• Title/Summary/Keyword: Rate Determining Step

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Factors related to Family Caregiver Satisfaction with the Institutional care services under the Public Long-Term Care Insurance system (노인장기요양보험 시설서비스에 대한 가족수발자 만족도 영향 요인)

  • Kwon, Jin-Hee;Han, Eun-Jeong;Lee, Jung-Suk
    • Health Policy and Management
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    • v.19 no.4
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    • pp.78-97
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    • 2009
  • This study examined the factors related to family caregiver satisfaction with institutional care services for beneficiaries under the Public Long-Term Care Insurance(PLTCI) system. Determining what contributes to family caregiver satisfaction is a critical step toward implementing effective quality improvement strategies. A national cross-sectional descriptive survey was conducted from November to December 2008, using proportionate quota sampling based on the location and level of Long-Term Care of the beneficiaries. Total 1,745 family caregivers wrote informed consents and 733 (response rate 42%) completed questionnaires, which included caregiver characteristics, organizational resources, primary objective and subjective stressors, perceived quality of services, and family caregiver satisfaction. Family caregivers were satisfied overall with institutional care. In multiple regression analysis, there was a statistically significant difference in degree of family caregiver satisfaction according to caregiver characteristics(relationship to beneficiary), primary objective stressors (insurance type of beneficiary), perceived quality of services(respect to family caregivers' idea, ADL support, expertness of staff, careful concern of staff, fulfillment of client's requests, and safety of institution's environment). In public long-term care, satisfaction efforts are in an early stage of development. This study is meaningful as the first attempt to measure family caregiver satisfaction with institutional care for beneficiaries under the PLTCI system, and to identify factors affecting the satisfaction. Among the identified factors, the policy makers, the insurer, and the providers need to pay attention to perceived quality of services, in particular, to improve customer satisfaction. Our findings can provide quality care improvement initiatives in the public long-term care setting.

Our Experiences in Nipple Reconstruction Using the Hammond flap

  • Yang, Jung Dug;Ryu, Jeong Yeop;Ryu, Dong Wan;Kwon, O Hyun;Bae, Sung Gun;Lee, Jeong Woo;Choi, Kang Young;Chung, Ho Yun;Cho, Byung Chae
    • Archives of Plastic Surgery
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    • v.41 no.5
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    • pp.550-555
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    • 2014
  • Background Nipple reconstruction following breast mound reconstruction is the final step in breast reconstruction. Although nipple reconstruction is a simple surgery, the psychological aspects of nipple reconstruction are thought to be important. Nipple projection is a key factor in determining patient satisfaction with the surgery. In the present study, the Hammond flap technique was introduced for nipple reconstruction. Methods Twenty-six patients who had undergone breast reconstruction from February 2008 to March 2012 were enrolled in this prospective study. All patients were evaluated based on preoperative photos, and their nipple diameters and heights were measured. Postoperative evaluation was conducted 3, 6, 9, and 12 months following nipple reconstruction. A questionnaire on patient satisfaction with the nipple reconstruction was administered 12 months after nipple reconstruction. Moreover, the same plastic surgeon scored nipple projection and overall cosmetic result of the new nipple. Results The mean projection was 4.4 mm (range, 3-6 mm), and it well matched the contralateral nipple. Twelve months following nipple reconstruction, the mean reduction rate in the nipple projection was 43.6%. Patients were satisfied or very satisfied with the nipple projection and the overall cosmetic result in 80.7% cases. Conclusions In the present study, compared with other techniques, the use of the Hammond flap technique in nipple reconstruction showed competitive results with regard to nipple projection and patient satisfaction.

Kinetics of Methanolysis of Arenesulfonyl Chloride in the Presence of Pyridines (치환 피리딘 존재하에서의 염화아렌 슬포닐의 가메탄올 분해반응의 속도론적 연구)

  • Kim Hyong Tae;Lee Ik Choon;Myung Soo Rim
    • Journal of the Korean Chemical Society
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    • v.33 no.5
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    • pp.468-476
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    • 1989
  • Kineties for the reactions of pyridines with 1-anthracenesulfonyl chloride (1-ASC) and 3-phenanthrenesulfonyl chloride (3-PSC) was investigated in methanol as solvent. Structural variation in pyridine followed $Br{\o}$ nsted and Hammett relations for both 1-ASC and 3-PSC; the corresponding coefficients, {\beta}\;and\;{\rho}\;at\;20^{\circ}C$ were 0.55, -3.5 for 1-ASC, and 0.43, -2.6 for 3-PSC respectively. Reactivity-selectivity principle was checked in competition system 1-ASC/3-PSC. As a result, this principle was found to hold at experimental temperatures, whereas to break down over in the range of isoselective temperature ($34.3^{\circ}C$). Judging from the above results and activation parameters, we concluded that these reactions proceeded by synchronous $S_n2$ mechanism in rate-determining step.

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Kinetic Study on Nucleophilic Substitution Reactions of 4-Nitrophenyl X-Substituted-2-Methylbenzoates with Cyclic Secondary Amines in Acetonitrile: Reaction Mechanism and Failure of Reactivity-Selectivity Principle

  • Lee, Ji-Youn;Kim, Min-Young;Um, Ik-Hwan
    • Bulletin of the Korean Chemical Society
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    • v.35 no.1
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    • pp.93-97
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    • 2014
  • A kinetic study is reported on nucleophilic substitution reactions of 4-nitrophenyl X-substituted-2-methylbenzoates (5a-e) with a series of cyclic secondary amines in MeCN at $25.0{\pm}0.1^{\circ}C$. The Hammett plots for the aminolysis of 5a-e are nonlinear, e.g., substrates possessing an electron-donating group (EDG) in the benzoyl moiety deviate negatively from the linear line composed of substrates bearing no EDG. In contrast, the Yukawa-Tsuno plots for the same reactions exhibit excellent linear correlations with ${\rho}_X$ = 0.30-0.59 and r = 0.90-1.15, indicating that the nonlinear Hammett plots are caused by stabilization of the substrates possessing an EDG through resonance interactions but are not due to a change in the rate-determining step (RDS). The Br${\phi}$nsted-type plots are linear with ${\beta}_{nuc}$ = 0.66-0.82. Thus, the aminolysis of 5a-e has been suggested to proceed through a stepwise mechanism in which departure of the leaving group occurs at the RDS. The ${\rho}_X$ and ${\beta}_{nuc}$ values for the aminolysis of 5a-e increase as the reactivity of the substrates and amines increases, indicating that the reactivity-selectivity principle is not applicable to the current reactions.

Theoretical Studies on the Addition Reactions of Ketene with NH3 in the Gas Phase and in Non-Aqueous Solutions

  • Kim, Chang-Kon;Lee, Kyung A;Chen, Junxian;Lee, Hai-Whang;Lee, Bon-Su;Kim, Chan-Kyung
    • Bulletin of the Korean Chemical Society
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    • v.29 no.7
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    • pp.1335-1343
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    • 2008
  • Theoretical studies on the un-catalyzed and catalyzed aminations of ketene with $NH_3$ and $(NH_3)_2$, respectively, were studied using MP2 and hybrid density functional theory of B3LYP at the 6-31+G(d,p) and 6- 311+G(3df,2p) basis sets in the gas phase and in benzene and acetonitrile solvents. In the gas phase reaction, the un-catalyzed mechanism was the same as those previously reported by others. The catalyzed mechanism, however, was more complicated than expected requiring three transition states for the complete description of the C=O addition pathways. In the un-catalyzed amination, rate determining step was the breakdown of enol amide but in the catalyzed reaction, it was changed to the formation of enol amide, which was contradictory to the previous findings. Starting from the gas-phase structures, all structures were re-optimized using the CPCM method in solvent medium. In a high dielectric medium, acetonitrile, a zwitterions formed from the reaction of $CH_2$=C=O with $(NH_3)_2$, I(d), exists as a genuine minimum but other zwitterions, I(m) in acetonitrile and I(d) in benzene become unstable when ZPE corrected energies are used. Structural and energetic changes induced by solvation were considered in detail. Lowering of the activation energy by introducing additional $NH_3$ molecule amounted to ca. −20 $\sim$ −25 kcal/mol, which made catalyzed reaction more facile than un-catalyzed one.

Aminolysis of Benzyl 2-Pyridyl Thionocarbonate and t-Butyl 2-Pyridyl Thionocarbonate: Effects of Nonleaving Groups on Reactivity and Reaction Mechanism

  • Kim, Min-Young;Lee, Jae-In;Um, Ik-Hwan
    • Bulletin of the Korean Chemical Society
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    • v.34 no.4
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    • pp.1115-1119
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    • 2013
  • A kinetic study is reported for nucleophilic substitution reactions of benzyl 2-pyridyl thionocarbonate (5b) and t-butyl 2-pyridyl thionocarbonate (6b) with a series of alicyclic secondary amines in $H_2O$ at $25.0^{\circ}C$. General-base catalysis, which has often been reported to occur for aminolysis of esters possessing a C=S electrophilic center, is absent for the reactions of 5b and 6b. The Br${\o}$nsted-type plots for the reactions of 5b and 6b are linear with ${\beta}_{nuc}$ = 0.29 and 0.43, respectively, indicating that the reactions of 5b proceed through a stepwise mechanism with formation of a zwitterionic tetrahedral intermediate ($T^{\pm}$) being the rate-determining step while those of 6b proceed through a concerted mechanism. The reactivity of 5b and 6b is similar to that of their oxygen analogues (i.e., benzyl 2-pyridyl carbonate 5a and t-butyl 2-pyridyl carbonate 6a, respectively), indicating that the effect of modification of the electrophilic center from C=O to C=S (i.e., from 5a to 5b and from 6a to 6b) on reactivity is insignificant. In contrast, 6b is much less reactive than 5b, indicating that the replacement of the $PhCH_2$ in 5b by the t-Bu in 6b results in a significant decrease in reactivity as well as a change in the reaction mechanism (i.e., from a stepwise mechanism to a concerted pathway). It has been concluded that the contrasting reactivity and reaction mechanism for the reactions of 5b and 6b are not due to the electronic effects of $PhCH_2$ and t-Bu but are caused by the large steric hindrance exerted by the bulky t-Bu in 6b.

Design and Implementation of Cattle Behavior Detection System based on Internet of Things (사물 인터넷 기반 소 행동 특성 관찰 시스템 설계 및 구현)

  • Lee, Ha-Woon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.12 no.6
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    • pp.1159-1166
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    • 2017
  • Cattle behavior detection system based on Internet of Things is designed and implemented by using gyroscope and acceleration sensor, Arduino pro-mini and bluetooth module. The implemented system measures cattle's moving and the measured data are transmitted to smart phone by bluetooth module. They are displayed by 2-dimensional graph on the smart phone and the number of cattle's step are calculated from the graph. The detected and gathered data from the system are analyzed by the proposed algorithm to decide which cows are in the estrus or not, and the proposed system can be used to increase the success rate of artificial insemination in normal estrus by detecting cow's behaviors such as the number of steps and jumping. In this paper, the implemented cattle behavior detecting system are strapped on cattle's leg and it measures cattle behaviors for determining that a cattle is estrus or not by the proposed algorithm. In the future research, the system which lengthens communication distance and increases the number of cattle under the test will be considered and also the measured data will be database for cattle research.

Kinetic Study on Aminolysis of 4-Chloro-2-Nitrophenyl X-Substituted-Benzoates in Acetonitrile and in 80 mol % H2O/20 mol % DMSO: Effect of Medium on Reactivity and Reaction Mechanism

  • Kim, Ha-Ram;Um, Tae-Il;Kim, Min-Young;Um, Ik-Hwan
    • Bulletin of the Korean Chemical Society
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    • v.35 no.4
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    • pp.1128-1132
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    • 2014
  • A kinetic study on aminolysis of 4-chloro-2-nitrophenyl X-substituted-benzoates (6a-i) in MeCN is reported. The Hammett plot for the reactions of 6a-i with piperidine consists of two intersecting straight lines, while the Yukawa-Tsuno plot exhibits an excellent linear correlation with ${\rho}_X$ = 1.03 and r = 0.78. The nonlinear Hammett plot is not due to a change in rate-determining step (RDS) but is caused by the resonance stabilization of substrates possessing an electron-donating group in the benzoyl moiety. The Br${\phi}$nsted-type plot for the reactions of 4-chloro-2-nitrophenyl benzoate (6e) with a series of cyclic secondary amines is linear with ${\beta}_{nuc}$ = 0.69, an upper limit for reactions reported to proceed through a concerted mechanism. The aminolysis of 6e in aqueous medium has previously been reported to proceed through a stepwise mechanism with a change in RDS on the basis of a curved Br${\phi}$nsted-type plot. It has been concluded that instability of the zwitterionic tetrahedral intermediate ($T^{\pm}$) in MeCN forces the reaction to proceed through a concerted mechanism. This is further supported by the kinetic result that the amines used in this study are less reactive in MeCN than in $H_2O$, although they are more basic in MeCN over 7 $pK_a$ units.

Studies on the Heat Storage Using the Hydration/Dehydration of the Calcined Dolomite (소성 Dolomite의 수화 및 탈수반응을 이용한 축열에 관한 연구)

  • Lee, Soo-Kag;Lee, Young-Sei;Kim, Jong-Shik
    • Applied Chemistry for Engineering
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    • v.3 no.3
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    • pp.507-515
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    • 1992
  • This study was carried out to investigate the heat-storage/-release characteristics of the thermochemical reaction of the calcined dolomite and steam system for the application of regenerative heat exchangers with the packed bed shape experimental apparatus. The experimental data were obtained at the following conditions ; the hydration temperature was $150-400^{\circ}C$, the dehydration temperature was $700-800^{\circ}C$ and the steam mass flow rates were 294, 430 and 567 g/hr. In the present study, it was found that MgO of the calcined dolomite was not hydrated during the hydration process under the studied experimental conditions. Therefore, MgO of the calcined dolomite can be regard as an inert material. Because the reaction was proceeded from the packed bed input to packed bed output and from wall to center, it could be thought that the rate determining step is not the reaction itself but the heat transfer.

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Determining chlorine injection intensity in water distribution networks: a comparison of backtracking and water age approaches

  • Flavia D. Frederick;Malvin S. Marlim;Doosun Kang
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.170-170
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    • 2023
  • Providing safe and readily available water is vital to maintain public health. One of the most prevalent methods to prevent the spread of waterborne diseases is applying chlorine injection to the treated water before distribution. During the water transmission and distribution, the chlorine will experience a reduction, which can imply potential risks for human health if it falls below the minimum threshold. The ability to determine the appropriate initial intensity of chlorine at the source would be significant to prevent such problems. This study proposes two methods that integrate hydraulic and water quality modeling to determine the suitable intensity of chlorine to be injected into the source water to maintain the minimum chlorine concentration (e.g., 0.2 mg/l) at each demand node. The water quality modeling employs the first-order decay to estimate the rate of chlorine reduction in the water. The first method utilizes a backtracking algorithm to trace the path of water from the demand node to the source during each time step, which helps to accurately determine the travel time through each pipe and node and facilitate the computation of time-dependent chlorine decay in the water delivery process. However, as a backtracking algorithm is computationally intensive, this study also explores an alternative approach using a water age. This approach estimates the elapsed time of water delivery from the source to the demand node and calculate the time-dependent reduction of chlorine in the water. Finally, this study compares the outcomes of two approaches and determines the suitable and effective method for calculating the chlorine intensity at the source to maintain the minimum chlorine level at demand nodes.

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