There have been many efforts to modify and improve the properties of functional thin films by hybridization with nano-sized materials. For the fabrication of electronic circuits, micro-patterning is a commonly used process. For photochemical metal-organic deposition, photoresist and dry etching are not necessary for microscale patterning. We obtained direct-patternable SnO2 thin films using a photosensitive solution containing Ag nanoparticles and/or multi-wall carbon nanotubes (MWNTs). The optical transmittance of direct-patternable SnO2 thin films decreased with introduction of nanomaterials due to optical absorption and optical scattering by Ag nanoparticles and MWNTs, respectively. The crystallinity of the SnO2 thin films was not much affected by an incorporation of Ag nanoparticles and MWNTs. In the case of mixed incorporation with Ag nanoparticles and MWNTs, the sheet resistance of SnO2 thin films decreased relative to incorporation of either single component. Valence band spectral analyses of the nano-hybridized SnO2 thin films showed a relation between band structural change and electrical resistance. Direct-patterning of SnO2 hybrid films with a line-width of 30 μm was successfully performed without photoresist or dry etching. These results suggest that a micro-patterned system can be simply fabricated, and the electrical properties of SnO2 films can be improved by incorporating Ag nanoparticles and MWNTs.

Changes in major volatile odor components (VOC) and sensory properties of kimchi during ripening for 4 days were investigated, and major VOCs of the raw materials of kimchi were also analyzed. Seven of eight major VOCs of kimchi originated mainly from garlic, while one originated from ginger. During 4 days of kimchi ripening, the amount of ethanol, which was substantially higher than that of other VOCs, increased continuously but decreased slightly on the fourth day. The amount of diallyl disulfide decreased during ripening, while that of allyl mercaptan decreased on the first day and increased slightly thereafter. The amount of methyl allyl sulfide, diallyl sulfide, and methyl trisulfide increased continuously during ripening, while that of dimethyl disulfide and methyl propyl disulfide increased until the second day and decreased thereafter. Scores of overall acceptability, taste, and odor for kimchi ripened for 2 days were significantly higher than those of other samples (p<0.05). The correlation between scores of overall acceptability and the amount of dimethyl disulfide or methyl propyl disulfide was higher than that of other VOCs.

The first checklist of the North Korean insects was presented by Zhu (1969), and it included 34 species of Tortricidae. From the early 1970s to the late 1980s, the Hungarian Natural History Museum (HNHM) had conducted zoological expeditions to North Korea under cooperative scientific research agreements (Park & Lee, 1992). These expeditions added significant information to our knowledge of the fauna of North Korea, including a large numbers of Lepidoptera. Based on the entomological collection of Hungarian Natural History Museum, Budapest, we report three species of Tortricidae (Lepidoptera), Ancylis melanostigma Kuznetsov, Eucoenogenes japonica Kawabe, and Eucosma glebana (Snellen) for the first time from North Korea. Photos of adults and the genitalia of the newly recorded species are provided with brief comments on the distribution. Also taxonomic accounts for the species are given.

Some materials belonging to the Leptostrobus myeongamensis Kim were found in the Upper Triassic Amisan Formation, Nampo Group, Korea. This species is closely associated with the foliage of Czekanowskia ex gr. rigida Heer. Although none of Leptostrobus myeongamensis Kim has been found in organic connection with Czekanowskia leaves, it is considered that they belong to the same taxa based on their common occurrence. The occurrence of Leptostrobus myeongamensis Kim from the Late Triassic floras of Korea is one of the oldest records in the Mesozoic floras found in the world.

Toxicity of seven environment friendly agricultural materials (EFAM), which have been used in the domestic market were evaluated on honeybee (Apis mellifera) and asian multicolored ladybird beetle (Harmonia axyridis). Three EFAMs made from plant extract agents (Wangjoongwang Eco, Bogum Eco and Bestop Eco) and four EFAMs made from microbial utilizing agents (Worldstar Eco, Goodmorning, Bluechip and Cameleon) were investigated as EFAMs. In evaluation of toxicity on honeybee, the RT25 values of 3 EFAMs made from plant extract agents ranged from 1 to 3 days. Therefore, honeybee should be released 1-3 days after application of these EFAMs. Meanwhile, the four agricultural materials made from microbial utilizing agents did not show any mortality against honeybee. In evaluating the toxicity to adult and larva ladybird beetles, all seven EFAMs made from plant extract agents and microbial utilizing agents to show any mortality.

In this paper, the analysis of impact damage behavior of a reinforced concrete structure that undergoes both a shock impulsive loading and an impact loading due to the air blast induced from an explosion is performed. Firstly, a pair of multiple loadings are selected from the scenario that an imaginary explosion accident is assumed. The RC structures strengthened with advanced composite materials (ACM) are considered as a scheme for retrofitting RC wall structures subjected to multiple explosive loadings and then the evaluation of the resistant performance against them is presented in comparison with the result of the evaluation of a RC structure without a retrofit. Also, in order to derive the result of the analysis similar to that of real explosion experiments, which require the vast investment and expense for facilities, the constitutive equation and the equation of state (EOS) which can describe the real impact and shock phenomena accurately are included with them. In addition, the numerical simulations of two concrete structures are achieved using AUTODYN-3D, an explicit analysis program, in order to prove the retrofit performance of a ACM-strengthened RC wall structure.

Electrical discharge machining (EDM) is an attractive machining technique but it requires electrically conductive ceramic materials. In this study, Alumina matrix composites reinforced with CNTs were fabricated through CNT purification, mixing, compaction and spark plasma sintering (SPS) processes. nanocomposites with the different CNT concentrations were synthesized. The mechanical and electrical characteristics of /CNTs composites were examined in order to apply the materials to the EDM process. In addition, micro-EDM using wire electrical discharge grinding (WEDG) was conducted under the various EDM parameters to investigate the machining characteristics of machined hole by Field Emission Scanning Electron Microscope (FE-SEM). The results show that /CNTs 10%Vol. was more suitable than the other materials because high conductivity and large discharge energy caused violent sparks resulting in bad machining accuracy and surface quality.

This study was conducted to investigate the residue amount of harmful materials on the 153 commercial medical herbs in Gwangju area. It was performed using the GC-ECD, GC-NPD, GC-MSD and the LC-UVD,LC-FLD, LC-MSD to analyze 200 pesticides. The heavy metals were determined using a Mercury analyzer and AAS. The sulfur dioxides were analyzed by modified Monnier-Williams method. The residual pesticides were detected in 7samples, and were over MRLs (Maximum Risk Levels) in 2 samples (1.3%). The mean values of heavy metal contents (mg/kg) were Pb, 0.570; Cd, 0.081; As, 0.082; Hg, 0.0093. The measured values of Pb, As, Hg showed within MRLs. The excess samples of MRLs were 3 samples (changchul 2, cheongung 1) on Cd. The sulfur dioxides were over MRLs in 7 samples (4.6%), hwanggi and gugija. These results will be used to establish on the regulation of commercial medical herbs in Gwangju area.

입도조정기층 재료의 역학적 특성평가를 위하여 15개 시료에 대해 반복재하 삼축압축시험, CBR 시험, 투수계수시험을 수행하였다. 입도조정기층 재료의 CBR 값은 32~110 범위(평균 81)에서 매우 폭넓게 결정되었으며, 수침조건에서 팽창량은 0.04mm 이하로 나타났다. 입도조정기층 재료의 탄성계수는 체적응력의 영향을 매우 크게 받았으며 선형체적응력모델의 적용성이 가장 뛰어남을 확인하였다. 입도조정기층 재료의 탄성계수는 100MPa~600MPa, 모델계수 k1은 80~270, 모델계수 k2는 0.1~0.6 사이에서 결정 되었다. 체가름시험과 다짐시험에서 결정된 지수물성치로부터 입도조정기층 재료의 탄성계수를 결정하는 경험모형을 제안하였다. 제안된 경험모형의 결정계수는 모델계수 k1 결정에 있어서는 0.423, 모델계수 k2 결정에 있어서는 0.920, 응력단계별 탄성계수 결정에 있어서는 0.872로 평가되었다.

Recent high efficiency electronic devices have been found to have heat emission problems. As for LEDs, an excessive increase in the device temperature causes a drop of the luminous efficiency and circuit lifetime. Therefore, heat release in the limited space of such electronic parts is very important. This is a study of the possibility of using a coating of carbon materials as a solution for the thermal emission problem of electronic devices. Powdered carbon materials, cokes, carbon blacks, amorphous graphite, and natural flakes were coated with an organic binder on an aluminum sheet and the subsequent thermal emissivity was measured with an FT-IR spectrometer and was found to be in the range of 5~20 μm at 50˚C. The emissivity of the carbon materials coated on the aluminum sheet was shown to be over 0.8 and varied according to carbon type. The maximum thermal emissivity on the carbon black coated-aluminum surface was shown to be 0.877. The emissivity of the anodized aluminum sheets that were used as heat releasing materials of the electronic parts was reported to be in the range of 0.7~0.8. Therefore, the use of a coating of carbon material can be a potential solution that facillitates heat dissipation for electronic parts.

Wood-PP composite materials were prepared by Taguchi robust design method with L9 orthogonal array to optimize experimental conditions. Tensile strength of the composite materials was considered as the main properties. Amount of wood powder and modifier of resin were chosen as significant parameters. As the result of Taguchi analysis in this study, the amount of wood powder was the most influencing parameter on the increase of tensile strength. The optimal conditions were determined and these results were good agreement with data analyzed by Taguchi robust design method.

칼슘 및 왁스 코팅 포장재 처리가 절화백합과 장미의 절화수명 및 품질에 미치는 효과를 연구하였다. 공시재 료는 Lilium Oriental hybrid ‘Le Reve’와 Rosa hybrida ‘Fire King’를 사용하였으며, 25% 칼슘 및 36% 왁스 코팅 포장재 처리구에 포장 후 5oC와 20oC 저장고에 48시간동안 저장하였다. 절화 백합의 ‘Le Reve’ 경우 36% 왁스 코팅 포장재 처리구에 포장 후 5oC 저장시 상품의 수명은 대조구에 비해 2일정도 증가되었다. 그 러나 절화 장미 ‘Fire King’의 경우는 절화의 선도유 지나 수명에는 효과가 크게 나타나지 않았다. 그러므로 절화 백합의 경우에는 상품의 수확 후 기능성 포장재가 저장성 및 선도유지에 유용함을 알 수 있었다.