• The Journal of Natural Sciences
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• v.8 no.2
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• pp.119-127
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• 1996

The effect of sodium hydroxide treatment on some physicochemical properties of zeolite mordenite mineral was studied with chemical analyses, powder X-ray diffraction, thermal analyses, infrared analysis, measurement of carbon dioxide adsorption and gas chromatography. Mordenite mineral from tuffaceous rocks in Yeongil and Wolsung area was used as a starting material and treated with 0.1-5N NaOH aqueous solution at about $95^{\circ}C$ in the water bath for three hours.At the concentration of sodium hydroxide below 0.5N, all chemical compositions in the tuff were virtually insoluble and the mordenite structure did not change. At the concentration above 1N, the chemical compositions such as silica, alumina, etc., were dissolved. The dissolution ratio of silica was lager than that of alumina, and the ratio of silica to alumina in the tuff decreased sharply in the concentration range of 2 to 3N. Intensity of X-ray diffraction peak of mordenite (202) plane and the adsorbed amount of carbon dioxide also decreased with the increasing concentration of sodium hydroxide above 1N. These decreases corresponded to the degree of mordenite structure collapsed.The separation of gas chromatography of nitrogen, oxygen and carbon monoxide was not affected by the sodium hydroxide treatment, but elution peaks of methane and krypton tended to be broadened and their retention time was shortened. The elution peaks of both methane and krypton tended to be overlapped with those of nitrogen and oxygen.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.7
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• pp.731-737
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• 2006

Four well-characterized soils collected from A- and B-horizon in the Department of Energy Oak Ridge Reservation in USA, mainly distributed with Inceptisol(Inc) and Ultisol(Ult) soils, were used in this work. The bioaccessibility of arsenic as well as oxidation phenomena of As(III) was investigated with soils spiked with As(III) and As(V) using a physiologically based extraction test(PBET) at pH 1.5 and 1:100 soil to solution ratio. Also effect of aging time on the bioaccessibility of arsenic was investigated over the 6 months. After 48 hours(fresh) contacting As(V) solution with soils, all soils rapidly and strongly sequestrated As(V), especially Ult-B. However, little sequestration was observed after 3-months. When As(III) was spiked on the same soils, a great portion of As(III) was oxidized to As(V) after 48 hrs, especially Inc-A and Ult-A soils, which is strongly related with Mn content in soils. By using As(III)-spiked soils, much reduced bioaccessibility as total arsenic was observed from Inc-B and Ult-B soils over the 6 months aging time compared to that from Inc-A and Ult-A soils. This result can be explained by the continuous sequestration of As(V), produced from oxidation of As(III), onto Inc-B and Ult-B soils having much amount of iron. The trend of As(III) sequestration over six months aging time was quite similar with that of As(V) sequestration.

• Korean journal of food and cookery science
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• v.21 no.6 s.90
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• pp.919-926
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• 2005

The effects of the addition of germinated whole soy flour on dough and noodle characteristics were investigated in this study. The soybeans were germinated for 12 hours at $20^{\circ}C$ and ground to 60 mesh. With increasing soybean flour addition up to $16\%$, the RVA viscograph and mixograph properties were significantly decreased both with and without the addition of $3\%$ salt(p<0.05). The width and length extensibility were increased with increasing whole soy flour addition up to $8\%$ after which they decreased. The addition of the whole soy flour turned the color of the wet and cooked noodle a little darkish and greenish yellow. The hardness and gumminess of wet noodle increased with increasing whole soy flour amount, while those of cooked noodle gradually decreased. Sensory evaluation showed that addition of tile whole soy flour significantly increased the savory flavor and yellowish color of cooked noodle.

• Korean Journal of Food Science and Technology
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• v.51 no.3
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• pp.237-242
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• 2019

The purpose of this study was to investigate the optimal amount of alkaline reagent (0.2 or 0.4%) and rice flour (10-40%) for noodle and supplementation, and compare quality characteristics with those of wheat noodles. Texture properties, pH, tension profiles, and cooking quality of noodles supplemented with rice flour and alkaline reagent were measured. Wheat noodles with 0.4% alkaline reagent added displayed increased b values (Hunter's color), pH, hardness, chewiness, tension profiles, and turbidity, and decreased L, and a values, gumminess, weight, and water absorption compared to wheat noodles with 0.2% alkaline reagent added. Hardness and springiness of wheat noodles with 0.4% alkaline reagent added were 35.2 and 0.0118 N, respectively. These values for rice doodles with 0.4% alkaline reagent and 20% rice flour were similar (36.3, 0.0117 N, respectively). This suggests that addition of 0.4% alkaline reagent and 20% rice flour may be the optimal parameters for producing rice noodle.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.6
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• pp.524-530
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• 1993

The experiment was carried out to investigate the changes in physicochemical properties of milled rice harvested in different year and stored for four to sixty four months. The fat acidity of milled rice increased sharply from four to sixteen months storage, and after then it was increased slowly to sixty four months. Amylose, magnesium, potassium content, and K/Mg ratio of milled rice were not changed by storage duration. Water absorption rates of milled rice at 21$^{\circ}C$ and 77$^{\circ}C$, and alkali digestion value were increased by longer storage duration. Difference of water absorption rate between rice samples was greater during initial forty minutes after soaking at 21$^{\circ}C$ and with longer the soaking time at 77$^{\circ}C$. Shorter gel length of rice flour was found with prolonged storage duration, while peak, minimum, cool, breakdown and setback viscosity of gelatinized rice flour on amylograph were increased along with increasing the storage duration. The volume expansion rate during cooking and degree of iodine coloration of cooking water were higher in the longer stored rice compared with shorter one, and the amount of soluble solid in cooking water was significantly decreased in rice stored longer period.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.3
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• pp.226-231
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• 1994

This experiment was conducted to evaluate the effect of coated urea complex fertilizer(CUC) on the growth and quality of rice in high-ridged dry seeding and infant -seedling machine transplanting on clay loam and sandy loam in Milyang, Korea, 1993. The CUC level applicated was 100 %, 80 %, 60% and 40% to standard application amount of fertilizer. Results obtained were as follows : 1. The nitrogen releasing rate in dry seeding was 83% for sandy loam, 81% in clay loam for 3.5 months after initial releasing, and in infant-seedling was 89% in both soil types for 4 months. 2. The degree of rice leaf color was the highest at the heading stage, and was high with increasing CUC application level regardless of cultural methods, especially was higher at harvesting stage in the 100% level of CUC to standard application amount of fertilizer than conventional fertilizer. 3. The perfect rice grain ratio was higher in infant-seedling than in dry seeding, but lowered with increasing CUC application level regardless of cultural methods. The green kerneled rice ratio among imperfect rice grain was high in dry seeding, and the notched belly rice kernel ratio was high in infant-than infant-seedling of the both soil types, and increased with increasing CUC application level. 4. Hon-value in rice grain was higher at the treatment of CUC application than conventional fertilizer in dry seeding. However, it was contrary result in infant seedling, and was low tendency with decreasing CUC application. On the other hand, the protein in rice grain was also same tendency of Hon-value. Cel-consistency related to eating quality was longer with increasing CUC application level regardless of cultural methods. However, there was no clear tendency at clay loam. 5. No significant difference between rice yield and CUC application in the range of 60% to 100% at both soil types in dry seeding was observed. These results appeared in clay loam under infant seedling except sandy loam. Accordingly, it was thought that 60% level of CUC to standard application amount of fertilizer could be applicated for growth and quality of rice.

• Food Science and Preservation
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• v.16 no.6
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• pp.830-837
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• 2009

A total of 24 processed barley samples produced in Korea, 9 split and 15 pressed, were analyzed for protein, $\beta$-glucan, and amylose content whiteness cooking characteristics (water absorption and expansibility) and pasting properties, with respect to the areas in which they were grown. Split and pressed barley products from Japan were compared. Both forms of barley products had similar contents of protein and $\beta$-glucan. Whiteness was higher in pressed barley than in split barley. Split barley produced in Korea had a higher water absorption (342-436%) and expansibility (449-608%) than did pressed barley. Japanese processed barley products were much lower in protein (4.4-6.6%, w/w) and showed a higher whiteness grade than did Korean products. Whiteness of pressed barley ranged from 57.2-68.3 and was higher than that of split barley, but split barley product showed better cooking characteristics than did pressed barley. Japanese products were similar to Korean materials in this respect. A negative correlation was observed between protein content in and whiteness of processed barley products (r=-0.5112, p<0.01). Waxy barley products had a lower pasting temperature, and showed higher breakdown and lower setback than did non-waxy barley products. The pasting properties of Japanese products were different from those of Korean materials. The pasting temperatures of Japanese split and pressed barley were lower, and the setback much higher, than seen with Korean products. The results show that both splitting and pressing efficiently improve the cooking characteristics of barley. The processing of waxy barley was particularly effective.

• Journal of Korean Society of Forest Science
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• v.83 no.3
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• pp.280-285
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• 1994

This study was conducted to investigate the effects of acid deposition on forest soil, major five Korean forest soils(Brown, Dark red, Gray brown, Red and Yellow, and Volcanic ash forest soils) The samples were subjected to receive 1200mm($100mm{\times}12$ times) of artificial acid rain adjusted to pH5.6, 4.0, 3.0 and 2.0. The results obtained of major importance are summarized as follow ; 1. Ca appeared mostly affected at pH treatment of 2.0, while less affected by other pH treatments. Leaching of Ca rapidly increased with increasing of artificial acid rain acidity and application times in Dark red forest soil. 2. In the cases of Mg, K and Na, they showed gradual increase with the addition of artificial acid rain. Mg and Na losses showed similar leaching patterns, but they didn't show difference among the five forest soils. 3. Exchangeable canon concentrations in the soil leachates, which looked slightly different among the five forest soils, were the highest in pH2.0 treatment. Hydrogen ion comsumption capability by exchangeable canon was the highest in Dark red forest soil followed by Volcanic ash, Red and Yellow, Gray brown and Brown forest soils when artificial acid rain were treated.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.65-65
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• 2018

갈바륨 도금강판은 알루미늄의 우수한 차폐 특성과 내열성, 열 반사성을 가지며 아연의 희생방식 특성을 겸비하여 동일 부착량의 용융 아연도금 및 알루미늄 도금강판에 비해 우수한 내식성을 나타낸다고 알려져 있다. 또한 이것은 표면이 미려하고 경제성이 높아 건자재 용도로 현재까지도 세계적으로 널리 이용되고 있다. 여기서 지칭하는 바륨 도금강판(galvalume steel)은 아연과 알루미늄 도금강판의 장점을 접목하기 위해 55 Al-43.4 Zn-1.6 Si (wt.%)로 구성되어 개발된 3원계 성분의 합금도금강판이다. 한편, 최근에는 강재의 내식성을 향상시키기 위한 다양한 연구 결과에 의해 Zn-Al-Mg의 3원계 합금도금강판도 개발되어 사용되고 있다. 이것은 기존의 아연도금 강판 보다 10배 정도의 우수한 내식성을 나타내는 것으로 보고되고 있다. 특히, 이것은 도금된 평판부의 내식성은 물론 절단된 도금 단면부의 내식성도 매우 우수하다고 알려져 있다. 그러나 상기한 갈바륨 도금강판의 경우에는 도금된 표면부에 비해 단면부의 내식성이 상대적으로 취약한 것으로 알려져 있다. 따라서 본 연구에서는 갈바륨 도금강판의 내식성을 종합적으로 향상시키기 위하여 이 갈바륨 도금강판 상에 PVD 스퍼터링법에 의해 Mg 코팅막의 제작을 시도하였다. 여기서 Mg 코팅막은 후처리 된 갈바륨 도금강판 상에 Ar 공정압력 2 및 20 mTorr 조건 중 1.5 및 $3{\mu}m$ 두께로 제작하였다. 또한 제작한 코팅막에 대해서는 모폴로지 관찰(SEM) 및 결정구조 분석(XRD)을 하였고, 분극측정, 염수분무 시험(SST) 및 복합부식 시험(CCT)에 의해 표면 및 단면부의 내식성평가를 수행하였다. 또한 여기서는 염수분무 및 복합부식 시험 후의 시험편도 채취 하여 표면 및 단면부위에 대한 원소조성 분석(EPMA)과 결정구조 분석(XRD)을 실시하였다. 이상의 실험 결과에 의하면, 본 실험에서 제작한 Mg 코팅막은 그 두께가 두꺼울수록 표면 Mg 결정립의 크기가 증가하였고, 그 부식속도가 증가하는 경향을 나타내었다. 또한 여기서는 공정압력이 높은 조건에서 제작한 막일수록 Mg(002)면 피크 강도가 감소하고 Mg(101)면 피크의 배향성이 증가하였다. 그때 그 막의 내식성은 향상되는 경향을 나타내었다. 그리고 종합적으로 염수분무 및 복합부식 시험 결과에 의하면 Mg이 코팅된 갈바륨 도금강판은 기존 갈바륨 도금강판 보다 내식성이 현저히 향상되었다. 특히, 단면부 내식성의 경우에는 기존 대비 5배 이상 향상되는 경향을 나타내었다. 여기서 단면부 내식특성 분석을 위한 EPMA 원소조성 분석 결과에 의거하면, 부식 초기에는 마그네슘의 부식생성물에 의해 단면부가 치밀하게 보호되고 있음을 확인할 수 있었다. 그 이후에는 부식이 지속적으로 진행됨에 따라 갈바륨 도금층에서 용출된 알루미늄 및 아연 성분이 마그네슘과 함께 치밀한 부식생성물을 형성하여 단면부를 차폐함에 따라 단면부의 내식성이 크게 향상된 것으로 생각된다. 이러한 부식생성물의 결정구조 분석 결과에 따르면, 염수분무와 복합부식 시험에서는 공통적으로 MgO, $Mg(OH)_2$ 이외에도 Simonkolleite상 등이 형성되었다. 또한 건-습 반복 부식시험인 복합부식시험 후에는 $Mg_5(CO_3)_4(OH)_24H_2O$(Hydromagnesite)상 등이 형성됨을 확인할 수 있었다. 즉, 본 실험에서 후처리된 갈바륨 도금강판 상에 제작한 마그네슘 코팅막의 경우에는 상기와 같은 다양한 부식반응에 의해 표면 및 단면부에 형성된 Mg계 부식생성물과 $Zn_5(OH)_8Cl_2H_2O$(Simonkolleite)상에 의해서 표면은 물론 단면부 내식성이 크게 향상된 것으로 사료된다.

• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.528-534
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• 2011

This study was conducted to investigate the changes in saponin content and antioxidant activity of crude ginseng and extruded ginseng by using different solvent extraction methods. Each of the fractions was first extracted by 80% ethanol followed by ether treatment to remove the lipid components. Water soluble components were separated by ethylacetate and water saturated butanol. Four fraction, including 80% ethanol, ethylacetate, butanol and water were obtained from crude and extruded ginsengs to analyze saponin content and antioxidant activity. Saponin content and antioxidant capacity of each of the four fractions were measured by LC/MS analysis and ORAC(Oxygen Radical Absorbance Capacity) assay, respectively. It was found that a major portion of saponin was present in ethyl acetate and water saturated butanol fractions. When extracted by 80% ethanol, ginsenoside Rb1 and Rg1 were mostly found in crude ginseng, while ginsenoside Re and Rb1 were detected in extruded ginseng. Even though Rh1 and Rg3 were found in a very small quantity in crude ginseng, there was a significant quantity of both in extruded ginseng when extracted by 80% ethanol. Similar tendency was also observed in extruded ginseng fraction when extracted with ethyl acetate and butanol. In crude ginseng, the level of Rg1 was the highest among other ginsenosides upon extraction by ethyl acetate, while Rh1 and Rg3 were predominantly found by employing similar solvent extraction in the extruded ginseng. Also, Rg1, Re and Rb1 were also found in the extruded ginseng with small quantity. Rg1, Re and Rb1 were found in crude ginseng by butanol extraction, while Rb1 and Re were extracted from the extruded ginseng. Overall, there was no difference in the saponin content between crude ginseng and extruded ginseng when extracted by butanol and water, but twice as much of saponin was obtained by 80% ethanol extraction and 6 times more saponin were obtained in ethyl acetate fraction in the extruded ginseng. Antioxidant capacity of crude ginseng as determined by ORAC assay was higher in 80% ethanol(high in many different kinds of biological compounds) and water saturated butanol(high in polar saponin) fractions than the ethyl acetate and water fractions. No difference in antioxidant capacity was observed between crude and extruded ginseng. However, antioxidant capacity of ethyl acetate and water fractions in extruded ginseng was significantly higher than crude ginseng($P$ >0.05). All the fractions in both, crude and extruded ginseng possessed antioxidant capacity and even water fractions that contained almost no saponin had some antioxidant capacity. While determining correlation coefficient between fractions in extruded ginseng by Pearson correlation, it was observed that 80% ethanol fraction was in correlation with ethyl acetate($P$ >0.01) and ethanol($P$ >0.001) and in the case of ethylacetate, correlation was observed only with butanol fraction($P$ >0.05).