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On the Negative Imaginary Time-Delay Systems With Its Application to Flexible Systems Control
No full textAbstract A new lemma is proposed to determine the negative imaginary (NI) properties of time-delay systems of retarded and neutral types. The lemma is employed for stability analysis in the context of positive feedback interconnection of infinite-mode NI systems and time-delay systems. A cantilever beam with a collocated piezoelectric sensor and actuator pair is studied as an infinite-mode NI system. A novel time-delay controller is proposed to be used within positive position feedback (PPF) and parametrized based on H∞-norm optimization targeting the vibration suppression of the flexible beam. The proposed lemma demonstrates that the designed controller is NI. We also present a corollary to ensure the stability of the closed-loop beam system with the proposed controller using Lyapunov and dissipation based stability approaches. The theoretical results are further verified by simulations. Moreover, the efficacy of the controller is evaluated against a state-of-the-art controller for vibration suppression. Simulation results show that the proposed controller achieves better performance in suppressing vibrations without significant change in robustness.https://doi.org/10.1115/1.406836
Enhancing the Mechanical Performance of Fused Deposition Modeling-Printed Recycled Polypropylene through Annealing Temperature, Duration, and Cooling Method
No full texthttps://doi.org/10.1007/s11665-025-11539-
A Historical View of Active Assisted Living
No full textAbstract Active assisted living (AAL) aims to use innovative technologies to create supportive, inclusive, and empowering applications and environments that enable older, impaired or frail people to live independently and stay active longer in society. This chapter provides an introduction to the main concepts of AAL, provides a brief history of the evolution of such technologies, and gives a functional view of how AAL system architecture can be conceptualized. It then provides a taxonomy of AAL technologies and applications, followed by technological underpinnings of audio- and video- based AAL.https://doi.org/10.1007/978-3-031-84158-3_1https://research-portal.uu.nl/en/publications/932bc758-e243-4cfa-bc94-e1af73a8bcf
Design and Analysis of Flow Channels in Reverse Osmosis Systems: A Preliminary Study
No full texthttps://doi.org/10.1109/ichora65333.2025.1101718
Thermal Performance of Silica-Coated Wood Particles
No full textWood is one of the most widely used sustainable lignocellulosic materials, with numerous applications in consumer goods and the construction sector. Despite its positive properties, such as a high strength-to-weight ratio, thermal insulation, and low density, wood’s natural thermal degradation can limit its potential applications. In composite applications like wood–plastic composites, the particle morphology and surface topography must be preserved to support intimate polymer–wood contact and mechanical interlocking. This study investigated the efficacy of a thin silica coating for thermal protection, which was applied via an in situ sol–gel method using the precursor tetraethoxysilane (TEOS). The wood particles and treatments were characterized using particle size analysis, physisorption, FTIR, SEM, XRD, and TGA analyses. After treatment, the specific and microporous surface area of wood particles increased by 118% and 97%, respectively, an effect of the porosity of silica itself. FTIR spectra of the silica-treated wood displayed peaks corresponding to Si stretching, and SEM micrographs confirmed a successful silica coating formation. TGA showed that the silica coating increased the temperatures needed to degrade the underlying hemicellulose and cellulose by 16 °C for all treatment levels. This particle-scale coating provided a promising method for producing thermally protected, functionalizable wood fillers for composites that maintain the filler geometry and potential mechanical interlocking, offering an attractive upcycling pathway for wood residues.https://doi.org/10.3390/jcs910055
Meta-Heuristic Based Design and Optimization of Double Stator-Single Rotor Axial-Flux Induction Generator
No full texthttps://doi.org/10.1109/iemdc60492.2025.1106098
Fabrication of electrospun graphene-oxide embedded polyacrylonitrile composite nanofibers for air filtration
No full textIn this study, polyacrylonitrile-graphene oxide (PAN/GO) nanofiber composite nanofibers were prepared with varying GO ratios between 0.1 and 0.5 wt% by electrospinning technique. The fiber diameter of bare PAN was increased from 184 ± 40 nm to 314.5 ± 20.42 nm with the rise of GO ratio to 0.5 wt%. Accordingly, an improvement in the mechanical strength of bare PAN nanofibers was also observed. While the modulus of elasticity value for bare PAN nanofiber was calculated as 1.75 ± 0.2 MPa, this value was found to be 6.55 ± 0.13 MPa when the GO ratio was 0.5 wt%. Similarly, tensile strength of bare PAN nanofiber increased from 0.377 to 0.550 MPa and yield strength from 0.17 to 0.35 MPa at 0.5 wt% GO ratio. When water vapor transmission values of nanofibers were calculated, it was found that with the increase of GO ratio, the nanofibers became more hydrophilic and water vapor was adsorbed more on the filter surface, resulting in a decrease in water vapor transmission values down to 176.70 g/m2h. The PAN-GO nanofibers are promising candidates for the air filter materials due to their excellent mechanical properties, low cost and non-toxicity.https://doi.org/10.1080/10601325.2025.2477088https://hdl.handle.net/20.500.12960/176
Dopant‐Driven Metal Ion Response in Carbon Dots: The Role of Excitation Wavelength in Selective Sensing and Potential Design of an Eco‐Friendly ATP Sensor
No full textAbstract In this study, nitrogen‐ and boron‐doped carbon dots (CDs) were synthesized via a microwave‐assisted method and evaluated for metal ion sensing and ATP detection. The work investigated how surface and core states influence photophysical behavior and selective quenching. FTIR confirmed distinct carboxyl, amine, and hydroxyl surface functionalities for each CD variant. Spectroscopic analysis revealed excitation‐dependent emissions, linking specific radiative transitions to functional groups and core states. Notably, Cu 2 ⁺ quenched 80% of fluorescence primarily at shorter excitation wavelengths (300 nm), indicating strong surface‐state interactions, while Ag⁺ induced 65% quenching at longer wavelengths (450 nm) through core‐state interactions. Boron‐doped CDs displayed at least a 20‐fold fluorescence enhancement upon exposure to Mg 2 ⁺, Zn 2 ⁺, and Cd 2 ⁺ at 300 nm, attributed to surface passivation. In ATP sensing assays, the CDs’ high sensitivity to Cu 2 ⁺ and ATP's affinity for copper ions enabled detection via absorption and fluorescence spectroscopy. These results demonstrate that tuning excitation wavelength modulates sensor selectivity, showing doped CDs as cost‐effective, eco‐friendly platforms for wavelength‐specific ion and biomolecule detection. The combined quenching and enhancement behaviors emphasize the critical role of surface and core state engineering in achieving wavelength‐specific responses. This study provides a foundation for developing low‐cost, environmentally friendly sensors based on doped CDs with tunable selectivity.https://doi.org/10.1002/slct.20250351
Enhancing Hyperspectral and Multispectral Image Fusion Using High Dimensional Model Representation
No full texthttps://doi.org/10.1109/isas66241.2025.1110175
Relativistic oscillators in the context of energy-dependent noncommutative phase space
No full texthttps://doi.org/10.1007/s00601-025-01998-