• Journal of Nutrition and Health
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• v.46 no.4
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• pp.315-323
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• 2013

This study was conducted in order to compare the biological activities of leaf and root water extracts of Smilax china L. (SC) by measuring the total polyphenol and flavonoid contents, anti-oxidant activity, inhibitory effect on ${\alpha}$-glucosidase, and anti-inflammatory gene expression. The total polyphenol and flavonoid contents of SC leaf (SCLE) and root (SCRE) water extracts were 127.93 mg GAE/g and 39.50 mg GAE/g and 41.99 mg QE/g and 1.25 mg QE/g, respectively. The anti-oxidative activities of SCLE and SCRE were measured using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity assay and reducing power assay. Both SCLE and SCRE scavenged radicals in a concentration-dependent manner, and SCLE showed stronger radical scavenging activity and reducing power than SCRE; however, both SCLE and SCRE exhibited lower activities than ascorbic acid. Compared to the anti-diabetic drug acarbose, which was used as a positive control, SCLE and SCRE exhibited low ${\alpha}$-glucosidase inhibition activities; nevertheless, the activity of SCLE was 3.7 fold higher than that of SCRE. Finally, SCLE caused significantly decreased expression of the LPS-induced cytokines, iNOS, and COX-2 mRNA in RAW264.7 cells, indicating anti-inflammatory activity. These results indicate that SCLE might be a potential candidate as an anti-oxidant, anti-diabetic, and anti-inflammatory agent.

• Journal of Sensor Science and Technology
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• v.7 no.1
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• pp.67-72
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• 1998

The crystallized CuPc and PbTe films are formed by thermal evaporation and pulsed ArF excimer laser ablation. Structural and electrical properties of thin film is observed by XRD and current-voltage(I-V) curves. From XRD analysis, both PbTe and CuPc thin films show a-axis oriented structure. For the measurement of photovoltaic effect, the transverse current-voltage curve of CuPc/Si, PbTe/Si and PbTe/CuPc/Si junctions have been analyzed in the dark and under illumination. The PbTe/CuPc/Si junction exthibits a strong photovoltaic characteristics with short circuit current($J_{sc}$) of $25.46\;mA/cm^{2}$ and open-circuit voltage($V_{oc}$) of 170 mV. Quantum efficiency and power conversion efficiency are calculated to be 15.4% and $3.46{\times}10^{-2}$, respectively. Based on the results of QE and ${\eta}$, the photocurrent process of PbTe/CuPc/Si junction can be explained as following three effective steps; photocarrier generation in the CuPc layer, carrier separation at PbTe/CuPc interface, and finally a transportation of electrons through the PbTe layer.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.63.2-63.2
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• 2010

삼중접합 태양전지에 상부전지로 이용되는 a-SiO:H 태양전지는 PECVD(Plasma Enhanced Chemical Vapour Deposition)을 이용하여 증착하였다. i a-SiO:H는 $CO_2/SiH_4$ 비율을 변화하여 밴드갭을 조절하였다. $CO_2/SiH_4$가 0에서 0.43으로 증가 할수록 밴드갭이 1.74 eV에서 1.94 eV로 증가하는 경향을 보였다. 이는 FTIR에서 나타난 결과인 Si-O-Si 결합의 증가 때문인 것으로 판단한다. 그에 반해서 광 전도도는 감소하는 경향을 보였다.그러나 암전도도와 광전도도의 비율인 광민감도는 $10^5$에서 $10^4$의 값으로 비정질 태양전지에 적용가능한 값을 보였다. 이러한 박막 특성을 가진 i a-SiO:H를 이용하여 비정질 실리콘 태양전지를 제작한 결과 $CO_2/SiH_4$의 비율이 증가함에 따라 태양전지의 $V_{oc}$가 0.8 V에서 0.5 V로 현저하게 감소하였고, $J_{sc}$와 FF 역시 11 $mA/cm^2$에서 4 $mA/cm^2$, 69%에서 50%로 감소하였다. 단위박막 결함을 측정하는 CPM(Constant Photocurrent Method)을 이용하여 i a-SiO:H 내부에 $10^{16}cm^{-3}$ 정도의 내부 결함을 관찰하였고 이는 태양전지의 특성 감소와 관련이 있는 것으로 판단한다.

• Journal of Ginseng Research
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• v.42 no.2
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• pp.175-182
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• 2018

Background: The impact of fungicide azoxystrobin, applied as foliar spray, on the physiological and biochemical indices and ginsenoside contents of ginseng was studied in ginseng (Panax ginseng Mey. cv. "Ermaya") under natural environmental conditions. Different concentrations of 25% azoxystrobin SC (150 g a.i./ha and 225 g a.i./ha) on ginseng plants were sprayed three times, and the changes in physiological and biochemical indices and ginsenoside contents of ginseng leaves were tested. Methods: Physiological and biochemical indices were measured using a spectrophotometer (Shimadzu UV-2450). Every index was determined three times per replication. Extracts of ginsenosides were analyzed by HPLC (Shimadzu LC20-AB) utilizing a GL-Wondasil $C_{18}$ column. Results: Chlorophyll and soluble protein contents were significantly (p = 0.05) increased compared with the control by the application of azoxystrobin. Additionally, activities of superoxide dismutase, catalase, ascorbate peroxidase, peroxidase, and ginsenoside contents in azoxystrobin-treated plants were improved, and malondialdehyde content and $O_2^-$ contents were reduced effectively. Azoxystrobin treatments to ginseng plants at all growth stages suggested that the azoxystrobin-induced delay of senescence was due to an enhanced antioxidant enzyme activity protecting the plants from harmful active oxygen species. When the dose of azoxystrobin was 225 g a.i./ha, the effect was more significant. Conclusion: This work suggested that azoxystrobin played a role in delaying senescence by changing physiological and biochemical indices and improving ginsenoside contents in ginseng leaves.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1277-1279
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• 1994

In the structure of ZnO/nip-SiC: H/metal substrate amorphous silicon (a-Si:H) solar cells, the effects of inserting a rear textured ZnO in the p-SiC:H/metal interface and a graded bandgap buffer layer in the i/p-SiC:H have been analysed by computer simulation. The incident light was taken to have an intensity of $100mW/cm^2$(AM-1). The thickness of the a-Si:H n, ${\delta}$-doped a-SiC:H p, and buffer layers was assumed to be $200{\AA},\;66{\AA}$, and $80{\AA}$, respectively. The scattering coefficients of the front and back ZnO were taken to be 0.2 and 0.7, respectively. Inserting the rear buffer layer significantly increases the open circuit voltage($V_{oc}$) due to reduction of the i/p interface recombination rate. The use of textured ZnO markedly improves collection efficiency in the long wavelengths( above ${\sim}550nm$ ) by back scattering and light confinement effects, resulting in dramatic enhancement of the short circuit current density($J_{sc}$). By using the rear buffer and textured ZnO, the i-layer thickness of the ceil for obtaining the maximum efficiency becomes thinner(${\sim}2500{\AA}$). From these results, it is concluded that the use of textured ZnO and buffer layer at the backside of the ceil is very effective for enhancing the conversion efficiency and reducing the degradation of a-Si:H pin-type solar cells.

• Microbiology and Biotechnology Letters
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• v.19 no.5
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• pp.433-438
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• 1991

The plasmid pSY130-14 for the high production of phenylalanine is a temperaturecontrollable expression vector composed of the $P_R$ and the $P_L$ promoter and a temperature sensitive repressor, $cI_{857}$ of bacteriophage lambda. Strain AT2471 harbouring plasmid pSY13O- 14 is induced the phenylalanine production by shifting up the incubation temperaure to $38.5^{\circ}C$. Plasmid stability of E. coli AT2471 harbouring pSY130-14 was very low, it was about 30% after 48 h cultivation at $38.5^{\circ}C$ without kanamycin. The plasmid disappeared immediately at $40^{\circ}C$ without kanamycin, and at $40^{\circ}C$ adding kanamycin, the plasmid stability decreased at the beginning, but rose with the extension of the culture time. For the improvement of plasmid stability, the plasmid obtaind was designated as pSY15O-1 by changing origin region (ori) pACYC 177 of pSY130-14 for ori pSC101. E. coli AT2471 harbouring pSY150-1 was stable at $38.5^{\circ}C$ without tetracycline, and the plasrnid stability was about 40% after 48 h cultivation at $40^{\circ}C$.

• The Journal of the Petrological Society of Korea
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• v.26 no.3
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• pp.271-280
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• 2017

The Dongcheondong granite is alkali feldspar granite in Dongcheondong, Gyeongju. The granite is coarse grained and consists of alkali feldspar, quartz, amphibole, and biotite. Alkali feldspar is perthitic orthoclase and quartz often shows undulatory extinction. Plagioclase often shows albite twins, and biotite and amphibole emplace as interstitial minerals. The Dongcheondong granite is plotted in A-type area having high ($Na_2O+K_2O)/Al_2O_3$ and low (MgO+CaO)/FeOT ratio. The Dongcheondong A-type granite has higher $SiO_2$, $Na_2O$, $K_2O$, Zr, Y, and REE contents (except for Eu) and lower $TiO_2$, $Al_2O_3$, CaO, MgO, Sr, Ba, and Eu contents than I-type granites in Gyeongsang Basin. These results show that the geochemical characteristics of the Dongcheondong A-type granite are distinguished from I-type granite in Gyeongsang Basin. A-type granite in the Dongcheondong is thought to has been generated by partial melting of I-type tonalite or granodiorite.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.2
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• pp.26-36
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• 2008

Due to the differential and low voltage swing, Low Voltage Differential Signaling(LVDS) has been widely used for high speed data transmission with low power consumption. This paper proposes new LVDS I/O interface circuits for more than 1.3 Gb/s operation. The LVDS receiver proposed in this paper utilizes a sense amp for the pre-amp instead of a conventional differential pre-amp. The proposed LVDS allows more than 1.3 Gb/s transmission speed with significantly reduced driver output voltage. Also, in order to further improve the power consumption and noise performance, this paper introduces an inductance impedance matching technique which can eliminate the termination resistor. A new form of unfolded impedance matching method has been developed to accomplish the impedance matching for LVDS receivers with a sense amplifier as well as with a differential amplifier. The proposed LVDS I/O circuits have been extensively simulated using HSPICE based on 0.35um TSMC CMOS technology. The simulation results show improved power gain and transmission rate by ${\sim}12%$ and ${\sim}18%$, respectively.

• Journal of The Korean Association For Science Education
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• v.37 no.2
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• pp.273-290
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• 2017

The purposes of this study are to develop a measuring instrument for perception of science classes based on the view of 'Community of Inquiry in Science Classroom' and to investigate elementary school students' perceptions with the instrument developed in the study. A total of 417 6th grade students participated in this study. As a result, first, we developed two set of questionnaire: (a) the questionnaire for the 'process of inquiry' consisted of six factors: 'problem recognition I: recognition of inconsistency,' 'problem recognition II: interests,' 'problem explanation I: hypothesis generation and examination,' 'problem explanation II: cooperative review,' 'problem solving I: reflection on the change of relationship with objects/conceptions,' and 'problem solving II: reflection on the change of relationship with community/ inquirer,' comprising a total of 42 items; (b) the questionnaire for the 'basis of inquiry' consisted of three factors:'will of conducting inquiry,' 'attitudes of conducting inquiry,' and 'structure of communication,' comprising a total of 17 items. Second, we found that elementary school students had positive recognition generally on their science classes in terms of the 'community of inquiry in science classroom,' but they had relatively negative recognition on the factors of problem recognition based on recognition of inconsistency, problem solving accompanied with reflection on the change of relationship with objects/conceptions, and attitudes of conducting inquiry based on severity and fallibilism, Finally, several suggestions for the science education were given.

• Korean Journal of Weed Science
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• v.15 no.2
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• pp.99-104
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• 1995

This experiment was conducted to evaluate effective weed control in direct-seeded rice under dry fields. The results obtained are as follows. Cyhalofop/bentazone EW and cyhalofop/pendimethalin EC were very effective for the weed control but cyhalofop/cinosulfuron WP and cyhalofop/azimsulfuron SC were tended to exhibit the lower weeding effect. The plant height and the tiller number of rice were not greatly affected by herbicides, but rice yield was greatly influenced by them. The control efficacy was observed the extend of 94% until 60days after seeding under the treatment of systematic herbicides such as foliar applied pendimethalin propanil EC at 15days after seeding mowed by pyrazosulfuron molinate GR at 5days after irrigation. Irrigation at 25days after seeding was able to control annual weeds by the extent of 25% and exhibited control effect of 94% on systematic treatment of herbicides compared with that of 35days after seeding.