환경인자에 노출된 탄소섬유/에폭시 복합재의 장기 층간전단강도 예측

윤성호 ( Sung Ho Yoon ),( Ya Long Shi ) 한국복합재료학회 2017 Composites research Vol.30 No.1

본 연구에서는 환경인자에 노출된 탄소섬유/에폭시 복합재의 층간전단강도를 이용하여 장기 성능을 예측하였다. 필라멘트와인딩 공법으로 제작된 층간전단시편은 분위기 온도가 50℃, 70℃, 100℃인 건조 조건과 분위기 온도가 25℃, 50℃, 70℃인 침수 조건에 각각 3000시간까지 노출시켰다. 연구결과에 따르면 분위기 온도가 50℃ 와 70℃인 건조 상태에서는 층간전단강도가 노출시간에 따라 크게 변하지 않지만 분위기 온도가 100℃인 건조 상태에서는 노출시간이 길어지면 후경화로 인해 다소 증가한다. 그러나 분위기 온도가 25℃인 침수 상태의 경우 층간전단강도는 노출 초기에 크게 변하지 않다가 노출시간이 길어지면 감소하고 감소 정도는 분위기 온도가 높아지면 커진다. 각 분위기 온도에 대한 층간전단강도 선형회귀식은 침수 상태에 3000시간까지 노출된 시편에서 얻은 층간전단강도에서 구할 수 있었다. 이들 선형 회귀식을 이용하면 층간전단강도는 분위기 온도가 25℃와 50℃인 경우 측정값의 5.5% 이내, 분위기 온도가 70℃인 경우 측정값의 2.3% 이내로 예측이 가능하였다. 따라서 제시된 성능 예측 절차는 환경인자에 노출된 탄소섬유/에폭시 복합재의 장기 층간전단강도를 잘 예측할 수 있다. The purpose of this study was to predict the long-term performance using the interlaminar shear strength of carbon fiber/epoxy composites exposed to environmental factors. Interlaminar shear specimens, manufactured by the filament winding method, were exposed to the conditions of drying at 50℃, 70℃, and 100℃ and of immersion at 25℃, 50℃, and 70℃ for up to 3000 hours, respectively. According to the results, the interlaminar shear strength did not vary significantly with the exposure time for the drying at 50℃ and 70℃, but it increased somewhat for the drying at 100℃ due to the post curing as the exposure time increased. The interlaminar shear strength of the specimens exposed to the immersion at 25℃ did not change significantly at the beginning of exposure, but it decreased with the exposure time and the degree of decrease increased as the environmental temperature increased. The linear regression equations for the environmental temperatures were obtained from the interlaminar shear strength of the specimens exposed to the immersion for up to 3000 hours. Using these linear regression equations, the interlaminar shear strength was estimated to be within 5.5% of the measured value at 25℃ and 50℃, and 2.3% of the measured value at 70℃. Therefore, the proposed performance prediction procedures can predict well the long-term interlaminar shear strength of carbon fiber/epoxy composites exposed to environmental factors.

Investigating Various Factors Affecting the Long-Term Compressive Strength of Heat-Cured Fly Ash Geopolymer Concrete and the Use of Orthogonal Experimental Design Method

Hongen Zhang,Lang Li,Prabir Kumar Sarker,Tao Long,Xiaoshuang Shi,Qingyuan Wang,Gaochuang Cai 한국콘크리트학회 2020 International Journal of Concrete Structures and M Vol.14 No.1

This work quantified the hierarchy of the influence of three common mixture design parameters on the compressive strength and the rate of strength increase over the long term of low-calcium fly ash geopolymer concrete (FAGC) through designing 16 mixtures by the orthogonal experimental design (OED) method. The parameters used in the study were liquid to fly ash (L/FA) ratio, sodium hydroxide concentration (SHC) and sodium silicate solution to sodium hydroxide solution (SS/SH) ratio. The L/FA ratio showed little effect on compressive strength when it was varied from 0.40 to 0.52. SHC showed the greatest influence on compressive strength with little impact on the rate of strength increase after the initial heat curing. Even though the SS/SH ratio showed a small effect on the initial compressive strength, it had a considerable influence on the rate of strength increase over the long term. It was found that the compressive strength at 480 days was positively related to the Na₂O/SiO₂ molar ratio when it was varied from 0.49 to 0.80 and the Si/Al molar ratio was increased up to 1.87. Analysis of the failure types of specimens demonstrated that compressive strength of FAGC was associated with the strength of the mortar–aggregate interface zone (MAIZ).

Flowering time quantitative trait Loci analysis of oilseed brassica in multiple environments and genomewide alignment with Arabidopsis.

Long, Y,Shi, J,Qiu, D,Li, R,Zhang, C,Wang, J,Hou, J,Zhao, J,Shi, L,Park, Beom-Seok,Choi, S R,Lim, Y P,Meng, J Genetics Society of America [etc.] 2007 Genetics Vol.177 No.4

<P>Most agronomical traits exhibit quantitative variation, which is controlled by multiple genes and are environmentally dependent. To study the genetic variation of flowering time in Brassica napus, a DH population and its derived reconstructed F(2) population were planted in 11 field environments. The flowering time varied greatly with environments; 60% of the phenotypic variation was attributed to genetic effects. Five to 18 QTL at a statistically significant level (SL-QTL) were detected in each environment and, on average, two new SL-QTL were discovered with each added environment. Another type of QTL, micro-real QTL (MR-QTL), was detected repeatedly from at least 2 of the 11 environments; resulting in a total of 36 SL-QTL and 6 MR-QTL. Sixty-three interacting pairs of loci were found; 50% of them were involved in QTL. Hundreds of floral transition genes in Arabidopsis were aligned with the linkage map of B. napus by in silico mapping; 28% of them aligned with QTL regions and 9% were consistent with interacting loci. One locus, BnFLC10, in N10 and a QTL cluster in N16 were specific to spring- and winter-cropped environments respectively. The number of QTL, interacting loci, and aligned functional genes revealed a complex genetic network controlling flowering time in B. napus.</P>

The Optimum Method for Determining the Corona Onset Voltage Gradient of Bundle Conductors on UHV AC Power Line

Shi-long Huang,Yun-Peng Liu 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.4

The COG (Corona Onset Voltage Gradient) of bundle conductors, as an important parameter in the design of transmission lines, is related to the electromagnetic environment around the transmission lines. Therefore, it is important to accurately determine the COG. At present, there are several methods to determine the COG, the values of COG obtained by diff erent methods are quite diff erent, and the reasonableness of these methods is still not clear. In this paper, combined with the UHV corona cage set in Ping’an County, Xining city (elevation 2200 m), the corona characteristic measurement system and UV imager, the platform for measuring corona discharge characteristics of bundle conductors was built. For the 8 × LGJ-630 bundle conductors commonly used on UHV transmission lines, the change of corona discharge intensity was observed by UV imager. Then, the E (fi eld intensity)– I (resistance current), the E – P (square root of corona loss), E – PH (UV photon number), E – RI (radio interference), E – AN (audible noise) curves were measured. By using the tangent method, the experimental values of COG were obtained. Finally, the COG obtained by the fi ve methods are analyzed and discussed, the COG values obtained by the E – I curve and E – P curve are basically the same, with a deviation of about 1.5%, it has clear physical signifi cance. While the deviation of the COG obtained by the E – PH , E – RI , and E – AN curves are about 10.4%, 29.9%, and 5.7%, respectively. And the optimal method proposed for determining the COG is E – I curve or E – P curve.

Cyclic Loading Tests on Composite Joints with Flush End Plate Connections

SHI Wen-long,LI Guo-qiang,YE Zhi-ming,R. Y. Xiao 한국강구조학회 2007 International Journal of Steel Structures Vol.7 No.2

The tests on composite joint specimens with flush end plate connections subjected to cyclic loads have been conducted inTongji University. One bare steel joint specimen has also been tested for comparison. Various instrumentations have been usedto measure: beam strains, column strains, rebar strains, connection deformations and deflections of specimens. The testobservations are reported in detail in this paper. The main results are as folows: (1) the moment-rotation relationships of thenability; (2) the composite joint specimens show large strength resistance and god ductility, and all the rotations of conectionare greater than 0.03rad as required by the FEMA-97; (3) similar failure modes have been identified from the observation ofthe composite specimens, which are found to be concentrated around the joint zone; and (4) the slipage between the concreteslab and steel beam is very small, which shows that betwen the concrete slab and steel beam the ful composition can be

중국경제 고성장하의 저고용 원인에 관한 연구

마세룡(Shi-Long Ma),배진한(Jin-Han Bai) 충남대학교 경영경제연구소 2013 경영경제연구 Vol.36 No.1

경제성장률과 고용증가율 사이에는 일반적으로 높은 양의 상관관계가 존재한다. 그러나 중국경제는 높은 경제성장과 낮은 고용증가의 공존현상을 보여주었다. 이와 같은 현상을 해명하고자 본 연구는 초월대수비용함수와 바용점유율함수를 이용한 추정모형으로 중국의 고용탄력성을 측정하였는데 중국의 고용탄력성은 중부지역의 3차산업을 제외하고 전반적으로 하락하는 추세를 보여주었다. 이와 같은 현상은 기술진보의 자본편향성, 규모효과, 노동의 자본으로 대체의 용이성 강화, 임금상승효과 등 여러 측면의 요인들이 종합적으로 작용한 결과일 것이다. 중국정부로서는 경제성장과 고용증가라는 두 가지 목표를 달성가기 위해 고용탄력성에 영향을 주는 요인들을 제거해야 할 것이다. 따라서 중국정부는 고용성장 우선으로의 정책 전환, 성장방식의 내수회복으로의 전환, 자본사용적인 산업에서 노동사용적인 산업에로의 투자방향의 전환, 산업구조조정을 통한 산업의 세분화와 노동의 세분화 및 전문화 추진, 정부 차원의 자본사용적 기술진보로부터 노동사용적 기술진보로의 전환을 유도하는 일련의 유인책마련, 새로운 첨단기술을 이용한 신생산업의 육성, 구조조정, 노동시장 개선 등과 같은 일련의 정부차원의 정책들을 제정하고 강력히 추진하여야 할 것이다. Economic growth generally has a positive correlation with employment increase, that is to say, the higher the economic growth rate is, the more the employed labor force will be. What"s the relationship between China"s economic growth and employment? In order to answer those questions, the paper, China"s employment elasticity was measured. In addition, China"s eastern and central and western employment elasticity was measured. Also on the primary industry, secondary industry and tertiary industry employment elasticity was measured. with using The transcendental logarithmic cost function and Labor cost share function. The results found that China"s employment elasticity is low, and gradually decline. due to are Government and enterprise Selected that capital-intensive industries instead of labor-intensive industries, The paper holds that there are varies reasons for the deviation of the relationship from tradition theories, such as the mode of economic growth, technological progress, unreasonable industrial structure, system reforming and the imperfect labor market and so on. Facing the protracted situation of excessive supply of the labor force, great importance should be attached to the employment. The paper suggests that the importance of strategic target of “employment first” should be fully recognized first of all, and corresponding measures should be taken in the process of choosing technology routes, adjusting the industrial structure, developing the labor market etc Only in this way, can we solve the serious problem of employment fundamentally.

부동한 온도처리가 호랑나비의 생장발육에 주는 영향

여용석(Long Shi Lu),맹염령(Yan Ling Meng),김대용(Da Yong Jin) 강원대학교 농업과학연구소 2002 심포지움-생물자원의 보고 장백산 Vol.2002 No.-

Human HS1BP3 induces cell apoptosis and activates AP-1

( Tai Ping Shi ),( Jie Shi Xie ),( Ying Xiong ),( Wei Wei Deng ),( Jin Hai Guo ),( Feng Wang ),( Da Long Ma ) 생화학분자생물학회(구 한국생화학분자생물학회) 2011 BMB Reports Vol.44 No.6

In the present study, we characterized the function of HS1-binding protein 3 (HS1BP3), which is mutated in essential tremor and may be involved in lymphocyte activation. We found that HS1BP3 localized to the mitochondria and endoplasmic reticulum partially. Overexpression of HS1BP3 induced apoptosis in HEK293T and HeLa cell lines. When these cell lines were transfected with HS1BP3, they exhibited nuclear DNA condensation, externalization of phosphatidylserine (PS), and cleavage of poly ADP ribose polymerase (PARP). Furthermore, suppression of HS1BP3 or HS1 expression attenuates HS1BP3 induced apoptosis. In addition, HS1BP3 enhanced activator protein 1 (AP-1)-mediated transcription in a dose-dependent manner. Therefore, we conclude that HS1BP3 regulates apoptosis via HS1 and stimulates AP-1-mediated transcription. [BMB reports 2011; 44(6): 381-386]

오색학설(五⾊學說)에 의한 중국 전통 경극(京劇)에서의 검보(臉譜) 색채 조사

류세룡(Liu, Shi Long),김주연(Kim, Ju Yeon) 한국디지털디자인협의회 2014 (사)한국디지털디자인협의회 conference Vol.2014 No.5

Mechanical Property Test and Analytical Method for Reactive Powder Concrete Columns under Eccentric Compression

Cheng-hua Shi,Min Long,Cheng-yong Cao,Guangcheng Long,Ming-feng Lei 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.4

Reactive Powder Concrete (RPC) has ultra-high strength, toughness and durability. Review studies were focused on the mechanical properties of RPC material and RPC beam. In this paper, the bearing features of RPC columns under eccentric compression with different section dimensions, reinforcement ratios, and conditions of with and without steel fibres were determined through large eccentric compression test of 22 RPC columns. The distribution patterns of stresses over the section of the RPC columns under large eccentric compression were determined under cracking loads. A simple analytical method for the cracking loads was also established. Test results revealed that the thickness ratio of elastic tensile region and the whole tensile region can be 0.4 (with steel fibres) or 0.5 (without steel fibres) when calculating the cracking loads. The tensile stress on the RPC columns showed an isosceles triangle distribution in the tensile region. A simple analytical method for calculating the ultimate loads of RPC columns under large eccentric compression was set up. Test results revealed that the equivalence coefficient of the RPC column in tensile regions can be 0.6 (with steel fibres) or 0.4 (without steel fibres). The method deduced in this paper can be used to design the RPC column under large eccentric compression.