• Journal of the Korean Chemical Society
• /
• v.6 no.2
• /
• pp.113-116
• /
• 1962

In this study we have measured the activity coefficients of NaCl in solution by E.M.F. method, depending upon MacInnes' equation at 25 dog. The cell (electrodes) is same as MacInnes' except the cock which was designed by ourselves as figure 1.Additionally, we have calculated the hydration number of NaCl from the activity coefficients using Robinson's equation and ionic hydration number according to our new formula $\frac{n_M{^+}+0.8}{n_A{^-}-0.1}=n_{MA}$, which was mentioned our former thesis.We also have calculated the hydration number of some salts from the ionic hydration number using upper formula and have got reasonable series match with other's value.As the results of our studying, we conclude it as follow;1) Liquid junction potential depend only on the bulk concentration of the both solution.2) The formula $\frac{n_M{^+}+0.8}{{n_A{^-}}-0.1}=n_{MA}$ is reasonable one in deducing to ionic hydration number.3) From upper relation, we can calculate the hydration number of unknown salts from it's ionic hydration numbers.

• Kyungpook Mathematical Journal
• /
• v.59 no.3
• /
• pp.363-375
• /
• 2019

Let G = (V, E) be a simple graph with p vertices and q edges. A subset S of V (G) is called a strong (weak) efficient dominating set of G if for every $v{\in}V(G)$ we have ${\mid}N_s[v]{\cap}S{\mid}=1$ (resp. ${\mid}N_w[v]{\cap}S{\mid}=1$), where $N_s(v)=\{u{\in}V(G):uv{\in}E(G),\;deg(u){\geq}deg(v)\}$. The minimum cardinality of a strong (weak) efficient dominating set of G is called the strong (weak) efficient domination number of G and is denoted by ${\gamma}_{se}(G)$ (${\gamma}_{we}(G)$). A graph G is strong efficient if there exists a strong efficient dominating set of G. In this paper, some cycle and star related Nordhaus-Gaddum type relations on strong efficient dominating sets and the number of strong efficient dominating sets are studied.

• The korean journal of orthodontics
• /
• v.24 no.1 s.44
• /
• pp.181-192
• /
• 1994

The effect of topical application on the number of S. mutans was tested in a group of 44 orthodontic patients (mean age, 12Y 3M). They were divided into 5 groups according to the method using NaF and $SnF_2$. The number of S. mutans CFU were counted in stimulated saliva of each subject at baseline, and after one, two, three, and eight weeks. The following results were obtained. 1. In NaF rinsing group, and NaF topical application and NaF rinsing group, the number of S. mutans per ml saliva was not significantly changed. 2. In $SnF_2$ topical application group, and $SnF_2$ topical and NaF rinsing group, the number of S. mutans per ml saliva was significantly reduced. 3. After 8 weeks, there were no significant reduction of the number of S. mutans in comparison with baseline.

• Journal of Food Hygiene and Safety
• /
• v.31 no.3
• /
• pp.216-221
• /
• 2016

This study was performed to evaluate the bactericidal efficacy of a fumigation disinfectant containing 35% paraformaldehyde against Salmonella Typhimurium (S. Typhimurium). In this study, the efficacy test of a fumigant against S. Typhimurium was carried out according to French standard NF T 72-281. The S. Typhimurium working culture suspension number (N value), all bacteria numbers on the carriers exposed to the fumigant (n1, n2, and n3), the number of bacterial suspensions by the pour plate method (N1), the number of bacterial suspensions by the filter membrane method (N2), and the mean number of bacteria recovered on the control carriers (T value), were obtained from the preliminary test. In addition, the reduction number of S. Typhimurium exposed to the fumigant (d value) was calculated using the T value, the mean number of bacteria in the recovery solution (n'1) and the mean number of bacteria on carriers plated in agar (n'2). The N value was $5.5{\times}10^8$ colony forming units (CFU)/mL, and n1, n2, and n3 were higher than 0.5N1, 0.5N2 and 0.5N1, respectively. Additionally, the T value was $3.5{\times}10^6CFU/carrier$. In terms of the bactericidal effect of the fumigant, the d value was 5.25. According to the French standard for fumigants, the d value for an effective bactericidal fumigant should be greater than 5. The results indicated that the fumigant containing 35% paraformaldehyde had an efficient bactericidal activity against S. Typhimurium, and, therefore, can be used to disinfect food materials and kitchen appliances contaminated with foodborne bacteria.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.17 no.11
• /
• pp.990-997
• /
• 2005

The stratified effect was investigated with three different types of diffuser shape in a thermal storage tank with variation of diffuser diameter, velocity, Froude number etc. Its effect was estimated by the degree of stratification. No matter of diffuser diameter and shape, the degree of stratification was the best as the Froude number gets closer to 1. In the case of a curved diffuser, when its diameter is a quarter of tank diameter and ejection velocity in a diffuser is approximately 0.2 m/s, the Froude number was almost 1. In the case of a flatted diffuser, when ejection velocity was 0.05 m/s, the Froude number was 1.5. Both cases which Froude number were nearer 1, showed the good degree of stratification.

• Journal of Korean Port Research
• /
• v.11 no.2
• /
• pp.145-156
• /
• 1997

The purpose in this study is development of model for the Container Terminals of Pusan Port, First of all, Quantitive and Qualititve factors are characterized which effects on Physical Distribution System in Container Terminals. The System Dynamics method is used to develope the model by using these factor. This model is able to present the timinig of investment in Container Terminals of Pusan Port. Six models are showed by change of parameters in System Dynamics, in this paper. In the model, Five feedback loop were found. Loop 1 : Number of Liners$\rightarrow$Number of Congested ships$\rightarrow$Port's Charges$\rightarrow$Export & Import Cargo Volumes$\rightarrow$Number of Liners$\rightarrow$The will to investment of government$\rightarrow$Length of berth→Number of Liners. Negative loop was acquired. Loop 2 : Port's Charge$\rightarrow$Economic of Port$\rightarrow$The will to Private management$\rightarrow$Efficiency for Port's Operation$\rightarrow$Port's Charges. Positive loop was acquired. Loop 3 : Number of Congested ships$\rightarrow$Planning for future development$\rightarrow$Information Service$\rightarrow$Support service for port's user$\rightarrow$Number of Congested ships. Negative loop was acquired. Loop 4 : Number of Congested ships$\rightarrow$Planning for future development$\rightarrow$Extent of stacking area$\rightarrow$Number of handling equipmint$\rightarrow$Number of Congested ships. Negative loop was acquired. Loop 5 : Export & Import Cargo Volumes$\rightarrow$Number of Liners$\rightarrow$Econmic of Port$\rightarrow$Support service for port's user$\rightarrow$Export & Import Cargo Volumes. Positive loop was acquired. System's level variables were selected as followings ; Number of Liners, Number of Congested ships, Export & Import Carge Volumes, Length of berth, and Port's Charges. As result of simmulation of model, fluctuation of respective year was found in level variables. This fluctuation can be used properly to present timing of investment.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.31 no.3
• /
• pp.1-11
• /
• 2018

Objectives : The purpose of this study is to analyze the correlation between fine dust(PM10.5, PM2.5) and the number of acute/chronic sinusitis patients. Methods : A simple regression analysis was performed based on the concentration of PM10 and PM2.5 as independent variables and the number of acute/chronic sinusitis patients as dependent variables. Results : As a result of simple regression analysis, if PM10 increases by $1{\mu}g/m^3$, the number of acute sinusitis patients increases by 7,000.291(P<.001, 95%CI :4,951.983-9,048.600). If PM2.5 increases by $1{\mu}g/m^3$, the number of acute sinusitis patients increases by 17,524.476.(P<.001, 95%CI:9,728.725-25,320.228) In addition, PM10 increases by $1{\mu}g/m^3$, the number of acute sinusitis patients increases by 3,163.471 (P<.001, 95% CI:2,268.642-4,058.301). If PM2.5 increases by $1{\mu}g/m^3$, the number of chronic sinusitis patients increases by 8,651.644.(P<.001, 95%CI:5,115.697-12,187.592) Conclusions : Both PM10 and PM2.5 are correlated with changes in the number of sinusitis patients. PM2.5 has effect on the number of patients than PM10. PM10 is the highest correlation in their 50s, PM2.5 in their 60s and 70s.

• Honam Mathematical Journal
• /
• v.39 no.2
• /
• pp.297-305
• /
• 2017

Let ${\alpha}$ > 0 be a real number and $(s_{\alpha}(n))_{n{\geq}1}$ be the lexicographically greatest Sturmian word of slope ${\alpha}$. We investigate Dirichlet series of the form ${\sum}^{\infty}_{n=1}s_{\alpha}(n)n^{-s}$. To do this, a generalization of Euler's totient function is required. For a real ${\alpha}$ > 0 and a positive integer n, an arithmetic function ${\varphi}{\alpha}(n)$ is defined to be the number of positive integers m for which gcd(m, n) = 1 and 0 < m/n < ${\alpha}$. Under a condition Re(s) > 1, this paper establishes an identity ${\sum}^{\infty}_{n=1}s_{\alpha}(n)n^{-S}=1+{\sum}^{\infty}_{n=1}{\varphi}_{\alpha}(n)({\zeta}(s)-{\zeta}(s,1+n^{-1}))n^{-s}$.

• 유체기계공업학회:학술대회논문집
• /
• 2006.08a
• /
• pp.323-326
• /
• 2006

Numerical solutions for spin-up problem of a thermally stratified fluid in a cylinder with an insulating sidewall and time-dependent rotation rate are presented. Detailed results are given for aspect ratio of O(1), fixed Ekman number $10-^{4}$, Rossby number 0.05 and Prandtl number O(1). Angular velocity of a cylinder wall changes with following formula, $\Omega_f=\Omega_i+\Delta\Omega[1-\exp(-t/t_c)]$. Here, this $t_c$, value, which is very significant in present study, represents that how fast/slow the angular velocity of the cylinder wall reaches final angular velocity. The normalized azimuthal velocity and meridional flow plots for several tc value which cover ranges of the stratification parameter S(1 ~ 10) are presented. The role of viscous-diffusion and Coriolis term in present study is examined by diagnostic analysis of the azimuthal velocity equation.

• Journal of Preventive Medicine and Public Health
• /
• v.17 no.1
• /
• pp.85-93
• /
• 1984

In order to develop some indicies for the evaluation of village health worker's activities and to find out personal characteristics and other factors that affect the activities, an interview survey was conducted to thirty seven village health workers (VHW) in Sunwon, Naega and Bulun townships in Kangwha county, where the Community Health Project of Yonsei University, College of Medicine, has been implemented for the past ten years. In addition, daily activity records of the VHW's were also analyzed. The results are summarized below: First, meeting attendance rates, number of regular family visits, number of antenatal care visits and number of family planning visits were identified as the most meaningful criterion for the evaluation of the village health worker's activities. Second, personal factors that significantly affect the village health worker's activities were identified as age, educational background, living with in-laws, religion, presence of preschool child in the family, holding leader's position of village woman's association concurrently, and duration serving as a VHW. The more aged and the more educated VHWs were the more effective. Those VHWs who were living with in-laws, without preschool child in the family, holding the leader's position of the village woman's association, and the longer service duration were the more effective. Other factors that affect the VHW's activities were the number of households in the target village and the number of natural villages in the target villages. It showed that the smaller the size of number of households and natural villages, the higher the degrees of the effectiveness of the VHW.