• Journal of Korean Society on Water Environment
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• v.33 no.4
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• pp.460-473
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• 2017

In order to certificate the contamination assessment of heavy metals in surface sediments from the Nakdong river. Surface sediments were collected of 24 sampling sites (main 14st., tributary 10st.) and analyzed for grain size heavy metals contents. Study area mainly composed of sand (avg. 94.1%) and mean grain size was $1.46{\Phi}$ on average. Heavy metals contents (avg. Al: 12.5%, Zn; 74.4, Cr: 45.3, Li: 26.0, Pb: 17.1, Ni: 10.5, Cu: 7.8, Cd: 0.22 mg/kg) were relatively high contents in the composed of fine sediments. In addition, the results of pearson's correlation coefficient showed that most heavy metals and grain size (silt and clay) were highly correlated. The contents of Zn (6st.) and Ni (1st.) evaluated as moderately polluted, Zn (6st.) evaluated as LEL when compared with sediment quality standard of USEPA and Ontario sediment quality guidelines. Most heavy metals contents were I levels that dose not affected the benthos when compared with sediment pollution evaluation standard of NIER. The results of EX, EF, Igeo and CF showed the contents of Zn, Pb and Cd exceed the background contents and distributing of anthropogenic pollution and evaluated as moderately polluted level. And Nm-08 were relatively high level of contamination in the study area. However as results of PLI (less than 1), all sampling sites were evaluated unpolluted level.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.163-163
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• 2017

철강재는 대량 생산이 가능하여 경제성이 뛰어나고 기계적 성질도 우수하여 다양한 산업 분야에서 널리 사용되고 있다. 그러나 철강재는 부식 환경에 취약하기 때문에 그 용도에 따라 다양한 내식성을 부여하는 표면처리를 적용하고 있다. 이러한 철강재에 대한 내식성 표면처리로는 용융아연도금(HDG)과 용융알루미늄도금(HDA)이 우수한 내식성과 다양한 특성으로 널리 사용되고 있으며 아연과 알루미늄을 접목시킨 갈바륨(GL)도금 또한 우수한 내식성 코팅으로 알려져 있다. 또한 최근에는 기존 용융아연도금에 알루미늄(Al) 과 마그네슘(Mg)을 첨가한 3원계 도금강판이 개발되어 기존 용융도금강판 대비 고내식 코팅으로 알려져 있으며 그 적용은 점차 확대되고 있는 추세이다. 일반적으로 이와 같은 강판소재의 내식성 평가에 대해서는 실제 사용할 환경에 폭로하여 비교-시험 하는 것이 가장 확실하고 신뢰도가 높은 방법이다. 그러나 이러한 방법은 경우에 따라 수년에서 수십년에 이르는 장시간이 소요된다. 그러므로 이 방법을 대체하기 위한 각종 가속적 부식 시험들이 널리 적용되고 있다. 즉, 그 목적이나 용도에 따라 염수분무(SST), 침지(Immersion) 및 전기화학적 분극(Polarization) 등 실내에서 부식 시험 하는 방법이 사용되고 있다. 한편, 이러한 부식 가속 시험들은 실제 외부에서 폭로 시험한 결과와의 상관성이 불명확한 경우가 많아 종종 해석에 어려움을 갖고 있는 실정이다. 또한 이 시험 방법들은 동일 재료를 시험하더라도 시험방법의 차이에 따라 부식요인이나 해석방법이 다르므로 인해 그 내식성 결과가 다르게 나타날 수 있다. 그 중 시험목적에 따라 전기화학적 분극 또는 임피던스 분광법(EIS)과 건조 및 습윤 등의 부식 환경 인자들을 적용한 복합부식시험(CCT) 방법은 근사한 대안으로 주목받고 있다. 하지만 이들 시험 또한 실제 부식 환경과는 여러 환경 및 요인들이 다르기 때문에 그 시험방법에 따라 목적하는 시험 결과가 상이하게 나타날 수 있어 해석-평가 하기에 종종 곤란을 갖는다. 이에 따라 최근에는 재현성이 우수하고 실제 부식 환경을 유사하게 모사할 수 있는 내식성 시험과 해석-평가에 대한 내용이 주요한 과제로 사료되고 있다. 본 연구에서는 다양한 내식성 코팅 강판소재들에 대하여 염수분무(SST), 복합부식(CCT), 갈바닉 시험, EIS 시험을 통하여 부식시험 종류 및 시험 환경, 코팅 소재 별 부식경향을 비교-분석하고자 하였다. 또한 이들 부식 진행과정에서는 미세구조관찰(SEM), 결정구조 분석(XRD) 및 원소조성 분석(EPMA)을 통해 다양한 조건에 따른 강판소재들의 부식경향을 비교-평가하고, 실제 환경과의 상관성 및 가속관계를 도출하고자 하였다.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.2
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• pp.70-77
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• 2012

The Ladle Furnace Slag, about 20% of the electric arc furnace slag, has high content of free CaO and free MgO, which generates the expansion collapse by hydration reaction. Although many researchers have been endeavoring to recycle the EAF reducing slag in construction fields, there is not found the effective recycling method up to now. However, the LFS(Ladle Furnace Slag) contains mineral composition of the system of calcium aluminate with high-reactivity. Therefore, it is possible to developed the quick setting property and the high strength at the early age by the rapid cooling. This study aimed to check the reactive minerals and predict the reactivity with water on the LFS discharged from different steel product plants. The test results show that many types of LFS has hydration reactivity and can use in construction field as a inorganic binder with the rapid setting property.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.1
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• pp.38-49
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• 1986

In order to improve effectiveness of rhizobia-legume symbiotic nitrogen fixation, ecological and physiological characteristics of indigenous rhizobia distributed in Korea soil, that is, the effects of soybean cultivation, physico-chemical properties and climate on the population of indigenous rhizobia and other soil microbes were investigated. The results were summarized as follows: The population of indigenous rhizobia were ranged from $5.1{\times}10^4$ cells to $196.8{\times}10^4$ cells per gram of soil in soybean cultivated soils but from $1.6{\times}10^4$ cells to $78.6{\times}10^4$ cells per gram of soil in soybean un-cultivated soils sampled from 9 different agro-climate zone. The highest population was observed in a soybean cultivated loamy soil from southern part of Korea. The content of available phosphate, exchangeable Ca, Mg, Cu, and B in soil were positively correlated but active Fe, exchangeable Al, Na, and $SO_4$ were inversely correlated to the population of indigenous rhizobia. The inverse relationship was observed between the number of indigenous rhizobia and actinomycetes.

• Korean Journal of Ecology and Environment
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• v.41 no.2
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• pp.155-165
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• 2008

The purpose of this study was to evaluate the ecosystem of Yeongsan Lake using physical, chemical, and biological indicators. We evaluated the integrative ecosystem health using Lentie Ecosystem Health Assessment (LEHA) model, Qualitative Health Evaluation Index (QHEI) model, and chemical water quality. The models of LEHA and QHEI were modified as 10 and 7 metries attributes, respectively. Also, we analyzed bioaccumulation of total mercury on various fish tissues by method of U.S. EPA 7473 using Direct Mercury Analyzer (Model DMA-80). Model values of LEHA model averaged 19 (range: $14{\sim}26$, n=15), which indicated a "poor" condition, and had slightly spatial variations. Values of the QHEI in the all sites averaged 72, which were judged as a "fair" to "good" condition. The QHEI values varied from 48 (fair condition) to 99 (good condition) and showed large longitudinal gradients between the upper and lower reach. Conductivity and salinity were increased from the up-lake to downlake reach. Analysis of total mercury in fish tissues showed that levels of total Hg ranged between 0.002 and $0.087\;mg\;L^{-1}$ depending on the types of tissues. Overall, the ecosystem health in the Yeongsan Lake was judged as a "poor" and the effects of bioaccumulation on the fish tissues were minor. Therefore, it is necessary to keep an efficient management for the lake environment to maintain their ecological health.

• The Journal of the Petrological Society of Korea
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• v.6 no.1
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• pp.1-18
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• 1997

Andesitic pyroclastics and lava flows are deposited as a part of composite volcanoes by Cretaceous volcanic activity in Geojae Island, off the coast of Korea. The andesitic pyroclastics are composed of tuff breccia and lapilli tuff minor intercalated tuff. Lava flows are divided into dense and porphyritic andesite containing phenocrysts of plagioclase, pyroxene, and/or hornblende. The andesitic rocks represent charactersitcs of carc-alkaline BAR association with basalt, basaltic andesite, andesite, and dacite to rhyolite. Major element variations of the volcanic rocks show that $Al_2O_3$, total FeO, CaO, MgO and $TiO_2$ decrease with increasing $SiO_2$ but $K_2O$ and total alkalis increase, and represent differntiation trend of calc-alkaline rock series. In spider diagram, contents of Sr, K, Rb, Ba, and Th are relatively high, but contents of Nb, P, Ti and Cr are low. These petrochemcial characteristics are similar to those of rocks from island arc or continental margein related to plate subduction. Chondrite-normalized REE patterns of volcanic rocks are paralle to subparallel, with LREE enriched than HREE, and show gradual increase of negative Eu anomaly from basalt to dacite and rhyolite, suggesting comagmatic fractional crystallization with minor effects of assimilation and magma mixing. Andesitic rocks are assumed medium-K orogenic andesites that formed in the tectomagmatic environment of subduction zone under normal continental margin arc.

• 한국해양학회지
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• v.7 no.1
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• pp.24-45
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• 1972

The Han River is an important water source in Seoul and neighbouring districts, for public and industrial supply, and for agriculture and fishery. Nowadays, more than six million inhabitants are supplied withe water from this river. The total length of the river is 470km, and has 17 10$\^$9/㎥ an average annual flow. The hydrographic characteristics at Seoul are 653㎥/sec in an average flow, 4,608㎥/sec in the maximum average flow, and 201㎥/sec in the minimum average flow. These are influenced in some degree by snowmelt in early spring, and greatly by the flood during summer. For the pollution problems, the periods of low flow are critical ones. As a rule they occur around the months November through June. Nowadays, most of the sewage from towns and industries is discharged untreated. Apart from domestic and industrial sewages, there are some discharges of mineral matter by mines in the upriver region. In general, water quality of the Han River is kept very clean and healthy until Kwangnaru of the upper region of Seoul. A large pollution, however, is received in the downstream by the domestic and industrial sewages of Seoul. It can be seen that dissolved oxygen, COD and BOD$\sub$5/ diminish markedly, and the intensity of almost every water parameter of the river continues to increase. Comparison of the figures for 1971 derived from a sampling point 40km downstream of Kwangnaru leads to the conclusion that hardness, Ca and Mg were no changed; alkalinity, Si and soluble- Fe were slightly increased; CO$\sub$2/, acidity, Cl, NO$\sub$2/-N, Cu, Zn and Al were increased in 2 and 3 times; total residue, total ignitious residue, COD, BOD$\sub$5/, NH$\sub$4/-N, PO$\sub$4/-P, Mn, Pb and total-Fe were increased in 4 to 7 times; and SO$\sub$4/, particulate-Fe and Cd were increased in 10 to 11 times. On the other hand, coliforms were increased in 650 times; fecal coliforms in 365 times; enterococci and total plate counts in 30 times, respectively. In view points of water quality standards, the down Han River water is now leveling out in Cd, coliforms and fecal coliforms for the agricultural use; in dissolved oxygen and some trace elements (Cu, Zn, Pb and Cd) for the fishery use; in ammonia, COD, BOD$\sub$5/, and Cd for the drinking use.

• CELLMED
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• v.11 no.3
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• pp.13.1-13.9
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• 2021

Background and Objective: Nux-vomica based traditional Unani formulation, Habb-e-Azaraqi (HAZ) is an important drug used by Unani physicians since several decades. It possesses Muqawwi-i-A'sab (nervine tonic), Muharrik-i-A'sab (nervine stimulant) properties and is an effective treatment option for diseases like Laqwa (facial palsy), Falij (paralysis), Niqris (gout) and Waja'al-Mafasil (arthritis) etc. The aim of the study is to access and provide information of HAZ for its TLC, HPTLC Fingerprinting defining its clear qualitative perspective and acute oral toxicity evaluation for its safety assessment which was not done earlier, thus contributing in the field of research. Materials and Methods: The chief ingredient, nux-vomica was detoxified as per method mentioned in Unani Pharmacopeia before its use in formulation. TLC and HPTLC was developed under four detection system i.e., UV 366nm, UV 254nm, exposure to iodine vapours and after derivatization with anisaldehyde sulphuric acid. Acute toxicity studies were performed as per OECD Guidelines 425 at a limit dose of 2000 mg/kg. Observations were done for signs of toxicity, body weight, and feed consumption at regular intervals followed by haematological and biochemistry evaluation. Results: The generated data proved the authenticity and established the TLC and HPTLC profile of the formulation. Acute toxicity revealed no significant differences in HAZ-treated animals with respect to body weight gain, feed consumption, haematology, clinical biochemistry evaluation. No significant gross pathological observation was noticed in necropsy. Conclusion: Data of the present study is substantial and scientific proof of HAZ in terms of standardization and toxicity study that can be utilize in future research activities.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.1
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• pp.129-135
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• 2012

This study was to investigate the heavy metal content of 55 commercial salts in the Seoul area. There were 22 types of solar sea salt, 17 types of processed salt and 16 types of reworked salt. Looked at another way, there were 22 types of domestic salt and 33 types of salt imported from France, the U.S., Japan, Australia, New Zealand, and Argentina. The samples were measured using both a mercury analyzer and an Inductively-Coupled Plasma Optical Emission Spectrometer (ICP-OES). The average heavy metal contents for commercial salts were Pb $0.281{\pm}0.344$, Cd $0.035{\pm}0.221$, Cr $0.364{\pm}0.635$, Cu $0.182{\pm}0.313$, As $0.046{\pm}0.062$, Ni $0.155{\pm}0.247$, Al $5.753{\pm}10.746$, Co $0.028{\pm}0.211$ and Hg $0.001{\pm}0.001$ mg/kg. The leads were detected highly in solar sea salt rather than in processed salt or reworked salt. Also chrome, arsenic and nickel were found more in processed salt. There were large differences in aluminum content between imported solar sea salt and processed salt. Aluminum was highly detected in French products, showing that salt can be affected by regional differences. The weekly average intakes of Pb, Cd, Cr, Cu, and Hg from commercial salt were 1.652% (0.000~6.754), 0.372% (0.000~7.214), 3.177% (0.000~26.279), 0.008% (0.001~0.049), and 0.031% (0.000~0.094) respectively compared with Provisional Tolerable Weekly Intakes established by the Joint FAO/WHO Expert Committee for the evaluation of food safety. The content of heavy metals from commercial salts was determined to be at safe levels.

• Applied Microscopy
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• v.33 no.2
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• pp.145-154
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• 2003

The present study was designed to demonstrate ionic zinc in the rat nasal mucosa by means of zinc selenium autometallography ($ZnSe^{AMG}$). Rats were given sodium selenide either intraperitoneally (i.p) or intranasally (i.n). Prior to the i.n. administration the rats were anesthetized with pentobarbital sodium (30 mg/kg, i.p.). A thin plastic tube coupled to a Hamilton syringe was then inserted into the right nostril and $10{\mu}l$ of the solution was instilled. For the i.p. administration non-anesthetized rats were given $100{\mu}l$ of the sodium selenide solution (10 mg/kg). Control rats were instilled with saline. After 2 hrs survival, the rats were anaesthetized and transcardially perfused with 3% glutaraldehyde. The olfactory area was removed and put into same fixative. The nose was then sectioned ($30{\mu}m$) horizontally, autometallography (AMG) was performed according to Danscher et al. (1997). After silver enhancement, fine AMG grains were scattered in the whole length of the olfactory epithelium containing olfactory receptor neurons, sustentacular and basal cells. However, much higher concentration of the AMG grains occupied near the surface and in the basal region of the olfactory epithelium. Both groups of i.p. and i.n. administration showed almost same level in the concentration of the AMG grains. In i.n. group, few AMG grains were also found in olfactory nerves of the lamina propria, suggesting zinc transport into the olfactory bulb via olfactory axons. At the electron microscopic level, the AMG grains were most entirely found in the supporting cells of the olfactory epithelium, and they were mostly localized in lysosome-like organelles. The i.n. group showed various signs of tissue damage of the olfactory mucosa, where dense concentration of AMG grains were localized at crystalloid structures. The present study demonstrated dense population of ionic zinc in the rat olfactory epithelium. zinc may play a role in the olfactory functioin and in the pathogenesis of the neurodegerative disorders affecting nose.