• 한국임상수의학회지
• /
• 제23권4권
• /
• pp.416-420
• /
• 2006

Compare to testing sera individually, pooled-serum testing has considered as a cost-effective method, particularly on a large population-based seroprevalence studies. This study was to determine the relationship between individual sera and pooled sera titers for detection of avian infectious bronchitis virus (IBV) and to evaluate suitability of pooled sera by comparing prevalences estimated from both samples. A total of 5,000 individual samples were collected from 500 flocks in Chungcheong, Gyunsgi, and Kangwon provinces between January 2005 and February 2006. Ten samples were randomly selected from each flock. Five-hundred pooled sera were prepared by mixing equal amount of each 10 individual serum from the original samples. IBV antibody titers were measured by hemagglutination inhibition (HI) test. The least squares regression analysis was performed to construct equation between pooled and mean individual titers. To determine whether the flock is infected 4 arbitrary criteria were used: detection of at least 1 chicken with HI titer ${\ge}$ 9 (criterion 1), detection of at least 2 samples with HI titer ${\ge}$9 (criterion 2), detection of at least 1 sample with HI titer ${\ge}$ 10 (criterion 3), and filially detection of at least 1 sample with HI titer ${\ge}$ 11 (criterion 4). The receiver operating characteristic (ROC) curve was used to examine the cut-off points of pooled titers showing optimal diagnostic accuracy. The area under the curve (AUC), sensitivities (Se), specificities (Sp), and positive (PPV) and negative (NPV) predictive values were calculated. The regression equation between pooled titers (pool) and mean individual titers (mean) was: $pool= 1.2498+0.8952{\times}mean$, with coefficient of determination of 87% (p< 0.0001). The optimal cut-off points of pooled titers were titer 8 for criterion 1 (AUC=0.975, Se=0.883, Sp=0.959, PPV=0.985, NPV=0.728), titer 8 for criterion 2 (AUC=0.969, Se=0.954, Sp=0.855, PPV=0.926, NPV=0.907), titer 9 for criterion 3 (AUC=0.970, Se=0.836, Sp=0.967, PPV=0.978, NPV=0.772), and titer 9 for criterion 4 (AUC= 0.946, Se=0.928, Sp=0.843, PPV=0.857, NPV=0.921). The difference of 'prevalence estimated by individual and pooled sample showed a minimum of 2% for criteria 2 and a maximum of 9.1:% for criteria 3. These results indicate that the use of pooled sera in HI test for screening IBV infection in laying hen flocks is considered as a cost-effective method of testing large numbers of samples with high diagnostic accuracy.

• 한국결정성장학회지
• /
• 제24권6호
• /
• pp.268-273
• /
• 2014

$Y_2O_3$ 세라믹 소결체를 제작하기 위해, $Y_2O_3$ 분말을 분산한 상태에서 슬러리에 pH 조절제인 NaOH를 첨가하였으며 결합제로는 PVA, 가소제로는 PEG를 첨가하여 열분무 건조 공정을 거쳐 $Y_2O_3$ 과립형 분말을 제조하였다. ${\phi}14mm$ 크기의 $Y_2O_3$ 세라믹 성형체를 성형하고, $1650^{\circ}C$의 온도에서 소결하여 $Y_2O_3$ 세라믹 소결체를 제작하였다. $Y_2O_3$ 소결체의 미세구조, 밀도 및 내플라즈마 특성이 성형압력 및 소결시간에 따라 분석되었다. $Y_2O_3$ 소결체는 $CHF_3/O_2/Ar$ 플라즈마에 노출시켜, $Ar^+$ 이온빔에 의한 물리적반응 식각과 $CHF_3$로부터 분해된, $F^-$ 이온에 의한 화학적반응 식각에 의한 건식 식각 처리가 이루어졌다. 본 연구에서 $Y_2O_3$ 소결체 소결시간의 증가에 따라, 비교적 높은 밀도를 나타내었으며, 내플라즈마 특성이 향상되는 것으로 나타났다.

• 한국식품영양과학회지
• /
• 제46권1호
• /
• pp.140-145
• /
• 2017

본 연구에서는 식품으로 활용하기 위해 제조된 잣송이 추출물의 이화학적 품질 특성과 항산화 활성을 탐색하였다. 잣송이 추출물은 수분과 탄수화물이 구성성분 대부분을 차지하고 있었으며, 특히 대조군으로 사용된 매실 추출물보다 수분함량은 낮고 당 함량은 높아 유의적으로 높은 점도를 나타내었다. 또한, 갈색도와 색도는 모두 낮아 매실 추출물과 비교해 숙성 중 Maillard 갈변 반응의 정도가 상대적으로 낮았음을 시사해주었다. 잣송이 추출물은 매실 추출물보다 플라보노이드 함량은 유의적으로 다르지 않았으나 유기산 함량과 갈변도는 1/10 수준으로 유의적으로 낮았고, 총환원력은 매실 추출물의 60% 수준으로 측정되었다. 그런데도 잣송이 추출물에서 매실 추출물과 유사한 높은 금속 소거능과 라디칼 소거 활성이 관찰되었다. 또한, 잣송이 추출물 속 플라보노이드 총량보다도 많은 양인 6.6 mM quercetin과 비교할 때 2배나 높은 SOD 유사 활성을 나타내었다. 이는 잣송이 추출물에 quercetin보다 항산화 활성이 높은 플라보노이드가 존재할 가능성을 보여주며, 플라보노이드 조성에 대한 후속연구의 필요성을 시사해주었다. 본 연구는 잣송이 추출물이 제조법과 용도가 유사한 매실 추출물에 버금가는 항산화 활성을 부여하면서도 상대적으로 높은 당 함량과 낮은 유기산 함량으로 매실 추출물과는 관능적 측면에서 차별화될 수 있는 식품으로서의 활용 가능성을 보여주었다.

• 한국양식학회지
• /
• 제16권2호
• /
• pp.104-109
• /
• 2003

The present study aims to evaluate protein and phosphorus availabilities of five different dietary protein sources during the 6-week feeding trial in juvenile olive flounder, Paralichthys olivaceus as determined by growth performance and phosphorus retention. Five diets containing blood meal (BM), poultry by-product (PBP), squid liver powder (SLP), feather meal (FM) and soybean meal (SM) were prepared by mixing a basal diet (BD) with one of five test ingredients at the ratio of 7 to 3. As a reference diet, BD contains three different protein sources such as white fish meal, casein and gelatin. After 2 weeks of the conditioning period, fish initially averaging 2.7$\pm$0.02g (mean$\pm$SD) were randomly distributed into each aquarium as a group of 30 fish reared in the recirculating system. Fish of triplicate groups were fed one of six experimental diets (BD+five test diet). After 6-week feeding trial, pro- tein efficency ratio (PER) of fish fed BM diet was the lowest in experiment groups. While fish fed PBP diet showed a significant higher PER as compared to the FM diet, and fish fed SLP diet and BD were a higher PER than did fish fed PBP diet. However, there was no significant difference in PER among fish fed SLP diet, BD and SM diet, and between SM diet and PBP diet. Phosphorus retention efficiency of bone (PR $E_{b}$) of fish fed BM diet was the lowest in all the diets, and fish fed FM diet showed a higher PE $R_{b}$ than fish fed BD and SM diet. However, there was no significant difference in PER among fish fed FM diet, SLP diet and PBP diet, and among SLP diet, PBP diet, SM diet and BD. These results indicate that SLP could be a suitable protein source for low pollution diets of olive flounder in the future fish feeds market. Furthermore, PBP and SM are available protein source to reduce P waste in the oliver flounder aquaculture with the use of proper mixture of other protein sources and more processing to improve protein availibility of these.ese.

• Asian-Australasian Journal of Animal Sciences
• /
• 제15권11호
• /
• pp.1599-1605
• /
• 2002

In this study, three different experiments were conducted to evaluate the nutritional value of apple pomace produced in southern areas of the Republic of Korea (South Korea). The effects of combining apple pomace in different ratios with commercial concentrates and rice straw in the diets of Korean native goats (Capra hircus) were examined. In experiment I, in situ DM and CP disappearances from nylon bags incubated in the rumen of goats showed that greater amounts of DM and CP were released from apple pomace than those from concentrates at the later stages of incubation, but only after 48 h for DM and CP, respectively. This was reflected in the higher 'b' value of the slowly degradable fraction of the apple pomace compared to the concentrates. Prior to these times the trend was reversed. In experiment II, Korean native goats were fed a diet containing apple pomace with either rice straw or rice straw and concentrates, and the in vivo nutrient digestibilities compared to animals receiving an alfalfa hay. DM digestibility in the animals given apple pomace plus concentrates with rice straw (66.86%) were similar to the goats given alfalfa hay only (69.09%) but significantly greater than for a diet of rice straw plus concentrates. In experiment III, an in vivo study was conducted to investigate the inclusion of 30 to 60% apple pomace pre-mixed with rice straw, rice bran and concentrates on the nutritional value for Korean native goats. Apple pomace mixed diets had higher DM intakes, nutrient digestibility and nitrogen retention than diets without apple pomace, which may have been due to the higher non-structural carbohydrates (NSC) and less ADF and NDF than those in other treatments. Replacement of concentrates with apple pomace in rice straw based diets of Korean native goats fed either separately (experiment II) or by pre-mixing (experiment III) gave satisfactory feed intake, digestibility, pH of ruminal fluid and production of $NH_3$-N and VFA in the rumen of goats. The results of this study infer that apple pomace can be included at levels of up to 60% in the diets of goats without dramatic effect on the animal.

• 한국식품저장유통학회지
• /
• 제8권3호
• /
• pp.308-312
• /
• 2001

진품콩에 작두콩의 종실을 첨가하여 맛과 영양이 우수한 요구르트를 제조하기 위하여 진품콩에 작두콩의 혼합 비율별로 두유를 착즙하고 유산발효 시킨 제품의 가공특성을 검토하였다. 원료콩의 단백질 함량은 진품콩이 38.0%로 작두콩 27.5f%보다 높았다. 유산발효 중 PH와 당도는 발효개시 후 4시간까지는 급격히 저하했다가 8시간 이후에는 완만하게 감소하였으며 유기산 함량과 유산균 수는 증가하였고, 20시간 발효시 진품콩 100%에 비하여 진품콩 95%와 작두콩 5% 혼합 요구르트 특성은 유사한 경향을 보였다. 진품콩 95%와 작두콩 5% 혼합 요구르트의 발효중 생균수는 20시간까지 증가하였으나 이후에는 현저히 감소하여 진품콩 100%와 유사한 경향이었다. 20시간 발효후 요구르트의 색도는 진품콩 95%와 작두콩 5% 혼합 처리구가 진품콩 100%와 유사한 값을 보였으나, 진품콩 90%와 작두중 10% 혼합 요구르트는 발효전과 후의 색도 변화가 거의 없었다. 관능검사 결과 진품콩 95%와 작두중 5% 혼합 요구르트에 사과시럽보다 딸기시럽을 첨가한 것이 기호도가 더 높았다.

• 한국식품조리과학회지
• /
• 제30권4호
• /
• pp.463-471
• /
• 2014

Yetgangjeong is a traditional Korean rice cookie which used rice syrup (Chocheong) to bind fried rice grains. Brown waxy rice and binders prepared using different sugar types and end heating temperatures were assessed to improve the textural properties and functionality and to promote global consumption. Binder was made by mixing different ratios of starch syrup, rice syrup, honey, sugar, and trehalose, and the binder mixture was heated up to a temperature of $100^{\circ}C$ or $105^{\circ}C$. Specific electrical conductivity of binder containing ST (starch syrup and trehalose) showed the lowest values (9.51 and 9.77), and binders containing the rice syrup showed increased values for specific electrical conductivity. The fructose content was higher in the binder mixture containing C (starch syrup and sugar) than in the binder mixture containing ST, but it did not affect the end temperature. Viscosity of the binder was 123.90-175.20 cP and the binder showed higher viscosity at the end heating temperature (EHT) of $100^{\circ}C$ compared at EHT of $105^{\circ}C$. The fracturability of brown rice yetgangjeong prepared using different sugar types was higher at EHT of $100^{\circ}C$ than at that of $105^{\circ}C$ and it was reduced with an increase in the rice syrup content. However, the hardness of yetgangjeong was lower at $100^{\circ}C$, unlike fracturability. With respect to sensory evaluation, its moistness and stickiness decreased, but the crunchiness increased with addition of trehalose instead of sucrose. The overall eating quality score of yetgangjeong was higher at EHT of $105^{\circ}C$ than at that of $100^{\circ}C$ in every experiment and the highest score was found for SHT (starch syrup, honey and trehalose) with 20% rice syrup at EHT of $105^{\circ}C$ (20%RSHT105 (starch syrup, honey, and trehalose containing 20% rice syrup)).

• Ocean and Polar Research
• /
• 제29권2호
• /
• pp.135-153
• /
• 2007

Temporal (seasonal) and spatial distributions and variations of various physico-chemical factors (salinity, temperature, pH, DO, COD, SPM, POC, silicate, DIP, DIN) in surface and bottom waters were studied in the coastal environment with typical macro-tidal range and monsoonal weather condition, Gyeonggi Bay, west coast of Korea. Spacial distribution patterns of these factors were generally similar to each other, and appeared to be inversely related to the distribution pattern of salinity, suggesting that water quality of the study area was primarily controlled by the physical mixing process of Han-River freshwater with nearby coastal seawater. During flooding season, silicate- and nitrogen-rich Han River water directly flowed into offshore as far as $20\sim30\;km$ from the river mouth, probably causing serious environmental problems such as eutrophication and unusual and/or noxious algal bloom, etc. Except the surface water during summer flooding season, high concentrations of nutrients appeared generally in dry season, whereas low values in spring, possibly because of the occurrence of spring phytoplankton bloom. On the other hand, nutrient flux through the estuary seems to be primarily depending on river discharge, sewage discharge and agricultural activities, especially during the rainy season. Also, nutrients in this coastal waters are considered to be supplied from the sediments of tidal-flats, which developed extensively around the Han-River mouth, especially during fall and winter of dry and low discharge seasons, possibly due to the stirring of tidal flat sediments with highly enriched pore-water nutrients by storm. And also, COD and DIN concentrations in the study area consistently increased during the last 20 years, probably because of agricultural activities and increasing discharge of industrial and domestic wastes.

• 자원리싸이클링
• /
• 제14권4호
• /
• pp.22-33
• /
• 2005

폐타이어 분말(GRT)을 재활용하기 위하여 sheet type 4그룹과 soft type 1그룹의 자체보수성 방수재를 제조하였다. 각각 방수재의 방수특성을 고찰하기 위하여 방수재들의 물성을 측정하였다. 방수재는 GRT/ 고흡수성수지/ binder로 구성되었으며, internal mixer로 혼합한 후 hot press로 성형하여 제조 되었다. 방수재 제조에 사용된 CRT의 평균입도는 -40mesh 이었고, 고흡수성 수지는 상용품과 poly(AM-SAS-AA)를 제조하여 사용하였고, binder는 PU, EVA, LDPE, SBR, poly(2-EHA)을 사용하였다. 또한 방수재의 물성을 향상시키기 위하여 보강재로 PU film을 사용하였다. 폐타이어 분말을 이용하여 개발된 sheet type 자체보수성 방수재 중 GRT/ CE-500F/EV-600/PU film 과 GRT/GE-500F/SBR(vulcanization)/PU film 로 구성된 방수재가 기존 상용제품의 물성에 근접하였다. 또한 soft type 방수재는 GRT/GE-500F/Poly(2-EHA)와 GRT/P(AM-SAS-AA)/Poly(2-EHA)로 구성된 방수재가 상용제품의 흡수능보다 4-20배의 개선된 결과를 나타내었다.

• 자원환경지질
• /
• 제29권4호
• /
• pp.411-419
• /
• 1996

The Janggun magnetite deposits occur as the lens-shaped magnesian skarn, magnetite and base-metal sulfide orebodies developed in the Cambrian Janggun Limestone Formation. The K-Ar age of alteration sericite indicates that the mineralization took place during late Cretaceous age (107 to 70 Ma). The ore deposition is divided into two stages as a early skarn and late hydrothermal stage. Mineralogy of skara stage (107 Ma) consists of iron oxide, base-metal sulfides, Mg-Fe carbonates and some Mg- and Ca-skarn minerals, and those of the hydrothermal stage (70 Ma) is deposited base-metal sulfides, some Sb- and Sn-sulfosalts, and native bismuth. Based on mineral assemblages, chemical compositions and thermodynamic considerations, the formation temperature, $-logfs_2$, $-logfo_2$ and pH of ore fluids progressively decreased and/or increased with time from skarn stage (433 to $345^{\circ}C$, 8.8 to 9.9 atm, 29.4 to 31.6 atm, and 6.1 to 7.2) to hydrothermal stage (245 to $315^{\circ}C$, 11.2 to 12.3 atm, 33.6 to 35.4 atm, and 7.3 to 7.8). The ${\delta}^{34}S$ values of sulfides have a wide range between 3.2 to 11.6‰. The calculated ${\delta}^{34}S_{H_2S}$ values of ore fluids are relatively homo-geneous as 2.9 to 5.4‰ (skam stage) and 8.7 to 13.5‰ (hydrothermal stage), which are a deep-seated igneous source of sulfur indicates progressive increasing due to the mixing of oxidized sedimentary sulfur with increasing paragenetic time. The ${\delta}^{13}C$ values of carbonates in ores range from -4.6 to -2.5‰. Oxygen and hydrogen isotope data revealed that the ${\delta}^{38}O_{H_2O}$ and ${\delta}D$ values of ore fluids decreased gradually with time from 14.7 to 1.8‰ and -85 to -73‰ (skarn stage), and from 11.1 to -0.2‰ and -87 to -80‰ (hydrothermal stage), respectively. This indicates that magmatic water was dominant during the early skarn mineralization but was progressively replaced by meteoric water during the later hydrothermal replacement.