• Title/Summary/Keyword: Li dust

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Development of SWIR 3D Lidar System with Low Optical Power Using 1 Channel Single Photon Detector (1채널 단일광자검출기를 이용한 낮은 광출력의 SWIR(Short Wave Infrared) 3D 라이다 시스템 개발)

  • Kwon, Oh-Soung;Lee, Seung-Pil;Shin, Seung-Min;Park, Min-Young;Ban, Chang-Woo
    • Journal of the Korean Society of Industry Convergence
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    • v.25 no.6_3
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    • pp.1147-1154
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    • 2022
  • Now that the development of autonomous driving is progressing, LiDAR has become an indispensable element. However, LiDAR is a device that uses lasers, and laser side effects may occur. One of them is the much-talked-about eye-safety, and developers have been satisfying this through laser characteristics and operation methods. But eye-safety is just one of the problems lasers pose. For example, irradiating a laser with a specific energy level or higher in a dusty environment can cause deterioration of the dust particles, leading to a sudden explosion. For this reason, the dust ignition proof regulations clearly state that "a source with a pulse period of less than 5 seconds is considered a continuous light source, and the average energy does not exceed 5 mJ/mm 2 or 35 mW" [2]. Energy of output optical power is limited by the law. In this way, the manufacturer cannot define the usage environment of the LiDAR, and the development of a LiDAR that can be used in such an environment can increase the ripple effect in terms of use in application fields using the LiDAR. In this paper, we develop a LiDAR with low optical power that can be used in environments where high power lasers can cause problems, evaluate its performance. Also, we discuss and present one of the directions for the development of LiDAR with laser power limited by dust ignition proof regulations.

Comparison of Li(I) Precipitation from the Leaching Solution of the Dust from Spent Lithium-ion Batteries Treatment between Sodium Carbonate and Ammonium Carbonate (폐리튬이온전지 처리시 발생한 더스트 침출용액으로부터 Na2CO3와 (NH4)2CO3에 의한 리튬(I) 석출 비교)

  • Nguyen, Thi Thu Huong;Lee, Man Seung
    • Resources Recycling
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    • v.31 no.5
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    • pp.34-41
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    • 2022
  • Smelting reduction of spent lithium-ion batteries results in metallic alloys, slag, and dust containing Li(I). Precipitation of Li2CO3 was performed using the synthetic leachate of the dust. Herein, the effects of the precipitant and addition of non-aqueous solvents on the precipitation of Li(I) were investigated. Na2CO3 was a more effective precipitating agent than (NH4)2CO3 owing to the hydrolysis reaction of dissolved ammonium and carbonate. The addition of acetone or ethanol improved the Li(I) precipitation percentage for both the precipitants. When using (NH4)2CO3, the Li(I) precipitation percentage increased at a solution pH of 12. Under the same conditions, the Li(I) precipitation percentage using Na2CO3 was much higher than that using (NH4)2CO3.

Effect of social order, perch, and dust-bath allocation on behavior in laying hens

  • Wang, Yanan;Zhang, Runxiang;Wang, Lisha;Li, Jianhong;Su, Yingying;Li, Xiang;Bao, Jun
    • Animal Bioscience
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    • v.35 no.2
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    • pp.299-307
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    • 2022
  • Objective: The objective of this study was to determine the effects of different social ranking order (SRO) and the enrichments (perch and dust-bath) allocation (EA) on behavior of laying hens in furnished cages. Methods: Total experimental period was 4 weeks. There were 216 Hy-line brown layers beak-trimmed at 1 d of age and selected randomly at 14 weeks of age from a commercial farm, and randomly divided into 36 cages with 6 hens in each cage. High enrichments (perch and dust-bath) allocation (HEA) and low enrichments (perch and dust-bath) allocation (LEA) were provided. Video observations of behavior were obtained from the focal hens between 14 and 18 weeks of age and perching, dust-bathing and other general behaviors of the hens with different social orders were measured. Results: Perching behavior of high SRO hens (HSR) were significantly higher than that of medium SRO hens (MSR), and that of the MSR were significantly higher than that of low SRO hens (LSR) (p<0.01), except for lying on perch (p>0.05). The hens in the high EA cage (HEAC) showed more lying behavior on perch than those in the low EA cage (LEAC) (p<0.01). The different SRO and EA did not affect dust-bathing behavior except vertical wing-shaking behavior (p<0.05). The LEA did not affect general behaviors (p>0.05), except standing and preening behaviors (p<0.01 and p<0.05), of which the hens in the HEAC showed less standing (p<0.01) and more preening behavior than the hens in the LEAC. Conclusion: The SRO of laying hens has a significant effect on the perching behaviors, but SRO and EA have little effect on dust-bathing and general behaviors.

Thermal Radiation Pressure Force on Atmosphereless Bodies

  • Bach, Yoonsoo P.;Ishiguro, Masateru
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.1
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    • pp.64.1-64.1
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    • 2019
  • Thermal fracture and cracking near the perihelion are found to be a possible mechanism to produce the dust trail of the near-Earth asteroid, (3200) Phaethon (Jewitt and Li, 2013, ApJ 771, L36). It is, however, not well understood how the debris particles were escalated from the regolith against the asteroid's gravity. Thus, the scenario that these debris particles are responsible for the detected activities (Li and Jewitt, 2013, ApJ, 145, 154), is not complete yet. Here, we hypothesize that the thermal radiation pressure around the perihelion passage would exert substantial force outwards from the regolith on dust grains, and they can be lifted up and contributes the dust tail formation with further help of solar radiation pressure. Our modeling indicates that particles with sizes of roughly ~1-10 micron can be ejected from Phaethon by the mechanism, while a detailed model of gravitational field is required for accurate estimation of the particle size range. Our idea is not necessarily limited to Phaethon case, but is applicable to any atmosphereless bodies.

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Geochemical Characteristics and Pollution Level of Heavy Metals of Asian Dust in Daejeon Area, 2007 (spring season) (2007년 봄철 대전지역에서 발생한 황사 및 대기부유물의 지구화학적 특성 및 중 금속의 오염도)

  • Lee, Pyeong-Koo;Youm, Seung-Jun;Bae, Beob-Geun
    • Economic and Environmental Geology
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    • v.45 no.3
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    • pp.217-235
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    • 2012
  • We evaluated the geochemical characteristics and their potential pollution of Asian Dusts in Daejeon, Korea during spring 2007. Compared with the chemical compositions of soils in source area of Asian Dust, those of aerosols in Daejeon were enriched with trace elements (ten to hundred fold), inferring that pollutants from China have affected on local environment in adjoining country such as Korea. Chemical analysis of aerosols during Asian dust showed that fine particles ($PM_{2.5}$) contained high contents of trace elements such as Cr, Cu, Pb, Zn, V, S, As, Cd, Co, Ni, Mo, Sb, Cs, Rb, Th, Sc and Y. In the case of TSP (Total Suspended Particle), Zr, Sr, Ba, Li, Th and U were contained much more than other trace elements. The contents of some elements (i.e. Li, Cs, Co, U, Cr, Ni, Rb, V, Th, Y, Sr and Sc) in aerosols collected in Asian Dust period, which are not likely enriched by air pollutants, were higher (2 - 4.2 fold) than those in Non Asian Dust period, indicating that these elements could be used as indicator elements for determining the occurrence of Asian Dust phenomena (especially, Sr, V, Cr & Li). In the case of Asian Dust coming through the big cities and/or industrial areas of China, the domestic aerosols had higher contents of trace elements (such as S, Cd, Zn, Pb, Cu, Mo and As) than those from Northeastern China via North Korea, indicating that the transportation courses of air mass are very important to determine the pollution degrees. Using the enrichment factors of trace elements in aerosols during Asian Dust and Non Asian Dust, we identified that some elements (i.e. S, Zn, Cu, Pb, As, Mo and Cd) were most problematic in terms of environmental hazard aspects, and these elements could affect adverse effects on human health as well as ecosystem and surface environment (soil and water) through long-lived precipitation.

3-Dimensional Finite Element Analysis for Collecting Structure of Combustible Metal Dust During Explosion (가연성 금속분진 폭발시 저장 및 포집용 구조물에 대한 3차원 유한요소 해석)

  • Jang, Chang-Bong;Yong, Jong-Won;Baek, Jong-Bae;Kwon, Hyuck-Myun;Ko, Jae-Wook
    • Journal of the Korean Institute of Gas
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    • v.15 no.5
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    • pp.19-24
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    • 2011
  • Due to the latest industrial flow comes mainly switch to high-tech industries, combustible metals as Al, Mg, Li, Zn more require to use for the aircraft, car, cell phones, electronics and others. As a result, Increasing the processing of combustible metals due to increase in amount of combustible metals giving rise dust explosions also. Most Explosions caused by combustible metal dust, occurred in air cleaning device of local exhaust ventilation to capture and store the combustible dust. Therefore, this study was conducted to present and analyze technically that deformation and rupture shape of air cleaning device structure by Finite Element Analysis(FEA) rather than a simple prediction, in case of explosion occurs in an air cleaning device.

Two distinct types of dust polarization in the disk and its vicinity around the protostar TMC-1A

  • Aso, Yusuke;Kwon, Woojin;Ching, Tao-Chung;Lai, Shih-Ping;Li, Zhi-Yun;Hirano, Naomi;Rao, Ramprasad
    • The Bulletin of The Korean Astronomical Society
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    • v.45 no.1
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    • pp.57.2-57.2
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    • 2020
  • We observed the Class I protostar TMC-1A in polarized dust emission at 1.3 mm at a spatial resolution of ~40 au using ALMA. Previous observations revealed a disk (r~100 au), surrounded by an infalling envelope, and a CO outflow going in the north-south direction in TMC-1A. Our observations detected polarized dust emission in a central region (r~50 au) and ~100 au north and south of the central protostar. The former polarization is likely due to self-scattering because of the polarization direction along the disk minor axis, the polarization fraction independent of Stokes I, and a high optical thickness. The latter polarization is roughly in the outflow region. The position and direction, particularly in the north, imply multiple possible mechanisms: magnetically or mechanically aligned dust grains in the outflow or in an accretion flow.

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Urinary 1-Hydroxypyrene Glucuronide and 8-Hydroxydeoxyguanosine as Biomarkers of the Asian Dust Event

  • Yoo, Dong-Ho;Li, Zhong-Min;Lee, Kyoung-Ho;Cho, Soo-Hun;Kwon, Ho-Jang;Deahee Kang
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2003.10b
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    • pp.187-187
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    • 2003
  • This study evaluated the potential usefulness of urinary 1-hydroxypyrene glucuronide (1-OHPG) and 8-hydroxy-deoxyguanosine (8-OHdG) as biomarkers of the Asian Dust event. Urine samples were collected from 224 subjects (112 children and 112 their mothers) from Seoul (n=60), Inchon (n=104) and Pohang (n=60) in South Korea. (omitted)

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