Wyniki wyszukiwania - BazTech

1

Gas chromatographic determination of phenol in fish tissues as a phenyl acetate derivative following solvent extraction of acidified samples

Kim H., Kim Y., Park S., Lee J., Choi J.

Acta Chromatographica

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2020

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Vol. 32, no. 1

64--67

EN

This study aimed to develop a chromatographic method to quantitatively determine phenol in fish tissues. This method involves solvent extraction of acidified samples, followed by derivatization to phenyl acetate and analysis with gas chromatography coupled with mass spectrometry (GC–MS). Phenol in a representative tissue sample (belly, gill, or renal tubules), which was homogenized with 2 N sulfuric acid, was extracted with ethyl acetate and derivatized to phenyl acetate using acetic anhydride and K2CO3 in water. An n-butyl acetate extract was injected into the GC–MS. The linearity (r2) of the calibration curve was greater than 0.996. The analytical repeatability, which is expressed as the relative standard deviation, was less than 6.14%, and the recovery was greater than 96.3%. The method detection limit and the limit of quantitation were 8.0 μg/kg and 26 μg/kg, respectively. The proposed method is also applicable to the analysis of other biological tissues for phenol and its analogs, such as pentachlorophenol.

2

Effect of natural organic matter on adsorption of ionic and non-ionic pharmaceuticals to granular activated carbon

Oh H., Urase T., Simazaki D., Kim H.

Environment Protection Engineering

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2013

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Vol. 39, nr 4

15--28

EN

Adsorption of clofibric acid (CA) and propyphenazone (PPZ) to virgin granular activated carbon (GAC) and preloaded GAC was evaluated in the absence or presence of natural organic matter (NOM). In spite of lower log K ow, PPZ showed higher selectivity to GAC than CA, which has a carboxylic group. Adsorption competition between CA and PPZ in binary solutes system decreased the amount of individual compound adsorbed to GAC. Adsorption isotherm data obtained in the presence of NOM showed that NOM in bulk solution or preloaded on GAC could significantly reduce the amounts of CA and PPZ adsorbed to GAC.

3

Stability of impulsive Hopfield neural networks with Markovian switching and time-varying delays

Raja R., Sakthivel R., Anthoni S. M., Kim H.

International Journal of Applied Mathematics and Computer Science

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2011

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Vol. 21, no 1

127-135

EN

The paper is concerned with stability analysis for a class of impulsive Hopfield neural networks with Markovian jumping parameters and time-varying delays. The jumping parameters considered here are generated from a continuous-time discrete-state homogenous Markov process. By employing a Lyapunov functional approach, new delay-dependent stochastic stability criteria are obtained in terms of linear matrix inequalities (LMIs). The proposed criteria can be easily checked by using some standard numerical packages such as theMatlab LMI Toolbox. A numerical example is provided to show that the proposed results significantly improve the allowable upper bounds of delays over some results existing in the literature.

4

Collision Scenario-based Cognitive Performance Assessment for Marine Officers

Kim H., Kim H. J., Hong S.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2010

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Vol. 4, no. 1

73--77

EN

The overall aim of this paper is to determine a fatigue factor that can be applied to human performance data as a part of a software program that calculates total cognitive performance. This program enables us to establish the levels of cognitive performance in a group of marine pilots in order to test a decision-making task based on radar information. This paper addresses one of the factors that may contribute to the determination of various fatigue factors: the effects of different work patterns on the cognitive performance of a marine pilot.

5

A study on the development of a new grinding processes for high-lead ball screw nuts

Choi Ch., Ha Y., Kim H., Lee C.

Journal of Machine Engineering

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2010

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Vol. 10, No. 1

50--57

EN

This paper proposes a method that machines the race of high-lead ball screw nuts, which is difficult to machine using the existing geometrical machining method, without any interferences and changes in its load rating in order to perform the high-speed in ball screws. This study calculates the inclination angle of the axis of the grinding stone for avoiding the contact of the axis to the inner diamete of the nut and determines the shape of the grinding stone through changing the inclination angle and dressing curvature determined in a dressing device Then, the grinding condition will be determined by measuring the shape meter of the screw race for solving the problem. Also, the surface roughness of the grinded surface was measured using a surface roughness tester, and check with applying a grinding process of product not being high-lead ball screw.

6

On BG-algebras

Kim C., Kim H.

Demonstratio Mathematica

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2008

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Vol. 41, nr 3

497-505

EN

In this paper we introduce the notion of BG-algebras which is a generalization of BG-algebras. We construct a BG-algebra from a non-empty set, which is non-group-derived. Moreover, using the notion of normal subalgebra, we obtain several isomorphism theorems of BG-algebra and related properties.

7

Another axiomatization of B-algebras

Kim C., Kim H.

Demonstratio Mathematica

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2008

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Vol. 41, nr 2

259-262

EN

In this paper we introduce the notion of a BA-algebra, and show that the class of BA-algebras is equivalent to the class of B-algebras.

8

Porings and poring algebras

Jun Y., Kim H., Neggers J.

Demonstratio Mathematica

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2006

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Vol. 39, nr 2

267-276

EN

In this paper we define an algebra of type (2,2,0) associated with posets called a poring and we study several properties of porings and the linear algebras having such porings as their bases. In particular, we show that if (P; *, .) is a standard poring then the distributive law (x . y) * z = (x * z) . (y * z) holds iff the poset P (or the poset X) is (C2 +1)-free.

9

The Effect of Stress Distribution on Texture Evolution of Cu Damascene During Annealing

Cho J-Y., Lee H-J., Kim H., Szpunar J. A.

Archives of Metallurgy and Materials

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2005

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Vol. 50, iss. 1

261-266

EN

Textural changes of Cu interconnect having dierent line width was investigated after annealing. Texture was measured using XRD (x-ray diraction) and the surface texture was investigated using EBSD (electron backscattered diraction) techniques. To analyze a relationship between the stress distribution and textural evolution observed in the samples, the stresses were calculated for the dierent line width at 200C using FEM (finite element modeling) along the width and depth of the line. In this investigation, it was found that the inhomogeneity of stress distribution in Cu interconnects is an important factor necessary for understanding textural transformation during annealing. Textural evolution in damascene interconnects lines after annealing is discussed, based on the state of stress in Cu electrodeposits.

PL

Zmiana tekstury w elektronicznych połączeniach miedzianych o różnej szerokości była badana po wyżarzaniu. Textura była mierzona przy użyciu dyfrakcji rentgenowskiej, a tekstura na powierzchni metodą EBSD. Związek pomiędzy rozkładem naprężeń a obserwowaną ewolucją tekstury w próbkach był analizowany metodą elementów skończonych na drodze obliczeń naprężeń w połączeniach o różnej szerokości, w temperaturze 200C. Obliczenia wykazały, że niejednorodność rozkładu naprężeń w miedzianych połączeniach elektronicznych jest niezbędnym czynnikiem do zrozumienia transformacji tekstury podczas wyżarzania. Ewolucja tekstury w damascenskich połączeniach miedzianych obwodów elektrycznych po wyżarzaniu jest rozważana w odniesieniu do stanu naprężeń w elektrolitycznie osadzonej miedzi.