• Title/Summary/Keyword: $U_3 O_8$

검색결과 507건 처리시간 0.029초

체장조성으로서 생잔율를 추정하는 방법 - I (APPROXIMATE ESTIMATION OF THE SURVIVAL RAT IN FISH POPULATION UTILIZING THE LENGTH COMPOSITION)

  • 신상택
    • 한국수산과학회지
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    • 제9권2호
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    • pp.143-150
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    • 1976
  • 동일 년급군 체장에 관한 도수분포는 정규분포를 하는데, 어류자원의 감소계수를 z라 할 때 x 세 년급군의 미수가 $N_x=N_o\exp(-zx)$로 표시된다. 위의 두가지 사실에다 체장조성표를 이용하여 생잔율 $\varrho^{-z}$ 추정하는 방법을 연구한 결과를 요약하면 다음과 같다. 1. 연령, 분업에 관한 정밀조정표(표본)로부터 각년급군별 모체장평균, 모분산의 불편추정치($\bar{x},S^2$ 소표본일 때는 S^2 대신 $n/n-1{\cdot}S^2$를 구하였다. 2. 표본에서 구한 각 연금군별 모체장평균의 불편추정치$(\bar{x})$간의 경향선식과 각 년급군별 모분산($S^2$ 혹은 $n/n-1{\cdot}S^2$의 불편추정치간의 경향선식을 구하였다. 3. 각 경향선식에서 년급군별 모체장평균치와 모분산의 추정치$\hat{u},\hat{\sigma^2}$를 구하였다. 4. 각 년급군별로 모체장평균이 불편추정치$(\bar{x})$와 경향식에서 구한 모체장평균의 추정치$(\hat{u})$와의 차에 관한 유의성검정을 하고 또 각 년급군별로 모분산의 불편추정치($S^2$ 혹을 $n/n-1{\cdot}S^2$와 경향선식에서 구한 모분산의 추정치$\hat{\sigma}^2$와의 차에 관한 유의성검정을 하였다. 5. 유의성검정에서 두 종류 가운데 적어도 하나가 유의적이면 유의적인 년급군의 모체장평균(u)과 모분산$(\sigma^2)$을 모체장평균의 불편추정치$(\bar{x})$와 모분산의 불편추정치($S^2$ 혹은 $n/n-1{\cdot}S^2$로 한다. 2종의 검정이 유의적이 아닌 때는 해당하는 년급군의 모체장평균(u)과 모분산$\sigma^2$을 경향선식에서 구한 모체장평균의 추정치$\hat{u}$와 모분산의 추정치$(\hat\sigma^2)$로 하였다. 표본이 없는 년급군의 모체장평균(u)과 모분산$(\sigma^2)$도 역시 경향선식에서 구한 모체장평균 및 모분산의 추정치$\hat{u},\;\sigma^2$로 하였다. 6. 모체장평균(u)과 모분산$(\sigma^2)$이 추정되면 정규곡선면적표를 이용하여 년급군별로 각 체장계급에 해당하는 확률표를 만들었다. 7. 서로 이웃하는 체장계급의 비를 이용하여 생잔율 $\varrho^{-z}$ 값들을 구하였다. 8. $\varrho^{-z}$값들 중 이상적인 값은 유의적이면 기각하고 나머지 값으로 평균생잔율과 그 분산, 표준편차, 신뢰한계를 구하였다. 9. 향해 및 동지나해에 있어서 한국기선저인망에 어획된 참조기의 연령 및 체장에 관한 정밀조정표와 체장조직성표를 이용하여 년평균생잔율 $\varrho^{-z}$와 그 분산, 표준편차, 신뢰계수 $95\%$의 신뢰구분과 연평균 감소계수 Z를 구하였다.

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Functional characterization of the distal long arm of laminin: Characterization of Cell- and heparin binding activities

  • Sung, Uhna;O′Rear, Julian J.;Yurchenco, Peter D.
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1995년도 제3회 추계심포지움
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    • pp.107-113
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    • 1995
  • Basement membrane laminin is a multidomain glycoprotein that interacts with itself, heparin and cells. The distal long arm plays major cell and heparin interactive roles. The long arm consists of three subunits (A, B1, B2) joined in a coiled-coil rod attached to a terminal A chain globule (G). The globule is in turn subdivided into five subdomains (Gl-5). In order to analyze the functions of this region, recombinant G domains (rG, rAiG, rG5, rGΔ2980-3028) were expressed in Sf9 insect cells using a baculovirus expression vector. A hybrid molecule (B-rAiG), consisting of recombinant A chain(rAiG) and the authentic B chains (E8-B)was assembled in vitro. The intercalation of rAiG into E8-B chains suppressed a heparin binding activity identified in subdomain Gl-2. By the peptide napping and ligand blotting, the relative affinity of each subeomain to heparin was assigned as Gl> G2= G4> G5> G3, such that G1 bound strongly and G3 not at all. The active heparin binding site of G domain in intact laminin appears to be located in G4 and proximal G5. Cell binding was examined using fibrosarcoma Cells. Cells adhered to E8, B-rAiG, rAiG and rG, did not bind on denatured substrates, poorly bound to the mixture of E8-B and rG. Anti-${\alpha}$6 and anti-${\beta}$1 integrin subunit separately blocked cell adhesion on E8 and B-rAiG, but not on rAiG. Heparin inhibited cell adhesion on rAiG, partially on B-rAiG, and not on E8. In conclusion, 1) There are active and cryptic cell and heparin binding activities in G domain. 2) Triple-helix assembly inactivates cell and heparin binding activities and restores u6131 dependent cell binding activities.

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동해안 석호의 육수학적 조사(1): 청초호 (The Limnological Survey of Lagoons in the Eastern Coast of Korea (1): Lake Chungcho)

  • 이상균;권상용;김동진;김범철;허우명
    • 생태와환경
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    • 제34권3호통권95호
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    • pp.206-214
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    • 2001
  • 1998년부터 2000년까지 겨울 결빙기를 제외한 청초호의 수질 및 영양상태의 판정결과 부영양화가 심각한 것으로 조사되었다. 투명도는 0.4${\sim}$1.3 m로 비교적 낮은 값을 보였으며, COD농포는 전 조사지점에서 $3.0{\pm}1.0\;mgO_2/L$이었다. 염분은 $29.3{\pm}5.5\;ppt$로 매우 높았으며, 수심 약 0.5${\sim}$l.5 m에서 염분에 의한 화학성층(chemocline)이 형성되어 심층에 산소공급이 제한되었다. 또한 표층보다 심층수의 수온이 높은 수온역전현상이 관찰되기도 하였다. 표층수의 총인은 0.048${\sim}$0.253 mgP/L, 총질소는 0.9${\sim}$2.4 mgN/L의 범위로 나타났으며, 청초호에서의 TN/TP 비는 대체적으로 20 이하로 질소가 수중 생물의 성장과 생성에 제한 요소로 작용할수도 있음을 시사하였다. 그러나 일반적으로 인과 질소의 농도가 높게 유지되어 총질소와 총인의 비로서 제한 요소를 파악하는 것은 무리가 따르는 것으로 판단된다. 유입수가 유입되는 정점 1보다는 해수의 영향이 많은 연안으로 갈수록 점차 TN/TP비가 감소하여 해수의 영향이 클수록 인함량에 대한 질소함량비가 상대적으로 감소하는 것으로 사료된다. 조사기간 식물플랑크톤의 경우는 연중 녹조류인 Microspora sp.가 우점하였으며, 식물플랑크톤에의한 Chl. a값은 매년 감소하는 반면 부유물질의 농도는 점차 증가하여 무기현탁물의 부유물질에 대한 기여도가 점차 증가하고 있음을 알 수 있다. 청초호의 엽록소 a농도는 각 정점 평균 $14.0{\pm}25.0\;mg/m^3$으로 나타나 U.S.EPA 기준으로 볼 때 부영양호로 분류되며, 여름 성장기엽록소 a, 투명도,및 총인의 평균치를 이용한 부영양화도지수 (TSI)도 평균 59${\sim}$77로 부영양 상태로 나타났다.

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사료내 비타민 A와 E의 계란내 이행시 상호작용과 비타민 A의 다량투여에 따른 계란 및 간내 함량 변화 (Study on the Interaction between Vitamins A and E on Their Transfer from Diet to Chicken Eggs, and Effect of Flood-dosing of Dietary Vitamin A on its Content in Eggs and Livers)

  • 강경래;이창환;남기택;강창원
    • 한국가금학회지
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    • 제21권4호
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    • pp.227-237
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    • 1994
  • This study was conducted to investigate the interaction of vitamins A and E on their transfer from diet to chicken eggs and the effect of vitamin A flood-dosing on its concentration in eggs and livers. In Experiment I, forty-two 45-wk-old brown layers (Bobeock) were divided into seven groups and fed one of seven diets: control, three vitamin A supplemented diets(8, OOO, 16, 000, and 64, 000 IU /kg diet) or three vitamin E supplemented diets (50, 100, and 200 IU/kg diet). In Experiment II, a total of thirty-two 35-wk-old white layers (Hy-ine) were divided into four groups and fed one of four diets :control, vitamin A 20, 00O+vitamin E 200 TU /kg, vitamin A 50, O00+vitamin E 200 IU /kg or vitamin A 100, OO0+vitamin E 200 lU/kg supplemented diets. In Experiment III, a total of fifty-six 35-wk-old white layers (Hy-line) was divided into four groups and fed one of four diets: control or three vitamin A supplemented diets (80, 000, 120, 000 and 160, 000 lU/kg diet). In Experiment I, vitamin E levels of egg yolk in hens fed the vitamin A supplemented diets decreased as dietary vitamin A level increased (P

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AU-rich elements (ARE) found in the U-rich region of Alu repeats at 3' untranslated regions

  • An, Hyeong-Jun;Lee, Kwang-Hyung;Bhak, Jong-Hwa;Lee, Do-Heon
    • 한국생물정보학회:학술대회논문집
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    • 한국생물정보시스템생물학회 2004년도 The 3rd Annual Conference for The Korean Society for Bioinformatics Association of Asian Societies for Bioinformatics 2004 Symposium
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    • pp.77-85
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    • 2004
  • A significant portion (about 8% in human genome) of mammalian mRNA sequences contains AU(Adenine and Uracil) rich elements or AREs at their 3' untranslated regions (UTR). These mRNA sequences are usually stable. ARE motifs are assorted into three classes. The importance of AREs in biology is that they make certain mRNA unstable. We analyzed the occurrences of AREs and Alu, and propose a possible mechanism on how human mRNA could acquire and keep A REs at its 3' UTR originated from Alu repeats. Interspersed in the human genome, Alu repeats occupy 5% of the 3' UTR of mRNA sequences. Alu has poly-adenine (poly-A) regions at the end that lead to poly -thymine (poly-T) regions at the end of its complementary Alu. It has been discovered that AREs are present at the poly -T regions. In the all ARE's classes, 27-40% of ARE repeats were found in the poly -T region of Alu with mismatch allowed within 10% of ARE's length from the 3' UTRs of the NCBI's reference m RNA sequence database. We report that Alu, which has been reported as a junk DNA element, is a source of AREs. We found that one third of AREs were derived from the poly -T regions of the complementary Alu.

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질산화 토양컬럼에서 NH4-N 농도의 영향

  • 정경훈;최형일;정오진;김명희;임병갑;김우항
    • 한국환경과학회:학술대회논문집
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    • 한국환경과학회 2005년도 봄 학술발표회지 제14권(제1호)
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    • pp.377-379
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    • 2005
  • 실험실 규모의 토양컬럼을 사용하여 고농도의 암모니아성 질소의 질산화 영향을 실험한 결과 다음과 같은 결론을 얻었다. 1) 유입수 NH$_{4}$-N의 농도 50 mg/L와 100 mg/L인 경 우 HRT 48시간에서도 NH$_{4}$-N가 99%정도 제거되었으며 유출수 평균 NO$_{3}$-N의 농도는 각각 46.3 mg/L와 98.3 mgh로 유입수 NH$_{4}$-N는 대부분 NO$_{3}$-N로 전환되었다. 2) 유입수 NH$_{4}$-N의 농도 200 mg/L인 경우 HRT 48시간에서 NH$_{4}$-N의 평균제거율이74.8%에 머물렀으나 토양컬럼 내부에 폭기장치를 설치한 결과 NH$_{4}$-N의 평균제거율은 94.7%로 개선되는 효과를 나타냈으며, 유입수 NH$_{4}$-N의 농도 400 mg/L인 경우에는 HRT 72시 간에서도 질산화가 불안정하였으나 마찬가지로 강제 폭기를 실시 한 결과 질산화가 증가하는 경향을 보였다. 4) 실험종료 후 토양컬럼 내부의 암모니아 및 아질산 산화세균을 조사한 결과 각각 1.4${\times}$10$^{5}$과 2.3${\times}$ 10$^{6}$ MPN/g${\cdot}$soil까지 증가하였다.

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Structural Behavior of Mixed $LiMn_2O_4-LiNi_{1/3}Co_{1/3}Mn_{1/3}O_2$ Cathode in Li-ion Cells during Electrochemical Cycling

  • 윤원섭;이상우
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2011년도 춘계학술발표대회
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    • pp.5-5
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    • 2011
  • The research and development of hybrid electric vehicle (HEV), plug-in hybrid electric vehicle (PHEV) and electric vehicle (EV) are intensified due to the energy crisis and environmental concerns. In order to meet the challenging requirements of powering HEV, PHEV and EV, the current lithium battery technology needs to be significantly improved in terms of the cost, safety, power and energy density, as well as the calendar and cycle life. One new technology being developed is the utilization of composite cathode by mixing two different types of insertion compounds [e.g., spinel $LiMn_2O_4$ and layered $LiMO_2$ (M=Ni, Co, and Mn)]. Recently, some studies on mixing two different types of cathode materials to make a composite cathode have been reported, which were aimed at reducing cost and improving self-discharge. Numata et al. reported that when stored in a sealed can together with electrolyte at $80^{\circ}C$ for 10 days, the concentrations of both HF and $Mn^{2+}$ were lower in the can containing $LiMn_2O_4$ blended with $LiNi_{0.8}Co_{0.2}O_2$ than that containing $LiMn_2O_4$ only. That reports clearly showed that this blending technique can prevent the decline in capacity caused by cycling or storage at elevated temperatures. However, not much work has been reported on the charge-discharge characteristics and related structural phase transitions for these composite cathodes. In this presentation, we will report our in situ x-ray diffraction studies on this mixed composite cathode material during charge-discharge cycling. The mixed cathodes were incorporated into in situ XRD cells with a Li foil anode, a Celgard separator, and a 1M $LiPF_6$ electrolyte in a 1 : 1 EC : DMC solvent (LP 30 from EM Industries, Inc.). For in situ XRD cell, Mylar windows were used as has been described in detail elsewhere. All of these in situ XRD spectra were collected on beam line X18A at National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory using two different detectors. One is a conventional scintillation detector with data collection at 0.02 degree in two theta angle for each step. The other is a wide angle position sensitive detector (PSD). The wavelengths used were 1.1950 ${\AA}$ for the scintillation detector and 0.9999 A for the PSD. The newly installed PSD at beam line X18A of NSLS can collect XRD patterns as short as a few minutes covering $90^{\circ}$ of two theta angles simultaneously with good signal to noise ratio. It significantly reduced the data collection time for each scan, giving us a great advantage in studying the phase transition in real time. The two theta angles of all the XRD spectra presented in this paper have been recalculated and converted to corresponding angles for ${\lambda}=1.54\;{\AA}$, which is the wavelength of conventional x-ray tube source with Cu-$k{\alpha}$ radiation, for easy comparison with data in other literatures. The structural changes of the composite cathode made by mixing spinel $LiMn_2O_4$ and layered $Li-Ni_{1/3}Co_{1/3}Mn_{1/3}O_2$ in 1 : 1 wt% in both Li-half and Li-ion cells during charge/discharge are studied by in situ XRD. During the first charge up to ~5.2 V vs. $Li/Li^+$, the in situ XRD spectra for the composite cathode in the Li-half cell track the structural changes of each component. At the early stage of charge, the lithium extraction takes place in the $LiNi_{1/3}Co_{1/3}Mn_{1/3}O_2$ component only. When the cell voltage reaches at ~4.0 V vs. $Li/Li^+$, lithium extraction from the spinel $LiMn_2O_4$ component starts and becomes the major contributor for the cell capacity due to the higher rate capability of $LiMn_2O_4$. When the voltage passed 4.3 V, the major structural changes are from the $LiNi_{1/3}Co_{1/3}Mn_{1/3}O_2$ component, while the $LiMn_2O_4$ component is almost unchanged. In the Li-ion cell using a MCMB anode and a composite cathode cycled between 2.5 V and 4.2 V, the structural changes are dominated by the spinel $LiMn_2O_4$ component, with much less changes in the layered $LiNi_{1/3}Co_{1/3}Mn_{1/3}O_2$ component, comparing with the Li-half cell results. These results give us valuable information about the structural changes relating to the contributions of each individual component to the cell capacity at certain charge/discharge state, which are helpful in designing and optimizing the composite cathode using spinel- and layered-type materials for Li-ion battery research. More detailed discussion will be presented at the meeting.

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일부농촌지역의 모자보건사업중 분만상태와 예방접종실시에 관한 조사 연구 (A Study on Delivery Environments and Immunization practice of the Maternal St Child Health Services in a Rural Area)

  • 주채복
    • 대한간호학회지
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    • 제5권2호
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    • pp.92-103
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    • 1975
  • This study was conducted to find out status of delivery environments, delivery attendants, and various immunization practices towards 513 babies who were born during the period from January 1, 1972 to December 31, 1974, in Dongnae Area, Shindong Myon, Chunseong Gun, Ganwon Do. The results and findings obtained from the study are summarized as follows : 1. Of all deliveries, 10.7% of the babies were reported born at the hospitals. 2. Deliveries attended by qualified professionals such as, doctors, midwives or public health nurses, were 22.2% of the total deliveries. Those who delivered alone without having anyone's assistants were as much as 9.7%, The percentage of the deliveries attended by the professional groups were increased year by year among the younger group mothers with the babies birth order being first or second place. 3. Sewing scissors were most frequently used as a tool for cutting the umbilical cord indicating 87.5% in this area. Sterilized tools were used among 50.3% of the women. 4. The usage af vinyl sheet and cement bag paper were frequently used as a delivery sheet, indicating 32.3%. Delivery set which was distributed by the health center was used 18.0%. (excluded the deliveries attended by professional attendants) 5. Immunization practices for the infant were observed as relatively high rate: 92.8% of the infant received D. p. T., 81, 3u/o received against poliomyelitis, 52.8% for small pox, 78.9% with B. C. G., and 18.5%against measles. The percentage af babies complected 3 times shot for D. P. T. and 2 times shot for poliomyelitis vaccine turned out be to 67.8% and 87.5%, respectively.

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핵의학 이용 방사핵종의 투여후 혈중 $PGE_2$의 변동 (Increased Plasma $PGE_2$ Levels after Administration of Radionuclides Used in Nuclear Medicine)

  • 유용운
    • Journal of Radiation Protection and Research
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    • 제14권1호
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    • pp.8-15
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    • 1989
  • $^{99m}TC,\;^{67}Ga,\;^{131}I,\;^{32}P$각각을 웅성백서에 투여하여 생체에 미치는 혈중 독성의 영향을 측정 비교하였다. 핵종의 투여량은 통상 인체에 주사되는 양을 기준으로하여 조절 하였으며 생화학적 반응 지표로 혈중 BUN, Creatinine, SGOT SGPT와 $PGE_2$의 활성도출 측정하였다. $^{99m}Tc$의 효과로 Creatinine의 변동은 없었으며 BUN, SGOT 및 $PGE_2$활성도가 투여 전에 비하여 증가된 경향을 보였으나 통계적 의의는 없었다. $^{67}Ga,\;^{131}I$$^{32}P$의 경우 BUN, SGPT 및 SGOT 에서의 증가는 임상적 의의는 없었으나 $PGE_2$는 정상치 보다 크게 상승 하였다. 한편 $^{238}U$이 가장 심한 독성을 나타내었다. 따라서 핵의학에서 이용되는 핵종의 방사성 독성의 효과를 평가할 경우 혈중 $PGE_2$의 측정법이 유용할 것으로 생각된다.

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Measurement of TOF of fast neutrons with 238U target

  • Li, Meng;Guan, Yuanfan;Lu, Chengui;Zhang, Junwei;Yuan, Xiaohua;Duan, Limin;Yang, Herun;Hu, Rongjiang;He, Zhiyong;Wei, Xianglun;Ma, Peng;Gan, Zaiguo;Yang, Chunli;Zhang, Hongbin;Chen, Liang;Qiu, Tianli;Hou, Yikai
    • Nuclear Engineering and Technology
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    • 제53권6호
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    • pp.1964-1969
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    • 2021
  • We developed a Dual-PPACs detector for fast neutron measurements that consists of two sets of PPAC: conventional PPAC and fission PPAC. A238U(U3O8) coating is placed in the fission PPAC's anode, which is used as the neutrons conversion layer. An experiment was performed to measure neutron time-of-flight (TOF) in which 252Cf spontaneous fission source was used. An excellent time resolution of 164ps has been observed at 6 mbar in isobutene gas. With the excellent time resolution of Dual-PPACs detector, exact neutron energy can be extracted from the timing measurement. The experimental detection efficiency was 1.9 × 10-7, consistent with the efficiency of 2.5 × 10-7 given by a Geant4 simulation. Ultimately, the results show that the Dual-PPACs detector is a suitable candidate for measuring fast neutrons in the future CiADS system.