• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.4
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• pp.709-714
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• 2006

The propose of this study was to investigate the feasibility of using waste lime core to remove phosphorus from wastewater in continuous flow reaction. The phosphorus was found to be removed from municipal wastewater by hydroxyapatite crystallization and precipation. Waste lime core size 1, 2 showed phosphorus removal rate of about 90% during early 11 hrs of run time. In addition, breakpoint time was decreased by increased inflow rate regardless of waste lime core size.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2357-2360
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• 2010

Kinetic studies on the pyridinolysis of aryl dithiocyclopentanecarboxyaltes 2 were carried out at $60.0^{\circ}C$ in acetonitrile. In the aminolysis of 2, the $\beta_X$ values were 0.5 - 0.8 with anilines, and there was no breakpoint. However, in the pyridinolysis of 2, biphasic Bronsted plots were obtained, with a change in slope from a large value ($\beta_X{\cong}0.7$) to a small value ($\beta_X{\cong}0.4$) at $pK_{a}^0$ = 5.2. This was attributed to a change in the rate-limiting step from breakdown to the formation of a zwitterionic tetrahedral intermediate, $T^{\pm}$, in the reaction path, with an increase in the basicity of the pyridine nucleophile. An obvious change in the cross-interaction constant ${\rho}_{XZ}$ from a large positive ($\rho_{XZ}$ = +1.02) value to a small negative value (${\rho}_{XZ}$ = -0.17) supports the proposed mechanistic change.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4179-4184
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• 2011

The nucleophilic substitution reactions of bis(2,6-dimethylphenyl) chlorophosphate (5), containing the four ortho-methyl substituents, with X-pyridines are investigated kinetically in MeCN at $65.0^{\circ}C$. The free energy correlations for substituent X variations in the nucleophiles exhibit biphasic concave upwards with a breakpoint at a X = 3-Cl. Unusual positive ${\rho}_X$ (= +5.40) and negative ${\beta}_X$ (= -0.83) values are obtained with the weakly basic pyridines. The pyridinolysis rate of 5 is hundreds times slower compared to that of bis(phenyl) chlorophosphate because of the steric hindrance of the four ortho-methyl substituents in the two phenyl rings. Ion-pair mechanism is proposed and positive ${\rho}_X$ and negative ${\beta}_X$ values are substantiated by an imbalance of the transition state.

• Journal of Korean Society of Transportation
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• v.14 no.2
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• pp.7-29
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• 1996

Traffic flow characteristics is analysed on eight multi-lane roads which are unsignalized in urban areas. Data of traffic flow rates by classification and average speed were gathered every ten minutes interval for twenty-four hours. Machine (NC-90A) was used to acquire the field data. The major purpose of this study is to build up speed-density models on urban arterial roads. Five different kinds of models were tested. Those models are Greenshields' model, Greenberg's model, modified Greenberg's model, Underwood's model and Drake's model. The modified Greenberg's model fits best at six points and the Greenshield's model fits best two points out of eight points. The breakpoint(Kb) of modified Greenberg's model is between 10 and 32 pcphpl. Capacity drawn from speed-volume relationships were appeared to be arround 2,000 and 2,200 pcphpl at the Hannam Bridge and the Hannam Overpass and 1,100 and 1,700 pcphpl at Namsan Tunnel(No1) and the beginning point of Gyeong-Bu Expressway.

• The Journal of Korean Association of Computer Education
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• v.10 no.6
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• pp.91-105
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• 2007

The Hough transform is a popular method for ellipse detection from image. But the method wastes time and memory space severely. And the existing methods for elliptical arc segmentation are very sensitive to noise or detect improper breakpoints. In this paper a fast method is proposed for the segmentation and detection of elliptical arcs from digital curve using its area. Experimental results show that the proposed method segments and detects elliptical arcs from noisy curves and the average of the distance errors between the fitted arc and given curve is within a threshold.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.11
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• pp.1044-1049
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• 2015

This paper proposes an autonomous navigation system of mobile robots for indoor corridor environment. The system uses a laser scanner but does not use reflectors. The laser scanner measures the distance between robot and structures such as wall, pillar, and fixtures. Adaptive breakpoint detector and modified IEPF (iterative endpoint fit) are developed to find mark points from the distance data. The robot path for corridor is then generated using the angle histogram of the mark points. The experimental results are finally presented to show the effectiveness of the proposed method.

• Water for future
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• v.23 no.3
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• pp.363-371
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• 1990

Foundational experiments are conducted to examine the applicability of redox control in brak-point chlorination of ammonia on drinking water purification. Through the research, the behauial affects by ph and temperature to a chloromine forming reactions are evaluated. The possibility of redox control in breakpoint chlorination is recoguized by drawing up the titration curve in terms of redox potential and $C{\ell}_2$/N ratios.

• Preventive Nutrition and Food Science
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• v.3 no.2
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• pp.123-127
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• 1998

Fixed-bed adsorption was adapted to separate phenolic acids from diluted phenolic solution. Break-through curve was obtained by nonlinear curve fitting method, and breakpoint, saturation time, and mass transfer coeffi-cient were calculated . Break point and saturation time were reached slower with $\rho$-coumaric acid than ferulic acid .The p-coumaric acid, having small molecular weight, is suposedly traveled longer pathway in characoal than ferulic acid. Fixed-bed adsorption iwht gallic acid having more hydroxyl functional group than other phenolic acids showed break point arrival and the largest saturation time. This fact means that there was bigger electrostatic affinity between gallic acid and charcoal than between other phenolic acids and charcoal.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.3
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• pp.396-402
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• 2005

Three experiments were conducted to determine the effects of dietary arginine concentrations on plasma free amino acid (PAA) concentrations in rainbow trout, Oncorhynchus mykiss (Walbaum). The first experiment was conducted to determine appropriate post-prandial and food deprivation sampling times in dorsal aorta cannulated rainbow trout averaging 519${\pm}$9.5 g (mean${\pm}$SD) at $16^{\circ}C$. Blood samples were taken at 0, 2, 3, 4, 5, 6 and 24 h after feeding (0 and 24 h blood samples were taken from the same group of fish). PAA concentrations increased by 2 h post-feeding and the concentration of all essential amino acids except histidine peaked at 5 h and returned to 0 time values by 24 h. In the second experiment dorsal aorta cannulated rainbow trout averaging 528${\pm}$11.3 g (mean${\pm}$SD) were divided into 6 groups of 4 fish to study the effect of dietary arginine levels on PAA. After 24 h food deprivation, each group of fish was fed one of six L-amino acid diets containing graded levels of arginine (0.48, 1.08, 1.38, 1.68, 1.98 or 2.58%) by intubation. Blood samples were taken at 0, 5 and 24 h after feeding. Post-prandial (5 h after feeding) plasma-free arginine concentrations (PParg) showed a breakpoint at 1.03% arginine in the diet and post-absorptive (24 h after feeding) plasma free-arginine concentrations (PAarg) showed a breakpoint at 1.38% arginine. PAarg increased linearly from fish fed diets containing arginine between 0.48% and 1.38%, and the concentrations remained constant from fish fed diets containing arginine at or above 1.38%, but were all below PParg at all time points. Results of the third experiment confirm the results that PParg concentrations from fish fed arginine deficient diets were higher than PAarg (0 or 24 h values). Thus, in contrast to mammals and birds, the PParg when arginine is present in the diet as the most limiting amino acid such that it severely limits growth, increases in plasma rather than decreases.

• Korean Journal of Clinical Laboratory Science
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• v.41 no.1
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• pp.6-10
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• 2009

Ring chromosome occurs when both telomeres of a chromosome are lost and the remaining portion of the chromosome circularizes to re-establish chromosome stability. This abnormal structure shows mitotic instability unlike the normal chromosomes, causing problems during mitosis. Here, we report one case of "chromosome 4 ring syndrome" on a 6-month-old male patient with growth retardation. Ring chromosome, monosomy, dicentric chromosome were shown by conventional chromosome analysis using peripheral blood. Peripheral blood was used and incubated for 72 hours for chromosome analysis. 3 probes (LSI WHS SpectrumOrange/CEP 4 SpectrumGreen, 4p subtelomere probe, 4q subtelomere probe) were used to detect the origin and breakpoint of ring chromosome 4 by FISH (fluorescense in situ hybridization) technique.