Synthetic high-resolution near-IR spectra of the Sun for planetary data reductions made from ATMOS/Spacelab-3 and Atlas-3 data     

Haingja Seo  Sungwon Hwang  Aeran Jung  Ji Hyun Kim  Joo Hyeon Kim  Kap-Sung Kim  Jinny Lee  Minhwan Jang 《Icarus》2007,192(1):287-295

We have constructed synthetic solar spectra for the 2302-4800 cm⁻¹ (2.08-4.34 μm) range, a spectral range where planetary objects mainly emit reflected sunlight, using ATMOS (Atmospheric Trace Molecule Spectroscopy)/Spacelab-3 and Atlas-3 spectra, of which resolution is 0.01 cm⁻¹. We adopted Voigt line profiles for the modeling of line shapes based on an atlas of line identifications compiled by Geller [Geller, M., 1992. Key to Identification of Solar Features. A High-Resolution Atlas of the Infrared Spectrum of the Sun and the Earth Atmosphere from Space. NASA Reference Publ. 1224, vol. III. NASA, Washington, DC, pp. 1-22], who derived solar line positions and intensities from contaminated high-resolution solar spectra obtained by ATMOS/Spacelab-3. Because the ATMOS spectra in these wavelength ranges are compromised by absorption lines of molecules existing in Earth's high-altitude atmosphere and in the compartment of the spacecraft, the direct use of these high-resolution solar spectra has been inconvenient for the data reductions of planetary spectra. We compared the synthetic solar spectra with the ATMOS spectra, and obtained satisfactory fits for the majority of the solar lines with the exception of abnormal lines, which do not fit with Voigt line profiles. From the model fits, we were able to determine Voigt line parameters for the majority of solar lines; and we made a list of the abnormal lines. We also constructed telluric-line-free solar spectra by manually eliminating telluric lines from the ATMOS spectra and filling the gaps with adjacent continua. These synthetic solar spectra will be useful to eliminate solar continua from spectra of planetary objects to extract their own intrinsic spectral features.  相似文献   

Analytical and experimental studies on midstory isolated buildings with modal coupling effect     

Shiang‐Jung Wang  Jenn‐Shin Hwang  Kuo‐Chun Chang  Meng‐Hui Lin  Bo‐Han Lee 《地震工程与结构动力学》2013,42(2):201-219

In a midstory isolated building, the isolation system is incorporated into the midstory rather than the base of the building. Because of the flexibility of the substructure below the isolation system in a midstory isolated building, the contribution of higher modes to the seismic responses of the midstory isolated structure may not be negligible, especially when the coupling of higher modes exists. To investigate this modal coupling effect, a simplified three‐lumped‐mass structural model of the midstory isolated building is assumed in this study. Through the equivalent linear analysis and shaking table tests, it is found that the coupling of higher modes may lead to enlarged acceleration responses at the super‐floor and superstructure above the isolation layer. Accordingly, a simple method to prevent the midstory isolation design from the coupling of higher modes attributed to the improper design of the substructure and superstructure is proposed in this paper. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Accumulation of butyltin compounds in finless porpoises (Neophocaena asiaeorientalis) from Korean coast: Tracking the effectiveness of TBT regulation over time     

Minkyu Choi  Yong-Rock An  Kyum Joon Park  In-Seok Lee  Dong-Woon Hwang  Jinyu Kim  Hyo-Bang Moon 《Marine pollution bulletin》2013,66(1-2):78-83

The concentrations of butyltin compounds (BTs) were measured in the livers of finless porpoises (Neophocaena asiaeorientalis) caught off the Korean coast in 2003 and 2010, to assess the effectiveness of legislative action against BTs. The concentrations of BTs ranged from 65.1 to 1432 (average: 370) ng/g wet weight, within the ranges reported by previous studies. The levels of BTs in almost all the samples exceeded the suggested threshold value, implying potential adverse health effects from the BT exposures. Concentrations of BTs were significantly correlated with body length, weight, and age of finless porpoises, but were not correlated with sex. Spatial differences in the concentrations of BTs were not observed between Yellow and South Seas, while there was a significant decrease in BTs between the sampling years of 2003 and 2010. Our result indicates that the effectiveness on TBT ban has reached to marine mammals in the coastal waters of Korea.  相似文献   

A study of the Newmark sliding block displacement functions     

Gwo-Shyang Hwang  Cheng-Hsing Chen 《Bulletin of Earthquake Engineering》2013,11(2):481-502

The Newmark sliding block displacement function, the curve showing the relation between the sliding response and the critical acceleration ratio, is important because its applications have been widespread in seismic designs of earth structures. The aims of this article are twofold: (a) to give a new point of view on the related abscissa parameter, and (b) to provide a new methodology for better understanding the displacement functions. Regarding the new methodology, the study of the properties of the displacement functions is divided into two parts: one is the property of the amplitude at a specific abscissa, and the other is the shape property. After derivations, validations and calibrations, the authors have obtained a simple expression for the characteristic slippage. Simple expressions have also been obtained for the shapes of the displacement functions using observations and derivations. The authors compare their results for the characteristic slippage predictions and for the shapes of displacement functions with related previous studies. Finally, empirical attenuation relationships of the characteristic slippage for different ground types are developed.  相似文献   

Desorption of Hydrophobic Organic Chemicals from Fragment-Type Microplastics     

Hwang?Lee  Da-Eun?Byun  Ju?Min?Kim  Jung-Hwan?KwonEmail author 《Ocean Science Journal》2018,53(4):631-639

Microplastics provide an important medium for hydrophobic organic chemicals (HOCs), and the desorption of HOCs from microplastics is an important process for the dynamics of HOCs associated with microplastics. Although desorption kinetics has been studied for microplastics with ideal geometries, most of the microplastics isolated from the environment are irregular fragment-type microplastics. This study investigated the desorption of six model HOCs from polyethylene (PE) and polypropylene (PP) fragments to artificial seawater and compared the results with those predicted assuming ideal geometries (e.g., sphere and infinitely flat sheet) of microplastics. The experimental desorption was explained well by the model predictions with the characteristic radius for a sphere and the thickness for a plate estimated from visual imaging. The mass fraction remaining at the later stage of desorption was higher than the model simulation assuming a single characteristic length, likely due to the heterogeneity of the particle size distribution. Although there are inevitable uncertainties, it would be useful to assign a single length dimension in desorption modeling for even fragment-type microplastics, especially for the estimation of desorption half-life.  相似文献   

Effects of Antimicrobial Air Filters on the Viability and Culturability of Airborne Bacteria          下载免费PDF全文

Gi Byoung Hwang  Bo Mi Kwon  Seung Jae Lee  Byung Uk Lee  Kyoung Mi Sim  Gwi‐Nam Bae  Jae Hee Jung 《洁净——土壤、空气、水》2016,44(10):1268-1277

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Determining uraniferous host rocks and minerals as a source of dissolved uranium in granite aquifers near the central Ogcheon metamorphic belt,Korea     

Jeong Hwang  Sang-Ho Moon  Edward M. Ripley  Yang Ho Kim 《Environmental Earth Sciences》2014,72(10):4035-4046

Korea has suffered from high U concentrations in some groundwater, especially in Daejeon near the central Ogcheon metamorphic belt. However, clear explanation has not been yet reported for the uranium sources in groundwater. This study is focused on identifying the potential uraniferous host rocks and finding the exact U-minerals serving as uranium sources in groundwater near Daejeon, Korea. For this work, we performed an in situ gamma ray spectrometer survey and a laboratory microscopic study with electron micro-probe analysis. The measurements for radioactive element content did not show any prominent K- and Th-anomaly spots, but they did result in several observations of considerable U-anomalies in pegmatite and hydrothermally altered granite, in which uraninite, coffinite and uranophane were found by electron micro-probe analysis. The occurrences of U-minerals are the first such discovery except in the low-grade U deposits of the Ogcheon metamorphic belt in Korea. All observed U-minerals were intimately associated with hydrothermal alteration. The remarkably low Th/U ratios in the studied uraniferous rocks also suggest that the U enrichment was genetically related to a post-magmatic hydrothermal process. However, many of the uraniferous parts were controlled by a reducing environment and occurred near the border between graphite-rich mica-schist and Jurassic leucocratic granite. The findings on these uraniferous rocks can be used in elucidating the source of highly enriched U groundwater in granite aquifers as well as in understanding the occurrence of igneous U-minerals, which has not been previously reported in Korea.  相似文献   

Likely Population-Level Effects of Contaminants on a Resident Estuarine Fish Species: Comparing <Emphasis Type="Italic">Gillichthys mirabilis</Emphasis> Population Static Measurements and Vital Rates in San Francisco and Tomales Bays     

Catherine R. McGourty  James A. Hobbs  William A. Bennett  Peter G. Green  Hyun-Min Hwang  Naoaki Ikemiyagi  Levi Lewis  Jason M. Cope 《Estuaries and Coasts》2009,32(6):1111-1120

Gillichthys mirabilis population static measurements (abundance, age, and size class structures) and vital rates (growth, mortality, recruitment) were monitored on an annual basis from 2002 to 2007. Population-level metrics were used to gauge habitat quality at two study sites (a contaminated site and a reference site) in two large northern California estuaries (San Francisco and Tomales Bays). San Francisco Bay populations exhibited slower growth and higher mortality rates and contained higher amounts of contaminants than Tomales Bay. Recruitment rates were highest at contaminated sites (Stege Marsh and Walker Creek) in 3 years out of 5 years, suggesting low adult survival. This study suggests that population-level effects on a residential fish may be attributed to estuarine contamination on the US Pacific coast.  相似文献   

Comparison of volatile organic compounds in stormwater and groundwater in Seoul metropolitan city,South Korea     

Soonyoung Yu  Pyeong-Koo Lee  Seong-Taek Yun  Sang-Il Hwang  Gitak Chae 《Environmental Earth Sciences》2017,76(9):338

Volatile organic compounds (VOCs) detected in stormwater were compared with VOCs present in emission sources, air, groundwater, and influent to sewage treatment plants in Seoul to understand their fate and transport in the urban hydrological system. Stormwater is a carrier of non-point source pollutants and contains VOCs from land surfaces and air. Samples of stormwater and influent to sewage treatment plants were collected and analyzed for 61 VOCs, while the VOCs in emission sources, air and groundwater were investigated through literature reviews for comparison. The results showed that the most frequently detected VOCs in stormwater were similar to those in air. However, the atmospheric concentrations of benzene, toluene, ethylbenzene, and xylenes (BTEX), and methyl tertiary-butyl ether (MTBE) were too low to explain their frequent detection and high concentrations in stormwater. As a result, land surfaces seem to be a primary source of these VOCs in stormwater. Comparison of the VOCs in stormwater and groundwater showed that toluene and MTBE were frequently detected in both media, but more often and at higher concentrations in stormwater. This finding indicates that stormwater recharge is a source of toluene and MTBE in groundwater. Regarding groundwater, land surfaces seem to be a primary source of toluene, while urban air is the primary source in the case of MTBE. Specifically, the MTBE values in air were sufficiently high to explain its levels in groundwater, which had continually increased and remained low afterward. Furthermore, the high ratios of TEX (toluene, ethylbenzene, and xylenes) to benzene and MTBE in stormwater indicated that TEX had additional sources other than vehicles, most likely hydrocarbon solvents. These solvents seem to be a primary source of TEX and other frequently detected VOCs in stormwater. However, trichloroethylene (TCE), tetrachloroethylene (PCE) and their dechlorination intermediates were far more frequently detected and at higher concentrations in groundwater than in stormwater. Additionally, their concentrations frequently exceeded the water-quality criteria. It seems that halogenated solvents had produced contamination plumes of these chlorinated VOCs in the Seoul aquifer. Based on VOCs detected in Seoul, stormwater was mixed with groundwater in combined sewers and flowed into sewage treatment plants. The results imply that organic solvents should be handled with extreme care to protect groundwater quality.  相似文献   

Erratum to: Concentrations of heavy metals in marine wild fishes captured from the Southern Sea of Korea and associated health risk assessments     

Dong-Woon Hwang  Seong-Soo Kim  Seong-Gil Kim  Dong-Sun Kim  Tae-Hoon Kim 《Ocean Science Journal》2017,52(3):467-467

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