• Journal of Animal Science and Technology
• /
• 제63권4호
• /
• pp.919-933
• /
• 2021

We hypothesized that the unsaturated fatty acid palmitoleic acid (POA) could promote the expression of adipogenic/lipogenic genes in bovine skeletal muscle satellite cells (BSCs). The BSCs were cultured in a growth medium containing 10% fetal bovine serum. When the cells reached 80%-90% confluence, we used the differentiation medium with 5% horse serum for differentiation for 96 h. The differentiation medium contained 50 µM, 100 µM and 200 µM POA. Control BSC were cultured only in differentiation media. Compared with the control BSC, the POA BSC significantly up-regulated the expression of paired box 3 (Pax3) and paired box 7 (Pax7) and down-regulated myogenin gene expression (p < 0.01), which indicates a depression in muscle fiber development. However, all POA treatments up-regulated the expression of the adipocyte transcription factors peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein alpha and beta (C/EBP α and C/EBP β), and other genes (p < 0.01) and increased the expression of PAT-family proteins and the concentration of adiponectin in the media. These results indicate that POA can convert part of BSCs into adipocytes.

• Journal of Animal Science and Technology
• /
• 제63권4호
• /
• pp.934-953
• /
• 2021

Ciglitazone is a member of the thiazolidinedione family, and specifically binds to peroxisome proliferator-activated receptor-γ (PPARγ), thereby promoting adipocyte differentiation. We hypothesized that ciglitazone as a PPARγ ligand in the absence of an adipocyte differentiation cocktail would increase adiponectin and adipogenic gene expression in bovine satellite cells (BSC). Muscle-derived BSCs were isolated from six, 18-month-old Yanbian Yellow Cattle. The BSC were cultured for 96 h in differentiation medium containing 5 µM ciglitazone (CL), 10 µM ciglitazone (CM), or 20 µM ciglitazone (CH). Control (CON) BSC were cultured only in a differentiation medium (containing 2% horse serum). The presence of myogenin, desmin, and paired box 7 (Pax7) proteins was confirmed in the BSC by immunofluorescence staining. The CL, CM, and CH treatments produced higher concentrations of triacylglycerol and lipid droplet accumulation in myotubes than those of the CON treatment. Ciglitazone treatments significantly increased the relative expression of PPARγ, CCAAT/enhancer-binding protein alpha (C/EBPα), C/EBPβ, fatty acid synthase, stearoyl-CoA desaturase, and perilipin 2. Ciglitazone treatments increased gene expression of Pax3 and Pax7 and decreased expression of myogenic differentiation-1, myogenin, myogenic regulatory factor-5, and myogenin-4 (p < 0.01). Adiponectin concentration caused by ciglitazone treatments was significantly greater than CON (p < 0.01). RNA sequencing showed that 281 differentially expressed genes (DEGs) were found in the treatments of ciglitazone. DEGs gene ontology (GO) analysis showed that the top 10 GO enrichment significantly changed the biological processes such as protein trimerization, negative regulation of cell proliferation, adipocytes differentiation, and cellular response to external stimulus. Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that DEGs were involved in the p53 signaling pathway, PPAR signaling pathway, biosynthesis of amino acids, tumor necrosis factor signaling pathway, non-alcoholic fatty liver disease, PI3K-Akt signaling pathway, and Wnt signaling pathway. These results indicate that ciglitazone acts as PPARγ agonist, effectively increases the adiponectin concentration and adipogenic gene expression, and stimulates the conversion of BSC to adipocyte-like cells in the absence of adipocyte differentiation cocktail.

• 한국해양공학회지
• /
• 제11권3호
• /
• pp.8-19
• /
• 1997

In this study an adequate type of offshore structure at the Sakhalin region as cold region is proposed and its structural design results are presented based on the reliability analysis. Structural safety assessment has been carried out for the proposed offshore structure at the Sakhalin area as designed by the reliability method. And a rational design procedure is presented based on the reliability analysis. Followings are drawn through the present study : - Four colum TLP structure is proposed as an adequate offshore structure type at the cold region like the Sakhalin region and the reliability-based structural design results are presented. It is seen that the proposed type is a more adequate and economic than the fixed type. - Safety assessment of the proposed structure applying the extended incremental load method is performed. - Referring the allowable safety level for offshore structures it has been found present TLP structure has sufficient structural safety at the system level as well as at the component level.

• 열처리공학회지
• /
• 제27권2호
• /
• pp.59-64
• /
• 2014

Cu-Al-Mn shape memory alloys of a variety of composition were characterized in terms of shape memory properties and cold workability. Cold workability tested by cold rolling indicated that the alloys solution treated in the ${\alpha}+{\beta}$ region have a higher ductility than those solution treated in the ${\beta}$ region. Also it is known that cold workability increased with the decrease in Al content in the ${\beta}$ region. This seems to be resulted from the fact that Mn addition causes to expand ${\beta}$ region toward lower Al content and lower order-disorder transition temperature, consequently, ${\beta}$ of excellent workability being frozen even at room temperature. Experimental results regarding shape memory showed that the properties were better with a higher Al contents at a given Mn content, which is closely related with martensitic transformation. It is also shown that super elasticity limit was enhanced with decrease in the yield strength of alloys because a lower yield strength seems to initiates slip at the lower applied stress.

• Journal of Advanced Marine Engineering and Technology
• /
• 제27권3호
• /
• pp.340-355
• /
• 2003

본 해설에서는 현재 및 앞으로도 그 중요성과 필요성이 점차적으로 강조되고 있는 재료들에 대한 특성들에 대해 해설하고자 하였다. 다양한 형태의 구조물에 사용되고 있으며. 그에 대한 연구와 개발이 끊임없이 진행되고 있는 각각의 재료들에 대한 저온과 같은 극한 환경 조건에서의 충분한 지식을 터득하고 그러한 재료들에 필요로 하는 특정한 물성에 대한 요구를 충족시키고 광범위하게 적용될 수 있는 시험법 등을 소개하고자 하였다.

• 설비공학논문집
• /
• 제7권3호
• /
• pp.382-395
• /
• 1995

A numerical study has been performed on flow characteristics in a domestic refrigerator whose size is $540mm{\times}1,530mm{\times}680mm$, considering existence of a fan and evaporator. The flow field has been simulated with the low Reynolds number $k-\bar{\varepsilon}$ turbulent model and SIMPLE algorithm based on the finite volume method. The region of fan which makes driving force for cold air distribution was modeled as a region in which momentum sources are generated uniformly. The concept of the distributed pressure resistance was applied to describe the momentum loss from evaporator. The result showed that the rate of cold air distribution into freezing room and cold storage room was almost 7 : 3.

• 한국지반환경공학회 논문집
• /
• 제18권1호
• /
• pp.49-58
• /
• 2017

국내 한랭지역(강원권)의 경우 낮은 연평균 기온에 의한 도로터널 라이닝 내구성에 문제가 발생하게 된다. 이에 따라 라이닝에 균열, 망상균열, 박락, 박리, 누수 등의 문제가 발생하며, 해마다 경제적 손실 및 인명피해가 증가하고 있는 실정이다. 하지만 국내에서는 기온에 따른 도로터널 라이닝의 피해에 대한 연구는 미비한 상태이다. 따라서, 본 논문에서는 한랭지(강원권) 터널 70개를 조사함으로써 현재 한랭지역의 피해현황을 분석하였고, 같은 한랭지역 중 비교적 따뜻한 기온을 가지는 강릉 지역과 기온이 낮은 홍천 지역의 터널 라이닝 피해를 비교함으로써 기온이 도로터널 라이닝에 미치는 영향을 분석하였다.

• 한국건설순환자원학회논문집
• /
• 제5권4호
• /
• pp.466-473
• /
• 2017

콘크리트 구조물은 동일한 환경에 노출되었다 하더라도 하중특성과 콜드조인트 유무에 따라서 확산특성이 변화하고 이에 따라 내구수명이 변하게 된다. 본 연구에서는 기존의 선행연구를 분석하여 OPC 및 GGBFS를 사용한 콘크리트의 압축특성, 인장특성, 콜드조인트를 고려한 함수를 도출하였다. 경간 10.0m의 단순보를 가정하여 하중을 2.5kN/m에서 균열모멘트에 이르는 5.5kN/m까지 증가시키면서 내구수명을 평가하였다. 최대 하중에 이를 경우, 건전부 OPC 콘크리트의 경우 인장영역에서는 89.4%로, 압축영역에서는 101%로 내구수명이 변화하였으며, GGBFS 콘크리트의 경우 80.0%와 106%의 변화가 발생하였다. 콜드조인트의 경우 GGBFS를 사용한 콘크리트에서는 압축부에서는 82~80%로, 인장부에서는 69~61% 수준으로 크게 감소하였는데, 건전부의 확산계수가 OPC에 비하여 작지만 콜드조인트부의 확산성 증가가 상대적으로 크기 때문이다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1994년도 가을 학술발표회 논문집
• /
• pp.200-204
• /
• 1994

Low temperature associated damage mechanism is not well known for asphalt concrete. Many studies have related the thermal cracking of pavement in the roadway in cold region with overall shrinkage of the pavement surface under assumption of homogeneous material. This study, however, was intiated based on the assumption that thermal incompatibility of materials (heterogeneous) in asphalt concrete mixture would be the primary cause of the damages. Acoustic emission technique and microscopic obsevation were employed to evaluate damage mechanism of asphalt concrete due to low temperature. The first method showed the sufficient evidence that asphalt concrete could be damaged by lowered temperature only. The second method showed that the damage by temperature resulted in micro-cracks at the interface between asphalt matrix and aggregate particle. It was concluded that these damage mechanisms were the primary cause of major thermal cracking of asphalt pavement in cold region.

• 공업화학
• /
• 제28권4호
• /
• pp.460-466
• /
• 2017

극지방은 혹한의 날씨로 인해 일반 석유제품을 사용할 경우, 석유제품 내 왁스 성분 등이 고체상으로 석출되어 원활한 연료공급 등에 문제발생을 일으킬 수 있다. 따라서 극지방에서 사용하는 석유제품은 혹한의 온도에 적합하게 생산, 판매되고 있지만 해외로부터 공급받고 있어, 수급의 어려움이 존재한다. 본 연구에서는 기존 남극유를 대체할 수 있는 석유제품을 검토하기 위해 기존 연료에 대한 연료적 특성을 분석한 뒤, 저온특성이 우수한 항공유에 윤활성 향상제를 일정농도 첨가하여, 남극유 대체연료로서 연료적 특성을 분석하였다. 분석결과, 윤활성 향상제인 R621A제품의 윤활성이 가장 우수하였으며, 윤활성 향상제 첨가량이 증가할수록 윤활성이 증가하였지만, 1000 mg/L만 첨가하여도 충분한 윤활성 향상효과를 보였다. 따라서 항공유에 윤활성 향상제를 첨가한 대체연료는 극지방의 혹한 기온에서 사용하여도 큰 문제가 없을 것으로 판단된다.