• 한국세라믹학회지
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• 제34권9호
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• pp.963-968
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• 1997

Coal tar pitch was used to study the effect of the pyrolysis conditions to produce mesophase pitch used as a matrix precursor for carbon/carbon composites. The pyrolysis conditions were presented in all cases that the total pressure was 1 atm and the first stage temperature was changed from 25$0^{\circ}C$ to 34$0^{\circ}C$ to remove the low molecular weight compounds in the pitch, and then, heated to 40$0^{\circ}C$ to form anisotropic mesophase as the second stage temperature. The first stage temperature was very affected to form resulting anisotropic mesophase pitch. The resulting mesophase pitches show a significantly increased anisotropic contents upto 30$0^{\circ}C$. However, the contents of mesophase were decreased above 30$0^{\circ}C$. It was the reason that the first stage temperature had been control the number of free radicals to react the aromatic compounds in the pitch to form high molecular weight compound. Therefore, the two stage pyrolysis method could be very effectively used to control various contents of anisotropic polyaromatic mesophase compared to continuous to continuous heating method.

• 건축역사연구
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• 제9권3호
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• pp.23-36
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• 2000

The bureaucrat-scholars, ruling class of the Choseon Dynasty, used to build small private pavilions for rest and study for themselves. In the early period of the Dynasty, the pavilions had plain shapes with rectangular plan and simple wooden structure without any walls so as to enjoy the surrounding scenery. From the 16th century, the building form began to change into some diverse one by putting in an ondol room, an unique floor heating equipment. The pavilions also began to show regional differences by placing the ondol rooms in the floor. Myonang-jong, a pavilion occupied by a famous bureaucrat-scholar Song Soon, was built at Damyang of the southwest part of the Korean peninsula, so called Honam area, in 1533. At first, the building form followed the ordinary early pavilion shape using simple wooden structure and wooden floor. But when it was rebuilt in 1654 after burning down by war, there happened some changes. An ondol room was put in the center of the floor, of which regarded as a dominant regional characteristic of the Honam area. The change of the building form of Myonang-jong showed that it was the 17th century Honam area got the regional characteristic in the architecture of pavilion.

• 한국건축시공학회지
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• 제20권1호
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• pp.53-60
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• 2020

본 논문은 동절기 콘크리트 보양 시 투입되는 에너지(전력) 소비량과 콘크리트 발열량 변화를 통해 단열갱폼의 단열성능을 검토하고자 하였다. 실험결과에 따르면, 일반갱폼은 콘크리트 타설 이후 12시간동안 에너지(전력) 소비가 3회 발생하게 된다. 반면 단열갱폼은 콘크리트 타설 후 21시간 동안 에너지(전력) 소비가 발생되지 않았다. 최종 전력 소비량은 일반갱폼이 단열갱폼보다 3.7배 높게 나타나 에너지(전력) 소비에서 단열갱폼의 우수한 성능을 확인할 수 있었다. 발열량 검토결과는 일반갱폼에서 콘크리트 타설 후 외기 온도변화에 따라 발열량이 크게 변하는 것을 알 수 있었다. 하지만 단열갱폼의 경우 프레임 일부에서 미비한 열손실이 발생했을 뿐 콘크리트 타설 직후부터 거푸집 탈형까지 일정한 발열패턴을 보여주고 있었다.

• 열처리공학회지
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• 제31권6호
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• pp.269-274
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• 2018

Grain-oriented electrical steel sheets are mainly used as core materials for transformers and motors. They should have excellent magnetic properties such as low core loss, high magnetic flux density and high permeability. In order to improve the magnetic properties of the electrical steel sheet, it is important to form Goss oriented grains with a very strong {110}<001> orientation. Recently, efforts have been made to develop Goss grains by controlling processes such as hot rolling, cold rolling, and primary and secondary recrystallization. In this study, the sheets containing 3.2 and 3.4wt.% Si were used, which were rolled with 1 and 10 passes with total thickness reduction of 89%. Heating was carried out for primary recrystallization with different heating rates of $25^{\circ}C/s$ and $24^{\circ}C/min$ until $720^{\circ}C$. The behavior of Goss-, {411}<148>-, and {111}<112>-oriented grains were analyzed using X-ray diffraction(XRD) and electron back-scatter diffraction(EBSD) analysis. The area fraction of Goss-oriented grains increased with the number of rolling passes during cold rolling; however, after the primary recrystallization, the area fraction of the Goss grains was higher and exact Goss grains were found in the specimens subjected to rapid heating after one rolling pass.

• 한국환경보건학회지
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• 제42권2호
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• pp.118-125
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• 2016

Objectives: The traditional type of residence in used in Mongolia, called a ger, is an important residential form and applies coal combustion for cooking and heating. The combustion of coal in ger is the major source of indoor air pollution. The purposes of this study were to measure indoor air pollution in ger and determine the effect of cooking and heating activities. Methods: Indoor temperature, relative humidity, particulate matter less than $2.5{\mu}m$ ($PM_{2.5}$) and black carbon (BC) were continuously measured for 24 hours in eight ger. The measurements were conducted in January or February 2015. Heavy metals in $PM_{2.5}$ filter samples were analyzed by ICP-MS. Results: Average indoor temperature and relative humidity were $19.6{\pm}4.6^{\circ}C$ and $21.4{\pm}5.2%$, respectively. The average indoor $PM_{2.5}$ concentration in the eight ger was $119.8{\mu}g/m^3$ and ranged from 69.4 to $202.7{\mu}g/m^3$. The peak concentrations of $PM_{2.5}$ and BC during cooking and heating periods were several times higher than the 24- hour average concentration. Conclusion: The major contributor to indoor $PM_{2.5}$ and BC concentrations in the ger was coal combustion for cooking and heating.

• 한국가시화정보학회지
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• 제14권1호
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• pp.57-61
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• 2016

We report a finding of fast(exceeding 2,000 K/s) heating of polydimethylsiloxane(PDMS), one of the most commonly-used microchannel materials, under cyclic loadings at high(~MHz) frequencies. A microheater was created based on the finding. The heating mechanism utilized vibration damping of sound waves, which were generated and precisely manipulated using a conventional surface acoustic wave(SAW) microfluidic system, in PDMS. The penetration depths were measured to range from $210{\mu}m$ to $1290{\mu}m$, enough to cover most microchannel heights in microfluidic systems. The energy conversion efficiency was SAW frequency-dependent and measured to be the highest at around 30 MHz. Independent actuation of each interdigital transducer(IDT) enabled independent manipulation of SAWs, permitting spatiotemporal control of temperature on the microchip. All the advantages of this microheater facilitated a two-step continuous flow polymerase chain reaction(CFPCR) to achieve the billion-fold amplification of a 134 bp DNA amplicon in less than 3 min. In addition, a technique was developed for establishing dynamic free-form temperature gradients(TGs) in PDMS as well as in gases in contact with the PDMS.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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• pp.66-71
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• 2009

To reduce the building energy consumption, the major advanced nations are conducting actively many researches on so called a "self-sufficient building(or other words zero energy building)" which can support its required energy by itself. Given this background, KIER(Korea Institute of Energy Research) built full size test-bed of the zero energy solar house in early 2002, and has studied on the self-sufficient heating load up to now. We analyse the sensitivity between the heating load and the solar radiation gain according to the change the effective transmittance of windows. The authors classified 9 cases by solar transmittance of glass. The results demonstrate the solar radiation amount is 0.466 MWh from the eastern zone of Fl.,1(the first floor), 0.332 MWh from Fl.,2(the second floor), 1.194 MWh form the southern zone of F1., and 0.822 MWh from the southern zone of Fl.,2 on the case 1(each cases are classified by window types). On the case 9, the solar radiation amount is 3.127 MWh, 2.662 MWh, 8.799 MWh and 6.078 MWh from the same condition. For the Fl.,1, the amount of Heat Load that is saved per year ranged 10.5 to 48 %, and the reduction was anywhere from 0.2 to 17.9% for Fl.,2

• 한국산업융합학회 논문집
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• 제8권1호
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• pp.47-55
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• 2005

Infrared heating has been traditionally used in industrial applications for processes such as dehydration of food industrial. This heating method involves the application of radiation in the wavelength range of 2 to 50 micrometers. In this work, simultaneous heat balance equations were developed to simulate the infrared radiation heating of agricultural products. The equations assume that moisture diffuses to the outer boundaries of the material in liquid form and evaporation occurs at the surface of the agricultural products. Energy for moisture evaporation is supplied by the infrared radiant energy. The optimum temperature and drying time for the best drying conditions of changing the red peppers with the moisture content of 18% and the restore rate of 80~85% are $80^{\circ}C$ and 44 hours. The performance of radiation tubes coating with the radiation paint developed in this research has the energy of $2.27{\times}103W/m^2{\mu}m$, $150^{\circ}C$ within the scope of radiation wave length of $2{\sim}30{\mu}m$ and has the radiation 0.92~0.93, which is superior to the general radiation tubes. The extinction coefficient according to the band pass filter using the 4 flux theory ha higher dependability on wave length, accounting for $2{\sim}17{\mu}m$ and $5{\times}105{\sim}106m-1$. A comparison between the theoretical energy transfer whose figures are interpreted according to 4 flux theory and the experimental energy transfer of far infrared dryer leads to the findings of the agreement less than 5%.

• 한국태양에너지학회 논문집
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• 제29권2호
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• pp.62-69
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• 2009

To reduce the building energy consumption, the major advanced nations are conducting actively many researches on so called a "self-sufficient building(or other words zero energy building)" which can support its required energy by itself. Given this background, KIER(Korea Institute of Energy Research) built full size test-bed of the zero energy solar house in early 2001, and has studied on the self-sufficient heating load up to now. We analyse the sensitivity between the heating load and the solar radiation gain according to the change the effective transmittance of windows. The authors classified 9 cases by solar transmittance of glass. The results demonstrate the solar radiation amount is 0.466 MWh from the eastern zone of Fl.,1(the first floor), 0.332 MWh from Fl.,2(the second floor), 1.194 MWh form the southern zone of F1., and 0.822 MWh from the southern zone of Fl.,2 on the case 1(each cases are classified by window types). On the case 9, the solar radiation amount is 3.127 MWh, 2.662 MWh, 8.799 MWh and 6.078 MWh from the same condition. For the Fl.,1, the amount of Heat Load that is saved per year ranged 10.5 to 48%, and the reduction was anywhere from 0.2 to 17.9% for Fl.,2.

• 한국태양에너지학회 논문집
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• 제31권6호
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• pp.103-110
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• 2011

The aim of this study was to analysis the Heating/cooling performance and Daylighting performance of Solar Window System built in apartments. the solar window is the idea to integrate daylight as a third form of solar energy into a PV/Solar Collector system. The process of this study is as follows: 1)Solar Window system was designed through the investigation of previous paper and work. 2)The simulation program(Lightscape3.2) was used in daylighting performance analysis. the reference model of simulation was made up to analysis daylighting performance on Solar Window system. 3)The simulation program(ESP-r, Therm5.0, Window6.0) was used in energy performance analysis. the reference model of simulation was made up to analysis energy and daylighting performance on Solar Window system. 4)The Size of Simulation model for daylighting and heating/cooling energy analysis was $148.5m^2$ 5)The lighting performance analysis was carried out with various variants, such as the size and installed area of Solar Window system. 6)Energy performance simulation was carried out with various variants, such as Integrated U-value of Solar Window system according to its position, installed angle and insulation thickness. Consequently, When Solar Window system is equipped with balcony window of Apartment, Annual heating and cooling energy of reference model was cut down at the average of $4.1kWh/m^2$ or 4.2%.