Search Results (12)

In the N$\nu$DEx collaboration, a high-pressure gas TPC is being developed to search for the neutrinoless double beta decay. The use of electronegative ⁸²SeF₆ gas mandates an ion-TPC. The reconstruction of the z coordinate is to be realized by exploiting the feature of multiple species of charge carriers. As the initial stage of the development, we studied the properties of the ${\mathrm{SF}}_6$ gas, which is non-toxic and has a similar molecular structure to ${\mathrm{SeF}}_6$. In the paper, we present the measurement of drift velocities and mobilities of the majority and minority negative charge carriers found in ${\mathrm{SF}}_6$ at a pressure of 750 Torr, slightly higher than the local atmospheric pressure. The reduced fields range between 3.0 and 5.5 Td. This was performed using a laser beam to ionize the gas inside a small TPC, with a drift length of 3.7 cm. A customized charge-sensitive amplifier was developed to read out the anode signals induced by the slowly drifting ions. The closure test of the reconstruction of the z coordinate using the difference in the velocities of the two carriers was also demonstrated. Full article

To monitor the position and profile of therapeutic carbon beams in real-time, in this paper, we proposed a system called HiBeam-T. The HiBeam-T is a time projection chamber (TPC) with forty Topmetal-II- CMOS pixel sensors as its readout. Each Topmetal-II- has 72 × 72 pixels with the size of 83 μm × 83 μm. The detector consists of the charge drift region and the charge collection area. The readout electronics comprise three Readout Control Modules and one Clock Synchronization Module. This Hibeam-T has a sensitive area of 20 × 20 cm and can acquire the center of the incident beams. The test with a continuous 80.55 MeV/u ¹²C⁶⁺ beam shows that the measurement resolution to the beam center could reach 6.45 μm for unsaturated beam projections. Full article

The accuracy of ultrasonic flowmeter time delay measurement is directly affected by the processing method of the ultrasonic echo signal. This paper proposes a method for estimating the time delay of the ultrasonic gas flowmeter based on the Variational Mode Decomposition (VMD)–Hilbert Spectrum and Cross-Correlation (CC). The method improves the accuracy of the ultrasonic gas flowmeter by enhancing the quality of the echo signal. To denoise forward and reverse ultrasonic echo signals collected at various wind speeds, a Butterworth filter is initially used. The ultrasonic echo signals are then analyzed by Empirical Mode De-composition (EMD) and VMD analysis to obtain the Intrinsic Mode Function (IMF) containing distinct center frequencies, respectively. The Hilbert spectrum time–frequency diagram is used to evaluate the results of the VMD and EMD decompositions. It is found that the IMF decomposed by VMD has a better filtering performance and better anti-interference performance. Therefore, the IMF with a better effect is selected for signal reconstruction. The ultrasonic time delay is then calculated using the Cross-Correlation algorithm. The self-developed ultrasonic gas flowmeter was tested on the experimental platform of the gas flow standard devices using this signal processing method. The results show a maximum indication error of 0.84% within the flow range of 60–606 m³/h, with a repeatability of no more than 0.29%. These results meet the 1-level accuracy requirements as outlined in the national ultrasonic flowmeters calibration regulation JJG1030-2007. Full article

An air-coupled transducer was developed in this study, utilizing hollow glass microsphere-organosilicon composites as an acoustically matching layer, which demonstrated outstanding acoustic performance. Firstly, a comparison and analysis of the properties and advantages of different substrates was carried out to determine the potential application value of organosilicon substrates. Immediately after, the effect of hollow glass microspheres with different particle sizes and mass fractions on the acoustic properties of the matching layer was analyzed. It also evaluated the mechanical properties of the matching layer before and after optimization. The findings indicate that the optimized composite material attained a characteristic acoustic impedance of 1.04 MRayl and an acoustic attenuation of 0.43 dB/mm, displaying exceptional acoustic performance. After encapsulating the ultrasonic transducer using a 3D-printed shell, we analyzed and compared its emission and reception characteristics to the commercial transducer and found that its emission acoustic pressure amplitude and reception voltage amplitude were 34% and 26% higher, respectively. Finally, the transducer was installed onto a homemade ultrasonic flow meter for practical application verification, resulting in an accuracy rate of 97.4%. Full article

Collecting ambient energy to power various wearable electronics is considered a prospective approach to addressing their energy consumption. Mechanical and thermal energies are abundantly available in the environment and can be efficiently converted into electricity based on different physical effects. Hydrogel-based energy harvesters have turned out to be a promising solution, owing to their unique properties including flexibility and biocompatibility. In this review, we provide a concise overview of the methods and achievements in hydrogel-based energy harvesters, including triboelectric nanogenerators, piezoelectric nanogenerators, and thermoelectric generators, demonstrating their applications in power generation, such as LED lighting and capacitor charging. Furthermore, we specifically focus on their applications in self-powered wearables, such as detecting human motion/respiration states, monitoring joint flexion, promoting wound healing, and recording temperature. In addition, we discuss the progress in the sensing applications of hydrogel-based self-powered electronics by hybridizing multiple energy conversion in the field of wearables. This review analyzes hydrogel-based energy harvesters and their applications in self-powered sensing for wearable devices, with the aim of stimulating ongoing advancements in the field of smart sensors and intelligent electronics. Full article

In order to explore the corrosion damage behavior of plasma-sprayed NiCoCrAlY/magnesia-stabilized zirconia (18~22 wt.% MgO-ZrO₂, MSZ) thermal barrier and anti-ablation coatings in a salt spray environment, a series of neutral salt spray (NSS) tests for 96 h (N-2), 192 h (N-4) and 288 h (N-6) were carried out on the coatings. The microstructures, composition distributions, potentiodynamic polarization curves, bonding strengths and anti-ablation properties of the coatings before and after the NSS tests were characterized. The results show that, with the increase in salt spray time, the expansion and overflow of corrosion products (Fe_xO_y) led to more defects forming inside the coating; the porosity of the top coat (TC) of N-6 increased to 15.2% in comparison to that of the blank control sample (N-0), which was 8.5%. According to the potentiodynamic polarization curves, accelerated corrosion occurred in the coating samples after the salt spray time reached 192 h, and the corrosion current density rapidly surged from 2.2 × 10⁻⁸ A·cm⁻² (N-4) to 2.2 × 10⁻⁵ A·cm⁻² (N-6). Similar degradation tends could be found in the bonding strengths and mass ablation rates of the coatings due to the accumulation of loose corrosion products on the substrate, which affected the bonding states of the coatings and promoted their spalling under an oxyacetylene flame (OAF). As a result, the maximum service life of the NiCoCrAlY/MSZ coatings in the neutral salt spray environment was about 192 h. This work is instructive for studying the environmental adaptability of metal/ceramic double-layer coatings. Full article

Flexible pressure sensors usually exhibit high sensitivity, excellent resolution, and can be mass-produced. Herein, a high-resolution, capacitive, paper-based, 3D-printed pressure sensor with a simple, low-cost preparation method is proposed. The sensor has a wide detection range (300–44,000 Pa), a short response time (<50 ms), and high mechanical stability during repeated loading/unloading (3750 Pa). It can measure the weight of an object precisely, from which the shape of the object can be predicted. The sensor can also perform gait detection. The advantages presented by low-cost, high sensitivity, wide detection range, and the ability to be mass-produced make these sensors potential candidates for applications in contact detection and wearable medical devices. Full article

The External-target Experiment (CEE) at the Cooling Storage Ring of the Heavy-Ion Research Facility in Lanzhou (HIRFL-CSR) will be the first large-scale experiment in nuclear physics independently developed in China covering the GeV energy regime. The beam monitor located at the center front of the CEE accurately measures the position of the particles with a few tens of um accuracy in a non-interceptive way. This unique advantage significantly improves the accuracy of the particle track reconstructions. This beam monitor’s readout electronics consist of the Front-end module (FEM), Readout Control Module (RCM), and Clock Synchronization module (CSM). Twhe novel Topmetal series pixel sensors directly collect the ionized charge along the track of the ion beam while it passes through the gas in the beam monitor. Lab test proves that the readout electronics have an INL of less than 1%. In addition, the prototype beam monitor can measure the position of the ⁴⁰Ar beam of 320 MeV/u with a resolution of ~6.9 μm. This paper will discuss the design, characterization, and test of the readout electronics. Full article

The water covering the Earth’s surface not only supports life but also contains a tremendous amount of energy. Water energy is the most important and widely used renewable energy source in the environment, and the ability to extract the mechanical energy of water is of particular interest since moving water is ubiquitous and abundant, from flowing rivers to falling rain drops. In recent years, triboelectric nanogenerators (TENGs) have been promising for applications in harvesting kinetic energy from water due to their merits of low cost, light weight, simple structure, and abundant choice of materials. Furthermore, TENGs can also be utilized as self-powered active sensors for monitoring water environments, which relies on the output signals of the TENGs caused by the movement and composition of water. Here, TENGs targeting the harvest of different water energy sources have been systematically summarized and analyzed. The TENGs for harvesting different forms of water energy are introduced and divided on the basis of their basic working principles and modes, i.e., in the cases of solid–solid and solid–liquid. A detailed review of recent important progress in TENG-based water energy harvesting is presented. At last, based on recent progresses, the existing challenges and future prospects for TENG-based water energy harvesting are also discussed. Full article

Electrochromic materials have attracted much attention due to their promising applications in smart windows and thermal control. However, NiO is a weak point for a complementary ECD and needs to be improved due to its low optical modulation and charge density. In this work, the W-doped NiO films are designed and prepared by RF magnetron co-sputtering to improve the performance of the NiO. The results shows that the optical modulation of the W-NiO (52.7%) is significantly improved compared with pure NiO (33.8%), which can be assigned to the increase in lattice boundaries due to the W doping. The response time of W-NiO is 8.8 s for coloring and 7.2 s for bleaching, which is similar to that of NiO film. The all-solid-state electrochromic devices (ECDs) that employed W-NiO as a complementary layer are prepared and exhibit a high-transmittance modulation of 48.5% in wavelengths of 450–850 nm and an emittance modulation of 0.28 in 2.5–25 μm, showing great application potential in the field of smart windows and spacecraft thermal control devices. The strategy of preparing NiO doped by W indicates an innovative direction to obtain ECDs with high performance. Full article

The adaptable monitoring of the ubiquitous magnetic field is of great importance not only for scientific research but also for industrial production. However, the current detecting techniques are unwieldly and lack essential mobility owing to the complex configuration and indispensability of the power source. Here, we have constructed a self-powered magnetic sensor based on a subtle triboelectric nanogenerator (TENG) that consists of a magnetorheological elastomer (MRE). This magnetic sensor relies on triboelectrification and electrostatic induction to produce electrical signals in response to the MRE’s deformation induced by the variational magnetic field without using any external power sources. The fabricated magnetic sensor shows a fast response of 80ms and a desirable sensitivity of 31.6 mV/mT in a magnetic field range of 35–60 mT as well as preliminary vectorability enabled by the multichannel layout. Our work provides a new route for monitoring dynamic magnetic fields and paves a way for self-powered electric-magnetic coupled applications. Full article

In this article, the effects of swimming gyrotactic microorganisms for magnetohydrodynamics nanofluid using Darcy law are investigated. The numerical results of nonlinear coupled mathematical model are obtained by means of Successive Local Linearization Method. This technique is based on a simple notion of the decoupling systems of equations utilizing the linearization of the unknown functions sequentially according to the order of classifying the system of governing equations. The linearized equations, that developed a sequence of linear differential equations along with variable coefficients, were solved by employing the Chebyshev spectral collocation method. The convergence speed of the SLLM technique can be willingly upgraded by successive applying over relaxation method. The comparison of current study with available published literature has been made for the validation of obtained results. It is found that the reported numerical method is in perfect accord with the said similar methods. The results are displayed through tables and graphs. Full article