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Synergistic effects of carbon fibre and limestone powder on the mechanical performance and eco-efficiency of electrically conductive cementitious composites [Efeitos sinérgicos de fibra de carbono e pó calcário no desempenho mecânico e ecoeficiência de compósitos cimentícios condutivos]
No full textThis study evaluates the synergistic effects of carbon fibre and limestone powder on electrically conductive cementitious composites (ECCC) properties, considering fresh and hardened states, electrical conductivity, eco-efficiency, and microstructure. An experimental design comprising eight mixtures was adopted, varying the carbon fibre content (0.00, 0.50, and 1.00 wt.%) and replacing cement with limestone powder (0.00, 10.00, and 20.00 wt.%). The investigated properties included consistency, compressive and flexural tensile strengths, elastic modulus, water absorption, electrical resistivity, and microstructural analysis by scanning electron microscopy. A polynomial regression model was used to evaluate the significance of the main effects and their interactions. The combination of 0.5% carbon fibre and 10–20% limestone powder yielded the best results, with compressive strength gains of up to 46% and reductions in electrical resistivity exceeding 97%. The eco-efficiency indices (Bi and Bs) confirm that hybrid optimisation strategies significantly reduce cement demand while enhancing the overall performance of ECCC. This strategy represents a viable alternative to produce high-performance and eco-efficient ECCC suitable for applications in smart infrastructure.Este estudo avalia os efeitos sinérgicos da fibra de carbono e do filer calcário nas propriedades de compósitos cimentícios condutivos (CCC), considerando o estado fresco, endurecido, condutividade elétrica, ecoeficiência e microestrutura. Um planejamento experimental com oito composições foi adotado variando o teor de fibra de carbono (0,00%; 0,50% e 1,00% em massa) e a substituição do cimento por filer calcário (0,00%; 10,00% e 20,00% em massa). As propriedades investigadas englobam consistência, resistências à compressão e à tração na flexão, módulo de elasticidade, absorção de água, resistividade elétrica e análise microestrutural por microscopia eletrônica de varredura. Um modelo por regressão polinomial foi utilizado para avaliar a significância dos efeitos principais e suas interações. A combinação de 0,5% de fibra de carbono e 10–20% de filer calcário obteve os melhores resultados, com ganhos de até 46% na resistência à compressão e redução superior a 97% na resistividade elétrica. Os índices de ecoeficiência (Bi e Bs) confirmam que estratégias híbridas de otimização reduzem significativamente a demanda por cimento, ao mesmo tempo em que aprimoram o desempenho dos CCC. Essa estratégia representa uma alternativa viável para a produção de CCC de alto desempenho e ecoeficientes, adequados para aplicações em infraestruturas inteligentes.</p
Public narrative leadership in community sport: enabling social change in health and wellbeing through storytelling, relationship building and collective action
No full textThis paper examines public narrative leadership in mobilising and empowering local leaders for increasing participation in community sport and physical activity for health in Southall, London UK. Public narrative strengthens local leadership for social change through storytelling, relationship building and collective action. 3 years of collaborative and participatory research included 27 semi- structured interviews with community leaders. Interviews explored experiences of becoming a local leader and the complexities of engaging with public narrative leadership. Three themes characterise public narrative leadership in Southall; (i) authoring and sharing stories: transforming people, place and health, (ii) empathetic leadership through relational authenticity, (iii) story-informed collaborative governance for public health through community sport and physical activity. The study provides a unique community perspective from a long-term research partnership. The collaborative research is building evidence about public narrative leadership as a form of collaborative action and governance for increasing physical activity, improving health and bringing about positive change to the lives of individuals and communities.</p
Demonstration of Energy Efficiency Potential (DEEP) report 2: Case studies summary
No full textThe DEEP case study retrofits provide compelling evidence on how a whole house approach to retrofit can reduce heat loss, surface condensation risk and overheating risks in solid walled homes. From the data collected, specific guidance is produced outlining how to install retrofits in solid walled homes more safely and effectively. Recommendations are provided on how to make measurements and modelling predictions of the technical performance of retrofits more accurate. The findings can inform evidence-led decisions at multiple levels to ensure retrofits in solid walled homes are safe and effective.© Crown Copyright</p
Investigating Questions Driven Reading of Mathematics Data Sets
No full textData sets used for investigating how questions rated by experts as highly procedural or conceptual affect relevance appreciation of mathematical text while reading towards answering these questions. To examine this, we focus on text sections and questions presenting and explaining the definitions of parity and periodicity of real functions. We utilise scores yielded from comparatively judging text sections on their relevance to a given question. The full information about the study and the results appear in our corresponding paper.© the author</p
Traffic simulation datasets supporting a Digital Twin of Milos Island road network
No full textThis dataset contains traffic simulation inputs and outputs used to develop and validate a Digital Twin of the road network of Milos Island, Greece. The data support scenario testing of congestion mitigation and sustainability interventions using SUMO, including traffic counts, synthetic demand, route files, and simulation-derived performance indicators such as travel time loss, fuel consumption, and CO₂ emissions© the author</p
Enabling power and data transfer for medical implants using ultrasound
No full textBiomedical implants are witnessing a rapid development in recent decades. With a demand for more functions comes the need for a more stable and more plentiful supply of energy. Methods of delivering that energy such as power storage and energy harvesting both have their limitations: Energy storage can only provide a finite amount of energy, while existing energy harvesters cannot deliver enough power for a sensing device with computing power and wireless communication. Wireless power transfer mechanisms have been explored in previous works to fill this gap, including electromagnetic, optical, and ultrasonic power transfer. Ultrasonic power transfer uses mechanical waves to deliver energy, which has the benefit of penetrating deep into electrically conductive materials, while requiring a relatively small transducer compared to antennae used for electromagnetic waves. One problem of ultrasonic power transfer is the conflict between efficiency and the angle of ultrasound emission. Previous works have used both omnidirectional transducers and focused ultrasonic probes; the former is less susceptible to misalignment, but with overall lower efficiency; the latter has higher efficiency when aligned properly, but will struggle to deliver power when misaligned. To solve the problem of misalignment, a method which helps the power transfer system to adapt to misalignment while maintaining efficiency is required. This thesis proposes a novel concept of a synergetic implant-wearable system. The wearable can deliver power to the implant, while the implant performs data sampling, and the data can be then relayed to the outside world through the wearable using ultrasound. Ex-vivo experiments were performed for validation. A piezoelectric phased array which can transmit and receive ultrasound was designed and fabricated. New combinations of theoretical models were implemented to help characterise and optimise the phased array. An FPGA-based beamformer was designed and built in order to generate high voltage phased-shifted square waves to drive the piezoelectric transducers. Simulations were performed to test the beamforming algorithm. In the experiments, the phased array was successfully driven by the beamformer and transmitted energy from the phased array to a piezoelectric chip transducer at the receiver. The energy delivered by ultrasound successfully powered a modern microcontroller performing data sampling, computing, and transmitting data back to the phased array using the same piezoelectric transducer, which indicated a significant increase in total power compared to previous works. On the receiver side, a novel method which uses a Cockcroft-Walton voltage multiplier to rectify and up-convert the voltage coming from the piezoelectric transducer was tested. The system showed high reliability and have completely avoided cold start problems, which can be problematic for a system of this type. A novel position feedback algorithm was developed: by knowing the time-of-flight (ToF) of ultrasound from the implant to at least three phased array elements, their relative position can be geometrically solved. A precise time reference can be obtained through electromagnetic coupling between the two circuits upon actuation at high power. The ToF was calculated using the time delay of the pulse arriving at different transducers. The pulse detection algorithm was optimised to consist of a simple convolution operation and was successfully executed on a microcontroller, which proved the viability of performing these tasks on a mobile device. Bidirectional data transfer was achieved by implementing on-off-keying (OOK) on both the phased array and the chip transducer. Data downlink was tested successfully by applying OOK to the whole phased array. In order to reduce the power consumption on the implant for data uplink, passive beamforming was performed to the incoming signal of the phased array, which is a novel integration to such a system. This method significantly increased the signal-to-noise ratio of the data uplink signal.</p
Structured reasoning with large language models for few-shot herbarium image classification
No full textHerbarium image classification is challenging due to many factors, including limited sample sizes, the high diversity of plant morphologies, and variations in specimen placement. This paper explores the use of large language models (LLMs) to achieve high-accuracy herbarium image classification in few shot learning settings. A Cyrtandra dataset is constructed, and standard deep-learning baselines are evaluated as benchmarks. We consider a direct, end-to-end method and a structured, two stage method. The evaluation controls for order effects and visible text by shuffling presentation and using plant-only and name masked variants, and also varies the test images to diagnose which cues drive decisions; prompt ensembling is used to stabilise predictions. Findings indicate that the direct route largely exploits textual information on the sheet, whereas the structured route remains robust when such cues are limited and scales more reliably as the label space expands. This paper also discusses the limitations of current LLMs, such as high-accuracy image based LLMs requiring many tokens, which prevents their use in classification tasks involving a large number of classes. Future work includes exploring ways to compress training data to reduce token requirements and improve the classification of a larger number of classes.</p
Foreword to the special issue “Data envelopment analysis: novel models and methodologies for efficiency and performance assessment of public organizations”
No full textForeword to the Special Issue “Data envelopment analysis: Novel models and methodologies for efficiency and performance assessment of public organizations”Data envelopment analysis (DEA) is a rapidly developing area devoted to the evaluation of efficiency and productivity of organiza?tions. The methodology of DEA includes various models and approaches that span the areas of operational research (especially optimization), management science, economics, mathematics and statistics, with ap?plications found in most public and private sectors (cont.)</p
‘Saint or Politician?’: Mohandas Gandhi, Indian independence, and the British anarchist movement
No full textM.K. Gandhi’s obituarist in the British anarchist newspaper Freedom faced a problem. How best to assess the legacy of a figure who had proved a source of inspiration for some anarchists, and, at the same time, frustration and hostility for others? Pen poised, the solution that presented itself was to embrace the ambivalence. Adopting the title ‘Saint or Politician?’, the writer described Gandhi as a man of pervading ambiguities. He was both a ‘shrewd political tactician’ and a ‘simple saint-like mystic’; a ‘barrister and […] advocate of law-breaking’; an opponent of industrialism, who nevertheless lived ‘for years in the house of Birla, one of India’s leading industrialists’; a critic of Western materialism, armed always with a mass-produced fountain pen and an American watch. Amid all the uncertainties surrounding India’s future in 1948, one thing was sure: the ‘forces set in motion by this enigmatic man have an unpredictable and conflicting destiny before them.’ Moreover, as with any prophet, the messages that had flowed from that fountain pen would offer no ready solution to the enigma. Instead, ‘his name and memory will be invoked by opposing and mutually hostile causes’. He was, and would be, ‘all things to all men’.1</p
Fuel poverty risk at the end of life needs urgent attention
No full textProactive policy and economic support are needed to reduce fuel poverty risk at the end of life, argues Elaine Robinson.</p