• 제목/요약/키워드: Rate-Determining

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Abuja시의 인구성장이 보건의료서어비스의 수요에 미치는 영향 (Effects of Growing Population and Demand for Health Care Services in the Federal Capital City, Abuja)

  • Olaleye, David Oyewole
    • 한국인구학
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    • 제12권1호
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    • pp.74-85
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    • 1989
  • Ascertaining the actual growth rate of the population is an issue that has generated a lot of arguments amongst various scholars in the process of determining the actual census count. As such, this has had a pronounced effect in the determination of the actual growth rates for different urban populations in the country. But the effect centres much when it comes to accurately determining the major components or the factors contributing to the rapid growth of urban populations. The problem of rapid population growth centres much on its effects on the available basic social services and amenities provided for the people in these areas. Factors such as levels of medical knowledge and services, nutrition, quantity and quality of housing etc. to some extent influence the quality and duration of lives of the people. As such, their importance cannot be overemphasized when dealing with the issue of population growth. The study aims to examine the rate of population growth in the Federal Capital City, Abuja with respect to the available public provision of basic social services among other objectives. The findings from the data obtained from the Population Survey conducted in the city in 1985 show that the health care facilities available in the capital city are grossly inadequate to serve the entire inhabitants of the city. Moreso, the volume of in-migration into the city also compounds the health problems facing the city. The conclusion is that there is need for more resources to be allocated to the health sector to guarantee adequate and functional health care services in the city.

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경피흡수제형의 in vitro 약물방출실험을 위한 연속확산 장치의 개발 (Development of Automated Diffusion Cell for Determining In Vitro Drug Release from Transdermal Device)

  • 변영로;최영권;정서영;김영하
    • 약학회지
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    • 제34권3호
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    • pp.161-165
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    • 1990
  • An automated, simple, and reliable method was developed for determining in vitro drug release rate from transdermal delivery dosage forms. The patch is held in position in the heating block by sandwiching it between the middle plate and the bottom plate of diffusion cell. The dissolution profile of the commercially available transdermal scopolamine patch was determined over a 72-h period, and the results were compared with those obtained with other methods; paddle-over-disk method, reciprocating method, and diffusion cell method. It was demonstrated that the flow-through method is equivalent in terms of release rate profile and accumulated released drug amount over the lifetime of the dosage form tested. Also this method is simple, reliable and reproducible. Therefore, this technique can be used in a quality control for assuring product uniformity.

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A Kinetic Study on Michael-type Reactions of 1-(X-Substituted Phenyl)-2-propyn-1-ones with Amines: Effect of Amine Nature on Reactivity and Mechanism

  • Um, Ik-Hwan;Hwang, So-Jeong;Lee, Eun-Ju
    • Bulletin of the Korean Chemical Society
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    • 제29권4호
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    • pp.767-771
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    • 2008
  • Second-order rate constants have been measured spectrophotometrically for the Michael-type reaction of 1-(Xsubstituted phenyl)-2-propyn-1-ones (2a-f) with amines in $H_2O$ at 25.0 ${\pm}$ 0.1 ${^{\circ}C}$. A linear Brønsted-type plot is obtained with ${\beta}_{nuc}$ = 0.25 ${\pm}$ 0.02, a typical $\beta_{nuc}$ value for reactions which proceed through a stepwise mechanism with attack of amine on the electrophilic center being the rate-determining step. Secondary alicyclic amines are found to be more reactive than isobasic primary amines. The Hammett plot for the reactions of 2a-f with morpholine is not linear, i.e., the substrate with a strong electron-donating group (e.g., 4-MeO) exhibits a negative deviation from the Hammett plot. However, the Yukawa-Tsuno plot for the same reactions exhibits an excellent linear correlation with ρ = 0.62 and r = 0.82. Thus, it has been proposed that the nonlinear Hammett plot is not due to a change in the ra te-determining step but due to ground-state stabilization through resonance interactions.

Correlation of the Rates of Solvolysis of Isopropyl Fluoroformate Using the Extended Grunwald-Winstein Equation

  • Lee, So-Hee;Rhu, Chan-Joo;Kyong, Jin-Burm;Kim, Dong-Kook;Dennis N. Kevill
    • Bulletin of the Korean Chemical Society
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    • 제28권4호
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    • pp.657-661
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    • 2007
  • The specific rates of solvolysis of isopropyl fluoroformate are well correlated using the extended Grunwald-Winstein equation, with a sensitivity (l ) to changes in solvent nucleophilicity (NT) and a sensitivity (m) to changes in solvent ionizing power (YCl). The sensitivities (l = 1.59 ± 0.16 and m = 0.80 ± 0.06) toward changes in solvent nucleophilicity and solvent ionizing power, and the kF/kCl values are very similar to those for solvolyses of n-octyl fluoroformate, suggesting that the addition step of an addition-elimination mechanism is rate-determining. For methanolysis, a solvent deuterium isotope effect of 2.53 is compatible with the incorporation of general-base catalysis into the substitution process. The large negative values for the entropies of activation are consistent with the bimolecular nature of the proposed rate-determining step. These observations are also compared with those previously reported for the corresponding chloroformate and fluoroformate esters.

Internal Company Factors as Determining Variables for Improving Bank Lending

  • PRAWITASARI, Dian;KADARNINGSIH, Ana;MACHMUDDAH, Zaky;UD-DIN, Maaz
    • The Journal of Asian Finance, Economics and Business
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    • 제7권8호
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    • pp.205-212
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    • 2020
  • This study seeks to examine the main factors, external and internal to the bank, that enhance bank lending. Bank lending is one of the connecting bridges in sustaining society. Internal factors consist of ROA, DPK, and CAR. External factors are economic growth and interest rate of Bank Indonesia. The population of this research consists of traditional commercial banks listed on the IDX over the 2014-2017 period. Samples were chosen by purposive sampling method. This study uses secondary data with 56 samples; data analysis uses multiple linear regression. The findings of the study show that internal factors have a greater impact on increasing bank lending than external factors. The main variable among internal factors that influences increase in bank lending is ROA. DPK is the internal factor with the smallest impact on increasing bank lending. The implication of the study is that determining the bank lending should take more account of CAR, DPK, ROA, BI interest rates, and economic growth in making decisions about the amount of lending. These variables can only have a slight effect on increasing lending, though. Besides, internal factors such as NPL, LDR or non-economic factors also need to be considered in channeling bank credit.

Kinetics and Mechanism of Michael-type Reactions of Ethyl Propiolate with Alicyclic Secondary Amines in H2O and MeCN: Solvent Effect on Reactivity and Transition-State Structure

  • Kim, Song-I;Baek, Hye-Won;Um, Ik-Hwan
    • Bulletin of the Korean Chemical Society
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    • 제30권12호
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    • pp.2909-2912
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    • 2009
  • The amines studied in this study are less reactive toward ethyl propiolate (3) in MeCN than in H$_2$O although they are 7 to 9 pK$_a$ units more basic in the aprotic solvent. The reactivity of morpholine and deuterated morpholine toward 3 is found to be identical, indicating that proton transfer occurs after rate-determining step (RDS). The fact that kinetic isotope effect is absent excludes a stepwise mechanism in which proton transfer occurs in RDS as well as a concerted mechanism in which nucleophilic attack and proton transfer occur concertedly through a 4-membered cyclic transition state (TS). Thus, the reactions have been concluded to proceed through a stepwise mechanism in which proton transfer occurs after RDS. Brønsted-type plots are linear with small ${\beta}_{nuc}$ values, i.e., ${\beta}_{nuc}$ = 0.29 in H$_2$O and ${\beta}_{nuc}$ = 0.51 in MeCN, indicating that bond formation is not advanced significantly in RDS. The small ${\beta}_{nuc}$ value also supports the conclusion drawn from the study of kinetic isotope effect.

Kinetics of $CO_2$ Absorption in Aqueous AMP (2-amino-2-methyl -1-propanol) Solutions

  • Park, Moon-Ki
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • 제2권1호
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    • pp.85-90
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    • 1998
  • The reaction rate of $CO_2$ with 2-amino-2-methyl-1-propanol (AMP), MEA monoethanolamine(MEA) and diethanolamine (DEA) in aqueous solutions has been determined using a stirred vessel with a plane gas-liquid interface over a wide range of concentrations of amines at different temperatures. The results show that the overall reaction rate is first order with respect to both $CO_2$ and amine. The reaction rate constant varies with temperature according to the relationship which agrees with the experimental data. The proposed interpretation is that the kinetic rate determining step is a reaction of $CO_2$ with amine to form carbamic acid which is then totally and immediately ionized.

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Asset Price, the Exchange Rate, and Trade Balances in China: A Sign Restriction VAR Approach

  • Kim, Wongi
    • East Asian Economic Review
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    • 제22권3호
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    • pp.371-400
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    • 2018
  • Although asset price is an important factor in determining changes in external balances, no studies have investigated it from the Chinese perspective. In this study, I empirically examine the underlying driving forces of China's trade balances, particularly the role of asset price and the real exchange rate. To this end, I estimate a sign-restricted structural vector autoregressive model with quarterly time series data for China, using the Bayesian method. The results show that changes in asset price affect China's trade balances through private consumption and investment. Also, an appreciation of the real exchange rate tends to deteriorate trade balances in China. Furthermore, forecast error variance decomposition results indicate that changes in asset price (stock price and housing price) explain about 20% variability of trade balances, while changes in the real exchange rate can explain about 10%.

피로균열 성장과정에 대한 평가방법의 영향 (Influence of Evaluation Methods for Fatigue Crack Growth Process)

  • 안철봉
    • 한국생산제조학회지
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    • 제8권1호
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    • pp.119-125
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    • 1999
  • The distribution of fatigue crack growth rate is subjected to the measuring interval and calculated method of growth rate. In this paper, in order to establish the method of determining the distribution of fatigue crack growth rate, which ignores those influences, a series of fatigue crack growth experiments and measuring intervals of crack length calculated reasonable are presented. The main conclusions obtained are summarized as follows: 1) As a result of the ΔP constant test and ΔK constant test, it is thought that an approximate measuring interval of 0.3~0.7mm is reasonable, which allows for few errors and is little subjected to the calculated method of crack growth rate. 2) After generally comparing the error estimation by using the experimental data of CCT specimen with the error rating of the CT specimens, it is possible that the fatigue test has few errors within the measuring interval, ξ(Δa/W)=0.0067~0.017, regardless of the dimension of specimen geometry.

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유전알고리즘과 퍼지추론시스템의 합성을 이용한 정수처리공정의 약품주입률 결정 (Determination of dosing rate for water treatment using fusion of genetic algorithms and fuzzy inference system)

  • 김용열;강이석
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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    • pp.952-955
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    • 1996
  • It is difficult to determine the feeding rate of coagulant in water treatment process, due to nonlinearity, multivariables and slow response characteristics etc. To deal with this difficulty, the fusion of genetic algorithms and fuzzy inference system was used in determining of feeding rate of coagulant. The genetic algorithms are excellently robust in complex operation problems, since it uses randomized operators and searches for the best chromosome without auxiliary information from a population consists of codings of parameter set. To apply this algorithms, we made the look up table and membership function from the actual operation data of water treatment process. We determined optimum dosages of coagulant (PAC, LAS etc.) by the fuzzy operation, and compared it with the feeding rate of the actual operation data.

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