• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.1
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• pp.1-7
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• 1993

The 1,081 soybean genotypes including 972 black soybeans and 109 other colored soybeans were collected in 197 locations from January to April, 1991. Seed chemical components of soybean collections in relation to growth characters were evaluated to survey germplasms for black soybean breeding for seed quality. Seeds of 1,081 genotypes collected were analyzed for crude protein, crude lipid, and total sugar contents. The crude protein content was averaged to 39.8% and ranged from 34.1% to 48.0%. The average crude lipid and total sugar contents were 20.1% and 10.1%, and the ranges of those were 14.1% to 23.8% and 8.3% to 12.1%, respectively. Higher crude protein content was shown in early soybean maturity group, whereas higher total sugar content was in late group. Black soybean collections with green seed embryo tended to be higher in total sugar content than those with yellow one. Black soybean oil is generally composed of about 22% oleic, 55% linoleic, 7% linolenic acid, and 16% the others.

• Magazine of the Korea Concrete Institute
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• v.7 no.1
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• pp.136-144
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• 1995

근래 양질의 하천골재가 거의 고갈상태에 직면함에 따라 쇄석골재의 사용이 보편화되고 있는 우리나라의 실정에 비추어 볼 때 골재의 화학반응에 대한 연구의 필요성이 점차 증대되고 있다. 본 연구에서는 우리나라에서 실제 쇄석골재를 생산하는 238곳 중 63곳의 시료골재를 채취하여 화학적, 광물학적, 모르터 바 분석실험을 실시하여 골재의 화학반응성을 규명하였다. 분석시험 결과 대부분의 시료골재가 화학반응성을 나타내지 않았으나 광물학적 분석에서 유해광물로 알려진 성분들이 여러 시료골재에 포함되어 있었다. 따라서 해사의 사용 등 점차 화학반응 환경이 공존하게 되면 골재의 화학반응이 일어날 가능성이 커지므로 계속적이고 심도있는 연구가 요구되고 있다.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.10a
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• pp.151-151
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• 2003

토양에 방치된 농업용 폐비닐은 거의 분해가 되지 않으며, 수분과 공기의 유통을 차단하고 토양 내 미생물들의 흐름을 막아 토양을 더욱 황폐화시키게 된다. 불법적인 소각 때는 산불의 위험에다 다이옥신, 염소 및 염화수소가스 등을 배출해 대기오염을 유발시킨다. 폐비닐을 열분해과정으로 처리하여 아주 작은 입자로 미분쇄하고 겔상태로 용융된 원료물질속으로 완전히 균일하게 혼합하여 골재로 활용하는 과정에서 가스상과 액상의 여러 가지 중간생성물질이 발생하게 되며, 농약의 살포에 의한 잔류농약 둥 인체에 유해가능한 요소들이 있을 수 있다. 본 연구에서는 개발공정이나 제품에서 인체에 영향을 미칠 수 있는 물질에 대하여 유해성을 평가하고 용응 겔 및 가스와 오일에 함유된 화학성분을 분석하였기에 보고하고자 한다 시험동물의 혈액생화학적 검사에서는 농업용 폐비닐물질 및 열분해 파생물질의 혈청 Cholesterol, 혈청 Alanine aminotranseferse와 Aspartate aminotransferse, Albumin 수치, LDH, Glucose, Uric acid, A/C 비 등의 생화학적 활성도를 측정한 결과들에서는 농업용 폐비닐물질을 투여한 시험군에서 나타난 결과와 비교하여 열분해 파생물질을 투여한 시험군에서 나타난 결과가 감소된 통계결과를 보였다. 이 결과들은 농업용 폐비닐물질을 투여한 시험군보다 열분해 파생물질을 투여한 시험군의 외부독성물질 투여에 의한 생체독성의 영향과 생체에 가해진 스트레스강도가 작았음을 의미하는 것이다. 잔류농약분석에서는 시료로부터 농약을 추출하는 용매추출과정, 시료추출물 중 공존하는 방해성분을 제거하는 정제과정, 폐비닐물질 및 열분해 파생물질 성분을 100mg/kg 이상군의 투여 후 시험동물의 부검시 모든 투여군에서 독성소견이 인정되지 않았다. 이와 같은 결과로 열분해 및 연소과정에서 발생하는 파생물질의 분석결과를 응용하여 대기오염을 방지하고 인체 유해물질을 차단하는 공해 방지 설계의 기초자료를 제안하고자 한다.

• Journal of the Korean GEO-environmental Society
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• v.11 no.11
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• pp.47-54
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• 2010

Nowadays, geosynthetics for reinforcement and protection are widely applied to the waste landfill site. Current research indicates the potential for progressive failure in geosynthetic-soil system depends on the interface shear strength governed by several intrinsic factors such as moisture, normal stress, chemical, etc. In particular, the effect of the acidity and basicity from the leachate is intensively reviewed to assess the chemical reaction mechanism of interface shear strength under the cyclic loading condition. New multi-purpose interface apparatus(M-PIA) has been manufactured and the cyclic direct shear tests using submerged geosynthetics and soils under the different chemical conditions have been performed, consequently, the thickness of interface and shear stress degradation are verified. The basic schematic of the Disturbed State Concept(DSC) is employed to estimate the shear stress degradation in the interface, then, normalized disturbed function is obtained and analyzed to describe the shear stress degradation of geosynthetic-soil interface with chemical influence factors under dynamic condition.

• Journal of the Korean GEO-environmental Society
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• v.9 no.5
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• pp.37-43
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• 2008

Inorganic injection material, which is one of the ground improvement materials, consists of cement accelerator and inorganic micro particle. The inorganic injection material is known to overcome the major limitations of water glass type improvement materials, which are leaching and accompanying strength loss. The inorganic injection material is superior in durability and strength, and environmentally friendly since leaching is prevented. In this study, the effectiveness and environment-friendliness of the MIS(Micro Injection-process System) using the inorganic injection material is compared to SGR, which uses the water glass. The performed tests were unconfined compression test, chemical resistance test, and fish poison test. The unconfined compression tests showed that the MIS results in 1.7 times higher 28 day strength compared to the SGR. In addition, the strength continually increased with time for the MIS, while it decreased for the SGR. The chemical resistance tests indicated that the rate of change in length using the MIS is 10~25 times smaller than when using the SGR. The fish poison test proved that MIS was more environmentally friendly. The analysis of chemical ingredients of leached showed that the amount of $Cr^{6+}$, Pb and Si leached from the MIS is less compared to the SGR. Accordingly, the MIS grout is more high-strength than existing SGR grout. It is excellent in shortening of construction period, structural stability of foundation and environmentally friendly. So, it is considered that it has not little the problem about groundwater pollution.

• International Journal of Highway Engineering
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• v.3 no.1 s.7
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• pp.177-184
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• 2001

A recycling agent has been manufactured on the basis of the chemical composition of reclaimed asphalt binders and virgin asphalt binders. The chemical compositions of reclaimed asphalt binders extracted from reclaimed asphalt pavements have been analyzed according to the ASTM method and the results were compared to those of virgin asphalt binder AP-3. Reclaimed asphalt binders have shown that asphaltenes was increased whereas saturates, naphthene aromatics, and polar aromatics fractions were decreased. A recycling agent made of aromatic compounds, in which its chemical composition is similar to the aromatics fraction in asphalt binders, has been produced to reduce the amount of asphaltenes in reclaimed asphalt hinders. The evaluation of the recycling agent produced was performed by testing ductility, rolling and ball softening point, penetration at $25^{\circ}C$ and viscosity at $60^{\circ}C$. It was found that, by adding the recycling agent 20% by weight to the reclaimed asphalt binders, the physical properties of reclaimed asphalt binders was recovered to the level of virgin asphalt binder AP-3.

• Journal of the Korean Society for Railway
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• v.11 no.2
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• pp.188-194
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• 2008

Brake disks for rolling stock are exposed to thermal fatigue during braking, and thermal cracks occur on surface of disks. Thermal cracks can cause serious accidents, deterioration of braking performance and increase of maintenance cost due to frequent exchange of friction materials. In this study, candidate materials with high-heat resistance were selected by searching the literature. By using cast specimens made of the candidate materials, chemical composition, crystal structure and graphite type were analyzed. In addition, friction coefficient and wear were measured and compared with values for the disk material in service. As a result, it was shown that the NiCrMo has highest tensile strength and lowest friction coefficient and the disk material in service has the most stable friction characteristics.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.3
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• pp.185-194
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• 2022

Coffee is one of the most consumed beverages in the world and is the second largest traded commodity after petroleum. Due to the great demand of this product, large amounts of waste is generated in the coffee industry, which are toxic and represent serious environmental problems. This study aims to study the possibility of recycling spent coffee grounds (SCG) as a mineral admixture by replacing the cement in the manufacturing of concrete. To recycle the coffee g rounds, the SCG was dried to remove moisture and fired in a kiln at 850 ℃ for 8 hours. Carbonized coffee grounds are produced as coffee grounds ash (CGA) through ball mill grinding. The chemical composition of the prepared coffee grounds ash was investigated using X-ray fluorescence (XFR). According to the chemical composition analysis, the major elements of coffee grounds ash are K₂O(51.74 %), CaO(15.92 %), P₂O₅(14.39 %), MgO(7.74 %) and SO₃(6.89 %), with small amounts of F₂O₃(0.66 %), SiO₂(0.59 %) and Al₂O₃(0.31 %) content. To evaluate quality and mechanical properties, substitutions of 5, 10, and 15 wt.% of coffee grounds ash (CGA) were tested. From the quality test results, the 28-day activity index of CGA5 reached 80 %, and the flow value ratio reached 96 %, which is comparable to the minimum requirement for second-grade FA. From the test results of the mortar, the optimal results have been found in specimens with 5 wt-% coffee grounds ash, showing good mechanical and physical properties.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.1
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• pp.37-42
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• 2009

This experiment was conducted to investigate the effect of cattle manure application on macro contents change in pasture. The treatment consisted of T1: 100% chemical fertilizer (CF 100%), T2: 50% CF+50% cattle manure (CM), T3: 25% CF+75% CM, T4: 100% CM 100%, T5: 100% CM(1st year (yr.) +100% CF (2nd yr.)+100% CM (3rd yr.), T6: 100% CM (1st yr.)+100% CF (2nd yr.)+100% CF (3rd yr.). The highest substitution effect of chemical fertilizer with cattle manure indicated by the highest yield of 11,169 kg/ha was obtained from the application of 100% CM (1 yr.) + 100% CF (2 yr.). The forage yield of plots applied with 100% CM (1 yr.) + 100% CF(2 yr.) was only 4% more than the yield of plots applied with 100% CM. It was only 3% less than the yield of plots applied with 100% CF. In this study, cattle manure application recorded slightly lower forage dry matter (DM) yield than 100% CF application but they were statistically comparable on the third year of production. The all treatments have narrow range of P, K, Ca, Mg and Na contents $0.25{\sim}0.32%,\;3.08{\sim}3.71%,\;0.42{\sim}0.55%,\;0.21{\sim}0.38%$ and $0.08{\sim}0.15%$.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.6
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• pp.180-188
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• 2020

To replace Japanese coal ash used in the domestic cement production and to recycle large quantities of domestic pond ash, it is essential to develop the technologies for quality control of cement by using the domestic pond ash. Thus, in this study, the feasibility of using the pond ash as a raw material for cement was investigated through chemical composition and microstructure analysis. As a result, most of the domestic pond ash contained slightly more Fe2O3, chloride, and unburned carbon contents than Japanese coal ash. In particular, the contents of chloride were considerably low in the pond ash that was transferred to fresh water or collected from surface of landfill area. However, since circulating fluidized bed boiler coal ash had relatively high SO3 contents causing durability problems of cement, it was not suitable for use as a raw material for cement. Thus, to replace Japanese coal ash with the domestic pond ash, it is necessary to introduce the adjustment of mixture proportion of cement raw materials and the process of removing chloride in the pond ash.