The tribology characteristics of the graphene coated PA6 were evaluated with scratch experiments. As a result, the following conclusions were obtained. The PA6 of the graphene coating shows a 0.1 improvement in friction coefficient and a lower abrasion depth than PA6 in the variable pressure-type scratch experiments. PA6 of the graphene coating showed a lower friction coefficient of 0.2 or more than PA6 in the friction coefficient in the static pressure scratch experiments, indicating that wear resistance was improved. In both the variable and the static pressure type scratch experiments, the tip depth of graphene-coated PA6 shows a thinner wear depth than PA6, showing the effect of graphene. The graphene content showed excellent tribology characteristics at 3%, and there was no difference in tribology characteristics at higher contents.

본 연구에서는 뇌혈류 신호를 측정할 수 있는 시변자계 기반의 비접촉식 직물센서를 설계하여 뇌혈류 신호 검출 및 감성평가의 가능성을 탐색하고자 하였다. 직물센서는 40 denier의 은사를 30합사 한 후 컴퓨터 기계 자수하여 코일 형 센서로 구현하였다. 뇌혈류 측정 실험을 위해 코일형 센서를 경동맥 부위에 부착하고, ECG (Electrocardiogram) 전극과 RSP (Respiration) 측정 벨트를 부착 및 착용하도록 하였으며, 동시에 초음파 진단기기를 사용해 도플러 초음 파 검사(Doppler Ultrasonography)를 수행하여 혈류 속도를 측정하였다. 피험자에게 Meta Quest 2를 착용시키고, 실 험을 위해 조작된 영상 시각 자극을 보여주면서 혈류 신호를 측정한 후 시각 자극에 대한 감성평가 설문지를 작성하 도록 하였다. 측정 결과, 도플러 초음파 검사를 통해 측정된 혈류 속도 신호에 변화가 생길 때 직물센서로 측정한 신호도 함께 변화하는 것으로 나타났다. 이를 통해 코일형 직물센서를 이용하여 뇌혈류활동 신호를 측정할 수 있다 는 것을 검증하였다. 또한, 감성평가를 위하여 ECG 신호와 PLL 신호(직물센서 신호)에서 추출한 HRV를 계산해서 비교한 결과, 시각 자극으로 인한 교감신경계와 부교감신경계의 활성화에 따른 비율의 변화에 대해서는 직물센서로 측정한 신호와 ECG 신호를 이용해 계산한 값이 비슷한 경향을 보이는 것으로 나타났다. 결론적으로, 본 연구에서 개발된 시변자계 기반의 코일형 직물 센서를 통해 뇌혈류 변화 측정 및 감성 모니터링이 가능할 것으로 사료된다.

The long-tailed goral (Naemorhedus caudatus) is classified as 'vulnerable' by the International Union for Conservation of Nature and has been designated an endangered species requiring conservation and management in Korea. The sex determination region of the Y (SRY) gene is a useful marker for the study of paternal lineages; however, the SRY gene of the goral has not yet been sequenced. In this study, the nucleotide sequence of the SRY gene of long-tailed gorals was determined based on the sequence of the SRY gene of goats (Capra hircus). The obtained sequences were aligned with those of other species in the Bovidae family. The long-tailed goral SRY gene comprised 720 base pairs, and its nucleotide and protein sequences were identical to those of goats, sheep (Ovis aries), and cattle (Bos taurus) by 96%, 97%, and 93%, respectively. The results of phylogenetic insights obtained from this study constitute important references for genetic diversity and pedigrees studies of male long-tailed gorals and closely related species.

To investigate the anti-inflammatory activity of submerged culture using Cordyceps militaris mycelium, culture-including mycelia was extracted and lyophilized into postbiotics (hot-water extract; CM-HW). HW was fractionated into crude polysaccharide (CM-CP) by ethanol precipitation, and CM-CP was further dialyzed into CM-DCP by dialysis with running water using 12~14 kDa dialysis tube. When the cytotoxicity of subfractions against cells was assessed, no subfraction had a cytotoxic impact that was substantially different from the control groups. In an inflammatory model using LPS-stimulated RAW 264.7 cells, CM-DCP significantly decreased IL-6 and MCP-1 production levels compared to the LPS-control group. CM-DCP also inhibited IL-6 and IL-8 secretion in HaCaT keratinocytes stimulated with TNF-α and IFN-γ. In the meanwhile, the neutral sugar content and mannose ratio of anti-inflammatory CM-DCP were higher than the other fractions, and CM-DCP contained β-1,3/1,6-glucan of 216.1 mg/g. High pressure size exclusion chromatography revealed that CM-DCP contained molecules with a molecular weight range of 5.6 to 144.0 kDa. In conclusion, postbiotics of C. militaris mycelium significantly promoted anti-inflammatory activity, suggesting that neutral polysaccharides including Glc and Man contribute to the anti-inflammation in RAW 264.7 or HaCaT cells.

After liquid culture of Phellinus baumii (P. baumii) mycelium (LPBM) was prepared, LPBM was fractionated into A∼E fraction (A; hot-water extract of liquid culture including mycelia, B; crude polysaccharide of A, C; hot-water extract of mycelia, D; crude polysaccharide of C, and E; crude polysaccharide of culture broth) to evaluate for possibility as functional materials with immunostimulatory activity. In macrophage stimulatory activity, E fraction as postbiotics significantly increased secretion of NO and IL-12 from RAW 264.7 cells. Next, when the splenocytes of C3H/HeN mice were primary cultured, E fraction showed significantly mitogenic activity with enhancing mitogen-related cytokines (IFN-γ and TNF-α) production from splenocyte. E fraction also potently stimulated GM-CSF production from Peyer’s patch cells as well as Peyer’s patch-mediated bone marrow cell proliferation. In addition, the immunostimularoy E fraction contained neutral sugar (73.8%), uronic acid (10.6%), protein (7.8%), and polyphenol (7.5%), and mainly consisted of glucose (39.1%), galactose (21.7%), mannose (11.1%), galacturonic acid (9.9%), and arabinose (8.9%) as component sugars. In conclusion, it was demonstrated that postbiotics including exopolysaccharide fractionated from liquid culture of the P. baumii mycelium could enhanced immunostimulatory activity.

Maca roots (Lepidium meyenii) are an important medicinal herb that have long been used by the Andes-indigenous peoples and South Americans. In Korea, recently, it has attracted attention as a health food material because of nutritional values and physiological activities. The purpose of this study was to investigate the industrial applicability of maca (red and golden varieties; R&G) as immunostimulating materials. In the macrophage stimulating assay using RAW 264.7 cells at 125~500 μg/mL of non-cytotoxicity doses, G-HW showed the most potent production of TNF-α, IL-6 and nitric oxide compared to red maca or the other extracts. The general component analysis results showed that all extracts comprised more than 90% neutral sugars with small amounts of uronic acid and protein. Meanwhile, component sugar analysis showed the difference in the content of uronic acids of cold- and hot-water extract. Additionally, the further fractionation of G-HW into crude polysaccharide (G-CP) greatly enhanced the macrophage stimulating activity, and G-CP contained macromolecules over 144 kDa, comprised mainly of glucose and galacturonic acid (51.0 and 34.9%). In conclusion, crude polysaccharide from maca showed industrial applicability as immunostimulating material, and especially golden maca showed higher macrophage stimulating activity than red maca.

To investigate the industrial availability of liquid fermentation (PL-ferment) by Phellinus linteus mycelium as a postbiotics for the inhibition of inflammation, PL-ferment was fractionated into culture supernatant (CS), hot-water extract (HW) from PL-ferment, EtOH-precipitate (CP) fractionated from HW, and the dialysate (DCP) of CP. Compared to the other fractions, DCP which is expected to contain exopolysaccharide (EPS) as the major component, significantly decreased the production of NO, IL-6, and MCP-1 in LPS-induced RAW 264.7 cells, and IL-6 and IL-8 in TNF-α and IFN-γ-induced HaCaT cells. The general component analysis results showed that no significant difference in components was observed between the fractions, whereas sugar composition analysis revealed that DCP had decreased glucose and increased mannose contents compared to the other fractions. This suggests that mannose played an important role in the anti-inflammatory activity of the active fraction, DCP. Molecular weight distribution analysis revealed that DCP was mainly composed of low-molecular-weight material-removed high-molecular-weight polysaccharides of 18–638 kDa, suggesting that EPS originated from P. linteus EPS. In conclusion, our results suggest that the DCP of P. linteus mycelium fermentation using the anti-inflammatory activity could be used industrially as postbiotic material.

To utilize Malus pruniforia Borkh. as a functional material, cold-water (CW), hot-water (HW), and 70% ethanol (EtOH) extracts were prepared, and their antioxidant and anti-inflammatory activities were compared. The antioxidant activity of the HW extract evaluated by ABTS and DPPH radical scavenging and FRAP activity was significantly effective. The total polyphenol content of the HW extract was also higher by 15.5±0.7 mg GAE/g extract compared to other extracts. The EtOH extract showed significantly decreased TNF-α (39.8%), IL-6 (65.5%), and NO (34.9%) levels in RAW 264.7 cells compared to the LPS-induced control group. The levels of IL-6 (21.1%) and IL-8 (19.3%) were significantly decreased by treatment of EtOH extract in HaCaT keratinocytes induced with TNF-α and IFN-γ. The UHPLC-MS results indicated that the EtOH extract might have chlorogenic acid and phlorizin as the major compounds. This was validated using HPLC-DAD, which showed that the EtOH extract had higher levels of chlorogenic acid and phlorizin (1,185±58 and 470±10 μg/g extract, respectively). In conclusion, the present study suggested that the anti-inflammatory activity of the EtOH extract was more effective than the CW and HW extracts, and chlorogenic acid and phlorizin could be used as indicator compounds and functional substances.

마에는 다양한 기능성 성분이 함유되어 있어서 식용 및 약용으로 다양하게 이용되고 있다. 특히 allantoin은 대표적인 마의 2차 대사산물로서 의약품 및 기능성 화장품 제조에도 활용되는 고부가가치 산물이다. 본 연구에서는 아미노 결합 정지상 HPLC 컬럼을 이용하여 마의 속과 껍질의 allantoin 함량을 분석하였다. Allantoin 표준용액의 검량 선의 결정계수(R2)값은 0.9999로 높은 직진성을 보였으며, 검출한계(LOD)와 정량한계(LOQ)는 각각 0.0229 mg/mL 및 0.0694 mg/mL로 설정되었다. 마 속과 껍질의 건조중량 기준 allantoin 함량은 각각 3.09±0.02 mg/g, 3.91±0.11 mg/g으로 속보다 껍질에 더 많은 allantoin이 함유되어있음을 확인하였다. 따라서 이러한 결과를 토대로 향후 농업부산물인 마껍질이 새로운 고부가가치 기능성 소재로 활용될 수 있음을 확인하였다.

본 연구에서는 20,000 톤급 해양플랜트 상부구조물(Topside)의 플로트오버 설치작업을 위해 개발된 수동형 갑판 지지 프레임 (Deck support frame)의 구조설계에 대해 다양한 실험계획법을 이용한 최소중량설계와 민감도 평가의 비교연구를 수행하였다. 수동형 갑판 지지 프레임의 주요 구조부재의 두께 치수 변수는 설계인자로 고려하였고, 응답치는 중량과 강도성능으로 선정하였다. 최소중량설계와 민감도 평가의 비교연구에 사용한 실험계획법은 직교배열설계법, Box-Behnken 설계법, 그리고 Latin hypercube 설계법이다. 실험계획법의 설계공간 탐색의 근사화 성능을 평가하기 위해 반응표면법을 각 실험계획법 별로 생성하여 근사화 정확도 특성을 검토하였다. 또한 최소 중량설계를 위해 최상 설계안의 결과로 부터 실험계획법의 특성에 따른 수치계산 비용, 중량감소 효과 등을 평가하였다. 수동형 갑판 지지 프레임의 구조설계에 대해 Box-Behnken 설계법이 가장 적합한 설계 결과를 나타내었다.

After ethanol (BM-E and RW-E) and hot-water (BM-HW and RW-HW) extracts were fractionated from two herbal mixtures (BM and RW), their physiological activities were investigated. All extracts consisted of more than 50% of neutral sugar, with their total polyphenol levels higher than flavonoid levels. Radical scavenging activities of EtOH extracts remained significantly higher compared to that of hot-water extracts, and in particular, RW-E showed consistently higher antioxidant activity than BM-E. When anti-inflammatory activities of the extracts were evaluated by LPS-stimulated RAW 264.7 cells at 10~500 μg/mL non-cytotoxicity doses, BM-E showed significantly higher levels of TNF-α, IL-1β, IL-6, and nitric oxide inhibitory activity than those of hot-water extracts and RW-E. Murine peritoneal macrophage cells were shown to be enhanced in crude polysaccharides (BM-CP and RW-CP fractionated from BM-HW and RW-HW) compared to hot-water extracts and polysaccharide K (PSK, positive control). Especially, RW-CP exhibited higher activity than BM-CP, and component sugar analysis showed that BM-CP mainly contained galacturonic acid, glucose, arabinose, galactose, and xylose (34.5%, 33.9%, 16.1%, 7.1%, and 6.3%, respectively), whereas RW-CP showed different measurements (29.5%, 59.2%, 5.0%, 4.5%, and 0.2%). In conclusion, two herbal mixtures could contain varying sets of physiological activities dependent on different extraction and fractionation methods.

Centella asiatica (CA) has been widely used as herbal plants. It is a valuable resources. The aim of the present study was to evaluate physiological activities of solvent extracts from CA cultivated in Chungju, Korea (Good tiger care). After preparing water (cold-water, CA-WE; hot-water, CA-HWE) and EtOH extracts (50% EtOH, CA-50E; 70% EtOH, CA-70E), their total polyphenol, flavonoid, and triterpenoid contents, and anti-oxidant activities, and anti-inflammatory activities were examined and compared. CA-70E showed the most potent anti-oxidant activity based on ABTS radical scavenging activity and reducing ability assays, while CA-50E and CA-70E showed the highest DPPH radical scavenging activity. Among major triterpenoid glycosides present in CA, madecassoside and asiaticoside contents were found to be the highest in CA-70E, and madecassic acid and asiatic acid were the highest in CA-50E. In LPS-stimulated RAW 264.7 cells, CA-70E showed the highest TNF-α inhibitory activity, although CA-50E and CA-70E similarly inhibited nitric oxide production. Ethanol extracts significantly inhibited IL-6 and IL-8 production more than water extracts using TNF-α/IFN-γ-stimulated HaCaT cells, indicating its better inhibitory against skin inflammation. Therefore, Chungju-CA EtOH extract, especially 70% EtOH extract, has high physiologically active ingredients and potent anti-oxidant and anti-inflammatory activities, suggesting its industrial application as a functional material.

The fatty acid binding protein 4 (FABP4) gene plays an important role in lipid metabolism and homeostasis in adipocytes. The objective of this study was to analyze the association between a single nucleotide polymorphism (SNP), g.7516G>C, in the FABP4 gene and economic traits of Korean native cattle, Hanwoo. Primers were designed to target a region of the FABP4 gene between nucleotides 7417 and 7868 (AAFC01136716). The SNP, which was detected by polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) method using restriction enzyme MspA1I, was genotyped in 319 animals of Hanwoo steer population. Statistical analysis showed that the SNP genotype of the FABP4 gene significantly affected carcass weight (CW, p<0.01), longissimus muscle area (LMA, p<0.001), and marbling score (MS, p<0.001). GG allele of the SNP on 246 animals in a Wagyu × Limousin F2 reference population showed a higher MS (p<0.05) and subcutaneous fat depth (p<0.05) in previous report. But CC allele of the SNP showed greater values for MS, LMA, and CW in Hanwoo steers. These results suggest that the g.7516G>C SNP located in the FABP4 gene may affected differently depending on the cattle breed and can be used as a genetic selection marker in Korean native cattle.

In the automotive industry, the platinum titanium anodes (Pt/Ti anode) play a significant role in electroplating of chromium coating on the vehicle’s shock absorber piston rod. In this paper, the structure of Pt/Ti anode was designed to obtain high quality and save time for the electroplating process. The structure of anode was designed in 2D & 3D modeling and analyzed by CATIA and ABAQUS program, respectively. The structural modeling of the anode was analyzed and carried out using a finite element method (FEM) by applied various loads. The manufacture anodes were installed in an electroplating bath in order to test the efficiency of chromium coating on shock absorber piston rod and safety of anode structure. The results presented indicate that the structural analysis is safe after applied loads due to the allowable stress is higher than the maximum equivalent stress about 4 times, and the chromium coating test obtained high-efficiency results.

Defects in most structures can be generated not only on outside but also on inside or on the back-side during the manufacturing or construction process. Also they cause the growth of defects due to operation of various complex environments and structures will be destroyed eventually. In order to improve the reliability of the structure, the detection and size-estimation of defects should be investigated. In this paper, as an extension of previous studies on surface defects, two-dimensional artificial backside cracks (blind cracks) into paramagnetic material were evaluated by using the same aluminum probe. The potential drop at the defect position is distributed in the n-shape in the case of the back defect, which is different from results of the surface defect (u-shape). The potential drops at the defect position are measured with the largest value. The potential drop ratio (Vcmax/Vs) for the defective position is used as a parameter to predict the thickness (l) of defect position.

The long-tailed goral (Naemorhedus caudatus) is an endangered animal species in all its habitats worldwide, including South Korea. The imbalanced sex ratio in fragmented habitats is closely associated with extinction. Therefore, sex identification using wild animal samples would be necessary. However, only a few studies have been reported about the sex identification of gorals. In this study, we thus aimed at comparing the efficiency of sex identification using various goral sample types as templates and the amelogenin (AMEL) and DEAD-box polypeptide 3 (DDX3) genes as target sequences. We extracted DNA from goral feces, tissues, and blood samples, then amplified the AMEL (SE47/SE48 and SE47/SE53 primer pairs) and DDX3 genes for sex identification, comparing the goral DDX3X and DDX3Y target sequences to those in cattle. Our results indicated that the tissue- and blood sample-derived AMEL amplicons showed an unspecific band pattern containing the sex-specific band in the case of both primer pairs we used, whereas the DDX3 amplicon showed only the sex-specific band. In the case of the feces samples, only the sex-specific band was amplified using both the AMEL and DDX3 primer pairs. However, we found that the DDX3 amplicon exhibited a clearer band pattern than the AMEL amplicon. Then, we compared the DDX3X and DDX3Y target sequences between cattle and gorals. We found 5 and 8 nucleotide differences in the DDX3X and DDX3Y sequences, respectively. In conclusion, the DDX3 gene-related sex identification of the long-tailed goral appears to be more efficient and precise than the AMEL gene-related approach. This method could be used for the sex identification of the members of the Bovidae family.

To improve the productivity of shiitake mushroom (Lentinula edodes), seven different types of media for liquid spawn (denoted as “A” to “G”) were prepared with 0.3% soybean meal and varying sugar and glucose concentrations. During 14 days of incubation, the pH of the liquid culture gradually acidified with increasing incubation period. Additionally, there was a significant, but not prominent, difference in the degree of acidification depending on the sugar to glucose ratio. Liquid spawn culture “G,” which had the highest sugar content was the most acidic on the last day of incubation. Mycelium dry weight increased significantly with increasing incubation period, and there was no significant difference in mycelium dry weight irrespective of the sugar to glucose ratio even after 14 days of culture. The inoculation of liquid spawn in sawdust medium with an inoculation volume ≥ 45 mL and incubation period of 15 to 18 days were the optimal culture conditions. Productivity of fruit bodies in sawdust medium and mushrooms treated with liquid spawn was significantly higher compared to solid spawn treatment. The mushrooms treated with liquid spawn had better chewiness, and the free amino acid content, which is associated with savory taste, was higher in these mushrooms compared to those treated with solid spawn.

This study examines the domestic and international bulletproof test standards of armor and plate which are supplied to the domestic market. In addition, improvements and suggestions for the test standard were presented. Experiments were conducted to clarify the distances to the edge, the difference between ammunition makers, and the position of the impact point of the bulletproof plate, which have been discussed in the conventional bulletproof test. As a result of the study, it was confirmed that the bulletproof performance is excellent as the distance from the edge increases. Next, performance differences between ammunition makers were not found. Finally, plates should be applied to the US ESAPI test specification to provide a clear and reproducible test method.

This study was carried out to develop bulletproof helmet with improved bulletproof performance. In modern warfare, the role of personal protection materials in combat is very important because of increase of personal safety. Bulletproof helmets are being developed in the advanced countries in consideration of complex factors such as bulletproof performance improvement and light weight for reducing combat load. In order to develop the bulletproof helmet with improved bulletproof performance to be used in the future, the bulletproof performance test method is presented. The test was carried out under various environmental conditions for the evaluation of the bulletproof helmet.

Most structures require high reliability to ensure safety and soundness. The materials used for these structures are not only defective in the manufacturing process and construction process, but also cause generation and progress of defects due to operation of various complex use environments. In order to improve the reliability of the structure, it is very important to detect and estimate the defect size. The method of evaluating these defects without damaging the structure is a non-destructive method. In this paper, an aluminum probe of AC potential drop(ACPD) method is applied to the evaluation of two-dimensional artificial defects in ferromagnetic materials. Since the potential drop of the defect end is larger than that of the sound area, the defect can be detected and its position can be clearly confirmed, and the potential drops are changed according to the depth of the defect. The potential drop ratio (Vjmax/Vs) of the defective area has a large value for the defect. The relationship between the potential drop ratio (Vjmax/Vs) of 10 kHz and the defect depth can reduce the error in predicting the depth.