Estimation of non-CO2 GHGs emissions by analyzing burn severity in the Samcheok fire, South Korea     

WON Myoung Soo  KOO Kyo Sang  LEE Myung Bo  LEE Woo Kyun  KANG Kyu-Young 《山地科学学报》2012,9(6):731-741

This study was performed to estimate the emission of non-CO 2 greenhouse gases(GHGs) from biomass burning at a large fire area.The extended methodology adopted the IPCC Guidelines(2003) equation for use on data from the Samcheok forest fire gathered using 30 m resolution Landsat TM satellite imagery,digital forest type maps,and growing stock information per hectare by forest type in 1999.Normalized burn ratio(NBR) technique was employed to analyze the area and severity of the Samcheok forest fire that occurred in 2000.The differences between NBR from pre-and post-fire datasets are examined to determine the extent and degree of change detected from burning.The results of burn severity analysis by dNBR of the Samcheok forest fire area revealed that a total of 16,200 ha of forest were burned.The proportion of the area characterized by a ’Low’ burn severity(dNBR below 152) was 35%,with ’Moderate’(dNBR 153-190) and ’High’(dNBR 191-255) areas were at 33% and 32%,respectively.The combustion efficiency for burn severity was calculated as 0.43 for crown fire where burn severity was ’High’,as 0.40 for ’Moderate’ severity,and 0.15 for ’Low’ severity surface fire.The emission factors for estimating non-CO 2 GHGs were separately applied to CO 130,CH 4 9,NO x 0.7 and N 2 O 0.11.Non-CO 2 GHGs emissions from biomass burning in the Samcheok forest fire area were estimated to be CO 44.100,CH 4 3.053,NO x 0.238 and N 2 O 0.038 Gg.  相似文献   

A new methodology for measuring coastline recession using buffering and non‐linear least squares estimation     

Joon Heo  Jung Hwan Kim  Jin Woo Kim 《International journal of geographical information science》2013,27(9):1165-1177

Coastline recession is one of the best indicators of coastal erosion. Three methods for computing coastline recession – the baseline approach, the dynamic segmentation approach and the area‐based approach – have been used, each of which has one or more drawbacks. To overcome these problems, a new methodology for measuring coastline recession is proposed, using buffering and non‐linear least squares estimation. The proposed method was compared with the three existing methods with respect to two simulated cases and two real coastlines. Test results confirmed that the new method is more reliable than the three other methods, all of which are susceptible to variability of recession, scale, number of line segments, length of coastlines and direction of the baseline. The proposed method, incorporating two physically meaningful values – magnitude and variability of coastline recession according to the mean and standard deviation of coastline offsets, respectively – presents itself as an effective alternative method of assessing coastline recession.  相似文献   

The evaluation of the probability of rock wedge failure using the point estimate method     

Hyuck Jin Park  Jeong-Gi Um  Ik Woo  Jeong Woo Kim 《Environmental Earth Sciences》2012,65(1):353-361

In a probabilistic analysis of rock slope stability, the Monte Carlo simulation technique has been widely used to evaluate the probability of slope failure. While the Monte Carlo simulation technique has many advantages, the technique requires complete information of the random variables in stability analysis; however, in practice, it is difficult to obtain complete information from a field investigation. The information on random variables is usually limited due to the restraints of sampling numbers. This is why approximation methods have been proposed for reliability analyses. Approximation methods, such as the first-order second-moment method and the point estimate method, require only the mean and standard deviation of the random variable; therefore, it is easy to utilize when the information is limited. Usually, a single closed form of the formula for the evaluation of the factor of safety is needed for an approximation method. However, the commonly used stability analysis method of wedge failure is complicated and cumbersome and does not provide a simple equation for the evaluation of the factor of safety. Consequently, the approximation method is not appropriate for wedge failure. In order to overcome this limitation, a simple equation, which is obtained from the maximum likelihood estimation method for wedge failure, is utilized to calculate the probability of failure. A simple equation for the direct estimation of the safety factors for wedge failure has been empirically derived from failed and stable cases of slope, using the maximum likelihood estimation method. The developed technique has been applied to a practical example, and the results from the developed technique were compared to the results from the Monte Carlo simulation technique.  相似文献   

An empirical formula for friction coefficient of a perforated wall with vertical slits     

Kyung-Duck Suh  Yeul Woo KimChang-Hwan Ji 《Coastal Engineering》2011

The friction coefficient in the permeability parameter of a perforated wall has been estimated on the basis of a best fit between measured and predicted values of such hydrodynamic coefficients as reflection and transmission coefficients. In the present study, an empirical formula for the friction coefficient is proposed in terms of known variables, i.e., the porosity and thickness of the perforated wall and the water depth. This enables direct estimation of the friction coefficient without invoking a best fit procedure. To obtain the empirical formula, hydraulic experiments are carried out, the results of which are used along with other researchers' results. The proposed formula is used to predict the reflection and transmission coefficients of various types of structures including a perforated wall. The concurrence between the experimental data and calculated results is good, verifying the appropriateness of the proposed formula. It is also shown that the proposed formula can be used for irregular waves as well.  相似文献   

Mineralogical and geochemical characterization of precipitates on stream receiving acid mine water, Korea     

Eum Sik Woo  Jeong Jin Kim  Young Hun Kim  Gyo Cheol Jeong  Yun Deuk Jang  Warren A. Dick 《Environmental Earth Sciences》2013,69(7):2199-2209

Seasonal variations of water chemistry occurred in acid mine drainage receiving mine and leachate water. Sulfate and metal concentrations were low in winter but high in spring and summer. Mine waters were highly acidic (up to pH 3.4) in nature with high concentrations of manganese, copper and zinc but high electrical conductivity and sulfate in leachate. The blue and brownish yellow precipitates were formed under different chemical environments of acid mine drainage. Brownish yellow (Munsell color 7.5YR 8/12), blue (Munsell color 2.5B 9/7) and light blue (Munsell color 2.5B 9/3) precipitates deposited on the stream bottom receiving acid mine water. The brownish yellow precipitates formed in the acid mine water, whereas the blue and light blue precipitates formed in the leachate water. The brownish yellow precipitates consisted mainly of ferrihydrite, whereas the blue and light blue precipitates consisted of glaucocerinite and/or woodwardite.  相似文献   

On the planar motion in the full two-body problem with inertial symmetry   总被引：1，自引：0，他引：1  

Pamela Woo  Arun K. Misra  Mehdi Keshmiri 《Celestial Mechanics and Dynamical Astronomy》2013,117(3):263-277

Relative motion of binary asteroids, modeled as the full two-body planar problem, is studied, taking into account the shape and mass distribution of the bodies. Using the Lagrangian approach, the equations governing the motion are derived. The resulting system of four equations is nonlinear and coupled. These equations are solved numerically. In the particular case where the bodies have inertial symmetry, these equations can be reduced to a single equation, with small nonlinearity. The method of multiple scales is used to obtain a first-order solution for the reduced nonlinear equation. The solution is shown to be sufficient when compared with the numerical solution. Numerical results are provided for different example cases, including truncated-cone-shaped and peanut-shaped bodies.  相似文献   

Biomarker responses in caged rockfish (Sebastes schlegeli) from Masan Bay and Haegeumgang, South Korea     

Jung JH  Kim SJ  Lee TK  Shim WJ  Woo S  Kim DJ  Han CH 《Marine pollution bulletin》2008,57(6-12):599-606

The purpose of this study was to compare enzymatic biomarker activities in fish caged at two sites, Masan Bay (contaminated) and Haeguemgang (reference). In the present study, ethoxyresorufin O-deethylase (EROD), brain acetyl cholinesterase (bAChE), muscle acetyl cholinesterase (mAChE) and butyryl cholinesterase (mBChE) in caged rockfish (Sebastes schlegeli) were measured 0, 1, 3, 7, 14, 21 and 30 days after caging. The level of CYP1A mRNA and Protein expression was induced higher in Masan Bay at 1, 3, 7, 14 and 30 days after caging. EROD activity in the caged fish was significantly higher in Masan Bay than in Haeguemgang 3 and 7 days after caging, but not at 14 and 30 days after caging. bAChE activity was significantly inhibited at 7 and 14 days after caging in Masan Bay. However, mBChE activity was not significantly inhibited during the experiment. Taken together, the data suggest that the caged fish were exposed, at least transiently, to CYP1A inducers and ChE inhibitors, which is consistent with our previous observations.  相似文献   

Evaluation of heavy metal contamination and implication of multiple sources from Hunchun basin, northeastern China   总被引：1，自引：0，他引：1  

J.-W. Moon  H.-S. Moon  N.-C. Woo  J.-S. Hahn  J.-S. Won  Y. Song  X. Lin  Y. Zhao 《Environmental Geology》2000,39(9):1039-1052

Present concentrations and distributions of heavy metals through profiles, surface soil, and stream sediment samples in the Hunchun area, north-eastern China, were investigated to determine the elemental background values. This study also aims to characterize potentially toxic materials such as pulverized fly ash (PFA) from power stations or ash and slag from coal used domestically in urban areas, agrochemicals applied inappropriately, and urban sewage sludges from Hunchun City, as well as to ascertain the possibility of natural enrichment through site characterization by mineralogical and geochemical investigation. The distribution of contaminants in the alluvial soils (fluvisol) of this area has been influenced by several interacting factors. The parent alluvial materials from weathered products of amphiboles have made coatings such as ferrihydrite, goethite, and hematite. This natural inheritance factor is supported by the fact that the concentrations of weak acid-extractable (plant-available) heavy metals are very low, except for Fe and Mn. However, in agricultural soils and adjacent stream sediments, an anthropogenic input of Cd, Pb, Ni and Cr by agrochemicals is strongly suggested. Also, F contamination by coal combustion and the dissolution of F-bearing minerals could cause some future problems. Wide distribution and significantly high concentrations of Cd, Fe, Mn, and F in soils throughout the combination of pollutants originating from lithogenic and the anthropogenic sources pose potential problems in utilizing water resources. Received: 14 June 1999 · Accepted: 27 December 1999  相似文献   

A WIMP detector with two-phase xenon     

D. Cline  A. Curioni  A. Lamarina  G. Mannocchi  S. Otwinowski  L. Periale  R. Periale  P. Picchi  F. Pietropaolo  H. Wang  J. Woo 《Astroparticle Physics》2000,12(4):373-377

We describe an important new technique to search for WIMPs. This technique employs a method of background discrimination using double phase xenon as detector target. We describe the construction of a two-phase, 1-kg xenon detector. The detector will be installed at the underground laboratory in the Mt. Blanc tunnel, which provides a low background rate. A comparison between the sensitivity curve of our detector and the theoretical events limit from SUSY calculations is presented.  相似文献   

Antiproliferative and apoptosis-inducing potential of 3β-hydroxy-△5-steroidal congeners purified from the soft coral Dendronephthya putteri     

Thilina U.JAYAWARDENA  Won Woo LEE  I.P.Shanura FERNANDO  K.K.Asanka SANJEEWA  Lei WANG  Tee Gee LEE  Young Jin PARK  Chang-ik KO  You-Jin JEON 《中国海洋湖沼学报》2019,(4)

The exploration and identification of antiproliferative phytochemicals have received increased attention in medicinal chemistry.In particular,research focused on the toxicology of marine natural products has increased in recent years.Terpenoids,among many secondary metabolites,have been demonstrated to act as effective anticancer agents.Soft corals,a group of marine invertebrates,produce a variety of terpenoids with biofunctional properties.The current study presents the extraction,purification,and identification of sterol congeners from the soft coral Dendronephthya putteri.The method involves 50%chloro form-methanol extraction,polar column fractionation,and analy sis through GC-MS~n.Do se-dependent antiproliferative activity was observed within the sterol-rich fraction(DPCMH 2-4),which consisted of3β-hydroxy-A5-steroidal congeners.This fraction inhibited the growth of HL-60 and MCF-7 cells with IC_(50) values of 25.27±1.43 and 22.81±0.15 μg/mL,respectively.Apoptotic body formation,DNA damage,cell cycle arrest,and apoptotic cell signaling pathway activation were also observed,reinforcing the dosedependent antiproliferative and apoptosis-inducing activity of 3β-hydroxy-A5-steroidal congeners.To our knowledge,this is the first report of anticancer agent identification from the soft coral D.putteri.Based on the observations,these steroidal congeners are promising candidates for the development of anticancer drugs.  相似文献