• Title/Summary/Keyword: low density

Search Result 7,820, Processing Time 0.047 seconds

Dynamics of Water Environmental Factors and Phytoplankton in Taechong Reservoir (대청호에서 수환경 요인과 식물플랑크톤의 변동)

  • 신재기;조경제;오인혜
    • Korean Journal of Environmental Biology
    • /
    • v.17 no.4
    • /
    • pp.529-541
    • /
    • 1999
  • In order to elucidate characteristics of water quality, investigation of monthly dynamics of environmental factors and algal populations at major four stations of the mid and lower part in Taechong Reservoir was performed from June 1998 to June 1999. Water temperature, DO and pH were ranged 5.3~27.7$^{\circ}C$, 6.2~13.8 mgO$_2$/1 and 6.4~9.5, respectively. Those were varying as the season changes. Among inorganic nitrogen nutrients, NH$_4$was ranged from 5.5% to 7.2% of NO$_3$and NO$_3$was almost same through the seasons except summer in which it was low. SRP and SRSi were increased in summer when the blue-green algae became dominant. Those were decreased as the cell density of diatom increased when the water temperature dropped. Therefore SRSi was considered to be another important nutrient factor contributing to the increment of biomass of freshwater algae as well as SRP. Average chi-$\alpha$ concentration ranged from s to 12 $\mu$g/1 and in the lower part or the reservoir, the lowest was found. Moreover, there were remarkable increment in summer when TN/TP ratio were decreasing from relationships between TN/TP ratio and chi-$\alpha$ concentration. Annual mean ratio of TN/TP ratio was relatively high as the value was 110, which was relatively high, and it showed that P is the dominant factor in the algal growth. The dynamics of phytoplankton were simply dominated by a few species seasonally. In summer, blue -green algae such as Anabaena, Microcystis and Oscillatoria were dominant and algal bloom of blue -green began from early summer, sustained to late autumn. The average standing crops of A. spiroides v. crassa, M. aeruginosa and O. limosa were ranged 0.3~2.0$\times$10$^4$cells/ml, 6.4$\times$10$^2$~1.0$\times$10$^4$cells/ml and 4.6$\times$10$^3$~1.6$\times$10$^4$cells/ml, respectively. In winter, diatom Stephanodiscus was considered to be an important species whose average standing crops of Stephunodiscus was 4.9$\times$10$^2$cells/ml from November to April of the next year and the highest was 1.3$\times$10$^3$cells/ml in January.

  • PDF

DRAG EFFECT OF KOMPSAT-1 DURING STRONG SOLAR AND GEOMAGNETIC ACTIVITY (강한 태양 및 지자기 활동 기간 중에 아리랑 위성 1호(KOMPSAT-1)의 궤도 변화)

  • Park, J.;Moon, Y.J.;Kim, K.H.;Cho, K.S.;Kim, H.D.;Kim, Y.H.;Park, Y.D.;Yi, Y.
    • Journal of Astronomy and Space Sciences
    • /
    • v.24 no.2
    • /
    • pp.125-134
    • /
    • 2007
  • In this paper, we analyze the orbital variation of the Korea Multi-Purpose SATellite-1(KOMPSAT-1) in a strong space environment due to satellite drag by solar and geomagnetic activities. The satellite drag usually occurs slowly, but becomes serious satellite drag when the space environment suddenly changes via strong solar activity like a big flare eruption or coronal mass ejections(CMEs). Especially, KOMPSAT-1 as a low earth orbit satellite has a distinct increase of the drag acceleration by the variations of atmospheric friction. We consider factors of solar activity to have serious effects on the satellite drag from two points of view. One is an effect of high energy radiation when the flare occurs in the Sun. This radiation heats and expands the upper atmosphere of the Earth as the number of neutral particles is suddenly increased. The other is an effect of Joule and precipitating particle heating caused by current of plasma and precipitation of particles during geomagnetic storms by CMEs. It also affects the density of neutral particles by heating the upper atmo-sphere. We investigate the satellite drag acceleration associated with the two factors for five events selected based on solar and geomagnetic data from 2001 to 2002. The major results can be summarized as follows. First, the drag acceleration started to increase with solar EUV radiation with the best cross-correlation (r = 0.92) for 1 day delayed F10.7. Second, the drag acceleration and Dst index have similar patterns when the geomagnetic storm is dominant and the drag acceleration abruptly increases during the strong geomagnetic storm. Third, the background variation of the drag accelerations is governed by the solar radiation, while their short term (less than a day) variations is governed by geomagnetic storms.

Structure and Physical Property of the Crust of Mid-west Korea: Analysis of Sedimentary Basins in the Namyang and Tando Areas, Kyeonggi Province, Korea (한반도 중서부 지각구조와 물성 연구: 경기도 화성군 남양 및 안산시 탄도지역에 분포하는 퇴적분지의 분석)

  • Park, Sung-Dae;Chung, Gong-Soo;Jeong, Ji-Gon;Kim, Won-Sa;Lee, Dong-Woo;Song, Moo-Young
    • Journal of the Korean earth science society
    • /
    • v.21 no.5
    • /
    • pp.563-582
    • /
    • 2000
  • Two Cretaceous(80-90 Ma) non-marine sedimentary basins, Namyang and Tando Basins, are distributed in the Namyang area, Hwaseonggun and in the Tando area, Ansanshi, Kyungki Province, Korea. The Namyang and Tando Basins are composed of 10 facies, which are pooped into 5 facies associations(FA). FA I consists of massive conglomerate facies, normally graded conglomerate facies and reversely graded conglomerate facies, which is interpreted to have been formed by laminated sandstone facies, massive conglomerate facies(channelized), which is thought to have been formed by sheet flow, stream flow and suspension sedimentation in an alluvial/braided plain environment. FA III consists of massive mudstone(pebbly) facies, laminated mudstone facies, massive sandstone facies and is interbedded by channel-fill conglomerate. It is interpreted to have been deposited by suspension settling during flooding and channel-fill deposition in a floodplain environment. FA IV consists of massive conglomerate facies, normally graded conglomerate facies, massive sandstone facies, normally graded sandstone facies, and laminated sandstone facies and is interbedded with mudstone facies. It is thought to have been deposited by debris flow and turbidity current in a fan-delta environment. FA V consists of massive mudstone facies, laminated mudstone facies, laminated sandstone facies and is interbedded by massive conglomerate bed. It is thought to have been formed by suspension sedimentation and low-density turbidity current in a lake. In the Namyang Basin FA I is distributed in the eastern and southern margin of the basin, FA II in the middle part of the basin as north-south tending band. and FA III in the western part. In the Tando Basin FA II is distributed in the middle part of eastern margin and in the northwestern margin, FA IV in the southwestern part, and FA V in the central part. Correlation of the facies associations shows that FA I and II in the Namyang Basin are distributed in the lower to middle part of stratigraphic sequence and FA III in the upper part of the sequence whereas FA II and IV in the Tando Basin are in the lower to middle part and FA V in the upper part of the sequence. These patterns of facies associations distribution suggest that the Namyang Basin was developed as an alluvial fan and alluvial/braided plain at first and then evolved into a floodplain whereas the Tando Basin was developed as a fan-delta and alluvial/braided plain at first and then evolved into a lake environment.

  • PDF

Metabolites profiling and hypolipidemic/hypocholesterolemic effects of persimmon (Diosyros kaki Thumb.) by different processing procedures: in vitro and in vivo studies (제조방법에 따른 떫은감 (Diosyros kaki Thumb.)의 대사체 프로파일링과 중성지질/콜레스테롤 대사 관련 유전자발현 연구 : in vitro 및 in vivo 연구)

  • Park, Soo-Yeon;Oh, Eun-Kyung;Lim, Yeni;Shin, Ji-Yoon;Jung, Hee-Ah;Park, Song-Yi;Lee, Jin Hee;Choe, Jeong-Sook;Kwon, Oran
    • Journal of Nutrition and Health
    • /
    • v.51 no.4
    • /
    • pp.275-286
    • /
    • 2018
  • Purpose: Our previous study demonstrated that persimmon (Diospyros kaki Thumb.) at different stages of ripening provided different protective effects against high-fat/cholesterol diet (HFD)-induced dyslipidemia in rats. In this study, we compared the metabolites profile and gene expressions related to triglyceride (TG)/cholesterol metabolism in vitro and in vivo after treating with persimmon water extracts (PWE) or tannin-enriched persimmon concentrate (TEP). Methods: Primary and secondary metabolites in test materials were determined by GC-TOF/MS, UHPLC-LTQ-ESI-IT-MS/MS, and UPLC-Q-TOF-MS. The expression of genes related to TG and cholesterol metabolism were determined by RT-PCR both in HepG2 cells stimulated by oleic acid/palmitic acid and in liver tissues obtained from Wistar rats fed with HFD and PWE at 0, 150, 300, and 600 mg/d (experiment I) or TEP at 0, 7, 14, and 28 mg/d (experiment II) by oral gavage for 9 weeks. Results: PLS-DA analysis and heatmap analysis demonstrated significantly differential profiling of metabolites of PWE and TEP according to processing of persimmon powder. In vitro, TEP showed similar hypolipidemic effects as PWE, but significantly enhanced hypocholesterolemic effects compared to PWE in sterol regulatory element-binding protein 2 (SREBP2), HMG-CoA reductase (HMGCR), proprotein convertase subtilisin/kexin type 9 (PCSK9), cholesterol $7{\alpha}-hydroxylase$ (CYP7A1), and low density lipoprotein receptor (LDLR) gene expression. Consistently, TEP and PWE showed similar hypolipidemic capacity in vivo, but significantly enhanced hypocholesterolemic capacity in terms of SREBP2, HMGCR, and bile salt export pump (BSEP) gene expression. Conclusion: These results suggest that column extraction after hot water extraction may be a good strategy to enhance tannins and long-chain fatty acid amides, which might cause stimulation of hypocholesterolemic actions through downregulation of cholesterol biosynthesis gene expression and upregulation of LDL receptor gene expression.

Effect of the Concentration of Humic Acid on Growth and Yield of Organically Cultivated Hot-Pepper (휴믹산 농도가 유기농 고추의 생육 및 수량에 미치는 영향)

  • Kim, Min-Jeong;Shim, Chang-Ki;Kim, Yong-Ki;Park, Jong-Ho;Han, Eun-Jung;Ko, Byong-Gu
    • Journal of the Korea Organic Resources Recycling Association
    • /
    • v.25 no.1
    • /
    • pp.67-78
    • /
    • 2017
  • The purpose of this study was to investigate the effect of humic acid on the germination, the growth and the yield of hot pepper when treated with organic hot pepper seedlings and growing season. The germination rate of 0.05% and 0.1% humic acid was higher than that of untreated, but the germination rates of 0.4% and 1.0% humic acid were 90.0% and 86.7%, respectively, compared with the control treatment (96.7%). At 30 days after transplanting, hot pepper treated with low (0.05%) or high (1.0%) concentration of humic acid decreased the growth of hot pepper seedlings, whereas 0.2% humic acid treatment significantly increased a average height (97.6 cm), leaf number (84.7) and fresh weight ($128.1g\;plant^{-1}$) of hot pepper. After 60 days of treatment with humic acid, the height of hot pepper was significantly longer in 0.2% humic acid. The mean green fruit number of 0.2%, 0.1% and 0.05% humic acid were not significantly different among the treatments, but the mean green pepper number of 0.4% and 1.0% humic acid treatments were the higher with 35.2% and 29.1%, respectively than other treatments. However, the fresh weight of green pepper was found to be $111.5g\;plant^{-1}$ more heavier than the untreated in 0.2% humic acid. The total ($5.8kg\;plant^{-1}$) and average ($1.4kg\;plant^{-1}$) fresh weight of pepper were higher than that of untreated control, except for the 1.0% humic acid treatment after 60 days of soil irrigation. The total weight of hot pepper treated with 0.2% and 0.1% humic acid treatment was $9.3kg\;plant^{-1}$ and $8.6kg\;plant^{-1}$, respectively, which were heavier than the other treatments. The effect of humic acid concentrations on soil microbial populations, pH and EC was investigated. The soil bacterial population density of 0.2% humic acid treatment was 3.5 times higher than that of untreated control soil. As the concentration of humic acid increased from 0.05% to 1.0%, pH and EC of hot pepper grown soil also increased.

Broden photographing method for Calcaneus Subtentaculum tali observation of Ankle plaster patient (발목부상을 당한 석고환자의 발꿈치뼈·목말받침돌기 관찰을 위한 Broden 촬영법 연구)

  • An, Byeongju
    • Journal of the Korean Society of Radiology
    • /
    • v.7 no.2
    • /
    • pp.107-112
    • /
    • 2013
  • There is an Ankle Oblique(Broden' low) as an examination for the patient whose ankle was encased in orthopedic plaster. Some types of Ankle Joint coalition - Calcaneonavicular coalition, Talocalcaneal coalition and Naviculocuneiform coalition. This study is focused on the relation between Ankle Joints and the structural change of soft tissues, also finding the most proper angle to obtain good images of Ankle Joint from the patient who wore a plaster on his ankle, when we x-ray with Harris-Beath View($30^{\circ}{\sim}55^{\circ}$) - for observing Subtalar joint, Calcaneus Fracture, Subtentaculum, Tali Fracture and Talocalcaneal coalition. We intend to get the angle which makes us achieve the good image that shows Calcaneus Fracture, Subtentaculum, and Tali Fracture by changing internal angles of the patient's ankle. We evaluated the images obtained from 51 patients with PACS monitor. The result of the evaluation, subtalar joint was not seperated but opened, and Subtentaculum Tali Fracture was seen overlaid. at the angle 30, we could observe Calcaneus Fracture, Subtentaculum Tali Frature and the front part of behind side of subtalar joint well. And Calcaneo Navicularcoalition, Talocal Canealcoalition, Naviculo Cuneiform coalition condition were clearly seen at that angle. At the angle 35, we could achieve the clear images of subtalar comminuted fracture, talus, the behind joint of heel bone and get the high definition image on the degree of talocalcaneal joint separation. In addition to, We could obtain the good wide image of Sinus Tarsi. At the area of 45, We can distinguish the soft tissues from gyps separation. The outer-talus and density of the bone were definitely seen and Calcaneus is more separated than that of at the angle of 35, but this image is distorted. Calcaneus, Subtentaculum Tali show $1.20{\pm}0.414$ at the angle 25, $2.47{\pm}0.516$ at the angle 30, $2.27{\pm}0.458$ at the angle 45. This difference is statistically meaningful. (p<0.05). Including the degree of distortion, The distortion appears less at the area of $30^{\circ}$ but at the area of 40, there is heavy distortion. So, We could get the best image for making a diagnosis. At the $30{\sim}35^{\circ}$ degree for X-raying ankle. and at the $30{\sim}40^{\circ}$ for Calcaneus Fracture, Subtentaculum Tali Fracture.

Evaluation of Nutritional Status among Primary School Children in Uganda: Comparison of Urban and Rural Areas (우간다 초등학생의 영양섭취 실태조사: 도심지역과 농촌지역의 비교)

  • Lee, Ji-Yeon;Park, Hye-Jung;Yu, Min;Hwang, Ha-Yeong;Sung, Jung-Rim;Kim, Hee-Seon
    • Korean Journal of Community Nutrition
    • /
    • v.25 no.2
    • /
    • pp.91-101
    • /
    • 2020
  • Objectives: The aim of this study was to investigate dietary intakes and nutritional status among Uganda primary school children from two selected schools in urban and rural areas. Methods: Data were collected from 350 pupils (6-14 years) in Mpigi district, Uganda. All participants were offered a school lunch meal (usually maize porridge and boiled beans). Dietary survey was conducted in October 2016. Data for dietary intake levels were collected by the 24-hour recall method with trained school staffs. The data were converted into nutrient intakes using the CAN-Pro 5.0 Program and compared with KDRIs to evaluate the nutritional status of the subjects. Diet quality indexes such as nutrient density, nutrient adequacy ratio (NAR), mean adequacy ratio (MAR), and index of nutritional quality (INQ) and a diet diversity index such as diet diversity score (DDS) were calculated to evaluate nutritional status among subjects. Data were analyzed using SPSS statistical programs. Results: Results show that the intakes of most nutrients were significantly different by schools. The nutritional status of micro-nutrients was very low in both schools according to analysis of nutritional indexes such as NARs and INQs. Students from both schools should improve intakes of micro-nutrients related to child growth such as calcium, Vitamin B6, zinc and folate. According to the analysis of dietary diversity, there was difference in dietary patterns by schools presumably due to their locations. Conclusions: This suggests that current meals could not provide adequate nutrients for the subjects and urgent nutrition interventions for school food services are needed to improve their nutritional well-being. New foods supplements based on local cuisine are also needed to ensure dietary diversity and sustainable development plans.

Rice Growth and Yield at Different Cultural Methods under No-tillage Condition (벼 무경운 재배시 재배양식에 따른 생육 및 수량)

  • 박홍규;김상수;백남현;석순종;박건호;이선용
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.41 no.4
    • /
    • pp.420-428
    • /
    • 1996
  • This study was conducted to investigate the response of growth and yield of rice under five different cultural methods, machine transplanting(MTNT), puddled drill seeding (PDSNT), drill seeding on soil surface (DSNT) , broadcasting on soil surface (BSNT) under no-tillage paddy condition and conventional machine transplanting(MTT) in Jeonbuk series(siltyloam soil) from 1993 to 1995. Soil hardness was higher in no-tillage soil and increased with highly difference between tillaged and no-tillage soil with deeper soil depth. Bulk density was heavier in no-tillage soil and porosity was higher in tilled soil than that of the control. The rate of effective tiller was higher in MTT, following MTNT, PDSNT, DSNT and BSNT. Weed occurrence was more serious in no-tillage soil, than that of tillaged soil. The rate of lower internode length was lower in DSNT and BSNT and was similar with MTT in PDSNT and MTNT. Height of center gravity in terms of lodging tolerance was lower in direct seeding than in machine transplanting. Depth of buried culm was shorter in no-tillage soil, especially in DSNT and BSNT. Total amount of root was higher in MTT, following MTNT, PDSNT, BSNT and BSNT and the distribution rate of root in shallower soil layer was higher in no-tillage soil, especially in BSNT and DSNT. Field lodging occured highly in BSNT, following DSNA, PDSNT and MTNT with high lodging scale in DSNT and BSNT. Panicle number per unit land square meter was the highest in MTT and the least in BSNT. Ripened grain ratio was low in BSNT and DSNT due to heavy lodging. Yield of milled rice was 93% in PDSNT, 87% in DSNT, 81% in BSNT and 96% in MTNT, compared with 534kg /10a in MTT.

  • PDF

Evaluation of the Shear Strength and Stiffness of Frozen Soil with a Low Water Content (함수비가 낮은 동결토의 전단강도 및 강성 평가)

  • Kim, Sang Yeob;Lee, Jong-Sub;Kim, Young Seok;Byun, Yong-Hoon
    • The Journal of Engineering Geology
    • /
    • v.25 no.1
    • /
    • pp.93-102
    • /
    • 2015
  • The characteristics of frozen soils are one of most important factors for foundation design in cold region. The objective of this study is to evaluate the shear strength and stiffness of frozen soils according to the confining conditions during the freezing and shearing phase. A direct shear box is constructed for the frozen specimens and bender elements are mounted on the wall of the shear box to measure shear wave velocities. Specimens are prepared by mixing sand and silt with a silt fraction of 30% in weight and the degree of saturation of 10%, giving a relative density of 60% for all tests. The temperature of the specimens in the freezer is allowed to fall below -5℃, and then direct shear tests are performed. A series of vertical stresses are applied during the freezing and shearing phase. Shear stress, vertical displacement, and shear wave along the horizontal displacement are measured. Experimental results show that in all the tests, shear strength increases with increasing vertical stress applied during the freezing and shearing phases. The magnitude of the increase in shear strength with increasing vertical stress during shearing under fixed vertical stress in the frozen state is smaller than the magnitude of the increase in vertical stress during freezing and shearing. In addition, the change in shear wave velocities varies with the position of the bender elements. In the case of shear waves passing through the shear plane, the shear wave velocities decrease with increasing horizontal displacement. This study provides an evaluation of the properties of shear strength and stiffness of frozen soils under varied confining condition.

Serum Adiponectin Levels and Insulin Resistance in Obese Children (비만 소아의 혈중 아디포넥틴과 인슐린저항성에 관한 연구)

  • Lee, Hee-Sun;Lee, Jin;Kang, Min-Joo;Choi, Byung-Min;Lee, Kee-Hyoung
    • Clinical and Experimental Pediatrics
    • /
    • v.48 no.5
    • /
    • pp.481-487
    • /
    • 2005
  • Purpose : Adiponectin, adipose tissue-specific protein, has anti-inflammatory and anti-atherogenic properties. It has been found to have a negative correlation with obesity and to play a role in modulating glucose tolerance and insulin sensitivity. Serum adiponectin concentrations are decreased in adults with obesity and type 2 diabetes. We investigated the difference in adiponectin levels between obese and non-obese children, and evaluated the relationship of serum adiponectin with body mass index(BMI), serum fasting insulin, lipid profiles and homeostasis model assessment(HOMA) in children. Methods : We measured serum adiponectin levels by radioimmunoassay in 113 children(82 obese children and 31 non-obese controls) from 8 to 15 years of age, and also checked BMI, fasting serum glucose, insulin and lipid profiles. Fasting and postprandial serum adiponectin concentrations were compared by oral glucose tolerance tests in 27 obese children. The correlations of adiponectin with BMI, insulin, low density lipoprotein(LDL)-cholesterol and HOMA were analyzed by Pearson's correlation. Results : The serum adiponectin levels were significantly lower in the obese group(19.7 mg/mL) than in the non-obese group(27.5 mg/mL)(P<0.01). Serum adiponectin concentrations were negatively correlated with BMI(r=-0.39, P<0.01), serum insulin(r=-0.28, P<0.01), LDL-C(r=-0.20, P<0.01) and HOMA(r=-0.22, P<0.01). At oral glucose tolerance tests in obese children, postprandial 2 hours adiponectin level(19.8 mg/mL) was decreased compared to fasting level(25.8 mg/mL)(P<0.01). Conclusion : Serum adiponectin concentrations were inversely related to adiposity and insulin resistance in children. We suggest the serum adiponectin level could be used as an early marker of insulin resistance in obese children.