大学院工学研究院

椎名 達雄

シイナ タツオ  (Tatsuo Shiina)

基本情報

所属
千葉大学 大学院工学研究院 先進理化学専攻 准教授
学位
博士(工学)(東京理科大学)

J-GLOBAL ID
200901042177955291
researchmap会員ID
5000067613

論文

 78
  • Nofel Lagrosas, Kosuke Okubo, Hitoshi Irie, Yutaka Matsumi, Tomoki Nakayama, Yutaka Sugita, Takashi Okada, Tatsuo Shiina
    2023年4月17日  
    Abstract. A horizontally pointing lidar is planned for deployment with other instruments in Fukushima, Japan, to continuously monitor and characterize the optical properties of radioactive aerosols and dust in an uninhabited area. Prior to installation, the performance of the lidar is tested at Chiba University. Data from the continuous operation of the lidar from August 2021 to February 2022 are analyzed for extinction and depolarization ratio. These are compared with the weather sensor and particulate matter (PM2.5) measurements to quantify the relationship between atmospheric conditions and optical properties of near-ground aerosols. The results show that lidar data’s extinction coefficient and depolarization ratio can have a quantifiable relationship with relative humidity (RH), absolute humidity, rain rate, wind speed, wind direction, and PM2.5 concentration. Analysis of the seven-month data shows that the optical properties of aerosol and dust depend on the combined effects of the weather parameters. An increase in RH or PM2.5 concentration does not imply an increase in radioactive aerosols. The average extinction coefficient and depolarization ratio of aerosols and dust originating from the land and ocean show different values and opposing trends which can aid in determining the occurrence of ground-based radioactive dust and aerosols. The information obtained from analyzing the interrelationship among lidar, weather parameters, and PM2.5 concentration is essential in assessing the occurrence of radioactive aerosols and characterizing local aerosol-weather relationships in a radioactive area. This result provides essential information in describing radioactive aerosols in Fukushima.
  • Kosuke Okubo, Nofel Lagrosas, Tatsuo Shiina
    Scientific Reports 13(1) 2023年3月11日  査読有り最終著者
    Abstract Visualization of dust flow and wind dynamics near the ground surface are essential for understanding the mixing and interaction between geosphere and atmosphere near the surface. Knowing the temporal dust flow is beneficial in dealing with air pollution and health issues. Dust flows near the ground surface are difficult to monitor because of their small temporal and spatial scale. In this study, we propose a low-coherence Doppler lidar (LCDL) for measuring dust flow near the ground with high temporal and spatial resolutions of 5 ms and 1 m, respectively. We demonstrate the performance of LCDL in laboratory experiments using flour and calcium carbonate particles released into the wind tunnel. LCDL experiment results show a good agreement with anemometer measurement in wind speeds ranging from 0 to 5 m/s. The LCDL technique can reveal dust’s speed distribution, which is affected by mass and particle size. As a result, different speed distribution profiles can be used to determine dust type. The simulation results of dust flow coincide well with the experimental results.
  • Decai Huyan, Nofel Lagrosas, Tatsuo Shiina
    Photonics 10(2) 146-146 2023年1月31日  査読有り最終著者
    An optical coherence tomography (OCT) system based on the ghost imaging (GI) technique is developed for correctly imaging in scattering media. Usually, the scattering in the media leads to a decrease in the signal-to-noise ratio of the reconstructed image. This problem can be solved by using ghost imaging-OCT(GI-OCT), but the number of patterns required for GI reconstruction depends on the concentration of the scattering media. Therefore, studying the relationship between the intensity distribution in reconstructed images and the optical properties of scattering media is essential. In this study, image reconstruction is carried out in scattering media with a concentration of 0.0% to 1.4%, diluted from processed milk. Using the structural similarity index method (SSIM) to analyze the reconstruction condition, it is found that the target image can be reconstructed correctly when the SSIM value is more than 0.7. By analyzing the intensity distribution of the reconstructed image, the results show that the extinction coefficient of the scattering media is negatively correlated with the contrast of the reconstructed image and positively correlated with the scattering intensity. Their correlation coefficients are −0.94 and 0.99, respectively.
  • Jumar G. Cadondon, Edgar A. Vallar, Tatsuo Shiina, Maria Cecilia D. Galvez
    Photonics 10(2) 144-144 2023年1月30日  査読有り
    The real-time chlorophyll-a pigment monitoring of C. reinhardtii is studied using our developed LED fluorescence light detection and ranging (LiDAR) system. It features a portable set-up that uses a pulsed LED module with an excitation wavelength of 385 nm. We were able to monitor the different growth phases of C. reinhardtii with specific cultivation parameters. The developed fluorescence LiDAR system showed the linear correlation of its chlorophyll-a signal with the optical density and EEM fluorescence measurements at 680 nm emission wavelength. Water quality and weather parameters were also measured, which explains the variation in the growth dynamics of C. reinhardtii during the sampling period. The results from the monitoring demonstrated a different technique that can be used in estimating algal biomass in the environment.
  • Decai Huyan, Nofel Lagrosas, Tatsuo Shiina
    Proceedings of the 11th International Conference on Photonics, Optics and Laser Technology(PHOTOPTICS) 67-73 2023年  

MISC

 33
  • Tatsuo Shiina
    29TH INTERNATIONAL LASER RADAR CONFERENCE (ILRC 29) 237 2020年  
    The LED mini lidar was improved to monitor Raman scattering echoes. The Raman scattering signal indicates a certain gas concentration and it can distinguish the target from the other materials. It is so weak, 1/1000 of Mie scattering echoes, but even enough to be stimulated from the target gas with LED pulsed beam. At first, we developed a compact Raman lidar with micro pulse DPSS laser to detect hydrogen gas quantitatively. We replaced it with the LED pulse module, which was calculated enough potential to stimulate Raman scattering and detect the target gas. The next task is the activity measurement of such a target gas. To validate the potential of the LED Raman lidar, we conducted the sea surface atmosphere measurement. As a result, the unique relationship between the surface atmosphere and sea water echoes was observed. In this report, we state the concrete specification of the LED mini Raman lidar and some results of the activity observations.
  • Prane Mariel Ong, Nofel Lagrosas, Tatsuo Shiina, Hiroaki Kuze
    29TH INTERNATIONAL LASER RADAR CONFERENCE (ILRC 29) 237 2020年  
    The combined use of remote sensing and in-situ monitoring instruments could help improve the assessment of near-surface aerosol properties. In this paper, we analyze the diurnal behavior of aerosol extinction coefficients, alpha(Ext)(lambda), at lambda=349 and 550 nm using a lidar and a present weather detector, respectively. We utilize the aerosol optical thickness (AOT), single scattering albedo (SSA), and Angstrom exponent (AE) from SKYNET sky radiometer, and AE from aethalometer, and the number distribution from optical particle counter to evaluate the effect of relative humidity (RH) on aerosol extinction coefficients. It is found that although alpha(Ex)(lambda) often exhibits a positive correlation with the ambient RH, this relation is obscured when both the number distribution and particle size change simultaneously. Moreover, alpha(Ext) at 349 nm is more sensitive to this change than at 550 nm.
  • Prane Mariel B. Ong, Tatsuo Shiina, Naohiro Manago, Hiroaki Kuze, Hiroki Senshu, Naohito Otobe, George Hashimoto, Yasuhiro Kawabata
    EPJ Web of Conferences 176 2018年4月13日  査読有り
    A compact LED lidar was constructed and fieldtested with the aim to observe the Mars' dust devils. To be able to fit it on the Mars rover, a specialized Cassegrain telescope was designed to be within a 10 cm-cube, with a field of view of 3mrad. The transmitter has 385 nm LED light source with 3 cm opening, 70mrad divergence, 0.75W (7.5nJ/10ns) pulse power, and 500 kHz repetition frequency. The configuration of the optical system is biaxial to easily configure the overlap between their optical axes.
  • Xiafukaiti Alifu, Ziqi Peng, Tatsuo Shiina, Hiroaki Kuze
    Proceedings of SPIE - The International Society for Optical Engineering 10791 2018年  
    © 2018 SPIE. We focused on the propagation property of an annular beam in strong scattering random media such as nimbostratus or dense fog. An annular beam as a lidar transmitted beam can propagate a longer distance even through atmospheric fluctuation. The reason is that an annular beam can self-transform to a non-diffracting beam, which is called non-diffractive effect. In this work, the center peak intensity as result of non-diffractive effect was generated after the propagation of an annular beam in random media with different concentrations and propagation distances. The linear relationship between the propagation distance and the transport mean free path calculated from the media concentration that caused the maximum center peak intensity was obtained. The generation condition of the non-diffractive beam was discussed under arbitrary parameters of beam diameter, propagation distance and media concentration.
  • 椎名 達雄, 島田 翔平, 森 康久仁
    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報 115(452) 49-54 2016年2月18日  

書籍等出版物

 7

共同研究・競争的資金等の研究課題

 20