• Title/Summary/Keyword: MgO(001)

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Effects of Environmental Factors on Phytoplankton Communities in the Marine Ranching Ground of Tongyeong Coastal Waters, Korea (통영 바다목장 해역에서 식물플랑크톤군집에 미치는 환경요인의 영향)

  • Lee, Jin-Hwan;Jung, Seung-Won;Kim, Jong-Man
    • Ocean and Polar Research
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    • v.27 no.1
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    • pp.15-24
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    • 2005
  • In order to investigate the structures and dynamics of phytoplankton communities, each physicochemical environmental factor, species composition, standing crop, and dominant species were examined in the marine ranching ground of Tongyeong coastal waters from April to October, 2000. During the studies, mean water temperature and salinity were $18.8^{\circ}C$ and 33.1 psu, respectively. DO, SS and transparency varied from 5.43 to 11.39 mg/l, 14.6 to 32.4mg/l and 3.5 to 9.0m, respectively. Light intensities varied from 0.02 to $966{\mu}E/m^2/s$, which decreased with depth. $NH_4-N,\;NO_3-N,\;NO_2-N,\;PO_4-P,\;and\;SiO_2-Si$ were fluctuated from 0.059 to 0.332 mg/l, 0.040 to 0.800 mg/l, 0.001 to 0.468 mg/l, 2.3 to $143.0{\mu}g/l$, and 0.007 to 0.600 mg/l, respectively. chlorophyll a concentrations were fluctuated from 0.7 to $8.9{\mu}g/l$. Among 130 taxa of phytoplankton communities observed. diatoms occupied more than 81.54% of the total species, and the others were dinoflagellates and silicoflagellates. Phytoplankton standing crops ranged from $4.6{\times}10^4\;to\;2.6{\times}10^6cells/l$. In October, the standing crops were at bloom level showing more than $10^6cells/lat$ all stations. Dominant species changed by month and station. Leptocylindrus danicus occupied 59.84% in April and 22.03% in June. Pseudo-nitzschia pungens in August and Chaetoceros socialis and Skeletonema costatum in October were predominant species. In order to investigate factors influencing the total phytoplankton standing crops the correlations between the standing crops of diatoms, dinoflagellates, all phytoplanktons occurred and environmental factors were calculated using a multiple regression analysis. The coefficient of determination $(R^2)$ for total standing crops was 0.63 which explained 63% of variance and that of $R^2$ for diatom was 0.82. In statistical analysis, the results showed that the environmental factors influencing the size of the communities were predominantly water temperature, salinity and silicate.

Effects of Soil Addition and Subsoil Plowing on the Change of Soil Chemical Properties and the Reduction of Root-Knot Nematode in Continuous Cropping Field of Oriental Melon (Cucumis melo L.) (시설참외 연작재배지 토양의 객토 및 심토반전이 토양 화학성 변화와 토양선층 억제효과에 미치는 영향)

  • Jun, Han-Sik;Park, Woo-Chul;Jung, Jae-Sik
    • Korean Journal of Environmental Agriculture
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    • v.21 no.1
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    • pp.1-6
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    • 2002
  • To elucidate the effect of soil addition and subsoil plowing on the change of sell chemical properties and the reduction of root-knot nematode, this experiment carried out in continuous cropping field of protected oriental melon (Cucumis melo L.). Soil addition reduced electric conductivity (E. C.) from 4.3 to 1.8 dS/m (58%), available $P_2O_5$ from 406 to 182 mg/kg (55%) and organic matter content from 16 to 11 g/kg (31%). Population densities of root-knot nematode in soil reduced as much as 89%, 84%, and 69% at first year, third years, and of five years later, respectively The effects of subsoil plowing were similar to that of soil addition. E. C. and phosphate were reduced from 4.30 to 1.98 dS/m (54%) and phosphate from 406 to 329 mg/kg (19%), respectively. Population densities of root-knot nematode reduced as much as 71%, 67%, and 42% after 1, 3, and 5 years, respectively Subsoil plowing reduced nematode densities only for three years.

Physicochemical and Physiological Activities of Garlic from Different Area (산지별 마늘의 이화학적 특성 및 생리활성 작용)

  • Shin Jung-Hye;Ju Jong-Chan;Kwen O-Chen;Yang Sung-Mi;Lee So-Jung;Sung Nak-Ju
    • The Korean Journal of Food And Nutrition
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    • v.17 no.3
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    • pp.237-245
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    • 2004
  • The physicochemical and physiological activities of domestic garlic from 3 different areas (Namhae, Jeju and Uiseong) were analyzed. The contents of moisture, ash, crude protein and crude fiber in garlic were little different in 3 kinds of area. Total sugar and water soluble phenolic compounds were higher in garlic from Namhae. The free sugars found in garlic were fructose, sucrose and lactose. Five kinds of organic acids were determined. Malonic acid and citric acid contents in garlic from Namhae were 23.7${\pm}$1.16 mg% and 22.1${\pm}$0.82 mg%, respectively. Total mineral content of garlic samples were in a range of 7112.6~9067.3 mg%, the potassium content showed the highest concentration (4117.3${\pm}$7.19~5175.3${\pm}$9.61 mg%). The electron donating abilities in 0.2% of garlic from Namhae and Uiseong showed 46.2${\pm}$1.25% and 37.0${\pm}$1.l6%, respectively. The nitrite scavenging effect was measured at different conditions (pH 1.2 and 4.2). The nitrite scavenging effects were higher at pH 1.2, and reached more than 95% by adding 0.2% and 0.1 % of garlic juice at pH 1.2. Addition 0.02~0.001 % garlic juice in showed the SOD-like activities. Its activity of garlic from Namhae. was a range of 6.0${\pm}$0.37~14.4~0.69%. It was found that 0.2% and 0.1% garlic showed strong antimicrobial action against growth of all the tested bacteria. Antimicrobial action. was showed 74.7${\pm}$0.70% and 51.7${\pm}$1.l1% on Sal. typhimurium in 0.2% of garlic from Namhae and Uiseong and 28.6${\pm}$0.90% on B. subtilis in garlic from Jeju.

Determination of Liquid Paraffins in Foods by Using GC-FID (GC-FID를 이용한 식품 중 유동파라핀 함량 분석)

  • Park, Se-Jong;Choi, Jae-Chun;Lim, Ho-Soo;Jang, Su-Jin;Kim, So-Hee;Kim, Meehye
    • Korean Journal of Food Science and Technology
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    • v.45 no.5
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    • pp.545-549
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    • 2013
  • Liquid paraffin is a mixture of heavier alkanes derived from petroleum. It can be used as a lubricant in processing machinery, as a coating agent, or as a releasing agent. The purpose of this study was to analyze liquid paraffins in foods by using a gas chromatography-flame ionized detector (GC-FID). Liquid paraffin was extracted from the food samples using n-hexane. Non-polar aromatic or olefinic co-extractives were removed by alkaline permanganate oxidation followed by clean up on an aluminium oxide SPE cartridge before the GC-FID analysis. The results of recovery tests were 91.5-103.2%. Based on this optimized method, we investigated the amount of liquid paraffin in various food samples purchased from domestic markets. The levels of liquid paraffin in bread were $95.5{\pm}156.0$ mg/kg (0.008%), those in capsules were $40.2{\pm}54.5$ mg/kg (0.001%), and those in dried fruits and vegetables were $3.0{\pm}18.1$ mg/kg (0.0001%). No liquid paraffin was detected in fresh fruits and vegetables. We propose that our method can be used to monitor and detect liquid paraffin in foods for food safety management.

Antidepressant Effects of Gammakdaejo-Tang on Repeated Immobilization Stress in the Ovariectomized Female Rats

  • Park, Hyun-Jung;Shim, Hyun-Soo;Lee, Hye-Jung;Yun, Young-Ju;Shim, In-Sop
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.25 no.5
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    • pp.876-880
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    • 2011
  • Gammakdaejo-Tang (GMT) is a traditional oriental medicinal formula, a mixture of 3 crude drugs, and it has been clinically used for treating mild depressive disorders. The purpose of the study was to examine the effect of Gammakdaejo-Tang (GMT) on repeated stress-induced alterations of learning and memory on a passive avoidance test (PAT) test and also the anxiety-related behavior on the elevated pulse maze (EPM) in ovariectomized female rats. We assessed the changes in the reactivity of the cholinergic system by measuring the immunoreactive neurons of choline acetyltransferase (ChAT) in the hippocampus after behavioral testing. The rats were exposed to the immobilization (IMO) stress for 14 days (2hours/day), and Gammakdaejo-Tang (400 mg/kg, p.o.) was administered 30 min before IMO stress. Treatments with GMT caused significant reversals of the stress-induced deficits in learning and memory on a working memory test, and it also produced an anxiolytic-like effect on the EPM, and increased the ChAT reactivities (p<0.001, respectively). These results suggest that Gammakdaejo-Tang might prove to be an effective antidepressant agent.

The Effect of Cr Dosage on FePt Nanoparticle Formation

  • Won, C.;Keavney, D.J.;Divan, R.;Bader, S.D.
    • Journal of Magnetics
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    • v.11 no.4
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    • pp.182-188
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    • 2006
  • The search for high-density recording materials has been one of most active and vigorous field in the field of magnetism. $FePt-L1_{0}$ nanoparticle has emerged as a potential candidate because of its high anisotropy. In this paper, we provide an overview of recent work at Argonne National Laboratory that contributes to the ongoing dialogue concerning the relation between structure and properties of the FePt nanoparticle system. In particular we discuss the ability to control structure and properties via dosing with Cr. Cr-dosed FePt films were grown via molecular beam epitaxy and annealed at $550^{\circ}C$ in an ultrahigh vacuum chamber, and were studied with the surface magneto-optic Kerr effect (SMOKE), scanning electron microscopy (SEM) and x-ray magnetic circular dichroism (XMCD). We found that small dosage of Cr helps to generate $L1_{0}$ phase FePt magnetic nanoparticles with small size, defined shape and regular spatial distribution on MgO (001) substrate. The nanostructures are ferromagnetic with high magnetic coercivity (${\sim}0.9T$) and magnetic easy axis in the desired out-of-plane orientation. We also show that controlling the lateral region where nanostructures exist is possible via artificial patterning with Cr.

Progress in research and development for REBCO coated conductors by reactive co-evaporation

  • Oh, S.S.;Kim, H.S.;Ha, H.S.;Ko, R.K.;Ha, D.W.;Lee, H.;Moon, S.H.;Yoo, S.I.
    • Progress in Superconductivity and Cryogenics
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    • v.15 no.4
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    • pp.1-5
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    • 2013
  • This paper reviews recent progress in research and development (R&D) of reactive co-evaporation for high performance REBCO coated conductors in Korea. Two types of reactive co-evaporation methods were developed for the deposition of SmBCO and GdBCO superconducting layers respectively on the IBAD (Ion Beam Assisted Deposition)-MgO template in the Korean coated conductor project. Batch type reactive co-evaporation equipment and its processing were developed for SmBCO coated conductors at Korea Electrotechnology Research Institute (KERI) in conjunction with the Korea Advanced Institute of Science and Technology (KAIST), and a very high critical current exceeding 1,000 A/cm at 77 K in the self field was achieved through the optimization of deposition parameters. Reel-to-reel type reactive co-evaporation processing with a high conversion rate was also developed, while long length GdBCO coated conductors have been routinely produced by SuNAM Co. The minimum critical current of 422 A/cm-w at 77 K in self field was confirmed for 1 km-long GdBCO tape.

Protective Effect of Rhodiola sachalinensis A. Bor on Excessive Exercise Stress (홍경천의 과도한 운동스트레스에 대한 방어효과)

  • Lee, Yeonmi;Hong, Hee-Do;Choi, Sang Yoon
    • Journal of Applied Biological Chemistry
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    • v.56 no.1
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    • pp.1-3
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    • 2013
  • Rhodiola sachalinensis A. Bor is a plant naturally grows in a high mountain areas. Aim of this study was to evaluate the effects of R.sachalinensis A. Bor extract against excessive exercise induced stress. R.sachalinensis A. Bor extract significantly inhibited L6 muscle cell death and ATP reduction caused by $H_2O_2$ damage. In addition, the oral administration of R. sachalinensis A. Bor extract in mice improved the 43.9% of treadmill running time and blood profiles of glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, lactate dehydrogenase, creatinine, lactate when compared to distilled water. These results suggested that R. sachalinensis A. Bor can attenuate excessive exercise induced damage.

The Effects of Dai-saiko-to (Da-Chai-Hu-Tang) on 3T3-L1 Preadipocytes and High-Fat Diet-Induced Obese Mice (대시호탕(大柴胡湯)이 3T3-L1 지방전구세포와 고지방식이 유도 비만쥐에 미치는 영향)

  • Min, Deul Le;Park, Eun Jung
    • The Journal of Pediatrics of Korean Medicine
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    • v.29 no.1
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    • pp.1-14
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    • 2015
  • Objectives This experimental study was designed to investigate the effects of Dai-saiko-to (DSH) on differentiation of 3T3-L1 preadipocytes and body weight, serum lipid levels in high-fat diet-induced obese mice. Materials and Methods Cells were incubated with DSH at an indicated concentration (0.01-1 mg/ml) for 24h, then the growth rate was assessed by MTS assay. 3T3-L1 preadipocytes were incubated in DMEM for 2 days with the indicated concentrations of DSH. On Day 6, the cells were fixed and the cellular lipid contents were assessed by Oil-Red-O staining. The expression of peroxisome proliferator-activated receptor ${\gamma}$ ($PPAR{\gamma}$) and cytidine-cytidine-adenosine-adenosine-thymine (CCAAT)/enhancer-binding proteins ${\alpha}$ ($C/EBP{\alpha}$) as adipocyte-specific proteins were determined by real time RT-PCR and western blotting. Four-weeks old mice (wild-type C57BL/6) were used for all experiments. Body weight gain and serum lipid levels were measured in the obesity-induced mice. Results DSH did not show toxicity even at the concentration of 1 mg/ml and DSH significantly inhibited the differentiation of 3T3-L1 preadipocytes in a dose-dependent manner. Also, DSH significantly reduced the expressions of $PPAR{\gamma}$ and $C/EBP{\alpha}$ in a dose-dependent manner. Furthermore, DSH significantly reduced body weight gain, serum glucose, total cholesterol and LDL-cholesterol contents in obesity-induced mice. Conclusions These results demonstrated that DSH inhibited 3T3-L1 preadipocyte differentiations and high-fat diet-induced obesity in mice.

Mixed Bacillus sp. BOD sensor (혼합 Bacillus sp. BOD 센서)

  • Kang, Tae Young;Park, Hyun Joo;Park, Kyeong Ryang;Kim, Jin Doo;Cha, Geun Sig;Nam, Hakhyun
    • Analytical Science and Technology
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    • v.20 no.1
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    • pp.1-9
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    • 2007
  • The BOD (biochemical oxygen demand) sensor was fabricated by covering a dissolved oxygen (DO) probe with a microbe-impregnated membrane and a dialysis membrane. Various microorganisms isolated from the soils, water and activated sludge have been evaluated for measuring biochemical oxygen demand (BOD); Bacillus species HN24 and HN93 were selected as they exhibited rapid oxygen consumption and fast recovery. Improved BOD sensor could be prepared by using mixed microbes (Bacillus subtilis, Bacillus sp. HN24 and Bacillus sp. NH93) and silicon rubber gas-permeable membrane for DO probe, and by bubbling 50% $O_2$ ($N_2$ valence) through background buffer solution. This system exhibited excellent analytical performance resulting in good linearity ($r^2=0.9986$) from 0 to 100 mg/L level of BOD.