• East Asian mathematical journal
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• 제34권3호
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• pp.287-293
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• 2018

We investigate the averaging value of a random sampling ${\zeta}(1/2+iX_t)$ of the Riemann zeta function on the critical line. Our result is that if $X_t$ is an increasing random sampling with Poisson distribution, then $${\mathbb{E}}{\zeta}(1/2+iX_t)=O({\sqrt{\;log\;t}}$$, for all sufficiently large t in ${\mathbb{R}}$.

• 대한수학회논문집
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• 제20권2호
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• pp.247-257
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• 2005

In this paper we calculate two special types of multiple zeta values, $\zeta(\{4\iota+2\}_n)\;and\;\zeta(\{4\iota\}_n)$ using the primitive roots of unity, which may be simpler and easier.

• 대한수학회지
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• 제37권6호
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• pp.991-1005
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• 2000

We consider a zeta function of the classical dynamics in the exterior of several convex bodies. The main result is that the poles of the zeta function cannot converge to the line of absolute convergence if the abscissa of absolute convergence of the zeta function is positive.

• Journal of applied mathematics & informatics
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• 제9권2호
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• pp.787-791
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• 2002

The aim of this paper is to study the condition of $\zeta$-convexity. We will give examples of $\zeta$-functions in filbert spaces and in non-UMD-spaces.

• East Asian mathematical journal
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• 제16권2호
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• pp.233-237
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• 2000

Since the time of Euler, there have been many proofs giving the value of $\zeta(2n)$. We also give an evaluation of $\zeta(2n)$ by analyzing the generating function of Bernoulli numbers.

• 상하수도학회지
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• 제19권4호
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• pp.437-445
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• 2005

Zeta potential is a key parameter of double layer repulsion for individual particles and can usually be used to interpret the trend of coagulation efficiency. This study focused on the measurement of zeta potential of algae and clay under various experimental conditions including water characteristics (pure water, stream water, reservoir water) and coagulant dose (10~50 mg/L). Results showed that the variation of zeta potential was highly sensitive depending on the water characteristics and coagulation conditions. Zeta potential of two genera of algae (anabaena sp. and microcystis sp.) were changed highly with coagulant dosage, especially. On the basis of trajectory analysis, bubble-floc collision efficiency simulated in terms of zeta potential was fitted well with removal efficiency of chlorophyll-a from algae particles. It was found that the control of zeta potential was important for effective removal of algae particles.

• 한국분무공학회지
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• 제8권1호
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• pp.16-22
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• 2003

Zeta potential measurements of colloid particles suspended in a liquid are performed by a Zeta Meter developed. There are many applications of colloid stability in spray technology, paints, wastewater treatment, and pharmaceuticalse. Zeta potentials of charged particles are obtained by measuring the electrophoretic velocities of the particles using video enhanced microscopy and image analysis program. The values of zeta potential of polystyrene latex(PSL), $silica(SiO_2)$M, polyvinylidence difluoride(PVDF), silicon nitride, and alumina particles in deionized (DI) water were measured to be -40.5, -31.9, -25.2, -15.1 and -10.1mV, respectively. The particles having high zeta potential less than -20 mV are stable in DI water, because the double layers of them have strong repulsive forces mutually, and the particles having low zeta potential over -20mV are unstable due to Van Der Waals forces. Silica(>20nm), PSL, aluminum and PVDF particles were found to be stable that would remain separate and well disperse, while silicon nitride and alumina particles were found to be unstable that would gradually agglomerate in DI water.

• 상하수도학회지
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• 제14권4호
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• pp.343-349
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• 2000

Techniques such as dissolved air flotation and electroflotation, which utilize micro bubbles, are increasingly used for water and wastewater treatment. Most studies have concentrated on particle characteristics. Pretreatments that manipulate particle size and zeta potential were considered important. A recent study, which modeled the collision mechanism between micro bubbles and particles in dissolved air flotation, suggested bubble characteristics should also be important. Hydrogen micro bubbles were generated electrolytically and their zeta potentials measured under various conditions using a novel electrophoresis method. Effects of several parameters were investigated. Bubble zeta potentials were found to be pH dependent, and to have a negative value around neutral pH, becoming zero or positive at lower pH. The pH at zero zeta potential was 5.0 under study conditions. Using artificial solution and tap water, at fixed pH, bubble zeta potentials varied with solution composition. Zeta potentia]s of bubbles were affected by the types of cations and anions in solution but not by the voltage applied. These findings will help improve efficiencies of particle removal processes that utilize micro bubbles. As bubble zeta potential varies with solution composition, it needs to be measured for each composition to understand those effects, which increase removal efficiency.

• Korean Chemical Engineering Research
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• 제53권6호
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• pp.831-835
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• 2015

본 연구에서는 바이오매스 유래 생리활성물질인 (+)-dihydromyricetin을 정제하기 위한 분별침전공정에서 분별침전용액의 제타전위가 분별침전 양상(순도, 수율, 침전물 형태와 크기)에 미치는 영향을 조사하였다. 제타전위 조절을 위한 실리카-알루미나의 첨가량(반응액 부피당 표면적) $100mm^{-1}$에서 가장 높은 수율을 얻을 수 있었다. 실리카-알루미나의 제타전위가 양(+)의 값으로 증가할수록 (+)-dihydromyricetin 수율과 침전물의 크기는 증가하였다. 가장 큰 제타전위 값(+4.99 mV)을 가진 실리카를 이용한 분별침전의 경우에는 가장 작은 제타전위 값(-19.00 mV)을 가진 알루미나를 이용한 분별침전의 경우보다 2배 이상 높은 수율을 얻을 수 있었다. 또한 분별침전 과정에서 제타전위 절대값이 증가할수록 (+)-dihydromyricetin 수율과 침전물의 크기는 감소하여 제타전위 절대값에 반비례함을 알 수 있었다. 반면 표면적증가물질 실리카-알루미나의 제타전위 변화에도 (+)-dihydromyricetin 순도는 거의 변화가 없었다.

• The Korean Journal of Physiology and Pharmacology
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• 제4권6호
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• pp.487-496
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• 2000

Insulin stimulates glucose transport in muscle and fat cells by promoting the translocation of glucose transporter (GLUT4) to the cell surface. Phosphatidylinositide 3-kinase (PI3-kinase) has been implicated in this process. However, the involvement of protein kinase B (PKB)/Akt and $PKC-{\zeta}$, those are known as the downstream target of PI3-kinase in regulation of GLUT4 translocation, is not known yet. An interesting possibility is that these protein kinases phosphorylate GLUT4 directly in this process. In the present study, $PKB-{\alpha}$ and $PKC-{\zeta}$ were added exogenously to GLUT4-containing vesicles purified from low density microsome (LDM) of the rat adipocytes by immunoadsorption and immunoprecipitation for direct phosphorylation of GLUT4. Interestingly GLUT4 was phosphorylated by $PKC-{\zeta}$ and its phosphorylation was increased in insulin stimulated state but GLUT4 was not phosphorylated by $PKB-{\alpha}.$ However, the GST-fusion proteins, GLUT4 C-terminal cytoplasmic domain (GLUT4C) and the entire major GLUT4 cytoplasmic domain corresponding to N-terminus, central loop and C-terminus in tandem (GLUT4NLC) were phosphorylated by both $PKB-{\alpha}$ and $PKC-{\zeta}.$ The immunoblots of $PKC-{\zeta}$ and $PKB-{\alpha}$ antibodies with GLUT4-containing vesicles preparation showed that $PKC-{\zeta}$ was co-localized with the vesicles but not $PKB-{\alpha}.$ From the above results, it is clear that $PKC-{\zeta}$ interacts with GLUT4-containing vesicles and it phosphorylates GLUT4 protein directly but $PKB-{\alpha}$ does not interact with GLUT4, suggesting that insulin-elicited signals that pass through PI3-kinase subsequently diverge into two independent pathways, an Akt pathway and a $PKC-{\zeta}$ pathway, and that later pathway contributes, at least in part, insulin stimulation of GLUT4 translocation in adipocytes via a direct GLUT4 phosphorylation.