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Particle Velocity Sensor and Its Application in Near-Field Noise scanning Measurement

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Journal of Applied Mathematics and Physics 2019年第11期7卷 2902-2908页

作者： Xuecong Zhang Di Liu Xiaoguang Li Yunfei Liu Qijie Tu Yu Zhou Institute of Television and Electroacoustics Beijing China College of Underwater Acoustic Engineering Harbin Engineering University Harbin China

The Particle Velocity Sensor (PVS) is a kind of acoustic transducer which measures the particle velocity directly with figure-of-eight directivity. This paper proposes a near-field noise scanning technology based on the research of PVS, pressure-particle velocity (P-U) probe, and its application in noise source identification. Firstly, the principle and characteristics of PVS are presented. Secondly, a P-U probe is designed on the basis of PVS development. Finally, the noise measurement experiment for a single source is arranged and conducted. The result shows that the proposed P-U probe performs well in near-field noise source identification and localization.

关键词： Particle Velocity Pressure-Particle Velocity Probe Near-Field Noise scanning Measurement Acoustic Imaging

Robustness Evaluation of a Novel Proton Beam Geometry for Head and Neck Patients Treated with Pencil Beam scanning Therapy

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International Journal of Medical Physics, Clinical Engineering and Radiation Oncology 2018年第3期7卷 308-322页

作者： Sheng Huang Haoyang Liu Jiajian Shen Huifang Zhai Maura Kirk Brett Hartl Alexander Lin James McDonough Stefan Both Haibo Lin Department of Radiation Oncology University of Pennsylvania Philadelphia PA USA New York Proton Center New York NY USA New Jersey Proton Therapy Center Somerset NJ USA Mayo Clinic Phoenix AZ USA University Medical Center Groningen Groningen The Netherlands

Background: To evaluate the robustness of head and neck treatment using proton pencil beam scanning (PBS) technique with respect to range uncertainty (RU) and setup errors (SE), and to establish a robust PBS planning strategy for future treatment. Methods and Materials: Ten consecutive patients were planned with a novel proton field geometry (combination of two posterior oblique fields and one anterior field with gradient dose match) using single-field uniform dose (SFUD) planning technique and the proton plans were dosimetrically compared to two coplanar arc VMAT plans. Robustness of the plans, with respect to range uncertainties (RU = ± 3% for proton) and setup errors (SE = 2.25 mm for proton and VMAT), in terms of deviations to target coverage (CTV D98%) and OAR doses (max/mean), were evaluated and compared for each patient under worst case scenarios. Results: Dosimetrically, PBS plans provided better sparing to larynx (p = 0.005), oral cavity (p < 0.001) and contralateral parotid (p = 0.004) when compared to VMAT. CTV D98% variations were higher from SE than from RU for proton plans (-1.1% ± 1.3 % vs -0.4% ± 0.7% for nodal CTV and -1.4% ± 1.2 vs -0.4% ± 0.5% % for boost CTV). Overall, the magnitudes of variation of CTV D98% to combined SE and RU were found to be similar to the impact of the SE on the VMAT plans (-1.6% ± 1.9% vs -1.7% ± 1.4% for nodal CTV and -1.9% ± 1.6% vs -1.3% ± 1.5% for boost CTV). Compared to VMAT, a larger range of relative dose deviations were found for OARs in proton plans, but safe doses were maintained for cord (41.8 ± 3.6 Gy for PBS and 41.7 ± 3.9 Gy for VMAT) and brainstem (35.2 ± 8.4 Gy for PBS and 36.2 ± 5.1 Gy for VMAT) in worst case scenarios. Conclusions: Compared to VMAT, proton plans containing three SFUD fields with superior-inferior gradient dose matching had improved sparing to larynx, contralateral parotid and oral cavity, while providing similar robustness of target coverage. Evaluation of OAR dose robustness showed highe

关键词： Head and Neck Robustness Proton Therapy Pencil Beam scanning

Qualitative analysis of re mineralized carious lesions subjected to fluoride supplement through confocal laser scanning microscope

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Open Journal of Stomatology 2011年第3期1卷 55-60页

作者： K. Shashikala N. V. Sheela 不详

Aim: 1] Comparative evaluation of the linear depth of induced remineralized lesions after subjecting to fluoride supplements and 2] To assess the average fluorescence at both the demineralized and the remi-neralized zones in all the three study groups under confocal laser scanning microscope. Method: Forty five sound human premolars extracted for orthodon-tic reasons were decoronated 1 mm below the ce-mento-enamel junction and coated with nail varnish except for a 3 × 3 mm window on the buccal surface. The samples were placed in 50 ml of de mineralizing solution at pH 4.6 for 96 hours. Following deminera-lization, the lower half of the 3 × 3 mm window in all the samples were covered with nail varnish to serve as control. The samples were randomly divided into three groups of fifteen teeth each (n = 15) and speci-mens in group A[Nfd] were remineralized using non-fluoridated dentifrice [control], those in groups B [Fd5] and group C [Fd10] using 500 ppm and 1000 ppm of fluoride containing dentifrice, respectively. The specimens were subjected to a 20 day reminera-lization treatment regimen and were sectioned into 100 μm thick sections and two images were captured on the buccal surface from either side of the midpoint of occluso-cervical length using confocal laser scan-ning microscope [CLSM]. Results: were tabulated and statistically analyzed by Anova. Study concluded that 1000 ppm fluoridated dentifrice showed a greater degree of remineralization than other groups and confocal laser scanning microscopes gives promising results in the diagnosis of early enamel lesions over the conventional methods.

关键词： Dental Caries Fluoridated Dentifrice Confocal Laser scanning Microscope

The scanning Characteristics of Spatial and Temporal Dynamic Pictures of the Seismicity in the South Yellow Sea and Its Coast Region

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Earthquake Research in China 2000年第2期14卷 37-46页

作者： Diao Shouzhong, Guo Aixiang and Wang HongweiSeismological Bureau of Shandong Province, Jinan 250014, China Seismological Bureau of Shandong Province Jinan 250014China

On the basis of the viewpoint of preparation of strong earthquakes in group, the spatial andtemporal scanning characteristics of the seismicity in the South Yellow Sea and its coast regionare studied, and some problems regarding the prediction of seismic hazard are also *** results show that the seismic activity of M=4. 0 earthquakes has overall presented arelative stable state, but the partially concentrated area wbich evolves and migrates and theanomalous low b-value area have appeared in different periods, and the moderately strongearthquakes with M=5. 0～6. 0 have taken place on the edge of the anomalous area. Theaccumulative frequency of M=4. 0 earthquakes in the anomalous area presents non-linearindex acceleration and the moderately strong earthquakes have appeared in the late period ofthe non-linear index acceleration of M=4. 0 earthquakes or in the later anomalous tranquilperiotl. The spatial and temporal uneven Phenomenon of seismicity has some stability andreproducibility, and has

关键词： Earthquake Hazard dynamic picture scanning Risk Prediction

Application of Dual-Source CT TurboFlash Coarse Pitch scanning in Coronary Artery Imaging

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Open Journal of Medical Imaging 2018年第3期8卷 64-72页

作者： Shuiqing Zhuo Xiaoling Chen Jingping Yu Haoqiang He Guixiao Xu Chuanmiao Xie State Key Laboratory of Oncology in South China Collaborative Innovation Center for Cancer Medicine Department of Imaging Sciences of Sun Yat-sen University Cancer Center Guangzhou China Joint Surgery The First Affiliated Hospital of Sun Yat-sen University Guangzhou China

Objective: To compare and analyze the image quality and radiation dose of three scanning modes of dual-source CT coronary artery retrospectively, and to discuss the application value of TurboFlash coarse pitch scanning mode. Methods: The imaging data of 100 patients who underwent CT coronary angiography (CCTA) using Siemens force CT retrospective gated triggering spiral scan (RES-SPIRAL), adaptive prospective gated triggering sequence scan (SEQ) and prospective coarse pitch scan (TurboFlash) retrospectively was collected. The image quality was evaluated by objective and subjective methods. The effective radiation dose of patients was compared and analyzed, and the indications of the three scanning modes were analyzed. The application value of dual-source CT TurboFlash coarse pitch scanning in coronary artery imaging was evaluated. Results: The results showed that the left main coronary artery, the right coronary artery and their tertiary branches could be clearly displayed in the three groups of images: the left anterior descending branch, the left circumflex branch, and their three-level branches. There was no statistical difference in subjective image quality among the three groups of pictures (P > 0.05). There was no statistical difference in objective evaluation indexes, such as CT value, SNR, CNR and Noise among the three groups (P > 0.05). The patient radiation dose results showed that the effective radiation dose ED of RES-SPIRA scan was (9.22 ± 1.33) mSv. The dose of SEQ was (2.88 ± 2.47) mSv, and the dose of TurboFlash was (0.51 ± 0.16) mSv. There was significant difference in comparison of the three groups (P 0.05). RES-spiral scanning had the highest radiation dose and TurboFlash coarse pitch scanning (TurboFlash) had the lowest radiation dose. Conclusion: TurboFlash coarse pitch scanning is low in dosage, fast in speed and wide in adaptability. It is especially suitable for the elderly, children, coma and other patients who cannot cooperate with breath-h

关键词： Dual-Source CT Coronary Computed Tomographic Angiography Coarse Pitch Spiral scanning Image Quality Radiation Dose

Functional Microvascular Anatomy of the Horse Eye: A scanning Electron Microscopic Study of Corrosion Casts

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Open Journal of Veterinary Medicine 2014年第5期4卷 91-101页

作者： Hiroyoshi Ninomiya Tomo Inomata Department of Laboratory Animal Science Azabu University Sagamihara Japan Yamazaki Gakuen University Tokyo Japan

Objective: This study presents the microvasculature of the horse iris, ciliary process, retina, and choroid and discusses the functional significance of the vasculature. Procedure: Seven horses were used for this study. The ocular vascular system was injected with methylmethacrylate resin via the carotid artery, and the vascular corrosion casts were observed using a scanning electron microscope. Results: The iridial vessels showed a wavy course. The ciliary process was supplied by 2 arterial routes: the iridial and ciliary arterial circles. The subjects displayed a paurangiotic retina with retinal vessels extending only a short distance around the disc. The retinal arterioles and venules ran in closely related pairs, and the capillaries formed hairpin loops. No central retinal artery was seen in the equine eyes examined. The choriocapillaris in the avascular retina was arranged in honeycomb hexagon lobules and formed a more densely packed network than that in the vascular retina. There were 2 distinct venous drainage systems in the horse choroid: the vortex veins and the posterior ciliary veins. The vortex vein ampulla was flattened and showed a slit-like lumen at the merge site with the ophthalmic vein. The vortex veins demonstrated a marked constriction before leaving the eye. Discussion: The 2 choroidal drainage systems may compensate each other in event of occlusion. The ampulla and the constriction in the vortex veins may act as a valve regulating the blood flow to keep the eye at an optimum size and the intraocular pressure within the normal physiological range.

关键词： Corrosion Cast Eye Horse Microvasculature scanning Electron Microscopy

Application of Single Scan Differential scanning Calorimetry Technique for Determination of Kinetic Parameters of Crystallisation in Se-Sb-Ag

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Journal of Crystallization Process and Technology 2019年第1期9卷 1-11页

作者： Nidhi Yaduvanshi Deepak Kumar Nikhil Rastogi Ashok Kumar Department of Physics JSS Academy of Technical Education Noida India Department of Physics IFTM University Moradabad India Department of Physics Harcourt Butler Technical University Kanpur India

A single scan has been performed in Differential scanning Calorimetry (DSC) at a heating rate of 15oC/min under non-isothermal conditions to investigate the crystallization kinetics of glassy Se90Sb10-xAgx alloys (where x = 2, 4, 6, 8). For this purpose, Handerson’s theory based on non-isothermal method for thermal analysis of single-scan DSC data has been used. The activation energy of crystallization and order parameter has been determined and composition dependence of these parameters has been discussed.

关键词： Differential scanning Calorimetry Crystallization Order Parameter

OBSERVATION AND ANALYSIS OF BLOOD CONTACTING SURFACE OF LEFT VENTRICULAR ASSIST DEVICE WITH scanning ELECTRON MICROSCOPY

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Medical Bulletin of Shanghai Jiaotong University 1989年第Z1期12卷 72-78页

作者：王惠荪金永安秦家楠 Laboratory of Artificial Heart Shanghai Institute of Biomedical Engineering SSMU Shanghai

Thrombus formation in the artificial heart blood pump is a complex problem. The most important factor of thrombosis in the blood pump is the quality of blood contacting surface which is related to hemocompatibility of materials and micromorphololgy or roughness of the surface. So it is necessary to understand the morphology of the surface inside of blood pump in order to develop and improve a good quality blood pump. The authors observed and analysed the inner surface of blood pumps (both preimplanted and postimplanted) with scanning electron microscopy (SEM) providing a means for evaluating the blood pumps and for developing good quality of blood pumps. It was observed that there were four kinds of surface defects on the inner surface of the blood pumps: air bubble domes, open bubble craters, contaminated dust and gel particles. Microcrakes had also been found on the diaphragm of the postimplanted pump. But in the newly improved blood pump that had been imlanted for 16 days, there were few defects on the blood contacting surface, and only a little fibrinous layer observed. It could be considered that the current design and modifications are reasonable. Since some problems associated with the surface defects and thrombosis still existed, further improvement in fabrication process and quality control procedures with SEM are under way.

关键词： left ventricular assist device scanning electron microscopy polyurethane blood contacting surface surface defects thrombosis

Achieving Directionality and Transmit Diversity via Integrating Beam Pattern scanning (BPS) Antenna Arrays and OFDM

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Wireless Sensor Network 2010年第2期2卷 186-196页

作者： Peh Keong Teh Seyed Alireza Zekavat 不详

In this paper, we introduce a novel merger of antenna arrays with scanning beam patterns, and Orthogonal Frequency Division Multiplexing (OFDM) systems. Controlled time varying phase shifts are applied to the antenna array elements mounted at the base station with beam patterns directed toward the desired user. This creates a small beam pattern movement called Beam Pattern scanning (BPS). In rich scattering environments BPS creates a time varying environment leading to time diversity exploitable at the receiver enhances its probability-of-error performance. Here, we apply OFDM signals to BPS antenna arrays, and we achieve: (1) directionality, which supports Space Division Multiple Access (SDMA);and (2) a time diversity gain, which leads to high performance. We discuss the structure of the base station antenna array and the OFDM receiver that exploits time diversity. We also introduce the merger of BPS and multi-carrier OFDM (MC-OFDM) systems. In MC-OFDM each bit is transmitted over all sub-carriers after serial to parallel conversion. BPS/ MC-OFDM receiver exploits both time diversity inherent in BPS, and frequency diversity inherent in MC-OFDM transmission technique. Simulation results show high Probability-of-error performance is achie- vable via BPS/OFDM and BPS/MC-OFDM schemes comparing to the traditional OFDM and MC-OFDM, respectively. Simulations also reveal that MC-OFDM system as well as its merger with BPS is capable of mitigating large Peak-to-Average Ratio (PAPR) problem in traditional OFDM system. In addition, performance simulations with coded OFDM (COFDM) and coded MC-OFDM (MC-COFDM) and their merger with BPS are studied.

关键词： OFDM MC-OFDM Antenna Array Beam Pattern scanning Transmit Diversity.