• Title/Summary/Keyword: 04A25

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Preparation and Electrochemical Performance of Electrode Supported La0.75Sr0.25Ga0.8Mg0.16Fe0.04O3-δ Solid Oxide Fuel Cells

  • Yu, Ji-Haeng;Park, Sang-Woon;Woo, Sang-Kuk
    • Journal of the Korean Ceramic Society
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    • v.48 no.5
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    • pp.479-484
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    • 2011
  • In this paper, investigations of thick film $La_{0.75}Sr_{0.25}Ga_{0.8}Mg_{0.16}Fe_{0.04}O_{3-{\delta}}$ (LSGMF) cells fabricated via spin coating on either NiO-YSZ anode or $La_{0.7}Sr_{0.3}Ga_{0.6}Fe_{0.4}O_3$ (LSGF) cathode substrates are presented. A La-doped $CeO_2$ (LDC) layer is inserted between NiO-YSZ and LSGMF in order to prevent reactions from occurring during co-firing. For the LSGF cathode-supported cell, no interlayer was required because the components of the cathode are the same as those of LSGMF with the exception of Mg. An LSGMF electrolyte slurry was deposited homogeneously on the porous supports via spin coating. The current-voltage characteristics of the anode and cathode supported LSGMF cells at temperatures between $700^{\circ}C$ and $850^{\circ}C$ are described. The LSGF cathode supported cell demonstrates a theoretical OCV and a power density of ~420 mW $cm^2$ at $800^{\circ}C$, whereas the NiO-YSZ anode supported cell with the LDC interlayer demonstrates a maximum power density of ~350 mW $cm^2$ at $800^{\circ}C$, which decreased more rapidly than the cathode supported cell despite the presence of the LDC interlayer. Potential causes of the degradation at temperatures over $700^{\circ}C$ are also discussed.

Characteristics and Applications of Immobilized Glucoamylase (고정화 글루코아밀라제의 성질과 응용)

  • Cho, Sung-Hwan;Kim, Ze-Uook
    • Applied Biological Chemistry
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    • v.28 no.4
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    • pp.233-238
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    • 1985
  • Glucoamylases catalyze a stepwise hydrolysis of starch with the production of glucose. In order to make an efficient conversion of starch into glucose, glucoamylases prepared from Rhizopus spp. (Sigma Co.) were attached to a porous glass and immobilized by glutaraldehyde-induced crosslinking. The porous glass used in this study was $ZrO_2$ coated, $40{\sim}80$ mesh, 550 A pore diameter. Using the forgoing glass, we could couple as much as 50mg of protein per gram of carrier. Substrate for the glucoamylase was an enzyrne-modified thin-toiling 30% cornstarch solution used where greater solubility and low viscosity are desired. Immobilized glucoamylase had an optimum pH 7.0 to the alkaline side of soluble enzyme. Km values of immobilized and soluble enzyme were 1.04 mM and 1.25mM, respectively. The thermal stability of glucoamylase was increased by immobilization and the immobilized enzyme showed an optimum temperature at $40{\sim}60^{\circ}C$. The continuous conversion of cornstarch to glucose by use of immobilized glucoamylase resulted in the production of a more than 90 DE product.

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A New Early Flowering, Spray Chrysanthemum Cultivar for Cut Flower, "Green witch" with Pompon Type and Green Petals (조기개화성의 녹색 폼폰형 절화용 스프레이국화 "그린위치" 육성)

  • Hwang, Ju Chean;Chin, Young Don;Kim, Jin Ki;Kim, Su Kyeong
    • Korean Journal of Breeding Science
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    • v.41 no.4
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    • pp.529-533
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    • 2009
  • A new spray chrysanthemum (Dendranthema grandiflorum) cultivar "Green Witch" was developed from a cross between 'S04161' and 'S04109' by selection of seedlings and lines at the Flower Research Institute, Gyeongnam Agricultural Research and Extension Services (ARES) from 2004 to 2008. Its characteristics were investigated three times from 2006 to 2008 under condition of forcing culture in spring and retarding culture in autumn. The natural flowering time of "Green Witch" was October 19th, and year-round production was possible by day length treatment. Its capitulum was 3.2cm in diameter, and had 15.9 head per stem in autumn. Its ray floret was green central zone. To flower in the short day condition, for "Green Witch" was about 44 days in spring, and "Green Witch" showed the vase life of 25.3 days in autumn. This cultivar was registered for a commercialization in 2008.

Estimation of Axial toad Capacity for Tapered Piles Using Equivalent Transformation (등가변형을 이용한 테이터 말뚝의 지지력 산정)

  • Jun, Sung-Nam;Seo, Kyung-Bum;Song, Won-Jun;Lee, Jun-Hwan
    • Journal of the Korean Geotechnical Society
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    • v.25 no.8
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    • pp.57-64
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    • 2009
  • In this study, a method using equivalent transformation for estimation of the axial load capacity of tapered piles is proposed. While preexistent methods for estimating the axial load capacity of tapered piles have been based on the effect of soil state and taper angle, a new design method is proposed considering cone resistance $q_c$ and equivalent transformation in sand. Through tapered pile simplified by using equivalent transformation, a new method fur quick and easy estimation of the axial load capacity of tapered pile is proposed for practical use. In order to verify the proposed method, calibration chamber test and field test were conducted. In calibration chamber test, comparison of estimated axial load capacity with measured one showed that the standard deviation and COV (Coefficient Of Variation) of estimated $Q_t$ is $0.05{\sim}0.121$, $0.04{\sim}0.05$ respectively. For field test, axial load capacity by proposed method shows 2.5% under-estimation in comparison with measured value. As a result, it is found that proposed method produces satisfactory predictions for tapered piles.

Studies on Biology and Control of the Mulberry Small Weevil, Baris deplanata ROELOFS (Coleoptera: Curculionidae) (뽕나무애바구미의 생태 및 방제에 관한 연구)

  • 백현준;백운하
    • Journal of Sericultural and Entomological Science
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    • v.18 no.2
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    • pp.65-78
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    • 1976
  • The mulberry small weevil, Baris deplanata ROELOFS, has highly infested mulberry trees in Korea. As the damage caused by the mulberry small weevil in mulberry fields has been increased over the country since 1969, the authors has carried out a series of biological and controlling studies on the pest from 1971 to 1972. The results obtained are summarized as follows. 1. The adult weevil is elongate oval in shape with black in color and the probocis is long as usual in curculionidae. The size of adult female is 3.30${\pm}$0.04mm in length, 1.47${\pm}$0.04mm in width, and the length of proboscis is 1.25${\pm}$0.014mm, while adult male is 3.28${\pm}$0.06mm in length, 1.40${\pm}$0.04mm in width, and the length of proboscis is 1.30${\pm}$0.02mm. The antenna is geniculate consisting of 12 segments. The terminal sternite of the abdomen has a pointed tip in male but not in female. 2. The egg is long oval in shape, milky white in color, 0.51${\pm}$0.05mm in length and 0.32${\pm}$0.02mm in width. 3. The mature larva is cylindrical and light yellowow in color except the head of dark brown, and legless, 3.88${\pm}$0.06mm in length, 1.40${\pm}$0.02mm width, each segment bearing many wrinkless and short setae. 4. The pupa is long oval, milky white and exarate, 3.53${\pm}$0.09 in length, 1.40${\pm}$0.03mm in width. 5. Majority of the species has one generation through a year and overwinters as adult in xylem of withered branch and come out again from late April to early May in next year. But some of the female oviposit in the same year and the offsprings overwinter as larva (0.4%) or pupa (0.1%) 6. The eggs are mostly laid under the cork layer of withered branch and the number of eggs deposited by an adult female is 73.44${\pm}$8.74, the average egg-laying period is 33.88${\pm}$6.04 days. The incubation period is 11.69${\pm}$0.39 days, the larval period 45.04${\pm}$1.63 and the pupal period 11.05${\pm}$0.49 days. The period of adult's activity is 46.7${\pm}$5.90 days. 7. The larvae feed on the cambium under the bark and adults feed on the winter bud, the latent bud, the leaf stalk and the base of newly shoot. 8. An active period of adults was observed during the period of 4 months from April to July. However, the peak of adult-density occurred in the early May (in the fields of spring-prunning) and early to middle June(in the fields of summer-prunning). 9. There is a positive correlation between the density of larvae and diameter and length of the branches. 10. The pattern of distributions of the adult of mulberry small weevil is negative binomial distribution. 11. The chalcid fly was disclosed to be a natural enemy which was parasite on the larvae of mulberry small weevil and its parasitic ratio was 11.9%. 12. Phosvel D, Malix D, Salithion EC, DDVP EC, and Phosvel EC were effective for the control of adults and Satchukoto-S EC, and Salithio EC were effective for the control of larvae.

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Design of Ku-band Low Phase Noise Oscillator Using DSRR Structure Resonator based on Metamaterial (메타구조 기반의 DSRR 구조 공진기를 이용한 Ku 대역 저 위상잡음 발진기)

  • Yoon, Nanae;Seo, Chulhun
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.2
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    • pp.19-22
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    • 2014
  • In this paper, Ku-band low phase noise oscillator using DSRR structure resonator based on metamaterial was proposed. To improve the phase noise of the oscillator, the proposed resonator consist of a DSRR strcuture based on metamaterial. The proposed resonator have a characteristic of $S_{11}$ is -0.25 dB, and $S_{21}$ in -44.59 dB at 14.67 GHz, respectively. At 14.67 GHz, the proposed Ku-band low phased oscillator achieves a output power of 2.03 dBm, $2^{nd}$ harmonic of -36.04 dBc, and phase noise of -130.63 dBc at the 100 kHz offset, respectively.

The Crystal and Molecular Structure of N-Acetyl-L-cysteine (N-Acetyl-L-cysteine의 결정 및 분자구조)

  • Young Ja Lee;Il-Hwan Suh
    • Journal of the Korean Chemical Society
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    • v.24 no.3
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    • pp.193-200
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    • 1980
  • The crystal structure of N-acetyl-L-cysteine, $C_5H_9NO_3S,$ has been determined from three dimensional photographic intensity data $(CuK{\alpha}$ radiation) by single crystal X-ray diffraction analysis. There is one formula unit in the triclinic unit cell with a = 7.04(3), b = 5.14(2), c = 8.25(3) ${\AA}$, ${\alpha}$ = 106(2), ${\beta}$ = 51(1), ${\gamma}$ = 124(2)$^{\circ}$ and space group P$_1$, The structure was solved by the direct method and refined by the full matrix least-squares method. The final R value is 12.3% for 629 observed reflections. The C-carboxyl group and the N-acetyl group are very neary planar. The molecule appears to form with neighboring molecules a hydrogen bond, $O-H{\cdot}{\cdot}{\cdot}O(3)$ of length 2.59${\AA}$.

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A Reconfigurable Multiband FMCW Radar for Multipurpose Application (다목적활용을 위한 재구성이 가능한 다중대역 FMCW 레이다)

  • Kim, Byungjoon;Koo, Jong-seop;Kim, Duksoo;Nam, Sangwook
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.26 no.12
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    • pp.1112-1115
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    • 2015
  • Recently, there have been advancements in radar related material technology, circuit design techniques and architecture design techniques. These have led to developments in radars' performance while decreasing the costs. Many studies have been carried out to apply radars to multipurpose application. In this study, a reconfigurable S-/X- band radar structure for multipurpose application is proposed and implemented. This radar measures a $51.2cm{\times}50.6cm$ target for 10 times from 2 m to 6 m range with 0.25 m distance step. The measured results show that this radar has 26.40 cm maximum range error, 5.63 cm average range error, and 0.24 cm range error variance at S-band while it has 8.53 cm maximum range error, 2.52 cm average range error, and 0.04 cm range error variance at X-band.

An Updated Meta-analysis on the Association of X-Ray Repair Cross Complementing Group 1 Codon 399 Polymorphism with Hepatocellular Carcinoma Risk

  • Wang, Ya-Dong;Zhai, Wen-Long;Wang, Hai-Yu;Xia, Xiang-Qun
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.11
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    • pp.4443-4448
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    • 2014
  • Background: A number of studies have reported the association of X-ray repair cross-complementing group 1 (XRCC1) Arg399Gln polymorphism with susceptibility to hepatocellular carcinoma (HCC). However, the results were inconsistent and inconclusive. The aim of this study was to comprehensively explore the association of XRCC1 Arg399Gln variant with HCC risk. Materials and Methods: Systematic searches of PubMed, Elsevier, Science Direct, CNKI and Chinese Biomedical Literature Database were performed. Pooled odds ratio (OR) with 95% confidence intervals (CI) was calculated to estimate the strength of association. Results: Overall, we observed an increased HCC risk among subjects carrying XRCC1 codon 399 Gln/Gln, Arg/Gln and Gln/Gln+Arg/Gln genotypes (OR=1.20, 95%CI: 1.05-1.38, OR=1.16, 95%CI: 1.05-1.28, and OR=1.14, 95%CI: 1.04-1.24, respectively) based on 20 studies including 3374 cases and 4633 controls. In subgroup analysis, we observed an increased risk of XRCC1 codon 399 Gln/Gln, Arg/Gln and Gln/Gln+Arg/Gln polymorphisms for HCC in hospital-based study (OR=1.25, 95%CI: 1.03-1.51, OR=1.21, 95%CI: 1.07-1.36 and OR=1.18, 95%CI: 1.06-1.31, respectively) and in Asian population (OR=1.19, 95%CI: 1.03-1.38, OR=1.17, 95%CI: 1.04-1.30 and OR=1.14, 95%CI: 1.04-1.25, respectively). Limiting the analysis to the studies with controls in agreement with Hardy-Weinberg equilibrium (HWE), we observed an increased HCC risk among Gln/Gln, Arg/Gln and Gln/ Gln+Arg/Gln genotype carriers (OR=1.17, 95%CI: 1.05-1.29, OR=1.12, 95%CI: 1.00-1.25 and OR=1.11, 95%CI: 1.02-1.21, respectively). Conclusions: This updated meta-analysis results suggest that XRCC1 Arg399Gln variants may contribute to HCC risk. Well-designed studies with larger sample size were required to further verify our findings.

Mineral Contents in Bottled Natural Water and Estimation of Their Intake by Korean Adults (일부 무기질의 생수 중 함량 분석과 생수를 통한 섭취량 평가)

  • Kim, Moo-Kyung;Sim, Jin-Ah;Eom, Hee-Jung;Kim, Myung-Hee;Choi, Mi-Kyeong
    • Journal of the Korean Dietetic Association
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    • v.16 no.2
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    • pp.116-121
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    • 2010
  • Minerals play an important role in the body as essential nutrients. However, it is not easy to meet DRIs because food sources of minerals are limited. Recently, consumption of bottled natural water has been increasing in Korea due to water pollution and distrust of tap water. The present study was conducted to investigate mineral contents in bottled natural water and their intakes among Korean adults. We analyzed eight minerals in seven kinds of bottled natural water by ICP-spectrometry and conducted a survey on the intake status of water and bottled natural water with 400 Korean young adults. The mean contents of Ca, Mg, Fe, Zn, Cu, Mn, Se, and Mo in bottled natural water were 22.45${\pm}$22.48 mg/L, 10.59${\pm}$9.97 mg/L, 0.27${\pm}$0.18 ${\mu}g/L$, 2.06${\pm}$1.48 ${\mu}g/L$, 5.47${\pm}$0.70 ${\mu}g/L$, 1.43${\pm}$0.37 ${\mu}g/L$, 1.90${\pm}$0.96 ${\mu}g/L$, and 3.34${\pm}$0.79 ${\mu}g/L$, respectively. The mean age, height, weight, and BMI were 22.76 years, 174.94 cm, 68.64 kg, and 22.41 $kg/m^2$ for males (n=150) and 21.25 years, 162.04 cm, 51.05 kg, and 19.46 $kg/m^2$ for females (n=250), respectively. The respective daily intakes of total water and bottled natural water as water itself were 670.30 ml and 212.20 ml for males and 488.04 ml and 132.72 ml for females. The daily intakes of Ca, Mg, Fe, Zn, Cu, Mn, Se, and Mo from bottled natural water were 4.76 mg, 2.25 mg, 0.06 ${\mu}g$, 0.44 ${\mu}g$, 1.16 ${\mu}g$, 0.30 ${\mu}g$, 0.40 ${\mu}g$, and 0.71 ${\mu}g$ for males and 2.98 ${\mu}g$, 1.41 mg, 0.04 ${\mu}g$, 0.27 ${\mu}g$,0.73 ${\mu}g$, 0.19 ${\mu}g$,0.25 ${\mu}g$, and 0.44 ${\mu}g$ for females, respectively. Overall, the contents of Ca, Mg, and Se in bottled natural water were relatively high and the daily intakes of these minerals were 0.4~1.0% of the DRIs.