• Title/Summary/Keyword: cure time

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A Study on the Properties of Polyurethane Resin Mixed with Butadiene Rubber (부타디엔 고무를 혼합한 폴리우레탄 수지의 물성에 관한 연구)

  • Hong, S.P.;Choi, S.G.
    • Elastomers and Composites
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    • v.28 no.1
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    • pp.13-21
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    • 1993
  • Polyurethane resin was especially mixed with polybutadiene rubbers which had each other different molecular structures and functional groups. Liquid and cure properties were tested experimentally for mixtures. Viscosity of mixtures and drying time were influenced by solubility of thinner and reactivity of rubber. Adhesive strength represented maxium at rubber content $15{\times}22%$ (Wt. % ), and rapidly decreased over 25%. DBTDL(di-n-butyltindilaurate) showed the longest stroage stability.

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Electrical Insulating Characteristics of Mixing Epoxy Resin (혼합 에폭시 수지의 전기 절연특성)

  • 홍경진;정우성;이은학;김태성
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1990.10a
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    • pp.95-97
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    • 1990
  • This study investigated electrical characteristic of solids and liquid epoxy resins by measuring dielectric breakdown and dielectric loss when epoxy resins were exposed to a mixing cure. It was found that mixing epoxy resins were superior to dielectric breakdown and hardness and has shorter curing time compare with those of pure liquid epoxy resins.

The Effort after Isotonic Lumbar Extension Exercise According to Surgery Invasiveness (수술 침습도에 따른 등장성 요부선전운동이 술후 체간 선전근력에 미치는 영향)

  • Nam, Kun-Woo;Lee, Hyun-Ok;Kim, Jong-Soon
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.11 no.2
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    • pp.83-95
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    • 2005
  • The purpose of this study is to analyze, durability of motor effort after finishing rehabilitation program and the influence from the isotonic lumbar region extension exercise after an operation according to the different operation way in invasive degrees. We selected randomly 80 patients who have no complication and musculoskeletal system diseases with finishing the 12 weeks' rehabilitation program after getting laser discectomy, but fail to conservative treatment, about Lumbar HNP, and divided into minimal invasive groups 38 and invasive groups 42 for study. As the results, in minimal invasive group, after finishing cure and 6 months later, the degree of hold muscle of women is much better than that of men. but in Invasive group, that of men is better than that of women, in case of women, the $0^{\circ}$ and $72^{\circ}$ in lumbar flexion angle have weaken or no improvement than before beginning exercise. and muscle force in $72^{\circ}$ in lumbar flexion angle increased to all men and women than before beginning exercise in Minimal invasive group. but in invasive group. it decreased. When analyze the lapsed time in Minimal invasive group, the groups who start the exercise within 3 months are better than the groups who start the exercise above 3 months after an operation the hold muscle degree all angles after finishing cure and 6 months later. Meanwhile, in invasive group, the groups who start the exercise within 3 months are better than the groups who start the exercise above 3 months after an operation about the hold muscle degree in 36-72 of lumbar flexion angle but 0-36 are not good after finishing cure and 6 months later. When analyze BMI in Minimal invasive group, the normal groups are better than the overweight groups about hold muscle degree in all angles after finishing cure and 6 months later.

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Leisure Time and Vacationing in Germany for Family Welfare (가족 복지를 위한 독일의 여가${\cdot}$휴가 문화)

  • Choi, Kyun-Ho;Jeong, Myeong-Soon;Lee, Moon-Ho
    • Journal of Family Resource Management and Policy Review
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    • v.10 no.1
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    • pp.67-81
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    • 2006
  • This study focused on the system regarding leave of absence in relation to family welfare, which has become a routine in some western countries, in three different perspectives. Those were the relations between reduced working hours and quality of life, maternal recreation, and finally, relations between infrastructure of vacation and culture. Systematic settlement of reduced working hours and maternal recreation in Germany allowed more time among family members and made large contribution to the improvement of family welfare in general. Since the stability of society is strongly based on the stability of family, Germany deserved to be case-studied as a good model. The recent tendency shows that Korean workers are starting to spend more time with their own family members than with their colleagues, and, as seen in the case of Germany, the stability of family welfare will improve if various infrastructures for family leisure are properly established in Korea.

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Strength Characteristic according to the 80℃ Water Curing Time Variation of the Ternary System Inorganic Binder (3성분계 무기결합재의 80℃ 수중양생 시간변화에 따른 강도특성)

  • Lee, Jin-Woo;Lee, Sang-Soo;Song, Ha-Young
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.05a
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    • pp.100-101
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    • 2014
  • The global warming because of the CO2 emission and solution about this emerge as the international enviroment problem. Particularly, it is the absolutely it is needed for reducing the CO2 in the cement industry and harmful material actual condition. And the construction of home and abroad and material manufacturers tries for the technology development for the carbon dioxide and harmful material reduction which the portland cement in manufacture is usually emitted along with the increase of concerns about the environment-friendly concrete and panel. Therefore, in this research, the compressive strength of the inorganic binder and flexural strength tries to be measured in order to draw the inappropriate high temperature cure time of the ternary system inorganic binder using the blast furnace slag, red mud, silica fumewhich is the industrial byproduct with the cement substitute material, and etc.

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Regression models generated by gamma random variables with long-term survivors

  • Ortega, Edwin M.M.;Cordeiro, Gauss M.;Hashimoto, Elizabeth M.;Suzuki, Adriano K.
    • Communications for Statistical Applications and Methods
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    • v.24 no.1
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    • pp.43-65
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    • 2017
  • We propose a flexible cure rate survival model by assuming that the number of competing causes of the event of interest has the Poisson distribution and the time for the event follows the gamma-G family of distributions. The extended family of gamma-G failure-time models with long-term survivors is flexible enough to include many commonly used failure-time distributions as special cases. We consider a frequentist analysis for parameter estimation and derive appropriate matrices to assess local influence on the parameters. Further, various simulations are performed for different parameter settings, sample sizes and censoring percentages. We illustrate the performance of the proposed regression model by means of a data set from the medical area (gastric cancer).

Study of Chip On Glass Bonding Method using Diode Laser (다이오드 레이저를 이용한 Chip On Glass 접합에 관한 연구)

  • Seo M.H.;Ryu K.H.;Nam G.J.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.10a
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    • pp.423-426
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    • 2005
  • A new chip on glass(COG) technique by making use of a high power diode laser for LCD driver IC packaging of LCD has been developed. A laser joining technology of the connection of IC chip to glass panel has several advantages over conventional method such as hot plate joining: shorter process time, high reliability of joining, and better fur fine pitch joining. The reach time to cure temperature of ACF in laser joining is within 1 second. In this study, results show that the total process time of joining is reduced by halves than that of conventional method. The adhesion strength is mainly 100-250 N/cm. It is confirmed that the COG technology using high power diode laser joining can be applied to advanced LCDs with a fine pitch.

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A Study on the Pathogenic Factors and Treatments of Exogenous Febrile Disease with Time (외감열병(外感熱病)의 원인(原因)과 치법(治法)에 대한 통시적(通時的) 고찰(考察))

  • Yang, Kwang-Yeol
    • Journal of Korean Medical classics
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    • v.21 no.1
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    • pp.295-302
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    • 2008
  • Until the middle of the 20th century, exogenous febrile disease was the most common disease that threatened the human health. For a long time, oriental medicine doctors developed many ways to cure this disease by studying pathogenic factors. The phthogenic factors and treatments of exogenous febrile disease with time are as followings. "Naegyeong(內經)" : Cold pathogen. Diaphoretic therapy, purgation therapy. Hwata : Cold pathogen. Diaphoretic therapy, emetic therapy, purgation therapy. Jangjunggyeong(張仲景) : Cold pathogen. Eight principal therapeutic methods except diaphoretic therapy with pungent and cool properties. Yuhagan(劉河間) : Fire pathogen. Diaphoretic therapy with pungent and cool properties. Idongwon(李東垣) : Improper diet and overstrain. Reinforcing therapy. Ouga(吳又可) : Epidemic pathogenic factors. Diaphoretic therapy with pungent and cool properties, Heat-reducing therapy. purgation therapy Seopcheonsa(葉天士) : Warm pathogen. diaphoretic therapy, Heat-reducing therapy, expel Heat therapy, cooling the blood and eliminating stagnation of blood. Oguktong(吳鞠通) : Six pathogenic factors. Eight principal therapeutic methods including diaphoretic therapy with pungent and cool properties.

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Modeling reaction injection molding process of phenol-formaldehyde resin filled with wood dust

  • Lee, Jae-Wook;Kwon, Young-Don;Leonov, A.I.
    • Korea-Australia Rheology Journal
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    • v.20 no.2
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    • pp.59-63
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    • 2008
  • A theoretical model was developed to describe the flow behavior of a filled polymer in the packing stage of reaction injection molding and predict the residual stress distribution of thin injection-molded parts. The model predictions were compared with experiments performed for phenol-formaldehyde resin filled with wood dust and cured by urotropine. The packing stage of reaction injection molding process presents a typical example of complex non-isothermal flow combined with chemical reaction. It is shown that the time evolution of pressure distribution along the mold cavity that determines the residual stress in the final product can be described by a single 1D partial differential equation (PDE) if the rheological behavior of reacting liquid is simplistically described by the power-law approach with some approximations made for describing cure reaction and non-isothermality. In the formulation, the dimensionless time variable is defined in such a way that it includes all necessary information on the cure reaction history. Employing the routine separation of variables made possible to obtain the analytical solution for the nonlinear PDE under specific initial condition. It is shown that direct numerical solution of the PDE exactly coincides with the analytical solution. With the use of the power-law approximation that describes highly shear thinning behavior, the theoretical calculations significantly deviate from the experimental data. Bearing in mind that in the packing stage the flow is extremely slow, we employed in our theory the Newtonian law for flow of reacting liquid and described well enough the experimental data on evolution of pressure.

Burning Properties of Uncured HTPB Propellant (HTPB 바인더를 이용한 미 경화 추진제의 연소 특성)

  • Kim, Nakhyun;Kim, Jungeun;Hong, Myungpyo
    • Journal of the Korean Society of Propulsion Engineers
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    • v.20 no.1
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    • pp.37-42
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    • 2016
  • In this study, we examined the burning rate of the uncured propellant (with and without a curing agent application) in order to inspect the process of the HTPB solid propellant. The burning rate of the uncured propellant, that did not contain the curing agent, was approximately 9.7 mm/s at 1000 psi. In relation to the curing time, the burning rate was constant. The propellant, with the curing agent application, was approximately 8.1 mm/s showed a tendency of slowing as it burned. When the cure reaction rate was low, in accordance to the time, there were small changes in burn rate. However, when the cure reaction rate was high, the difference in burning rate was increased. The burning rate of a fully-cured propellant was approximately 6.8 mm/s, which appeared to be the lowest in order.