• Korean journal of applied entomology
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• v.36 no.3
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• pp.277-282
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• 1997

Chemosterilant effect of chlorpyrifos-methyl (CPM) on the beet armyworm, Spodoptera e.rigua (Hubner) was investigated, using topical application. Egg fecundity and fertility were analyzed in the adults reared from the fifth instar larvae which were treated with sublethal doses of CPM. Though CPM reduced fecundity a little, it gave significant negative effect on egg fertility in a dose-dependent manner. Genetic analysis was performed by reciprocal crosses between treated (100 Wgllarva) and untreated individuals and showed a dominant lethal effect of CPM on egg fecundity and fertility. This results indicate that chlorpyrifos-methyl may act as a chemosterilant as well as a well-known neurotoxicant, and suggest that it can be used in genetic control program.

• Journal of the Korean Society of Tobacco Science
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• v.32 no.1
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• pp.41-54
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• 2010

담배 주류연은 수천가지 종류의 다양한 형태의 화학물질로 구성되어있고, 이들 화학물질의 대부분은 극히 미량의 농도로 존재하는 것으로 알려져 있다(Green and Rodgman, 1996). 담배연기 속에서 발암물질로서는 poly cyclic aromatic hydrycarbon (PAHs) 류인 B(a)P를 최초로 보고된 이후, 현재까지 69종의 화합물이 담배연기중의 발암물질로서 알려졌으며, 여기에는 9종의 PAHs 그리고 4종의 aromatic amine, nitrosoamines 및 aldehydes 그리고 다른 무기 및 유기 화합물들을 포함된다. 또한 담배 주류연에는 여러 화학물질들에 의해 유발된 생물학적 독성을 상당히 감소시키는 것으로 확인된 성분들이 존재하는 것으로 알려져 있다. 이러한 담배연기 중에 존재하는 항 발암성 효과를 나타내는 성분들의 작용 메카니즘은 발암성 물질 또는 발암성 물질의 대사산물들과 반응을 하거나, 불활성화 시키거나, 세포 구성 물질들과의 반응에서 서로 경쟁하거나, 또는 발암성의 흡수를 간섭함으로서 발암성 효과를 없애거나 또는 감소시키는 것으로 생각된다. 여러 연구자들은 담배연기 응축물에서 종양 성장의 억제 작용을 하는 성분들이 존재하는 것으로 주장 하고 있다.(Hoffmann and Griffin, 1958; Fall et al., 1964; Homburger and Tregier, 1965). 담배 연기 중에는 발암성을 나타내는 성분들과 함께 항 발암성 및 항 돌연변이성 효과를 나타내는 성분들이 존재한다는 것이 다양한 생물학적 평가 연구들에 의해 증명되었다(Slaga and DiGivanni, 1984; Fay et al., 1984; Green and Rodgman, 1996).

• Economic and Environmental Geology
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• v.27 no.5
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• pp.459-467
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• 1994

The Gadaeri granite near Ulsan mine is an oval-shape isolated granitic body, and is genetically related to the iron-tungsten mineralization. The Gadaeri granite exhibits calc-alkaline and I-type characteristics, and generally shows the micrographic texture which indicates the shallow depth of emplacement. Consideration of the stratigraphic thickness of Ulsan formation and minimum-melt compositions suggests that the bulk magma crystallized at pressure of 0.5~2.0 kbar under water saturated condition. The evolutionary trend observed in the studied rocks represents that feldspar fractional crystallization has been a major magmatic process at the Gadaeri granite pluton. Different chemical characteristics between the Gadaeri and the Masan-Kimhae granites cannot be explained by fractional crystallization or different degrees of partial melting, and it reflects that the magma source for Gadaeri granite was different from that of the Masan and Kimhae granites.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.237-240
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• 2000

서울시 암반 지하수의 수리지구화학 및 오염 특성을 토지 이용 특성과 관련하여 시.공간적 측면에서 체계적으로 고찰하고자 3년간에 걸친 모니터링을 수행하고 있다. 본 논문에서는 1차년도 취득 자료에 대한 예비 고찰 결과를 소개한다. 서울시 암반 지하수의수질 유형은 Ca-HCO$_3$ 유형으로부터 Ca-Cl(-NO$_3$) 유형에 걸쳐 폭넓게 분포한다. 서울시 동부 지역 지하수의 경우, 중랑천을 중심으로 상류에서 하류 지역으로 가면서 용존고체함량(TDS)이 높아지는 경향이 있다. K, Ca, Mg 등 주요 양이온과 Ba, Fe, Sr 등 미량원소도 유사한 공간적 분포 특성을 보여준다. 이러한 수질 항목은 대체적으로 지하수 유동에 수반된 수/암 반응의 증가를 잘 반영하는 것으로 해석된다. 반면, NO$_3$, Cl 등 음이온의 변화는 다소 불규칙하여 지역적인 토지이용 특성과 관련한 오염 요인의 기여를 반영한다. 한편, 도시 특성에 따라 서울시 암반 지하수의 수질특성을 전반적으로 고찰한 결과, 외곽의 비오염 지역에 비하여 중심부의 교통혼잡 지역, 남서부의 공단 지역, 서부와 남부의 농업 지역에서 뚜렷한 수질 저하를 보여주었다. 이러한 경향은 특히 Na, Cl, NO$_3$, SO$_4$, Ni, Pb, Se 등의 수질 항목에서 뚜렷하게 나타난다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.5
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• pp.207-215
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• 2010

This study was carried out for the purpose of obtaining the basic data for identifying the origin of amethyst. For this, the three dimensional shapes of inclusions contained in various amethyst were observed with Stereo Zoom microscope. The shape and chemical composition of cross section of solid inclusion and the chemical composition of evaporite were investigated by SEM-EDS. The evaporite is made from evaporating of liquid inclusion which is flowed out of amethyst sample by decompressing. Lastly, The trace mineral composition of amethyst was investigated by ICP-AES after digesting the amethyst sample with HF-$H_2SO_4$ solution.

• Journal of the Korean Chemical Society
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• v.51 no.6
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• pp.560-568
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• 2007

The aim of this study is to investigate the terminology of chemically unclear ‘heavy metals' which were expressed in the Korean secondary science textbook in terms of the definition, the type and the meaning. Initial results showed that six of ‘Chemistry I' textbooks among these texts defined a heavy metal with the density and described it as a metal which is hazardous and continuously accumulated in the human body. Specifically, cadmium, lead and mercury were presented as examples of the hazardous metal in all of the eight textbooks but non-metals such as arsenic and absolutely essential metals including chrome, manganese, iron, cobalt, nickel and copper were also given in the texts. Most of the texts described the hazardousness and toxicity of the metal too simple to understand the mechanism of its intoxication despite considering all of the factors including its oxidation state, residual amount and reactivity with biomolecules of the human body. Such an ambiguous definition and explanation may excluded in the textbook because the chemically undefined chemical vocabulary leads students to cause an alternative conception of the heavy metal, which means that the metal could be identical with toxins.

• The Journal of the Petrological Society of Korea
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• v.27 no.3
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• pp.121-138
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• 2018

We have examined the petrotectonic setting and magmatic evolution from petrochemical characteristics of major and trace elements for the Cretaceous volcanic rocks in and around the Mireukdo Island. The volcanic rocks, can be devided into Jusasan, Unmunsa, Yokji and Saryang subgroups on the ascending order, are classified as basalt, basaltic andesite, andesite, dacite and rhyolite on TAS diagram. Petrochemical data show that the rocks are calc-alkaline series, and suggest that erupted earlier medium-K series and later high-K series. The volcanic rocks provide a case in which the calc-alkaline magma are formed, not only from separate protoliths, but following separate paths from source to surface. Earlier and later subgroups take different paths to the surface respectively, and are emplaced in the shallow crust as a series of discrete magma chambers through the volcanic processes. After emplacement, each chamber evolves indepently through fractional crystallization with a little assimilation of wall rock. The volcanic rocks have close petrotectonic affinities with orogenic suite and subduction-related volcanic arc. The rhyolitic magma can be derived from calc-alkaline andesitic magma by fractional crystallization with crustal assimilation, which may be derived from a partial melt of peridotite in the upper mantle.

• Journal of the Mineralogical Society of Korea
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• v.15 no.1
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• pp.33-43
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• 2002

Mineral composition and chemical properties of Hwangto (reddish residual soil) that used in feeding of cattles at Iksan, Jeollabuk-do, Korea were examined according to particle size separation such as gravel, sand, silt, coarse clay and fine clay. Mineral composition analyses reveal that gravel and sand are mainly composed of quartz and feldspars and that kaolin mineral and illite are dominant in clay and silt. Iron oxides are mainly included in fine clay. According to chemical analyses of major elements, Al, Fe and $H_2O$ contents are increased with decreasing of particle size. This trend well agrees with increase of clay minerals in smaller particles, Chemical analyses of trace elements indicate that contents of Zn, Rb, Sr, Ba, Pb significantly differ with particle sizes. Ba and Sr are included in feldspars since these elements are abundant in sand containing abundant feldspars. Pb and Sm are abundant in sample before particle size separation, but the contents are significantly decreased after separation. Therefore, most of these elements appear to be existed as removable phase. Nb, La, Th, Ce are more abundant in silt. The contents of all the other trace elements tend to be increased in smaller particles containing more clay minerals. The contents of changeable cations and teachable elements in acid and alkali solutions are high in clay samples. All the above results indicate that using the portion of smaller particle of Hwangto for livestock feed rather than bulk Hwangto can improve cation exchangeable capacity, ion leaching capacity and sorption properties.

• Journal of the Korean Chemical Society
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• v.45 no.4
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• pp.304-311
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• 2001

A study has been carried out on the extraction chromatographic separation of fission products from spent pressurized water reactor (PWR) fuels for inductively coupled plasma atomic emission spectrometric analysis. Impregnation capacity of tri-n-butyl phosphate (TBP), which is well known as an extractant in the field of uranium separation from various nuclear grade materials, on Amberlite XAD polymeric macroporous support materials was measured. Amberlite XAD-16 of which the surface area is the highest was selected as a support material because its TBP impregnation capacity was the largest in Amberlite XADs. Sorption behaviour of this TBP impregnated resin was investigated for the fission product elements using acidic solutions simulated for dissolver solutions of spent PWR fuels. The parameters affecting the performance of the separation system were optimized. The fission product elements studied excluding Pd and Ru were quantitatively recovered with the precision of less than 3.1%.

• The Journal of the Petrological Society of Korea
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• v.14 no.3 s.41
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• pp.127-140
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• 2005

The Samyuri area of Jeoksang-myeon, Muju-gun at the Middle Yeongnam Massif consists of granitic gneiss, porphyroblastic gneiss and leucocratic gneiss, which correspond to Precambrian Wonnam Series. Here we discuss a geochemical implication of the data based on major element composition, trace element, rare earth element (REE), Sm-Nd and Rb-Sr isotope systematics of the boring cores in the granite gneiss area. The boring cores are granitic gneiss (including biotite gneiss) and amphibolite. The major and trace element compositions of granitic gneiss and amphibolite suggest that the protolith belongs to TTG (Tonalite-Trondhjemite-Granodiorite) and tholeiitic series, respectively. Chondrte-normalized REE patterns vary in LREE, HREE and Eu anomalies. The granitic gneiss and amphibolite have Sm-Nd whole rock age of $2,026{\pm}230(2{\sigma})$ Ma with an initial Nd isotopic ratio of $0.50979{\pm}0.00028(2{\sigma})$ (initial ${\epsilon}_{Nd}=-4.4$), which suggests that the source material was derived from old crustal material. Particularly, this initial ${\epsilon}$ Nd value belongs to the range of the geochemical evolution of Archean basement in North-China Craton, and also corresponds to the initial Nd isotope evolution line by Lee et al. (2005). In addition, chondrite-normalized REE pattern and initial Nd value of amphibolite are very similar to those of juvenile magma in crustal formation process.