• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.7
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• pp.717-728
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• 2009

In the field of rocket propulsion system hydrogen peroxide has been used as mono-propellant and as the oxidizer of bi-propellants. At the beginning, hydrogen peroxide was used as mono-propellant for thrusters, but later it had been replaced by hydrazine, which has better specific impulse and storability. On the other hand, to drive turbo-pumps, hydrogen peroxide is still being utilized. As the oxidizer of bi-propellants it was used until 1970's and from 1990's hydrogen peroxide once again got back to developer's interest, because one of the recent development purposes of rocket propulsion system is low-cost and ecologically-clean. Until now the storability of hydrogen peroxide has been remarkably improved. The combination of Kerosene/$H_2O_2$ also shows similar accelerating performance to Kerosene/$LO_x$ combination because of higher propellant density and higher O/F ratio, even though the propulsion performance is not as good as the combination of Kerosene/$LO_x$. Moreover, its combustion products are much cleaner than Kerosene/$LO_x$ combination.

• Resources Recycling
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• v.19 no.3
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• pp.16-23
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• 2010

Coal briquette use has dramatically increased because of high oil prices. Hence, it is necessary to develop an environment-friendly recycling technique of the coal briquette ash. The coal briquette ash contains a large amount of an unburned carbon content and a mullite with high thermal property, so it is considered to be used as raw materials of sintered eco-brick. This study aimed to investigate on how the unburned carbon affects properties of the sintered eco-brick. The eco-brick was mixed with the ratio of 50 wt% coal briquette ash having the unburned carbon 10.5 wt% and 50 wt% cullet, then being sintered at $950^{\circ}C$, which of the compressive strength was in line with the first class of the sintered clay brick standard(KS L 4201). In particular, the compressive strength of the sintered eco-brick was equal to the first class of the KS L 4201 despite the increase of mixing ratio for coal briquette ash with 1.0 wt% unburned carbon to 70 wt%.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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• pp.79-79
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• 2011

최근 플라스틱 제품의 사용후 폐기에서 발생 되는 환경적인 문제점들이 대두 되고 있는 가운데, 이러한 제품에 대한 친환경적인 재료 설계에 대한 요구가 거세지고 있는 실정으로 플라스틱 업계의 사활이 걸릴 정도의 중요한 문제로 부각되고 있다. 본 연구에서는 이러한 플라스틱 제품의 치명적인 환경적인 문제점을 극복하고자, Matrix 물질이 되는 플라스틱에서 부터 친 환경적인 생분해성 수지를 사용하면서, 물성의 강화제로써 천연물 유래의 여러 종류의 섬유를 사용하고자 하였다.가장 보편화된 생분해성 플라스틱인 지방족 폴리에스테르 계통의 생분해성 수지와 Polylactic acid에 대해 검토를 하였다. 지방족 폴리에스테르 의 경우는 기존 플라스틱 제품과 비교해서 유연하고, 신장율이 높고, PLA 대비 내열 사용한계 온도도 높아서 물성적인 측면에서 상당한 장점을 가지고는 있으나 가격이 매우 고가이므로, 기존 플라스틱을 대체하는 것에는 문제점이 있다. 반면 PLA의 경우 지방족 폴리에스테르 대비 절반 이하의 가격이고 기계적 강도 또한 매우 높기 때문에 기존의 플라스틱을 대체할 수 있는 가장 유력한 물질로 대두 되고 있으나, 사출물과 같은 충격이 요구되는 제품에 있어서는 PLA 고유의 약한 취성이 가장 큰 단점으로 지적되고 있다. 본 연구에서는 이러한 PLA를 기반으로 PLA의 장점이 기계적 강성을 유지하면서, 취성을 보완하기 위해 PBS를 혼합 할 수 있는 기술을 개발하였으며, 또한 원재료의 Cost를 줄이고, PBS 혼합에 따른 PLA의 기계적 강도 감소를 보완하기 위해 천연물 유래의 Wood fiber, Starch, Bamboo fiber, Cellulose fiber, Paper fiber 와 같은 각종 천연 Filler를 사용하여 기계적 기계적 강도 감소를 최소화 하였다.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.3
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• pp.15-20
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• 2012

Processing of organic waste is converted to anaerobic digestion for environmental friendly and sustainable energy recovery and reduction of sludge. In this study, ECOPAD (ECOdays' Plug-flow Anaerobic Digster)design for a high solids content and high organic matter content were used to investigate an applicability and efficiency of food waste treatment and poultry wastewater treatment. Case-by-case analysis of treatment efficiency of ECOPAD using food waste of city "P" and city "S". Volatile Solids basis organic removal efficiency of city "P" and city "S" was 84% and 88% respectively. And, the content of methane (P City: 70%, S City: 71%) was measured similarly. In the case of poultry waste bio-gas production was measured to $1.6Nm^3/kg$-VSrem, and methane content was measured to 69%.

• The Journal of the Korea Contents Association
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• v.7 no.10
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• pp.157-164
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• 2007

Human made a vessel which was made naturally to store something being hunted and picked, which was a great invention.(n modern times, society changed and development of science gave us convenience in making a vessel and various kinds of store instruments which was made of pure natural material), They have built the house which became to be a part of nature, and studied a method of storing food to eat for four seasons, then displayed a storage house and storage containers everywhere of the house. Now Korean has the custody of kimchi in refrigerator at every house. With hot wind of well-being, Korean food is becoming to be globalized, according to this the world shows concern seriously about the pottery This study have three purposes, the first. checking documents about the development history of pottery which is a kind of ceramic, and then the second, through an scientific experiment, with studying characteristic of pottery being built by the wisdom of ancestors, informing the merit of pottery and necessity to the world, and futhermore, the third, working up the development of close environmental vessels putting to use the characteristic of pottery.

• Korean Chemical Engineering Research
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• v.47 no.2
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• pp.237-242
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• 2009

Various type of alternative fuel have been developed due to exhaustion of fossil fuel reserves and high oil price. Biodiesel is produced from the reaction of triglyceride, which is main component of animal fat and vegetable oil, and methanol by methanolysis as it is known for eco- friendly fuel for alternative petrodiesel. In this work, it was analyzed for the characteristics of the blended biodiesel with domestic petrodiesel according to blending ratio. Density, kinematic viscosity and flash point were increased with increasing the content of biodiesel. But the characteristic of blended biodiesel fuel were changed to aggravate in low temperature. Also, the derived cetane number(DCN) from IQT was increased by added biodiesel. Especially, the DCN of biodiesel from palm oil showed 71.26.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.2
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• pp.341-347
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• 2009

As a right-of-way security for the high power transmission line tower construction is becoming more and more difficult, the friendly environmental compact tower design is required. For a proper insulation for the compact tower, the polymer material are being tried. Some countries has already adapted, in the various polymer application and management data, polymer arm insulator to the transmission tower, and shown a stable operation. However, in our country, the polymer arm insulator has left much to be desired in the installation on the transmission line tower. But polymer material has been developed by high strength and technology and is expected to be used in various electric equipments. The polymer arm insulator is a one of good electric insulation materials to expand the power supply capacity in the rapid power demand increasement In this research, the new polymer am insulator is designed and its electric specifications are analyzed. Its mechanical specifications is verified through the field test on the compact tower which is modified by the polymer arm insulator.

• Applied Chemistry for Engineering
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• v.27 no.3
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• pp.330-334
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• 2016

Because several wood barks are massively produced in the forest area of Chungbuk province, it is required to develop technologies for their effective utilization. In this study, three kinds of barks from Robina pseudoacacie, Pinus densiflora, and Castanea crenata were used to remove water-soluble cadmium ions having 10, 20, 50, and 100 mg/L concentrations in each batch experiments, and R. pseudoacacie bark was selected as the most excellent biosorbent. Also, treatments with various acids and bases were performed to increase the removal efficiency of 100 mg/L cadmium ions using R. pseudoacacie bark as a biosorbent. When R. pseudoacacie bark was modified with 0.5 M KOH, the relatively high removal efficiency and adsorption amount of cadmium ions were obtained. In addition, when 9 M KOH-treated R. pseudoacacie bark was used for 30 min, the highest removal efficiency of 100 mg/L cadmium ions was 84.3%. Therefore, this experimental result can be effectively used as an environmental-friendly bioremediation technology to remove cadmium ions existed with various concentrations in water bodies and soils.

• Korean Chemical Engineering Research
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• v.47 no.3
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• pp.386-393
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• 2009

This study was to find out the quantitative relation between urban treed area(neighborhood parks) and the atmosphere environment in real condition, focusing the gas-phase non-reacting air pollutants(SOx and NOx) decreasing function of trees in urban area. It also developed a quantitative analysis method for evaluation of the atmosphere influence in the type of treed areas. We set up the Pagoda Park in Seoul and its neighbourhood as a modelling area to analyse air quality impacts by urban neighbourhood park trees. From the modelling result of the Pagoda Park case study, it is concluded that urban neighbourhood park has an important meaning to suppress construction of emission sources which drive the urban polluted air quality worse, even though park's trees have relatively small air purifying function. Especially in the urban area severely contaminated by air pollutants, the first considered air quality management policy is conservation of green spaces in neighborhood park.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.5
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• pp.78-88
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• 2002

본 연구는 울산월드컵경기장의 조경현황을 분석함과 동시에 경기가 끝난 후에도 이곳을 찾는 이용자들의 요구를 수렴함으로써, 향후 경기장조경시에 적용할 수 있는 교훈을 얻기 위한 목적을 두고 진행되었다. 조경현황에 대한 분석 자료는 월드컵경기장 조경을 위한 시공보고서와 도면 및 사진 그리고 현장에서 수집한 제반 자료이며, 이용자요구는 현장에서 조사한 이용행태이다. 연구결과 2002월드컵대회에 대비해서 만들어진 울산월드컵경기장은 건축공간을 확보하는 과정에 서 대규모의 정지작업을 실시하여 과다한 지형변화가 발생하였으나, 친환경적인 법면의 처리와 향토식생의 도입 및 대형목 등의 이식을 통해서 자연과 친화될 수 있는 경관을 조성하고 있었다. 특히 기존의 옥동저수지를 보전.활용하여 친수공간을 확보한 것은 울산월드컵경기장조경에서 주목할만한 특징으로써, 기회요소를 지혜롭게 활용한 좋은 사례가 되고 있다. 한편, 울산월드컵경기장은 시민들이 부담 없이 여가공간으로 활용할 수 있는 공원적 기능이 체육시설에 접목됨으로써 기존의 경기장과는 달기 체육, 문화, 교육기능이 복합적으로 기능하는 세계적 수준의 체육공원으로 개발되었다. 또한, 울산이 가진 역사 문화적 요소를 상징적인 설계언어로 도입한 것은 역사적 장소성을 중시한 설계방법으로서 이것 역시 울산월드컵경기장조경의 특징으로 손꼽을 수 있는 것이다. 특히 울산월드컵경기장은 경기가 종료된 이후에도 시민들에게 적극적으로 개방되고 있으며, 시민공원의 성격으로 이용될 수 있는 다원적 기능을 가지고 있어서 주목되는 바가 컸다 이와 같은 경기장 건설의 개념은 공간의 이용을 시간적으로 확장하는 것으로서 향후 보다 적극적으로 도입되어야 할 현대적 개념의 공간이용으로 볼 수 있다. 연구결과 향후 울산월드컵경기장이 시민의 휴식과 문화공간으로서 보다 적극적으로 기능하기 위해서는 경기장은 물론 공원으로 이용되는 공간에 대한 철저한 유지관리와 운영관리에 대한 노력이 필요할 것으로 생각된다. 특히 자연환경이 훼손된 부분에 대해서는 원래의 생태적 질서가 회복될 수 있도록 더욱 노력하여야 할 것이다.