• Title/Summary/Keyword: Equivalent Reaction Coefficient

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A Study on Displacement Effect of Different Foundation using Concrete and Rubble (콘크리트, 잡석에 의한 이질기초 치환효과에 관한 연구)

  • Lim, Hae-Sik;Park, Yong-Boo
    • Land and Housing Review
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    • v.2 no.2
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    • pp.189-194
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    • 2011
  • To reinforce bearing capacity-changed section or different foundation in the same building, empirical or simple tools have been used. To solve this problem, we suggest the analytical solution that can evaluate and reinforce the stability of foundation. To estimate the effect of reinforcement by replacement in different foundation, soil stiffness evaluation method taking into account the influence factor with respect to depth beneath the foundation need to be applied. In this paper, graphs and relevant formulae are suggested to calculate equivalent soil reaction coefficient showing the effect of reinforcement by crushed stone and lean concrete replacement.

Prediction of Thermal Expansion Coefficients using the Second Phase Fraction and Void of Al-AlN Composites Manufactured by Gas Reaction Method (가스반응법으로 제작된 Al-ALN 복합재의 제 2상 분율과 기공에 따른 열팽창계수 예측)

  • Yoon, Juil
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.18 no.4
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    • pp.41-47
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    • 2019
  • The advent of highly integrated, high-power electronics requires low a coefficient of thermal expansion performance to prevent delamination between the heat dissipation material and substrate. This paper reports a preliminary study on the manufacturing technology of gas reaction control composite material, focusing on the prediction of the thermal expansion coefficients of Al-AlN composite materials. We obtained numerical equivalent property values by using finite element analysis and compared the values with theoretical formulas. Al-AlN should become the optimal composite material when the proportion of the reinforcing phase is approximately 0.45.

Estimation of Kinetic Parameters of Nonenzymatic Browning Reaction Using Equivalent Time at Reference Temperarture with Linearly Increasing Temperature Profile (정속가열(定速加熱)조건에서 표준온도상당시간(相當時間)을 이용한 비효소적 갈색화 반응의 동력학 파라미터 추정(推定))

  • Cho, Hyung-Yong;Kwon, Yun-Joong;Kim, In-Kyu;Pyun, Yu-Ruamg
    • Korean Journal of Food Science and Technology
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    • v.25 no.2
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    • pp.178-184
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    • 1993
  • The procedure using equivalent time at reference temperature has been assessed for the estimation of kinetic parameters with experimental data. Kinetic studies of nonenzymatic browning reaction in model and food system were carried out with linearly increasing temperature method. These kinetic parameters, n, $k_{ref}$ and $E_a$ of the systems were evaluated from original data in one step by nonlinear least square regression. The one step procedure yielded efficiently accurate parameter estimation. Computer simulated data with the kinetic models were well consistent with experimental data (average correlation coefficient=0.96).

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A Study on the Compensation of the Inductance Parameters of Interior Permanent-Magnet Synchronous Motors Affected by the Magnet Size

  • Jang, Ik-Sang;Lee, Hyung-Woo;Kim, Won-Ho;Cho, Su-Yeon;Kim, Mi-Jung;Lee, Ki-Doek;Lee, Ju
    • Journal of Magnetics
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    • v.16 no.1
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    • pp.74-76
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    • 2011
  • Interior permanent-magnet synchronous motors (IPMSMs) produce both magnetic and reluctance torques. The reluctance torque is due to the difference between the d- and q-axis inductances based on the geometric rotor structure. The steady-state performance analysis and precise control of the IPMSMs greatly depend on the accurate determination of the parameters. The three essential parameters of the IPMSMs are the armature flux linkage of the permanent magnet, the d-axis inductance, and the q-axis inductance. In the basic design step of an IPMSM, the inductance parameters are very important for determining the motor characteristics, such as the input voltage, torque, and efficiency. Thus, it is very important to accurately estimate the values of the motor inductances. The inductance parameters of IPMSMs have nonlinear characteristics along the magnet size because the iron core is saturated by the magnet and armature reaction fluxes. In this study, the inductance parameters were calculated using both the magnetic-equivalent-circuit method and the finite-element method (FEM). Then the calculated parameters were compensated by the saturation coefficient function, which was also calculated via the magnetic-equivalent-circuit method and FEM.

Prediction of Sucrose Hydrolysis Rate using Equivalent Time at A Reference Temperature under Regular Temperature Fluctuations (규칙적인 온도변화에서 표준온도 상당시간을 이용한 Sucrose 가수분해속도의 예측)

  • Cho, Hyung-Yong;Hong, Seok-In;Kim, Young-Sook;Pyun, Yu-Ryang
    • Korean Journal of Food Science and Technology
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    • v.25 no.6
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    • pp.643-648
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    • 1993
  • A simple approximate model using equivalent time at a reference temperature ($t_{eq}$) was derived to predict quality changes caused by temperature fluctuations. The validity and effectiveness of this model have been assessed with experimental data of sucrose hydrolysis. Kinetic parameters of sucrose hydrolysis were estimated by one step method using equivalent time at a reference temperature with linearly increasing temperature profile. Sucrose hydrolysis was a first order reaction, and the activation energy was 25.84 kcal/mol. The extent of sucrose hydrolysis of liquid model system under accelerated test with sinusoidal temperature fluctuations were determined. The proposed model yielded accurate prediction with the correlation coefficient in the range of $0.92{\sim}0.99$.

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The Effects of Cure System on Vulcanization Reaction Constant and Physical Properties of Rubber Compounds (가황시스템 변화가 배합고무의 가황반응속도 및 물리적 특성에 미치는 영향)

  • Lee, Seag;Park, Nam Cook
    • Applied Chemistry for Engineering
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    • v.10 no.3
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    • pp.419-426
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    • 1999
  • In this study, the reaction rate constant, activation energy, total crosslinking density, elastic constant, cure properties ($t_5,\;t_{90}$), modulus, and abrasion resistance of rubber compounds were investigated as a function of cure temperatures, cure systems and reinforcing filler loadings. Reaction rate constants showed strong dependence on thc carbon black loading, cure temperature and cure system, and increased sharply with increasing the reaction temperatures. The lowest activation energy was obtained in the efficient cure (EC) system which corresponds to the high level of sulfur to accelerator ratio, and the activation energy was decreased with decreasing the carbon black loadings. The change of carbon black loadings directly affects the modulus and abrasion resistance, but the change of cure system showed various effects on the rubber compounds. Increased carbon black loadings showed the high modulus, improved abrasion resistance and short scorch time but decrease in crosslinking density and elastic constant. Higher crosslinking density and elastic constant were shown in the EC cure system regardless of carbon black loadings, but scorch timc ($t_5$) was not affected by the change of the ratio of sulfur to accelerator. Rapid optimum cure time ($t_{90}$) were showen in the EC cure system. Also, the equivalent cure curve coefficient of rubber compound was 0.96 for conventional cure (CC) system, and 0.94 for semi-efficient cure (SEC) and EC system regardless carbon black loadings. As regarding the abrasion resistance, wear volume showed the logarithmic increase for the loaded weight.

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Development of a Short-term Model for Ozone Using OPI (오존최대농도지표를 이용한 오존단기예측모형 개발)

  • 전의찬;김정욱
    • Journal of Korean Society for Atmospheric Environment
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    • v.15 no.5
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    • pp.545-554
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    • 1999
  • We would like to develop a short-term model to predict the time-related concentration of ozone whose reaction mechanism is complex. The paper targets Seoul where an ozone alert system has recently been employed. In order to develop a short-term prediction model for ozone, we suggested the Ozone Peak Indicator(OPI), an equivalent of the potential daily maximum ozone concentration, with precursors being the only limiting factor, and we calculated the Ozone Peak Indicarot as OPI={$ rac{(O_3)_{max}cdot(H_{eH})_{max}(Rad)_{max}$ to preclude the influence of mixing height and solar radiation on the daily maximum ozone concentration. The OPI on the day of the prediction is to be calcultated by using the relation between OPI and the initial value of precursors. The basic prediction formula for time-related ozone concentration was established as $O_3(1)={(OPI)cdot Rad(t-2)H_{eH}}$, using the OPI, solar radiation two hours before prediction and mixing height. We developed, along with the basic formula for predicting photochemical oxidants, "SEOM"(Seoul Empirical Oxidants Model), a Fortran program that helps predict solar radiation and mixing height needed in the prediction of ozone pollution. When this model was applied to Seoul and an analysis of the correlation between the observed and the predicted ozone concentrations was made through SEOM, there appeared a very high correlation, with a coefficient of 0.815. SEOM can be described as a short-term prediction model for ozone concentration in large cities that takes into account the initial values of precursors, and changes in solar radiation and mixing height. SEOM can reflect the local characteristics of a particular and region can yield relatively good prediction results by a simple data input process.t process.

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An experimental study on the impact of an agreement on the means to achieve nursing goals in the early postpartum period of primiparous mothers and enhance their self-confidence and satisfaction in maternal role performance (산욕초기 초산모의 간호목표달성방번 합의가 어머니 역할수행에 대한 자신감 및 만족도에 미치는 영향에 관한 실험적 연구)

  • 이영은
    • Journal of Korean Academy of Nursing
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    • v.22 no.1
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    • pp.81-115
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    • 1992
  • The problem addressed by this study was to determine the effect of nurse - patient agreement on the means to achieve nursing goals in the early postpartum period of primiparous mothers. It was hypothesized that the experimental treatment would result in hegher self-confidence and satisfaction in maternal role performance. This purpose was to contribute to the planning of nursing care to enhance self- confidence and satisfaction in maternal role performance and to the development of relevant nursing theory. Especially, the early postpartum period is crucial toward in recovery from childbirth and attainment of the maternal role. Maternal role attaintment is a complex social and cognitive process of stimulus -response accomplished by learning. Most women attain the maternal role sucessfully. But, some primiparous mothers experience difficultites in attainment of the maternal role due to lack of experience and knowledge. Self-confidence and satisfaction in maternal role performance are important factors in attainment and adjustment to the maternal role (Mercer, 1981a, 1981b ; Lederman, Weigarten, and Lederman, 1981 :Bobak and Jensen, 1985). Nursing is defined as behaviors of nurses add patients that attain nursing goals through action, reaction, interaction, and transaction. For attainment of nursing goals, active participating transactions must occur by agreement on the means to achieve those goals through nurse -patient mutual goal setting and establishment of their active relationships(King, 1981, Ha, 1977). Based on King's theory of goal attainment (1981), this stuy was planned as a non-equivalent control group, non -synchronized quasi -experimental design using agreement on the means to achieve nursing goals in early postpartum as the experimental treatment. The data were collected from July 20 to Sep. 1, 1991 by questionnaires with 60 primiparous mothers planing to breast feed after normal deliveries at W hospital in Pusan, Korea. The subjects were divided into a control group(conventional group) -those admitted from July 20 to Aug. 12, and an experimental group(agreement group) - those admitted from Aug. 13 to Sep. 1. The instument for agreement on the means to nursing goals in the early postpartum period included five steps - identification of disturbances of problems through action, reaction, and interaction with primiparous mothers : mutual early postpartal nursing goal setting : exploration of the means to achieve goals ; agreement on the means (self- care, ealry maternal -infant contact, performance of mothering behavior, and communicating about the infant's behavior and health condition) : implementation of the means. This instrument was developed on the basis of King's elements that lead to transactions in nurse-patient interactions. Lederman et al's (1981) scale for Confidence in ability to cope with tasks of motherhood and Lederman et al's(1981) scale for Mother's satisfaction with motherhood and infant care were used to measure self-confidence and satisfaction in maternal role performance ·with the subjects immediately after admission and on the day of discharge. Self-care performance in the experimental group was measured by self -evaluation tool developed by the investigator from the literature concerned. The tools to measure Pelf-confidence and satisfaction in maternal role performance, and the tool to measure self-evaluation of self-care performance were tested for internal reliability. Cronbach's Alphas were 0.94, 0.94, and 0.63. The data were analysed by using in S.P.S.S. computerized program and included percentage, x²-test, t-test, ANOVA, and Pearson Correlation Coefficient. The conclusions obtained from this study are summerized as follows : 1. The degree of self-confidence in maternal role performance of the total subjects group measured before the experimental treatment was above average with a mean score of 2.77(range 2.14-3.64). Out of 14 items, those with relatively high mean scores were ‘I would like to be a better mother than I am’(3.95), and ‘I have my doubts about whether I am a good mother’(2.87). Those with low mean scores were ‘I know that my baby wants most of the times’(2.28), ‘When the baby cries, I can tell what she /he wants’(2.37), and ‘I have confidence in my ability to care for the baby’(2;50). That is, the self - confidence of Primiparous mothers was considerably high in mothering, but rather low in activities concerning the infant care and understanding of the infant behavior. The degree of satisfaction in maternal role performance of the total subjects group measured before the experimental treatment was high with a mean score of 3.18(range 1.92-3.92). Out of 13 items, those with relatively high mean scores were ‘I am glad 1 had this baby now’(3.75), ‘I play with the baby between feedings when s/he is awake and quiet’(3.67), and ‘I enjoy being a mother’(3.27). Those with low mean scores were ‘I am upset about having too many responsibilities as a mother’(2.78), ‘It bothers me to get up for the baby at night’(2.82), and ‘I get annoyed if the baby frequently interrupts my activities’.(2.82), That is, the satisfaction of primiparous mothers was considerably high in mothering and infant care, but rather low in restraints in time or on the mother's self accomplishment and development. 2. Agreement on the means to achieve nursing goals in the early postpartum period included process of mutual goal setting, exploration of the means to achieve goals, and ahreement in concert means to achieve goals based on the mothers' condition, concerns, self-perception of the nurse - patient interactions. In the process of agreement, there was agreement that the means to achieve goals should be through trust and establishment of active relationships with the nurse through identification of problems according to planned nursing goals and active interaction, such as explanations, teaching, changing of opinions, acceptance or rejection of explanations, and proposing of questions. Therefore agreement on the means to achieve nursing goals in the early postpartum period appears to be an effective nursing intervention for primiparous mothers. 3. The degree of self- confidence in maternal role performance of the exprimental group was higher than that of the control group(t=3.95, p<0.01). Out of 14 items, those with higher score in the experimental group were ‘I would like to be a better mother than I am’(t=1.93, p<0.05), ‘I know that my baby wants most of the times’(t=2.75, p<0.01), ‘When the baby cries, 1 can tell what she/he wants’(t=2.10, p<0.05), ‘I have confidence in my ability to care for the baby’(t=3.72, p<0.01), ‘I trust my own judement in deciding how to care for the baby’(t=1.96, p<0.05), ‘I feel that I know my baby and what to do for him /her’(t=2.44, p<0.01), ‘I am concerned about being able to meet the baby's needs’(t=2.87, p<0.01), ‘I know what my baby likes and dislikes’(t=3.26, p<0.01), ‘I don't know to care for the baby as well as I should’(t=2.07, p<0.05), and ‘I am unsure about whether I give enough attention to the baby’(t=3.04, p<0.01), That is, the degree of self-confidence in mothering, activities concerning infant care, and understanding of infant behavior of the experimental group was higher than that of the control group. Therefore, the first hypothesis, that the degree of self-confidence in maternal role performance of the experimental group would be higher than that of the control group, was supported(t=3.95, p<0.01). 4. The degree of satisfaction in the maternal role performance of the exprimental group was higer than that or the control group(t=2.31, p<0.05). Out of 13 items, those with higher score in the experimental group were ‘I am glad I had this baby now’(t=2.29, p<0.05), ‘I enjoy taking care of the baby’(t=2.4g, p<0.01), ‘It is boring for me to care for the baby and do the same thing over and over’(t=2.87, P<0.01), ‘I am unhappy with the amount of time I have for activities other than childcare’(t=2.51, p<0.01), and ‘When bathing and diapering the baby, I would like to be doing something else’(t=2.43, p<0.01). That is, the degree of satisfaction in mothering, infant care, and restraints in time of on the mother's self accomplishment and development in the experimental group was higher than that of the control group. Therefore, the second hypothesis, that the degree of satisfaction in maternal role performance of the experimental group would be higher than that of the control group, was supported(t=2.31, p<0.05). 5. The third hypothesis, that the higher the degree of satisfaction in materenal role performance, the higher the degree of self-confidence in materenal role performance in the experimental group, was supported (r=0.57, p<0.01)

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