One of the key challenges for the commercialization of carbon nanotube fibers (CNTFs) is their large-scale economic production. Among CNTF spinning methods, surfactant-based wet spinning is one of the promising techniques for mass producing CNTFs. Here, we investigated how the coagulation bath composition affects the spinnability and the properties of CNTFs in surfactant-based wet spinning. We used acetone, DMAc, ethanol, and IPA as coagulants and analyzed the relationship between coagulation bath composition and the properties of CNTFs in terms of kinetic and thermodynamic coagulation parameters. From a kinetic perspective, we found that a low mass transfer rate difference (MTRD) is favorable for wet spinning. Based on this finding, we mixed the coagulant bath with solvent in a proper ratio to reduce the MTRD, which generally improved the wet spinning. We also showed that the coagulation strength, a thermodynamic parameter, should be considered. We believe that our research can contribute to establishment of surfactant-based wet spinning of CNTFs.
In this work, we investigated the photo-degradation performance of MnO2-SiC fiber-TiO2 (MnO2-SiC-TiO2) ternary nanocomposite according to visible light excitation utilizing methylene blue (MB) and methyl orange (MO) as standard dyes. The photocatalytic physicochemical characteristics of this ternary nanocomposite were described by X-ray diffraction (XRD), scanning electron microscopy (SEM), tunneling electron microscopy (TEM), ultraviolet-visible (UV-vis), diffuse reflectance spectroscopy (DRS), electrochemical impedance spectroscopy (EIS), photocurrent and cyclic voltammogram (CV) test. Photolysis studies of the synthesized MnO2-SiC-TiO2 composite were conducted using standard dyes of MB and MO under UV light irradiation. The experiments revealed that the MnO2-SiC-TiO2 exhibits the greatest photocatalytic dye degradation performance of around 20 % with MB, and of around 10 % with MO, respectively, within 120 min. Furthermore, MnO2-SiC-TiO2 showed good stability against photocatalytic degradation. The photocatalytic efficiency of the nanocomposite was indicated by the adequate photocatalytic reaction process. These research results show the practical application potential of SiC fibers and the performance of a photocatalyst composite that combines these fibers with metal oxides.
The steamed and freeze-dried mature silkworm powder (SMSP) is developed by the Rural Development Administration (RDA) in 2012. In here, the nutritional components of SMSP produced by rearing white-silk cocoon silkworm, Baekokjam, at high temperatures were compared and analyzed with those produced under optimal temperature conditions of 25°C. The weight of silkworms reared in a high-temperature environment increased compared to that under an optimal condition. However, when the silkworms matured, the difference in weight according to temperature conditions narrowed. As for the growth rate, the 5th instar silkworms grew a day earlier in a high-temperature environment than in an optimal. SMSPs produced in a high-temperature environment showed a difference when comparing the nutritional components with the SMSPs in an optimal condition. Overall, high-temperature-reared SMSPs contained about twice as high carbohydrates and slightly lower protein and fat than the optimal-reared SMSPs. These results show that SMSPs produced in a high-temperature environment have a difference in growth rate and nutritional composition from those produced under an optimal condition.
The separation of hydrogen isotopes is a critical issue in various fields, such as deuterium or tritium production and the treatment of radioactively contaminated water. In this presentation, we describe the pervaporative separation of hydrogen isotopes using proton conductive membranes and underlying separation mechanism. We investigated the H/D separation factors of perfluorosulfonic acid (Nafion) and polybenzimidazole membranes using pervaporation, and found that both membranes exhibited similar separation factors of approximately 1.026. Water permeation flux through the membranes was highly dependent on their thickness and type, and increased with operation temperature. However, the effect of temperature on H/D separation factor was negligible. We also demonstrated the cascade separation of H/D, indicating the potential application of multi-stage operation. We found that surface transport mechanisms such as hydron hopping contributed the most to H/D separation during the pervaporation process of proton conductive membranes.
국내 현대정원의 조성 디자인 경향성을 확인하고자 우수 경 관 정원 80개소 대상으로 적용 양식 및 정원 식물을 조사하였 다. 조사 대상 80개소 정원 중 53.7%는 서울 및 수도권, 46.3%는 그 외 지역에 소재하고 있다. 또한, 관리 유형에 따 라 공동 정원, 상업시설 정원, 개인 정원으로 구분 되었으며, 각 62.5%, 21.3%, 16.2%로 나타났다. 19~20세기 해외 정원 사조에 따라 조성 양식은 12유형(정형식, 비정형식, 정형 및 비정형 복합식, 건축식, 자연, 신풍경, 뉴저먼 스타일, 모더니 즘, 프레리 스타일, 뉴웨이브 스타일, 낭만주의, 예술작품 정 원)으로 분류되었다. 우리나라 현대 정원은 단일 및 복합 양식 활용이 각 55.0%와 45.0%로 유사하였다. 주로 정형 및 비정 형 복합식 정원이 활용되는 반면, 정형 및 비정형 복합식 정원 대비 낭만주의, 모더니즘, 프레리 및 뉴웨이브 스타일 이용 빈 도는 0.02~0.06배 수준이었다. 조성 양식 활용에 따라 이용 되는 식물 소재 유형에는 큰 차이가 없었으나, 특정 디자인에 서 식재 빈도가 높은 분류군을 확인했다.
Hydrogen isotopes (H, D, T) separation technologies have received great interest for treatments of tritiated liquid waste produced in Fukushima. In addition, the separated deuterium and tritium can be utilized in various industries such as semiconductors and nuclear fusion as expensive and rare resources. However, separating hydrogen isotopes in gas and liquid forms still requires energyintensive processes. To improve efficiency and performance of hydrogen isotope separation, we are developing water electrolysis, cryosorption, distillation, isotope exchange, and hydrophobic catalyst technologies. Furthermore, an analytical method is studied to evaluate the separation of hydrogen isotopes. This presentation introduces the current status of hydrogen isotope research in this research group.
계절에 따른 정원의 경관 변화 특성을 알아보고자, 우수 정 원 4개소를 대상으로 계절별 식재 특성과 색채 변화를 분석하 였다. 대상 정원에서 계절별로 조사된 식재 종수 합은 346분 류군이었고, 교목:관목:초본의 식재 백분율(%)은 8:21:71로 나 타났다. 초본은 봄을 기준으로 여름과 가을에 각각 6%와 15% 증가하였다. 관목은 봄에서 가을까지 계절 변화에 따라 64-100% 증가하였다. 계절에 따라 정원의 포인트 식물이 달라 졌으나, 꽃이 만발하는 초본과 관목으로 나타났다. 색채 분석 결과, 정원의 주조색은 식물 생육이 왕성한 봄과 여름에는 녹 색에서 짙은 녹색으로 나타났고, 가을에는 갈색으로 확인되었 다. 강조색은 계절에 따라 분명하게 달라졌으며, 주로 계절별 특징적인 화색이나 잎무늬로 결정되었다.
Background: Although various conventional approaches have been employed to reduce spasticity in neurological rehabilitation, only a few studies have shown scientific evidence for its effectiveness. Thus, we introduced a different concept (Ueda method) of rehabilitation therapy that can complement the limitations of conventional therapy.
Objects: This study aimed to investigate the immediate effects of the application of the Ueda method on patients with spasticity after stroke via an electrophysiological study.
Methods: We conducted a randomized double-blind pilot study in two rehabilitation hospitals involving 30 stroke patients who were randomly allocated to the Ueda (n = 15) and convention (n = 15) groups. Electromyographic data of six examined muscles in both upper extremities of all patients were recorded. The A-ApA index and activation ratios of upper extremity muscles were evaluated and compared between the groups to confirm post-intervention changes in upper-extremity flexor spasticity and flexion synergies. Repeated-measures analysis of variance was conducted to confirm the therapeutic effect (2 × 2) as a function of group (Ueda vs. convention) and time (pre-/post-intervention) on all outcome measures (p < 0.05).
Results: In the Ueda group, the mean A-ApA index values differed significantly before and after the intervention (p = 0.041), indicating a weak evidence level; however, the effect size was medium (d = –0.503). The interaction effects of the A-ApA index between the Ueda and convention groups and between pre-intervention and post-intervention stages were significant (p = 0.012). The effect size was large (np 2 = 0.220). In the Ueda group, the activation ratios of the anterior deltoid fiber significantly decreased after the intervention in all reaching tasks.
Conclusion: The Ueda method reduces upper-extremity flexor spasticity and changes its synergy in stroke patients and should be considered a rehabilitation therapy for spastic stroke patients.
Forage crop management is severely challenged by global warming-induced climate changes representing diverse a/biotic stresses. Thus, screening of valuable genetic resources would be applied to develop stress-tolerant forage crops. We isolated two NAC (NAM, ATAF1, ATAF2, CUC2) transcription factors (ANAC032 and ANAC083) transcriptionally activated by multi-abiotic stresses (salt, drought, and cold stresses) from Arabidopsis by microarray analysis. The NAC family is one of the most prominent transcription factor families in plants and functions in various biological processes. The enhanced expressions of two ANACs by multi-abiotic stresses were validated by quantitative RT-PCR analysis. We also confirmed that both ANACs were localized in the nucleus, suggesting that ANAC032 and ANAC083 act as transcription factors to regulate the expression of downstream target genes. Promoter activities of ANAC032 and ANAC083 through histochemical GUS staining again suggested that various abiotic stresses strongly drive both ANACs expressions. Our data suggest that ANAC032 and ANAC083 would be valuable genetic candidates for breeding multi-abiotic stress-tolerant forage crops via the genetic modification of a single gene.