• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.6 no.1
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• pp.125-137
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• 1996

This study was designed to investigate effects of relative humidity on the breakthrough of charcoal tubes at a fixed vapor concentration and sampling time during mixed organic vapor sampling. A vapor generator was used to generate three different concentrations of mixed organic vapor and a stainless steel chamber was fabricated and utilized to maintain three different percentages of relative humidity while maintaining a constant temperature. The results were as follows; 1. At high relative humidity, breakthrough of mixed organic vapor occurred quickly at low vapor concentration than at high vapor concentration because of the reduced adsorption volume of charcoal tube due to humidity. 2. Breakthrough by competitive adsorption of vapors onto charcoal tube was observed at first from n-hexane having the lowest boiling point and highest vapor pressure among the three organic vapors investigated, followed by TCE. No breakthrough was observed from toluene under all experimental conditions. 3. For n-hexane, breakthrough was observed after 2 hours of sampling and breakthrough rates were increased as relative humidity increased. For TCE, breakthrough was found after 3 hours of sampling and breakthrough rates by sampling time were increased as vapor concentration increased. 4. The adsorbed amount of mixed organic vapor at breakthrough was shown to have statistically significant correlations with sampling time, relative humidity, and vapor concentration in descending order of correlation. Relative humidity and sampling time for n-hexane and sampling time and concentration for TCE were both statistically significantly correlated. 5. Relative humidity was found to affect the amount of breakthrough of mixed organic vapor and n-hexane. Among three percentages of relative humidity investigated, the amount of breakthrough at 85 % relative humidity was significantly larger than those of at lower percentages of relative humidity. No statistically significant difference was found between 25 % and 55 % relative humidity. 6. The results of multiple regression analysis between breakthrough and relative humidity, vapor concentrations showed that the coefficient of determination of mixed organic vapor was 0.263 and those of n-hexane and TCE were 0.275 and 0.189, respectively. 7. Flow rates of sampling pumps used were found to be affected by relative humidity present. At 25 %, 55 %, and 85 % relative humidity, the relative errors of sampling pump were 1.4 %, 13.4 %, and 18.6 %, respectively. In conclusion, the results of this study showed that high relative humidity could reduce the adsorption volume of charcoal tubes and subsequently increase breakthrough rates. Therefore, to prevent breakthrough when sampling mixed organic vapors, it is suggested that either sampling volume be reduced on the flow rate be lowered so as to minimize breakthrough of the most volatile organic vapor in the mixture. In addition, since the flow rates of a sampling pump can be adversely affected by high relative humidity, it is recommended to use a constant flow mode pump when sampling in the highly humid environment.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5681-5685
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• 2012

Three kinds of survival rates are generally used depending on the purpose of the investigation: overall, cause-specific, and relative. The differences among these 3 survival rates are derived from their respective formulas; however, reports based on actual cancer registry data are few because of incomplete information and short follow-up duration recorded on cancer registration. The aim of this study was to numerically and visually compare these 3 survival rates on the basis of data from the Nagasaki Prefecture Cancer Registry. Subjects were patients diagnosed with cancer and registered in the registry between 1999 and 2003. We calculated the proportion of cause of death and 5-year survival rates. For lung, liver, or advanced stage cancers, the proportions of cancer-related death were high and the differences in survival rates were small. For prostate or early stage cancers, the proportions of death from other causes were high and the differences in survival rates were large. We concluded that the differences among the 3 survival rates increased when the proportion of death from other causes increased.

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.1
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• pp.6-11
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• 1991

In order to classify the varieties by the characters to evaluating potential winter hardiness was examined using the relationships between autumn growth of seedling plants and the dry weight of plant(DW), and yield components of 1st cutting in 16 varieties of perennial ryegrass grown under individual plant basis.The results are summarized as tollows:1. The dry weight of plant(L)W) was positively correlated with the number of tillers of seedling plants, but negatively correlated with seedling vigors of plants in autumn growth. 2. The dry weight of plant(L)W) indicated positively significant correlations with the dry weight of heading tillers(HDW), number of tillers per plant(NT), number of vegetative tillers(VNT), number of heading tillers(HNT), dry weight of a tiller(WT) and heading rates(HR) of 1st cutting.3. Relative tiller appearance rates(RTAK) corresponded with the seasonal patterns of tillering ability. Thevariety with a low values of relative tiller appearance rates(RTAR) showed vigorous tillering ability inautumn growth, but the variety with a high values of relative tiller appearance rates(KTAR) showedvigorous tillering ability in spring growth.4. The dry weight of plant per relative tiller appearance rates(DW/RTAR) indicated positively significant correlations with the dry weight of plant(DU7, plant length(PL), dry weight of heading tillers(HDW), number of tillers per plant(NT), number of heading tillers(HNrr), dry weight of a tiller(WT) and heading rates(HR) of 1st cutting.5. The varieties were classified into 2 groups by the dry weight of plant per relative tiller appearance rates(DW/RTAR). Thus. Manhattan, P-2, Tonga, Tove, Hella. I'eramo and Fiesta belong to the group of DW/RTAII>l. 0, and Maprima, Caliente, Tempo, Gambit, Magella, Prana. Reveille, Barlet and Bravo belong to the group of DW/RTAR

• Communications of the Korean Mathematical Society
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• v.32 no.3
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• pp.619-635
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• 2017

In this paper we establish some newly developed results related to the growth rates of composite entire functions on the basis of their generalized relative orders and generalized relative lower orders.

• Korean Journal of Mathematics
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• v.26 no.1
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• pp.23-41
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• 2018

The main aim of this paper is to prove some results related to the growth rates of composite entire and meromorphic functions on the basis of their relative (p, q)-th order, relative (p, q)-th lower order, relative (p, q)-th type and relative (p, q)-th weak type where p and q are any two positive integers.

• Bulletin of the Korean Chemical Society
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• v.26 no.11
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• pp.1761-1766
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• 2005

Solvolysis rates of isopropenyl chloroformate (3) in water, $D_2O$, $CH_3OD$ and in aqueous methanol, ethanol, 2,2,2-trifluoroethanol (TFE), acetone, 1,4-dioxane as well as TFE-ethanol at 10 ${^{\circ}C}$ are reported. Additional kinetic data for pure water, pure ethanol and 80%(w/w) 2,2,2-trifuoroethanol (T)-water (W) at various temperatures are also reported. These rates show the phenomena of maximum rates in specific solvents (30% (v/v) methanol-water and 20% (v/v) ethanol-water) and, variations in relative rates are small in aqueous alcohols. The kinetic data are analyzed in terms of GW correlations, steric effect, kinetic solvent isotope effects (KSIE), and a third order model based on general base catalysis (GBC). Solvolyses based on predominately stoichiometric solvation effect relative to medium solvation are proceeding in 3 and the results are remarkably similar to those for p-nitrobenzoyl chloride (4) in mechanism and reactivity.

• Korean Journal of Mathematics
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• v.26 no.4
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• pp.629-663
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• 2018

Let us suppose that ${\mathbb{K}}$ be a complete ultrametric algebraically closed field and $\mathcal{A}$ (${\mathbb{K}}$) be the ${\mathbb{K}}$-algebra of entire functions on K. The main aim of this paper is to study some newly developed results related to the growth rates of iterated p-adic entire functions on the basis of their relative orders, relative type and relative weak type.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.2125-2129
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• 2016

Background: Stomach cancer is an aggressive malignancy that is difficult to detect at an early stage and therefore is characterized by poor survival rates. Over the last two decades, there has been no report of gastric cancer survival in Khon Kaen province, Thailand. The aim of this retrospective cohort study was to provide up-to-date information about the survival of gastric cancer patients in this province. Materials and Methods: Data from Khon Kaen population-based cancer registry, Faculty of Medicine, Khon Kaen University were newly obtained on 650 patients who were diagnosed with stomach cancer during the period 1 January, 2000 to 31 December, 2012. These were then followed up until death or the end of the study (31 December 2014). We calculated the observed survival with the actuarial life table method, and relative survival, defined as the ratio of observed survival in the group of the stomach cancer patients to the expected survival in the entire Thai population from the estimated generation life tables for Thailand of five-year birth cohorts from 1900 - 2000. Results: The 5 year observed and 5 year relative survival rates were 17.2 % (95% CI: 13.54-21.14) and 18.2 % (95% CI: 14.3-22.4), respectively. The highest 5 year relative survival rates were demonstrated among patients aged 45-65, with stage I or II lesions, with adenocarcinomas, with a body of stomach location, well differentiated and receiving surgery and/or chemotherapy. Conclusions: The observed and relative survival rates were close to each other. Our findings provide basic information beneficial to development of an effective treatment system and appropriately improved population-based cancer registration.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.E3
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• pp.129-136
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• 2003

Effects of inorganic aerosols on the kinetics of the hydroxyl radical reactions with selected aliphatic alkanes have been investigated using the relative rate technique. The relative rates in the absence and presence of aerosols were determined for n-butane, n-pentane, n-hexane, n-octane, and n-decane. P-xylene was used as a reference compound. Inorganic aerosols including (NH$_4$)$_2$SO$_4$, NH$_4$NO$_3$, and NaCl aerosols at two different aerosol concentrations that are typical of polluted urban conditions were tested. Total surface areas of aerosols were 1400 (Condition I) and 3400 $\mu$$m^2$ cm$^{-3}$ (Condition II). Significant changes in the relative rates in the presence of the inorganic aerosols were not observed for the n-butanel/$.$OH, n-pentanel/$.$OH, n-hexanel/$.$OH, n-octanel/$.$OH, and n-decanel/$.$OH reactions versus p-xylenel/$.$OH reaction. These results suggest that the promoting effects depend on the semiconducting property of the aerosols and the nature of the organic compounds.

• Journal of Environmental Science International
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• v.5 no.5
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• pp.657-662
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• 1996

Meteorological and flux data measured from semiarid watersheds (Lucky Hills and Kendall) during the summer rainy and winter periods were used to study the sensitivity of the those variables used in the estimation of evapotranspiration rates. Relative sensitivity was examined to compare the importance of four meteorological and flux variables (net radiation wind speed, air temperature, and relative humidity) on Penman potential evapotranspiration (PET) estimation. The study results show that variations in Penman PET rates during the summer rainy period at both watersheds appears to be controlled by air temperature adn net radiation. During the winter period at both watersheds, wariations in Penman PET rates appears to be controlled by relative humidity and air temperature.