Biomass of agricultural waste is getting increasing attention all over the world as it is a kind of renewable, abundantly available, low cost, and environmentally friendly resource. Preparation of activated carbon from agricultural waste via microwave-assisted chemical agent activation. The porosity, surface area, and functional and surface chemistry were featured by means of low-temperature nitrogen adsorption, Scanning Electron Microscopy, (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The best conditions resulted in activated carbon with adsorption capacity of 517.5 mg/g and carbon yield of 80.99%. The activated carbons from carbonized tobacco stem with K2CO3 activation by microwave radiation is highest of surface area, and total pore volume corresponded to 2557 m2/g, and 1.647 cm3/g, respectively, with a high contribution of mesopores, microwave power of 700 W, and irradiation time of 30 min. The results of the review showed that chemical activation could develop both microporosity and mesoporosity. The findings support the potential to prepare high surface area and micropore-activated carbon from agricultural waste by microwave-induced chemical activation.

Silver tellurite glasses with melting temperature of approximately 700°C were developed to immobilize 129I wastes. Longterm dissolution tests in 0.1 M acetic acid and disposability assessment were conducted to evaluate sustainability of the glasses. Leaching rate of Te, Bi and I from the glasses decreased for up to 16 d, then remained stable afterwards. On the contrary, tens to tens of thousands of times more of Ag was leached in comparison to the other elements; additionally, Ag leached continuously for all 128 d of the test owing to the exchange of Ag+ and H+ ions between the glasses and solution. The I leached much lower than those of other elements even though it leached ~10 times more in 0.1 M acetic acid than in deionized water. Some TeO4 units in the glass network were transformed to TeO3 by ion exchange and hydrolysis. These silver tellurite glasses met all waste acceptance criteria for disposal in Korea.

본 연구에서는 기존에 인체에 유익한 효과가 있고 부작 용 없이 장기간 안전하게 사용할 수 있으며 간보호 및 간 기능 개선에 탁월한 효과가 있는 표고를 추출 및 농축하여 원유에 농도별로 첨가하여, 3종의 유산균을 이용하여 발효하였다. 표고의 농도를 달리하여 유산균을 배양하였을 때 면역관련 물질인 ergothioneine 및 β-glucan의 함량 을 측정한 결과 ergothioneine함량은 30% 표고추출농축액에 L. plantarum이 첨가되어 배양된 발효물이 40.48 mg/100 g로 가장 높은 함량을 나타냈다. β-Glucan은 30 % 표고추출농축액에 L. brevis가 첨가된 발효물이 13.94 %로 가장 높은 함량이 나타났다. 두 면역관련 물질 모두 표고추출농축액 첨가량이 증가할수록 증가하는 경향을 나타냈다. SD rat을 간을 적출하여 일차 간세포로 분리해 발효물의 간보호 효과를 측정하였다. 표고추출농축액과 유산균 발효물을 10, 50, 100, 500 μg/mL을 일차 간세포에 처리 하여 MTT assay 방법으로 세포독성을 측정한 결과, 모든 농도에서 독성을 보이지 않았다. 또한 10 mM 아세트아미 노펜을 처리하여 독성을 유발한 일차 간세포에 시료를 처리하여 AST, ALT, LDH를 측정한 결과, 효소의 농도가 감소하여 간보호 기능에 효과가 있음을 확인하였다. 이중 L. brevis를 첨가하여 배양한 발효물 처리구에서 효소의 농도가 가장 감소한 것을 보았고, 가장 간보호 효과가 뛰어난 것을 확인하였다. 이상의 결과를 토대로 표고추출농축액에 유산균을 첨가하여 발효하였을 때, 기존의 표고보다 면역관련 물질의 함량이 증가하고, 간기능 보호에 더욱 효과가 있음을 입증하였다. 따라서 본 연구결과는 표고 유산균 발효물이 건강기능 소재로서 연구를 위한 기초 연구자료로 활용될 수 있 것으로 생각된다.

A carbon nanofiber was produced from the Areca catechu husk as a supercapacitor electrode, utilizing a chemical activation of potassium hydroxide (KOH) at different concentrations. One-stage integrated pyrolysis both carbonization and physical activation were employed for directly converting biomass to activated carbon nanofiber. The morphology structure, specific surface area, pore structure characteristic, crystallinity, and surface compound were characterized to evaluate the influence on electrochemical performance. The electrochemical performance of the supercapacitor was measured using cyclic voltammetry (CV) through a symmetrical system in 1 M H2SO4. The results show that the KOH-assisted or absence activation converts activated carbon from aggregate into a unique structure of nanofiber. The optimized carbon nanofiber showed the large specific surface area of 838.64 m2 g−1 with the total pore volume of 0.448 cm3 g−1, for enhancing electrochemical performance. Beneficial form its unique structural advantages, the optimized carbon nanofiber exhibits high electrochemical performance, including a specific capacitance of 181.96 F g−1 and maximum energy density of 25.27 Wh kg−1 for the power density of 91.07 W kg−1. This study examines a facile conventional route for producing carbon nanofiber from biomass Areca catechu husk in economical and efficient for electrode supercapacitor.

From measured thermal conductivity and modeling by simulation, this study suggests that U-factors are highly related to materials used between steel and polymer. The objective and prospective point of this study are to relate the relationship between the U-factor and the thermal conductivity of the materials used. For the characterization, EDX, SEM, a thermal conductive meter, and computer simulation utility are used to analyze the elemental, surface structural properties, and U-factor with a simulation of the used material between steel and polymer. This study set out to divide the curtain wall system that makes up the envelope into an aluminum frame section and entrance frame section and interpret their thermal performance with U-factors. Based on the U-factor thermal analysis results, the target curtain wall system is divided into fix and vent types. The glass is 24 mm double glazing (6 mm common glass +12 mm Argon +6 mm Low E). The same U-factor of 1.45 W/m2·K is applied. The interpretation results show that the U-factor and total U-value of the aluminum frame section are 1.449 and 2.343 W/m2·K, respectively. Meanwhile, those of the entrance frame section are 1.449 and 2.

본 연구는 미네랄 첨가제가 한우사 바닥에 미치는 영향을 조사하였다. 실험은 경남 진주시 소재 한우 번식우 농장에서 실시하였다. 우방당 미네랄 첨가제를 5 ㎏ 첨가하였으며, 시험구로는 무첨가구(CON); bentonite 시험구(BN); illite 시험구(IL); 및 fly-ash 시험구(FA)로 두었다. 각각의 시험구로 4개의 우방을 이용하였으며, 우방당 5마리 한우 암소를 공시하였다. 미네랄 첨가제를 처리한 후 각 우방당 5곳에서 0, 7, 14, 21 및 28일에 우분을 채취하였다. 샘플은 건물, 발효특성, 미생물 성상 및 가스 발생량 분석에 이용되었다. 전 기간 동안 건물과 acetate 함량은 미네랄 첨가제에 의한 영향은 나타나지 않았다. 무첨가구에서 7, 14 및 28일에 유기물 함량은 가장 높았고(p<0.05), 조회분 함량은 가장 낮았다 (p<0.05). IL 시험구에서는 14, 21 및 28일에 총 질소 함량이 가장 높았고(p<0.05), IL, BN 및 FA 시험구에서는 각각 14, 21 및 28일에 무첨가구보다 대장균이 낮았다(p<0.05). FA 시험구에서는 28일에 살모넬라 수가 가장 높았다(p<0.05). IL 시험구에서는 28일에 암모니아 발생량이 가장 높았고 (p<0.05), 황화수소는 전기간 동안 검출되지 않았다. 28일간 결과값을 평균하였을 때, 무첨가구에서 유기물 함량이 가장 높았고(p<0.05), 조회분 함량이 가장 낮았다(p<0.05). IL 시험구에서 총 질소 함량이 가장 높았고(p<0.05), BN 시험구는 ㏗가 가장 높았다(p<0.05). 대장균 수는 IL 시험구에서 가장 낮았고(p<0.05), 살모넬라 수는 무첨가구 보다 IL과 FA 시험구에서 더 낮았다(p<0.05). 따라서, 본 연구에서 광물질 첨가제는 분 중 가스 발생량에는 영향을 미치지 않았으나, 병원성 미생물인 대장균은 illite와 fly-ash 처리 시에 억제되는 효과가 있었다.

Chemical equilibrium calculations for multicomponent aqueous systems involving the reductive dissolution of magnetite (Fe3O4) with oxalic acid (H2C2O4) were performed using the HSC Chemistry® version 9. They were conducted with an aqueous solution model based on the Pitzer’s approach of one molality aqueous solution. The change in the amounts and activity coefficients of species and ions involved in the reactions as well as the solution pH at equilibrium was calculated while changing the amounts of raw materials (Fe3O4 and H2C2O4) and the system temperature from 25°C to 125°C. In particular, the conditions under which Fe3O4 is completely dissolved at high temperatures were determined by varying the raw amount of H2C2O4 and the temperature for a given raw amount of Fe3O4 fed into the aqueous solution. When the raw amount of H2C2O4 added was small for a given raw amount of Fe3O4, no undissolved Fe3O4 was present in the solution and the pH of the solution increased significantly. The formation of ferrous oxalate complex (FeC2O4) was observed. The equilibrium amount of FeC2O4 decreased as the raw amount of H2C2O4 increased.