• Title/Summary/Keyword: PoW

Search Result 219, Processing Time 0.023 seconds

Growth and Cultural Characteristics of Ophiocordyceps longissima Collected in Korea

  • Sung, Gi-Ho;Shrestha, Bhushan;Han, Sang-Kuk;Sung, Jae-Mo
    • Mycobiology
    • /
    • v.39 no.2
    • /
    • pp.85-91
    • /
    • 2011
  • We investigated the effect of nutritional and environmental factors on Ophiocordyceps longissima mycelial growth. The longest colony diameter was observed on Schizophyllum (mushroom) genetics complete medium plus yeast extract, Schizophyllum (mushroom) genetics minimal medium, and Sabouraud dextrose agar (SDA); however, malt-extract yeast-extract agar, SDA plus yeast extract, yeast-extract malt-extract peptone dextrose agar, SDA, oatmeal agar, and potato dextrose agar showed higher mycelia density. A temperature of $25^{\circ}C$ was optimum and 7.0 was the optimum pH for mycelial growth. Colony diameter was similar under light and dark conditions. Maltose and yeast extract showed the highest mycelial growth among carbon and nitrogen sources respectively. The effect of mineral salts was less obvious; however, $K_3PO_4$ showed slightly better growth than that of the other mineral salts tested. Among all nutrition sources tested, complex organic nitrogen sources such as yeast extract, peptone, and tryptone were best for mycelial growth of O. longissima. Ophiocordyceps longissima composite medium, formulated by adding maltose (2% w/v), yeast extract (1% w/v), and $K_3PO_4$ (0.05% w/v) resulted in slightly longer colony diameter. In vitro mycelial O. longissima growth was sustainable and the production of fruiting bodies could be used for commercial purposes in the future.

Studies on the Chemical Components and Biological Activities of Edible Plants in Korea (II) - Isolation and Quantitative Analysis of Flavonoids from the Leaves of Cedrela sinensis A. Juss. by HPLC - (한국산 식용식물의 화학성분 및 생리활성에 관한 연구 (II) - HPLC에 의한 참죽나무 잎중 Flavonoid 성분의 확인 및 정량 -)

  • 박종철;전순실;양한석;김성환
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.22 no.5
    • /
    • pp.581-585
    • /
    • 1993
  • Five flavonoids isolated from the ethyl acetate fraction of Cedrela sinensis A. Juss. were identified by high performance liquid chromatography. Separation was achieved by reversed phase chromatography on ${\mu}-bondapak$ C18 column with isocratic elution method. The content of the major flavonoid, quercitrin was about 9.48%(w/w) and 37.06%(w/w) for the methanol extract and ethyl acetate fraction, respectively.

  • PDF

Development of Metallic Bipolar Plate Material with W-addition in Austenitic Stainless Steel for PEMFC Environment

  • Kim, Kwang Min;Koh, Sung Ung;Kim, Kyoo Young
    • Corrosion Science and Technology
    • /
    • v.5 no.5
    • /
    • pp.153-159
    • /
    • 2006
  • Austenitic stainless steels with addition of various amounts of Mo and W were evaluated in terms of corrosion and contact resistance to determine optimum alloy composition of metallic bipolar plate for PEMFC. The corrosion property was evaluated by both acid fume exposure test at $130^{\circ}C$ and by electrochemical polarization tests in $H_3PO_4$ solution at $80^{\circ}C$. Austenitic stainless steel with proper amount of Mo and W demonstrated not only good corrosion resistance but also low contact resistance. Analyses on the passive film show that partial substitution of Mo by W enhances passive film stability and repassivation property. Test results suggest that austenitic stainless steel with 2 wt%Mo and 4 wt%W has optimum composition for metallic bipolar plate used in PEMFC.

Design of a Cavity Type M/W Light Modulator by the Pockel's Effect (공동공진형 마이크로파 광 변조기의 설계)

  • 강형목;김정기
    • 전기의세계
    • /
    • v.19 no.6
    • /
    • pp.8-12
    • /
    • 1970
  • A Device is described which intensity modulates a light beam at modulating frequency in the M/W region. A Method of designing a practical crystalline microwave-Freg. light modulator has been described. In addition, Electrooptic properties and operation as light modulator of NH$_{4}$H$_{2}$po$_{4}$ is described. A light path is provided through the crystal into a suitably oriented analyzer. The intensity of the light beam emerging from the latter varies at the same rate as the cavity frequency.

  • PDF

Emission characteristics of volatile organic compounds released from spray products (생활 스프레이 제품의 안전성 조사: 벤젠과 톨루엔 함량을 중심으로)

  • Jo, Hyo-Jae;Kim, Bo-Won;Kim, Yong-Hyun;Lee, Min-Hee;Jo, Sang-Hee;Kim, Ki-Hyun;Kim, Joon-Young;Park, Jun-Ho;Oh, Soo-Min;Lee, Seung-Hwan;Kim, Dong-Yeon
    • Analytical Science and Technology
    • /
    • v.26 no.4
    • /
    • pp.268-275
    • /
    • 2013
  • Many kinds of liquid spray products are used in livelihood activities these days. Spray products can be distinguished by the target to be sprayed (like into the air or on human skin (body)). Because human can be exposed to volatile organic compounds (VOC) emitted from spray products, some considerations on safety or hazard of spray products should be needed. In this study, emission characteristics of VOCs were investigated against 10 types of liquid spray products (6 skin spray and 4 air spray products). The concentrations of benzene and toluene were determined by gas chromatography/mass spectrometry (GC/MS) equipped with a thermal desorber (TD). Their average concentrations from 6 skin spray products exhibited$ 5.64{\pm}1.95$ ($mean{\pm}S.D$) and $8.52{\pm}2.89$ ppb(w), respectively. In contrast, those of 4 air spray samples had $7.30{\pm}1.31$ and $7.19{\pm}1.78$ ppb(w), respectively. If liquid contents in spray samples are completely vaporized in one cubic meter (1 m3) after spraying for 10 seconds, their mean concentrations of skin spray products are $31.7{\pm}8.80$ (benzene) and $50.5{\pm}17.1{\mu}g/Sm^3$ (toluene). In contrast, those of air spray products are $24.0{\pm}4.30$ (benzene) and $23.6{\pm}5.83{\mu}g/Sm^3$ (toluene). The estimated concentration levels of benzene from two types of products (31.7 and $24.0{\mu}/Sm^3$) exceeded the Korean atmospheric environmental guideline ($5{\mu}g/Sm^3$). The results of this study thus suggest that some measures should be made to reduce or suppress the contents of VOC in spray products.

Studies on the production of liquid spawn of Pleurotus ostreatus (Pleurotus ostreatus의 액체 종균 생산에 관한 연구)

  • Kang, Tae-Su;Chun, Byong-IK
    • Journal of Industrial Technology
    • /
    • v.8
    • /
    • pp.13-21
    • /
    • 1988
  • For the improvement of productivity of Pleurotus ostreatus, the production of liquid spawn was studied. The highest liquid spawn production was obtained after shaking culture for 4 days in the culture medium containing 5%(W/V) wheat flour, 0.2%(W/V) yeast extract, 0.1%(W/V)$KNO_3$ 0.05% (W/V) $MgSO_4{\cdot}7H_2O$, 0.05%(W/V) $KH_2PO_4$. The optimum pH and temperature was 7.0 ana $30^{\circ}C$. The period required to complete the mycelial growth after spawning were 28, 22, 10 and 9 days, respectively, when the 2%(V/V) of solid spawn and 2%(V/V), 5% (V/V) and 10%(V/V) of liquid spawn were inoculated. The days required from spawning to fruiting bodies were 38, 34, 28 and 27 days.

  • PDF

Effect of Different Dietary Fats on Colonic Epithelial Cell Phospholipid and Phosphatidyl Inositol Composition in DMH-treated Rats (서로 다른 종류의 식이지방이 1,2-Dimethylhydrazine으로 처리한 쥐의 대장점막 인지질 및 Phosphatidyl Inolsitol의 지방산조성에 미치는 영향)

  • 김채종;남정혜
    • The Korean Journal of Food And Nutrition
    • /
    • v.9 no.1
    • /
    • pp.59-68
    • /
    • 1996
  • The study was designed to observe the effects of different dietary fat consumed in Korea with those of three other fats on colonic epithelial cell phospholipid and phosphatidyl inositol composition, which were known as biomarker for colon cancer. Male Sprague Dawley rats, at 7 weeks of age, were divided into control and 1,2-dimethylhydrazine (DMH) -treated group that was again subdivided into four groups. The experimental diets contained one of four dietary fats at 15%(w/w) level, those were, blend fat(BF), beef tallow(BT), corn oil (CO) or perilla oil (PO) At the same time, each rat was injected nth saline for control group or DMH twice a week for 6 weeks to five total dose of 180 mg/kg body weight. Dietary fatty acid composition influenced the fatty acid compositions of tissues. Proportions of C18:2 colonic mucosal phospholipid well reflected dietary level of C18:2 showing in decending CO>BF>PO> BT. The percentage of C20:4 in phospholipid was the higher in CO and BT groups and the lowest in PO groups. Incorporation of -linolenic acid in colonic mucosal lipid In perilla oil group was negatively correlated to the content of C20:4. Therefore, $\omega$3-linolenic acid rich in perilla oil could be a very important dietary source in controlling arachidonic acid level in colon epithelial cell. Therefore it could be recommend to use more perilla oil in meal preparation to reduce the risk factor against colon cancer.

  • PDF

Performance Analysis of Consensus Algorithm considering NFT Transaction Stability (NFT 거래 안정성을 고려한 합의알고리즘 성능분석)

  • Min, Youn-A;Lim, Dong-Kyun
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.22 no.2
    • /
    • pp.151-157
    • /
    • 2022
  • In this paper, the performance of various blockchain consensus algorithms was compared and analyzed as a method to increase the transaction cost and processing time during NFT transactions and to increase the transaction stability requirements that occur during smart contract execution. Network reliability and TPS are evaluation items for performance comparison. TPS and the stability of the Consensus algorithm are presented for three evaluation items. In order to establish a standardized expression for each evaluation item, the reliability of the node and the success rate of the smart contract were considered as variables in the calculation formula, and the performance of the consensus algorithm of the three groups, PoW/PoS, Paxos/Raft and PBFT, was compared under the same conditions. / analyzed. As a result of the performance evaluation, the network reliability of the three groups was similar, and in the case of the remaining two evaluation items, it was analyzed that the PBFT consensus algorithm was superior to other consensus algorithms. Through the performance evaluation equations and results of this study, it was analyzed that when the PBFT consensus processing process is reflected in the consensus process, the network reliability can be guaranteed and the stability and economic efficiency of the consensus algorithm can be increased.

Studies on the Genetic Relationships of Sheep Populations from East and South of Central Asia

  • Sun, W.;Chang, H.;Yang, Z.P.;Geng, R.Q.;Lu, S.X.;Chang, G.B.;Xu, W.;Wang, H.Y.;Ren, Z.J.;Tsunoda, K.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.15 no.10
    • /
    • pp.1398-1402
    • /
    • 2002
  • Hu sheep was sampled randomly from Huzhou city, Zhejiang province, China. Of the 11 genetic markers from the blood examined by starch-gel and cellulose acetate electrophoresis, polymorphisms in Hu sheep were found for 10 loci, i.e. post-albumin (Po), transferring (Tf), alkaline phosphatase (Alp), leucine aminopeptidase (Lap), arylesterase (Ary-Es), hemoglobin-$\beta$ (Hb-$\beta$)、Xprotein(X-p), carbonic anhydrase (CA), catalase (Cat) and lysine (Ly). The same data except for Po locus were collected from another 14 sheep breeds from China and other countries, in order to ascertain their genetic relationships with one another and with the Hu sheep. The sheep populations from the east and south of Central Asia can be classified into three genetic groups: 'Mongolian sheep', 'South Asian sheep' and 'European sheep'. The Hu sheep belong to the 'Mongolian sheep' group.

Comparative Analysis of Blockchain Systems According to Validator Set Formation Method (검증자 집합 형성 방법에 따른 블록체인 시스템 비교 분석)

  • Kim, Sam-Taek
    • Journal of the Korea Convergence Society
    • /
    • v.10 no.11
    • /
    • pp.41-46
    • /
    • 2019
  • Recently, the Byzantine Fault Tolerance(BFT) family of consensus algorithms has been attracting attention as the problems of the Proof-of-work (PoW) blockchain consensus algorithms result in energy waste and lack of scalability. One of the great features of the PBFT family consensus algorithms is the formation of a set of validators and consensus within them. In this paper, we compared and analyzed the scalability, targeted attackability, and civil attackability of Algorand, Stellar, and EOS validator set formation methods among BFT family consensus algorithms. Also, we found the problems of each verifier formation method through data analysis, and the consensus algorithms showed that the centralization phenomenon that the few powerful nodes dominate the whole system in common.