• Title/Summary/Keyword: MnO2

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Microwave hybrid sintering of NTC themistor (마이크로파 하이브리드 소결법에 의한 NTC 서미스터의 제조)

  • 최영락;안진용;안주삼;백동규;최승철
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.8 no.3
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    • pp.508-512
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    • 1998
  • The NTC thermistors were sintered by using microwave hybrid heating method at $1100^{\circ}C$~$1300^{\circ}C$ and those electrical properties were investigated. The obtained $B_{25^{\circ}C/85^{\circ}C}$ values from temperature dependence of electrical resisitivity were around 3100~3200 K which were almost the same values as conventionally sintered ones. Compared with conventional sintering process, this process could complete whole sintering process within 20 minutes. This the processing time and energy consumption could be reduced through this rapid heating by using microwave hybrid heating.t there were showed only two peaks, glycolide melting peak and lower molecular weight melting peak without lauryl alcohol. Conversion increased slowly with the reaction time up to 50 minutes, and then gave a sudden increase above that. The reaction time to disappear in glycolide melting peak during polymerization was shortened with the increase of lauryl alcohol content. Zero-shear viscosity of polyglycolic acid decreased with the increase of free acid content in glycolide.ssional energy and bending hysteresis increased. \circled3 Surface characteristics such as friction coefficient and thickness variation of highly shrinkage fabrics became relatively roughened state. \circled4 Since stiffened and roughened characteristics of highly shrinkage fabrics, drapabilities of them were significantly lowered. Additionally thermal insulation property of high shrinkage fabric was higher than that of low shrinkage fabric due to bulky and thickened feature. From the results, it is considered that the silk fabrics with high filling shrinkage have the good bulkiness and heat keeping properties and thus they have the suitable characteristics for high quality men's and women's formal garments.

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The Study on the Amount and Major Compositions of Excreta from Swine (돼지의 분뇨 배설량 및 분뇨 성분 조사)

  • HwangBo, Jong;Hong, Eui-Chul;Park, Hee-Du;Kim, Dong-Woon;Cho, Sung-Back
    • Journal of Animal Science and Technology
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    • v.52 no.4
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    • pp.319-328
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    • 2010
  • This work was carried out to investigate the quantity of excreta and its composition in crossbred pigs (Yorkshire ${\times}$ Landrace ${\times}$ Duroc) at different stages of growth. Twelve young piglets (average BW weight of $19.0{\pm}0.33kg$) were used in this study. Pigs were divided into four phases during growing time and two phases during finishing time. The average excreta production for growing pig was 3.46 kg/head/day (feces: 1.07 kg, urine: 2.39 kg). The average moisture contents of feces and urine were 70.54% and 97.39%, respectively. Contents of Calcium, Magnesium, Copper, Plumbum, and Arsenic were 1.00%, 0.26%, 10.47 mg/kg, 2.43 mg/kg, and 1.02 mg/kg, respectively. The concentration of the water pollutants like Biochemical Oxygen Demand ($BOD_5$), Chemical Oxygen Demand (COD), Suspended Solid (SS), Total Nitrogen (TN) and Total Phosphorus (TP), excreted from pig were 96335, 61073, 207466, 8104 and 4209 mg/L in feces and 7364, 7149, 2715, 10110 and 613 mg/L in urine at the end of test, respectively. The daily loading amount of water pollutants ($BOD_5$, COD, SS, TN, and TP, respectively) in pig excreta were 102.1, 61.8, 221.6, 8.7, and 3.9 g/head/day in feces, and 19.3, 16.7, 8.0, 22.2, and 1.3 g/head/day in urine, respectively. The Nitrogen, $P_2O_5$, and $K_2O$ contents in the excreta of pigs were 0.96, 0.83 and 0.42% in feces, and 0.80, 0.09 and 0.53% in urine, respectively. Finally, this work was suggested to give basic information to swine farms.

Occurrence and Geochemical Characteristics of the Haenam Pb-Zn Skarn Deposit (해남 연-아연 스카른광상의 산상과 지화학적 특성)

  • Im, Heonkyung;Shin, Dongbok;Heo, Seonhee
    • Economic and Environmental Geology
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    • v.47 no.4
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    • pp.363-379
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    • 2014
  • The Haenam Pb-Zn skarn deposit is located at the Hwawon peninsula in the southwestern part of the Ogcheon Metamorphic Belt. The deposit is developed along the contact between limestone of the Ogcheon group and Cretaceous quartz porphyry. Petrography of ore samples, chemical composition of skarn and ore minerals, and geochemistry of the related igneous rocks were investigated to understand the characteristics of the skarn mineralization. Skarn zonation consists of garnet${\pm}$pyroxene${\pm}$calcite${\pm}$quartz zone, pyroxene+garnet+quartz${\pm}$calcite zone, calcite+pyroxene${\pm}$garnet zone, quartz+calcite${\pm}$pyroxene zone, and calcite${\pm}$chlorite zone in succession toward carbonate rock. Garnet commonly shows zonal texture comprised of andradite and grossular. Pyroxene varies from Mn-hedenbergite to diopside as away from the intrusive rock. Chalcopyrite occurs as major ore mineral near the intrusive rock, and sphalerite and galena tend to increase as going away. Electron probe microanalyses revealed that FeS contents of sphalerite become decreased from 5.17 mole % for garnet${\pm}$pyroxene${\pm}$calcite${\pm}$quartz zone to 2.93 mole %, and to 0.40 mole % for calcite+pyroxene${\pm}$garnet zone, gradually. Ag and Bi contents also decreased from 0.72 wt.% and 1.62 wt.% to <0.01 wt.% and 0.11 wt.%, respectively. Thus, the Haenam deposit shows systematic variation of species and chemical compositions of ore minerals with skarn zoned texture. The related intrusive rock, quartz porphyry, expresses more differentiated characteristics than Zn-skarn deposit of Meinert(1995), and has relatively high$SiO_2$ concentration of 72.76~75.38 wt.% and shows geochemical features classified as calc-alkaline, peraluminous igneous rock and volcanic arc tectonic setting.

솔잎 (Pinus Densiflora)부탄올 획분이 간장의 활성산소 및 제거효소에 미치는 영향

  • 김현숙;이지혜;최진호;김대익;박수현;백승진;조원기
    • Journal of Nutrition and Health
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    • v.35 no.3
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    • pp.291-295
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    • 2002
  • This study was designed to investigate the effects of a butanol (BuOH) fraction from an extract of pine (Pinus densiflora Sieb et Zucc.) needles, on oxygen radicals and their scavenger enzymes in the liver membranes of rats. Twenty-eight male Sprague-Dawley (SD) rats were divided into four groups over a 45 days study period: the control group on a basic diet, and three experimental groups on three different dietary levels of the butanol fraction, specifically 25 mg (BuOH-25), 50 mg (BuOH-50), and 100 mg (BuOH-100) butanol fraction/kg body weight/day, thereby 0.025%, 0.05%, 0.1% of butanol extract of pine needles was added to basil diet respectively. At the end of the experimental period, body weights and food intakes were not different among the four groups. The results showed that cholesterol accumulation in the mitochondria and microsomes of liver cells was significantly inhibited in the BuOH-50 and BuOH-100 groups: by 11.6% and 20.1% in the mitochondria of the BuOH-50 and BuOH-100 groups, respectively; and by 10.5%, and 13.5% in the microsomes of the BuOH-50 and BuOH-100 groups, respectively, compared with the control group. The levels of hydroxyl radicals (.OH) were significantly) lower in the liver mitochondria of the BuOH-50 and BuOH-100 groups (by 13.3% and 18.5%, respectively), while OH radicals were significantly lower in the microsomes or all three experimental groups (by 15.7% in the BuOH-25 group, 20.0% in the BuOH-50 group, and 20.6% in the BuOH-100group), compared with the control group. Superoxide radical (O$_2$) formation was also significantly inhibited in the liver cytosol of both BuOH-50 and BuOH-100 groups; the levels of these radicals were 8.0% lower for the BuOH-50 group and 11.1% lower for the BuOH-100 group, compared to the control group. Copper/Zinc - superoxide dismutase (Cu/Zn-SOD) activities were significantly increased (by 10.3% and 15.9%, respectively) in the liver cytosols of the BuOH-50 and BuOH-100 groups, but Mn-SOD activities were almost identical in the three RuOH groups, compared with the control group. Glutathione peroxidase (GPx) activities were significantly increased in the three experimental groups (by 9.0% in the BuOH-25 group, 19.4% in the BuOH-50 group, and by 25.6% in the BuOH-100 group), compared with the control group. These results suggest that the butanol extract of pine needles may play an effective role in attenuating oxygen radicals and activating scavenger enzymes; consequently, aging may be very effectively modulated and/or inhibited.

Magnetoresistance Effects of Magnetic Tunnel Junctions with Amorphous CoFeSiB Single and Synthetic Antiferromagnet Free Layers (비정질 CoFeSiB 단일 및 합성형 반강자성 자유층을 갖는 자기터널접합의 자기저항 효과)

  • Hwang, J.Y.;Kim, S.S.;Rhee, J.R.
    • Journal of the Korean Magnetics Society
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    • v.15 no.6
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    • pp.315-319
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    • 2005
  • To obtain low switching field ($H_{SW}$) we introduced amorphous ferromagnetic $Co_{70.5}Fe_{4,5}Si_{15}B_{10}$ single and synthetic antiferromagnet (SAF) free layers in magnetic tunnel junctions (MTJs). The switching characteristics for MTJs with structures $Si/SiO_2/Ta$ 45/Ru 9.5/IrMn 10/CoFe 7/AlOx/CoFeSiB 7 or CoFeSiB (t)/Ru 1.0/CoFeSiB (7-t)/Ru 60 (in nm) were investigated and compared to MTJs with $Co_{75}Fe_{25}$ and $Ni_{80}Fe_{20}$ free layers. CoFeSiB showed a lower saturation magnetization of $560 emu/cm^3$ and a higher anisotropy constant of $2800\;erg/cm^3$ than CoFe and NiFe, respectively. An exchange coupling energy ($J_{ex}$) of $-0.003erg/cm^2$ was observed by inserting a 1.0 nm Ru layer in between CoFeSiB layers. In the CoFeSiB single and SAF free layer MTJs, it was frond that the size dependence of the $H_{SW}$ originated from the lower $J_{ex}$ experimentally and by micromagnetic simulation based on the Landau-Lisfschitz-Gilbert equation. The CoFeSiB SAF structures showed lower $H_{SW}$ than that of NiFe, CoFe and CoFeSiB single structures. The CoFeSiB SAF structures were proved to be beneficial far the switching characteristics such as reducing the coercivity and increasing the sensitivity in micrometer to submicrometer-sized elements.

Reinforcement Mining Method for Anomaly Detection and Misuse Detection using Post-processing and Training Method (이상탐지(Anomaly Detection) 및 오용탐지(Misuse Detection) 분석의 정확도 향상을 위한 개선된 데이터마이닝 방법 연구)

  • Choi Yun-Jeong;Park Seung-Soo
    • Proceedings of the Korean Information Science Society Conference
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    • 2006.06b
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    • pp.238-240
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    • 2006
  • 네트워크상에서 발생하는 다양한 형태의 대량의 데이터를 정확하고 효율적으로 분석하기 위해 설계되고 있는 마이닝 시스템들은 목표지향적으로 훈련데이터들을 어떻게 구축하여 다룰 것인지에 대한 문제보다는 대부분 얼마나 많은 데이터 마이닝 기법을 지원하고 이를 적용할 수 있는지 등의 기법에 초점을 두고 있다. 따라서, 점점 더 에이전트화, 분산화, 자동화 및 은닉화 되는 최근의 보안공격기법을 정확하게 탐지하기 위한 방법은 미흡한 실정이다. 본 연구에서는 유비쿼터스 환경 내에서 발생 가능한 문제 중 복잡하고 지능화된 침입패턴의 탐지를 위해 데이터 마이닝 기법과 결함허용방법을 이용하는 개선된 학습알고리즘과 후처리 방법에 의한 RTPID(Refinement Training and Post-processing for Intrusion Detection)시스템을 제안한다. 본 논문에서의 RTPID 시스템은 active learning과 post-processing을 이용하여, 네트워크 내에서 발생 가능한 침입형태들을 정확하고 효율적으로 다루어 분석하고 있다. 이는 기법에만 초점을 맞춘 기존의 데이터마이닝 분석을 개선하고 있으며, 특히 제안된 분석 프로세스를 진행하는 동안 능동학습방법의 장점을 수용하여 학습효과는 높이며 비용을 감소시킬 수 있는 자가학습방법(self learning)방법의 효과를 기대할 수 있다. 이는 관리자의 개입을 최소화하는 학습방법이면서 동시에 False Positive와 False Negative 의 오류를 매우 효율적으로 개선하는 방법으로 기대된다. 본 논문의 제안방법은 분석도구나 시스템에 의존하지 않기 때문에, 유사한 문제를 안고 있는 여러 분야의 네트웍 환경에 적용될 수 있다.더욱 높은성능을 가짐을 알 수 있다.의 각 노드의 전력이 위험할 때 에러 패킷을 발생하는 기법을 추가하였다. NS-2 시뮬레이터를 이용하여 실험을 한 결과, 제안한 기법이 AOMDV에 비해 경로 탐색 횟수가 최대 36.57% 까지 감소되었음을 알 수 있었다.의 작용보다 더 강력함을 시사하고 있다.TEX>로 최고값을 나타내었으며 그 후 감소하여 담금 10일에는 $1.61{\sim}2.34%$였다. 시험구간에는 KKR, SKR이 비교적 높은 값을 나타내었다. 무기질 함량은 발효기간이 경과할수록 증하였고 Ca는 $2.95{\sim}36.76$, Cu는 $0.01{\sim}0.14$, Fe는 $0.71{\sim}3.23$, K는 $110.89{\sim}517.33$, Mg는 $34.78{\sim}122.40$, Mn은 $0.56{\sim}5.98$, Na는 $0.19{\sim}14.36$, Zn은 $0.90{\sim}5.71ppm$을 나타내었으며, 시험구별로 보면 WNR, BNR구가 Na만 제외한 다른 무기성분 함량이 가장 높았다.O to reduce I/O cost by reusing data already present in the memory of other nodes. Finally, chunking and on-line compression mechanisms are included in both models. We demonstrate that we can obtain significantly high-performanc

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The Study to Re-establish the Amount and Major Compositions of Slurry From Seasonal Swine Farms (슬러리 돈사에서의 슬러리 발생량 및 주요성분 재설정 연구)

  • Kwag, J.H.;Choi, D.Y.;Kim, J.H.;Jeong, K.H.;Park, C.H.;Jeong, M.S.;Han, M.S.;Kang, H.S.;Ra, C.S.
    • Journal of Animal Environmental Science
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    • v.15 no.2
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    • pp.147-154
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    • 2009
  • The purpose of this study was to determine the effect of re-establish the amount and major compositions of slurry from swine farms. The results obtained in this study was summarized as follow; The quantity of wastewater produced from the average volume of pig slurry was $4.64{\ell}$ /head/day and $4.68{\ell}$ in spring, $4.70{\ell}$ in summer, $4.70{\ell}$ in autumn, and $4.49{\ell}$ in winter. The average moisture content of slurry was 95.5%. And the composition of pig slurry contents of N, $P_2O_5$ and $K_2O$, were 0.27, 0.20 and 0.17% in slurry, respectively. The water pollutant concentration in slurry of swine farms, $BOD_5,\;COD_{MN}$, SS, T-N and T-P, was $21,856mg/{\ell},\;33,883mg/{\ell},\;41,253mg/{\ell},\;2,869mg/{\ell}$ and $565mg/{\ell}$, respectively.

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Sulfur Dioxide, Mineral Contents and Physicochemical Properties Generated during Manufacture of Bamboo Salt (죽염 제조공정에 따른 이산화황, 미네랄 함량 및 이화학적 특성)

  • Kim, Hag-Lyeol;Lee, Seong-Jae;Lee, Jung-Hee;Kim, In-Cheol
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.8
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    • pp.1248-1256
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    • 2014
  • The purpose of this study was to investigate the mechanisms of behind $SO_2$ formation and elevated cause of reducing power in purple bamboo salt (PBS) along with an analysis of physicochemical properties, content of sulfur compounds, oxidation reduction potential (ORP), mineral contents of salt type (MSS, mudflat solar salt; BS, bamboo salt), and addition of raw bamboo (RB). $SO_2$ content of 630 ppm was detected in PBS. $SO_2$ was not detected in MSS, BS, or RB, whereas $SO_2$ (782 ppm) from $K_2SO_4$ was detected after heating a NaCl, KCl, $MgCl_2$, $MgSO_4$, MgO, $CaCl_2$, $K_2SO_4$, and $FeSO_4$ with RB. $SO_2$ content of BS increased with baking time, and it originated from BSRB1 (13.88 ppm) to BSRB4 (109.13 ppm). $SO_3{^{2-}}$ originated only from MSSRB4 and BSRB2~BSRB4. Sulfate ion content decreased along with increasing $SO_2$ and sulfite ion contents. ORP increased with baking time of MSS and BS, and it was present at higher levels in BSRB4 (-211.40 mV) of BS than MSS. Insoluble content was higher in BS than MSS. Further, Ca, K, and Mg ion contents decreased in MSS and increased in BS with baking time. BSRB4 had 1.4 fold higher levels of Ca, 1.5 fold higher levels of Mg, and 1.8 fold higher levels of K than BS. Li, Al, Mn, Fe, and Sr in MSS as well as Al, Fe, and Ni in BS increased with baking time. Anions (Cl, $NO_3$, and Br) and heavy metals (Pb, Cd, Hg, and As) between MSS and BS were not significantly different. These results suggest that the reducing power of BS was due to $SO_2$ and sulfite ion. To increase the amounts of these compounds and reducing power, higher melting temperature and longer baking time are necessary along with BS, which is created by the addition of RB to roasted salt.

Estimation of Characteristics and Methane Production Rate of Food Waste (음식물류 폐기물 특성 및 메탄 발생가능량 평가)

  • Lee, Min-Kyu;Kim, Kyung;Shin, Hyun-Gon;Bae, Ki-Hwan;Kim, Choong-Gon;Park, Joon-Seok
    • Clean Technology
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    • v.25 no.3
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    • pp.223-230
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    • 2019
  • This research was performed to evaluate the characteristics of food waste from 5 areas in Gangwon Province, Korea and to predict the $CH_4$ gas production rate. Food wastes were sampled in July and September, 2017. The amount of methane gas generation was evaluated through the biochemical methane potential (BMP) test and a calculation method using chemical composition. Average bulk density and pH of the food wastes were in the range of $0.758{\sim}0.850g\;cm^{-3}$ and 4.29 ~ 4.75, respectively. By physical composition, vegetables were the highest with 56.43 ~ 72.81% with fruits recording 5.31 ~ 8.95%, cereals 1.60 ~ 18.73%, fish and meat 4.47 ~ 12.11%, and filtrate 1.76 ~ 3.64%. The average water content was 69.30 ~ 75.87%, and VS and ash content were 22.50 ~ 27.98% and 1.63 ~ 2.48%, respectively. In addition, $BOD_5$, $COD_{Cr}$, and $COD_{Mn}$ were in the ranges of $17,690.3{\sim}33,154.9mg\;L^{-1}$, $106,212.3{\sim}128,695.5mg\;L^{-1}$, and $51,266.1{\sim}63,426.3mg\;L^{-1}$, respectively. The NaCl content ranged from 0.81 to 1.17%. The results of elemental analysis showed that the contents of C, H, O, N, and S were 44.87 ~ 48.1%, 7.12 ~ 7.57%, 40.13 ~ 43.78%, 3.22 ~ 4.14%, and 0.00 ~ 0.02%, respectively. In a comparison of the methane production yield per VS mass of food waste, there was no significant difference between the cumulative amount (${0.303{\sim}0.354m_{CH4}}^3\;{kg_{VS}}^{-1}$) by the BMP test and the theoretical amount (${0.294{\sim}0.352m_{CH4}}^3\;{kg_{VS}}^{-1}$) calculated by chemical composition.

Effect of Chelating Agents on the Grwoth of Chinese cabbage and Availability of Nutrients in Plastic Film House Soils (시설재배지에서 킬레이트제 처리가 양분 유효도와 배추생육에 미치는 영향)

  • Kim, Myung-Sook;Kim, Yoo-Hak;Roh, Mi-Young;Kang, Seong-Soo;Yoon, Hong-Bae;Lee, Hyeong-Yong
    • Korean Journal of Soil Science and Fertilizer
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    • v.45 no.6
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    • pp.949-954
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    • 2012
  • This study is conducted to evaluate the effects of chelating agents for improving plant growth and reusing accumulated nutrients in soils of plastic film house. Two experiments were carried out at follows: i) The incubation test was conducted using soils treated with 0, 300 mM of EDTA and DTPA to examine the availability of nutrients. ii) For the pot test, chinese cabbages were cultivated in soils with 0, 0.1, 0.5, 1, and 5 mM of EDTA and DTPA to examine the impacts of plant growth response. The application of chelating agents increased ther availability of soil nutrients in the following order: DTPA > EDTA > control. Inorganic concentration of chinese cabbages in DTPA treatments consderably increased in nitrogen, phosphate, iron and aluminium contents than that of the other treatments. The optimal concentration of DTPA for vigorous plant growth as 0.5 mM. Thus, DTPA was more effective than other chelating agents for healty growth of cabbages and the availability of nutrients accumulated in plastic film house.