- 标题
- 摘要
- 关键词
- 实验方案
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Enhancement of objects in photoacoustic tomography using selective filtering
摘要： Here we developed a real-time photoacoustic tomography (PAT) imaging acquisition device based on the linear array transducer utilized on ultrasonic devices. Also, we produced a phantom including diverse contrast media and acquired PAT imaging as the light source wavelength was changing to see if the contrast media reacted. Indocyanine green showed the highest reaction around the 800-nm band, methylene blue demonstrated the same in the 750-nm band, and gold nanoparticle showed the same in the 700-nm band. However, in the case of superparamagnetic iron oxide, we observed not reaction within the wavelength bands used herein to obtain imaging. Moreover, we applied selective filtering to the acquired PAT imaging to remove noise from around and reinforce the object’s area. Consequentially, we could see the object area in the imaging was effectively detected and the image noise was removed.
关键词： Photoacoustic image,real-time,back projection algorithm,selective filtering,ultrasonic imaging
更新于2025-09-23 15:23:52
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Impact of photodynamic therapy versus ultrasonic scaler on gingival health during treatment with orthodontic fixed appliances
摘要： Objectives: Poor oral hygiene during treatment with fixed appliances results in plaque accumulation. The presence of bacteria in the gingival crevice triggers an inflammatory reaction in the gingival tissues. The aim of this study was to compare the impact of two preventive treatments, photodynamic therapy (PDT), and ultrasonic scaler (US), on gingival health in patients under fixed orthodontic treatment. Methods: Twenty orthodontic patients were randomly allocated to two groups: PDT or US. Each group received seven sessions [days 0, 15, 30, 45, 90 (3-months follow-up), 180 (6-months follow-up), 270 (9-months follow-up)] of experimental interventions, and clinical parameters [Plaque index(PI); gingival index(GI); probing depth(PD)], periodontopathogens [Aggregatibacter actinomycetemcomitans; Porphyromonas gingivalis; Prevotella intermedia; Micromonas micros; Fusobacterium nucleatum; Tannerella forsythia; Campylobacter rectus; Eikenella corrodens; Capnocytophaga sp.] and protein markers [IL-1b;IL-1ra;IL-6;IL-10; TNF-a;FGF-2/FGF basic] were monitored at baseline and at 3, 6, and 9 months. ANOVA, Student’s t-test with Bonferroni correction and ANOVA with multiple rank test were used to identify differences between groups (P < 0.05). Results: Clinical assessments [PI, GI, and PD] yielded no differences (P > 0.05) between groups, which showed a major decrease at the start of the trial. Reductions in total colony forming units (log CFU reduction) were observed with both treatments, although to a greater extent in the PDT group, but with no differences between groups (P > 0.05). Similar reductions in log CFU counts of P. gingivalis, P. intermedia, and F. nucleatum were observed in both groups (P > 0.05). The two groups also showed similar trends for inflammatory mediators with decreased levels of IL-1b, IL-10, and TNF-a, whereas IL-6 and IL-1ra levels remained stable and those of FGF-2 were increased after both interventions, with no differences (P > 0.05) between groups. Conclusion: Both PDT and US methods proved similar effectiveness for the treatment of gingival inflammation induced by fixed orthodontic appliances.
关键词： photodynamic therapy,cytokines,ultrasonic scaler,orthodontic treatment,gingival inflammation,periodontopathogens
更新于2025-09-23 15:23:52
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Environmentally friendly methodology for fouling removal in pipeline based on leaky guided wave generated by quasi-axisymmetric excitation mode
摘要： In this paper, an environmental and innovative clean technique for pipeline fouling is proposed, which is based on leaky ultrasonic guided waves (LUGWs) generated by quasi-axisymmetric excitation mode. The cavitation, which induced by the LUGWs in liquid medium, is employed for removing fouling inside a pipe. Cavitation corrosion and high-speed jet generated by the collapse of cavitation bubbles destroy fouling layer, and no by-products are formed during the removal process, which means that fouling removal in this way is friendly to the environment. The working frequency is determined by finite element method models and experiment. The effect of removal and its uniformity are measured by mass analysis, scanning electron microscope and energy-dispersive spectroscopy from macro to micro. The descaling experiment results show that the proposed method is able to remove the fouling inside a pipe uniformly.
关键词： Finite element method,Fouling removal,Quasi-axisymmetric,Leaky ultrasonic guided waves
更新于2025-09-23 15:23:52
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Seismic-physical Modeling Using a Micro Quasi-Michelson Fiber-optic Interferometer
摘要： A micro fiber-optic interferometer was proposed and demonstrated experimentally. The device only comprised a fiber-optic taper containing a refractive index modification (RIM) region that was written by a femtosecond laser. The coupling and recoupling of core-to-cladding modes were improved by the RIM to be 'window-like'. A well-defined interference spectrum was obtained because of the interference between the recoupled high-order modes, based on the quasi-Michelson interference mechanism. Using the spectral-side band filtering technology, the ultrasonic wave (UW) was detected with a high sensitivity by the proposed interferometer. The key to the success of the sensor is that the micro taper sensing fiber is more easily stretched by the UW-induced strain. Moreover, the interferometer was equipped with a cone-shaped horn to further promote the UW sensitivity of the sensor due to its acoustic focusing performance. This sensor offers a better method to realize seismic-physical modeling by scanning detection and reconstructing the echoes.
关键词： Fiber sensor,ultrasonic wave imaging,physical model
更新于2025-09-23 15:22:29
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Estimation of Energy and Time Savings in Optical Glass Manufacturing When Using Ultrasonic Vibration-Assisted Grinding
摘要： Energy and time savings are highly important aspects of green manufacturing. Ultrasonic vibration-assisted grinding (UVAG) is a high-efficiency, low-energy-consumption processing method for optical components made from hard and brittle materials. This work presents an experimental investigation of the specific grinding energy and the subsurface damage depth in UVAG of optical glasses to estimate the increased energy and time savings produced when using UVAG in optical glass manufacturing. The normal and tangential grinding forces of traditional grinding (TG) and axial UVAG processes on optical glasses were investigated for various machining parameters. The specific grinding energies during the TG and UVAG of the optical glasses were calculated and analyzed from the perspective of the energy consumption of the grinding process. The subsurface damage depths in optical glass during TG and UVAG were measured as an estimate of the machining quality, and the magnetorheological polishing spot method was used to analyze the time saved in subsequent polishing processes. The results show that UVAG can reduce energy consumption during the grinding of glass and produce significant time savings in subsequent polishing processes. The UVAG process therefore shows good potential for use in green manufacturing of optical components.
关键词： Energy saving,Sub-surface damage,Ultrasonic vibration-assisted grinding,Specific grinding energy
更新于2025-09-23 15:22:29
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Investigations on Synthesis, Characterization and Humidity Sensing Properties of ZnO and ZnO-ZrO2 Composite Nanoparticles Prepared by Ultrasonic Assisted Wet Chemical Method
摘要： In the present investigations, Zinc oxide (ZnO) and ZnO-ZrO2 composite nanoparticles were synthesized by ultrasonic assisted wet chemical method to investigate their structural, optical and humidity sensing properties. The synthesized nanoparticles were characterized by the techniques like X ray diffraction (XRD), UV-Vis absorption spectroscopy, Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). XRD and EDS were employed to confirm the phase formation and phase purity respectively. SEM micrographs showed that morphology of the parent compound ZnO is considerably changed with varying concentration of ZrO2. The optical absorption spectra showed that optical absorption of ZnO decreases with increase in ZrO2 content in the composite. The observed band gap values for ZnO and ZnO-ZrO2 composites were higher as compared to the bulk sample. The humidity sensing performance was substantiated for all the samples and the result of effect of concentration of ZrO2 in ZnO-ZrO2 composites on sensitivity, response and recovery time are discussed in detail.
关键词： Zinc oxide,Composite nanoparticles,Zirconium dioxide,Ultrasonic,Humidity sensor
更新于2025-09-23 15:22:29
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Uniform Sb <sub/>2</sub> S <sub/>3</sub> optical coatings by chemical spray method
摘要： Antimony sulfide (Sb2S3), an environmentally benign material, has been prepared by various deposition methods for use as a solar absorber due to its direct band gap of ≈1.7 eV and high absorption coefficient in the visible light spectrum (1.8 × 105 cm?1 at 450 nm). Rapid, scalable, economically viable and controllable in-air growth of continuous, uniform, polycrystalline Sb2S3 absorber layers has not yet been accomplished. This could be achieved with chemical spray pyrolysis, a robust chemical method for deposition of thin films. We applied a two-stage process to produce continuous Sb2S3 optical coatings with uniform thickness. First, amorphous Sb2S3 layers, likely forming by 3D Volmer–Weber island growth through a molten phase reaction between SbCl3 and SC(NH2)2, were deposited in air on a glass/ITO/TiO2 substrate by ultrasonic spraying of methanolic Sb/S 1:3 molar ratio solution at 200–210 °C. Second, we produced polycrystalline uniform films of Sb2S3 (Eg 1.8 eV) with a post-deposition thermal treatment of amorphous Sb2S3 layers in vacuum at 170 °C, <4 × 10?6 Torr for 5 minutes. The effects of the deposition temperature, the precursor molar ratio and the thermal treatment temperature on the Sb2S3 layers were investigated using Raman spectroscopy, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy and UV–vis–NIR spectroscopy. We demonstrated that Sb2S3 optical coatings with controllable structure, morphology and optical properties can be deposited by ultrasonic spray pyrolysis in air by tuning of the deposition temperature, the Sb/S precursor molar ratio in the spray solution, and the post-deposition treatment temperature.
关键词： vacuum annealing,Volmer–Weber growth,antimony sulfide,thin films,ultrasonic spray
更新于2025-09-23 15:22:29
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Structural, morphological and transport properties of nanostructured La1-Sr Co0.2Fe0.8O3- thin films, deposited by ultrasonic spray pyrolysis
摘要： The main aim of this study is to improve the electrochemical properties of LaFeO3-δ perovskite as cathode by strontium and cobalt doping in lanthanum and iron sites. Ultrasonic spray pyrolysis (USP) following sintering process in air was utilized to synthesize La1-xSrxCo0.2Fe0.8O3-δ (LSCF) with 0 ≤ x ≤ 0.4. X–ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and impedance spectroscopy techniques were used to study the structure, surface morphology and transport properties of the deposited films. Contrary to what might expect, up to x = 0.4, single orthorhombic phase of La1-xSrxCo0.2Fe0.8O3-δ have been obtained for all deposited films. Impedance spectroscopy results at intermediate temperatures (500–700 °C) indicated that by increasing of strontium, the conductivity increases, and activation energy decreases from 0.41 eV for x = 0–0.24 eV for x = 0.4.
关键词： IT-SOFC,LSCF,Ultrasonic spray pyrolysis
更新于2025-09-23 15:22:29
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Eco-friendly highly sensitive transducers based on a new KNN-NTK-FM lead-free piezoelectric ceramic for high-frequency biomedical ultrasonic imaging applications
摘要： High-frequency ultrasonic imaging with improved spatial resolution has gained increasing attention in the field of biomedical imaging. Sensitivity of transducers plays a pivotal role in determining ultrasonic image quality. Conventional ultrasonic transducers are mostly made from lead-based piezoelectric materials that may be harmful to the human body and the environment. In this study, a new (K,Na)NbO3-KTiNbO5-BaZrO3-Fe2O3-MgO (KNN-NTK-FM) lead-free piezoelectric ceramic was utilized in developing eco-friendly transducers for high-frequency biomedical ultrasonic imaging applications. A needle transducer with a small active aperture size of 0.45 × 0.55 mm2 was designed and evaluated. The transducer exhibits great performance with a high center frequency (52.6 MHz), a good electromechanical coupling (keff ~ 0.45), a large bandwidth (64.4% at -6 dB), and a very low two-way insertion loss (10.1 dB). Such high sensitivity is superior to those transducers based on other lead-free piezoelectric materials and can even be comparable to the lead-based ones. Imaging performance of the KNN-NTK-FM needle transducer was analyzed by imaging a wire phantom and an agar tissue-mimicking phantom. Imaging capabilities of the transducer were further demonstrated by ex vivo imaging studies on a porcine eyeball and a rabbit aorta. The results suggest that the KNN-NTK-FM piezoceramic has many attractive properties over other lead-free piezoelectric materials in developing eco-friendly highly sensitive transducers for high-frequency biomedical ultrasonic imaging applications.
关键词： lead-free piezoelectric ceramic,Biomedical ultrasonic imaging,high-frequency ultrasonic transducer,eco-friendly
更新于2025-09-23 15:21:21
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Comparison of ultrasonic pachymetry and Fourier-domain optical coherence tomography for measurement of corneal thickness in dogs with and without corneal disease
摘要： Several ultrasonic and Fourier-domain optical coherence tomography (FD-OCT) pachymeters are used to measure corneal thickness in canine patients and research subjects. This study assessed the reliability of and consistency between two ultrasonic pachymetry (USP) devices, Pachette 3 and Accupach VI, as well as automated and manual measurements obtained using FD-OCT in dogs with and without corneal disease. Corneal thickness measurements were compiled from 108 dogs and analyzed using mixed effects linear regression, with Bonferonni adjustments for post-hoc comparisons, to determine the effects of age, weight and disease state. Data are presented as predicted mean ± standard error. Canine corneal disease can result in marked increases in thickness that frequently exceed the upper limits of measurement of some pachymetry devices developed for human use. In this study, the corneas of dogs with endothelial disease or injury frequently exceeded the upper limits of quantitation of 999 and 800 μm, respectively. Using values <800 μm for the Accupach VI and automated FD-OCT pachymeters, respectively. Of the two devices where measurements >1000 μm were obtained, manual FD-OCT demonstrated less variability than the Pachette 3. Corneal thickness increased linearly with age and weight with an increase of 6.9 ± 0.8 μm/year and 1.6 ± 0.38 μm/kg body weight (P < 0.005 and P = 0.038, respectively).
关键词： Corneal thickness,Corneal endothelial dystrophy,Optical coherence tomography,Ultrasonic pachymetry,Canine
更新于2025-09-23 15:21:21