Graphene has attracted the interest of many researchers due to various its advantages such as high mobility, high transparency, and strong mechanical strength. However, large-area graphene is grown at high temperatures of about 1,000 °C and must be transferred to various substrates for various applications. As a result, transferred graphene shows many defects such as wrinkles/ripples and cracks that happen during the transfer process. In this study, we address transfer-free, large-scale, and high-quality monolayer graphene. Monolayer graphene was grown at low temperatures on Ti (10nm)-buffered Si (001) and PET substrates via plasma-assisted thermal chemical vapor deposition (PATCVD). The graphene area is small at low mTorr range of operating pressure, while 4 × 4 cm2 scale graphene is grown at high working pressures from 1.5 to 1.8 Torr. Four-inch wafer scale graphene growth is achieved at growth conditions of 1.8 Torr working pressure and 150 °C growth temperature. The monolayer graphene that is grown directly on the Ti-buffer layer reveals a transparency of 97.4 % at a wavelength of 550 nm, a carrier mobility of about 7,000 cm2/V×s, and a sheet resistance of 98 W/□. Transfer-free, large-scale, high-quality monolayer graphene can be applied to flexible and stretchable electronic devices.

In this paper, we report graphene composite membranes prepared by transfer of a layer of chemical vapor deposition graphene onto porous anodic alumina (AA) substrates with nominal pore size 20 and 30 nm, referred as 20AA and 30AA. The coated and uncoated substrates were characterized using optical and electron microscopy techniques. The bare substrates exhibited a smooth surfaces with a well-organized array of hexagonal pores, displaying an average pore size of 17 ± 3 (20AA) and 23 ± 3 nm (30AA). The scanning electron microscopy and atomic force microscopy analyses confirmed the successful transfer of graphene layer onto the target substrates. The molecular transport study was performed by introducing 0.5 M potassium chloride (KCl) and deionized water in a Side-bi-Side Franz diffusion cell. The graphene/20AA specimen blocked 66% ions transport, and graphene/30AA membrane about 64%. The ions blockage exceeded 90%, near the characteristics of defectfree graphene when the defects of the transferred graphene were sealed with Nylon 6,6. The results of this study suggest the potential use of graphene on AA substrates for water desalination and gas purification applications.

In this study, we investigate the effect of Al/N source ratios and growth rates on the growth and structural properties of AlN films on c-plane sapphires by plasma-assisted molecular beam epitaxy. Both growth rates and Al/N ratios affect crystal qualities of AlN films. The full width at half maximum (FWHM) values of (1015) X-ray rocking curves (XRCs) change from 0.22 to 0.31° with changing of the Al/N ratios, but the curves of (0002) XRCs change from 0.04 to 0.45° with changing of the Al/N ratios. This means that structural deformation due to dislocations is slightly affected by the Al/N ratio in the (1015) XRCs but affected strongly for the (0002) XRCs. From the viewpoint of growth rate, the AlN films with high growth rate (HGR) show better crystal quality than the low growth rate (LGR) films overall, as shown by the FWHM values of the (0002) and (1015) XRCs. Based on cross-sectional transmission electron microscope observation, the HGR sample with an Al/N ratio of 3.1 shows more edge dislocations than there are screw and mixed dislocations in the LGR sample with Al/N ratio of 3.5.

본 연구는 느타리버섯 수확후배지를 배지자원으로 재사용하기 위하여 미생물처리에 의한 수확후 배지의 총질소함량 증진효과를 조사하였다. Bacillus sp. GM20-4 와 Rhodobacter sphaeroides(RS) 배양액 30%를 함께 접종하여 5일간 상온에서 배양 시 총질소 함량이 가장 크게 증가하였다. 농가의 수확후배지 조성에 따른 GM20-4와 RS 처리에 의한 T-N함량 변화를 조사하기 위하여 경기 지역 버섯재배농가 세 곳의 수확후배지(spent mushroom substrates, SMS A, B, C)를 수집하여 GM20-4 와 RS 배양액 30%를 처리한 결과, 무처리구에 비해 건조 SMS B 에서 T-N함량이 20%p로 가장 크게 증가하였고, 건조 SMS A는 17%, C는 12% 증가하였다. 반면에 생수확후 배지에서는 미생물 처리에 의한 T-N 함량 증가 효과가 크지 않았다. 또한 아미노산 조성별 함량 변화는 건조된 SMS A, B, C 모두 GM20-4와 RS 처리로 aspatic acid와 glutamic acid가 상대적으로 높게 증가한 결과를 보였고, 특히 건조 SMS B의 처리구에서 두 아미노산의 함량이 무처리구보다 2.9배 증가를 보임으로서 미생물처리가 수확후배지의 총질소 및 아미노산 함량의 증진효과를 확인하였다.

항암작용과 간 질환을 예방하는 약용곤충으로 널리 알려진 흰점박이꽃무지 유충은 2016년 12월 일반식품으로 등록되었으나 판매가가 높아 소비가 활발하게 이루어지지 않고 있어 생산 단가를 낮추는 기술이 요구되고 있는 실정이다. 흰점박이꽃무지의 생산 비용을 절감하고 생산성을 향상시키기 위해 농업부산물인 새송이버섯 수확 후 배지와 표고버섯 수확 후 배지를 유충의 먹이로 급이하여 생육특성과 미량성분, 중금속함 량을 조사하였고 대조구로는 관행으로 사용되고 있는 참나무 발효톱밥을 급이하였다. 새송이버섯 수확 후 배지를 급이한 처리구가 유충사육기간이 16.2일로 가장 짧았고 유충 무게 증가율과 고치 무게는 각각 156.3%와 4.1 g이었다. 새송이버섯 수확 후 배지를 급이한 처리구에서 용화율은 100%였고 우화율은 93.9%로 가장 높았지만 통계적 유의차는 없었다. 또한 총질소함량도 10.28%로 가장 높았고 미량원소 중 철은 145.8 mg/kg으로 다른 먹이와 비교해 높은 결과를 보였다. 성충의 산란선호성은 먹이 간 통계적 유의차가 없었다. 본 연구의 결과를 종합하였을 때 기존에 사용하고 있는 참나무 발효톱밥 대신 새송이버섯 수확 후 배지를 먹이로 사용하면 흰점박이꽃무지 유충 100 kg 당 667,960원의 비용이 감소할 것으로 추정된다.

We examined the characteristics of indium tin zinc oxide (ITZO) thin film transistors (TFTs) on polyimide (PI) substrates for next-generation flexible display application. In this study, the ITZO TFT was fabricated and analyzed with a SiOx/ SiNx gate insulator deposited using plasma enhanced chemical vapor deposition (PECVD) below 350℃. X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS) results revealed that the oxygen vacancies and impurities such as H, OH and H2O increased at ITZO/gate insulator interface. Our study suggests that the hydrogen related impurities existing in the PI and gate insulator were diffused into the channel during the fabrication process. We demonstrate that these impurities and oxygen vacancies in the ITZO channel/gate insulator may cause degradation of the electrical characteristics and bias stability. Therefore, in order to realize high performance oxide TFTs for flexible displays, it is necessary to develop a buffer layer (e.g., Al2O3) that can sufficiently prevent the diffusion of impurities into the channel.

Twelve strains of bacteria with cellulase and xylanase activities were isolated from spent mushroom substrates collected from button mushroom cultivation farm, Buye, Chungcheongnam-do in Korea. Among them, one strain, designated NO12, with higher cellulase and xylanase activities was selected by agar diffusion method. The strain NO12 was identified to be a Bacillus sp. by biochemical characteristics using Bacillus ID kit and MicroLog system. Comparative 16S rDNA gene sequence analysis showed that strain NO12 formed a distinct phylogenetic tree within the genus Bacillus and was most closely related to Bacillus subtilis with 16S rDNA gene sequence similarity of 99.2%. Based on its physiological properties, biochemical characteristics, and phylogenetic distinctiveness, strain NO12 was classified within the genus Bacillus, for which the name Bacillus subtilis NO12 was proposed. The cellulase and xylanase activities of B. subtilis NO12 were slightly increased according to bacterial population from exponential phase to stationary phase in the growth curve for B. subtilis NO12. The xylanase activity continuously increased from the beginning of the exponential phase and exhibited maximum activity in the middle of the exponential phase.

This study was conducted to investigate the effects of fermented spent mushroom substrates (F-SMS) of Flammulina velutipes on growth performance, carcass traits, and economic characteristics of Hanwoo steers. A yeast strain (Saccharomyces sp. UJ14) and Bacillus strain (Bacillus sp. UJ03) isolated from fresh spent mushroom substrates of Flammulina velutipes were used as probiotics to prepare F-SMS. Twenty-four Hanwoo steers (14 months old) were allocated to three dietary treatments via a randomized block design and were slaughtered at 30 months of age. These treatment groups included Control (TMR), T1 (TMR containing 10% of F-SMS) group, and T2 (TMR containing 30% of F-SMS). Body weight gain was not influenced by the experimental diets. DM and TDN intakes in the finishing period were significantly (p < 0.05) greater in group T1 than in other groups. CP intake was significantly (p < 0.05) greater in group T2 than in other groups during the whole experimental period. Among carcass traits, rib-eye area and back fat thickness tended to increase with F-SMS supplementation. The appearance rate (%) of a meat yield more than grade A was the highest in group T1. The net profits increased by 1.2% and 13.3% in groups T1 and T2, respectively. In conclusion, if a proper feeding program (including feed safety) can be ensured, spent mushroom substrates of Flammulina velutipes can prove to be a highly profitable feed source for Hanwoo steers.

본 연구는 팽이버섯 수확 후 배지를 첨가하여 호밀 사일리지 제조 시 팽이버섯 수확 후 배지를 에너 지원으로서 사용하기 위하여 in vitro 반추위 발효실험이 수행되었다. 공시 사일리지는 출수기의 호밀 에 팽이버섯 수확 후 배지 첨가비율(0%, 20%, 40%, 60%)에 따라 제조하여 6주일간 발효시켰다. In vitro 배양액 제조를 위한 반추위액은 농후사료와 볏짚을 40:60의 비율로 급여한 반추위 cannula가 시 술된 Holstein 수소 2두로 부터 채취하였다. In vitro 실험은 발효시간대를 3, 6, 9, 12, 24 및 48시간 으로 설정하고, 각 처리구별로 3반복으로 발효특성과 건물소화율을 측정하였다. In vitro 배양액의 pH 는 발효시간이 길어짐에 따라 낮아지는 경향이었으며, 48시간 경과 시에는 버섯수확 후 배지 60% 첨가 구가 타 처리구에 비해 유의적(p<0.05)으로 낮았다. 미생물 성장율은 배양시간이 경과함에 따라 증가 하는 경향이었으며, 발효 48시간 경과 시에는 버섯수확 후 배지 20% 첨가구가 타 처리구에 비해 유의 적으로(p<0.05) 높았다. Gas발생량은 48시간 발효 시에 대조구가 타 처리구에 비해 유의적(p<0.05)으 로 높았다. 건물소화율은 버섯수확 후 배지의 첨가비율이 높을수록 높았는데, 발효 24시간 및 48시간에 는 R-60구가 처리구 중에서 가장 높았으며(p<0.05), 대조구에서는 전 발효기간 동안 건물소화율이 현 저히 낮은(p<0.05) 상태에 있었다. In vitro 반추위내 발효실험의 결과와 버섯수확 후 배지의 활용성을 고려할 때, 호밀사일리지 제조 시 팽이버섯 수확 후 배지 첨가비율을 원물기준으로 60%수준이 가장 긍 정적인 것으로 나타났다. 향후 대사시험이나 사양시험을 통하여 가축사료로써의 최적 대체 비율을 규명 해야 할 것으로 사료되는 바다.

전해질막을 사용하는 알칼라인 연료전지는 최근 들어서 시스템 구성이 비슷하고 전해질막의 종류만 다른 기존의 양이온 교환막 연료전지를 대체할 수 있을 것으로 기대를 모으고 있다. 특히, 알칼라인 연료전지에서는 비백금계 저가 촉매가 사용 가능하여 많은 연구들이 진행되고 있다. 본 연구에서는 이러한 알칼라인 연료전지 시스템에 적용하기 위한 고성능, 고내 구성 음이온 교환막을 제조하기 위하여, 두 종류의 다공성 지지체인 폴리벤조옥사졸 지지체와 폴리에틸렌 지지체에 Fumion FAA 이오노머를 함침시켜, 기존의 Fumion 시리즈의 막보다 우수한 기계적 강도를 가지면서 높은 이온전도도를 유지할 수 있는 함침막을 제조하고자 하였다. 이를 통하여 최종적으로 지지체-함침막이 성공적으로 제조되었고, 이온 전도도와 기계적 특성이 지지체의 성질에 따라 서로 다른 결과를 보여 주었다. PE 지지체에 Fumion 이오노머를 함침시킨 함침막에서는 우수 한 기계적 특성이 얻어졌지만, 이온전도도는 감소하였으며 특히 높은 온도에서 성능감소가 더욱 증가하였다. 반면에 PBO 지 지체에 Fumion 이오노머를 함침 시킨 경우에는 PBO의 높은 염기성으로 인하여 함침 후에 높은 이온 전도도를 보였지만, Fumion-PE막에 비하여 상대적으로 낮은 기계적 특성을 나타내었다. 결과적으로 지지체-함침막 제조 시 알칼라인 연료전지의 운전조건에 따라 지지체의 특성을 충분히 고려하여 연구를 진행할 필요가 있다는 결론을 얻었다.

Recent studies indicate that mitochondria are an important source of reactive oxygen species (ROS) in the spinal dorsal horn. In our previous study, application of malate, a mitochondrial electron transport complex I substrate, induced a membrane depolarization, which was inhibited by pretreatment with ROS scavengers. In the present study, we used patch clamp recording in the substantia geletinosa (SG) neurons of spinal slices, to investigate the cellular mechanism of mitochondrial ROS on neuronal excitability. DNQX (an AMPA receptor antagonist) and AP5 (an NMDA receptor antagonist) decreased the malate-induced depolarization. In an external calcium free solution and addition of tetrodotoxin (TTX) for blockade of synaptic transmission, the malateinduced depolarization remained unchanged. In the presence of DNQX, AP5 and AP3 (a groupⅠ metabotropic glutamate receptor (mGluR) antagonist), glutamate depolarized the membrane potential, which was suppressed by PBN. However, oligomycin (a mitochondrial ATP synthase inhibitor) or PPADS (a P2 receptor inhibitor) did not affect the substrates-induced depolarization. These results suggest that mitochondrial substrate-induced ROS in SG neuron directly acts on the postsynaptic neuron, therefore increasing the ion influx via glutamate receptors.

In this study, we attempted to find alternative materials to rice bran (Japonica in Korea) such as rice bran pellet (Indica in Pakistan), corn distillers dried grains with solubles, sesame oil meal, and kapok meal for bottle cultivation of Pleurotus eryngii. Among all treatments, the total carbon content of the mixed substrate was the highest in T1 and the total nitrogen content was the highest in T4. The C/N ratio of T2 was comparable to that of the control and was higher than that of other treatments. The diameter of the pileus was the largest in T1 and T2, and the length of the stipe was the largest in T1 and T2. The yield and bio-efficiency of the fruit body were higher in T2 than in the other treatments, and were similar to that of the control plot. Therefore, the findings of our study suggest that rice bran pellet (Indica in Pakistan) could be a suitable alternative to rice bran (Japonica in Korea) for the cultivation of P. eryngii.

Supplemental substrates for mushroom cultivation media are potent sources for fungal contamination of indoor environment in cultivation houses. The present study was performed to investigate the presence of harmful fungi in the supplemental materials (beet pulp, cotton seed meal, kapok meal, peat moss, wheat straw) imported from China, Egypt, Germany, Indonesia and Pakistan. Fungal concentration in the supplemental materials ranged from 1.3×102 to 1.8×103 cfu/g. A total of 11 genera and 21 species were identified. Two genera and two species were found in Germany peat moss. In Pakistan wheat straw, three genera and four species were detected. In Egypt beet pulp and China cotton seed meal, four genera and five species and seven genera and ten species were shown, respectively. Among the identified fungi, Acremonium sp., Aspergillus chevalieri, Cryptococcus adeliensis, Eurotium amstelodami, Paecilomyces variotii and Rhodotorula mucilaginosa were known as human pathogens. This study provided evidence that pathogenic yeast and filamentous fungi are present in imported agricultural byproduct materials for mushroom cultivation.

In order to isolate thermophilic bacteria with high activity of CMCase and xylanase, spent mushroom substrates was collected from an oyster mushroom cultivation farm in Jinju, Gyeongnam, Korea. Among the isolates, one strain designated as YJ09 was selected by agar diffusion method. The isolate YJ09 was identified as a member of Bacillus licheniformis based on biochemical characteristics using Bacillus ID kit and MicroLog system. Comparative 16S rDNA sequence analysis showed that isolate YJ09 formed a distinct phylogenetic tree within the genus Bacillus and was most closely related to Bacillus licheniformis with sequence similarity of 98.9%. Based on its physiological properties, biochemical characteristics and phylogenetic distinctiveness, the isolate YJ09 was classified as Bacillus licheniformis. The CMCase and xylanase activity of B. licheniformis YJ09 was slightly increased corresponding to the bacterial population from exponential phase to stationary phase in the growth curve of B. licheniformis YJ09.

Bottom mushroom (Agaricus bisporus) is an edible basidiomycete mushroom in Europe and North America. The wheat straw, wheat brain and chicken manure were used for bottom mushroom cultivation. Bottom mushroom substrates for cultivation was collected from bottom mushroom farm in Buyeo. About 16 bacteria were isolated from fresh mushroom substrates on TSA medium. Among of the isolates, isolate 3HS12 possessed high cellulase and mannase activity was selected as a hydrolase-producing bacteria. The isolate 3HS12 was identified as members of the Bacillus subtilis by biochemical characteristics using Bacillus ID kit and VITEK 2 system. Comparative 16S rDNA gene sequence analysis showed that isolate 3HS12 formed a distinct phylogenetic tree within the genus Bacillus and was most closely related to Bacillus subtilis with 16S rDNA gene sequence similarity of 98.8%. On the basis of its physiological properties, biochemical characteristics and phylogenetic distinctiveness, the 3HS12 isolate was assigned to the Bacillus subtilis. The cellulase and mannase activity of Bacillus subtilis 3HS12 was increased according to the bacterial density at 40°C.

본 연구에서는 버섯 수확후배지를 바이오매스로 활용하 고자 수행하였으며, 적정 전처리 조건을 구명한 결과는 다음과 같다. 버섯 수확후 배지의 전처리방법 중 알카리 처리가 리그닌 함량을 효과적으로 경감시키면서, 당전환 율이 우수하였고 큰느타리 수확후 배지가 당전환율 80.7%로 가장 우수하였다. 큰느타리 수확후 배지에 1% NaOH를 이용한 알카리 처리시 전처리 온도별 성분분석 결과 120℃처리시에 glucose 25.3%, xylose 14.8%로 유 리당 함량이 가장 높고, 효소에 의한 당전환율도 66%로 무처리구 28.2%에 비해 2.3배 증가되었다. 촉매제 농도 (NaOH 0.5~2.0%)에 따른 당분석결과 glucose 함량은 촉 매제 농도와 관계가 적었으며, xylose와 arabinose는 촉매제 농도가 높을수록 다소 감소하는 경향이었다. 그러나 당전환율은 NaOH 1% 처리시에 66%로 가장 높았다.

The mannanase-producing bacteria, designated YJ17, was isolated from spent mushroom (Flammulina velutipes) substrates. The isolate YJ17 was a facultative anaerobic and was grown at temperatures ranging from 20oC to 50oC with an optimal temperature of 40oC. The DNA G+C content of the YJ17 was 44 mol%. The major fatty acids were anteiso-15:0 (38.9%), 17:0 (7.6%), and iso-15:0 (36.5%). The 16S rRNA gene sequence similarity between the isolate YJ17 and other Bacillus strains was from 98% to 99%. In the phylogenetic analysis based on these sequences, the isolate YJ17 and Bacillus amyloliquefaciens clustered within a group together and separated from other species of Bacillus. Based on the physiological and molecular properties, the isolate YJ17 was classified within the genus Bacillus as B. amyloliquefaciens YJ17. The optimal pH and temperature for mannanase activity of B. amyloliquefaciens YJ17 were pH 7.0 and 50oC, respectively.