• 한국건설순환자원학회논문집
• /
• 제6권2호
• /
• pp.103-111
• /
• 2011

본 연구에서는 현재 시멘트 콘크리트 혼합재로서 널리 사용되고 있는 고로수쇄 슬래그와 애쉬의 페이스트 유동특성을 파악하였다. 그 방법으로 혼합재 단독을 사용한 페이스트의 유동특성을 파악하여, 아래와 같은 결론을 얻을 수 있었다. 혼합재 단독의 페이스트 유동특성을 시험하기 위하여, 3종류의 분쇄기를 사용하여 3가지 입도로 분쇄된 분말을 제조하였다. 이 분말을 Rosin-Rammler 분포식을 사용하여 얻은 계수 n 값과 De 값을 유동특성과 비교 분석한 결과에서, 일반적으로 같은 입경 크기 일 때 Ash 분말이 Slag 분말보다 소성점도 및 항복응력이 높았으며, 또한 동일 n 값에서 Ash 분말이 Slag 분말 보다 비교적 높은 소성점도와 항복응력을 나타내었으나, 입도분포 폭의 변화에는 Slag 분말이 Ash 분말 보다 민감한 유동특성의 변화 경향을 나타내었다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1993년도 봄 학술발표회 논문집
• /
• pp.176-181
• /
• 1993

Recent increasing traffic volumes have made many bridges on highway be widened. Depending on the construction method of bridge widening, several undesirable problems have been arisen with the additional stresses resulting from de-staging of new bridge and the difference of the amount of creep and shrinkage between new and existing bridge. The main focus of this paper is given to investigate the variation of the adhesive strength of steel bar and construction joints of new and old concrete slab. The result shows that repeated vibration loadings was caused some bad effects on the construction joints between new and existing bridges.

• Advances in concrete construction
• /
• 제13권3호
• /
• pp.243-254
• /
• 2022

Reinforced concrete (RC) deep beams are critical structural elements used in offshore pile caps, rectangular cross-section water tanks, silo structures, transfer beams in high-rise buildings, and bent caps. As a result of the low shear span ratio to effective depth (a/d) in deep beams, arch action occurs, which leads to shear failure. Several studies have been carried out to improve the shear resistance of RC deep beams and avoid brittle fracture behavior in recent years. This study was performed to investigate the behavior of RC deep beams numerically and experimentally with different reinforcement arrangements. Deep beams with four different reinforcement arrangements were produced and tested under monotonic static loading in the study's scope. The horizontal and vertical shear reinforcement members were changed in the test specimens to obtain the effects of different reinforcement arrangements. However, the rebars used for tension and the vertical shear reinforcement ratio were constant. In addition, the behavior of each deep beam was obtained numerically with commercial finite element analysis (FEA) software ABAQUS, and the findings were compared with the experimental results. The results showed that the reinforcements placed diagonally significantly increased the load-carrying and energy absorption capacities of RC deep beams. Moreover, an apparent plastic plateau was seen in the load-displacement curves of these test specimens in question (DE-2 and DE-3). This finding also indicated that diagonally located reinforcements improve displacement ductility. Also, the numerical results showed that the FEM method could be used to accurately predict RC deep beams'behavior with different reinforcement arrangements.

• Steel and Composite Structures
• /
• 제4권5호
• /
• pp.385-402
• /
• 2004

Nearly 400 composite railway bridge decks of a new kind belonging to the trough type with U-shaped cross section have been constructed in Belgium over the last fifteen years. The construction of these bridge decks is rather complex with the preflexion of precambered steel girders, the prestressing of a concrete slab and the addition of a 2nd phase concrete. Until now, they have been designed with a classical computation method using a pseudo-elastic analysis with modular ratios. Globally, they perform according to the expectations but variability has been observed between the measured and the computed camber of these bridge decks just after the transfer of prestressing and also at long-term. A statistical analysis of the variability of the relative difference between the measured camber and the computed camber is made for a sample of 36 bridge decks using no less than 10 variables. The most significant variables to explain this variability at prestressing are the ratio between the maximum tensile stress reached in the steel girders during the preflexion and the yield strength and the type of steel girder. For the same sample, the long-term camber under permanent loading is computed by two methods and compared with measurements taken one or two years after the construction. The camber computed by the step-by-step method shows a better agreement with the measured camber than the camber computed by the classical method. The purpose of the paper is to report on the statistical analysis which was used to determine the most significant parameters to consider in the modeling in order to improve the prediction of the behaviour of these composite railway bridge decks.

• 플랜트 저널
• /
• 제14권4호
• /
• pp.48-54
• /
• 2018

발전설비에서의 질소산화물 배출 규제치가 강화됨에 따라 1990년대에 설치된 HRSG도 탈질설비를 추가로 설치해야 하는 상황이 되었다. 그러나 HRSG 내부에 촉매와 암모니아 분사장치 모두를 설치할 수 있는 공간이 없기 때문에 그 대안으로써 HRSG 내부에는 촉매만 설치하고 암모니아 분사장치는 가스터빈 배기덕트로 변동하여 설치하는 것을 검토하였다. 본 연구에서는 인천복합발전소를 대상으로, 암모니아 분사장치를 HRSG 중압 과열기 후단과 가스터빈 배기덕트에 설치하여 암모니아를 분사였을 때 대기 배출기준 8.5 ppm을 만족하는 암모니아 소비량을 각각 측정하였다. 연구결과 가스터빈 배기덕트 암모니아 분사방식이 HRSG 중압 과열기 후단 분사방식에 비해 소비량이 1.2배 정도 증가한 것으로 나타났다. 따라서 HRSG 수명 30년 운영을 고려한다면 HRSG 내부에 암모니아 분사장치를 설치할 수 없는 경우 가스터빈 배기덕트에 암모니아 분사장치를 설치하는 것이 추천된다.

• Computers and Concrete
• /
• 제7권4호
• /
• pp.347-364
• /
• 2010

Since its invention in the $19^{th}$ century, Reinforced Concrete (RC) has been widely used in the construction of a lot of different structures, as buildings, bridges, nuclear central plants, or even ships. The details of the mechanical response for this kind of structures depends directly upon the material behavior of each component: concrete and steel, as well as their interaction through the bond-slip, which makes a rigorous engineering analysis of RC structures quite complicated. Consequently, the practical calculation of RC structures is done by adopting a lot of simplifications and hypotheses validated in the elastic range. Nevertheless, as soon as any RC structural element is working in the inelastic range, it is possible to obtain the numerical prediction of its realistic behavior only through the use of non linear analysis. The aim of this work is to develop a new kind of Finite Element: the "Enhanced Solid Element (ESE)" which takes into account the complex composition of reinforced concrete, being able to handle each dissipative material behavior and their different deformations, and on the other hand, conserving a simplified shape for engineering applications. Based on the recent XFEM developments, we introduce the concept of nodal enrichment to represent kinematics of steel rebars as well as bonding. This enrichment allows to reproduce the strain incompatibility between concrete and steel that occurs because of the bond degradation and slip. This formulation was tested with a couple of simple examples and compared to the results obtained from other standard formulations.

• Journal of Microbiology and Biotechnology
• /
• 제31권12호
• /
• pp.1732-1740
• /
• 2021

Tobacco etch virus protease (TEVp) is a useful tool for removing fusion tags, but wild-type TEVp is less stable under oxidized redox state. In this work, we introduced and combined C19S, C110S and C130S into TEVp variants containing T17S, L56V, N68D, I77V and S135G to improve protein solubility, and S219V to inhibit self-proteolysis. The solubility and cleavage activity of the constructed variants in Escherichia coli strains including BL21(DE3), BL21(DE3)pLys, Rossetta(DE3) and Origami(DE3) under the same induction conditions were analyzed and compared. The desirable soluble amounts, activity, and oxidative stability were identified to be reluctantly favored in the TEVp. Unlike C19S, C110S and C130S hardly impacted on decreasing protein solubility in the BL21(DE3), but they contributed to improved tolerance to the oxidative redox state in vivo and in vitro. After two fusion proteins were cleaved by purified TEVp protein containing double mutations under the oxidized redox state, the refolded disulfide-rich bovine enterokinase catalytic domain or maize peroxidase with enhanced yields were released from the regenerated amorphous cellulose via affinity absorption of the cellulose-binding module as the affinity tag.

• Animal Bioscience
• /
• 제37권2호
• /
• pp.193-202
• /
• 2024

Objective: Oxidative stress (OS) is a pathological process arising from the excessive production of free radicals in the body. It has the potential to alter animal gene expression and cause damage to the jejunum. However, there have been few reports of changes in the expression of long noncoding RNAs (lncRNAs) in the jejunum in piglets under OS. The purpose of this research was to examine how lncRNAs in piglet jejunum change under OS. Methods: The abdominal cavities of piglets were injected with diquat (DQ) to produce OS. Raw reads were downloaded from the SRA database. RNA-seq was utilized to study the expression of lncRNAs in piglets under OS. Additionally, six randomly selected lncRNAs were verified using quantitative real-time polymerase chain reaction (qRT-PCR) to examine the mechanism of oxidative damage. Results: A total of 79 lncRNAs were differentially expressed (DE) in the treatment group compared to the negative control group. The target genes of DE lncRNAs were enriched in gene ontology (GO) terms and Kyoto encyclopedia of genes and genomes (KEGG) signaling pathways. Chemical carcinogenesis-reactive oxygen species, the Foxo signaling pathway, colorectal cancer, and the AMPK signaling pathway were all linked to OS. Conclusion: Our results demonstrated that DQ-induced OS causes differential expression of lncRNAs, laying the groundwork for future research into the processes involved in the jejunum's response to OS.

• 한국산학기술학회논문지
• /
• 제12권5호
• /
• pp.2416-2424
• /
• 2011

본 연구는 건축에서 모듈화를 중심으로 한 기계적 생산에서 시리얼화를 중심으로 한 디지털 생산 체계로의 변화가 어떠한 방식으로 현대 건축의 외피 디자인 영향을 미치는지를 통해 디지털 기술의 발달이 건축 외피의 매체적 표현 양상의 구축과 적극적으로 공조하고 있음을 파악하려 한다. 이를 바탕으로 헤르죠그와 디모론의 2개의 전시시설의 분석을 통해 외피의 구현이 코드화와 이를 생산하기 위한 부재의 시리얼화라는 개념으로부터 가능하다는 사실을 밝히며 외피가 이미지의 즉각적인 표상을 통해 인간과의 지각적 소통이 가능한 매체적 방식으로 구현되는 과정에서의 디지털 디자인 기술의 역할과 의의를 파악하려 한다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권7호
• /
• pp.3313-3317
• /
• 2012

Prostate cancer is a highly prevalent disease in older men of the western world. MicroRNAs (miRNAs) are small RNA molecules that regulate gene expression via posttranscriptional inhibition of protein synthesis. To identify the diagnostic potential of miRNAs in prostate cancer, we downloaded the miRNA expression profile of prostate cancer from the GEO database and analysed the differentially expressed miRNAs (DE-miRNAs) in prostate cancerous tissue compared to non-cancerous tissue. Then, the targets of these DE-miRNAs were extracted from the database and mapped to the STRING and KEGG databases for network construction and pathway enrichment analysis. We identified a total of 16 miRNAs that showed a significant differential expression in cancer samples. A total of 9 target genes corresponding to 3 DE-miRNAs were obtained. After network and pathway enrichment analysis, we finally demonstrated that miR-20 appears to play an important role in the regulation of prostate cancer onset. MiR-20 as single biomarker or in combination could be useful in the diagnosis of prostate cancer. We anticipate our study could provide the groundwork for further experiments.