Search Results (477)

Managing complex and large-scale building facilities requires reliable, easily interpretable, and computationally efficient models. Considering the electrical-circuit analogy, lumped-parameter resistance–capacitance (RC) thermal models have emerged as both simulation surrogates and advanced tools for energy management. This review synthesizes recent uses of RC models for building energy management in large facilities and aggregates. A systematic review of the most recent international literature, based on the analysis of 70 peer-reviewed articles, led to the classification of three main areas: (i) the physics and modeling potential of RC models; (ii) the methods for automation, calibration, and scalability; and (iii) applications in model predictive control (MPC), energy flexibility, and digital twins (DTs). The results show that these models achieve an efficient balance between accuracy and simplicity, allowing for real-time deployment in embedded control systems and building-automation platforms. In complex and large-scale situations, a growing integration with machine learning (ML) techniques, semantic frameworks, and stochastic methods within virtual environments is evident. Nonetheless, challenges persist regarding the standardization of performance metrics, input data quality, and real-scale validation. This review provides essential and up-to-date guidance for developing interoperable solutions for complex building energy systems, supporting integrated management across district, urban, and community levels for the future. Full article

To meet the demand for online monitoring of acetylene (C₂H₂) in transformer oil, a high-sensitivity detection system based on photoacoustic spectroscopy (PAS) is presented. The system integrates custom-designed modules for signal acquisition, phase-sensitive detection, and data processing, centered around a high-performance microcontroller. A full-wave lock-in amplification-based phase-sensitive detection circuit enables precise extraction of nV-level photoacoustic signals. Finite element simulations of the resonant photoacoustic cell in COMSOL 6.2 were conducted to optimize the structural configuration and sensor placement, achieving maximum acoustic response. Calibration experiments confirmed excellent system performance, demonstrating a linear response (R² > 0.99) over the 0.5–20 ppm range and a practical detection limit of 0.1 ppm. Comparative evaluations against conventional dissolved gas analysis (DGA) equipment verify the system’s sensitivity, stability, and temporal resolution, demonstrating its potential as a high-sensitivity and reliable solution for transformer fault gas diagnostics. Full article

Accurate real-time dosimetry is key in megavoltage radiotherapy; however, many detectors require external biasing or complex instrumentation. This study evaluated thin-film CdTe solar cells operating in photovoltaic (zero-bias) mode as medical dosimeters. Superstrate ITO/CdS/CdTe/Cu/Au devices were fabricated and irradiated with 6-MV photons from a clinical linear accelerator to 20 kGy cumulative dose. Electrical and dosimetric properties were assessed based on AM 1.5 current–voltage measurements, external quantum efficiency (EQE), dose linearity, dose-rate dependence, field-size dependence, percentage depth dose (PDD), and one-month reproducibility. With increasing dose (5–20 kGy), the open-circuit voltage and fill factor decreased by ~2–3%, the short-circuit current density by ~10%, retaining ~87% initial efficiency. Series and shunt resistances were stable, while EQE decreased uniformly (~5%), indicating degradation mainly from increased nonradiative recombination. Dose–signal linearity remained intact, and post-irradiation sensitivity loss was corrected with a single calibration factor. Dose-rate dependence was minor; low reverse bias (~3–7 V) enhanced response without nonlinearity. Field-size and PDD responses agreed with ionization chamber data within ~1%, and weekly stability was within ~1%. Parallel stacking of two cells increased signal nearly linearly. CdTe solar-cell detectors thus enable zero-bias, real-time, stable, and scalable dosimetry and strongly agree with reference standards. Full article

Detecting fine, weak-textured defects with discontinuous boundaries on complex industrial surfaces is challenging due to interference from background textures and characters, as well as the scarcity of labeled data. To address this issue, we propose YOLO-SR, an engineering modification of YOLO11 tailored to defect segmentation on smart-card surfaces. Rather than introducing a new detection architecture, YOLO-SR reuses the backbone–neck–head design of YOLO11 and only adjusts a few modules to better capture elongated, low-contrast defects. The approach comprises two key components: first, embedding Strip Pooling (SP) within the C3K2 module to form C3K2_SP; second, a Rectangular Self-Calibration Module (RCM) is interposed after the top-level semantic layer. RCM generates rectangular gates to spatially recalibrate local responses, suppressing interference from complex textures and characters. To mitigate data scarcity and distributional bias, a texture-adaptive procedural defect synthesis strategy was developed. This strategy generates defect samples that conform to the background texture statistics of high-quality backgrounds. Experiments on the integrated circuit chip (ICChip) and signature plate (SignPlate) datasets show that YOLO-SR outperforms the YOLO11 baseline. Results indicate that SP and RCM complement each other by integrating directional priors from mid-to-high layers with top-level shape self-calibration. This enhances the visibility and localization stability of elongated defects while maintaining efficient inference. Full article

In scenarios involving radiation such as decommissioning of nuclear disasters and operating nuclear power plants, it is necessary to perform tasks including maintenance, demolition, and inspection using robots in order to protect human workers from harm. LIDAR (LIght Detection And Ranging) sensors are used for many demanding real-time tasks in robotics such as obstacle avoidance, localisation, mapping, and navigation. Standard silicon-based electronics including LIDAR fail quickly in gamma radiation, however, high-radiation areas have a critical need for robotic maintenance to keep people safe. Sensors need to be developed, which can cope with this environment. A prototype including most required transmitter and receiver circuits is designed utilising components expected to provide up to (1 MGy) gamma radiation tolerance. Initial results testing the concepts of the laser transmission and detection in a lab environment shows reliable signal detection. Performance tests utilising multiple receivers show a linear relationship between receiver separation and measured time difference, allowing for the possibility of calibration of a sensor using the time difference between pulses. Future work (such as radiation testing trials) is discussed and defined. These results contribute to de-risking the feasibility of long-term deployment of LIDAR systems utilising these approaches into environments with high gamma dose rates, such as nuclear fission decommissioning, big science facilities such as the Large Hadron Collider, and remote maintenance systems used in future nuclear fusion power plants such as STEP and EU-DEMO. Full article

New intensified flotation technologies have emerged to enhance fine and ultrafine particle recovery. However, their modelling remains challenging, as it requires defining the effective collection volume, residence time, and internal recirculation, factors not included in conventional models, while also facing operational complexity and the limited availability of key hydrodynamic and kinetic data. This study presents the development of a flotation model for the Concorde Cell technology, which separates the flotation process into three stages: collection zone, separation tank, and froth transport. The collection zone was represented as a plug-flow reactor with a rectangular rate of constant distribution; the separation zone as a perfect mixer with a detachment efficiency factor; and the froth recovery as a function of froth stability, residence time, and transport distance. Water recovery and gangue entrainment were also modelled to estimate concentrate grades. The model was tested and calibrated using experimental results from tests conducted in a Concorde Cell Lab Unit. A case example is presented for a semi-batch exhausting test performed with minerals from a copper concentrator plant. Good agreement between simulated and experimental results demonstrated the robustness and flexibility of the model. Additionally, the results showed collection rate constants significantly higher than those typically reported for conventional flotation cells (more than 100 times higher for Cu), due to the smaller collection volume and shorter residence time in the Concorde Cell. The calibrated model was then applied to simulate an industrial operation, where sensitivity analyses showed consistent responses to variations in operating conditions. Overall, the proposed model provides a practical tool for predicting the metallurgical performance of intensified flotation cells, supporting the integration of this new technology into modern concentrator flowsheets for the development of hybrid circuits. Full article

Pseudo-entropy is a complex-valued generalization of entanglement entropy defined on non-Hermitian transition operators and induced by post-selection. We present a simulation-based protocol for detecting nonclassicality and coherent errors in quantum circuits using this pseudo-entropy measure $\check{S}$, focusing on its imaginary part $\Im \check{S}$ as a diagnostic tool. Our method enables resource-efficient classification of phase-coherent errors, such as those from miscalibrated CNOT gates, even under realistic noise conditions. By quantifying the transition between classical-like and quantum-like behavior through threshold analysis, we provide theoretical benchmarks for error classification that can inform hardware calibration strategies. Numerical simulations demonstrate that 55% of the parameter space remains classified as classical-like (below classification thresholds) at hardware-calibrated sensitivity levels, with statistical significance confirmed through rigorous sensitivity analysis. Robustness to noise and comparison with standard entropy-based methods are demonstrated in a simulation. While hardware validation remains necessary, this work bridges theoretical concepts of nonclassicality with practical quantum error classification frameworks, providing a foundation for experimental quantum computing applications. Full article

The General AntiParticle Spectrometer is a balloon-borne experiment designed to search for low-energy cosmic-ray antinuclei as a potential indirect signature of dark matter. Over the course of at least three long-duration flights over Antarctica, it will explore the sub-$250 \mathrm{M}\mathrm{e}\mathrm{V}/\mathit{n}$ energy range with sensitivity to antideuterons and antihelium, while also extending antiproton measurements below 100 $\mathrm{M}$$\mathrm{e}\mathrm{V}$. The instrument features a tracker built from more than one thousand lithium-drifted silicon detectors, each read out by a dedicated custom integrated circuit. With the first flight scheduled for the austral summer of 2025, a new prototype chip, ANTARES4, has been developed using a commercial 65 $\mathrm{n}$$\mathrm{m}$ complementary metal-oxide semiconductor process for use in the second flight. It integrates eight independent analog channels, each incorporating a low-noise charge-sensitive amplifier with dynamic signal compression, a CR–RC shaping stage with eight selectable peaking times, and on-chip calibration circuitry. The charge-sensitive amplifier uses metal-oxide semiconductor feedback elements with voltage-dependent capacitance to support the wide input energy range from 10 $\mathrm{k}$$\mathrm{e}\mathrm{V}$ to 100 $\mathrm{M}$$\mathrm{e}\mathrm{V}$. Four alternative feedback implementations are included to compare performance and design trade-offs. Leakage current compensation up to 200 $\mathrm{n}$$\mathrm{A}$ per detector strip is provided by a Krummenacher current–feedback network. This paper presents the design and architecture of ANTARES4, highlighting the motivations, design drivers, and performance requirements that guided its development. Full article

The simultaneous detection of multiple cancer biomarkers using microfluidic multiplexed immunosensors is gaining significant interest in the field of Point-of-Care diagnostics. This study highlights integrating surface-enhanced infrared Fourier transform (SE-FTIR) with a plasmonic-active nanostructure thin film (PANTF) on a printed circuit board (PCB), housed within a microfluidic device for rapid, non-destructive detection of breast cancer (BC). Detection uses monoclonal antibody (mAb)-functionalized gold nanourchins (GNUs) on dual sensing regions. A total of 12 serum samples (24 data points) were tested for HER-II and CA 15-3. The system demonstrated a SE-FTIR enhancement factor (EF) of ~0.18 × 10⁵ using Rhodamine 6G (R6G). Calibration with HER-II (1–100 ng/mL) and CA 15-3 (10–100 U/mL) showed linear responses (R² = 0.8 and 0.76, respectively). Measurements of unknowns were performed at 1 µL/min over 68 min, with 43 min for biomarker interaction. SE-FTIR spectra were recorded at active zones and analyzed using SpectraView (SV), a custom Python 3.12-based tool. Data preprocessing included filtering (SciPy’s filtfilt) and baseline correction using the Improved Asymmetric Least Squares (IASLS) algorithm (pybaselines.Whittaker). Fourier cross-correlation (FCC) showed stronger signal consistency for HER-II. Partial Least Squares (PLS) regression, a dimensionality reduction technique, enabled clear discrimination between the samples and types, with classification accuracy reaching 1.0. Cancer staging based on these biomarkers yielded an overall accuracy of 0.54, indicating that classification regardless of biomarker type. Further studies involving larger and more diverse sample sets are critical before any definitive conclusions can be drawn. Full article

Online radiation dose monitoring is critical for the safe operation of accelerators. Although commercial dose monitors are well-developed, integrating an ionization chamber directly within a small-sized Betatron magnet remains challenging. In this study, we designed an air ionization chamber tailored for real-time dose monitoring in a small-sized Betatron. We selected aluminum for the chamber wall based on structural and integration requirements, designed the cavity geometry, and developed the associated charge collection and sampling circuits. Using a standard reference PTW ionization chamber, we calibrated the output voltage of the chamber against X-ray dose rates and conducted stability tests. The results show that there is a very good linear relationship between the output voltage of the ionization chamber and the X-ray dose rate. The relative standard deviation of the dose rate data within a 10 min working cycle is 3.25%, and the dose rate data shows good consistency with the standard reference ionization chamber. The ionization chamber can ensure operational safety for a small-sized Betatron and offer guidance for similar applications. Full article

NISQ (Noisy Intermediate-Scale Quantum) era constraints, high sensitivity to noise and limited qubit count, impose significant barriers on the usability of QPUs (Quantum Process Units) capabilities. To overcome these challenges, researchers are exploring methods to maximize the utility of existing QPUs despite their limitations. Building upon the idea that the execution of a quantum circuit’s shots does not need to be treated as a singular monolithic unit, we propose a methodological framework, termed shot-wise, which enables the distribution of shots for a single circuit across multiple QPUs. Our framework features customizable policies to adapt to various scenarios. Additionally, it introduces a calibration method to pre-evaluate the accuracy and reliability of each QPU’s output before the actual distribution process and an incremental execution mechanism for dynamically managing the shot allocation and policy updates. Such an approach enables flexible and fine-grained management of the distribution process, taking into account various user-defined constraints and (contrasting) objectives. Demonstration results show that shot-wise distribution consistently and significantly improves the execution performance, with no significant drawbacks and additional qualitative advantages. Overall, the shot-wise methodology improves result stability and often outperforms single QPU runs, offering a robust and flexible approach to managing variability in quantum computing. Full article

This study presents the development of a portable DOBI meter prototype designed for the rapid, low-cost evaluation of crude red palm oil (RPO) quality. The device employs two narrow-spectrum LEDs (UV at 269 nm and visible at 446 nm) as light sources, paired with a broadband photodiode (PD) detector to measure light absorption in a quartz cuvette containing 95% hexane-diluted oil samples. Dedicated LED driver circuits, a PD receiver module, and microcontroller-based data acquisition and display systems were integrated into a compact enclosure. Calibration procedures involved the measurement of LED emission spectra and PD responses, followed by standard curve generation using known RPO concentrations. The results from the DOBI meter were validated against a commercial spectrophotometer (Merck Prove 600), demonstrating high accuracy with less than 5% deviation. Further analysis of RPO extracted from microwave-treated mesocarps showed consistent DOBI values and carotenoid concentrations across both instruments. The developed device offers a reliable, accessible alternative for assessing palm oil quality, particularly in field or small-scale industrial settings. Full article

Silicon carbide (SiC) is a key material for electronics operating in harsh environments due to its wide bandgap, high thermal conductivity, and radiation hardness. In this work, we present a SPICE model for a 4H-SiC BJT and TTL inverter exposed to gamma radiation. The devices were fabricated using a dedicated SiC bipolar process at KTH (Sweden) and tested at the ⁶⁰Co Calliope (Italy) facility up to 800 krad _(Si). Experimental data, including Gummel plots and inverter transfer characteristics, were used to calibrate and refine a VBIC-based SPICE model. The adjusted model accounts for both bulk and surface degradation mechanisms by extracting parameters of forward current gain (βF), saturation current (IS), base resistance (RB), and forward transit time (TF). Results show a uniform degradation of BJTs, primarily manifested as reduced current gain and increased base resistance, while the inverter maintained functional operation up to 600 krad_(Si). Extrapolation of the SPICE model predicts a failure threshold near 16 Mrad_(Si), far exceeding the tolerance of conventional silicon circuits. By linking radiation-induced defects at the material and interface levels to circuit-level behavior, the proposed model enables realistic design and lifetime prediction of SiC integrated circuits for satellites, planetary missions, and other radiation-intensive applications. Full article

This study presents a model-driven approach to the design, calibration, and application of frequency-output pressure sensors integrated within an intelligent system for real-time monitoring of rowing performance. The proposed system captures biomechanical parameters of the “boat–rower” complex across 50 parallel channels with a temporal resolution of 8–12 ms. At the core of the sensing architecture are parametric pressure transducers incorporating strain-gauge primary elements and microelectronic auto-generator circuits featuring negative differential resistance (NDR). These oscillating circuits convert mechanical stress into high-frequency output signals in the 1749.9–1751.9 MHz range, with pressure sensitivities from 0.365 kHz/kPa to 1.370 kHz/kPa. The sensor models are derived using physical energy conversion principles, enabling the formulation of analytical expressions for transformation and sensitivity functions. These models simplify sensitivity tuning and allow clear interpretation of how structural and electronic parameters influence output frequency. The system architecture eliminates the need for analog-to-digital converters and signal amplifiers, reducing cost and power consumption, while enabling wireless ultra high frequency (UHF) transmission of sensor data. Integrated algorithms analyze the influence of biomechanical variables on athlete performance, enabling real-time diagnostics. The proposed model-based methodology offers a scalable and accurate solution for intelligent sports instrumentation and beyond. Full article

Flow stabilization and velocity uniformity in a Göttingen-type closed-circuit subsonic aerodynamic wind tunnel with an expanded test section are investigated in this study. Both experimental and numerical approaches were employed. The experiments were performed by using Laser Doppler Anemometry, Pitot tubes, and thermal anemometry. For numerical simulations, Reynolds-averaged Navier–Stokes simulations with a standard k-ε turbulence model were employed to evaluate flow characteristics in the velocity range of 0.05–20 m/s. The study shows that a properly contoured contraction nozzle suppresses inlet turbulence and ensures stable Reynolds-independent core flow. The contraction nozzle significantly accelerates and redistributes the flow, allowing rapid hydrodynamic stabilization and ensuring velocity measurements with high repeatability. These characteristics are inherent in a benchmark facility. Additionally, the study shows that the outlet-to-inlet diameter has the most prominent role in longitudinal velocity distribution in the test section. An optimal ratio of 1.10 was identified, stabilizing the pressure distribution and providing the most uniform longitudinal velocity profile. These findings offer geometry-dependent design guidelines for achieving high-quality measurements in Göttingen-type wind tunnels with expanded test sections and support accurate velocity measurement instrument calibration and aerodynamic testing. Full article