• 한국물환경학회지
• /
• 제22권5호
• /
• pp.933-942
• /
• 2006

In this study, temperature, turbidity, suspended paniculate matter (SPM) distribution and mineral characteristics were investigated to explain spatial distribution of the turbid-water environment of Yongdam reservoir in July, 2005. Six stations were selected along a longitudinal axis of the reservoir and sampling was conducted in four depths of each station. Water temperature was showed the typical stratified structure by the effects of irradiance and inflow. Content of inorganic matter in suspended particles increased with the concentration of suspended particulate matter (SPM) due to the reduction of ash-free dry matter (AFDM). Turbidity ranged from 0.6 to 95.1 NTU and the maximum turbidity value of each station sharply increased toward downstream from upstream. The high turbidity layers were located at the depth between 12~16 m. Particle size ranged from 0.435 to $482.9{\mu}m$. day and silt-sized particles corresponded 91.9~98.9% and 1.1~8.0% in total numbers of SPM, respectively. Turbidity showed high correlations with clay (r=0.763, p<0.05) and silt content (r=0.870, p<0.05).Inorganic matter content (r=0.960, p<0.01) was more correlated with turbidity than organic matter (r=0.823, p<0.05). Mineral characterization using x-ray diffraction and electron probe microanalyzer demonstrated that the major minerals contained in the SPM were kaolinite, illite, vermiculite and smectite. As results of this study, surface water discharge as well as small size of the SPM were suggested as long-term interfering factors in settling down the turbid water in the reservoir.

• 한국환경생태학회지
• /
• 제29권1호
• /
• pp.1-6
• /
• 2015

In this study, the proximate composition of Pyropia dentata was compared by the analysis of minerals and amino acids that were produced at Seocheon, Chungcheongnam-do and at Wando and Jangheung, Jeollanam-do. Moisture, ash and crude proteins were analyzed using the AOAC method, and crude lipid was analyzed using the Soxhlet method, and inorganic analysis was performed using ICP-OES. Amino acid was used for the amino acid analyzer. The proximate composition analysis, moisture content, maximum values were displayed in Wando while the maximum content of ash appeared at Jangheung's Pyropia. Crude proteins was appeared at Seocheon's Pyropia and the maximum amount of crude lipid, carbohydrate was appeared in Wando's Pyropia. Inorganic analysis, calcium, potassium, magnesium, sodium, phosphorus, cobalt, chromium, copper, iron, manganese, nickel, zinc were analyzed from the Seocheon's Pyropia, however, cobalt, chromium, and nickel was not detected in Wando's Pyropia. For amino acid analysis, a total of 17 amino acids were detected: leucine, valine, aspartic acid, glutamic acid, and the amount of alanine accounted for about 57 % of total amino acids(26.1-28.7 %). The proximate composition, minerals, and amino acid of Pyropia dentata were different depending on the coastal ecological habitats.

• 한국토양비료학회지
• /
• 제49권5호
• /
• pp.510-516
• /
• 2016

Soil respiration has been recognized as a key factor of the change of organic matter and fertility due to the carbon and nitrogen mineralization. In this study, we evaluated the effect of soil respiration on the light fraction-C and inorganic N content depending on temperature in soil applied with organic matter. Soil respiration was calculated by using total $CO_2$ flux released from soil applied with $2Mg\;ha^{-1}$ of rice straw compost and rye for 8 weeks incubation at 15, 25, $35^{\circ}C$ under incubation test. After incubation test, light fraction and inorganic N content were investigated. Rye application dramatically increased soil respiration with increasing temperature. $Q_{10}$ value of rye application was 1.69, which was higher 27% than that of rice straw compost application. Light-C and $NO_3-N$ contents were negatively correlated to soil respiration. Light-C in rye application more decreased than that in rice straw compost with temperature levels. These results indicate that temperature sensitivity of soil respiration could affect soil organic mater content and N availability in soil due to carbon availability. Also, light fraction would be useful indicator to evaluate decomposition rate of organic matter in soil under a short-term test.

• 한국농공학회:학술대회논문집
• /
• 한국농공학회 2005년도 학술발표논문집
• /
• pp.128-134
• /
• 2005

This study was performed to evaluate the strength and durability properties of recycled concrete containing water - redispersible copolymer powder(WRP) and blast furnace slag powder(BSP) [RCWS]. Material used were cemente, recycled coarse aggregare, natural fine aggregate, water-redispersible copolymer powder, blast-furnace slag powder. Especially, Water-redispersible powder was used for blending with Inorganic binders such as cemente, gypsum and hydrated lime etc. First of all, Mixed ratio method of RCWS made Two Type. One was called type-1 which used to BSP content 5% and WRP(Water-redispersible powder) content 0%, 1%, 2%, 3%, 4%, 5%, 6%. respectively. Another was called Type-2 which used to BSP(blast furnace slag powder)content 10% and WRP(Water-redispersible powder) content 0%, 1%, 2%, 3%, 4%, 5%, 6%. respectively. According to the experimental results of (RCWS), Incase Type-2 at curing age 28days, Compressive strength, pulse velocity and dynamic modulous of elasticity were shown higher than Type-1 and The more WRP content increasing($0%{\sim}6%$) was the lower Compressive strength, Pulse velocity and Dynamic modulous of elasticity. Water absorption ratio was in the range of $3.85%\;{\sim}\;3.23%$, it was almost equal to Type-1, 2 but Increasing the WRP content($0%{\sim}6%$), The water absorption ratio is decreased.

• 식품보건융합연구
• /
• 제9권2호
• /
• pp.19-24
• /
• 2023

In this study, we tried to compare and analyze the taste components of Korean Ganjang made by a conventional method on a small scale and aged for 3 years and brewed Ganjang produced by a large company. As a result of the study, a total of 22 types of free amino acids in liver were detected. The main amino acids of Korean Ganjang were glutamic acid, lysine, serine, citrulline, alanine, and leucine, then, the main amino acids of brewed Ganjang were leucine, glutamic acid, aspartic acid, valine, serine, alanine. The content of glutamic acid in the composition of free amino acid was 12133.69 mg/mL, more than twice as much as that of Korean Ganjang. The content of leucine (bitter taste) was 5933.37 mg/mL of brewed Ganjang, which was 2.9 to 7 times higher than that of Korean Ganjang. Overall, the content of glass amino acids with savory, sweet, and bitter flavors was found to be very high in brewed Ganjang (BGS) than in Korean Ganjang (KAS, KBS, and KCS). On the other hand, GABA was 456.43 mg/mL for Korean Ganjang KBS, 3.3 times higher than brewed Ganjang. Brewed Ganjang had higher glucose content, inorganic content, iron (Fe), organic acid lactic acid and acetic acid content than Korean Ganjang. Korean Ganjang was found to contain high saturated fatty acids, calcium (Ca), and sodium (Na).

• The Korean Journal of Ceramics
• /
• 제7권1호
• /
• pp.26-29
• /
• 2001

Indium tin oxide (ITO) films were deposited on glass substrates at $300^{\circ}C$ in oxygen/argon mixtures by RF-enhanced DC-magnetron sputtering and were compared to those by conventional DC magnetron sputtering. The RF enhancement was performed using a coil above an ITO target. X-ray diffraction measurements revealed that RF-enhanced plasma affected the preferred orientation and the crystallinity of the films. The resistivity of the films prepared by RF-enhanced DC-magnetron sputtering was almost constant at oxygen content lower than 0.3% and then increased sharply with increasing oxygen content. However the resistivity of the films by conventional sputtering has little dependence on the oxygen content. Those results can be explained on the basis of the incorporation of oxygen into the ITO films due to the RF enhancement.

• 한국염색가공학회지
• /
• 제12권5호
• /
• pp.295-300
• /
• 2000

The melting behavior of hydrated polyacrylonitrile (PAN) and the rheological properties of hydrated PAN melt were investigated using DSC md modified capillary rheometer. With increasing the water content, Tm of the hydrated PAN was rapidly decreased and finally levelled off above a critical water content. However, the melt viscosity was further decreased even above the critical water content. The hydrated PAN melt showed a typical shear thinning behavior. In arrhenius plot, when the hydrated PAN melt was supercooled, it exhibited a different dependency on temperature from that above melting temperature.

• 한국환경과학회지
• /
• 제20권5호
• /
• pp.565-574
• /
• 2011

This study analyzed the concentration of the heavy metals(Cd, Hg, iAs) of urine(n=576) from May, 2007 to Oct 2007. The subject was residents in G, Y, H industrial area, Jeollanam-do, in which exposure due to the adjacency of the industrial complex. As to the heavy metal concentration in the urine of the residents in the whole exposed region and the comparing region, the content of cadmium, mercury, and inorganic arsenic in the exposed region group were 1.23, 1.85, and 8.80 ${\mu}g$/g_ct respectively, and those of the comparing region group were 1.87, 2.00, and 8.93 ${\mu}g$/g_ct respectively, which indicates that the concentration of the comparing group was higher than that of the exposed group. The heavy metal concentration for each age group increased in proportion to age except those under 10 for some substances(p<0.01). As to geometric mean concentration cadmium and inorganic arsenic in urine according to the smoking history of the subject, the concentration of the smoking group and the non-smoking group were 1.65 ${\mu}g$/g_ct and 9.13 ${\mu}g$/g_ct respectively, while those of the non-smoking group were 1.47 ${\mu}g$/g_ct and 8.91 ${\mu}g$/g_ct respectively, which indicates that the former is higher than the latter. As to the inorganic arsenic concentration in urine according to the food preference, in order of vegetable, fish, and meat showed high concentration (p<0.01). To clarify the factors affecting the heavy metal concentration in urine among the subjects, the multiple regression analysis was conducted. As a result, it turned out that as to cadmium content in urine, gender, age, drinking, and smoking have influence on the subjects, with explanatory adequacy of 37.5 %.

• 한국세라믹학회지
• /
• 제39권2호
• /
• pp.184-189
• /
• 2002

본 연구는, PbO-base 유리계의 정보와의 비교 등을 통해 Bi-base 조성 PDP rib으로의 새로운 유리조성 설계를 위한 기초연구의 일환이다. PbO와 유사한 밀도값 및 작업 용이성을 갖고 있는 Bi를 도입한 $Bi_2O_3-B_2O_3-ZnO$ 조성계에 대해, 연화점, 열팽창계수, 에칭성, 유전율 등의 특성측정 및 XPS로 조성에 따른 구조변화 등을 조사하였다. $Bi_2O_3$를 50∼80 wt%까지 폭넓게 첨가된 $Bi_2O_3-B_2O_3-ZnO$계 유리들은 조성에 따라 연화점이 400∼480$^{\circ}C$, 열팽창계수가 $68{\sim}72{\times}10^{-7}/^{\circ}C$, 유전상수는 13∼25으로서 동조성의 Pb-base 조성계와 유사한 물성치를 나타내었다. 특히, Bi의 함유량이 70∼65 wt%의 조성의 경우, 성분 및 물성의 미세조정 등을 통해 rib 재료의 출발조성으로서 적용가능성이 확인되었다. $Bi_2O_3$의 양이 감소함에 따라 $O_{1s}$ peak에서의 결합에너지의 증가와 반가폭(FWHM)이 감소하였는데, 이는 비가교산소의 증가에 기인하였다.

• Journal of Applied Biological Chemistry
• /
• 제57권2호
• /
• pp.171-174
• /
• 2014

$\small{L}$-아르기닌의 알칼리성과 보습성을 식품에 활용하는 연구의 일환으로 폴리인산염 대신에 $\small{L}$-아르기닌을 0.25, 0.5, 1.0% (w/w) 첨가하여 소시지를 제조하고, 각각의 pH, 보수력, 유화 안정성 및 조직감을 조사하였다. 소시지의 pH는 $\small{L}$-아르기닌의 첨가량에 비례하여 증가하였으며, 수분함량은 $\small{L}$-아르기닌을 0.25% 이상, 유화 안정성은 0.5% 이상, 경도와 전단력은 1.0%를 첨가한 결과가 폴리인산나트륨을 0.5% 첨가한 소시지의 특성과 유사하였다. 인산염 0.5%와 $\small{L}$-아르기닌 0.5% 첨가 소시지에 대하여 관능 평가를 실시하였다. 조직감은 인산염을 사용한 시료가 $\small{L}$-아르기닌을 첨가한 시료보다, 맛과 전체적인 기호도에서도 $\small{L}$-아르기닌을 첨가한 소시지가 다소 우수한 것으로 평가되었다. 이상의 결과로부터 소시지 제조시 $\small{L}$-아르기닌은 인산염 대체 소재로 활용될 수 있으며 첨가량은 0.5%가 적절함을 확인할 수 있었다.