• 제목/요약/키워드: P/A ratio

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철근콘크리트 휨부재의 최소철근비에 대한 고찰 (An Examination of the Minimum Reinforcement Ratio for Reinforced Concrete Flexural Members)

  • 최승원
    • 한국구조물진단유지관리공학회 논문집
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    • 제21권6호
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    • pp.35-43
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    • 2017
  • 철근콘크리트 휨부재의 최소철근비는 부재의 취성 파괴를 방지하기 중요한 설계 인자이다. 콘크리트구조기준과 도로교설계기준에서 사용되는 최소철근비는 단면의 유효 깊이 및 모멘트 팔길이에 대한 가정을 통해 산정되었다. 따라서 이 연구에서는 재료 모델과 힘의 평형 관계를 통해 합리적으로 최소철근비를 산정할 수 있는 방법을 제안하였다. 연구 결과 도로교설계기준의 포물-사각형 곡선을 통해 산정된 최소 철근비는 현재 설계 기준에 의한 최소철근비의 약 52~80% 수준으로 산정되어 경제적인 설계가 가능한 것으로 나타났다. 또한, 재료 모델을 통한 최소철근량이 배치된 부재의 연성 능력은 현재 설계 기준에 의한 값의 약 89% 수준으로 평가되었으나, 부재의 연성도는 7 이상으로 충분한 연성능력을 보였다. 따라서 제안된 포물-사각형 곡선을 통한 최소철근비는 휨부재 설계의 이론적 합리성 뿐만 아니라 안전성 및 경제성을 확보할 수 있는 것으로 나타났다.

LiYSiO4: La 열형광체의 온도에 따른 열발광 특성 (Thermoluminescent Properties by the Cooling Temperature and Grain Size in the LiYSiO4 : La Phosphors)

  • 김영국
    • 한국재료학회지
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    • 제19권9호
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    • pp.494-498
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    • 2009
  • The thermoluminescent phosphors of LiYSi$O_4$ containing rare earth metal(La) dopants of 1 wt.%5 wt.% were prepared, and their TL characteristics have been investigated as a function of parameters such as the doping level and the heating rate. The grain size and cooling temperature of the highly sensitive LiYSi$O_4$: La phosphors have been investigated. The glow curve of LiYSi$O_4$: La has two peaks ($P_1,\;P_2$), and the peak height ratio of the two peaks is called $P_2/P_1$; here, the main peak is $P_2$. Experimental results indicate that the peak height ratios of the glow curve for LiYSi$O_4$: La are clearly correlated with the grain size and cooling temperature. The maximum $P_2/P_1$ ratio 3.25, the maximum sensitivity was observed for a grain size between 100-150 ${\mu}m$. The intensity of the TL peak of the phosphors was linearly proportion to the dose of X-rays.

K2O-CaO-SiO2-P2O5계 유리의 형성 및 용출특성 (Glass Formation and Dissolution Characteristics of K2O-CaO-SiO2-P2O5)

  • 윤태민;윤영진;이용수;강원호
    • 한국재료학회지
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    • 제14권1호
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    • pp.67-72
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    • 2004
  • The glass-forming conditions are investigated in the $K_2$O-CaO-$SiO_2$ $-P_2$$O_{5}$ system with 10~65 mole% of$ P_2$$O_{5}$. Thermal properties and dissolution properties were investigated according to variation of the SiO and KO contents in selected compositions. The glass formation condition was determined when $K_2$O/$P_2$$O_{5}$ mole ratio 0~0.24, $SiO_2$/($SiO_2$+$P_2$$O_{5}$ ) mole ratio 0~0.29, and CaO/$P_2$$O_{5}$ mole ratio 0~1.00. In the result of the thermal properties, the glass transition temperature($T_{g}$) and softening temperature($T_{s}$ ) were gradually shifted to the lower temperature range with increase of $K_2$O contents. The maximum value of the chemical durability was shown in $K_2$$PO_2$$O_{5}$ mole ratio 0.17 when the $SiO_2$ contents were changed, and $K_2$O was fixed at 10 mole%. Hence the change of the $K_2$O/$P_2$$O_{5}$ mole ratio was found that a new main factor of the chemical durability.

Prognostic Significance of Preoperative Lymphocyte-Monocyte Ratio in Patients with Resectable Esophageal Squamous Cell Carcinoma

  • Han, Li-Hui;Jia, Yi-Bin;Song, Qing-Xu;Wang, Jian-Bo;Wang, Na-Na;Cheng, Yu-Feng
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권6호
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    • pp.2245-2250
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    • 2015
  • Background: The interaction between tumor cells and inflammatory cells has not been systematically investigated in esophageal squamous cell carcinoma (ESCC). The aim of the present study was to evaluate whether preoperative the lymphocyte-monocyte ratio (LMR), the neutrophil-lymphocyte ratio (NLR), and the platelet-lymphocyte ratio (PLR) could predict the prognosis of ESCC patients undergoing esophagectomy. Materials and Methods: Records from 218 patients with histologically diagnosed ESCC who underwent attempted curative surgery from January 2007 to December 2008 were retrospectively reviewed. Besides clinicopathological prognostic factors, we evaluated the prognostic value of the LMR, the NLR, and the PLR using Kaplan-Meier curves and Cox regression models. Results: The median follow-up was 38.6 months (range 3-71 months). The cut-off values of 2.57 for the LMR, 2.60 for the NLR and 244 for the PLR were chosen as optimal to discriminate between survival and death by applying receiver operating curve (ROC) analysis. Kaplan-Meier survival analysis of patients with low preoperative LMR demonstrated a significant worse prognosis for DFS (p=0.004) and OS (p=0.002) than those with high preoperative LMR. The high NLR cohort had lower DFS (p=0.004) and OS (p=0.011). Marginally reduced DFS (p=0.068) and lower OS (p=0.039) were found in the high PLR cohort. On multivariate analysis, only preoperative LMR was an independent prognostic factor for both DFS (p=0.009, HR=1.639, 95% CI 1.129-2.381) and OS (p=0.004, HR=1.759, 95% CI 1.201-2.576) in ESCC patients. Conclusions: Preoperative LMR better predicts cancer survival compared with the cellular components of systemic inflammation in patients with ESCC undergoing esophagectomy.

옥상녹화에서 토심, 토양배합비 및 지피식물에 따른 식재지반 수분 및 온도변화 (Change of the Moisture and Temperature in Planting Ground as Effected by Different Soil Thickness, Soil Mixture Ratios and Ground Cover Plants in the Green Roof System)

  • 주진희;윤용한
    • KIEAE Journal
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    • 제10권3호
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    • pp.11-16
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    • 2010
  • This paper has attempted to investigate the change in soil moisture volume and temperature of architecture by planting ground(soil thickness and soil mixture ratio) and ground cover plants(Sedum sarmentosum, Zoysia japonica, Chrysanthemum zawadskii) for middle region green roof system. For this, a test was conducted on the roof of Konkuk University building from April 2009 to October 2009. In terms of treatment, five types(SL, $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$, $P_4P_4L_2$) depending on soil mixture ratio and two types(15cm, 25cm) by soil depth were created. Results of soil moisture volume by soil mixture ratio in the 15cm soil thickness showed that the difference was significance between simple soil and mixture soil treatment, however, the statistical significance was not recognized according to soil mixture ratio. In case of 25cm soil thickness, soil moisture volume by soil mixture ratio was more higher 7Vol.%~10Vol.% in the mixture soil than simple soil treatment. In terms of districts planted ground cover plants, soil volume moisture differed among plants in the order Zoysia japonica 17.74 Vol.%$34.86^{\circ}C$, district non-planted $27.49^{\circ}C$, Sedum sarmentosum $25.11^{\circ}C$, Chrysanthemum zawadskii $23.08^{\circ}C$, Zoysia japonica $24.45^{\circ}C$ respectively So, concrete surface showed more higher $5^{\circ}C{\sim}15^{\circ}C$ than other things among the all the time. Result of inner temperature of the architecture and soil, it was measured inner of architecture $25.69^{\circ}C$, inner district non-planted $24.29^{\circ}C$, Chrysanthemum zawadskii $23.90^{\circ}C$, Zoysia japonica $24.02^{\circ}C$, Sedum sarmentosum $25.13^{\circ}C$, respectively.

안경과 콘택트렌즈 착용에 따른 근거리안위의 변화 (The Change of the Near Eye Position according to the Spectacle and Contact Lens Wearing)

  • 한선희;김봉환;김학준;박준성;박혜빈;김미정;박주형;김진솔;이경훈;김종환;하나리
    • 한국임상보건과학회지
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    • 제3권4호
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    • pp.435-443
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    • 2015
  • Purpose. This study was to investigate comparison of the near eye position according to the spectacle and contact lens wearing. Methods. We measured the AC/A ratio and near horizontal phoria using modified Thorington method in each case spectacle and contact lens wearing of equivalent spherical power after measuring the full corrected diopter for 20 subjects (men 5, woman 15, $21.15{\pm}1.35$ years) without specific ocular diseases, ocular surgery experience and vision anomalies. Results. It was shown high correlation between spectacle and contact lens wearing as AC/A ratio is a correlation coefficient 0.99 (p=0.00), near horizontal phoria is a correlation coefficient 0.95 (p=0.00). And contact lens wearing increased as AC/A ratio by $0.32{\pm}1.35$ ${\Delta}/D$ (p=0.31) and near horizontal phoria by $-0.17{\pm}2.18$ ${\Delta}$ (p=0.73) than spectacle wearing but there was no statistically significant difference. As the higher myopic grade AC/A ratio increased and then was shown decreased tendency in -6.00 D < $SED{\leq}-4.00$ D group (p>0.05) and as the higher myopic grade near exophoria increased but there was no statistically significant difference (p>0.05). Conclusions. We should consider that the subjects who had the lower AC/A ratio or higher near exophoria in -6.00 D < $SED{\leq}-4.00$ D group were necessary to measure AC/A ratio and near horizontal phoria when they were wearing contact lens because contact lens wearing tended to increase the near exophoria than spectacle wearing.

서울 강북구 일부 주민들의 고혈압 분류에 따른 영양상태 비교 (The Relationship of Nutritional Satus to the Degree of Hypertension in Residents of Kangbuk-gu, Seoul)

  • 손은정;문현경
    • 대한지역사회영양학회지
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    • 제7권3호
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    • pp.304-315
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    • 2002
  • The purpose of this study was to relate the degree of hypertension to nutritional status, in order to prepare basic data for a nutrition program. The study using the WHO standard divided the residents in Kangbuk-gu into a normal group (NG) of 254 adults with systolic blood pressure (SBP) < 130 or diastolic blood pressure (DBP) < 85; a borderline hypertensive group (BG) of 81 adults with 130 $\leq$ SBP $\leq$ 140 or 85 $\leq$ DBP $\leq$ 90; and a hypertensive group (HG) of 143 adults with SBP > 140 or DBP > 90. The mean age of HG was older than the other groups (p < 0.001). The dietary intake was investigated by the 24-hour recall method. The Ca intake as the percentage of the Korean Recommended Dietary Allowances (RDA) for the HG were higher than that of the other groups (p < 0.01). The Nutrient Adequacy Ratio (NAR) of Ca and Vit. A were below 0.75 for all three groups. The Mean Adequacy Ratio (MAR) was above 0.75 (p > 0.05) for all three groups. The Dietary Variety Score (DVS) of the NG was 22.7, and higher than those of the other groups (p > 0.05) The fasting blood sugar (p < 0.001), total cholesterol (p < 0.001), protein (p < 0.001), albumin (p < 0.01), hemoglobin (Hb) (p < 0.001), alkaline phosphatase (ALP) (p < 0.001), and creatinine (p <0.05) values of the HG were higher than those of the other groups. The Body Mass Index (BMI) and the waist-hip ratio (WHR) of the HG were higher than those of the other groups (p < 0.001) . In conclusion, these results showed that there tended to be differences among the three groups. For effective nutritional education and counseling of each group, we should furtherstudy the differences and understand their characteristics of each group in order to provide nutritional education for controling and preventing hypertension.

환경조건(環境條件)이 대두(大豆) 탄저병균(炭疽病菌)(Colletotrichum truncatum)의 부착기형성(附着器形成)에 미치는 영향(影響) (Effect of Environmental Factors on Appressorium Formation of Colletotrichum truncatum)

  • 도은수;백수봉
    • 한국균학회지
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    • 제15권3호
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    • pp.142-148
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    • 1987
  • 대두(大豆) 탄저병(炭疽病)(C. truncatum)을 공시(供試)하여 In vitro에서 광(光), pH 및 영양원(營養源)과 In vivo에서 시비수준(施肥水準)(P, K 및 Ca)이 부착기형성(附着器形成)에 미치는 영향(影響)을 조사(調査)한 바는 다음과 같다. 1. 3시간(時間) 및 6시간(時間)이 지난후의 조사(調査)에 따르면 광처리(光處理)를 한 것이 암처리(暗處理)를 한 것보다 부착기형성률(附着器形成率)이 양호(良好)하였다. 그러나 시간이 진행(進行)됨에 따라서는 각처리(各處理)에서 부착기형성률(附着器形成率)이 높아졌다. 2. 부착기형성(附着器形成)에 적정 pH는 $pH\;6{\sim}8$이었다. 3. 탄소원(炭素源) 및 질소원(窒素源) 공(供)히 무처리구(無處理區)에서 부착기형성률(附着器形成率)이 양호(良好)하였고 농도(濃度)가 높을수록 억제되는 경향이었으며 질소원(窒素源)에 비(比)하여 탄소원(炭素源)에서의 부착기형성률(附着器形成率)이 양호(良好)하였다. 그리고 시간(時間)이 경과함에 따라서 부착기형성률(附着器形成率)이 상승했다. 4. 3시간(時間) 경과후의 조사(調査)에서는 인산 및 칼륨처리(處理)는 증시(增施)했을 경우 다소 부착기형성(附着器形成)이 억제되었으나, 칼슘처리(處理)에 있어서는 무비구(無肥區)<표준비구(標準肥區)<2배비구(培肥區)의 순(順)으로 부착기형성(附着器形成)이 상당히 억제되는 경향이었다. 그러나 시간(時間)이 경과함에 따라서는 부착기형성률(附着器形成率)이 시비수준(施肥水準)과 관계없이 상당히 증가(增加)됨을 보였다.

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The Influence of Dietary Calcium and Phosphorus Imbalance on Intestinal NaPi-IIb and Calbindin mRNA Expression and Tibia Parameters of Broilers

  • Li, Jianhui;Yuan, Jianmin;Guo, Yuming;Sun, Qiujuan;Hu, Xiaofei
    • Asian-Australasian Journal of Animal Sciences
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    • 제25권4호
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    • pp.552-558
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    • 2012
  • A $2{\times}2$ factorial experiment was conducted to study the effect of dietary calcium and non-phytate phosphorus (nPP) imbalance on calbindin and NaPi-IIb mRNA levels in the small intestine and tibia parameters of broiler chicks. One hundred and forty four 1-d-old Arbor Acres male broiler chicks were divided into four treatments consisted of six replicates with six chicks each. The two dietary calcium levels were 1.10% and 0.60%, and two dietary nPP levels were 0.50% and 0.27%. Results showed that a high Ca/nPP ratio diet (4.07:1) significantly depressed feed intake and weight gain of broilers (p<0.05), but a lower Ca:nPP ratio (1.2:1) had no influence (p>0.05). Low-Ca with low-P diet resulted in low tibia minerals and tibia breaking strength of broilers, and all the tibia parameters were further decreased when the dietary ratio of Ca to P was relative higher. Low dietary Ca or P up-regulated the calbindin and NaPi-IIb mRNA expression levels. Low Ca with normal P diet up-regulated duodenal calbindin mRNA expression level to the greatest extent. Low P with a normal Ca diet significantly enhanced NaPi-IIb mRNA expression level to the highest extent. These results suggest that the calbindin and NaPi-IIb mRNA expression were enhanced by the imbalance between dietary Ca and nPP, and their expression were not only influenced by Ca or nPP level, but also the ratio of Ca:nPP.

부영양 저수지에서 식물플랑크톤 성장에 대한 제한영양염과 질소/인 비의 영향 (Effects of Nutrients and N/P Ratio Stoichiometry on Phytoplankton Growth in an Eutrophic Reservoir)

  • 김호섭;황순진
    • 생태와환경
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    • 제37권1호통권106호
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    • pp.36-46
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    • 2004
  • 소규모 부영양 저수지에서 식물플랑크톤 성장에 대한 제한영양염과 N/P무게비의 영향을 평가하기 위해 2002년 11월부터 2003년 12월까지 이루어졌다. 조사기간 동안 수체 내 DIN/DTP과 TN/TP 무게비는 각각 17${\sim}$187,33${\sim}$60의 범위로 나타났다. 용존무기질소의 대부분은 질산성 질소($NO_3$-N)형태로 존재했으며, 봄에 일시적인 암모니아 농도의 증가가 나타났다. 반면에 무기인은 8.8${\sim}$0.6 ${\mu}g\;P\;L^{-1}$의 범위로 계절에 따른 변화는 적었으며, 용존총인은 26.5 ${\sim}$ 10.1 ${\mu}g\;P\;L^{-1}$로 8월에 가장 높았고 12월에 가장 낮은 농도를 나타냈다. 엽록소 a 농도는 28.8${\sim}$109.7 ${\mu}g\;L^{-1}$의 범위였고, 식물플랑크톤 세포밀도 변화와 유사한 계절적인 변화를 보였다. 봄에는 주로 규조류(Melosira varians)와 녹조류 (Dictyosphaerium puchellum)가 우점종으로 나타난 반면 5월부터 결빙 전까지는 Osillatoria SPP., Microcystis SPP., Aphanizomenon SP. 와 같은 남조류가 우점하였다. 남조류 군집 중 Microcystis SPP.가 우점한 6월부터 12월까지 수체 내 TN/TP비는 46${\sim}$13의 범위 (평균 27${\pm}$5)였다. 영양염 첨가실험의모든 경우(17번)에서 인에 의한 제한이 나타났으며, 질소제한은 8번에 걸쳐 나타났다. 식물플랑크톤 성장률은DIN/DTP비 30이하에서 가장 크게 나타났고, 인 농도50 ${\mu}g\;P\;L^{-1}$까지는 지속적으로 증가하였다. 절대 농도에 있어서 차이가 있으나, N/P비가 동일한 상태에서의 남조류 성장은 질소 농도가 3.5 mg N $L^{-1}$인 경우 N/P 비가 1인 상태에서 성장량이 가장 컸다. 인 첨가에 따른 성장은 질소농도가 높을수록 현저히 높게 나타났다. 이러한 결과들은 수체 내 질소농도가 높은 환경에서는 식물플랑크톤성장에 대한 강한 인 제한이 나타나기 쉬운 반면, 질소제한 가능성 이 상대적으로 적음을 의미한다.