wall heat flux term, and the ‘thick wall’ BC maintains constant wall temperature ranging between 500 K and 800 K. For both BCs, we examine aspect ratios from 1 to 100. The chosen BC significantly impacts reaction kinetics/peak temperatures, with local temperature variations up to 200 K under ‘thin wall’ conditions. The coating time ratio between ‘thin wall’ and ‘thick wall’ ranges from 0.9 to 1.7. Two ‘universal’ functional forms are proposed to explain how surface coverage depends on time and how coating time relates to aspect ratio and diffusion timescale. Results emphasize the crucial role of temperature distribution in ALD, impacting growth per cycle, reactant decomposition/desorption, and potential substrate damage
Oxide Formation at the Sulfide Film-Copper Interface in Anoxic Sulfide Solution and On-Line Sulfide Detection Via Linear Polarization Resistance
Full text linkThe observation of a thin oxide film on oxygen free phosphorous doped copper after several days of exposure in supposedly anoxic conditions poses several questions, where the most straight-forward answers regarding sample preparation and handling is oftentimes overlooked. In an effort to minimize the environmental factors contributing to the oxide formation on the copper surface, a flow through cell arrangement was built to investigate the oxide formation at the Cu–Cu2S interface after exposure to anoxic sulfide containing phosphate buffer solution. The post exposure characterization by scanning electron microscopy and focused ion beam revealed no oxide formation on the copper surface in the absence of oxygen, while the exposure of the copper surface during the metallographic sample preparation phase, which employs the use of aerated water, causes the formation of copper oxide. Furthermore, a novel technique for noninvasive, semi-quantitative, and on-line sulfide determination is presented. The anodic current density determined from the linear polarization resistance of copper in sulfide solution was found to linearly increase with sulfide concentration.</p
Incorporation of a pyrethroid-based insecticide system into regenerated cellulose:interfacial interactions and effect on fiber formation
No full textInsecticide treated nets (ITNs) are a key tool for controlling vector-borne diseases, such as malaria. However, they are traditionally made of non-renewable polymeric materials, which lack sustainability and longevity. The goal of this research is to address this issue by developing renewable, bio-based fibers that can carry insecticides while remaining suitable for netting fabric, using readily available and abundant cellulose as a raw material. To achieve this, understanding the underlying interactions between insecticides and cellulose is necessary, especially under the dissolution and regeneration conditions. Permethrin, a type of pyrethroid insecticide used in ITNs to kill malaria mosquitoes, is often mixed with piperonyl butoxide (PBO) to combat insecticide resistance. In this study, the adsorption of permethrin and PBO onto cellulose model surfaces treated with two potential direct dissolution solvents (deep eutectic solvent and ionic liquid), which yielded different allomorphs of cellulose, and was examined using surface-sensitive methods. The insecticides were then incorporated into the ionic liquid containing dissolved cellulose, processed into fiber via dry-jet wet spinning, and evaluated for mechanical performance and insecticide retention
Towards 2040:Collaborative approach in Finnish food systems transition
Full text linkThis article presents experimental research that engaged Finnish stakeholders in discussions on how to transition global food systems toward sustainability by 2040, addressing urgent challenges such as climate change, resource depletion and population growth. The study introduces the “Future Food Court Workshops,” which involved representatives from various sectors, including industry, public institutions, third-sector organizations, educational entities, and consumers. To guide these discussions, the research developed an integrated framework combining social design, foresight, technology, and business perspectives, aiming to anticipate emerging needs and societal transformations. The workshops employed “Five Dimensions of Futures Consciousness” model for qualitative analysis of the stakeholder engagement; the model was used explicitly to understand how participants conceptualized the future of food systems. The analysis revealed, for example, how participants experienced sustainability challenges, their capacity for future-oriented behavior, the impact of present actions on future outcomes and the role of emerging technologies reflecting values of the systems they serve. This research advances the field of futures studies by demonstrating an interdisciplinary approach to engaging stakeholders in sustainable food system transitions, and hopefully offers valuable insights for researchers, policymakers, and practitioners, underscoring the necessity of adopting sustainable practices to address pressing environmental concerns.</p
Automating Customer Feedback Analysis in E-commerce: A Multi-Model Approach
No full textUnderstanding customer satisfaction in e-commerce is crucial for businesses to remain competitive. While traditional feedback analysis methods are labour-intensive and subjective, machine learning advances have enabled more efficient and scalable sentiment analysis. However, existing models struggle with aspect-based sentiment analysis (ABSA), particularly in detecting implicit aspects and handling mixed sentiments. This paper presents a multi-model machine learning pipeline designed to enhance ABSA by integrating fine-tuned Large Language Models (LLMs) with BERT and RoBERTa-based models. The pipeline consists of an LLM-generated synthesized annotated feedback model, a BERT-based aspect detection model, a RoBERTa-based ABSA model, and an LLM-based ABSA model for handling implicit aspects and mixed sentiments. Additionally, a RoBERTa-based model is employed for overall sentiment detection. By leveraging both manually annotated and synthetic data, the pipeline improves sentiment classification accuracy and aspect coverage, even in data-scarce environments. The results demonstrate that combining multiple models enhances detection accuracy compared to single-model approaches. This study provides a scalable and effective solution for e-commerce feedback analysis, offering businesses valuable insights for improving customer experience and decision-making
A Survey on Detection, Classification, and Tracking of AAVs Using Radar and Communications Systems
No full textThe use of autonomous aerial vehicles (AAVs) for a variety of commercial, civilian, and defense applications has increased many folds in recent years. While AAVs are expected to transform future air operations, there are instances where they can be used for malicious purposes. In this context, the detection, classification, and tracking (DCT) of AAVs (DCT-U) for safety and surveillance of national air space is a challenging task when compared to DCT of manned aerial vehicles. In this survey, we discuss the threats and challenges from malicious AAVs and we subsequently study three radio frequency (RF)-based systems for DCT-U. These RF-based systems include radars, communication systems, and RF analyzers. Radar systems are further divided into conventional and modern radar systems, while communication systems can be used for joint communications and sensing (JC&S) in active mode and act as a source of illumination to passive radars for DCT-U. The limitations of the three RF-based systems are also provided. The survey briefly discusses non-RF systems for DCT-U and their limitations. Future directions based on the lessons learned are provided at the end of the survey.</p
Preparing a social impact bond in a Nordic welfare state: governance challenges and hybrid responses
No full textPurposeThis study aims to examine the preparation of a complex Social Impact Bond (SIB) project in Finland, exploring how challenges and solutions reflect the interplay between new public management (NPM) and new public governance (NPG) logics. It contributes to debates on the institutional adaptability of SIBs beyond Anglo-American contexts.Design/methodology/approachThe authors conduct a longitudinal case study of the Children’s SIB II in Finland, analysing data from 21 stakeholder interviews. Five preparation phases are identified and examined for governance dynamics and challenge-response logics.FindingsThe findings show how SIB preparation involved hybrid governance, combining NPM tools, such as performance-based incentives, with NPG principles like trust-building and cross-sector collaboration. While many challenges were initially framed through NPM logics, their resolution often leaned towards NPG-style responses, highlighting the adaptive use of relational governance practices. A key insight is the critical role of a publicly funded intermediary in framing the SIB, mobilizing networks and embedding the instrument within national welfare discourses.Social implicationsHybrid governance tools like SIBs can reinforce trust-based public-private cooperation and support developing responses to complex social issues, but they also require significant institutional capacity.Originality/valueThis study extends the literature on SIBs by examining their preparation in a Nordic welfare state context, distinct from the Anglo-American settings where SIBs have been most studied. It contributes novel insights into how hybrid governance unfolds in such contexts, particularly how NPG-style solutions emerge even when problems are framed through NPM logics. It also highlights the overlooked role of public institutional intermediaries in shaping SIB development beyond technical and financial coordination.<br/
TRIM:Thermal Auto-Compensation for Resistive In-Memory Computing
No full textin-memory computing (IMC) has emerged as one of the most promising architectures to efficiently compute artificial intelligence tasks on hardware, particularly deep neural networks (DNNs). IMC can make use of analog computation principles alongside emerging nonvolatile memories (eNVM) technologies, potentially offering several orders of magnitude increased energy efficiency compared to generic processing units. Yet, the use of analog circuitry, potentially integrated with emerging technologies post-processed on top of silicon wafers, increases the susceptibility of hardware to a large spectrum of variations, for instance manufacturing, noise or temperature sensitivity. Hence, this susceptibility can hamper the large-scale deployment of IMC circuits into the market. To tackle the reliability of analog resistive-based IMC circuits regarding temperature variations, this article presents TRIM, a thermal on-chip auto-compensation method aimed at fully calibrating first-order temperature effects. TRIM is designed to maintain the computational accuracy of IMC cores in DNN applications over a wide temperature range, while being highly scalable and adaptable. In essence, the temperature compensation is realized through a complementary-to-absolute-temperature (CTAT) voltage reference integrated inside a voltage regulator and applied at the zero reference node of a multiplying digital-to-analog converter (MDAC), eliminating the need for external circuits or look-up table. The proposed methodology is demonstrated on a proof-of-concept 65 nm CMOS resistive IMC column. Measurement results showcase that the proof-of-concept auto-compensation system significantly enhances inference and multiply-and-accumulate (MAC) operation accuracy of any first-order resistive crossbar column, achieving inference accuracy recovery of 100% over a temperature range of –20 °C to 60 °C and a 91.3% improvement in MAC operation accuracy, with an area overhead of 2% and power overhead of < 0.02%.</p
Oxide Formation at the Sulfide Film-Copper Interface in Anoxic Sulfide Solution and On-Line Sulfide Detection Via Linear Polarization Resistance
No full textThe observation of a thin oxide film on oxygen free phosphorous doped copper after several days of exposure in supposedly anoxic conditions poses several questions, where the most straight-forward answers regarding sample preparation and handling is oftentimes overlooked. In an effort to minimize the environmental factors contributing to the oxide formation on the copper surface, a flow through cell arrangement was built to investigate the oxide formation at the Cu–Cu2S interface after exposure to anoxic sulfide containing phosphate buffer solution. The post exposure characterization by scanning electron microscopy and focused ion beam revealed no oxide formation on the copper surface in the absence of oxygen, while the exposure of the copper surface during the metallographic sample preparation phase, which employs the use of aerated water, causes the formation of copper oxide. Furthermore, a novel technique for noninvasive, semi-quantitative, and on-line sulfide determination is presented. The anodic current density determined from the linear polarization resistance of copper in sulfide solution was found to linearly increase with sulfide concentration.</p