• Title/Summary/Keyword: P-Y curves

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Comparison of Water Potential Parameters in Aster scaber and Synurus deltoides Leaves Obtained from P-V Curves (P-V 곡선법에 의한 참취와 수리취의 수분포텐셜 비교)

  • Lee, Kyeong-Cheol;Jeon, Seong-Ryeol;Han, Sang-Sup
    • Korean Journal of Plant Resources
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    • v.24 no.4
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    • pp.413-418
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    • 2011
  • This study was carried out to establish a proper cultivation site and diagnose the drought-tolerance of Aster scaber and Synurus deltoides leaves by using Pressure-volume curves. In order to measure pressure-volume (P-V) curves, Aster scaber and Synurus deltoides were cut off above ground part and the tip of the cutting were placed in water, which was covered with a plastic bag. Samples were kept overnight (about 12 hours) in darkness at room temperature (20~25$^{\circ}C$) to achieve maximal turgor (full saturation). The pressure in the chamber was gradually increased from 0.3MPa to 1.8MPa by nitrogen gas. After measured, leaf samples were dried at 80$^{\circ}C$ for 48 hours and dry weight of each samples were determined. The result of the original bulk osmotic potential at maximum turgor ${\Psi}^{sat}_o$ sat was lower -0.8 MPa in Aster scaber leaves than -0.7 MPa Synurus deltoides leaves. Also the osmotic potential at incipient plasmolysis ${\Psi}^{tlp}_o$ in Aster scaber leave was -0.9 MPa. In contrast, the value of maximum bulk modulus of elasticity $E_{max}$ of Aster scaber leaves were approximately two folds higher than that of Synurus deltoides leaves. The values of the relative water content at incipient plasmolysis $RWC^{tlp}$ are all above 90% showing that the function of osmoregulation is somewhat better, and Vo/DW, Vt/DW, Ns/DW of Synurus deltoides leaves were approximately 1~2 times higher than that of Aster scaber leaves. Thus, responses to water relations of Aster scaber and Synurus deltoides such as ${\Psi}^{sat}_o$, ${\Psi}^{tlp}_o$, $E_{max}$, ${\Psi}_{P,max}$, $RWC^{tl}$ were shown that the Aster scaber leaves was slightly higher drought-tolerance than Synurus deltoides leaves. However, in both of Aster scaber and Synurus deltoides, occurring incipient plasmolysis at the high water content, have a relatively lower drought-tolerance property indicating that growth of these plants are cultivated appropriate in high moisture soil sites.

Prevalence of Metabolic Syndrome and Waist Circumference Estimation in Some Korean Adults (일부 우리나라 성인의 대사성증후군의 유병률과 허리둘레 예측치)

  • Hong, Young-Seoub;Jeong, Baek-Geun;Park, Yong-Woo;Park, Jong-Tae;Jung, Kap-Yeol;Kim, Joon-Youn;Kim, Byoung-Gwon
    • Journal of Preventive Medicine and Public Health
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    • v.37 no.1
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    • pp.51-58
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    • 2004
  • Objectives : The purpose of this study was to estimate the prevalence of metabolic syndrome, as defined by the ATP III report, in some Korean adults and use the Asian-Pacific proposed waist circumference to investigate waist circumference in some Korean adults using ROC curves. Methods : Study subjects were seventy-five thousands and ninety one persons(47,979 men and 27,111 women) who were selected among the patients who visited hospital for health evaluation from January 2000 to December 2001. All subjects were measured by height, weight, waist and hip circumferences, blood pressure and blood chemistry(lipid profile). Results : The mean age was $41.6{\pm}8.5$ years in men, $41.1{\pm}10.4$ years in women(p<0.05). Body mass index was in the normal range in 35.3% of men, and 55.9% of women. In both men and women, blood pressure, blood sugar, total cholesterol and triglyceride were positively correlated with BMI. waist circumference, and Broca's index(p<0.01). However HDL. choloesterol was correlated negatively (p< 0.01). Using ROC curve, the calculated waist circumferences were 84 cm in men(sensitivity 61.4% and specificity 64.1%) and 74 cm in women(sensitivity 65.0% and specificity 73.2%). The age adjusted prevalences of the metabolic syndrome as defined by NCEP ATP III were different for men(6.4%) and women(14.6%). The prevalence increased from 1.2% among participants aged 20 through 29years to 15.0% among participants aged over 60years in men(p<0.05) and from 1.6% to 27.4% respectively, in women. The age adjusted prevalences, as defined by using the waist circumference that was recommended by WHO's regional office for the western Pacific, were 10.6% in men and 18.5% in women. The age adjusted prevalences, as defined by using the waist circumference that was calculated by the ROC curves, were 17.1% in men and 22.4% in women. And All prevalences were increased following increased BMI and Broca's index. Conculsions : The prevalence of metabolic syndrome in some Korean adults was lower than that in western adults. Nevertheless because waist circumference was differed among race and region, application of the same criteria was not proper. Morcover, a higher awareness was required in women, because the prevalence of metabolic syndrome was rapidly increased with increment of age.

Wall Tie Member Force Curve for the Construction Tower Crane (건축용 타워크레인 마스트의 횡방향 지지요소인 월타이 부재력 특성곡선)

  • Ko, Kwang IL;Oh, W.H.;Lee, E.T.
    • Journal of Korean Society of Steel Construction
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    • v.18 no.6
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    • pp.697-706
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    • 2006
  • Tower crane's wall tie is generally used for extending of mast height according to rising of lifting height. In order to get wall tie member force this problem, this study concerning wall tie is based on load data described in manual book of 290HC model. This study made the equation of wall tie member force and computer programming for calculating wall tie member force and then get ${\theta}-P$ curves(angle-wall tie force). After considering the ${\theta}-P$ curves, optimum angle range ($48.4^{\circ}{\sim}77.2^{\circ}$) about wall ties (A), (C) members was obtained. Member force of wall tie (B) was changed from tension to compression or from compression to tension at $74^{\circ}$ in service and $54^{\circ}$ in out of service. When both horizontal force($H_A$) and torsional moment ($M_D$) were varied from (+) to (-), wall tie force(A, B, C) were changed almost symmetrically about ${\theta}$-axis. Because this study was based on wall tie analysis conditions, wall tie members in symmetric and ideal geometry shape used for analizing wall tie of tower crane, it is necessary to have more careful verification in order to apply generally the results of this study.

Differentiation of Benign from Malignant Adnexal Masses by Functional 3 Tesla MRI Techniques: Diffusion-Weighted Imaging and Time-Intensity Curves of Dynamic Contrast-Enhanced MRI

  • Malek, Mahrooz;Pourashraf, Maryam;Mousavi, Azam Sadat;Rahmani, Maryam;Ahmadinejad, Nasrin;Alipour, Azam;Hashemi, Firoozeh Sadat;Shakiba, Madjid
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.8
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    • pp.3407-3412
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    • 2015
  • Background: The aim of this study was to evaluate and compare the accuracy of diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) value, and time-intensity curve (TIC) type analysis derived from dynamic contrast-enhanced MR imaging (DCE-MRI) in differentiating benign from malignant adnexal masses. Materials and Methods: 47 patients with 56 adnexal masses (27 malignant and 29 benign) underwent DWI and DCE-MRI examinations, prior to surgery. DWI signal intensity, mean ADC value, and TIC type were determined for all the masses. Results: High signal intensity on DWI and type 3 TIC were helpful in differentiating benign from malignant adnexal masses (p<0.001). The mean ADC value was significantly lower in malignant adnexal masses (p<0.001). An ADC value< $1.20{\times}10^{-3}mm^2/s$ may be the optimal cutoff for differentiating between benign and malignant tumors. The negative predictive value for low signal intensity on DWI, and type 1 TIC were 100%. The pairwise comparison among the receiver operating characteristic (ROC) curves showed that the area under the curve (AUC) of TIC was significantly larger than the AUCs of DWI and ADC (p<0.001 for comparison of TIC and DWI, p<0.02 for comparison of TIC and ADC value). Conclusions: DWI, ADC value and TIC type derived from DCE-MRI are all sensitive and relatively specific methods for differentiating benign from malignant adnexal masses. By comparing these functional MR techniques, TIC was found to be more accurate than DWI and ADC.

Ecophysiological Interpretations on the Water Relations Parameters of Trees (IV) - Relation between Leaf Conductance and Water Potential, Relative Water Content, and Turgor Pressure in Several Conifers - (수목(樹木)의 수분특성(水分特性)에 관한 생리(生理)·생태학적(生態學的) 해석(解析(IV) - 몇 종(種)의 침엽수(針葉樹)에 있어서 Leaf Conductance와 Water Potential, 상대함수율(相對含水率), 팽압(膨壓)과의 관계(關係) -)

  • Han, Sang Sup;Jeon, Doo Sik
    • Journal of Korean Society of Forest Science
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    • v.63 no.1
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    • pp.28-34
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    • 1984
  • This study was to elucidate the relation between the water relations parameters obtained from P-V curves and stomatal closure. The results obtained are as follows: 1) The water potential at incipient plasmolysis obtained from P-V curves was similar to the water potential at critical stomatal closure. 2) The critical stomatal closure of sun leaves appear at -21 bar (-17 bar, shade leaves) in Pinus koraiensis, -20 bar in Pinus rigida, -22 bar in Pinus densiflora, and -24 bar in Larix leptolepis. On a relative water content basis, the critical stomatal closures of sun leaves appear at 85% (82%, shade leaves) in Pinus kordiensis, 77% in Pinus ragida, 85% in Pinus densiflora, and 70% in Larix leptolepis. 3) The incipient stomatal closures of sun leaves appear at -14 bar (-12 bar, shade leaves) in Pinus koraiensis, -10 bar in Pinus rigida, -15 bar in Pinus densiflora, and -6 bar in Larix leptolepis. On a relative water content basis, the incipient stomatal closures of sun leaves appear at 90% in Pinus koraiensis, 93% in Pinus rigida, 90% in Pinus densiflora, and 93% in Larix leptolepis. 4) The leaf conductance was increased by increase in volume-averaged turgor pressure was linearly increased by increase in relative water content.

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Water Relations Parameters of Rhododendron micranthum Turcz. from P-V Curves (P-V곡선에 의한 꼬리진달래(Rhododendron micranthum Turcz.)의 수분특성)

  • Kim, Nam-Young;Lee, Kyeong-Cheol;Han, Sang-Sub;Park, Wan-Geun
    • Korean Journal of Plant Resources
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    • v.23 no.4
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    • pp.374-378
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    • 2010
  • Determining plant moisture characteristics is an essential study not only for cultivation, but also for ex-situ conservation. In this study, employing pressure-volume curve we examined moisture characteristics of Rhododendron micranthum, known as rare plant, with the aim of its ex-situ conservation. Several individuals growing in Mt. Worak, Youngwol-gun Yeonha-ri and Bongwa-gun Seokpo-ri were selected for this study, from which we collected leaves. The original bulk osmotic pressure at maximum turgor(${{\Psi}_o}^{sat}$)was -1.5 MPa in those of Mt. Worak and Seokpo-ri, which is somewhat lower than that of Yeonha-ri(-1.2 MPa). It appeared that the osmotic pressure at incipient plasmolysis(${{\Psi}_o}^{tlp}$) of leaves collected in both Mt. Worak and Seokpo-ri were -1.29 MPa, and -1.26 MPa, respectively, which are lower than that of Yeonha-ri(-1.02MPa). Maximum bulk modulus of elasticity($E_{max}$) was 14.0 MPa, 8.67 MPa in leaves collected from both Seokpo-ri and Mt. Worak, respectively, those value of which were approximately 3 times higher than that of Yeonha-ri(4.00 MPa). The values of $RWC_{tlp}$(Relative water content at incipient plasmolysis) of leaves collected in three areas, were roughly 83%, suggesting that Rhododendron micranthum has relatively high capability of containing water. Our finding on moisture characteristics of Rhododendron micranthum is similar to those of other Rhododendron spp. We suggest that individuals growing in both Worak and Seokpo-ri, are preferable to those in Yeonha-ri for ex-situ transplantation since those individuals are found to have better drought resistance.

The Extrusion Characteristics in Hor Extrusion of $SiC_p/6061 Al$ Composite ($SiC_p/6061 Al$ 복합재료의 압출가공에 있어서 압출특성)

  • Jo, Hyeong-Ho
    • Korean Journal of Materials Research
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    • v.4 no.8
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    • pp.945-951
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    • 1994
  • In order to elucidate the extrusion characteristics of $SiC_{p}$/6061 Al composite, defomation resistance, $K_{w}$ was determined using the empirical formula suggested by Watanabe et al, and also extrusion pressure was measured using the extrusion press with a capacity of 350 ton. The $K_{w}$ which are propotional to extrudability, was increased with increasing volume fraction of reinforcement, $SiC_{p}$, but decreased with increasing the particle size. The peaks of maximum extrusion pressure in curves of extrusion force vs ram stroke were changed sharply with decreasing the particle size. The elevated extrustion temperature resulted in the decreased $K_{w}$ and extrusion pressure, but caused the surface tearing of extrusion composite bars. The results showed that extrudability of the composite billets is depend on the extrusion conditions as well as the characteristics of reinforcement, $SiC_{p}$.

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Effects of Mg on corrosion resistance of Al galvanically coupled to Fe (Fe와 galvanic couple된 알루미늄의 내식성에 미치는 마그네슘의 영향)

  • Hyun, Youngmin;Kim, Heesan
    • Corrosion Science and Technology
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    • v.12 no.1
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    • pp.40-49
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    • 2013
  • Effects of magnesium and pH on corrosion of aluminum galvanically coupled to iron have studied by using potentio- dynamic and static tests for polarization curves, Mott-Schottky test for analysis of semiconductor property, and GD-AES and XPS for film analysis. Pitting potential was sensitive to magnesium as an alloying element but not to pH, while passive current was sensitive to pH but not to magnesium. It was explained with, instead of point defect model (PDM), surface charge model describing that the ingression of chloride depends on the state of surface charge and passive film at film/solution interface is affected by pH. In addition, galvanic current of aluminum electrically coupled to iron was not affected by magnesium in pH 8.4, 0.2M citrate solution but was increased by magnesium at the solution of pH 9.1. The galvanic current at pH 9.1 increased with time at the initial stage and after the exposure of about 200 minute, decreased and stabilized. The behavior of the galvanic current was related with the concentration of magnesium at the surface. It agreed with the depletion of magnesium at the oxide surface by using glow discharge atomic emission spectroscopy (GD-AES). In addition, pitting potential of pure aluminum was reduced in neutral pH solution where chloride ion maybe are competitively adsorbed on pure aluminum. It was confirmed by the exponential decrease of pitting potential with log of [$Cl^-$] around 0.025 M of [$Cl^-$] and linear decrease of the pitting potential. From the above results, unlike magnesium, alloying elements with higher electron negativity, lowering isoelectric point (ISE), are recommended to be added to improve pitting corrosion resistance of aluminum and its alloys in neutral solutions as well as their galvanic corrosion resistance in weakly basic solutions.

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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    • v.16 no.6
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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.

Survival Analysis and Prognostic Factors for Colorectal Cancer Patients in Malaysia

  • Hassan, Muhammad Radzi Abu;Suan, Mohd Azri Mohd;Soelar, Shahrul Aiman;Mohammed, Noor Syahireen;Ismail, Ibtisam;Ahmad, Faizah
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.7
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    • pp.3575-3581
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    • 2016
  • Background: Cancer survival analysis is an essential indicator for effective early detection and improvements in cancer treatment. This study was undertaken to document colorectal cancer survival and associated prognostic factors in Malaysians. Materials and Methods: All data were retrieved from the National Cancer Patient Registry-Colorectal Cancer. Only cases with confirmed diagnosis through histology between the year 2008 and 2009 were included. Retrieved data include socio-demographic information, pathological features and treatment received. Survival curves were plotted using the Kaplan-Meier method. Univariate analysis of all variables was then made using the Log-rank test. All significant factors that influenced survival of patients were further analysed in a multivariate analysis using Cox' regression. Results: Total of 1,214 patients were included in the study. The overall 3- and 5-year survival rates were 59.1% and 48.7%, respectively. Patients with localized tumours had better prognosis compared to those with advanced stage cancer. In univariate analysis, staging at diagnosis (p<0.001), primary tumour size (p<0.001), involvement of lymph nodes (p<0.001) and treatment modalities (p=0.001) were found to be predictors of survival. None of the socio-demographic characteristics were found to exert any influence. In Cox regression analysis, staging at diagnosis (p<0.001), primary tumour size (p<0.001), involvement of lymph nodes (p<0.001) and treatment modalities (p<0.001) were determined as independent prognostic factors of survival after adjusted for age, gender and ethnicity. Conclusions: The overall survival rate for colorectal cancer patients in Malaysia is similar to those in other Asian countries, with staging at diagnosis, primary tumor size, involvement of lymph node and treatment modalities having significant effects. More efforts are needed to improve national survival rates in future.