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Arc-Induced Long Period Gratings in Erbium-Doped Fiber
摘要： In this paper, we report about the fabrication of long period gratings (LPGs) directly into an Erbium-doped fiber, by using the electric arc discharge technique. The attention is focused on the writing process and the resulting properties, by considering gratings with different periods and measuring their spectra over a wide wavelength range. The LPGs show high order attenuation bands with tunable resonance wavelengths and depths up to 30 dB, while the lengths of the final devices are in range 20–45 mm. The polarization-dependent loss of these LPGs is also measured, for the first time in this kind of fiber. As further novelty, the influence of surrounding refractive index, applied strain, and temperature is investigated and discussed in comparative manner. Based on the achieved results, this fabrication procedure can be adapted to a specific application, for example in optical communications, signal processing, and sensing fields.
关键词： waveguide devices,Fiber gratings,fiber optics systems,sensors
更新于2025-11-28 14:23:57
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Functionalized and oxidized silicon nanosheets: Customized design for enhanced sensitivity towards relative humidity
摘要： The use of completely oxidized two-dimensional (2D) silicon nanosheets (SiNSs) represents a novel approach for the application of 2D silicon-based materials in the nanoelectronics field. Densely stacked and highly porous oxidized SiNSs (OSiNSs) act as a sensitive layer for humidity detection. Due to the oxidation-caused porosity of the SiNSs and the possibility functionalize the 2D surface with hydrophilic groups, this hybrid material exhibits an extremely good sensitivity towards relative humidity (RH). In this work, precise tuning of the SiNSs’ sensing properties by their functionalization is demonstrated. In particular, the modification with methacrylic acid (MAA) groups, leading to SiNS-MAA, and the subsequent deposition on interdigitated electrodes double the capacitance value in the range of 20-85%RH. These values were achieved after the full oxidation of SiNS-MAA in ambient conditions. The mentioned changes in capacitance are extremely high compared to the response of the so far known common polymer humidity sensors. Contrary to that, this response is neutralized when the SiNSs are functionalized with tert-butyl acrylic acid (tBMA), a rather hydrophobic functional group. The fabricated devices show, how the specific functionalization of SiNSs serves as a reliable tool to provide sensitivity towards RH. Similar approach, based on tuning the functionality, can be applied to achieve e.g., sensor array selectivity. For this purpose, the functional groups on the surface of the nanomaterial can be further modified. Additional molecules with sensitivities towards various surrounding conditions could be attached. Furthermore, these functional molecules can be used for subsequent (bio)molecule immobilization, which can serve as sensitive molecular groups towards surrounding substrates and gases. However, one of the main challenges in sensor technology is to find a highly selective solution: a sensor system capable to differentiate among different vapor species. The described strategy can serve as an access towards new and promising solutions, which can help to face this issue in modern nanomaterials-based technology.
关键词： two-dimensional materials,porous silicon,functionalization,silicon nanosheets,hybrid systems,moisture content
更新于2025-11-21 11:20:48
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Evaluation of various tissue-clearing techniques for the three-dimensional visualization of liposome distribution in mouse lungs at the alveolar scale
摘要： Purpose: To develop a three-dimensional visualization method for evaluating the distribution of pulmonary drug delivery systems and compare four tissue-clearing techniques (ClearT2, CUBIC, ScaleS, and SeeDB2) using intrapulmonary liposomes as drug carriers. Methods: Rhodamine B-labeled liposomes were administered intrapulmonarily to mice using a MicroSprayer, and then fluorescent-labeled tomato lectin was administered intravenously to visualize the general lung structure. Tissue-clearing treatment of the mouse lungs was performed using the standard protocols of the ClearT2, CUBIC, ScaleS, and SeeDB2 techniques. Lung clearing was clarified using laser-scanning confocal microscopy, and three-dimensional images were reconstructed. Results: Fluorescent-labeled tomato lectin was preserved using ClearT2 and SeeDB2 but not using CUBIC and ScaleS. In addition, the liposomes were stable in ClearT2 reagent, but they were mostly degraded in other reagents by surface-active agents. ClearT2 treatment enabled the three-dimensional visualization of intrapulmonary rhodamine B-labeled liposomes at the alveolar scale. Conclusions: These results suggest that the ClearT2 tissue-clearing technique was appropriate for the three-dimensional visualization of intrapulmonary liposomes at the alveolar scale. This study provides important information for selecting and optimizing suitable optical tissue-clearing techniques in lungs for evaluating the distribution of pulmonary drug delivery systems.
关键词： fluorescence preservation,Intrapulmonary distribution,inhalation,liposomes,drug delivery systems,laser-scanning confocal microscopy
更新于2025-11-21 11:08:12
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A MEMS BPSK to ASK converter
摘要： Purpose – The purpose of this paper is to investigate the feasibility of using micro electromechanical systems (MEMS) to convert a binary phase shift keying (BPSK) signal to a simpler amplitude shift keying (ASK) scheme. Design/methodology/approach – The prototype is designed within the SOIMUMPs? fabrication process constraints. The fabrication constraints imposed geometric limitations on what could be tested. These constraints were used to build a mathematical model, which in turn was used to optimize the response using MATLAB?. The optimized design was tested using ?nite element analysis with CoventorWare?, and ?nally lab tests on the fabricated device were performed to con?rm theoretical predictions. Findings – Theoretical predictions compared well with lab measurements on a prototype device measuring 2.9 mm2. The prototype was tested with a carrier frequency of 174 kHz at a BPSK data rate of 3 kHz and carrier amplitude of 6 V. With these parameters, ASK modulation indices of 0.96 and 0.94 were measured at the two output sensors. Originality/value – This study provides a MEMS solution for BPSK to ASK conversion. The study also identi?es what limits betterment of the modulation index and data rate. Such a device has potential application in wireless sensor network (WSN) nodes that have energy harvesters and sensors that are also built in MEMS. Being a MEMS device, it can facilitate integration in such WSN nodes and, hence, potentially reduce size and costs.
关键词： Modulation index,Mixer,ASK detector,Micro electro mechanical systems (MEMS),BPSK converter
更新于2025-11-14 17:28:48
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Engineering Oxygen Migration for Homogeneous Volume Resistive Switching in 3‐Terminal Devices
摘要： Resistive switching effects are in a superb position to tackle the challenges for the near future of nanoelectronics and neuromorphics. Material-wise, the outstanding properties of strongly correlated metallic perovskite oxides, in particular, those displaying metal–insulator transition can be exploited for a new generation of devices based on a volume resistive switching (VRS) phenomenon beyond filamentary and interface ideas. This study reports a full description of this new and robust physical mechanism governing VRS memory effects in mixed-valence mixed-conductor metallic La1?xSrxMnO3?y perovskites by identifying the role and rate limiting steps of oxygen exchange through oxygen partial pressure experiments. It is demonstrated that oxygen migration can be smartly engineered by introducing a CeO2?x capping layer, which is further used to validate the VRS phenomenon by operating a nonvolatile and volumetric proof-of-concept gate-controlled three-terminal conductive bridge device.
关键词： strongly correlated systems,oxygen exchange,nanoelectronics,resistive switching
更新于2025-11-14 17:03:37
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[IEEE 2019 Compound Semiconductor Week (CSW) - Nara, Japan (2019.5.19-2019.5.23)] 2019 Compound Semiconductor Week (CSW) - AlGaAs/GaAs Heterostructure with Hybrid InSb/GaAs and GaSb/GaAs Quantum Dots and Its Optical Characteristics
摘要： Manufacturing execution systems play an important role of bridging high-level enterprise functions and production or manufacturing operations. The embedded systems are usually in charge of controlling execution of the operations. Modern embedded systems have become capable of simultaneous and deterministic execution of control algorithms and IP-based communication, making it possible to create complex cyber–physical systems (CPSs), where the computational and communication resources of a device can be used directly for various control, supervisory, or monitoring functions. The complexity for defining open-knowledge-driven manufacturing execution system (OKD-MES) is in maintaining awareness of overall system state to avoid disruptive actions as various functions may be requested from a system. The problem is that obtaining such information on system state may necessitate collecting data from a number of devices, as there may not be a single data point for state information. This paper describes and illustrates an approach for designing OKD-MES on top of CPSs that controls robot workstations and conveyor-based transportation system of a pallet-based production system.
关键词： Cyber–physical systems (CPSs),manufacturing systems,manufacturing automation,knowledge-based systems
更新于2025-11-14 15:24:45
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Photovoltaic Degradation Climate Zones
摘要： Manufacturing execution systems play an important role of bridging high-level enterprise functions and production or manufacturing operations. The embedded systems are usually in charge of controlling execution of the operations. Modern embedded systems have become capable of simultaneous and deterministic execution of control algorithms and IP-based communication, making it possible to create complex cyber–physical systems (CPSs), where the computational and communication resources of a device can be used directly for various control, supervisory, or monitoring functions. The complexity for defining open-knowledge-driven manufacturing execution system (OKD-MES) is in maintaining awareness of overall system state to avoid disruptive actions as various functions may be requested from a system. The problem is that obtaining such information on system state may necessitate collecting data from a number of devices, as there may not be a single data point for state information. This paper describes and illustrates an approach for designing OKD-MES on top of CPSs that controls robot workstations and conveyor-based transportation system of a pallet-based production system.
关键词： Cyber–physical systems (CPSs),manufacturing systems,manufacturing automation,knowledge-based systems
更新于2025-11-14 15:24:45
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Study of Power Consumption of Timepix3 Detector
摘要： The Timepix3 readout chip — the latest member of the Medipix family of hybrid pixel detectors — brought several new functionalities in comparison with the older Timepix, i.e. a high hit-rate, a time granularity of 1.5625 ns, a data-driven readout scheme (with a per pixel dead time of approximately 475 ns), and the capability of measuring Time-over-Threshold (ToT) and Time-of-Arrival (ToA) in each pixel at the same time. However, the high power consumption of the Timepix3 in the standard setting prevents its use in applications with limited power budget. Moreover, the high power consumption poses the risk of overheating the sensor so that proper cooling is crucial. The presented work investigates the effect of different settings in the analogue and a digital part of the Timepix3 detector on its power consumption. Measurements were performed with the Timepix3 chipboard. The firmware of the Katherine readout was modified so that the user can monitor the power consumptions of analogue and digital part “on-line” (directly in the control software). In standard settings, a power consumption of approximately 1.3 W was found. By changes of internal DACs, the consumption could be reduced to 650 mW. Further reduction was achieved by the change of the clock management in the digital part of the Timepix3. In result, a power consumption of 216 mA could be achieved. In these low power settings, the ToA clock was reduced to 10 MHz and thus the time binning was 100 ns. The energy resolution was not affected significantly. The pixel dead time is also negatively affected when the matrix clock is reduced. In the case of 10 MHz, the minimal per pixel dead time is 1.9 μs.
关键词： databases),Detector control systems (detector and experiment monitoring and slow-control systems,Data acquisition concepts,hardware,algorithms,architecture
更新于2025-09-23 15:23:52
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Adaptive Decentralized Control of Residential Storage in PV-Rich MV-LV Networks
摘要： The rapid adoption of residential-scale photovoltaic (PV) systems in low voltage (LV) networks combined with the falling prices of residential-scale battery energy storage (BES) systems is paving the way for a future in which customers could locally supply most of their energy needs. However, off-the-shelf (OTS) storage systems operate for the sole benefit of the customer (reducing grid imports). This means that charging might not occur during times of high PV generation, resulting in technical issues on LV and medium voltage (MV) networks. This work proposes an adaptive decentralized control strategy for residential-scale BES systems to reduce voltage and thermal issues whilst still benefiting customers. With this strategy, the power charging and discharging rates constantly adapt throughout the day based on clear-sky irradiance, PV generation, demand, and state of charge; significantly reducing reverse power flows and ensuring adequate storage capacity the next morning. A real Australian MV feeder with realistically modelled LV networks is studied using smart meter data. Results demonstrate that the proposed control strategy overcomes the limitations of the OTS BES. It is also shown it can be as effective as an ideal optimization-based approach, being able to manage all technical issues without significantly affecting customers.
关键词： PV Systems,Self-Sufficiency,Distribution Networks,Battery Energy Storage Systems
更新于2025-09-23 15:23:52
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Context-Aware Modelling for Augmented Reality Display Behaviour
摘要： Current surgical augmented reality (AR) systems typically employ an on-demand display behaviour, where the surgeon can toggle the AR on or off using a switch. The need to be able to turn the AR off is in part due to the obstructing nature of AR overlays, potentially hiding important information from the surgeon in order to provide see-through vision. This on-demand paradigm is inefficient as the surgeon is always in one of two sub-optimal states: either they do not benefit at all from the image guidance (AR off), or the field of view is partially obstructed (AR on). Additionally, frequent toggling between the two views during the operation can be disruptive for the surgeon. This paper presents a novel approach to automatically adapt the AR display view based on the context of the surgical scene. Using gaze tracking in conjunction with information from the surgical instruments and the registered anatomy, a multi-Gaussian process model can be trained to infer the desired AR display view at any point during the procedure. Furthermore, a new AR display view is introduced in this model, taking advantage of the context information to only display a partial view of the AR when relevant. To validate the presented approach, a detailed simulation of a neurosurgical tumour contour marking task is designed. A study conducted with 15 participants demonstrates the usefulness of the proposed approach, showing a statistically significant mean reduction of 48% in the average time necessary for the detection of simulated bleeding, as well as statistically significant improvements in total task time.
关键词： Learning and Adaptive Systems,Medical Robots and Systems
更新于2025-09-23 15:23:52