The fatigue characteristics of glass fiber reinforced plastic (GFRP) composites were studied under repeated loads using the finite element method (FEM). To realize the material characteristics of GFRP composites, Digimat, a mean-field homogenization tool, was employed. Additionally, the micro-structures and material models of GFRP composites were defined with it to predict the fatigue behavior of composites more realistically. Specifically, the fatigue characteristics of polybutylene terephthalate with short fiber fractions of 30wt% were investigated with respect to fiber orientation, stress ratio, and thickness. The injection analysis was conducted using Moldflow software to obtain the information on fiber orientations. It was mapped over FEM concerned with fatigue specimens. LS-DYNA, a typical finite element commercial software, was used in the coupled analysis of Digimat to calculate the stress amplitude of composites. FEMFAT software consisting of various numerical material models was used to predict the fatigue life. The results of coupled analysis of linear and nonlinear material models of Digimat were analyzed to identify the fatigue characteristics of GFRP composites using FEMFAT. Neuber’s rule was applied to the linear material model to analyze the fatigue behavior in LCF regimen. Additionally, to evaluate the morphological and mechanical structure of GFRP composites, the coupled and fatigue analysis were conducted in terms of thickness.

The Geomunoreum Lava Tube System, declared as a UNESCO World Heritage Site, has a unique natural ecosystem. The information available about this ecosystem, which contains lava caves with secondary carbonate speleothems, is sparse. Hence, extensive research is warranted for establishing a conservation standard. We commenced microbial research on the system and have been studying the microorganisms coating the lava tube wall to acquire fundamental information for understanding the lava cave ecology of Jeju Island. Samples were collected from yellow-colored walls in six caves that are part of the system―the Bengdwi, Utsanjeon, Bukoreum, Manjang, Gimnyeong, and Yongcheon caves. This study focused on yellow walls as it is the most easily distinguished color. According to previous studies, the color of cave walls is attributed to microorganisms or their components. To determine whether the yellow mats from the Jeju lava tube walls are caused by microorganisms, we examined samples at the microscopic scale, by staining mats and analyzing bacterial isolates from glitter particles. As a result, we found that the yellow walls of lava tubes are comprised of microbial mats.

유한요소법(finite element method)은 다양한 분야에서 재료의 역학적 거동을 더욱더 현실적으로 해석하고 예측하는 방법으로 다양한 분야의 제품 개발에 적용되고 있다. 하지만 섬유배향과 변형률 속도가 역학적 특성에 영향을 미치는 유리섬유 강화 플라스틱 복합재료에 관한 수치해석을 이용한 접근 방법은 현재까지 다소 어려움이 있다. 본 연구의 목적은 고분자, 고무, 금속 등과 같은 다양한 복합재료를 위한 선형, 비선형 다중스케일 재료 모델링 프로그램인 Digimat의 수치해석 재료 모델을 활용하여 유리섬유 강화 플라스틱 복합재료의 역학적 특성을 정의하고 검증하는 것에 있다. 또한 이를 통해 좀더 현실 적으로 고분자 복합재료의 거동을 예측하고자 한다. 이를 위해 다양한 고분자 중 30wt%의 단섬유 질량 비율을 갖는 폴리부 틸렌 텔레프탈레이트(polybutylene terephthalate, PBT)의 섬유배향과 변형률 속도에 따른 인장 특성을 참고문헌을 통해 조사하였다. 또한 Moldflow 프로그램을 사용한 사출해석을 통해 유리섬유 배향 정보를 계산하였으며 이를 매핑(mapping) 과 정을 통해 유한요소 인장 시편 모델에 전달하였다. 대표적인 유한요소 상용 프로그램 중 하나인 LS-DYNA는 유리섬유 배향과 변형률 속도에 따른 복합재료의 인장 특성을 연구하기 위해 Digimat과의 연성해석(coupled analysis)에 활용되었다. 그리고 유리섬유 강화 플라스틱 복합재료를 해석하기 위한 LS-DYNA의 다양한 비등방성(anisotropic) 재료 모델들의 장단점을 서로 비교하고 평가하였다.

The purpose of this study was to investigate and analyze the total phenolic content (TPC), antioxidant activities (FRAP, ABTS, and DPPH), and antibacterial properties of lotus (Nelumbo nucifera) extracts. Lotus leaves, stems, and seed pods were extracted with deionized water at 95℃, and with 70.5% ethanol at 85℃. The TPC ranged from 8.12 to 215.12 GAE mg/g. The ethanol extract of the seed pod had the highest TPC, and the TPC of the corresponding deionized water extract was 161.45 mg/g. FRAP values ranged from 104.03 to 3,546.39 TEAC μmol/g, ABTS radical cation scavenging activities ranged from 105.11 to 3,956.94 TEAC μmol/g, and DPPH radical scavenging activities ranged from 37.29 to 2,549.46 TEAC μmol/g. EC50 values ranged from 0.26 to 9.63 mg/mL, and 0.31 to 21.21 mg/mL for ABTS and DPPH, respectively. The ethanol and deionized water extracts of the seed pod showed higher TPC and stronger antioxidant properties (FRAP, ABTS, and DPPH) than those of characteristic of the leaf extracts. The ethanol and deionized water extracts of the seed pod showed antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, and Pseudomonas aeruginosa with inhibition zones of 9.0 to 14.0 mm, and the ethanol extract of the leaf showed antimicrobial activity against B. subtilis and S. aureus with inhibition zones of 9.0 and 10.0 mm, respectively. Thus, the lotus seed pod could be used to produce novel teas, and could be a potential source of therapeutic ingredients for food and medicine.

Agricultural production is the most important sector, because it supplies human food, clothing, medicine, employment, etc. In order to promote development as well as investigation into agriculture, it is critical to master into any agricultural systems all over the world. This study is to capture comprehensive understanding on the status of Vietnam’s agricultural production, trade and policies. Vietnam is an agricultural country with a long history of Wet Paddy Civilization where agriculture sharing 35.1% of land area, employing 42% of labors and contributing up to 17% of total 196.3 - billion$ GDP in 2015. During the last 30 years of implementing Doi Moi Policy, a market orientation reform. Vietnam has achieved remarkable results for ensuring national as well as global food security, eliminating hunger, alleviating poverty. The country has transformed from one of the world’s poorest to a lower middle-income country (1,990 $/capita in 2015) with high exporting quantities of agricultural products for being the world largest exporter of cashews nut and black pepper, the second largest exporter of coffee and cassava, and the third largest exporter of rice in 2013. The nation has boosted its international economic integration with more than 100 different trading partners all around world, which has provided a further catalyst for national economic development. However, the country is still facing with many challenges in agricultural production. Hence, the country has made big efforts to restructure its agriculture. Production is oriented towards agriculture commodities with intensive cultivation and specialization to boost productivity and quality, using more machinery, agricultural materials, high technologies, and agriculture associated with industrial processing and agricultural services.

In this study, we analyzed the biochemical factors in lotus (Nelumbo nucifera) leaf, stem, and yeonjabang and their effects on serum factor levels in mice fed a high-fat (HF) diet. The loutus leaf showed 9.47±0.30% moisture content, 8.25±0.39% ash, 21.45±1.25% crude protein, and 2.21±0.13% crude fat content; the lotus stem showed 11.84±0.43% moisture, 10.21±0.64% ash, 17.55±0.92% crude protein, and 4.16±0.23% crude fat content; and the lotus yeonjabang showed 11.86±0.50% moisture, 6.81±0.51% ash, 18.71±1.02% crude protein, and 3.95±0.15% crude fat. Blood triglyceride levels were higher in the HF group (146.43±38.81 mg/dL), and lower in the HF+yeonjabang groups (98.00±17.18 mg/dL). In particular, blood triglyceride levels were significantly lower in the groups that had 10% dry yeonjabang powder added to the high-fat diet. The inclusion of excessive high-fat diet increased concentrations of serum insulin and leptin. Serum leptin concentrations were highest in the HF group mice (3.00±1.35 ng/dL), whereas they were significantly lower in the HF+yeonjabang groups by 1.34±0.52 ng/dL (p<0.05). Thus, addition of dry yeonjabang powder to the high-fat diet was more effective in regulating the levels of serum triglycerides and leptin in mice. Additional studies would help in the development of yeonjabang as a functional food.

In this study, we determined the effect of the mulberry leaf powder on blood lipid metabolism and liver function improvement of mice fed a high fat diet. The mulberry leaf showed a moisture content of 10.74±0.56%, ash 9.67±0.56%, crude protein 25.24±1.02%, and crude fat 2.66±0.08%. In the group with high fat diet supplemented with mulberry leaf powder, serum low-density lipoprotein (LDL-cholesterol) and total cholesterol levels were significantly lower (p<0.05); also, serum phospholipid and aspartate amino transferase (AST) levels were significantly lower (p<0.05). Serum insulin and leptin levels were high in mice fed a high fat diet; however, addition of mulberry leaf powder 10% in the diet had no significant effect on blood insulin and leptin control. The results of the study suggested that various plant sterols in mulberry leaf improve lipid metabolism and liver function in ICR-mice.

This study analyzed the antioxidant properties of Equisetum arvense and its effects on serum factor levels in mice fed a high-fat diet. The aim was to establish a new effective resource for biologically active materials. E. arvense stem and root extracts were obtained using deionized water at 95℃, and 70.5% ethanol at 85℃. These extracts were used to analyze the total phenolic compounds and antioxidant (ABTS, DDPH, and FRAP) activities. The effects of prepared ground samples were evaluated by feeding them to mice. E. arvense extracts showed strong antioxidant effects. The caffeic acid content was highest in the 70.5% ethanol extract of the vegetative stem, as determined by high-performance liquid chromatography. The blood concentrations of insulin and leptin were significantly lower in mice fed a high-fat diet supplemented with extracts of the root, reproductive stem, and vegetative stem of E. arvense than in mice fed only a high-fat diet. These results suggest that the polyphenolic compounds in E. arvense extracts exert various antioxidant effects. The stems and root of E. arvense can lower the blood levels of insulin and leptin, even after consumption of a high-fat diet.

This study was conducted to verify the effects of Erigeron annuus powder on serum lipid levels of high-fat diet-induced mice from a nutritional viewpoint. Erigeron annuus powder has been used as a folk remedy since ancient times in Korea. There was no significant difference in the weight of the kidneys and spleens of the mice. The high-fat diet group had a significantly higher kidney weight compared to other groups (p<0.05). In the group of mice fed 20% Erigeron annuus powder with a high-fat diet, the concentration of serum LDL-cholesterol was high (p<0.05), whereas the concentration of triglyceride was remarkably lower compared to other groups (p<0.05). The group fed 10% Erigeron annuus with a high-fat diet had the lowest concentration of blood phospholipids (p<0.05) as well as the highest alkaline phosphatase and alanine aminotransferase levels in blood (p<0.05). There was no difference in blood insulin concentration. However, blood leptin concentration was significantly higher (5.88±3.53 ng/dL) in mice fed a high-fat diet compared to other groups (p<0.05). Measurements of Erigeron annuus revealed that TPC, ABTS+ radical scavenging activity of trolox, DPPH radical scavenging activity, and the measured value of FRAP were higher in the ethanol extract than in the water extract. Especially, the antioxidant activity effects were excellent for the ABTS+ radical scavenging activities of trolox and FRAP values of Erigeron annuus. Therefore, Erigeron annuus powder showed antioxidant activity. Hence, Erigeron annuus powder drastically lessened triglyceride concentration in blood in high-fat diet-induced mice. Thus, the powder is considered to have utility in the food processing industry. Additional related experiments are ongoing.

Since Korean ancient times, powder of Rosa rugosa Thunberg has been used as a folk remedy. This study was conducted to verify the effects of Rosa rugosa Thunberg powder on in vitro antioxidant properties and serum lipid levels of high-fat diet-induced mice from a nutritional viewpoint. In the case of Rosa rugosa Thunberg powders, measurement of TPC, ABTS radical scavenging activity of trolox, DPPH radical scavenging activity, and measured value of FRAP were higher in ethanol extract than water extracts. For LDL-cholesterol concentration, mice fed 10% powder of Rosa rugosa Thunberg with high-fat diets showed a high numerical value compared with other groups (p<0.05). When testing for triglyceride concentrations in blood, mice fed 10% and 20% powder of Rosa rugosa Thunberg with high-fat diets showed the lowest numerical values (p<0.05). When testing for blood insulin concentrations, the high-fat diet group showed higher levels than compared to the control group (p<0.05). When testing for blood leptin concentrations, the high-fat diet group was 5.88±3.53 ng/dL, whereas mice fed 10% powder of Rosa rugosa Thunberg with high-fat diets showed a blood leptin level of 10.36±5.96 ng/dL (p<0.05). Therefore, results prove that powder of Rosa rugosa Thunberg reduces triglyceride concentrations in the blood, and could be used as an excellent natural antioxidant in the future.

본 연구는 ICR-mouse를 실험군당 5마리를 공시하여 식이에 산벚나무 씨앗 기름 및 옥수수 기름을 첨가하여 배합한 사료의 섭취가 쥐의 혈중 지질 수준에 미치는 영향을 비교․ 분석하였다. 1. 산벚나무 씨앗에는 palmitic acid, oleic acid 및 linoleic acid 등이 함유되어 있으며, linolenic acid와 erucic acid가 소량 함유되어 있다. 2. 산벚나무 씨앗 기름의 항산화 값(DPPH)은 4.63%로 나 타났으며, 신장의 무게는 다른 두 군에 비해 산벚나무 씨앗 기름을 섭취한 군(1.24±0.22 g)에서 유의적으로 높았다(p<0.05). 3. 산벚나무 씨앗 기름을 섭취한 군에서 HDL-cholesterol 농 도는 가장 높았으며, 혈중 LDL-cholesterol 농도는 가장 낮았 다(p<0.05). 이상의 결과를 정리해 보면, 산벚나무의 씨앗 기름의 지방 산 조성은 다른 식물성 씨앗 등의 지방산 조성과 큰 차이가 없었으며, 혈중의 HDL-cholesterol 농도를 높여주는 반면에, LDL-cholesterol 농도는 낮추어 주는 것으로 나타났다. 따라서 산벚나무의 씨앗 기름을 현재 유지 자원으로 사용되고 있는 참깨나 들깨와 같이 식용유지 자원으로 개발하기 위해서는 Choi 등(2012)의 연구에서 지적했듯이 씨앗 기름의 항산화 효과, 산패 진행 정도 및 인체에 미치는 영향 등의 지속적인 연구가 이루어져야 한다고 사료된다.

북방한계선(NLL: Northern Limit Line, 이하 NLL이라 한다)은 1953년 8월 30일 마크 클라크(Mark W. Clark) 유엔군 총사령관이 설정하였다. NLL은 60년 동안 북한군과 우리군 사이의 군사적 긴장을 방지하는 효과적인 수단으로 기여해 왔고, 군사력을 분리하는데 기여해 온 실질적인 경계선으로 역할을 해왔다.NLL 설정 이후, 북한은 1973년부터 경비정을 의도적으로 침범시켜 ‘현상 타파’를 시도해왔다. 특히 2000년대 이후, 북한은 군사적 협상과 군사적 도발을 병행하여 서해 NLL의 무실화를 수시로 시도해 왔다. 그러나 서해 NLL은 북한의 수차례 도발에도 불구하고 우리 해군이 온갖 희생을 감수하며 지켜온 실질적인 해상경계선이다. 또한 서해 NLL은 정전협정, 남북기본합의서, 유엔해양법협약, 국제법에 따라 법적 유효성을 가지고 있으며, 우리나라의 관할권 하에 있다.따라서 본 논문은 서해 NLL과 관련하여 우리군이 북한군과 군사협상을 대비하도록 대응논리를 제공하고 북한의 군사적 도발을 대비하도록 수호방안을 제공하고자 한다.

In this study, the effects of intake of Acer mono Max. seed oil, and Magnolia denudata seed oil on the lipid levels of mouse blood were compared to those of commercially available vegetable oils. FiveICR mice were each fed a corn oil, Acer mono Max. seed oil, and Magnolia denudata seed oil supplemented diet for a total of 8 weeks. The serum profiles of mice fed Acer mono Max. seed oil and Magnolia denudata seed oil were high in palmitic acid, oleic acid, and linoleic acid. The saturated fatty acid contents of mice fed Acer mono Max. seed oil and Magnolia denudata seed oil were 3.95% and 0.88%, whereas the unsaturated fatty acid contents were 8.71% and 4.60%, respectively. The liver and spleen weights of mice fed Acer mono Max. seed oil were higher than those fed corn oil (p<0.05). Total cholesterol level was highest in mice fed Acer mono Max. seed oil (p<0.05), whereas there were no significant changes in the cholesterol levels of mice fed Magnolia denudata seed oil and corn oil. The HDL-cholesterol levels in mice fed Acer mono Max. seed oil (175.80±27.66 ㎎/㎗) and in those fed Magnolia denudata seed oil (145.20±19.10 ㎎/㎗) were higher compared to those of mice fed corn oil (p<0.05). In conclusion, there were no significant differences in fatty acid composition between mice fed Acer mono Max. seed oil and Magnolia denudata seed oil. Future study on the antioxidant effects of seed oils should be carried out.

선행 연구에서 형질전환 모상근 대량생산 최적배지 선발을 통해 WPM(Woody Plant basal salt Mixture) 배지가 형질전환 모상근 대량생산의 최적배지임을 확인할 수 있었다(Kim et al., 2012). 이에 당, 탄소원, pH, 무기염, 식물 호르몬 등이 형질전환 모상근의 수량성에 미치는 연구를 통해 최적의 형질 전환 모상근 대량생산 조건을 확립한 결과는 다음과 같다. 1. 형질전환 모상근 대량생산에 적합한 pH는 7.0이었으며, 최적의 탄소원과 농도는 1%의 sucrose임을 확인하였다. 2. 형질전환 모상근 대량생산에 적합한 적정 무기염들 (KH2PO4,NH4NO3, KNO3)의 농도는 KH2PO4 경우 MS배지와같은 농도인 0.94 mM에서 수량성이 303 g으로 가장 높았고, NH4NO3 및 KNO3 농도는 MS배지 농도의 1/4배인 3.87 mM, 3.52 mM 처리가 345 g과 358 g으로 수량성이 가장 높았다. 3. 형질전환 모상근 대량생산에 있어 식물생장조절물질 NAA, IBA의 최적 농도는 무처리 경우가 각각 595 g과 402 g으로 수량성이 가장 높아 대량생산에는 식물생장조절물질 처리가 필요 없을 것으로 판단되었다.

Guillain-Barré syndrome (GBS) is the most common cause of acute flaccid paralysis and autoimmune polyradiculoneuropathy. Campylobacter jejuni is the most commonly identified infectious trigger for GBS. A sialic-acid containing lipopolysaccharide (LPS) of Campylobacter is thought to be involved in the triggering of GBS. The galE (UDPgalactoset- epimerase) gene of Campylobacter spp. is involved in the synthesis of LPS. In this study, we detected the galE gene in Campylobacter spp. responsible for triggering the onset of GBS. The PCR assay detected the presence of the gene in 14 of the 25 (56%) Campylobacter isolates from domestic chicken, 20 of the 28 (71.4%) Campylobacter isolates from imported chicken and 50 of the 51 (98%) Campylobacter isolates from human clinical samples. Also, the specific 497-bp region of galE sequence in Campylobacters responsible for triggering the onset of GBS was amplified from GBS patient. These results could provide evidence of the first GBS-related C. jejuni infection in Korea.