• Korean Chemical Engineering Research
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• v.54 no.2
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• pp.248-254
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• 2016

Efficacious wastewater treatment is essential for increasing sewage sludge volume and implementing strict environmental regulations. The operation cost of sludge treatment amounts up to 50% of the total costs for wastewater treatment plants, therefore, an economical sludge destruction method is crucially needed. Amid several destruction methods, wet air oxidation (WAO) can efficiently treat wastewater containing organic pollutants. It can be used not only for sludge destruction but also for useful by-product production. Volatile fatty acids (VFAs), one of many byproducts, is considered to be an important precursor of biofuel and chemical materials. Its high reaction condition has instituted the study of gravity pressure reactor (GPR) for an economical process of WAO to reduce operation cost. Simulation of subcritical condition was conducted using Aspen Plus with predictive Soave-Redlich-Kwong (PSRK) equation of state. Conjointly, simulation analysis for GPR depth, oxidizer type, sludge flow rate and oxidizer injection position was carried out. At GPR depth of 1000m and flow rate of 2 ton/h, the conversion and yield of VFAs were 92.02% and 0.17g/g, respectively.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.80-81
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• 2003

양식 생물의 질병 제어는 예방과 치료를 통해 이루어진다. 그러나 항생제의 오ㆍ남용으로 인하여 약제 내성균의 증가와 치료 효과가 감소하고, 나아가 식품안전성 문제로 양식생물의 소비를 위축시켜왔다. 따라서 질병이 발생한 후에 시행하는 화학약품 치료법은 이미 한계에 달하였다. 이에 따라 사전에 질병을 차단하는 예방법인 vaccine이나 질병에 대한 저항능력을 키우는 비특이적 면역 증강물질에 대한 관심이 꾸준히 높아지고 있다. 해조류에는 다량의 lectin이 포함되어 있는데, Lectin은 당에 결합하는 단백질의 총체적인 이름으로, defence molecule로 작용하여 어류가 섭취할 경우 외래 항원으로 인식하여 지속적으로 면역 기능을 활성화시키는 것으로 알려져 있다. 따라서 본 연구는 돌돔사료에 kelf meal을 첨가하여 공급한 후 이들의 성장과 비특이적 면역기구에 미치는 효과를 조사하였다. 실험사료는 상업용 kelf meal을 0%, 2%, 5% 첨가하고, 2반복으로 500L FRP 탱크에서 8주간 사육하였다. 실험어류는 40g 내외의 돌돔을 대상으로 하였고, 사료공급 4주 및 8주에 각 실험구의 돌돔을 대상으로 비특이적 면역기구에 미치는 효과를 조사하였다. 체액성 면역 조사로는 혈청 및 점액 lysozyme 활성과 Escherichia coli에 대한 혈청 내 보체의 살균 능력을 조사하였고, 세포성 면역 조사는 전신 식세포의 NBT 환원 실험과 말초혈액의 식세포 식균능을 측정하였다. 식균능 시험은 Escherichia coli FKC (formalin killed cell)에 대한 식균율 및 식균지수로 나타내었다. 나아가 돌돔 말초혈액의 혈구조성에 미치는 영향을 조사하기 위하여 적혈구 5,000 세포당 임파구, 전구, 호중구의 수를 계수하였다. 8주간의 사육결과 사료계수는 각각 1.20, 1.25, 1.42로 대조구와 2% 첨가구는 큰 차이가 없었으나, 5% 첨가구는 나빠지는 경향을 보였다. 사료섭취량은 kelf meal의 첨가량이 늘어나면서 감소하는 경향이었다. 비특이적인 면역 기구에 대한 자극 효과는 체액성 면역의 지표로 측정한 lysozyme의 활성도는 혈청과 점액 모두에서 대조구보다 실험구에서 활성이 높았고, 혈청 lysozyme 활성은 5% 첨가구에서 가장 높았다. 혈청 내 보체의 살균능은 실험구간 차이가 없었다. 세포성 면역의 지표로 측정한 전신 식세포의 $O_2$ 생성능(NBT 환원능)은 5% 첨가구에서 가장 높았다. 말초 혈액의 식균능은 식균율과 식균지수 모두 실험구에서 높았고, 특히 5% 첨가구에서 가장 높았다. 말초 혈액 혈구조성의 변화는 임파구와 전구의 경우 실험구에서 높았으나 호중구에서는 차이가 없었다. 이상의 결과, 양식 돌돔에 kelf meal을 2% 첨가하는 것이 사료계수에 큰 영향을 미치지 않고, 돌돔의 체액성 및 세포성 면역을 적절히 자극하는 것으로 나타나, 돌돔의 기능성 사료 첨가물로서 이용 효과가 있을 것으로 기대된다.

• Applied Chemistry for Engineering
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• v.21 no.4
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• pp.445-451
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• 2010

$TiO_2$ shows considerably efficient photoreaction activity under the ultraviolet range but it has disadvantage that there is no activity in the visible light range. In this study, it was tried to find a solution for the problem of this kind of photocatalyst by utilizing transition metal, which can show electronic transition with $TiO_2$ in the visible light area. Photocatalyst was prepared, which can have photocatalytic activity in the wide wavelength range, not only ultraviolet region but also visible light area and prevent the combination of electron and hole hindering the photoreaction. For this purpose, by using the ion exchange method, $TiO_2$ precursor and transition metal precursor were dipped into H typed strong acid ion-exchange resin. And two kind photocatalysts (Ti-M-SCM) in which transition metal and titanium dioxide coexist through the carbonization/activation process was prepared. Moreover, photolytic reaction under the wavelength 254 nm and 365 nm was performed for humic acid (HA) in the continuous reactor in order to estimate the efficiency of produced Ti-M-SCM.

• Journal of Life Science
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• v.30 no.10
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• pp.835-843
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• 2020

Obesity, the world's leading metabolic disease, is a serious health problem in both industrialized and developing countries. Natural substances are of great interest in preventative medicine, especially in the field of metabolic syndromes-from insulin resistance to obesity and diabetes. In the present study, we investigated the effect of A. pullulans SM-2001 Extract (Polycan^®) on the adipocyte differentiation of 3T3-L1 preadipocytes and the anti-obesity effect of 3T3-L1 adipocytes. Although β-glucan has been found to have health benefits in the regulation of the immune system and blood cholesterol levels, its role in obesity has not been fully investigated. Polycan^® suppressed lipid accumulation and glycerol-3-phosphate dehydrogenase (GPDH) activity without affecting cell viability in 3T3-L1 preadipocytes and adipocytes. Polycan^® also inhibited cellular lipid accumulation through down-regulation of transcription factors, such as PPARγ and C/EBPα, and induced dose-dependent phosphorylation of AMP-activated protein kinase (AMPK)-a cellular energy sensor-while the total AMPK protein content remained unchanged. Taken together, this shows that the activation of AMPK by Polycan^® in adipocytes plays a critical role in Polycan^®-induced inhibition of adipocyte differentiation. Our results show that Polycan^® has an anti-obesity action in vitro, suggesting a potential novel preventative agent for obesity and other metabolic diseases.

• Korean Chemical Engineering Research
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• v.51 no.4
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• pp.426-431
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• 2013

Nanosized $TiO_2$ particles were prepared from titanium (IV) sulfate solution using base solutions at low reaction temperature ($95^{\circ}C$) and atmospheric pressure by hydrothermal precipitation method without calcination. The effects of preparation conditions, such as kind of base solutions (NaOH, $NH_4OH$, Monoethanolamine, Diethanolamine, Triethanolamine) and surfactants (CTAB, Span 20, SDBS), concentration of surfactants, temperature and pH, on the physical properties of $TiO_2$ particles have been investigated by XRD, SEM and Zeta-potential meter. Absorption area was also investigated by DRS in order to confirm the photocatalytic activity of the nanosized $TiO_2$ particles. It was turned out that, among base solutions, NaOH provides the smallest $TiO_2$ particles with excellent crystallinity. And cationic surfactant (CTAB) prepared smaller $TiO_2$ particles than any other surfactants. When CTAB is added in the concentration ratio of $Ti(SO_4)_2$:CTAB=10:1, $TiO_2$ particles with particle diameter of 5.8 nm were prepared. This is approximately 1/10 of that prepared without CTAB.

• Korean Journal of Plant Resources
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• v.29 no.1
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• pp.1-10
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• 2016

Obesity is a pro-inflammatory state that contributes to the development of metabolic disorders such as hyperlipidemia, insulin resistance, type 2 diabetes, non-alcoholic fatty liver, and cardiovascular disease. In this study, we evaluated the inhibition of adipogenesis in 3T3-L1 cells and in high-fat diet (HFD)-induced obese mice by Peucedanum japonicum Thunberg L. water extract (PJT). Lipid accumulation measurement indicates that PJT markedly inhibited adipogenesis in a dose-dependent manner. RT-PCR results demonstrated that the mRNA expression of adipogenic transcription factors such as peroxisome proliferator-activated receptor-γ (PPARγ) and CCAAT/enhancer binding protein-α (C/EBPα) in 3T3-L1 cells were significantly down-regulated by PJT treatment. Oral administration of PJT (100, 300, and 500 ㎎/㎏, b.w/daily for 4 weeks) was conducted in high-fat diet induced obese mice and C57BL/6 mice. The PJT-administered group of HFD-induced mice had a lower body weight gain, along with decreased serum levels of glucose, triglycerides, and total cholesterol compared with the control mice, however, the HDL-cholesterol/total cholesterol ratio was increased. Furthermore, the elevated mRNA expression levels of adipogenesis related genes in the white adipose tissue of obese mice were significantly suppressed by PJT. These results indicate that PJT exhibits anti-obesity effects in obese mice by decreasing in serum lipid levels and lipogenesis related gene.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.3
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• pp.373-377
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• 2002

We investigated the quality characteristics of eggs produced from laying hens fed with non-supplemented diets (A) and diets supplemented with 3% (B) and 5% (C) of sea urchin shell powder for efficient applications of sea urchin shell. There was no significant difference in the proximate composition. Ca and Fe contents of (B) and (C) groups were higher than those of (A) group. Contents of phosphorus and magnesium, however, showed no significant differences among the groups. (B) and (C) groups had higher in essential amino acid contents than (A) group except tryptophan. Taurine was detected in all groups. Analysis of fatty acid showed that (B) and (C) groups contained more unsaturated fatty acids. The DHA contents of (A), (B) and (C) groups were 0.56%, 0.68% and 0.89%, respectively. These results show that sea urchin shell possesses the potential as supplement of laying hens diets to produce functional eggs.

• Korean Chemical Engineering Research
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• v.50 no.5
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• pp.808-814
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• 2012

Photocatalytic zinc oxide powders were prepared from precursor zinc acetate and ammonia solution at elevated temperature, $80^{\circ}C$, by hydrothermal precipitation method. The effect of operating parameters, pH of ammonia solution and concentration of zinc acetate solution, on the characteristics of zinc oxide powders were experimentally examined. Zinc oxide powders prepared at the conditions of pH 11, zinc acetate concentration of 1.0 M, precipitation temperature of $80^{\circ}C$, showed smallest average particle diameter of $3{\mu}m$. SEM and XRD analysis confirmed that prepared zinc oxide has hexagonal rods structure, and Anatase type crystallinity. In addition, DRS and PL analysis showed that the zinc oxide has activity at the range of 200~400 nm of UV light. And the zinc oxide decomposed 57% of a food-color stamp Brilliant blue FCF for 3 hours under the UV radiation.

• Journal of Satellite, Information and Communications
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• v.12 no.3
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• pp.54-62
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• 2017

China has invested for military satellite technology development to construct the space-based surveillance system from existing land-based and aerostat surveillance system since 1960s to react rapidly for deployment of marine force of United States and surrounding nations in west Pacific, south China sea and Indian ocean. China has also launched about 40 the Yaogan military intelligence satellites series for EO, SAR and ELINT fields since 2006 after the required technique with several technical experiment satellites launch and operational test. ELINT satellites transmit data from satellite to earth station in real time with construction space-based network around it. Those data are simultaneously delivered to Anti-Ship Ballistic Missile(ASBM) connected land-based C4ISR network for marine target attack. Therefore China has enhanced surveillance and attack capability to the surrounding marine nations with space-based network around it. In the future, It is considered that China will increase accurate location search, signal processing and analysis ability through a further study on its technology.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.220-221
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• 2017

The initial light emitting diode (LED) has been used as a display device for various mechanical devices due to its low power. The development of LED technology has made it possible to express color with high power and high brightness. Therefore, it is used as a display such as a traffic signal, a large electric signboard, and an automobile display, and is also adapted as an indoor or outdoor light source such as an incandescent or a fluorescent lamp which requires the high luminance. The bulb of marine lantern, which is used for the aids to navigation, was replaced to LED. The first marine LED lantern was manufactured using multiple LEDs. However, if the optical design is renewed by the development of LED or even if a few LEDs are used, it is possible to satisfy the brightness and the light distribution required by the marine LED lantern.