Continuous synthesis of high-crystalline carbon nanotubes (CNTs) is achieved by reconfiguring the injection part in the reactor that is used in the floating catalyst chemical vapor deposition (FC-CVD) process. The degree of gas mixing is divided into three cases by adjusting the configuration of the injection part: Case 1: most-delayed gas mixing (reference experiment), Case 2: earlier gas mixing than Case 1, Case 3: earliest gas mixing. The optimal synthesis condition is obtained using design of experiment (DOE) in the design of Case 1, and then is applied to the other cases to compare the synthesis results. In all cases, the experiments are performed by varying the timing of gas mixing while keeping the synthesis conditions constant. Production rate (Case 1: 0.63 mg/min, Case 2: 0.68 mg/min, Case 3: 1.29 mg/min) and carbon content (Case 1: 39.6 wt%, Case 2: 57.1 wt%, Case 3: 71.6 wt%) increase as the gas-mixing level increases. The amount of by-products decreases stepwise as the gas-mixing level increases. The IG/ID ratio increases by a factor of 7 from 10.3 (Case 1) to 71.7 (Case 3) as the gas-mixing level increases; a high ratio indicates high-crystalline CNTs. The radial breathing mode (RBM) peak of Raman spectrograph is the narrowest and sharpest in Case 3; this result suggests that the diameter of the synthesized CNTs is the most uniform in Case 3. This study demonstrates the importance of configuration of the injection part of the reactor for CNT synthesis using FC-CVD.
본 논문에서는 영화에서 인물의 극적인 등장, 등장 인물 간의 관계를 효과적으로 표현하 고자 할 때 주로 사용하는 영화 촬영 기법 ‘아크 트래킹 샷’을 비주얼 노블 게임에 카메라 연출을 설계 및 구현하여 적용하였다. 비주얼 노블은 소설을 읽듯 이야기 진행에 중 점을 둔 게임의 한 장르로 이미지, 사운드 등 시청각적 요소를 첨가하여 이야기의 몰입을 돕는다. 그러나 기존 비주얼 노블의 카메라는 정적이며 움직임이 극히 제한되어 있어 플레이어의 이야기 몰입도를 높이기에는 어려움이 있다. 이를 극복하고자 이야기의 전달이 중요하다는 공통점을 가진 영화의 촬영 기법 아크 트래킹 샷을 3D 게임 엔진에 가상의 카메라 트래킹 레일을 만들고 카메라에 적용하는 과정을 통해 비주얼 노블의 카메라 연출에 적용하였다. 영화 연출 기법을 비주얼 노블 게임콘텐츠에 적용하면서 기존 비주 얼 노블 연출의 단점을 극복하고 역동적인 카메라 움직임은 플레이어에게 몰입을 유지 시키는 작용을 하며 제작자가 전달하고자 하는 감정과 의미를 더욱 효과적으로 전달할 수 있도록 구현하였다.
Human and material resource planning is one representative example of Operations Research. Resource planning is important not only in civilian settings but also in military ones. In the Air Force, flight scheduling is one of the primary issues that must be addressed by the personnel who are connected to flight missions. However, although the topic is of great importance, relatively few studies have attempted to resolve the problem on a scientific basis. Each flight squadron has its own scheduling officers who manually draw up the flight schedules each day. While mistakes may not occur while drafting schedules, officers may experience difficulties in systematically adjusting to them. To increase efficiency in this context, this study proposes a mathematical model based on a binary variable. This model automatically drafts flight schedules considering pilot’s mission efficiency. Furthermore, it also recommends that schedules be drawn up monthly and updated weekly, rather than being drafted from scratch each day. This will enable easier control when taking the various relevant factors into account. The model incorporates several parameters, such as matching of the main pilots and co-pilots, turn around time, availability of pilots and aircraft, monthly requirements of each flight mission, and maximum/minimum number of sorties that would be flown per week. The optimal solution to this model demonstrated an average improvement of nearly 47% compared with other feasible solutions.
The purpose of this study was to develop synbiotic materials and to apply them to the puffed grain products using electrostatic spraying technology. Lactic acid bacteria were isolated from Kimchi and selected through tests of acid resistance, bile salt resistance and γ-aminobutyric acid (GABA) content. The isolated Lactobacillus brevis CFM21 produced highest GABA production up to a concentration of 926.42 μg/mL when grown in MRS broth containing 0.8% MSG. The possibility of coated grains as a prebiotic material was evaluated Confocal laser scanning micro scopy (CLSM). Rice bran extract containing 2% dextrose, 2% soytone, 0.2% potassium chloride, 0.6% MSG was produced 524.77 μg/mL of GABA. Citrus sinensis oil showed the highest antibacterial activity against Clostridium perfringens Electrostatic spray showed much higher effectiveness than conventional spray in coating the puffed grain product through CLSM. Applying Rice bran culture and Citrus sinensis oil to puffed grain product using electrostatic spray could contribute to promote intestinal health of consumers.
한국 땅나리와 섬말나리의 수요는 최근까지도 늘어났지만 종자 상태에서 개화에 이르기까지 확률은 낮은 편으로 자생지에서의 개체수는 해마다 감소하였다. 본 연구는 땅나리(Lilium callosum Siebold & Zucc.)와 섬말나리(L. hansonii Leichtlin ex D.D.T. Moore)의 대량증식을 도모하기 위하여 종자 발아에 유리한 주·야간 온도 조건과 적합한 GA3 농도를 알아보는 것을 목적으로 수행되었다. 땅나리 종자는 2017년 10월 24일 강원도 춘천히 둔산면 원창리(37°47’10.00”N, 127°44’31.00”E), 섬말나리 종자는 2017년 10월 2일 울릉도 울릉군 북면 나리 (37°31’27.06”N, 130°52’25.08”E)에서 채종하였다. 땅나리와 섬 말나리 종자들을 주·야간 15/5, 20/10, 25/15, 20/20°C의 환경 조절상에서 처리구 당 30립씩 3반복으로 치상하여 온도 처리 실험을 진행한 후, 발아율 결과가 가장 우세했던 온도 조건의 환경조절상에서 섬말나리 GA3 처리 실험을 추가로 진행하였다. 온도 처리 실험결과 땅나리는 20/20°C의 온도 조건에서 발아율이 95.0%로 가장 높았으며 평균발아소요일수 또한 10.1일로 가장 낮았다. 섬말나리는 20/20°C의 온도 조건에서 발아율이 78.8%로 가장 높았으며 평균발아소요일수 또한 40.1일로 가장 낮았다. 이를 토대로 20/20°C에서 실시한 섬말나리 GA3 처리 실험은 증류수를 대조구로하여 200, 400, 800mg・L-1의 농도로 상온에서 24시간 침지한 후 처리구 당 20립씩 3반복으로 치상하였다. 그 결과 대조구에서 81.6%로 가장 높은 발아율을 나타냈으며 평균발아소요일수는 200mg・L-1처리구에서 37.1일로 가장 낮았다. 이러한 실험 결과를 바탕으로 땅나리와 섬말나리의 주·야간 발아 최적 온도는 20/20°C이며 GA3 24 시간 처리는 섬말나리 종자 발아에 효과가 없는 것으로 판단 되었다.
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.
Hepatic stellate cells (HSCs) play essential roles in normal and pathophysiological function in liver. In steady state, HSCs contribute to retinoid storage, immune tolerance, and extracellular matrix (ECM) homeostasis. Upon liver injury, they become activated and lead to morphological and functional changes. Studies have demonstrated that activation of HSCs by various stimuli such as toxins, microbial infection, or metabolic overload can promote the fibrotic changes in liver by production of ECM. Herein, we provide current knowledge about the basic characteristics of HSCs and the mechanism by which they are activated.
Cancer is the second leading cause of death worldwide and currently there are many approaches developing towards cancer treatment. Cancer treatments like chemotherapy and radiation therapy are often painful and have adverse effects. The mechanism of apoptosis is a complex process and it involves different pathways in its mechanism of action. Apoptosis can be caused by signals within the cell such as stress, or by extrinsic signals such as ligands binding to cell surface death receptors. The programmed cell death plays a important role in the several physiological and pathological processes. It plays important role in homeostasis. Flavonoids have gained importance as anticancer agents promoting cytotoxicity and apoptosis in cancer cells. Flavonoids are present in many medicinal plants which are a kind of ubiquitous natural products and essential active ingredients. They have strong biological activities with high efficiency and low toxicity, possessing good preventive and cure effects on different tumor forms. Flavonoids such as Scutellarein, Pectolinarigenin and Naringin have reported to possess significant anti-cancer effects on different cancer cell lines till date. In this review, we provide a summary about the anti-cancer effect of the three flavonoids and its mechanisms of action that can be used in future for understanding their potent anti-tumor properties.
The development of drugs from natural plant sources is at growing interest due to the limitations of chemical drugs in terms of side effects and cost-effective factors of natural medicines. Among the various components contained in natural plant materials, flavonoids are of increasing interest because of their extended biological benefits. Flavonoids are classified into various types according to their structure and possess different activities depending on the structure. In this study, the flavonoids contained in Artemisia, native to Korea were examined and reviewed. HPLC chromatograms of three Artemisia species (Artemisia annua L., Artemisia iwayomogi and Artemisia argyi H.) were examined from published sources and their component analysis by MS data were summarized. The various flavonoids of Artemisia were classified into 12 types according to the main structure, and 10 flavonoids based on various activities were examined. The 10 flavonoids were identified as quercetin, kaempferol, rhamnetin, diosmetin, luteolin, methoxyflavone, catechin, apigenin, malvidin and genkwanin with extensive reported studies till date. The ten flavonoids examined have been reported to be effective in preventing and treating various diseases and exhibit activities such as anti-cancer, anti-inflammatory, antioxidant, antiviral, anti-obesity, anti-diabetic and anti-Alzheimer. The collective results from the reported studies suggest that the three types of Korean native Artemisia, contains various flavonoids with beneficial activities and may have therapeutic effects against diseases.
One of the most precise methods of tracking water movement and measuring moisture content during hydration process is the usage of magnetic resonance imaging (MRI). In this study, the target samples were dried “Robusta” green coffee beans, and a series of images was acquired through an MRI system during the entire hydration process. Coffee beans were immersed in a glass bottle and were placed in a 35 mm diameter RF coil throughout the whole experiment. A set of 64 images with a field of view of 26 mm×26 mm was acquired. The hydration process of intact dried green coffee beans lasted for 360 min and image data sets were acquired every 10 min with an optimal GRE pulse sequence developed. The MR images were analyzed in 2D and 3D imaging spaces. The results of 2D analysis showed that the changes in water penetration depth inside coffee beans during the hydration process could be visualized. In addition, the results of 3D analysis presented a clearer understanding of the hydration process of dried coffee beans. This study showed that changes in water distribution and physical dimensions of coffee beans during the hydration process in 2D and 3D imaging spaces were meserable, without disturbing the process, by means of the MRI technique.