• Title/Summary/Keyword: $F_0$ value

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콘 관입저항치를 이용한 수직배수재 타설심도 결정에 관한 연구 (A Study on the Determination of Construction Depth of Vertical Drain by Cone Resistance)

  • 김연정;김남호;신윤섭
    • 기술발표회
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    • 통권2006호
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    • pp.261-269
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    • 2006
  • 최근 피조콘시험은 과거 일반적으로 사용되었던 표준관입시험과 함께 연약지반의 특성을 평가하기 위해 빈번히 사용되고 있다. 본 연구에서는 하부지반의 지층상태를 파악하고 설계를 위한 연약지반 심도 결정 및 시공시 수직배수재 타설심도 결정시 그 신뢰도를 향상시키기 위해서 표준관입시험결과(N치), 선행압밀하중(pc), 수직배수재 타설시 관입에너지와 피조콘시험을 통한 콘 관입저항치($q_c$)와의 관계를 분석하였다. 대상 지역별로 일정한 표준관입저항치를 기준으로 평균 연약지반심도를 결정하여, 동일한 심도에서 피조콘관입저항치를 값을 분석한 결과 $q_c$=(1.09~1.63)N, 선행압밀하중을 고려한 결과 $q_c$=(1.21~1.98)N의 관계를 나타내었다. 또한 수직배수재 타설시 관입에너지와 피조콘시험을 통한 콘 관입저항치($q_c$)와의 관계를 분석한 결과 평균적으로 피조콘 관입저항치 10kgf/$cm^2$의 경우 수직배수재 타설 시 관입저항치는 약 65~70.0kgf/$cm^2$의 값을 나타내였다.

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내열강 용접부의 크리프 평가 신기술 개발에 관한 연구(I) (A Study on New Technique Development for Creep Evaluation of Heat Resistant Steel Weldment (I))

  • 유효선;백승세;권일현;이송인
    • Journal of Welding and Joining
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    • 제20권6호
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    • pp.754-761
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    • 2002
  • It has been reported that the creep characteristics on weldment which is composed of weld metal(W.M), fusion line(F.L), heat-affected zone(HAZ), and base meta(B.M) could be unpredictably changed in severe service conditions such as high temperature and high pressure. However, the studies done on creep damage in power plant components have been mostly conducted on B.M and not the creep properties of the localized microstructures in weldment have been thoroughly investigated yet. In this paper, it is investigated the creep characteristics for three microstructures like coarse-grain HAZ(CGHAZ), W.M, and B.M in X20CrMoV121 steel weldment by the small punch-creep-(SP-Creep) test using miniaturized specimen($10{\times}10{\times}0.5mm$). The W.M microstructure possesses the higher creep resistance and shows lower creep strain rate than the B.M and CGHAZ. In the lower creep load the highest creep strain rate is exhibited in CGHAZ, whereas in the higher creep load the B.M represents the high creep strain rate. The power law correlation for all microstructures exists between creep rate and creep load at $600^{\circ}C$. The values of creep load index (n) based on creep strain rate for B.M, CGHAZ, and W.M are 7.54, 4.23, and 5.06, respectively and CGHAZ which shows coarse grains owing to high welding heat has the lowest creep loade index. In all creep loads, the creep life for W.M shows the highest value.

폴리폰설 중공사막에 대한 산소와 질소의 수착 및 투과특성 (Sorption and Permeation Characteristics of Oxygen and Nitrogen for Polysulfone Hollow-Fiber Membrane)

  • 조정식;김종수;이광래
    • 멤브레인
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    • 제9권1호
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    • pp.25-35
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    • 1999
  • 산소농축공기 제조용 폴리설폰 실관막에 대한 산소.질소의 수착 및 투과실험을 수행하였다. 폴리설폰 실관막에 대한 산소의 수착량이 질소의 수착량보다. 1.5배 ~2 배 높았다. 저압영역(약 3 kgf/$cm^2$이하) 에서는 Henry-type 수착량 ($C_D$)이 전체수착량의 약 15% 이었으며, Langmuir 수착이 약 85%이었다. 고압영역(약 3 kgF/$cm^2$이상)에서는 Langmuir 수착은 거의 포화되어 일정한 값에 도달하였으며, Henry 용해에 의한 수착($C_D$ = $k_D$.p) 의 증가에 의하여 전체 수착량이 증가하였다. 산소와 질소의 수착은 dual-mode sorption 모델을 만족시켰다. 산소의 투과 활성화에너지(Ep)가 질소보다 컸고, 이상분리인자 (${O_2}/{N_2}$)는 2~4를 나타내었으나 , 혼합물의 실제 분리인자는 1.7 ~2.2로 낮아졌다.

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Study of the Production of Alkaline Keratinases in Submerged Cultures as an Alternative for Solid Waste Treatment Generated in Leather Technology

  • Cavello, Ivana A.;Chesini, Mariana;Hours, Roque A.;Cavalitto, Sebastian F.
    • Journal of Microbiology and Biotechnology
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    • 제23권7호
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    • pp.1004-1014
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    • 2013
  • Six nonpathogenic fungal strains isolated from alkaline soils of Buenos Aires Province, Argentina (Acremonium murorum, Aspergillus sidowii, Cladosporium cladosporoides, Neurospora tetrasperma, Purpureocillium lilacinum (formerly Paecilomyces lilacinus), and Westerdikella dispersa) were tested for their ability to produce keratinolytic enzymes. Strains were grown on feather meal agar as well as in solid-state and submerged cultures, using a basal mineral medium and "hair waste" as sole sources of carbon and nitrogen. All the tested fungi grew on feather meal agar, but only three of them were capable of hydrolyzing keratin, producing clear zones. Among these strains, P. lilacinum produced the highest proteolytic and keratinolytic activities, both in solid-state and submerged fermentations. The medium composition and culture conditions for the keratinases production by P. lilacinum were optimized. Addition of glucose (5 g/l) and yeast extract (2.23 g/l) to the basal hair medium increased keratinases production. The optimum temperature and initial pH for the enzyme production were $28^{\circ}C$ and 6.0, respectively. A beneficial effect was observed when the original concentration of four metal ions, present in the basal mineral medium, was reduced up to 1:10. The maximum yield of the enzyme was 15.96 $U_c/ml$ in the optimal hair medium; this value was about 6.5-fold higher than the yield in the basal hair medium. These results suggest that keratinases from P. lilacinum can be useful for biotechnological purposes such as biodegradation (or bioconversion) of hair waste, leading to a reduction of the environmental pollution caused by leather technology with the concomitant production of proteolytic enzymes and protein hydrolyzates.

폐염전에서 채취한 함초(Salicornia herbacea L.)의 항산화 효과 (Antioxidative Effect of Salicornia herbacea L. Grown in Closed Sea Beach)

  • 한승관;김선민
    • 한국식품영양과학회지
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    • 제32권2호
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    • pp.207-210
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    • 2003
  • 폐염전에서 채취한 함초의 항산화 효과를 알아보기 위해 식육에 함초를 첨가하여 5$^{\circ}C$에서 저장기간 14일 동안의 TBARS치를 살펴보았다. 그 결과 동결건조한 잎(CBf3L-F)이 BHT 다음으로 높은 항산화 효과를 보였다. 유지산화 안정도를 측정 한 결과에서 구운소금(roasted salt)은 산화를 촉진하였으나 온풍건조한 줄기 (CSBS-D)는 ascorbic acid보다 높은 항산화 효과를 나타냈다 이 것은 단시간의 유지산화안 정 에는 동결건조하는 쪽이, 장기간의 산화 안정에는 온풍건조하는 것이 좋을 것으로 생각된다. 특히, 시료에 대한 함초의 함량이 증가됨에 따라 유지산화 억제 효과가 증가함을 나타냈는데 시료의 10% 함초를 첨가한 것은 천연 항산화제인 a-tocopherol을 1% 첨가한 것과 비슷한 항산화 효과를 나타냈다. 이 것은 폐염전 함초가 천연 항산화 물질로서 가능성이 있음을 시사한다.

잔디의 물질생산과 성장해석에 관한 연구 (A Study on the Dry Matter Production and Growth Analysis of Zoysia japonica)

  • Jin, AHee Sung;Joon Huh
    • The Korean Journal of Ecology
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    • 제9권3호
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    • pp.161-184
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    • 1986
  • An experiment was made in order to analyze the growth characteristics and productivity of Zoysia japonica under control, mowing and TIBA treatment conditions at the experimental farm of Kyung Hee univ. from May 26 to Oct. 1 in 1985. The field was planned by the randomized block design method and each treatment was given to three plots (2${\times}$2, 4${\times}$4 and 10${\times}$10 cm) and was replicated three times. Each plot was 1$m^2$ for Zoysia japonica. The sampling of each plot was taken once a week after sowing. In order to know the dry matter of total standing crops, kept 9$0^{\circ}C$ and weighted each organ of the plants. Total leaf area of a plant was measured by drawing method. The author adopted the growth analysis of English School. The increasing rates of numbers of leaf and stem were remarkably high in each plot between 10th and 12th weak after sowing and it was highest in TIBA treated plot. The increasin rate of leaf area in each plot was remarkably high beween 10th and 12th week and the maximum value of leaf area was 274.00c$m^2$ in TIBA treated plot of 100 plants/$m^2$. The increasing rate of standing crop was remarkably high between 10th and 12th week and the high increasing tendency in TIBA plot resulted from TIBA. The positive correlationship was founded between standing crop and leaf area. The evaporation rather than temperature acted as a main factor of negative correlation with standing crop during the experiment period. Solar radiation had a high positive correlation in the lower density of plot. C/F ratio was low, during the growth period, from 10th to 12th week after sowing and was low in the higher density under each treated plot. T/R ratio was not constant during the sampling period but was high in the lower density. The increasing rates of RGR and NAR were high between 11th and 12th week after sowing. Leaf area ratio was high in higher density in each plot and not constant in all treated plot.

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농업인의 營農유형에 따른 健康管理 상태 (The Farmers′ health management status compared with different farming types)

  • 신영숙;정금주;이승교;박양자
    • 한국농촌생활과학회지
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    • 제9권2호
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    • pp.51-62
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    • 1998
  • This study was performed to suggest the health management of farmers compared with different farming types, such as rice plant, livestock, horticulture, orchard and others, for the farmer's health enhancement. For this study, 720 subjects were selected in 8 provinces through cluster method, and relevent caculations for the analysis of the subjects were made SAS program, and tested significance with x$^2$ and F value, those probability levels were 0.1%, 1% and 5%. Among the subjects, aged 40's were 38%, females 66%, elementary graduates (32%), and think of living conditions were average (67%). In the self-consciousness test for health, there was no significant difference of farmers with farming types. In the aspect of agricultural work situation, they took holidays according to the weather conditions or no pressed work to be done. And They took a break “when they feel tired during work”. For the recovery of fatigue, sleeping was chosen as the most favorite (68%) followed bathing (17%). but exercise was the lowest (7%). In the case of working conditions, 74% of them replied they work under average condition, and only 9% of them thought they were under pleasant surroundings. And 37% of them have had healthy food, for health practice and restorative for health. 20% of them have had breakfast irregularly. In addition to the regular meal intake, sufficient re자 and pleasant agricultural working conditions would be necessary for health, and the farmers themselves should recognize the importance and care of health. The project for enhancement of the farmers' health is needed and who should give guideline to have the responsibility for health.

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인삼추출물의 장기적인 급여가 흰쥐의 혈중 CO-Hb 제거에 미치는 영향 (Effect of Chronic Treatment of Ginseng Extract on the Clearance of Blood Carbon Monoxide in Rat)

  • Lee, Young-Gu;Sohn, Hyung-Ok;Lim, Heung-Bin;Lee, Dong-Wook
    • Journal of Ginseng Research
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    • 제19권3호
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    • pp.225-230
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    • 1995
  • The effect of long-term ginseng (Panax ginseng C.A. Meyer) administration on the clearance of carboxyhemoglobin (CO-Hb) and the property of blood gases was investigated in rats. Rats were received ginseng water extract (0.025% in drinking water) for 42 weeks starting at the age of 6 weeks. They were exposed to the diluted mainstream smoke generated from 15 filter cigarettes for 20 min in a round polycarbonate chamber (D37 cmXH13 cm). Under this condition, the mean CO-Hb content of control and the ginseng-treated rats immediately after the exposure was nearly the same as 13.8$\pm$2.9 f) and 13.9$\pm$1.6%, respectively. However, CO-Hb was more rapidly removed from blood in the ginseng treated rats than in untreatEd control with the laps of time, namely, its biological half life In the former was 36.9$\pm$1.5 min and in the latter was 56.9$\pm$13.2 min. Although long-term ginseng treatment did not affect the content of hemoglobin and blood pH of rats, it slightly increased blood oxygen content and its partial pressure value, and decreased levels of carbon dioxide and bicarbonate. These results suggest that long-term administration of rats with ginseng extract accelerate the elimination of CO from the blood. This effect seems to be related to the enhancement of oxygen consumption of the rat by a certain action of ginseng components as previously reported.

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$({Zn}_{1/3}{Nb}_{2/3}){O}_{2}$의 첨가가 세라믹스의 상변화 및 유전특성에 미치는 영향 (Effect of $({Zn}_{1/3}{Nb}_{2/3}){O}_{2}$ Addition on the phase changes and dielectric properties of ${BaTiO}_{3}-{3TiO}_{2}$ceramics)

  • 김상근;박찬식;변재동;김경용
    • 대한전기학회논문지
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    • 제44권8호
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    • pp.1068-1074
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    • 1995
  • Effect of (Zn$_{1}$3/Nb$_{2}$3/) $O_{2}$ addition on the phase changes and microwave dielectric properties of BaTi $O_{3}$-3Ti $O_{2}$ ceramics were investigated. Addition of (Zn$_{1}$3/Nb$_{2}$3/) $O_{2}$ to BaTi $O_{3}$-3Ti $O_{2}$ resulted in the formation of Ba $Ti_{4}$$O_{9}$, $Ba_{2}$ $Ti_{9}$ $O_{20}$, Ba(Zn$_{1}$3/Nb$_{2}$3/) $O_{3}$, and Ti $O_{2}$ phases. Ba $Ti_{4}$$O_{9}$ phase was gradually transformed to $Ba_{2}$ $Ti_{9}$ $O_{20}$. This was identified by XRD and microstructure. As the Ba $Ti_{4}$$O_{9}$ phase transformed to $Ba_{2}$ $Ti_{9}$ $O_{20}$ phase, the dielectric constant increased to 37.5. Q*f$_{o}$ value was 40000 at x=0.04, and the temperature coefficient of resonant frequency was +10ppm/.deg. C.C.. C.C.

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Development of Sequence-Based DNA Markers for Evaluation of Phylogenetic Relationships in Korean Watermelon Varieties

  • Lee, Hee-Jeong;Cho, Hwa-Jin;Lee, Kyung-Ah;Lee, Min-Seon;Shin, Yoon-Seob;Harn, Chee-Hark;Yang, Seung-Gyun;Nahm, Seok-Hyeon
    • Journal of Crop Science and Biotechnology
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    • 제10권2호
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    • pp.98-105
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    • 2007
  • Phylogenetic relationships in Korean watermelons were evaluated by genetic similarity coefficients using 15 SSR(simple sequence repeat), 14 SCAR(sequence characterized amplified region) and 14 CAPS(sequence characterized amplified region) markers. The SSR markers were selected from previously reported melon and watermelon SSRs through testing polymorphisms within a set of commercial $F_1$ varieties. The SCAR and CAPS markers were developed from polymorphic AFLP(amplified fragment length polymorphism) markers between inbred lines 'BN4001' and 'BN4002'. From the AFLP analysis, 105 polymorphic fragments were identified between the inbred lines using 1,440 primer combinations of EcoRI+CNNN and XbaI+ANNN. Based on the sequencing data of these polymorphic fragments, we synthesized sequence specific primer pairs and detected clear and reliable polymorphisms in 27 primer pairs by indels(insertion/deletion) or RFLP(restriction fragment length polymorphism). A total of 43 sequence-based PCR markers were obtained and polymorphic information content(PIC) was analyzed to measure the informativeness of each marker in watermelon varieties. The average PIC value of SCAR markers was 0.41, which was similar to that of SSR markers. Genetic diversity was also estimated by using these markers to assess the phylogenetic relationships among commercial varieties of watermelon. These markers differentiated 26 Korean watermelon varieties into two major phylogenetic groups, but this grouping was not significantly correlated with their morphological and physiological characteristics. The mean genetic similarity was 66% within the complete set of 26 commercial varieties. In addition, these sequence-based PCR markers were reliable and useful to identify cultivars and genotypes of watermelon.

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