• Journal of the Korea Concrete Institute
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• v.26 no.4
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• pp.449-456
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• 2014

Material properties of geopolymer, whose the reaction is very complicated, have been influenced by chemical compositions and particle size distributions of fly ash, concentrations and types of alkali-activators and curing conditions such as temperatures and time. In this research, experiments with several variables such as curing temperatures, preset prior to the high temperature curing and high temperatures have been conducted in order to evaluate to investigate effects on the compressive strengths of geopolymer caused by curing condition. Experiment results were evaluated with compressive strengths and micro-structures such as SEM and MIP of geopolymer pastes. As a result, as higher curing temperature or longer preset time were applied to the pastes, higher compressive strengths were observed. However, compressive strengths of geopolymer pastes declined due to increases in macropores (>50 nm) under high temperatures elapsed after 24 hours. In this sense, it can be considered that strengths and microstructures of geopolymers depends on curing temperature and time.

• Journal of Korean Medical classics
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• v.17 no.4
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• pp.171-175
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• 2004

본 논문에서는 고대 양생사상을 대표하는 "도덕경"과 한의학 양생사상을 대표하는 "황제내경소문 상고천진론"을 중심으로 양생의 의의, 양생의 목표, 방법, 기본사유 등 몇 가지 방면에서 두 경전의 내용을 비교하여 다음과 같은 공통점이 있음을 알 수 있었다. 첫째, 양생은 섭생과 동일한 의미로 천지자연의 이치에 따라 인제 생명을 건강하게 유지하여 장수할 수 있도록 하는 일체의 활동을 의미한다. 둘째, "상고천진론"과 "도덕경"이 모두 육체적 정신적으로 안정상태를 유지하여 질병이 없이 오래 사는 것을 양생의 목표로 삼고 있다. 셋째, 양생의 방법은 두 방면으로 요약할 수 있다. 첫째, 염담무욕(恬淡无欲)을 양생의 핵심요소로 삼았다. 이를 실천하기 위한 구체적 방법으로 노자는 '색(啬)'과 '반박(返朴)'을 제시하였고, 이러한 관념은 "상고천진론"에도 똑같이 보인다. 둘째, 근본 이치인 도(道)에 합치하는 것을 무병장수의 요건으로 삼았으며 구체적인 방법으로 천지자연의 사시음양(四時阴阳)의 규율을 따를 것을 강조하였다. 이는 천인상응사상(天人相应思想)과도 상통한다.

• Journal of Korean Medical classics
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• v.23 no.4
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• pp.13-30
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• 2010

继续上次的论文, 这次从"老老恒言"中论述的, 老年人消化器系的附属器官和消化系统的一般养生法, 得出下面的结论. 每次进食时, 老年人宜嚼烂以后慢慢地咽下, 平常别吐唾沫. 进食后应刷呀, 从而清除牙齿间的异物, 维持牙齿健康. 平时老年人宜摄取购买方便的, 又适合自己的饮食. 并而为了更好地消化吸收, 老年人可以用蒸露法以取得饮食的气味, 且宜多食用清淡的粥. 每天宜通调大小便. 得病的话, 要非常慎重地使用药物, 同时调节饮食, 只摄取对于治疗疾病有益的饮食和药物. 平常老年人宜少量饮茶, 少量饮酒, 而且节制吸烟为佳.

• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.1
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• pp.17-24
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• 2008

Many problems exist in the current cast in place concrete lining used in domestic tunnel construction. Especially, the crack of tunnel lining brings about a social and economic problem. It has a lot of influence on stability of structure and the fine finish of lining. So enormous repair-work and reinforcement of tunnel lining could occur an running out of government's budget. In our country, there are domestic production enterprises which produce a special pre-cast concrete product, but the technical level of them is still far behind compared to developed countries. Also, optimum steam coring method is important for the production of high quality product. But there is no regulation of steam curing method in our country. This study is to investigate the properties of PC panel according to the variation of steam curing conditions such as presteaming time and rate of temperature rise. The result shows that the optimum presteaming time of steam curing method in PC panel is more than 1 hour and the desirable rate of temperature in curing chamber is about $20^{\circ}C/hr$.

• Magazine of the Korea Concrete Institute
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• v.8 no.4
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• pp.141-148
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• 1996

The pulished works on Accelerated Curing Effect were generally performed around from 1960 to 1970th century for 18 to 24 hours - total curing periods. It is not possible to define the effect of temperature rise because those results were obtaine mainly by using the manually operated steam-curing tank. Thus, it may not be available to apply those data immediately on the domestic PC wall production line. The testing specimens were made from the standard mix proportion according to those of domestic PC factories to establish a basic data for the Accelerated Curing Effect. The experimental tests were conducted according to the conditions of each sub-curing periods. By comparing the results of compression tests on de-molded and 28-day water-curing specimens, we find that the most effective curing condition to obtain more than the required design strength after 28 day of water curing may be as follows: the presteaming period does not affect seriously and less than$30^{circ}C/hr$- the rate of temperature rise andless than $82^{circ}C$ - maximum temperature are necessary. It seems that post-curing procedure is very important factor to increase the effect of accelerated curing.

• Journal of Korean Medical classics
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• v.23 no.2
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• pp.271-285
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• 2010

"老老恒言"是清代著名养生家, 文学家曹庭栋所著. 曹庭栋, 于乾隆38年(1773年), 他在75岁之时参考307种历代书籍, 并结合自己体验而写成了"老老恒言". 本书又栋"养生随笔", 其不但内容丰富, 而且涉及老年养生的各个方面, 是一部老年养生专著. 本论文对"老老恒言"中论述的老年人的消化器系统之养生法中心分析如下. 因为?着年龄增长, 老年人脏腑功能越来越衰退, 所以对于老年人来说脾胃系统机能是最重要的. 老年人要经常保持腹部的暖和, 及舒适. 老年人吃饭的时候, 饮食应该有所节制, 切忌饥饱失常或者夜餐. 老年人饭食宜清淡, 盐的摄入最好保持最低量, 宜调和五味而忌杂以他味或者偏嗜. 老年人宜先饥而食, 先渴而饭, 食当有度. 并且宜少食多餐而忌错过饭, 一觉醒来别就吃饭. 饭食之冷热, 应该顺从四时变化, 冬宜热食m 夏宜凉食, 但其温度宜适当. 而且食物宜完全地煮烂, 有利于消磨输运, 吸收营养. 进?食以后, 就不宜躺在床上或者走得过快, 宜悠悠地散步. 并且肚子饥饿时, 不得大呼大叫.总之,老年人在节制饮食, 调理脾胃的基础上, 要注意调和五味, 清淡饮食, 要先饥而食, 少食多餐, 要注意冷热适宜, 食贵烂煮,要做到食勿急行, 饥勿呼叫, 最重要的是选取食物时, 当以身体察, 各随禀气所宜而食之.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.3
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• pp.149-160
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• 2015

This study reports the interfacial bond strength between Ultra High Performance Concrete (UHPC) and Normal Strength Concrete (NSC). While previous studies have focused on the interfacial strength between NSC substrate and UHPC overlay, this study use precast UHPC for enhanced constructability and replacement of formwork. The factors affecting the interface strength are comprehensively reviewed. It can be classified into: interface shape, degree of hardening and moisture condition of UHPC before combining with NSC, and curing condition of composite materials. Conducted experiments verify the effects of each factor on the interface strength and, accordingly show different failure modes. In particular, a new failure mode of the failure of a part of UHPC was firstly found in the case of sample with rough interface between UHPC and NSC. The other factors of the degree of hardening and the moisture and curing conditions of UHPC were discussed. This research will provide a valuable foundation to utilize the UHPC as a composite material.

• Journal of the Korea Concrete Institute
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• v.15 no.6
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• pp.888-893
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• 2003

The purpose of this study is to make clear the durability of the polymer films formed in the autoclaved polymer-modified mortars and concretes. The polymer films prepared with polymer dispersions such as a styrene-butadiene rubber (SBR) latex, a poly (ethylene-vinyl acetate)(EVA) emulsion and a polyacrylic ester (PAE) emulsion for polymeric admixtures are exposed to autoclaving at 18$0^{\circ}C$ in temperature and 1.01 MPa in vapor pressure, and subjected to tensile test and infrared spectroscopy. The durability of the polymer films is evaluated from the application of autoclaving to the polymer films under saturated Ca(OH)$_2$ solution immersion causes no degradation for SBR films and a significant degradation due to the saponification of the polymers for EVA and PAE films. Accordingly, in the application of autoclaving to polymer-modified mortars and concretes, it is suggested that SBR-modified mortars and concretes are hardly degraded but EVA- and PAE-modified mortars and concretes are markedly degraded by the saponification of the polymers.

• International Journal of Highway Engineering
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• v.4 no.4 s.14
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• pp.13-21
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• 2002

This study examines the importance of conditioning temperature and period before measuring fundamental properties of asphalt mixture. Marshall specimens were made and cured in the air for one day and conditioned by submerging at $60^{\circ}C$ water for 30 min before loading. It was observed that if the specimen was cured in a lower (or higher) than normal lab temperature ($25^{\circ}C$) before submerging, the measured values were not consistent. Indirect tensile strength (ITS) was also measured on the specimens cured at different temperatures. Although there is no regulation specifying how long the specimen should be conditioned before testing, it is recommended that the conditioning time be for the specimen to be at $25^{\circ}C$. Test must be conducted for the specimen cured well before conditioning for desired test. If curing temperature was lower or higher than normal, and mixture was not properly cured, then test results would not be reliable. This study showed how long the specimen should be submerged at $60^{\circ}C$ for Marshall test and conditioned at $25^{\circ}C$ for ITS test for the specimens cured in different temperature.

• Journal of Korean Medical classics
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• v.8
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• pp.46-113
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• 1995