Fly ash consists of various metal oxides which can remove SO2 gas by the catalyst effect. When fly ash is added in the preparation process of pitch-based activated carbon, the pitch particles aggregate and fly ash is embedded in the activated carbon. To increase SO2 gas removal performance, activated carbon was prepared by surface-treated fly ash and petroleum-based pitch. Carboxyl groups were introduced into the fly ash by malic acid treatment. The introduced carboxyl groups acted as an activation agent to create micropore around the fly ash, and created micropores were exposed to the fly ash outside of the activated carbon. The exposed fly ash increased removal amount of SO2 gas by a catalytic effect of the metal oxides. The SO2 gas removal performance improved by 34% because of the catalyst effect of the exposed fly ash and improvement in the micropore structure in the activated carbon.

In the present study, carbon molded bodies were prepared by using graphite/coke fillers and petroleum-based binder pitch with various softening points, and the thermal properties of the prepared carbon molded bodies were investigated. The ratio of a binder affects the molded body preparation: no molded body was prepared at a low binder pitch content, and swelling occurred during the thermal treatment at a high binder pitch content. The binder pitch thermal treatment yield was the highest at 41 wt% at the softening point of 150 °C and the lowest at 23 wt% at the softening point of 78 °C. A significant mass reduction was found in the range of 150 to 300 °C in the petroleum-based binder pitch, and in the range of 300 to 475 °C in the coal-based binder pitch. The molecular weight of the binder pitch was analyzed through the matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) method. The molecular weight ratio within the interval showing the highest binder pitch molecular weight (178 to 712 m/z) was the highest at 66.4% in the coal-based binder pitch (softening point 115 °C) and the lowest at 46.0% in the petroleum-based binder pitch (softening point 116 °C). When the petroleumbased binder pitch was applied, as the softening point was increased, the voids decreased and thus the thermal conductivity increased. The highest thermal conductivity was 99.5 W/mK for the carbon molded bodies prepared using the coal-based binder pitch and 102.8 W/mK for those prepared by using the petroleum-based binder pitch. The results showed that the thermal properties were similar between the coal-based binder pitch (softening point 115 °C) and the petroleum-based binder pitch (softening point 150 °C).

용존 6가 우라늄은 다양한 화학종으로 존재하며, 화학종의 분포는 수용액의 pH에 의존한다. 산성 및 중성 근처의 pH 환경 에서는 대표적으로 UO2 2+, UO2OH+, (UO2)2(OH)2 2+, (UO2)3(OH)5 + 화학종이 공존한다. 수용액 속에 비결정성 실리카가 콜로이드 성질의 부유입자 상태로 존재할 때 용존 화학종은 실리카 표면에 쉽게 흡착된다. 이 연구에서는 표면 흡착 화학종의 분 포가 용존 화학종의 분포를 따르는지 조사하였다. 시료의 pH 값이 3.5-7.5인 조건에서 3종의 용존 화학종(UO2 2+, UO2OH+, (UO2)3(OH)5 +)과 2종의 표면 흡착 화학종(≡SiO2UO2, ≡SiO2(UO2)OH‐ 또는 ≡SiO2(UO2)3(OH)5 ‐)의 시간 분해 발광(luminescence) 스펙트럼을 측정하였다. pH 변화에 따른 각 화학종의 스펙트럼 변화 양상을 비교한 결과로 표면 흡착 U(VI) 화학종의 분포는 용존 U(VI) 화학종의 분포와 다르다는 것을 확인하였다.

In this study, pitch crosslinked by oxygen function groups was made into activated carbon (AC) and pore structure was observed. The oxygen functional groups were introduced by the addition of waste PET for pitch synthesis. Activation agent ratios used to obtain the AC during the activation process were 1:1, 1:2 and 1:4 (pitch:KOH, w/w). The oxygen content in the prepared pitch was characterized by elemental analysis. Also, the molecular weight of pitch was investigated by MALDITOF. Specific surface area and micropore volume of the prepared AC were determined by the argon adsorption–desorption analysis and calculated using the Brunauer–Emmett–Teller and Horvath–Kawazoe equations, respectively. Micropore fraction of PET-free AC was smaller than that of PET-added AC. At high activation agent ratio, mesopores were created when the micropore structure collapsed. However, in the PET-added AC, due to the oxygen crosslinking effect, the micropore structure and micropore size were maintained even at a high activation agent ratio. Therefore, PET AC was found to have a higher micropore fraction than that of PET-free AC.

The kidney is a highly complex organ, and acute or chronic renal diseases can occur with various complications such as diabetes and hypertension. So far, no target specific treatment is available in acute or chronic renal failure, necessitating the development of alternative therapeutic strategy. Recent experimental findings suggest that the renal function and structure can be restored after being treated with various sources of stem/progenitor cells. In this review, we discuss up-to-date findings of the potential of renal progenitor/stem cells in alleviating renal injuries with a focus on preclinical studies. We also review cellular mechanisms underlying the therapeutic function of these cells.

Honeybees are inevitably threatened by various pathogens including Sacbrood virus (SBV) and Galleria mellonella. Recently, RNA interference (RNAi) has been suggested as a promising strategy for suppression of honey bee viruses. Also, Bacillus thuringiensis (Bt) has been widely applied for the control of lepidopteran pests such as G. mellonella. In this study, it was intended to develop dsRNA production platform using Bt. For this, the pHT1K-SBV vp1 vector which transcribes sense and anti-sense SBV vp1 gene under control of Cyt1Aa sporulation-dependent promoter was introduced into Bt strain NT0423 expressing Cry1-types toxins. SBV replication was suppressed in the worker A. cerana ingested dsRNA produced from the Bt transformant. Crystal proteins from the Bt transformant showed high level of insecticidal activity against 4th instar larvae of G. mellonella.

Mosquitoes are medically important insect pests that act as vectors of various diseases when they feed on humans. Insect growth regulators (IGRs) could become an effective alternative to control mosquitoes because of their high specificity and relatively low toxicity to environment. Recently, we have developed high-throughput juvenile hormone antagonist (JHAN) screening system based on yeast-two hybrid assay. Actinomycetes have been reported to produce various bioactive compounds including insect growth regulators (IGRs). In this study, culture filtrates and mycelia extracts of 2,875 actinomycetes isolates screened for their IGR activities and mosquitocidal activities. Among 75 culture filtrates and 17 mycelia extracts with JHAN activities, 19 culture filtrate and 3 mycelia extracts showed high level of mosquitocidal activities against 3rd instar larvae of Aedes albopictus. These results suggested that secondary metabolites of actinomycetes could be used as environmentally benign mosquitocidal agents.

In order to investigate novel insect growth regulators (IGRs) from actinomycetes, 363 isolates of actinomycetes were tested for their IGR activities. Among them, Streptomyces sp. AN120537 showed the highest juvenile hormone antagonist (JHAN) activity and significant insecticidal activities against larvae of Aedes albopictus and Plutella xylostella. In addition, the dead larvae showed morphological deformities such as contraction of body segments or pigmentation of all body parts. Through liquid chromatography and bioassay-guided fractionation, 7 IGR compounds were identified from the crude hexane extract of AN120537. These results suggested that Streptomyces sp. AN120537 could be useful resources for development of eco-friendly insecticidal agents.

The vehicle routing problem is one of the vibrant research problems for half a century. Many studies have extensively studied the vehicle routing problem in order to deal with practical decision-making issues in logistics. However, developments of new logistics strategies have inevitably required investigations on solution methods for solving the problem because of computational complexity and inherent constraints in the problem. For this reason, this paper suggests a simulated annealing (SA) algorithm for a variant of vehicle routing problem introduced by a previous study. The vehicle routing problem is a multi-depot and multi-trip vehicle routing problem with multiple heterogeneous vehicles restricted by the maximum permitted weight and the number of compartments. The SA algorithm generates an initial solution through a greedy-type algorithm and improves it using an enhanced SA procedure with three local search methods. A series of computational experiments are performed to evaluate the performance of the heuristic and several managerial findings are further discussed through scenario analyses. Experiment results show that the proposed SA algorithm can obtain good solutions within a reasonable computation time and scenario analyses show that a transportation system visiting non-dedicated factories shows better performance in truck management in terms of the numbers of vehicles used and trips for serving customer orders than another system visiting only dedicated factories.