• Title/Summary/Keyword: K-Plot

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A Kinetic Study on Michael-type Reactions of 1-(X-Substituted Phenyl)-2-propyn-1-ones with Amines: Effect of Amine Nature on Reactivity and Mechanism

  • Um, Ik-Hwan;Hwang, So-Jeong;Lee, Eun-Ju
    • Bulletin of the Korean Chemical Society
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    • v.29 no.4
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    • pp.767-771
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    • 2008
  • Second-order rate constants have been measured spectrophotometrically for the Michael-type reaction of 1-(Xsubstituted phenyl)-2-propyn-1-ones (2a-f) with amines in $H_2O$ at 25.0 ${\pm}$ 0.1 ${^{\circ}C}$. A linear Brønsted-type plot is obtained with ${\beta}_{nuc}$ = 0.25 ${\pm}$ 0.02, a typical $\beta_{nuc}$ value for reactions which proceed through a stepwise mechanism with attack of amine on the electrophilic center being the rate-determining step. Secondary alicyclic amines are found to be more reactive than isobasic primary amines. The Hammett plot for the reactions of 2a-f with morpholine is not linear, i.e., the substrate with a strong electron-donating group (e.g., 4-MeO) exhibits a negative deviation from the Hammett plot. However, the Yukawa-Tsuno plot for the same reactions exhibits an excellent linear correlation with ρ = 0.62 and r = 0.82. Thus, it has been proposed that the nonlinear Hammett plot is not due to a change in the ra te-determining step but due to ground-state stabilization through resonance interactions.

Changes of soil characteristics, rice growth and lodging traits by different fertilization and drainage system in paddy soil (논 토양에서 배수 및 시비조건에 따른 토양특성, 생육 및 도복 관련 형질의 변화)

  • Jeon, Weon-Tai;Park, Chang-Young;Park, Ki-Do;Cho, Young-Son;Lee, Jeom-Sig;Lee, Dong-Chang
    • Korean Journal of Soil Science and Fertilizer
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    • v.35 no.3
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    • pp.153-161
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    • 2002
  • The installation of subsurface drainage equipment is required for generalized use of paddy field and to improve soil productivity. The internal drainage of paddy field has improved root condition from the increasing of oxygen supply and removing noxious elements. This experiment was carried out to determine the effects of fertilization and drainage system on soil characteristic, growth and lodging trait of rice in paddy soil. A subsurface drainage system was installed a depth of 0.8m. Three fertilizer treatments were applied : 1) Conventional fertilized plot, 2) Controlled-release fertilized plot, 3) No-fertilized plot. In conventional plot, 110 kg N (as urea 46%), 45 kg P (as fused phosphate 20%) and 57 kg K (as potassium chloride 60%) per hectare fertilizers were applied. Controlled-release fertilizer was applied by 70% of N compared to the conventional plot. During the rice cropping, the water depth decrease was two times higher in subsurface drainage(SD) plot than non-drained(ND) plot. After harvesting of rice, the bulk density of sub-soil(10-20cm depth) was lower in SD plot than ND plot. After the experiment, the surface soil pH was high at SD plot but sub-soil was high at ND plot. Organic matter content was higher in all soil layer for SD plot than fro ND plot. Available $P_2O_5$ was not different between SD and ND plot for surface soil, but was high for SD plot for sub soil. The $NH_4{^+}-N$ content of soil, shoot dry matter, total nitrogen and $K_2O$ of rice plant were greater after panicle formation stage in SD plot. Total nitrogen content, $P_2O_5$ and $K_2O$ of rice root were high in SD plot after heading. Though the gravity center and 3rd internode length were greater, pulling force of rice root was higher in SD plot than ND plot. Rice yield in SD plot were low at conventional and controlled-release fertilized plot because of the greater field lodging, but yield in SD plot was high at no-fertilized plot. This study indicates that the fertilization level should be decrease on subsurface drainage system for rice cropping.

Three Dimensional CERES Plot in Generalized Linear Models (일반화선형모형에서의 3차원 CERES그림)

  • Kahng, Myung-Wook;Kim, Bu-Yong;Jeon, Jin-Young
    • The Korean Journal of Applied Statistics
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    • v.21 no.1
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    • pp.169-176
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    • 2008
  • We explore the structure and usefulness of three dimensional CERES plot as a basic tool for dealing with curvature as a function of the new predictors in generalized linear models. If predictors have nonlinear effects and there are nonlinear relationships among the predictors, the partial residual plot is not able to display the correct functional form of the predictors. Unlike this plots, the CERES plot can show the correct form. This is illustrated by simulated data.

Application of Abductive Rules: Detection of Plot Units (개연규칙의 활용: Plot Units의 발견)

  • Kim, Gon;Yang, Jae-Gun;Bae, Jae-Hak
    • Proceedings of the Korean Information Science Society Conference
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    • 2004.04b
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    • pp.652-654
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    • 2004
  • 개연규칙은 문장 구성성분들의 문장간 개연적 연결상황을 나타내고, 글의 인과성향이나 담화작용을 반영한다. Plot Units는 이야기를 형성하는 줄거리 또는 줄거리에 나오는 여러 사건을 하나로 구성하여 표현한다. 글을 읽고 Plot Units를 파악한다는 것은 그 글의 내용을 이해하고 있다는 것이다 본 논문에서는 이러한 Plot Units를 찾는 한 방법으로 개연규칙을 생각하였다. 개연규칙들을 Plot Units와 대응시켜 봄으로써. 개연규칙을 활용하여 글의 Piot Units를 발견할 수 있음을 확인하였다.

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Model assessment with residual plot in logistic regression (로지스틱회귀에서 잔차산점도를 이용한 모형평가)

  • Kahng, Myung Wook
    • Journal of the Korean Data and Information Science Society
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    • v.26 no.1
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    • pp.141-150
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    • 2015
  • Graphical paradigms for assessing the adequacy of models in logistic regression are discussed. The residual plot has been widely used as a graphical tool for evaluating the adequacy of the model. However, this approach works well only for linear models with constant variance, and the alternative approach, the marginal model plot, has its defects as well. We suggest a Chi-residual plot that overcomes the potential shortcomings of the marginal model plot.

Effects of Elevated $CO_2$ and Temperature on Seedling Emergence of Herbs in a Japanese Temperate Grassland

  • Lee, Jae-Seok;Takehisa Oikawa;Shigeru Mariko;Lee, Ho-Joon
    • The Korean Journal of Ecology
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    • v.23 no.6
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    • pp.423-429
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    • 2000
  • To understand the effects of elevated $CO_2$ concentration and temperature on seedling emergence of seven herbaceous species, the seedling emergence was monitored between November 1997 and May 1998 using a temperature gradient chamber and a $CO_2$-temperature gradient chamber. Experiment was conducted under current ambient condition (Control plot), 2$^{\circ}C$-warmed condition with ambient $CO_2$ (T2 Plot), 4$^{\circ}C$-warmed condition with ambient $CO_2$ (T4 plot). and 4$^{\circ}C$-warmed condition with 1.8 fold of ambient $CO_2$ (CT4 plot). Species tested in this study were Digitaria adscendens, Echinochloa crus-galli, Panicum bisulcatum, Setaria viridis. Oenothera biennis, Andropogon virginicus, and Imperata cylindrica. Each species often dominates in the herbaceous stage of secondary succession in Japan. The mean seedling emergence times for all species were significantly increased to 23.6 and 32.2 d in the T2 and T4 plot compared to the Control plot, respectively. The most sensitive and insensitive species in seedling emergence time in T2 plot were O. biennis and D. adscendens, respectivel.y, and those in the T4 and CT4 plot were I. cylindrica and D. adscendens, E. crus-galli and A. virginicus, respectively. All experimental species showed no significant difference in the seedling emergence rate between treatments except for O. biennis and I. cylindrica. O. biennis showed a great decrease in the seedling emergence rate from 83.3% in the Control plot to 38.0%, 14.7%, and 29.3% in the T2, T4, and CT4 plot, respectively. Elevated $CO_2$ had very little effect on the seedling emergence. From these observations, it is expected that increased temperature would greatly advance the vegetative recovery time after disturbance through the advancement of seedling emergence time.

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The Analysis of Productivity of Oak Stand following to Site Quality and Crown Class (I) (입지(立地)와 수형급(樹型級)에 따른 참나무임분(林分)의 생산력(生産力) 분석(分析) (I))

  • Kim, Chi Moon;Kwon, Ki Won;Song, Ho Kyong;Moon, Heung Kyu;Park, Hong Joon
    • Korean Journal of Agricultural Science
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    • v.10 no.1
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    • pp.9-21
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    • 1983
  • The structures of oak stands were studied in relation to their productivity. Three plots classified by the site quality following to altitude, were selected on the oak stand located at Naryongri Eunsanmyun Buyeogun. The site qualities of the stand studied were generally estimated to be moderate in respect to some soil physical and chemical properties. Quercus variabilis was dominant species in the vegetation composition of the stand studied. The crown densities of the stand were varied from 65.4% in plot I to 78.2% in plot III and the parts, occupied with oak trees, ranged from 44.4% in plot I to 65.9% in plot III in the density. In the contrast to crown density, the growing stocks of oak trees ranged from $3.937m^3$ in plot I (73.4% of plot total) to $2.075m^3$ in plot III (84.3% of plot total). The occupied ratios, measured by crown class, exhibited dissimilarity between crown projection area and volume, and also the ratios brought into different patterns by plot. Highly significant correlations were proved between crown projection areas and volumes of individual oak trees by plot, but not proved in the relations by crown class. The cumulative growth, current annual increment and mean annual increment displayed various patterns by plot and by crown class in the heights, D. B. H. s and volumes of oak trees. The maximum values of current annual increment of height were generally recorded in 10 to 20 years, earlier than those of D. B. H. The mean annual increment of height, D. B. H. and volume maintained similar levels after about 10 years and fluctuated irregularly. The crown projection area and volume following to thinning decreased in the order of the thinning methods of grade A < grade B < crown thinning$90m^3/ha$ in about 40 years in the productivity of volume of the oak stand studied.

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

  • Jin, AHee Sung;Joon Huh
    • The Korean Journal of Ecology
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    • v.9 no.3
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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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Kinetic Study on Aminolysis of Y-Substituted-Phenyl X-Substituted-Benzoates: Effects of Substituents X and Y on Reactivity and Reaction Mechanism

  • Jeon, Seong Hoon;Kim, Hyun Soo;Han, Young Joon;Kim, Min-Young;Um, Ik-Hwan
    • Bulletin of the Korean Chemical Society
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    • v.35 no.2
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    • pp.471-476
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    • 2014
  • A kinetic study on aminolysis of 2-chloro-4-nitrophenyl X-substituted-benzoates (2a-k) in 80 mol % $H_2O/_20mol%$ DMSO at $25.0^{\circ}C$ is reported. The Br${\emptyset}$nsted-type plot for the reactions of 2-chloro-4-nitrophenyl benzoate (2g) with a series of cyclic secondary amines curves downward (e.g., ${\beta}_1=0.25$, ${\beta}_2=0.85$ and $pK_a^o=10.3$), which is typical of reactions reported to proceed through a stepwise mechanism with a change in ratedetermining step (RDS). The Hammett plot for the reactions of 2a-k with piperidine consists of two intersecting straight lines, while the corresponding Yukawa-Tsuno plot exhibits an excellent linear correlation with ${\rho}_X=1.15$ and r = 0.59. Thus, it has been concluded that the nonlinear Hammett plot is not due to a change in RDS but is caused by stabilization of substrates through resonance interactions between the electron-donating substituent and the C=O bond. Substrates possessing a substituent at the 2-position of the leaving aryloxide deviate negatively from the curved Br${\emptyset}$nsted-type plot for the reactions of Y-substituted-phenyl benzoates (3a-i), implying that the steric hindrance exerted by the substituent at the 2-position is an important factor which governs the reactivity of Y-substituted-phenyl benzoates.

Graphical Methods for Evaluating the Effect of Outliers in Univariate and Bivariate Data (일변량 및 이변량 자료에 대하여 특이값의 영향을 평가하기 위한 그래픽 방법)

  • Jang, Dae-Heung
    • Proceedings of the Korean Society for Quality Management Conference
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    • 2006.11a
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    • pp.221-226
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    • 2006
  • We usually use two techniques(influence function and local influence) for detecting outliers. But, we cannot use these difficult techniques in elementary industrial statistics course for college students. We can use some simple graphical methods(box plot, dandelion seed plot, influence graph and cumulative deletion plot) for univariate and bivariate outlier detection and outlier effect in elementary industrial statistics course for college students.

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