• Title/Summary/Keyword: 3G/4G

Search Result 28,329, Processing Time 0.059 seconds

A Study on Equilibrium of $NH_4NO_{3(s)} -HNO_{3(g)} -NH_{3(g)}$ in Urban Atmosphere (도시 대기중에서 $NH_4NO_{3(s)} -HNO_{3(g)} -NH_{3(g)}$의 평형에 관한 연구)

  • 천만영;강병욱;김희강
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.8 no.3
    • /
    • pp.198-203
    • /
    • 1992
  • Theoretical predictions of the atmospheric equilibrium involving $HNO_3, NH_3 and NH_4NO_3$ were compared with atmospheric measurements of particulate nitrate$(NO_3^-)$, $HNO_3$ and $NH_3$ concentration by triple filter pack sampler and Andersen air sampler in Seoul from 8th to 11th Oct 1991. The measured $HNO_3-NH_3$ concentration product K was higher than equilibrium costant Kc calculated from thermodynamic data of $HN_4NO_{3(s)} -HNO_{3(g)} -NH_{3(g)}$. The cause of K is greater than Kc was the result of air pollution, partcicularly anthropogenic $NH_3$.

  • PDF

Management of Critical Control Points to Improve Microbiological Quality of Potentially Hazardous Foods Prepared by Restaurant Operations (외식업체에서 제공하는 잠재적 위험 식품의 미생물적 품질향상을 위한 중점관리점 관리방안)

  • Chun, Hae-Yeon;Choi, Jung-Hwa;Kwak, Tong-Kyung
    • Korean journal of food and cookery science
    • /
    • v.30 no.6
    • /
    • pp.774-784
    • /
    • 2014
  • The purpose of this study was to present management guidelines for critical control points by analyzing microbiological hazardous elements through screening Potentially Hazardous Foods (PHF) menus in an effort improve the microbiological quality of foods prepared by restaurant operations. Steamed spinach with seasoning left at room temperature presents a range of risk temperatures which microorganisms could flourish, and it exceeded all microbiological safety limits in our study. On the other hand, steamed spinach with seasoning stored in a refrigerator had Aerobic Plate Counts of $2.86{\pm}0.5{\log}\;CFU/g$ and all other microbiological tests showed that their levels were below the limit. The standard plate counts of raw materials of lettuce and tomato were $4.66{\pm}0.4{\log}\;CFU/g$ and $3.08{\pm}0.4{\log}\;CFU/g$, respectively. Upon washing, the standard plate counts were $3.12{\pm}0.6{\log}\;CFU/g$ and $2.10{\pm}0.3{\log}\;CFU/g$, respectively, but upon washing after chlorination, those were $2.23{\pm}0.3{\log}\;CFU/g$ and $0.72{\pm}0.7{\log}\;CFU/g$, respectively. The standard plate counts of baby greens, radicchio and leek were $6.02{\pm}0.5{\log}\;CFU/g$, $5.76{\pm}0.1{\log}\;CFU/g$ and $6.83{\pm}0.5{\log}\;CFU/g$, respectively. After 5 minutes of chlorination, the standard plate counts were $4.10{\pm}0.6{\log}\;CFU/g$, $5.14{\pm}0.1{\log}\;CFU/g$ and $5.30{\pm}0.3{\log}\;CFU/g$, respectively. After 10 minutes of chlorination treatment, the standard plate counts were $2.58{\pm}0.3{\log}\;CFU/g$, $4.27{\pm}0.6{\log}\;CFU/g$, and $4.18{\pm}0.5{\log}\;CFU/g$, respectively. The microbial levels decreased as the time of chlorination increased. This study showed that the microbiological quality of foods was improved with the proper practices of time-temperature control, sanitization control, seasoning control, and personal and surface sanitization control. It also presents management guidelines for the control of potentially hazardous foods at the critical control points in the process of restaurant operations.

A Study on the Air Pollution Component in Hwasoon Nulitjae Tunnel (화순너릿재 터널내의 대기오염성분에 관한 조사연구)

  • 신대윤;송금섭;김정규;송연호;임만택
    • Journal of Environmental Health Sciences
    • /
    • v.19 no.3
    • /
    • pp.52-57
    • /
    • 1993
  • This study was carried out to investigate the air pollution in Hwasoon Nulitjae tunnel for two months, from August 1992 to September 1992. The total suspended particles were collected by high volume air sampler at inside and outside of Hwasoon Nulitjae tunnel, of which major water soluble component and heavy metalic element were analyzed. Size distribution and respirable mass fraction of aerosol at inside were measured by filters on nine stages Andersen air sampler. The average concentration of TSP at inside was 657.57 $\mu$g/m$^3$, which appeared about 9.2 times as high as that of 71.47 $\mu$g/m$^3$ at outside. The decrease effect caused by using new tunnel was 31.2%. As a result of correlation analysis between concentration of TSP at inside of Hwasoon Nulitjae tunnel and that at outside, correlation coefficient was 0.713. The average concentrations of SO$_4^{2-}$ , NO$_3^-$, CI$^-$ were 43.02 $\mu$g/m$^3$, 19.86 $\mu$g/m$^3$, 4.96 $\mu$g/m$^3$, those of NH$_4^+$, Na$^+$, K$^+$ 1.42 $\mu$g/m$^3$, 4.45 $\mu$g/m$^3$, 2.89 $\mu$g/m$^3$ and those of Ca$^{2+}$, Mg$^{2+}$, Pb$^{2+}$ 3.92 $\mu$g/m$^3$, 2.27 $\mu$g/m$^3$. 1.52 $\mu$g/m$^3$, respectively. It was estimated that mass fraction rate of respirable particle at inside was about 84.54% of aerosol. The average concentration of suspended particle to be collected by Andersen sampler was 478.90 $\mu$g/m$^3$, this was about 72.8% of that by high volume air sampler.

  • PDF

Misgurnus Anguillicaudatus Growing in Winter Season by Solar Thermal Heating (태양에너지를 이용한 겨울철 미꾸라지 성장에 관한 연구)

  • Jung, Hyun-Chai;Sun, Kyung-Ho;Jo, Jae-Sun;Nam, Sang-Yul
    • Solar Energy
    • /
    • v.11 no.3
    • /
    • pp.31-36
    • /
    • 1991
  • We have maintained the optimum water temperature for misgumus in winter season by solar thermal heating energy. The optimum temperatures for the misgumus anguillicaudatus were experimentally estimated, i.e. for the total length $4{\sim}5cm$ and body weight $1{\sim}2g$, the optimum temperature was $18{\sim}20^{\circ}C$. For the total length $5{\sim}7cm$, body weight $2{\sim}3g$ was $20{\sim}22^{\circ}C$ and for the total length $7{\sim}9cm$, body weight $4{\sim}6g$ was $22{\sim}24^{\circ}C$. The smaller misgumas($1{\sim}3g$) grows relatively slow but the bigger one($4{\sim}8g$) grows relatively fast and total average body weight increment was about $30{\sim}50g$ per month.

  • PDF

Genotype of Group A Rotavirus Isolated in Acute Gastroenteritis Patients and Groundwater in Seoul, Korea (서울지역 급성위장관염 환자 및 지하수에서 분리한 A형 로타바이러스의 유전자형)

  • Kim, Eun-Jeung;Kim, Moo-Sang;Chae, Young-Zoo;Cheon, Doo-Sung
    • Korean Journal of Microbiology
    • /
    • v.47 no.4
    • /
    • pp.323-327
    • /
    • 2011
  • Fecal specimens from acute gastroenteritis in Seoul from 2009 to 2010 were collected and then tested for the presence of Group A Rotavirus by ELISA. Among a total of 1,916 samples investigated, 354 samples (18.4%) were positive. The predominant genotypes of positive samples were confirmed as P6G[4] (35%), P8G[3] (28%), P8G[1] (24%), P4G[2] (10%), P8G[9] (3%), respectively. Among a total of 70 ground water samples investigated, 2 samples (2.8%) were positive. The genotypes of positive samples were confirmed as P8G[3] (100%). By this molecular investigation, genotypic distribution associated with rotavirus will be used for control and prevention of rotavirus related diseases.

Study of Trans Fatty Acids and Saturated Fatty Acids in Child-favored Foods (어린이 기호식품 중 트랜스지방 및 포화지방 실태조사)

  • Yoon, Tae-Hyung;Lee, Sung-Min;Shin, Hee-Jun;Lee, Soo-Yeon;Hong, Jin;No, Ki-Mi;Park, Kyoung-Sik;Leem, Dong-Gil;Lee, Kwang-Ho;Jeong, Ja-Young
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.40 no.11
    • /
    • pp.1562-1568
    • /
    • 2011
  • We studied the amounts of trans fatty acids and saturated fatty acids in child-favored foods. Confectioneries, breads, donuts and hamburgers were included in this study. The total fatty acid content and the amount of each type of fatty acid were determined by gas chromatography with a flame-ionized detector. Confectioneries were shown to have the highest content of crude fat. The mean content was 24.2${\pm}$6.9 (range: 4.6~41.1) g/100 g food. The mean content of crude fat in donuts, bread and hamburgers was 23.9${\pm}$5.8 (range: 14.1~39.5) g/100 g food, 15.7${\pm}$7.9 (range: 1.4~30.0) g/100 g food, and 9.5${\pm}$3.4 (range: 4.5~18.5) g/100 g food, respectively. Bread had the most trans fatty acids at 1.3 g/100 g food. This result inferred that manufacturers have tried to reduce the trans fat content. The mean content of saturated fatty acids in confectioneries, donuts, bread, and hamburgers was 11.6${\pm}$4.8 (range: 2.0~22.7) g/100 g food, 11.2${\pm}$4.0 (range: 4.8~23.2) g/100 g food, 6.9${\pm}$4.1 (range: 0.6~15.4) g/100 g food, 3.0${\pm}$1.0 (range: 1.0~5.8) g/100 g food, respectively. This content depended on crude fat. The composition of fatty acids varied according to the oil and fat used in the manufacturing process of each food, and the natural content. Foods that were fried in vegetable oil tended to be especially low in saturated fat.

Comparison of the Nutritional and Functional Compounds in Naked Oats (Avena sativa L.) Cultivated in Different Regions (재배지역 차이에 따른 쌀귀리 영양성분 및 기능성 성분 비교)

  • Ji-Hye Song;Dea-Wook Kim;Hak-Young Oh;Jong-Tak Yun;Yong-In Kuk;Kwang-Yeol Yang
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.68 no.4
    • /
    • pp.402-412
    • /
    • 2023
  • To cope with climate change, we compared the quality of naked oats (Avena sativa L.) cultivated in different regions. Naked oats were collected from domestic farms in different cultivation regions grouped as G1 and G2 for 3 years (2020-2022). The appearance, quality, and nutritional and functional compounds in the samples were assessed. In terms of appearance quality, the brightness and yellowness of the samples from the G1 region were significantly lower than those of the samples from the G2 region in 2020; however, no differences were observed between cultivation regions in the other 2 years. The results of testing the vitality of naked oats seeds showed that the electrical conductivity value was significantly lower in the samples from the G1 region than in those from the G2 region only in 2022. Among the nutritional components, moisture content was higher in the G2 region than in the G1 region over all 3 years, and the crude protein content was significantly higher in the G2 region than in the G1 region over all years. Carbohydrate content was significantly higher in the G1 region than in the G2 region in all 3 years and was inversely proportional to the crude protein content. The crude fat content tended to be significantly higher in the G1 region than in the G2 region, except in 2022. The levels of beta-glucan, a functional compound rich in naked oats, ranged between 3.4% and 4.2%, and except in 2020, there was no significant difference between cultivation regions. In addition, the content of avenanthramides, representative functional compounds that exist only in oats, was assessed. Over 2 years, in 2021 and 2022, the avenanthramide content was in the range of 2.4-20.7 ㎍/g and tended to be significantly higher in the G2 region than in the G1 region in both years. According to a survey of the average and minimum temperatures during the growing season of naked oats from 2020 to 2022, the average and minimum temperatures in January in the G2 region, which is the cultivation-limit area, were similar to those in Haenam in the G1 region. In conclusion, differences in nutritional and functional compounds were observed in naked oats grown in different cultivation areas. Therefore, considering the cultivation area of naked oats is expanding because of climate change, changes in the compounds that affect quality should be investigated.

An Experimental Study on Mercury Compounds Poisoning (수은 중독에 관한 실험적 연구)

  • 황인담;기노석;정인호;이정상;이재형
    • Journal of Environmental Health Sciences
    • /
    • v.14 no.1
    • /
    • pp.103-113
    • /
    • 1988
  • This experiment was performed to study the sequential accumulation of mercury in selected tissues of gold fish (Carassius auratus) exposed to 2, 6, 30, 120 and 300 $\mu$g Hg/1 as HgCl$_2$. In order to prepare treatment groups suitable for the present study, one control and five experimental groups, which were composed of I (2 $\mu$g/l), II (6$\mu$g/l), III (30$\mu$g/l), IV (120$\mu$g/l), V (300 $\mu$g/l), were used in 180 liter glass aquaria. The experiment was started by transfering 20 fish of average total length 140 $\pm$ 20 mm to each of the six tanks and allowing the uptake to take place for 12 weeks period. Fish were killed after time periods of 1, 2, 4, 8, and 12 weeks, and samples were disected by five parts gill, kidney liver, muscle and egg. The summarized results were as follows: 1. In control group, low concentrations of mercury(range 0.01-0.11 $\mu$g/g)were determined in the all selected tissues. 2. In experimental group, the average levels of mercury residues in the gill, kidney, liver muscle and egg were 3.61-189.54 $\mu$g/g, 13.91-182.58 $\mu$g/g, 8.56-66.49 $\mu$g/g, 0.30-20.33 $\mu$g/g, and 1.63-23.76$\mu$g/g, respectively. 3. The mercury residues in selected tissues of the experimental group were generally 230-9100 times higher than those of the control group. 4. The amounts of methylmercury per total mercury in the muscle after 12 weeks were 0.10/0.30 $\mu$g/g(33.33%) in the I group, 0.14/1.18$\mu$g/g(11.86%) in the II group, 0.25/5.76 $\mu$g/g(4.34%) in the III group, 0.39/11.48$\mu$g/g(3.40%) in the IV group and 0.40/20.33 $\mu$g/g(1.97%) in the V group.

  • PDF

Evaluation for Rock Cleavage Using Distribution of Microcrack Spacings (III) (미세균열의 간격 분포를 이용한 결의 평가 (III))

  • Park, Deok-Won
    • The Journal of the Petrological Society of Korea
    • /
    • v.25 no.4
    • /
    • pp.311-324
    • /
    • 2016
  • The characteristics of the rock cleavage in Jurassic granite from Geochang were analysed. The evaluation for three quarrying planes and three rock cleavages was performed using the parameters such as (1) reduction ratio between the value of spacing and the value of length, (2) microcrack spacing frequency(N), (3) total spacing($1mm{\geq}$), (4) exponential constant(a), (5) magnitude of exponent(${\lambda}$), (6) mean spacing($S_{mean}$), (7) difference value($S_{mean}-S_{median}$) between mean spacing and median spacing($S_{median}$) and (8) density of spacing. Especially the close dependence between the above spacing parameters and the parameters from the spacing-cumulative frequency diagrams was derived. The discrimination factors representing three quarrying planes and three rock cleavages were acquired through these mutual contrast. The analysis results of the research are summarized as follows. First, the reduction ratios of frequency(N), mean value, median value, the above difference value($S_{mean}-S_{median}$) and density for three rock cleavages are in orders of G(grain, (G1 + G2)/2) < H(hardway, (H1 + H2)/2) < R(rift, (R1 + R2)/2), H < G $\ll$ R, H < G $\ll$ R, H < G < R and H < G $\ll$ R. The values of the above five parameters for three planes show the various orders of R'(rift plane) $\ll$ H'(hardway plane) < G'(grain plane), R' $\ll$ G' < H', R' < H' < G', R' < G' < H' and R' $\ll$ H' < G', respectively. Second, the values of (I) parameters(2, 3, 4 and 5) and (II) parameters(6, 7 and 8) are in orders of (I) H < G < R and (II) R < G < H. On the contrary, the values of the above two groups(I~II) of parameters for three planes show reverse orders. Third, to review the overall characteristics of the arrangement among the six diagrams, these diagrams show an order of R2 < R1 < G2 < G1 < H2 < H1 from the related chart. In other words, above six diagrams can be summarized in order of rift(R1 + R2) < grain(G1 + G2) < hardway(H1 + H2). These results indicate a relative magnitude of rock cleavage related to microcrack spacing. Especially, two parameters for each diagram, the above difference value($S_{mean}-S_{median}$) and mean spacing, could provide advanced information for prediction the order of arrangement among the diagrams. Finally, the general chart for three planes and three rock cleavages were made. From the related chart, three exponential straight lines for three rock cleavages show an order of R(R1 + R2) < G(G1 + G2) < H(H1 + H2). On the contrary, three lines for three planes show an order of H'(R2 + G2) < G'(R1 + H2) < R'(G1 + H1). Consequently, correlation of the mutually reverse order between three planes and three rock cleavages can be drawn from the related chart.

The inhibitory activity of ginsenoside Rp4 in adenosine diphosphate-induced platelet aggregation

  • Son, Young-Min;Jeong, Da-Hye;Park, Hwa-Jin;Rhee, Man-Hee
    • Journal of Ginseng Research
    • /
    • v.41 no.1
    • /
    • pp.96-102
    • /
    • 2017
  • Background: Korean ginseng, Panax ginseng Meyer, has been used as a traditional oriental medicine to treat illness and promote health for several thousand years. Ginsenosides are the main constituents for the pharmacological effects of P. ginseng. Since several ginsenosides, including ginsenoside (G)-Rg3 and G-Rp1, have reported antiplatelet activity, here we investigate the ability of G-Rp4 to modulate adenosine diphosphate (ADP)-induced platelet aggregation. The ginsenoside Rp4, a similar chemical structure of G-Rp1, was prepared from G-Rg1 by chemical modification. Methods: To examine the effects of G-Rp4 on platelet activation, we performed several experiments, including antiplatelet ability, the modulation of intracellular calcium concentration, and P-selectin expression. In addition, we examined the activation of integrin ${\alpha}IIb{\beta}_3$ and the phosphorylation of signaling molecules using fibrinogen binding assay and immunoblotting in rat washed platelets. Results: G-Rp4 inhibited ADP-induced platelet aggregation in a dose-dependent manner. We found that G-Rp4 decreased calcium mobilization and P-selectin expression in ADP-activated platelets. Moreover, fibrinogen binding to integrin ${\alpha}IIb{\beta}_3$ by ADP was attenuated in G-Rp4-treated platelets. G-Rp4 significantly attenuated phosphorylation of extracellular signal-regulated protein kinases 1 and 2, p38, and c-Jun N-terminal kinase, as well as protein kinase B, phosphatidylinositol 3-kinase, and phospholipase C-${\gamma}$ phosphorylations. Conclusion: G-Rp4 significantly inhibited ADP-induced platelet aggregation and this is mediated via modulating the intracellular signaling molecules. These results indicate that G-Rp4 could be a potential candidate as a therapeutic agent against platelet-related cardiovascular diseases.