• Advances in materials Research
• /
• 제13권3호
• /
• pp.221-232
• /
• 2024

Waste tire management and recycling have grown to be significant issues because they bring up a global environmental concern. Thus, turning recycled waste tires into useful products may help tackle the environmental issue. This research aims to study and compare the effect of recycled carbon black (rCB) and commercial carbon black (CB) at certain 15 vol. % of filler loading on the mechanical, thermal, morphology and electrical properties of epoxy/CB composites. For this project, epoxy resin, diethyltoluenediamine (DETDA), recovered carbon black (rCB) and commercial carbon black (CB) graded N330, N550, N660 and N774 were mixed and compared accordingly to the formulation determined. The CB content was dispersed in the epoxy matrix using the mechanical mixing technique. The distribution and dispersion of CB in the epoxy matrix affect the characteristics of the conductive composites. rCB content at 15 vol% was selected at fixed content for comparison purposes due to the optimum value in electrical conductivity results. The flexural strength results followed the sequence of rCB>N774>N660>N550>N330. As for electrical conductivity results, epoxy/N330 exhibited the highest conductivity value, while the others achieved a magnitude of X10^-3 due to the highest external surface area of N330. In terms of thermal stability, epoxy/N330 and epoxy/N774 were slightly more stable than epoxy/rCB.

• Journal of Ecology and Environment
• /
• 제42권2호
• /
• pp.60-69
• /
• 2018

Background: This study was conducted from March 2011 to February 2013 in order to evaluate the ecosystem value by examining the organic carbon distribution and cycling in the Quercus glauca forest, evergreen oak community at Seonheul-Gotjawal, Jeju Island. Results: The amount of organic carbon distribution was $124.5ton\;C\;ha^{-1}$ in 2011 and $132.63ton\;C\;ha^{-1}$ in 2012 for aboveground biomass. And it was $31.13ton\;C\;ha^{-1}$ in 2011 and $33.16ton\;C\;ha^{-1}$ in 2012 for belowground biomass. In total, the amount of organic carbon distribution in plants was 155.63 and $165.79ton\;C\;ha^{-1}$ in 2011 and 2012, respectively. In 2011 and 2012 respectively, the amount of organic carbon distribution was 3.61 and $6.39ton\;C\;ha^{-1}$ in the forest floor and it was 78.89 and $100.71ton\;C\;ha^{-1}$ in the soil. As shown, most carbon was distributed in plants. Overall, the amount of organic carbon distribution of the Q. glauca forest was $238.13ton\;C\;ha^{-1}$ in 2011 and $272.89ton\;C\;ha^{-1}$ in 2012. In 2011, the amount of organic carbon fixed in plants through photosynthesis (NPP) was $14.22ton\;C\;ha^{-1}\;year^{-1}$ and the amount of carbon emission of soil respiration was $16.77ton\;C\;ha^{-1}\;year^{-1}$. The net ecosystem production (NEP) absorbed by the Q. glauca forest from the atmosphere was $5ton\;C\;ha^{-1}\;year^{-1}$. Conclusions: The carbon storage value based on such organic carbon distribution was estimated about $23.81mil\;won\;ha^{-1}$ in 2011 and $27.29mil\;won\;ha^{-1}$ in 2012, showing an annual increment of carbon storage value by $3.48mil\;won\;ha^{-1}$. The carbon absorption value based on such NEP was estimated about $500,000won\;ha^{-1}\;year^{-1}$.

• 신재생에너지
• /
• 제4권2호
• /
• pp.12-20
• /
• 2008

Calculations for the dissolution behavior of liquid CO2 droplets released in the East Sea and the Clipperton Clarion from a moving ship and a fixed pipeline have been carried out in order to estimate the CO2 dissolution characteristics in the ocean. The results show that the injection of liquid CO2 from a moving ship in a high temperature point is an effective method for dissolution. Also, it is noted that the ultimate plume generated from CO2 bubbles repeatsand shrinking due to the peeling from a fixed pipeline, and the presence of hydrate layer on a liquid CO2 droplet acts as a resistant layer in dissolving liquid CO2.

• 한국환경과학회지
• /
• 제11권6호
• /
• pp.569-576
• /
• 2002

Anaerobic/aerobic reactor system was used to treat a synthetic wastewater with glucose as carbon sources(0.38~2.29 kg COD/m3.day) and Acid Red 14(1.05 "24.00 g Acid Red 141m3.day, color degree of 570 ~ 1710). COD removal efficiency by the anaerobic stage in operation period were above 90 % organic loading rate of 0.38 ~ 2.29 kg COD/m3.day(except, adaptation period) and the removal efficiency of the whole system were above 96 %. The decolorization of the Acid Red 14 was through the alteration of the dye structure(or cleavage of the Azo bond) during the anaerobic treatment. In the A/A system, the anaerobic stage played an essential role in removing both color and COD. In addition it also improves biodegradability of dye f3r further aerobic treatment. After operation, average MLSS concentration of anaerobic sludge reactor, anaerobic fixed-bed reactor and aerobic fixed-bed reactor were 17100mg/L, 20000mg/L, and 10000mg/L, respectively.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
• /
• pp.597-601
• /
• 2008

Calculations for the dissolution behavior of liquid $CO_2$ droplets released in the East Sea and the Clipperton Clarion from a moving ship and a fixed pipeline have been carried out in order to estimate the $CO_2$ dissolution characteristics in the ocean. The results show that the injection of liquid $CO_2$ from a moving ship in a high temperature point is an effective method for dissolution. Also, it is noted that the ultimate plume generated from $CO_2$ bubbles repeatsand shrinking due to the peeling from a fixed pipeline, and the presence of hydrate layer on a liquid $CO_2$ droplet acts as a resistant layer in dissolving liquid $CO_2$.

• 한국생산제조학회지
• /
• 제20권4호
• /
• pp.434-439
• /
• 2011

There are about 2.4million disabled in Korea, 2009. Also, Korean society entered into an aging society. Therefore disable and elderly are getting more involved in our society. This study proposes simple ramp design for wheel chair users and welding method and condition for manufacturing. In the middle of ramp, screw jack and motor are installed so that ramp can be moved left and right side. To make the ramp moves easily, ramp was fixed by installing LM guide on both sides. Ramp production for using Nd:YAG laser certain dissimilar welding in stainless steel sheet and cold reduced carbon steel. The output was fixed by 3kW, the speed was increased to 2~7m/min, Argon was used as shielding gas and the flow rate was changed to 10~30L/min. The proper welding condition is the output 3kW and welding speed 2~5m/min.

• 한국방사성폐기물학회:학술대회논문집
• /
• 한국방사성폐기물학회 2003년도 가을 학술논문집
• /
• pp.73-77
• /
• 2003

In order to predict the dynamic behaviors of uranium and cobalt in a fixed bed at various influent pH values of liquid waste, the adsorption system was regarded as multi-component adsorption between each ionic species in a solution. Langmuir isotherm parameters of each species were extracted by incorporating equilibrium data with the solution chemistry of uranium and cobalt using IAST. Prediction results were in good agreement with the experimental data, except for a high concentration and pH. Although there was some limitations in predicting the cobalt adsorption, this method may be useful in analyzing a complex adsorption system where various kinds of ionic species exist in a solution.

• Structural Engineering and Mechanics
• /
• 제89권3호
• /
• pp.323-334
• /
• 2024

Physical and chemical factors can cause traditional timber constructions to lose structural integrity. Knowing the dynamic properties of the building components is vital to avoid damage to the buildings from dynamic effects, a subset of physical effects. In this work, spruce and scotch pine wooden beams that had been strengthened in three distinct ways with carbon fiber strengthened polymer (CFRP) were investigated for changes in their dynamic properties. For this, CFRP was used to strengthening unstrengthened wooden beams in the form of bottom confinement, U-shaped confinement, and full confinement after the dynamic parameters of the beams were determined. By using experimental modal analysis with both free-free and fixed-fixed boundary conditions, the beams'initial natural frequencies were identified.

• 공업화학
• /
• 제29권4호
• /
• pp.474-478
• /
• 2018

Thermal decomposition of waste Achyranthes Root (WAR) emitted from its decoction process was investigated using a TG analyzer and a fixed-bed reactor. The WAR had the larger C and fixed carbon content than fresh AR (FAR) due to the extraction of hemicelluloses from FAR during decoction process. Thermogravimetric (TG) analysis results also revealed the elimination of hemicellulose by its decoction. Relatively high contents of the cellulose and lignin made high contents of their typical pyrolyzates, such as acids, ketones, furans, and phenols, in the pyrolysis of WAR using the fixed-bed reactor. The increase of pyrolysis temperature from 400 to $500^{\circ}C$ increased yields of oil and gas due to the more effective cracking efficiency of WAR at a higher temperature. The chemical composition of product oil was also changed by applying the higher pyrolysis temperature, which increased the selectivity to furans and phenols.

• 청정기술
• /
• 제21권2호
• /
• pp.108-116
• /
• 2015

황화수소와 암모니아는 많은 하수처리장과 산업 플랜트로부터의 배출가스에서 발견되어질 수 있는 가장 흔한 악취성분이다. 이들 유해물질들은 인간에게 건강 문제를 일으키고 촉매에 악영향을 미치기 때문에 생활환경과 산업 현장에서의 제거는 매우 중요하다. 본 연구에서는 황화수소와 암모니아에 대한 우수한 흡착능력을 가지는 흡착제를 개발하기 위하여 폐타이어의 열분해 생성물인 카본블랙을 이용하였다. 카본블랙, 금속산화물과 산 또는 염기를 혼합하여 펠렛형 흡착제를 제조하였고, 상온상압에서 고정층 흡착탑의 파과곡선을 이용하여 황화수소와 암모니아에 대한 흡착성능을 평가하였다. 카본블랙, 산화철(III)과 수산화나트륨 혼합물로 제조된 흡착제가 황화수소에 대한 가장 우수한 작업능력을 나타내었다. 암모니아에 대해서는 카본블랙, 산화구리(II), 염산의 혼합물로 제조된 흡착제가 우수한 작업능력을 보였다.