20505 research outputs found
Sort by
An ultra-thin and lightweight flexible actuator for digitally-controllable shape-morphing haptics
No full textWith the growing demand for wearable electronics, efficient haptic systems are essential for contact perception and variable haptic feedback. However, achieving a large shape-morphing haptic output is still a challenge for existing flexible robotic actuators. This paper presents a digitally-controllable, ultralight (65mg), ultrathin (260 μm) flexible actuator that delivers large shape-morphing haptic feedback with an output force of 240 mN and a displacement of 0.88mm. By integration of micro-circuit printing and micro-fluidic manufacturing technologies, the actuator with significant lightweight and thinness is created. Despite excellent flexibility, the actuator is still able to generate powerful haptic output. User experiments with a haptic signal recognition accuracy of 91.33% validate its potential in wearable devices and human-machine interfaces. Additionally, immersive virtual reality experiments confirmed its ability to recreate realistic tactile sensations, such as perceiving continuous water flow and catching a fast-moving object, highlighting its applicability in embodied intelligence, virtual reality, motion training, and interactive experiences. This study offers new design insights for haptic interfaces in virtual and augmented reality and lays the foundation for future skin-patch-based haptic devices.This work was supported by the Frontier Technologies R&D Program of Jiangsu (BF2024047), the Major Program of NSFC for Basic Theory and Key Technology of Tri-Co Robots (92248301), the Major Key Projects of PCL under Grants (PCL2025A12–2, PCL2024A04–1), the Guangdong S&T Program under Grant (2024B0101010003), and the Postgraduate Research & Practice Innovation Program of Jiangsu Province (KYCX22_3617).Sensors and Actuators A: Physica
Does container-based sanitation align with sanitation sectoral planning in Lima?
No full textThe paper explores the potential of Container-Based Sanitation (CBS) as an off-grid sanitation option in addressing extreme sanitation inequalities in informal urban settlements in Lima, Perú. It achieves this by evaluating the conflicting and political tensions within the formal and informal structures of state public service provision in Lima using qualitative data collected through semi-structured interviews with government officials, third-sector organizations, citizens of informal urban settlements, and academia. The paper argues that although the CBS provision has high social acceptability among its users within Lima's informal settlements, the state of Lima's fragmented sanitation sector regime hinders the possibility of scaling sanitation innovations. In Lima, scaling up CBS among informal settlements remains challenging as conventional sewerage is prioritised in WASH policy discourse and implementation. Even for CBS users, the technology was seen as a stopgap solution until they finally access sewered sanitation provided by the state, mainly because of the state's inability to fully address wastewater challenges and the assumption that conventional sewerage will eventually arrive.This work occurred under the ‘Scaling-up Off-grid Sanitation’ project (SOS; ES/T007877/1), funded by the United Kingdom's Global Challenge Research Fund via the Economic and Social Research Council.Journal of Water, Sanitation and Hygiene for Developmen
Enhancing pest detection in deep learning through a systematic image quality assessment and preprocessing framework
No full textThe original image data presented in this study are openly available in the IP102 dataset at https://www.kaggle.com/datasets/rtlmhjbn/ip02-dataset (accessed on 20 July 2025).This study addresses the critical challenge of variable image quality in deep learning-based automated pest identification. We propose a holistic pipeline that integrates systematic Image Quality Assessment (IQA) with tailored preprocessing to enhance the performance of a YOLOv5 object detection model. The methodology begins with a No-Reference IQA using BRISQUE, PIQE, and NIQE metrics to quantitatively diagnose image clarity, noise, and distortion. Based on this assessment, a tailored preprocessing stage employing six different filters (Wiener, Lucy–Richardson, etc.) is applied to rectify degradations. Enhanced images are then used to train a YOLOv5 model for detecting four common pest species. Experimental results demonstrate that our IQA-anchored pipeline significantly improves image quality, with average BRISQUE and PIQE scores reducing from 40.78 to 25.42 and 34.94 to 30.38, respectively. Consequently, the detection confidence for challenging pests increased, for instance, from 0.27 to 0.44 for Peach Borer after dataset enhancement. This work concludes that a methodical approach to image quality management is not an optional step but a critical prerequisite that directly dictates the performance ceiling of automated deep learning systems in agriculture, offering a reusable blueprint for robust visual recognition tasks.Journal of Experimental and Theoretical Analyse
Development and evaluation of kraft pulp-banana fibre-reinforced cement composites as a sustainable alternative to asbestos cement boards in Africa
No full textMany developing countries, particularly in Africa, still rely on carcinogenic asbestos fibres for producing cement boards used in roofing and cladding. This research focuses on creating a sustainable, affordable, and locally available alternative to asbestos. A specialised laboratory technique, designed to mimic industrial asbestos-cement board production, was used to develop kraft pulp–banana fibre reinforced cement composite boards. Their mechanical, durability, and morphological properties were tested after curing in a humidity chamber. Findings showed that boards made with 10 wt.% kraft pulp and 6 wt.% banana fibres achieved the best performance, with a flexural strength of 14.31 MPa and a deflection of 2.15 mm. Physical and morphological assessments confirmed that lightweight boards with strong fibre-matrix bonding can be achieved using kraft and banana fibres. The results also demonstrate that these hybrid fibre-reinforced cement boards meet relevant standards such as BS EN 12467, indicating that they are a safe and effective potential replacement for asbestos-based products.Advances in Materials and Processing Technologie
The combustion continuum and munition reactions: practical implications for army engineers
No full textArmy engineers are often tasked with the most complex and dangerous aspects of explosive ordnance disposal (EOD), range clearance, and battlefield recovery. In these contexts, the clarity of terminology is not an academic nicety but an operational necessity. Ambiguity in describing explosive phenomena has historically led to inconsistent reporting, miscommunication between services, and avoidable risks in planning.
The Combustion Continuum, developed through recent research at Cranfield and applied in both academic and operational domains, provides a unified framework for understanding energetic reactions. By explicitly defining burning, deflagration, and detonation as points on a continuum, and tying transition points to observable shock phenomena, the model eliminates much of the long-standing confusion in the field. Extending the model to munition outcomes – distinguishing between low-order and high-order events – allows army engineers to consistently categorize and interpret EOD results.
This article sets out the continuum in detail, explains its application to munitions, and explores its implications for doctrine, training, and operational reporting. For Royal Engineers, this framework offers an evidence-based lexicon that can be embedded in field manuals, JSPs, and post-action analysis to improve safety, interoperability, and institutional learning.Royal Engineers Journa
Damage tolerance of double lap joins under transverse impact
No full textLow velocity impact on adhesive joints represents a worst-case scenario in a bonded structure, so their residual tensile strength is a crucial indicator for damage tolerance of the bonded structures. In this study, narrow double lap joints were tested under two transverse impact energy levels to provide a conservative assessment of damage tolerance. Residual tensile tests were conducted after impact, showing a 49% reduction of pristine joint strength after a 2J impact, and a further reduction (57% of pristine joint strength) post a 3J impact. Residual tensile strength of impacted double lap joints was found to correlate to that of the joints with a similar artificial defect length and location near the inner adherend. The failure mechanisms in the double lap joints were explained via X-ray computed tomography and high-speed photography. 2D FE models were developed using surface interactions based on a virtual crack closure technique in ABAQUS Standard. The FE models capture the residual tensile strength reduction trend, confirming the underlying mixed-mode fracture-controlled failure mode influenced by the asymmetrical damage and loading.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by Mitsubishi Heavy Industries LTDJournal of Composite Material
Numerical study of coupling between multiphase flow-induced vibrations (mfiv) and vortex-induced vibrations (viv) of slender flexible pipes.
Get PDFThe dynamic response of a riser subjected to external and internal flow-induced
vibration is studied numerically through the coupling of a computational fluid
dynamics (CFD) solver and a finite element (FE) solver. This thesis describes the
vortex-induced vibration (VIV) of elastically mounted rigid cylinders, empty
flexible risers and fluid conveying risers using three-dimensional (3D) numerical
simulations. The dynamic characteristics of the riser, such as inline (IL) and
crossflow (CF) displacements and vibrating frequencies, are provided and
discussed. The effects of fluid flow, including velocity magnitude and profile, on
the dynamic response are also investigated.
A 1 degree of freedom (1DOF) VIV of an elastic cylinder is studied first using 2D
and 3D numerical models. The effects of mass and damping ratio on the
amplitude of vibration of the cylinder over a reduced velocity range are analysed.
Results show a good agreement with published experimental studies. It is
demonstrated that increasing the mass and damping ratio reduces the maximum
vibration amplitude of the cylinder.
A 3D numerical study is then carried out to investigate the effects of velocity
magnitude, velocity profile, the elastic modulus of the riser, orientation, and
aspect ratio. The study establishes that the IL displacement, CF vibration mode,
and frequencies increase with the flow velocity, aspect ratio and reduction of
elastic modulus.
In addition, the VIV of the riser transporting single-phase internal flow is
presented. The numerical study describes the effects of internal flow velocity
magnitude on the dynamic response of the riser. It is shown that the internal flow
velocity magnitude affects the vibration mode of the riser.
Finally, the effects of internal air-water volume fractions on the dynamic response
of a riser transporting a two-phase flow are examined in detail. The influence of
gas fraction on a pipe with no external flow, on a jumper pipe with no external
flow and on a fluid conveying pipe exposed to external flow is investigated. The
numerical results show that a variation of the air volume fraction slightly affects
the dynamic characteristics of the riser.PhD in Energy and Powe
Stereographic projection of probabilistic frequency-domain uncertainty
Get PDFThis paper investigates the stereographic projection of points along the Nyquist plots of single input single output (SISO) linear time invariant (LTI) systems subject to probabilistic uncertainty. At each frequency, there corresponds a complex-valued random variable with given probability distribution in the complex plane. The chordal distance between the stereographic projections of this complex value and the corresponding value for a nominal model, as per the well-known ν-Gap metric of Vinnicombe, is also a random quantity. The main result provides the cumulative density function (CDF) of the chordal distance at a given frequency. Such a stochastic distance framework opens up a fresh and a fertile research direction on probabilistic robust control theory.This research project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program under grant agreement No 834142 (Scalable Control).2024 IEEE 63rd Conference on Decision and Control (CDC
A cognitive-based ISAR system for spectral compatibility applications
Get PDFThis paper proposes and analyzes the concept of a cognitive inverse synthetic aperture radar (ISAR) ensuring spectral compatibility in crowded electromagnetic environments. In such a context, cognitive radar system alternates between a perception stage, recognizing possible emitters in its frequency range, and an action stage, synthesizing and transmitting a tailored radar waveform to achieve the desired task while guaranteeing the spectral coexistence with overlaid emitters. The perception stage is carried out by an electronic support measurement system (ESM) that senses the environment and extracts relevant spectral parameters. The action stage employs a tailored signal design process, synthesizing a radar waveform with bespoke spectral notches, enabling ISAR imaging over a wide spectral bandwidth without interfering with the other radio frequency (RF) systems. A key enabling technology for the proposed application is the compressed sensing (CS) framework, allowing accurate ISAR imaging even with missing data in the frequency domain (induced by spectral notches) and in the slow-time dimension (enabling the system to perform additional RF activities). The capabilities of the proposed system are assessed exploiting a dataset of drone measurements in the frequency band [13, 15] GHz. The results highlight the effectiveness of the proposed system to enable the spectral compatibility while delivering high-quality ISAR images.European CommissionThe work of Augusto Aubry, Antonio De Maio, and Massimo Rosamilia was partially supported by the European Union under the Italian National Recovery and Resilience Plan (NRRP) of NextGenerationEU, partnership on “Telecommunications of the Future” (PE00000001 - program “RESTART”).2024 IEEE International Workshop on Technologies for Defense and Security (TechDefense
The Didcot Demolition
Get PDFIn the modern world of demolition safety is paramount and unnecessary or unquantifiable risks are not accepted (FasterCapital, 2024) and all risks must be kept As Low As Reasonably Practicable (ALARP) (BSI, 2017). This principle has led to a huge reduction in deaths in the last 50 years and the statistics continue to improve although this is starting to plateau (Beal, 2007). Under normal circumstances, this is now simply part of the normal way work is done and systems are in place to ensure both safety and economic profits are assured. What happens when the environment is less controlled and risks are unknown, such as after a natural disaster, war, an accident or a stand-up from a failed demolition attempt? A dangerous structure cannot responsibly be left alone with a fence around it so some action must be taken, but how can this be done safely and responsibly? An incident in Didcot, England in which half of a power station’s boiler house being prepared for an explosive demolition collapsed suddenly, killing four men in 2016 provides a useful case study of how technology, creativity and planning can be used to conduct complex demolition fully remotely to avoid any further risk to life.ISEE 51st Annual Conference on Explosives and Blasting Techniqu